bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence for a Proinflammatory and Proteolytic Environment in Plaques From Endarterectomy Segments of Human Carotid Arteries
Authors: Formato Marilena , Farina Miriam , Spirito Rita , Maggioni Marco , Guarino Anna , Cherchi Gian Mario , Biglioli Paolo , Edelstein Celina , Scanu Angelo M.
Published: November 2003

Objectives

Based on previous observations on apolipoprotein(a), apo(a), in human unstable carotid plaques, we explored whether in the inflammatory environment of human atheroma, proteolytic events affect other hepatic and topically generated proteins in relation to the issue of plaque stability.

Methods and Results

Forty unstable and 24 stable plaques from endarterectomy segments of affected human carotid arteries were extracted with buffered saline (PBS) and then 6 mol/L guanidine-hydrochloride (GdHCl) to identify loosely and tightly bound products, respectively. The extracts were studied before and after ultracentrifugation at d 1.21 g/mL. In the extracts, the concentrations of interleukin (IL)-6, −8, and −18 were significantly higher in the unstable plaques and correlated to those of MMP-2 and MMP-9. By Western blots, both apoB and apo(a) were highly fragmented and mostly present in the d 1.21 bottom that also contained fragments of apoE (10 and 22 kDa), decorin, biglycan, and versican. Fragmentation was higher in the unstable plaques. In baseline plasmas, concentrations of lipids, lipoproteins, and ILs did not differ between patients with unstable and stable plaques.

Conclusions

In unstable and to a lesser extent in stable plaques, there is a proinflammatory and proteolytic microenvironment with the generation of fragments with potential pathobiological significance that requires investigation.
C-Reactive Protein Stimulates MMP-1 Expression in U937 Histiocytes Through FcγRII and Extracellular Signal-Regulated Kinase Pathway:
Authors: Williams Takeyla N. , Zhang Cecelia X. , Game Bryan A. , He Lin , Huang Yan
Published: November 2003

Objective—

It has been shown that plasma level of C-reactive protein (CRP) is an independent predictor for acute coronary syndromes and is associated with plaque weakening. However, the underlying mechanisms are not well understood. In this study, we investigated the effect of CRP on the expression of matrix metalloproteinase-1 (MMP-1) that has been implicated in plaque vulnerability by human U937 histiocytes and monocyte-derived macrophages.

Methods and Results—

Enzyme-linked immunosorbent assay of MMP-1 in conditioned medium showed that treatment of U937 cells with 100 μg/mL of CRP for 24 hour led to a 3- to 5-fold increase in MMP-1 secretion. CRP also markedly stimulated MMP-1 release from human monocyte-derived macrophages. In contrast, CRP had no effect on tissue inhibitor of metalloproteinase-1 (TIMP-1) secretion. Northern blot showed that CRP upregulated MMP-1 mRNA expression. Collagenase activity assay showed that CRP increased collagen-degrading activity in cell-conditioned medium. Furthermore, results showed that the stimulation of MMP-1 secretion by CRP was inhibited by anti-CD32, but not by anti-CD64 antibody, and by mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK) inhibitor PD98059. Finally, Western blot showed that CRP stimulated phosphorylation of extracellular signal-regulated kinase.

Conclusions—

This study demonstrates that CRP stimulates MMP-1 expression by U937 cells through FcγRII and extracellular signal-regulated kinase pathway. These findings suggest that CRP may promote matrix degradation and thus contribute to plaque vulnerability.
Quantitative Trait Loci Analysis for Plasma HDL-Cholesterol Concentrations and Atherosclerosis Susceptibility Between Inbred Mouse Strains C57BL/6J and 129S1/SvImJ
Authors: Ishimori Naoki , Li Renhua , Kelmenson Peter M. , Korstanje Ron , Walsh Kenneth A. , Churchill Gary A. , Forsman-Semb Kristina , Paigen Beverly
Published: November 2003

Objective—

The C57BL/6 (B6) and 129 mouse inbred strains differ markedly in plasma HDL-cholesterol concentrations and atherosclerosis susceptibility after a high-fat diet consumption. To identify loci controlling these traits, we performed quantitative trait loci (QTL) analysis.

Methods and Results—

We fed a high-fat diet to 294 (B6x129S1/SvImJ)F
2
females for 14 weeks, measured plasma HDL concentrations and size of aortic fatty-streak lesions, genotyped F
2
females, and performed QTL analysis. HDL concentrations were affected by six loci:
Hdlq14
and
Hdlq15
on chromosome 1 (peaks cM 80 and cM 104, logarithm of odds [LOD] 5.3 and 9.7, respectively);
Hdlq16
on chromosome 8 (cM 44, LOD 2.6);
Hdlq17
on chromosome 9 (cM 24, LOD 2.9);
Hdlq18
on chromosome 12 (cM 20, LOD 5.9); and
Hdlq19
on chromosome 2 (cM 90), which interacted with
Hdlq15
. Atherosclerosis susceptibility was affected by five loci:
Ath17
on chromosome 10 (cM 34, LOD 6.6);
Ath18
on chromosome 12 (cM 16, LOD 3.7);
Ath19
(chromosome 11, cM 60), which interacted with
Ath18
; and
Ath20
(chromosome 10, cM 10), which interacted with
Ath21
(chromosome 12, cM 50).

Conclusions—

We identified six loci for HDL and five loci for atherosclerosis susceptibility in a (B6x129S1/SvImJ)F
2
intercross.
Vitamin E Supplementation in Patients With Carotid Atherosclerosis
Authors: Micheletta Fausta , Natoli Silvia , Misuraca Maria , Sbarigia Enrico , Diczfalusy Ulf , Iuliano Luigi
Published: November 2003

Objective—Oxidative stress is believed to play a pivotal role in the initiation and progression of atherosclerosis. We analyzed whether vitamin E supplementation influences oxidative stress in plasma and atherosclerotic plaques of patients with severe atherosclerosis.

