bluuebunny/crossref_metadata_2025 huggingface dataset:
A case-control study of lipoprotein particles in two populations at contrasting risk for coronary heart disease. The ECTIM Study.
Authors: Parra H J , Arveiler D , Evans A E , Cambou J P , Amouyel P , Bingham A , McMaster D , Schaffer P , Douste-Blazy P , Luc G
Published: June 2011

The incidence of coronary heart disease (CHD) in middle-aged men is more than three times higher in Northern Ireland than in France. The ECTIM study, which is based on WHO MONICA centers in Belfast (Northern Ireland), Strasbourg (eastern France), Toulouse (southwestern France), and Lille (northern France), has been established to investigate this striking difference. Male patients aged 25-64 years with myocardial infarction (MI) and control subjects sampled from the general population were recruited in the four centers. Hypolipidemic drug treatment was much more frequent in France than in Belfast. "Hypercholesterolemia" defined by the presence of hypolipidemic drug treatment or a low density liproprotein cholesterol level greater than 200 mg/dl was more frequent in cases than in controls in both countries but was similar in both control groups. An in-depth study of lipid variables, including measurements of cholesterol fractions, triglycerides, apolipoproteins (apo), and lipoprotein particles (Lp), was performed in nonhypercholesterolemic subjects. In Northern Ireland and France, patients in comparison with controls had lower levels of high density lipoprotein cholesterol, apo A-I, apo A-II, Lp A-I, and Lp A-II:A-I and higher levels of Lp E:B and Lp(a):B. The levels of triglycerides, very low density lipoprotein cholesterol, apo B, and Lp C-III:B were higher in cases than in controls only in Belfast. In control subjects, the mean levels of cholesterol fractions and apolipoproteins were similar in Northern Ireland and France; however, the level of Lp A-I was lower and the levels of Lp E:B and Lp(a):B were higher in Northern Ireland than in France.(ABSTRACT TRUNCATED AT 250 WORDS)
Induction of arteriosclerosis in normocholesterolemic rabbits by immunization with heat shock protein 65.
Authors: Xu Q , Dietrich H , Steiner H J , Gown A M , Schoel B , Mikuz G , Kaufmann S H , Wick G
Published: June 2011

Previous studies have established the presence of high numbers of activated T lymphocytes and "aberrant" expression of major histocompatibility complex class II antigens by endothelial and smooth muscle cells in human atherosclerotic lesions, implicating the involvement of a local cellular immune response. The identity of the antigen(s) eliciting this immune response, the extent of their effect, and the atherogenic stage at which they occur remain to be determined. In the present studies, 120 normocholesterolemic New Zealand White rabbits were immunized one or more times with various antigens, with or without adjuvants. The antigens and adjuvants included human or rabbit atherosclerotic lesion proteins, ovalbumin, Freund's complete and/or incomplete adjuvants, recombinant mycobacterial heat shock protein 65 (hsp65), and two hsp-free adjuvants, Ribi complete adjuvant and lipopeptide. In addition, some groups received a high-cholesterol diet. Sixteen weeks after the first immunization the animals were killed, and arteriosclerotic lesions in the intima of the aortic arch were found to have developed only in those animals immunized with antigenic preparations containing hsp, either in the form of whole mycobacteria or as purified recombinant hsp65, although their serum cholesterol levels were normal. No arteriosclerotic changes exceeding those of controls were found in the other groups, irrespective of the antigen used. Immunohistopathologic examination revealed that the lesions contained 20% T cells, 10-30% macrophages, and 10-40% smooth muscle cells. Analysis of the peripheral blood T-lymphocyte proliferative responses revealed that the occurrence of lesions was positively correlated with the presence of hsp65-reactive T cells, suggesting that hsp65 is involved in the induction of arteriosclerotic lesions. Furthermore, combined immunization with hsp-containing material and a cholesterol-rich diet provoked development of significantly more severe atherosclerosis and the appearance of characteristic foam cells. We conclude that an (auto)immune response to hsp may initiate the development of atherosclerosis and that a high blood cholesterol level is only one albeit a very important risk factor.
Lathosterol and other noncholesterol sterols during treatment of hypercholesterolemia with lovastatin alone and with cholestyramine or guar gum.
Authors: Uusitupa M I , Miettinen T A , Happonen P , Ebeling T , Turtola H , Voutilainen E , Pyörälä K
Published: June 2011

Sixty-two patients aged 19-64 years with primary hypercholesterolemia (mean level of total cholesterol, 10.8 mmol/l) were treated with 80 mg/day lovastatin (L) alone for 18 weeks and, after randomization to either L + 20 g/day guar gum (L + GG) or L + 16 g/day cholestyramine (L + C) treatments, for an additional 18 weeks. The total cholesterol level declined from baseline by 34% during L and by 44% and 48% during L + GG and L + C, respectively. In terms of micromoles per millimole of cholesterol, serum levels of the cholesterol synthesis precursors cholestenol, desmosterol, and lathosterol were decreased and those of the plant sterols campesterol and sitosterol were increased by treatment with L. The serum contents of cholesterol precursors were increased markedly after the combination of either GG or C with L, but the increase was greater after the addition of C (e.g., the lathosterol to cholesterol ratio was 51% versus 212% for L + GG and L + C, respectively; p less than 0.001). Thus, a higher rate of removal of bile acids by C than by GG reduced more effectively the low density lipoprotein cholesterol level but simultaneously stimulated cholesterol synthesis compensatorily to a higher level even under concurrent treatment with L. The serum sitosterol to cholesterol ratio declined by 13% during L + GG but increased by 49% during L + C compared with the value under L alone, suggesting different effects of GG and C on the metabolism of plant sterols.
Reduced HDL2 cholesterol subspecies and elevated postheparin hepatic lipase activity in older men with abdominal obesity and asymptomatic myocardial ischemia.
Authors: Katzel L I , Coon P J , Busby M J , Gottlieb S O , Krauss R M , Goldberg A P
Published: June 2011

