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

Early development of arteriosclerosis is a main late complication of diabetes mellitus. Although its uptake by LDL receptors is impaired, glycated LDL is thought to play a role in foam cell formation from macrophages. In the present study we show binding of glycated LDL (8-9 mol fructosyllsine/mol apo B) to macrophages and to the monocyte-like cell line U937. The binding involves fructosyllysine-specific binding sites, as well as LDL and scavenger receptors. Fructosyllysine and glycated albumin were competitors for binding of 125I-labelled glycated LDL by macrophages and U937 cells. Scatchard analysis of binding data using a two ligands binding model showed a linear plot with Ka = 2.6 x 10(7) M-1 for U937 cells, which lack scavenger receptors. On U937 cells only the 200 kDa fructosyllysine-specific receptor protein and the 165 kDa LDL receptor were involved in binding glycated LDL as evidenced by ligand blotting. U937 cell uptake and degradation of glycated LDL was mediated by fructosyllysine-specific and LDL receptors. Binding of glycated LDL by macrophages via fructosyllysine-specific sites could be demonstrated in only 6 from 35 rats investigated, indicating that the receptor is not expressed in each individual. Whether the fructosyllysine-specific receptor mediated pathway is relevant for uptake and degradation of glycated LDL in vivo is yet to be determined.
Exp Clin Endocrinol Diabetes 1997
PMID:Evidence for binding of in vitro glycated low-density lipoproteins by fructosyllysine-specific sites on macrophages and U937 monocyte-like cells. 935 54

Chylomicrons are formed in the intestine and transport dietary triglyceride to peripheral tissues and cholesterol to the liver. The enzyme lipoprotein lipase, with apolipoprotein (apo)C-II as a co-factor, hydrolyzes chylomicron triglyceride allowing the delivery of free fatty acids to muscle and adipose tissue. As a result, a new particle called a chylomicron remnant is formed. This particle is enriched in cholesteryl ester and fat-soluble vitamins and contains apoB-48 and apoE. It is rapidly removed from the circulation by the liver. ApoE is the moiety required for rapid hepatic removal. Its activity is inhibited by C apolipoproteins, especially apoC-I. Hepatic removal appears to be accomplished by several overlapping mechanisms. The particle must first achieve a size that allows it to be "sieved" through the endothelial fenestre allowing entrance into the space of Disse. Here, it may 1) be removed directly by LDL receptors; 2) acquire additional apoE that is secreted free into the space, and then be removed directly by the LDL receptor-related protein (LRP); or 3) it may be sequestered in the space. Sequestration occurs by binding of apoE to heparan sulfate proteoglycans and/or binding of apoB to hepatic lipase. Sequestered particles may be further metabolized allowing apoE, and lysophospholipid enrichment, followed by transfer to one of the above receptors for hepatic uptake. The above formulation is based upon animal studies. In humans, delayed removal of chylomicron remnants has been documented in diabetes, renal failure, and familial combined hyperlipemia and is the abnormality resulting in type III hyperlipidemia. Case control studies have identified delayed remnant removal as an independent risk factor for atherosclerotic cardiovascular disease. Thus, understanding the further details of the processes, and how it can be regulated in humans, is an important challenge for the future.
 ...
PMID:Hepatic uptake of chylomicron remnants. 939 16

To elucidate the mechanism of foam cell formation in the mesangial region of a kidney observed in a familial type III hyperlipoproteinemic patient presenting with diabetes mellitus and nephrotic syndrome, we have examined, in the present study, the effect of human beta-VLDL (apo E2/E2) on foam cell formation in human mesangial cells, since an increase in beta-VLDL is a characteristic feature of this patient. Human beta-VLDL (apo E2/E2) induced foam cell formation in human mesangial cells. The binding of [125I]LDL to human mesangial cells was inhibited completely by both LDL and beta-VLDL. On the other hand, the binding of [125I]beta-VLDL was completely inhibited by beta-VLDL, but partially by LDL. The LDL receptor, but not the VLDL receptor was down-regulated by accumulation of cholesteryl esters. These results suggest that human beta-VLDL (apo E2/E2)-induced foam cell formation in mesangial cells is mediated through both the LDL receptor pathway and the beta-VLDL specific pathway, in which the VLDL receptor is one of the candidates.
 ...
PMID:Human beta-migrating very low density lipoprotein induces foam cell formation in human mesangial cells. 943 Mar 72

