bluuebunny/crossref_metadata_2025 huggingface dataset:
Compared With Dietary Monounsaturated and Saturated Fat, Polyunsaturated Fat Protects African Green Monkeys From Coronary Artery Atherosclerosis
Authors: Rudel Lawrence L. , Parks John S. , Sawyer Janet K.
Published: June 2011

Abstract
Atherogenic diets enriched in saturated, n-6 polyunsaturated, and monounsaturated fatty acids were fed to African green monkeys for 5 years to define effects on plasma lipoproteins and coronary artery atherosclerosis. The monkeys fed polyunsaturated and monounsaturated fat had similar plasma concentrations of LDL cholesterol, and these values were significantly lower than for LDL in the animals fed saturated fat. Plasma HDL cholesterol concentrations were comparable in animals fed saturated and monounsaturated fat and were significantly higher than in animals fed polyunsaturated fat. Thus, the monounsaturated fat group had the lowest LDL/HDL ratio. LDL particle size was largest in the saturated and monounsaturated fat groups, significantly larger than in the polyunsaturated fat group. LDL particle enrichment with cholesteryl oleate was the greatest in the animals fed monounsaturated fat, next greatest in the saturated fat–fed animals, and was least in the polyunsaturated fat–fed animals. Coronary artery atherosclerosis as measured by intimal area was less in the polyunsaturated fat compared with the saturated fat groups, was less in the animals fed polyunsaturated fat compared with the monounsaturated fat–fed animals, but did not differ between the monounsaturated and saturated fat groups. Cholesteryl ester, particularly cholesteryl oleate, accumulation in the coronary arteries was also similar between groups fed monounsaturated and saturated fat but was minimal in the animals fed polyunsaturated fat. In sum, the monkeys fed monounsaturated fat developed equivalent amounts of coronary artery atherosclerosis as those fed saturated fat, but monkeys fed polyunsaturated fat developed less. The beneficial effects of the lower LDL and higher HDL in the animals fed monounsaturated fat apparently were offset by the atherogenic shifts in LDL particle composition. Dietary polyunsaturated fat appears to result in the least amount of coronary artery atherosclerosis because it prevents cholesteryl oleate accumulation in LDL and the coronary arteries in these primates.
LDL Size and Subclass Pattern in Mexico City Residents and San Antonio Mexican Americans
Authors: Haffner Steven M. , González Clicerio , Miettinen Heikki , Howard Barbara V. , Stern Michael P.
Published: June 2011

Abstract
Recent studies suggest that a relative abundance of small dense LDL is a risk factor for coronary heart disease. We compared LDL size in Mexico City residents (n=191) and San Antonio Mexican Americans (n=282), two genetically similar populations that differ markedly in dietary behaviors: in Mexico City ≈62% of calories are from carbohydrate and ≈19% from fat, and in San Antonio ≈40% of calories are from carbohydrate and ≈40% from fat. Mean LDL size in Mexico City was 258.6±0.9 Å, and in San Antonio, 255.9±0.6 Å (
P
=.013). After adjustment for the higher triglyceride and lower HDL cholesterol levels (the two most important predictors of LDL size) in Mexico City, LDL size was significantly lower in San Antonio than in Mexico City by −8.33±0.84 Å (
P
<.001). Our data suggest that the higher triglyceride concentrations in Mexico City residents that are associated with a higher carbohydrate diet may not be associated with atherogenic changes in LDL.
Effects of 1 Year of Growth Hormone Therapy on Serum Lipoprotein Levels in Growth Hormone–Deficient Adults
Authors: Johannsson Gudmundur , Oscarsson Jan , Rosén Thord , Wiklund Olov , Olsson Gun , Wilhelmsen Lars , Bengtsson Bengt-Åke
Published: June 2011

AbstractWe investigated the influence of gender and apoE and apo(a) phenotypes as well as the effect of the metabolic effects of growth hormone (GH) on the effect of GH therapy on serum lipoprotein concentrations in GH-deficient (GHD) adults. Forty-four consecutive patients, 30 men and 14 women aged 46.5 (range, 19 to 76) years with GHD due mainly to pituitary tumors, were treated with recombinant human GH for 12 months. Serum concentrations of lipoproteins, insulin, thyroxine, and insulin-like growth factor–I were determined, body composition was assessed by bioelectrical impedance, and apo(a) and apoE phenotypes were analyzed. Lipoprotein(a) [Lp(a)] concentrations in the GHD subjects were compared with a gender- and apo(a) phenotype–matched control group. After 12 months of GH treatment, the total cholesterol, LDL cholesterol, and apoB concentrations decreased, the HDL cholesterol and apoE concentrations increased, and the apoA-I and triglyceride concentrations were unchanged. Before treatment, the Lp(a) concentration was similar to that in the control group. However, after 12 months of treatment, the Lp(a) concentration had increased by 44% and 101% above baseline and the control group, respectively. Men and women responded differently to GH, with a more marked increase in Lp(a) concentration and fat-free mass and a more pronounced decrease in body-fat mass in men. Apo(a) phenotypes had no major influence on the effect of GH therapy. The only significant difference between apoE phenotypes was a higher baseline Lp(a) concentration among apoE4 heterozygotes. Changes in body composition, insulin, insulin-like growth factor–I, and thyroxine concentrations explained at most 27% of the changes that occurred in serum lipoprotein levels during GH treatment. The effects of GH therapy on serum lipoprotein levels and body composition in GHD adults were dependent in part on gender or current sex hormone therapy. However, no major influence by apo(a) or apoE phenotype or changes in metabolic variables were detected on the effects of GH therapy on serum lipoprotein levels.
Apolipoprotein A-I Deficiency
Authors: Ng Dominic S. , Vezina Camilla , Wolever Thomas S. , Kuksis Arnis , Hegele Robert A. , Connelly Philip W.
Published: June 2011

