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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] [What about the content of this article? (0)] [Affiliation(s)] [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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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] [What about the content of this article? (0)] [Affiliation(s)] [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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King VJ, Bennet L, Stone PR, Clark A, Gunn AJ, Dhillon SK. Fetal growth restriction and stillbirth: Biomarkers for identifying at risk fetuses. Front Physiol 2022; 13:959750. [PMID: 36060697 PMCID: PMC9437293 DOI: 10.3389/fphys.2022.959750] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 07/29/2022] [Indexed: 11/13/2022] Open
Abstract
Fetal growth restriction (FGR) is a major cause of stillbirth, prematurity and impaired neurodevelopment. Its etiology is multifactorial, but many cases are related to impaired placental development and dysfunction, with reduced nutrient and oxygen supply. The fetus has a remarkable ability to respond to hypoxic challenges and mounts protective adaptations to match growth to reduced nutrient availability. However, with progressive placental dysfunction, chronic hypoxia may progress to a level where fetus can no longer adapt, or there may be superimposed acute hypoxic events. Improving detection and effective monitoring of progression is critical for the management of complicated pregnancies to balance the risk of worsening fetal oxygen deprivation in utero, against the consequences of iatrogenic preterm birth. Current surveillance modalities include frequent fetal Doppler ultrasound, and fetal heart rate monitoring. However, nearly half of FGR cases are not detected in utero, and conventional surveillance does not prevent a high proportion of stillbirths. We review diagnostic challenges and limitations in current screening and monitoring practices and discuss potential ways to better identify FGR, and, critically, to identify the “tipping point” when a chronically hypoxic fetus is at risk of progressive acidosis and stillbirth.
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Affiliation(s)
- Victoria J. King
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Peter R. Stone
- Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, New Zealand
| | - Alys Clark
- Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, New Zealand
- Auckland Biomedical Engineering Institute, 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
| | - Simerdeep K. Dhillon
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand
- *Correspondence: Simerdeep K. Dhillon,
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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: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Lear CA, Bennet L, King VJ, Gunn AJ. Letter to the editor regarding "The influence of melatonin on the heart rhythm - An in vitro simulation with murine embryonic stem cell derived cardiomyocytes". Biomed Pharmacother 2021; 137:111398. [PMID: 33761614 DOI: 10.1016/j.biopha.2021.111398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 02/10/2021] [Indexed: 11/19/2022] Open
Affiliation(s)
- Christopher A Lear
- Fetal Physiology and Neuroscience Group, Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, 85 Park Road, Grafton, Auckland 1023, New Zealand
| | - Laura Bennet
- Fetal Physiology and Neuroscience Group, Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, 85 Park Road, Grafton, Auckland 1023, New Zealand
| | - Victoria J King
- Fetal Physiology and Neuroscience Group, Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, 85 Park Road, Grafton, Auckland 1023, New Zealand
| | - Alistair J Gunn
- Fetal Physiology and Neuroscience Group, Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, 85 Park Road, Grafton, Auckland 1023, New Zealand.
