High altitude medicine & biology最新文献

{"title":"Acclimatized Lowlanders Exhibit a Hypocoagulable Profile after a Passive Ascent at High Altitude.","authors":"Emeric Stauffer, François Caton, Raphael Marlu, Aurélien Pichon, Landry Seyve, Michael Furian, Aymeric Paillisser, Florence Berquet, Jeremy De Abreu, Blandine Deschamps, Benoit Polack, Philippe Connes, Paul Robach, Stéphane Doutreleau, Julien V Brugniaux, Samuel Verges, Benoit Champigneulle","doi":"10.1089/ham.2024.0128","DOIUrl":"https://doi.org/10.1089/ham.2024.0128","url":null,"abstract":"<p><p>Stauffer, Emeric, François Caton, Raphael Marlu, Aurélien Pichon, Landry Seyve, Michael Furian, Aymeric Paillisser, Florence Berquet, Jeremy De Abreu, Blandine Deschamps, Benoit Polack, Philippe Connes, Paul Robach, Stéphane Doutreleau, Julien V Brugniaux, Samuel Verges, and Benoit Champigneulle.Acclimatized lowlanders exhibit a hypocoagulable profile after a passive ascent at high altitude. <i>High Alt Med Biol.</i> 00:00-00, 2024. <b><i>Background:</i></b> Discordant results have been previously reported regarding the impact of high-altitude (HA) exposure on coagulation. We aimed to investigate changes in coagulation parameters in lowlanders exposed to HA for 14 days using a combination of dynamic coagulation assays and conventional <i>in vitro</i> tests. <b><i>Material and Methods:</i></b> We assessed coagulation in 10 lowlanders using whole-blood rotational thromboelastometry (ROTEM), thrombin generation assay (TGA) on poor-platelet plasma, and conventional coagulation tests. Tests were performed at low altitude (LA, 210 m) and at the end of a 14-day sojourn at HA, including passive ascents to 3,800 m for 6 days and then to 5,100 m for 8 days. <b><i>Results:</i></b> Conventional tests revealed significant changes in coagulation factors and inhibitors after HA exposure, although these changes remained within normal ranges. ROTEM assays demonstrated a delayed clot initiation in EXTEM/FIBTEM, without any alteration in clot firmness, in HA versus LA (<i>p</i> < 0.01). TGA changes showed an increase in time to peak (<i>p</i> < 0.01), a decrease in endogenous thrombin potential (<i>p</i> < 0.05), and a decrease in thrombin peak (<i>p</i> < 0.001). <b><i>Conclusions:</i></b> We found no evidence of hypercoagulability in lowlanders after a 14-day sojourn at HA. In contrast, dynamic coagulation assays (ROTEM and TGA) revealed a hypocoagulable pattern.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142846516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal Effects of Hypoxia Exposure at High Altitudes on Compensatory Brain Function: Evidence from Functional Connectivity of Resting-State EEG Brain Networks.","authors":"Hong Ren, Xi-Yue Yang, Rui Su, HaiLin Ma, Hao Li","doi":"10.1089/ham.2024.0063","DOIUrl":"https://doi.org/10.1089/ham.2024.0063","url":null,"abstract":"<p><p>Ren, Hong, Xi-Yue Yang, Rui Su, HaiLin Ma, and Hao Li. Temporal Effects of Hypoxia Exposure at High Altitudes on Compensatory Brain Function: Evidence from Functional Connectivity of Resting-State EEG Brain Networks. <i>High Alt Med Biol.</i> 00:00-00, 2024. <b><i>Background:</i></b> The aim of this study was to investigate the effects of prolonged exposure to hypobaric hypoxia at high altitude on changes in brain function measured by electroencephalography (EEG), focusing specifically on the resting-state brain network functional connectivity and compensatory adaptations in brain function among individuals with varying durations of high altitude residency. <b><i>Methods:</i></b> In study I, 64 participants were divided into high-altitude group (HG) and low-altitude group (LG). Ninety-six long-term migrants residing at an altitude of 3,650 m were recruited for studyII and categorized into three groups based on their duration of stay at high altitude: group A (1-2 years), group B (8-10 years), and group C (18-20 years). Resting-state EEG data were collected from each participant, and functional connectivity analysis was conducted using Phase Locking Value. <b><i>Results:</i></b> Study I showed that participants with HG had stronger functional connectivity in the occipital lobe than those with LG (<i>p</i> < 0.05). The study II findings indicate that there were significant differences in functional connectivity strength among the frontal and occipital lobes in groups A, B, and C