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Jobe AH. Dr. Tetsuro Fujiwara-My Memories from the Early Days of Dr. Fujiwara's Research. Biomedicines 2024; 12:218. [PMID: 38255323 PMCID: PMC10813076 DOI: 10.3390/biomedicines12010218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 12/18/2023] [Accepted: 12/22/2023] [Indexed: 01/24/2024] Open
Abstract
This brief commentary honors Dr. Tesuro Fujiwara, the first person to treat infants with respiratory distress syndrome by instilling surfactant into their trachea. In the 1960s, mortality from RDS, which could only be treated with oxygen, was about 50 percent. Based on the physiology Fujiwara learned that lung immaturity could be treated with doses of surfactant from animals in sheep models. He then made a surfactant from cow lungs called Servanta and treated 10 infants with RDS, who all had a large improvement in oxygenation. Other new therapies, such as continuous positive airway pressure and newer infant ventilators-in combination with surfactant therapy have decreased infant mortality to less than 1% from RDS in the most recent US infant death statistics.
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Affiliation(s)
- Alan H Jobe
- Perinatal Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati School of Medicine, Cincinnati, OH 45229, USA
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2
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Abstract
Pulmonary surfactant is a critical component of lung function in healthy individuals. It functions in part by lowering surface tension in the alveoli, thereby allowing for breathing with minimal effort. The prevailing thinking is that low surface tension is attained by a compression-driven squeeze-out of unsaturated phospholipids during exhalation, forming a film enriched in saturated phospholipids that achieves surface tensions close to zero. A thorough review of past and recent literature suggests that the compression-driven squeeze-out mechanism may be erroneous. Here, we posit that a surfactant film enriched in saturated lipids is formed shortly after birth by an adsorption-driven sorting process and that its composition does not change during normal breathing. We provide biophysical evidence for the rapid formation of an enriched film at high surfactant concentrations, facilitated by adsorption structures containing hydrophobic surfactant proteins. We examine biophysical evidence for and against the compression-driven squeeze-out mechanism and propose a new model for surfactant function. The proposed model is tested against existing physiological and pathophysiological evidence in neonatal and adult lungs, leading to ideas for biophysical research, that should be addressed to establish the physiological relevance of this new perspective on the function of the mighty thin film that surfactant provides.
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Affiliation(s)
- Fred Possmayer
- Department of Biochemistry, Western University, London, Ontario N6A 3K7, Canada
- Department of Obstetrics/Gynaecology, Western University, London, Ontario N6A 3K7, Canada
| | - Yi Y Zuo
- Department of Mechanical Engineering, University of Hawaii at Manon, Honolulu, Hawaii 96822, United States
- Department of Pediatrics, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96826, United States
| | - Ruud A W Veldhuizen
- Department of Physiology & Pharmacology, Western University, London, Ontario N6A 5C1, Canada
- Department of Medicine, Western University, London, Ontario N6A 3K7, Canada
- Lawson Health Research Institute, London, Ontario N6A 4V2, Canada
| | - Nils O Petersen
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
- Department of Chemistry, Western University, London, Ontario N6A 5B7, Canada
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Dankhara N, Holla I, Ramarao S, Kalikkot Thekkeveedu R. Bronchopulmonary Dysplasia: Pathogenesis and Pathophysiology. J Clin Med 2023; 12:4207. [PMID: 37445242 DOI: 10.3390/jcm12134207] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/15/2023] [Accepted: 06/19/2023] [Indexed: 07/15/2023] Open
Abstract
Bronchopulmonary dysplasia (BPD), also known as chronic lung disease, is the most common respiratory morbidity in preterm infants. "Old" or "classic" BPD, as per the original description, is less common now. "New BPD", which presents with distinct clinical and pathological features, is more frequently observed in the current era of advanced neonatal care, where extremely premature infants are surviving because of medical advancements. The pathogenesis of BPD is complex and multifactorial and involves both genetic and environmental factors. This review provides an overview of the pathology of BPD and discusses the influence of several prenatal and postnatal factors on its pathogenesis, such as maternal factors, genetic susceptibility, ventilator-associated lung injury, oxygen toxicity, sepsis, patent ductus arteriosus (PDA), and nutritional deficiencies. This in-depth review draws on existing literature to explore these factors and their potential contribution to the development of BPD.
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Affiliation(s)
- Nilesh Dankhara
- Department of Pediatrics, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Ira Holla
- Department of Pediatrics, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Sumana Ramarao
- Department of Pediatrics, University of Mississippi Medical Center, Jackson, MS 39216, USA
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Nord A, Bianco F, Salomone F, Ricci F, Schlun M, Linner R, Cunha-Goncalves D. Nebulization of High-Dose Poractant Alfa in Newborn Piglets on Nasal Continuous Positive Airway Pressure Yields Therapeutic Lung Doses of Phospholipids. Am J Perinatol 2022; 39:1001-1007. [PMID: 33242911 DOI: 10.1055/s-0040-1721392] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVE It is not known how much surfactant must be nebulized to reach a lung dose of phospholipids equivalent to that obtained by the instillation of 200 mg/kg of surfactant. We aimed to assess the feasibility of nebulizing a high-dose of poractant alfa with the eFlow-Neos investigational vibrating-membrane nebulizer in newborn piglets on nasal continuous positive airway pressure (nCPAP) and to determine whether this intervention would yield therapeutic lung doses of phospholipids. STUDY DESIGN Twelve 1-day-old piglets on nCPAP received 600 mg/kg of poractant alfa admixed with technetium-99m via nebulization. Six piglets receiving 200 mg/kg of instilled synthetic surfactant served as controls. Lung deposition (percentage of the nominal dose) was determined by gamma scintigraphy, and the phospholipids' lung dose was calculated. RESULTS The lung dose of phospholipids (mean ± standard deviation [SD]) was 138 ± 96 mg/kg with nebulization, and 172 ± 24 mg/kg with instillation (p = 0.42). Nebulization took 58 ± 12 minutes. The arterial partial pressure of carbon dioxide increased from 6.7 ± 1.1 to 7.2 ± 1.1 kPa during nebulization (p = 0.04). Cerebral oximetry remained stable, and there was no hemodynamic instability. CONCLUSION Nebulization was well tolerated, and the mean lung dose of phospholipids was above 100 mg/kg, that is, not different from the instillation group. These experimental findings suggest that it may be feasible to reach therapeutic lung doses of phospholipids by surfactant nebulization during nCPAP. KEY POINTS · It is not known if effective lung doses of surfactant can be delivered by nebulization.. · Nebulization of high-dose surfactant in newborn piglets on nCPAP was well tolerated.. · A high-dose of nebulized poractant alfa yielded therapeutic lung doses of phospholipids..
