scientific-2011-2012

Scientific papers 2011 - 2012

9 - Doolette, Gerth & Gault: Redistribution of decompression stop time from shallow to deep stops increases incidence of decompression sickness in air decompression dives.

Classical decompression algorithms limit hypothetical tissue gas contents and prescribe decompression schedules with most of the total stop time (TST) allocated to shallow decompression stops. More recent bubble-model-based algorithms limit hypothetical bubble profusion and size and prescribe decompressions with TST skewed toward deeper stops. This paper describes a man-trial that was organized to compare the efficiency of these approaches.

The Thalmann Algorithm parameterized with VVal-18 or VVal-18M underlies U.S. Navy air and nitrox decompression procedures.VVal-18 and VVal-18M air no- stop limits at many depths are longer than the corresponding no-stop limits in the 1957 standard air decompression table that appeared in the U.S. Navy Diving Manual from 1959 until it was replaced in Revision 6 (2008). However, the severity of DCS observed in man- trials of the longer no-stop limits was unacceptable, and consequently, in the Revision 6 air decompression tables, the 1957 air no-stop limits were arbitrarily retained in place of any longer VVal-18M-prescribed limits. This report describes VVal-79, a modification of the VVal- 18M parameter set that enables the use of the Thalmann algorithm to prescribe air diving no-stop limits and decompression obligations that can be used as it is, with no need for arbitrary edits to individual schedules.

Authors: Jasna Marinovic, Marko Ljubkovic, Toni Breskovic, Grgo Gunjaca, Ante Obad, Darko Modun, Nada Bilopavlovic, Dimitrios Tsikas, Zeljko Dujic. The aim of this study was to evaluate the changes in vascular/endothelial function following SCUBA diving and to assess the potential difference between two breathing gases: air and nitrox 36 (36% oxygen and 64% nitrogen). Ten divers performed two 3-day diving series (no- decompression dive to 18 m with 47 min bottom time with air and nitrox, respectively), with 2 weeks pause in between. Arterial/endothelial function was assessed using SphygmoCor and X ow-mediated dilation measurements, and the concentration of nitrite before and after diving was determined in venous blood. Production of nitrogen bubbles post-dive was assessed by ultrasonic determination of venous gas bubble grade.

Authors: Megan Brenner, Deborah Stein, Peter Hu, MS, Joseph Kufera, MA; Matthew Wooford, Thomas Scalea. The objective of this paper is to investigate the relationship between oxygenation and short-term outcomes in patients with traumatic brain injury (TBI).

Authors: M. Rozloznik, W. Hemelryck, F. Tilmanns, V. Papadopoulou S. Theunissen, & C. Balestra. The authors of this study focused on the effect of pre-dive hydration after various preconditioning methods on decompression stress in divers. To do so, various anthropological, biochemical, and physiological parameters were collected before and after a single dive to 34m for 20 min divers undergoing no preconditioning (n=10) or pre-dive preconditioning on vibration mat (n=8) or in the sauna (n=7). The hydration level was assessed by specific urine gravity multi-frequency bioelectrical impedance analysis and was correlated to a number of venous gas bubbles as measured by transthoracic echocardiography 35 and 90 minutes after the dive.

Authors: A. Møllerløkken, S. E. Gaustad, M. B. Havnes, C. R. Gutvik, A. Hjelde, U. Wisløff, A. O. Brubakk. In recent studies, the authors have determined the impact of VGE on endothelial function in both laboratory animals and humans. They observed that the damage to the endothelium due to venous gas emboli (VGE) was dose- dependent and that the amount of VGE can be affected both by aerobic exercise and exogenous nitric oxide (NO) intervention before a dive. We observed that NO reduced VGE during decompression and pharmacological blocking of NO production increased VGE formation following a dive. The importance of micro-nuclei for the formation of VGE and how it can be possible to manipulate the formation of VGE are discussed together with the effects of VGE on the organism. In the last part of the review, the authors introduce their thoughts for the future and how the enigma of DCS should be approached.

