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Molloy EJ, El-Dib M, Soul J, Juul S, Gunn AJ, Bender M, Gonzalez F, Bearer C, Wu Y, Robertson NJ, Cotton M, Branagan A, Hurley T, Tan S, Laptook A, Austin T, Mohammad K, Rogers E, Luyt K, Wintermark P, Bonifacio SL. Neuroprotective therapies in the NICU in preterm infants: present and future (Neonatal Neurocritical Care Series). Pediatr Res 2024; 95:1224-1236. [PMID: 38114609 PMCID: PMC11035150 DOI: 10.1038/s41390-023-02895-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 10/19/2023] [Accepted: 10/26/2023] [Indexed: 12/21/2023]
Abstract
The survival of preterm infants has steadily improved thanks to advances in perinatal and neonatal intensive clinical care. The focus is now on finding ways to improve morbidities, especially neurological outcomes. Although antenatal steroids and magnesium for preterm infants have become routine therapies, studies have mainly demonstrated short-term benefits for antenatal steroid therapy but limited evidence for impact on long-term neurodevelopmental outcomes. Further advances in neuroprotective and neurorestorative therapies, improved neuromonitoring modalities to optimize recruitment in trials, and improved biomarkers to assess the response to treatment are essential. Among the most promising agents, multipotential stem cells, immunomodulation, and anti-inflammatory therapies can improve neural outcomes in preclinical studies and are the subject of considerable ongoing research. In the meantime, bundles of care protecting and nurturing the brain in the neonatal intensive care unit and beyond should be widely implemented in an effort to limit injury and promote neuroplasticity. IMPACT: With improved survival of preterm infants due to improved antenatal and neonatal care, our focus must now be to improve long-term neurological and neurodevelopmental outcomes. This review details the multifactorial pathogenesis of preterm brain injury and neuroprotective strategies in use at present, including antenatal care, seizure management and non-pharmacological NICU care. We discuss treatment strategies that are being evaluated as potential interventions to improve the neurodevelopmental outcomes of infants born prematurely.
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Affiliation(s)
- Eleanor J Molloy
- Paediatrics, Trinity College Dublin, Trinity Research in Childhood Centre (TRICC), Dublin, Ireland.
- Children's Hospital Ireland (CHI) at Tallaght, Dublin, Ireland.
- Neonatology, CHI at Crumlin, Dublin, Ireland.
- Neonatology, Coombe Women's and Infants University Hospital, Dublin, Ireland.
| | - Mohamed El-Dib
- Department of Pediatrics, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Janet Soul
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Sandra Juul
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Alistair J Gunn
- Departments of Physiology and Paediatrics, School of Medical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Manon Bender
- Department of Neonatology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Fernando Gonzalez
- Department of Neurology, Division of Child Neurology, University of California, San Francisco, California, USA
| | - Cynthia Bearer
- Division of Neonatology, Department of Pediatrics, Rainbow Babies & Children's Hospital, Cleveland, Ohio, USA
- Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Yvonne Wu
- Department of Neurology, University of California San Francisco, San Francisco, California, USA
| | - Nicola J Robertson
- Institute for Women's Health, University College London, London, UK
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Mike Cotton
- Department of Pediatrics, Duke University, Durham, North Carolina, USA
| | - Aoife Branagan
- Paediatrics, Trinity College Dublin, Trinity Research in Childhood Centre (TRICC), Dublin, Ireland
- Neonatology, Coombe Women's and Infants University Hospital, Dublin, Ireland
| | - Tim Hurley
- Paediatrics, Trinity College Dublin, Trinity Research in Childhood Centre (TRICC), Dublin, Ireland
| | - Sidhartha Tan
- Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Abbot Laptook
- Department of Pediatrics, Women and Infants Hospital, Brown University, Providence, Rhode Island, USA
| | - Topun Austin
- Department of Paediatrics, University of Cambridge, Cambridge, UK
| | - Khorshid Mohammad
- Section of Neonatology, Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada
| | - Elizabeth Rogers
- Department of Pediatrics, University of California, San Francisco Benioff Children's Hospital, San Francisco, California, USA
| | - Karen Luyt
- Translational Health Sciences, University of Bristol, Bristol, UK
- Neonatology, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK
| | - Pia Wintermark
- Division of Neonatology, Montreal Children's Hospital, Montreal, Quebec, Canada
- McGill University Health Centre - Research Institute, Montreal, Quebec, Canada
| | - Sonia Lomeli Bonifacio
- Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA
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Bolini L, Campos RMP, Spiess DA, Lima-Rosa FL, Dantas DP, Conde L, Mendez-Otero R, Vale AM, Pimentel-Coelho PM. Long-term recruitment of peripheral immune cells to brain scars after a neonatal insult. Glia 2024; 72:546-567. [PMID: 37987116 DOI: 10.1002/glia.24490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 10/23/2023] [Accepted: 10/31/2023] [Indexed: 11/22/2023]
Abstract
Although brain scars in adults have been extensively studied, there is less data available regarding scar formation during the neonatal period, and the involvement of peripheral immune cells in this process remains unexplored in neonates. Using a murine model of neonatal hypoxic-ischemic encephalopathy (HIE) and confocal microscopy, we characterized the scarring process and examined the recruitment of peripheral immune cells to cortical and hippocampal scars for up to 1 year post-insult. Regional differences in scar formation were observed, including the presence of reticular fibrotic networks in the cortex and perivascular fibrosis in the hippocampus. We identified chemokines with chronically elevated levels in both regions and demonstrated, through a parabiosis-based strategy, the recruitment of lymphocytes, neutrophils, and monocyte-derived macrophages to the scars several weeks after the neonatal insult. After 1 year, however, neutrophils and lymphocytes were absent from the scars. Our data indicate that peripheral immune cells are transient components of HIE-induced brain scars, opening up new possibilities for late therapeutic interventions.