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Affiliation(s)
- Anders Nord
- Pediatric Anesthesia and Intensive Care, Skåne University Hospital, Lund, Sweden.,Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Federico Bianco
- Department of Preclinical Pharmacology, R&D, Chiesi Farmaceutici S.p.A., Parma, Italy
| | - Fabrizio Salomone
- Department of Preclinical Pharmacology, R&D, Chiesi Farmaceutici S.p.A., Parma, Italy
| | - Francesca Ricci
- Department of Preclinical Pharmacology, R&D, Chiesi Farmaceutici S.p.A., Parma, Italy
| | | | - Rikard Linner
- Cardiothoracic Anesthesia and Intensive Care, Skåne University Hospital, Lund, Sweden.,Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
| | - Doris Cunha-Goncalves
- Pediatric Anesthesia and Intensive Care, Skåne University Hospital, Lund, Sweden.,Department of Clinical Sciences, Faculty of Medicine, Lund University, Lund, Sweden
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Veldhuizen RAW, Zuo YY, Petersen NO, Lewis JF, Possmayer F. The COVID-19 pandemic: a target for surfactant therapy? Expert Rev Respir Med 2020; 15:597-608. [PMID: 33331197 DOI: 10.1080/17476348.2021.1865809] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
INTRODUCTION The dramatic impact of COVID-19 on humans worldwide has initiated an extraordinary search for effective treatment approaches. One of these is the administration of exogenous surfactant, which is being tested in ongoing clinical trials. AREAS COVERED Exogenous surfactant is a life-saving treatment for premature infants with neonatal respiratory distress syndrome. This treatment has also been tested for acute respiratory distress syndrome (ARDS) with limited success possibly due to the complexity of that syndrome. The 60-year history of successes and failures associated with surfactant therapy distinguishes it from many other treatments currently being tested for COVID-19 and provides the opportunity to discuss the factors that may influence the success of this therapy. EXPERT OPINION Clinical data provide a strong rationale for using exogenous surfactant in COVID-19 patients. Success of this therapy may be influenced by the mechanical ventilation strategy, the timing of treatment, the doses delivered, the method of delivery and the preparations utilized. In addition, future development of enhanced preparations may improve this treatment approach. Overall, results from ongoing trials may not only provide data to indicate if this therapy is effective for COVID-19 patients, but also lead to further scientific understanding and improved treatment strategies.
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Affiliation(s)
- Ruud A W Veldhuizen
- Department of Physiology & Pharmacology, Western University, London, Ontario, Canada.,Department of Medicine, Western University, London, Ontario, Canada
| | - Yi Y Zuo
- Department of Mechanical Engineering, University of Hawaii at Manon, Honolulu, Hawaii, USA.,Department of Pediatrics, University of Hawaii, Honolulu, Hawaii, USA
| | - Nils O Petersen
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada.,Department of Chemistry, Western University, London, Ontario, Canada
| | - James F Lewis
- Department of Physiology & Pharmacology, Western University, London, Ontario, Canada.,Department of Medicine, Western University, London, Ontario, Canada
| | - Fred Possmayer
- Department of Biochemistry, Western University, London, Ontario, Canada.,Department of Obstetrics/Gynaecology, Western University, London, Ontario, Canada
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A novel delivery system for supraglottic atomization allows increased lung deposition rates of pulmonary surfactant in newborn piglets. Pediatr Res 2020; 87:1019-1024. [PMID: 31785590 PMCID: PMC7224119 DOI: 10.1038/s41390-019-0696-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 10/21/2019] [Accepted: 11/18/2019] [Indexed: 11/09/2022]
Abstract
BACKGROUND Earlier attempts to deliver effective lung doses of surfactant by aerosolization were unsuccessful, mostly because of technical shortcomings. We aimed at quantifying the lung deposition of poractant alfa with a new supraglottic delivery system for surfactant atomization in an experimental neonatal model. METHODS The method involved six sedated 1-day-old piglets lying in the lateral decubitus, spontaneously breathing on nasal-mask continuous positive airway pressure (nCPAP). A pharyngeal cannula housing a multi-channel air-blasting atomization catheter was placed through the mouth with its tip above the glottis entrance. In all, 200 mg kg-1 of a 99mTc-surfactant mixture was atomized through the catheter synchronously with inspiration. Six intubated control piglets received an equal amount of intratracheally instilled 99mTc-surfactant mixture. The percentage of the 99mTc-surfactant mixture deposited in the lungs was estimated by scintigraphy. RESULTS Median (range) deposition in the lungs was 40% (24-68%) after atomization and 87% (55-95%) after instillation (p < 0.001). Overall, almost 80% of the deposited surfactant was in the dependent lung. Effective atomization time (atomizer on) was 28 (17-52) min, yielding an output rate of 0.1-0.2 mL min-1. CONCLUSIONS Without endotracheal intubation, in spontaneously breathing newborn piglets, this new supraglottic atomizer delivery system attained a median lung deposition of 40% of the nominal dose of surfactant.
