bluuebunny/crossref_metadata_2025 huggingface dataset:
Neovascular Expression of E-Selectin, Intercellular Adhesion Molecule-1, and Vascular Cell Adhesion Molecule-1 in Human Atherosclerosis and Their Relation to Intimal Leukocyte Content
Authors: O’Brien Kevin D. , McDonald Thomas O. , Chait Alan , Allen Margaret D. , Alpers Charles E.
Published: June 2012

Background
Leukocyte recruitment is an early event in atherogenesis, and the leukocyte adhesion molecules E-selectin, intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) recently have been detected in human atherosclerosis. However, no previous study has evaluated either the distribution of these three molecules at different sites within the arterial intima or their relation to plaque leukocyte content.

Methods and Results
Immunohistochemistry was performed on 99 coronary artery segments (34 controls and 65 with atherosclerotic plaque) to identify E-selectin, ICAM-1, VCAM-1, macrophages, smooth muscle cells, and T lymphocytes. For each segment, the presence or absence of adhesion molecule was determined at the arterial lumen, on intimal neovasculature, and on intimal nonendothelial cells. Each segment was scored for intimal macrophage and T-lymphocyte densities on a semiquantitative scale of 0 to 3. In atherosclerotic plaques, the prevalences of E-selectin, ICAM-1, and VCAM-1 on plaque neovasculature were twofold higher than their prevalences on arterial luminal endothelium. E-selectin was the only adhesion molecule for which expression on arterial luminal endothelial cells was more prevalent in plaques than in control segments. Increased plaque intimal macrophage density was associated with expression of VCAM-1 on neovasculature (
P
<.01) and on nonendothelial cells (
P
<.01). Increased plaque intimal T-lymphocyte density was associated with the presence of both ICAM-1 and VCAM-1 on neovasculature (both
P
<.01) and on nonendothelial cells (both
P
<.01).

Conclusions
In atherosclerotic plaques, the expression of all three leukocyte adhesion molecules was more prevalent on intimal neovasculature than on arterial luminal endothelium. Further, the presence on neovasculature and nonendothelial cells of VCAM-1 and ICAM-1 was strongly associated with increased intimal leukocyte accumulation. These findings suggest that leukocyte recruitment through and/or activation of intimal neovasculature may play important roles in the pathogenesis of human atherosclerosis.
Absence of Focal Compensatory Enlargement or Constriction in Diseased Human Coronary Saphenous Vein Bypass Grafts
Authors: Nishioka Toshihiko , Luo Huai , Berglund Hans , Eigler Neal L. , Kim Chong-Jin , Tabak Steven W. , Siegel Robert J.
Published: June 2012

Background
No in vivo data are available on the occurrence of compensatory enlargement or vessel constriction in diseased human coronary saphenous vein bypass grafts (SVBGs). The aim of this intravascular ultrasound (IVUS) study was to examine to what extent lumen reduction is accompanied by (1) vessel wall thickening and (2) arterial wall constriction in SVBGs.

Methods and Results
We used IVUS to examine 43 SVBGs from 42 patients (32 men, 10 women; mean age, 72±5 years) 8 to 23 (11±4) years after SVBG. IVUS images were obtained with a 3.5F monorail ultrasound catheter with a 30-MHz frequency and were analyzed at the lesion site, the reference site, and an intermediate site. The lumen area was significantly (
P
<.01) decreased; the vessel wall area (SVBG cross-sectional area minus lumen area) and the plaque area (area within the external elastic lamina minus lumen area) were significantly (
P
<.01) increased from the reference site through the lesion site. However, SVBG cross-sectional area was the same at these three sites (24.0±8.1 versus 24.4±8.6 versus 24.5±8.6 mm
2
,
P
=NS), and the external elastic lamina area was also quite constant in each vessel (17.8±6.0 versus 17.7±6.4 versus 17.6±6.2 mm
2
,
P
=NS).

Conclusions
These in vivo IVUS data from human coronary SVBGs demonstrate that (1) no focal compensatory enlargement or vessel constriction occurred in stenotic segments compared with the reference segments and that (2) the absence of focal compensatory enlargement appears to be a potentially important factor in the progression of stenoses in coronary SVBGs.
Secular Trends in Long-term Sustained Hypertension, Long-term Treatment, and Cardiovascular Mortality
Authors: Sytkowski Pamela A. , D’Agostino Ralph B. , Belanger Albert J. , Kannel William B.
Published: June 2012

Background
Cardiovascular morbidity and mortality result from the chronic processes involved in hypertension. However, long-term sustained (LTS) hypertension has received little attention.

Methods and Results
Trends in the prevalence of LTS hypertension and its treatment were assessed in 1950, 1960, and 1970 among three cohorts of men and women in the Framingham Heart Study (Mantel-Haenszel test). Cardiovascular disease (CVD) incidence and mortality were compared between patients with LTS hypertension with and without long-term treatment by use of the χ
2
test. Cox proportional hazards regression analysis was used to estimate 10-year risk of death as a function of risk factor levels and treatment. Prevalence of LTS hypertension rose from 138 to 208 per 1000 between the 1950 and 1970 male cohorts (
P
<.01), while prevalence fell from 253 to 198 per 1000 between the female cohorts (
P
<.02). Long-term treatment increased 51% between the male cohorts and 45% between the female cohorts (both
P
<.001). While CVD incidence was similar (26% versus 25%), all-cause mortality was significantly lower among men with long-term treatment (31% versus 43%;
P
<.05), and CVD mortality was less than half (13% versus 28%;
P
<.01). Among treated women, all-cause mortality was 21% (versus 34%;
P
<.01), and CVD mortality was 9% (versus 19%;
P
<.01). Ten-year risk of CVD death for patients with LTS hypertension with long-term treatment compared with those without was 0.40 (95% CI, 0.27 to 0.60).

