bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk of Malignancy in Serous Cystic Neoplasms of the Pancreas
Authors: Strobel Oliver , Z’graggen Kaspar , Schmitz-Winnenthal Friedrich H. , Friess Helmut , Kappeler Andreas , Zimmermann Arthur , Uhl Waldemar , Büchler Markus W.
Published: September 2003

Background: In contrast to mucinous cystic neoplasms of the pancreas, which are known to have considerable malignant potential, the serous variant is generally thought to be benign. There are, however, several reports of malignancy in serous cystic neoplasms of the pancreas. Aims: To assess the risk of malignancy of serous cystic tumors of the pancreas and to investigate specific clinical and histological features. Methods: Clinical and pathological characteristics of benign and malignant serous cystic neoplasms of the pancreas were investigated by a review of the literature and documented by a case of a serous cystadenocarcinoma and immunohistochemical analysis of a series of serous cystadenomas. Reviewing the literature prevalence, age and sex distribution of serous cystic neoplasms were analyzed. Results: The prevalence of cancer among serous cystic neoplasms reported since 1989 was 3%. Serous cystadenoma of the pancreas present at an earlier age (61 years) than serous cystadenocarcinoma (66 years; p = 0.056) and are symptomatic in the majority of patients.Pathological examination of the primary tumor was not able to distinguish cystadenoma from cystadenocarcinoma in 38% of cases. In 25% the diagnosis of cancer was established only after growth of metachronous metastases. In the present case, nuclear atypia, papillary structures, proliferation marker Ki-67 and p53 protein were increased in the primary tumor and/or metachronous metastasis. Conclusion: Serous cystic neoplasms of the pancreas do have malignant potential with a risk of malignancy of 3% and should be surgically treated if the operative risk is acceptable. Routine analysis of genetic and proliferation markers may improve diagnosis of malignancy in these tumors.
Major Pathological Mechanisms of Acute Pancreatitis Are Prevented by N-Acetylcysteine
Authors: Sevillano S. , De la Mano A.M. , De Dios I. , Ramudo L. , Manso M.A.
Published: September 2003

Aim: To analyze the capability of N-acetylcysteine (NAC) to prevent major intra-acinar pathogenic mechanisms involved in the development of acute pancreatitis (AP). Methods: AP was induced by pancreatic duct obstruction (PDO) in rats. Some animals received NAC (50 mg/kg) 1 h before and 1 h after PDO. During a 24-hour period of PDO, plasma amylase activity and pancreatic glutathione and malondialdehyde levels were measured. Cytosolic Ca2+ levels and enzyme (amylase and trypsinogen) load in acinar cells were also analyzed by flow cytometry, and histological analysis of the pancreas was performed by electron microscopy. Results: NAC avoided glutathione depletion at early AP stages, thereby preventing pancreatic oxidative damage, as reflected by normal malondialdehyde levels. By limiting oxidative stress, NAC treatment effectively prevented the impairment of Ca2+ homeostasis found in acinar cells from early AP onwards, thus protecting the pancreas from damage. In addition, lower quantities of digestive enzymes were accumulated within acinar cells. This finding, together with the significantly lower hyperamylasemia observed in these animals, suggests that NAC treatment palliates the exocytosis blockade induced by PDO. Conclusion: By preventing oxidative stress at early AP stages, NAC administration prevents other pathological mechanisms of AP from being developed inside acinar cells, thus palliating the severity of disease.
Effects of Dietary Nitrate on Oesophageal Motor Function and Gastro-Oesophageal Acid Exposure in Healthy Volunteers and Reflux Patients
Authors: Bove M. , Lundell L. , Ny L. , Casselbrant A. , Fändriks L. , Pettersson A. , Ruth M.
Published: September 2003

Background/Aims: High concentrations of nitric oxide (NO), derived from dietary nitrite in an acid environment, have been demonstrated in the gastric fundus and in the oesophagus. The aim of this study was to investigate whether luminal NO can influence oesophageal smooth muscle performance, lower oesophageal sphincter (LOS) function or gastric and oesophageal acid exposure. Methods: Eleven healthy volunteers and 9 patients with chronic gastro-oesophageal reflux disease (GORD) received a diet deprived of nitrate/nitrite but supplemented with placebo or potassium nitrate for 4 days in a randomised order. On day 4 in each trial period, manometry was performed including a sleeve sensor registration of the LOS followed by a simultaneous 24-hour intra-gastric and oesophageal pH registration. Results: Nitrate supplementation increased the proportion of effective peristalsis when analysed for the entire study population. No other significant effects of dietary nitrate were found on oesophageal motor variables, on the sphincter resting tone or on the number or duration of transient sphincter relaxations. No effect was found on either gastric acidity or gastro-oesophageal reflux variables. Major reflux symptoms were not influenced by nitrate administration. Conclusion: Dietary nitrate did not significantly affect oesophageal motor or LOS function, gastro-oesophageal acid reflux or reflux symptomatology either in healthy volunteers or in GORD patients.
Venous thromboembolism among patients with advanced lung cancer randomized to prinomastat or placebo, plus chemotherapy
Authors: Ruiz Rolando , Behrendt Carolyn
Published: September 2003

Two clinical trials have suggested that the combination of vascular endothelial growth factor inhibitor with chemotherapy is associated with venous thromboembolism (VTE). This retrospective cohort study investigates whether a similar association exists when matrix metalloproteinase inhibitor (prinomastat) is combined with chemotherapy.

Patients (n=1,023) with stage IIIB, IV, or recurrent non-small cell lung cancer (NSCLC) were followed during 2 randomized, double-blind trials of prinomastat versus placebo orally bid, plus gemcitabine/cisplatin (GC) or paclitaxel/carboplatin (PC). VTE included deep venous thrombosis (DVT) or pulmonary embolism (PE) confirmed by imaging or autopsy. Risks identified in univariate analysis (incidence densities compared by t test) were confirmed in multivariate analysis (proportional hazards model).