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Recent Developments in mRNA-Based Protein Supplementation Therapy to Target Lung Diseases. Mol Ther 2019; 27:803-823. [PMID: 30905577 DOI: 10.1016/j.ymthe.2019.02.019] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/25/2019] [Accepted: 02/25/2019] [Indexed: 12/20/2022] Open
Abstract
Protein supplementation therapy using in vitro-transcribed (IVT) mRNA for genetic diseases contains huge potential as a new class of therapy. From the early ages of synthetic mRNA discovery, a great number of studies showed the versatile use of IVT mRNA as a novel approach to supplement faulty or absent protein and also as a vaccine. Many modifications have been made to produce high expressions of mRNA causing less immunogenicity and more stability. Recent advancements in the in vivo lung delivery of mRNA complexed with various carriers encouraged the whole mRNA community to tackle various genetic lung diseases. This review gives a comprehensive overview of cells associated with various lung diseases and recent advancements in mRNA-based protein replacement therapy. This review also covers a brief summary of developments in mRNA modifications and nanocarriers toward clinical translation.
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Efficacy, Safety, and Usability of Remifentanil as Premedication for INSURE in Preterm Neonates. CHILDREN-BASEL 2018; 5:children5050063. [PMID: 29789465 PMCID: PMC5977045 DOI: 10.3390/children5050063] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 05/15/2018] [Accepted: 05/19/2018] [Indexed: 01/06/2023]
Abstract
Background: We previously reported a 67% extubation failure with INSURE (Intubation, Surfactant, Extubation) using morphine as analgosedative premedication. Remifentanil, a rapid- and short-acting narcotic, might be ideal for INSURE, but efficacy and safety data for this indication are limited. Objectives: To assess whether remifentanil premedication increases extubation success rates compared with morphine, and to evaluate remifentanil's safety and usability in a teaching hospital context. Methods: Retrospective review of remifentanil orders for premedication, at a large teaching hospital neonatal intensive care unit (NICU). We compared INSURE failure rates (needing invasive ventilation after INSURE) with prior morphine-associated rates. Additionally, we surveyed NICU staff to identify usability and logistic issues with remifentanil. Results: 73 remifentanil doses were administered to 62 neonates (mean 31.6 ± 3.8 weeks' gestation). Extubation was successful in 88%, vs. 33% with morphine premedication (p < 0.001). Significant adverse events included chest wall rigidity (4%), one case of cardiopulmonary resuscitation (CPR) post-surfactant, naloxone reversal (5%), and notable transient desaturation (34%). Among 137 completed surveys, 57% indicated concerns, including delayed drug availability (median 1.1 h after order), rapid desaturations narrowing intubation timeframes and hindering trainee involvement, and difficulty with bag-mask ventilation after unsuccessful intubation attempts. Accordingly, 33% of ultimate intubators were attending neonatologists, versus 16% trainees. Conclusions: Remifentanil premedication was superior to morphine in allowing successful extubation, despite occasional chest wall rigidity and unfavorable conditions for trainees. We recommend direct supervision and INSURE protocols aimed at ensuring rapid intubation.
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Abman SH, Bancalari E, Jobe A. The Evolution of Bronchopulmonary Dysplasia after 50 Years. Am J Respir Crit Care Med 2017; 195:421-424. [PMID: 28199157 DOI: 10.1164/rccm.201611-2386ed] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Steven H Abman
- 1 Department of Pediatrics University of Colorado Denver Anschutz Medical Center Aurora, Colorado
| | - Eduardo Bancalari
- 2 Department of Pediatrics University of Miami Miller School of Medicine Miami, Florida and
| | - Alan Jobe
- 3 Cincinnati Children's Medical Center University of Cincinnati School of Medicine Cincinnati, Ohio
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Carta G, Murru E, Banni S, Manca C. Palmitic Acid: Physiological Role, Metabolism and Nutritional Implications. Front Physiol 2017; 8:902. [PMID: 29167646 PMCID: PMC5682332 DOI: 10.3389/fphys.2017.00902] [Citation(s) in RCA: 370] [Impact Index Per Article: 52.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Accepted: 10/24/2017] [Indexed: 12/19/2022] Open
Abstract
Palmitic acid (PA) has been for long time negatively depicted for its putative detrimental health effects, shadowing its multiple crucial physiological activities. PA is the most common saturated fatty acid accounting for 20–30% of total fatty acids in the human body and can be provided in the diet or synthesized endogenously via de novo lipogenesis (DNL). PA tissue content seems to be controlled around a well-defined concentration, and changes in its intake do not influence significantly its tissue concentration because the exogenous source is counterbalanced by PA endogenous biosynthesis. Particular physiopathological conditions and nutritional factors may strongly induce DNL, resulting in increased tissue content of PA and disrupted homeostatic control of its tissue concentration. The tight homeostatic control of PA tissue concentration is likely related to its fundamental physiological role to guarantee membrane physical properties but also to consent protein palmitoylation, palmitoylethanolamide (PEA) biosynthesis, and in the lung an efficient surfactant activity. In order to maintain membrane phospholipids (PL) balance may be crucial an optimal intake of PA in a certain ratio with unsaturated fatty acids, especially PUFAs of both n-6 and n-3 families. However, in presence of other factors such as positive energy balance, excessive intake of carbohydrates (in particular mono and disaccharides), and a sedentary lifestyle, the mechanisms to maintain a steady state of PA concentration may be disrupted leading to an over accumulation of tissue PA resulting in dyslipidemia, hyperglycemia, increased ectopic fat accumulation and increased inflammatory tone via toll-like receptor 4. It is therefore likely that the controversial data on the association of dietary PA with detrimental health effects, may be related to an excessive imbalance of dietary PA/PUFA ratio which, in certain physiopathological conditions, and in presence of an enhanced DNL, may further accelerate these deleterious effects.
