研究者業績

永井 良三

ナガイ リョウゾウ  (Ryozo Nagai)

基本情報

所属
自治医科大学 自治医科大学 学長
学位
博士(医学)

J-GLOBAL ID
200901024033893870
researchmap会員ID
1000190318

受賞

 7

論文

 955
  • Motoki Inoue, Makoto Sasaki, Yasuyuki Katada, Katsuhito Fujiu, Ichiro Manabe, Ryozo Nagai, Tetsushi Taguchi
    Journal of biomedical materials research. Part A 101(7) 2049-57 2013年7月  査読有り
    Biodegradable composite matrices comprising poly-(L-lactic acid) (PLLA) and citric acid-crosslinked alkali-treated gelatin (AlGelatin) with endothelialization, antithrombogenic, and drug release properties were prepared. The characterization of composite matrices with various mixing ratios was performed by evaluating their swelling ratio, endothelial cell culture, antithrombogenic tests, and drug release behavior. Tamibarotene (Am80), which specifically inhibits smooth muscle cell proliferation, was employed as the drug. The swelling ratio of composite matrices decreased as the PLLA content decreased. The number of endothelial cells cultured on the surfaces of composite matrices was maximal at the PLLA/AlGelatin-TSC ratio of 80/20. Antithrombogenic tests revealed that the levels of platelets and fibrin network formation decreased as the AlGelatin-TSC content increased. The Am80 release test indicated that the release rate decreased as PLLA content increased. Using the resulting composite matrix, Am80-eluting stents possessing a smooth surface and a coating thickness of ∼15 μm were successfully obtained. Am80 was continuously released from the resulting stent at ∼40%, up to 28 days without burst release. Therefore, Am80-eluting stent with its antithrombogenic and endothelialization properties has great potential for clinical use.
  • Katsuhito Fujiu, Ryozo Nagai
    Basic research in cardiology 108(4) 357-357 2013年7月  査読有り
    The heart contains various types of cells, including cardiomyocytes, cardiac fibroblasts, many kinds of immune cells and vascular cells. Initial studies mainly focused on cardiomyocytes, which directly reflect the contractile function of the heart. Recently, pivotal functions of cardiac fibroblasts have been revealed in the maintenance of cardiac function, physiological cardiac remodeling after heart stress and pathological remodeling using genetically engineered mouse models, like the fibroblast-specific gene knockout mouse, bone marrow transplantation and immune cell-specific gene knockout. Moreover, chronic inflammation is considered to be a basic pathological mechanism that underlies various diseases, including heart failure. In the development of heart failure, the contributions of immune cells like T lymphocytes and monocyte/macrophage lineage cells have been also reported. Immune cells have diverse and multiple functions in regulating both pro-inflammatory effects and the resolution of heart failure. On the one hand, immune cells have protective effects to compensate for and overcome heart stresses. On the other hand, they also contribute to sustained inflammation and result in the development of heart failure. These observations prompted a shift in the heart-related studies to include the complex communications between cardiomyocytes and other kinds of cardiac cells, including inflammatory cells residing in or recruited to the heart. This review will summarize the current knowledge regarding cell-cell interactions during cardiac remodeling and the development of heart failure. We will especially focus on the interactions among cardiomyocytes, cardiac fibroblasts and immune cells.
  • Ryota Sakurai, Tsukasa Inajima, Hideaki Kaneda, Ryozo Nagai, Hideki Hashimoto
    INTERNATIONAL JOURNAL OF CARDIOLOGY 167(1) 162-167 2013年7月  査読有り
    Background: Sirolimus-eluting stents (SES) have demonstrated more favorable outcomes compared with bare metal stents (BMS) for ST-segment elevation myocardial infarction (STEMI) within medium term follow up in randomized controlled trials (RCT). However, long-term outcomes remain unknown. Methods: We conducted a meta-analysis of RCT comparing SES with BMS in STEMI patients at long-term follow up, defined as 2 years or more after primary percutaneous coronary intervention (PCI). The clinical end points of our interest were death, recurrent myocardial infarction (MI), definite stent thrombosis (ST), and target lesion revascularization (TLR). We calculated the pooled estimate based on a fixed-effects model using Peto odds ratio (OR) for rare events. If heterogeneity was observed across an individual RCT, an analysis based on a random-effects model was performed. Results: Four RCT were included in this study, involving 1304 patients (656 patients randomized to SES and 648 patients to BMS). Up to 4 years, SES showed a significant reduction in not only TLR (OR: 0.44, 95% confidence interval (CI): 0.31 to 0.62, p<0.001) but also mortality (OR: 0.62, 95% CI: 0.39 to 1.00, p = 0.049) compared with BMS. In contrast, the proportions of recurrent MI (OR: 0.82, 95% CI: 0.52 to 1.28, p = 0.378) and definite ST (OR: 1.13, 95% CI: 0.56 to 2.27, p = 0.740) were comparable between the 2 groups. Conclusions: In this meta-analysis of long-term RCT, primary PCI for STEMI patients with SES was associated with a decrease in mortality as well as TLR without an increase in recurrent MI or definite ST compared with BMS. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
  • 西崎 祐史, 島田 和典, 谷 樹昌, 小川 崇之, 安東 治郎, 高橋 政夫, 山本 雅人, 篠崎 智大, 宮内 克己, 長尾 建, 平山 篤志, 吉村 道博, 小室 一成, 永井 良三, 代田 浩之
    日本動脈硬化学会総会プログラム・抄録集 45回 137-137 2013年6月  
  • Masami Ochi, Atsushi Amano, Hirokuni Arai, Tohru Asai, Hiroyuki Daida, Hisayoshi Fujiwara, Taiko Horii, Takaaki Isshiki, Michio Kawasuji, Takeshi Kimura, Junjiro Kobayashi, Izuru Masuda, Hiroshi Niinami, Hiroshi Nishida, Kazuhiko Nishigaki, Satoshi Ogawa, Takayuki Ohno, Hitoshi Okabayashi, Yoshitaka Okamura, Ryuzo Sakata, Teruo Shiba, Hisayoshi Suma, Tetsuya Sumiyoshi, Shinichi Takamoto, Tadashi Tashiro, Hitoshi Yaku, Fumio Yamamoto, Tsutomu Yamazaki, Go Watanabe, Kiyoshi Doi, Masahiro Fujii, Michiya Hanyu, Soichiro Kitamura, Hiroyuki Nakajima, Masaru Nishimi, Tomoaki Suzuki, Koichi Tabayashi, Osamu Tagusari, Shigeyuki Tomita, Atsushi Hirayama, Kanji Kawachi, Nobuya Koyama, Ryozo Nagai
    CIRCULATION JOURNAL 77(6) 1608-1641 2013年6月  査読有り
  • Takahide Kohro, Tsutomu Yamazaki, Hiroki Sato, Kazuhiko Ohe, Ryozo Nagai
    Hypertension Research 36(6) 559-563 2013年6月  査読有り
    The Japanese Society of Hypertension (JSH) updated its hypertension management guidelines in 2009. One of the most significant changes with respect to the 2004 version was the stance towards the use of diuretics: in 2004, their use was cautioned against, but in 2009, it was actively promoted. The purpose of this study was to measure the impact of this change in guidelines on prescription patterns for antihypertensive medications, and to investigate the overall trend in the use of antihypertensives. We used monthly claims data obtained from a database company. Data of patients who were 20 or more years old and prescribed antihypertensives were extracted and analyzed. There were 66 223 patients who were prescribed antihypertensives (mean age 53.6±11.0). Of these, 38 130 were men and 28 093 were women. The two most prescribed classes of antihypertensives were angiotensin receptor blockers, whose usage steadily increased over a 7-year period, and calcium channel blockers. Prescriptions for antihypertensives in these two classes were also more likely to be continued than those for other antihypertensive classes. The prescription rate for diuretics increased from December 2006 (P&lt 0.0001), but the rate of increase was the same before and after 2009 (P=0.09). The clinical guidelines published in 2009 had no apparent impact on the trend of diuretic prescriptions, despite the radical change in stance concerning the use of antihypertensives. Further effort to disseminate the content of these guidelines, so that it is reflected in actual clinical practice, may be warranted. © 2013 The Japanese Society of Hypertension.
  • Shota Fukuda, Kenei Shimada, Masatoshi Fujita, Minoru Yoshiyama, Junichi Yoshikawa, Takahide Kohro, Doubun Hayashi, Tsutomu Yamazaki, Ryozo Nagai
    Journal of Cardiology 61(6) 387-392 2013年6月  査読有り
