964 resultados para VO(2)PEAK
Resumo:
Maintaining an adequate tissue oxygen delivery (DO(2)) and consumption (VO(2)) is crucial in the treatment of septic patients. A fall in V0(2) is associated with a higher mortality. The early recognition of shock or tissue hypo perfusion impacts on patient prognosis. In occasions, hypovolemia or important regional oxygen debts are not recognized, since macro homodynamic variables have been compensated. In this situation, the use of metabolic hypo perfusion markers such as lactate, central venous oxygen saturation and gastric goniometry, can be helpful. However, interpretation of these markers should be cautious and always considering the overall clinical status of the patient. In the initial stages of sepsis, the dependency of V0(2) on DO(2) predominates as histopathological mechanism of multiple organic failure. In late stages, other factors predominate as determinants of multiple organic failure and mortality, such as hyper or hypo immune response, microcirculatory alterations and cytopathic hypoxia.
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The contribution of neuronal nitric oxide synthase (nNOS) to angiogenesis in human skeletal muscle after endurance exercise is controversially discussed. We therefore ascertained whether the expression of nNOS is associated with the capillary density in biopsies of the vastus lateralis (VL) muscle that had been derived from 10 sedentary male subjects before and after moderate training (four 30-min weekly jogging sessions for 6 months, with a heart-rate corresponding to 75% VO(2)max). In these biopsies, nNOS was predominantly expressed as alpha-isoform with exon-mu and to a lesser extent without exon-mu, as determined by RT-PCR. The mRNA levels of nNOS were quantified by real-time PCR and related to the capillary-to-fibre ratio and the numerical density of capillaries specified by light microscopy. If the VL biopsies of all subjects were co-analysed, mRNA levels of nNOS were non-significantly elevated after training (+34%; P > 0.05). However, only five of the ten subjects exhibited significant (P ≤ 0.05) elevations in the capillary-to-fibre ratio (+25%) and the numerical density of capillaries (+21%) and were thus undergoing angiogenesis. If the VL biopsies of these five subjects alone were evaluated, the mRNA levels of nNOS were significantly up-regulated (+128%; P ≤ 0.05) and correlated positively (r = 0.8; P ≤ 0.01) to angiogenesis. Accordingly, nNOS protein expression in VL biopsies quantified by immunoblotting was significantly increased (+82%; P ≤ 0.05) only in those subjects that underwent angiogenesis. In conclusion, the expression of nNOS at mRNA and protein levels was statistically linked to capillarity after exercise suggesting that nNOS is involved in the angiogenic response to training in human skeletal muscle.
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Recently, a new oxygenator (Dideco 903 [D903], Dideco, Mirandola, Italy) has been introduced to the perfusion community, and we set about testing its oxygen transfer performance and then comparing it to two other models. This evaluation was based on the comparison between oxygen transfer slope, gas phase arterial oxygen gradients, degree of blood shunting, maximum oxygen transfer, and diffusing capacity calculated for each membrane. Sixty patients were randomized into three groups of oxygenators (Dideco 703 [D703], Dideco; D903; and Quadrox, Jostra Medizintechnik AG, Hirrlingen, Germany) including 40/20 M/F of 68.6 +/- 11.3 years old, with a body weight of 71.5 +/- 12.1 kg, a body surface area (BSA) of 1.84 +/- 0.3 m(2), and a theoretical blood flow rate (index 2.4 times BSA) of 4.4 +/- 0.7 L/min. The maximum oxygen transfer (VO(2)) values were 313 mL O(2)/min (D703), 579 mL O(2)/min (D903), and 400 mL O(2)/min (Quadrox), with the D903 being the most superior (P < 0.05). Oxygen (O(2)) gradients were 320 mm Hg (D703), 235 mm Hg (D903), and 247 mm Hg (Quadrox), meaning D903 and Quadrox are more efficient versus the D703 (P < 0.05). Shunt fraction (Qs/Qt) and diffusing capacity (DmO(2)) were comparable (P = ns). Diffusing capacity values indexed to BSA (DmO(2)/m(2)) were 0.15 mL O(2)/min/mm Hg/m(2) (D703), 0.2 mL O(2)/min/mm Hg/m(2) (D903), and 0.18 mL O(2)/min/mm Hg/m(2) (Quadrox) with D903 outperforming D703 (P < 0.0005). During hypothermia (32.0 +/- 0.3 degrees C), there was a lower absolute and relative VO(2 )for all three oxygenators (P = ns). The O(2) gradients, DmO(2) and DmO(2)/m(2), were significantly lower for all oxygenators (P < 0.01). Also, Qs/Qt significantly rose for all oxygenators (P < 0.01). The oxygen transfer curve is characteristic to each oxygenator type and represents a tool to quantify oxygenator performance. Using this parameter, we demonstrated significant differences among commercially available oxygenators. However, all three oxygenators are considered to meet the oxygen needs of the patients.