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Galinsky R, van de Looij Y, Mitchell N, Dean JM, Dhillon SK, Yamaguchi K, Lear CA, Wassink G, Davidson JO, Nott F, Zahra VA, Kelly SB, King VJ, Sizonenko SV, Bennet L, Gunn AJ. Magnetic Resonance Imaging Correlates of White Matter Gliosis and Injury in Preterm Fetal Sheep Exposed to Progressive Systemic Inflammation. Int J Mol Sci 2020; 21:ijms21238891. [PMID: 33255257 PMCID: PMC7727662 DOI: 10.3390/ijms21238891] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/17/2020] [Accepted: 11/19/2020] [Indexed: 12/17/2022] Open
Abstract
Progressive fetal infection/inflammation is strongly associated with neural injury after preterm birth. We aimed to test the hypotheses that progressively developing fetal inflammation leads to neuroinflammation and impaired white matter development and that the histopathological changes can be detected using high-field diffusion tensor magnetic resonance imaging (MRI). Chronically instrumented preterm fetal sheep at 0.7 of gestation were randomly assigned to receive intravenous saline (control; n = 6) or a progressive infusion of lipopolysaccharide (LPS, 200 ng intravenous over 24 h then doubled every 24 h for 5 days to induce fetal inflammation, n = 7). Sheep were killed 10 days after starting the infusions, for histology and high-field diffusion tensor MRI. Progressive LPS infusion was associated with increased circulating interleukin (IL)-6 concentrations and moderate increases in carotid artery perfusion and the frequency of electroencephalogram (EEG) activity (p < 0.05 vs. control). In the periventricular white matter, fractional anisotropy (FA) was increased, and orientation dispersion index (ODI) was reduced (p < 0.05 vs. control for both). Histologically, in the same brain region, LPS infusion increased microglial activation and astrocyte numbers and reduced the total number of oligodendrocytes with no change in myelination or numbers of immature/mature oligodendrocytes. Numbers of astrocytes in the periventricular white matter were correlated with increased FA and reduced ODI signal intensities. Astrocyte coherence was associated with increased FA. Moderate astrogliosis, but not loss of total oligodendrocytes, after progressive fetal inflammation can be detected with high-field diffusion tensor MRI.
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Affiliation(s)
- Robert Galinsky
- Department of Physiology, University of Auckland, Auckland 1023, New Zealand; (R.G.); (N.M.); (J.M.D.); (S.K.D.); (K.Y.); (C.A.L.); (G.W.); (J.O.D.); (V.J.K.); (L.B.)
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria 3168, Australia; (F.N.); (V.A.Z.); (S.B.K.)
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria 3800, Australia
| | - Yohan van de Looij
- Division of Child Development & Growth, Department of Pediatrics, Gynaecology & Obstetrics, School of Medicine, University of Geneva, 1015 Geneva, Switzerland; (Y.v.d.L.); (S.V.S.)
| | - Natasha Mitchell
- Department of Physiology, University of Auckland, Auckland 1023, New Zealand; (R.G.); (N.M.); (J.M.D.); (S.K.D.); (K.Y.); (C.A.L.); (G.W.); (J.O.D.); (V.J.K.); (L.B.)
| | - Justin M. Dean
- Department of Physiology, University of Auckland, Auckland 1023, New Zealand; (R.G.); (N.M.); (J.M.D.); (S.K.D.); (K.Y.); (C.A.L.); (G.W.); (J.O.D.); (V.J.K.); (L.B.)
| | - Simerdeep K. Dhillon
- Department of Physiology, University of Auckland, Auckland 1023, New Zealand; (R.G.); (N.M.); (J.M.D.); (S.K.D.); (K.Y.); (C.A.L.); (G.W.); (J.O.D.); (V.J.K.); (L.B.)
| | - Kyohei Yamaguchi
- Department of Physiology, University of Auckland, Auckland 1023, New Zealand; (R.G.); (N.M.); (J.M.D.); (S.K.D.); (K.Y.); (C.A.L.); (G.W.); (J.O.D.); (V.J.K.); (L.B.)
| | - Christopher A. Lear
- Department of Physiology, University of Auckland, Auckland 1023, New Zealand; (R.G.); (N.M.); (J.M.D.); (S.K.D.); (K.Y.); (C.A.L.); (G.W.); (J.O.D.); (V.J.K.); (L.B.)
| | - Guido Wassink
- Department of Physiology, University of Auckland, Auckland 1023, New Zealand; (R.G.); (N.M.); (J.M.D.); (S.K.D.); (K.Y.); (C.A.L.); (G.W.); (J.O.D.); (V.J.K.); (L.B.)
| | - Joanne O. Davidson
- Department of Physiology, University of Auckland, Auckland 1023, New Zealand; (R.G.); (N.M.); (J.M.D.); (S.K.D.); (K.Y.); (C.A.L.); (G.W.); (J.O.D.); (V.J.K.); (L.B.)
| | - Fraser Nott
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria 3168, Australia; (F.N.); (V.A.Z.); (S.B.K.)
| | - Valerie A. Zahra
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria 3168, Australia; (F.N.); (V.A.Z.); (S.B.K.)
| | - Sharmony B. Kelly
- The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, Victoria 3168, Australia; (F.N.); (V.A.Z.); (S.B.K.)
- Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria 3800, Australia
| | - Victoria J. King
- Department of Physiology, University of Auckland, Auckland 1023, New Zealand; (R.G.); (N.M.); (J.M.D.); (S.K.D.); (K.Y.); (C.A.L.); (G.W.); (J.O.D.); (V.J.K.); (L.B.)
| | - Stéphane V. Sizonenko
- Division of Child Development & Growth, Department of Pediatrics, Gynaecology & Obstetrics, School of Medicine, University of Geneva, 1015 Geneva, Switzerland; (Y.v.d.L.); (S.V.S.)
| | - Laura Bennet
- Department of Physiology, University of Auckland, Auckland 1023, New Zealand; (R.G.); (N.M.); (J.M.D.); (S.K.D.); (K.Y.); (C.A.L.); (G.W.); (J.O.D.); (V.J.K.); (L.B.)
| | - Alistair J. Gunn
- Department of Physiology, University of Auckland, Auckland 1023, New Zealand; (R.G.); (N.M.); (J.M.D.); (S.K.D.); (K.Y.); (C.A.L.); (G.W.); (J.O.D.); (V.J.K.); (L.B.)
- Correspondence:
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Lear CA, Davidson JO, Dhillon SK, King VJ, Lear BA, Magawa S, Maeda Y, Ikeda T, Gunn AJ, Bennet L. Effects of antenatal dexamethasone and hyperglycemia on cardiovascular adaptation to asphyxia in preterm fetal sheep. Am J Physiol Regul Integr Comp Physiol 2020; 319:R653-R665. [PMID: 33074015 DOI: 10.1152/ajpregu.00216.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Antenatal glucocorticoids improve outcomes among premature infants but are associated with hyperglycemia, which can exacerbate hypoxic-ischemic injury. It is still unclear how antenatal glucocorticoids or hyperglycemia modulate fetal cardiovascular adaptations to severe asphyxia. In this study, preterm fetal sheep received either saline or 12 mg im maternal dexamethasone, followed 4 h later by complete umbilical cord occlusion (UCO) for 25 min. An additional cohort of fetuses received titrated glucose infusions followed 4 h later by UCO to control for the possibility that hyperglycemia contributed to the cardiovascular effects of dexamethasone. Fetuses were studied for 7 days after UCO. Maternal dexamethasone was associated with fetal hyperglycemia (P < 0.001), increased arterial pressure (P < 0.001), and reduced femoral (P < 0.005) and carotid (P < 0.05) vascular conductance before UCO. UCO was associated with bradycardia, femoral vasoconstriction, and transient hypertension. For the first 5 min of UCO, fetal blood pressure in the dexamethasone-asphyxia group was greater than saline-asphyxia (P < 0.001). However, the relative increase in arterial pressure was not different from saline-asphyxia. Fetal heart rate and femoral vascular conductance fell to similar nadirs in both saline and dexamethasone-asphyxia groups. Dexamethasone did not affect the progressive decline in femoral vascular tone or arterial pressure during continuing UCO. By contrast, there were no effects of glucose infusions on the response to UCO. In summary, maternal dexamethasone but not fetal hyperglycemia increased fetal arterial pressure before and for the first 5 min of prolonged UCO but did not augment the cardiovascular adaptations to acute asphyxia.
