527 research outputs found

    Index de la chronique bibliographique

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    Foram analisados a relação peso-comprimento e o fator de condição de Astyanax intermedius parasitados ou não pelo isópode Paracymothoa astyanaxi. A relação peso-comprimento foi estimada para fêmeas, machos e imaturos, e sazonalmente tanto para os peixes quanto para o parasito, por meio da expressão P = aCb. O fator de condição dos exemplares não parasitados diferiu sazonalmente e entre os sexos, contrastando com os valores do fator de condição dos peixes parasitados, que não apresentaram diferenças sazonais e entre os sexos. O fator de condição dos exemplares não parasitados foi sempre maior do que o dos exemplares parasitados. Os exemplares de Astyanax intermedius parasitados não passaram pelas mesmas condições bióticas dos indivíduos não parasitados, apresentando um fator de condição semelhante ao longo do ano. Conclui-se que o parasitismo por P. astyanaxi atua de forma deletéria na população desse hospedeiro, podendo causar alterações nas dinâmicas reprodutiva e alimentar dos exemplares parasitados em razão da baixa condição corpórea.In this work the length-weight relationship and the condition factor of Astyanax intermedius parasitised and not by Paracymothoa astyanaxi were analysed in the Grande River. The length-weight relationship was estimated for females, males and immatures, and seasonally for the fishes and the parasites through the expression W = aLb. The condition factor of non-parasitised specimens differed seasonally and between sexes, contrasting with the results for parasitised fishes which showed no differences between sexes and season. The condition factor of non-parasitised specimens was higher than that of the parasitised fishes. Specimens of Astyanax intermedius parasitised do not have the same biotic conditions compared to non-parasitised individuals, in which the condition factor was similar over the years. In conclusion, parasitism by P. astyanaxi has deleterious effects on this host population which may cause changes in the reproductive and food dynamics of parasitised specimens due to low body conditions

    Mtss1 promotes cell-cell junction assembly and stability through the small GTPase Rac1

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    Cell-cell junctions are an integral part of epithelia and are often disrupted in cancer cells during epithelial-to-mesenchymal transition (EMT), which is a main driver of metastatic spread. We show here that Metastasis suppressor-1 (Mtss1; Missing in Metastasis, MIM), a member of the IMD-family of proteins, inhibits cell-cell junction disassembly in wound healing or HGF-induced scatter assays by enhancing cell-cell junction strength. Mtss1 not only makes cells more resistant to cell-cell junction disassembly, but also accelerates the kinetics of adherens junction assembly. Mtss1 drives enhanced junction formation specifically by elevating Rac-GTP. Lastly, we show that Mtss1 depletion reduces recruitment of F-actin at cell-cell junctions. We thus propose that Mtss1 promotes Rac1 activation and actin recruitment driving junction maintenance. We suggest that the observed loss of Mtss1 in cancers may compromise junction stability and thus promote EMT and metastasis

    Inhibitory action of phenothiazinium dyes against Neospora caninum.

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    Neospora caninum is an Apicomplexan parasite related to important losses in livestock, causing abortions and decreased fertility in affected cows. Several chemotherapeutic strategies have been developed for disease control; however, no commercial treatment is available. Among the candidate drugs against neosporosis, phenothiazinium dyes, offer a low cost-efficient approach to parasite control. We report the anti-parasitic effects of the phenothiaziums Methylene Blue (MB), New Methylene Blue (NMB), 1,9-Dimethyl Methylene Blue (DMMB) and Toluidine Blue O (TBO) on N. caninum, using in vitro and in vivo models. The dyes inhibited parasite proliferation at nanomolar concentrations (0.019-1.83 μM) and a synergistic effect was achieved when Methylene Blue was combined with New Methylene Blue (Combination Index = 0.84). Moreover, the phenothiazinium dyes improved parasite clearance when combined with Pyrimethamine (Pyr). Combination of Methylene Blue + 1,9-Dimethyl Methylene Blue demonstrated superior efficacy compared to Pyrimethamine based counterparts in an in vivo model of infection. We also observed that Methylene Blue, New Methylene Blue and 1,9-Dimethyl Methylene Blue increased by 5000% the reactive oxygen species (ROS) levels in N. caninum tachyzoites. Phenothiazinium dyes represent an accessible group of candidates with the potential to compound future formulations for neosporosis control

    Social research on neglected diseases of poverty: Continuing and emerging themes

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    Copyright: © 2009 Manderson et al.Neglected tropical diseases (NTDs) exist and persist for social and economic reasons that enable the vectors and pathogens to take advantage of changes in the behavioral and physical environment. Persistent poverty at household, community, and national levels, and inequalities within and between sectors, contribute to the perpetuation and re-emergence of NTDs. Changes in production and habitat affect the physical environment, so that agricultural development, mining and forestry, rapid industrialization, and urbanization all result in changes in human uses of the environment, exposure to vectors, and vulnerability to infection. Concurrently, political instability and lack of resources limit the capacity of governments to manage environments, control disease transmission, and ensure an effective health system. Social, cultural, economic, and political factors interact and influence government capacity and individual willingness to reduce the risks of infection and transmission, and to recognize and treat disease. Understanding the dynamic interaction of diverse factors in varying contexts is a complex task, yet critical for successful health promotion, disease prevention, and disease control. Many of the research techniques and tools needed for this purpose are available in the applied social sciences. In this article we use this term broadly, and so include behavioral, population and economic social sciences, social and cultural epidemiology, and the multiple disciplines of public health, health services, and health policy and planning. These latter fields, informed by foundational social science theory and methods, include health promotion, health communication, and heath education
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