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
  • Tadashi Yamazaki, Jun-ichi Suzuki, Ryoichi Shimamoto, Taeko Tsuji, Yuki Ohmoto-Sekine, Toshihiro Morita, Hiroshi Yamashita, Junko Honye, Ryozo Nagai, Shuhei Komatsu, Masaaki Akahane, Kuni Ohtomo
    Radiography 14(2) 98-104 2008年5月  査読有り
    Purpose: Hounsfield CT values across coronary CT angiograms constitute CT value-spatial profile curves. These CT profile curves are independent of window settings, and therefore, parameters derived from the curves can be used for objective anatomic analyses. Applicability of parameters derived from the curves to quantification of coronary in-stent patency has not yet been evaluated. Methods: Twenty-five CT value-spatial profile curves were delineated from 10 consecutive coronary stents to test correlation between the curve derived parameter (i.e., the minimum extreme value normalized by dividing by the maximum value of the curves obtained at neighboring outside of stents) and three intravascular ultrasound (IVUS) parameters. Results: Correlation coefficients between normalized minimum extreme value of CT value-spatial profile curves and three IVUS parameters (such as patent cross-sectional in-stent area, the percentage of patent cross-sectional in-stent area, and coronary artery intra-stent diameter) were 0.65 (p &lt 0.01), 0.44 (p &lt 0.05) and 0.51 (p &lt 0.05), respectively. Conclusions: CT parameters defined on Hounsfield CT value-spatial profile curves correlated significantly with IVUS parameters for quantitative coronary in-stent patency. A new approach with CT coronary angiography is therefore indicated for the noninvasive assessment of in-stent re-stenosis. © 2007 The College of Radiographers.
  • Hajime Fujimoto, Jun-Ichi Taguchi, Yasushi Imai, Seiji Ayabe, Hideki Hashimoto, Hisae Kobayashi, Ken Ogasawara, Tadanori Aizawa, Minoru Yamakado, Ryozo Nagai, Minoru Ohno
    European Heart Journal 29(10) 1267-1274 2008年5月  査読有り
    Aims: Oxidative damage promotes atherosclerosis. Manganese superoxide dismutase (MnSOD) is an antioxidant enzyme localized in mitochondria. We investigated the associations of the MnSOD polymorphism (valine-to-alanine in the mitochondrial-targeting domain) with its activity in leukocytes, with macrophage apoptosis by oxidized low-density lipoprotein (oxLDL), and with coronary artery disease (CAD). Methods and results: Blood samples were taken from 50 healthy subjects. The mitochondrial MnSOD activities in leukocytes were 542.4 ± 71.6 U/mg protein (alanine/alanine, n = 2), 302.0 ± 94.9 U/mg protein (alanine/valine, n = 12), and 134.0 ± 67.1 U/mg protein (valine/valine, n = 36 P &lt 0.0001 for non-valine/valine vs. valine/valine). Macrophages were treated with oxLDL. After incubation, the percentages of apoptotic macrophages were 48.6 ± 3.6% (alanine/alanine), 78.6 ± 9.8% (alanine/valine), and 87.5 ± 7.0% (valine/valine) (P &lt 0.0001, non-valine/valine vs. valine/valine). The association of the MnSOD polymorphism with CAD was investigated using blood samples collected from 498 CAD patients and 627 healthy subjects the alanine allele was found to reduce the risk of CAD and acute myocardial infarction (AMI). Conclusion: Our data indicate that the alanine variant of signal peptide increases the mitochondrial MnSOD activity, protects macrophages against the oxLDL-induced apoptosis, and reduces the risk of CAD and AMI. © The Author 2007.
  • 江口 航生, 真鍋 一郎, 大石 由美子, 沈 華, 松本 佐保姫, 藤生 克仁, 武田 憲文, 大杉 満, 戸辺 一之, 門脇 孝, 永井 良三
    糖尿病 51(Suppl.1) S-318 2008年4月  査読有り
  • Miwa Matsumoto, Masataka Sata, Daiju Fukuda, Kimie Tanaka, Masaaki Soma, Yasunobu Hirata, Ryozo Nagai
    Atherosclerosis 197(2) 524-33 2008年4月  査読有り
    Accumulating evidence demonstrates that dietary intake of n-3 polyunsaturated fatty acids (PUFAs) is associated with reduced incidence of cardiovascular events. However, the molecular mechanisms by which n-3 PUFAs prevent atherosclerosis are not fully understood. Here, we examined the effect of eicosapentaenoic acid (EPA), a major n-3 PUFA, on the pathogenesis of atherosclerosis in ApoE-deficient mice. Five-week-old ApoE-deficient male mice were fed on western-type diet supplemented with 5% (w/w) EPA (EPA group, n=7) or not (control group, n=5) for 13 weeks. An analysis of the fatty acid composition of liver homogenates revealed a marked increase of the n-3 PUFA content in the EPA group (n-3/n-6 ratio: 0.20+/-0.01 vs. 2.5+/-0.2, p<0.01). En face Sudan IV staining of the aorta and oil red O-staining of the aortic sinus revealed that EPA significantly suppressed the development of atherosclerotic lesions. We also observed anti-atherosclerotic effects of EPA in LDL-receptor-deficient mice. The lesions of the EPA group contained more collagen (19.6+/-2.4% vs. 32.9+/-3.9%, p<0.05) and smooth muscle cells (1.3+/-0.2% vs. 3.6+/-0.8%, p<0.05) and less macrophages (32.7+/-4.1% vs. 14.7+/-2.0%, p<0.05). Pretreatment with EPA attenuated the up-regulation of VCAM-1, ICAM-1 and MCP-1 in HUVECs as well as the expression of MMP-2 and MMP-9 in macrophage-like cells induced by TNF-alpha. The anti-inflammatory effects of EPA were abrogated when the expression of peroxisome proliferator-activated receptor alpha (PPARalpha) was suppressed. EPA may potentially reduce and stabilize atherosclerotic lesions through its anti-inflammatory effects.
  • Takahide Kohro, Yuji Furui, Naohiro Mitsutake, Ryo Fujii, Hiroyuki Morita, Shinya Oku, Kazuhiko Ohe, Ryozo Nagai
    International Heart Journal 49(2) 193-203 2008年3月  査読有り
    Similar to the healthcare systems in other industrialized countries, the Japanese healthcare system is facing the problem of increasing medical expenditure. In Japan, this situation may be primarily attributed to advanced technological developments, an aging population, and increasing patient demand. Japan also faces the problem of a declining youth population due to a low birth rate. Taken together, these problems present the healthcare system with a very difficult financial situation. Several reforms have been undertaken to contain medical expenditure, such as increasing employee copayment for health insurance from 10% to 20% in 1997 and from 20% to 30% in 2003 in order to curb unnecessary visits to medical institutions. Since the aging of the Japanese population is inevitable, a suitable method to contain medical expenditure may be to screen individuals who are likely to develop lifestyle-related diseases and conduct early intervention programs for them to prevent the development of diseases such as myocardial infarction or stroke that are costly to treat. If this goal is attained, it may contribute to the containment of medical expenditure as well as to improving the quality of life of the elderly. Therefore, the Japanese Ministry of Health, Labor and Welfare has decided to introduce a nationwide health screening and intervention program specifically targeting the metabolic syndrome commencing April 2008. Here, we discuss (1) the background of the Japanese healthcare system and the problems facing it, (2) the underlying objective and details of the new screening program, and (3) the expected impact of the program.