Abstract
Familial HDL deficiencies are associated with variable susceptibility to premature coronary heart disease, but the mechanism underlying this association remains poorly understood. Three homozygotes with isolated complete apo A-I deficiency caused by an autosomal codominant apo A-I Q[−2]X mutation and one heterozygote developed coronary heart disease before age 40 years. We characterized the effects of this mutation on lipoprotein metabolism. LDL FC, phospholipid, and apo B were all significantly higher in homozygotes than in heterozygotes. The HDLs of the heterozygotes were apo A-I poor relative to apo A-II. Lecithin-cholesterol acyltransferase activity was 59% lower in homozygotes than in normal subjects or heterozygotes. Cholesteryl ester transfer activity was increased in a homozygote compared with a normolipidemic control subject. Postprandial lipid metabolism was studied in one homozygote and one heterozygote. Postprandial TG response in the homozygote was significantly exaggerated, while residual plasma HDL level remained unaffected. The homozygote also had delayed clearance of retinyl ester, a marker of chylomicron remnant metabolism. Thus, homozygosity and heterozygosity for apo A-I Q[−2]X are associated with qualitative, as well as quantitative, disturbances in plasma HDLs, LDLs, lipid-modifying enzyme activities, and postprandial retinyl ester metabolism. The observed elevation of atherogenic lipoproteins and reduction in antiatherogenic lipoproteins in the affected members of the apo A-I Q[−2]X kindred are consistent with the primary deficiency in apo A-I having pleiotropic effects that markedly enhance susceptibility for coronary heart disease.
Biochemical Prototype for Familial Thrombosis
Authors: Kalafatis Michael , Lu Deshun , Bertina Rogier M. , Long George L. , Mann Kenneth G.
Published: June 2011

Abstract
Resistance to activated protein C (APC) is associated with a single amino acid substitution in factor V (Arg
506
→Gln, factor V Leiden) that results in delayed inactivation of the molecule by APC. The mutation is present in 20% of patients with a first episode of deep venous thrombosis. Arterial and venous thromboses are also associated with the type II protein C deficiency (protein C
Vermont
). In protein C
Vermont
, the substitution Glu
20
→Ala alone (rPC
γ20A
) is responsible for the defective anticoagulant properties of PC
Vermont
. It was recently established that a thrombotic episode occurred in 73% of family members who are heterozygous for both a functional protein C gene mutation and the factor V Leiden mutation. We evaluated the molecular defect that would accrue in the combined deficiency state of factor V
R506Q
/Va
R506Q
and rAPC
γ20A
using recombinant APC and natural purified factor V
R506Q
from patients homozygous for the Arg
506
→Gln substitution. While wild-type recombinant APC (rAPC) slowly cleaves and inactivates factor V
R506Q
and factor Va
R506Q
, minimal cleavage of membrane-bound factor V
R506Q
and Va
R506Q
by rAPC
γ20A
at Arg
306
and Arg
679
occurs, and no loss in cofactor activity is observed. Our data demonstrate that rAPC
γ20A
cannot inactivate either factor V
R506Q
or factor Va
R506Q
at biologically relevant rates because of impaired cleavage at Arg
306
and Arg
679
. The result is a stable procofactor and stabilization of an active cofactor in patients possessing both mutations. Our data provide a prototype of familial thrombosis that most likely would be manifested in vivo by the occurrence of massive thrombosis.
Relation of a Postmortem Renal Index of Hypertension to Atherosclerosis in Youth
Authors: McGill Henry C. , Strong Jack P. , Tracy Richard E. , McMahan C. Alex , Oalmann Margaret C.
Published: June 2011

Abstract
In a cooperative multicenter study, Pathobiological Determinants of Atherosclerosis in Youth, of 1164 young men 15 through 34 years of age who died of external causes and were autopsied in forensic laboratories, we measured atherosclerosis of the aorta and the right coronary artery. Using the ratio of intimal thickness to outer diameter of the small renal arteries to predict mean arterial pressure (MAP) during life, we classified the cases as either normotensive (MAP <110 mm Hg) or hypertensive (MAP ≥110 mm Hg). By this criterion, the prevalence of hypertension in blacks was 16%; in whites, 12%. Hypertension was associated directly with blood level of glycohemoglobin (an indicator of blood glucose concentration) and with body mass index (BMI) but inversely with thickness of the panniculus adiposus.

Among hypertensive compared with normotensive cases, the extent of raised lesions (mainly fibrous plaques) was greater in the aortas of 30- to 34-year-old men and in the right coronary arteries of 25- to 34-year-old men. The prevalence of raised lesions involving 5% or more of the intimal surface was twofold greater in the aortas and right coronary arteries of hypertensive men throughout the 15-to-34–year age span of the study cases. The association of hypertension with raised lesions was not accounted for by adjusting for glycohemoglobin level, BMI, or thickness of the panniculus adiposus. Hypertension is associated with accelerated atherosclerosis in youth, particularly fibrous plaques.
Functional and Anatomic Evaluation of Carotid Atherothrombosis
Authors: Moriwaki Hiroshi , Matsumoto Masayasu , Handa Nobuo , Isaka Yoshinari , Hashikawa Kazuo , Oku Naohiko , Nakamura Masaichi , Kamada Takenobu , Nishimura Tsunehiko
Published: June 2011

