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Yin H, Chen Z, Zhao H, Huang H, Liu W. Noble gas and neuroprotection: From bench to bedside. Front Pharmacol 2022; 13:1028688. [PMID: 36532733 PMCID: PMC9750501 DOI: 10.3389/fphar.2022.1028688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 11/03/2022] [Indexed: 07/26/2023] Open
Abstract
In recent years, inert gases such as helium, argon, and xenon have gained considerable attention for their medical value. Noble gases present an intriguing scientific paradox: although extremely chemically inert, they display a remarkable spectrum of clinically useful biological properties. Despite a relative paucity of knowledge about their mechanisms of action, some noble gases have been used successfully in clinical practice. The neuroprotection elicited by these noble gases has been investigated in experimental animal models of various types of brain injuries, such as traumatic brain injury, stroke, subarachnoid hemorrhage, cerebral ischemic/reperfusion injury, and neurodegenerative diseases. Collectively, these central nervous system injuries are a leading cause of morbidity and mortality every year worldwide. Treatment options are presently limited to thrombolytic drugs and clot removal for ischemic stroke, or therapeutic cooling for other brain injuries before the application of noble gas. Currently, there is increasing interest in noble gases as novel treatments for various brain injuries. In recent years, neuroprotection elicited by particular noble gases, xenon, for example, has been reported under different conditions. In this article, we have reviewed the latest in vitro and in vivo experimental and clinical studies of the actions of xenon, argon, and helium, and discuss their potential use as neuroprotective agents.
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Affiliation(s)
- Haiying Yin
- Department of Anesthesiology and Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Zijun Chen
- Department of Anesthesiology and Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Hailin Zhao
- Division of Anesthetics, Department of Surgery and Cancer, Pain Medicine and Intensive Care, Faculty of Medicine, Imperial College London, Chelsea and Westminster Hospital, London, United Kingdom
| | - Han Huang
- Department of Anesthesiology and Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Wenwen Liu
- Department of Anesthesia Nursing, West China Second University Hospital, Sichuan University/West China School of Nursing, Ministry of Education, Sichuan University and Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Chengdu, China
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2
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Davidson JO, Gonzalez F, Gressens P, Gunn AJ. Update on mechanisms of the pathophysiology of neonatal encephalopathy. Semin Fetal Neonatal Med 2021; 26:101267. [PMID: 34274259 DOI: 10.1016/j.siny.2021.101267] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Therapeutic hypothermia is now well established to significantly improve survival without disability after neonatal encephalopathy (NE). To further improve outcomes, we need to better understand the mechanisms of brain injury. The central finding, which offers the potential for neuroprotective and neurorestorative interventions, is that brain damage after perinatal hypoxia-ischemia evolves slowly over time. Although brain cells may die during profound hypoxia-ischemia, even after surprisingly severe insults many cells show transient recovery of oxidative metabolism during a "latent" phase characterized by actively suppressed neural metabolism and activity. Critically, after moderate to severe hypoxia-ischemia, this transient recovery is followed after ~6 h by a phase of secondary deterioration, with delayed seizures, failure of mitochondrial function, cytotoxic edema, and cell death over ~72 h. This is followed by a tertiary phase of remodeling and recovery. This review discusses the mechanisms of injury that occur during the primary, latent, secondary and tertiary phases of injury and potential treatments that target one or more of these phases. By analogy with therapeutic hypothermia, treatment as early as possible in the latent phase is likely to have the greatest potential to prevent injury ("neuroprotection"). In the secondary phase of injury, anticonvulsants can attenuate seizures, but show limited neuroprotection. Encouragingly, there is now increasing preclinical evidence that late, neurorestorative interventions have potential to improve long-term outcomes.
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Affiliation(s)
- Joanne O Davidson
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand.
| | - Fernando Gonzalez
- Department of Pediatrics, University of California, San Francisco, CA, USA.
| | | | - Alistair J Gunn
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand.
