Alejandra Espinosa - Academia.edu (original) (raw)

Papers by Alejandra Espinosa

Occupational Therapy International, 2022

Life Sciences

Lipid droplets (LD) are not just lipid stores. They are now recognized as highly dynamic organell... more Lipid droplets (LD) are not just lipid stores. They are now recognized as highly dynamic organelles, having a life cycle that includes biogenesis, growth, steady-state, transport, and catabolism. Importantly, LD exhibit different features in terms of size, number, lipid composition, proteins, and interaction with other organelles, and all these features exert an impact on cellular homeostasis. The imbalance of LD function causes non-alcoholic fatty liver disease (NAFLD). Studies show that exercise attenuates NAFLD by decreasing LD content; however, reports show metabolic benefits without changes in LD amount (intrahepatic triglyceride levels) in NAFLD. Due to the multiple effects of exercise in LD features, we think that these metabolic benefits occur through changes in LD features in NAFLD, rather than only the reduction in content. Exercise increases energy mobilization and utilization from storages such as LD, and is one of the non-pharmacological treatments against NAFLD. Therefore, exercise modification of LD could be a target for NAFLD treatment. Here, we review the most up-to-date literature on this topic, and focus on recent findings showing that LD features could play an important role in the severity of NAFLD.

International Journal of Molecular Sciences, 2020

Glucocorticoids (GCs) are critical regulators of energy balance. Their deregulation is associated... more Glucocorticoids (GCs) are critical regulators of energy balance. Their deregulation is associated with the development of obesity and metabolic syndrome. However, it is not understood if obesity alters the tissue glucocorticoid receptor (GR) response, and moreover whether a moderate aerobic exercise prevents the alteration in GR response induced by obesity. Methods: To evaluate the GR response in obese mice, we fed C57BL6J mice with a high-fat diet (HFD) for 12 weeks. Before mice were sacrificed, we injected them with dexamethasone. To assess the exercise role in GR response, we fed mice an HFD and subjected them to moderate aerobic exercise three times a week. Results: We found that mice fed a high-fat diet for 12 weeks developed hepatic GC hypersensitivity without changes in the gastrocnemius or epididymal fat GR response. Therefore, moderate aerobic exercise improved glucose tolerance, increased the corticosterone plasma levels, and prevented hepatic GR hypersensitivity with an i...

ARS MEDICA Revista de Ciencias Médicas, 2021

Introducción: el presente artículo describe la implementación de la educación interprofesional en... more Introducción: el presente artículo describe la implementación de la educación interprofesional en estudiantes de primer año de tres carreras del departamento de ciencias de la salud de la Universidad Católica (UC) a través de la metodología de aprendizaje servicio, durante la pandemia COVID-19, con el fin de promover habilidades transversales y fortalecer aprendizajes vinculados a diferentes realidades sociales en futuros profesionales. Método: la metodología de esta investigación es de carácter mixta concurrente con predominancia cuantitativa, de secuencia transversal y alcance descriptivo. Consiste en una encuesta, voluntaria y anónima, compuesta por preguntas abiertas y de escala Likert, aplicada a 239 estudiantes de las carreras de terapia ocupacional, kinesiología y nutrición durante el primer semestre de 2021. Resultados: la percepción de estudiantes sobre la metodología de aprendizaje-servicio interdisciplinario, a pesar de la modalidad virtual dada por la pandemia, es positi...

Persona, 2008

Características psicosociales en niños en contextos de riesgo y de no riesgo

Revista de la Facultad de Medicina, 2020

Introducción. Las múltiples exigencias académicas a las que los estudiantes universitarios se enf... more Introducción. Las múltiples exigencias académicas a las que los estudiantes universitarios se enfrentan les generan altos niveles de estrés; si bien el estrés puede ayudarles a afrontar tales exigencias, en muchos casos este puede causarles diversos problemas de salud.Objetivo. Evaluar si la implementación de la meditación activa en la rutina diaria de estudiantes universitarios de las ciencias de la salud tiene un efecto en sus indicadores físicos y psicoemocionales.Materiales y métodos. Estudio piloto exploratorio y cuantitativo realizado en una muestra de 22 estudiantes universitarios que aceptaron participar en un curso electivo de meditación activa de 3 meses (18 sesiones). A los participantes se les solicitó diligenciar el Cuestionario de Percepción Global de Estado (CPGE) ex ante y ex post al curso.Resultados. 18 participantes completaron el CPGE ex ante y ex post, pero solo 16 fueron válidos para el procesamiento de datos. La mayoría de estudiantes reportó una mejora respect...

