No description available.

Thesis (Ph. D.)--Illinois State University, 1970. / Title from title page screen, viewed Sept. 2, 2004. Dissertation Committee: Herman Brockman, David Pittman (co-chairs), John Frehn, Edwin Willis, David Weber. Includes bibliographical references (leaves 75-82) and abstract. Also available in print.

Thesis (Ph. D.)--Illinois State University, 1970. / Title from title page screen, viewed Sept. 3, 2004. Dissertation Committee: H.E. Brockman (chair), D.D. Pittman, W. Daniel, D. Weber, E.R. Willis. Includes bibliographical references (leaves 89-96) and abstract. Also available in print.

No description available.

Thesis (Ph. D.)--McMaster University (Canada), 1988. / Source: Dissertation Abstracts International, Volume: 62-13, Section: A, page: 0000.

Thesis (M.Sc.) - Carleton University, 2007. / Includes bibliographical references (p. 182-200). Also available in electronic format on the Internet.

Thesis (Ph. D.)--Illinois State University, 1993. / Title from title page screen, viewed March 7, 2006. Dissertation Committee: Herman E. Brockman (chair), Alan J. Katz, Brian J. Wilkinson, David F. Weber, Radheshyam K. Jayaswal. Includes bibliographical references (leaves 162-177) and abstract. Also available in print.

Two aspects of the biological activity of N-nitrosamines were studied. First, the effect of ascorbate on the mutagenicity of N-nitrosopiperidines was studied in the Ames Salmanella/ mammalian microsome mutagenicity test. The addition of ascorbate significantly enhanced the mutagenicity of these compounds. This enhancement was selective for N-nitrosamines suggesting a possible role of ascorbate in N-nitrosamine induced carcinogenicity. Second, the technique of velocity sedimentation in alkaline sucrose density gradients was applied to the detection of N-nitrosamine induced DNA damage in Balb/c 3T3 cells. This technique detected N-nitrosamine induced DNA damage when the cells were made permeable before treatment. This technique compares favorably with other test systems used to evaluate N-nitrosamines and should be useful in further studies of N-nitrosamines.

Orientador: Eliana Aparecida Varanda / Banca: Valéria Valente / Banca: Cleslei Fernando Zanelli / Banca: Fabio Vieira dos Santos / Banca: Raquel Alves dos Santos / Resumo: Atualmente, muitos estudos que envolvem produtos naturais são contínuos e focalizados em descobrir drogas para as mais diversas áreas terapêuticas. Grande parte dos compostos sintéticos presentes no mercado atual tem origem de produtos naturais, em especial de plantas. O nemorosone é o constituinte majoritário da resina floral de Clusia rósea Jacq., Clusiaceae, e da própolis cubana. Estudos in vitro relataram atividade citotóxica dessa substância contra várias linhagens de células tumorais incluindo aquelas resistentes a diversas drogas citostáticas, além de apresentar uma baixa citotoxicidade sobre células não-tumorais. Portanto, visando à caracterização da atividade biológica do nemorosone, uma substância com potencial atividade antitumoral e a importância dos testes de toxicidade para a avaliação da segurança pré-clínica de compostos candidatos a drogas, os objetivos desse trabalho se fundamentaram em estudar a influência do nemorosone sobre danos ao DNA pelo teste do Cometa em células mamárias normais (MCF10A) e tumorais (MCF-7 BUS), assim como a sua atividade mutagênica e antimutagênica por meio do teste de Ames, utilizando diferentes linhagens de Salmonella typhimurium. Além disso, foi caracterizada sua atividade estrogênica e antiestrogênica através do Ensaio de E-Screen, o qual determina o efeito proliferativo da substância em células MCF-7 sensíveis a estrógenos e também pelo modelo experimental que utiliza leveduras recombinantes (Recombinant Yeast Assay). Posteriormente, foi avaliada sua influência sobre o ciclo celular de MCF-7 BUS através de citometria de fluxo e análise de expressão de diferentes genes nessa mesma linhagem celular pela técnica de PCR Array, para a elucidação de possíveis mecanismos de ação do nemorosone, a fim de contribuir para sua recomendação como agente terapêutico... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Currently, a wide range of research involving natural products is focused on the discovery of new drugs in many different therapeutic areas. A great number of the synthetic compounds on the market were derived from natural products, especially plants. Nemorosone is the major constituent of the floral resin of Clusia rosea Jacq., Clusiaceae, and in Cuban propolis. In vitro studies have shown cytotoxic activity in this substance against various tumor cell lines, including those resistant to various cytotoxic drugs, whereas it has low cytotoxicity to non-tumoral cells. Therefore, in order to characterize the biological activity of nemorosone, a substance with potential antitumor activity, and in view of preclinical testing of the toxicity of drug candidate compounds, the aim of this study was to determine the nemorosone capacity to induce DNA damages in normal breast cells (MCF10A) and breast cancer cells (MCF-7 BUS) by Comet Assay, as well as the mutagenic and antimutagenic activity by Ames test. Moreover, to characterize the estrogenic and antiestrogenic activity by E-Screen Assay, wich determines the proliferative effect of the compound in MCF-7 cells sensitive to estrogen and by experimental recombinant yeast model (Recombinant Yeast Assay).Subsequently, nemorosone influence on MCF-7 BUS cell cycle was assessed by flow cytometry analysis and the expression of different genes in the same cell line was evaluated by PCR Array for identification of possible mechanisms of action of the compound, in order to contribute to its recommendation as a therapeutic agent. The nemorosone did not induce damages in normal or cancer breast cells DNA after treatment during 3 and 24 hours, when evaluated by Comet Assay. The compound showed higher citotoxicity to cancer cells than to normal breast cells. In the Ames test, nemorosone presented no mutagenic potencial... (Complete abstract click electronic access below) / Doutor

Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains xvi, 148 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 162-183).