Cryopreservation: An Overview of Principles and Cell-Specific Considerations.

The origins of low-temperature tissue storage research date back to the late 1800s. Over half a century later, osmotic stress was revealed to be a main contributor to cell death during cryopreservation. Consequently, the addition of cryoprotective agents (CPAs) such as dimethyl sulfoxide (DMSO), glycerol (GLY), ethylene glycol (EG), or propylene glycol (PG), although toxic to cells at high concentrations, was identified as a necessary step to protect against rampant cell death during cryopreservation. In addition to osmotic stress, cooling and thawing rates were also shown to have significant influence on cell survival during low temperature storage. In general, successful low-temperature cell preservation consists of the addition of a CPA (commonly 10% DMSO), alone or in combination with additional permeating or non-permeating agents, cooling rates of approximately 1ºC/min, and storage in either liquid or vapor phase nitrogen. In addition to general considerations, cell-specific recommendations for hepatocytes, pancreatic islets, sperm, oocytes, and stem cells should be observed to maximize yields. For example, rapid cooling is associated with better cryopreservation outcomes for oocytes, pancreatic islets, and embryonic stem cells while slow cooling is recommended for cryopreservation of hepatocytes, hematopoietic stem cells, and mesenchymal stem cells. Yields can be further maximized by implementing additional pre-cryo steps such as: pre-incubation with glucose and anti-oxidants, alginate encapsulation, and selecting cells within an optimal age range and functional ability. Finally, viability and functional assays are critical steps in determining the quality of the cells post-thaw and improving the efficiency of the current cryopreservation methods.

Mejora de habilidades en la interpretación del electrocardiograma mediante un taller con simulación clínica / Improvement of electrocardiogram interpretation skills through a workshop with clinical simulation

RESUMEN Fundamento: en la electrocardiografía es importante tener la habilidad de interpretar, además de confianza para lograr una definición certera en el diagnóstico y tratamiento. Objetivo: implementar un taller utilizando el aprendizaje basado en la simulación clínica para la interpretación del electrocardiograma. Métodos: se realizó un estudio de tipo descriptivo y longitudinal en la Facultad de Medicina de la Universidad Nacional Autónoma de México, durante 2018. Se utilizaron métodos teóricos: análisis-síntesis e inducción-deducción; y empíricos: una encuesta y un examen de interpretación de electrocardiograma antes y después del taller aplicado. Resultados: en la evaluación sobre la identificación del electrocardiograma hubo una mejoría significativa posterior a la realización del taller en aspectos como: la interpretación del ritmo, del eje cardíaco, de ondas y en la asignación de diagnósticos en un menor tiempo según el postest. Se constató la diferencia de resultados tanto en confianza, aptitudes obtenidas, resolución de dudas y de aprendizaje reflexivo centrados en la génesis de cada aspecto del electrocardiograma, lo que permitió al equipo de trabajo ubicarlos como puntos clave en la adquisición de habilidades prácticas e intelectuales. Conclusiones: la implementación del taller permitió una mejoría significativa en las habilidades de los estudiantes para la interpretación del electrocardiograma, lo cual condicionó que se sintieran más confiados en sus apreciaciones; por lo que se evidenció la efectividad de su aplicación.

ABSTRACT Background: in electrocardiography it is important to have the ability to interpret, as well as confidence to achieve an accurate definition in diagnosis and treatment. Objective: to implement a workshop using clinical simulation based learning for electrocardiogram interpretation. Methods: a descriptive and longitudinal study was carried out at the Faculty of Medicine of Mexico National Autonomous University, during 2018. Theoretical methods were used: analysis-synthesis and induction-deduction; and empirical: a survey and an electrocardiogram interpretation test before and after the applied workshop. Results: in the evaluation on the identification of the electrocardiogram there was a meaningful improvement after the workshop was carried out in aspects such as: the interpretation of the rhythm, of the cardiac axis, of waves and in the assignment of diagnoses in a shorter time according to the posttest. The difference in results was observed both in confidence, skills obtained, resolution of doubts and reflexive learning focused on the genesis of each aspect of the electrocardiogram, which allowed the working team to locate them as key points in the acquisition of practical and intellectual skills. Conclusions: the implementation of the workshop allowed a meaningful improvement in the students' abilities to interpret the electrocardiogram, which caused them to feel more confident in their assessments; so the effectiveness of its application was evidenced.

