Evolución del germen dental trasplantado heterotópicamente en la dermis: un estudio histológico en la rata

En este estudio hemos analizado la potencialidad de desarrollo del germen dental en fase de corona. Para ello, los gérmenes dentales de rata recién nacida fueron trasplantados en las bolsas dérmicas de la oreja de ratas isogénicas. Siete y catorce días después del trasplante, se desarrollaron las estructuras morfológicas dentales típicas, con ameloblastos y odontoblastos bien diferenciados. Ulteriormente, los procesos de reacción inflamatoria del tejido huésped con infiltración celular abocaron a la desaparición de los tejidos dentales. Desde el primer momento de nuestro análisis, los trasplantes desarrollaron una dentina anómala u osteoide cuyo tamaño fue paulatinamente incrementando con el tiempo, llegando a sustituir al resto de los tejidos dentales. Esta dentina osteoide, fruto tanto de la transformación de los odontoblastos del trasplante en células de alta actividad secretora como de la inducción que el germen dental ejerce en el tejido huésped circundante; y a diferencia de la observada en estudios previos, mostró diversos grados de polimerización fibrilar, lo que nos induce a sugerir que nuestro modelo puede ser un buen medio de estudiar los mecanismos de reacción en la formación de tejidos reactivos a la lesión dental.The main goal of this study was the analysis of the developmental potentiality of tooth germ from late bell stage on, after its heterotopic placement within the skin. Teeth germs of newborn rats were grafted within a skin pouch of the ear of adult rats. Seven to fourteen days after grafting, dental germs developed normal dental structures in which ameloblasts and odontoblasts were well differentiated. Twenty to forty-one days after graft, the inflammatory host reaction destroyed the dental developed tissues by cell infiltration. The dentin of the grafts was of osteoid characteristics, and its size increased dependinng on grafting time until the complete substitution of all dental tissues. This atypical dentin showed several degrees of polymerisation from collagen fibres smooth dentin devoid near the graft a to fibres rich dentin far from the dental germ. Present results suggest that this type of dental graft could be a valuable model to study the self-development of dental tissues and the reactive mechanisms taking place after dental injuries

Osteogenic potential of different chalcones in an in vivo model: A preliminary study

To evaluate the osteogenic potential of chalcones using the rat critical size calvarial defect. Methods. The chalcones were synthesized from acetophenone following the Claisen-Schmidt aldol condensation method by varying the substituted benzaldehydes (3,4-Cl; 4-Cl; 4-CH3; 4-OCH3, H). The five chalcone molecules were evaluated in three concentrations (1%, 5% and 10%) in comparison to control and vehicle (Vaseline) groups. The results of the remaining wound areas were calculated statistically by the ANOVA method followed by the Student-Newman-Keuls test and the histological sections were analyzed qualitatively by light microscopy. Results. All molecules at 10% concentration showed significant bone closure compared to the control, vehicle and chalcone groups at 1% concentration (p<0.01). Active osteoblasts were observed on the repair surfaces in all groups treated with chalcones. Treatment with the C5 molecule at concentration of a 10% resulted in greater bone neoformation compared to the other molecules, with features of secondary bone observed

Educação para a democracia no contexto neoliberal

O presente artigo de natureza bibliográfica objetiva aprofundar os desafios para a formação de sujeitos democráticos num contexto de hegemonia do pensamento neoliberal, que prima pela construção de subjetividades concorrenciais. Entende-se, aqui, o neoliberalismo para além dos pressupostos classicamente considerados de política econômica que defendem um Estado mínimo na economia e nas políticas socioeducacionais. As contribuições de Dardot e Laval (2016) ampliam os horizontes dessa compreensão e problematizam como os pressupostos neoliberais adentram as subjetividades e produzem novos modos de vida. Conceitos como neossujeito, empresário de si, concorrência, competição, entre outros, traduzem esses novos pressupostos. Buscando traduzir essa intenção, o artigo inicia com uma problematização geral de temática; reconstrói os principais argumentos de Dardot e Laval sobre a “nova razão do mundo”, em diálogo com autores como Sennett e Antunes; na sequência, aprofunda alguns pressupostos da educação escolar, visando à formação de sujeitos democráticos, especialmente com a contribuição de Biesta. Na conclusão, reafirma-se a tese de que somente uma educação democrática é capaz de qualificar os pressupostos de sociabilidade em vista de uma vida em comum

