Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The diagnosis of Alzheimer's disease (AD) neurodegeneration is based on histopathological detection of paired helical filament-associated lesions. Silver stains are routinely used but the results are fraught with intra- and interinstitutional variability. This study employed monoclonal antibodies to middle and high molecular weight neurofilament subunits in an immunohistochemical assay to assess the extent of paired helical filament-associated lesions in brains with AD, Down's syndrome plus AD lesions (AD+DN), Parkinson's disease dementia (PD), AD+PD, and normal aging changes. The densities of neurofilament-immunoreactive (NFI) cortical neurofibrillary tangles and plaques were significantly higher in AD and AD+DN than in PD and aged control brains (p < 0.001), and NFI neurofibrillary tangles and plaques were more abundant in AD and AD+DN compared with AD+PD and PD, yet all patients with AD, AD+PD, or PD died with end-stage dementia. In contrast, the densities of NFI dystrophic neurites (primarily dendrites) in cortical Layer 2 were similar among the AD, AD+DN, AD+PD, and PD groups, and all were significantly higher than control (p < 0.005). Stepwise multivariate regression analysis demonstrated significant correlations between AD diagnosis and high densities of NFI neurofibrillary tangles and plaques (p < 0.001) and between end-stage AD-type dementia and high densities of NFI dystrophic neurites (p < 0.001). This study demonstrates that the histopathological lesions correlated with AD dementia can be readily detected and quantified by immunostaining with monoclonal antibodies to phosphorylated and non-phosphorylated neurofilaments. Moreover, the findings suggest that NFI neurite pathology may be an important feature contributing to the clinically manifested AD-type dementia in individuals with Parkinson's disease.
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PMID:Diagnostic utility of quantitating neurofilament-immunoreactive Alzheimer's disease lesions. 798 63

Oxidants are ubiquitous in our aerobic environment and could play an etiological role in aging and neurodegenerative diseases such as Alzheimer's disease. All cells contain several antioxidant enzymes, most importantly, superoxide dismutases (MnSOD and CuZnSOD), glutathione peroxidase (GSH-Px), glutathione reductase and catalase. The individual contribution of these antioxidant enzymes in neuronal protection during aging and under in vivo conditions remains unknown. We feel that the use of genetic manipulations to construct cells and/or transgenic mice that specifically overexpress or lack a single function represent a way to an understanding of the role of the individual antioxidant enzymes in neuronal aging. Copper-zinc superoxide dismutase (CuZnSOD) is one of the genes encoded by chromosome 21. As a consequence of gene dosage excess, CuZnSOD activity and protein are increased by 50% in all tissues of Down syndrome (DS) patients. It has been suggested that this increment, by accelerating hydrogen peroxide formation, might promote oxidative damage within DS cells and might be involved in the various neurobiological abnormalities found in DS such as premature aging and Alzheimer-type neurological lesions. Moreover, the level of CuZnSOD protein and mRNA is particularly high in pyramidal hippocampal neurons susceptible to degenerative processes in Alzheimer's disease, and in dopaminergic melanized-neurons vulnerable in Parkinson's disease. In order to test this hypothesis, we have created transfected cells and transgenic mice which express human CuZnSOD gene. An oversupply of this enzyme is not beneficial to the brain of transgenic mice and causes increased thiobarbituric-reactive substances (TBARS), an index of lipid peroxidation, and may be due to peroxides generated by an imbalance between enzymatic activities of CuZnSOD and GSH-Px. Unlike what has been observed in transfected cells with the human CuZnSOD gene, but similar to what was found in the DS fetal brain, the GSH-Px activity was not increased in the brain of transgenic mice. One possibility to explain this discrepancy could be the differential cellular localization of these two enzymes in the brain (CuZnSOD in neurons and GSH-Px in glial cells). This heterogeneous cellular distribution of the enzymes implicated in oxygen-free radicals detoxification could participate to a selective neuronal degeneration. Interestingly, overexpression of CuZnSOD in the brain of transgenic mice is associated with an increased MnSOD activity, the mitochondrial form of the enzyme. This increased MnSOD might be a defense response to protect mitochondria from oxidative damage.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Transgenic mice overexpressing copper-zinc superoxide dismutase: a model for the study of radical mechanisms and aging]. 801 10

