Kazuyuki Shirai
Fukuoka University
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Featured researches published by Kazuyuki Shirai.
Annals of Epidemiology | 2000
Shizuka Sasazuki; Hiroko Kodama; Kouichi Yoshimasu; Ying Liu; Masakazu Washio; Keitaro Tanaka; Shoji Tokunaga; Suminori Kono; Hidekazu Arai; Yoshitaka Doi; Tomoki Kawano; Osamu Nakagaki; Kazuyuki Takada; Samon Koyanagi; Koji Hiyamuta; Takanobu Nii; Kazuyuki Shirai; Munehito Ideishi; Kikuo Arakawa; Masahiro Mohri; Akira Takeshita
PURPOSE To examine the relation between green tea consumption and arteriographically determined coronary atherosclerosis. METHODS Study subjects were 512 patients (302 men and 210 women) aged 30 years or older who underwent coronary arteriography for the first time at four hospitals in Fukuoka City or one hospital in an adjacent city between September 1996 and August 1997. Lifestyle characteristics including green tea consumption were ascertained before arteriography by a questionnaire supported with interview. RESULTS 117 men (38.7%) and 50 women (23.8%) had significant stenosis of one or more coronary arteries. Green tea consumption tended to be inversely associated with coronary atherosclerosis in men, but not in women. An evident, protective association between green tea and coronary atherosclerosis was observed in a subgroup of 262 men excluding those under dietary or drug treatment for diabetes mellitus. In this subgroup, after adjustment for traditional coronary risk factors and coffee, odds ratios of significant stenosis for consumption of 2-3 cups and 4 or more cups per day were 0.5 (95% confidence interval 0.2-1.2) and 0.4 (0.2-0.9), respectively, as compared with a consumption of one cup per day or less. CONCLUSIONS The results indicate that green tea may be protective against coronary atherosclerosis at least in men.
The Cardiology | 2000
Makoto Ihara; Hidenori Urata; Kazuyuki Shirai; Munehito Ideishi; Fumihiro Hoshino; Junji Suzumiya; Masahiro Kikuchi; Kikuo Arakawa
The aims of this study were to compare human cardiac angiotensin-II-forming activity (AIIFA) between the intact area of control autopsy hearts without cardiac disease (n = 10) and the infarcted or non-infarcted area of autopsy hearts with myocardial infarction (MI, n = 7) and to determine responsible angiotensin-II-forming enzymes. Cardiac total and chymase-dependent AIIFAs were significantly higher in the infarcted and non-infarcted myocardium than those in non-MI heart, while angiotensin-converting enzyme-dependent AIIFA increased only in the infarcted myocardium. The density of chymase antibody-positive mast cells in the non-infarcted area of MI heart correlated positively with total or chymase-dependent AIIFA. Augmented AIIFA was also detected in the left atrium of post-MI hearts. Our results indicated that cardiac angiotensin II formation could be activated in the infarcted as well as in non-infarcted myocardium of the post-MI human heart.
Angiology | 2000
Hiroaki Nishikawa; Munehito Ideishi; Taku Nishimura; Akira Kawamura; Hideyuki Kamochi; Hisafumi Tahara; Yoshihiro Tsuchiya; Kazuyuki Shirai; Masanori Okabe; Kikuo Arakawa
A 51-year-old woman with a large uterine myoma suffered from acute pulmonary throm boembolism. Venography revealed thrombosis in the right common iliac vein and almost complete obstruction of the left common iliac vein. The ascending lumbar vein showed collateral drainage. Treatment was initiated with continuous intravenous heparin sodium, and a Greenfield filter was inserted to prevent the extension of the pulmonary embolism during and after hysterectomy. After a total hysterectomy, venography revealed restora tion of patency in the bilateral common iliac veins, and no flow was seen in the ascending lumbar vein. Thorough clinical examinations failed to identify any other prothrombotic conditions. These results suggest that a large uterine myoma compressed veins in the pelvis, and the resulting impaired blood flow caused deep venous thrombosis and pulmonary thromboembolism.