  • Makoto Sonoda, Katsu Takenaka, Kansei Uno, Aya Ebihara, Ryozo Nagai
    ECHOCARDIOGRAPHY-A JOURNAL OF CARDIOVASCULAR ULTRASOUND AND ALLIED TECHNIQUES 25(3) 242-248 2008年3月  査読有り
    A bicuspid aortic valve (BAV) often causes aortic stenosis (AS) or regurgitation (AR). In 54 patients with a BAV (48 +/- 16 years), transthoracic and transesophageal echo were performed to measure aortic annulus diameter (AAD), to evaluate the severity of aortic valve disease (AVD) and to calculate the area eccentricity index (AEI) of a BAV defined as a ratio of the larger aortic cusp area to a smaller aortic cusp area. By multiple linear regression analysis, the severity of AR correlated significantly with the AAD (r = 0.38) and AEI (r = 0.35) (P &lt; 0.05) and that of AS correlated significantly with the AAD (r = -0.40) and AEI (r = 0.34) (P &lt; 0.05). Thirty-six patients showed anteroposteriorly (A-P) located BAVs and 18 patients showed right-left (R-L) located BAVs. The AAD was larger in A-P type than in R-L type (15 +/- 3 vs 13 +/- 2 mm/BSA, P &lt; 0.05) and there was no difference in the age and AEI between the two groups. AR was more severe in A-P type than in R-L type while AS was more severe in R-L type than in A-P type (P &lt; 0.05). Twenty-nine patients showed raphes. The AEI was larger in raphe (+) type than in raphe (-) type (1.83 +/- 0.53 vs 1.51 +/- 0.47, P &lt; 0.05) and there was no difference in the AAD and severity of AVD between the two groups. In conclusion, a BAV with larger aortic annulus or A-P located will tend to cause AR while a BAV with smaller aortic annulus or R-L located will tend to cause AS.
  • Nobukazu Ishizaka, Yuko Ishizaka, Ei-Ichi Toda, Hiroji Shimomura, Kazuhiko Koike, George Seki, Ryozo Nagai, Minoru Yamakado
    HYPERTENSION RESEARCH 31(3) 485-492 2008年3月  査読有り
    Cigarette smoking may affect urinary albumin excretion and the glomerular filtration rate in both diabetic and nondiabetic subjects. Here we investigated the association between smoking and decreased or elevated glomerular filtration rate (GFR) and albuminuria by analyzing data from 7,078 Japanese men who had undergone a general health screening between 2005 and 2006. GFR was estimated with the Modified Diet in Renal Disease (MDRD) equation, and low estimated GFR (eGFR) and elevated eGFR were defined, respectively, as eGFR &lt;60 and &gt;90.7 mL/min/1.73 m(2). Albuminuria was considered present when the urinary albumin excretion ratio (UAER), expressed as mg/g creatinine, was &gt;= 30 mg/g. Multivariate logistic regression analysis showed that current smoking was associated inversely with low eGFR, and positively with albuminuria and elevated eGFR. The association between current smoking and low or elevated GFR was dependent on the number of cigarettes smoked per day. Former smoking was also significantly inversely associated with low eGFR, but the association between former smoking and albuminuria or elevated eGFR was not significant, even in individuals who had stopped smoking less than 1 year before. These data suggest that cigarette smoking may increase the prevalence of albuminuria and elevated eGFR or hyperfiltration, traits that might be reversed by smoking cessation. Although this concept should be verified by future longitudinal studies, our data suggest that we may need to take into account an individual&apos;s smoking status when assessing the presence or absence of chronic kidney disease because cigarette smoking may transiently increase eGFR.
  • 藤生 克仁, 真鍋 一郎, 永井 良三
    Therapeutic Research 29(2) 178-178 2008年2月  
  • Yoshiko Munemasa, Toru Suzuki, Kenichi Aizawa, Saku Miyamoto, Yasushi Imai, Takayoshi Matsumura, Masami Horikoshi, Ryozo Nagai
    Molecular and cellular biology 28(3) 1171-81 2008年2月  査読有り
    Regulation of chromatin in eukaryotic transcription requires histone-modifying enzymes, nucleosome remodeling complexes, and histone chaperones. Specific regulation of histone incorporation/eviction by histone chaperones on the promoter (e.g., region specific) is still poorly understood. In the present study, we show that direct and functional interaction of histone chaperone and DNA-binding transcription factor leads to promoter region-specific histone incorporation and inhibition of histone acetylation. We report here that the DNA-binding transcription factor Krüppel-like factor 5 (KLF5) interacts with the novel histone chaperone acidic nuclear phosphoprotein 32B (ANP32B), leading to transcriptional repression of a KLF5-downstream gene. We further show that recruitment of ANP32B onto the promoter region requires KLF5 and results in promoter region-specific histone incorporation and inhibition of histone acetylation by ANP32B. Extracellular stimulus (e.g., phorbol ester) regulates this mechanism in the cell. Collectively, we have identified a novel histone chaperone, ANP32B, and through analysis of the actions of this factor show a new mechanism of promoter region-specific transcriptional regulation at the chromatin level as mediated by the functional interaction between histone chaperone and DNA-binding transcription factor.
  • Yasutomi Higashikuni, Nobukazu Ishizaka, Yuko Ishizaka, Ei-ichi Toda, Ryozo Nagai, Minoru Yamakado
    HYPERTENSION RESEARCH 31(2) 213-219 2008年2月  査読有り
    In hypertensive subjects, it has been demonstrated that the lower the blood pressure, the lower the incidence of chronic kidney disease (CKD). However, whether this relationship holds true in individuals without hypertension-that is, in individuals with a blood pressure &lt;140/90 mmHg-remains unknown. This study was performed to assess the relationship between blood pressure and CKD in a Japanese population without hypertension. Among 13,007 Japanese participants in a general health screening, 9,596 (5,691 men and 3,905 women) were found to have either normal blood pressure or prehypertension, and were enrolled in this study. We categorized these individuals' blood pressure into six classes: BP-Cl, &lt;90/&lt;65 mmHg; BPC2, 90-100/65-70 mmHg; BP-C3, 100-110/70-75 mmHg; BP-C4, 110-120/75-80 mmHg; BP-C5, 120-130/80-85 mmHg; and BP-C6, 130-140/85-90 mmHg. Albuminuria was defined as a urinary albumin excretion ratio of &gt;= 30 mg/g. Low estimated glomerular filtration rate (eGFR) was defined as eGFR &lt;60 mL/min/1.73 m(2). In men, when BP-C3 was used as a reference, multivariate logistic regression analysis adjusted for age, body mass index, serum lipid profiles, fasting plasma glucose and smoking status showed that BP-Cl, BP-C2, BP-C4, BP-C5 and BP-C6 were associated with albuminuria with an adjusted odds ratio of 1.85 (0.53-6.46), 1.22 (0.59-2.51), 1.62 (1.01-2.59), 2.57 (1.64-4.02), and 3.81 (2.44-5.96). In women, the adjusted odds ratios of the risk for albuminuria in BP-C2, BP-C3, BP-C4, BP-C5 and BP-C6, as compared with BP-C1 as a reference, were 1.83 (0.70-4.79), 2.13 (0.84-5.42), 2.80 (1.10-7.14), 2.59 (0.99-6.78), and 3.99 (1.50-10.64). Blood pressure was not significantly associated with low eGFR in either gender. The risk for albuminuria was significantly greater when blood pressure exceeded 110/75 mmHg in both genders.
  • Satoshi Nishimura, Ichiro Manabe, Mika Nagasaki, Kinya Seo, Hiroshi Yamashita, Yumiko Hosoya, Mitsuru Ohsugi, Kazuyuki Tobe, Takashi Kadowaki, Ryozo Nagai, Seiryo Sugiura
    The Journal of clinical investigation 118(2) 710-21 2008年2月  査読有り
    To assess physiological and pathophysiological events that involve dynamic interplay between multiple cell types, real-time, in vivo analysis is necessary. We developed a technique based on confocal laser microscopy that enabled us to analyze and compare the 3-dimensional structures, cellular dynamics, and vascular function within mouse lean and obese adipose tissue in vivo with high spatiotemporal resolution. We found increased leukocyte-EC-platelet interaction in the microcirculation of obese visceral adipose tissue in ob/ob and high-fat diet-induced obese mice. These changes were indicative of activation of the leukocyte adhesion cascade, a hallmark of inflammation. Local platelet activation in obese adipose tissue was indicated by increased P-selectin expression and formation of monocyte-platelet conjugates. We observed upregulated expression of adhesion molecules on macrophages and ECs in obese visceral adipose tissue, suggesting that interactions between these cells contribute to local activation of inflammatory processes. Furthermore, administration of anti-ICAM-1 antibody normalized the cell dynamics seen in obese visceral fat. This imaging technique to analyze the complex cellular interplay within obese adipose tissue allowed us to show that visceral adipose tissue obesity is an inflammatory disease. In addition, this technique may prove to be a valuable tool to evaluate potential therapeutic interventions.
