bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of Dietary Fish and n-3 Fatty Acid Intake With Hemostatic Factors in the Coronary Artery Risk Development in Young Adults (CARDIA) Study
Authors: Archer Sujata L. , Green David , Chamberlain Maryann , Dyer Alan R. , Liu Kiang
Published: June 2011

Abstract
—Hemostatic factors play an important role in the complications of ischemic heart and vessel disease. Dietary fats such as n-3 fatty acids have been shown to possibly influence hemostatic factors. However, most studies reporting an inverse association between cardiovascular disease and fish and n-3 fatty acid consumption used supplemental doses of fish oil or intakes exceeding the typical amount consumed by the US population. This report examined the associations of usual intakes of fish, linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid with fibrinogen, factor VII, factor VIII, and von Willebrand factor in the Coronary Artery Risk Development in Young Adults (CARDIA) Study. The analyses reported here included 1672 black and white men and women aged 24 to 42 years in 1992 to 1993. After adjustment for age, body mass index, diabetes, number of cigarettes smoked per day, race, and energy and alcohol consumption, no significant associations were observed between those who consumed no fish versus those who consumed the highest level of dietary fish with respect to fibrinogen, factor VIII, or von Willebrand factor for any race-sex group. Comparisons of tertile 1 versus tertile 3 for dietary linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid were also not significantly associated with fibrinogen, factor VII, factor VIII, or von Willebrand factor for any race-sex group. These data suggest that customary intakes of fish and n-3 fatty acids in populations that generally do not consume large amounts of these food items are not associated with these hemostatic factors.
Platelet GP IIIa Pl
A
and GP Ib Variable Number Tandem Repeat Polymorphisms and Markers of Platelet Activation in Acute Stroke
Authors: Carter A. M. , Catto A. J. , Bamford J. M. , Grant P. J.
Published: June 2011

Abstract
—A number of polymorphisms of the platelet glycoprotein (GP) Ib-V-IX and IIb/IIIa complexes have been described, and the Pl
A
polymorphism of GP IIIa has been associated with coronary thrombosis. We determined the levels of β-thromboglobulin (β-TG) and platelet factor 4 (PF4) and the genotype distributions of Pl
A
and a variable number tandem repeat (VNTR) polymorphism of GP 1b in subjects with acute stroke (n=609) and healthy control subjects (n=435). Levels of β-TG were higher in patients both initially (47.4 [44.7 to 50.2] ng/mL,
P
<0.0001) and after 3 months (42.9 [40.3 to 45.7] ng/mL,
P
=0.03) compared with control subjects (39.4 [37.7 to 41.2] ng/mL). Initial levels of β-TG were significantly higher in those who subsequently died (58.7 [52.3 to 65.8] ng/mL) compared with those still alive (42.7 [40.1 to 45.5] ng/mL,
P
<0.0001). In a logistic regression model, β-TG remained an independent predictor of poststroke mortality, with an odds ratio for an increase in 10 ng/mL of 1.12 (1.03 to 1.21,
P
=0.006). In subjects who had never smoked, there was a significant difference in the genotype distributions of patients with atherothrombotic stroke (
A1/A1
=147,
A1/A2
=70, and
A2/A2
=2) compared with controls (
A1/A1
=165,
A1/A2
=47, and
A2/A2
=5,
P
=0.03). The Pl
A
distribution of subjects with atherothrombotic stroke before the age of 50 years (
A1/A1
=19 and
A1/A2
+
A2/A2
=18) was also significantly different from age- and sex-matched controls (
A1/A1
=54 and
A1/A2
+
A2/A2
=20,
P
=0.02). We found no association of VNTR with stroke or poststroke mortality. These data indicate that there is a persistent state of enhanced platelet activation in subjects with acute stroke, which is associated with poststroke mortality. The increased frequency of the Pl
A2
allele in young subjects with atherothrombotic stroke lends further support for a role of the Pl
A
polymorphism in acute thrombosis.
Apoptosis in Restenosis Versus Stable-Angina Atherosclerosis
Authors: Bauriedel Gerhard , Schluckebier Sven , Hutter Randolph , Welsch Ulrich , Kandolf Reinhard , Lüderitz Berndt , Prescott Margaret Forney
Published: June 2011

Abstract
—Decreases in programmed cell death (apoptosis) may contribute to restenotic hyperplasia by prolonging the life span of intimal cells. Apoptotic events were compared in restenotic versus primary lesions, by using atherectomy samples from 16 restenotic and 30 primary human peripheral and coronary lesions from patients presenting with stable angina. We used transmission electron microscopy to identify apoptosis, quantify its frequency, distinguish apoptosis from necrosis, and relate these events to cellular composition. Smooth muscle cell (SMC) density was higher in restenotic versus primary lesions (
P
<0.0001), whereas the number of macrophages was significantly reduced (
P
<0.01) and the number of lymphocytes was lower, but not significantly (
P
=0.06). As the main finding, restenotic lesions contained fewer apoptotic cells compared with primary lesions (3% versus 13%,
P
=0.002), whereas no differences were found for cellular necrosis. With regard to cell type, the lower frequency of apoptotic cells observed in restenotic tissue was attributable to both SMCs and macrophages. The key finding of less apoptosis in restenotic versus primary lesions was in agreement with terminal deoxynucleotidyl transferase–mediated dUTP nick-end labeling (TUNEL) analysis (2% versus 9%,
P
<0.001). For all lesions analyzed, significant inverse correlations were observed between the density of SMCs and the frequency of apoptotic cell death (
r
=−0.60,
P
<0.001) as well as the density of SMCs and that of macrophages (
r
=−0.74,
P
<0.001). No relationship was seen between the frequency of apoptosis and the density of macrophages. In conclusion, the data of the present study indicate that a low level of apoptosis may be an important mechanism leading to restenotic intimal lesion development after interventional procedures.
Age-Related Deterioration in Arterial Structure and Function in Postmenopausal Women
Authors: McGrath Barry P. , Liang Yu-Lu , Teede Helena , Shiel Louise M. , Cameron James D. , Dart Anthony
Published: June 2011