During 7,500.3 patient-months, 58 VTE (31 PE, 27 isolated DVT) were confirmed in 54 patients. On univariate analysis, VTE was associated with central venous catheter placed within 3 months,15 mg prinomastat plus GC, and to a lesser extent, 15 mg prinomastat plus PC, baseline performance status, and histologic type. VTE incidence was not increased by 15 mg prinomastat alone (post-discontinuation of chemotherapy), by chemotherapy plus placebo, or by 5 or 10 mg prinomastat plus chemotherapy. On multivariate analysis, VTE hazards (95% confidence interval) were 5.69 (2.61, 12.40) with recently placed central catheter, 2.78 (1.42, 5.43) with 15 mg prinomastat plus GC, and 2.06 (0.98, 4.31) with 15 mg prinomastat plus PC; performance status and histology were nonsignificant.

We can conclude that combined treatment with 15 mg prinomastat plus chemotherapy approximately doubles the hazard of VTE among patients with advanced NSCLC.

Research support: Pfizer Inc
Mechanisms of the priming effect of low doses of lipopolysaccharides on leukocyte-dependent platelet aggregation in whole blood
Authors: Montrucchio Giuseppe , Bosco Ornella , Sorbo Lorenzo , Pecetto Paolo , Lupia Enrico , Goffi Alberto , Omedè Paola , Emanuelli Giorgio , Camussi Giovanni
Published: September 2003

Several studies focused on the ability of bacterial lipopolysaccharides (LPS) in triggering platelet and/or leukocyte activation. The aim of this study was to investigate the molecular mechanisms involved in the aggregation of platelets and in their interaction with leukocytes in whole blood after stimulation with low doses of LPS.

LPS did not directly induce platelet aggregation in whole blood, but they primed the aggregation of platelets induced by epinephrine, adenosine diphosphate and arachidonic acid. As shown by cytofluorimetry, platelets neither bind FITC-LPS, nor express the LPS-receptors CD14 and toll-like receptor 4 (TLR4). On the contrary, LPS primed monocytes and to a lesser extent polymorphonuclear neutrophils to adhere to platelets. Both platelet-leukocyte interaction and platelet aggregation in whole blood were inhibited by blockade of CD14 and TLR4. Moreover, the interaction between platelets and leukocytes was inhibited by P-selectin, and by blockade of PAF and reactive oxygen species, suggesting a role of P-selectin and of leukocyte-derived mediators.

In conclusion, these results elucidate the mechanisms leading to platelet activation and interaction with leukocytes triggered by LPS. They suggest that the activation of platelets by LPS is mainly dependent on leukocytes and especially monocytes as a result of CD14 and TLR4 engagement. Moreover, we found that leukocyte-platelet interaction was triggered by the synthesis of PAF and the generation of oxygen radicals that induced upregulation of surface expression of P-selectin.
Studies of α-granule proteins in cultured human megakaryocytes
Authors: Veljkovic Dragoslava , Cramer Elisabeth , Alimardani Gulie , Fichelson Serge , Massé Jean-Marc , Hayward Catherine
Published: September 2003

α-Granule protein storage is important for producing platelets with normal haemostatic function. The low to undetectable levels of several megakaryocyte-synthesized α-granule proteins in normal plasma suggest megakaryocytes are important to sequester these proteins in vivo. α-Granule protein storage in vitrohas been studied using other cell types, with differences observed in how some proteins are processed compared to platelets. Human megakaryocytes, cultured from cord blood CD34+cells and grown in serum-free media containing thrombopoietin, were investigated to determine if they could be used as a model for studying normal α-granule protein processing and storage. ELISA indicated that cultured megakaryocytes contained the α-granule proteins multimerin, von Willebrand factor, thrombospondin-1, β-thromboglobulin and platelet factor 4, but no detectable fibrinogen and factor V. A significant proportion of the α-granule protein in megakaryocyte cultures was contained within the cells (averages: 41 – 71 %), consistent with storage. Detailed analyses of multimerin and von Willebrand factor confirmed that α-granule proteins were processed to mature forms and were predominantly located in the α-granules of cultured megakaryocytes. Thrombopoietin-stimulated cultured megakaryocytes provide a useful model for studying α-granule protein processing and storage.
Plasminogen activator inhibitor-1 and outcome after femoropopliteal angioplasty: analysis of genotype and plasma levels
Authors: Schillinger Martin , Exner Markus , Sabeti Schila , Mannhalter Christine , Minar Erich , Wagner Oswald , Mlekusch Wolfgang
Published: September 2003

Plasminogen activator inhibitor-1 (PAI-1) is suggested to be involved in the pathophysiology of early thrombosis and late restenosis after percutaneous transluminal angioplasty (PTA). The role of the PAI-1 promoter genotype in this context is indeterminate. We investigated the association of the (4G/5G) polymorphism at nucleotide position (–675) in the PAI-1 gene promoter, PAI-1 plasma levels, and postangioplasty outcome after femoropopliteal PTA.

We studied 251 consecutive patients who underwent femoropopliteal PTA. In a subgroup of 86 patients PAI-1 plasma levels at baseline,8,24 and 48 hours postintervention were measured and correlated to the genotype. Patients were followed for early thrombosis and the late restenosis (≥50%) within 12 months. Multivariate Cox proportional hazards analysis was performed to assess the association between the PAI-1 genotype and PTA failure.

Results show that the PAI-1 genotype was neither associated with PAI-1 plasma levels (p=0.40) nor the change of PAI-1 from baseline to 8 (p=0.39), 24 (p=0.86) and 48 hours (p=0.89). Three out of 35 homozygous (4G/4G) patients (9%) had early thrombotic reocclusions, compared to two out of 153 heterozygous (4G/5G) patients (1%) and none of the 63 homozygous (5G/5G) patients (p=0.007). Restenosis after median 5 months (interquartile range 3 to 9) was found in 117 patients (42%), without significant association between the PAI-1 genotype and late postangioplasty failure (Log Rank p=0.95).