Methods and Results—In 16 patients who were candidates for carotid endarterectomy and in 32 age- and sex-matched controls, plasma levels of 7β-hydroxycholesterol, 7-ketocholesterol, cholesterol, and vitamin E were measured. Patients were randomly allocated to standard treatment with or without 900 mg/d vitamin E. After 6 weeks of treatment, the reported variables were measured in plasma and plaques. The plasma vitamin E/cholesterol ratio was significantly lower in patients than in controls (3.05±0.6 versus 6.3±1.7 μmol/mmol cholesterol,P<0.001). Plasma 7β-hydroxycholesterol was significantly higher in patients than in controls (5.0±1.04 versus 4.4±0.6 ng/mL,P<0.05). Patients who were given vitamin E supplementation showed a significant increase of plasma vitamin E with concomitant decrease of 7β-hydroxycholesterol. Conversely, no treatment dependence was observed in oxysterol or vitamin E content of plaques.

Conclusions—An imbalance between oxidative stress and antioxidant status is present in patients with advanced atherosclerosis. Vitamin E supplementation improves this imbalance in plasma but not in plaques.
Upregulation of Vascular Extracellular Superoxide Dismutase in Patients With Acute Coronary Syndromes
Authors: Horiuchi Masataka , Tsutsui Masato , Tasaki Hiromi , Morishita Tsuyoshi , Suda Osamu , Nakata Sei , Nihei Shun-ichi , Miyamoto Masaharu , Kouzuma Ryoji , Okazaki Masahiro , Yanagihara Nobuyuki , Adachi Tetsuo , Nakashima Yasuhide
Published: November 2003

Objective—

We examined the vascular expression levels of extracellular superoxide dismutase (EC-SOD), a major antioxidant enzyme in the cardiovascular system, in patients with acute coronary syndromes.

Methods and Results—

Twenty-one consecutive patients with acute myocardial infarction (AMI), 14 patients with unstable angina, 11 patients with stable angina, and 20 control subjects were studied. The levels of vascular EC-SOD expression were assessed by the difference in plasma EC-SOD concentrations before and after intravenous heparan injection. In the patients with AMI, vascular EC-SOD expression (ng/mL) was significantly higher on day 1 after the onset of AMI (148±10) as compared with the control subjects (116±6,
P
<0.05). The vascular EC-SOD expression returned to the normal range on day 7 (104±8), and that level persisted thereafter. The vascular EC-SOD expression was also significantly higher in the patients with unstable angina (160±13) than in those with stable angina (122±10) or in the controls (116±6) (
P
<0.05 each). Moreover, in the patients with AMI, higher levels of vascular EC-SOD expression on day 1 were significantly associated with smaller myocardial infarct size (
P
<0.05).

Conclusions—

This is the first clinical demonstration showing that vascular EC-SOD may be upregulated in acute coronary syndromes in humans in vivo. EC-SOD may play an important protective role against increased oxidative stress during acute ischemic coronary events.
Quantitative Trait Locus Mapping of Genes That Regulate Phospholipid Transfer Activity in SM/J and NZB/BlNJ Inbred Mice
Authors: Korstanje Ron , Albers John J. , Wolfbauer Gertrud , Li Renhua , Tu An-Yue , Churchill Gary A. , Paigen Beverly J.
Published: November 2003

Objective

Phospholipid transfer protein (PLTP), an important protein in the transfer of phospholipids between lipoprotein particles and in the remodeling of HDL, is regulated at both the transcriptional and the protein level. We performed quantitative trait locus (QTL) analysis to identify genomic loci regulating PLTP activity in mice.

Methods and Results

Plasma PLTP activity was measured in 217 male F
2
progeny from a SM/J × NZB/B1NJ intercross. Two QTL for plasma PLTP activity in mice fed chow (
Pltpq1
and
Pltpq2
) were found on chromosomes 3 (34 cM, logarithm of odds [LOD] 3.5) and 10 (66 cM, LOD 4.1); two additional QTL in mice fed atherogenic diet (
Pltpq3
and
Pltpq4
) were found on chromosomes 9 (56 cM, LOD 4.5) and 15 (34 cM, LOD 5.0); and one QTL (
Pltiq1
) for the inducibility of PLTP activity was found on chromosome 4 (70 cM, LOD 3.7). Several candidate genes for these 5 QTL were tested by sequence comparison and expression studies.

Conclusions

We identified five significant loci involved in PLTP activity in the mouse and provided supporting evidence for the candidacy of
Nr1h4
and
Apof
as the genes underlying
Pltpq2
.
Anticoagulants (Thrombin Inhibitors) and Aspirin Synergize With P2Y
12
Receptor Antagonism in Thrombosis
Authors: André Patrick , LaRocca Thomas , Delaney Suzanne M. , Lin Pei Hua , Vincent Diana , Sinha Uma , Conley Pamela B. , Phillips David R.
Published: November 2003

Background—

This study was designed to determine whether (1) P2Y
12
antagonism synergizes with other antithrombotics and (2) anticoagulants (thrombin inhibitors) affect the antithrombotic activity elicited by P2Y
12
antagonism.

Methods and Results—

Thrombosis was achieved by perfusion of human and murine blood through type III collagen–coated capillaries at arterial shear rate. CT50547, a direct-acting P2Y
12
antagonist, inhibited thrombosis in PPACK- but not heparin-anticoagulated human blood. In contrast, CT50547 inhibited thrombosis in aspirin-treated individuals independently of the anticoagulant. Thrombin and TXA
2
also synergized with P2Y
12
in the absence of anticoagulation, because combined treatment of aspirin or C921-78 (a factor Xa inhibitor) with CT50547 or 2-MeSAMP (a P2Y
12
antagonist) inhibited the thrombotic process, whereas all treatments failed to inhibit thrombosis when used individually. Synergism was also observed ex vivo when P2Y
12
-deficient (P2Y
12
−/−
) mice were administered aspirin or coagulation inhibitors (C921-78 and bivalirudin). Finally, using intravital microscopy, we found that both C921-78 and bivalirudin abrogated the thrombotic process in P2Y
12
+/
−
mice, whereas each showed only partial efficacy in P2Y
12
+/+
animals.

