Scientific papers 2010
Next page Next page BUTTON TEXT Previous page Back to the menu 07 - Hyperbaric stress in divers and non-divers: Neuroendocrine and psychomotor responses
Authors: Tom McLellan, Heather Wright, Shan Rhind, Bruce Cameron, & David Eaton. This study compared neuroendocrine and psychomotor responses in divers (d, n=11) and non-divers (Nd, n=9) following 30-minute hyperbaric and decompression stress to 180, 300, and 450 kpa. Venous blood was drawn pre- dive and at 20 and 60 minutes post-dive and analyzed for norepinephrine (Ne), epinephrine (e), tryptophan (trp), cortisol (cor), growth hormone (gH), adrenocorticotrophic hormone (actH), and prolactin (prl). Reaction time was assessed using a psychomotor vigilance task.
19 - Emmanuel Gempp, Jean-Eric Blatteau: Preconditioning methods and mechanisms for preventing the risk of decompression sickness in scuba divers: A review
Scuba divers are at risk of decompression sickness due to the excessive formation of gas bubbles in blood and tissues following ascent, with potentially subsequent neurological injuries. Since nonprovocative dive profiles are no guarantor of protection against this disease, novel means are required for its prevention including predive procedures that could induce more resistance to decompression stress. In this article, the authors review the recent studies describing the promising preconditioning methods that might operate on the attenuation of bubble formation believed to reduce the occurrence of decompression sickness.
29 - High incidence of venous and arterial gas emboli at rest after trimix diving without protocol violations
Authors: Marko Ljubkovic, Jasna Marinovic, Ante Obad, Toni Breskovic, Svein E. Gaustad, and Zeljko Dujic. SCUBA diving is associated with the generation of gas emboli due to gas release from the supersaturated tissues during decompression. Gas emboli arise mostly on the venous side of the circulation, and they are usually eliminated as they pass through the lung vessels. Arterialization of venous gas emboli (VGE) is seldom reported, and it is potentially related to neurological damage and the development of decompression sickness. The goal of the present study was to evaluate the generation of VGE in a group of divers using a mixture of compressed oxygen, helium, and nitrogen (trimix) and to probe for their potential appearance in the arterial circulation.
04 - Effect of in-water oxygen prebreathing at different depths on decompression-induced bubble formation and platelet activation.
Authors: Gerardo Bosco, Zhong-jin Yang, Guglielmo Di Tano, Enrico M. Camporesi, Fabio Faralli, Fabio Savini, Angelo Landolfi, Christian Doria, and Giorgio Fanò. The effect of in-water oxygen prebreathing at different depths on decompression-induced bubble formation and platelet activation in scuba divers was evaluated. Six volunteers participated in four diving protocols, with 2 wk of recovery between dives.
10 - Prognostic factors of spinal cord decompression sickness in recreational diving: Retrospective and multicentric analysis of 279 cases.
Authors: Jean-Eric Blatteau, E. Gempp, O. Simon, M. Coulange, B. Delafosse, V. Souday, G. Cochard, J. Arvieux, A. Henckes, P. Lafere, P. Germonpre, J.-M. Lapoussiere, M. Hugon, P. Constantin, A. Barthelemy. This study aims to determine the potential risk factors associated with the development of severe diving-related spinal cord decompression sickness (DCS).
17 - Recompression and adjunctive therapy for decompression illness: A systematic review of randomized controlled trials
Authors: Michael H. Bennett, MD, Fanzca, Jan P. Lehm, Simon J. Mitchel, Ph.D, Fanzca, Jason Wasiak. Recompression is the universally accepted standard for the treatment of decompression illness (DCI). When recompression is delayed, a number of strategies have been suggested to improve the outcome. The authors examined the effectiveness and safety of both recompression and adjunctive therapies in DCI treatment.