Conclusions
This investigation of LTS hypertension, its treatment, and its sequelae in a free-living general population confirms the reduction in CVD mortality demonstrated in more short-term clinical trials of hypertension therapy in select patient groups.
Induction of Nitric Oxide Synthase in the Human Cardiac Allograft Is Associated With Contractile Dysfunction of the Left Ventricle
Authors: Lewis Neil P. , Tsao Philip S. , Rickenbacher Peter R. , Xue Chun , Johns Roger A. , Haywood Guy A. , von der Leyen Heiko , Trindade Pedro T. , Cooke John P. , Hunt Sharon A. , Billingham Margaret E. , Valantine Hannah A. , Fowler Michael B.
Published: June 2012

Background
The mechanisms underlying cardiac contractile dysfunction after transplantation remain poorly defined. Previous work has revealed that inducible nitric oxide synthase (iNOS) is expressed in the rat heterotopic cardiac allograft during rejection; resultant overproduction of nitric oxide (NO) might cause cardiac contractile dysfunction via the negative inotropic and cytotoxic actions of NO. In this investigation, we tested the hypothesis that induction of iNOS may occur and be associated with cardiac allograft contractile dysfunction in humans.

Methods and Results
We prospectively studied 16 patients in the first year after cardiac transplantation at the time of serial surveillance endomyocardial biopsy. Clinical data, the results of biopsy histology, and echocardiographic and Doppler evaluation of left ventricular systolic and diastolic function were recorded. Total RNA was extracted from biopsy specimens, and mRNA for β-actin, detected by reverse transcription–polymerase chain reaction (RT-PCR) using human specific primers, was used as a constitutive gene control; iNOS mRNA was similarly detected by RT-PCR using human specific primers. iNOS protein was detected in biopsy frozen sections by immunofluorescence. Myocardial cGMP was measured by radioimmunoassay, and serum nitrogen oxide levels (NO
x
=NO
2
+NO
3
) were measured by chemiluminescence. iNOS mRNA was detected in allograft myocardium at some point in each patient and in 59 of 123 biopsies (48%) overall. In individual patients, iNOS mRNA expression was episodic and time dependent; the frequency of expression was highest during the first 180 days after transplant (
P
=.0006). iNOS protein associated with iNOS mRNA was detected by immunofluorescence in cardiac myocytes. iNOS mRNA expression was not related to the ISHLT histological grade of rejection or to serum levels of NO
x
but was associated with increased levels of myocardial cGMP (
P
=.01) and with both systolic (
P
=.024) and diastolic (
P
=.006) left ventricular contractile dysfunction measured by echocardiography and Doppler.

Conclusions
These data support a relation between iNOS mRNA expression and contractile dysfunction in the human cardiac allograft.
Pathophysiology of Chronic Left Ventricular Dysfunction
Authors: Marinho Norma V.S. , Keogh Bruce E. , Costa Durval C. , Lammerstma Adriaan A. , Ell Peter J. , Camici Paolo G.
Published: June 2012

Background
Chronically dysfunctional myocardium may improve after coronary revascularization. This condition was thought to be due to a chronically reduced myocardial blood flow (MBF). Recently, however, it has been shown that in patients without previous infarction but with chronic left ventricular dysfunction, baseline MBF was normal.

Methods and Results
To study the pathophysiology of chronic left ventricular dysfunction in patients with previous infarction, regional MBF (milliliter per minute per gram of water-perfusable tissue) and glucose utilization (MRG; micromoles per minute per gram) during hyperinsulinemic euglycemic clamp were measured with positron emission tomography in 30 patients before bypass. At baseline, 133 myocardial segments were normal, and 107 were dysfunctional. After revascularization, 59 of 107 segments improved, while 48 of 107 were unchanged. MBF was 0.92±0.25 mL · min
−1
· g
−1
in normal segments, 0.87±0.31 mL · min
−1
· g
−1
in improved segments (
P
=NS versus normal), and 0.82±0.40 mL · min
−1
· g
−1
in unchanged segments (
P
<.05 versus normal). In 90% of the dysfunctional segments, MBF was >0.42 mL · min
−1
· g
−1
, a cutoff value corresponding to the mean MBF minus 2 SD in normal segments. The MRG was 0.71±0.14 μmol · min
−1
· g
−1
in 9 age-matched normal subjects, 0.45±0.19 μmol · min
−1
· g
−1
(
P
<.01) in normal segments, 0.44±0.14 μmol · min
−1
· g
−1
in improved segments (
P
=NS versus normal), and 0.34±0.17 μmol · min
−1
· g
−1
in unchanged segments (
P
<.01 versus normal and improved).

Conclusions
The results suggest that resting MBF measured with
15
O-labeled water in chronically dysfunctional segments is not reduced and that the myocardium of these patients is less sensitive to insulin than that of normal subjects.
Heparin and Heparan Sulfate Block Angiotensin IIInduced Hypertrophy in Cultured Neonatal Rat Cardiomyocytes
Authors: Akimoto Hajime , Ito Hiroshi , Tanaka Masato , Adachi Susumu , Hata Mimi , Lin Meihong , Fujisaki Hiroyuki , Marumo Fumiaki , Hiroe Michiaki
Published: June 2012

Background
Heparan sulfate, one of the primary components of extracellular matrix, is a potent antigrowth factor in certain types of cells. To elucidate a possible role of endogenous heparin-like molecules in regulating cardiomyocyte hypertrophy, we investigated the effects of heparin and heparan sulfate on angiotensin (Ang) II–induced hypertrophy in cultured neonatal rat cardiomyocytes.