    Background: Although increased attention is given to assess absolute values of serum cholesterol profiles as optimal markers for preventing future cardiovascular (CV) events, changes in cholesterol profiles also have the potential to be associated with CV disease outcome in Japanese patients with acute coronary syndrome (ACS). Methods: From the database of the Japanese Coronary Artery Disease (JCAD) study, 2664 patients with ACS who had serial measurements of serum cholesterol profile parameters were enrolled. These patients were followed-up for a mean period of 2.7 years. The endpoint was all CV events. Baseline clinical characteristics of patients with and without CV events were adjusted by the propensity score matching analysis. Results: None of the serum absolute cholesterol profiles at baseline and 6 months later was associated with CV events, except for baseline serum total cholesterol level. However, large improvements in cholesterol profiles correlated with better CV disease outcome. Conclusions: This subanalysis of JCAD demonstrated the importance of serial assessment of serum cholesterol profiles for secondary prevention of CV events in Japanese patients with ACS. Changes in serum cholesterol profiles, rather than their absolute values, correlated with future CV events. © 2013.
  • Eisuke Amiya, Masafumi Watanabe, Norihiko Takeda, Tetsuya Saito, Taro Shiga, Yumiko Hosoya, Tomoko Nakao, Yasushi Imai, Ichiro Manabe, Ryozo Nagai, Issei Komuro, Koji Maemura
    The Journal of biological chemistry 288(20) 14497-509 2013年5月17日  査読有り
    Vascular endothelial function is impaired in hypercholesterolemia partly because of injury by modified LDL. In addition to modified LDL, free cholesterol (FC) is thought to play an important role in the development of endothelial dysfunction, although the precise mechanisms remain to be elucidated. The aim of this study was to clarify the mechanisms of endothelial dysfunction induced by an FC-rich environment. Loading cultured human aortic endothelial cells with FC induced the formation of vesicular structures composed of FC-rich membranes. Raft proteins such as phospho-caveolin-1 (Tyr-14) and small GTPase Rac were accumulated toward FC-rich membranes around vesicular structures. In the presence of these vesicles, angiotensin II-induced production of reactive oxygen species (ROS) was considerably enhanced. This ROS shifted endothelial NOS (eNOS) toward vesicle membranes and vesicles with a FC-rich domain trafficked toward perinuclear late endosomes/lysosomes, which resulted in the deterioration of eNOS Ser-1177 phosphorylation and NO production. Angiotensin II-induced ROS decreased the bioavailability of eNOS under the FC-enriched condition.
  • Lars P Bechmann, Diana Vetter, Junichi Ishida, Rebekka A Hannivoort, Ursula E Lang, Peri Kocabayoglu, M Isabel Fiel, Ursula Muñoz, Gillian L Patman, Fengxia Ge, Shoshana Yakar, Xiaosong Li, Loranne Agius, Young-Min Lee, Weijia Zhang, Kei Yiu Hui, Despina Televantou, Gary J Schwartz, Derek LeRoith, Paul D Berk, Ryozo Nagai, Toru Suzuki, Helen L Reeves, Scott L Friedman
    Journal of hepatology 58(5) 1000-6 2013年5月  査読有り
    BACKGROUND & AIMS: Dysregulated glucose homeostasis and lipid accumulation characterize non-alcoholic fatty liver disease (NAFLD), but underlying mechanisms are obscure. We report here that Krüppel-like factor 6 (KLF6), a ubiquitous transcription factor that promotes adipocyte differentiation, also provokes the metabolic abnormalities of NAFLD by post-transcriptionally activating PPARα-signaling. METHODS: Mice with either hepatocyte-specific depletion of KLF6 ('ΔHepKlf6') or global KLF6 heterozygosity (Klf6+/-) were fed a high fat diet (HFD) or chow for 8 or 16 weeks. Glucose and insulin tolerance tests were performed to assess insulin sensitivity. Overexpression and knockdown of KLF6 in cultured cells enabled the elucidation of underlying mechanisms. In liver samples from a cohort of 28 NAFLD patients, the expression of KLF6-related target genes was quantified. RESULTS: Mice with global- or hepatocyte-depletion of KLF6 have reduced body fat content and improved glucose and insulin tolerance, and are protected from HFD-induced steatosis. In hepatocytes, KLF6 deficiency reduces PPARα-regulated genes (Trb3, Pepck) with diminished PPARα protein but no change in Pparα mRNA, which is explained by the discovery that KLF6 represses miRNA 10b, which leads to induction of PPARα. In NAFLD patients with advanced disease and inflammation, the expression of miRNA 10b is significantly downregulated, while PEPCK mRNA is upregulated; KLF6 mRNA expression also correlates with TRB3 as well as PEPCK gene expression. CONCLUSIONS: KLF6 increases PPARα activity, whereas KLF6 loss leads to PPARα repression and attenuation of lipid and glucose abnormalities associated with a high fat diet. The findings establish KLF6 as a novel regulator of hepatic glucose and lipid metabolism in fatty liver.
  • Ryozo Nagai
    European heart journal 34(18) 1314-5 2013年5月  査読有り
  • Atsuko Nakayama, Hiroyuki Morita, Jiro Ando, Hideo Fujita, Hiroshi Ohtsu, Ryozo Nagai
    Heart and Vessels 28(3) 292-300 2013年5月  査読有り
    Recent clinical studies reported the drug interaction between proton-pump inhibitors (PPI) and clopidogrel, which remains controversial. The aim of this study was to determine whether the concurrent use of PPI with clopidogrel or ticlopidine is associated with increased risk for adverse cardiovascular outcomes in patients with coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI). In this retrospective cohort study, we assessed the cardiovascular outcomes associated with the concurrent use of PPI and clopidogrel or ticlopidine in the well-characterized 1286 patients with CAD undergoing PCI in the University of Tokyo Hospital. In the Japanese patients with CAD undergoing PCI, the concurrent use of PPI was significantly associated with increased risk for major adverse cardiovascular events in the ticlopidine users (hazard ratio 2.63 95 % confidence interval 1.65-4.18 P &lt 0.001), but not in the clopidogrel users. In the clopidogrel users as well as the ticlopidine users, PPI use did not affect the occurrence of target lesion revascularization, but significantly increased the risk for new lesion formation in the coronary arteries, which required subsequent revascularization. The adverse cardiovascular effects of the concurrent use of PPI and ticlopidine were identified in the patients with CAD undergoing PCI. Also, new lesion formation in the coronary arteries was shown to be increased when PPI was coprescribed for the thienopyridine users. © 2012 Springer.
  • Hiroshi Okamoto, Masatsugu Hori, Masunori Matsuzaki, Hiroyuki Tsutsui, Tsutomu Yamazaki, Ryozo Nagai, Tsutomu Yoshikawa, Yasushi Fujio, Shinpei Nonen, Junichi Azuma, Tohru Izumi, Yasuo Ohashi, Akira Kitabatake
    International Journal of Cardiology 164(2) 238-244 2013年4月5日  査読有り
    AbstractBackground In chronic heart failure (CHF), it remains unclear whether the minimal dose of beta-blockade is related to survival benefits and which parameter predicts morbidity and mortality. We sought to determine the minimal dose related to survival benefits by comparing the efficacy and safety of three doses of carvedilol and the best predictive parameter for effective outcomes in Japanese patients with CHF. Methods In this prospective, randomized, stratified trial, 364 patients with mild to moderate CHF were assigned to a daily carvedilol dose of 2.5, 5, or 20 mg, plus optimal standard therapy. Findings During the mean 3-year follow-up, resting heart rate (HR) and BNP were significantly reduced with dose-response relations in the early period but without dose-response relations in the late period. The LVEF and the LVDd were increased and decreased, respectively, without a dose-response relation. No significant difference was seen in the composite primary endpoint of all-cause mortality and hospitalization for cardiovascular diseases and heart failure. Multivariate analysis indicated early decreases in HR and BNP predicted long-term outcomes. However, adverse events increased dose-dependently. Among 237 polymorphisms in 87 heart failure-related genes, the osteopontin G-156 del genotype was associated with an event-free survival rate (Wilcoxon test, P = 0.030). Conclusions A low carvedilol dose is effective if the HR and/or plasma BNP has been reduced. Carvedilol therapy should be guided by reductions in HR and/or BNP, especially by initial HR reduction, but not only by its dose. OPN might be a surrogate genetic marker for long-term event-free survival. © 2012 Elsevier Ireland Ltd.
  • 中山 敦子, 森田 啓行, 小室 一成, 永井 良三
    日本臨床分子医学会学術総会プログラム・抄録集 50回 58-58 2013年4月  
  • Fukuda Shota, Shimada Kenei, Fujita Masatoshi, Yoshiyama Minoru, Yoshikawa Junichi, Kohro Takahide, Hayashi Dobun, Yamazaki Tsutomu, Nagai Ryozo
    Circulation Journal 77(Suppl.I) 259-259 2013年3月  
  • Teruhiko Imamura, Koichiro Kinugawa, Masaru Hatano, Naoko Kato, Shun Minatsuki, Hironori Muraoka, Toshiro Inaba, Hisataka Maki, Taro Shiga, Atsushi Yao, Shunei Kyo, Minoru Ono, Ryozo Nagai
