42 research outputs found

    Simultaneous transcriptional profiling of Leishmania major and its murine macrophage host cell reveals insights into host-pathogen interactions

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    Parasites of the genus Leishmania are the causative agents of leishmaniasis, a group of diseases that range in manifestations from skin lesions to fatal visceral disease. The life cycle of Leishmania parasites is split between its insect vector and its mammalian host, where it resides primarily inside of macrophages. Once intracellular, Leishmania parasites must evade or deactivate the host's innate and adaptive immune responses in order to survive and replicate. We performed transcriptome profiling using RNA-seq to simultaneously identify global changes in murine macrophage and L. major gene expression as the parasite entered and persisted within murine macrophages during the first 72 h of an infection. Differential gene expression, pathway, and gene ontology analyses enabled us to identify modulations in host and parasite responses during an infection. The most substantial and dynamic gene expression responses by both macrophage and parasite were observed during early infection. Murine genes related to both pro- and anti-inflammatory immune responses and glycolysis were substantially upregulated and genes related to lipid metabolism, biogenesis, and Fc gamma receptor-mediated phagocytosis were downregulated. Upregulated parasite genes included those aimed at mitigating the effects of an oxidative response by the host immune system while downregulated genes were related to translation, cell signaling, fatty acid biosynthesis, and flagellum structure. The gene expression patterns identified in this work yield signatures that characterize multiple developmental stages of L. major parasites and the coordinated response of Leishmania-infected macrophages in the real-time setting of a dual biological system. This comprehensive dataset offers a clearer and more sensitive picture of the interplay between host and parasite during intracellular infection, providing additional insights into how pathogens are able to evade host defenses and modulate the biological functions of the cell in order to survive in the mammalian environment.https://doi.org/10.1186/s12864-015-2237-

    Homogeneity of the geochemical reference material BRP-1 (paranábasin basalt) and assessment of minimum mass

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    Reference materials (RM) are required for quantitative analyses and their successful use is associated with the degree of homogeneity, and the traceability and confidence limits of the values established by characterisation. During the production of a RM, the chemical characterisation can only commence after it has been demonstrated that the material has the required level of homogeneity. Here we describe the preparation of BRP-1, a proposed geochemical reference material, and the results of the tests to evaluate its degree of homogeneity between and within bottles. BRP-1 is the first of two geochemical RM being produced by Brazilian institutions in collaboration with the United States Geological Survey (USGS) and the International Association of Geoanalysts (IAG). Two test portions of twenty bottles of BRP-1 were analysed by wavelength dispersive-XRF spectrometry and major, minor and eighteen trace elements were determined. The results show that for most of the investigated elements, the units of BRP-1 were homogeneous at conditions approximately three times more rigorous than those strived for by the test of sufficient homogeneity. Furthermore, the within bottle homogeneity of BRP-1 was evaluated using small beam (1 mm(2)) synchrotron radiation XRF spectrometry and, for comparison, the USGS reference materials BCR-2 and GSP-2 were also evaluated. From our data, it has been possible to assign representative minimum masses for some major constituents (1 mg) and for some trace elements (1-13 mg), except Zr in GSP-2, for which test portions of 74 mg are recommended

    Caracterizacao litoquimica e aspectos petrologicos de rochas vulcanicas da Formacao Serra Geral: regiao centro-sul do Estado do Parana

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    This work defines the main volcanic types of Central-Southern Parana State (Serra Geral Formation), their stratigraphic relations, and which petrological process are able to explain the observed volcanic associations. -from English summar

    Continental flood basalt from the central-western regions of the Paran\ue0 plateau (Paraguay and Argentina): petrology and petrogenetic aspects.

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    Low and high TiO2 Mesozoic tholeiitic magmatism of the Maranhao Basin (NE Brazil): K/Ar age, geochemistry, petrology, isotope characteristics and relationships with Mesozoic low and high TiO2 flood basalts of the Paranà Basin (SE Brazil)

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    9nonenoneBellieni G., Piccirillo E.M., Cavazzini G., Petrini R., Comin-Chiaramonti P., Nardy, A.J.R.; Civetta L., Melfi, A.J., Zantedeschi PBellieni, G.; Piccirillo, E. M.; Cavazzini, G.; Petrini, Riccardo; Comin Chiaramonti, P.; Nardy, A. J. R.; Civetta, L.; Melfi, A. J.; Zantedeschi, P
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