Takashi Ohori

University of Toyama, Тояма, Toyama, Japan

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Publications (14)29.15 Total impact

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    ABSTRACT: Aim: Epicardial adipose tissue (EAT) is a pathogenic fat depot that may be associated with coronary atherosclerosis and cardiovascular events. Because eicosapentaenoic acid (EPA) has been reported to exert cardiovascular protective effects, we aimed to assess the effects of EPA on the volume of visceral adipose tissue, including EAT and abdominal visceral adipose tissue (AVAT), using multislice computed tomography (CT). Methods: In 30 patients with coronary artery diseases (9 women; mean age, 67.2±5.4 years), EAT and AVAT volumes were compared between the control group (n=15, conventional therapy) and the EPA group (n=15, conventional therapy plus purified EPA 1800 mg/day) during a six-month period. EAT was defined as any pixel that had CT attenuation of -150 to -30 Hounsfield units (HU) within the pericardial sac. Results: After the six-month follow-up, the serum EPA level increased from 59.9±18.8 to 177.2± 3.3 μg/mL in the EPA group (p<0.01), but no increase was noted in the control group. Similarly, the EPA/arachidonic acid (AA) ratio increased from 0.39±0.12 to 1.22±0.28 in the EPA group (p<0.01), with no significant increase in the control group. The AVAT and EAT volumes decreased in the EPA group but were unchanged in the control group (AVAT, -11.6±17.0 vs. +8.8±13.6 cm(2), p<0.01; EAT, -7.3±8.3 vs. +8.7±8.8 cm(3), p<0.01). Moreover, the change in the AVAT volume negatively correlated with the change in EPA (r=-0.58, p<0.01) and EPA/AA levels (r=-0.53, p<0.01). A similar negative correlation in these parameters was also observed for the EAT volume. Conclusions: Oral intake of purified EPA appears to be associated with reductions in EAT and AVAT volumes.
    Journal of atherosclerosis and thrombosis. 05/2014;
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    ABSTRACT: BACKGROUND: Repeated low-temperature sauna (Waon) therapy relieves ischemic symptoms in patients with peripheral arterial disease. We investigated whether Waon therapy could improve myocardial perfusion in patients with ischemia related to chronic total occlusion (CTO) of coronary arteries. METHODS: Twenty-four patients who had ischemia in the CTO-related area were examined. The severity of ischemia was quantified by thallium-201 myocardial perfusion scintigraphy with adenosine. The Waon group (n=16) was treated daily for three weeks with a 60°C far infrared-ray dry sauna bath for 15min and then kept in a bed covered with blankets for 30min. The control group (n=8) underwent myocardial perfusion scintigraphy twice with a three-week interval. RESULTS: In the control group, neither summed stress score (SSS) nor summed difference score (SDS) of myocardial scintigraphy changed. However, Waon therapy improved both SSS (16±7 to 9±6, p<0.01) and SDS (7±4 to 3±2, p<0.01), and the improvement was greater in patients with higher SSS and SDS scores at the baseline. Waon therapy extended treadmill exercise time (430±185 to 511±192s, p<0.01) and improved flow-mediated dilation of the brachial artery (4.1±1.3 to 5.9±1.8%, p<0.05), but tended to decrease the number of circulating CD34-positive bone marrow-derived cells. CONCLUSIONS: Waon therapy improves CTO-related myocardial ischemia in association with improvement of vascular endothelial function. This therapy could be a complementary and alternative tool in patients with severe coronary lesions not suitable for coronary intervention.