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Affiliation(s)
- Gianfranca Carta
- Dipartimento Scienze Biomediche, Università degli studi di Cagliari, Cagliari, Italy
| | - Elisabetta Murru
- Dipartimento Scienze Biomediche, Università degli studi di Cagliari, Cagliari, Italy
| | - Sebastiano Banni
- Dipartimento Scienze Biomediche, Università degli studi di Cagliari, Cagliari, Italy
| | - Claudia Manca
- Dipartimento Scienze Biomediche, Università degli studi di Cagliari, Cagliari, Italy
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12
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Abstract
The increased survival of very preterm infants is generally attributed to improved care strategies. This review develops the thesis that the features of abnormal pregnancies responsible for very preterm deliveries also provide an explanation of why very preterm infants often survive. A normal fetus born at 24 weeks is very unlikely to survive. However, pregnancies that result in deliveries at 24 weeks are generally highly abnormal, and may have been so for prolonged periods prior to the preterm deliveries. Inflammatory or vascular developmental abnormalities resulting in very preterm birth can alter fetal development in such a way that organ system maturation is induced. This is supported clinically by the relative lack of very preterm infants with respiratory distress syndrome. Interventions such as antenatal corticosteroid treatment and postnatal surfactant treatment for infants with respiratory distress syndrome and gentle ventilation strategies maximize fetal adaptations to the abnormal fetal environment and improve outcomes.
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Affiliation(s)
- Alan H Jobe
- Division of Neonatology/Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio 45229-3039, USA.
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Abstract
Mucus is tenacious. It sticks to most particles, preventing their penetration to the epithelial surface. Multiple low-affinity hydrophobic interactions play a major role in these adhesive interactions. Mucus gel is also shear-thinning, making it an excellent lubricant that ensures an unstirred layer of mucus remains adherent to the epithelial surface. Thus nanoparticles (NP) must diffuse readily through the unstirred adherent layer if they are to contact epithelial cells efficiently. This article reviews some of the physiological and biochemical properties that form the mucus barrier. Capsid viruses can diffuse through mucus as rapidly as through water and thereby penetrate to the epithelium even though they have to diffuse 'upstream' through mucus that is being continuously secreted. These viruses are smaller than the mucus mesh spacing, and have surfaces that do not stick to mucus. They form a useful model for developing NP for mucosal drug delivery.
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Wagner A, Vorauer-Uhl K, Katinger H. Nebulization of Liposomal rh-Cu/Zn–SOD with a Novel Vibrating Membrane Nebulizer. J Liposome Res 2008; 16:113-25. [PMID: 16753966 DOI: 10.1080/08982100600680733] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Liposomes are potential drug carriers for pulmonary drug delivery: They can be prepared from phospholipids, which are endogenous to the respiratory tract as a component of pulmonary surfactant, and at an appropriate dose liposomes do not pose a toxicological risk to this organ. Among the various categories of drug that benefit from liposomal entrapment is the anti-inflammatory enzyme superoxide dismutase, thus prolonging its biological half-life. The delivery of liposomes by nebulization is hampered by stability problems, like physical and chemical changes that may lead to chemical degradation and leakage of the encapsulated drug. Here we present data of liposomes aerosolized with a novel electronic nebulizer based on a vibrating membrane technology (PARI eFlow), which amends drawbacks like liposomes degradation and product release. The data acquisition included aerosol properties such as aerodynamic particle size, nebulization efficiency, and liposome leakage upon nebulization. In conclusion, this study shows the ability of the PARI eFlow to nebulize high amounts of liposomal recombinant human superoxide dismutase with reduced vesicle disruption tested in an enclosing experimental protocol.
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Affiliation(s)
- A Wagner
- Polymun Scientific, Immunbiologische Forschung GmbH, Vienna, Austria.
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Cirera S, Nygård AB, Jensen HE, Skovgaard K, Boye M, Fredholm M. Molecular characterization of the porcine surfactant, pulmonary-associated protein C gene. Genomics 2006; 88:659-68. [PMID: 16769199 DOI: 10.1016/j.ygeno.2006.04.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2006] [Revised: 04/24/2006] [Accepted: 04/26/2006] [Indexed: 11/26/2022]
Abstract
The surfactant, pulmonary-associated protein C (SFTPC) is a peptide secreted by the alveolar type II pneumocytes of the lung. We have characterized the porcine SFTPC gene at genomic, transcriptional, and protein levels. The porcine SFTPC is a single-copy gene on pig chromosome 14. Two transcripts were found in a newborn pig lung cDNA library: a full-length clone and a clone missing exon 5. cDNA sequence comparison revealed four synonymous and two nonsynonymous substitutions and in-frame insertions at the beginning of exon 5. Comparison of the SFTPC coding region between several mammals showed high levels of conservation. Northern blot studies showed lung-specific expression of the full-length SFTPC transcript, appearing in 50-day-old fetus and increasing during lung development. Both SFTPC transcripts were detected mainly in lung by real-time RT-PCR and they were significantly down-regulated in necrotic lungs of pigs infected with Actinobacillus pleuropneumoniae. Additionally, the protein levels were also decreased or absent in the necrotic tissue.
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Affiliation(s)
- S Cirera
- Department of Animal and Veterinary Basic Sciences, Division of Genetics, The Royal Veterinary and Agricultural University, 1870 Frederiksberg C, Denmark.
