High altitude medicine & biology最新文献

Epçaçan, Serdar, Emrah Şişli, Yasemin Nuran Dönmez, and Şeyma Memur. The course of ductus arteriosus from the neonatal period to childhood in a moderate altitude region. High Alt Med Biol. 00:00-00, 2025. Aim: The aim of the study is to evaluate the course of patent ductus arteriosus (PDA) in a moderate altitude region. Study Design: This is a retrospectively designed cross-sectional study analyzing the neonates diagnosed with PDA. Methods: Demographic and clinical data and echocardiographic, interventional, and surgical files of the subjects and follow-up findings were analyzed. Results: Overall, the mean gestational age and weight at delivery for all 711 patients were 35.7 ± 3.1 weeks (24-44 weeks) and 2712 ± 762 g (570-4,900 g). In total, 330 patients were premature. Medical closure was applied in 95/597 patients and was successful in 40 of 95 patients. The spontaneous closure rate within 2.3  ±  2.8 months (4 days-2.1 years) was 616/711 (86.6%). Overall, only 8 patients necessitated surgical PDA closure and 38 patients for transcatheter closure. Gestational age and delivery weight had a considerable influence on spontaneous closure. The duration of spontaneous PDA closure was negatively correlated with the gestational age and gestational weight. The duration of spontaneous PDA closure was higher in patients with prematurity and hypothyroidism. Conclusions: The spontaneous closure of the duct may be prolonged in moderate and high-altitude areas. Transcatheter or surgical interventions are rarely needed in the early neonatal period.

Zhang, Wenxin, Yuting Yang, Jing Guo, Fei Hu, Yuan Ma, and Qing Ouyang. Phenothiazine confers neuroprotection via Dpp2/7 in high altitude traumatic brain injury mouse model. High Alt Med Biol. 00:00-00, 2025. Background: Traumatic brain injury (TBI) in high altitude areas can lead to more severe cerebral edema, higher disability, and mortality than in low altitude areas. This study was designed to evaluate the neuroprotective effects and underlying mechanisms of phenothiazine on TBI at high altitudes. Methods: Mice were kept in a hypobaric chamber for 7 days under simulated conditions of 5,000 m above sea level. A controlled cortical impact (CCI) model was established and followed by phenothiazine (chlorpromazine and promethazine) and Dpp2/7 inhibitor UAMC00039 treatment. Hematoxylin-eosin (HE) staining, immunohistochemistry (IHC), western blot, label-free quantitative proteomics, and real-time quantitative polymerase chain reaction (RT-qPCR) assays were performed to assess the effects of phenothiazine and UAMC00039 on TBI. Results: HE staining confirmed that phenothiazine treatment could ameliorate CCI-induced brain injury. IHC, western blot, and RT-qPCR showed that cell apoptosis was alleviated by phenothiazine after high altitude TBI, as proved by the reduction of cleaved-Caspase-3 and increased Bcl-2 expression. Label-free quantitative proteomics, IHC, and western blot showed that phenothiazine significantly upregulated Dpp2/7 after high altitude TBI. Western blot and IHC showed that UAMC00039 treatment significantly reversed phenothiazine-mediated Bcl-2 upregulation and cleaved-Caspase-3 downregulation after high altitude TBI. Conclusions: The results indicated that phenothiazine offers neuroprotective effects via antiapoptosis after high altitude TBI, and this protective mechanism is associated with Dpp2/7-mediated Bcl-2 expression and Caspase-3 cleaving.

Yunden Droma, Masao Ota, Nobumitsu Kobayashi, Michiko Ito, Toshio Kobayashi, and Masayuki Hanaoka. Genetic Associations with the Susceptibility to High-Altitude Pulmonary Edema in the Japanese Population. High Alt Med Biol. 00:00-00, 2025.-High-altitude pulmonary edema (HAPE) is a life-threatening, noncardiogenic pulmonary condition that may occur in individuals rapidly ascending to altitudes higher than 2,500 m above sea level. Exaggerated hypoxia-induced pulmonary hypertension plays a critical role in its pathophysiological mechanism. In addition to environmental factors such as hypoxia and hypobaria at high altitudes, individual genetic predisposition significantly influences HAPE occurrence. Several candidate genes have been proposed based on the pathophysiology of HAPE, particularly involving the hypoxia-induced factor pathway and vasodilators/vasoconstrictors. Over the past two decades, we have investigated the associations between susceptibility to HAPE and these candidate genes, including genes EPAS1 (endothelial Per-ARNT-Sim [PAS] domain protein 1), EGLN1 (egl-9 family hypoxia inducible factor 1), eNOS (endothelial nitric oxide synthase), ACE (angiotensin-converting enzyme), and TIMP3 (tissue inhibitor of metalloproteinase 3) in the Japanese population. This review summarizes the major findings of these studies, shedding light on genetic associations with HAPE in the Japanese population.

