Aligarh Muslim University

About: Aligarh Muslim University is a education organization based out in Aligarh, Uttar Pradesh, India. It is known for research contribution in the topics: Population & Adsorption. The organization has 8218 authors who have published 16416 publications receiving 289068 citations. The organization is also known as: AMU.

DNA damage and mutagenicity induced by endosulfan and its metabolites.

Abstract: Endosulfan is a widely used broad-spectrum organochlorine pesticide, which acts as a contact and stomach poison. Nontarget species, such as cattle, fish, birds, and even humans, are also affected. Studies on the genotoxicity and mutagenicity of endosulfan have been inconsistent and nothing is known about the genotoxicity of its metabolites. In the present study, endosulfan (as a commercial isomeric mixture and as the alpha- and beta-isomers), and metabolites of endosulfan (the sulfate, lactone, ether, hydroxyether, and diol derivatives) were assayed for their ability to induce DNA damage in Chinese hamster ovary (CHO) cells and human lymphocytes using the Comet assay and were assayed for their mutagenicity using the Salmonella reversion assay (Ames test with TA98, TA97a, TA102, TA104, and TA100, with and without S9 activation). The compounds produced statistically significant (P < 0.01), concentration-dependent (0.25-10 microM) increases in DNA damage in both CHO cells and human lymphocytes. Endosulfan lactone caused the most DNA damage in CHO cells, while the isomeric mixture of endosulfan produced the greatest response in lymphocytes. The test compounds also were mutagenic in Salmonella strains at concentrations of 1-20 mug/plate (P < 0.05), with TA98 being the most sensitive strain and the diol and hydroxyether metabolites producing the highest responses. The results indicate that exposure to sublethal doses of endosulfan and its metabolites induces DNA damage and mutation. The contribution of the metabolites to the genotoxicity of the parent compound in Salmonella and mammalian cells, however, is unclear, and the pathways leading to bacterial mutation and mammalian cell DNA damage appear to differ.

Effects of solvent media and temperature on the self-aggregation of cationic dimeric surfactant 14-6-14, 2Br- studied by conductometric and fluorescence techniques.

Abstract: To explore how the solvent characteristics influence the self-aggregation of the cationic dimeric surfactant hexamethylene-1,6-bis(tetradecyldimethylammonium bromide) (14-6-14, 2Br(-)) and to obtain various energetic parameters, conductometric experiments were performed on the binary mixtures of three organic solvents--viz., 2-methoxyethanol (ME)-, acetonitrile (AN)-, and formamide (FA)- water (WR) at different temperatures ranging from 298.15 to 323.15 K. The steady state fluorescence measurements allowed us to calculate the average aggregation number (N(agg)) and the air-bulk phase surface tension helped us to correlate the solvent cohesive energy density with Gibbs energy of micellization (DeltaG(0)(m)). The results showed that, although micellization process becomes less favorable with the increase in volume % of the ME, AN and FA in the binary mixed media, the increment in the cmc below 20% (v/v) of the organic solvents is comparatively less showing the predominance of WR character in the bulk phase. Because of the decrease in Gibbs interfacial energy contribution (DeltaG(0)(interf)) to DeltaG(0)(m), the average aggregation number (N(agg)) decreased with the increase in the volume % of the organic solvent in the mixed media. As the enthalpy of micellization became more negative, the corresponding entropy change became less positive and enthalpy-entropy compensation phenomenon was observed for the micellization of 14-6-14, 2Br(-) in all the mixed media in the studied temperature range.