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Reproduction of the exotic bullfrog Lithobates catesbeianus was studied every two months from January 2005 to December 2006, analyzing tadpoles, juveniles, and adult vocalizations at three creeks located in the largest Brazilian center of ornamental fish breeding. Absolute and relative tadpole frequencies were measured bimonthly in three development stages: G1 (no limbs), G2 (hind limbs present), G3 (fore and hind limbs) and I (metamorphs). Results show that, during warmest months, a greater proportion of tadpoles in G1, G2, and G3 phases were found in Santo Antônio and Chato creeks, while G1, G3, and I phases were more common in Gavião creek. Tadpoles in G1 and G2 phases predominated in coldest months at all locations. Male calls and highest average water temperatures and rainfall were recorded at 3 streams during the hottest months. Management measures should be adopted, such as the extermination of larval and adult stages, and initiatives should be taken to prevent new re-introductions, such as: (1) installation of fences around tanks where adults are located, (2) placement of protective screens on the pipes that release waste water from tanks directly into streams, (3) capacity building and educational measures on the problems of biological invasions for staff working on ornamental fish farms. A reprodução da exótica rã-touro Lithobates catesbeianus foi estudada bimestralmente de janeiro a dezembro de 2005 e 2006 analisando-se girinos, imagos e vocalização de adultos em três riachos localizados no município de Vieiras, estado de Minas Gerais, Brasil. Os girinos foram classificados nas fases de desenvolvimento G1 (sem patas), G2 (com patas traseiras), G3 (com patas dianteiras e traseiras), I (imago) e calcularam-se suas frequências absoluta e relativa por bimestre e por riacho. Os resultados mostraram que nos bimestres mais quentes houve maior proporção de girinos G1, G2 e G3 nos riachos Santo Antônio e Chato e G1, G3 e I no riacho Gavião. Girinos nas fases G1 e G2 predominaram nos bimestres mais frios em todos os locais. Vocalizações de machos juntamente com maiores médias de temperatura da água e pluviometria foram registradas nos 3 riachos durante os bimestres mais quentes. Medidas devem ser adotadas para acabar com os animais introduzidos e evitar novas re-introduções na região, tais como: (1) cercar os recintos onde adultos se localizam; (2) colocar telas protetoras nos canos efluentes que liberam água dos tanques diretamente nos riachos, (3) promover esclarecimentos para as pessoas que trabalham nas pisciculturas ornamentais sobre a problemática das invasões biológicas.

Texto completo: acesso restrito. p. 575-582 Submitted by Edileide Reis (leyde-landy@hotmail.com) on 2014-04-15T13:32:29Z No. of bitstreams: 1 Théo Araújo Santos.pdf: 1136176 bytes, checksum: af97d4d5bb6968e2f71f1a300b84d15d (MD5) Approved for entry into archive by Delba Rosa (delba@ufba.br) on 2015-06-10T18:42:43Z (GMT) No. of bitstreams: 1 Théo Araújo Santos.pdf: 1136176 bytes, checksum: af97d4d5bb6968e2f71f1a300b84d15d (MD5) Made available in DSpace on 2015-06-10T18:42:43Z (GMT). No. of bitstreams: 1 Théo Araújo Santos.pdf: 1136176 bytes, checksum: af97d4d5bb6968e2f71f1a300b84d15d (MD5) Previous issue date: 2011 Neutrophils are considered the host's first line of defense against infections and have been implicated in the immunopathogenesis of Leishmaniasis. Leishmania parasites are inoculated alongside vectors' saliva, which is a rich source of pharmacologically active substances that interfere with host immune response. In the present study, we tested the hypothesis that salivary components from Lutzomyia longipalpis, an important vector of visceral Leishmaniasis, enhance neutrophil apoptosis. Murine inflammatory peritoneal neutrophils cultured in the presence of SGS presented increased surface expression of FasL and underwent caspase-dependent and FasL-mediated apoptosis. This proapoptosis effect of SGS on neutrophils was abrogated by pretreatment with protease as well as preincubation with antisaliva antibodies. Furthermore, in the presence of Leishmania chagasi, SGS also increased apoptosis on neutrophils and increased PGE2 release and decreased ROS production by neutrophils, while enhancing parasite viability inside these cells. The increased parasite burden was abrogated by treatment with z-VAD, a pan caspase inhibitor, and NS-398, a COX-2 inhibitor. In the presence of SGS, Leishmania-infected neutrophils produced higher levels of MCP-1 and attracted a high number of macrophages by chemotaxis in vitro assays. Both of these events were abrogated by pretreatment of neutrophils with bindarit, an inhibitor of CCL2/MCP-1 expression. Taken together, our data support the hypothesis that vector salivary proteins trigger caspase-dependent and FasL-mediated apoptosis, thereby favoring Leishmania survival inside neutrophils, which may represent an important mechanism for the establishment of Leishmania infection.

