Renée S Marshall

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The mechanism of aerobic resistance to the quinone-containing anti-tumour agents mitomycin C (MMC) and porfiromycin (PM) has been investigated using non-transformed human cells. One of the cell strains used (3437T) was derived from an afflicted member of a cancer-prone family. This cell strain had been shown previously to be six times more resistant to the(More)
To compare the toxicity of seven N-methyl carbamates, time course profiles for brain and red blood cell (RBC) cholinesterase (ChE) inhibition were established for each. Adult, male, Long Evans rats (n=4-5 dose group) were dosed orally with either carbaryl (30 mg/kg in corn oil); carbofuran (0.5 mg/kg in corn oil); formetanate HCl (10 mg/kg in water);(More)
The presence of low levels of oxygen may have profound effects on the cytotoxic activity of radiation, radiosensitizers, and bioreductive alkylating agents. As others have shown, low oxygen tensions may significantly alter rates of cellular and chemical oxygen consumption. When experiments are performed at very low oxygen concentrations, the opposing(More)
The cellular and molecular damage produced by mitomycin C (MMC) in Chinese hamster ovary cells, AA8-4, and a repair deficient mutant of this line, UV-20, was studied by utilizing a system in which oxygen levels could be altered and monitored in solution during acute drug exposures. The cytotoxic activity of MMC decreased from hypoxic conditions to 1% oxygen(More)
Some factors affecting the cytotoxicity of porfiromycin (PM), an analogue of mitomycin C (MMC), were investigated in suspension cultures of wild-type (AA8-4) and repair-deficient (UV-20) Chinese hamster ovary cells. Oxygen was an important modulator of PM toxicity in AA8-4 cells. The aerobic toxicity was significantly less, and toxicity under extremely(More)
Non-transformed skin fibroblasts derived from five members of a cancer-prone family and three unrelated healthy volunteers were assayed for their levels of activity of the quinone reductase DT-diaphorase and for their sensitivity to the antitumor quinone mitomycin C (MMC). Previous studies of skin fibroblasts derived from one afflicted member of this family(More)
While the cholinesterase-inhibiting N-methyl carbamate pesticides have been widely used, there are few studies evaluating direct functional and biochemical consequences of exposure. In the present study of the acute toxicity of seven N-methyl carbamate pesticides, we evaluated the dose-response profiles of cholinesterase (ChE) inhibition in brain and(More)
The accepted mechanism of toxicity of many organophosphorous and carbamate insecticides is inhibition of acetylcholinesterase activity. In mammals, part of the toxicity assessment usually includes monitoring blood and/or brain acetylcholinesterase inhibition. Other tissues, however, contain cholinesterase activity (i.e. acetyl- and butyryl-cholinesterase),(More)
This article describes the process of establishing a Web site as part of a collaborative project using visual art to promote breast health education. The need for a more "user-friendly" comprehensive breast health Web site that is aesthetically rewarding was identified after an analysis of current Web sites available through the World Wide Web. Two(More)
This study aimed to model long-term subtoxic human exposure to an organophosphorus pesticide, chlorpyrifos, and to examine the influence of that exposure on the response to intermittent high-dose acute challenges. Adult Long-Evans male rats were maintained at 350 g body weight by limited access to a chlorpyrifos-containing diet to produce an intake of 0, 1,(More)