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)

We have investigated the frequencies of 3 restriction fragment length polymorphisms (RFLPs) of the apolipoprotein B (apo B) gene in normo- and hyperlipidaemic individuals. In individuals with type III hyperlipidaemia, the allele frequency for the RFLP detected with XbaI was significantly different from the allele frequency in normolipidaemic individuals and in those with other types of hyperlipidaemia. No significant difference in allele frequency was found among these groups for the RFLPs detected with MspI or EcoRI. Within a sample of 62 normolipidaemic individuals, homozygotes for the X2 allele (cutting site) of the XbaI RFLP had a significantly higher serum cholesterol level than homozygotes for the XI allele, with individuals of the genotype X1X2 having an intermediate value (X2X2 mean 5.71 mmol/l, X1X1 mean 4.81 mmol/l, X1X2 mean 5.30 mmol/l). There were also significant differences in serum triglyceride levels in individuals with different XbaI genotypes. In these normolipidaemic individuals there was no correlation between the EcoRI and MspI RFLP genotypes and levels of any serum lipid variable. Information from the XbaI and EcoRI RFLPs was used in conjunction to define apo B haplotypes. These haplotypes are a more precise measure of the genotypic variation, and they explain a greater fraction of the serum cholesterol and triglyceride levels than the single-site polymorphisms considered separately. This study suggests that variations in the gene for apo B are associated with the determination of serum cholesterol and triglyceride levels both in patients with type III hyperlipidaemia and in the normal population.
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PMID:Apolipoprotein B gene variants are involved in the determination of serum cholesterol levels: a study in normo- and hyperlipidaemic individuals. 289 Mar 59

The efficacy, safety, and tolerability of simvastatin (20 mg twice a day) in the treatment of hyperlipidaemia due to unremitting nephrotic syndrome was compared with that of cholestyramine (8 g twice a day) in a crossover trial in ten patients. Two patients were taken off the protocol, one because he could not tolerate cholestyramine and one because of non-compliance with the cholestyramine regimen. No clinical or laboratory adverse experiences were noticed during the study in the other eight patients. Simvastatin was significantly more effective than cholestyramine in reducing the hyperlipidaemia--it produced a 36% decrease in total cholesterol and a 39% decrease in low density (LDL)-cholesterol, whereas cholestyramine reduced total cholesterol by 8% and LDL-cholesterol by 19%. With simvastatin the apolipoprotein B level decreased by 30%, whereas the apolipoprotein A level increased by 10%.
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PMID:Effects of simvastatin and cholestyramine on lipoprotein profile in hyperlipidaemia of nephrotic syndrome. 290 53

Exogenously labelled Iodine-125-VLDL (very low density lipoprotein) was given intravenously to twelve dialysis patients and four normal controls. Specific activities of I-125-VLDL apoB (apolipoprotein B) and I-125-IDLapoB (intermediate density lipoprotein apolipoprotein B) were measured for forty-eight hours. Synthesis rates (flux) and fractional catabolic rates (FCRs) of VLDLapoB and IDLapoB for hyperlipidemic (n = 8), normolipidemic (n = 4) dialysis patients and controls (n = 4) were calculated. Dialysis patients had lower VLDLapoB FCRs than controls (p less than 0.05); hyperlipidemic dialysis patients had marginally raised VLDLapoB flux over normolipidemics (p = 0.0508), suggesting apoB production might play a greater role in the pathogenesis of hyperlipidemia. Hyperlipidemics had lower IDLapoB FCRs than controls (p = 0.01). IDLapoB flux was similar in all three groups. The discrepancy in VLDLapoB fluxes between hyperlipidemics and normolipidemics with similar IDLapoB fluxes suggested that VLDLapoB could be directly catabolized in hyperlipidemics. ApoB concentration was increased in VLDL, IDL of hyperlipidemics when compared with normolipidemics (p less than 0.05) and controls (p = 0.01). Hyperlipidemic VLDL plasma levels were relatively enriched with cholesterol when compared with controls, p less than 0.01, and normolipidemics, p less than 0.05. These factors might all contribute towards accelerated atherogenesis in hyperlipidemic dialysis patients.
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PMID:Apolipoprotein B turnover in dialysis patients: its relationship to pathogenesis of hyperlipidemia. 292 Apr 72

Thirteen patients with severe acne were treated for 16 weeks with 1.0 mg/kg/day isotretinoin. There were significant increases in serum cholesterol (P less than 0.02), triglycerides (P less than 0.02) and apolipoprotein B (P less than 0.02). No changes were found in serum apolipoprotein A-1, non-esterified fatty acids (NEFA), carnitine, lactate, pyruvate, glycerol, alanine, beta-hydroxybutyrate, glucose or insulin. We therefore found no evidence that the hyperlipidaemia of isotretinoin therapy is due to increased fluxes of NEFA from adipose tissue to the liver, although we cannot exclude the possibility that there are changes in the proportion of NEFA being esterified to triglyceride or undergoing beta-oxidation. We suggest that the hyperlipidaemia induced by isotretinoin may be due to an increase in circulating lipoprotein from increased production or impaired catabolism.
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PMID:Isotretinoin and serum lipids: studies on fatty acid, apolipoprotein and intermediary metabolism. 295 78