Authors: Nicolas Vallee, Cédric Meckler, Jean-Jacques Risso, and Jean-Eric Blatteau. Nitrogen supersaturation and bubble formation can occur in the vascular system after diving, leading to death and nervous disorders from decompression sickness (DCS). Bubbles alter the vascular endothelium, activate platelets, and lead to focal ischemia with neurological damage mediated by the mechanosensitive TREK-1 neuronal potassium ion channel that sets pre-and postsynaptic resting membrane potentials. The authors report a neuroprotective effect associated with TREK-1. Mice were subjected to decompression from a simulated 90 msw dive. Of 143 mice that were wild type (WT) for TREK-1, 51.7% showed no DCS, 27.3% failed a grip test, and 21.0% died. Of 88 TREK-1 knockouts (KO), 26.1% showed no DCS, 42.0% failed a grip test, and 31.8% died. Mice that did not express TREK-1 had lower DCS resistance and were more likely to develop neurological symptoms. We conclude that the TREK-1 potassium channel was neuroprotective for DCS.

Authors: Emmanuel Gempp, Jean Morin, Pierre Louge, and Jean Eric Blatteau. A low-grade process of coagulation activation in association with severe neurological decompression sickness (DCS) in divers has been anecdotally observed. The authors aimed to investigate whether measurement of plasma D-dimers and other hemostatic parameters in injured scuba divers were effective as prognostic biomarkers of neurological DCS, and they compared the diagnostic accuracy of a combination of D-dimers test and initial clinical assessment with either one alone.

Authors: Jean-Eric Blatteau, Sandrine Barre, Aurelie Pascual, Olivier Castagna, Jacques H. Abraini, Jean-Jacques Risso, & Nicolas Vallee. Massive bubble formation after diving can lead to decompression sickness (DCS) that can result in central nervous system disorders or even death. Bubbles alter the vascular endothelium and activate blood cells and inflammatory pathways, leading to a systemic pathophysiological process that promotes ischemic damage. Fluoxetine, a well-known antidepressant, is recognized as having anti-inflammatory properties at the systemic level, as well as in the setting of cerebral ischemia. The authors report a beneficial clinical effect associated with fluoxetine in experimental DCS. Ninety- one mice were subjected to a simulated dive at 90 msw for 45 min before rapid decompression.

Authors: Taiki Miyazawa, Masahiro Horiuchi, Daisuke Ichikawa, Andrew W. Subudhi, Jun Sugawara, & Shigehiko Ogoh. Facial cooling (FC) increases cerebral blood flow (CBF) at rest and during exercise; however, the mechanism of this response remains unclear. The purpose of the present study was to test the author's hypothesis that FC causes facial vasoconstriction that diverts skin blood flow (SkBFface) toward the middle cerebral artery (MCA Vmean) at rest and to a greater extent during exercise.

12 - Oxygen breathing or recompression during decompression from nitrox dives with a rebreather: effects on intravascular bubble burden and ramifications for decompression profiles

Authors: Jean-Eric Blatteau, Julien Hugon, Emmanuel Gempp, Olivier Castagna, Christophe Peny, Nicolas Vallee. Preventive measures to reduce the risk of decompression sickness can involve several procedures, such as oxygen- breathing during in-water decompression. Theoretical predictions also suggest that brief recompression periods during decompression could be a method for controlling bubble formation. This study aimed to get more precise information about the effects of different experimental ascent profiles (EAPs) on bubble reduction, using pure oxygen or recompression during decompression for nitrox diving.

Authors: Marko Ljubkovic, Jaksa Zanchi, Toni Breskovic, Jasna Marinovic, Mihajlo Lojpur, and Zeljko Dujic Scuba diving leads to tissue gas supersaturation during ascent and venous gas emboli (VGE) formation. VGE crossover to systemic arteries (arterialization), mainly through the patent foramen ovale, has been implicated in various diving-related pathologies. Since recent research has shown that arterializations frequently occur without cardiac septal defects, this study aimed to investigate the mechanisms responsible for these events.

Authors: R. Arieli & A Marmur It is a long-standing hypothesis that the bubbles which evolve as a result of decompression have their origin in stable gas micronuclei. In a previous study (Arieli and Marmur, 2011), the authors used hydrophilic and monolayer-covered hydrophobic smooth silicon wafers to show that nanobubbles formed on a flat hydrophobic surface may be the gas micronuclei responsible for the bubbles that evolve to cause decompression sickness. On decompression, bubbles appeared only on the hydrophobic wafers. The purpose of the present study was to examine the dynamics of bubble evolution.

8 - Effect of isobaric breathing gas shifts from air to heliox mixtures on resolution of air bubbles in lipid and aqueous tissues of recompressed rats.

Authors: O. Hyldegaard, D. Kerem, Y. Melamed Deep tissue isobaric counterdiffusion that may cause unwanted bubble formation or transient bubble growth has been referred to in theoretical models and demonstrated by intravascular gas formation in animals, when changing inert breathing gas from nitrogen to helium after hyperbaric air breathing. The authors visually followed the in vivo resolution of extravascular air bubbles injected at 101 kPa into nitrogen supersaturated rat tissues: adipose,spinal white matter, skeletal muscle or tail tendon.

Authors: Sema Yilmaz, Kenan Daglioglu, Dincer Yildizdas, Ibrahim Bayram, Derya Gumurdulu, Sait Polat Current treatment modalities and new therapeutic approaches in acute repiratory distress syndrome primarily focused on the resolution of alveolar edema. These treatments include glucocorticoids, surfactants, inhaled nitric oxide, antioxidants and various anti-inflammatory treatments. Unfortunately, to date, none of these pharmacologic treatments has proven to be effective. The authors hypothesized that helium gas might have a beneficial role in the treatment of ARDS.

Authors: Haim Bitterman This small document provides a review of the Hyperbaric oxygen procedures

Authors: Masaki Fujioka, Daisuke Niino, Masahiro Ito, and Yohjiro Matsuoka Patent Foramen ovale is a well know decease that affects many divers and can lead to decompression accidents. This document is the report of an autopsy that revealed a patent foramen ovale of the heart that resulted in the patient dying of paradoxical air embolization of the coronary and cerebral arteries through a patent foramen ovale because of right-to-left shunting.

Authors: Barbara E. Shykoff & Dan E. Warkander Combined effects on respiratory minute ventilation (VE ) and, thus, on end-tidal carbon dioxide partial pressure of breathing resistance and elevated inspired carbon dioxide had not been determined during heavy exercise. In this Institutional Review Board-approved, dry, sea-level study, 12 subjects in each of three phases exercised to exhaustion at 85% peak oxygen uptake while VE and P ET CO2 were measured. Participants inhaled 0%, 1%, 2%, or 3% CO2 in air, or 0% or 2% CO2 in oxygen, with or without breathing resistance, mimicking the U.S. Navy’s MK 16 rebreather underwater breathing apparatus (UBA).

Authors: A.C.P.K. Siriwardhana, R.G.N. Meegama, and G.M.L.P. Aponsu Sound waves propagate in all direction through air and materials due to diffraction effect. Interference of sound signals generated by several devices could create a noisy state which is harmful for the human being at certain instances in which noise intensity level is beyond 90 dB. The system discussed in this research, facilitates to find noise intensity levels at different places simultaneously and further it identifies and point out the places where the noisy state is harmful for human being. Corresponding calculation by the system is mainly done based on the direct source and reflection effects for the selected area.

Authors: J.C. Rostain, C. Lavoute, J.J. Risso, N. Vallee, M. Weiss Nitrogen narcosis occurs in humans at around 0.4 MPa (4 ATA). Hydrogen narcosis occurs between 2.6 and 3.0 MPa. In rats, nitrogen disturbances occur from 1 MPa and a loss of righting reflex around 4 MPa. Neurochemical studies in striatum of rats with nitrogen at 3 MPa with differential pulse voltammetry have demonstrated a decrease in dopamine (DA) release by neurons originated from the substantia nigra pars compacta (SNc). Such a decrease is found also with compressed argon, which is more narcotic than nitrogen and with the anesthetic gas nitrous oxide. Inversely, compressed helium with its very low narcotic potency induces DA increase. Microdialysis studies in the striatum have indicated that nitrogen also induces a decrease of glutamate concentration. receptors activities in SNc.

