73 research outputs found
Avaliação da performance de diferentes plásticos usados para selar arranjos de cDNA em náilon
cDNA arrays are a powerful tool for discovering gene expression patterns. Nylon arrays have the advantage that they can be re-used several times. A key issue in high throughput gene expression analysis is sensitivity. In the case of nylon arrays, signal detection can be affected by the plastic bags used to keep membranes humid. In this study, we evaluated the effect of five types of plastics on the radioactive transmittance, number of genes with a signal above the background, and data variability. A polyethylene plastic bag 69 μm thick had a strong shielding effect that blocked 68.7% of the radioactive signal. The shielding effect on transmittance decreased the number of detected genes and increased the data variability. Other plastics which were thinner gave better results. Although plastics made from polyvinylidene chloride, polyvinyl chloride (both 13 μm thick) and polyethylene (29 and 7 μm thick) showed different levels of transmittance, they all gave similarly good performances. Polyvinylidene chloride and polyethylene 29 mm thick were the plastics of choice because of their easy handling. For other types of plastics, it is advisable to run a simple check on their performance in order to obtain the maximum information from nylon cDNA arrays.Os arranjos de cDNA são uma poderosa ferramenta para o estudo de padrões de expressão gênica. Os arranjos em membranas de náilon apresentam ainda a vantagem de poderem ser reutilizados diversas vezes. Porém, um ponto bastante delicado em estudos de expressão gênica em larga escala é a sensibilidade. No caso de arranjos em membranas de náilon, a detecção dos sinais pode ser afetada pelo envoltório plástico utilizado para manter as membranas úmidas. Nesse estudo, nós avaliamos os efeitos de cinco tipos de plásticos na transmissão radioativa detectada, no número de genes com sinal acima da emissão de fundo e na variabilidade dos dados. O plástico produzido com polietileno com 69 μm de espessura apresentou uma forte interferência na emissão radioativa, bloqueando 68.7% do sinal detectado. Este bloqueio na transmitância diminuiu o numero de genes detectados e aumentou a variabilidade dos dados. Outros plásticos mais finos tiveram resultados melhores. Apesar de plásticos feitos de cloreto de polivinilideno e cloreto de polivinila (ambos com 13 μm de espessura) e polietileno (29 e 7 μm de espessura) terem diferentes níveis de transmitância, todos apresentaram performances semelhantes nos testes realizados. Cloreto de polivinilideno e polietileno com 29 μm de espessura foram os plásticos escolhidos devido à facilidade de manuseio. Para outros tipos de plásticos, é recomendável realizar um teste de suas performances antes de utilizá-los para envolver membranas de náilon, de forma a obter o máximo de informação dos experimentos com arranjos de cDNA.18831887Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES
Estudos baseados na prática para uma aprendizagem baseada em competências
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Faced with the existing gap in formal education regarding the dissonance between learning and competence development, the objective of this article is to investigate how the "Teaching Case" method corroborates Practice-Based Research, placing practice as a priority for understanding of students' learning and skills development. The study demonstrates the contribution of the Inspirational Teaching Case method to the teaching-learning process according to four categories: practical learning; theories subordinated to practice; interesting challenge and engagement. The research results indicate that the Teaching Case allows articulating the four categories and that this articulation contributes to competence-based learning.Diante da lacuna existente no ensino formal quanto à dissonância entre a aprendizagem e o desenvolvimento de competências, investigou-se como o método caso de ensino corrobora com os estudos baseados na prática, colocando a prática como prioritária para a compreensão da aprendizagem e do desenvolvimento de competências dos alunos. O estudo demonstra a contribuição do método Caso de Ensino Inspiracional para o processo de ensino-aprendizagem de acordo com quatro categorias: aprendizagem prática; teorias subordinadas à prática; desafio interessante e engajamento. Os resultados indicam que o caso de ensino permite articular as quatro categorias e que esta articulação contribui para uma aprendizagem baseada em competências
Accuracy, precision and robustness of different methods to obtain samples from silages in fermentation studies