Abstract
—Epidemiological evidence suggests that hormone replacement therapy (HRT) reduces morbidity and mortality from cardiovascular diseases in postmenopausal women. In this study, indices of arterial function [total systemic arterial compliance (SAC) and carotid arterial distensibility coefficient (DC)], structure [carotid intima-media thickness (IMT)], and lipid profiles were compared in postmenopausal women on long-term HRT and aged-matched controls. One hundred nine women aged 44 to 77 years taking HRT and an age-matched group of 108 female controls were entered into the study. The two groups were similar for body mass index, smoking status, exercise level, alcohol intake, and blood pressure. Fasting cholesterol, low density lipoprotein, and lipoprotein(a) were reduced and high density lipoprotein increased in the HRT group. IMT increased with age; SAC and DC were reduced with age in both groups. The HRT group had a higher mean SAC (0.42±0.02 versus 0.34±0.02 U/mm Hg,
P
=0.0001) and a lower mean IMT (0.67±0.01 versus 0.74±0.02 mm,
P
=0.006) than did controls. Subgroup analysis for estrogen versus estrogen plus progestin revealed no differences for SAC and IMT; DC, however, was greater in estrogen-only users. Smokers on HRT had a higher mean SAC (0.41±0.02 versus 0.31±0.01 U/mm Hg,
P
=0.008) and a lower IMT (0.65±0.02 versus 0.75±0.03 mm,
P
=0.002) than did smokers not taking such therapy. A protective effect of long-term estrogen therapy on age-related changes in arterial structure and function in postmenopausal women was evident in smokers and nonsmokers alike. Progestin appeared to counteract the effects of estrogen on carotid compliance only. Long-term controlled trials are needed to determine the significance of these findings.
Adenovirus-Mediated Gene Transfer of Macrophage Colony Stimulating Factor to the Arterial Wall In Vivo
Authors: Mozes Geza , Mohacsi Tibor , Gloviczki Peter , Menawat Sunil , Kullo Iftikhar , Spector David , Taylor John , Crotty Thomas B. , O’Brien Timothy
Published: June 2011

Abstract—Macrophage colony stimulating factor (MCSF) is believed to play a key role in one of the earliest events in atherosclerosis, ie, monocyte to macrophage differentiation in the arterial intima. The aim of this study was to examine the biological effects of vascular wall expression of MCSF. A recombinant adenovirus vector encoding human MCSF (AdMCSF) was generated by standard techniques of homologous recombination in 293 cells. The rabbit carotid artery was transduced with AdMCSF. As negative controls, carotid arteries were transduced with either an adenoviral vector encoding β-galactosidase, an adenoviral vector encoding apolipoprotein E, or diluent alone. Intima-media thickness ratio was calculated 5 and 21 days after transduction. The cell type present in intimal infiltrates was analyzed by immunohistochemistry. MCSF expression was demonstrated in the vessel wall of AdMCSF-transduced vessels by reverse transcription–polymerase chain reaction and immunofluorescence. In contrast to control vessels, adenovirus-mediated MCSF expression was associated with an intimal cellular infiltrate consisting of smooth muscle cells and small numbers of macrophages. Whereas the intima-media thickness ratio was greater in AdMCSF-transduced vessels at 5 days, this difference was no longer statistically significant at 21 days. These results suggest that MCSF may play a role in recruitment of monocytes and macrophages to the vessel wall and may contribute to smooth muscle cell proliferation and migration.
Endotoxin and Cytokines Increase Hepatic Sphingolipid Biosynthesis and Produce Lipoproteins Enriched in Ceramides and Sphingomyelin
Authors: Memon Riaz A. , Holleran Walter M. , Moser Arthur H. , Seki Taisuke , Uchida Yoshikazu , Fuller John , Shigenaga Judy K. , Grunfeld Carl , Feingold Kenneth R.
Published: June 2011

Abstract
—Alterations in triglyceride and cholesterol metabolism often accompany inflammatory diseases and infections. We studied the effects of endotoxin (lipopolysaccharide [LPS]) and cytokines on hepatic sphingolipid synthesis, activity of serine palmitoyltransferase (SPT), the first and rate-limiting enzyme in sphingolipid synthesis, and lipoprotein sphingolipid content in Syrian hamsters. Administration of LPS induced a 2-fold increase in hepatic SPT activity. The increase in activity first occurred at 16 hours, peaked at 24 hours, and was sustained for at least 48 hours. Low doses of LPS produced maximal increases in SPT activity, with half-maximal effect seen at ≈0.3 μg LPS/100 g body weight. LPS increased hepatic SPT mRNA levels 2-fold, suggesting that the increase in SPT activity was due to an increase in SPT mRNA. LPS treatment also produced 75% and 2.5-fold increases in hepatic sphingomyelin and ceramide synthesis, respectively. Many of the metabolic effects of LPS are mediated by cytokines. Interleukin 1 (IL-1), but not tumor necrosis factor, increased both SPT activity and mRNA levels in the liver of intact animals, whereas both IL-1 and tumor necrosis factor increased SPT mRNA levels in HepG2 cells. IL-1 produced a 3-fold increase in SPT mRNA in HepG2 cells, and the half-maximal dose was 2 ng/mL. IL-1 also increased the secretion of sphingolipids into the medium. Analysis of serum lipoprotein fractions demonstrated that very low density lipoprotein, intermediate density lipoprotein, and low density lipoprotein isolated from animals treated with LPS contained significantly higher amounts of ceramide, glucosylceramide, and sphingomyelin. Taken together, these results indicate that LPS and cytokines stimulate hepatic sphingolipid synthesis, which results in an altered structure of circulating lipoproteins and may promote atherogenesis.
G Protein Signaling and Vein Graft Intimal Hyperplasia
Authors: Davies Mark G. , Huynh Tam T. T. , Fulton Gregory J. , Lefkowitz Robert J. , Svendsen Einar , Hagen Per-Otto , Koch Walter J.
Published: June 2011

