31 research outputs found

    Learning through role-playing games: an approach for active learning and teaching

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    This study evaluates the use of role-playing games (RPGs) as a methodological approach for teaching cellular biology, assessing student satisfaction, learning outcomes, and retention of acquired knowledge. First-year undergraduate medical students at two Brazilian public universities attended either an RPG-based class (RPG group) or a lecture (lecture-based group) on topics related to cellular biology. Pre- and post-RPG-based class questionnaires were compared to scores in regular exams and in an unannounced test one year later to assess students' attitudes and learning. From the 230 students that attended the RPG classes, 78.4% responded that the RPG-based classes were an effective tool for learning; 55.4% thought that such classes were better than lectures but did not replace them; and 81% responded that they would use this method. The lecture-based group achieved a higher grade in 1 of 14 regular exam questions. In the medium-term evaluation (one year later), the RPG group scored higher in 2 of 12 questions. RPG classes are thus quantitatively as effective as formal lectures, are well accepted by students, and may serve as educational tools, giving students the chance to learn actively and potentially retain the acquired knowledge more efficiently.Avaliamos o uso dos role-plying games (RPGs) como uma metodologia de ensino e aprendizagem em Biologia Celular. Alunos do primeiro ano de Medicina participaram de aula expositiva tradicional (grupo referência) ou de aula com RPG (grupo RPG). Comparações foram feitas pela análise de questionários pré- e pós-aula com RPG, das notas nas provas regulares, e das notas obtidas em um teste aplicado um ano após a conclusão da disciplina. Dos 230 alunos que participaram das aulas com RPG, 78,4% responderam que o RPG é uma ferramenta eficaz na aprendizagem; 55,4% acharam que essas aulas são melhores que as aulas tradicionais, mas não as substituem; e 81% responderam que usariam essa metodologia. Os alunos do grupo referência tiveram nota maior em uma de 14 questões das provas regulares; os alunos do grupo RPG tiveram notas maiores em duas de 12 questões aplicadas um ano depois. Portanto, aulas com RPG foram tão eficientes quanto as aulas tradicionais (quantitativamente), são bem aceitas pelos estudantes, e podem ser uma metodologia que lhes dá a chance de aprender ativamente e, potencialmente, levar a uma melhor retenção do conhecimento aprendido.808

    In utero tracheal occlusion: surgical approach associated to steroid treatment increase VEGF (Vascular Endothelial Growth Factor) receptors in lungs of fetal rats

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    Background/Purpose: Congenital diaphragmatic hernia (CDH) presents with hypoplastic lungs and usually leads to pulmonary hypertension and high neonatal mortality. Fetal tracheal occlusion (TO) and prenatal corticotherapy are alternatives to accelerate fetal pulmonary growth and decrease hypoplasia in CDH. VEGF (Vascular Endothelial Growth Factor) production and surfactant production by type II pneumocytes are related with pulmonary maturityand are altered in CDH, but little has been described about VEGF receptors. Our objective was to quantify the receptors of VEGF (VEGFR) and type II pneumocytes, verifying the effects of TO and corticotherapy on normal lungs of fetal rats. Methods: Six groups of 12 Spreague-Dawley rat fetuses (gestation=22 days) were compared:TO, S (sham), C (control), TO+Dex, S+Dex and C+Dex. On the 18.5 gestational day, TO was performed with and without corticotherapy, using dexamethasone. On the 21.5 gestational daybody and lung weights were measured. Immunohistochemistry was carried out for VEGFR-1(Flt-1) and VEGFR-2 (Flk-1), as well as anti-SP-A, microscopic analysis and quantification of immune system marking. Results: Body weight decreased in Sham and lung weight increased in TO and TO+Dex (p<0.05) groups. VEGFR-1 and VEGFR-2 increased in TO and in TO+Dex (p<0.05). Type II pneumocytes (SP-A) decreased both in the TO and in TO+Dex groups in comparison with the Control groupin absolute value (p<0.05), with no differences in relative value to total cell count. Conclusion: TO in association with the use of corticosteroids increased VEGFR-1 and VEGFR-2, while the quantity of type II pneumocytes (SP-A) decreased in relation to the area considered, but not in relation to the total of pulmonary cells.Introdução: A hérnia diafragmática congênita (HDC) causa hipoplasia e hipertensão pulmonar e em geral leva a alta morbidade e mortalidade neonatal. Traqueo-oclusão fetal (TO) e corticoterapia pré-natal são alternativas para acelerar o crescimento pulmonar fetal e diminuir a hipoplasia na HDC. A produção de VEGF (Vascular Endothelial Growth Factor) está relacionada com a maturidade pulmonar e sofre alterações na HDC ainda não elucidadas. Materiais e métodos: Seis grupos de 12 fetos de ratos Spreague-Dawley foram comparados: TO, Sham, Controle, TO+Dex, Sham+Dex e Controle+Dex. No dia 18,5º foi realizada TO com e sem corticoterapia utilizando dexametasona. No 21,5º dia gestacional os pesos corporal e pulmonar foram mensurados. Realizou-se imunohistoquímica para VEGFR-1 (Flt-1), VEGFR-2 (Flk-1), seguida de morfometria. Resultados: O VEGFR-1 estava aumentado no TO (p<0.05)e na TO+Dex (p<0.05). O VEGFR-2 teve aumento significativo quando comparamos TO e TO+Dex com o controle (p<0,05). Conclusão: A TO associada ao uso de corticoesteróide aumentou o número de VEGFR-1 e VEGFR-2 em pulmões de fetos de ratas