Conclusions—

Our study indicates that (1) thrombin inhibitors and aspirin have a demonstrable synergy of antithrombotic activity with P2Y
12
antagonism and (2) the in vitro analysis of the antithrombotic activity of P2Y
12
antagonists is affected by the anticoagulant used for blood collection. This suggests that the antithrombotic potential of P2Y
12
antagonists in vitro may be overestimated in anticoagulated samples of blood and best achieved in vivo by the inclusion of aspirin and/or a thrombin inhibitor.
Control of Skin Sympathetic Nerve Activity During Intermittent Static Handgrip Exercise
Authors: Leuenberger Urs A. , Mostoufi-Moab Sogol , Herr Michael , Gray Kristen , Kunselman Allen , Sinoway Lawrence I.
Published: November 2003

Background—Exercise activates the sympathetic nervous system as a function of the type and intensity of exercise and of the target organ studied. Although central command and activity of metabolically sensitive afferents from exercising muscle are the principal determinants of sympathetic outflow directed to skeletal muscle, the mechanisms that govern sympathetic outflow directed to skin are less clear.

Methods and Results—We measured skin sympathetic nerve activity (SSNA) during intermittent static handgrip (SHG; at 45% of maximal voluntary contraction; four 5-second contractions per minute for 3 minutes), during unrestricted forearm perfusion (control), during stimulation of forearm mechanoreceptors with venous congestion, and during ischemia produced by forearm circulatory arrest. Under all 3 conditions, SSNA increased within 1 to 2 seconds of the onset of handgrip. During ischemia but not during venous congestion, SSNA increased more compared with control (P<0.05) and remained elevated when forearm ischemia was maintained after handgrip exercise (posthandgrip circulatory arrest). In addition, simulated handgrip and intermittent forearm compression produced by a pneumatic cuff also evoked brief increases of SSNA.

Conclusions—In addition to central neural factors, afferent input from exercising muscle plays an important role in modulating sympathetic outflow directed to skin.
Isolation and Transplantation of Autologous Circulating Endothelial Cells Into Denuded Vessels and Prosthetic Grafts
Authors: Griese Daniel P. , Ehsan Afshin , Melo Luis G. , Kong Deling , Zhang Lunan , Mann Michael J. , Pratt Richard E. , Mulligan Richard C. , Dzau Victor J.
Published: November 2003

Background—

Blood-borne endothelial cells originating from adult bone marrow were reported previously. These cells have the properties of an endothelial progenitor cell (EPC) and can be mobilized by cytokines and recruited to sites of neovascularization, where they differentiate into mature endothelial cells. Current protocols for isolation of EPCs from peripheral blood rely on enrichment and selection of CD34+ mononuclear cells.

Methods and Results—

In this report, we describe a streamlined method for the isolation and expansion of EPCs from peripheral blood and evaluate their therapeutic potential for autologous cell-based therapy of injured blood vessels and prosthetic grafts. A subset of unfractionated mononuclear cells exhibited the potential to differentiate in vitro into endothelial cells under selective growth conditions. The cells were efficiently transduced ex vivo by a retroviral vector expressing the LacZ reporter gene and could be expanded to yield sufficient numbers for therapeutic applications. Transplantation of these cells into balloon-injured carotid arteries and into bioprosthetic grafts in rabbits led to rapid endothelialization of the denuded vessels and graft segments, resulting in significant reduction in neointima deposition.

Conclusions—

We conclude that transplantation of EPCs may play a crucial role in reestablishing endothelial integrity in injured vessels, thereby inhibiting neointimal hyperplasia. These findings may have implications for novel and practical cell-based therapies for vascular disease.
Myocardial Contractile Reserve by Dobutamine Stress Echocardiography Predicts Improvement in Ejection Fraction With β-Blockade in Patients With Heart Failure
Authors: Eichhorn Eric J. , Grayburn Paul A. , Mayer Susan A. , St John Sutton Martin , Appleton Christopher , Plehn Jonathan , Oh Jae , Greenberg Barry , DeMaria Anthony , Frantz Robert , Krause-Steinrauf Heidi
Published: November 2003

Background—

β-Blockers improve survival and reduce hospitalization in chronic heart failure (CHF) by biologically improving left ventricular ejection fraction (LVEF). However, a good predictor of improvement with this therapy has not been identified. This substudy of BEST examined whether myocardial contractile reserve, as determined by dobutamine stress echocardiography, predicts improvement in LVEF.

Methods and Results—

Seventy-nine patients with class III/IV CHF underwent dobutamine stress echocardiography before treatment with bucindolol (n=41) or placebo (n=38). Regional wall motion score index (WMSI) was calculated as the sum of the scores in each segment divided by the total number of segments visualized. WMSI was compared with change in LVEF after 3 months of therapy as determined by gated radionuclide scan. Change in WMSI correlated inversely with change in LVEF after 3 months of bucindolol (
r
=−0.72,
P
<0.0001) and was the most significant multivariate predictor of change in LVEF (
P
=0.0002). Patients with contractile reserve had demographics similar to those of patients without contractile reserve, including RVEF, LVEF, systolic blood pressure, and CHF duration. However, patients without contractile reserve had higher baseline plasma norepinephrine levels (687±333 versus 420±246 pg/mL,
P
<0.05) and greater decrease in plasma norepinephrine in response to bucindolol (−249±171 versus −35±277 pg/mL,
P
<0.05).

Conclusions—

This study suggests a direct relationship between contractile reserve and improvement in LVEF with β-blocker therapy in patients with advanced CHF. Patients without contractile reserve have higher resting adrenergic drive, as reflected by plasma norepinephrine, and may experience greater sympatholytic effects from bucindolol.
Women’s Early Warning Symptoms of Acute Myocardial Infarction
Authors: McSweeney Jean C. , Cody Marisue , O’Sullivan Patricia , Elberson Karen , Moser Debra K. , Garvin Bonnie J.
Published: November 2003

Background—

Data remain sparse on women’s prodromal symptoms before acute myocardial infarction (AMI). This study describes prodromal and AMI symptoms in women.