    Journal of Artificial Organs 16(1) 101-104 2013年3月  査読有り
    No medical treatment has been established to ameliorate pulmonary hypertension (PH) due to left heart disease. Heart transplantation (HTx) is thus far the definitive therapy for stage D heart failure, but concomitant PH is one of the major risk factors for death after HTx. Recently, implantation of a left ventricular assist device (LVAD) has been reported to improve PH and has become a major bridge tool for HTx. We experienced a rare case with persistent PH even after the implantation of a continuous-flow LVAD. The administration of an endothelin receptor antagonist, bosentan, significantly decreased pulmonary vascular resistance. Combination therapy with LVAD implantation and anti-PH medication may be useful for patients with stage D heart failure complicated with severe PH. © 2012 The Japanese Society for Artificial Organs.
  • Norihiko Ashigaki, Jun-Ichi Suzuki, Masahito Ogawa, Ryo Watanabe, Norio Aoyama, Naho Kobayashi, Tomoya Hanatani, Asuka Sekinishi, Hirofumi Zempo, Yuko Tada, Chisato Takamura, Kouji Wakayama, Yasunobu Hirata, Ryozo Nagai, Yuichi Izumi, Mitsuaki Isobe
    American journal of physiology. Heart and circulatory physiology 304(5) H740-8-H748 2013年3月1日  査読有り
    Periodontitis is one of the most common infections in humans. Recently, published reports assert that periodontitis is associated with cardiovascular disease. Although it is said that viral, bacterial infections and autoimmune diseases may be the cause of myocarditis, the pathogenesis of it remains unclear. The aim of this study was to investigate the influence of a periodontal pathogen on experimental autoimmune myocarditis (EAM). Porphyromonas gingivalis (P.g.), PBS as a control, were injected into the mice. Histopathological and immunohistochemical analyses were performed. We examined heart mRNA levels using quantitative RT-PCR. The anti-P.g. IgG antibody level in plasma samples of the P.g.-injected group significantly increased compared with the PBS-injected group. Histopathological analysis detected that the myocarditis-affected areas and the fibrotic area in the P.g.-injected EAM group significantly increased compared with the PBS-injected EAM group (P < 0.05). Immunohistochemical analysis detected that more CD11b-positive cells were shown in the heart of the P.g.-injected EAM group compared with the PBS EAM-injected group (P < 0.05). Hearts from the P.g.-injected EAM group showed significantly increased expression of monocyte chemoattractant protein-1, IFN-γ, and matrix metalloproteinase-9 (MMP-9) mRNA compared with the hearts from the PBS-injected EAM group (P < 0.05). On day 7, serum levels of IL-6 were significantly enhanced in the P.g.-injected EAM group compared with the PBS-injected EAM group (P < 0.05). These results showed that P.g. injection could deteriorate EAM in mice through CD11b-positive cells, cytokines, and MMP-9 expression.
  • Jun-Ichi Okada, Teruyoshi Sasaki, Takumi Washio, Hiroshi Yamashita, Taro Kariya, Yasushi Imai, Machiko Nakagawa, Yoshimasa Kadooka, Ryozo Nagai, Toshiaki Hisada, Seiryo Sugiura
    PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY 36(3) 309-321 2013年3月  査読有り
    Background Recent studies, supported by advances in computer science, have successfully simulated the excitation and repolarization processes of the heart, based on detailed cell models of electrophysiology and implemented with realistic morphology. Methods In this study, we extend these approaches to simulate the body surface electrocardiogram (ECG) of specific individuals. Patient-specific finite element models of the heart and torso are created for four patients with various heart diseases, based on clinical data including computer tomography, while the parallel multi-grid method is used to solve the dynamic bi-domain problem. Personalization procedures include demarcation of nonexcitable tissue, allocation of the failing myocyte model of electrophysiology, and modification of the excitation sequence. In particular, the adjustment of QRS morphology requires iterative computations, facilitated by the simultaneous visualization of the propagation of excitation in the heart, average QRS vector in the torso, and 12-lead ECG. Results In all four cases we obtained reasonable agreement between the simulated and actual ECGs. Furthermore, we also simulated the ECGs of three of the patients under bi-ventricular pacing, and once again successfully reproduced the actual ECG morphologies. Since no further adjustments were made to the heart models in the pacing simulations, the good agreement provides strong support for the validity of the models. Conclusions These results not only help us understand the cellular basis of the body surface ECG, but also open the possibility of heart simulation for clinical applications. (PACE 2013; 36:309-321)
  • Yumiko Yamamoto, Toshihiro Morita, Tomofumi Tanaka, Kenichi Ikeda, Hironobu Kikuchi, Gaku Oguri, Fumitaka Nakamura, Toshiaki Nakajima, Ryozo Nagai
    European journal of pharmacology 701(1-3) 14-9 2013年2月15日  査読有り
    There is a possibility thrombus formation is closely involved in sudden cardiac death. Amiodarone, a potassium channel inhibitor, is known to reduce mortality in patients with coronary artery disease or low ejection fraction, having antithrombotic actions. Using human monocytic THP-1 cells, we investigated the effects of amiodarone on tissue factor mRNA and protein expression. The involvement of the two main potassium channels existing in THP-1 cells was also investigated. Amiodarone (10μM) significantly and almost completely inhibited the increase of tissue factor mRNA and protein expression induced by tumor necrosis factor-α (100ng/ml). The inhibitory effects of amiodarone on tissue factor mRNA expression showed dose-dependency. Margatoxin (1nM), a selective blocker of voltage-dependent potassium channel Kv1.3, also inhibited tissue factor protein expression, but didn't significantly inhibit mRNA expression. Ba(2+), a blocker of inwardly rectifying potassium channel Kir2.1, partly inhibited the increase of tissue factor mRNA and protein expression. This is the first study that shows amiodarone inhibits tissue factor expression in monocytic cells, by inhibiting mRNA transcription. The result may correlate with the facts amiodarone has antithrombotic actions in patients under extraordinary conditions where thrombus formation is enhanced. The inhibitory effects of amiodarone on tissue factor expression are drastic, different from those of margatoxin and Ba(2+). The result suggests amiodarone has an underlying mechanism to intensely inhibit tissue factor expression other than blocking Kv1.3 and Kir2.1.
  • Aiko Sakamoto, Mitsuhiro Fujishiro, Kazuhiko Koike, Ryozo Nagai, Nobukazu Ishizaka
    Journal of Cardiology 61(2) 181-185 2013年2月  査読有り
    Background: Although gastrointestinal (GI) complications are receiving more attention in cardiovascular patients owing to the widespread use of antithrombotic drugs, information seems to be limited over the prevalence of GI malignancies in those patients. Methods and results: The prevalence of malignant as well as non-malignant GI lesions diagnosed in cardiology inpatients was investigated. We retrospectively analyzed 274 cardiology inpatients who underwent upper and/or lower GI tract endoscopies. A total of 97 patients (35.4%) were taking multiple antithrombotic drugs and the mean number of antithrombotic drugs used was 1.19. Malignant neoplasm was found in 26 patients (9.5%), and non-malignant lesions (ulcers, adenomas, polyps) were found in 106 patients (38.7%). Multivariate analysis showed that antiplatelet drug usage was negatively (odds ratio [OR] 0.38, 95% confidence interval [CI] 0.16-0.91) whereas positive fecal occult blood test was positively (OR 4.44, 95% CI 1.44-13.66) associated with GI malignancies. On the other hand, for non-malignant GI lesions, both antiplatelet drug usage (OR 1.85, 95% CI 1.05-3.25) and positive fecal occult blood test (OR 1.99, 95% CI 1.14-3.47) were found to be positive predictors. Conclusions: During the 59-month study period, 26 and 106 patients were diagnosed to have GI malignancies and non-malignant GI lesions, respectively, among cardiology inpatients. Cardiology physicians should not overlook the possibility of GI malignancies in an era of multiple antithrombotic drug usage. © 2012 Japanese College of Cardiology.
  • Jun-Ichi Suzuki, Masahito Ogawa, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    Recent Advances in Adhesions Research 123-128 2013年1月  
