OBJECTIVE: Tibetan patients undergoing total knee arthroplasty (TKA) have greater fluctuations in perioperative haemoglobin levels and blood hypercoagulability. This study was to investigate whether ethnicity and altitude affect perioperative blood loss and the risk of complications after TKA.
METHODS: We retrospectively enrolled 1,116 patients undergoing TKA for knee osteoarthritis at our hospital between January 2016 and September 2021. We divided patients into four groups according to whether they were of Tibetan or Han ethnicity and whether they lived above or below 2500 m above sea level. Primary outcomes were total, intraoperative, and hidden blood losses, while secondary outcomes were complications and homologous transfusion. Factors associated with increased blood loss were analyzed by multivariate regression.
RESULTS: Total blood loss was higher among patients residing at high altitude compared with lower altitude, whether they were of Han (794.6 mL vs. 667.2 mL, P = 0.020) or Tibetan (904.4 mL vs. 663.8 mL, P < 0.001). Total blood loss was similar between the two ethnic groups at the same altitude. Altitude, but not Tibetan ethnicity, remained associated with increased blood loss after being analyzed by multivariate regression. Complications among the four groups were generally similar, although the frequency of calf muscular venous thrombosis was higher among Tibetan patients, while the frequency of blood transfusion was higher among Han subjects.
CONCLUSIONS: Our findings indicate that residence at high altitude, but not ethnicity, may contribute to increased total blood loss during TKA. Thrombotic complications were more frequent among Tibetan than Han patients.

UNASSIGNED: RESLES (Reversible splenial lesion syndrome) can be observed secondary to various diseases, and intramyelinic edema may play a crucial role in the pathogenesis of SCC (Splenium of the corpus callosum). Some studies have suggested that hypoxic-ischaemic encephalopathy may constitute a risk factor for SCC lesions. However, the potential impact of high-altitude environments on SCC, especially during chronic exposure, remain obscure.
UNASSIGNED: Our study included 19 patients who satisfied the diagnostic criteria of RESLES at high altitudes. Ten low-altitude patients with RESLES were included as controls. All participants received MRI (Magnetic resonance imaging) scans twice. Routine blood tests, liver, kidney and thyroid function, coagulation function, electrolytes and vitamins were detected during hospitalization and before discharge. In addition, the patients were followed up in May 2023.
UNASSIGNED: Hypoxic environments at high altitudes may increase the risk of RESLES. The two groups showed different clinical symptoms. High-altitude patients had significantly higher CRP levels than low-altitude patients. The lesion size in high-altitude patients showed a positive correlation with SaO2 levels. However, the patients at low altitudes had positive correlation trends between lesion size and several inflammatory markers (WBC, NEU and CRP). All patients had a benign prognosis that may not be affected by the use of prednisone acetate.
UNASSIGNED: Hypoxic environments at high altitudes may play a role in the aetiology of RESLES. Additionally, RESLES is a reversible disease and the administration of glucocorticoids may be dispensable for its treatment.

BACKGROUND: Individuals ascending to elevations above 2500 m are at risk of developing altitude illness. We sought to establish the incidence and to determine what risk factors, if any, increased the likelihood of developing acute mountain sickness (AMS) in adolescents at Philmont Scout Ranch (PSR) in Cimarron, New Mexico. PSR, with elevations ranging from 2011 to 3792 m, attracts thousands of adolescent participants each year, many of whom arrive from lower elevations with little or no experience ascending to high altitude.
METHODS: We conducted a prospective observational study of adolescent participants aged 14 to 19 years who ascended to a minimum of 3000 m while trekking from June to July 2021. Prior to the start of each participant\'s trek, pretrek survey data were obtained at PSR\'s basecamp (2011 m). During the trek at 3048 m, the Lake Louise AMS score was used to diagnose AMS.
RESULTS: The incidence of AMS in our study was 13.7%. Participants reporting a history of daily headaches had more than four times the risk of developing AMS. A history of gastrointestinal problems carried three times the risk of developing AMS, and a prior history of AMS increased the risk of developing AMS by 44%.
CONCLUSIONS: Our findings enhance our understanding of AMS risk in adolescents and may provide guidance to youth for developing AMS. For individuals with a history of headaches or gastrointestinal problems or a prior history of AMS, there may be an opportunity to reduce the risk of developing AMS.