Methods and Results—

Participants were 515 women diagnosed with AMI from 5 sites. Using the McSweeney Acute and Prodromal Myocardial Infarction Symptom Survey, we surveyed them 4 to 6 months after discharge, asking about symptoms, comorbidities, and demographic characteristics. Women were predominantly white (93%), high school educated (54.8%), and older (mean age, 66±12), with 95% (n=489) reporting prodromal symptoms. The most frequent prodromal symptoms experienced more than 1 month before AMI were unusual fatigue (70.7%), sleep disturbance (47.8%), and shortness of breath (42.1%). Only 29.7% reported chest discomfort, a hallmark symptom in men. The most frequent acute symptoms were shortness of breath (57.9%), weakness (54.8%), and fatigue (42.9%). Acute chest pain was absent in 43%. Women had more acute (mean, 7.3±4.8; range, 0 to 29) than prodromal (mean, 5.71±4.36; range, 0 to 25) symptoms. The average prodromal score, symptom weighted by frequency and intensity, was 58.5±52.7, whereas the average acute score, symptom weighted by intensity, was 16.5±12.1. These 2 scores were correlated (
r
=0.61,
P
<0.001). Women with more prodromal symptoms experienced more acute symptoms. After controlling for risk factors, prodromal scores accounted for 33.2% of acute symptomatology.

Conclusions—

Most women have prodromal symptoms before AMI. It remains unknown whether prodromal symptoms are predictive of future events.
Sex Differences in Health Status After Coronary Artery Bypass Surgery
Authors: Vaccarino Viola , Lin Zhen Qiu , Kasl Stanislav V. , Mattera Jennifer A. , Roumanis Sarah A. , Abramson Jerome L. , Krumholz Harlan M.
Published: November 2003

Background—

Although previous studies have shown functional improvements in patients who undergo coronary artery bypass graft (CABG) surgery, data are conflicting on whether the gains achieved by women are similar to or less than those achieved by men.

Methods and Results—

We compared physical and psychological functional gains and readmission rates between 777 men and 295 women who underwent first CABG consecutively between February 1999 and February 2001. Physical function and mental health were measured by means of the Short Form 36-Item Health Survey (SF-36). At 6 months, both men and women showed, on average, a significant improvement in physical function and mental health, but men improved significantly more than women. After adjustment for baseline characteristics, the mean score improvement in women was half that of men for physical function (7.3 versus 14.0,
P
=0.0002) and 25% less than that of men for mental health (−3.0 versus 8.9,
P
=0.026). The absolute rates of adverse outcomes, such as hospital readmission, worsening functional status, and worsening mental health, were significantly higher in women (32.6%, 25.7%, and 17.5%, respectively) than in men (21.2%, 11.1%, and 12.6%, respectively) and remained significantly different in multivariable analysis.

Conclusions—

CABG surgery is associated with lower functional gains and higher readmission rates in women compared with men 6 months after operation.
Hospitalization Costs of Primary Stenting Versus Thrombolysis in Acute Myocardial Infarction
Authors: Le May Michel R. , Davies Richard F. , Labinaz Marino , Sherrard Heather , Marquis Jean-François , Laramée Louise A. , O’Brien Edward R. , Williams William L. , Beanlands Rob S. , Nichol Graham , Higginson Lyall A.
Published: November 2003

Background—

We previously showed that primary stenting was more effective than accelerated tPA in reducing the 6-month composite of death, reinfarction, stroke, or repeat revascularization for ischemia. This study looks at the hospitalization costs of primary stenting compared with accelerated tPA.

Methods and Results—

Initial and 6-month hospitalization costs were computed for all patients randomly assigned to primary stenting (n=62) or accelerated tPA (n=61) in the Stenting versus Thrombolysis in Acute myocardial infarction Trial (STAT). Costs and resource usage were collected in detail for each patient. Physician fees were obtained directly from billings to the Ontario Health Insurance Plan. The length of initial hospitalization was 6.7±11.3 days in the stent group and 8.7±6.7 days in the tPA group (
P
<0.001). Total hospitalization days at 6 months were 8.3±13 days in the stent group and 12.1±14.0 days in the tPA group (
P
=0.001). Hospitalization costs were less in the stent group for the initial hospitalization, $6354±6382 versus $7893±4429 (
P
=0.001), and at 6 months, $7100±7111 versus $9559±6933 (
P
=0.001).

Conclusions—

In centers in which facilities and experienced interventionists are available, primary stenting is less costly and more effective than thrombolysis.
Inhibition of δ-Protein Kinase C Protects Against Reperfusion Injury of the Ischemic Heart In Vivo
Authors: Inagaki Koichi , Chen Leon , Ikeno Fumiaki , Lee Felix H. , Imahashi Ken-ichi , Bouley Donna M. , Rezaee Mehrdad , Yock Paul G. , Murphy Elizabeth , Mochly-Rosen Daria
Published: November 2003

Background—

Current treatment for acute myocardial infarction (AMI) focuses on reestablishing blood flow (reperfusion). Paradoxically, reperfusion itself may cause additional injury to the heart. We previously found that δ-protein kinase C (δPKC) inhibition during simulated ischemia/reperfusion in isolated rat hearts is cardioprotective. We focus here on the role for δPKC during reperfusion only, using an in vivo porcine model of AMI.

Methods and Results—

An intracoronary application of a selective δPKC inhibitor to the heart at the time of reperfusion reduced infarct size, improved cardiac function, inhibited troponin T release, and reduced apoptosis. Using
31
P NMR in isolated perfused mouse hearts, we found a faster recovery of ATP levels in hearts treated with the δPKC inhibitor during reperfusion only.

