Technical Report: Efficacy and Safety of Low-Intensity Transcranial Magnetic Stimulation in the Remission of Depressive Symptoms in Patients With Treatment-Resistant Depression in Mexico.

Transcranial magnetic stimulation (TMS) is a non-invasive neuromodulation technique that induces action potentials in the stimulated cortical area and has been approved by the Food and Drug Administration (FDA) for the treatment of major depressive disorder (MDD). The prevalence of MDD in Mexico almost tripled after the COVID-19 pandemic. In this study, we evaluated the safety and therapeutic effects of low-intensity TMS (Li-TMS) - characterized by inducing electric currents below the action potential threshold on the cerebral cortex - in 41 subjects diagnosed with treatment-resistant depression (TRD). A Li-TMS device dispensed repetitive magnetic pulses at 30 mT for 60 minutes during 20 sessions (once daily from Monday to Saturday) with the theta burst pattern. Our results suggest that Li-TMS is a safe therapy with antidepressant effects, demonstrated by the decrease in Beck Depression Inventory (BDI) scores and lessening of depressive symptoms.

Analysing the effect caused by increasing the molecular volume in M1-AChR receptor agonists and antagonists: a structural and computational study.

M1 muscarinic acetylcholine receptor (M1-AChR), a member of the G protein-coupled receptors (GPCR) family, plays a crucial role in learning and memory, making it an important drug target for Alzheimer's disease (AD) and schizophrenia. M1-AChR activation and deactivation have shown modifying effects in AD and PD preclinical models, respectively. However, understanding the pharmacology associated with M1-AChR activation or deactivation is complex, because of the low selectivity among muscarinic subtypes, hampering their therapeutic applications. In this regard, we constructed two quantitative structure-activity relationship (QSAR) models, one for M1-AChR agonists (total and partial), and the other for the antagonists. The binding mode of 59 structurally different compounds, including agonists and antagonists with experimental binding affinity values (pKi), were analyzed employing computational molecular docking over different structures of M1-AChR. Furthermore, we considered the interaction energy (Einter), the number of rotatable bonds (NRB), and lipophilicity (ilogP) for the construction of the QSAR model for agonists (R2 = 89.64, QLMO2 = 78, and Qext2 = 79.1). For the QSAR model of antagonists (R2 = 88.44, QLMO2 = 82, and Qext2 = 78.1) we considered the Einter, the fraction of sp3 carbons fCsp3, and lipophilicity (MlogP). Our results suggest that the ligand volume is a determinant to establish its biological activity (agonist or antagonist), causing changes in binding energy, and determining the affinity for M1-AChR.

Perceived academic stress in Mexican medical students. The role of sex emotional distress, burnout, academic-social support, current abuse experiences, and coping strategies / Percepción del estrés académico en estudiantes de medicina mexicanos. El papel del sexo, distrés emocional, burnout, apoyo académico-social, experiencias actual es de abuso y estrategias de afrontamiento

Abstract Introduction Academic stress is a common problem among medical students that has a negative physiological, social, and learning impact. Perceived academic stress indicates how stressed a student is about academic issues over a given period of time and the ability to handle that stress. Objective To determine the prevalence of PAS and evaluate possible risk factors, focusing on sex differences, burnout, emotional distress, academic-social support, and coping strategies. Method A cross-sectional, retrospective, and comparative study was conducted through an online survey with medical students (MS) willing to participate anonymously. Results All students reported PAS and the majority to a moderate-severe degree. Comparing the presence of abuse within the academic environment between men and women, we found differences in the frequency of reporting emotional abuse and sexual. Also, we found differences in perceived academic social support from teachers and family members. Multiple logistic regression analysis showed sex and current sexual abuse inside school had the strongest association with PAS in MS, followed by a family history of depression and perceived less academic social support from family. Discussion and conclusion Timely identification of individuals at-risk will be critical to establish preventive strategies to limit the impact of PAS in MS, stress management programs, training coping skills, and offer prompt therapeutic alternatives when needed.

Resumen Introducción El estrés académico es un problema común entre los estudiantes de medicina que tiene un impacto negativo a nivel fisiológico, social y de aprendizaje. El estrés académico percibido (PAS) indica lo estresado que está un estudiante por cuestiones académicas durante un periodo de tiempo determinado y la capacidad para manejar ese estrés. Objetivo Determinar la prevalencia del PAS y evaluar los posibles factores de riesgo, centrándose en las diferencias por sexo, burnout, el malestar emocional, el apoyo académico-social y las estrategias de afrontamiento. Método Se realizó un estudio transversal, retrospectivo y comparativo a través de una encuesta en línea con estudiantes de medicina dispuestos a participar de forma anónima. Resultados Todos los estudiantes reportaron PAS y la mayoría en un grado moderado-severo. Comparando la presencia de maltrato dentro del ámbito académico entre hombres y mujeres, encontramos diferencias en la frecuencia de denuncia de maltrato emocional y sexual. Asimismo, encontramos diferencias en el apoyo social académico percibido por parte de docentes y familiares. El análisis de regresión logística múltiple mostró que el sexo y el abuso sexual actual dentro de la escuela tenían la asociación más fuerte con PAS, seguidos por antecedentes familiares de depresión y menos apoyo social académico percibido por parte de la familia. Discusión y conclusión La identificación oportuna de las personas en riesgo será fundamental para establecer estrategias preventivas para limitar el impacto de PAS, programas de manejo del estrés, capacitación en habilidades de afrontamiento y ofrecer alternativas terapéuticas rápidas cuando sea necesario.