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Htun Y, Nakamura S, Kusaka T. Hydrogen and therapeutic gases for neonatal hypoxic-ischemic encephalopathy: potential neuroprotective adjuncts in translational research. Pediatr Res 2021; 89:753-759. [PMID: 32505123 DOI: 10.1038/s41390-020-0998-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/08/2020] [Accepted: 05/12/2020] [Indexed: 11/09/2022]
Abstract
Numerous studies have examined the potential use of therapeutic gases for the treatment of various neurological disorders. Hydrogen gas, a promising neuroprotective agent, has been a focus of study due to its potent antioxidative properties. In translational research into adult diseases, hydrogen has been shown to be neuroprotective in disorders such as cerebral ischemia and traumatic brain injury, and in neurodegenerative diseases such as Alzheimer's disease. Animal and human studies have verified the safety and feasibility of molecular hydrogen. However, despite extensive research on its efficacy in adults, only a few studies have investigated its application in pediatric and neonatal medicine. Neonatal hypoxic-ischemic encephalopathy (HIE) is characterized by damage to neurons and other cells of the nervous system. One of the major contributing factors is excessive exposure to oxidative stress. Current research interest in HIE is shifting toward new neuroprotective agents, as single agents or as adjuncts to therapeutic hypothermia. Here, we review therapeutic gases, particularly hydrogen, and their potentials and limitations in the treatment of HIE in newborns. IMPACT: Translational animal models of neonatal HIE are a current focus of research into the therapeutic usefulness of various gases. Hydrogen ventilation as a single agent or in combination with therapeutic hypothermia shows short- and long-term neuroprotection in neonatal translational HIE models. The optimal target severity for therapeutic interventions should be well established to improve outcomes.
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Affiliation(s)
- Yinmon Htun
- Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan.,Graduate School of Medicine, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Shinji Nakamura
- Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Takashi Kusaka
- Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan.
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Dingley J, Okano S, Lee-Kelland R, Scull-Brown E, Thoresen M, Chakkarapani E. Closed circuit xenon delivery for 72h in neonatal piglets following hypoxic insult using an ambient pressure automated control system: Development, technical evaluation and pulmonary effects. PLoS One 2020; 15:e0224447. [PMID: 31961878 PMCID: PMC6974042 DOI: 10.1371/journal.pone.0224447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 10/14/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Therapeutic hypothermia (TH) for 72h is the standard treatment following neonatal encephalopathy (NE). However, one-third do not benefit and adjunctive therapies are urgently needed. Xenon enhances neuroprotection with TH when administered at 50% concentration within 5hours of hypoxia in experimental studies. Delayed initiation (~10 hours of age) of 30% xenon for 24 hours during TH did not improve early adverse biomarkers in a clinical trial of Xenon+TH vs TH. After hypoxia-ischemia, excitotoxic injury via N-methyl-D-aspartate receptor overactivation lasts days. Since xenon partially inhibits this receptor, we hypothesised that giving 50% xenon throughout the entire 72h TH and rewarming periods would enhance neuroprotection. Xenon costs $30/litre, so a closed-circuit breathing system is desirable with automated fresh gas delivery. METHODS Seven mechanically ventilated newborn pigs were randomized to receive 50% inhaled xenon for 72h during hypothermia (rectal-temperature 35°C) and subsequent rewarming following a global hypoxic-ischemic insult (XeHT, N = 4) or under normothermia for 72h (rectal-temperature 38.5°C) following sham insult (XeNT, N = 3). An automated fresh gas delivery system injected oxygen/air/xenon boluses into a closed-circuit based on measured gas concentrations. RESULTS AND DISCUSSION Median (IQR) xenon consumption was 0.31 L/h (0.18, 0.50) and 0.34L/h (0.32, 0.49) for hypothermic and normothermic groups respectively, 0.34L/h (0.25, 0.53) overall. 92% of 9626 xenon and 69% of 9635 oxygen measurements were within 20% variation from targets. For xenon concentration, the median absolute performance errors for the XeHT and XeNT groups were 6.14% and 3.84% respectively and 4.31% overall. For oxygen these values were 13.42%, 15.05% and 12.4% respectively. There were no adverse pulmonary pathophysiology findings. Clinical problems over the total period included three related to sensors, seven breathing system leaks, ten partial and one complete tracheal tube occlusion episodes. CONCLUSION The automated controller functioned as intended maintaining an inhaled xenon concentration close to the 50% target for 72-78h at a xenon cost of $11.1/h.