Though severe hyperlipidaemia (total cholesterol level > or = 13 mmol/l in this study) is uncommon, it is important to make a precise diagnosis. We examined 57 patients with isolated severe hypercholesterolaemia. Of these, four were homozygotes for familial hypercholesterolaemia, 48 were heterozygotes for familial hypercholesterolacmia and one had sitosterolemia. The heterozygotes carried 15 different LDL receptor mutations, with no one mutation predominating. When the diagnosis is made, relatives should be given the opportunity to be tested. Combined severe hyperlipidaemia is usually due to a secondary cause, at our clinic, the most common cause is diabetes mellitus. The underlying disease should be treated first. However, many patients will require additional lipid-lowering drugs because the underlying disease may be associated with an increased risk of cardiovascular disease. With the exception of fish oil capsules, drugs that reduce serum triglyceride levels substantially are not registered in Norway at present.
 ...
PMID:[Diagnosis and treatment of severe hyperlipidemia]. 944 69

A young woman was diagnosed with systemic lupus erythematosus at the age of 7 years and incurred an acute myocardial infarction at the age of 17 years. Her risk factors for coronary artery disease include hypertension, hypercholesterolemia, a relatively long disease duration, a fairly active disease as evidenced by the history of nephrotic syndrome and other organ system involvement, and a long history of prednisone use. It is difficult to determine the etiology of this patient's acute myocardial infarction without coronary artery histopathology, but aspects of her presentation (a history of virulent systemic lupus erythematosus, and the angiographic findings of ectasia and aneurysm) suggest that coronary arteritis was the etiology of her accelerated coronary artery disease and subsequent myocardial infarction. Acute myocardial infarction is an uncommon occurrence in premenopausal women less than 30 years old.35 These patients are typically found to have an associated systemic disease such as diabetes mellitus or familial hypercholesterolemia. Systemic lupus erythematosus is a less common systemic disease associated with premature coronary artery disease. Mechanisms of acute coronary syndromes in these patients include accelerated atherosclerosis, active coronary vasculitis, and/or vasospasm with superimposed thrombosis.
 ...
PMID:Acute myocardial infarction in a young woman with systemic lupus erythematosus. 954 9

Severe hyperlipidemias should be diagnosed and treated even in childhood and adolescence, because vascular lipid deposition in the form of fatty streaks and progressive atherosclerotic lesions start to develop early in life. The heterozygous form of familial hypercholesterolemia found in about 1 of 500 newborn infants, and polygenic forms of hypercholesterolemia, are the most frequent forms of primary genetic hypercholesterolemia found in children. Secondary hyperlipidemias, e.g. in diabetes mellitus, hypothyroidism and renal disease, are relatively frequent in children and adolescents and need to be searched for in the diagnostic evaluation, because they can be influenced by treatment of the underlying disorder. Children and adolescents with severe forms of hyperlipidemias should be diagnosed and treated early in life. Dietary modification is the basis of treatment of affected children and can lower LDL cholesterol by about 15-20%. In patients with severe hypercholesterolemia, dietary cholesterol intake should not exceed 150 mg/day in children or 250-300 mg/day in adolescents. Even more important is a reduction of the intake of saturated fats and trans fatty acids and their replacement by polyunsaturated and particularly monounsaturated fats. Some additional lowering of LDL cholesterol may be achieved by the preferential use of vegetable over animal proteins and of complex carbohydrates over sugars. Repeated motivation, counseling and intensive practical training of the patient and family, supported by appropriate teaching materials, are essential for effective dietary treatment. Additional drug treatment is considered in children from the age of 8-9 years of age onwards if, in spite of adequate dietary modification, LDL cholesterol remains above 190 mg/dl (4.9 mmol/l), or above 160 mg/dl (3.9 mmol/l) in the presence of additional risk factors. The drugs of first choice are anion exchange resins (colestyramine or colestipol) because of their well documented efficacy and safety. More convenient to take but often somewhat less effective is beta-sitosterol. If efficacy or compliance with resins or sitosterin is unsatisfactory, fibrates (e.g. bezafibrate, fenofibrate) may be considered as a drug of second choice. Cholesterol synthesis inhibitors are not recommended for general use in children at this time.
 ...
PMID:[Hyperlipidemia in children and adolescents: diagnosis and therapy]. 958 98

Dyslipidemia is said to be present when lipid or lipoprotein levels lie within a range which is known from epidemiological studies to be associated with secondary complications, in particular atherosclerosis of the coronary arteries, or when a lipid or lipoprotein grossly deviates from the norm as in abetalipoproteinemia, hypobetalipoproteinemia or the HDL deficiency syndromes. In most cases, dyslipidemia is due not to a single genetic or environmental factor, but to a combination of the effects of several genes of small effect (polygenes) and environment. In other cases, however, dyslipidemia is caused by a mutation in a single gene of large effect. In such cases, the extent and nature of the phenotype depends primarily on the identity of the gene involved, but is also modulated to an important degree by the nature of the mutation and the genetic and environmental background against which this mutation occurs. In addition, many cases of hyperlipidemia are secondary to other disorders such as hypothyroidism or renal dysfunction. Such disorders may also unmask or exacerbate a genetic lipoprotein disorder. Examples of the latter are the unmasking of type III hyperlipidemia by diabetes mellitus or the exacerbation of familial hypercholesterolemia by hypothyroidism.
 ...
PMID:Lipoproteins and cardiovascular risk-from genetics to CHD prevention. 963 14