Abstract
We examined the relation between in vivo thrombogenicity and the morphology of carotid lesions to clarify the role of platelet deposition in carotid atherothrombosis. We evaluated 60 subjects (120 carotid bifurcations) who had at least one established risk factor for atherosclerosis by using indium 111 platelet scintigraphy and high-resolution B-mode ultrasonography. We evaluated platelet accumulation in the carotid arterial wall by means of a dual-tracer method that used In 111–labeled platelets and technetium 99m–labeled human serum albumin. The tracer accumulation was assessed both visually and semiquantitatively by using the platelet accumulation index, ie, the ratio of radioactivity of the amount of In 111–labeled platelets deposited on the vascular wall to the amount of radioactivity in labeled platelets circulating in the blood pool. The morphology of the carotid lesions was analyzed with B-mode ultrasonography in terms of the presence of ulceration, the maximum percent stenosis, the echogenicity of plaque, and the plaque score, which indicates the severity of systemic atherosclerosis. Platelet accumulation increased with increase in plaque score (
P
<.01), and the magnitude of platelet accumulation was significantly greater in lesions with ulceration than in those without (
P
<.05). The platelet accumulation index in vessels with plaque showed a very weak but significant correlation with maximum percent stenosis (
r
=.28,
P
<.05) and a stronger correlation with the unilateral plaque score (
r
=.42,
P
<.0001). Analysis of the echogenicity of plaque showed that heterogeneous plaque had a high frequency of accumulating platelets. Platelet accumulation was related to the surface characteristics and severity of carotid lesions, especially in the presence of ulceration.
Adenovirus-Mediated Gene Transfer to Normal and Atherosclerotic Arteries
Authors: Ríos C. David , Ooboshi Hiroaki , Piegors Donald , Davidson Beverly L. , Heistad Donald D.
Published: June 2011

Abstract
Previous studies of gene transfer to blood vessels in vivo have relied on intraluminal, catheter-based methods for delivery of adenoviral and other vectors. In this study, topical application of a replication-deficient adenoviral vector was used as an alternative method of gene transfer to the vessel wall. We administered recombinant adenovirus (1.0 to 1.5×10
10
pfu/mL) containing the nuclear targeted bacterial β-galactosidase gene topically to arteries in normal and atherosclerotic cynomolgus monkeys. Topical administration was achieved by injection of adenoviral suspension within the periarterial sheath. Segments of femoral and carotid arteries were examined histochemically after staining with 5-bromo-4-chloro-3-indolyl-β-
d
-galactopyranoside 1 day after treatment with the adenovirus. After topical administration of virus, β-galactosidase activity was observed in ≈20% of cells in the adventitia in both normal and atherosclerotic arteries. There was no detectable β-galactosidase activity in cells of the intima or media. Thus, topical application provides an alternative method for gene transfer to blood vessels in vivo. This approach, which does not require interruption of blood flow and does not disrupt the endothelium, may be useful for studies of vascular biology and perhaps gene therapy in both normal and atherosclerotic vessels.
Oxidized LDL–Induced Microvascular Dysfunction
Authors: Liao Lianxi , Aw Tak Yee , Kvietys Peter R. , Granger D. Neil
Published: June 2011

Abstract
Human LDLs oxidized with Cu
2+
are known to promote leukocyte–endothelial cell adhesion (LECA) and albumin leakage in postcapillary venules. The objective of this study was to compare the ability of LDL oxidized with Cu
2+
(Cu-LDL), phospholipase A
2
plus lipoxygenase (PLA
2
-LDL), horseradish peroxidase plus H
2
O
2
(HRP-LDL), or −OCl (−OCl-LDL) to promote (1)neutrophil–endothelial cell adhesion (NECA) in vitro and (2)LECA and albumin leakage in rat mesenteric venules. In vitro adhesion assays revealed that only Cu-LDL elicited a dose-dependent NECA response, whereas PLA
2
-LDL but not normal (N-LDL), HRP-LDL, or −OCl-LDL increased NECA at the highest concentration studied (670 μg/mL). The magnitude of the NECA responses elicited by the different forms of oxidized LDL was related to the degree of lipid peroxidation but unrelated to the level of protein oxidation. Local intra-arterial infusion of Cu-LDL, PLA
2
-LDL, or −OCl-LDL but not N-LDL elicited significant increases in leukocyte adherence and emigration, mast cell degranulation, and albumin leakage in rat mesenteric venules. The LECA induced by all forms of oxidized LDL was not accompanied by significant alterations of venular shear rate.
Dietary Fish Oil Supplementation Alters Leukocyte Function and Cytokine Production in Healthy Women
Authors: Wallace Julie M. W. , Turley Eithne , Gilmore William S. , Strain John J.
Published: June 2011

Abstract
The effect of low-dose fish oil supplementation on cytokines and white cell function in women was investigated. Thirty-three healthy, nonsmoking women entered the double-blind study. For 4 weeks, 2.4 g of either fish oil (n=16) or fish oil with vitamin E (n=17) was added daily to the subjects’ otherwise unchanged diets. Venous blood samples were taken at the onset of the trial, after the supplementation period, and again after a 9-week washout period. Plasma levels of platelet-derived growth factor and myeloperoxidase were measured using immunoassays. The intracellular peroxidase content of white blood cells was measured using a staining technique. Platelet-derived growth factor levels were significantly lowered after supplementation (
P
≤.05). Intracellular peroxidase was increased (
P
≤.01), and extracellular myeloperoxidase levels were lowered (
P
≤.05). Taken together, these results suggest that the anti-inflammatory effect of fish oil may be due at least partly to alterations in white cell function and growth factor levels.
Quantification of Postprandial Triglyceride-Rich Lipoproteins in Healthy Men by Retinyl Ester Labeling and Simultaneous Measurement of Apolipoproteins B-48 and B-100
Authors: Karpe Fredrik , Bell Max , Björkegren Johan , Hamsten Anders
Published: June 2011

