Parcourir Santé par auteur "Lafère, Pierre"
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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 ... -
Critical Flicker Fusion Frequency: A Marker of Cerebral Arousal During Modified Gravitational Conditions Related to Parabolic Flights
02 octobre 2018, HE Bruxelles BrabantArticle scientifiqueIn situ evaluation of human brain performance and arousal remains challenging during operational circumstances, hence the need for a rapid, reliable and reproducible tool. Here we hypothesized that the Critical flicker fusion frequency (CFFF) reflecting/requiring visual integration, visuo-motor skills and decision-taking process might be a powerful, fast and simple tool in modified gravity environments. ... -
Decreased Incidence of Pulmonary Barotrauma After Discontinuation of Emergency Free Ascent Training
22 août 2018, HE Bruxelles BrabantArticle scientifiqueINTRODUCTION: Because a significant association between training to perform emergency free ascent (EFA) and the occurrence of pulmonary barotrauma (PBT) was demonstrated in 2006, the Belgian Underwater Federation (BUF) decided to discontinue this procedure. An evaluation was needed 10 yr after the implementation of this change. METHODS: All medical records with a diagnosis of PBT that occurred in ... -
Do Environmental Conditions Contribute to Narcosis Onset and Symptom Severity?
14 octobre 2016, HE Bruxelles BrabantArticle scientifiqueAlthough many factors contributing to inert gas narcosis onset and severity have been put forward, the available evidence is not particularly strong. Using objective criteria, we have assessed brain impairment associated with narcosis under various environmental diving conditions. 40 volunteers performed a no-decompression dive (33 m for 20 min) either in a dry chamber, a pool or open sea. They were ... -
Early detection of diving-related cognitive impairment of different nitrogen-oxygen gas mixtures
30 juin 2019, HE Bruxelles BrabantArticle scientifiqueNTRODUCTION: Cognitive impairment related to inert gas narcosis (IGN) is a threat to diving safety and operations at depth that might be reduced by using enriched air nitrox (EANx) mixtures. Using critical flicker fusion frequency (CFFF), a possible early detection of cognitive abilities/cerebral arousal impairment when breathing different oxygen (O2) fractions was investigated. METHODS: Eight male ... -
Evidence of Heritable Determinants of Decompression Sickness in Rats
22 juillet 2017, HE Bruxelles BrabantArticle scientifiqueNTRODUCTION: Decompression sickness (DCS) is a complex and poorly understood systemic disease caused by inadequate desaturation following a decrease of ambient pressure. Strong variability between individuals is observed for DCS occurrence. This raises questions concerning factors that may be involved in the inter-individual variability of DCS occurrence. This study aimed to experimentally assess ... -
Field study of anthropomorphic and muscle performance changes among elite skippers following a transoceanic race
12 juin 2020, HE Bruxelles BrabantArticle scientifiqueBACKGROUND: Ocean racing has become increasingly demanding, both physically and psychologically. The aim of the study was to assess global changes after a transoceanic race. MATERIALS AND METHODS: Eight male sailors were evaluated pre- and post-race through anthropometric measurements (weight, skinfold, girth at different level and estimated body fat percentage), multifrequency tetrapolar bioelectrical ... -
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 ... -
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 ... -
Increasing Oxygen Partial Pressures Induce a Distinct Transcriptional Response in Human PBMC: A Pilot Study on the “Normobaric Oxygen Paradox”
05 janvier 2021, HE Bruxelles BrabantArticle scientifiqueThe term "normobaric oxygen paradox" (NOP), describes the response to the return to normoxia after a hyperoxic event, sensed by tissues as oxygen shortage, and resulting in up-regulation of the Hypoxia-inducible factor 1alpha (HIF-1alpha) transcription factor activity. The molecular characteristics of this response have not been yet fully characterized. Herein, we report the activation time trend ... -
The 'normobaric oxygen paradox': does it increase haemoglobin?