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PURPOSE: Gender-specific differences in substrate utilization during exercise have been reported, typically such that women rely more on fat than men. This study investigated whether gender differences exist in the utilization of intramyocellular lipids (IMCL) and glycogen. METHODS: IMCL and glycogen, as well as total fat and carbohydrate (CHO) oxidation were measured in nine males and nine females before, during, and after an endurance exercise. The trained subjects exercised on a bicycle ergometer at 50% maximal workload for 3 h. IMCL and glycogen were determined in the thigh by magnetic resonance spectroscopy. Oxygen uptake (VO(2)) and carbon dioxide production were determined by open circuit spirometry to calculate total fat and CHO oxidation. Relative power output, percent of maximum heart rate, VO(2peak), and respiratory exchange ratio were the same. RESULTS: Average fat oxidation was the same, whereas CHO oxidation was significantly higher in males compared with females. The relative contribution of these fuels to total energy used were similar in males and females. Males and females depleted IMCL and glycogen significantly (P < 0.001) during the 3-h exercise. IMCL levels at rest (P < 0.05) and its depletion during exercise (P < 0.001) were significantly higher in males compared with females, whereas glycogen was stored and used in the same range by both genders. CONCLUSION: During this 3-h exercise, energy supplies from fat and CHO were similar in both genders, and males as well as females reduced their IMCL stores significantly. The larger contribution of IMCL during exercise in males compared with females could either be a result of gender-specific substrate selection, or different long-term training habit.
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Altogether 513 samples from sediments of Cretaceous to Pleistocene age from DSDP Legs 56 and 57 were examined by x-ray methods. The main constituents are clay minerals, quartz, feldspar, opaline silica, and volcanic glass. The sediment composition reflects the position of the sites in relation to the main source area, the Japanese Island Arc. For example, relatively coarse-grained material rich in quartz and feldspar was deposited closest to the islands, whereas finer-grained material rich in clay minerals (mainly smectite and illite, with lesser amounts of kaolinite and chlorite) was deposited farther seaward. Vertical fluctuations in the composition of the sediments show the same trend in all sites and are caused mainly by a fluctuating contribution of biogenic silica with time. A trend reversal in the chlorite/kaolinite ratio at Site 438 supports the conclusion that the subsidence of the Oyashio ancient landmass took place during the middle Miocene. That ratio also indicates a northwest drift in the position of Site 436 by sea floor spreading. Oscillations of the illite/smectite ratio during the Pleistocene at Site 436 show the variations of climate during this period. During early diagenesis potassium is fixed in smectite. With increasing depth of burial a smectite-illite mixed layer is formed, with increasing illite layering. At Sites 434, 440, and 441, stepwise changes confirm intensive tectonic process at the midslope terrace and the lower inner slope of the Japan Trench.
Resumo:
Tit. del vol. 2: Apéndice al derecho internacional de España, que contiene los tratados, leyes recopiladas, reales cédulas pragmáticas, reales órdenes y otros documentos que se citan en el tomo primero de esta obra.