    The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

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    Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age  6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score  652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

    Organização molecular no sistema quitinoso das conchas resquiciais de Loligo brasiliensis

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    Orientador : Benedicto de Campos VidalDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: o sistema quitinoso da concha resquicial de Loligo brasiliensis foi estudado através de eletroforese em poliacrilamida, de testes topoquímicos e da microscopia de polarização. O material mostra-se intensamente reativo aos xylidine ponceau, sirius rede picrosírius, bem como apresenta incrementos na birrefringincia e intenso dicroísmo linear quando examinados sob luz polarizada, o que demonstra a existência de ordenação molecular do componente protéico associado à quitina. O material responde positivamente aos Congo red e PAS e reage fracamente com o azul de alcian e o azul de toluidina. A eletroforese em poliacrilamida demonstrou a existencia de pelo menos 10 componentes glicoprotéicos associados de forma não covalente à quitina. Alguns destes componentes formam complexos estabilizados por pontes dissulfeto. Curvas de birrefringência de forma construídas para cortes histológicos demostraram a existincia de maiores cristalinidade e agregação lateral das fíbrilas de quitina após hidrolise alcalina, o que faz supor que as proteínas atuem mantendo certo afastamento entre os componentes fibrilares, atribuindo plasticidade ao sistema, além de reduzir sua susceptibilidade a hidratação e à degradação enzimaticaAbstract: The chitin system of Loligo brasiliensis pen was studied through electrophoresis, topochemical tests i}nd polarization microscop Pen sectionspresent intense reactivity to xylidine ponceau, sirius red and picrosirius stains, as well as exhibit increases in birefringence and conspicuous extrinsic linear dichroism under polarized light, what suggests on the existence of molecular ordering in the association of the protein moiet to chitin. 0positive responses to Congo red and PAS beside weak reaction to alcian blue and toluidine blue were a150 demonstrated. SDS-polyacrylamide gel electrophoresis highlighted the presence of at least 10 gl_coprotein5 associated non-covalentl to chitin, some of them making up disulfide-bonded complexes. Form birefringence curves constructed with retardatlon measurements showed that hydrolised pen has higher crystallinity and lateral aggregation of chitin fibrils. This fact support lhe assumption that proteins act maintaining apart the fibrillar components and ascy"ibe plasticity and resistence to hidration and enzymatic degradation to this systemMestradoBiologia CelularMestre em Ciências Biológica

