191 research outputs found
Feira de Ciências: uma experiência interdisciplinar na formação de professores de ciências das séries iniciais do ensino fundamental
O presente artigo se configura como um relato de experiência didática vivenciada por professores e alunos do Curso de Pedagogia da Universidade do Estado do Pará (UEPA). A experiência relatada diz respeito ao processo de planejamento, organização e realização de uma Feira de Ciências por duas turmas de 5º. Período de Pedagogia, sob a orientação das professoras das disciplinas Química e Biologia daquelas turmas. O evento, cujo tema central foi Ciência, Tecnologia e Meio ambiente, possibilitou a pesquisa, produção de material e socialização dos conhecimentos construídos acerca dos sub-temas associados a temática central, tendo sido percebido pelos sujeitos envolvidos no processo como de relevante significado para formação desses futuros profissionais da educação básica, na medida em que permitiu a vivência de uma prática interdisciplinar, além de promover articulação teórico-prática dos conteúdos trabalhado
An Intracellular Arrangement of Histoplasma capsulatum Yeast-Aggregates Generates Nuclear Damage to the Cultured Murine Alveolar Macrophages
Histoplasma capsulatum is responsible for a human systemic mycosis that primarily affects lung tissue. Macrophages are the major effector cells in humans that respond to the fungus, and the development of respiratory disease depends on the ability of Histoplasma yeast cells to survive and replicate within alveolar macrophages. Therefore, the interaction between macrophages and H. capsulatum is a decisive step in the yeast dissemination into host tissues. Although the role played by components of cell-mediated immunity in the host's defense system and the mechanisms used by the pathogen to evade the host immune response are well understood, knowledge regarding the effects induced by H. capsulatum in host cells at the nuclear level is limited. According to the present findings, H. capsulatum yeast cells display a unique architectural arrangement during the intracellular infection of cultured murine alveolar macrophages, characterized as a formation of aggregates that seem to surround the host cell nucleus, resembling a crown. This extranuclear organization of yeast-aggregates generates damage on the nucleus of the host cell, producing DNA fragmentation and inducing apoptosis, even though the yeast cells are not located inside the nucleus and do not trigger changes in nuclear proteins. The current study highlights a singular intracellular arrangement of H. capsulatum yeast near to the nucleus of infected murine alveolar macrophages that may contribute to the yeast’s persistence under intracellular conditions, since this fungal pathogen may display different strategies to prevent elimination by the host's phagocytic mechanisms
Bioética na pesquisa de engenharia biomédica : diminuição do uso de animais em experimentos científicos
Atividades de pesquisa utilizando animais são realizadas desde a antiguidade, o bem-estar do animal não era prioridade. Com a evolução da pesquisa, houve, também, a crescente preocupação com a ética e métodos que poderiam substituir o uso de cobaias animais nos experimentos científicos. Tal conscientização manifestou-se já no início do século XIX, na Inglaterra, com o surgimento de movimentos que se dedicavam a mudar as atitudes do homem em relação aos animais. Desde então, ativistas argumentam que métodos alternativos são capazes de substituir a utilização de animais em pesquisa, e que, por isso, a utilização de seres vivos é considerada como obsoleta. Por outro lado, alguns cientistas argumentam que a experimentação é o que traz frutos das pesquisas. O presente trabalho apresenta um levantamento de dissertações e teses defendidas no Instituto de Biologia da Universidade de Brasília no ano de 2017 que realizaram testes in vitro e in vivo além de trazer uma reflexão sobre o assunto e visa ressaltar as vantagens do uso de métodos alternativos. Para este estudo, foram utilizados artigos e dissertações das bases de dados CAPES e PubMed, bem como outras referências presentes neles. Concluiu-se que, embora não haja tecnologia suficiente para erradicar o uso de animais em experimentos, existem diversos métodos alternativos que não comprometem o estudo realizado
Lazer e recreação em unidade de clínica médica: o que pensam e sentem os pacientes participantes
Proposição de um sistema de produção de mudas de mandioquinha-salsa.