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Affiliation(s)
- John Dingley
- Department of Anaesthetics ABM University Health Board, Swansea and College of Medicine, Swansea University, Swansea, Wales, United Kingdom
- * E-mail: ,
| | - Satomi Okano
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, England, United Kingdom
| | - Richard Lee-Kelland
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, England, United Kingdom
| | - Emma Scull-Brown
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, England, United Kingdom
| | - Marianne Thoresen
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, England, United Kingdom
- Department of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Ela Chakkarapani
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, England, United Kingdom
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Azzopardi D, Chew AT, Deierl A, Huertas A, Robertson NJ, Tusor N, Edwards AD. Prospective qualification of early cerebral biomarkers in a randomised trial of treatment with xenon combined with moderate hypothermia after birth asphyxia. EBioMedicine 2019; 47:484-491. [PMID: 31451436 PMCID: PMC6796501 DOI: 10.1016/j.ebiom.2019.08.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 08/16/2019] [Accepted: 08/16/2019] [Indexed: 11/28/2022] Open
Abstract
Background The TOBY-Xe proof of concept randomised trial found no effect of xenon combined with hypothermia after birth asphyxia on the lactate to N-acetyl aspartate ratio (Lac/NAA) in the thalamus and fractional anisotropy (FA) in white matter tracts measured within 15 days of birth. To confirm that these biomarkers are qualified to predict long-term outcome after neural rescue therapy we assessed surviving participants at 2–3 years of age. Methods Of the 92 infants in TOBY-Xe, one was omitted from the study, 69 survived and we assessed 62 participants, 32 in the hypothermia and xenon and 30 in the hypothermia only groups. We examined the relation between Lac/NAA and FA and the scores of the Bayley Scales of Infant and Toddler Development III and calculated their predictive accuracy for moderate or severe disability or death. Results Fifteen of 62 participants (24%) developed moderate/severe disability, and 22/92 (24%) died. The Lac/NAA ratio (difference in medians 0.628, 95% CI -0.392 to 4.684) and FA (difference in means −0.055, 95% CI -0.033 to −0.077) differed significantly between participants with or without moderate or severe disability or death and were significantly related with development scores in both groups. Adverse outcomes were correctly identified in 95.65% of cases by Lac/NAA and 78.79% by FA, with adequate mean calibration of the model. Interpretation The results confirm the qualification of the cerebral magnetic resonance biomarkers employed in the TOBY-Xe study as predictors of outcome after neuroprotective therapy. Fund The Centre for the Developing Brain, King's College London, UK.
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Affiliation(s)
- Denis Azzopardi
- Centre for the Developing Brain, School of Bioengineering and Imaging Sciences, King's College London, UK.
| | - Andrew T Chew
- Centre for the Developing Brain, School of Bioengineering and Imaging Sciences, King's College London, UK
| | - Aniko Deierl
- Neonatal Department, Imperial College Healthcare NHS Trust, London, UK
| | - Angela Huertas
- Neonatal Department, University College London Hospitals NHS Foundation Trust, London, UK
| | | | - Nora Tusor
- Centre for the Developing Brain, School of Bioengineering and Imaging Sciences, King's College London, UK
| | - A David Edwards
- Centre for the Developing Brain, School of Bioengineering and Imaging Sciences, King's College London, UK
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6
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Li H, Tan X, Xue Q, Zhu JH, Chen G. Combined application of hypothermia and medical gases in cerebrovascular diseases. Med Gas Res 2019; 8:172-175. [PMID: 30713671 PMCID: PMC6352567 DOI: 10.4103/2045-9912.248269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/06/2018] [Indexed: 01/11/2023] Open
Abstract
Cerebrovascular diseases have a heavy burden on society and the family. At present, in the treatment of cerebrovascular diseases, the recognized effective treatment method is a thrombolytic therapy after cerebral infarction, but limited to the time window problem, many patients cannot benefit. Other treatments for cerebrovascular disease are still in the exploration stage. The study found that medical gas and hypothermia have brain protection effects. Further research found that when the two are used in combination, the therapeutic effect has a superimposed effect. This article reviews the current research progress of hypothermia therapy combined with medical gas therapy for cerebrovascular disease.
