Evaluation of the students' perceptions about the virtual self-learning process in a postgraduate professional program

Objetivos: Evaluar la percepción de los estudiantes de postgrado sobre la enseñanza virtual en tres cuestiones básicas: acceso al conocimiento, grado de satisfacción y preferencia temporal en enseñanza virtual y presencial. Metodología: El estudio se realizó a través de un cuestionario con tres grupos de ítems vinculados a los objetivos arriba indicados. Se utilizó la prueba t de Student de doble cola. Resultados y Discusión: Para los alumnos, la plataforma virtual permite acceder al profesor sin llegar a sustituirlo (p=0,0000), e igual ocurre con la ampliación de conocimientos, la cual no sustituye a los libros ni a otras fuentes (p=0,0003) (p=0,0158). La libertad de horario constituye la percepción más valorada, superando significativamente a la dificultad de uso de la plataforma (p=0,0000), la modificación del horario extralaboral (p=0,0652), el estrés académico (p=0,0020) o la conciliación de la vida familiar y laboral (p=0,0016). Los estudiantes, a pesar de la accesibilidad y la satisfacción mostrada sobre la enseñanza virtual, asignan más porcentaje a la enseñanza presencial que a la virtual, tanto en teoría como en práctica (p=0,0000) y (p=0,0000).Objectives: To evaluate the perception of postgraduate students on virtual learning in three topics: access to knowledge, satisfaction level, and time-distribution preferences in virtual and non-virtual education. Methodology: This study was carried out by using a questionnaire with three groups of items associated with the 3 objectives. The Student t test was used to analyze the results. Results and Discussion: The virtual platform allowed the students to access the instructors, but without replacing them (p=0.0000). Also the student's perception is that they can increase their knowledge without replacing books or other resources (p=0.0003) (p=0.0158). The freedom of work time was significantly more valued that the need to overcome the difficulty of using the platform (p=0.0000), changing the working hours (p=0.0652), academic stress (p=0.0020) and balancing work and family life (p=0.0016). Despite the accessibility and satisfaction with the platform, students gave more percentage of time to non-virtual learning than to virtual learning in both theory and practice (p=0.0000) and (p=0.0000)

El folículo piloso: Una importante fuente celular en ingeniería tisular

The hair follicle is a microscopic organ, functionally and structurally complex. It can be divided into two distinct segments, the upper portion, stable and the lower portion, that undergoes regeneration every hair cycle. The hair follicle contains a variety of cells types, including stem cells. It fact, it is the most important niche of stem cells in the skin, with the added advantage of its easy accessibility. These stem cells are located in a prominence at the level of the insertion of the arrector pili muscle, called bulge. They are responsible of hair follicle regeneration each hair cycle, and also can form sebaceous glands and help in repopulation of the interfollicular epidermis after injury. The knowledge of hair follicle structure is making possible the use of different types of cells, especially stem cells, in skin tissue engineering. Furthermore, recent studies have differentiated follicle stem cells into different strains, for example: nervous, hematopoietic and vascular cells. Moreover, other late studies have focused on the hair follicle construction, with satisfactory results in mice, but not completely transferable to humans, which further research is needed. The possibility of human hair follicle regeneration would suppose a revolution in the broad world of alopecia. The aim of this review is to describe the anatomical and histological structure of the hair follicle, emphasizing the importance as stem cell niche, and its potential usefulness in the field of tissue engineering for the construction of various types of tissues

Duplicación de la vesícula biliar: vesícula doble de tipo Y operada : reporte de un caso

The duplication of the gallbladder is a rare malformation, seen in one every 3.000 necropsies. It is detected preoperatively by abdominal ultrasound. We report a 28 years old female consulting for abdominal pain. An abdominal ultrasound showed the presence of cholelithiasis and a complete septum in the gallbladder lumen. During surgery, a distended and inflamed gallbladder was found with a septum that divided it in two parts, and one biliary stone. There was also a double cystic duct. The pathological study confirmed the gallbladder duplication with inflammation

Generation and characterization of an in vivo model of corneal lesion for use in tissue engineering