    Estrutura e composição de um tendão sujeito a forças de compressão

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    Orientador: Benedicto de Campos VidalTese (doutorado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: O tendão do músculo plantaris longus de da rã-touro (Rana catesbeiana) está sujeito a forças de compressão, de torsão e de fricção, em adição às forças de tensão exercidas pelo músculo. Este trabalho visou caracterizar as adaptações estruturais e composicionais apresentadas por este tendão frente a este complexo sistema biomecânico. Estruturalmente duas regiões principais foram delimitadas, uma região de tensão, tipicamente fibrosa e tida como responsável pela transmissão das forças de tensão, e uma região de compressão, de aspecto cartilaginoso, que se desenvolve na área em que o tendão contorna a articulação tibio-fibular distal. A região de compressão distingue-se do aspecto fibrocartilaginoso descrito para tendões de mamíferos encontrados em situações semelhantes e apresenta feixes primários e fibras extremamente onduladas e/ou contorcidas, na superfície dos quais deposita-se um material basofílico caracterizado como proteoglicanos. Ultraestruturalmente estes feixes apresentam -se formados por fibrilas associadas em grupos independentes que à semelhança dos feixes que formam são também contorcidas e sem direcionamento predominante. Afixação em presença de vermelho de rutênio faz com que os proteoglicanos precipitem-se como grânulos interligados por filamentos que formam estruturas aneladas. Além destes componentes encontrados nos espaços interfibrilares, existem grânulos que são encontrados em associação com as fibrilas de colágeno e distribuídos de forma periódica de acordo com o perído d. A comparação dos tamanhos destes grânulos na região de compressão com aqueles observados na região de tensão demonstra que os primeiros são bem maiores que os últimos. Estudo morfométrico revelou que as fibrilas de colágeno da região de compressão apresentam diâmetros reduzidos e com distribuição de valores menos ampla que a região de tensão. As células da região de compressão podem ser distinguidas em três tipos, principalmente pelo conteúdo de filamentos intermediários que acumulam no citoplasma e no tipo de interação com componentes da matriz extracelular. Foi demonstrado que a região de compressão possui cerca de 7 vezes mais glicosaminoglicanos (quantificados pelo método do carbazol) que a região de tensão e que parte destes componentes estão associados na formação de grandes proteoglicanos, como revelado por filtração em gel de Sepharose CL-4B, eletroforese em gel de agarose-acrilamida e por ultracentrifugação em gradiente de cloreto de césio. Também os pequenos proteoglicanos foram identificados, sendo que o biglicam é encontrado na região de compressão e está virtualmente ausente da região de tensão, onde o decorim apresenta tamanho reduzido provavelmente por menor extensão do seu glicosaminoglicano. O menor tamanho do decorim é demonstrado também pela dimensão reduzida dos grânulos associados às fibrilas de colágeno que são revelados pelo vermelho de rutênio. Fibromodulim foi identificado nas duas regiões sem apresentar modificações estruturais evidentes entre elas. Foi demonstrado que o colágeno do tipo I é o principal componente das duas regiões do tendão, embora a presença de outros componentes de natureza colagênica tenha sido sugerida pela existência de fragmentos distintos obtidos por digestão com pepsina de material proveniente de cada região e por precipitação diferencial de colágenos, com conteúdo em aminoácidos diferente daquele apresentado pelo colágeno do tipo I. As análises efetuadas permitem concluir que este tendão possui grande capacidade de deformação, possibilitada pelo arranjo dos elementos fibrilares e pelo conteúdo em grandes proteoglicanos, além da esperada resistência à compressão, comuns a outros tendões sujeitos a forças de compressãoAbstract: The tendon of muscle plantaris longus of Rana catesbeiana is subjected to compressive, torsional and frictional forces in addition to the tension forces exerted by the muscle. This work was carried out to characterize the structural and compositional features of the tendon facing this complex biomechanical system. Two main regions can be distinguished structurally. The tension region, typically fibrous and assumed to be responsible for the transmission of tension forces, and the compression region. with cartilaginous aspect, which develops in the area where the tendon wraps the distal tibial joint. At histologicallevel, the compression region differs from the fibrocartilaginous array described for mammalian tendons under compression and exhibits primary bundles and fibers extremely wavy and convoluted, with an coarse covering of basophilic material identified as proteoglycans. Ultrastructurally, these bundles are constituted by independent groups of convoluted fibrils without a predominant direction. Fixation in presence of ruthenium red precipitates the proteoglycans as granules associated by filaments in ring formations. Besides these granules of the interfibrillar spaces, there are granules associated with the collagen fibril surface and disposed periodically according to the d period. Comparison of the size of these granules in the compression regions with those of the tension regions demonstrated that the former are larger than the latter granules. A morphometric study demonstrated that the fibrils of the compression region show reduced diameters with a narrow distribution of values while fibrils of the tension region exhibit a wide dispersion of values reaching extremely large diameters. Cells of the compression region can be distinguished in three main types, differing essentialIy by the amount of intermediate filaments deposited in the cytoplasm and in the kind of association with extracellular matrix components. Biochemical analysis demonstrated that the compression region possess almost 7 times the amount of glycosaminoglycans found in the tension region. Part of these glycosaminoglycans are in the form of large proteoglycans as demonstrated by gel filtration in Sepharose CL-4B, composite agarose-acrylamide gel eletrophoresis, and ultracentrifugation in cesium chloride gradient. DEAE-cellulose chromatography of material extracted by 4M GuCl unveil the existence of small proteoglycans in both region of the tendon. eventhough biglycan is virtually absent of the tension region and that decorim from this region migrates faster in SDS-PAGE, pointing to its smaller size. It agrees with the smaller size offibril-associated granules revealed by fixation in presence of ruthenium red. Fibromodulim was also identified in both regions without remarkable structural modifications. Is was shown that collagen type I is the main collagenous component of both regions, though other members of the family must be present as indicated by differences in fragments obtained by digestion with pepsin and by obtention of residues of collagenous material other than type I in differential precipitation by NaCl from neutraI saline. The analysis allow us to conclude that this tendon has an increased deformability, which is guaranteed by the spacial arrangement of fibrillar components as welI as by the content in large proteoglycans, besides the expected capacity to resist compressive forces, shared with different pressure-bearing tendonsDoutoradoBioquimicaDoutor em Ciências Biológica

