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Showing papers by "Hiroaki Shimokawa published in 2011"



Journal ArticleDOI
TL;DR: It has been demonstrated that the RhoA/Rho-kinase pathway plays an important role in various fundamental cellular functions, including contraction, motility, proliferation, and apoptosis, leading to the development of cardiovascular disease.
Abstract: Rho-kinase (ROCKs) belongs to the family of serine/threonine kinases and is an important downstream effector of the small GTP-binding protein RhoA. There are two isoforms of Rho-kinase, ROCK1 and ROCK2, and they have different functions with ROCK1 for circulating inflammatory cells and ROCK2 for vascular smooth muscle cells. It has been demonstrated that the RhoA/Rho-kinase pathway plays an important role in various fundamental cellular functions, including contraction, motility, proliferation, and apoptosis, leading to the development of cardiovascular disease. The important role of Rho-kinase in vivo has been demonstrated in the pathogenesis of vasospasm, arteriosclerosis, ischemia-reperfusion injury, hypertension, pulmonary hypertension, stroke, and heart failure. Furthermore, the beneficial effects of fasudil, a selective Rho-kinase inhibitor, have been demonstrated for the treatment of several cardiovascular diseases in humans. Thus the Rho-kinase pathway is an important new therapeutic target in cardiovascular medicine.

271 citations


Journal ArticleDOI
TL;DR: The chronic heart failure analysis and registry in the Tohoku District 2 (CHART-2) study was designed to elucidate characteristics and prognosis of patients at high risk for CVD progression due to acute heart failure syndrome (AHFS) as mentioned in this paper.
Abstract: Background: Hospitalization due to acute heart failure syndrome (AHFS) is an indicator of worsened prognosis for patients with cardiovascular disease (CVD). The Chronic Heart Failure Analysis and Registry in the Tohoku District 2 (CHART-2) Study was designed to elucidate characteristics and prognosis of patients at high risk for CVD progression due to AHFS. Methods and Results: The CHART-2 Study is a prospective observational multicenter cohort study. Patients with overt HF, structural cardiac disorder but without HF, or with coronary artery disease (CAD) have been consecutively enrolled from October 2006. As of March 2010, a total of 10,219 patients have been recruited, making the Study the largest multicenter prospective cohort of HF patients in Japan. The mean patient age was 68.2±12.3 years and male patients accounted for 69.8%. Overt HF was observed in 46.3% of patients; and 53.7% did not have HF but were at high risk for AHFS. As HF stage progressed, the prognostic risks (eg, chronic kidney disease, reduced ejection fraction, and increased B-type natriuretic peptide level) became more prominent. Compared with the previous CHART-1 study, the prevalence of ischemic etiology and risk factors (hypertension, diabetes) have increased, as in Western studies. Conclusions: This first report demonstrates the trend of westernization of ischemic etiology and clinical characteristics of HF patients in Japan, indicating the importance of appropriate management and prevention of CAD to prevent AHFS. (Circ J 2011; 75: 823-833)

195 citations


Journal ArticleDOI
TL;DR: In this paper, the authors examined the clinical characteristics and outcomes of patients with vasospastic angina (VSA) in a nationwide multicenter registry by the Japanese Coronary Spasm Association.
Abstract: Background— Coronary artery spasm plays an important role in the pathogenesis of ischemic heart disease; however, its role in sudden cardiac death remains to be fully elucidated. We examined the clinical characteristics and outcomes of patients with vasospastic angina (VSA) in our nationwide multicenter registry by the Japanese Coronary Spasm Association. Methods and Results— Between September 2007 and December 2008, 1429 patients with VSA (male/female, 1090/339; median, 66 years) were identified. They were characterized by a high prevalence of smoking and included 35 patients who survived out-of-hospital cardiac arrest (OHCA). The OHCA survivors, as compared with the remaining 1394 non-OHCA patients, were characterized by younger age (median, 58 versus 66 years; P <0.001) and higher incidence of left anterior descending coronary artery spasm (72% versus 53%, P <0.05). In the OHCA survivors, 14 patients underwent implantable cardioverter-defibrillator (ICD) implantation while intensively treated with calcium channel blockers. Survival rate free from major adverse cardiac events was significantly lower in the OHCA survivors compared with the non-OHCA patients (72% versus 92% at 5 years, P <0.001), including appropriate ICD shocks for ventricular fibrillation in 2 patients. Multivariable analysis revealed that OHCA events were significantly correlated with major adverse cardiac events (hazard ratio, 3.25; 95% confidence interval, 1.39 to 7.61; P <0.01). Conclusions— These results from the largest vasospastic angina cohort indicate that vasospasm patients who survived OHCA are high-risk population. Further studies are needed to determine whether implantable cardioverter-defibrillator therapy improves patient prognosis.

