Myogenic microRNAs as Therapeutic Targets for Skeletal Muscle Mass Wasting in Breast Cancer Models.

Breast cancer is the type of cancer with the highest prevalence in women worldwide. Skeletal muscle atrophy is an important prognostic factor in women diagnosed with breast cancer. This atrophy stems from disrupted skeletal muscle homeostasis, triggered by diminished anabolic signalling and heightened inflammatory conditions, culminating in an upregulation of skeletal muscle proteolysis gene expression. The importance of delving into research on modulators of skeletal muscle atrophy, such as microRNAs (miRNAs), which play a crucial role in regulating cellular signalling pathways involved in skeletal muscle protein synthesis and degradation, has been recognised. This holds true for conditions of homeostasis as well as pathologies like cancer. However, the determination of specific miRNAs that modulate skeletal muscle atrophy in breast cancer conditions has not yet been explored. In this narrative review, we aim to identify miRNAs that could directly or indirectly influence skeletal muscle atrophy in breast cancer models to gain an updated perspective on potential therapeutic targets that could be modulated through resistance exercise training, aiming to mitigate the loss of skeletal muscle mass in breast cancer patients.

Correlación entre la Velocidad de Marcha y Largo del Paso en Personas Mayores de la Cuarta Edad que Viven en la Comunidad / Correlation between Walking Speed and Step Length in Seniors Living in the Community

Introducción. La población de personas mayores de la cuarta edad (≥80 años) crece a gran velocidad. Esta se diferencia de la tercera edad en cuanto a su funcionalidad. Es sabido que mientras menor sea la velocidad de la marcha en esta población, mayor es el riesgo de deterioro cognitivo, sarcopenia, discapacidad e institucionalización. La velocidad de marcha disminuida es un predictor importante de deterioro en el rendimiento físico. Objetivo. Determinar la correlación entre la velocidad de marcha, fuerza de miembros inferiores y largo del paso en personas mayores de cuarta edad que viven en la comunidad. Métodos. Estudio transversal en personas mayores saludables de la cuarta edad (n=14; 8 mujeres; 88 ± 3 años; 26,3 ± 3,4 kg·m-2) que fueron sometidas a evaluaciones de rendimiento físico, tales como largo del paso; fuerza de miembros inferiores a través de 1 Repetición Máxima (1RM) de extensión de rodilla en ambos miembros inferiores y velocidad de marcha en 4 metros. Los datos se presentan como media±desviación estándar. Se consideró un valor de P significativo < 0.05. Resultados. Se observó una correlación positiva moderada entre el largo del paso y la velocidad de marcha (R=0,794; P=0,001). No existieron correlaciones entre la fuerza de miembros inferiores y largo del paso (R=0,478; P=0,084), tampoco entre las variables de fuerza y velocidad de marcha (R=0,441; P=0.115). Conclusión. Las personas mayores de cuarta edad presentan una correlación positiva entre su velocidad de marcha y largo del paso.

Background. The population of people older than the fourth age (≥80 years) is growing rapidly. This differs from the third age in terms of its functionality. It is known that the lower the gait speed in this population, the greater the risk of cognitive impairment, sarcopenia, disability and institutionalization. Decreased gait speed is an important predictor of deterioration in physical performance. Objetive. To determine the correlation between gait speed, lower limb strength and stride length in fourth age people (≥80 years) who live in the community. Methods. Cross-sectional study in healthy older people of the fourth age (n=14; 8 women; 88 ± 3 years; 26.3 ± 3.4 kg·m-2) who underwent physical performance evaluations, such as long of the step; strength of lower limbs through 1 Maximum Repetition (1RM) of knee extension in both lower limbs and walking speed in 4 meters. Data are presented as mean ± standard deviation. A significant P value < 0.05 was considered. Results. A moderate positive correlation was observed between stride length and gait speed (R=0.794; P=0.001). There were no correlations between the strength of the lower limbs and stride length (R=0.478; P=0.084), nor between the variables of strength and gait speed (R=0.441; P=0.115). Conclusion. Fourth age older people older present a positive correlation between their walking speed and stride length.

Changes in Skeletal Muscle Protein Metabolism Signaling Induced by Glutamine Supplementation and Exercise.

