Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human heart lipoprotein lipase was purified by affinity chromatography on heparin-Sepharose 4B. When crude extracts of heart acetone powder were applied to columsn, about 40% of total lipase activity was bound to the gel and then eluted with 1.5 M NaCl. At this stage the eluted enzyme was purified 1900-fold. Disc gel electrophoresis yielded a single protein band corresponding with lipolytic activity. Minimum molecular weight of the protein was 60,000 as determined by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The purified enzyme was highly unstable; however, its activity could be partially stabilized at --20C by bovine serum albumin, glycerol, or ethylene glycol. The activity of the purified enzyme (i) had a pH optimum between 7.8 and 8.0; (ii) required serum for full enzymatic activity; apoC-II could be substituted for serum; (iii) was inhibited by by apoC-I in the presence of activated substrate; (iv) was markedly inhibited by NaCl; and (v) was stimulated by heparin.
Atherosclerosis
PMID:Purification and characterization of lipoprotein lipase from human heart. 0 61

A new technique is described for the measurement of the self-diffusion coefficients of protein macromolecules in solution. The method makes use of the phenomenon of Taylor dispersion of a solute introduced into a solvent flowing in the laminar regime through a tube of circular section. Results are reported for the self-diffusion coefficient of cholesterol associated with lipoprotein molecules in dogs' serum at pH 7.4 in the temperature range 18-37 degrees C. The diffusivity of bovine serum albumin in serum has also been studied as a function of temperature at pH 7.4 and 4.7. In the more basic solution, measurements of the diffusivity as a function of protein concentration substantially agree with earlier work. For all the systems studied the diffusivity varies rapidly with temperature. The pH of the solution, in the case of bovine serum albumin, also has a significant effect on the diffusivity of the macromolecule. The latter observation is related to the amount of water bound to the protein molecule in solution.
Atherosclerosis
PMID:Diffusion coefficients for protein molecules in blood serum. 1 75

The binding of chlorophenoxyisobutyric (CPIB), tibric (TA) and nicotinic (NA) acids and CPIB ethyl ester (Clofibrate), TA and NA isopropyl esters (TAPE and NAPE) to human lipoproteins of low density of different classes (LDL2, LDL1 and VLDL) and high density (HDL) were studied by equilibrium dialysis and Sephadex gel filtration. Clofibrate and TAPE bound strongly to lipoproteins, but their acids, CPIB and TA and also NA and NAPE, did not bind. In the same experimental conditions, Clofibrate and TAPE bound only weakly to human serum albumin (HSA) and CPIB bound to HSA with a Ka of 3.3 X 10(5) M(-1) for 1 site of high affinity. The Clofibrate and TAPE bound to lipoproteins did not dissociate either during dialysis or during filtration on Sephadex G 25. The binding percentage remained constant for all drug concentrations studied, and the molar ratio of bound drug rose linearly with increasing concentrations. This suggests that the interaction may be irreversible, and there is some evidence that binding may induce irreversible changes in the lipoprotein molecules. These results, and those already found in experiments made with three other drugs related to Clofibrate, lead to the proposal that in their interaction with lipoproteins, the phenyl groups are necessary and the esterification is contributory. The possible role of this interaction in the lipid-lowering effect of the drugs is discussed with special reference to their possible implication in lipoprotein synthesis within the intestinal and hepatic cells.
Atherosclerosis
PMID:Binding to plasma lipoproteins of chlorophenoxyisobutyric, tibric and nicotinic acids and their esters: its significance for the mechanism of lipid lowering by clofibrate and related drugs. 18 31

It was shown that the action of phospholipase A2 on low density serum lipoproteins (LDL) in the presence of serum albumin led to decrease in the floatation coefficient. Lipase hydrolyzed LDL triglycerides after pretreatment of the latter with phospholipase A2. Due to the action of lipases the LDL residue loses its solubility and the cholesterol-rich precipitate forms. The loss of solubility of lipoproteins treated with lipases and proteinases may occur in vivo, underlying athermao formation, i.e. can thus serve as one of the factors in the pathogenesis of atherosclerosis.
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PMID:[Action of lipases on low-density serum lipoproteins]. 19 43