Methods and Results
Competitive [
3
H]heparin binding assay showed that cardiomyocytes had specific binding sites for heparin. In situ [
3
H]heparin binding assay demonstrated that heparin, which rapidly bound to the cardiomyocyte surface, was subsequently accumulated around the nuclei, suggesting that heparin might work in the nucleus. Cotreatment with heparin (20 μg/mL) completely inhibited increased cell surface area by Ang II (10
−6
mol/L). Increased [
3
H]leucine incorporation by Ang II was reduced by heparin dose-dependently. The inhibitory effect of heparin on Ang II–induced cardiomyocyte hypertrophy also was confirmed by Northern blot analysis: heparin dose-dependently inhibited skeletal α-actin and atrial natriuretic peptide gene expression, genetic markers for cardiomyocyte hypertrophy. Heparan sulfate showed similar inhibitory effects on cell surface area, [
3
H]leucine incorporation, and skeletal α-actin gene expression. Treatment with heparinase I or III, which specifically digests the disaccharide chains of endogenous heparin-like molecules, upregulated protein synthesis and skeletal α-actin and atrial natriuretic peptide gene expression in cardiomyocytes.

Conclusions
Our findings in this study strongly suggest that heparin and heparan sulfate are potent inhibitors of cardiomyocyte hypertrophy and that endogenous heparin-like substances negatively regulate cardiomyocyte hypertrophy.
Exercise Myocardial Perfusion SPECT in Patients Without Known Coronary Artery Disease
Authors: Hachamovitch Rory , Berman Daniel S. , Kiat Hosen , Cohen Ishac , Cabico J. Arthur , Friedman John , Diamond George A.
Published: June 2012

Background
We evaluated the incremental prognostic value, the role in risk stratification, and the impact on patient management of myocardial perfusion single-photon emission computed tomography (SPECT) in a population of patients without prior myocardial infarction, catheterization, or revascularization.

Methods and Results
We examined 2200 consecutive patients who at the time of their dual-isotope SPECT had not undergone catheterization, coronary artery bypass surgery, or percutaneous transluminal coronary angioplasty and had no known history of previous myocardial infarction. Follow-up was performed at a mean of 566±142 days (97% complete) for hard events (cardiac death and myocardial infarction) and for referral to cardiac catheterization or revascularization within 60 days after nuclear testing. Examination of clinical, exercise, and nuclear models by use of pre–exercise tolerance test (ETT), post-ETT, and nuclear information using a stepwise Cox proportional hazards model and receiver-operating characteristic curve analysis revealed that nuclear testing added incremental prognostic value after inclusion of the most predictive clinical and exercise variables (global χ
2
=12 for clinical variables; 31 for clinical+exercise variables; 169 for nuclear variables; gain in χ
2
,
P
<.0001 for all; receiver-operating characteristic areas: 0.66±0.04 for clinical, 0.73±0.04 for clinical+ exercise variables, 0.87±0.03 for nuclear variables,
P
=.03 for gain in area with exercise variables;
P
<.001 for increase with nuclear variables). Multiple logistic regression analysis revealed that scan information contributed 95% of the information regarding referral to catheterization with further additional information provided by presenting symptoms and exercise-induced ischemia. Referral rates to early catheterization and revascularization paralleled the hard event rates in all scan categories−very low referral rates in patients with normal scans and significant increases in referral rates as a function of worsening scan results. Even after stratification by clinical and exercise variables such as the Duke treadmill score, pre- and post-ETT likelihood of coronary artery disease, presenting symptoms, sex, and age, the nuclear scan results further risk-stratified the patient subgroups, thus demonstrating clinical incremental value.

Conclusions
In a patient population with no evidence of previous coronary artery disease at overall low risk (1.8% hard event rate), myocardial perfusion SPECT adds incremental prognostic information and risk-stratifies patients even after clinical and exercise information is known. It appears that referring physicians use this test in an appropriate manner in selecting patients to be referred to catheterization or revascularization.
Heart Transplantation–Associated Perioperative Ischemic Myocardial Injury
Authors: Fyfe Billie , Loh Evan , Winters Gayle L. , Couper Gregory S. , Kartashov Alex I. , Schoen Frederick J.
Published: June 2012

Background
The frequency and clinical significance of perioperative ischemic myocardial injury (PIMI) after heart transplantation and the diagnostic features distinguishing PIMI from rejection are not well defined.

Methods and Results
We evaluated PIMI in the first four weekly endomyocardial biopsies and/or autopsy myocardium from 140 consecutive orthotopic heart transplantation recipients (1984 to 1991) by grading the severity of coagulative myocyte necrosis (CMN) as absent, 0; mild-focal, 1; moderate-multifocal, 2; or severe-confluent, 3, and determining the evolution of morphological features of its healing. CMN (often with contraction bands) was noted in 124 patients (89%); 24 patients (17%) had grade 3 CMN, of which 4 died within 30 days of transplantation. Nevertheless, at 1 year after surgery, survival was similar in patients with and without severe injury. Increased cold ischemic time but neither donor age nor intensity of inotropic support correlated with more severe early ischemic injury. PIMI inflammation was characterized by a predominantly polymorphonuclear/histiocytic infiltrate that contained lymphocytes and plasma cells, expanding the interstitium but not encroaching upon and separable from adjacent viable myocytes. Histological features of PIMI developed and resolved more slowly than those of typical myocardial infarct necrosis in nonimmunosuppressed patients; at 4 weeks, CMN persisted in 20% of patients and residual healing in nearly half. Diagnostic rejection was observed concurrently with PIMI in 54 of 533 biopsies (10%).

