| 1. |
- Bergström, Erik, et al.
(author)
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Serum lipid values in adolescents are related to family history, infant feeding, and physical growth.
- 1995
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In: Atherosclerosis. - 0021-9150 .- 1879-1484. ; 117:1, s. 1-13
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Journal article (peer-reviewed)abstract
- Total serum cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), apolipoprotein A-I (apo A-I), apolipoprotein B (apo B), and lipoprotein (a) (Lp(a)) were analysed in 879 14- and 17-year-old healthy adolescents (477 boys and 402 girls), and related to family history of cardiovascular disease, early feeding, weight and length at birth, and physical growth during infancy and childhood. Mean TC was significantly higher in girls than in boys (4.4 and 4.2 mmol/l, respectively, both age-groups together). High TC values ( > 5.2 mmol/l) were more prevalent in girls than in boys: 14% and 17% compared to 6% and 12% in 14- and 17-year-old girls and boys, respectively. Mean TC and LDL-C values were lower during mid-puberty in both boys and girls while, in boys but not in girls, mean HDL-C values decreased and TG values increased successively with increasing pubertal stage. Girls who were taking oral contraceptives had higher mean values of TC (4.91/4.39 mmol/l), TG (1.32/0.83 mmol/l), and apo B (0.89/0.73 g/l). Boys with a family history of early deaths ( < 55 years) from myocardial infarction and girls with a family history of cerebral haemorrhage/thrombosis in fathers had higher mean values of TC (4.55/4.17 and 5.03/4.40 mmol/l, for boys and girls, respectively), LDL-C (2.84/2.47 and 3.08/2.56 mmol/l), and apo B (0.73/0.70 and 0.86/0.73 g/l). Adolescents with short duration of breast feeding ( < 6 months), or early introduction of infant formula, had higher mean values of TC (4.29/4.14 mmol/l) and apo B (0.72/0.68 g/l). There were no significant correlations between serum lipid values and body weight or length at birth, but adolescents with high LDL-C (upper quartile) seemed to have lower attained heights during infancy and childhood. In conclusion, this study shows that serum lipids in adolescence are primarily related to age and sex but also to early determinants like family history of cardiovascular diseases, infant feeding, and early physical growth.
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| 2. |
- Hultin, M, et al.
(author)
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Conversion of chylomicrons into remnants.
- 1998
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In: Atherosclerosis. - 0021-9150 .- 1879-1484. ; 141 Suppl 1, s. S25-9
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Journal article (peer-reviewed)abstract
- The turnover of chylomicrons in the blood is the sum of several processes. The native chylomicron is synthesized in the intestine out of available substrates. When the chylomicron enters the circulation exchanges of apolipoproteins with other lipoproteins, it also binds to the vascular endothelium where the chylomicron is lipolyzed by lipoprotein lipase. After a short period in the circulation the chylomicron/chylomicron remnant appears to be available for receptor mediated uptake. In this paper several of the processes involved in generation and clearance of chylomicron remnants are discussed.
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| 3. |
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| 4. |
- Lindberg, Gunnar, et al.
(author)
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Serum sialic acid and sialoglycoproteins in asymptomatic carotid artery atherosclerosis. ARIC Investigators. Atherosclerosis Risk in Communities
- 1999
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In: Atherosclerosis. - 1879-1484. ; 146:1, s. 65-69
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Journal article (peer-reviewed)abstract
- Serum total sialic acid (S-TSA) is a recently identified risk marker for atherosclerosis and cardiovascular mortality. The purpose of this study was to evaluate the influence of three sialic acid rich glycoproteins (orosomucoid, haptoglobin, and alpha1-antitrypsin) on the relationship between S-TSA and carotid atherosclerosis. The mean S-TSA was 0.045 g/l higher among cases than controls (P<0.001) in 310 45-64 year-old male and female pairs of carotid atherosclerosis cases and disease-free controls from the Atherosclerosis Risk in Communities (ARIC) Study. Also mean serum levels of the glycoproteins were significantly higher in cases compared to controls. In a conditional multiple logistic regression model with the glycoproteins as independent variables, orosomucoid was correlated most strongly with case control status. However, when incorporated into the mathematical model, S-TSA not only contributed additional information as to the risk of atherosclerosis; none of the three glycoproteins contributed further once S-TSA had been accounted for. Thus, some other source of serum sialic acid or variations in the degree of sialylation of glycoproteins may be essential for understanding the relation between S-TSA and atherosclerosis.
