PubMed Health⌕ Search

Biomedical subjects

O Inoue

Publications and source records attributed to O Inoue.

At least 37 records · Page 2Linked to original sources
PubMed1991

Age-related changes in human D1 dopamine receptors measured by positron emission tomography.

The effects of age on the binding parameters of 11C-SCH23390, the highly selective ligand for central D1 dopamine receptors, at specific binding sites in the brain were studied. Seventeen healthy male volunteers (20-72 years old) participated. Regional radioactivity in the brain was followed for 40 min by positron emission tomography (PET). A high accumulation of radioactivity was observed in the striatum and there was a conspicuous accumulation in the neocortex. A two-compartment model was used to obtain quantitative estimates of rate constants of association (K3) and dissociation (k4). The binding potential (k3/k4) of the dopamine D1 receptors in the striatum and frontal cortex decreased by 35% and 39%, respectively, with age. The value of k3 decreased by 58% in the striatum and 83% in the frontal cortex, whereas the value of k4 decreased by 35% in the striatum and 72% in the frontal cortex with age.

Adult↗
PubMed1991

Swim stress alters in vivo binding of [3H]N-methylspiperone.

The effect of swim stress on the in vivo binding of [3H]N-methylspiperone in the striatum of the mouse was investigated. Mice were forced to swim for 5 min at 18 degrees C and the time course of radioactivity in the striatum and cerebellum, following intravenous injection of [3H]N-methylspiperone was measured. The ratio of radioactivity in the striatum to that in the cerebellum was plotted as a function of time for the estimation of in vivo binding to dopamine D2 receptors. Immediately after the swim stress, a significant decrease in binding to D2 receptors in vivo was observed. Neither the KD nor Bmax determined by in vitro binding were altered by swim stress. The time course of the changes in binding, within a 24 hr period, following the swim stress was also studied and a rapid reversal of binding, within 1 hr after the swim stress was observed. In vivo binding of [3H]N-methylspiperone in the cerebral cortex, which appeared to involve serotonin receptors, as well as D2 receptors, was not significantly altered by the swim stress. A saturation study of in vivo binding indicated that the decreases in binding to D2 receptors, due to swim stress, were primarily caused by changes in the apparent affinity rather than in the number of binding sites available in vivo. These results support the hypothesis that micro-environmental factors, including the diffusion barrier to the synapse, might be altered by swim stress.

Animals↗
PubMed1991

Quantitative in vivo analysis of benzodiazepine binding sites in the human brain using positron emission tomography.

Central-type benzodiazepine binding sites were characterized in a single normal human subject, using positron emission tomography (PET) and the radiolabelled benzodiazepine antagonist, carbon-11 labelled flumazenil ([11C] Ro 15-1788). The subject was scanned using tracer alone and tracer plus 4 different concentrations of unlabelled Ro 15-1788, including one concentration of unlabelled Ro 15-1788, chosen to produce maximum displacement of [11C] Ro 15-1788 from specific binding sites. Concentrations of free, unmetabolized [11C] Ro 15-1788 in plasma were estimated using a simple extraction and ultrafiltration method. Radioactivity in the regional exchangeable pool in brain was estimated under non-saturation conditions from the ratio of radioactivity in brain to plasma, under saturation conditions and the kinetics of free ligand in plasma. The specific binding was, then, estimated by the difference between the total radioactivity in brain and exchangeable pool radioactivity. Scatchard analyses were performed to yield Bmax and Kd values under pseudo-equilibrium conditions, which was observed as an increase of specific binding/free with reduction in specific binding. In cerebral cortex and cerebellum, the Bmax values were about 62-73 nmol/l and the Kd values were 3.6-6 nM in the estimation of free ligand in plasma and 12-15 nM in the estimation of exchangeable pool in brain, as free in brain.

Adult↗
PubMed1991

Intracoronary urokinase in Kawasaki disease: treatment and prevention of myocardial infarction.

The main cause of death in Kawasaki disease is myocardial infarction due to thrombotic occlusion of a coronary aneurysm. Intracoronary thrombolytic treatment was performed in 15 patients with Kawasaki disease with giant coronary aneurysms. Three patients had acute myocardial infarction, four demonstrated silent myocardial infarction, three suffered chest pain and five did not show ischemia features but had massive thrombus in the coronary aneurysms. Urokinase was infused into the coronary aneurysms as a bolus of 8,000 to 10,000 units/kg via a catheter over 10 minutes. Partial but significant coronary recanalization was achieved after injection of urokinase in a patient with acute myocardial infarction. Complete resolution of massive intracoronary thrombi was observed in 3 of 15 patents, and partial resolution was recognized in 4 cases. In 7 patients, the size of thrombus did not change. Recurrence of the thrombus was observed in 4 patients by serial two-dimensional echocardiography. Urokinase was readministered and two showed significant reduction in the thrombus. All patients have been followed for more than 2 years with longest 8 years (mean: 3.3 yrs), and none have had a recurrence of myocardial infarction or died. These findings suggest that intracoronary urokinase is useful for the treatment and prevention of myocardial infarction in Kawasaki disease.

Child↗
PubMed1991

Prevalence of hepatitis B virus infection markers among factory workers in Beijing, China.

