The exponential growth of human interactions on social media via the internet has revolutionized global communication, but it has also emerged as a critical factor in mental health linked to suicidal ideation and mental disorders. This systematic review and meta-analysis aimed to synthesize evidence on the most prevalent disorders in adolescents and young adults associated with social media use based on previous research, highlighting risk factors and key findings. Publications from 2020 to 2024 in highly relevant databases were reviewed following the PRISMA declaration guidelines. The meta-analysis (conducted in R software) of the included documents (24 studies, 68 effects) verified a significant and positive association between exposure to risk factors in social networks and various disorders in adolescents and young adults (aggregate correlation r = 0.2173, 95% CI [0.1826, 0.2520], p ≤ 0.0001), although with high heterogeneity (I2 = 99.66%). Prevention strategies were indicated by revealing data from contexts in which 40% of adolescents who died by suicide had developed online identities focused on suicidal thoughts.
Heart rate asymmetry (HRA) refers to how asymmetrically the acceleration and deceleration patterns in heartbeat fluctuations are distributed. There is limited evidence regarding HRA changes in athletes and their association with autonomic regulation. This study aimed to compare the short-term HRA of high-performance athletes and non-athletes during an autonomic function test by calculating relevant HRA measures. This exploratory study obtained beat-to-beat RR interval time series from 15 high-performance athletes and 12 non-athletes during a standardized autonomic function test. This test includes rest, postural change, controlled respiration, prolonged orthostatism, exercise, and recovery phases. The following HRA parameters were computed from the RR time series for both groups: asymmetric spread index (ASI), slope index (SI), Porta’s index (PI), Guzik’s index (GI), and Ehlers’ index (EI). We found significant differences (p < 0.01) in the mean value of several HRA parameters between athletes and non-athletes and across the autonomic function test phases, mainly in postural change and recovery phases. Our results indicate that high-performance athletes manifest a higher number and magnitude of cardiac decelerations than non-athletes after an orthostatic challenge, as indicated by GI and EI. In addition, lower HRA was found in athletes in the recovery phase than in non-athletes, as indicated by ASI.
DNA methylation and histone posttranslational modifications are epigenetics processes that contribute to neurophenotype of Down Syndrome (DS). Previous reports present strong evidence that nonhistone high-mobility-group N proteins (HMGN) are epigenetic regulators. They play important functions in various process to maintain homeostasis in the brain. We aimed to analyze the differential expression of five human HMGN genes in some brain structures and age ranks from DS postmortem brain samples. Methodology: We performed a computational analysis of the expression of human HMGN from the data of a DNA microarray experiment (GEO database ID GSE59630). Using the transformed log2 data, we analyzed the differential expression of five HMGN genes in several brain areas associated with cognition in patients with DS. Moreover, using information from different genome databases, we explored the co-expression and protein interactions of HMNGs with the histones of nucleosome core particle and linker H1 histone. Results: We registered that HMGN1 and HMGN5 were significantly overexpressed in the hippocampus and areas of prefrontal cortex including DFC, OFC, and VFC of DS patients. Age-rank comparisons between euploid control and DS individuals showed that HMGN2 and HMGN4 were overexpressed in the DS brain at 16 to 22 gestation weeks. From the BioGRID database, we registered high interaction scores of HMGN2 and HMGN4 with Hist1H1A and Hist1H3A. Conclusions: Overall, our results give strong evidence to propose that DS would be an epigenetics-based aneuploidy. Remodeling brain chromatin by HMGN1 and HMGN5 would be an essential pathway in the modification of brain homeostasis in DS.
1 January 2021 in Revista Brasileira de Medicina do Esporte
Introduction Blood biomarkers are measurable metabolic products that allow objective monitoring of the training process, and their analysis provides an opportunity to improve athletic performance. Objective To evaluate blood lactate concentrations in a group of the Valle League weightlifting athletes as a tool to determine the effects of training and its direct relationship to performance during competition. Methods This is an observational cross-sectional study. Lactate levels of 32 weightlifting athletes belonging to the Valle Weightlifting League were evaluated. Blood samples were taken from the ear lobe to quantify the lactate concentration, using a Scout Lactate analyzer. Samples were taken before and after a high intensity training section consisting of four maximum repetition (MR) sports gestures, in which 5 series and 15 repetitions were performed for each sports gesture, with a rest period of 40 seconds between each exercise. The software program SPSS, version 25, was used to determine the lactate concentrations. Results An average lactate concentration 22.46 mg/dL was obtained for the athletes at rest, and an average of 98.30 mg/dL in the final lactate concentration, after high intensity exercise. Significant differences were found between the initial and final lactate concentrations. Conclusion Lactate concentration increases with physical activity; it varies from one individual to another; and it can be used as a biomarker of intensity of physical activity in the field of sports. Level of evidence; II type of study: Prognostic Studies Investigating the Effect of a Patient Characteristic on a disease outcome.
1 January 2021 in Journal of Human Sport and Exercise
Este estudio determino el impacto de un programa de entrenamiento destinado a mejorar la potencia mediante la sentadilla profunda y la media sentadilla. Participaron nueve atletas registrados en la Liga Vallecaucana de Ciclismo. Se realizaron mediciones de tiempo en una distancia de 60 metros con salida detenida en bicicleta, así como el salto contra movimiento (CMJ) y la repetición máxima (RM) antes y después de un periodo de entrenamiento de 4 semanas. Los participantes se distribuyeron en tres grupos: el grupo 1 realizó la media sentadilla, el grupo 2 llevó a cabo la sentadilla profunda, y el grupo 3 se sometió a ambos ejercicios. Se observaron cambios significativos en los valores de tiempo en los 60 metros para el grupo 2, que mejoró (de 9.35 s ± 1.18 s a 9.19 s ± 1.19 s), en contraste con los otros dos grupos que no experimentaron mejoras significativas. El grupo 2 también mostró mejoras en los valores de CMJ (de 37.24 cm ± 6.22 cm a 40.75 cm ± 5.12 cm), al igual que el grupo 3 (de 33.17 cm ± 3.12 cm a 35.07 cm ± 5.56 cm). En cambio, el grupo 1 no presentó mejorías en estos resultados. En cuanto a la RM, todos los grupos superaron sus marcas iniciales. En resumen, el ejercicio de sentadilla profunda demostró ser más efectivo para mejorar el rendimiento en todas las pruebas, incluso con un periodo de entrenamiento breve, independientemente del ángulo de ejecución del ejercicio.