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Nawaytou H, Hills NK, Clyman RI. Patent ductus arteriosus and the risk of bronchopulmonary dysplasia-associated pulmonary hypertension. Pediatr Res 2023; 94:547-554. [PMID: 36804505 PMCID: PMC10403370 DOI: 10.1038/s41390-023-02522-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 01/13/2023] [Indexed: 02/19/2023]
Abstract
BACKGROUND The aim of the study was to determine whether prolonged exposure to a moderate/large patent ductus arteriosus left-to-right shunt (PDA) increases the risk of late (beyond 36 weeks) pulmonary hypertension (BPD-PH) and pulmonary vascular disease (BPD-PVD) during the neonatal hospitalization in preterm infants (<28 weeks' gestation) with bronchopulmonary dysplasia (BPD). METHODS All infants requiring respiratory support ≥36 weeks had systematic echocardiographic evaluations for BPD-PH at planned intervals. Infants were classified as having either flow-associated BPD-PH (BPD-flow-PH) or BPD-PVD. RESULTS 256 infants survived ≥36 weeks: 105 had NO BPD (were off respiratory support by 36 weeks); 151 had BPD. 22/151 had BPD-PH (12/22 had BPD-flow-PH from a PDA that persisted beyond 36 weeks; 10/22 had BPD-PVD). Moderate/large PDA shunts that persisted beyond 36 weeks were significantly associated with an increased incidence of BPD-PH due to BPD-flow-PH. We found no association between the duration of PDA exposure and the incidence of BPD-PVD. CONCLUSIONS Moderate/large PDA shunts increase the risk of flow-associated BPD-PH when present beyond 36 weeks. Although term infants with PDA-congenital heart disease can develop pulmonary vascular remodeling and PVD after months of PDA exposure, we found no echocardiographic evidence in preterm infants that prolonged PDA exposure increases the incidence of BPD-PVD during the neonatal hospitalization. IMPACT In our study, preterm infants (<28 weeks' gestation) with bronchopulmonary dysplasia (BPD) had a 15% incidence of pulmonary hypertension (PH) beyond 36 weeks' postmenstrual age as a comorbidity. Moderate/large patent ductus arteriosus (PDA) shunts increased the risk of flow-associated PH when present beyond 36 weeks. Although months of prolonged PDA exposure can cause pulmonary vascular remodeling and pulmonary vascular disease (PVD) in term infants with PDA-congenital heart disease, we found no echocardiographic evidence for an association between the duration of PDA exposure and the incidence of late PVD during the neonatal hospitalization in preterm infants with BPD.
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Affiliation(s)
- Hythem Nawaytou
- Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA
| | - Nancy K Hills
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA
- Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - Ronald I Clyman
- Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA.
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA.
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2
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Fike CD, Aschner JL. Pharmacotherapy for Pulmonary Hypertension in Infants with Bronchopulmonary Dysplasia: Past, Present, and Future. Pharmaceuticals (Basel) 2023; 16:503. [PMID: 37111262 PMCID: PMC10141152 DOI: 10.3390/ph16040503] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/07/2023] [Accepted: 03/09/2023] [Indexed: 03/31/2023] Open
Abstract
Approximately 8-42% of premature infants with chronic lung disease of prematurity, bronchopulmonary dysplasia (BPD), develop pulmonary hypertension (PH). Infants with BPD-PH carry alarmingly high mortality rates of up to 47%. Effective PH-targeted pharmacotherapies are desperately needed for these infants. Although many PH-targeted pharmacotherapies are commonly used to treat BPD-PH, all current use is off-label. Moreover, all current recommendations for the use of any PH-targeted therapy in infants with BPD-PH are based on expert opinion and consensus statements. Randomized Control Trials (RCTs) are needed to determine the efficacy of PH-targeted treatments in premature infants with or at risk of BPD-PH. Prior to performing efficacy RCTs, studies need to be conducted to obtain pharmacokinetic, pharmacodynamic, and safety data for any pharmacotherapy used in this understudied and fragile patient population. This review will discuss current and needed treatment strategies, identify knowledge deficits, and delineate both challenges to be overcome and approaches to be taken to develop effective PH-targeted pharmacotherapies that will improve outcomes for premature infants with or at risk of developing BPD-PH.
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Affiliation(s)
- Candice D. Fike
- Department of Pediatrics, University of Utah Health, Salt Lake City, UT 84108, USA
| | - Judy L. Aschner
- Department of Pediatrics, Joseph M. Sanzari Children’s Hospital at Hackensack University Medical Center, Hackensack, NJ 07601, USA
- Department of Pediatrics, Hackensack Meridian School of Medicine, Nutley, NJ 07110, USA
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3
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Fukasawa Y, Yamamoto H, Ito M, Saito A, Go K, Morimoto Y, Yasuda K, Sato Y, Hayakawa M, Kato T. Case report: High-dose epoprostenol therapy in pediatric patients with pulmonary hypertension and developmental lung disease. Front Pediatr 2023; 11:1116434. [PMID: 36937960 PMCID: PMC10020523 DOI: 10.3389/fped.2023.1116434] [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] [Received: 12/05/2022] [Accepted: 02/13/2023] [Indexed: 03/06/2023] Open
Abstract
Pulmonary hypertension (PH) with developmental lung disease is a life-threatening disease and accounts for 10%-12% of pediatric PH patients. Administration of specific pulmonary vasodilators to pediatric PH patients has brought about improvement of their long-term prognosis. Intravenous epoprostenol therapy is a gold standard therapy for severe idiopathic pulmonary arterial hypertension (IPAH), but there are few reports demonstrating the efficacy of epoprostenol for pediatric PH patients with developmental lung disease, especially when treating with high doses of epoprostenol. Two cases of pediatric PH patients with alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) and congenital diaphragmatic hernia (CDH) with bronchopulmonary dysplasia (BPD), respectively, treated with epoprostenol above 100 ng/kg/min are presented. In these two cases, severe PH was improved significantly by an aggressive increase of the epoprostenol infusion rate with administration of oral pulmonary vasodilators and appropriate respiratory management, without any significant adverse effects. High-dose epoprostenol therapy may be one of the therapeutic options in pediatric PH patients with developmental lung disease.
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Affiliation(s)
- Yoshie Fukasawa
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hidenori Yamamoto
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Miharu Ito
- Division of Neonatology, Center for Maternal-Neonatal Care, Nagoya University Hospital, Nagoya, Japan
- Second Department of Pediatrics, Ogaki Municipal Hospital, Ogaki, Japan
| | - Akiko Saito
- Division of Neonatology, Center for Maternal-Neonatal Care, Nagoya University Hospital, Nagoya, Japan
- Department of Pediatrics, Japanese Red Cross Aichi Medical Center Nagoya Daiichi Hospital, Nagoya, Japan
| | - Kiyotaka Go
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoshihito Morimoto
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Kazushi Yasuda
- Department of Pediatrics, Japanese Red Cross Aichi Medical Center Nagoya Daiichi Hospital, Nagoya, Japan
| | - Yoshiaki Sato
- Division of Neonatology, Center for Maternal-Neonatal Care, Nagoya University Hospital, Nagoya, Japan
| | - Masahiro Hayakawa
- Division of Neonatology, Center for Maternal-Neonatal Care, Nagoya University Hospital, Nagoya, Japan
| | - Taichi Kato
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Correspondence: Taichi Kato
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Elders BBLJ, Tiddens HAWM, Pijnenburg MWH, Reiss IKM, Wielopolski PA, Ciet P. Lung structure and function on MRI in preterm born school children with and without BPD: A feasibility study. Pediatr Pulmonol 2022; 57:2981-2991. [PMID: 35982507 PMCID: PMC9826116 DOI: 10.1002/ppul.26119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 07/05/2022] [Accepted: 07/11/2022] [Indexed: 01/11/2023]
Abstract
BACKGROUND AND OBJECTIVE The most common respiratory complication of prematurity is bronchopulmonary dysplasia (BPD), leading to structural lung changes and impaired respiratory outcomes. However, also preterm children without BPD may show similar adverse respiratory outcomes. There is a need for a safe imaging modality for preterm children with and without BPD for disease severity assessment and risk stratification. Our objective was to develop a magnetic resonance imaging (MRI) protocol in preterm children with and without BPD at school age. METHODS Nine healthy volunteers (median age 11.6 [range: 8.8-12.8] years), 11 preterm children with BPD (11.0 [7.2-15.6] years), and 9 without BPD (11.1 [10.7-12.6] years) underwent MRI. Images were scored on hypo- and hyperintense abnormalities, bronchopathy, and architectural distortion. MRI data were correlated to spirometry. Ventilation and perfusion defects were analyzed using Fourier Decomposition (FD) MRI. RESULTS On MRI, children with BPD had higher %diseased lung (9.1 (interquartile range [IQR] 5.9-11.6)%) compared to preterm children without BPD (3.4 (IQR 2.5-5.4)%, p < 0.001) and healthy volunteers (0.4 (IQR 0.1-0.8)%, p < 0.001). %Diseased lung correlated negatively with %predicted FEV1 (r = -0.40, p = 0.04), FEV1 /FVC (r = -0.49, p = 0.009) and FEF75 (r = -0.63, p < 0.001). Ventilation and perfusion defects on FD sequence corresponded to hypointense regions on expiratory MRI. CONCLUSION Chest MRI can identify structural and functional lung damage at school age in preterm children with and without BPD, showing a good correlation with spirometry. We propose MRI as a sensitive and safe imaging method (without ionizing radiation, contrast agents, or the use of anesthesia) for the long-term follow-up of preterm children.
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Affiliation(s)
- Bernadette B L J Elders
- Department of Paediatric Pulmonology and Allergology, Erasmus MC-Sophia Children's Hospital, University Medical Centre Rotterdam, Rotterdam, The Netherlands.,Department of Radiology and Nuclear Medicine, Erasmus MC-Sophia Children's Hospital, University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Harm A W M Tiddens
- Department of Paediatric Pulmonology and Allergology, Erasmus MC-Sophia Children's Hospital, University Medical Centre Rotterdam, Rotterdam, The Netherlands.,Department of Radiology and Nuclear Medicine, Erasmus MC-Sophia Children's Hospital, University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Mariëlle W H Pijnenburg
- Department of Paediatric Pulmonology and Allergology, Erasmus MC-Sophia Children's Hospital, University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Irwin K M Reiss
- Department of Neonatology, Erasmus MC-Sophia Children's Hospital, University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Piotr A Wielopolski
- Department of Radiology and Nuclear Medicine, Erasmus MC-Sophia Children's Hospital, University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Pierluigi Ciet
- Department of Paediatric Pulmonology and Allergology, Erasmus MC-Sophia Children's Hospital, University Medical Centre Rotterdam, Rotterdam, The Netherlands.,Department of Radiology and Nuclear Medicine, Erasmus MC-Sophia Children's Hospital, University Medical Centre Rotterdam, Rotterdam, The Netherlands
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5
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Duke JW, Lewandowski AJ, Abman SH, Lovering AT. Physiological aspects of cardiopulmonary dysanapsis on exercise in adults born preterm. J Physiol 2022; 600:463-482. [PMID: 34961925 PMCID: PMC9036864 DOI: 10.1113/jp281848] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 12/03/2021] [Indexed: 02/03/2023] Open
Abstract
Progressive improvements in perinatal care and respiratory management of preterm infants have resulted in increased survival of newborns of extremely low gestational age over the past few decades. However, the incidence of bronchopulmonary dysplasia, the chronic lung disease after preterm birth, has not changed. Studies of the long-term follow-up of adults born preterm have shown persistent abnormalities of respiratory, cardiovascular and cardiopulmonary function, possibly leading to a lower exercise capacity. The underlying causes of these abnormalities are incompletely known, but we hypothesize that dysanapsis, i.e. discordant growth and development, in the respiratory and cardiovascular systems is a central structural feature that leads to a lower exercise capacity in young adults born preterm than those born at term. We discuss how the hypothesized system dysanapsis underscores the observed respiratory, cardiovascular and cardiopulmonary limitations. Specifically, adults born preterm have: (1) normal lung volumes but smaller airways, which causes expiratory airflow limitation and abnormal respiratory mechanics but without impacts on pulmonary gas exchange efficiency; (2) normal total cardiac size but smaller cardiac chambers; and (3) in some cases, evidence of pulmonary hypertension, particularly during exercise, suggesting a reduced pulmonary vascular capacity despite reduced cardiac output. We speculate that these underlying developmental abnormalities may accelerate the normal age-associated decline in exercise capacity, via an accelerated decline in respiratory, cardiovascular and cardiopulmonary function. Finally, we suggest areas of future research, especially the need for longitudinal and interventional studies from infancy into adulthood to better understand how preterm birth alters exercise capacity across the lifespan.
