Oxidative Stress: Love and Hate History in Central Nervous System.

Molecular oxygen is essential for aerobic organisms in order to synthesize large amounts of energy during the process of oxidative phosphorylation and it is harnessed in the form of adenosine triphosphate, the chemical energy of the cell. Oxygen is toxic for anaerobic organisms but it is also less obvious that oxygen is poisonous to aerobic organisms at higher concentrations of oxygen. For instance, oxygen toxicity is a condition resulting from the harmful effects of breathing molecular oxygen at increased partial pressures. Reactive oxygen species (ROS) are chemically reactive molecules containing oxygen that are formed as a natural byproduct of the normal metabolism of oxygen and have important roles in cell signaling and homeostasis. However, in pathological conditions ROS levels can increase dramatically. This may result in significant damage to cell structures. Living organisms have been adapted to the ROS in two ways: they can mitigate the unwanted effects through removal by the antioxidant systems and can advantageously use them as messengers in cell signaling and regulation of body functions. Some other physiological functions of ROS include the regulation of vascular tone, detection, and adaptation to hypoxia. In this review, we describe the mechanisms of oxidative damage and its relationship with the most highly studied neurodegenerative diseases.

El polimorfismo (CAG)n del gen ATXN2, nuevo marcador de susceptibilidad para diabetes mellitus tipo 2 / (CAG)n polymorphism of the ATXN2 gene, a new marker of susceptibility for type 2 diabetes mellitus

Objetivo. Estimar si hay asociación del repetido (CAG)n del gen ATXN2 en población mexicana con diabetes mellitus (DM) tipo 2. Métodos. Estudio epidemiológico de casos y controles. Se incluyeron personas sanas y personas diabéticas. La detección de la expansión (CAG)n se realizó por reacción en cadena de la polimerasa (PCR)-punto final. Los productos de PCR se analizaron mediante electroforesis (PAGE al 8%) y tinción con nitrato de plata. Resultados. La distribución de alelos del trinucleótido (CAG)n en la población analizada resultó similar a la reportada en el centro del país. El alelo más frecuente es el de 22 repetidos; sin embargo, hay asociación con los portadores de los repetidos largos dentro del rango normal con diabetes. Conclusiones. Los resultados sugieren que el repetido (CAG)n del gen de ATXN2 podría ser un factor causal de DM tipo 2.

Objective. Estimate whether there is an association between the (CAG)n repeat in the ATXN2 gene in the Mexican population and type 2 diabetes mellitus (DM). Methods. Epidemiological case-control study, including healthy people and diabetics. (CAG)n expansion was detected by end-point polymerase chain reaction (PCR). PCR outputs were analyzed by electrophoresis (PAGE 8%) and silver nitrate staining. Results. (CAG)n nucleotide allele distribution in the study population was similar to that reported in central Mexico. The 22-repeat allele is the most frequent; however, there is an association with carriers of long repeats in the normal range with diabetes. Conclusions. The results sugge

El polimorfismo (CAG)n del gen ATXN2, nuevo marcador de susceptibilidad para diabetes mellitus tipo 2 / (CAG)n polymorphism of the ATXN2 gene, a new marker of susceptibility for type 2 diabetes mellitus

RESUMEN Objetivo Estimar si hay asociación del repetido (CAG)n del gen ATXN2 en población mexicana con diabetes mellitus (DM) tipo 2. Métodos Estudio epidemiológico de casos y controles. Se incluyeron personas sanas y personas diabéticas. La detección de la expansión (CAG)n se realizó por reacción en cadena de la polimerasa (PCR)-punto final. Los productos de PCR se analizaron mediante electroforesis (PAGE al 8%) y tinción con nitrato de plata. Resultados La distribución de alelos del trinucleótido (CAG)n en la población analizada resultó similar a la reportada en el centro del país. El alelo más frecuente es el de 22 repetidos; sin embargo, hay asociación con los portadores de los repetidos largos dentro del rango normal con diabetes. Conclusiones Los resultados sugieren que el repetido (CAG)n del gen de ATXN2 podría ser un factor causal de DM tipo 2.

ABSTRACT Objective Estimate whether there is an association between the (CAG)n repeat in the ATXN2 gene in the Mexican population and type 2 diabetes mellitus (DM). Methods Epidemiological case-control study, including healthy people and diabetics. (CAG)n expansion was detected by end-point polymerase chain reaction (PCR). PCR outputs were analyzed by electrophoresis (PAGE 8%) and silver nitrate staining. Results (CAG)n nucleotide allele distribution in the study population was similar to that reported in central Mexico. The 22-repeat allele is the most frequent; however, there is an association with carriers of long repeats in the normal range with diabetes. Conclusions The results suggest that the (CAG)n repeat of the ATXN2 gene could be a causal factor for type 2 DM.

[(CAG)n polymorphism of the ATXN2 gene, a new marker of susceptibility for type 2 diabetes mellitus]. / El polimorfismo (CAG)n del gen ATXN2, nuevo marcador de susceptibilidad para diabetes mellitus tipo 2.

