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Poole DC, Bailey DM. Death by nitrogen anoxia: On the integrated physiology of human execution. Exp Physiol 2024; 109:1009-1014. [PMID: 38551897 PMCID: PMC11215468 DOI: 10.1113/ep091836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 03/12/2024] [Indexed: 07/02/2024]
Affiliation(s)
- David C. Poole
- Departments of Kinesiology, Anatomy and PhysiologyKansas State UniversityManhattanKansasUSA
- Department of Anatomy & PhysiologyKansas State UniversityManhattanKansasUSA
| | - Damian M. Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesGlamorganUK
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Tan SZ, Bashir M, Jubouri M, Williams I, Bailey D. Neuroprotection in aortic arch surgery: untold flaws and future directions. THE JOURNAL OF CARDIOVASCULAR SURGERY 2022; 63:254-264. [PMID: 35238526 DOI: 10.23736/s0021-9509.22.12291-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The current paradigm of brain protection in aortic surgery falls short of delivering good outcomes with minimal complications. A renewed understanding of neuroprotective methods and biomarkers to predict brain injury and aortic disease are crucial towards the development of more effective clinical management strategies. A review of current literature was carried out to identify current flaws in our approach to neuroprotection in aortic surgery. Emerging evidence surrounding neuroprotective strategies, biomarkers for brain injury, and biomarkers for predicting aortic disease are evaluated in terms of their impact for future therapeutic approaches. Current literature suggests that the prevailing methods of neuroprotection need renewal. Clinical outcomes associated with deep hypothermic circulatory arrest remain varied. Branch-first and endovascular approaches to aortic repair are particularly promising alternatives. The use of biomarkers to identify and manage brain injury, as well as to diagnose aortic disease in the nonacute and acute settings, would further help to improve our overall paradigm of neuroprotection in aortic surgery. Though much prospective research is still required, the outlook for neuroprotection in aortic surgery is promising. Adopting alternative surgical techniques and exploiting predictive novel biomarkers will help us to gradually eliminate the risk of brain damage in aortic surgery.
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Affiliation(s)
- Sven Z Tan
- Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Mohamad Bashir
- Unit of Vascular and Endovascular Surgery, Health Education and Improvement Wales, Velindre University NHS Trust, Cardiff, UK
| | - Matti Jubouri
- Hull-York Medical School, University of York, York, UK
| | - Ian Williams
- Department of Vascular Surgery, University Hospital of Wales, Cardiff, UK
| | - Damian Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Cardiff, UK -
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Bailey DM. Oxygen, evolution and redox signalling in the human brain; quantum in the quotidian. J Physiol 2018; 597:15-28. [PMID: 30315729 DOI: 10.1113/jp276814] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 09/27/2018] [Indexed: 12/20/2022] Open
Abstract
Rising atmospheric oxygen (O2 ) levels provided a selective pressure for the evolution of O2 -dependent micro-organisms that began with the autotrophic eukaryotes. Since these primordial times, the respiring mammalian cell has become entirely dependent on the constancy of electron flow, with molecular O2 serving as the terminal electron acceptor in mitochondrial oxidative phosphorylation. Indeed, the ability to 'sense' O2 and maintain homeostasis is considered one of the most important roles of the central nervous system (CNS) and probably represented a major driving force in the evolution of the human brain. Today, modern humans have evolved with an oversized brain committed to a continually active state and, as a consequence, paradoxically vulnerable to failure if the O2 supply is interrupted. However, our pre-occupation with O2 , the elixir of life, obscures the fact that it is a gas with a Janus face, capable of sustaining life in physiologically controlled amounts yet paradoxically deadly to the CNS when in excess. A closer look at its quantum structure reveals precisely why; the triplet ground state diatomic O2 molecule is paramagnetic and exists in air as a free radical, constrained from reacting aggressively with the brain's organic molecules due to its 'spin restriction', a thermodynamic quirk of evolutionary fate. By further exploring O2 's free radical 'quantum quirkiness', including emergent (quantum) physiological phenomena, our understanding of precisely how the human brain senses O2 deprivation (hypoxia) and the elaborate redox-signalling defence mechanisms that defend O2 homeostasis has the potential to offer unique insights into the pathophysiology and treatment of human brain disease.
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Affiliation(s)
- Damian Miles Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Wales, UK
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Bailey DM. RETRACTED ARTICLE: The quantum physiology of oxygen; from electrons to the evolution of redox signaling in the human brain. Bioelectron Med 2018; 4:13. [PMID: 32232089 PMCID: PMC7098224 DOI: 10.1186/s42234-018-0014-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 09/19/2018] [Indexed: 12/11/2022] Open
Abstract
Rising atmospheric oxygen (O2) levels provided a selective pressure for the evolution of O2-dependent micro-organisms that began with the autotrophic eukaryotes. Since these primordial times, the respiring mammalian cell has become entirely dependent on the constancy of electron flow with molecular O2 serving as the terminal electron acceptor in mitochondrial oxidative phosphorylation. Indeed, the ability to “sense” O2 and maintain homeostasis is considered one of the most important roles of the central nervous system (CNS) and likely represented a major driving force in the evolution of the human brain. Today, modern humans have evolved with an oversized brain committed to a continually active state and as a consequence, paradoxically vulnerable to failure if the O2 supply is interrupted. However, our pre-occupation with O2, the elixir of life, obscures the fact that it is a gas with a Janus Face, capable of sustaining life in physiologically controlled amounts yet paradoxically deadly to the CNS when in excess. A closer look at its quantum structure reveals precisely why; the triplet ground state diatomic O2 molecule is paramagnetic and exists in air as a free radical, constrained from reacting aggressively with the brain’s organic molecules due to its “spin restriction”, a thermodynamic quirk of evolutionary fate. By further exploring O2’s free radical “quantum quirkiness” including emergent quantum physiological phenomena, our understanding of precisely how the human brain senses O2 deprivation (hypoxia) and the elaborate redox-signaling defense mechanisms that defend O2 homeostasis has the potential to offer unique insights into the pathophysiology and treatment of human brain disease.