Journal of Lipid Research | 2009
Bo Zhang; Akira Matsunaga; David L. Rainwater; Shin-ichiro Miura; Keita Noda; Hiroaki Nishikawa; Yoshinari Uehara; Kazuyuki Shirai; Masahiro Ogawa; Keijiro Saku
Electronegative LDL, a charge-modified LDL (cm-LDL) subfraction that is more negatively charged than normal LDL, has been shown to be inflammatory. We previously showed that pravastatin and simvastatin reduced the electronegative LDL subfraction, fast-migrating LDL (fLDL), as analyzed by capillary isotachophoresis (cITP). The present study examined the effects of rosuvastatin on the more electronegative LDL subfraction, very-fast-migrating LDL (vfLDL), and small, dense charge-modified LDL (sd-cm-LDL) subfractions. Patients with hypercholesterolemia or those who were being treated with statins (n = 81) were treated with or switched to 2.5 mg/d rosuvastatin for 3 months. Rosuvastatin treatment effectively reduced cITP cm-LDL subfractions of LDL (vfLDL and fLDL) or sdLDL (sd-vfLDL and sd-fLDL), which were closely related to each other but were different from the normal subfraction of LDL [slow-migrating LDL (sLDL)] or sdLDL (sd-sLDL) in their relation to the levels of remnant-like particle cholesterol (RLP-C), apolipoprotein (apo) C-II, and apoE. The percent changes in cm-LDL or sd-cm-LDL caused by rosuvastatin were correlated with those in the particle concentrations of LDL or sdLDL measured as LDL-apoB or sdLDL-apoB and the levels of HDL-C, RLP-C, apoC-II, and apoE. In conclusion, rosuvastatin effectively reduced both the vfLDL subfraction and sd-cm-LDL subfractions as analyzed by cITP.
International Journal of Obesity | 2001
Keitaro Tanaka; Hiroko Kodama; Shizuka Sasazuki; Kouichi Yoshimasu; Y Liu; Masakazu Washio; Shoji Tokunaga; Suminori Kono; Hidekazu Arai; Samon Koyanagi; Koji Hiyamuta; Yoshitaka Doi; Tomoki Kawano; Osamu Nakagaki; Kazuyuki Takada; Takanobu Nii; Kazuyuki Shirai; Munehito Ideishi; Kikuo Arakawa; Masahiro Mohri; Akira Takeshita
OBJECTIVE: To investigate the relation of the obesity and body-fat distribution with angiographically defined coronary atherosclerosis.DESIGN: Cross-sectional study in a clinical setting.SUBJECTS: Three hundred and twenty men (median age, 59 y) and 212 women (median age, 67 y) who underwent coronary angiography for suspected or known coronary heart disease at 5 cardiology departments between September 1996 and August 1997. Patients with disease duration >1 y were excluded.MEASUREMENTS: The body mass index (BMI) and the waist to hip circumference ratio (WHR) were used as main exposure variables, and either the presence of significant coronary stenosis or the Gensinis score (≥10 vs<10) as an outcome variable, in a sex-specific multiple logistic regression analysis controlling for age, hospital, and other coronary risk factors.RESULTS: Among male patients, BMI was progressively higher with an increasing number of vessels involved (P trend=0.05); the adjusted odds ratios for the presence of significant stenosis across quartiles of BMI were 1.0 (reference), 1.1, 1.9 and 2.5 (P trend=0.02), and the positive association was more pronounced for younger patients. Among females, however, such associations were not evident. Employing the Gensinis score as an outcome gave similar results. WHR was not significantly associated with either outcome regardless of sex.CONCLUSION: These results suggested that BMI was predictive of coronary stenosis among male patients, but not among female patients. Unlike most previous studies, this study failed to detect a positive association with WHR.