20 - Endurance exercise immediately before sea diving reduces bubble formation in scuba divers
Authors: Olivier Castagna, Jeanick Brisswalter, Nicolas Vallee, Jean- Eric Blatteau Previous studies have observed that a single bout of exercise can reduce the formation of circulating bubbles on decompression, but, according to different authors, several hours of delay were considered necessary between the end of exercise and the beginning of the dive. The objective of this study was to evaluate the effect of a single bout of exercise taken immediately before a dive on bubble formation.
24 - Evaluation of critical flicker fusion frequency and perceived fatigue in divers after air and enriched air nitrox diving
Authors: Pierre Lafere, Ciostantino Balestra, Walker Hemelryck, Nicole Donda, Ahmed Sakr, Adel Taher, & Peter Germonpre Many divers report less fatigue following dives breathing enriched air nitrox than breathing air. A reduction of post fatigue with nitrox would suggest a pathological origin, possibly the presence of asymptomatic nitrogen bubbles in the body after a dive. The authors studied fatigue in 219 healthy divers performing either air or nitrox 32% O2 dives to 21.2 msw for 43.3 min in tropical waters. The divers were assessed before the dive and 30 to 60 minutes after surfacing.
16 - Free energy wells for small gas bubbles in soft deformable materials.
Author: Saul Goldman Thermodynamic expressions are derived for the system relative Gibbs free energy and the relative Gibbs free energy per bubble for all possible equilibrium bubble states that can form in a soft, slightly rigid material, initially supersaturated with a dissolved inert gas N2 . While the thermodynamic manipulations are exact, the final expressions are approximate due to an approximation made in deriving the expression for the elastic free energy of a soft material containing more than a single bubble.
27 - Microparticles initiate decompression-induced neutrophil activation and subsequent vascular injuries.
Authors: Stephen R. Thom, Ming Yang, Veena M. Bhopale, Shaohui Huang, and Tatyana N. Milovanova. Progressive elevations in circulating annexin V-coated microparticles (MPs) derived from leukocytes, erythrocytes, platelets, and endothelial cells are found in mice subjected to increasing decompression stresses. Individual MPs exhibit surface markers from multiple cells. MPs expressing platelet surface markers, in particular, interact with circulating neutrophils, causing them to degranulate and leading to further MP production.
15 - Free radicals, antioxidants and functional foods: Impact on human health.
Authors: V. Lobo, A. Patil, A. Phatak, N. Chandra Last research about decompresion illness and the use of oxygen highlight the role of free radicals. The body generates free radicals, reactive oxygen species, and reactive nitrogen species by various endogenous systems, exposure to different physiochemical conditions, or pathological states. A balance between free radicals and antioxidants is necessary for proper physiological function. Suppose free radicals overwhelm the body’s ability to regulate them, and a condition known as oxidative stress ensues. Free radicals thus adversely alter lipids, proteins, and DNA and trigger many human diseases.
14 - Effects of hyperoxia on ventilation and pulmonary hemodynamics during immersed prone exercise at 4.7 ATA: possible implications for immersion pulmonary edema
Authors: Dionne F. Peacher, Shelly R. H. Pecorella, John J. Freiberger, Michael J. Natoli, Eric A. Schinazi, P. Owen Doar, Albert E. Boso, Aaron J. Walker, Matthew Gill, Dawn Kernagis, Donna Uguccioni, and Richard E. Moon Based on the fact that previous studies revealed a progressive increase in ventilation during prolonged immersed exercise, the authors hypothesized that this increase occurs because of the development of metabolic acidosis with a concomitant rise in mean pulmonary artery pressure and that hyperoxia attenuates this increase.
21 - Thalmann Algorithm Decompression Table Generation Software Design Document
Authors: Wayne A. Gerth The Thalmann Decompression Algorithm (EL-DCA) was developed using VVal-18 and HVal-21. The original EL- DCA was extensively modified to develop MK 16 MOD 1 N2 -O2 and He-O2 decompression tables and Submarine Rescue and Diving Recompression System Operator/Tender decompression tables. The EL-DCA was further modified and used with a modified VVal-18 parameter set, designated VVal-18M, to produce an integrated set of air diving decompression tables for Revision 6 of the U.S. Navy Diving Manual.