    International journal of cardiology 01/2012; · 6.18 Impact Factor
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    ABSTRACT: Repeated sauna treatment, known as Waon therapy, has been shown to improve cardiac function as well as exercise tolerance in patients with chronic heart failure. However, the underlying mechanisms of this therapy regarding these improvements remain to be elucidated. Forty-one patients with chronic heart failure (mean age 68.3 ± 13.5 years old) underwent Waon therapy 5 times a week for 3 weeks. Before and after treatment, a number of assessments were performed in all subjects: 6-minute walk test, echocardiography, determination of neurohumoral factors and number of circulating CD34(+) cells, and a flow-mediated dilation (FMD) test of endothelial function. Cardiopulmonary exercise testing was also performed in 20 patients. Waon therapy increased the left ventricular ejection fraction (from 30.4 ± 12.6% to 32.5% ± 12.8%, p = 0.023) and reduced plasma levels of norepinephrine (from 400 ± 258 to 300 ± 187 pg/ml, p = 0.015) and brain natriuretic peptide (from 550 ± 510 to 416 ± 431 pg/ml, p = 0.035). Waon therapy increased the 6-minute walk distance (from 337 ± 120 to 379 ± 126 m, p <0.001) in association with an improvement in FMD (from 3.5 ± 2.3% to 5.5% ± 2.7%, p <0.001) and an increase in the number of circulating CD34(+) cells (p = 0.025). Changes in 6-minute walk distance were correlated positively with those in the left ventricular ejection fraction and FMD and negatively with those in plasma levels of norepinephrine and brain natriuretic peptide levels. A multivariate analysis revealed that an increase in FMD was the only independent determinant of 6-minute walk distance improvement. Finally, Waon therapy significantly increased peak Vo(2), and this increase was also correlated with changes in FMD. In conclusion, repeated sauna therapy in patients with chronic heart failure improves exercise tolerance in association with improvement in endothelial function.
    The American journal of cardiology 09/2011; 109(1):100-4. · 3.58 Impact Factor
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    ABSTRACT: Repeated sauna therapy (ST) increases endothelial nitric oxide synthase (eNOS) activity and improves cardiac function in heart failure as well as peripheral blood flow in ischemic limbs. The present study investigates whether ST can increase coronary vascularity and thus attenuate cardiac remodeling after myocardial infarction (MI). We induced MI by ligating the left coronary artery of Wistar rats. The rats were placed in a far-infrared dry sauna at 41°C for 15 min and then at 34°C for 20 min once daily for 4 wk. Cardiac hemodynamic, histopathological, and gene analyses were performed. Despite the similar sizes of MI between the ST and non-ST groups (51.4 ± 0.3 vs. 51.1 ± 0.2%), ST reduced left ventricular (LV) end-diastolic (9.7 ± 0.4 vs. 10.7 ± 0.5 mm, P < 0.01) and end-systolic (8.6 ± 0.5 vs. 9.6 ± 0.6 mm, P < 0.01) dimensions and attenuated MI-induced increases in LV end-diastolic pressure. Cross-sectional areas of cardiomyocytes were smaller in ST rats and associated with a significant reduction in myocardial atrial natriuretic peptide mRNA levels. Vascular density was reduced in the noninfarcted myocardium of non-ST rats, and the density of cells positive for CD31 and for α-smooth muscle actin was decreased. These decreases were attenuated in ST rats compared with non-ST rats and associated with increases in myocardial eNOS and vascular endothelial growth factor mRNA levels. In conclusion, ST attenuates cardiac remodeling after MI, at least in part, through improving coronary vascularity in the noninfarcted myocardium. Repeated ST might serve as a novel noninvasive therapy for patients with MI.
    AJP Heart and Circulatory Physiology 05/2011; 301(2):H548-54. · 4.01 Impact Factor
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    ABSTRACT: Both statins and renin-angiotensin system (RAS) inhibitors inhibit atherosclerotic progression and reduce cardiovascular events. However, it remains unclear whether combination therapy of RAS inhibitor with statin could inhibit plaque progression more than statin alone. Using 64 multislice computed tomography, vessel wall areas (VWAs) and total vascular areas of the left main trunk (LMT) and proximal right coronary artery (RCA) and the thoracic descending aorta (TDA) were determined in patients with coronary artery disease before and after 2.0-year treatment with atorvastatin and candesartan (n=20) or with atorvastatin alone (n=16), although these patients had been treated with the combination therapy or statin alone at the study enrollment. Plasma levels of high sensitive C-reactive protein, matrix metalloproteinase-9, and urinary 8-iso-prostaglandin F2α were determined at the baseline. There were no significant differences in low-density lipoprotein and high-density lipoprotein cholesterol, C-reactive protein, matrix metalloproteinase-9, or urinary 8-iso-prostaglandin F2α levels between the two groups. Two years later, total vascular areas of TDA and RCA increased significantly in the atorvastatin group but not in the combination group. Moreover, increases in VWAs were less in the combination group than in the atorvastatin group in TDA (3.6 ± 23.1 vs. 28.6 ± 25.5 mm, P=0.004), RCA (-1.6 ±1.6 vs. 0.6 ± 2.5 mm, P=0.005), and left main trunk (-0.9 ± 3.5 vs. 1.3 ± 2.4 mm, P=0.095). Biomarker levels at the baseline did not affect the progression of VWA. Combination therapy of RAS inhibitor with statin is more effective than statin alone in inhibiting atherosclerotic progression of coronary arteries and the aorta in patients with coronary artery disease.