The aim of this in vitro study was to investigate the effect of troglitazone, a new oral antidiabetic agent, on LDL catabolism. HepG2 cells, which are cells from a well-differentiated cell line of hepatoma cells, were cultured and used to study LDL catabolism. Different concentrations of troglitazone, all within the therapeutic range for humans, were incubated in culture medium with 125I-labeled LDL to measure cell-associated and degraded 125I-LDL. Troglitazone increased cell-associated and degraded 125I-LDL by approximately 30%. We also investigated if this effect occurred through a LDL receptor-mediated pathway or a non-LDL receptor pathway. By using dextran sulfate, a substance known to release bound LDL from its receptor, we found that troglitazone upregulated LDL receptor activity by approximately 35%. In addition, we found that troglitazone increased the expression of the LDL receptor mRNA. The effect of troglitazone was comparable with that of a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, fluvastatin, with troglitazone having an upregulatory effect similar to that of fluvastatin. Insulin within human physiological concentrations also increased LDL receptor activity. We found that troglitazone and insulin had an additive effect on LDL catabolism. Also, the effect of troglitazone on LDL catabolism was studied in the presence of cyclosporine, an immunosuppressant drug that reduces LDL catabolism mainly by decreasing LDL receptor activity. The results showed that troglitazone can compensate for the reduced LDL receptor activity induced by cyclosporine, but that cyclosporine had a residual effect on the action of troglitazone. Thus troglitazone enhanced LDL binding, cell association, and degradation by increasing LDL receptor mRNA expression, with a subsequent increase in LDL receptor activity.
Diabetes 1998 Aug
PMID:Troglitazone upregulates LDL receptor activity in HepG2 cells. 970 16

To identify Chinese geneticists' views of ethical issues in genetic testing and screening, a national survey was conducted. Of 402 Chinese geneticists asked to participate, 255 (63%) returned by mail anonymous questionnaires. The majority of respondents thought that genetic testing should be offered in the workplace for alpha-antitrypsin deficiency (95%) and the predisposition of executives to heart disease, cancer, and diabetes (94%); that genetic testing should be included in preemployment physical examinations (86%); that governments should require premarital carrier tests (86%), newborn screening for sickle cell (77%), and Duchenne muscular dystrophy (71%); and that children should be tested for genes for late-onset disorders such as Huntington disease (85%), susceptibility to cancers (85%), familial hypercholesterolemia (84%), alcoholism (69%), and Alzheimer disease (61%). Most believed that partners should know each other's genetic status before marriage (92%), that carriers of the same defective gene should not mate with each other (91%), and that women should have a prenatal diagnosis if medically indicated (91%). The majority said that in China decisions about family planning were shared by the couple (82%). More than half had views that, in China, there were no laws to prohibit disability discrimination (64%), particularly to protect people with adult polycystic kidney disease (57%), cystic fibrosis (56%), or genetic predisposition to other diseases (50%). To some extent, these results might provide a basis for a discussion of eugenics in China, particularly about China's Maternal and Infant Health Care Law (1994).
 ...
PMID:Chinese geneticists' views of ethical issues in genetic testing and screening: evidence for eugenics in China. 1048 40

In patients with diabetes, non-enzymatic glycation of low-density lipoprotein (LDL) has been suggested to be involved in the development of atherosclerosis. alpha-Dicarbonyl compounds were identified as intermediates in the non-enzymatic glycation and increased levels were reported in patients with diabetes. We studied the effect of the alpha-dicarbonyl compound methylglyoxal (MG) on the physicochemical and biological properties of LDL. MG dose-dependently modifies LDL, as indicated by the formation of fluorescent products and the increase of a net negative charge. MG (10 mmol/l) induced major modifications of arginine residues (up to 85%) and minor lysine modifications (less than 6%). MG-LDL preparations generated small amounts of superoxide anion radicals as measured by the reduction of cytochrome c, but this was not accompanied by peroxidation of the polyunsaturated fatty acids of MG-LDL. MG-LDL showed diminished recognition and uptake by the human LDL receptor in cultured cells and a markedly increased plasma clearance rate in vivo in rats. The reduced association and degradation of 125I-oxidised LDL by murine macrophages indicates recognition of MG-LDL by a scavenger receptor. Surprisingly, MG-LDL caused significantly less cholesteryl ester synthesis in murine macrophages, as compared to native LDL and oxidised or acetylated LDL. Highly modified MG-LDL did not induce activation of human endothelial cells, as measured by the expression of monocyte chemoattractant protein-1 and vascular cell adhesion molecule-1.
 ...
PMID:Effect of methylglyoxal on the physico-chemical and biological properties of low-density lipoprotein. 979 11


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>