Phototransformation of polycyclic aromatic hydrocarbons into stable, mutagenic components

This report compares the mutagenicity of photochemical products produced by exposure of the polycyclic aromatic hydrocarbons benzo(a)pyrene and 9,10-dimethylanthracene or the aromatic amines 2-aminofluorene, 2-aminoanthracene and 2-aminonaphthalene to sunlight or to ultraviolet light (UVA). 2-Aminofluorene, giving the most active products, was further investigated with respect to the mechanism of photoactivation and the chemical identity of the photochemical products. Screening of HPLC resolved photochemical products demonstrated that the majority of the mutagenicity was localized to one peak - which co-chromatographed with 2-nitrofluorene

Light activation of genotoxic components in natural and synthetic crude oils

Undefined components in natural and synthetically-produced petroleums elicit a genotoxic response in cultured mammalian cells after exposure to light. The NUV component of the solar spectrum is the radiation responsible for photochemical transformation. The type(s) of lesion(s) induced in DNA by the photoactivation process is mimetic of FUV light-induced genotoxic lesions (bulky adduct-like) due to the similar sensitizing abilities of either insult in cells deficient in excision repair. Because of their intimate contact with the oil in the various stages associated with the production of shale oil, process waters contain significant quantities of uv-absorbing organic materials. Chemical fractionation of a process water has been achieved using an acid/base extraction scheme and reverse-phase HPLC. Resulting fractions have been assessed for photo-induced genotoxicity using a modification of the Ames/Salmonella bioassay in which NUV light is the source of activation in place of metabolic enzymes. Chemical identification of components in a photoactive peak fraction is in progress employing an additional class fractionation scheme and GC/MS methods

Decentralization for eductional equity: four case studies from Latin America

Boston University. University Professors Program Senior theses.PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at [email protected]. Thank you.2031-01-0

Cytotoxicity in human skin fibroblasts induced by photoactivated polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAH) require chemical modification in order to exert their mutagenic/carcinogenic activity on biological systems. The mode of activation which has been most extensively studied involves enzyme-catalyzed oxidation reactions but PAH can also be modified into oxidized and radical intermediates upon exposure to various radiations. The resulting products have been shown to be cytotoxic, mutagenic and carcinogenic in a variety of test systems. A number of recent reports have examined the process of sunlight-activation of airborne particles contaminated with PAH. The concern here is the photoactivation of PAH into reactive intermediates which could act directly on target organs such as the skin and lungs. We have been studying the molecular and cellular effects of photoactivated PAH and complex organic mixtures (shale oil byproducts). In this report we present data concerning the cytotoxicity of near ultraviolet light (NUV)-activated PAH in cultured human skin fibroblasts, comparing normal cells with cells obtained from patients with the rare, autosomal recessive disease, xeroderma pigmentosum. In addition, we have quantitated the products of reactions of light-activated benzo(a)pyrene (B(a)P) with DNA in vitro, and have attempted to identify the photoproduct(s) of B(a)P that are important in these reactions

Development of Bacteriphage α: Requirement for the Integrity of One Strand of Parental Deoxyribonucleic Acid

Bacteriophage α- Bacillus megaterium complexes are as sensitive as free phage to the decay of 32 P incorporated in parental phage deoxyribonucleic acid during the eclipse period. </jats:p

Ames/Salmonella mutagenicity assay of natural and synthetic crude oils including a Fischer-Retorted Estonian shale oil

DMSO extracts of a variety of natural and synthetic crude oils were tested for genotoxic activity in the Ames/Salmonella bioassay. Both mutagenic and cytotoxic potentials are cited. Natural crude oils and their refined products and upgraded synfuels are less mutagenic than parent crude shale oils which in turn are less mutagenic than the coal derived distillate blend sample, SRC II. However, this order is not true for cytotoxicity induced by these oil samples; therefore, caution must be exercised in the assessment of their mutagenic potential without consideration of other influential factors including cytotoxicity