Resumo:
Objective-Although physical activity is beneficial to health, people who exercise at high intensities throughout their lifetime may have increased cardiovascular risk. Aerobic exercise increases oxidative stress and may contribute to atherogenesis by augmented oxidation of plasma lipoproteins. The aim of this study was to examine the relationship between aerobic power and markers of oxidative stress, including the susceptibility of plasma to oxidation. Methods and results-Aerobic power was measured in 24 healthy men aged 29 9 years (mean +/- SD). Plasma was analysed from subjects of high aerobic power (HAP; VO(2)max, 64.6 +/- 6.1 ml/kg/min) and lower aerobic power (LAP;VO(2)max, 45.1 +/- 6.3 ml/kg/min) for total antioxidant capacity (TAC), malondialdehyde (MDA) and susceptibility to oxidation. Three measures were used to quantify plasma oxidizability: (1) lag time to conjugated diene formation (lag time); (2) change in absorbance at 234 nm and; (3) slope of the oxidation curve during propagation (slope). The HAP subjects had significantly lowerTAC (1.38 +/- 0.04 versus 1.42 +/- 0.06 TEAC units; P < 0.05), significantly higher change in absorbance (1.55 +/- 0.21 versus 1.36 +/- 0.17 arbitrary units; P < 0.05), but no difference in MDA (P = 0.6), compared to LAP subjects. There was a significant inverse association between TAC and slope (r = -0.49; P < 0.05). Lipoprotein profiles and daily intake of nutrients did not differ between the groups. Conclusions-These findings suggest that people with high aerobic power, due to extreme endurance exercise, have plasma with decreased antioxidant capacity and higher susceptibility to oxidation, which may increase their cardiovascular risk.
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Elevated plasma homocysteine is recognized as an independent risk factor for cardiovascular disease. Recently, there have been conflicting reports of the relationship between physical activity and homocysteine. A more objective measure of physical activity is cardiorespiratory fitness; however, its relationship with homocysteine has yet to be investigated. The aim of this study was to determine the relationship between cardiorespiratory fitness and plasma homocysteine. Cross-sectional associations between cardiorespiratory fitness (VO(2)max) and plasma homocysteine were examined in 49 men and 11 women. A submaximal bicycle test was used to determine VO(2)max and plasma homocysteine was measured using high performance liquid chromatography with fluorescence detection. Dietary analysis determined B vitamin intake. There was a significant inverse relationship between plasma homocysteine concentration and VO(2)max in women (r = -0.81, P = 0.003) but not in men (r = -0.09, P = 0.95). There were no significant relationships between plasma homocysteine and age, BMI, body fat, total cholesterol, and LDL cholesterol. In summary, elevated cardiorespiratory fitness is associated with decreased plasma homocysteine concentrations in women. (C) 2004 Elsevier Inc. All rights reserved.
Resumo:
This study compared the effect of load distribution using two different webbing designs on oxygen consumption and running kinematics of soldiers. It was hypothesised that running with webbing that distributes the load closer to the body (M83 Assault Vest) would expend less energy compared to running with conventional webbing (CON). Seven soldiers randomly completed three treadmill trials; an unloaded VO(2)max test, and two loaded (8 kg) efficiency tests using either the M83 or CON webbing. The VO(2)max test and the loaded efficiency tests had 4-min stages at 5, 8, 10 and 12km h(-1). Energy expenditure was measured via indirect calorimetry and video analysis was used to determine stride frequency (SF) and stride length (SL) during each trial. Participants using the M83 webbing expended significantly (p < 0.05) less energy at all four running velocities compared to the CON trials. The M83 webbing resulted in smaller changes to SL and SF from the unloaded trial when compared to the CON trial. These results indicate that the M83 vest that is designed to distribute the load closer to the body may have an energy efficiency advantage over conventional webbing when soldiers are running. (C) 2004 Published by Elsevier Ltd.