Although familial factors in Alzheimer's disease (AD) are well established, uniform family-history assessment in genetic and epidemiologic studies of AD is needed to reconcile the divergent estimates of the cumulative risk of this illness among relatives of AD probands. To answer the need, the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) has developed a standardized Family History Assessment of AD to identify the presence of AD, Parkinson's disease (PD), and Down's syndrome (DS) in family members. This paper describes the use of this new assessment instrument in 118 patients with AD (estimated mean age at onset [+/- SD] = 64.5 +/- 7.7 years) and their nondemented spouses who were enrolled in 11 different CERAD sites in the U.S. The first-degree relatives of the probands with AD had a significantly greater cumulative risk (p < 0.005) of AD or primary progressive dementia (24.8%) than did the relatives of spouse controls (15.2%). Furthermore, the cumulative risk for this disorder among female relatives of probands was significantly greater than that among male relatives. There were no differences between the families of probands and controls for the numbers of affected first-degree relatives with PD or DS. This is the first reported multicenter family-history study of AD, and it supports earlier reports of familial factors in AD and indicates a higher risk to female relatives of AD probands. The CERAD Family History Assessment instrument may be useful for further multicenter and epidemiologic studies designed to delineate familial factors associated with AD.
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PMID:The Consortium to Establish a Registry for Alzheimer's Disease (CERAD). Part VI. Family history assessment: a multicenter study of first-degree relatives of Alzheimer's disease probands and nondemented spouse controls. 803 25

Both prevalence and incidence of AD increase steeply with advancing age in all populations investigated thus far. In general, women have higher prevalence and incidence; however, there are exceptions to this pattern. When considering only methodologically comparable surveys, and taking age into account, there are no major geographic differences in either prevalence or incidence. Data on incidence are unfortunately limited worldwide. There are no major time trends in either prevalence or incidence. The only definite risk factors for AD are age and familial aggregation. Putative risk factors are familial aggregation of Down's syndrome, familial aggregation of Parkinson's disease, late maternal age, head trauma, history of depression, and history of hypothyroidism. Cigarette smoking was found to be less common in the history of patients with AD than in that of controls. This association is probably spurious, however. Unfortunately, current knowledge about risk factors for AD does not justify the conduct of preventive trials or the introduction of large-scale interventions.
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PMID:Frequency, distribution, and risk factors for Alzheimer's disease. 812 14

Almost all Down's syndrome (DS) patients over the age of 35 to 40 years have histologic features of Alzheimer's disease (AD). However, the presence of extrapyramidal features in up to 36% of these patients has no satisfactory pathologic explanation. We report an older patient with DS, dementia, and parkinsonian signs who showed pathologic changes of Parkinson's disease and cortical Lewy bodies in addition to AD. These parkinsonian changes may be related to chromosome 21 abnormalities.
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PMID:A case of Down's syndrome with diffuse Lewy body disease and Alzheimer's disease. 799 Nov 52

Superoxide dismutase (SOD) plays an important role in the protection of cells against the deleterious effects of free radicals by dismutating the toxic superoxide anion radical. Although oxygen-based radicals have been implicated in the process of aging and in neurodegenerative disorders such as Parkinson's disease, the contribution of these free radicals to the pathology of these entities has yet to be clarified. It is also not certain that increased levels of free radical scavenging enzymes would attenuate the molecular and cellular processes that lead to these pathological states. In order to assess the contribution of increased SOD gene dosage to the pathogenesis of Down's syndrome, transgenic mice have been constructed that overexpress the human CuZnSOD. We are also using this model to evaluate the role of free radicals in age-associated changes in brain neurotransmitters and their receptors. In the present study, transgenic mice and their nontransgenic littermates, aged 6 weeks and 21 months, were used in an autoradiographic receptor study of the distribution of brain neurotensin receptors. At 6 weeks of age, there were no significant differences between the two groups of mice in most brain regions. In addition, [3H]NT binding sites showed parallel age-related decreases in the majority of the areas examined in both groups. However, significant age-related decreases in the septum, the diagonal band of Broca, and in some subdivisions of the caudate-putamen were observed only in SOD-Tg mice. In contrast, significant age-related decreases in the core area of the nucleus accumbens and the dorsal aspect of the dentate gyrus of the hippocampus were seen only in non-Tg mice.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Autoradiographic distribution of [3H]neurotensin receptors in the brains of superoxide dismutase transgenic mice. 839 Jan 6