We can conclude that carriers of the 4G allele exhibited a higher frequency of early thrombotic reocclusions after percutaneous angioplasty. However, the PAI-1 gene promoter polymorphism (4G/5G) was not associated with PAI-1 plasma levels or late postangioplasty restenosis.
The ACE D/D genotype is protective against the development of idiopathic deep vein thrombosis and pulmonary embolism
Authors: Rodger Marc , Forgie Melissa , Langlois Nicole , Armstrong Linlea , Carson Nancy , Jaffey James , Wells Philip
Published: September 2003

The deletion/deletion (D/D) genotype of the angiotensin converting enzyme (ACE) has been purported to be a risk for postoperative thrombosis. This D/D genotype has not been evaluated as a risk factor for idiopathic venous thromboembolism (VTE).

The primary objective of the present study was to determine whether the D/D genotype of ACE is independently associated with the occurrence of idiopathic venous thromboembolic disease.

We prospectively enrolled consecutive patients with at least one objectively confirmed idiopathic VTE. Friends of cases were recruited as controls and matched to cases by sex, ethnicity, and age. Patients were tested for the ACE I/D polymorphism in addition to factor V Leiden, prothrombin G20210A, and factor VIII levels.

Three hundred cases and 300 controls were enrolled; 97% were Caucasian. There were 148 females and 152 males in each group with a mean age of 56.21 years (SD=15.33). The ACE D/D genotype was present in 25.3% of cases and 32.4% of controls for an adjusted odds ratio of 0.66 (95% CI = 0.433 to 0.997). We can conclude that the ACE D/D genotype is protective against idiopathic venous thromboembolism.
Thrombophilic mutations in high-risk atrial fibrillation patients: high prevalence of prothrombin gene G20210A polymorphism and lack of correlation with thromboembolism
Authors: Poli Daniela , Antonucci Emilia , Cecchi Emanuele , Betti Irene , Valdrè Lelia , Mugnaini Cristina , Alterini Bruno , Morettini Alessandro , Nozzoli Carlo , Abbate Rosanna , Franco Gensini Gian , Prisco Domenico
Published: September 2003

Atrial fibrillation (AF) is a common arrhythmia that results in a high risk of cerebral and peripheral embolism. Factor V Leiden and factor II G20210A variant are two leading conditions for venous thrombosis. The aim of our study was to find out whether these two common prothrombotic mutations play a role in the occurrence of embolic events in AF patients. We investigated 336 non-valvular AF patients and 336 healthy control subjects. Factor II G20210A variant was found in 24/336 patients (7.14%) and in 11/336 of control subjects (3.3%). At a multivariate analysis, factor II G20210A variant was independently associated to AF (OR 2.4 95% CI 1.1-5.2; p<0.05). No significant difference was observed in the prevalence of factor V Leiden in the two groups investigated [6/304 (2.0%) in patients vs 13/336 (3.9%) in controls (p=0.24)]. AF patients were separately analyzed in relation to the occurrence or absence of a cerebral or peripheral embolic event (200 with and 136 without embolic event). The prevalence of the two mutations among AF patients with and without an embolic event was similar [factor II G20210A polymorphism (7% and 7.3% respectively) and factor V Leiden (1.2% and 2.9%, respectively)]. No differences were found in relation to the type of embolic event. Our results suggest a possible relationship between the presence of prothrombin gene variant and AF per se.
Pharmacokinetics and anticoagulant properties of the factor VIIa-tissue factor inhibitor recombinant Nematode Anticoagulant Protein c2 following subcutaneous administration in man
Authors: Bradbury Annette , Lopez-Kinninger Lily , Colón Sonia , Bergum Peter , Maki Steven , Rote William , Vlasuk George
Published: September 2003

Recombinant Nematode Anticoagulant Protein c2 (rNAPc2) is a potent (Ki=10 pM), inhibitor of the factor VIIa/tissue factor (fVIIa/TF) complex that requires the prerequisite binding to zymogen or activated factor X (fX). In two double blind, placebo-controlled, sequential dose-escalation phase I studies, rNAPc2 was found to be safe and well tolerated following single and repeat subcutaneous administrations in healthy human male volunteers at doses ranging from 0.3 to 5 µg/kg. There was a dose-dependent elevation of the prothrombin time reaching almost 4-fold above the baseline value in the highest dose group that directly correlated with rNAPc2 plasma concentration. In contrast, there was little or no effect on the activated partial thromboplastin time, thrombin time or template bleeding time. The pharmacokinetic behavior of rNAPc2 revealed a dose-independent and prolonged elimination half-life (t1/2β) with a mean of >50 hours. A high affinity interaction between rNAPc2 and plasma fX was shown to be essential for the prolonged t1/2β in man using crossed immunoelectrophoresis and was confirmed by exploiting the considerably weaker interaction between rNAPc2 and bovine fX which resulted in an attenuated t1/2β of ~1.5 hours in calves. The accumulated data suggests that rNAPc2 is safe and well tolerated following repeat subcutaneous administrations at doses up to 5 µg/kg in healthy volunteers. In addition, the in vivofate of rNAPc2 in man appears to be governed by its high affinity interaction with circulating fX. This data supports the continued development of this novel anticoagulant for the prevention and treatment of acute thrombotic disorders.
Genetics, Clinical Phenotype, and Molecular Cell Biology of Autosomal Recessive Hypercholesterolemia
Authors: Soutar Anne K. , Naoumova Rossitza P. , Traub Linton M.
Published: September 2003

