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Biomedical subjects

K Uchida

Publications and source records attributed to K Uchida.

At least 1,333 records · Page 74Linked to original sources
PubMed1985

Ultrastructural distribution of peroxidase in thrombocytes of mammals and submammals.

The localization and distribution of peroxidase (PPO) activity were studied ultracytochemically in thrombocytes from lampreys, carps, frogs, snakes, tortoises, rabbits, sheep, dogs, and monkeys. PPO activity was not detectable in the thrombocytes of lampreys, carps, frogs, and snakes. However, this enzyme activity was demonstrated in the nuclear envelope and endoplasmic reticulum of tortoise thrombocytes. Dog and monkey thrombocytes (blood platelets) exhibited PPO activity in the dense tubular system, but this enzyme activity was not detectable in rabbit and sheep thrombocytes. Our observations are interpreted to suggest that thrombocytes from animals lower than amphibia are peroxidase negative. Furthermore, it can be said that thrombocytes from animals higher than reptiles are generally positive, although there are exceptions. PPO activity was localized in the endoplasmic-reticulum system, but not in the cytoplasmic granules of thrombocytes common to submammals and mammals. In this study, we also compared the distribution of peroxidase activity in thrombocytes, neutrophils, and eosinophils and conclude that these are significant differences in the distribution of PPO and myeloperoxidase.

Animals↗
PubMed1985

Auto-oxidative damage in cement dermatitis.

Oxygen intermediates (OIs) generated by stimulated polymorphonuclear leukocytes (PMNs) are known to induce auto-oxidative tissue damage at the site of inflammation. PMNs from five patients with severe and chronic cement dermatitis generated markedly increased levels of OIs. However, only a slight increase in OI generation by PMNs was observed in cement workers without cement dermatitis. Dapsone, which has recently been shown to decrease OI levels, was found to be clinically effective in the treatment of cement dermatitis in these five patients. After treatment, a significant decrease in OI generation was observed in all patients studied. In skin tissues from the cement workers without cement dermatitis, enhanced superoxide-dismutase (SOD) activities as well as increased OI generation by PMNs were noted. In spite of the greatly increased OI generation by PMNs, the SOD activities in the patients were comparable to those in healthy controls. These findings suggest that the severe skin manifestations in patients with cement dermatitis can partly be explained by a defective capacity for enhancing SOD activity which removes increased PMN-derived OIs and thus prevents subsequent tissue injury by OIs at the site of inflammation.

Adult↗
PubMed1985

Cyclosporin A effective therapy for fifty-two cadaver kidney recipients.

Fifty-two consecutive patients receiving cadaveric renal transplants were prescribed cyclosporin A and steroid therapy. Three of the recipients underwent re-transplantation and two of the patients were grafted with kidneys shipped from the United States. One year actuarial patient and graft survival rate with no exclusions were 94.2 percent and 81.6 percent, respectively, this rate being significantly better than results in case of the conventional combination of azathioprine, steroid and antilymphocyte globulin. The role of HLA-DR matching on cyclosporin A treatment was studied. One year actuarial graft survival rates of two HLA-DR matched and one HLA-DR matched were 91.7 percent and 78.9 percent, respectively. To assess the effects of cyclosporin A in the management of patients with acute tubular necrosis, the patients were divided into two groups, in terms of whether or not hemodialysis treatment was required for acute tubular necrosis. Although in the present protocol, cyclosporin A administration was begun before the operation, no significant differences in the graft survivals were evident between the two groups. Nephrotoxicity, hepatotoxicity and other side-effects of cyclosporin A could usually be dealt with by dosage adjustments, making feasible the chronic ingestion of this agent. The exceptional effectiveness and safety of cyclosporin A were evident throughout these early trials.

Adolescent↗
PubMed1985

Heterogeneity of muscarinic receptors in the guinea pig esophageal muscularis mucosae and ileal longitudinal muscle.