AIM: To evaluate the effects of resistance exercise training (RET) and/or glutamine supplementation (GS) on signaling protein synthesis in adult rat skeletal muscles. METHODS: The following groups were studied: (1) control, no exercise (C); (2) exercise, hypertrophy resistance exercise training protocol (T); (3) no exercise, supplemented with glutamine (G); and (4) exercise and supplemented with glutamine (GT). The rats performed hypertrophic training, climbing a vertical ladder with a height of 1.1 m at an 80° incline relative to the horizontal with extra weights tied to their tails. The RET was performed three days a week for five weeks. Each training session consisted of six ladder climbs. The extra weight load was progressively increased for each animal during each training session. The G groups received daily L-glutamine by gavage (one g per kilogram of body weight per day) for five weeks. The C group received the same volume of water during the same period. The rats were euthanized, and the extensor digitorum longus (EDL) muscles from both hind limbs were removed and immediately weighed. Glutamine and glutamate concentrations were measured, and histological, signaling protein contents, and mRNA expression analyses were performed. RESULTS: Supplementation with free L-glutamine increased the glutamine concentration in the EDL muscle in the C group. The glutamate concentration was augmented in the EDL muscles from T rats. The EDL muscle mass did not change, but a significant rise was reported in the cross-sectional area (CSA) of the fibers in the three experimental groups. The levels of the phosphorylated proteins (pAkt/Akt, pp70S6K/p70S6K, p4E-BP1/4E-BP1, and pS6/S6 ratios) were significantly increased in EDL muscles of G rats, and the activation of p4E-BP1 was present in T rats. The fiber CSAs of the EDL muscles in T, G, and GT rats were increased compared to the C group. These changes were accompanied by a reduction in the 26 proteasome activity of EDL muscles from T rats. CONCLUSION: Five weeks of GS and/or RET induced muscle hypertrophy, as indicated by the increased CSAs of the EDL muscle fibers. The increase in CSA was mediated via the upregulated phosphorylation of Akt, 4E-BP1, p70S6k, and S6 in G animals and 4E-BP1 in T animals. In the EDL muscles from T animals, a decrease in proteasome activity, favoring a further increase in the CSA of the muscle fibers, was reported.

Trends in mortality from cardiovascular diseases in Chile, 2000-2020 / Tendencias de la mortalidad por enfermedades cardiovasculares en Chile, 2000-2020 / Tendências de mortalidade por doenças cardiovasculares no Chile, 2000-2020

ABSTRACT Objective. To analyze trends in mortality caused by cardiovascular diseases (CVD) in Chile during the period 2000-2020. Methods. Data on age-adjusted mortality rates (AAMR) from CVD per 100 000 population in Chile for 2000-2020 were extracted from the World Health Organization Mortality Database. Joinpoint regression was used to analyze the trends and compute the average annual percent change (AAPC) in Chile. In addition, analyses were conducted by sex and type of CVD. Results. Between 2000 and 2020, the AAMR from CVD decreased in Chile from 159.5 to 94.6 per 100 000 population, with a statistically significant decrease in the AAPC of 2.6% (95% CI [-2.8, -2.4]). No joinpoints were identified. The AAMR from CVD decreased annually by 2.6% (95% CI [-2.8, -2.4]) and 2.8% (95% CI [-3.5, -2.6]) in men and women, respectively. The AAMR from ischemic heart disease reduced annually by 3.6% (95% CI [-4.6, -2.7]) with two joinpoints in 2011 and 2015. In the case of stroke, the mortality rate decreased annually by 3.7% (95% CI [-4.5, -3.0]), with two joinpoints in 2008 and 2011. Conclusions. Cardiovascular disease mortality rates have decreased significantly in Chile, in both sexes, especially in women. This decrease could be explained mainly by a significant reduction in the case fatality in recent decades. These results could be a reference for developing primary prevention and acute management of CVD policies focused on populations with higher mortality.

RESUMEN Objetivo. Analizar las tendencias de la mortalidad por enfermedades cardiovasculares (ECV) en Chile durante el período 2000-2020. Métodos. Los datos sobre la tasa de mortalidad ajustada por la edad (TMAE) por ECV por 100 000 habitantes en Chile durante el período 2000-2020 se extrajeron de la base de datos de mortalidad de la Organización Mundial de la Salud. Se utilizó la regresión de tipo joinpoint (punto de cambio) para analizar las tendencias y calcular el cambio porcentual anual promedio (CPAP) en Chile. Además, se realizaron análisis por sexo y por tipo de ECV. Resultados. Entre el 2000 y el 2020, la TMAE por ECV disminuyó en Chile de 159,5 a 94,6 por 100 000 habitantes, con una disminución del CPAP estadísticamente significativa del 2,6% (IC del 95% [-2,8 a -2,4]). No se detectó ningún punto de cambio (joinpoint). La TMAE por ECV disminuyó anualmente un 2,6% (IC del 95% [-2,8 a -2,4]) en los hombres y un 2,8% (IC del 95% [-3,5 a -2,6]) en las mujeres. La TMAE por cardiopatía isquémica se redujo anualmente en un 3,6 % (IC del 95 % [-4,6 a -2,7]), encontrándose dos puntos de cambio en el 2011 y el 2015. En el caso de los ataques cerebrovasculares, la tasa de mortalidad disminuyó anualmente un 3,7% (IC del 95% [-4,5 a -3,0]), encontrándose dos puntos de cambio en el 2008 y el 2011. Conclusiones. La tasa de mortalidad por ECV ha disminuido significativamente en Chile en ambos sexos, pero en especial en las mujeres. Este descenso podría explicarse principalmente por la reducción significativa de la letalidad observada en las últimas décadas. Estos resultados podrían constituir una referencia para la elaboración de políticas de prevención primaria y manejo de casos agudos de ECV que estén centradas en aquellos grupos poblacionales donde la mortalidad es más alta.

