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Biomedical subjects

K Matsuda

Publications and source records attributed to K Matsuda.

At least 613 records · Page 34Linked to original sources
PubMed1988

Fetal breathing adaptation to prolonged hypoxaemia in sheep.

Prolonged (6 days) fetal hypoxaemia was produced by placing pregnant ewes in an environmental chamber. A constant flow of N2 into the chamber reduced the fraction of inspired oxygen (Fi02) to 0.139 +/- 0.001, simulating an altitude of 4270 m. This reduced maternal PaO2 by about 39 mmHg and PaCO2 by nearly 5 mmHg, which produced a hypocapnic (delta PaCO2 = -5 mmHg) hypoxaemia (delta PaO2 = -8 mmHg) in the fetus. An analysis of the first 4 h of breathing recorded each day (1800-2200 h; start of hypoxaemia: 1200 h) showed that the incidence (12 +/- 2.0 min/day) during the first day of hypoxaemia was significantly less (P less than 0.05) than that (24 +/- 3.1 min/h) during the same time of the control day. By the second day, breathing had returned to normal. Further analysis indicated that a normal incidence of breathing may have occurred as early as 14 h after starting hypoxaemia. These results suggest that fetal breathing movements adapt rather quickly to this degree of hypocapnic hypoxaemia.

Acclimatization↗
PubMed1988

[A case of hypercalcemia with ovarian carcinoma].

A 45-year-old female manifested lower abdominal fullness and symptoms of hypercalcemia with nausea, vomiting, and thirst. Physical examination showed a right ovarian mass and laboratory data demonstrated hypercalcemia (14.6 mg/dl). The radiographic findings confirmed a right ovarian tumor without any evidence of bone metastasis. Tests revealed that her PTH, nephrogenic urinary cyclic AMP, and 1-25 (OH)2 Vitamin D were not high but that her prostaglandin E2 (PGE2) was elevated. After correction of her calcium elevation with infusion and prednisolone, right oophorectomy with tumor excision was performed. A histological examination of the tumor revealed a mucinous cysto-adenocarcinoma. The postoperative course has been uneventful, with normal calcium and PGE2 values. This case illustrates that hypercalcemia associated with an ovarian carcinoma (Malignancy-associated hypercalcemia) can be mediated by the patient's PGE2 in part.

Combined Modality Therapy↗
PubMed1987

Stimulation of prostaglandin production by (2E,6Z,10E)-7-hydroxymethyl-3,11,15-trimethyl-2,6,10,14-++ +hexadecatetrae n-1-ol (plaunotol), a new anti-ulcer drug, in vitro and in vivo.

Plaunotol [(2E,6Z,10E)-7-hydroxymethyl-3,11,15-trimethyl-2,6,10,14- hexadecatetraen-1-ol], a new anti-ulcer drug, was investigated for its effect on prostaglandin (PG) production. In cultured cells of 3T6 fibroblasts, plaunotol and its main metabolite (1-carboxylic plaunotol) at concentrations of 10-100 microM increased PGE2 and PGI2 production 2- to 4-fold. These compounds increased the release of radioactive arachidonic acid from [14C]arachidonic acid prelabeled 3T6 fibroblast cells 2-fold at 30 microM, and this increase was inhibited by addition of mepacrine, a phospholipase inhibitor. Plaunotol and its main metabolite had no effect on PG cyclooxygenase activity. These results indicate that plaunotol and its main metabolite stimulate PG production by activating cellular phospholipase. In gastric-mucosa slices, PGE2 and PGI2 production was increased significantly either by oral administration of plaunotol to rats at a dose of 300 mg/kg or by addition of the main metabolite to the incubation medium. All these results suggest that plaunotol increases the PG levels in gastric mucosa by stimulating the PG biosynthesis, particularly the cellular phospholipase activity. The increased levels of PG may participate in the anti-ulcer activity of plaunotol.

Administration, Oral↗
PubMed1987

Characteristics of murine yolk sac erythroid progenitors and their population expansion in liquid culture.

Remarkable differences were found between late erythroid progenitors (CFU-e) in cultures of murine yolk sac cells and those of fetal liver cells with respect to frequency, erythropoietin responsiveness and colony size. Cultures of yolk sac on day 11 of gestation showed a CFU-e population of lower frequency, less sensitivity to erythropoietin and smaller colony size than those from cultures of day 14 fetal liver cells. As the proportion of CFU-e to BFU-e was much lower in yolk sac than that in fetal liver, 48-96 h liquid culture experiments were done with these cells to examine the capacity of their precursors to generate a certain amount of CFU-e subpopulations. The cultures of yolk sac cells produced large numbers of CFU-e which formed some large-sized colonies but those of fetal liver cells generated only a small amount of CFU-e.

Animals↗
PubMed1987

Structure-activity relations of 4-fluoromethyl monobactams.

New monobactam compounds with fluoromethyl side chains at the 4-position were synthesized. These compounds showed strong antibacterial activity against Gram-negative bacteria including Pseudomonas aeruginosa and good stability to various beta-lactamases. The effect of replacement of the 1-carboxy-1-methylethoxyimino residue of aztreonam with various substituted groups, and of the configuration of the 3- and 4-position were examined. Substitution of a carboxycyclopropoxy group in the oxyimino moiety effected the most potent antibacterial activity. The cis congeners were not hydrolysed by any types of beta-lactamases including the oxyiminocephalosporin hydrolysing enzyme. Introduction of a fluorine atom in the methyl group at the 4-position increased the beta-lactamase stability of monobactams.

Bacteria↗
PubMed1987

Biological activity of BO-1236, a new antipseudomonal cephalosporin.

BO-1236, a new cephalosporin having an N-methyl-5,6-dihydroxyisoindolinium moiety on the 3-methylene of the cephem, showed potent activity against gram-negative organisms, including Pseudomonas aeruginosa. The in vitro activity of BO-1236 was superior or comparable to that of ceftazidime, cefotaxime, and cefoperazone in susceptibility tests with clinical isolates. BO-1236 was significantly more active than ceftazidime against P. aeruginosa strains susceptible or resistant to ceftazidime or gentamicin or both. MBCs were usually close to MICs, both of which were influenced by inoculum size to about the same degree as those of the other beta-lactams. BO-1236 was stable to all types of beta-lactamases except type I oxyiminocephalosporin-hydrolyzing enzyme, by which BO-1236 was slightly hydrolyzed. BO-1236 showed protective activity superior to that of ceftazidime and cefotaxime in experimental infections in mice caused by two strains of P. aeruginosa and showed activity comparable to that of ceftazidime and cefotaxime against other gram-negative bacterial infections.

Animals↗