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Biomedical subjects

T Sobue

Publications and source records attributed to T Sobue.

At least 73 records · Page 4Linked to original sources
PubMed1994

Analysis of factors affecting uptake of Tc-99m Sn-N-pyridoxyl-5-methyltryptophan by hepatocellular carcinoma.

We performed Tc-99m PMT imaging in 176 patients with HCC and evaluated factors affecting 99mTc-PMT uptake by HCC with a logistic model. The probability of HCC showing increase in uptake of the radioisotope was 104.6 times higher in patients with the Ed I type than in those with the Ed III type and 12.1 times higher in patients with a tumor diameter of 5.0-7.9 cm than in those with a tumor diameter of 2.0-5.0 cm. Among the other variables, the serum AFP level and sex were suggested to have effects similar to those of the tumor size on Tc-99m PMT uptake by HCC. The grade of morphological differentiation of the tumor was therefore most markedly related to Tc-99m PMT uptake.

Age Factors↗
PubMed1994

Relation between ventriculoarterial coupling and myocardial energetics in patients with idiopathic dilated cardiomyopathy.

OBJECTIVES: The purpose of this study was to evaluate left ventricular contractility, arterial loading conditions and the way their interaction affects myocardial energetics. BACKGROUND: Ventriculoarterial coupling, defined as the ratio of effective arterial elastance to left ventricular end-systolic elastance, is known to reflect the mechanoenergetic performance of the heart. However, relations between the coupling and efficiencies of energy transfer from oxygen consumption to hydraulic energy have not been fully investigated in failing hearts. METHODS: Pressure-volume data were measured in 23 patients with idiopathic dilated cardiomyopathy by using a conductance catheter, and myocardial oxygen consumption was obtained simultaneously in 16 patients by a double-thermistor coronary sinus catheter. End-systolic elastance was determined by transient inferior cava occlusion. RESULTS: Data are reported as mean value +/- SE. Ventriculoarterial coupling at baseline was 3.24 +/- 0.28. It decreased from 3.12 +/- 0.43 to 1.86 +/- 0.15 (p < 0.05) for the group receiving dobutamine infusion and from 3.16 +/- 0.45 to 1.78 +/- 0.22 (p < 0.01) for the group receiving the oral phosphodiesterase inhibitor MS-857. The ratio of pressure-volume area to myocardial oxygen consumption had a positive correlation with ventriculoarterial coupling. The ratio of external work to pressure-volume area had a hyperbolic correlation with the coupling. The mechanical efficiency defined as the ratio of external work to myocardial oxygen consumption remained within a narrow range (16.4 +/- 1.2%). CONCLUSIONS: The degree of ventriculoarterial coupling is far from optimal and the cardiovascular performance is severely depressed mechanically and energetically in patients with idiopathic dilated cardiomyopathy. Although inotropic agents improve the coupling, they have a minimal effect on mechanical efficiency.

Cardiac Catheterization↗
PubMed1994

Case-control study for lung cancer and cigarette smoking in Osaka, Japan: comparison with the results from Western Europe.

In order to clarify the relation between cigarette smoking and lung cancer, a case-control study was conducted. The case series consisted of 1,376 lung cancer patients (1,082 males and 294 females) who were newly diagnosed and admitted to eight hospitals in Osaka during 1986-88. Smoking histories were compared with those of 2,230 controls (1,141 males and 1,089 females) admitted to the same hospitals during the same period without established smoking-related diseases. Odds ratios of current smoker versus nonsmoker were 18.1, 1.9, 21.4, and 3.8 for squamous, adeno, small, and large cell carcinoma, respectively, for males, and 9.7, 1.3, 12.1, 3.7, respectively, for females. Compared to the results from previous studies in Japan, the magnitude of the odds ratios for squamous and small cell carcinoma is approaching the level of Western Europe in the late 1970s. Population attributable risk of exsmokers has also been increasing to the level of Western Europe. Among male current smokers, smoking intensity, such as number of cigarettes per day or fraction smoked per cigarette, seemed to have a slightly greater influence on squamous cell carcinoma than adenocarcinoma, while factors associated with the spread of cigarette smoke, such as inhalation, seemed to have greater influence on adenocarcinoma. The difference in the distribution of these smoking characteristics between Japan and Western Europe could not fully explain the difference in lung cancer incidence and distribution of histologic types between the two areas.

Adenocarcinoma↗
PubMed1994

Hemodynamic parameters during dynamic exercise in patients with silent myocardial ischemia in the presence or absence of hypertrophy.