Conclusions
Diagnosed by conventional histological criteria, PIMI is prevalent early after heart transplantation and has a protracted healing phase that can mimic or coexist with rejection. Extensive PIMI has deleterious impact on short-term survival, but the long-term impact of PIMI remains to be established.
Sex Differences in Cardiac Arrest Survivors
Authors: Albert Christine M. , McGovern Brian A. , Newell John B. , Ruskin Jeremy N.
Published: June 2012

Background
Important sex differences in the epidemiology of sudden death and in the results of electrophysiological testing in survivors of cardiac arrest have been identified. These differences are currently poorly understood.

Methods and Results
Three hundred fifty-five consecutive survivors of out-of-hospital cardiac arrest (84 women and 271 men) referred for electrophysiologically guided therapy were analyzed retrospectively for sex differences in underlying pathology and predictors of outcome. Women were significantly less likely to have underlying coronary artery disease than men (45% versus 80%) and more likely to have other forms of heart disease or structurally normal hearts (
P
<.0001). The mean left ventricular ejection fraction was higher in women (0.46±0.18 versus 0.41±0.18,
P
<.05), and women were more likely to have no inducible arrhythmia at baseline electrophysiological testing (46% versus 27%,
P
=.002), although when the patients were stratified by coronary artery disease status, these sex differences were no longer present. The independent predictors of outcome differed between men and women. In men, a left ventricular ejection fraction of <0.40 was the most powerful independent predictor of total (relative risk, 2.8; 95% CI, 1.6 to 5.0;
P
<.0001) and cardiac (relative risk, 6.3; 95% CI, 2.9 to 13.5;
P
<.0001) mortality. In contrast, the presence of coronary artery disease was the only independent predictor of total (relative risk, 4.5; 95% CI, 1.5 to 13.4;
P
=.003) and cardiac (relative risk, 4.4; 95% CI, 1.2 to 15.6;
P
=.012) mortality in women.

Conclusions
Female survivors of cardiac arrest are less likely to have underlying coronary artery disease. The predictors of total and cardiac mortality differ between male and female survivors. Coronary artery disease status is the most important predictor in women, and impaired left ventricular function is the most important predictor in men.
Human Monocyte–Endothelial Cell Interaction Induces Synthesis of Granulocyte-Macrophage Colony-Stimulating Factor
Authors: Takahashi Masafumi , Kitagawa Seiichi , Masuyama Jun-Ichi , Ikeda Uichi , Kasahara Tadashi , Takahashi Yu-Ichi , Furukawa Yusuke , Kano Shogo , Shimada Kazuyuki
Published: June 2012

Background
Adhesion of monocytes to the endothelium is an initial step in the early stages of atherosclerosis and inflammation. Granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulates a range of functional activities of monocytes, including regulation of monocyte adhesion and induction of cytokine production. We investigated in this study whether GM-CSF synthesis was induced by the direct cell-to-cell interaction between human monocytes and human umbilical vein endothelial cells (ECs).

Methods and Results
The expressions of GM-CSF mRNA and protein were analyzed by Northern blotting and ELISA, respectively. Coculture of monocytes and ECs induced the high levels of GM-CSF mRNA expression, whereas culture of ECs or monocytes alone or coculture of neutrophils with ECs induced no GM-CSF mRNA expression. A large amount of GM-CSF was secreted into the supernatant upon coculture of monocytes with ECs. The supernatant from the coculture markedly stimulated O
2
−
release in neutrophils, and this effect was significantly inhibited by anti–GM-CSF antibody (Ab). Immunohistochemistry and in situ hybridization revealed that GM-CSF protein and mRNA were clearly detectable in both ECs and monocytes adhered to ECs but not in nonadherent monocytes. The GM-CSF production by the coculture was markedly inhibited by genistein and partially inhibited by Abs against interleukin-1 and tumor necrosis factor-α.

Conclusions
The present results indicate that GM-CSF is produced by direct interaction between monocytes and ECs and suggest that GM-CSF produced locally by monocyte-EC adhesive interaction plays an important role in the pathogenesis of atherosclerosis and inflammation by modulating monocyte/macrophage functions in vivo.
Common DNA Polymorphisms at the Lipoprotein Lipase Gene
Authors: Wang X.L. , McCredie R.M. , Wilcken D.E.L.
Published: June 2012

Background
DNA variants of the lipoprotein lipase gene are associated with changes in lipid metabolism similar to those in diabetes and may relate to the development of atherosclerotic lesions, particularly premature lesions.

Methods and Results
To determine whether lipoprotein lipase gene variants are relevant to ongoing atherogenesis, we explored relationships between two common lipoprotein lipase gene polymorphic markers,
Pvu
II at intron 6 and
Hin
dIII at intron 8; the severity of coronary artery disease (CAD); and lipid variables in 475 white patients 65 years of age or younger. We assessed CAD severity as the number of significantly stenosed (>50% luminal obstruction) major coronary arteries at angiography and by the Green Lane coronary score. We found a significant association between the
Pvu
II polymorphism and the number of significantly diseased vessels (
P
=.0099) and coronary score (
P
=.028), with the
Pvu
II(−) alleles associated with less severe disease. The
Hin
dIII polymorphism was not associated with severity but had an additive effect with the
Pvu
II polymorphism. There was a close relationship between the
Pvu
II(+/+) genotype and the presence of diabetes (
P
=.0025), with an OR of 3.12 (95% CI, 1.30 to 7.49) compared with the
Pvu
II(−/−) genotype. The interaction between these polymorphisms and CAD severity (rather than occurrence) was independent of the levels of triglycerides and HDL cholesterol and of other lipid variables. There was also a dosage-dependent relationship between the
Pvu
II polymorphism and levels of triglyceride. The
Pvu
II(−) allele was associated with low levels and variances of triglycerides.

