Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020473 (hyperlipidemia)
 15,891 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Because the reduced plasma oncotic pressure from hypoproteinemia causes hyperlipidemia, serum albumin levels should be maintained during low-density lipoprotein (LDL) apheresis. The amount of albumin loss was evaluated in seven patients with familial hypercholesterolemia during LDL apheresis in which columns packed with dextran sulfate-cellulose beads were used as a selective adsorbent of LDL. Serum albumin level significantly decreased from 4.3 +/- 0.3 (mean +/- SD) g/dl to 3.6 +/- 0.2 g/dl. The albumin loss was assessed by two different methods: 1) radioimmunoassay of microalbumin content in the discarded fluid, and 2) measurement of changes in plasma albumin reserve. The albumin losses during one apheresis session were 3.7 +/- 2.9 g and 8.3 +/- 5.7 g, respectively, depending upon which of two different methods was used. There was a significant correlation between these two methods (r = 0.84, p less than 0.02). The amount of albumin loss during apheresis was estimated to be between 4.1% and 9.1% of total plasma albumin reserve, and more than half of the decreased serum albumin level appeared to be attributable to dilution due to the electrolyte solution used for priming of the extracorporeal circuit.
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PMID:Evaluation of albumin loss during low-density lipoprotein apheresis. 226 88

Homozygosity for the apolipoprotein (apo) E variant apoE2(158 Arg----Cys) invariably gives rise to dysbetalipoproteinemia, and when associated with obesity or a gene for hyperlipidemia, results in type III hyperlipoproteinemia. The association of the E2/2 phenotype with type IV/V hyperlipoproteinemia rather than type III hyperlipoproteinemia in identical twin brothers led us to investigate the primary structure of their apoE. Lipoprotein electrophoresis on agarose gels confirmed the presence of increased very low density lipoproteins (VLDL) and chylomicrons but little, if any, beta-VLDL, indicating that these subjects did not have dysbetalipoproteinemia. When the apoE from these twins was subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis on a system that can distinguish apoE2(158 Arg----Cys) from all other known apoE variants, it gave rise to two components. One had the unique mobility of apoE2(158 Arg----Cys), and one migrated in the position of the other variants of apoE (and normal apoE3), indicating that the brothers were heterozygous for apoE2(158 Arg----Cys) and a second apoE2 isoform. Cysteamine modification and isoelectric focusing showed that, like apoE2(158 Arg----Cys), the second apoE2 isoform also contained two cysteine residues. The structural mutation in the second apoE2 isoform was determined by peptide sequencing. Like normal apoE3, this variant had arginine at position 158, but differed from apoE3 by the substitution of cysteine for arginine at position 228. Total apoE isolated from the brothers had the same receptor-binding activity in a competitive binding assay as a 1:1 mixture of normal apoE3 and apoE2(158 Arg----Cys).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Apolipoprotein E2-Dunedin (228 Arg replaced by Cys): an apolipoprotein E2 variant with normal receptor-binding activity. 234 12