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KURASHIMA K, FUJIMURA M, TSUJIURA M, MATSUDA T. Effect of surfactant inhalation on allergic bronchoconstriction in guinea pigs. Clin Exp Allergy 2006. [DOI: 10.1111/j.1365-2222.1997.tb00713.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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LIU M, WANG L, LI E, ENHORNING G. Pulmonary surfactant given prophylactically alleviates an asthma attack in guinea-pigs. Clin Exp Allergy 2006. [DOI: 10.1111/j.1365-2222.1996.tb00091.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Clark H, Clark LS. The genetics of neonatal respiratory disease. Semin Fetal Neonatal Med 2005; 10:271-82. [PMID: 15927881 DOI: 10.1016/j.siny.2005.02.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/10/2005] [Indexed: 11/23/2022]
Abstract
This chapter reviews some of the genetic predispositions that may govern the presence or severity of neonatal respiratory disorders. Respiratory disease is common in the neonatal period, and genetic factors have been implicated in some rare and common respiratory diseases. Among the most common respiratory diseases are respiratory distress syndrome of the newborn and transient tachypnoea of the newborn, whereas less common ones are cystic fibrosis, congenital alveolar proteinosis and primary ciliary dyskinesias. A common complication of neonatal respiratory distress syndrome is bronchopulmonary dysplasia or neonatal chronic lung disease. This review examines the evidence linking known genetic contributions to these diseases. The value and success of neonatal screening for cystic fibrosis is reviewed, and the recently characterised contribution of polymorphisms and mutations in the surfactant protein genes to neonatal respiratory disease is evaluated. The evidence that known variability in the expression of surfactant protein genes may contribute to the risk of development of neonatal chronic lung disease or bronchopulmonary dysplasia is examined.
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Affiliation(s)
- Howard Clark
- MRC Immunochemistry Unit, Department of Biochemistry, University of Oxford, South Parks Road, Headington, Oxford OX1 3QU, UK.
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O'Brodovich H. Airspace fluid clearance in the normal and edematous newborn lung: cardiogenic pulmonary edema fluid alters the clearance of airspace fluid. Pediatr Pulmonol 2004; 26:121-2. [PMID: 15029623 DOI: 10.1002/ppul.70077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Affiliation(s)
- Hugh O'Brodovich
- Department of Paediatrics, Hospital for Sick Children, University of Toronto, Canada.
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Affiliation(s)
- Hugh O'Brodovich
- Department of Paediatrics, Hospital for Sick Children, University of Toronto, Canada.
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Wu YZ, Medjane S, Chabot S, Kubrusly FS, Raw I, Chignard M, Touqui L. Surfactant protein-A and phosphatidylglycerol suppress type IIA phospholipase A2 synthesis via nuclear factor-kappaB. Am J Respir Crit Care Med 2003; 168:692-9. [PMID: 12882758 DOI: 10.1164/rccm.200304-467oc] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
We previously showed that surfactant inhibits the synthesis of type IIA secretory phospholipase A2 (sPLA2-IIA) by alveolar macrophages. These cells have been identified as the main source of this enzyme in an animal model of acute lung injury. The aim of the present study was to identify the surfactant components involved in the inhibition of sPLA2-IIA expression in alveolar macrophages and the signaling pathways that mediate this inhibition. Our results show that various surfactant preparations can inhibit sPLA2-IIA expression in endotoxin-stimulated alveolar macrophages. Both the surfactant protein (SP)-A and the surfactant phospholipid fraction inhibit this expression. The surfactant phospholipid dioleylphosphatidylglycerol (DOPG) abolishes sPLA2-IIA expression, whereas dipalmitoylphosphatidylcholine does not. Chromatographic analysis and confocal microscopy revealed that phosphatidylglycerol was rapidly incorporated and metabolized by alveolar macrophages and that its metabolites accumulate in the cytosol. Nuclear factor-kappaB (NF-kappaB) modulates sPLA2-IIA expression in endotoxin-activated alveolar macrophages, and surfactant preparations, surfactant phospholipid fraction, SP-A, and DOPG indeed suppressed NF-kappaB activation. In summary, our results show that SP-A and DOPG play a role in the surfactant-mediated inhibition of sPLA2-IIA expression in alveolar macrophages and that this inhibition occurs via a downregulation of NF-kappaB activation.
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Affiliation(s)
- Yong-Zheng Wu
- Unité de Défense Innée et Inflammation/INSERM E336, Institut Pasteur, 75015 Paris, France
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Petkova V, Platikanov D, Nedyalkov M. Phospholipid black foam films: dynamic contact angles and gas permeability of DMPC+DMPG black films. Adv Colloid Interface Sci 2003; 104:37-51. [PMID: 12818489 DOI: 10.1016/s0001-8686(03)00035-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The behavior of black foam films from aqueous dispersions of dimyristoylphosphatidyl-choline (DMPC) with addition of the soluble phospholipid dimyristoylphosphatidylglycerol (DMPG) has been studied in dynamic conditions. The dynamic contact angles theta and the gas permeability coefficient K have been measured using the diminishing bubble method. The DMPC vesicle suspension in water is obtained through sonication and DMPG is dissolved in it. Two solutions with different NaCl concentrations (0.1 M and 0.5 M) have been studied. The behavior of the dynamic contact angles is very different for DMPC black films with, and without DMPG, respectively. They follow very different time dependence during spontaneous or forced variations of the bubble size. The gas permeability coefficient is significantly reduced by the DMPG addition. The NaCl concentration also influences this specific behavior. It seems that the electrically charged DMPG anions, which determine a significant electrostatic disjoining pressure, play an important role for this specific behavior. The results are discussed in connection with data regarding the thickness and structure of these black foam films. Films from DMPC+DMPG solutions in ethanol plus water mixed solvent have been studied as well, but no quantitative results could be obtained.