Conclusions
We conclude that the lipoprotein lipase
Pvu
II polymorphism is significantly associated with CAD severity and with type II diabetes in CAD patients, independent of changes in circulating lipid levels. These findings may be relevant to mechanisms mediating atherogenesis.
Isolated Peripheral Pulmonary Artery Stenoses in the Adult
Authors: Kreutzer Jacqueline , Landzberg Michael J. , Preminger Tamar J. , Mandell Valerie S. , Treves S. Ted , Reid Lynne M. , Lock James E.
Published: June 2012

Background
Isolated peripheral pulmonary artery stenosis (PPS) in the adult is rare and frequently unsuspected. We review in this article our experience with 12 adult patients with isolated PPS, half of whom had been previously diagnosed with chronic pulmonary thromboembolic disease.

Methods and Results
The presentation, evolution, and management of 12 adults with isolated PPS, 17 to 51 years of age (mean, 36.2±9.7 years), were evaluated. Presenting symptoms were dyspnea and fatigue. Three patients had New York Heart Association (NYHA) functional class III or greater. Lung perfusion scans revealed multiple segmental abnormalities in flow distribution in all patients. Oxygen desaturation at rest was present in 4 patients. At catheterization, right ventricular (RV) pressure was suprasystemic in 2 patients, systemic in 1, and more than half-systemic in 7. All had multiple bilateral nonuniform stenoses in segmental and subsegmental arteries. Balloon pulmonary angioplasty (BPA) to decrease RV hypertension and improve pulmonary flow distribution was performed in 11 patients. After BPA, vessel diameter increased >50% in 10 patients, distal pulmonary artery pressure increased ≥30% in 6, and RV pressure decreased >30% in 5. One patient died shortly after BPA as a result of pulmonary hemorrhage. Immediate procedural success was achieved in 9 of 11 patients. At a mean follow-up period of 52±32 months, 7 patients had sustained symptomatic improvement (NYHA class I-II).

Conclusions
We describe a severe syndrome of isolated PPS in the adult that mimics chronic pulmonary thromboembolic disease. Pulmonary hemodynamics and angiography are required for definitive diagnosis. BPA may offer these patients successful short-term reduction in RV hypertension and alleviation of symptomatology.
Increased Adhesiveness of Isolated Monocytes to Endothelium Is Prevented by Vitamin C Intake in Smokers
Authors: Weber Christian , Erl Wolfgang , Weber Kim , Weber Peter C.
Published: June 2012

Background
To explore pathophysiological mechanisms of cigarette smoking involved in atherogenesis, we compared adhesiveness of isolated blood monocytes with endothelium and plasma levels of the aqueous phase antioxidant vitamin C in nonsmokers and smokers before and after supplementation, using a novel monocyte adhesion assay with fixed human endothelial cells.

Methods and Results
Monocyte adhesion to unstimulated human umbilical vein endothelial cells ranged from 0.17% to 0.51% in the nonsmoker group (0.37±0.09%, mean±SD, n=13). In smokers with a 1 to 2 packs per day consumption, monocyte adhesion was increased to 0.71±0.17% (mean±SD, n=10,
P
<.001), ranging from 0.46% to 0.99%. Increased adhesiveness was mediated by the integrin CD11b/CD18, as shown by inhibition with a monoclonal antibody to CD11b but not associated with altered CD11b surface expression. Plasma vitamin C levels were reduced in smokers (48.2±14.1 μmol/L) versus nonsmokers (67.7±17.6 μmol/L;
P
<.025), while no significant differences were found in retinol, vitamin E, or β-carotene levels. This confirms that the radical scavenger vitamin C reacts sensitively to oxidative stress induced by cigarette smoke in human plasma. Consistently, dietary supplementation with vitamin C (2 g per day) for 10 days raised plasma levels to 82.6±11.0 μmol/L (n=10,
P
<.001) in smokers and decreased monocyte adhesion to values found in nonsmokers (0.38±0.18%,
P
<.001). In contrast, vitamin C intake did not affect monocyte adhesiveness in nonsmokers (0.37±0.14%, n=6) despite increasing plasma levels to 82.9±11.8 μmol/L.

Conclusions
Our data show that cigarette smoking increases CD11b-dependent monocyte adhesiveness in humans. Restoring reduced plasma vitamin C concentrations in smokers by oral supplementation decreased monocyte adhesion to values found in nonsmokers.
Effect of Supplementary Antioxidant Vitamin Intake on Carotid Arterial Wall Intima-Media Thickness in a Controlled Clinical Trial of Cholesterol Lowering
Authors: Azen Stanley P. , Qian Dajun , Mack Wendy J. , Sevanian Alex , Selzer Robert H. , Liu Chao-Ran , Liu Ci-Hua , Hodis Howard N.
Published: June 2012

Background
There is accumulating experimental, epidemiological, and clinical evidence of an association between antioxidant vitamin intake and reduced risk of coronary heart disease. Using data from the Cholesterol Lowering Atherosclerosis Study (CLAS), we explored the association of self-selected supplementary antioxidant vitamin intake on the rate of progression of early preintrusive atherosclerosis.

Methods and Results
CLAS was an arterial imaging trial in which nonsmoking 40- to 59-year-old men with previous coronary artery bypass graft surgery were randomized to colestipol/niacin plus diet or placebo plus diet. The rate of progression of early preintrusive atherosclerosis was determined in 146 subjects using high-resolution B-mode ultrasound quantification of the distal common carotid artery far wall intima-media thickness (IMT). From the nutritional supplement database, 22 subjects had an on-trial average supplementary vitamin E intake of ≥100 IU per day (high users) and 29 subjects had an average on-trial supplementary vitamin C intake of ≥250 mg per day (high users). Within the placebo group, less carotid IMT progression was found for high supplementary vitamin E users when compared with low vitamin E users (0.008 versus 0.023 mm/y,
P
=.03). No effect of vitamin E within the drug group was found. No effect of vitamin C within the drug or placebo group was found.