Potencialidades e limites político-educativos das mobilizações no Brasil: desafios de tradução

The aim of the current bibliographic article is to analyze challenges to the process of translating the political educational potentials and risks of social mobilizations in contemporary Brazil. Finding the best way to translate the potential and limits of social mobilizations, as well as their demands, shapes and political propositions, is a challenging task. The article addresses new forms of social mobilization; builds the diagnosis of diversity of expressions; makes an in-depth analysis of epistemic issues such as the concept of translation; and reinforces the hypothesis that mobilizations carried out from 2013 to 2016 were complex if one takes into consideration political educational potential and risks, based on the analytical perspective.El artículo de tipo bibliográfico analiza los desafíos para traducir las potencialidades y los riesgos políticos y educativos de las movilizaciones sociales en la contemporaneidad brasileña. El desafío es cómo traducir las potencialidades y los límites de las movilizaciones sociales, sus reivindicaciones, formatos y propuestas políticas. El artículo reflexiona sobre las nuevas formas de movilización social; construye un diagnóstico de la diversidad de expresiones; profundiza las cuestiones epistemológicas, incluido el concepto de traducción; y reafirma la tesis de que las movilizaciones de 2013 al 2016 son complejas desde el punto de vista analítico, así como de las potencialidades y los riesgos políticos y educativos.Le but de cet article bibliographique est celui d’analyser les défis de la traduction des potentialités et des risques politiques-éducatifs des mobilisations sociales à l’époque contemporaine brésilienne. Le défi est celui de savoir comment traduire les potentialités et les limites des mobilisations sociales, leurs demandes, leurs formats et leurs propositions politiques. L’article réfléchit aux nouvelles formes de mobilisation sociale; il construit un diagnostic de la diversité des expressions ; il approfondit les enjeux épistémiques tels que le concept de traduction ; et il réaffirme la thèse selon laquelle les mobilisations menées de 2013 à 2016 étaient complexes du point de vue analytique, ainsi que du point de vue des potentialités et des risques politiques-éducatifs.O artigo de natureza bibliográfica analisa os desafios para traduzir as potencialidades e os riscos políticos e educativos das mobilizações sociais na contemporaneidade brasileira. O desafio é como traduzir as potencialidades e os limites das mobilizações sociais, suas reivindicações, formatos e propostas políticas. O artigo faz uma reflexão sobre as novas formas de mobilização social; constrói um diagnóstico da diversidade de expressões; aprofunda questões epistêmicas, entre as quais, o conceito de tradução; e reafirma a tese de que as mobilizações de 2013 a 2016 são complexas do ponto de vista analítico, bem como das potencialidades e dos riscos políticos e educativos

Osteogenic potential of different chalcones in an in vivo model: A preliminary study.

Aim. To evaluate the osteogenic potential of chalcones using the rat critical size calvarial defect. Methods. The chalcones were synthesized from acetophenone following the Claisen-Schmidt aldol condensation method by varying the substituted benzaldehydes (3,4-Cl; 4-Cl; 4-CH3; 4-OCH3, H). The five chalcone molecules were evaluated in three concentrations (1%, 5% and 10%) in comparison to control and vehicle (Vaseline) groups. The results of the remaining wound areas were calculated statistically by the ANOVA method followed by the Student - Newman - Keuls test and the histological sections were analyzed qualitatively in by light microscopy. Results. All molecules at 10% concentration showed significant bone closure compared to the control, vehicle and chalcone groups at 1% concentration (p<0.01). Active osteoblasts were observed on the repair surfaces in all groups treated with chalcones. Treatment with the C5 molecule at concentration of 10% resulted in greater bone neoformation compared to the other molecules, with features of secondary bone observed. Conclusion. The chalcones evidenced a dose-dependent osteogenic potential and C5 was more effective in bone repair

