Reevaluating the Trypanosoma cruzi proteomic map: The shotgun description of bloodstream trypomastigotes.

Chagas disease is a neglected disease, caused by the protozoan Trypanosoma cruzi. This kinetoplastid presents a cycle involving different forms and hosts, being trypomastigotes the main infective form. Despite various T. cruzi proteomic studies, the assessment of bloodstream trypomastigote profile remains unexplored. The aim of this work is T. cruzi bloodstream form proteomic description. Employing shotgun approach, 17,394 peptides were identified, corresponding to 7514 proteins of which 5901 belong to T. cruzi. Cytoskeletal proteins, chaperones, bioenergetics-related enzymes, and trans-sialidases are among the top-scoring. GO analysis revealed that all T. cruzi compartments were assessed; and majority of proteins are involved in metabolic processes and/or presented catalytic activity. The comparative analysis between the bloodstream trypomastigotes and cultured-derived or metacyclic trypomastigote proteomic profiles pointed to 2202 proteins exclusively detected in the bloodstream form. These exclusive proteins are related to: (a) surface proteins; (b) non-classical secretion pathway; (c) cytoskeletal dynamics; (d) cell cycle and transcription; (e) proteolysis; (f) redox metabolism; (g) biosynthetic pathways; (h) bioenergetics; (i) protein folding; (j) cell signaling; (k) vesicular traffic; (l) DNA repair; and (m) cell death. This large-scale evaluation of bloodstream trypomastigotes, responsible for the parasite dissemination in the patient, marks a step forward in the comprehension of Chagas disease pathogenesis. BIOLOGICAL SIGNIFICANCE: The hemoflagellate protozoan T. cruzi is the etiological agent of Chagas disease and affects people by the millions in Latin America and other non-endemic countries. The absence of efficient drugs, especially for treatment during the chronic phase of the disease, stimulates the continuous search for novel molecular targets. The identification of essential molecules, particularly those found in clinically relevant forms of the parasite, could be crucial. Inside the vertebrate host, trypomastigotes circulate in the bloodstream before infecting various tissues. The exposure of bloodstream forms of the parasite to the host immune system likely leads to differential protein expression in the parasite. In this context, an extensive characterization of the proteomic profile of bloodstream trypomastigotes could help to find not only promising drug targets but also antigens for vaccines or diagnostics. This work is a large-scale proteomic assessment of bloodstream trypomastigotes that show a considerable number of proteins belonging to different metabolic pathways and functions exclusive to this parasitic form, and provides a valuable dataset for the biological understanding of this clinically relevant form of T. cruzi.

Classical analysis of quantum phase transitions in a bilayer model.

In this Brief Report we extend the classical analysis performed on the schematic model proposed in [T. Moreira, G. Q. Pellegrino, J. G. Peixoto de Faria, M. C. Nemes, F. Camargo, and A. F. R. Toledo Piza, Phys. Rev. E 77, 051102 (2008)] concerning quantum phase transitions in a bilayer system. We show that appropriate integrations along the classical periodic orbits reproduce with excellent agreement both the quantum spectrum and the expected mean value for the number of excitons in the system, quantities which are directly related to the observed boson-fermion quantum phase transition.

Relações socioprofissionais como elemento de influência na construção das identidades docentes / Socio-professional relations as an element of influence in the construction of identities teachers

Este texto apresenta o relatório final de uma dissertação de mestrado. Busca compreender como uma professora de Educação Física constrói suas identidades docentes, considerando as experiências relacionais vivenciadas com a organização/estrutura da instituição, com os sujeitos adultos e com os sujeitos crianças no contexto da educação infantil. Trata de uma pesquisa qualitativa que acompanhou a professora, por meio de observações,entrevistas, análise documental. O processo analítico visualizou quatro aspectos: reflexões sobre si; relaçõesestabelecidas entre Vitória e a estrutura/organização da Escola J; relações estabelecidas entre Vitória e outros sujeitos adultos da Escola J; relações estabelecidas entre Vitória e as crianças da Escola J.

This paper has the f inal report of a dissertation. Seeks to understand how a teacher of Physical Education teachers construct their identities, considering the relational experiences with experienced organization/structure of the institution with adult subjects and subjects with children in the context of early education of children. This is aqualitative research that accompanied the teacher, through observations, interviews, documentary analysis. The analytical process viewed four aspects: reflections on itself; relations between Victoria and the structure/organization of the School J; relations established between Victoria and other adult subjects J School; relations established between Victoria and the children of the School J.

En este trabajo se presenta el informe final de una disertación. Trata de comprender cómo al maestro de Educación Física construyen sus identidades, teniendo en cuenta las experiências relacionales con experiencia em organización/estructura de la institución con personas adultas y personas con niños en el contexto de la educación infantil. Esta es una investigación cualitativa que acompaña al maestro, a través de observaciones, entrevistas, análisis documental. El proceso de análisis prevé cuatro aspectos: reflexiones sobre sí mismo; las relaciones entre Victoria y la estructura/organización de la Escuela de J; las relaciones entre Victoria y otros adultos de la Escuela de J; las relaciones entre Victoria y los niños de la escuela J.

Activation of the cAMP cascade inhibits an early event involved in murine macrophage Ia expression.

The ability of interferon-gamma (IFN gamma) to increase class II major histocompatibility complex (class II MHC) gene products in murine macrophages involves activation of Na+/H+ exchange (Prpic V., Yu, S. F., Figueiredo, F., Hollenbach, P. W., Gawdi, G., Herman, B., Uhing, R. J., and Adams, D. O. (1989) Science 244, 469-471). The ability of IFN gamma to increase class II MHC gene product expression is inhibited by a variety of agents. In the present studies, the involvement of cAMP-dependent protein kinase in modulating IFN gamma-induced expression of MHC gene products and the mechanism of regulation were assessed in macrophages treated with agents which activated cAMP-dependent protein kinase by different molecular mechanisms. Prostaglandin E2 (PGE2) produced a rapid (within 30 s) dose-dependent elevation of cAMP which was paralleled by the activation of cAMP-dependent protein kinase. The elevation of cAMP by PGE2 was still evident at 1 h and maintained through a 4-h incubation. Concentrations of PGE2 which activated the protein kinase produced a dose-dependent inhibition of surface expression of I-A and transcription of class II MHC genes. Inhibition of IFN gamma-induced class II MHC gene product expression was also observed in macrophages treated with agents which activated cAMP-dependent protein kinase by postreceptor mechanisms. Dibutyryl-cAMP (0.01-1 mM), 25 microM forskolin, 0.1 micrograms/ml cholera toxin, and 3-isobutyl-1-methylxanthine (0.1-1 mM) each suppressed IFN gamma-induced cell surface I-A expression, class II MHC gene transcription, and 22Na+ influx. The results are consistent with the suggestion that activation of cAMP-dependent protein kinase regulates an early transductional event initiated by IFN gamma, perhaps Na+/H+ exchange, which is involved in regulating transcription of class II MHC genes and their subsequent expression.