455 research outputs found
Characterization of adult rat astrocyte cultures
Astrocytes, a major class of glial cells, regulate neurotransmitter systems, synaptic processing, ion homeostasis, antioxidant defenses and energy metabolism. Astrocyte cultures derived from rodent brains have been extensively used to characterize astrocytes’ biochemical, pharmacological and morphological properties. The aims of this study were to develop a protocol for routine preparation and to characterize a primary astrocyte culture from the brains of adult (90 days old) Wistar rats. For this we used enzymatic digestion (trypsin and papain) and mechanical dissociation. Medium exchange occurred from 24 h after obtaining a culture and after, twice a week up to reach the confluence (around the 4th to 5th week). Under basal conditions, adult astrocytes presented a polygonal to fusiform and flat morphology. Furthermore, approximately 95% the cells were positive for the main glial markers, including GFAP, glutamate transporters, glutamine synthetase and S100B. Moreover, the astrocytes were able to take up glucose and glutamate. Adult astrocytes were also able to respond to acute H2O2 exposure, which led to an increase in reactive oxygen species (ROS) levels and a decrease in glutamate uptake. The antioxidant compound resveratrol was able to protect adult astrocytes from oxidative damage. A response of adult astrocytes to an inflammatory stimulus with LPS was also observed. Changes in the actin cytoskeleton were induced in stimulated astrocytes, most likely by a mechanism dependent on MAPK and Rho A signaling pathways. Taken together, these findings indicate that the culture model described in this study exhibits the biochemical and physiological properties of astrocytes and may be useful for elucidating the mechanisms related to the adult brain, exploring changes between neonatal and adult astrocytes, as well as investigating compounds involved in cytotoxicity and cytoprotection
Pedagogical school vegetable gardens : an educational and nutritional concept
The purpose of this article is to present the project Implementation and conduction of technical-pedagogical gardens for schools in the states of Maranhão and Piauí, previously discussing the current framework of legal framework in Brazil on the Right to Adequate Food, Food and Nutrition Security and highlighting the relevance and main characteristics of a reference school garden. The proposed implementation of this project is a strategy for structuring gardening models in public education institutions that serve children and adolescents in the age group of 6 to 14 years. This is the initial step towards the consolidation of the School Vegetable Program for Improvement of Eating Habits, which aims to contribute to the process of a pedagogy aimed at the construction of healthy and sustainable eating habits
APOEε4 associates with microglial activation independently of Aβ plaques and tau tangles
Animal studies suggest that the apolipoprotein E ε4 (APOEε4) allele is a culprit of early microglial activation in Alzheimer’s disease (AD). Here, we tested the association between APOEε4 status and microglial activation in living individuals across the aging and AD spectrum. We studied 118 individuals with positron emission tomography for amyloid-β (Aβ; [18F]AZD4694), tau ([18F]MK6240), and microglial activation ([11C]PBR28). We found that APOEε4 carriers presented increased microglial activation relative to noncarriers in early Braak stage regions within the medial temporal cortex accounting for Aβ and tau deposition. Furthermore, microglial activation mediated the Aβ-independent effects of APOEε4 on tau accumulation, which was further associated with neurodegeneration and clinical impairment. The physiological distribution of APOE mRNA expression predicted the patterns of APOEε4-related microglial activation in our population, suggesting that APOE gene expression may regulate the local vulnerability to neuroinflammation. Our results support that the APOEε4 genotype exerts Aβ-independent effects on AD pathogenesis by activating microglia in brain regions associated with early tau deposition
Impact of the policies of scientific initiation and program science without borders in the access of students into Brazilian postgraduate programs
This article presents a description of Brazilian federal policies directed to improve the scientific experience of undergraduate students: the Institutional Programs of Scientific Initiation Scholarships (PIBIC), Technological Development and Innovation Scholarships (PIBITI) and the Science without Borders (SWB). Then it discusses an outcome of these governmental actions: the admittance of students into Brazilian Postgraduate Programs. The article emphasizes that such policies greatly contributed to the admittance of students into Brazilian Postgraduate Programs of higher academic quality and international recognition, compared to students that did not participate in those Brazilian federal policies. It means that PIBC, PIBITI and SWB are relevant instruments for training and qualifying human resources to scientific, technological and educational activities in Brazil
The changes in science and education conceptions in the occidental history : the scenario of these notions and their adaptations for the twenty first century