UNASSIGNED: Depressive symptoms have become a public health issue of common concern in countries all over the world, and have many negative impacts on university students\' study and life. Depressive symptoms are influenced by many factors, including sugar-sweetened beverages (SSBs) consumption and duration of physical activity. However, no study has been conducted on the association between sugar-sweetened beverage consumption, duration of physical exercise, and depressive symptoms among Tibetan university students at high altitudes.
UNASSIGNED: In this study, a self-assessment survey of SSBs consumption, duration of physical exercise, and depressive symptoms was conducted on 6,259 (2,745 boys, 43.86%) Tibetan university students aged 19-22 years in Lhasa and Ganzi areas, China, using stratified whole population sampling. The associations were also analyzed using one-way analysis of variance, binary logistic regression analysis, and ordered logistic regression analysis in the generalised linear model.
UNASSIGNED: The proportions of mild depression symptoms, moderate depression symptoms, and major depressive symptoms among Tibetan boys university students in high-altitude areas of China were 18.0, 22.9, and 1.5%, respectively; the proportions of girls students were 20.1, 21.9, and 1.5%, respectively, 1.5%, and the differences in the detection rates of depressive symptoms between sex were statistically significant (χ 2 value = 14.253, p < 0.01). Ordered logistic regression analyses showed that using duration of physical exercise >60 min/d and SSBs ≤1 times/week as the reference group, the duration of physical exercise <30 min/d and SSBs ≥5 times/week groups had the highest risk of developing depressive symptoms was the highest risk (OR = 6.98, 95% CI: 5.05-9.65; p < 0.001).
UNASSIGNED: This study confirmed that there was a positive association between SSBs consumption and depressive symptoms and a negative association between the duration of physical exercise and depressive symptoms among Tibetan university students at high altitudes in China. In the future, SSBs consumption should be effectively controlled and the duration of physical exercise should be increased to reduce the occurrence of depressive symptoms and promote the physical and mental health of Tibetan university students in high-altitude areas.

Human-wildlife conflict studies of high-altitude areas are rare due to budget constraints and the challenging nature of research in these remote environments. This study investigates the prevalence and increasing trend of human-wildlife conflict (HWC) in the mountainous Gaurishankar Conservation Area (GCA) of Nepal, with a specific focus on leopard (Panthera pardus) and Himalayan black bear (Ursus thibetanus laniger). The study analyzes a decade of HWC reports and identifies goats as the livestock most targeted by leopards. The Dolakha district of GCA received the highest number of reports, highlighting the need for mitigation measures in the area. In GCA, livestock attacks accounted for 85% of compensation, with the remaining 15% for human injuries. We estimate that the number of reported wildlife attacks grew on average by 33% per year, with an additional increase of 57 reports per year following the implementation of a new compensation policy during BS 2076 (2019 AD). While bear attacks showed no significant change post-rule alteration, leopard attack reports surged from 1 to 60 annually, indicating improved compensation may have resulted in increased leopard-attack reporting rates. The findings emphasize the economic impact of HWC on local communities and suggest strategies such as increasing prey populations, promoting community education and awareness, enhancing alternative livelihood options, developing community-based insurance programs, and implementing secure enclosures (corrals) to minimize conflicts and foster harmonious coexistence. This research addresses a knowledge gap in HWC in high-altitude conservation areas like the GCA, providing valuable insights for conservation stakeholders and contributing to biodiversity conservation and the well-being of humans and wildlife.