05 - Barrier Function Nonlinear Optimization for Optimal Decompression of Divers.
Authors: Le Feng, Christian R. Gutvik, Tor A. Johansen, Dan Sui This paper is based on a comprehensive dynamic mathematical model of vascular bubble formation and growth during and after decompression from a dive. The model describes the underlying relationship between Venous Gas Emboli (VGE) and severe Decompression Sickness (DCS) risk. Using the Copernicus model, the diving decompression problem can be formulated as a nonlinear optimal control problem, where the objective is to minimize the total ascend time subject to constraints on the maximum number of bubbles in the pulmonary artery (also referred to as the decompression stress).
01 - The clinical utility of long-term humidification therapy in chronic airway disease
Authors: Harold Rea, Sue McAuley, Lata Jayaram, Jeffrey Garrett, Hans Hockey, Louanne Storey, Glenis O’Donnell, Lynne Haru, Matthew Payton, Kevin O’Donnell Persistent airway inflammation with mucus retention in patients with chronic airway disorders such as COPD and bronchiectasis may lead to frequent exacerbations, reduced lung function, and poor quality of life. This study investigates whether long-term humidification therapy with high-flow, fully humidified air at 37 °C through nasal cannulae can improve these clinical outcomes in this group of patients. On the diving side, this study is to be linked to the quality of breathing gases and conditions resulting from airway inflammation.
18 - Taravana: Documentation of Bubbles by Computerized Tomography
Authors: Mario Alaimo, Giuseppe Aiello, Eduardo Marino, Leila Zummo, Francesco Cappello The authors report a case of a 41-year-old expert diver who, after a series of brath hold dives (60 to 80s/dive at 20 to 24m of depth for 5 consecutive hours), experienced vertigo, ringing in the left ear, and confusion, followed by right arm paresthesia trailed by right hemi-paresis after a few minutes. After <60 minutes from the emergence of these symptoms, he was admitted to the emergency unit of our hospital with less severe clinical features, presenting only confusion and paresthesia of the right hand.
02 - Paget-Schroetter Syndrome: Review of Pathogenesis and Treatment of Effort Thrombosis
Authors: Venkata M. lla, Nagendra Natarajan, Manu Kaushik, Rugmini Warrier, Chandra K. Nair Effort thrombosis, or Paget-Schroetter Syndrome, refers to axillary-subclavian vein thrombosis associated with strenuous and repetitive activity of the upper extremities. Anatomical abnormalities at the thoracic outlet and repetitive trauma to the endothelium of the subclavian vein are key factors in its initiation and progression. The role of hereditary and acquired thrombophilias is unclear. The pathogenesis of effort thrombosis is thus distinct from other venous thromboembolic disorders. Doppler ultrasonography is the preferred initial test, while contrast venography remains the gold standard for diagnosis.
11 - An Estimation of the Extent of Animal Use in Research in Brazil, as Determined by Bibliographic Sampling from Journals Published in the State of Paraná
Authors: Vanessa Carli Bones Silla, Elaine Cristina de Oliveira Sans and Carla Forte Maiolino Molento Animal use in research is an issue of increasing ethical concern. The objective of this work was to investigate animal usage in research described in the papers appearing in 18 journals published in the State of Paraná in 2006. The fields used in the bibliographic sampling were agrarian science, biological science, biological and health science, environmental science, food technology, and health science. Of the 865 papers analyzed, 41% involved the use of animals, totaling a total of 3,497,653 animals, of which 216,223 were vertebrates.
13 - Cellular Effects of Helium in Different Organs
Author: Gezina T.M.L. Oei, Nina C. Weber, Markus W. Hollmann, Benedikt Preckel This review covers the cellular effects of helium, which research in cardiac and neuronal tissue has shown that, besides volatile anesthetics and xenon, the non-anesthetic noble gas helium also reduces ischemic pre-perfusion damage. It shows that using this gas may lead to new clinical strategies for tissue salvage in ischemia-reperfusion situations, both within and outside the perioperative setting. This should be considered when designing decompression tables.
