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Biomedical subjects

M Shibata

Publications and source records attributed to M Shibata.

At least 793 records · Page 44Linked to original sources
PubMed1980

New experimental congenital diabetic mice (N.S.Y. mice).

New experimental congenital diabetic mice were obtained in the descendants of streptozotocin-induced diabetic mice. Diabetes was developed by the administration of strepotozotocin in normal adult I.C.R. mice, and then these mice were mated to obtain the F1 mice. The F1 mice with impaired glucose tolerance were mated within the siblings. The same process was repeated over several generations. The diabetic features of the spontaneously diabetic mice thus obtained were as follows: 1) The mice did not show a tendency toward obesity. 2) Glucose tolerance of these mice, especially after the F6 generation, was remarkably impaired. However, the elevation of the fasting blood glucose level was slight throughout the generations. We propose to designate the congenital diabetic mice as the N.S.Y. (Nagoya, Shibata, Yasuda) mice. The N.S.Y. mice are considered to be useful models for human diabetes.

Animals↗
PubMed1980

A new antibiotic K-82 A and minor components, produced by Streptomyces lavendulae, strain No. K-82.

From the results of taxonomic studies, Streptomyces sp. strain No. K-82 isolated from a soil sample collected in Kumamoto city, was identified as a strain belonging to Streptomyces lavendulae WAKSMAN & HENRICI 1948. The strain produced an active new antibiotic called K-82 A and minor components named the B complex. Antibiotic K-82 A was isolated as dark reddish needles by silica gel column chromatography and found to have both antibacterial activity and high phage induction activity. The K-82 B complex was found to consist of at least five components, among which K-82 B2 and B3 were isolated as crystals. Substances K-82 B2 was identified as benzoic acid from its physicochemical properties. Substance B3 like B2 had only marginal antibiotic activity.

Anti-Bacterial Agents↗
PubMed1980

Dose response of saccharin in induction of urinary bladder hyperplasias in Fischer 344 rats pretreated with N-butyl-N-(4-hydroxybutyl)nitrosamine.

Studies were made on the dose response of saccharin in the induction of bladder lesions. Inbred F344 rats of both sexes were pretreated with 100 ppm N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in the drinking water for 4 weeks. Sodium saccharin was given at 50,000, 10,000, 2,000, and 400 ppm in the diet for 32 weeks after BBN administration, and surviving rats were killed at the end of week 36 of the experiment. No increase in incidence of papilloma or cancer was noted in either sex at any dose of saccharin after BBN as compared to levels induced by BBN alone. The incidences of two types of hyperplasia and average number of papillary or nodular hyperplasias per 10 cm of basement membrane were significantly increased in the group receiving 50,000 ppm saccharin as compared to the group given BBN only. None of the incidences or numbers of these lesions were significantly different in any of the other saccharin-treated groups when compared to the group treated with BBN alone except for the incidences of two types of hyperplasias in the female rats dosed with 10,000 ppm saccharin. Dose-response curves showed enhanced hyperplastic responses in both sexes given 2,000--50,000 ppm saccharin. Administration of various doses of saccharin without BBN did not cause any changes in the urinary bladders of rats of either sex. These results show that saccharin enhances the induction of early-stage bladder lesions and that the biologic response demonstrates a dose-response effect.

Animals↗