A monoclonal antibody-based direct binding enzyme-linked immunosorbent assay (ELISA) for apoprotein (apo) B-100 has been developed for use as a reference method. The assay uses the two well-characterized monoclonal antibodies, MB24 and MB47. MB47, which recognizes an epitope at the low density lipoprotein (LDL) receptor-binding domain of apoB and is specific for apoB-100, is bound to the microtiter plate as the capture antibody. MB24, which binds an epitope in the amino terminal half of the apoB-100 and identifies both apoB-100 and apoB-48, is conjugated to horseradish peroxidase and is utilized as the indicating antibody. The assay was calibrated with LDL (d 1.030-1.050 g/ml) and the LDL protein was determined by a sodium dodecyl sulfate (SDS) Lowry procedure. The working range of the assay is 0.25-1.25 micrograms/ml. Optimal dilution of whole plasma was found to be 1:2000. In the assay, MB47 bound approximately 97% of the apoB in all low density lipoprotein, and greater than 90% of the apoB in the majority of very low density lipoprotein preparations. Small dense LDL from subjects with familial combined hyperlipidemia (FCHL) and large bouyant LDL from subjects with familial hypercholesterolemia (FH) exhibited binding properties similar to LDL from healthy normolipidemic subjects when tested in the reference ELISA. The intra- and interassay coefficients of variation averaged 2.5% and 6.0%, respectively. Plasma B-100 levels were not influenced by freezing and thawing or storage at 4 degrees C for up to 3 weeks or storage at -70 degrees C for up to 11 months. Excellent agreement was obtained between the reference ELISA and a polyclonal RIA which measures total apoB (r = 0.93, n = 105, mean ELISA B-100 value = 100 mg/dl, mean RIA value = 101 mg/dl, Sy = 9.6). Reference ELISA B-100 values of samples pretreated with bacterial lipase were not significantly increased in most samples with plasma triglyceride levels below 600 mg/dl. To help reduce the large among-laboratories variability of apoB measurements, we recommend that this candidate reference direct binding ELISA be used to assign apoB target values to apoB reference pools.
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PMID:Evaluation of a monoclonal antibody-based enzyme-linked immunosorbent assay as a candidate reference method for the measurement of apolipoprotein B-100. 260 May 45

The biochemistry, etiology, and evaluation of hyperlipidemia and its management, including dietary and drug therapies, are discussed. Strong evidence supports the role of increased cholesterol concentrations as an independent risk factor for coronary artery disease (CAD); however, evidence that elevated triglyceride concentrations are also an independent risk factor remains questionable. The cornerstone of the laboratory diagnosis of hyperlipidemia involves repeated measurement of serum or plasma cholesterol and triglyceride concentrations. The goals of therapy should be to reduce cholesterol or triglyceride concentrations or both to below the 75th percentile, modify co-existing risk factors, individualize the treatment, and minimize any adverse effects. Specific interventions must be determined on the basis of patient age, gender, etiology of hyperlipidemia, presence of other risk factors, and degree of lipid abnormality. The majority of patients may be managed with dietary therapy alone. The three-phase diet developed by the American Heart Association emphasizes a gradual reduction in cholesterol and fats with the substitution of polyunsaturated for saturated fats. Patients at risk for CAD with sustained elevations in plasma cholesterol concentrations above the 95th percentile or a triglyceride concentration above 500 mg/dL after an adequate dietary trial should be considered for drug therapy. The effects of cholestyramine and colestipol hydrochloride, niacin, dextrothyroxine, clofibrate, neomycin sulfate, probucol, gemfibrozil, and mevinolin and compactin on lipids and lipoproteins are reviewed. Hyperlipidemia should be managed systematically using information about the association between increased lipid concentrations and CAD, patient risk factors, and limitations of both diet and drug therapy.
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PMID:Contemporary recommendations for evaluating and treating hyperlipidemia. 351 84

The glomerulus is a complex structure containing a remarkable capillary bed which is freely permeable to water and solutes up to the size of inulin. Many small proteins are filtered, reabsorbed, and catabolized by the kidney; but most large proteins, such as albumin or immunoglobulins, are almost entirely excluded from the glomerular ultrafiltrate due to the charge-size permselectivity of the glomerular capillary basement membrane. These large proteins appear in the urine when diseases reduce the charge selectivity or result in the development of large pores in this membrane. The reabsorptive capacity of the renal tubules for these proteins is overwhelmed. Hypoalbuminemia results when increased synthetic and decreased catabolic rates of albumin fail to compensate for the urinary loss of the protein. The resulting decrease in serum oncotic pressure increases the flux of fluid out of systemic capillaries into the interstitial space, a process that increases lymphatic flow and returns the relatively protein-poor ultrafiltrate to the plasma compartment. Interstitial proteins are swept into the plasma by the increased lymphatic flow, leading to a depletion of the extravascular pool of albumin even more severe than the depletion of albumin in the plasma compartment. The rate of albumin synthesis is increased but not sufficiently to replace losses and restore the serum concentration to normal. The rate of albumin catabolism is decreased. This decrease from the normal catabolic rate is as important as the increased rate of albumin synthesis in maintenance of albumin homeostasis in nephrosis. Whereas the reduced serum oncotic pressure certainly contributes to edema formation, sodium retention may result from processes intrinsic to the kidney itself; and plasma volume may actually be expanded despite hypoalbuminemia. The hyperlipemia that occurs in nephrosis is due to a combined defect in lipoprotein metabolism: increased hepatic synthesis of VLDL and decreased removal of TG and highly atherogenic remnants of incompletely metabolized CMs. The defects in lipoprotein metabolism may in part be the end result of the urinary loss of highly negative-charged macromolecules of the mucopolysaccharide called orosomucoid, which carries with it heparan sulfate, and important cofactor for LPL.
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PMID:Mechanisms and consequences of proteinuria. 351 85

