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altitude chamber

Yaru Li, Peng Yu, Shi-Yang Chang, Qiong Wu, Panpan Yu, Congcong Xie, Wenyue Wu, Baolu Zhao, Guofen Gao, Yan-Zhong Chang
Disruption of iron homeostasis in brain has been found to be closely involved in several neurodegenerative diseases. Recent studies have reported that appropriate intermittent hypobaric hypoxia played a protective role in brain injury caused by acute hypoxia. However, the mechanisms of this protective effect have not been fully understood. In this study, Sprague-Dawley rat models were developed by hypobaric hypoxia treatment in an altitude chamber, and the iron level and iron related protein levels were determined in rat brain after four weeks of treatment...
December 6, 2016: Journal of Cellular Biochemistry
Daniel A Nation, Mark W Bondi, Ellis Gayles, Dean C Delis
OBJECTIVES: Cognitive dysfunction from high altitude exposure is a major cause of civilian and military air disasters. Pilot training improves recognition of the early symptoms of altitude exposure so that countermeasures may be taken before loss of consciousness. Little is known regarding the nature of cognitive impairments manifesting within this critical window when life-saving measures may still be taken. Prior studies evaluating cognition during high altitude simulation have predominantly focused on measures of reaction time and other basic attention or motor processes...
December 7, 2016: Journal of the International Neuropsychological Society: JINS
Anna Hartman-Ksycińska, Jolanta Kluz-Zawadzka, Bogumił Lewandowski
High-altitude illness is a result of prolonged high-altitude exposure of unacclimatized individuals. The illness is seen in the form of acute mountain sickness (AMS) which if not treated leads to potentially life-threatening high altitude pulmonary oedema and high-altitude cerebral oedema. Medical problems are caused by hypobaric hypoxia stimulating hypoxia-inducible factor (HIF) release. As a result, the central nervous system, circulation and respiratory system function impairment occurs. The most important factor in AMS treatment is acclimatization, withdrawing further ascent and rest or beginning to descent; oxygen supplementation, and pharmacological intervention, and, if available, a portable hyperbaric chamber...
2016: Przegla̧d Epidemiologiczny
Joe X Zhang, Jacob R Berry, Devin P Beckstrand
BACKGROUND: Arterial gas embolism (AGE) is a rare condition in the flying community most often only ever seen in flight while operating at high altitude or incidents involving hypobaric chambers. This article describes a severe case of AGE that occurred in a pilot of a fourth generation fighter aircraft at ground level. The environmental control system (ECS) malfunctioned, causing an overpressurized cockpit and a subsequent explosive decompression when the pilot opened the canopy to egress...
2016: Aerospace Medicine and Human Performance
Yong Wang, Ting-Ting Ma, Na-Na Gao, Xiao-Ling Zhou, Jiang Hong, Rui Guo, Li-Na Jia, Hong Chang, Ying Gao, Zhi-Min Gao, Lei Pan
ETHNOPHARMACOLOGICAL RELEVANCE: Tongxinluo (TXL),which is a Chinese medicine rooted from traditional used herbs, has been used in clinic to treat cardiovascular and cerebrovascular diseases. However, it remains unknown whether TXL alleviates low pressure hypoxic pulmonary hypertension. AIM OF THE STUDY: Here, we aimed to observe the influence of TXL on pulmonary hypertension in a rat model that exposed to high altitude environment characterized by low pressure hypoxia...
October 10, 2016: Journal of Ethnopharmacology
Qingshu Wang, Ling Hu, Yu Hu, Gu Gong, Hua Tan, Li Deng, Xiaoqin Sun, Xiaobo Yi, Yangyang Sun, Wei Wu, Tao Li
OBJECTIVE: To investigate the therapeutic effect of carbon monoxide (CO) on high-altitude hypoxia-induced cardiac damage. METHODS: Forty male C57BL/6 mice were randomly divided into 4 groups. The mice were exposed to normoxia or simulated 5,500-meter high-altitude hypoxia in a hypobaric chamber for 7 days. During the first 3 days, the mice were pretreated with CO-saturated hemoglobin (Hb)-based oxygen carrier (CO-HBOC), oxygen-saturated hemoglobin-based oxygen carrier (O2-HBOC) at a dose of 0...
October 12, 2016: Cardiology
David Eisenbrey, Arthur B Eisenbrey, Patrick Pettengill
Endotracheal tubes are intended to protect the airway and assist with mechanical ventilation in sedated patients. The blood vessels of the tracheal mucosa can be compressed by high tracheal tube cuff pressures (> 30 cm H2O), leading to reduced mucosal blood flow with resulting ischemia and morbidity. Previous research showed a direct correlation between aircraft pressure altitude and the pressure reading from the tracheal cuff, with resulting pressures > 80 cm H2O at 10,000 ft. Standard practice is to periodically remove air from the cuff during ascent based on assumed increased pressure on the adjacent tracheal mucosa...