Silent myocardial ischemia (SI), an asymptomatic manifestation of coronary artery disease (CAD), was identified in 10% of apparently healthy nonsmoking, nondiabetic older (60 +/- 7 years, mean +/- SD) men with normal plasma cholesterol levels. We hypothesized that in the absence of other major risk factors for CAD, the men with SI would have reduced plasma levels of high density lipoprotein (HDL) and HDL2 subspecies due to an upper-body fat distribution (waist-to-hip ratio [WHR]), hyperinsulinemia, and abnormal postheparin plasma lipoprotein lipase (LPL) and hepatic lipase (HL) activities. Compared with 47 normal control subjects of similar age, obesity, and maximal aerobic capacity, the 18 men with SI had higher plasma triglyceride (TG) (162 +/- 71 versus 102 +/- 39 mg/dl, p less than 0.001) and lower HDL-C (33 +/- 6 versus 37 +/- 7 mg/dl, p less than 0.02) levels with no difference in low density lipoprotein cholesterol level. The HDL2b and HDL2a subspecies measured by gradient gel electrophoresis were also lower in the men with SI (p less than 0.01). The plasma glucose and insulin responses during an oral glucose tolerance test were the same in both groups. Postheparin plasma HL activity was significantly higher in 12 men with SI than in 41 control subjects (34 +/- 8 versus 27 +/- 10 mumol/ml.hr-1, p less than 0.03) and was correlated with log insulin area (r = 0.36, p less than 0.05) and WHR (r = 0.32, p less than 0.05) in the control subjects but not in the men with SI. In the control group, the percent HDL2b subspecies was correlated inversely with postheparin plasma HL activity (r = -0.46, p less than 0.01, n = 41) as well as WHR (r = -0.49, p less than 0.001, n = 47) and log insulin area (r = -0.37, p less than 0.05, n = 47) but not in the men with SI. Postheparin LPL activity was the same in both groups of men and did not correlate with HDL, WHR, insulin, or plasma TG levels. As the control subjects and men with SI had comparable degrees of abdominal obesity and hyperinsulinemia, these results suggest that the reduced HDL-C levels in men with SI may be related to elevations in HL activity. Thus, abdominal obesity, hyperinsulinemia, elevated TG levels, and low HDL-C and HDL2 subspecies levels may predispose these older men to atherosclerosis.
Effect of dietary olive and sunflower oils on the lipid composition of the aorta and platelets and on blood eicosanoids in rats.
Authors: Navarro M D , Hortelano P , Periago J L , Pita M L
Published: June 2011

The effects on aortic and platelet fatty acid compositions and on blood levels of prostacyclin and thromboxane A2 of low- and high-fat diets containing olive oil or sunflower oil were studied. For 4 weeks, four groups of weanling rats were fed a basal diet containing 5% or 25% olive oil or sunflower oil. Rats fed olive oil diets showed higher levels of 18:1(n-9) and polyunsaturated fatty acids of the n-3 series and lower percentages of 18:0 and 18:2(n-6) in aortic and platelet phosphatidylcholine and phosphatidylethanolamine than those fed the sunflower oil diets. Arachidonic acid increased in platelet phosphatidylethanolamine and aortic phosphatidylcholine of rats fed the diet containing 5% sunflower oil compared with those fed 5% olive oil. Plasma 6-ketoprostaglandin F1 alpha increased in both groups of animals fed olive oil while these rats also showed the lowest levels of serum thromboxane B2 and plasma cholesterol. Olive oil feeding leads to changes in lipid metabolism of the vascular compartment that could be favorable in the prevention of thrombosis and atherosclerosis.
Turnover of synthetic class A amphipathic peptide analogues of exchangeable apolipoproteins in rats. Correlation with physical properties.
Authors: Garber D W , Venkatachalapathi Y V , Gupta K B , Ibdah J , Phillips M C , Hazelrig J B , Segrest J P , Anantharamaiah G M
Published: June 2011

Peptide analogues of the class A amphipathic helixes from exchangeable apolipoproteins mimic apolipoprotein (apo) A-I in a number of ways, including the ability to activate the enzyme lecithin:cholesterol acyltransferase, to associate with high density lipoproteins (HDLs), and to form HDL-like particles in the presence of lipids. This study investigated the metabolic properties of several of these peptide analogues in the rat. Peptide analogues studied were 18A (referred to as L-18A to differentiate it from D-18A, and which mimics apolipoprotein amphipathic helical domains in its charge distribution), 37pA (a dimer of two 18A monomers separated by a proline), 18R (with reversed charge distribution compared with 18A), and D-18A (identical in amino acid sequence to 18A but synthesized from D-amino acids). Peptides were radiolabeled with 125I. In addition, metabolism of rat and human 125I-apo A-I and human 14C-apo A-I was studied; no significant differences in clearance of these preparations were seen. Clearance data were fitted to multiexponential equations to give half-times of clearance; biexponential equations consistently provided the best nonlinear least-squares curve fit. The order of relative lipid affinity determined in vitro was 37pA greater than apo A-I greater than D-18A = L-18A greater than 18R. Half-times of clearance were in the same approximate rank order: 37pA, 6.9 +/- 3.3 hours (mean +/- SD); apo A-I, 6.9 +/- 1.8 hours; D-18A, 4.0 +/- 1.0 hours; L-18A, 4.6 +/- 1.6 hours; and 18R, 0.9 +/- 0.1 hour.(ABSTRACT TRUNCATED AT 250 WORDS)
Oxidatively modified HDLs are potent inhibitors of cholesterol biosynthesis in human skin fibroblasts.
Authors: Ghiselli G , Giorgini L , Gelati M , Musanti R
Published: June 2011

