Resumen Introducción La pandemia de COVID-19 provocó el cese de las actividades académicas desde el formato presencial al confinamiento de las clases virtuales, de las que poco se ha estudiado sobre su efecto en la salud mental. Objetivo Determinar los niveles de depresión, ansiedad y estrés en estudiantes de medicina de México y Colombia durante la pandemia de COVID-19; además de comparar depresión, ansiedad y estrés por género, nivel educativo y país. Método Se realizó un estudio transversal con 426 estudiantes de medicina. Los datos se recopilaron mediante una encuesta en línea que contenía el cuestionario DASS-21. Resultados Las puntuaciones generales de depresión, ansiedad y estrés fueron 6.7 ± 1.2, 8.8 ± 1.2 y 5.6 ± 1.2, respectivamente. Las mujeres tuvieron puntajes generales significativamente más altos para depresión (.24-fold increase), ansiedad (.25-fold increase) y estrés (.40-fold increase). El riesgo de ansiedad y estrés por año escolar mostró que los años básicos se asociaron con puntajes más altos que los estudiantes en años los avanzados (.25 y .38-fold increase). Para las mujeres, cursar años básicos mostró un mayor riesgo de depresión en comparación con los estudiantes varones (.38-fold increase). Por último, los estudiantes mexicanos tuvieron un mayor riesgo de depresión y ansiedad (p ≤ .022 y p ≤ .004, respectivamente) pero no de estrés (p ≤ .402) en comparación con los estudiantes Colombianos. Discusión y conclusión Se observó ansiedad y depresión significativas en estudiantes de medicina mexicanos y colombianos. Los factores asociados a un mayor riesgo de depresión y ansiedad fueron; ser estudiante en años básicos además de ser mujer.

Abstract Introduction The COVID-19 pandemic caused the cessation of academic activities from the face-to-face format to confinement and virtual classes, in which little is studied about its effect on mental health. Objective Determine levels of depression, anxiety, and stress in medical students in Mexico and Colombia during the COVID-19 pandemic. Furthermore, depression, anxiety, and stress were compared by gender, education status, and country. Method A cross-sectional study was carried out with 426 medical students. Data was collected using an online survey containing the Depression, Anxiety, Stress Scale (DASS-21) questionnaire. Results Overall scores for depression, anxiety, and stress were 6.7 ± 1.2, 8.8 ± 1.2, and 5.6 ± 1.2, respectively. Females had significantly higher overall scores for depression (.24-fold increase), anxiety (.25-fold increase), and stress (.40-fold increase) than males (p ≤ .01). The risk for anxiety and stress by school year showed that basic years were associated with higher scores than advanced years (.25 and .38-fold increase, respectively). For females, starting medical school did show an increased risk of depression when compared to male students in their basic years (.38-fold increase). Lastly, students from Mexico had an increased risk for depression and anxiety (p ≤ .022 and p ≤ .004, respectively) but not for stress (p ≤ .402), when compared to students from Colombia. Discussion and conclusion Significant anxiety and depression were observed in medical students from Mexico and Colombia. Factors associated with an increased risk of depression and anxiety are students in their basic years as well as being female.