Conclusions—

Reperfusion injury after cardiac ischemia is mediated, at least in part, by δPKC activation. This study suggests that including a δPKC inhibitor at reperfusion may improve the outcome for patients with AMI.
Differential Effects of Selective Cyclooxygenase-2 Inhibitors on Endothelial Function in Salt-Induced Hypertension
Authors: Hermann Matthias , Camici Giovanni , Fratton Aisha , Hurlimann David , Tanner Felix C. , Hellermann Jens P. , Fiedler Martin , Thiery Joachim , Neidhart Michel , Gay Renate E. , Gay Steffen , Lüscher Thomas F. , Ruschitzka Frank
Published: November 2003

Background—

In view of the ongoing controversy about potential differences in cardiovascular safety of selective cyclooxygenase (COX)-2 inhibitors (coxibs), we compared the effects of 2 different coxibs and a traditional NSAID on endothelial dysfunction, a well-established surrogate of cardiovascular disease, in salt-induced hypertension.

Methods and Results—

Salt-sensitive (DS) and salt-resistant (DR) Dahl rats were fed a high-sodium diet (4% NaCl) for 56 days. From days 35 to 56, diclofenac (6 mg · kg
−1
· d
−1
; DS-diclofenac), rofecoxib (2 mg · kg
−1
· d
−1
; DS-rofecoxib), celecoxib (25 mg · kg
−1
· d
−1
; DS-celecoxib) or placebo (DS-placebo) was added to the chow. Blood pressure increased with sodium diet in the DS groups, which was more pronounced after diclofenac and rofecoxib treatment (
P
<0.005 versus DS-placebo) but was slightly decreased by celecoxib (
P
<0.001 versus DS-placebo). Sodium diet markedly reduced NO-mediated endothelium-dependent relaxations to acetylcholine (10
−10
-10
−5
mol/L) in aortic rings of untreated hypertensive rats (
P
<0.005 versus DR-placebo). Relaxation to acetylcholine improved after celecoxib (
P
<0.005 versus DS-placebo and DS-rofecoxib) but remained unchanged after rofecoxib and diclofenac treatment. Vasoconstriction after nitric oxide synthase inhibition, indicating basal NO release, with
N
ω
-nitro-
l
-arginine methyl ester (10
−4
mol/L) was blunted in DS rats (
P
<0.05 versus DR-placebo), normalized by celecoxib, but not affected by rofecoxib or diclofenac. Indicators of oxidative stress, 8-isoprostane levels, were elevated in untreated DS rats on 4% NaCl (6.55±0.58 versus 3.65±1.05 ng/mL,
P
<0.05) and normalized by celecoxib only (4.29±0.58 ng/mL).

Conclusions—

These data show that celecoxib but not rofecoxib or diclofenac improves endothelial dysfunction and reduces oxidative stress, thus pointing to differential effects of coxibs in salt-induced hypertension.
Association Between Blood Pressure and C-Reactive Protein Levels in Acute Ischemic Stroke
Authors: Di Napoli Mario , Papa Francesca
Published: November 2003

Among patients with acute stroke, high blood pressure (BP) and higher levels of circulating C-reactive protein (CRP) at the entry are often associated with poor outcome, although the reason is unclear. If the link between BP and stroke outcome is indeed mediated by inflammatory response, one would expect to see positive associations between BP and CRP. In a prospective observational stroke data bank involving 535 first-ever ischemic stroke patients, we studied the association between BP and baseline concentrations of CRP within 24 hours after stroke onset. The association between BP components and the odds of having an elevated CRP level (≥1.5 mg/dL) was assessed by logistic regression analysis. An increase in systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), or pulse pressure (PP) was significantly associated with an increase in the odds of having an elevated CRP level, independent of other associated study factors. For each 10 mm Hg increase in SBP, DBP, MAP, or PP, the odds of having a high CRP level increased by 72% (
P
<0.0001), 10% (
P
<0.0001), 21% (
P
<0.0001), and 10% (
P
<0.0001), respectively. When the same model was rerun, adjusting for all considered BP components, only SBP significantly increased the odds of an elevated CRP level by 77% (
P
<0.0001). Increased SBP was significantly associated with elevated levels of circulating CRP in ischemic stroke patients. These findings support a possible role of acute hypertension after stroke as an inflammatory stimulus contributing to ischemic brain inflammation.
Blood Pressure Lowering in Essential Hypertension With an Oral Renin Inhibitor, Aliskiren
Authors: Stanton Alice , Jensen Chris , Nussberger Juerg , O'Brien Eoin
Published: November 2003

Inhibition of the first and rate-limiting step of the renin-angiotensin system has long been an elusive therapeutic goal. Aliskiren, the first known representative of a new class of completely nonpeptide, orally active, renin inhibitors, has been shown to inhibit the production of angiotensin I and II in healthy volunteers and to reduce blood pressure (BP) in sodium-depleted marmosets. The aim of this randomized, double-blind, active comparator trial study was to assess the BP-lowering efficacy and safety of aliskiren. Two hundred twenty-six patients, 21 to 70 years of age, with mild to moderate hypertension, were randomly assigned to receive 37.5 mg, 75 mg, 150 mg, or 300 mg aliskiren or 100 mg losartan daily for 4 weeks. Dose-dependent reductions in daytime ambulatory systolic pressure (mean change, mm Hg [SD of change]; −0.4 [11.7], −5.3 [11.3], −8.0 [11.0], and −11.0 [11.0],
P
=0.0002) and in plasma renin activity (median change % [interquartile range]; −55 [−64, −11], −60 [−82, −46], −77 [−86, −72], and −83 [−92, −71],
P
=0.0008) were observed with 37.5, 75, 150, and 300 mg aliskiren. The change in daytime systolic pressure with 100 mg losartan (−10.9 [13.8]) was not significantly different from the changes seen with 75, 150, and 300 mg aliskiren. Aliskiren was well tolerated at all doses studied. This study demonstrates that aliskiren, through inhibition of renin, is an effective and safe orally active BP-lowering agent. Whether renin inhibition results in protection from heart attack, stroke, and nephropathy, similar to angiotensin-converting enzyme inhibition and angiotensin receptor blockade, needs to be researched.
Regulation of Catecholamines by Sustained and Intermittent Hypoxia in Neuroendocrine Cells and Sympathetic Neurons
Authors: Hui Anna S. , Striet Justin B. , Gudelsky Gary , Soukhova Galia K. , Gozal Evelyne , Beitner-Johnson Dana , Guo Shang-Z. , Sachleben Leroy R. , Haycock John W. , Gozal David , Czyzyk-Krzeska Maria F.
Published: November 2003