    Although 100,000 cardiac transplants have been performed, rejection is still a serious problem. Several adhesion molecules play a critical role in the progression of rejection. Recent investigations have proved some promising methodologies targeting cell adhesion molecules for preventing or treating inflammatory diseases. Although neutralizing antibodies are known to be an effective treatment in cardiovascular diseases, their effect on cardiac transplantation is to be elucidated. In this review article, we described some promising methodologies that use blocking cell adhesion molecules to prevent cardiac rejection. © 2013 by Nova Science Publishers, Inc. All rights reserved.
  • Jun-ichi Suzuki, Mitsuaki Isobe, Yasunobu Hirata, Ryozo Nagai
    Green Tea: Varieties, Production and Health Benefits 101-108 2013年1月  
    Green tea catechins have many biological functions, including anti-oxidative, antiinflammatoryand anti-carcinogenic effects. Anti-oxidative effects of green tea catechinsare characterized by the ability to inhibit free radicalgeneration and scavenge freeradicals. They also influence activation oftranscription factors such as nuclear factorkappaB, a multipotential promoter of inducible nitric oxide synthase and adhesionmolecules. However, anti-oxidative effects of catechins on cardiovascular diseases havenot yet been well investigated. In this article, we reviewed recent clinical andexperimental papers to reveal the anti-oxidative effects of green tea catechins oncardiovascular diseases. In our laboratory, we administered green tea catechins intoanimal models of myocardial ischemia, myocarditis and cardiac transplantation to revealthe effects on the oxidative stress-induced pathological remodeling. From our results andother investigations, green tea catechins are potent agents for the treatment andprevention of oxidative stress-induced cardiovascular diseases because they are criticallyinvolved in the suppression of the stress. © 2013 by Nova Science Publishers, Inc. All Rights Reserved.
  • Sugiura Seiryo, Washio Takumi, Okada Jun-ichi, Watanabe Hiroshi, Yamashita Hiroshi, Kariya Taro, Imai Yasushi, Nagai Ryozo, Kadooka Yoshimasa, Hosoi Akira, Watanabe Masahiro, Hirahara Takao, Yamazaki Takashi, Iwamura Takashi, Nakagawa Machiko, Hatanaka Kohei, Yoneda kazunori, Hisada Toshiaki
    生体医工学 51 M-61-M-61 2013年  
  • Jun-ichi Suzuki, Masahito Ogawa, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    Tea in Health and Disease Prevention 1261-1272 2013年  査読有り
  • Naoko Kato, Koichiro Kinugawa, Etsuko Nakayama, Akiko Hatakeyama, Takako Tsuji, Yumiko Kumagai, Issei Komuro, Ryozo Nagai
    International heart journal 54(4) 228-33 2013年  査読有り
    Knowledge about their own condition is important for patients with heart failure (HF). No valid, reliable, and easily administered instrument is available to measure this knowledge in clinical practice. In this study, a HF knowledge scale was developed, and its psychometric properties were tested. Items related to knowledge about HF were extracted from relevant guidelines. Content validity of the items was confirmed by an expert panel including a cardiologist and nurses specialized in treatment and care of patients with HF. A self-administered questionnaire was then distributed to 187 patients with HF (64.0 ± 12.1 years, males 69%). In 62% patients, a left ventricular ejection fraction of < 50% was identified. Exploratory factor analysis demonstrated the one-dimensionality of the 15-item HF knowledge scale. Mean score was 10.7 ± 3.0 (range, 0-15). Known-group validity testing revealed a significant difference in HF knowledge score between patients newly diagnosed with HF and patients experienced with HF (9.4 ± 3.2 versus 10.8 ± 2.9, P = 0.043). In addition, HF knowledge scale scores were correlated with HF self-care scores assessed by the European Heart Failure Self-Care Behavior Scale for evaluation of criterion validity (ρ = -0.304, P < 0.001). Cronbach's alpha was 0.79, and item-total correlation was 0.22-0.51, thereby suggesting that the reliability of the scale was acceptable. Acceptable validity and reliability were demonstrated for the HF knowledge scale developed in this study. This instrument could be useful in evaluation of patient knowledge about HF.
  • Yumiko Hosoya, Masafumi Watanabe, Masahiro Terashima, Eisuke Amiya, Tomoko Nakao, Akiko Hasegawa, Hironobu Hyodo, Jiro Ando, Tomoyuki Fujii, Ryozo Nagai, Issei Komuro
    International heart journal 54(2) 119-22 2013年  査読有り
    Amniotic fluid embolism (AFE) is a rare but devastating complication of pregnancy. Acute circulatory failure and obstetric disseminated intravascular coagulopathy are often associated with AFE and lead to poor prognosis of this syndrome. Although many reports of AFE and its cardiopulmonary complications exist, their etiology remains unknown. Classically, it was believed that the fatal cardiopulmonary complication in AFE is due to acute and severe pulmonary hypertension caused by critical obstruction of the pulmonary vessels by embolized amniotic fluid. However, recent hypotheses are suggesting that anaphylactic reaction or a cytokine effect induced by amniotic fluid is the main pathophysiological mechanism. We report a case in which cardiac magnetic resonance imaging was performed at the chronic stage of AFE. Late gadolinium enhancement (LGE) was detected at the mid-wall of the left ventricle with no evidence of pulmonary hypertension. This finding suggests that the pathophysiological mechanism of severe cardiac complications in AFE may include direct left ventricular myocardial injury through an immune reaction or cytokine release, rather than pulmonary embolism.
  • Naoko Kato, Koichiro Kinugawa, Teruhiko Imamura, Hironori Muraoka, Shun Minatsuki, Toshiro Inaba, Hisataka Maki, Taro Shiga, Masaru Hatano, Atsushi Yao, Issei Komuro, Ryozo Nagai
    Circulation Journal 77(4) 1001-1008 2013年  査読有り
    Background: The aim of this study was to examine trends of clinical outcome and to clarify surrogate markers when titrating β-blocker in heart failure patients with reduced left ventricular ejection fraction (HFrEF, LVEF &lt 50%). Methods and Results: Consecutive HFrEF patients starting on β-blocker were divided into 2 groups according to time of dose fixation attainment: before 31 December 2005 (group 1, n=108) or after 1 January 2006 (group 2, n=119). There were no significant differences in patient characteristics between the 2 groups at baseline. Betablocker fixed dose was higher with lower resting heart rate in group 2 (6.2±5.7 mg/day vs. 9.5±9.1 mg/day in carvedilol equivalent dose, P=0.001 74.2±11.1 beats/min vs. 70.2±9.7 beats/min, P=0.004). The rate of HF hospitalization and/ or all-cause death after 36 months was lower in group 2 than in group 1 (22% vs. 38%, P=0.011 hazard ratio, 0.90 P=0.012). Cox regression analysis showed that β-blocker ≥10 mg/day and achieved heart rate ≤71 beats/min predicted a better outcome (both P&lt 0.05). Conclusions: Recent improvement of clinical outcome among HFrEF patients may be attributable to the up-titration policy accompanying lowered heart rate. Resting heart rate ≤71 beats/min and β-blocker ≥10 mg/day (ie, 50% of the target dose for Japanese patients) could be surrogate markers when titrating β-blocker.
  • Teruhiko Imamura, Koichiro Kinugawa, Taro Shiga, Naoko Kato, Hironori Muraoka, Shun Minatsuki, Toshiro Inaba, Hisataka Maki, Masaru Hatano, Atsushi Yao, Shunei Kyo, Ryozo Nagai
    Circulation Journal 77(2) 397-404 2013年  査読有り
    Background: A newly-developed vasopressin type 2 receptor antagonist, tolvaptan (TLV), has a unique feature of diuresis, but the response to this drug can be unpredictable. Methods and Results: Data were collected from hospitalized patients with decompensated congestive heart failure who were administered TLV at 3.75-15 mg/day (n=61). A responder/non-responder to TLV was determined as having any increase/decrease in urine volume (UV) during the next 24 h after TLV treatment on the first day. Logistic regression analyses for increases in UV were performed, and independent predictors of the responder were the following: C1, baseline urine osmolality (U-OSM) &gt 352 mOsm/L and C2, %decrease in U-OSM &gt 26% at 4-6 h after TLV administration. Criteria consisting of C1 and C2 had a good predictability for responders by receiver-operating characteristic analysis (area under the curve=0.960). Kidneys of the non-responders no longer had diluting ability (%decrease of U-OSM at 4-6 h=2.7±14.6%*), but also barely kept concentrating ability (baseline U-OSM=296.4±68.7* mOsm/L) with markedly reduced estimated glomerular filtration ratio (35.5±29.4 ml · min-1 · 1.73 m-2*) (*P&lt 0.05 vs. patients who had at least 1 positive condition [n=42]). Conclusions: More than 26% decrease in U-OSM from a baseline &gt 352 mOsm/L for the first 4-6 h predicts responders to TLV. Unresponsiveness to TLV is attributable to nephrogenic diabetes insipidus complicated by chronic renal disease.