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| 5. |
- Lindén, Tomas, et al.
(author)
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Serum lipids, lipoprotein(a) and apo(a) isoforms in patients with established coronary artery disease and their relation to disease and prognosis after coronary by-pass surgery.
- 1998
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In: Atherosclerosis. - : Elsevier Ireland Ltd. - 0021-9150 .- 1879-1484. ; 137:1, s. 175-86
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Journal article (peer-reviewed)abstract
- Consecutive patients (n=964) undergoing coronary angiography were studied and compared with a random population sample regarding serum lipids and lipoproteins with focus on lipoprotein(a) (Lp[a]) levels and apo(a) isoforms. The patients were also followed for 5 years after the angiography, and the prognostic value of serum lipoproteins were analyzed. The patients were divided in two groups: Group 1 (n=814) consisted of patients with angina pectoris and at least one coronary artery with 50% stenosis and group 2 (n=150) patients with none of the coronary arteries significantly obstructed ( < 50%). As controls a random population sample was selected (n=197). Blood samples were collected before coronary angiography for determination of serum lipids, Lp(a) and isoforms of apo(a). When group 1 and group 2 patients were compared, group 1 was found to have higher serum cholesterol, triglycerides, apoB and Lp(a) as well as lower HDL and apoAI. When group 1 was compared with the random sample, after correction for age and sex, similar differences were observed, except that the difference in Lp(a) was not significant. The high Lp(a) levels among patients was found to be primarily due to the female patients, where the difference compared to both group 2 and controls was highly significant (P=0.007 and P=0.001, respectively). There was a significant difference in the apo(a) isoform distribution between group 1 patients and control subjects (P=0.0003), with a higher frequency of low molecular weight isoforms among patients. This was also significant for the male subgroup (P=0.001). Lp(a), LDL, total cholesterol, triglycerides. apoB, HDL and apoAI were significantly related to the number of major coronary arteries with > 50% stenosis. Mortality during follow-up was,in a univariate analysis, significantly correlated to several factors related to the degree of heart disease and to LDL (P=0.02) and apoB (P < 0.01). Increased mortality was, however, related to low levels of apoB and LDL. For cardiac mortality no significant correlation to lipoprotein variables were found. In conclusion established lipoprotein risk factors were more frequent among patient with angina pectoris and verified coronary stenosis. Furthermore high Lp(a) levels and a high frequency of low molecular weight isoforms of apo(a) were found in coronary patients. Higher Lp(a) levels were observed both for female and male patients, the differences were, however, significant only for the female patients. None of the lipoprotein variables could predict coronary death during the follow-up period.
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| 6. |
- Ohrvall, M, et al.
(author)
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The serum cholesterol ester fatty acid composition but not the serum concentration of alpha tocopherol predicts the development of myocardial infarction in 50-year-old men : 19 years follow-up.
- 1996
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In: Atherosclerosis. - : Elsevier BV. - 0021-9150 .- 1879-1484. ; 127:1, s. 65-71
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Journal article (peer-reviewed)abstract
- A low serum tocopherol concentration and a low proportion of linoleic acid in plasma cholesterol esters have been reported to be associated with coronary heart disease. This study was undertaken to evaluate the predictive importance of the serum cholesterol ester fatty acid composition and serum tocopherol concentration in addition to established risk factors for myocardial infarction. The study comprised 2322 fifty-year-old men who participated in a health survey in 1970-1973 regarding risk factors for coronary heart disease. The proportions of myristic, palmitic, palmitoleic, and dihomogammalinolenic acid were significantly higher in 1970-1973 in subjects who suffered myocardial infarction during the following 19 years, while the proportion of linoleic acid was lower, than in those who remained healthy. Serum tocopherol did not differ significantly between the groups. LDL/HDL ratio, systolic blood pressure, and arachidonic acid/dihomogammalinolenic acid ratio were significant independent discriminators between cases and controls in a stepwise logistic regression analysis. This study suggests that middle-aged men who later develop a myocardial infarction are characterized not only by conventional risk factors but also by an altered fatty acid composition of serum cholesterol esters, with a low arachidonic to dihomogammalinolenic acid ratio, indicating reduced delta 5 desaturase activity. This may imply that changes in the quality of dietary fat intake, or an altered capacity to metabolize fatty acids in the body, could precede the development of coronary heart disease.
