bluuebunny/crossref_metadata_2025 huggingface dataset:
Dietary polyunsaturated fat decreases coronary artery atherosclerosis in a pediatric-aged population of African green monkeys.
Authors: Wolfe M S , Sawyer J K , Morgan T M , Bullock B C , Rudel L L
Published: June 2011

The hypothesis tested was that juvenile African green monkeys consuming diets enriched with n-6 polyunsaturated fat from birth until young adulthood would have significantly less coronary artery atherosclerosis than comparable animals consuming diets enriched with saturated fat. African green monkeys (Cercopithecus aethiops, n = 108) of both sexes were fed atherogenic diets (0.8 mg cholesterol/kcal) throughout their lives so that death at 16, 32, or 60 months of age permitted quantification of atherosclerosis. In the coronary arteries, the average intimal area increased significantly with age (P = .02), showing increases of 28-fold and sevenfold between 32 and 60 months in the saturated fat- and polyunsaturated fat-fed groups, respectively. Young adult male animals at 60 months of age were found to have significantly (P = .03) more coronary artery atherosclerosis than female animals. Animals fed polyunsaturated fat had significantly (P < or = .01) less coronary artery atherosclerosis. By 60 months of age in the animals consuming polyunsaturated fat, the average coronary artery intimal area was one fourth and the average size of the largest coronary intimal lesion was one fifth that in monkeys fed saturated fat. Low-density lipoprotein (LDL) cholesterol and LDL particle size were each found to be positively correlated with coronary artery atherosclerosis end points in both diet groups. In addition to the coronary arteries, atherosclerosis in the abdominal and thoracic aorta and carotid arteries was also evaluated; the coronary arteries were the only arterial system with significantly less atherosclerosis in the polyunsaturated fat group as measured by intimal area. However, evaluation of histological sections of abdominal aorta showed relatively more sterol clefts in the saturated fat-fed group, and more free cholesterol was measured, suggesting that lesions were more complicated in this group. These results show that dietary intervention early in life with n-6 polyunsaturated fat can be effective in decreasing the development of atherosclerosis, particularly in the coronary arteries of primates. This outcome supports the concept that dietary intervention beginning early in childhood can have beneficial effects on the coronary heart disease of later life.
Effect of flow on the process of endothelial cell division.
Authors: Ziegler T , Nerem R M
Published: June 2011

In this study we investigated the effect of flow and the associated shear stress on the process of endothelial cell division. A shear stress of 7 N/m2 (70 dyne/cm2) was applied to a monolayer of bovine aortic endothelial cells (BAECs) by using a parallel-plate flow-chamber system. Dividing cells under flow conditions were qualitatively compared with those under static-culture conditions. In addition, the duration of some phases of the cell cycle (ie, mitosis and cytokinesis) was measured for both static and flow conditions. Dividing BAECs in static cultures bowed upward; however, when cells were preconditioned by at least 6 hours of exposure to flow, they stayed relatively attached to the substrate during the entire process of cell division. Cell area significantly decreased during division for both static-culture and flow conditions. Finally, although significant changes in the duration of phases were observed in single experiments during which cells were exposed to shear stress, any differences disappeared when the data for a large number of cells were combined. Hence, on average, flow and its associated shear stress did not affect the duration of the different phases of endothelial cell division.
Role of common genetic polymorphisms in the LDL receptor gene in affecting plasma cholesterol levels in the general population.
Authors: Ahn Y I , Kamboh M I , Aston C E , Ferrell R E , Hamman R F
Published: June 2011

A large number of rare mutations in the low-density lipoprotein (LDL) receptor gene cause the autosomal dominant disorder familial hypercholesterolemia. In addition, a number of common DNA polymorphisms have been identified in the LDL receptor gene, but their significance in affecting plasma cholesterol levels in the general population has not been studied widely. We investigated the role of two common DNA polymorphisms, Ava II (exon 13) and Nco I (exon 18), at the LDL receptor locus in affecting plasma lipid profiles in normolipidemic Hispanics (n = 385) and non-Hispanic whites (NHWs; n = 543) from the San Luis Valley, Colorado. While the distribution of the Nco I polymorphism was comparable between Hispanics and NHWs, the allele frequencies at the Ava II restriction site differed significantly between the two ethnic groups (P < .001). The Ava II and Nco I polymorphisms were in linkage disequilibrium (P < .05) in both Hispanics and NHWs. Both polymorphisms revealed a gender-specific effect on total and LDL cholesterol (LDL-C) confined to women only in both ethnic groups. The AVA II polymorphism was associated significantly with total cholesterol and LDL-C in NHW women (P = .001 and P = .014) and in Hispanic women (P = .011 and P = .057). The effect of the Nco I polymorphism was significant on total cholesterol and LDL-C (P = .019 and P = .035) in Hispanic women only. Although a similar trend was observed in NHW women, the effect was not significant at the 5% level.(ABSTRACT TRUNCATED AT 250 WORDS)
Hemostatic factors in the Coronary Artery Risk Development in Young Adults (CARDIA) Study.
Authors: Green D , Ruth K J , Folsom A R , Liu K
Published: June 2011

Elevated levels of factor VII (FVII) and fibrinogen (Fb) have been reported as risk factors for coronary heart disease in middle-aged and older adults. The purpose of this study was to determine whether increased levels of these and other hemostatic factors (FVIII, von Willebrand factor [vWF]) were associated with other coronary risk factors in young adults participating in the Coronary Artery Risk Development in Young Adults (CARDIA) Study. Hemostatic factors were measured in 1724 participants aged 23 to 35 years who were roughly balanced by sex and race (black/white). Fb was greater in women than men (black, 288 versus 253 mg/dL; white, 267 versus 240 mg/dL; overall P < .05 by Scheffé multiple-comparison test), and FVIII and vWF were higher in blacks than in whites (FVIII in men, 103% versus 88%, and in women, 104% versus 91%; vWF in men, 114% versus 98%, and in women, 117% versus 99%; P < .05). The latter factors were lower in those with blood group O, but within each blood group (except group A), blacks had significantly higher levels of FVIII and vWF. Fb was positively correlated with body mass index (r = .27 to .48, P < .001), total cholesterol (r = .13 to .17, P < .05), and low-density lipoprotein cholesterol (r = .15 to .22, P < .01) in all groups and with blood pressure, triglycerides, and cigarette smoking in white men. FVII correlated positively with cholesterol (r = .12 to .29, P < .05) and triglycerides (r = .23 to .32, P < .001) in all groups and with low-density lipoprotein in whites.(ABSTRACT TRUNCATED AT 250 WORDS)
Social status and coronary artery atherosclerosis in female monkeys.
Authors: Shively C A , Clarkson T B
Published: June 2011

While coronary heart disease is the leading cause of death in women in the United States, research in the area is lacking, especially concerning psychosocial risk factors. The purpose of this experiment was to study the effect of a known psychosocial risk factor in female monkeys, social status, and the effect of alteration of social status on coronary artery atherosclerosis. In previous experiments it has been demonstrated that social status is an enduring characteristic of the individual and that socially subordinate female monkeys have poor ovarian function and exacerbated coronary artery atherosclerosis. In the present experiment, adult female monkeys were fed an atherogenic diet and housed in small social groups, and social status was altered in half of the animals (subordinates became dominant and dominants became subordinate). The manipulation of social status had minimal effects on risk factors but significantly affected coronary artery atherosclerosis, supporting the hypothesis that social status affects atherogenesis in these females. However, all animals that changed social positions had worsened coronary artery atherosclerosis whether they became dominant or became subordinate, and this effect was independent of ovarian function. Subordinates that became dominant had 44% more and dominants that became subordinate had 500% more atherosclerosis than their counterparts that did not change social status. Thus, modification of this psychosocial risk factor was not effective in reducing coronary artery atherosclerosis. The manipulation of social status may have deleteriously altered a complex interaction between individuals and their psychosocial environment.
Increased expression in vivo of VCAM-1 and E-selectin by the aortic endothelium of normolipemic and hyperlipemic diabetic rabbits.
Authors: Richardson M , Hadcock S J , DeReske M , Cybulsky M I
Published: June 2011

Atherosclerosis is enhanced in humans with diabetes mellitus, but the mechanism(s) involved remains unclear. Increased leukocyte-endothelium interaction may be involved, since mononuclear leukocyte adherence to the endothelium is an early event in both experimental atherosclerosis and alloxan-induced diabetes in rabbits. In situ immunohistochemistry was used in en face Häutchen endothelial preparations to identify endothelial cells that stained with antibodies to endothelial leukocyte adhesion molecules (vascular cell adhesion molecule-1 [VCAM-1] and E-selectin), and the number of stained cells per 10,000 cells was determined. Preparations from aortas of diabetic normolipemic and egg yolk diet-induced hyperlipemic diabetic rabbits were compared with those from normoglycemic animals on similar diets. Cross sections of the vessel wall were stained with oil red O and antibodies to VCAM-1, E-selectin, and RAM-11-positive macrophages. After 4 weeks of hyperlipemia the frequency of cells expressing VCAM-1 or E-selectin was significantly increased compared with normolipemic controls; this frequency was further increased in the aortas of hyperlipemic diabetic rabbits. VCAM-1 and E-selectin expression was more frequent in normolipemic diabetic rabbit aortas than in hyperlipemic, normoglycemic vessels. The potentiation of expression of these adhesion molecules in diabetic animals may provide part of the explanation for the enhanced atherosclerosis associated with diabetes mellitus.
Oxidized LDL enhances lipopolysaccharide-induced tissue factor expression in human adherent monocytes.
Authors: Brand K , Banka C L , Mackman N , Terkeltaub R A , Fan S T , Curtiss L K
Published: June 2011

Oxidized low-density lipoprotein (oxLDL) has been characterized as an atherogenic molecule responsible for the induction of a variety of gene products. One such gene, tissue factor (TF), the cellular initiator of the coagulation cascade, is not expressed in normal vascular tissue but is expressed by monocytes and foam cells in atherosclerotic lesions. Therefore, we examined the effect of oxLDL on TF expression in cultured human adherent monocytes. Endotoxin-free oxLDL alone did not induce TF expression in adherent monocytes. However, oxLDL significantly enhanced TF expression induced by the inflammatory mediator, bacterial lipopolysaccharide (LPS), in a time- and dose-dependent manner. In contrast, oxLDL did not alter LPS-mediated production of interleukin-8 and actually inhibited LPS-induced secretion of tumor necrosis factor-alpha, suggesting that some aspects of the signaling pathways for TF induction differ from those of other LPS-responsive monocyte/macrophage gene products. Thus, this study documents specific modulation of the expression of LPS-inducible genes in monocytic cells by oxLDL. Factors that enhance TF expression in monocyte/macrophage cells present in atheroma may contribute to the severity of thrombotic episodes and complications observed in atherosclerosis.
Regulation of tissue factor gene expression in epithelial cells. Induction by serum and phorbol 12-myristate 13-acetate.
Authors: Cui M Z , Parry G C , Edgington T S , Mackman N
Published: June 2011