Conclusions
Supplementary vitamin E intake appears to be effective in reducing the progression of atherosclerosis in subjects not treated with lipid-lowering drugs while the process is still confined to the arterial wall (early preintrusive atherosclerosis).
Methylenetetrahydrofolate Reductase Polymorphism, Plasma Folate, Homocysteine, and Risk of Myocardial Infarction in US Physicians
Authors: Ma Jing , Stampfer Meir J. , Hennekens Charles H. , Frosst Phyllis , Selhub Jacob , Horsford Jonathan , Malinow M. Rene , Willett Walter C. , Rozen Rima
Published: June 2012

Background
Hyperhomocysteinemia appears to be an independent risk factor for coronary disease. Elevated levels of plasma total homocysteine (tHCY) can result from genetic or nutrient-related disturbances in the transsulfuration or remethylation pathways for homocysteine metabolism. The enzyme 5,10-methylenetetrahydrofolate reductase (MTHFR) catalyzes the reduction of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, the predominant circulatory form of folate, which serves as a methyl donor for remethylation of homocysteine to methionine. A common mutation in MTHFR recently has been identified.

Methods and Results
We assessed the polymorphism in MTHFR, plasma tHCY, and folate using baseline blood levels among 293 Physicians' Health Study participants who developed myocardial infarction (MI) during up to 8 years of follow-up and 290 control subjects. The frequency of the three genotypes was (−/−) (homozygous normal), 47%; (+/−) (heterozygous), 41%; and (+/+) (homozygous mutant), 12%, with a similar distribution among both MI case patients and control subjects. Compared with those with genotype (−/−), the relative risk (RR) of MI among those with (+/−) was 1.1 (95% CI, 0.8 to 1.5), and it was 0.8 (0.5 to 1.4) for the (+/+) genotype; none of these RRs were statistically significant. However, those with genotype (+/+) had an increased mean tHCY level (mean±SEM, 12.6±0.5 nmol/mL), compared with those with genotype (−/−) (10.6±0.3) (
P
<.01). This difference was most marked among men with low folate levels (the lowest quartile distribution of the control subjects): those with genotype (+/+) had tHCY levels of 16.0±1.1 nmol/mL, compared with 12.3±0.6 nmol/mL (
P
<.001) for genotype (−/−).

Conclusions
In this population, MTHFR polymorphism was associated with higher homocysteine levels but not with risk of MI. A gene-environment interaction might increase the risk by elevating tHCY, especially when folate intake is low.
Prolonged Impairment of Regional Contractile Function After Resolution of Exercise-Induced Angina
Authors: Ambrosio Giuseppe , Betocchi Sandro , Pace Leonardo , Losi Maria Angela , Perrone-Filardi Pasquale , Soricelli Andrea , Piscione Federico , Taube Jean , Squame Fiorenzo , Salvatore Marco , Weiss James L. , Chiariello Massimo
Published: June 2012

Background
Delayed recovery of contractile function in spite of normal perfusion (ie, “stunning”) has been described in animal models of exercise-induced myocardial ischemia. Therefore, we investigated whether stunning may result from effort angina in patients.

Methods and Results
Patients with coronary artery disease underwent exercise testing combined with quantitative measurements of contractile function for up to 240 minutes after exercise determined by either measurement of regional ejection fraction (
99m
Tc radionuclide angiography; n=17, group A) or computer-assisted measurement of systolic wall thickening (n=14, group B). In the latter group, myocardial perfusion was also evaluated by
99m
Tc-sestamibi tomographic imaging. Angina induced marked contractile dysfunction. Hemodynamic and ECG changes brought about by ischemia were promptly normalized. Furthermore, no perfusion defects could be detected in group B patients 30 minutes after exercise, yet contractile function remained impaired well after cessation of exercise. Thirty minutes into recovery, regional ejection fraction of previously ischemic areas was still 82.6±4.6% of baseline in group A (
P
<.05). Similarly, in group B patients, systolic thickening of previously ischemic segments was still significantly impaired 60 minutes after exercise, averaging 33.8±2.8% versus 40.5±2.7% at baseline (
P
<.05). Contractile impairment was fully reversible, as the functioning of previously ischemic segments normalized between 60 and 120 minutes of recovery.

Conclusions
Prolonged yet ultimately reversible impairment of regional myocardial function may occur in patients after exercise-induced angina in the absence of perfusion abnormalities. These findings indicate that myocardial stunning may ensue after effort angina in patients with severe coronary artery disease.
Coupling of Hemodynamic Measurements With Oxygen Consumption During Exercise Does Not Improve Risk Stratification in Patients With Heart Failure
Authors: Mancini Donna , Katz Stuart , Donchez Lisa , Aaronson Keith
Published: June 2012

Background
Measurement of peak V̇
o
2
has become an accepted method to select patients for cardiac transplantation. Some investigators have suggested that the addition of exercise hemodynamic measurements can further enhance risk stratification because these measurements may identify patients with a noncardiac limitation to exercise.