The main lipoprotein density classes, namely very-low-density lipoproteins (VLDL), intermediate-density lipoproteins (IDL), low-density lipoproteins (LDL), high-density lipoproteins2 (HDL2) and HDL3 were investigated with respect to their influence on hepatic lipase (HTGL) activity in vitro. Lipoproteins from pooled normal plasma (NP) and from pooled hyperlipemic plasma (HP) were prepared by means of sequential ultracentrifugation. Hepatic lipase was determined radioenzymatically after preincubation with protamine sulfate. It could be demonstrated that IDL from HP were able to stimulate HTGL activity by approximately 100% above the baseline value. HDL3 from both NP and HP revealed an inhibiting effect on HTGL activity. VLDL, LDL, and HDL2 exhibited no significant effect on HTGL activity. It is speculated that HTGL could possibly represent a second pathophysiological pathway for the catabolism of IDL in hyperlipemia but this presumption is supported by only a few investigations in vivo.
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PMID:Stimulating effect of intermediate-density lipoproteins (IDL) from hyperlipemic plasma on hepatic lipase. 372

The prevalence of hypertension among Kazak, Han, and Uygur nationalities living in Xinjiang Autonomous Region was 15.3%, 4.2%, and 2.1%, respectively; 257 men (92, 92, 83 subjects, respectively), aged 40-59 years were studied. The variables analyzed were serum total cholesterol, total protein, albumin, alpha-GT, triglyceride, plasma fibrinogen, and glucose concentrations; and urinary Na, K, Ca, Mg, urea nitrogen, taurine, sulfate, and NaCNS (an index of smoking), content. The data on nutritional variables indicated that Kazak subjects have a higher intake of sheep meat and milk, add salt to milk and tea, and take little starchy food, fresh fruits, and vegetables, as compared with Han and, especially, Uygur subjects. Statistical analysis showed Na intake (Na/K) exerted a prehypertensive effect; Ca (Ca/Mg) was implicated in blood pressure regulation; an antihyperlipidemic factor may exist in the Kazak diet; animal protein is correlated with elevated blood pressure; alcohol consumption may contribute to hypertension; and a mosaic model of metabolic disturbances, including high blood pressure, high blood sugar, impaired fibrinolytic activity, and hyperlipidemia, appear to exist.
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PMID:Nutrition, metabolism, and hypertension. A comparative survey between dietary variables and blood pressure among three nationalities in China. 376 Sep 14

We compared the Du Pont aca (phosphotungstate-enzymic cholesterol) and the Dow (dextran sulfate/Mg2+-enzymic cholesterol) methods for the determination of high-density lipoprotein cholesterol (HDLC) and total cholesterol in serum from 113 patients. The aca results for both total cholesterol and HDLC were significantly greater (p less than 0.0001) than the Dow results, the aca method overestimating the HDLC concentration (mean recovery 107.2% in serum samples with values assigned by the Centers for Disease Control). The precision of the aca method for HDLC was essentially the same as that of the Dow method. Bilirubin (up to 0.17 g/L), hemoglobin (up to 4 g/L), and slight lipemia (triglycerides up to 5.4 g/L) did not interfere with the aca method.
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PMID:Comparison of the Du Pont aca and Dow methods for determination of high-density lipoprotein cholesterol. 619 5

