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Ayyar VS, Jusko WJ. Transitioning from Basic toward Systems Pharmacodynamic Models: Lessons from Corticosteroids. Pharmacol Rev 2020; 72:414-438. [PMID: 32123034 DOI: 10.1124/pr.119.018101] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Technology in bioanalysis, -omics, and computation have evolved over the past half century to allow for comprehensive assessments of the molecular to whole body pharmacology of diverse corticosteroids. Such studies have advanced pharmacokinetic and pharmacodynamic (PK/PD) concepts and models that often generalize across various classes of drugs. These models encompass the "pillars" of pharmacology, namely PK and target drug exposure, the mass-law interactions of drugs with receptors/targets, and the consequent turnover and homeostatic control of genes, biomarkers, physiologic responses, and disease symptoms. Pharmacokinetic methodology utilizes noncompartmental, compartmental, reversible, physiologic [full physiologically based pharmacokinetic (PBPK) and minimal PBPK], and target-mediated drug disposition models using a growing array of pharmacometric considerations and software. Basic PK/PD models have emerged (simple direct, biophase, slow receptor binding, indirect response, irreversible, turnover with inactivation, and transduction models) that place emphasis on parsimony, are mechanistic in nature, and serve as highly useful "top-down" methods of quantitating the actions of diverse drugs. These are often components of more complex quantitative systems pharmacology (QSP) models that explain the array of responses to various drugs, including corticosteroids. Progressively deeper mechanistic appreciation of PBPK, drug-target interactions, and systems physiology from the molecular (genomic, proteomic, metabolomic) to cellular to whole body levels provides the foundation for enhanced PK/PD to comprehensive QSP models. Our research based on cell, animal, clinical, and theoretical studies with corticosteroids have provided ideas and quantitative methods that have broadly advanced the fields of PK/PD and QSP modeling and illustrates the transition toward a global, systems understanding of actions of diverse drugs. SIGNIFICANCE STATEMENT: Over the past half century, pharmacokinetics (PK) and pharmacokinetics/pharmacodynamics (PK/PD) have evolved to provide an array of mechanism-based models that help quantitate the disposition and actions of most drugs. We describe how many basic PK and PK/PD model components were identified and often applied to the diverse properties of corticosteroids (CS). The CS have complications in disposition and a wide array of simple receptor-to complex gene-mediated actions in multiple organs. Continued assessments of such complexities have offered opportunities to develop models ranging from simple PK to enhanced PK/PD to quantitative systems pharmacology (QSP) that help explain therapeutic and adverse CS effects. Concurrent development of state-of-the-art PK, PK/PD, and QSP models are described alongside experimental studies that revealed diverse CS actions.
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Affiliation(s)
- Vivaswath S Ayyar
- Department of Pharmaceutical Sciences University at Buffalo, School of Pharmacy and Pharmaceutical Sciences, Buffalo, New York
| | - William J Jusko
- Department of Pharmaceutical Sciences University at Buffalo, School of Pharmacy and Pharmaceutical Sciences, Buffalo, New York
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Carnaghan H, James CP, Charlesworth PB, Ghionzoli M, Pereira S, Elkhouli M, Baud D, De Coppi P, Ryan G, Shah PS, Davenport M, David AL, Pierro A, Eaton S. Antenatal corticosteroids and outcomes in gastroschisis: A multicenter retrospective cohort study. Prenat Diagn 2020; 40:991-997. [PMID: 32400889 DOI: 10.1002/pd.5727] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 03/08/2020] [Accepted: 04/25/2020] [Indexed: 11/07/2022]
Abstract
OBJECTIVE In gastroschisis, there is evidence to suggest that gut dysfunction develops secondary to bowel inflammation; we aimed to evaluate the effect of maternal antenatal corticosteroids administered for obstetric reasons on time to full enteral feeds in a multicenter cohort study of gastroschisis infants. METHODS A three center, retrospective cohort study (1992-2013) with linked fetal/neonatal gastroschisis data was conducted. The primary outcome measure was time to full enteral feeds (a surrogate measure for bowel function) and secondary outcome measure was length of hospital stay. Analysis included Mann-Whitney and Cox regression. RESULTS Of 500 patients included in the study, 69 (GA at birth 34 [25-38] weeks) received antenatal corticosteroids and 431 (GA at birth 37 [31-41] weeks) did not. Antenatal corticosteroids had no effect on the rate of reaching full feeds (Hazard ratio HR 1.0 [95% CI: 0.8-1.4]). However, complex gastroschisis (HR 0.3 [95% CI: 0.2-0.4]) was associated with an increased time to reach full feeds and later GA at birth (HR 1.1 per week increase in GA [95% CI: 1.1-1.2]) was associated with a decreased time to reach full feeds. CONCLUSION Maternal antenatal corticosteroids use, under current antenatal steroid protocols, in gastroschisis is not associated with an improvement in neonatal outcomes such as time to full enteral feeds or length of hospital stay.