Resumen: El estrés en académicos/as es un problema a nivel global altamente complejo. En este con... more Resumen: El estrés en académicos/as es un problema a nivel global altamente complejo. En este contexto, el presente estudio compara la carga laboral académica de hombres y mujeres determinando si existe asociación significativa con la aparición del Síndrome de Burnout entre las variables de estrés, antigüedad laboral, sexo y sobrecarga laboral. Además, busca determinar la relación entre la carga mental y la aparición del Síndrome de Burnout asociada a la rutina ocupacional de los/as profesores/as asistentes; proporciona evidencias significativas sobre la correlación carga laboral y Síndrome de Burnout en académicos universitarios, identificando factores de riesgo para hombres y mujeres; y describe los factores de riesgo en salud laboral e identifica los factores asociados al surgimiento del Burnout, distinguiendo los factores organizacionales, individuales y sociales. Lo anterior contribuye al conocimiento acumulado sobre Síndrome de Burnout en contextos educativos universitarios.

The FASEB Journal, 2021

In obesity, skeletal muscle mitochondrial activity changes to cope with increased nutrient availa... more In obesity, skeletal muscle mitochondrial activity changes to cope with increased nutrient availability. Autophagy has been proposed as an essential mechanism involved in the regulation of mitochondrial metabolism. Still, the contribution of autophagy to mitochondrial adaptations in skeletal muscle during obesity is unknown. Here, we show that in response to high‐fat diet (HFD) feeding, distinct skeletal muscles in mice exhibit differentially regulated autophagy that may modulate mitochondrial activity. We observed that after 4 and 40 weeks of high‐fat diet feeding, OXPHOS subunits and mitochondrial DNA content increased in the oxidative soleus muscle. However, in gastrocnemius muscle, which has a mixed fiber‐type composition, the mitochondrial mass increased only after 40 weeks of HFD feeding. Interestingly, fatty acid‐supported mitochondrial respiration was enhanced in gastrocnemius, but not in soleus muscle after a 4‐week HFD feeding. This increased metabolic profile in gastrocnemius was paralleled by preserving autophagy flux, while autophagy flux in soleus was reduced. To determine the role of autophagy in this differential response, we used an autophagy‐deficient mouse model with partial deletion of Atg7 specifically in skeletal muscle (SkM‐Atg7+/− mice). We observed that Atg7 reduction resulted in diminished autophagic flux in skeletal muscle, alongside blunting the HFD‐induced increase in fatty acid‐supported mitochondrial respiration observed in gastrocnemius. Remarkably, SkM‐Atg7+/− mice did not present increased mitochondria accumulation. Altogether, our results show that HFD triggers specific mitochondrial adaptations in skeletal muscles with different fiber type compositions, and that Atg7‐mediated autophagy modulates mitochondrial respiratory capacity but not its content in response to an obesogenic diet.

Applied Physiology, Nutrition, and Metabolism, 2020

Chronic high-fat diet feeding is associated with obesity and accumulation of fat in the liver, le... more Chronic high-fat diet feeding is associated with obesity and accumulation of fat in the liver, leading to the development of insulin resistance and nonalcoholic fatty liver disease. This condition is characterized by the presence of a high number of intrahepatic lipid droplets (LDs), with changes in the perilipin pattern covering them. This work aimed to describe the distribution of perilipin (Plin) 2, an LD-associated protein involved in neutral lipid storage, and Plin5, which favors lipid oxidation in LD, and to evaluate lipid peroxidation through live-cell visualization using the lipophilic fluorescent probe C11-BODIPY581/591 in fresh hepatocytes isolated from mice fed a high-fat diet (HFD). Male C57BL/6J adult mice were divided into control and HFD groups and fed with a control diet (10% fat, 20% protein, and 70% carbohydrates) or an HFD (60% fat, 20% protein, and 20% carbohydrates) for 8 weeks. The animals fed the HFD showed a significant increase of Plin2 in LD of hepatocytes....

Digestive and Liver Disease, 2020

Objective: Obesity-induced by high-fat diet (HFD) is associated with liver steatosis, oxidative s... more Objective: Obesity-induced by high-fat diet (HFD) is associated with liver steatosis, oxidative stress and mitochondrial dysfunction, which can be eluded by the co-administration of the lipid metabolism modulator docosahexaenoic acid (DHA) and the antioxidant hydroxytyrosol (HT). Methods: C57BL/6J mice fed a HFD were orally administered either with vehicle, DHA, HT or DHA + HT for 12 weeks. We measured parameters related to insulin resistance, serum lipid levels, liver fatty acid (FA) content and steatosis score, concomitantly with those associated with mitochondrial energy functions modulated by the transcriptional coactivator PGC-1a. Results: HFD induced insulin resistance, liver steatosis with n −3 FA depletion, and loss of mitochondrial respiratory functions with diminished NAD + /NADH ratio and ATP levels compared with CD, with the parallel decrease in the expression of the components of the PGC-1 α cascade, namely, PPAR-α, FGF21 and AMPK, effects that were not observed in mice subjected to DHA and HT co-administration. Conclusions: Data presented indicate that the combination of DHA and HT prevents the development of liver steatosis and the associated mitochondrial dysfunction induced by HFD, thus strengthening the significance of this protocol as a therapeutic strategy avoiding disease evolution into more irreversible forms characterised by the absence of adequate pharmacological therapy in human obesity.