RESUMO Objetivo. Analisar as tendências de mortalidade causada por doenças cardiovasculares (DCV) no Chile no período de 2000 a 2020. Métodos. Taxas de mortalidade por DCV ajustadas por idade no Chile referentes ao período de 2000 a 2020 foram extraídas do Banco de Dados de Mortalidade da Organização Mundial da Saúde. Foi usado um modelo de regressão linear segmentada (joinpoint) para analisar tendências e calcular a variação percentual média anual no Chile. Além disso, foram realizadas análises por sexo e tipo de DCV. Resultados. No Chile, entre 2000 e 2020, a taxa de mortalidade por DCV ajustada por idade caiu de 159,5 para 94,6 por 100 mil habitantes, com uma redução estatisticamente significante da variação percentual média anual de 2,6% (IC de 95% [-2,8; -2,4]). Não foram identificados pontos de inflexão. Anualmente, a taxa de mortalidade por DCV ajustada por idade caiu 2,6% (IC 95% [-2,8; -2,4]) e 2,8% (IC 95% [-3,5; -2,6]) entre homens e mulheres, respectivamente. A taxa de mortalidade por doença cardíaca isquêmica ajustada por idade caiu 3,6% (95% CI [-4,6; -2,7]) por ano, com dois pontos de inflexão (em 2011 e 2015). No caso do acidente vascular cerebral, a taxa de mortalidade diminuiu 3,7% (IC de 95% [-4,5; -3,0]) por ano, com dois pontos de inflexão (em 2008 e 2011). Conclusões. As taxas de mortalidade por doenças cardiovasculares diminuíram significativamente no Chile em ambos os sexos, especialmente nas mulheres. Essa queda pode ser explicada principalmente por uma redução significativa na letalidade observada nas últimas décadas. Esses resultados podem ser uma referência para o desenvolvimento de políticas de prevenção primária e manejo de casos agudos de DCV voltadas para populações com maiores taxas de mortalidade.

Calidad de vida, nivel de actividad física y pruebas funcionales en personas adultas y mayores laboralmente activas / Quality of life, level of physical activity and functional tests in actively working adults and older people

BACKGROUND: The population of actively working older people is growing rapidly. The relationship between quality of life, levels of physical activity and functionality in this population is not entirely clear. AIM: To determine the association between quality of life, levels of physical activity and functional tests in actively working adults and older people. MATERIAL AND METHODS: Cross sectional assessment of 138 adults aged 40 to 50 years (53% women) and 119 older people aged 60 to 75 years (53% women) who were actively working in two public services. Quality of life was measured with the SF-36 questionnaire and usual physical activity was assessed with the International Physical Activity Questionnaire (IPAQ-short). Handgrip strength, the timed up and go (TUG) and chair stand test (CST) were used as functional tests. RESULTS: Compared to older people, adults had better physical functional tests (P < 0.01). Older people had better scores in the mental health component (MHC) of quality of life (p < 0.05). In adults, the physical health component of quality of life (CSF) had a positive association with physical activity (Spearman Rho (rs)= 0.270; p = 0.01), grip strength (rs = 0.330; p < 0.01) and the TUG (rs = −0.229; p < 0.01). In older patients, CSM and CST were positively correlated (rs = 0.201; P = 0.029). In both groups, a correlation was observed between CSM, grip strength (adults rs = 0.283; p < 0.01; older people rs = 0.211; P = 0.02) and with TUG (adults rs = −0.197; P = 0.021; older people rs = - 0.212; p = 0.02). CONCLUSIONS: There is a positive correlation between quality of life and level of physical activity in working adults, which is not observed in older people. Adequate performance in physical functional tests is positively correlated with better quality of life (CSF and CSM) in adults and only with the mental health component in older people.

Physical therapy protocols to attenuate skeletal muscle atrophy in critically ill patients: narrative review / Protocolos de terapia física para atenuar la atrofia del músculo esquelético en pacientes críticos: revisión narrativa

SUMMARY: To describe the physical therapy protocols used in critically ill patients to attenuate skeletal muscle atrophy. We conducted a search in PubMed and Embase from inception to November 2020. Observational or experimental studies published in English or Spanish that evaluated the effect of physical therapy protocols on the attenuation of skeletal muscle atrophy in critically ill patients through muscle strength or mass measurement were considered eligible. Studies were only included if they reported a detailed description of the dosing of the interventions. Seventeen studies met the eligibility criteria. We included randomised clinical trials (n = 16) and observational studies (n = 1). The total population of the included studies was 872 critically ill patients. The studies aimed to evaluate the reliability, safety or effectiveness of neuromuscular electrical stimulation (n = 10) protocols, early mobilisation (n = 3), ergometer training (n = 2), transfers in tilt table (n = 1), and blood flow restriction (n = 1). Physical therapy protocols are part of the critically ill patient's integral management. Strategies such as passive mobilisation, in-bed and out-of-bed transfers, gait training, ergometer training, and neuromuscular electrical stimulation substantially impact critically ill patients' prognoses and quality of life after hospital discharge.

