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K Ganguly

Publications and source records attributed to K Ganguly.

28 records · Page 2Linked to original sources

Analysis of the interaction between Rauscher murine leukemia virus and murine cell membrane receptor by in vitro binding assay.

Binding of 125I-labeled gp70 of Rauscher murine leukemia virus (R-MuLV) by 3 murine cell lines, BALB/c-3T3, NIH/3T3 and KA-31 (Kirsten murine sarcoma virus transformed clone A-31 of BALB/c-3T3) cells was measured. The binding was a saturable process, dependent on the concentration of gp70 and on the number of cells. In no experiment could we demonstrate any quantitative utilization of gp70 in the medium. However, gp70 remaining in the spent medium could be bound to fresh cells in a subsequent incubation. BALB/c-3T3, NIH/3T3 and KA-31 cells showed similar association constants (1.2-2.5 x 10(8) M-1) for the binding. Moreover, all 3 cell lines had similar number of receptors (7.4-8.9 x 10(5)) per cell. Neither N- and B-tropism of the cells nor transformation by a sarcoma virus altered the number and type of the cell surface receptors.

Animals↗

Cell surface receptors for ecotropic murine viruses are different from those for xenotropic and amphotropic viruses.

The murine cell surface receptor for Rauscher murine leukemia virus was analyzed using a binding assay involving cultured murine cells and 125I-labeled envelope glycoprotein, gp70, of the virus. The binding was competitively inhibited by extracts of ecotropic murine viruses. No inhibition was observed with a xenotropic or an amphotropic murine type-C virus, a murine type-B virus, and several nonmurine retroviruses. Unlike cells producing ecotropic murine viruses, murine cell lines actively producing either an endogenous xenotropic virus or an amphotropic virus showed a significant degree of receptor activity for Rauscher murine leukemia virus gp70. When murine cells were induced with iododeoxyuridine to produce a xenotropic virus and an ecotropic virus in distinct phases, the receptor activity of the induced cells remained unchanged during xenotropic virus release, but a dramatic decrease was evident with the onset of ecotropic virus release. These findings show that ecotropic murine viruses share a common receptor on the murine cell surface and that this receptor is distinct from those for xenotropic and amphotropic murine viruses.

Animals↗

In vitro biological activity of prenylflavanones.

The biological activity of ten prenylflavanones purified from Sophora tomentosa L., and Sophora moorcroftiana Benth. ex Baker (Leguminosae) was investigated. The flavanones with prenyl-, lavandulyl- or geranyl groups on A ring, and two bioactive flavonostilbenes on ring B and stilbene (resveratrol) showed tumor-specific cytotoxic activity, antimicrobial activity, and anti-HIV activity, radical generation, and O2- scavenging activity. There was a positive relationship between radical generation and O2- scavenging activity in these prenylflavanones. These data suggest the medicinal significance of prenylflavanones.

Anti-HIV Agents↗

Antimicrobial activity of prenylflavanones.

Among two flavanones [YS01, YS02] and eight prenylflavanones [YS03-YS10], preliminary screening with fifteen test bacterial strains showed that YS06 was the most active agent. YS06 exhibited highly significant antimicrobial action when tested against 228 bacterial strains comprising two Gram-positive and six Gram-negative genera. The in vitro susceptibility test was carried out by determining the minimum inhibitory concentration (MIC) of YS06 by agar dilution technique. Twenty-two out of fifty strains of Staphylococcus aureus were inhibited at 25 to 50 micrograms/mL of the agent. YS06 also inhibited strains of Salmonella, Shigella and a few strains of Escherichia coli strains were also highly sensitive to YS06, while Kleibsiella spp. and Pseudomonas aeruginosa were much less sensitive. In in vivo study, YS06 offered significant protection (p < 0.001 according to chi-square test) to Swiss albino mice (challenged with 50 minimum lethal dose (MLD, virulent bacterium) at concentrations of 160 and 80 micrograms/mouse.

Anti-Bacterial Agents↗