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Altitude sickness

Carla Ippoliti, Maria Goffredo, Romolo Salini, Michele Bocci, Michela Quaglia, Valentina Federici, Sandro Pelini, Adriana Santilli, Susanna Tora, Annamaria Conte
Bluetongue, Schmallenberg and African horse sickness viruses are transmitted by vectors belonging to the genus Culicoides (Diptera: Ceratopogonidae). Among this genus, species of the Obsoletus complex play a crucial role in Europe. In Italy the complex includes three species: Culicoides obsoletus sensu strictu, Culicoides scoticus and Culicoides montanus. These three sibling species were identified in 80 collection sites across Italy through a multiplex PCR test. Sixty‑four sites were classified with a predominant species through a Bayesian approach...
September 30, 2016: Veterinaria Italiana
Teófilo Lorente-Aznar, Guillermo Perez-Aguilar, Alma García-Espot, Sergio Benabarre-Ciria, Juan Luis Mendia-Gorostidi, Daniel Dols-Alonso, Julia Blasco-Romero
BACKGROUND AND OBJECTIVES: Arterial Oxygen Saturation (AOS) predicts altitude sickness. OBJECTIVES: To estimate the AOS values with relation to altitude. Furthermore, make a graph to use during activity which assesses the AOS for each altitude and the normal range. PATIENTS AND METHOD: Values of AOS were assessed during eight high mountain activities in the Alps, Himalaya, Caucasus and Andes; 53 mountaineers participated, 17 of them in more than one activity; 761 measurements of AOS were registered...
September 27, 2016: Medicina Clínica
Jose V Lafuente, G Bermudez, L Camargo-Arce, S Bulnes
Cerebral syndromes related to high altitude exposure are becoming more frequent as the number of trips to high altitudes has increased in the last decade. The commonest symptom is headache, followed by acute mountain sickness (AMS) and high-altitude cerebral edema (HACE), which can be fatal. The pathophysiology of these syndromes is not fully comprehended. The classical "tight-fit hypothesis" defends the fact that there are some anatomical variations that would obstruct the sinovenous outflow and worsen the vasogenic edema and intracranial hypertension reactive to hypoxia...
September 20, 2016: CNS & Neurological Disorders Drug Targets
Roberta Rosas Petrocinio, Elga Dias Gomes
BACKGROUND: High altitude retinopathy (HAR) includes a number of diseases related to high altitude such as acute mountain sickness (AMS), high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE). High altitude retinopathy is mainly characterized by retinal hemorrhages, usually sparing the macular region, a condition specifically known as high altitude retinal hemorrhages (HARH). The pathogenesis of HARH is unclear. Many studies show that lack of oxygen causes an inadequate autoregulation of retinal circulation, causing vascular incompetence...
2016: Aerospace Medicine and Human Performance
Samuel Verges, Thomas Rupp, Marjorie Villien, Laurent Lamalle, Irène Troprés, Camille Poquet, Jan M Warnking, François Estève, Pierre Bouzat, Alexandre Krainik
OBJECTIVE: Hypoxic exposure in healthy subjects can induce acute mountain sickness including headache, lethargy, cerebral dysfunction, and substantial cerebral structural alterations which, in worst case, can lead to potentially fatal high altitude cerebral edema. Within this context, the relationships between high altitude-induced cerebral edema, changes in cerebral perfusion, increased brain parenchyma volume, increased intracranial pressure, and symptoms remain unclear. METHODS: In 11 subjects before and after 6 days at 4350 m, we performed multiparametric magnetic resonance investigations including anatomical, apparent diffusion coefficient and arterial spin labeling sequences...
2016: Frontiers in Physiology
Cunxiu Fan, Yuhua Zhao, Qian Yu, Wu Yin, Haipeng Liu, Jianzhong Lin, Tianhe Yang, Ming Fan, Luobu Gesang, Jiaxing Zhang
A large proportion of lowlanders ascending to high-altitude (HA) show no signs of mountain sickness. Whether their brains have indeed suffered from HA environment and the persistent sequelae after return to lowland remain unknown. Thirty-one sea-level college students, who had a 30-day teaching on Qinghai-Tibet plateau underwent MRI scans before, during, and two months after HA exposure. Brain volume, cortical structures, and white matter microstructure were measured. Besides, serum neuron-specific enolase (NSE), C-reactive protein, and interleukin-6 and neuropsychiatric behaviors were tested...
2016: Scientific Reports
Soon Bae Kim, Jong Sung Kim, Sang Jun Kim, Su Hee Cho, Dae Chul Suh
Medical congresses often held in highlands. We reviewed several medical issues associated with altitude stress especially while physicians have participated medical congress held in high altitude. Altitude stress, also known as an acute mountain sickness (AMS), is caused by acute exposure to low oxygen level at high altitude which is defined as elevations at or above 1,200 m and AMS commonly occurs above 2,500 m. Altitude stress with various symptoms including insomnia can also be experienced in airplane. AMS and drunken state share many common features in symptoms, neurologic manifestations and even show multiple microbleeds in corpus callosum and white matter on MRI...