    Coronary artery disease 04/2011; 22(5):352-8. · 1.56 Impact Factor
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    ABSTRACT: The responses of sympathetic nerve activity to transient stress can be exaggerated in salt-sensitive (SS), hypertensive subjects. Cardiac and renal interstitial norepinephrine (iNE) levels during and after transient hypercapnia were investigated in conscious SS rats. Dahl SS and salt-resistant (SR) 6-wk-old rats were fed a high-salt diet, and at 12 wk iNE levels in the heart and kidney were determined using microdialysis with probes inserted in the left ventricular (LV) wall and kidney. A telemetry system determined blood pressure and heart rate (HR) in separate animals. After recovery from the operation, data were collected before, during, and after exposure to normoxic 10% CO(2) for 25 min under unanesthetized conditions. The plasma NE concentrations at baseline did not differ between the two strains. Both cardiac and renal iNE levels were much higher in SS rats than in SR rats at baseline as well as during hypercapnic stress. After stress, the markedly increased iNE levels of SS rats were prolonged in the LV as well as in the kidney. During hypercapnic stress, HR decreased in both SS and SR rats, while sudden increases in HR immediately after the withdrawal from stress were followed by its slower reduction in SS rats compared with SR rats. In conclusion, transient hypercapnic stress causes exaggerated and prolonged elevation of iNE levels in the heart as well as in kidneys of SS animals.
    AJP Heart and Circulatory Physiology 03/2011; 300(6):H2214-20. · 4.01 Impact Factor
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    ABSTRACT: Cardiovascular events are characterized by circadian periodicity with a peak prevalence during the awakening period, which suggests a morning surge in sympathetic activity. We developed an experimental system to determine circadian changes in heart rate (HR), blood pressure (BP), locomotor activity (Loc), respiratory rate and autonomic function in conscious, unrestrained rats. The effects of amiodarone on circadian variation of these variables were determined in rats with myocardial infarction and subsequent congestive heart failure (CHF). We continuously recorded BP, HR and Loc for 24h in rats with CHF (n=16) or after a sham operation (Sham; n=7). To determine circadian changes in sympathovagal balance, digitized BP and HR data throughout 24h were analyzed based on maximum entropy. The study was repeated after 3 weeks of oral amiodarone (50mg/kg/day) or saline administration. Baseline HR, mean BP, and Loc were higher in the dark period than in the light period (all p<0.05) in both CHF and Sham rats, which is consistent with the circadian periodicity of nocturnal animals. Low-frequency components of diastolic BP variability (LFdp), an index of sympathetic tone, were significantly higher during the awakening period (16:00-20:00) than during the sleeping period (08:00-14:00), a finding analogous to the sympathetic morning surge in men. Amiodarone suppressed this transient increase in LFdp power during the awakening period. Our experimental system could detect sympathetic surge in conscious rats. Amiodarone suppressed the sympathetic surge, which could explain, at least in part, beneficial effects of amiodarone in patients with CHF.
    Autonomic neuroscience: basic & clinical 01/2011; 159(1-2):20-5. · 1.82 Impact Factor
  • Journal of Cardiac Failure - J CARD FAIL. 01/2011; 17(9).
  • Journal of Cardiac Failure - J CARD FAIL. 01/2011; 17(9).