171 citations


Journal ArticleDOI
TL;DR: In this article, a total of 172 consecutive patients with chronic heart failure, who underwent cardiac catheterization and endomyocardial biopsy between January 2001 and September 2008, were examined.
Abstract: Background: Although myocardial fibrosis plays an important role in the progression of heart failure (HF), its prognostic impact still remains to be clarified. Methods and Results: A total of 172 consecutive patients with chronic HF, who underwent cardiac catheterization and endomyocardial biopsy between January 2001 and September 2008, were examined. They were divided into 2 groups: HF with preserved ejection fraction (HFPEF; left ventricular ejection fraction [LVEF] ≥50%, n=81); and HF with reduced LVEF (HFREF; LVEF <50%, n=91). The collagen volume fraction (CVF) in biopsy samples was calculated and its prognostic impact examined. Mean follow-up in the HFPEF and the HFREF groups was 41±33 months and 41±26 months, respectively. Although CVF was similar between the 2 groups (1.83±1.54% vs. 2.07±2.35%), CVF was significantly correlated with LV end-diastolic pressure in the HFREF group but not in the HFPEF group. When HF stage was adjusted, the long-term prognosis was comparable between the 2 groups. When the patients were divided into 2 groups according to median CVF, however, severe fibrosis was a significant predictor for all-cause death (P=0.014) and cardiac events (P=0.02) in the HFREF, but not in the HFPEF group. Conclusions: Myocardial fibrosis evaluated on biopsy samples is a useful indicator for long-term survival, suggesting that it may be an important therapeutic target as well. (Circ J 2011; 75: 2605-2613)

125 citations


Journal ArticleDOI
TL;DR: All physicians must evaluate kidney function using estimated glomerular filtration rate calculated by the new Japanese equation in patients with HF to improve the prognosis of patients with the diseases.

102 citations


Journal ArticleDOI
TL;DR: Progress has been made in the understanding of the pathophysiology, diagnosis and treatment of pulmonary hypertension, and several new drugs are under clinical trial, including fasudil (a Rho-kinase inhibitor), riosiguat (a soluble guanylate cyclase activator), and imatinib (a tyrosine kinase inhibitor).
Abstract: Pulmonary hypertension (PH) is a fatal disease caused by small pulmonary artery obstruction from vascular proliferation and remodeling. PH is characterized by elevated pulmonary arterial pressure and increased pulmonary vascular resistance, frequently leading to right-sided heart failure and death. The classification of PH has been recently updated to include 5 major categories of the disorder, are as: Group 1, pulmonary arterial hypertension (PAH); Group 2, PH due to left heart disease; Group 3, PH due to lung diseases and/or hypoxia; Group 4, chronic thromboembolic PH (CTEPH); and Group 5, others. Recently, significant progress has been made in the understanding of the pathophysiology, diagnosis and treatment of PH. Regarding the pathophysiology of the disorder, direct evidence for Rho-kinase activation in the pulmonary artery from PAH patients has been provided. Regarding diagnosis, optical coherence tomography is useful as a new differential diagnostic tool for distal type CTEPH vs. PAH. Regarding treatment, in addition to the conventional therapy, several new drugs are under clinical trial, including fasudil (a Rho-kinase inhibitor), riosiguat (a soluble guanylate cyclase activator), and imatinib (a tyrosine kinase inhibitor). In addition, pulmonary angioplasty and intensive immunosuppressive therapy may be effective for CTEPH and connective tissue disease-associated PAH, respectively. We briefly review the recent progress in the management of PH. (Circ J 2011; 75: 1801-1810)