RESUMEN: Describir los protocolos de terapia física usados en pacientes críticos para atenuar la atrofia muscular esquelética. Realizamos una búsqueda en PubMed y Embase desde el inicio hasta noviembre de 2020. Se consideraron los estudios observacionales o experimentales publicados en inglés o español que evaluaron el efecto de los protocolos de terapia física en la atenuación de la atrofia del músculo esquelético en pacientes críticos a través de la medición de la fuerza o la masa muscular. Los estudios solo se incluyeron si informaron una descripción detallada de la dosificación de las intervenciones. Diecisiete estudios cumplieron los criterios de elegibilidad. Se incluyeron ensayos clínicos aleatorizados (n = 16) y estudios observacionales (n = 1). La población total de los estudios incluidos fue de 872 pacientes en estado crítico. Los estudios tuvieron como objetivo evaluar la confiabilidad, seguridad o efectividad de los protocolos de estimulación eléctrica neuromuscular (n = 10), movilización temprana (n = 3), entrenamiento con ergómetro (n = 2), transferencias en mesa basculante (n = 1) y restricción del flujo sanguíneo (n = 1). Los protocolos de terapia física forman parte del manejo integral del paciente crítico. Es- trategias como la movilización pasiva, los traslados dentro y fuera de la cama, el entrenamiento de la marcha, el entrenamiento con ergómetro y la estimulación eléctrica neuromuscular tienen un impacto sustancial en el pronóstico y la calidad de vida de los pacientes críticos después del alta hospitalaria.

Two-Minute Step Test as a Complement to Six-Minute Walk Test in Subjects With Treated Coronary Artery Disease.

The 2-Minute Step Test (2MST) has been presented as an alternative to the 6-Minute Walk Test (6MWT) based on the association between the two tests in older adults; however, some authors propose that it should not be a substitute but rather a complement to the latter in the fitness evaluation. Specifically, in coronary disease, despite the potential and clinical utility of 2MST, the relationship of both tests in this population is unknown. This study aimed to determine the relationship between 6MWT and 2MST and to explore the relationship of biodemographic factors for both tests in subjects with treated coronary artery disease. For this, the 6MWT and the 2MST were applied to patients with coronary artery disease treated in 6 hospitals in Chile between May 2019 and February 2020. Additionally, lower limb strength was assessed by a chair-stand test, grip strength was assessed by a dynamometer, and physical measurements were applied. In total, 163 participants underwent both tests (average age = 58.7 ± 9.8 years; 73.6% men; 64.4% revascularized by angioplasty; 28.2% revascularized by surgery, and 7.4% treated by drugs or thrombolysis). Heart rate was higher at the end of the 6MWT, while the perception of effort was greater at the end of the 2MST. There was a weak positive correlation between the 6MWT and the 2MST in subjects with treated coronary disease (r = 0.28, p = 0.0003). While age (r = -0.27), weight (r = 0.25), height (r = 0.49), and strength of both lower limbs (r = 0.41) and grip strength (r = 0.53) correlated weakly or moderately to the covered distance in 6MWT, the number of steps by the 2MST correlated only weakly to height (r = 0.23), lower limb strength (r = 0.34), and grip strength (r = 0.34). Age, weight, height, lower limb strength, and grip strength would explain better the meters walked in the 6MWT than the steps achieved in the 2MST. With these findings, we can conclude that, in patients with treated coronary artery disease, it does not seem advisable to replace 6MWT with 2MST when it is possible to do so. Additionally, the 2MST may provide additional information in the fitness evaluation. However, the usefulness of 2MST in this population needs to be further studied.

Anthropometric parameters, lower limb functionality and quality of life after high-intensity interval training in healthy young people versus older adults / Parámetros antropométricos, funcionalidad de miembros inferiores y calidad de vida posterior al entrenamiento interválico de alta intensidad en jóvenes versus personas mayores

SUMMARY: The aim of this study was to determine the effects of High-intensity interval training (HIIT) on the quality of life in healthy young people (YNG) and older adults (OLD)and its correlation with physical health status (anthropometric parameters and lower limb functionality) YNG (21 ? 2 years, BMI 26.37 ? 2.69 n = 12) and OLD (67 ? 5 years, BMI 27.16 ? 3.04 n = 12) groups underwent 12weeks of HIIT. Before and after the HIIT, anthropometric assessments, lower limb functionality tests, and SF-36 quality-of-life questionnaire were performed. There were no significant changes in the SF-36 dimensions (P>0.05). After HIIT, there were improvement percentage changes in Mental Component Summary (MCS) (YNG, +8.51 ? 25.80 % vs. OLD, +2.30 ? 9.05 %) and in Physical Component Summary (PCS) (YNG, +2.66 ? 20.54 % vs. OLD, +4.34 ? 22.71 %). Negative correlations were observed between body mass index (BMI) with PCS (R=-0.570, P=0.009) and with MCS (R=-0.649, P=0.002) in OLD as well as between MCS and waist circumference (R=-0.557, P?0.001) in both groups. Also, correlations were observed between PCS and the sit-to-stand test (R=-0.424, P=0.006) in both groups and gait speed (R=0.458, P=0.042) only in YNG. HIIT promotes positive percentage changes in quality of life, with YNG showing better results in PCS and OLD in MCS. Quality of life and physical health status were correlated in both groups.

