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Biomedical subjects

K Sawa

Publications and source records attributed to K Sawa.

36 records · Page 2Linked to original sources
PubMed1985

Antibacterial activity of cefminox against anaerobes.

The antibacterial activity of cefminox (CMNX) against anaerobic bacteria was studied in vitro. The results are as follows: 1. CMNX exerted antibacterial activity against a wide range of anaerobes, excluding Clostridium innocuum. The antibacterial activity of CMNX against Bacteroides fragilis was comparable to that of latamoxef and superior to cefoxitin, but CMNX's activity against anaerobic cocci was slightly inferior to cefoxitin's; 2. A comparison of the MICs and MBCs of CMNX indicated that this drug exerts a complete bactericidal effect at a concentration which inhibits the growth of bacteria; 3. CMNX was found to be stable to the beta-lactamases produced by B. fragilis; 4. CMNX exerted an antibacterial activity against C. difficile.

Anti-Bacterial Agents↗
PubMed1983

The beta-lactamases of genus Bacteroides.

Two hundred anaerobic isolates from clinical specimens were examined for beta-lactamase production by Nitrocefin methodology. Altogether, 77 strains were beta-lactamase producers. Organisms belonging to Bacteroides melaninogenicus group, i.e., B. intermedius and B. bivius, were found to have a significant frequency of beta-lactamase production. Substrate profile and sensitivity to the beta-lactamase inhibitors, sulbactam, clavulanic acid, cloxacillin, and cefmetazole, a cephamycin derivative, were determined for these enzymes. All enzymes hydrolyzed cephalosporins more rapidly than penicillins. Cefmetazole was not hydrolyzed at all. Strains of B. fragilis, B. thetaiotaomicron, B. uniformis, B. ovatus and B. oralis produced beta-lactamases sensitive to all four inhibitors. Strains of B. intermedius, B. bivius and B. disiens produced enzymes of different nature which were inhibited only by cefmetazole. B. vulgatus enzyme was inhibited by three of the four inhibitors. These results suggest that the beta-lactamases of the genus Bacteroides may be classified by substrate profile and inhibitor pattern.

Bacteroides↗
PubMed1982

[In vitro and in vivo antimicrobial activities of cefmetazole against Bacteroides fragilis].

Cefmetazole was investigated on stability to beta-lactamases produced by Bacteroides fragilis and on therapeutic effects in mice infected with B. fragilis. 1. Cefmetazole, like other cephamycins, was found extremely stable to beta-lactamases obtained from B. fragilis. 2. Cefmetazole showed good antimicrobial activities to 50 strains of B. fragilis and extremely high stability to their beta-lactamases. 3. Cefmetazole showed an excellent protecting effect to infections due to beta-lactamase producing B. fragilis. 4. Cefmetazole exhibited an excellent chemotherapeutic effect against polymicrobial infections in mice due to E. coli (beta-lactamase -)and B. fragilis (beta-lactamase +).

Animals↗
PubMed1975

[Effects of hyper-and hypothyroidism on central nervous system with special reference to its effects on rectal temperature and brain norepinephrine levels in rats].

Infleunce of hyper-and hypothyroidism on amphetamine activity was observed by measuring the effects on hyperthermia and brain amphetamine and norepinephrine levels. Hyperthyroidism was obtained in rats injected with tri-iodothyronine 0.2 mg/kg i.p. every day for 5 days. Controls were treated with the vehicle 1.0 ml/kg i.p. for the same period. On the 6th day, d-amphetamine (10 mg/kg i.p.) was administered to the two groups of animals and the body temperature and brain amphetamine and norepinephrine contents were measured at 0 min, 15 min, 30 min and 60 min. Hyperthyroid rats showed a more marked hyperthermia than did the control animals. On the other hand "amphetamine-induced release of norepinephrine" of hyperthyroid rats was not so marked as in the control rats, however amphetamine levels did not differ in the two groups. Hypothyroidism was evident in the thyroidectomized rats. Controls for this group underwent a sham-operation. All animals were injected with amphetamine 21 days later. Amphetamine did not cause a hyperthermia in thyroidectomized rats. On the other hand, amphetamine levels were considerably higher than in the control rats, but the degree of norepinephrine release was comparable in the two groups.

Amphetamine↗
PubMedDate not supplied

Effects of bucillamine and antigen-presenting cells in experimental autoimmune uveitis in rats.

Bucillamine, an anti-rheumatic drug, was compared with cyclosporine (CYA) in its effects on the antigen-presentation activity of antigen-presenting cells (APCs) and the antigen-specific proliferation of T cells from S-antigen-immunized rats. In vitro assay showed that bucillamine did not affect the proliferative response of T cells, but suppressed the antigen-presenting activity of APCs, such as macrophages and retinal pigment epithelial cells. On the other hand, CYA suppressed both T cell proliferation and the antigen-presenting activity of macrophages. However, the doses of CYA required to produce significant suppression of antigen presentation were higher than those needed to inhibit T cell proliferation. Daily systemic administration of bucillamine for 14 days after immunizing rats with S-antigen suppressed the intensity of experimental autoimmune uveitis (EAU) and the antigen-presenting activity of macrophages in treated rats, but not the antigen-specific proliferation of the T cells. EAU intensity was completely suppressed by CYA for 14 days post-immunization, and antigen-specific proliferation of T cells was suppressed, but the antigen-presenting activity of macrophages was not affected. These results suggested that the suppressive effects of bucillamine on the antigen-presenting activity of APCs contributed to its suppressive effects on EAU; whereas, the suppressive effects of CYA on EAU resulted principally from its suppression of the T-cell function.

Animals↗