Analogias e a didática fundamental: um diálogo possível em sala de aula de administração mediada por jogos empresariais?

O presente texto é parte de uma dissertação de mestrado e apresenta um estudo comparativo entre o uso de analogias em sala de aula, por meio de uma metodologia de ensino com analogias e aspectos da didática fundamental. Considera como ponto inicial para análise a compreensão de que os processos de ensino e de aprendizagem ocorrem sob a perspectiva de três dimensões que envolvem o contexto educacional: dimensões técnica, político-social e humana. As duas propostas são comparadas, destacando os pontos em comum entre elas. A pesquisa de campo foi aplicada em sala de aula de Administração de Empresas com a interveniência de Jogos Empresariais. Os resultados indicam possibilidades de diálogo entre o uso sistematizado de analogias e a didática fundamental para a melhoria do processo de ensino e aprendizagem em aulas mediadas por jogos empresariais

Periostin as a modulator of chronic cardiac remodeling after myocardial infarction

OBJECTIVE: After acute myocardial infarction, during the cardiac repair phase, periostin is released into the infarct and activates signaling pathways that are essential for the reparative process. However, the role of periostin in chronic cardiac remodeling after myocardial infarction remains to be elucidated. Therefore, the objective of this study was to investigate the relationship between tissue periostin and cardiac variables in the chronic cardiac remodeling induced by myocardial infarction. METHODS: Male Wistar rats were assigned to 2 groups: a simulated surgery group (SHAM; n = 8) and a myocardial infarction group (myocardial infarction; n = 13). After 3 months, morphological, functional and biochemical analyses were performed. The data are expressed as means±SD or medians (including the lower and upper quartiles). RESULTS: Myocardial infarctions induced increased left ventricular diastolic and systolic areas associated with a decreased fractional area change and a posterior wall shortening velocity. With regard to the extracellular matrix variables, the myocardial infarction group presented with higher values of periostin and types I and III collagen and higher interstitial collagen volume fractions and myocardial hydroxyproline concentrations. In addition, periostin was positively correlated with type III collagen levels (r = 0.673, p = 0.029) and diastolic (r = 0.678, p = 0.036) and systolic (r = 0.795, p = 0.006) left ventricular areas. Considering the relationship between periostin and the cardiac function variables, periostin was inversely correlated with both the fractional area change (r = -0.783, p = 0.008) and the posterior wall shortening velocity (r = -0.767, p = 0.012). CONCLUSIONS: Periostin might be a modulator of deleterious cardiac remodeling in the chronic phase after myocardial infarction in rats

Analogias e a didática fundamental : um diálogo possível em sala de aula de administração mediada por jogos empresariais?

O presente texto é parte de uma dissertação de mestrado e apresenta um estudo comparativo entre o uso de analogias em sala de aula, por meio de uma metodologia de ensino com analogias e aspectos da didática fundamental. Considera como ponto inicial para análise a compreensão de que os processos de ensino e de aprendizagem ocorrem sob a perspectiva de três dimensões que envolvem o contexto educacional: dimensões técnica, político-social e humana. As duas propostas são comparadas, destacando os pontos em comum entre elas. A pesquisa de campo foi aplicada em sala de aula de Administração de Empresas com a interveniência de Jogos Empresariais. Os resultados indicam possibilidades de diálogo entre o uso sistematizado de analogias e a didática fundamental para a melhoria do processo de ensino e aprendizagem em aulas mediadas por jogos empresariais

Analogias e a didática fundamental : um diálogo possível em sala de aula de administração mediada por jogos empresariais?

O presente texto é parte de uma dissertação de mestrado e apresenta um estudo comparativo entre o uso de analogias em sala de aula, por meio de uma metodologia de ensino com analogias e aspectos da didática fundamental. Considera como ponto inicial para análise a compreensão de que os processos de ensino e de aprendizagem ocorrem sob a perspectiva de três dimensões que envolvem o contexto educacional: dimensões técnica, político-social e humana. As duas propostas são comparadas, destacando os pontos em comum entre elas. A pesquisa de campo foi aplicada em sala de aula de Administração de Empresas com a interveniência de Jogos Empresariais. Os resultados indicam possibilidades de diálogo entre o uso sistematizado de analogias e a didática fundamental para a melhoria do processo de ensino e aprendizagem em aulas mediadas por jogos empresariais

Dexamethasone-induced insulin resistance is associated with increased connexin 36 mRNA and protein expression in pancreatic rat islets

Augmented glucose-stimulated insulin secretion (GSIS) is an adaptive mechanism exhibited by pancreatic islets from insulin-resistant animal models. Gap junction proteins have been proposed to contribute to islet function. As such, we investigated the expression of connexin 36 (Cx36), connexin 43 (Cx43), and the glucose transporter Glut2 at mRNA and protein levels in pancreatic islets of dexamethasone (DEX)-induced insulin-resistant rats. Study rats received daily injections of DEX (1 mg/kg body mass, i.p.) for 5 days, whereas control rats (CTL) received saline solution. DEX rats exhibited peripheral insulin resistance, as indicated by the significant postabsorptive insulin levels and by the constant rate for glucose disappearance (K-ITT). GSIS was significantly higher in DEX islets (1.8-fold in 16.7 mmol/L glucose vs. CTL, p < 0.05). A significant increase of 2.25-fold in islet area was observed in DEX vs. CTL islets (p < 0.05). Cx36 mRNA expression was significantly augmented, Cx43 diminished, and Glut2 mRNA was unaltered in islets of DEX vs. CTL (p < 0.05). Cx36 protein expression was 1.6-fold higher than that of CTL islets (p < 0.05). Glut2 protein expression was unaltered and Cx43 was not detected at the protein level. We conclude that DEX-induced insulin resistance is accompanied by increased GSIS and this may be associated with increase of Cx36 protein expression