Estudio de las características histofuncionales del germen dental heterotopicamente trasplantado en la rata adulta

El objetivo de este trabajo se centro en el análisis del desarrollo de los gérmenes dentales de molar de rata recién nacida (en estadio de campana) de un día de vida, tras su trasplante heterotópico en una área de influencia trigeminal no mandibular com

Avaliação da restrição alimentar e do treinamento físico sobre a memória e aprendizado em ratos diabéticos

Aim: To evaluate the influence of physical training and food restriction on learning and memory of diabetic rats. Materials and methods: Forty female Wistar rats, diabetic streptozotocin induced, were divided into 4 groups (n = 10 / group). The G1 corresponded to the control group and had free access to food and water. The G2 - Food Restriction group - received water ad libitum and feed restriction. The G3 to the swimming group that performed physical training for 10 minutes a day during the three weeks of the experiment. The G4 referred to the group Food Restriction + Swimming, which was submitted to the same methodological procedures of G2 and G3. In the twenty-first day the groups were evaluated in Inhibitory Dodge comparing the data by ANOVA followed by Tukey test. Results: The data showed a significant increase (p <0.01) in the time spent on the platform of the G2 group. For animals of G1, G3 and G4, although the platform length of stay was higher in the test session, the difference was not significant. Conclusions: The results of this study and according to the methodology used indicate that in diabetic animals, moderate food restriction (30%) improved performance on the learning and memory compared to the control animals and rats of swimming groups.Objetivos: Avaliar a influência do treinamento físico e da restrição alimentar sobre a memória e aprendizado em ratos diabéticos. Materiais e métodos: Quarenta ratos Wistar fêmeas, diabéticos, induzidos com estreptozotocina, foram divididos em 4 grupos (n=10/grupo). O G1 correspondeu ao grupo Controle e teve livre acesso a água e comida. O G2 - grupo Restrição Alimentar - recebeu água a vontade e restrição de ração. O G3 correspondeu ao grupo Natação que realizou treinamento físico por 10 minutos diários durante as 3 semanas do experimento. O G4 referiu-se ao grupo Restrição Alimentar + Natação, o qual foi submetido aos mesmos procedimentos metodológicos dos grupos G2 e G3. No vigésimo primeiro dia os grupos foram avaliados em Esquiva Inibitória comparando-se os dados pela ANOVA, seguido do teste Tukey. Resultados: Os dados indicaram um aumento significativo (p<0,01) no tempo de permanência na plataforma dos animais do grupo G2. Em relação aos animais dos grupos G1, G3 e G4, embora o tempo de permanência na plataforma tenha sido maior na sessão teste, a diferença não se mostrou significativa. Conclusões: Os resultados desse estudo e de acordo com a metodologia utilizada indicam que em animais diabéticos, a restrição alimentar moderada (30%) melhorou o desempenho quanto ao aprendizado e a memória, em comparação com os animais do grupo controle e aos ratos submetidos à natação

Transforming Growth Factor -ß1 (TGF-ß1) immunoreactivity in heterotopic grafts of adult dental apical papilla.

To analyze the expression of transforming growth factor-ß1 in heterotopic grafts of adult dental apical papilla. Methodology: The apical papilla of adult Wistar rats was grafted in the ear of the same donor rats 1, 3, 7 and 14 days after grafting, rats were perfused and the tissue containing the graft was processed for histological conventional technique and for immunohistochemical detection of transforming growth factor-ß1. Results: Heterotopically grafted apical papilla developed osteoid dentine. In an early post-grafting stage, odontoblast-like cells organized themselves in palisade and synthesized dentine. However, newly formed dentine possessed the structural appearance of reactive osteoid dentine, which was systematically destroyed by the activity of osteoclaste-like cells. Transforming Growth Factor-ß1 was observed in mesenchymal cells, extracellular matrix of the graft and surrounding host tissue, while odontoblast-like cells were systematically devoid of immunoreactivity. Conclusion: The different expression of transforming growth factor-ß1 between normal tissue and grafted tissue development suggests that in heterotopic graft conditions the inflammatory mediation of the transforming growth factor-ß1 prevails against its morphogenetic rol

Transforming Growth Factor-ß1 (TGF-ß1) immunoreactivity in heterotopic grafts of adult dental apical papilla.

