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Biomedical subjects

Y Urata

Publications and source records attributed to Y Urata.

At least 91 records · Page 5Linked to original sources
PubMed1986

Rapid and simple isolation procedure for three component enzymes of pig heart 2-oxoglutarate dehydrogenase complex.

A novel procedure was developed for rapid separation of the three component enzymes of pig heart 2-oxoglutarate dehydrogenase complex by high performance liquid chromatography on a gel filtration column. The complex was dissociated and separated into two fractions of the first dihydrolipoamide succinyltransferase and a second yellow fraction within 1 h by chromatography on a preparative TSK-GEL G4000SW column equilibrated with 0.05 M potassium phosphate buffer (pH 7.0) containing 0.7 M guanidine hydrochloride, 0.05% Triton X-100 and 2 mM dithiothreitol at 10 degrees C. The dihydrolipoamide succinyltransferase fraction was further purified by incubation with 0.5% sodium deoxycholate and subsequent ammonium sulfate fractionation. The other two component enzymes, 2-oxoglutarate dehydrogenase and lipoamide dehydrogenase were separated from the second yellow fraction by chromatography on a calcium phosphate gel-cellulose column. The TSK-GEL column permitted very rapid dissociation and separation of the three component enzymes accompanied by good preservation of their activities and high overall yields.

Acyltransferases↗
PubMed1986

[A resected case of collision tumor of hepatocellular carcinoma and primary liver rhabdomyosarcoma].

Primary liver sarcoma is rare and especially its coexistence with hepatocellular carcinoma is extremely rare. We have collected eight cases of their coexistence in the literatures. The patient was a 62-year-old male complaining of right hypochondralgia and general malaise for about one month. CT scanning revealed the liver tumor and right hepatic lobectomy was performed. The tumor was sized in 14 by 9 by 9 cm and composed of hepatocellular carcinoma and rhabdomyosarcoma, which were were collided. Apparent striations in the rhabdomyosarcoma cells was observed under light-microscope. Alphafetoprotein, of which serum level was extraordinarily high, was detected only in hepatocellular carcinoma by special stains. He discharged one month after operation. He was readmitted due to recurrence and received trans-arterial embolisation therapy and systemic chemotherapy. Though transient effect was obtained. He died forty-five days after operation. Autopsy revealed that recurrent liver tumors consisted of only hepatocellular carcinoma and that no other tumorous lesion was found in the other parts of the body. Rhabdomyosarcoma was proved to be primary tumor the liver.

Carcinoma, Hepatocellular↗
PubMed1986

[A case of coexisting primary malignant lymphoma and adenocarcinoma of the stomach].

Reports of the presence of two histologically different neoplasms in one organ are still unusual. We experienced a rare case of coexisting primary malignant lymphoma and adenocarcinoma of the stomach. A 66-year-old woman was admitted in April 1983 because of weight loss and epigastralgia. Several examinations including gallium scan, upper GI endoscopy, biopsy and touch cytology of the stomach, were performed, and she was diagnosed as having primary malignant lymphoma (noncleaved, large cell type) of the stomach. After the administration of 20 mg of vincristine, 6,000 mg of cyclophosphamide, 1,000 mg of prednisolone and 150 mg of Adriamycin, she improved to complete remission in August 1983. In February 1984, she received gastrectomy because of stenosis of the esophagogastric junction. Microscopic examination of the ulcerated lesion at esophagogastric junction revealed moderately differentiated tubular adenocarcinoma infiltrating to the subserosa. Despite chemotherapy, peritonitis carcinomatosa developed, and the patient died of cachexia in July 1984.

Adenocarcinoma↗
PubMed1985

Hormone-dependent changes of blood vessels in DMBA-induced rat mammary carcinoma and its regression studied by 3H-thymidine autoradiography.

Using DMBA-induced rat breast cancer, the changes in the histology and proliferative activity underlying the phenomenon of tumor regression by hormone therapy were studied by 3H-thymidine autoradiography. The control tumor was found to essentially consist of two histologically different areas, medullary (A area) and tubular or cystic (B area). The cancer cells in the A area were homogeneously proliferating with a cell cycle time of 51h, and among those in the B area, 65% were proliferating with a cell cycle time of 81h while 35% were non-proliferating. Among the various-kinds of hormone therapies, ovariectomy plus male sex hormone administration was most effective in inducing tumor regression. In the regressed tumor, the A area was greatly diminished due to central necrosis and replaced by cystic B area. In the remaining A area, the cell cycle time was lengthened to 97h, and that for the proliferating cells in the B area was as long as 118h. The most striking histological change after ovariectomy plus male sex hormone administration was the diffuse necrosis of the capillary endothelial cell within 24h, followed by hemorrhage, central necrosis in the A area (1W), and final stage of fibrosis (2W). The tumor administered with female sex hormone after ovariectomy showed a rebound growth from the regression, due to the initial reactivation of the endothelial cell proliferation and following stimulation of cancer cell mitotic activity. From these observations, it is concluded that the capillary endothelial cells in DMBA-induced rat breast cancer are estrogen dependent, and that the tumor regression induced by decreased estrogen-level is attributable to the massive necrosis from capillary insufficiency and anoxia.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1985

Computer analysis of sub-parameters of depurination and depolymerization rate constants in Feulgen DNA hydrolysis.