Abstract Introduction Our aim was to evaluate the dietary intake and anthropometric indices in medical students with positive family history of type 2 diabetes (FH-T2D)(+) and without FH-T2D(-). Material and Methods 144 students were analyzed in this cross-sectional, observational study, conducted during the 2017-2018 school year using interviews and 7-day food diary. The participants were characterized anthropometrically. Waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR), corrected mid-arm muscle area (MAMA), fat arm index (FAI), and tricipital skinfold (TSF) were calculated. Results We found that 79.2% (95%CI:72.5-85.8) had FH-T2D. BMI was significantly higher in the participants with FH-T2D than without (23.7±3.8 vs. 25.0±3.7, respectively; p<0.05). No significant differences were determined in the indices based on central fat distribution (WHtR and WHR), peripheral distribution (FAI and TSF), or muscle mass (MAMA), when stratified by FH-T2D. Regarding dietary intake, when comparing participants with and without FH-T2D, respectively, we observed low/none legume consumption [30% (95%CI:21.4-38.2) vs. 23% (95%CI:8.2-38.5)], diets high in proteins [38.6% (95%CI:29.7-47.5) vs. 46.7% (95%CI:28.8-64.5)], low in carbohydrates [84.2% (95%CI:77.5-90.9) vs. 83.3% (95%CI:70.0-96.7)], and insufficient energy intake [64% (95%CI:55.2-72.8) vs. 56.7% (95%CI:38.9-74.4)], where the alterations in the dietary pattern were more detrimental for the FH-T2D(+) group. Lastly, the participants with FH-T2D consumed mainly late in the day [60% (95%CI:50.6-68.6) vs. 54% (95%CI:35.5-71.2)]. Conclusions Even though there were minimal significant differences with the consumption by food categories, those students with FH-T2D presented with a poor, little varied and unbalanced dietary pattern with energy consumption mainly at night. These factors, if prolonged, could increase the risk of developing type 2 diabetes.

Resumen Introducción Nuestro objetivo fue evaluar la ingesta dietética y los índices antropométricos en estudiantes de medicina con historia familiar positiva de diabetes tipo 2 (FH-T2D)(+) y sin antecedentes familiares FH-T2D(-). Material y Métodos 144 estudiantes fueron analizados en este estudio transversal y observacional realizado durante el año escolar 2017-2018 mediante entrevistas y un diario de alimentos de 7 días. Los participantes se caracterizaron antropométricamente. Se calculó el ínidce cintura-cadera (WHR) y el índice cintura-altura (WHtR), el área muscular corregida de la mitad del brazo (MAMA), el índice de grasa del brazo (FAI) así como el pliegue cutáneo tricipital (TSF). Resultados El 79,2% (95%CI:72,5-85,8) tenían FH-T2D. El IMC fue significativamente mayor en los participantes con FH-T2D que en aquellos sin FH-T2D (23,7±3,8 vs. 25,0±3,7, respectivamente; p<0,05). No se determinaron diferencias significativas en los índices basados en la distribución de grasa central (WHtR y WHR), la distribución periférica (FAI y TSF) o la masa muscular (MAMA), cuando se estratificó por FH-T2D. Al comparar la ingesta dietética de participantes con y sin FH-T2D, respectivamente, observamos un consumo bajo/ninguno de leguminosas [30% (95%CI:21,4-38,2) frente a 23% (95%CI:8,2-38,5)], dietas altas en proteínas [38,6% (95%CI:29,7-47,5) frente a 46,7% (95%CI:28,8-64,5)], bajas en carbohidratos [84,2% (95%CI:77,5-90,9) frente a 83,3% (95%CI:70,0-96,7)], y la ingesta de energía insuficiente [64% (95%CI:55,2-72,8) frente a 56,7% (95%CI:38,9-74,4)], donde las alteraciones en el patrón de la dieta fueron más perjudiciales para el grupo FH-T2D(+). Los participantes con FH-T2D consumieron al final del día [60% (95%CI:50,6-68,6) frente a 54% (95%CI:35,5-71,2)]. Conclusiones Aunque hubo diferencias mínimas significativas con el consumo por categorías de alimentos, aquellos estudiantes con FH-T2D presentaron un patrón dietético deficiente, poco variado y desequilibrado con un consumo de energía principalmente por la noche. Estos factores, si se prolongan, podrían aumentar el riesgo de desarrollar diabetes tipo 2.