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Affiliation(s)
- Helen Carnaghan
- UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children, London, UK
| | | | | | - Marco Ghionzoli
- UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children, London, UK
| | - Susana Pereira
- Departamento de Obstetrícia e Ginecologia, Centro Hospitalar Tondela-Viseu, Viseu, Portugal
| | - Mohamed Elkhouli
- Fetal Medicine Unit, University College London Hospital, London, UK
| | - David Baud
- Fetal Medicine Unit, Mount Sinai Hospital, University of Toronto, Ontario, Canada
- Materno-fetal and Obstetrics Research Unit, Department of Gynaecology and Obstetrics, University Hospital of Lausanne CHUV, Lausanne, Switzerland
| | - Paolo De Coppi
- UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children, London, UK
| | - Greg Ryan
- Fetal Medicine Unit, Mount Sinai Hospital, University of Toronto, Ontario, Canada
| | - Prakesh S Shah
- Division of Neonatology, Mount Sinai Hospital, University of Toronto, Ontario, Canada
| | - Mark Davenport
- Paediatric Surgery Unit, King's College Hospital, London, UK
| | - Anna L David
- Fetal Medicine Unit, University College London Hospital, London, UK
| | - Agostino Pierro
- Division of General and Thoracic Surgery, The Hospital for Sick Children, University of Toronto, Ontario, Canada
| | - Simon Eaton
- UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children, London, UK
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Kemp MW, Jobe AH, Usuda H, Nathanielsz PW, Li C, Kuo A, Huber HF, Clarke GD, Saito M, Newnham JP, Stock SJ. Efficacy and safety of antenatal steroids. Am J Physiol Regul Integr Comp Physiol 2018; 315:R825-R839. [PMID: 29641233 DOI: 10.1152/ajpregu.00193.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Antenatal steroids (ANS) are among the most important and widely utilized interventions to improve outcomes for preterm infants. A significant body of evidence demonstrates improved outcomes in preterm infants (24-34 wk) delivered between 1 and 7 days after the administration of a single course of ANS. Moreover, ANS have the advantage of being widely available, low cost, and easily administered via maternal intramuscular injection. The use of ANS to mature the fetal lung is, however, not without contention. Their use in pregnancy is not FDA approved, and treatment doses and regimens remain largely unoptimized. Their mode of use varies considerably between countries, and there are lingering concerns regarding the safety of exposing the fetus to high doses of exogenous steroids. A significant proportion of women deliver outside the 1- to 7-day therapeutic window after ANS treatment, and this delay may be associated with an increased risk of adverse outcomes for both mother and baby. Today, animal-based studies are one means by which key questions of dosing and safety relating to ANS may be resolved, allowing for further refinement(s) of this important therapy. Complementary approaches using nonhuman primates, sheep, and rodents have provided invaluable advances to our understanding of how exogenous steroid exposure impacts fetal development. Focusing on these three major model groups, this review highlights the role of three key animal models (sheep, nonhuman primates, rodents) in the development of antenatal steroid therapy, and provides an up-to-date synthesis of current efforts to refine this therapy in an era of personalised medicine.
