Fish consumption frequency and lipid peroxidation in the riverside population of Lower Tocantins, Pará / Frecuencia de consumo de pescado y peroxidación lipídica en la población ribereña del Bajo Tocantins, Pará

Introduction: Several studies report the benefits of fish consumption to the prevention of cardiovascular diseases such as atherosclerosis, thrombosis and arrhythmia. On the other hand, regular consumption of fish can induce the accumulation of methylmercury in the body. Objective: To evaluate the relationship between frequency of fish consumption, mercury concentrations and intensity of lipid peroxidation. Methods: A cross - sectional, observational study. It was evaluated riverside in Limoeiro do Ajuru, Pará. Variables were sociodemographic variables, frequency of weekly fish consumption, concentration of total mercury in hair and the dose of malondialdehyde in plasma. The concentrations of total mercury (μg/g) and malondialdehyde (nmol / ml) were respectively 0.63 μg/g and 0.54 nmol/ml for weekly fish consumption less than two meals, 0.51 μg/g 0.42 nmol/ml for consumption in two to four meals and 0.88 μg/g and 0.31 nmol/ml for consumption major than four fish meals. There was a significant difference between groups of two to four and major than four meals, only for the total mercury variable (p = 0.008). Discussion: In this study, low levels exposure and high fish consumption can influencing the bioaccumulation of mercury in this population. Santos et al, found the total mercury concentration (0.09 to 3.79 μg/g) in the rivers and compared the levels according to the intake categories of fish, did not obtain significant statistical difference. This divergent result suggests that deforestation in the Amazon has been increased and is an important vehicle for mercury exposure which affects local survival and subsistence. Conclusion: Riparians in the studied region have high fish consumption and low concentrations of mercury. Although the group with low fish consumption had higher levels of MDA there was no significant difference when compared with other groups

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Human papillomavirus infection and cervical cancer precursor lesions in women living by Amazon rivers: investigation of relations with markers of oxidative stress.

Objective To investigate the relation between oxidative stress markers, human papillomavirus infection and cervical cancer precursor lesions. Methods The study comprised women aged 14 to 60 years living in communities located by Amazon rivers in the state of Pará (Itaituba, Limoeiro do Ajuru and Bragança, 126, 68 and 43 women respectively). Papanicolau smears and polymerase chain reaction tests for human papillomavirus DNA detection were performed. Blood samples were collected to test malondialdehyde, total and oxidized glutathione levels. Results Malondialdehyde, total and oxidized glutathione concentrations did not differ significantly (p>0.05) between women with and without low-grade squamous intraepithelial lesions across communities. Malondialdehyde levels (8.02nmols/mL) were almost five times higher in human papillomavirus-positive compared to human papillomavirus-negative women (1.70nmols/mL) living in Itaituba (statistically significant difference; p<0.05). Malondialdehyde levels did not differ significantly (p>0.05) between human papillomavirus-positive and human papillomavirus-negative women living in remaining communities. Significant (p<0.05) differences in total glutathione levels between human papillomavirus-positive and human papillomavirus-negative women (8.20µg/mL and 1.47µg/mL, respectively) were limited to those living in Bragança. Conclusion Malondialdehyde and total glutathione levels were significantly associated with human papillomavirus infection. However, lack of similar associations with squamous lesions suggest oxidative stress alone does not explain correlations with cervical carcinogenesis. Other factors may therefore be involved.

Human papillomavirus infection and cervical cancer precursor lesions in women living by Amazon rivers: investigation of relations with markers of oxidative stress / Infecção por papilomavírus humano e lesões precursoras do câncer cervicouterino em Ribeirinhas da Amazônia: avaliação da relação com marcadores de estresse oxidativo

ABSTRACT Objective To investigate the relation between oxidative stress markers, human papillomavirus infection and cervical cancer precursor lesions. Methods The study comprised women aged 14 to 60 years living in communities located by Amazon rivers in the state of Pará (Itaituba, Limoeiro do Ajuru and Bragança, 126, 68 and 43 women respectively). Papanicolau smears and polymerase chain reaction tests for human papillomavirus DNA detection were performed. Blood samples were collected to test malondialdehyde, total and oxidized glutathione levels. Results Malondialdehyde, total and oxidized glutathione concentrations did not differ significantly (p>0.05) between women with and without low-grade squamous intraepithelial lesions across communities. Malondialdehyde levels (8.02nmols/mL) were almost five times higher in human papillomavirus-positive compared to human papillomavirus-negative women (1.70nmols/mL) living in Itaituba (statistically significant difference; p<0.05). Malondialdehyde levels did not differ significantly (p>0.05) between human papillomavirus-positive and human papillomavirus-negative women living in remaining communities. Significant (p<0.05) differences in total glutathione levels between human papillomavirus-positive and human papillomavirus-negative women (8.20μg/mL and 1.47μg/mL, respectively) were limited to those living in Bragança. Conclusion Malondialdehyde and total glutathione levels were significantly associated with human papillomavirus infection. However, lack of similar associations with squamous lesions suggest oxidative stress alone does not explain correlations with cervical carcinogenesis. Other factors may therefore be involved.

RESUMO Objetivo Avaliar a relação de marcadores de estresse oxidativo com a infecção pelo papilomavírus humano e as lesões precursoras do câncer cervical. Métodos Foram incluídas mulheres ribeirinhas da Amazônia (a saber: 126 do município de Itaituba, 68 de Limoeiro do Ajuru e 43 de Bragança), todas do Estado do Pará, de 14 a 60 anos. Foram realizados testes Papanicolau e de reação em cadeia de polimerase para a detecção de DNA do papilomavírus humano. Coleta de amostras de sangue foi realizada para a avaliação do malondialdeído e a determinação da glutationa total e oxidada. Resultados As concentrações oxidativas do malondialdeído e os teores de glutationa total e oxidada não apresentaram diferença significativa (p>0,05) nas mulheres com e sem lesão intraepitelial escamosa de baixo grau, em todas as comunidades pesquisadas. Mulheres com papilomavírus humano em Itaituba apresentaram níveis de malondialdeído (8,02nmols/mL) quase cinco vezes maior quando relacionadas àquelas sem o HPV (1,70nmols/mL), com diferença estatística significativa (p<0,05). As outras comunidades não mostraram diferença estatística significativa entre as concentrações de malondialdeído nas mulheres com e sem papilomavírus humano (p>0,05). Os teores de glutationa total mostraram diferença significativa (p<0,05) somente em Bragança naquelas com (8,20µg/mL) e sem a infecção pelo papilomavírus humano (1,47µg/mL). Conclusão Houve associação significativa da resposta oxidativa do malondialdeído e da glutationa total com a infecção pelo papilomavírus humano, porém não houve diferença quando associada à lesão escamosa, sugerindo que o estresse oxidativo isoladamente não explica a relação com a carcinogênese do colo uterino, que deve ser influenciada ainda por outros fatores.