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Affiliation(s)
- Hao Li
- Department of Neurology, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Xin Tan
- Department of Neurology, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Qun Xue
- Department of Neurology, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Jue-Hua Zhu
- Department of Neurology, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Gang Chen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, the First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
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Amer AR, Oorschot DE. Xenon Combined With Hypothermia in Perinatal Hypoxic-Ischemic Encephalopathy: A Noble Gas, a Noble Mission. Pediatr Neurol 2018; 84:5-10. [PMID: 29887039 DOI: 10.1016/j.pediatrneurol.2018.02.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Accepted: 02/21/2018] [Indexed: 12/14/2022]
Abstract
Perinatal hypoxia-ischemia is a major cause of neonatal morbidity. It generates primary neuronal damage of the neonatal brain and later secondary damage when reperfusion of the ischemic brain tissue causes a surge of oxygen free radicals and inflammation. This post-hypoxic-ischemic brain damage is a leading cause of motor and intellectual disabilities in survivors. Research worldwide has focused on mitigating this injury. Mild or moderate hypothermia is the standard treatment in many centers. However, its benefit is modest and the search for combinatorial effective neuroprotectants continues. This review focuses on xenon as one such agent. The use of mild to moderate hypothermia is reviewed first. Then promising results on the use of xenon to potentiate the effect of hypothermia in in vitro and in vivo animal experiments are discussed. In the first feasibility study on human neonates, researchers found a significant benefit of using 50% xenon for 18 hours in addition to 72 hours of hypothermia. Yet, this additional benefit of xenon was lacking in a larger cohort study, potentially because xenon was used beyond six hours of birth. The future of using xenon is promising, but further clinical studies are awaited to confirm the feasibility of its routine use and its optimal timing, concentration, and duration, for human neonatal hypoxia-ischemia.
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Affiliation(s)
- Ashraf R Amer
- Department of Anatomy, School of Biomedical Sciences and the Brain Health Research Center, University of Otago, Dunedin, New Zealand
| | - Dorothy E Oorschot
- Department of Anatomy, School of Biomedical Sciences and the Brain Health Research Center, University of Otago, Dunedin, New Zealand.
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8
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Zhang Z, Zhang L, Ding Y, Han Z, Ji X. Effects of Therapeutic Hypothermia Combined with Other Neuroprotective Strategies on Ischemic Stroke: Review of Evidence. Aging Dis 2018; 9:507-522. [PMID: 29896438 PMCID: PMC5988605 DOI: 10.14336/ad.2017.0628] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Accepted: 06/28/2017] [Indexed: 12/19/2022] Open
Abstract
Ischemic stroke is a major cause of death and disability globally, and its incidence is increasing. The only treatment approved by the US Food and Drug Administration for acute ischemic stroke is thrombolytic treatment with recombinant tissue plasminogen activator. As an alternative, therapeutic hypothermia has shown excellent potential in preclinical and small clinical studies, but it has largely failed in large clinical studies. This has led clinicians to explore the combination of therapeutic hypothermia with other neuroprotective strategies. This review examines preclinical and clinical progress towards developing highly effective combination therapy involving hypothermia for stroke patients.