OBJECTIVE: Estimate whether there is an association between the (CAG)n repeat in the ATXN2 gene in the Mexican population and type 2 diabetes mellitus (DM). METHODS: Epidemiological case-control study, including healthy people and diabetics. (CAG)n expansion was detected by end-point polymerase chain reaction (PCR). PCR outputs were analyzed by electrophoresis (PAGE 8%) and silver nitrate staining. RESULTS: (CAG)n nucleotide allele distribution in the study population was similar to that reported in central Mexico. The 22-repeat allele is the most frequent; however, there is an association with carriers of long repeats in the normal range with diabetes. CONCLUSIONS: The results suggest that the (CAG)n repeat of the ATXN2 gene could be a causal factor for type 2 DM.

Immunology and oxidative stress in multiple sclerosis: clinical and basic approach.

Multiple sclerosis (MS) exhibits many of the hallmarks of an inflammatory autoimmune disorder including breakdown of the blood-brain barrier (BBB), the recruitment of lymphocytes, microglia, and macrophages to lesion sites, the presence of multiple lesions, generally being more pronounced in the brain stem and spinal cord, the predominantly perivascular location of lesions, the temporal maturation of lesions from inflammation through demyelination, to gliosis and partial remyelination, and the presence of immunoglobulin in the central nervous system and cerebrospinal fluid. Lymphocytes activated in the periphery infiltrate the central nervous system to trigger a local immune response that ultimately damages myelin and axons. Pro-inflammatory cytokines amplify the inflammatory cascade by compromising the BBB, recruiting immune cells from the periphery, and activating resident microglia. inflammation-associated oxidative burst in activated microglia and macrophages plays an important role in the demyelination and free radical-mediated tissue injury in the pathogenesis of MS. The inflammatory environment in demyelinating lesions leads to the generation of oxygen- and nitrogen-free radicals as well as proinflammatory cytokines which contribute to the development and progression of the disease. Inflammation can lead to oxidative stress and vice versa. Thus, oxidative stress and inflammation are involved in a self-perpetuating cycle.

Envejecimiento y metabolismo: cambios y regulación

Los estudios sobre los efectos del envejecimiento en la fisiología y el metabolismo cada vez son más, uno de sus objetivos es contribuir a instrumentar programas para mejorar la calidad de vida y prevenir discapacidades en la vejez. Es de gran importancia mencionar que durante el envejecimiento se presenta una desaceleración natural del metabolismo, se produce una serie de cambios en la regulación de la energía, lo que contribuye a la pérdida de peso y grasa; estos cambios en la regulación de la ingesta calórica contribuyen en un aumento de la susceptibilidad al desequilibrio energético tanto positivo como negativo, lo cual va asociado a un deterioro en la salud. Sin embargo, el llegar a la vejez, no es una sentencia de muerte para el metabolismo, por el contrario, éste puede ser controlado mediante el mantenimiento de un estilo de vida activo, aunado a esto investigaciones han demostrado que el metabolismo puede ser regulado mediante el papel que desempeña un sistema de reloj sincronizado (ritmos biológicos), el cual a su vez es modulado por varias proteínas reguladoras; esta relación garantiza que las células funcionen correctamente y por tanto el mantenerse saludables. El objetivo de esta revisión es aportar información actualizada sobre la regulación metabolismo-energía y su relación con la gran variedad de componentes involucrados en el gasto energético que acompañan al envejecimiento; analizar la regulación de este sistema para mejorar la calidad de vida y mantener la salud en la vejez.

Aging and metabolism: changes and regulation. Studies about the effects of aging in the physiology and metabolism are increasingly, one of its objectives is to help implement programs to improve the quality of life and prevent disability in elderly. It is relevant to mention that, during aging, there is a natural metabolic deceleration, a series of changes in the regulation of energy are produced, which contributes to loss of weight and fat; the changes in the regulation of caloric intake contribute to increase the susceptibility to energy imbalance both positive and negative, which is associated with a deterioration in health. However, to grow old, is not a death sentence for metabolism, on the other hand, it can be controlled by maintaining an active lifestyle, coupled with this, research has shown that the metabolism can be regulated by a synchronized clock (circadian rhythms), which is mediated by regulatory proteins, this relationship ensures the proper functioning of the cells and therefore good health. The aim of this review is to provide updated information on the energy- metabolism-regulation and its relationship with the great variety of components involved in energy expenditure that accompany aging, to analyze the regulation of this system to improve the quality of life and maintenance of health in old age.

[Aging and metabolism: changes and regulation]. / Envejecimiento y metabolismo: cambios y regulación.

Studies about the effects of aging in the physiology and metabolism are increasingly, one of its objectives is to help implement programs to improve the quality of life and prevent disability in elderly. It is relevant to mention that, during aging, there is a natural metabolic deceleration, a series of changes in the regulation of energy are produced, which contributes to loss of weight and fat; the changes in the regulation of caloric intake contribute to increase the susceptibility to energy imbalance both positive and negative, which is associated with a deterioration in health. However, to grow old, is not a death sentence for metabolism, on the other hand, it can be controlled by maintaining an active lifestyle, coupled with this, research has shown that the metabolism'can be regulated by a synchronized clock (circadian rhythms), which is mediated by regulatory proteins, this relationship ensures the proper functioning of the cells and therefore good health. The aim of this review is to provide updated information on the energy- metabolism-regulation and its relationship with the great variety of components involved in energy expenditure that accompany aging, to analyze the regulation of this system to improve the quality of life and maintenance of health in old age.