The nephrotic syndrome may be associated with several complications caused by severe proteinuria. The consequences of severe renal protein loss are disturbances of water and electrolyte metabolism, thromboses and thromboembolic complications, hyperlipidemia with accelerated atherosclerosis and, finally, some other complications due to the decreased oncotic pressure and the renal loss of transport globulins and immunoglobulins. Diagnosis and treatment of these complications are important in the management of patients with nephrotic syndrome. In the present study, the frequency and localization of thromboses and thromboembolic complications in 11 patients with nephrotic syndrome are described. In addition, factors which are known to be responsible for the hypercoagulable state in nephrotic syndrome were evaluated and correlated to the thromboembolic complications in these patients. An important finding was that in all patients with thromboses and thromboembolic complications, the serum albumin concentrations were below 2 g/100 ml, whereas, with one exception, serum albumin levels were above 2 g/100 ml in cases without thromboembolic complications. Our results indicate that serum albumin levels may be used as an indirect parameter to assess the risk of thromboembolic complications in patients with nephrotic syndrome.
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PMID:[Complications of nephrotic syndrome with special reference to thromboembolic accidents]. 37 Sep 77

The effect of immunological injury upon the early in vivo changes in aortic connective tissue metabolism was studied. It was found that a single antigen (bovine serum albumin), when administered in multiple doses, activated collagen synthesis and increased the rate of lgycosaminoglycan synthesis in the arterial wall. The degree of stimulation of both connective tissue components was higher in animals receiving a higher dose of antigen.
Atherosclerosis 1979 Apr
PMID:Biosynthesis of aortic collagen and glycosaminoglycan following immunological injury. 46 20

In the present investigations, the effects of platelet factors on DNA-synthesis by human arterial and venous smooth muscle and venous endothelial cells were compared. Also studied was the role of such factors in restimulating quiescent endothelial cultures and in endothelial reaction to injury. Aortic smooth muscle cells grown in medium containing 10% human serum prepared from plasma poor in platelets (PPPS) reached 9.7%+/-SE 0.65 labelling index when continuously exposed to [3H] thymidine (1 muCi/ml). When lysate from gel-filtered platelets was added, the index was 19.4% +/- SE 1.13 (P less than 0.01) and in the presence of serum derived from platelet rich plasma (PRPS) it reached 24.6% +/- SE 1.22 (P less than 0.01). Similar results were obtained with smooth muscle cells from umbilical veins. In constrast, platelet factors did not significantly affect DNA-synthesis in endothelial cultures. They reached 25.6% +/- SE 1.97 when grown in medium containing PPPS as compared to 21.9% +/- Se 2.53 (P greater than 0.05), when exposed to PRPS. The ability of sera to stimulate DNA-synthesis in endothelial cultures rendered quiescent by 24 h exposure to medium containing 1.4% serum albumin (labelling index 1.83% +/- SE 0.14) was not affected by platelet factors. Platelet lysates alone were not sufficient to restimulate the quiescent cells (labelling index 3.03% +/- SE 1.06) (P greater than 0.05). Platelet factors did not affect the proliferative response following experimental mechanical injury to endothelial monolayers in vitro. We conclude that while platelet factors are essential for human vascular smooth muscle cells to achieve optimal growth, they are not indispensable for endothelial cell proliferation. It is suggested that these cellular differences in growth requirements may play an important role in human atherogenesis.
Atherosclerosis 1978 May
PMID:Platelet factors and the human vascular wall: variations in growth response between endothelial and medial smooth muscle cells. 67 11