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Affiliation(s)
- Matthew W Kemp
- Division of Obstetrics and Gynaecology, University of Western Australia , Perth , Australia
- Tohoku University Hospital, Sendai, Miyagi , Japan
| | - Alan H Jobe
- Division of Obstetrics and Gynaecology, University of Western Australia , Perth , Australia
- Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Centre , Cincinnati, Ohio
| | - Haruo Usuda
- Division of Obstetrics and Gynaecology, University of Western Australia , Perth , Australia
- Tohoku University Hospital, Sendai, Miyagi , Japan
| | | | - Cun Li
- Department of Animal Science, University of Wyoming , Laramie, Wyoming
| | - Anderson Kuo
- Department of Radiology, University of Texas Health Science Center San Antonio , San Antonio, Texas
| | - Hillary F Huber
- Department of Animal Science, University of Wyoming , Laramie, Wyoming
| | - Geoffrey D Clarke
- Department of Radiology, University of Texas Health Science Center San Antonio , San Antonio, Texas
| | - Masatoshi Saito
- Division of Obstetrics and Gynaecology, University of Western Australia , Perth , Australia
- Tohoku University Hospital, Sendai, Miyagi , Japan
| | - John P Newnham
- Division of Obstetrics and Gynaecology, University of Western Australia , Perth , Australia
| | - Sarah J Stock
- Division of Obstetrics and Gynaecology, University of Western Australia , Perth , Australia
- Usher Institute of Population Health Sciences and Informatics, University of Edinburgh, Edinburgh, United Kingdom
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Antenatal dexamethasone vs. betamethasone dosing for lung maturation in fetal sheep. Pediatr Res 2017; 81:496-503. [PMID: 27861467 DOI: 10.1038/pr.2016.249] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 09/26/2016] [Indexed: 11/09/2022]
Abstract
BACKGROUND Dexamethasone-phosphate (Dex-PO4) and the combination betamethasone-phosphate (Beta-PO4) + betamethasone-acetate (Beta-Ac) are the most used antenatal corticosteroids to promote fetal lung maturation. We compared fetal lung maturation induced by Beta-Ac+Beta-PO4, Dex-PO4, or Beta-PO4 alone. METHODS Pregnant ewes received two intramuscular doses 24 h apart of 0.25 mg/kg/dose of Beta-Ac+Beta-PO4, Dex-PO4 or Beta-PO4; or 2 doses of 0.125 mg/kg/dose of Beta-PO4 at 6, 12, or 24 h intervals. Fetuses were delivered 48 h after the first dose and ventilated for 30 min. We assessed ventilatory variables, vital signs, and blood gas. After ventilation pressure-volume curves were measured and lungs were sampled for analysis. RESULTS All treatments improved lung compliance and ventilation efficiency. Only Beta-Ac + Beta-PO4 required lower positive inspiratory pressure compared with control. Beta-Ac + Beta-PO4 and Beta-PO4 alone, but not Dex-PO4, increased the mRNA of surfactant proteins compared with control. Low-dose Beta-PO4 did not increase mRNA of surfactant proteins. There were no differences among Beta-PO4 treatment intervals. CONCLUSION Beta-Ac + Beta-PO4 given as two doses 24 h apart was more effective in promoting fetal lung maturation than Dex-PO4 or Beta-PO4 alone, consistent with a prolonged exposure provided by the Beta-Ac + Beta-PO4. These results support the clinical use of combined Beta-Ac + Beta-PO4 preparations over phosphate corticosteroids alone for fetal lung maturation.
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Kemp MW, Saito M, Usuda H, Molloy TJ, Miura Y, Sato S, Watanabe S, Clarke M, Fossler M, Scmidt A, Kallapur SG, Kramer BW, Newnham JP, Jobe AH. Maternofetal pharmacokinetics and fetal lung responses in chronically catheterized sheep receiving constant, low-dose infusions of betamethasone phosphate. Am J Obstet Gynecol 2016; 215:775.e1-775.e12. [PMID: 27555319 DOI: 10.1016/j.ajog.2016.08.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/24/2016] [Accepted: 08/10/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND Antenatal steroids are standard of care for cases of anticipated preterm labor to improve neonatal outcomes. However, steroids are potent drugs, and their use in pregnancy remains largely unoptimized. OBJECTIVE The objective of the study was to measure the maternofetal pharmacokinetics of constant, low-dose intravenous betamethasone phosphate infusions and correlate these data with the transcriptional effect exerted by subclinical betamethasone exposures on the ovine fetal lung. STUDY DESIGN Thirty-two ewes carrying a single fetus had surgery to catheterize fetal and maternal jugular veins at 116 days of gestation (term, 150 days). Animals were recovered for 2 days and then were randomized to receive 2 sequential maternal intravenous infusions of either (n = 4/group) of the following: 1) saline, 0.125, 0.04, or 0.0125 mg/kg betamethasone phosphate over 3 hours; or 2) saline, 0.25, 0.08, or 0.025 mg/kg betamethasone phosphate over 12 hours. Each infusion was separated by 2 days. Fetal lung tissue was collected for analysis using quantitative polymerase chain reaction and an ovine-specific microarray. Plasma betamethasone levels from time-course catheter samples were determined by mass spectrometry. Data were assessed for distribution, variance, and tested by an analysis of variance. RESULTS Betamethasone was detectable (>1 ng/mL) in fetal plasma only in animals randomized to 0.125 mg/kg 3 hour or 0.250 mg/kg 12 hour infusions. Fetal betamethasone half-lives were 1.7-2.8 times greater than maternal values. At maximum concentration, fetal plasma betamethasone levels were approximately 10% of maternal levels. Compared with saline control, all animals, other than those receiving 0.0125 mg/kg 3 hour betamethasone phosphate infusions, had evidence of dose-dependent glucocorticoid transcriptional responses in the fetal lung. CONCLUSION Constant maternal betamethasone infusions delivering substantially lower fetal and maternal betamethasone maximal concentrations than those achieved with current clinical treatment protocols were associated with dose-dependent changes in glucocorticoid-response markers in the fetal lung. Further studies to determine the minimally efficacious dose of steroids for improving outcomes in preterm infants should be viewed as a priority.
