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2018-04-03T00:23:08.597Z
|
1970-08-01T00:00:00.000Z
|
11938365
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s2ag/train
|
Left atrial tumor presenting with hemoptysis and pulmonary infiltrates.
A patient with persistent hemoptysis and progressive pulmonary infiltrates was found at postmortem to have a leiomyosarcoma of the left atrium that was occluding the right pulmonary veins. Venous thromboses, inflammatory exudation, and septal fibrosis were found in areas drained by the occluded veins and were responsible for the clinical and radiographic picture. This case adds pathologic confirmation to the previously suspected association between left atrial tumors and pulmonary venous infarctions.
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v2
|
2018-04-03T06:23:39.950Z
|
1970-08-24T00:00:00.000Z
|
46624951
|
s2ag/train
|
Papilledema and hypervitaminosis A.
To the Editor.— The letter by Fedontin ( 212 :628, 1970) describing the case of pseudotumor cerebri produced in an 18-year-old girl by hypervitaminosis A, includes the statement, "In none of the casesadults or children—has papilledema been the only finding." This patient was observed at Ohio State University Hospital. Oliver and Havener 1 described in 1958 the case of a 14-year-old girl with bilateral papilledema, as well as loss of hair, skin changes, migratory arthritic pains, hepatomegaly and splenomegaly, hypomenorrhea, and generalized malaise. Serum vitamin A levels confirmed the diagnosis of hypervitaminosis A. Morrice et al 2 in 1960 described three cases in girls 14, 15, and 16 years with diplopia, papilledema, and other symptoms suggesting brain tumor. In addition to various individual complaints, each had hypomenorrhea, alopecia, and rhagades or other marked forms of dermatosis. Ironically, these four additional cases of papilledema due to hypervitaminosis A were all observed at
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v2
|
2014-10-01T00:00:00.000Z
|
1970-09-01T00:00:00.000Z
|
14142901
|
s2orc/train
|
The effect of multiple tumours on mammary tumour growth rates in the C3H mouse.
Spontaneous and transplanted tumour growth rates studied in the C3H mouse have shown that when only one spontaneous tumour was present in one strain then the distribution of growth rates closely resembled that for first generation isotransplants of another strain. It was also shown that the number of spontaneous tumours (in the range one to four tumours) present on the mouse affected the tumour growth rate, i.e. the more tumours per mouse, the slower the growth rate of the earliest tumour. This factor might partly account for the discrepancy between human tumour growth rates (normally determined when many tumours are present in the patients) and the faster tumour growth rates observed in experimental animals, in which normally only single tumours are present.
the slower the growth rate of the earliest tumour. This factor might partly account for the discrepancy between human tumour growth rates (normally determined when many tumours are present in the patients) and the faster tumour growth rates observed in experimental animals, in which normally only single tumours are present. THE measurement of tumour growth rate under clinical conditions (Collins, Loeffler and Tivey, 1956;Schwartz, 1961;Spratt, Ter-Pogassian and Long, 1963;Spratt and Spratt, 1964;Bruer, 1965), and in experimental animal systems (Steel and Lamerton, 1966;Dethlefsen, Prewitt and Mendelsohn, 1968) has been the subject of extensive study. Mathematical expressions to fit such growth curves are generally exponential (Hawkes, Hill, Lindop, Ellis and Rotblat, 1968;Collins et al., 1956) or closely resemble exponentials such as the Gompertzian function (Laird, 1965). Spontaneous human tumours display a large variation of growth rates. Doubling times ranging from 34 to 310 days (Collins, 1962) for pulmonary metastases and 3 to 211 days for recurrent mammary cancers (Philippe and Le Gal, 1968) have been reported. In contrast, experimental tumours in animal systems have doubling times of the order of 1 to 30 days (Hawkes et al., 1968). Recent attempts to explain this difference have involved studies of cellular kinetics (Steel, Adams and Barrett, 1966) and the study of animal tumours with growth rates approximating to those found in man (Steel, 1969, private communication).
In the present study the tumour growth rates have been compared in animals carrying one or several spontaneous mammary tumours and also with growth rates of first generation isotransplants. From this it could be determined whether or not the number of tumours present on an animal affects their growth rate. Such a finding could contribute to the observed discrepancy between tumour growth rates in the human clinical and animal experimental systems. *Present address: Huntingdon Research Centre, Huntingdon.
Mice
Spontaneous tumours. Adult castrated male mice (C3H -x 020)F1, treated with oestrogen in their drinking water were supplied by " The European Centre for the Provision and Study of Tumour Bearing Mice" in Amsterdam. These mice develop spontaneous tumours at about 6 months old, being received when their first tumour becomes palpable. Such tumours developed anywhere in the mammary region. Many mice developed more than one tumour and in some cases as many as five or six before it became necessary to kill the mouse. The first tumour palpable was called the first tumour and any tumours developing subsequently were numbered chronologically as they appeared. It was not known whether these subsequent tumours were secondaries or multiple primary tumours. Frequently the time between palpation of the first and second was so short-only a few days-that metastatic origin was unlikely. However, the term " second " tumour is used in this communication to mean the second tumour to be observed, to be distinguished from the clinical use of the word "secondaries ".
Thirty-nine mice were used, giving a total of eighty-three spontaneous tumours. Transplanted tumours.-Specific pathogen free, 6-12 month old C3H female mice were used for first generation isotransplants of a spontaneous mammary tumour arising in a specific pathogen free female of the same strain. --The spontaneous tumour incidence in the recipient mice was less than 1 % at 18 months of age. A total of 50 mice were used each with one tumour.
Tumour measurement
The mice were weighed twice a week and the three diameters of their tumours measured using vernier calipers. If a tumour ulcerated or grew to such a size as to cause discomfort, the mouse was killed. The product of the three diameters (in mm3) was taken as the relative volume of the tumour. Aftermeasurement, some tumours were dissected out and their actual volume determined. Fig. 1 shows a plot of the relative volume against actual volume for these tumours. Within the range 100-3000 mm3 relative volume a linear relationship exists of Relative Volume 1-125 X Actual Volume of the Tumour.
Determination of growth rate A typical graph of relative tumour volume against time for a particular tumour is shown in Fig. 2a. Fig. 2b shows these data plotted as log1o (relative volume) against time. Within the range 100 mm3 to 3000 mm3 relative volume tumours in general grew exponentially. The best straight line to fit these points within this range was drawn by eye and from the slope of the line the doubling time (D.T.) was determined for that particular tumour.
RESULTS
The frequency distributions of doubling times of the eighty-three spontaneous tumours and the fifty transplanted tumours are shown in Fig. 3a and Fig. 3b respectively. The range of D.T.'s of 175 to 17-5 days and mean of 5-9 days for spontaneous tumours is noticeably larger than the range of 2-05 to 8 days and mean of 4-19 for transplanted tumours. Table I tumours on the mouse refers to the number which had grown to 3000 mm3 relative volume such that the D.T. was determined. Mice were grouped according to the number of tumours present at death on the animal, and Table I shows how the mean D.T. of the number one tumour determined from each group varies with the number of tumours on the mouse. This gives a linear correlation coefficient of +0-98 and suggests a significant (P < 0.025) relationship between rates of growth of a particular tumour and the number of tumours present on the animal. Fig. 4 is a histogram ofthe distribution oftumour doubling times ofmice with only one spontaneous tumour. Comparison of this with that for transplanted tumours (Fig. 3b) shows an insignificantly different (P < 0.010) mean value of 4-3 days. Significance of difference of slope of regression line from zero (P < 0* 025).
DISCUSSION
The dependance of the growth rate of spontaneous tumours in the C3H mouse on the number of tumours present is in contradiction to findings by other authors (Hawkes, 1966;Denenkamp and Fowler, 1966, private communication). Both these authors drew their conclusions from observations of growth curves of individual mice rather than considering the tumours as a group.
The slower growth rate observed when a number of tumours are present on the mouse may be due to systemic exhaustion, namely, the cachexia of human cancer patients, or an accelerated immune mechanism. This latter could for example be an alteration in the " feed-back " mechanism regulating a substance inhibiting cancerous cell growth as postulated in the Diffusion Model of radiation carcinogenesis (Wright and Peto, 1969). However, whilst cell loss factors (Steel et al., 1966;Tannock, 1969) and different vascular supplies (Hill, 1967) producing different levels of oxygenation within the tumour may be responsible for decreasing growth rates above 3000 mm3 relative volume, it is difficult to postulate that such causes explain the difference between the multi-spontaneous and transplanted tumour situations in the range 100-3000 mm3 relative volume. Especially since their growth rates are so similar when considering the mice with only one spontaneous tumour.
In experimental situations caution must therefore be applied in presenting a mean value of spontaneous tumour growth rate (Hawkes et al., 1968;Du Sault and Kasenter, 1966). Growth rates determined from experimental tumour systems with single tumours are not comparable with the growth rate of human tumours that have been based on lung metastases (Spratt and Spratt, 1964;Collins, 1962) with therefore multiple tumours present on the patient. The same is also true of recent studies on spontaneous tumour volume doubling times reported for the dog and cat (Owen and . In most cases measurements were made on multiple lung metastases and volume doubling times were in consequence long, in the range of 7-150 days. As has been indicated the discrepancy between tumour growth rates in humans (D.T.'s ranging from 34 to 310 days) and experimental animal systems (D.T.'s in general of the order of 4 to 10 days) may therefore be partly accounted for by the multiple tumours present on the patients studied in contrast to single tumour bearing experimental animals. Such an explanation need not evoke models of cell production and loss rate, or significant difference in cellcycle times, but only multiple tumour interaction, which has yet to be explained. 546 4^ I would like to thank Professor P. J. Lindop for her help throughout this project, and William Hall for the diligent measurements of all these tumours. The work was carried out during the tenure of an M.R.C. grant and supported by grants from the British Empire Cancer Campaign for Research and the United States Public Health Service (Grant No. RH 00272).
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v2
|
2017-04-13T07:41:51.122Z
|
1970-09-01T00:00:00.000Z
|
12008371
|
s2ag/train
|
Isolation and propagation of a virus from a spontaneous mammary carcinoma of a rhesus monkey.
Summary Virus particles morphologically similar to the known oncogenic RNA-type viruses have been isolated and cultured from a spontaneous mammary carcinoma of a rhesus monkey. The virus was initially isolated by cocultivation of tumor tissues with monkey embryonic cell cultures but was later found to be transmissible as a cell-free filtrate. The virus is approximately 110 mµ in diameter and has a buoyant density between 1.14 and 1.16. Preliminary host-range studies thus far have shown the virus to replicate in rhesus monkey mixed embryo, embryonic lung, chimpanzee lung, and human mixed embryo cell cultures, and in an established human leukocyte culture, NC-37. Virus did not replicate in hamster kidney, mouse bone marrow, rhesus or African green monkey kidney cells, or baboon or chimpanzee leukocyte cultures.
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v2
|
2017-07-09T07:48:24.782Z
|
1970-09-01T00:00:00.000Z
|
24489294
|
s2ag/train
|
DNA polymerase activity associated with RNA tumor viruses.
C-type RNA viruses, originating in mouse, cat, hamster, and viper, catalyze the synthesis of DNA from its constituent deoxyribonucleoside triphosphates. Both the rate and extent of the reaction were significantly enhanced by brief treatment of the intact virus with ether. A proportion of the newly synthesized DNA was associated with virions when intact virus was used as template; this was not the case with ether-treated virus. In both cases, DNA extracted from the reaction mixture sedimented slowly, at about 2-4 S.
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v2
|
2017-11-08T01:35:44.159Z
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1970-09-01T00:00:00.000Z
|
8760376
|
s2ag/train
|
Transmission of Toxoplasmosis by Leukocyte (WBC) Transfusion
Disseminated toxoplamosis infections without an obvious source have been documented frequently in cancer patients. Two children with acute leukemia given WBC transfusions for granulocytopenia from a donor with chronic myelogenous leukemia (CML) developed toxoplasma gondii infection. The CML donor, with no history of toxoplasma infection had received no anti-leukemic therapy prior to leukapheresis and remained clinically well. The first child was given 0.35 × 1011 CML leukocytes. Three weeks later she developed skin rash, pneumonia, congestive heart failure, hepatitis, and seizures, accompanied by a rising toxoplasma dye titer to 1:8,000 (IgM = 1:160). She expired 3 months later with disseminated toxoplasmosis. The second child received 2.5×1011 leukocytes over a 7-day period four weeks prior to splenectomy for an E. coli splenic abscess. Concomitantly, her dye titer rose to 1:128 (IgM = 1:40). Toxoplasma gondii was isolated from the spleen and a single toxoplasma cyst was found on histologic examination. She died 1 month following surgery with toxoplasma cysts found in the lung and heart at necropsy. Retrospective examination of stored serum samples from the CML donor revealed that at the time of WBC donation she had a toxoplasma dye titer of 1:8,000 (IgM = 1:10, CF = 1:16). Leukocytes from the same donor were given to other leukemic patients. Both died within one week of transfusion without pathologic evidence of toxoplasma infection. Toxoplasma infection in two patients receiving leukocyte transfusions from a CML donor with serologic evidence of toxoplasmosis suggests the role of WBCs in the transmission of this dissease.
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v2
|
2017-11-08T17:41:48.554Z
|
1970-09-01T00:00:00.000Z
|
298536
|
s2orc/train
|
Chromosomal DNA Replication Pattern in Human Tumour Cells in vitro
The present paper deals with the chromosomal DNA replication pattern in human solid tumour cells in vitro. This was studied at the terminal stages of the S-period. All the cell lines of female origin showed a late replicating chromosome in group XX6-12. In cell lines of male origin one of the chromosomes of group 21-22Y was later replicating than the rest of the members of the group. The DNA replication pattern of the autosomes and the sex chromosomes was similar to that of the cultured human leucocytes. The results of the present study show that the DNA replication pattern of the chromosome in neoplastic cells is basically unchanged despite the changes in the chromosome number and morphology. Therefore the abnormal behaviour of the neoplastic cells cannot be related to the changes in the pattern of the chromosomal DNA replication. ImagesFig. 5Fig. 1Fig. 6Fig. 2Fig. 3Fig. 4
AN important event in the life of a cell is mitosis, during which chromosomes are visible and cell division occurs. It has also been established that the long interval between two successive mitoses called " interphase ", includes a series of metabolic events which are important for the process of cell division. One of the metabolic events occurring during interphase is the synthesis of DNA.
The DNA synthesis pattern within an individual chromosome and among chromosomes within a cell differs a great deal. This differential pattern of the DNA replication in the chromosome is considered to be the expression of different genetic activity. In 1964, Taylor suggested, from various types of investigation on different organisms, that the morphological changes in the chromosomes, correlated with developmental stages, are indications of gene action rather than special types of DNA. The application of these aspects and techniques to the study of tumour chromosomes may be of direct relevance to the role of chromosomal DNA synthesis in cancer. Bearing this fact in mind, the present study was undertaken to examine the chromosomal DNA replication pattern in human tumour cells in vitro labelled with tritiated thymidine (H3TDR).
MATERIALS AND METHODS
The five cell lines used are shown in Table I which also shows their sex and the passage number at the time of investigation. At the same time, the duration of the cell cycle was also studied (for details see Kucheria, 1970). of calf serum and grown as a monolayer. Cells from all the five cell lines were continuously labelled with H3TDR, 1 ,tCi/ml. (sp. activity 3 Ci/mM). Cell samples were fixed for chromosome preparations at an interval of two hours. The chromosome preparations were made by using the modification of the technique described by Moorhead et al. (1960) and were stained overnight with 200 lectoacetic orcein. For autoradiography, preparations were covered with Kodak A.R. 10 stripping film; exposed for 2 weeks and finally developed in Kodak developer D 19b (Kucheria, 1970).
The chromosomal DNA replication pattern of the cells, which were labelled at the interphase by the addition of H3TDR, was studied at the first mitosis after labelling. The regions of the chromosomes which replicate in the presence of H3TDR were detected as labelled regions in autoradiographs. The first labelled cell to pass through division was the one at the end of the S-period during exposure to H3TDR and those which pass through mitosis later were labelled in the early S-period. This makes it possible to analyse the replicatory behaviour of each chromosome. In practice the replication of chromosomes at the end of the S-period can be studied best by the continuous labelling method.
RESULTS
The cell line Rh-I showed 56-57, cell line Rh-2 showed 73-75 and cell lines Ne-i, Ne-2 and As-I showed 46 as the modal chromosome numbers. In cell line Rh-I and Rh-2, great karyotypic diversity was observed and neither of the two karyotypes showed similar distribution of chromosomes. Marker chromosomes like abnormal long acrocentrics in the cell line Rh-I and a tiny metacentric in the cell line Rh-2 and abnormal dicentrics in both the cell lines were frequently observed. Cells from cell lines Ne-i, Ne-2 and As-I showed apparently normal karyotypes. Details about the case histories and chromosome pattern of the cell lines are published elsewhere (Kucheria, 1970).
No labelled mitoses were observed after 2 or 4 hours continuous exposure. In cell lines of female origin (Rh-i, Ne-I and As-i) cells fixed after 6, 8 and 10 hours of continuous labelling showed a very heavily labelled median size chromosome of the group XX6-12 (presumably the " hot X ", Fig. 2). While the rest of the chromosomes of group XX6-12 were lightly labelled or unlabelled. In cell line Rh-I some of the cells showed two heavily labelled chromosomes (Fig. 3). In cell lines of male origin (Rh-2 and Ne-2), cells fixed at 6 and 8 hours after continuous labelling showed one of the chromosomes of group 21-22Y, more heavily labelled 485 KIRAN KUCHERIA (presumably the Y chromosome) than the rest of the members of the group (Fig. 4,5).
In all the five cell lines one of the chromosome pair (presumably No. 15) of group [13][14][15]pair No. 17 and chromosomes of the groups 19-20 and 21-22 showed early termination of their DNA synthesis. One of the chromosome pairs of group 19-20 and 21-22 completed their synthesis later (Fig. 2, 5). Chromosome pair No. 1 did not show a consistent labelling pattern, but in most of the cells, some of the arm segments were late replicating than the centromeric region. The centromeric region of the chromosome pair No. 3 and the short arms of chromosome pairs of group 4-5 showed late replication. Two of the chromosomes of group 13-15 (presumably No. 13) showed late labelling of the long arms and the other two (presumably No. 14) showed late labelling of the centromeric region. The chromosomes No. 16 and 18 were seen synthesising very late in the S-period (Fig. 2, 5).
Marker chromosomes present in the cell lines Rh-I and Rh-2 showed labelling pattern similar to the respective autosomes (Fig. 3).
DISCUSSION
The chromosomal DNA replication patterns reported in the present paper were mainly studied at the end of the S-period. Due to the technical problems, it is difficult to study at the beginning of the S-period. The main limitation is the variability in the rate at which individual cells in a single population progress through the mitotic cycle. Cells labelled at a given interval in the S-period pass through mitotis during an interval of time; this interval will be greater for cells labelled earlier in the S-period.
Replication appears to be organised in terms of the function of chromosome regions during interphase. Euchromatin is genetically active, starting replication first and the inactive heterochromatic region replicates last; there is however an extensive overlap in the S-period when both types replicate simultaneously. It is a generally accepted view that the heteropyknotic X-chromosome represents the 1 late labelling X-chromosome observed in autoradiographic studies and the Barr body in resting nuclei. In cell line Rh-i, one to two late labelling chromosomes in group XX6-12 were observed. In cells with 108 chromosomes the presence of the two late labelling chromosomes may be due to the tetraploid complement of the X-chromosome and extra chromosomes may be due to additional autosomes. In cells with 56 to 58 chromosomes, one late labelling chromosome might represent the diploid set of the X-chromosomes. However, some cells (from Rh-i) with 57 and 107 chromosomes had two and some with 55, 107 and 110 chromosomes had only one heavily labelled chromosome present among the members of XX6-12 group.
It is to be seen whether the heavily labelled chromosome observed under the conditions of the present study of tumour cells in vitro is the same as the heavily labelled chromosome of the normal cell. Identification of the X-chromosome on morphological ground only, especially in tumour cells, is very difficult. It has been suggested (Grumbach et al., 1963;Morishina et at., 1962) that in flattened preparations of metaphase cells, the late labelling X-chromosome is positioned at the pheriphery more frequently than would be expected by chance distribution of the chromosomes. A similar peripheral position of the late labelling chromosome was observed in the cells from cell lines Rh-i, As-I and Ne-2. The other support for the identity of one of the X-chromosome is on the pattern of its DNA labelling and it is thought to be the last in group XX6-12 to terminate its DNA synthesis. A late labelling X-chromosome is not found in the normal male (XY) cells where as it is present in normal female (XX) cells.
The morphology, size, position and the DNA replication patterns of the late labelling chromosome observed in the cell from cell lines Rh-i, As-i and Ne-2 are similar to that of the late replicating X-chromosome observed in cultured blood cells of normal human females. Their variation in number, in different cells (Rh-i) could be attributed either to the conditions effecting the long term tissue culture or to the process which was involved in their origin.
The present studies of the five solid tumours in vitro showed that the chromosome DNA replication pattern in cells containing either more or less chromosomes than the modal cells was similar to that of the modal cells. In fact the DNA replication pattern of the chromosomes in the modal cells (tumour cells) is similar to that of the cultured normal human leucocytes (German, 1966), especially in respect to the early termination of the DNA synthesis of the chromosomes number 17 and 19-20. Late DNA replication of one of the X-chromosomes in the female cells has also been reported in other neoplastic cells by some authors. Painter (1961) observed them in HeLa S3 cells, Gavosto et al. (1963) in leukaemic aneuploid leucocytes and Yamada and Sandberg (1966) in cancer effusions cultured for short periods. The last authors found similarities to the normal replication pattern of some autosomes.
The results of the present studies show clearly that the DNA replication pattern of the chromosomes in neoplastic cells is basically unchanged despite changes in chromosome number and morphology (ref. to the cell lines Rh-I and Rh-2 with chromosome modes at 56-57 and 73-75 respectively and presence of marker chromosomes). This indicates that the abnormal behaviour of the neoplastic cells cannot be related to the changes in the pattern of the chromosomal DNA replication. The present results also show that the age of the patient, the passage 487 488 KIRAN KUCHERIA number of the cells in tissue culture, and the different origin of neoplastic cells do not have any significant relationship to the chromosomal IDNA replication pattern.
The author wishes to thank Dr. A. E. Claireaux for his most helpful suggestions. The work was supported by the British Empire Cancer Campaign for Research.
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v2
|
2018-04-03T03:18:51.125Z
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1970-09-01T00:00:00.000Z
|
1813637
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s2ag/train
|
Treatment of squamous cell carcinoma of the head and neck with combined methotrexate and irradiation
Nine years' experience with 200 patients is analyzed retrospectively. In 76% of cases, pre‐irradiation methotrexate produced shrinkage in tumor volume ranging in amount from 25% to 90%. However, there was only a minor impact on the cure rate, because, as demonstrated by serial biopsies, the residual tumor retained its reproductive integrity. Study of tumor shrinkage curves tends to corroborate the clinical impression that methotrexate does not enhance radiation effect but acts as an independent agent. Combined therapy has cured some advanced cancers which might not have been cured with irradiation alone.
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v2
|
2018-04-03T06:15:38.435Z
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1970-09-01T00:00:00.000Z
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46151885
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s2ag/train
|
Group-specific antigen expression during embryogenesis of the genome of the C-type RNA tumor virus: implications for ontogenesis and oncogenesis.
Tests for the group-specific antigen of the C-type RNA tumor virus showed that mouse embryos of all strains tested, at some stage of development in utero, revealed detectable titers of group-specific antigen in one or more of their tissues; younger, rather than older, embryos were likely to be positive, particularly in those strains which normally reveal little or no expression of the RNA genome postnatally. The antigens were found in embryos of low-leukemia strains, free of infectious virus. These new findings support a previously stated hypothesis that the genome of RNA tumor viruses, mostly switched off for infectious virus expression, is vertically transmitted as part of the natural genetic apparatus of normal mouse cells. Since group-specific antigens have also been described in chick embryos and immunological tolerance to homologous group-specific antigens has been demonstrated in hamsters and cats as well as in mice and chickens, the hypothesis has been extended to include vertebrate cells in general. Finally, the high incidence and titers of the group-specific antigen suggest that the genes for RNA tumor virus, which later in life act as determinants of cancer, may be important also as gene determinants in the developing embryo.
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v2
|
2019-08-16T04:01:03.315Z
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1970-09-01T00:00:00.000Z
|
199615395
|
s2ag/train
|
Book Review: Tumours of the Thyroid Gland
shelves, its value as a work ofreference in medical and dental libraries is related to the simple fact that this is the only authoritative book to deal with the subject, and it is unlikely that anything quite like it has appeared before. There are twelve chapters which include considerations of anatomy, breathing, tongue movements with regard to the staccato and legato, and the tiring of facial musculature. The care of the dentition, and advice about early prevention or correction of irregularities of tooth position in a child aspiring to be a wind instrument player is particularly helpful to the uninitiated teacher or parent. The diagrams are clear, but it is a pity that a dentally normal subject was not chosen as a model for the lateral radiographs illustrating certain technical postures of the jaws when playing a comet. The references are full and clearly made, together with a glossary of specialist words to assist the nonmedical reader, and the book is exceptionally well indexed. 'Dental Problems in Wind Instrument Playing' comprises a group of twelve papers written by Mr Porter for the British Dental Journal in 1967-68. These were for the more specialized readership of the dental profession, and although there is some overlap with 'The Embouchure', the booklet is full of extremely useful details, and should be a valuable reference for doctors and dentists who may be consulted by patients seeking advice on oral problems concerned with the playing of wind instruments. Both are much recommended for specialized readership.
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v2
|
2014-10-01T00:00:00.000Z
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1970-10-01T00:00:00.000Z
|
444162
|
s2orc/train
|
Production of both prolactin and growth hormone by clonal strains of rat pituitary tumor cells. Differential effects of hydrocortisone and tissue extracts.
Several established clonal strains of rat pituitary cells which produce growth hormone in culture have been shown to secrete a second protein hormone, prolactin. Prolactin was measured immunologically in culture medium and within cells by complement fixation. Rates of prolactin production varied from 6.6 to 12 µg/mg cell protein per 24 hr in four different cell strains. In these cultures ratios of production of prolactin to growth hormone varied from 1.0 to 4.1. A fifth clonal strain produced growth hormone but no detectable prolactin. Intracellular prolactin was equivalent to the amount secreted into medium in a period of about 1–2 hr. Both cycloheximide and puromycin suppressed prolactin production by at least 94%. Hydrocortisone (3 x 10-6 M), which stimulated the production of growth hormone 4- to 8-fold in most of the cell strains, reduced the rate of prolactin production to less than 25% of that in control cultures. Conversely, addition of simple acid extracts of several tissues, including hypothalamus, to the medium of all strains increased the rate of production of prolactin six to nine times and decreased growth hormone production by about 50%. We conclude that multifunctional rat pituitary cells in culture show unusual promise for further studies of the control of expression of organ-specific activities in mammalian cells.
INTRODUCTION
A number of clonal strains of rat pituitary tumor cells have been established in culture (1,2) . Each of these strains of epithelial cells carries out organ-specific function in vitro ; namely, they synthesize growth hormone and secrete the protein into the culture medium. Three of these strains have been serially propagated for over 4 THE JOURNAL OF CELL BIOLOGY • VOLUME 47, 1970 • pages 6 1 -70 yr without exhibiting any loss of ability to produce growth hormone . In fact, the rate of growth hormone production for the most extensively studied strain, GH3, has actually increased by a factor of three to five times since the line was established (3) .
Recent experiments have suggested that these cell strains may prove to be useful model systems in which to study control mechanisms in the biosynthesis and secretion of proteins, such as hormones, made specifically for export from the cell of origin . For example, Bancroft, Levine, and Tashjian (3) and Kohler et al . (4) have examined the characteristics of the stimulation by hydrocortisone of growth hormone production in the GH 3 and GH, strains, respectively. When the cultured pituitary cells are injected into female rats of the Wistar/Furth strain, they almost invariably give rise to tumors (5) . Concomitant with the appearance of the tumor, both intact and hypophysectomized rats begin to grow rapidly (5) . All organs are greatly enlarged, as is the length of the long bones . The tumorbearing animals may have body weights which are two to four times greater than those of control rats . In the course of examining the organs of tumor-bearing animals it was noted that there was extensive development of the mammary glands . This was first attributed to excessive production of growth hormone by the tumor . However, because the tumor (MtT/W5) from which the cultured cells were derived was reported to have marked mammary gland-stimulating properties (6,7), the possibility existed that the culturederived tumors were also producing, in addition to growth hormone, a substance which stimulated the mammary . gland specifically, namely prolactin . We therefore undertook to determine whether these pituitary cells in culture produced prolactin, a protein hormone which is synthesized by the pituitary gland, and in the rat is chemically distinct from growth hormone (8)(9)(10) .
In this report we describe the results of experiments which show that most of the existing clonal strains of growth hormone-producing cells also synthesize and secrete prolactin at rates comparable to those of growth hormone . In addition, we have found that while hydrocortisone stimulates the production of growth hormone in all but one of these cell strains, this steroid hormone suppresses the production of prolactin . Conversely, the addition of simple extracts of several different tissues to the culture medium has been found to stimulate the production of prolactin and suppress the production of growth hormone . We believe that the ability to stimulate the production of one exportable protein while suppressing the production of another makes these cell strains promising model systems for 1 Abbreviations used : HC, hydrocortisone sodium studying the mechanisms which underlie the 62 THE JOURNAL OF CELL BIOLOGY • VOLUME 47, 1970 control of expression of differentiated function in mammalian cells .
Materials
Hydrocortisone sodium succinate was obtained from the Upjohn Co ., Kalamazoo, Mich . Stock solutions of HCl were made in 0.15 M NaCl at a concentration of 9 X 10 -5 s . They were stored at 4°C for no more than 1 wk. Cycloheximide and puromycin dihydrochloride were purchased from Nutritional Biochemicals Corp., Cleveland, Ohio . Highly purified rat prolactin (Fraction D) was kindly donated by Dr . Albert F . Parlow (UCLA) . This preparation of prolactin has specific biological activity of 15-20 international units/mg as determined by the intradermal pigeon crop sac assay method (10) . It was assayed immunologically for contamination with growth hormone by complement fixation (see below) and was found to contain about 0 .27 growth hormone . This small degree of contamination does not introduce a significant error in estimates for prolactin when this material is used as standard in our immunoassay method . Likewise, since rat growth hormone is an extremely poor immunogen in rabbits (11), this preparation of prolactin, when used for immunization, did not give rise to detectable antibodies to growth hormone (see below) .
