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Biomedical subjects

S K Bose

Publications and source records attributed to S K Bose.

At least 109 records · Page 6Linked to original sources

Requirement for cellular protein synthesis in reversal of ethidium-bormide-induced inhibition of cell transformation by murine sarcoma virus.

Cultures of mouse Balb 3T3 fibroblasts exposed to a noncytotoxic dose of ethidium bromide for 16-18 hr are unable to produce foci after infection with murine sarcoma virus. Such cultures regain susceptibility to infection when incubated for 6-8 hr in drug-free growth medium. Pretreated but not untreated cultures exhibit sensitivity toward brief (6 hr) exposure to cycloheximide, chloramphenicol, and actinomycin D before infection. Pretreatment with cordy-cepin inhibits the ability of cultures to produce foci after infection. The recovery of ethidium-bromide-treated cultures requires the synthesis of cellular proteins which may have some important role in the establishment of RNA tumor virus infection.

Cell Line↗

Evaluation of mycobacillin and versicolin as agricultural fungicides. I. Antifungal spectrum and phytotoxicity.

Two antifungal antibiotics, mycobacillin and versicolin, were studied as agricultural fungicides in the control of fungal infection of rice and jute. Mycobacillin is especially active against Piricularia oryzae at a concentration of 10 mug/ml, and versicolin against Colletotrichum gloeosporioides at a concentration of 2.5 mug/ml. Mycobacillin has no adverse effect on germination of seeds and growth of seedlings of rice and jute plants as a concentration of 500ppm, even for prolonged exposure. (24 or 48 hours); in fact, it is stimulatory. On the other hand, versicolin has showed detectable phytotoxicity at 500ppm for prolonged exposure

Antifungal Agents↗

Stereoconfiguration of amino acids in peptides from a mycobacillin-synthesizing cell-free system.

The stereoconfiguration of amino acids, as determined by treatment with L-amino acid oxidase, d-amino acid oxidase and l-glutamate decarboxylase (containing l-aspartate decarboxylase activity), in the peptides from a mycobacillin-synthesizing cell-free system is identical with that of the growing mycobacillin peptide chaid if its synthesis starts from l-proline and is interrupted at various points by amino acid deprivation.

Amino Acid Oxidoreductases↗

Growth-and density-dependent inhibition of deoxyglucose transport in Balb 3T3 cells and its absence in cells transformed by murine sarcoma virus.

The earliest measurable parameter that shows density-dependent inhibition is the uptake of [(3)H]deoxyglucose by Balb 3T3 cells. The rate decreases even during the exponential phase of growth and reaches a minimum, about 8- to 10-times lower than maximum, as the culture approaches the saturation density. Cells transformed by murine sarcoma virus fail to show either growth-dependent or density-dependent inhibition of deoxyglucose uptake. Treatment with dibutyryl cyclic AMP in the presence of theophylline results in premature cessation of growth and in an arrest in the decline of deoxyglucose transport. Culture in serum-deficient medium also produces rapid inhibition of growth at low cell density, but these cultures exhibit a markedly decreased rate of deoxyglucose uptake.

Animals↗

Peptides from a mycobacillin-synthesizing cell-free system.

In a cell-free system from Bacillus subtilis B(3), ATP-P(i) exchange was catalysed by l-proline at a pH optimum of 7.2. Further stimulation by component amino acids of mycobacillin was inhibited by deprivation from the synthesizing system of even a single amino acid occurring at any point of the cyclic peptide. This inhibition, however, decreased with the distance in the molecule of the given amino acid from l-proline. Peptides containing respectively two, three, four, five and six amino acids were isolated from the mycobacillin-synthesizing system by an amino acid-deprivation technique. The amino acid composition of these peptides and also their N- and C-terminal amino acid residues were the same as those of peptides that would be obtained if mycobacillin synthesis occurred starting from l-proline and was interrupted at various points along the polypeptide chain.

Adenosine Triphosphate↗