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Biomedical subjects

M Kondo

Publications and source records attributed to M Kondo.

At least 1,045 records · Page 58Linked to original sources

Somatostatin suppresses plasma aldosterone concentration in a case of Bartter's syndrome.

The study was conducted to examine the effect of somatostatin on activated renin-angiotensin-aldosterone system in a case of Bartter's syndrome. After 60 minutes of 500 micrograms of somatostatin infusion, the plasma aldosterone concentration was reduced from the basal level of 250 pg/ml to 140 pg/ml, whereas plasma renin activity remained at the basal level. This result suggests that somatostatin may specifically inhibit aldosterone secretion in Bartter's syndrome and the agent can be applied to a treatment of this syndrome.

Adrenocorticotropic Hormone↗

Hyperinsulinemic yellow KK mice and norepinephrine turnover.

To clarify whether hyperinsulinemia accelerates sympathetic nervous system (SNS) activity, norepinephrine (NE) turnover, a reliable indicator of SNS activity, was measured in the interscapular brown adipose tissue (IBAT) and heart of hyperinsulinemic yellow KK and normoinsulinemic C57BL control mice at 12 weeks of age. The yellow KK mice were more obese and had higher levels of plasma glucose (about 2.3 times) and of plasma insulin (about 24 times) than did the control mice. In IBAT, the rate of NE turnover following blockade of NE synthesis with alpha-methyl-p-tyrosine (alpha-MPT) was significantly slower in yellow KK mice than in C57BL mice, although in heart, no significant difference between both groups was observed in NE turnover. These results suggest that hyperinsulinemia dose not always increase NE turnover, and furthermore that the reduced NE turnover in IBAT of yellow KK mice may be one of the important factors in the development of obesity of this animal, as it is recognized that brown adipose tissue is a main effector of diet-induced thermogenesis and its defect or absence would predispose to obesity.

Adipose Tissue, Brown↗

Effect of aldose reductase inhibitor ONO 2235 on reduced sympathetic nervous system activity and peripheral nerve disorders in STZ-induced diabetic rats.

To test the hypothesis that inhibitors of aldose reductase, a key enzyme for polyol synthesis, prevent the decrease of sympathetic nervous system (SNS) activity and improve motor nerve conduction velocity (MNCV) through the reduction of sorbitol accumulation in streptozocin (STZ)-induced diabetic rats, norepinephrine (NE) turnover (reliable indicator of SNS activity in the interscapular brown adipose tissue (IBAT), heart, and pancreas), and MNCV were measured in untreated STZ-induced diabetic rats, STZ-induced diabetic rats treated with an aldose reductase inhibitor (ARI) (ONO 2235, 50 mg X kg-1 X day-1, orally), STZ-induced diabetic rats treated with insulin therapy, control rats, and control rats treated with ARI. As expected, results from studies with the inhibition of NE biosynthesis with alpha-methyl-p-tyrosine or radiolabeled NE to measure NE turnover demonstrated significant reductions in SNS activity in IBAT, heart, and pancreas of untreated STZ-induced diabetic rats, compared with those in control rats. MNCV determined with the tail nerve was significantly reduced in untreated STZ-induced diabetic rats, compared with that of the controls. Both daily ARI treatment and insulin therapy in STZ-induced diabetic rats prevented partially but significantly the decrease of NE turnover in IBAT, heart, and pancreas, ameliorated MNCV, and reduced sorbitol accumulation in the nerve tissue and red blood cells. ARI treatment in control rats had no effect on NE turnover, MNCV, or sorbitol content. These results suggest that STZ-induced diabetic rats had not only motor neuropathy but also sympathetic nervous dysfunction and that ARI treatment might prevent these as well as insulin therapy does through the reduction of sorbitol accumulation.

Aldehyde Reductase↗

[Chemoembolization with degradable starch microspheres in malignant hepatic tumors].

A new method of chemoembolization with degradable starch microspheres (DSM) was used for patients with malignant hepatic tumors. DSM, 40-45 micron in diameter, which are degraded by serum amylase, temporarily obstruct arterial blood flow at the arteriolar capillary bed. Experimental studies have demonstrated that such occlusion enhances the regional uptake and reduces systemic exposure to simultaneously administered arterial anticancer drugs. Transcatheter chemoembolization with DSM was performed in 14 cases of hepatocellular carcinoma and 8 cases of metastatic liver cancer. Adriamycin or Mitomycin C mixed with DSM was injected into the patients with hepatocellular carcinoma or metastatic liver cancer, respectively, through the proper hepatic artery. The therapeutic effect of this chemoembolization was evaluated by the change in tumor size measured by angiography or computed tomography. In hepatocellular carcinoma, tumor regression of over 50% was observed in 5 of 14 patients. Elevated serum AFP level of more than 200 ng/ml was decreased in all 6 cases. In metastatic liver cancer, tumor regression of over 50% was observed in 4 of 8 cases. Although half of the patients had transient pain within 2 hours, no major side effects such as bone marrow suppression and hepatotoxicity were observed. Our results suggest that chemoembolization with DSM can be effectively used in the treatment of malignant hepatic tumors.

