2,004 research outputs found

    Approches immunologiques potentielles du traitement du paludisme humain

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    Effects of Dietary Energy Density on Diet and Nutrient Digestibility in Beef Cattle Diets

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    Steers were fed diets containing energy concentrations of 2.4, 2.7, or 3.0 Mcal of ME/kg of DM to evaluate nutrient and diet digestibility and to determine the existence of associative effects when feeding diets with varying forage and concentrate ratios. The steers were placed in metabolism crates for total fecal collection. Dry matter digestibility was higher for diets with greater energy density. The 2.7 Mcal/kg diet showed a small negative associative effect on digestibility and the non-fiber carbohydrate fraction was the nutrient that had an inhibition on digestion. The results indicated that diets varying in concentration of forage and concentrate may have different digestibilities and nutritional values

    Germinal center architecture disturbance during Plasmodium berghei ANKA infection in CBA mice

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    <p>Abstract</p> <p>Background</p> <p>Immune responses to malaria blood stage infection are in general defective, with the need for long-term exposure to the parasite to achieve immunity, and with the development of immunopathology states such as cerebral malaria in many cases. One of the potential reasons for the difficulty in developing protective immunity is the poor development of memory responses. In this paper, the potential association of cellular reactivity in lymphoid organs (spleen, lymph nodes and Peyer's patches) with immunity and pathology was evaluated during <it>Plasmodium berghei </it>ANKA infection in CBA mice.</p> <p>Methods</p> <p>CBA mice were infected with 1 × 10<sup>6 </sup><it>P. berghei </it>ANKA-parasitized erythrocytes and killed on days 3, 6–8 and 10 of infection. The spleen, lymph nodes and Peyer's patches were collected, fixed in Carson's formalin, cut in 5 μm sections, mounted in glass slides, stained with Lennert's Giemsa and haematoxylin-eosin and analysed with bright-field microscopy.</p> <p>Results</p> <p>Early (day 3) strong activation of T cells in secondary lymphoid organs was observed and, on days 6–8 of infection, there was overwhelming activation of B cells, with loss of conventional germinal center architecture, intense centroblast activation, proliferation and apoptosis but little differentiation to centrocytes. In the spleen, the marginal zone disappeared and the limits between the disorganized germinal center and the red pulp were blurred. Intense plasmacytogenesis was observed in the T cell zone.</p> <p>Conclusion</p> <p>The observed alterations, especially the germinal center architecture disturbance (GCAD) with poor centrocyte differentiation, suggest that B cell responses during <it>P. berghei </it>ANKA infection in mice are defective, with potential impact on B cell memory responses.</p

    Hypoxia-inducible factor-1α (HIF-1α) inhibition impairs retinoic acid-induced differentiation in SH-SY5Y neuroblastoma cells, leading to reduced neurite length and diminished gene expression related to cell differentiation

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    Neuroblastoma is the most common extracranial solid tumour in childhood, originated from cells of the neural crest during the development of the Sympathetic Nervous System. Retinoids are vitamin-A derived differentiating agents utilised to avoid disease resurgence in high-risk neuroblastoma treatment. Several studies indicate that hypoxia—a common feature of the tumoural environment—is a key player in cell differentiation and proliferation. Hypoxia leads to the accumulation of the hypoxia-inducible factor-1α (HIF-1α). This work aims to investigate the effects of the selective inhibition of HIF-1α on the differentiation induced by retinoic acid in human neuroblastoma cells from the SH-SY5Y lineage to clarify its role in cell differentiation. Our results indicate that HIF-1α inhibition impairs RA-induced differentiation by reducing neuron-like phenotype and diminished immunolabeling and expression of differentiation markers

    In Vitro Antimalarial Activity of Crude Extracts of Phothomorphe peltata and P. umbellata (Piperaceae)

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    The in vitro antimalarial activity of hexane and methanol extracts of Pothomorphe peltata (L.) Miq. and P. umbellata (L.) Miq. (Piperaceae), two plants used in the Brazilian folk medicine in the treatment of malaria, was assessed against three Plasmodium falciparum strains with different patterns of sensitivity to the standard antimalarial drug chloroquine. Although both fractions had showed considerable activity in the system, methanol extracts of both plants were more effective in inhibiting plasmodial growth in vitro than the hexane ones

    Polyclonal B-cell activation in human malaria: relevance to the development of anti-sporozoite specific immune response and of immunopathology in individuals from endemic areas (Rondonia State - Brazil)

