Cellular repair enzymes remove virtually all DNA damage before it is fixed; repair therefore plays a crucial role in preventing cancer. Repair studied at the level of transcription correlates poorly ...with enzyme activity, and so assays of phenotype are needed. In a biochemical approach, substrate nucleoids containing specific DNA lesions are incubated with cell extract; repair enzymes in the extract induce breaks at damage sites; and the breaks are measured with the comet assay. The nature of the substrate lesions defines the repair pathway to be studied. This in vitro DNA repair assay has been modified for use in animal tissues, specifically to study the effects of aging and nutritional intervention on repair. Recently, the assay was applied to different strains of Drosophila melanogaster proficient and deficient in DNA repair. Most applications of the repair assay have been in human biomonitoring. Individual DNA repair activity may be a marker of cancer susceptibility; alternatively, high repair activity may result from induction of repair enzymes by exposure to DNA-damaging agents. Studies to date have examined effects of environment, nutrition, lifestyle, and occupation, in addition to clinical investigations.
Introduction: The possibility of resveratrol electrochemical determination, assisted by cobalt (III) oxyhydroxide and its composites with conducting polymers has been evaluated from the theoretical ...point of view. Methodology: The correspondent mathematical model has been developed and analyzed by means of the linear stability theory and bifurcation analysis. Results: The analysis of the model confirms that the cobalto oxyhydroxide may serve as an efficient electrode modifier for resveratrol electroanalytical determination. Conclusion: Depending on the analysis conditions, the electroanalytical process may be either diffusion- or kinetically controlled. On the other hand, the oscillatory behavior is also possible being even more probable than in the simplest cases, due to the impact of the chemical and electrochemical stages on DEL.
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