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Biomedical subjects

K Katsu

Publications and source records attributed to K Katsu.

At least 73 records · Page 4Linked to original sources
PubMed1992

In vitro activity of E1040 against imipenem-resistant Pseudomonas aeruginosa strains.

E1040 showed the most potent activity (MIC for 90% of strains, 6.25 micrograms/ml) among beta-lactams tested against 70 strains of imipenem-resistant Pseudomonas aeruginosa. Two strains showed high-level resistance to E1040; one strain produced a type II oxyiminocephalosporin-hydrolyzing beta-lactamase (group 3), and the other produced an enzyme similar to a type II penicillinase (OXA-1). Both beta-lactamases contributed to resistance to E1040.

Anti-Bacterial Agents↗
PubMed1992

Cefclidin (E1040), a novel cephalosporin: lack of selection of beta-lactamase overproducing mutants in an in vitro pharmacokinetic model system.

The bactericidal activity of cefclidin (E1040), a new cephalosporin, against a clinical strain of Citrobacter freundii was compared with that of ceftazidime in a two-compartment in vitro pharmacokinetic model system designed to simulate plasma concentrations in humans for 12 hours after intravenous administration of a 1 g dose. Both cefclidin and ceftazidime showed rapid bactericidal activity against C. freundii. However, during the simulation of ceftazidime treatment, regrowth was observed after two hours and a subpopulation emerged which was resistant to ceftazidime. Neither regrowth nor the emergence of resistant mutants was observed with cefclidin during the 12-hour simulation. The ceftazidime-resistant mutants constitutively overproduced beta-lactamase at levels which were about 500-fold higher than that of the parent wild-type strain. Against this beta-lactamase overproducing mutant, no bactericidal activity of ceftazidime was observed in the in vitro model system, whereas the bactericidal activity of cefclidin was observed during the 12-hour period. The emergence of Enterobacter cloacae mutants derepressed for beta-lactamase production was also observed with ceftazidime but not cefclidin. The affinity of cefclidin for the beta-lactamase isolated from these mutants was lower than that of ceftazidime, and the kinetic parameters of enzymatic hydrolysis showed that cefclidin was hydrolyzed more slowly at a low concentration (0.2 microM) than was ceftazidime. It is suggested that the high activity of cefclidin against strains derepressed for beta-lactamase plays a major role in the absence of emergence of resistant mutants.

Bacteria↗
PubMed1992

[Effect of cefclidin and E1077, new cephalosporins, on the alcohol-metabolizing system in rats].

Administration of latamoxef and cefoperazone, reported to act like disulfiram in humans, caused a depression of mitochondrial low Km aldehyde dehydrogenase (low Km ALDH) activity in rats. In addition, a marked increase of blood acetaldehyde concentration was observed when rats were given alcohol orally at 18 hours after administration of these cephalosporins. However, mitochondrial low Km ALDH activity and blood acetaldehyde level were not altered by repeated administration of 300 mg and 1,000 mg of cefclidin (CFCL, E1040) or E1077 per kg. From these results, it was concluded that neither CFCLn or E1077 affected the alcohol metabolizing-system.

Acetaldehyde↗
PubMed1990

Prophylactic activity of dihydroheptaprenol, a synthetic polyprenol derivative, against Sendai virus infection in mice.

The effect of a chemically synthesized polyprenol derivative, dihydroheptaprenol (DHP), on the non-specific resistance of mice to Sendai virus infection was investigated. The mice that received 200 micrograms of DHP intranasally twice, at 3 days and 1 day before the infection, showed a significant protection against Sendai virus infection. Treatment of mice twice even with as much as 2000 micrograms of DHP through the subcutaneous route, however, had no protective effect against infection. Excess interferon and tumour necrosis factor production in intranasally DHP-treated mice was seen 1 day after the infection when compared with Sendai virus alone controls or with DHP alone controls. Variance analysis of these findings indicates a prophylactic activity of DHP in pulmonary viral infections.

