Biomedical subjects

Naohito Tanabe

Publications and source records attributed to Naohito Tanabe.

25 records · Page 2Linked to original sources

PubMed2003

Event rates of acute myocardial infarction and coronary deaths in Niigata and Nagaoka cities in Japan.

Mortality from coronary heart disease in Japan is the among lowest recorded in the industrialized nations; however, little is known about the rate of events including nonfatal cases. A survey of event registration and a review of death certificates was carried out to estimate event rates of acute myocardial infarction (AMI) and coronary deaths in the largest 2 cities of the Niigata prefecture where there are 480,720 residents aged between 15 and 65 years. The definitions for these cardiac events used for the WHO-MONICA project were: (1)'definite AMI', (2) 'possible AMI or coronary death' (not including unclassifiable fatal events), and (3) 'unclassifiable fatal events'. Age-adjusted rates for AMI and coronary deaths (per 100,000/year) according to the registration survey were 54.6 for men and 7.2 for women according to definition 1 and 41.9 for men, and 5.3 for women according to definition 2. When data from the death certificate review were taken into account for the estimation, these rates increased to 80.6 for men and 14.2 for women according to definition 1, and 50.0 for men and 9.0 for women according to definition 2. These estimated rates are considerably lower than those in other industrialized nations surveyed in the WHO-MONICA project, and these findings are consistent with those from other studies conducted in Japan.

Adolescent↗

PubMed2003

Comparative effects of angiotensin II receptor blockade (candesartan) with angiotensin-converting enzyme inhibitor (quinapril) in rats with dilated cardiomyopathy.

Angiotensin II receptor blockers and angiotensin-converting enzyme inhibitors have been shown to reduce morbidity and mortality in patients with heart failure, but their inhibitory actions on angiotensin I-induced increases in blood pressure in heart failure are not clear. Angiotensin I blocking and cardioprotective properties of the angiotensin II receptor blocker candesartan and the angiotensin-converting enzyme inhibitor quinapril were studied in a rat model of dilated cardiomyopathy after autoimmune myocarditis. Low-dose candesartan (0.5 mg/kg) showed the same angiotensin I blocking action as high-dose quinapril (20 mg/kg) in rats with heart failure. Twenty-eight days after immunization, surviving Lewis rats (43/58, 74%) were divided into three groups and given quinapril at 20 mg/kg per day (group Q, n = 14), candesartan at 0.5 mg/kg per day (group C, n = 14) or vehicle alone (group V, n = 15). After oral administration for 1 month, four of 15 (27%) rats in group V and two of 14 (14%) in group C died. None of the animals in group Q died. Although angiotensin II levels of the blood and the left ventricle in group V [367 +/- 26 and 437 +/- 18% versus normal rats (group N)] were significantly higher than those in group N (both p < 0.01), they were reduced in group Q (88 +/- 32 and 169 +/- 53%, both p < 0.01). The left ventricular end-diastolic pressure and the area of myocardial fibrosis were lower, and the first derivative +/-dP/dt was higher in group Q (7.0 +/- 1.7 mmHg, 9 +/- 3% and +3451+/- 170/-3182 +/- 186 mmHg/s, respectively) than in group V (16.7 +/- 1.3 mmHg, 36 +/- 6% and +2601 +/- 235/-2156 +/- 257 mmHg/s, respectively) and in group C (11.2 +/- 2.0 mmHg, 26 +/- 4% and +3063 +/- 164/-2734 +/- 174 mmHg/s, respectively). Although levels of expression of transforming growth factor beta1 and collagen III mRNA in groupV (367 +/- 26 and 437 +/- 18% versus group N) were significantly higher than those in group N (both p < 0.01), they were reduced in group Q (88 +/- 32 and 169 +/- 53%, both p < 0.01). These results suggested that although low-dose candesartan can block increases in blood pressure with circulating angiotensin I to the same extent as high-dose quinapril, it does not confer sufficient protection against injury from the renin-angiotensin system in heart failure.

Angiotensin I↗

PubMed2003

Betaxolol improves the survival rate and changes natriuretic peptide expression in rats with heart failure.

