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Biomedical subjects

T Shibagaki

Publications and source records attributed to T Shibagaki.

23 records · Page 2Linked to original sources
PubMed1988

The mechanism of carbon tetrachloride induced pulmonary Clara cell damage: biochemical and morphologic studies.

In our present study, we have shown the different damages among pulmonary drug metabolizing systems and selective lesions of the pulmonary Clara cells in mice treated with carbon tetrachloride. Concerning with the inhibition degrees of pulmonary drug metabolizing systems, the inhibition of coumarin hydroxylase activity was the severest in this experiment. Moreover, at the in vitro carbon tetrachloride exposure study to estimate carbon tetrachloride metabolizing capacity, the severe degradation of coumarin hydroxylase activity was observed, while 7-ethoxycoumarin o-deethylase and NADPH-cytochrome c reductase activities only showed slight degradations by carbon tetrachloride treatment. From these results, it is suggested that cytochrome P-450 form which catalyzes coumarin hydroxylation may highly localize in the Clara cell and have carbon tetrachloride metabolizing activity.

Animals↗
PubMed1987

Quantitative study of pulmonary endocrine cells in anencephaly.

Quantitative studies of pulmonary endocrine cells in 8 male autopsy cases of anencephaly were performed. The densities of pulmonary endocrine cells were expressed as the number of the total argyrophil cells/100 bronchiolar cell nuclei and as the number of the total argyrophil cells/mm bronchiole. The average values in the 8 anencephalic cases were 1.26 cells/100 nuclei and 3.56 cells/mm, and did not differ from the 1.28 cells/100 nuclei and 3.24 cells/mm in the control cases without malformation of the brain and without severe hyaline membrane disease of the lung. Furthermore, there was no significant difference in the densities of neuroepithelial bodies between the 2 groups. Immunostaining for calcitonin, bombesin, adrenocorticotropic hormone, chromogranin, and neuron-specific enolase also revealed no qualitative differences between them. It is concluded that defect and hypofunction of the hypothalamus-pituitary-adrenal axes associated with anencephaly do not have significant effects on the proliferation and differentiation of pulmonary endocrine cells in the fetus.

Anencephaly↗
PubMed1986

Fraction of pluripotent hemopoietic stem cells in DNA synthesis varies with generation age.

The fraction of pluripotent hemopoietic stem cell (CFU-S) in DNA synthesis (S phase) was evaluated for day 7 through 13-spleen colonies. The CFU-S in S phase in normal bone marrow decreased progressively, from 43% on day 7, to 23% on day 11, and 4% on day 13. The cycling fraction of 5-fluorouracil (5FU)-treated CFU-S was also evaluated. The S phase fraction for CFU-S surviving 5FU was 100.0, 58.8, 54.7, and 25.6% at day 7, 9, 11, and 13, respectively, and the proportion of the fraction also was not constant. The S phase fraction for CFU-S surviving 5FU was much higher than that for normal bone marrow cells; this might be attributed to the extensive regenerating ability of CFU-S surviving 5-FU. The results obtained suggest that a stem cell population in S-phase may exhibit a hierarchy based on the "generation-age hypothesis" (Rosendaal, Hodgson, and Bradley 1979) of the stem cell compartment.

Animals↗