The present study investigates whether under conditions of successive hypoxic exposures pretreatment with mild (15% O(2)) or moderate (10% O(2)) hypoxia, protects hippocampal neurones against damage induced by severe (3% O(2)) hypoxia. The ultrastructural findings were also correlated with regional superoxide dismutase (SOD) activity changes. In unpretreated rats severe hypoxia induced ultrastructural changes consistent with the aspects of delayed neuronal death (DND). However, in preexposed animals hippocampal damage was attenuated in an inversely proportional way with the severity of the hypoxic pretreatment. The ultrastructural hypoxic tolerance findings were also closely related to increased regional SOD activity levels. Thus the activation of the endogenous antioxidant defense by hypoxic preconditioning, protects against hippocampal damage induced by severe hypoxia. The eventual contribution of increased endogenous adenosine and/or reduced excitotoxicity to induce hypoxic tolerance is discussed.
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http://dx.doi.org/10.1016/0006-8993(95)01548-5 | DOI Listing |
Clin Toxicol (Phila)
January 2025
National Poisons Information Service, Cardiff Unit, University Hospital Llandough, Penarth, UK.
Introduction: Ibogaine is a psychoactive alkaloid derived from the root bark of the West African shrub . It is not licensed in the United Kingdom but is used by individuals to alleviate drug or alcohol use.
Methods: A retrospective analysis of telephone enquiries involving ibogaine between 1 January 2012 and 31 December 2022 to the United Kingdom National Poisons Information Service was performed.
Future Sci OA
December 2025
Department of Clinical Biostatistics, Graduate School of Medical and Dental Sciences, Institute of Science Tokyo, Tokyo, Japan.
Background: Patients with severe coronavirus disease 2019 (COVID-19) have been reported to show hypoxia without displaying typical clinical signs or symptoms, called "happy hypoxia." To explore the potential of happy hypoxia as a distinctive symptom of COVID-19, we compared vital signs in the triage phase between patients with and without COVID-19.
Methods: We retrospectively identified emergency patients with and without COVID-19 admitted to Rakuwakai Marutamachi Hospital, Kyoto, Japan, between January 2021 and December 2021.
J Exp Biol
January 2025
Department of Ocean Sciences, Memorial University of Newfoundland and Labrador, St. John's, NL. A1C 5S7, Canada.
With climate change, fish are facing rising temperatures, an increase in the frequency and severity of heat waves and hypoxia, sometimes concurrently. However, only limited studies have examined the combined effects of increases in temperature and hypoxia on fish physiology and survival. We measured the cardiorespiratory physiology of 12°C-acclimated Atlantic salmon when exposed acutely to normoxia [100% air saturation (sat.
View Article and Find Full Text PDFFront Physiol
January 2025
Centre de Recherche de l'Institute Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, QC, Canada.
Introduction: In high-altitude cities located above 2,500 m, hospitals face a concerning mortality rate of over 50% among intensive care unit (ICU) patients with acute respiratory distress syndrome (ARDS). This elevated mortality rate is largely due to the absence of altitude-specific medical protocols that consider the unique physiological adaptations of high-altitude residents to hypoxic conditions. This study addresses this critical gap by analyzing demographic, clinical, sex-specific, and preclinical data from ICUs in Bogotá, Colombia (2,650 m) and El Alto, Bolivia (4,150 m).
View Article and Find Full Text PDFBrain Behav Immun Health
December 2024
Department of Systems Medicine, University of Rome "Tor Vergata", 00133, Rome, Italy.
Background: Interleukin-6 (IL-6) represents one of the main molecules involved in inflammatory responses, which can be altered in either patients with cognitive impairment or obstructive sleep apnea (OSA). The present study aimed to evaluate serum IL-6 levels and cognitive performance in patients with severe OSA (Apnea-Hypopnea Index - AHI >30/h).
Methods: Thirty patients with severe OSA were compared to 15 controls similar in age, sex, and Body Mass Index.
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