Daño oxidativo pulmonar inducido por ejercicio aeróbico prolongado evaluado a través del análisis del aire espirado condensado

Se utilizó el análisis del aire espirado condensado (EBC) para evaluar el impacto de las carreras de resistencia sobre la formación de pro-oxidantes, lipidoperoxidación e inflamación pulmonar. Dieciocho, doce y diecisiete corredores aficionados sanos, de ambos sexos, participaron en pruebas de 10, 21 y 42 km respectivamente. Se obtuvieron muestras de EBC previo, a los 20 y 80 minutos posteriores a las carreras. Se determinó la concentración de H2O2, NO2 -, MDA y pH. Post-carrera los participantes de 21 y 42 km presentaron mayor concentración de H2O2 y NO2 – sin observarse variaciones en el grupo de 10 km. No se evidenciaron cambios en la concentración de MDA dentro los grupos de 10 y 42 km respectivamente, tampoco se observó diferencias al comparar los grupos referidos. El pH no mostró diferencias dentro de los grupos. El promedio de ΔH2O2 y ΔNO2 - en el grupo de 42 km fue mayor respecto del grupo 10 km. El promedio de los ΔpH disminuyó para 21 y 42km. Para el grupo de 10 km se observó un aumento de este parámetro, mostrando un promedio significativamente mayor que para 21 y 42 km. Los ΔH2O2 y ΔNO2 - correlacionaron en forma directa con el tiempo de carrera, mientras ΔpH, mostró una asociación inversa. Los valores de H2O2 y NO2 - correlacionaron entre sí de forma directa, mientras el pH mostró correlaciones inversas con los valores de H2O2 y NO2 - respectivamente. En conclusión, el ejercicio intenso prolongado favorece el aumento de los pro-oxidantes y favorece la inflamación pulmonar, sin modificaciones sobre la lipidoperoxidación. El tiempo de carrera se relaciona con la magnitud de la formación de pro-oxidantes y la inflamación aguda pulmonar post ejercicio.Exhaled breath condensate (EBC) was used to evaluate impact of endurance races on pro-oxidative formation, lipoperoxidation and pulmonary inflammation. Eighteen, twelve and seventeen healthy recreational runners, of both sexes, took part in 10, 21 and 42 km runs, respectively. EBC samples were collected before the run, at 20 and at 80 minutes after the run. Concentrations of H2O2, NO2 -, malondialdehyde (MDA) and pH were determined. After the run, participants of the 21 and 42 km circuits showed higher H2O2 and NO2 - concentrations while no variations were observed in the 10 km group. There were no observed changes in MDA concentration within the 10 and 42 km groups, and there were no differences when comparing them. pH showed no differences within these groups. ΔH2O2 y ΔNO2 - averages in the 42 km group were higher than in the 10 km group. ΔpH averages decreased for the 21 and 42 km groups. An increase in this parameter was observed in the 10 km group, showing a significantly higher average value than 21 and 42 km groups. ΔH2O2 y ΔNO2 - correlated directly with race time, while ΔpH, showed an inverse correlation. H2O2 y NO2 - values correlated directly between them, while pH showed inverse correlations with H2O2 y NO2 - values respectively. In conclusion, intense prolonged exercise favors the increase in pro-oxidative levels and pulmonary inflammation, with no modifications on lipoperoxidation. Running time also relates to the magnitude of pro-oxidative formation and acute post exercise pulmonary inflammation

Inflammation and oxidative stress as common mechanisms of pulmonary, autonomic, and musculoskeletal dysfunction after spinal cord injury

One of the etiopathogenic factors frequently associated with generalized organ damage after spinal cord injury corresponds to the imbalance of the redox state and inflammation, particularly of the respiratory, autonomic, and musculoskeletal systems. Our goal in this review was to gain a better understanding of this phenomenon by reviewing both animal and human studies. At the respiratory level, the presence of tissue damage is notable in situations that require increased ventilation due to lower thoracic distensibility and alveolar inflammation caused by higher levels of leptin as a result of increased fatty tissue. Increased airway reactivity, due to loss of sympathetic innervation, and levels of nitric oxide in exhaled air that are similar to those seen in asthmatic patients have also been reported. In addition, the loss of autonomic control efficiency leads to an uncontrolled release of catecholamines and glucocorticoids that induce immunosuppression, as well as a predisposition to autoimmune reactions. Simultaneously, blood pressure regulation is altered with vascular damage and atherogenesis associated with oxidative damage. At the muscular level, chronically elevated levels of prooxidants and lipoperoxidation associated with myofibrillar atrophy are described, with no reduction or reversibility of this process through antioxidant supplementatio