Methods of Culture
The origin and methods of culture of three of the rat pituitary tumor cell strains (GH 1, GH ,2C 1, and GH s) have been described in detail previously (1,2,5) . The GH, cells which were used in the present experiments had been frozen for 34 months . They were thawed and placed in culture 5 months before these studies (2) . Two new strains, not previously described, have also been used in this report . These strains are designated GH3C1 and GH 3C5 . They are subclones of GH s which were established in June 1969 by plating single GH3 cells in micro-Petri dishes (6 X 10 mm, Linbro Chemical Co ., New Haven, Conn .) containing 0 .1 ml of medium (F. C . Bancroft and A. H . Tashjian, Jr . In preparation) .
Experiments were performed in plastic tissue-culture dishes (50 X 15 mm, Falcon Plastics, Division of B-D Laboratories, Inc., Los Angeles, Calif .) containing 3 ml of Ham's F 10 medium (12) supplemented with 15% horse serum and 2 .5% fetal calf serum . The dishes were incubated at 37°C in a humidified atmosphere of 5% CO2 and 95% air .
Experiments designed to measure cell function were performed in the following way . Equal samples succinate ; C', complement ; GH, growth hormone . of a homogeneous suspension of cells were inoculated into a number of replicate dishes. Cells were grown for a minimum of 3 or 4 days before starting an experiment . Thereafter, medium, either with or without specific additions (such as HC or tissue extracts, see below), was added and changed every 1, 2, or 3 days . Dishes from which medium was saved for hormone assays were washed three times with 0 .15 M NaCl and stored at -20°C until cell protein was determined by the method of Lowry et al. (13) . Duplicate dishes rarely varied by more than 3% in total cell protein .
Assay Method for Prolactin
Rat prolactin was measured immunologically in culture medium or in cells disrupted with sonic oscillation by the method of complement (C') fixation (14) . This method is analogous to techniques previously described in detail which are used in our laboratories for the measurement of a variety of growth hormones (11,(15)(16)(17) and rat serum albumin (18) . The antiserum used in the present experiments was obtained in a single bleeding from a rabbit immunized with a total of 1 .0 mg of rat prolactin. The antigen was emulsified in complete Freund's adjuvant (Difco Laboratories, Inc., Detroit, Mich .) and injected in the toe pads and intramuscularly . The antiserum (Ra 41OC-2) was used in C'-fixation experiments at a final dilution of 1 :400 . No evidence for antibodies to contaminating substances was observed (see Results) when this antiserum was examined by double diffusion (19) or by C' fixation with large amounts of crude antigen (20) . The reproducibility of the immunoassay method for prolactin as performed in these experiments is f 200 % Culture medium for immunoassay was stored at -20°C . No loss of prolactin was detected during storage for periods of up to 5 months ; however, most assays were performed within 1-2 wk after collecting the medium . Samples were prepared for assay by dilution (1 :3 to 1 :25) in the C'-fixation buffer followed by heating at 60°C for 20 min to eliminate any anticomplementary activity in the medium . This procedure did not qualitatively or quantitatively affect prolactin in the medium . The prolactin standard was treated in the same manner .
Assay for Growth Hormone
Rat GH was assayed immunologically by C' fixation using monkey antiserum as described previously (1,11) . This assay method is specific for GH and does not detect rat prolactin. The reproducibility of the growth hormone assay is ±20% .
Preparation of Tissue Extracts
Extracts of four bovine (calf) tissues were prepared . The tissues used were hypothalamus, cerebral cortex, liver, and kidney . They were obtained at a local abattoir within seconds after death of the animal . They were transported in ice to the laboratory where they were processed within 1-2 hr . All tissues were handled in a similar manner .
A partially defatted powder was made by homogenizing the tissue with acetone (200 ml/gm fresh weight) at 4°C . After stirring with acetone for 18 hr, the insoluble material was removed by filtration. It was washed on the filter three times with fresh cold acetone and once with ether and then dried over phosphorus pentoxide. The dry powder was extracted by stirring with 0.1 N HCl (10 ml/gm) for 30 min at 25°C . The insoluble material was removed by centrifugation at 10,000 g for 30 min . The supernatant solution was the material added to culture medium .
The acidic extracts were added to medium in one of two ways . In one method, the pH of the extract was adjusted to 7.5 by the gradual addition of NaOH . The precipitate which formed on neutralization was removed by centrifugation, and the clear neutral solution was added to medium (1 part extract to 20-160 parts medium) . In the second method, the acidic extract was added gradually to culture medium with maintenance of the pH above 7 .2 by the simultaneous addition of NaOH. The final volume ratio of extract to medium was again 1 to 20-160 . As described previously, insoluble material was removed by centrifugation. Medium containing extracts was sterilized by filtration. Results obtained with extracts added to medium in the two different ways were qualitatively and quantitatively the same .
Demonstration of the Production of Prolactin by Rat Pituitary Cells in Culture
The C'-fixation curves obtained with antisera raised against prolactin and GH and their homologous antigens are shown in Fig . 1 . Fig. 1 also shows that GH did not fix C' with anti-prolactin, and that prolactin did not fix C' with anti-GH . Results of previous studies have shown the usefulness of the C'-fixation assay method for measuring GH production by rat (1, 3) and human (17,21) pituitary cells in culture . This method, using antiserum against rat prolactin, was thus employed to determine whether the rat pituitary cells produced prolactin .
The data in Fig . 2 show that material was pres- C'-fixation curves obtained with antiserum against rat prolactin (diluted 1 :400) and rat prolactin (•), crude rat pituitary extract (o), and medium from the GH3 strain of pituitary cells (A) . Fresh, uninoculated medium (o) did not fix C' with anti-prolactin . The rat pituitary extract was prepared by homogenizing 10 fresh pituitary glands in 3 ml of neutral 0.15 M NaCl. The insoluble material was removed by centrifugation (10,000 g, 20 min) and the clear supernatant solution was used without further fractionation . Starting with dilutions of this extract as low as 1 :4, only one peak of C' fixation was observed. ent in medium of GH 3 cells and in crude rat pituitary extract, but not in fresh medium, which fixed C' with anti-prolactin . Furthermore, the maximum C' fixed was the same for rat prolactin, GH 3 medium, and pituitary extract . These results indicate strongly that the same antigen is present in all three samples . The identity of the immune systems was also shown by double diffusion (Fig . 3) . Only one band of precipitation was seen with undiluted antiserum and prolactin, medium from determined . Medium containing added prolactin was placed in dishes which contained either no cells or GH3 cells . After a 3 day incubation period, the medium was collected and assayed for prolactin . The results (Table II) show that 92% of the prolactin originally added was recovered from the cell-free dishes and 86% from those containing GH, cells . Since medium was usually changed at least every 3 days in the experiments reported here, nearly all of the prolactin secreted into the medium during an incubation period was still present when the medium was collected and assayed .
Intracellular vs Extracellular Levels of Prolactin
Intracellular prolactin caused the same maximum amount of C' to be fixed with anti-prolactin as did either prolactin secreted into the medium or the prolactin standard . Intracellular levels and the rate of production of prolactin are shown in 2 By "rate of production" of prolactin or GH we mean the rate of appearance of either protein in the growth medium of the cells in culture (see [3] and Discussion) . A stock solution was made by adding rat prolactin to F 10 medium . 3-ml samples of the stock solution were added to two cell-free dishes and to two duplicate dishes containing GH3 cells . The remaining solution was frozen . Two duplicate dishes of GH3 cells which received only F 10 medium served as controls to determine the amount of prolactin produced by the cells . After a 72 hr incubation, the medium was removed from each dish and frozen . The collected media and the stock solution were then assayed for prolactin . The ranges of the results in duplicate dishes are shown . These results represent mean values of assays of duplicate cultures . Medium was changed and fresh medium was added for a 24 hr period . The cells were then scraped from the dishes, suspended in 3 ml of isotonic saline and treated for 5 min at 1-2°C in a Raytheon Model DF 101 sonic oscillator . After removal of samples for determination of protein, the cell sonicates and the 24 hr medium were assayed for prolactin . in medium was verified by an experiment with two inhibitors of protein synthesis . Fig. 4 shows that, following a 30 min preincubation with inhibitor, either cycloheximide or puromycin inhibited the rates of appearance of prolactin and GH in medium by at least 947 . In this experiment, incorporation of labeled amino acids into trichloroacetic acid-precipitable material was inhibited by 93 070 and 98 ,70 by cycloheximide and puromycin, respectively (3) .
Rate of Production of Prolactin by
Dif ferent Clonal Strains of Rat
Pituitary Cells
The results given in Table IV show that four of the five clonal strains examined produce at least as much prolactin as GH . One strain, GH 1 2C 1 , which is morphologically more spindle-shaped than the others (1, 2), appears to produce little or no prolactin .
Control of Prolactin Production
Much of our interest in these cells lies in their potential use as model systems in which to study Effects of inhibitors of protein synthesis on prolactin and GH production by GH3 cells . At zero time, fresh medium which had been equilibrated at 37°C in a 5% CO2 atmosphere was added to each of duplicate dishes . At 12 hr the medium was collected for prolactin and GH assay, and equilibrated medium containing either no additions, cycloheximide (10 µg/ml, 3 . 6 X 10 -6 M), or puromycin (200 ,ug/ml, 3 .7 X 10-4 M) was added . 30 min later this medium was removed and discarded, and fresh medium with the same additions was added. 12 hr later this medium was collected and saved for prolactin and GH assay, and the dishes were washed and frozen for cell protein determination . The control bars show the results without inhibitor . The treated bars show the results after exposure to the inhibitor .
THE JOURNAL OF CELL BIOLOGY . VOLUME 47, 1970 * The ratio of the rate of production of prolactin (P) to growth hormone (GH) . All cells were in the early stationary growth state (3) at the time these measurements were made . Medium containing hydrocortisone (HC) was added to GH3 cells . The characteristic stimulation (3) of the rate of GH production was observed (Fig . 5) . At about 110 hr, GH production was about eight times that in control cultures . In contrast to the effect on GH, HC in medium suppressed the production of prolactin . By 110 hr the rate of prolactin production in HC-treated cultures was only about 25 % that in controls . Table V shows that, in addition to its characteristic effect on the GH 3 strain, HC suppressed prolactin production in two other strains (GH 3 C 1 and GH 3C6) of pituitary cells . It is interesting to note that GH production by cells of the GH3C6 strain was not stimulated by HC . Further studies of this variant line are in progress .
The effects of various concentrations of HC on hormone production were examined . Medium containing HC at concentrations from 5 X 10 -10 M to 5 X 10-4 M was added to GH 3 cells . The relationship between dose and response is shown in Fig . 6 . Within the range tested, doses of HC which stimulated GH production suppressed the production of prolactin . In addition, it is noteworthy that the greater the stimulation of GH, the greater was the suppression of prolactin .
A series of experiments was undertaken in order to assess the usefulness of the functional rat pituitary cell system for studies of the action of hypo- Effects of HC on prolactin and GH production. Duplicate dishes were used for each point . At zero time, fresh medium either containing HC (3 X 10-6 at) or lacking HC was added to each dish . Medium was collected at intervals from HC-treated (0) and control (*) dishes and frozen for hormone assays . These dishes were washed and frozen for determination of cell protein. Cells were inoculated in replicate dishes, and medium was changed at least every 3 days . 8 days later, medium containing either no HC (-HC) or HC (+HC, 3 X 10 -5 a) was added . Media were changed approximately every 1-2 days thereafter . The results reported are for the interval 117-139 hr after adding HC .
thalamic factors which affect the release and possibly the synthesis of pituitary hormones (22) . The results of a representative experiment are shown in Fig . 7. Little or no effect of the hypothalamic extract on cell growth was observed ; however, extracts did have a marked effect on the morphology of the cells . Within 4 hr after adding medium containing extract the cells appeared to be more Effects of various concentrations of HC on prolactin and GH production. Conditions were similar to those described in Fig. 5, except that medium containing HC at final concentrations from 5 X 10-10 aI to 5 X 100 ' nt was added to experimental dishes (O), and medium lacking HC was added to duplicate control dishes (*) . Results are given for the interval 96-121 hr.
highly stretched (or adherent to the plastic surface), and no rounded-up cells could be seen . This effect persisted as long as the cells were grown in extract-containing medium.' The time-course of the effect of hypothalamic extract on prolactin production by GH3 cells was similar to the timecourse of stimulation of GH production by HC ( Fig . 5 and reference 3) . Likewise, the magnitude of the stimulation (6-to 9-fold) was also similar . In other experiments, in which shorter incubation times were used, no inhibition of prolacting production was detected in cells treated with hypothalamic extract for 2, 4, or 7 hr . In fact, a stimulation of prolactin production could be detected as early as 7 hr after adding medium containing hypothalamic extract .
The specificity of the effect of hypothalamic extract was then examined . Similar extracts were prepared from bovine cerebral cortex, liver, and kidney. The results, shown in Table VI, revealed that stimulation of prolactin production was not a specific effect of hypothalamic tissue . Extracts of 3 It is important to note that the morphological change observed does not appear to be a manifestation of a toxic effect of the extract on the cells . On the contrary, the cells appeared very healthy in extractcontaining medium for as long as 2 wk . This subjective observation was confirmed by the finding at the end of this time that treated cultures did not contain less protein than controls ; if anything, they contained more . values of duplicate determinations . The total protein concentration of control medium (medium without extracts added) was 12 mg/ml . Thus, the increase in total protein content of the medium due to tissue extracts was approximately 3-7% .
peak of C' fixation would probably have been seen (20) .
Second, medium from pituitary cells and rat
prolactin fixed the same maximum amounts of C' with anti-prolactin (Fig . 2) . Since small qualitative differences in the structures of proteins are often revealed by differences in the heights of their C'-fixation curves at equivalence (16,17), these results are strong evidence in favor of the conclusion that the material secreted by GH 3 cells into culture medium is rat prolactin .
Third, fresh uninoculated medium or medium from six other strains of cells did not fix C' with anti-prolactin ( Fig . 2 and Table I) .
Fourth, undiluted antiserum against rat prolactin gave only one band of precipitation in double diffusion with prolactin, crude pituitary extract, and medium from GH 3 cells (Fig. 3) .
These three bands merged without spur formation .
The rate of production (as defined in footnote 2) of either GH or prolactin by pituitary cells in culture can be measured directly . This quantity is the end result of three processes whose relative effects on the rate of production of either hormone are at present difficult to quantitate : synthesis, intracellular turnover, and secretion . Indirect measurements indicate that the rate of GH production by GH3 (3) . The findings that inhibitors of protein synthesis suppress prolactin production (Fig . 4) indicates that this may be true for prolactin as well . However, the intracellular level of prolactin in the GH 3 cells is equal to the amount produced in about 1-2 hr (see Results), while the comparable figure for GH is about % hr (3) . Thus it may be that the production and synthesis of prolactin are not so closely linked to each other as these two processes are in the case of GH .
In previous studies of pituitary explants, Nicoll and Meites (23) examined the effects of hydrocortisone on prolactin secretion in vitro . At concentrations of hydrocortisone of 0 .5 µg/ml they noted no effect on prolactin secretion . At 10µg/ml (2 .8 X 10-5 M) there was a decrease in prolactin secretion . Our observation that prolactin production was suppressed dramatically by 5 X 10 6 M hydrocortisone (Fig . 6) may be due to the greater sensitivity of the dispersed cell culture method .
Since each of the strains of pituitary cells used in these experiments was derived from a single cell, our results suggest that both prolactin and GH can be synthesized and secreted by the same type of pituitary cell . However, these results do not prove this point since all measurements to date have been made on mass cultures . It will not be possible to demonstrate this conclusively until it is shown that a single cell can synthesize both prolactin and GH . Likewise, since the cells used here are neoplastic, it is not possible to conclude that in the normal pituitary gland both hormones are produced by the same cell type .
Most evidence in mammals suggests that hypothalamic factors stimulate the release of GH from the pituitary gland and inhibit the release of prolactin (22) . However, one laboratory has presented evidence that there may also be a hypothalamic GH-inhibiting factor (22) . Our results with crude hypothalamic extracts, repeated in a number of independent experiments, revealed somewhat unexpected findings . We regularly observed a large stimulation of the production of prolactin and either no stimulation or a concomitant suppression of GH production . Since these effects were observed with extracts of several tissues (hypothalamus, cerebral cortex, liver, and kidney), they are clearly not due to the classical hypothalamic factors (22) . The nature of the prolactin-stimulating and GH-inhibiting materials in tissue extracts remains to be defined . Furthermore, knowledge about their physiological significance must await further studies in the living animal . Nevertheless, the observations that prolactin and GH production can be altered differentially by HC and tissue extracts indicate that these substances are useful reagents for further studies of the control of the biosynthesis and secretion of prolactin and GH in functional pituitary cells . These results also indicate that caution should be used in ascribing effects of crude brain extracts on pituitary function to specific hypothalamic factors .
The usefulness of the functional pituitary cell systems is greatly enhanced by the findings that the cells produce more than one organ-specific product . That these functional cell systems can be modulated or controlled selectively by the experimenter adds further to their use as model systems in which to study the integration of multiple differentiated activities in mammalian cells . Since HC and tissue extracts have distinct and opposite effects on the production of exportable proteins in pituitary cells, further studies of how these effects take place may suggest how integrated activities are controlled in complex, multipotent animal cells .
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v2
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2017-04-13T23:10:27.168Z
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1970-10-01T00:00:00.000Z
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10610557
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s2ag/train
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Absence of alkaline phosphatase in rat thymic lymphoma induced by murine leukemia virus.
Summary Alkaline phosphatase activity has been determined by a histochemical assay on thymic lymphomas induced by murine leukemia virus in C57BL mice and W/Fu rats. Approximately 60% of the former and none of the latter tumors showed this activity in the plasma membrane of the tumor cells. The possibility that the enzyme “activation” represents expression of a derepressed cell gene rather than of a viral gene is discussed.
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v2
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2018-04-03T02:30:07.626Z
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1970-10-01T00:00:00.000Z
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33880306
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s2ag/train
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Tumors of the optic nerve and optic chiasm.
✓ In a series of 20 cases of glioma of the optic nerve, approximately 25% were successfully treated surgically. This series also confirms the observations of Taveras, et al., (1956) that 25% of patients thus treated obtain considerable additional improvement in vision after radiation therapy, and that another 10% derive minimal benefit.
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v2
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2018-04-03T02:57:51.422Z
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1970-10-01T00:00:00.000Z
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35716562
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s2ag/train
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Amplitude-averaged A-scan echoencephalography of a mental hospital population.
Physicians who work in mental hos pitals are aware that amongst the patient population there is a percentage with organic cerebral disease whose sympto matology presents more in the form of disturbed behaviour rather than loss of motor or sensory function. Most of these cases of organic cerebral disease are due to conditions for which no radi cal treatment exists. However, a few may result from benign brain tumours or subdural collections of blood which are potentially capable of surgical cure. The conscientious psychiatrist is always alert to the possible presence of these cases in his practice. Unfortunately, since many of these benign and surgically removable tumours are extracerebral they usually do not disclose their pre sence by causing obvious neurological deficits. Thus any simple test which would help psychiatrists to identify pa tients with space-occupying cerebral lesions might be of considerable assis tance to them.
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v2
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2018-04-03T03:41:07.365Z
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1970-10-01T00:00:00.000Z
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7580174
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s2ag/train
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Combination chemotherapy in the management of breast cancer metastases
The method of combined chemotherapy is based on the assumption that the simultaneous injection of combinations of divergent action (antimetabolites that detain the inclusion of some nucleonic acids in the RNA of tumor cell and alkylating agents that react with the phosphate groups of DNA of tumor cell) leads to the synergistic action of these agents. The treatment of 31 patients with mostly hematogenous metastases gave objective remission and stabilization of the process in 22 cases in 13 cases of this series (2 lung metastases, 8 bone metastases, and 3 cerebral metastases), the complete reduction of metastatic foci was attained. The general doses were 4.5g–5.5g of 5‐FU and 4.0 g–6.0 g of cyclophosphamide. No serious complications were noted. The repeated courses of chemotherapy must be performed every 6‐8 weeks, even in cases of remission.
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v2
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2022-10-27T15:04:47.256Z
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1970-10-01T00:00:00.000Z
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253146663
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s2ag/train
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Relation of Intestinal Carcinoid to Renal Hypertension
Blalock’ showed in dogs that superior mesenteric artery insufficiency alone does not lead to hypertension but in the presence of renal disease does lead to hypertension.2 These findings were later confirmed in humans,3 and it mas suggested that superior mesenteric artery insufficiency potentiated renal hypertension through a release of serotonin from the ischemic intestine: To test this suggestion, me have studied the incidence of hypertension and of renal disease among patients with gastrointestinal carcinoid tumors. Such patients were felt to represent a proper physiological model, since they release serotonin in elevated amounts into their portal c i rc~la t ion .~
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v2
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2019-03-12T13:03:18.216Z
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1970-10-10T00:00:00.000Z
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73878152
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s2ag/train
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Double-blind or Not?
SIR,-I should like to draw the attention of your readers to two therapeutic trials, in Wilms's turnour (nephroblastoma) and neuroblastoma, currently being undertaken by the Medical Research Council's working party on embryonal tumours in childhood. The trial of treatment of neuroblastoma is designed to investigate whether the regression that sometimes occurs in this disease is a consequence of an immune reaction developed against the tumour, and if so whether this immunity can be increased by immunotherapy. There is experimental evidence that neuroblastomas contain tumourspecific antigens against which an immune reaction may be stimulated,' and also that the immune system is more likely to succeed in eradicating a tumour when the number of residual malignant cells in the body is low.2 It is therefore important that immunotherapy should follow a period of chemotherapy, and in this trial it is proposed to treat patients with vincristine and cyclophosphamide for this purpose, after initial surgery and radiotherapy if indicated. The working party considered that the most suitable groups of patients for such a trial are as follows: (1) all patients over the age of one year with neuroblastoma, except those with a primary lesion confined to the cervical region; (2) all patients under the age of one year with metastatic disease. The trial of treatment in nephroblastoma is designed to assess the relative efficacy of vincristine and actinomycin D as agents in the treatment of nephroblastoma after surgery and radiotherapy. There is now increasing evidence' that the prognosis of nephroblastoma is improved by the use of actinomycin D for periods of two years following surgery and radiotherapy. There is also evidence' that vincristine, a drug which is relatively less toxic than actinomycin D, is efficacious in treating metastatic disease. It is therefore planned to conduct a controlled clinical trial in children over the age of one year with stage I, Ha, and IIb (American classification) disease in an attempt to compare the effectiveness of the two drugs in the long-term treatment. Further information may be obtained from the secretaries of the working party, Dr. P. Morris Jones (at the Royal Manchester Children's Hospital, Pendlebury, Manchester, M27 1HA) and Dr. Dorothy Pearson (Christie Hospital and Holt Radium Institute, Withington, Manchester, 20). I would, of course, be very happy to discuss these trials with any clinician who is asked to treat patients with either of these conditions, and who feels they might be suitable for these trials.-I am, etc.,
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v2
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2018-04-03T02:30:53.775Z
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1970-10-31T00:00:00.000Z
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34029502
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s2ag/train
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Genital herpes and cervical cancer.
and the monitoring unit may harbour the virus if the components are contaminated by infected blood, and usually several patients are maintained by one machine regardless of the type of dialyser used. The argument that disposable dialysers would reduce the incidence of infection has not been borne out in fact. One of the largest outbreaks with over 80 cases occurred in Stockholm when disposable dialysers were in use.2 More recently, a higher incidence of antigen-positive patients has been reported from a unit using disposable dialysers compared with a unit using Kiil dialysers.'3 Nevertheless, when the Kiil dialyser is used each patient should have his own dialyser. Until effective immunization can be given to staff-which implies the isolation of the virus and the production of a vaccine-the high incidence of morbidity and mortality among staff working in renal units justifies serious consideration for industrial compensation awards to all those who have contracted hepatitis while working in dialysis units. Moreover, the introduction of "danger money" for staff working in them should also be considered.
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v2
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2018-04-03T02:33:05.027Z
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1970-11-01T00:00:00.000Z
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20022177
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s2ag/train
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Induction of thymic lymphosarcoma and mammary adenocarcinomas in rats by oral administration of the antitumor agent4(5)‐(3,3‐dimethyl‐l‐triazeno)imidazole‐5(4)‐carboxamide
4(5)‐(3,3‐dimethyl‐l‐triazeno)imidazole‐5(4)‐carboxamide (DICNSC 45388)and anticancer drug with activity against rodent and human tumorswas tested for carcinogenic activity by feeding a mean cumulative dose of 740 mg/rat/14 weeks to 24 female Sprague‐Dawley weanling rats. The first mammary tumor was palpated 10 weeks after the start of feeding DICand by 18 weekswhen the experiment was terminatedall 24 rats had developed an average of 5 mammary adenocarcinomas. Lymphosarcoma was present in the thymus of all rats and in the spleen (20/24)lymph nodes (18/24)and bone marrow (12/24). Ependymomas of the brain were present in 9 rats and pulmonary alveolar carcinomas in 4 rats. No tumors were found in the negative control group of 24 rats. DIC appears to be a potent chemical carcinogen that may exert its carcinogenic activity by the alkylation of biopolymers.
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v2
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2018-04-03T03:29:28.651Z
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1970-11-01T00:00:00.000Z
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6326062
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s2ag/train
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Elevation of leucine aminopeptidase in disseminated malignant disease
Leucine aminopeptidasea proteolytic enzyme present in most human tissueshas been studied in 90 patients with various types of malignant disease and compared with a group of 25 normal controls and 38 patients with various non‐malignant diseases. Levels were measured in serum and 24‐hour urine specimens by a colorimetric method. Results showed elevation of LAP values in 24‐hour urine specimens in all 16 cases of disseminated GI tract neoplasms19 of 20 cases with disseminated bronchogenic carcinomaall 6 cases of disseminated cancer of the prostateall 9 cases of invasive malignancy of the GU tractand 12 of 15 cases of various hematologic malignancies. (Two patients had CLL; lymphocytes do not produce the enzyme.) Serum levels (vs. urine levels) were not as consistently elevated. Seventeen patients with localized or surgically cured malignancies had normal LAP values. in only 3 of 22 patients with nonmalignant disease was elevation of LAP found (excluding cases with liver or pancreatic diseaseknown to show increased values by previous study of leucine aminopeptidase). It is concluded that urine LAP may be of value in estimating the extent of tumor and success of therapy.
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v2
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2018-04-03T05:32:15.031Z
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1970-11-01T00:00:00.000Z
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43208165
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s2ag/train
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Intracranial removal of pituitary adenomas. An evaluation of varying degree of excision from partial to total.
✓ The effects of varying degrees of completeness of intracranial excision of benign pituitary adenomas among 64 patients operated on by members of the UCLA neurosurgical faculty and resident staff were assessed as to their influence upon tumor recurrences and operative mortality and morbidity. The recurrence “rate” was 9.4%. The operative mortality was 5.9%. There were lower mortality and recurrence rates among those patients treated by radical “total” excision techniques. It is not possible to predict in advance which patient will suffer a recurrence. Recurrence cannot be selectively predicted when tumor is left in place at the time of the first definitive operation. The authors believe that most benign pituitary adenomas can be radically excised and that neurosurgeons should not be content with decompressive procedures or partial removals.
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v2
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2017-09-01T15:42:24.096Z
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1970-11-21T00:00:00.000Z
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12467275
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s2ag/train
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Immunological treatment of leukaemias.
tumour and host indiscriminately) but might be followed by some other type of directed attack. The list of suggestions relating to turnours with specific, or as we should now say, associated antigens, can now be filled out a little. Following the work of Professor Alexander and his colleagues one should, for example, add injection of RNA extracted from immune lymphoid cells-but in general, with a little juggling, the procedures which have been enumerated by Professor Mathe can be fitted quite well into this framework. Here again, however, while the list of theoretical possibilities remains much the same, considerable advances have been made, and we are in a much better position today than we were even a few years ago to choose the right strategy in planning experiments and even to some extent in treating patients.
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v2
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2018-04-03T00:10:40.961Z
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1970-11-21T00:00:00.000Z
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9358623
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s2ag/train
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Evidence for antigenicity in human tumours with reference to both melanoma and acute leukaemia.
There is now no doubt that tumour-associated antigens exist in experimental animal tumours, and that immunological reactions against these antigens can influence the course of the malignant disease.' Because of the difficulties of research in man, the situation is not as clear as in animals. Nevertheless, recent work has shown that tumour-associated antigens are present in human malignant tissue. The two diseases selected for special discussion are malignant melanoma and acute leukaemia.
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v2
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2018-04-03T01:06:45.885Z
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1970-12-01T00:00:00.000Z
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28003848
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s2ag/train
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A comparison of the response of tumour and normal tissue in the mouse exposed to single doses of fast neutrons or electrons.
Abstract Spontaneous mouse tumours were exposed to single doses of fast neutrons or fast electrons. Their response was compared with the damage caused to the overlying skin to obtain a measure of the therapeutic ratio for fast neutrons. At low doses the neutrons showed a large therapeutic gain, which reduced to unity (i.e. no gain) for large doses. This result is discussed in terms of the proportion of hypoxic cells and oxygen concentrations in the two tissues.
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v2
|
2018-04-03T02:28:58.079Z
|
1970-12-01T00:00:00.000Z
|
33869336
|
s2ag/train
|
The Significance of Spontaneous and Positional Nystagmus Recorded by Electronystagmography
There has been little agreement about the pathogenesis of spontaneous and positional nystagmus. Barany suggested that positional nystagmus is induced by otolith organ disease," while Nylen proposed that it might be of peripheral, labyrinthine or central origin. 26 Hansson and Nylen'" examined six patients with intracranial tumors who had positional nystagmus, none of whom showed evidence of labyrinthine disease. They concluded that, in these cases, the positional nystagmus was a result of the tumors. Some investigators have demonstrated that cerebellar lesions in animals cause positional nystagmus.1.10 •11 ,27 Miehlke-! induced positional nystagmus in laboratory animals by labyrinthine irritation while Gutman et al.!" induced it with drugs, and concluded that it was central in origin.
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v2
|
2018-04-03T04:53:11.782Z
|
1970-12-01T00:00:00.000Z
|
40784086
|
s2ag/train
|
Dermoid tumors of the spinal cord.
✓ This is an analysis of 10 cases of dermoid tumor occurring in the spinal canal (8 lumbar and 2 thoracic). Low-back pain was the commonest presenting symptom, especially if the tumor was adherent to the conus medullaris. Other complaints included urinary dysfunction and motor and sensory disturbances of the legs. Clinical and radiological evidence of spina bifida was found in about half of the cases and suggested the diagnosis of a developmental type of tumor when patients presented with progressive spinal cord compression. At operation, the tumors were often found embedded in the conus medullaris or firmly adherent to the cauda equina, thus precluding complete removal. Evacuation of the cystic contents, however, gave lasting relief of the low-back pain and did not cause any deterioration in neurological function. In a follow-up study, ranging from 1 to 15 years, virtually no improvement in the neurological signs was observed. On the other hand, only one case has deteriorated due to recurrence of tumor g...
