1
|
Cho KH, Fraser M, Xu B, Dean JM, Gunn AJ, Bennet L. Induction of Tertiary Phase Epileptiform Discharges after Postasphyxial Infusion of a Toll-Like Receptor 7 Agonist in Preterm Fetal Sheep. Int J Mol Sci 2021; 22:ijms22126593. [PMID: 34205464 PMCID: PMC8234830 DOI: 10.3390/ijms22126593] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/16/2021] [Accepted: 06/17/2021] [Indexed: 01/30/2023] Open
Abstract
Background: Toll-like receptor (TLR) agonists are key immunomodulatory factors that can markedly ameliorate or exacerbate hypoxic–ischemic brain injury. We recently demonstrated that central infusion of the TLR7 agonist Gardiquimod (GDQ) following asphyxia was highly neuroprotective after 3 days but not 7 days of recovery. We hypothesize that this apparent transient neuroprotection is associated with modulation of seizure-genic processes and hemodynamic control. Methods: Fetuses received sham asphyxia or asphyxia induced by umbilical cord occlusion (20.9 ± 0.5 min) and were monitored continuously for 7 days. GDQ 3.34 mg or vehicle were infused intracerebroventricularly from 1 to 4 h after asphyxia. Results: GDQ infusion was associated with sustained moderate hypertension that resolved after 72 h recovery. Electrophysiologically, GDQ infusion was associated with reduced number and burden of postasphyxial seizures in the first 18 h of recovery (p < 0.05). Subsequently, GDQ was associated with induction of slow rhythmic epileptiform discharges (EDs) from 72 to 96 h of recovery (p < 0.05 vs asphyxia + vehicle). The total burden of EDs was associated with reduced numbers of neurons in the caudate nucleus (r2 = 0.61, p < 0.05) and CA1/2 hippocampal region (r2 = 0.66, p < 0.05). Conclusion: These data demonstrate that TLR7 activation by GDQ modulated blood pressure and suppressed seizures in the early phase of postasphyxial recovery, with subsequent prolonged induction of epileptiform activity. Speculatively, this may reflect delayed loss of early protection or contribute to differential neuronal survival in subcortical regions.
Collapse
Affiliation(s)
- Kenta H.T. Cho
- The Department of Physiology, The University of Auckland, Auckland 1023, New Zealand; (K.H.T.C.); (M.F.); (J.M.D.); (L.B.)
| | - Mhoyra Fraser
- The Department of Physiology, The University of Auckland, Auckland 1023, New Zealand; (K.H.T.C.); (M.F.); (J.M.D.); (L.B.)
| | - Bing Xu
- Shenzhen Bay Laboratory, Shenzhen 518118, China;
| | - Justin M. Dean
- The Department of Physiology, The University of Auckland, Auckland 1023, New Zealand; (K.H.T.C.); (M.F.); (J.M.D.); (L.B.)
| | - Alistair J. Gunn
- The Department of Physiology, The University of Auckland, Auckland 1023, New Zealand; (K.H.T.C.); (M.F.); (J.M.D.); (L.B.)
- Correspondence: ; Tel.: +64-9-373-7499
| | - Laura Bennet
- The Department of Physiology, The University of Auckland, Auckland 1023, New Zealand; (K.H.T.C.); (M.F.); (J.M.D.); (L.B.)
