scientific-2005

Scientific papers 2005

02 - Optimization of oxygen tolerance extension in rats by intermittent exposure - Published by the American Physiological society.

Authors: C. J. Lambertsen, J. M. Clarck, A. B. Troxel Optimization of oxygen tolerance extension by intermittent exposure was studied in groups of 20 rats exposed to systematically varied patterns of alternating oxygen and normoxic breathing periods at 4.0, 2.0, and 1.5 ATA. Oxygen periods of 20, 60, and 120 min were alternated with normoxic intervals that provided oxygen- to-normoxia ratios of 4:1, 2:1, 1:1, and 1:3.

This paper gives a detailed history of the deep-diving operations and researches undertaken by COMEX. These operations and studies resulted in the creation of tables such as those used by the French ministry of labour and also the NORMAM 15/DPC procedures in Brazil.

01 - Exercise during a 3-min decompression stop reduces postdive venous gas bubbles - Published by the American College of Sport Medicine (author-provided)

Authors: Z. Dujic, I. Palada, A. Obad, D. Duplancic, D. Bakovic, & Z. Valic. Decompression sickness is initiated by the formation of gas bubbles in tissue and blood if the divers return to surface pressure too fast. The effect of exercise before, during, and after dive on bubble formation is still controversial. The team reported previously that strenuous aerobic exercise 24 h before simulated dive ameliorates venous bubble formation. The objective of this field study was to evaluate whether mild, continuous exercise during decompression has a similar impact.

33 - Aerobic exercise 2 hours before a dive to 30 msw decreases bubble formation after decompression - Published by Aviation Space and environmental medicine

Authors: Jean-Eric Blatteau, Emmanuel Gempp, Franc¸ois-Michel Galland, Jean-Michel Pontier, Jean-Marie Sainty, and Claude Robinet. A single bout of aerobic exercise 24 h before a dive significantly reduces the formation of circulating venous gas emboli (VGE) on decompression. The purpose of this investigation was to determine the effect of aerobic exercise 2 h before a dive.

32 - Two consecutive five-day weeks of daily four-hour dives with oxygen partial pressure 1.4 atm - Published by the US Navy Experimental Diving Unit

Author: B. Shykoff Sixteen U.S. Navy divers began a series of 4-hour dives at a PO2 of 1.4 atm daily for two consecutive five-day weeks. Nine divers were able to finish; all withdrawals were for nonpulmonary reasons. Divers rested on the bottom of a 15-foot freshwater pool and breathe humidified 100% oxygen open circuit from MK 20 full face masks. Flow- volume curves and diffusing capacity were measured at baseline, daily during diving, and after the series. Symptoms and changes in pulmonary function values were used to measure pulmonary oxygen toxicity, and the results were compared to earlier series of similar four- hour dives.

08 - Treatment of Decompression Sickness in Swine with Intravenous Perfluorocarbon Emulsion - Published by Aviation Space and Environmental Medicine (Author-released).

Authors: David M. Dromsky, Bruce D. Spiess, Andreas Fahlman. The authors of this paper examined an adjunctive treatment for severe decompression sickness (DCS) to be used when hyperbaric treatment is delayed or unavailable. It is based on the hypothesis that intravenous perfluorocarbon (PFC) emulsion combined with 100% inspired O2 would improve severe DCS outcomes.

Authors: A. O. Brubakk, D. Duplancic, Z. Valic, I. Palada, A. Obad, D. Bakovic, U. Wisloff, and Z. Dujic. During and after decompression from dives, gas bubbles are regularly observed in the right ventricular outflow tract. Several studies have documented that these bubbles can lead to endothelial dysfunction in the pulmonary artery, but no data exist on the effect of diving on arterial endothelial function. The present study investigated if diving or oxygen breathing would influence endothelial arterial function in man.

25 - Allometric scaling of the maximum metabolic rate of mammals: Oxygen transport from the lungs to the heart is a limiting step - Published by BioMed central.