The adaptive compensations in endocrine pancreas from glucocorticoid-treated rats are reversible after the interruption of treatment

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Aim: Glucocorticoid administration induces insulin resistance (IR) and enhances islet mass and insulin secretion in rodents and humans. Here, we analysed whether these effects are still present after the interruption of dexamethasone treatment. Methods: Adult Wistar rats were distributed into CTL (daily injection of saline for five consecutive days), DEX (daily injection of 1 mg kg-1 body wt of dexamethasone for five consecutive days) and DEX10 (5 days of dexamethasone treatment, followed by a period of 10 days without dexamethasone). Results: In vivo experiments indicated that the marked hyperinsulinemia found in DEX rats during fasting and fed states was normalized in the DEX10 group. Furthermore, the IR and glucose intolerance observed in DEX were restored in DEX10 rats. Islets from DEX rats secreted more insulin in response to increasing concentrations of glucose and other metabolic and non-metabolic stimuli, compared with that in the CTL group. The insulin secretion for the most compounds studied returned to CTL values in DEX10 islets. Increased insulin secretion correlated well with the augmentation in beta-cell proliferation and mass in DEX rats, and these morphological alterations were normalized in islets from DEX10 rats. In parallel, the increased levels of proteins involved in beta-cell proliferation such as Cd2 and Cdk4 observed in DEX islets were also normalized in DEX10 islets. Conclusion: These data strongly support the view that almost all the morphophysiological alterations induced by dexamethasone in the endocrine pancreas are reverted after discontinuation of the treatment. This information is important, considering the frequent use of glucocorticoids in humans.2003223235Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)INOD (Instituto Nacional de Obesidade e Diabetes)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Cellular changes in the prostatic stroma of glucocorticoid-treated rats

Glucocorticoid hormones (GCs) have been widely used for the treatment of prostate cancer because of their inhibitory property against tumour growth. However, their mechanism of action in the prostate has received little attention. Excess GCs can lead to peripheral insulin resistance resulting in hyperglycaemia and hyperinsulinaemia. Insulin plays an important role as a cellular stimulant and high levels are related to low levels of androgens. Our objective has been to describe the effects of insulin resistance induced by dexamethasone treatment on the morphology of rat ventral prostate. Mate adult Wistar rats received daily intraperitoneal injections of dexamethasone or saline for five consecutive days after which the rats were killed and the ventral prostate was removed, weighed and prepared for conventional and transmission electron microscopy (TEM). Dexamethasone treatment resulted in atrophy and decreased proliferative activity of prostatic epithelial cells. TEM analysis revealed changes in the epithelium-stroma interface, with some interruptions in the basement membrane. Fibroblasts showed a secretory phenotype with dilated endoplasmic reticulum. Smooth muscle cells exhibited a contractile pattern with 50% atrophy, an irregular membrane and twisted nuclei. Mitochondrial alterations, such as enlarged size and high electron density in the mitochondrial matrix, were also detected in smooth muscle cells. Insulin resistance induced by dexamethasone is thus associated with epithelial atrophy similar to that described for diabetic rats. However, GCs are responsible for morphological changes in the stromal cell population suggesting the activation of fibroblasts and atrophy of the smooth muscle cells

The adaptive compensations in endocrine pancreas from glucocorticoid-treated rats are reversible after the interruption of treatment

Aim:Glucocorticoid administration induces insulin resistance (IR) and enhances islet mass and insulin secretion in rodents and humans. Here, we analysed whether these effects are still present after the interruption of dexamethasone treatment.Methods:Adult Wistar rats were distributed into CTL (daily injection of saline for five consecutive days), DEX (daily injection of 1 mg kg-1 body wt of dexamethasone for five consecutive days) and DEX(10) (5 days of dexamethasone treatment, followed by a period of 10 days without dexamethasone).Results:In vivo experiments indicated that the marked hyperinsulinemia found in DEX rats during fasting and fed states was normalized in the DEX(10) group. Furthermore, the IR and glucose intolerance observed in DEX were restored in DEX(10) rats. Islets from DEX rats secreted more insulin in response to increasing concentrations of glucose and other metabolic and non-metabolic stimuli, compared with that in the CTL group. The insulin secretion for the most compounds studied returned to CTL values in DEX(10) islets. Increased insulin secretion correlated well with the augmentation in beta-cell proliferation and mass in DEX rats, and these morphological alterations were normalized in islets from DEX(10) rats. In parallel, the increased levels of proteins involved in beta-cell proliferation such as Cd2 and Cdk4 observed in DEX islets were also normalized in DEX(10) islets.Conclusion:These data strongly support the view that almost all the morphophysiological alterations induced by dexamethasone in the endocrine pancreas are reverted after discontinuation of the treatment. This information is important, considering the frequent use of glucocorticoids in humans.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq