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Biomedical subjects

M Kono

Publications and source records attributed to M Kono.

At least 379 records · Page 21Linked to original sources

A procedure to produce gnotobiotic calves by cesarean section.

An effective and economical method was developed for procuring and rearing calves in gnotobiotic conditions. To evaluate apparatuses and surgical techniques, three calves, 1 to 3, welf 1 was weak and pale at delivery and died within 5 hours after delivery. Calf 2 was delivered alive, but died from a human error at 3 days of age. It was free from demonstrable bacteria and fungi at that time. Calf 3 was also successfully delivered and raised. It was killed at 10 days of age, since fungi were isolated from the feces and waste materials from it.

Animals↗

Outbreaks of swine vesicular disease in japan: virus isolation and epizootiological survey.

Outbreaks of a vesicular disease occurred among pigs in Kanagawa and Ibaraki Prefectures in Japan in November, 1973. Another outbreak was observed in Aichi Prefecture in December. The clinical signs of the disease observed included fever and vesicular lesions on the coronary bands, bulbs of the heel and in the interdigital spaces. In some pigs, vesicular lesions were observed on the snout, tongue and skin overlying the legs and abdomen. All the vesicular samples produced cytopathic changes on cultures of primary swine kidney cells of PK-15 cells. Three isolates of cytopathic agents tested were identified as swine vesicular disease virus from their physicochemical properties and antigenicity. The virus strains isolated from vesicular epithelial samples obtained from Ibaraki, Kanagawa and Aichi Prefectures were designated as Japan/Ibaraki/1/73, Japan/Kanagawa/1/73 and Japan/Aichi/1/73 strain, respectively. An outbreak of the disease among pigs due to swine vesicular disease virus was confirmed by the serum neutralization test with serum samples collected from pigs on affected farms. Approximately 80% of the pigs housed in affected shed showed high levels of neutralizing antibody titers. This is the first to report an occurrence of swine vesicular disease among pigs in Japan.

Animals↗

Relationship between chloramphenicol acetyltransferase activity and the number of resistance genes.

Various mutants of an Escherichia coli K-12 strain were prepared, in which a chloramphenicol (CM) resistance gene (cml) derived from an R factor, R100-1, was integrated into the chromosome. The CM acetyltransferase (CATase) activity of these strains and the strain carrying R100-1 were determined during exponential growth with the following results. (i) The CATase activity varied, depending upon the site of integration of the cml gene on the chromosome. Activity was found to be higher when the cml gene was integrated nearer the replication origin of the chromosome, the total enzyme activity found was the sum of activities coded by each gene separately. (iii) When the cml gene was in a cytoplasmic state on an R factor, R100-1, the expressed enzyme activity was four-to eightfold higher than that in the chromosomal state, suggesting the existence of about four to eight copies of R factor per chromosome. The CATase activity returned to the level of that expressed by R100-1 when the chromosomal cml gene was detached and picked up by an R factor.

Acetyltransferases↗

Enzymatic inactivation of a new aminoglycoside antibiotic, sisomicin by resistant strains of Pseudomonas aeruginosa.

The antibacterial activity of sisomicin (SS), a new aminoglycoside antibiotic active toward clinical isolates of Pseudomonas aeruginosa, was determined and compared with that of the gentamicin C complex. Both drugs were effective against these strains and showed almost the same antibacterial activity. A few strains were found to be resistant to SS. The antibiotic was inactivated by a cell-free extract from the SS-resistant strains due to acetylation of the drug. Comparative studies of the inactivation of the drugs which lack a 6'-amino group in the amino sugar linked to 2-deoxystreptamine strongly suggested that SS inactivation was due to acetylation of the 6'-amino group of the 4',5'-didehydropurpurosamine moiety.

Acetylation↗