  • Kimie Tanaka, Masataka Sata, Takeshi Natori, Joo-Ri Kim-Kaneyama, Kiyoshi Nose, Motoko Shibanuma, Yasunobu Hirata, Ryozo Nagai
    FASEB journal : official publication of the Federation of American Societies for Experimental Biology 22(2) 428-36 2008年2月  査読有り
    Recent evidence suggests that bone marrow-derived cells may contribute to repair and lesion formation following vascular injury. In most studies, bone marrow-derived cells were tracked by transplanting exogenous cells into bone marrow that had been compromised by irradiation. It remains to be determined whether endogenous circulating progenitors actually contribute to arterial remodeling under physiological conditions. Here, we established a parabiotic model in which two mice were conjoined subcutaneously without any vascular anastomosis. When wild-type mice were joined with transgenic mice that expressed green fluorescent protein (GFP) in all tissues, GFP-positive cells were detected not only in the peripheral blood but also in the bone marrow of the wild-type mice. The femoral arteries of the wild-type mice were mechanically injured by insertion of a large wire. At 4 wk, there was neointima hyperplasia that mainly consisted of alpha-smooth muscle actin-positive cells. GFP-positive cells were readily detected in the neointima (14.8+/-4.5%) and media (31.1+/-8.8%) of the injured artery. Some GFP-positive cells expressed alpha-smooth muscle actin or an endothelial cell marker. These results indicate that circulating progenitors contribute to re-endothelialization and neointimal formation after mechanical vascular injury even in nonirradiated mice.
  • Yo Tanaka, Kae Sato, Tatsuya Shimizu, Masayuki Yamato, Teruo Okano, Ichiro Manabe, Ryozo Nagai, Takehiko Kitamori
    12th International Conference on Miniaturized Systems for Chemistry and Life Sciences - The Proceedings of MicroTAS 2008 Conference 1666-1668 2008年  
    In this paper, we have driven polydimethylsiloxane (PDMS) micropillars by us-ing vascular smooth muscle cells (SMCs) on them. SMCs could both drive and re-turn micropillars by only chemical stimuli. From this result, the principle of an SMC-based bio-microactuator was demonstrated.
  • 益澤 明広, 大野 貴之, 木下 修, 小野 稔, 本村 昇, 高本 眞一, 藤田 英雄, 安東 治郎, 森田 敏宏, 永井 良三
    日本心臓血管外科学会雑誌 37(Suppl.) 361-361 2008年1月  
  • Makoto Sonoda, Katsu Takenaka, Kansei Uno, Aya Ebihara, Ryozo Nagai
    Journal of Echocardiography 6(1) 1-8 2008年  査読有り
    Background: Severe mitral regurgitation (MR) is one of the most important complications of mitral. valve prolapse (MVP) and it often requires surgical treatment. This study is aimed to assess the relation of mitral valve morphology to severe MR complicated with, MVP. Methods: Transesophageal echocardiography was performed in 37 patients with MVP and 30 control subjects. Results: The anterior mitral leaflet (AML) and posterior mitral leaflet (PML) were thicker and longer, and the mitral annulus was larger in patients with MVP than in control subjects (p&lt 0.05). The degree of MVP correlated significantly with the leaflet thickness in systole (AML r=0.70, PML: r=0.65, p&lt 0.05). In patients with MVP without ruptured chordae tendineae (RCT), the severity of MR correlated significantly with the leaflet thickness, leaflet length and annular diameter (p&lt 0.05). The prolapsed PMLs with RCT were thicker and longer than those without RCT (p&lt 0.05). Conclusions: The leaflet thickness, leaflet length and annular diameter are "proportionally" redundant in patients with MVP, and the redundancy is closely related to the occurrence of RCT or severe MR. © 2008 Japanese Society of Echocardiography.
  • Makoto Sonoda, Teruhiko Aoyagi, Katsu Takenaka, Kansei Uno, Ryozo Nagai
    International Heart Journal 49(1) 95-103 2008年1月  査読有り
    Angiotensin receptor blockers (ARB) have been emerging as drugs to treat atherosclerosis. The effectiveness of the ARB losartan at reducing atherosclerosis was compared with that of ACE inhibitors in hypertensive patients. A total of 50 patients with hypertension were divided into 3 groups: a control group receiving neither an ARB nor an ACE inhibitor (n = 14), a losartan group (n = 22) receiving 50 mg/day of losartan, and an ACE, inhibitor group (n = 14) receiving either 5 mg/day of enalapril or 5 mg/ day of imidapril. Atherosclerosis was evaluated based on the intima-media thickness (IMt) of the common carotid artery measured by B-mode ultrasound at baseline and after approximately 12 months of treatment. After the treatment IMT significantly decreased with losartan (from 0.87 ± 0.14 to 0.79 ± 0.16 mm, P &lt 0.05) and with ACE inhibitor (from 0.81 ± 0.14 to 0.74 ± 0.11 mm, P &lt 0.05). The reduction was comparable between the two groups, -0.078 ± 0.136 with losartan and -0.073 ± 0.109 mm with ACE inhibitor, and the rate of the reduction was similar between the two drugs -0.098 ± 0.142 mm/year with losartan and (-0.076 ± 0.118 mm/year) with ACE inhibitor. On the contrary, IMT did not change in the control group (from 0.90 ± 0.20 to 0.95 ± 0.26 mm) during the treatment period. Concomitant medication and coronary risk factors such as hyperlipidemia, diabetes mellitus, and smoking did not differ significantly among the groups. The antiatherosclerotic- effect of losartan on the carotid artery was comparable to that of ACE-inhibitors, and less adverse effects, such as coughing that occurs with ACE inhibitors, were observed. Losartan appears to be a better alternative to ACE inhibitors for treating atherosclerosis in Japanese hypertensive patients.
  • Yo Tanaka, Kae Sato, Tatsuya Shimizu, Masayuki Yamato, Teruo Okano, Ichiro Manabe, Ryozo Nagai, Takehiko Kitamori
    Lab on a chip 8(1) 58-61 2008年1月  査読有り
    We have demonstrated the working principle of a bio-microactuator using smooth muscle cells (SMCs) by driving micropillars coupled to cultured SMCs and controlled pillar displacements by chemical stimuli; the generated driving force was estimated to be over 1.1 microN.
  • Nobukazu Ishizaka, Yuko Ishizaka, Ei-Ichi Toda, Kazuhiko Koike, Minoru Yamakado, Ryozo Nagai
    ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY 28(1) 160-165 2008年1月  査読有り
    Objective-Carcinoembryonic antigen (CEA), a serological marker of malignant tumors, may show a modest increase under some nonmalignant conditions, such as ageing and cigarette smoking. We have investigated whether serum CEA levels are associated with early carotid atherosclerosis. Methods and Results-Cross-sectional data from 4181 male individuals who underwent general health screening were analyzed. The interquartile of cutoff values of serum CEA levels were 1.0, 1.6, and 2.5 ng/mL. Cigarette smoking was associated with increased serum CEA levels in a dose- and duration-dependent manner, and this association was more prominent in current than former smokers. Logistic regression analysis adjusted for age, body mass index, serum lipid and glucose profiles, white blood cell count, C-reactive protein, and smoking habits showed that the first, second, third, and fourth CEA quartiles were associated with carotid plaque with an odds ratio of 1 (reference), 1.25 (95% CI 1.03 to 1.52, P=0.023), 1.49 (95% CI 1.23 to 1.82 P&lt;0.001), and 1.34 (95% CI 1.08 to 1.65, P=0.007), respectively. Although serum CEA levels were associated with metabolic syndrome, association between serum CEA and carotid plaque was significant in individuals without metabolic syndrome. Conclusions-Serum CEA was associated with carotid atherosclerosis independently of atherogenic risk factors and markers of inflammation. Our data suggest that a slight elevation of CEA in current smokers, as well as in never smokers, may not be an innocuous observation from the viewpoint of atherosclerosis.