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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
| | - Joanne O Davidson
- 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
| | - Victoria J King
- 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
| | - Shoichi Magawa
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand.,Department of Obstetrics and Gynecology, Mie University, Mie, Japan
| | - Yoshiki Maeda
- The Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand.,Department of Obstetrics and Gynecology, Mie University, Mie, Japan
| | - Tomoaki Ikeda
- Department of Obstetrics and Gynecology, Mie University, Mie, Japan
| | - 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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Nussbaumer-Streit B, Klerings I, Dobrescu AI, Persad E, Stevens A, Garritty C, Kamel C, Affengruber L, King VJ, Gartlehner G. Excluding non-English publications from evidence-syntheses did not change conclusions: a meta-epidemiological study. J Clin Epidemiol 2019; 118:42-54. [PMID: 31698064 DOI: 10.1016/j.jclinepi.2019.10.011] [Citation(s) in RCA: 139] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 10/24/2019] [Accepted: 10/31/2019] [Indexed: 01/05/2023]
Abstract
OBJECTIVES We aimed to assess whether limiting the inclusion criteria solely to English-language publications affected the overall conclusions of evidence syntheses. STUDY DESIGN AND SETTING Our analyses used a dataset of a previous methods study that included 59 randomly selected Cochrane intervention reviews with no language restrictions. First, we ascertained the publication language of all 2,026 included publications. Next, we excluded studies based on the following criteria: (1) publication solely in non-English language, or (2) main publication (in case of multiple publications of the same study) in non-English language. We then re-calculated meta-analyses for outcomes that were presented in the main summary of findings tables of the Cochrane reports. If the direction of the effect estimate or the statistical significance changed, authors of the respective Cochrane reviews were consulted to assess whether the new evidence base would have changed their conclusions. The primary outcome of our analyses examined the proportion of conclusions that would change with the exclusion of non-English publications. We set the threshold for the approach as noninferior if the upper limit of the 95% confidence interval of the proportion of changed conclusions did not cross a margin of 10%. RESULTS Across all 59 Cochrane reviews, 29 (49%) included 80 non-English publications. For 16 (27%) of these Cochrane reviews, the exclusion of non-English publications resulted in the exclusion of at least one study. In the remaining 13 Cochrane reviews, the non-English publications were not the only or main publication of the study or they did not contribute to the main summary of the findings table, so their exclusion did not result in an exclusion of the study. Overall, the exclusion of non-English publications led to the exclusion of 31 studies contributing to 40 outcomes. For 38 of the 40 outcomes, the exclusion of non-English studies did not markedly alter the size or direction of effect estimates or statistical significance. In two outcomes, the statistical significance changed, but authors would have still drawn the same conclusion, albeit with less certainty. Thus, the proportion of changed conclusions in our sample was 0.0% (95% CI 0.0-0.6), which indicated the noninferiority of the approach. However, the majority of excluded studies were small. CONCLUSION Exclusion of non-English publications from systematic reviews on clinical interventions had a minimal effect on overall conclusions and could be a viable methodological shortcut, especially for rapid reviews.
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Affiliation(s)
- B Nussbaumer-Streit
- Cochrane Austria, Department for Evidence-based Medicine and Evaluation, Danube University Krems, Krems a.d. Donau, Austria.
| | - I Klerings
- Cochrane Austria, Department for Evidence-based Medicine and Evaluation, Danube University Krems, Krems a.d. Donau, Austria
| | - A I Dobrescu
- Cochrane Austria, Department for Evidence-based Medicine and Evaluation, Danube University Krems, Krems a.d. Donau, Austria
| | - E Persad
- Cochrane Austria, Department for Evidence-based Medicine and Evaluation, Danube University Krems, Krems a.d. Donau, Austria
| | - A Stevens
- Knowledge Synthesis Group, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Canada
| | - C Garritty
- Knowledge Synthesis Group, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Canada
| | - C Kamel
- HTA and Rapid Response, Canadian Agency for Drugs and Technologies in Health (CADTH), Ottawa, Canada
| | - L Affengruber