September 2016: Neurointervention
Xiaoli Han, Dan Su, Xiaoyan Xian, Mingyang Zhou, Xianzhe Li, Jian Huang, Jinhui Wang, Huiyuan Gao
ETHNOPHARMACOLOGICAL RELEVANCE: Saussurea involucrate (Kar. et Kir.) Sch. -Bip is an endangered species of the Compositae family, and this species has long been used for the treatment of rheumatoid arthritis, dysmenorrhea, stomachache, and altitude sickness in Uighur folk and Chinese medicine. AIM OF THE STUDY: This study aimed to investigate the different therapeutic efficacy of alcohol infusion (SEI) and water decoction (SWD) of S. involucrata in treating rheumatoid arthritis using complete Freund's adjuvant (CFA)-induced arthritis (AA) in a rat model...
September 8, 2016: Journal of Ethnopharmacology
Sofien Laouafa, Elizabeth Elliot-Portal, Susana Revollo, Edith M Schneider Gasser, Vincent Joseph, Nicolas Voituron, Max Gassmann, Jorge Soliz
The impact of cerebral Epo in the regulation of the hypercapnic ventilatory response (HcVR) is controversial. While we reported that cerebral Epo does not affect the central chemosensitivity in C57Bl6 mice receiving an intracisternal injection of sEpoR (the endogenous antagonist of Epo), a recent study in transgenic mice with constitutive high levels of human Epo in brain and circulation (Tg6) and in brain only (Tg21), showed that Epo blunts the HcVR, maybe by interacting with central and peripheral chemoreceptors...
September 7, 2016: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology
Philip J Hennis, Kay Mitchell, Edward Gilbert-Kawai, Vassiliki Bountziouka, Angie Wade, Martin Feelisch, Michael P Grocott, Daniel S Martin
: The purpose of this study was to investigate the effects of dietary nitrate supplementation, in the form of beetroot juice, on acute mountain sickness (AMS) symptoms and physiological responses, in a group of young males trekking to Mount Everest Base Camp (EBC). Forty healthy male students (mean age (SD): 16 (1) yrs) trekked to EBC over 11 days. Following an overnight fast, each morning participants completed the Lake Louise AMS questionnaire and underwent a series of physiological tests: resting blood pressure as well as resting and exercising heart rate, respiratory rate, and peripheral oxygen saturation...
September 2, 2016: Nitric Oxide: Biology and Chemistry
Carine Malle, Benoît Ginon, Cyprien Bourrilhon
: Malle, Carine, Benoît Ginon, and Cyprien Bourrilhon. Brief working memory and physiological monitoring during a high-altitude expedition. High Alt Med Biol 00:000-000, 2016. BACKGROUND: Various studies have shown the deleterious effects of high-altitude hypoxia on cognitive functions, including attention and memory. Since optimal cognitive abilities may be crucial for mountain safety, this study was aimed to assess the relevance of a brief working memory test to quickly assess cognition at high altitude...
August 22, 2016: High Altitude Medicine & Biology
Carla Gonzales-Arimborgo, Irma Yupanqui, Elsa Montero, Dulce E Alarcón-Yaquetto, Alisson Zevallos-Concha, Lidia Caballero, Manuel Gasco, Jianping Zhao, Ikhlas A Khan, Gustavo F Gonzales
The plant maca, grown at 4000 m altitude in the Peruvian Central Andes, contains hypocotyls that have been used as food and in traditional medicine for centuries. The aim of this research was to provide results on some health effects of oral administration of spray-dried extracts of black or red maca (Lepidium meyenii) in adult human subjects living at low (LA) and high altitude (HA). A total of 175 participants were given 3 g of either placebo, black, or red maca extract daily for 12 weeks. Primary outcomes were changes in sexual desire, mood, energy, health-related quality of life score (HRQL), and chronic mountain sickness (CMS) score, or in glycaemia, blood pressure, and hemoglobin levels...
August 18, 2016: Pharmaceuticals
Philip E Bickler, John R Feiner, Michael S Lipnick, Paul Batchelder, David B MacLeod, John W Severinghaus
Extended periods of oxygen deprivation can produce acidosis, inflammation, energy failure, cell stress, or cell death. However, brief profound hypoxia (here defined as SaO2 50%-70% for approximately 10 minutes) is not associated with cardiovascular compromise and is tolerated by healthy humans without apparent ill effects. In contrast, chronic hypoxia induces a suite of adaptations and stresses that can result in either increased tolerance of hypoxia or disease, as in adaptation to altitude or in the syndrome of chronic mountain sickness...