| |
Collapse
|
2
|
Ayoub D, Elmashad A, Rowisha M, Eltomey M, El Amrousy D. Hemodynamic effects of high-frequency oscillatory ventilation in preterm neonates with respiratory distress syndrome. Pediatr Pulmonol 2021; 56:424-432. [PMID: 33289301 DOI: 10.1002/ppul.25195] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/28/2020] [Accepted: 11/27/2020] [Indexed: 02/05/2023]
Abstract
BACKGROUND High-frequency oscillatory ventilation (HFOV) can have negative hemodynamic effects in neonates. We aimed to assess systemic, cerebral, and cardiac hemodynamic changes in preterm neonates with respiratory distress syndrome (RDS) on HFOV. METHODS This observational study was conducted from June 2017 until May 2019 on 100 preterm neonates with RDS that needed switching from conventional mechanical ventilation to HFOV. Initial and Follow up capillary blood gas, echocardiographic examination, cranial ultrasound, and Doppler study of cerebral, celiac, superior mesenteric, and renal arteries using resistive index (RI) were performed before, 24 h, and 72 h after the use of HFOV. RESULTS There was no statistically significant difference as regards cardiac function, heart rate, or intraventricular hemorrhage on follow up measurements. However blood pressure, left ventricular dimensions, and volumes statistically increased after HFOV. There was a statistically significant decrease in the pulmonary artery systolic pressure after the use of HFOV. After the use of HFOV, there was a statistically significant increase in the superior vena cava flow and left ventricular output while right ventricular output values initially increased then slightly decreased but still higher than the initial values. RI of cerebral, superior mesenteric, celiac, and renal arteries significantly decreased on follow up measurements which reflected increased blood flow in these arteries. CONCLUSION HFOV had no negative effect on the cerebral, systemic, or cardiac hemodynamics when applied at optimum MAP. Therefore, concerns about negative hemodynamic effects of HFOV should not discourage the use of HFOV when deemed clinically indicated provided the use of optimum MAP.
Collapse
Affiliation(s)
- Dalia Ayoub
- Pediatric Department, Tanta University Hospital, Tanta, Egypt
| | | | - Mohamed Rowisha
- Pediatric Department, Tanta University Hospital, Tanta, Egypt
| | - Mohamed Eltomey
- Diagnostic Radiology Department, Tanta University Hospital, Tanta, Egypt
| | - Doaa El Amrousy
- Pediatric Department, Tanta University Hospital, Tanta, Egypt
| |
Collapse
|
3
|
Abstract
Neonatal nephron loss may follow hypoxic-ischemic events or nephrotoxic medications. Its long-term effects on the kidney are still unclear. Unlike term infants, preterm neonates less than 36 weeks gestational age show ongoing nephrogenesis. We hypothesized that nephron loss during nephrogenesis leads to more severe renal sequelae than nephron loss shortly after the completion of nephrogenesis. Rats show nephrogenesis until day 10 of life resembling the situation of preterm infants. Animals were uninephrectomized at day 1 (UNX d1) resulting in nephron reduction during nephrogenesis and at day 14 of life (UNX d14) inducing nephron loss after the completion of nephrogenesis. 28 days after uninephrectomy the compensatory renal growth was higher in UNX d1 compared to UNX d14. Nephrin was reduced and collagen deposition increased in UNX d1. At 1 year of age, glomerulosclerosis and markers of tubulointerstitial damage were most prevalent in UNX d1. Moreover, the number of desmin-positive podocytes was higher and nephrin was reduced in UNX d1 indicating podocyte damage. Infiltration of inflammatory cells was heightened after UNX d1. Uninephrectomized animals showed no arterial hypertension. We conclude that neonatal nephron loss during active nephrogenesis leads to more severe glomerular and tubulointerstitial damage, which is not a consequence of compensatory arterial hypertension.