79 citations


Journal ArticleDOI
TL;DR: Results indicate that Rho-kinase activity in circulating neutrophils is enhanced in patients with VSA and may be a useful biomarker for diagnosis and disease activity assessment of the vasospastic disorder.

77 citations


Journal ArticleDOI
TL;DR: It is suggested that intensive immunosuppressive therapy as well as conventional vasodilator therapy improves the pulmonary hemodynamics and long-term prognosis of patients with CPAH.
Abstract: Background: Pulmonary arterial hypertension (PAH) remains a serious disease characterized by elevated pulmonary artery pressure (PAP) and increased pulmonary vascular resistance (PVR). Among its subtypes, PAH associated with connective tissue disease (CPAH) has the worse prognosis, because of resistance to conventional vasodilator therapy. We hypothesized that intensive immunosuppressive therapy (IIT) could improve the pulmonary hemodynamics in CPAH. Methods and Results: In our pulmonary hypertension (PH) cohort of 182 patients, we evaluated 13 consecutive patients with CPAH who received IIT combined with cyclophosphamide and glucocorticosteroids (IIT group, mean age 45±8 years, 12 females and 1 male). We compared them with 8 historical controls (control group: mean age 52±18 years, 8 females) for pulmonary hemodynamics and prognosis. Both groups were treated with conventional vasodilator therapy. Although the mean PAP (mPAP) remained unchanged in the control group, IIT significantly decreased mPAP (40±9 to 29±11mmHg, P<0.01) and tended to decrease PVR (700±434 to 481±418 dyne·s·cm-5, P=0.07). Importantly, in 6 of the 13 patients in the IIT group, mPAP was almost normalized (<25mmHg) and remained stabilized for more than 1 year. Furthermore, the IIT group showed significantly better prognosis compared with the control group (P<0.01). Conclusions: These results suggest that IIT as well as conventional vasodilator therapy improves the pulmonary hemodynamics and long-term prognosis of patients with CPAH. (Circ J 2011; 75: 2668-2674)

71 citations


Journal ArticleDOI
TL;DR: The low-energy SW therapy induces therapeutic lymphangiogenesis by up-regulating VEGF-C and bFGF, and improves lymphoedema in a rat-tail model, suggesting that low- energy SW therapy could be a non-invasive and effective strategy for lymphoingema in humans.

61 citations


Journal ArticleDOI
TL;DR: In vivo studies have demonstrated that extracorporeal cardiac SW therapy with a low-energy SW up-regulates the expression of VEGF, induces neovascularization, and improves myocardial ischemia in a porcine model of chronic myocardia, without any adverse effects in vivo.
Abstract: Ischemic heart disease is the leading cause of death and a major cause of hospital admissions, with the number of affected patients increasing worldwide. The current management of ischemic heart disease has three major therapeutic options: medication, percutaneous coronary intervention (PCI), and coronary artery bypass grafting (CABG). However, the prognosis for patients with severe ischemic heart disease without indications for PCI or CABG still remains poor due to the lack of effective treatments. It is therefore crucial to develop alternative therapeutic strategies for severe ischemic heart disease. Extracorporeal shock wave (SW) therapy was introduced clinically more than 20 years ago to fragment kidney stones, which has markedly improved the treatment of urolithiasis. We found that a low-energy SW (about 10% of the energy density used for urolithiasis) effectively increases the expression of vascular endothelial growth factor (VEGF) in cultured endothelial cells. Based on this in vitro study, we initiated in vivo studies and have demonstrated that extracorporeal cardiac SW therapy with a low-energy SW up-regulates the expression of VEGF, induces neovascularization, and improves myocardial ischemia in a porcine model of chronic myocardial ischemia, without any adverse effects in vivo. On the basis of promising results in animal studies, we performed a series of clinical studies in patients with severe coronary artery disease without indication for PCI or CABG, including, firstly, an open trial followed by a placebo-controlled, double-blind study. In both studies, our extracorporeal cardiac SW therapy improved symptoms, exercise capacity, and myocardial perfusion in patients with severe coronary artery disease. Importantly, no procedural complications or adverse effects were noted. The SW therapy was also effective in ameliorating left ventricular remodeling after acute myocardial infarction (MI) in pigs and in enhancing angiogenesis in hind-limb ischemia in rabbits. Based on these animal studies, we are also conducting clinical studies in patients with acute MI and in those with peripheral artery disease. Thus, our extracorporeal cardiac SW therapy appears to be an effective, safe, and non-invasive angiogenic approach in cardiovascular medicine and its indication could be extended to a variety of ischemic diseases in the near future. In this article, we briefly summarize our work in animals and humans, and discuss the advantages and perspectives of our extracorporeal SW therapy.