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| 7. |
- Peacock, Rachel E., et al.
(author)
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Associations between lipoprotein lipase gene polymorphisms and plasma correlations of lipids, lipoproteins and lipase activities in young myocardial infarction survivors and age-matched healthy individuals from Sweden
- 1992
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In: Atherosclerosis. - : Elsevier BV. - 1879-1484 .- 0021-9150. ; 97:2-3, s. 171-185
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Journal article (peer-reviewed)abstract
- Association studies were carried out on a sample of 87 patients from Sweden who had survived a myocardial infarction (MI) at a young age and 93 age-matched healthy individuals, to compare the impact of polymorphisms (PvuII, HindIII and Serine447-Stop) at the lipoprotein lipase (LPL) gene locus on among-individual differences in plasma lipid traits and progression of atherosclerosis. Significant linkage disequilibrium was detected between any two of these polymorphisms, with the Stop447 allele being only found on the same chromosome as the rare alleles (no cutting sites) of the PvuII and HindIII polymorphisms. In the healthy individuals, weak associations were found between genotypes of the HindIII polymorphism and triglycerides and the PvuII polymorphism and high density lipoprotein cholesterol explaining 7.4% and 5.6% of sample variance (P = 0.03 and 0.09), respectively. No associations were found between these traits and genotypes of the Serine447-Stop substitution, and thus it is unlikely to be the cause of the associations seen with the PvuII and HindIII polymorphisms even though it truncates the enzyme amino acid sequence. The presence of the rare allele, H-, of the HindIII polymorphism was associated with a smaller variance in triglycerides and both cholesterol and triglycerides in the very low density lipoprotein fraction, and with larger interdependent variation between these lipid traits, and also between LPL activity and these lipid traits. This implies that the H- allele, rather than the Stop447 allele, has the major impact on interdependence between traits which are directly or indirectly influenced by LPL activity. In the healthy individuals who were carriers of the apolipoprotein E2 allele, the inter-dependence between LPL activity and lipid traits was significantly smaller, and that between high density lipoprotein cholesterol and both cholesterol and triglycerides in the very low density lipoprotein fraction was much larger compared with non-carriers (P < 0.05). No significant associations were found between lipid traits or lipase activity and genotypes of the Serine447-Stop substitution. However, in the patients, global severity of coronary atherosclerosis at the first angiography was significantly associated with haplotype combinations of the HindIII and the Serine447-Stop polymorphisms, with the H-Stop haplotype being associated with the highest median score (P = 0.02). The data suggest that variation at the LPL gene locus is associated with a pleiotropic effect, that is not directly mediated by changes in lipids, on severity of coronary atherosclerosis.
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| 8. |
- Siegel, G, et al.
(author)
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Physicochemical binding properties of the proteoglycan receptor for serum lipoproteins
- 1999
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In: Atherosclerosis. - 0021-9150 .- 1879-1484. ; 144, s. 59-67
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Journal article (peer-reviewed)abstract
- Proteoheparan sulfate can be adsorbed to a methylated silica surface in a monomolecular layer via its transmembrane hydrophobic protein core domain. Due to electrostatic repulsion, its anionic polysugar side chains are stretched out into the blood substitute solution representing a co-receptor for specific lipoprotein binding through basic amino acid-rich residues within their apolipoproteins. The binding process was studied by ellipsometric techniques showing that oxLDL had a deleterious effect on heparan sulfate proteoglycan binding and conformation. Ca2+ binding to and storage on the proteoheparan sulfate/LDL compound formed a 'heterotrimeric' HS-PG/LDL/Ca2+ complex of high stability, aggregability and deposit coating. On the other hand, HDL bound to heparan sulfate proteoglycan protected against LDL docking and completely suppressed calcification of the proteoglycan/lipoprotein complex.