Cell-specific expression of tissue factor (TF) in vivo is consistent with its primary role in hemostasis. In addition, TF expression is induced in cultured cells by a variety of agents, including serum and growth factors, which define the TF gene as a "primary response" gene. In this study we examined the signaling pathways and cis-acting regulatory elements required for induction of TF gene expression in HeLa cells in response to serum and the tumor promoter, phorbol 12-myristate 13-acetate (PMA). TF activity and mRNA were induced greater than sixfold in quiescent HeLa cells by serum and PMA. TF mRNA induction by both agonists required intracellular Ca2+ mobilization, whereas inhibition of protein kinase C abolished induction of the TF gene by PMA but had no effect on induction by serum. Functional studies demonstrated that a region of the human TF promoter between -96 and +121 bp contained regulatory elements required for serum and PMA induction. These data indicate that different signaling pathways regulate TF gene expression in response to serum and PMA, although the same cis-acting DNA elements may mediate induction.
Determinants of LDL subfraction distribution and concentrations in young normolipidemic subjects.
Authors: Watson T D , Caslake M J , Freeman D J , Griffin B A , Hinnie J , Packard C J , Shepherd J
Published: June 2011

Human low-density lipoproteins (LDLs) comprise a spectrum of particles that vary in size, density, chemical composition, metabolic behavior, and atherogenicity. To identify determinants of this heterogeneity, we measured the percent distribution and plasma concentration of the three major LDL subfractions in 34 young healthy subjects. These parameters were correlated in univariate and multivariate analyses with various body and lifestyle factors; plasma lipids and lipoprotein; and the activities of cholesteryl ester transfer protein, lipoprotein lipase, and hepatic lipase (HL). Women (n = 15) had significantly more large, buoyant LDL (LDL-I; density, 1.025 to 1.034 g/mL) and high-density lipoprotein2 (HDL2) than men (n = 19). Both the percentage and concentration of LDL-I were correlated negatively with very-low-density lipoprotein triglycerides (VLDL-TG) and HL; they were correlated positively with HDL-cholesterol (HDL-C) and HDL2. In addition, percent LDL-I was negatively correlated with plasma triglycerides, VLDL-C, LDL-C, and apo-lipoprotein (apo) B concentrations. The concentrations of intermediate and small, dense LDL (LDL-II and LDL-III; density, 1.034 to 1.044 and 1.044 to 1.060 g/L, respectively) were positively correlated with LDL-C. LDL-III concentrations were also related to plasma cholesterol and apoB concentrations and HL activity. On multivariate analyses, approximately one third of the variability in LDL-I was explained by HL and plasma triglycerides. More than 80% of the variation in LDL-II was accounted for by a model that combined LDL-C and plasma apoB with body mass index and VLDL-TG.(ABSTRACT TRUNCATED AT 250 WORDS)
Enhanced coronary vasoconstrictive response to serotonin subsides after removal of dietary cholesterol in atherosclerotic monkeys.
Authors: Lamping K G , Piegors D J , Benzuly K H , Armstrong M L , Heistad D D
Published: June 2011

Constriction in response to serotonin is enhanced in the coronary arteries of atherosclerotic monkeys. The main objective of the present study was to determine whether abnormal responses to serotonin in atherosclerosis are reversed following removal of dietary cholesterol. In addition, we examined the effect of an atherogenic diet and reduction in dietary cholesterol on vascular responses to activation of ATP-sensitive K+ channels with aprikalim. Diameters of small coronary arteries were measured on the epicardial surface of the left ventricle in vivo by using stroboscopic illumination synchronized to the heart cycle to visually freeze the motion of the heart. Diameters were measured with a microscope-video system during topical application of two vasoconstrictor agonists, serotonin and the thromboxane mimetic U46619, and the vasodilator agonists aprikalim and nitroprusside. Responses were compared in normal (n = 9), atherosclerotic (n = 14; high-cholesterol diet), and regression (n = 8; high-cholesterol diet followed by normal diet) monkeys. Constriction of coronary arteries in response to serotonin was enhanced in monkeys on an atherogenic diet and was normal in regression monkeys. Vasoconstriction in response to U46619 and vasodilation in response to nitroprusside and aprikalim were not altered by atherosclerosis. Thus, abnormal vascular responses to serotonin in small coronary arteries of atherosclerotic monkeys without morphological evidence of disease can be reversed to normal by reducing dietary cholesterol.
Long-term induction and regression of diet-induced atherosclerotic lesions in rhesus monkeys. I. Morphological and chemical evidence for regression of lesions in the aorta and carotid and peripheral arteries.
Authors: Strong J P , Bhattacharyya A K , Eggen D A , Malcom G T , Newman W P , Restrepo C
Published: June 2011