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Affiliation(s)
- Zheng Zhang
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- Department of Neurology, the First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Linlei Zhang
- Department of Neurology, the Second Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Yuchuan Ding
- Department of Neurological Surgery, Wayne State University School of Medicine, Detroit, MI, USA
| | - Zhao Han
- Department of Neurology, the Second Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xunming Ji
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
- China-America Institute of Neuroscience, Xuanwu Hospital, Capital Medical University, Beijing, China
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9
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Rectal temperature in the first five hours after hypoxia-ischemia critically affects neuropathological outcomes in neonatal rats. Pediatr Res 2018; 83:536-544. [PMID: 28288145 DOI: 10.1038/pr.2017.51] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 02/06/2017] [Indexed: 01/15/2023]
Abstract
BackgroundHyperthermia after hypoxia-ischemia (HI) in newborn infants is associated with worse neurological outcomes. Loss of thermoregulation may also be associated with greater injury.MethodsIn the postnatal-day 7 (P7) rat, the effect of 5 h of graded hyperthermia (38 °C or 39 °C) immediately after unilateral HI was compared with normothermia (NT, 37 °C) and therapeutic hypothermia (TH, 32 °C). Early (negative geotaxis) and late (staircase test) behavioral testing was performed, as well as neuropathology scoring in adulthood. Separately, P7 rats were exposed to HI, and individual nesting temperatures were monitored before analysis of neuropathology at P14.ResultsMortality increased as temperature was increased from 38 °C (0%) to 39 °C (50%) after HI. Hyperthermia also resulted in early behavioral deficits compared with NT. In adulthood, pathology scores in the thalamus, basal ganglia, cortex, and hippocampus increased as post-hypoxic temperature increased above NT. Significant global neuroprotection was seen in the TH group. However, no significant difference was seen between HI groups in the staircase test. One hour after HI, the core temperature of pups was inversely correlated with global pathology scores at P14.ConclusionEarly temperature is a significant determinant of injury after experimental HI. Spontaneous decreases in core temperature after HI may confound neuroprotection studies.
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Barks JD, Liu Y, Shangguan Y, Djuric Z, Ren J, Silverstein FS. Maternal high-fat diet influences outcomes after neonatal hypoxic-ischemic brain injury in rodents. J Cereb Blood Flow Metab 2017; 37:307-318. [PMID: 26738750 PMCID: PMC5363747 DOI: 10.1177/0271678x15624934] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 11/25/2015] [Accepted: 12/07/2015] [Indexed: 12/17/2022]
Abstract
The typical US diet has >30% calories from fat; yet, typical laboratory diets contain 17% calories from fat. This disparity could confound the clinical relevance of findings in cerebral ischemia models. We compared outcomes after neonatal brain injury in offspring of rat dams fed standard low-fat chow (17% fat calories) or a higher fat diet (34% fat calories) from day 7 of pregnancy. On postnatal day 7, hypoxic-ischemic injury was induced by right carotid ligation, followed by 60, 75 or 90 min 8% oxygen exposure. Sensorimotor function, brain damage, and serum and brain fatty acid content were compared 1 to 4 weeks later. All lesioned animals developed left forepaw placing deficits; scores were worse in the high-fat groups (p < 0.0001, ANOVA). Similarly, reductions in left forepaw grip strength were more pronounced in the high-fat groups. Severity of right hemisphere damage increased with hypoxia-ischemia duration but did not differ between diet groups. Serum and brain docosahexaenoic acid fatty acid fractions were lower in high-fat progeny (p < 0.05, ANOVA). We speculate that the high-fat diet disrupted docosahexaenoic acid-dependent recovery mechanisms. These findings have significant implications both for refinement of neonatal brain injury models and for understanding the impact of maternal diet on neonatal neuroplasticity.
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Affiliation(s)
- John D Barks
- Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA
| | - Yiqing Liu
- Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA
| | - Yu Shangguan
- Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA
| | - Zora Djuric
- Department of Family Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Jianwei Ren
- Department of Family Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Faye S Silverstein
- Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA.,Department of Neurology, University of Michigan, Ann Arbor, MI, USA
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Kochanek P, Kitagawa RS, Batchelor P, Thoresen M. Central Nervous System Injury and Temperature Management. Ther Hypothermia Temp Manag 2016; 6:112-5. [PMID: 27447753 DOI: 10.1089/ther.2016.29014.pjk] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Affiliation(s)
- Patrick Kochanek
- 1 Department of Critical Care Medicine, University of Pittsburgh Medical Center , Pittsburgh, Pennsylvania
| | - Ryan S Kitagawa
- 2 The Vivian L. Smith Department of Neurosurgery, University of Texas , Houston, Texas
| | - Peter Batchelor
- 3 Department of Medicine, University of Melbourne , Melbourne, Australia
| | - Marianne Thoresen
- 4 Department of Physiology, Institute of Basic Medical Sciences, University of Oslo , Oslo, Norway
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12
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Xenon Combined with Therapeutic Hypothermia Is Not Neuroprotective after Severe Hypoxia-Ischemia in Neonatal Rats. PLoS One 2016; 11:e0156759. [PMID: 27253085 PMCID: PMC4890818 DOI: 10.1371/journal.pone.0156759] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 05/19/2016] [Indexed: 11/21/2022] Open
Abstract
Background Therapeutic hypothermia (TH) is standard treatment following perinatal asphyxia in newborn infants. Experimentally, TH is neuroprotective after moderate hypoxia-ischemia (HI) in seven-day-old (P7) rats. However, TH is not neuroprotective after severe HI. After a moderate HI insult in newborn brain injury models, the anesthetic gas xenon (Xe) doubles TH neuroprotection. The aim of this study was to examine whether combining Xe and TH is neuroprotective as applied in a P7 rat model of severe HI. Design/Methods 120 P7 rat pups underwent a severe HI insult; unilateral carotid artery ligation followed by hypoxia (8% O2 for 150min at experimental normothermia (NT-37: Trectal 37°C). Surviving pups were randomised to immediate NT-37 for 5h (n = 36), immediate TH-32: Trectal 32°C for 5h (n = 25) or immediate TH-32 plus 50% inhaled Xe for 5h (n = 24). Pups were sacrificed after one week of survival. Relative area loss of the ligated hemisphere was measured, and neurons in the subventricular zone of this injured hemisphere were counted, to quantify brain damage. Results Following the HI insult, median (interquartile range, IQR) hemispheric brain area loss was similar in all groups: 63.5% (55.5–75.0) for NT-37 group, 65.0% (57.0–65.0) for TH-32 group, and 66.5% (59.0–72.0) for TH-32+Xe50% group (not significant). Correspondingly, there was no difference in neuronal cell count (NeuN marker) in the subventricular zone across the three treatment groups. Conclusions Immediate therapeutic hypothermia with or without additional 50% inhaled Xe, does not provide neuroprotection one week after severe HI brain injury in the P7 neonatal rat. This model aims to mimic the clinical situation in severely asphyxiated neonates and treatment these newborns remains an ongoing challenge.
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13
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Abstract
An adverse outcome is still encountered in 45% of full-term neonates with perinatal asphyxia who are treated with moderate hypothermia. At present pharmacologic therapies are developed to be added to hypothermia. In the present article, these potential neuroprotective interventions are described based on the molecular pathways set in motion during fetal hypoxia and following reoxygenation and reperfusion after birth. These pathways include excessive production of excitotoxins with subsequent over-stimulation of NMDA receptors and calcium influx in neuronal cells, excessive production of reactive oxygen and nitrogen species, activation of inflammation leading to inappropriate apoptosis, and loss of neurotrophic factors. Possibilities for pharmacologic combination therapy, where each drug will be administered based on the optimal point of time in the cascade of destructive molecular reactions, may further reduce brain damage due to perinatal asphyxia.
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Affiliation(s)
- Frank van Bel
- Department of Neonatology, University Medical Center Utrecht, Wilhelmina Children's Hospital, Utrecht, The Netherlands.
| | - Floris Groenendaal
- Department of Neonatology, University Medical Center Utrecht, Wilhelmina Children's Hospital, Utrecht, The Netherlands
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14
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Azzopardi D, Robertson NJ, Bainbridge A, Cady E, Charles-Edwards G, Deierl A, Fagiolo G, Franks NP, Griffiths J, Hajnal J, Juszczak E, Kapetanakis B, Linsell L, Maze M, Omar O, Strohm B, Tusor N, Edwards AD. Moderate hypothermia within 6 h of birth plus inhaled xenon versus moderate hypothermia alone after birth asphyxia (TOBY-Xe): a proof-of-concept, open-label, randomised controlled trial. Lancet Neurol 2015; 15:145-153. [PMID: 26708675 PMCID: PMC4710577 DOI: 10.1016/s1474-4422(15)00347-6] [Citation(s) in RCA: 141] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 11/03/2015] [Accepted: 11/16/2015] [Indexed: 11/15/2022]
Abstract
Background Moderate cooling after birth asphyxia is associated with substantial reductions in death and disability, but additional therapies might provide further benefit. We assessed whether the addition of xenon gas, a promising novel therapy, after the initiation of hypothermia for birth asphyxia would result in further improvement. Methods Total Body hypothermia plus Xenon (TOBY-Xe) was a proof-of-concept, randomised, open-label, parallel-group trial done at four intensive-care neonatal units in the UK. Eligible infants were 36–43 weeks of gestational age, had signs of moderate to severe encephalopathy and moderately or severely abnormal background activity for at least 30 min or seizures as shown by amplitude-integrated EEG (aEEG), and had one of the following: Apgar score of 5 or less 10 min after birth, continued need for resuscitation 10 min after birth, or acidosis within 1 h of birth. Participants were allocated in a 1:1 ratio by use of a secure web-based computer-generated randomisation sequence within 12 h of birth to cooling to a rectal temperature of 33·5°C for 72 h (standard treatment) or to cooling in combination with 30% inhaled xenon for 24 h started immediately after randomisation. The primary outcomes were reduction in lactate to N-acetyl aspartate ratio in the thalamus and in preserved fractional anisotropy in the posterior limb of the internal capsule, measured with magnetic resonance spectroscopy and MRI, respectively, within 15 days of birth. The investigator assessing these outcomes was masked to allocation. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00934700, and with ISRCTN, as ISRCTN08886155. Findings The study was done from Jan 31, 2012, to Sept 30, 2014. We enrolled 92 infants, 46 of whom were randomly assigned to cooling only and 46 to xenon plus cooling. 37 infants in the cooling only group and 41 in the cooling plus xenon group underwent magnetic resonance assessments and were included in the analysis of the primary outcomes. We noted no significant differences in lactate to N-acetyl aspartate ratio in the thalamus (geometric mean ratio 1·09, 95% CI 0·90 to 1·32) or fractional anisotropy (mean difference −0·01, 95% CI −0·03 to 0·02) in the posterior limb of the internal capsule between the two groups. Nine infants died in the cooling group and 11 in the xenon group. Two adverse events were reported in the xenon group: subcutaneous fat necrosis and transient desaturation during the MRI. No serious adverse events were recorded. Interpretation Administration of xenon within the delayed timeframe used in this trial is feasible and apparently safe, but is unlikely to enhance the neuroprotective effect of cooling after birth asphyxia. Funding UK Medical Research Council.
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Affiliation(s)
- Denis Azzopardi
- Centre for the Developing Brain, Division of Imaging Sciences and Bioengineering, King's College London, London, UK.