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Affiliation(s)
- Lukas Bolini
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Daiane Aparecida Spiess
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Frederico Luis Lima-Rosa
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Danillo Pereira Dantas
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luciana Conde
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rosalia Mendez-Otero
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Andre M Vale
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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Lear CA, Lear BA, Davidson JO, King VJ, Maeda Y, McDouall A, Dhillon SK, Gunn AJ, Bennet L. Dysmaturation of sleep state and electroencephalographic activity after hypoxia-ischaemia in preterm fetal sheep. J Cereb Blood Flow Metab 2024:271678X241236014. [PMID: 38415649 DOI: 10.1177/0271678x241236014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
Antenatal hypoxia-ischaemia (HI) in preterm fetal sheep can trigger delayed evolution of severe, cystic white matter injury (WMI), in a similar timecourse to WMI in preterm infants. We therefore examined how severe hypoxia-ischaemia affects recovery of electroencephalographic (EEG) activity. Chronically instrumented preterm fetal sheep (0.7 gestation) received 25 min of complete umbilical cord occlusion (UCO, n = 9) or sham occlusion (controls, n = 9), and recovered for 21 days. HI was associated with a shift to lower frequency EEG activity for the first 5 days with persisting loss of EEG power in the delta and theta bands, and initial loss of power in the alpha and beta bands in the first 14 days of recovery. In the final 3 days of recovery, there was a marked rhythmic shift towards higher frequency EEG activity after UCO. The UCO group spent less time in high-voltage sleep, and in the early evening (7:02 pm ± 47 min) abruptly stopped cycling between sleep states, with a shift to a high frequency state for 2 h 48 min ± 40 min, with tonic electromyographic activity. These findings demonstrate persisting EEG and sleep state dysmaturation after severe hypoxia-ischaemia. Loss of fetal or neonatal sleep state cycling in the early evening may be a useful biomarker for evolving cystic WMI.
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Affiliation(s)
- Christopher A Lear
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Benjamin A Lear
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Joanne O Davidson
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Victoria J King
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Yoshiki Maeda
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Alice McDouall
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Simerdeep K Dhillon
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
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4
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Kelly SB, Tran NT, Polglase GR, Hunt RW, Nold MF, Nold-Petry CA, Olson DM, Chemtob S, Lodygensky GA, Robertson SA, Gunn AJ, Galinsky R. A systematic review of immune-based interventions for perinatal neuroprotection: closing the gap between animal studies and human trials. J Neuroinflammation 2023; 20:241. [PMID: 37864272 PMCID: PMC10588248 DOI: 10.1186/s12974-023-02911-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 09/28/2023] [Indexed: 10/22/2023] Open
Abstract
BACKGROUND Perinatal infection/inflammation is associated with a high risk for neurological injury and neurodevelopmental impairment after birth. Despite a growing preclinical evidence base, anti-inflammatory interventions have not been established in clinical practice, partly because of the range of potential targets. We therefore systematically reviewed preclinical studies of immunomodulation to improve neurological outcomes in the perinatal brain and assessed their therapeutic potential. METHODS We reviewed relevant studies published from January 2012 to July 2023 using PubMed, Medline (OvidSP) and EMBASE databases. Studies were assessed for risk of bias using the SYRCLE risk of bias assessment tool (PROSPERO; registration number CRD42023395690). RESULTS Forty preclinical publications using 12 models of perinatal neuroinflammation were identified and divided into 59 individual studies. Twenty-seven anti-inflammatory agents in 19 categories were investigated. Forty-five (76%) of 59 studies reported neuroprotection, from all 19 categories of therapeutics. Notably, 10/10 (100%) studies investigating anti-interleukin (IL)-1 therapies reported improved outcome, whereas half of the studies using corticosteroids (5/10; 50%) reported no improvement or worse outcomes with treatment. Most studies (49/59, 83%) did not control core body temperature (a known potential confounder), and 25 of 59 studies (42%) did not report the sex of subjects. Many studies did not clearly state whether they controlled for potential study bias. CONCLUSION Anti-inflammatory therapies are promising candidates for treatment or even prevention of perinatal brain injury. Our analysis highlights key knowledge gaps and opportunities to improve preclinical study design that must be addressed to support clinical translation.