Atherosclerosis | 2008
Bo Zhang; Shin-ichiro Miura; Daizaburo Yanagi; Keita Noda; Hiroaki Nishikawa; Akira Matsunaga; Kazuyuki Shirai; Atsushi Iwata; Kazuhiko Yoshinaga; Hisashi Adachi; Tsutomu Imaizumi; Keijiro Saku
Various forms of atherogenic modified low-density lipoprotein (LDL) including oxidized LDL and small, dense LDL have increased negative charge as compared to normal LDL. Charge-modified LDL (electronegative LDL) and normal LDL subfractions in plasma are analyzed by capillary isotachophoresis (cITP) as fast-migrating LDL (fLDL) and slow-migrating LDL (sLDL). We examined the effects of pravastatin and simvastatin on charge-based LDL subfractions as determined by cITP in patients with hypercholesterolemia. Patients (n=72) with CHD or CHD risk factors and elevated LDL cholesterol (LDL-C) levels were randomly assigned to receive pravastatin or simvastatin. After treatment with statins for 3 and 6 months, both cITP fLDL and sLDL were reduced (p<0.05) from the baseline, but the effects did not differ between treatment with pravastatin and simvastatin. At baseline and after treatment for 3 months, cITP sLDL was correlated with LDL-C, but fLDL was correlated with inflammatory markers, high-sensitive C-reactive protein and LDL-associated platelet-activating factor acetylhydrolase, and atherogenic lipoproteins, remnant-like particle cholesterol and small, dense LDL cholesterol. In conclusion, cITP fLDL was related to inflammatory markers and atherogenic lipoproteins and was reduced by treatment with statins. Charge-modified LDL subfraction could be a potential marker for atherosclerosis and a target for therapy.
Journal of Psychosomatic Research | 2000
Kouichi Yoshimasu; Ying Liu; Hiroko Kodama; Shizuka Sasazuki; Masakazu Washio; Keitaro Tanaka; Shoji Tokunaga; Suminori Kono; Hidekazu Arai; Samon Koyanagi; Koji Hiyamuta; Yoshitaka Doi; Tomoki Kawano; Osamu Nakagaki; Kazuyuki Takada; Takanobu Nii; Kazuyuki Shirai; Munehito Ideishi; Kikuo Arakawa; Masahiro Mohri; Akira Takeshita
OBJECTIVE To examine the relation of type A behavior pattern and job strain to angiographically documented coronary stenosis. METHODS Subjects were 197 male Japanese patients with a full-time job. A questionnaire-based interview elicited psychosocial and other factors. Type A behavior pattern was measured by 12 questions, and job strain by the method of Karasek. Significant coronary stenosis was defined when a 75% or greater luminal narrowing occurred at one or more major coronary arteries or when a 50% or greater narrowing occurred at the left main artery. Logistic regression analysis was used to calculate odds ratio (OR) and 95% confidence interval (CI) with adjustment for traditional coronary risk factors and job type. RESULTS Type A behavior pattern was related to a statistically non-significant lower prevalence of the coronary stenosis especially in the absence of job strain (adjusted OR 0.6, 95% CI 0.3-1.2). Job strain was non-significantly associated with a modestly increased prevalence of coronary stenosis (OR 1.7, 95% CI 0.6-5.2). CONCLUSION These findings suggest that both the behavioral pattern and psychosocial work environment may be related to coronary artery stenosis.
