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Introduction: This study aimed to investigate the effects of normobaric hypoxia (NH) and hypobaric hypoxia (HH) on associative memory performance for emotionally valenced stimuli., Methods: Two experiments were conducted. In Study 1, n = 18 undergraduates performed an associative memory task under three NH conditions (FiO 2 = 20.9 %, 15.1 %, 13.6 %) using a tent with a hypoxic generator. In Study 2, n = 20 participants were assessed in a field study at various altitudes on the Himalayan mountains, including the Pyramid Laboratory (5000 m above sea level), using functional Near-Infrared Spectroscopy (fNIRS) and behavioral assessments., Results: Study 1 revealed no significant differences in recognition accuracy across NH conditions. However, Study 2 showed a complex relationship between altitude and memory for emotionally valenced stimuli. At lower altitudes, participants more accurately recognized emotional stimuli compared to neutral ones, a trend that reversed at higher altitudes. Brain oxygenation varied with altitude, indicating adaptive cognitive processing, as revealed by fNIRS measurements., Conclusions: These findings suggest that hypoxia affects associative memory and emotional processing in an altitude-dependent manner, highlighting adaptive cognitive mechanisms. Understanding the effects of hypobaric hypoxia on cognition and memory can help develop strategies to mitigate its impact in high-altitude and hypoxic environments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

This study aimed to evaluate changes in lung function assessed by spirometry and blood gas content in healthy high-altitude sojourners during a trek in the Himalayas. A group of 19 Italian adults (11 males and 8 females, mean age 43 ± 15 years, and BMI 24.2 ± 3.7 kg/m 2 ) were evaluated as part of a Mount Everest expedition in Nepal. Spirometry and arterial blood gas content were evaluated at baseline in Kathmandu (≈1400 m), at the Pyramid Laboratory - Observatory (peak altitude of ≈5000 m), and on return to Kathmandu 2-3 days after arrival at each site. All participants took 250 mg of acetazolamide per os once daily during the ascent. We found that arterial hemoglobin saturation, O 2 and CO 2 partial pressures, and the bicarbonate level all decreased (in all cases, p < 0.001 with R 2 =0.70-0.90), while pHa was maintained stable at the peak altitude. Forced vital capacity (FVC) remained stable, while forced expiratory volume in 1 s (FEV1) decreased (p = 0.010, n 2 p =0.228), resulting in a lower FEV1/FVC ratio (p < 0.001, n 2 p =0.380). The best predictor for acute mountain sickness was the O 2 partial pressure at the peak altitude (p = 0.004, R 2 =0.39). Finger pulse oximetry overestimated peripheral saturation relative to arterial saturation. We conclude that high-altitude hypoxia alters the respiratory function and the oxygen saturation of the arterial blood hemoglobin. Additionally, air rarefaction and temperature reduction, favoring hypoxic bronchoconstriction, could affect respiration. Pulse oximetry seems not enough to assist medical decisions at high altitudes., Competing Interests: Conflicts of Interest The authors declare no conflicts of interest. No author has any fiduciary relationships or duties to the sponsors., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The carotid body (CB) is a neuroepithelial tissue consisting of O 2 -sensitive glomus cells that constantly scan the arterial blood for O 2 and generate a discharge as an inverse function of O 2 content. Aging is a cumulative result of decreased O 2 supply paralleled by a decreased O 2 tissue demand and oxidative damage to cells derived from aerobic metabolism. Here we studied how CB affects the aging process. This is a study of CB ultrastructural morphometry and immunohistochemical expression of proteins underlying CB responsiveness. The study was based on human CBs obtained from cadavers of people who died due to traumatic events in young and old age. The study was supplemented by investigations of CBs obtained from young and old rats subjected to chronic normoxic and hypoxic conditions. We found changes in the old normoxic CBs akin to the effects of chronic hypoxia such as enhanced extracellular matrix, reduced synaptic contacts between glomus cells, fewer glomus cells, secretory vesicles, and mitochondria. These changes were accompanied by enhanced expressions of hypoxia-inducible factor one-alpha (HIF-1α), vascular endothelial growth factor (VEGF), and nitric oxide synthase (NOS2). We conclude that hypoxia and aging share a common background consisting of deficient O 2 tissue supply, mitochondrial dysfunction, and a limited ability to deal with increased cellular oxidative stress. Aging leads to adaptative reductions in CB responsiveness to hypoxia shifting the chemosensory setpoint upward. We submit that the attenuated CB sensitivity at old age may be tantamount to "physiological denervation" leading to a gradual loss of the chemosensing role in the prevention of tissue hypoxia by increasing lung ventilation., Competing Interests: Conflicts of Interest The authors declare no conflict of interest concerning this article., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Prostaglandin (PG)E 2 seems to promote tumor proliferation by regulating cell growth, inhibiting apoptosis, promoting angiogenesis, and suppressing host immune surveillance of cancer cells. The suppression of prostaglandins biosynthesis is thought to be the main molecular mechanism for non-steroidal anti-inflammatory drugs antineoplastic effect. Yet the relationship between PGE 2 and human renal cell carcinoma remains unclear. The aim of our study is to evaluate the PGE 2 content in human renal parenchyma and Renal Cell Carcinoma. The study was conducted on 20 consecutive patients undergoing radical nephrectomy for Renal Cell Carcinoma. In the normal renal parenchyma and in the neoplastic renal tissue the PGE 2 level was 83.43 ± 5.89 pg/mg and 289.67 ± 22.2 pg/mg, respectively (P < 0.0001). There was no relationship between PGE 2 content and Renal Cell Carcinoma dimension, Fuhrman grade, pathological-Tumor-Node and Metastasis (pTNM) stage and histological subtype. The PGE 2 over-content in neoplastic renal tissue suggests a role of PGE 2 in development and progression of renal carcinoma., (Copyright © 2019 Elsevier Inc. All rights reserved.)