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Biomedical subjects

M Tsumura

Publications and source records attributed to M Tsumura.

At least 37 records · Page 2Linked to original sources
PubMed1986

Chemotherapeutic efficacy of ofloxacin on renal and subcutaneous infection models with Staphylococcus aureus in mice.

Ofloxacin, a new pyridone-carboxylic acid derivative, was evaluated in descending nephritis and subcutaneous abscess models with Staphylococcus aureus in mice in comparison with norfloxacin. Descending nephritis was produced by intravenous injection of S. aureus 39 (MIC 0.78 microgram/ml for ofloxacin and 3.13 micrograms/ml for norfloxacin). Subcutaneous abscess was established by subcutaneous injection of soft agar containing S. aureus 56230 (MIC 0.39 microgram/ml for ofloxacin and 1.56 micrograms/ml for norfloxacin). Three days after infection, the lesions of both models were characterized by purulent inflammation accompanied with massive infiltration of neutrophils and bacterial multiplication. The animals were treated twice a day orally with each compound for 4 consecutive days, and subjected to bacteriological examination 18 h later. In the renal model, the 50% effective doses calculated on the basis of clearance of bacteria from kidneys were 38.4 mg/kg for ofloxacin and greater than 100 mg/kg for norfloxacin. In the subcutaneous model, the 50% effective doses based upon 90% reduction of viable bacteria as compared with untreated controls were 25.2 mg/kg for ofloxacin and greater than 100 mg/kg for norfloxacin. The excellent efficacies of ofloxacin in both infection models are attributed to its high oral absorbability and tissue distribution.

Abscess↗
PubMed1986

Isolation and identification of metabolites of ofloxacin in rats, dogs and monkeys.

Metabolites of (+/-)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7H -pyrido [1,2,3-de][1,4]benzoxazine-6-carboxylic acid (ofloxacin) in excreta of rats, dogs and monkeys after oral administration of 14C-ofloxacin (20 mg/kg) were isolated and identified. Three metabolites of ofloxacin were detected in the excreta of all three species, and identified by t.l.c., u.v., n.m.r. and mass spectrometry as follows: M-1, ester glucuronide of ofloxacin; M-2, unchanged ofloxacin; M-3, (+/-)-9-fluoro-2,3-dihydro-3-methyl-10-(1-piperazinyl)-7-oxo-7H-pyrido [1,2,3-de][1,4]benzoxazine-6-carboxylic acid (desmethyl ofloxacin); M-4, (+/-)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7H -pyrido [1,2,3-de][1,4]-benzoxazine-6-carboxylic acid piperazine-4-oxide (ofloxacin N-oxide). It is concluded that ofloxacin is metabolized by O-acyl glucuronidation, N-demethylation and N-oxidation.

Animals↗
PubMed1986

[Hemodynamic change in the liver following hepatic resection in the dog. A comparative study by the 198Au colloid method, KICG and the H2 clearance method].

On the basis of our hypothesis that blood flow in the residual hepatic parenchyma is a determinant factor of posthepatectomy liver function, measurements were made of blood flow in the residual liver after 40% hepatic resection in dog. Adult mongrel dogs were divided into two groups, i.e., normal control and 40% hepatectomy, and evaluated for hepatic hemodynamics by 198Au colloid method, KICG and H2 clearance method. Blood biochemistry and, histology of the liver were also examined. The results are as follows: In the control group, hepatic blood flow by 198Au colloid method, KICG and H2 clearance method was found to correlate significantly with each other. In the 40% hepatectomy group, the hepatic blood flow index by both 198Au colloid method and KICG decreased in proportion to the amount of resected hepatic tissue initially and then increased as the liver regenerated. H2 clearance method showed that hepatic blood flow per unit weight of tissue decreased in the face of reduced hepatic volume in early stage of posthepatectomy period and returned to the preoperative level as the liver regenerated.

Alanine Transaminase↗
PubMed1980

Metabolsim of vasodilator 4-(3,4,5-trimethoxycinnamoyl)-1-(1-pyrrolidinyl)carbonylmethylpiperazine (cinepazide): isolated and identification of metabolites in the rat and man.

Further study on identification of metabolites of cinepazide, 4-(3,4,5-trimethoxycinamoyl)-1-(1-pyrrolidinyl)carbonylmethylpiperazine, in rats and men was carried out. New metabolites of cinepazide in rat urine were 4-[1-[4-(3,4,5-trimethoxycinnamoyl)-piperazinly]acetamidol-1-butanol (M-II), 4-(3,4,5-trimethoxycinnamoyl)-1-[1-(hydroxypyrrolidinyl)]carbonylmerthylpiperazine (M-IV) and 4-[1-[4-(3,4,5-trimethoxycinnamoyl)piperazinyl]acetamidol]-1-butyric acid (M-VI). Structures of two mono-O-demethylated metabolites of cinepazide predicted in the previous paper were assigned as 3-hydroxy-4,5-dimethoxycinnamoyl and 4-hydroxy-3,5-dimethoxycinnamoyl compounds (M-III and M-V) by the FT-NMR spectrometry measured in a mixture of CDC13-C6D6 (1:1, v/v) after methylation with dimethylsulfare-d6. The corresponding pyrrolidone metabolite of cinepazide was undetectable in rat urine. New metabolites of cinepazide in rat feces were found to be 4-(3,5-dihydroxy-phenethylcarbonyl)-1-(1-pyrrolidinyl)carbonylmethylpiperazine (M-VIII) and 4-(3,5-dihydroxycinnamoyl)-1-(1-pyrrolidinyl)carbonylmethylpiperazine (M-IX). Metabolites of cinepazide in human urine were studied by both methods--high performance liquid chromatography and mass spectrometry with ion cluster technique. Unchanged drug was mainly excreted in the urine, and M-VI was the major urinary metabolite. The existence of M-IV and M-V was suggested by high performance liquid chormatography. The corresponding pyrrolidone was also undetectable in human urine.

Animals↗