Abstract
—Vein grafting results in the development of intimal hyperplasia with accompanying changes in guanine nucleotide–binding (G) protein expression and function. Several serum mitogens that act through G protein–coupled receptors, such as lysophosphatidic acid, stimulate proliferative pathways that are dependent on the G protein βγ subunit (G
βγ
)–mediated activation of p21
ras
. This study examines the role of G
βγ
signaling in intimal hyperplasia by targeting a gene encoding a specific G
βγ
inhibitor in an experimental rabbit vein graft model. This inhibitor, the carboxyl terminus of the β-adrenergic receptor kinase (βARK
CT
), contains a G
βγ
-binding domain. Vein graft intimal hyperplasia was significantly reduced by 37% (
P
<0.01), and physiological studies demonstrated that the normal alterations in G protein coupling phenotypically seen in this model were blocked by βARK
CT
treatment. Thus, it appears that G
βγ
-mediated pathways play a major role in intimal hyperplasia and that targeting inhibitors of G
βγ
signaling offers novel intraoperative therapeutic modalities to inhibit the development of vein graft intimal hyperplasia and subsequent vein graft failure.
Endothelial NO Synthase Is Increased in Regenerating Endothelium After Denuding Injury of the Rat Aorta
Authors: Poppa Veronica , Miyashiro Jody K. , Corson Marshall A. , Berk Bradford C.
Published: June 2011

Abstract—Endothelial nitric oxide synthase (eNOS) has been shown to be regulated both transcriptionally and posttranslationally in cultured endothelial cells, but eNOS regulatory mechanisms in vivo have not been elucidated. Because one of the strongest stimuli for eNOS expression in tissue culture is cell proliferation and because increased NO production would be beneficial in the setting of arterial injury, we hypothesized that eNOS expression should be increased in regenerating endothelium after a denuding injury. Rat aortas underwent partial endothelial denudation by passage of a deflated balloon catheter, and eNOS expression was studied 48 hours after injury. Immunohistochemistry with eNOS monoclonal antibody, NADPH diaphorase activity assay under conditions specific for eNOS, and mRNA hybridization were performed in situ on perfusion-fixed rat aortic segments. The vessels were studied en face to enhance visualization compared with cross sections. eNOS protein and mRNA expression were significantly increased in regenerating and migrating endothelial cells at the wound edge, with translocation of eNOS to the plasma membrane at the leading edge. Similar results were obtained when endothelial cells were studied in a tissue culture wound model. An important role for transforming growth factor (TGF)-β1in regulating eNOS expression was suggested by the ability of a TGF-β1–neutralizing antibody to limit induction of eNOS at the wound edge. Increased eNOS expression after wounding appears to be related to signal events associated with cell migration as well as proliferation, because eNOS expression in vivo increased in nonproliferating cells and TGF-β1–neutralizing antibody inhibited eNOS expression but stimulated proliferation. The current study is the first to suggest an important role in vivo for increased eNOS, and perhaps NO production, in the process of endothelial regeneration and wound repair.
Administration of Abciximab During Percutaneous Coronary Intervention Reduces Both Ex Vivo Platelet Thrombus Formation and Fibrin Deposition
Authors: Dangas George , Badimon Juan J. , Coller Barry S. , Fallon John T. , Sharma Samin K. , Hayes Richard M. , Meraj Perwaiz , Ambrose John A. , Marmur Jonathan D.
Published: June 2011

Abstract
—Abciximab (c7E3 Fab, ReoPro), a platelet glycoprotein (GP) IIb/IIIa inhibitor, decreases acute ischemic complications after percutaneous coronary interventions. Recently, abciximab was shown to decrease thrombin generation in vitro in a static system. To assess whether abciximab can decrease fibrin formation in blood from patients, we quantified both platelet thrombi and fibrin deposition by using an ex vivo flow chamber model. We prospectively studied 18 consecutive patients who underwent percutaneous interventions for unstable coronary syndromes. Blood was perfused directly from the patient through an ex vivo perfusion chamber at a high shear rate, thus mimicking mildly stenosed coronary arteries. Perfusion chamber studies were performed when patients were being treated with heparin plus aspirin before the procedure (baseline) and then repeated after the procedure, when patients were on either aspirin plus heparin alone (group 1, no abciximab, control) or aspirin plus heparin plus abciximab (group 2, abciximab treated). Each patient served as his or her own control. Specimens were stained with combined Masson’s trichrome–elastin and antibodies specific for fibrinogen, fibrin, and platelet GP IIIa. Total thrombus area and areas occupied by platelet aggregates and fibrin layers were quantified by planimetry. Group 1 demonstrated no significant change in thrombus area before versus after the procedure; in contrast, treatment with abciximab reduced total thrombus area by 48% in group 2 (after the procedure versus baseline,
P
=0.01). This decline was due to significant reductions in both platelet aggregates (55%,
P
=0.005) and fibrin layers (45%,
P
=0.03). The addition of abciximab to heparin and aspirin in patients undergoing coronary interventions significantly decreases ex vivo thrombus formation on an injured vascular surface. Treatment with abciximab appears to reduce both the platelet and the fibrin thrombus components. This finding supports a potential role for GP IIb/IIIa receptor blockade in decreasing fibrin formation in addition to inhibition of platelet aggregation. Thus, potent inhibitors of GP IIb/IIIa may also act as anticoagulants.
Dietary Fish Oils Modify the Assembly of VLDL and Expression of the LDL Receptor in Rabbit Liver
Authors: Wilkinson Jane , Higgins Joan A. , Fitzsimmons Colin , Bowyer David E.
Published: June 2011