Author: Page R Painter The maximum metabolic rate (MMR) of mammals is approximately proportional to M0.9, where M is the mammal's body weight. Therefore, MMR increases with body weight faster than the basal metabolic rate (BMR), which is approximately proportional to M0.7. MMR is strongly associated with the capacity of the cardiovascular system to deliver blood to capillaries in the systemic circulation, but the properties of this vascular system have not produced an explanation for the scaling of MMR.

Author: R. Kłos Research on the validation of decompression tables is one of the common subject areas of the cooperation undertaken between the DRDC Toronto, Canada, and The Naval University of Gdynia, Poland. A survey of diving technologies has been conducted for Scientific Research and the Polish Navy. Among the most critical problems discussed have been various aspects of decompression safety. The following is a study to standardize and unify validation procedures for decompression in the Polish Navy.

13 - Robert Boyle’s landmark book of 1660 with the first experiments on rarified air - Published by the Journal of applied physiology (Author-released).

Author: John B. West In 1660, Robert Boyle (1627–1691) published his landmark book New Experiments Physico-Mechanicall, Touching the Spring of the Air, and its Effects in which he described the first controlled experiments of the effects of reducing the pressure of the air. Critical to this work was the development of an air pump by Boyle with Robert Hooke (1635–1703). For the first time, it was possible to observe physical and physiological processes at both normal and reduced barometric pressures.

17 - Late Treatment of Severe Brain Injury with Hyperbaric Oxygenation - Published by the Journal of American Physicians and Surgeons

Authors: Richard A. Neubauer, Virginia Neubauer, & Franz Gerstenbrand Controlled studies have demonstrated safety and efficacy of hyperbaric oxygenation therapy (HBOT) in the treatment of anoxic, traumatic, ischemic, or thrombotic brain injury. Clinical improvements were correlated with increased perfusion and metabolism, with reactivation of idling neurons demonstrated by sequential single photon emission computerized tomographic (SPECT) scanning.

27 - Humidity influences exercise capacity in subjects with exercise- induced bronchoconstriction (EIB) - Published by Respiratory Medicine - Elsevier (author-released)

Authors: T. Stensrud, S. Berntsen, K.-H. Carlsen Exercise-induced bronchoconstriction (EIB) increases in cold and dry air and decreases in humid air in subjects with asthma. Few reports have reported on the effect of humid environment upon exercise capacity in subjects with EIB. The primary aim of the present study was to examine the effect of changing the humidity of the environmental air upon exercise capacity measured by peak oxygen uptake, peak ventilation and peak running speed and secondarily to assess the influence of environmental humidity upon EIB in subjects suffering from EIB.

Author: R.W. Hamilton This paper attempts to show how a variety of decompression tables, including some that are not “in the book,” can lead to improved decompression capability. Such tables are often available from diving training organizations. They can also be obtained from decompression specialists, and in some cases, can be developed by the using organization. Many innovative table collections are available from specific sources.

31 - Energetic costs of diving and thermal status in European (Phalacrocorax aristotelis) - Published by the Universite de Bretagne Occidentale

Authors: Manfred R. Enstipp, David Grémillet, and Svein- Håkon Lorentsen This paper attempts to show how a variety of decompression tables, including some that are not “in the book,” can lead to improved decompression capability. Such tables are often available from diving training organizations. They can be obtained from decompression specialists, and in some cases, can be developed by the using organization. Many innovative table collections are available from specific sources.

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16 - Altitude Decompression Sickness Susceptibility: Influence of Anthropometric and Physiologic Variables - Published by Aviation Space and Environmental Medicine

Authors: James T. Webb, Andrew A. Pilmanis, ULF I. Balldin, Joseph R. Fisher The US Air Force studied altitude decompression sickness (DCS) using a database with data from 2980 exposures. The study involved 240 subjects and found DCS incidence rates ranging from 5 to 95%. Researchers assessed susceptibility by examining factors such as height, weight, age, body fat percentage, and aerobic capacity. Findings showed that DCS incidence was 46.5% during 1,879 subject exposures. A correlation was found between lower aerobic capacity and greater weight, higher susceptibility to DCS, these factors only explain less than 13% of the variation in risk.