    Learning through role-playing games: an approach for active learning and teaching

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    This study evaluates the use of role-playing games (RPGs) as a methodological approach for teaching cellular biology, assessing student satisfaction, learning outcomes, and retention of acquired knowledge. First-year undergraduate medical students at two Brazilian public universities attended either an RPG-based class (RPG group) or a lecture (lecture-based group) on topics related to cellular biology. Pre- and post-RPG-based class questionnaires were compared to scores in regular exams and in an unannounced test one year later to assess students' attitudes and learning. From the 230 students that attended the RPG classes, 78.4% responded that the RPG-based classes were an effective tool for learning; 55.4% thought that such classes were better than lectures but did not replace them; and 81% responded that they would use this method. The lecture-based group achieved a higher grade in 1 of 14 regular exam questions. In the medium-term evaluation (one year later), the RPG group scored higher in 2 of 12 questions. RPG classes are thus quantitatively as effective as formal lectures, are well accepted by students, and may serve as educational tools, giving students the chance to learn actively and potentially retain the acquired knowledge more efficiently

    Control of Surface Properties of Hyaluronan/Chitosan Multilayered Coatings for Tumor Cell Capture

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    Prostate cancer (PCa) is a slow-growing neoplasm that has, when diagnosed in its early stages, great chances of cure. During initial tumor development, current diagnostic methods fail to have the desired accuracy, thus, it is necessary to develop or improve current detection methods and prognostic markers for PCa. In this scenario, films composed of hyaluronic acid (HA) and chitosan (CHI) have demonstrated significant capture potential of prostate tumor cells (PC3 line), exploring HA as a CD44 receptor ligand and direct mediator in cell-film adhesion. Here, we present a strategy to control structural and cell adhesion properties of HA/CHI films based on film assembly conditions. Films were built via Layer-by-layer (LbL) deposition, where the pH conditions (3.0 and 5.0) and number of bilayers (3.5, 10.5, and 20.5) were controlled. The characterization of these films was carried out using profilometry, ultraviolet-visible (UV-VIS), atomic force microscopy (AFM) and contact angle measurements. Multilayer HA/CHI films produced at pH 3.0 gave optimum surface wettability and availability of free carboxyl groups. In turn, at pH 5.0, the coverings were thinner and presented a smoother surface. Films prepared with 3.5 bilayers showed greater tumor cell capture regardless of the pH condition, while films containing 10.5 and 20.5 bilayers presented a significant swelling process, which compromised their cell adhesion potential. This study shows that surface chemistry and morphology are critical factors for the development of biomaterials designed for several cell adhesion applications, such as rapid diagnostic, cell signaling, and biosensing mechanisms
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