Influência da expressão e educação físico motora no desenvolvimento da criança do 1º ciclo do ensino básico : contextos, perspetivas e participantes

A formação global da criança, na qual se integra a formação motora, deve ocupar um lugar de relevância na escola atual. Neste espaço, os alunos constroem o seu próprio conhecimento, e ao vivenciarem as aprendizagens de forma lúdica, potenciam o desenvolvimento de outras competências. O presente Relatório Final de Estágio encontra-se dividido em duas partes distintas: as reflexões críticas das práticas em contexto e o trabalho de investigação. Na primeira parte é apresentada uma apreciação crítica das práticas em contexto prático, nomeadamente na educação pré-escolar e do ensino do 1.º CEB. Na segunda parte damos a conhecer o trabalho de investigação, baseado num estudo de natureza quantitativa realizado no contexto de 1.º CEB de um Agrupamento de Escolas de Aveiro e de um Agrupamento de Escolas de Viseu que visa compreender a influência da Expressão e Educação Físico-Motora no desenvolvimento global da criança. Para o efeito, recorremos a autores de referência e à legislação em vigor, assim como, em termos empíricos, as respostas aos questionários dirigidos aos professoras do 1.º CEB. Os resultados encontrados apontam para o seguinte conjunto de principais conclusões: 1.º os professores atribuem muita importância às práticas motoras, constituindo-se como um fator fundamental para o desenvolvimento integral e harmonioso da criança; 2.º a Expressão e Educação Físico-Motora não têm sido uma realidade nas escolas do estudo, os professores apresentam como principais causas: a falta de condições de materiais, espaciais e de equipamentos como também a necessidade de formação, quer a nível da formação inicial quer a nível da formação contínua; 3.º os agrupamentos, as escolas e os professores devem estar implicados nos diferentes contextos nos quais circula a criança e que são promotores de formação e desenvolvimento, tanto ao nível dos quadros letivos e curriculares como também nos de enriquecimento curricular e nos projetos mais lúdicos e de recreação; 4.º a Expressão e Educação Físico-Motora deve assumir claramente o seu carácter formativo, onde a iniciativa e responsabilidade na organização deve ir ao encontro das aspirações das crianças e de toda a comunidade educativa.The overall formation of the child, in which the motor formation is integrated, must occupy a place of relevance in the present school. In this space, students construct their own knowledge, and when they experience learning in a playful way, they foster the development of other skills. This Final Internship Report is divided into two distinct parts: the critical reflections of the practices and the research work. The first part presents a critical appraisal of practices in a practical context, namely in pre-school education and 1st cycle education (1st CEB). In the second part it is presented the research work, based on a quantitative study carried out in the context of 1st CEB in two schools from Aveiro and Viseu Portuguese Grouping of Schools that aims to understand the influence of physical-motor expression in the overall development of the child. To this end, authors of reference and legislation in force, as well as, in empirical terms, the answers to the questionnaires addressed to the teachers of the 1st CEB were used as methodology to reach the desirable goal. The results lead to the following set of main conclusions: 1) teachers attach great importance to motor practices, constituting as a fundamental factor for the integral and harmonious development of the child; 2) physical-motor expression have not been a reality in the schools of the study, the main causes of teachers are: the lack of material, space and equipment conditions as well as the need for training, both in training Initial or continuing training; 3) groups, schools and teachers must be involved in the different contexts in which the child circulates and are promoters of training and development, both in terms of school and curricular frameworks as well as curriculum enrichment and more playful projects and recreation; 4) expression and physical-motor education must clearly assume its formative character, where the initiative and responsibility in the organization must meet the aspirations of the children and the entire educational community

A metaciclog?nese em Leishmania ? promovida na aus?ncia de purinas.