Collapse
|
4
|
Galinsky R, Lear CA, Dean JM, Wassink G, Dhillon SK, Fraser M, Davidson JO, Bennet L, Gunn AJ. Complex interactions between hypoxia-ischemia and inflammation in preterm brain injury. Dev Med Child Neurol 2018; 60:126-133. [PMID: 29194585 DOI: 10.1111/dmcn.13629] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/17/2017] [Indexed: 12/12/2022]
Abstract
UNLABELLED Children surviving preterm birth have a high risk of disability, particularly cognitive and learning problems. There is extensive clinical and experimental evidence that disability is now primarily related to dysmaturation of white and gray matter, defined by failure of oligodendrocyte maturation and neuronal dendritic arborization, rather than cell death alone. The etiology of this dysmaturation is multifactorial, with contributions from hypoxia-ischemia, infection/inflammation and barotrauma. Intriguingly, these factors can interact to both increase and decrease damage. In this review we summarize preclinical and clinical evidence that all of these factors trigger secondary or chronic inflammation and gliosis. Thus, we hypothesize that these shared pathological features play a key role in a final common pathway that leads to the impaired neural maturation and connectivity and cognitive/motor impairments that are commonly observed in infants born preterm. This raises the possibility that secondary or chronic inflammation may be a viable therapeutic target for delayed interventions to improve neurodevelopmental outcomes after preterm birth. WHAT THIS PAPER ADDS Hypoxia-ischemia, infection/inflammation, and barotrauma/volutrauma all contribute to preterm brain injury. Multiple different triggers of preterm brain injury are associated with central nervous system dysmaturation. Secondary brain inflammation may be a viable target to improve neurodevelopment after preterm birth.
Collapse
Affiliation(s)
- Robert Galinsky
- The Department of Physiology, University of Auckland, Auckland, New Zealand.,The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Christopher A Lear
- The Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Justin M Dean
- The Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Guido Wassink
- The Department of Physiology, University of Auckland, Auckland, New Zealand
| | | | - Mhoyra Fraser
- The Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Joanne O Davidson
- The Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- The Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- The Department of Physiology, University of Auckland, Auckland, New Zealand
| |
Collapse
|
5
|
Joynt C, Cheung PY. Cardiovascular Supportive Therapies for Neonates With Asphyxia - A Literature Review of Pre-clinical and Clinical Studies. Front Pediatr 2018; 6:363. [PMID: 30619782 PMCID: PMC6295641 DOI: 10.3389/fped.2018.00363] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 11/08/2018] [Indexed: 12/13/2022] Open
Abstract
Asphyxiated neonates often have hypotension, shock, and poor tissue perfusion. Various "inotropic" medications are used to provide cardiovascular support to improve the blood pressure and to treat shock. However, there is incomplete literature on the examination of hemodynamic effects of these medications in asphyxiated neonates, especially in the realm of clinical studies (mostly in late preterm or term populations). Although the extrapolation of findings from animal studies and other clinical populations such as children and adults require caution, it seems appropriate that findings from carefully conducted pre-clinical studies are important in answering some of the fundamental knowledge gaps. Based on a literature search, this review discusses the current available information, from both clinical studies and animal models of neonatal asphyxia, on common medications used to provide hemodynamic support including dopamine, dobutamine, epinephrine, milrinone, norepinephrine, vasopressin, levosimendan, and hydrocortisone.
Collapse
Affiliation(s)
- Chloe Joynt
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
| | - Po-Yin Cheung
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada.,Department of Pharmacology, University of Alberta, Edmonton, AB, Canada.,Centre for the Study of Asphyxia and Resuscitation, Edmonton, AB, Canada
| |
Collapse
|
6
|
Duke T, Subhi R, Peel D, Frey B. Pulse oximetry: technology to reduce child mortality in developing countries. ACTA ACUST UNITED AC 2013; 29:165-75. [DOI: 10.1179/027249309x12467994190011] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
|
7
|
Bennet L, Booth LC, Drury PP, Quaedackers JSL, Gunn AJ. Preterm neonatal cardiovascular instability: Does understanding the fetus help evaluate the newborn? Clin Exp Pharmacol Physiol 2012; 39:965-72. [DOI: 10.1111/j.1440-1681.2012.05744.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Laura Bennet
- Fetal Physiology and Neuroscience Group; Department of Physiology; Faculty of Medical and Health; The University of Auckland; Auckland; New Zealand