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Salim R, Suleiman A, Colodner R, Nachum Z, Goldstein LH, Shalev E. Measurement of betamethasone concentration in maternal serum treated for fetal lung maturity; Is it feasible? Reprod Biol Endocrinol 2016; 14:7. [PMID: 26860904 PMCID: PMC4748478 DOI: 10.1186/s12958-016-0142-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 01/28/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The association between maternal serum concentration of betamethasone given for fetal lung maturity and perinatal outcome has not been investigated. This may be due to an absence of a reliable method for measuring serum betamethasone concentrations. We aimed in the current study to assess the feasibility of a specific ELISA kit to measure the concentrations of betamethasone in maternal serum and to examine the trend of sequential measurements after a course of betamethasone for fetal lung maturity. METHODS Pregnant women at risk for preterm birth who received betamethasone between 24 and 34 weeks of gestation were prospectively included. Serum concentrations were determined before administering betamethasone (baseline), and 36 hours, 48 hours, 72 hours, and 5 to 7 days after the 1(st) dose. Betamethasone concentration in samples was determined using Corticosteroid ELISA kit. The Friedman test was used to test whether there were significant differences between the measurements. RESULTS Five singleton pregnancies were included. Using the ELISA kit, betamethasone concentration in maternal serum samples was obtained for all women. Among the five measurements performed, the concentration was highest at 36 hours after the 1(st) dose and close to baseline at the 5(th) measurement performed after 5 to 7 days (p < 0.05). Serum concentration varied at each time point between the five women but similar trend was observed. CONCLUSION Betamethasone concentration is measurable in the serum of pregnant women with this ELISA kit.
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Affiliation(s)
- Raed Salim
- Department of Obstetrics and Gynecology, Emek Medical Center, Afula, 18101, Israel.
- Rappaport Faculty of Medicine, Technion, Haifa, Israel.
| | - Abeer Suleiman
- Department of Obstetrics and Gynecology, Emek Medical Center, Afula, 18101, Israel.
| | - Raul Colodner
- Clinical Microbiology Laboratory, Emek Medical Center, Afula, Israel.
| | - Zohar Nachum
- Department of Obstetrics and Gynecology, Emek Medical Center, Afula, 18101, Israel.
- Rappaport Faculty of Medicine, Technion, Haifa, Israel.
| | - Lee H Goldstein
- Rappaport Faculty of Medicine, Technion, Haifa, Israel.
- Department of Internal Medicine C, Clinical Pharmacology and toxicology Unit, Emek Medical Center, Afula, Israel.
| | - Eliezer Shalev
- Department of Obstetrics and Gynecology, Emek Medical Center, Afula, 18101, Israel.
- Rappaport Faculty of Medicine, Technion, Haifa, Israel.
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Abstract
Since their introduction more than forty years ago, antenatal glucocorticoids have become a cornerstone in the management of preterm birth and have been responsible for substantial reductions in neonatal mortality and morbidity. Clinical trials conducted over the past decade have shown that these benefits may be increased further through administration of repeat doses of antenatal glucocorticoids in women at ongoing risk of preterm and in those undergoing elective cesarean at term. At the same time, a growing body of experimental animal evidence and observational data in humans has linked fetal overexposure to maternal glucocorticoids with increased risk of cardiovascular, metabolic and other disorders in later life. Despite these concerns, and somewhat surprisingly, there has been little evidence to date from randomized trials of longer-term harm from clinical doses of synthetic glucocorticoids. However, with wider clinical application of antenatal glucocorticoid therapy there has been greater need to consider the potential for later adverse effects. This paper reviews current evidence for the short- and long-term health effects of antenatal glucocorticoids and discusses the apparent discrepancy between data from randomized clinical trials and other studies.
