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Pulmonary function in extremely low birth weight infants with bronchopulmonary dysplasia before hospital discharge. J Perinatol 2021; 41:77-83. [PMID: 33041327 PMCID: PMC7548054 DOI: 10.1038/s41372-020-00856-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 09/02/2020] [Accepted: 09/26/2020] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To compare pulmonary function in extremely low birth weight (ELBW) infants with bronchopulmonary dysplasia (BPD) studied at 34-36 weeks postmenstrual age (PMA) with a reference group of "healthy" infants born at 34-36 weeks. We hypothesized that ELBW infants have decreased functional residual capacity (FRC) and respiratory compliance (Crs). STUDY DESIGN Pulmonary function testing was performed at 34-36 weeks PMA in infants with BPD and within 96 h of age in infants delivered at 34-36 weeks. RESULTS Twenty BPD patients and 20 healthy infants were studied. FRC (18.9 versus 26.2 mL/kg; adjusted 95% CI 5.0, 10.9; P < 0.001) and Crs (0.80 versus 1.29-mL/cm H2O/kg; 95% CI 0.31, 0.71; P < 0.001) were decreased in BPD patients. Respiratory resistance was increased in BPD patients. CONCLUSIONS ELBW infants with BPD have decreased pulmonary function compared to healthy infants delivered at 34-36 weeks. This suggests that infants with BPD have smaller lung volumes.
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McEvoy CT, Shorey-Kendrick LE, Milner K, Schilling D, Tiller C, Vuylsteke B, Scherman A, Jackson K, Haas DM, Harris J, Park BS, Vu A, Kraemer DF, Gonzales D, Bunten C, Spindel ER, Morris CD, Tepper RS. Vitamin C to Pregnant Smokers Persistently Improves Infant Airway Function to 12 Months of Age: A Randomised Trial. Eur Respir J 2020; 56:1902208. [PMID: 32616589 PMCID: PMC8029653 DOI: 10.1183/13993003.02208-2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 06/04/2020] [Indexed: 12/21/2022]
Abstract
BACKGROUND Vitamin C (500 mg·day-1) supplementation for pregnant smokers has been reported to increase newborn pulmonary function and infant forced expiratory flows (FEFs) at 3 months of age. Its effect on airway function through 12 months of age has not been reported. OBJECTIVE To assess whether vitamin C supplementation to pregnant smokers is associated with a sustained increased airway function in their infants through 12 months of age. METHODS This is a prespecified secondary outcome of a randomised, double-blind, placebo-controlled trial that randomised 251 pregnant smokers between 13 and 23 weeks of gestation: 125 to 500 mg·day-1 vitamin C and 126 to placebo. Smoking cessation counselling was provided. FEFs performed at 3 and 12 months of age were analysed by repeated measures analysis of covariance. RESULTS FEFs were performed in 222 infants at 3 months and 202 infants at 12 months of age. The infants allocated to vitamin C had significantly increased FEFs over the first year of life compared to those allocated to placebo. The overall increased flows were: 40.2 mL·sec-1 for FEF75 (adjusted 95% CI for difference 6.6 to 73.8; p=0.025); 58.3 mL·sec-1 for FEF50 (95% CI 10.9 to 105.8; p=0.0081); and 55.1 mL·sec-1 for FEF25-75 (95% CI, 9.7 to 100.5; p=0.013). CONCLUSIONS In offspring of pregnant smokers randomised to vitamin C versus placebo, vitamin C during pregnancy was associated with a small but significantly increased airway function at 3 and 12 months of age, suggesting a potential shift to a higher airway function trajectory curve. Continued follow-up is underway.