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    ABSTRACT: Myocardial perfusion imaging shows various patterns in patients with non-ischemic dilated cardiomyopathy (DCM). However, influences of regional abnormalities of myocardial perfusion or ventricular wall motion on prognosis in DCM patients remains to be clarified. Accordingly, we investigated a relation between myocardial perfusion patterns and long-term prognosis in DCM patients. Sixty-two patients were divided into 2 groups according to patterns of (99m)Tc-Tetrofosmin scintigraphy, i.e. large focal defects (focal) and minimally impaired perfusion or multiple small defects (non-focal). There were no differences between the 2 groups in left ventricular (LV) end-diastolic dimensions (63.4 ± 9.1 and 63.8.4 ± 7.5mm, respectively) and LV ejection fraction (30.3 ± 9.2 and 27.9 ± 7.8%, respectively), indicating LV systolic dysfunction was comparable between the groups. The focal group had a higher prevalence of brain natriuretic peptide ≧ 200 ng/dl and plasma norepinephrine ≧ 500 pg/ml than the non-focal group (p<0.05), and had longer QRS durations (p<0.05). The focal group had non-sustained ventricular tachycardia (VT) (p<0.05) on 24-h electrocardiogram recording and a history of VT/ventricular fibrillation more frequently (p<0.05), and had higher New York Heart Association functional class than the non-focal group (p<0.05). The mortality was significantly higher in the focal group (56.0%) than in the non-focal group (28.6%) and the survival curves revealed worse prognosis in the focal group during a follow-up period of 5.3 ± 2.8 years. Non-ischemic DCM patients with focal defects are accompanied by more advanced heart failure and poor prognosis compared to those with minimally impaired perfusion or multiple small defects, despite comparable LV systolic dysfunction.
    Journal of Cardiology 11/2010; 56(3):280-6. · 2.30 Impact Factor
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    ABSTRACT: It remains unclear whether atherosclerosis in one vascular bed progresses in parallel with that in other vascular beds. We investigated serial changes in vessel wall areas (VWAs) in various vessels over 2 years of follow-up. Vessel wall areas in the thoracic descending aorta (TDA), common carotid artery (CCA), right (RCA), and left main trunk (LMT) of coronary artery were determined in 52 patients with coronary artery disease (CAD) using 64-slice multidetector computed tomography. Plasma levels of high-sensitivity CRP (hs-CRP) and matrix metalloproteinase (MMP)-9, as well as urinary 8-iso-prostaglandin F2α (PGF2α) were determined at the baseline. After the follow-up period, plaque progression in a specific vessel did not parallel that of other vessels, although changes in TDA-VWAs were weakly correlated with those of LMT-VWAs. Basal levels of hs-CRP, MMP-9, and PGF2α did not predict progression or regression of VWAs in any vessels. Multivariate analyses showed that LDL-cholesterol < 100 mg/dl and use of statin emerged as predictors of regressing VWAs in TDA (p < 0.05 and p < 0.05, respectively) and LMT (p < 0.05 and p = 0.13, respectively). Changes in soft plaques over 2 years paralleled those of VWAs in both coronary arteries. In conclusion, the progression or regression of atherosclerotic plaques is inhomogeneous among the vascular beds of patients with CAD.
    Heart and Vessels 10/2010; 26(3):242-51. · 2.13 Impact Factor
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    ABSTRACT: Increased oxidative stress might contribute to diabetic (DM) neuropathy, so the effects of long-term treatment with fluvastatin (FL) on myocardial oxidative stress and cardiac sympathetic neural function were investigated in diabetic rats. FL (10 mg . kg(-1) . day(-1), DM-FL) or vehicle (DM-VE) was orally administered for 2 weeks to streptozotocin-induced DM rats. Cardiac oxidative stress was determined by myocardial 8-iso-prostaglandin F(2alpha) (PGF(2alpha)) and NADPH oxidase subunit p22(phox) mRNA expression. Sympathetic neural function was quantified by autoradiography using (131)I- and (125)I-metaiodobenzylguanidine (MIBG). FL did not affect plasma glucose levels but remarkably decreased PGF(2alpha) levels compared with DM-VE rats (13.8+/-9.2 vs 175.0+/-93.9 ng/g tissue), although PGF(2alpha) levels were below the detection limit in non-DM rats. FL significantly reduced myocardial p22(phox) mRNA expression. Cardiac (131)I-MIBG uptake was lower in DM-VE rats than in non-DM rats, but the decrease was attenuated in DM-FL rats (1.31+/-0.08, 1.88+/-0.22, and 1.58+/-0.18 %kg dose/g, respectively, P<0.01). Cardiac MIBG clearance was not affected by the induction of DM or by FL, indicating that the reduced MIBG uptake in DM rats might result from impaired neural function. FL ameliorates cardiac sympathetic neural dysfunction in DM rats in association with attenuation of increased myocardial oxidative stress.
    Circulation Journal 03/2010; 74(3):468-75. · 3.58 Impact Factor
  • Journal of Cardiac Failure - J CARD FAIL. 01/2010; 16(9).
  • Journal of Cardiac Failure - J CARD FAIL. 01/2009; 15(7).