Several biological properties of lipoproteins are modified by oxidative reactions. Modified lipoproteins are rapidly degraded by macrophages, and this is likely to be a major pathway for the formation of foam cells in the early phases of atherosclerosis. The effect of modification on other aspects of cholesterol homeostasis has, however, received lesser attention. In this study, the influence of copper ion- as well as rat aortic smooth muscle cell-oxidation-modified high density lipoprotein (HDL) on cholesterol biosynthesis in human skin fibroblasts has been investigated. Modified lipoproteins eluted at higher ionic strength than did control HDL on a Mono-Q 5/5 anion-exchange column. However, only copper ion-modified HDLs displayed greater electrophoretic mobility than did control lipoproteins on agarose gel electrophoresis. Both control and modified HDLs decreased cholesterol esterification in fibroblasts. On the other hand, whereas control HDLs were virtually ineffective in modulating cholesterol biosynthesis, modified HDLs had a significant suppressing effect. This was observed in normal as well as low density lipoprotein (LDL) receptor-defective fibroblasts, which are unresponsive to the LDL-mediated downregulation of cholesterol synthesis. These results are consistent with the concept that oxidative modification of HDLs drastically alters their effect on cholesterol homeostasis in fibroblasts. The data furthermore suggest the existence of a lipoprotein pathway for cholesterol biosynthesis regulation that is independent of the LDL receptor-mediated pathway. Downregulation of cholesterol biosynthesis would be a new function for oxidatively modified lipoproteins.
Influence of gender, body mass index, and age on response of plasma lipids to dietary fat plus cholesterol.
Authors: Clifton P M , Nestel P J
Published: June 2011

We have conducted a crossover, randomized, double-blind dietary trial that tested the hypothesis that gender influences the response of plasma lipids, in particular high density lipoprotein (HDL) cholesterol, to dietary fat plus cholesterol. Twenty-six men and 25 women were matched for age, low density lipoprotein (LDL) cholesterol, triglyceride, and body mass index (BMI). After a 2-week baseline low-fat (27% of calories), low-cholesterol period, subjects were given two isocaloric liquid supplements for 3 weeks each, one containing 31 g fat (56% saturated) and 650 mg cholesterol, and the other fat free. The baseline HDL2 cholesterol level was significantly higher in women: 0.41 versus 0.26 mmol/l (p less than 0.01). Importantly, women also showed a greater rise in HDL2 cholesterol concentration with the fat/cholesterol supplement: 0.09 versus 0.03 mmol/l (p less than 0.01). The greater increment in women was related to their higher baseline HDL2 cholesterol levels. With the fat and cholesterol supplement, LDL cholesterol values rose from 3.76 to 4.04 mmol/l in women and from 3.77 to 4.13 mmol/l in men. The baseline LDL cholesterol value was found to account for about 35% of the variance in the rise in LDL cholesterol level with fat and cholesterol supplementation in both men and women less than 50 years. In men only, there was a significant effect of age: the change in LDL cholesterol with the fat/cholesterol supplement was 0.16 mmol/l in those less than 50 and 0.54 mmol/l in those greater than 50 years old (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
Continuous infusion of interleukin-1 beta in rats induces a profound fall in plasma levels of cholesterol and triglycerides.
Authors: Hermus A R , Sweep C G , Demacker P N , van der Meer M J , Kloppenborg P W , van der Meer J W
Published: June 2011

During infectious diseases, striking alterations in plasma concentrations of cholesterol (hypocholesterolemia) and triglycerides (hypertriglyceridemia) may occur. It has been suggested that interleukin-1 is a mediator of these alterations. We studied the effects of continuous administration of recombinant human interleukin-1 beta (rhIL-1 beta) on plasma levels of cholesterol and triglycerides. A total of 42 rats were equipped with minipumps loaded with either rhIL-1 beta (delivery rate of 0.5, 2.0, or 4.0 micrograms/day i.p. for 1 week) or saline. After 1 day of treatment with rhIL-1 beta, plasma cholesterol levels had not changed. On day 2 a remarkable decrease of plasma cholesterol levels was observed in rats treated with 2.0 micrograms rhIL-1 beta/day (1.49 +/- 0.13 versus 2.23 +/- 0.08 mmol/l, p less than 0.005; rhIL-1 beta versus saline) or 4.0 micrograms rhIL-1 beta/day (1.46 +/- 0.04 versus 2.18 +/- 0.04 mmol/l,p less than 0.0005). This decrease persisted until the end of the experiment and occurred in all major lipoprotein fractions. Triglycerides in plasma (and in very low density lipoprotein) decreased almost concomitantly with plasma cholesterol, although to a lesser degree. Infusion of 2.0 micrograms rhIL-1 beta/day did not affect either cholesterol esterification or total postheparin lipolytic activity in plasma. Long-term infusion with 4.0 micrograms rhIL-1 beta/day induced prolonged fever, whereas at the lower doses temperatures were elevated only the first 2 days. rhIL-1 beta at a dose of 2.0 and 4.0 micrograms/day induced a transient decrease of food intake and a suppression of body weight gain.(ABSTRACT TRUNCATED AT 250 WORDS)
Siblings with normal LDL receptor activity and severe hypercholesterolemia.
Authors: Harada-Shiba M , Tajima S , Yokoyama S , Miyake Y , Kojima S , Tsushima M , Kawakami M , Yamamoto A
Published: June 2011