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| 9. |
- Yuan, XiMing, et al.
(author)
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Iron in human atheroma and LDL oxidation by macrophages following erythrophagocytosis
- 1996
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In: Atherosclerosis. - : Elsevier BV. - 0021-9150 .- 1879-1484. ; 124:1, s. 61-73
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Journal article (peer-reviewed)abstract
- The oxidative modification of low density lipoprotein (LDL) has been implicated as an early step in the formation of atheromatous lesions. In vitro studies suggest it to be accelerated, or even initiated, by transition metals such as iron or copper in combination with a reducing agent. Even if such metals have been demonstrated in atheroma gruels, their origin and precise localisation within human atheroma are presently unknown. In the initial part of this study we applied Pearl's method, energy dispersive X-ray microanalysis, and a modified Timm sulphide silver method (SSM) to demonstrate the occurrence of iron in early atherosclerotic lesions from a number of consecutive autopsy cases with evident, general atheromatosis. With the very sensitive SSM, but not with the other techniques, we found foam cells to contain heavy metals with a mainly lysosomal localization. On the basis of the hypothesis that such a lysosomal accumulation of iron might be due to erythrophagocytosis by migrating tissue-bound macrophages that later develop into foam cells, we designed an in vitro model system where human monocyte-derived macrophages were exposed to artificially aged, UV-exposed erythrocytes. The macrophages were then exposed to LDL in serum-and iron-free RPMI medium, occasionally in the presence of the potent iron-chelator desferrioxamine. The capacity of macrophages to oxidise LDL was much enhanced following erythrophagocytosis, and the process was shown to involve secretion of iron. Consequently, LDL oxidation was greatly inhibited by desferrioxamine. We conclude that iron may be exocytosed by macrophages that previously had their lysosomal apparatus enriched with iron, e.g. due to erythrophagocytosis. Oxidation of LDL may result in ensuing foam cell-formation secondary to scavenger-receptor mediated endocytosis by macrophages.
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| 10. |
- Yuan, XiMing, et al.
(author)
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The toxicity to macrophages of oxidized low-density lipoprotein is mediated through lysosomal damage
- 1997
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In: Atherosclerosis. - 0021-9150 .- 1879-1484. ; 133:2, s. 153-61
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Journal article (peer-reviewed)abstract
- Oxidized low-density lipoprotein (ox-LDL) has been shown to degrade poorly within the secondary lysosomes of macrophages but its possible effect on lysosomal integrity has received less attention. The effect of ultraviolet-C oxidized LDL (UVox-LDL) on cellular viability, and lysosomal membrane stability, was examined on cultured murine J-774 cells and human monocyte-derived macrophages (HMDMs). The acridine orange (AO) relocalization test was applied to study the lysosomal integrity of living cells. UVox-LDL dramatically reduced J-774 cell proliferation at a concentration of 25 microg/ml. Incubation with 5 microM copper alone, normally used to induce LDL oxidation, was also toxic. In contrast to the effects of ox-LDL, in concentrations up to 75 microg/ml, native LDL (nLDL) rather stimulated J-774 cell replication. Incubation with UVox-LDL (25-75 microg/ml) also altered cellular AO uptake, depending on time and dose: its lysosomal accumulation decreased and its cytosolic accumulation increased. This shift indicates damaged lysosomal membranes with decreased intralysosomal, and increased cytosolic, H+ concentration. Many J-774 cells exposed to UVox-LDL initially transformed into foam cells and then assumed an apoptotic-type morphology with TUNEL-positive nuclei. We conclude that ox-LDL is cytotoxic to macrophages due to oxidative damage of lysosomal membranes, with ensuing destabilization and leakage to the cytosol of lysosomal contents, such as hydrolytic enzymes, causing degeneration of apoptotic type.
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