Resumo:
O futebol é um esporte intermitente, intercalando corridas aeróbias e tiros de alta velocidade. A duraçao da partida torna muito importante o papel do sistema aeróbio para o desempenho e resultado do jogo. Devido à facilidade e baixo custo, os testes de campo, sao muito usados à avaliaçao desta capacidade, sendo o Yo-Yo um dos mais aplicados. O objetivo desse estudo é descrever o perfil de performance aeróbia de jogadores de futebol da divisao de acesso do campeonato gaúcho. Para tal, foi aplicado o Yo-Yo intermitente teste, avaliando a distância total percorrida no teste e o VO 2 max dos atletas. A distância média percorrida pelos jogadores foi de 1844±289,5m, enquanto que o VO 2 max ficou em 52,0 ml.(kg.min)-1.O desempenho dos meios de campo ficou abaixo dos zagueiros, o que nao é desejável. A comparaçao com atletas de outros estudos aponta a necessidade de aumento da capacidade aeróbia
Resumo:
El propósito de este estudio es comprobar los efectos de diferentes planes de entrenamiento en la composición corporal y sobre factores de riesgo cardiovascular en sujetos con sobrepeso. La muestra está compuesta por 6 hombres sedentarios con sobrepeso. Considerando así, a aquellos sujetos con un IMC >25, un perímetro de cintura >88 cm y una ? de los 3 pliegues >57 (subescapular, abdominal y supraespinal). Es condición que no hayan realizado ejercicio sistemáticamente en los últimos 6 meses. Se pide a los participantes que no realicen cambios significativos en sus dietas. Todos adultos de entre 22 y 45 años de edad. La intervención dura 8 semanas, con una frecuencia de 3 veces por semana (lunes, miércoles y viernes). Se realizó a todos una evaluación de los siguientes parámetros de salud cardiovascular: colesterol total, perfil lipídico, tensión arterial, VO 2 máx., IMC, CCi/Ca, ? 3 pliegues cutáneos del tronco, antes y después de finalizar la intervención. Los 6 participantes fueron divididos aleatoriamente en 4 grupos: el grupo control que no realiza ningún plan de entrenamiento; el grupo de ejercicios de fuerza que realizó las primeras 2 semanas 8 ejercicios al 55 de la MR estimativa y las posteriores 6 semanas 10 ejercicios entre el 60 a 65 de la MR estimativa; el grupo de ejercicios aeróbicos que trabajó al 55 - 60 1del VO 2 máx. caminando de forma continua con un volumen de 30 a 40 minutos de duración por sesión; y por último, el grupo de entrenamiento mixto que alternó un día de trabajo de fuerza y un día aeróbico con la misma metodología descripta anteriormente
Resumo:
El propósito de este estudio es comprobar los efectos de diferentes planes de entrenamiento en la composición corporal y sobre factores de riesgo cardiovascular en sujetos con sobrepeso. La muestra está compuesta por 6 hombres sedentarios con sobrepeso. Considerando así, a aquellos sujetos con un IMC >25, un perímetro de cintura >88 cm y una ? de los 3 pliegues >57 (subescapular, abdominal y supraespinal). Es condición que no hayan realizado ejercicio sistemáticamente en los últimos 6 meses. Se pide a los participantes que no realicen cambios significativos en sus dietas. Todos adultos de entre 22 y 45 años de edad. La intervención dura 8 semanas, con una frecuencia de 3 veces por semana (lunes, miércoles y viernes). Se realizó a todos una evaluación de los siguientes parámetros de salud cardiovascular: colesterol total, perfil lipídico, tensión arterial, VO 2 máx., IMC, CCi/Ca, ? 3 pliegues cutáneos del tronco, antes y después de finalizar la intervención. Los 6 participantes fueron divididos aleatoriamente en 4 grupos: el grupo control que no realiza ningún plan de entrenamiento; el grupo de ejercicios de fuerza que realizó las primeras 2 semanas 8 ejercicios al 55 de la MR estimativa y las posteriores 6 semanas 10 ejercicios entre el 60 a 65 de la MR estimativa; el grupo de ejercicios aeróbicos que trabajó al 55 - 60 1del VO 2 máx. caminando de forma continua con un volumen de 30 a 40 minutos de duración por sesión; y por último, el grupo de entrenamiento mixto que alternó un día de trabajo de fuerza y un día aeróbico con la misma metodología descripta anteriormente