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Affiliation(s)
- Sharmony B Kelly
- The Ritchie Centre, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, Melbourne, VIC, 3168, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| | - Nhi T Tran
- The Ritchie Centre, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, Melbourne, VIC, 3168, Australia
| | - Graeme R Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, Melbourne, VIC, 3168, Australia
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| | - Rodney W Hunt
- The Ritchie Centre, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, Melbourne, VIC, 3168, Australia
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
- Monash Newborn, Monash Children's Hospital, Melbourne, Australia
| | - Marcel F Nold
- The Ritchie Centre, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, Melbourne, VIC, 3168, Australia
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
- Monash Newborn, Monash Children's Hospital, Melbourne, Australia
| | - Claudia A Nold-Petry
- The Ritchie Centre, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, Melbourne, VIC, 3168, Australia
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - David M Olson
- Department of Obstetrics and Gynaecology, University of Alberta, Edmonton, Canada
| | - Sylvain Chemtob
- Department of Paediatrics, CHU Sainte Justine Research Centre, University of Montreal, Quebec, Canada
| | - Gregory A Lodygensky
- Department of Paediatrics, CHU Sainte Justine Research Centre, University of Montreal, Quebec, Canada
| | - Sarah A Robertson
- The University of Adelaide, Robinson Research Institute, North Adelaide, SA, Australia
| | - Alistair J Gunn
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Robert Galinsky
- The Ritchie Centre, Hudson Institute of Medical Research, 27-31 Wright Street, Clayton, Melbourne, VIC, 3168, Australia.
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia.
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Lear CA, Ugwumadu A, Bennet L, Gunn AJ. An Update of Our Understanding of Fetal Heart Rate Patterns in Health and Disease. Semin Pediatr Neurol 2023; 47:101072. [PMID: 37919038 DOI: 10.1016/j.spen.2023.101072] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 08/03/2023] [Indexed: 11/04/2023]
Abstract
UNDERSTANDING FETAL HEART RATE PATTERNS THAT MAY PREDICT ANTENATAL AND INTRAPARTUM NEURAL INJURY: Christopher A. Lear, Jenny A. Westgate, Austin Ugwumadu, Jan G. Nijhuis, Peter R. Stone, Antoniya Georgieva, Tomoaki Ikeda, Guido Wassink , Laura Bennet , Alistair J. Gunn Seminars in Pediatric Neurology Volume 28, December 2018, Pages 3-16 Electronic fetal heart rate (FHR) monitoring is widely used to assess fetal well-being throughout pregnancy and labor. Both antenatal and intrapartum FHR monitoring are associated with a high negative predictive value and a very poor positive predictive value. This in part reflects the physiological resilience of the healthy fetus and the remarkable effectiveness of fetal adaptations to even severe challenges. In this way, the majority of "abnormal" FHR patterns in fact reflect a fetus' appropriate adaptive responses to adverse in utero conditions. Understanding the physiology of these adaptations, how they are reflected in the FHR trace and in what conditions they can fail is therefore critical to appreciating both the potential uses and limitations of electronic FHR monitoring.
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Affiliation(s)
- Christopher A Lear
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Austin Ugwumadu
- Department of Obstetrics and Gynaecology, St George's Hospital, St George's University of London, London, UK
| | - Laura Bennet
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand.
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Häusler S, Robertson NJ, Golhen K, van den Anker J, Tucker K, Felder TK. Melatonin as a Therapy for Preterm Brain Injury: What Is the Evidence? Antioxidants (Basel) 2023; 12:1630. [PMID: 37627625 PMCID: PMC10451719 DOI: 10.3390/antiox12081630] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 07/28/2023] [Accepted: 08/15/2023] [Indexed: 08/27/2023] Open
Abstract
Despite significant improvements in survival following preterm birth in recent years, the neurodevelopmental burden of prematurity, with its long-term cognitive and behavioral consequences, remains a significant challenge in neonatology. Neuroprotective treatment options to improve neurodevelopmental outcomes in preterm infants are therefore urgently needed. Alleviating inflammatory and oxidative stress (OS), melatonin might modify important triggers of preterm brain injury, a complex combination of destructive and developmental abnormalities termed encephalopathy of prematurity (EoP). Preliminary data also suggests that melatonin has a direct neurotrophic impact, emphasizing its therapeutic potential with a favorable safety profile in the preterm setting. The current review outlines the most important pathomechanisms underlying preterm brain injury and correlates them with melatonin's neuroprotective potential, while underlining significant pharmacokinetic/pharmacodynamic uncertainties that need to be addressed in future studies.
