HE2B - HE: Recent submissions
Voici les éléments 21-40 de 116
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Pulmonary Effects of One Week of Repeated Recreational Closed-Circuit Rebreather Dives in Cold Water
28 décembre 2022, HE Bruxelles BrabantArticle scientifiqueBackground and Objectives: The use of closed-circuit rebreathers (CCRs) in recreational diving is gaining interest. However, data regarding its physiological effects are still scarce. Immersion, cold water, hyperoxia, exercise or the equipment itself could challenge the cardiopulmonary system. The purpose of this study was to examine the impact of CCR diving on lung function and autonomous cardiac ... -
Architectural and Mechanical Changes after Five Weeks of Intermittent Static Stretch Training on the Medial Gastrocnemius Muscle of Active Adults
27 mars 2023, HE Bruxelles BrabantArticle scientifiqueWe investigated the effects of intermittent long-term stretch training (5 weeks) on the architectural and mechanical properties of the muscle-tendon unit (MTU) in healthy humans. MTU's viscoelastic and architectural properties in the human medial gastrocnemius (MG) muscle and the contribution of muscle and tendon structures to the MTU lengthening were analyzed. Ten healthy volunteers participated ... -
Oxygen Variations-Insights into Hypoxia, Hyperoxia and Hyperbaric Hyperoxia - Is the Dose the Clue?
20 septembre 2023, HE Bruxelles BrabantArticle scientifiqueon, nitrogen and hydrogen); aerobic organisms depend on it to release energy from carbon-based molecules. The concentration of oxygen in the atmosphere is ~20.93–20.95% (209–460 ppm), but this has fluctuated markedly throughout geological history. It stabilized within a habitable range, between ~15% and 35%, which has been maintained from the Cambrian period 540 million years ago until today [1]. The ... -
Heart Rate Variability During a Standard Dive: A Role for Inspired Oxygen Pressure?
13 août 2021, HE Bruxelles BrabantArticle scientifiqueIntroduction: Heart rate variability (HRV) during underwater diving has been infrequently investigated because of environment limitations and technical challenges. This study aims to analyze HRV changes while diving at variable hyperoxia when using open circuit (OC) air diving apparatus or at constant hyperoxia using a closed-circuit rebreather (CCR). We used HRV analysis in time and frequency domain ... -
Comparison of insulation provided by dry or wetsuits among recreational divers during cold water immersion (< 5 degrees C)
05 octobre 2021, HE Bruxelles BrabantArticle scientifiqueBACKGROUND: Divers thermal status influences susceptibility to decompression sickness hence the need for proper insulation during immersion in cold water. However, there is a lack of data on thermal protection provided by diving suits, hence this study. MATERIALS AND METHODS: Two different groups of divers wearing either a wetsuit (n = 15) or a dry suit (n = 15) volunteered for this study. Anthropometric ... -
Comparison of insulation provided by dry or wetsuits among recreational divers during cold water immersion (< 5 degrees C)
05 octobre 2021, HE Bruxelles BrabantArticle scientifiqueBACKGROUND: Divers thermal status influences susceptibility to decompression sickness hence the need for proper insulation during immersion in cold water. However, there is a lack of data on thermal protection provided by diving suits, hence this study. MATERIALS AND METHODS: Two different groups of divers wearing either a wetsuit (n = 15) or a dry suit (n = 15) volunteered for this study. Anthropometric ... -
The "ON-OFF" Switching Response of Reactive Oxygen Species in Acute Normobaric Hypoxia: Preliminary Outcome
16 février 2023, HE Bruxelles BrabantArticle scientifiqueExposure to acute normobaric hypoxia (NH) elicits reactive oxygen species (ROS) accumulation, whose production kinetics and oxidative damage were here investigated. Nine subjects were monitored while breathing an NH mixture (0.125 F(I)O(2) in air, about 4100 m) and during recovery with room air. ROS production was assessed by Electron Paramagnetic Resonance in capillary blood. Total antioxidant ... -
Oxidative Stress Response’s Kinetics after 60 Minutes at Different (30% or 100%) Normobaric Hyperoxia Exposures
30 décembre 2022, HE Bruxelles BrabantArticle scientifiqueOxygen is a powerful trigger for cellular reactions and is used in many pathologies, including oxidative stress. However, the effects of oxygen over time and at different partial pressures remain poorly understood. In this study, the metabolic responses of normobaric oxygen intake for 1 h to mild (30%) and high (100%) inspired fractions were investigated. Fourteen healthy nonsmoking subjects (7 ... -
Heart Rate Variability During a Standard Dive: A Role for Inspired Oxygen Pressure?