  • Yuka Ichikawa-Shindo, Takayuki Sakurai, Akiko Kamiyoshi, Hisaka Kawate, Nobuyoshi Iinuma, Takahiro Yoshizawa, Teruhide Koyama, Junichi Fukuchi, Satoshi Iimuro, Nobuo Moriyama, Hayato Kawakami, Toshinori Murata, Kenji Kangawa, Ryozo Nagai, Takayuki Shindo
    The Journal of clinical investigation 118(1) 29-39 2008年1月  査読有り
    Adrenomedullin (AM) is a peptide involved both in the pathogenesis of cardiovascular diseases and in circulatory homeostasis. The high-affinity AM receptor is composed of receptor activity-modifying protein 2 or 3 (RAMP2 or -3) and the GPCR calcitonin receptor-like receptor. Testing our hypothesis that RAMP2 is a key determinant of the effects of AM on the vasculature, we generated and analyzed mice lacking RAMP2. Similar to AM-/- embryos, RAMP2-/- embryos died in utero at midgestation due to vascular fragility that led to severe edema and hemorrhage. Vascular ECs in RAMP2-/- embryos were severely deformed and detached from the basement membrane. In addition, the abnormally thin arterial walls of these mice had a severe disruption of their typically multilayer structure. Expression of tight junction, adherence junction, and basement membrane molecules by ECs was diminished in RAMP2-/- embryos, leading to paracellular leakage and likely contributing to the severe edema observed. In adult RAMP2+/- mice, reduced RAMP2 expression led to vascular hyperpermeability and impaired neovascularization. Conversely, ECs overexpressing RAMP2 had enhanced capillary formation, firmer tight junctions, and reduced vascular permeability. Our findings in human cells and in mice demonstrate that RAMP2 is a key determinant of the effects of AM on the vasculature and is essential for angiogenesis and vascular integrity.
  • Daiju Fukuda, Masataka Sata, Nobukazu Ishizaka, Ryozo Nagai
    ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY 28(1) 90-96 2008年1月  査読有り
    Objective-It is suggested that the angiotensin II (Ang II)-Ang II type 1 receptor (AT1R) pathway plays a pivotal role in the pathogenesis of atherosclerosis. Recently, bone marrow (BM) cells were reported to express AT1R. Here, we investigated the role of AT1R in BM in the pathogenesis of atherosclerosis. Methods and Results-Genetic ablation or pharmacological blockade of AT1R led to a significant reduction and stabilization of atherosclerotic lesions in ApoE(-/-) mice. To elucidate the role of AT1R in BM, we generated several BM chimeric mice. Ang II promoted atherosclerosis progression in the BM chimeric mice that had AT1aR in BM, regardless of the absence of AT1aR in the recipient vasculature (P&lt;0.05). BM chimeric mice whose BM AT1aR was disrupted showed significantly less atherosclerotic lesions in aorta (P&lt;0.05) and more stable plaque with reduced accumulation of BM-derived cells compared with BM chimeric mice that had AT1aR-positive BM. Most of the BM-derived cells in atheroma were positive for a macrophage marker and expressed matrix metalloproteinase (MMP)-9 and monocyte chemoattractant protein-1. Conclusions-Our findings suggest that AT1R in BM plays an important role in the pathogenesis of atherosclerosis.
  • Po-Hsun Huang, Masataka Sata, Hiroaki Nishimatsu, Makoto Sumi, Yasunobu Hirata, Ryozo Nagai
    Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie 62(1) 46-52 2008年1月  査読有り
    Angiogenesis, the formation of new blood vessels, is a physiological response to tissue ischemia. Clinical evidence suggests that diabetic patients have endothelial dysfunction and impaired angiogenesis in response to ischemia. Here, we investigated the impact of diabetes on ischemia-induced collateral growth, and tested the hypothesis that peroxisome proliferator-activated receptor-gamma (PPARgamma) agonist augments collateral flow to ischemic tissue. We conducted unilateral hindlimb ischemia surgery in KKAy mice. Blood flow recovery was markedly impaired in diabetic mice compared with that in wild-type mice as determined by laser Doppler imaging. Treatment of KKAy mice with pioglitazone partially restored the blood flow recovery. Anti-CD31 immunostaining revealed that pioglitazone also significantly improved the capillary density in ischemic limb muscle. Endothelial NO synthase (eNOS) activity was ameliorated in diabetic mice treated with pioglitazone as determined by vasorelaxation in response to acetylcholine. Pioglitazone normalized vascular endothelial growth factor (VEGF) protein levels, which was decreased in ischemic muscle of KKAy mice, and up-regulated eNOS phosphorylation at Ser-1177 and Akt phosphorylation at Ser-473 in ischemic muscle. Pioglitazone had no beneficial effects on blood flow recovery in diabetic mice treated with N(G)-nitro-l-arginine methyl ester (L-NAME). Our findings demonstrate that pioglitazone significantly ameliorates endothelial dysfunction and enhances blood flow recovery after tissue ischemia in diabetic mice. Activation of eNOS appears to be essential for pioglitazone to promote angiogenesis in ischemic tissue.
  • 北村 聖, 永井 良三
    日本内科学会雑誌 96(12) 2744-2750 2007年12月10日  
    医学教育は社会のさまざまな面と接点があり,多様な価値観が含まれる.最新の医学知識を身につけるだけでなく,職業専門人としての教育も求められる.とくに学生時代に学ぶ知識や技能と,現場で求められる知識·技能の解離の大きいことが,多くの混乱を招いている.しかし知識不足だけが,混乱の原因ではない.医療のあり方や,医学研究の進む方向が十分に議論されてこなかったことも一因と思われる.医療安全の問題は,近代化をめざす医療システムの根本に関わる問題であり,医学教育,なかんずく生涯教育の恰好の課題である.また,近年の臨床研究の停滞は,これまでの実験医学のあり方を基本から見直す機会を与えた.医療者の生涯教育で取り組むべき重要な課題であることが明らかになったと言える.本稿では,我が国の生涯教育の現状と課題,さらに今変わりつつある医療と医学の考え方について紹介した.<br>
  • Kan Saito, Takafumi Ito, Nobuko Asashima, Minoru Ohno, Ryozo Nagai, Hiromi Fujita, Nobuo Koizumi, Ai Takano, Haruo Watanabe, Hiroki Kawabata
    American Journal of Tropical Medicine and Hygiene 77(6) 1124-1127 2007年12月  査読有り
    A 78-year-old Japanese man who had clinical symptoms and a flu-like illness with fever, chills, diarrhea, and arthralgia had traveled to Cambodia and Khabarovsk, Russia, before the onset of symptoms and illness. He had been bitten by an Ixodes persulcatus tick in which the DNA of Borrelia valaisiana was detected. The patient's symptoms improved rapidly after treatment with minocycline. Serologic examination detected antibodies to Lyme disease Borrelia. An flabB polymerase chain reaction with the patient's plasma amplified a DNA fragment similar to that of B. valaisiana. Copyright © 2007 by The American Society of Tropical Medicine and Hygiene.
  • M Horikoshi, K Hara, C Ito, N Shojima, R Nagai, K Ueki, P Froguel, T Kadowaki
    Diabetologia 50(12) 2461-6 2007年12月  査読有り
    AIMS/HYPOTHESIS: Recently, several groups have carried out whole-genome association studies in European and European-origin populations and found novel type 2 diabetes-susceptibility genes, fat mass and obesity associated (FTO), solute carrier family 30 (zinc transporter), member 8 (SLC30A8), haematopoietically expressed homeobox (HHEX), exostoses (multiple) 2 (EXT2), CDK5 regulatory subunit associated protein 1-like 1 (CDKAL1), cyclin-dependent kinase inhibitor 2B (p15, inhibits CDK4) (CDKN2B) and insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2), which had not been in the list of functional candidates. The aim of this study was to determine the association between single nucleotide polymorphisms (SNPs) in these genes and type 2 diabetes in participants from the Japanese population. METHODS: Sixteen previously reported SNPs were genotyped in 864 Japanese type 2 diabetes individuals (535 men and 329 women; age 63.1 +/- 9.5 years (mean+/-SD), BMI 24.3 +/- 3.9 kg/m(2)) and 864 Japanese control individuals (386 men and 478 women; age 69.5 +/- 6.8 years, BMI 23.8 +/- 3.7 kg/m(2)). RESULTS: The SNPs rs5015480 [odds ratio (OR) = 1.46 (95% CI 1.20-1.77), p = 2.0 x 10(-4)], rs7923837 [OR = 1.40 (95% CI 1.17-1.68), p = 2.0 x 10(-4)] and rs1111875 [OR = 1.30 (95% CI 1.11-1.52), p = 0.0013] in HHEX were significantly associated with type 2 diabetes with the same direction as previously reported. SNP rs8050136 in FTO was nominally associated with type 2 diabetes [OR = 1.22 (95% CI 1.03-1.46), p = 0.025]. SNPs in other genes such as rs7756992 in CDKAL1, rs10811661 in CDKN2B and rs13266634 in SLC30A8 showed nominal association with type 2 diabetes. rs7756992 in CDKAL1 and rs10811661 in CDKN2B were correlated with impaired pancreatic beta cell function as estimated by the homeostasis model assessment beta index (p = 0.023, p = 0.0083, respectively). CONCLUSIONS/INTERPRETATION: HHEX is a common type 2 diabetes-susceptibility gene across different ethnic groups.
