Search PubMed⌕ Search

Biomedical subjects

Y Hashimoto

Publications and source records attributed to Y Hashimoto.

At least 1,621 records · Page 90Linked to original sources
PubMed1979

Keratinization of transformed epithelial cells of the rat urinary bladder: its quantification and effect of various drugs.

In vitro and in vivo transformed epithelial cells of the rat urinary bladder keratinized well on a coverslip culture. Keratinization proceeded more rapidly in in vitro-transformed cells than in in vivo-induced bladder cancer cells. The grade of keratinization was estimated from the absorption spectrum of a papanicolaou-stained specimen which afforded two peaks derived from keratinized cells and viable cells. Using this semiquantitative method, effect of various drugs on keratinization was studied on 3 lines of in vitro-transformed epithelial cells. Vitamin A and its analogs prevented the keratinization in 2 out of 3 lines at dosage over 1 micrograms/ml, but other drugs such as vitamin C, E, and K, steroid hormones, cyclic AMP, polyamines, polyanions, and dimethyl sulfoxide were ineffective for preventing keratinization. Amino acid compositions of keratinized cells and viable cells were not fundamentally different.

Amino Acids↗
PubMed1979

[Studies on biopharmacological actitivy of active vitamin D3 analogues (VII) Effect of 1 alpha-hydroxycholecalciferol on renal function in rats and Beagle dogs (author's transl].

In male Wistar rats, 1 alpha-HCC and 1 alpha, 25-DHCC induced diuretic effects in doses of 2.5 and 25 micrograms/kg p.o., while no such effects of 1 alpha-HCC were seen with a dose of 0.25 microgram/kg p.o. Effect of 1 alpha-HCC appeared later than that of 1 alpha, 25-DHCC, but at 24 hr, the difference disappeared. Similar results were obtained with urinary concentrations of calcium (increase) and phosphorus (decrease). Glomerular filtration rate (GFR) and tubular reabsorption of phosphate (TRP) were remarkably elevated by 1 alpha, 25-DHCC, and effects of 1 alpha-HCC were rather weak and apparently not dose dependent. In light of these results and the finding that there was no difference between the effects of 1 alpha-HCC and 1 alpha, 25-DHCC on serum calcium and phosphorus at 24 hr, the mechanism of action of these sterols on the renal function seems to differ. In male Beagle dogs, 0.25 microgram/kg/day p.o. of 1 alpha-HCC or 1 alpha, 25-DHCC induced a severe hypercalcemia and GFR was decreased in the 1 alpha, 25-DHCC treated group. A gradual recovery occurred with cessation of the administration. Thus decrease in GFR was considered to be due to calcification of the kidney.

Animals↗
PubMed1978

Changes in placental permeability to corticosterone and estradiol-17beta toward the end of gestation in the rat.

Radioactivity in the fetal plasma 1 h after maternal injection of 14C-4-corticosterone or 14C-4-estradiol-17 beta on day 21 of gestation was markedly higher than that 1 h after injection on day 22. Radioactivity in the maternal plasma was not different on these 2 days. The results suggest that the placental permeability to steroids from the mother to the fetus declines toward the end of gestation in the rat.

Animals↗
PubMed1978

Development of the fetal pituitary-testicular system based on the observation of Leydig cells in encephalectomized, hypophysectomized and control fetal rats.

The time of onset of brain regulation of the pituitary-Leydig cell system in fetal rats was assessed by fetal encephalectomy, which allowed the pituitary to persist in situ. The effects of encephalectomy were compared with those of fetal hypophysectomy (surgical decapitation). The parameter for interpretation of these effects was the collective volume of Leydig cells, measured by the method of Chalkley ('43). The normal increase in the collective volume of Leydig cells in fetuses encephalectomized on day 17 of gestation and autopsied on day 18 was not retarded, whereas that in decapitated fetuses of the same age was retarded. In all other one-day experimental periods (day 18-19, 19-20, 20-21, and 21-22), the increase in volume was retarded to approximately the same extent in encephalectomized as in decapitated fetuses. The collective volume of Leydig cells continued to increase to some extent without the brain until day 20, after which it ceased to increase. The results suggest that in fetal rats, the brain control of the pituitary-Leydig cell system begins to operate from day 18 of gestation, when the day following overnight mating was designated as day 1 of gestation.

Animals↗
PubMed1978

Prostaglandin I2 as a potentiator of acute inflammation in rats.

Prostaglandin I2 potentiated the paw swelling induced by carrageenin in rats. Prostaglandin I2 (0.1 microgram) showed similar activity to PGE1 (0.01 microgram). This potentiating property disappeared in 60 minutes and was completely abolished by diphenhydramine (25 mg kg-1, i.p.). In vascular permeability tests, PGI2 itself (2.5 X 10(-10) mol, 88 ng) caused no dye leakage reaction, but PGE1 (2.5 X 10(-10) mol, 88.5 ng) caused a significant dye leakage. This effect of PGE1 was statistically significant compared with vehicle- or PGI2-treated groups (p less than 0.05). Prostaglandin I2 potentiated the increased vascular permeability induced by 5-hydroxytriptamine (2.5 X 10(-10) mol), bradykinin (5 X 10(-10) mol) and histamine (2 X 10(-10) to 2 X 10(-8) mol). The potentiation was the most evident in the case of histamine.

Acute Disease↗
PubMed1978

Diazepines. 5. Synthesis and biological action of 6-phenyl-4H-pyrrolo[1,2-a][1,4]benzodiazepines.

A series of 6-phenyl-4H-pyrrolo[1,2-a][1,4]benzodiazepines (2) has been prepared with 2-phthalimidomethylfurans (12) and 1-phthalimidoalkane-2,5-diones (15) or 2,5-dimethoxy-2-phthalimidomethyltetrahydrofurans (16) as the key intermediates and subsequently evaluated for CNS activity. The structure-activity data generated indicate that, in general, introduction of the methyl and/or ethyl group(s) in the pyrrole ring and a chlorine atom at the ortho position of the 6-phenyl group increases the activity and that substitution of the above chlorine atom for a fluorine atom decreases the activity. 8-Chloro-6-(2-chlorophenyl)-1,3-dimethyl-4H-pyrrolo[,2-a][1,4]benzodiazepine (2p), the most potent among the compounds synthesized, was equipotent in taming and sedative activities to diazepam. The acute LD50 of 2p in mice was larger than 3000 mg/kg po.

Animals↗