The Antidiabetic Effect of MSCs Is Not Impaired by Insulin Prophylaxis and Is Not Improved by a Second Dose of Cells

Type 1 diabetes mellitus (T1D) is due to autoimmune destruction of pancreatic beta-cells. Previously, we have shown that intravenously administered bone marrow-derived multipotent mesenchymal stromal cells (MSCs) allows pancreatic islet recovery, improves insulin secretion and reverts hyperglycemia in low doses streptozotocin (STZ)-induced diabetic mice. Here we evaluate whether insulin prophylaxis and the administration of a second dose of cells affect the antidiabetic therapeutic effect of MSC transplantation. Insulitis and subsequent elimination of pancreatic beta-cells was promoted in C57BL/6 mice by the injection of 40 mg/kg/day STZ for five days. Twenty-four days later, diabetic mice were distributed into experimental groups according to if they received or not insulin and/or one or two doses of healthy donor-derived MSCs. Three and half months later: glycemia, pancreatic islets number, insulinemia, glycated hemoglobin level and glucose tolerance were determined in animals that did not received exogenous insulin for the last 1.5 months. Also, we characterized MSCs isolated from mice healthy or diabetic. The therapeutic effect of MSC transplantation was observed in diabetic mice that received or not insulin prophylaxis. Improvements were similar irrespective if they received one or two doses of cells. Compared to MSCs from healthy mice, MSCs from diabetic mice had the same proliferation and adipogenic potentials, but were less abundant, with altered immunophenotype and no osteogenic potential

Teorías implícitas sobre la enseñanza y su asociación con las prácticas pedagógicas de los docentes de la carrera de Medicina.

Introduction: To impulse educational innovation the comprehension of teacher's beliefs is critical. Implicit theories about teaching are personal unconscious mental constructions regarding education. They are the result of individual's reality perspective and previous experiences. They are activated under the demand of the context. Pedagogical practice is conditioned by teacher�s implicit theories about teaching. Objectives: The aim of this study was to characterize the implicit theories about teaching and the pedagogical models used by medical teachers. Also, to explore whether the former correlate with i) personal characteristics (gender, formal teaching training, years of teaching experience), ii) the way that they teach (pedagogical model used), iii) the students perception of their pedagogical practice, particularly their expectations regarding student's participation in the construction of knowledge. Material and Method: Teachers (60) and students (580) of the Medical School of Facultad de Medicina Clínica Alemana- Universidad del Desarrollo answered previously validated closed questionnaires. Also, observation was made guided by a matching pattern. Results: It was found that medical teachers adhere mainly to expressive (48%) and interpretative (28%) implicit theories. Also, they use predominantly active (42%) and constructivist (30%) pedagogical models. On another hand, students perceive that most of their teachers expect their engagement in the construction of knowledge (93%). A statistically significant positive correlation was proved between implicit theory about teaching and the pedagogical model used by medical teachers. Conclusions: The high rate of medical teachers that adhere to implicit theories about teaching and that use pedagogical models centered in the student is encouraging, since they are critical for the implementation of curriculum innovations designed to improve the autonomy, self-motivation and self-efficacy of undergraduate students.Introducción: Para favorecer los procesos de innovación pedagógica es central conocer las creencias de los docentes. Las teorías implícitas sobre la enseñanza corresponden a constructos mentales inconscientes que poseen las personas sobre la docencia. Estas resultan del modo de ver la realidad y de la acumulación de experiencias adquiridas previamente. Ellas se activan ante las demandas del contexto. La práctica pedagógica está condicionada por las teorías implícitas sobre la enseñanza de los docentes. Objetivos: El objetivo del presente trabajo fue caracterizar las teorías implícitas sobre la enseñanza a las que adhieren y los modelos pedagógicos que usan los docentes de la carrera de Medicina. También, explorar si las primeras se relacionan con i) características personales (género, formación docente formal, años de experiencia docente), ii) la forma en que ellos enseñan (modelo pedagógico usado), iii) la percepción que sus estudiantes tienen de su práctica docente, en particular de la participación que esperan de ellos en la construcción del conocimiento. Material y Método: Docentes (60) y estudiantes (580) de la carrera de Medicina de la Facultad de Medicina Clínica Alemana - Universidad del Desarrollo respondieron cuestionarios cerrados previamente validados. También se realizó observación guiada por una pauta de cotejo. Resultados: Se encontró que los docentes de la carrera de Medicina adhieren mayoritariamente a las teorías implícitas expresiva (48%) e interpretativa (28%). También, que utilizan predominantemente los modelos pedagógicos activo (42%) y constructivista (30%). Por su parte, los estudiantes perciben que la mayoría de sus docentes esperan que ellos participen activamente en la construcción del conocimiento (93%). Solo se demostró una correlación positiva estadísticamente significativa entre la teoría implícita sobre la enseñanza a la que adhieren y el modelo pedagógico usado por los docentes de la carrera de Medicina. Conclusiones: La alta tasa de docentes de la carrera de Medicina que adhiere a las teorías implícitas sobre la enseñanza y que usa modelos pedagógicos centrados en el estudiante es promisoria, puesto que ellos son actores clave en la implementación de reformas curriculares destinadas a potenciar autonomía, automotivación y autoeficacia en los estudiantes universitarios

Novel and recurrent COL7A1 mutations in Chilean patients with dystrophic epidermolysis bullosa

Artículo de publicación IS

Mice long-term high-fat diet feeding recapitulates human cardiovascular alterations: an animal model to study the early phases of diabetic cardiomyopathy

Background/Aim: Hypercaloric diet ingestion and sedentary lifestyle result in obesity. Metabolic syndrome is a cluster of clinical features secondary to obesity, considered as a pre-diabetic condition and recognized as an independent risk factor for cardiovascular diseases. To better understand the relationship between obesity, metabolic syndrome and cardiovascular disease as well as for the development of novel therapeutic strategies, animal models that reproduce the etiology, course and outcomes of these pathologies are required. The aim of this work was to characterize the long-term effects of high-fat diet-induced obesity on the mice cardiovascular system, in order to make available a new animal model for diabetic cardiomyopathy. Methods/Results: Male C57BL/6 mice were fed with a standardized high-fat diet (obese) or regular diet (normal) for 16 months. Metabolic syndrome was evaluated testing plasma glucose, triglycerides, cholesterol, insulin, and glucose tolerance. Arterial pressure was measured using a sphygmomanometer (non invasive method) and by hemodynamic parameters (invasive method). Cardiac anatomy was described based on echocardiography and histological studies. Cardiac function was assessed by cardiac catheterization under a stress test. Cardiac remodelling and metabolic biomarkers were assessed by RT-qPCR and immunoblotting. As of month eight, the obese mice were overweight, hyperglycaemic, insulin resistant, hyperinsulinemic and hypercholesterolemic. At month 16, they also presented normal arterial pressure but altered vascular reactivity (vasoconstriction), and cardiac contractility reserve reduction, heart mass increase, cardiomyocyte hypertrophy, cardiac fibrosis, and heart metabolic compensations. By contrast, the normal mice remained healthy throughout the study. Conclusions: Mice fed with a high-fat diet for prolonged time recapitulates the etiology, course and outcomes of the early phases of human diabetic cardiomyopathy