Background And Objectives: Breathing increased fractional oxygen concentration (FiO2) is recommended for the treatment of tissue ischaemia.
Methods: The theoretical benefits of increasing FiO2 on tissue oxygenation were evaluated using standard physiological equations. Assuming constant oxygen consumption by tissues throughout the length of a capillary, the oxygen content at 20 arbitrary points along a capillary was calculated. Using mathematical representations of the haemoglobin dissociation curve and an iterative approach to include the dissolved oxygen component of oxygen content, the oxygen partial pressure (PO2) profile along a capillary was estimated.
Results: High FiO2 concentrations cause large increases in PO2 at the arteriolar end of capillaries but these large PO2 values, caused by the extra dissolved oxygen, rapidly decline along the capillary. At the venular end of the capillary (the area of tissue most likely to be hypoxic), breathing oxygen causes only a modest improvement in PO2.
Conclusion: Increasing FiO2 to treat tissue hypoxia has clear benefits, but a multimodal approach to management is required.
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http://dx.doi.org/10.1097/EJA.0b013e3283329dc4 | DOI Listing |
Fish Physiol Biochem
January 2025
Department of Biology, Ecology and Earth Science, University of Calabria, Rende, Italy.
Under low O, the heart of Carassius auratus (goldfish) shows an enhanced hemodynamics. This is observed in ex vivo cardiac preparations from animals acclimated to both normoxia and short-term (4 days) moderate hypoxia and perfused for 90 min with a hypoxic medium. Under short-term hypoxia, this is associated with a higher ventricular muscularity and an expanded mitochondrial compartment.
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Department of Respiratory and Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, People's Republic of China.
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January 2025
Department of Respiratory medicine, Taian 88 Hospital, Taian, 271000, People's Republic of China.
Recent empirical investigations reinforce the understanding of a profound interconnection between metabolic functions and Obstructive Sleep Apnea-hypopnea Syndrome (OSAHS). This study identifies distinctive miRNA signatures in OSAHS with Metabolic Syndrome (Mets) patients from healthy subjects, that could serve as diagnostic biomarkers or describe differential molecular mechanisms with potential therapeutic implications. In this study, OSAHS with MetS patients showed significantly higher Apnea Hyponea Index(AHI), but lower oxygen desaturation index(ODI 4/h) and minimum pulse oxygen saturation(SpO).
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January 2025
Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
Observing quantum mechanical characteristics in biological processes is a surprising and important discovery. One example, which is gaining more experimental evidence and practical applications, is the effect of weak magnetic fields with extremely low frequencies on cells, especially cancerous ones. In this study, we use a mathematical model of ROS dynamics in cancer cells to show how ROS oscillatory patterns can act as a resonator to amplify the small effects of the magnetic fields on the radical pair dynamics in mitochondrial Complex III.
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January 2025
Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou, 215006, Jiangsu, China.
Acyl-CoA oxidase 1 (ACOX1), a member of the acyl-coenzyme A oxidase family, is considered a crucial regulator whose dysregulation is implicated in the occurrence and progression of various cancers. This study aims to elucidate the impact of ACOX1 in CRC, shedding light on its potential as a therapeutic target. Through analysis of the GEO dataset, it was found that ACOX1 is significantly downregulated in colorectal cancer (CRC), and this lower expression level is associated with a worse prognosis.
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