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Affiliation(s)
- Joseph W. Duke
- Northern Arizona University, Department of Biological Sciences, Flagstaff, AZ, USA
| | - Adam J. Lewandowski
- University of Oxford, Oxford Cardiovascular Clinical Research Facility, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, Oxford, UK
| | - Steven H. Abman
- University of Colorado Anschutz School of Medicine, Department of Pediatrics, Aurora, CO, USA
- Pediatric Heart Lung Center, Children’s Hospital Colorado, Aurora, CO, USA
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Ruschkowski BA, Esmaeil Y, Daniel K, Gaudet C, Yeganeh B, Grynspan D, Jankov RP. Thrombospondin-1 Plays a Major Pathogenic Role in Experimental and Human Bronchopulmonary Dysplasia. Am J Respir Crit Care Med 2022; 205:685-699. [PMID: 35021035 DOI: 10.1164/rccm.202104-1021oc] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Extremely preterm infants develop bronchopulmonary dysplasia (BPD), a chronic lung injury that lacks effective treatment. Thrombospondin-1 is an anti-angiogenic protein that activates TGF-β1, a cytokine strongly linked to both experimental and human BPD. OBJECTIVES 1) To examine effects of inhibiting thrombospondin-1-mediated TGF-β1 activation (LSKL) in neonatal rats with bleomycin-induced lung injury, 2) To examine effects of a thrombospondin-1-mimic (ABT-510) on lung morphology, and 3) To determine whether thrombospondin-1 and related signaling peptides are increased in lungs of human preterm infants at risk for BPD. METHODS From postnatal days 1-14, rat pups received daily i.p. bleomycin (1 mg/kg) or vehicle combined with daily s.c. LSKL (20 mg/kg) or vehicle. Separate animals were treated with vehicle or ABT-510 (30 mg/kg/d). Paraffin-embedded lung tissues from 47 autopsies (controls; death <28 days, n=30 and BPD at risk; death ≥28 days, n=17) performed on infants born <29 completed weeks' gestation were semi-quantified for injury markers (collagen, macrophages, 3-nitrotyrosine), thrombospondin-1 and TGF-β1. MEASUREMENTS AND MAIN RESULTS Bleomycin or ABT-510 increased lung TGF-β1 activity and macrophage influx, caused pulmonary hypertension and led to alveolar and microvascular hypoplasia. Treatment with LSKL partially prevented abnormal lung morphology secondary to bleomycin. Lungs from human infants at-risk for BPD had increased contents of thrombospondin-1 and TGF-β1 when compared to controls. TGF-β1 content correlated with markers of lung injury. CONCLUSIONS Thrombospondin-1 inhibits alveologenesis in neonatal rats, in part via up-regulated activity of TGF-β1. Observations in human lung suggest a similar pathogenic role for thrombospondin-1 in infants at-risk for BPD.
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Affiliation(s)
- Brittany Ann Ruschkowski
- Children's Hospital of Eastern Ontario Research Institute, 274065, Molecular Biomedicine, Ottawa, Ontario, Canada
| | - Yousef Esmaeil
- University of Ottawa, Paediatrics, Ottawa, Ontario, Canada
| | - Kate Daniel
- Children's Hospital of Eastern Ontario Research Institute, 274065, Molecular Biomedicine, Ottawa, Ontario, Canada
| | - Chantal Gaudet
- Children's Hospital of Eastern Ontario Research Institute, 274065, Molecular Biomedicine, Ottawa, Ontario, Canada
| | - Behzad Yeganeh
- Children's Hospital of Eastern Ontario Research Institute, 274065, Molecular Biomedicine, Ottawa, Ontario, Canada
| | - David Grynspan
- University of Ottawa, Paediatrics, Ottawa, Ontario, Canada
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7
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Thomas L, Baczynski M, Deshpande P, Kharrat A, Joye S, Zhu F, Ibarra-Rios D, Shah PS, Mertens L, Jankov RP, Ye XY, Neary E, Ting J, Castaldo M, Levy P, Smith A, El-Khuffash AF, Giesinger RE, McNamara PJ, Weisz DE, Jain A. Multicentre prospective observational study exploring the predictive value of functional echocardiographic indices for early identification of preterm neonates at risk of developing chronic pulmonary hypertension secondary to chronic neonatal lung disease. BMJ Open 2021; 11:e044924. [PMID: 33789855 PMCID: PMC8016080 DOI: 10.1136/bmjopen-2020-044924] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
INTRODUCTION Although chronic pulmonary hypertension (cPH) secondary to chronic neonatal lung disease is associated with increased mortality and respiratory and neurodevelopmental morbidities, late diagnosis (typically ≥36 weeks postmenstrual age, PMA) and the use of qualitative echocardiographic diagnostic criterion (flat interventricular septum in systole) remain significant limitations in clinical care. Our objective in this study is to evaluate the utility of relevant quantitative echocardiographic indices to identify cPH in preterm neonates, early in postnatal course and to develop a diagnostic test based on the best combination of markers. METHODS AND ANALYSIS In this ongoing international prospective multicentre observational diagnostic accuracy study, we aim to recruit 350 neonates born <27 weeks PMA and/or birth weight <1000 g and perform echocardiograms in the third week of age and at 32 weeks PMA (early diagnostic assessments, EDA) in addition to the standard diagnostic assessment (SDA) for cPH at 36 weeks PMA. Predefined echocardiographic markers under investigation will be measured at each EDA and examined to create a scoring system to identify neonates who subsequently meet the primary outcome of cPH/death at SDA. Diagnostic test characteristics will be defined for each EDA. Pulmonary artery acceleration time and tricuspid annular plane systolic excursion are the primary markers of interest. ETHICS AND DISSEMINATION Ethics approval has been received by the Mount Sinai Hospital Research Ethics Board (REB) (#16-0111-E), Sunnybrook Health Sciences Centre REB (#228-2016), NHS Health Research Authority (IRAS 266498), University of Iowa Human Subjects Office/Institutional Review Board (201903736), Rotunda Hospital Research and Ethics Committee (REC-2019-008), and UBC Children's and Women's REB (H19-02738), and is under review at Boston Children's Hospital Institutional Review Board. Study results will be disseminated to participating families in lay format, presented to the scientific community at paediatric and critical care conferences and published in relevant peer-reviewed journals. TRAIL REGISTRATION NUMBER NCT04402645.
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Affiliation(s)
- Laura Thomas
- Paediatrics, Sinai Health System, Toronto, Ontario, Canada
- Newborn and Developmental Paediatrics, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | | | - Poorva Deshpande
- Paediatrics, Sinai Health System, Toronto, Ontario, Canada
- Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Ashraf Kharrat
- Paediatrics, Sinai Health System, Toronto, Ontario, Canada
- Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Sébastien Joye
- Clinic of Neonatology, Lausanne University Hospital, Lausanne, Switzerland
| | - Faith Zhu
- Paediatrics, Sinai Health System, Toronto, Ontario, Canada
| | - Daniel Ibarra-Rios
- Neonatology, Hospital Infantil de Mexico Federico Gomez, Mexico City, Mexico
| | - Prakesh S Shah
- Paediatrics, Sinai Health System, Toronto, Ontario, Canada
- Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Luc Mertens
- Division of Cardiology, Department of Paediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Robert P Jankov
- Division of Neonatology, Department of Paediatrics, University of Ottawa, Ottawa, Ontario, Canada
| | - Xiang Y Ye
- MiCare Research Centre, Sinai Health System, Toronto, Ontario, Canada
| | - Elaine Neary
- Neonatology, Liverpool Women's Hospital NHS Foundation Trust, Liverpool, UK
| | - Joseph Ting
- Neonatology, The University of British Columbia, Vancouver, Ontario, Canada
| | - Michael Castaldo
- Neonatology, The University of British Columbia, Vancouver, Ontario, Canada
| | - Philip Levy
- Boston Children's Hospital Department of Pediatrics, Boston, Massachusetts, USA
- Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | | | | | - Regan E Giesinger
- Pediatrics, The University of Iowa Stead Family Children's Hospital, Iowa City, Iowa, USA
| | - Patrick J McNamara
- Pediatrics, The University of Iowa Stead Family Children's Hospital, Iowa City, Iowa, USA
| | - Dany E Weisz
- Newborn and Developmental Paediatrics, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
- Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Amish Jain
- Paediatrics, Sinai Health System, Toronto, Ontario, Canada
- Paediatrics, University of Toronto, Toronto, Ontario, Canada
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Duke JW, Lovering AT. Respiratory and cardiopulmonary limitations to aerobic exercise capacity in adults born preterm. J Appl Physiol (1985) 2020; 129:718-724. [PMID: 32790592 DOI: 10.1152/japplphysiol.00419.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Adults born preterm, regardless of whether they develop bronchopulmonary dysplasia, have underdeveloped respiratory and cardiopulmonary systems. The resulting impaired respiratory and cardiopulmonary systems are inadequate for the challenges imposed by aerobic exercise, which is exacerbated by the presence of bronchopulmonary dysplasia. Thus the respiratory and cardiopulmonary systems of these preterm individuals may be the most influential contributors to the significantly lower aerobic exercise capacity compared with their term born counterparts. The precise underlying cause(s) of the lower aerobic exercise capacity in adults born preterm is not entirely known but could be a number of interrelated parameters including mechanical ventilatory constraints, impaired pulmonary gas exchange efficiency, and excessive cardiopulmonary pressures. Likewise, additional aspects, such as impaired cardiovascular function and altered muscle bioenergetics, may play additional roles in limiting aerobic exercise capacity. Whether or not all or some of these aspects are present in adults born preterm and precisely how they may contribute to the lower aerobic exercise capacity are only beginning to be systematically explored. The purpose of this mini-review is to outline what is currently known about the respiratory and cardiopulmonary limitations during exercise in this population and to identify key areas where additional knowledge will help to advance this area. Additionally, where possible, we highlight the similarities and differences between obstructive lung disease resulting from preterm birth and chronic obstructive pulmonary disease (COPD) as the physiology and pathophysiology of these two forms of obstructive lung disease may not be identical.
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Affiliation(s)
- Joseph W Duke
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona
| | - Andrew T Lovering
- Department of Human Physiology, University of Oregon, Eugene, Oregon
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Abstract
Home oxygen therapy is increasingly prescribed for various conditions in the neonatal period, particularly for infants with bronchopulmonary dysplasia. Due to limited evidence on indication, minimal target oxygen saturation, monitoring, application and discontinuation of home oxygen therapy clinical practice varies widely throughout the world. International guidelines provide recommendations mostly on the basis of nonsystematic clinical observations. Most relevant points for the clinical management of home oxygen therapy include a minimal target oxygen saturation of equal to or greater than 93%, the provision of a home monitoring of oxygen saturation ideally with a memory function, and the conduct of continuous overnight oximetry or polysomnography during weaning from supplemental oxygen. This review summarizes relevant literature as well as existing guidelines and recommendations on home oxygen therapy to aid clinicians in the management of these patients and identifies areas for future research.
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Affiliation(s)
- Sabine Pirr
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, 30625 Hannover, Germany.
| | - Corinna Peter
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, 30625 Hannover, Germany.