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Affiliation(s)
- V Petkova
- Department of Physical Chemistry, University of Sofia, Boulevard James Bourchier 1, Sofia 1126, Bulgaria
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Amato M, Petit K, Fiore HH, Doyle CA, Frantz ID, Nielsen HC. Effect of exogenous surfactant on the development of surfactant synthesis in premature rabbit lung. Pediatr Res 2003; 53:671-8. [PMID: 12612208 DOI: 10.1203/01.pdr.0000054655.95452.06] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Surfactant replacement is an effective therapy for neonatal respiratory distress syndrome. Full recovery from respiratory distress syndrome requires development of endogenous surfactant synthesis and metabolism. The influence of exogenous surfactant on the development of surfactant synthesis in premature lungs is not known. We hypothesized that different exogenous surfactants have different effects on the development of endogenous surfactant production in the premature lung. We treated organ cultures of d 25 fetal rabbit lung for 3 d with 100 mg/kg body weight of natural rabbit surfactant, Survanta, and Exosurf and measured their effects on the development of surfactant synthesis. Additional experiments tested how these surfactants and Curosurf affected surfactant protein (SP) SP-A, SP-B, and SP-C mRNA expression. Surfactant synthesis was measured as the incorporation of 3H-choline and 14C-glycerol into disaturated phosphatidylcholine recovered from lamellar bodies. Randomized-block ANOVA showed significant differences among treatments for incorporation of both labels (p < 0.01), with natural rabbit surfactant less than control, Survanta greater than control, and Exosurf unchanged. Additional experiments with natural rabbit surfactant alone showed no significant effects in doses up to 1000 mg/kg. Survanta stimulated disaturated phosphatidylcholine synthesis (173 +/- 41% of control; p = 0.01), increased total lamellar body disaturated phosphatidylcholine by 22% (p < 0.05), and increased 14C-disat-PC specific activity by 35% (p < 0.05). The response to Survanta was dose-dependent up to 1000 mg/kg. Survanta did not affect surfactant release. No surfactant altered the expression of mRNA for SP-A, SP-B, or SP-C. We conclude that surfactant replacement therapy can enhance the maturation of surfactant synthesis, but this potential benefit differs with different surfactant preparations.
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Janssen DJMT, Tibboel D, Carnielli VP, van Emmen E, Luijendijk IHT, Darcos Wattimena JL, Zimmermann LJI. Surfactant phosphatidylcholine pool size in human neonates with congenital diaphragmatic hernia requiring ECMO. J Pediatr 2003; 142:247-52. [PMID: 12640370 DOI: 10.1067/mpd.2003.94] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE We measured surfactant phosphatidylcholine (PC) pool size and half-life in human congenital diaphragmatic hernia (CDH) patients who required extracorporeal membrane oxygenation (ECMO). Study design Surfactant PC pool size and half-life were measured by endotracheal administration of deuterium-labeled dipalmitoylphosphatidylcholine in 8 neonates with CDH on ECMO (CDH-ECMO), in 7 neonates with meconium aspiration syndrome on ECMO (MAS-ECMO), and in 6 ventilated infants (NON-ECMO). RESULTS Lung PC pool size in the CDH-ECMO group was 73 +/- 17 mg/kg (mean +/- SEM), which was not significantly different from the MAS-ECMO (50 +/- 18 mg/kg) and the NON-ECMO group (69 +/- 38 mg/kg). Surfactant PC concentration in tracheal aspirates was not different between groups (~6 mg/mL). However, the percentage of palmitic acid in surfactant PC was significantly lower in the MAS-ECMO (56.3%) and the NON-ECMO (55.8%) group compared with the CDH-ECMO (67.6%) group. Surfactant PC half-life (~24 hours) was not different between the groups. A correlation was found between the surfactant PC half-life and the duration of ECMO. CONCLUSIONS These data show no decreased surfactant PC pool size in high risk CDH patients who require ECMO. A shorter half-life of surfactant PC, indicating a faster turnover, may result in a faster improvement of the pulmonary condition during ECMO.
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Affiliation(s)
- Daphne J M T Janssen
- Department of Pediatrics/Neonatology, Sophia Children's Hospital/Erasmus University Rotterdam, The Netherlands
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Trials on Surfactant Replacement Therapy in Patients with ARDS. Intensive Care Med 2003. [DOI: 10.1007/978-1-4757-5548-0_31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Merchak A, Janssen DJ, Bohlin K, Patterson BW, Zimmermann LJ, Carnielli VP, Hamvas A. Endogenous pulmonary surfactant metabolism is not affected by mode of ventilation in premature infants with respiratory distress syndrome. J Pediatr 2002; 140:693-8. [PMID: 12072872 DOI: 10.1067/mpd.2002.124320] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To determine if high frequency oscillatory ventilation (HFOV) decreases surfactant production in premature infants with respiratory distress syndrome (RDS). STUDY DESIGN We randomized 19 infants <28 weeks of gestation to either HFOV (n = 8) or conventional ventilation (CV, n = 11) at 24 hours of life. After a 24-hour continuous infusion of uniformly labeled carbon 13 glucose (U-(13)C(6)) glucose, we measured (13)C enrichment in surfactant phosphatidylcholine (PC) in tracheal aspirate samples using gas chromatography/mass spectrometry. We calculated the fractional synthetic rate (FSR) of surfactant PC from labeled glucose and its half-life of clearance (T(1/2)). RESULTS FSR did not differ between groups (4.7% +/- 2.7%/day CV vs 4.2% +/- 3.1%/day HFOV, P =.7). T(1/2) was 79 +/- 18 hours in the CV group and 76 +/- 23 hours in the HFOV group (P =.7). Neither degree of ventilatory support nor supplemental oxygen exposure correlated with surfactant metabolic indices. Three of 4 infants who died from RDS within the first month of life had a shorter T(1/2) than 14 of 15 infants who survived. CONCLUSION Surfactant metabolism is similar in preterm infants ventilated with HFOV and CV. Shortened surfactant half-life may characterize a subset of preterm infants with lethal RDS.