The aim of this study was to examine in detail the lipid and apoprotein concentrations in the serum of rats treated with pharmacologic doses (5 mg/kg/d for 5 d) of the synthetic estrogen derivative ethinyl estradiol. The results show that in rats, estrogen-induced hypolipidemia is associated with a nearly complete absence of the lipid and protein moieties normally found in d less than 1.21 fraction of serum. Quantitation of specific apolipoproteins by immunoelectrophoresis show that most apolipoproteins are decreased by more than 90% in the serum of estrogen-treated rats. In contrast to the changes in d less than 1.21 lipoproteins, estrogen treatment only slightly reduced serum phospholipid concentrations (by only 10%) and caused no change in the concentration of serum albumin. The results show that the ethinyl estradiol-treated rat is an excellent model of drug-induced hypolipidemia.
Atherosclerosis 1978 Aug
PMID:Pharmacologically induced hypolipidemia. The ethinyl estradiol-treated rat. 70 87

Normal and atherosclerotic rabbit aortas were perfused at physiological pressure for 1 hour with media containing various concentrations of [3H]oleic acid, between 0.5 and 2.0 mmoles/l, complexed to a fixed concentration 40 g/l of bovine serum albumin (BSA). The mass of free fatty acid (FFA), which entered the arterial wall and was subsequently utilised for lipid synthesis, was calculated from the measured specific activities of FFA in the perfusates. In normal tissue, at all concentrations of FFA in the perfusate, the highest rates of utilisation of perfusate FFA for arterial lipid synthesis were for phospholipids (PL) and triglycerides (TG), with only about 2% in cholesteryl esters (CE). In atherosclerotic tissue, at both low and high concentrations of perfusate FFA, about 25% of fatty acid entering arterial lipids was in CE. When the concentration of FFA in the perfusion medium was raised, the mass of FFA from the medium that was incorporated in the total arterial lipids, increased in both normal and atherosclerotic tissue. The increase was due in normal tissue, to significant increases in incorporation into FFA, lecithin (PC), phosphatidyl inositol (PI), phosphatidyl ethanolamine (PE), TG and CE, whilst in atherosclerotic tissue it was due to increased incorporation into PC, PI, TG and CE. The results suggest that raised concentrations of FFA in blood may increase the rate of synthesis of lipids in normal and atherosclerotic tissue and thus exacerbate the accumulation of certain lipids such as cholesteryl esters, in fatty streak lesions of atherosclerosis.
Atherosclerosis 1978 Dec
PMID:Effect of concentration of perfusing free fatty acid on arterial lipid synthesis in perfused normal and atherosclerotic rabbit aortas. 72 41

Autoimmune hyperlipidemia (AIH) may be induced a variety of antibodies which inhibit different stages of the lipolytic process by which the lipid load is removed from the circulating lipoproteins. In a patient having a monoclonal gammopathy and a nephrotic syndrome with a glomerulonephritis and a marked hypertriglyceridemia, it was found previously that the monoclonal IgG gamma Lac. reacted with human VLDL as well as with human serum albumin. Here it is demonstrated that the purified IgG gamma inhibits the lipolysis of triglyceride substrates by reacting with a substance (Lac. S) necessary for lipoprotein lipase activity. The interaction of IgG lambda Lac. with serum or HDL-activated triglyceride substrates inhibits the lipolytic activity of human and rat plasma post heparin and also adipose tissue lipases. It slightly inhibits the activity of swine pancreatic lipases. The Lac S. which reacts with IgG Lac. is associated to whole and delipidated VLDL and HDL and not to LDL or purified APo-A. It may be an Apo-C or a non-peptidic co-factor of the lipases which remains bound to the apoprotein core after delipidation. Its lack of species specificity and its presence as traces in HSA preparations favors the latter hypothesis. The Lac. substances is different from the Pg and As substances which were found to react with IgA anti-Pg and IgG anti-As antibodies in previously reported antilipoprotein AIH.
Atherosclerosis 1977 Jan
PMID:Inhibition of lipoprotein lipase activity by a monoclonal immunoglobulin in autoimmune hyperlipidemia. 83 49


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