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Affiliation(s)
- Silke Häusler
- Division of Neonatology, Department of Pediatrics, Paracelsus Medical University Salzburg, 5020 Salzburg, Austria
| | - Nicola J. Robertson
- EGA Institute for Women’s Health, University College London, London WC1E 6HX, UK; (N.J.R.); (K.T.)
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK
| | - Klervi Golhen
- Pediatric Pharmacology and Pharmacometrics, University Children’s Hospital Basel (UKBB), University of Basel, 4001 Basel, Switzerland; (K.G.); (J.v.d.A.)
| | - John van den Anker
- Pediatric Pharmacology and Pharmacometrics, University Children’s Hospital Basel (UKBB), University of Basel, 4001 Basel, Switzerland; (K.G.); (J.v.d.A.)
- Division of Clinical Pharmacology, Children’s National Hospital, Washington, DC 20001, USA
| | - Katie Tucker
- EGA Institute for Women’s Health, University College London, London WC1E 6HX, UK; (N.J.R.); (K.T.)
| | - Thomas K. Felder
- Department of Laboratory Medicine, Paracelsus Medical University, 5020 Salzburg, Austria;
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Lear CA, Maeda Y, King VJ, Dhillon SK, Beacom MJ, Gunning MI, Lear BA, Davidson JO, Stone PR, Ikeda T, Gunn AJ, Bennet L. Circadian patterns of heart rate variability in fetal sheep after hypoxia-ischaemia: A biomarker of evolving brain injury. J Physiol 2023. [PMID: 37432936 DOI: 10.1113/jp284560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 06/23/2023] [Indexed: 07/13/2023] Open
Abstract
Hypoxia-ischaemia (HI) before birth is a key risk factor for stillbirth and severe neurodevelopmental disability in survivors, including cerebral palsy, although there are no reliable biomarkers to detect at risk fetuses that may have suffered a transient period of severe HI. We investigated time and frequency domain measures of fetal heart rate variability (FHRV) for 3 weeks after HI in preterm fetal sheep at 0.7 gestation (equivalent to preterm humans) until 0.8 gestation (equivalent to term humans). We have previously shown that this is associated with delayed development of severe white and grey matter injury, including cystic white matter injury (WMI) resembling that observed in human preterm infants. HI was associated with suppression of time and frequency domain measures of FHRV and reduced their circadian rhythmicity during the first 3 days of recovery. By contrast, circadian rhythms of multiple measures of FHRV were exaggerated over the final 2 weeks of recovery, mediated by a greater reduction in FHRV during the morning nadir, but no change in the evening peak. These data suggest that the time of day at which FHRV measurements are taken affects their diagnostic utility. We further propose that circadian changes in FHRV may be a low-cost, easily applied biomarker of antenatal HI and evolving brain injury. KEY POINTS: Hypoxia-ischaemia (HI) before birth is a key risk factor for stillbirth and probably for disability in survivors, although there are no reliable biomarkers for antenatal brain injury. In preterm fetal sheep, acute HI that is known to lead to delayed development of severe white and grey matter injury over 3 weeks, was associated with early suppression of multiple time and frequency domain measures of fetal heart rate variability (FHRV) and loss of their circadian rhythms during the first 3 days after HI. Over the final 2 weeks of recovery after HI, exaggerated circadian rhythms of frequency domain FHRV measures were observed. The morning nadirs were lower with no change in the evening peak of FHRV. Circadian changes in FHRV may be a low-cost, easily applied biomarker of antenatal HI and evolving brain injury.