Hemodynamic parameters during supine leg exercise-induced myocardial ischemia were investigated in ten patients without left ventricular hypertrophy (group I), and in ten patients with left ventricular hypertrophy (group II). Both groups of patients had previously been diagnosed as having totally asymptomatic silent myocardial ischemia. Both groups were comparable in age, sex, left ventricular ejection fraction at rest, and extent of coronary artery disease. All of the patients exercised to the same extent without angina or its usual equivalent. Left ventricular filling pressure increased from 4 +/- 2 mmHg at rest to 11 +/- 3 mmHg at peak exercise in group I, and from 7 +/- 4 mmHg at rest to 19 +/- 7 mmHg at peak exercise in group II. Left ventricular filling pressure at peak exercise was significantly greater in group II than in group I (p < 0.01). Totally asymptomatic silent myocardial ischemia can be seen with either normal or mildly abnormal left ventricular filling dynamics during exercise. In addition patients with coexistent left ventricular hypertrophy can have severely abnormal left ventricular filling dynamics during exercise without ischemic cardiac pains. Therefore, severe ischemia and/or stretching of the ventricular wall may be necessary, but not sufficient, for the occurrence of chest pain.

Adult↗
PubMed1994

Evaluation of cancer prevention strategies by computerized simulation model: methodological issues.

A computerized simulation model developed to evaluate the potential impact of primary and secondary prevention is discussed from methodologic perspectives. In the simulation model, named CANSAVE (Cancer Strategy Analysis and Validation of Effect), the natural history of cancer was modeled as a Markovian stochastic process from cancer-free state to death. The lung cancer death rate among Japanese males was projected for 50 years to the year 2041. The simulation showed that the age-adjusted death rate would increase and reach a peak of 166 per 100,000 in 1989 and then decrease to 148 in 2003. It then shows a tendency to increase again, up to 255 in 2028. This change may be attributed to a lower smoking initiation rate among those born in the 1930s. Promotion of mass screening programs exhibits a more prompt effect than antismoking efforts, but the reduction in annual deaths is expected to be only 11%, even if a 100% participation is realized by the year 2000. The reduction in smoking initiation rate, on the other hand, begins to show a visible effect very slowly. It was predicted that a 1% annual reduction in smoking initiation rate would result in a 20% decrease in the number of deaths in 2041. The smoking cessation program is in the middle with regard to promptness. The predicted reductions in lung cancer deaths in 2041 were 13, 47, and 66%, respectively, when the annual smoking cessation rate was increased from 0.46% (present status) to 1, 3, and 5%. The combined application of all three preventive measures seems essential to realize the most effective reduction in lung cancer deaths.

Adult↗
PubMed1994

Hemodynamic effects of the calcium channel blocker pranidipine on exercise-induced angina.

Hemodynamic effects of a newly developed calcium channel blocker, pranidipine, on dynamic exercise-induced angina were investigated. Ten patients with stable effort angina pectoris underwent symptom-limited bicycle ergometer exercise testings before and after a single oral administration of pranidipine, and effects of pranidipine on systemic, cardiac and coronary hemo-dynamics induced by dynamic exercise were evaluated invasively. Pranidipine administration reduced systemic vascular resistance (from 1,764 +/- 109 to 1,115 +/- 60 dynes.sec/cm5; p < 0.01 at test, and from 1,120 +/- 102 to 795 +/- 62 dynes.sec/cm5; p < 0.05 at peak exercise) and mean arterial pressure (from 93 +/- 5 to 76 +/- 3 mmHg; p < 0.01 at test, and from 85 +/- 7 to 72 +/- 6 mmHg; p < 0.05 at peak exercise) with the increase in heart rate and cardiac index throughout exercise. Pranidipine also decreased coronary vascular resistance from 1.29 +/- 0.21 to 0.89 +/- 0.17 mmHg/ml/min (p < 0.05) at resting condition. At peak exercise, rate-pressure product and myocardial oxygen consumption decreased (from 237 +/- 21 to 215 +/- 18 x 10(2); p < 0.05, and from 31.3 +/- 7.5 to 21.7 +/- 3.9 ml/min; p < 0.05, respectively), while coronary vascular resistance did not change significantly. Furthermore, pranidipine mitigated ST-segment depression and elevation of pulmonary artery wedge pressure at peak exercise (from 0.20 +/- 0.03 to 0.13 +/- 0.02 mV; p < 0.01, and from 25 +/- 3 to 11 +/- 2 mmHg; p < 0.01, respectively). These results suggest that the major therapeutic effects of pranidipine for dynamic exercise-induced angina would be to reduce myocardial oxygen demand by improving peripheral circulation and reducing preload and afterload.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

[Trends of lung cancer incidence and its prognosis in Osaka, Japan].