Authors: Paul Schaffer and Reginald F. Baugh Acute otitis externa is a common condition involving inflammation of the ear canal. The acute form is caused primarily by bacterial infection, with Pseudomonas aeruginosa and Staphylococcus aureus the most common pathogens. Acute otitis externa presents with the rapid onset ofear canal inflammation, resulting in otalgia, itching, canal edema, canal erythema, and otorrhea, and often occurs following swimming or minor trauma from inappropriate cleaning. Tenderness with movement of the tragus or pinna is a classic finding.

Authors: Christian R Gutvik, Tor Arne Johansen, Alf O Brubakk The objective of the work presented in this article is to minimize the time spent decompressing.

Authors: Jacek Kot Clear differences between professional and recreational deep diving are disappearing, at least when taking into account the types of breathing mixtures (oxygen, nitrox, heliox, and trimix) and range of dive parameters (depth and time). Training of recreational deep divers is conducted at depths of 120–150 metres and some divers dive to 180–200 metres using the same diving techniques. Extremely deep recreational divers go to depths of more than 200 metres, at which depths the physical and chemical properties of breathing gases create some physiological restrictions already known from professional deep diving.

Authors: Marc Dalecki, Otmar Bock, and Benjamin Schulze Clear differences between professional and recreational deep diving are disappearing, at least when taking into account the types of breathing mixtures (oxygen, nitrox, heliox, and trimix) and range of dive parameters (depth and time). Training of recreational deep divers is conducted at depths of 120–150 metres and some divers dive to 180–200 metres using the same diving techniques. Extremely deep recreational divers go to depths of more than 200 metres, at which depths the physical and chemical properties of breathing gases create some physiological restrictions already known from professional deep diving.

Authors: Andreas Møllerløkken, Toni Breskovic, Ivan Palada, Zoran Valic, Zeljko Dujic and Alf O Brubakk The aim of this study was to compare the number of venous gas bubbles observed following a short, deep, and a shallow long air dive performed in a hyperbaric chamber, and following actual dives in open water. The authors conclude that diving in water produces significantly more bubbles than dry diving.

18 - Risk factors and clinical outcomes in military divers with neurological decompression sickness: influence of time to recompression

Authors: Jean-Eric Blatteau, Emmanuel Gempp, Pascal Constantin and Pierre Louger This study was conducted to examine the influence of short delays to recompression and other risk factors associated with the development of severe neurological decompression sickness in military divers. Fifty-nine divers, treated for decompression sickness in less than 6 hours, were included respectively. Diving parameters, symptom latency, and recompression delay were analyzed. Clinical symptoms were evaluated for both the acute event and one month later.

Authors: Austin Cope, Joan V Eggert and Erin O’Brien This study describes a case series of 11 patients with retinal artery occlusion treated with hyperbaric oxygen therapy (HBOT) at Intermountain Dixie Regional Medical Center between 2005 and 2009. the authors then combined data from our case series with data from two other case series to report a combined total of 51 patients. Eight of 11 patients achieved improved visual acuity. Analysis of the combined case series showed that 74% of patients treated with HBOT had an improvement in visual acuity, with 53% improving by two lines or more on a modified Snellen valu

Authors: S Lesley Blogg and Mikael Gennser Audio Doppler ultrasound and echocardiographic techniques are useful tools for investigating the formation of inert gas bubbles after hyperbaric exposure and can help to assess the risk of decompression sickness occurrence. This review summarises comprehensive Doppler data collected over 15 years across many dive profiles and then assesses the effectiveness of measurements made between 30 and 60 minutes (min) post-dive (commonly measured time points made in recent studies) in characterising the evolution and peak of venous gas emboli (VGE).