Resumo:
El propósito de este estudio es comprobar los efectos de diferentes planes de entrenamiento en la composición corporal y sobre factores de riesgo cardiovascular en sujetos con sobrepeso. La muestra está compuesta por 6 hombres sedentarios con sobrepeso. Considerando así, a aquellos sujetos con un IMC >25, un perímetro de cintura >88 cm y una ? de los 3 pliegues >57 (subescapular, abdominal y supraespinal). Es condición que no hayan realizado ejercicio sistemáticamente en los últimos 6 meses. Se pide a los participantes que no realicen cambios significativos en sus dietas. Todos adultos de entre 22 y 45 años de edad. La intervención dura 8 semanas, con una frecuencia de 3 veces por semana (lunes, miércoles y viernes). Se realizó a todos una evaluación de los siguientes parámetros de salud cardiovascular: colesterol total, perfil lipídico, tensión arterial, VO 2 máx., IMC, CCi/Ca, ? 3 pliegues cutáneos del tronco, antes y después de finalizar la intervención. Los 6 participantes fueron divididos aleatoriamente en 4 grupos: el grupo control que no realiza ningún plan de entrenamiento; el grupo de ejercicios de fuerza que realizó las primeras 2 semanas 8 ejercicios al 55 de la MR estimativa y las posteriores 6 semanas 10 ejercicios entre el 60 a 65 de la MR estimativa; el grupo de ejercicios aeróbicos que trabajó al 55 - 60 1del VO 2 máx. caminando de forma continua con un volumen de 30 a 40 minutos de duración por sesión; y por último, el grupo de entrenamiento mixto que alternó un día de trabajo de fuerza y un día aeróbico con la misma metodología descripta anteriormente
Resumo:
O futebol é um esporte intermitente, intercalando corridas aeróbias e tiros de alta velocidade. A duraçao da partida torna muito importante o papel do sistema aeróbio para o desempenho e resultado do jogo. Devido à facilidade e baixo custo, os testes de campo, sao muito usados à avaliaçao desta capacidade, sendo o Yo-Yo um dos mais aplicados. O objetivo desse estudo é descrever o perfil de performance aeróbia de jogadores de futebol da divisao de acesso do campeonato gaúcho. Para tal, foi aplicado o Yo-Yo intermitente teste, avaliando a distância total percorrida no teste e o VO 2 max dos atletas. A distância média percorrida pelos jogadores foi de 1844±289,5m, enquanto que o VO 2 max ficou em 52,0 ml.(kg.min)-1.O desempenho dos meios de campo ficou abaixo dos zagueiros, o que nao é desejável. A comparaçao com atletas de outros estudos aponta a necessidade de aumento da capacidade aeróbia
Resumo:
El propósito de este estudio es comprobar los efectos de diferentes planes de entrenamiento en la composición corporal y sobre factores de riesgo cardiovascular en sujetos con sobrepeso. La muestra está compuesta por 6 hombres sedentarios con sobrepeso. Considerando así, a aquellos sujetos con un IMC >25, un perímetro de cintura >88 cm y una ? de los 3 pliegues >57 (subescapular, abdominal y supraespinal). Es condición que no hayan realizado ejercicio sistemáticamente en los últimos 6 meses. Se pide a los participantes que no realicen cambios significativos en sus dietas. Todos adultos de entre 22 y 45 años de edad. La intervención dura 8 semanas, con una frecuencia de 3 veces por semana (lunes, miércoles y viernes). Se realizó a todos una evaluación de los siguientes parámetros de salud cardiovascular: colesterol total, perfil lipídico, tensión arterial, VO 2 máx., IMC, CCi/Ca, ? 3 pliegues cutáneos del tronco, antes y después de finalizar la intervención. Los 6 participantes fueron divididos aleatoriamente en 4 grupos: el grupo control que no realiza ningún plan de entrenamiento; el grupo de ejercicios de fuerza que realizó las primeras 2 semanas 8 ejercicios al 55 de la MR estimativa y las posteriores 6 semanas 10 ejercicios entre el 60 a 65 de la MR estimativa; el grupo de ejercicios aeróbicos que trabajó al 55 - 60 1del VO 2 máx. caminando de forma continua con un volumen de 30 a 40 minutos de duración por sesión; y por último, el grupo de entrenamiento mixto que alternó un día de trabajo de fuerza y un día aeróbico con la misma metodología descripta anteriormente