John P. Blass

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Reductions in cerebral metabolism sufficient to impair cognition in normal individuals also occur in Alzheimer's disease (AD). The degree of clinical disability in AD correlates closely to the magnitude of the reduction in brain metabolism. Therefore, we tested whether impairments in tricarboxylic acid (TCA) cycle enzymes of mitochondria correlate with(More)
A report of cell loss in the nucleus basalis of Meynert in patients with Wernicke-Korsakoff disease prompted the examination of thiamine pyrophosphate (TPP)-dependent enzymes in the brain and peripheral tissues of patients with Alzheimer's disease. In these brains, the activities of the 2-ketoglutarate dehydrogenase complex were reduced more than 75% and(More)
The activity of the pyruvate dehydrogenase complex (PDHC) was reduced in affected areas of brain from patients with Huntington disease (caudate, putamen) and Alzheimer disease (frontal cortex) where choline acetyltransferase (CAT) activity was low. PDHC was also deficient in an area (Huntington hippocampus) where CAT was not significantly reduced. The(More)
Glutamate dehydrogenase (GDH) is primarily a mitochondrial enzyme involved in the metabolism of glutamate. We have recently shown by light microscopic immunocytochemistry that, within detergent-permeabilized brain tissue, GDH is enriched in glial cells, particularly in regions utilizing L-glutamate as a neurotransmitter. In this study, we used immunogold(More)
Abundant evidence, including critical information gathered by Prof. Siegfried Hoyer and his colleagues, indicates that abnormalities of cerebral metabolism are common in neurodegenerative diseases, including Alzheimer's Disease (AD). Alterations in mitochondrial enzymes likely underlie these deficits. Replicable reductions in AD brain occur in the pyruvate(More)
The principally mitochondrial enzyme glutamate dehydrogenase (GDH) exhibited low-intensity, uniform immunoreactivity in neurons and intense heterogeneous labeling of glial cells of rat brain. Simultaneous peroxidase labeling for GDH and immunoautoradiography for glial fibrillary acidic protein (GFAP) confirmed the astrocytic localization of the enzyme.(More)
A variety of chronic, relatively low-grade injuries to the brain occur in Alzheimer's disease (AD). The extent to which each of these contributes to the clinical syndrome is unclear. Several of the abnormalities that occur in AD brain can cause dementia by themselves, even in people who do not have the neuropathological hallmarks of AD. Prominent among(More)
To determine the prevalence of unrecognized brain dysfunction accompanying chronic severe cardiac disease, we examined 20 clinically stable consecutive admissions to a cardiac rehabilitation service who were free of known stroke or dementia. Age range was 47 to 85 years (mean +/- SEM, 72.5 +/- 2.1 years), the male: female ratio was 10:10. Multiple cognitive(More)
A patient with an intermittent movement disorder has been found to have an inherited defect in pyruvate decarboxylase ((2-oxo-acid carboxy-lyase, E.C. 4.1.1.1.). The patient is a 9 yr old boy who since infancy has had repeated episodes of a combined cerebellar and choreoathetoid movement disorder. He has an elevated level of pyruvic acid in his blood, an(More)
Alterations in amyloid precursor protein (APP) metabolism, calcium regulation, oxidative metabolism, and transduction systems have been implicated in Alzheimer's disease (AD). Limitations to the use of postmortem brain for examining molecular mechanisms underscore the need to develop a human tissue model representative of the pathophysiological processes(More)