(S (S (NP (BASENP (NN Analysis)) (PP (IN of) (BASENP (JJ postmortem) (NN brain) (NN tissue)))) (VP (ADVP (RB also)) (VP (VBD revealed) (SBAR (IN that) (S (BASENP (DT the) (NNS proteins)) (VP (VP (VBP are) (RB n't)) (VP (VBN produced) (PP (IN at) (NP (BASENP (JJ normal) (NNS levels)) (PP (IN in) (NP (BASENP (JJ human) (NNP Alzheimer) (POS 's)) (NNS sufferers)))))))))))) (PERIOD .))