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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the last few years many reports have been published concerning shortened platelet half-life in different diseases such as atherosclerosis and hematological disorders. Up to the present moment, however, there is no information available concerning age and sex dependency in healthy people. Therefore, we evaluated platelet half-life in 106 patients, who had been examined because of a suspected atherosclerotic or hematological disorder having been excluded in the sequel. In all the patients we found negative bicycle ergometry and negative sonography of the carotid arteries and the legs. Platelets were labelled with 100 muCi of 111Indium-oxine-sulfate at 37 degrees C for 5 minutes. The mean labelling efficiency was 90%, the recovery about 70% after two hours. We found a statistically significant correlation (r = -0,5395; p less than 0,001 between age and platelet half-life. In male patients we observed a trend towards shortened platelet half-life, however, the differences were not significant.
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PMID:[Age dependency of platelet half life]. 613 Jul 14

As little as 1 microliter of serum-free supernatant from Mo(t), an established lymphocyte line, when added to a 500-microliters incubation of macrophages derived from human monocytes, significantly decreased the receptor-mediated uptake and degradation of three cholesterol-rich molecules: low density lipoprotein (LDL); LDL complexed to dextran sulfate; and LDL modified by malondialdehyde (MDA-LDL). In contrast, the receptor-mediated uptake and degradation of mannosyl bovine serum albumin was increased three-fold. The Mo(t) supernatant did not contain competitive inhibitors of the cholesterol-rich ligands, and it did not alter macrophage receptor-independent endocytosis, protein synthesis, or phagocytosis of heat-killed yeast. The effect of the Mo(t) supernatant was specific for macrophages and was abolished by preincubation of the supernatant with trypsin, which indicates that the active substances are protein in nature. The decrease in the uptake and degradation of MDA-LDL induced by preincubating the macrophages with Mo(t) supernatant appeared to result from a decrease in the number of receptors for this ligand at the cell surface. The isolation of these lymphokines should offer new insights into macrophage receptor-mediated endocytosis, and may yield substances useful in preventing foam cell formation in atherosclerosis.
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PMID:Lymphokines secreted by an established lymphocyte line modulate receptor-mediated endocytosis in macrophages derived from human monocytes. 631 4

The composition of acidic glycosaminoglycans (AGAG) in normal and atherosclerotic human cerebral arteries was studied by enzymatic methods. The main cerebral trunk contained more AGAG than the distal branches. The content and relative proportion of heparan sulfates were greater in normal areas than in those affected, but the reverse was found for dermatan sulfate and chondroitin 6-sulfate. Quantitative changes in AGAG with severity of the disease were compared with those in water and lipid content.
Atherosclerosis
PMID:Acidic glycosaminoglycans, water and lipids in normal and atherosclerotic human cerebral arteries. 643 Mar 8

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 report the detection of a high-molecular-weight protein which is present in the 12,000 X g supernatant of arteriosclerotic plaques from the abdominal aortas of cockerels. The protein has a molecular weight of 160-170 kd when resolved via sodium dodecyl sulfate polyacrylamide gel electrophoresis (7.5%) in the presence of beta-mercaptoethanol. Densitometric scans of silver-stained gels indicate that the 160 kd protein is 8-10 times more prominent in plaques than in the underlying artery wall. This protein, which is present in all plaques analyzed to date, can be detected in animals as young as 8 weeks of age. This represents the first demonstration of the elaboration of a unique protein during the early stages of arteriosclerotic plaque development.
Atherosclerosis 1984 Oct
PMID:Enhanced expression of a high-molecular-weight protein in arteriosclerotic plaques. 649 42