Objetivos: En el presente estudio se pretende generar y caracterizar un modelo lesional corneal ex vivo, con el fin de poder evaluar la viabilidad de los tejidos artificiales creados mediante Ingeniería Tisular a través de la aplicación de una causticación controlada con NaOH sobre córneas de cerdo. Métodos: Se llevó a cabo un estudio descriptivo tomando 18 ojos de cerdos adultos, inmediatamente después de morir. Los globos oculares se introdujeron en NaOH 1,5 M durante 1, 2, 3 y 5 minutos. Tras lo cual se lavaron con agua corriente (5 minutos) y se realizó un lavado rápido con PBS, seguido de un lavado de 2 minutos en PBS. Se incluyeron dos grupos control: uno de córneas no tratadas, y otro de córneas a las que se les realizó lavados de agua corriente y PBS. Las muestras fueron procesadas para el análisis histológico mediante microscopía óptica con las tinciones de hematoxilina eosina, picrosirius y azul alcian. Se determinó la significación de los resultados obtenidos mediante el análisis estadístico ANOVA. Resultados: Se observó una pérdida del endotelio y del epitelio corneal en todos los grupos tratados con NaOH. Asimismo se objetivó una tendencia a la compactación de las fibras colágenas tras el tratamiento con NaOH en la tinción de picrosirius y la pérdida de fibras de coloración verde en las muestras tratadas con NaOH con respecto a los controles. Pese a observarse una menor intensidad en la tinción de azul alcian en la región posterior con respecto a las otras dos y entre las distintas muestras tratadas con NaOH, no se encontraron diferencias significativas en este aspecto. Conclusiones: se ha logrado crear un modelo lesional sencillo, de bajo coste y que no implica problemas éticos, que permitiría evaluar los tejidos artificiales creados mediante Ingeniería Tisular.Purpose: This study aims to generate and characterize an ex vivo corneal injury model, in order to assess the feasibility of artificial tissues created by using tissue engineering through the application of a corneal alkali burn with NaOH on porcine corneas. Methods: We conducted a descriptive study taking 18 eyes of adult pigs immediately after their death. Eyes were introduced on 1.5M NaOH for 1, 2, 3 and 5 minutes. After, they were washed with running water (5 min) and rapid washing with PBS, followed by a 2 minute wash in PBS was performed. Two control groups were included: untreated corneas and another corneas were performed running water washes and PBS whashes. Samples were processed for histological analysis by light microscopy with hematoxylin and eosin, alcian blue and picrosirius staining. The significance of the results was determined by ANOVA statistical analysis. Results: We observed a loss of endothelium and the corneal epithelium in all groups treated with NaOH. A tendency to compaction of collagen fibers after treatment with NaOH and picrosirius stain loss of green coloration fibers in samples treated with NaOH with respect to controls was also observed. Despite lower intensity observed in alcian blue staining in the posterior region compared to the other two and between samples treated with NaOH, no significant differences were found in this area. Conclusions: it has created a single lesion model, low cost and does not involve ethical issues, to assess the tissue created by Tissue Engineering.Beca de Iniciación a la Investigación de la Universidad de Granad

Gelatin-crosslinked hydrogels for Tissue Engineering applications. A preliminar study

Los biomateriales juegan un papel esencial en el desarrollo de nuevos sustitutos tisulares ya que proporcionan el entorno tridimensional esencial para promover la adhesión, migración y proliferación celular. En este sentido, los biomateriales naturales aportan moléculas biológicamente activas que típicamente promueven la adhesión y el crecimiento óptimo de las células. La gelatina es un biomaterial cuyo alto contenido de colágeno y cuya red tridimensional interconectada podría contribuir a la generación de tejidos artificiales similares a los tejidos nativos. En este contexto, diferentes técnicas de entrecruzamiento químico han sido utilizadas con el fin de mejorar las propiedades físicas y mecánicas de los biomateriales de uso en Ingeniería Tisular. El glutaraldehído (GA) es un entrecruzante químico bien conocido que puede proporcionar materiales con una mejora sustancial en las propiedades de tracción. El objetivo de este artículo es determinar la concentración óptima de GA en hidrogeles de gelatina para determinar la posible aplicación de estos nuevos biomateriales entrecruzados en la clínica traslacional. A este respecto, se obtuvieron resultados interesantes que podrían ser útiles para diseñar andamios con propiedades controladas según su grado de entrecruzamiento que facilitaría la producción de productos más similares a los tejidos nativos. Los hidrogeles de gelatina entrecruzados con GA al 5% mostraron patrones morfológicos adecuados que sugieren una posible aplicación para la regeneración del tejido cardiovascular.Biomaterials play a key role in the development of new tissue substitutes as they provide the essential 3D environment to promote cell adhesion, migration and proliferation. In this sense natural biomaterials offer biologically active molecules which typically promote excellent cells adhesion and growth. Gelatin is a biomaterial whose high collagen content and its interbranching 3D network could certainly contribute to the construction of more native-like tissues. In this context, different techniques of chemical cross-linking have been used in order to improve the physical and mechanical properties of biomaterials for use in Tissue Engineering. Glutaraldehyde (GA) is a well-known chemical crosslinker that can provide materials with substantial improvement in tensile properties. The aim of this article is to test different GA concentrations to crosslink gelatin hydrogels to evaluate the potential application of these new crosslinked biomaterials according to the specific properties of the different tissues in the translational clinic. In this regard interesting findings were obtained that could be helpful to design controlled-properties scaffolds regarding its crosslinked degree that would facilitate the production of more suitable tissue-like products. The proposed 5% GA crosslinked gelatin hydrogels shown morphological patterns and meet the requirements of a first macroscopic and microscopic evaluation which suggests a potential application for the regeneration of cardiovascular tissue