Carcinoma, Hepatocellular↗

Effects of L-threo-3,4-dihydroxyphenylserine on efflux of monoamines and acetylcholine in guinea pig brain.

The effect of L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS) on the release of monoamines and acetylcholine (ACh) was studied in the superfused brain slices of guinea pig. In the tissues preloaded either with [3H]norepinephrine ([3H]NE), [3H]dopamine ([3H]DA), [3H]-5-hydroxytryptamine or [3H]choline, tritium effluxes were estimated in serial fractions of superfusates. L-threo-DOPS produced a concentration-dependent increase in the spontaneous efflux of [3H]NE both in the cortical and hypothalamic slices and to a lesser extent that of [3H]DA in the striatal slices. These effects were still fully detected when slices were superfused with a calcium-free medium or tetrodotoxin (10(-6) M). Carbidopa at 5 X 10(-4) M but not at 10(-4) M significantly depressed the [3H]catecholamine effluxes induced by L-threo-DOPS. L-threo-DOPS produced a minimum increase in the spontaneous efflux of [3H]-5-hydroxytryptamine but not that of [3H]ACh. L-threo-DOPS (5 X 10(-4) M) significantly reduced the [3H]ACh efflux from electrically stimulated striatal slices and this effect was antagonized by an alpha-2 adrenoceptor antagonist yohimbine (10(-6) M) or by a D2 DA receptor antagonist sulpiride (10(-6) M). In vivo, L-threo-DOPS (150 mg/kg i.p.) produced a gradual but long-lasting increase in the efflux of [3H]NE from the parietal cortex of the guinea pig pretreated with carbidopa (20 mg/kg i.p.). In the brain homogenates, L-threo-DOPS (10(-10) to 10(-4) M) itself did not inhibit the bindings of [3H]rauwolscine or [3H]spiperone, specific ligands for labeling alpha-2 and D2 receptors, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗

[Cold constitution: analysis of the questionnaire].

"Hie-sho" means having a cold constitution. The authors studied basic data for cold constitution with a questionnaire and with the Cornell Medical Index. The subjects were 318 females, and the average age was 26.4 +/- 6.1 (Mean +/- SD) and the range was 20 approximately 51 years of age. The results were as follows: (1) 38.7% of the subjects had been conscious of having a cold constitution, and it was recognized that the subjects with a cold constitution are found not only in the climacterium but also in the young. (2) The average age of onset of cold constitution was 19.3 +/- 5.1 years old. (3) The parts of the body that usually felt cold were first the feet and then the hands. (4) In winter or at bedtime the cold sensation was increased. And it is characteristic that the sensation was changed by weather or by body condition, especially by the stimulation of coldness. (5) Most subjects with a cold constitution took care in their daily life, but very few of them were treated. (6) Many other physical symptoms were recognized in subjects with a cold constitution, and their CMI scores were high. Therefore these data may be regarded as indicating that most cases of cold constitution are a partial symptom of vegetative disturbance (autonomic nerve dysfunction). (7) Most of the mothers of subjects with a cold constitution also had a cold constitution, which suggests the involvement of a hereditary factor concerning in the development of a cold constitution.

Adult↗

Natural history of atrial fibrillation.

The clinical significance of atrial fibrillation was analyzed in cases with chronic or acute heart disease and its significance at the acute and chronic stages of the disease was investigated in various disease groups. The types of disease, number of patients, and incidence of atrial fibrillation were: atrial septal defect (92, 14.1%), mitral valve disease (128, 79.7%), nonrheumatic valvular disease (32, 56.2%), aortic regurgitation (71, 2.8%), aortic stenosis (10, 10.0%), hypertrophic cardiomyopathy (181, 11.6%), dilated cardiomyopathy (111, 37.8%), acute myocardial infarction (823, 9.0%), healthy subjects (31,886, 0.3%). A histopathological and electron-microscopic evaluation of the atrial heart muscle revealed that the advancement of the morphological changes was closely related to the occurrence of atrial fibrillation. Decrease in size of F waves in the electrocardiogram correlated well with the extent of right and left atrial fibrosis. Also, it was noteworthy that the atrial fibrillation in cases with dissecting aneurysm (n = 60) was an expression of the myocardial damage due to the infiltration of the bleeding into the right atrium. Intra-atrial electrogram in 48 patients with various heart diseases revealed that the electric potentials obtained from various parts of the atrium varied to a great extent and finally the patient's condition transformed to that of atrial standstill. We conclude that atrial fibrillation is an expression of some important aspect of the progression of heart disease and is not directly associated with hemodynamic overloading to the atrium. A strategy for quinidine treatment was also introduced.

Age Factors↗