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Biomedical subjects

S Ishihara

Publications and source records attributed to S Ishihara.

At least 397 records · Page 22Linked to original sources
PubMed1982

Failure to validate the growth of Mycobacterium leprae on M-Y 14b agar medium.

Confirmation experiments on colony formation of M. leprae on the M-Y 14b agar medium developed by Murohashi and Yoshida were carried out for two years independently by individual members of an organized research group, according to the method described by Murohashi and Yoshida. The results obtained can be summarized as follows: a) No colony production by M. leprae on M-Y 14b agar medium was seen. b) No increase in the number of cells of M. leprae on M-Y 14b agar medium during cultivation was seen. c) Light and electron microscopic observation indicated that there was an increase in the number of non-solid bacterial cells and ghost cells with time of cultivation. d) It was found by mouse foot pad inoculation that four of six samples of M. leprae used as inocula were definitely viable. e) By means of mouse foot pad inoculation, it was shown that viability of M. leprae inoculated onto M-Y 14b agar medium was lost within approximately seven weeks of cultivation. From these results, can be definitely concluded that there is no evidence indicating that multiplication of M. leprae took place on M-Y 14b agar medium.

Agar↗
PubMed1982

Bacteriological evaluation of midecamycin acetate and its metabolites.

In vitro midecamycin acetate was shown to have broad spectrum of antibacterial activities similar to those of other macrolides (midecamycin, josamycin, 9-propionyl josamycin and 2'-ethylsuccinyl erythromycin), which include Gram-positive organisms, a part of Gram-negative organisms and anaerobes. Metabolites of midecamycin acetate also showed certain degree of antibacterial activities although they gave higher MIC values than midecamycin acetate. The antibacterial activities of midecamycin acetate were potentiated in the medium with pH 7 or pH 8 and little affected by inoculum size or addition of human serum into the medium. Both midecamycin acetate and its metabolites were found to have relatively high protein binding rates. In vivo therapeutic experiments in experimental infections in mice, midecamycin acetate was shown to be much superior to other drugs tested in the therapeutic efficacy against intraperitoneal infections caused by Staph. aureus, Strept. pyogenes, Strept. pneumoniae and Cl. perfringens. In infections transnasally induced by Strept. pneumoniae, midecamycin acetate showed therapeutic efficacy 2 or 5 times greater than that of josamycin or midecamycin, despite that MICs of midecamycin acetate were equal to josamycin or midecamycin. Moreover, midecamycin acetate showed high therapeutic efficacy for subcutaneous infections due to Staph. aureus, suggesting that it exerts pronounced antibacterial activities against not only systemic infections but also local infections.

Ampicillin↗
PubMed1982

Open versus closed position fixation of bioprosthesis. Comparative in vitro studies from the viewpoint of durability.

In an effort to normalize the dynamic leaflet behavior of a porcine bioprosthesis, an experimental attempt was made to treat a tissue heart valve with 0.625% glutaraldehyde in the open position ("open-type valve"). Eighteen open-type valves, having fixed openings of various sizes, were examined with our pulse simulators. Eight closed-type valves, which were treated in the closed position, were studied for comparison. The results showed that closed-type valve tended to offer an immobile cusp at a low flow state; at a pump pressure of 90 mm Hg in a pulsatile flow or under steady flows of no more than 10 L/min. By contrast, the open-type valve showed the symmetric cusps opening with circular orifices at any given flow rates. Analysis of the pressure loss coefficient revealed that the leaflets prepared in the open position produced only a minimal impediment to the forward flow. One half of the anatomic orifice of a valve was considered to be the optimal size for the fixed opening. It is concluded that open position fixation is expected to provide the bioprosthesis with improved fatigue durability in patients with low cardiac output syndrome and in small children.

Aortic Valve↗
PubMed1981

An enzyme immunoassay for plasma betamethasone.

A sensitive enzyme immunoassay for plasma betamethasone was developed using betamethasone-3-(O-carboxymethyl)oxime-beta-D-galactosidase conjugate as a labelled antigen and 4-methylumbelliferyl-beta-D-galactoside as a fluorescence substrate. The performances of the enzyme immunoassay were compared with that of a radioimmunoassay using 3H-betamethasone and the same antiserum. The minimal detectable level for the enzyme immunoassay was 0.15 pg/tube or 0.15 ng/ml of plasma, which was remarkably more sensitive than the radioimmunoassay level of 10 pg/tube or 2 ng/ml of plasma. The specificity was sufficient, in particular, the cross reactivity of cortisol as 0.008%. However, the precision of the enzyme immunoassay was inferior to that of the radioimmunoassay.

Betamethasone↗
PubMed1980

A case of insulin autoimmune syndrome associated with small insulinomas and rheumatoid arthritis.

Twenty five cases of insulin autoimmune syndrome including this case has been reported so far without having the pathogenesis clarified. This paper describes a case which suggests one aspect of pathogenesis. The patient, a housewife concurrently had insulinoma and severe rheumatoid arthritis, complaining of hypoglycemic syncope attacks. During the attacks her blood sugar levels ranged from 19 to 22 mg%. Her serum extractable immunoreactive insulin (IRI) and insulin binding antibody levels were 557 microunits/ml and 0.390 mU/ml, respectively. gamma-Globulin-bound insulin was also measured electrophoretically. Bio-Gel P 10 column chromatography eluted almost all IRI at the void volume at pH 7.4 and a smaller but significant IRI peak also at pH 3.0. Selective angiography revealed a tumor-like staining in the pancreas body. Pancreatectomy relieved her of hypoglycemic attacks. Histology disclosed two small insulinomas. Insulinoma, rheumatoid arthritis and insulin autoimmune syndrome coexisted in this case, suggesting some causal relationship among them.

Adenoma, Islet Cell↗