across the α, β, δ, and θ frequency bands. Specifically, the functional connectivity strength of the frontal lobe was significantly higher in group A compared with group B, and in group B compared with group C (<i>p</i> < 0.05). Additionally, the functional connectivity of the occipital lobe was significantly higher in group C compared with group B, and in group B compared with group A (<i>p</i> < 0.05). <b><i>Conclusions:</i></b> The consistent results of the whole frequency band suggest that the individual's occipital lobe function is enhanced to compensate for the damage of frontal lobe function, so as to better adapt to the extreme environment at high altitude.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142846529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Zinc Homeostasis Plays Important Roles in Hypoxia Tolerance: A Study Conducted Clinically and <i>In Vitro</i>.","authors":"Yan Guo, Chao Yu, Zhongsheng Lu, Menglan Zhang, Qiang Zhang, Xiao Liu","doi":"10.1089/ham.2024.0036","DOIUrl":"https://doi.org/10.1089/ham.2024.0036","url":null,"abstract":"<p><p>Guo, Yan, Chao Yu, Zhongsheng Lu, Menglan Zhang, Qiang Zhang, and Xiao Liu. Zinc homeostasis plays important roles in hypoxia tolerance: A study conducted clinically and <i>in vitro</i>. <i>High Alt Med Biol.</i> 00:00-00, 2024. <b><i>Objective:</i></b> High-altitude environments pose significant challenges to human physiology due to reduced oxygen availability, often resulting in altitude-related illnesses such as high-altitude cerebral edema (HACE). This study focuses on understanding the role of zinc homeostasis in enhancing hypoxia tolerance, which may be pivotal in mitigating the adverse effects of such illnesses. <b><i>Methods:</i></b> The study involved healthy individuals from high-altitude (4,500-5,000 m) and low-altitude areas (0-200 m), as well as patients with HACE. Blood samples were collected and analyzed. Additionally, a hypoxic model was developed using human brain microvascular endothelial cells (HBMECs), and zinc intervention was implemented. <b><i>Results:</i></b> In the blood samples of patients with HACE and those of healthy individuals, there were over 4,000 differentially expressed genes (DEGs), with more than 300 of them linked to zinc. Among these zinc-associated genes, only carbonic anhydrase I (CA1) exhibited a substantial upregulation in expression, while the expression of others was notably downregulated. Compared with the high-altitude group, hemoglobin (Hb) (14.7 vs. 19.5 g/dl) and plasma zinc (37.0 vs. 94.0 mmol/dl) were lower in HACE, while CA1 (55.4 vs. 8.6 g/l) was elevated (<i>p</i> < 0.01). <i>In vitro</i> studies confirmed that exposure to hypoxia (O₂ 8%-8.5%, 24 hours) inhibited HBMECs proliferation and migration, increased apoptosis and necrosis, and led to abnormal expression of CA1 and various zinc transport proteins. However, zinc intervention (6 μM, 24 hours) significantly mitigated these adverse effects and improved the cell's ability to tolerate hypoxia. <b><i>Conclusion:</i></b> Zinc homeostasis was crucial for hypoxia tolerance. Proper zinc supplementation could potentially alleviate symptoms associated with hypoxia intolerance, such as altitude sickness, but further confirmation was needed.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142806881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effects of Nocturnal Hypoxemia on Cognitive Performance in Andean Highlanders.","authors":"Elizabeth V Young, Matea A Djokic, Erica C Heinrich, Traci Marin, Cecilia Anza-Ramirez, Jeremy E Orr, Dillon Gilbertson, Pamela N DeYoung, Gustavo Vizcardo-Galindo, Rómulo Figueroa-Mujica, Francisco C Villafuerte, Atul Malhotra, Tatum S Simonson","doi":"10.1089/ham.2024.0077","DOIUrl":"10.1089/ham.2024.0077","url":null,"abstract":"<p><p><b><i>Background:</i></b> Many Andean highlanders exposed to chronic hypoxemia are susceptible to excessive erythrocytosis (EE) and chronic mountain sickness (CMS). Nocturnal hypoxemia is more marked than diurnal hypoxemia and includes sustained and intermittent components. The potential for cognitive impairments related to nocturnal hypoxemia in this population has not been extensively studied, but improved understanding may provide opportunities for the prevention of long-term effects of EE and CMS. <b><i>Methods:</i></b> To examine this relationship, 48 participants