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10
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Mesenchymal stem/stromal cells stably transduced with an inhibitor of CC chemokine ligand 2 ameliorate bronchopulmonary dysplasia and pulmonary hypertension. Cytotherapy 2020; 22:180-192. [PMID: 32139242 DOI: 10.1016/j.jcyt.2020.01.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 01/21/2020] [Accepted: 01/22/2020] [Indexed: 12/20/2022]
Abstract
Perinatal bronchopulmonary dysplasia (BPD) is defined as lung injury in preterm infants caused by various factors, resulting in serious respiratory dysfunction and high mortality. The administration of mesenchymal stem/stromal cells (MSCs) to treat/prevent BPD has proven to have certain therapeutic effects. However, MSCs can only weakly regulate macrophage function, which is strongly involved in the development of BPD. 7ND-MSCs are MSCs transfected with 7ND, a truncated version of CC chemokine ligand 2 (CCL2) that promotes macrophage activation, using a lentiviral vector. In the present study, we show in a BPD rat model that 7ND-MSC administration, but not MSCs alone, ameliorated the impaired alveolarization evaluated by volume density and surface area in the lung tissue, as well as pulmonary artery remodeling and pulmonary hypertension induced by BPD. In addition, 7ND-MSCs, but not MSCs alone, reduced M1 macrophages and the messenger RNA expressions of interleukin-6 and CCL2 in the lung tissue. Thus, the present study showed the treatment effect of 7ND-MSCs in a BPD rat model, which was more effective than that of MSCs alone.
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11
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Ligon RA, Vaiyani D, Deshpande S. Right ventricular myocardial performance index in pediatric patients with bronchopulmonary dysplasia-related pulmonary hypertension. Echocardiography 2019; 36:1353-1356. [PMID: 31184776 DOI: 10.1111/echo.14392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 04/24/2019] [Accepted: 05/14/2019] [Indexed: 01/27/2023] Open
Abstract
INTRODUCTION This study aims to assess the utility of right ventricular myocardial performance index (RVMPI) as a potential echocardiographic tool to evaluate and serially follow patients with bronchopulmonary dysplasia (BPD) and pulmonary hypertension (PH). METHODS We performed a retrospective chart review of all hemodynamic cardiac catheterizations performed January 2011 to December 2016 in patients born premature and with diagnosed BPD up to 4 years of age-excluding patients with significant congenital heart defects. Echocardiograms performed within 24 hours of the cardiac catheterization were reviewed, and a blinded RVMPI was calculated. The primary endpoint was correlation of invasive catheterization hemodynamics to noninvasive echocardiographic RVMPI measurement. RESULTS A total of 49 individual patients met complete study criteria, and 10 of those patients underwent repeat cardiac catheterization. Median age at the time of assessment was 8 months (25%-75%, 4-18 months), and the cohort had a calculated RVMPI mean of 0.39 (±0.19), with 73% (43/59) having a RVMPI >0.28. A statistically significant correlation was found between the RVMPI and the baseline hemodynamics during catheterization with regard to the initial mean pulmonary arterial pressure (r = 0.58; P < 0.01) as well as the calculated pulmonary vascular resistance (r = 0.34; P = 0.01). CONCLUSIONS This study demonstrates the utility of RVMPI for evaluation of PH in patients with prematurity and BPD. An increased RVMPI by noninvasive echocardiography was found to correlate with increased mean pulmonary arterial pressure and pulmonary vascular resistance measured during invasive cardiac catheterization. Large-scale validation of this study is being planned.
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Affiliation(s)
- R Allen Ligon
- Children's Healthcare of Atlanta, Sibley Heart Center Cardiology, Emory University, Atlanta, Georgia
| | - Danish Vaiyani
- Children's Healthcare of Atlanta, Sibley Heart Center Cardiology, Emory University, Atlanta, Georgia
| | - Shriprasad Deshpande
- Children's National Heart Institute, Children's National Health System, Washington, District of Columbia
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Laliberté C, Hanna Y, Ben Fadel N, Lemyre B, Bijelic V, Barrowman N, Hoey L, Thébaud B, Katz SL. Target oxygen saturation and development of pulmonary hypertension and increased pulmonary vascular resistance in preterm infants. Pediatr Pulmonol 2019; 54:73-81. [PMID: 30461218 DOI: 10.1002/ppul.24193] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 10/12/2018] [Indexed: 01/12/2023]
Abstract
OBJECTIVE Determine whether higher targeted oxygen levels are associated with reduced incidence of pulmonary hypertension (PH) and elevated pulmonary vascular resistance (PVR) in extremely premature infants. STUDY DESIGN Retrospective chart review of 252 extremely preterm infants (<29 weeks), who underwent echocardiogram prior to discharge. PH rates were compared during periods (June 2012-May 2015 and June 2015-April 2016) when lower (88-92%) or higher (90-95%) oxygen saturation targets were used. PH was determined on echocardiography. The ratio of pulmonary artery acceleration time to right ventricular ejection time was computed, with values <0.31 indicative of elevated PVR. Survival analysis compared the effects of oxygen saturation group on development/resolution of PH and elevated PVR. RESULTS The higher saturation group had significantly lower risk of developing PH (hazard ratio (HR) = 0.50, 95%CI 0.26-0.95; P = 0.03) or elevated PVR (HR = 0.55, 95%CI 0.38-0.81; P = 0.002), compared to the lower oxygen saturation group. Median time to PH development was significantly shorter in the lower saturation group than in the higher saturation group (5 days vs 12 days; P = 0.02), as was time to development of elevated PVR (4 days vs 6 days; P < 0.001). Duration of PH (P = 0.12) and elevated PVR (P = 0.86) did not differ significantly between groups. Cumulative incidence of PH (P = 0.04) and elevated PVR (P = 0.01) at 36 weeks post-menstrual age was significantly lower in the high saturation group compared to the lower saturation group. CONCLUSION Higher targeted oxygen saturation was associated with reduced risk of PH or elevated PVR in extremely preterm infants compared to lower oxygen saturation target.
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Affiliation(s)
| | - Youstina Hanna
- Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Nadya Ben Fadel
- Children's Hospital of Eastern Ontario, Department of Pediatrics, Ottawa, Ontario, Canada
| | - Brigitte Lemyre
- Children's Hospital of Eastern Ontario, Department of Pediatrics, Ottawa, Ontario, Canada
| | - Vid Bijelic
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - Nicholas Barrowman
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - Lynda Hoey
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - Bernard Thébaud
- Children's Hospital of Eastern Ontario, Department of Pediatrics, Ottawa, Ontario, Canada
| | - Sherri L Katz
- Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.,Children's Hospital of Eastern Ontario, Department of Pediatrics, Ottawa, Ontario, Canada.,Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
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13
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Modepalli V, Kumar A, Sharp JA, Saunders NR, Nicholas KR, Lefèvre C. Gene expression profiling of postnatal lung development in the marsupial gray short-tailed opossum (Monodelphis domestica) highlights conserved developmental pathways and specific characteristics during lung organogenesis. BMC Genomics 2018; 19:732. [PMID: 30290757 PMCID: PMC6173930 DOI: 10.1186/s12864-018-5102-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 09/21/2018] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND After a short gestation, marsupials give birth to immature neonates with lungs that are not fully developed and in early life the neonate partially relies on gas exchange through the skin. Therefore, significant lung development occurs after birth in marsupials in contrast to eutherian mammals such as humans and mice where lung development occurs predominantly in the embryo. To explore the mechanisms of marsupial lung development in comparison to eutherians, morphological and gene expression analysis were conducted in the gray short-tailed opossum (Monodelphis domestica). RESULTS Postnatal lung development of Monodelphis involves three key stages of development: (i) transition from late canalicular to early saccular stages, (ii) saccular and (iii) alveolar stages, similar to developmental stages overlapping the embryonic and perinatal period in eutherians. Differentially expressed genes were identified and correlated with developmental stages. Functional categories included growth factors, extracellular matrix protein (ECMs), transcriptional factors and signalling pathways related to branching morphogenesis, alveologenesis and vascularisation. Comparison with published data on mice highlighted the conserved importance of extracellular matrix remodelling and signalling pathways such as Wnt, Notch, IGF, TGFβ, retinoic acid and angiopoietin. The comparison also revealed changes in the mammalian gene expression program associated with the initiation of alveologenesis and birth, pointing to subtle differences between the non-functional embryonic lung of the eutherian mouse and the partially functional developing lung of the marsupial Monodelphis neonates. The data also highlighted a subset of contractile proteins specifically expressed in Monodelphis during and after alveologenesis. CONCLUSION The results provide insights into marsupial lung development and support the potential of the marsupial model of postnatal development towards better understanding of the evolution of the mammalian bronchioalveolar lung.
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Affiliation(s)
| | - Amit Kumar
- Peter MacCallum Cancer Centre, Melbourne, Australia
| | - Julie A Sharp
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Australia.,Institute of Frontiers Materials, Deakin University, Pigdons Road, Geelong, VIC, Australia
| | - Norman R Saunders
- Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, Australia
| | - Kevin R Nicholas
- School of Medicine, Deakin University, Pigdons Road, Geelong, VIC, Australia.,Department of Anatomy and Developmental Biology, Monash University, Clayton, Australia.,Monash Institute of Pharmaceutical Science, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Christophe Lefèvre
- School of Medicine, Deakin University, Pigdons Road, Geelong, VIC, Australia. .,Division of Bioinformatics, Walter and Eliza Hall Medical Research Institute, Melbourne, Australia. .,Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, Australia. .,Peter MacCallum Cancer Centre, Melbourne, Australia.
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14
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Mühlfeld C, Wrede C, Knudsen L, Buchacker T, Ochs M, Grothausmann R. Recent developments in 3-D reconstruction and stereology to study the pulmonary vasculature. Am J Physiol Lung Cell Mol Physiol 2018; 315:L173-L183. [DOI: 10.1152/ajplung.00541.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Alterations of the pulmonary vasculature are an important feature of human lung diseases such as chronic obstructive pulmonary disease, pulmonary hypertension, and bronchopulmonary dysplasia. Experimental studies to investigate the pathogenesis or a therapeutic intervention in animal models of these diseases often require robust, meaningful, and efficient morphometric data that allow for appropriate statistical testing. The gold standard for obtaining such data is design-based stereology. However, certain morphological characteristics of the pulmonary vasculature make the implementation of stereological methods challenging. For example, the alveolar capillary network functions according to the sheet flow principle, thus making unbiased length estimations impossible and requiring other strategies to obtain mechanistic morphometric data. Another example is the location of pathological changes along the branches of the vascular tree. For developmental defects like in bronchopulmonary dysplasia or for pulmonary hypertension, it is important to know whether certain segments of the vascular tree are preferentially altered. This cannot be overcome by traditional stereological methods but requires the combination of a three-dimensional data set and stereology. The present review aims at highlighting the great potential while discussing the major challenges (such as time consumption and data volume) of this combined approach. We hope to raise interest in the potential of this approach and thus stimulate solutions to overcome the existing challenges.
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Affiliation(s)
- Christian Mühlfeld
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
| | - Christoph Wrede
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
| | - Lars Knudsen
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
| | - Tobias Buchacker
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Matthias Ochs
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
| | - Roman Grothausmann
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Cluster of Excellence REBIRTH (From Regenerative Biology to Reconstructive Therapy), Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany
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15
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Duke JW, Gladstone IM, Sheel AW, Lovering AT. Premature birth affects the degree of airway dysanapsis and mechanical ventilatory constraints. Exp Physiol 2017; 103:261-275. [PMID: 29193495 DOI: 10.1113/ep086588] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 11/10/2017] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Adult survivors of preterm birth without (PRE) and with bronchopulmonary dysplasia (BPD) have airflow obstruction at rest and significant mechanical ventilatory constraints during exercise compared with those born at full term (CON). Do PRE/BPD have smaller airways, indexed via the dysanapsis ratio, than CON? What is the main finding and its importance? The dysanapsis ratio was significantly smaller in BPD and PRE compared with CON, with BPD having the smallest dysanapsis ratio. These data suggest that airflow obstruction in PRE and BPD might be because of smaller airways than CON. Adult survivors of very preterm birth (≤32 weeks gestational age) without (PRE) and with bronchopulmonary dysplasia (BPD) have obstructive lung disease as evidenced by reduced expiratory airflow at rest and have significant mechanical ventilatory constraints during exercise. Airflow obstruction, in any conditions, could be attributable to several factors, including small airways. PRE and/or BPD could have smaller airways than their counterparts born at full term (CON) owing to a greater degree of dysanaptic airway development during the pre- and/or postnatal period. Thus, the purpose of the present study was to compare the dysanapsis ratio (DR), as an index of airway size, between PRE, BPD and CON. To do so, we calculated DR in PRE (n = 21), BPD (n = 14) and CON (n = 34) individuals and examined flow-volume loops at rest and during submaximal exercise. The DR, using multiple estimates of static recoil pressure, was significantly smaller in PRE and BPD (0.16 ± 0.05 and 0.10 ± 0.03 a.u.) compared with CON (0.22 ± 0.04 a.u.; both P < 0.001) and smallest in BPD (P < 0.001). The DR was significantly correlated with peak expiratory airflow at rest (r = 0.42; P < 0.001) and the extent of expiratory flow limitation during exercise (r = 0.60; P < 0.001). Our findings suggest that PRE/BPD might have anatomically smaller airways than CON, which might help to explain their lower expiratory airflow rate at rest and during exercise and further our understanding of the consequences of preterm birth and neonatal O2 therapy.
