摘要:

The discovery of a specific association between nerve growth factor (NGF) and basal forebrain cholinergic neurons (BFCNs) marks the beginning of a new era of research into neurodegenerative diseases such as Alzheimer disease (AD). Degeneration of BFCNs appears to be one of the earliest and most prominent neuropathological features of a broad range of diseases of the human brain that give rise to loss of memory and dementia (including, in addition to Alzheimer disease, Parkinson disease, Lewy body dementia, progressive supranuclear palsy, dementia pugilistica, olivopontocerebellar atrophy, and Wernicke-Korsakoff syndrome). Selective localization of NGF receptors on BFCN, the relatively high levels of NGF mRNA in BFCN target areas, and numerous effects of exogenous NGF in vivo and in vitro provide overwhelming evidence that the structure and function of BFCNs in the adult brain are dependent on this molecule. The question then arises as to how this special relationship is disturbed in the diseased human brain? Initial investigations in AD have already indicated a normality of NGF mRNA and retention of receptors in the basal forebrain region. Interpretation of these results and the therapeutic relevance of NGF obviously depend upon future developments in understanding the role of NGF in the normal and pathological brain.

ISSN:0893-0341    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Diagnosis of probable Alzheimer disease (AD) is made by a combination of characteristic clinical findings, when normal laboratory studies reveal no structural or metabolic cause of the dementia. Definite diagnosis of AD, however, can only be made with brain tissue examination. PET scanning reveals parietotemporal decreases in cerebral blood flow (CBF) and glucose metabolism that differentiate AD from normal elderly and from multi-infarct dementia. Preliminary studies suggest that similar defects in CBF are detectable in single photon emission computed tomography (SPECT) in AD. Utilizing the iodinated ligand [123I] HIPDM ([123I] hydroxyiodobenzylpropanediamine), we studied 19 patients with probable AD of varying severity, with emphasis on mild cases, to assess the utility of SPECT as a diagnostic test in AD. Parietotemporal perfusion on SPECT was decreased unilaterally or bilaterally in 16 of 19 AD patients, similar to the defects reported with PET. The degree and extent of decreased CBF on SPECT correlated with AD severity. Strong correlations were obtained between decreases in computer-generated ratios of parietal to cerebellar activity and the level of cognitive function. SPECT was read as normal (on the radiographic film) by the nuclear medicine physician in all cases with Mini-Mental State (MMS) score > 24, and showed bilateral parietal perfusion deficits in only 1 of 4 patients with MMS between 22 and 24. Ten of 12 patients with MMS ≤21 had bilateral parietal abnormalities; the other 2 had unilateral perfusion defects. All patients with MMS < 15 were bilaterally abnormal. SPECT is less expensive and more widely available than PET, and may have an adjunctive role in diagnosis of AD and other dementias if utilized under the proper circumstances.

ISSN:0893-0341    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Substance P-like immunoreactivity was visualized by immunohistochemical methods in 20 postmortem brains: 6 senile, 4 presenile Alzheimer dementia (AD), 3 AD with interhemispheric asymmetric cortical atrophy, and 7 control cases. For all pathological cases, the SP-like immunoreactivity was significantly reduced in the neocortical areas and in the hippocampus. This contrasted with an enhanced SP-like immunoreactivity in the pallidum and the substantia nigra in AD brains and a more pronounced SP-like immunoreactivity in the more atrophic side in the asymmetrically atrophied brains.

ISSN:0893-0341    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

The ganglioside monoclonal antibody A2B5 has previously been used at the light microscopic level to label Alzhimer neurofibrillary tangles (NFTs). Light microscopic analysis, however, could not reveal whether the A2B5 antibody-labeled NFTs or membrane fragments associated with NFTs. Therefore, we used pre-embedding immunohistotochemical electron microscopy to examine A2B5 labeling of NFT. We found that the A2B5 antibody does indeed label a NFT antigen associated with the paired helical filament (PHF) structure, while no significant labeling of membranes or membrane fragments was observed. However, no clear periodicity of the immunogold label on the PHF was found.

ISSN:0893-0341    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Young normals, aged normals, and patients with early and advanced probable dementia of the Alzheimer type (DAT) were administered a facial recognition memory task. A continuous recognition paradigm was used, in which subjects were instructed to identify the repeated faces in an ongoing series of faces presented on a video monitor screen. A signal detection analysis of the data revealed that the DAT patients were markedly impaired in their ability to discriminate between new and repeated faces. Multiple presentations of faces improved the recognition accuracy of the early DAT patients only, but their rate of learning was slower than that of the normal subjects. In comparison to the young normals, elderly normals exhibited a mild deficit in recognition memory. All of the elderly subject groups exhibited a more liberal response bias than the young normals, which eliminates the possibility that the impaired memory task performance of the aged subjects could be attributed to a more conservative test-taking strategy. The DAT patients exhibited impaired recognition even when the second presentation of a face immediately followed the first, which perhaps implies that task performance was also sensitive to the effect of DAT on visuoperceptual abilities or psychomotor speed.

ISSN:0893-0341    

出版商:OVID    

年代:1990

数据来源: OVID

ISSN:0893-0341    

出版商:OVID    

年代:1990

数据来源: OVID

ISSN:0893-0341    

出版商:OVID    

年代:1990

数据来源: OVID

ISSN:0893-0341    

出版商:OVID    

年代:1990

数据来源: OVID

ISSN:0893-0341    

出版商:OVID    

年代:1990

数据来源: OVID