Neurodegenerative diseases are characterized by the progressive loss of neurons in different regions of the nervous system. Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most prevalent neurodegenerative diseases, and the symptoms associated with these pathologies are closely related to the regions that are most affected by the process of neurodegeneration. Despite their high prevalence, currently, there is no cure or disease-modifying drugs for the treatment of these conditions. In the last decades, due to the need for the development of new treatments for neurodegenerative diseases, several authors have investigated the neuroprotective actions of naturally occurring molecules, such as resveratrol. Resveratrol is a stilbene found in several plants, including grapes, blueberries, raspberries, and peanuts. Studies have shown that resveratrol presents neuroprotective actions in experimental models of AD and PD, however, its clinical application is limited due to its rapid metabolism and low bioavailability. In this context, studies have proposed that structural changes in the resveratrol molecule, including glycosylation, alkylation, halogenation, hydroxylation, methylation, and prenylation could lead to the development of derivatives with enhanced bioavailability and pharmacological activity. Therefore, this review article aims to discuss how resveratrol derivatives could represent viable molecules in the search for new drugs for the treatment of AD and PD.

The teaching-learning process must constantly overcome the barriers imposed by rapid scientific and technological advances, as well as changes in the profile of students and access to information. This study intended to analyze the perceptions of students and professors of medical courses about the teaching-learning strategies used in physiology at different Brazilian universities, as well as the factors that influence or hinder the learning of this discipline. There were analyzed questionnaires from 174 students and 16 professors of physiology from medical courses of 20 higher education institutions (public and private) in a southern Brazilian state. The teaching strategies most used by physiology teachers coincided with the classroom activities that students consider to have the greatest contribution to their learning (expository classes/lectures, tests and questionnaires, problem-based learning/clinical case studies and demonstrative/practical classes). It was also evidenced that teachers' didactic is considered as a very influencing factor for the students during their learning process, while the teachers pointed out daily pedagogical practice as the most relevant factor in the development of their skills within the classroom. Besides, some factors hindering the teaching-learning process of physiology were identified by the respondents, such as: large amount of information, little time for study outside the classroom, previous knowledge and intrinsic difficult of the discipline. Finally, students tend to study alone and generally used teachers' slides and their own notes as study materials. The continuous assessment of the perceptions, needs and difficulties of students and teachers plays an essential role improving the teaching-learning process.

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Introduction We hypothesize that high altitudes could have an adverse effect on neonatal health outcomes, especially among at-risk neonates. The current study aims to assess the association between higher altitudes on survival time among at-risk neonates. Methods Retrospective survival analysis. Setting: Ecuadorian neonates who died at ≤28 days of life. Patients: We analyzed the nationwide dataset of neonatal deaths from the Surveillance System of Neonatal Mortality of the Ministry of Public Health of Ecuador, registered from 126 public and private health care facilities, between January 2014 to September 2017. Main outcome measures: We retrospectively reviewed 3016 patients. We performed a survival analysis by setting the survival time in days as the primary outcome and fixed and mixed-effects Cox proportional hazards models to estimate hazard ratios (HR) for each altitude stratum of each one of the health care facilities in which those neonates were attended, adjusting by individual variables (i.e., birth weight, gestational age at birth, Apgar scale at 5 minutes, and comorbidities); and contextual variables (i.e., administrative planning areas, type of health care facility, and level of care). Results Altitudes of health care facilities ranging from 80 to <2500 m, 2500 to <2750m, and ≥2750 m were associated respectively with 20% (95% CI: 1% to 44%), 32% (95% CI:<1% to 79%) and 37% (95% CI: 8% to 75%) increased HR; compared with altitudes at <80 m. Conclusion Higher altitudes are independently associated with shorter survival time, as measured by days among at-risk neonates. Altitude should be considered when assessing the risk of having negative health outcomes during neonatal period.

La enfermedad veno-oclusiva hepática o síndrome de obstrucción sinusoidal se caracteriza clínicamente por presentar hepatomegalia dolorosa, ictericia, ascitis, edema, aumento de peso y/o trombocitopenia refractaria, que generalmente ocurre como una complicación del trasplante de médula ósea y la quimioterapia en algunos tumores sólidos. La fisiopatología es compleja y se relaciona con daño endotelial en los sinusoides hepáticos que condiciona un estado proinflamatorio, protrombótico e hipofibrinolítico. El tratamiento varía de acuerdo a la severidad de cada caso, cuando son cuadros leves a moderados se presenta una resolución espontánea requiriendo medidas de soporte y tratamiento sintomático; mientras que en los casos severos o muy severos se requiere adicionar tratamiento específico debido a la alta mortalidad que presentan estos pacientes. Considerando la alta mortalidad y las escasas opciones terapéuticas aprobadas actualmente, la identificación de factores de riesgo sigue siendo la principal estrategia para disminuir la incidencia de esta enfermedad, de ahí la importancia de esta revisión.

Los autores declaran no tener conflictos de interés. Fuente de financiamiento: ninguna.

Introducción: A pesar del difícil acceso anatómico para los tumores de mediastino, la resección quirúrgica sigue siendo el mejor enfoque diagnóstico y terapéutico. El objetivo de la presente serie de casos presentamos la experiencia de un centro oncológico en el abordaje de tumores del mediastino y sus resultados. Métodos: En el departamento de Jefatura de Cirugía Oncológica del Instituto Oncológico nacional de Solca-Guayaquil, durante los meses de Enero del 2013 a Enero 2017 se realizó un estudio descriptivo, retrospectivo. Se analizaron todos los casos de pacientes derivados del área de pre admisión con diagnóstico inicial de tumor de mediastino, a los cuales previo a realizarles marcadores tumorales, Tomografía de Tórax, y a quienes se les realizó como método diagnóstico y en algunos casos terapéutico con abordaje quirúrgico. Se excluyeron pacientes con neoplasias de origen secundario, con historias clínicas incompletas que imposibilitaron el análisis. Se estudiaron las variables sexo, edad, Tipo de Técnica quirúrgica, localización del tumor, diagnostico histopatológico y mortalidad perioperatoria. El análisis estadístico realizado fue descriptivo. Resultados: Se evaluaron 22 pacientes con diagnóstico tumor de mediastino, con una edad media de 60 años. Fueron 13 hombres (59 %). Catorce pacientes con lesión maligna, 8 fueron operados con resección tumoral y 6 se sometieron a biopsia. Se reportaron fallecimientos post-operatorios hasta los 30 días postquirúrgicos en 5 casos (22.7%). Las intervenciones quirúrgicas realizadas con más frecuencia fueron toracotomías derechas con toma de biopsia o resección tumoral 7 casos (31.8 %). En relación al resultado anatomopatológico de los tumores de mediastino reportados más de la mitad constituyeron Adenocarcinomas 14 casos (63.6 %). Conclusión: Los pacientes portadores de neoplasia benigna en esta serie tuvieron una evolución posquirúrgica satisfactoria. El adenocarcinoma fue el tumor maligno más frecuente en esta serie.