Objetivo: Analizar la expresión del factor transformador del crecimiento-ß1 en trasplantes heterotópicos de papila dental del incisivo de la rata adulta. Metodología: La papila apical del incisivo de 12 ratas Wistar  adultas fue trasplantada en la oreja de las mismas ratas donantes, y perfundidas 1, 3, 7 y 14 días postrasplante. El tejido fue procesado para histología convencional y para la detección inmunohistoquímica del factor transformador del crecimiento-ß1. Resultados: La papila apical trasplantada  desarrolló osteodentina. En fases tempranas postrasplante se observaron células parecidas a los odontoblastos que se organizaron en empalizada y segregaron dentina que se depositó sobre su superficie apical o secretora. Esta dentina evolucionó a osteodentina caracterizada por perder su estructura tubular e incluir a las células odontoblásticas en lagunas de su matriz. Finalmente, la osteodentina presentó procesos líticos mediados por células de tipo osteoclasto. Durante todo el proceso la expresión del factor transformador del crecimiento-ß1 se restringió a las células mesenquimales, a la matriz del trasplante y a las zonas circundantes del huésped, estando ausente en los odontoblastos, a diferencia de lo que sucede durante la odontogénesis normal. Conclusión: La diferente localización de la expresión del Factor Transformador de crecimiento ß1 entre el tejido hospedero y el trasplantado sugieren que en condiciones de trasplante heterotópico de papila dental la mediación inflamatoria del Factor Transformador de crecimiento beta1 prevalece sobre su papel morfogenético.Objective: To analyze the expression of transforming growth factor-ß1 in heterotopic grafts of adult dental apical papillae. Methodology: Adult apical papillae of Wistar rats were grafted in the ear of the same donor rats. 1, 3, 7 and 14 days after grafting, rats were perfused and the tissue containing the graft was processed for histological conventional technique and for immunohistochemical detection of transforming growth factor-ß1. Results: Heterotopically grafted apical papilla developed osteoid dentine. In an early post-grafting stage, odontoblast-like cells organized themselves in palisade and synthesized dentine. However, newly formed dentine possessed the structural appearance of reactive osteoid dentine, which was systematically destroyed by the activity of osteoclaste-like cells. Transforming Growth Factor-ß1 was observed in mesenchymal cells, extracellular matrix of the graft and surrounding host tissue, while odontoblast-like cells were systematically devoid of immunoreactivity. Conclusion: The different expression of transforming growth factor-ß1 between normal tissue and grafted tissue development suggests that in heterotopic graft conditions the inflammatory mediation of the transforming growth factor-ß1 prevails against its morphogenetic role

Osteogenic potential of different chalcones in an in vivo model: A preliminary study.

Aim. To evaluate the osteogenic potential of chalcones using the rat critical size calvarial defect. Methods. The chalcones were synthesized from acetophenone following the Claisen-Schmidt aldol condensation method by varying the substituted benzaldehydes (3,4-Cl; 4-Cl; 4-CH3; 4-OCH3, H). The five chalcone molecules were evaluated in three concentrations (1%, 5% and 10%) in comparison to control and vehicle (Vaseline) groups. The results of the remaining wound areas were calculated statistically by the ANOVA method followed by the Student - Newman - Keuls test and the histological sections were analyzed qualitatively in by light microscopy. Results. All molecules at 10% concentration showed significant bone closure compared to the control, vehicle and chalcone groups at 1% concentration (p<0.01). Active osteoblasts were observed on the repair surfaces in all groups treated with chalcones. Treatment with the C5 molecule at concentration of 10% resulted in greater bone neoformation compared to the other molecules, with features of secondary bone observed. Conclusion. The chalcones evidenced a dose-dependent osteogenic potential and C5 was more effective in bone repair