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Affiliation(s)
- Damian Miles Bailey
- Neurovascular Research Laboratory, Alfred Russel Wallace Building, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, CF37 4AT UK
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Bailey DM, Rasmussen P, Evans KA, Bohm AM, Zaar M, Nielsen HB, Brassard P, Nordsborg NB, Homann PH, Raven PB, McEneny J, Young IS, McCord JM, Secher NH. Hypoxia compounds exercise-induced free radical formation in humans; partitioning contributions from the cerebral and femoral circulation. Free Radic Biol Med 2018; 124:104-113. [PMID: 29859345 DOI: 10.1016/j.freeradbiomed.2018.05.090] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 05/19/2018] [Accepted: 05/29/2018] [Indexed: 12/19/2022]
Abstract
This study examined to what extent the human cerebral and femoral circulation contribute to free radical formation during basal and exercise-induced responses to hypoxia. Healthy participants (5♂, 5♀) were randomly assigned single-blinded to normoxic (21% O2) and hypoxic (10% O2) trials with measurements taken at rest and 30 min after cycling at 70% of maximal power output in hypoxia and equivalent relative and absolute intensities in normoxia. Blood was sampled from the brachial artery (a), internal jugular and femoral veins (v) for non-enzymatic antioxidants (HPLC), ascorbate radical (A•-, electron paramagnetic resonance spectroscopy), lipid hydroperoxides (LOOH) and low density lipoprotein (LDL) oxidation (spectrophotometry). Cerebral and femoral venous blood flow was evaluated by transcranial Doppler ultrasound (CBF) and constant infusion thermodilution (FBF). With 3 participants lost to follow up (final n = 4♂, 3♀), hypoxia increased CBF and FBF (P = 0.041 vs. normoxia) with further elevations in FBF during exercise (P = 0.002 vs. rest). Cerebral and femoral ascorbate and α-tocopherol consumption (v < a) was accompanied by A•-/LOOH formation (v > a) and increased LDL oxidation during hypoxia (P < 0.043-0.049 vs. normoxia) implying free radical-mediated lipid peroxidation subsequent to inadequate antioxidant defense. This was pronounced during exercise across the femoral circulation in proportion to the increase in local O2 uptake (r = -0.397 to -0.459, P = 0.037-0.045) but unrelated to any reduction in PO2. These findings highlight considerable regional heterogeneity in the oxidative stress response to hypoxia that may be more attributable to local differences in O2 flux than to O2 tension.
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Affiliation(s)
- Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, UK.
| | - Peter Rasmussen
- Department of Anesthesia, Rigshospitalet, University of Copenhagen, Denmark
| | - Kevin A Evans
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, UK
| | - Aske M Bohm
- Department of Anesthesia, Rigshospitalet, University of Copenhagen, Denmark
| | - Morten Zaar
- Department of Anesthesia, Rigshospitalet, University of Copenhagen, Denmark
| | - Henning B Nielsen
- Department of Anesthesia, Rigshospitalet, University of Copenhagen, Denmark
| | - Patrice Brassard
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada
| | - Nikolai B Nordsborg
- Faculty of Science, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | | | - Peter B Raven
- Department of Integrative Physiology and Anatomy, University of North Texas Health Science Center, TX, USA
| | - Jane McEneny
- Centre for Public Health, Queen's University Belfast, Northern Ireland, UK
| | - Ian S Young
- Centre for Public Health, Queen's University Belfast, Northern Ireland, UK
| | - Joe M McCord
- Department of Medicine, Division of Pulmonary Science and Critical Care Medicine, University of Colorado at Denver, Denver, CO, USA
| | - Niels H Secher
- Department of Anesthesia, Rigshospitalet, University of Copenhagen, Denmark
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Bailey DM, Willie CK, Hoiland RL, Bain AR, MacLeod DB, Santoro MA, DeMasi DK, Andrijanic A, Mijacika T, Barak OF, Dujic Z, Ainslie PN. Surviving Without Oxygen: How Low Can the Human Brain Go? High Alt Med Biol 2017; 18:73-79. [DOI: 10.1089/ham.2016.0081] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Affiliation(s)
- Damian M. Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Glamorgan, United Kingdom
- Faculty of Medicine, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada
| | - Christopher K. Willie
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada
| | - Ryan L. Hoiland
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada
| | - Anthony R. Bain
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada
| | - David B. MacLeod
- Human Pharmacology and Physiology Laboratory, Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina
| | - Maria A. Santoro
- Human Pharmacology and Physiology Laboratory, Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina
| | - Daniel K. DeMasi
- Human Pharmacology and Physiology Laboratory, Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina
| | - Andrea Andrijanic
- School of Management, Libertas International University, Zagreb, Croatia
| | | | - Otto F. Barak
- School of Medicine, University of Split, Split, Croatia
- Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia
| | - Zeljko Dujic
- School of Medicine, University of Split, Split, Croatia
| | - Philip N. Ainslie
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Glamorgan, United Kingdom
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada
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