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Biomedical subjects

Y Usui

Publications and source records attributed to Y Usui.

At least 163 records · Page 9Linked to original sources
PubMed1979

Factors causing the clumping reaction of streptococcal strains with human plasma.

Fresh isolates of 204 strains of Streptococcus haemolyticus, 75 strains of viridans group Streptococcus, and 45 strains of Streptococcus pneumoniae were studied for their clumping reactions with human plasma. The plasma and serum factors that clumped the streptococcal strains were compared with those that clumped a Staphylococcus aureus strain. One hundred eleven strains of S. haemolyticus, 10 strains of viridans group Streptococcus, and none of the strains of S. pneumoniae tested were clumped by human plasma. However, clumping activity was remarkably unstable after subculturing on plates containing Todd-Hewitt blood agar. The strain with the highest level of activity was clumped by fibrinogen and normal human serum. Results of tests of the clumping reactions of staphylococci and streptococci with human serum indicated that the serum factors responsible for those reactions may be identical.

Bacteriological Techniques↗
PubMed1979

[Effect of combination of hetacillin, cephapirin and amikacin (author's transl)].

With the investigations of the effect of combination of hetacillin, cephapirin and amikacin, following experimental results were obtained; 1. Effect of combination of amikacin, cephapirin and hetacillin was differed depending upon the genus and species of bacteria. However, in general, in the cases showing effective results there was a relation in the concentration of these antibiotics. With strains of Escherichia coli amikacin and cephapirin was cooperative, but not with other combinations and strains of Proteus showed similar tendencies to those strains. In the strains of Pseudomonas, no effect was observed with these antibiotics. However, significant cooperative effect was shown in strains of Klebsiella pneumoniae. In penicillin-resistant strains of Staphylococci cooperative effect was represented only a combination of amikacin and hetacillin. 2. Amikacin was resistant against penicillinase isolated from penicillin-resistant strain of Staphylococcus and cephalosporinase extracted from cephalosporin-resistant strain of Escherichia coli. 3. When a strain of K. pneumoniae, showing cooperative effect with amikacin and cephapirin, was examined by electronmicroscopy, enlargement of cells and destruction of the cell walls were observed.

Amikacin↗