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v2
|
2018-04-03T00:24:13.886Z
|
1970-12-05T00:00:00.000Z
|
11265405
|
s2ag/train
|
Health services financing.
unwarranted. I recently had in my care a patient from eastern Europe sent for investigation of a suspected haemoglobin anomaly.3 It turned out that this patient was taking huge amounts of phenacetin-containing analgesics, which were never found on him but which he stopped taking-as proved by the above urine test-when threatened with being returned to his country with the diagnosis of a grave psychiatric abnormality. Screening large numbers of persons in Switzerland for Nacetyl-p-aminophenol in urine has shown that up to 10%O of a given population is taking phenacetin-containing analgesics.3 Intake of salicylate on its own is rare in Switzerland. Only two of five leading brands4 contain 0-125 g. and 0-37 g. In addition, it seems important that patients who have regularly abused analgesics containing phenacetin should have their urinary tract searched for tumours at necropsy. Within the last year five of 625 women regularly taking analgesics containing phenacetin died while under close observation, and one developed a carcinoma of the bladder.5 This tends to confirm the findings of Bengtsson6 and underlines the appeal by Dr. Koutsaimanis and Professor de Wardener that phenacetin should be sold only on prescription, although the evidence for an increased incidence of tumours of the urinary tract after many years' intake of phenacetin-containing analgesics is so far inclusive.-I am, etc., U. C. DUBACH.
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v2
|
2019-03-08T14:21:30.994Z
|
1970-12-26T00:00:00.000Z
|
71238697
|
s2ag/train
|
On the Cancer Trail
This is rather a dismal book about a dreary subject and, as is almost inevitable when more than 20 contributors collaborate to write essays about aspects of the same topic, there is a good deal of tedious repetition. The main conclusion is that death is a researchable phenomenon and that further research will enable us to die more reasonably and even lead us to live more reasonable lives. That no doubt is a consummation devoutly to be wished, but I remain sceptical because fundamental problems of human life and death are decided more by sentiment, passion, and religious faith than by reason. Nowhere do these authors face the crucial question that confronts a dying man if he be capable of thought and reflection. Is his approaching death the prelude to a changed form of continued existence, as St. Paul believed when he wrote cheerfully to the Corinthians of the time when what is mortal will be clothed in immortality and death will lose its sting and the grave its victory? Or is his death no more than simple extinction and the end of human activity-of no greater significance than the death of a single cell in a complex biological system which will soon replace it? Elizabeth Ross. a psychiatrist, comes nearest to this heart of the matter in her touching description of the help she was able to bring to a distressed young negro girl on her death bed, and Andie L. Knutson gives two pages to it before she turns to :oiolog cal themes. Most of these essays are almost entirely concerned with what may not unfairly be described as problems on the fringe of individual death: the financial cost, the impoverishment of a family, the legal problems, and the personal burden of the care of the dying so graphically described in bitter verses by W. P. Snodgrass after nursing a paraplegic incontinent for "seven wasted months." In this century there have been great changes but the facts are simple. Not long ago death was a domestic family affair; infants and young children died so often that few families escaped experience of it. Immense improvement in the survival rate of the young has made death relatively rare in the home and families now prefer to entrust the terminal care of their relatives to institutions. In America two thirds of all deaths occur in nursing homes or hospitals, and the dying have become "raw material for institutional industry" often carried on for profit. The conditions in those institutions are a proper subject for sociological inquiry, and the investigators might be better equipped for their work if they prepared themselves by nursing such patients for a year or two. Death is no longer an instantaneous event; it is a process, and in many cases modern treatment notably prolongs it and in so doing imposes heavy burdens on individuals and society. That gloomy fact justifies the effort put into this book. I wish the discussion on euthanasia had received more attention.
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v2
|
2017-04-14T20:39:07.217Z
|
1971-01-01T00:00:00.000Z
|
17789282
|
s2ag/train
|
Airway difficulties associated with anaesthesia in acromegaly. Three case reports.
A 50-year-old female was admitted to the Yale-New Haven Medical Center because of acromegaly. She was well until 7 years prior to admission when she had noticed the gradual onset of hoarseness, the need for increasing sizes of gloves and shoes, and tingling in both hands. Two years prior to admission polyps had been removed from her vocal cords following which there was some improvement in her hoarseness. One year prior to admission fasciotomy had been performed for left carpal tunnel syndrome. Several months earlier she had consulted a dentist because of widening of the gingival space between her teeth. Endocrinological examination including pneumoencephalography and carotid arteriography revealed a pituitary tumour. The diagnosis of acromegaly was made and the decision was made to treat her by trans-sphenoidal hypophysectomy. On admission, physical examination revealed: weight 66 kg, height 160 cm, blood pressure 100/70 mm Hg, pulse 88 beats/min and regular, temperature 37.0°C, increased finger width, large nose, moderate prognathism, spreading of lower teeth, and large tongue. Preoperatively she was given cortisone acetate and she was scheduled for a trans-sphenoidal hypophysectomy under general anaesthesia. Premedication consisted of morphine sulphate 10 mg, hydroxyzine hydrochloride 75 mg and atropine 0.4 rag. Anaesthesia was induced with intravenous sodium thiopentone 250 mg and 70 per cent nitrous oxide in oxygen. Following oxygenation with 100 per cent oxygen, and after confirming that manual positive pressure ventilation could deliver adequate tidal volume, suxamethonium chloride 50 mg was administered intravenously and endotracheal intubation, using a size 3 Macintosh laryngoscope, was attempted. The glottic opening could not be visualized with the patient's head in Jackson's "classical" extended position (Jackson, 1913). Therefore, the head was placed in a "sniffing" position, the position, described by Jackson and Jackson (1934) and referred to as the "amended" position (Gillespie, 1948), in which the head is raised about 10 cm above the level of the table and is then slightly extended at the atlanto-occipital joint. In this position the distance from the teeth to the glottis is shortened. In addition the larynx is brought more posteriorly in relation to the position of the laryngoscope. This manoeuvre barely enabled visualization of the posterior portion of the larynx of this patient. It was noted that her tongue was massive, the epiglottis was thickened, and visualized posterior portion of ventricular folds and vocal cords were enlarged with an extremely narrow opening between the vocal cords. An endotracheal tube with external diameter of 11 mm was inserted with much difficulty. Immediately before the surgical incision, the right nostril was packed with gauze soaked in 4 ml of 0.25 per cent phenylephrine, and 3 ml of 1:100,000 adrenaline was injected subcutaneously along the site of incision for haemostasis. Anaesthesia was maintained with 70 per cent nitrous oxide in oxygen, intravenous morphine sulphate 10 mg and tubocurarine 45 mg. Hydrocortisone 100 mg was injected intravenously. The intra-operative course was uneventful. At the conclusion of the procedure neostigmine 3 mg and atropine 1 mg were administered intravenously. Before removal of the endotracheal tube, the patient's tidal volume was 400 ml, and her maxi-
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v2
|
2017-07-29T22:38:33.107Z
|
1971-01-01T00:00:00.000Z
|
20146027
|
s2ag/train
|
Evidence of the Participation of Deoxycholate in Cancer Immunity
The hypothesis of cancerostatic activity of deoxycholic acid, recently outlined, is supported by correlation of natural cancer resistance with the level of deoxycholic acid in animals and humans. Analyses of sera indicate lower levels of unconjugated deoxycholic acid in cancer patients, the mean values of other bile acids being normal. Application of this theory to statistics of cancer incidence reveals possibilities of new aspects.
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v2
|
2017-08-16T05:16:17.069Z
|
1971-01-01T00:00:00.000Z
|
6759108
|
s2ag/train
|
Cytologic studies of tumors. L. clonal proliferation of four stemlines in three hematopoietic tissues of a patient with reticulosarcoma.
A case of reticulosarcoma was found to have four chromosomally different stem-lines in peripheral blood, lymph node and bone marrow. The four lines are recognized to be of monoclonal origin on the basis of the closely allied karyotypes characterized by trisomy for E16, E17 and E15, the loss of one A1, two F and two to four C elements in addition to M and R markers. The markers characterize three kinds of hematopoietic tissues: an M1, R1, R2 line occurs in lymph node, and an M1, M2, M3, R1 line in peripheral blood and M1, M4 and M1, M2, M3 lines in bone marrow. Cytogenetic variability of malignant cells was highest in peripheralblood. Information was provided to suggest that of the four stemlines, the lymph node line may be original, the peripheral blood line may be a derivative of the lymph node line and, finally, two marrow lines may have originated from the blood line or from one of the mutated cells slightly different from the marrow lines. The M markers were discussed in relation to malignant evolution of hematopoietic cells of this patient. The suggestion was made that the chromosomes of the patients with malignant hematopoietic disorders should be examined in different tissues.
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v2
|
2017-09-25T09:56:26.407Z
|
1971-01-01T00:00:00.000Z
|
13593784
|
s2ag/train
|
pH as a determinant of cellular growth and contact inhibition.
1) Both the growth rate and the maximum population density of several normal, virus-transformed, and cancer cells were markedly pH-dependent; the optimum varied from pH 6.9 to 7.8. At the optimum pH, some diploid human cells attained population densities comparable to those of cancer or virus-transformed cells. Contact inhibition of growth is facilitated by repeated fluctuations of pH in nonphysiological ranges, and may not be an intrinsic and necessary attribute of diploid cells in culture. 2) At pH 8.3, at which there was little or no cellular multiplication, the protein content per cell increased 2- to 5-fold over a period of 10-16 days, and was slowly reversed to normal concentrations on restoration of pH to the optimal range. 3) Uridine uptake by contact-inhibited human cell cultures was stimulated by refeeding with salt solution, and to the same extent as by complete (serum-supplemented) growth medium; that immediate increase did not involve the reinitiation of cellular growth and multiplication. Contact inhibition was, however, reversed in 2-4 days by an appropriate increase in the serum concentration of the medium.
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v2
|
2018-04-03T00:30:52.819Z
|
1971-01-01T00:00:00.000Z
|
12499607
|
s2ag/train
|
Enhancement of radiation effects by chemotherapy.
This review covers the basic rationale for and the clinical experience with the use of chemicals for enhancement of ionizing radiation effects on ma1ignant tissues. Chemical sensitization of cells to ionizing radiation was demonstrated in cell cultures and in experimental animal systems. It remains to be determined how best to utilize this sensitization for the benefit of patients with malignant tumors. (SW)
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v2
|
2018-04-03T00:44:23.038Z
|
1971-01-01T00:00:00.000Z
|
26444475
|
s2ag/train
|
MECHANISM AND MANAGEMENT OF ANEMIA IN MALIGNANT DISEASE *
The more common causes of anemia in malignant disease are discussed. Of 78 patients requiring transfusions on the Oncology Service of the University of Wisconsin Medical Center during the period December 1968–May 1969, records were available on 65. Gross blood loss was the most common cause of the anemia (44 cases); next was suppression of the bone marrow by chemotherapy (27 cases) or radiation therapy (8 cases); tumor spread to bone marrow (18 cases); infection (15 cases); uremia (5 cases); and poor nutrition (5 cases). Directions are given for evaluation of the patient.
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v2
|
2018-04-03T02:05:33.760Z
|
1971-01-01T00:00:00.000Z
|
32159641
|
s2ag/train
|
Therapeutic effect and toxicity of adriamycin in patients with neoplastic disease
Adriamycin is a hydroxymethyl analog of daunorubicin with antitumor effect in man. We have studied 86 patients: 44 with acute leukemia (27 children and 17 adults), and 42 solid tumors (20 children and 22 adults). Objective response was seen in 1 of 1 Wilms' tumor, 5 of 8 neuroblastomas, 2 of 3 Ewing's sarcomas, 4 of 5 reticulum cell sarcomas; 3 of 9 osteogenic sarcomas, 3 of 6 bronchogenic carcinomas, and 1 of 1 lymphosarcoma. Complete remission (M‐1 marrow) was seen in 1 of 14 acute myelocytic leukemias. Of 30 acute lymphocytic leukemias, 5 had complete and 1 had partial remission. Responses lasted from 0.25 months to 10+ months with a median of 3 months. Except for patients with osteogenic sarcomas and bronchogenic carcinomas, all received prior chemotherapy. Major toxicity of adriamycin included granulocytopenia, lymphocytopenia, thrombocytopenia, anemia, marrow hypoplasia, stomatitis, vomiting, and alopecia. Activity of adriamycin in these patients with advanced disease supports its exploration in patients earlier in their therapeutic course.
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v2
|
2018-04-03T02:21:40.346Z
|
1971-01-01T00:00:00.000Z
|
21474398
|
s2ag/train
|
OBSERVATIONS ON THE ROLE OF THE FETAL ADRENAL GLAND IN STEROIDOGENESIS DURING DIABETIC PREGNANCY
Clinical and endocrinological findings are reported in a patient with diabetes mellitus who was subjected to bilateral adrenalectomy for adrenal hyperplasia and to removal of 80 per cent of the pancreas on account of an islet cell tumour. The patient subsequently became pregnant as a result of treatment with Pergonal (Serono) and human chorionic gonadotrophin (HCG).
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v2
|
2018-04-03T02:37:18.864Z
|
1971-01-01T00:00:00.000Z
|
34281441
|
s2ag/train
|
Clinical study with bleomycin
Bleomycin is an antitumor antibiotic produced by Streptomyces verticillus. Seventy‐five patients with various neoplasms were studied using this drug. Fourteen out of 20 patients with epidermoid carcinoma of the head and neck region, 5 out of 14 cases of lymphoma including Hodgkin's disease, 3 out of 6 patients with testicular tumors, and one patient with lymphangiosarcoma of the arm showed evidence of objective regression. Common side effects encountered were hyperthermic reactions, gastrointestinal disturbances, hyperkeratosis and vesiculation of fingers, alopecia, and stomatitis. Pulmonary fibrosis is a rare but serious complication. One patient in this series died of this complication. There was no evidence of bone marrow, liver, or renal toxicity. Bleomycin promises to be a useful therapeutic agent and merits further study.
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v2
|
2018-04-03T02:42:57.640Z
|
1971-01-01T00:00:00.000Z
|
34822709
|
s2ag/train
|
Long term follow-up of patients with menorrhagia treated by irradiation.
Abstract Two thousand and forty-nine patients treated for menorrhagia by ovarian irradiation at the Christie hospital in the period 1946–60 have been followed-up for an average of 14·6 years. The number of deaths occurring from different causes has been compared with the expected number, taking age, calendar period and region of residence into account. There was a slight excess of deaths from all causes, an excess of deaths from leukaemia, pelvic cancer, and coronary artery disease, but the excess was not significant at the 5 per cent level; the number of deaths from breast cancer was significantly below the expected figure. When examined by interval since irradiation, there were three deaths from leukaemia five to nine years after treatment compared with an expected figure of 0·37; this excess is significant at the 1 per cent level. Operative treatment by hysterectomy has a mortality of about one or two per 1,000 patients; the appropriate treatment can only be determined by clinical assessment of each pa...
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v2
|
2018-04-03T03:09:14.906Z
|
1971-01-01T00:00:00.000Z
|
764554
|
s2ag/train
|
Treatment of metastatic breast cancer with a combination of adrenalectomy and 5‐fluorouracil Progress report
Adrenalectomy has become the primary therapy for women with metastatic cancer of the breast at the Peter Bent Brigham Hospital. The objective response rate for a minimum of 6 months in 177 patients has been 58%. For the past 3 years, 5‐fluorouracil has been administered in the immediate postoperative period and this combined approach has particularly benefited those women with a free interval under one year and those with serious visceral disease. The response rate for women with no free interval has risen to 70% with this regimen. The distribution of responses in various types of metastatic patterns, particularly visceral disease, is presented and the efficacy of the combination of adrenalectomy and 5‐fluorouracil is demonstrated.
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v2
|
2018-04-03T03:13:35.845Z
|
1971-01-01T00:00:00.000Z
|
1230376
|
s2ag/train
|
Bioassay and radioimmunoassay of plasma gastrin in a case of Zollinger-Ellison syndrome.
Fasting plasma gastrin levels were measured in a patient with the Zollinger-Ellison syndrome by both bioassay and radioimmunoassay. The level remained constant following total gastrectomy, but fell sharply following parathyroidectomy. Although the bioassay gave gastrin levels which were consistently 2 to 3 times higher than those obtained by radioimmunoassay, the values showed a similar trend. However, both methods gave almost identical results for the gastrin contents of antral mucosa and pancreatic tumour samples from the patient. It is suggested that biologically active gastrin-like substances not detectable by radioimmunoassay were present in the patient's plasma.
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v2
|
2018-04-03T03:19:12.842Z
|
1971-01-01T00:00:00.000Z
|
2399884
|
s2ag/train
|
The phenomenon of nucleolar segregation in some lesions of the thyroid cell.
Study in the electron microscope of certain human thyroid lesions showed that the phenomenon of nucleolar segregation is comparatively frequent in sporadical or diffuse nodular goitres, in familial goitres and cancer of the thyroid. The reorganization and redistribution of the nucleolar material, reflecting deep alterations in the metabolism of ribonucleic acid, are proper to hypofunctional thyropathies. The intensity of segregation increases in proportion to neoplastic transformation of the thyroid cell.
|
v2
|
2018-04-03T03:19:52.514Z
|
1971-01-01T00:00:00.000Z
|
2522774
|
s2ag/train
|
Patient survival after chemotherapy and its relationship to in vitro lymphocyte blastogenesis
To study the relationship between chemotherapy immunocompetence and prognosis, in vitro lymphocyte blastogenic responses were studied serially, in 40 patients, receiving intensive chemotherapy for metastatic solid tumors. Suppression of lymphocyte blastogenic responses to phytohemagglutinin and streptolysin “O” was similar in all patients at the end of chemotherapy and was highly significant (PHA: P < 0.01, SLO: P < 0.02). Recovery of such responses occurred with significant overshoot above the pretreatment levels (P < 0.01) for PHA and SLO in those patients whose tumors regressed and survival was long, while such recovery was lacking in those patients whose tumors progressed and whose survival was short (PHA: P < 0.01, SLO: P < 0.05). This shows that the rebound with overshoot of immunologic reactivity after chemotherapy correlates with tumor regression and prognosis, and continued suppression may be an indicator of poor prognosis.
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v2
|
2018-04-03T03:32:10.390Z
|
1971-01-01T00:00:00.000Z
|
6571854
|
s2ag/train
|
Experimental occlusion of the renal circulation in the dog.
The renal artery circulation was occluded in one kidney in each of 9 dogs by the injection of autologous striated muscle tissue suspension into the renal artery. In 7 of the dogs an injection of 30% glucose was added. The injections were not followed by any spontaneous death or other unwanted effects. Functional, histological and micro-angiographical examinations showed that particularly the use of muscle tissue and glucose will result in massive thrombotic occlusion of the renal artery system with complete arrest of the renal artery blood flow and maximum necrosis of the kidney parenchyma. The tissue along the cortico-medullary border may partially survive, probably due to the existence of collateral vascular pathways. No blood pressure elevations were recorded.The results suggest that the method of injections may be of value in the treatment of human cases of renal adenocarcinoma by improving the operability of large tumours and by reducing the tumour load.
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v2
|
2018-04-03T03:57:07.641Z
|
1971-01-01T00:00:00.000Z
|
37231974
|
s2ag/train
|
Telecobalt therapy for carcinoma of laryngopharynx.
1. In small lesions, T1 and T2, of the laryngopharynx, telecobalt therapy gives as good results as the combination of surgery anti pre- and postoperative telecobalt therapy.2. On the other hand, in larger lesions, T3 and T4, surgery supplemented by radiotherapy seems to be the best treatment.3. Surgery after telecobalt therapy in carcinoma of the laryngopharynx is difficult. This must be kept in mind when designing a preoperative irradiation program. The dose in curable lesions should not exceed 3,000 r, with a weekly dose of 1,000 r.4. Radiosensitivity of laryngopharynx cancers varies greatly from one patient to another. However, the best chance of cure is afforded by doses between 6,500 and 7,500 r.
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v2
|
2018-04-03T04:13:06.120Z
|
1971-01-01T00:00:00.000Z
|
38130813
|
s2ag/train
|
Vasoactive substances in Kaposi's sarcoma
Nine patients with Kaposi's sarcoma had tumor tissue, blood, and urine examined for the presence of 5‐hydroxytryptamine (5HT), histamine, catecholamines, and prostaglandins to determine if an overproduction of any of these substances might be associated with some of the clinical features of the tumor. The features vary from pricking pains, itching, and increased local sweating to edema of the affected limb. In addition, a small percentage of patients develop gastrointestinal symptoms, such as abdominal pain and diarrhea. The results show that 5HT, histamine, and catecholamine concentrations were within normal limits. But prostaglandin‐like materials was found in all Kaposi's sarcoma tissue tested. The presence of this substance may explain the occurrence, in some patients with Kaposi's sarcoma, of persistent abdominal pain and diarrhea.
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v2
|
2018-04-03T04:24:01.239Z
|
1971-01-01T00:00:00.000Z
|
38858895
|
s2ag/train
|
The natural history of primary carcinoma of the liver.
Ninety-two patients with primary liver cancer were studied in retrospect; 39 of them were solely laparotomized. These were considered to expose the natural course of the disease. The mean survival was less than one month. The survival did not correlate to amount of tumour, type of tumour, age, coexistence of cirrhosis, or elevated alkaline phosphatase, but it did to hyperbilirubinemia. Only 10% of all the patients could be considered as candidates for liver resection. This operation was performed in 5 patients, 3 of them being alive after 12, 24, and 126 months.
|
v2
|
2018-04-03T05:01:03.615Z
|
1971-01-01T00:00:00.000Z
|
41257244
|
s2ag/train
|
The effect of 5‐fluorouracil on small bowel mucosa
Pre‐ and post‐therapy small bowel biopsies were obtained in 19 of 20 patients who received 5‐fluorouracil for treatment of their malignant disease. Three parameters were evaluated: clinical response to therapy, which occurred in five cases (26%); development of gastrointestinal toxicity, which occurred in 13 (68%); and histopathologic change of small bowel mucosa, which was noted in 13 (68%). There was no correlation between clinical response to therapy and the development of toxicity, nor was there any between toxicity and histopathologic change in small bowel mucosa. Definite histopathologic change in each of the patients who responded to therapy was the only consistent relationship noted, although the appearance of such changes did not necessarily indicate that tumor response could be expected.
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v2
|
2018-04-03T05:02:17.791Z
|
1971-01-01T00:00:00.000Z
|
21587474
|
s2ag/train
|
Further studies on chromosome aberration production after whole-body irradiation in man.
SummaryThe dose–response curves for the production of chromosome aberrations in peripheral blood lymphocytes have been determined for radiation exposure both in vitro and in vivo. The in vitro response with 2 MeV x-rays follows approximately dose-squared kinetics over a range of 0–300 R. At low doses peripheral blood from an individual gives essentially the same results after irradiation in vivo and in vitro, but differences exist between individuals, though the response of blood cells from patients with cancer did not differ in this respect from controls. Extrapolation of in vivo data to doses higher than 50 R on the basis of the available in vitro data cannot yet be done with any certainty. More information is required on the shape of the in vivo dose–response curve, on the effect of the time after exposure at which the sample is taken and other possible factors that may cause variations.
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v2
|
2018-04-03T05:37:44.042Z
|
1971-01-01T00:00:00.000Z
|
43585824
|
s2ag/train
|
The effect of irradiation in high doses on parotid glands.
On radiation therapy of malignant tumours in the head and neck region, the salivary glands are often situated in the radiation field. Ten patients undergoing radiation therapy with high doses for tumours in the region of nasopharynx, lingua and bucca have been examined with respect to the function of the parotid glands. The glands received doses of 4 400-7 200 rad, and the function has been investigated by sialographic and sialometric methods. The sialograms show that one year or more after irradiation the parotid glands have a significantly smaller projected area than the non-irradiated glands. The irradiated glands had a sparser duct system than the non-irradiated ones. The sialometric examinations showed that all the irradiated glands stimulated with 1 % citric acid produced very little saliva. The secretion was in all cases remarkably lower than in a normal material, and in most cases only a few drops were collected during 10 min. In spite of a marked decrease in secretion at the end of the irradiatio...
|
v2
|
2019-03-11T13:13:00.702Z
|
1971-01-01T00:00:00.000Z
|
73027942
|
s2ag/train
|
The liver scan in patients with cancer: Histologic correlation
Liver scans, biopsies, and function studies were reviewed in 63 cancer patients and correlated with autopsy material to determine the value of the liver scan in such patients. The scan is abnormal in 96% of patients with autopsy‐confirmed hepatic disease, but the scan pattern is of little assistance in differentiating tumor from nontumor pathology. Liver function studies are equally nonspecific and even less sensitive than the scan. Percutaneous biopsy, while diagnostic when positive, is insensitive, showing false‐negative results in up to 40% of cases. The liver scan, as the most sensitive indicator of liver disease, may be most valuable when normal, reflecting a better prognosis and aiding in the determination of treatment. When the liver scan is abnormal, more specific tests must be employed. A method of approach is suggested.
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v2
|
2018-04-03T03:41:23.985Z
|
1971-01-21T00:00:00.000Z
|
7469658
|
s2ag/train
|
Smoking and cancer of the lower urinary tract.
Abstract Interviews were conducted with 470 patients with transitional or squamous-cell carcinoma of the lower urinary tract, more than 90 per cent of whom had a bladder tumor. An age-stratified and sex-stratified but otherwise random sample of 500 persons drawn from the population of the entire study area was also interviewed as a control. Among men, cigarette smokers have a relative risk of bladder cancer of 1.89 as compared with nonsmokers, and about 39 per cent of the cases are related to smoking. This amounts to 16.4 cases per year per 100,000 men 20 years of age and over. Among women 20 years of age and over, the comparable figures are 2.00, 29 per cent and 3.9 cases per year per 100,000. For both sexes risk is increased among those who smoked heavily and those who inhaled. None of the excess risk of bladder cancer associated with cigarette smoking is explained by any indirect association with occupational experience. No significant risk is associated with pipe or cigar smoking. The data also sugges...
|
v2
|
2017-08-16T20:03:56.226Z
|
1971-01-23T00:00:00.000Z
|
44536402
|
s2ag/train
|
Long-acting phenothiazines in schizophrenia.
hand for the study of other sorts of disease in the mass. The latest issue of the British Medical Bulletin' shows how diverse these researches have become. With Professor E. D. Acheson as scientific editor the B.M.B. provides a series of authoritative reviews of some of the more important work being carried on at present in the epidemiological study of non-communicable diseases. That this study is not simply one for specialists is evident from the fruitful discoveries that individuals have sometimes made from an initially limited range of observations. Examples in our time are the late Sir Norman Gregg's connexion of congenital defects in babies with outbreaks of rubella, Mr. D. P. Burkitt's identification of a type of lymphoma with a special geographical distribution, and Dr. W. Lenz's finding that babies with certain deformities were born more often to mothers who had taken thalidomide than to those who had not. The last is an example of another field of study that epidemiologists have entered in recent years-that is, the effects of drugs. For instance, the statistical techniques that epidemiologists developed have been exploited with subtlety to show the relationship between thromboembolism and the taking of different types of oral contraceptive. And the Committee on Safety of Drugs in Britain has established its Subcommittee on Adverse Reactions to provide, in effect, a permanent epidemiological watch over the actions of drugs in a much larger population than could come under the observation of only one or a few doctors. The importance of sending information, however apparently disconnected, to this subcommittee cannot be overemphasized if it is to fulfil its function of assessing the significance of reports and advising the medical profession. The necessity of keeping up the epidemiological study of drug action is clear enough from some further examples given in the B.M.B. by Professor Richard Doll of serious side effects. They include ileal obstruction from enteric-coated potassium chloride taken with a diuretic, death from excessive use of aerosols by sufferers from asthma, and hypertensive crises in patients on monoamine oxidase inhibitors who ate foods (especially cheese) containing tyramine. In all these cases perspicacious observers noted coincidences which, on further study, were found to conceal some kind of causal connexion. In the study of the effects of industrial products and their processes on health the epidemiological approach has been particularly rewarding, for it is often possible to say with some precision which workers in a factory or whole industry have been exposed to a particular agent and which have not. Notable contributions have thus been made to our knowledge of pneumoconiosis and asbestos cancer, to name two diseases discussed here by Dr. S. Rae and by Dr. J. C. Wagner and his colleagues. Other respiratory diseases are the subject of papers by Dr. J. R. T. Colley and by Professor D. D. Reid and Dr. C. M. Fletcher, and they complement the report issued by the Royal College of Physicians of London2 3 this month on that exceedingly potent cause of respiratory disease, tobacco smoking. This too has given rise to some of the classic epidemiological investigations into non communicable diseases, and incidentally presented in its sharpest form the question that every epidemiological study poses sooner or later: Does the correlation in this particular study mean causation? The evidence that tobacco smoking increases the likelihood of a person's contracting one of the diseases known to be associated with the practice is so great that the word "causation" is now unashamedly pronounced in this context. But that was hardly possible for some years after the first statistical papers appeared in 1950,4 5 and the authors of them long set an example in cautious interpretation that more impatient spirits sometimes found irksome. Ifthe correlation-causation duality is a troublesome problem at the heart of every epidemiological investigation, another pitfall lies in the investigator's path at its beginning. That is the accuracy of the observations by which the data are obtained. The data may be industriously gathered, precisely analysed, and cautiously interpreted, yet be based on faulty observations. Risk of this needs to be specially guarded against when doctors not specially trained in research collect data, whether in hospital or general practice, for analysis by another person, or when an investigator obtains his information from patients through the intermediary ofnon-medical interviewers. In the screening of substantial sections of the population many problems can arise, and in this issue of the B.M.B. Professors A. L. Cochrane and W. W. Holland discuss some of the ethical, scientific, and financial aspects of them. They rightly add that "the decision as to which conditions justify screening should also be based on an evaluation of the test used to detect them." Another side of that problem is to be seen in Dr. J. K. Wing's account of the psychoses and their distribution. He concludes that, though a number of community surveys appear to indicate that the functional psychoses are not equally distributed in all parts of the world, methodological difficulties have prevented any conclusive study of the matter. Unlike some of the more specialized issues of the B.M.B. this one touches on many branches of medicine and on general as well as specialist practice. Epidemiology is no more than the study of disease in the community as distinct from the individual patient, and no matter how much a doctor may be occupied in treating each of his patients as a separate person his understanding of the individual must be enhanced by his knowledge of that person as a typical or abnormal member of the community.
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v2
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2017-06-22T13:38:43.353Z
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1971-02-01T00:00:00.000Z
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40030213
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s2ag/train
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Serum level of erythropoietin in anemias associated with chronic infection, malignancy, and primary hematopoietic disease.
The serum level of erythropoietin was measured in 31 patients with anemia secondary to chronic infection or malignancy and compared with erythropoietin levels in 23 patients with iron-deficiency anemia and 14 patients with primary hematopoietic diseases. Erythropoietin levels varied directly with the degree of anemia in patients with iron deficiency or primary hematopoietic disorders. There was no correlation of erythropoietin and the degree of anemia in patients with chronic infection or malignancy and the erythropoietin levels were significantly lower than in patients with iron deficiency or primary hematopoietic disease and the same degree of anemia. A major factor in the anemia of chronic disorders is a decrease in levels of erythropoietin.