Atherosclerotic lesions were induced in rhesus monkeys by feeding a high-saturated fatty acid and high-cholesterol diet. After 5.4 years the extent of fatty streaks and raised lesions was evaluated in one group of animals (group P) by visual estimation in 10 arterial segments and chemically in four arterial segments. The remaining animals were switched to a basal regression diet low in cholesterol but high in saturated fatty acids for up to 3.7 years. Regression of lesions was evaluated in one group for 1.9 years (group R4) and in another for 3.7 years (group R5) after deleting cholesterol from the diet. The atherogenic diet increased serum cholesterol levels in all animals from a mean of 150 mg/dL to a mean of about 430 mg/dL. The atherogenic diet produced lesions in group P in all arterial segments (involving up to 50% of the arterial intimal surface) and increased cholesterol content in four arterial segments (varying between 443 and 506 micrograms/cm2). Switching to the basal regression diet decreased serum cholesterol levels to normal after 12 to 18 weeks. The switch to the basal diet significantly decreased the extent of fatty streaks in most arterial segments in both groups. Although differences in the mean extent of raised lesions among groups were not statistically significant, 7 of 10 arterial segments in group R4 and 9 of 10 segments in group R5 showed a lesser extent of raised lesions than in group P. Cholesterol content was lower (P < .05) in all four arterial segments in group R5 than in group P.(ABSTRACT TRUNCATED AT 250 WORDS)
Effects of gender and menopausal status on the association of apolipoprotein E phenotype with plasma lipoprotein levels. Results from the Framingham Offspring Study.
Authors: Schaefer E J , Lamon-Fava S , Johnson S , Ordovas J M , Schaefer M M , Castelli W P , Wilson P W
Published: June 2011

Apolipoprotein (apo) E phenotype is an important genetic determinant of plasma low-density lipoprotein (LDL) cholesterol and apo B levels. We have determined apo E phenotype by isoelectric focusing and plasma lipid, lipoprotein cholesterol, apo A-I, apo B, and lipoprotein(a) levels, as well as LDL particle size, in 2258 men and women participating in the Framingham Offspring Study. Apo E phenotype (E2/2, E2/4, E3/2, E3/3, E3/4, and E4/4) was not associated with plasma lipoprotein(a) levels but was associated with plasma LDL cholesterol levels, apo B levels, and LDL size in men and with plasma total cholesterol, LDL cholesterol, and apo B levels in women. The average effect of the epsilon 2 allele was to lower plasma LDL cholesterol levels by 9.2 mg/dL in men and by 13.7 mg/dL in women, while the average effect of the epsilon 4 allele was to increase LDL cholesterol levels by 2.6 mg/dL in men and by 5.4 mg/dL in women. When men were divided into two groups according to their age (< 50 and > or = 50 years old), the average effect of the epsilon 2 allele was to lower plasma levels of LDL cholesterol by 10.2 mg/dL in younger men and by 7.5 mg/dL in older men. In premenopausal women, the average effect of the epsilon 2 allele was to lower LDL cholesterol by 8.2 mg/dL and, in postmenopausal women, by 20.4 mg/dL. An opposite effect of the epsilon 4 allele was observed: the epsilon 4 allele was associated with increases in plasma LDL cholesterol levels of 4.0 mg/dL in younger men and of 1.0 mg/dL in older men.(ABSTRACT TRUNCATED AT 250 WORDS)
Sex-specific effects of the glutamine/histidine polymorphism in apo A-IV on HDL metabolism.
Authors: von Eckardstein A , Funke H , Chirazi A , Chen-Haudenschild C , Schulte H , Schönfeld R , Köhler E , Schwarz S , Steinmetz A , Assmann G
Published: June 2011

In Caucasians, a histidine for glutamine substitution (Gln-->His) at residue 360 in apolipoprotein (apo) A-IV leads to an electrophoretically detectable polymorphism whose contribution to lipid metabolism regulation is controversial. In this study of 426 male and 188 female coronary heart disease patients, we analyzed the impact of this polymorphism on lipid metabolism, particularly high-density lipoprotein (HDL). The frequency of the rarer apo A-IV (360:His) allele was .069. This polymorphism exerted opposite effects in men and women in terms of serum concentrations of total cholesterol; triglycerides; HDL cholesterol; LDL cholesterol; lipoprotein (Lp) A-I; and apo A-I, A-II, and B. Only the difference in Lp A-I levels between male apo A-IV (360:Gln/Gln) homozygotes and apo A-IV (360:Gln/His) heterozygotes was significant (P < .05). In randomly selected subgroups of 38 male and 15 female apo A-IV (360:Gln/His) heterozygotes and 104 male and 15 female apo A-IV (360:Gln) homozygotes, heterozygosity for apo A-IV (360:Gln/His) in both sexes was associated with lower plasma cholesteryl ester transfer protein (CETP) activity (P < .05) and higher serum apo A-IV concentrations (P < .01 in men). Moreover, only men had significantly higher mean plasma activity levels of lecithin:cholesterol acyltransferase (LCAT) (P < .01).(ABSTRACT TRUNCATED AT 250 WORDS)
Identification of matrix metalloproteinases 3 (stromelysin-1) and 9 (gelatinase B) in abdominal aortic aneurysm.
Authors: Newman K M , Ogata Y , Malon A M , Irizarry E , Gandhi R H , Nagase H , Tilson M D
Published: June 2011

A prominent metalloproteinase activity with an apparent molecular mass of 80 kD and additional activities at 67 through 70, 50, and 32 kD have been observed on casein, gelatin, and elastin gel zymography in extracts from abdominal aortic aneurysms (AAAs). The forms at 80, 50, and 32 kD were isolated by affinity to recombinant tissue inhibitor of metalloproteinases, and the 80-kD and 50-kD components were shown to be derived from matrix metalloproteinase-9 (MMP-9). The relative electrophoretic mobility of these forms under reducing and nonreducing conditions corresponds to those of MMP-9 generated by MMP-3 (stromelysin-1) cleavage, and the active forms of MMP-3 at 45 and 35 kD were detected in aneurysmal extracts under reducing conditions by using specific antibody. Confirmation that the major proteolytic activity observed at 80 kD is MMP-9 was also demonstrated by immunoprecipitation of the activity with specific antibody. Comparative immunoblots of tissue extracts from 10 typical AAA patients, using specific antibody against MMP-9, revealed bands at 92, 82, 67, 51 through 53, 27, 23, and 20 kD under reducing conditions; six aortic control specimens displayed negligible immunoreactivity. This report is the first to show that known activated forms of MMP-3 and MMP-9 are present in the aneurysmal aortic wall and that they may play a role in the destruction of aortic matrix in AAA disease.
Evaluation of two insulin assays in insulin resistance syndrome (syndrome X).
Authors: Haffner S M , Mykkänen L , Valdez R A , Stern M P
Published: June 2011