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Affiliation(s)
- Cindy T McEvoy
- Department of Pediatrics, Oregon Health & Science University, Portland, OR, USA
| | | | - Kristin Milner
- Department of Pediatrics, Oregon Health & Science University, Portland, OR, USA
| | - Diane Schilling
- Department of Pediatrics, Oregon Health & Science University, Portland, OR, USA
| | - Christina Tiller
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Brittany Vuylsteke
- Department of Pediatrics, Oregon Health & Science University, Portland, OR, USA
| | - Ashley Scherman
- Department of Pediatrics, Oregon Health & Science University, Portland, OR, USA
| | - Keith Jackson
- PeaceHealth Southwest Medical Center, Vancouver, WA, USA
| | - David M Haas
- Department of Obstetrics and Gynecology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Julia Harris
- Department of Pediatrics, Oregon Health & Science University, Portland, OR, USA
| | - Byung S Park
- Oregon Health & Science University-Portland State University, School of Public Health and Knight Cancer Institute, Portland, OR, USA
| | - Annette Vu
- Department of Medical Informatics and Clinical Epidemiology, Oregon Health & Science University, Portland, OR, USA
| | - Dale F Kraemer
- Department of Medical Informatics and Clinical Epidemiology, Oregon Health & Science University, Portland, OR, USA
| | - David Gonzales
- Division of Pulmonary & Critical Care Medicine, Oregon Health & Science University, Portland, OR, USA
| | | | - Eliot R Spindel
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR, USA
| | - Cynthia D Morris
- Department of Medical Informatics and Clinical Epidemiology, Oregon Health & Science University, Portland, OR, USA
- Oregon Clinical & Translational Research Institute, Oregon Health & Science University, Portland, OR, USA
| | - Robert S Tepper
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
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McEvoy CT, Shorey-Kendrick LE, Milner K, Schilling D, Tiller C, Vuylsteke B, Scherman A, Jackson K, Haas DM, Harris J, Schuff R, Park BS, Vu A, Kraemer DF, Mitchell J, Metz J, Gonzales D, Bunten C, Spindel ER, Tepper RS, Morris CD. Oral Vitamin C (500 mg/d) to Pregnant Smokers Improves Infant Airway Function at 3 Months (VCSIP). A Randomized Trial. Am J Respir Crit Care Med 2019; 199:1139-1147. [PMID: 30522343 PMCID: PMC6515875 DOI: 10.1164/rccm.201805-1011oc] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 12/07/2018] [Indexed: 11/16/2022] Open
Abstract
Rationale: We reported a randomized trial demonstrating daily supplemental vitamin C to pregnant smokers significantly improved newborn pulmonary function tests. The current study tests these results in a new cohort using infant pulmonary function tests. Objectives: To determine if infants of pregnant smokers randomized to daily supplemental vitamin C would have improved forced expiratory flows (FEFs) at 3 months of age compared with those randomized to placebo, and to investigate the association of the α5 nicotinic acetylcholine receptor. Methods: A randomized, double-blind, placebo-controlled trial was conducted at three centers. Two hundred fifty-one pregnant smokers were randomized at 13-23 weeks of gestation: 125 randomized to vitamin C (500 mg/d) and 126 to placebo. Measurements and Main Results: The primary outcome was FEF75 at 3 months of age performed with the raised volume rapid thoracic compression technique (Jaeger/Viasys). FEF50 and FEF25-75 obtained from the same expiratory curves were prespecified secondary outcomes. The infants of pregnant smokers randomized to vitamin C (n = 113) had the following FEFs at 3 months of age compared with those randomized to placebo (n = 109) as measured by FEF75 (200.7 vs. 188.7 ml/s; adjusted 95% confidence interval [CI] for difference, -3.33 to 35.64; P = 0.10), FEF50 (436.7 vs. 408.5 ml/s; adjusted 95% CI for difference, 6.10-61.30; P = 0.02), and FEF25-75 (387.4 vs. 365.8 ml/s; adjusted 95% CI for difference, 0.92-55.34; P = 0.04). Infant FEFs seemed to be negatively associated with the maternal risk alleles for the α5 nicotinic acetylcholine receptor (rs16969968). Conclusions: Although the primary outcome of FEF75 was not improved after vitamin C supplementation to pregnant smokers, the predetermined secondary outcomes FEF50 and FEF25-75 were significantly improved. These results extend our previous findings and demonstrate improved airway function (FEF50 and FEF25-75) at 3 months of age in infants after vitamin C supplementation to pregnant smokers. Clinical trial registered with www.clinicaltrials.gov (NCT01723696).