Lung cancer incidence figures in Japan were estimated as 30,000 for males and 11,000 for females for 1989 and represented the second and the fifth leading site of cancer, respectively, according to the Research Group for Population-based Cancer Registration in Japan. It is also estimated that lung cancer will steadily increase in the future. In relative frequencies of the major histological types, squamous cell carcinoma showed a decreasing trend, while small as well as large cell carcinomas showed an increasing trend in Osaka. In the distribution of clinical staging, the proportion of localized cases accounted for only 20% of the lung cancers in 1990. Five-year relative survival rates for lung cancer were 11.3% for all patients and 43.0% for localized cases in Osaka in 1984-1986. The rates were reported as 13.5% and 36.6% for total patients and localized cases, respectively, among caucasians from the SEER Program, a NCI project including 10 population-based cancer registries in the US. No noticeable difference was observed between Japan and the US. To control lung cancer in Japan it is considered vitally important and urgent to develop (1) new examination methods for diagnosing lung cancer in the earlier stage, (2) an efficient and effective cessation campaign for cigarettes smoking and (3) non-smoking based education.

Carcinoma, Squamous Cell↗
PubMed1993

Effect of antianginal agents on the relationship between rate-pressure product and myocardial oxygen uptake.

To evaluate the effects of antianginal agents on the correlation between rate-pressure product and myocardial oxygen uptake, multistage supine leg exercise tests were performed by 21 patients with stable effort-induced angina pectoris before and after administration of antianginal drugs (a calcium channel blocker of the dihydropyridine class [10 mg of nisoldipine orally] in 11 patients and a beta-blocker [0.2 mg/kg of propranolol intravenously] in 10 patients). The rate-pressure product was closely correlated with myocardial oxygen uptake before and after administration of each drug. However, the slope of the regression line of rate-pressure product (X) and myocardial oxygen uptake (Y) became significantly steeper after the calcium channel blocker administration, and the Y-intercept was significantly increased by administration of the beta-blocker. Myocardial oxygen uptake was increased after administration of the calcium channel blocker and the beta-blocker compared with control values at corresponding rate-pressure product. These observations should be considered when the rate-pressure product is used to predict myocardial oxygen uptake in patients with angina pectoris who are receiving antianginal drugs.

Adult↗
PubMed1993

Hemodynamic mechanisms of the antianginal action of a novel vasodilator FK409 in dynamic exercise-induced angina.

FK409 is a novel vasodilator with a unique chemical structure. We wished to elucidate the mechanisms of antianginal action of FK409 in dynamic exercise-induced angina. Twelve patients with stable effort angina pectoris were studied before and after a single 40-mg oral dose of FK409. Chest pain was induced in all of 12 patients during the control multistage bicycle ergometer exercise. After FK409 administration, the same workload did not induce chest pain in 6 patients. The ST segment at peak exercise showed less severe depression from 0.15 +/- 0.02 to 0.05 +/- 0.01 mV (p < 0.001). Left ventricular (LV) filling estimated by the Doppler method was reduced, and pulmonary artery wedge pressure decreased significantly (p < 0.001) throughout exercise testing after FK409. Myocardial oxygen uptake and coronary sinus flow throughout exercise testing decreased significantly (p < 0.05) after FK409 administration. The results of the present study demonstrate that decrease in myocardial oxygen demand may be caused by pre- and afterload reduction and that it could be a major mechanism of the antianginal action of FK409. However, other mechanisms such as redistribution of coronary blood flow to the subendocardium, direct dilatation of the stenotic parts of the epicardial arteries, and an increase in collateral blood flow should be considered additional possible mechanisms of the antianginal action of FK409.

Aged↗
PubMed1993

Lung cancer incidence rate for male ex-smokers according to age at cessation of smoking.