The presence of cortical senile plaques and neurofibrillary tangles sufficient to warrant a neuropathological diagnosis of Alzheimer's disease is well established in middle-aged individuals with Trisomy 21 (Down's syndrome). In contrast a relationship between Down's syndrome and Lewy bodies, one of the major neuropathological features of Parkinson's disease, has not been previously reported. In a clinico-neuropathological survey of 23 cases of Down's Syndrome, two patients, aged 50 and 56 years respectively, were found to have Lewy body formation in the substantia nigra in addition to cortical Alzheimer-type pathology. Neither case showed significant substantia nigra neuron loss although locus coeruleus loss was present in both. Since substantia nigra Lewy bodies are a characteristic neurohistological feature of idiopathic Parkinson's disease, their occurrence in cases of Down's syndrome with evidence of Alzheimer-type pathology supports an aetiopathological connection between Parkinson's disease, Alzheimer's disease, and Down's syndrome; and suggests that common pathogenic mechanisms may underlie aspects of neuronal degeneration in these three disorders, some of which may relate to aberrant chromosome 21 expression.
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PMID:Detection of Lewy bodies in Trisomy 21 (Down's syndrome). 846 29

Inconsistencies within results of case-control studies on Alzheimer's disease risk factors led to a search of the literature for a potential cofactor. Reduced cerebral blood flow was selected and literature was surveyed for evidence of a cerebral blood flow linkage with the more than 40 putative risks. Alcohol abuse, depression, head trauma, underactivity, old age, sleep disturbance, glucose utilization, Down's syndrome, and Parkinson's disease are risk factors where an association with reduced cerebral blood flow is documented. Studies were cited showing that improved cerebral blood flow is associated with factors thought to be helpful in Alzheimer's disease, such as education or occupational attainment, exercise, headache, smoking, and arthritis/anti-inflammatory drugs to the extent that aspirin is used. Sugar consumption is identified as a potential risk factor with glucose management in Alzheimer's disease also shown to involve reduced cerebral blood flow. An hypothesis is developed showing how compromised regional cerebral blood flow could fit as a cofactor for genetic, autoimmune, and neurotoxic aspects of Alzheimer's disease.
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PMID:Alzheimer's disease risk factors as related to cerebral blood flow. 873 67

Amygdalae of patients with Alzheimer's disease (AD), Parkinson's disease, Down's syndrome, diffuse Lewy body disease or a combination of these diseases were probed with antibodies to neurofilament proteins as well as with Lewy body (LB)- and paired helical filament-specific antibodies. The results indicate that the amygdala is severely affected by the accumulation of both neurofibrillary tangles (NFTs) and LBs in most cases of the diseases mentioned above, and that amygdala LBs have a similar epitope composition to that of LBs in the brain stem and cerebral cortex. While large numbers of both LBs and NFTs were seen in different neurons within the amygdala, these two lesions frequently occurred together in the same neurons of the amygdala. These findings are in contrast to other sites that accumulate LBs and NFTs, but rarely both lesions in the same neuron. Thus, amygdala neurons may be selectively vulnerable to developing both LBs and NFTs, and these inclusions may play a role in the massive degeneration of these neurons in AD and LB disorders of the elderly.
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PMID:Convergence of Lewy bodies and neurofibrillary tangles in amygdala neurons of Alzheimer's disease and Lewy body disorders. 874 Feb 27

Current research into the aetiology of the dementias is focused upon genetic factors which give rise to the disease process. Recently the Apolipoprotein E gene (APO E) and in particular the epsilon 4 allele has been shown to be a risk factor for late onset Alzheimer's disease (AD) where there is an increased frequency of the epsilon 4 allele. The epsilon 4 allele has also been shown to reduce the age at onset of dementia in AD in a dose dependent manner, with the epsilon 2 allele having an opposing effect. We have genotyped a large series of clinically and neuropathologically confirmed cases of AD and found the expected increase in the Apolipoprotein epsilon 4 allele frequency when compared to a control population. Similarly, in Lewy Body Dementia (LBD) an increased epsilon 4 frequency is also found though a normal epsilon 2 frequency exists, unlike in AD where the epsilon 2 frequency is reduced. No changes in APO E allele frequencies were found in presenile AD, Parkinson's disease with or without dementia, or in Down's syndrome. No association was found between any of the APO E alleles and the histopathological indices of AD, cortical senile plaques and neurofibrillary tangles, in any disease category. Neurochemical indicators of AD, loss of choline acetyltransferase activity was also unaffected by APO E genotype. Whilst their appears to be a strong association between the APO E allele and AD and also in LBD, other related neurodegenerative disorders associated with dementia do not show such a linkage. Changes in the epsilon 2 allele frequency may indicate a genetic difference between AD and LBD. The epsilon 4 allele does not appear to influence the burden of AD type pathology and this is particularly relevant given the relative lack of NFT in LBD indicating that factors other than SP or NFT may govern the onset of dementia.
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PMID:Molecular biology of APO E alleles in Alzheimer's and non-Alzheimer's dementias. 884 67


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