Pharmacologic characteristics of muscarinic receptors in the muscularis mucosae of the guinea pig esophagus were examined in vitro and compared with those of the longitudinal muscle of the guinea pig ileum. All cholinomimetics tested produced a sustained contraction of the muscularis mucosae, in a concentration-dependent manner, which was associated with a small biphasic change in membrane potential, initially a hyperpolarization followed by a depolarization. The contractile response was hardly modified by verapamil, but was depressed by calcium removal from the bathing medium. Both atropine and pirenzepine antagonized the contractile response in a competitive manner, with higher pA2 values than those in the ileum. These results indicate that the muscarinic receptors of the muscularis mucosae of the guinea pig esophagus mainly link with calcium ion channels which are independent of changes in membrane potential and that their subtype populations are probably pharmacologically distinct from those in the ileal longitudinal muscle.

Animals↗
PubMed1985

Effects of hyperprolactinemia on activities of 17-hydroxylase, 17 beta-ol-dehydrogenase and 5 alpha-reductase in neonatally grafted and host testes in mice.

Male and female (WB X C57BL/6)F1 hybrid mice were used. Two pituitaries from 60-80-day-old female mice were grafted under the capsule of the left kidney of 60-80-day-old male mice. One week after grafting, 2 testes from neonatal mice were grafted under the capsule of the right kidney of the grafted mice and 70-90-day-old intact male mice. The grafted and host testes, in groups of 10-26, were removed 15, 30, 40, 60 and 120 days after transplantation of the neonatal testes. Testicular homogenates were incubated with [3H]progesterone or [14C]4-androstene-3,17-dione, and enzyme activities per g tissue were estimated. Significantly elevated prolactin levels, slightly lower LH levels and normal testosterone levels were found in the mice with pituitary grafts, compared with those in the mice without pituitary grafts. Activities of 17-hydroxylase and 17 beta-ol-dehydrogenase increased clearly with age in the grafted testes in the mice without pituitary grafts, though the increases were inhibited significantly by the pituitary grafts. However, the pituitary grafts had no significant effect on activities of 17-hydroxylase and 17 beta-ol-dehydrogenase in the host testes under similar gonadotrophic stimulation. 5 alpha-Reductase activities in the grafted and host testes were unaffected by the pituitary grafts. These results show that hyperprolactinemia may directly inhibit increases in activities of 17-hydroxylase and 17 beta-ol-dehydrogenase with testicular age in neonatally grafted testes in mice.

17-Hydroxysteroid Dehydrogenases↗
PubMed1985

Inhibitory effect of organic solvents on the mutagenicity of N-nitrosodialkylamines in Salmonella.

The influence of organic solvents on the mutagenicity of 11 N-nitrosamines was examined in Salmonella typhimurium TA100 using the Ames's liquid incubation assay in the presence of rat-liver S9. The mutagenic activities of N-nitrosodimethylamine, N-nitrosodiethylamine, 6 oxidative derivatives of N-nitrosopropylamine and N-nitroso-2,6-dimethylmorpholine were considerably decreased by addition of dimethyl sulfoxide, dimethyl formamide, acetone, 95% ethanol or acetonitrile, which are recommended for use as solvents in the assay by Ames's group, to the incubation mixture. The mutagenic activities of N-nitrosodipropylamine and N-nitrosodibutylamine, which are barely soluble in water, were also suppressed by increasing concentrations of dimethyl sulfoxide. These organic solvents did not appear to exert their influence by desmutagenic and antimutagenic actions. In contrast, the recoveries of unmetabolized carcinogens from preincubation mixtures and from agar plates were significantly higher in the presence of organic solvents than in their absence. The results indicate that the inhibitory effect is a result of interference with the process of metabolic activation by liver S9.

Animals↗
PubMed1985

Aging changes of riboflavin concentration and glutathione reductase activity in erythrocytes.