Psicología Iberoamericana, 2006

El hecho de que en algunas regiones de México la situación socioeconómica es precaria, con expect... more El hecho de que en algunas regiones de México la situación socioeconómica es precaria, con expectativas ocupacionales o laborales limitadas pocas oportunidades de tener un nivel socioeconómico confortable, además de la proximidad que tiene México con Estados Unidos, influencia la decisión de migrar hacia este último país. La manera en que las personas probablemente acepten o rechacen algunos aspectos de la nueva cultura puede influenciar esta decisión. Con base en lo anterior, el objetivo principal del presente trabajo es explorar qué tipo de motivaciones y actitudes hacia la aculturación están presentes en migrantes potenciales mexicanos. Utilizando una muestra no probabilística de 580 adolescentes de dos estados de la República Mexicana (de áreas con altos niveles de migración) se evaluaron las cuatro actitudes de aculturación propuestas por Berry (1992) en un formato de viñetas. Los resultados indican que la actitud más frecuente es la integración; sin embargo, el hecho de que el...

Psicología Iberoamericana, 2007

El propósito de esta investigación fue conocer el signifi cado psicológico de los términos Buen M... more El propósito de esta investigación fue conocer el signifi cado psicológico de los términos Buen Maestro y Mal Maestro en un estudio exploratorio, utilizando la técnica de redes semánticas naturales. La muestra fue de 200 profesores y 200 alumnos de licenciatura de la Universidad Iberoamericana, de ambos sexos, y de cuatro diferentes áreas académicas (Físico-Matemáticas, Químico-Biológicas, Económico-Administrativas y Sociales Artísticas), seleccionada de manera no probabilística. Los resultados ayudan a establecer las características generales que contribuyen a defi nir ambos perfi les y muestran las diferencias que existen en la conceptuación en los dos estímulos para todos los grupos estudiados.

Medwave, 2020

Introduction SARS CoV-2 pandemic is pressing hard on the responsiveness of health systems worldwi... more Introduction SARS CoV-2 pandemic is pressing hard on the responsiveness of health systems worldwide, notably concerning the massive surge in demand for intensive care hospital beds. Aim This study proposes a methodology to estimate the saturation moment of hospital intensive care beds (critical care beds) and determine the number of units required to compensate for this saturation. Methods A total of 22,016 patients with diagnostic confirmation for COVID-19 caused by SARS-CoV-2 were analyzed between March 4 and May 5, 2020, nationwide. Based on information from the Chilean Ministry of Health and ministerial announcements in the media, the overall availability of critical care beds was estimated at 1,900 to 2,000. The Gompertz function was used to estimate the expected number of COVID-19 patients and to assess their exposure to the available supply of intensive care beds in various possible scenarios, taking into account the supply of total critical care beds, the average occupationa...

Prostaglandins, Leukotrienes and Essential Fatty Acids, 2020

The administration of iron induces liver oxidative stress and depletion of long-chain polyunsatur... more The administration of iron induces liver oxidative stress and depletion of long-chain polyunsaturated fatty acids (LCPUFAs), n-6/n-3 LCPUFA ratio enhancement and fat accumulation, which may be prevented by antioxidantrich extra virgin olive oil (AR-EVOO) supplementation. Male Wistar rats were subjected to a control diet (50 mg iron/kg diet) or iron-rich diet (IRD; 200 mg/kg diet) with alternate AR-EVOO for 21 days. Liver fatty acid (FA) analysis was performed by gas-liquid chromatography (GLC) after lipid extraction and fractionation, besides Δ-5 desaturase (Δ-5 D) and Δ6-D mRNA expression (qPCR) and activity (GLC) measurements. The IRD significantly (p < 0.05) increased hepatic total fat, triacylglycerols, free FA contents and serum transaminases levels, with diminution in those of n-6 and n-3 LCPUFAs, higher n-6/n-3 ratios, lower unsaturation index and Δ5-D and Δ6-D activities, whereas the mRNA expression of both desaturases was enhanced over control values, changes that were prevented by concomitant AR-EVOO supplementation. N-6 and n-3 LCPUFAs were also decreased by IRD in extrahepatic tissues and normalized by AR-EVOO. In conclusion, AR-EVOO supplementation prevents IRD-induced changes in parameters related to liver FA metabolism and steatosis, an effect that may have a significant impact in the treatment of iron-related pathologies or metabolic disorders such as non-alcoholic fatty liver disease.