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Affiliation(s)
- Christopher A Lear
- Department of Physiology, Fetal Physiology and Neuroscience Group, The University of Auckland, Auckland, New Zealand
| | - Yoshiki Maeda
- Department of Physiology, Fetal Physiology and Neuroscience Group, The University of Auckland, Auckland, New Zealand
- The Department of Obstetrics and Gynaecology, Mie University, Mie, Japan
| | - Victoria J King
- Department of Physiology, Fetal Physiology and Neuroscience Group, The University of Auckland, Auckland, New Zealand
| | - Simerdeep K Dhillon
- Department of Physiology, Fetal Physiology and Neuroscience Group, The University of Auckland, Auckland, New Zealand
| | - Michael J Beacom
- Department of Physiology, Fetal Physiology and Neuroscience Group, The University of Auckland, Auckland, New Zealand
| | - Mark I Gunning
- Department of Physiology, Fetal Physiology and Neuroscience Group, The University of Auckland, Auckland, New Zealand
| | - Benjamin A Lear
- Department of Physiology, Fetal Physiology and Neuroscience Group, The University of Auckland, Auckland, New Zealand
| | - Joanne O Davidson
- Department of Physiology, Fetal Physiology and Neuroscience Group, The University of Auckland, Auckland, New Zealand
| | - Peter R Stone
- The Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, New Zealand
| | - Tomoaki Ikeda
- The Department of Obstetrics and Gynaecology, Mie University, Mie, Japan
| | - Alistair J Gunn
- Department of Physiology, Fetal Physiology and Neuroscience Group, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- Department of Physiology, Fetal Physiology and Neuroscience Group, The University of Auckland, Auckland, New Zealand
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Galinsky R, Dhillon SK, Kelly SB, Wassink G, Davidson JO, Lear CA, van den Heuij LG, Bennet L, Gunn AJ. Magnesium sulphate reduces tertiary gliosis but does not improve EEG recovery or white or grey matter cell survival after asphyxia in preterm fetal sheep. J Physiol 2023; 601:1999-2016. [PMID: 36999348 PMCID: PMC10952359 DOI: 10.1113/jp284381] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 03/09/2023] [Indexed: 04/01/2023] Open
Abstract
Maternal magnesium sulphate (MgSO4 ) treatment is widely recommended before preterm birth for neuroprotection. However, this is controversial because there is limited evidence that MgSO4 provides long-term neuroprotection. Preterm fetal sheep (104 days gestation; term is 147 days) were assigned randomly to receive sham occlusion with saline infusion (n = 6) or i.v. infusion with MgSO4 (n = 7) or vehicle (saline, n = 6) from 24 h before hypoxia-ischaemia induced by umbilical cord occlusion until 24 h after occlusion. Sheep were killed after 21 days of recovery, for fetal brain histology. Functionally, MgSO4 did not improve long-term EEG recovery. Histologically, in the premotor cortex and striatum, MgSO4 infusion attenuated post-occlusion astrocytosis (GFAP+ ) and microgliosis but did not affect numbers of amoeboid microglia or improve neuronal survival. In the periventricular and intragyral white matter, MgSO4 was associated with fewer total (Olig-2+ ) oligodendrocytes compared with vehicle + occlusion. Numbers of mature (CC1+ ) oligodendrocytes were reduced to a similar extent in both occlusion groups compared with sham occlusion. In contrast, MgSO4 was associated with an intermediate improvement in myelin density in the intragyral and periventricular white matter tracts. In conclusion, a clinically comparable dose of MgSO4 was associated with moderate improvements in white and grey matter gliosis and myelin density but did not improve EEG maturation or neuronal or oligodendrocyte survival. KEY POINTS: Magnesium sulphate is widely recommended before preterm birth for neuroprotection; however, there is limited evidence that magnesium sulphate provides long-term neuroprotection. In preterm fetal sheep exposed to hypoxia-ischaemia (HI), MgSO4 was associated with attenuated astrocytosis and microgliosis in the premotor cortex and striatum but did not improve neuronal survival after recovery to term-equivalent age, 21 days after HI. Magnesium sulphate was associated with loss of total oligodendrocytes in the periventricular and intragyral white matter tracts, whereas mature, myelinating oligodendrocytes were reduced to a similar extent in both occlusion groups. In the same regions, MgSO4 was associated with an intermediate improvement in myelin density. Functionally, MgSO4 did not improve long-term recovery of EEG power, frequency or sleep stage cycling. A clinically comparable dose of MgSO4 was associated with moderate improvements in white and grey matter gliosis and myelin density but did not improve EEG maturation or neuronal or oligodendrocyte survival.
