Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Advanced glycation end-products (AGEs) are formed by spontaneous chemical reactions between carbohydrates and tissue proteins. The accumulation of AGEs in long-lived proteins contributes to the age-related increase in brown colour, fluorescence and insolubilisation of lens crystallins and to the gradual crosslinking and decrease in elasticity of connective tissue collagens with age. These nonenzymatic reactions, known collectively as Maillard or browning reactions, are also implicated in the development of pathophysiology in age-related diseases such as diabetes mellitus, atherosclerosis, Alzheimer's disease, and in dialysis-related amyloidosis. Oxygen and oxidation reactions accelerates Maillard reactions in vitro, and the structurally characterised AGEs that accumulate in long-lived tissue proteins are in fact glycoxidation products, formed by sequential glycation and oxidation reactions. In addition to their immediate effects on protein structure and function, AGEs also induce oxidative stress, leading to inflammation and propagation of tissue damage. Thus, glycation of protein, formation of AGEs and resultant oxidative stress, which accelerate Maillard reactions, can initiate an autocatalytic cycle of deleterious reactions in tissues. Pharmacological inhibition of the Maillard reaction should improve the prognosis for a broad range of age-related diseases. The role of oxidative stress as a catalyst and the consequences of Maillard reaction damage in tissues suggests that antioxidant therapy may also retard the progression of age-related pathology.
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PMID:Role of the Maillard reaction in diabetes mellitus and diseases of aging. 882 Jul 92

In living organisms a large number of enzymes are working in complicated networks to express various biological functions. In order to analyze such functions from various aspects, specific enzyme inhibitors are likely to become useful tools. They are also useful for the studies of reaction mechanisms and analysis of three-dimensional structures of enzymes. Moreover, they are of great value in elucidating disease processes and seem to have usefulness in treatment of various diseases. Searching for inhibitors in culture filtrate of microbes, we discovered many substances which specifically inhibit various enzymes such as endopeptidases, exopeptidases, glycosidases, lipases, an so forth. These inhibitors have low-molecular-weights and unique structures. We found significant activities of exopeptidases, alkaline phosphatases, esterases, and so forth, on surface membranes of various mammalian cells. Searching for specific inhibitors against these cell surface enzymes, we have discovered many interesting inhibitors. These inhibitors proved to bind to the cellular surface and to modify the functions of cells involved in immune responses. Thus the studies on these enzyme inhibitors may well afford important keys to understand various aspect of biological phenomena and diseases: inflammation, immune response, hypertension, hyperlipemia, diabetes, Alzheimer's disease, carcinogenesis, metastasis, viral infection, autoimmune diseases, and so forth. Because of their interesting pharmacological activities, some of the inhibitors are now under clinical evaluation for their uses as medical drugs. Enzyme inhibitors seems to propose a new promising field of science.
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PMID:[Screening, characterization and pharmaceutical and medical application of enzyme inhibitors from microbial origin with low-molecular-weight]. 883 Dec 59

Many human diseases result from the combined effect of several genetic and non genetic factors. Thanks to the development of powerful tools for molecular analysis, researchers in recent years have begun to uncover the genes behind such multifactorial neurologic and systemic disorders as Alzheimer's and Parkinson's diseases and diabetes. Likewise investigators have been able to confirm that the course of these diseases and their clinical manifestations depend on the concurrence in the same individual of specific genetic variations. Because each gene confers a certain degree of predisposition to a specific disease, they are therefore called susceptibility genes. The search for and analysis of susceptibility genes in defined populations is termed genetic epidemiology. This multidisciplinary science is providing valuable data that further our understanding and ability to diagnose of disorders of the nervous system. It also enables us to predict the clinical course of disease in a given patient with a high degree of reliability, even when no clinical signs are yet evident.
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PMID:[Genetic neuroepidemiology]. 883 59