Abstract
The metabolism of chylomicrons, very-low-density lipoprotein (VLDL), and their remnants in the postprandial state was studied in normolipidemic healthy men by measuring apoB-48 and apoB-100 and retinyl palmitate (RP) in fractions of triglyceride-rich lipoproteins after a mixed meal type of oral fat load supplemented with vitamin A. ApoB-48 was present at low concentrations in the fasting plasma samples in most subjects and increased in response to the test meal in Svedberg’s flotation rate (Sf) >20 lipoprotein fractions. Concomitantly, the level of Sf 60 to 400 apoB-100 (large VLDL) had doubled at 3 hours and returned to baseline at 9 hours. The number of apoB-48–containing lipoprotein particles did not exceed 20% of the total number of apoB-containing lipoproteins contained in Sf 12 to 400 fractions at any time point after fat intake. The peak plasma level of RP was delayed compared with the peak plasma concentration of apoB-48, suggesting that retinyl ester labeling of chylomicrons is questionable as a means of quantifying postprandial triglyceride-rich lipoproteins of intestinal origin. Approximately 2000 and 4000 RP molecules were carried in each chylomicron particle in the 3- and 6-hour samples, respectively, in contrast to the remnant fractions in which 100 to 600 RP molecules were found for each lipoprotein particle. The limited RP exchange between lipoprotein particles indicates that the smaller intestinal lipoproteins do no originate primarily from larger Sf >400 chylomicron particles but instead are secreted directly into the Sf 20 to 400 fraction and subsequently converted to smaller chylomicron remnants. This notion was further substantiated by injection of RP-labeled postprandial plasma into fasting subjects with subsequent tracing of RP in fractions of triglyceride-rich lipoproteins.
Suppression of Plasma-Activated Factor VII Levels by Warfarin Therapy
Authors: Sakata Toshiyuki , Kario Kazuomi , Matsuo Takefumi , Katayama Yoshiaki , Matsuyama Tatsuo , Kato Hisao , Miyata Toshiyuki
Published: June 2011

Abstract
To investigate the effect of warfarin treatment on the early phase of tissue factor–induced coagulation, we measured plasma-activated factor VII (factor VIIa) levels by a direct fluorogenic assay in 74 cardiovascular disease patients on long-term oral anticoagulation. We divided the patients into three groups based on the international normalized ratio (INR). In the patients with INR ranges of <1.7 and 1.7 to 2.5, factor VIIa levels were 42% and 61% lower, respectively, than in age- and sex-matched controls. Factor VII coagulant activity (factor VIIc), factor VII antigen (factor VIIag), protein C, and factor X levels were also reduced to a similar extent in both groups. However, in patients with an INR >2.5, the factor VIIa level was not decreased compared with that at an INR of 1.7 to 2.5, although the factor VIIc, factor VIIag, factor X, and protein C levels were all decreased further. Although the precise relation between the reduction of factor VIIa levels and the increase of INR requires appropriately designed long-term clinical trials, our data suggest that an INR range of 1.7 to 2.5 is sufficient for the suppression of factor VIIa. During the long-term follow-up of three patients with congenital antithrombin III or protein C deficiency, the factor VIIa level was more responsive to changes in the warfarin dose than the INR, and there were generally no corresponding changes of the thrombin–antithrombin III complex (TAT) level. However, one patient showed a transient marked increase of factor VIIa during the discontinuation of warfarin that was accompanied by an increase in TAT. Based on these findings, factor VIIa could be useful for monitoring both hypercoagulable and hypocoagulable states.
Lipid and Lipoprotein Factors Associated With Variation in Lp(a) Density
Authors: Rainwater David L. , Ludwig M. J. , Haffner Steven M. , VandeBerg John L.
Published: June 2011

Abstract
To determine the facets of lipoprotein metabolism associated with variation in lipoprotein(a) [Lp(a)] density, we examined by density gradient ultracentrifugation 246 plasma samples exhibiting single apo(a) isoform band phenotypes. Estimated molecular weights of apo(a) isoforms ranged from 488 to 874 kD, and they accounted for approximately 80% of variation in Lp(a) density. After adjustment for variation in the protein composition, we found in univariate analyses that variation in residual Lp(a) density was associated with 10 different measures of lipoprotein size and concentration. Residual Lp(a) density was positively correlated with measures of apoB-containing lipoproteins and negatively correlated with measures of HDL. HDL size phenotypes were based on nondenaturing gradient gel electrophoresis fractions after staining for esterified cholesterol with Sudan black B and for apoA-I with immunoblotting methods. The HDL size variables in each case had higher correlations with residual Lp(a) density than did the HDL concentration measures. Stepwise regression analyses selected two lipoprotein variables (LDL density and HDL size) that were significantly correlated with residual Lp(a) density, and they accounted for approximately 35% of variation in density. The densities of LDL and Lp(a) were highly correlated, and additional stepwise regression analyses showed that they were similarly correlated with triglyceride concentration and with a measure of HDL size. Thus, with respect to residual Lp(a) density, the results show that small, dense Lp(a) particles are found under conditions leading also to small, dense LDL particles and to small, dense HDLs.
Aurintricarboxylic Acid Prevents Acute Rethrombosis in a Canine Model of Arterial Thrombosis
Authors: Strony John , Song Anly , Rusterholtz Lori , Adelman Burt
Published: June 2011

