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S R Bose

Publications and source records attributed to S R Bose.

6 recordsLinked to original sources
PubMed1993

Impact of a 2 MWth research reactor on radioactivity in sediments.

The objective of this study was to determine the environmental impact caused by liquid effluent discharge from the University of Virginia's 2 MWth Research Reactor during the course of its first quarter-century of normal operation. Sediment samples were collected from the reactor pond (situated in a restricted area next to the Reactor Facility), the stream feeding it, and its exit stream. For a comparative study, sediment samples were taken from a nearby closed reference pond having no direct link with the reactor pond. Concentrations of long-lived alpha, beta and gamma emitting radionuclides, from natural and nuclear weapons fallout sources, were detected in pond and stream sediments. Low levels of activation product radioisotopes from the research reactor were detected in the reactor pond sediment. It was observed that both natural and artificial radionuclide concentrations were higher in the UVAR pond (with the exception of 54Mn and 65Zn) as compared to exist stream and reference sediments.

Nuclear Reactors↗
PubMed1987

Protective immunity by chemically modified tumor cell antigens extracted by 3 M KCl.

Tumor antigens from Sarcoma-180 ascites tumor cells were extracted by 3 M KCl before and after treatment with acriflavine. Following dialysis of the extracts against distilled water to remove KCl, the soluble material (antigen) and the precipitate formed during dialysis were collected from the dialysate. Protective immunity of the soluble antigen and the precipitate was evaluated by immunizing mice and subsequent challenge with native tumor cells. It was noted that the soluble antigen and the precipitate of the dialysate obtained from acriflavine-treated tumor cells induced significant protective immunity. The precipitate part appeared to be more effective. Interestingly, similar materials from untreated tumor cells did not show any such protective immunizing efficacy. Antigens extracted by 3 M KCl from chemically modified tumor cells assumed significance in respect to their antitumor immunity.

Acriflavine↗
PubMed1984

Acriflavine-induced surface changes in three tumor cell types and differential sensitivity to lectins.

Phytohemagglutinin (PHA) and concanavalin A (Con A) were used as probes to detect changes in the cell surface of Dalton's lymphoma, sarcoma-180 and Ehrlich's carcinoma after short in vitro exposure to acriflavine. Dye-treated cells showed enhancement of agglutination both by PHA and Con A, and such enhancement was found to be dependent on the time of exposure and concentration of acriflavine. However, PHA-induced percent agglutination seemed to be much higher than that of Con A among the 3 cell types. There were also marked differences among the 3 cell types in order of their sensitivity to lectin-mediated agglutination. The strength of the response was greater in lymphoma to both PHA and Con A than that of sarcoma-180 and carcinoma cells, which appeared to be most resistant. Acriflavine, which is known as an intercalative agent with DNA, induces cell surface changes by promoting lectin-mediated cellular agglutination.

Acriflavine↗
PubMed1984

Chemical transformation of Swiss mouse embryo fibroblasts in primary culture.

Trypsinized secondary cultures of various cell systems have been frequently used by different investigators as models to study, in vitro chemical transformation. In the present study, non-trypsinized primary cultures of fibroblasts derived from fetuses of 14 days gestational age have been used to find out the timings of in vitro chemical transformation by 20-methylcholanthrene and has been designated as PMM-14 cells. These PMM-14 cells have been compared with trypsinized cultures of the same cell systems. The criteria for neoplastic transformation considered in the study involved the appearance of morphological changes, indefinite growth in tissue culture, acquisition of tumorigenic potential in vitro as evidenced by in vivo tests and in vivo latency period for palpable tumor formation. The time span of neoplastic transformation of non-trypsinized embryo fibroblasts in culture was remarkably reduced in comparison with trypsinized cultures of same cell systems. Such discrepancy seems to be due to repeated use of trypsin which may replace many of vital cell surface molecules causing a delay in the expression of carcinogen-induced malignancy. Similarly, repeated subculture before transformation may also have a role in the delayed expression of malignancy.

Animals↗