We have used four independently isolated cDNA probes for human apolipoprotein B (apo B), to isolate overlapping genomic recombinants for the 3' portion of the apo B gene. The cDNA clones and a unique fragment from the genomic recombinant have been used to identify the human apo B gene in DNA from a series of rodent X human somatic cell hybrids. Our results provide evidence for the assignment of this gene to the short arm of human chromosome 2 (p23-pter). We have used the cDNA probes to identify three common DNA polymorphisms. The first, detected with the restriction enzyme XbaI and our probe pAB4, has a rare allele frequency of 0.48. The other two polymorphisms are detected with the probe pAB3. The enzyme MspI detects at least three alleles, with frequencies of 0.67, 0.16 and 0.15, while that detected with the enzyme EcoRI has a rare allele frequency of 0.12. The relative position of these polymorphisms has been mapped using the genomic recombinants. Investigation of a small number of haplotypes indicates that there is linkage equilibrium between the polymorphisms, which have a total polymorphism information content (PIC) value of more than 0.8. These polymorphisms will provide useful markers for genetic studies on chromosome 2 and for the analysis of the involvement of variants of the apo B gene in the development of hyperlipidaemia.
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PMID:The isolation of genomic recombinants for the human apolipoprotein B gene and the mapping of three common DNA polymorphisms of the gene--a useful marker for human chromosome 2. 301 40

Lovastatin is the first of a new class of cholesterol lowering drugs that competitively inhibit HMG-CoA reductase. This new drug decreases cholesterol synthesis and apolipoprotein B concentrations, and increases LDL receptor activity without adverse effects on other products in the cholesterol pathway. In patients with heterozygous familial or polygenic (non-familial) hypercholesterolaemia, oral lovastatin 20 to 40 mg twice daily reduces plasma total cholesterol and LDL-cholesterol concentrations by 25 to 40% over a period of several weeks. Lovastatin also produces decreases in plasma triglyceride and VLDL-cholesterol concentrations, although to a lesser extent. In addition, small though significant increases in HDL-cholesterol concentrations have been observed. Combined administration of lovastatin with other lipid-lowering drugs results in further reductions in plasma total and LDL-cholesterol concentrations beyond those seen with either drug alone. From findings in short term studies, lovastatin appears to be well tolerated with a low incidence of side effects. However, liver function tests and eye examinations for possible lens opacities are advised, and further long term studies in larger groups of patients are necessary before the side effect profile of lovastatin will be clearly established. As would be expected at this relatively early stage of its clinical 'life,' lovastatin has not yet been studied in a manner that would determine its effect on cardiovascular mortality during long term administration. Nevertheless, if the substantial improvements to patients' lipid and lipoprotein profiles observed in short term studies are maintained during long term administration, then lovastatin will have an important role in the pharmacological management of hyperlipidaemia.
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PMID:Lovastatin. A preliminary review of its pharmacodynamic properties and therapeutic use in hyperlipidaemia. 306 36

The effects of lipid lowering therapy (bezafibrate) on plasma lipoproteins was investigated in twelve patients with familial hypercholesterolaemia (type IIA) and eight with familial combined hyperlipidaemia (type IIB). Bezafibrate caused a decrease of plasma cholesterol, plasma triglycerides, plasma apolipoprotein B, VLDL cholesterol and LDL cholesterol and an increase of HDL cholesterol. Post-heparin plasma lipoprotein and hepatic lipase activities increased in both groups (significant only in type IIB). Lipoprotein composition showed the following changes: Increased protein and phospholipids and decreased triglycerides and cholesteryl esters in VLDL. Decreased protein and triglycerides and increased free and esterified cholesterol in LDL. Decreased triglycerides and increased phospholipids in HDL. Cholesteryl ester to protein ratios decreased in VLDL and increased in LDL. The hydrated density of LDL (both groups) and of HDL3 (type IIB) decreased following bezafibrate therapy. These changes were in general similar to those observed in hypertriglyceridaemic patients and could be ascribed, at least in part, to the increase of plasma lipase activities and the decrease of lipid transfer reactions. Comparing the present data with that previously reported, it was found that bezafibrate caused decreased LDL cholesterol in types IIA and IIB but increased levels in type IV. This change was correlated with the initial plasma triglycerides (r = 0.74, P less than 0.0001) and initial plasma LDL cholesterol (r = 0.66, P less than 0.001). It is concluded that varied response of LDL to therapy reflects a complex interaction of metabolic events, including changing rates of VLDL conversion to LDL, lipoprotein compositional changes and effects of therapy on LDL degradation rates.
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PMID:Change in very low-, low-, and high-density lipoproteins during lipid lowering (bezafibrate) therapy: studies in type IIA and type IIb hyperlipoproteinaemia. 308 75