A focal atherosclerotic plaque was induced in the aortas of New Zealand White female rabbits by a balloon injury and an atherogenic diet. Under general anesthesia and systemic heparinization, endarterectomy was performed using the operating microscope. Animals were sacrificed at 5, 10, 20, and 60 min following the endarterectomy and operated aortic segments were perfused and examined using scanning electron microscopy. Each segment was compared to a similar segment of endarterectomized aorta from a normal, nonatherosclerotic rabbit. Thrombus formation including aggregated platelets, red cells, and fibrin was found to be more pronounced in the atherosclerotic segments. Ten more atherosclerotic rabbits underwent identical procedures except that heparin was reversed using protamine sulfate 5 min following the endarterectomy. When these specimens were compared to a similar atherosclerotic group without heparin reversal, it was evident that a tremendous thrombogenic process had taken place in the "reversed" segments. This study suggests that atherosclerosis may alter thrombogenesis following an operative vascular procedure and that early reversal of heparin following an endarterectomy should be viewed with caution.
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PMID:Effect of heparin reversal following endarterectomy in an atherosclerotic animal model. 654 40

Previous studies have indicated that reendothelialized regions of injured rabbit aortas are more susceptible to diet-induced atherosclerosis than persistently deendothelialized regions or uninjured aortas. However, the mechanism responsible for this selective lipid deposition is not understood. One possibility is that these regions differ with respect to the quantity and type of glycosaminoglycan-containing proteoglycans which are known to interact with lipoproteins. To determine whether these regions differed with respect to their glycosaminoglycan composition, the authors divided 53 rabbits into four groups. Groups IA and IB were fed a regular diet beginning 5 weeks prior to aortic deendothelialization; Groups IIA and IIB were fed the same diet supplemented with 0.5% cholesterol. The rabbits were continued on these diets following aortic deendothelialization with a balloon catheter. Those in Groups IA and IIA were sacrificed either at 2-5 weeks or 6-8 weeks following deendothelialization; proteoglycans were assessed morphometrically following staining with alcian blue. Groups IB and IIB were sacrificed at 10 weeks following injury; glycosaminoglycans were extracted from deendothelialized and reendothelialized aortas, separated by electrophoresis, and quantitated by scanning densitometry. Morphometric analysis of stained aortic sections revealed significantly increased quantities of alcianophilic material in the neointima of reendothelialized aortas as compared with deendothelialized aortas in both diet groups. Chemical analysis revealed significantly more of each glycosaminoglycan in reendothelialized aortas when compared with deendothelialized or uninjured aortas. The major glycosaminoglycans present in all regions were heparan sulfate and chondroitin sulfate; and although absolute quantities of these particular glycosaminoglycans increased in the reendothelialized region, their relative percentages remained the same for each area analyzed. Cholesterol feeding did not appear to influence glycosaminoglycan concentration and composition in reendothelialized and deendothelialized regions when compared with normal diets, but cholesterol feeding alone did increase aortic glycosaminoglycans in uninjured aortas. The results suggest that the presence of endothelium influences the quantity and type of glycosaminoglycans accumulating in the neointima, and that the differences in proteoglycans in the reendothelialized artery may account at least in part for the propensity of this area to accumulate lipid and evolve as atherosclerosis.
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PMID:Effect of endothelium on glycosaminoglycan accumulation in injured rabbit aorta. 663 49

Proteoglycans and glycosaminoglycans of the intima-media extracellular matrix have been stated to play a role in lipoprotein deposition associated with atherogenesis. It is therefore important to characterize the active lipoprotein-complexing moiety of these macromolecular aggregates. We have isolated a soluble proteoglycan aggregate of approximately 5 X 10(6) molecular weight after homogenization of human aortic intima-media in an isosmotic sucrose solution, sequential differential centrifugation, dialysis, exclusion chromatography and preparative electrophoresis. This proteoglycan aggregate, labelled lipoprotein-complexing proteoglycan (LCP), has been previously shown to form specific complexes with low density lipoproteins, either isolated or in sera. Density gradient centrifugation in dissociative conditions of the LCP, cellulose acetate acetate electrophoresis of the subfractions, chondroitinases treatment and high performance liquid chromatography of the unsaturated disaccharides indicated that the glycosaminoglycan moiety was composed of 56% chondroitin-6-SO4, 26% hyaluronate and/or undersulfated chondroitin and 17% chondroitin-4-SO4. In pore-gradient polyacrylamide gel electrophoresis, the hyaluronate monomer appeared to have a molecular weight of 250000 while that of the chondroitin sulfates ranged between 50000 and 70000 after extensive treatment with protease. The fractions enriched in the chondroitin sulfate monomers were the most reactive towards LDL and their reactivity was abolished by chondroitinase AC indicating that the lipoprotein-complexing capacity of the LCP aggregate is associated to these molecules.
Atherosclerosis 1983 Dec
PMID:Partial structure of the active moiety of a lipoprotein complexing proteoglycan from human aorta. 666 Dec 68