Journal ArticleDOI
TL;DR: Evidence is provided that the NOS/NO pathway contributes to behavioral pain responses evoked by tissue injury and nerve injury, and nNOS may be important for spinal microglial activation and tactile allodynia after nerve injury.
Abstract: Several studies have investigated the involvement of nitric oxide (NO) in acute and chronic pain using mice lacking a single NO synthase (NOS) gene among the three isoforms: neuronal (nNOS), inducible (iNOS) and endothelial (eNOS). However, the precise role of NOS/NO in pain states remains to be determined owing to the substantial compensatory interactions among the NOS isoforms. Therefore, in this study, we used mice lacking all three NOS genes (n/i/eNOS -/- mice) and investigated the behavioral phenotypes in a series of acute and chronic pain assays. In a model of tissue injury-induced pain, evoked by intraplantar injection of formalin, both iNOS -/- and n/i/eNOS -/- mice exhibited attenuations of pain behaviors in the second phase compared with that in wild-type mice. In a model of neuropathic pain, nerve injury-induced behavioral and cellular responses (tactile allodynia, spinal microglial activation and Src-family kinase phosphorylation) were reduced in n/i/eNOS -/- but not iNOS -/- mice. Tactile allodynia after nerve injury was improved by acute pharmacological inhibition of all NOSs and nNOS. Furthermore, in MG-5 cells (a microglial cell-line), interferon-γ enhanced NOSs and Mac-1 mRNA expression, and the Mac-1 mRNA increase was suppressed by L-NAME co-treatment. Conversely, the NO donor, sodium nitroprusside, markedly increased mRNA expression of Mac-1, interleukin-6, toll-like receptor 4 and P2X4 receptor. Our results provide evidence that the NOS/NO pathway contributes to behavioral pain responses evoked by tissue injury and nerve injury. In particular, nNOS may be important for spinal microglial activation and tactile allodynia after nerve injury.