  • Yoshinori Takeuchi, Naoya Yahagi, Yoshimi Nakagawa, Takashi Matsuzaka, Ritsuko Shimizu, Motohiro Sekiya, Yoko Iizuka, Ken Ohashi, Takanari Gotoda, Masayuki Yamamoto, Ryozo Nagai, Takashi Kadowaki, Nobuhiro Yamada, Jun-Ichi Osuga, Hitoshi Shimano
    Biochemical and biophysical research communications 363(2) 329-35 2007年11月16日  査読有り
    Sterol regulatory element-binding protein (SREBP)-1c is the master regulator of lipogenic gene expression in liver. The mRNA abundance of SREBP-1c is markedly induced when animals are refed after starvation, although the regulatory mechanism is so far unknown. To investigate the mechanism of refeeding response of SREBP-1c gene expression in vivo, we generated a transgenic mouse model that carries 2.2kb promoter region fused to the luciferase reporter gene. These transgenic mice exhibited refeeding responses of the reporter in liver and adipose tissues with extents essentially identical to those of endogenous SREBP-1c mRNA. The same results were obtained from experiments using adenovirus-mediated SREBP-1c-promoter-luciferase fusion gene transduction to liver. These data demonstrate that the regulation of SREBP-1c gene expression is at the transcription level, and that the 2.2kb 5'-flanking region is sufficient for this regulation. Moreover, when these transgenic or adenovirus-infected mice were placed on insulin-depleted state by streptozotocin treatment, the reporter expression was upregulated as strongly as in control mice, demonstrating that this regulation is not dominated by serum insulin level. These mice are the first models to provide the mechanistic insight into the transcriptional regulation of SREBP-1c gene in vivo.
  • Taeko Tsuji, Jun-Ichi Suzuki, Ryoichi Shimamoto, Tadashi Yamazaki, Yuki Ohomoto, Kuniaki Iwasawa, Ryozo Nagai
    International Heart Journal 48(5) 615-621 2007年11月13日  査読有り
    The need for long-term follow-up in Kawasaki disease is poorly recognized although cardiac sudden death attacks asymptomatic young people with past illness after a long latent period. Therefore, in order to prevent cardiac disasters, high risk groups should be identified and the prevalence rate of the disease should be determined for crisis management. A total of 9,965 consecutive freshmen at the University of Tokyo were the subject of a questionnaire. Their parents/guardians who were briefed on the diagnostic criteria of the acute phase of Kawasaki disease actually completed the questionnaire. Students with a positive diagnosis underwent rest and exercise-stress electrocardiography and routine echocardiography. The overall prevalence rate was 0.57%. The rate in males (0.63%) was greater than that in females (0.32%) (P &lt 0.05). Electrocardiography and routine echocardiography identified no indices specific to a past illness of Kawasaki disease. The prevalence rate indicated that about 6 in 1000 students were high risk students who needed special care while at university. Since there are few symptoms and no signs indicating a past illness of Kawasaki disease, intensive history-taking from parents/guardians who are familiar with their acute symptoms during childhood is required in order to identify those at high risk of a coronary event.
  • Norihiko Takeda, Koji Maemura, Shuichi Horie, Katsutaka Oishi, Yasushi Imai, Tomohiro Harada, Tetsuya Saito, Taro Shiga, Eisuke Amiya, Ichiro Manabe, Norio Ishida, Ryozo Nagai
    The Journal of biological chemistry 282(45) 32561-7 2007年11月9日  査読有り
    Cardiovascular diseases are closely related to circadian rhythm, which is under the control of an internal biological clock mechanism. Although a biological clock exists not only in the hypothalamus but also in each peripheral tissue, the biological relevance of the peripheral clock remains to be elucidated. In this study we searched for clock-controlled genes in vascular endothelial cells using microarray technology. The expression of a total of 229 genes was up-regulated by CLOCK/BMAL2. Among the genes that we identified, we examined the thrombomodulin (TM) gene further, because TM is an integral membrane glycoprotein that is expressed primarily in vascular endothelial cells and plays a major role in the regulation of intravascular coagulation. TM mRNA and protein expression showed a clear circadian oscillation in the mouse lung and heart. Reporter analyses, gel shift assays, and chromatin immunoprecipitation analyses using the TM promoter revealed that a heterodimer of CLOCK and BMAL2 binds directly to the E-box of the TM promoter, resulting in TM promoter transactivation. Indeed, the oscillation of TM gene expression was abolished in clock mutant mice, suggesting that TM expression is regulated by the clock gene in vivo. Finally, the phase of circadian oscillation of TM mRNA expression was altered by temporal feeding restriction, suggesting TM gene expression is regulated by the peripheral clock system. In conclusion, these data suggest that the peripheral clock in vascular endothelial cells regulates TM gene expression and that the oscillation of TM expression may contribute to the circadian variation of cardiovascular events.
  • Nobukazu Ishizaka, Yuko Ishizaka, Ei-ichi Toda, Kazuhiko Koike, George Seki, Ryozo Nagai, Minoru Yamakado
    HYPERTENSION RESEARCH 30(11) 1059-1064 2007年11月  査読有り
    Obesity is a known risk factor for hypertension and diabetes, both of which ultimately promote renal dysfunction. In the current study, we investigated the association between body mass index (BMI) and chronic kidney disease (CKD) in 8,168 Japanese individuals (2,924 women, 5,244 men) who underwent general health screening. CKD was diagnosed if the estimated glomerular filtration rate (eGFR) was less than 60 mL/ min/1.73 m(2) (designated as low eGFR) and/or if the urinary albumin/creatinine value was equal to or greater than 30 mg/g (designated as albuminuria). Logistic regression analysis adjusted for age, systolic blood pressure, fasting glucose, and smoking habits showed that, in men, both overweight (BMI 25-29 kg/m(2)) and obesity (BMI &gt;= 30 kg/m(2)) were associated with increased prevalence of low eGFR and albuminuria, whereas, in women, obesity was associated with albuminuria, but neither overweight nor obesity was associated with low eGFR. After multivariate adjustment, logistic regression analysis showed that BMI had a graded association with both low eGFR and albuminuria in men. On the other hand, in women, the second and third BMI quartiles were associated with a lower prevalence of albuminuria in comparison with the first BMI quartile. Essentially the same results were obtained when the subjects were subdivided according to the presence and absence of hypertension. Our data showed that overweight and obesity were associated with increased risk for CKD in Japanese individuals undergoing a general health screening, irrespective of the presence or absence of hypertension, although there was a gender difference in these associations.