Administration, Intranasal↗
PubMed1990

Examination of toxicity of diisopropylammonium dichloracetate (DADA), remedies for cardiac diseases, toward isolated rat hepatocytes.

Oxygen uptake (OU) and cell viability (CV) of isolated rat hepatocytes as a part of the indexes of hepatopathy were determined following treatment with DADA, the active principle of pangamic acid. DADA increased OU at high concentrations, but not at low ones. However, CV became higher as the concentration became lower. DADA led to no remarkable toxicity when used alone. When the mixture of DADA and calcium gluconate was tested, DADA showed no palliative action; nor did it when combined with other hepatotoxins such as trapidil, rifampicin, hexobarbital, thiopental sodium, and Citanest-octapressin.

Animals↗
PubMed1990

Determination of 2,5-hexanedione and N-methylformamide in urine by gas chromatography.

Methods for the clinical testing of 2,5-hexanedione and N-methylformamide, urinary metabolites of n-hexane and N,N-dimethylformamide, respectively, were established by capillary column GLC. Recovery rates of 2,5-hexanedione and N-methylformamide from urine were 80.2-108.9% and 99.6-104.2%, respectively. Coefficients of variation (C.V.) for the amount of each product added were 3.1%, 1.8% (intra-assay) and 5.7%, 3.3% (inter-assay), respectively. The concentration ranges of metabolites from urine of healthy subjects without exposure to these organic solvents were less than or equal to 0.5 mg/l (2,5-hexanedione), less than or equal to 1.5 mg/l (N-methylformamide), respectively.

Air Pollutants, Occupational↗
PubMed1990

Studies on clinical markers of diabetes mellitus. 6. Red blood cell sorbitol and diabetic complications.

The relationship between red blood cell sorbitol content and diabetic complications (cataract, retinopathy, neuropathy, and nephropathy) was examined in 23 non-insulin-dependent diabetic (NIDD) patients. Sorbitol content was abnormally high in 21 cases out of 23 NIDD patients. Sorbitol content in the non-neuropathy group and neuropathy group was 47.3 +/- 11.9 and 59.6 +/- 23.6 nmol/gHb, respectively. In the non-cataract group and cataract group, it was 49.0 +/- 17.6 and 66.0 +/- 23.5 nmol/gHb, respectively. The contents in the Scott I group and Scott II + III group were 54.9 +/- 20.7 and 58.7 +/- 24.0 nmol/gHb, respectively. Sorbitol content in the non-nephropathy group and nephropathy group was 52.8 +/- 19.8 and 61.1 +/- 21.9 nmol/gHb, respectively. The possibility that glyceraldehyde reductase (GAR) and sorbitol dehydrogenase (SDH) levels in red blood cells are also useful indicators of the presence of diabetic complications is strongly suggested.

Biomarkers↗
PubMed1990

[Effect of endothelin on gastric mucosal lesion in rats].

Gastric mucosal blood flow and gastric mucosal prostaglandin E2 (PGE2) and prostacyclin (PGI2) were investigated in male Wistar rats intraarterially injected with endothelin (ET), an endothelium-derived vasoconstrictor peptide. Immediately following ET (4 nmol/kg) administration, gastric mucosal blood flow decreased. Then 30 min later, the blood flow reached the minimum, but PGE2 and PGI2 showed the highest value. PGE2 showed a tendency to decrease 90 min later, while PGI2 continued to show high value. There were redness and hemorrhagic damage in the gastric mucosa. Endogenous PGs were presumed to be relate to the regulation of the development of the mucosal damage owing to decrease in the blood flow after ET administration.

Animals↗
PubMed1989

[Studies on the new clinical marker of diabetes mellitus (5). Seasonal variation of insulin specific binding to erythrocyte insulin receptor].