  • Toshiro Inaba, Atsushi Yao, Tomoko Nakao, Masaru Hatano, Hisataka Maki, Teruhiko Imamura, Taro Shiga, Tadashi Yamazaki, Makoto Sonoda, Koichiro Kinugawa, Takahiro Shiota, Junichi Suzuki, Katsu Takenaka, Yasunobu Hirata, Ryozo Nagai
    Circulation journal : official journal of the Japanese Circulation Society 77(1) 198-206 2013年  査読有り
    BACKGROUND: Non-invasive assessment of volume and function on the right ventricle (RV) for pulmonary hypertension (PH) is limited. METHODS AND RESULTS: Patients with PH (n=23) underwent 3-dimensional (D) echocardiography (3DECHO), with cardiac magnetic resonance imaging to confirm its precision, and right heart catheterization. On linear regression analysis the RV end-systolic volume index (ESVI) was positively correlated with pulmonary vascular resistance (PVR) and mean pulmonary arterial pressure (mPAP; R=0.42 and 0.46, P=0.03 and 0.03, respectively). The RV end-diastolic volume index (EDVI) was positively correlated with mPAP (R=0.41, P<0.05). The left ventricular (LV) EDVI was inversely correlated with PVR (R=-0.48, P=0.02). The RV ejection fraction was inversely correlated with PVR and mean right atrial pressure (mRAP; R=-0.57, and -0.45, P=0.004, and 0.03, respectively). RVEDVI/LVEDVI and RVESVI/LVESVI (the diastolic and systolic remodeling indices, respectively) had a significantly positive linear relationship with PVR (R=0.67 and 0.55, P=0.0005 and 0.006, respectively), and the former had a significantly positive linear relationship with mRAP (R=0.42, P<0.05). During the recovery process in 1 specific case, the remodeling indices maintained a significant linear relationship with the hemodynamic parameters. CONCLUSIONS: Novel indices provided by 3DECHO may be utilized as alternative indicators of hemodynamic changes in PH patients.
  • Naoko Kato, Koichiro Kinugawa, Etsuko Nakayama, Takako Tsuji, Yumiko Kumagai, Teruhiko Imamura, Hisataka Maki, Taro Shiga, Masaru Hatano, Atsushi Yao, Chikako Miura, Issei Komuro, Ryozo Nagai
    International heart journal 54(6) 382-9 2013年  査読有り
    Self-care is a cornerstone for the successful management of heart failure (HF). The purpose of this study was to examine the impacts of HF self-care on prognosis in Japanese patients with HF. A total of 283 HF outpatients (age 64 ± 14, 70% male, 52% HFrEF) were enrolled. We asked patients to answer about their adhevence to 5 self-care behaviors (medication, eating a low-sodium diet, regular exercise, daily weight check, and treatment seeking behavior). On the basis of the results, we classified patients into a good self-care group and a poor self-care group. The primary outcome was HF hospitalization and/or cardiac death. In total, 65% of patients were classified into the poor self-care group. During a median follow-up of 2 years, cardiac events occurred more frequently in the poor self-care group (22% versus 9.6%, P = 0.013). Poor self-care was an independent risk factor for cardiac events in Cox regression analysis adjusted for clinical parameters (hazard ratio = 2.86, P = 0.005). Poor self-care was also associated with an increased number of HF hospitalizations as well as an extended length of hospital stay for HF. Poor knowledge about HF was an independent determinant for poor self-care in multivariate logistic regression analysis (odds ratio = 0.92, P = 0.019). Insufficient self-care is an independent risk factor for cardiac events in Japanese patients with HF.
  • Tatsuya Asanuma, Yasutomi Higashikuni, Hiroshi Yamashita, Ryozo Nagai, Toshiaki Hisada, Seiryo Sugiura
    International heart journal 54(1) 54-8 2013年  査読有り
    Simulation studies have been performed in attempts to elucidate the signifi cance of shear and tissue stresses in the progression and rupture of coronary artery plaques, but few studies have analyzed both stresses simultaneously. We analyzed the distributions of shear stress and tissue stress in a model of coronary artery plaque based on intravascular ultrasound data by fluid-structure interaction finite element analysis under physiological pressure and flow. As shown in previous studies, the region of peak shear stress was observed at the proximal side of the plaque where flow velocity was high but its value was at most 10 Pa. On the other hand, 1000-10,000 times greater tissue stress was located in the stenotic region but the location of peak tissue stress was different from that of shear stress. We also found that stenting not only stabilizes the stented segment but also reduces the stress in the adjacent region. Fluid-structure interaction analysis revealed discordance in the distribution of shear and tissue stresses. These two stresses exert distinct influences on the coronary plaque, rupture of which may occur where tissue stress exceeds the plaque strength, which is weakened by pathological processes triggered by shear stress.
  • Toru Suzuki, Eduardo Bossone, Daigo Sawaki, Rolf Alexander Jánosi, Raimund Erbel, Kim Eagle, Ryozo Nagai
    American heart journal 165(1) 15-25 2013年1月  査読有り
    The development of diagnostic biomarkers of acute cardiovascular disease remains an important topic of interest given potential use to aid in early diagnosis. Cardiac biomarkers of ischemia and heart failure have already proven to be clinically useful. Biomarkers of aortic diseases are also needed, especially for life-threatening conditions such as aortic dissection. In this review, we discuss the present status of the development of biomarkers of aortic diseases. Although aortic dissection has been most vigorously pursued, there has also been notable recent progress in biomarkers of aneurysms and inflammatory aortic disease.
  • Naomi Ogawa, Yasushi Imai, Hiroshi Nishimura, Masayoshi Kato, Norifumi Takeda, Kan Nawata, Tsuyoshi Taketani, Tetsuro Morota, Shinichi Takamoto, Ryozo Nagai, Yasunobu Hirata
    International heart journal 54(1) 23-6 2013年  査読有り
    Marfan syndrome (MFS) is an inherited connective tissue disorder mainly caused by the fibrillin-1 mutation. Deficient fibrillin-1 is thought to result in the failed sequestration of transforming growth factor β (TGFβ) and subsequent activation of the TGFβ signaling pathway, suggesting that the circulating TGFβ level may be elevated in MFS, although its accurate measurement is complex due to ex vivo release from platelet stores upon platelet activation. We measured the plasma TGFβ1 levels of 32 Japanese MFS patients (22 medically untreated, 10 treated, 20 males, 30.1 ± 9.6 years old) and 30 healthy volunteers (19 males, 29.5 ± 5.8 years old) by ruthenium-based electrochemiluminescence platform (ECL). PF4 was also measured by enzyme immunoassay (EIA) as a platelet degranulation marker. There was no significant difference in the mean plasma TGFβ1 level between the MFS group (1.31 ± 0.40 ng/mL) and controls (1.17 ± 0.33 ng/mL) (P = 0.16, NS). Also, there was no significant difference between the untreated (1.24 ± 0.37 ng/mL) and treated (1.46 ± 0.45 ng/mL) MFS patients (P = 0.15, NS). We also measured PF4, which showed wide deviations but no significant difference between the two groups (P = 0.50). A difference in circulating TGFβ1 levels between MFS patients and controls was not detected in this Japanese population. Circulating TGFβ1 is not a diagnostic and therapeutic marker for Japanese MFS patients, although our findings do not eliminate the possible association of TGFβ with the pathogenesis of MFS.
  • Aiko Sakamoto, Yuko Ishizaka, Minoru Yamakado, Kazuhiko Koike, Ryozo Nagai, Nobukazu Ishizaka
    JOURNAL OF ATHEROSCLEROSIS AND THROMBOSIS 20(2) 142-151 2013年  査読有り
