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Biomedical subjects

Y Tsuchiya

Publications and source records attributed to Y Tsuchiya.

At least 325 records · Page 18Linked to original sources

Selective effect of fractions of a yeast extract (PCO) on normal and malignant cells.

The selective action of two fractions of PCO (a yeast extract) on normal and malignant cells was demonstrated. In vivo, the mitotic activity of malignant cells was inhibited by the methanol-insoluble fraction of PCO, whereas the methanol-soluble fraction caused no inhibition. The in vitro studies, however, showed inhibition of mitoses with both fractions. The malignant cells employed in vitro and in vivo were the Krebs-2 and Ehrlich carcinomas. The nonneoplastic cells tested in vitro were established cultures of epithelial-like cells from murine bone marrow and thymus, and corneal epithelium and peripheral blood in vivo.

Animals↗

Congenital cystic dilatation of the common bile duct: relationship to anomalous pancreaticobiliary ductal union.

Thirty patients from 15 to 69 years of age with congenital cystic dilatation of the common bile duct were studied. The diagnosis was made by intravenous cholangiography in 70% of the patients and by percutaneous transhepatic cholangiography and/or endoscopic retrograde cholangiopancreatiography in the entire group. Cystic dilatation was also noted in the intraphepatic bile ducts in 12 patients. A union between the common bile and main pancreatic ducts occurred at a high position in 17 of 18 patients in whom both ducts were adequately opacified, forming an abnormally long common channel. One patient with choledochodele had a normal union. The anomalous unions were of two types: the pancreatic duct entering the common duct and the common duct entering the pancreatic duct. The mode of union was correlated with the degree of extrahepatic bile duct dilatation, age of onset, and frequency and severity of symptoms. It is postulated that the congenital anomaly in the union of the two duct systems is the cause of the disease and the congenital choledochocele has a different etiology.

Adolescent↗

Prevention of freeze denaturation of carp actomyosin by sodium glutamate.

1) Denaturation of carp actomyosin during storage at -20 degrees was studied with particular interest in the cryoprotective effect of sodium glutamate, the most cryoprotective of the compounds tested previously. 2) Storage with glutamate prevented the rapid decrease in solubility, viscosity, and ATPase (EC 3.6.1.3)activity of actomyosin during storage. Ultracentrifugal studies suggested that aggregation occurred in the frozen state without glutamate, but that added glutamate prevented aggregation or denaturation. 3) Electron microscopy showed that the original actomyosin consisted of long filaments with typical "arrowhead" structures, and that these decomposed into small fragments and sticked with globular portions, forming loosely packed aggregates during storage without glutamate. On storage with glutamate, the filaments were well preserved, and their fine structure was clearer than that of the original sample. 4) Preparations of actomyosin extracted with 10 mM glutamate were of better quality and their ultrastructure and physicochemical and biochemical properties showed increased stability on freezing. 5) Freeze-denaturation seems to involve complicated aggregation with transconformation of proteins besides the side-to-side aggregation discussed previously.

Actomyosin↗