Parasitos do g?nero Leishmania s?o agentes causadores de um espectro de doen?as, caracterizadas por les?es cut?neas graves (localizadas ou difusas) at? ao potencialmente fatal acometimento de v?sceras, coletivamente conhecido como leishmanioses. Estas doen?as t?m in?cio quando formas infecciosas do parasito. promastigotas metac?clicas, s?o transmitidas pela picada de um flebotom?neo infectado para o hospedeiro mam?fero. H? muito que se sabe que o desenvolvimento no vetor dessas formas, processo conhecido como metaciclog?nese, ? vital para o ciclo de vida do protozo?rio e concomitante surgimento da doen?a no homem, por?m, pouco se sabe sobre os fatores que proporcionam seu aparecimento. Tem sido geralmente estabelecido que "condi??es de estresse" ir?o conduzir ao desenvolvimento de formas metac?clicas e com a exce??o de alguns estudos nenhuma an?lise detalhada da natureza molecular do fator de estresse tem sido realizada. Neste trabalho, mostramos que a presen?a/aus?ncia de nucleos?deos, em particular a adenosina, controla a metaciclog?nese em Leishmania tanto in vitro quanto in vivo. N?s descobrimos que a adi??o de um antagonista de receptor de adenosina em culturas de Leishmania amazonensis aumenta significativamente a metaciclog?nese, um efeito que pode ser revertido pela presen?a de determinados nucleos?deos de purina ou nucleobases. Al?m disso, nossos resultados mostram que a prolifera??o e metaciclog?nese s?o reguladas independentemente e que a adi??o de adenosina no meio de cultura ? suficiente para recuperar caracter?sticas proliferativas em promastigotas metac?clicos purificados. Mais importante, demonstramos que a metaciclog?nese foi inibida em f?meas de Lutzomyia longipalpis infectadas com Leishmania infantum chagasi que foram alimentadas com uma mistura de sacarose e adenosina. Esses resultados preenchem uma lacuna de conhceimento no ciclo de vida destes parasitos, demonstrando como a metaciclog?nese, um ponto chave na propaga??o do parasito ao hospedeiro mam?fero, pode ser controlada pela presen?a de purinas

Immune response to Leishmania ( Leishmania) chagasi infection is reduced in malnourished BALB/c mice

Protein-energy malnutrition and micronutrient deficiencies may down-regulate immune response and increase morbidity and mortality due to infection. In this study, a murine model was used to study the effects of protein, iron and zinc deficiencies on the immune response to Leishmania ( Leishmania) chagasi infection. Mice were initially fed a standard diet or with a diet containing 3% casein but deficient in zinc and iron. After malnutrition was established, mice were inoculated with L. chagasi and sacrificed four weeks later in order to evaluate liver and spleen parasite loads and serum biochemical parameters. Significant decreases in liver and spleen weight, an increase in the parasite loads in these organs and decreases in serum protein and glucose concentrations in malnourished animals were observed. Furthermore, the production of interferon-gamma by spleen cells from infected malnourished mice stimulated by Leishmania antigen was significantly lower compared with that in control diet mice. These data suggest that malnutrition alters the immune response to L. chagasi infection in the BALB/c model and, in association with the effects on biochemical and anatomical parameters of the host, favored increases in the parasite loads in the spleens and livers of these animals

Protein-energy malnutrition decreases immune response to Leishmania chagasi vaccine in BALB/c mice.

Protein-energy malnutrition and visceral leishmaniasis are important problems of public health affecting millions of people worldwide. Vaccine efficacy depends on the ability of individuals to mount an appropriate immune response and may be inadequate in malnourished persons. In this study, we used a mouse model to verify the effect of combined protein, iron and zinc deficiency in the response to Leishmania chagasi antigen vaccine. BALB/c mice were fed with a low-protein (3% casein), iron- and zinc-deficient diet or control diet (14% casein and sufficient in zinc and iron). After malnutrition establishment, mice were vaccinated subcutaneously with L. chagasi Ag plus saponin. After vaccination, mice were nutritionally repleted and then all mice were challenged with L. chagasi promastigotes. Four weeks later, liver and spleen parasite load was evaluated. Our data show that vaccine caused a significant reduction in parasite load in spleen and liver from mice fed with control diet. However, splenic parasitism was increased in mice fed with deficient diet and this diet caused a reduction in splenocyte IFN-γ production in response to the vaccine in repleted mice. These data suggest that malnutrition may alter immune response to L. chagasi vaccine in BALB/c model of infection, even after nutritional repletion

Leishmania amazonensis impairs DC function by inhibiting CD40 expression via A2B adenosine receptor activation.

