RESUMEN
One principal purpose of assisted reproductive technology (ART) is to produce viable and good quality embryos. However, a variety of environmental factors may induce epigenetic changes in the embryo. Moreover, laboratory conditions including the culture media may also affect embryo development. Therefore, media change is an important factor in maintaining proper oxidant/antioxidant balance during embryo culture. Alterations in the oxidant/antioxidant balance are related to various cellular responses such as an increase in the level of reactive oxygen species (ROS) and consequent lipid peroxidation (LPO), DNA damage, and apoptosis. The current study focuses on the role of external factors on embryo culture and the ability of antioxidants to enhance in vitro fertilization (IVF) outcomes. Indeed, an optimization of media culture by the addition of enzymatic and nonenzymatic antioxidants in animal models and human embryos in ART has been updated in this study, with an emphasis on comparing the available results and their possible reasons.
Asunto(s)
Antioxidantes , Oxidantes , Humanos , Embrión de MamíferosRESUMEN
Se discute el papel del Aedes aegypti (Lineo) en la epidemiología del dengue en México usando como referencia el modelo de la capacidad vectorial. Se presentan comentarios sobre las ventajas y desventajas de cada uno de los componentes de este modelo al momento de su determinación en campo. Se enfatiza cómo la suma de errores metodológicos y de muestreo, afecta finalmente el resultado de la capacidad vectorial. Se subraya la necesidad de incrementar el conocimiento en la biología del Aedes aegypti, como una respuesta a las necesidades de la epidemiología en su tarea de predecir y explicar brotes de dengue, y se comenta sobre variables potenciales de importancia epidemiológica de origen entomológico que del modelo cuantitativo no considera. Finalmente, se menciona la introducción del Aedes albopictus (Skuse) en México y cómo esto viene a complicar más la comprensión de la transmisión del dengue
The role of Aedes aegypti (Lineo) in the epidemiology of dengue fever in Mexico is herein discussed based on the vectorial capacity model. Comments on the advantages and disadvantages of each model component at the time of field determinations are also presented. Emphasis is made on the impact of sampling and method bias on the results of vectorial capacity studies. The paper also addresses the need to increase vector biology knowledge as an input for epidemiological work to explain and predict dengue fever outbreaks. Comments on potential entomological variables not considered by the quantitative model are included. Finally, we elaborate on the introduction of Aedes albopictus (Skuse) in Mexico as a new risk factor and on its implications for the understanding of dengue fever transmission in Mexico.