Abstract
Acute rethrombosis following thrombolytic therapy occurs in 5% to 25% of patients. We evaluated the effect of aurintricarboxylic acid (ATA), a triphenyl dye that blocks von Willebrand factor (vWF) binding to platelet glycoprotein Ib, on arterial reperfusion and acute rethrombosis following fibrinolytic therapy. Primary thrombosis was induced in the femoral arteries of anesthetized dogs by application of anodal current and partial arterial constriction. Blood flow was monitored with an electromagnetic flow probe, and primary thrombosis was considered to have occurred when blood flow was reduced to and remained at zero. Reperfusion was induced by intravenous streptokinase 30 minutes after thrombosis. Streptokinase reduced plasma fibrinogen levels from an average of 144 mg/dL to <5 mg/dL resulting in inhibition of ADP- and epinephrine-induced platelet aggregation ex vivo. Acute rethrombosis following reperfusion occurred within 37±18 (mean±SD) minutes in 89% (16/18) of animals receiving thrombolytic activator treatment. Histological examination of reoccluding thrombi revealed densely aggregated platelets and erythrocytes with no detectable fibrin. In the two other study groups, ATA was infused in conjunction with thrombolytic therapy (10 arteries) or at near completion of acute rethrombosis following fibrinolytic activator treatment (6 arteries). In each case ATA prevented rethrombosis. However, concomitant administration of ATA and thrombolytic therapy delayed restoration of blood flow. ATA had no direct effect on hemodynamics, thrombin time, platelet count, or platelet aggregation response to ADP, epinephrine, or collagen. These data indicate that inhibition of vWF–platelet glycoprotein Ib interaction is effective in preventing acute rethrombosis following thrombolytic therapy. However, the complex paradoxical effects of ATA on platelet activity should be considered when it, or agents of its class, are used as antithrombotics.
Aminoguanidine Has Both Pro-oxidant and Antioxidant Activity Toward LDL
Authors: Philis-Tsimikas Athena , Parthasarathy Sampath , Picard Sylvie , Palinski Wulf , Witztum Joseph L.
Published: June 2011

Abstract
We previously demonstrated that aminoguanidine (AMGN) was able to prevent oxidative modification of LDL. Initially, we thought that this occurred solely because AMGN trapped reactive breakdown products of lipid peroxidation and prevented apoB modification, similar to AMGN’s proposed ability to trap reactive glucose intermediates and prevent advanced glycosylation end-product formation. We now demonstrate that AMGN also displays dose-dependent pro-oxidant and antioxidant activity toward LDL. Moderate doses of AMGN (0.05 to 1.0 mmol/L) prevented lipid peroxidation in LDL exposed to copper. AMGN prevented the loss of polyunsaturated fatty acids and delayed or prevented conjugated-diene formation, both of which are sensitive indicators of lipid peroxidation. The same doses of AMGN also prevented apoB modification, a step distal to lipid peroxidation, as evidenced by the ability to (1) prevent fluorescence at 420 nm, (2) block enhanced electrophoretic mobility, and (3) prevent changes leading to enhanced macrophage uptake. Thus, AMGN inhibits LDL modification both by inhibiting lipid peroxidation as well as by trapping reactive breakdown products of lipid peroxidation. It was also demonstrated that for every LDL, there was also a very low dose of AMGN (about 0.01 mmol/L) that actually promoted lipid oxidation and subsequent protein modification. This activity of AMGN could be enhanced by increasing the content of lipid hydroperoxide in the LDL, eg, by aging or radioiodinating the LDL. Conversely, the pro-oxidant activity could be reduced by pretreatment of LDL with ebselen or vitamin E. We propose a mechanism by which AMGN effects pro-oxidant activity toward LDL at very low concentrations and antioxidant activity at higher concentrations and discuss the practical implications of these observations.
Lysine Modification of LDL or Lipoprotein(a) by 4-Hydroxynonenal or Malondialdehyde Decreases Platelet Serotonin Secretion Without Affecting Platelet Aggregability and Eicosanoid Formation
Authors: Malle Ernst , Ibovnik Anton , Leis Hans J. , Kostner Gerhard M. , Verhallen Peter F. J. , Sattler Wolfgang
Published: June 2011

Abstract
The effects of lysine-modified atherogenic plasma lipoproteins, known to be constituents of human atherosclerotic plaques, were studied on platelet function in vitro. LDL and lipoprotein(a) [Lp(a)] modified with secondary breakdown products of lipid peroxidation (4-hydroxy-2,3-
trans
-nonenal [HNE] 0.1 to 10 mmol/L or malondialdehyde [MDA] 1 to 50 mmol/L) induced neither spontaneous platelet aggregation nor secretion of 5-hydroxytryptamine (5-HT) from platelet amine-storage granules. Incubation of platelets with HNE- or MDA-modified LDL or Lp(a) (up to 1200 μg protein/mL) prior to thrombin (0.2 U/mL)– or collagen (2 μg/mL)–induced aggregation did not enhance platelet aggregability or formation of eicosanoids, ie, thromboxane A
2
or prostaglandins E
2
and F
2α
. In contrast to native lipoproteins, HNE- or MDA-modified LDL and Lp(a) (≈20% to 30% of total apolipoprotein lysine residues modified) exerted a pronounced dose-dependent inhibition of 5-HT release from activated platelets in the following order: HNE LDL (50%)>HNE Lp(a) (40%)>MDA LDL (20%)>MDA Lp(a) (5%). Preincubation of human blood platelets with acetylated LDL or Lp(a) (≈60% to 70% of total lysine residues modified) prior to aggregation impaired serotonin secretion by 50% compared with native LDL or Lp(a). These findings suggest that the interaction of platelets with aldehyde-modified atherogenic plasma lipoproteins should not necessarily be considered as proatherogenic with respect to the effects observed in our in vitro studies.
Thrombin Decreases the Urokinase Receptor and Surface-Localized Fibrinolysis in Cultured Endothelial Cells
Authors: Li Xin-Nong , Varma Vivek K. , Parks James M. , Benza Raymond L. , Koons Jay C. , Grammer J. Robert , Grenett Hernan , Tabengwa Edlue M. , Booyse Francois M.
Published: June 2011