We report about a brother and sister having clinical symptoms similar to those of homozygous familial hypercholesterolemia (FH) but surprisingly who have normal low density lipoprotein (LDL) receptor activities (M. Harada-Shiba et al, J Jpn Atheroscler Soc 1991; 19:227-242). The LDL receptor activities in the cultured fibroblasts of the patients were compared with those of FH heterozygotes and homozygotes for the LDL receptor mutation. The LDL receptor activities in the cultured fibroblasts of the patients were in the normal range, but their plasma cholesterol concentrations were similar to patients with homozygous FH. After the plasma LDL was removed by plasmapheresis in both patients, plasma cholesterol levels started to increase. The "rebound" of plasma cholesterol was compared with those for heterozygous and homozygous FH. The plasma cholesterol levels of the patients, which were greater than 410 mg/dl 2 weeks after plasmapheresis, were much higher than those of FH heterozygotes (232-311 mg/dl) but similar to those of FH homozygotes (345-464 mg/dl). The urinary mevalonate excretion rate, which reflects the rate of whole-body cholesterol synthesis, was higher for the brother (patient 1, 32.6 nmol/kg.day-1) than for the normal subjects (17.7 +/- 4.1 nmol/kg.day-1) but was similar to those of FH homozygotes (31.2 +/- 4.3 nmol/kg.day-1) and heterozygotes (29.8 +/- 10.9 nmol/kg.day-1). To estimate the catabolic and production rates of cholesterol in the brother, the time course for the increment in the total cholesterol level after plasmapheresis was analyzed by the two-compartment model.(ABSTRACT TRUNCATED AT 250 WORDS)
Osteopontin overexpression is associated with arterial smooth muscle cell proliferation in vitro.
Authors: Gadeau A P , Campan M , Millet D , Candresse T , Desgranges C
Published: June 2011

To isolate the genes involved in the cell cycle G1 phase progression of arterial smooth muscle cells (SMCs), a cDNA clone (M11) was previously selected by differential hybridization screening of a mid-G1 serum-stimulated SMC cDNA library. The delay of induction after mitogenic stimulation, time of expression, and need for new protein synthesis for full expression made it possible to classify this gene in the "delayed early" gene group. Determination of the partial M11 cDNA sequence showed full homology with the osteopontin gene (secreted phosphoprotein 1, 2ar), an Arg-Gly-Asp-containing extracellular matrix protein. Osteopontin mRNA was also detected in the aorta at levels as high as in the kidney but lower than in bone, two tissues in which it has been previously detected. In vitro analysis of osteopontin expression in serum-stimulated quiescent SMCs and asynchronously cycling SMCs demonstrated that osteopontin overexpression was associated with SMC proliferation. In view of our results, the high osteopontin expression observed by others in the injured carotid artery could be explained by the involvement of SMCs in the proliferative process. Taken together, these results suggest that osteopontin may play an important role in pathological processes that are associated with arterial SMC proliferation, such as atherosclerosis or restenosis.
Characterization of apoA-IV-containing lipoprotein particles isolated from human plasma and interstitial fluid.
Authors: Duverger N , Ghalim N , Ailhaud G , Steinmetz A , Fruchart J C , Castro G
Published: June 2011

Apolipoprotein (apo) A-IV has been proposed to play a role in reverse cholesterol transport. ApoA-IV-containing lipoprotein particles (A-IVLp) were isolated from human plasma and interstitial fluid and characterized by immunoaffinity chromatography. Two major A-IVLp subpopulations, lipoprotein particles containing apoA-IV with apoA-I (LpA-I:A-IV) and lipoprotein particles containing apoA-IV without apoA-I (LpA-IV), were identified. The larger subpopulation of A-IVLp is the LpA-IV that represents 70% (protein mass) of the initial particles. Only 5.8% of apoA-IV was recovered in the retained fraction after affinity chromatography with an anti-apoA-I immunosorbent. ApoA-I, apoA-II, apoA-IV, apoB, apoC-III, apoD, apoE, apoH, lecithin: cholesterol acyltransferase (LCAT), cholesteryl ester transfer (CET) protein, proline-rich protein, and a protein of Mr 59,000 were detected in the A-IVLp. These particles contain more than 20% triglycerides (lipid mass). ApoA-IV-containing particles that were isolated from plasma are heterogeneous in size, consisting of two major populations with Stokes' diameters of 10.3 nm and 9.3 nm. Both subpopulations of A-IVLp contain LCAT and CET activities and promote cholesterol efflux from cholesterol-preloaded adipose cells. These data support the hypothesis that A-IVLp particles may be involved in reverse cholesterol transport.
The effects of olive oil, hydrogenated palm oil, and omega-3 fatty acid-enriched diets on megakaryocytes and platelets.
Authors: Schick P K , Wojenski C M , Walker J
Published: June 2011