Retrospective analysis of ulcer healing trials utilizing enprostil, a synthetic dehydroprostaglandin E2 analogue, has demonstrated a 10% or greater reduction in total serum cholesterol in 64%, 64% and 67%, respectively, of hypercholesterolemic subjects receiving the drug in doses of 70 micrograms, 35 micrograms, and 7 micrograms bid, respectively. Only 16% of subjects receiving placebo exhibited a similar reduction (P less than 0.05). The median percent changes for hypercholesterolemic patients receiving enprostil 70 micrograms, 35 micrograms, or 7 micrograms bid, and placebo were -17%, -13%, -11%, respectively, while the median percent change for those on placebo was 0% (P less than 0.05). Eight normocholesterolemic subjects participated in a double-blind crossover study comparing enprostil 70 micrograms/d with its placebo. Nine days of enprostil administration was associated with reductions in total serum cholesterol (-16%) and apolipoprotein B (-16%) and with significant reductions from baseline for LDL-cholesterol (-22%), the LDL/HDL-cholesterol ratio (-13%), and the ratio of serum apolipoprotein B to apolipoprotein A-1 (-12%). Relative to placebo, mean HDL-cholesterol, total triglycerides, and apolipoprotein A-1 concentrations remained unchanged. Daily oral administration of microgram quantities of enprostil is associated with reductions in total cholesterol, LDL-cholesterol, and apolipoprotein B suggesting therapeutic potential of this synthetic prostaglandin for the treatment of hyperlipidemia.
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PMID:Reduction of serum lipoproteins in man by the oral administration of a prostaglandin analogue (enprostil). 313 81

Familial dysbetalipoproteinemia is characterized by hyperlipidemia, increases in beta-migrating, very low density lipoproteins (beta-VLDL), and homozygosity for apolipoprotein E2 (apo E2). In this study, 3 patients with familial dysbetalipoproteinemia were treated with lovastatin, and kinetics for apolipoprotein B (apo B) were determined in control and drug treatment periods. Multicompartmental analyses of apo B kinetics in VLDL and in low density lipoproteins (LDL) were carried out. Lovastatin therapy generally lowered plasma concentrations of apo B and cholesterol in VLDL and LDL. The reductions in concentrations were due mainly to a decrease in transport (production) rates for these fractions. Indeed, the fractional clearance rate (FCR) for LDL-apo B was reduced during lovastatin therapy. The decreased transport rate for VLDL-apo B and LDL-apo B could have been due to an inhibition of the synthesis of lipoproteins containing apo B. An alternate explanation is that lovastatin promoted direct removal of a rapidly-catabolized fraction of VLDL-apo B that is a precursor for longer-lived lipoproteins in the circulation; this mechanism could decrease input rates of identifiable lipoprotein species and retard their clearance because of "saturation" of LDL receptors by more rapidly removed lipoproteins. Finally, both mechanisms, i.e., decreased production and increased clearance of lipoproteins, may have contributed to the fall in VLDL-apo B and LDL-apo B concentrations during lovastatin therapy.
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PMID:Lovastatin therapy in familial dysbetalipoproteinemia: effects on kinetics of apolipoprotein B. 316 80

There is abundant evidence that dietary omega 3 fatty acids effect a favorable change in lipoprotein profiles of normolipidemic individuals. However, there is relatively little information available on the lipoprotein responses of hyperlipidemic individuals at risk for premature coronary artery disease. We studied a group of subjects with familial combined hyperlipidemia (FCHL), as well as a group of normal controls, on three rigidly controlled diets differing primarily in their fatty acid composition. The normal subjects demonstrated significant reductions in total cholesterol, low density lipoprotein (LDL) cholesterol, and total apolipoprotein B (apo B) levels on both an omega 3 (salmon) and omega 6 (safflower) fatty acid-enriched diet when these were compared with a basal diet high in saturated fat. The primary difference in response to the polyunsaturated diets was the potent triglyceride-lowering effect of the salmon diet. The FCHL subjects demonstrated a response to the safflower diet similar to that observed in normals and also manifested a marked triglyceride lowering with the salmon diet. However, total cholesterol and total apo B levels were not lowered by the salmon diet, and LDL cholesterol and apo B levels exhibited an upward trend. Thus, individuals with FCHL, a common disorder associated with premature coronary artery disease, do not appear to have a favorable lipoprotein response to diets enriched in omega 3 fatty acids.
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PMID:The effects of omega 3 and omega 6 fatty acid-enriched diets on plasma lipoproteins and apoproteins in familial combined hyperlipidemia. 318 85


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