Transição paradigmática na educação médica: um olhar construtivista dirigido à aprendizagem baseada em problemas
A Reassessment of the in vitro total protein content determination (TPC) with SIRC and 3T3 cells for the evaluation of the ocular irritation potential of shampoos: comparison with the in vivo Draize rabbit test
Determination of eye irritation potential of low-irritant products: comparison of in vitro results with the in vivo draize rabbit test
ESTERILIZAÇÃO QUÍMICA E AGENTES GELEIFICANTES ALTERNATIVOS NA PROPAGAÇÃO VEGETATIVA IN VITRO DO ABACAXIZEIRO ‘VITÓRIA’
The germline mutational landscape of BRCA1 and BRCA2 in Brazil
The detection of germline mutations in BRCA1 and BRCA2 is essential to the formulation of clinical management strategies, and in Brazil, there is limited access to these services, mainly due to the costs/availability of genetic testing. Aiming at the identification of recurrent mutations that could be included in a low-cost mutation panel, used as a first screening approach, we compiled the testing reports of 649 probands with pathogenic/likely pathogenic variants referred to 28 public and private health care centers distributed across 11 Brazilian States. Overall, 126 and 103 distinct mutations were identified in BRCA1 and BRCA2, respectively. Twenty-six novel variants were reported from both genes, and BRCA2 showed higher mutational heterogeneity. Some recurrent mutations were reported exclusively in certain geographic regions, suggesting a founder effect. Our findings confirm that there is significant molecular heterogeneity in these genes among Brazilian carriers, while also suggesting that this heterogeneity precludes the use of screening protocols that include recurrent mutation testing only. This is the first study to show that profiles of recurrent mutations may be unique to different Brazilian regions. These data should be explored in larger regional cohorts to determine if screening with a panel of recurrent mutations would be effective.This work was supported in part by grants from Barretos Cancer Hospital (FINEP - CT-INFRA, 02/2010), Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, 2013/24633-2 and 2103/23277-8), Fundação de Apoio à Pesquisa do Rio Grande do Norte (FAPERN), Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS), Ministério da Saúde, the Breast Cancer Research Foundation (Avon grant #02-2013-044) and National Institute of Health/National Cancer Institute (grant #RC4 CA153828-01) for the Clinical Cancer Genomics Community Research Network. Support in part was provided by grants from Fundo de Incentivo a Pesquisa e Eventos (FIPE) from Hospital de Clínicas de Porto Alegre, by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, BioComputacional 3381/2013, Rede de Pesquisa em Genômica Populacional Humana), Secretaria da Saúde do Estado da Bahia (SESAB), Laboratório de Imunologia e Biologia Molecular (UFBA), INCT pra Controle do Câncer and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). RMR and PAP are recipients of CNPq Productivity Grants, and Bárbara Alemar received a grant from the same agencyinfo:eu-repo/semantics/publishedVersio
Immune and inflammatory responses to Leishmania amazonensis isolated from different clinical forms of human leishmaniasis in CBA mice
Leishmania amazonensis causes different diseases depending on the host and parasitic virulence factors. In this study, CBA mice were infected with L. amazonensis isolates from patients with localized (Ba125), diffuse cutaneous (Ba276) or visceral leishmaniasis (Ba109). Mice infected with Ba125 and Ba276 progressed rapidly and lesions displayed an infiltrate rich in parasitized macrophages and were necrotic and ulcerated. Ba109 induced smaller lesions and a mixed inflammatory infiltrate without necrosis or ulceration. Ba109 induced an insidious disease with lower parasite load in CBA mice, similar to human disease. Levels of IFN-γ, IL-4 and IL-10 did not differ among the groups. Because all groups were unable to control the infection, expression of IL-4 associated with low production of IFN-γ in the early phase of infection may account for susceptibility, but others factors may contribute to the differences observed in inflammatory responses and infection progression. Evaluation of some parasitic virulence factors revealed that Ba276 exhibits higher ecto-ADPase and 5'-nucleotidase activities compared to the Ba109 and Ba125 strains. Both Ba276 and Ba125 had higher arginase activity in comparison to Ba109. Finally, these data suggest that the differences in enzyme activities among parasites can account for differences in host inflammatory responses and infection progression
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