Feulgen DNA hydrolysis curves derived from cytofluorometry at various temperatures and HCl concentrations were computer analyzed with least squares fit to Bateman function. By comparing the depurination (k1) and depolymerization (k2) rate constants at different hydrolysis conditions, it was found that the two parameters of temperature and HCl concentration can be expressed as k = AN2 X exp (-B/T), where A and B are constants, N is the HCl concentrations, and T is the absolute temperature. From the analysis of Feulgen hydrolysis curves with 2N HCl at various temperatures, it was calculated that A = 5.3590 X 10(14) and B = 12133.543, for k1, and A = 6.2401 X 10(14) and B = 12181.660, for k2 for mouse 4C hepatocytes fixed with absolute methanol. Computer generated theoretical hydrolysis curves using the above k1 and k2 values were compared with experimental curves at various temperatures and HCl-concentrations. The two types of hydrolysis curves coincided with each other when 1-3 N HCl was used at temperatures between 30-40 degrees C. The peak times of hydrolysis curves at different conditions determined by experimental analysis and theoretical estimations also coincided reasonably well with each other. The physico-chemical phenomena underlying the equation designating k1 and k2 values are discussed.

Animals↗
PubMed1984

Characterization of intermediate-molecular-weight acid phosphatase from bovine kidney cortex.

The distribution of acid phosphatases of intermediate molecular weight was determined in various mammalian tissues. The intermediate-molecular-weight acid phosphatases (designated P-II-1 and 2) comprised about 25% of the p-nitrophenyl phosphatase activity in the supernatant of bovine kidney cortex homogenate. The P-II-1 and 2 purified 2,000 fold showed the pI values of 5.9 and 5.7, respectively, on isoelectric focusing. Apparent molecular weights of both P-II-1 and 2 were estimated to be 42,000 by Sephadex G-100 gel filtration and 44,000 by SDS-polyacrylamide disc gel electrophoresis. Both the enzymes catalyzed the hydrolysis of a wide variety of natural phosphomonoesters, except for the phosphoproteins phosphoserine and o-phosphocholine. The enzymes showed a high activity on pyridoxal phosphate, beta-glycerophosphate, and 2'-AMP. The optimum activity pH was near 5 with p-nitrophenyl phosphate, but was shifted to the neutral range when pyridoxal phosphate was the substrate. The cations Hg2+ and Ag+ had a marked inhibitory effect. Neither enzyme was inhibited significantly by L-(+)-tartrate or pCMB. The two other types of acid phosphatases, the high-molecular-weight (designated P-I) and low-molecular-weight (designated P-III), were also purified to homogeneity from bovine kidney cortex, and were compared with P-II from several aspects including substrate specificity and susceptibility to various compounds.

Acid Phosphatase↗
PubMed1984

The presence of G1 and G2 populations in normal epithelium of rat urinary bladder.

The cell population kinetics of transitional epithelium of the rat urinary bladder was analysed by (3H) thymidine autoradiography and pararosanilin Feulgen DNA cytofluorometry. By flash and 72 h continuous DNA labelling, the generative cells of the transitional epithelium were found to be well localized in the basal layer, and it was postulated that che cells produced by cell proliferation in the basal layer would migrate towards the surface, maintaining direct attachment to the basement membrane by anchorage of a cellular process. Analyses of normal and wounded transitional epithelium revealed that 58.8% of all basal cells are G0 cells in G1 phase (G1-population), and 59.0% of the remaining basal cells reside in prolonged (75.1-108.0 h) G2 phase, preserving the ability to divide (G2-population). The cell cycle time of the generative basal cells including the long G2 phase was calculated as 129.1-162 h. All the cells existing in upper layers were found to be also G0 cells in G1 phase, with the DNA amounts of 2C class. No polyploid cells could be detected except for 2C-2C binucleated cells in the superficial layer. The existence of a G2-population may serve for the urgent need of cell incrementation to repair cell loss as the cells in G2 phase can divide without the time-delay needed for DNA synthesis. The rat transitional epithelium, which is composed exclusively of proliferating and potentially proliferative cells, will have much greater capability to repair damage than stratified squamous epithelia.

Animals↗