The recent characterization of a rare genetic defect causing autosomal recessive hypercholesterolemia (ARH) has provided new insights into the underlying mechanism of clathrin-mediated internalization of the LDL receptor. Mutations in
ARH
on chromosome 1p35-36.1 prevent normal internalization of the LDL receptor by cultured lymphocytes and monocyte-derived macrophages but not by skin fibroblasts. In affected cells, LDL receptor protein accumulates at the cell surface; this also occurs in the livers of recombinant mice lacking
ARH
, thereby providing an explanation for the failure of clearance of LDL from the plasma in subjects lacking ARH. The ≈50 known affected individuals are mostly of Sardinian or Middle Eastern origin. The clinical phenotype of ARH is similar to that of classic homozygous familial hypercholesterolemia caused by defects in the LDL receptor gene, but it is more variable, generally less severe, and more responsive to lipid-lowering therapy. Structural features of the ARH protein and its capacity to interact simultaneously with the internalization sequence of the LDL receptor, plasma membrane phospholipids, and the clathrin endocytic machinery suggest how ARH can play a pivotal role in gathering the LDL receptor into forming endocytic carrier vesicles.
3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Inhibitors Decrease Fas Ligand Expression and Cytotoxicity in Activated Human T Lymphocytes
Authors: Blanco-Colio Luis Miguel , Muñoz-García Begoña , Martín-Ventura Jose Luis , Lorz Corina , Díaz Cristina , Hernández Gonzalo , Egido Jesús
Published: September 2003

Background—

HMG-CoA reductase inhibitors reduce cardiovascular mortality, although the mechanisms of action have not been completely elucidated. The presence of T cells and apoptotic cells in atherosclerotic plaques is well established, the reduction of cellular content being a marker of their vulnerability. One of the main mechanisms of cell death activation is the Fas-Fas ligand (FasL) system.

Methods and Results—

We studied whether HMG-CoA reductase inhibitors can regulate FasL expression and cytotoxicity in human T cells (Jurkat cells). Activation of Jurkat cells with phorbol esters and ionomycin increased FasL expression, an effect prevented by atorvastatin or simvastatin. Mevalonate and geranylgeranylpyrophosphate but not farnesylpyrophosphate prevented the effect of atorvastatin, indicating that protein geranylation was involved in FasL expression. The C3 exotoxin, which selectively inactivates Rho proteins, also decreased FasL expression on T cells. Overexpression of constitutively active RhoA increased FasL expression in Jurkat cells, and dominant-negative RhoA decreased FasL expression in activated cells, indicating that RhoA is implicated in FasL expression. Atorvastatin also decreased cytotoxic activity of activated Jurkat cells on FasL-sensitive cells. Finally, atorvastatin treatment reduced FasL expression in peripheral blood mononuclear cells and human carotid atherosclerotic plaques.

Conclusions—

Atorvastatin regulates FasL expression in T cells, probably because of the inhibition of RhoA prenylation. These results provide novel information by which atorvastatin may regulate the cytotoxic activity of T cells and the number of cells in the atherosclerotic plaque.
Attenuation of Nitrate Tolerance and Oxidative Stress by an Angiotensin II Receptor Blocker in Patients With Coronary Spastic Angina
Authors: Hirai Nobutaka , Kawano Hiroaki , Yasue Hirofumi , Shimomura Hideki , Miyamoto Shinzo , Soejima Hirofumi , Kajiwara Ichiro , Sakamoto Tomohiro , Yoshimura Michihiro , Nakamura Hajime , Yodoi Junji , Ogawa Hisao
Published: September 2003

Background—

Nitrates are widely used to treat coronary artery disease, but their therapeutic value is compromised by the rapid development of tolerance. Recently, the renin-angiotensin system has been suggested to play an important role in the development of nitrate tolerance.

Methods and Results—

Sixty-four patients with coronary spastic angina were investigated to clarify the effect of angiotensin II type 1 receptor blocker (ARB) therapy on nitrate tolerance. Transdermal nitroglycerin (10 mg/d) and an ARB (candesartan, 8 mg/d) were administered to 21 patients (GTN+ARB group) for 3 days, whereas transdermal nitroglycerin and placebo were administered to 19 patients (GTN group). Another 18 patients were treated with placebo skin patches and placebo tablets for 3 days (control group). The brachial artery response to incremental doses of intravenous nitroglycerin (0.01, 0.1, and 1.0 μg/kg) was measured by ultrasound before and after transdermal nitroglycerin therapy. Before treatment, the arterial diameter was increased by nitroglycerin injection in each group. After treatment, the increase of arterial diameter was significantly suppressed in the GTN group but not in the control or GTN+ARB groups. The plasma level of thioredoxin (a marker of oxidative stress) was increased in the GTN group after treatment (
P
<0.01) but not in the control or GTN+ARB groups.

Conclusions—

An ARB suppressed the development of nitrate tolerance during transdermal nitroglycerin therapy. These results suggest that increased oxidative stress induced by activation of angiotensin II may play an important role in the development of nitrate tolerance.
Connective Tissue Growth Factor Is a Mediator of Angiotensin II–Induced Fibrosis
Authors: Rupérez Mónica , Lorenzo Óscar , Blanco-Colio Luis Miguel , Esteban Vanesa , Egido Jesús , Ruiz-Ortega Marta
Published: September 2003

Background—

Angiotensin II (Ang II) participates in the development of fibrosis during vascular damage. Connective tissue growth factor (CTGF) is a novel fibrotic mediator. However, the potential link between CTGF and Ang II has not been investigated.

Methods and Results—

In vivo Ang II effects were studied by systemic infusion into normal rats to evaluate CTGF and extracellular matrix protein (ECM) expression by immunohistochemistry. In aorta of Ang II–infused rats, CTGF staining was markedly increased and ECM overexpression was observed. An AT
1
antagonist diminished CTGF and ECM. In growth-arrested vascular smooth muscle cells, Ang II induced CTGF mRNA expression after 1 hour, remained elevated up to 24 hours, and increased CTGF protein production, which was increased up to 72 hours. The AT
1
antagonist blocked Ang II–induced CTGF gene and protein expression. Early CTGF upregulation is independent of new protein synthesis. Several intracellular signals elicited by Ang II are involved in CTGF synthesis, including protein kinase C activation, reactive oxygen species, and transforming growth factor-β endogenous production. Incubation with a CTGF antisense oligonucleotide decreased CTGF and fibronectin upregulation caused by Ang II.