Journal ArticleDOI
TL;DR: Long-term treatment with EPA ameliorates I/R injury partly through Rho-kinase pathway inhibition in vivo and preserves myocardial eNOS activity with a significant correlation noted between them.
Abstract: Background: Eicosapentaenoic acid (EPA), the major n-3 fatty acid in fish oil, exerts cardioprotective effects against ischemic heart disease; however, the detailed mechanisms remain to be elucidated. Rho-kinase plays an important role in the pathogenesis of cardiovascular diseases including ischemia-reperfusion (I/R) injury. Thus, the hypothesis that long-term EPA treatment ameliorates myocardial I/R injury through Rho-kinase pathway inhibition in pigs in vivo was investigated. Methods and Results: Male pigs were treated with either a control chow or EPA (600·mg·kg-1·day-1) for 3 weeks (n=8 each) and were subjected to myocardial ischemia by 90-min occlusion of the left circumflex coronary artery and subsequent 60-min reperfusion. The EPA group had an increased EPA level in red blood cells (4.4±0.3mol%). The EPA treatment significantly ameliorated myocardial I/R injury, including regional wall motion abnormality (EPA 5.3±3.6 vs. control 35.1±3.8 unit, P<0.0001), left ventricular ejection fraction (EPA 43±9% vs. control 32±7%, P<0.05), occurrence of ventricular arrhythmias (EPA 181±73 vs. control 389±51 events, P<0.0001) and histological accumulation of inflammatory cells (P<0.01). Importantly, the EPA treatment significantly inhibited myocardial Rho-kinase activity (assessed by the extent of the myosin-binding subunit phosphorylation) (EPA 0.47±0.11 vs. control 0.77±0.14, P<0.05) and preserved myocardial eNOS activity (EPA 0.56±0.13 vs. control 0.23±0.07, P<0.01) with a significant correlation noted between them. Conclusions: Long-term treatment with EPA ameliorates I/R injury partly through Rho-kinase pathway inhibition in vivo. (Circ J 2011; 75: 1843-1851)

Journal ArticleDOI
TL;DR: Results indicate that long-term treatment with EPA reduces ischemia-induced VF and SCD in pigs in vivo, for which attenuation of MAP duration shortening may be involved.

Journal ArticleDOI
TL;DR: The results indicate a beneficial effect of selective blockade of Rho-kinase in animals with autoimmune inflammation of the peripheral nerves, and may provide a rationale for the selective blockade for Guillain-Barré syndrome.

Journal ArticleDOI
TL;DR: The results suggest that the Seattle Heart Failure Model risk score is the most suitable for the discrimination and calibration of mortality risk stratification in patients with cardiovascular disease.
Abstract: Risk stratification models are effective tools for the management of cardiovascular diseases. Although several risk scores have been proposed, the relevance and superiority of these predictive models have not been fully validated in an independent and nonclinical trial-based population. We studied 2,472 consecutive patients initially hospitalized in our institution from April 2004 to December 2009. Risk scores were calculated for each patient using 4 risk score models, including the Seattle Heart Failure Model (SHFM), Acute Decompensated Heart Failure National Registry regression model, the American Heart Association Get With The Guidelines-Heart Failure score, and the Association of Health Aging and Body Composition Heart Failure score. The predictive ability for the composite end point, including total death, heart transplantation, and left ventricle assist device implantation, was assessed by calculating the area under the receiver operating characteristic curve for each model. During the follow-up period after admission (median 924.5 days), the combined end point occurred in 295 patients (11.8%), including 27 in-hospital deaths (1.1%). Compared with the other 3 risk score models, the SHFM risk score demonstrated a greater area under the curve for the combined end point at the overall, in-hospital, 30-day, and 1-, 2-, and 3-year follow-up point (0.741 to 0.890). The survival rate predicted by SHFM demonstrated an excellent correlation with the actual survival rate ( R 2 = 0.990). In conclusion, these results suggest that the SHFM risk score is the most suitable for the discrimination and calibration of mortality risk stratification in patients with cardiovascular disease.

Journal ArticleDOI
TL;DR: Besides intracellular functions, CyPA has emerged as a potential biomarker and mediator of cardiovascular disease and is a secreted molecule that has a pathological role in the cardiovascular system.