Authors: Si Jack Chong, Meng Kwan Tan, Weihao Liang, Soo Joang Kim and Chai Rick Soh Both negative pressure wound therapy (NPWT) and hyperbaric oxygen therapy (HBOT) are useful modalities in the treatment of problematic wounds. However, none of the commercially available portable negative-pressure devices has been certified safe for use in a recompression chamber. Thus, the NPWT device is removed while the patient undergoes HBOT. The purpose of this study is to demonstrate that wound negative pressure can be effectively and safely maintained during HBOT.

Authors: Christian Mehl, Frank Heblich, Rudolf Lenz, Klaus Ludwig and Matthias Kern The purpose of this in-vitro study was to determine whether there is a correlation between a hyperbaric environment increased oxygen partial pressure, and the corrosion of dental alloys used for dental restorations in divers. Samples of three commercially available dental alloys were tested in the DIN EN ISO 1562 static immersion test, and the amount of dissolved ions was measured using atomic absorption spectrometry.

Authors: Denis A. Tolstun, Khachik K. Muradian, Vladislav V. Bezrukov Interest in hypercapnia and its practical applications has significantly grown. An analysis of literary data shows a wide range of systemic and local applications. Due to its powerful effect on blood circulation, vascular elasticity, activation of angiogenesis, and inhibition of pro- inflammatory factors, hypercapnia is already used in dermatology, phlebology, and therapy. Wide opportunities open up for use in neurology, given the powerful neuroprotective effect of carbon dioxide, which not only increases tolerance to ischemia, preventing the development of diseases, but can also become a tool for the treatment of stroke and heart attack.

Authors: N.A.M. Schellart , & W. Sterk Decompression tables indicate that a repetitive dive to the same depth as the first dive should be shortened to obtain the same probability of occurrence of decompression sickness (pDCS). Repetition protocols are based on small numbers, a reason for re-examination. Since venous gas embolism (VGE) and pDCS are related, one would expect a higher bubble grade (BG) of VGE after the repetitive dive without reducing bottom time.

Authors: Ingrid Eftedal, Arve Jørgensen, Ragnhild Røsbjørgen, Arnar Flatberg, and Alf O. Brubakk The aim of this study was to analyze genetic reactions that may be involved in acute changes in vascular function in divers. Rats were exposed to 709 kPa of hyperbaric air (149 kPa PO2 ) for 50 minutes, followed by post-dive monitoring of vascular bubble formation and full genome microarray analysis of the aorta from diving rats and unexposed controls.

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42 - Lower risk of decompression sickness after recommendation of conservative decompression practices in divers with and without vascular right-to-left shunt

Authors: Christoph Klingmann, Nils Rathmann, Daniel Hausmann, Thomas Bruckner and Rolf Kern Divers with a history of decompression sickness (DCS) who adopted more conservative diving profiles (CDP) showed a significant reduction in the recurrence of DCS, regardless of the presence or size of a right-to-left shunt. This study involved 27 divers who, after experiencing DCS, changed their diving practices upon recommendation. They performed a total of 9,236 dives post- recommendation with only four instances of DCS, compared to 34 instances during 17,851 pre- recommendation dives. This suggests that conservative diving effectively lowers the risk of subsequent DCS.

43 - The Use of Deep Tables in the Treatment of Decompression Illness: The Hyperbaric Technicians and Nurses Association 2011 Workshop

Authors: Michael H Bennett, Simon J Mitchell, Derelle Young and David King In August 2011, the South Pacific Underwater Medicine Society and the Hyperbaric Technicians and Nurses Association held a one-day workshop to discuss the use of deep recompression treatment tables for decompression illness in Australia and New Zealand. The goal was to create consensus statements to guide regional practices, focusing on 405 kPa (30 msw) depth tables with helium- oxygen mixes, covering indications, staffing, and technical requirements. This report summarizes the evidence and consensus statements from the workshop.