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Affiliation(s)
- Joseph W Duke
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Igor M Gladstone
- Department of Paediatrics, Oregon Health and Sciences University, Portland, OR, USA
| | - A William Sheel
- School of Kinesiology, University of British Columbia, Vancouver, BC, Canada
| | - Andrew T Lovering
- Department of Human Physiology, University of Oregon, Eugene, OR, USA
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16
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Alvira CM, Morty RE. Can We Understand the Pathobiology of Bronchopulmonary Dysplasia? J Pediatr 2017; 190:27-37. [PMID: 29144252 PMCID: PMC5726414 DOI: 10.1016/j.jpeds.2017.08.041] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 07/28/2017] [Accepted: 08/16/2017] [Indexed: 01/17/2023]
Affiliation(s)
- Cristina M. Alvira
- Center for Excellence in Pulmonary Biology, Department of Pediatrics, Stanford University School of Medicine, Palo Alto, California 94305
| | - Rory E. Morty
- Department of Internal Medicine (Pulmonology), University of Giessen and Marburg Lung Center campus of the German Center for Lung Research, Giessen, Germany,Department of Lung Development and Remodelling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
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17
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Lapcharoensap W, Kan P, Powers RJ, Shaw GM, Stevenson DK, Gould JB, Wirtschafter DD, Lee HC. The Relationship of Nosocomial Infection Reduction to Changes in Neonatal Intensive Care Unit Rates of Bronchopulmonary Dysplasia. J Pediatr 2017; 180:105-109.e1. [PMID: 27742123 DOI: 10.1016/j.jpeds.2016.09.030] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 08/09/2016] [Accepted: 09/09/2016] [Indexed: 01/07/2023]
Abstract
OBJECTIVE To examine whether recent reductions in rates of nosocomial infection have contributed to changes in rates of bronchopulmonary dysplasia (BPD) in a population-based cohort. STUDY DESIGN This was a retrospective, population-based cohort study that used the California Perinatal Quality Care Collaborative database from 2006 to 2013. Eligible infants included those less than 30 weeks' gestational age and less than 1500 g who survived to 3 days of life. Primary variables of interest were rates of nosocomial infections and BPD. Adjusted rates of nosocomial infections and BPD from a baseline period (2006-2010) were compared with a later period (2011-2013). The correlation of changes in rates across periods for both variables was assessed by hospital of care. RESULTS A total of 22 967 infants from 129 hospitals were included in the study. From the first to second time period, the incidence of nosocomial infections declined from 24.7% to 15% and BPD declined from 35% to 30%. Adjusted hospital rates of BPD and nosocomial infections were correlated positively with a calculated 8% reduction of BPD rates attributable to reductions in nosocomial infections. CONCLUSIONS Successful interventions to reduce rates of nosocomial infections may have a positive impact on other comorbidities such as BPD. The prevention of nosocomial infections should be viewed as a significant component in avoiding long-term neonatal morbidities.
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Affiliation(s)
- Wannasiri Lapcharoensap
- Department of Pediatrics, Oregon Health & Science University, Portland, OR; California Perinatal Quality Care Collaborative, Stanford, CA.
| | - Peiyi Kan
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA; March of Dimes Prematurity Research Center, Stanford, CA
| | | | - Gary M Shaw
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA; March of Dimes Prematurity Research Center, Stanford, CA
| | - David K Stevenson
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA; March of Dimes Prematurity Research Center, Stanford, CA
| | - Jeffrey B Gould
- California Perinatal Quality Care Collaborative, Stanford, CA; Department of Pediatrics, Stanford University School of Medicine, Stanford, CA; March of Dimes Prematurity Research Center, Stanford, CA
| | | | - Henry C Lee
- California Perinatal Quality Care Collaborative, Stanford, CA; Department of Pediatrics, Stanford University School of Medicine, Stanford, CA; March of Dimes Prematurity Research Center, Stanford, CA
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18
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Ee MT, Kantores C, Ivanovska J, Wong MJ, Jain A, Jankov RP. Leukotriene B4 mediates macrophage influx and pulmonary hypertension in bleomycin-induced chronic neonatal lung injury. Am J Physiol Lung Cell Mol Physiol 2016; 311:L292-302. [PMID: 27317685 DOI: 10.1152/ajplung.00120.2016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 06/13/2016] [Indexed: 11/22/2022] Open
Abstract
Systemically-administered bleomycin causes inflammation, arrested lung growth, and pulmonary hypertension (PHT) in the neonatal rat, similar to human infants with severe bronchopulmonary dysplasia (BPD). Leukotrienes (LTs) are inflammatory lipid mediators produced by multiple cell types in the lung. The major LTs, LTB4 and cysteinyl LTs, are suggested to contribute to BPD, but their specific roles remain largely unexplored in experimental models. We hypothesized that LTs are increased in bleomycin-induced BPD-like injury, and that inhibition of LT production would prevent inflammatory cell influx and thereby ameliorate lung injury. Rat pups were exposed to bleomycin (1 mg·kg(-1)·day(-1) ip) or vehicle (control) from postnatal days 1-14 and were treated with either zileuton (5-lipoxygenase inhibitor), montelukast (cysteinyl LT1 receptor antagonist), or SC57461A (LTA4 hydrolase inhibitor) 10 mg·kg(-1)·day(-1) ip. Bleomycin led to increased lung content of LTB4, but not cysteinyl LTs. Bleomycin-induced increases in tissue neutrophils and macrophages and lung contents of LTB4 and tumor necrosis factor-α were all prevented by treatment with zileuton. Treatment with zileuton or SC57461A also prevented the hemodynamic and structural markers of chronic PHT, including raised pulmonary vascular resistance, increased Fulton index, and arterial wall remodeling. However, neither treatment prevented impaired alveolarization or vascular hypoplasia secondary to bleomycin. Treatment with montelukast had no effect on macrophage influx, PHT, or on abnormal lung structure. We conclude that LTB4 plays a crucial role in lung inflammation and PHT in experimental BPD. Agents targeting LTB4 or LTB4-mediated signaling may have utility in infants at risk of developing BPD-associated PHT.
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Affiliation(s)
- Mong Tieng Ee
- Program in Physiology and Experimental Medicine, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada; Division of Neonatology, Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Crystal Kantores
- Program in Physiology and Experimental Medicine, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Julijana Ivanovska
- Program in Physiology and Experimental Medicine, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Mathew J Wong
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Amish Jain
- Division of Neonatology, Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada; Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Robert P Jankov
- Program in Physiology and Experimental Medicine, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada; Division of Neonatology, Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada; Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Heart and Stroke Richard Lewar Centre of Excellence in Cardiovascular Research, University of Toronto, Toronto, Ontario, Canada; and
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19
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Alvira CM. Aberrant Pulmonary Vascular Growth and Remodeling in Bronchopulmonary Dysplasia. Front Med (Lausanne) 2016; 3:21. [PMID: 27243014 PMCID: PMC4873491 DOI: 10.3389/fmed.2016.00021] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 04/28/2016] [Indexed: 01/12/2023] Open
Abstract
In contrast to many other organs, a significant portion of lung development occurs after birth during alveolarization, thus rendering the lung highly susceptible to injuries that may disrupt this developmental process. Premature birth heightens this susceptibility, with many premature infants developing the chronic lung disease, bronchopulmonary dysplasia (BPD), a disease characterized by arrested alveolarization. Over the past decade, tremendous progress has been made in the elucidation of mechanisms that promote postnatal lung development, including extensive data suggesting that impaired pulmonary angiogenesis contributes to the pathogenesis of BPD. Moreover, in addition to impaired vascular growth, patients with BPD also frequently demonstrate alterations in pulmonary vascular remodeling and tone, increasing the risk for persistent hypoxemia and the development of pulmonary hypertension. In this review, an overview of normal lung development will be presented, and the pathologic features of arrested development observed in BPD will be described, with a specific emphasis on the pulmonary vascular abnormalities. Key pathways that promote normal pulmonary vascular development will be reviewed, and the experimental and clinical evidence demonstrating alterations of these essential pathways in BPD summarized.
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Affiliation(s)
- Cristina M Alvira
- Department of Pediatrics, Division of Critical Care Medicine, Stanford University School of Medicine , Stanford, CA , USA
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20
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Duke JW, Elliott JE, Laurie SS, Beasley KM, Mangum TS, Hawn JA, Gladstone IM, Lovering AT. Pulmonary gas exchange efficiency during exercise breathing normoxic and hypoxic gas in adults born very preterm with low diffusion capacity. J Appl Physiol (1985) 2014; 117:473-81. [DOI: 10.1152/japplphysiol.00307.2014] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Adults with a history of very preterm birth (<32 wk gestational age; PRET) have reduced lung function and significantly lower lung diffusion capacity for carbon monoxide (DLCO) relative to individuals born at term (CONT). Low DLCO may predispose PRET to diffusion limitation during exercise, particularly while breathing hypoxic gas because of a reduced O2 driving gradient and pulmonary capillary transit time. We hypothesized that PRET would have significantly worse pulmonary gas exchange efficiency [i.e., increased alveolar-to-arterial Po2 difference (AaDO2)] during exercise breathing room air or hypoxic gas (FiO2 = 0.12) compared with CONT. To test this hypothesis, we compared the AaDO2 in PRET ( n = 13) with a clinically mild reduction in DLCO (72 ± 7% of predicted) and CONT ( n = 14) with normal DLCO (105 ± 10% of predicted) pre- and during exercise breathing room air and hypoxic gas. Measurements of temperature-corrected arterial blood gases, and direct measure of O2 saturation (SaO2), were made prior to and during exercise at 25, 50, and 75% of peak oxygen consumption (V̇o2peak) while breathing room air and hypoxic gas. In addition to DLCO, pulmonary function and exercise capacity were significantly less in PRET. Despite PRET having low DLCO, no differences were observed in the AaDO2 or SaO2 pre- or during exercise breathing room air or hypoxic gas compared with CONT. Although our findings were unexpected, we conclude that reduced pulmonary function and low DLCO resulting from very preterm birth does not cause a measureable reduction in pulmonary gas exchange efficiency.
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Affiliation(s)
- Joseph W. Duke
- Department of Human Physiology, University of Oregon, Eugene, Oregon
| | | | - Steven S. Laurie
- Department of Human Physiology, University of Oregon, Eugene, Oregon
| | - Kara M. Beasley
- Department of Human Physiology, University of Oregon, Eugene, Oregon
| | - Tyler S. Mangum
- Department of Human Physiology, University of Oregon, Eugene, Oregon
| | - Jerold A. Hawn
- Oregon Heart and Vascular Institute, Springfield, Oregon; and
| | - Igor M. Gladstone
- Department of Pediatrics, Oregon Health and Science University, Portland, Oregon
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21
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Al Dabbagh M, Banjar H, Galal N, Kouatli A, Kandil H, Chehab M. Saudi Guidelines on the Diagnosis and Treatment of Pulmonary Hypertension: Pulmonary hypertension in children. Ann Thorac Med 2014; 9:S113-20. [PMID: 25076989 PMCID: PMC4114278 DOI: 10.4103/1817-1737.134053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Accepted: 04/05/2014] [Indexed: 11/04/2022] Open
Abstract
Pulmonary hypertension (PH) is relatively uncommon in children. Pulmonary arterial hypertension (PAH) in pediatric comprises a wide spectrum of diseases, from a transient neonatal condition to a progressive disease associated with morbidity and mortality. Most common PAH in pediatric are idiopathic (IPAH) or PAH associated with congenital heart disease (PAH-CHD), while other associated conditions, such as connective tissue disease (CTD), are less common in pediatrics. Despite better understanding of PH and the availability of new medications during recent decades; the diagnosis, investigation and choice of therapy remain a challenge in children, as evidence-based recommendations depend mainly on adult studies. In this review, we provide a detailed discussion about the distinctive features of PAH in pediatric, mainly emphacysing on classification and diagnostic algorithm.