Abstract Our objective was to determine the association between the methylenetetrahydrofolate reductase polymorphisms (C677T and A1298C) and the risk of developing acute lymphoblastic leukemia (ALL), chronic myeloid leukemia (CML), acute myeloid leukemia (AML), and multiple myelomas (MM) in Latinos. PubMed, SCOPUS, EBSCO, LILACS, and other Latin-specific databases were searched for case-control studies that investigated the association between these polymorphisms and hematologic malignancies until November 2017. Genotype distributions were extracted and either fixed-effects or random-effects models were used to calculate the pooled crude odds ratios (ORs) for the heterozygous, homozygous, dominant, recessive, and allelic genetic models. No publication bias was detected by the Begg-Mazumdar’s test and Egger’s test. From 290 publications, we identified 15 studies on the C677T polymorphism and 13 studies on the A1298C polymorphism. We observed a significant decrease in risk for the C677T polymorphism (OR range=0.54-0.75, p<0.01) and a significant increase in risk for the A1298C polymorphism (OR range=1.28-2.52, p<0.05) in developing ALL for all genetic models. No associations were determined for CML, AML, or MM for either polymorphism. This meta-analysis demonstrated that the A1298C polymorphism was associated with an increased risk of developing ALL, whereas the C677T polymorphism was associated with a decreased risk (protective factor) in the Latino population.

RESUMO Objetivo Determinar a confiabilidade de um instrumento de coleta de dados não laboratoriais, Encuesta de Identificación de Sujetos Metabólicamente Comprometidos en Fase-I (pesquisa de identificação de indivíduos com comprometimento metabólico em fase I, ESF-I) para identificar síndrome metabólica em uma população da região central do México. Métodos Foram coletados parâmetros clínicos e bioquímicos de 232 participantes da pesquisa entre 1° de junho de 2012 e 31 de agosto de 2013. O estudo se baseou em três definições de síndrome metabólica (definição harmonizada do Painel de Especialistas do Programa Nacional de Educação em Colesterol dos Estados Unidos [NCEP]; Painel para Tratamento de Adultos III [ATPIII]; e Federação Internacional de Diabetes [FIL]) para alocar os participantes em um grupo normal ou em um grupo com síndrome metabólica (SM). A previsibilidade do instrumento foi determinada pela área sob a curva ROC (característica de operação do receptor) (AUC). O índice de Youden foi calculado e o escore mais alto foi considerado o valor ideal de corte. O coeficiente kappa de Cohen (κ) foi calculado para determinar o grau de concordância entre o questionário ESF-1 (pontuação máxima de 15 em 15 itens) e a síndrome metabólica. Resultados Foi determinado que 53,8% a 60,7% dos participantes apresentavam SM. A pontuação média no instrumento foi significativamente maior no grupo SM com cada uma das definições usadas (4,0 vs. 8,0, P<0,05). O questionário ESF-I foi preditivo com a definição harmonizada (AUC 0,841; IC 95% 0,790–0,892), com a definição do ATPIII (AUC 0,827; IC 95% 0,774–0,880) e com a definição da FIL (AUC 0,836; IC 95% 0,785–0,887). Um valor de corte de 7 foi determinado para cada definição e a coorte foi recategorizada de acordo com os resultados do instrumento. Foi observada uma forte concordância entre o questionário ESF-I e o grupo SM (harmonizada: precisão = 77,6%, κ = 0,554; ATPIII: precisão = 74,1%, κ = 0,489; FIL: precisão = 74,6%, κ = 0,495, P<0,001). Conclusão O questionário ESF-I é capaz de identificar pacientes com síndrome metabólica, possibilitando o diagnóstico precoce, um número menor de consultas e um custo menor com uma aplicação mais simples.