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v2
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2017-08-28T05:46:12.832Z
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1971-02-01T00:00:00.000Z
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36191645
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s2ag/train
|
A massive lipoma in a patient receiving chlorpropamide therapy.
Clinical and pathological report A 60-year-old Pakistani had been aware of a tumour of increasing size for about 16 years. Initially, the lump was very small and it had only slowly increased in size for several years. For about the last 5 years it grew rapidly to reach its present massive dimensions, approximating to the size of a Rugby football. The lump originated by a relatively narrow stalk from his upper back. It was freely mobile and its surface was ulcerated in parts, probably due to local pressure. Large veins were clearly visible in the overlying skin (Fig. 1). Some skin tethering was present and the tumour surface felt lobulated. Also for about 16 years, the patient had been thought to have diabetes mellitus. There was no clinical or laboratory evidence for this but he had been taking chlorpropamide, an oral hypoglycaemic agent, for several years-probably eight. His health was otherwise satisfactory. Chest radiography showed an immense posterior soft tissue swelling but no other abnormality (Fig. 2). A standard glucose tolerance curve was unequivocally normal after a few days without chlorpropamide (blood glucose 67 mg/100 ml, fasting, and then 102, 123, 91 and 72 mg/100 ml at I hr intervals). His protein bound iodine level was 5-7 ,ig/100 ml.
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v2
|
2018-04-03T00:41:37.747Z
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1971-02-01T00:00:00.000Z
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26306697
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s2ag/train
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Neoplastic argentaffin cells in gastric and intestinal carcinomas
Histochemical examination for argentaffin cells in 382 gastric and 81 intestinal carcinomas was carried out, and revealed that 3.1% of gastric and 2.5% of intestinal carcinomas contained argentaffin cells as an integral element of the tumor. Occurrence of these specific cells was predominantly encountered among diffuse carcinoma of the stomach. A hitherto undescribed case of diffuse carcinoma of the stomach containing numerous argentaffin cells is reported, and the term “diffuse argentaffinoma” is suggested. The findings obtained may provide the background for the possible presence of gastric cancer in patients who have a carcinoid syndrome.
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v2
|
2018-04-03T01:00:43.742Z
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1971-02-01T00:00:00.000Z
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27520479
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s2ag/train
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A cell line from a human salivary gland mixed tumor
A cell line called Nagoya‐78 has been established from a human salivary gland mixed tumor. The cytoplasm of the cells contain much glycogen but little acid polysaccharide and mucin. The ultrastructure of the cells exhibit epithelial characteristics with desmosomes, and no virus particles are present. The doubling time is around 24 hours. The cell line can be cultured as a suspension, but the growth rate is lower than that of stationary cultures. The chromosome constitution approximates trisomy with 5 marker chromosomes. The cells grow slowly in the cheek pouch of unconditioned hamsters.
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v2
|
2018-04-03T01:33:32.730Z
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1971-02-01T00:00:00.000Z
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19977784
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s2ag/train
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Nuclear pockets associated with the nucleolus in normal and neoplastic cells.
Cytoplasmic projections into the nucleus forming nuclear pockets have been observed in Ehrlich ascites tumor cells, chick embryo lens, human amelanotic malignant melanoma, human corneal epithelium from Fuchs' dystrophy, and raccoon spinal neurons. A significant proportion of these pockets were related structurally to the nucleolus. These configurations are believed to be related to enhancement of nucleolocytoplasmic interaction.
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v2
|
2018-04-03T01:50:39.290Z
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1971-02-01T00:00:00.000Z
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31240525
|
s2ag/train
|
Superselective arterial catheterization as a vehicle for delivering radioactive infarct particles to tumors.
Abstract Arterial infarct implantation to tumors is suggested as a logical extension of selective arterial perfusion of tumors with chemotherapeutic agents. The arterial bed of a tumor provides an arborized system which allows the distribution of infarct particles to various areas of the tumor, while the propensity of arteries to respond to infarction by means of spasm, as well as the resulting preferential flow to other areas, facilitates a geometric distribution of infarct sources. The author's experience in the treatment of 20 patients with hypernephroma and 12 patients with advanced pelvic neoplasms is described.
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v2
|
2018-04-03T02:47:41.177Z
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1971-02-01T00:00:00.000Z
|
35000566
|
s2ag/train
|
Bone metastases in cancer of the esophagus.
1. Carcinoma of the esophagus metastasized to the skeletal system late in the course of the disease in 5.2 per cent of 1,909 patients seen at Memorial Cancer Center.2. Radiation therapy in doses of 1,500 to 2,000 r to areas of pain or impending fracture was beneficial in 50 per cent of the patients treated, but unfortunately did not prolong their survival.
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v2
|
2018-04-03T03:16:45.168Z
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1971-02-08T00:00:00.000Z
|
1559726
|
s2ag/train
|
The place of implantation in tongue and floor of mouth cancer.
Since 1959, we have treated cancers of the mobile tongue and floor of the mouth by interstitial therapy with iridium Ir 192 (afterloading technique). 17-19 Among more than 400 cancers of this anatomic region treated either by interstitial iridium Ir 192 pins (epingles) afterloaded through stainless steel guides or continuous iridium Ir 192 wire afterloaded into nylon tubing, we have extracted 153 cases representing all new, untreated lesions of minimal or moderate extent, which have been referred to our clinic at the Institut Gustave Roussy between January 1959 and June 1969; the rest of the 400 cases had recurred or advanced disease. We have at our disposal, then, a period of observation for these patients from a minimum of six months to a maximum of 10.5 years. These lesions have a maximum diameter of less than 4 cm. Here is the distribution of these cases as a function of their
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v2
|
2014-10-01T00:00:00.000Z
|
1971-03-01T00:00:00.000Z
|
9744757
|
s2orc/train
|
Growth of metastases from P-388 sarcoma in the rat followig whole body irradiation.
The growth of an allogeneic rapidly growing and metastasizing sarcoma (P-388) in the rat is described. Quantitative and kinetic data are provided concerning the growth of individual metastases produced in three principal regional lymph node drainage groups, and are compared with growth of the primary tumour of origin in muscle; the incidence of pulmonary metastases is also given. The effects on growth of metastases and primaries produced by sublethal whole body irradiation (WBI) before inoculations of 10-108 tumour cells are described. Growth of P-388 sarcoma in unirradiated recipients (ED50 ≃ 5 × 103 cells) obeyed the linear growth law proposed by the Mayneord model for tumour growth, but in irradiated recipients (ED50 < 10 cells) early growth of primaries and metastases approximated more closely to an exponential rate of growth. The ratio M/P of weight of metastases (M) to weight of primary tumour of origin (P) increased at a linear rate with age (t) of tumour, and gave the same slope namely, 0·029 for pelvic node metastases) in unirradiated rats inoculated with a large (106-107) number of cells as in irradiated rats. The slope was decreased to 0·014 for pelvic node metastases in unirradiated rats challenged with fewer (104) cells but not in irradiated recipients. It is postulated that the effects of WBI on growth of metastases are confined to causing a suppression of immunity, and that WBI does not affect tumour spread significantly through other mechanisms. In immunologically competent rats the phenomena of sequestrated progressive growth of isolated metastases in lymph nodes and of a chronic nonprogressive enlargement of nodes in which persistent tumour growth and destruction occurred side by side are described, and effects on prognoses and clinical behaviour, are discussed. The P-388 tumour is considered of value in quantitative and kinetic experimental studies of metastases, and particularly those in which the role of immunity needs to be assessed and measured to avoid confusion with other factors or agents which might affect the spread and growth of metastases.
obeyed the linear growth law proposed by the Mayneord model for tumour growth, but in irradiated recipients (ED50 <10 cells) early growth of primaries and metastases approximated more closely to an exponential rate of growth.
The ratio M/P of weight of metastases (M) to weight of primary tumour of origin (P) increased at a linear rate with age (t) of tumour, and gave the same slope namely, 0-029 for pelvic node metastases) in unirradiated rats inoculated with a large (106-107) number of cells as in irradiated rats. The slope was decreased to 0-014 for pelvic node metastases in unirradiated rats challenged with fewer(104) cells but not in irradiated recipients. It is postulated that the effects of WBI on growth of metastases are confined to causing a suppression of immunity, and that WBI does not affect tumour spread significantly through other mechanisms.
In immunologically competent rats the phenomena of sequestrated progressive growth of isolated metastases in lymph nodes and of a chronic nonprogressive enlargement of nodes in which persistent tumour growth and destruction occurred side by side are described, and effects on prognoses and clinical behaviour, are discussed.
The P-388 tumour is considered of value in quantitative and kinetic experimental studies of metastases, and particularly those in which the role of immunity needs to be assessed and measured to avoid confusion with other factors or agents which might affect the spread and growth of metastases.
RELATrVELY few transplantable solid tumours in animals metastasize regularly from the primary site of inoculation and allow comparative and kinetic studies of growth of metastases to be made. This paper documents quantitative data concerning the rates of growth of solid metastases in lymph nodes and lungs from a rapidly growing allogeneic sarcoma P-388 in the rat, alid compares growth in unirradiated (immunologically intact) recipients with gro-wth in rats given sublethal whole body irradiation before tumour inoculations to suppress the immunological reactions to tumour growth.
Tumour
The P-388 sarcoma used in these experiments was a nitrogen-mustarcl resistant strain of Yoshida ascites sarcoma, which was kindly provided by Dr. T. A. Connors, Chester Beatty Institute, Lonclon.
The original Yoshida sarcoma could be grown either as an ascitic or solid tumour and was considered to be of reticulo-endothelial derivation (Yoshicla, 1949(Yoshicla, , 1952. The P-388 variant behaves simflarly and resembles an anaplastic reticulosis in its mode of growth and spread. The tumour metastasizes freely and rapidly along associated lymphatic pathways to form metastatic deposits in regional lymph nodes. At a later stage centripetal lymphatic spread produces more widespread node metastases. Tumour cells which enter the main lymphatic ducts are carried into the venous circulation, traverse the right heart and arrest in the lungs to produce discrete pulmonary metastases. Larger solid deposits of tumour-both at the primary site and metastases-are characterized by an outer narrow rapidly proliferating and invasive zone, an intermecliate intensely haemorrhagic zone consisting of both viable and necrotic foci of tumour separated by lakes of stagnant blood and haemorrhage, and a central zone of necrotic tumour which predominates in larger older tumours. Thus in structure the P-388 tumour conforms with the model system of tumour growth proposed by Mayneord (1932). Histological and micro-angiographic studies have shown that this tumour fails to stimulate significant growth of new blood vessels (angiogenesis) and other tissues which constitute a vascular stroma required to support its continued growth and to prevent necrosis (to be published); viable prohferating tumour primarily utilizes the capillary beds of the invaded tissues for its nutrition and metabolism. Intratumoral haemorrhage causes growing solid deposits to be blood-red in colour and this facilitates the enumeration of pulmonary metastases in freshly excised lungs for quantitative purposes.
Passage and inoculation
The P-388 tumour was passaged every 4.4 days in female Caworth Farm (Wistar) rats of a specific pathogen free strain by intraperitoneal inoculation of 1-2 x 106 P-388 cells. Suitably diluted tumour ascites fluid was counted in a Coulter (model A) electronic cell counter. A parallel differential count of tumour cells and erythrocytes was made on each donor sample to correct for contamination with blood. In samples of 4=5-day-old ascites fluid used for inoculation, < 5 % of erythrocytes and < 1% of leucocytes and macrophages were usuaRy present and tests for cell viabihty based on a dye-exclusion technique with 0-1% nigrosin showed that < 0-I% tumour cells appeared non-viable. P-388 ascites fluid was diluted with ice cold Tyrode's buffer (pH 7 -6), and 0-I ml. containing the required number of cells was inoculated intramuscularly into the distal third of the gastrocnemius muscle above the ankle joint of the rat. A group of 6-8 rats were used for each point in constructing tumour growth curves.
Tumour inoculations made into the leg muscle of rats gave rise to diffuse thickenings which expanded the leg into a pyramidal shape. The using of calipers to determine mean dimensions was found both tedious and inaccurate. Consequently growth of tumour in the leg was scored at 1-2 day intervals in individual rats which were randomized, using a semi-quantitative index of the size (0-6) graded as: no tumour palpable (0); slight thickening (1); spindle shaped thickening of distal of leg muscle but no visible deformity (2); whole calf thickened, with visible enlargement and encroaching on pophteal fossa (3); large triangular shaped tumefaction of whole calf and thigh muscle causing flexion deformity (4); and whole hindquarter involved bv larLye tumour with oedema of foot (6).
To weigh primary tumour and metastases, the rat was killed by an overdose of pentobarbital Na and dissected. The ipsilateral (inoculated side) and contralateral popliteal nodes were removed through longitudinal incisions over each fossa and weighed. Then both hind limbs were amputated at the same level and weighed separately to determine weight of the primary tumour by subtraction. To calculate the error involved in excising and weighing a fimb, the right hind limb was excised in groups of six normal rats, weighing 100-120 g., and the mean weight of limb per unit body weight determined. The latter was found to be associated with a standard deviation of ± 5%, and it was calculated that a difference in weight of not less than 0-6 g. between the intact and tumour-bearing legs was required to be significant at the 0-05 level. Next, the abdomino-thoracie skin was incised longitudinally, widely elevated and retracted to expose inguinal, axillary and submandibular nodes on both sides. Any macroscopic evidence of metastases was recorded, and in some experiments the inguinal nodes were removed and weighed. The abdomen was opened, and the vagina and rectum divided as low as possible; the uterus and adnexa, and rectum were stripped to expose the central groups of lower and upper abdominal nodes which were removed and weighed. The lower abdominal nodes (referred to as the " pelvic " group) were defined as all nodes contained within the bifurcation of the aorta (presacral and iliac nodes) together with all paraortic nodes distal to the renal vessels, but excluding nodes contained within the leaves of the mesentery and mesocolon. The " upper abdominal node " group was constituted by all retroperitoneal paraortic and retroaortic nodes situated between the origin of the renal vessels and the crura of the diaphragm, i.e. the nodes related to the coeliac axis and the origin of the thoracic duct, including the retroaortic node which is partly hidden by the left crus of the diaphragm. Lymphatic dissemination of the tumour from the primary inoculation site in the leg involved early spread to ipsilateral popliteal (crural (CN)) and pelvic nodes, followed by subsequent spread to upper abdominal nodes, inguinal and mesenteric nodes. Once upper abdominal node metastases were present, and often earlier, a more widespread dissemination of tumour to more outlying lymph node groups (mediastinal and thymic groups, axillary and even submandibular lymph nodes) was seen. In animals with advanced tumours, and particularly after whole body irradiation, the contralateral inguinal nodes and contra-lateral popliteal nodes became macroscopically involved and enlarged. The number of metastases present on the pleural surface-s of both lungs were counted when their number clid not exceed 200. Iin lungs with 200 or more pleural metastases it was not possible to make sufficiently reliable counts, and these rats were scored arbitrarily as having 200 (maximum) metastases. In most experiments the spleen and thymus were removed and weighed, and individual changes in body weight of rats were also recorded.
The weights of the primary tumour in the leg (P) ipsilateral popliteal nodes (CN), pelvic nodes (PN) and upper abdominal nodes (UAN), respectivelv were used to construct corresponding growth curves. The incidence of pulmonary metastases largely represented the " final spill-over " of tumour metastasis in the lymphatic system into the circulation. The corresponding weights of primary tumour (P) and metastasis (M) were used to analyse the rates of production of metastases and relative rates of growth by determining changes in the ratio M/P with time (T) after inoculation, or by altering the number (N) of tumour cells inoculated and weighing the tumours at the same POSt-iDoculation time. In uninoculated rats the normal weights of pelvic, upper abdominal and crural lvm-ph nodes were < 0-04) < 0-03, and < 0-01 g. respectively in unirradiated rats and < 0-02, < 0-01 and < 0-005 g. respectively after 570 rad. WBI. To calculate M/P ratios, the maxiMum weights of normal lymph nodes were subtracted from weights of corresponding involved nodes in the inoculated rat to obtairl more accurate values for weight of tumour metastases. In unirradiated rats reactive enlargement of nodes must also be taken into account. It was found that the injection on three successive days of 1-5 x 107 P-388 cells subjected to a high dose (4-6 krad.) X-radiation in vitro to prevent their growth (HR cells) did not cause the regional nodes to increase to more than double their normal weight. Nodes weighing more than 0-08 (PN), 0-06 (UAN) and 0-02 (CN) g. respectivelyiDunirradiated rats, or more than 0-02 (PN), 0-01 (UAN) and 0-01 (CN) g. in irradiated recipients invariably showed macroscopic and microscopic evidence of tumour growth, and these values were taken to represent the upper limits of normality even in the presence of reactive (hyperplastic) changes.
Irradiation techni q ues
A twin-headed therapeutic Cobalt 60 unit, kindly made available by Dr. 1. Churchill-Davidson, was used to irradiate uniformly a box containing 10-12 rats placed midv.ay between the two sources. The mean dose rate in tissue from the two sources (totalling 8273 Ci) was 157 rad. min-'. The rats received a single whole body exposure of 570 rad. to suppress immunological functions, usually 1-4 hours before inoculation of P-388 cells, but in some experiments 4-16 hours elapsed between irradiation and inoculation. Tw'm opposed X-ray beams operated at 250 kv 15MAwith added filtration to give a HVL I -0 mm. Cu were used to irradiate tumour cells in vitro and also to locally irradiate the limb tumour, the body of the anaesthetized animal being shielded between 2 mm. thick lead plates containing appropriate cutouts to expose the tumour bearing hmb tissues only. Tumour " take " and ED50 The number of P-388 cells required to produce palpable (Grade 1-2) tumours at the site of primary inoculation in muscle within 4 weeks after inoculation in 50% of rats was taken to represent the ED.50 dose.
Double leg inoculations
In certain experiments the host's immunological capacity to react to P-388 cells was assessed in terms of the growth of a second intramuscular challenge of the tumour to the contralateral leg (termed second challenge), given at intervals after the first challenge. Immunt'zation of rats against P-388 cells In some experiments, active immunization involved the use of P-388 cells sterilized by heavy irradiation (HR) or by incubation at 37' C. for 30 minutes with a sulphydryl inhibitor, sodium iodoacetate (NaIOA) or N-ethylmaleimide (NEM) as described by Apffel et al. (1966). It was found that the P-388 tumour cells were unusually resistant to killing by these reagents; incubation in concentrations of 10-2m NaIOA and 10-1 m NEM respectively were required to prevent growth of 106-101 tumour cells in rats which had not received whole body irradiation. It was also found that P-388 cells stored frozen at 70' C. in the presence of glycerol or dimethylsulphoxide, and irradiated with 4000-6000 rads after thawing, were much less effective for immunizing of rats than freshly removed and irradiated cells; NalOA also proved more efficacious than NEM in this respect. Consequently, to increase immunity irradiated non-frozen freshly removed cells, or freshly removed cells incubated with 10-2m NalOA or 10-1 m NEM, were used. Rats received 1-4 x 107 inactivated P-388 cells subcutaneously twice weekly for 3 weeks, and were challenged intramuscularly a week later with 105 intact P-388 cells. If the latter failed to " take " and grow, the rats were regarded as hyperimmune and a further 106-107 viable cells were inoculated and their growth compared with the growth in unimmunized rats.
ED50values (tumour take)
The ED50 value for intramuscular inoculations was approximately 5 X 103 tumour cells in unirradiated recipients and < 10 cells in rats pre-irradiated with 570 rad. WBI. Repeated assays performed over the preceding year gave ED50 values not significantly different from these values. In unirradiated recipients 102 cells rarely " took " to produce palpable tumour or metastases; 105 cells invariably produced local growth of tumour, but metastases often failed to show up macroscopically, whilst 106-107 cells produced metastases which grew and killed most rats within 3-6 weeks.
For subcutaneous inoculations made into the tissues of the neck overlying the salit,ary glands, ED50 values were similar to those obtained for the intramuscular route, but values were higher for subcutaneous inoculations into the foot and tail. Immunization produced by growth of tumour In rats challenged with the tumour in one leg, which was either allowed to grow for varying times or treated with a local single dose of 1600 rad. X-rays to arrest its growth, a second challenge withJ06P-388 cells into the contralateral leg grew less well depending on the interval elapsing between challenges. Fig. I shows growth of second challenges (106cells) in 72 rats given 0-60 days after a primary challenge withJ07 cells. A progressive increase in immunity occurred during growth of the first challenge, even if tumour growth was prevented or reduced by local irradiation administered before the second challenge was given. Fifty days after rats were challenged withJ07 cells, and the resulting 7-14-day-old tumours had been irradiated to inhibit their growth so as to allow the rats to survive, a second challenge of 106 cells failed to take and grow in the opposite leg. Curves of tumour growth (unirradiated hosts) Growth curves for the primary leg tumour (Pr) at site of intramuscular inoculation and for lymph node metastases (PN, UAN, CN) in unirradiated female rats inoculated withJ07 or 104 P-388 cells are shown in Fig. 2 and 3 respectively. Similar curvilinear, relationships were obtained for Pr and its metastases in lymph nodes. Tumour growth rates characteristically decreased as tumours enlarged, i.e. the doubling time (T) for tumour mass increased (vide infra). Initially weight of Pr increased very rapidly (T < 24 hours) as did weight of lymph nodes infiltrated with tumour in rats given a large inoculum (107 cells). A smaller inoculum(104 cells) produced a more rapid decline in growth rate of Pr than larger inocula and an even more marked reduction in the rate of growth of lymph node metastases. The (7) ( x x ) and in rats 2 hours after wholebody irradiation ( x ----x ) are show-n for comparative purposes. Measurement of size of tumour has been based o'n the index (Grades 0-6), as described under Methods. Data is for ten groups, each composed of 6-9 rats. enlarged lymph nodes produced by smaller inocula showed early microscopic evidence of tumour cell proliferation with the presence of tumour cell clones, but these metastases usually failed to progress and survive; 2-3 weeks after inoculation the popliteal and abdominal nodes in most rats remained either moderately enlarged or had regressed, despite further gro*th of primary (vide infra). However, in a proportion of animals tumour continued to grow in a single node or node group after growth in other nodes had ceased and often completely regressed. In such animals a large solitary tumour metastasis had not infrequently grown to 50 g. or more i pelvic (PN), upper abdominal (UAN) and ipsilateral crural (CN) lymph nodes produced by the intramuscular inoculation of 107 tumour cells into the right gastrocnemius muscle of unirradisted female rats. Each point represents mean value for a group of 6 rats; each standard error shown as a vertical line where it exceeds the size of symbol. Interrupted lines show correction of curves for inetastases in nodes after subtracting norinal node weights. Closed symbols are used for values obtained in 9 immunized rats pretreated with heavily irradiated (HR) tumour cells or cells incubated in 10-lm NEM in which 104 intact cells subsequently failed to take; these rats were killed 7 days after a further intramuscular challenge with 2 X_ 107 intact P-388 cells. 0 0 V Growth in 75 g. rats.
Growth in 130 g. rats.
Growth in 1'90 g. rats. 0 A N V Growth in 9 immunized rats (see above). I I 193 GROWTH OF METASTASES FOLLOWING IRRADIATION weight, and caused local complications such as intestinal or biliary obstruction, ascites (usually non-malignant) etc., resulting in death. Upper abdominal and mesenteric groups of nodes, including deposits of tumour in Peyer's patches, appeared most prone to this " isolated " development of tumour. These animals frequently remained in good health and nutrition and gained weight for several months in the absence of such complications despite progressive locahzed growth of the solitary metastasis. Other apparently normal or moderately enlarged lymph nodes present in the rat and examined histologically usually showed microscopic foci of tumour growth at various stages of active proliferation or degeneration.
Thus, large primary inocula (106-107 cells) tend to grow progressively and produce centripetal spread of tumour and progressive anaemia and malnutrition which terminate in early death. SmaHer inocula (104-105-cells) usually produce progressively growing and eventually large primaries, eai.ly, but limited growth of lym-ph node metastases which subsequently regress and 'thereby prolong survival or give rise to the condition of " solitary " progressively growing metastases as described above. Yet smaller inocula ( < 104 cells) usually fail to take primarily and establish metastases in unirradiated (immunologicaRy intact) hosts. (0); pelvic node weights associated with tumour " take " and growth produced by challenges of 5 x 105-106 cells (,&); 105 Cells (M) and 104 CellS (A) respectively. Individual points for 107 inocula not shown. Each point represents mean values for a group of 3-12 rats. The symbols & show mean weights of pelvic nodes in rats inoculated with 104-1011 cells, in which no priinary tumour developed, growth of the primary was arrested at an early stage (< 14 days) or the primary had regressed spontaneously. Included in this category axe PN node weights of rats inununized with inactivated P-388 cells and subsequently challenged with 106-107 intact tumour cells., which either grew or failed to " take " at the site of inoculation.
16 24 32 40
Partial active immunization of rats sterilized with P-388 cells, i.e. heavily irradiated (HR) cells or cells incubated with sulphydryl inhibitors, caused a reduction in growth rate of both primary tumours and metastases produced by a large (107 cell) inoculum (Fig. 2) and a corresponding increase in the ED50 dose for primary take of tumour. Intensive immunization with HR cells, reinforced by challenges with increasing numbers of intact tumour cells, made most rats resistant to a further challengeof 106-107P-388 cells. Fig. 4 summarizes data from various experiments as curves of growth for pelvic lymph node metastases (corrected for normal weight of nodes) caused by a range of P-388 cell inocula, and includes growth of metastases in nodes of rats in which arrest of Pr growth had occurred spontaneously. This occurred in unimmunized rats challenged witb smaller inocula and in partially immunized rats challenged with larger inocula. Data are also shown for rats in which a progressively growing Pr had produced generalized growth of metastases but at an inadequate rate to cause death within the first 3-4 weeks; these nodes enlarged rapidly initially but thereafter decreased in size and gave rise to a state of residual non-progressive (" steady state ") enlargement; the nodes remained 10-20 fold heavier than normal for prolonged periods and on microscopic examination showed the presence of tumour cell infiltrates and clones of various sizes and in various phases of proliferation and degeneration. In rats in primary tumour and metastases produced by intramuscular inoculations of 5 x 106 P-388 cells in unirradiated rats and I x 106 P-388 cells in rats exposed to 570 rad. whole body irradiation 2 hours before challenge with tumour. Abbreviations as in Fig. 3, 4; 6 rats per point. which primary growth was spontaneously arrested, node metastases usually regressed also, and nodes were restored to near-normal size (spontaneous cure of metastasis), except when isolated metastases continued to grow, often to massive size, as described above.
Growth of tumour after whole body irradiation (WBI) Growth curves for intramuscular inocula and regional lymph node metastases in rats exposed to a single dose of 570 rad. (6 OCO y-rays) whole body irradiation 24 hours precediDg inoculations are shown in Fig. 5 and 6 and are compared with growth in unirradiated recipierits. For the first week, the growth curves for Pr ,O % 3. Measurements on day 14. 0 4 t Measurements on day 16. and metastases in unirradiated rats were essentially similar in form to those obtained with larger inocula in unirradiated recipients, but due to more rapid growth, somewhat larger tumours resulted in irradiated recipients. Beyond 7 days the rate of growth of Pr decreased at a disproportionate rate in irradiated rats and Pr often decreased in weight when the irradiated rats became terminal and suffered from severe anaemia, loss of weight and widespread growth of pulmonary metastases (vide infra). The latter was a principal cause of death during the second week after inoculations of 104 or more cells in rats given WBI. The terminal decrease in growth rate and weight of larger tumours in the irradiated host rat is attributed t'o nutritional factors and not to the recovery of an immune or some other host defence mechanism, since fewer (102-103) cells allowed to grow for longer produced equally large tumours (Fig. 6), and since no comparable decrease in growth rate of lymph metastases (small by comparison with the corresponding Pr) occurred in irradiated rats in which concomitant decreases in growth rate of the larger Pr had taken place. The most striking difference in tumour growth between irradiated and unirradiated recipients was the rate of growth of metastasesfollowing the inoculation of fewer(IC4) cells (Fig. 6); irradiation caused lymph node metastases to appear and grow much more rapidly and at rates comparable to the primary. This is attributed to the arrest of immunological reactions after WBI and the associated decrease in the ED50value) which allows growth of a very few newly deposited cells to occur. The curves for enlargement of lymph nodes in unirradiated rats cross those in irradiated animals (Fig. 6). This is principally due to atrophy of normal node tissues produced by WBI but also to the contribution made by hyperplasia to weight of nodes in unirradiated rats. The latter is negligible after WBI since the inoculation of as many as 108HR tumour cells into the muscle of irradiated rats caused no significant increases in weight of crural and pelvic nodes.
The dose (570 rad.) of WBI used in these experiments allowed > 90% of unchallenged rats to survive beyond 30 days; during the first 7 days weight of the spleen and thymus decreased by > 50% and > 80% respectively, and these losses in organ weight were not reversed during the first 10 days, similar delays being associated with recovery in changes of body weight and anaemia and leucopenia due to WBI. These findings together with data based on ED,50 determinations and tumour growth rates suggest that immunological defences remained severely attenuated for at least a week after WBI.
Tumour doubling times
The doubling time for tumour mass (T) was plotted as a function of weight of tumour (W). In unirradiated recipients inoculated intramuscularly withJ06 cells T was linearly related to W by the relationship, logT = mlog W + c where m and c are constants. Data for smaller tumours produced by subcutaneous growthof 106Yoshida sarcoma cells in the flank of rats reported by Hiraiet al.
