( ( Staining ( of ( lung ( tissue specimens ) ) ) ) ( ( ( is sometimes ) ( needed ( to ( definitively ( ( ( diagnose ( ( PCP pneumonia ) ( in ( non-HIV ( infected ( immunocompromised patients ) ) ) ) ) ) , ) ( since ( ( ( they ( have ( ( a ( smaller ( PCP ( cyst load ) ) ) ) ( in ( the alveolus ) ) ) ) ) and ) ( infection ( may ( be ( missed ( by ( ( only ( performing stains ) ) ( on ( BAL fluid ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NN Staining)) (PP (IN of) (NP (NN lung) (NN tissue) (NNS specimens)))) (VP (VBZ is) (ADVP (RB sometimes)) (VP (VBN needed) (S (VP (TO to) (VP (ADVP (RB definitively)) (VB diagnose) (NP (NP (NNP PCP) (NNP pneumonia)) (PP (IN in) (NP (JJ non-HIV) (JJ infected) (JJ immunocompromised) (NNS patients)))) (, ,) (SBAR (IN since) (S (S (NP (PRP they)) (VP (VBP have) (NP (NP (DT a) (JJR smaller) (NNP PCP) (JJ cyst) (NN load)) (PP (IN in) (NP (DT the) (NNS alveolus)))))) (CC and) (S (NP (NN infection)) (VP (MD may) (VP (VB be) (VP (VBN missed) (PP (IN by) (NP (NP (RB only) (VBG performing) (NNS stains)) (PP (IN on) (NP (NNP BAL) (NN fluid)))))))))))))))) (. .)))
Staining of lung tissue specimens is sometimes needed to definitively diagnose PCP pneumonia in non-HIV infected immunocompromised patients, since they have a smaller PCP cyst load in the alveolus and infection may be missed by only performing stains on BAL fluid.
(ROOT (S (NP (DT The) (NN term) (NN pneumonia)) (VP (VBZ is) (NP (NP (DT the) (NN name)) (PP (IN of) (NP (NP (DT the) (NN disease)) (SBAR (WHADVP (WRB where)) (S (NP (NP (DT some)) (PP (IN of) (NP (NP (DT the) (NNS alveoli)) (PP (IN of) (NP (DT the) (NNS lungs)))))) (VP (VBP fill) (PP (IN with) (NP (NN fluid))) (SBAR (IN so) (S (NP (PRP they)) (VP (MD can) (ADVP (RB no) (RB longer)) (VP (VB exchange) (NP (NN gas))))))))))))) (. .)))