- Cochrane Austria, Department for Evidence-based Medicine and Evaluation, Danube University Krems, Krems a.d. Donau, Austria; Department of Family Medicine, Care and Public Health Research Institute (CAPHRI), Maastricht University, The Netherlands
| | - V J King
- The Center for Evidence-based Policy, Oregon Health & Science University, Portland, Oregon, United States
| | - G Gartlehner
- Cochrane Austria, Department for Evidence-based Medicine and Evaluation, Danube University Krems, Krems a.d. Donau, Austria; RTI International, Research Triangle Park, NC, USA
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Abstract
BACKGROUND Rates of labour induction are increasing. OBJECTIVES To review the evidence supporting indications for induction. SEARCH STRATEGY We listed indications for labour induction and then reviewed the evidence. We searched MEDLINE and the Cochrane Library between 1980 and April 2008 using several terms and combinations, including induction of labour, premature rupture of membranes, post-term pregnancy, preterm prelabour rupture of membranes (PROM), multiple gestation, suspected macrosomia, diabetes, gestational diabetes mellitus, cardiac disease, fetal anomalies, systemic lupus erythematosis, oligohydramnios, alloimmunization, rhesus disease, intrahepatic cholestasis of pregnancy (IHCP), and intrauterine growth restriction (IUGR). We performed a review of the literature supporting each indication. SELECTION CRITERIA We identified 1387 abstracts and reviewed 418 full text articles. We preferentially included high-quality systematic reviews or large randomised trials. Where no such studies existed, we included the best evidence available from smaller randomised trials and observational studies. MAIN RESULTS We included 34 full text articles. For each indication, we assigned levels of evidence and grades of recommendation based upon the GRADE system. Recommendations for induction of labour for post-term gestation, PROM at term, and premature rupture of membranes near term with pulmonary maturity are supported by the evidence. Induction for IUGR before term reduces intrauterine fetal death, but increases caesarean deliveries and neonatal deaths. Evidence is insufficient to support induction for women with insulin-requiring diabetes, twin gestation, fetal macrosomia, oligohydramnios, cholestasis of pregnancy, maternal cardiac disease and fetal gastroschisis. AUTHORS' CONCLUSIONS Research is needed to determine risks and benefits of induction for many commonly advocated clinical indications.
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Affiliation(s)
- E Mozurkewich
- Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, USA.
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Viswanathan M, King VJ, Bordley C, Honeycutt AA, Wittenborn J, Jackman AM, Sutton SF, Lohr KN. Management of bronchiolitis in infants and children. Evid Rep Technol Assess (Summ) 2003:1-5. [PMID: 12624885 PMCID: PMC4781009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
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11
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Davidson LL, Grisso JA, Garcia-Moreno C, Garcia J, King VJ, Marchant S. Training programs for healthcare professionals in domestic violence. J Womens Health Gend Based Med 2001; 10:953-69. [PMID: 11788106 DOI: 10.1089/152460901317193530] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Although women who experience domestic violence seek healthcare services frequently, screening and counseling rates remain low, and healthcare professionals report feeling inadequately trained to care for abused women. The English language literature from 1989 to 1999 was searched to identify and evaluate published assessments of the education of healthcare providers in domestic violence toward women. Major deficiencies in program evaluation were found. They included the use of a historical comparison group, lack of an experimental design, selection of nonstandardized outcomes without clinical performance measures, short-term follow-up, limited documentation of course content and theory, and lack of focus on the impact of programs on abused women. Educational programs generally consisted of a single session of limited duration (1-3 hours). Based on published reports, it appears that few rigorously designed evaluations have been conducted of training programs for healthcare providers in the detection and treatment of women affected by domestic violence.
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Affiliation(s)
- L L Davidson
- National Perinatal Epidemiology Unit, Institute of Health Sciences, University of Oxford, Oxford, England
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Denham AC, King VJ. Does episiotomy increase perineal laceration length in primiparous women? J Fam Pract 2001; 50:1018. [PMID: 11742596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- A C Denham
- Department of Family Medicine, University of North Carolina at Chapel Hill, USA.