(1968) and our ow-n data for larger P-388 tumours from intramuscular inoculations, were fitted by the same linear relationship (Fig. 7). The slope for growthof 107 cells inoculated into muscle was of the same order of magnitude as for 106cells, but 104 ceRs gave a much steeper increase in T with growth of tumour. This is attri-buted to the more efficient destruction of tumour by immune reactions in an animal challenged with a small inoculum, which takes longer to grow to a tumour of given size, and thereby allows a higher level of immunity to be achieved. Measurements of tumour doubling times after WBI, were necessarily restricted to smaller inocula since larger inocula grew and produced extensive metastases, at an early stage, resulting in nutritional decline and early death of rats. Fig. 7 shows changes in T for growth of Pr and PN metastases produced by 5 x 103cells in both unirradiated and irradiated recipients, in an experiment using doinor cells from a single rat. After WBI Pr and PN both grew at exponential rates (i.e. T constant) until the primary tumour weighed , 0-5 g. when T (Pr) increased but the metastases (PN, and also UAN and CN) continued to grow at exponential rates while their weights were less than that of the Pr (i.e. < 0-5 g.). In unirradiated rats T (PN) increased more rapidly than T (Pr). This may be due to more efficient immunological destruction of tumour cells in the nodes per se, but since immunization due to growth of tumour in the rat is time dependent (Fig. 1, vide supra) and can cope more efficiently with fewer tumour cells, these factors may also account in part for this differeDee. However, it was found that when T was expressed as a function of time after inoculation (tumour age t) that T (metastasis) increased more rapidly than T (primary). Thus T for both Pr and PN metastases increased at approximately linear rates with time (t) after inoculation of tumour cells according to T =kit+k2 where ki and k2are constants-a relationship also fitted by the data of Hirai et al. (1968) for primary tumours. For 5 x 103 cells inoculated into unirracliated rats values of k, were 0-55 (primary) ancl 1-65 (PN metastases); corresponding values for m (T expressed as a function of W) were 0-91 (primary) and 1-65 (PN metastases). Primary and metastasis growth relationships The ratio (M/P) for weight of a lymph node metastasis, corrected for normal tissue weight (M), to weight of the primary tumour of origin (P) was calculated for each rat and plotted as a function of age of tumour, for growth ot tumour in unirradiated and irradiated recipients M/P increased at a linear rate (Fig. 8). The rate was somewhat higher for metastases in the more proximally situated pelvic nodes-a difference possibly due to redistributions in flow of lymph and tumour cells produced by progressive nodal involvement. The finding that the rate of increase in M/P with age of primary tumour was less for a small inoculum(104cells) than for large inocula(106-107cells) in unirradiated recipients, but not in irradiated recipients, is of particular significance. It is considered that in this anogeneic system immunity destroys smaller tumour deposits of more recent origin more effectively than larger ones, and thereby limits the development and growth of metastases to a greater extent than growth of the primary tumour of origin. After WBI, slopes for M/P corresponding to PN and UAN were not affected by change in the number of cells inoculated over the rangeJO2-106cells. In Fig. 9 PN ratios have been pooled for 102--106 cells inoculated in irradiated rats and for 106-107 cells in unirradiated rats respectively. The two sets of data for irradiated and uiiirradiated recipients have been fitted by linear rela'tionships with the same slope, 0-029 (PN) and 0-017 (UAN) respectively. The rate of increase in the ratio M/P with age of tumour provides a useful quantitative approach to the study of kinetic aspects of 'Metastatic dissemination and would seem valuable for determining the effects of physical, chemical and biolo ical. treatments, specifically concern-9 ed with the control of such spread. Changes are produced by age and size of tumour in the contents of blood, oedema and necrosis and this affects the interpretation of changes in M/P-particularly early after inoculation when disparity in size between Pr and M is greatest and the onset of haemorrhage and oedema cause greater increases in weight of the more advanced primary tumour. In rats sacrificed 7 days after inoculating 1OZ-2 x 107cells, tumour weights (Pr and PN, UAN and CN metastases) were plotted on a log-log scale as a function of the number (N) of cells inoculated, for unirradiated and irradiated recipients respectively (Fig. 10). After initial slow increases in tumour weights, the relation-B. NO X-RAY A. WB/ 57o r6d. -Relationship between number of tumour cells inoculated intramuscularly and weight of primary tumour, lymph node metastases and number of lung metastases in (A) irradiatecl and (B) unirradiated recipient rats, killed 7 days after inoculation. Values for lung metastases enumerated on pleural surfaces (200 the maximum number scored) are shown for individual rats. Each point for mean tumour weight based on 6 rats; each standard error of mean (vertical line on symbol) shown for group A measurements only. 16 ships became linear, beyond " threshold " values of N -103 (irradiated) and N -105 (unirradiated recipieDts). The slopes of the linear regions for Pr and its metastases in immunologically suppressed and intact hosts, were calculated and found to approximate to a common value of 0-308. The difference in N of 2-3 log values between irradiated and unirradiated recipients for the onset of linear increases in tumour weight, corresponds to the difference in ED50values. Associated changes in the ratio M/P (7 days), expressed as a function of size of inoculum (N), were obtained in young female recipient rats (90-1 00 g. body weight) using tumour cells harvested froni a single donor rat (Fig. I 1). irradiated (closed symbols) recipients. Data shown for changes in body weight and weights of spleen and thymus, are confined to 90-100 g. rats which were killed 8 days after inoculation. Data for M/P pooled from a series of experiments on rats varying more widely in age; most were killed after 7 days but some (given smaller inocula) after 8 days.
challenge dose (, 107 cells) was required to raise the values of M/P for PN and UAN metastases in unirradiated recipients to equal those in irradiated recipients. This represeDtS the threshold in cell number required to initiate growth in this tumour host system against which immunological defences mounted by the host against spread of tumour to the nodes becomes insignificant in the control of such spread or in reducing the rates of growth of tumour at the primary site and in related nodes.
Metastase8 to lung8 and other organ8 Lung&-Most rats inoculated with 104 or more P-388 cells developed multiple mac.ro'scopic pulmonary metastases. In lungs with 100 or more enumerated surface nodules lung weights were increased and as much as threeto four-fold heavier than normal in terminal rats. 2, 2, 2, 57 7 + 6 > 200 (6 rats) Abbreviation8: Number of P-388 cells inoculated N, time (days) after inoculation T, whole body irradiation WBI given 2-24 hours preceding inoculation (+) or omitted (-); number of rats which developed pulmonary metastases I in each group consisting of 6 rats; number of metastases scored in lungs of each rat on macroscopic examination of freshly excised lungs or of lungs fixed in Bouin's fluid PM. Fig. 10 show the number of pleural metastases enumerated in lungs of uiiirradiated and irradiated rats inoculated with 102-107 P-388 cells. The incidence rose with the number of cells inoculated and with time after inoculation and was much higher after WBI. Both unirradiated and irradiated rats with pulmonary metastases, showed the presence of tumour cells in ventricular blood and in irradiated rats with massive pulmonary involvement, tumour cells were often the commonest nucleated cell present. Pulmonary metastases were absent or few in number in rats killed with early abdominal lymph node metastases and only appeared in large numbers of rather uniform size after more widespread metastases in lymph nodes had occurred and irrespective of size attained by the primary tumour. Fig. 10 shows that whole body irradiation reduced the number of inoculated cells required to produce an arbitrarily selected mean incidence of 50 pulmonary metastases in rats by approximately 2-5 log values-a difference similar to that for ED50 values in irradiated and unirradiated rats. Approximately 106 cells in unirradiated, and 103.__104 cells in irradiated rats induced the same number of pulmonary metastases. This suggests that irradiation causes a similar degree of immunological attenuation in the lungs as in other tissues (primary site and lym'ph nodes), and that the incidence of lung metastases simply represents the degree of cc spill over " of tumour from the lymphatic system into the circulation and lungs.
Heart and kidneylo.-Rats with advanced lymph node and lung metastases, fiequently showed growing metastases in the myocardium, particularly in ventricular musculature. Advanced upper abdominal lymph node metastases had frequently invaded adjacent kidneys and other organs by direct infiltration. In rats terminal with widespread pulmonary metastases, the kidneys (and other organs) also frequently showed multiple small subcapsular metastases similar to those described for lungs, and which appeared to have arisen by exfoliation from lung deposits and haematogenous dissemination.
Spleen ana thymus.-An example of the changes in weight of spleen and thymus in unirradiated and irradiated recipients is shown in Fig. I 1. Unirradiated recipients inoculated with 107 tumour cells developed splenomegaly (, 15% increase in weight) accompanied by decrease (, 40%) in w-eight of thvmus, and reduction (, 30%) in the rate of growth of the rat during the first 7-10 days. WBI (570 rad.) caused , 50% decrease in weights of spleen and thymus respectively and body growth was decreased by , 25%. Wben rats, after WBI, were inoculated with P-3S8 cells bodvLyrowth was markedly affected, and inoculaof 107 cells caused rats to lose weight at > I g. per day. Irradiated rats showed the same pattern of splenic enlargement and thymic atrophy due to tumour growth as unirradiated rats, the changes being superimposed on the atrophy of these tissues produced by WBI itself (Fig. II). The cause for these opposite changes in spleen and thynius weight is not clear. Thymus atrophy may be due to stress, aside from irradiation damage, and seems to parallel changes in body weight. Increases in spleen weight appears largely due to growth of tumour in this organ, being proportional to the number of cells inoculated and occurring more rapidly in irradiated rats; microseopicallv, the spleens showed discrete solid foci of tumour cell growth present mainly in wbite pulp. However, whether tumour growth accounts entirely for the changes in spleen weight has not been determined.
DISCUSSION
Relatively few allogeneic or syngeneic transplantable tumours are available for quantitative experimental investigatioins of metastatic spread (Kim, 1970) and to the role played by immunological reactions in growth of metastases. Although several experimental tumours produce metastases these may not develop in a particular organ with sufficient regularity to study the kinetic relationships between their growth and that of the primary tumour of origin in the same animal. P-388 sarcoma, an allogeneic, rapidly growing tumour host system in the rat, was chosen principally to investigate these aspects, since it could be grown as a solid tumour which metastasized along lymphatic pathways to lymph nodes and lungs, and the recipient rat showed immunological resistance to tumour growth whicb could either be suppressed or increased by suitable treatment of recipients before challenge with the tumour. Growth of the tumour as an ascites for passaging also facilitated accurate enumeration of cells for inoculations and assays.
By weighing the primary tumour and individual lymph node metastases associated with its lymphatic spread in animals killed at various times after inoculation with a known number of tumour cells, growth curves were obtained for primary and metastases and compared. The enumeration of lung metastases and increases in lung weight in such animals provided further measures of metastatic behaviour. The rapid rate of growth of P-388 sarcoma and its metastases also allowed suitable measurements of growth to be made under conditions of immunological suppression by sub-lethal whole body irradiation of the host before significant immunological recovery took place and thereby provided an immunological situation more closely allied to a sy-ngeneic or autochthonous tumour-host system.
Certain characteristics of P-388 growth in tissues, shared by other experimental tumours, present some difficulties to quantitative studies and the tumour appears to differ somewhat in form and nutrition, from various spontaneous, and particularly less rapidly growing, cancers in man and animals. Its growth is essentially infiltrative and fails to stimulate a commensurate growth of stroma from normal tissues including new vessel formation (angiogenesis) and formation of a tumour capsule. Consequently, tumour nutrition largely comes to depend on the resources of existing tissues being invaded by the growing tumour. The latter -progressively destroys normal capillaries and blood vessels in these supportive normal tissues and this causes haemorrhage into the tumour, and oedema. Nutrition and oxygenation become inadequate for tumour growth and rapid tumour necrosis develops. Inadequate nutrition and progressive necrosis appear largely responsible for the curvilinear form of tumour growth and for increases in tumour doubling time for both primary and metastasis. However, incompatibifity between tumour and host (homograft-reactions) and the progressive enhancement of these reactions produced by growth of tumour must also decrease growth rates since doubling times remain constant for longer in immunologically attenuated (irradiated) hosts. Mayneord (1932) proposed a dynamic model of tumour growth based on data provided by the Jensen sarcoma in the rat, in which the growth pattem was governed by a linear law (tumour dimensions with time) as opposed to an exponential relationship, and proliferative growth was confined to an outer narrow surface zone of the tumour. The data obtained by Hirai et al. (1968) for Yoshida sarcoma was found to fit the Mayneord model, as did our own data for both primary and node metastases from P-388 sarcoma in unirradiated (immunologically intact) rats. The data of Hewitt and Blake (1968) for a slow growing syngeneic murine tumour also appears to fit the Mayneord model. However, the rate of growth of P-388 sarcoma in the immunologically intact (incompatible) host depended largely on the size of the challenge dose and the effect of the latter on the rate at which immunity to growth of tumour increased with time. Thus we prefer to analyse tumour doubli-iig time (T) in terms of tumour size (W) rather than age of tumour (t). T and W were linearly related on a log-log plot, but T increased more rapidly if fewer cells were inoculated. Since smaller inocula take longer than larger inocula to grow to a tumour of the same mass, smaller inocula cause more prolonged stimulation of immunological functions and cause a higher level of immunity to develop. For lymph node metastases, T rose more rapidly than for the primary tumour of origin. This suggests that more efficient immunological defences develop in the node, but since the disparity in size between primary and secondary tumours would also affect the efficacy of an immune reaction, this needs to be taken into account. WBI, which suppresses early immunological reactions to a tumour allograft to 'msi'gnificant proportions in the P-388 system and also in the Ehrlich tumour (van den Brenk, 1961), caused growth of both the primary P-388 tumour and its metastases to approximate to an exponential rate of growth during the initial stages when relatively little tumour necrosis had occurred. This finding suggests that immunological incompatibility plays a significant and possibly major role in causing curvilinear forms of tumour growth and increases in doubling times, particularly when this is shown by early infiltrative growth of solid tumours such as poorly differentiated rat sarcomata. The nutrition made available by existing vasculature and stroma, even after the latter has been irradiated during whole body exposure of 570 rad., appears adequate to support exponential rates of growth for a time and supportive angiogenesis appears unnecessary to supplement nutritive requirements at this stage. The factors responsible for linear rates of tumour growth, expressed in terms of tumour dimensions with ageing, in syngeneic tumours, which show no significant immunological incompatibility (Hewitt and Blake, 1968) and possibly in spontaneous tumours, may be related to cell losses resulting from cellular differentiation and to the " controlling " effect imposed on tumour cell growth and differentiation by the stimulation of stroma by a tumour as a co-ordinated trophism. Pressure produced by expansive growth, particularly in more well encapsulated tumours, may be another factor, but no satisfactory explanation accounts for changes in growth rate of solid tumours, which encompasses cellular kinetics, nutrition, immunity and a variety of other pathophysiological factors. Indeed it seems rather remarkable that the many positive and negative factors which interact to determine tumour growth rates allow any general quantitative law of growth to be applicable. Some further difficulties clearly arise in interpreting curves of tumour growth after whole body irradiation of recipients. The irradiation potentially both facilitates growth of tumour by inhibiting immunity and restricts it by reducing the proliferative capacity of host tissues to provide a nutritive stroma. For P-388 sarcoma the ratio M/P (mass of metastasis relative to mass of primary) increased at a linear rate with tumour age. This relationship was independentof size of inoculum aind the state of immunity. The rate of increase in M/P was also relatively constant aiid was reduced only by inoculating fewer cells in immunologically intact animals when the immunological reactions were efficient in destroying less advanced growing tumour. Since rates of increase in M/P were the same for growth of tumour in unirradiated rats given large inocula as in irradiated rats challenged witb few (or many) cells, this suggests that the effects of whole body irradiation on the development and growth of metastases is limited to immunological effects. WBI does not appear to affect significantly other physiopathological mechanisms, local or general, associated with the production and growth of metastases such as exfoliation, transfer, arrest and nutrition of cells in organs.
Sublethal WBI causes marked metabolic changes associated with cellular destruction and other physiological changes in organs and tissues, which might be expected to modify the growth of unirradiated tumour cells deposited in these tissues, but the data obtained fail to support this view.
The progressive increase in immunity produced by growth of tumour in the rat enables unirradiated rats to survive with large and progressively growing primary tumours or with isolated large growing metastases, by destroying newly deposited cells and thereby preventing other metastases developing. It also determines survival of rats in which nodes may remain chronically enlarged due to the dual presence of newly formed and growing and degenerating tumour foci. Similarly, animals which develop very large primaries may remain otherwise healthy and appear free of metastases since a high degree of immunity develops which prevents the establishment and growth of further metastases. Such clinical situations not so different from those experienced from time to time in spontaneous human cancer and its metastases-never occurred after immunological attenuation from WBI. Experience with local irradiation of large growing primary tumours in rats not pre-treated with WBI showed that such locally advanced tumours were relatively readily cured by modest dosages (unpublished results; see also Fig. 1). Furthermore, such local irradiation treatments did not reduce immunity enhanced by previous growth of tumour, since the incidence of subsequent metastasis did not increase and the treated rats were subseqiiently shown to be resistant to further challengesof 106or more P-388 cells.
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Morphological transformation of mouse and rat embryo cells in vitro by an agent from S37 ascites tumour.
When normal rat and mouse embryo cells were treated with a cell free extract of S37 ascites tumour, morphological transformations occurred in both. The transformed cells readily induced lymphosarcoma-type tumours in the mice inoculated when newborn or young adults (8-12 weeks old), but not so readily in rats. Various tests carried out with these cells strongly indicate the presence of an oncogenic and transmissible agent in S37 ascites tumour. This agent appears to be related to mouse sarcoma virus isolated from animals with Moloney leukaemia but differs in only producing characteristic lymphosarcoma-type tumours. ImagesFigs. 1-2Figs. 3-4
SUMMARY.-When normal rat and mouse embryo cells were treated with a cell free extract of S37 ascites tumour, morphological transformations occurred in both. The transformed cells readily induced lymphosarcoma-type tumours in the mice inoculated when newborn or young adults (8-12 weeks old), but not so readily in rats. Various tests carried out with these cells strongly indicate the presence of an oncogenic and transmissible agent in S37 ascites tumour. This agent appears to be related to mouse sarcoma virus isolated from an'lmals with Moloney leukaemia but differs in only producing characteristic lymphosarcoma-type tumours.
THE murine sarcoma viruses (MSV) isolated from animals with Moloney leukaemia are known to induce sarcomas in rats and mice. The changes induced by MSV in cells cultured in vitro have been often reported. This article describes for the first time the changes induced by a cell-free extract of S37 ascites tumour, or by cell-free ascitic fluid/plasma of the tumour, from BALB/c mice. Morphological transformation occurred both in rat and mouse embryo cells in vitro and various tests carried out with these cells strongly suggest the presence of an oneogenic agent(s) in the S37 ascites tumour.
MATERIALS AND METHODS
Animals used throughout this work were inbred BALB/c mice and Wistar or Sprague-Dawley rats.
S37 tumour was maintained in young adult BALB/c mice and serially passaged by intraperitoneal injection of the ascites fluid at intervals of 10-12 days. For experimental use the tumour was aspirated 8-10 days after inoculation and left at room temperature for 15--20 minutes, when a clot was formed separating ascitic plasma/serum from the cells. The mixture was centrifuged at 1400 g for 30 minutes in a swing head centrifuge (MSE) and the supernatant was again spun for 20 minutes and filtered through an 0.45 It membrane filter (" Millipore "). In most of the experiments, after separating blood cells from the ascites tumour, a 5 % suspension of the tumour cells was made in 0-153 m potassium citrate and were then either homogenized in a Waring blender or ultrasonically vibrated for about a minute to break the cell membranes. The homogenate was centrifuged for 20 minutes at 2300 g and the supernatant was recentrifuged for 2 minutes at 1000 g. The fluid was then filtered through an 0-45 /t " Millipore " filter and used for treating the cell cultures. The extracts were normally made fresh for each experiment but on a few occasions when it was used after 3 to 4 days storage at 4' C. the infectivity was slightly impaired.
To test the transmissibility of the agent an extract of the in vitro transformed cells was prepared in a similar way to that described above for S37 tumour. A filtrate of the normal untreated cells was used as a " control " for this experiment.
Monolayer cultures were prepared by trypsinizing 14 to 15 day old eviscerated and decapitated embryos and growing them in 70% medium " 199 " (Glaxo Laboratories), 15% Earle's solution and 14% calf serum. About 0-36 mg./ml. of glutamine, 250 units/ml. of penicillin, 55 units/ml. of streptomycin and 50 units/ml. of Nystatin were also added to the final concentration of the medium. Instead of whole-embryo cells, rat embryo-lung cultures were used on two occasions. Approximately 5 x 105 cells were grown in each Carrel flask or on glass coverslips in hexagonal roller tubes in a rotating drum.
After about 24 hr the cell sheet showed some areas of confluence but there were still empty spaces between most cells. At this time the experimental cultures were treated with S37 ascites tumour extract diluted in the normal nutrient medium. About 12 ml. of this mixture was used to treat the cultures in the Carrel flasks and 5 ml. for those in the roller tubes. The untreated cultures were used as controls and were maintained on the same volume of the standard medium per culture vessel as the treated ones. After incubation overnight the medium was replaced with the same volume of fresh medium (without the tumour extract). For the cultures that were treated more than once the medium was replaced by a fresh dilution of S37 extract in the normal medium. The cultures, however, were not washed before or after the treatment. A single dose of 4 % of the extract or plasma in the medium was sufficient to induce alterations but four consecutive daily treatments of I % dilution were found to be more efficient than a single dose ( Table 1). The cultures were incubated at 37' C. but not in a humidified atmosphere containing C02 in air. They were therefore fed daily with normal growth medium. Untreated cultures were used as " controls ". For microscopical examination cultures on the coverslips were fixed in " Susa and were stained with May-Griinwald Giemsa.
EXPERIMENTAL RESULTS
In about three weeks the cultures had undergone four to five subeultivations (trypsinization) and the growth of cells had diminished considerably. At this time a number of small foci appeared in infected cultures of both rat and mouse embryo cells. The number of foci in rat and mouse cells was dose-dependent. Although a single dose contained the same volume of extract as the four separate doses, more foci seemed to have appeared with the latter dose than with the former. The foci were scattered throughout a sheet of apparently normal cells and when stained with Giemsa appeared as more densely staining areas against a background of lighter staining cells' The medium on these altered cells was more rapidly acidified than that on the normal control cultures.
As the cultures were grown on coverslips in the roller tubes it was not possible to count accurately the number of altered cells in each titration, but approximately 2-3 % of the cell population in each roller tube seemed to have altered first and the rest of the normal cells either lysed or degenerated as the transformed cells progressively grew in cultures.
The transformed cells had a capacity for rapid proliferation and had greater proportion of nuclear mass to cytoplasm and larger average number of nucleoli per nucleus. Cytoplasmic basophilia increased tremendously and with Feulgen staining it was estimated that there was more DNA content in altered cells than in normal cells. In contrast, the normal untreated ceRs were not so basophilic and nuclei were simple, having 2-4 nucleoli per nucleus with very few chromatin granules.
Various tests were carried out to see if the transformations were irreversible and neoplastic. Throughout, the medium used was the same as described above for the experiment. Whereas unaltered normal cells were incapable of sustained multiplication in suspension cultures, the transformed cells proliferated happily under identical conditions. Although some of these cells did attach to the glass surface of the vessel in which they were grown in suspension, most of the cells formed large clumps measuring up to 1-2 mm. These clumps could be serially subcultivated in suspension.
The behaviour of cells in tissue culture known as contact inhibition was also one of the parameters by which altered cells were distinguished from the unaltered ones. Monolayering of normal, untreated cells in these experiments reflected the efficiency of contact inhibition and the transformed cells piled up and usually manifested a distorted random cellular array.
The only indubitable proof for mahgnancy seemed to be the demonstration of progressive growth of cells leading to the death of the animal when inoculated in the appropriate host. Tumours developed in 88% inoculated BALB/c mice but only in two rats out of 67 inoculated when newborn (a day or less than a day old) and occasionally (33%) in mice inoculated as young adults but not rats (Tables II and 111). Splenomegaly, quite often accompanied by hepatomegaly, developed in 90% mice, but not in rats.
Whether the cells were inoculated subcutaneously or intraperitoneally, lymphosarcoma always developed. A subcutaneous tumour was never observed at the site of inoculation even after injecting a large number of transformed cells' The commonest sites for the tumours were on or near the mesentery, abdominal cavity, axillary lymph nodes, diaphragm and, in some cases, invading the lungs and surrounding tissue. There were irregular masses of lymphosarcoma cells similar to those of solid tumours seen elsewhere, in the spleen and liver. The earliest tumours were obtained in 10-15 days but in this case the number of cells inoculated was 8 x 107. Most mice, if not otherwise killed, died within 7-8 months, some much earlier than this.
DISCUSSION
As the control (untreated) cells did not produce tumours when inoculated in animals even after several months of culturing in vitro, it is deduced that the transformation in the treated cells must have been caused by an oneogenic agent which is present not only in S37 tumour cells but is also released in the ascitic fluid of the tumour bearing animals. (Table IV).
The virus genome is probably present in the cells even after several months of serial subcultivation in vitro. This is evident by the growth of tumours (lymphosarcomas) when both the rat and mouse cells transformed 8 months previously in vitro are inoculated in mice.
The agent from S37 ascites tumour is completly inactivated at 56' C. for 30 minutes and both rat and mouse normal embryo cells treated with heated filtrate/ extract of the ascites tumour do not produce any lesions when inoculated in mice or rats.
Comparison with other murine sarcoma viruses Moloney (1960) extracted a leukaemia virus (MLV) from solid S37 tumour tissue. Harvey, in 1964, and Moloney, in 1965/66, isolated viruses from MLV which produce sarcomas and other lesions in rates and mice. These agents have been termed as Murine Sarcoma Viruses (MSV) and will be referred to as MSV (Harvey) and MSV (Moloney) throughout the present discussion.
Since the isolation of MSV several investigators have tested the virus in vitro as well as in vivo. Hartley and Rowe (1966), Boiron, et al. (1967) and Yoshikura, et al. (1968) have shown that MSV (Moloney) induced morphological transformation in normal mouse embryo cultures. Similar changes have been reported by Simons, et al. (1967) for MSV (Harvey).
Tumour induction in mice in vivo has been demonstrated by Chesterman, et al. (1966) by inoculating the animals with MSV (Harvey). Fefer, et al. (1967) and Chirigos, et al. (1968) have also induced tumours in mice by inoculating MSV (Moloney). Tumours were also produced when Chesterman, et al. Perk, et al. (1968) injected MSV (Harvey) and MSV (Moloney) respectively in rats. Merwin and Redman (1969) have shown that an agent(s) from S37 solid tumour causes skeletal changes and reticulum tissue disorders including splenomegaly and lymphocytic neoplasms in BALB/c mice. The agent is very similar to MLV and is derived from the same strain of S37 tumour as used by Moloney for the extraction of MLV and later MSV (Harvey and Moloney).
Since Merwin and Redman's paper was published in August (1969), the writer has been examining the animals for the skeletal changes, but so far none of the experimental animals has developed any such disorders. It is nevertheless possible that these changes, if present in the animals autopsied before August, 1969, have been overlooked because the writer was not specifically looking for them-However, these skeletal disorders are not peculiar to S37 Aerived agent as van Gorp et al. (1969), Upton and Furth (1955) and many others have observed similar changes in animdls with viruses other than used by Merwin and Redman (1969).
As far as morphological transformation of mouse and rat embryo cells in vitro is concemed, the present agent from S37 ascites tumour, appears to be related to MSV (Harvey and Moloney). Like MSV this agent is also inactivated at 56' C. for 30 minutes but at 37' C. for this period, the infectivity is unimpaired. It, however, differs from MSV in the following features: Whereas with MSV (Harvey) the site of tumour depends on the route of inoculation, the present agent produces the same type of tumour, i.e, a lymphosarcoma, no matter how the cells are introduced in animals. Solid subcutaneous tumours are developed at the site of inoculation with MSV (Harvey) but no such tumours have ever been observed in the writer's experimental animals. Even when a large number of cells (8 x 107) are inoculated subcutaneously a lymphosarcoma is developed. This indicates that the tumours are produced, not by local growth of cells, but by the agent being carried by the lymphatic system to various parts of the body and causing neoplastic changes. Tumours obtained by inoculation of in vitro transformed cells have been serially passaged in mice by subcutaneous or intraperitoneal routes. In both cases lymphosarcoma developed. After nearly 13 months of serial subcutaneous transplantation of tumours in vivo (15th to 18th passage) there is now a slight evidence of a few cells of one particular tumour line, growing flat under the skin at the site of inoculation. Even this feature always accompanies a lymphosarcoma. However, it appears that the subcutaneous growth is due to the adaptation in vivo after prolonged serial transplantation. Pleural effusions and cystic swell'ings in the region of lymph nodes and other organs occur very frequently i'n animals inoculated with MSV (Harvey). No such lesions or serosal reactions have ever been located in any of the several hundred animals examined during routine autopsies.
Another major difference between the agent from S37 ascites tumour and MSV (Harvey and Moloney) is that whereas the latter strains produce tumours in both rats and mice the present isolate only develops tumours in mice. Rat cells which were transformed in vitro by the S37 ascites tumour, failed to produce tumours or other lesions when inoculated in rats. Both rat and mouse embryo cells transformed in vitro, readily induce tumours in mice. Only 2 rats out of 67 inoculated when newborn with in vitro transformed rat cells developed tumours. One rat which had very much enlarged thymus and the right axillary node died after 7 months, and the other which was inoculated with transformed cells twice within a week, died after I 1 days. The first inoculation of ceRs was 12 hours after birth and the second followed after 7 days of the first inoculation. Post-mortem examination revealed a mass of neoplastic cells fiHing the abdominal cavity.
The first rat which died could have had spontaneous tumours, but the causes for the second rat's death are very intriguing; as the rest of the rats from the same litter which were inoculated twice at the same times as the one which died, seemed to have developed resistance to the production of tumour. The reason for this characteristic resistance of rats to the present biological agent are still undetermined.
Although haemagralutination and other specific tests were not carried out, the evidence is strongly against the possibility that an admixture of polyoma virus may be responsible for tumour production. No salivary gland tumours, which are characteristic of polyoma virus, have ever been observed. The present agent is inactivated at 56' C. for 30 minutes whereas polyoma resists it.
Since the transformations occurred in a laboratory in which any other virus was not handled, the repeated transmission of the agent in the mouse and rat embryo cells in vitro, implies the presence of a virus or viruses.
Whether the tumorigenic properties of the agent from S37 asictes tumour are due to a mutant of MLV or MSV or to a latent " passenger " virus present specifically in BALB/c ascites tumour or to a mixture of such a virus with Moloney virus is still to be determined. It is possible that the extract of this tumour contains more than one agent. I would like to thank Dr. A. K. Powell for his help and encouragement and the British Empire Cancer Campaign for Research for the financial support. I am also indebted to Dr. R. J. C. Harris of the Imperial Cancer Research Fund for his advice and helpful criticisms throughout the preparation of this manuscript. The skilful technical assistance of Mr. F. Butcher is also gratefully acknowledged.
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v2
|
2018-04-03T00:05:41.026Z
|
1971-03-01T00:00:00.000Z
|
9111930
|
s2ag/train
|
Proliferating Brenner tumors
The great majority of Brenner tumors are benign, but a few are frankly malignant. The rare proliferating Brenner tumor is a third variant intermediate between the benign and malignant forms. Characteristic areas of this tumor show an unusual degree of epithelial proliferation and morphologically resemble low‐grade (papillary) transitional cell carcinoma of the urinary bladder. The papillary tumor tends to grow within cystic spaces, and the epithelial component does not invade the tumor stroma. In our 3 cases, adjacent areas of typical Brenner tumor were observed. The tumors were all confined to the ovary, and none has recurred or metastasized. In one case, the patient has been free of tumor for 8 years. These tumors give additional support to the concept that Brenner tumors are composed of epithelium of urinary tract (urothelial) type.
|
v2
|
2018-04-03T00:21:39.797Z
|
1971-03-01T00:00:00.000Z
|
11692513
|
s2ag/train
|
Adenocarcinoma of the head and neck.