August 12, 2016: Anesthesia and Analgesia
Martin J MacInnis, Michael S Koehle
MacInnis, Martin J., and Michael S. Koehle. Evidence for and against genetic predispositions to acute and chronic altitude illnesses. High Alt Med Biol 00:000-000, 2016.-Humans exhibit marked variation in their responses to hypoxia, with susceptibility to acute and chronic altitude illnesses being a prominent and medically important example. Many have hypothesized that genetic differences are the cause of these variable responses to hypoxia; however, until recently, these hypotheses were based primarily on small (and sometimes anecdotal) reports pertaining to apparent differences in altitude illness susceptibility between populations, the notion that a history of altitude illness is indicative of subsequent risk, the heritability of hypoxia-related traits, and candidate gene association studies...
August 8, 2016: High Altitude Medicine & Biology
Shizheng Wu, Guisheng Hao, Shukun Zhang, Dongmei Jiang, Tana Wuren, Junming Luo
The aim of the present study was to examine cerebral vasoconstriction in patients with chronic high altitude disease [cerebrovascular reactivity (CVR)], and to evaluate differences in alterations of brain vascular contractile reactivity of chronic mountain sickness (CMS) patients and healthy controls. Alterations of endothelin (ET) and its receptor, as well as endothelial nitric oxide synthase (eNOS) levels in the plasma were examined to determine the cerebral reservation capacities in CMS patients. Transcranial Doppler ultrasound and carbon dioxide analysis methods were used to detect the CVR variances...
September 2016: Molecular Medicine Reports
Qing Hai Shi, Di Ge, Wei Zhao, Xue Ma, Ke Yan Hu, Yao Lu, Zheng Xiang Liu, Ji Hua Ran, Xiao Ling Li, Yu Zhou, Jian Feng Fu
To evaluate the effect of acute high-altitude exposure on sensory and short-term memory using interactive software, we transported 30 volunteers in a sport utility vehicle to a 4280 m plateau within 3 h. We measured their memory performance on the plain (initial arrival) and 3 h after arrival on the plateau using six measures. Memory performance was significantly poorer on the plateau by four of the six measures. Furthermore, memory performance was significantly poorer in the acute mountain sickness (AMS) group than in the non-AMS group by five of the six measures...
June 2016: Biomedical and Environmental Sciences: BES
Amine N Issa, Nicole M Herman, Robert J Wentz, Bryan J Taylor, Doug C Summerfield, Bruce D Johnson
OBJECTIVE: It is well documented that cognitive performance may be altered with ascent to altitude, but the association of various cognitive performance tests with symptoms of acute mountain sickness (AMS) is not well understood. Our objective was to assess and compare cognitive performance during a high-altitude expedition using several tests and to report the association of each test with AMS, headache, and quality of sleep. METHODS: During an expedition to Mount Everest, 3 cognitive tests (Stroop, Trail Making, and the real-time cognitive assessment tool, an in-house developed motor accuracy test) were used along with a questionnaire to assess health and AMS...
September 2016: Wilderness & Environmental Medicine
Katherine Healy, Alain B Labrique, J Jaime Miranda, Robert H Gilman, David Danz, Victor G Davila-Roman, Luis Huicho, Fabiola León-Velarde, William Checkley
Healy, Katherine, Alain B. Labrique, J. Jaime Miranda, Robert H. Gilman, David Danz, Victor G. Davila-Roman, Luis Huicho, Fabiola León-Velarde, and William Checkley. Dark adaptation at high altitude: an unexpected pupillary response to chronic hypoxia in Andean highlanders. High Alt Med Biol. 16:000-000, 2016.-Chronic mountain sickness is a maladaptive response to high altitude (>2500 m above sea level) and is characterized by excessive erythrocytosis and hypoxemia resulting from long-term hypobaric hypoxia...
July 25, 2016: High Altitude Medicine & Biology
David J Collier, Chris B Wolff, Anne-Marie Hedges, John Nathan, Rod J Flower, James S Milledge, Erik R Swenson
Acetazolamide is the standard carbonic anhydrase (CA) inhibitor used for acute mountain sickness (AMS), however some of its undesirable effects are related to intracellular penetrance into many tissues, including across the blood-brain barrier. Benzolamide is a much more hydrophilic inhibitor, which nonetheless retains a strong renal action to engender a metabolic acidosis and ventilatory stimulus that improves oxygenation at high altitude and reduces AMS. We tested the effectiveness of benzolamide versus placebo in a first field study of the drug as prophylaxis for AMS during an ascent to the Everest Base Camp (5340 m)...
June 2016: Pharmacology Research & Perspectives
Andrew T Lovering, Jonathan E Elliott, James T Davis
The foramen ovale, which is part of the normal fetal cardiopulmonary circulation, fails to close after birth in ∼35% of the population and represents a potential source of right-to-left shunt. Despite the prevalence of patent foramen ovale (PFO) in the general population, cardiopulmonary, exercise, thermoregulatory, and altitude physiologists may have underestimated the potential effect of this shunted blood flow on normal physiological processes in otherwise healthy humans. Because this shunted blood bypasses the respiratory system, it would not participate in either gas exchange or respiratory system cooling and may have impacts on other physiological processes that remain undetermined...
August 1, 2016: Journal of Applied Physiology
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