14 juin 2012, HE Bruxelles BrabantArticle scientifiqueBackground: A novel approach to increasing erythropoietin (EPO) using oxygen (O2) (the 'normobaric oxygen paradox') has been reported in healthy volunteers. We investigated whether the EPO increase is sufficient to induce erythropoiesis by comparing two protocols of O2 administration. Methods: We compared the effect of daily versus alternate days 100% O2, breathed for 30 minutes, on haemoglobin ... -
Objective vs. Subjective Evaluation of Cognitive Performance During 0.4-MPa Dives Breathing Air or Nitrox
19 avril 2017, HE Bruxelles BrabantArticle scientifiqueBACKGROUND: Divers try to limit risks associated with their sport, for instance by breathing enriched air nitrox (EANx) instead of air. This double blinded, randomized trial was designed to see if the use of EANx could effectively improve cognitive performance while diving. METHODS: Eight volunteers performed two no-decompression dry dives breathing air or EANx for 20 min at 0.4 MPa. Cognitive ... -
Oxidative Stress Response Kinetics after 60 Minutes at Different (1.4 ATA and 2.5 ATA) Hyperbaric Hyperoxia Exposures
02 août 2023, HE Bruxelles BrabantArticle scientifiqueHyperbaric oxygen therapy (HBOT) is a therapeutical approach based on exposure to pure oxygen in an augmented atmospheric pressure. Although it has been used for years, the exact kinetics of the reactive oxygen species (ROS) between different pressures of hyperbaric oxygen exposure are still not clearly evidenced. In this study, the metabolic responses of hyperbaric hyperoxia exposures for 1 h at ... -
Oxidative Stress Response Kinetics after 60 Minutes at Different Levels (10% or 15%) of Normobaric Hypoxia Exposure
15 juin 2023, HE Bruxelles BrabantArticle scientifiqueIn this study, the metabolic responses of hypoxic breathing for 1 h to inspired fractions of 10% and 15% oxygen were investigated. To this end, 14 healthy nonsmoking subjects (6 females and 8 males, age: 32.2 ± 13.3 years old (mean ± SD), height: 169.1 ± 9.9 cm, and weight: 61.6 ± 16.2 kg) volunteered for the study. Blood samples were taken before, and at 30 min, 2 h, 8 h, 24 h, and 48 h after a 1 ... -
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 ... -
Patent Foramen Ovale (PFO), Personality Traits, and Iterative Decompression Sickness. Retrospective Analysis of 209 Cases
20 août 2017, HE Bruxelles BrabantArticle scientifiqueIntroduction: There is a need to evaluate the influence of risk factors such as patency of foramen ovale (PFO) or "daredevil" psychological profile on contra-indication policy after a decompression sickness (DCS). Methods: By crossing information obtained from Belgian Hyperbaric Centers, DAN Emergency Hotline, the press, and Internet diving forums, it was possible to be accountable for the majority ... -
Physiological characteristics associated with increased resistance to decompression sickness in male and female rats
23 juillet 2020, HE Bruxelles BrabantArticle scientifiqueDecompression sickness (DCS) is a complex and poorly understood systemic disease with wide inter-individual resistance variability. We selectively bred rats with a 3-fold greater resistance to DCS than standard ones. To investigate possible physiological mechanisms underlying the resistance to DCS, including sex-related differences in these mechanisms, 15 males and 15 females resistant to DCS were ... -
Physiology of repeated mixed gas 100-m wreck dives using a closed-circuit rebreather: a field bubble study
28 novembre 2021, HE Bruxelles BrabantArticle scientifiquePurpose: Data regarding decompression stress after deep closed-circuit rebreather (CCR) dives are scarce. This study aimed to monitor technical divers during a wreck diving expedition and provide an insight in venous gas emboli (VGE) dynamics. Methods: Diving practices of ten technical divers were observed. They performed a series of three consecutive daily dives around 100 m. VGE counts were ... -
Pre-dive Whole-Body Vibration Better Reduces Decompression-Induced Vascular Gas Emboli than Oxygenation or a Combination of Both
30 novembre 2016, HE Bruxelles BrabantArticle scientifiquePurpose: Since non-provocative dive profiles are no guarantor of protection against decompression sickness, novel means including pre-dive "preconditioning" interventions, are proposed for its prevention. This study investigated and compared the effect of pre-dive oxygenation, pre-dive whole body vibration or a combination of both on post-dive bubble formation. Methods: Six healthy volunteers performed ...