    Aim: Serum gamma-glutamyltransferase (GGT) levels, which are associated with insulin resistance, may predict the incidence of cardiovascular disease and mortality. Here, the relationship was analyzed between changes in obesity parameters and those in serum GGT over a one-year period. Methods: Data were analyzed from individuals who underwent general health screening two years running. Results: Among 3086 individuals (1954 men, 1132 women), percent changes in both waist circumference (%dWC) and body mass index (BMI) (%dBMI) were significantly correlated with percent changes in GGT (%dGGT) in men (r = 0.17 and r = 0.31, respectively). On the other hand, in women, %dBMI, but not %dWC, had a significant association with %dGGT. When age, %dWC, %dBMI, smoking status, and alcohol intake were all included as independent variables, %dBMI, but not %dWC, showed a graded association with the highest %dGGT quartile in both genders. Furthermore, incorporation of %dWC as an additional independent variable to age, gender, and %dBMI did not show an incremental improvement in prediction for the highest %dGGT quartile (C statistic, 0.643 to 0.648; p = 0.380), suggesting that taking WC changes into account does not significantly improve the prediction of GGT changes when BMI has already been taken into consideration. Conclusion: Changes in BMI are dose-dependently associated with GGT changes in both genders; however, the additional consideration of changes in WC does not show a significant statistical improvement in the prediction of GGT changes.
  • Teruhiko Imamura, Koichiro Kinugawa, Taro Shiga, Miyoko Endo, Naoko Kato, Toshiro Inaba, Hisataka Maki, Masaru Hatano, Atsushi Yao, Takashi Nishimura, Yasunobu Hirata, Shunei Kyo, Minoru Ono, Ryozo Nagai
    Circulation journal : official journal of the Japanese Circulation Society 77(1) 96-104 2013年  査読有り
    BACKGROUND: It is often difficult to predict reversibility of liver or renal function after left ventricular assist device (LVAD) implantation in patients with stage D heart failure. METHODS AND RESULTS: Data were obtained for 69 patients who had received a LVAD (18 continuous-flow, 51 pulsatile). Persistent hepatic or renal dysfunction was defined as levels of total bilirubin (TB) or creatinine (Cre) >1.5mg/dl at 6 months after LVAD implantation. TB score or Cre score was calculated: 0.15 × age+1.1 × (preoperative TB) or 0.2 × age+3.6 × (preoperative Cre), in which coefficients were determined on the basis of odds ratios for persistent hepatic or renal dysfunction, respectively. Receiver-operating characteristics analyses showed good predictabilities for persistent end-organ dysfunction (area under curve: 0.794 for TB score and 0.839 for Cre score). High-risk strata of TB score (>11.0 points) or Cre score (>14.1 points) were associated with persistently higher levels of TB or Cre (TB, 1.32 ± 0.51; Cre, 1.23 ± 0.41 mg/dl; both P<0.001 vs. low-risk strata). CONCLUSIONS: Reversibility of end-organ function with LVAD implantation can be well predicted by our new risk scoring system that consists of the preoperative TB or Cre level adjusted by the patient's age. The scoring system would be beneficial, especially in considering the indication of a bridge to candidacy.
  • Atsuko Nakayama, Masao Takahashi, Kazuyoshi Hina, Katsuhito Fujiu, Hiroaki Sugiyama, Toshiya Kojima, Jiro Ando, Yasushi Imai, Yasunobu Hirata, Ryozo Nagai
    International heart journal 54(2) 111-4 2013年  査読有り
    Although hypertrophic cardiomyopathy (HCM) with an accessory pathway is encountered in clinical practice, there is little evidence of a coherent strategy for ablation of the accessory pathway in patients with HCM. We present the case of a 61-year-old man who had type B Wolff-Parkinson-White (WPW) syndrome with hypertrophic obstructive cardiomyopathy (HOCM). Due to paroxysmal atrial fibrillation, he underwent radiofrequency catheter ablation of the accessory pathway located in the right postero-lateral wall to prevent secondary symptomatic events. His LV dyssynchrony improved after the procedure, but the degree of the LV outflow tract (LVOT) pressure gradient was increased. To stabilize the LVOT pressure gradient, he needed additional medications. This case shows that patients with HOCM should be carefully evaluated before making a decision concerning ablation of the accessory pathway.
  • Ryozo Nagai, Koichiro Kinugawa, Hiroshi Inoue, Hirotsugu Atarashi, Yoshihiko Seino, Takeshi Yamashita, Wataru Shimizu, Takeshi Aiba, Masafumi Kitakaze, Atsuhiro Sakamoto, Takanori Ikeda, Yasushi Imai, Takashi Daimon, Katsuhiro Fujino, Tetsuji Nagano, Tatsuaki Okamura, Masatsugu Hori
    Circulation Journal 77(4) 908-916 2013年  査読有り
    Background: A rapid heart rate (HR) during atrial fibrillation (AF) and atrial flutter (AFL) in left ventricular (LV) dysfunction often impairs cardiac performance. The J-Land study was conducted to compare the efficacy and safety of landiolol, an ultra-short-acting β-blocker, with those of digoxin for swift control of tachycardia in AF/AFL in patients with LV dysfunction. Methods and Results: The 200 patients with AF/AFL, HR ≥120 beats/min, and LV ejection fraction 25-50% were randomized to receive either landiolol (n=93) or digoxin (n=107). Successful HR control was defined as ≥20% reduction in HR together with HR <110 beats/min at 2 h after starting intravenous administration of landiolol or digoxin. The dose of landiolol was adjusted in the range of 1-10 μg · kg-1 · min-1 according to the patient's condition. The mean HR at baseline was 138.2±15.7 and 138.0±15.0 beats/min in the landiolol and digoxin groups, respectively. Successful HR control was achieved in 48.0% of patients treated with landiolol and in 13.9% of patients treated with digoxin (P<0.0001). Serious adverse events were reported in 2 and 3 patients in each group, respectively. Conclusions: Landiolol was more effective for controlling rapid HR than digoxin in AF/AFL patients with LV dysfunction, and could be considered as a therapeutic option in this clinical setting.
  • Yoshihiko Izumida, Naoya Yahagi, Yoshinori Takeuchi, Makiko Nishi, Akito Shikama, Ayako Takarada, Yukari Masuda, Midori Kubota, Takashi Matsuzaka, Yoshimi Nakagawa, Yoko Iizuka, Keiji Itaka, Kazunori Kataoka, Seiji Shioda, Akira Niijima, Tetsuya Yamada, Hideki Katagiri, Ryozo Nagai, Nobuhiro Yamada, Takashi Kadowaki, Hitoshi Shimano
    Nature communications 4 2316-2316 2013年  査読有り
    During fasting, animals maintain their energy balance by shifting their energy source from carbohydrates to triglycerides. However, the trigger for this switch has not yet been entirely elucidated. Here we show that a selective hepatic vagotomy slows the speed of fat consumption by attenuating sympathetic nerve-mediated lipolysis in adipose tissue. Hepatic glycogen pre-loading by the adenoviral overexpression of glycogen synthase or the transcription factor TFE3 abolished this liver-brain-adipose axis activation. Moreover, the blockade of glycogenolysis [corrected] through the knockdown of the glycogen phosphorylase gene and the resulting elevation in the glycogen content abolished the lipolytic signal from the liver, indicating that glycogen is the key to triggering this neurocircuitry. These results demonstrate that liver glycogen shortage activates a liver-brain-adipose neural axis that has an important role in switching the fuel source from glycogen to triglycerides under prolonged fasting conditions.
  • Shogo Watanabe, Eisuke Amiya, Masafumi Watanabe, Munenori Takata, Atsuko Ozeki, Aya Watanabe, Shuichi Kawarasaki, Tomoko Nakao, Yumiko Hosoya, Kazuko Omori, Koji Maemura, Issei Komuro, Ryozo Nagai
    Circulation Journal 77(4) 1018-1025 2013年  査読有り
    Background: Endothelial dysfunction and autonomic nervous system imbalance are both risk markers of atherosclerotic vascular damage. The relationship between these 2 factors, however, has not been clarified concisely. Methods and Results: Flow-mediated dilation (FMD) was measured in 47 patients with ischemic heart disease (IHD mean age, 68.1±7.1 years) using an ultrasound semi-automatic measuring system (UNEXEF18G), and autonomic nervous system activity was evaluated by simultaneous measurements of heart rate variability. FMD was significantly correlated with standard deviation of normal-to-normal beats (r=0.33, P=0.022) and the power ratio of low-frequency power to high-frequency power (LF/HF r=-0.38, P=0.0087). Furthermore, multiple regression analysis indicated that LF/HF was the most important predictor of the magnitude of FMD. This interaction was severely blunted by β-blockers and the presence of diabetes. Moreover, standardized FMD according to autonomic nervous system activity was a better predictor of future cardiovascular events than FMD. Subjects with cardiovascular events had a significantly smaller corrected FMD (event (+), 3.62±0.41 event (-), 5.10±2.35 P=0.001), and the higher corrected FMD was associated with longer event-free survival. Conclusions: Autonomic nervous system activity is an important regulatory factor of FMD in subjects with IHD. Assessment of this interaction can help provide more accurate risk stratification of subjects with IHD.