Abstract
—Supplementation of the diet of rabbits with fish oil or sunflower oil resulted in significant changes in the lipoproteins and lipids in serum. Compared with chow-fed rabbits, dietary fish oils decreased very low density lipoprotein (VLDL), increased low density lipoprotein (LDL), and shifted the peak of the LDL to denser fractions, whereas sunflower oil increased high density lipoprotein and shifted LDL to the lighter fractions. The amount of LDL receptors in fish oil–fed rabbit liver decreased by >70% while there was only a small fall in these levels in sunflower oil–fed rabbit liver. The concentrations of apolipoprotein (apo) B in the subcellular organelles of the secretory compartment (rough and smooth endoplasmic reticula and Golgi fractions) were also changed by dietary lipids. In both sunflower oil– and fish oil–fed liver, apo B was increased in the lumen of the rough endoplasmic reticulum compared with fractions from chow-fed rabbit liver. The apo B in the trans-Golgi lumen from fish oil–fed livers was reduced and occurred in particles of
d
≈1.21 g/mL. In contrast, apo B in the trans-Golgi lumen from livers of sunflower oil–fed rabbits was increased and occurred in particles of
d
<1.21 g/mL. These results suggests that feeding of fish oils causes an interruption in the intracellular transfer of apo B and hence assembly of VLDL. This leads to an enrichment of the rough endoplasmic reticulum membranes with cholesterol, thus downregulating the expression of the LDL receptor.
Developmental and Pharmacological Regulation of Apolipoprotein C-II Gene Expression
Authors: Andersson Yvonne , Majd Zouher , Lefebvre Anne-Marie , Martin Geneviève , Sechkin Alexander V. , Kosykh Vladimir , Fruchart Jean-Charles , Najib Jamila , Staels Bart
Published: June 2011

Abstract—Increased plasma triglyceride concentrations are often observed in metabolic disorders predisposing to coronary heart disease. Among the major determinants of plasma triglyceride metabolism are the apolipoproteins (apos) of the C class, C-I, C-II, and C-III. Whereas physiological concentrations of apo C-II are required for lipolysis of triglycerides by lipoprotein lipase (LPL), overexpression of all 3 C apolipoproteins leads to hypertriglyceridemia. In the present study, we investigated apo C-II gene regulation under conditions associated with profound changes in plasma triglyceride metabolism, ie, during postnatal development and after treatment with the triglyceride-lowering fibrate drugs, and compared its expression to that of apo C-I and apo C-III. Whereas the expression of both apo C-I and apo C-III is low in fetal liver, increases gradually after birth, and attains maximal levels after weaning, apo C-II gene expression is already detectable in the fetal liver, increases rapidly immediately after birth, and remains elevated throughout suckling. Thus, the increased ingestion of lipids during suckling is met by an earlier induction of apo C-II, the obligatory activator for LPL, compared with apo C-III and apo C-I, which antagonize triglyceride catabolism. Treatment of rats with fibrates decreased apo C-II gene expression in the liver, but not in the intestine, whereas apo C-I gene expression did not change. The decrease of liver apo C-II mRNA levels after fenofibrate occurred in a time- and dose-dependent manner and was reversible but appeared less pronounced than the decrease of apo C-III mRNA. Apo C-II mRNA levels were not affected after treatment withBRL49653, a peroxisome proliferator–activated receptor (PPAR)γ–specific ligand, suggesting that fibrates act on apo C-II expression via PPARα. Addition of fenofibric acid to primary rat and human hepatocytes resulted in a decrease of apo C-II expression. In conclusion, fibrates decrease gene expression of apo C-II and apo C-III, but not apo C-I, in rat and human hepatocytes. This decrease of apo C-II and apo C-III gene expression, together with a lowered apo C-III to apo C-II ratio, should result in an improved clearance of triglyceride-rich remnant lipoproteins from plasma, without hampering triglyceride lipolysis by LPL.
Ultrasound and Lipoproteins as Predictors of Lipid-Rich, Rupture-Prone Plaques in the Carotid Artery
Authors: Grønholdt Marie-Louise M.
Published: June 2011

Abstract
—The aim of this review is to summarize present knowledge of the ultrasonic detection and determinants of carotid atherosclerosis with lipid-rich cores and to review the evidence that these measures of plaque type may predict cerebral events. With the use of high-resolution ultrasound B-mode imaging, carotid plaques evaluated as only weakly reflecting the ultrasound beam (echolucent) have been associated with a higher risk of neurological events than are plaques reflecting the ultrasound signal strongly (echorich). Histologically, these echolucent plaques have a higher content of lipid and hemorrhage than do echorich plaques, which contain more calcification and fibrous tissue. Findings in the coronary arteries indicate that a lipid-rich plaque with a thin, fibrous cap is more vulnerable, is more prone to rupture, and cause symptoms compared with fibrous plaques. A search for determinants in the blood for these vulnerable plaques suggests that low density lipoprotein (LDL) cholesterol is the best lipid predictor for the extent of atherosclerosis, whereas triglyceride-rich lipoproteins in particular seem to predict an echolucent plaque. Lowering of LDL cholesterol and triglyceride-rich lipoproteins in plasma is associated with reduced progression of coronary atherosclerosis and coronary events. LDL cholesterol reduction is also associated with a reduced stroke rate. These improvements in the prognosis are thought to be the result of a reduction in the lipid content of the plaques, making them more stable and resistant to rupture rather than an actual reduction in plaque volume and degree of stenosis. In conclusion, it appears that ultrasound B-mode imaging as well as lipoproteins presumably may predict dangerous and rupture-prone, lipid-rich plaques in the carotid arteries, thereby being potential diagnostic tools in the prevention of neurological events.
Two Patterns of Lipid Deposition in the Cholesterol-Fed Rabbit
Authors: Barnes Sally E. , Weinberg Peter D.
Published: June 2011