Authors: Mayuree Sampanthavivat, Wararat Singkhwa, Thanasawat Chaiyakul, Sangdaw Karoonyawanich and Haruthai Ajpru This study evaluated the effectiveness of hyperbaric oxygen therapy (HBOT) on 60 Thai children with autism aged three to nine years. Participants underwent 20 one- hour sessions of either HBOT at 153 kPa or sham air at 116 kPa. The results indicated significant behavioral improvements in both groups, but no significant differences were found between the HBOT and sham groups. Overall, no definitive clinical benefit from HBOT was observed, although both treatments were safe and well-tolerated.

Authors: Nada Bilopavlovic, Jasna Marinovic, Marko Ljubkovic, Ante Obad , Jaksa Zanchi, Neal W. Pollock, Petar Denoble, Zeljko Dujic The study investigated changes in markers of endothelial and brain damage after repetitive SCUBA diving, while also assessing venous gas bubble production and arterialization. Despite significant bubble production and occasional arterialization, no changes were observed in the levels of endothelin-1 and neuron-specific enolase. However, the levels of the S100 calcium-binding protein B (S100B) were significantly elevated after the 18-meter and control dives, suggesting its release from skeletal muscles rather than indicating brain or endothelial damage.

Authors: S.K. Hooker et al. The study reviews the evidence of gas bubbles in the tissues of marine mammals and discusses theories of gas loading and bubble formation. It suggests that diving mammals adjust their physiological responses to various stressors and proposes a shift in focus from minimizing to managing N2 load. This opens up multiple research avenues, from studying the effects of gas bubbles at various biological levels to examining their relationship with diving behavior. Technological advancements in imaging and remote instrumentation are expected to further enhance this field of study. .

Authors: I. A. Brownlee, A. C.Fairclough, A. C. Hall, and J. R. Paxman This study intends to provide a comprehensive review of the current evidence regarding the consumption of seaweed and seaweed isolates, their potential health benefits, and their applications in food products. Gaps in current knowledge and suggested future research strategies to maximize the potential uses of seaweed in food products are also highlighted.

Authors: R. Arieli, A. Marmur This document presents and supports a scientific hypothesis regarding the origin of bubbles that cause decompression sickness. The authors propose that nanobubbles forming on hydrophobic surfaces submerged in water may serve as gas micronuclei responsible for bubble evolution during decompression. To support their hypothesis, they describe an experiment involving hydrophilic and hydrophobic silicon wafers, showing that bubbles evolved only on hydrophobic surfaces after decompression.

Authors: Pierre-Emmanuel Rautou, Anne-Clemence Vion, Nicolas Amabile, Gilles Chironi, Alain Simon, Alain Tedgui, Chantal M. Boulanger This document explains the role and impact of membrane-shed submicron microparticles (MPs) in the context of atherothrombotic diseases and atherosclerosis. That includes the origin and release of MPs during cell activation or apoptosis, the potential of MPs as biomarkers for vascular injury and predictors of cardiovascular events, the accumulation and effects of MPs in atherosclerotic lesions, and the mechanisms by which MPs contribute to the development, progression, and complications of atherosclerosis.

Authors: Jian-Guo Wang, Julie C. Williams, Beckley K. Davis, Ken Jacobson, Claire M. Doerschuk, Jenny P.-Y. Ting, & Nigel Mackman This document presents scientific research findings on how monocytic microparticles (MPs) activate endothelial cells, particularly in the context of inflammation and disease. The study investigates the mechanisms by which MPs from lipopolysaccharide (LPS)-treated monocytic cells induce endothelial cell activation, highlighting the role of IL-1 Beta and inflammasome components in this process. The research aims to elucidate the pathways involved and the potential implications for inflammatory diseases.

Authors: Anni Vanhatalo, Jonathan Fulford , Stephen J. Bailey, James R. Blackwell, Paul G. Winyard, & Andrew M. Jones This text conveys the findings of a study that demonstrates the benefits of dietary nitrate supplementation in improving muscle efficiency and exercise tolerance under conditions of reduced oxygen availability (hypoxia). It aims to inform readers that nitrate can be converted in the body to nitrite and nitric oxide, which help reduce muscle fatigue and enhance oxygen delivery to muscles. It suggests potential applications of dietary nitrate for improving exercise performance at high altitudes and in medical conditions that impair oxygen delivery to muscles.

