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)

Nitric oxide (NO) is produced by NO synthase (NOS) in many cells and plays important roles in the neuronal, muscular, cardiovascular, and immune systems. In various disease conditions, all three types of NOS (neuronal, inducible, and endothelial) are reported to generate oxidants through unknown mechanisms. We present here the first evidence that peroxynitrite (ONOO(-)) releases zinc from the zinc-thiolate cluster of endothelial NOS (eNOS) and presumably forms disulfide bonds between the monomers. As a result, disruption of the otherwise SDS-resistant eNOS dimers occurs under reducing conditions. eNOS catalytic activity is exquisitely sensitive to ONOO(-), which decreases NO synthesis and increases superoxide anion (O(2)(.-)) production by the enzyme. The reducing cofactor tetrahydrobiopterin is not oxidized, nor does it prevent oxidation of eNOS by the same low concentrations of OONO(-). Furthermore, eNOS derived from endothelial cells exposed to elevated glucose produces more O(2)(.-), and, like eNOS purified from diabetic LDL receptor-deficient mice, contains less zinc and fewer SDS-resistant dimers. Hence, eNOS exposure to oxidants including ONOO(-) causes increased enzymatic uncoupling and generation of O(2)(.-) in diabetes, contributing further to endothelial cell oxidant stress. Regulation of the zinc-thiolate center of NOS by ONOO(-) provides a novel mechanism for modulation of the enzyme function in disease.
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PMID:Oxidation of the zinc-thiolate complex and uncoupling of endothelial nitric oxide synthase by peroxynitrite. 1190 Nov 90

A microemulsion formulation of cyclosporin (Neoral) has been developed to overcome the problems of poor and variable absorption of cyclosporin. Neoral is a potent immunosuppressive agent that is highly bound in the plasma. It has been proposed that low-density lipoprotein (LDL) delivers cyclosporin (CsA) to T-lymphocytes via the LDL receptor pathway, where it produces its therapeutic effects. Herein, we report a case of minimal change nephrotic syndrome with type 2 diabetes mellitus treated by Neoral and fluvastatin. A 65-year-old male with a 10-year history of type 2 diabetes mellitus suddenly developed nephrotic syndrome. The potential causative drugs, such as NSAIDs and antibiotics, had not been administered. The laboratory findings were as follows: proteinuria 23 g/day, serum albumin 1.9 g/dl, total cholesterol 629 mg/dl, LDL-Cho 1,930 mg/dl. Renal biopsy was normal on light microscopy, and immunofluorescence demonstrated no staining. Due to the risk of deterioration of diabetes by administering prednisolone, he was given Neoral at 2.0 mg/kg/day. He was also given fluvastatin (40 mg/day) for hyperlipidemia after the renal biopsy. At four weeks after the start of Neoral and fluvastatin, his nephrosis continued, but his LDL-Cho and total cholesterol decreased. At six weeks after treatment, proteinuria gradually reduced. At eight weeks after treatment, the proteinuria had disappeared. Nephrotic syndrome is often associated with abnormal lipid metabolism, and many patients with nephrotic syndrome show high levels of LDL-Cho. It has been reported recently that LDL apheresis is effective against nephrotic syndrome. However, in the present case, it can be speculated that the improvement of hyperlipidemia by fluvastatin probably augmented the effect of Neoral, presumably through the increased cellular uptake of Neoral. This suggests that fluvastatin may be considered as the treatment of choice for the disturbed lipoprotein profile in patients with nephrotic syndrome.
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PMID:[Complete remission of minimal change nephrotic syndrome with type 2 diabetes mellitus treated by microemulsion formulation of cyclosporin and fluvastatin]. 1197 50

The disturbance of lipid metabolism is seen in some inherited diseases and also in patients with some kinds of underlying diseases. The presence of its disturbance can be detected by measuring the concentrations of cholesterol and triglyceride in serum. Although hyperlipidemia or hypolipidemia is the result of abnormal lipid metabolism, hyperlipidemia is of more concern to physicians because of the close association with atherosclerosis. Responsible genes for some primary (or hereditary) hyperlipidemic diseases have been confirmed as follows; LPL or apo C-II for primary chylomicronemia, LDL receptor for familial hypercholesterolemia and apo B-100 for familial defective apo B-100. However, the responsible gene remains controversial for familial combined hyperlipidemia, though AI/CIII/AIV cluster is one of the possible candidate genes. Secondary hyperlipidemia is caused by various diseases such as diabetes mellitus, renal diseases and cholestasis. This type of hyperlipidemia is improved by therapy for the underlying diseases. To date, the mechanism of lipid metabolism has been defined in a molecular basis. In fact, sterol regulatory element-binding protein (SREBP), peroxisome proliferator-activated receptor (PPAR) and ATP-binding cassette transporter subfamily A, member 1(ABCA1) were recently identified and it was demonstrated that these regulate lipid metabolism.
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PMID:[Disturbance of lipid metabolism]. 1198 47