Specific binding of insulin to receptors of healthy human erythrocytes was slightly increased in December (6.9 +/- 1.7%) compared with that in May (5.1 +/- 1.4%). Random screening of insulin specific binding to erythrocyte insulin receptors of various patients (including not only diabetes mellitus but also other diseases) suggested that insulin specific binding is slightly higher in winter than in summer. Insulin specific bindings of healthy subjects in Sapporo (January, -6.1 degrees C), Saitama (5.1 degrees C) and Okinawa (16.0 degrees C) were 9.1 +/- 1.6%, 6.9 +/- 1.7%, 6.2 +/- 1.7%, respectively. A week negative correlation was observed between atmospheric temperature and insulin specific binding. These results suggest that insulin specific binding to the erythrocyte insulin receptor is affected by not only the pathological situation of the patient, but also season and atmospheric temperature.

Diabetes Mellitus↗
PubMed1988

In vitro evaluation of E1040, a new cephalosporin with potent antipseudomonal activity.

E1040 is a new parenteral cephalosporin with a broad antibacterial spectrum and potent antipseudomonal activity. The compound was four- to eightfold more active than ceftazidime and cefsulodin against Pseudomonas aeruginosa (MIC of E1040 for 90% of strains tested [MIC90], 3.13 micrograms/ml). E1040 also showed a potent activity against other glucose-nonfermentative rods, including Acinetobacter species. The activities of E1040 against most species of the family Enterobacteriaceae were roughly comparable to the activities of ceftazidime and cefmenoxime and exceeded that of cefotiam. Against Citrobacter freundii (MIC90, 0.78 micrograms/ml), Enterobacter cloacae (MIC90, 3.13 micrograms/ml), and Enterobacter aerogenes (MIC90, 0.2 micrograms/ml), E1040 was 16- to 256-fold more active than ceftazidime and cefmenoxime. The activities of E1040 against gram-positive cocci and anaerobes were comparable to those of ceftazidime, but the compound was less active than cefmenoxime. E1040 was at least as resistant as ceftazidime and cefmenoxime to hydrolysis by various beta-lactamases and showed high affinities for penicillin-binding protein 3 of both Escherichia coli and P. aeruginosa.

Bacteria↗
PubMed1987

E-0702, a new cephalosporin, is incorporated into Escherichia coli cells via the tonB-dependent iron transport system.

E-0702, a new cephalosporin with a potent antipseudomonal action, was synthesized. In the study of the mode of action of this antibiotic in Escherichia coli, it was found that mutants which acquired resistance to E-0702 were isolated spontaneously and could be shown to be susceptible to its closely related derivatives, E-0702-060 and E-0702-061, and other representative beta-lactam antibiotics. In these mutants, no increased production of beta-lactamase was detectable. No apparent differences between the resistant mutants and the parental strains were observed in the affinity of E-0702 for penicillin-binding proteins. Furthermore, no significant reduction in or loss of both OmpF and OmpC porin proteins in the outer membrane was observed. The mutation was mapped to the tonB gene, which is known to be essential for the iron transport system of bacteria. The bactericidal action of E-0702 was rapidly expressed against iron-starved cells in which the iron transport system was induced, whereas the bactericidal action against iron-supplemented cells was ineffective. It is suggested that E-0702 is incorporated into bacterial cells as a chelator of iron via the tonB-dependent iron transport system, after which its strong and rapid bactericidal action is manifested.

Bacterial Outer Membrane Proteins↗
PubMed1984

[Evaluation of tegafur encapsulated with slow-releasing granules (SF-SP) for patients with cancer of the digestive organs].

A new anticancer therapy using tegafur encapsulated in slow-releasing granules (SF-SP) was orally administered at a dose of 1000 mg/day to 38 patients with cancer of the digestive organs. Twenty-eight of these patients were evaluable for response using the criteria of Saito and Koyama's clinical evaluation. Six of 28 patients showed effective response (21.4%). An effective response was observed in of 15 patients with gastric cancer (26.7%). Side-effects from this therapy were encountered in 14 patients (36.8%). An effective response was therefore demonstrated in patients with cancer of the digestive organs.

Administration, Oral↗