| | - Lindsea C Booth
- Neurobiology Division; Florey Neuroscience Institutes; University of Melbourne; Melbourne; Victoria; Australia
| | - Paul P Drury
- Fetal Physiology and Neuroscience Group; Department of Physiology; Faculty of Medical and Health; The University of Auckland; Auckland; New Zealand
| | - Josine SL Quaedackers
- Fetal Physiology and Neuroscience Group; Department of Physiology; Faculty of Medical and Health; The University of Auckland; Auckland; New Zealand
| | - Alistair J Gunn
- Fetal Physiology and Neuroscience Group; Department of Physiology; Faculty of Medical and Health; The University of Auckland; Auckland; New Zealand
| |
Collapse
|
8
|
Booth LC, Malpas SC, Barrett CJ, Guild SJ, Gunn AJ, Bennet L. Renal sympathetic nerve activity during asphyxia in fetal sheep. Am J Physiol Regul Integr Comp Physiol 2012; 303:R30-8. [PMID: 22552793 DOI: 10.1152/ajpregu.00063.2012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The sympathetic nervous system (SNS) is an important mediator of fetal adaptation to life-threatening in utero challenges, such as asphyxia. Although the SNS is active well before term, SNS responses mature significantly over the last third of gestation, and its functional contribution to adaptation to asphyxia over this critical period of life remains unclear. Therefore, we examined the hypotheses that increased renal sympathetic nerve activity (RSNA) is the primary mediator of decreased renal vascular conductance (RVC) during complete umbilical cord occlusion in preterm fetal sheep (101 ± 1 days; term 147 days) and that near-term fetuses (119 ± 0 days) would have a more rapid initial vasomotor response, with a greater increase in RSNA. Causality of the relationship of RSNA and RVC was investigated using surgical (preterm) and chemical (near-term) denervation. All fetal sheep showed a significant increase in RSNA with occlusion, which was more sustained but not significantly greater near-term. The initial fall in RVC was more rapid in near-term than preterm fetal sheep and preceded the large increase in RSNA. These data suggest that although RSNA can increase as early as 0.7 gestation, it is not the primary determinant of RVC. This finding was supported by denervation studies. Interestingly, chemical denervation in near-term fetal sheep was associated with an initial fall in blood pressure, suggesting that by 0.8 gestation sympathetic innervation of nonrenal vascular beds is critical to maintain arterial blood pressure during the rapid initial adaptation to asphyxia.
Collapse
Affiliation(s)
- Lindsea C Booth
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | | | | | | | | | | |
Collapse
|
9
|
Booth LC, Gunn AJ, Malpas SC, Barrett CJ, Davidson JO, Guild SJ, Bennet L. Baroreflex control of renal sympathetic nerve activity and heart rate in near-term fetal sheep. Exp Physiol 2011; 96:736-44. [DOI: 10.1113/expphysiol.2011.058354] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
10
|
Joynt C, Bigam DL, Charrois G, Jewell LD, Korbutt G, Cheung PY. Milrinone, dobutamine or epinephrine use in asphyxiated newborn pigs resuscitated with 100% oxygen. Intensive Care Med 2010; 36:1058-66. [DOI: 10.1007/s00134-010-1820-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Accepted: 11/28/2009] [Indexed: 11/24/2022]
|
11
|
Booth LC, Malpas SC, Barrett CJ, Guild SJ, Gunn AJ, Bennet L. Is baroreflex control of sympathetic activity and heart rate active in the preterm fetal sheep? Am J Physiol Regul Integr Comp Physiol 2009; 296:R603-9. [DOI: 10.1152/ajpregu.90624.2008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The arterial baroreflex is a fundamental reflex that buffers rapid changes in arterial blood pressure (BP) via regulation of the heart rate and sympathetic nerve activity to the vasculature. In adults a sigmoidal relationship between BP and both heart rate and sympathetic nerve activity is well documented. Its role in blood pressure control before birth is unclear. Preterm babies have a high incidence of low BP, especially in the first few days of life, which could be related, in part, to immaturity of the baroreflex. In the present study, we investigated the baroreflex control of fetal heart rate and renal sympathetic nerve activity (RSNA) in preterm fetal sheep in utero (102 ± 1 days of gestation; term 140 days). Phenylephrine was associated with a significant increase in BP from 38 ± 2 to 58 ± 3 mmHg and a decrease in heart rate (HR) from 177 ± 4 to 116 ± 8 beats per minute (bpm). Sodium nitroprusside was associated with a significant fall in BP from 38 ± 2 to 26 ± 1 mmHg and an increase in HR from 182 ± 4 to 274 ± 8 bpm. However, the time between the 50% changes in BP and HR was significantly greater after hypotension than hypertension (31 ± 8 s vs. 14 ± 5 s, P < 0.05). No significant changes in RSNA occurred with either stimulus. This suggests that there are different maturational tempos for the components of the central autonomic response to altered blood pressure.