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Loehle M, Schwab M, Kadner S, Maner KM, Gilbert JS, Brenna JT, Ford SP, Nathanielsz PW, Nijland MJ. Dose-response effects of betamethasone on maturation of the fetal sheep lung. Am J Obstet Gynecol 2010; 202:186.e1-7. [PMID: 20022315 DOI: 10.1016/j.ajog.2009.09.033] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Revised: 06/11/2009] [Accepted: 09/28/2009] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Glucocorticoid administration to women in preterm labor improves neonatal mortality and morbidity. Fetal exposure to glucocorticoid levels higher than those appropriate to the current gestational stage has multiple organ system effects. Some, eg, fetal hypertension, are maximal at lower than the clinical dose. We hypothesized that the clinical dose has supramaximal lung maturational effects. STUDY DESIGN We evaluated the full, half, and quarter clinical betamethasone dose (12 mg/70 kg or 170 microg/kg intramuscularly twice 24 hours apart) on fetal sheep lung pressure volume curves (PVC) after 48 hours' exposure at 0.75 gestation. We measured key messenger RNAs and protein products that affect lung function and total lung dipalmitoyl phosphatidyl choline. RESULTS Full and half doses had similar PVC and total lung dipalmitoyl phosphatidyl choline effects. Messenger RNA for surfactant proteins A, B, and D and elastin increased in a dose-dependent fashion. CONCLUSION Half the clinical betamethasone dose produces maximal PVC improvement in fetal sheep at 0.75 gestation.
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Tegethoff M, Pryce C, Meinlschmidt G. Effects of intrauterine exposure to synthetic glucocorticoids on fetal, newborn, and infant hypothalamic-pituitary-adrenal axis function in humans: a systematic review. Endocr Rev 2009; 30:753-89. [PMID: 19837868 DOI: 10.1210/er.2008-0014] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND Synthetic glucocorticoids are commonly used in reproductive medicine. Fetal organ systems are highly sensitive to changes in the intrauterine environment, including overexposure to glucocorticoids. Structural and functional alterations resulting from such changes may persist throughout life and have been associated with diverse diseases. One system that could be particularly sensitive to fetal glucocorticoid overexposure is the hypothalamic-pituitary-adrenal (hpa) axis. Many human studies have investigated this possibility, but a systematic review to identify consistent, emergent findings is lacking. METHODS We systematically review 49 human studies, assessing the effects of intrauterine exposure to synthetic glucocorticoids on fetal, neonate, and infant hpa function. RESULTS Study quality varied considerably, but the main findings held true after restricting the analyses to higher-quality studies: intrauterine exposure to synthetic glucocorticoids reduces offspring hpa activity under unstimulated conditions after pain but not pharmacological challenge. Although reduced unstimulated hpa function appears to recover within the first 2 wk postpartum, blunted hpa reactivity to pain is likely to persist throughout the first 4 months of life. There is some evidence that the magnitude of the effects is correlated with the total amount of glucocorticoids administered and varies with the time interval between glucocorticoid exposure and hpa assessment. CONCLUSIONS This systematic review has allowed the demonstration of the way in which intrauterine exposure to various regimens of synthetic glucocorticoids affects various forms of hpa function. As such, it guides future studies in terms of which variables need to be focused on in order to further strengthen the understanding of such therapy, whilst continuing to profit from its clinical benefits.