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    Submitted by Sandra Infurna ([email protected]) on 2019-11-06T13:58:05Z No. of bitstreams: 1 ClaudioTD_Ribeiro_etal_IOC_1988.pdf: 290888 bytes, checksum: 7adcc5b866ba2f6d06cc2cc9d40bb169 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2019-11-06T14:16:46Z (GMT) No. of bitstreams: 1 ClaudioTD_Ribeiro_etal_IOC_1988.pdf: 290888 bytes, checksum: 7adcc5b866ba2f6d06cc2cc9d40bb169 (MD5)Made available in DSpace on 2019-11-06T14:16:46Z (GMT). No. of bitstreams: 1 ClaudioTD_Ribeiro_etal_IOC_1988.pdf: 290888 bytes, checksum: 7adcc5b866ba2f6d06cc2cc9d40bb169 (MD5) Previous issue date: 1988Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Imunologia. Centro Colaborador da OMS para Pesquisa e Treinamento em Imunologia de Doenças Parasitárias. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Imunologia. Centro Colaborador da OMS para Pesquisa e Treinamento em Imunologia de Doenças Parasitárias. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Imunologia. Centro Colaborador da OMS para Pesquisa e Treinamento em Imunologia de Doenças Parasitárias. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Imunologia. Centro Colaborador da OMS para Pesquisa e Treinamento em Imunologia de Doenças Parasitárias. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Imunologia. Centro Colaborador da OMS para Pesquisa e Treinamento em Imunologia de Doenças Parasitárias. Rio de Janeiro, RJ, Brasil

    O impacto de métodos ativos no ensino de Química para alunos da EJA

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    Esta pesquisa objetivou avaliar o impacto dos métodos ativos Instrução pelos Colegas (IpC) + Ensino sob Medida (EsM) nas crenças dos alunos do ensino médio da Educação de Jovens e Adultos (EJA) de um colégio da rede federal do Rio de Janeiro, em relação às aulas de química. Para isso, os alunos tiveram aulas sobre ligações químicas com os métodos IpC + EsM e aulas regulares expositivas sobre os demais tópicos da disciplina, visando compará-las. Coletamos os dados por meio de uma escala de diferencial semântico e os analisamos estatisticamente por teste de hipóteses, além de fazermos entrevistas com os alunos. Os resultados sugerem que o método IpC impactou as crenças dos alunos positivamente, além de revelarem que o método EsM não teve a adesão esperada

    Targeted inhibition of RAGE in substantia nigra of rats blocks 6-OHDA-induced dopaminergic denervation

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    The receptor for advanced glycation endproducts (RAGE) is a pattern-recognition receptor associated with infammation in most cell types. RAGE up-regulates the expression of proinfammatory mediators and its own expression via activation of NF-kB. Recent works have proposed a role for RAGE in Parkinson’s disease (PD). In this study, we used the multimodal blocker of RAGE FPS-ZM1, which has become available recently, to selectively inhibit RAGE in the substantia nigra (SN) of rats intracranially injected with 6-hydroxydopamine (6-OHDA). FPS-ZM1 (40 μg per rat), injected concomitantly with 6-OHDA (10 μg per rat) into the SN, inhibited the increase in RAGE, activation of ERK1/2, Src and nuclear translocation of NF-kB p65 subunit in the SN. RAGE inhibition blocked glial fbrillary acidic protein and Iba-1 upregulation as well as associated astrocyte and microglia activation. Circulating cytokines in serum and CSF were also decreased by FPS-ZM1 injection. The loss of tyrosine hydroxylase and NeuN-positive neurons was signifcantly inhibited by RAGE blocking. Finally, FPS-ZM1 attenuated locomotory and exploratory defcits induced by 6-OHDA. Our results demonstrate that RAGE is an essential component in the neuroinfammation and dopaminergic denervation induced by 6-OHDA in the SN. Selective inhibition of RAGE may ofer perspectives for therapeutic approaches

    Polyclonal B-cell activation in human malaria: relevance to the development of anti-sporozoite specific immune response and of immunopathology in individuals from endemic areas (Rondonia State - Brazil)

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    Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Imunologia. Centro Colaborador da OMS para Pesquisa e Treinamento em Imunologia de Doenças Parasitárias. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Imunologia. Centro Colaborador da OMS para Pesquisa e Treinamento em Imunologia de Doenças Parasitárias. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Imunologia. Centro Colaborador da OMS para Pesquisa e Treinamento em Imunologia de Doenças Parasitárias. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Imunologia. Centro Colaborador da OMS para Pesquisa e Treinamento em Imunologia de Doenças Parasitárias. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Departamento de Imunologia. Centro Colaborador da OMS para Pesquisa e Treinamento em Imunologia de Doenças Parasitárias. Rio de Janeiro, RJ, Brasil
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