Abstract
—A central feature of arterial lipid deposition is its nonuniform and variable distribution. In immature human and rabbit aortas, spontaneous lesions occur most frequently downstream of branch points, but they tend to occur upstream of the same branches at later ages. In cholesterol-fed rabbits, the juvenile pattern has been seen regardless of age. These distributions may be determined by transport properties of the arterial wall, because uptake of plasma macromolecules is elevated downstream of aortic branches in immature rabbits and upstream in mature ones, except during cholesterol feeding, when the juvenile pattern is seen in adult vessels. The effect of cholesterol could reflect its inhibitory influence on the nitric oxide (NO) pathway because the adult transport pattern is NO dependent. Using protocols expected to preserve NO function and the mature pattern of transport during hypercholesterolemia, we made 2 attempts to induce upstream disease in rabbits. In trial I, plasma concentrations of cholesterol were kept within the normal human range for 15 weeks by using dietary levels of 0.05% to 0.2%. Although disease patterns reverse with age in human vessels exposed to these concentrations, lesions in both immature and mature rabbits occurred downstream of intercostal branch ostia. Trial II used older rabbits, a different base diet containing more vitamin E (96 mg/kg rather than 57 mg/kg), and higher levels of cholesterol (1%, administered for 8 weeks). For some animals, extra vitamin E (2000 mg/kg) was added to the diet. The mature pattern of lipid deposition was apparent around intercostal branches in the first group and was accentuated by the additional vitamin E, a change that was associated with a significant increase in the plasma concentration of NO metabolites. Spontaneous lesions, assessed on the base diet, were too rare to have influenced these distributions. This is the first report of upstream disease in the cholesterol-fed rabbit. The results support but do not prove the view that NO and transport are important in atherogenesis.
Impaired Endothelium-Dependent Vascular Responses of Retinal and Intrarenal Arteries in Patients With Type 2 Diabetes
Authors: Kawagishi Takahiko , Matsuyoshi Miyoko , Emoto Masanori , Taniwaki Hiromichi , Kanda Hiroyuki , Okuno Yasuhisa , Inaba Masaaki , Ishimura Eiji , Nishizawa Yoshiki , Morii Hirotoshi
Published: June 2011

Abstract
—Endothelial dysfunction has been implicated in the pathogenesis of diabetic microangiopathies such as retinopathy and nephropathy as well as macrovascular diseases. The aim of the current study was to determine whether endothelial function in the retinal and renal arteries is impaired in type 2 diabetes mellitus. We examined the effects of an intravenous infusion of
l
-arginine and a sublingual administration of nitroglycerin on the brachial, retinal, and interlobar arterial hemodynamics in 20 type 2 diabetic patients (10 with normoalbuminuria and 10 with microalbuminuria) and 10 aged-matched control subjects. Despite no difference in the nitroglycerin-induced vascular response of the brachial or retinal artery among the 3 groups, the
l
-arginine–induced vascular response of each artery was significantly lower in both the normoalbuminuric and microalbuminuric patients than in the control subjects and the microalbuminuric patients showed the lowest value among the 3 groups (
P
<0.01, each artery, respectively). The
l
-arginine–induced vascular response of each artery was significantly correlated with HbA1c levels (brachial artery,
r
=0.617,
P
=0.0003; retinal artery,
r
=0.599,
P
=0.0005; interlobar artery,
r
=0.636,
P
=0.0002). In addition, stepwise multiple regression analysis of all subjects showed that HbA1c level was an independent determinant for the
l
-arginine–induced vascular response of each artery. The results showed that the endothelium-dependent vascular responses of the retinal and intrarenal arteries as well as the brachial artery were impaired in diabetic patients before the clinical manifestation of diabetic nephropathy, and suggest that endothelial dysfunction in these arteries is associated with hyperglycemia in these patients.
Intimal Deposition of Functional von Willebrand Factor in Atherogenesis
Authors: De Meyer Guido R. Y. , Hoylaerts Marc F. , Kockx Mark M. , Yamamoto Hiroshi , Herman Arnold G. , Bult Hidde
Published: June 2011

Abstract
—During the formation of intimal thickening in normocholesterolemic rabbits, von Willebrand factor (vWF) is increased in the endothelial cells (ECs) and deposited in the intima. We investigated whether this also occurs during cholesterol-induced plaque formation, whether the synthesis of vWF increases, and whether this influences platelet adhesion. Rabbits were fed a cholesterol-rich (0.3%) diet for 26 weeks. Thereafter, half of the animals received a normal diet for another 26 weeks (cholesterol withdrawal). To induce intimal thickening in normocholesterolemic rabbits, collars were positioned around the carotid artery. Arterial segments were studied using immunohistochemistry, reverse transcription–polymerase chain reaction, electron microscopy, and platelet adhesion tests. Cholesterol treatment induced plaque formation in the aorta. The ECs had a cuboidal aspect, showed a dense immunoreactivity for vWF, a pronounced rough endoplasmic reticulum, and numerous Weibel-Palade bodies. There were subendothelial vWF deposits in the plaques and vWF mRNA was significantly increased as compared with controls. Similar changes were seen after collar-induced intimal thickening. After cholesterol withdrawal, both vWF mRNA and the ultrastructural morphology of the ECs normalized, and the vWF deposits disappeared from the plaque. Perfusion studies with anticoagulated rabbit blood over cross-sections of atherosclerotic aortas revealed increased vWF-mediated platelet adhesion in the subendothelial plaque region. Whereas rabbit platelets perfused through the lumen adhered to the same extent to de-endothelialized aortas of normocholesterolemic and atherosclerotic rabbits, vWF mediated platelet adhesion to endothelium was observed in atherosclerotic but not in normal aortas. Our results show an increased synthesis and (sub)endothelial presence of vWF after vascular injury, with functional consequences for platelet deposition on the vessel wall.
Lipoxygenase Products Increase Monocyte Adhesion to Human Aortic Endothelial Cells
Authors: Patricia Mary Kim , Kim Jeong A. , Harper Cynthia M. , Shih Peggy T. , Berliner Judith A. , Natarajan Rama , Nadler Jerry L. , Hedrick Catherine C.
Published: June 2011