The cardioprotective effects of betaxolol were studied in a rat model with heart failure induced by autoimmune myocarditis. Twenty-eight days after immunization, Lewis rats were divided into four groups; 0.1 mg/kg betaxolol per day (group 0.1), 1.0 mg/kg betaxolol per day (group 1), 10 mg/kg betaxolol per day (group 10), and vehicle (0.5% methylcellulose, group V) (all groups, n = 13). After oral administration for 1 month, the heart weight, the mRNA expression of atrial natriuretic peptide and brain natriuretic peptide in the left ventricle, the plasma atrial natriuretic peptide concentration, the mean blood pressure, the heart rate, the central venous pressure, the peak left ventricular pressure, the left ventricular end-diastolic pressure and its first derivative +/-dP/dt, and the area of myocardial fibrosis were measured. Betaxolol reduced the heart rate, the levels of atrial natriuretic peptide and brain natriuretic peptide mRNA expression and the atrial natriuretic peptide concentration [group N (normal rats), 367 +/- 4 beats/min, 100%, 100% and 78 +/- 7 pg/ml, respectively; group V, 391 +/- 9 beats/min, 761 +/- 68% versus group N, 317 +/- 42% versus group N and 4374 +/- 312 pg/ml, respectively; group 0.1, 387 +/- 10 beats/min, 621 +/- 78%, 288 +/- 41% and 2875 +/- 331 pg/ml, respectively; group 1, 323 +/- 9 beats/min, 442 +/- 84%, 148 +/- 12% and 884 +/- 51 pg/ml, respectively; and group 10, 312 +/- 8 beats/min, 97 +/- 18%, 92 + 9% and 453 +/- 53 pg/ml, respectively], and increased survival (group V, 62%; group 0.1, 69%; groups N, 1 and 10, 100%). Betaxolol did not significantly alter the heart weight, the hemodynamic parameters or the area of fibrosis. These observations suggest that betaxolol may improve the survival rate by reducing sudden death and changing the atrial natriuretic peptide and brain natriuretic peptide mRNA expression in patients with heart failure.

Animals↗

PubMed2002

Perceived mental stress and mortality from cardiovascular disease among Japanese men and women: the Japan Collaborative Cohort Study for Evaluation of Cancer Risk Sponsored by Monbusho (JACC Study).

BACKGROUND: Perceived mental stress has been associated with risk of coronary heart disease (CHD) in white men, but no prospective data are available for other ethnic groups. METHODS AND RESULTS: From 1988 to 1990, a total of 73 424 Japanese (30 180 men and 43 244 women), aged 40 to 79 years, without a history of stroke, CHD, or cancer completed a lifestyle questionnaire including perception of mental stress under the Japan Collaborative Cohort Study for Evaluation of Cancer Risk Sponsored by Monbusho (JACC Study). Systematic surveillance was completed until the end of 1997, with a 580 378 person-year follow-up, and the underlying causes of death were determined according to the International Classification of Diseases, 10th revision. For women, there were 316 with total stroke, 113 with CHD, and 643 with total cardiovascular disease (CVD); for men, there were 341, 168, and 778, respectively. Women who reported high stress had a 2-fold higher age-adjusted risk of mortality from total stroke and CHD and 1.5-fold higher risk of total CVD compared with those who reported low stress. Further adjustment for known cardiovascular risk factors and selected psychological variables did not alter the associations materially. The multivariate relative risk for women who perceived high stress versus low stress was 2.24 (95% CI 1.52 to 3.31, P<0.001) for total stroke, 2.28 (95% CI 1.17 to 4.43, P=0.02) for CHD, and 1.64 (95% CI 1.25 to 2.16, P<0.001) for total CVD. For men, these relations were generally weaker but suggestive of myocardial infarction. CONCLUSIONS: Perceived mental stress was associated with increased mortality from stroke for women and with CHD for men and women.

Adult↗

PubMed2002

The effectiveness of influenza vaccine against influenza a (H3N2) virus infections in nursing homes in Niigata, Japan, during the 1998-1999 and 1999-2000 seasons.

OBJECTIVE: To evaluate the effectiveness of influenza vaccines against influenza-like illness (ILI) among nursing home residents. DESIGN: Prospective, nonrandomized, cohort study. SETTING: Nine nursing homes during the 1998-1999 influenza season and 11 nursing homes during the 1999-2000 influenza season in Niigata Prefecture, Japan. PARTICIPANTS: Six hundred ninety-nine residents and 440 healthcare workers (HCWs) during the first season, and 930 residents and 517 HCWs during the second season, with vaccination rates ranging from 0% to 97.7%. RESULTS: Overall, ILI decreased from 24.3% during the 1998-1999 season to 8.8% during the 1999-2000 season. Multivariate analysis adjusted for several factors, including gender, age, underlying diseases, and resident and HCW vaccination rates, failed to demonstrate clear individual protection of residents (relative risk [RR], 1.42; P = .2 for the first season; RR, 0.95; P = .9 for the second season). However, vaccination rates of 60% or greater for residents and HCWs reduced the risk of ILI, and also could prevent outbreaks during the 2 seasons. Highly impaired activities of daily living and chronic respiratory diseases were significantly associated with increased ILI. CONCLUSIONS: A high vaccination rate for both residents and HCWs may reduce the risk of ILI and institutional outbreaks in nursing homes.

Aged↗

PubMed2002

Effects of carvedilol on cardiac function and cardiac adrenergic neuronal damage in rats with dilated cardiomyopathy.