Conclusions—

Our results show that Ang II, via AT
1
, increases CTGF in vascular cells both in vivo and in vitro. This novel finding suggests that CTGF may be a mediator of the profibrogenic effects of Ang II in vascular diseases.
Chronic Physiological Shear Stress Inhibits Tumor Necrosis Factor–Induced Proinflammatory Responses in Rabbit Aorta Perfused Ex Vivo
Authors: Yamawaki Hideyuki , Lehoux Stephanie , Berk Bradford C.
Published: September 2003

Background—

Regions in the vasculature exposed to steady laminar flow have a lower likelihood for atherosclerosis than regions exposed to disturbed flow with low shear stress. We previously found that laminar flow of short duration inhibited tumor necrosis factor (TNF)-α–mediated proinflammatory signaling in cultured endothelial cells (ECs). However, mechanisms responsible for the atheroprotective effects of physiological shear stress remain undefined. Therefore, we examined the effects of chronic shear stress on TNF-α–induced inflammatory responses using an ex vivo perfusion organ culture system.

Methods and Results—

Rabbit aortas were exposed to low or normal shear stress (0.4 or 12 dyne/cm
2
) at a constant pressure for 24 to 26 hours. EC and vascular smooth muscle cell (VSMC) proteins were selectively purified. After exposure to low shear stress, TNF-α (50 ng/mL, 6 hours) specifically stimulated vascular cell adhesion molecule (VCAM)-1 expression in ECs but not VSMCs. TNF-α–stimulated VCAM expression was inhibited significantly by preexposure to normal shear stress. Normal shear stress inhibited TNF (15 minutes) activation of mitogen-activated protein (MAP) kinases (c-Jun NH
2
-terminal kinase [JNK], p38, extracellular signal–regulated kinase [ERK]) in ECs. Specific pharmacological inhibitors of JNK and p38 but not ERK significantly inhibited TNF-induced VCAM expression. Normal shear stress prevented the association of TNF receptor (TNFR)-1 with TNFR-associated factor (TRAF)-2. There was no effect of low or normal shear stress on TNF-α–induced nuclear factor-κB activation. A nitric oxide synthesis inhibitor,
N
G
-nitro-
l
-arginine methyl ester, did not reverse the inhibitory effects of shear stress on VCAM expression.

Conclusions—

These results suggest that physiological shear stress is antiinflammatory by specifically inhibiting MAP kinase signaling and inhibiting TRAF-2 interaction with TNFR-1.
Reverse Remodeling of Sinus Node Function After Catheter Ablation of Atrial Fibrillation in Patients With Prolonged Sinus Pauses
Authors: Hocini Mélèze , Sanders Prashanthan , Deisenhofer Isabel , Jaïs Pierre , Hsu Li-Fern , Scavée Christophe , Weerasoriya Rukshen , Raybaud Florence , Macle Laurent , Shah Dipen C. , Garrigue Stéphane , Le Metayer Philippe , Clémenty Jacques , Haïssaguerre Michel
Published: September 2003

Background—

Symptomatic prolonged sinus pauses on termination of atrial fibrillation (AF) are an indication for pacemaker implantation. We evaluated sinus node function and clinical outcome in patients with prolonged sinus pauses on termination of arrhythmia who underwent ablation of paroxysmal AF.

Methods and Results—

Twenty patients with paroxysmal AF and prolonged sinus pauses (≥3 seconds) on termination of AF underwent ablation between May 1995 and November 2002. Patients with sinus pauses independent of episodes of AF were excluded from the analysis. The procedure included pulmonary vein and linear atrial ablation. After ablation, sinus node function was assessed during the first week and at 1, 3, and 6 months, by 24-hour ambulatory monitoring to determine the mean heart rate and heart rate range, and by exercise testing to determine the maximal heart rate. Corrected sinus node recovery time was determined at the completion of ablation and at 24.0±11.3 months at 600 and 400 ms. After AF ablation, there was a significant improvement of sinus node function, with an increase in the mean heart rate (
P
=0.001), maximal heart rate (
P
<0.0001), and heart rate range (
P
<0.0001). The corrected sinus node recovery time decreased in all patients evaluated at 600 ms (
P
=0.016) and 400 ms (
P
=0.019). At 26.0±17.6 months, 18 patients (85%) had no recurrence of AF (in the absence of medication), with no symptoms attributable to bradycardia or sinus pauses on ambulatory monitoring. Two patients had infrequent episodes of AF, 1 requiring pacemaker implantation.

Conclusion—

Prolonged sinus pauses after paroxysms of AF may result from depression of sinus node function that can be eliminated by curative ablation of AF. This is accompanied by improvement in parameters of sinus node function, suggesting reverse remodeling of the sinus node.
Cholesterol Reduction With Atorvastatin Improves Walking Distance in Patients With Peripheral Arterial Disease
Authors: Mohler Emile R. , Hiatt William R. , Creager Mark A.
Published: September 2003

Background—

Cholesterol modification reduces cardiovascular events in patients with atherosclerosis, including those with peripheral arterial disease. The purpose of this study was to determine whether cholesterol lowering with atorvastatin improves walking performance in patients with intermittent claudication.