This article reviews the literature from 1986 to early 2001 relating to apoB100 and apoB48 kinetics in humans using amino acid precursors labeled with stable isotopes. The following subjects are reviewed: (1) methodology; (2) normal individuals and the effects of aging; (3) diet; (4) hereditary dyslipidemias: familial hypercholesterolemia, familial combined hyperlipidemia, cholesteryl ester storage disease, cholesteryl ester transfer protein deficiency, lipoprotein lipase deficiency, familial hypobetalipoproteinemia, and truncated forms of apoB; (5) hormonal perturbations: estrogen, insulin, diabetes, obesity, and growth hormone; (6) the nephrotic syndrome; and (7) the effects of the statin class of drugs. Because of the advances which have been made in mass spectrometry techniques, the advantages of using non-radioactive tracers in humans have made stable isotope kinetic studies the present day standard in this area of research.
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PMID:Apolipoprotein B metabolism in humans: studies with stable isotope-labeled amino acid precursors. 1199 42

Low-density lipoprotein (LDL) cholesterol reduction remains the cornerstone of coronary heart disease (CHD) prevention. The most dramatic and consistent reductions in LDL cholesterol and CHD risk are achieved with statin therapy. Identification of individuals at high CHD risk is important, not only for initiating appropriate treatment and minimizing morbidity and mortality but also for optimizing the cost-effectiveness of such treatment. A simple method for identifying high-risk individuals is to identify those with preexisting atherosclerotic disease, diabetes, or familial hypercholesterolemia (FH). Treatment options for achieving LDL cholesterol goals in high-risk patients include statins, bile acid sequestrants, niacin, and plant stanols. Statin therapy should be instituted at a dose likely to result in achievement of LDL cholesterol goals based on average response; it should then be aggressively titrated if the goals are not achieved. If LDL cholesterol goals are not achieved with maximal statin therapy, combination with a bile acid sequestrant, niacin, and/or stanols should be considered. Options likely to be available in the near future include more efficacious statins with greater potential for reducing LDL cholesterol in all patients but especially in high-risk patients, such as those with FH, enabling a greater proportion to achieve LDL cholesterol goals. Other options that may soon be available as additive agents to statins to achieve greater LDL cholesterol reductions include bile acid transport inhibitors and cholesterol absorption inhibitors.
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PMID:Identification and treatment of individuals at high risk of coronary heart disease. 1204 89

This study evaluates the influence of simvastatin on lipid concentrations and on LDL-subtype distribution in patients with heterozygous familial hypercholesterolemia and in patients with type 2 diabetes and mixed hyperlipoproteinemia. Nine patients with familial hypercholesterolemia (LDL-cholesterol: 7.1 +/- 1.1 mmol/L, triglycerides: 1.3 +/- 0.4 mmol/L) and 8 patients with type 2 diabetes mellitus and mixed hyperlipoproteinemia (HbA1c 6.8 +/- 1.1%, LDL-cholesterol: 4.8 +/- 0.7 mmol/L, triglycerides: 2.5 +/- 1.1 mmol/L) were examined. Cholesterol concentration was determined in 7 LDL-subfractions isolated by density gradient ultracentrifugation before and during simvastatin treatment (10-20 mg/d, 4 weeks). Simvastatin decreased LDL-cholesterol (-34%/-30%, all p < 0.05) and triglycerides (-2%, n.s./-25%, p < 0.05), but had little effect on HDL-cholesterol (+7%/+2%, n.s.) in patients with familial hypercholesterolemia and diabetes mellitus, respectively. In both groups a significant reduction of cholesterol in each LDL-subfraction was observed. Large-buoyant (LDL-1, LDL-2) and intermediate-dense (LDL-3, LDL-4) LDL were reduced more than small-dense (LDL-5-LDL-7) LDL-subtypes (-36%/-38%/-23%, respectively) in patients with familial hypercholesterolemia, while in diabetic patients cholesterol reduction was uniform in all LDL-subtypes (-29%/-27%/-31%, respectively). Simvastatin decreases cholesterol concentration in all LDL-subfractions in patients with familial hypercholesterolemia and in patients with diabetes mellitus with mixed hyperlipoproteinemia. However, the relative reduction of individual LDL-subtypes differed between both groups. This suggests that the effect of simvastatin on LDL-subtype distribution depends on the type of underlying hyperlipoproteinemia.
Exp Clin Endocrinol Diabetes 2002 Jun
PMID:Influence of simvastatin on LDL-subtypes in patients with heterozygous familial hypercholesterolemia and in patients with diabetes mellitus and mixed hyperlipoproteinemia. 1205 42