RESUMEN: Determinar los efectos del entrenamiento interválico de alta intensidad (HIIT) sobre la calidad de vida en jóvenes sanos (YNG) y personas mayores (OLD) y su correlación con el estado de salud física (parámetros antropométricos y funcionalidad de miembros inferiores). Ambos grupos, YNG (21 ? 2 años, IMC 26,37 ? 2,69 n = 12) y OLD (67 ? 5 años, IMC 27,16 ? 3,04 n = 12) realizaron 12 semanas de HIIT. Antes y después del HIIT, se realizaron evaluaciones antropométricas, pruebas de funcionalidad de miembros inferiores y cuestionario de calidad de vida SF-36. No hubo cambios significativos en las dimensiones del SF-36 (P >0,05). Después del HIIT, hubo cambios porcentuales de mejora en el componente sumario mental (MCS) (YNG, +8.51 ? 25.80 % vs. OLD, +2.30 ? 9.05 %) y el componente sumario física (PCS) (YNG, +2,66 ? 20,54 % vs. OLD, +2,30 ? 9,05 %), correspondientes a la calidad de vida. Se observaron correlaciones negativas entre el índice de masa corporal (IMC) con PCS (R=-0,570; P=0,009) y con MCS (R=0,649; P=0,002) en OLD, así como entre MCS y circunferencia de cintura (R = - 0,557, P?0,001) en ambos grupos. Además, se observaron correlaciones entre PCS y la prueba de sentarse y levantarse (R = -0,424; P = 0,006) en ambos grupos y la velocidad de la marcha (R = 0,458; P = 0,042) solo en YNG. HIIT promueve cambios porcentuales positivos en la calidad de vida, con YNG mostrando mejores resultados en PCS y OLD en MCS. La calidad de vida y el estado de salud física se correlacionaron en ambos grupos.

Endoplasmic Reticulum Stress and Autophagy Markers in Soleus Muscle Disuse-Induced Atrophy of Rats Treated with Fish Oil.

Endoplasmic reticulum stress (ERS) and autophagy pathways are implicated in disuse muscle atrophy. The effects of high eicosapentaenoic (EPA) or high docosahexaenoic (DHA) fish oils on soleus muscle ERS and autophagy markers were investigated in a rat hindlimb suspension (HS) atrophy model. Adult Wistar male rats received daily by gavage supplementation (0.3 mL per 100 g b.w.) of mineral oil or high EPA or high DHA fish oils (FOs) for two weeks. Afterward, the rats were subjected to HS and the respective treatments concomitantly for an additional two-week period. After four weeks, we evaluated ERS and autophagy markers in the soleus muscle. Results were analyzed using two-way analysis of variance (ANOVA) and Bonferroni post hoc test. Gastrocnemius muscle ω-6/ω-3 fatty acids (FAs) ratio was decreased by both FOs indicating the tissue incorporation of omega-3 fatty acids. HS altered (p < 0.05) the protein content (decreasing total p38 and BiP and increasing p-JNK2/total JNK2 ratio, and caspase 3) and gene expressions (decreasing BiP and increasing IRE1 and PERK) of ERS and autophagy (decreasing Beclin and increasing LC3 and ATG14) markers in soleus. Both FOs attenuated (p < 0.05) the increase in PERK and ATG14 expressions induced by HS. Thus, both FOs could potentially attenuate ERS and autophagy in skeletal muscles undergoing atrophy.

Estaciones de aprendizaje para abordar concepciones de fisiología y morfología sobre el concepto de célula / Learning stations to analyze physiology and morphology perceptions of the cell concept

RESUMEN: El objetivo del presente estudio fue determinar la influencia de la implementación y aplicación de la metodología de enseñanza estaciones de aprendizaje, sobre un aprendizaje activo de la fisiología y morfología de la célula. Se trabajó con 90 estudiantes de enseñanza secundaria, distribuidos en un grupo control y otro experimental, los cuales recibieron clases tradicionales y la aplicación de la metodología estaciones de aprendizaje, respectivamente. Los datos fueron recolectados en base a test de concepciones y conocimientos, más encuesta de valoración. El análisis de los datos reveló que las estaciones de aprendizaje son una metodología de enseñanza efectiva en el aprendizaje de la célula, ya que permiten mejorar significativamente las concepciones previas de los estudiantes, los cuales valoran de manera positiva y significativa la metodología de la que fueron partícipes.

SUMMARY: The aim of this study was to determine the influence of the implementation and application of the learning stations teaching methodology on active learning of the physiology and morphology of the cell. We worked with 90 high school students, distributed in a control group and an experimental group, who received traditional classes and the application of the learning stations methodology, respectively. The data were collected based on a conception and knowledge test, plus an evaluation survey. The analysis of the data revealed that the learning stations are an effective teaching methodology in learning of the cell, since they allow to improve prior perceptions of the students, who significantly and positively value the methodology in which they participated.

Pre-existing conditions in Latin America and factors associated with adverse outcomes of COVID-19: A review.

