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Biomedical subjects

H Yoshimura

Publications and source records attributed to H Yoshimura.

At least 559 records · Page 31Linked to original sources
PubMed1983

[Effects of chromium compounds on the respiratory system. 2. Difference between water-soluble hexavalent and trivalent compounds].

Transference and transformation of chromium compounds, known as occupational carcinogens, in the lung of rats were studied by determining blood chromium levels after a single mist inhalation or an intravenous injection of water-soluble chromic acid (hexavalent) and chromium chloride (trivalent). Conclusion drawn from this study are as follows: Transference of chromium from the lung to the blood stream is ended quickly after the inhalation of chromic acid mist. Alveolar permeability of hexavalent chromic acid is much higher than that of trivalent chromium chloride. The greater part of the transferred chromium in the blood after the inhalation of chromic acid mist is not transformed to any other form; therefore, it seems to be present as the hexavalent form. The hexavalent chromic acid in the blood diffused to the liver, kidneys and the spleen, but the trivalent chromium chloride distributed only in the blood. The hexavalent chromic acid in the blood decreased more slowly than the trivalent chromium chloride. The biological half-time of the chromic acid in the blood was about 60 hours, whereas that of the chromium chloride was only about 2 hours. These results suggest that the water-soluble hexavalent chromium compounds may be apparently different from the trivalent chromium compounds in the transference from the lung and following distribution in the body. These differences might be caused by the high permeability through the cell membrane in hexavalent chromium compounds and the high possibility of binding with proteins in trivalent chromium compounds.

Aerosols↗
PubMed1983

[Squamous change in gastric cancer].

Squamous change was found at the rate of 4% in 3,727 operated patients with gastric adenocarcinoma. The incidence of squamous change was 0.47%, 4.2% and 5.6% in the early, pm-invasive and s-invasive cases, respectively. This phenomenon was considered to be secondary metaplastic change associated with the growth of the adenocarcinoma. Protuded type cancers were found in 63.5%, well-differentiated adenocarcinoma with moderate to marked intestinal metaplasia was found in 86.1%. The average patient age was 65.5, the male to female ratio was 2.3:1. Regarding cancer location, 19.6% were in the upper 1/3 of the stomach, especially adjacent to the esophago-cardiac junction.

Adenocarcinoma↗
PubMed1983

[Pharmaco-ethological analysis of agonistic behavior between resident and intruder mice: effects of ethylalcohol].

The present study was conducted to investigate the effect of ethylalcohol on agonistic behavior using a resident-intruder paradigm. In this paradigm, a resident male mouse has been cohabiting with a female for 5 weeks, and an intruder male mouse is introduced into the resident's home cage. The effects of four doses of ethylalcohol (vehicle, 0.5, 1.0, and 2.0 g/kg, p.o.) were assessed in resident mice and group-housed intruder mice. Residents and intruders were drugged on alternate test days, and all animals received different sequences of drug conditions according to a random schedule. When resident mice were treated with ethylalcohol biphasic effects on resident's aggressive elements were observed: 0.5 and 1.0 g/kg of ethylalcohol increased attack bitings and sideways posture, while 2.0 g/kg of the drug suppressed aggressive elements. On the other hand, when intruder mice were drugged the resident's attack bitings were significantly increased in a dose-dependent manner. At this time, defensive upright postures of intruder mice were suppressed by the drug. Ethylalcohol at the employed doses did not affect locomotor activity in both resident and intruder mice. The results suggest that ethylalcohol enhances the hostility of resident to the intruding animal and suppresses the anxiety of an intruder to the attacking animal.

Aggression↗
PubMed1983

Anaplastic carcinomas in nude mice and in original donor strain rats inoculated with cultured oval cells.

Male Sprague-Dawley rats were fed for 4-5 weeks a choline-devoid diet containing 0.1% DL-ethionine. Preparations of nonparenchymal epithelial cells, enriched in oval cells, were isolated from the livers of these animals and were placed in culture. Six lines of hepatic epithelial cells were thus established. The lines underwent transformation after several passages, became tumorigenic in nude mice and 3 lines also in rats of the same strain of origin of the isolated cells. The tumors were uniformly highly anaplastic carcinomas. Preliminary morphologic, cytologic, and cytochemical results were consistent with the tumoral cells being hepatocytelike cells. These findings are viewed and discussed in terms of the cellular source, in vivo, of longterm cultures of rat liver epithelial cells, and in relation to a possible role of hepatic nonparenchymal epithelial cells in the process of hepatocellular tumor induction by chemical carcinogens.

Animals↗