Journal ArticleDOI
TL;DR: The results suggest that recombinant human EPO ameliorates the cardiac remodeling and the premature death associated with chronic LV pressure overload through the mechanisms independent of angiogenesis.
Abstract: Chronic left ventricular (LV) pressure overload induced by hypertension is one of the most common causes of heart failure. Earlier reports have shown the cardioprotective effects of erythropoietin (EPO). In the present study, we tested the hypothesis that recombinant human EPO exerts a protective effect against pressure-overload induced LV remodeling. Mice subjected to transverse aortic constriction (TAC) (n = 70) were randomly assigned to the treatment with phosphate buffer solution (PBS) (TAC-PBS) or EPO (2,000 U/kg twice a week) (TAC-EPO). At 8 weeks after TAC, LV weight was comparably increased in both TAC groups compared with sham-operated mice (Sham) (both P < 0.001). The treatment with EPO improved the survival of TAC mice as compared with treatment with PBS (80 vs. 47%, P < 0.01), which was associated with reductions in the extent of myocardial fibrosis and the number of TUNEL positive cardiomyocytes (both P < 0.05). Echocardiography revealed that TAC increased LV chamber diameter and decreased LV fractional shortening compared with Sham (P < 0.05), which was ameliorated by the treatment with EPO (P < 0.05). In TAC-EPO as compared to TAC-PBS, phosphorylation of STAT3, Akt and eNOS was all increased, while phosphorylation of p38 was decreased (all P < 0.05). Importantly, the expression level of VEGF and the capillary density in LV myocardium were similar among the 3 groups. These results suggest that recombinant human EPO ameliorates the cardiac remodeling and the premature death associated with chronic LV pressure overload through the mechanisms independent of angiogenesis.

Journal ArticleDOI
TL;DR: Prospective strategies including accurate risk stratification, effective prevention of disease progression through evidence-based treatments, optimally personalized treatment particularly in elderly individuals, and life-long control of CAD risk factors are required to manage HF in Japan.
Abstract: There are approximately 23 million patients with heart failure (HF) worldwide. The prognosis of patients with HF is still poor and a prospective approach for preventing and treating HF is necessary. The number of HF patients in Japan has been increasing since 1950 mainly because of a rapidly aging population. Furthermore, westernized dietary pattern, reduced physical activity, and obesity have become prominent, particularly in younger Japanese men. There is an increasing trend of diabetes and dyslipidemia, and the prevalence of smoking and hypertension continues to remain high. One of the largest HF cohorts in Japan, the CHART Studies, showed that coronary artery disease (CAD) was the most frequent etiology of HF currently. Thus, prospective strategies including accurate risk stratification, effective prevention of disease progression through evidence-based treatments, optimally personalized treatment particularly in elderly individuals, and life-long control of CAD risk factors are required to manage HF in Japan.

Journal ArticleDOI
TL;DR: The results indicate that the complete disruption of all the NOS genes causes markedly accelerated vascular lesion formation caused by blood flow disruption in mice in vivo, demonstrating the crucial vasculoprotective role of the whole endogenous NOS system.

Journal ArticleDOI
TL;DR: Findings suggest a role for the OX40L-derived immune response and epistatic genetic effect in immune-mediated pathogenesis of PAH.
Abstract: Pulmonary hypertension (PH) refers to a spectrum of diseases with elevated pulmonary artery pressure. Pulmonary arterial hypertension (PAH) is a disease category that clinically presents with severe PH and that is histopathologically characterized by the occlusion of pulmonary arterioles, medial muscular hypertrophy, and/or intimal fibrosis. PAH occurs with a secondary as well as a primary onset. Secondary PAH is known to be complicated with immunological disorders. The aim of the present study is to histopathologically and genetically characterize a new animal model of PAH and clarify the role of OX40 ligand in the pathogenesis of PAH. Spontaneous onset of PAH was stably identified in mice with immune abnormality because of overexpression of the tumor necrosis factor (TNF) family molecule OX40 ligand (OX40L). Histopathological and physical examinations revealed the onset of PAH-like disorders in the C57BL/6 (B6) strain of OX40L transgenic mice (B6.TgL). Comparative analysis performed using different strains of transgenic mice showed that this onset depends on the presence of OX40L in the B6 genetic background. Genetic analyses demonstrated a susceptibility locus of a B6 allele to this onset on chromosome 5. Immunological analyses revealed that the excessive OX40 signals in TgL mice attenuates expansion of regulatory T cells the B6 genetic background, suggesting an impact of the B6 genetic background on the differentiation of regulatory T cells. Present findings suggest a role for the OX40L-derived immune response and epistatic genetic effect in immune-mediated pathogenesis of PAH.