Comportamiento térmico en ríos mediterráneos andinos de la zona centro-sur de Chile

Despite of the importance of temperature in the fluvial ecosystems, the knowledge of its spatial and temporal variability in Andean rivers is limited, thus it is necessary to clarify the relative importance of site-specific factors in controlling the temperature of rivers. The aim of this research was to characterize the thermal regime of five Andean streams through an altitudinal gradient. The results show that there is a spatial and temporal variability in water temperature with a relatively rapid rise in temperature in mid-December, being stable in January and February, and a rapid decrease at the beginning of March and April. The thermal heterogeneity recorded in the high Andean zone of the Biobio River Basin makes it clear that geomorphology characteristics of each site are important in regulating water temperature, associated mainly with the altitude and shade; this latter mainly generated by high mountains and in some cases by the timberline. It is known that thermal variability, mainly the maximum and minimum mean temperatures; causing severe stress on stenotherm organisms. Therefore, a deeper knowledge of the river temperature is essential for the management and future protection of the Andean freshwater ecosystems to mitigate the impacts associated to the global warming.A pesar de la importancia que tiene la temperatura en los sistemas fluviales, el conocimiento de su variabilidad espacio-temporal en ríos de Chile es limitado. Tales estudios son necesarios para aclarar la importancia relativa de los factores locales a la hora de controlar la temperatura de los ríos. La presente investigación tuvo por objetivo caracterizar el régimen térmico de cinco ríos andinos de la región del Biobío a través de un gradiente altitudinal. Los resultados muestran que existe una variabilidad espacio-temporal en la temperatura del agua con un incremento relativamente rápido de la temperatura a mediados de diciembre, manteniéndose en enero y febrero, para disminuir rápidamente a principio de marzo y abril. La heterogeneidad térmica encontrada en la zona andina de la cuenca del río Biobío deja de manifiesto que las características geomorfológicas de cada sitio son relevantes en la regulación de la temperatura del agua, asociada principalmente a la altitud y sombra, esta última generada principalmente por las altas montañas y en algunos casos por la vegetación arbórea. Se prevé que cambios principalmente en las temperaturas medias máximas y mínimas podrían ocasionar un severo estrés en organismos estenotermos. Por lo tanto, un conocimiento detallado de la temperatura en ríos andinos podría proveer de información necesaria para direccionar la mitigación de los impactos asociados al calentamiento global

Effects of Exercise Training under Hyperbaric Oxygen on Oxidative Stress Markers and Endurance Performance in Young Soccer Players: A Pilot Study

The aim of the present study was to determine the effects of three weeks of hyperbaric oxygen (HBO2) training on oxidative stress markers and endurance performance in young soccer players. Participants (18.6±1.6 years) were randomized into hyperbaric-hyperoxic (HH) training (n=6) and normobaric normoxic (NN) training (n=6) groups. Immediately before and after the 5th, 10th, and 15th training sessions, plasma oxidative stress markers (lipid hydroperoxides and uric acid), plasma antioxidant capacity (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid [TROLOX]), arterial blood gases, acid-base balance, bases excess (BE), and blood lactate analyses were performed. Before and after intervention, maximal oxygen uptake (VO2max) and peak power output (PPO) were determined. Neither HH nor NN experienced significant changes on oxidative stress markers or antioxidant capacity during intervention. VO2max and PPO were improved (moderate effect size) after HH training. The results suggest that HBO2 endurance training does not increase oxidative stress markers and improves endurance performance in young soccer players. Our findings warrant future investigation to corroborate that HBO2 endurance training could be a potential training approach for highly competitive young soccer players

Moderate altitude but not additional endurance training increases markers of oxidative stress in exhaled breath condensate

Oxidative stress occurs at altitude, and physical exertion might enhance this stress. In the present study, we investigated the combined effects of exercise and moderate altitude on redox balance in ten endurance exercising biathletes, and five sedentary volunteers during a 6-week-stay at 2,800m. As a marker for oxidative stress, hydrogen peroxide (H2O2) was analyzed by the biosensor measuring system Ecocheck™, and 8-iso prostaglandin F2α (8-iso PGF2α) was determined by enzyme immunoassay in exhaled breath condensate (EBC). To determine the whole blood antioxidative capacity, we measured reduced glutathione (GSH) enzymatically using Ellman's reagent. Exercising athletes and sedentary volunteers showed increased levels of oxidative markers at moderate altitude, contrary to our expectations; there was no difference between both groups. Therefore, all subjects' data were pooled to examine the oxidative stress response exclusively due to altitude exposure. H2O2 levels increased at altitude and remained elevated for 3days after returning to sea level (p≤0.05). On the other hand, 8-iso PGF2α levels showed a tendency to increase at altitude, but declined immediately after returning to sea level (p≤0.001). Hypoxic exposure during the first day at altitude resulted in elevated GSH levels (p≤0.05), that decreased during prolonged sojourn at altitude (p≤0.001). In conclusion, a stay at moderate altitude for up to 6weeks increases markers of oxidative stress in EBC independent of additional endurance training. Notably, this oxidative stress is still detectable 3days upon return to sea leve