Collapse
|
12
|
INTESTINAL HEMODYNAMIC EFFECTS OF MILRINONE IN ASPHYXIATED NEWBORN PIGS AFTER REOXYGENATION WITH 100% OXYGEN. Shock 2009; 31:292-9. [DOI: 10.1097/shk.0b013e31817fd752] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
13
|
Dose-response effects of milrinone on hemodynamics of newborn pigs with hypoxia-reoxygenation. Intensive Care Med 2008; 34:1321-9. [DOI: 10.1007/s00134-008-1060-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Accepted: 02/01/2008] [Indexed: 11/25/2022]
|
14
|
Hack KEA, Derks JB, Elias SG, Franx A, Roos EJ, Voerman SK, Bode CL, Koopman-Esseboom C, Visser GHA. Increased perinatal mortality and morbidity in monochorionic versus dichorionic twin pregnancies: clinical implications of a large Dutch cohort study. BJOG 2007; 115:58-67. [PMID: 17999692 DOI: 10.1111/j.1471-0528.2007.01556.x] [Citation(s) in RCA: 254] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To evaluate mortality and morbidity in a large cohort of twin pregnancies according to chorionicity. We aimed to estimate the optimal time of delivery. DESIGN Historical cohort design. Setting Two teaching hospitals. POPULATION Twin pregnancies delivered in the University Medical Centre, Utrecht, and the St Elisabeth Hospital, Tilburg (1995-2004), The Netherlands (n = 1407). METHODS Pregnancy outcomes were documented according to chorionicity. Mortality >/=32 weeks was reviewed carefully with special attention to antenatal fetal monitoring, autopsy and placental histopathology to find an explanation for adverse outcome. MAIN OUTCOME MEASURES Perinatal mortality and morbidity in monochorionic (MC) and dichorionic (DC) twins. RESULTS Perinatal mortality was 11.6% in MC twin pregnancies and 5.0% in DC twin pregnancies. After 32 weeks, the risk of intrauterine death (IUD) was significantly higher in MC twins than in DC twins (hazard ratio 8.8, 95% CI 2.7-28.9). In most of these cases of IUD, no antenatal signs of impaired fetal condition had been present. Median gestational age was 1 week longer in DC twins than in MC twins, and the mean birthweight was 221 g higher. Severe birthweight discordancy (>20%) occurred more often in MC twins than in DC twins (OR 1.23, 95% CI 0.97-1.55). The incidence of necrotising enterocolitis (NEC) was higher in MC twins, after adjustment for age and weight at birth (OR 4.05, 95% CI 1.97-8.35). There was a trend towards higher neuromorbidity in MC twins. CONCLUSIONS This is the largest cohort study of twin pregnancies evaluating outcome according to chorionicity thus far. MC twins are at increased risk for fetal death (even at term), NEC and neuromorbidity. Current antenatal care is insufficient to predict and prevent this excess perinatal mortality and morbidity. Planned delivery at or even before 37 weeks of gestation seems to be justified for MC twins.
Collapse
Affiliation(s)
- K E A Hack
- Department of Obstetrics, Wilhelmina Children's Hospital, University Medical Centre Utrecht, Utrecht, The Netherlands.
| | | | | | | | | | | | | | | | | |
Collapse
|