Among 792 patients treated for malignant diseases of the head and neck, 78 had adenocarcinoma (cylindroma, acinic cell, miscellaneous solid adenocarcinomas). The 63 determinate patients are reviewed. Adenocarcinoma was found frequently in women, in a younger age group, and in nonsmoking, nonalcoholics. Wide surgical excision was necessary and regional recurrence and distant metastases were common. Positive regional lymph nodes were sometimes present before any treatment. Radiation therapy was given to some persons postoperatively and was felt to be helpful, but not curative in cylindroma. Chemotherapy was not found helpful. There are 36 patients living without evidence of tumor from two to over ten years. Five patients died from other causes. Twenty-two patients died from their tumor, 15 within five years of diagnosis.
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v2
|
2018-04-03T00:22:48.045Z
|
1971-03-01T00:00:00.000Z
|
11828627
|
s2ag/train
|
Differences in growth and morphology between the spontaneous C3H mammary carcinoma in the mouse and its syngeneic transplants
The rate of growth of the C3H spontaneous mammary carcinoma in the mouse was compared with that of its first and 900th generation (C3HBA) syngeneic transplants. The microscopic appearance, change in relative volume of tissues, and relation of blood vessels to the tumor nodules were compared in the 3 tumors. The initial rate of growth and the retardation which subsequently occurred increased with transplantation. The relative volume of cancer cells decreased and necrosis increased with tumor growth in each of the tumors; the change was least in the spontaneous tumor and increased with transplantation. Blood vessels were confined to the internodular tissues in the transplants but were also present within the nodules in the spontaneous tumor. The results stress the importance of blood supply in determining retardation in the rate of tumor growth. It also emphasizes the care that should be taken in selecting an animal tumor model that simulates the human tumor, when the results are applied to the treatment of cancer in patients.
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v2
|
2018-04-03T01:31:58.535Z
|
1971-03-01T00:00:00.000Z
|
29920686
|
s2ag/train
|
Corticosteroid effect on transplantable rat glioma.
Two groups of rats bearing a transplanted glioma were given methylprednisolone acetate on the tenth, 13th, and 19th days postimplantation. Group 1 animals and half of the group 2 animals were killed on day 21; the remaining group 2 animals were allowed to die from their tumor. Average treated tumor wet weights were 36.25 mg (group 1) and 34.1 mg (group 2), those untreated were 157.5 mg (group 1) and 113 mg (group 2). Group 2 control animals survived an average of 28.7 days, group 2 treated animals an average of 37.4 days. Water content and electrolyte levels in surrounding brain indicated a concomitant antiedema effect. From these data, methylprednisolone appears to be effective against primary brain tumors.
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v2
|
2018-04-03T02:15:17.888Z
|
1971-03-01T00:00:00.000Z
|
32853232
|
s2ag/train
|
Lipids in brain tumors.
ELATIVELY few studies have been performed on lipids of brain tumors. The pioneer study of Brante ~ showed that brain tumors in general have a lipid content lower than normal brain and contain esterified cholesterol, which is absent from normal adult brain tissue. Phospholipids are also present in small amounts/The presence in brain tumors of free fatty acids, triglycerides, and cholesterol esters, and certain lipids absent from normal brain, has been detected in our laboratory/Azarnoff and coworkers t demonstrated that human glioblastomas, astrocytomas, and other intracranial tumors are capable of incorporating 14C-acetate into cholesterol in contrast with normal brain tissue which is known to synthesize cholesterol only to a limited extent. Paoletti, et al./ demonstrated that the Zimmerman ependymoma can convert various precursors into cholesterol much more efficiently than normal brain of the same animals. A typical feature of brain tumors is the presence of desmosterol (24-dehydrocholesterol), which differs from cholesterol only by an extra double bond in the lateral chain. This sterol is the last precursor of cholesterol in one of its biosynthetic possible routes. However, in the liver desmosterol does not accumulate, despite high levels of cholesterol synthesis; in brain during maturation, however, large amounts of desmosterol are found as well as in human glial tumors? ,~ In recent experiments, large quantities of desmosterol were detected in brain tumors of the rat induced in our laboratories by nitrosourea derivatives according to Druckrey, et al? In ethylnitrosourea-induced oligodendrogliomas, desmosterol accounted for 10% to 15% of the total sterols. 12 Desmosterol was considerably higher in some neurinomas, which is not surprising since these tumors are quite malignant and fast-growing when compared with human neurinomas. The presence of consistent pools of desmosterol in brain tumors is connected with both the high sterol biosynthetic rate and with a blockade of desmosterol transformation into cholesterol. The ability of human brain tumors to synthesize both desmosterol and cholesterol from mevalonate was checked in vitro and compared with that of normal brain tissue. The results G indicate that the incorporation of mevalonate in the unsaponifiable lipid fraction is very low for the slow-growing neurinomas, which do not synthesize cholesterol, while the mest notable difference between glial tumors and normal brain is at the sterol level only. In fact, normal brain incorporated less radioactivity into sterols, and most of it was detected in cholesterol. The reverse was found in glial tumors, which showed a high sterol synthesis, and the ratio between synthesized desmosterol/cholesterol was higher in the glioblastomas than in other less malignant gliomas. Comparable results were obtained by incubating in vitro an experimental ependymoblastoma, which, after 1 hour of incubation, contained a twofold increase of radioactivity in desmosterol than in cholesterol. Desmosterol accumulation in brain tumors may be magnified by Triparanol administration. This drug, inhibiting desmosterol reductase, induces accumulation of desmosterol in blood but not in mature brain. This was demonstrated in mice with experimental
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v2
|
2018-04-03T02:31:40.929Z
|
1971-03-01T00:00:00.000Z
|
33911508
|
s2ag/train
|
AN EVALUATION OF RADIOIODINE‐LABELED 5‐IODO‐2′‐DEOXYURIDINE AS A TRACER FOR MEASURING CELL LOSS FROM SOLID TUMORS *
Radioiodine‐labeled 5‐iodo‐2′‐deoxyuridine (IUdR) has been evaluated as a tracer for measuring cell loss from C3H mouse mammary tumors. This has been accomplished by considering the problems of label specificity, chemical and radiation toxicity, and reutilization; and by comparing the estimate for cell loss, as obtained here, to another independent estimate previously reported for tumors from the same slow‐growing line.
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v2
|
2018-04-03T04:24:56.315Z
|
1971-03-01T00:00:00.000Z
|
38829891
|
s2ag/train
|
The age related responses of New Zealand mice to a murine sarcoma virus.
The Moloney strain of murine sarcoma virus (MSV-M) rapidly induces soft tissue tumours in mice of all ages. Immunologically competent mice can spontaneously regress these tumours, and the regression time is an indication of the degree of immunologic reactivity. Using these parameters, New Zealand Black (NZB), New Zealand White × New Zealand Black F1 (B/W), and NIH Swiss mice develop cell mediated immune responses at an early age compared to five other mouse strains. 8–11-month-old NZB and B/W mice of both sexes show depressed immune responses when compared to 6-week-old controls. The responses of 10–11 month old female BALB/c mice were identical to 6-week-old controls. Older NZB and B/W mice spontaneously develop autoimmune disease. Measurement of autoimmune parameters in the older New Zealand mouse strains indicates that immune depression precedes the onset of detectable autoimmune disease.
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v2
|
2018-04-03T05:39:05.658Z
|
1971-03-01T00:00:00.000Z
|
23151346
|
s2ag/train
|
The vectorial release of nascent immunoglobulin peptides.
A microsomal preparation from a mouse plasmacytoma, MOPC 47A, that secretes immunoglobulin A was used to study the release of nascent immunoglobulin peptides in vitro. Nascent chains were released with puromycin and characterized with specific antiserum against the immunoglobulin product of the tumour. When the tissue had been prelabelled with [(3)H]leucine the experiments were complicated by the large background of completed radioactive polypeptides in the microsomal preparation. Up to one-third of the released radioactivity in the microsomal preparation could be recognized as immunoglobulin. With [(3)H]-puromycin as the radioactive label, however, the results are much easier to interpret, although the proportion of released radioactivity that can be identified as immunoglobulin is lower (up to one-tenth). Both types of experiment demonstrate that all of the recognizable nascent immunoglobulin chains remain in association with the microsomal vesicles after release from the ribosomes.
|
v2
|
2018-04-03T02:33:05.027Z
|
1971-03-15T00:00:00.000Z
|
34252196
|
s2ag/train
|
Electron microscopic detection of transforming viruses induced by cell association. I. The SV40 model
This paper describes a study on the application of electron microscopy for rapid detection of SV40 particles rescued from transformed cells by co‐cultivation or fusion of these cells with either permissive or naturally insusceptible cells and discusses the utility of the electron microscope as a rapid means for the detection of virus recovered from human or animal tumors, as well as from other diseases where viral etiology seems the most probable.
|
v2
|
2018-04-03T00:33:35.220Z
|
1971-03-18T00:00:00.000Z
|
12703133
|
s2ag/train
|
How to select cancer cells with the proper qualifications.
A few years ago Todaro and Green1 developed a cell-culture line of mouse fibroblasts that exhibited an unusual degree of growth control. This line, called the 3T3 mouse line, consists of fibroblasts or fibroblast-like cells that grow as a monolayer. When the culture reaches a certain density and the cells are confluent or near confluent, cellular proliferation ceases almost completely. To be sure, this growth control is only relative since, by simply increasing the concentration of serum, these cells continue to proliferate and divide even after they have reached confluence.2 However, under constant culture conditions, constant frequency of medium changes . . .
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v2
|
2018-01-21T21:54:47.218Z
|
1971-04-01T00:00:00.000Z
|
19875095
|
s2ag/train
|
Prospective study of dog bite and childhood cancer.
Summary Approximately 50,000 children who were bitten by dogs have been followed for 5 or more years to assess their risk of dying from cancer. An analysis was made that measured the immediate and continuing risk of death and also allowed for a latent period and an interval between onset and death. Total observed leukemia-lymphoma deaths were less than expected until 4 or more years after the bite. Standardized leukemia-lymphoma mortality ratios for the age group 10 to 14 rose to approximately 3-fold following an interval of 4 or more years after the bite, a result which is almost statistically significant at the 5% level. However, this finding was not consistent for other age groups. These observations provide interesting but inconclusive epidemiological support for the hypothesis that dog bite is one type of initiating event in the occurrence of leukemia-lymphoma in children. Further inquiry is needed. The overall results of this study indicate that children bitten by dogs are not at substantial risk of developing leukemia-lymphoma.
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v2
|
2018-04-03T00:05:57.086Z
|
1971-04-01T00:00:00.000Z
|
9197984
|
s2ag/train
|
Facilitation of tumor growth by syngeneic normal cells mixed with tumor cells in vitro
Facilitated tumor growth was observed in syngeneic animals after the subcutaneous inoculation of these animals with normal syngeneic spleen cells and tumor cells previously mixed in vitro. Tumor incidence, latency, and growth rate appear quantitatively directly related to the ratio of spleen cells to tumor cells in the challenge inocular. This phenomenon was consistently demonstrated in two syngeneic murine tumor‐host systems and one sygeneic rat system. Facilitated tumor growth is not a specific property of the spleen cells in these mixtures. Mixtures of liver cells and tumor cells produce identical results. Reproducible facilitated growth of tumor isografts by mixture with normal spleen cells, however, must be considered in the design and interpretation of all in vivo neutralization experiments.
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v2
|
2018-04-03T01:22:50.170Z
|
1971-04-01T00:00:00.000Z
|
29102968
|
s2ag/train
|
A new concept for hepatic lobectomy. Experimental studies and clinical application.
This method for partial hepatectomy enables the liver to first be isolated from the circulation and then resected or otherwise repaired. Excision of a segment of the vena cava which may also be involved by tumor may be carried out. Experiments on dogs have indicated that immediate function of the remaining portion of the liver which had been isolated is satisfactory. The concept has been applied clinically in two patients.
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v2
|
2017-04-13T17:12:30.931Z
|
1971-05-01T00:00:00.000Z
|
8059649
|
s2ag/train
|
Comparative transfer RNA methylase capacity in mouse ascites tumors and in their derived tumorigenic and nontumorigenic cell cultures.
The transfer RNA (tRNA) methylase activity from two types of mouse ascites tumor cells (TA3 adenocarcinoma and 6C3HED lymphosarcoma) was compared to that of derived tumorigenic and nontumorigenic cultured cells of the same cell types. The nontumorigenic cells had lost their ability to produce tumors on back transplantation by extended passage in cell culture. The two ascites cell types differed in their capacity to methylate Escherichia coli B tRNA. The TA3 cells had an approximately 30% greater capacity than did the 6C3HED cells. There was no difference in the methylating capacity of either cell line during in vivo tumor development. Cell extracts from 9-day TA3 ascites tumors and from TA3 tumorigenic cultured cells exhibited between 50 and 60% more methylating ability than did extracts from nontumorigenic cultured cells of the same cell line. Contrary to this, 9-day 6C3HED ascites cell extracts showed no difference in tRNA methylase activity when compared to extracts from 6C3HED nontumorigenic cultured cells. These results indicate that a quantitative alteration in tRNA methylase activity may not necessarily be associated with loss of tumorigenicity in this ascites cell system.
In a control experiment, it was found that the tRNA methylase activity of a solid, s.c., 3-methylcholanthrene-induced transplantable mouse tumor was 35% greater than that of normal mouse liver or kidney and 80% greater than that of normal mouse lung. This observation is in accord with previous reports by other authors that tRNA methylase activity of some neoplastic tissues and cells is increased in comparison with normal tissue.
|
v2
|
2017-07-19T06:39:57.475Z
|
1971-05-01T00:00:00.000Z
|
21132205
|
s2ag/train
|
Transfer RNA modifications and synthesis in animal cells.
A review of alterations found in chromatographic patterns of specific species of tRNA's from both developing systems and tumors is presented. Such differences have been observed in the early stages of sea urchin development and between tumors and their tissues of origin. In particular, the meaning of differences found between tRNA from Morris hepatomas and normal rat liver is discussed. Evidence is presented that tRNA synthesis in mammaliam cells proceeds via a short-lived precursor state and that the finished tRNA's are heterogeneous in size. It is suggested that the chromatographic variations noted in these systems may reflect differential gene transcription.
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v2
|
2018-04-03T01:49:35.549Z
|
1971-05-01T00:00:00.000Z
|
31178929
|
s2ag/train
|
The effect of drugs on clinical laboratory determinations.
Many of the physiologic and biochemical changes produced by drugs within the body are susceptible to testing. An incomplete data bank sometimes prevents us from realizing that the effects and measurements may be in areas other than the one of primary interest. If laboratory people are unable to recognize this as a problem, the clinician is also unlikely to do so. The results are sometimes disastrous to the patients to whom we are all ultimately responsible. The literature related to drug interactions with the effect on patients and laboratory determinations has become immense in the past few years. The purpose of this discussion is to underscore this problem of mounting importance to clinical chemists as well as physicians. To illustrate the point, an article by Llerena and Pearson (1) demonstrated the interference of nalidixic acid (Negram) with urinary 17-ketosteroid determinations. False elevations of urinary 17-ketosteroid and 17-ketogenic steroids were found in two patients who were taking this antibacterial agent, frequently used in urinary tract infections. They were erroneously thought to have an adrenal tumor and one of them was even subjected to exploratory surgery in a vain attempt to find it. The spurious nature of the elevations was later documented, after it was realized that both patients were taking the same drug. This example demonstrates the caution with which laboratory data must be interpreted. Many substances interfere with urinary steroid determinations (2) and it is therefore best to insist that, when possible, the patient abstain from all medication for an appropriate period of time before and while the specimen is being collected. A history of drug ingestion would also be a helpful thing to have at hand so that possible interferences with a true
|
v2
|
2018-04-03T02:33:05.027Z
|
1971-05-01T00:00:00.000Z
|
33987214
|
s2ag/train
|
Osteogenic sarcoma of the somatic soft tissues. Clinicopathologic study of 26 cases and review of literature
Twenty‐six cases of osteogenic sarcoma of the somatic soft tissue were found during a review of more than 2,100 somatic soft‐tissue sarcomas in the files of the Mayo Clinic. These cases bring the total reported in the English literature through 1968 to 94. In the present series, no tumors occurred during the first two decades of life, in contrast to those primary in bone in which the peak incidence is in the second decade. Twenty‐four tumors were found in the limbs and limb girdles, and two in the retroperitoneum. The spectrum of histologic patterns as described for osteogenic sarcoma in bone was applied to establish the diagnosis. Five tumors were subtyped as chondroblastic, 10 as fibroblastic, and 11 as osteoblastic; all were poorly differentiated. Sarcomas with benign osseous or chondromatous metaplasia, mixed mesenchymal sarcomas, pseudo‐malignant tumors of soft parts (niyositis ossificans), and parosteal osteogenic sarcomas were excluded. In the series, 21 patients had died. Of the 5 living patients, only 2 are long‐term survivors (8 and 12 years). The average survival period was between 3 and 4 years, although 3 patients died with recurrent or mctastatic disease 7, 9, and 14 years after initial treatment. No histologic difference could be detected between tumors with a rapid clinical course and those with a prolonged course.
|
v2
|
2018-04-03T02:54:32.834Z
|
1971-05-01T00:00:00.000Z
|
35460826
|
s2ag/train
|
The alkylation of transfer RNA by enzymes from embryonic, neoplastic, and ethionine-treated liver tissues.
Several aspects of bioalkylation of tRNA are reviewed. Recent evidence for the following is presented: ( a ) the ion effect on tRNA methylase activity is due to changes in tRNA conformation; ( b ) tumor extracts methylate 2′- O positions; ( c ) tRNA methylases are unable to methylate homopolymers and copolymers, including AUGG copolymers, yet are able to methylate tRNA fragments; ( e ) adult and embryonic cells contain different forms of leucyl-tRNA's; ( f ) certain Escherichia coli tRNA's are preferentially methylated by hepatoma enzymes when compared with liver enzymes; and ( g ) 1% ethionine diets induce an 80% increase in mouse liver tRNA methylase activity within a 10-day period. It is proposed that alterations of minor nucleotides in the maturation of tRNA could be basic to the carcinogenic process.
|
v2
|
2018-04-03T03:36:07.987Z
|
1971-05-01T00:00:00.000Z
|
7068758
|
s2ag/train
|
Angiocardiography in huge hypertrophy of the thymus.
H UGE hypertrophy of tile thymic gland in infants is not uncommo&’6’#{176}’ 18,20,25,27 and at times a differential diagnosis from mediastinal tumors, intrapericardial tumors, pericardial effusion, and cardiomegalv, is necessary. Therefore, knowledge of the angiocardiographic findings in patients in whom an unusual or bizarre enlargement of this gland is present, appears to be of value. The medical literature on this subject is very sparse.5’6 There are other methods to differentiate hypertrophy of the thymus from cardiomegaly and mediastinal tumors,”4”6”8’2029 but in this article we wish to present our angiocardiographic experien ce.
|
v2
|
2018-04-03T04:20:55.636Z
|
1971-05-01T00:00:00.000Z
|
38562189
|
s2ag/train
|
The induction of pulmonary neoplasms in mice by isonicotinic acid hydrazide.
Mice have a high incidence of spontaneous pulmonary neoplasms. Inbred strains with particularly high spontaneous incidence are also more susceptible to induction of such neoplasms by a variety of oncogenic agents, reflecting a powerful genetic factor affecting tumor susceptibility. The various oncogenic agents might act by accelerating the inherent neoplastic predeliction of mouse pulmonary tissue. Results of this study showed that the incidence of lung tumors in two strains of mice was increased by administration of isoniazid. These data support other reports of the oncogenic effect of isoniazid for certain strains of mice.
|
v2
|
2018-04-03T05:08:41.732Z
|
1971-05-01T00:00:00.000Z
|
19211180
|
s2ag/train
|
Malignancy Associated Changes in False Negative Sputum Specimens
100 consecutive sputum specimens from 100 patients of this Institute with squamous and/or cylindrical cells containing hyperchromatic nuclei arrested in telophase (MAC-A) were evaluated. Retrospective analysis of clinical data revealed in 88 cases a proven malignant tumor; 6 cases were still under investigation with strong clinical evidence of lung cancer and 6 cases had no malignant tumor. In 34 cases malignant tumor cells (MTC) were found in the first sputum specimen, and in a further 17 cases MTC appeared in repeated sputa. The strong coincidence (88%) of cells with MAC-A in sputum specimens, with or without MTC, and malignant tumors, either in the respiratory tract or elsewhere is preliminary evidence for the suitability of MAC-A as a diagnostic aid. The presence of MAC-A positive cells indicates the need for further clinical search for possible occult malignancies.
|
v2
|
2014-10-01T00:00:00.000Z
|
1971-06-01T00:00:00.000Z
|
9844748
|
s2orc/train
|
Human lymphoblastoid cell lines and Epstein-Barr virus: a review of their interrelationships and their relevance to the etiology of leukoproliferative states in man.
The Epstein-Barr virus (EBV), is a herpes-like virus found in continuous cultures of human leukocytic cells derived from certain tumors, from bone marrow and peripheral blood leukocytes of patients with diseases such as leukemia and infectious mononucleosis, and from the blood leukocytes of some normal persons. EBV was discovered in lymphoid cell cultures originating from Burkitt's lymphoma (BL); because it was the first virus to show a regular association with a human malignant tumor, it has received a great deal of attention from experimental oncologists, virologists, epidemiologists, and clinicians in the six years since its discovery. The hypothesis that viruses are a cause of human malignant disease has been explored with increasing energy since studies in lower animals have demonstrated the oncogenic potential of these agents. The RNA tumor viruses of chickens,' mice,2 and cats' have been considered likely models for human leukemia and lymphoma because of the similarity of the diseases in lower animals and in man, and because these agents produce tumors in the species in which they are found in nature. Polyoma and simian virus 40 (SV40), small DNA viruses of the papova group, do not usually produce tumors in their natural host but they are important tools in experimental viral cancerigenesis, because they offer the promise of close genetic and biochemical analysis of malignant transformation in vitro. Some types of human adenoviruses, larger DNA viruses, cause tumors in experimental animals and produce malignant transformation of animal cells in vitro.' Since some adenovirus types are oncogenic and others are not, a great deal of research has been directed toward understanding these differences which, at present, are not fully explained at a molecular level. More recently a fourth group of animal viruses, the herpes group, which are still larger, more complex enveloped viruses with double-stranded DNA, have been regularly associated with tumors both in lower animals and in man. The herpes virus of the Lucke frog renal adenocarcinoma was dis-
The Epstein-Barr virus (EBV), is a herpes-like virus found in continuous cultures of human leukocytic cells derived from certain tumors, from bone marrow and peripheral blood leukocytes of patients with diseases such as leukemia and infectious mononucleosis, and from the blood leukocytes of some normal persons. EBV was discovered in lymphoid cell cultures originating from Burkitt's lymphoma (BL); because it was the first virus to show a regular association with a human malignant tumor, it has received a great deal of attention from experimental oncologists, virologists, epidemiologists, and clinicians in the six years since its discovery.
The hypothesis that viruses are a cause of human malignant disease has been explored with increasing energy since studies in lower animals have demonstrated the oncogenic potential of these agents. The RNA tumor viruses of chickens,' mice,2 and cats' have been considered likely models for human leukemia and lymphoma because of the similarity of the diseases in lower animals and in man, and because these agents produce tumors in the species in which they are found in nature. Polyoma and simian virus 40 (SV40), small DNA viruses of the papova group, do not usually produce tumors in their natural host but they are important tools in experimental viral cancerigenesis, because they offer the promise of close genetic and biochemical analysis of malignant transformation in vitro. Some types of human adenoviruses, larger DNA viruses, cause tumors in experimental animals and produce malignant transformation of animal cells in vitro.' Since some adenovirus types are oncogenic and others are not, a great deal of research has been directed toward understanding these differences which, at present, are not fully explained at a molecular level.
More recently a fourth group of animal viruses, the herpes group, which are still larger, more complex enveloped viruses with double-stranded DNA, have been regularly associated with tumors both in lower animals and in man. The herpes virus of the Lucke frog renal adenocarcinoma was dis-ML covered in the 1930'se and its morphology described in 1956.' In the last year its oncogenic capacity was demonstrated experimentally by the induction of tumors on the mesonephric ridge of tadpoles.7 A herpes virus has been found in Marek's disease, a lymphoma of chickens; the agent cultivated in tissue culture is able to reproduce the disease upon inoculation of susceptible birds.8 Preliminary field trials of an attenuated virus vaccine suggest that this commercially important avian tumor can be prevented by immunization. 9 In the past year Melendez and his co-workers'0 reported that herpes virus saimiri, indiginous to the squirrel monkey, produces lymphoma and occasionally leukemia on inoculation into cotton top marmosets and owl monkeys, two other South American primates. Finally, two herpes viruses of man, the genital strain, or sub type 2 of herpes virus hominis,' and EBV have received attention as possible tumor inducers.
These examples of the close association of herpes viruses with tumors have widened interest in EBV as a candidate human-tumor virus. Furthermore, in early 1968, W. and G. Henle and their collaborators reported that an immune response to EBV developed during the course of infectious mononucleosis (IM).' The association of the virus with this long enigmatic disease, which to some appeared as an abortive malignancy, has generated even more interest.?s For reasons which will be discussed, it is not possible to state with absolute certainty that EBV is the cause of Burkitt's lymphoma or infectious mononucleosis, the two conditions with which it has been associated most closely. Students of this virus have become polarized into two camps; one group proposes that EBV is the etiologic agent of IM, and perhaps a cocarcinogen with some other factor in BL; the other group considers that EBV is a passenger virus with an attraction for poorly differentiated lymphoblastic cells. It is the purpose of this review to analyze the published information about the virus and to attempt to correlate the available evidence with the central question of whether the virus is pathogen or passenger. No attempt has been made to review the clinical aspects, pathology, or therapy of BL or IM, both of which have been comprehensively described in monographs recently published."" Instead, attention will be focused on the behavior of EBV virus in vitro and on serologic and epidemiologic studies of EB virus infection.
Discovery of EBV and its association with Burkitt tumor cells
In 1958, Burkitt made his original observations on an unusual tumor of the jaw occurring in children of Uganda.' The geographic distribution of the disease was of special interest; the disease predominated in hot, wet lowlands. Because this pattern coincided with the distribution of arthropod vectors, Burkitt considered that a mosquito-borne agent might be the cause. Accordingly, specimens of tumor tissue were submitted to several virologic facilities, where a variety of microorganisms, including reovirus,17 herpes simplex virus"8 and mycoplasmas," were recovered, although none were isolated regularly. In late 1963, Epstein, Barr, and Achong established several continuously growing in vitro cell lines with lymphoblastic features from specimens of tumor tissue.`Some characteristics of these human lymphoblastoid cell lines (HLCL) were morphology suggesting an immature state of the lymphocyte series, continuous rapid growth after 4-8 weeks in culture, and failure to adhere to glass. Several cell lines examined with the electronmicroscope revealed virus-like particles of a size and structure characteristic of the herpes group.' Such particles were generally identified in only a small proportion of the in vitro cell population.
Origin of continuous lines of lymtphoblastoid cells and presence of EBV therein
Soon after Epstein and his associates established cell culture lines from Burkitt lymphoma, such cell lines were derived from patients with a variety of diseases and examined for viral particles by electronmicroscopy and later for viral antigen by the immunofluorescent (IF) assay on fixed cells (Table 1). Lymphoblastoid cell lines were grown from BL by several workers and nearly all contained EB viral particles.`"t The major exception was a BL line designated Raji' which, despite extensive examination, has not revealed complete virus.
Itakawa and Grace' and Foley and co-workers? found that HLCL could be established from peripheral blood leukocytes of leukemia patients. Eventually HLCL were derived from the peripheral blood of patients with acute leukemia of the myeloblastic'°and lymphoblastic types' and from patients with acute and chronic myelogenous leukemia.'-" HLCL originating from patients with acute leukemia often, though not invariably, contain EBV virions. Moore and his co-workers found herpes-like particles in lines from acute leukemia ;' three lines derived in our laboratory from children with leukemia contain EBV antigen. Certain HLCL from leukemia patients do not contain EBV antigen or particles, such as the CCRF-CEM line, which has been extensively studied by Foley and co-workers.' Lymphoblastoid lines were also derived from lymph node biopsies of reticulum cell sarcoma, mycosis fungoides, Hodgkin's disease, multiple myeloma, carcinoma of the lung, and from a spleen removed because of demonstrated in a series of cases that blood leukocytes from patients with IM grew readily in the acute phase of the disease and frequently, though not invariably, during convalescence or many years later. Most HLCL derived from patients with IM contain detectable EBV." " Lymphoblastoid lines have been grown from peripheral blood of patients with other viral illnesses associated with circulating "atypical" lymphocytes. Glade and his associates and Stevens, et al. found that blood leukocytes from about half of patients with presumed viral hepatitis grew into HLCL.""' All patients in Glade's series had EBV antibody when their leukocytes were cultivated in vitro. Two of the lines established by Glade from hepatitis patients showed evidence of EBV. Minnefor and co-workers established longterm suspension cultures of leukocytes from patients with viral diseases such as herpes simplex, mumps, herpes zoster, and measles, but did not provide data about EBV antibody in their patients. ' Klemola, et al. found that in 3 of 12 adult patients with cytomegalovirus infection HLCL have been obtained from 6 months to several years after appearance of the clinical disease.' In few series has a large control group of normal individuals been studied in order to compare the frequency of formation of HLCL in a particular disease and in normals. Such information as is available, including results from our laboratory, suggests that when small inocula of cells (105_106 cells/ ml.) and small volumes of cells (10-20 ml.) are used, normal blood leukocytes do not spontaneously form HLCL. By contrast, white blood cells from patients with IM and from some patients with leukemia form lines readily under these conditions. However, under special conditions white blood cells from healthy individuals who possess EBV antibody can be grown as HLCL. Long-term cultures of leukocytes from normal individuals were first described by Moore" and later by Gerber and Monroe.' Both workers observed EBV in some of these cell lines. The experimental method in large part influences whether or not lymphocytes from normal persons can be grown as HLCL. Both Moore and Gerber and Monroe initiated normal blood cultures with white blood cells from 500 ml. of blood, and frequently adjusted the leukocyte concentration so that at least 5 X 105 viable cells/ml. were always present.
Several reports of serial attempts to cultivate HLCL are summarized in Table 1. HLCL have been derived from patients with a variety of diseases, malignant and benign, and under special cultural conditions from normals. The majority of such leukocyte suspension cultures have contained EB virus, and whenever it has been studied the donor of the leukocyte line has had detectable EBV antibodies. A reasonable general hypothesis under which to 362 Volume 43, June, 1971 E-B virus, a review M assemble these observations is that a very small number of cells with the capacity to divide continuously in vitro is present in the peripheral blood of normal individuals with EBV antibodies and that in diseases such as leukemia or IM the number of such cells competent to initiate DNA synthesis in vitro increases.
