Cytotoxicity and genotoxicity of low doses of mercury chloride and methylmercury chloride on human lymphocytes in vitro

Mercury is a xenobiotic metal that is a highly deleterious environmental pollutant. The biotransformation of mercury chloride (HgCl2) into methylmercury chloride (CH3HgCl) in aquatic environments is well-known and humans are exposed by consumption of contaminated fish, shellfish and algae. The objective of the present study was to determine the changes induced in vitro by two mercury compounds (HgCl2 and CH3HgCl) in cultured human lymphocytes. Short-term human leukocyte cultures from 10 healthy donors (5 females and 5 males) were set-up by adding drops of whole blood in complete medium. Cultures were separately and simultaneously treated with low doses (0.1 to 1000 µg/l) of HgCl2 and CH3HgCl and incubated at 37ºC for 48 h. Genotoxicity was assessed by chromosome aberrations and polyploid cells. Mitotic index was used as a measure of cytotoxicity. A significant increase (P < 0.05) in the relative frequency of chromosome aberrations was observed for all concentrations of CH3HgCl when compared to control, whether alone or in an evident sinergistic combination with HgCl2. The frequency of polyploid cells was also significantly increased (P < 0.05) when compared to control after exposure to all concentrations of CH3HgCl alone or in combination with HgCl2. CH3HgCl significantly decreased (P < 0.05) the mitotic index at 100 and 1000 µg/l alone, and at 1, 10, 100, and 1000 µg/l when combined with HgCl2, showing a synergistic cytotoxic effect. Our data showed that low concentrations of CH3HgCl might be cytotoxic/genotoxic. Such effects may indicate early cellular changes with possible biological consequences and should be considered in the preliminary evaluation of the risks of populations exposed in vivo to low doses of mercury

Cytogenetic description of breast fibroadenomas: alterations related solely to proliferation?

Twelve breast fibroadenomas were analyzed cytogenetically and only four were found to have clonal alterations. The presence of chromosomal alterations in fibroadenomas must be the consequence of the proliferating process and must not be related to the etiology of this type of lesion. In contrast, the few fibroadenomas that exhibit chromosomal alterations are likely to be those presenting a risk of neoplastic transformation. Clonal numerical alterations involved chromosomes 8, 18, 19, and 21. Of the chromosomal alterations found in the present study, only monosomy of chromosomes 19 and 21 has been reported in breast fibroadenomas. The loss of chromosome 21 was the most frequent alteration found in our sample. The study of benign proliferations and their comparison with chromosome alterations in their malignant counterparts ought to result in a better understanding of the genes acting on cell proliferation alone, and of the genes that cause these cells to exhibit varied behaviors such as recurrences, spontaneous regression and fast growth

Investigation of single-strand conformational polymorphism of the TP53 gene in women with a family history of breast cancer

Breast cancer in families with germ line mutations in the TP53 gene has been described in the medical literature. Mutation screening for susceptibility genes should allow effective prophylactic and preventive measures. Using single-strand conformational polymorphism, we screened for mutations in exons 5, 6, 7 and 8 of gene TP53 in the peripheral blood of 8 young non-affected members (17 to 36 years old) of families with a history of breast cancer. Studies of this type on young patients (mean age, 25 years) are very rare in the literature. The identification of these mutations would contribute to genetic counseling of members of families with predisposition to breast cancer. The results obtained did not show any polymorphism indicating mutation. In our sample, the familial tumorigenesis is probably related to other gene etiologies

Performance of the visual analogue scale of happiness and of the Cornell scale for depression in dementia in the tremembé epidemiological study, Brazil [Desempenho Na Escala Analógica Visual De Felicidade E Na Escala Cornell De Depressão Em Demência No Estudo Epidemiológico De Tremembé, Brasil]

Made available in DSpace on 2019-09-12T16:26:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2014Depression is a major growing public health problem. Many population studies have found a significant relationship between depression and the presence of cognitive disorders. Objective: To establish the correlation between the Visual Analogue Scale of Happiness and the Cornell Scale for Depression in Dementia in the population aged 60 years or over in the city of Tremembé, state of São Paulo, Brazil. Methods: An epidemiological survey involving home visits was carried out in the city of Tremembé. The sample was randomly selected by drawing 20% of the population aged 60 years or older from each of the city’s census sectors. In this single-phase study, the assessment included clinical history, physical and neurological examination, cognitive evaluation, and application of both the Cornell Scale and the Analogue Scale of Happiness for psychiatric symptoms. The presence of depressive symptoms was defined as scores greater than or equal to 8 points on the Cornell Scale. Results: A total of 623 subjects were evaluated and of these 251 (40.3%) had clinically significant depressive symptoms on the Cornell Scale, with a significant association with female gender (p<0.001) and with lower education (p=0.012). One hundred and thirty-six participants (21.8%) chose the unhappiness faces, with a significant association with age (p<0.001), female gender (p=0.020) and low socioeconomic status (p=0.012). Although there was a statistically significant association on the correlation test, the correlation was not high (rho=0.47).  Conclusion: The prevalence of depressive symptoms was high in this sample and the Visual Analogue Scale of Happiness and Cornell Scale for Depression in Dementia should not be used as similar alternatives for evaluating the presence of depressive symptoms, at least in populations with low educational level. © 2014, Academia Brasileira de Neurologia. All rights reserved.César, K.G., Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, Brazil, University of Taubaté, BrazilBrucki, S.M., Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilTakada, L.T., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilNascimento, L.F.C., University of Taubaté, BrazilGomes, C.M., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilAlmeida, M.C., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilOliveira, M.O., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilPorto, F.H., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilSenaha, M.L., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilBahia, V.S., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilSilva, T.B.L., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilIanof, J.N., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilSpíndola, L., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilSchmidt, M.T., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilJorge, M.S., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilVale, P.H., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilCecchini, M.A., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilCassimiro, L., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilSoares, R.T., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilGonçalves, M.R., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilSmid, J., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilPorto, C.S., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilCarthery-Goulart, M.T., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilYassuda, M.S., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilMansur, L.L., Epidemiologic Study (TES) Group, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, BrazilNitrini, R., University of São Paulo Medical School, Cognitive and Behavioral Neurology Unit, Department of Neurology, University of São Paulo, Brazi