Faculty Bibliography

The aim of this study of the cerebral cortex of 8 non-demented elderly subjects and of 17 subjects in the severe stage of Alzheimer's disease (AD) (Global Deterioration Scale stage 7/Functional Assessment Staging procedure stage 7a-f) was to examine the relationships between amyloid-beta (Abeta) deposits and neurofibrillary degeneration. The study shows that neuronal processes with neurofibrillary changes are detectable in only a minority of fibrillar plaques: from 31% to 49% of fibrillar plaques within frontal, temporal, parietal, limbic, occipital, and insular cortices. The correlations observed between the numerical densities of neurons with neurofibrillary tangles (NFTs) and the densities of Thioflavin-S-positive fibrillar plaques with neurofibrillary changes (r=0.61; P<0.01) indicate that neurofibrillary pathology in neocortical plaques reflects the topography and rate of neurofibrillary changes in neocortical neurons. The accumulation of abnormally phosphorylated tau in only some plaques indicates that fibrillar Abeta enhances paired helical filament accumulation locally only in dystrophic neurites already involved in neurofibrillary degeneration. The lack of correlation between the number of neurons with neurofibrillary changes and the number of all Thioflavin-S-positive fibrillar plaques (with and without neurofibrillary changes) suggests that beta-amyloidosis does not contribute to initiation of neurofibrillary degeneration in neurons

Inheritance of apoE4 is a strong risk factor for the development of late-onset sporadic Alzheimer's disease (AD). Several lines of evidence suggest that apoE4 binds to the Alzheimer Abeta protein and, under certain experimental conditions, promotes formation of beta-sheet structures and amyloid fibrils. Deposition of amyloid fibrils is a critical step in the development of AD. We report here that addition of melatonin to Abeta in the presence of apoE resulted in a potent isoform-specific inhibition of fibril formation, the extent of which was far greater than that of the inhibition produced by melatonin alone. This effect was structure-dependent and unrelated to the antioxidant properties of melatonin, since it could be reproduced neither with the structurally related indole N-acetyl-5-hydroxytryptamine nor with the antioxidants ascorbate, alpha-tocophenol, and PBN. The enhanced inhibitory effects of melatonin and apoE were lost when bovine serum albumin was substituted for apoE. In addition, Abeta in combination with apoE was highly neurotoxic (apoE4 > apoE3) to neuronal cells in culture, and this activity was also prevented by melatonin. These findings suggest that reductions in brain melatonin, which occur during aging, may contribute to a proamyloidogenic microenvironment in the aging brain

It is truly a great pleasure to have this special issue of the Journal of Alzheimer's Disease in the memory of Henry M. Wisniewski, who was one of the most well-known scientists in the field of Alzheimer's disease and animal models. We are very grateful that so many of Henry Wisnewski's colleagues, who are all accomplished Alzheimer disease researchers, have written articles for this memorial issue.

We describe a Polish family with Alzheimer's disease in some of its members. Two sisters were observed and examined--also neuropathologically in the Institute of Psychiatry and Neurology in Warsaw. The disease onset was in our patients at 32 and 33 years. The first symptoms were memory loss and disorientation. Later on myoclonus and extrapyramidal stiffness were noted in both cases. Neurovisualizing examinations performed in both sisters showed diffuse brain atrophy. The symptoms increased rapidly and in short time (several months) the patients became mute and bedbound. They died at age 35 and 37 years. We were informed that the father of the patients suffered from very similar illness and died at age of 37 years and their older brother had the some symptoms and died at the age of 28 years. Post-mortem brain examination disclosed in the both hospitalized cases diffuse atrophy of the cerebral hemispheres, particularly severe in the temporal lobes. Microscopically senile plaques of various types were found in the cortex. The density of the plaques was very high but Alzheimer's fibrillary degeneration was found occasionally only. The amyloid burden in cortex of the examined brains, estimated as the measure of parenchymal amyloidosis beta, was two to six-fold higher in most areas compared with changes in sporadic AD and Down-syndrome cases. DNA was isolated from blood and tissue of both cases and from blood of their 8 children as well. In both patients mutation in presenilin 1 (PS1) gene of Prol 117 Leu was found and it was discovered that 4 persons of their progeniture were carriers of this mutation. The described mutation causes one of the earliest so far reported onset and death in FAD kindreds. Presenilin isolated from both cases and transfected into cultures of murine neuroblastoma and human kidneys provoked production of beta amyloid with increased A-beta 42/40 ratio

The cerebral deposition of amyloid beta-peptide, a central event in Alzheimer's disease (AD) pathogenesis, begins several years before the onset of clinical symptoms. Non-invasive detection of AD pathology at this initial stage would facilitate intervention and enhance treatment success. Here, we demonstrate the ability of high field strength MRI to detect regional brain volume reductions and ventricular enlargement in the PS-APP transgenic mouse model of AD more sensitively than histopathologic analysis by unbiased stereology. Moreover, the transverse relaxation time T2, an intrinsic MR parameter thought to reflect impaired cell physiology, was altered substantially in cortical regions containing beta-amyloid but only slightly in cerebellum, which contains little beta-amyloid. MR measures were also minimally altered in mice expressing mutant presenilin-1, which do not deposit beta-amyloid, supporting the view that the MR abnormalities in PS-APP mice are partly related to amyloid beta-peptide deposition. These results set the stage for MRI to aid in the early diagnosis of AD and the evaluation of potential therapies in transgenic animal models and in patients