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Biomedical subjects

R L Brahmachary

Publications and source records attributed to R L Brahmachary.

At least 19 recordsLinked to original sources
PubMed1981

Tunicamycin-induced shape transformation in rabbit erythrocytes and loss of adhesion in Limnaea embryonic cells.

The effect of tunicamycin (TM), a nucleoside antibiotic, known to inhibit growth of a number of virus, protozoan and metazoan organisms, presumably by intervening in the glycosylation of glycoproteins, has been studied on Limnaea egg cells and rabbit erythrocytes. TM decreases the adhesion of cells in Limnaea morula and, apparently, induces a high degree of membrane permeability probably leading to the extrusion of cytoplasmic material. The effect of TM is more specific on mature rabbit erythrocytes which have no subcellular structure. TM treatment in vitro alters the normal bioconcave disc-shaped erythrocytes successively into crenated discs, crenated spheres, and smooth spheres. This type of transformation is known to be caused by a number of substances but the present report is the first to indicate a nucleoside-containing compound. This irreversible reaction may be attributed to a structural change of the cellular membrane of erythrocytes.

Animals↗
PubMed1979

Inhibition by cerulenin of RNA and lipid synthesis in Limnaea (mollusc) embryos.

Cerulenin, a new antibiotic known to inhibit lipid synthesis in yeast, fungi and bacterial systems, has been tested with Limnaea embryos. In the presence of 40--50 microgram/ml cerulenin, lipid synthesis is inhibited by about 65% while RNA synthesis is inhibited by about 35% as is evident from the incorporation of 14C-acetate and 14C-uracil, respectively. In embryos treated with cerulenin, washed and returned to normal medium to which 14C-uracil was added, RNA synthesis continued normally. Such pretreatment with actinomycin, however, inhibits lipid synthesis by about 50%. Cerulenin treatment of eggs at the early morula or uncleaved stage for 30 min leads to a marked abnormality at the late veliger stage, and the embryos die before hatching. These results have been discussed in comparison with the known effects of actinomycin. As, unlike actinomycin, cerulenin has no delayed action, the present experiment offers a system for exploring the delayed effects of early transcription.

Animals↗
PubMed1979

Phenylethylamine as a biochemical marker of tiger.

Pheromones of the tiger happen to be a mixture of amines which are "fixed" by lipids. One of these, found always in all the four tigers investigated, is phenylethylamine. This may be a biochemical marker at a species level.

Animals↗