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Affiliation(s)
| | | | | | | | | | | | | | - Keith Jackson
- PeaceHealth Southwest Medical Center, Vancouver, Washington
| | - David M. Haas
- Department of Obstetrics and Gynecology, Indiana University School of Medicine, Indianapolis, Indiana
| | | | - Robert Schuff
- Department of Medical Informatics and Clinical Epidemiology
- Oregon Clinical & Translational Research Institute, and
| | - Byung S. Park
- Oregon Health & Science University-Portland State University School of Public Health and Knight Cancer Institute, Portland, Oregon; and
| | - Annette Vu
- Department of Medical Informatics and Clinical Epidemiology
| | | | | | - Jill Metz
- Department of Medical Informatics and Clinical Epidemiology
| | - David Gonzales
- Division of Pulmonary & Critical Care Medicine, Oregon Health & Science University, Portland, Oregon
| | | | - Eliot R. Spindel
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, Oregon
| | | | - Cynthia D. Morris
- Department of Medical Informatics and Clinical Epidemiology
- Oregon Clinical & Translational Research Institute, and
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Ehsan Z, Montgomery GS, Tiller C, Kisling J, Chang DV, Tepper RS. An infant with pulmonary interstitial glycogenosis: clinical improvement is associated with improvement in the pulmonary diffusion capacity. Pediatr Pulmonol 2014; 49:E17-20. [PMID: 23401236 DOI: 10.1002/ppul.22738] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Accepted: 09/05/2012] [Indexed: 11/10/2022]
Abstract
Pulmonary interstitial glycogenosis (PIG) is an idiopathic interstitial lung disease of infants. The underlying pulmonary pathophysiology of PIG has not been well characterized. Herein we report a term-gestation infant who presented with persistent tachypnea and hypoxia. A chest CT scan demonstrated a diffuse ground glass appearance and lung biopsy demonstrated increased alveolar septae cellularity with glycogen-containing cells, consistent with a diagnosis of PIG. At 3 months of age, pulmonary function testing included: pre- and post-bronchodilator forced expiratory flows using the raised-volume technique and the ratio of pulmonary diffusing capacity for carbon monoxide to alveolar volume (DLCO /VA ). He was prescribed 5 days of oral prednisolone (2mg/kg/day) and pulmonary function testing (PFT) was repeated at 5, 13, and 20 months of age. Initial PFTs demonstrated reduced forced vital capacity (FVC: Z-score = -2.36) and an increased ratio of forced expiratory volume in 0.5 sec to FVC (FEV0.5/FVC: Z-score = 1.15) with no significant change following an inhaled bronchodilator. There was also a marked reduction in DLCO /VA (Z-score = -4.74) compared to age-matched controls. Follow-up demonstrated progressive clinical improvement as well as an increase in Z-FVC and normalization of DLCO /VA . Our in vivo physiological findings are consistent with previous reports that symptom resolution correlated with histological thinning of the alveolar septae upon repeat lung biopsy. The restrictive lung disease we observed is consistent with expected reduced compliance of an alveolar interstitial lung process like PIG, whereas the absence of a reduction in FEV0.5/FVC confirms the absence of obstructive airway disease.
