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Biomedical subjects

H Hoshi

Publications and source records attributed to H Hoshi.

At least 361 records · Page 20Linked to original sources
PubMed1981

Cortical structure of the lymph node. I. Effect of blockage of the afferent lymph flow to mouse popliteal nodes for protracted periods.

Changes in the lymphoid organization of the popliteal lymph nodes in mice, under conditions where the afferent lymph flow to the nodes was kept blocked for a protracted period, were the subject of this study. Surgical operations to interrupt the afferent lymphatics of the popliteal nodes were performed and the afferent lymph flow remained blocked for 15 weeks after the operation. A striking accumulation of small lymphocytes occurred within the nodes and the cellular density of the parenchyma and lumina of the sinuses greatly increased. These changes persisted throughout the 15 weeks period of observation. Germinal centres gradually diminished in size and ultimately disappeared completely from most of the operated nodes. Lymphatic nodules, which were aggregations of B lymphocytes, decreased in size to some extent but the number of these structures per whole node was not significantly different from that of the unoperated node. The deep cortex remained highly populated with small lymphocytes and showed no indication of fading out or of being replaced by the medullary structures.

Animals↗
PubMed1980

Pharmacokinetics of ketoprofen following single oral, intramuscular and rectal doses and after repeated oral administration.

The pharmacokinetics of ketoprofen was studied in the same healthy subjects after single oral, intramuscular and rectal doses, and after repeated oral administration. No significant difference in the mean t1/2 (1.13-1.27 h) was observed after the different modes of administration. The mean [AUC] 0 infinity after rectal administration of a suppository showed the minimum significant difference (p < 0.05) from that after oral administration of the capsule. The apparent volume of distribution (Vd/F) was approximately 10-15% of body weight. The renal contribution (mean, 0.10-0.15 ml/min/kg) to the plasma clearance of free ketoprofen was assumed to be, at most, 8.3-12.9%. The projected cumulative excretion of total (free plus conjugated) ketoprofen via urine exceeded 63-75% of the dose, of which approximately 90% was ketoprofen glucuronide. A mean of 71-96% and 73-93% of the oral capsule was estimated to be systemically available after administration of the intramuscular preparation and rectal suppository, respectively. In four of seven subjects, CPK concentration was elevated after the intramuscular injection. The mean steady-state concentration of ketoprofen in plasma ranged from 0.43 to 5.62 microgram/ml after the final dose of a 50 mg q. i. d. regimen. The disposition data and plasma levels observed at steady-state were in agreement with those predicted from the single oral dose study. The accumulation ratio was 1.08 +/- 0.08. The results suggest that the rectal suppository can be recommended as an extravascular mode of administration of this drug.

Administration, Oral↗
PubMed1978

Rabbit bone marrow after administration of saponin. An electron microscopic study.

Saponin rapidly induced injury to the wall of vascular sinuses in rabbit bone marrow so that the barrier between hematopoietic cells and the circulation became defective. This change was followed by hypocellularity and necrosis and fibrosis. Adult male rabbits received saponin intravenously (2 mg. per kg.) every 4 days for periods of up to 4 weeks; the animals were killed at varied times. In untreated animals, much of the sinus wall consisted only of endothelium. Within 2 hours after administration of saponin the endothelium was damaged and hematopoietic cells, mostly reticulocytes and normoblasts, entered the circulation. Some sinuses hemorrhaged into the hematopoietic compartment. At 4 hours, sinuses were markedly dilated and hemorrhage was extensive. By 3 days, extravasated erythrocytes, which were tending to aggregate, were unevenly distributed in the extravascular space of marrow. Damaged hematopoietic cells were dispersed among them. Regenerating blood vessels were noted and a few clusters of hematopoietic cells occurred in association with fibroblasts. At 1 week, a large portion of the marrow was either necrotic or contained large-scale diffuse or focal hemorrhage. Fibrotic areas often surrounded the arteries. After 2 to 4 weeks, myelofibrosis became pronounced. The fibrotic tissue was well vascularized and contained small clusters of hematopoietic cells and a few fat cells. Macrophages were abundant and tended to fuse, forming multinucleated giant cells surrounding pockets of degenerated fat cells.

Animals↗
PubMed1977

Repair of the sublethal and mutational damage induced by x-rays in Chinese hamster HAI cells in vitro.

The ability of Chinese hamster hai cells to repair damage related to cell death and mutational change induced by X-rays were examined by using a sensitive forward mutation system from prototrophic CH-hai Cl 23 cells to auxotrophs. The results obtained from the split dose experiments seem to suggest that Chinese hamster hai cells have the repair mechanisms for the sublethal and mutational damage induced by X-rays and that the repair mechanisms act in common for the repair of both cases of damage.

Cell Line↗
PubMed1977

Preventive effect of selenium, methionine and antioxidants against encephalomalacia of chicks induced by dilauryl succinate.

The protective effect of supplemental selenium, methionine, ascorbic acid, menaquinone and five antioxidants against encephalomalacia of chicks fed a diet containing dilauryl succinate was examined. Diauryl succinate induces vitamin E deficiency signs such as fragility of the erythrocytes and encephalomalacia. Supplementation of selenium and methionine with or without simultaneous supplementation of a low level of dl-alpha-tocopheryl acetate had little effect on preventing encephalomalacia. The preventive effect of ascorbic acid, methylene blue, ethoyquine, 2,6-ditertiary-butyl-p-cresol and butylated hydroxyanisole was roughly in proportion to their dietary level, and a high level of any of them could almost completely protect the chicks from encephalomalacia, while diphenyl-p-phenylenediamine was not as effective and the effect was not proportional to the dose. Menaquinone had little effect. No difference was observed in the plasma tocopherol levels and peroxide levels in the adipose tissueof the chick fed eith er dilauryl succinate or cornstarch. The effect of dilauryl succinate appears to be independent of peroxides generated in the chick.

Adipose Tissue↗
PubMed1977

Surgical treatment and adjuvant chemotherapy of gastric cancer on the basis of pathological findings.

Gastrectomy was performed in 626 outo 692 operated cases of gastric cancer. Histologic examination of the resected specimens revealed that the cancer was confined to the mucosal (m) or submucosal layer (sm) in 256 cases, advanced to the muscularis propria (pm) or subserosal layer (ss) in 110, and to the serosa (se) or the surrounding organs (si, sei) in 260. 238 (93%) of m and sm cases were free from lymphnode metastasis. Lymphnode metastasis was noted in 51 (46%) of pm and ss cases, 177 (77%) were positive in lymphnode metastasis and 108 (47%) showed metastasis in n2 and n3 degree. Adjuvant chemotherapy fairly improved the psotoperative survival rate of the advanced cases with lymphnode metastasis, serosal involvement, or lymph and blood vessel involement of gastric cancer.

Adult↗
PubMed1977

Cephalosporins. I. Cephaloglycin analogs with six-membered heterocycles in the C-3 side chain.

Cephaloglycin analogs with six-membered heterocycles in the C-3 side chain have been prepared by nucleophilic substitution of 7-aminocephalosporanic acid with appropriate azine thiols followed by 7-N-acylation with phenylglycine by the mixed anhydride method. Seventeen thiols of non-substituted or substituted pyridines, pyridazines, pyrimidines, pyrazines and triazines were used as the S-nucleophiles. In general, pyridazine thiols gave cephalosporins processing good antimicrobial activity against both gram-positive and gram-negative bacteria. Among them 6-hydroxypyridazine-3-thiol gave the most active compound of this series, BB-S 118 (1f), which was significantly more active than cephalexin and cephaloglycin in vitro against gram-positive and gram negative bacteria.

Animals↗