Unsaturated fatty acids are thought to prevent thrombotic and arteriosclerotic disease, whereas saturated fatty acids are thought to increase the incidence of these disorders. However, the effects of these diets on megakaryocytes and platelets are not well understood. We compared the effects of diets enriched with 8.4% olive oil, 8.4% hydrogenated palm oil, or 10.2% omega-3 fatty acid ethyl esters on guinea pig megakaryocytes and platelets. In plasma, changes in fatty acid composition reflected the composition of each diet. However, in platelets and megakaryocytes, hydrogenated palm oil induced a decrease in 16:0 and an increase in 18:2 while the olive oil diet caused a marked increase in 18:1 and a decrease in most other fatty acids. The differences in the effects of the diets on cellular versus plasma fatty acids suggest that megakaryocytes and platelets have an extensive capacity to regulate their fatty acid composition. Thrombocytosis occurred with the omega-3 fatty acid-enriched diet: 12.9 +/- 1.78 x 10(5) compared with 7.45 +/- 1.08 x 10(5) platelets per microliter of platelet-rich plasma in control animals. There was an increase in megakaryocyte size, ploidy, and morphological stage (cytoplasmic maturation) with the omega-3 fatty acid-enriched diet but not with the other diets. The omega-3 fatty acid-enriched diet decreased platelet thromboxane production while the other diets had no effect. Platelet hypersensitivity was suggested in collagen aggregation studies with olive oil but not with the hydrogenated palm oil diet. Although saturated fatty acid diets are thought to be atherogenic, this diet had no affect on platelet function.(ABSTRACT TRUNCATED AT 250 WORDS)
Increased fibrin turnover and high PAI-1 activity as predictors of ischemic events in atherosclerotic patients. A case-control study. The PLAT Group.
Authors: Cortellaro M , Cofrancesco E , Boschetti C , Mussoni L , Donati M B , Cardillo M , Catalano M , Gabrielli L , Lombardi B , Specchia G
Published: June 2011

A case-control comparison within the framework of the prospective, multidisciplinary PLAT Study was performed to assess whether altered baseline fibrinolytic variables were associated with an elevated risk of ischemic thrombotic events in patients with documented coronary, cerebral, and/or peripheral atherosclerotic disease. Fibrinogen, D-dimer, tissue plasminogen activator (t-PA) antigen, and fibrinolytic activity before and after venous stasis (delta = difference between the two values), t-PA inhibitor, and lipid levels in 60 atherosclerotic patients with a thrombotic event during the first year of follow-up were compared with those in 94 atherosclerotic patients without such events, who were matched for age, sex, and diagnosis at enrollment. Events were associated with a higher release of delta t-PA antigen (P = .047), higher D-dimer (P = .024), and higher t-PA inhibitor (P = .001) levels. delta Fibrinolytic activity was correlated inversely with t-PA inhibitor (P < .01) and triglycerides (P < .05). D-Dimer was also correlated with systolic blood pressure (P < .01). Atherosclerotic patients at higher risk of thrombotic ischemic events are characterized by increased fibrin turnover and impaired fibrinolytic activity due to high t-PA inhibitor levels. This hemostatic disequilibrium may participate with conventional risk factors such as elevated triglyceride levels and systolic blood pressure in the multifactorial mechanism of ischemic sequelae in patients with preexisting vascular atherothrombotic disease.
Age influences the replicative activity and the differentiation features of cultured rat aortic smooth muscle cell populations and clones.
Authors: Bochaton-Piallat M L , Gabbiani F , Ropraz P , Gabbiani G
Published: June 2011

The replicative activity and the differentiation features of aortic smooth muscle cells (SMCs) cultured as whole populations or clones from newborn (4-day-old), young adult (6-week-old), and old (18-month-old) rats were studied by means of cell counting, [3H]thymidine incorporation, and measurement of the expression of cytoskeletal proteins and mRNAs. In whole populations at the fifth passage, replicative activity increased and differentiation features (ie, expression of alpha-smooth muscle actin, desmin, and smooth muscle myosin heavy chains) decreased with increasing age of the donor animal. SMC clones derived from newborn or young adult rats showed more differentiated cytoskeletal features than their parental populations; however, most SMC clones from old rats showed dedifferentiated features similar to those observed in their parental populations. Our results suggest that (1) SMCs of the rat aortic media behave as a heterogeneous population; (2) cultured whole SMC populations behave differently from clones as far as their replicative activity and differentiation features are concerned; and (3) SMCs derived from old rats, whether grown as whole populations or as clones, dedifferentiate more substantially and replicate more actively than corresponding cultures from newborn or young adult rats when submitted to the same amount of serum growth factors; these differences may play a role in arterial development as well as in the formation and evolution of the atheromatous plaque.
Underexpression of the apolipoprotein E4 isoform in an Italian population.
Authors: James R W , Boemi M , Giansanti R , Fumelli P , Pometta D
Published: June 2011

Apolipoprotein (apo) E polymorphism was examined in a population of Italian blood donors. A significantly reduced frequency of the epsilon 4 allele was observed in comparison to a combined Caucasian population. Apo E polymorphism was also associated with significant differences in plasma lipid and lipoprotein levels. Notably, total and low-density lipoprotein cholesterol as well as triglycerides were increased, whereas high-density lipoprotein cholesterol was decreased in carriers of the E4 isoform. This is the first report of a significantly lower frequency of the apo E4 isoform in a European population. The reduced occurrence of an apo E isoform, which is associated with a more atherogenic lipid/lipoprotein profile, may be a contributory factor to the relatively lower incidence of cardiovascular disease in the Italian population.
Dietary n-3 polyunsaturated fatty acids prevent the development of atherosclerotic lesions in mice. Modulation of macrophage secretory activities.
Authors: Renier G , Skamene E , DeSanctis J , Radzioch D
Published: June 2011

