She has a history of a positive PPD with a negative chest x- ray.
 The patient has a positive PPD.
(ROOT (S (NP (PRP She)) (VP (VBZ has) (NP (NP (DT a) (NN history)) (PP (IN of) (NP (DT a) (JJ positive) (NN PPD)))) (PP (IN with) (NP (NP (DT a) (JJ negative) (NN chest) (NN x)) (: -) (NP (NN ray))))) (. .)))
(ROOT (S (NP (DT The) (NN patient)) (VP (VBZ has) (NP (DT a) (JJ positive) (NN PPD))) (. .)))
( She ( ( ( has ( ( a history ) ( of ( a ( positive PPD ) ) ) ) ) ( with ( ( ( a ( negative ( chest x ) ) ) - ) ray ) ) ) . ) )
( ( The patient ) ( ( has ( a ( positive PPD ) ) ) . ) )