Methods and Results
Accordingly, we performed maximal bicycle exercise with respiratory gas analysis and hemodynamic measurements in 65 patients (47 men, 18 women) 53±10 years old (mean±SD) who underwent a transplant evaluation at Columbia Presbyterian Medical Center. Skeletal muscle oxygenation of the vastus lateralis during exercise was assessed with near-infrared spectroscopy. Exercise hemodynamic, ventilatory, and muscle oxygenation measurements were obtained in all patients. For each subject, a linear correlation was derived between V̇
o
2
and pulmonary artery saturation (PA Sa
o
2
). The slope of this relationship and a theoretical V̇
o
2max
at a PA Sa
o
2
of 0% (V̇
o
2
intercept) was derived. Baseline measurements were left ventricular ejection fraction, 22±9%; pulmonary capillary wedge pressure (PCWP), 16±10 mm Hg; cardiac index (CI), 2.1±0.5 L·min
−1
·m
−2
; and PA Sa
o
2
, 53±8%. The cardiac output response to exercise was categorized as normal or abnormal by comparison to the linear equation of peak V̇
o
2
versus peak cardiac output as described by Higginbotham. Exercise measurements were peak V̇
o
2
, 12.1±3.0 mL·kg
−1
·min
−1
; V̇
o
2
intercept, 19.1±5.5 mL·kg
−1
·min
−1
; PCWP, 31±11 mm Hg; CI, 3.8±1.3 L·min
−1
·m
−2
; and PA Sa
o
2
, 27±9%. Only 6% of patients exhibited a normal cardiac output response to exercise. Multivariate analysis was performed with peak V̇
o
2
, V̇
o
2
intercept, skeletal muscle oxygenation at end exercise, and peak exercise hemodynamic variables. Only left ventricular stroke work and left ventricular stroke work index were shown to be predictive of survival.

Conclusions
Addition of exercise hemodynamic measurements to noninvasive metabolic stress testing minimally improves risk prognostication in patients with severe heart failure.
Single-Beat Estimation of End-Systolic Pressure-Volume Relation in Humans
Authors: Senzaki Hideaki , Chen Chen-Huan , Kass David A.
Published: June 2012

Background
The end-systolic pressure-volume relation (ESPVR) provides a useful measure of contractile function. However, the need to acquire multiple cardiac cycles at varying loads limits its applicability. We therefore developed and tested a novel single-beat estimation method that is based on normalized human time-varying elastance curves [E
N
(t
N
)].

Methods and Results
Pressure-volume (PV) data were measured by conductance catheter in 87 patients with normal or myopathic hearts. Time-varying elastance curves were generated from 72 PV loops (52 patients) and normalized both by amplitude and time to peak amplitude. The resulting E
N
(t
N
) curves were remarkably consistent despite variations in underlying cardiac disease, contractility, loading, and heart rate, with minimal interloop variance during the first 25% to 35% of contraction. On the basis of this finding and assuming ESPVR linearity and constant volume-intercept, ESPVRs were estimated from one beat with the use of PV data measured at normalized time (t
N
) and end systole (t
max
) to predict intercept: V
o(SB)
=[E
N
(t
N
)×P(t
max
)×V(t
N
)−P(t
N
)×V(t
max
)]/[E
N
(t
N
)×P(t
max
)−P(t
N
)] and slope E
max(SB)
=P
es
/[V
es
−V
o(SB)
]. Single-beat estimates were highly correlated with measured ESPVR values obtained by standard multiple-beat analysis (including data from 35 additional patients). E
max(SB)
accurately reflected acute inotropic change and was influenced little by loading. The new estimation method also predicted measured ESPVRs better than prior techniques and was applicable to noninvasive analysis.

Conclusions
ESPVRs can be reliably estimated in humans from single cardiac cycles by a new method that has a potential for noninvasive application.
Selective Effects of Oxygen Free Radicals on Excitation-Contraction Coupling in Ventricular Muscle
Authors: Gao Wei Dong , Liu Yongge , Marban Eduardo
Published: June 2012

Background
Oxygen free radicals (OFRs) have been implicated in the pathogenesis of myocardial stunning, but the precise mechanism by which OFRs foster stunning remains unclear. We investigated the pathophysiology of the contractile dysfunction that occurs after direct exposure of OFRs to cardiac muscle and compared the results with the pathophysiology of stunned myocardium.

Methods and Results
Trabeculae from the right ventricles of rat hearts were loaded iontophoretically with fura-2 to determine [Ca
2+
]
i
. Steady-state force-[Ca
2+
]
i
relations were obtained by rapid electrical stimulation in the presence of ryanodine. Two exogenous OFR-generating systems were used: H
2
O
2
+Fe
3+
-nitrilotriacetic acid (H
2
O
2
+Fe
3+
) to produce hydroxyl radical, and xanthine oxidase+purine (XO+P) to produce superoxide. In muscles exposed to H
2
O
2
+Fe
3+
for 10 minutes, both twitch force and Ca
2+
transients were decreased (eg, in 1.5 mmol/L external [Ca
2+
], force decreased from 41±7 to 23±4 mN/mm
2
,
P
<.05, and Ca
2+
transient amplitude from 0.96±0.09 to 0.70±0.05 μmol/L,
P
<.05). Maximal Ca
2+
-activated force (F
max
) decreased slightly, from 103±5 to 80±12 mN/mm
2
(
P
=NS). Neither the [Ca
2+
]
i
required to achieve 50% of F
max
(Ca
50
) nor the Hill coefficient was changed. In muscles exposed to XO+P for 20 minutes, twitch force was reduced (in 1.5 mmol/L external [Ca
2+
]) from 50±9 to 39±8 mN/mm
2
(
P
<.05). Ca
2+
transients, on the other hand, were not affected. F
max
decreased insignificantly from 100±16 to 81±14 mN/mm
2
. Ca
50
increased from 0.71±0.06 to 1.07±0.07 μmol/L (
P
<.05), with no change in the Hill coefficient.