O objetivo desta publicação é trazer subsídios para a produção de mudas de alta qualidade genética, fitossanitária e fisiológica, com responsabilidade técnica, passíveis de certificação, em atendimento a demandas da cadeia produtiva e da sociedade como um todo. Assim, visa à melhoria do processo e da qualidade do produto, com consequente redução dos problemas fitossanitários e aumento na produtividade
IFNG +874T/A polymorphism is not associated with American tegumentary leishmaniasis susceptibility but can influence Leishmania induced IFN-γ production
<p>Abstract</p> <p>Background</p> <p>Interferon-gamma is a key cytokine in the protective responses against intracellular pathogens. A single nucleotide polymorphism (SNP) located in the first intron of the human IFN-γ gene can putatively influence the secretion of cytokine with an impact on infection outcome as demonstrated for tuberculosis and other complex diseases. Our aim was to investigate the putative association of IFNG+874T/A SNP with American tegumentary leishmaniasis (ATL) and also the influence of this SNP in the secretion of IFN-γ <it>in vitro</it>.</p> <p>Methods</p> <p>Brazilian ATL patients (78 cutaneous, CL, and 58 mucosal leishmaniasis, ML) and 609 healthy volunteers were evaluated. The genotype of +874 region in the IFN-γ gene was carried out by Amplification Refractory Mutational System (ARMS-PCR). <it>Leishmania</it>-induced IFN-γ production on peripheral blood mononuclear cell (PBMC) culture supernatants was assessed by ELISA.</p> <p>Results</p> <p>There are no differences between +874T/A SNP frequency in cases and controls or in ML versus CL patients. Cutaneous leishmaniasis cases exhibiting AA genotype produced lower levels of IFN-γ than TA/TT genotypes. In mucosal cases, high and low IFN-γ producers were clearly demonstrated but no differences in the cytokine production was observed among the IFNG +874T or A carriers.</p> <p>Conclusion</p> <p>Our results suggest that +874T/A polymorphism was not associated with either susceptibility or severity to leishmaniasis. Despite this, IFNG +874T/A SNP could be involved in the pathogenesis of leishmaniasis by influencing the amount of cytokine released by CL patients, although it could not prevent disease development. On the other hand, it is possible that in ML cases, other potential polymorphic regulatory genes such as TNF-α and IL-10 are also involved thus interfering with IFN-γ secretion.</p
Fulfillment of the Brazilian Agenda of Priorities in Health Research
This commentary describes how the Brazilian Ministry of Health's (MoH) research support policy fulfilled the National Agenda of Priorities in Health Research (NAPHR). In 2003, the MoH started a democratic process in order to establish a priority agenda in health research involving investigators, health managers and community leaders. The Agenda was launched in 2004 and is guiding budget allocations in an attempt to reduce the gap between scientific knowledge and health practice and activities, aiming to contribute to improving Brazilian quality of life. Many strategies were developed, for instance: Cooperation Agreements between the Ministry of Health and the Ministry of Science and Technology; the decentralization of research support at state levels with the participation of local Health Secretariats and Science and Technology Institutions; Health Technology Assessment; innovation in neglected diseases; research networks and multicenter studies in adult, women's and children's health; cardiovascular risk in adolescents; clinical research and stem cell therapy. The budget allocated by the Ministry of Health and partners was expressive: US$419 million to support almost 3,600 projects. The three sub-agenda with the higher proportion of resources were "industrial health complex", "clinical research" and "communicable diseases", which are considered strategic for innovation and national development. The Southeast region conducted 40.5% of all projects and detained 59.7% of the resources, attributable to the concentration of the most traditional health research institutes and universities in the states of São Paulo and Rio de Janeiro. The second most granted region was the Northeast, which reflects the result of a governmental policy to integrate and modernize this densely populated area and the poorest region in the country. Although Brazil began the design and implementation of the NAPHR in 2003, it has done so in accordance with the 'good practice principles' recently published: inclusive process, information gathering, careful planning and funding policy, transparency and internal evaluation (an external independent evaluation is underway). The effort in guiding the health research policy has achieved and legitimated an unprecedented developmental spurt to support strategic health research. We believe this experience is valuable and applicable to other countries, but different settings and local political circumstances will determine the best course of action to follow
Comparative cytogenetics of three species of Dichotomius (Coleoptera, Scarabaeidae)
Meiotic and mitotic chromosomes of Dichotomius nisus, D. semisquamosus and D. sericeus were analyzed after conventional staining, C-banding and silver nitrate staining. In addition, Dichotomius nisus and D. semisquamosus chromosomes were also analyzed after fluorescent in situ hybridization (FISH) with an rDNA probe. The species analyzed had an asymmetrical karyotype with 2n = 18 and meta-submetacentric chromosomes. The sex determination mechanism was of the Xyp type in D. nisus and D. semisquamosus and of the Xy r type in D. sericeus. C-banding revealed the presence of pericentromeric blocks of constitutive heterochromatin (CH) in all the chromosomes of the three species. After silver staining, the nucleolar organizer regions (NORs) were located in autosomes of D. semisquamosus and D. sericeus and in the sexual bivalent of D. nisus. FISH with an rDNA probe confirmed NORs location in D. semisquamosus and in D. nisus. Our results suggest that chromosome inversions and fusions occurred during the evolution of the group
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