Journal ArticleDOI
TL;DR: The results suggest that a increase in diastolic [Ca(2+)](i) and an increase in Ca(2+) sensitivity of the sarcoplasmic reticulum Ca(1+) release channel accelerate Ca( 2+) waves in ventricular hypertrophy, thereby causing arrhythmogenesis.
Abstract: Background: Triggered arrhythmias arise from delayed afterdepolarizations (DADs), with Ca2+ waves playing an important role in their formation. In ventricular hypertrophy, however, it remains unclear how Ca2+ waves change their propagation features and affect arrhythmogenesis. We addressed this important issue in a rat model of hypertrophy. Methods and Results: Rats were given a subcutaneous injection of 60mg/kg monocrotaline (MCT-rats) or solvent (Ctr-rats). After 4 weeks, MCT-rats showed high right ventricular (RV) pressure and RV hypertrophy. Trabeculae were dissected from 36 right ventricles. The force was measured using a silicon strain gauge and regional intracellular Ca2+ ([Ca2+]i) was determined using microinjected fura-2. Reproducible Ca2+ waves were induced by stimulus trains (2Hz, 7.5s). MCT-rats showed a higher diastolic [Ca2+]i and faster and larger Ca2+ waves (P<0.01). The velocity and amplitude of Ca2+ waves were correlated with the diastolic [Ca2+]i both in the Ctr- and MCT-rats. The velocity of Ca2+ waves in the MCT-rats was larger at the given amplitude of Ca2+ waves than that in the Ctr-rats (P<0.01). The amplitude of DADs was correlated with the velocity and amplitude of Ca2+ waves in the Ctr- and MCT-rats. Conclusions: The results suggest that an increase in diastolic [Ca2+]i and an increase in Ca2+ sensitivity of the sarcoplasmic reticulum Ca2+ release channel accelerate Ca2+ waves in ventricular hypertrophy, thereby causing arrhythmogenesis. (Circ J 2011; 75: 1343-1349)

Journal ArticleDOI
TL;DR: Results indicate that the vascular Epo/EpoR system plays an important protective role against hypoxia/ischemia, demonstrating that this system is a novel therapeutic target in cardiovascular medicine.
Abstract: Although hypoxia and ischemia are known to be involved in the pathogenesis of cardiovascular disease, specific therapeutic targets still remain elusive. To address this important issue, we have performed 2 series of experimental studies, aiming at erythropoietin (Epo)/Epo receptor (EpoR) based on the following backgrounds. Epo has long been regarded as a hematopoietic hormone that acts exclusively in the proliferation and differentiation of erythroid progenitors. Although recent studies have demonstrated that EpoR is expressed in the cardiovascular system, the potential protective role of the vascular Epo/EpoR system in vivo remains to be examined. We hypothesized that the vascular Epo/EpoR system plays an important protective role against the development of cardiovascular disease. Using vascular EpoR-deficient mouse, we demonstrated that the vascular Epo/EpoR system plays a crucial role for endothelial function and vascular homeostasis. The vascular Epo/EpoR system is important for the activation of the vascular endothelial growth factor/vascular endothelial growth factor receptor-2 system, inhibits hypoxia-induced pulmonary endothelial damage and promotes ischemia-induced angiogenesis in vivo. These results indicate that the vascular Epo/EpoR system plays an important protective role against hypoxia/ischemia, demonstrating that this system is a novel therapeutic target in cardiovascular medicine.