Van Ochten, Natalie, Eric W. Rudofker, and William K. Cornwell. Altitude adversities: is it safe for people with cardiovascular disease to travel to moderate-high altitude? High Alt Med Biol. 00:00-00, 2025.-The risk of acute cardiac events increases following acute exposure to hypoxia associated with travel to moderate-high altitudes. Herein, we present seven illustrative cases among lowlanders who presented to our center (1,609 m, equivalent fraction of inspired oxygen [F_IO₂] ∼0.17) with acute cardiac emergencies during travel to moderate-high altitude. We also provide a concise, yet comprehensive, review of the relevant physiology pertaining to the impact of acute hypoxia on cardiovascular physiology and mechanisms by which altitude exposure may increase the risk of adverse events.

Smith, Ben, Nicola Wetherill, and Daniel S. Morris. High-altitude retinopathy presenting as blue spots with prolonged recovery: a case report. High Alt Med Biol. 26:99-101, 2025.-High-altitude retinopathy (HAR) is a common ocular manifestation of high-altitude illness that is usually asymptomatic but can present with reduced or distorted central vision and signs of retinal vascular engorgement and retinal hemorrhages of varying severity. Typically, symptoms are very mild, such as a slight decrease in visual acuity or a small scotoma. There is no treatment for this condition, and most cases resolve spontaneously within 12 weeks without any permanent visual changes. Here we present a case of a previously fit and well 29-year-old female who developed atypical symptoms of "blue spots" in both eyes after ascending to 5,420 m. She descended promptly and was assessed in an emergency ophthalmology clinic in the United Kingdom (UK) upon her return. Her visual recovery was prolonged, which, combined with the presenting symptoms, makes this case atypical and assists in broadening understanding of HAR.

Yu Liu, Zhengyang Zhang, Yongting Luo, Peng An, Jingyi Qi, Xu Zhang, Shuaishuai Zhou, Yongzhi Li, Chong Xu, Junjie Luo, and Jiaping Wang. Product of traditional Chinese medicine longgui yangxinwan protects the human body from altitude sickness damage by reducing oxidative stress and preventing mitochondrial dysfunction. High Alt Med Biol. 26:20-29, 2025. Background: Plateau reaction, caused by high-altitude exposure, results in symptoms like headaches, dyspnea, palpitations, fatigue, shortness of breath, and insomnia due to reduced oxygen levels. Mitochondria are crucial for high-altitude acclimatization as they regulate oxygen metabolism and cellular energy, reducing oxidative stress and maintaining bodily functions. Methods: The study participants were randomly divided into placebo group, Rhodiola group and longgui yangxinwan (Original name: taikong yangxinwan) group, with 20 people in each group. Three groups of subjects were sampled at three time points (PI: pre-intervention; P-D1: high-altitude day 1; P-D7: high-altitude day 7), and blood pressure, blood oxygen, heart rate, hemoglobin, and red blood cell count were measured. The ATP content, mitochondrial DNA copy number, expression of mitochondria-related genes, reactive oxygen species (ROS), glutathione peroxidase (GSH-PX) and malondialdehyde (MDA) levels, and mitochondrial morphology were measured in blood at each time point. Results: Our study results demonstrate that longgui yangxinwan keeps the selected human physiological indicators stable and prevents mitochondrial dysfunction in the high altitude. Mechanically, longgui yangxinwan decreases the level of ROS in human serum, whereas increases the activity of the antioxidant enzyme GSH-PX. At high-altitude day 1 (P-D1) and high-altitude day 7 (P-D7), ROS in the placebo group were 1.5 and 2.2-fold higher than those of the longgui yangxinwan group, respectively. In addition, longgui yangxinwan enhances ATP production capacity, restores the levels of mitochondrial respiratory chain complexes, and effectively maintains mitochondrial morphology and integrity. At P-D1 and P-D7, the ATP levels in the longgui yangxinwan group were 19-fold and 26-fold higher than those in the placebo group, respectively. Conclusions: Our study highlights longgui yangxinwan as a potential drug for protecting humans from high-altitude damage by reducing oxidative stress and preventing mitochondrial dysfunction.