We examined the effects of dietary n-3 polyunsaturated and saturated fatty acids on the development of the atherogenic process in mice and on the macrophage ability to secrete several effector molecules that may be involved in the atherogenic process. The secretion of inflammatory proteins such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) and the production of lipoprotein lipase (LPL), nitrogen oxide (NO2), and prostaglandin E2 (PGE2) were evaluated in peritoneal macrophages isolated from atherosclerosis-susceptible C57BL/6J mice. The mice were assigned at random to three experimental groups: the first group was fed a semi-defined control diet (control diet); the second group was maintained on the control diet supplemented with 10% menhaden oil (menhaden diet); and the third group received the control diet supplemented with 10% palm oil plus 2% cholesterol (saturated fat diet). Macrophages derived from mice fed the menhaden diet showed a suppression of their basal TNF-alpha mRNA expression and production. They also presented a dramatically decreased ability to express TNF-alpha and IL-1 beta mRNAs in response to exposure to lipopolysaccharide (LPS) compared with the macrophages from the control group. LPL mRNA and protein expression were downregulated after 6 and 15 weeks of menhaden-diet feeding. Significantly higher NO2 production in response to interferon gamma was found, both after 6 and 15 weeks of diet feeding, in the menhaden group compared with the control group. In addition, prostaglandin production and macrophage tumoricidal activity in response to LPS were decreased in this group compared with the control group. Macrophages derived from the saturated fat group did not show any significant alterations in TNF-alpha, LPL, NO2, or PGE2 secretion compared with controls. Interestingly, we observed a progressive increase of the LPS-induced IL-1 beta gene expression and secretion among macrophages harvested from mice receiving the dietary supplement of saturated fatty acids. At 6 and 15 weeks histologic examination of the atherosclerotic lesions did not reveal any important lesions in the control and menhaden groups, whereas a gradual development of fatty streaks was observed in the menhaden experimental diets for 10 additional weeks resulted in a major development of lesions in the control group, whereas only slight lesions were observed in the menhaden group.(ABSTRACT TRUNCATED AT 400 WORDS)
Studies of factor Xa/phospholipid-induced intravascular coagulation in rabbits. Effects of immunodepletion of tissue factor pathway inhibitor.
Authors: Warn-Cramer B J , Rapaport S I
Published: June 2011

In earlier studies from this laboratory evidence was obtained for a physiological function of tissue factor pathway inhibitor (TFPI) as a regulator of hemostasis capable of preventing thrombotic complications that might otherwise result from exposure of blood to trace amounts of tissue factor (TF). However, it was not possible to conclude that the protective effect of TFPI stemmed solely from inhibition of factor VIIa/TF catalytic activity, since TFPI neutralizes stoichiometric amounts of factor Xa in forming an inhibited factor Xa/TFPI/factor VIIa/TF complex. Therefore, we examined the effects of immunodepletion of TFPI on the extent of coagulation initiated in rabbits by exposure to factor Xa and phospholipid in the absence of TF. In one experimental approach, factor Xa was generated endogenously with the factor X-activating fraction of Russell's viper venom (0.33 microgram/kg) in rabbits receiving an infusion of phosphatidylcholine/phosphatidylserine (PCPS) vesicles, 1 mg/kg over 2 hours. In a second approach, rabbits were injected with a complex of factor Xa (0.75 microgram/kg) and PCPS (12.5 micrograms/kg). In contrast with the observed sensitization of TFPI-depleted rabbits to TF-induced coagulation, TFPI-depleted rabbits were not sensitized to coagulation initiated by factor Xa and phospholipid in the absence of TF. These data support the conclusion that the physiological function of TFPI in regulating TF-dependent coagulation stems primarily from its ability to inhibit factor VIIa/TF catalytic activity.
Parental history of early myocardial infarction is associated with decreased levels of lipoparticle AI in adolescents.
Authors: Amouyel P , Isorez D , Bard J M , Goldman M , Lebel P , Zylberberg G , Fruchart J C
Published: June 2011

A family history of coronary heart disease (CHD) is a known risk factor for CHD. To investigate the possible role of lipoprotein particles in the relationship between family history of CHD and risk of CHD, we performed a case-control study in a sample of adolescents. The case group consisted of 97 adolescents whose parents had suffered a verified myocardial infarction before the age of 55 years. The control group was composed of 194 subjects without any family history of CHD. One case patient was matched to two control subjects for gender, age, and body mass index. In both groups, plasma lipid variables were measured, including total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C) low-density lipoprotein cholesterol, apolipoprotein (apo)AI, apoB, apoAI-containing lipoprotein particles without apoAII (LpAI) and with apoAII, and apoB-containing lipoprotein particles with apoE and with apoCIII. Adolescents with a family history of early myocardial infarction had lower plasma levels of HDL-C (P < .0001), apoAI (P < .01), and LpAI (P < .0001) than control subjects (adjusted for gender, age, body mass index, smoking habits, and oral contraceptive use). No other differences were statistically significant between case and control subjects. The analysis was repeated separately for male and female subjects. In young men, the best predictor of family history of early myocardial infarction was the LpAI plasma level, whereas in young women it was the HDL-C plasma level. Decreased levels of HDL-C and LpAI lipoprotein particles explain part of the relationship between parental history of early myocardial infarction and CHD risk.
Familial hypoalphalipoproteinemia in premature coronary artery disease.
Authors: Genest J , Bard J M , Fruchart J C , Ordovas J M , Schaefer E J
Published: June 2011