Wide efforts have taken place with complex metabolic disorders to emulate the success that linkage analysis has had in explaining the nature of monogenic metabolic diseases such as MODY (maturity-onset diabetes of the young) and FH (familial hypercholesterolemia). New linkage methods are being specifically developed and tested for complex disorders since some of the basic assumptions of traditional linkage analysis used with Mendelian traits are not valid. The nature of complex diseases precludes the use of extended families under the hypothesis that the same disease allele acts in most affected individuals throughout a pedigree. Rather, a multitude of genes and of rare and common alleles creates an apparently chaotic pattern of heterogeneity within and between families. Therefore, very simple family structures, in many studies even isolated sibling pairs, form the basis of efforts to compare the inheritance of disease with that of the chromosomal regions under investigation. Also, assumptions about how individual loci contribute to the overall disease inheritance used for the models applied in linkage computation have to be kept to a minimum. The overall effect of this, together with the potentially weak influence of many loci, is a heavy toll on the statistical power to detect individual contributing genes. This may be the reason why very few scans so far have yielded disease loci that meet genome-wide significance criteria. The confirmation of original loci in secondary studies has proven, as predicted, to be very difficult. Nevertheless, the overall emerging picture is very encouraging: one of the genome scans in type 2 diabetes has been carried through to the positional cloning of the underlying genetic variant, namely, the calpain 10-associated polymorphism in type 2 diabetes. Several other loci have been detected repeatedly throughout studies in various human racial groups, such as the chromosome 1q and 20q diabetes loci, and have become the target of collaborative fine-mapping efforts. Modifications to present methodology are in development with the goal to increase statistical power: examples are the use of intermediate traits with potentially increased genetic homogeneity, the investigation of admixed populations, and the study of linkage disequilibrium over wide genomic regions.
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PMID:Genetic and molecular analyses of complex metabolic disorders: genetic linkage. 1207 52

In humans, the precise mechanisms of the hypolipidemic action of fenofibrate, a peroxisome proliferator-activated receptor-alpha agonist, remain unclear. To gain insight on these mechanisms, we measured plasma lipids levels, lipids synthesis (hepatic de novo lipogenesis and cholesterol synthesis), and mRNA concentrations in circulating mononuclear cells (RT-PCR) of hydroxymethylglutaryl (HMG)-CoA reductase, LDL receptor, LDL receptor- related protein (LRP), scavenger receptor class B type I (SR-BI), ABCAI, and liver X receptor (LXR)-alpha in 10 control subjects and 9 hyperlipidemic type 2 diabetic patients. Type 2 diabetic subjects were studied before and after 4 months of fenofibrate administration. Fenofibrate decreased plasma triglycerides (P < 0.01) and total cholesterol (P < 0.05) concentrations and slightly increased HDL cholesterol (P < 0.05). Hepatic lipogenesis, largely enhanced in diabetic subjects (16.1 +/- 2.1 vs. 7.5 +/- 1.6% in control subjects, P < 0.01), was decreased by fenofibrate (9.8 +/- 1.5%, P < 0.01). Fractional cholesterol synthesis was normal in diabetic subjects (3.5 +/- 0.4 vs. 3.3 +/- 0.5% in control subjects) and was unchanged by fenofibrate (3.5 +/- 0.5%). Absolute cholesterol synthesis was, however, increased in diabetic subjects before and after fenofibrate (P < 0.05 vs. control subjects). HMG-CoA reductase, LDL receptor, LRP, and SR-BI mRNA concentrations were not different in type 2 diabetic and control subjects and were unchanged by fenofibrate. LXR-alpha mRNA levels were increased (P < 0.05) by fenofibrate. ABCAI mRNA concentrations, which were decreased in diabetic subjects (P < 0.05) before fenofibrate, were increased (P < 0.05) by fenofibrate to values comparable to those of control subjects. The plasma triglyceride-lowering effect of fenofibrate is explained in part by a decrease in hepatic lipogenesis, the moderate fall in total plasma cholesterol is not explained by a reduction of whole-body cholesterol synthesis, and the increase in LXR-alpha and ABCAI mRNA levels suggests that fenofibrate stimulated reverse cholesterol transport.
Diabetes 2002 Dec
PMID:Mechanisms of the triglyceride- and cholesterol-lowering effect of fenofibrate in hyperlipidemic type 2 diabetic patients. 1245 4