Recent data suggest that proinsulin is associated with cardiovascular risk factors in nondiabetic and diabetic subjects. Since most conventional insulin assays cross-react with proinsulin, it has been suggested that the associations of insulin concentrations with dyslipidemia and hypertension could actually reflect associations with proinsulin. We examined these associations by using both a conventional immunoreactive insulin assay and a specific Linco insulin assay that does not cross-react with proinsulin in 623 nondiabetic and in 180 non-insulin-dependent diabetic subjects who participated in the San Antonio Heart Study, a population-based study of diabetes and cardiovascular disease. Both the immunoreactive insulin assay and the specific Linco insulin assay were equally correlated with cardiovascular risk factors in nondiabetic subjects. Insulin concentrations were moderately correlated with high triglyceride and low high-density lipoprotein cholesterol levels and were weakly correlated with increased blood pressure. In diabetic subjects there were only weak associations between insulin and cardiovascular risk factors using either assay. We conclude that the association of insulin concentrations with cardiovascular risk factors is not a function of using insulin assays that cross-react with proinsulin and that for epidemiological studies of cardiovascular risk factors, conventional immunoreactive insulin assays are as good as the newer specific insulin assays.
Apolipoprotein E Isoform Phenotype and LDL Subclass Response to a Reduced-Fat Diet
Authors: Dreon Darlene M. , Fernstrom Harriett A. , Miller Bonnie , Krauss Ronald M.
Published: June 2011

Abstract
We investigated the association of apolipoprotein (apo) E isoform phenotype with lipoprotein response to reduced dietary fat intake in 103 healthy men (apoE3/2, n=10; apoE3/3, n=65; and apoE4/3, 4/4, n=28). In a randomized, crossover design, subjects consumed high-fat (46%) and low-fat (24%) diets for 6 weeks each. High-fat LDL cholesterol differed among phenotypes, with apoE4/3, 4/4>apoE3/3>apoE3/2. Reduction of LDL cholesterol on the low-fat diet was greater for apoE4/3, 4/4 than apoE3/3 (
P
<.05). There was no significant change in plasma apoB level within any of the apoE phenotype groups on the low-fat diet. This result, together with measurements of LDL subfraction mass by analytical ultracentrifugation, indicated that the primary basis for the diet-induced reduction in LDL cholesterol was not reduced LDL particle number but rather a shift from large, buoyant, cholesterol-rich LDL particles (flotation rate, 7 to 12) to smaller, denser LDL particles (flotation rate, 0 to 7). The magnitude of this effect was related to apoE phenotype, with progressively greater reductions in levels of large LDL (
P
<.01) from apoE3/2 to apoE3/3 to apoE4/3, 4/4. These results indicate that reduced dietary fat lowers levels of large, buoyant LDL particles by an apoE-dependent mechanism.
Association of Hormone Replacement Therapy With Hemostatic and Other Cardiovascular Risk Factors
Authors: Salomaa V. , Rasi V. , Pekkanen J. , Vahtera E. , Jauhiainen M. , Vartiainen E. , Ehnholm C. , Tuomilehto J. , Myllylä G.
Published: June 2011

Abstract
The risk of cardiovascular diseases in women is small until menopause but increases considerably afterwards. When all age groups are considered, cardiovascular diseases are responsible for approximately half of the total mortality in women. It has been suggested that hormone replacement therapy (HRT) in perimenopausal and postmenopausal women could be useful in the prevention of cardiovascular diseases, but its effects are insufficiently known. We performed a cross-sectional study on the associations of menopause and HRT with cardiovascular risk factors, in particular with hemostatic factors, on female participants of the FINRISK Hemostasis Study. The participants, aged 45 to 64 years, were recruited from the Finnish population register by random sampling from three geographically defined areas. The participation rate of women was 83.2%. Of the 1202 women included in the study, 29.2% were current users of HRT. Differences in cardiovascular risk factors by menopausal status and by HRT use were examined after adjustment for age, study area, current smoking, body mass index, self-reported diabetes, and years of education. Postmenopausal women not using exogenous sex hormones had on average a total cholesterol level 0.5 mmol/L (8.9%) higher and an LDL cholesterol level 0.4 mmol/L (11.4%) higher than premenopausal women. Women reporting irregular menstruation (presumably due to perimenopause) had higher adjusted plasma fibrinogen, factor VII coagulant activity, and factor VII antigen than women with regular menstruation or no menstrual periods. HRT users had an adjusted total cholesterol level 0.28 mmol/L (5%) lower (
P
<.0001) and an adjusted LDL cholesterol level 0.3 mmol/L (7%) (
P
<.0001) lower than nonusers. The data also suggested that HRT attenuated the age-dependent difference in total and LDL cholesterol (
P
=.01 for age by HRT interaction). HRT users had lower adjusted insulin and glucose values than nonusers. When the hemostatic factors were studied, the users were seen to have lower adjusted fibrinogen (
P
<.0001) but higher factor VII antigen (
P
=.007) and plasminogen levels (
P
<.0001) than nonusers. No difference was found in factor VII coagulant activity or in Lp(a). In conclusion, HRT users have clearly more favorable lipid profiles as well as insulin and glucose values compared with nonusers. Accordingly, HRT can be a potentially useful adjunct to the prevention of cardiovascular disease. Its effects on hemostatic factors are, however, mixed and of unclear clinical significance at the moment. More prospective studies on the effects of HRT on hemostasis are therefore needed before it can be recommended for the prevention of cardiovascular diseases.
T Helper Cell Infiltration and Foam Cell Proliferation Are Early Events in the Development of Atherosclerosis in Cholesterol-Fed Rabbits
Authors: Drew A.F. , Tipping P.G.
Published: June 2011