Significance of EBV "free" lines A line "free" of detectable EBV poses many interesting questions, such as "Was EBV initially responsible for its growth?" or "Is EBV present in the line in some form not detectable by our current limited assay techniques ?" Detection of EBV is difficult since viral particles or viral antigens are present in a small proportion of cells. Detection of virus by electronmicroscopy represents a serious sampling problem. In IF tests unwanted fluorescence in certain lines due to production of gamma globulins makes a low level of immunofluorescence difficult to interpret. Another problem in detection of EBV is the downward fluctuation with time in the level of immunofluorescent cells due to unknown causes.
A final answer to the question, "Do all HLCL contain at least part of the EBV genome?" must await development of more refined techniques to demonstrate presence of the viral genome. A recent study by Zur Hausen and co-workers,' employing techniques of nucleic acid hybridization, suggests that viral genome is present in some HLCL, such as the Raji line, which do not reveal particles or viral antigen. Zur Hausen and collaborators showed that the Raji line contained DNA with homology to purified EB viral DNA. Furthermore, in preliminary experiments they found an RNA in Raji cells which hybridized with EB viral DNA. This result suggests that at least part of the EB viral DNA in Raji cells is transcribed into RNA.
Characteristics of the EB virion-Morphological and biophysical EBV in electronmicrographs resembles herpes simplex virus, though it is smaller.'7 Encapsidated forms with or without an electron dense nucleoid are seen in the cell nucleus. The approximate diameter of the electron dense central nucleoid is 45 nm, and of the capsid plus nucleoid, 70 nm. Some enveloped forms are found in the cell cytoplasm, but rarely extracellularly. The diameter of the completed enveloped virion is approximately 115 nm. Most particles seen in an infected cell are imperfect; they either are unenveloped, or contain no nucleoid core; occasionally free nucleoids are seen. In early pictures of virus from Burkitt tumor cells, extracellular virions were enclosed in a hazy cloud of amorphous material, thought to be specific antibody coating since these early HLCL cultures contained human serum.
Cells harboring the herpes-like particles are usually degenerated, although occasionally particles are found in morphologically altered but intact cells. The nuclear membrane of virus-infected cells frequently shows segments of reduplication, a morphological sign of infection with many other herpes viruses. In addition, infected cells demonstrate collections of tubular structures located in the cytoplasm.'7 EBV particles were partially purified from infected cell lines by Toplin and Schidlovsky' who submitted homogenates of a large number of cells to rate zonal centrifugation. Several grossly visible bands were isolated that contained viral particles in various stages of maturation, similar to those present in thin sections of infected cells.
The DNA of EBV has been purified and its density determined.`6 Isotopically labelled virus was first isolated either from supernatant fluids or cell extracts by rate zonal centrifugation in sucrose gradients. The virus was then extracted further, and the labelled DNA was placed on an equilibrium buoyant density gradient of cesium chloride. In three laboratories the density of EB viral DNA was between 1.716 to 1.720 gm/cm.3 This value is similar to that obtained for herpes simplex DNA, and significantly different from cell DNA (1.695 gm/cm3). DNA of the density corresponding to that of EBV was not obtained when the Raji-line, free of EBV particles, was treated in parallel, although, as previously mentioned, EB viral DNA can be demonstrated in the Raji line by nucleic acid hybridization.
Assays for the presence of EBV Sensitive quantitative assays for the biologic activity of EBV, such as the plaque assay employed for other animal viruses, are not yet available. For this reason, little is known of the replicative cycle of the virus. However, several existing assays detect the presence of EBV.
Electronmicroscopy: Hinuma and co-workers' studied growth of EBV in a BL line by sampling the cells and supernatant fluids at intervals and counting particles by electronmicroscopy. Their results suggested that the majority of the virus was cell-bound but that some was released into the fluid phase of the culture as the cells were kept without refeeding. Intracellular EBV antigen: Assay for the virus was simplified by the finding that most adult human sera contained anti-viral antibodies detectable by the indirect IF test on cells previously subjected to acetone fixation.3' The frequency of fluorescent cells correlated with the number of cells containing viral particles in electron micrographs and certain lines without viral particles were also free of viral antigen by the IF test. Increased specificity of the IF test was achieved by preparation of anti-EBV sera in rabbits and conjugation of the sera with fluorescein isothiocyanate.' When individual cells were studied both by electronmicroscopy and by the IF test, cells which contained viral antigens also contained particles. The IF test is at present the most widely employed assay both for determination of EBV antibody levels in human sera and also for detection of the presence of EBV in various HLCL.
Membrane antigen: Another assay detects an antigen on the cell membrane of unfixed HLCL cells and is called the membrane immunofluorescence (MIF) test.' MIF antigen has been found on the surface of cells in HLCL derived from patients with Burkitt's lymphoma, IM, leukemia, and from normals. By contrast to the intracellular IF antigen, which has only been found in cells grown for a time in vitro, the MIF reaction can be demonstrated on cells taken directly from biopsy material as well as those grown in culture.
The MIF antigen is distinct from antigens responsible for leukocyte typing; it can be demonstrated by using a patient's own serum to test his own tumor cells.'7 The MIF reaction is probably due to more than a single new antigen at the cell surface.'M Evidence for multiple antigens comes from experiments in which sets of sera with MIF reactivity are compared for their capacity to block the MIF reaction of other sera.
The MIF antigen and the intracellular EBV antigen are distinct antigenantibody systems, for MIF antibody can be removed by absorption with whole cells from an HLCL; after absorption, antibody against intracellular antigen persists.5M In contrast to the low level of intracellular antigen, often as many as 50% of cells may contain surface antigens. However, there appears to be some correlation between the extent of the MIF reaction and the extent of IF staining for intracellular viral antigen in a given HLCL.' These results suggest that the extent of expression of the viral genome varies from one HLCL to another and that regulation of membrane antigen and of viral antigen may be coordinated to some extent.
The implication of studies to date is that the MIF detects an antigen coded by viral genome. However, this point has not been proved conclusively and the alternative, that it represents an "unmasked" cellular antigen, must be explored. ' Complement fixation (CF): Extracts of certain BL or leukemia cell lines contain antigens that fix complement in the presence of certain human and primate sera."' At least two CF antigens are present in EBV-infected HLCL."T One antigen (V antigen) is associated with viral particles; the other antigen (S or soluble antigen) is present in supernatant fluids from which virus has been sedimented by ultracentrifugation. The CF test appears to be specific for EBV, since positive sera do not fix complement with anti-gens prepared from normal human leukocytes, a variety of non-leukocytic tissue cultures, or antigens prepared from other herpes-group viruses.
Immunodiffusion: Precipitating antigens are found in highly concentrated preparations of aged cultures of the Jijoye line of BL lymphoblasts.' In further applications of this technique as many as three lines of reaction between various sera and the Jijoye line were found.' Agar gel immunodiffusion correlates well with the IF method on fixed cells, and with CF, for detection of EBV.' However, of the three methods, immunodiffusion is the least sensitive.
Biologic activity of EBV Two biologic properties of EBV can be studied in cell culture. First, materials containing EBV cause normal leukocytes to undergo transformation into continuous cell lines of lymphoblastoid character. Second, highly concentrated, partially purified preparations of EBV may superinfect HLCL that are initially devoid of EBV antigens.
Transformation of normal leukocytes into continuously growing cell lines by EBV was discovered by Henle and co-workers.' As a source of EBV, Henle used lethally x-irradiated cells of the BL Jijoye line, and as a source of normal leukocytes the peripheral blood white cells of infant girls. (The Jijoye line maintained a diploid male karyotype and thus the origin of cells growing in co-cultivation could be identified by examination of chromosomes.) After two to three weeks of co-cultivation of the x-irradiated Jijoye cells and the female leukocytes, in the presence of a human diploid fibroblast "feeder layer," lymphoblastoid cell lines developed. These lines had female sex chromosomes (thus were derived from the infant leukocytes) and contained EBV antigen. Under the conditions of the experiment, the xirradiated Jijoye cells in separate culture did not survive, nor did the female leukocytes. As a control, x-irradiated cells of the Raji BL line, without EBV antigen, were incapable of promoting continuous growth of normal leukocytes. Using a similar co-cultivation system, Miller and co-workers showed that a factor capable of inducing continuous growth of normal adult leukocytes was also present in the x-irradiated cells of an EBV-infected HLCL from a leukemic child.' Similarly a leukemic cell line without EBV antigen was incapable of inducing normal white blood cell transformation.' Further studies by Diehl and co-workers and by our laboratory with this system have shown that transformed normal leukocytes (TNL) are capable of inducing continuous growth of other normal leukocytes.m Since EBV antigen appears in the TNL, the hypothesis considered most likely is that the transformation results from infection of the normal leukocytes by EBV and alteration of the cell's growth regulation by the virus. This thesis is supported by the findings of J. H. Pope and his co-workers in Brisbane, Australia, who showed that cell-free filtrates prepared from extracts of a leukemic HLCL, containing EBV, were capable of inducing continuous growth of leukocytic cells from human fetal thymus or spleen.' Appropriate controls indicated that the fetal lymphocytes did not proliferate in the absence of filtrates containing EBV. Sera that contained EBV antibodies inhibited the transformation, and sera devoid of such antibodies had no effect.' Neutralization of EBV-induced transformation of adult leukocytes by immune sera has recently been demonstrated in our laboratory.' Gerber, et al. have found75 that EBV concentrated and purified from supernatant fluids of aged cultures induced continuous growth of leukocytes obtained from an adult who had no evidence of past experience with any member of the herpes group. The mechanisms of EBV-induced leukocyte transformation remain to be elucidated.
Extracts of infected HLCL have been placed in a wide variety of tissue culture systems and a large number of experimental animals, without consistent cytopathic or other effects.'7 In preliminary reports it appeared that EBV might be cytopathic for dog thymus cells' or that EBV-infected cells might cause an encephalitis in newborn thymectomized hamsters ;' however, these reports have not been confirmed.
Horoszewicz found that concentrated and purified virus obtained from the fluid phase of infected cell lines when transferred to other HLCL apparently devoid of EBV, produced IF antigen in the recipient cells.' Various cell lines free of antigen have been used as receptors for the virus.'-' It has not been resolved whether viral antigen that appears in the "negative" lines is due to the superinfecting agent or to reactivation of latent virus in the recipient line, although the former explanation appears most likely. The activity of virus preparations used to "superinfect" is very low (102 to 103 ID50/ml.) despite concentration of up to 1,000-fold in some instances; the reasons for this have not been adequately explained.
Superinfection of the Raji line with concentrated partially purified EBV forms the basis for another serologic test, called the early antigen assay.' When the superinfected Raji line is treated with certain normal human sera in an immunofluorescence assay a very small number of EBV-infected cells is detected (< 1%). By contrast, when sera of comparable anti-EBV titer from patients with BL or nasopharyngeal cancer and from some IM patients are used, a larger number of EBV-superinfected cells (as many as 50%o) are detected. The superinfected Raji cells are said to be "abortively infected" because the EBV infection does not spread in the culture. Sera from some patients detect this abortive or early antigen while sera from other persons such as convalescent IM patients or apparently healthy people do not detect the antigen.
Relationship of EBV genome to individual cells of HLCL
Viral particles or viral antigens detectable by the IF test are present in few cells of any HLCL, usually not more than 5%o and often less. The number of fluorescent cells in some HLCL can be increased by cultivation of the cells at 320 C.,' or by cultivation of the cells in a medium deficient in Larginine." No published information is available on the effect of other techniques that induce replication of temperate bacteriophage or that induce replication of SV40 in transformed cells such as x-ray, Mitomycin C, or cell fusion.
Several interpretations may be considered to explain the constant low level of EBV infection in HLCL. The first is that HLCL are "carrier cultures" for EBV; that is, a few infected cells in the culture produce virus that infects the other cells. The low level of infection is explained by the presence of interferon which may protect the cells." The second is that the cultures consist of two distinct populations of cells: EBV-infected and -uninfected; both populations give rise either to EBV-infected or -uninfected cells. These two schema each assume that a very small proportion of cells are actually infected at any one time. A third model, which has received experimental support recently,8`'t is that all cells in an EBV-infected culture contain viral genome but only a small proportion of cells spontaneously make viral particles or viral antigens. Experimental proof depended on methods for growing mass cultures of HLCL from isolated single cells. Single cell clones were derived from various HLCL, each of which contained approximately lgo of cells with viral antigen. The clones were treated with EBV anti-serum to neutralize any virus that might be present at the cell surface. Each clone tested showed evidence of EBV, thus suggesting that EBV in some form is associated with all the cells in the culture.
Are HLCL tumor cellsf
It has not yet been determined whether the cells that comprise a HLCL are tumor cells or whether they are "activated" normal lymphocytes. The question is difficult to resolve for definite morphologic, biologic, or biochemical markers among HLCL derived from normal blood, from patients with IM, and from patients with malignant lymphoma or leukemia have not been recognized. Attempts to study the problem of tumorigenicity has involved transplantation of HLCL into heterologous hosts, such as newborn ratse and newborn hamsters, which have been immunologically crippled with antilymphocyte serum."' After several passages in hamsters, the tumor cells retain human surface antigens. Whether heterotransplantation represents oncogenic potential or adaptation of the cells to an in vivo culture system is not yet clear.
SEROLOGIC AND EPIDEMIOLOGIC STUDY OF EBV INFECTIONS
Three aspects of the human immune response to EBV have been studied; namely, circulating antibodies to surface membrane antigens on intact virusinfected cells, cell mediated reactions and circulating antibodies to the virus per se or to virus-associated antigens.
Antibodies against surface antigens of HLCL have been found in sera of BL patients and IM patients.' In a single reported case of BL, membrane antibodies were examined sequentially. They were elevated during remission induced by chemotherapy, after which they fell to a low level before recurrence of the disease.' Whether recurrence was related to disappearance of the membrane antibodies is speculative. The actual biologic function of membrane antibodies is uncertain, and it is not known whether or not the membrane antibodies are cytotoxic in vivo.
Recently Fass and co-workers' found that some patients with BL developed delayed type hypersensitivity skin reactions to autologous tumor cell extracts. In only one of 12 patients was the skin test positive before treatment, but in 7 of 12 patients delayed cutaneous hypersensitivity to extracts of their own tumors was evident after clinical remission was induced by chemotherapy. In several patients who failed to improve with treatment, delayed skin reactions did not develop. The nature of the antigens responsible for the skin reaction is not known.
Very little published work concerns in vitro tests for cell-mediated immunity to EBV. Recently Steel and Hardy" and Junge, et al." reported that extracts of cell lines formed from the peripheral blood of patients with IM stimulate short-term DNA synthesis in primary cultures of lymphocytes from the same patient. The nature of this mitogenic factor is not clear but preliminary studies by Junge suggest that it is not virus, but has the characteristic of a membrane-bound antigen.
When serological methods for detection of EBV antibodies became available in the mid-1960's, it was of greatest interest to determine whether the presence of antibodies to EBV correlated with those disease states, specifically BL and leukemia, in which EBV could be frequently found in longterm leukocyte cultures. Some results from these early serologic surveys, done with various techniques, gave in general the same over-all picture, as illustrated by the accompanying Table 2. A high frequency of EBV was found with all methods in patients with BL. Similarly, nearly all sera of African, Chinese, and American patients with nasopharyngeal cancer con-369 MILLER tained EBV antibody. The frequency of antibody titers in sera of leukemia patients was much lower than in the other two diseases. A most surprising finding from initial studies was that antibody was widely distributed in the sera of healthy individuals, both African and American, although patients with BL and IM, and nasal tumor have usually had significantly higher antibody titers than normal individuals.
Age and geographic patterns of antibody
In a study of complement-fixing antibodies to EBV, Gerber' showed that the age-distribution was similar to the pattern observed for other acute viral diseases of childhood such as measles or poliomyelitis in the pre-vaccine era. Nearly all sera from newborn infants contained antibody, presumably maternal in origin. Less than 20% of sera from infants aged 6 months to 1 year contained antibody. With increasing age, the percentage of sera with antibody rose from 30%o in the 1 to 2 year group to more than 60% in the 3 to 5 year group. Porter and associates demonstrated a similar increase in the prevalence of EBV antibodies with increasing age. ' Henle and Henle have examined sera taken prospectively to determine whether the acquisition of antibody in the younger child was accompanied by an identifiable clinical illness such as "non-bacterial tonsillitis."" In most cases seroconversion to EBV was clinically silent.
The age at which antibody to EBV is acquired is influenced by geographic and by social factors. Eighty percent of the African children studied by Henle, et al.' possesed EBV by age 2, while a majority of 10 year old middle-class children from Cleveland, studied by the same workers, had no antibodies." In their studies of Yale college students, Niederman, Evans, and collaborators'-1' found approximately 60-75 o of freshmen to be susceptible to EBV. This figure, significantly higher than predicted by Gerber's earlier serologic survey using sera from low-income families, was attributed to the social-class background of college students. By contrast to their findings in Yale undergraduates, Niederman and co-workers found only 257%o of University of Philippines undergraduates without EBV antibodies.
Although large-scale geographic surveys have not yet been done, antibodies have been found in sera collected from several isolated primitive peoples from New Guinea, Micronesia, and South America." A most important point which has received preliminary study1' is the relationship between the distribution of Burkitt's tumor and the distribution of EBV antibodies. EBV antibodies are no more frequent in residents of the lowlands of Uganda where BL is endemic than in those living in other geographic areas where the tumor is much less frequent.
Relationship of EBV to infectious mononucleosis
In late 1967 Henle, Henle, and Diehl discovered a relationship between EBV and IM through observations during the illness of their laboratory assistant, Elaine H.' Elaine H.'s leukocytes, used as controls in experiments before she acquired IM, failed to proliferate for more than a short time. After IM, her leukocytes grew continuously and contained EBV. Her serum, free of EBV antibodies before her illness, contained EBV antibodies after her illness. A small series of pre-and post-IM sera obtained from Dr. Niederman at Yale, confirmed the observation that EBV antibodies were absent in pre-illness sera and present in sera taken after the illness. Also with Niederman's sera, Gerber and co-workers demonstrated with complement fixation that EBV antibodies were absent in pre-IM sera and that they appeared during the disease,1' while in the same paired sera no consistent response to herpes simplex, cytomegalovirus (CMV), or reovirus, was observed. Absorption of sera with sheep red blood cells had no effect on EBV antibodies, although heterophile antibodies were removed. Niederman and his collaborators'0' showed that EBV antibodies appeared during the clinical illness and persisted thereafter, while heterophile antibodies declined.
In an elegant epidemiologic analysis'0' made possible through a long-term prospective collection of sera, Evans, et al. showed that the absence of EBV antibody correlated well with susceptibility to IM, and conversely that college students who possessed EBV antibody at entrance did not develop IM. In this investigation they established that occasional cases of heterophilenegative IM were associated with antibody rises to EBV. Their data suggested, furthermore, that inapparent infection with EBV was considerably more frequent than clinical IM in persons younger than college-age, thus confirming the hypothesis proposed ten years earlier by Evans.' By contrast, in the college-age group clinical IM was approximately twice as frequent as inapparent infection with EBV. Other investigators have confirmed that EBV antibodies develop during clinical IM,'0 though they disagree about the significance of these antibodies. The complex question of their significance will be treated in the DISCUSSION.
Klemola and Kaariainen'7 found rising complement-fixation antibody titers to CMV in certain clinical cases of heterophile-negative cases resembling IM, but usually distinguished by the absence of sore throat and widespread lymphadenopathy. It was subsequently shown that CMV could frequently be isolated from these patients. Klemola, Von Essen, Henle, and Henle'0' recently studied 44 cases diagnosed as heterophile-negative IM.
Their results showed that CMV and EBV each cause some cases diagnosed 372 Volume 43, June, 1971 E-B virus, a rezJiew M as heterophile negative IM and that possibly other agents as well are responsible for a proportion of the cases.
Transmission of EBV infections
The route of transmission of EBV infections is in large part unresolved. It has been presumed that IM is transmitted by the oral or respiratory route but EBV has not been isolated from these sites. The failure to isolate EBV from the upper respiratory tract may reflect the insensitivity of available methods for cultivation of infectious virus. Attempts to isolate EBV from mosquito pools in Africa have not met with success. This also may be a matter of technique. There is no evidence of congenital EBV infection in the form of isolations of the virus from embryonic sites or from leukocytes of newborn infants. Limited data collected by the Henles in the Cleveland family study failed to detect individual infants whose maternal antibodies did not disappear.
Transmission of EBV through blood transfusion has been documented.'`m Gerber called attention to rising EBV antibody titers in five individuals of a large series of patients who were treated with multiple blood transfusions during and after open heart surgery. EBV was cultivated in the leukocytes of one patient who developed an illness similar to IM, with fever, atypical lymphocytes, and a positive heterophile test. Blacklow and co-workers studied a similar case of post-transfusion mononucleosis in a very elderly patient who ocquired an IM-like illness with heterophile antibodies five weeks after receiving three blood transfusions for a hip fracture. EBV was isolated from this patient and Ig-M anti-EBV antibodies were present in her acute phase serum. Henle and others showed in a large prospective series of patients receiving multiple blood transfusions for heart surgery, that of 18 without pre-operative antibodies, six acquired EBV antibodies, although none of the patients in this series developed illness clinically similar to IM. Parenteral transmission of the virus probably occurs in association with infected leukocytes in blood; however, other routes will have to be sought for transmission of the majority of EBV infections in which there is no evidence for parenteral exposure.
DISCUSSION
Intrinsic biologic interest of EBV EBV is in many ways a unique virus, and will undoubtedly continue to receive attention from those interested in the mechanisms of viral infections. Thus far it shows strict tropism for primate leukocytic cells of the lymphocytic series. Tropism for cells of certain species in vitro and in vivo have been long recognized as a property of animal viruses, for example, in the rather strict preference of poliovirus for primate cells. However, strict preference for one type of differentiated cell is a new phenomenon and deserves further analysis.
Another feature of EBV infection at the cellular and molecular levels of general biologic interest is the regulation of production of complete virus. In vivo viral particle production is repressed, but in vitro virus is produced. In cloned cell populations a few cells produce viral particles; most do not, even though all cells apparently contain viral genome. The control mechanisms, whether they reside in cell or virus, are closely regulated since approximately the same percentage of cells produce viral particles when the cells are examined at random over a long period of time. A study of the nature and mode of operation of repressors of virus synthesis in EBV infected cells may have general relevance to problems related to cell differentiation.
EBV causes changes in the morphology and growth characteristics of normal leukocytes. It is not yet known whether this phenomenon is analogous to "viral transformation" induced by polyoma virus and SV40, or whether it is a further stage of "blast transformation" produced by substances such as phytohemagglutinin or by specific antigens. The former explanation seems more likely at present than the latter. Whatever the explanation, it will be of great interest to know the details of the mechanism by which the normal lymphocyte with limited potential for in vitro growth is stimulated to grow continuously by EBV.
In many ways, except for their in vitro immortality, the lymphoblastic cells of HLCL resemble "dedifferentiated" lymphoblasts produced by phytohemagglutinin (PHA). Both PHA-treated cells' and HLCL spontaneously release interferon-like viral inhibitors."' Release of interferon may be related to the presence of viral or other inducers within the leukocytes, or the release of interferon may occur whenever certain lymphocytic cells are in the blast stage. The latter explanation does not account for the observation that various HLCL differ considerably in the amounts of interferon which they produce.' The availability of cell lines that continuously manufacture and secrete interferon should allow analysis of the biosynthetic pathways involved in interferon production. Similarly, the availability of a large variety of HLCL which release immunoglobulins spontaneously' should permit analysis of the mechanisms of biosynthesis of these important proteins. Specific antibody activity has not yet been assigned to the immunoglobulins synthesized in vitro by HLCL. There are two major hypotheses about the role of EBV in IM. The framework of the first hypothesis follows: EBV is mainly transmitted by the respiratory route. Infection in the young child is associated with either no clinical symptoms, mild febrile illness, or infrequently, IM. In older adolescents and in susceptible adults infection with EBV more frequently causes IM than inapparent infection. Heterophile-positive IM is accompanied by development of EBV antibodies. Antibodies against the complete virus persist for life, and whether they are acquired following IM or following inapparent infection, these antibodies protect against subsequent IM due to EBV. After infection the virus also probably persists in lymphoid cells for life.
Outlines of the second hypothesis may be summarized as follows: EBV is a ubiquitous virus with a predilection for lymphoid cells. Its mode of transmission is not known, but it may be congenitally acquired. It persists in lymphoid cells in defective form, perhaps as viral nucleic acid, only until lymphoid cells are transformed into blastic cells. In its defective form the virus stimulates either a very low level or no antibody. When lymphoblasts appear, due to one of many causes, complete virus proliferates and circulating antibodies to the virus are produced. According to the second hypothesis, EBV antibodies correlate with resistance to IM because they co-exist with antibodies for other agents which are truly responsible for the disease.
The available evidence favors the first hypothesis. The strongest link in the chain of evidence in favor of a causal role for EBV in IM is the demonstration by Niederman, Evans, and colleagues that absence of antibodies against EBV correlates with susceptibility to IM. The evidence is strengthened by the in vitro demonstration that EBV stimulates leukocyte proliferation, a basic pathologic change in IM. The reported cases of EBV infection and post-perfusion illness transmitted by blood, after a five-week incubation period, also favor a direct role of EBV in the IM syndrome. Experimental transmission of IM to patients with malignant disease has apparently been accomplished, although published details are few.' In general, the major elements lacking to fulfill Koch's postulates are experimental reproduction of disease in man or laboratory animals, and recovery of the organism from experimental disease. These requirements may be very difficult to achieve. For a variety of reasons, especially ethical, it may prove impossible to carry out experimental transmission studies in man. EBV may or may not be ultimately adaptable to an animal host. An objection to the hypothesis of direct causation is that EBV has not been recovered immediately from materials obtained from persons with the disease. It has only been found in leukocytes which have been cultured in vitro for several weeks. However, the intimacy of certain cell-virus relationships may require adjustments of the definition of "viral isolation," as recent experience with measles virus and subacute sclerosing panecephalitis has taught us.' The passenger theory very correctly indicates areas where information is lacking: there is nearly no data on the usual route of transmission of EB virus and no suitable animal model for study of the in vivo effects of EB virus. One observation central to the passenger virus thesis is the frequent association of EBV with a number of diseases, besides IM, in which there are either circulating atypical lymphocytes or tissue lymphoblasts. The thesis states that EBV proliferation occurs when such cells are present. However, available evidence suggests that atypical lymphocytes per se are not sufficient to activate EBV infection. McCollum and co-workers'7 studied serial serum specimens from children with experimental hepatitis, some of whom developed atypical lymphocytes in the blood. These sera did not show rising EBV antibody titers. In the recent study by Klemola, et al. on heterophilenegative IM,1' patients with CMV-induced IM did not show booster responses in EBV antibodies despite a significant number of atypical lymphocytes in the peripheral blood. Support for the second hypothesis would consist of demonstration of virus in the leukocytes of a significant number of fetuses or newborn infants who did not possess antibodies to EBV.
Does EBV cause Burkitt lymphomas, nasopharyngeal tumors or leukemia! EBV-infected HLCL can be derived from individuals with diverse diseases and from individuals without disease. There are at least three different explanations that may account for these facts. First, in some diseases EBV may play a causal role. Second, while causal in some diseases, in other instances the passenger virus theory may be correct; EBV finds an appropriate host cell in which to multiply with the appearance of lymphoblasts from other causes. Third, since any infection with EBV may lead to life-long viral persistence, the appearance of EBV in a given HLCL in vitro may merely reflect past experience with the virus as well as the relative ease with which the patient's lymphocytes can be grown in vitro.
An unresolved problem is how a single agent (or closely related agents?) might cause a malignant lymphoma (BL) in one population and a benign lymphoproliferative disease (IM) in another. Differences in viral strain, differences in route of transmission, or differences in host factors might account for the high frequency of BL in Africa and its low frequency (compared with IM) in America. Burkitt now suggests"8 that in some way the co-existence of EBV and malaria might account for the high prevalence of 376 Volume 43, June, 1971 BL in Africa. Epidemiologic evidence that might answer the question of whether BL is caused by EBV is still lacking. A large scale prospective serologic survey might determine for BL as it has for IM whether circulating antibodies are associated with protection from occurrence of the tumor. Some have proposed that the only epidemiologic technique which will determine whether BL is caused by EBV is mass vaccination in the epidemic area against EBV followed by surveillance for BL.' Patients with nasopharyngeal tumors have high antibody titers against EBV' and EBV has been found in lymphoid cell lines derived from the tumors."t The tumor, although worldwide, is most common in certain parts of Africa and Asia. It is not histologically a lymphoid tumor, but a carcinoma, heavily infiltrated with lymphoid cells. One might suppose that nasopharyngeal tumors call forth proliferation of lymphocytes in which EBV persists. The situation may be analagous in sarcoid, in which high EBV antibody titers have recently been recorded. ' Serologic studies have usually shown that leukemic children or leukemic adults have comparable frequency of antibody and comparable antibody titers to age-matched controls (see Table 2). However, data have not been presented to indicate whether the sera tested were obtained from patients under treatment with drugs that suppress the immune response. HLCL have been derived from many patients with acute and chronic leukemia. Some HLCL contain EBV particles and antigen, others have been free of EBV. With the demonstration that EBV-negative cells may still contain viral genome, it is still conceivable that EBV genetic material is associated with leukemia cell lines, but that, for some reason, virion formation does not proceed as well in leukemia cells as in cells from IM or BL. The coexistence of acute leukemia, EBV infection and clinical IM has recently been appreciated,' but the significance of this association remains to be determined. It appears that viral persistence, characteristic of the other members of the herpes group in man, herpes simplex virus, varicella-zoster virus, and cytomegalovirus, is also true for EBV. For example, although CMV may be excreted by many healthy newborn infants,"2 the role of this agent as a pathogen in a certain characteristic syndrome of congenital defects is not questioned. The pattern that emerges from the group of human viral infections due to herpes viruses is one of prolonged association of the host and virus with occasional production of disease.
Prospects for control of EBV infections
Before full-scale efforts to produce a vaccine or other control measures for EBV infection are undertaken, the question whether the virus is indeed a human tumor virus must first be clarified. The most likely source for this clarification will probably come from an animal system. Should evidence point conclusively to an oncogenic role of EBV, control in the form of vaccination with an attenuated virus might be considered.
Several difficulties are immediately apparent upon consideration of a vaccine against EBV infections of man. It is unlikely that a vaccine could be given to man in the form of infected intact and viable cells which might contain other unknown potential tumor viruses. Hence, one technical prerequisite for an EBV vaccine would be the production of significant amounts of extracellular virus that could be purified. Utilization of an EBV vaccine might be complicated by persistence of the vaccine virus and also, perhaps, by persistence of virulent virus. Persistence of vaccine virus has been a problem with the attenuated virus vaccine against Marek's disease.' Whether persistence of these viruses would result in harmful effects could only be learned by long-term surveillance of vaccinated individuals.
