Browsing by Author "Silva, Ana"
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- Co-exposure to environmental carcinogens in vivo induces neoplasia-related hallmarks in low genotoxicity events, even after removal of insultPublication . Martins, Marta; Silva, Ana; Costa, Maria H.; Miguel, Célia; Costa, Pedro M.Addressing the risk of mixed carcinogens in vivo under environmentally-realistic scenarios is still a challenge. Searching for adequate biomarkers of exposure requires understanding molecular pathways and their connection with neoplasia-related benchmark pathologies. Subjecting the zebrafish model to realistic concentrations of two genotoxicants and carcinogens, cadmium and benzo[a]pyrene, isolated and combined, yielded low levels of DNA damage. Altogether, the organisms' mechanisms of DNA repair, oxidative stress and phases I and II were not overwhelmed after two weeks of treatment. Still, transcriptional responses related to detoxification (epoxide hydrolase and UDP-glucuronosyltransferase) were higher in animals subjected to the combination treatment, inclusively following depuration. Nonetheless, inflammation and formation of hyperplasic foci in fish epithelia were more severe in animals exposed to the combined substances, showing slower recovery during depuration. Additionally, the combination treatment yielded unexpected increased expression of a ras-family oncogene homologue after depuration, with evidence for increased tp53 counter-response in the same period. The findings indicate that oncogene expression, cell proliferation and inflammation, may not require noticeable DNA damage to occur. Furthermore, albeit absent proof for neoplasic growth, the removal of chemical insult may promote tissue recovery but does not entirely clear molecular and histopathological endpoints that are commonly associated to neoplasia.
- Imunidade para o vírus da hepatite A: vigilância de onze anos (2002-2012) numa consulta de medicina das viagens da região centro de PortugalPublication . Passadouro, Rui; Silva, Ana; Rodrigues, Ruben; Pascoal, Dina; Soares, FátimaEm diversos países é crescente a proporção de indivíduos suscetíveis à infeção pelo vírus da hepatite A. O conhecimento da seroprevalência VHA numa população é muito importante para a definição de estratégias de controlo da infeção.
- Maintenance of two-spotted goby, Gobiusculus flavescens (Fabricius, 1779) (Perciformes, Gobiidae), in captivity as a resource for ornamental fishkeepingPublication . Teles, Vera; Silva, Ana; Mendes, Susana; Maranhão, PauloThe survival and growth of semipelagic two-spotted goby (Gobiusculus flavescens) were investigated in the laboratory to appreciate the ability of this species to be kept in captivity as a resource for ornamental fishkeeping. The survival of individuals was tested under three temperatures (23°C, 25°C and 27°C) during 12 days. The growth of individuals was tested using two diets: Diet 1-“SERA ®vipan” + “SERA® discus granulat” and Diet 2-“Mysis and Artemia brine shrimp” (Ocean Nutrition®), at 21°C, during 5 weeks. The low death rate at 23°C (10%) can indicate some potential for this species to be used in ornamental aquariophilia. The diet consisting of Mysis sp. and Artemia sp. brine shrimp (Diet 2) appears to be well accepted be the fishes and promotes a good growth. The two-spotted goby proved to be a species very easy to handle and to maintain at the appropriate temperatures.
- Understanding passion, grit, and mindset in Portuguese undergraduate sport sciences studentsPublication . Frontini, Roberta; Sigmundsson, Hermundur; Silva, Ana; Lima, Ricardo; Clemente, Filipe Manuel