Abstract
The involvement of T cells in the early cellular events in atherosclerosis was studied in rabbits fed a 1% cholesterol diet by use of specific monoclonal anti-rabbit CD5 and CD4 antibodies. T cells were not seen in the aortic intimas of rabbits not fed cholesterol but were seen in intimal lesions in cholesterol-fed rabbits. Accumulation of T cells in plaques occurred between 2 and 4 weeks after commencement of cholesterol feeding, and the greatest density of CD5-positive T cells was observed after 4 weeks (11.2±6.0 cells/mm
2
[mean±SEM];
P
<.02 compared with normal control rabbits,
P
<.03 compared with 2-week plaques). Staining for CD4 indicated that the majority of these T cells were T helper cells (9.9±4.9 cells/mm
2
). At this time, plaques showed a dense cellular infiltrate of macrophages (3623±467 cells/mm
2
) and macrophage proliferation was evident (2.1±1.1% of total plaque cells). As the cross-sectional area of intimal lesions increased progressively in subsequent weeks, their cellularity declined (8 weeks, 2239±271 cells/mm
2
; 12 weeks, 1535±55 cells/mm
2
; 16 weeks, 1747±242 cells/mm
2
,
P
<.05 for all groups compared with the 4-week group). The density of the T cell infiltrate (8 weeks, 6.7±3.0 cells/mm
2
; 12 weeks, 0.6±0.2 cells/mm
2
; 16 weeks, 1.0±0.4 cells/mm
2
) and the proliferative index of cells within plaques (8 weeks, 0.6±0.2%; 12 weeks, 0.8±0.3%; 16 weeks, 0.2±0.2%) also declined. Smooth muscle cell capping was observed in these later plaques without smooth muscle cell proliferation. These studies demonstrate that helper T cell infiltration into plaques is an early event in atherogenesis and is associated with local macrophage proliferation, suggesting a role for T cells in the initiation of atherosclerosis.
Effect of the Antioxidant
N,N′
-Diphenyl 1,4-Phenylenediamine (DPPD) on Atherosclerosis in ApoE-Deficient Mice
Authors: Tangirala Rajendra K. , Casanada Florencia , Miller Elizabeth , Witztum Joseph L. , Steinberg Daniel , Palinski Wulf
Published: June 2011

Abstract
Apolipoprotein (apo) E–deficient mice develop atherosclerotic lesions that contain epitopes formed during the oxidative modification of lipoproteins, and they demonstrate high titers of circulating autoantibodies against such epitopes, suggesting that this murine strain may provide a model to investigate the atherogenic mechanisms of oxidized lipoproteins (Palinski et al,
Arterioscler Thromb
. 1994;14:605-616). To test the hypothesis that lipoprotein oxidation contributes to lesion formation in apoE-deficient mice, we studied the effect of the antioxidant
N,N′
-diphenyl 1,4-phenylenediamine (DPPD) in mice fed a high-fat diet containing 0.15% cholesterol. Animals were divided into two subgroups matched for sex and plasma cholesterol levels, and DPPD (0.5% wt/wt) was added to the diet of one subgroup. Throughout the 6 months of intervention, DPPD treatment had no significant effect on plasma cholesterol. Plasma levels of DPPD at the end of the experiment were 33.1 μmol/L. As judged by resistance to loss of polyunsaturated fatty acids, lipoproteins (
d
<1.019 g/mL) from DPPD-treated animals showed greater resistance to copper-induced oxidation than lipoproteins from control animals. In addition, there was a greater than twofold prolongation of the lag time in the formation of conjugated dienes in the LDL and IDL fractions of DPPD-treated mice. Atherosclerosis was significantly reduced, by 36% in the DPPD-treated mice (14.0±4.53% of aortic surface area versus 21.9±11.6%; n=32;
P
<.02). These results are consistent with the hypothesis that lipoprotein oxidation contributes to atherogenesis in apoE-deficient mice. However, further studies with other antioxidants are needed to validate this hypothesis.
Differences in the Phenotypic Characteristics of Subjects With Familial Defective Apolipoprotein B-100 and Familial Hypercholesterolemia
Authors: Miserez André R. , Keller Ulrich
Published: June 2011

