Using an exercise device that integrates maximal voluntary static contraction (MVC) of knee extensor muscles with dynamic knee extension, we compared progressive muscle fatigue, i.e., rate of decline in force-generating capacity, in normoxia (758 Torr) and hypobaric hypoxia (464 Torr). Eight healthy men performed exhaustive constant work rate knee extension (21 +/- 3 W, 79 +/- 2 and 87 +/- 2% o...

Background: Mesenchymal stem cells (MSCs) are important candidates for MSC-based cellular therapy. Current paradigm states that MSCs support local progenitor cells in damaged tissue through paracrine signaling. Therefore, study of paracrine effects and secretome of MSCs could lead to the appreciation of mechanisms and molecules associated with the therapeutic effects of these cells. This study ...

Exercise efficiency is an important determinant of exercise capacity. However, little is known about the physiological factors that can modulate muscle efficiency during exercise. We examined whether improved O2 availability would 1) impair mitochondrial efficiency and shift the energy production toward aerobic ATP synthesis and 2) reduce the ATP cost of dynamic contraction owing to an improved...

OBJECTIVES We studied the acute effect of caffeine on myocardial blood flow (MBF) at rest and exercise in healthy volunteers at normoxia and during acute exposure to simulated altitude. BACKGROUND Caffeine is a widely consumed stimulant, although its cardiovascular safety remains controversial and its effect on MBF is unknown. METHODS 15O-labeled H2O and positron emission tomography (PET) w...

This duration may appear to be short. The BLUE protocol was performed by experienced operators it is true, but this was done with the aim of not interfering with the management that was underway. Doctors integrating the BLUE protocol in patient management are free to take more time. Several points explain our data, however. Since 1992, we have labeled our whole-body approach “fast-echo” because...

Abstract Introduction Glutaminolysis, beside glycolysis, is a key metabolic pathway of cancer cell that provides energy and substrates for the synthesis nucleic acids, proteins, lipids. The mediated by both mitochondrial cytosolic enzymes. Neither expression glutaminolysis enzymes in colon cells nor influence various oxygen concentrations on their has been studied so far. Objectives aim study w...

Purpose Postcardiac arrest syndrome (PCAS) shares many features with sepsis including plasma cytokine elevation with dysregulation of cytokine production, and the presence of endotoxin in plasma. PCAS is closely related to ischemia-reperfusion injury. During ischemia-reperfusion injury, neutrophil, which is the first line of innate immunity, plays a major role. In this study, we investigated th...

Modarreszadeh and Bruce (J. Appl. Physiol. 76: 2765-2775, 1994) proposed that continuous random disturbances in arterial PCO2 are more likely to elicit ventilatory oscillation patterns that mimic periodic breathing in normoxia than in hyperoxia. To test this hypothesis experimentally, in nine awake humans we applied pseudorandom binary inspired CO2 fraction stimulation in normoxia and hyperoxia...

1. Exposure of 10 R3-R13 neurones to a 115-min period of hypoxia resulted in depolarization of their membrane potentials (EM) from a mean of -46-9 ± 3-1 to-20-8 ± 4-4mV (S.E.). 2. Intracellular potassium ion activities (a^) decreased significantly from 118-9 ± 5 1 to 67-7 ± 8-5rnM-K. This is equivalent to a change in EKirom — 70-9 mV to —54-5 mV, which is insufficient to account for depolarizat...

BACKGROUND Providing supplemental oxygen is fundamental in the management of mechanically ventilated patients. Increasing amounts of data show worse clinical outcomes associated with hyperoxia. However, these previous data in the critically ill have not focused on outcomes associated with brief hyperoxia exposure immediately after endotracheal intubation. Therefore, the objectives of this study...