We analyzed the heterogeneity of apo E in very low density lipoprotein from 58 hyperlipidemic subjects with or without atherosclerosis, 69 patients with ischemic heart disease, and 100 apparently healthy individuals. Apo E gene frequencies in the group of healthy individuals were comparable with those in German and American populations. The distribution of six common apo E phenotypes in the groups of hyperlipidemia and ischemic heart disease was similar to that in the healthy group. In addition to the three major isoforms of apolipoprotein E (apo E-4, E-3, and E-2) and the new one (apo E-5) which was recently found in this laboratory, we have discovered an additional series of components, which showed themselves as at least three bands on an isoelectric focusing gel in the region of E-VII through E-V, in four patients with hyperlipidemia and atherosclerosis. The new series of apo E components, named apo E-Suita, was identical with the ordinary apo E in its interaction with heparin-Sepharose gel and with anti-apo E antibody. The most basic component of apo E-Suita (E-VII) was the unsialylated form and other components (E-VI and E-V), the sialylated forms. Family studies revealed that apo E-Suita was determined by inheritance of a new apo E allele located at the same locus as the hitherto known apo E components. Apo E-5 and apo E-Suita isoproteins had isoelectric points more basic than apo E-3, the parent type, by two and four units of charge, respectively. While the apo E-Suita isoprotein had the same molecular weight as ordinary major apo E isoproteins, the molecular weight of the apo E-5 isoprotein was approximately 1,500-2,000 lower than the other apo E isoproteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The incidence of abnormal apo E components, including apo E-5 and apo E-Suita, was high among patients with hyperlipidemia and ischemic heart disease (7:127), while we could not find such components among 100 healthy individuals. Moreover, five of seven patients with the abnormal apo E had overt atherosclerotic disease. The findings suggest that these kinds of apolipoprotein mutation are closely related to the development of atherosclerosis.
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PMID:New mutants of apolipoprotein E associated with atherosclerotic diseases but not to type III hyperlipoproteinemia. 648 Aug 26

We have previously reported that normal Wistar rats fed an isocaloric, sucrose-rich (63%) diet (SRD) developed glucose intolerance and elevated triglyceride levels in plasma as well as in heart and liver tissue. This metabolic state was accompanied by hyperinsulinism both in vivo and in vitro, suggesting that a state of insulin resistance has developed. The aim of this study was to gather information on the various plasma post-heparin lipolytic activities in rats fed a SRD. Hepatic triglyceride lipase (H-TGL) was evaluated by both, protamine sulfate inhibition (PSI) of extrahepatic lipoprotein lipase (LPL) and heparin-Sepharose affinity chromatography (H-SAC). Both methods rendered comparable results. Total triglyceride lipase (T-TGL) was measured after Krauss et al. and monoglyceride hydrolase (MGH) after Vogel et al. Our results have shown a significant decline of plasma T-TGL (5.32 +/- 0.34 means +/- SEM vs. 7.48 +/- 0.64 mumol glycerol ml-1 h-1; p less than 0.01), H-TGL (3.71 +/- 0.28 vs. 5.05 +/- 0.69; p less than 0.05), LPL (1.61 +/- 0.26 vs. 2.42 +/- 0.41; p less than 0.05) and MGH (558 +/- 108 mumol glycerol l-1 min-1 vs. 1,165 +/- 45; p less than 0.001) activities. Thus, feeding a sucrose-rich diet induced a state of hyperlipemia and insulin resistance in which not only plasma T-TGL but also H-TGL and MGH activities were significantly decreased. This suggests that the latter two enzymes are also under nutritional and/or hormonal control.
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PMID:Post-heparin plasma hepatic triglyceride lipase and monoglyceride hydrolase activities in hyperlipemia induced by a sucrose rich diet. 661 28


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