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Affiliation(s)
- Marion Tegethoff
- National Centre of Competence in Research, Swiss Etiological Study of Adjustment and Mental Health (sesam), University of Basel, Birmannsgasse 8, CH-4055 Basel, Switzerland
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Been JV, Zimmermann LJI, Debeer A, Kloosterboer N, van Iwaarden JF. Bronchoalveolar lavage fluid from preterm infants with chorioamnionitis inhibits alveolar epithelial repair. Respir Res 2009; 10:116. [PMID: 19930634 PMCID: PMC2784455 DOI: 10.1186/1465-9921-10-116] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Accepted: 11/23/2009] [Indexed: 11/24/2022] Open
Abstract
Background Preterm infants are highly susceptible to lung injury. While both chorioamnionitis and antenatal steroids induce lung maturation, chorioamnionitis is also associated with adverse lung development. We investigated the ability of bronchoalveolar lavage fluid (BALF) from ventilated preterm infants to restore alveolar epithelial integrity after injury in vitro, depending on whether or not they were exposed to chorioamnionitis or antenatal steroids. For this purpose, a translational model for alveolar epithelial repair was developed and characterised. Methods BALF was added to mechanically wounded monolayers of A549 cells. Wound closure was quantified over time and compared between preterm infants (gestational age < 32 wks) exposed or not exposed to chorioamnionitis and antenatal steroids (≥ 1 dose). Furthermore, keratinocyte growth factor (KGF) and vascular endothelial growth factor (VEGF) were quantified in BALF, and their ability to induce alveolar epithelial repair was evaluated in the model. Results On day 0/1, BALF from infants exposed to antenatal steroids significantly increased epithelial repair (40.3 ± 35.5 vs. -6.3 ± 75.0% above control/mg protein), while chorioamnionitis decreased wound-healing capacity of BALF (-2.9 ± 87.1 vs. 40.2 ± 36.9% above control/mg protein). BALF from patients with chorioamnionitis contained less KGF (11 (0-27) vs. 0 (0-4) pg/ml) and less detectable VEGF (66 vs. 95%) on day 0. BALF levels of VEGF and KGF correlated with its ability to induce wound repair. Moreover, KGF stimulated epithelial repair dose-dependently, although the low levels in BALF suggest KGF is not a major modulator of BALF-induced wound repair. VEGF also stimulated alveolar epithelial repair, an effect that was blocked by addition of soluble VEGF receptor-1 (sVEGFr1/Flt-1). However, BALF-induced wound repair was not significantly affected by addition of sVEGFr1. Conclusion Antenatal steroids improve the ability of BALF derived from preterm infants to stimulate alveolar epithelial repair in vitro. Conversely, chorioamnionitis is associated with decreased wound-healing capacity of BALF. A definite role for KGF and VEGF in either process could not be established. Decreased ability to induce alveolar epithelial repair after injury may contribute to the association between chorioamnionitis and adverse lung development in mechanically ventilated preterm infants.
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Affiliation(s)
- Jasper V Been
- Department of Paediatrics, School for Oncology and Developmental Biology (GROW), Maastricht University Medical Centre, PO Box 5800, 6202 AZ Maastricht, the Netherlands.
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Been JV, Kornelisse RF, Rours IGIJG, Lima Passos V, De Krijger RR, Zimmermann LJI. Early postnatal blood pressure in preterm infants: effects of chorioamnionitis and timing of antenatal steroids. Pediatr Res 2009; 66:571-6. [PMID: 19668111 DOI: 10.1203/pdr.0b013e3181b7c4da] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Previous studies suggest postnatal blood pressure in preterm infants to be decreased by chorioamnionitis and increased by antenatal steroids (AS). We examined the adjusted effects of both antenatal modulators on postnatal blood pressure (BP), with separate effects reported for histologic chorioamnionitis with or without fetal involvement and timing of AS. General characteristics, BP, and heart rate values during the first 72 h after birth were obtained from 271 infants with gestational age <or=32.0 wk. In unadjusted analyses, chorioamnionitis was associated with lower BP, most prominently so in infants with fetal involvement, without an effect on hypotension incidence. AS increased BP and decreased the incidence of hypotension when administered within 7 d before birth. In a multivariable mixed model analysis, the AS effect remained significant, whereas chorioamnionitis was not independently predictive of postnatal BP. Other variables associated with increased postnatal BP were gestational age and umbilical artery pH, whereas hemolysis, elevated liver enzymes, low platelets syndrome was associated with decreased BP. In conclusion, AS seem to increase postnatal BP and decrease hypotension in preterm infants when given within 7 d before birth. Conversely, chorioamnionitis did not significantly affect postnatal BP after multivariable adjustment.
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Affiliation(s)
- Jasper V Been
- Department of Paediatrics, Maastricht University Medical Centre, Maastricht, The Netherlands.
