36 research outputs found

    FREEDOM DOESN'T TAKE HOLIDAYS: PLAY FREE, PLAY AND EARLY CHILDHOOD EDUCATION

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    Este trabalho debate o brincar livre como um caminho didático a alicerçar a relação entre adultos de referência e crianças, a partir da concepção de uma criança potente e capaz de construir saberes de forma autônoma e independente. A pesquisa relatada tem cunho etnográfico (ANDRÉ, 1995) e os dados para análise foram coletados através de observações, filmagem e diário de campo até a produção de uma análise microgenética realizada dentro do espaço físico escolar. Busca-se desmistificar a polaridade entre atividade lúdica e sistemática fazendo-nos olhar para os processos de integração das culturas lúdica, infantil e educativa. Do mesmo modo, pressupõe-se que os elementos que distinguem as atividades lúdicas das sistematizadas podem ser revelados através do grau de iniciativa e protagonismo das crianças ao realizá-las. Entende-se que o brincar parece mais livre que uma atividade sistemática, por possuir polissemia aberta. Curiosamente, a análise de algumas situações gravadas mostrou-nos que, quando é resguardada à criança a liberdade de escolher o processo de realização dessas atividades, a atividade sistemática também oferece abertura polissêmica tanto quanto as atividades lúdicas. Este artículo debate el juego libre como un camino didáctico para basar la relación entre adultos de referencia y los niños, a partir de la concepción de un niño potente y capaz de construir conocimientos de manera autónoma e independiente. La investigación aquí relatada posee un abordaje etnográfico (ANDRÉ, 1995) y los datos para el análisis fueron colectados  a través de observaciones, grabaciones  y un diario de campo, hasta la producción de un análisis microgenético realizado dentro del espacio físico de la escuela. Se busca desmitificar la polaridad entre la actividad lúdica y la actividad sistemática, haciéndonos observar los procesos de integración de las culturas: lúdica, infantil y educativa. Del mismo modo, se presupone que los elementos que distinguen las actividades lúdicas de las sistemáticas pueden ser revelados a través del grado de iniciativa y de protagonismo de los niños al realizar las actividades. Se entiende que el juego parece más libre que una actividad sistemática, debido poseer una polisemia abierta. Curiosamente, el análisis de algunas situaciones gravadas nos ha revelado que, cuando es garantizado al niño la libertad de elegir  el proceso de realización de esas actividades, la actividad sistemática también ofrece la abertura polisémica en la misma medida que las actividades lúdicas.This task discusses free play as a didactic way to support the relationship between reference adults and children, from the conception of a powerful child capable of building knowledge in an autonomous and independent way. The research reported has an ethnographic nature (ANDRÉ, 1995) and the data for analysis were collected through observations, filming and a field diary until the production of a microgenetic analysis carried out within the school’s physical space. The goal is to demystify the polarity between playful and systematic activity, making us look at the integration processes of playful’s culture, children's  and educational. Likewise, it is assumed that the elements that distinguish playful activities from systematized ones can be revealed through the children's degree of initiative and protagonism when performing them. It is understood that playing seems more free than a systematic activity, as it has open polysemy. Interestingly, the analysis of some recorded situations showed us that, when the child is free to choose the process of carrying out these activities, the systematic activity also offers polysemic opening as much as recreational activitie

    Identification of Novel Immunoregulatory Molecules in Human Thymic Regulatory CD4+CD25+ T Cells by Phage Display

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    Thymic CD4+CD25+ cells play an important role in immune regulation and are continuously developed in the thymus as an independent lineage. How these cells are generated, what are their multiple pathways of suppressive activity and which are their specific markers are questions that remain unanswered. To identify molecules involved in the function and development of human CD4+CD25+ T regulatory cells we targeted thymic CD4+CD25+ cells by peptide phage display. A phage library containing random peptides was screened ex vivo for binding to human thymic CD4+CD25+ T cells. After four rounds of selection on CD4+CD25+ enriched populations of thymocytes, we sequenced several phage displayed peptides and selected one with identity to the Vitamin D Receptor (VDR). We confirmed the binding of the VDR phage to active Vitamin D in vitro, as well as the higher expression of VDR in CD4+CD25+ cells. We suggest that differential expression of VDR on natural Tregs may be related to the relevance of Vitamin D in function and ontogeny of these cells