  • Eisuke Amiya, Masafumi Watanabe, Munenori Takata, Shogo Watanabe, Atsuko Ozeki, Aya Watanabe, Shuichi Kawarasaki, Tomoko Nakao, Yumiko Hosoya, Kazuko Omori, Koji Maemura, Yasunobu Hirata, Ryozo Nagai, Issei Komuro
    Circulation journal : official journal of the Japanese Circulation Society 77(7) 1844-53 2013年  査読有り
    BACKGROUND: Differences in regulating factors and the clinical implications of body temperature variability (BTV) between subjects with and without diabetes have not been clarified to date. METHODS AND RESULTS: In 66 subjects with ischemic heart disease (33 with diabetes and 33 without diabetes), BTV, the difference between the highest and lowest temperature measurements, and body temperature standard deviation (BT SD) were measured from axillary body temperature (ABT) records of 3 consecutive days and followed for 16.4±8.4 months. In subjects without diabetes BTV and BT SD were closely associated with endothelial function as evaluated on flow-mediated dilation (BTV, R=0.33, P=0.026; BT SD, R=0.41, P=0.029), whereas there was a poor association in subjects with diabetes. In the absence of an interrelationship between vascular function and thermoregulation, the contribution of inflammation to BTV was increased in subjects with diabetes (BTV, 0.59±0.21°C for C-reactive protein [CRP] <0.08 mg/dl vs. 0.79±0.28°C for CRP >0.08 mg/dl, P=0.014). Event-free survival analysis showed that in subjects with diabetes higher BT SD was associated with shorter event-free survival (log-rank P=0.012), but this relationship was not found in subjects without diabetes. CONCLUSIONS: In subjects with diabetes, the interrelationship between thermoregulation and vascular function was disrupted and the effect of inflammation on thermoregulation was enhanced, so that BTV had a sufficient predictive value for cardiovascular events in diabetic subjects.
  • Takahide Kohro, Tsutomu Yamazaki, Hiroki Sato, Kenji Harada, Kazuhiko Ohe, Issei Komuro, Ryozo Nagai
    International Heart Journal 54(2) 93-97 2013年  査読有り
    There have been few reports concerning the trends in antidiabetic drug use in Japan. In 2009, a dipeptidyl peptidase- 4 inhibitor (DPP4I), an antidiabetic with a new mechanism of action, was made available. This study was conducted to analyze the antidiabetic prescription trends in Japan in recent years and the influence of DPP4Is on those trends. We used monthly claims data obtained from a database company. Data from patients 20 years of age or older and who were prescribed antidiabetics were extracted and analyzed. A total of 18,457 patients were prescribed antidiabetics (mean age, 53.6 ± 11.0). The sulfonylurea prescription rate decreased while that of biguanides increased. After the introduction of DPP4Is, use of these agents rapidly increased and the rate further increased one year after DPP4I introduction. DPP4Is also became the most prescribed antidiabetics for those prescribed antidiabetics for the first time. The decrease in the use of sulfonylureas and the increase in the use of biguanides are in accordance with trends observed in the United States and Europe, and probably reflect Japanese physicians' awareness of cumulating evidence gained from studies such as the UK Prospective Diabetes Study (UKPDS). The rapid increase in the DPP4I prescription rate might be the result of several factors including their safety profiles, which were highlighted in clinical studies published just prior to the drugs becoming available. However, there is little data regarding the efficacy of DPP4Is in reducing diabetes related complications, which should be determined in future studies.
  • Tetsu Tanaka, Masahito Ogawa, Jun-ichi Suzuki, Asuka Sekinishi, Akiko Itai, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    American journal of physiology. Heart and circulatory physiology 303(12) H1435-45-H1445 2012年12月15日  査読有り
    Pressure overload is known to be a cause of cardiac hypertrophy that often transits to heart failure. Although nuclear factor (NF)-κB is a key factor in the progression of cardiac hypertrophy, its pathophysiology is yet to be elucidated. Thus, we aimed to show that inhibition of NF-κB activation improves pressure overload-induced cardiac dysfunction. To assess the effect of inhibition on NF-κB activation in pressure overload cardiac hypertrophy, we used IMD-1041 in a murine thoracic aortic constriction (TAC) model. IMD-1041 inhibits the phosphorylation of IκB via inhibition of IκB kinase-β. IMD-1041 (100 mg·kg(-1)·day(-1)) or vehicle was administered orally into mice once a day, and mice were euthanized on day 42 after TAC. TAC resulted in left ventricular wall thickening, cardiac dysfunction, and increases of heart and lung weight, whereas IMD-1041 significantly suppressed the development of cardiac hypertropy 6 wk after TAC. Histologically, developed cardiac fibrosis and cardiomyocyte hypertrophy occurred in the vehicle-treated group, whereas IMD-1041 significantly attenuated these changes. IMD-1041 suppressed the expression of p65-positive cells and nuclear translocation of p65 induced by TAC compared with vehicle. Matrix metalloproteinase-2 activity increased in the vehicle + TAC-treated group; however, it was suppressed in the IMD-1041 + TAC-treated group. IMD-1041 treatment from day 28 to day 42 after TAC significantly attenuated the decrease in the percentage of fractional shortening and cardiac fibrosis without an antihypertrophic effect. In conclusion, IMD-1041 may be useful for preventing pressure overload-induced cardiac dysfunction and the transition of cardiac hypertrophy to contraction failure via suppression of NF-κB activation.
  • Teruhiko Imamura, Koichiro Kinugawa, Taro Shiga, Naoko Kato, Miyoko Endo, Toshiro Inaba, Hisataka Maki, Masaru Hatano, Atsushi Yao, Yasunobu Hirata, Masaaki Akahane, Takashi Nishimura, Shunei Kyo, Minoru Ono, Ryozo Nagai
    Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs 15(4) 395-8 2012年12月  査読有り
    For the time being, in Japan, two recently approved implantable ventricular assist devices (VADs) are indicated only when a patient has been listed for heart transplantation or approved to be eligible for heart transplantation by in-hospital committee. The reversibility of end-organ dysfunction must be expected before VAD implantation, but it is often hard to prove during worsening clinical status. We report two patients whose end-organ dysfunction had been eventually demonstrated to be reversible by invasive procedures such as transluminal liver biopsy or transient insertion of intra-aortic balloon pumping.
  • Motoki Inoue, Mariko Takayanagi, Katsuhito Fujiu, Ichiro Manabe, Ryozo Nagai, Tetsushi Taguchi
    Science and technology of advanced materials 13(6) 064208-064208 2012年12月  査読有り
    Tamibarotene-loaded biodegradable matrices with antithrombogenic and drug-releasing properties were prepared in a crosslinking reaction between amino groups of alkali-treated collagen (AlCol) and active ester groups of trisuccinimidyl citrate. The resulting matrices were characterized by their residual amino group concentrations, swelling ratios and thermal, antithrombogenic and drug-releasing properties. It was clarified that the addition of tamibarotene does not inhibit matrix formation. After immersion in water, the swelling ratio of a matrix became lower than that prior to immersion. Thermal analysis indicated that AlCol interacted with tamibarotene. The addition of tamibarotene to the matrix did not influence the antithrombogenic property of the resulting matrix. A matrix with a high crosslinking density had a prolonged tamibarotene elution time. These results demonstrate that tamibarotene-loaded matrices have great potential as a coating material for drug-eluting stents.
  • Katsuhito Fujiu, Ichiro Manabe, Makoto Sasaki, Motoki Inoue, Hiroshi Iwata, Eriko Hasumi, Issei Komuro, Yasuyuki Katada, Tetsushi Taguchi, Ryozo Nagai
    Science and technology of advanced materials 13(6) 064218-064218 2012年12月  査読有り
    SUS316L stainless steel and cobalt-chromium and platinum-chromium alloys are widely used platforms for coronary stents. These alloys also contain nickel (Ni), which reportedly induces allergic reactions in some subjects and is known to have various cellular effects. The effects of Ni on neointima formation after stent implantation remain unknown, however. We developed coronary stents made of Ni-free high-nitrogen austenitic stainless steel prepared using a N2-gas pressurized electroslag remelting (P-ESR) process. Neointima formation and inflammatory responses following stent implantation in porcine coronary arteries were then compared between the Ni-free and SUS316L stainless steel stents. We found significantly less neointima formation and inflammation in arteries implanted with Ni-free stents, as compared to SUS316L stents. Notably, Ni2+ was eluted into the medium from SUS316L but not from Ni-free stainless steel. Mechanistically, Ni2+ increased levels of hypoxia inducible factor protein-1α (HIF-1α) and its target genes in cultured smooth muscle cells. HIF-1α and their target gene levels were also increased in the vascular wall at SUS316L stent sites but not at Ni-free stent sites. The Ni-free stainless steel coronary stent reduces neointima formation, in part by avoiding activation of inflammatory processes via the Ni-HIF pathway. The Ni-free-stainless steel stent is a promising new coronary stent platform.