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Jellyman JK, Gardner DS, McGarrigle HH, Fowden AL, Giussani DA. Antenatal glucocorticoid therapy increases glucose delivery to cerebral circulations during acute hypoxemia in fetal sheep during late gestation. Am J Obstet Gynecol 2009; 201:82.e1-8. [PMID: 19371860 DOI: 10.1016/j.ajog.2009.01.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2008] [Revised: 11/25/2008] [Accepted: 01/13/2009] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To determine the effects of 2 maternal injections with dexamethasone on the calculated oxygen and glucose deliveries to fetal cerebral and peripheral circulations during acute hypoxemia in sheep. STUDY DESIGN Beginning at 124 days, ewes received 2 intramuscular injections of either dexamethasone (2 x 12 mg, n = 10) or saline solution (2 x 2 mL, n = 12) 24 hours apart. Hypoxemia (1 hour) was induced 32 hours after the first injection (H1) and 3 days after the second (H2). RESULTS In saline solution-treated fetuses, glucose delivery was unchanged or increased in femoral and carotid circulations, respectively, during H1 and H2. In dexamethasone-treated fetuses, the increase in glucose delivery to the head tended to be greater during H1 and was significantly enhanced in dexamethasone- vs saline solution-treated fetuses during H2. CONCLUSION Two maternal injections with dexamethasone significantly enhanced glucose delivery to the head during acute hypoxemia in the ovine fetus.
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Affiliation(s)
- Juanita K Jellyman
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
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Abstract
OBJECTIVE To determine in fetal sheep the effect of betamethasone on myelination in relation to stage of myelination, number of treatment courses, dose, and route of administration. METHODS Fetal expression of myelin basic protein (MBP), a marker of mature oligodendrocytes and myelin, was determined between 0.27 and 0.93 gestation. Short-term betamethasone effects were examined 24 hours after one maternal intramuscular treatment course (weight adjusted to equal the clinical dose of 2 x 8 mg betamethasone to a 70-kg woman) at 0.63, 0.75, and 0.87 gestation or after continuous 48-hour fetal intravenous infusion at 0.75 and 0.87 gestation. Lasting effects were examined 20 days after one and two treatment courses weight-adapted to the clinical dose of 2 x 8 mg or 2 x 12 mg betamethasone at 0.75 gestation. RESULTS Myelin basic protein immunoreactivity was first detected in the internal capsule at 0.53 gestation, followed by the centrum semiovale, the superficial white matter, and corpus callosum at 0.63 gestation. Within 24 hours after treatment, betamethasone reduced the number of mature oligodendrocytes and MBP immunoreactivity. The effect decreased with gestational age. Maternal and fetal betamethasone administration had similar effects. Loss of MBP immunoreactivity was not reversed 20 days after two treatment courses, independent of dose. CONCLUSION Betamethasone-induced delayed cerebral myelination is dependent on the stage of brain development in sheep. Betamethasone-related disturbances in myelination and any potential contribution to childhood behavior deficits need to be confirmed in clinical studies.
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Chandrasekar I, Eis A, Konduri GG. Betamethasone attenuates oxidant stress in endothelial cells from fetal lambs with persistent pulmonary hypertension. Pediatr Res 2008; 63:67-72. [PMID: 18043518 DOI: 10.1203/pdr.0b013e31815b43ee] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We investigated the effects of betamethasone on oxidative stress and impaired vasodilation in a lamb model of persistent pulmonary hypertension (PPHN). We treated pregnant ewes following fetal ductal ligation with betamethasone or saline for 48 h before delivery. Response of fetal pulmonary arteries to nitric oxide synthase (NOS) agonist adenosine triphosphate (ATP) and nitric oxide (NO) donor, s-nitroso-n-acetyl-penicillamine (SNAP) was determined in tissue bath. Pulmonary artery endothelial cells (PAEC) from fetal lambs with ductal ligation or sham ligation were treated with betamethasone or its vehicle for 48 h. Expression of endothelial NOS (eNOS), endothelin, endothelin-B (ET-B) receptor, and CuZn- and Mn-superoxide dismutase (SOD) in PAEC was studied. Intracellular cGMP and superoxide levels and interaction of eNOS with heat shock protein 90 (Hsp90) were determined in PAEC. Antenatal betamethasone improved the relaxation response of pulmonary arteries to ATP and SNAP in PPHN. PPHN was associated with decreases in eNOS and ET-B receptor and increase in prepro-endothelin mRNA levels. Betamethasone decreased prepro-endothelin mRNA and ET-1 pro-peptide levels and increased eNOS and MnSOD protein levels in PPHN. Betamethasone reversed the increased superoxide/decreased cGMP levels and restored Hsp90-eNOS interactions in PPHN. Betamethasone reduces oxidative stress and improves response of pulmonary arteries to vasodilators in lambs with PPHN.