  • Takayuki Ohno, Shinichi Takamoto, Noboru Motomura, Minoru Ono, Jiro Ando, Toshihiro Morita, Hideo Fujita, Yasunobu Hirata, Ryozo Nagai, Takashi Shigeeda, Akira Hirose
    The Annals of thoracic surgery 84(5) 1474-8 2007年11月  査読有り
    BACKGROUND: We compared the 1-year outcome of coronary revascularization with sirolimus-eluting stents (SESs) or coronary artery bypass grafting (CABG) for coronary artery disease involving the left anterior descending artery (LAD) in diabetic patients according to their retinal status: no diabetic retinopathy (NDR) and diabetic retinopathy (DR). METHODS: Between April 2004 and October 2005, 220 consecutive patients with coronary artery disease involving the LAD underwent implantation of SESs; of these, 25 patients had NDR and 54 had DR. For each group, we included a comparison group of diabetic patients who had undergone CABG and had the same retinal status. RESULTS: During 1 year after revascularization, five cardiac events (cardiac death, myocardial infarction, and repeat revascularization) were noted in NDR-SES patients, four in NDR-CABG, 24 in DR-SES, and eight in DR-CABG patients. Most cardiac events were repeat revascularizations. Kaplan-Meier estimates of the incidence of cardiac events at 1 year were 21.1%, 11.4%, 44.0%, and 14.0%, respectively. Kaplan-Meier curves for cardiac events in SES patients were different from those of CABG patients for the DR group (p = 0.003), but not NDR groups. After adjustments for the potential confounders, the hazard ratio of cardiac events in DR-SES patients was 2.8 (95% confidence interval, 1.1 to 6.9; p = 0.02). CONCLUSIONS: Compared with SES implantation, CABG is more suitable for revascularization in patients with coronary artery disease involving the LAD and DR.
  • Tadashi Yamazaki, Jun-ichi Suzuki, Ryoichi Shimamoto, Taeko Tsuji, Yuki Ohmoto-Sekine, Kuni Ohtomo, Ryozo Nagai
    INTERNATIONAL HEART JOURNAL 48(6) 715-724 2007年11月  査読有り
    A randomized and prospective study was designed to prove the efficacy-of angiotensin II receptor blockers (ARB) in the amelioration of myocardial impairment in hypertrophic nonobstructive cardiomyopathy (HNCM). Nineteen consecutive patients with HNCM were randomly assigned to two groups and then underwent cine magnetic resonance evaluation of left ventricular mass (LVM) twice just before and after one year of observation. In the ARB group, 50 mg of losartan potassium was administered once daily during the observation period. The ratio of LVM after the observation period over that before the period was blindly compared between the two groups to estimate morphologically the ameliorative effect of ARB. In the ARB group, LVM was 203 47 cm(3) before the treatment period and 190 +/- 55 cm(3) after the period and the ratio of the final LVM over the initial LVM was 0.93 +/- 0.10. In the non-ARB group the initial and final LVM values were 177 48 cm(3) and 179 45 cm(3), and the ratio of the final LVM over the initial LVM was 1.02 +/- 0.07. The ratio of the final LVM over the initial LVM in the ARB group was significantly smaller (P = 0.03) than that in the non-ARB group. The smaller ratio in the ARB group strongly indicates that ARB ameliorated the natural course of HNCM during the one year observation period. Thus, this is the first demonstration of the therapeutic efficacy of ARB in human HNCM.
  • Nobukazu Ishizaka, Yuko Ishizaka, Ei-ichi Toda, Kazuhiko Koike, George Seki, Ryozo Nagai, Minoru Yamakado
    HYPERTENSION RESEARCH 30(11) 1035-1041 2007年11月  査読有り
    We investigated whether chronic kidney disease (CKD) was associated with carotid intima-media thickening in 1,351 male individuals undergoing general health screening. Glomerular filtration rate (GFR) was estimated by the Modification of Diet in Renal Disease equations using 0.881 as a coefficient for Japanese, and low estimated GFR (eGFR) was defined as an eGFR value of &lt; 60 mL/min/1.73 m(2). Albuminuria was defined as a urine albumin-to-urine creatinine ratio of &gt;= 30 mg/g, and CKD was defined when low eGFR and/or albuminuria was present. After adjusting for age, CKD was associated with carotid intima-media thickening with an odds ratio of 1.47 (95% confidence interval [CI] 1.05-2.06, p=0.0024). After adjusting for age, fasting plasma glucose, and smoking status, both albuminuria and low eGFR were significantly associated with intima-media thickening in individuals with hypertension with an odds ratio of 1.85 (95% CI 1.13-3.03, p=0.015) and 1.79 (95% CI 1.09-2.94, p=0.022), respectively. On the other hand, neither of them was associated with carotid intima-media thickening in individuals without hypertension. Similarly, after adjusting for age, systolic blood pressure, and smoking status, both albuminuria and low eGFR were significantly associated with intima-media thickening in individuals with high fasting glucose (defined as fasting plasma glucose levels of &gt;= 110 mg/dL or current use of anti-diabetic medication), but not in those without. Our data indicate that CKD or its components (low eGFR and albuminuria) may be associated with early carotid atherosclerosis in low-risk individuals, such as those undergoing general health screening, who have hypertension and/or impaired glucose metabolism.
  • Takaaki Yamada, Takahisa Kondo, Yasushi Numaguchi, Michitaka Tsuzuki, Tatsuaki Matsubara, Ichiro Manabe, Masataka Sata, Ryozo Nagai, Toyoaki Murohara
    Arteriosclerosis, thrombosis, and vascular biology 27(11) 2363-9 2007年11月  査読有り
    OBJECTIVES: Angiotensin II (ATII) type 1 receptor (AT1R) blocker (ARB) has been shown to inhibit neointimal formation. Bone marrow-derived mononuclear cells (BM-MNCs) give rise to smooth muscle (SM)-like cells at injured arterial wall and contribute to neointimal formation. However, role of the renin-angiotensin system in the homing process of SM-like cells during neointimal formation is unknown. MATERIAL AND METHODS: When human BM-MNCs and peripheral blood MNCs (PB-MNCs) were cultured under treatment with PDGF-BB and bFGF, these cells gave rise to SM-like cells with expression of alphaSMA, SMemb, and SM1 proteins. RT-PCR showed the expression of AT1R, ATII type 2 receptor (AT2R), alphaSMA, and SMemb mRNAs. ATII accelerated the differentiation of SM-like cells, which was inhibited by an ARB CV11974 (P<0.05). We then examined the effects of ATII, CV11974, and AT2R antagonist PD123319 on neointimal formation and BM-derived SM-like cell incorporation at injured arteries in vivo. BM from green fluorescence protein (GFP)-transgenic mice was transplanted to irradiated WT mice. GFP-BM chimera mice were subjected to wire injury on the left femoral artery. ATII (100 ng/kg/min) stimulated whereas CV11974 (1 mg/kg/d) inhibited neointimal formation. Number of GFP+ alphaSMA+ cells at neointima correlated with the intima/media ratio (r=0.69, P<0.05). CONCLUSION: BM-derived SM-like progenitor cells contributed to the neointimal formation after arterial injury. ATII accelerated whereas ARB suppressed this process. These are new aspects of the ARB-mediated inhibition of atherosclerotic disease progression.