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Sanghavi SN, Miranpuri SS, Chappell R, Buatti JM, Sneed PK, Suh JH, Regine WF, Weltman E, King VJ, Goetsch SJ, Breneman JC, Sperduto PW, Scott C, Mabanta S, Mehta MP. Radiosurgery for patients with brain metastases: a multi-institutional analysis, stratified by the RTOG recursive partitioning analysis method. Int J Radiat Oncol Biol Phys 2001; 51:426-34. [PMID: 11567817 DOI: 10.1016/s0360-3016(01)01622-4] [Citation(s) in RCA: 213] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE To estimate the potential improvement in survival for patients with brain metastases, stratified by the Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis (RPA) class and treated with radiosurgery (RS) plus whole brain radiotherapy (WBRT). METHODS AND MATERIALS An analysis of the RS databases of 10 institutions identified patients with brain metastates treated with RS and WBRT. Patients were stratified into 1 of 3 RPA classes. Survival was evaluated using Kaplan-Meier estimates and proportional hazard regression analysis. A comparison of survival by class was carried out with the RTOG results in similar patients receiving WBRT alone. RESULTS Five hundred two patients were eligible (261 men and 241 women, median age 59 years, range 26-83). The overall median survival was 10.7 months. A higher Karnofsky performance status (p = 0.0001), a controlled primary (median survival = 11.6 vs. 8.8 months, p = 0.0023), absence of extracranial metastases (median survival 13.4 vs. 9.1 months, p = 0.0001), and lower RPA class (median survival 16.1 months for class I vs. 10.3 months for class II vs. 8.7 months for class III, p = 0.000007) predicted for improved survival. Gender, age, primary site, radiosurgery technique, and institution were not prognostic. The addition of RS boosted results in median survival (16.1, 10.3, and 8.7 months for classes I, II, and III, respectively) compared with the median survival (7.1, 4.2, and 2.3 months, p <0.05) observed in the RTOG RPA analysis for patients treated with WBRT alone. CONCLUSION In the absence of randomized data, these results suggest that RS may improve survival in patients with BM. The improvement in survival does not appear to be restricted by class for well-selected patients.
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Hartmann KE, King VJ. Elective induction of labour: complicating the uncomplicated? Paediatr Perinat Epidemiol 2001; 15:138-9. [PMID: 11383578 DOI: 10.1046/j.1365-3016.2001.00338.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- K E Hartmann
- Department of Obstetrics and Gynecology, University of North Carolina School of Medicine, Chapel Hill 27599-7400, USA.
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15
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King VJ. Is the sweeping of membranes a useful intervention in conjunction with induction of labor in term pregnancy? J Fam Pract 2001; 50:65. [PMID: 11195484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- V J King
- The University of North Carolina, Chapel Hill, USA.
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King VJ. Is test-and-eradicate or prompt endoscopy more effective for treatment of dyspepsia in Helicobacter pylori-positive patients? J Fam Pract 2000; 49:1048. [PMID: 11093572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- V J King
- University of North Carolina, Chapel Hill, USA.
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17
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King VJ. PPIs vs H2RAs for erosive reflux esophagitis. J Fam Pract 1998; 46:199-200. [PMID: 9519012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- V J King
- University of North Carolina, Chapel Hill, USA.
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18
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Abstract
Certified nurse-midwives and family physicians share a philosophy of family-centered maternity care. Collaboration between the two disciplines, however, has not been common. Collaboration can enhance the primary care and maternity care options available to clients of such collaborative practices. Advantages and barriers to collaboration for both types of practitioners, as well as suggestions for successful collaboration, are discussed.
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Affiliation(s)
- P A Payne
- Department of Family Medicine, Chapel Hill, NC 27599-7595, USA
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King VJ. OC failure rates and oral antibiotics. J Fam Pract 1997; 45:104-105. [PMID: 9267366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- V J King
- Department of Family Medicine, University of North Carolina at Chapel Hill, USA.
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20
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King VJ. Routine obstetric ultrasonography. J Fam Pract 1996; 43:235-239. [PMID: 8797748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- V J King
- University of North Carolina Chapel Hill, USA.
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King VJ. Membrane stripping to promote labor. J Fam Pract 1996; 43:119-123. [PMID: 8708617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- V J King
- University of North Carolina at Chapel Hill, USA.