ABSTRACT Objective To determine the reliability of a non-laboratorial questionnaire, the Encuesta de Identificación de Sujetos Metabólicamente Comprometidos en Fase-I (ESF-I) for identifying Metabolic Syndrome among a population in central Mexico. Methods Clinical and biochemical parameters were collected for 232 participants from 1 June 2012 – 31 August 2013. Three definitions of Metabolic Syndrome (Harmonizing, National Cholesterol Education Program Expert Panel and Adult Treatment Panel III [ATPIII], and International Diabetes Federation [IDF]) were used to allocate subjects to either the normal or Metabolic Syndrome positive (MetS+) group. The predictability of the questionnaire was determined by the Area-Under-the-Receiver-Operating Characteristic curve (AUC). Youden's index was calculated and the highest score was considered the optimal cutoff value. Cohen´s kappa (κ) was calculated to determine the level of agreement between the ESF-I questionnaire (max score: 15 based on 15 items) and Metabolic Syndrome. Results From 53.8% – 60.7% of the participants were determined to be MetS+. The average questionnaire score was significantly higher in the MetS+ group for each definition (4.0 vs. 8.0, P < 0.05). The ESF-I questionnaire was predictive for the Harmonizing definition (AUC = 0.841, 95%CI: 0.790 – 0.892), the ATPIII definition (AUC = 0.827, 95%CI: 0.774 – 0.880), and the IDF definition (AUC = 0.836, 95%CI: 0.785 – 0.887). A cutoff value of 7 was determined for each definition; therefore, the cohort was re-categorized based on questionnaire results. There was a strong agreement between the ESF-I questionnaire and MetS (Harmonizing: accuracy = 77.6%, κ = 0.554; ATPIII: accuracy = 74.1%, κ = 0.489; IDF: accuracy = 74.6%, κ = 0.495, P < 0.001). Conclusion The ESF-I questionnaire can identify MetS+ patients, and therefore, lead to earlier diagnoses, reduced number of consultations, and lower costs with easier application.

RESUMEN Objetivo Determinar la fiabilidad de un cuestionario en el que no se recurre al diagnóstico de laboratorio, la Encuesta de Identificación de Sujetos Metabólicamente Comprometidos en Fase-I (ESF-I), para detectar el síndrome metabólico en una población de la región central de México. Métodos Se recogieron parámetros clínicos y bioquímicos de 232 participantes desde el 1 de junio del 2012 al 31 de agosto del 2013. Se usaron tres definiciones de síndrome metabólico (la unificadora, la del Grupo de Expertos en el Tratamiento de Adultos [ATPIII] del Programa Nacional de Educación sobre el Colesterol y la de la Federación Internacional de la Diabetes [FID]) para asignar los participantes al grupo normal o al grupo de síndrome metabólico positivo (SMet+). Se determinó la previsibilidad del cuestionario con el área bajo la curva de eficacia diagnóstica (curva ROC). Se calculó el índice de Youden y la puntuación más alta se consideró el valor de corte óptimo. El coeficiente (k) de Cohen se calculó para determinar el grade de acuerdo entre el cuestionario ESF-I (máxima puntuación: 15 sobre 15 ítems) y el síndrome metabólico. Resultados Del 53,8 % al 60,7 % de los participantes se asignaron al grupo SMet+. La puntuación promedio del cuestionario fue significativamente mayor en el grupo de SMet+ para cada definición (4,0 vs. 8.0, P < 0.05). El cuestionario ESF-I fue predictivo para la definición unificadora (AUC = 0,841, 95 % CI: 0,790 – 0,892), la definición ATPIII (AUC = 0,827, 95 % CI: 0,774 – 0,880) y la definición de la FID (AUC = 0,836, 95 % CI: 0,785 – 0,887). Se determinó un el valor de corte óptimo de 7 para cada definición; por lo tanto, se reclasificó la cohorte según los resultados del cuestionario. Hubo una gran coincidencia entre el cuestionario ESF-I y SMet (unificadora: exactitud = 77,6 %, κ = 0,554; ATPIII: exactitud = 74,1 %, κ = 0,489; FID: exactitud = 74,6%, κ = 0,495, P < 0,001). Conclusiones El cuestionario ESF-I puede detectar pacientes con SMet+ y, por lo tanto, conducir a diagnósticos más tempranos, reducir la cantidad de consultas y reducir los costos con una aplicación más fácil.