Dendritic cells (DCs) play an essential role in the modulation of immune responses and several studies have evaluated the interactions between Leishmania parasites and DCs. While extracellular ATP exhibits proinflammatory properties, adenosine is an important anti-inflammatory mediator. Here we investigated the effects of Leishmania infection on DC responses and the participation of purinergic signalling in this process. Bone marrowderived dendritic cells (BMDCs) from C57BL/6J mice infected with Leishmania amazonensis, Leishmania braziliensis or Leishmania major metacyclic promastigotes showed decreased major histocompatibility complex (MHC) class II and CD86 expression and increased ectonucleotidase expression as compared with uninfected cells. In addition, L. amazonensis-infected DCs, which had lower CD40 expression, exhibited a decreased ability to induce T-cell proliferation. The presence of MRS1754, a highly selective A2B adenosine receptor antagonist at the time of infection increased MHC class II, CD86 and CD40 expression in L. amazonensis-infected DCs and restored the ability of the infected DCs to induce T-cell proliferation. Similar results were obtained through the inhibition of extracellular ATP hydrolysis using suramin. In conclusion, we propose that A2B receptor activation may be used by L. amazonensis to inhibit DC function and evade the immune response

Successful vaccination against Leishmania chagasi infection in BALB/c mice with freeze-thawed Leishmania antigen and Corynebacterium parvum.

This study evaluated the potential of a Leishmania antigen vaccine in protecting BALB/c mice against Leishmania chagasi. Mice received two subcutaneous doses of L. amazonensis vaccine with Corynebacterium parvum and subsequent boost was done without adjuvant. One week later, mice were challenged with L. chagasi. We observed that this vaccine caused a significant reduction in parasite load in liver and spleen and induced a high production of IFN-_ and IL-4 by spleen cells from vaccinated mice in response to Leishmania antigen. Together, our data show that this vaccine is capable of inducing a Th1/Th2 response that is important to control parasite replication

Vibrational spectroscopic characterization of the phosphate mineral althausite Mg2(PO4)(OH,F,O) - Implications for the molecular structure

Natural single-crystal specimens of althausite from Brazil, with general formula Mg2(PO4)(OH,F,O) were investigated by Raman and infrared spectroscopy. The mineral occurs as a secondary product in granitic pegmatites. The Raman spectrum of althausite is characterized by bands at 1020, 1033 and 1044 cm-1, assigned to ν1 symmetric stretching modes of the HOPO33- and PO43- units. Raman bands at around 1067, 1083 and 1138 cm-1 are attributed to both the HOP and PO antisymmetric stretching vibrations. The set of Raman bands observed at 575, 589 and 606 cm-1 are assigned to the ν4 out of plane bending modes of the PO4 and H2PO4 units. Raman bands at 439, 461, 475 and 503 cm-1 are attributed to the ν2 PO4 and H2PO4 bending modes. Strong Raman bands observed at 312, 346 cm-1 with shoulder bands at 361, 381 and 398 cm-1 are assigned to MgO stretching vibrations. No bands which are attributable to water were found. Vibrational spectroscopy enables aspects of the molecular structure of althausite to be assessed

Ecto-nucleotidase activities of promastigotes from leishmania (Viannia) braziliensis relates to parasite infectivity and disease clinical outcome.