Lipid-lowering agents have been shown to reduce morbidity and mortality associated with coronary heart disease (CHD), particularly in high-risk patients. The identification and treatment of these patients should therefore be a high priority for clinicians. Guidelines from medical organizations, such as the National Cholesterol Education Program Adult Treatment Panel (NCEP ATP) and the American Diabetes Association (ADA), suggest that patients with low-density lipoprotein cholesterol (LDL-C) levels > or =130 mg/dL, and perhaps even those with levels > or =100 mg/dL, should receive drug therapy. Optimal LDL-C levels have been set at <100 mg/dL and <115 mg/dL for high-risk patients by US and European guidelines, respectively. However, a recent survey shows that only about 20% of high-risk patients currently meet these goals. In order to achieve therapeutic targets for LDL-C, the statins are the foundation of treatment, as they are the most effective and best-tolerated form of lipid-lowering therapy. Other therapeutic options include bile acid sequestrants, niacin, and plant stanols, although seldom as monotherapy. Combination therapy with a statin and one of these other lipid-lowering agents can be useful in patients who are unable to achieve target lipid levels through monotherapy. There remains, however, a need for additional agents. Some of the new options for reducing LDL-C levels that may be available in the near future include 2 new statins, pitavastatin and rosuvastatin. In patients with heterozygous familial hypercholesterolemia, rosuvastatin, which is currently under review by the Food and Drug Administration (FDA), has been shown to produce significantly greater reductions in LDL-C than atorvastatin over its full dose range. In comparative clinical trials, it has also enabled more patients with primary hypercholesterolemia to meet lipid goals than atorvastatin, simvastatin, and pravastatin. Inhibitors of bile acid transport or cholesterol absorption may also have therapeutic value. The first cholesterol absorption inhibitor, ezetimibe, which has just been approved by the FDA, appears to be most effective when combined with a statin. It is anticipated that such new options will allow clinicians to optimize the management of dyslipidemia in high-risk patients, thereby reducing the morbidity and mortality of CHD.
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PMID:Management of dyslipidemia in the high-risk patient. 1248 15

Diabetes is associated with significant changes in plasma concentrations of lipoproteins. We tested the hypothesis that lipoproteins modulate the function and survival of insulin-secreting cells. We first detected the presence of several receptors that participate in the binding and processing of plasma lipoproteins and confirmed the internalization of fluorescent low density lipoprotein (LDL) and high density lipoprotein (HDL) particles in insulin-secreting beta-cells. Purified human very low density lipoprotein (VLDL) and LDL particles reduced insulin mRNA levels and beta-cell proliferation and induced a dose-dependent increase in the rate of apoptosis. In mice lacking the LDL receptor, islets showed a dramatic decrease in LDL uptake and were partially resistant to apoptosis caused by LDL. VLDL-induced apoptosis of beta-cells involved caspase-3 cleavage and reduction in the levels of the c-Jun N-terminal kinase-interacting protein-1. In contrast, the proapoptotic signaling of lipoproteins was antagonized by HDL particles or by a small peptide inhibitor of c-Jun N-terminal kinase. The protective effects of HDL were mediated, in part, by inhibition of caspase-3 cleavage and activation of Akt/protein kinase B. In conclusion, human lipoproteins are critical regulators of beta-cell survival and may therefore contribute to the beta-cell dysfunction observed during the development of type 2 diabetes.
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PMID:Insulin-secreting beta-cell dysfunction induced by human lipoproteins. 1259 27


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