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T Sagara

Publications and source records attributed to T Sagara.

At least 55 records · Page 3Linked to original sources
PubMed1987

Relative activities of thymidylate synthetase and thymidine kinase in 1,2-dimethylhydrazine-induced colon carcinomas in rats.

Thymidylate synthetase (TS) and thymidine kinase (TK) are known to catalyse the methylation of dUMP for the de novo synthesis of dTMP and the phosphorylation of thymidine for the salvage synthesis of dTMP in the pyrimidine pathway, respectively. High TS and TK activities and the existence of TK isozymes have been observed in rapidly proliferating tissues. TS and TK activities in 1,2-dimethylhydrazine (DMH)-induced colon carcinomas in rats increased significantly to 331 and 207% of the activities in normal colon, respectively, and were well correlated inversely (y = -0.93x + 5.24), with a correlation coefficient of -0.787. The colonic TK isozymes were separated into two types by DEAE-cellulose column chromatography. The TK isozyme eluted from the column by the elution buffer alone without NaCl was markedly higher (23.6-fold) in activity in DMH-induced colon carcinoma than in normal control colon and was not affected by deoxycytidine triphosphate. This isozyme, whose mol. wt is 100,000 by h.p.l.c., is thought to be closely involved in rapid DNA replication. These results indicate that early biochemical changes in DMH-induced colon carcinoma in rats may serve as a useful model and provide valuable insight into the mechanisms involved in colonic carcinogenesis.

1,2-Dimethylhydrazine↗
PubMed1987

Long-term prognosis of vasospastic angina without significant atherosclerotic coronary artery disease.

Long-term prognosis of 90 patients with vasospastic angina without significant coronary artery disease (less than 50% reduction in luminal diameter) was examined for a mean follow-up period of 4 years. All patients had episodes of angina at rest and were treated with calcium antagonists. One patient developed myocardial infarction and 2 died suddenly during the follow-up period. In the patient with myocardial infarction, there was an abrupt worsening of angina prior to the infarction despite therapy with a calcium antagonist. One of the sudden death patients discontinued his calcium antagonist before his death. Of the sudden death patients, one had ventricular tachycardia and the other had a complete atrioventricular block during an anginal attack. The incidence of such serious arrhythmias was higher (p less than 0.01) in sudden death patients (2/2) than that in survivors (6/88). The treatment with calcium antagonists reduced the severity and frequency of angina in all patients. These results suggest that long-term prognosis of vasospastic angina without significant coronary artery disease is good as characterized by the low incidence of myocardial infarction and death and the favorable response to treatment with calcium antagonists.

Adult↗
PubMed1986

Increased activities of thymidine kinase isozymes in human mammary tumours.

Thymidine kinase, the enzyme in the pyrimidine salvage pathway, and its isozymes were examined in 10 specimens of normal mammary gland, 10 fibroadenomas and 11 adenocarcinomas in human breasts. The average thymidine kinase activities in fibroadenomas and adenocarcinomas were about 3 and 8 times that in normal mammary gland. The mammary thymidine kinase isozymes were separated into two types by diethylaminoethyl (DEAE) cellulose column chromatography. The activity of the thymidine kinase isozyme eluted with 0.1 M sodium chloride in buffer was twofold higher in fibroadenomas and fourfold higher in adenocarcinomas than that in normal tissue. In adenocarcinomas, but not fibroadenomas, the activity of the other isozyme eluted with buffer alone was increased to 22-fold that in normal tissues. As the activity of the latter isozyme was not affected by deoxycytidine triphosphate, it may be involved closely in DNA replication.

Adenocarcinoma↗
PubMed1985

Increased activities of thymidine kinase isozymes in human colon polyp and carcinoma.

Thymidine kinase (TK), the enzyme in the pyrimidine salvage pathway, and its isozymes were examined in 15 specimens of normal mucosa, 14 polyps and 14 carcinomas in human colon. The average TK activities in colon polyps and carcinomas were about 1.6 and 2.9 times that in normal colon mucosa, respectively. The colon TK isozymes were separated into 2 types by DEAE-cellulose column chromatography. The activity of the TK isozyme eluted with 0.1 M NaCl in buffer was 1.6-fold higher in colon polyp and 1.5-fold higher in colon carcinoma than that in normal colon mucosa. In colon carcinoma, but not colon polyp, the activity of the other isozyme eluted with buffer alone was increased to 5.1-fold that in normal tissues. As the activity of the latter isozyme was not affected by deoxycytidine triphosphate, it may be involved in DNA replication. The results suggest that increases in the activities in the former and latter TK isozymes may indicate tumorigenesis and carcinogenesis, respectively, in the human colon.

Adult↗
PubMed1982

Prosthetic replacement of entire left hemidiaphragm in malignant fibrous histiocytoma of the diaphragm.

A case of primary malignant fibrous histiocytoma of the diaphragm which, to our knowledge, is the first record in the world literature, is presented. It occupied almost the entire left hemidiaphragm and was surgically removed with the left lower pulmonary lobe, stomach, colon, and spleen. The entire left hemidiaphragm then was replaced with Marlex mesh. Prosthetic replacement of the entire hemidiaphragm, which has not been previously reported, was successfully performed with preservation of pulmonary function on the affected side. The patient died of brain metastases of malignant fibrous histiocytoma more than 4 months postoperatively. Diagnosis of diaphragmatic tumors and a technique which involves the use of a prosthesis are discussed.

Brain Neoplasms↗