Abstract
—The development of atherosclerosis is accelerated in individuals with type 2 diabetes. Adhesion of monocytes to the vascular endothelium is a key initial step in atherogenesis. We have previously shown that monocyte adhesion to human aortic endothelial cells (HAECs) cultured long-term in high-glucose medium (25 mmol/L, 2 passages) is increased compared with cells grown in normal glucose (5 mmol/L). One potential mechanism for increased monocyte adhesion to HAECs under hyperglycemic conditions is via the 12-lipoxygenase (12-LO) pathway. In this study, we demonstrated in HAECs that the major LO metabolite of arachidonic acid was the 12-LO product, 12(
S
)-hydroxyeicosatetraenoic acid [12(
S
)-HETE], which was increased severalfold in HAECs cultured under high-glucose conditions. Furthermore, treatment of HAECs with 12(
S
)-HETE induced monocyte, but not neutrophil, adhesion an average of 3-fold (range of 1.5- to 5-fold) compared with untreated cells (75±5 versus 26±1 monocytes per field, respectively,
P
<0.001). Expression of the adhesion molecules vascular cell adhesion molecule-1, E-selectin, and intercellular adhesion molecule-1 was not significantly increased. However, both glucose and 12(
S
)-HETE induced a 60% increase in HAEC surface expression of connecting segment-1 (ie, CS-1) fibronectin, a ligand for very late–acting antigen-4 (VLA-4). The antibodies used to block monocyte integrin VLA-4 and leukocyte function–related antigen-1, a monocytic counterreceptor for intercellular adhesion molecule-1, inhibited the ability of both 12-LO products and high glucose to induce monocyte adhesion. These results definitively demonstrate for the first time in HAECs that the 12-LO pathway can induce monocyte–endothelial cell interaction and that the effects of glucose may be mediated, at least in part, through this pathway. Thus, these results suggest that the 12-LO pathway may play a role in the increased susceptibility of diabetics to atherosclerosis.
Focal Expression of Angiotensin II Type 1 Receptor and Smooth Muscle Cell Proliferation in the Neointima of Experimental Vein Grafts
Authors: Liu S. Q.
Published: June 2011

Abstract
—Eddy flow has been shown to promote focal smooth muscle cell (SMC) proliferation and neointimal formation in experimental vein grafts. This study focuses on whether the angiotensin II type 1 (AT
1
) receptor mediates these events. Experimental vein grafts with and without eddy flow were created in the rat. Losartan was used to assess the influence of the AT
1
receptor on SMC proliferation. In vein grafts with eddy flow, apparent focal expression of AT
1
mRNA and protein was found in the leading region of the proximal focal neointima, where eddy flow occurred, but not in the trailing region, where eddy flow diminished, at days 5, 10, 20, and 30. The rate of SMC proliferation in the leading region (10.9±1.4%, 19.5±2.2%, 12.2±2.0%, and 6.9±1.3% at these times, respectively) was significantly higher than that in the trailing region (9.5±1.8%, 15.3±2.0%, 8.2±1.9%, and 3.2±0.7%) in these vein grafts. When eddy flow was prevented in engineered vein grafts, no apparent location difference was found in the distribution of AT
1
receptor mRNA and protein in the neointima, and the rate of SMC proliferation (5.3±1.0%, 5.8±0.9%, 3.4±1.0%, and 3.7±0.9% at days 5, 10, 20, and 30, respectively) was reduced significantly. In vein grafts with losartan, the rate of SMC proliferation in the leading region of the neointima (9.4±1.8%, 10.1±1.3%, 8.3±0.9%, and 4.2±0.5% at days 5, 10, 20, and 30, respectively) was significantly lower than that in vein grafts without losartan. These results suggested that eddy flow upregulated the AT
1
receptor, which in turn mediated focal SMC proliferation in the neointima of experimental vein grafts.
Sphingomyelinase, an Enzyme Implicated in Atherogenesis, Is Present in Atherosclerotic Lesions and Binds to Specific Components of the Subendothelial Extracellular Matrix
Authors: Marathe Sudhir , Kuriakose George , Williams Kevin Jon , Tabas Ira
Published: June 2011

Abstract
—Atherosclerotic lesions contain an extracellular sphingomyelinase (SMase) activity that hydrolyzes the sphingomyelin of subendothelial low density lipoprotein (LDL). This SMase activity may promote atherosclerosis by enhancing subendothelial LDL retention and aggregation, foam cell formation, and possibly other atherogenic processes. The results of recent cell-culture studies have led to the hypothesis that a specific molecule called secretory SMase (S-SMase) is responsible for the SMase activity known to be in lesions, although its presence in atheromata had not been examined directly. Herein we provide immunohistochemical and biochemical support for this hypothesis. First, 2 different antibodies against S-SMase detected extracellular immunoreactive protein in the intima of mouse, rabbit, and human atherosclerotic lesions. Much of this material in lesions appeared in association with the subendothelial matrix. Second, binding studies in vitro demonstrated that
125
I-S-SMase adheres to the extracellular matrix of cultured aortic smooth muscle and endothelial cells, specifically to the laminin and collagen components. Third, in its bound state, S-SMase retains substantial enzymatic activity against lipoprotein substrates. Overall, these data support the hypothesis that S-SMase is an extracellular arterial wall SMase that contributes to the hydrolysis of the sphingomyelin of subendothelial LDL. S-SMase may therefore be an important participant in atherogenesis through local enzymatic effects that stimulate subendothelial retention and aggregation of atherogenic lipoproteins.
Platelet-Derived Growth Factor Stimulates Heme Oxygenase-1 Gene Expression and Carbon Monoxide Production in Vascular Smooth Muscle Cells
Authors: Durante William , Peyton Kelly J. , Schafer Andrew I.
Published: June 2011