03 - Future synergism in diving accident management: The Singapore model.
Authors: Chong Si Jack, Liang Weihao, Kim Soo Joang and Kang Wee Lee The growing popularity of recreational diving has led to an increase in diving-related injuries and a higher demand for specialized medical treatment. In response, Singapore General Hospital (SGH) has established the new Hyperbaric and Diving Medicine Centre, strengthening collaboration with the Singapore Navy Medical Service (NMS). This partnership, cemented by a recent Memorandum of Understanding, utilizes NMS's expertise and SGH's resources to advance research, training, and the formal recognition of diving and hyperbaric medicine as a medical subspecialty.
26 - A case of decompression illness during saturation diving
Authors: Rohit Verma This study discusses a case of musculoskeletal DCI post- saturation diving, underscoring the unpredictable nature of DCI and its impact on an individual's fitness for diving.
25 - Venous and Arterial Bubbles at Rest after No-Decompression Air Dives.
Authors: Marko Ljubkovic, Zeljko Dujic, Andreas Mollerlokken, Darija Bakovic, Ante Obad, Toni Brekovic, and Alf O. Brubakk The study examined the occurrence and frequency of venous gas emboli (VGE) after no-stop air dives. Twelve divers performed six dives each under standard no- decompression procedures and were monitored for VGE via ultrasound for 120 minutes post-dive. The results showed a high production of gas bubbles, primarily grade 4, with VGE detected in the systemic circulation of 41.7% of divers, particularly when significant bubble presence was noted in the heart's right valve. Despite the frequent detection of VGE, no decompression-related health issues were observed.
06 - Natural Killer Cells as Biomarkers of Hyperbaric Stress During a Dry Heliox Saturation Dive
Authors: Jan Krog, Else K. Tønnesen, Claus F. Jepsen, Erik Parner, Kåre Segadal, Arvid Hope, Rune J. Ulvik, and Marianne E. Hokland This text presents a scientific study that investigates the effects of hyperbaric exposure on the human immune system, specifically focusing on the distribution and activity of natural killer (NK) cells. The study aims to determine whether monitoring specific lymphocyte subsets, including T- and NK-cell subsets, can serve as biomarkers for hyperbaric stress. The text details the methods used, including the isolation of peripheral blood mononuclear cells and the use of 4-color flow cytometry to delineate lymphocyte subpopulations.
08 - Thermal Problems in Hyperbaric Environments
Author: Naoshi Kakitsuba This study reviews and provides information on thermal problems and thermal comfort zones in hyperbaric environments, mainly focusing on the challenges faced by divers in hyperbaric helium-oxygen atmospheres. The paper discusses the effects of helium's high thermal conductivity and increased pressure on heat exchange between divers and their environment and presents findings from studies on clothing insulation and permeability under different pressures. The ultimate goal is to demonstrate the comfort range of ambient temperatures at increased barometric pressures.
09 - Cold thermoregulatory responses following exertional fatigue
Author: John W. Castellani, Michael N. Sawka, David W. DeGroot, Andrew J. Young The purpose of this document is to inform readers about the condition known as "thermoregulatory fatigue," which affects individuals engaged in prolonged, physically demanding cold-weather activities. The text explains the physiological responses to cold exposure, such as shivering and peripheral vasoconstriction, and discusses how these responses can be impaired by prolonged or repeated cold exposure and sustained physical exertion. The text also highlights the potential mechanisms behind this impairment and the increased risk of hypothermia associated with thermoregulatory fatigue.
12 - Interactions of Multiple Gas-Transducing Systems: Hallmarks and Uncertainties of CO, NO, and H2S Gas Biology
Authors: Mayumi Kajimura, Ryo Fukuda, Ryon M. Bateman, Takehiro Yamamoto, and Makoto Suematsu This document reviews and discusses the physiological roles and interactions of the body's biological gases (O2, CO, NO, and H2S). It highlights the significance of these gases as signaling molecules, their interactions with heme- based proteins, and their effects on mitochondrial functions such as respiration, biogenesis, and suspended animation. The review addresses key issues in "gas biology," including effective tissue concentrations and the proximity between gas-producing and gas- receptor/sensor sites.