UNASSIGNED: Sleep-disordered breathing (SDB) and gas exchange disorders are common in patients with cystic fibrosis (CF). Currently, the impact of the disease on sleep patterns in patients living at high altitude and the relationship of these patterns to lung function are largely unknown. The aim of this study was to determine the frequency of SDB in children with CF aged 6-18 years and the relationship between SDB and lung function (FEV1).
UNASSIGNED: This is an analytical cross-sectional study of children aged 6-18 years diagnosed with CF. Spirometry before and after bronchodilators and polysomnography with capnography were performed. Descriptive analysis of qualitative and continuous variables was performed. Spearman\'s correlation coefficient was used to determine the correlation between polysomnogram and lung function (FEV1).
UNASSIGNED: Twenty-four patients with CF were included. The mean age was 10.5 ± 3.1 years and 62.5% were male. Nine children had bronchiectasis on chest CT. The median absolute baseline FEV1 was 1,880 (1,355-2,325) ml and 98% (83%-110%) of predicted value. No significant difference in FEV1% was observed between subjects with obstructive sleep apnea (OSA) and those without OSA (P = 0.56). The prevalence of OSA was 66.7% in children younger than 13 years and 40% in children older than 13 years. The Spearman correlation coefficient between FEV1 and percentage of total sleep time with saturation less than 90% (T90) was rho -0.52 (p-value = 0.018), and between FEV1 and percentage of total sleep time with saturation less than 85% (T85) was statistically significant with rho -0.45 (p-value = 0.041). A positive correlation was observed between FEV1 and SpO2 during sleep with rho 0.53 and a statistically significant p-value (0.014).
UNASSIGNED: A high prevalence of sleep apnea was found in children with CF living at high altitude, with a negative correlation between FEV1 and T90 and T85 oxygenation indices, and a positive correlation between FEV1 and SpO2 during sleep.

BACKGROUND: Chronic endometritis (CE) is a persistent inflammation of the uterine lining. Although it has a minimal clinical presentation, CE adversely affects the reproductive ability of women. The aims of this study were to detect pathological endometrial patterns in D&C biopsies and to evaluate chronic endometritis in patients living in a high-altitude area (1800 m above sea level) in order to determine the clinical pathological features and prevalence.
METHODS: A cross-sectional study conducted at King Faisal Maternity Hospital included 100 samples of D&C biopsies from women complaining of various gynecological symptoms not due to gestational causes. The biopsies underwent tissue processing, H&E staining, and CD138 detection. Blood samples were taken for serological detection of infectious diseases, complete blood count, and chemical parameters.
RESULTS: The mean age of women in the study with CE was 48.5 ± 8.5 years, and that of those without CE was 46.9 ± 9.7 years. The most common complaints were abnormal uterine bleeding, accounting for 83%. CE was present in 8% of cases, and there was a nonsignificant difference in hematological parameters between women with CE and those with other pathological diagnoses. There were also nonsignificant differences in chemical parameters, except for FSH and LH levels, which showed a significant difference, with p-values of 0.05 and 0.02, respectively. It can be concluded that the most common gynecological complaint of women in this study was abnormal uterine bleeding.
CONCLUSIONS: The most commonly diagnosed pathological endometrial disorder in D&C biopsies was disordered proliferative endometrium, followed by endometrial polyps and endometrial hyperplasia. All of these are usually associated with hormonal disturbance, which appeared to be very common in the women in this study. The prevalence of chronic endometritis detected in our study was 8%, which is relatively high.

High-altitude acclimatization refers to the physiological adjustments and adaptation processes by which the human body gradually adapts to the hypoxic conditions of high altitudes after entering such environments. This study analyzed three mRNA expression profile datasets from the GEO database, focusing on 93 healthy residents from low altitudes (≤1400 m). Peripheral blood samples were collected for analysis on the third day after these individuals rapidly ascended to higher altitudes (3000-5300 m). The analysis identified significant differential expression in 382 genes, with 361 genes upregulated and 21 downregulated. Further, gene ontology (GO) annotation analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis indicated that the top-ranked enriched pathways are upregulated, involving blood gas transport, erythrocyte development and differentiation, and heme biosynthetic process. Network analysis highlighted ten key genes, namely, SLC4A1, FECH, EPB42, SNCA, GATA1, KLF1, GYPB, ALAS2, DMTN, and GYPA. Analysis revealed that two of these key genes, FECH and ALAS2, play a critical role in the heme biosynthetic process, which is pivotal in the development and maturation of red blood cells. These findings provide new insights into the key gene mechanisms of high-altitude acclimatization and identify potential biomarkers and targets for personalized acclimatization strategies.

