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Biomedical subjects

N Tanabe

Publications and source records attributed to N Tanabe.

At least 127 records · Page 7Linked to original sources
PubMed1983

Cytotoxin production by Clostridium sordellii strains.

A total of 55 strains of Clostridium sordellii, 21 lethal toxin-positive and 34 lethal toxin-negative, were tested for cytotoxin production in brain heart infusion medium supplemented with 0.2% Na2HPO4 (m-BHI) and cooked-meat-glucose (CMG) medium using baby hamster kidney (BHK-21/WI-2) cells as indicator cells. The m-BHI medium was preferred to CMG medium and 24 hr of incubation was sufficient for cytotoxin production. Nineteen of the 21 toxigenic strains were also cytotoxigenic, and the strength of the cytotoxigenicity was approximately parallel with that of the lethal toxigenicity. Clostridium difficile antitoxin neutralized C. sordellii cytotoxin and also C. sordellii antitoxin neutralized C. difficile cytotoxin.

Animals↗
PubMed1982

Carbohydrate fermentation by Clostridium difficile.

Biochemical properties of Clostridium difficile were reinvestigated for the practical identification of the organism in clinical laboratories. Bacterial growth in 2% proteose peptone medium supplemented with 0.01% L-cysteine.HCl and 0.1% agar supported sufficient growth to read the fermentation results just as well as did pre-reduced anaerobically sterilized medium. Incubation for 2 days was long enough for determining the ability to ferment fructose, glucose, mannitol, mannose, melezitose, and sorbitol. All of the 82 strains liquefied 2% but not 10% gelatin. The significance of mannitol fermentation and gelatin liquefaction is stressed since C. difficile is the only species fermenting mannitol among the gelatin-liquefying species of clostridia having subterminal spores.

Carbohydrate Metabolism↗
PubMed1982

Effect of clindamycin on cytotoxin production by Clostridium difficile.

A total of 80 strains of Clostridium difficile, 33 toxigenic and 11 nontoxigenic clindamycin (CLDM)-sensitive (MIC less than 12.5 micrograms/ml), and 23 toxigenic and 13 nontoxigenic CLDM-resistant (MIC 200 to 6,400 micrograms/ml) were tested for cytotoxin production in the presence of CLDM. None of the 24 nontoxigenic strains produced cytotoxin regardless of the presence of CLDM and only six out of the 56 toxigenic strains showed 16- to 64-fold higher levels of cytotoxic activity in the presence of CLDM at the concentrations of 1/2 to 1/32 of the MIC than in the absence of CLDM; all of the six strains were CLDM sensitive. Further studies revealed that addition of CLDM to the culture caused enhanced cytotoxin synthesis, and that the maximum production of cytotoxin was obtained when CLDM was added to the medium at the time of inoculation or of the ensuing early logarithmic phase. Also, the influence of other antibiotics on the effect of CLDM was examined. Addition of metronidazole, vancomycin, chloramphenicol, cephaloridine, or penicillin, which induced cytotoxin to medium containing CLDM did not increase the effect of CLDM any further. Addition of CLDM to medium containing tetracycline, which inhibited cytotoxin production, induced cytotoxin production but not fully.

Anti-Bacterial Agents↗
PubMed1978

A simple large-scale method for separating closed circular form DNA by gel electrophoresis.

The covalently closed form of circular duplex SV40 DNA was separated from the open and linear form of SV40 DNA by agarose gel electrophoresis in a large-scale gel system. The closed circular DNA was recovered from agarose gels by re-electrophoresing the gel slices. The recovery of DNA was about 70%. Electron microscopic analysis showed that the recovered DNA did not have doube- or single-stranded breaks. The recovered DNA can be used without further purification for electron microscopy, as a substrate for experiments using restriction endonuclease and as a template for in vitro RNA synthesis.

Animals↗