Abstract
—Recent studies indicate that vascular smooth muscle cells (VSMCs) generate CO from the degradation of heme by the enzyme heme oxygenase-1 (HO-1). Because platelet-derived growth factor (PDGF) modulates various responses of VSMCs, we examined whether this peptide regulates the expression of HO-1 and the production of CO by rat aortic SMCs. Treatment of SMCs with PDGF resulted in a time- and concentration-dependent increase in the levels of HO-1 mRNA and protein. Both actinomycin D and cycloheximide blocked PDGF-stimulated HO-1 mRNA and protein. In addition, PDGF stimulated the production of reactive oxygen species by SMCs. Both the PDGF-mediated generation of reactive oxygen species and the induction of HO-1 protein was inhibited by the antioxidant
N
-acetyl-
l
-cysteine. Incubation of platelets with PDGF-treated SMCs resulted in a significant increase in platelet cGMP concentration that was reversed by treatment of SMCs with the HO-1 inhibitor tin protoporphyrin-IX or by addition of the CO scavenger hemoglobin to platelets. In contrast, the nitric oxide inhibitor methyl-
l
-arginine did not block the stimulatory effect of PDGF-treated SMCs on platelet cGMP. Finally, incubation of SMCs with the releasate from collagen-activated platelets induced HO-1 protein expression that was blocked by a neutralizing antibody to PDGF. These results demonstrate that either administered exogenously or released by platelets, PDGF stimulates HO-1 gene expression and CO synthesis in vascular smooth muscle. The ability of PDGF to induce HO-1–catalyzed CO release by VSMCs may represent a novel mechanism by which this growth factor regulates vascular cell and platelet function.
3-Deazaadenosine Prevents Adhesion Molecule Expression and Atherosclerotic Lesion Formation in the Aortas of C57BL/6J Mice
Authors: Walker Gerhard , Langheinrich Alexander C. , Dennhauser Elisabeth , Bohle Rainer M. , Dreyer Thomas , Kreuzer Jörg , Tillmanns Harald , Braun-Dullaeus Ruediger C. , Haberbosch Werner
Published: June 2011

Abstract—Adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) play an important role during the development of atherosclerosis. 3-Deazaadenosine (c3Ado), an adenosine analogue, inhibits endothelial-leukocyte adhesion and ICAM-1-expression in vitro. We hypothesized that c3Ado is able to prevent the expression of adhesion molecules and atherosclerotic lesion formation in female C57BL/6J mice. The animals were placed on an atherogenic diet with or without c3Ado for 9 weeks. Frozen cross sections of the proximal ascending aorta just beyond the aortic sinus were stained with oil red O, hematoxylin, and elastic van Gieson’s stains and were analyzed by computer-aided planimetry for fatty plaque formation and neointimal proliferation. Monoclonal antibodies against CD11b (macrophages), VCAM-1, and ICAM-1 were used for immunohistochemistry. Mice on the atherogenic diet demonstrated multiple (5.4±1.6 per animal) lesions covering 3.4±2.8% of the endothelium and a marked neointima when compared with control mice (4501±775 versus 160±38 μm2,P<0.001). Mice on the cholesterol-rich diet without c3Ado showed strong endothelial coexpression of ICAM-1 and VCAM-1. Moreover, there was a 10-fold increase in monocyte accumulation on the endothelial surface (33.3±4.9 versus 3.8±1.2,P<0.004). In contrast, in mice treated with c3Ado, expression of ICAM-1 and VCAM-1 as well as monocyte adhesion and infiltration were almost completely inhibited. Furthermore, these mice did not show any fatty streak formation or neointima formation (125±32 μm2). Our results demonstrate that c3Ado can inhibit diet-induced fatty streak formation and the expression of endothelial ICAM-1 and VCAM-1 in C57BL/6J mice. This may provide a novel pharmacological approach in the prevention and treatment of atherosclerosis.
A Frequent Mutation in the Lipoprotein Lipase Gene (D9N) Deteriorates the Biochemical and Clinical Phenotype of Familial Hypercholesterolemia
Authors: Wittekoek Marianne E. , Moll Etelka , Pimstone Simon N. , Trip Mieke D. , Lansberg Peter J. , Defesche Joep C. , van Doormaal Jasper J. , Hayden Michael R. , Kastelein John J. P.
Published: June 2011

Abstract
—The D9N substitution is a common mutation in the lipoprotein lipase (LPL) gene. This mutation has been associated with reduced levels of HDL cholesterol and elevated triglycerides (TG) in a wide variety of patients. We investigated the influence of this D9N mutation on lipid and lipoprotein levels and risk for cardiovascular disease (CVD) in patients with familial hypercholesterolemia (FH). A total of 2091 FH heterozygotes, all of Dutch extraction, were screened for the D9N mutation using standard polymerase chain reaction techniques, followed by specific enzyme digestion. A total of 94 FH subjects carrried the D9N mutation at a carrier frequency of 4.5%. Carriers of other common LPL mutations, such as the N291S and the S447X were excluded. Clinical data on 80 FH individuals carrying the D9N were available and were compared with a FH control group matched for age, sex, and body mass index (n=203). Analysis revealed significantly higher TG (
P
=0.01) and lower HDL-cholesterol levels (
P
=0.002). Dyslipidemia was more pronounced in D9N carriers with higher body mass index. Moreover, FH patients carrying this common LPL mutation were at higher risk for CVD, (odds ratio=2.8; 95% CI, 1.43 to 5.32;
P
=0.002). The common D9N LPL mutation leads to increased TG and decreased HDL plasma levels in patients with FH. These effects are most apparent in those FH heterozygotes with an increased body mass index. Furthermore, this mutation, present in 4.5% of Dutch FH heterozygotes, leads to increased risk for CVD.
The Diagnostic Accuracy of Ex Vivo MRI for Human Atherosclerotic Plaque Characterization
Authors: Shinnar Meir , Fallon John T. , Wehrli Suzanne , Levin Michael , Dalmacy Dolcine , Fayad Zahi A. , Badimon Juan J. , Harrington Martin , Harrington Elizabeth , Fuster Valentin
Published: June 2011