Background: Leishmania (Viannia) braziliensis has been associated with a broad range of clinical manifestations ranging from a simple cutaneous ulcer to destructive mucosal lesions. Factors leading to this diversity of clinical presentations are not clear, but parasite factors have lately been recognized as important in determining disease progression. Given the fact that the activity of ecto-nucleotidases correlates with parasitism and the development of infection, we evaluated the activity of these enzymes in promastigotes from 23 L. braziliensis isolates as a possible parasite-related factor that could influence the clinical outcome of the disease. Methodology/Principal Findings: Our results show that the isolates differ in their ability to hydrolyze adenine nucleotides. Furthermore, we observed a positive correlation between the time for peak of lesion development in C57BL/6J mice and enzymatic activity and clinical manifestation of the isolate. In addition, we found that L. (V.) braziliensis isolates obtained from mucosal lesions hydrolyze higher amounts of adenine nucleotides than isolates obtained from skin lesions. One isolate with high (PPS6m) and another with low (SSF) ecto-nucleotidase activity were chosen for further studies. Mice inoculated with PPS6m show delayed lesion development and present larger parasite loads than animals inoculated with the SSF isolate. In addition, PPS6m modulates the host immune response by inhibiting dendritic cell activation and NO production by activated J774 macrophages. Finally, we observed that the amastigote forms from PPS6m and SSF isolates present low enzymatic activity that does not interfere with NO production and parasite survival in macrophages. Conclusions/Significance: Our data suggest that ecto-nucleotidases present on the promastigote forms of the parasite may interfere with the establishment of the immune response with consequent impaired ability to control parasite dissemination and this may be an important factor in determining the clinical outcome of leishmaniasis

Adenosine reverses metacyclogenesis <i>in vitro</i> and reduces <i>in vivo</i> development of metacyclic promastigotes.

<p>(A) Metacyclic promastigotes from CGS-treated cultures, obtained by Ficoll gradient centrifugation, were cultivated in “spent” medium (late stationary phase medium from control cultures) or in “spent” medium plus adenosine (Ado). Parasite growth was evaluated by hemocytometer counting. (B) Metacyclic promastigotes from CGS-treated cultures, obtained by Ficoll gradient centrifugation followed by complement mediated lysis (as in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001833#pntd-0001833-g002" target="_blank">Figure 2D</a>), were cultured in Grace's insect medium without supplements or in this medium plus adenosine. Parasite growth was evaluated by hemocytometer counting. (C) General aspect of metacyclic promastigotes after double purification (Ficoll + complement) (upper left). Cells after 72 hr of incubation in Grace's insect medium without supplements (upper right), or in the presence of 100 µM (lower left) or 500 µM of adenosine (lower right). Pictures taken with an Axio Cam MR3 attached to a Carl-Zeiss Axio Imager M2 microscope. Adult insects of <i>Lutzomyia longipalpis</i>, majority of females, were allowed to feed in a naturally <i>Leishmania infantum chagasi</i>-infected dog for 30 min. Insects were fed for 8 to10 days with 30% sucrose solution with or without adenosine (5 mM). Each midgut was evaluated by light microscopy for the total amount of parasites (D) and for the percentage of metacyclic promastigotes (E). (F) Image of a metacyclic (upper panel) and non-metacyclic promastigote (lower panel) of <i>L. infantum chagasi</i> from sand fly midgut. Pictures taken with a DFC300FX camera attached to a Leica DM5000B microscope. Means and standard deviations (or medians in graph E) from at least two independent experiments are plotted; *p<0.05, ***p<0.0001 determined by two-tailed Student's t-test indicate significant difference from control group.</p

Presence of CGS 15943 in <i>Leishmania amazonensis</i> culture halts parasite growth and enhances metacyclogenesis.

<p>(A) Evaluation of <i>L. amazonensis</i> growth in Grace's insect medium containing different concentrations of CGS as determined by hemocytometer counting. (B) Viability of parasites was assessed by flow cytometry using propidium iodide incorporation after 72 hr of culture. Phase contrast image of DMSO-treated (C) and CGS-treated (D) cultures of <i>L. amazonensis</i> promastigotes (picture taken with an Axio Cam MR3 attached to a Carl-Zeiss Axio Imager M2 microscope). Percentage of metacyclic promastigotes in control (Medium; DMSO) and CGS-treated cultures was evaluated by differential counting in optical microscopy (E) and Ficoll density gradient purification (F). Means and standard deviations from at least three independent experiments are plotted; *p<0.05, **p<0.01 determined by two-tailed Student's t-test indicate significant difference from control group.</p