  • Takaoka Minoru, Sata Masataka, Nagai Ryozo
    CIRCULATION 116(16) 208 2007年10月16日  査読有り
  • Enomoto Soichire, Sata Masataka, Sumi Makoto, Asakura Tetsuo, Nagai Ryozo
    CIRCULATION 116(16) 157 2007年10月16日  査読有り
  • Iwata Hiroshi, Manabe Ichire, Fujiu Katsuhito, Yamamoto Tetsufumi, Takeda Norifurni, Kuro-O Makoto, Sata Masataka, Nagai Ryozo
    CIRCULATION 116(16) 71 2007年10月16日  査読有り
  • Sahara Makoto, Sata Masataka, Morita Toshihiro, Hirata Yasunobu, Nagai Ryozo
    CIRCULATION 116(16) 242 2007年10月16日  査読有り
  • Shiga Taro, Maemura Koji, Imai Yasushi, Kawanami Daiji, Takeda Norihiko, Ando Jiro, Morita Toshihiro, Manabe Ichiro, Hayashi Dobun, Sugiyama Akira, Miyamoto Kyoko, Sagara Mina, Ito Yukio, Yamazaki Tsutomu, Hirata Yasunobu, Kodama Tatsuhiko, Nagai Ryozo
    CIRCULATION 116(16) 363 2007年10月16日  査読有り
  • Wang Guoqin, Watanabe Masafumi, Imaj Yasushi, Hara Kazuo, Manabe Ichiro, Maemura Koji, Matsumoto Sahohime, Horikoshi Momoko, Kadowaki Takashi, Yamazaki Tsutomu, Nagai Ryozo
    CIRCULATION 116(16) 507-507 2007年10月16日  査読有り
  • Nobukazu Ishizaka, Yuko Ishizaka, Ei-Ichi Toda, Ryozo Nagai, Kazuhiko Koike, Hideki Hashimoto, Minoru Yamakado
    Diabetes Research and Clinical Practice 78(1) 72-76 2007年10月  査読有り
    We found that cigarette smoking increased white blood cell count, and individuals which increased white blood cell count more likely to have metabolic syndrome in Japanese men. We investigated whether similar relationship can be observed also in women. We analyzed the data from 16,383 Japanese women who underwent general health screening. Age-adjusted logistic regression analysis showed that current smoking was positively associated with a highest white blood cell count quartile with an odds ratio of 2.40 (95% CI: 2.16-2.68, P &lt 0.0001). The white blood cell count showed a graded association with metabolic syndrome. On the other hand, the association between current smoking and metabolic syndrome was no longer significant after subdividing the individuals into groups according to the white blood cell quartile. These data collectively suggested that the association between current smoking and metabolic syndrome is heavily confounded by certain factors that increase the circulating white blood cell count in Japanese women, as in men. © 2007 Elsevier Ireland Ltd. All rights reserved.
  • Yuki Ohmoto-Sekine, Jun-ichi Suzuki, Ryoichi Shimamoto, Tadashi Yamazaki, Taeko Tsuji, Ryozo Nagai, Kuni Ohtomo
    Gender Medicine 4(3) 274-283 2007年9月  査読有り
    Background: Despite male predominance in the prevalence of hypertrophic cardiomyopathy (HCM), repeated diagnosis at our institute indicates a possible higher prevalence of deep Q waves with HCM in women. Objective: The current study examined gender similarities and differences in the prevalence of deep Q waves in HCM and in the morphologic and electrocardiographic features of HCM with deep Q waves. Methods: Patients with HCM underwent cardiac magnetic resonance (CMR) imaging to identify the prevalence of deep Q waves in electrocardiographic limb leads, and to analyze the relationship between distribution patterns of deep Q waves and those of the localization of maximum amplitude of left ventricular (LV) hypertrophy. Contiguous LV short-axis images were obtained from the base toward the apex. Results: Of the 200 consecutive patients (172 males, aged 20-78 years 28 females, aged 16-79 years) with HCM who underwent CMR imaging, 10 male and 8 female patients had deep Q waves. Deep Q waves were more prevalent in females with HCM than in their male counterparts (28.6% vs 5.8%, respectively P &lt 0.001). Of the 18 patients with deep Q waves, maximum wall thickness was localized at either the basal anterior wall or the midventricular septum in 9 (90%) of the 10 male patients and 6 (75%) of the 8 female patients. In both sexes, the Q wave distribution pattern of I and aVL and of II and aVF indicated localization of maximum hypertrophy at the midventricular septum in 6 (75%) of the 8 patients with the former pattern, and at the basal anterior wall in 9 (90%) of the 10 patients with the latter pattern. Conclusions: Diagnostic deep Q waves were detected more frequently in female patients with HCM than in their male counterparts. In HCM with deep Q waves in limb leads, morphologic and electrocardiographic analysis showed similar features in both sexes. (Gend Med. Keywords: deep Q wave, hypertrophic cardiomyopathy, gender, cardiac magnetic resonance. © 2007 Excerpta Medica, Inc.
  • 岩田 洋, 佐田 政隆, 真鍋 一郎, 藤生 克人, 武田 憲文, 永井 良三
    脈管学 47(Suppl.) S112-S112 2007年9月  査読有り
  • Nobukazu Ishizaka, Yuko Ishizaka, Ei-Ichi Toda, Ryozo Nagai, Minoru Yamakado
    Internal Medicine 46(15) 1167-1172 2007年8月2日  査読有り
    Objective: Cigarette smoking increases the circulating white blood cell (WBC) count and the prevalence of metabolic syndrome. We investigated the association between cigarette smoking, WBC count, and metabolic syndrome as defined by the Japanese criteria. Method: Cross-sectional data from 3,687 men undergoing general health screening between 2005 and 2006 were analyzed. Results: After adjustment for age and total cholesterol, former and current smoking were associated with the highest WBC quartile (≥6.3 × 103 cells/μL) with an odds ratio of 1.35 (95% CI 1.09-1.66, P=0.0055) and 4.45 (95% CI 3.69-5.37, P&lt 0.0001), respectively. It was found that increased WBC count was a risk factor for metabolic syndrome on the other hand, the current smoking was not found to be a predictor for metabolic syndrome, when each WBC count quartile was separately analyzed. Conclusions: Our data suggest that the risk for MetS, defined by Japanese criteria, might be estimated by the WBC count in Japanese men irrespective of their smoking status, although it should also be noted that the cigarette smoking increases the number of circulating WBC count. © 2007 The Japanese Society of Internal Medicine.
  • 東邦 康智, 石坂 信和, 石坂 裕子, 遠田 栄一, 永井 良三, 山門 実
    Journal of Cardiology 50(Suppl.I) 355-355 2007年8月  
  • Nobukazu Ishizaka, Yuko Ishizaka, Ryozo Nagai, Ei-Ichi Toda, Hideki Hashimoto, Minoru Yamakado
    ATHEROSCLEROSIS 193(2) 373-379 2007年8月  査読有り
    Serum albumin is a maker of nutritional status and possesses antioxidative properties. Here, we have sought to investigate the mode of association between serum albumin levels, metabolic syndrome, and carotid atherosclerosis by analyzing the data of the cross-sectional data from 8143 individuals who underwent general health screening test. After adjusting for age, total cholesterol, and smoking status, the highest quartile of serum albumin (&gt;= 4.7 g/dL) was associated with increased prevalence of metabolic syndrome with an odds ratio of 1.80 (95% CI 1.41-2.23, P &lt; 0.0001) in women, and 1.60 (95% CI 1.44-1.78, P &lt; 0.0001) in men, when compared to the lowest serum albumin quartile (&lt; 4.3 g/dL). By contrast, when compared with the lowest quartile, the highest quartile of serum albumin was associated with reduced prevalence of carotid plaque with an odds ratio of 0.62 (95% CI 0.42-0.9 1, P &lt; 0.001) in women, and 0.76 (95% CI 0.62-0.93, P &lt; 0.0 1) in men, and for carotid intima-media thickening with an odds ratio of 0.57 (95% CI 0.35-0.94, P &lt; 0.05) in women, and 0.71 (95% CI 0.55-0.92, P &lt; 0.0 1) in men. Our data showed that higher serum albumin was inversely associated with the prevalence of early carotid atherosclerosis, although it was positively associated with the prevalence of metabolic syndrome. Whether these observations are in part explained by the antioxidative properties of albumin requires further investigation. (c) 2006 Elsevier Ireland Ltd. All rights reserved.
  • Yoshinori Seko, Hideo Yagita, Ko Okumura, Miyuki Azuma, Ryozo Nagai
    Cardiovascular Research 75(1) 158-167 2007年7月1日  査読有り
    Objective: This study was designed to investigate the roles of programmed death-1 (PD-1) and PD-1ligands (PD-L) in the development of murine acute myocarditis caused by Coxsackievirus B3. PD-1/PD-L belong to the CD28/B7 superfamily, and the PD-1/PD-L pathway is known to transduce a negative immunoregulatory signal that antagonizes the T-cell receptor-CD28 signal and inhibits T-cell activation. Methods: We first analyzed the expression of PD-L1/PD-L2 on cardiac myocytes in vivo and in vitro. Second, we examined the effects of in vivo treatment with an anti-PD-1, PD-L1, or PD-L2 monoclonal antibodies on the development of myocardial inflammation in C3H/He mice infected with Coxsackievirus B3. Third, to investigate the effects of anti-PD-1 monoclonal antibody treatment on the activation of the infiltrating cells, we examined the expression of interleukin (IL)-2, interferon (IFN)-γ, CD40 ligand (CD40L), Fas ligand (FasL), and perforin as activation markers in mouse hearts by a semiquantitative PCR method. Results: PD-L1 was markedly induced on cardiac myocytes with acute myocarditis. In vivo anti-PD-1 or -PD-L1 blocking monoclonal antibody treatment increased the myocardial inflammation whereas anti-PD-1 stimulating monoclonal antibody treatment decreased the myocardial inflammation, and anti-PD-L2 monoclonal antibody treatment had no effect. Anti-PD-1 monoclonal antibody treatment significantly increased the expression of IFN-γ, FasL, CD40L, perforin, and Coxsackievirus B3 genomes in myocardial tissue. Conclusion: Our findings strongly suggest that the PD-1/PD-L1 pathway played a pivotal role in suppressing myocardial inflammation and raise the possibility of immunotherapy by stimulating the PD-1/PD-L1 pathway to prevent myocardial damage in viral myocarditis. © 2007 European Society of Cardiology.