Chronic intermittent hypoxia, a characteristic feature of sleep-disordered breathing, induces hypertension through augmented sympathetic nerve activity and requires the presence of functional carotid body arterial chemoreceptors. In contrast, chronic sustained hypoxia does not alter blood pressure. We therefore analyzed the biosynthetic pathways of catecholamines in peripheral nervous system structures involved in the pathogenesis of intermittent hypoxia-induced hypertension, namely, carotid bodies, superior cervical ganglia, and adrenal glands. Rats were exposed to either intermittent hypoxia (90 seconds of room air alternating with 90 seconds of 10% O
2
) or to sustained hypoxia (10% O
2
) for 1 to 30 days. Dopamine, norepinephrine, epinephrine, dihydroxyphenylacetic acid, and 5-hydroxytyptamine contents were measured by high-performance liquid chromatography. Expression of tyrosine hydroxylase and its phosphorylated forms, dopamine β-hydroxylase, phenylethanolamine
N
-methyltransferase, and GTP cyclohydrolase-1 were determined by Western blot analyses. Both sustained and intermittent hypoxia significantly increased dopamine and norepinephrine content in carotid bodies but not in sympathetic ganglia or adrenal glands. In carotid bodies, both types of hypoxia augmented total levels of tyrosine hydroxylase protein and its phosphorylation on serines 19, 31, 40, as well as levels of GTP cyclohydrolase-1. However, the effects of intermittent hypoxia on catecholaminergic pathways were significantly smaller and delayed than those induced by sustained hypoxia. Thus, attenuated induction of catecholaminergic phenotype by intermittent hypoxia in carotid body may play a role in development of hypertension associated with sleep-disordered breathing. The effects of both types of hypoxia on expression of catecholaminergic enzymes in superior cervical neurons and adrenal glands were transient and small.
Effect of Blood Pressure on Early Decline in Kidney Function Among Hypertensive Men
Authors: Vupputuri Suma , Batuman Vecihi , Muntner Paul , Bazzano Lydia A. , Lefante John J. , Whelton Paul K. , He Jiang
Published: November 2003

Few cohort studies have examined the longitudinal association between change in blood pressure and decline in kidney function among treated hypertensive patients without chronic kidney disease. We conducted a nonconcurrent cohort study to examine the effects of blood pressure on estimated glomerular filtration rate and early kidney function decline (rise in serum creatinine ≥0.6 mg/dL during follow-up) among 504 African-American and 218 white hypertensive patients. Our results showed that each standard deviation higher treated systolic (18 mm Hg) and diastolic (10 mm Hg) blood pressure was associated with an average annual decline (95% confidence interval [CI]) in estimated glomerular filtration rate of −0.92 ([−1.49 to −0.36]
P
=0.001) and −0.83 ([−1.38 to −0.28]
P
=0.003) mL · min
−1
· 1.73 m
−2
, respectively, after adjustment for race, age, education, income, use of antihypertensive drugs, body mass index, and history of diabetes and dyslipidemia. Likewise, each standard deviation higher systolic and diastolic blood pressure was associated with relative risks (95% CIs) of 1.81 ([1.29 to 2.55]
P
<0.001) and 1.55 ([1.08 to 2.22]
P
=0.046), respectively, for early kidney function decline. Compared with patients with a blood pressure level <140/90 mm Hg, those with a blood pressure level ≥160/95 mm Hg had a −2.67 ([−4.01 to −1.32]
P
<0.001) mL · min
−1
· 1.73 m
−2
greater annual decline in estimated glomerular filtration rate and a 5.21-fold ([2.06 to 13.21]
P
<0.001) greater risk of early kidney function decline. Our study found that higher levels of treated blood pressure were positively and significantly related to early decline in kidney function among hypertensive men. These results indicate that better blood pressure control might prevent the onset of chronic kidney disease among hypertensives.
Neither Perceived Job Stress Nor Individual Cardiovascular Reactivity Predict High Blood Pressure
Authors: Fauvel Jean Pierre , M’Pio Ignasse , Quelin Pierre , Rigaud Jean-Pierre , Laville Maurice , Ducher Michel
Published: November 2003

We have reported that high job strain was associated with a significantly higher diastolic blood pressure (DBP) of 4.5 mm Hg during the working hours, irrespective of BP reactivity to a stress test. We report the final results of the first 5-year follow-up study, which aimed to assess the respective influences of perception of professional strain and cardiovascular reactivity to a mental stress test on BP. A cohort of 292 healthy subjects (mean±SEM age, 38±1 years) was followed up for progression to hypertension outcome, which was defined as an increase in systolic blood pressure (SBP) or DBP >7 mm Hg or a DBP >95 mm Hg during follow-up. None of the subjects was lost to follow-up, and 209 subjects completed the study. The high-strain (HS) group, representing 20.9% of the subjects, was compared with the remaining subjects (non-high-strain [NHS]). Similarly, the subjects with the highest BP stress reactivity (HR; 20.9% of subjects) were compared with the remaining subjects (NHR). Progression to hypertension was reached by 93 subjects (31.8%). Kaplan-Meier survival estimates revealed that neither HS nor HR increased the incidence of progression to hypertension. End-of-follow-up 24-hour ambulatory BPs that were similar in HS and NHS (120±2 vs 120±1 mm Hg, respectively) and in HR and NHR (122±2 vs 120±1 mm Hg, respectively) confirmed our findings. Age, alcohol, salt diet, body mass index, and occupation did not interfere with our results. In conclusion, cardiovascular HR and HS do not appear to be major risk markers for future high BP in healthy, young adults.
Endogenous Estrogens Influence Endothelial Function in Young Men
Authors: Lew Robert , Komesaroff Paul , Williams Maro , Dawood Tye , Sudhir Krishnankutty
Published: November 2003