Aged erythrocytes obtained by fractionation using gradient centrifugation with Dextran 40, showed lower glutathione reductase activity and riboflavin content than young cells. However, both young and old cells displayed almost the same increase in enzyme activity upon addition of flavin adenine dinucleotide to the test hemolysate in vitro. The lipid peroxide content in the cell membranes showed no consistent changes with aging.

Centrifugation, Density Gradient↗
PubMed1985

Usefulness of scintigraphic imaging using 131iodine-metaiodobenzylguanidine in localization of asymptomatic pheochromocytoma.

Localization of either multiple, metastatic and/or asymptomatic pheochromocytomas sometimes is elusive because all imaging methods to date have been nonspecific in character. We report 2 cases in which scintigraphy was used with a new radiopharmaceutical agent, 131iodine-metaiodobenzylguanidine, for the accurate localization of pheochromocytoma. To the best of our knowledge, this is the first report of asymptomatic pheochromocytoma imaged by 131iodine-metaiodobenzylguanidine scintigraphy.

3-Iodobenzylguanidine↗
PubMed1985

Contents of myofibrillar proteins in cardiac, skeletal, and smooth muscles.

The in situ contents of myosin, actin, alpha-actinin, tropomyosin, troponin, desmin were estimated in dog cardiac, rabbit skeletal, and chicken smooth muscles. Whole muscle tissues were dissolved with 8 M guanidine hydrochloride and subjected to two-dimensional gel electrophoresis, which is a nonequilibrium pH gradient electrophoresis (Murakami, U. & Uchida, K. (1984) J. Biochem. 95, 1577-1584) with some modification. The amount of protein in a spot on a slab gel was determined by quantification of the extracted dye. Dye binding capacity of individual myofibrillar proteins was determined by using the purified protein. Myosin contents were 82 +/- 7 pmol/mg wet weight in cardiac muscle, 105 +/- 10 pmol/mg wet weight in skeletal muscle, and 45 +/- 4 pmol/mg wet weight in smooth muscle. Actin contents were 339 +/- 15 pmol/mg wet weight in cardiac muscle, 625 +/- 27 pmol/mg wet weight in skeletal muscle, and 742 +/- 13 pmol/mg wet weight in smooth muscle. The subunit stoichiometry of myosin in the three types of muscles was two heavy chains and four light chains, and there was one light chain 2 for every heavy chain. The molar ratio of actin to tropomyosin was 7/1 in the three types of muscles. Striking differences were seen in the molar ratio of myosin to actin: 1.0/4.1 in cardiac muscle, 1.0/6.0 in skeletal muscle, and 1.0/16.5 in smooth muscle.

Actinin↗
PubMed1985

Relationship of glucose intolerance and indocyanine green clearance to respiratory enzyme levels in human cirrhotic liver.

The relationship of glucose intolerance and indocyanine green clearance to respiratory enzyme levels in liver mitochondria was studied along with standard liver function tests in 40 patients (8 cirrhosis, 19 cirrhosis with hepatoma, 13 non-cirrhotic with hepatoma). There was a negative correlation between cytochrome a(+a3) concentrations and phosphorylative activity per unit of cytochrome a(+a3) (r = -0.75, p less than 0.01), but no correlation between ICG-K and cytochrome a(+a3) concentrations. Cytochrome a(+a3) concentrations in cirrhotic patients with linear oral glucose tolerance pattern, characterized with no return toward normal glucose levels within 120 minutes after an oral glucose load, increased to 1.45 +/- 0.11 (10(-10) mol/mg of protein) compared with 0.90 +/- 0.07 in cirrhotic patients with parabolic OGTT pattern, characterized with a return toward normal glucose levels within 120 minutes (p less than 0.01) (0.82 +/- 0.02 in control patients without liver diseases). The former had high operative mortality regardless of ICG-K value and the latter had virtually uneventful clinical courses. It was suggested that increased cytochrome a(+a3) concentrations and impaired glucose tolerance might be responsible for decreased hepatic functional reserve and poor prognosis in cirrhotics.