    Infância e normatização: lugar de criança e o discurso social da inclusão e exclusão

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    This paper cover a historical path of childhood relationship. It discusses the ways of social inclusion and exclusion. The culture normalize the social discourse. We approach the current social discourse too, that it's very restrictive.Este artículo aborda el recorrido de los modos de relación con la infancia en las diferentes épocas de la historia. Tiene por objetivo discutir las formas de inclusión y exclusión social del niño. La cultura promueve discursos sociales normalizadores. Abordamos el discurso actual, que impone un estrecho margen de normalidad.Este artigo aborda o percurso dos modos de relação com a infância nas diferentes épocas da história. Tem por objetivo discutir as formas de inclusão e exclusão social da criança. A cultura promove discursos sociais normatizadores. Abordamos o discurso atual, que impõe uma estreita margem de normalidade

    Organization of health services and tuberculosis care management

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    Este estudo teve como objetivo analisar a discursividade de gestores sobre a relação entre a organização dos serviços de saúde e a gestão do cuidado à tuberculose (TB) em um município da região metropolitana de João Pessoa/PB. Conduzido pela pesquisa qualitativa no campo analítico da Análise de Discurso de linha francesa, participaram 16 trabalhadores de saúde que atuavam como integrantes de equipes gestoras. Os depoimentos transcritos foram organizados com uso do software Atlas.ti versão 6.0. Após leitura minuciosa do material empírico procurou-se observar nos discursos os processos parafrásicos, polissêmicos e metafóricos, os quais possibilitaram a identificação da seguinte formação discursiva: organização dos serviços de saúde e a relação com a gestão do cuidado à TB; o plano e a prática. Nos discursos dos gestores evidencia-se a fragmentação das ações de controle da tuberculose, a falta de articulação entre os serviços e os setores, o cumprimento de atividades específicas à TB, bem como a falta de planejamento estratégico para gestão do cuidado da doença. Nesse sentido, para que a organização dos serviços de saúde seja efetiva, se faz necessário que a tuberculose seja prioridade na agenda da gestão e reconhecida como um problema social.The scope of this study was to analyze the discourse of managers regarding the relationship between the organization of the health services and tuberculosis care management in a city in the metropolitan region of Joao Pessoa, State of Pernambuco. Using qualitative research in the analytical field of the French line of Discourse Analysis, 16 health workers who worked as members of the management teams took part in the study. The transcribed testimonials were organized using Atlas.ti version 6.0 software. After detailed reading of the empirical material, an attempt was made to identify the paraphrasic, polyssemic and metaphoric processes in the discourses, which enabled identification of the following discourse formation: Organization of the health services and the relation with TB care management: theory and practice. In the discourse of the managers the fragmentation of the actions of control of tuberculosis, the lack of articulation between the services and sectors, the compliance of the specific activities for TB, as well as the lack of strategic planning for management of care of the disease are clearly revealed. In this respect, for the organization of the health services to be effective, it is necessary that tuberculosis be considered a priority and acknowledged as a social problem in the management agenda

    Envelope Deglycosylation Enhances Antigenicity of HIV-1 gp41 Epitopes for Both Broad Neutralizing Antibodies and Their Unmutated Ancestor Antibodies