Methods and Results—

This randomized, double-blind, parallel-design study included 354 persons with claudication attributable to peripheral arterial disease. Patients were treated with placebo, atorvastatin (10 mg per day), or atorvastatin (80 mg per day) for 12 months. The outcome measures included change in treadmill exercise time and patient-reported measures of physical activity and quality of life based on questionnaires. Maximal walking time after 12 months of treatment with atorvastatin did not change significantly. However, there was improvement in pain-free walking time after 12 months of treatment for the 80-mg (
P
=0.025) group compared with placebo. A physical activity questionnaire demonstrated improvement in ambulatory ability for the 10- and 80-mg groups (
P
=0.011), whereas 2 quality of life instruments, the Walking Impairment Questionnaire and Short Form 36 Questionnaire, did not show significant change.

Conclusions—

Atorvastatin improves pain-free walking distance and community-based physical activity in patients with intermittent claudication. When treated with atorvastatin, patients with peripheral arterial disease may experience improvement in symptoms to complement the anticipated reduction in cardiovascular events reported in other studies of statins.
Prospective Assessment of Late Conduction Recurrence Across Radiofrequency Lesions Producing Electrical Disconnection at the Pulmonary Vein Ostium in Patients With Atrial Fibrillation
Authors: Cappato Riccardo , Negroni Silvia , Pecora Domenico , Bentivegna Stefano , Lupo Pier Paolo , Carolei Adriana , Esposito Cristina , Furlanello Francesco , De Ambroggi Luigi
Published: September 2003

Background—

In patients with atrial fibrillation (AF) undergoing radiofrequency (RF) electrical disconnection of multiple pulmonary veins (PVs), the incidence of late conduction recurrences has not been systematically determined.

Methods and Results—

Using a prospectively designed, multistep approach, we aimed at assessing the correlation between acute achievement and chronic maintenance of electrical conduction block across RF lesions disconnecting the distal tract of the PV in 43 patients (52.3±8.2 years) with AF. Forty-one left superior (LS), 42 right superior (RS), 25 left inferior (LI), and 9 right inferior (RI) PVs were targeted during 108 EP procedures (2.6±0.5 per patient). Seventeen patients underwent 2 procedures, 23 patients underwent 3 procedures, and 3 patients underwent 4 procedures. During the first attempt, electrical disconnection was achieved in 112 PVs (95.7%). During a next procedure (time interval, 4.6±1.9 months), conduction recurrence was observed in 32 of 39 LSPVs (82.1%), 29 of 40 RSPVs (72.5%), 20 of 24 LIPVs (83.3%), and 7 of 9 RIPV (77.8%). After reablation at gap sites, a later procedure (time interval, 5.1±2.4 months) revealed a second recurrence in 13 of 22 LSPVs (59.1%) and 14 of 19 RSPVs (73.7%).

Conclusions—

Conduction recurrence across disconnecting RF lesions can be observed in ≈80% of cases 4 months after ablation. After reablation, similar recurrence rates are observed 5 months later. This high rate of late conduction recurrence may contribute significantly to AF recurrence in patients undergoing catheter ablation aiming at disconnection of multiple PVs.
Novel Role for the Potent Endogenous Inotrope Apelin in Human Cardiac Dysfunction
Authors: Chen Mary M. , Ashley Euan A. , Deng David X.F. , Tsalenko Anya , Deng Alicia , Tabibiazar Raymond , Ben-Dor Amir , Fenster Brett , Yang Eugene , King Jennifer Y. , Fowler Michael , Robbins Robert , Johnson Frances L. , Bruhn Laurakay , McDonagh Theresa , Dargie Henry , Yakhini Zohar , Tsao Philip S. , Quertermous Thomas
Published: September 2003

Background—

Apelin is among the most potent stimulators of cardiac contractility known. However, no physiological or pathological role for apelin–angiotensin receptor-like 1 (APJ) signaling has ever been described.

Methods and Results—

We performed transcriptional profiling using a spotted cDNA microarray with 12 814 unique clones on paired samples of left ventricle obtained before and after placement of a left ventricular assist device in 11 patients. The significance analysis of microarrays and a novel rank consistency score designed to exploit the paired structure of the data confirmed that natriuretic peptides were among the most significantly downregulated genes after offloading. The most significantly upregulated gene was the G-protein–coupled receptor APJ, the specific receptor for apelin. We demonstrate here using immunoassay and immunohistochemical techniques that apelin is localized primarily in the endothelium of the coronary arteries and is found at a higher concentration in cardiac tissue after mechanical offloading. These findings imply an important paracrine signaling pathway in the heart. We additionally extend the clinical significance of this work by reporting for the first time circulating human apelin levels and demonstrating increases in the plasma level of apelin in patients with left ventricular dysfunction.

Conclusions—

The apelin-APJ signaling pathway emerges as an important novel mediator of cardiovascular control.
First Evidence That Bone Marrow Cells Contribute to the Construction of Tissue-Engineered Vascular Autografts In Vivo
Authors: Matsumura Goki , Miyagawa-Tomita Sachiko , Shin’oka Toshiharu , Ikada Yoshito , Kurosawa Hiromi
Published: September 2003

Background—

Materials commonly used to repair complex cardiac defects lack growth potential and have other unwanted side effects. We designed and tested a bone marrow cell (BMC)–seeded biodegradable scaffold that avoids these problems.

Methods and Results—

To demonstrate the contribution of the BMCs to histogenesis, we labeled them with green fluorescence, seeded them onto scaffolds, and implanted them in the inferior vena cava of dogs. The implanted grafts were analyzed immunohistochemically at 3 hours and subsequently at 2, 4, and 8 weeks after implantation using antibodies against endothelial cell lineage markers, endothelium, and smooth muscle cells. There was no stenosis or obstruction caused by the tissue-engineered vascular autografts (TEVAs) implanted into the dogs. Immunohistochemically, the seeded BMCs expressing endothelial cell lineage markers, such as CD34, CD31, Flk-1, and Tie-2, adhered to the scaffold. This was followed by proliferation and differentiation, resulting in expression of endothelial cells markers, such as CD146, factor VIII, and CD31, and smooth muscle cell markers, such as α-smooth muscle cell actin, SMemb, SM1, and SM2. Vascular endothelial growth factor and angiopoietin-1 were also produced by cells in TEVAs.