Base de datos de mediciones de respuestas impulsivas de recintos con diferentes características acústicas

La respuesta impulsiva de un recinto (RIR) engloba la característica de transmisión de lasondas sonoras entre una fuente y un receptor, asumiendo que el sistema es lineal e invariante en eltiempo. La respuesta impulsiva es diferente para cada ubicación de la dupla fuente-receptor y varíasegún la geometría y materiales, entre otros factores. En la actualidad el conocimiento de la RIRresulta imprescindible para el análisis y diseño de diversos recintos tales como salas de concierto,teatros, auditorios, salones de usos múltiples, ambientes industriales, oficinas, bibliotecas, ambientesespeciales (cámara anecóica y reverberante). La identificación de anomalías acústicas como ecosflotantes, resonancias, excesiva reverberación y otras, se realiza a través del análisis de la RIR. Lamedición de la RIR resulta útil también, para validar programas de simulación que se utilizan comoherramientas de diseño y sistemas de realidad acústica virtual. Actualmente existen varios métodos demedición de la RIR, siendo la ISO 3382 la norma de referencia que establece las directrices pararealizar dichas mediciones.En este trabajo se presentan los resultados de un conjunto de mediciones de RIR de espaciosarquitectónicos con diferentes características acústicas, efectuadas según norma ISO 3382. Elpropósito es difundir los resultados de dichas mediciones realizadas por el CINTRA con motivo deiniciar la construcción de una base de datos a nivel nacional e internacional que permita profundizarla investigación científica en temas referidos a la propagación de sonido en recintos, modos normalesde recintos, simulación acústica de recintos, realidad acústica virtual, diseño acústico arquitectónico,técnicas y métodos de medición en acústica de salas, entre otros.Fil: Cravero, Gabriel Agustín. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Transferencia en Acústica. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Transferencia en Acústica; ArgentinaFil: Ferreyra, Sebastian Pablo. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Transferencia en Acústica. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Transferencia en Acústica; ArgentinaFil: Ramos, Oscar Alberto. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Transferencia en Acústica. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Transferencia en Acústica; ArgentinaFil: Tommasini, Fabián Carlos. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Transferencia en Acústica. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Transferencia en Acústica; ArgentinaFil: Araneda, Mariano. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Transferencia en Acústica. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Transferencia en Acústica; Argentin

Sex-differences in the oxygenation levels of intercostales and vastus lateralis muscles during incremental exercise

This study aimed to examine sex differences in oxygen saturation in respiratory (SmO2-m.intercostales) and locomotor muscles (SmO2-m.vastus lateralis) while performing physical exercise. Twenty-five (12 women) healthy and physically active participants were evaluated during an incremental test with a cycle ergometer, while ventilatory variables (lung ventilation [V ̇E], tidal volume [Vt], and respiratory rate [RR]) were acquired through the breath-by-breath method. SmO2 was acquired using the MOXY devices on the m.intercostales and m.vastus lateralis. A two-way ANOVA (sex × time) indicated that women showed a greater significant decrease of SmO2-m.intercostales, and men showed a greater significant decrease of SmO2-m.vastus lateralis. Additionally, women reached a higher level of ΔSmO2-m.intercostales normalized to V ̇E (L·min-1) (p<0.001), whereas men had a higher level of ΔSmO2-m.vastus lateralis normalized to peak workload-to-weight (watts·kg-1, PtW) (p=0.049), as confirmed by Student's t-test. During an incremental physical exercise, women experienced a greater cost of breathing, reflected by greater deoxygenation of the respiratory muscles, whereas men had a higher peripheral load, indicated by greater deoxygenation of the locomotor muscles

Determination of the respiratory compensation point by detecting changes in intercostal muscles oxygenation by using near-infrared spectroscopy