AbstractFamilial defective apolipoprotein B-100 (FDB) is a recently identified autosomal-dominantly inherited disorder caused by a point mutation in the apolipoprotein (apo) B gene. To determine whether the phenotypic characteristics in FDB subjects are similar to those in subjects with familial hypercholesterolemia (FH), 76 kindreds fulfilling the clinical criteria for heterozygous FH/FDB were characterized using molecular biological techniques. Allele-specific polymerase chain reaction (PCR) at the apoB locus was used for diagnosis or exclusion of FDB. PCR-based methods for detection of two point mutations (V408M and P664L) at the LDL receptor (LDLR) locus, cosegregation analysis using eight restriction fragment length polymorphisms (RFLPs) at the LDLR locus, or the exclusion of FDB confirmed the clinical diagnosis of FH. Three kindreds were not included because of a missing cosegregation between a particular haplotype and the FH phenotype. We predicted that a similar number of kindreds would be detected in the two groups, assuming comparable prevalences of the diseases in our population and similar phenotypic characteristics. However, only nine kindreds were identified with the FDB mutation compared with 64 kindreds with FH (P<.0001). From these 73 kindreds, 28 FDB heterozygotes and 129 FH heterozygotes were compared using multivariate analysis. There were no differences between these two groups with respect to age, sex, and apoE genotype distribution, lipoprotein(a) concentrations, body mass index, blood pressure, and smoking habits. However, FDB subjects demonstrated significantly lower concentrations of total cholesterol (8.1 versus 10.2 mmol/L,P<.001), LDL cholesterol (6.3 versus 8.2 mmol/L,P<.001), and triglycerides (1.3 versus 1.8 mmol/L,P=.025) and higher concentrations of HDL cholesterol (1.4 versus 1.2 mmol/L,P=.015) than subjects with FH. In contrast to FH, female FDB subjects tended to have higher concentrations of total cholesterol (8.9 versus 7.5 mmol/L,P=.032) and LDL cholesterol (7.1 versus 5.7 mmol/L,P=.026) than FDB males. The same results regarding total and LDL cholesterol and sex differences were observed when individual data of 238 FDB and 415 FH subjects from the literature were compared. In addition, FDB subjects showed much larger total cholesterol fluctuations than FH subjects (median of intraindividual coefficients of variation: FDB, 14.5%; FH, 5.3%;P<.001). In summary, these results demonstrate that FDB subjects tend to have a milder form of hyperlipoproteinemia than FH subjects and that only a part of the subjects with FDB fulfill the established criteria for identifying FH.
A Major Locus Influencing Plasma High-Density Lipoprotein Cholesterol Levels in the San Antonio Family Heart Study
Authors: Mahaney Michael C. , Blangero John , Rainwater David L. , Comuzzie Anthony G. , VandeBerg John L. , Stern Michael P. , MacCluer Jean W. , Hixson James E.
Published: June 2011

AbstractTo detect and measure the effects of a single locus on quantitative variation in plasma concentrations of HDL cholesterol (HDL-C), we conducted statistical genetic analyses on data from 526 Mexican American individuals in 25 randomly ascertained pedigrees. By using maximum-likelihood complex segregation analysis, we found evidence for a major locus with a codominant mixture model that included the phenotypic means, standard deviations, relative frequency of a low HDL-C allele, and heritability for plasma HDL-C levels, plus the effects of sex (genotype specific), age-by-sex, age2-by-sex, plasma concentrations of apolipoprotein (apo)AI and triglycerides (genotype specific), exogenous sex hormone use, and menopausal status under an unrestricted general model. Inclusion of the four covariates (in addition to the sex and age-by-sex effects) accounted for nearly 79% of the variance in total plasma HDL-C levels. Of the remaining 21% of the variance, the detected major locus accounted for approximately 55% in men and 21% in women; the total genetic contributions to the variance by genes were approximately 82% in men and 69% in women. Linkage analyses with penetrance parameter estimates from the segregation analysis excluded tight linkage between the detected major locus and markers for the following candidate loci: the apoAI/apoCIII genomic region (P<.05), apoB (P<.01), hepatic lipase (P<.001), lipoprotein lipase (P<.001), and the LDL receptor (P<.001). While not excluding the apoE locus (LOD=−0.348,P<.21), the analysis provided no support for tight linkage between it and the detected major locus.
Balloon Catheterization Induces Arterial Expression of Embryonic Fibronectins
Authors: Dubin Daniel , Peters John H. , Brown Lawrence F. , Logan Barry , Kent K. Craig , Berse Brygida , Berven Sigurd , Cercek Bojan , Sharifi Behrooz G. , Pratt Richard E. , Dzau Victor J. , Van De Water Livingston
Published: June 2011

AbstractFibronectins (FNs) comprise a family of adhesive extracellular matrix proteins that arise by alternative splicing in three regions: V (IIICS), EIIIA (ED-A), and EIIIB (ED-B). FNs bearing the EIIIA and EIIIB segments are prevalent during embryogenesis, expressed to lesser degrees in normal adult tissues, and may be locally reexpressed at sites of adult tissue injury. RNase mapping shows that normal rat arteries express low levels of FNs that are predominantly EIIIA−and EIIIB−. Following balloon injury, arterial walls produce increased total levels of FN transcripts that preferentially include both the EIIIA and EIIIB segments. However, despite inducing increased total FN mRNA, balloon injury does not alter the relative composition of V120+, V95+, and V0 spliced forms. In situ hybridization reveals that as early as 4 days after injury medial cells express increased total FN mRNA, and by 7 days substantial neointimal and focal medial synthesis of EIIIA+, EIIIB+, and V120+FNs occurs; macrophages do not significantly contribute to this observed vascular FN synthesis. Consistent with the mRNA data, immunofluorescence microscopic analysis reveals increased deposition of EIIIB+and V+FN protein forms in injured arterial walls, particularly within the neointima. Our results suggest that local synthesis of specific FN isoforms is important to the neointimal formation that ensues after balloon injury.
Stimulation of Gsand Inhibition of GiProtein Functions by Minimally Oxidized LDL
Authors: Parhami Farhad , Fang Zhuang T. , Yang Brian , Fogelman Alan M. , Berliner Judith A.
Published: June 2011