Conclusions—

These results provide direct evidence that the use of BMCs enables the establishment of TEVAs. These TEVAs are useful for cardiovascular surgery in humans and especially in children, who require biocompatible materials with growth potential, which might reduce the instance of complications caused by incompatible materials and lead to a reduced likelihood of further surgery.
Salt Appetite and the Renin-Angiotensin System
Authors: Rigatto Katya , Puryear Robert , Bernatova Iveta , Morris Mariana
Published: September 2003

To explore the role of oxytocin in the regulation of salt appetite and blood pressure, we conducted studies in oxytocin gene–knockout mice and determined (1) blood pressure and heart rate during day and night periods, (2) salt appetite after iso-osmotic volume depletion, and (3) salt appetite and blood pressure after central injection of angiotensin II. Long-term arterial catheters were inserted, and blood pressure and heart rate were recorded for 24 hours. There was a modest decrease in blood pressure and heart rate in knockout mice. Salt appetite was measured with a 2- bottle choice (water and 2% NaCl), with measurement of licking activity. Mice were injected subcutaneously with 30% polyethylene glycol (0.5 mL), and voluntary intakes were measured for 24 hours. Knockout mice consumed 3 times the amount of NaCl than did controls, 276±77 vs 90±38 licks/24 h (
P
<0.05). Water consumption was similar between groups. Angiotensin II (5, 50, and 200 ng/3 μL) injected intracerebroventricularly produced dose-related increases in intake, with no differences between the groups. The 50-ng dose of angiotensin II elicited salt and water intakes of 151±43 vs 160±33 licks and 250±53 vs and 200±51 licks, respectively (control vs knockout). The pressor response to angiotensin II was not different between the groups. Results suggest that oxytocin plays a role in the regulation of blood pressure and salt appetite, specifically as mediated by volume receptors, and that the renin-angiotensin system is not involved in these changes.
Angiotensin AT
2
Receptors Directly Stimulate Renal Nitric Oxide in Bradykinin B
2
-Receptor–Null Mice
Authors: Abadir Peter M. , Carey Robert M. , Siragy Helmy M.
Published: September 2003

Both bradykinin B
2
and angiotensin II type 2 (AT
2
) receptors are known to stimulate renal production of nitric oxide (NO). To evaluate the individual contributions of AT
2
and B
2
receptors to renal NO production, we monitored renal interstitial, stable NO metabolites and cGMP by a microdialysis technique in conscious, bradykinin B
2
–null and wild-type mice (n=8 in each group) during low sodium intake alone or with the angiotensin AT
1
or AT
2
receptor blockers, valsartan (0.5 μg/min) or PD123319 (0.15 μg/min), or both. During normal salt intake, renal interstitial fluid NO and cGMP levels in B
2
-null mice were not different from those of wild-type mice. Low sodium intake increased NO and cGMP in wild-type mice but not in B
2
-null mice. Valsartan increased NO and cGMP in both wild-type and B
2
-null mice but to a significantly greater degree in the wild-type than in B
2
-null mice. PD123319 decreased NO and cGMP in both wild-type and B
2
-null mice. Combined valsartan and PD123319 decreased NO and cGMP in both wild-type and B
2
-null mice, but there was no significant difference during combined treatment from their levels after administration of PD123319 alone. Our results indicate that during ingestion of a low-salt diet, production of NO is mediated mainly via the AT
2
-B
2
receptor cascade. Blockade of the AT
1
receptor enhances the production of NO via the AT
2
receptor in both wild-type and B
2
-null mice. We conclude that NO can be produced by 2 alternative pathways: directly through the AT
2
receptor or indirectly from AT
2
receptor stimulation of bradykinin via the B
2
receptor.
Measures of Obesity Are Associated With Vascular Stiffness in Young and Older Adults
Authors: Wildman Rachel P. , Mackey Rachel H. , Bostom Andrew , Thompson Trina , Sutton-Tyrrell Kim
Published: September 2003

Obesity has reached epidemic levels and carries a risk for cardiovascular disease. Obesity’s effects on the vascular systems of young adults and African Americans have not been well characterized. The aim of this study was to assess the association between measures of obesity and aortic stiffness in 186 young adults (20 to 40 years, 50% African American) and 177 older adults (41 to 70 years, 33% African American). Aortic stiffness was measured by aortic pulse-wave velocity. The median pulse-wave velocity value was 468 cm/s for young adults and 627 cm/s for older adults (
P
<0.001). Higher body weight, body mass index, waist and hip circumferences, and waist-hip ratio were strongly correlated with higher pulse-wave velocity, independent of age, systolic blood pressure, race, and sex overall and among both age groups (
P
<0.01 for all). Even among the 20- to 30-year-olds, obese individuals (body mass index>30) had a mean pulse-wave velocity value 47 cm/s higher than did nonobese individuals (
P
<0.001). Obesity measures were among the strongest independent predictors of pulse-wave velocity overall and for both age groups. Results were consistent by race. In conclusion, excess body weight is associated with higher aortic stiffness in whites and African Americans as young as 20 to 30 years. The strength of the association, the early age at which it appears, and the prevalence of obesity among the young warn of substantially increased cardiovascular disease incidence as this cohort ages.
14,15-Epoxyeicosa-5(Z)-Enoic-mSI
Authors: Gauthier Kathryn M. , Jagadeesh Setti G. , Falck John R. , Campbell William B.
Published: September 2003

