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OBJECTIVE: The aim of this study was to investigate the influence of smoking on the methylation and hydroxymethylation status of global DNA and specific sites of KRT14, KRT19, miR-9-3 and miR-137 genes in the healthy oral mucosa. METHODS: Samples of oral epithelial cells were collected using mouthwash from a population of former and current smokers and those who had never smoked. Genomic DNA was extracted, and global DNA methylation and hydroxymethylation was performed using an ELISA-based technique; DNA methylation at specific sites was performed using Methylation-Specific PCR (MSP) (KRT14, miR-9-3 and miR-137) or Methylation-Sensitive Restriction Enzymes (MSRE) (KRT19). K14 and K19 protein expression was analysed by immunohistochemistry. RESULTS: Higher levels of global DNA methylation were found in current smokers with over 15 years of consumption (p=0.04), but no differences were found in relation to global DNA hydroxymethylation. No differences in global DNA methylation and hydroxymethylation levels were found in relation to age or gender. Global DNA methylation was higher than the hydroxymethylation level (p<0.001) but they were not correlated in the oral mucosa. For specific sites, miR-9-3 hypomethylation was detected in current smokers (p<0.001). Additional analysis showed no difference in the methylation status when age, gender, period of consumption or amount of cigarettes were considered for any of the studied genes. K19 expression was higher in current smokers in comparison to former smokers and those who had never smoked (p<0.05). CONCLUSION: We concluded that smoking habits were capable of inducing changes in global DNA methylation, miR-9-3 methylation status and K19 expression.

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The objective of this study was to quantify argyrophillic, argentaffin and insulin immunoreactive endocrine cells in the different segments of the small intestine of Didelphis aurita and measure probable differences in the number of these cells between adult and post-pubertal animals. Biological material consisted of ten male and female opossums specimen, divided in two groups according to weigh. The utilized staining techniques were Grimelius, modified Masson-Fontana and direct immunoperoxidase. Results indicated a predominance of argyrophillic cells in the small intestine of opossums from class 1 and 2, with an average of 52.58 and 56.15 cells mm-2, respectively; of which, the average number of total endocrine cells, argyrophillic and argentaffin cells decreased distally in the intestinal segments of opossums from classes 1 and 2. No significant difference was observed for the insulin immunoreactive cells between the intestinal segments of animals from class 2. A greater number of insulin immunoreactive cells was encountered in the jejunum and ileum of animals from class 2 when compared to the same segment in animals from class 1.

Os objetivos deste trabalho foram quantificar as células endócrinas argirófilas, argentafins e imunorreativas à insulina nos diferentes segmentos do intestino delgado de gambás Didelphis aurita e mensurar prováveis diferenças no número destas células entre animais adultos e pós-púberes. Dez exemplares de gambás D. aurita machos e fêmeas foram divididos em dois grupos de acordo com o peso. As técnicas de coloração utilizadas foram Grimelius, Masson-Fontana modificado e Imunoperoxidase direta. Os resultados indicaram um predomínio das células argirófilas no intestino delgado de gambás da classe 1 e 2, com uma média de 52,58 e 56,15 células mm-2, respectivamente. O número médio de células endócrinas totais, células argirófilas e argentafins decresceu distalmente nos segmentos intestinais dos gambás das classes 1 e 2. Nenhuma diferença significativa foi observada para as células imunorreativas à insulina entre os segmentos intestinais dos animais da classe 2. Foi encontrado maior número de células imunorreativas à insulina no jejuno e íleo de animais da classe 2 quando comparado ao mesmo segmento em animais da classe 1.

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Fêmeas ingurgitadas e parcialmente ingurgitadas de B. microplus foram expostas a 600, 3000, 6000 e 30000 juvenis infectivos de Steinernema carpocapsae Weiser, 1955 linhagens Santa Rosa e ALL por placa, sob condições de laboratório. Foram investigados para fêmeas ingurgitadas: peso da massa de ovos, período pré-postura, período de postura, tempo de sobrevivência, índice de eficiência reprodutiva, percentual de aclosão de larvas e concentrações letais 50% e 90% (CL50 e CL90). Para fêmeas parcialmente ingurgitadas somente foram observados peso da massa de ovos, tempo de sobrevivência, CL50 e CL90. Todos os parâmetros biológicos de fêmeas ingurgitadas foram e parcialmente ingurgitadas foram alterados pela exposição a juvenis infectivos de S. carpocapsae linhagens Santa Rosa e ALL (P<0,05). O aumento das resposta foi diretamente proporcional ao aumento das concentrações de juvenis infectivos por placa (P<0,05). Os resultados sugerem que nematóides entomopatogênicos podem ter papel primissor no controle de carrapatos dos bovinos.