Glutathione S-transferase M1 (GSTM1) polymorphism in two Brazilian populations

A distribuição das freqüências fenotípicas do gene GSTM1 de duas amostras brasileiras, compostas de doadores sanguíneos de ambos os sexos com idade entre 18 e 61 anos, foi estudada. A primeira amostra é composta de 658 indivíduos provenientes do Rio de Janeiro e a segunda de 179 indivíduos de Brasília. Os fenótipos da GSTM1 foram determinados utilizando-se a técnica da reação em cadeia da polimerase e subsequente digestão com a enzima de restrição HaeII. As freqüências observadas para o fenótipo GSTM1 nulo foram de 46,4% e 48,6% para as amostras do Rio de Janeiro e Brasília, respectivamente. Os resultados também mostram que a distribuição fenotípica da GSTM1 não está em equilíbrio de Hardy-Weinberg para ambas as amostras: χ2 1 = 11,49 (P < 0,001) para o Rio de Janeiro e χ2 1 = 6,77 (P < 0,01) para Brasília. Este desequilíbrio pode ser atribuído a fatores como seleção, erros na determinação fenotípica ou panmixia ainda incompleta da população brasileira, cujos componentes raciais são caucasóides, africanos e índios.The distribution of GSTM1 phenotype frequencies was studied in two Brazilian samples composed of healthy and unrelated blood donors of both sexes ranging in age from 18 to 61 years. The first sample consisted of 658 individuals from Rio de Janeiro, and the second included 179 individuals from Brasília. The GSTM1 phenotypes were detected using PCR reactions and subsequent digestion by the restriction enzyme HaeII. The GSTM1 null phenotype frequency was 46% and 49% for Rio de Janeiro and Brasília samples, respectively. The GSTM1 phenotype distributions were not in agreement with Hardy-Weinberg equilibrium in either sample, c21 = 11.49 (P < 0.001) for Rio de Janeiro and c21 = 6.77 (P < 0.01) for Brasília. This deviation from Hardy-Weinberg equilibrium may be due to factors such as selection, errors in the phenotype determination or incomplete panmixia of the Brazilian population, whose main racial components are Caucasians, Africans and Indians

Superoxide dismutase, catalase, glutathione peroxidase and gluthatione S-transferases M1 and T1 gene polymorphisms in three Brazilian population groups

Antioxidants such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX1) reduce the oxidation rates in the organism. Gluthatione S-transferases (GSTs) play a vital role in phase 2 of biotransformation of many substances. Variation in the expression of these enzymes suggests individual differences for the degree of antioxidant protection and geographical differences in the distribution of these variants. We described the distribution frequency of CAT (21A/T), SOD2 (Ala9Val), GPX1 (Pro198Leu), GSTM1 and GSTT1 polymorphisms in three Brazilian population groups: Kayabi Amerindians (n = 60), Kalunga Afro-descendants (n = 72), and an urban mixed population from Federal District (n = 162). Frequencies of the variants observed in Kalunga (18% to 58%) and Federal District (33% to 63%) were similar to those observed in Euro and Afro-descendants, while in Kayabi (3% to 68%), depending on the marker, frequencies were similar to the ones found in different ethnic groups. Except for SOD2 in all population groups studied here, and for GPX1 in Kalunga, the genotypic distributions were in accordance with Hardy-Weinberg Equilibrium. These data can clarify the contribution of different ethnicities in the formation of mixed populations, such as that of Brazil. Moreover, outcomes will be valuable resources for future functional studies and for genetic studies in specific populations. If these studies are designed to comprehensively explore the role of these genetic polymorphisms in the etiology of human diseases they may help to prevent inconsistent genotype-phenotype associations in pharmacogenetic studies

Distribution of glutathione S-transferase GSTM1 and GSTT1 null phenotypes in Brazilian Amerindians

The distribution of glutathione S-transferase (GST) GSTM1 and GSTT1 null phenotype frequencies in two Brazilian Amerindian tribes, the Munduruku tribe from Missão Cururu village (79 individuals) and the Kayabi tribe (41 individuals), was analyzed by polymerase chain reaction (PCR) amplification. The GST null phenotype frequencies for the Munduruku sample were 0% for GSTM1 and 27% for GSTT1 while for the Kayabi sample the null phenotype frequencies were 27% for GSTM1 and 29% for GSTT1. This is the first report of the absence of the GSTM1 null phenotype in any ethnic group

Genetic polymorphisms and metabolism of endocrine disruptors in cancer susceptibility

Epidemiological studies have estimated that approximately 80% of all cancers are related to environmental factors. Individual cancer susceptibility can be the result of several host factors, including differences in metabolism, DNA repair, altered expression of tumor suppressor genes and proto-oncogenes, and nutritional status. Xenobiotic metabolism is the principal mechanism for maintaining homeostasis during the body's exposure to xenobiotics. The balance of xenobiotic absorption and elimination rates in metabolism can be important in the prevention of DNA damage by chemical carcinogens. Thus the ability to metabolize and eliminate xenobiotics can be considered one of the body's first protective mechanisms. Variability in individual metabolism has been related to the enzymatic polymorphisms involved in activation and detoxification of chemical carcinogens. This paper is a contemporary literature review on genetic polymorphisms involved in the metabolism of endocrine disruptors potentially related to cancer development