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Affiliation(s)
- Maha Al Dabbagh
- Department of Pediatric, King Fahd Armed Forces Hospital, Jeddah, Saudi Arabia
| | - Hanna Banjar
- Department of Pediatric, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nasser Galal
- Department of Pediatric Cardiology, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia
| | - Amjad Kouatli
- Department of Pediatric Cardiology, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia
| | - Hammam Kandil
- Department of Pediatric Cardiology, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia
| | - May Chehab
- Pediatric Intensive Care, Prince Sultan Medical Military City, Riyadh, Saudi Arabia
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22
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Lee AH, Dhaliwal R, Kantores C, Ivanovska J, Gosal K, McNamara PJ, Letarte M, Jankov RP. Rho-kinase inhibitor prevents bleomycin-induced injury in neonatal rats independent of effects on lung inflammation. Am J Respir Cell Mol Biol 2014; 50:61-73. [PMID: 23947621 DOI: 10.1165/rcmb.2013-0131oc] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Bleomycin-induced lung injury is characterized in the neonatal rat by inflammation dominated by neutrophils and macrophages, inhibited distal airway and vascular development, and pulmonary hypertension, similar to human infants with severe bronchopulmonary dysplasia. Rho-kinase (ROCK) is known to mediate lung injury in adult animals via stimulatory effects on inflammation. We therefore hypothesized that inhibition of ROCK may ameliorate bleomycin-induced lung injury in the neonatal rat. Pups received daily intraperitoneal bleomycin or saline from Postnatal Days 1 through 14 with or without Y-27632, a ROCK inhibitor. Treatment with Y-27632 prevented bleomycin-induced pulmonary hypertension, as evidenced by normalized pulmonary vascular resistance, decreased right-ventricular hypertrophy, and attenuated remodeling of pulmonary resistance arteries. Bleomycin-induced changes in distal lung architecture, including septal thinning, inhibited alveolarization, and decreased numbers of peripheral arteries and capillaries, were partially or completely normalized by Y-27632. Treatment with Y-27632 or a CXCR2 antagonist, SB265610, also abrogated tissue neutrophil influx, while having no effect on macrophages. However, treatment with SB265610 did not prevent bleomycin-induced lung injury. Lung content of angiostatic thrombospondin-1 (TSP1) was increased significantly in the lungs of bleomycin-exposed animals, and was completely attenuated by treatment with Y-27632. Thrombin-stimulated TSP1 production by primary cultured rat pulmonary artery endothelial cells was also attenuated by Y-27632. Taken together, our findings suggest a preventive effect of Y-27632 on bleomycin-mediated injury by a mechanism unrelated to inflammatory cells. Our data suggest that improvements in lung morphology may have been related to indirect stimulatory effects on angiogenesis via down-regulation of TSP1.
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23
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Manzano RM, Mascaretti RS, Carrer V, Haddad LB, Fernandes AR, Reyes AMA, Rebello CM. A hyperoxic lung injury model in premature rabbits: the influence of different gestational ages and oxygen concentrations. PLoS One 2014; 9:e95844. [PMID: 24755658 PMCID: PMC3995887 DOI: 10.1371/journal.pone.0095844] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 03/31/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Many animal models have been developed to study bronchopulmonary dysplasia (BPD). The preterm rabbit is a low-cost, easy-to-handle model, but it has a high mortality rate in response to the high oxygen concentrations used to induce lung injury. The aim of this study was to compare the mortality rates of two models of hyperoxia-induced lung injury in preterm rabbits. METHODS Pregnant New Zealand white rabbits were subjected to caesarean section on gestational day 28 or 29 (full term = 31 days). The premature rabbits in the 28-day gestation group were exposed to room air or FiO₂ ≥95%, and the rabbits in the 29-day gestation group were exposed to room air or FiO₂ = 80% for 11 days. The mean linear intercept (Lm), internal surface area (ISA), number of alveoli, septal thickness and proportion of elastic and collagen fibers were quantified. RESULTS The survival rates in the 29-day groups were improved compared with the 28-day groups. Hyperoxia impaired the normal development of the lung, as demonstrated by an increase in the Lm, the septal thickness and the proportion of elastic fibers. Hyperoxia also decreased the ISA, the number of alveoli and the proportion of collagen fibers in the 28-day oxygen-exposed group compared with the control 28-day group. A reduced number of alveoli was found in the 29-day oxygen exposed animals compared with the control 29-day group. CONCLUSIONS The 29-day preterm rabbits had a reduced mortality rate compared with the 28-day preterm rabbits and maintained a reduction in the alveoli number, which is comparable to BPD in humans.
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Affiliation(s)
| | | | - Valéria Carrer
- Albert Einstein Jewish Hospital, São Paulo, São Paulo, Brazil
| | | | | | | | - Celso Moura Rebello
- Albert Einstein Jewish Hospital, São Paulo, São Paulo, Brazil
- School of Medicine - Clinics Hospital University of Sao Paulo, São Paulo, São Paulo, Brazil
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Waruingi W, Mhanna MJ. Pulmonary hypertension in extremely low birth weight infants: characteristics and outcomes. World J Pediatr 2014; 10:46-52. [PMID: 24464663 DOI: 10.1007/s12519-014-0464-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 03/05/2013] [Indexed: 11/30/2022]
Abstract
BACKGROUND To determine the characteristics and outcomes of pulmonary arterial hypertension (PAH) in extremely low birth weight (ELBW) infants. METHODS A retrospective case-control study of all ELBW infants admitted to a level III neonatal intensive care unit (NICU) between January 1, 2003 and December 31, 2010. RESULTS During the study period, 450 ELBW infants were admitted. 6.4% (29/450) were diagnosed with PAH and were matched to 26 controls. The mean gestational age of infants with PAH and their controls were similar [24.5 ± 1.3 vs. 24.9 ± 1.8 weeks (P=0.26)]; however the cases were smaller at birth than were controls [640.7 ± 119.5 vs. 727.0 ± 184.5 g (P=0.04)]. The diagnosis of PAH was made at a mean postnatal age of 131.8 ± 53.7 days. Infants with PAH had a higher rate of intrauterine exposure to illicit maternal drug use [12/29 (41%) vs. 1/25 (4%); P=0.001], a longer duration of initial mechanical ventilation [74.9 ± 28.3 vs. 59.1 ± 27.8 days; P=0.04)], a higher incidence of severe BPD [23/29 (79%) vs. 13/26 (50%); P=0.02], and a greater NICU mortality rate [12/29 (41%) vs. 4/26 (15%); P=0.04]. CONCLUSION PAH in ELBW infants is associated with maternal illicit drug use in pregnancy, longer exposure to mechanical ventilation, severe bronchopulmonary dysplasia and a significant increase in early mortality.
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Affiliation(s)
- Wambui Waruingi
- Department of Pediatrics, Division of Neonatology, Metro Health Medical Center, Case Western Reserve University School of Medicine, Cleveland, OH, 44109, USA
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25
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Kim DH, Kim HS. Serial changes of serum endostatin and angiopoietin-1 levels in preterm infants with severe bronchopulmonary dysplasia and subsequent pulmonary artery hypertension. Neonatology 2014; 106:55-61. [PMID: 24818792 DOI: 10.1159/000358374] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 01/07/2014] [Indexed: 11/19/2022]
Abstract
BACKGROUND In bronchopulmonary dysplasia (BPD), disrupted angiogenesis may result from an imbalance between pro- and anti-angiogenic factors triggered by inflammation, leading to the late development of pulmonary artery hypertension (PAH). OBJECTIVES To investigate whether the levels of serum endostatin (as an anti-angiogenic factor) and angiopoietin-1 (AP-1; as a pro-angiogenic factor) in early life are associated with the development of PAH in preterm infants with severe BPD. METHODS In this prospective cohort study, the levels of serum endostatin and AP-1 were measured from 56 infants (gestational age <30 weeks or birth weight <1,250 g) including severe BPD with PAH ('PAH'; 15 infants) or without PAH ('non-PAH'; 22 infants) and no/mild BPD (19 infants) groups on days 1, 7, 14, and 28 of life. RESULTS The PAH group consistently underwent more aggressive respiratory management than the non-PAH group, over 1 month after birth. The endostatin level and the ratio of endostatin to AP-1 on day 7 of life were significantly higher in the PAH group than in the non-PAH group or no/mild BPD groups (median 146.6 vs. 102.4/108.0 ng/ml; 62.1 vs. 18.6/14.9). The ratio of endostatin to AP-1 on day 1 was also significantly higher in the PAH group than in the no/mild BPD group (median 31.8 vs. 11.3). CONCLUSIONS An increased serum endostatin to AP-1 ratio may reflect impaired angiogenesis that may lead to the development of PAH [corrected].
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Affiliation(s)
- Do-Hyun Kim
- Department of Pediatrics, Dongguk University Ilsan Hospital, Goyang, Korea
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26
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Poon CY, Edwards MO, Kotecha S. Long term cardiovascular consequences of chronic lung disease of prematurity. Paediatr Respir Rev 2013; 14:242-9. [PMID: 24209460 DOI: 10.1016/j.prrv.2012.08.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Pulmonary arterial (PA) hypertension in preterm infant is an important consequence of chronic lung disease of prematurity (CLD) arising mainly due to impaired alveolar development and dysregulated angiogenesis of the pulmonary circulation. Although PA pressure and resistance in these children normalise by school age, their pulmonary vasculature remains hyper-reactive to hypoxia until early childhood. Furthermore, there is evidence that systemic blood pressure in preterm born children with or without CLD is mildly increased at school age and in young adulthood when compared to term-born children. Arterial stiffness may be increased in CLD survivors due to increased smooth muscle tone of the pre-resistance and resistance vessels rather than the loss of elasticity in the large arteries. This review explores the long term effects of CLD on the pulmonary and systemic circulations along with their clinical correlates and therapeutic approaches.
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Affiliation(s)
- Chuen Yeow Poon
- Department of Child Health, School of Medicine, Cardiff University, University Hospital of Wales, Heath Park, Cardiff CF14 4XN, UK.
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27
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Fike CD, Aschner JL. Looking beyond PPHN: the unmet challenge of chronic progressive pulmonary hypertension in the newborn. Pulm Circ 2013; 3:454-66. [PMID: 24618533 DOI: 10.1086/674438] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Abstract Infants with forms of pulmonary hypertension (PH) that persist or develop beyond the first week of life are an understudied group of patients with up to 40%-60% mortality. The clinical management of the progressive PH that develops in these infants is challenging because of the nonspecific signs and symptoms of clinical presentation, the limited diagnostic sensitivity of standard echocardiographic techniques, and the lack of proven therapies. The signaling mechanisms that underlie the structural and functional abnormalities in the pulmonary circulation of these infants are not yet clear. The ability to improve outcomes for these patients awaits technological advances to improve diagnostic capabilities and therapeutic discoveries made in basic science laboratories that can be tested in randomized clinical trials.