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King VJ. Passion and compassion. The healing arts. N C Med J 1992; 53:177. [PMID: 1594060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- V J King
- University of North Carolina School of Medicine, Chapel Hill
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Abstract
Cultured bovine aortic endothelial cells migrate toward a concentration gradient of repeating elastin peptides, specifically the repeating nonamers Gly-Phe-Gly-Val-Gly-Ala-Gly-Val-Pro and Gly-Leu-Gly-Val-Gly-Ala-Gly-Val-Pro and the repeating hexamer Val-Gly-Val-Ala-Pro-Gly. Dose-response experiments demonstrate that the peak of activity occurs at 8 x 10(-8) M for the nonapeptides and 1 x 10(-8) M for the hexapeptide. Checkerboard assays establish that the movement is chemotaxis and not chemokinesis. Because of the concentration difference in the responsiveness between the nonapeptide and the hexapeptide, the cells can differentiate between the two types of repeats. The positive control for the chemotaxis studies was fibronectin.
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Affiliation(s)
- M M Long
- Department of Anesthesiology, School of Medicine, University of Alabama, Birmingham 35294
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Lynch DH, Haddad S, King VJ, Ott MJ, Straight RC, Jolles CJ. Systemic immunosuppression induced by photodynamic therapy (PDT) is adoptively transferred by macrophages. Photochem Photobiol 1989; 49:453-8. [PMID: 2727085 DOI: 10.1111/j.1751-1097.1989.tb09194.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Some derivatives of hematoporphyrins are strongly retained by tumor tissue as compared to normal tissue, and exposure of these photosensitizers to radiation in the visible spectrum can cause serious biological damage. These properties have been exploited in the development of a new treatment for cancer termed photodynamic therapy (PDT). However, recent studies have also demonstrated that PDT can also induce a state of systemic immunosuppression. The purpose of this study was to determine whether PDT-induced suppression of contact hypersensitivity (CHS) responses was an active phenomenon that could be adoptively transferred by viable splenocytes from PDT-treated mice. Although induction of adoptively transferable suppressor cells in PDT-treated mice required exposure to antigen, the suppressor cells were found to be antigen nonspecific in their function. Furthermore, splenocytes from PDT-treated mice were capable of generating levels of allospecific cytotoxic T lymphocyte (CTL) activity which were comparable to those generated by normal control mice, but the ability of irradiated spleen cells from PDT-treated mice to stimulate a mixed lymphocyte response (MLR) was dramatically impaired. Finally, chromatographic separation of T cells, B cells and macrophages showed that the cell type which mediates adoptively transferable suppression of CHS responsiveness is in the macrophage lineage.
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Abstract
Bovine ligamentum fibroblasts, which produce elastin, migrate towards a positive chemical gradient of human platelet-derived growth factor and of the tropoelastin repeat hexapeptide Val-Gly-Val-Ala-Pro-Gly, as previously shown. They are also responsive to two permutations of a nonapeptide that repeats in tropoelastin, i.e., Ala-Gly-Val-Pro-Gly-Phe-Gly-Val-Gly and Gly-Phe-Gly-Val-Gly-Ala-Gly-Val-Pro. Concentration curves and checkerboard assays prove that the nonapeptides are chemoattractants. The component pentapeptide, Gly-Phe-Gly-Val-Gly, is chemotactic, while the component tetrapeptide Ala-Gly-Val-Pro is not. The hexapeptide competitively suppresses the nonapeptide chemotaxis suggesting the involvement of a common cell receptor. The results support the concept that elastin has multiple cell recognition sites as measured by the chemotactic response and that among the hydrophobic repeating sequences of elastin chemotacticity is selectively and multiply localized.
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Affiliation(s)
- M M Long
- Laboratory of Molecular Biophysics, University of Alabama at Birmingham 35294
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Long MM, King VJ, Prasad KU, Urry DW. Cell attachment and chemotaxis can utilize the same peptide sequence of fibronectin. Biochim Biophys Acta 1987; 928:114-8. [PMID: 3828400 DOI: 10.1016/0167-4889(87)90092-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Fibronectin and fragments of the parent molecule are involved in cell-substrate attachment, cell migration and chemotaxis. The cell attachment sequence, Gly-Arg-Gly-Asp-Ser-Pro, was synthesized and tested for its ability to effect ligamentum nuchae fibroblast chemotaxis. This hexapeptide and fibronectin itself both caused directed cell migration, with maximal activity in the 10(-10) to 10(-9) M range. These data demonstrate that the fibronectin cell binding site and chemotaxis site share a common sequence.
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