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Affiliation(s)
- Zarmina Ehsan
- Department of Pediatrics, Riley Hospital for Children, Indiana University School of Medicine, Indianapolis, Indiana
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Beydon N, Davis SD, Lombardi E, Allen JL, Arets HGM, Aurora P, Bisgaard H, Davis GM, Ducharme FM, Eigen H, Gappa M, Gaultier C, Gustafsson PM, Hall GL, Hantos Z, Healy MJR, Jones MH, Klug B, Lødrup Carlsen KC, McKenzie SA, Marchal F, Mayer OH, Merkus PJFM, Morris MG, Oostveen E, Pillow JJ, Seddon PC, Silverman M, Sly PD, Stocks J, Tepper RS, Vilozni D, Wilson NM. An official American Thoracic Society/European Respiratory Society statement: pulmonary function testing in preschool children. Am J Respir Crit Care Med 2007; 175:1304-45. [PMID: 17545458 DOI: 10.1164/rccm.200605-642st] [Citation(s) in RCA: 804] [Impact Index Per Article: 47.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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Abstract
Recent data indicate that clinicians and researchers should dismiss the myth that preschoolers are unable to perform spirometry. Reproducible, acceptable flow-volume curves are possible in this age group; however, modifications to the ATS/ERS adult criteria are critical due to physiologic differences. Reference data is available and the clinical applicability of this technique is being evaluated.
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de Bisschop C, Montandon G, Guénard H. Expiratory muscles modulate negative expiratory pressure-induced flow during muscular exercise. Respir Physiol Neurobiol 2006; 154:453-66. [PMID: 16446126 DOI: 10.1016/j.resp.2005.12.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2005] [Revised: 12/22/2005] [Accepted: 12/23/2005] [Indexed: 10/25/2022]
Abstract
The recruitment of expiratory muscles during exercise might be altered by the application of negative expiratory pressure (NEP) inducing a feature of expiratory flow limitation (EFL) called muscle EFL. To check this hypothesis EFL and expiratory muscle EMG (ExpEMG) were measured at rest and during exercise in eight healthy subjects. Six subjects performed isocapnic hyperventilation. At 5hPa NEP, 5/8 subjects had EFL during exercise. This limitation disappeared when NEP value was increased and did not appear during isocapnic hyperventilation. During exercise, in limited subjects, ExpEMG was significantly reduced during expiration with NEP as compared to control. Gastric pressure measured in a limited subject increased during expiration but less with NEP than without it, while this pressure measured in another, non-limited, subject decreased. An inhibitory reflex due to negative pressure could be responsible for muscle EFL by reducing expiratory muscle activity. The response to NEP during exercise should be interpreted with caution.
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Affiliation(s)
- Claire de Bisschop
- Laboratoire des Adaptations Physiologiques aux Activités Physiques, Faculté des Sciences du Sport, UPRES EA 3813, 4 Allée Jean Monnet, 86000 POITIERS, France.
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Forey P, Giroux-Metges MA, Sarni D, Goetghebeur D, Thirion S, Milic-Emili J, Bellet M. [Evaluation of a new method for detection of obstructive disease in children asthma: the negative expiratory pressure (NEP)]. Arch Pediatr 2005; 12:1338-43. [PMID: 16023842 DOI: 10.1016/j.arcped.2005.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2004] [Accepted: 05/21/2005] [Indexed: 11/19/2022]
Abstract
INTRODUCTION To take in charge of an asthmatic child it is necessary to evaluate the lung function. METHODS In this study, the Negative Expiratory Pressure (NEP) has been used for the first time in children with asthma. After lung spirometry by plethysmography, we have used the NEP to assess the prevalence of expiratory flow limitation (FL) during resting breath in 27 asthmatic children (mean age: 11 +/- 2,5 years) 3-4 days after a crisis in both sitting and supine positions. RESULTS All the children presented an obstructive defect (FEV 1: 63 +/- 13% med) and a dynamic hyperinflation (FRC: 128 +/- 25% med). According to the NEP, 11 children presented an expiratory flow limitation (FL). Asthma was more severe in the FL than in non-FL children (GINA 2002 classification). Among the 11 FL children, 5 were FL in both sitting and supine position and 6 only in supine. Nine of the 27 children were FL with the conventional method. NEP seems a more accurate method to assess the clinical gravity of asthma than FEV 1. The reduction of FRC in the supine position probably explains the greater incidence of FL in supine position. CONCLUSION Because of its easy execution, NEP seems to be well adapted for children. Links between FL detected by NEP and clinical signs of asthma has to be assessed by furthers studies including more patients.