Lung cancer incidence rate after the cessation of smoking was assessed for male ex-smokers according to the age at cessation, using the results from a case-control study for ex-smoker versus continuing smoker, and the lung cancer incidence rate function for continuing smoker estimated from Japan Vital Statistics and the "Six-prefectural Cohort Study" in Japan. This hospital-based case-control study consisted of 776 lung cancer cases (553 current smokers and 223 ex-smokers) and 772 controls (490 current smokers and 282 ex-smokers) who started smoking at ages 18-22. The odds ratio of developing lung cancer for ex-smokers compared to continuing smokers according to years since the cessation of smoking was estimated for four age groups (55-64, 60-69, 65-74 and 70-79). Given that the number of years since cessation of smoking is the same, reduction of the odds ratio appeared to be greater for the younger age group than for the older age group, reflecting the shorter period of exposure for the younger age group. Lung cancer incidence rate (per 100,000) was assumed to be expressed by the following function; 1.7 x 10(-5) x (age -24.3) for continuing smokers and 0.15 x 10(-5) x (age) for nonsmokers. Lung cancer incidence rate among ex-smokers according to years since cessation was then estimated to be the above function multiplied by the odds ratio from the case-control study for each age group. In contrast to the greater reduction of the odds ratio among younger ex-smokers, reduction of the incidence rate, in terms of rate difference, was considerably greater for older ex-smokers due to a high incidence rate of lung cancer for older continuing smokers. This indicates that the absolute magnitude of reduction of the lung cancer incidence rate after cessation of smoking is greater for older ex-smokers, although the relative magnitude of reduction is greater for younger ex-smokers.

Age Factors↗
PubMed1993

Abnormal postexercise systolic blood pressure response is a good indicator of impaired left ventricular filling during supine cycle ergometer exercise in patients with coronary artery disease.

To determine whether the postexercise systolic blood pressure (SBP) response is a useful marker of left ventricular filling abnormalities, supine leg exercise testing was conducted in 14 control subjects and 70 patients with coronary artery disease (CAD). An abnormal postexercise SBP response (the ratio of SBP after 3 min of recovery to the peak exercise SBP) was defined as 0.85 or more, which represented the cutoff point with the highest sensitivity and specificity for prediction of pulmonary artery wedge pressure (PAWP) of at least 20 mmHg at peak exercise in CAD patients. There was a significant difference between the SBP ratios of the two groups (Control, 0.72 +/- 0.05; CAD, 0.86 +/- 0.13; p < 0.01). There was no significant difference between the PAWP of the two groups at rest, but the PAWP at peak exercise was significantly higher in the CAD group (20.2 +/- 8.9 mmHg) than in the control group (11.5 +/- 4.0 mmHg)(p < 0.01). PAWP at peak exercise was > or = 20 mmHg in 35 (50%) of the 70 CAD subjects. The SBP ratio was significantly correlated with PAWP at peak exercise (r = 0.67, p < 0.01) in the CAD group, but not in the control group. An SBP ratio of > or = 0.85 showed a sensitivity of 80% and a specificity of 80% for predicting a peak exercise PAWP of > or = 20 mmHg in CAD patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Survival for clinical stage I lung cancer not surgically treated. Comparison between screen-detected and symptom-detected cases. The Japanese Lung Cancer Screening Research Group.

To assess the extent of overdiagnosis bias in lung cancer screening, clinical Stage I lung cancer cases detected by chest radiograph examination, with histologic or cytologic evidence of malignancy and not treated by surgical operation, were followed up for more than 10 years. Of 1297 screen-detected and 1297 symptom-detected cases collected from 20 institutions, 42 screen-detected and 27 symptom-detected cases satisfied the study criteria. In about half of the cases, the patients had no contraindication for surgical treatment, but they refused surgical procedure. All such patients from the screen-detected and symptom-detected groups died within 122 and 67 months, respectively, of diagnosis. Among the screen-detected and symptom-detected cases, 80% and 81%, respectively, of the patients died of lung cancer. The median survival time was 25 and 13 months for those in the screen-detected and symptom-detected groups, respectively. The difference in survival was statistically significant between the two groups, which indicated the effect of lead time and length-biased sampling. Analysis of the causes of death other than lung cancer showed that there was no difference in the observed cumulative rates of deaths of other causes between the two groups, and these figures were almost the same as those expected from the general population. This indicates that overdiagnosis bias would be minimal in screen-detected lung cancer cases detected by chest radiograph examination.

Aged↗
PubMed1992

A case-control study for evaluating lung-cancer screening in Japan. Japanese Lung-Cancer-Screening Research Group.