AbstractThe endothelial cell (EC) urokinase receptor plays an important role in the localization and receptor-mediated activation of EC-bound plasminogen and hence surface-localized fibrinolysis. Thrombin induced a rapid (<5 minute), time- (0 to 30 minutes) and dose- (0.1 to 8 U/mL) dependent decrease in the specific binding of125I-labeled two-chain urokinase-type plasminogen activator (tcu-PA) or diisopropylfluorophosphate–tcu-PA to urokinase-type plasminogen activator receptor (u-PAR) in cultured ECs from various sources (range, 21% to 50%). The thrombin receptor activation peptide but not control peptide showed a similar but reduced decrease in the specific binding of125I-labeled tcu-PA to u-PAR. Incubation of thrombin-treated cultures (10 to 12 hours) in complete medium restored125I-labeled tcu-PA ligand binding to normal levels. u-PAR mRNA levels rapidly (1 hour) increased and peaked 10 to 12 hours after thrombin treatment as analyzed by reverse transcriptase–polymerase chain reaction. Decreased thrombin-induced125I-labeled tcu-PA binding correlated with the time-dependent decrease in surface-localized plasmin generation, as measured by the direct activation of125I-labeled Glu-plasminogen and quantification of the 20-kD light chains of125I-labeled plasmin. After incubation with thrombin, plasmin generation was decreased 50% to 56% (125 to 152 fmol/3 to 3.5×104cells). Isolation of metabolically labeled35S-labeled u-PAR from the media of thrombin and phospholipase C–treated human aortic cultures yielded ≈10- and ≈12-fold more 55-kDMrand ≈6-fold more 35-kDMr35S-labeled u-PAR forms than control cultures, respectively. The u-PAR antigen forms (Mr, 54 kD) and the glycosyl-phosphatidylinositol–anchored protein CD59 (Mr, 20 kD) were also simultaneously identified by immunoprecipitation in the media of thrombin-treated cultures. This suggests that thrombin may release u-PAR and decrease u-PA ligand binding through a common pathway involving phospholipase C. These results establish a novel interrelation between thrombin and EC fibrinolysis and suggest that thrombin may also have an additional regulatory role in the net expression of surface-localized EC fibrinolytic activity.
Characterization of Recombinant Human ApoB-48–Containing Lipoproteins in Rat Hepatoma McA-RH7777 Cells Transfected With ApoB-48 cDNA
Authors: Hussain M. Mahmood , Zhao Yang , Kancha Ravi K. , Blackhart Brian D. , Yao Zemin
Published: June 2011

Abstract
We studied the effect of overexpression of apolipoprotein (apo) B-48 on the synthesis and secretion of endogenous apoB-100 in rat hepatoma McA-RH7777 cell lines stably transfected with human apoB-48 cDNA under the control of the cytomegalovirus promoter. Three cell lines that secrete 40 to 60 ng human apoB · mg cell protein
−1
· h
−1
were used. The recombinant human apoB-48 exhibited physicochemical characteristics (buoyant density, 1.06 to 1.21 g/mL; β-electrophoretic mobility and diameters, 16 to 20 nm) indistinguishable from those of endogenous rat apoB-48. Overexpression of the recombinant human apoB-48 resulted in a 50% decrease in the secretion of endogenous apoB-100 but did not affect the secretion of apoE or apoA-I. Several possible mechanisms for the decreased secretion of apoB-100 were evaluated. First, recruitment of lipids into lipoproteins was shown to be unaffected since no major changes in the physicochemical properties of apoB-100–containing lipoproteins were observed. Second, the intracellular degradation of apoB-100 was not altered as the intracellular retention half-time and secretion efficiency remained unaffected by apoB-48 overexpression. Third, the posttranslational regulatory mechanisms for apoB-100 remained normal, as demonstrated by a twofold increase in apoB-100 secretion after supplementation with oleic acid. Unexpectedly, a 35% to 50% decrease in the steady-state synthesis of endogenous apoB-100 was observed in apoB-48–transfected cells compared with control cells. These data suggested that decreased secretion of apoB-100 was secondary to decreased synthesis. The decreased apoB-100 synthesis was not due to decreased steady-state levels of rat apoB-100 mRNA. These results suggest that overexpression of recombinant human apoB-48 may interfere with posttranscriptional events, possibly at the translation-translocation level, and decrease translational yield of apoB-100. These posttranscriptional events prior to the complete synthesis of the apoB-100 polypeptide can be important in the control of apoB-100 secretion.
Tissue Factor Pathway Inhibitor Activity in Human Plasma
Authors: Kokawa Toshinori , Abumiya Takeo , Kimura Takashi , Harada-Shiba Mariko , Koh Hideki , Tsushima Motoo , Yamamoto Akira , Kato Hisao
Published: June 2011

Abstract
Tissue factor pathway inhibitor (TFPI), a protease inhibitor that is present in free and lipoprotein-associated forms in plasma and that also occurs as an endothelial cell–associated form, can inhibit the initial reactions of the tissue factor–mediated coagulation pathway. Although a positive correlation between plasma TFPI activity and cholesterol concentration in human plasma has been demonstrated, levels of the various forms of TFPI, ie, the LDL/VLDL-associated form, the HDL-associated form, and the free form, have not yet been completely determined in hyperlipidemia. We therefore established a method for the measurement of each of these forms of TFPI in plasma by gel filtration of plasma in buffer containing 1 mol/L NaCl. The recovery of TFPI activity in the free form was markedly greater as assessed by the new method than the recovery reported when other methods have been used. We employed the new method to analyze TFPI activity in 19 hyperlipidemic patients and compared the results with those for normal control subjects. The level of LDL/VLDL-associated TFPI in hyperlipidemic patients was significantly increased compared with control subjects’ levels (0.383±0.112 versus 0.237±0.077 U/mL), whereas the level of the free form of TFPI in hyperlipidemic patients was significantly decreased (0.381±0.132 versus 0.495±0.106 U/mL), the former being positively correlated with cholesterol level, while the latter was negatively correlated. These results led us to speculate that the decrease in the free form of TFPI in hyperlipidemia was caused by an increase in LDL/VLDL and/or by the inhibition of TFPI synthesis in endothelial cells; such an inhibition may reflect a reduction in the antithrombotic function of vascular endothelial cells. Of note, the decrease in the free form of TFPI was more striking in patients receiving plasmapheresis treatment (0.271±0.089 U/mL); this decrease was due to the repeated removal of LDL/VLDL-associated TFPI and endothelial cell–associated TFPI.
Effects of Androgens on Coronary Artery Atherosclerosis and Atherosclerosis-Related Impairment of Vascular Responsiveness
Authors: Adams Michael R. , Williams J. Koudy , Kaplan Jay R.
Published: June 2011