13 août 2021, HE Bruxelles BrabantArticle scientifiqueIntroduction: Heart rate variability (HRV) during underwater diving has been infrequently investigated because of environment limitations and technical challenges. This study aims to analyze HRV changes while diving at variable hyperoxia when using open circuit (OC) air diving apparatus or at constant hyperoxia using a closed-circuit rebreather (CCR). We used HRV analysis in time and frequency domain ... -
A fully automated method for late ventricular diastole frame selection in post-dive echocardiography without ECG gating
02 mars 2021, HE Bruxelles BrabantArticle scientifiqueVenous gas emboli (VGE) are often quantified as a marker of decompression stress on echocardiograms. Bubble-counting has been proposed as an easy to learn method, but remains time-consuming, rendering large dataset analysis impractical. Computer automation of VGE counting following this method has therefore been suggested as a means to eliminate rater bias and save time. A necessary step for this ... -
The effect of a passive stretch training protocol on performance during a drop jump in humans
30 mars 2013, HE Bruxelles BrabantArticle scientifiqueOur study's aim is to show how a five-week stretch training protocol, based on passive stretching, can change muscle performance during a drop jump (stretch shortening cycle). METHODS: This study observes in 8 healthy subjects (four males and four females), the effect of a 5-week passive stretch training protocol on the stretch shortening cycle (SSC) during the performance of a drop jump, and identify ... -
A fully automated method for late ventricular diastole frame selection in post-dive echocardiography without ECG gatingEr
02 mars 2021, HE Bruxelles BrabantArticle scientifiqueVenous gas emboli (VGE) are often quantified as a marker of decompression stress on echocardiograms. Bubble-counting has been proposed as an easy to learn method, but remains time-consuming, rendering large dataset analysis impractical. Computer automation of VGE counting following this method has therefore been suggested as a means to eliminate rater bias and save time. A necessary step for this ... -
Relationships between plasma lipids, proteins, surface tension and post-dive bubbles
13 février 2015, HE Bruxelles BrabantArticle scientifiqueDecompression sickness (DCS) in divers is caused by bubbles of inert gas. When DCS occurs, most bubbles can be found in the venous circulation: venous gas emboli (VGE). Bubbles are thought to be stabilized by low molecular weight surfactant reducing the plasma-air surface tension (γ). Proteins may play a role as well. We studied the interrelations between these substances, γ and VGE, measured before ... -
The "normobaric oxygen paradox": a new tool for the anesthetist?
10 janvier 2014, HE Bruxelles BrabantArticle scientifiqueHypoxia is the natural trigger for endogenous EPO production but recently the use of intermittent hyperoxia to stimulate EPO has been postulated and this phenomenon has been called the "normobaric oxygen paradox" (NOP). The "NOP" is a mechanism by which oxygen regulates the expression of the Hypoxia Inducible Factor 1 alpha (HIF-1alpha). The HIF-1alpha-depending gene regulation is responsible for ... -
Fluoxetine stimulates anti-inflammatory IL-10 cytokine production and attenuates sensory deficits in a rat model of decompression sickness
22 octobre 2015, HE Bruxelles BrabantArticle scientifiqueDespite "gold standard" hyperbaric oxygen treatment, 30% of patients suffering from neurological decompression sickness still exhibit incomplete recovery, including sensory impairments. Fluoxetine, a well-known antidepressant, is recognized as having anti-inflammatory effects in the setting of cerebral ischemia. In this study, we focused on the assessment of sensory neurological deficits and measurement ... -
Age, weight and decompression sickness in rats
16 mars 2016, HE Bruxelles BrabantArticle scientifiqueObjective: The aim of this study was to determine if, after controlling for weight, age is associated with decompression sickness (DCS) in rats. Methods: Following compression-decompression, male rats aged 11 weeks were observed for DCS. After two weeks recovery, surviving rats were re-dived using the same compression-decompression profile. Results: In this experiment, there was a clear difference ... -
Colonic Fermentation Promotes Decompression sickness in Rats
08 février 2016, HE Bruxelles BrabantArticle scientifiqueMassive bubble formation after diving can lead to decompression sickness (DCS). During dives with hydrogen as a diluent for oxygen, decreasing the body's H2 burden by inoculating hydrogen-metabolizing microbes into the gut reduces the risk of DCS. So we set out to investigate if colonic fermentation leading to endogenous hydrogen production promotes DCS in fasting rats. Four hours before an experimental ... -
Effect of simulated air dive and decompression sickness on the plasma proteome of rats
12 avril 2016, HE Bruxelles BrabantArticle scientifiquePurpose: Decompression sickness (DCS) is a poorly understood systemic disease caused by inadequate desaturation following a reduction in ambient pressure. Although recent studies highlight the importance of circulating factors, the available data are still puzzling. In this study, we aimed to identify proteins and biological pathways involved in the development of DCS in rats. Experimental design: ... -
Effect of oxygen-breathing during a decompression-stop on bubble-induced platelet activation after an open-sea air dive: oxygen-stop decompression
29 septembre 2013, HE Bruxelles BrabantArticle scientifiquePurpose: We highlighted a relationship between decompression-induced bubble formation and platelet micro-particle (PMP) release after a scuba air-dive. It is known that decompression protocol using oxygen-stop accelerates the washout of nitrogen loaded in tissues. The aim was to study the effect of oxygen deco-stop on bubble formation and cell-derived MP release. Methods: Healthy experienced ... -
Effect of decompression-induced bubble formation on highly trained divers microvascular function
07 novembre 2013, HE Bruxelles BrabantArticle scientifiqueWe previously showed microvascular alteration of both endothelium-dependent and -independent reactivity after a single SCUBA dive. We aimed to study mechanisms involved in this postdive vascular dysfunction. Ten divers each completed three protocols: (1) a SCUBA dive at 400 kPa for 30 min; (2) a 41-min duration of seawater surface head immersed finning exercise to determine the effect of immersion ...