Texto completo: acesso restrito. p. 389-396 Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-11-29T12:28:34Z No. of bitstreams: 1 10.1189jlb.0108018.pdf: 461168 bytes, checksum: d58a0fa4a1b8c4672a4dc606f788780c (MD5) Approved for entry into archive by Alda Lima da Silva (sivalda@ufba.br) on 2013-11-29T19:34:52Z (GMT) No. of bitstreams: 1 10.1189jlb.0108018.pdf: 461168 bytes, checksum: d58a0fa4a1b8c4672a4dc606f788780c (MD5) Made available in DSpace on 2013-11-29T19:34:52Z (GMT). No. of bitstreams: 1 10.1189jlb.0108018.pdf: 461168 bytes, checksum: d58a0fa4a1b8c4672a4dc606f788780c (MD5) Previous issue date: 2008 Neutrophils are involved in the initial steps of most responses to pathogens. In the present study, we evaluated the effects of the interaction of apoptotic vs. necrotic human neutrophils on macrophage infection by Leishmania amazonensis. Phagocytosis of apoptotic, but not viable, neutrophils by Leishmania-infected macrophages led to an increase in parasite burden via a mechanism dependent on TGF-β1 and PGE2. Conversely, infected macrophages’ uptake of necrotic neutrophils induced killing of L. amazonensis. Leishmanicidal activity was dependent on TNF-α and neutrophilic elastase. Nitric oxide was not involved in the killing of parasites, but the interaction of necrotic neutrophils with infected macrophages resulted in high superoxide production, a process reversed by catalase, an inhibitor of reactive oxygen intermediate production. Initial events after Leishmania infection involve interactions with neutrophils; we demonstrate that phagocytosis of these cells in an apoptotic or necrotic stage can influence the outcome of infection, driving either parasite survival or destruction.

Texto em português e inglês Dissertação (mestrado) - Pontifícia Universidade Católica de Minas Gerais, Programa de Pós-Graduação em Zoologia de Vertebrados Inclui bibliografia Resumo: A comunidade de anuros da RPPN Serra do Caraça, localizada no município de Catas Altas (MG), foi estudada no período de agosto de 2003 a outubro de 2004 em oito riachos permanentes de mata. Foram registradas 19 espécies de anuros pertencentes a quatro famílias: Bufonidae (10.53%), Centrolenidae (5.26%), Hylidae (63.16%) e Leptodactylidae (21.05%). Houve uma relação negativa significativa entre o número de espécies presentes e o volume dos riachos. Não houve uma relação entre os fatores abióticos (precipitação e temperatura) e a diversidade de espécies por mês e a diversidade de espécies vocalizando, mas os anuros apresentaram diferenças quanto à distribuição temporal. Das 19 espécies encontradas, 12 apresentaram atividade de vocalização e para 10 espécies foram encontrados indícios de atividade reprodutiva como fêmeas ovadas, pares em amplexos, desovas, girinos e jovens recém metamorfoseados. O tamanho dos riachos parece ser um importante fator determinando a riqueza de espécies de anuros local, a relativa estabilidade climática dos riachos de mata favorecem as espécies de anuros com período reprodutivo longo bem como o aumento do período reprodutivo de espécies mais flexíveis. A utilização do nicho espacial pelos anuros adultos foi estudada em oito riachos de mata na RPPN Serra do Caraça localizada no município de Catas Altas (Minas Gerais). Os microambientes avaliados foram classificados em 18 tipos baseados nos substratos, na distância e na altura da água. Um total de 440 anuros de 19 espécies apresentaram grande seletividade na utilização desses microambientes. Espécies com nichos mais amplos (mais generalistas) não ocuparam um maior número de riachos do que as espécies mais especialistas, nem os riachos com uma maior riqueza de espécies apresentaram espécies com valores mais estreitos de nicho. As espécies apresentaram variados níveis de sobreposição na utilização dos microambientes. O padrão de distribuição observado neste estudo sugere que a competição não é um importante fator influenciando a estrutura espacial das comunidades de anuros de riachos permanentes de mata. Abstract: Anuran communities were studied at eight permanent forest streams located in the Reserva Particular do Patrimônio Natural (RPPN) Serra do Caraça, municipality of Catas Altas, Minas Gerais state, southeastern Brazil, from August 2003 to October 2004. A total of 19 anuran species was recorded in four families: Bufonidae (10.53%), Centrolenidae (5.26%), Hylidae (63.16%), and Leptodactylidae (21.05%). Number of species present in the streams was negatively related to stream volume. Rainfall and mean monthly temperatures were not related to anuran species diversity or diversity of species with calling males per month, though species differed in their temporal distributions. From the 19 species recorded, 12 exhibited calling activities during the study period and 10 were assumed to have reproduced based on records of gravid females, amplexed pairs, egg clutches, tadpoles, or post metamorphic froglets, considered as indicatives of reproduction. Stream size seems to be an important factor determining local anuran species richness, while the relatively stable climatic conditions of forested sites seems to favor anuran species with long breeding periods as well as the increase of breeding periods of more flexible species. The use of niche spatial dimension by anuran amphibians was studied in eight forest streams in the RPPN Serra do Caraça, Catas Altas municipality, Minas Gerais state, southeastern Brazil. Microhabitats were sampled and classified in 18 types based on substrate and height above ground/water. A total of 440 individual anurans of 19 species was recorded using these types of microhabitats. Anurans showed selectivity in microhabitat use. Species with broader niches (generalists) did not occur in more streams than species with narrower niches (specialists), and streams with higher species richness did not shelter more specialists. Species showed variable levels of superposition in microhabitat use. The distribution patterns observed in the studied anuran assemblages suggest that competition is not an important factor influencing the spatial structure of these assemblages in permanent forest streams.