The coronavirus disease 2019 (COVID-19) pandemic, produced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread rapidly throughout the world. Latin American and the Caribbean countries have been harshly affected by the pandemic mainly due to less prepared healthcare systems and fragmented social safety nets. In the region, health status population-based indicators are worse than compared to the Organization for Economic Cooperation and Development. Recent evidence suggests that the progression and severity of COVID-19 are associated with the prior health status of individuals, and studies have shown that the case fatality rate is highly stratified among different populations. This narrative review aims to describe factors associated with adverse outcomes of COVID-19 in the context of social determinants of health in Latin American and Caribbean countries. In this review, we state that genetic and biological factors interact in a sophisticated way with social determinants of health, impacting the rapid spread of COVID-19 in Latin American and Caribbean countries. Behavioral factors, such as physical inactivity, smoking, and unhealthy diets, are related to chronic systemic inflammation. Also, air pollution can prolong inflammation and the hyper-activation of the immune system. Air pollutants could facilitate the spread of the virus. Finally, frailty and comorbidities can be associated with COVID-19 severity through increasing vulnerability to stressors and leading to more severe symptoms of COVID-19 disease, including a higher mortality risk. All these factors contribute to increasing the impact of COVID-19 in Latin American and Caribbean countries. We highlight the relevance of considering social determinants of health in Latin American and the Caribbean countries, not only in controlling the likelihood of getting the disease but also its progression and severity. All these social determinants can guide the design and implementation of tailored interventions promoting healthy lifestyle behaviors, which should lower the spread of the disease, its severity, and lethality.

La pandemia de la enfermedad por coronavirus 2019 (COVID-19), producida por el virus SARS-CoV-2, se ha diseminado rápidamente a través del mundo. Los países de Latinoamérica y el Caribe han sido afectados duramente por la pandemia principalmente debido a falta de preparación de sus sistemas de salud y debido al fragmentado sistema de seguridad social. Además, en la región, el estado de salud de la población muestra peores indicadores de salud comparado con los países de la Organización para la Cooperación y el Desarrollo Económico. Evidencia reciente sugiere que la progresión y severidad de la COVID-19 están asociadas con el estado de salud basal del individuo, y algunos estudios han mostrado que la letalidad está altamente estratificada entre diferentes poblaciones. El objetivo de esta revisión narrativa es describir los factores asociados con peor evolución de la COVID-19 en el contexto de los determinantes sociales de la salud en los países de Latinoamérica y el Caribe. En esta revisión, se indica que los factores biológicos y genéticos interactúan de una manera sofisticada con los determinantes sociales de la salud, impactando la rápida diseminación de la COVID-19 en los países de Latinoamérica y el Caribe. Factores del comportamiento, como la inactividad física, fumar, y una dieta poco saludable, están relacionadas con una inflamación sistémica crónica. Además, la contaminación ambiental puede prolonger la inflamación y la hiperactivación del sistema inmune. Las partículas contaminantes del aire pueden facilitar la dispersión del virus. Finalmente, el síndrome de fragilidad y las comorbilidades están asociadas con severidad de la COVID-19, aumentando la vulnerabilidad ante factores estresantes y provocando síntomas más graves de la enfermedad COVID-19, aumentando el riesgo de mortalidad. Todos los factores mencionados, contribuyen a aumentar el impacto de la pandemia por COVID-19 en los países de Latinoamérica y el Caribe. Destacamos la relevancia de considerar los determinantes sociales de la salud en los países de Latinoamérica y el Caribe, no sólo para controlar el riesgo de contagio, sino también la progresión y severidad de la enfermedad. Los determinantes sociales pueden guiar el diseño y la implementación de intervenciones para promover los estilos de vida saludable, que puede contribuir a reducir la diseminación de la enfermedad, su severidad y letalidad.

Efectos del tratamiento con quimioterapia y radioterapia concomitante sobre los volúmenes pulmonares en mujeres con cáncer de mama en Talca, Chile / Effects of concurrent chemotherapy and radiotherapy on lung volumes in women with breast cancer living in Talca, Chile

Resumen Introducción. El cáncer de mama (CM) es la enfermedad crónica no transmisible más frecuente y letal en mujeres. La información disponible sobre el impacto de sus diversos tratamientos en el sistema respiratorio es controversial. Objetivo. Determinar el efecto del tratamiento con quimioterapia y radioterapia concomitante en los volúmenes pulmonares de un grupo de mujeres con CM en Talca, Chile. Materiales y métodos. Estudio de casos y controles. La muestra (n=22) se dividió en dos grupos: control (n = 11) y con CM (n = 11). Para medir la capacidad vital forzada, los volúmenes pulmonares y la resistencia de las vías aéreas, se usó la prueba de pletismografía corporal. Para determinar la normalidad de los datos, se usó la prueba Shapiro-Wilks y, según sus resultados, se utilizó la prueba de t-Student o la de U de Mann-Whitney; se consideró un nivel de significancia de p<0.05. Resultados. Los flujos ventilatorios no presentaron diferencias significativas entre los dos grupos, mientras que los volúmenes pulmonares en el grupo con CM experimentaron una disminución significativa en las variables capacidad inspiratoria (CI) y volumen residual (VR) (p<0.05). Conclusión. Las mujeres con CM y que fueron tratadas con quimioterapia y radioterapia concomitante experimentaron una disminución en su CI y su VR en comparación con el grupo control, lo que podría impactar su calidad de vida.