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Affiliation(s)
- Indira Chandrasekar
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin 53201, USA
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McCallum J, Smith N, Schwab M, Coksaygan T, Reinhardt B, Nathanielsz P, Richardson BS. Effects of antenatal glucocorticoids on cerebral substrate metabolism in the preterm ovine fetus. Am J Obstet Gynecol 2008; 198:105.e1-9. [PMID: 17880903 DOI: 10.1016/j.ajog.2007.05.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2006] [Revised: 02/19/2007] [Accepted: 05/01/2007] [Indexed: 10/22/2022]
Abstract
OBJECTIVE Although the benefits of antenatal glucocorticoids are well known for infants who are born preterm, there is increasing evidence of adverse effects on brain development, which may relate to altered metabolic activity. We have determined the effect of maternal glucocorticoid administration at doses that are used clinically on cerebral substrate metabolism in the preterm ovine fetus. STUDY DESIGN Chronically instrumented pregnant sheep at 0.85 gestation received 2 intramuscular injections of betamethasone at 170 microg/kg maternal weight (n = 13) or saline (n = 10) 24 hours apart together with a continuous infusion of L-[1-(13)C] leucine to the fetus. Fetal cerebral substrate arteriovenous differences (O2, glucose, leucine, leucine enrichment) and blood flow (fluorescent microspheres) were measured at baseline, 24 hours after the first betamethasone/saline injection (late beta/saline 1), and 4 hours after the second betamethasone/saline injection (early beta/saline 2) to obtain substrate deliveries and fractional extractions. RESULTS Fetal pH, blood gases, and metabolites were little changed in either group over the course of the study, except for glucose values in the betamethasone animals, which increased 1.4- and 1.9-fold, measured late beta 1 and early beta 2, respectively (both P < .01). Cerebral blood flow, although little changed in the control group or at late beta 1, was decreased at early beta 2 by approximately 30% (P < .05). As such, early beta 2 animals showed a decrease in cerebral O2 delivery of approximately 20% (P = .06) and conversely an increase in cerebral glucose delivery of 1.4- and 1.3-fold at late beta 1 (P < .05) and early beta 2 (P = .08), respectively. Fractional extraction values for these substrates were not changed significantly, which resulted in corresponding decreases in estimated O2 uptake and increases in estimated glucose uptake, such that the glucose/oxygen quotient (as an index of glucose oxidative metabolism) measured 1.6 at early beta 2, which was considerably greater than baseline values at 1.1 (P < .05). Fractional extraction values for leucine and leucine enrichment averaged 2%-3%; although somewhat higher in the betamethasone animals, none of the between or within group differences were significant. CONCLUSION Fetal cerebral metabolism in the preterm ovine fetus is altered by antenatal glucocorticoid administration, which is comparable with that used in human pregnancy, and includes an acute decrease in cerebral blood flow and a probable increase in anaerobic glucose metabolism. Although likely of short duration in conjunction with peak glucocorticoid levels, these metabolic effects may place the developing brain at added risk for superimposed hypoxic injury.
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Affiliation(s)
- Jeremy McCallum
- Department of Obstetrics and Gynecology, Faculty of Medicine and Dentistry, University of Western Ontario, London, ON, Canada
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Antonow-Schlorke I, Müller T, Brodhun M, Wicher C, Schubert H, Nathanielsz PW, Witte OW, Schwab M. Betamethasone-related acute alterations of microtubule-associated proteins in the fetal sheep brain are reversible and independent of age during the last one-third of gestation. Am J Obstet Gynecol 2007; 196:553.e1-6. [PMID: 17547892 DOI: 10.1016/j.ajog.2006.10.898] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2006] [Revised: 08/02/2006] [Accepted: 10/25/2006] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The purpose of this study was to examine whether glucocorticoid effects on neuronal cytoskeleton, which we have shown previously at 0.87 gestation when the hypothalamo-pituitary-adrenal axis matures, are age-dependent and reversible. STUDY DESIGN Fetal sheep received 3.3 microg kg(-1) h(-1) betamethasone (n = 10) or saline solution (n = 9) intravenously over 48 hours at 0.75 gestation (ie, before the hypothalamo-pituitary-adrenal axis matures and when betamethasone is administered clinically). RESULTS Betamethasone diminished microtubule-associated protein (MAP) 1B and 2 immunoreactivity in the frontal neocortex and caudate putamen (P < .05) and MAP2 in the hippocampus (P < .05), which is similar to the effects that are seen at 0.87 gestation. In agreement, the number of glucocorticoid receptors did not differ at both ages. Loss of MAP1B and MAP2 immunoreactivity was not accompanied by neuronal death and was reversible within 24 hours. CONCLUSION Alteration of neuronal cytoskeletal proteins caused by antenatal betamethasone exposure is transient and independent of age during late gestation.
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