Endothelium-dependent hyperpolarizations and relaxation of vascular smooth muscle induced by acetylcholine and bradykinin are mediated by endothelium-derived hyperpolarizing factors (EDHFs). In bovine coronary arteries, arachidonic acid metabolites, epoxyeicosatrienoic acids (EETs), function as EDHFs. The 14,15-EET analog 14,15-epoxyeicosa-5(Z)-enoic-methylsulfonylimide (14,15-EEZE-mSI) was synthesized and tested for agonist and antagonist activity. In U46619-preconstricted bovine coronary arterial rings, 14,15-, 11,12-, 8,9-, and 5,6-EET induced maximal concentration-related relaxation averaging 75% to 87% at 10 μmol/L, whereas, 14,15-EEZE-mSI induced maximal relaxation averaging only 7%. 14,15-EEZE-mSI (10 μmol/L) preincubation inhibited relaxation to 14,15- and 5,6- EET but not 11,12- or 8,9- EET. 14,15-EEZE-mSI also inhibited indomethacin-resistant relaxation to arachidonic acid and indomethacin-resistant and
l
-nitroarginine-resistant relaxation to bradykinin and methacholine. It did not alter the relaxation to sodium nitroprusside, iloprost, or the K
+
channel openers bimakalim or NS1619. In cell-attached patches of isolated bovine coronary arterial smooth muscle cells, 14,15-EEZE-mSI (100 nmol/L) blocked the 14,15-EET–induced (100 nmol/L) activation of large-conductance, calcium-activated K
+
channels. Mass spectrometric analysis of rat renal cortical microsomes incubated with arachidonic acid showed that 14,15-EEZE-mSI (10 μmol/L) increased EET concentrations while decreasing the concentrations of the corresponding dihydroxyeicosatrienoic acids. Therefore, 14,15-EEZE-mSI inhibits relaxation to 5,6- and 14,15- EET and the K
+
channel activation by 14,15-EET. It also inhibits the EDHF component of bradykinin-induced, methacholine-induced, and arachidonic acid–induced relaxation. These results suggest that 14,15- or 5,6 -EET act as an EDHF in bovine coronary arteries.
Hypoxia-Inducible Factor-1 Mediates Activation of Cultured Vascular Endothelial Cells by Inducing Multiple Angiogenic Factors
Authors: Yamakawa Midori , Liu Louis X. , Date Taro , Belanger Adam J. , Vincent Karen A. , Akita Geoffrey Y. , Kuriyama Takayuki , Cheng Seng H. , Gregory Richard J. , Jiang Canwen
Published: September 2003

Hypoxia-inducible factor-1 (HIF-1) mediates transcriptional activation of vascular endothelial growth factor (VEGF) and other hypoxia-responsive genes. Transgenic expression of a constitutively stable HIF-1α mutant increases the number of vascular vessels without vascular leakage, tissue edema, or inflammation. This study aimed to investigate the molecular basis by which HIF-1 mediates the angiogenic response to hypoxia. In primary human endothelial cells, hypoxia, desferrioxamine, or infection with Ad2/HIF-1α/VP16, an adenoviral vector encoding a constitutively stable hybrid form of HIF-1α, increased the mRNA and protein levels of VEGF, angiopoietin-2 (Ang-2), and angiopoietin-4 (Ang-4). Infection with Ad2/CMVEV (a control vector expressing no transgene) had no effect. Angiopoietin-1 (Ang-1) expression was not detected in human endothelial cells. Ang-4 was also induced by hypoxia or Ad2/HIF-1α/VP16 in human cardiac cells, whereas Ang-1 expression remained unchanged. Recombinant Ang-4 protein protected endothelial cells against serum starvation-induced apoptosis and increased cultured endothelial cell migration and tube formation. Ad2/HIF-1α/VP16 stimulated endothelial cell proliferation and tube formation. Hypoxia- or Ad2/HIF-1α/VP16-induced tube formation was significantly reduced by a Tie-2 inhibitor. These results suggest that HIF-1 mediates the angiogenic response to hypoxia by upregulating the expression of multiple angiogenic factors. Ang-4 can function similarly as Ang-1 and substitute for Ang-1 to participate in hypoxia-induced angiogenesis. Activation of the angiopoietin/Tie-2 system may play a role in the ability of HIF-1 to induce hypervascularity without excessive permeability.
Senescence and Death of Primitive Cells and Myocytes Lead to Premature Cardiac Aging and Heart Failure
Authors: Chimenti Cristina , Kajstura Jan , Torella Daniele , Urbanek Konrad , Heleniak Hubert , Colussi Claudia , Di Meglio Franca , Nadal-Ginard Bernardo , Frustaci Andrea , Leri Annarosa , Maseri Attilio , Anversa Piero
Published: September 2003

Chronological myocardial aging is viewed as the inevitable effect of time on the functional reserve of the heart. Cardiac failure in elderly patients is commonly interpreted as an idiopathic or secondary myopathy superimposed on the old heart independently from the aging process. Thus, aged diseased hearts were studied to determine whether cell regeneration was disproportionate to the accumulation of old dying cells, leading to cardiac decompensation. Endomyocardial biopsies from 19 old patients with a dilated myopathy were compared with specimens from 7 individuals of similar age and normal ventricular function. Ten patients with idiopathic dilated cardiomyopathy were also analyzed to detect differences with aged diseased hearts. Senescent cells were identified by the expression of the cell cycle inhibitor p16
INK4a
and cell death by hairpin 1 and 2. Replication of primitive cells and myocytes was assessed by MCM5 labeling, myocyte mitotic index, and telomerase function. Aged diseased hearts had moderate hypertrophy and dilation, accumulation of p16
INK4a
positive primitive cells and myocytes, and no structural damage. Cell death markedly increased and occurred only in cells expressing p16
INK4a
that had significant telomeric shortening. Cell multiplication, mitotic index and telomerase increased but did not compensate for cell death or prevented telomeric shortening. Idiopathic dilated cardiomyopathy had severe hypertrophy and dilation, tissue injury, and minimal level of p16
INK4a
labeling. In conclusion, telomere erosion, cellular senescence, and death characterize aged diseased hearts and the development of cardiac failure in humans.