AbstractWe have previously shown that treatment of aortic endothelial cells with minimally oxidized LDL (MM-LDL) induces their interaction with monocytes but not neutrophils and that these induced responses are associated with increased cAMP levels. Here we studied the mechanism by which MM-LDL elevates cAMP levels. Treatment of human aortic endothelial cells with MM-LDL resulted in a saturable dose-dependent increase in cAMP levels. Studies using a combination of pertussis toxin and MM-LDL suggested that part of the cAMP increase was due to the stimulation of Gscomplexes. Studies with pertussis toxin–treated membranes in which Giwas completely inhibited were used to directly address the effect of MM-LDL on the Gspathway. MM-LDL and an oxidized lipid (palmitoyl arachidonyl phosphatidylcholine), the effects of which mimic those of MM-LDL, caused a 40% to 100% increase in cAMP levels in these isolated membranes that was augmented by GTP, thus showing Gsstimulation. These results also show that MM-LDL increases cAMP levels by inhibiting Gi. MM-LDL inhibited ADP ribosylation of Giby about 30% and completely abolished the ability of serotonin to interact with Gicomplexes, whereas direct activation of Giby mastoparan was not inhibited. This observation suggests that MM-LDL interferes with the interaction of Gimolecules with inhibitory receptors. There was no direct effect of MM-LDL on adenylate cyclase. Overall, these studies show that MM-LDL increases cAMP levels both by stimulating Gsand inhibiting Gicomplexes.
Human Endothelial Cell Damage by Neutrophil-Derived Cathepsin G
Authors: Iacoviello Licia , Kolpakov Valeri , Salvatore Lorena , Amore Concetta , Pintucci Giuseppe , de Gaetano Giovanni , Donati Maria Benedetta
Published: June 2011

Abstract
Cathepsin G, a major protease released by activated neutrophils, induces functional and morphological damage to human endothelial cells. We studied the mechanisms involved and ways to reverse this damage. Cathepsin G induced a concentration- and time-dependent injury to human umbilical vein endothelial cell (HUVEC) morphology simultaneous with cytoskeleton rearrangement. Preincubation of the endothelial monolayer with phallacidin completely prevented damage to cell morphology by cathepsin G, whereas preincubation with cytochalasin B potentiated its activity. Damage to cell shape and F-actin cytoskeleton were prevented by eglin C, an inhibitor of the active site of cathepsin G. Furthermore, cathepsin G increased transcellular permeability to albumin and induced a time-dependent detachment of PAI-1 from the extracellular matrix of a cell-free system. The inhibition of matrix-bound PAI-1 activity by specific antibodies induced changes in HUVEC monolayers similar to those observed after cathepsin G. However, although stabilization of F-actin microfilaments by phallacidin prevented changes in cell shape, it did not prevent the ability of cathepsin G to increase cell permeability and release matrix PAI-1. The damage of cathepsin G to cell morphology and cytoskeleton arrangement was reversed within 12 hours if the deendothelialization area was <50% to 55% and the subendothelial matrix was still able to bind the newly synthesized PAI-1. Thrombin, whose role in the thrombotic process is well known, also induced changes in cell morphology and cytoskeleton arrangement of HUVEC. Cathepsin G reaches the subendothelial matrix through an increase in cell permeability and injures endothelial cell morphology by detaching matrix-bound PAI-1. These events expose a highly thrombogenic surface to which platelets can adhere, become activated, attract further neutrophils, and trigger thrombus formation.
Role of Nitric Oxide in Hemostatic System Activation In Vivo in Humans
Authors: Krejcy Kurt , Schmetterer Leopold , Kastner Johannes , Nieszpaur-Los Malgorzata , Monitzer Brigitte , Schütz Wolfgang , Eichler Hans-Georg , Kyrle Paul A.
Published: June 2011

Abstract
NO is a potent inhibitor of in vitro platelet aggregation and adhesion. In view of possible future widespread use of NO in pulmonary and cardiovascular diseases, we investigated the role of NO in hemostatic system activation in vivo in humans. Sixteen healthy male volunteers (age range, 22 to 33 years) received either NO by inhalation (50 ppm over 30 minutes; n=8) or the NO synthase inhibitor
N
G
-monomethyl
l
-arginine (
l
-NMMA 3 mg/kg body weight IV over 5 minutes; n=8). β-Thromboglobulin (β-TG), an indicator of platelet activity; prothrombin fragment 1+2 (F
1+2
), an index of coagulation activation; and thromboxane B
2
(TxB
2
), a measure of platelet prostaglandin synthesis, were determined in blood samples obtained from bleeding-time incisions (“shed blood”) at baseline and after administration of the respective drug. In addition, β-TG and F
1+2
were also determined in venous blood. To verify the systemic effects of the drugs, methemoglobin and plasma nitrites/nitrates were measured in the NO group, and cardiac output and exhaled NO were measured in the
l
-NMMA group. Compared with baseline, methemoglobin and plasma nitrates increased by 73±12% (
P
=.006) and 60±9% (
P
<.001), respectively, following NO inhalation.
l
-NMMA infusion resulted in decreases in both cardiac output (by 16±2%;
P
<.001) and exhaled NO (by 54±7%;
P
<.001). NO inhalation or
l
-NMMA infusion had no significant effect on β-TG, F
1+2
, and TxB
2
levels in shed blood. No significant changes in platelet counts and levels of coagulation activation markers were found in venous blood after drug administration. In contrast to the in vitro data, neither inhalation of NO nor inhibition of NO synthesis by infusion of
l
-NMMA had a major impact on hemostatic system activation in vivo in healthy individuals.