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    The HIV-1 gp41 envelope (Env) membrane proximal external region (MPER) is an important vaccine target that in rare subjects can elicit neutralizing antibodies. One mechanism proposed for rarity of MPER neutralizing antibody generation is lack of reverted unmutated ancestor (putative naive B cell receptor) antibody reactivity with HIV-1 envelope. We have studied the effect of partial deglycosylation under non-denaturing (native) conditions on gp140 Env antigenicity for MPER neutralizing antibodies and their reverted unmutated ancestor antibodies. We found that native deglycosylation of clade B JRFL gp140 as well as group M consensus gp140 Env CON-S selectively increased the reactivity of Env with the broad neutralizing human mAbs, 2F5 and 4E10. Whereas fully glycosylated gp140 Env either did not bind (JRFL), or weakly bound (CON-S), 2F5 and 4E10 reverted unmutated ancestors, natively deglycosylated JRFL and CON-S gp140 Envs did bind well to these putative mimics of naive B cell receptors. These data predict that partially deglycoslated Env would bind better than fully glycosylated Env to gp41-specific naïve B cells with improved immunogenicity. In this regard, immunization of rhesus macaques demonstrated enhanced immunogenicity of the 2F5 MPER epitope on deglyosylated JRFL gp140 compared to glycosylated JRFL gp140. Thus, the lack of 2F5 and 4E10 reverted unmutated ancestor binding to gp140 Env may not always be due to lack of unmutated ancestor antibody reactivity with gp41 peptide epitopes, but rather, may be due to glycan interference of binding of unmutated ancestor antibodies of broad neutralizing mAb to Env gp41

    Trypanosoma cruzi Epimastigotes Are Able to Store and Mobilize High Amounts of Cholesterol in Reservosome Lipid Inclusions

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    Reservosomes are lysosome-related organelles found in Trypanosoma cruzi epimastigotes. They represent the last step in epimastigote endocytic route, accumulating a set of proteins and enzymes related to protein digestion and lipid metabolism. The reservosome matrix contains planar membranes, vesicles and lipid inclusions. Some of the latter may assume rectangular or sword-shaped crystalloid forms surrounded by a phospholipid monolayer, resembling the cholesterol crystals in foam cells.Using Nile Red fluorimetry and fluorescence microscopy, as well as electron microscopy, we have established a direct correlation between serum concentration in culture medium and the presence of crystalloid lipid inclusions. Starting from a reservosome purified fraction, we have developed a fractionation protocol to isolate lipid inclusions. Gas-chromatography mass-spectrometry (GC-MS) analysis revealed that lipid inclusions are composed mainly by cholesterol and cholesterol esters. Moreover, when the parasites with crystalloid lipid-loaded reservosomes were maintained in serum free medium for 48 hours the inclusions disappeared almost completely, including the sword shaped ones.Taken together, our results suggest that epimastigote forms of T. cruzi store high amounts of neutral lipids from extracellular medium, mostly cholesterol or cholesterol esters inside reservosomes. Interestingly, the parasites are able to disassemble the reservosome cholesterol crystalloid inclusions when submitted to serum starvation

    Peptide phage display for the identification of novel molecular markers on human thymic regulatory CD4+CD25+ T cells