Citherlet, Tom, Antoine Raberin, Giorgio Manferdelli, Nicolas Bourdillon, and Grégoire P Millet. Impact of the menstrual cycle on the cardiovascular and ventilatory responses during exercise in normoxia and hypoxia. High Alt Med Biol. 26:55-62, 2025. Introduction: Ovarian hormones influence several physiological functions in women. This study investigated how the hormonal variations across the menstrual cycle (MC) impact cardiovascular and ventilatory responses during rest and moderate exercise in normobaric hypoxia. Methods: Thirteen eumenorrheic women were tested during the early follicular (Fol1), late follicular (Fol2), and mid-luteal (Lut3) phases with measurement of hormonal levels. Heart rate (HR) variability, blood pressure, and baroreflex sensitivity (BRS) were evaluated at rest in normoxia. Ventilation (VE), peripheral oxygen saturation, and HR were monitored at rest and during moderate-intensity cycling exercise in hypoxia (F_iO₂ = 14%). Results: Despite expected hormone level variations, no significant changes were observed across the MC in HR variability (root mean square of successive differences; 64 (95% confidence interval [47, 81]) at Fol1, 54 [42, 66] at Fol2, 60 [44, 77] ms at Lut3), blood pressure (mean blood pressure; 85 [79, 90]), 87 [81, 93]), 84 [77, 92] mmHg), BRS (26 [17, 36], 28 [20, 35], 23 [17, 29] ms/mmHg), VE (rest: 8.9 [7.9, 9.8], 9.5 [9.0, 9.9], 9.0 [8.1, 9.9]; exercise: 53 [41, 66], 51.1 [36.4, 65.7], 54.4 [34.0, 74.8] l/min), peripheral oxygen saturation (rest: 89.8 [87.4, 92.1], 91.9 [88.7, 95.0], 90.2 [87.8, 92.6]; exercise: 80.5 [77.4, 83.5], 84.4 [80.4, 88.3], 81.9 [78.3, 85.4] %) HR (rest: 69.7 [60.2, 79.1], 70.8 [63.2, 78.3], 70.5 [64.0, 77.0]; exercise: 148 [136, 160], 146 [132, 161], 146 [132, 160] bpm), and cycling efficiency (0.17 [0.16, 0.18], 0.17 [0.13, 0.21], 0.16 [0.15, 0.18] %) (all p > 0.05). Discussion: From a practical point of view, there is no strong evidence of any usefulness of monitoring hormonal variations and the MC phases for women exercising in hypoxia.

Vásquez-Velásquez, Cinthya, Diego Fano-Sizgorich, and Gustavo F. Gonzales. Death risk response of high-altitude resident populations to COVID-19 vaccine: a retrospective cohort study. High Alt Med Biol. 26:37-44, 2025. Background: Peru had one of the highest mortality rates caused by the coronavirus disease 2019 (COVID-19) pandemic worldwide. Vaccination significantly reduces mortality. However, the effectiveness of vaccination might differ at different altitudinal levels. The study aimed to evaluate the effect modification of altitude on the association between vaccination and COVID-19 mortality in Peru. Methodology: A retrospective cohort, using open access databases of deaths, COVID-19 cases, hospitalizations, and vaccination was obtained from the Peruvian Ministry of Health. Deaths due to COVID-19 were evaluated in vaccinated and nonvaccinated patients. Crude (RR) and adjusted relative risks (aRR) were calculated using generalized linear models of Poisson family with robust variances. Models were adjusted for age, sex, pandemic wave, and Human Development Index. To evaluate the interaction by altitude, a stratified analysis by this variable was performed. The variable altitude was categorized as, 0-499 m (828,298 cases), 500-1,499 m (64,735 cases), 1,500-2,499 m (106,572 cases), and ≥2,500 m (179,004 cases). The final sample studied included 1,362,350 cases. Results: The vaccine showed a considerable reduction of death risk with the second (aRR: 0.41, 95% confidence interval [CI]: 0.38-0.44) and third doses (aRR: 0.21, 95% CI: 0.20-0.23). In the adjusted and interaction model, it can be observed that medium and high altitude present a higher risk of death compared to sea level (aRR: 2.58 and 2.03, respectively). Likewise, the two doses' group presents an aRR:1.22 for medium altitude (1,500-2,499 m) and 1.6 for high altitude (≥2,500 m), compared with low-altitude population, suggesting that the action of vaccination at high altitude is altered by the effect of the altitude itself. Conclusions: Altitude might modify the protective effect of SARS-CoV-2 vaccine against COVID-19 death.