| | | | | | - Ernest Cady
- Faculty of Engineering Science, University College London, London, UK
| | | | - Aniko Deierl
- Division of Neonatology, Imperial College Healthcare NHS Trust, London, UK
| | - Gianlorenzo Fagiolo
- Centre for the Developing Brain, Division of Imaging Sciences and Bioengineering, King's College London, London, UK
| | - Nicholas P Franks
- Faculty of Natural Sciences, Department of Life Sciences, Imperial College London, London, UK
| | - James Griffiths
- National Perinatal Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Joseph Hajnal
- Centre for the Developing Brain, Division of Imaging Sciences and Bioengineering, King's College London, London, UK
| | - Edmund Juszczak
- National Perinatal Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Basil Kapetanakis
- Centre for the Developing Brain, Division of Imaging Sciences and Bioengineering, King's College London, London, UK
| | - Louise Linsell
- National Perinatal Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Mervyn Maze
- Anesthesia and Perioperative Care, University of California San Francisco School of Medicine, San Francisco, CA, USA
| | - Omar Omar
- National Perinatal Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Brenda Strohm
- National Perinatal Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Nora Tusor
- Centre for the Developing Brain, Division of Imaging Sciences and Bioengineering, King's College London, London, UK
| | - A David Edwards
- Centre for the Developing Brain, Division of Imaging Sciences and Bioengineering, King's College London, London, UK
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Non-additive effects of delayed connexin hemichannel blockade and hypothermia after cerebral ischemia in near-term fetal sheep. J Cereb Blood Flow Metab 2015; 35:2052-61. [PMID: 26174327 PMCID: PMC4671127 DOI: 10.1038/jcbfm.2015.171] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 06/07/2015] [Accepted: 06/09/2015] [Indexed: 12/31/2022]
Abstract
Hypothermia is partially neuroprotective after neonatal hypoxic-ischemic encephalopathy. Blockade of connexin hemichannels can improve recovery of brain activity and cell survival after ischemia in near-term fetal sheep. In this study, we investigated whether combining delayed hypothermia with connexin hemichannel blockade with intracerebroventricular infusion of a mimetic peptide can further improve outcomes after cerebral ischemia. Fetal sheep (0.85 gestation) received 30 minutes of cerebral ischemia followed by a 3-hour recovery period before treatment was started. Fetuses were randomized to one of the following treatment groups: normothermia (n=8), hypothermia for 3 days (n=8), connexin hemichannel blockade (50 μmol/L intracerebroventricular over 1 hour followed by 50 μmol/L over 24 hours, n=8) or hypothermia plus hemichannel blockade (n=7). After 7 days recovery, hypothermia was associated with reduced seizure burden, improved electroencephalographic (EEG) power, and a significant increase in neuronal and oligodendrocyte survival and reduced induction of Iba1-positive microglia. In contrast, although hemichannel blockade reduced seizure burden, there was no effect on EEG power or histology (P<0.05). There was no further improvement in outcomes with combined hypothermia plus hemichannel blockade. In conclusion, these data show that there is no additive neuroprotection with combined hypothermia and hemichannel blockade after cerebral ischemia in near-term fetal sheep.
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16
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Smit E, Liu X, Gill H, Jary S, Wood T, Thoresen M. The effect of resuscitation in 100% oxygen on brain injury in a newborn rat model of severe hypoxic-ischaemic encephalopathy. Resuscitation 2015; 96:214-9. [PMID: 26300234 DOI: 10.1016/j.resuscitation.2015.07.050] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 07/24/2015] [Accepted: 07/30/2015] [Indexed: 10/23/2022]
Abstract
AIM Infants with birth asphyxia frequently require resuscitation. Current guidance is to start newborn resuscitation in 21% oxygen. However, infants with severe hypoxia-ischaemia may require prolonged resuscitation with oxygen. To date, no study has looked at the effect of resuscitation in 100% oxygen following a severe hypoxic-ischaemic insult. METHODS Postnatal day 7 Wistar rats underwent a severe hypoxic-ischaemic insult (modified Vannucci unilateral brain injury model) followed by immediate resuscitation in either 21% or 100% oxygen for 30 min. Seven days following the insult, negative geotaxis testing was performed in survivors, and the brains were harvested. Relative ipsilateral cortical and hippocampal area loss was assessed histologically. RESULTS Total area loss in the affected hemisphere and area loss within the hippocampus did not significantly differ between the two groups. The same results were seen for short-term neurological assessment. No difference was seen in weight gain between pups resuscitated in 21% and 100% oxygen. CONCLUSION Resuscitation in 100% oxygen does not cause a deleterious effect on brain injury following a severe hypoxic-ischaemic insult in a rat model of hypoxia-ischaemia. Further work investigating the effects of resuscitation in 100% oxygen is warranted, especially for newborn infants with severe hypoxic-ischaemic encephalopathy.
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Affiliation(s)
- Elisa Smit
- Neonatal Neuroscience, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Xun Liu
- Neonatal Neuroscience, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Hannah Gill
- Neonatal Neuroscience, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Sally Jary
- Neonatal Neuroscience, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Thomas Wood
- Division of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Marianne Thoresen
- Neonatal Neuroscience, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom; Division of Physiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
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