Journal ArticleDOI
TL;DR: Results indicate that SCBs produce atrial PRR through the reduction of sodium channel availability, thought to be one of main anti-arrhythmic mechanisms of class I sodium channel blockers (SCBs).
Abstract: Atrial fibrillation (AF) is the most common tachyarrhythmia. Shortening of atrial action potential duration (APD) and effective refractory period (ERP) is one of the crucial factors in the occurrence and maintenance of AF. ERP is usually shorter than APD, but ERP can be prolonged beyond action potential repolarization in some situations. It is termed as post-repolarization refractoriness (PRR) that is thought to be one of main anti-arrhythmic mechanisms of class I sodium channel blockers (SCBs). Most of anti-arrhythmic agents, including SCBs, have multi-channel blocking effects. It is unknown whether atrial PRR with SCBs is associated with the reduction of sodium channel availability. We therefore explored the relationship between the reduction of sodium channel availability with a pure SCB (pilsicainide or tetrodotoxin) and atrial PRR using the left atrial appendage from male guinea pigs (each group, n = 3~10). Employing a standard microelectrode technique, we evaluated APD measured at 90% repolarization (APD90) and the sodium channel availability, judged from the maximal rate of rise of action potential (Vmax). At a 500-msec basic cycle length (BCL), pilsicainide prolonged atrial ERP assessed by a single extra-stimulus in response to the decrement of the Vmax in a dose-dependent manner without affecting APD90. Furthermore, pilsicainide increased the ERP and decreased the Vmax in a rate-dependent manner without APD90 prolongation at a shorter BCL (200 msec). Importantly, tetrodotoxin reproduced the effects of pilsicainide on atrial ERP, APD90, and Vmax. These results indicate that SCBs produce atrial PRR through the reduction of sodium channel availability.


Journal Article
TL;DR: In this paper, the authors provide a comprehensive editorial perspective on potential conflicts of interest (COI) related issues in biomedical journals and provide insights into the current COI policies and practices among European Society of Cardiology National Cardiovascular Journals.
Abstract: Disclosure of potential conflicts of interest (COIs) is used by biomedical journals to guarantee credibility and transparency of the scientific process. Conflict of interest disclosure, however, is not systematically nor consistently dealt with by journals. Recent joint editorial efforts paved the way towards the implementation of uniform vehicles for COI disclosure. This paper provides a comprehensive editorial perspective on classical COI-related issues. New insights into the current COI policies and practices among European Society of Cardiology National Cardiovascular Journals, as derived from a cross-sectional survey using a standardized questionnaire, are discussed.


Patent
27 Jul 2011
TL;DR: In this article, an optical fiber is employed in an underwater shockwave generating device (10) which projects a laser beam underwater and generates an underwater tsunami wave, provided that the optical fiber has good laser beam condensation efficiency and is highly resilient.
Abstract: Provided are an optical fiber which has good laser beam condensation efficiency and is highly resilient, and a shockwave generating device employing same. An optical fiber (11) is employed in an underwater shockwave generating device (10) which projects a laser beam underwater and generates an underwater shockwave. The optical fiber (11) comprises: a main body part (16); and a laser convergence part (17) which is disposed upon a leading end thereof. The laser convergence part (17) is configured so as to exhibit an approximately frustum shape wherein the diameter of the leading end (18a) is narrower than the diameter of the base end (18b), and such that an interior angle θ with respect to a radial direction of a lateral face of an axial cross-section gradually decreases toward the front thereof.

Journal Article
TL;DR: Results indicate that CaMKKβ and caveolin-1 and PKG1α are involved in enhanced EDHF-mediated responses in microvessels, providing clues for novel strategy for vascular protection.
Abstract: Background: Endothelium-derived hyperpolarizing factor (EDHF) plays an important role in organ protection by modulating vascular tone, especially in microvessels. We have demonstrated in animals an...

01 Jan 2011
TL;DR: Direct volumetry versus cylindrical approximation to assess left atrial volumetric changes before and after catheter ablation for atrial fibrillation using ECG-gated MDCT is compared.
Abstract: Poster: "ECR 2011 / C-1812 / Direct volumetry versus cylindrical approximation to assess left atrial volumetric changes before and after catheter ablation for atrial fibrillation using ECG-gated MDCT" by: "S. Yoshida, K. Takase, S. kakiuchi, M. Tsuda, K. Seiji, K. fukuda, Y. wakayama, H. shimokawa, S. Takahashi; Sendai/JP"