How much vitamin E is enough? An established use of supplemental vitamin E in humans is in the prevention and therapy of deficiency symptoms. The cause of vitamin E deficiency, characterized by peripheral neuropathy and ataxia, is usually malabsorption-a result of fat malabsorption or genetic abnormalities in lipoprotein metabolism. Genetic abnormalities in the hepatic alpha-tocopherol transfer protein also cause vitamin E deficiency-defects in this protein cause an impairment in plasma vitamin E transport. Impaired delivery of vitamin E to tissues, thereby, results in deficiency symptoms. Also discussed is the use of supplemental vitamin E in chronic diseases such as ischemic heart disease, atherosclerosis, diabetes, cataracts, Parkinson's disease, Alzheimer's disease, and impared immune function, as well as in subjects receiving total parenterol nutrition. In healthy individuals, a daily intake of about 15-30 mg of alpha-tocopherol is recommended to obtain "optimal plasma alpha-tocopherol concentrations" (30 microM or greater).
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PMID:Vitamin E in humans: demand and delivery. 883 30

The requirements for amyloidogenesis, as it is currently understood, include an adequate amyloid precursor pool, a nidus for fibrillogenesis, interactions with a set of common components (most of which are involved in basement membrane structure) and amyloid turnover. These factors serve as the basis for therapeutic attack. General strategies focusing on each of these factors are presented with examples from the experimental and clinical literature. These include reducing the amyloid precursor protein pool in familial amyloid polyneuropathy by liver transplantation, inhibiting nidus formation in familial Mediterranean fever by the use of colchicine, inhibiting amyloid precursor protein/heparan sulphate interaction in experimental inflammation-associated amyloidosis by the use of novel small molecule anionic sulphates and sulphonates, and the use of new analogues of doxorubicin in light chain amyloidosis to accelerate amyloid removal. The potential significance of local and systemic amyloid deposits is discussed in the light of new information on the genetics of Alzheimer's disease, observations made in patients receiving long term dialysis for renal failure, and the potential involvement of amyloid deposits in the pathogenesis of non-insulin-dependent diabetes mellitus.
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PMID:Anti-amyloid drugs: potential in the treatment of diseases associated with aging. 884 88

Free radicals are defined as atoms or molecules that contain one or more unpaired electrons. The toxicity of many xenobiotics is associated with the metabolic activation of foreign compounds to form free radicals or with the production of reactive oxygen species as superoxide anion, hydroxyl radicals or hydrogen peroxide which are responsible for the tissue damaging effects as lipid peroxidation, and DNA and protein damage. Oxidative stress associated with production of reactive oxygen species is believed to be involved not only in the toxicity of xenobiotics but also in the pathophysiology of aging, and various age-related diseases, including cataracts, atherosclerosis, neoplastic diseases, diabetes, diabetic retinopathy, chronic inflammatory diseases of the gastrointestinal tract, aging of skin, diseases associated with cartilage, Alzheimer's disease, and other neurologic disorders. The cellular sources of free radicals and reactive oxygen species, the biological targets of free radicals, and clinical conditions which are associated with free radical production and tissue damage are reviewed. In addition, potential therapeutic approaches to the prevention of free radical damage are considered. Free radical-induced injury can explain many clinical conditions.
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PMID:The role of free radicals in toxicity and disease. 885 68

Apolipoprotein E (ApoE) has recently been proposed as an aetiological factor of Alzheimer's disease (AD): ApoE is co-localized to amyloid plaques and neurofibrillary tangles in the brain and binds to A beta-protein in vitro. An association of ApoE epsilon 4 allele with the development of AD has been reported. Islet amyloid is formed from islet amyloid polypeptide (IAPP) in pancreatic islets of 90 per cent of patients with non-insulin-dependent diabetes mellitus (NIDDM) which, like AD, is an age-dependent pathology. The relationship of ApoE to islet amyloid and other amyloidoses is largely unknown. In this study, ApoE was localized by immunocytochemistry on pancreatic specimens from non-diabetic man, monkey, and mouse, and on amyloid-containing human tissues from pancreas, heart, brain, and intestine. All types of amyloid deposits, irrespective of the constituent peptide, site of deposition, or species, showed immunoreactivity for ApoE (ApoE-IR). Quantitative morphometry showed that similar proportions of islet amyloid were labelled for IAPP and ApoE in monkey islets. ApoE-IR was observed in pancreatic islet cells of non-diabetics. These results suggest that the association of ApoE with amyloid is non-specific for AD or to the component peptide of amyloid fibrils. If ApoE promotes amyloid formation, its synthesis in pancreatic islets could be important for the initiation or the development of pancreatic amyloid in NIDDM.
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PMID:Apolipoprotein E is associated with islet amyloid and other amyloidoses: implications for Alzheimer's disease. 886 95