Authors: Ming Yang, Tatyana N. Milovanova, Marina Bogush, Günalp Uzun, Veena M. Bhopale, and Stephen R. Thom This study investigates how decompression stress leads to an increase in the number and size of annexin V-coated microparticles derived from various cell types. The research explores the hypothesis that these changes are due to inert gas bubbles and can be mitigated by hydrostatic pressure. The study further examines the proinflammatory potential of these particles and their role in vascular damage, demonstrating that particles from decompressed mice cause significant inflammatory and vascular changes when injected into mice.

Authors: Marianne B. Havnes, Catrine Ahlen, Alf O. Brubakk, and Ole-Jan Iversen. This document discusses the findings of a scientific study that investigated the production of autoantibodies against Heat Shock Protein 60 (HSP60) in rats immunized with Pseudomonas aeruginosa and the influence of diving on the levels of these autoantibodies. The study aims to understand the relationship between P. aeruginosa infections, common in saturation divers and cystic fibrosis patients, and the immune response involving HSP60. The results indicate that immunization with P. aeruginosa increases autoantibodies against HSP60, but this increase is not observed in rats that were both immunized and subjected to simulated diving conditions.

Authors: Lisette B. Soegaard, Marie N. Hansen, Cornelis van Elk, Jesper Brahm, and Frank B. Jensen. The study of sea mammals is a path to better understanding physiological phenomena linked to diving. This document explains a scientific investigation into the physiological traits of harbor porpoises that are adaptive for their diving behavior. The study focuses on various aspects such as blood oxygen-transporting properties, buffer characteristics, chloride transport via the erythrocyte anion exchanger (AE1), circulating nitric oxide metabolites, and hemoglobin nitrite reduction.

Authors: Helene N. David, Benoıt Haelewyn, Mickael Degoulet, Denis G. Colomb, , Jean-Jacques Risso, Jacques H. Abraini Argon is known for its high Narcosis properties and is not used in diving breathing mixes for these reasons. However, it can have other applications. This study investigates whether this gas can provide neuroprotection after excitotoxic or ischemic events. The results indicate that while argon has beneficial effects at the cortical level, it may increase subcortical brain damage if administered post-ischemia. The authors suggest that argon should be administered during ischemia, before reperfusion, to maximize its neuroprotective benefits and minimize potential harm.

Authors: Sara R. Zwart, J. Milburn Jessup, Jiuping Ji, Scott M. Smith This study investigated the effects of an oxygen-rich environment on oxidative damage, iron stores, and vitamin status, particularly folate, in humans. It involved participants undergoing a saturation dive in a hyperoxic environment, and it aimed to assess the biochemical markers of iron status, oxidative damage, and vitamin status before, during, and after the dive. The results indicated that increased body iron stores and oxidative stress were associated with decreased folate status and an elevated DNA damage repair response. The study suggests that folate requirements may be higher in such environments.

Authors: Stephen R. Thom, Tatyana N. Milovanova, Marina Bogush, Veena M. Bhopale, Ming Yang, Kim Bushmann, Neal W. Pollock, Marko Ljubkovic, Petar Denoble, and Zeljko Dujic This study evaluated the presence of annexin V-positive microparticles (MPs) and neutrophil activation in humans following decompression from open-water SCUBA diving. It was hypothesized that these changes are related to intravascular bubble formation. The document details the methodology, including the profile of the dives, the timing of blood sample collection, and the techniques used to quantify intravascular bubbles and assess neutrophil activation. It also summarizes the key findings, such as the increase in MPs, neutrophil activation, and the interactions between platelets and neutrophils.