UNASSIGNED: The study aimed to explore the risk factors for hyperuricemia (HUA) in the Naxi ethnic population residing in high-altitude areas of Yunnan, China, and assess the clinical value of the triglyceride/high-density lipoprotein cholesterol (TG/HDL-c) ratio as a diagnostic marker.
UNASSIGNED: In this cross-sectional study, clinical data were collected from the health checkup population in the People\'s Hospital of Yulong Naxi Autonomous County, Yunnan Province, from January 2021 to January 2023. Participants were divided into quartiles based on the TG/HDL-c ratio (Q1, Q2, Q3, and Q4) for group analysis using chi-square tests, t-tests, and rank sum tests. Logistic regression analysis and linear regression models were employed to further investigate the correlation between the prevalence of hyperuricemia and TG/HDL-c ratio in this high-altitude Naxi population.
UNASSIGNED: A total of 714 participants from the health checkup population were included in the study, of whom 61.5% were male participants and 38.5% were female participants, and the average age was 41.21 ± 11.69 years. The mean uric acid level was 388.51 ± 99.24. After correcting for confounding factors, TG/HDL-c, serum creatinine (Scr), blood urea nitrogen (BUN), triglyceride (TG), high-density lipoprotein cholesterol (HDL-c), red blood cells (RBCs), and hemoglobin (Hb) showed a positive correlation with blood uric acid. Further analysis involved categorizing the TG/HDL-c ratio from a continuous variable to a categorical variable using quartiles. The fully adjusted model showed results that were consistent with the trend observed in the continuous variable analysis when considering the TG/HDL-c ratio as a categorical variable. In addition, in all unadjusted and adjusted models, the serum uric acid (SUA) levels in the high TG/HDL-c ratio group were significantly higher than those in the low TG/HDL-c ratio group (trend p < 0.001). Further linear relationship analysis indicated that after adjusting for covariates, there was an approximate linear relationship between the TG/HDL-c and SUA levels, with a coefficient (β) of 5.421.
UNASSIGNED: The prevalence of hyperuricemia is greater in high-altitude areas of Yunnan, showing a nearly linear positive correlation with the TG/HDL-c ratio. Monitoring TG/HDL-c levels may benefit patients with hyperuricemia.

Papua New Guinea (PNG) hosts distinct environments mainly represented by the ecoregions of the Highlands and Lowlands that display increased altitude and a predominance of pathogens, respectively. Since its initial peopling approximately 50,000 years ago, inhabitants of these ecoregions might have differentially adapted to the environmental pressures exerted by each of them. However, the genetic basis of adaptation in populations from these areas remains understudied. Here, we investigated signals of positive selection in 62 highlanders and 43 lowlanders across 14 locations in the main island of PNG using whole-genome genotype data from the Oceanian Genome Variation Project (OGVP) and searched for signals of positive selection through population differentiation and haplotype-based selection scans. Additionally, we performed archaic ancestry estimation to detect selection signals in highlanders within introgressed regions of the genome. Among highland populations we identified candidate genes representing known biomarkers for mountain sickness (SAA4, SAA1, PRDX1, LDHA) as well as candidate genes of the Notch signaling pathway (PSEN1, NUMB, RBPJ, MAML3), a novel proposed pathway for high altitude adaptation in multiple organisms. We also identified candidate genes involved in oxidative stress, inflammation, and angiogenesis, processes inducible by hypoxia, as well as in components of the eye lens and the immune response. In contrast, candidate genes in the lowlands are mainly related to the immune response (HLA-DQB1, HLA-DQA2, TAAR6, TAAR9, TAAR8, RNASE4, RNASE6, ANG). Moreover, we find two candidate regions to be also enriched with archaic introgressed segments, suggesting that archaic admixture has played a role in the local adaptation of PNG populations.