Chagas disease, caused by Trypanosoma cruzi, represents an endemic among Latin America countries. The participation of free radicals, especially nitric oxide (NO), has been demonstrated in the pathophysiology of seropositive individuals with T. cruzi. In Chagas disease, increased NO contributes to the development of cardiomyopathy and megacolon. Metallothioneins (MTs) are efficient free radicals scavengers of NO in vitro and in vivo. Here, we developed a murine model of the chronic phase of Chagas disease using endemic T. cruzi RyCH1 in BALB/c mice, which were divided into four groups: infected non-treated (Inf), infected N-monomethyl-L-arginine treated (Inf L-NAME), non-infected L-NAME treated and non-infected vehicle-treated. We determined blood parasitaemia and NO levels, the extent of parasite nests in tissues and liver MT-I expression levels. It was observed that NO levels were increasing in Inf mice in a time-dependent manner. Inf L-NAME mice had fewer T. cruzi nests in cardiac and skeletal muscle with decreased blood NO levels at day 135 post infection. This affect was negatively correlated with an increase of MT-I expression (r = -0.8462, p < 0.0001). In conclusion, we determined that in Chagas disease, an unknown inhibitory mechanism reduces MT-I expression, allowing augmented NO levels.

In Mexico, despite the relatively high seroprevalence of Trypanosoma cruzi infection in humans in some areas, reported morbidity of Chagas disease is not clear. We determined clinical stage in 71 individuals seropositive to T. cruzi in the state of Puebla, Mexico, an area endemic for Chagas disease with a reported seroprevalence of 7.7%. Diagnosis of Chagas disease was made by two standardized serological tests (ELISA, IHA). Individuals were stratified according to clinical studies. All patients were submitted to EKG, barium swallow, and barium enema. Groups were identified as indeterminate form (IF) asymptomatic individuals without evidence of abnormalities (n = 34 cases); those with gastrointestinal alterations (12 patients) including symptoms of abnormal relaxation of the lower esophageal sphincter and absent peristalsis in the esophageal body, grade I megaesophagus, and/or megacolon; patients with clinical manifestations and documented changes of chronic Chagas heart disease who were subdivided as follows: mild (8 patients) - mild electrocardiographic changes of ventricular repolarization, sinus bradychardia); moderate (6 patients) - left bundle branch block, right bundle branch block associated with left anterior fascicular block); severe (8 patients) - signs of cardiomegaly, dilated cardiomyopathy); and the associated form (3 cases) that included presence of both cardiomyopathy and megaesophagus. These data highlight the importance of accurate evaluation of the prevalence and clinical course of Chagas disease in endemic and non-endemic areas of Mexico.

In this study, three strains of Trypanosoma cruzi were isolated at the same time and in the same endemic region in Mexico from a human patient with chronic chagasic cardiomyopathy (RyC-H); vector (Triatoma barberi) (RyC-V); and rodent reservoir (Peromyscus peromyscus) (RyC-R). The three strains were characterized by multilocus enzyme electrophoresis, random amplified polymorphic DNA, and by pathological profiles in experimental animals (biodemes). Based on the analysis of genetic markers the three parasite strains were typed as belonging to T. cruzi I major group, discrete typing unit 1. The pathological profile of RyC-H and RyC-V strains indicated medium virulence and low mortality and, accordingly, the strains should be considered as belonging to biodeme Type III. On the other hand, the parasites from RyC-R strain induced more severe inflammatory processes and high mortality (> 40%) and were considered as belonging to biodeme Type II. The relationship between genotypes and biological characteristics in T. cruzi strains is still debated and not clearly understood. An expert committee recommended in 1999 that Biodeme Type III would correspond to T. cruzi I group, whereas Biodeme Type II, to T. cruzi II group. Our findings suggest that, at least for Mexican isolates, this correlation does not stand and that biological characteristics such as pathogenicity and virulence could be determined by factors different from those identified in the genotypic characterization