Authors: Ivan. T. Demchenko, Alexander N. Moskvin, Alexander I. Krivchenko, Claude A. Piantadosi, & Barry W. Allen This study evaluated the presence of annexin V-positive microparticles (MPs) and neutrophil activation in humans following decompression from open-water SCUBA diving. It was hypothesized that these changes are related to intravascular bubble formation. The document details the methodology, including the profile of the dives, the timing of blood sample collection, and the techniques used to quantify intravascular bubbles and assess neutrophil activation. It also summarizes the key findings, such as the increase in MPs, neutrophil activation, and the interactions between platelets and neutrophil.

36 - Application of Multifrequency bioelectrical Impedance analysis Method for the Detection of Dehydration status in professional Divers

Authors: Sermin Sengun, Atilla Uslu, Salih Aydin This study investigates the level and source of dehydration in divers who use heliox. Using multifrequency bioelectrical impedance analysis (MF-BIA), it aims to determine whether the dehydration is intracellular, extracellular, or both. The text outlines the study's background, objective, methodology, results, and conclusions.

Authors: Assim A. Alfadda, and Reem M. Sallam This document provides an overview and summary of the roles of reactive oxygen species (ROS) in health and disease. It aims to highlight the biological effects of ROS, their production, and metabolism in cellular organelles like the endoplasmic reticulum and mitochondria, as well as recent research findings that have advanced the understanding of ROS in redox regulation. It also offers a brief perspective on research to enhance the knowledge of ROS actions in various health and disease conditions.

Authors: Yara Bernaldo de Quirós, Oscar González-Diaz, Manuel Arbelo, Eva Sierra, Simona Sacchini, Antonio Fernández As previously mentioned, studies on sea mammals help to understand phenomena linked to diving. This document presents the findings from a survey of gas embolic lesions in stranded cetaceans, particularly in relation to military sonar. It aims to analyze the prevalence, amount, distribution, and composition of gas bubbles in marine mammal tissues, taking into account species-specific variability and the impact of decomposition. It also provides recommendations for necropsy procedures to minimize the masking effects of putrefaction gases and highlights the significance of gas bubble amounts in pathological assessments.

Authors: Manav V Vyas, Amit X Garg, Arthur V Iansavichus, John Costella, Allan Donner, Lars E Laugsand, Imre Janszky, Marko Mrkobrada, Grace Parraga, Daniel G Hackam This study is a systematic review and meta-analysis of observational studies to determine the association between shift work and major vascular events, such as myocardial infarction, ischemic stroke, and coronary events. It outlines the methodology used for data collection and analysis, the results of the studies reviewed, and the implications of these findings for public policy and occupational medicine.

Authors: Mikulas Chavko, Usmah Kawoos, Saleena Adeeb, Jason Lankasky, Charles R. Auker, Richard M. McCarron The authors of this study investigate the protective effects of intermittent hyperbaric oxygen (HBO2) exposure against the central nervous system (CNS) and pulmonary toxicity. The study aims to optimize the duration of HBO2 cycles to enhance protective outcomes. It describes the methods used, including the exposure of rats to different HBO2 cycles and the assessment of lung inflammation and respiratory changes. The results indicate that intermittent HBO2 exposure is more effective in reducing lung inflammation and respiratory changes compared to continuous exposure.

Authors: Christopher J. Morris; Jessica N. Yang; and Frank A. J. L. Scheer This paper intends to convey scientific findings regarding the relationship between the circadian timing system, shift work, and the increased risk of cardiovascular and metabolic diseases. The research explains how the body's internal clock influences cardiovascular risk markers and how misalignment between the circadian rhythm and external factors, such as shift work, can lead to adverse health outcomes.

Authors: Earl S Ford, & Carl J Caspersen This study summarizes research on the relationship between sedentary behavior, specifically screen time and sitting time, and the risk of cardiovascular disease (CVD). Based on prospective studies that primarily used self- reported data, it highlights the association between increased sedentary time and higher risks of both fatal and non-fatal CVD. Additionally, it suggests that future research using more objective measures of sedentary behavior could provide more accurate risk assessments and inform public health guidelines and interventions to reduce sedentary behavior.