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Biomedical subjects

R Hayashi

Publications and source records attributed to R Hayashi.

At least 271 records · Page 15Linked to original sources
PubMed1984

Alteration of hepatic lipidperoxide levels during cataract formation caused by glucocorticoids in developing chick embryos.

The level of hepatic lipidperoxides in chick embryos was determined during cataract formation resulting from glucocorticoid treatment. When 15 day old chick embryos were administered 0.25 mumol of hydrocortisone acetate their hepatic lipidperoxide level, determined by thio-barbituric acid, increased after a lag time of 20 hr and reached approximately 8-fold of control at 48 hr after the treatment. These studies indicate that the peroxidation of lipid in tissues should be considered in elucidating mechanisms of action or adverse effects of glucocorticoids.

Animals↗
PubMed1984

Digestion of protein substrates by subtilisin: immobilization changes the pattern of products.

Subtilisin BPN' (Bacillus protease strain N') was immobilized on glass-bead carriers of controlled pore size by the glutaraldehyde method. The Vmax and Km values of the synthetic substrate were similar for immobilized and free enzymes. However, the hydrolytic patterns of immobilized and free enzymes toward casein and carboxymethylated lysozyme were different. The free enzyme rapidly hydrolyzed the substrate in the early stage of the reaction to produce peptides of various sizes. The immobilized enzyme, however, slowly digested the casein and lysozyme during digestion; even in the late stage of digestion the original substrates were present in the reaction mixture. The peptide size produced by immobilized enzyme depended on the pore size of the carrier; enzyme immobilized on glass of smaller pore size produced smaller peptide products. These phenomena found with our system of immobilized protease and a protein substrate can be explained by a multiple attack mechanism, in which the substrate that has been forced to enter the matrix is attacked many times by the protease to be completely hydrolyzed, because the substrate and the intermediate-sized product are trapped inside the matrix under reduced diffusion movement. To explain the effective digestion that forms amino acids, we have proposed that a multiple type of attack is responsible for the intracellular protein degradation that takes place in cellular organelles in which hydrolytic enzymes are entrapped.

Caseins↗
PubMed1984

Effect of MPG on glucocorticoid-induced cataract formation in developing chick embryo.

Cataract in the developing chick embryo can be easily produced by administration of high doses of glucocorticoid and the cataract is preceded by a decreased level of glutathione in the lens (Nishigori et al, Exp Eye Res 36:617, 1983). In an attempt to prevent cataract formation, various natural and synthetic sulfhydryl compounds, glutathione, cysteine, ergothioneine, penicillamine, cysteamine and N-(2-mercaptopropionyl)glycine, were applied to hydrocortisone-treated developing chick embryos. N-(2-mercaptopropionyl)glycine showed the most potent delaying activity against cataract formation and also lessened the decrease of glutathione level in the lens. However, except for cysteamine, the other compounds tested had little or no effect.

Amino Acids, Sulfur↗
PubMed1983

Postoperative adjuvant immunotherapy of gastric cancer with BCG-cell wall skeleton. 3- to 6-year follow up of a randomized clinical trial.

The clinical effectiveness of immunotherapy with the cell wall skeleton of Bacillus Calmette-Guérin was assessed in a study involving 140 consecutive patients with gastric cancer, who were gastrectomized at a single institution from January 1976 through December 1978. These patients were randomized by an envelope method after operation and divided into three treatment groups: 'control', 'chemotherapy', and 'chemotherapy plus immunotherapy with BCG-CWS.' Only two patients who died during surgery were excluded, and a survey of survival periods was made on the remaining 138 patients in January 1982. As a result, statistically significant differences in the survival rate curve were observed between the control and chemotherapy plus immunotherapy groups (P less than 0.01), and between the chemotherapy and chemotherapy plus immunotherapy groups (P less than 0.05). These results emphasize effectiveness of BCG-CWS as an adjuvant immunotherapeutic agent in gastrectomized cancer patients.

Adult↗
PubMed1983

Effects of probucol on homozygous cases of familial hypercholesterolemia.

A marked reduction of serum cholesterol was obtained by treatment with probucol in heterozygous as well as in homozygous cases of familial hypercholesterolemia. A strict dietary regimen (low-fat, low-calories) intensified the hypocholesterolemic effect of the drug. The drug was also useful in diminishing the rebound of serum cholesterol after plasma exchange. Probucol reduced serum triglycerides in heterozygous cases of familial hypercholesterolemia, but there was a slight increase in triglycerides in homozygous cases. Treatment with probucol resulted in the regression of cutaneous and tendon xanthomas. Although it caused a decrease in HDL, it seems to be very effective in the treatment of familial hypercholesterolemia.

Adolescent↗
PubMed1983

Randomly controlled study of chemotherapy versus chemoimmunotherapy in postoperative gastric cancer patients.

From September 1979 through March 1981, a total of 302 patients with gastric cancer and undergoing gastrectomy at the Department of Surgery at Chiba University Hospital and its 14 affiliated hospitals was studied for clinical effectiveness of immunotherapy with Nocardia rubra cell wall skeleton. The patients were stratified by gross stage of cancer and degree of operative curability. They were then assigned randomly to either chemotherapy group or chemotherapy plus immunotherapy group. Immunotherapy used was intradermal injection of 400 micrograms of N. rubra cell wall skeleton which was given weekly for the first month and monthly thereafter. After the specimen was examined microscopically, the patients were classified by histological stage of cancer and radicality of surgical intervention into curative or noncurative groups. The patients were surveyed for survival period in December 1981. The postoperative survival rate was compared in patients of histologically curative or noncurative resection cases between the two treatment groups. No statistical difference was detected between the groups in age, sex, or operative procedures that might influence the patient's survival. As a result, statistical intergroup difference in survival rates was not seen in patients of the curative group, probably due to a short observation period. However, the intergroup difference in survival rates was statistically significant in patients of the noncurative group (p less than 0.01). These results indicate the adjunctive effect of N. rubra cell wall skeleton as an immunotherapeutic agent in patients undergoing gastrectomy for gastric cancer.

Adult↗