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Affiliation(s)
- Candice D Fike
- 1 Department of Pediatrics, Vanderbilt University School of Medicine, and Monroe Carell Jr. Children's Hospital at Vanderbilt, Nashville, Tennessee, USA
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Stuart BD, Sekar P, Coulson JD, Choi SEJ, McGrath-Morrow SA, Collaco JM. Health-care utilization and respiratory morbidities in preterm infants with pulmonary hypertension. J Perinatol 2013; 33:543-7. [PMID: 23328926 DOI: 10.1038/jp.2012.170] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To assess health-care utilization and risk of respiratory morbidities in preterm infants with bronchopulmonary dysplasia (BPD) and pulmonary hypertension (PH). STUDY DESIGN Retrospective data were obtained from subjects (n=109) attending a BPD clinic. Subjects were stratified by the presence or absence of PH before and after 2 months of age. Analytic methods included t-tests, χ(2) tests and regression. RESULT Subjects with BPD and PH present after 2 months of age were hospitalized for 2.2 months longer than those without PH (P=0.02). These subjects were 4.5 times more likely to receive home supplemental oxygen or mechanical ventilation (P=0.03). No difference in the risk of respiratory morbidities after initial hospital discharge was seen with PH. CONCLUSION PH in preterm infants is associated with longer initial hospitalizations and a higher likelihood of requiring home respiratory support. This has implications for counseling families and reducing the medical, psychosocial, and economic burden of BPD and PH.
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Affiliation(s)
- B D Stuart
- Eudowood Division of Pediatric Respiratory Sciences, Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA
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Plakkal N, Soraisham AS, Trevenen C, Freiheit EA, Sauve R. Histological chorioamnionitis and bronchopulmonary dysplasia: a retrospective cohort study. J Perinatol 2013; 33:441-5. [PMID: 23238570 DOI: 10.1038/jp.2012.154] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To examine the association between histological chorioamnionitis (HC) with or without fetal inflammatory response (FIR) and bronchopulmonary dysplasia (BPD) in preterm infants. STUDY DESIGN We conducted a retrospective cohort study of infants born at <29 weeks gestation admitted to the neonatal intensive care unit from 2000 to 2006, who had placental histology. We compared the incidence of BPD among three groups: No HC group, HC without FIR group and HC with FIR group. The multivariable model based on generalized estimating equation was fitted to estimate the adjusted risk ratios (aRR) and 95% confidence intervals (CIs) for BPD and combined outcome of BPD or death. RESULT Of 529 infants, 84 (16%) had HC without FIR, 186 (35%) had HC with FIR and 259 (49%) had no HC. Compared with the no HC group, HC with and without FIR group infants were of lower gestational age and singleton births. Multivariable modeling based on generalized estimating equation revealed that HC with FIR is associated with decreased risk of both BPD (aRR 0.88, 95% CI 0.81 to 0.95) and the combined outcome of BPD or death (aRR 0.91, 95% CI 0.86 to 0.97). HC without FIR showed a trend toward reduction in BPD (aRR 0.93, 95% CI 0.86 to 1.00). CONCLUSIONS HC with FIR is associated with decreased risk of both BPD and the combined outcome of BPD or death in preterm infants.
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Affiliation(s)
- N Plakkal
- Department of Pediatrics and Alberta Children's Hospital Research Institute for Child and Maternal Health, University of Calgary, Calgary, AT, Canada
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30
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Sewing ACP, Kantores C, Ivanovska J, Lee AH, Masood A, Jain A, McNamara PJ, Tanswell AK, Jankov RP. Therapeutic hypercapnia prevents bleomycin-induced pulmonary hypertension in neonatal rats by limiting macrophage-derived tumor necrosis factor-α. Am J Physiol Lung Cell Mol Physiol 2012; 303:L75-87. [DOI: 10.1152/ajplung.00072.2012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Bleomycin-induced lung injury is characterized in the neonatal rat by inflammation, arrested lung growth, and pulmonary hypertension (PHT), as observed in human infants with severe bronchopulmonary dysplasia. Inhalation of CO2 (therapeutic hypercapnia) has been described to limit cytokine production and to have anti-inflammatory effects on the injured lung; we therefore hypothesized that therapeutic hypercapnia would prevent bleomycin-induced lung injury. Spontaneously breathing rat pups were treated with bleomycin (1 mg/kg/d ip) or saline vehicle from postnatal days 1–14 while being continuously exposed to 5% CO2 (PaCO2 elevated by 15–20 mmHg), 7% CO2 (PaCO2 elevated by 35 mmHg), or normocapnia. Bleomycin-treated animals exposed to 7%, but not 5%, CO2, had significantly attenuated lung tissue macrophage influx and PHT, as evidenced by normalized pulmonary vascular resistance and right ventricular systolic function, decreased right ventricular hypertrophy, and attenuated remodeling of pulmonary resistance arteries. The level of CO2 neither prevented increased tissue neutrophil influx nor led to improvements in decreased lung weight, septal thinning, impaired alveolarization, or decreased numbers of peripheral arteries. Bleomycin led to increased expression and content of lung tumor necrosis factor (TNF)-α, which was found to colocalize with tissue macrophages and to be attenuated by exposure to 7% CO2. Inhibition of TNF-α signaling with the soluble TNF-2 receptor etanercept (0.4 mg/kg ip from days 1–14 on alternate days) prevented bleomycin-induced PHT without decreasing tissue macrophages and, similar to CO2, had no effect on arrested alveolar development. Our findings are consistent with a preventive effect of therapeutic hypercapnia with 7% CO2 on bleomycin-induced PHT via attenuation of macrophage-derived TNF-α. Neither tissue macrophages nor TNF-α appeared to contribute to arrested lung development induced by bleomycin. That 7% CO2 normalized pulmonary vascular resistance and right ventricular function without improving inhibited airway and vascular development suggests that vascular hypoplasia does not contribute significantly to functional changes of PHT in this model.
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Affiliation(s)
- A. Charlotte P. Sewing
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Crystal Kantores
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Julijana Ivanovska
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Alvin H. Lee
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Azhar Masood
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Division of Neonatology, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Amish Jain
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Division of Neonatology, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Patrick J. McNamara
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Division of Neonatology, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - A. Keith Tanswell
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Division of Neonatology, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Robert P. Jankov
- Physiology and Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Heart and Stroke Richard Lewar Centre of Excellence, University of Toronto, Toronto, Ontario, Canada
- Division of Neonatology, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
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Peng G, Ivanovska J, Kantores C, Van Vliet T, Engelberts D, Kavanagh BP, Enomoto M, Belik J, Jain A, McNamara PJ, Jankov RP. Sustained therapeutic hypercapnia attenuates pulmonary arterial Rho-kinase activity and ameliorates chronic hypoxic pulmonary hypertension in juvenile rats. Am J Physiol Heart Circ Physiol 2012; 302:H2599-611. [DOI: 10.1152/ajpheart.01180.2011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sustained therapeutic hypercapnia prevents pulmonary hypertension in experimental animals, but its rescue effects on established disease have not been studied. Therapies that inhibit Rho-kinase (ROCK) and/or augment nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) signaling can reverse or prevent progression of chronic pulmonary hypertension. Our objective in the present study was to determine whether sustained rescue treatment with inhaled CO2 (therapeutic hypercapnia) would improve structural and functional changes of chronic hypoxic pulmonary hypertension. Spontaneously breathing pups were exposed to normoxia (21% O2) or hypoxia (13% O2) from postnatal days 1–21 with or without 7% CO2 (PaCO2 elevated by ∼25 mmHg) or 10% CO2 (PaCO2 elevated by ∼40 mmHg) from days 14 to 21. Compared with hypoxia alone, animals exposed to hypoxia and 10% CO2 had significantly ( P < 0.05) decreased pulmonary vascular resistance, right-ventricular systolic pressure, right-ventricular hypertrophy, and medial wall thickness of pulmonary resistance arteries as well as decreased lung phosphodiesterase (PDE) V, RhoA, and ROCK activity. Rescue treatment with 10% CO2, or treatment with a ROCK inhibitor (15 mg/kg ip Y-27632 twice daily from days 14 to 21), also increased pulmonary arterial endothelial nitric oxide synthase and lung NO content. In contrast, cGMP content and cGMP-dependent protein kinase (PKG) activity were increased by exposure to 10% CO2, but not by ROCK inhibition with Y-27632. In vitro exposure of pulmonary artery smooth muscle cells to hypercapnia suppressed serum-induced ROCK activity, which was prevented by inhibition of PKG with Rp-8-Br-PET-cGMPS. We conclude that sustained hypercapnia dose-dependently inhibited ROCK activity, augmented NO-cGMP-PKG signaling, and led to partial improvements in the hemodynamic and structural abnormalities of chronic hypoxic PHT in juvenile rats. Increased PKG content and activity appears to play a major upstream role in CO2-induced suppression of ROCK activity in pulmonary arterial smooth muscle.
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Affiliation(s)
- Gary Peng
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Julijana Ivanovska
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Crystal Kantores
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Todd Van Vliet
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Division of Neonatology, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada; and
| | - Doreen Engelberts
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Brian P. Kavanagh
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- the 4Department of Anaesthesia, University of Toronto, Toronto, Ontario, Canada; and
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Masahiro Enomoto
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
| | - Jaques Belik
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Heart and Stroke Richard Lewar Centre of Excellence, University of Toronto, Toronto, Ontario, Canada
- Division of Neonatology, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada; and
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Amish Jain
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Division of Neonatology, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada; and
| | - Patrick J. McNamara
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Division of Neonatology, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada; and
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Robert P. Jankov
- Physiology & Experimental Medicine Program, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada
- Heart and Stroke Richard Lewar Centre of Excellence, University of Toronto, Toronto, Ontario, Canada
- Division of Neonatology, Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada; and
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
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Waszak P, Alphonse R, Vadivel A, Ionescu L, Eaton F, Thébaud B. Preconditioning enhances the paracrine effect of mesenchymal stem cells in preventing oxygen-induced neonatal lung injury in rats. Stem Cells Dev 2012; 21:2789-97. [PMID: 22533467 DOI: 10.1089/scd.2010.0566] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Bronchopulmonary dysplasia (BPD) remains a main complication of extreme prematurity. Bone marrow derived-mesenchymal stem cells (BM-MSC) prevent lung injury in an O(2)-induced model of BPD. The low level of lung BM-MSC engraftment suggests alternate mechanisms-beyond cell replacement-to account for their therapeutic benefit. We hypothesized that BM-MSC prevent O(2)-induced BPD through a paracrine-mediated mechanism and that preconditioning of BM-MSC would further enhance this paracrine effect. To this end, conditioned medium (CM) from BM-MSC (MSCcm) or preconditioned CM harvested after 24 h of BM-MSC exposure to 95% O(2) (MSC-O2cm) were administrated for 21 days to newborn rats exposed to 95% O(2) from birth until postnatal day (P)14. Rat pups exposed to hyperoxia had fewer and enlarged air spaces and exhibited signs of pulmonary hypertension (PH), assessed by echo-Doppler, right ventricular hypertrophy, and pulmonary artery medial wall thickness. Daily intraperitoneal administration of both CM preserved alveolar growth. MSC-O2cm exerted the most potent therapeutic benefit and also prevented PH. CM of lung fibroblasts (control cells) had no effect. MSCcm had higher antioxidant capacity than control fibroblast CM. Preconditioning did not increase the antioxidant capacity in MSC-O2cm but produced higher levels of the naturally occurring antioxidant stanniocalcin-1 in MSC-O2cm. Ex vivo preconditioning enhances the paracrine effect of BM-MSC and opens new therapeutic options for cell-based therapies. Ex vivo preconditioning may also facilitate the discovery of MSC-derived repair molecules.
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Affiliation(s)
- Paul Waszak
- Department of Pediatrics, Faculty of Medicine and Dentistry, Women and Children’s Health Research Institute, Cardiovascular Research Center, University of Alberta, Edmonton, Canada.