As concepções que temos de ciência e educação são historicamente construídas de acordo com especificidades conjunturais, passando ora por visões simplistas, ora por visões mais complexas. Passamos por mudanças de paradigmas científicos, onde atualmente Boaventura de Souza Santos fala do declínio do paradigma dominante de bases positivista e cartesiana, para o surgimento de um paradigma emergente baseado nas novas teorias da física, na superação da dicotomia entre ciências humanas e ciências naturais, e na busca da interdisciplinaridade. A educação também precisa passar por reconstruções conceituais e práticas, onde a escola deve superar a pedagogia baseada na fragmentação dos conteúdos e dos sujeitos, e na desvinculação com a realidade. A ciência cada vez mais caminha para novas estruturas, e consequentemente a educação deve reestruturarse visando acompanhar esse novo ser humano com sua nova forma de construir conhecimento científico.Existing scientific and educational concepts are constructed historically in accordance with situational specificities, experiencing changes through time, sometimes with simplistic perspectives, alternatively with ones more complex. Scientific paradigms are changing, as Boaventura de Souza Santos today refers to the decline of the dominant paradigm of positivism and Cartesian foundations and to the emergence of the paradigm based on new theories of physics, overcoming the dichotomy between human and natural sciences and the quest for interdisciplinarity. Education also needs to be transformed through conceptual and practical reinventions, where schools should go beyond a pedagogy based on content and subject fragmentation and disconnection with reality. That science progresses towards new structures; consequently, education must reinvent itself with the aim of accompanying this new human bein
Conceptual contributions reference to the Metropolitan planning in contemporary Brazil
A reestruturação das cidades do final do século XX é marcada por determinantes interurbanos e intraurbanos. A dinâmica das redes técnicas tende a substituir a estática dos lugares construídos, condicionando mentalidades e comportamentos urbanos; a interação dos indivíduos passa a ser reduzida e deslocalizada; o pertencimento a comunidades de interesses diversos não se funda mais nem sobre a proximidade nem sobre a densidade demográfica local. Nesse cenário, ocorre a aprovação do Estatuto da Metrópole, em janeiro de 2015, colocando as Regiões Metropolitanas (RMs) e Aglomerações Urbanas (AUs) brasileiras em lugar de destaque na agenda das ações sobre o urbano, exigindo uma maior compreensão sobre as novas lógicas de ocupação do território e suas relações com as atividades econômicas e sociais marcadas por redes e fluxos de alcances variados. A realidade metropolitana contemporânea nos conduz à necessidade de rever o conceito de região, bem como de pensar as novas centralidades urbanas.The urban restructuring in the late twentieth century is marked by intercity and intraurban determinatives. The dynamics of technical networks tends to replace the static places conditioning mentalities and urban behavior. The interaction between people becomes reduced and delocalized. Belonging to communities of diverse interests is no more based on proximity or even on the local demographic density. In that time is the approval of the metropolitain statute, in January 2015, that puts the Brazilian Metropolitan Regions (RMs) and Urban Agglomerations (AUs) in a prominent place on the urban agenda requiring a greater understanding of the new logic of occupation of the territory and its relations with the economic and social activities marked by networks and varied ranges of flows. The contemporary metropolitan reality leads us to review the concept of the region as well as centrality questions are placed
Cerebral Ketone Body Oxidation Is Facilitated by a High Fat Diet Enriched with Advanced Glycation End Products in Normal and Diabetic Rats.
Diabetes mellitus (DM) causes important modifications in the availability and use of different energy substrates in various organs and tissues. Similarly, dietary manipulations such as high fat diets also affect systemic energy metabolism. However, how the brain adapts to these situations remains unclear. To investigate these issues, control and alloxan-induced type I diabetic rats were fed either a standard or a high fat diet enriched with advanced glycation end products (AGEs) (HAGE diet). The HAGE diet increased their levels of blood ketone bodies, and this effect was exacerbated by DM induction. To determine the effects of diet and/or DM induction on key cerebral bioenergetic parameters, both ketone bodies (β-hydroxybutyric acid) and lactate oxidation were measured. In parallel, the expression of Monocarboxylate Transporter 1 (MCT1) and 2 (MCT2) isoforms in hippocampal and cortical slices from rats submitted to these diets was assessed. Ketone body oxidation increased while lactate oxidation decreased in hippocampal and cortical slices in both control and diabetic rats fed a HAGE diet. In parallel, the expression of both MCT1 and MCT2 increased only in the cerebral cortex in diabetic rats fed a HAGE diet. These results suggest a shift in the preferential cerebral energy substrate utilization in favor of ketone bodies in animals fed a HAGE diet, an effect that, in DM animals, is accompanied by the enhanced expression of the related transporters
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