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Affiliation(s)
- P Forey
- Service de pédiatrie, CHU Morvan, 29609 Brest cedex, France
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Aurora P, Stocks J, Oliver C, Saunders C, Castle R, Chaziparasidis G, Bush A. Quality control for spirometry in preschool children with and without lung disease. Am J Respir Crit Care Med 2004; 169:1152-9. [PMID: 15028561 DOI: 10.1164/rccm.200310-1453oc] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The reliability of spirometry is dependent on strict quality control. We examined whether quality control criteria recommended for adults could be applied to children aged 2-5 years. Forty-two children with cystic fibrosis and 37 healthy children attempted spirometry during their first visit to our laboratory. Whereas 59 children (75%) were able to produce a technically satisfactory forced expiration lasting 0.5 second, only 46 (58%) could produce an expiration lasting 1 second, with the youngest children having the most difficulty. Start of test criteria for adults were inappropriate for this age group, with only 16 of 59 children producing a volume of back extrapolation as a proportion of forced vital capacity of less than 5%, whereas all but 4 could produce a volume of back extrapolation of 80 ml or less. More than 90% of children were able to produce a second forced vital capacity and a second forced expired volume in 0.75 second within 10% of their highest. Errors in the spirometry software resulted in inaccurate reporting of expiratory duration and inappropriate timed expired volumes in some children. We describe recommendations for modified start of test and repeatability criteria for this age group, and for improvements in software to facilitate better quality control.
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Affiliation(s)
- Paul Aurora
- Portex Respiratory Unit, Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK.
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10
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Tauber E, Fazekas T, Eichler I, Eichstill C, Gartner C, Koller DY, Frischer T. Negative expiratory pressure: a new tool for evaluating lung function in children? Pediatr Pulmonol 2003; 35:162-8. [PMID: 12567383 DOI: 10.1002/ppul.10233] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The negative expiratory pressure technique (NEP) has been applied in adults with chronic obstructive pulmonary disease (COPD), demonstrating flow limitation in many of these patients. Because this technique does not require patient cooperation, it is of potential interest for application in the pediatric population. This study was performed to test the feasibility of NEP in children, and to further investigate it in children with asthma and cystic fibrosis (CF). We performed NEP (0.3-0.7 kPa) measurements in 14 healthy children (13.3 years, +/- 2.4), in 12 children with asthma (11.7 years, +/- 3.0), and in 17 children with CF (13.3 years, +/- 2.7). NEP-derived flow-volume loops were visually analyzed for flow limitation at tidal breathing. In addition, expiratory flow at 50% of tidal volume (TEF(50)) was measured. In healthy children, the intraclass coefficient of correlation was 77%, and intraindividual short- and long-term variability was 5.8% and 10.8%, respectively. In asthmatics, TEF(50) was lower compared with controls, and increased after inhalation of salbutamol. However, appropriate size-correction has still to be established. Measurement of TEF(50) using NEP is feasible in children. Despite good reproducibility in individual patients, the high intersubject variability may limit its usefulness as a clinical tool. In addition, the lack of flow limitation using NEP even in severely obstructed patients with CF warrants further investigation.