In order to evaluate the efficacy of lung-cancer screening, a case-control study was conducted using the data from 50 areas where population-based lung-cancer screening programmes have been operated by local municipalities. In most areas, chest X-ray examinations for all participants and sputum cytology for high-risk participants were offered annually. Case series consisted of 273 deceased lung-cancer cases. For each case, 2 to 5 controls (a total of 1,269 controls) were collected from those who were alive at the time of diagnosis of the corresponding case, matched by sex, age, smoking status and type of health insurance. Cases and controls were limited to a high-risk group for males and a non-high-risk group for females. Screening histories, which were obtained from the list of screenees, were compared between case and matched controls for the identical calendar period before the time of diagnosis of the case. The odds ratio of dying from lung cancer for those screened within 12 months vs. those not screened was 0.72 (95% confidence interval 0.50-1.03; p = 0.07). The odds ratio increased towards unity, as the length of time in which screening histories were compared increased. After adjusting for some other variables, which appeared to be associated with the opportunities of chest X-ray examination, the estimated odds ratio did not change. These results suggest some benefits from lung-cancer screening in terms of reduction of lung-cancer mortality and should be subject to further research.

Adult↗
PubMed1992

A 50-year projection of lung cancer deaths among Japanese males and potential impact evaluation of anti-smoking measures and screening using a computerized simulation model.

The lung cancer death rate among Japanese males was projected for 50 years to the year 2041 by a computerized simulation model. Long-term effects of anti-smoking measures and mass screening on lung cancer deaths were also evaluated. The simulation showed that the age-adjusted lung cancer death rate would increase and reach a peak of 166 per 100,000 in 1989 and then decrease to 148 per 100,000 in 2003. It then shows an increasing tendency again, up to 255 per 100,000 in 2028. The smoking initiation rates estimated from the observed lung cancer death rates showed that the changes in death rates may be attributed to a lower smoking initiation rate among those born in the 1930's. Promotion of mass screening programs is effective more quickly than anti-smoking measures but the reduction in annual cancer deaths is expected to be only 11%, even if 100% participation is achieved by the year 2000. A reduction in smoking initiation rate, on the other hand, affects lung cancer deaths very slowly. It was predicted that a 1% annual reduction in smoking initiation rate would result in a 20% decrease in the number of lung cancer deaths in 2041. A smoking cessation program is intermediate with regard to promptness. The predicted reductions in lung cancer deaths in 2041 were 13%, 47%, and 66%, respectively, when the annual smoking cessation rate was increased from 0.46% (present status) to 1%, 3%, and 5%. In conclusion, the combined application of all three preventive measures seems essential to realize the most effective reduction in lung cancer deaths.

Age Factors↗
PubMed1992

Efficacy of lung cancer screening; comparison of results from a case-control study and a survival analysis. The Japanese Lung Cancer Screening Research Group.

A case-control study to evaluate the efficacy of lung cancer screening conducted by us showed that lung cancer screening may reduce the mortality of the disease up to 28%. Assuming this efficacy is unbiased, and that the screening rate is 51.6%, which was observed in the control group in the above study, the number of lung cancer deaths prevented by screening in the study period was calculated to be 47 for males and females combined. In the same study population, screen-detected lung cancer patients (N = 207) in the same study period were followed and the 7-year survival rate (46.9%) was compared to the 5-year survival rate (11.3%) obtained by the Osaka Cancer Registry, in which screen-detected lung cancer patients were only 1.8%. The number of lung cancer deaths prevented by screening, estimated by the difference in the above two survival rates, was 74 (95% confidence interval; 55-93). The number of lung cancer deaths prevented by screening estimated from the case-control study was significantly lower than that estimated from the survival analysis. This indicates that the efficacy of lung cancer screening estimated by the case-control study was within the range that could be explained by the actual long-term survivors among the screen-detected patients in the study population.

Adult↗
PubMed1992

Cancer mortality survey in a spa area (Misasa, Japan) with a high radon background.

The 1952-88 cancer mortality records for inhabitants of the Misasa spa area, Japan, which has a high radon background, and a neighboring control area without any radon spa were analyzed (average outdoor Rn concentration: 26 mBq.liter-1 in Misasa vs. 11 mBq.liter-1 in the control area). Standardized mortality ratios (SMRs) for cancers of all sites were significantly lower among the inhabitants of both Misasa (male 0.538; female 0.463) and the control area (male 0.850; female 0.770), than in the whole Japanese population. Poisson regression analysis showed that the relative risks among the inhabitants of Misasa were significantly lower than in the control area for deaths from cancers of all sites (0.67) and stomach cancer (0.59). The relative risk of lung cancer death was also lower (0.55 times) in Misasa than in the control area, although the difference was not statistically significant. These results suggest that the linear no-threshold hypothesis for radiation risk may not be valid for exposure to low doses of radon.

Adolescent↗