residing permanently at 4,340 m completed an overnight sleep study and a battery of cognitive function tests that examined a broad range of cognitive domains. <b><i>Results:</i></b> Greater nocturnal hypoxemia was associated with longer reaction times on Balloon Analogue Risk Task (BART) (<i>p</i> < 0.01) and Emotion Recognition Test (ERT) (<i>p</i> < 0.01). Longer completion times of Trail Making Task were also associated with increased nocturnal hypoxemia (<i>p</i> = 0.03). Increased hematocrit was similarly associated with longer reaction times on the ERT (<i>p</i> = 0.01) and the BART (<i>p</i> = 0.01). <b><i>Conclusion:</i></b> Overall, our results showed that increased nocturnal hypoxemia and higher hematocrit were associated with impairments in cognitive performance in individuals residing permanently at high altitude.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142806879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Letter to the Editor:</i> Vital Signs Below 24°C. A Positive Contribution of Alcohol to Survival in Hypothermia?","authors":"Ian J Cohen","doi":"10.1089/ham.2024.0136","DOIUrl":"https://doi.org/10.1089/ham.2024.0136","url":null,"abstract":"","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142780194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recurrent Pulmonary Embolism at High Altitude in a Mountaineer with Hereditary Thrombophilia.","authors":"Robert K Szymczak, Magdalena Sawicka, Małgorzata Jelitto","doi":"10.1089/ham.2023.0110","DOIUrl":"10.1089/ham.2023.0110","url":null,"abstract":"<p><p>Szymczak, Robert K., Magdalena Sawicka, and Małgorzata Jelitto. Recurrent pulmonary embolism at high altitude in a mountaineer with hereditary thrombophilia. <i>High Alt Med Biol.</i> 25:345-347, 2024.-It is speculated that high-altitude travel is an independent risk factor for thrombosis. Mountaineering-specific factors, such as hypoxia, cold, and immobilization, may interact with patient-specific risk factors and contribute to thrombus formation. We present the case of a mountaineer with hereditary thrombophilia who experienced recurrent pulmonary embolism during high-altitude expeditions.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":"345-347"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141199630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Potential Interplay Between HIF-1α, Angiogenic, and Autophagic Signaling During Intermittent Hypoxic Exposure and Exercise.","authors":"Quint N Berkemeier, Michael R Deyhle, James J McCormick, Kurt A Escobar, Christine M Mermier","doi":"10.1089/ham.2023.0090","DOIUrl":"10.1089/ham.2023.0090","url":null,"abstract":"<p><p>Berkemeier, Quint N., Michael R. Deyhle, James J. McCormick, Kurt A. Escobar, and Christine M. Mermier. The potential interplay between HIF-1α, angiogenic, and autophagic signaling during intermittent hypoxic exposure and exercise <i>High Alt Med Biol.</i> 25:326-336, 2024.-Environmental hypoxia as a result of decreased barometric pressure upon ascent to high altitudes (>2,500 m) presents increased physiological demands compared with low altitudes, or normoxic environments. Competitive athletes, mountaineers, wildland firefighters, military personnel, miners, and outdoor enthusiasts commonly participate in, or are exposed to, forms of exercise or physical labor at moderate to high altitudes. However, the majority of research on intermittent hypoxic exposure is centered around hematological markers, and the skeletal muscle cellular responses to exercise in hypoxic environments remain largely unknown. Two processes that may be integral for the maintenance of cellular health in skeletal muscle include angiogenesis, or the formation of new blood vessels from preexisting vasculature and autophagy, a process that removes and recycles damaged and dysfunctional cellular material in the lysosome. The purpose of this review is to is to examine the current body of literature and highlight the potential interplay between low-oxygen-sensing pathways, angiogenesis, and autophagy during acute and prolonged intermittent hypoxic exposure in conjunction with exercise. The views expressed in this paper are those of the authors and do not reflect the official policy of the Department of Army, DOD, DOE, ORAU/ORISE or U.S. Government.