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Affiliation(s)
- Erich Tauber
- Department of General Pediatrics, Vienna University Children's Hospital, Vienna, Austria
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Abstract
In a group of 173 healthy preschool children 3-6 years of age (body height, 90-130 cm; 102 boys and 71 girls) out of total 279 children examined, maximum expiratory flow-volume (MEFV) curves were recorded in cross-sectional measurements. The majority (62%) of preschool children were able to generate an MEFV curve as correctly as older children. From the curves, maximum expiratory flows at 25%, 50%, and 75 % of vital capacity (MEF(25), MEF(50), and MEF(75)), peak expiratory flow (PEF), forced expiratory volume in 1 sec (FEV(1)), forced vital capacity (FVC), and area delineated by MEFV curve (A(ex)) were obtained. The purpose of the study was to establish reference values of forced expiratory parameters in preschool children suitable for assessment of lung function abnormalities in respiratory preschool children. The values of the studied parameters increased nonlinearly and correlated significantly with body height (P < 0.0001); the correlation was much lower with age. A simple power regression equation was calculated for the relationship between each parameter and body height. A best-fit regression equation relating functional parameters and body height was a power function. Based on the obtained regression equations with upper and lower limits, we prepared tables listing reference values of forced expiratory parameters in healthy Caucasian preschool children, against which patients can be compared. No statistically significant gender differences were observed for MEF(25), MEF(50), MEF(75), PEF, FEV(1), FVC, and A(ex) by extrapolation. The reference values were close to those obtained in our older children. A decline of the ratios PEF/FVC, FEV(1)/FVC and MEF/FVC with increasing body height suggested more patent airways in younger and smaller preschool children.
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Affiliation(s)
- A Zapletal
- Second Department of Pediatrics, University Hospital Motol, Prague, Czech Republic.
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Page K, Li J, Hershenson MB. p38 MAP kinase negatively regulates cyclin D1 expression in airway smooth muscle cells. Am J Physiol Lung Cell Mol Physiol 2001; 280:L955-64. [PMID: 11290520 DOI: 10.1152/ajplung.2001.280.5.l955] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have demonstrated that platelet-derived growth factor (PDGF) stimulates p38 mitogen-activated protein (MAP) kinase activation in bovine tracheal myocytes, suggesting that p38 is involved in growth regulation. We therefore examined whether p38 regulates expression of cyclin D1, a G(1) cyclin required for cell cycle traversal. The chemical p38 inhibitors SB-202190 and SB-203580 each increased basal and PDGF-induced cyclin D1 promoter activity and protein abundance. Overexpression of a dominant negative allele of MAP kinase kinase-3 (MKK3), an upstream activator of p38alpha, had similar effects. Conversely, active MKK3 and MKK6, both of which increase p38alpha activity, each decreased transcription from the cyclin D1 promoter. Together, these data demonstrate that p38 negatively regulates cyclin D1 expression. We tested whether p38 regulates cyclin D1 expression via inhibition of extracellular signal-regulated kinase (ERK) activation. Chemical inhibitors of p38 induced modest ERK phosphorylation and activation. However, dominant negative MKK3 was insufficient to activate ERK, and active MKK3 and MKK6 did not attenuate platelet-derived growth factor-mediated ERK activation. These data are consistent with the notion that p38alpha negatively regulates cyclin D1 expression via an ERK-independent pathway.
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Affiliation(s)
- K Page
- Department of Pediatrics, University of Chicago, Chicago, Illinois 60637-1470, USA
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13
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Chan ED, Riches DW. IFN-gamma + LPS induction of iNOS is modulated by ERK, JNK/SAPK, and p38(mapk) in a mouse macrophage cell line. Am J Physiol Cell Physiol 2001; 280:C441-50. [PMID: 11171562 DOI: 10.1152/ajpcell.2001.280.3.c441] [Citation(s) in RCA: 278] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nitric oxide (NO.) produced by inducible nitric oxide synthase (iNOS) mediates a number of important physiological and pathophysiological processes. The objective of this investigation was to examine the role of mitogen-activated protein kinases (MAPKs) in the regulation of iNOS and NO. by interferon-gamma (IFN-gamma) + lipopolysaccharide (LPS) in macrophages using specific inhibitors and dominant inhibitory mutant proteins of the MAPK pathways. The signaling pathway utilized by IFN-gamma in iNOS induction is well elucidated. To study signaling pathways that are restricted to the LPS-signaling arm, we used a subclone of the parental RAW 264.7 cell line that is unresponsive to IFN-gamma alone with respect to iNOS induction. In this RAW 264.7gammaNO(-) subclone, IFN-gamma and LPS are nevertheless required for synergistic activation of the iNOS promoter. We found that extracellular signal-regulated kinase (ERK) augmented and p38(mapk) inhibited IFN-gamma + LPS induction of iNOS. Dominant-negative MAPK kinase-4 inhibited iNOS promoter activation by IFN-gamma + LPS, also implicating the c-Jun NH(2)-terminal kinase (JNK) pathway in mediating iNOS induction. Inhibition of the ERK pathway markedly reduced IFN-gamma + LPS-induced tumor necrosis factor-alpha protein expression, providing a possible mechanism by which ERK augments iNOS expression. The inhibitory effect of p38(mapk) appears more complex and may be due to the ability of p38(mapk) to inhibit LPS-induced JNK activation. These results indicate that the MAPKs are important regulators of iNOS-NO. expression by IFN-gamma + LPS.
