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Biomedical subjects

S Oda

Publications and source records attributed to S Oda.

At least 505 records · Page 28Linked to original sources
PubMed1980

Muscle fatigue in relation to EMG during repeated and maintained maximal isometric contractions.

The decrease of muscular force output during two different maximal isometric voluntary contractions of knee extension were studied for 6 male subjects in relation to EMG. EMGs were recorded by bipolar surface electrodes from the m. vastus lateralis and were integrated by a modified Miller's circuit. In repeated contractions at one-second intervals, only slight changes were observed in the integrated EMG despite a marked decrease in force output to about 45% of the initial value. In counterparts of the maintained contraction for 2 min, both force output and integrated EMG decreased with time, and tended to plateau at a level corresponding to 20% and 45% of the initial value, respectively. From the viewpoint of blood supply, it was concluded that in the repeated contractions the decrease in force output was mainly due to the local factors in the muscle, especially in the fast twitch fibres, while in the maintained contraction in decrease in force output was caused not only by the failures in local factors but also central fatigue.

Adult↗
PubMed1979

Salt-induced conformational changes in skeletal myosin light chains, troponin-C, and parvalbumin.

Evidence for salt-induced changes in myosin light chains [dissociated by treatment with 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB)], troponin-C (TnC), and parvalbumin was obtained from chymotryptic digestion, circular dichroism, fluorescence, and difference absorption studies. High salt (0.6 M NaCl) protects the DTNB light chain from proteolysis, increases its alpha-helical content, and quenches the tryptophan fluorescence. These effects are similar to the changes induced by Ca2+ but smaller in magnitude. TnC is affected by monovalent cations in a similar manner. Changes in the alpha-helical content resemble the effect of Ca2+. The enhancement of tyrosine fluorescence reflects conformational changes in the Ca2+-Mg2+ binding sites. The increase in the fluorescence of dansylaziridine-labeled TnC suggests perturbation of Ca2+-specific sites by salt. Cancellation of this effect by Mg2+ binding to the high-affinity sites is indicative of site-site interactions. In Whiting parvalbumin, salt-induced a perturbation of tryptophan absorption similar in nature to the Ca2+ effect.

Animals↗
PubMed1978

A case of red-cell adenosine deaminase overproduction associated with hereditary hemolytic anemia found in Japan.

A case of red cell adenosine deaminase (ADA) overproduction associated with hereditary hemolytic anemia is reported here. This appears to be the second report. Proband is a 38-year-old Japanese male who had hemoglobin, 15.8 g/100 ml; reticulocyte count, 4.5%; serum indirect bilirubin, 4.9 mg/100 ml; 51Cr-labeled red cell half-life, 12 days; red cells showed moderate stomatocytosis. His red cell ADA activity showed 40-fold increase while that of the mother showed 4-fold increase. The mother was hematologically normal. The father had a normal enzyme activity. The proband and the mother showed slightly high serum uric acid levels. The proband's red cell showed: ATP, 628 nmoles/ml (normal, 1,010--1,550); adenine nucleotide pool, 46% of the normal mean; 2,3-diphosphoglycerate content, 3,782 nmoles/ml (normal 4,170--5,300); increased oxygen affinity of hemoglobin, P50 of intact erythrocytes being 21.8 mmHg (normal, 24.1--26.1). Red cell glycolytic intermediates in the proband were low in general, and the rate of lactate production was low. Kinetic studies using crude hemolysate revealed a normal Km for adenosine, normal electrophoretic mobility but slightly abnormal pH curve and slightly low utilization of 2-deoxyadenosine. The ADA activity of lymphocytes was nearly normal.

Adenosine Deaminase↗
PubMed1978

Relationship of density distribution and pyruvate kinase electrophoretic pattern of erythrocytes in sickle cell diseases and other disorders.

The density distributions of red cells from sickle cell disorders and other hematological diseases were determined. In sickle cell anemia there was an increase in the proportion of cells in both the heaviest and lightest fractions. In hemoglobin SC disease, a small fraction was shifted to heavier cells. Sickle cell trait blood had a normal density pattern. In hereditary spherocytosis an increase in the number of heavy cells was observed. Thin-layer polyacrylamide gel electrophoresis of red cell pyruvate kinase demonstrated that the pyruvate electrophoretic pattern was related to density distribution.

Anemia↗
PubMed1975

[In vitro examination on antibacterial activities of broad-spectrum antibiotics against gram-negative clinical isolates (author's transl)].

In vitro studies were undertaken on clinically isolated strains of various bacteria to examine the antibacterial activity of ampicillin (AB-PC), carbenicillin (CB-PC), sulbenicillin (SB-PC) cephalothin (CET), cefazolin (CEZ) and gentamicin (GM). Fifty three % of Escherichia coli strains 53.3% of Citrobacter sp., 80% of Proteus mirabilis, 42.9% of Morganella and 80% of Bacteroides sp. were susceptible (MIC being not higher than 12.5 mug/ml) to AB-PC. The eight other species were not so susceptible to this penicillin. CB-PC and SB-PC were almost as effective as AB-PC against Escherichia coli and Citrobacter sp. They were less active against Klebsiella sp., but more active against Enterobacter sp., Serratia sp., indole-positive Proteus group and Pseudomonas sp. than AB-PC, SB-PC was more effective than CB-PC against Pseudomonas sp. The strains of Pseudomonas sp. which were resistant to higher concentrations of CB-PC and SB-PC were pyocyanine-negative strains. All strains (100%) of Escherichia coli, Klebsiella sp. and Citrobacter sp. were susceptible to CET and CEZ, while none of Enterobacter sp. , Serratia sp., Proteus vulgaris. Morganella, Rettgerella, Providencia and Pseudomonas sp. were susceptible to these cephalosporins. The MICs of CET and CEZ against Bacteroides sp. were moderately low. Some strains of Providencia and Alkaligenes sp. were resistant of GM but the other 10 species were not resistant to this antibiotic, though it showed comparatively high MICs against Bacteroides sp. When seen from the MIC distribution of each antibiotic, there was a tendency that the strains isolated from the pus were more resistant than those isolated from the other sources (urine, sputum and bile).

Ampicillin↗