Protein-Rich Cytoplasmic Bodies of Substantia Nigra and Locus Ceruleus: A Comparative Study in Parkinsonian and Normal Brain

A histochemical study of substantia nigra and locus ceruleus from postmortem brains showed the presence of small spherical cytoplasmic bodies stained selectively by the anionic phosphotungstic acid-hematoxylin (PTAH) stain at a pH of 2.5. The metachromatic reaction to PTAH indicates that these protein bodies contain a protein rich in free basic amino groups. The protein bodies are localized within the neuronal perikaryon as well as in their dendritic processes. These bodies abundantly present in the substantia nigra and locus ceruleus of normal brains were noticeably reduced or absent in parkinsonian brains. Lewy bodies when present show that their core gives the same metachromatic reaction to PTAH as do the protein bodies. These findings suggest that an abnormality of protein synthesis in the substantia nigra and locus ceruleus of parkinsonian brains may be related to the absence of protein bodies and the formation of Lewy bodies and play a role in pathogenesis of the parkinsonian state. © 1978, American Medical Association. All rights reserved

Biochemical Assay of Alzheimer's Disease: Associated Protein(s) in Human Brain Tissue

The concentration of Alzheimer's disease—associated protein (ADAP) was measured in postmortem brain tissue samples of temporal or frontal cortex from 111 human brains using a sandwich immunoassay. Alzheimer's disease—associated protein has three major ALZ-50—reactive subunits, including A-68. This assay utilizes ALZ-50 and a rabbit antibody raised against a highly ADAP-enriched brain protein fraction. The frequently observed cross-reactivity of ALZ-50 with normal brain components in direct immunoassays is minimized by this configuration. There were 27 normal controls, 28 neurologic disease controls, and 56 Alzheimer's disease cases. The normal control and neurologic disease control cases had essentially no detectable level of ADAP, while ADAP was clearly detected in 85.7% of the Alzheimer's disease cases. Clinical dementia, neuritic plaques, and old age per se are not correlated with increased ADAP levels. This biochemical assay of ADAP may prove to be helpful as an adjunct in the clinicopathologic diagnosis of Alzheimer's disease.(JAMA. 1990;263:2907-2910