September 2016: Air Medical Journal
Samuel Helfer, Joseph Quackenbush, Michael Fletcher, David R Pendergast
BACKGROUND: Climbing and trekking at altitude are common recreational and military activities. Physiological effects of altitude are hypoxia and hyperventilation. The hyperventilatory response to altitude may cause respiratory muscle fatigue and reduce sustained submaximal exercise. Voluntary isocapnic hyperpnea respiratory muscle training (VIHT) improves exercise endurance at sea level and at depth. The purpose of this study was to test the hypothesis that VIHT would improve exercise time at altitude [3600 m (11,811 ft)] compared to control and placebo groups...
August 2016: Aerospace Medicine and Human Performance
Thomas Blakeman, Dario Rodriquez, James Woods, Daniel Cox, Joel Elterman, Richard Branson
BACKGROUND: Successful mechanical ventilation requires that the airway be controlled by an endotracheal tube (ETT) with an inflatable cuff to seal the airway. Aeromedical evacuation represents a unique challenge in which to manage ETT cuffs. We evaluated three methods of automatic ETT cuff pressure adjustment during changes in altitude in an altitude chamber. METHODS: Size 7.5 and 8.0 mm ETTs that are currently included in the Critical Care Air Transport Team allowance standard were used for the evaluation...
November 2016: Journal of Trauma and Acute Care Surgery
S H Li, S Li, L Sun, Z Z Bai, Q Y Yang, Q Ga, G E Jin
OBJECTIVE: To investigate the correlation between pulmonary artery pressure (PAP) and the expression level of Egl nine homologue 1 (EGLN1) gene or its protein in lung tissue of rats at different altitudes. METHODS: Totally 121 male Wistar rats were randomly divided into low altitude group (n=11), moderate altitude group and high altitude group, the rats in moderate altitude and high altitude group were further divided into 1(st) day, 3(rd) days, 7(th) days, 15(th) day and 30(th) day group according to the exposure time to hypoxic environment, each group 11 rats...
August 23, 2016: Zhonghua Yi Xue za Zhi [Chinese medical journal]
Oliver Michael Shannon, Lauren Duckworth, Matthew John Barlow, David Woods, Jose Lara, Mario Siervo, John Paul O'Hara
Nitrate-rich beetroot juice (BRJ) increases plasma nitrite concentrations, lowers the oxygen cost (V⋅O2) of steady-state exercise and improves exercise performance in sedentary and moderately-trained, but rarely in well-trained individuals exercising at sea-level. BRJ supplementation may be more effective in a hypoxic environment, where the reduction of nitrite into nitric oxide (NO) is potentiated, such that well-trained and less well-trained individuals may derive a similar ergogenic effect. We conducted a randomised, counterbalanced, double-blind placebo controlled trial to determine the effects of BRJ on treadmill running performance in moderate normobaric hypoxia (equivalent to 2500 m altitude) in participants with a range of aerobic fitness levels...
September 30, 2016: Nitric Oxide: Biology and Chemistry
Pierre J L Valk, Ries Simons, Andrea M Jetten, Román Valiente, Luis Labeaga
INTRODUCTION: Bilastine is a new oral, second generation antihistamine used in the symptomatic treatment of allergic rhinoconjunctivitis and urticaria. It is considered a nonsedating antihistamine and might be recommended for use in pilots, pending research on the effects on flying-related performance under hypobaric conditions that prevail in an airliner. We assessed the effects of a single dose of bilastine 20 mg on alertness and complex task performance of healthy volunteers in a hypobaric chamber at 75...
July 2016: Aerospace Medicine and Human Performance
Andrew A Pilmanis, Ulf I Balldin, Joseph R Fischer
INTRODUCTION: The effects of low-grade hypoxia on cognitive function are reported in this paper. The study compared cognitive function during short exposures at four different altitudes. METHODS: Ninety-one subjects were exposed to simulated altitudes of ground level, 1524, 2438, and 3658 m (5000, 8000, and 12,000 ft) in the Brooks City-Base altitude pressure chamber in a balanced design. Oxygen saturation, heart rate, and cognitive performance on seven different cognitive tasks were measured...
July 2016: Aerospace Medicine and Human Performance
Lixia Yu, Yuan Chen, Weiguang Wang, Zhonghai Xiao, Yan Hong
Hypobaric hypoxia (HH) leads to reduced oxygen delivery to brain. It could trigger cognitive dysfunction and increase the risk of dementia including Alzheimer's disease (AD). The present study was undertaken in order to examine whether B vitamins (B6, B12, folate, and choline) could exert protective effects on hypoxia-induced memory deficit and AD related molecular events in mice. Adult male Kunming mice were assigned to five groups: normoxic control, hypoxic model (HH), hypoxia+vitamin B6/B12/folate (HB), hypoxia+choline (HC), hypoxia+vitamin B6/B12/folate+choline (HBC)...