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":"326-336"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140848779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ileus at Altitude.","authors":"Christine Ebert-Santos, Ana Campos","doi":"10.1089/ham.2023.0132","DOIUrl":"10.1089/ham.2023.0132","url":null,"abstract":"<p><p>Ebert-Santos, Christine, and Ana Campos. Ileus at altitude. <i>High Alt Med Biol.</i> 25:342-344, 2024.-Autoimmune myasthenia gravis (MG) is a condition commonly caused by the production of antibodies that block acetylcholine receptors. Until recently, gastrointestinal (GI) symptoms were considered rare in myasthenia gravis, but are now being proposed as an early identification tool. Presented here is a case study that exemplifies GI symptoms in MG, exacerbated by low barometric pressure at altitude. This illustrates the need to identify GI symptoms earlier in MG patients, as well as the need for providers at high altitude to be aware of these manifestations of MG.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":"342-344"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141491646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MALAT1 and NEAT1 are Neuroprotective During Hypoxic Preconditioning in the Mouse Hippocampus Possibly by Regulation of NR2B.","authors":"Liping Wang, Gang Fu, Ruijuan Han, Peijia Fan, Jing Yang, Kerui Gong, Zhijun Zhao, Chunyang Zhang, Kai Sun, Guo Shao","doi":"10.1089/ham.2023.0135","DOIUrl":"10.1089/ham.2023.0135","url":null,"abstract":"<p><p>Wang, Liping, Gang Fu, Ruijuan Han, Peijia Fan, Jing Yang, Kerui Gong, Zhijun Zhao, Chunyang Zhang, Kai Sun, and Guo Shao. MALAT1 and NEAT1 are neuroprotective during hypoxic preconditioning in the mouse hippocampus possibly by regulation of NR2B. <i>High Alt Med Biol.</i> 25:285-294, 2024. <b><i>Background:</i></b> The regulation of noncoding ribonucleic acid (ncRNA) has been shown to be involved in cellular and molecular responses to hypoxic preconditioning (HPC), a situation created by the induction of sublethal hypoxia in the brain. The ncRNAs metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and nuclear paraspeckle assembly transcript 1 (NEAT1) are abundantly expressed in the brain, where they regulate the expression of various genes in nerve cells. However, the exact roles of MALAT1 and NEAT1 in HPC are not fully understood. <b><i>Methods:</i></b> A mouse model of acute repeated hypoxia was used as a model of HPC, and MALAT1 and NEAT1 levels in the hippocampus were measured using real-time polymerase chain reaction (PCR). The mRNA and protein levels of <i>N</i>-methyl-d-aspartate receptor subunit 2 B (NR2B) in the mouse hippocampus were measured using real-time PCR and western blotting, respectively. HT22 cells knocked-down for MALAT1 and NEAT1 were used for <i>in vitro</i> testing. Expression of NR2B, which is involved in nerve cell injury under ischemic and hypoxic conditions, was also evaluated. The levels of spectrin and cleaved caspase-3 in MALAT1 and NEAT1 knockdown HT22 cells under oxygen glucose deprivation/reperfusion (OGD/R) were determined by western blotting. <b><i>Results:</i></b> HPC increased the expression of MALAT1 and NEAT1 and decreased the expression of NR2B mRNA in the mouse hippocampus (<i>p</i> < 0.05). Knockdown of MALAT1 and NEAT1 increased both NR2B mRNA and protein levels nearly twofold and caused damage under OGD/R conditions in HT22 cells (<i>p</i> < 0.05). <b><i>Conclusion:</i></b> MALAT1 and NEAT1 exert neuroprotective effects by influencing the expression of NR2B.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":"285-294"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141159991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical Conundrum: Return to High Altitude After Cerebral Venous Sinus Thrombosis.","authors":"Andrew M Luks, Thomas G DeLoughery, Jeffrey H Gertsch, Suzy Stokes","doi":"10.1089/ham.2024.0079","DOIUrl":"10.1089/ham.2024.0079","url":null,"abstract":"<p><p>Luks, Andrew M., Thomas G. DeLoughery, Jeffrey H. Gertsch, and Suzy Stokes. Clinical conundrum: return to high altitude after cerebral venous sinus thrombosis. <i>High Alt Med Biol.</i> 25:337-341, 2024.</p>","PeriodicalId":12975,"journal":{"name":"High altitude medicine & biology","volume":" ","pages":"337-341"},"PeriodicalIF":1.6,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141534274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}