As remote and difficult as seems the potential for control of EBV by vaccination, other methods appear equally complicated. Burkitt tumor appears to be sensitive to chemotherapy with cyclophosphamide and longterm remissions have been reported, although drug resistance occurs.' The virus might be expected to be sensitive to 5' iododeoxyuridine, a drug which has been used to treat some infections with herpes simplex virus, but it might be anticipated that virucidal doses of the drug given systemically would be highly toxic. It seems unlikely that therapy with interferon or interferon inducers would be of benefit. Cytomegaloviruses, the subgroup of the herpes group of viruses most like EBV, are notably resistant to the action of interferon.' Some novel approach might succeed that involved selective detection and destruction of cells which have been transformed by EBV. One such method, recently proposed by Moolten and Cooperband' would involve administration of antibody against EBV-induced membrane antigens. If this antibody were also linked with a toxin capable of destroying cells (diphtheria toxin in Moolten's in vitro experiments) all cells with the new membrane antigen would be specifically eliminated. Another speculative approach which might be termed "endogenous oncolysis" would be to devise a method which would induce 100%o of EBV-transformed cells to undergo a lytic cycle of viral replication and thus destroy themselves.
NOTE:
The bibliography, chosen to illustrate specific facets of investigations of EBV, is by no means complete and was not compiled with the intention of indicating priority in any aspect of research. A number of important topics have been excluded altogether from the review, largely for lack of space. Such topics include the susceptibility of HLCL to superinfection with various viruses, the serologic cross-reactions among members of the human and animal herpes viruses, and chromosome abnormalities in HLCL.
I am grateful to Professor Dorothy M. Horstmann for a critical reading and to Mrs. Virginia Thompson and Miss Laurie Nicholson for help with the manuscript.
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v2
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2018-04-03T00:05:51.199Z
|
1971-06-01T00:00:00.000Z
|
8329179
|
s2ag/train
|
SURFACE IMMUNOGLOBULIN‐MOIETIES ON LYMPHOID CELLS *
A number of experimental results indicate that normal lymphoid cells synthesize and accumulate immunoglobulin structures on the cell surface that may be responsible for the recognition of antigens. Most of this evidence is provided by experiments in which anti-immunoglobulin antibodies are shown to react with the surface of lymphoid cells' and even to influence their iunction under certain experimental circumstancea.2~s These studies have enabled us to detect antigenic determinants located in the various parts of immunoglobulin molecules, but there is scanty additional information on their relationship to serum immunoglobulins and on their location in the surface membranes. In our studies, viable cells isolated from several Burkitt lymphomas and other lymphoid malignancies were shown to react with fluorescein-labeled anti-immunoglobulin sera.'.'' In all cases encountered the cells reacted with antibodies specific for the heavy chain of IgM ( f i ) and K light polypeptide chain. In the presence of complement, these antibodies were cytotoxic. Cells from such Burkitt lymphomas that have been kept in culture for more than a year have maintained the p and I( structures, proving that these are synthesized by the ceUs.l0 The ultrastructure of the cells was basically similar to that of lymphoblasts." When a number of lymphoid malignancies were surveyed it was observed that the strength of reactivity with anti-immunoglobulin sera varied among different patients.'.' As these cells may be regarded as a malignant clonal outgrowth of immunoglobulin-carrying normal lymphocytes maintaining their differentiation, they provide a good tool for studies on the properties of the immunoglobulin moiety itself and its relationship to the cell membrane. In the work presented in this paper an attempt was made to estimate the amount of cell membrane-bound immunoglobulin structures with special reference to two cell populations, T.P. chronic lymphocytic leukemia cells obtained
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v2
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2018-04-03T01:50:08.978Z
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1971-06-01T00:00:00.000Z
|
31100785
|
s2ag/train
|
DEMONSTRATION OF CELL‐SURFACE ANTIGENS ON CHEMICALLY INDUCED TUMORS *
Chemically induced tumors frequently possess new tumor-specific antigens, described as tumor-specific transplantation antigens (TSTAs) because of their capacity to elicit rejection responses against transplanted tumor cells in genetically compatible (syngeneic) hosts as well as in the autochthonous host.'-3 In the rat, hepatomas induced by aminoazo dyes' and diethylnitro~amine~ and sarcomas induced by 3-methyl~holanthrene~ are strongly immunogenic, as measured by the maximum number of tumor cells rejected in immunized syngeneic hosts. Other tumors, such as hepatomas and mammary carcinomas, induced by 2acetylaminofluorene are generally lacking in immunogenicity as defined by this criterion, and in the few examples where immunity could be induced this was weak, only low numbers of tumor cells being rejected by immunized rats?s7 Similarly, mammary carcinomas arising without deliberate inducement were not found to be consistently immunogenic, and, where demonstrable, the immunogenicity was much weaker than that of tumors induced by aminoazo dyes and polycyclic hydrocarbons.' These experimental tumor systems, in which the immunogenicity has been defined by transplantation studies, provide convenient models for the investigation of in uitm assay of tumor-specific antigens. This paper describes the application of membrane immunofluorescence tests with viable tumor cells in suspension for the detection of cell surface-expressed tumor-specific antigen on these tumor types. These procedures also make possible a study of normal cell-surface antigen modifications during neoplastic transformation.
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v2
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2018-04-03T04:58:08.672Z
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1971-06-01T00:00:00.000Z
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41078833
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s2ag/train
|
[An electron microscopic study of the human prostatic cancer: with special references to lysosomal system in prostatic cancer and to high dose estrogen effect upon prostatic cancer].
The fine structure of normal and neoplastic prostate before and after the administration of high dose estrogen, has been investigated by the electron histochemistry and the following results were obtained. 1) Acid phosphatase activity can be seen in the lysosomes, as well as in the granules, vesicles and vacuoles within the secretory vacuole, while no activity can be detected within the cisternae of the rough endoplasmic reticulum and Golgi apparatus. 2) Many lysosomes and large secondary lysosomes surrounded by the access of many lysosomes are seen in the normal prostatic and the well differentiated prostatic cancer cells. 3) The large lysosomes having the internal structure are observed in the prostatic cancer cells. 4) The number of usual lysosomes are decreased and the autophagic vacuoles and the residual bodies with the distinct internal structure of myelin are increased in number at the undifferentiated prostatic cancer cells. 5) The lysosomes and large secondary lysosomes surrounded by the access of many lysosomes are also found in the basal cells of the normal prostate. 6) The cytoplasmic vacuolization near lysosome is seen by the gradual release of lysosomal enzymes, and the secretory vacuole is formed. The lysosome itself decreases in its size, and is observed as a granule in the secretory vacuole. 7) For the secretory mechanism in the cells of normal prostate and prostatic cancer: 1) macroapocrine secretion, 2) microapocrine secretion and 3) secretion by reverse pinocytosis are observed. There are two processes in the extracellular secretion of acid phosphatase: 1) by the secretion of the reverse pinocytosis of secretory vacuole and 2) by the secretion of the macroapocrine in which the lysosomes are possesed. 8) Undemarcated granular and fibrillar components are seen in the nucleoli of undifferentiated prostatic cancer cells, and there is a relative increase of granular component. These nucleoli might be thought to be in active state in the production of cytoplasmic free ribosomes. 9) The early changes in the prostatic cancer cells after the administration of high dose of diethyl stilbesterol diphosphate is seen mainly in lysosomes. Namely the limiting membrane of lysosomes is.
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v2
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2018-04-03T02:06:59.225Z
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1971-06-05T00:00:00.000Z
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32239644
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s2ag/train
|
Oestrogens in oophorectomized women.
endothelial stimulant clearances were estimated by autologous plasma haemoglobin clearance' and were found to be increased in 6 out of 10 patients with acute leukaemia, 5 out of 11 patients with chronic leukaemia, and in 8 out of 13 cases of Hodgkin's disease. Corticosteroid therapy appeared to make no difference, but those who had depressed clearances had recently been treated with radiotherapy or nitrogen mustard. The results indicate that certain tumours themselves increase the functional state of the reticuloendothelial stimulant. Increased phagocytosis in patients with carcinomata has been described by Salky et al.2 using reticuloendothelial test lipid emulsion and in Hodgkin's disease by Sheagren et al.3-I am, etc. E. N. WARDLE Royal Victoria Infirmary, Newcastle upon Tyne
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v2
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2018-04-03T00:47:14.072Z
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1971-06-07T00:00:00.000Z
|
26583138
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s2ag/train
|
Antibody to Epstein-Barr virus in American patients with carcinoma of the nasopharynx.
Serum antibody to Epstein-Barr virus (EBV) was measured in 21 patients with nasopharyngeal carcinoma (NPC), in 3 patients with lymphoma in the nasopharynx, and in control groups. Fifteen of 21 (71.4%) of the NPC patients had high anti-EBV antibody titers ([unk]1:160), whereas only six of 140 (4.3%) had such titers in the combined control groups; the geometric mean titer (GMT) of the NPC patients was 1:239, compared with a GMT in the lymphoma patients of 1:20 and a GMT in the control groups of 1:29. The NPC patients were categorized by the histologic type of their tumors, but no relationship between tumor histologic type and antibody titer was discernible. The data support the concepts that EBV appears to be specifically associated with NPC (as well as with Burkitt's lymphoma and infectious mononucleosis) and that such a relationship may well be causal.
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v2
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2017-07-15T04:12:02.116Z
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1971-07-01T00:00:00.000Z
|
34319455
|
s2ag/train
|
Serological and structural properties of Mason-Pfizer monkey virus isolated from the mammary tumor of a Rhesus monkey.
We describe here serological and structural properties of a virus, Mason-Pfizer Monkey Virus (M-PMV), isolated from a simian mammary tumor. This virus is morphologically similar to the known oncogenic RNA viruses (oncornaviruses). It has a 60-70S RNA, and its replication is inhibited by actinomycin. Antisera prepared against the virus isolated by density-gradient centrifugation identify at least two viral structural antigens. Immunodiffusion studies show that this virus is serologically unrelated to three types of simian foamy viruses, visna virus, and the known oncornaviruses. Immunofluorescence reveals that the structural proteins of the virus are synthesized cytoplasmically. Although M-PMV productively infects human cells in vitro, serological analysis does not show the presence of M-PMV antigens in human neoplasia.
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v2
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2018-04-03T00:30:42.084Z
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1971-07-01T00:00:00.000Z
|
12342242
|
s2ag/train
|
Occurrence of malignancy in immunodeficiency diseases: A literature review
The incidence of malignancy in patients with primary immunodeficiencies is roughly 10,000 times that of the general age‐matched population. It is apparent from this review of the literature that each type of immunodeficiency has a distinctive constellation of malignancies associated with it. In light of recent studies demonstrating both immunologically aggressive lymphocytes and the presence of blocking antibodies in the blood of neuroblastoma patients, a major role for immunity in ontogenesis seems almost certain. The role of such antibodies in the formation of lymphoid malignancies, such as occur so frequently in patients with immunologic deficiencies who often do not produce antibodies of any type well, remains unclear.
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v2
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2018-04-03T00:37:12.606Z
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1971-07-01T00:00:00.000Z
|
13557275
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s2ag/train
|
Oral contraception. A review of reported physiological and pathological effects.
A critical review of the literature concerning physical psychological and pathological effects of oral contraceptive use is necessary. A small but increased risk of thromboembolism results from the use of oral contraceptives. Although the relationship of risk to estrogen dosage is unclear it would be wise to use lower dose compounds unless higher dosages are required for menstrual control. Oral contraceptives do lower glucose tolerance in intial months of use but these changes are only significant for women with latent diabetes. Women with a predisposition to diabetes should have at least postprandial blood sugar determination before beginning this contraceptive method. Hypertension may result from oral contraceptive use among some predisposed individuals. All patients should have their blood pressure checked regularly and oral contraceptive use discontinued if hypertension is detected. Only in women with an inherited or acquired defect in hepatic excretory function has a significant change in liver function been observed. No causal relationship has been established between the use of oral contraceptive and occlusion of cerebral or coronary arteries cancer ophthalmological problems or changes in adrenal or thyroid function. It is difficult to determine the relationship between oral contraception and headaches nervousness and depressions but if these symptoms are reported by the patient oral contraceptive use should be discontinued at least temporarily. Subsequent fertility is rarely altered by oral contraceptives. The benefits that oral contraceptives offer by providing a totally reliable method of contraception by removing the fear of pregnancy and by eliminating mechanical intervention in and interruption of sexual activity should be valued.(AUTHORS MODIFIED EZ)
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v2
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2018-04-03T00:50:01.502Z
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1971-07-01T00:00:00.000Z
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26659933
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s2ag/train
|
The fibrinolytic activity of bladder cancer.
Haruo Hisazumi Department of Urology, School of Medicine, Kanazawa University (Director: Prof. K. Kuroda) Patients with transitional cell carcinoma of the urinary bladder were subjected to the studies of plasminogen activator activity in urine (38 cases) and cancer cells (18 cases). Plasminogen activator in urine was extracted with 2 M potassium thiocyanate solution and the activity was measured by the fibrin plate method. The cancer cells were studied by the histochemical fibrin slide technique. The results obtained were as follows: 1. In 60. 5% of patients with bladder cancer, plasminogen activator activity in urine increased to a high level. Especially in a high malignant tumor group the increase was significant. 2. After surgical intervention (partial cystectomy or TURI), the plasminogen activator activity in urine decreased significantly. 3. The recurrence of bladder cancer was followed again by an increase of plasminogen activator activity. This would indicate that the plasminogen activator was released from the tumor into the urine. 4. Some of the cancer cells showed fibrinolytic activity on the fibrin slides, while the normal epithelial cells showed no activity. The number of cases showing fibrinolytic activity in the cells increased with the malignancy. However, the fibrinolytic activity may be in some aspect due to the artificial damage on the cells in making the preparations. Furthermore, the possible origin of the plasmiongen activator and its possible physiological functions are discussed.
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v2
|
2018-04-03T00:50:21.606Z
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1971-07-01T00:00:00.000Z
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26885146
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s2ag/train
|
Entrapment of the Popliteal Artery and its Management
From the Department of Vascular Surgery, Huron Road Hospital, Cleveland, Ohio 44112. Intermittent claudication of the lower limb is a common symptom complex in the middle aged or older patient and is predominantly due to arteriosclerosis obliterans. It is relatively rare in young people but may be caused by obstruction of the popliteal artery from trauma, tumor, inflammation, or embolism. If these disorders can be ruled out, as a cause of intermittent claudication in the first and second decades of life, the probability of a congenital anomaly in the course of the popliteal artery, &dquo;entrapment,&dquo; should be seriously considered. To date, only thirteen cases of popliteal entrapment have been reported in the English literature. T. P. Anderson Stuart, a medical student at Edinburgh, first described this anatomic abnormality in 1849. When given the assignment of dissecting a limb that had been amputated for gangrene associated with an aneurysm of the popliteal artery, he found that the popliteal artery looped medially around and beneath the medial head of the gastrocnemius muscle. Eighty years later, Hamming,3 at Leyden University, reported the same anomaly associated with arterial thrombosis in a 12-year-old Dutch boy who underwent thrombectomy combined with sectioning of the medial head of the gastrocnemius muscle. This anomalous relationship between the popliteal artery and the medial head of the gastrocnemius muscle was subsequently observed and delineated by others (Table I), however, the name, &dquo;popliteal artery entrapment syndrome&dquo; was coined by Love and Whelan6 in 1965. Rich and HugheS8 describe obstruction of both artery and vein by the medial head of the gastrocnemius muscle. The treatment of this condition varied from: (1) Transecting the tendon, (2) Endarterectomy and transecting the tendon, (3) Lumbar sympathectomy, endarterectomy, and transecting the tendon and, (4) Aneurysmorrhaphy with transection of the tendon. Because of the fascinating nature of this condition and the diverse methods of management, it was thought appropriate to present one of our cases and to submit a logical surgical approach for its treatment.
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v2
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2018-04-03T00:51:50.385Z
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1971-07-01T00:00:00.000Z
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26941495
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s2ag/train
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Collagenolytic Activity from Venom of the Rattlesnake Crotalus atrox 1
A specific collagenase from a vertebrate source was first demonstrated by Gross and Lapiere (1). Collagenase was subsequently found in the media from tissue cultures of a variety of normal animal tissues (2-7) as well as several human and animal tumors (8). Delaunay and co-workers (9) reported that solutions of Vipera aspis venom contained weak collagenolytic activity and Hadidian reported that venom from Agkistrodon piscivorus is known to liquefy gelatin (10). We have demonstrated that venom from four species of snakes contains collagenolytic activity. Also, venom from Crotalus atrox degrades mesenteric native collagen fibers during tissue cultures (11). This report describes further evidence that the collagenolytic activity from Crotalus atrox venom is due to a specific collagenase. Materials and Methods. Lyophilized venom from Crotalus atrox was purchased from Sigma Chemical Company, St. Louis, Missouri. Rat-tail collagen solutions were prepared by extraction with acetic acid according to the procedure of Bornstein (12). Three times reconstituted rat-skin collagens were prepared by the method of Piez, et al. (13). The purity and native state of collagen was established by resistance to trypsin digestion. Collagenase activity was determined by viscometry. Viscosity changes were measured in Ostwald viscosimeters with flow times for water ranging between 77 and 90 sec at 27°. The reaction mixture had a final volume of 7.0 ml and contained 3 mM Tris-HCl, pH 7.0, 3 mM CaCl2, rat-tail collagen adjusted to a final specific viscosity of approximately 8.0 or rat-skin collagen with a final collagen concentration of 0.2%, and venom at various concentrations. Samples to be electrophoresed were subjected to thermal denaturation at 45° for 10 min (15). Disc electrophoresis as modified by Reisfeld, et al. (16) for basic proteins and revised by Nagai (15) was used.
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v2
|
2018-04-03T02:25:16.514Z
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1971-07-01T00:00:00.000Z
|
33490407
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s2ag/train
|
DEFICIENCIES IN OUR PRESENT PROTOCOL FOR CHEMICAL EVALUATION AND POSSIBLE REMEDIES
At the end of the 60’s we were suddenly faced with reports that a number of chemicals we had been exposed to for years-in some instances, for decades-were hazardous substances. Some pesticides, most notably DDT, were found to have produced cancers in mice; the widely used agricultural fungicide Captan was reported both teratogenic and mutagenic; the artificial sweetener cyclamate or its metabolites showed evidence of inducing both bladder tumors and chromosome abnormalities in rats and of producing teratogenic effects in developing chicken embryos. In each instance, the chemical was found to cause toxicity; specifically, the effects were mutagenic, carcinogenic, or teratogenic. When substances in widespread use for a prolonged period are suddenly reported to present the possibility of a grave hazard to health, our first reaction generally is to rationalize that they mmt be safe if there have been no reports of adverse effects, and our next tendency is to ask questions about the conditions of the tests, for example, the species of test animal and the route of administration of the chemical, and suggest that almost any agent may be carcinogenic, teratogenic, or mutagenic when administered at extremely high levels. I t is usually pointed out that animal experiments may not be relevant to the target species, man. These criticisms, however, must be weighed against such considerations as (1) the characteristics of the effects produced by mutagenic, carcinogenic, or teratogenic (MCT) agents; (2) the sensitivity of animal models when it is necessary to extrapolate from a limited animal population to potential widespread use in the human population; (3) the steadily increasing exposure of our population to a variety of chemicals by routes other than ingestion; and (4) the deficiencies in monitoring the population for these types of toxicity.
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v2
|
2018-04-03T03:41:31.684Z
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1971-07-01T00:00:00.000Z
|
7595737
|
s2ag/train
|
Factors in prognosis of colon and rectal cancer
Early diagnosis is most important in the prognosis in colorectal cancer because the cause of cancer is unknown and an effective and practical large‐scale screening test, easily and cheaply carried out, is unavailable. If the diagnosis is made early, when the patient is asymptomatic, and prior to development of complications or when the lesion is precancerous, the disease almost always is localized and adequate treatment gives excellent results. However, if symptoms have been present for months or complications have developed prior to establishing the diagnosis (because of patient neglect in seeking advice or physician lack of tenacity in evaluating the patient's condition), or if surgical treatment has been inadequate, the prognosis is poor. Education of physicians and the public remains most important in improving results further. New knowledge or new modalities of treatment should result in improved prognosis not only in colorectal cancer but also in cancer of other anatomic sites.
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v2
|
2018-04-03T04:23:04.927Z
|
1971-07-01T00:00:00.000Z
|
21544433
|
s2ag/train
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METABOLISM OF ANTICANCER AGENTS IN MAN
The knowledge of the physiological disposition of anticancer agents is of importance in that (1) it may aid in the design of new agents, (2) specific anticancer agents can be recommended for patients whose other physiological processes are abnormal, e.g. those with impaired renal function, (3) a more rational use of the known anticancer agents with regard to route and frequency of administration and combination with other drugs (such as antibiotics, sedatives, and analgesics) can be made, and (4) specific anticancer drugs or specific moieties (combined with cytotoxic groups) may be recommended for specific neoplasms. A majority of the anticancer drugs used clinically are metabolized. TABLE 1 summarizes the anticancer agents metabolized by microsomal enzymes. These include cyclophosphamide-Cytoxan@-a drug used clinically in the treatment of lymphomas, the chronic leukemias, multiple myeloma, and various other solid tumors. The active metabolite(s) of Cytoxan are unknown, but the activation takes place in the hepatic microsomal enzymes.' Hepatic microsomes are also responsible for the S-and N-demethylation of the following anticancer agents: 6-methylthiopurine, nitrogen mustard, procarbazine, and pur~mycin.*-~ In addition, the hydroxylation of various steroids used in treating leukemia and various solid tumors is accomplished by liver microsomes.6 Several anticancer agents are metabolized by nonmicrosomal enzymes, as indicated in TABLE 2. Thus, both 6-mercaptopurine and the antifol dichloromethotrexate are hydroxylated,'*' the former by xanthine oxidase and the latter by aldehyde oxidase. Cytosine arabinoside is deaminated to an inactive and less toxic compound, uracil arabinoside; 5-fluorouracil is metabolized by enzymes in a manner analogous to that for uracil catabolism; procarbazine is metabolized by xanthine oxidase and aldehyde oxidase, i.e., the conversion of the aldehyde, p-formyl-N-isopropylbenzamide, to the acid, N-isopropyl terephthalamic acid; and the antineoplastic agent hydroxyurea is reduced t o urea.'-'* The metabolism of several other anticancer agents is known from in uivo studies in both animals and man (TABLE 3), but whether enzymatic processes are operative, and which ones, remains ~nkn0wn.l~ In addition, at least four of the anticancer drugs, including the widely used antifol methotrexate (MTX), are excreted mainly as the unchanged compound, especially in man13-15 (TABLE 4). I now wish to summarize, briefly some studies on the disposition in man of various agents, including methotrexate and dichloromethotrexate (DCM), cyclophosphamide, and l-(2-chloroethyl)-3-cyclohexyl-l-nitrosourea (CCNU), whenever possible alluding to the principles discussed in the introduction of this paper. TABLE 5 summarizes the data on the excretion of MTX-3H in the urine and stool in nine patients.I6 Following oral administration at 0.1 mglkg, 61-73% of the administered dose could be recovered in 48 hours. Similar or somewhat higher percentages of the drug could be recovered following i.v. administration at 0.1,1,5, and 10 mg/ kg. DEAE-cellulose column chromatography of the urine of
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v2
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2018-04-03T04:24:26.584Z
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1971-07-01T00:00:00.000Z
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25640029
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s2ag/train
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How do nurses feel about euthanasia and abortion?
Members of the faculty involved in a course for medical students on ethical and moral issues confronting American physicians at the University of Washington Medical School conducted a questionnaire survey on attitudes concerning these issues, particularly euthanasia and abortion several years ago. Since then (1966) the questionnaire has been answered by practicing physicians, medical school faculty in the clinical departments, graduate practicing nurses, beginning students of nursing, and first and fourth year medical students. In the original study of physicians we found that patients or their families often asked physicians not to preserve life, and that one third of 418 practicing and teaching physicians favored legal and social evolution toward euthanasia and abortion for selected patients (1). We then decided to find out if nurses had heard a similar number of requests for euthanasia, and if nurses would cooperate in the implementation of euthanasia and abortion if social mores permitted. In September 1968, a questionnaire was sent to each registered nurse and each licensed practical nurse at the University of Washington Hospital, a 300-bed teaching institution, and the Swedish Hospital Medical Center, a 450-bed community hospital. Responses unless otherwise specified. of registered nurses and licensed practical nurses were pooled and all are referred to as "nurses" throughout this paper. The questionnaire closely paralleled that distributed to the attending medical staffs of the two hospitals. The first group of questions concentrated on assessing nurses' experiences with requests from terminally ill patients and their family members to (a) omit such procedures and medications from the treatment regimen which probably would extend life-negative euthanasia-as discontinuation of intravenous feeding in a comatose patient with metastatic cancer, withholding antibiotics from a 90-yearold patient with pneumonia, or discontinuing transfusions after 15 or 20 units in a patient with cirrhosis of the liver from alcoholism who is bleeding from esophageal varices and still conscious, and (b) take actions or institute such procedures which probably would hasten death -positive euthanasia-as giving intravenous pentothal to a patient with metastatic, painful carcinoma. A terminally ill patient was defined as one in whom "death seems inevitable in days or weeks." Two additional questions focused upon the nurse's discomfort when the physician was, or was not. practicing negative euthanasia with a terminally ill patient.
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v2
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2018-04-03T05:07:55.520Z
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1971-07-01T00:00:00.000Z
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41637730
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s2orc/train
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Rectal cancer——to burn or not to burn
Increasingly, during the past year, physicians have asked my opinion on fulguration for cancer of the rectum. I have answered that such treatment may provide effective palliation for poor risk patients, or for senile, elderly patients who are unable to cope with a colos tomy. Because these doctors usually tell me that they are electively treating good risk, operable patients with this method, I have the most uncomfortable feeling that fulguration of operable rectal can cer is becoming more common, particu larly among those who do not do major surgery, and long before any solid data indicate that fulguration is as effective as abdominal-perineal resection. In the past twenty years, the five-year survival rates for patients undergoing abdominal-perineal resections have not improved very much. However, during this same period, improved survival rates for patients with cancer of the rec tum did parallel an increase in the num ber of resections performed. As the rates of resection leveled off, so did the increase in survival. Substitution of fulguration for resection at this time would seem to nullify the only demon strated improvement in the survival of patients with rectal cancer. The main arguments used to justify fulguration as a substitute for resection appear to be the following: (1) it avoids a colostomy; (2) the method can control the local tumor without a major operation and its complications; (3) fulguration of cancer produces an immune response that allows the body to handle the cancer more effectively; (4) if nodal metastases are present the results of resection are so poor that resection is not justified. I would answer these arguments with the following points: (1) There is no question that fulgura tion will avoid colostomy in the vast majority of patients, at least tempo rarily. For some patients, a colostomy is a catastrophe with which they cannot cope, although, in my experience, these patients represent a very small mi nority of those who have a permanent colostomy. Most patients adapt to their new situation when properly taught and encouraged and resume their normal activities. (2) When the tumor is relatively small and superficial, considerable evi dence indicates that it can be destroyed locally by fulguration, but does not as sure that lymph node metastases are not present. We have seen and treated sulficient numbers of patients who have previously had fulguration to know that it is not universally effective in con trolling the local tumor. It is indeed true that complications of abdominal-perineal resection, such as impotence and uri nary dysfunction, are avoided, although, as Dr. Madden' has described them, ful guration has its own complications. It is not an ambulatory outpatient proce dure by any means. (3) The statement that fulguration of rectal cancer in man produces an im mune reaction which controls the cancer is pure speculation. To date, I know of no direct evidence to support this hy pothesis. (4) It has been stated that the results of surgery for cancer of the distal rec tum, when lymph node metastases are present, are so poor that radical resec tion with a colostomy is not justified. At Memorial Hospital from 1957—1964, 193 patients with cancer of the rectum
Increasingly,
during the past year, physicians have asked my opinion on fulguration for cancer of the rectum. I have answered that such treatment may provide effective palliation for poor risk patients, or for senile, elderly patients who are unable to cope with a colos tomy. Because these doctors usually tell me that they are electively treating good risk, operable patients with this method, I have the most uncomfortable feeling that fulguration of operable rectal can cer is becoming more common, particu larly among those who do not do major surgery, and long before any solid data indicate that fulguration is as effective as abdominal-perineal resection. In the past twenty years, the five-year survival rates for patients undergoing abdominal-perineal resections have not improved very much. However, during this same period, improved survival rates for patients with cancer of the rec tum did parallel an increase in the num ber of resections performed. As the rates of resection leveled off, so did the increase in survival. Substitution of fulguration for resection at this time would seem to nullify the only demon strated improvement in the survival of patients with rectal cancer. The main arguments used to justify fulguration as a substitute for resection appear to be the following: (1) it avoids a colostomy; (2) the method can control the local tumor without a major operation and its complications; (3) fulguration of cancer produces an immune response that allows the body to handle the cancer more effectively; (4) if nodal metastases are present the results of resection are so poor that resection is not justified. I would answer these arguments with the following points: (1) There is no question that fulgura tion will avoid colostomy in the vast majority of patients, at least tempo rarily. For some patients, a colostomy is a catastrophe with which they cannot cope, although, in my experience, these patients represent a very small mi nority of those who have a permanent colostomy. Most patients adapt to their new situation when properly taught and encouraged and resume their normal activities.
(2) When the tumor is relatively small and superficial, considerable evi dence indicates that it can be destroyed locally by fulguration, but does not as sure that lymph node metastases are not present. We have seen and treated sulficient numbers of patients who have previously had fulguration to know that it is not universally effective in con trolling the local tumor. It is indeed true that complications of abdominal-perineal resection, such as impotence and uri nary dysfunction, are avoided, although, as Dr. Madden' has described them, ful guration has its own complications. It is not an ambulatory outpatient proce dure by any means.
(3) The statement that fulguration of rectal cancer in man produces an im mune reaction which controls the cancer is pure speculation. To date, I know of no direct evidence to support this hy pothesis.
(4) It has been stated that the results of surgery for cancer of the distal rec tum, when lymph node metastases are present, are so poor that radical resec tion with a colostomy is not justified. At Memorial Hospital from 1957â€"1964 data. Jackman's article concerned the treatment of cancer in polyps. In his article he specifically stated that fiat crater-like lesions with puckering or distortion were candidates for radical resection; that protuberant lesions were considered for fulguration. He also im plied that lack of mobility, puckering or rolling of edges and areas of firmness were indications for radical resection. Jackman's results have no relevance to the problem under discussion, clinically infiltrating adenocarcinoma of the rec tum.
While it may be scientifically impos sible to condemn the procedure until it has been given an adequate, well supervised trial, it is also impossible and morally unjustified to discard abdomi nal-perineal resection when fulguration is still in its trial run. It is distressing that our nationally respected, elder statesmen of surgery have been un willing to urge caution in this matter.
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