05 - Weber's syndrome and sixth nerve palsy secondary to decompression illness: A case report - Published by the Undersea & Hyperbaric medical Society

Authors: W Padilla, H B Newton, S Barbosa This article documents the first case of Weber's syndrome due to decompression illness in a 55-year-old recreational scuba diver with a history of a pulmonary cyst. Weber's syndrome involves oculomotor nerve palsy and contralateral hemiparesis. Symptoms appeared after a deep dive exceeding no-decompression limits. The injury mechanism may involve air gas embolism and decompression sickness, with pre-existing pulmonary cysts potentially increasing the risk of complications.

06 - Sedentary Behavior, Physical Activity, and the Metabolic Syndrome among U.S. Adults - Published by Obesity Reseache - Wiley online library (Author-released)

Authors: Earl S. Ford, Harold W. Kohl, Ali H. Mokdad, & Umed A. Ajani This study analyzed 1,626 adults to examine the link between physical activity, sedentary behavior, and metabolic syndrome. Results indicated that those not engaging in moderate or vigorous physical activity had nearly double the odds of metabolic syndrome compared to those with at least 150 minutes of such activity weekly. The study concludes that reducing sedentary behavior and increasing physical activity could significantly lower the prevalence of metabolic syndrome among adults.

07 - Risks for All-Cause Mortality, Cardiovascular Disease, and Diabetes Associated With the Metabolic Syndrome - Published by the American Diabete Association (Author-released)

Author: Earl S. Ford In recent years, major organizations have endorsed the concept of metabolic syndrome and created working definitions for it. This study aims to summarize the relative risk estimates for all-cause mortality, cardiovascular disease, and diabetes, as reported in prospective studies of general population samples, using definitions of metabolic syndrome developed by the National Cholesterol Education Program (NCEP) and the World Health Organization (WHO).

09 - Exercise-induced intrapulmonary shunting of venous gas emboli does not occur after open-sea diving - Published by the Journal of Applied Physiology (Author-released)

Authors: Zeljko Dujic, Ivan Palada, Ante Obad, Darko Duplancic, Alf O. Brubakk, and Zoran Valic The study investigates whether intrapulmonary shunts, which can cause neurological damage due to venous gas emboli, occur after strenuous exercise following a dive. Eleven healthy military divers performed a dive to 30 meters and mild exercise during the dive, followed by more intense exercise 40 minutes after surfacing. The results showed significant venous bubbles but no intrapulmonary shunting or delayed-onset decompression sickness. The authors suggest that short, strenuous exercise after diving may be safe, but further research with more participants is needed to confirm this.

12 - Molecular mechanisms of vascular adaptations to exercise. Physical activity as an effective antioxidant therapy? - Published by Cardiovascular Research - Elsevier (Author-released)

Authors: JGeorg Kojda, Rainer Hambrecht IRegular physical activity reduces cardiovascular disease risk. Exercise promotes vascular remodeling, improving blood flow. Physical forces activate mechanisms in cells involving integrins and RhoA (regulating various cellular processes). Exercise also enhances eNOS expression and phosphorylation, providing vasoprotective effects. This process is regulated by factors such as angiogenesis, arteriogenesis, and antioxidative effects. As a conclusion, exercise is an effective antioxidant and antiatherogenic therapy.

14 - A Comparison of Three Different Methods to Evaluate Endothelium-Dependent Vasodilation in the Elderly The Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) Study - Published by the AHA/ASA Journals (Author-released)

Authors: Lars Lind, Nilla Fors, Jan Hall, Kerstin Marttala, Anna Stenborg This study evaluated the feasibility and usefulness of three different techniques for assessing endothelium-dependent vasodilation in the peripheral circulation within a large- scale, elderly population-based setting. Conducted as part of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study, the findings revealed that all three techniques were feasible for use in a general elderly population.