  • Nanae Kada, Toru Suzuki, Kenichi Aizawa, Takayoshi Matsumura, Naoto Ishibashi, Naomi Suzuki, Norifumi Takeda, Yoshiko Munemasa, Daigo Sawaki, Takashi Ishikawa, Ryozo Nagai
    Arteriosclerosis, thrombosis, and vascular biology 27(7) 1535-41 2007年7月  査読有り
    OBJECTIVES: Acyclic retinoid (ACR) is a synthetic retinoid with a high safety profile that has been pursued with high expectations for therapeutic use in prevention (recurrence) and treatment of malignancies. With the objective of addressing the therapeutic potential in the cardiovasculature, namely neointima formation, effects of ACR on neointima formation and the involved mechanisms were investigated. METHODS AND RESULTS: ACR was administered to cuff-injured mice which showed inhibition of neointima formation. Investigation of involved mechanisms at the cellular and molecular levels showed that ACR induces apoptosis of neointimal cells and this to be mediated by selective induction of retinoic-acid receptor beta (RARbeta) which shows growth inhibitory and proapoptotic effects on smooth muscle cells. CONCLUSION: We show that ACR inhibits neointima formation by inducing RARbeta which in turn inhibits cell growth and induces apoptosis. The retinoid, ACR, may be potentially exploitable for treatment and prevention of neointima formation.
  • Naoto Kubota, Wataru Yano, Tetsuya Kubota, Toshimasa Yamauchi, Shinsuke Itoh, Hiroki Kumagai, Hideki Kozono, Iseki Takamoto, Shiki Okamoto, Tetsuya Shiuchi, Ryo Suzuki, Hidemi Satoh, Atsushi Tsuchida, Masao Moroi, Kaoru Sugi, Tetsuo Noda, Hiroyuki Ebinuma, Yoichi Ueta, Tatsuya Kondo, Eiichi Araki, Osamu Ezaki, Ryozo Nagai, Kazuyuki Tobe, Yasuo Terauchi, Kohjiro Ueki, Yasuhiko Minokoshi, Takashi Kadowaki
    Cell metabolism 6(1) 55-68 2007年7月  査読有り
    Adiponectin has been shown to stimulate fatty acid oxidation and enhance insulin sensitivity through the activation of AMP-activated protein kinase (AMPK) in the peripheral tissues. The effects of adiponectin in the central nervous system, however, are still poorly understood. Here, we show that adiponectin enhances AMPK activity in the arcuate hypothalamus (ARH) via its receptor AdipoR1 to stimulate food intake; this stimulation of food intake by adiponectin was attenuated by dominant-negative AMPK expression in the ARH. Moreover, adiponectin also decreased energy expenditure. Adiponectin-deficient mice showed decreased AMPK phosphorylation in the ARH, decreased food intake, and increased energy expenditure, exhibiting resistance to high-fat-diet-induced obesity. Serum and cerebrospinal fluid levels of adiponectin and expression of AdipoR1 in the ARH were increased during fasting and decreased after refeeding. We conclude that adiponectin stimulates food intake and decreases energy expenditure during fasting through its effects in the central nervous system.
  • Motohiro Sekiya, Naoya Yahagi, Takashi Matsuzaka, Yoshinori Takeuchi, Yoshimi Nakagawa, Haruka Takahashi, Hiroaki Okazaki, Yoko Iizuka, Ken Ohashi, Takanari Gotoda, Shun Ishibashi, Ryozo Nagai, Tsutomu Yamazaki, Takashi Kadowaki, Nobuhiro Yamada, Jun-ichi Osuga, Hitoshi Shimano
    Journal of lipid research 48(7) 1581-91 2007年7月  査読有り
    Sterol regulatory element-binding protein (SREBP)-1c is now well established as a key transcription factor for the regulation of lipogenic enzyme genes such as FAS in hepatocytes. Meanwhile, the mechanisms of lipogenic gene regulation in adipocytes remain unclear. Here, we demonstrate that those in adipocytes are independent of SREBP-1c. In adipocytes, unlike in hepatocytes, the stimulation of SREBP-1c expression by liver X receptor agonist does not accompany lipogenic gene upregulation, although nuclear SREBP-1c protein is concomitantly increased, indicating that the activation process of SREBP-1c by the cleavage system is intact in adipocytes. Supportively, transcriptional activity of the mature form of SREBP-1c for the FAS promoter was negligible when measured by reporter analysis. As an underlying mechanism, accessibility of SREBP-1c to the functional elements was involved, because chromatin immunoprecipitation assays revealed that SREBP-1c does not bind to the functional SRE/E-box site on the FAS promoter in adipocytes. Moreover, genetic disruption of SREBP-1 did not cause any changes in lipogenic gene expression in adipose tissue. In summary, in adipocytes, unlike in hepatocytes, increments in nuclear SREBP-1c are not accompanied by transactivation of lipogenic genes; thus, SREBP-1c is not committed to the regulation of lipogenesis.
  • Kazuto Nakamura, Masataka Sata, Hiroshi Iwata, Yoshiki Sakai, Yasunobu Hirata, Kiyotaka Kugiyama, Ryozo Nagai
    Clinical science (London, England : 1979) 112(12) 607-16 2007年6月  査読有り
    It has been shown previously that administration of angiogenic growth factors as genes or proteins can augment collateral growth in ischaemic tissues. In the present study, we have investigated the effect of ONO-1301, a synthetic prostacyclin agonist with thromboxane-synthase-inhibitory activity, on expression of endogenous growth factors and angiogenesis. ONO-1301 induced secretion of HGF (hepatocyte growth factor) and VEGF (vascular endothelial growth factor) from cultured normal human dermal fibroblasts in a dose-dependent manner. Dibutyryl cAMP, an analogue of cAMP, and forskolin, an adenylate cyclase activator, mimicked the effect of ONO-1301. Conversely, Rp-cAMP (adenosine 3',5'-cyclic monophosphorothioate), an inhibitor of cAMP, partially inhibited the effect of ONO-1301, suggesting that cAMP mediated the effect of ONO-1301 in up-regulating the expression of HGF and VEGF, at least in part. ONO-1301 promoted tube-like formation by HUVECs (human umbilical vein endothelial cells) when co-cultured with fibroblasts, and the angiogenic effect of ONO-1301 was abrogated by administration of a neutralizing antibody against HGF or VEGF. To generate a slow-releasing form of ONO-1301, ONO-1301 was mixed with poly(DL-lactic-co-glycolic acid). The slow-releasing form of ONO-1301 was injected directly into the ischaemic myocardium of mice immediately after ligation of the left anterior descending artery. The slow-releasing form of ONO-1301 up-regulated HGF and VEGF expression and increased capillary density in the border zone (342.7+/-29.7 capillaries/mm(2) in controls compared with 557.2+/-26.7 capillaries/mm(2) in treated animals; P<0.01) at 7 days. The slow-releasing form of ONO-1301 ameliorated left ventricular enlargement after 28 days and improved survival rate. In conclusion, our results indicate that ONO-1301 up-regulated endogenous growth factors and promoted angiogenesis in response to acute ischaemia. Therefore ONO-1301 might have a therapeutic potential in treating ischaemic diseases.

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