UNLABELLED: Metaiodobenzylguanidine (MIBG) is a reliable marker for the detection of cardiac adrenergic neuronal damage in heart failure. The cardioprotective properties of carvedilol, a vasodilating beta-adrenoceptor-blocking agent, were studied in a rat model of dilated cardiomyopathy after autoimmune myocarditis. METHODS: Twenty-eight days after immunization, surviving rats (41/55, or 75%) were divided into 2 groups treated with carvedilol, 2 mg/kg/d (group C, n = 19), or vehicle alone (0.5% methylcellulose, group V, n = 22). After oral administration for 2 mo, heart weight, heart rate, left ventricular end-diastolic pressure (LVEDP), and myocardial fibrosis were measured and compared with those in untreated rats (group N, n = 19). Myocardial uptake of (125)I-MIBG (differential absorption ratio) in the left ventricle was measured by autoradiography at 10, 30, or 240 min after tracer injection. RESULTS: Four (18%) of 22 rats in group V died between days 28 and 84 after immunization. None of the rats in group C or N died. Heart weight, heart rate, LVEDP, and area of myocardial fibrosis in group C (1.14 +/- 0.04 g, 345 +/- 16 beats per minute, 7.6 +/- 1.5 mm Hg, and 12% +/- 1%) were significantly lower than those in group V (1.34 +/- 0.04 g, 389 +/- 10 beats per minute, 12.3 +/- 1.3 mm Hg, and 31% +/- 2%). Although the differential absorption ratio was lower at all time points in group V than in group N, uptake after treatment increased in group C, compared with group V, at 10 min (12.5 +/- 1.0 vs. 7.6 +/- 0.8, not significant), 30 min (10.1 +/- 1.1 vs. 6.3 +/- 0.9, not significant), and 240 min (6.5 +/- 0.5 vs. 2.5 +/- 0.2, P < 0.05). The late washout ratio from myocardial radioactivity between 30 and 240 min in group C was lower than that in group V (36% vs. 60%). CONCLUSION: These observations indicated that carvedilol has beneficial effects and protects cardiac adrenergic neurons in dilated cardiomyopathy.

3-Iodobenzylguanidine↗

PubMed2002

Myocardial sympathetic denervation, fatty acid metabolism, and left ventricular wall motion in vasospastic angina.

UNLABELLED: Although various noninvasive methods have been used to detect vasospasm, none of them are sensitive enough for patients with sporadic attacks. Because abnormal fatty acid metabolism and cardiac adrenergic neuronal damage are observed in ischemic myocardium, (123)I-15-(p-iodophenyl)-3-R,S-methyl pentadecanoic acid (BMIPP) and (123)I-metaiodobenzylguanidine (MIBG) have recently been proposed as useful tracers for detection of myocardial damage. This study investigated the relationships among the coronary vasospastic regions, abnormal left ventricular regional wall motion, fatty acid metabolism, and sympathetic nerve functions and their changes during treatment in patients with vasospastic angina. METHODS: We evaluated 50 patients with vasospastic angina (25 with clinically documented vasospasm [group A] and 25 with vasospasm induced by ergonovine provocation [group B]) and 25 control subjects who had chest pain but had normal coronary arteries without ergonovine provocation of spasm. Sixteen patients in group A were reevaluated 6 mo after medical treatment. The territorial regions of the vasospasm-induced coronary artery, wall motion determined by left ventriculography, and BMIPP and MIBG uptake were compared. RESULTS: Regions exhibiting a positive reaction to the ergonovine provocation were observed in the right coronary artery in 41 patients, the left anterior descending artery in 33, and the left circumflex artery in 21. Provocation occurred in multiple vessels in 29 patients (58%). Reduction of wall motion was observed in 19 patients (38%). Sensitivity and specificity for the identification of vasospastic angina were 86% (43/50 patients) and 88% (22/25 control subjects), respectively, for BMIPP scintigraphy and 100% (50/50 patients) and 56% (14/25 control subjects), respectively, for MIBG scintigraphy. In the region exhibiting a reduction in left ventricular wall motion, BMIPP or MIBG uptake was decreased. The sensitivity and specificity of determination of vasospasm-induced coronary arteries were 71% (67/95 arteries) and 95% (71/75 arteries), respectively, for BMIPP scintigraphy and 96% (91/95 arteries) and 55% (41/75 arteries), respectively, for MIBG scintigraphy. After 6 mo, during treatment, vasospasm was reinduced by ergonovine provocation in 6 patients (group I) and was not reinduced in 10 patients (group II). Improvements of decreased BMIPP and MIBG uptake were lower in group I (25% +/- 4% and 16% +/- 4%, respectively) than in group II (69% +/- 4% and 50% +/- 3%, respectively; both P < 0.01). The regions in which vasospasm was reinduced exhibited decreased BMIPP and MIBG uptake. CONCLUSION: Abnormal fatty acid metabolism and cardiac sympathetic denervation were observed more frequently than were wall motion abnormalities in the vasospastic region in patients with vasospastic angina. BMIPP and MIBG scintigraphy are highly accurate and noninvasive techniques for determining the presence and location of vasospasm.

3-Iodobenzylguanidine↗