This study aimed to evaluate if the changes in oxygen saturation levels at intercostal muscles (SmO2-m.intercostales) assessed by near-infrared spectroscopy (NIRS) using a wearable device could determine the respiratory compensation point (RCP) during exercise. Fifteen healthy competitive triathletes (8 male; 29±6 years; height 167.6±25.6 cm; weight 69.2±9.4 kg; V ̇O2-máx 58.4±8.1 mL·kg-1·min-1) were evaluated in a cycle ergometer during the maximal oxygen-uptake test (V ̇O2-máx), while lung ventilation (V ̇E), power output (watts, W) and SmO2-m.intercostales were measured. RCP was determined by visual method (RCPvisual: changes at ventilatory equivalents (V ̇E·V ̇CO2-1, V ̇E·V ̇O2-1) and end-tidal respiratory pressure (PetO2, PetCO2) and NIRS method (RCPNIRS: breakpoint of fall in SmO2-m.intercostales). During exercise, SmO2-m.intercostales decreased continuously showing a higher decrease when V ̇E increased abruptly. A good agreement between methods used to determine RCP was found (visual vs NIRS) at %V ̇O2-máx, V ̇O2, V ̇E, and W (Bland-Altman test). Correlations were found to each parameters analyzed (r=0.854; r=0.865; r=0.981; and r=0,968; respectively. p<0.001 in all variables, Pearson test), with no differences (p<0.001 in all variables, t-student test) between methods used (RCPvisual and RCPNIRS). We concluded that changes at SmO2-m.intercostales measured by NIRS could adequately determine RCP in triathletes

Oxygenation of respiratory and locomotor muscles during maximal exercise in two marathon runners

A high work of breathing (WOB) associated with pulmonary hyperventilation during physical exercise, may limit sports performance in long-distance runners (e.g. marathon). The assessment of changes in WOB during maximal oxygen consumption test (V̇O2-máx.) allows knowing the intensity of exercise at which the higher WOB limits the delivery of nutrients and oxygen in muscles involved during locomotion. The non-invasive assessment of muscle oxygenation (SmO2) by the interpretation of wavelengths of near-infrared range (Near-Infrared Spectroscopy, NIRS) is a useful and new method to quantify muscle work, used at intercostal muscles (SmO2-m. intercostales) to the WOB, and at locomotor muscles (SmO2-m.vastus laterallis) to external load. Thus, as the intensity of exercise increases, a higher decrease in SmO2 is showed. However, until now is unknown how the ventilatory strategy used to achieve pulmonary hyperventilation affects the SmO2 of these muscle groups, whose muscle work affects them reciprocally through the metabolic reflex. As a report-case, we present the changes in SmO2-m.intercostales (WOB) and peripheral (SmO2-m.vastus laterallis) during the V̇O2-máx. test. in two competitive marathon runners with similar anthropometric characteristics, physical performance, training regimen and sports history. The objective is to give new information for identifying that the ventilatory strategy used during exercise can affect the local oxygenation in muscles with high demand during exercise. To evaluate this aspect, helping to coach improving the exercise performance in their athletes

Horse Racing as a Model to Study the Relationship between Air Pollutants and Physical Performance

This study proposes the theoretical principles for the selection of a sample of horse races to study the relationship between air pollutants and performance. These criteria were then applied to an original dataset comparing the correlations between these variables obtained in &ldquo;Handicap&rdquo; versus &ldquo;Conditional&rdquo; type races. Methods: The mean concentration of pollutants during the six hours prior to the race and the speed of the test were determined in 441 official races at a racecourse in Santiago, Chile, during the summer and winter months of 2012. Using layout, track condition and distance (1000, 1100 and 1200 m) as criteria, a homogeneous group of races (&ldquo;Handicap&rdquo;; n = 214) versus a heterogeneous group (&ldquo;Conditional&rdquo;; n = 95) were compared using simple correlations (Spearman&rsquo;s test). Results: Race speed was related to greater levels of PM10, PM2.5, NO2, NO and SO2 and it was positively related to O3, a trend that was observed in the 1000, 1100 m races and in the total &ldquo;Handicap&rdquo; group. Similar results were observed only in 1000 m for the &ldquo;Conditional&rdquo; group with lower Rho, except for PM10 and PM2.5. The total races of the conditional group showed lower Rho values and significant associations of the same trend for CO, NO2, NO and SO2. Conclusions: Horse races between 1000 and 1200 m of the &ldquo;Handicap&rdquo; type appear to be an interesting group to study the relationship between air pollutants and the performance of racehorses. In the future, our observations should be expanded to other distances and other types of races