Over the last decades, the use of phylogenetic methods in the study of emerging infectious diseases has gained considerable traction in public health. Particularly, the integration of phylogenetic analyses with the understanding of the pathogen dynamics at the population level has provided powerful tools for epidemiological surveillance systems. In the same way, the development of statistical methods and theory, as well as improvement of computational efficiency for evolutionary analysis, has expanded the use of these tools for vaccine and antiviral development. Today with the Coronavirus Disease 2019 (COVID-19), this seems to be critical. In this article, we discuss how the application of phylodynamic analysis can improve the understanding of current pandemic dynamics as well as the design, selection, and evaluation of vaccine candidates and antivirals.
Background: A large number of chemical compounds exert their antioxidant effects by activation of key transcriptional regulatory mechanisms, such as the transcription factor Nrf2. The aim of this study was to evaluate the activation of the Keap1-Nrf2 pathway by both the n-butanol extract obtained from the inner bark of Tabebuia rosea (Bertol) DC and specioside isolated from this extract. Methods: The antioxidant activity of the extract and specioside isolated from the inner bark of T. rosea were evaluated using the oxygen radical absorbance capacity (ORAC) and the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH) techniques, whereas their effects on the viability of HepG2 cells was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The effects of the compound and the extract on activating the Keap1-Nrf2 pathway were evaluated using a Nrf2 Transcription Factor Assay kit. Induction of the Nrf2-mediated antioxidant response genes HMOX-1 and NQO1 was evaluated by real-time PCR. The protective effects against H2O2-induced oxidative stress in HepG2 cells was determined as the percent protection using the MTT method. Results: Both the n-butanol extract and specioside exhibited activity at low concentrations without affecting cellular viability, since the cell viability was greater than 80% after 24 hours of exposure at each tested concentration. In addition, Nrf2 dissociated from Keap1 after treatment with the n-butanol extract at a concentration of 0.25 µg/mL after 4 hours of exposure. An increase in the Nrf2 level in the cytoplasm after 4 hours of exposure to 2 μM specioside was observed. Nrf2 levels stabilized in the nucleus 12 hours after stimulation with both specioside and the extract. After 6 hours of stimulation, both the extract and specioside induced the expression of HMOX-1 and NQO1. Conclusion: The n-butanol extract from the inner bark of T. rosea and specioside produced protective effects against H2O2-induced oxidative stress in HepG2 cells.
Background: A large number of chemical compounds exert their antioxidant effects by activation of key transcriptional regulatory mechanisms, such as the transcription factor Nrf2. The aim of this study was to evaluate the activation of the Keap1-Nrf2 pathway by both the n-butanol extract obtained from the inner bark of Tabebuia rosea (Bertol) DC and specioside isolated from this extract. Methods: The antioxidant activity of the extract and specioside isolated from the inner bark of T. rosea were evaluated using the oxygen radical absorbance capacity (ORAC) and the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH) techniques, whereas their effects on the viability of HepG2 cells was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The effects of the compound and the extract on activating the Keap1-Nrf2 pathway were evaluated using a Nrf2 Transcription Factor Assay kit. Induction of the Nrf2-mediated antioxidant response genes HMOX-1 and NQO1 was evaluated by real-time PCR. The protective effects against H2O2-induced oxidative stress in HepG2 cells was determined as the percent protection using the MTT method. Results: Both the n-butanol extract and specioside exhibited activity at low concentrations without affecting cellular viability, since the cell viability was greater than 80% after 24 hours of exposure at each tested concentration. In addition, Nrf2 dissociated from Keap1 after treatment with the n-butanol extract at a concentration of 0.25 µg/mL after 4 hours of exposure. An increase in the Nrf2 level in the cytoplasm after 4 hours of exposure to 2 μM specioside was observed. Nrf2 levels stabilized in the nucleus 12 hours after stimulation with both specioside and the extract. After 6 hours of stimulation, both the extract and specioside induced the expression of HMOX-1 and NQO1. Conclusion: The n-butanol extract from the inner bark of T. rosea and specioside produced protective effects against H2O2-induced oxidative stress in HepG2 cells.
Introducción: Las parasitosis intestinales y la anemia son un problema de salud pública mundial. Estos parásitos tienen tropismo hacia el intestino delgado, afectan la absorción de micronutrientes durante la eritropoyesis, produciendo la aparición de un síndrome anémico por un recuento bajo de glóbulos rojos y déficit de hemoglobina. Objetivo: Establecer la asociación de la infección por parásitos intestinales y síndrome anémico en niños en edad escolar. Materiales y métodos: Búsqueda sistemática de literatura publicada entre 2010-2021 sobre asociación entre infección por parásitos intestinales y síndrome anémico en escolares. Resultados: Se identificó 1151 publicaciones, al aplicar los criterios de inclusión y exclusión, se redujeron a 33, encontrándose 9 agentes asociados a anemia, siendo A. lumbricoides (27,27%), A. duodenalis y T. trichiura los helmintos más prevalentes, y G. duodenalis (6,06%) el protozoario más común. El 39,39% de los estudios incluyó ambos agentes. África (21), Asia (6), Sudamérica (5) y Centroamérica (1) tienen la mayoría de publicaciones. Se observa asociación significativa entre infección parasitaria y la anemia IC=95%. Conclusión: La evidencia demuestra alta prevalencia de anemias carenciales de tipo ferropénica y megaloblástica, con asociación significativa entre un mayor porcentaje de infecciones por helmintos y síndrome anémico, en comparación con infecciones por protozoos.
Background: SARS-CoV-2 revealed important gaps in infectious disease surveillance. Molecular epidemiology can help monitoring and adapting traditional surveillance to surpass those limitations. This work aims to contrast data driven from traditional surveillance with parameters inferred from molecular epidemiology in Latin America (LATAM) Methods: We obtained epidemiological data up to 4 th June, 2020. We estimated Effective Reproductive Number (Re) and epidemic curves using maximum likelihood (ML). SARS-CoV-2 genomes were obtained from GISAID up to June 4 th 2020. We aligned sequences, generated a ML phylogenetic tree, and ran a coalescent model Birth Death SIR. Phylodynamic analysis was performed for inferring Re, number of infections and date of introduction. Findings: A total of 1,144,077 cases were reported up to 4 th June 2020. Countries with the largest cumulative cases were Chile, Peru and Panama. We found at least 18 different lineages circulating, with a predominance of B.1 and B.1.1. We inferred an underestimation of the daily incident cases. When contrasting observed and inferred Re, we did not find statistically significant differences except for Chile and Mexico. Temporal analysis of the introduction of SARS-CoV-2 suggested a detection lag of at least 21 days. Interpretation: Our results support that epidemiological and genomic surveillance are two complementary approaches. Even with a low number of genomes proper estimations of Re could be performed. We suggest that countries, especially developing countries, should consider to add genomic surveillance to their systems for monitoring and adapting epidemiological control of SARS-CoV-2.