26 - Fate of manganese associated with the inhalation of welding fumes: Potential neurological effects - Published by the Neurotoxicology Journal - Elsevier (author-released)

Authors: James M. Antonini, Annette B. Santamaria, Neil T. Jenkins, Elisa Albini, Roberto Lucchini Occupational health officials are concerned about the neurological effects of manganese in welding fumes. The behavior of manganese in welding particles after inhalation is unclear, and its various oxidation states and solubility may affect biological responses. Therefore, comprehensive epidemiological studies on welders' exposure are needed.

Authors: Stephen R. Thom, Veena M. Bhopale, Omaida C. Velazquez, Lee J. Goldstein, Lynne H. Thom, and Donald G. Buerk The study suggests that hyperbaric oxygen exposure mobilizes stem cells through a nitric oxide mechanism. In mice, HBO2 raised stem cell factor by 50% and increased cells expressing stem cell markers. Bone marrow NO concentration rose significantly with HBO2. NO synthase inhibitors prevented stem cell mobilization in mice. Study concludes that HBO2 stimulates NO synthesis to mobilize stem cells.

30 - Direct ascent from air and N2-O2 saturation dives in humans: DCS risk and evidence of a threshold - Published by the Undersea & Hyperbaric medical Society (Author-released).

Authors: H.D. Van Liew and E.T. Flynn This document presents research findings on the risk of decompression sickness (DCS) associated with direct ascents from saturation dives in humans by analyzing experimental data to identify a threshold depth at which the risk of DCS increases significantly. It compares two models for predicting DCS risk, highlighting that a model incorporating a threshold provides more accurate predictions than one without. The study also recommends using the threshold model in specific scenarios, such as submarine rescues and discusses the implications for deeper dives where human data is lacking.

34 - The Effects of Exhaustive Exercise on Thermoregulatory Fatigue During Cold Exposure - Published by DCIEM / DRDC (Defence Research and Development Canada)

Authors: John W. Castellani, Andrew J. Young, Michael N. Sawka The authors of this paper present the findings of experiments that investigated the effects of acute and chronic exertional fatigue on thermoregulatory responses during cold exposure. They explain the methodology, results, and conclusions of these studies, highlighting how prior physical exercise can influence heat loss and core temperature decline when individuals are subsequently exposed to cold conditions.

03 - Counterdiffusion Diving: Using Isobaric Mix Switching To Reduce Decompression Time - Published by the American Academy of Underwater Science

Author: Glenn H. Taylor Switching a diver’s breathing mix from heliox to nitrox at a specified time during the bottom portion of the dive can reduce the total stop time for long dives in the deep nitrox range. Isobaric Mix Switching with oxygen decompression reduced calculated total stop times by an average of 38% compared to calculated total stop times using nitrox with oxygen decompression. The optimal mix-switch time was determined empirically using mixed-gas decompression software.

04 - The Risk of Decompression Sickness (DCS) is Influenced by Dive Conditions - Published by the American academy of underwater science (Autohor-released)

Author: Richard D. Vann, Petar J. Denoble, Donna M. Uguccioni, Neal W. Pollock, , John J. Freiberger, Carl F. Pieper, W.A. Gerth, and Robert Forbes This report examined DCS risk in warm-water, cold-water, and Navy dives, comparing predicted risks with actual cases. Mean observed incidences were reported. Predictions were adjusted. Conclusions include the usefulness of probabilistic models for estimating risk and noting that dive conditions also significantly impact risk.

Authors: Carl Edmonds, Stephanie McInnes and Michael Bennett A workshop in 1999 found that some previous diving rules to prevent decompression sickness (DCS) were unnecessary under specific conditions. It suggested that diving order, whether deep first or last, did not matter for certain dives. The final recommendation allowed reverse dive profiles (RDPs) for dives under 40 meters and with depth differences under 12 meters. According to the authors, this recommendation needs careful evaluation as RDPs may be more dangerous than forward dive profiles (FDPs). Current advice to use FDPs should continue.

