Search PubMed⌕ Search

Biomedical subjects

T Baba

Publications and source records attributed to T Baba.

At least 559 records · Page 31Linked to original sources
PubMed1981

Effects of pH on cytotoxicity of carboquone.

To assess the effects of pH on the cytotoxicity of carboquone (CQ), use was made of the mouse tail skin and HeLa cells in culture. CQ had the most potent cytotoxic effect at pH 6 rather than at pH7 or 8. Regarding the interaction between 14C-CQ and HeLa cells, both the intracellular accumulation of free 14C-CQ and the ratio of bound 14C-CQ to total 14C-CQ uptake were enhanced at pH6. Among the fractionated biomolecules of DNA, RNA and protein, DNA was the most active in binding CQ, under the same conditions of pH. The 14C-CQ binding to nucleic acids at pH 6 was more apparent than was the binding to protein. Thus, the enhancement of CQ cytotoxicity at low pHs is probably due to an increase in the intracellular accumulation of free CQ as well as to an enhanced reactivity of CQ with DNA, within the ranges of a lower pH.

Animals↗
PubMed1981

Protection by sodium thiosulfate and thiourea against lethal toxicity of cis-diamminedichloroplatinum (II) in bacteria and mice.

The protective effect of sodium thiosulfate and thiourea on the lethal toxicity of the antitumor drug, cis-diamminedichloroplatinum (II) (cis-DDP), was investigated in bacteria and mice. Initially, the agents capable of antagonizing bactericidal activity of cis-DDP were screened using WP2 uvra, a strain of E. coli sensitive to this drug. Of the ten sulfur-containing compounds tested, thiourea and sodium thiosulfate exhibited potent protecting effects against cis-DDP cytotoxicity in bacteria. Propylthiouracil and methimazole showed intermediate levels of such protection, but the other 6 compounds had little or no protective effects. Thiourea and sodium thiosulfate were then subjected to the acute lethal toxicity test in mice to assess their protective activity in vivo. We found that cis-DDP i.v. lethality against mice can be blocked almost completely by excess amounts of thiourea or sodium thiosulfate. Thiourea protected against cis-DDP toxicity with a narrow range among the effective doses, while sodium thiosulfate was protective with a remarkably wide range of effective doses. The effectiveness of sodium thiosulfate was also indicated in experiments in which the LD50 dose of cis-DDP (16 mg/kg) i.p. increased over the level of greater than 200 mg/kg with concomitant administration of sodium thiosulfate i.p.

Animals↗
PubMed1981

Effect of bursal perfusate on IgG antibody production in incomplete surgically and hormonally bursectomised chickens.

Bursa of Fabricius tissues of untreated four-week-old and of cyclophosphamide-treated 10-day-old chickens were cultured by a perfusion method and the perfusate used in a study on the enhancement of antibody production and conversion in chickens. The bursal perfusates were given to incompletely immunosuppressed chickens (surgical bursectomy or hormonal bursectomy) and to control chickens which were immunised with either sheep red blood cells or Brucella abortus. The results indicated that bursal perfusate was successful in accelerating the IgM production in surgically bursectomised chickens and in stimulating IgG production. We were able to stimulate IgG production in IgM producing hormonally bursectomised chickens and to shorten the latent period of antibody production against B abortus antigen in normal chickens.

Animals↗