Effects of resistance training on heat shock response (HSR), HSP70 expression, oxidative stress, inflammation, and metabolism in middle-aged people

Resistance training (RT) can increase the heat shock response (HSR) in the elderly. As middle-aged subjects already suffer physiological declines related to aging, it is hypothesized that RT may increase the HSR in these people. To assess the effects of resistance training on heat shock response, intra and extracellular HSP70, oxidative stress, inflammation, body composition, and metabolism in middle-aged subjects. Sixteen volunteers (40 – 59 years) were allocated to two groups: the trained group (n = 7), which performed 12 weeks of RT; and the physically inactive—control group (n = 9), which did not perform any type of exercise. The RT program consisted of 9 whole-body exercises (using standard gym equipment) and functional exercises, carried out 3 times/week. Before and after the intervention, body composition, muscle mass, strength, functional capacity, and blood sample measurements (lipid profile, glucose, insulin, oxidative damage, TNF-α, the HSR, HSP70 expression in leukocytes, and HSP72 in plasma) were performed. The HSR analysis demonstrated that this response is maintained at normal levels in middle-aged people and that RT did not cause any improvement. Also, RT increases muscle mass, strength, and functional capacity. Despite no additional changes of RT on the antioxidant defenses (catalase, glutathione peroxidase, and reductase) or inflammation, lipid peroxidation was diminished by RT (group x time interaction, p = 0.009), indicating that other antioxidant defenses may be improved after RT. HSR is preserved in middle-aged subjects without metabolic complications. In addition, RT reduces lipid peroxidation and can retard muscle mass and strength loss related to the aging process. (AU)

Effects of resistance training on heat shock response (HSR), HSP70 expression, oxidative stress, inflammation, and metabolism in middle-aged people

Resistance training (RT) can increase the heat shock response (HSR) in the elderly. As middle-aged subjects already suffer physiological declines related to aging, it is hypothesized that RT may increase the HSR in these people. To assess the effects of resistance training on heat shock response, intra and extracellular HSP70, oxidative stress, inflammation, body composition, and metabolism in middle-aged subjects. Sixteen volunteers (40 – 59 years) were allocated to two groups: the trained group (n = 7), which performed 12 weeks of RT; and the physically inactive—control group (n = 9), which did not perform any type of exercise. The RT program consisted of 9 whole-body exercises (using standard gym equipment) and functional exercises, carried out 3 times/week. Before and after the intervention, body composition, muscle mass, strength, functional capacity, and blood sample measurements (lipid profile, glucose, insulin, oxidative damage, TNF-α, the HSR, HSP70 expression in leukocytes, and HSP72 in plasma) were performed. The HSR analysis demonstrated that this response is maintained at normal levels in middle-aged people and that RT did not cause any improvement. Also, RT increases muscle mass, strength, and functional capacity. Despite no additional changes of RT on the antioxidant defenses (catalase, glutathione peroxidase, and reductase) or inflammation, lipid peroxidation was diminished by RT (group x time interaction, p = 0.009), indicating that other antioxidant defenses may be improved after RT. HSR is preserved in middle-aged subjects without metabolic complications. In addition, RT reduces lipid peroxidation and can retard muscle mass and strength loss related to the aging process. (AU)

A Kluyveromyces marxianus 2-deoxyglucoseresistant mutant with enhanced activity of xylose utilization

Thermotolerant ethanologenic yeast Kluyveromyces marxianus is capable of fermenting various sugars including xylose but glucose represses to hamper the utilization of other sugars. To acquire glucose repression-defective strains, 33 isolates as 2-deoxyglucose (2-DOG)-resistant mutants were acquired from about 100 colonies grown on plates containing 2-DOG, which were derived from an efficient strain DMKU 3-1042. According to the characteristics of sugar consumption abilities and cell growth and ethanol accumulation along with cultivation time, they were classified into three groups. The first group (3 isolates) utilized glucose and xylose in similar patterns along with cultivation to those of the parental strain, presumably due to reduction of the uptake of 2-DOG or enhancement of its export. The second group (29 isolates) showed greatly delayed utilization of glucose, presumably by reduction of the uptake or initial catabolism of glucose. The last group, only one isolate, showed enhanced utilization ability of xylose in the presence of glucose. Further analysis revealed that the isolate had a single nucleotide mutation to cause amino acid substitution (G270S) in RAG5 encoding hexokinase and exhibited very low activity of the enzyme. The possible mechanism of defectiveness of glucose repression in the mutant is discussed in this paper (AU)

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Pineal¨Cadrenal¨Cimmune system relationship under thermal stress: effect on physiological, endocrine, and non-specific immune response in goats

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The purpose of the investigation was to observe the pineal¨Cadrenal¨Cimmune system relationships and their influence on non-specific immune response in female goats under short-term thermal stress. Six female goats had been exposed to (..)(AU)

Golpe de calor en pacientes tratados con topiramato / Heatstroke during topiramate treatment

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¿Nos puede matar el verano? / Can summer kill us?