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Affiliation(s)
- Robert Galinsky
- Department of PhysiologyUniversity of AucklandAucklandNew Zealand
- The Ritchie CentreHudson Institute of Medical ResearchClaytonVictoriaAustralia
- Department of Obstetrics and GynaecologyMonash UniversityVictoriaAustralia
| | | | - Sharmony B. Kelly
- The Ritchie CentreHudson Institute of Medical ResearchClaytonVictoriaAustralia
- Department of Obstetrics and GynaecologyMonash UniversityVictoriaAustralia
| | - Guido Wassink
- Department of PhysiologyUniversity of AucklandAucklandNew Zealand
| | | | | | | | - Laura Bennet
- Department of PhysiologyUniversity of AucklandAucklandNew Zealand
| | - Alistair J. Gunn
- Department of PhysiologyUniversity of AucklandAucklandNew Zealand
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9
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Lear CA, Westgate JA, Bennet L, Ugwumadu A, Stone PR, Tournier A, Gunn AJ. Fetal defenses against intrapartum head compression-implications for intrapartum decelerations and hypoxic-ischemic injury. Am J Obstet Gynecol 2023; 228:S1117-S1128. [PMID: 34801443 DOI: 10.1016/j.ajog.2021.11.1352] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 11/05/2021] [Accepted: 11/14/2021] [Indexed: 01/27/2023]
Abstract
Uterine contractions during labor and engagement of the fetus in the birth canal can compress the fetal head. Its impact on the fetus is unclear and still controversial. In this integrative physiological review, we highlight evidence that decelerations are uncommonly associated with fetal head compression. Next, the fetus has an impressive ability to adapt to increased intracranial pressure through activation of the intracranial baroreflex, such that fetal cerebral perfusion is well-maintained during labor, except in the setting of prolonged systemic hypoxemia leading to secondary cardiovascular compromise. Thus, when it occurs, fetal head compression is not necessarily benign but does not seem to be a common contributor to intrapartum decelerations. Finally, the intracranial baroreflex and the peripheral chemoreflex (the response to acute hypoxemia) have overlapping efferent effects. We propose the hypothesis that these reflexes may work synergistically to promote fetal adaptation to labor.
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Affiliation(s)
- Christopher A Lear
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Jenny A Westgate
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand; Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Austin Ugwumadu
- Department of Obstetrics and Gynaecology, St. George's University of London, London, United Kingdom
| | - Peter R Stone
- Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, New Zealand
| | - Alexane Tournier
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand; Department of Paediatrics, Starship Children's Hospital, Auckland, New Zealand.
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10
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Lear BA, Lear CA, Dhillon SK, Davidson JO, Gunn AJ, Bennet L. Evolution of grey matter injury over 21 days after hypoxia-ischaemia in preterm fetal sheep. Exp Neurol 2023; 363:114376. [PMID: 36889575 DOI: 10.1016/j.expneurol.2023.114376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/05/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023]
Abstract
Reduced grey matter volume in preterm infants is associated with later disability, but its time course and relationship with white matter injury are not well understood. We recently showed that moderate-severe hypoxia-ischaemia (HI) in preterm fetal sheep led to severe cystic injury 2-3 weeks later. In the same cohort we now show profound hippocampal neuronal loss from 3 days after HI. By contrast, reduction in cortical area and perimeter developed much more slowly, with maximum reduction at day 21. There was transient upregulation of cleaved caspase-3-positive apoptosis in the cortex at day 3 but no change in neuronal density or macroscopic injury of the cortex. Both microglia and astrocytes were transiently upregulated in the grey matter. EEG power was initially profoundly suppressed but partially recovered by 21 days of recovery, and final power was correlated with white matter area (p < 0.001, r2 = 0.75, F = 24.19), cortical area (p = 0.004, r2 = 0.44, F = 11.90) and hippocampi area (p = 0.049, r2 = 0.23, F = 4.58). In conclusion, the present study suggests that in preterm fetal sheep, hippocampal injury is established within a few days of acute HI, but impaired cortical growth develops slowly, in a similar time course to severe white matter injury.
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Affiliation(s)
- Benjamin A Lear
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Christopher A Lear
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Simerdeep K Dhillon
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Joanne O Davidson
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand.
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11
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Green EA, Metz D, Galinsky R, Atkinson R, Skuza EM, Clark M, Gunn AJ, Kirkpatrick CM, Hunt RW, Berger PJ, Nold-Petry CA, Nold MF. Anakinra Pilot - a clinical trial to demonstrate safety, feasibility and pharmacokinetics of interleukin 1 receptor antagonist in preterm infants. Front Immunol 2022; 13:1022104. [PMID: 36389766 PMCID: PMC9647081 DOI: 10.3389/fimmu.2022.1022104] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 10/10/2022] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND Bronchopulmonary dysplasia (BPD), its complication pulmonary hypertension (BPD-PH) and preterm brain and gut injury lead to significant morbidity and mortality in infants born extremely prematurely. There is extensive evidence that the pro-inflammatory cytokine interleukin 1 (IL-1) plays a key role in the pathophysiology of these illnesses. Two decades of clinical use in paediatric and adult medicine have established an excellent safety and efficacy record for IL-1 blockade with IL-1 receptor antagonist (IL-1Ra, medication name anakinra). Building on robust pre-clinical evidence, the Anakinra Pilot trial aims to demonstrate safety and feasibility of administering anakinra to preterm infants, and to establish pharmacokinetics in this population. Its ultimate goal is to facilitate large studies that will test whether anakinra can ameliorate early-life inflammation, thus alleviating multiple complications of prematurity. METHODS AND ANALYSIS Anakinra Pilot is an investigator-initiated, single arm, safety and feasibility dose-escalation trial in extremely preterm infants born between 24 weeks 0 days (240) and 276 weeks of gestational age (GA). Enrolled infants will receive anakinra intravenously over the first 21 days after birth, starting in the first 24 h after birth. In the first phase, dosing is 1 mg/kg every 48 h, and dosage will increase to 1.5 mg/kg every 24 h in the second phase. Initial anakinra dosing was determined through population pharmacokinetic model simulations. During the study, there will be a interim analysis to confirm predictions before undertaking dose assessment. Anakinra therapy will be considered safe if the frequency of adverse outcomes/events does not exceed that expected in infants born at 240-276 weeks GA. CLINICAL TRIAL REGISTRATION https://clinicaltrials.gov/, identifier NCT05280340.