Abstract
The factors responsible for the marked gender differences in risk of coronary heart disease and atherosclerosis severity remain largely undetermined. While some clinical and experimental evidence supports a protective effect of endogenous estrogen on the initiation and progression of atherosclerosis and incidence of coronary heart disease, much of the epidemiological data do not support this conclusion. The possibility that endogenous androgens may have adverse effects on atherosclerosis progression and coronary risk has received little attention. We investigated the effects of experimentally induced hyperandrogenism in female cynomolgus monkeys with diet-induced atherosclerosis. Animals were assigned randomly to one of four treatment groups: (1) untreated controls, (2) ovariectomized (sex hormone-deficient) controls, (3) treated with androstenedione and estrone (mild hyperandrogenism), or (4) treated with testosterone (male plasma androgen pattern). At necropsy, coronary atherosclerosis was approximately twice as extensive (
P
<.05) in testosterone-treated animals relative to untreated controls, while treatment with androstenedione and estrone had no effect on atherosclerosis extent. Coronary plaque size was positively correlated with lumen size in intact and ovariectomized controls; however, there was no evidence of a similar relation between animals in either androgen treatment group. The atherogenic effects of testosterone were independent of variations in plasma lipoprotein and nonlipoprotein risk variables. Although chronic hyperandrogenism had adverse effects on atherosclerosis progression, it reversed (
P
<.03) atherosclerosis-related impairment of endothelium-dependent vasodilator responses. We conclude that an experimentally induced male plasma androgen pattern results in exacerbation of diet-induced atherosclerosis and has potentially adverse effects on atherosclerosis-related arterial remodeling in female monkeys. The results indicate that testosterone may have a direct role in the increased rate of atherosclerosis progression and increased risk of coronary heart disease seen in men, relative to women, in most Western societies.
Transcriptional Regulation of Tissue Factor Expression in Human Endothelial Cells
Authors: Parry Graham C. N. , Mackman Nigel
Published: June 2011

AbstractTissue factor (TF) expression by endothelial cells is implicated in thrombotic episodes in patients with a variety of clinical disorders. In a baboon model of lethal sepsis, TF is expressed by endothelial cells in the splenic microvasculature. In vitro, endothelial cells are induced to express TF in response to tumor necrosis factor–α (TNF-α), interleukin-1β (IL-1β), and bacterial endotoxin (lipopolysaccharide [LPS]). Here, we identifiedcis-acting regulatory elements that control TF gene transcription in primary human endothelial cells. Functional studies showed that the TF promoter contained a 56-bp enhancer (−227 to −172 bp), which included two activator protein–1 (AP-1) sites and a κB-like site, that mediated induction by TNF-α, IL-1β, and LPS. Electrophoretic mobility shift assays demonstrated that endothelial cells contained constitutive AP-1 binding activity, whereas the κB-like site, 5′-CGGAGTTTCC-3′, bound an inducible nuclear complex composed of c-Rel–p65 heterodimers. Taken together, our data suggest that induction of TF gene transcription in endothelial cells is mediated by functional interactions between Fos-Jun and c-Rel–p65 heterodimers.
Suppressive Role of Endogenous Endothelial Monocyte Chemoattractant Protein–1 on Monocyte Transendothelial Migration In Vitro
Authors: Takahashi Masafumi , Masuyama Jun-Ichi , Ikeda Uichi , Kitagawa Sei-Ichi , Kasahara Tadashi , Saito Masaki , Kano Shogo , Shimada Kazuyuki
Published: June 2011

AbstractMonocyte chemoattractant protein–1 (MCP-1, or monocyte chemotactic and activating factor) is thought to play an important role in monocyte infiltration into tissue, but little is known about its effect on monocyte-endothelium interaction. We examined the effect of MCP-1 produced by cytokine-activated endothelial cells (ECs) on monocyte-endothelium adhesion and subsequent transendothelial migration by using a double-chamber vessel model. Unstimulated ECs showed no MCP-1 expression, but exposure to interleukin-1β (IL-1β, 25 U/mL) induced marked MCP-1 mRNA expression and protein synthesis. When placed in the lower compartment, recombinant human (rh) MCP-1 (100 ng/mL) produced a 1.9-fold and a 2.7-fold increase in adhesion and migration, respectively, compared with a corresponding 51% and 59% decrease when placed in the upper compartment. Migration of monocytes was dependent on a gradient of rh–MCP-1 from the apical to basilar side of the EC layer. Furthermore, a forward gradient of MCP-1 induced adherent cells to increase their subsequent migration, whereas a reverse gradient induced the cells to detach and completely inhibited their subsequent migration. Pretreatment with IL-1β for 4 and 24 hours produced a 20% and 63% increase in monocyte migration, respectively. In the presence of anti–MCP-1 antibody, the increase was further enhanced by 52% and 152%, respectively. These results suggest that endogenous endothelial MCP-1, when secreted by IL-1–stimulated ECs, suppresses monocyte migration in the presence of MCP-1 on the basilar side of the EC layer. This process may be useful for preventing excessive infiltration of monocytes from the circulating blood into atherogenic tissue during the early stages of atherogenesis.
Hemostatic, Metabolic, and Androgenic Risk Factors for Coronary Heart Disease in Physically Active and Less Active Postmenopausal Women
Authors: Stevenson Edith T. , Davy Kevin P. , Seals Douglas R.
Published: June 2011