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Affiliation(s)
- E D Chan
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Health Sciences Center, Denver, Colorado 80206, USA.
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Eigen H, Bieler H, Grant D, Christoph K, Terrill D, Heilman DK, Ambrosius WT, Tepper RS. Spirometric pulmonary function in healthy preschool children. Am J Respir Crit Care Med 2001; 163:619-23. [PMID: 11254514 DOI: 10.1164/ajrccm.163.3.2002054] [Citation(s) in RCA: 166] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The purpose of this study was to evaluate spirometric lung function in normal children ages 3 to 6 yr. Spirometric measurements were obtained at nursery and daycare centers by experienced pediatric pulmonary function technicians. Of 307 children recruited, 259 fulfilled our criteria as normal. Of these, 82.6% (214) were able to perform technically acceptable and reproducible maneuvers during a testing session limited to 15 min. The regression model with log-transformed parameters of pulmonary function and height had the best correlations. After accounting for height in the model, other physical traits and health questionnaire items did not contribute significantly. PEFR, FVC, FEV1, and FEF25-75 all increased with increasing height; correlation coefficients were 0.73, 0.93, 0.92, and 0.67, respectively. The group mean coefficients of variation for replicate measurements of PEFR, FVC, FEV1, and FEF25-75 were 7.8%, 2.5%, 2.7%, and 8.3%, respectively. There was a significant decrease in the ratio FEV1/FVC with increasing height; the mean predicted FEV1/FVC was 0.97 at 90 cm height and 0.89 at 125 cm height. In conclusion, reproducible spirometry can be obtained in the majority of preschool children and has the potential to improve our assessment and management of pulmonary disease.
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Affiliation(s)
- H Eigen
- Department of Pediatrics, James Whitcomb Riley Hospital for Children, Indiana University Medical Center, Indianapolis, Indiana 46202, USA
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15
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Wodopia R, Ko HS, Billian J, Wiesner R, Bärtsch P, Mairbäurl H. Hypoxia decreases proteins involved in epithelial electrolyte transport in A549 cells and rat lung. Am J Physiol Lung Cell Mol Physiol 2000; 279:L1110-9. [PMID: 11076801 DOI: 10.1152/ajplung.2000.279.6.l1110] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Fluid reabsorption from alveolar space is driven by active Na reabsorption via epithelial Na channels (ENaCs) and Na-K-ATPase. Both are inhibited by hypoxia. Here we tested whether hypoxia decreases Na transport by decreasing the number of copies of transporters in alveolar epithelial cells and in lungs of hypoxic rats. Membrane fractions were prepared from A549 cells exposed to hypoxia (3% O(2)) as well as from whole lung tissue and alveolar type II cells from rats exposed to hypoxia. Transport proteins were measured by Western blot analysis. In A549 cells, alpha(1)- and beta(1)-Na-K-ATPase, Na/K/2Cl cotransport, and ENaC proteins decreased during hypoxia. In whole lung tissue, alpha(1)-Na-K-ATPase and Na/K/2Cl cotransport decreased. alpha- and beta-ENaC mRNAs also decreased in hypoxic lungs. Similar results were seen in alveolar type II cells from hypoxic rats. These results indicate a slow decrease in the amount of Na-transporting proteins in alveolar epithelial cells during exposure to hypoxia that also occurs in vivo in lungs from hypoxic animals. The reduced number of transporters might account for the decreased transport activity and impaired edema clearance in hypoxic lungs.