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Affiliation(s)
- Elys A. Green
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Monash Newborn, Monash Children’s Hospital, Melbourne, VIC, Australia
| | - David Metz
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
- Monash Children’s Hospital, Melbourne, VIC, Australia
- Murdoch Children’s Research Institute, Melbourne, VIC, Australia
| | - Robert Galinsky
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Rebecka Atkinson
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Monash Newborn, Monash Children’s Hospital, Melbourne, VIC, Australia
| | - Elizbeth M. Skuza
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Megan Clark
- Monash Newborn, Monash Children’s Hospital, Melbourne, VIC, Australia
- Faculty of Pharmacy and Pharmaceutical Science, Monash University, Melbourne, VIC, Australia
| | - Alistair J Gunn
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Carl M. Kirkpatrick
- Monash Institute for Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Rod W. Hunt
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Monash Newborn, Monash Children’s Hospital, Melbourne, VIC, Australia
| | - Philip J. Berger
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Claudia A. Nold-Petry
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Marcel F. Nold
- Department of Paediatrics, Monash University, Melbourne, VIC, Australia
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Monash Newborn, Monash Children’s Hospital, Melbourne, VIC, Australia
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12
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Dhillon SK, Gunn ER, Lear BA, King VJ, Lear CA, Wassink G, Davidson JO, Bennet L, Gunn AJ. Cerebral Oxygenation and Metabolism After Hypoxia-Ischemia. Front Pediatr 2022; 10:925951. [PMID: 35903161 PMCID: PMC9314655 DOI: 10.3389/fped.2022.925951] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/15/2022] [Indexed: 11/13/2022] Open
Abstract
Perinatal hypoxia-ischemia (HI) is still a significant contributor to mortality and adverse neurodevelopmental outcomes in term and preterm infants. HI brain injury evolves over hours to days, and involves complex interactions between the endogenous protective and pathological processes. Understanding the timing of evolution of injury is vital to guide treatment. Post-HI recovery is associated with a typical neurophysiological profile, with stereotypic changes in cerebral perfusion and oxygenation. After the initial recovery, there is a delayed, prolonged reduction in cerebral perfusion related to metabolic suppression, followed by secondary deterioration with hyperperfusion and increased cerebral oxygenation, associated with altered neurovascular coupling and impaired cerebral autoregulation. These changes in cerebral perfusion are associated with the stages of evolution of injury and injury severity. Further, iatrogenic factors can also affect cerebral oxygenation during the early period of deranged metabolism, and improving clinical management may improve neuroprotection. We will review recent evidence that changes in cerebral oxygenation and metabolism after HI may be useful biomarkers of prognosis.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Alistair J. Gunn
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
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13
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Persistent cortical and white matter inflammation after therapeutic hypothermia for ischemia in near-term fetal sheep. J Neuroinflammation 2022; 19:139. [PMID: 35690757 PMCID: PMC9188214 DOI: 10.1186/s12974-022-02499-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 05/23/2022] [Indexed: 02/07/2023] Open
Abstract
Background Therapeutic hypothermia significantly improves outcomes after moderate–severe hypoxic-ischemic encephalopathy (HIE), but it is partially effective. Although hypothermia is consistently associated with reduced microgliosis, it is still unclear whether it normalizes microglial morphology and phenotype. Methods Near-term fetal sheep (n = 24) were randomized to sham control, ischemia-normothermia, or ischemia-hypothermia. Brain sections were immunohistochemically labeled to assess neurons, microglia and their interactions with neurons, astrocytes, myelination, and gitter cells (microglia with cytoplasmic lipid granules) 7 days after cerebral ischemia. Lesions were defined as areas with complete loss of cells. RNAscope® was used to assess microglial phenotype markers CD86 and CD206. Results Ischemia-normothermia was associated with severe loss of neurons and myelin (p < 0.05), with extensive lesions, astrogliosis and microgliosis with a high proportion of gitter cells (p < 0.05). Microglial wrapping of neurons was present in both the ischemia groups. Hypothermia improved neuronal survival, suppressed lesions, gitter cells and gliosis (p < 0.05), and attenuated the reduction of myelin area fraction. The “M1” marker CD86 and “M2” marker CD206 were upregulated after ischemia. Hypothermia partially suppressed CD86 in the cortex only (p < 0.05), but did not affect CD206. Conclusions Hypothermia prevented lesions after cerebral ischemia, but only partially suppressed microglial wrapping and M1 marker expression. These data support the hypothesis that persistent upregulation of injurious microglial activity may contribute to partial neuroprotection after hypothermia, and that immunomodulation after rewarming may be an important therapeutic target.