Abstract Introduction: Breast cancer (BC) is the most frequent and lethal chronic non-communicable disease in women, and available information on the impact that the different treatments for BC have on the respiratory system is controversial. Objective: To determine the effect of concurrent chemotherapy and radiotherapy on lung volumes in a group of women with BC living in Talca, Chile. Material and methods: Case-control study. The sample (n=22) was divided into two groups: control (n=11) and BC (n=11). A whole body plethysmography test was used to measure participants' forced vital capacity, lung volumes, and airway resistance. The Shapiro-Wilks test was used to determine the normality of data, and, according to the result of this test, the Student's t test or the Mann-Whitney U test were used. A significance level of p<0.05 was considered. Results: Ventilatory flows showed no significant differences between both groups, while lung volumes in the BC group experienced a significant decrease in the inspiratory capacity (IC) and residual volume (RV) variables (p<0.05). Conclusion: Compared to the CG, the women with BC who received concurrent chemotherapy and radiotherapy experienced a reduction of their IC and RV, which could affect their quality of life.

Effectiveness of short-term physical agents treatment on macroscopic morphology in patients with plaque psoriasis / Efectividad del tratamiento a corto plazo de los agentes físicos en la morfología macroscópica de las placas de psoriasis

Psoriasis is a chronic inflammatory disease that presents skin rashes which can arise through plaques. The aim of this work was to compare the effectiveness of short-term physical agents treatment on macroscopic morphology (area and erythema) in patients with plaque psoriasis. This prospective randomized experimental study included fourteen subjects, medically diagnosed with psoriasis, with more than one plaque in the skin and voluntarily without topical treatment. All subjects completed the study that consisted of 12 treatment sessions divided in control (C), artificial balneotherapy (AB), phototherapy (PT) or balneophototherapy (BPT) groups. After session 12, there was a significant reduction of the plaque area by all treatments when compared to C group and BPT was the most effective one. However, only AB and PT presented a reduction of erythema. Regarding severity, 9 patients changed to a lower category on the PASI test, and 5 of them maintained a mild psoriasis, but lowered their score. Finally, 13 of 14 subjects improved their quality of life. The physical agents used reduced the severity of psoriasis and improved quality of life of patients after 12 sessions of treatment during a onemonth period. The BPT was the more effective in controlling psoriasis by diminishing its area and PT by attenuating the erythema.

La Psoriasis es una enfermedad inflamatoria crónica que presenta irritación cutánea que puede derivar a placas. El objetivo de este trabajo fue comparar la efectividad del tratamiento a corto plazo con agentes físicos en la morfología macroscópica (área y eritema) en pacientes con placas de psoriasis. Estudio experimental, prospectivo, randomizado. Catorce sujetos participaron con diagnóstico médico de psoriasis, con más de una placa en la piel y sin tener tratamiento tópico de forma voluntaria. Todos los sujetos completaron el estudio, el cual consistió de 12 sesiones de tratamiento dividido en grupo control (C), BA, FT y BFA. Posterior a la sesión 12, se observó una reducción significativa en toda el área de las placas que recibieron tratamiento al compararlas al grupo C y el grupo BFA fue el más efectivo. Sin embargo, solo los grupos BA y FT presentaron una reducción del eritema. Respecto a la severidad, 9 pacientes cambiaron de la baja categoría en el test de PASI y 5 de ellos se mantuvieron en el nivel medio, pero disminuyeron su puntaje. Finalmente, 13 de 14 sujetos mejoraron su calidad de vida. Los agentes físicos usados redujeron la severidad de la psoriasis y mejoraron la calidad de vida de los pacientes después de 12 sesiones de tratamiento durante el período de un mes. La BFA fue la más efectiva en controlar la psoriasis por la disminución en el área y la FT por la atenuación del eritema.

Alcances de la confiabilidad en la medición antropométrica: un aporte para el escalonamiento de la formación competente en pregrado, una experiencia piloto / Scope of reliability in anthropometric measurement: a contribution for the staggering of the undergraduate competency formation, a pilot experience

El objetivo de la presente investigación fue determinar el nivel de confiabilidad de las mediciones antropométricas relacionadas al tórax, realizadas por un estudiante de licenciatura en kinesiología (ELK) comparandolas con las de un antropometrista experto (AE). El proceso consistió en el escalonamiento de competencias dividido en tres etapas: i) desarrollo de competencias teóricas y prácticas, ii) Determinar idea de investigación y construcción de su marco teórico y iii) adquisición de confiabilidad, el ELK realizó este ejercicio en relación al AE International Society for the Advancement of Kinanthropometry (ISAK) II. Para este punto, se reclutaron seis participantes, los cuales fueron aleatorizados y medidos por ambos evaluadores. Se registraron los diámetros, perímetros y pliegues relacionados al tórax utilizando los protocolos de la ISAK, para posteriormente calcular el error técnico de la medición (ETM) y el coeficiente de correlación de concordancia de Lin (CCC). El ETM fue el aceptado para diámetros, perímetros y pliegues, salvo en el valor del pliegue bicipital, el que mostró un 5,60 %. La fuerza de la relación fue moderada a sustancial en perímetros y pliegues y pobre en los diámetros entre el ELK y el AE. En conclusión, el ETM se encontró dentro de los rangos permitidos salvo el pliegue bicipital. Sin embargo, ELK mostró un nivel de concordancia moderado a sustancial en perímetros y pliegues y pobre en diámetros de tórax en relación al AE.