El golpe de calor es una emergencia médica y causa tratable de fracaso multiorgánico (FMO). Aparece cuando el organismo pierde el control de la temperatura corporal por fracaso del sistema termorregulador, lo que causa un ascenso de la temperatura central hasta 41°C o más. La falta de regulación calórica produce una alteración de la función celular con daño en los tejidos muscular, cerebral, vascular, hepático y renal, y puede producir complicaciones graves como rabdomiolisis. Es fundamental el diagnóstico precoz ya que, si no se toman las medidas iniciales oportunas, la tasa de mortalidad es muy alta. Hay dos formas habituales de presentación, una relacionada con el ejercicio en ambientes calurosos y otra forma clásica, durante intensas olas de calor. El tratamiento se basa en el enfriamiento inmediato junto con el soporte de órganos y sistemas

Heat stroke is a medical emergency and treatable cause of multiorgan failure (MOF). It appears when the body losses control of body temperature due to thermoregulatory system failure, which causes an increase in central temperature to 41° or more. Lack of calorie regulation produces an alteration of cell function with injury to muscular, cerebral, vascular, hepatic and renal tissues, and can cause serious complications such as rhabdomyolysis. Early diagnosis is fundamental. If the adequate initial steps are not taken, mortality rate is very high. There are two common presentation forms, one related with exercise in hot environments, and another classical ones, during intense heat waves. Treatment is based on immediate cooling together with organ and system support

Light-induced rhythmic changes in thermotolerance in stationary-phase cells of Candida utilis / Cambios rítmicos inducidos por la luz en la termotolerancia en la fase estacionaria de Candida utilis

In synchronized light-dark cycles, stationary-phase cultures of the budding yeast Candida utilis were able to survive heat treatment at 50ºC with an apparent circadian-like rhythm related to the onset of light. However, in continuous darkness this pattern did not run freely and was markedly dampened. We discuss these findings in terms of the potential circadian control of heat tolerance, which has been described in the fission yeast Schizosaccharomyces pombe. Our results suggest that the resistance pattern observed in C. utilis is most likely an adaptive response to the light-induced generation of reactive oxygen species rather than the occurrence of a truly endogenous circadian rhythm (AU)

La supervivencia de cultivos de Candida utilis en la fase estacionaria tras ser sometidos a temperaturas de 50ºC en ciclos sincronizados de luz/oscuridad presentó un aparente ritmo circadiano relacionado con el inicio de la fase iluminada. Sin embargo, en condiciones de oscuridad continua este patrón no se observaba tan claramente y mostraba una marcada ambigüedad. Estas observaciones se discuten en términos de un posible control circadiano de la tolerancia a altas temperaturas, que ha sido descrito para la levadura Schizosaccharomyces pombe. Nuestros resultados indican que el patrón de resistencia observado en C. utilis es muy probablemente una respuesta adaptativa a la generación de especies reactivas de oxígeno inducida por luz y que no existe un verdadero ritmo circadiano endógeno (AU)

Learning from yeasts: intracellular sensing of stress conditions / Aprendiendo de las levaduras: percepción intracelular de las condiciones de estrés

One intriguing challenge in modern biology is to understand how cells respond to, and distinguish between different stressing stimuli. Evidence accumulated in recent years indicates that a network of signaling pathways extends from the plasma membrane to the very core of the cell nucleus to transduce environmental changes into a graded transcriptional response. Although many steps still remain unclear, studies on the stress-activated protein kinase (SAPK) pathways and related mechanisms provide insight into the biochemistry that regulates signal transmission and leads to outcomes such as cell adaptation and differentiation. This review focuses on selected topics of current interest related to the sensing of stress signals in cells of the fission yeast Schizosaccharomyces pombe. Because signaling pathways appear to be evolutionarily well conserved, yeasts may be useful models to learn how higher eukaryotes sense and respond to stresses at the cellular level (AU)

Uno de los desafíos más intrigantes de la biología moderna es comprender cómo responden las células a diferentes estímulos estresantes y cómo los distinguen. Las pruebas acumuladas en los últimos años indican que una red de señales se extiende desde la membrana del citoplasma hasta el núcleo celular para transducir los cambios ambientales en una respuesta transcripcional satisfactoria. Aunque muchos pasos aún no están claros, estudios sobre la vía de la proteína quinasa activada por estrés (SAPK) y mecanismos afines proporcionan una nueva percepción de la bioquímica que regula la señal de transmisión y lleva a resultados tales como la adaptación y diferenciación celular. Esta revisión se centra en aspectos seleccionados de interés actual relativos a la percepción de señales de estrés en células de fisión de la levadura Schizosaccharomyces pombe. Debido a que las vías de señal parecen estar, desde un punto de vista evolutivo, bien conservadas, las levaduras podrían ser modelos útiles para aprender cómo perciben el estrés los eucariotas superiores y como responden al mismo a nivel celular (AU)