Heart failure with preserved ejection fraction: the dark side of an old disease.

Heart failure is a global public health problem, with more than 37 million patients living with heart failure around the world. Heart failure with preserved ejection fraction is an increasingly common category (approximately 60% of the cases) and shows remarkable differences in diagnosis and treatment when compared with heart failure with reduced ejection fraction. The current review covers epidemiology, risk factors, pathophysiologic mechanisms, clinical and paraclinical characteristics and diagnostic criteria of heart failure with preserved ejection fraction and concludes with a plea for original research in our country.

La insuficiencia cardíaca (IC) es un problema de salud pública global con más de 37 millones de individuos afectados en el mundo. La insuficiencia cardíaca con fracción de expulsión preservada (ICFEp) representa una categoría cada vez más frecuente en la práctica clínica, constituye hasta el 60% de los casos y presenta diferencias importantes en el diagnóstico y tratamiento en comparación con la insuficiencia cardíaca y la fracción de expulsión reducida. Esta revisión de ICFEp expone la epidemiología, delimita los principales factores de riesgo y mecanismos fisiopatológicos, identifica las características clínicas/paraclínicas y los criterios diagnósticos, y finaliza con un llamado para realizar investigación en este país.

Insuficiencia cardíaca con fracción de expulsión preservada: el lado oscuro de una vieja enfermedad / Heart failure with preserved ejection fraction: the dark side of an old disease

Resumen La insuficiencia cardíaca (IC) es un problema de salud pública global con más de 37 millones de individuos afectados en el mundo. La insuficiencia cardíaca con fracción de expulsión preservada (ICFEp) representa una categoría cada vez más frecuente en la práctica clínica, constituye hasta el 60% de los casos y presenta diferencias importantes en el diagnóstico y tratamiento en comparación con la insuficiencia cardíaca y la fracción de expulsión reducida. Esta revisión de ICFEp expone la epidemiología, delimita los principales factores de riesgo y mecanismos fisiopatológicos, identifica las características clínicas/paraclínicas y los criterios diagnósticos, y finaliza con un llamado para realizar investigación en este país.

Abstract Heart failure is a global public health problem, with more than 37 million patients living with heart failure around the world. Heart failure with preserved ejection fraction is an increasingly common category (approximately 60% of the cases) and shows remarkable differences in diagnosis and treatment when compared with heart failure with reduced ejection fraction. The current review covers epidemiology, risk factors, pathophysiologic mechanisms, clinical and paraclinical characteristics and diagnostic criteria of heart failure with preserved ejection fraction and concludes with a plea for original research in our country.

Cannabinoid and nicotine exposure during adolescence induces sex-specific effects on anxiety- and reward-related behaviors during adulthood.

Nicotine and cannabis use during adolescence has the potential to induce long lasting changes on affective and cognitive function. Here, we examined whether adolescent exposure to nicotine, the cannabinoid agonist WIN55-212,2 (WIN), or co-exposure to both would alter operant learning, locomotion, and anxiety- and reward-related behaviors in male and female mice during adulthood. Males exposed to a moderate dose of WIN (2 mg/kg) or co-exposed to nicotine and the moderate dose of WIN exhibited decreased anxiety-associated behaviors and increased cognitive flexibility, but did not differ in operant learning or generalized locomotion. In contrast, differences were not found among the females in these measures at the moderate WIN dose or in both sexes with exposure to a low WIN dose (0.2 mg/kg). Furthermore, a sex-dependent dissociative effect was found in natural reward consumption. Males exposed to the moderate dose of WIN or co-exposed to nicotine and the moderate dose of WIN demonstrated increased sucrose consumption. In contrast, females exposed to the moderate dose of WIN exhibited a decrease in sucrose consumption, which was ameliorated with co-administration of nicotine. Together, these novel findings demonstrate that adolescent exposure to cannabinoids in the presence or absence of nicotine results in altered affective and reward-related behaviors during adulthood.

Aspectos importantes a tomar en cuenta en la regulación del servicio triple - play en Bolivia

Plantea que las cooperativas de telecomunicaciones en Bolivia, están haciendo grandes inversiones para poder adecuarse a un nuevo mercado de servicios convergentes, y nuevamente se están enfrentando con el problema de que el avance de la tecnología se ha adelantado a la regulación del sector