The aim of the present investigation was to determine the reliability level of the anthropometric measurements related to the thorax performed by an undergraduate student in kinesiology (ELK) comparing them with those of an expert anthropometrist (AE). The process consisted of the staging of competencies divided into three stages: i) development of theoretical and practical skills, ii) Determine the idea of research and construction of its theoretical framework and iii) acquisition of reliability, the ELK carried out this exercise in relation to the AE International Society for the Advancement of Kinanthropometry (ISAK) II. For this point, five participants were recruited, which were randomized and measured by both evaluators. The diameters, perimeters and folds related to the thorax were recorded using the ISAK protocols, to calculate the technical error of the measurement (ETM) and the correlation coefficient of Lin's concordance (CCC). The ETM was accepted for diameters, perimeters and folds, except for the bicipital fold value, which showed a 5.60 %. The relationship strength was moderate to substantial in perimeters and folds and poor in the diameters between the ELK and the AE. In conclusion, the ETM was found within the permitted ranges except for the bicipital fold. However, ELK showed a moderate to substantial level of agreement in perimeters and folds and poor in chest diameters in relation to AE.

Sarcomere structure: the importance of desmin protein in muscle atrophy / Estructura de sarcómera: la importancia de proteína desmina en atrofia muscular

Knowing the ultrastructure of skeletal muscle is critical to understand how it works under normal situation and the disorders caused by extreme or pathological conditions. Sarcomere is the basic structural unit of striated muscle tissue. An important element of sarcomere architecture are the intermediate filaments, including the desmin protein. Desmin protein contributes to maintenance of cell integrity, efficient transmission of force and mechanochemical signaling within the myocyte. Because of this, desmin protein has constantly been a focus of research that investigates its alterations associated to damage and muscle atrophy under different conditions. The purpose of the following literature review is to describe the basic concepts of muscle ultrastructure, emphasizing the desmin protein role under conditions of muscle disuse atrophy and aging.

Conocer la ultraestructura del músculo esquelético es crítico para entender cómo trabaja bajo situaciones normales y en desórdenes causados por condiciones extremas o patológicas. La sarcómera es la unidad de estructura básica del tejido muscular estriado. Elementos importantes en la arquitectura de la sarcómera son los filamentos intermedios, incluyendo la proteína desmina. La proteína desmina contribuye en mantener la integridad celular, la transmisión eficiente de fuerza y la señalización mecanoquímica dentro del miocito. Debido a lo anterior, la proteína desmina ha sido constante foco de investigación en trabajos que estudian sus alteraciones asociadas a daño y atrofia muscular bajo diferentes condiciones. El propósito de la siguiente revisión de la literatura es describir los conceptos básicos de la ultraestructura muscular, enfatizando en el rol de la proteína desmina bajo condiciones de atrofia muscular por desuso y envejecimiento.

Experimental Model of Skeletal Muscle Laceration in Rats.

This is a modified experimental model previously developed in mouse to study skeletal muscle laceration in rats. All experimental procedures are performed during the light period, including anesthesia and surgery. The animals are randomly distributed into control and injured groups prior to the procedure. This experimental model can be used to investigate skeletal muscle laceration repair.

Effects of high EPA and high DHA fish oils on changes in signaling associated with protein metabolism induced by hindlimb suspension in rats.

The effects of either eicosapentaenoic (EPA)- or docosahexaenoic (DHA)-rich fish oils on hindlimb suspension (HS)-induced muscle disuse atrophy were compared. Daily oral supplementations (0.3 mL/100 g b.w.) with mineral oil (MO) or high EPA or high DHA fish oils were performed in adult rats. After 2 weeks, the animals were subjected to HS for further 2 weeks. The treatments were maintained alongside HS At the end of 4 weeks, we evaluated: body weight gain, muscle mass and fat depots, composition of fatty acids, cross-sectional areas (CSA) of the soleus muscle and soleus muscle fibers, activities of cathepsin L and 26S proteasome, and content of carbonylated proteins in the soleus muscle. Signaling pathway activities associated with protein synthesis (Akt, p70S6K, S6, 4EBP1, and GSK3-beta) and protein degradation (atrogin-1/MAFbx, and MuRF1) were evaluated. HS decreased muscle mass, CSA of soleus muscle and soleus muscle fibers, and altered signaling associated with protein synthesis (decreased) and protein degradation (increased). The treatment with either fish oil decreased the ratio of omega-6/omega-3 fatty acids and changed protein synthesis-associated signaling. EPA-rich fish oil attenuated the changes induced by HS on 26S proteasome activity, CSA of soleus muscle fibers, and levels of p-Akt, total p70S6K, p-p70S6K/total p70S6K, p-4EBP1, p-GSK3-beta, p-ERK2, and total ERK 1/2 proteins. DHA-rich fish oil attenuated the changes induced by HS on p-4EBP1 and total ERK1 levels. The effects of EPA-rich fish oil on protein synthesis signaling were more pronounced. Both EPA- and DHA-rich fish oils did not impact skeletal muscle mass loss induced by non-inflammatory HS.