Males produce endogenous estrogen from testosterone via the enzyme aromatase. Previous studies have suggested a role for endogenous estrogens in cardiovascular function in men. We examined the effects of endogenous estrogen suppression via aromatase inhibition on endothelial function, systemic arterial compliance, and lipoprotein levels in healthy young men. Using a placebo-controlled double-blind randomized design, 20 healthy men, aged 18 to 32 years, were randomized to receive either the aromatase inhibitor anastrozole (1 mg) or matching placebo. Hormone, lipid levels, C-reactive protein (CRP), and homocysteine were measured. Endothelial function, determined by flow-mediated dilation of the brachial artery, and systemic arterial compliance were assessed at baseline and after 6 weeks of treatment. There was a significant decrease in 17β-estradiol concentrations with aromatase inhibition, from 85.4±4.2 to 64.3±8.1 pmol/L (mean±SD,
P
=0.042). Compared with baseline, a significant decrease in flow-mediated dilation was observed in subjects taking anastrozole [median, 6.1% (range, 5.2 to 13.4) to 3.5% (2.0 to 5.7),
P
=0.034] but not in the placebo group. No changes were observed in nitroglycerin-induced endothelium-independent dilation in either group. There was no change in systemic arterial compliance with either aromatase therapy or placebo. There were no significant changes in lipoproteins, testosterone, DHEA, CRP, or homocysteine levels in either the anastrozole or placebo group. We conclude that suppression of endogenous estrogens with an aromatase inhibitor resulted in impairment of flow-mediated dilation without significant changes in lipoproteins, homocysteine, or CRP. Our results suggest that endogenous estrogens play a direct regulatory role in endothelial function in young healthy men.
Life-Threatening Thrombosis in Mice With Targeted Arg48-to-Cys Mutation of the Heparin-Binding Domain of Antithrombin
Authors: Dewerchin Mieke , Hérault Jean-Pascal , Wallays Goedele , Petitou Maurice , Schaeffer Paul , Millet Laurence , Weitz Jeffrey I. , Moons Lieve , Collen Désiré , Carmeliet Peter , Herbert Jean-Marc
Published: November 2003

Antithrombin (AT) inhibits thrombin and some other coagulation factors in a reaction that is dramatically accelerated by binding of a pentasaccharide sequence present in heparin/heparan-sulfate to a heparin-binding site on AT. Based on the involvement of R47 in the heparin/AT interaction and the frequent occurrence of R47 mutations in AT deficiency patients, targeted knock-in of the corresponding R48C substitution in AT in mice was performed to generate a murine model of spontaneous thrombosis. The mutation efficiently abolished the effect of heparin-like molecules on coagulation inhibition in vitro and in vivo. Mice homozygous for the mutation (AT
m/m
mice) developed spontaneous, life-threatening thrombosis, occurring as early as the day of birth. Only 60% of the AT
m/m
offspring reached weaning age, with further loss at different ages. Thrombotic events in adult homozygotes were most prominent in the heart, liver, and in ocular, placental, and penile vessels. In the neonate, spontaneous death invariably was associated with major thrombosis in the heart. This severe thrombotic phenotype underlines a critical function of the heparin-binding site of antithrombin and its interaction with heparin/heparan-sulfate moieties in health, reproduction, and survival, and represents an in vivo model for comparative analysis of heparin-derived and other antithrombotic molecules.
Biomechanically Induced Gene
iex-1
Inhibits Vascular Smooth Muscle Cell Proliferation and Neointima Formation
Authors: Schulze P. Christian , de Keulenaer Gilles W. , Kassik Kimberly A. , Takahashi Tomosaburo , Chen Zhiping , Simon Daniel I. , Lee Richard T.
Published: November 2003

Mechanotransduction plays a prominent role in vascular pathophysiology but is incompletely understood. In this study, we report the biomechanical induction of the immediate early response gene
iex-1
in vascular smooth muscle cells (SMCs). Mechanical induction of
iex-1
was confirmed by Northern (30-fold induction after 2 hours) and Western (6-fold induction after 24 hours) analyses. Expression of
iex-1
was regulated by mechanical activation of nuclear factor (NF)-κB and abolished by overexpression of IκB in SMCs. The function of
iex-1
in SMCs was explored by gene transfer using adenoviral vectors overexpressing
iex-1
. After 48 hours of 4% cyclic mechanical strain, adenoviral vectors overexpressing
iex-1
–infected cells had lower
3
[H]-thymidine incorporation compared with AdGFP-infected controls (71.3±8.5% versus 180.2±19.4% in controls;
P
<0.001). Overexpression of
iex-1
suppressed mitogenesis induced by platelet-derived growth factor (208.1±108.3% versus 290.0±120.5% in controls;
P
<0.05). This was accompanied by reduced degradation of p27
kip1
, inhibition of Rb hyperphosphorylation, and reduced cell cycle progression. To investigate functional effects of
iex-1
in vivo, we performed carotid artery mechanical injury and endothelial denudation in low-density lipoprotein receptor–deficient mice followed by intraluminal injection of adenoviral vectors (3×10
9
pfu in 50 μL) for overexpression of
iex-1
or
gfp
(control). Vascular overexpression of
iex-1
reduced neointima formation 2 weeks after injury (intima/media ratio, 0.23±0.04 versus 0.5±0.24 in controls;
P
<0.05). Our findings demonstrate that biomechanical strain induces
iex-1
with subsequent antiproliferative effects in SMCs and that selective gene transfer of
iex-1
inhibits the local vascular response after injury. These findings suggest that the induction of
iex-1
represents a novel negative biomechanical feedback mechanism limiting the vascular response to injury.
Role of 14-3-3-Mediated p38 Mitogen-Activated Protein Kinase Inhibition in Cardiac Myocyte Survival
Authors: Zhang Shaosong , Ren Jie , Zhang Cindy E. , Treskov Ilya , Wang Yibin , Muslin Anthony J.
Published: November 2003