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    Há dados na literatura indicando que as células que saem do timo com o fenótipo CD4+CD25+ são desenvolvidas continuamente como uma linhagem independente e possuem um papel importante no processo de regulação da resposta imune. Essas células são chamadas células T reguladoras naturais. Várias questões sobre estas células permanecem em aberto, como por exemplo, como elas são geradas, o que é determinante na sua atividade reguladora e que marcadores específicos podem ser usados para identificá-las? Dentro deste contexto, o nosso objetivo neste trabalho foi identificar no timo e em timócitos CD4+/CD25+ humanos, novas moléculas potencialmente importantes no desenvolvimento e/ou na atividade supressora das células T reguladoras naturais. Para este objetivo, utilizamos a abordagem de phage display, com uma biblioteca de fagos de peptídeos, e timos humanos obtidos de pacientes portadores de cardiopatias congênitas, submetidos a cirurgias cardíacas realizadas no InCor. A busca dessas moléculas foi feita, separadamente, em 3 tipos de material biológico: timócitos totais, fragmento do tecido tímico e timócitos CD4+/CD25+. Antes da incubação da biblioteca de fagos com os timócitos totais e timócitos CD4+/CD25+ (separação em FACS), foi realizada uma etapa de preclearing, incubando-se a biblioteca de fagos com um pool de células mononucleares de sangue periférico (PBMC) ou timócitos CD4+/CD25-, respectivamente. Os fagos não ligantes, recuperados desta etapa, foram então incubados com as células de interesse. Para o tecido tímico não foi feita etapa de pre-clearing. Os fagos obtidos com os diferentes materiais biológicos foram recuperados em cultura de bactérias e usados em ciclos posteriores de seleção. Após três ciclos de seleção, os fagos foram seqüenciados e identificados quanto à expressão de peptídeos ligantes para timócitos totais, timo e timócitos CD4+/CD25+, e analisados em bancos de dados no BLAST. Os fagos selecionados para validação um ligante de tecido tímico: M2C e um ligante de timócitos CD4+/CD25+: R2A fazem similaridade a duas proteínas associadas ao metabolismo da Vitamina D3, molécula envolvida em imunorregulação e indução de tolerância, em diversos modelos experimentais. Porém, não há dados na literatura a respeito do seu papel em células T reg naturais. Na validação molecular desses fagos, apesar de certa variabilidade entre os diferentes ensaios, verificamos, por ELISA, que os fagos se ligam preferencialmente a 1,25 diidroxivitamina D3, forma ativa da Vitamina D3. Entretanto, nos ensaios de validação funcional, a influência da vitamina D na diferenciação dessas células não foi confirmada de forma consistente, uma vez que só tivemos aumento no número de células CD4+/CD25+, em cultura com Vitamina D, em poucos experimentos. As moléculas identificadas no presente estudo podem ter implicações relevantes no processo de diferenciação e na atividade de células T CD4+CD25+ reguladoras e serão mais investigadas na continuidade deste trabalho.There are consistent data in literature indicating that thymic CD4+CD25+ cells play an important role in immune regulation and are continuously developed as an independent lineage in the thymus. These cells are known as natural regulatory T cells. Several questions about these cells remain unanswered, such as how they are generated, what is determinant in their regulatory function and which specific molecular markers can be used to identify them. Taking this into consideration, our aim was to identify new potentially important molecules in the development and/or supressive function of natural regulatory T cells, both in the thymus and in CD4+CD25+ thymocytes. For this, the phage display technique was employed, with a peptide phage library and thymic specimens obtained from children who underwent corrective cardiac surgery at the Heart Institute (InCor), in São Paulo. The search for these molecules was separately performed in 3 types of biological material: thymic tissue, thymocytes and CD4+CD25+ thymic cells. In the first stage, the phage peptide-library was incubated with a pool of PBMC (peripheral blood mononuclear cells). After the incubation, phages bound to PBMC were discarded (pre-clearing). In the second stage, unbound phages were incubated with either total thymocytes or CD4+CD25+ thymic cells. The pre-clearing stage was not perfomed in the thymic tissue. The phages obtained with after incubation with the different biological materials were recovered in E. coli culture and used in additional cycles of selection. After three rounds of selection, the recovered phages from the total thymocytes, from thymic tissue and thymocytes CD4+CD25+ were sequenced and their ligands identified. Among the phages selected for validation one ligand of thymic tissue: M2C and one ligand of CD4+CD25+ thymocytes: R2A present similarity to two proteins associated to the metabolism of Vitamin D3, a molecule involved in imunoregulation and toelrance induction in several experimental models. However, there are no data in the literature concerning the possible role of this moelcule in natural regulatory T cells. In the molecular validation of theses phages, although some variability between the diffeterent assays we have verified by ELISA, that the phages present preferential binding to the 1,25 dhydroxyvitamin D3, the active form of Vitamin D3. However, in the functional validation assays, the influence of the Vitamin D3 in the differentiation of these cells could not be consistently confirmed since we could observe an increase in the number of CD4+CD25+ cells cultured with vitamin D in only a few experiments. The ligand-receptor molecules we have defined in this study may have relevant implications in the development of CD4+CD25+ regulatory T cells in the thymu
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