Abstract
Physically active postmenopausal women have a lower incidence of coronary heart disease (CHD) than their more sedentary peers, but little information is available concerning the responsible mechanisms. The primary aim of this study was to test the hypothesis that physically active postmenopausal women demonstrate more favorable levels of hemostatic, metabolic, and androgenic CHD risk factors than less active control subjects. If so, a secondary aim was to determine which of the characteristics associated with a physically active lifestyle, ie, low body fat, a high-carbohydrate/low-fat diet, high maximal aerobic capacity (aerobic fitness), and high levels of physical activity, are most closely related to this lower risk profile. To address these aims, we compared CHD risk factors in physically very active women (n=14; age, 55±2 years) with those in healthy, nonobese sedentary control subjects (n=17; age, 56±1 years). Maximal aerobic capacity (fitness) was 83% higher (
P
<.001) in the physically active women. Concentrations of plasminogen activator inhibitor type 1 activity and tissue plasminogen activator antigen were lower (more favorable) (
P
<.005) in the physically active women versus control subjects, whereas plasma fibrinogen levels did not differ. The physically active women had lower (
P
<.01) fasting plasma insulin and glucose concentrations as well as smaller responses to an oral glucose challenge. Both total-body and abdominal fat levels were lower (
P
<.001) and lipid and lipoprotein profiles were generally more favorable (
P
<.05) in the physically active women. Plasma sex hormone–binding globulin concentrations were higher (
P
<.01) in the physically active women, indicating a lower androgenicity-related CHD risk. In addition, the physically active women consumed a diet that was higher (
P
<.002) in carbohydrates and lower (
P
<.02) in fat and protein. Stepwise multiple regressions indicated that although a portion of the observed variability in these CHD risk factors can be explained by physical activity levels per se, the associated differences in total body and abdominal fat, dietary composition, and aerobic fitness also contribute in a significant but selective manner. Thirty percent to 40% of each group were on hormone replacement therapy, but its effects appeared to be minimal. These results demonstrate that physically active postmenopausal women exhibit favorable levels of hemostatic, metabolic, and androgenic CHD risk factors, which could contribute to their lower incidence of CHD.
Reduction of LDL Cholesterol by 25% to 60% in Patients With Primary Hypercholesterolemia by Atorvastatin, a New HMG-CoA Reductase Inhibitor
Authors: Nawrocki James W. , Weiss Stuart R. , Davidson Michael H. , Sprecher Dennis L. , Schwartz Sherwyn L. , Lupien Paul-J. , Jones Peter H. , Haber Harry E. , Black Donald M.
Published: June 2011

Abstract
This 6-week, double-blind clinical trial evaluated lipid parameter responses to different dosages of atorvastatin in patients with primary hypercholesterolemia. Atorvastatin is a new 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor under development. After completing an 8-week placebo-baseline dietary phase, 81 patients were randomly assigned to receive either placebo or 2.5, 5, 10, 20, 40, or 80 mg atorvastatin once daily for 6 weeks. Plasma LDL cholesterol reductions from baseline were dose related, with 25% to 61% reduction from the minimum dose to the maximum dose of 80 mg atorvastatin once a day. Plasma total cholesterol and apo B reductions were also dose related. Previously, reductions in LDL cholesterol of the magnitude observed in this study have been seen only with combination drug therapy. In this study, atorvastatin was well tolerated by hyperlipidemic patients, had an acceptable safety profile, and provided greater reduction in cholesterol than other previously reported HMG-CoA reductase inhibitors.
Generation, Characterization, and Histochemical Application of Monoclonal Antibodies Selectively Recognizing Oxidatively Modified ApoB-Containing Serum Lipoproteins
Authors: Hammer Astrid , Kager Gerd , Dohr Gottfried , Rabl Hans , Ghassempur Irmgard , Jürgens Günther
Published: June 2011

Abstract
To investigate either the role oxidized LDL plays in atherosclerosis or structural changes on the surface of oxidized LDL, monoclonal antibodies (mAbs) are an important tool. After immunizing mice with Cu
2+
-oxidized LDL (oxLDL) and fusion of splenocytes, hybridoma supernatants were screened and cloned. Two mAbs, OB/04 and OB/09 (IgG and IgM), were further characterized. In solid-phase fluorescence immunoassays and Western blot analysis both mAbs reacted with oxLDL, LDL oxidized by a free radical–generating azo compound, or oxVLDL but not with native LDL, acetylated LDL, oxHDL
3
, azo-oxidized HDL
3
, or HDL
3
modified with malondialdehyde (MDA). In competitive immunoassays with LDL modified by oxidized fatty acid–derived aldehydes, mAb OB/09 strongly reacted with MDA-LDL or MDA-VLDL and LDL modified with 4-hydroxyhexenal followed by 4-hydroxynonenal but not with 4-hydroxyoctenal or hepta-2,4-dienal. mAb OB/04 had a weak affinity for LDL after modification with these aldehydes except for MDA-LDL. LDL modified with arachidonic acid oxidation products (AAOPs) was also recognized by this mAb. However, albumin modified either by the aldehydes applied or by AAOPs did not react with either mAb. Thus, the data indicate that each of the mAbs recognizes a different epitope that is expressed only on apoB-containing lipoproteins upon oxidative modification. An immunostaining with mAb OB/04 was obtained in areas rich in macrophages and in connective tissue of a human atherosclerotic lesion.