Abstract
—Recent evidence indicates that the type of atherosclerotic plaque, rather than the degree of obstruction to flow, is an important determinant of the risk of cardiovascular complications. In previous work, the feasibility of using MRI for the characterization of plaque components was shown. This study extends the previous work to all the plaque components and shows the accuracy of this method. Twenty-two human carotid endarterectomy specimens underwent ex vivo MRI and histopathological examination. Sixty-six cross sections were matched between MRI and histopathology. In each cross section, the presence or absence of plaque components were prospectively identified on the MRI images. The overall sensitivity and specificity for each tissue component were very high. Calcification and fibrocellular tissue were readily identified. Lipid core was also identifiable. However, thrombus was the plaque component for which MRI had the lowest sensitivity. A semiautomated algorithm was created to identify all major atherosclerotic plaque components. MRI can characterize carotid artery plaques with a high level of sensitivity and specificity. Application of these results in the clinical setting may be feasible in the near future.
In the Femoral Artery Bifurcation, Differences in Mean Wall Shear Stress Within Subjects Are Associated With Different Intima-Media Thicknesses
Authors: Kornet Lilian , Hoeks Arnold P. G. , Lambregts Jacques , Reneman Robert S.
Published: June 2011

Abstract
—In elastic arteries, intima-media thickening is more pronounced in areas with low than with high mean and peak wall shear stress. These findings in elastic arteries are not necessarily representative of the situation in muscular arteries. The former arteries have to store volume energy, whereas the latter are mainly conductive vessels. It was the aim of the present study to investigate noninvasively whether differences in wall shear stress within a muscular artery bifurcation, if any, were associated with different intima-media thicknesses (IMTs). The effect of age on the possible differences was assessed as well. We determined IMT and mean, peak systolic, and the maximum cyclic change in shear stress near the posterior wall in the common (FC) and the superficial (FS) femoral artery 20 to 30 mm from the flow divider in 54 presumed healthy subjects between 21 and 74 years of age. Results were considered in terms of intrasubject differences. Before the study, the reliability of the ultrasonic system to assess wall shear rate and IMT was determined in terms of intrasubject variability. IMT at the posterior wall was significantly larger in the FC than in the FS, probably owing to the significantly lower mean wall shear stress at this site in the FC. The relative differences in IMT and mean wall shear stress between FC and FS were independent of age. The difference in wall shear stress between both arteries can likely be explained by a different influence of reflections. In both the FC and FS, mean, peak systolic, and maximum cyclic change in shear stress near the posterior wall did not change significantly with age, whereas IMT did increase significantly with age.
Human Apolipoprotein (Apo) B-48 and ApoB-100 Kinetics With Stable Isotopes
Authors: Welty Francine K. , Lichtenstein Alice H. , Barrett P. Hugh R. , Dolnikowski Gregory G. , Schaefer Ernst J.
Published: June 2011

Abstract
—The kinetics of apolipoprotein (apo) B-100 and apoB-48 within triglyceride-rich lipoproteins (TRLs) and of apoB-100 within IDL and LDL were examined with a primed-constant infusion of (5,5,5-
2
H
3
) leucine in the fed state (hourly feeding) in 19 subjects after consumption of an average American diet (36% fat). Lipoproteins were isolated by ultracentrifugation and apolipoproteins by SDS gels, and isotope enrichment was assessed by gas chromatography/mass spectrometry. Kinetic parameters were calculated by multicompartmental modeling of the data with SAAM II. The pool sizes (PS) of TRL apoB-48, VLDL apoB-100, and LDL apoB-100 were 17±10, 273±167, and 3325±1146 mg, respectively. There was a trend toward a faster fractional catabolic rate (FCR) for VLDL apoB-100 than for TRL apoB-48 (6.73±3.48 versus 5.02±2.07 pools/d, respectively,
P
=0.06). The mean FCRs for IDL and LDL apoB-100 were 10.07±7.28 and 0.27±0.08 pools/d, respectively. The mean production rate (PR) of TRL apoB-48 was 6.5% of VLDL apoB-100 (1.3±0.90 versus 20.06±6.53 mg · kg
−1
· d
−1
,
P
<0.0001). TRL apoB-48 PS was correlated with apoB-48 PR (
r
=0.780,
P
<0.0001) but not FCR (
r
=−0.1810,
P
=0.458). VLDL apoB-100 PS was correlated with both PR (
r
=0.713,
P
=0.0006) and FCR (
r
=−0.692,
P
=0.001) of VLDL apoB-100 and by apoB-48 PR (
r
=0.728,
P
=0.0004). LDL apoB-100 PS was correlated with FCR (
r
=−0.549,
P
=0.015). These data indicate that (1) the FCRs of TRL apoB-48 and VLDL apoB-100 are similar in the fed state, (2) TRL apoB-48 PS is correlated with TRL apoB-48 PR, (3) VLDL apoB-100 PS is correlated with both PR and FCR of VLDL apoB-100 and PR of TRL apoB-48, and (4) LDL apoB-100 PS is correlated with LDL FCR.