Dehydroepiandrosterone (DHEA; prasterone) is a major adrenal hormone with no well accepted function. In both animals and humans, low DHEA levels occur with the development of a number of the problems of aging: immunosenesence, increased mortality, increased incidence of several cancers, loss of sleep, decreased feelings of well-being, osteoporosis and atherosclerosis. DHEA replacement in aged mice significantly normalised immunosenescence, suggesting that this hormone plays a key role in aging and immune regulation in mice. Similarly, osteoclasts and lymphoid cells were stimulated by DHEA replacement, an effect that may delay osteoporosis. Recent studies do not support the original suggestion that low serum DHEA levels are associated with Alzheimer's disease and other forms of cognitive dysfunction in the elderly. As DHEA modulates energy metabolism, low levels should affect lipogenesis and gluconeogenesis, increasing the risk of diabetes mellitus and heart disease. Most of the effects of DHEA replacement have been extrapolated from epidemiological or animal model studies, and need to be tested in human trials. Studies that have been conducted in humans show essentially no toxicity of DHEA treatment at dosages that restore serum levels, with evidence of normalisation in some aging physiological systems. Thus, DHEA deficiency may expedite the development of some diseases that are common in the elderly.
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PMID:Dehydroepiandrosterone and diseases of aging. 889 25

Advanced glycation end-products (AGE) are formed in the late phase of the non-enzymatic glycosylation reaction in conditions such as diabetes mellitus and aging. In amyloidosis, AGE have been found in the A beta 2M amyloid associated with long-term hemodialysis and in the beta-protein in Alzheimer's disease. Murine AApoAII and AA amyloidosis were examined immunohistochemically using anti-AGE monoclonal antibody, 6D12. AApoAII amyloid deposits studied in one senescence-accelerated mouse P1 (SAMP1), congenic mice that have the amyloidogenic apolipoprotein A-II of SAMP1 mice, and AKR mice all reacted with biotinylated 6D12 by formic acid pretreatment, whereas AA amyloid deposits did not react with the antibody. The immunoreaction with anti-apolipoprotein A-II for amyloid deposits in senile mice was approximately homogeneous in intensity; on the other hand the reaction with biotinylated 6D12 was irregular in distribution and intensity over the amyloid deposits. These findings suggest that amyloid precursor proteins are not associated uniformly with AGE modification before deposition as amyloid; it is more likely that the AGE modification progresses gradually and unevenly after amyloid deposition. Murine amyloidosis may be a useful model to elucidate the role of AGE in amyloidosis.
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PMID:Immunohistochemical study with anti-advanced glycation end-products antibody in murine amyloidosis. 891 42

Blood glucose levels are abnormally low in Alzheimer's dementia. We therefore examined glucose metabolism before death in relation to Alzheimer's dementia as determined at autopsy in 106 men and 161 women. The mean age was 81.8 +/- 8.6 years for men and 85.8 +/- 7.9 years for women (p < 0.001). The fasting plasma glucose level and hemoglobin Alc levels did not differ by sex. Alzheimer's dementia was detected in 88 patients (25.5%). More women than men had the disease, but the difference was not significant. Only 8.8% (3/34) of patients with diabetes mellitus had Alzheimer's dementia, as compared with 27.9% of patients without diabetes mellitus (65/233, p < 0.03). The fasting plasma glucose level was 89.9 +/- 13.4 mg/dl in patients with Alzheimer's dementia and 102.9 +/- 34.5 mg/dl in those without the disease. The hemoglobin Alc level was 5.7 +/- 0.8% in patients with Alzheimer's dementia and 6.4 +/- 1.5% in those without the disease. Both the fasting glucose level and hemoglobin Alc level were significantly lower in patients with Alzheimer's dementia than in those without the disease, p < 0.01. These data suggest that the development of Alzheimer's dementia is suppressed by the high plasma glucose levels in patients with diabetes mellitus.
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PMID:[Glucose metabolism and Alzheimer's dementia]. 892 93


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