The aim of our study was to perform and in-depth analysis of several episodes of regional brain hypoxia detected by monitoring brain partial pressure of oxygen (PtiO2) in which simultaneous measurements of cerebral oxygen extraction fraction (O2EF) suggested a normally perfused or even a hyperemic brain. To gain deeper insight into these episodes, we used the model of tissue hypoxia described by Siggaard-Andersen. In 244 simultaneous measurements, 31 episodes (12.7%) of brain hypoxia (PtiO2 < or = 15 mmHg) were detected simultaneously with an O2EF within the normal range or below the lowest normal percentile. Using Siggaard-Andersen methodology, we classified 6 episodes (19%) as high-affinity hypoxia and 25 (81%) as shunt hypoxia or dysperfusion hypoxia. Siggaard-Andersen's comprehensive classification of tissue hypoxia can be used as an integrative model to build coherent algorithms for diagnosing and managing neurocritical patients that are at risk of brain hypoxia due to either intracranial or extracranial conditions.
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http://dx.doi.org/10.1007/978-3-7091-6738-0_77 | DOI Listing |
Int J Nanomedicine
January 2025
Department of Rehabilitation Medicine, School of Clinical Medicine and The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan, People's Republic of China.
Photodynamic therapy (PDT) is a promising noninvasive tumor treatment modality that relies on generating reactive oxygen species (ROS) and requires an adequate oxygen supply to the target tissue. However, hypoxia is a common feature of solid tumors and profoundly restricts the anti-tumor efficacy of PDT. In recent years, scholars have focused on exploring nanomaterial-based strategies for oxygen supplementation and integrating non-oxygen-consuming treatment approaches to overcome the hypoxic limitations of PDT.
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Department of Nephrology, Affiliated Hospital of Xuzhou Medical University, 221002, China.
Renal interstitial fibrosis (RIF) is a common pathway in chronic kidney disease (CKD) that ultimately leads to end-stage renal failure, worsening both glomerulosclerosis and interstitial fibrosis. Ten percent of the adult population in the world suffers from CKD, and as the ageing population continues to rise, it is increasingly regarded as a global threat-a silent epidemic. CKD has been discovered to be closely associated with both long noncoding RNAs (lncRNAs) and microRNAs (miRNAs), while the precise molecular processes behind this relationship are still unclear.
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Key Laboratory of Tropical Marine Ecosystem and Bioresource, Fourth Institute of Oceanography, Ministry of Natural Resources, Beihai, China.
Over the past few decades, ocean hypoxia has been increasing due to human activities. Hypoxic stress, characterized by a reduced level of dissolved oxygen, is an escalating threat to marine ecosystems, with potentially devastating effects on the viability of endangered species such as the tri-spine horseshoe crab Tachypleus tridentatus. Even though this species is remarkably resilient to low oxygen levels, persistent hypoxia can negatively impact its population's survivability.
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January 2025
Department of Basic Sciences, Faculty of Dentistry, Universidad de Antioquia U de A, Medellín, 050010, Colombia.
The NLRP3 inflammasome, regulated by TLR4, plays a pivotal role in periodontitis by mediating inflammatory cytokine release and bone loss induced by Porphyromonas gingivalis. Periodontal disease creates a hypoxic environment, favoring anaerobic bacteria survival and exacerbating inflammation. The NLRP3 inflammasome triggers pyroptosis, a programmed cell death that amplifies inflammation and tissue damage.
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January 2025
Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, 880 Kitakobayashi, Mibu, Shimotsugagun, Tochigi, 321-0293, Japan.
Although alveolar hyperoxia exacerbates lung injury, clinical studies have failed to demonstrate the beneficial effects of lowering the fraction of inspired oxygen (FO) in patients with acute respiratory distress syndrome (ARDS). Atelectasis, which is commonly observed in ARDS, not only leads to hypoxemia but also contributes to lung injury through hypoxia-induced alveolar tissue inflammation. Therefore, it is possible that excessively low FO may enhance hypoxia-induced inflammation in atelectasis, and raising FO to an appropriate level may be a reasonable strategy for its mitigation.
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