ATP Synthetase Complexes↗
PubMed1985

Biliary excretion of latamoxef and N-methyltetrazolethiol in humans and rats.

The biliary excretions of latamoxef and N-methyltetrazolethiol (NMTT) were studied in patients with T-tubes inserted in their common bile ducts, and in bile fistulated male rats. The highest concentrations of latamoxef and NMTT in 6 patients with cholelithiasis were obtained 1-2 h after intravenous injection of a single 1-g dose, and the mean peak values were 66.2 and 0.85 microgram/ml, respectively. The values in patients with gallbladder carcinoma or pancreas head carcinoma were much lower than those with cholelithiasis. The biliary excretions of latamoxef and NMTT in rats were much higher and faster than in humans, with the highest levels being obtained within 30 min after injection. About 20% of the injected dose was recovered as latamoxef and 4% as decomposed materials in 2.5 h after injection. Latamoxef was not decomposed in human or rat bile when kept at -20 degrees C for 4 weeks if the pH was adjusted to 6; some decomposition occurred (10-20%) if the pH was not adjusted.

Animals↗
PubMed1985

[Clinico-pathological studies on small obese mice occurring in C57BL/6J-ob/ob mice].

Eight small obese mice, 10 to 79 weeks of age, which occurred in C57BL/6J obese mice, were examined clinico-pathologically. These mice were characterized by small-sized obesity, and showed hyperglycemia without hyperinsulinemia and glucosuria without ketonurina throughout their life span. Morphologically, neither hypertrophy nor hyperplasia were found in the islets of Langerhans. There were an increase of A cells and a decrease of B cells in their islets. In the kidney, thickening of mesangial matrix in glomeruli and deposition of glycogen in the nucleus of epithelial cells of the distal tubules were seen. These findings suggest that the small obese mice are an obese-diabetic animal of different type from the usual obese mice (C57BL/6J-ob/ob). The mechanism for development of this condition was unknown.

Animals↗
PubMed1985

[Pulmonary calcification in C3H mice].

C3H mice including aged retired breeding females, aged virginal females, young virginal females and young males were examined for the incidence and severity of pulmonary calcification. Pulmonary calcification appeared in aged females, but not in young mice of either sex, and the lesions in aged breeders were more severe and frequent than in aged virgins. These results indicate that spontaneous pulmonary calcification is observed in aged females of the C3H strain. The findings of increased incidence and severity of pulmonary lesions in aged breeders suggest that pregnancy, delivery and lactation are important enhancing factors. Calcified lesions were also observed in kidney, heart, brain, ovary, choroid plexus, cornea and artery in the animals examined.

Aging↗
PubMed1985

Altered bile acid metabolism in nonobese, spontaneously diabetic (NOD) mice.

Cholesterol and bile acid metabolism was examined in nonobese, spontaneously diabetic (NOD) female mice before and after the development of diabetes. After the development of glucosuria, the plasma and liver cholesterol levels, gallbladder bile weight after 5-h fasting, biliary cholesterol, phospholipid and bile acid concentrations, the lithogenic index, the pool size of bile acids, and fecal sterol excretion markedly increased, but fecal bile acid excretion and fractional turnover rates for the cholic acid and chenodeoxycholic acid groups decreased. The distribution percentage of bile acids in the small intestine did not change, but it increased in the gallbladder and decreased in the large intestine. One striking finding was a change in the bile acid composition: increases were recorded in cholic and deoxycholic acids while decreases occurred in bile acids derived from chenodeoxycholic acid, such as beta-muricholic and ursodeoxycholic acids in the bile and alpha-muricholic, beta-muricholic, omega-muricholic, and hyodeoxycholic acids in the feces. Therefore, the cholic acid group/chenodeoxycholic acid group (CA/CDCA) ratio increased in the bile, feces, and small and large intestines after the development of diabetes. These changes were very similar to those observed in alloxan-treated mice, suggesting that the changes found in NOD mice are caused by insulin deficiency.

Animals↗