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Biomedical subjects

S Katoh

Publications and source records attributed to S Katoh.

At least 325 records · Page 18Linked to original sources
PubMed1986

[Clinical statistics on outpatients, inpatients and operations in 1984].

Statistical studies on 1,893 outpatients, 538 inpatients and 554 operative procedures at our department in 1984 revealed the following. The most frequent diseases among the outpatients were urogenital infections followed by anomalies, tumors and stones. The major diseases among the inpatients were hypospadias, vesicoureteral reflux, benign prostatic hypertrophy, bladder tumor and congenital urethral stenosis. A total of 554 operations were performed on 534 patients, and five major operations were hypospadias repair (68), ureterocystoneostomy (57), optic internal urethrotomy (50), TUR-P (42) and TUR-Bt (33).

Adolescent↗
PubMed1985

Carbonyl reductase activity of sepiapterin reductase from rat erythrocytes.

A homogeneous preparation of sepiapterin reductase, an enzyme involved in the biosynthesis of tetrahydrobiopterin, from rat erythrocytes was found to be responsible for the reduction with NADPH of various carbonyl compounds of non-pteridine derivatives including some vicinal dicarbonyl compounds which were reported in the previous paper (Katoh, S. and Sueoka, T. (1984) Biochem, Biophys. Res. Commun. 118, 859-866) in addition to the general substrate, sepiapterin (2-amino-4-hydroxy-6-lactoyl-7,8-dihydropteridine). The compounds sensitive as substrates of the enzyme were quinones, e.g., p-quinone and menadione; other vicinal dicarbonyls, e.g., methylglyoxal and phenylglyoxal; monoaldehydes, e.g., p-nitrobenzaldehyde; and monoketones, e.g., acetophenone, acetoin, propiophenone and benzylacetone. Rutin, dicoumarol, indomethacin, and ethacrynic acid inhibited the enzyme activity toward either a carbonyl compound of a non-pteridine derivative or sepiapterin as substrate. Sepiapterin reductase is quite similar to general aldo-keto reductases, especially to carbonyl reductase.

Alcohol Oxidoreductases↗
PubMed1985

Dyspropterin, an intermediate formed from dihydroneopterin triphosphate in the biosynthetic pathway of tetrahydrobiopterin.

The structure of dyspropterin, a new name given to an intermediate which is formed from dihydroneopterin triphosphate in the biosynthetic pathway of tetrahydrobiopterin, has been studied. Sepiapterin reductase (EC 1.1.1.153) was found to reduce dyspropterin to tetrahydrobiopterin in the presence of NADPH. Several lines of evidence showing the formation of tetrahydrobiopterin have been presented. Stoichiometric analysis revealed that there is a 1:2 relationship between the production of biopterin and the oxidation of NADPH during the reductase-catalyzed reduction of dyspropterin. The tetrahydrobiopterin production from dyspropterin was enhanced by dihydropteridine reductase (EC 1.6.99.7). Dyspropterin could also serve as a cofactor in phenylalanine hydroxylase (EC 1.14.16.1) system. These results are consistent with the view that dyspropterin is 6-(1,2-dioxopropyl)-5,6,7,8-tetrahydropterin. Based on our findings, the biosynthetic pathway of tetrahydrobiopterin from dihydroneopterin triphosphate has been discussed.

Alcohol Oxidoreductases↗
PubMed1985

The sulfhydryl groups of ferredoxin-NADP+ oxidoreductases: is a disulfide bond really present?

The sulfhydryl groups of three ferredoxin-NADP+ oxidoreductases [EC 1.18.1.2] (FNR) two from blue-green algae, Spirulina sp. and Synechococcus sp., respectively, and one from spinach, were analyzed by carboxymethylation and titration with sulfhydryl reagents under different conditions. Five sulfhydryl groups in Spirulina and spinach enzymes and four in Synechococcus enzyme were found to be in reduced forms. There was no disulfide bond in any FNR tested. The results in the present experiment contradict those reported by Karplus et al. [Biochemistry 23, 6576-6583 (1984)].

Amino Acids↗
PubMed1985

[A case report of a double cancer of the ureter and stomach].

A 63-year-old man complained of hunger epigastralgia. X-ray and endoscopic examination demonstrated Borrmann II type gastric carcinoma. Radical gastrectomy was performed on October 20, 1982. The histological findings revealed moderately differentiated tubular adenocarcinoma. In May 1983, right hydronephrosis was recognized by ultrasonography. A papillary tumor was visualized in the right ureter in retrograde pyelography, and percutaneous transrenal urinary tract drainage was performed. Cytological findings revealed class V. Total nephro-uretectomy was performed on June 16, 1983. The histological findings revealed transitional cell carcinoma.

Carcinoma, Intraductal, Noninfiltrating↗
PubMed1985

[Prognostic factors influencing the improvement of allogeneic bone marrow transplantation in acute leukemia based on a national survey in Japan].

The records of 115 patients with acute leukemia who underwent allogeneic bone marrow transplantation from 1975 through August 1984 were collected by a national survey in Japan. One-year survival significantly improved from 9% in group I (before 1980) to 52% in group II (after 1981). Multivariate analysis indicated that selection of the patients in remission without infection at the time of transplant, as well as progress in technology of total body irradiation and selection of a platelet donor with negative cytomegalovirus titer resulted in the significant improvement in survival after 1981.

Acute Disease↗
PubMed1984

Sepiapterin reductase exhibits a NADPH-dependent dicarbonyl reductase activity.

We have found a new ability of sepiapterin reductase, which has been known to show a strict substrate specificity for the 6-lactyl sidechain of sepiapterin to produce 6-dihydroxypropyl sidechain of dihydrobiopterin in the biosynthesis of tetrahydrobiopterin, to reduce many dicarbonyl compounds with NADPH as effectively utilized substrates. By analysis of diacetyl reduction by purified sepiapterin reductase, it was observed that both of the carbonyl groups of the compound are finally sequentially reduced by the enzyme with NADPH to hydroxyl groups. And we expect that this enzyme may reduce "Compound X", which is an intermediate of tetrahydrobiopterin synthesis and would be a dicarbonyl derivative of pteridine (Tanaka et. al., 1980), to dihydrobiopterin via sepiapterin.

Acetoin↗
PubMed1984

Statistical analysis of favorable prognostic factors in allogeneic bone marrow transplantation for acute leukemia in Japan.

By means of a national survey, records of 69 patients who underwent allogeneic bone marrow transplantation (BMT) from September 1975 through June 1983 were collected from 11 participating hospitals of the Total Body Irradiation (TBI) Subcommittee in Japan. The patients were divided into 34 with acute lymphocytic leukemia (ALL), and 35 with acute nonlymphocytic leukemia (ANLL). One-year survival rates were 47% and 25% in ALL and ANLL patients, respectively. Uninfected patients in remission at the time of BMT had significantly higher survival rates than the remaining patients. Significantly favorable prognostic factors were remission at the time of BMT, absence of infection at the time of BMT, younger age, preparation with low-dose-rate fractionated TBI and cyclophosphamide, and mild graft-versus-host disease (GVHD) for patients with acute leukemia treated with allogeneic BMT based on the external criterion variable of 180-day survival. By using Hayashi's quantification II, the ratios of correct discriminations for 180-day survival were calculated as 91% (31/34) and 86% (30/35) for ALL and ANLL, respectively.

Acute Disease↗