August 4, 2016: Journal of Alzheimer's Disease: JAD
Xuyi Li, Yan Liu, Huijie Ma, Yue Guan, Yue Cao, Yanming Tian, Yi Zhang
BACKGROUND AND AIMS: Previous studies demonstrated that energy metabolism disturbance impairs cardiac function and chronic intermittent hypobaric hypoxia (CIHH) protects heart against ischemia/reperfusion injury. The present study aimed to test the hypothesis that CIHH protects the heart against ischemia/reperfusion (I/R) injury via improvement of cardiac glucose metabolism. METHODS: Male Sprague-Dawley rats received CIHH treatment simulating 5000-m altitude for 28 days, 6 h per day in a hypobaric chamber or no treatment (control)...
2016: Frontiers in Physiology
Na Li, Yue Guan, Li Zhang, Yanming Tian, Yi Zhang, Sheng Wang
Baroreflex function plays a critical role in the maintenance of cardiovascular homeostasis and is impaired in different types of hypertension in both human and animals. Chronic intermittent hypobaric hypoxia (CIHH) facilitates baroreflex in anesthetized rats. The aim of present study was to investigate the effect of CIHH on arterial blood pressure (ABP) and baroreflex function in renal vascular hypertension (RVH) rats. Adult male Sprague-Dawley rats were randomly divided into four groups: Sham-operated (SHAM), RVH, CIHH treatment (CIHH), and RVH plus CIHH (RVH+CIHH) groups...
August 31, 2016: Chinese Journal of Physiology
Nicole Lüneburg, Patricia Siques, Julio Brito, Karem Arriaza, Eduardo Pena, Hans Klose, Fabiola Leon-Velarde, Rainer H Böger
Chronic intermittent hypoxia (CIH) and chronic hypoxia (CH) are associated with high-altitude pulmonary hypertension (HAPH). Asymmetric dimethylarginine (ADMA), a NO synthase (NOS) inhibitor, may contribute to HAPH. This study assessed changes in the ADMA/NO pathway and the underlying mechanisms in rat lungs following exposure to CIH or CH simulated in a hypobaric chamber at 428 Torr. Twenty-four adult Wistar rats were randomly assigned to three groups: CIH2x2 (2 days of hypoxia/2 days of normoxia), CH, and NX (permanent normoxia), for 30 days...
2016: Pulmonary Medicine
Samir Saba, Evan Adelstein, Nicholas Wold, Kenneth Stein, Paul Jones
AIMS: Patients have increasing comorbidities and competing causes of death with advancing age, raising questions about the effectiveness of the implantable cardioverter defibrillators (ICD) in older age. We therefore investigated the effect of patients' age at initial device implantation on all-cause mortality and on the risk of ICD shocks in single-chamber (V-ICD), dual-chamber (D-ICD), and cardiac resynchronization therapy defibrillator (CRT-D) recipients. METHODS AND RESULTS: We reviewed de-identified records of 67 128 ICD recipients enrolled in the Boston Scientific ALTITUDE database of remote monitored patients [V-ICD (n = 11 422), D-ICD (n = 23 974), and CRT-D (n = 31 732)]...
June 2, 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
Xianrong Xu, Binru Wang, Zhanguo Jin, Yang Zhang
BACKGROUND: This study was undertaken to establish a dynamic animal model of sinus barotrauma (SB). METHODS: The right nasal cavities of 65 rabbits were filled with sponges to obstruct the right ostiomeatal complex (OMC), while in the left nasal cavities, the left OMC was kept clear. The rabbits were exposed to hypobaric chamber simulation. The right sinuses were assigned as the model group, randomly divided into 13 subgroups with 5 in each subgroup, while the left sinuses were assigned as the control group...
June 2016: Aerospace Medicine and Human Performance
James T Webb, Thomas R Morgan, Sean D Sarsfield
INTRODUCTION: Earlier research described a linear relationship between the highest 1 min of oxygen consumption (Vo2) during a recurring physical activity and incidence of decompression sickness (DCS) during research chamber exposures to high altitude. The current effort was designed to determine if that relationship holds true at a lower altitude. METHODS: Male subjects (20) were exposed without prebreathe to 22,500 ft (6858 m; 314 mmHg; 6.1 psi) for 4 h while seated, nonambulatory the entire time, with echo-imaging at 16-min intervals (Non-Amb Echo), breathing 100% oxygen...
June 2016: Aerospace Medicine and Human Performance
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