Conclusions
These results indicate that exposure to the H
2
O
2
+Fe
3+
free radical–generating system reduces activator Ca
2+
availability, whereas XO+P decreases the Ca
2+
sensitivity of the myofilaments. Exogenously generated OFRs, particularly those produced by XO+P, mimic the effects of myocardial stunning on cardiac excitation-contraction coupling.
Activation of JAK-STAT and MAP Kinases by Leukemia Inhibitory Factor Through gp130 in Cardiac Myocytes
Authors: Kunisada Keita , Hirota Hisao , Fujio Yasushi , Matsui Hideo , Tani Yoshihiko , Yamauchi-Takihara Keiko , Kishimoto Tadamitsu
Published: June 2012

Background
Interleukin (IL)-6–related cytokines share gp130 as the signal-transducing protein. Downstream of gp130, two signal-transducing pathways have been recognized, the Janus kinase–signal transducer and activator of transcription (JAK-STAT) pathway and the Ras–mitogen-activated protein kinase (MAPK) pathway. To determine whether these two signaling pathways through gp130 are present in cardiac myocytes, we examined their activation by using leukemia inhibitory factor (LIF), which is a member of the IL-6 cytokine family.

Methods and Results
Lysates from neonatal rat cardiac myocytes were immunoprecipitated with anti-gp130, anti-JAK1, or anti-STAT3 antibody and blotted with anti-phosphotyrosine antibody. Tyrosine phosphorylation of gp130, JAK1, and STAT3 was observed after LIF stimulation in cardiac myocytes. MAPKs were maximally activated 5 minutes after LIF stimulation. Furthermore, anti-gp130 antibody significantly inhibited the LIF-induced activation of JAK1, STAT3, and MAPKs. To examine whether these signaling pathways were also activated in the adult heart in vivo, LIF was injected intravenously into a 6-week-old mouse, and the heart was examined subsequently. gp130, STAT3, and MAPKs were activated in the heart after LIF treatment.

Conclusions
These results demonstrate for the first time that a JAK-STAT pathway and a MAPK pathway are present downstream of gp130 in cardiac myocytes and are rapidly activated by LIF both in vitro and in vivo. Activation of gp130 constitutes a novel signaling pathway in cardiac myocytes.
Incomplete Reentry and Epicardial Breakthrough Patterns During Atrial Fibrillation in the Sheep Heart
Authors: Gray Richard A. , Pertsov Arkady M. , Jalife Jose´
Published: June 2012

Background
The mechanisms underlying atrial fibrillation and its initiation are not fully understood. Our hypothesis is that atrial fibrillation results from complex activation involving the subendocardial muscle network.

Methods and Results
We have used video imaging to study the sequence of activation on the surface of the right atrium of the Langendorff-perfused sheep heart during pacing, atrial fibrillation, and its initiation. We recorded transmembrane potentials simultaneously from over 20 000 sites. We observed two types of patterns of wave propagation during the initiation of atrial fibrillation. The first type resulted from heterogeneities of refractoriness and transmural propagation near the stimulating electrode. The second type involved heterogeneity in conduction away from the pacing site. During atrial fibrillation, the average period of activation was 138±25 ms (n=6), and complete reentrant pathways were never observed. Propagation patterns were characterized by a combination of incomplete reentry, breakthrough patterns, and wave collisions. Incomplete reentry occurred when waves propagated around thin lines of block and then terminated. Breakthrough patterns were frequent and occurred every 215 ms on average. The location of these breakthrough sites and the lines of block during incomplete reentry were not randomly distributed but appeared to be related to preferential propagation in the underlying subendocardial muscle structures. A computer model of atrial free wall connected to a pectinate muscle suggested that subendocardial muscles lead to epicardial breakthrough patterns that act to destabilize reentry.

Conclusions
These results suggest that the complex three-dimensional structure of the atria plays a major role in the activation sequences during atrial fibrillation and its initiation.
Fibrillin-1 (FBN1) Mutations in Patients With Thoracic Aortic Aneurysms
Authors: Milewicz Dianna M. , Michael Kristi , Fisher Nancy , Coselli Joseph S. , Markello Thomas , Biddinger Alan
Published: June 2012

Background
Mutations in the FBN1 gene are the cause of the Marfan syndrome, an autosomal dominant disorder with skeletal, ocular, and cardiovascular complications. Aneurysms or dissections of the ascending thoracic aorta are the major cardiovascular complications of the disorder. We tested the hypothesis that FBN1 mutations cause thoracic aortic aneurysms or dissections in patients who do not have the Marfan syndrome.

Methods and Results
The FBN1 gene was screened for mutations by use of genomic DNA from two patients with thoracic aortic aneurysms who did not have the Marfan syndrome. Individual FBN1 exons were amplified with intron-based exon-specific primers; the DNA fragments were screened for mutations using single-stranded conformational polymorphism analysis; and aberrantly migrating bands were sequenced directly. We identified a missense mutation in one patient, D1155N in exon 27. Dermal fibroblasts from the affected individual were used to study the effect of the missense mutation D1155N on fibrillin-1 cellular processing. The mutation decreased the amount of fibrillin-1 deposited into the pericellular matrix. A second putative FBN1 mutation was identified in the second patient, P1837S in exon 44. Although this alteration was not observed in 234 chromosomes from unrelated individuals, the alteration may represent a rare polymorphism.

Conclusions
Results of these studies support the hypothesis that FBN1 mutations cause thoracic aortic aneurysms in patients who do not have the Marfan syndrome. This information is important for understanding the pathogenesis of aortic aneurysms and identification of individuals at risk for developing thoracic aortic aneurysms or dissections.