20 - Reverse dive profiles: the making of a myth - Published by the South Pacific Underwater Medicine Society (SPUMS)

Author: Paul J Fenner Jellyfish envenomation is far more common around the world than is realised. Although the vast majority of jellyfish stings are somewhat benign, there are some venomous species that regularly account for both deaths and severe morbidity in humans. Venomous jellyfish occur mainly in tropical and subtropical oceans. This article discusses relevant information on their appearance, distribution, and symptoms of envenomation, and firstaid and medical treatments for their stings.

21 - Venomous Jellyfish of the word - Published by the South Pacific Underwater Medicine Society (SPUMS)

22 - The rate of decompression sickness in scientific diving at the Australian Institute of Marine Science (Townsville) 1996 to 2001 - Published by the South Pacific Underwater Medicine Society (SPUMS)

Authors: Anthony Carter, Reinhold Muller and Angus Thompson This study discusses the rate of decompression sickness (DCS) in scientific diving, following the Canadian Defence and Civil Institute of Environmental Medicine (DCIEM) decompression tables, and how the AS/NZS Scientific Diving Standard (AS/NZS 2299. 2:2002) might affect dive profiles at the Australian Institute of Marine Science (AIMS) in Townsville. Data from October 1996 to December 2001 was collected, showing low DCS rates in multi-day dives, and suggesting that AS/NZS limits may need modification for scientific diving.

23 - The clinical incidence of central nervous system oxygen toxicity at 284 kPa (2.8 ATA) - Published by the South Pacific Underwater Medicine Society (SPUMS)

Authors: David Wilkinson, Sally Wright and Steven Goble Central nervous system (CNS) oxygen toxicity is a known issue with hyperbaric oxygen treatment (HBOT), often leading to seizures. The frequency of this complication has been reported differently. A review of data from the Royal Adelaide Hospital from 1986 to 2003 found symptoms of CNS oxygen toxicity and seizure occurrences in patients treated at 284 kPa (2. 8 ATA). There is a higher seizure risk in emergency treatments than in non-emergency ones, particularly for female divers and during the initial treatment for decompression sickness (DCS)

24 - The international safety record for scientific diving - Published by the South Pacific Underwater Medicine Society (SPUMS)

Author: Martin Sayer This study includes two papers reviewing the safety records of scientific diving programs in Australia and the United States. A previous review of a UK institution's diving operations is also included. This commentary will compare the safety trends of the three studies to evaluate the relative risk levels in the scientific diving sector.

10 - World Health organization - Handbook for good clinical research (GCP) - Published by the World Health Organization

Author: World Health organization Clinical research is crucial for establishing the safety and effectiveness of health and medical products. Known knowledge is based on randomized controlled trials, which form the foundation for evidence-based medicine. This handbook, based on WHO's guidelines for Good Clinical Research Practice (GCP), assists national regulatory authorities, sponsors, investigators, and ethics committees in implementing GCP for industry- sponsored, government-sponsored, institution- sponsored, or investor-initiated clinical research.

28 - Comparison between two methods for estimating pneumothorax size from chest X-rays - Published by Respiratory Medicine - Elsevier (Author-released)

Author: Anne-Maree Kelly, Daragh Weldon, Anna Y.L. Tsang, Colin A. Graham This study compared the Rhea inter-pleural distances method and the CT-derived Collins method for estimating the size of spontaneous pneumothoraces in adult patients. 156 X-rays were taken from 57 patients, with 82% being male and a median age of 22 years. The Collins method estimated larger pneumothoraces, with an average difference of 4%. The agreement was close for small pneumothoraces but deteriorated with larger sizes. The Rhea method is acceptable for smaller pneumothoraces but may significantly underestimate larger sizes.