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14
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Chen X, Zhang J, Wu Y, Tucker R, Baird GL, Domonoske R, Barrios-Anderson A, Lim YP, Bath K, Walsh EG, Stonestreet BS. Inter-alpha Inhibitor Proteins Ameliorate Brain Injury and Improve Behavioral Outcomes in a Sex-Dependent Manner After Exposure to Neonatal Hypoxia Ischemia in Newborn and Young Adult Rats. Neurotherapeutics 2022; 19:528-549. [PMID: 35290609 PMCID: PMC9226254 DOI: 10.1007/s13311-022-01217-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2022] [Indexed: 12/16/2022] Open
Abstract
Hypoxic-ischemic (HI) brain injury is a major contributor to neurodevelopmental morbidities. Inter-alpha inhibitor proteins (IAIPs) have neuroprotective effects on HI-related brain injury in neonatal rats. However, the effects of treatment with IAIPs on sequential behavioral, MRI, and histopathological abnormalities in the young adult brain after treatment with IAIPs in neonates remain to be determined. The objective of this study was to examine the neuroprotective effects of IAIPs at different neurodevelopmental stages from newborn to young adults after exposure of neonates to HI injury. IAIPs were given as 11-sequential 30-mg/kg doses to postnatal (P) day 7-21 rats after right common carotid artery ligation and exposure to 90 min of 8% oxygen. The resulting brain edema and injury were examined by T2-weighted magnetic resonance imaging (MRI) and cresyl violet staining, respectively. The mean T2 values of the ipsilateral hemisphere from MRI slices 6 to 10 were reduced in IAIP-treated HI males + females on P8, P9, and P10 and females on P8, P9, P10, and P14. IAIP treatment reduced hemispheric volume atrophy by 44.5 ± 29.7% in adult male + female P42 rats and improved general locomotor abilities measured by the righting reflex over time at P7.5, P8, and P9 in males + females and males and muscle strength/endurance measured by wire hang on P16 in males + females and females. IAIPs provided beneficial effects during the learning phase of the Morris water maze with females exhibiting beneficial effects. IAIPs confer neuroprotection from HI-related brain injury in neonates and even in adult rats and beneficial MRI and behavioral benefits in a sex-dependent manner.
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Affiliation(s)
- Xiaodi Chen
- Department of Pediatrics, Infants Hospital of Rhode Island, Warren Alpert Medical School of Brown University, Women &101 Dudley Street, Providence, RI, 02905-2499, USA
| | - Jiyong Zhang
- Department of Pediatrics, Infants Hospital of Rhode Island, Warren Alpert Medical School of Brown University, Women &101 Dudley Street, Providence, RI, 02905-2499, USA
| | - Yuqi Wu
- Department of Pediatrics, Infants Hospital of Rhode Island, Warren Alpert Medical School of Brown University, Women &101 Dudley Street, Providence, RI, 02905-2499, USA
| | - Richard Tucker
- Department of Pediatrics, Infants Hospital of Rhode Island, Warren Alpert Medical School of Brown University, Women &101 Dudley Street, Providence, RI, 02905-2499, USA
| | - Grayson L Baird
- Department of Diagnostic Imaging, Biostatistics Core Lifespan Hospital System, Rhode Island Hospital, Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Rose Domonoske
- Department of Pediatrics, Infants Hospital of Rhode Island, Warren Alpert Medical School of Brown University, Women &101 Dudley Street, Providence, RI, 02905-2499, USA
| | - Adriel Barrios-Anderson
- Department of Pediatrics, Infants Hospital of Rhode Island, Warren Alpert Medical School of Brown University, Women &101 Dudley Street, Providence, RI, 02905-2499, USA
| | - Yow-Pin Lim
- ProThera Biologics, Inc, Providence, RI, USA
- Department of Pathology and Laboratory Medicine, Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Kevin Bath
- Division of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY, USA
- Department of Psychiatry, Columbia University Irving Medical College, New York, NY, USA
| | - Edward G Walsh
- Department of Neuroscience, Brown University, Providence, RI, USA
| | - Barbara S Stonestreet
- Department of Pediatrics, Infants Hospital of Rhode Island, Warren Alpert Medical School of Brown University, Women &101 Dudley Street, Providence, RI, 02905-2499, USA.
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