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Affiliation(s)
- Assaad Merchak
- the Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, and St. Louis Children's Hospital, St Louis, Missouri 63110, USA
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Robinson TW, Roberts AM. Effects of exogenous surfactant on gas exchange and compliance in rabbits after meconium aspiration. Pediatr Pulmonol 2002; 33:117-23. [PMID: 11802248 DOI: 10.1002/ppul.10056] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Success in using adjunctive surfactant therapy for meconium aspiration has been inconsistent. We tested the hypothesis that the ability of exogenous surfactant to improve gas exchange and pulmonary compliance after meconium aspiration is related to the method of surfactant administration. In anesthetized rabbits (2.4 +/- 0.16 kg body weight), an endotracheal tube (ETT) was placed in the lower trachea, and the lungs were ventilated mechanically. After a control period, filtered meconium (3-5 mL/kg) was instilled through the ETT. Group 1 (n = 5) was not given surfactant. Thirty minutes after meconium instillation, group 2 (n = 5) was given a bolus of bovine surfactant (Beractant, 4 mL/kg) through the ETT, and group 3 (n = 5) was given an infusion of Beractant (4 mL/kg for 1 hr) through the side-port of the ETT. Thirty minutes after meconium instillation, tracheal pressure increased by 8 +/- 1 cm H(2)O (mean +/- SEM), dynamic compliance decreased by 0.36 +/- 0.07 mL/cm H(2)O/kg, arterial PO(2) (PaO(2)) decreased by 49 +/- 6.0 mmHg, arterial PCO(2) (PaCO(2)) increased by 12 +/- 2.4 mmHg, and arterial pH (pHa) decreased by 0.09 +/- 0.02. After 3 hr of exposure to meconium, tracheal pressure was significantly (P < 0.001) lower in group 3 compared to groups 1 or 2. PaO(2) remained below baseline in all groups. Group 3 had a significantly (P = 0.001) higher dynamic compliance than groups 1 or 2. Likewise, static compliance was higher for group 3 compared to groups 1 or 2, with the greatest difference at low lung volume. Mean arterial blood pressure, pulse rate, PaCO(2), and pHa were not significantly different between groups. These results suggest that continuous infusion of exogenous surfactant is more effective than bolus administration in improving pulmonary function after meconium aspiration.
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Affiliation(s)
- Tonya W Robinson
- Division of Neonatal Medicine, Department of Pediatrics, University of Louisville School of Medicine, Louisville, Kentucky 40202-3830, USA.
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Abstract
Surfactant is a metabolically active assembly of phospholipids and surfactant-specific proteins that is essential for normal lung mechanics. The surfactant proteins SP-A and SP-D also have important innate host defense functions. Surfactant metabolism in the developing lung differs from the adult lung by having slower kinetics of secretion with a longer half-life and more efficient recycling. Ventilation styles that injure the lung also result in altered surfactant function.
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Affiliation(s)
- A H Jobe
- Division of Pulmonary Biology, Children's Hospital Medical Center, Cincinnati, Ohio, USA.
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Abstract
Surfactant administration has proven remarkably effective in the prevention and treatment of infantile respiratory distress syndrome (IRDS) and may also be beneficial in other forms of acute lung injury. Several surfactant products are available commercially along with others in various phases of development and clinical trials. While all of these products share an ability to lower surface tension in vitro, there are substantial compositional differences that appear to affect their in vivo efficacy. At present, the 'modified natural' surfactants containing the hydrophobic surfactant proteins SP-B and SP-C appear most effective. Calfactant may have a particular advantage because of its relatively high content of SP-B and its lack of contamination with non-surfactant lipids and proteins.
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Affiliation(s)
- D Willson
- Division of Pediatric Critical Care, Pediatric ICU, Children's Medical Center, University of Virginia Health Sciences System, Charlottesville 22908, USA
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Petkoval V, Nedyalkov M, Benattar JJ. Freestanding black films of phospholipids and phospholipid with proteins. Colloids Surf A Physicochem Eng Asp 2001. [DOI: 10.1016/s0927-7757(01)00660-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Warnecke G, Strüber M, Fraud S, Hohlfeld JM, Haverich A. Combined exogenous surfactant and inhaled nitric oxide therapy for lung ischemia-reperfusion injury in minipigs. Transplantation 2001; 71:1238-44. [PMID: 11397956 DOI: 10.1097/00007890-200105150-00010] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The combined application of exogenous surfactant and inhaled nitric oxide was evaluated for prevention of ischemia-reperfusion injury of the lung. METHODS Left lungs were selectively perfused in 18 minipigs in situ with cold preservation solution. After 90 min of warm ischemia, the lungs were reperfused and the right pulmonary artery and bronchus were ligated (control group, n=6). Exogenous surfactant was instilled via bronchoscopy during ischemia (surfactant group, n=6). In a third group, surfactant was applied, followed by administration of inhaled nitric oxide (surfactant+NO group, n=6). Hemodynamic and respiratory parameters were recorded for 7 hr, and bronchoalveolar lavage fluid (BALF) was obtained before and after reperfusion for measurement of surface tension, small aggregate/large aggregate ratio, protein and phospholipid contents, and a differential cell count. RESULTS Control group animals survived for 3.7+/-1.4 hr. In both surfactant-treated groups, five out of six animals survived the observation period (P<0.001). Dynamic compliance of the lung was decreased in control animals (P<0.001). In the surfactant+NO group, arterial PO2 was higher than in both other groups (P<0.001). BALF cell count and histology showed reduced neutrophil infiltration in surfactant+NO-treated lungs. Surface tension assessed in BALF with a pulsating bubble surfactometer was severely impaired in control animals (gammamin, 14.82+/-9.95 mN/m), but maintained in surfactant-treated (gammamin, 1.11+/-0.56 mN/m) and surfactant+NO-treated animals (gammamin, 3.90+/-2.35 mN/m, P=0.02). CONCLUSIONS Administration of exogenous surfactant in lung reperfusion injury results in improved lung compliance. The addition of inhaled NO improves arterial oxygenation and reduces neutrophil extravasation compared with surfactant treatment alone.