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Kim DH, Kim HS, Choi CW, Kim EK, Kim BI, Choi JH. Risk factors for pulmonary artery hypertension in preterm infants with moderate or severe bronchopulmonary dysplasia. Neonatology 2012; 101:40-6. [PMID: 21791938 DOI: 10.1159/000327891] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Accepted: 03/29/2011] [Indexed: 01/18/2023]
Abstract
BACKGROUND Despite the potential importance of pulmonary artery hypertension (PAH) in preterm infants with bronchopulmonary dysplasia (BPD), little is known about the risk factors for PAH. OBJECTIVES To investigate the risk factors for PAH in preterm infants with BPD. METHODS Infants diagnosed with BPD were assigned to the PAH group or non-PAH group except for infants with mild BPD who had no PAH. PAH was diagnosed on the basis of echocardiograms demonstrating elevated right ventricle pressure beyond the postnatal age of 2 months. Logistic regression analysis was done for the multivariate assessment of the risk factors for PAH in preterm infants with moderate or severe BPD. RESULTS A total of 98 infants among 145 infants with BPD were divided into a PAH group (n = 25) or non-PAH group (n = 73), while the remaining 47 infants had mild BPD with no PAH. Among the study patients, survival rate of the PAH group was significantly lower than that of the non-PAH group. Infants with PAH had more severe cases of BPD and underwent longer durations of oxygen therapy, conventional or high-frequency ventilation, and hospitalization compared to those without PAH. Low 5-min Apgar scores (≤6; relative risk (RR) 6.2; 95% confidence interval (CI) 1.4-28.0; p = 0.017) and oligohydramnios (RR 7.7; 95% CI 2.0-29.6; p = 0.030) were found to be significant risk factors for PAH according to multivariate analysis. CONCLUSIONS The present study shows that oligohydramnios is a specific risk factor for PAH in preterm infants with moderate or severe BPD.
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Affiliation(s)
- Do-Hyun Kim
- Department of Pediatrics, Dongguk University Ilsan Hospital, Goyang, Korea
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Lopez E, Mathlouthi J, Lescure S, Krauss B, Jarreau PH, Moriette G. Capnography in spontaneously breathing preterm infants with bronchopulmonary dysplasia. Pediatr Pulmonol 2011; 46:896-902. [PMID: 21465676 DOI: 10.1002/ppul.21445] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 02/12/2011] [Accepted: 02/15/2011] [Indexed: 11/09/2022]
Abstract
BACKGROUND In adult patients with chronic obstructive pulmonary disease, there is a gradient between end-tidal carbon dioxide (EtCO(2)) and arterial carbon dioxide pressure (PaCO(2)), and the slope of the ascending phase of the capnogram is decreased due to obstruction. Corresponding data are lacking in infants with bronchopulmonary dysplasia (BPD). OBJECTIVES To compare PCO(2) -EtCO(2) gradient and capnogram shape in two groups of spontaneously breathing preterm subjects: infants with BPD and infants without respiratory disease (controls). MATERIAL AND METHODS Capnography was performed at 36 weeks postmenstrual age in 20 infants (12 BPD with oxygen dependency, 8 controls). Respiratory rate and the components of the respiratory cycle were measured. The PCO(2) -EtCO(2) gradient was calculated using EtCO(2) values and simultaneously sampled capillary values (PcCO(2)). Capnograms were compared between groups. RESULTS In BPD subjects, respiratory rate was increased (60 ± 16 bpm vs 43 ± 16 bpm, P = 0.009); a widened PcCO(2) -EtCO(2) gradient was observed (13 ± 4 mmHg vs 0 ± 7 mmHg, P = 0.0013); the ascending phase of the capnogram was not decreased, whereas the initial inspiratory phase was prolonged (0.32 ± 0.05 vs 0.24 ± 0.04, P = 0.001). CONCLUSIONS Compared with healthy infants, a higher PcCO(2) -EtCO(2) gradient was observed in infants with BPD, suggesting that ventilation-perfusion mismatch may be present in these infants. The capnogram did not exhibit the characteristic shape of airway obstruction.
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Affiliation(s)
- Emmanuel Lopez
- AP-HP, Groupe Hospitalier Cochin-Saint Vincent de Paul, Service de Médecine Néonatale de Port-Royal, Paris, France.
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Wood AM, Holzer RJ, Texter KM, Hill SL, Gest AL, Welty SE, Cheatham JP, Yates AR. Transcatheter Elimination of Left-to-Right Shunts in Infants with Bronchopulmonary Dysplasia Is Feasible and Safe. CONGENIT HEART DIS 2011; 6:330-7. [DOI: 10.1111/j.1747-0803.2011.00540.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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36
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Gürakan B, Kayiran P, Oztürk N, Kayiran SM, Dindar A. Therapeutic combination of sildenafil and iloprost in a preterm neonate with pulmonary hypertension. Pediatr Pulmonol 2011; 46:617-20. [PMID: 21438177 DOI: 10.1002/ppul.21415] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 11/23/2010] [Accepted: 11/27/2010] [Indexed: 11/09/2022]
Abstract
While new pharmacological approaches have been demonstrated to effectively manage PH in adults, few reports have addressed PH treatment in neonates and infants. This case report describes the successful management of severe PH secondary to bronchopulmonary dysplasia, respiratory syncytial virus infection, and hypoxia in a preterm 4-month-old with the long-term use of orally administered sildenafil and inhaled iloprost.
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Affiliation(s)
- Berkan Gürakan
- Division of Neonatology, Department of Pediatrics, American Hospital, Istanbul, Turkey
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37
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Abstract
Infants of birth weight ≤2500 g are termed low birth weight (LBW). These children often have considerable morbidity from prematurity and intra-uterine growth restriction. Additionally, LBW infants have increased risk for cardiac and noncardiac congenital anomalies and may require surgery. Primary rather than palliative surgical repair of cardiac lesions has been preferred in recent years. However, LBW remains a risk factor for increased mortality and morbidity after open-heart surgery (OHS). There is a paucity of information about the anesthetic challenges presented by LBW infants undergoing OHS. This review summarizes the perioperative issues of relevance to anesthesiologists who manage these high-risk patients. Emphasis is placed on management concerns that are unique to LBW infants. Retrospective data from the authors' institution are provided for those aspects of anesthetic care that lack published studies. Successful outcome often requires substantial hospital resources and collaborative multi-disciplinary effort.
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Affiliation(s)
- Glyn D Williams
- Department of Anesthesiology, Stanford University, Lucile Packard Children’s Hospital, Stanford, CA, USA
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38
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Groves AM, Chiesa G, Durighel G, Goldring ST, Fitzpatrick JA, Uribe S, Razavi R, Hajnal JV, Edwards AD. Functional cardiac MRI in preterm and term newborns. Arch Dis Child Fetal Neonatal Ed 2011; 96:F86-91. [PMID: 20971721 PMCID: PMC3093932 DOI: 10.1136/adc.2010.189142] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/13/2010] [Indexed: 12/20/2022]
Abstract
OBJECTIVE To use cardiac MRI techniques to assess ventricular function and systemic perfusion in preterm and term newborns, to compare techniques to echocardiographic methods, and to obtain initial reference data. DESIGN Observational magnetic resonance and echocardiographic imaging study. SETTING Neonatal Unit, Queen Charlotte's and Chelsea Hospital, London, UK. Patients 108 newborn infants with median birth weight 1627 (580-4140) g, gestation 32 (25-42) weeks. RESULTS Mean (SD) flow volumes assessed by phase contrast (PC) imaging in 28 stable infants were left ventricular output (LVO) 222 (46), right ventricular output (RVO) 219 (47), superior vena cava (SVC) 95 (27) and descending aorta (DAo) 126 (32) ml/kg/min, with flow being higher at lower gestational age. Limits of agreement for repeated PC assessment of flow were LVO ±50.2, RVO ±55.5, SVC ±20.9 and DAo ±26.2 ml/kg/min. Mean (SD) LVO in 75 stable infants from three-dimensional models were 245 (47) ml/kg/min, with limits of agreement ±58.3 ml/kg/min. Limits of agreement for repeated echocardiographic assessment of LVO were ±108.9 ml/kg/min. CONCLUSIONS Detailed magnetic resonance assessments of cardiac function and systemic perfusion are feasible in newborn infants, and provide more complete data with greater reproducibility than existing echocardiographic methods. Functional cardiac MRI could prove to be a useful research technique to study small numbers of newborn infants in specialist centres; providing insights into the pathophysiology of circulatory failure; acting as an outcome measure in clinical trials of inotropic intervention and so guiding clinical practice in the wider neonatal community.
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Affiliation(s)
- Alan M Groves
- Department of Paediatrics, Hammersmith House, Hammersmith Hospital, Du Cane Road, London, UK.
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39
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Chen Y, Chang L, Li W, Rong Z, Liu W, Shan R, Pan R. Thioredoxin protects fetal type II epithelial cells from hyperoxia-induced injury. Pediatr Pulmonol 2010; 45:1192-200. [PMID: 20812253 DOI: 10.1002/ppul.21307] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Revised: 04/04/2010] [Accepted: 04/05/2010] [Indexed: 11/06/2022]
Abstract
Oxygen toxicity is known to be one of the major contributors to bronchopulmonary dysplasia, a chronic lung disease in premature infants. Thioredoxin (Trx) is an antioxidant that prevents oxidative stress-induced cell death, suggesting a potential therapeutic role in bronchopulmonary dysplasia. The aim of this study was to determine the role of Trx in the pathogenesis of hyperoxia-induced alveolar epithelial cell injury. Alveolar type II epithelial cells from fetal rat lung were exposed to hyperoxia in vitro in the presence or absence of recombinant human Trx (rhTrx 2 µg/ml). Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Apoptosis and levels of reactive oxygen species (ROS) were measured by flow cytometry. Activation of mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase-Akt (PI3K-Akt) pathways were detected by Western blotting. We also investigated the effects of rhTrx on the following antioxidants (superoxide dismutase, catalase, and glutathione peroxidase). Trx significantly reduced hyperoxia-induced cell death and increased cell viability. In addition, ROS generation in type II cells was inhibited by rhTrx under hyperoxic conditions. We demonstrated that rhTrx protected type II cells against hyperoxic injury via sustaining the extracellular signal regulated kinase and PI3K activation, and decreasing of c-Jun N-terminal protein kinase and p38 activation. The results also showed manganese superoxide dismutase and glutathione peroxidase activities were increased by rhTrx in type II cells exposed to hyperoxia.Taken together, these results demonstrate that rhTrx administration markedly attenuates hyperoxia-induced type II cell injury through reduction of ROS generation, elevation of antioxidant activities and regulation of both MAPK and PI3K-Akt signaling pathways.
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Affiliation(s)
- Yan Chen
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
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40
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Xu EZ, Kantores C, Ivanovska J, Engelberts D, Kavanagh BP, McNamara PJ, Jankov RP. Rescue treatment with a Rho-kinase inhibitor normalizes right ventricular function and reverses remodeling in juvenile rats with chronic pulmonary hypertension. Am J Physiol Heart Circ Physiol 2010; 299:H1854-64. [PMID: 20889845 DOI: 10.1152/ajpheart.00595.2010] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chronic pulmonary hypertension in infancy and childhood is characterized by a fixed and progressive increase in pulmonary arterial pressure and resistance, pulmonary arterial remodeling, and right ventricular hypertrophy and systolic dysfunction. These abnormalities are replicated in neonatal rats chronically exposed to hypoxia from birth in which increased activity of Rho-kinase (ROCK) is critical to injury, as evidenced by preventive effects of ROCK inhibitors. Our objective in the present study was to examine the reversing effects of a late or rescue approach to treatment with a ROCK inhibitor on the pulmonary and cardiac manifestations of established chronic hypoxic pulmonary hypertension. Rat pups were exposed to air or hypoxia (13% O(2)) from postnatal day 1 and were treated with Y-27632 (15 mg/kg) or saline vehicle by twice daily subcutaneous injection commencing on day 14, for up to 7 days. Treatment with Y-27632 significantly attenuated right ventricular hypertrophy, reversed arterial wall remodeling, and completely normalized right ventricular systolic function in hypoxia-exposed animals. Reversal of arterial wall remodeling was accompanied by increased apoptosis and attenuated content of endothelin (ET)-1 and ET(A) receptors. Treatment of primary cultured juvenile rat pulmonary artery smooth muscle cells with Y-27632 attenuated serum-stimulated ROCK activity and proliferation and increased apoptosis. Smooth muscle apoptosis was also induced by short interfering RNA-mediated knockdown of ROCK-II, but not of ROCK-I. We conclude that sustained rescue treatment with a ROCK inhibitor reversed both the hemodynamic and structural abnormalities of chronic hypoxic pulmonary hypertension in juvenile rats and normalized right ventricular systolic function. Attenuated expression and activity of ET-1 and its A-type receptor on pulmonary arterial smooth muscle was a likely contributor to the stimulatory effects of ROCK inhibition on apoptosis. In addition, our data suggest that ROCK-II may be dominant in enhancing survival of pulmonary arterial smooth muscle.