22 - Autonomic activation links CNS oxygen toxicity to acute cardiogenic pulmonary injury
Authors: Ivan T. Demchenko, Yu Zhilyaev, A. N. Moskvin, Claude A. Piantadosi, and Barry W. Allen This text intends to present scientific research findings on the effects of hyperbaric oxygen (HBO2) exposure at high pressures on the pulmonary and cardiovascular systems. The text aims to explain the mechanisms behind acute pulmonary injury caused by HBO2, mainly focusing on the role of autonomic nervous system activation and its impact on pulmonary vascular pressure and heart function. The research involves experiments on rats to measure various physiological parameters and to test the hypothesis that HBO2 exposure leads to significant sympathetic outflow, resulting in pulmonary and cardiovascular complications.
23 - Roles of dietary inorganic nitrate in cardiovascular health and disease
Authors: Jon O. Lundberg, Mattias Carlstrom, Filip J. Larsen, and Eddie Weitzberg This document informs and highlights the emerging understanding of the health benefits of inorganic nitrate, particularly from dietary sources such as vegetables. It discusses the potential mechanisms through which nitrate exerts its effects, including the generation of nitric oxide and other reactive nitrogen oxides, and its impact on cardiovascular health, exercise performance, and oxidative stress. The text aims to convey the significance of nitrate in reducing blood pressure, protecting against cardiovascular disorders, and potentially contributing to the beneficial health effects of a vegetable-rich diet.
30 - Autonomic activation links CNS oxygen toxicity to acute cardiogenic pulmonary injury
Authors: Ivan T. Demchenko, S. Yu Zhilyaev, A.N. Moskvin, Claude A. Piantadosi, and Barry W. Allen This study aims to elucidate the mechanisms behind acute pulmonary injury caused by HBO2, particularly focusing on the role of autonomic nervous system activity and hemodynamic changes. The research involves experiments on rats to measure various physiological parameters and test the hypothesis that extreme HBO2 exposure leads to significant pulmonary vascular pressure increases and subsequent barotrauma. The findings suggest that these effects are due to central sympathetic excitation and catecholamine release, which disrupt the balance in the autonomic nervous system.
31 - Hypoxia Induces Late Preconditioning in the Rat Heart In Vivo
Authors: Marc M. Berger, Ragnar Huhn, Gezina T. Oei, Andre´ Heinen, Andreas Winzer, Inge Bauer, Benedikt Preckel, Nina C. Weber, Wolfgang Schlack, Markus W. Hollmann This scientific study investigates the cardioprotective effects of hypoxic late preconditioning (LPC) in vivo, specifically in rat hearts. The study aims to determine whether hypoxic LPC can reduce ischemia-reperfusion injury and compares its effectiveness to sevoflurane preconditioning. The text details the methods used, the results obtained, and the conclusion that hypoxic LPC significantly reduces infarct size, with protein kinase C (PKC) playing a key role in this protective effect.
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28 - Oxygen pretreatment as protection against decompression sickness in rats: pressure and time necessary for hypothesized denucleation and renucleation
Authors: Ran Arieli, Elran Boaron, Yehuda Arieli, Amir Abramovich, Ksenya Katsenelson This study investigated the effectiveness of different hyperbaric oxygen (HBO) pretreatment protocols in reducing the incidence of decompression sickness (DCS) in a rat model to determine the optimal oxygen pressure and exposure duration for pretreatment, as well as how long the pretreatment remains effective. Its authors also discuss the results of various pretreatment conditions and their impact on the occurrence of DCS, highlighting the potential mechanisms involved, such as the activation of dormant micronuclei and the rejuvenation of micronuclei over time.