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Affiliation(s)
- R Wodopia
- Medical Clinic, Section Sports Medicine, University of Heidelberg, 69115 Heidelberg, Germany
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Portier F, Portmann A, Czernichow P, Vascaut L, Devin E, Benhamou D, Cuvelier A, Muir JF. Evaluation of home versus laboratory polysomnography in the diagnosis of sleep apnea syndrome. Am J Respir Crit Care Med 2000; 162:814-8. [PMID: 10988088 DOI: 10.1164/ajrccm.162.3.9908002] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The aim of this study was to compare home polysomnography (HoPSG) with laboratory polysomnography (LabPSG) in the diagnosis of sleep apnea syndrome (SAS). A total of 103 patients referred for investigation of SAS underwent two full polysomnographies, using the portable Minisomno device at home and the Respisomnographe in the laboratory (both devices manufactured by the same company). Twenty percent of home-studied device polysomnography (HoSD-PSG) recordings and 5% of LabPSG recordings were excluded from analysis either because of lost data or poor quality data. Sleep stage distribution and subjective quality of sleep were similar by both methods. Using LabPSG, the mean (+/- SD) RDI was 25.7 (+/- 30.6) versus 22.8 (+/- 31.5) using HoSD-PSG (p > 0.05). Absolute differences between the home and laboratory respiratory disturbance index (RDI) were less than 10 for 65% of patients. Discordant RDIs (i.e., differences greater than 10) were observed for 63% of individuals with severe SAS (RDI > 30) versus 22% of those with normal or moderate SAS (RDI </= 30) (p < 0.05). Higher RDI differences were associated with poor airflow signal at home. Forty-seven percent of patients preferred LabPSG. Our results suggest that HoSD-PSG was not feasible for 33% of patients; there was no evidence of a better quality of sleep and recording tolerance at home; the reliability of HoSD-PSG for SAS diagnosis depends on the quality of data obtained under unattended conditions.
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Affiliation(s)
- F Portier
- Service de Pneumologie, Centre Hospitalo-Universitaire de Rouen, Rouen, France
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Jones MH, Davis SD, Kisling JA, Howard JM, Castile R, Tepper RS. Flow limitation in infants assessed by negative expiratory pressure. Am J Respir Crit Care Med 2000; 161:713-7. [PMID: 10712312 DOI: 10.1164/ajrccm.161.3.9807135] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Forced expiratory flows by the rapid compression technique are often used to assess airway function in infants; however, it remains unclear as to whether flow limitation (FL) is achieved. Studies in adults have used negative expiratory pressure (NEP) at the airway opening as a noninvasive technique to assess whether FL is achieved. An increase in flow with NEP indicates that FL has not been achieved, whereas no increase in flow with NEP indicates FL has been achieved. In the adult studies, the change in flow was assessed by visual inspection of the flow-volume curve. We evaluated whether NEP could be used to assess FL during forced expiration in infants. In addition, we quantified the change in flow secondary to NEP. We applied -5 cm H(2)O NEP to four infants during forced expiratory maneuvers. The step increase in flow with NEP was always less than 5% at high jacket compression pressures and consistent with FL. For one subject, FL was also confirmed from isovolume pressure flow-curves measured with an esophageal catheter. We conclude that NEP can be used in infants to assess FL during forced expiratory maneuvers by the rapid compression technique.
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Affiliation(s)
- M H Jones
- Riley Children's Hospital, Indianapolis, Indiana, USA
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