14-3-3 family members are dimeric phosphoserine-binding proteins that regulate signal transduction, apoptotic, and checkpoint control pathways. Targeted expression of dominant-negative 14-3-3η (DN-14-3-3) to murine postnatal cardiac tissue potentiates Ask1, c-jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) activation. DN-14-3-3 mice are unable to compensate for pressure overload, which results in increased mortality, dilated cardiomyopathy, and cardiac myocyte apoptosis. To evaluate the relative role of p38 MAPK activity in the DN-14-3-3 phenotype, we inhibited cardiac p38 MAPK activity by pharmacological and genetic methods. Intraperitoneal injection of SB202190, an inhibitor of p38α and p38β MAPK activity, markedly increased the ability of DN-14-3-3 mice to compensate for pressure overload, with decreased mortality. DN-14-3-3 mice were bred with transgenic mice in which dominant-negative p38α (DN-p38α) or dominant-negative p38β (DN-p38β) MAPK expression was targeted to the heart. Compound transgenic DN-14-3-3/DN-p38β mice, and to a lesser extent compound transgenic DN-14-3-3/DN-p38α mice, exhibited reduced mortality and cardiac myocyte apoptosis in response to pressure overload, demonstrating that DN-14-3-3 promotes cardiac apoptosis due to stimulation of p38 MAPK activity.
Using DNA Microarray to Identify Sp1 as a Transcriptional Regulatory Element of Insulin-Like Growth Factor 1 in Cardiac Muscle Cells
Authors: Li Tao , Chen Yung-Hsiang , Liu Tsun-Jui , Jia Jia , Hampson Steven , Shan Yue-Xin , Kibler Dennis , Wang Ping H.
Published: November 2003

High throughput gene expression profiling with DNA microarray provides an opportunity to analyze transcriptional regulation of hundreds or thousands of similarly regulated genes. Transcriptional regulation of gene expression plays an important role in myocardial remodeling. We have studied cardiac muscle gene expression with DNA microarray and used a computational strategy to identify common promoter motifs that respond to insulin-like growth factor 1 (IGF-1) stimulation in cardiac muscle cells. The analysis showed that the Sp1 binding site is a likely target of IGF-1 action. Further experiments with gel shift assay indicated that IGF-1 regulated the Sp1 site in cardiomyocytes, by increasing the abundance of Sp1 and Sp3 proteins. Using firefly luciferase as reporter gene, additional experiments showed that IGF-1 activated the promoter of cyclin D3 and Glut1. Both promoters contain one Sp1 site. The effect of IGF-1 on these two promoters was abolished with siRNA for Sp1. Thus, the transcriptional activation of these two promoters by IGF-1 requires the induction of Sp1 protein. These experiments suggest that the global transcriptional regulatory actions of IGF-1 involve activation of the Sp1 site in cardiac muscle. The computational model we have developed is a prototypical method that may be further developed to identify unique
cis
- and
trans
-acting elements in response to hormonal stimulation during cardiac muscle growth, repair, and remodeling in normal and abnormal cardiac muscle.
Essential Role for Vascular Gelatinase Activity in Relaxin-Induced Renal Vasodilation, Hyperfiltration, and Reduced Myogenic Reactivity of Small Arteries
Authors: Jeyabalan Arundhathi , Novak Jacqueline , Danielson Lee A. , Kerchner Laurie J. , Opett Shannon L. , Conrad Kirk P.
Published: November 2003

During pregnancy, relaxin stimulates nitric oxide (NO)–dependent renal vasodilation, hyperfiltration and reduced myogenic reactivity of small renal arteries via the endothelial ET
B
receptor subtype. Our objective in this study was to elucidate the mechanisms by which relaxin stimulates the endothelial ET
B
receptor/NO vasodilatory pathway. Using chronically instrumented conscious rats, we demonstrated that a specific peptide inhibitor of the gelatinases MMP-2 and −9, cyclic CTTHWGFTLC (cyclic CTT), but not the control peptide, STTHWGFTLS (STT), completely reversed renal vasodilation and hyperfiltration in relaxin-treated rats. Comparable findings were observed with a structurally different and well-established, general antagonist of MMPs, GM6001. In contrast, phosphoramidon, an inhibitor of endothelin-converting enzyme, did not significantly change the renal vasodilatory response to relaxin administration. When small renal arteries were incubated with either of the general MMP inhibitors, GM6001 or TIMP-2 (tissue inhibitor of MMP), or with the specific gelatinase inhibitor, cyclic CTT, the reduced myogenic reactivity of these blood vessels from relaxin-treated nonpregnant and midterm pregnant rats was totally abolished. Moreover, a neutralizing antibody specific for MMP-2 completely abrogated the reduced myogenic reactivity of small renal arteries from relaxin-treated nonpregnant and midterm pregnant rats. In contrast, phosphoramidon did not significantly affect the reduction in myogenic reactivity. Using gelatin zymography, we showed increased pro and active MMP-2 activity in small renal arteries from relaxin-treated nonpregnant and midterm pregnant rats relative to the control animals. Thus, inhibitors of MMPs in general and of gelatinases in particular reverse the renal vascular changes induced by pregnancy or relaxin administration to nonpregnant rats. Finally, the typical reduction in myogenic reactivity of small renal arteries from relaxin-treated nonpregnant rats was absent in ET
B
receptor–deficient rats, despite an increase in vascular MMP-2 activity. These results indicate an essential role for vascular gelatinase, which is in series with, and upstream of, the endothelial ET
B
receptor/NO signaling pathway in the renal vasodilatory response to relaxin and pregnancy.