Nearly 1,000 serum samples were obtained from apparently healthy workers of both sexes in various factories in Beijing during 1988-1989 and were examined for hepatitis B virus infection markers by radioimmunoassay. The overall prevalence (all ages and both sexes combined) of cases positive for HBsAg, anti-HBs and anti-HBc were 3.7%, 36.6% and 37.7%, respectively and the rate of those negative to any of the three markers studied was 56.1%. The infection rate was lower than the values reported early in the 1980s for Beijing populations or the values for populations in other parts of China.

Adolescent↗
PubMed1991

Hepatitis B virus prevalence in industrialized cities in China.

The prevalence of HBV infection was investigated by radioimmunoassay for HBsAg, anti-HBs and anti-HBc in over 1000 workers in large scale factories located in four industrial cities (Jinxi, Shanghai, Wuxi and Xian) in 1987 to 1990. The age dependency of the prevalence was not evident. The overall prevalence rate of those positive for any of the three markers was 62.6%. The rate was significantly (p < 0.01) higher than the rates found in Beijing in a previous study but lower than the values observed in earlier studies.

Adolescent↗
PubMed1991

Roles of sulfhydryl compounds in the gastric mucosal protection of the herb drugs composing oren-gedoku-to (a traditional herbal medicine).

We investigated the involvement of sulfhydryl compounds in the cytoprotective effect of each component herb drug composing Oren-gedoku-to (OGT) against ethanol-induced gastric lesions and potential difference (PD) reduction in comparison with that of OGT in rats. Pretreatment with N-ethylmaleimide (NEM) significantly blocked the cytoprotective effects of OGT, Coptidis rhizoma and Phellodendri cortex, but did not block the cytoprotective effects of Gardeniae fructus and Scutellariae radix. The inhibitory effects of OGT, Coptidis rhizoma and Phellodendri cortex against the PD reduction disappeared in the presence of NEM or diethyldithiocarbamate (DDC), whereas NEM or DDC had little or no effect with Gardeniae fructus and Scutellariae radix. These results suggest that the gastric mucosal protection of Coptidis rhizoma and Phellodendri cortex may be ascribed to the reinforcement of mucosal barrier resistance through endogenous sulfhydryl compounds and DDC-sensitive compounds, but those of Gardeniae fructus and Scutellariae radix may be independent of NEM- or DDC-sensitive compounds.

Animals↗
PubMed1991

Subjective symptom increase among dry-cleaning workers exposed to tetrachloroethylene vapor.

Subjective symptoms, hematology, serum biochemistry and other clinical signs were investigated in 56 dry-cleaning workers exposed to tetrachloroethylene at 20 ppm (as a geometric mean of 8-hr time-weighted average), and the results were compared with the findings in 69 non-exposed controls from the same factories. There were exposure-related increases in the prevalence of subjective symptoms during the work as well as in the past 3 month period, whereas there was no significant changes in hematology. Effects of the exposure on liver and kidney functions were also negative as judged by emission enzyme activities, BUN and creatinine in the serum.

Adolescent↗
PubMed1991

[Effect of aging on in vivo binding of 11C-N-methylspiperone in living human frontal cortex].

Reduced in vivo binding of 11C-N-methylspiperone (NMSP) with age in the living human frontal cortex was demonstrated, with positron emission tomography (PET). Eleven normal male volunteers (22 to 72 years old) were assessed. The uptake of 11C-NMSP in the frontal cortex peaked 7-15 min after intravenous injection, and then gradually decreased until the end of this study. On the other hand in the cerebellum, the uptake of 11C-NMSP peaked 10 min and rapidly declined. We analyzed the data using a three compartment model and determined rate constants k3 and k4. And the binding potential of receptors was estimated as the ratio of k3 (association rate constant) to k4 (dissociation rate constant) value. The k3 and k4 values were calculated from nonlinear regression, given by the set of parameter values that minimized the deviation between the measured kinetics and model prediction. As an input function, we used the radioactivity in the cerebellum. A significant reduction in BP with age was observed. Though both k3 and k4 values were decreased with age, this decrease of BP was found to be mainly due to the reduced k3 values. These results indicated that numbers of binding sites (Bmax) of serotonin S2 receptors in frontal cortex might be decreased with age.

Adult↗
PubMed1991

[Percutaneous balloon valvuloplasty for congenital aortic valve stenosis].

We performed percutaneous balloon aortic valvuloplasty for 10 patients with congenital aortic valve stenosis aged from 2 to 17 years and a 54-day-old infant with critical stenosis. The retrograde single balloon technique was used for 6 patients including the infant; the retrograde double balloon technique was used for 3 patients; and both techniques for 2 patients. The valvuloplasty was effective for 10 patients except for the infant in terms of the peak systolic pressure gradient between the left ventricle and aorta (from 80.6 +/- 21.9 to 29.4 +/- 17.0 mmHg). Follow-up cardiac catheterizations one year after valvuloplasty in 3 patients and 3 years after valvuloplasty in one patient disclosed no re-stenosis. Aortic regurgitation newly developed in one patient and advanced Sellers' classification I in 3 patients, however, all of them were asymptomatic and did not progress further. In the infant with critical stenosis, sufficient dilatation could not be achieved and acute myocardial infarction mainly at the lateral wall of the left ventricle developed during the valvuloplasty. He died 3 days after the valvuloplasty. The double balloon technique was found to be superior to the single balloon technique with the latter being ineffective in 2 cases, because the fixation of the balloon at the annulus was very difficult. Double balloon technique has low risk of vascular trauma and is applicable to a large sized annulus, because it enables blood supply between the 2 balloons during the inflation period.

Adolescent↗