Current Search: Carcinogens (x)
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Title
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Comparative study of shark (Carcharinus falciformis) and mammalian (Mesocricetus auratus) cells exposed to chemical carcinogens.
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Creator
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Ritchey, Donna Mae., Florida Atlantic University, Hartmann, James X.
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Abstract/Description
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It is not known by what mechanism members of the subclass Elasmobranchii derive their natural resistance to neoplasia. To determine if this resistance is at the cellular level, cultures of shark (Carcharinus falciformis) cells were exposed to varying concentrations of the chemical carcinogens methanesulfonic acid ethyl ester (EMS) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Treated cells were assayed for cytotoxicity, formation of transformed foci and growth in agarose. It was found that...
Show moreIt is not known by what mechanism members of the subclass Elasmobranchii derive their natural resistance to neoplasia. To determine if this resistance is at the cellular level, cultures of shark (Carcharinus falciformis) cells were exposed to varying concentrations of the chemical carcinogens methanesulfonic acid ethyl ester (EMS) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Treated cells were assayed for cytotoxicity, formation of transformed foci and growth in agarose. It was found that a greater chemical concentration was necessary to reach LC50 in shark cells than in mammalian cells (BHK21 Cl13). Shark cell cultures developed no transformed foci over a range of chemical concentrations of EMS whereas foci formed at all concentrations in BHK control cultures exposed to EMS. Treated shark cells did not develop transformed colonies in agarose, but the mammalian cells readily formed colonies. These results suggest that the natural resistance of elasmobranchs to neoplasia could be partially, if not entirely, regulated at the cellular level.
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Date Issued
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1991
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PURL
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http://purl.flvc.org/fcla/dt/14708
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Subject Headings
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Carcharhinus, Carcinogens, Golden hamster
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Format
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Document (PDF)
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Title
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EFFECT OF N-METHYL-N'-NITRO-N-NITROSOGUANIDINE (MNNG) ON DNA OF CULTURED RAT HEPATOMA CELLS.
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Creator
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JHABVALA, PERSEUS, Florida Atlantic University, Stein, Abraham, Charles E. Schmidt College of Science, Department of Biological Sciences
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Abstract/Description
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The objective of this study was to elucidate the interaction of the carcinogen MNNG with nuclear DNA of Rat Hepatoma cells. The effect of a range of MNNG concentrations on RH cell DNA was studied by an analysis of the DNA fragments obtained in linear alkaline sucrose gradients. A macromolecular analysis of the sedimentation profile for 0.06 mM MNNG (Experiment I), and 0.1 mM MNNG (Experiment III), suggested that the system was paucidisperse and contained at least three components. The major...
Show moreThe objective of this study was to elucidate the interaction of the carcinogen MNNG with nuclear DNA of Rat Hepatoma cells. The effect of a range of MNNG concentrations on RH cell DNA was studied by an analysis of the DNA fragments obtained in linear alkaline sucrose gradients. A macromolecular analysis of the sedimentation profile for 0.06 mM MNNG (Experiment I), and 0.1 mM MNNG (Experiment III), suggested that the system was paucidisperse and contained at least three components. The major component Max 1 has a molecular weight comparable to that known for the mammalian replicon. Max 2 has a molecular weight twice that of Max 1 and Max 3 has a molecular weight half that of Max 1. The size of the replicon is comparable to that obtained by others. Inferences were drawn regarding the structure of chromatin and the role of the distribution of sites hypersensitive to methylation with respect to the oncogenes.
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Date Issued
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1985
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PURL
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http://purl.flvc.org/fcla/dt/14260
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Subject Headings
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Carcinogenicity testing, Cancer--Genetic aspects, DNA
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Format
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Document (PDF)