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Biomedical subjects

M Ohashi

Publications and source records attributed to M Ohashi.

At least 487 records · Page 27Linked to original sources
PubMed1980

Differential effects of aphidicolin on replicative DNA synthesis and unscheduled DNA synthesis in permeable mouse sarcoma cells.

Aphidicolin clearly discriminated replicative DNA synthesis from unscheduled DNA synthesis. Aphidicolin inhibited replicative DNA synthesis in permeable mouse ascites sarcoma cells. The mode of inhibition of aphidicolin was a mixed type with respect to deoxycytidine triphosphate but was non-competitive with respect to the other three deoxynucleoside triphosphates. Aphidicolin did not affect the activity of unscheduled DNA synthesis in either bleomycin-treated permeable sarcoma cells or isolated rat liver nuclei. Considering the difference in sensitivity of DNA polymerase alpha and beta to aphidicolin, and other related information reported previously, the results are compatible with the idea that DNA polymerase alpha is involved in replicative DNA synthesis and DNA polymerase beta in unscheduled DNA synthesis in the present systems.

Animals↗
PubMed1980

In-beam electron impact mass spectrometry of N-carbobenzoxy derivatives of oligopeptides composed of leucine and isoleucine.

The characteristics of the in-beam electron impact mass spectra of 13 N-carbobenzoxyoligopeptides (up to pentapeptides) composed mainly of leucine and isoleucine, and their alkyl and N-hydroxysuccinimide esters are described. In the cases of di- and tripeptide derivatives, each in-beam electron impact spectrum exhibited an abundant [M + 1]+ peak as well as amino-acyl fragments. However, in the case of pentapeptides the in-beam spectra measured under the routine conditions corresponded to the conventional electron impact spectra of the cyclopeptide derivatives formed by thermal cyclization in the mass spectrometer and few [M + 1]+ ions of the original peptides were observed. From the studies on temperature spectral change of in-beam electron impact spectra it became clear that rapid heating of the sample over the temperature range 200-300 degrees C gave abundant [M + 1]+ ions as well as fragment ions originating from the thermally intact peptide as the major peaks in the spectrum.

Isoleucine↗
PubMed1980

Relationship between antigenic type of virus and antibody response in female patients with herpes genitalis.

The antigenic types of virus recovered from genital sites in cases of adult female genital herpes and antibody response in these patients were investigated. Twelve strains were isolated from 23 clinical specimens, and half the number of the isolates was classified as type 1 virus and the remaining half as type 2 virus. The results of serological typing corresponded well to biological differentiation by plaque-forming ability on chick embryo cultures. The patients with type 1 virus infection had only the complement requiring neutralizing antibody, thus indicating a fresh infection. On the other hand, the noncomplement requiring neutralizing antibody was found in the patients with type 2 virus infection, indicating a later phase of infection.

Adult↗
PubMed1980

An outbreak of acute enteritis due to Campylobacter fetus subspecies jejuni at a nursery school of Tokyo.

An outbreak of acute enteritis due to Campylobacter fetus subspecies jejuni involving a total of 35 out of 74 children occurred at a nursery school of Tokyo in January 1979 and lasted for 7 days. It was the first case of a community outbreak of the disease to be recognized in Japan. The major symptoms observed in the patients consisted of diarrhea (88%), fever (82%), abdominal pain (39%), and vomiting (6.1%). The rate of isolation of the organism from the patients was 39%. Sera of four patients showed elevated agglutinin titers against the organism ranging from 1:80 to 1:320. Although it is suggested that the outbreak was caused by a communal lunch or between-meal snacks prepared by and provided at the nursery school, the incriminated food, source and route of contamination could not be pinpointed.

Acute Disease↗
PubMed1980

Simplified purification and biophysicochemical characteristics of Kanagawa phenomenon-associated hemolysin of Vibrio parahaemolyticus.

Kanagawa phenomenon-associated hemolysin (K-hemolysin) was purified by Sephadex gel and ion-exchange column chromatography, after the culture supernatant had been adsorbed on and eluted from diethylaminoethyl-Sepharose CL-6B, and acid precipitated. K-hemolysin was a heat-stable and trypsin-susceptible protein with an apparent molecular weight of 44,000, the subunit of which was 22,000. The isoelectric point was 4.9. The minimum hemolytic dose was 0.1 mug/ml. The fifty percent lethal dose by intravenous injection was 1.4 mug. Electron microscopy of the small intestine of suckling mice orally challenged with the highest dose (50 mug) not only showed disappearance of epithelial cell microvilli, but also structural disturbances of the endoplasmic reticulum and mitochondrial swelling. One blueing dose representing permeability factor activity was 0.3 mug, and positive reaction in the rabbit ileal loop appeared at above 125 mug. Besides these data in experimental models, we discovered the appearance of an antibody in patients which neutralizes K-hemolysin during the course of the disease. This finding reinforces our view that K-hemolysin plays a most significant role in the pathogenesis of this enteric human disease.

Amino Acids↗