Hypoalphalipoproteinemia (HA) is a common finding in patients with premature coronary artery disease. To characterize the common familial forms of HA, we studied 102 families of probands with premature coronary artery disease; 40 probands (39.2%) had HA. Of these, 25 had at least one first-degree relative affected with HA; 11 had familial hypertriglyceridemia with HA (FTgHA); 10 had familial combined hyperlipidemia (FCH); and 4 had familial HA (FHA) with no other lipoprotein abnormalities. In the remaining 15 families, no lipoprotein abnormalities were observed in first-degree relatives. We measured apolipoprotein (apo) A-I, B, C-III, and E levels as well as lipoprotein particle (Lp) levels of LpA-I (containing apoA-I only), LpA-I:A-II (containing both apoA-I and A-II), LpB:E, and LpB:C-III. Compared with a reference group of healthy men (n = 103) and women (n = 106), probands with familial forms of HA had lower high-density lipoprotein cholesterol levels by selection criteria. Triglyceride levels were higher in FTgHA and FCH probands than in the reference group or FHA subjects. Despite selection of FTgHA and FCH by low-density lipoprotein (LDL) cholesterol, the latter was not significantly different between the three groups and the reference group. ApoA-I levels were decreased in FCH, FHA, and FTgHA probands, and LpA-I and LpA-I:A-II were lower in FHA and FTgHA probands. ApoB levels were significantly higher in all familial HA groups compared with the reference group, being highest in FCH individuals, but not significantly higher between FCH, FTgHA, or FHA probands. LpB:E levels were higher in the FCH and FTgHA groups than in the reference group. There were no significant differences between groups for apoE, apoC-III, and LpB:C-III. LDL particle size was smaller in all three forms of FHA, which, in combination with higher apoB levels, reflects an increased number of smaller, denser LDL particles. Affected children had, on average, higher apoB and LpB:E levels than nonaffected siblings. Our data suggest that common forms of FHA in subjects with coronary artery disease represent a spectrum of overlapping disorders characterized by an increase in apoB-containing lipoproteins, especially LpB:E particles, and smaller, denser LDL particles. When using appropriate age- and gender-adjusted cutpoints, approximately half the offspring (in young adulthood) appeared to be affected.
Association of hemostatic variables with prevalent cardiovascular disease and asymptomatic carotid artery atherosclerosis. The Atherosclerosis Risk in Communities (ARIC) Study Investigators.
Authors: Folsom A R , Wu K K , Shahar E , Davis C E
Published: June 2011

The relation of hemostatic factor levels to the occurrence of cardiovascular disease is incompletely established. The Atherosclerosis Risk in Communities Study measured fibrinogen, factor VII, factor VIII, von Willebrand factor, antithrombin III, protein C, activated partial thromboplastin time, and other cardiovascular risk factors in nearly 15,000 men and women aged 45 to 64. This analysis assessed the relations of these hemostatic factors with prevalent cardiovascular disease and asymptomatic carotid artery intimal-medial thickness measured by B-mode ultrasound. Compared with participants without cardiovascular disease, those with cardiovascular disease had higher levels of fibrinogen, factor VIII, and von Willebrand factor in both sexes. The other hemostatic factors were less consistently associated with prevalent cardiovascular disease. Only fibrinogen was associated with carotid intimal-medial thickness. Adjusted for age, race, and field center, the odds ratio for carotid wall thickness in the 90th percentile or greater, compared with < 50th percentile, for each SD higher fibrinogen concentration (65 mg/dL) was 1.42 (95% confidence interval, 1.25, 1.62) in men and 1.43 (1.25, 1.64) in women. This population-based study provides further evidence that fibrinogen and possibly factor VIII and von Willebrand factor are risk factors for cardiovascular disease.
A chimeric murine/human antibody Fab fragment directed against the platelet GPIIb/IIIa receptor enhances and sustains arterial thrombolysis with recombinant tissue-type plasminogen activator in baboons.
Authors: Kohmura C , Gold H K , Yasuda T , Holt R , Nedelman M A , Guerrero J L , Weisman H F , Collen D
Published: June 2011

Inhibition of the platelet glycoprotein (GP) IIb/IIIa receptor with the murine monoclonal antibody 7E3 abolishes ex vivo platelet aggregation, reduces thrombogenicity, and sustains arterial recanalization with recombinant tissue-type plasminogen activator (rt-PA). A chimeric murine/human Fab fragment of 7E3 (c7E3-Fab) has a markedly reduced immunogenicity, but its potency as an adjunct for thrombolysis with rt-PA has not been evaluated. The effects of a single intravenous bolus injection of aspirin (17 mg/kg) or c7E3-Fab (0.45 mg/kg) on thrombolysis and reocclusion induced with rt-PA were studied in groups of six baboons with femoral arterial thrombosis and superimposed high-grade stenosis. This dose of c7E3-Fab blocked 96 +/- 1% of the platelet GPIIb/IIIa receptors and abolished ADP-induced platelet aggregation. Bolus intravenous injections of rt-PA (0.25 mg/kg) were repeated at 15-minute intervals until reperfusion occurred (maximum of four injections). In the aspirin group, reperfusion was obtained within 51 +/- 16 minutes (mean +/- SD) but was rapidly followed by reocclusion within 6 +/- 9 minutes and by cyclic reflow and reocclusion. In the c7E3-Fab group, reperfusion was obtained within 25 +/- 8 minutes (P < .01 versus aspirin group) and was associated with a delayed reocclusion of 63 +/- 63 minutes (P < .05 versus aspirin group). Template bleeding times remained unchanged in the aspirin/rt-PA group but were markedly prolonged (to > 30 minutes) in the c7E3-Fab/rt-PA group.(ABSTRACT TRUNCATED AT 250 WORDS)
Impact of weight loss on plasminogen activator inhibitor (PAI-1), factor VII, and other hemostatic factors in moderately overweight adults.
Authors: Folsom A R , Qamhieh H T , Wing R R , Jeffery R W , Stinson V L , Kuller L H , Wu K K
Published: June 2011