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Affiliation(s)
- Emily Z Xu
- Clinical Integrative Biology, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
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41
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Abstract
Bronchopulmonary dysplasia (BPD) is a common complication of preterm birth. Chest imaging is important in making the diagnosis of BPD, and in assessing for complications. More recently computerised tomography (CT) scanning has provided insights in to the pathophysiology of BPD. Studies in infants, young and school age children as well as young adults have consistently demonstrated abnormalities in the peripheral lung, possibly related either to small airway or alveolar disease. Advances in CT scanning may increase the clinical role for this modality, in addition newer techniques such as hyperpolarised gas magnetic resonance imaging are likely to provide further insights in to the nature of BPD and its effects on the developing lung.
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Affiliation(s)
- Andrew C Wilson
- Princess Margaret Hospital, Roberts Rd, Subiaco, Western Australia, Australia.
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42
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Kim GB. Pulmonary hypertension in infants with bronchopulmonary dysplasia. KOREAN JOURNAL OF PEDIATRICS 2010; 53:688-93. [PMID: 21189939 PMCID: PMC2994133 DOI: 10.3345/kjp.2010.53.6.688] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2010] [Accepted: 05/13/2010] [Indexed: 11/27/2022]
Abstract
An increase in the number of preterm infants and a decrease in the gestational age at birth have resulted in an increase in the number of patients with significant bronchopulmonary dysplasia (BPD) and secondary pulmonary hypertension (PH). PH contributes significantly to the high morbidity and mortality in the BPD patients. Therefore, regular monitoring for PH by using echocardiography and B-type natriuretic peptide (BNP) or N-terminal-proBNP must be conducted in the BPD patients with greater than moderate degree to prevent PH and to ensure early treatment if PH is present. In the BPD patients with significant PH, multi-modality treatment, including treatment for correcting an underlying disease, oxygen supply, use of diverse selective pulmonary vasodilators (inhaled nitric oxide, inhaled prostacyclins, sildenafil, and endothelin-receptor antagonist) and other methods, is mandatory.
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Affiliation(s)
- Gi Beom Kim
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea
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43
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McNamara PJ, Murthy P, Kantores C, Teixeira L, Engelberts D, van Vliet T, Kavanagh BP, Jankov RP. Acute vasodilator effects of Rho-kinase inhibitors in neonatal rats with pulmonary hypertension unresponsive to nitric oxide. Am J Physiol Lung Cell Mol Physiol 2008; 294:L205-13. [DOI: 10.1152/ajplung.00234.2007] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pulmonary hypertension (PHT) in neonates is often refractory to the current best therapy, inhaled nitric oxide (NO). The utility of a new class of pulmonary vasodilators, Rho-kinase (ROCK) inhibitors, has not been examined in neonatal animals. Our objective was to examine the activity and expression of RhoA/ROCK in normal and injured pulmonary arteries and to determine the short-term pulmonary hemodynamic (assessed by pulse wave Doppler) effects of ROCK inhibitors (15 mg/kg ip Y-27632 or 30 mg/kg ip fasudil) in two neonatal rat models of chronic PHT with pulmonary vascular remodeling (chronic hypoxia, 0.13 FiO2, or 1 mg·kg−1·day−1 ip chronic bleomycin for 14 days from birth). Activity of the RhoA/ROCK pathway and ROCK expression were increased in hypoxia- and bleomycin-induced PHT. In both models, severe PHT [characterized by raised pulmonary vascular resistance (PVR) and impaired right ventricular (RV) performance] did not respond acutely to inhaled NO (20 ppm for 15 min) or to a single bolus of a NO donor, 3-morpholinosydnonimine hydrochloride (SIN-1; 2 μg/kg ip). In contrast, a single intraperitoneal bolus of either ROCK inhibitor (Y-27632 or fasudil) completely normalized PVR but had no acute effect on RV performance. ROCK-mediated vasoconstriction appears to play a key role in chronic PHT in our two neonatal rat models. Inhibitors of ROCK have potential as a testable therapy in neonates with PHT that is refractory to NO.
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Jankov RP, Kantores C, Pan J, Belik J. Contribution of xanthine oxidase-derived superoxide to chronic hypoxic pulmonary hypertension in neonatal rats. Am J Physiol Lung Cell Mol Physiol 2008; 294:L233-45. [DOI: 10.1152/ajplung.00166.2007] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Xanthine oxidase (XO)-derived reactive oxygen species (ROS) formation contributes to experimental chronic hypoxic pulmonary hypertension in adults, but its role in neonatal pulmonary hypertension has received little attention. In rats chronically exposed to hypoxia (13% O2) for 14 days from birth, we examined the effects of ROS scavengers (U74389G 10 mg·kg−1·day−1 or Tempol 100 mg·kg−1·day−1 ip) or a XO inhibitor, Allopurinol (50 mg·kg−1·day−1 ip). Both ROS scavengers limited oxidative stress in the lung and attenuated hypoxia-induced vascular remodeling, confirming a critical role for ROS in this model. However, both interventions also significantly inhibited somatic growth and normal cellular proliferation in distal air spaces. Hypoxia-exposed pups had evidence of increased serum and lung XO activity, increased vascular XO-derived superoxide production, and vascular nitrotyrosine formation. These changes were all prevented by treatment with Allopurinol, which also attenuated hypoxia-induced vascular remodeling and partially reversed inhibited endothelium-dependent arterial relaxation, without affecting normal growth and proliferation. Collectively, our findings suggest that XO-derived superoxide induces endothelial dysfunction, thus impairing pulmonary arterial relaxation, and contributes to vascular remodeling in hypoxia-exposed neonatal rats. Due to the potential for adverse effects on normal growth, targeting XO may represent a superior “antioxidant” strategy to ROS scavengers for neonates with pulmonary hypertension.
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45
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Lovering AT, Romer LM, Haverkamp HC, Hokanson JS, Eldridge MW. Excessive Gas Exchange Impairment during Exercise in A Subject with A History of Bronchopulmonary Dysplasia And High Altitude Pulmonary Edema. High Alt Med Biol 2007; 8:62-7. [PMID: 17394419 DOI: 10.1089/ham.2006.0816] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A 27-year-old male subject (V(O2 max)), 92% predicted) with a history of bronchopulmonary dysplasia (BPD) and a clinically documented case of high altitude pulmonary edema (HAPE) was examined at rest and during exercise. Pulmonary function testing revealed a normal forced vital capacity (FVC, 98.1% predicted) and diffusion capacity for carbon monoxide (D(L(CO)), 91.2% predicted), but significant airway obstruction at rest [forced expiratory volume in 1 sec (FEV(1)), 66.5% predicted; forced expiratory flow at 50% of vital capacity (FEF(50)), 34.3% predicted; and FEV(1) /FVC 56.5%] that was not reversible with an inhaled bronchodilator. Gas exchange worsened from rest to exercise, with the alveolar to arterial P(O2) difference (AaD(O2)) increasing from 0 at rest to 41 mmHg at maximal normoxic exercise (VO(2) = 41.4 mL/kg/min) and from 11 to 31 mmHg at maximal hypoxic exercise (VO(2) = 21.9 mL/kg/min). Arterial P(O2) decreased to 67.8 and 29.9 mmHg at maximal normoxic and hypoxic exercise, respectively. These data indicate that our subject with a history of BPD is prone to a greater degree of exercise-induced arterial hypoxemia for a given VO(2) and F(I(O2)) than healthy age-matched controls, which may increase the subject's susceptibility to high altitude illness.
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Affiliation(s)
- Andrew T Lovering
- University of Wisconsin School of Medicine and Public Health, Department of Population Health Sciences, John Rankin Laboratory of Pulmonary Medicine, Madison, Wisconsin 53706-1532, USA.
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46
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Benjamin JT, Smith RJ, Halloran BA, Day TJ, Kelly DR, Prince LS. FGF-10 is decreased in bronchopulmonary dysplasia and suppressed by Toll-like receptor activation. Am J Physiol Lung Cell Mol Physiol 2006; 292:L550-8. [PMID: 17071719 DOI: 10.1152/ajplung.00329.2006] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Many extremely preterm infants continue to suffer from bronchopulmonary dysplasia, which results from abnormal saccular-stage lung development. Here, we show that fibroblast growth factor-10 (FGF-10) is required for saccular lung development and reduced in the lung tissue of infants with bronchopulmonary dysplasia. Although exposure to bacteria increases the risk of bronchopulmonary dysplasia, no molecular target has been identified connecting inflammatory stimuli and abnormal lung development. In an experimental mouse model of saccular lung development, activation of Toll-like receptor 2 (TLR2) or Toll-like receptor 4 (TLR4) inhibited FGF-10 expression, leading to abnormal saccular airway morphogenesis. In addition, Toll-mediated FGF-10 inhibition disrupted the normal positioning of myofibroblasts around saccular airways, similar to the mislocalization of myofibroblasts seen in patients with bronchopulmonary dysplasia. Reduced FGF-10 expression may therefore link the innate immune system and impaired lung development in bronchopulmonary dysplasia.
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Affiliation(s)
- John T Benjamin
- Departments of Pediatrics, Children's Hospital of Alabama, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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47
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Abstract
Successful transition to air breathing at birth depends on perinatal maturation of the gas exchange surface, resorption of fluid from the air spaces, and synthesis and secretion of pulmonary surfactant. Genetic mutations that alter lung development and/or cellular differentiation in the prenatal period, lung function in the perinatal period, or lung homeostasis in the postnatal period can lead to neonatal lethality or chronic lung disease. Current knowledge of the molecular pathways that regulate key prenatal, perinatal, and postnatal morphogenetic events has been shaped largely by remarkable advances in transgenic technologies. In this review, selected transgenic mouse models are highlighted to illustrate the power of this technology, which in many cases has provided important insights that otherwise could not have been obtained.
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Affiliation(s)
- James P Bridges
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, USA
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48
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49
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Abstract
Bronchopulmonary dysplasia is a chronic lung disease that affects premature babies and contributes to their morbidity and mortality. Improved survival of very immature infants has led to increased numbers of infants with this disorder. This increase puts a heavy burden on health resources since these infants need frequent re-admission to hospital in the first 2 years after birth and, even as adolescents, have lung-function abnormalities and persistent respiratory symptoms. Unlike the original description of the disease in 1967, premature infants can develop chronic oxygen dependency without severe, acute respiratory distress; this "new bronchopulmonary dysplasia" could be the result of impaired postnatal lung growth. Whether such infants subsequently have catch-up lung growth, especially if given corticosteroids postnatally, is unknown. No safe and effective preventive therapy has been identified, but promising new treatments directed either at reducing lung injury or improving lung growth are under study.
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Affiliation(s)
- John P Kinsella
- Department of Paediatrics, University of Colorado School of Medicine, Denver, USA.
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50
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Voelkel NF, Vandivier RW, Tuder RM. Vascular endothelial growth factor in the lung. Am J Physiol Lung Cell Mol Physiol 2006; 290:L209-21. [PMID: 16403941 DOI: 10.1152/ajplung.00185.2005] [Citation(s) in RCA: 296] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Vascular endothelial growth factor (VEGF) is a pluripotent growth and permeability factor that has a broad impact on endothelial cell function. The lung tissue is very rich in this protein; many different lung cells produce VEGF and also respond to VEGF. VEGF is critical for the development of the lung and serves as a maintenance factor during adult life. In addition to the physiological functions of this protein, there is increasing evidence that VEGF also plays a role in several acute and chronic lung diseases, such as acute lung injury, severe pulmonary hypertension, and emphysema. Here we provide a comprehensive overview of the rapidly expanding literature.
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Affiliation(s)
- Norbert F Voelkel
- University of Colorado Health Sciences Center, Pulmonary and Critical Care Division, 4200 E. Ninth Ave., C272, Denver, CO 80262, USA.
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