Biomedical subjects

K Motokawa

Publications and source records attributed to K Motokawa.

At least 19 recordsLinked to original sources

PubMed1992

Synthesis and antibacterial activity of 1-substituted-methyl carbapenems.

The synthesis of the 1 alpha- and the 1 beta-substituted (fluoro, cyano, hydroxy and acetoxy)-methyl carbapenems having a 2-(1,3,4-thiadiazol-2-yl)thiomethyl side chain are described, and their in vitro antibacterial activities are compared with the corresponding 1 beta-methyl carbapenems together with imipenem. The synthesis and antibacterial activity of the 1 beta-substituted (fluoro and cyano)-methyl carbapenems having 2-(1-alkyl-4-pyridinio)thiomethyl side chains are also described.

Anti-Bacterial Agents↗

PubMed1992

[Orally active cephalosporins. I. Synthesis and structure-activity relationships of 7 beta-[2-(R)-amino-2-phenylacetamido]-3-(1H- 1,2,3-triazol-4-yl)alkylthiomethyl-3-cephem-4-carboxylic acid and related compounds].

The synthesis, antibacterial activity and oral absorbability of 7 beta-[2-(R)-amino-2-phenylacetamido]-3-(1H-1H-1,2,3-triazol- 4-yl)methylthiomethyl-3-cephem-4-carboxylic acid (1a) and related compounds (1b-p and 2) are described. The replacement of 1,2,3-triazole at the C-3 position of 1a with other heteroaromatics such as 1,2,4-triazole, imidazole and so on decreased its oral absorbability in mice (1b-j). The oral absorbability was also influenced by the spacer length between C-3 of cephem nucleus and C-4 of 1,2,3-triazole. The quantitative relationship between the bioavailability and the spacer length of cephalosporins (1a and 1k-p) is discussed. These results suggest that 1,2,3-triazole in the side chain at the C-3 position of cephems plays an important role in good oral absorption through its interaction with the transport system of small intestine.

Animals↗

PubMed1992

Isolation and characterization of new peptide antibiotics, plusbacins A1-A4 and B1-B4.

New antibiotics, plusbacins A1-A4 and B1-B4, were isolated from the culture broth of a strain of Pseudomonas sp. These antibiotics were isolated as a complex by column chromatographies on Diaion HP-20 and silica gel, and then separated by HPLC. They are amphoteric in nature. The hydrochlorides are obtained as colorless powders, soluble in methanol and alkaline water. From their physico-chemical properties, these antibiotics are presumed to be acyloctapeptides containing a lactone linkage, and their differences occur in amino acid and fatty acid residues. The antibiotics are active against Gram-positive bacteria in vitro and in vivo.

Amino Acids↗

PubMed1990

Intrathecal morphine dose-response data for pain relief after cholecystectomy.

We studied the effect of low-dose intrathecal morphine (0.00-0.20 mg) on pain relief and the incidence of side effects after cholecystectomy in 139 patients divided into eight groups according to intrathecal morphine dose: groups 1 (0.00 mg), 2 (0.04 mg), 3 (0.06 mg), 4 (0.08 mg), 5 (0.10 mg), 6 (0.12 mg), 7 (0.15 mg), and 8 (0.20 mg). Preservative-free morphine hydrochloride mixed in hyperbaric tetracaine solution was administered at the time of induction of spinal anesthesia just before surgery. Pain relief was significantly greater for the first 24 h in groups 3, 4, 5, 6, 7, and 8 than in group 1. The incidence of respiratory depression was significantly greater in groups 7 and 8 than in the other groups in the first 48 h. Vomiting occurred significantly more often in group 1 than in groups 2, 3, 4, and 5. Intraoperative cholangiography and the postoperative clinical course indicated no increase in tone of the sphincter of Oddi in any patient. We conclude that 0.06-0.12-mg intrathecal morphine is the best dose range for pain relief after cholecystectomy without respiratory depression and with the lowest incidence of vomiting or pruritus, or both.

Adult↗

PubMed1989