Journal of the American College of Cardiology | 1999
Keijiro Saku; Bo Zhang; Kazuyuki Shirai; Shiro Jimi; Kazuhiko Yoshinaga; Kikuo Arakawa
OBJECTIVES The purpose of this study was to investigate the association among insulin resistance, high density lipoprotein cholesterol (HDL-C) and coronary heart disease (CHD), and to test the hypothesis that HDL-C may ameliorate the adverse effects of insulin. BACKGROUND Serum low HDL-C (hypoalphalipoproteinemia) and hyperinsulinemia are independent predictors for CHD, but a strong negative correlation exists between them, as in patients with syndrome X. METHODS Fifty-four pairs of cases (M/F: 49/5), defined as patients with angiographically proved CHD, and control subjects (M/F: 49/5) matched with cases with regard to gender and age were included. Insulin resistance was assessed by the homeostasis model assessment (HOMA). RESULTS Cases had increased HOMA insulin resistance and lower serum levels of HDL-C than controls. A receiver operating characteristic (ROC) curve analysis indicated that HDL-C and insulin resistance were significant discriminators of CHD (area under ROC curve: 0.72 and 0.69, respectively). The interaction between HDL-C and the association of insulin resistance with CHD was significant: subjects with hyperinsulinemia and high HDL-C had no increased risk of CHD. Multivariate conditional logistic regression analysis showed that hyperinsulinemic hypoalphalipoproteinemia was a stronger indicator for CHD than either HDL-C or insulin resistance alone (-2 log likelihood: 19.0 vs. 12.6 or 15.7). CONCLUSIONS Hyperinsulinemic hypoalphalipoproteinemia was a more potent indicator for CHD than either insulin resistance or low serum HDL-C levels alone, and the adverse effects of hyperinsulinemia seem to be ameliorated by high HDL-C levels.
Journal of Cardiology | 2008
Yusuke Fukuda; Kazuyuki Shirai; Yosuke Takamiya; Miller Nathan; Takahiro Mito; Daizaburo Yamagi; Satoru Hida; Atsushi Iwata; Tomoo Yasuda; Bo Zang; Hiroaki Nishikawa; Munehito Ideishi; Keijiro Saku
Takayasus arteritis has often been difficult to diagnose because of a lack of typical symptoms and other specific makers. We report here a case of Takayasus arteritis in a 73-year-old man who was considered to exhibit isolated pulmonary artery involvement. Pulmonary hypertension and right heart failure and severe stenosis in the main trunk and left pulmonary artery were observed. There was nothing remarkable in his routine blood-sample tests other than increased CRP and ESR. There were neither infectious nor collagen diseases. Anti-cardiolipin antibody, Antiphospholipid Syndrome, PR3-ANCA and MPO-ANCA were negative. We diagnosed the patient as having Takayasus arteritis based on chronic inflammation and the morphologic features of pulmonary artery lesion. However, other large vessels and the aorta were not involved. Treatment was started with glucocorticoids. The symptoms gradually improved, and pulmonary artery pressure estimated by echocardiography decreased along with inflammatiory markers. There were no remarkable changes in the stenotic lesions in the pulmonary artery but the flow limit in the left pulmonary artery was improved.
American Journal of Hypertension | 1999
Takanobu Takezako; Keijiro Saku; Bo Zhang; Jiafu Ou; Kimiko Imai; Shiro Jimi; Kazuyuki Shirai; Kikuo Arakawa
The association between insertion/deletion polymorphism of the angiotensin I converting enzyme (ACE) gene and insulin resistance (IR) was investigated in 64 consecutive patients (F/M: 11/53) with angina pectoris without clinically manifest diabetes mellitus who underwent diagnostic coronary angiography. The observed frequency distribution of ACE genotypes did not deviate from that predicted from the Hardy-Weinberg equilibrium in this group. Patients with the ACE-ID genotype had significantly lower IR, as assessed by an oral glucose tolerance test (OGTT) and by homeostatic model assessment (HOMA), compared to those with the ACE-II genotype, as assessed by a multiple comparison analysis. Patients were divided into two groups with low and high HOMA-IR, and the I allele was seen more frequently in the high HOMA-IR group than in the low HOMA-IR group (0.62 v 0.47, respectively, by chi2 test, P < .05). Logistic regression analysis showed that the odds ratio for insulin resistance in patients with the II genotype, compared to those with the ID and DD-genotypes (assuming that the I allele has a recessive effect), was 4.0 (95% confidence interval, 1.2 to 16.5; P = .037), after adjusting for the presence of significant coronary atherosclerosis. In conclusion, the D allele was not associated with higher insulin resistance in patients with angina pectoris; that is, patients with the ID and DD genotypes were associated with a significantly lower risk of insulin resistance, compared to those with the II genotype.