  • Masahito Ogawa, Jun-Ichi Suzuki, Kiyoshi Takayama, Takaaki Senbonmatsu, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    Laboratory investigation; a journal of technical methods and pathology 92(12) 1766-76 2012年12月  査読有り
    The complex pathophysiological interactions between heart and kidney diseases are collectively known as cardiorenal syndrome. The renin-angiotensin system (RAS) may have a pivotal role in the development of cardiorenal syndrome. The aim of this study was to elucidate the RAS activity responsible for adverse post-infarction remodeling and prognosis in mice with renal failure. To establish the type IV cardiorenal syndrome model, 5/6 nephrectomy (NTX) was performed in a surgical procedure, followed by the induction of myocardial ischemia (MI) by a coronary artery ligation 4 weeks later. NTX and MI resulted in deteriorated left ventricular remodeling and RAS activation, which was improved by an aliskiren that appeared to be independent of renal function and blood pressure (BP). Moreover, MI induced in renin and angiotensinogen double-transgenic (Tg) mice showed comparable effects to MI plus NTX mice, including advanced ventricular remodeling and enhancement of RAS, oxidative stress, and monocytes chemoattractant protein (MCP)-1. Aliskiren suppressed these changes in the MI-induced Tg mice. In in vitro study, Nox2 expression was elevated by the stimulation of plasma from NTX mice in isolated neonatal cardiomyocytes. However, Nox2 upregulation was negated when we administered plasma from aliskiren-treated-NTX mice or isolated cardiomyocytes from AT1-deficient mice. Primary mononuclear cells also showed an upregulation in the expression of Nox2 and MCP-1 by stimulation with plasma from NTX mice. Our data suggest that renal disorder results in ventricular dysfunction and deteriorates remodeling after MI through excessive RAS activation. Moreover, renin inhibition improved the changes caused by cardiorenal syndrome.
  • Jun-ichi Suzuki, Masahito Ogawa, Keiichi Hishikari, Ryo Watanabe, Kiyoshi Takayama, Yasunobu Hirata, Ryozo Nagai, Mitsuaki Isobe
    Cardiovascular therapeutics 30(6) 301-7 2012年12月  査読有り
    Macrolide antibiotics are broadly used for the treatment of various microbial infections. However, they are also known to have multiple biologic effects, such as alteration of inflammatory factors and matrix metalloproteinases (MMPs). Because of controversial results in clinical trials, the effects of macrolides on cardiovascular diseases are still to be elucidated. It has been reported that MMP activity is upregulated in various cardiovascular diseases, such as myocarditis, cardiac transplant rejection and myocardial infarction. However, little is known about the effects of macrolides on cardiovascular diseases. We have reported that clarithromycin suppressed the development of myocarditis, cardiac rejection and myocardial ischemia using animal models. In this article, we reviewed the roles of MMPs in cardiovascular diseases and the effects of macrolides on the prevention of adverse tissue remodeling.
  • Taira Fukuda, Miwa Kurano, Haruko Iida, Haruhito Takano, Tomofumi Tanaka, Yumiko Yamamoto, Kenichi Ikeda, Mika Nagasaki, Koshiro Monzen, Kansei Uno, Masayoshi Kato, Taro Shiga, Koji Maemura, Nobuhito Masuda, Hiroshi Yamashita, Yasunobu Hirata, Ryozo Nagai, Toshiaki Nakajima
    European journal of preventive cardiology 19(6) 1393-400 2012年12月  査読有り
    BACKGROUND: Inflammatory markers such as serum C-reactive protein (CRP), serum amyloid A (SAA), and plasma pentraxin 3 (PTX3), which belong to the pentraxin superfamily, increase due to various inflammatory diseases. Some studies demonstrated that serum CRP and SAA are predictors of cardiovascular diseases, and cardiac rehabilitation (CR) induces anti-inflammatory effects. In the present study, we investigated the effects of CR on pentraxins (serum CRP, SAA, and plasma PTX3) in patients with cardiovascular diseases. METHODS: Fifty patients with cardiovascular diseases [61 ± 13 (mean ± SD) years old, male/female 44/6] participated. Each subject performed CR using aerobic bicycle exercise two or three times per week for 3-6 months. We measured resting serum high-sensitivity CRP (hsCRP), SAA, and plasma PTX3 before and 3 and 6 months after CR, and compared them with VO(2peak) determined using a standard increment cycle ergometer protocol, B-type natriuretic peptide (BNP), and other biochemical data such as HbA1c. RESULTS: There was a significant positive correlation between hsCRP and SAA (r = 0.92, p < 0.001), but no relations between these parameters and PTX3. Plasma PTX3 significantly decreased time dependently during CR (at baseline 3.2 ± 2.0 ng/ml, at 3 months 2.3 ± 0.8 ng/ml, at 6 months 2.1 ± 0.7 ng/ml; all p < 0.05). Serum hsCRP tended to decrease, but not statistically significantly. At baseline, plasma PTX3 was negatively correlated with the percentage of the predicted values of VO(2peak) and positively correlated with BNP. CR significantly increased the percentage of the predicted values of VO(2peak) and decreased BNP. CONCLUSIONS: Plasma PTX3, an inflammatory marker, which was quite different from CRP and SAA, decreased during cardiac rehabilitation with an improvement of exercise capacity in patients with cardiovascular diseases.
  • Tsukasa Inajima, Yasushi Imai, Hiroyuki Morita, Ryozo Nagai, Katsuya Iijima, Shintaro Yanagimoto, Naoki Yahagi, Guillaume Lopez, Masaki Shuzo, Ichiro Yamada
    Journal of Robotics and Mechatronics, Special Issue on “Medical Science and Engineering Cooperation” 24(5) 1-9 2012年12月  査読有り
  • Guoqin Wang, Masafumi Watanabe, Yasushi Imai, Kazuo Hara, Ichiro Manabe, Koji Maemura, Momoko Horikoshi, Atsuko Ozeki, Chikako Itoh, Takao Sugiyama, Takashi Kadowaki, Tsutomu Yamazaki, Ryozo Nagai
    Journal of human genetics 57(11) 727-33 2012年11月26日  査読有り
    Modulator recognition factor-2 (Mrf2/AT-rich interaction domain (Arid)5b) has been revealed to be involved in pathogenesis of atherosclerosis and adipogenesis. Single-nucleotide polymorphisms (SNPs) in the MRF2/ARID5B gene are associated with coronary artery disease (CAD) and has been proposed as a candidate gene for type 2 diabetes (T2D). The study was aimed to determine whether any of the four MRF2/ARID5B SNPs (rs2893880, rs10740055, rs7087507 and rs10761600) associated with susceptibility to CAD are also associated with T2D, and to determine whether SNP genotype influences the levels of adiponectin and other clinical factors. Association of MRF2/ARID5B SNPs was investigated in 500 diabetic patients from the Department of Metabolic Diseases at the University of Tokyo and 243 hospital-based nondiabetic individuals from the Institute for Adult Disease Asahi Life Foundation Hospital and 500 community-based nondiabetic individuals from the Hiroshima Atomic Bomb Casualty Council Health Management Center. Associations of haplotypes of these SNP with levels of adiponectin and other clinical factors were evaluated when the data was available. We found rs2893880C, rs10740055A, rs7087507A and rs10761600T were increasingly associated with T2D in terms of allele/genotype frequencies of each SNP and their haplotype combinations. Individuals with haplotype CAAT indicated an 1.86 times higher prevalence of diabetes compared with individuals with GCGA (OR 1.86 (95% confidence interval (CI) 1.43-2.41)). Furthermore, CAAT significantly associated with adiponectin levels and other clinical factors. In conclusion, polymorphisms on the MRF2/ARID5B gene were associated with susceptibility to T2D as well as adiponectin and other clinical factors, which was in a completely concordant way with their associations with CAD.
  • Minami Yoshiyasu, Sahara Makoto, Nakajima Toshiaki, Ikutomi Masayasu, Morita Toshihiro, Yamashita Hiroshi, Hirata Yasunobu, Nagai Ryozo, Sata Masataka
    CIRCULATION 126(21) 2012年11月20日  査読有り

MISC

 1912

書籍等出版物

 21

共同研究・競争的資金等の研究課題

 91