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Introduction: Epidemiological studies indicate that obesity is associated with an increased risk of 20-25% with several types of cancer., Objective: The frequency of chromosome aberrations was evaluated in lymphocytes from postmenopausal obese and non-obese women., Materials and Methods: Twenty obese and 20 non-obese women, all post-menopause, were recruited. The groups were matched according to age (± 5 years) and place of origin. After signing the consent form, women were interviewed using a structured questionnaire, and a blood sample (5 ml) was drawn into vacutainer tubes. From each sample, lymphocyte cell cultures were established with and without mitomycin C (challenge assay). Afterwards, the frequency of chromosome aberrations were recorded for each group and treatment. Data were analyzed using the statistical program SPSS, v. 14.0., Results: Obese women had a higher frequency of chromosome aberrations when compared with non-obese women. After exposing the cell cultures to mitomycin C, obese women presented an increase in the number of total chromosome aberrations in comparison to non-obese women (3.7± 0.6 vs. 2.70±0.6; p=0.001)., Conclusions: The higher frequency of chromosome aberrations in lymphocytes from postmenopausal obese women compared to non-obese women suggested differences in the DNA repair capacity. This may indicate an association between genomic instability and the higher incidence of cancer in this population.

Introduction: Mutagens contained in complex mixtures can present synergistic interactions, either additive or antagonistic. Therefore, development of experimental approaches is necessary to elucidate which is the responsible agent for the effect in the mixtures., Objective: An experimental design was developed that allowed an understanding of the processes between the compounds of complex mixtures., Materials and Methods: Human lymphocytes were exposed to binary mixtures of the mutagens B[a]P, DMBA, Trp-P-1 and MX for 1 hour with or without S9. Viability was assessed with trypan blue dye and the genotoxicity by the comet assay., Results: All of the hydrocarbon showed an effect with furanone. With and without S9, the most toxic interactions were observed between hydrocarbons. Synergistic interaction was observed without S9 between B [a] P and Trp-P-1 and between DMBA and Trp-P-1 with metabolic activity. Without S9 antagonistic interaction was observed only between Trp-P-1+DMBA, and with S9 between Trp-P-1+MX and MX+DMBA. It observed an increase dose dependent in tail length. Half the cultures showed genotoxic damage and increased cell damage. For each mixture, minimum concentrations were determined at which adverse effects are observed; for some only the maximum concentration was determined at which no adverse effects are observed., Conclusion: The processes between mutagens present in a mixture have become better understood, and the results validated an analytical model that determined which component had an effect on another. The results also showed that the type of compounds in the mixture determined whether or not a risk threshold was present.

Purpose: To study the pig retinal ganglion cell (RGC) survival in culture, analysing the possible neuroprotective effect of retinal Müller glia (RMG) and brain-derived neurotrophic factor (BDNF)., Methods: Adult pig retina were dissociated and cultured under different conditions: 1) on laminin/poly-D-lysine-coated coverslips in chemically defined medium (CDM); 2) on laminin/poly-D-lysine-coated coverslips in CMD supplemented with BDNF; 3) on confluent monolayer cultures of RMG in CDM; 4) on laminin/poly-D-lysine substrate in conditioned medium obtained from RMG. RGCs were identified by immunocytochemistry using antibody against 68 kDa neurofilament and observed under an fluorescent microscope. RGCs were classified on the basis of the size, number and length of neurites, and their survival was assayed for each treatment., Results: Confluent RMG substrates and RMG conditioned medium significantly increased the survival of cultured pig RGC. Moreover these two conditions increased the mean area of RGCs and enhanced neurite growth and elongation. Addition of BDNF to culture medium did not modify survival but increased RGC size, neurite number and neurite length., Conclusions: These findings demonstrate that factor(s) secreted by RMG exert beneficial effects on adult RGC survival and neurite regeneration in vitro, and might constitute important agent(s) for RGC neuroprotection. BDNF also increases the mean area of RGCs and enhances neurite growth but it does not increase the survival of RGCs.