The interaction of glycosaminoglycans and proteoglycans with low density lipoproteins has been studied. Aortic and cartilaginous glycosaminoglycans are retained in LDL affinity columns and produce turbidity when added to LDL in presence of Ca2+. When extracted from whole aortic walls, dermatan sulfate is the glycosaminoglycan that shows greatest affinity for LDL. However, when using the glycosaminoglycans obtained by papain hydrolysis of the proteoglycans extracted from aorta, the binding affinity with LDL was similar for dermatan sulfate and chondroitin 4/6-sulfate. Removal of the protein core of the aortic or cartilaginous proteoglycans did not prevent interaction with LDL. However, treatment with testicular hyaluronidase abolished totally such interaction. When aortic glycosaminoglycans and proteoglycans were applied to LDL affinity columns in presence of Ca2+, a marked increase in the average molecular weight of the glycans found in the eluates of higher NaCl concentration was observed. This result suggests that the molecular weight of the glycosaminoglycans is a relevant factor for the binding of these compounds to LDL.
Atherosclerosis 1984 Feb
PMID:The binding of human aortic glycosaminoglycans and proteoglycans to plasma low density lipoproteins. 671 67

Dynamics of lipoprotein-glycosaminoglycan interactions in aortas were studied in vivo using the atherosclerotic rabbit model. Severe hypercholesterolemia and atherosclerosis were produced by relatively long-term feeding of a high cholesterol diet. [35S]Sulfate uptake by aorta was measured to assess the sulfated glycosaminoglycan metabolism while the plasma and aorta distribution of 125I-labeled LDL after intravascular injection was determined to monitor aortic LDL uptake and complex formation with glycosaminoglycans. The retention and distribution of LDL as lipoprotein-glycosaminoglycan complexes in different extracellular connective tissue elements were evaluated by extracting the tissues with saline, collagenase and elastase. Hypercholesterolemia with atherosclerosis resulted in a several-fold increase in the uptake of LDL by aorta despite a marked reduction of 125I-labeled LDL in the plasma compartment and in a significant increase in glycosaminoglycan content of aorta coupled with an increased 35S incorporation into glycosaminoglycans. Elastase-solubilized fractions from normal aortas and collagenase-solubilized fractions from atherosclerotic aortas contained maximum labeled and nonlabeled glycosaminoglycan, suggesting alterations in the make-up of fibrous structures of connective tissue matrix in atherosclerosis. Saline extraction and collagenase and elastase digestions solubilized varied proportions of lipoprotein-cholesterol and 125I-labeled LDL, thereby representing different pools of extracellular matrixbound lipoproteins. A tendency for 125I-labeled LDL to increase in collagenase- and elastase-solubilized fractions with time (4 h vs. 24 h) was noted. The occurrence of both lipoproteins and glycosaminoglycan (labeled and nonlabeled) in the ultracentrifugal floating fraction at solvent density 1.063 g/ml demonstrated that the lipoproteins solubilized by different extraction procedures occur in part as lipoprotein-glycosaminoglycan complexes. The specific activities of glycosaminoglycan in the complexes obtained by different extraction procedures differed markedly (elastase greater than collagenase greater than saline), emphasizing the presence of different pools of complexes. Thus, besides arterial cell-mediated processes, extracellular matrix components are important in affecting the retention and accumulation of LDL in atherosclerosis.
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PMID:Dynamics of lipoprotein-glycosaminoglycan interactions in the atherosclerotic rabbit aorta in vivo. 671 64


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