Glutathione S-Transferase Ml (GSTMl) and T1 (GSTTl) Polymorphisms in a Brazilian Mixed Population

The GSTM1 and GSTT1 null genotype frequencies were significantly di1ferent between 658 nonblack and black healthy blood donors from a BraziJian mixed population (Rio de Janeiro). The GSTMI phenotype distribution was not in Hardy-Weinberg equilibrium in either group, mainly because of an excess of the GSTM1 *A/*B genotype

Lack of association between glutathione S-transferase polymorphisms and primary glioma in a case-control study in Rio de Janeiro

Submitted by Sandra Infurna ([email protected]) on 2017-10-24T10:01:48Z No. of bitstreams: 1 p_coutinho_etal_IOC_2010.pdf: 207620 bytes, checksum: ba036b16940a11c1dc7194d56796b95b (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2017-10-24T10:10:51Z (GMT) No. of bitstreams: 1 p_coutinho_etal_IOC_2010.pdf: 207620 bytes, checksum: ba036b16940a11c1dc7194d56796b95b (MD5)Made available in DSpace on 2017-10-24T10:10:51Z (GMT). No. of bitstreams: 1 p_coutinho_etal_IOC_2010.pdf: 207620 bytes, checksum: ba036b16940a11c1dc7194d56796b95b (MD5) Previous issue date: 2010Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Genética Humana. Rio de Janeiro, RJ. Brasil.Instituto Nacional de Câncer. Laboratório de Genética Aplicada. Serviço de Hematologia. Rio de Janeiro, RJ, Brasil. / Universidade Federal do Rio de Janeiro. Departamento de Bioquímica Médica. Rio de Janeiro, RJ, Brasil.Instituto Nacional de Câncer. Serviço de Neurocirurgia. Rio de Janeiro, RJ, Brasil.Instituto Nacional de Câncer. Laboratório de Genética Aplicada. Serviço de Hematologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Genética Humana. Rio de Janeiro, RJ. Brasil.The glutathione S-transferases (GSTs), a family of phase II isozymes, detoxify several carcinogens. Genetic variations in GSTs have been associated with increased risk for cancer due to a heritable deficiency in detoxification pathways for environmental carcinogens. Conflicting findings have been reported about the association between constitutive GST polymorphisms and gliomas in different populations. The present case-control study examined 78 patients with primary glioma and 347 controls from Rio de Janeiro. DNA was isolated from whole blood, and four genetic polymorphisms (GSTM1, GSTM3, GSTT1, and GSTP1) were determined by PCR-RFLP. The distributions of the genotypic frequencies of these polymorphisms did not differ significantly between cases and controls and were as expected by Hardy-Weinberg equilibrium (P > 0.05). Risk analysis did not show an association between GSTs and primary glioma, suggesting that these polymorphisms do not influence the risk of primary glioma, at least in this population in Rio de Janeiro, Brazil

Renin-Angiotensin System: is it Possible to Identify Hypertension Susceptibility Genes?

Submitted by Sandra Infurna ([email protected]) on 2018-09-26T15:48:30Z No. of bitstreams: 1 sandroG_lima_etal_IOC_2007.pdf.pdf: 418584 bytes, checksum: 85e9cb3b8b04af12870df68c5f915917 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2018-09-26T16:01:40Z (GMT) No. of bitstreams: 1 sandroG_lima_etal_IOC_2007.pdf.pdf: 418584 bytes, checksum: 85e9cb3b8b04af12870df68c5f915917 (MD5)Made available in DSpace on 2018-09-26T16:01:40Z (GMT). No. of bitstreams: 1 sandroG_lima_etal_IOC_2007.pdf.pdf: 418584 bytes, checksum: 85e9cb3b8b04af12870df68c5f915917 (MD5) Previous issue date: 2007Fundação Oswaldo Cruz. Instituto de Pesquisa Aggeu Magalhães. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto . Instituto Materno Infantil Professor Fernando Figueira. Recife, PE, Brasil.No Brasil, estima-se que 15% a 20% da população adulta urbana sejam acometidos por hipertensão arterial sistêmica (HAS)1,2. Em que pese a inexistência de um estudo de base populacional com representatividade nacional para HAS, indicadores de morbidade e mortalidade por doença cerebrovascular podem mostrar, claramente, a relevância da HAS para a saúde pública brasileira, uma vez que representa um fator de risco com expressiva força de determinação para doenças cardiovasculares3. Em 2004, a doença cerebrovascular foi responsável por 90.930 mortes, sendo a principal causa de mortalidade no Brasil..