Oxidative stress and immunologic responses following a dietary exposure to PAHs in Mya arenaria

<p>Abstract</p> <p>Background</p> <p>The aim of this research was to investigate oxidative stress and immune responses following a dietary polycyclic aromatic hydrocarbon (PAH) exposure in a marine bioindicator organism, the soft shell clam, <it>Mya arenaria</it>. Immune parameters in hemolymph (haemocyte number, efficiency of phagocytosis and haemocyte activity) and assessment of oxidative stress using catalase (CAT) activity and levels of malondialdehyde (MDA) performed on the digestive gland were estimated as biomarkers in clams fed in mesocosm with PAH contaminated phytoplankton. MDA levels and CAT activities were also measured <it>in situ </it>in organisms sampled in a control site (Metis Beach, Québec, Canada) as well as organisms sampled in a site receiving domestic effluents (Pointe-au-Père, Québec, Canada), to assess effects of abiotic variables related to seasonal variations and mixed contamination on the selected parameters.</p> <p>Results</p> <p>Results on immune parameters suggest that the PAHs may interfere with the maturation and/or differentiation processes of haemocytes. MDA results showed that lipid peroxidation did not occur following the exposure. The levels of CAT activity corresponded to weak antioxidant activity (no significant differences). Recovery was noted for all the immune endpoints at the end of the experiment.</p> <p>Conclusion</p> <p>Results suggest that immune parameters are early biomarkers that can efficiently detect a physiological change during a short term exposure to low concentrations of PAHs. The <it>in situ </it>survey (in the natural environment) suggested that clams from the Pointe-au-Père site did not show any oxidative stress as well as the clams contaminated in mesocosm, probably due to the low concentrations of PAHs used for this study. MDA levels increased however in organisms from Metis Beach, a response probably related to domestic effluents or parasitism.</p

Notificação compulsória da cisticercose em Ribeirão Preto - SP Compulsory notification of cysticercosis in Ribeirão Preto - SP, Brazil

A cisticercose é grave problema de saúde pública em várias regiões da Ásia, África e América Latina. Os estudos epidemiológicos baseados na freqüência de casos nos serviços especializados de neurologia, neurocirurgia, tomografia computadorizada, nas necrópsias e nos estudos soroepidemiológicos não permitem a avaliação da real prevalência populacional. O presente estudo teve como objetivo a análise da prevalência da cisticercose no município de Ribeirão Preto, através da notificação compulsória implantada em caráter pioneiro no Brasil. O coeficiente de prevalência foi de 54 casos/100000 habitantes, no período de 20-outubro-1992 a 31-de-dezembro de 199S. Os resultados indicaram, adicionalmente, que a cisticercose não está sob controle no nosso meio pois 21% dos casos notificados apresentavam a forma ativa. A notificação compulsória revelou ser recurso valioso para o estudo epidemiológico da cisticercose, permitindo, adicionalmente, o mapeamento das áreas mais afetadas para melhor direcionamento das estratégias de prevenção.<br>Cysticercosis is a severe public health problem in several regions of Asia, Africa and Latin America. Epidemiologic studies based on the frequency of cases observed in specialized neurology, neurosurgery and computed tomography services, at autopsy and in seroepidemiologic studies do not permit the determination of the true prevalence of the disease in the population. The objective of the present study was to investigate the prevalence of cysticercosis by compulsory notification. The coefficient of prevalence was 54 cases/100000 inhabitants in the municipality of Ribeirão Preto. The results also indicated that cysticercosis is not under control in our region since 21% of cases presented the active form of the disease. Compulsory notification proved to be a valuable resource for the epidemiologic study of cysticercosis, also permitting the mapping of more affected areas for a better direction of prevention strategies