Based on previous cross-sectional findings, we hypothesized that weight loss could improve several hemostatic factors associated with cardiovascular disease. In a randomized controlled trial, moderately overweight men and women were assigned to one of four weight loss treatment groups or to a control group. Measurements of plasminogen activator inhibitor-1 (PAI-1) antigen, tissue-type plasminogen activator (t-PA) antigen, D-dimer antigen, factor VII activity, fibrinogen, and protein C antigens were made at baseline and after 6 months in 90 men and 88 women. Net treatment weight loss was 9.4 kg in men and 7.4 kg in women. There was no net change (p > 0.05) in D-dimer, fibrinogen, or protein C with weight loss. Significant (p < 0.05) decreases were observed in the combined treatment groups compared with the control group for mean PAI-1 (31% decline), t-PA antigen (24% decline), and factor VII (11% decline). Decreases in these hemostatic variables were correlated with the amount of weight lost and the degree that plasma triglycerides declined; these correlations were stronger in men than women. These findings suggest that weight loss can improve abnormalities in hemostatic factors associated with obesity.
Smooth muscle cell immediate-early gene and growth factor activation follows vascular injury. A putative in vivo mechanism for autocrine growth.
Authors: Miano J M , Vlasic N , Tota R R , Stemerman M B
Published: June 2011

To understand the molecular events governing smooth muscle cell (SMC) proliferation in vivo, immediate-early gene (IEG) expression was assessed and related to growth factor ligand and receptor mRNA and SMC DNA synthesis after aortic injury. Balloon catheter injury evoked increases in SMC c-myc and thrombospondin (tsp) within 2 hours. The induction of these IEGs was followed by elevated transcripts to platelet-derived growth factor-A (PDGF-A), transforming growth factor-beta 1 (TGF-beta 1) and a basic fibroblast growth factor (bFGF) receptor. Whereas PDGF type-beta receptor mRNA was demonstrated in SMCs from control and balloon-injured aortas, no detectable signal was observed for the PDGF type-alpha receptor. To explore the potential linkage between IEG products and growth factor mRNA expression, cycloheximide was employed to block early protein synthesis after balloon injury. Induction of PDGF-A and TGF-beta 1 was attenuated by cycloheximide, but bFGF induction was unaffected. Moreover, cycloheximide superinduced IEGs and revealed PDGF-B transcripts, which were otherwise undetected. Seven days after aortic injury, a spontaneous increase in c-myc and tsp mRNA was noted. This IEG reactivation was followed 12 hours later by a twofold increase in SMC DNA synthesis. These findings corroborate an autocrine mode of SMC proliferation in vivo and suggest the IEG products may control such growth by stimulating growth factor genes.
A new anti-inflammatory leucine derivative, NPC-15669, inhibits growth of cultured human aortic smooth muscle cells.
Authors: Bennett R L , Navab M , Demer L L , Fogelman A M
Published: June 2011

We have observed that NPC-15669, a leucine derivative with anti-inflammatory activity, reduced the proliferation of human aortic smooth muscle cells (HASMCs) in culture. We used a colorimetric assay and tritiated thymidine to measure the cell density and proliferation of HASMC cultures treated with this agent. We also studied the effect of NPC-15669 on the proliferation and migration of human aortic endothelial cells (HAECs). Subconfluent HASMC cultures were growth arrested for 2 days. On the third day, growth was stimulated with either growth media (medium M199 containing 10% fetal bovine serum [FBS]), human platelet-derived growth factor (hPDGF), or fibroblast growth factor (FGF) in the absence or presence of NPC-15669 (0.1-50 microM). Regardless of the stimulating agent for HASMCs (FBS, hPDGF, or FGF), NPC-15669 at concentrations of 10-25 microM caused a significant reduction in thymidine incorporation (36.7% and 77.2% in 10 microM and 25 microM, respectively; p < 0.005) and cell density (25-87%, p < 0.001) compared with control. NPC-15669 did not, however, have an effect on the rate of proliferation or migration of HAECs, even at concentrations up to 50 microM. Two other anti-inflammatory agents, aspirin and dexamethasone, caused substantially and significantly less inhibition, even at high concentrations (50 and 25 microM, respectively). This study demonstrates that in vitro, NPC-15669 significantly inhibits HASMC proliferation but has no effect on proliferation or migration of HAECs.
Localization of von Willebrand factor binding domains to endothelial extracellular matrix and to type VI collagen.
Authors: Denis C , Baruch D , Kielty C M , Ajzenberg N , Christophe O , Meyer D
Published: June 2011

We have recently shown that von Willebrand factor (vWF) binds to endothelial and fibroblastic extracellular matrixes (ECM) in a dose-dependent, specific, and saturable way. To localize the domain on the vWF subunit responsible for this interaction, purified proteolytic fragments of vWF were compared for their ability to inhibit 125I-vWF binding to ECM. A tryptic dimeric fragment of 116 kD (T116), extending from amino acid (aa) residues 449 to 728, produced a significant inhibition of 125I-vWF binding to the ECM. In contrast, P34 (aa 1-272), SpI (aa 911-1,365), and SpII (aa 1,366-2,050) had no significant effect on 125I-vWF binding to the ECM. Using an immunofluorescence technique, we identified type VI collagen and heparan sulfate in the endothelial ECM. 125I-vWF was found to bind specifically to purified type VI collagen. Unlabeled vWF and SpIII were able to completely inhibit 125I-vWF binding to type VI collagen. T116 and SpI appeared as competitors of this interaction, whereas P34 and SpII were not. Our data suggest that vWF binds to the endothelial ECM through the T116 fragment and that T116 and SpI each contain a binding site for type VI collagen. Heparin is known to be a vWF ligand, but did not appear as a competitor of vWF binding to the ECM, nor did heparan sulfate.