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Affiliation(s)
- G Warnecke
- Department of Thoracic and Cardiovascular Surgery, Hannover Medical School, Germany
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Gross CS, Simms PJ, Towne RW, Miller RE. Quantitative determination of dipalmitoylphosphatidylcholine and palmitic acid in porcine lung surfactants used in the treatment of respiratory distress syndrome. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2000; 744:407-13. [PMID: 10993530 DOI: 10.1016/s0378-4347(00)00276-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A high-performance liquid chromatography (HPLC) method was developed that can separate and quantify dipalmitoylphosphatidylcholine and its degradation product, palmitic acid from various phospholipids contained in a porcine lung surfactant used in the treatment of respiratory distress syndrome, which was recently approved for use by the FDA. The method used a C8 reversed-phase HPLC column with a (50:45:10) acetonitrile/methanol/acetic acid mobile phase, and refractive index detection. The active component of the lung surfactant, dipalmitoylphosphatidylcholine (DPPC) and palmitic acid (PA), could be quantified following a liquid-liquid extraction procedure along with an internal standard, dimyristoylphosphatidylcholine (DMPC). The assay was validated for linearity, accuracy, precision, reproducibility and ruggedness. Column stability was measured by performing the assay over time and monitoring the system suitability parameters. The extraction procedure has a 90% recovery and the assay is linear over a range of 5 microg/ml to 300 microg/ml. The assay is used to release commercial product and monitor stability of existing lots of material.
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Affiliation(s)
- C S Gross
- Biosource Technologies, Inc., Vacaville, CA 95688, USA
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35
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Ojeda MS, Gómez NN, Gil E, Scardapane L, Gimenez MS. Morphologic and biochemical changes in male rat lung after surgical and pharmacological castration. Braz J Med Biol Res 2000; 33:279-85. [PMID: 10719378 DOI: 10.1590/s0100-879x2000000300004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The morphology of the rat lung was studied by light microscopy in different situations: after surgical and pharmacological castration and after administration of testosterone to the castrated rat to determine if the androgen is required to maintain the normal morphology of the lung. We also determined the effect of flutamide on the phospholipid composition of both the surfactant and microsomes of the lung. Rats were separated into five groups: I - control non-castrated rats, II - castrated rats sacrificed 21 days after castration, III - castrated rats that received testosterone daily from day 2 to day 21 after castration, IV - castrated rats that received testosterone from day 15 to day 21 after castration, and V - control rats injected with flutamide for 7 days. The amount of different phospholipids in the surfactant and microsomes of the lung was measured in group I and V rats. At the light microscopy level, the surgical and pharmacological castration provoked alterations in the morphology of the lung, similar to that observed in human lung emphysema. The compositions of surfactant and microsomes of the lung were similar to those previously reported by us for the surgically castrated rats. These results indicate that androgens are necessary for the normal morphology as well as for some metabolic aspects of the lung.
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Affiliation(s)
- M S Ojeda
- Departamento de Química Biológica, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina
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Rider ED, Ikegami M, Pinkerton KE, Peake JL, Jobe AH. Lysosomes from rabbit type II cells catabolize surfactant lipids. Am J Physiol Lung Cell Mol Physiol 2000; 278:L68-74. [PMID: 10645892 DOI: 10.1152/ajplung.2000.278.1.l68] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The role of a lysosome fraction from rabbit type II cells in surfactant dipalmitoylphosphatidylcholine (DPPC) catabolism was investigated in vivo using radiolabeled DPPC and dihexadecylphosphatidylcholine (1, 2-dihexadecyl-sn-glycero-3-phosphocholine; DEPC), a phospholipase A(1)- and A(2)-resistant analog of DPPC. Freshly isolated type II cells were gently disrupted by shearing, and lysosomes were isolated with Percoll density gradients (density range 1.0591-1.1457 g/ml). The lysosome fractions were relatively free of contaminating organelles as determined by electron microscopy and organelle marker enzymes. After intratracheal injection of rabbits with [(3)H]DPPC and [(14)C]DEPC associated with a trace amount of natural rabbit surfactant, the degradation-resistant DEPC accumulated 16-fold compared with DPPC in lysosome fractions at 15 h. Lysosomes can be isolated from freshly isolated type II cells, and lysosomes from type II cells are the primary catabolic organelle for alveolar surfactant DPPC following reuptake by type II cells in vivo.
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Affiliation(s)
- E D Rider
- Department of Pediatrics, University of Arizona and Steele Memorial Children's Research Center, Tucson, Arizona 85724, USA
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Abstract
A number of advances in the treatment of infants and children with respiratory failure have been investigated in the laboratory with translation to clinical practice. Investigators have recognized that application of high ventilating pressures and failure to apply adequate levels of positive end-expiratory pressure (PEEP) can inflict injury to the already failing lung. Other interventions such as prone positioning and application of new ventilating strategies such as proportional assist ventilation (PAV), inverse ratio ventilation (IRV), high frequency ventilation, liquid ventilation, and intratracheal pulmonary ventilation (ITPV), continue to be developed and explored. Administration of inhaled nitric oxide (iNO) may improve pulmonary physiology and gas exchange in patients with respiratory insufficiency. Finally, the technique of extracorporeal life support (ECLS) is being simplified and refined. This report summarizes the status of these advances and describes the basic science and clinical research that brought them to clinical application.
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Affiliation(s)
- R B Hirschl
- Department of Surgery, University of Michigan, Ann Arbor, USA
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da Costa DE, Pai MG, Al Khusaiby SM. Comparative trial of artificial and natural surfactants in the treatment of respiratory distress syndrome of prematurity: experiences in a developing country. Pediatr Pulmonol 1999; 27:312-7. [PMID: 10344709 DOI: 10.1002/(sici)1099-0496(199905)27:5<312::aid-ppul3>3.0.co;2-n] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We conducted a randomized clinical trial to compare the effects of a synthetic (Exosurf) and natural (Survanta) surfactant in infants with neonatal respiratory distress syndrome. Eighty-nine patients were randomly allocated to receive one of the two surfactants. Primary outcome variables were the acute and long-term effects of the surfactant preparations, i.e., ventilatory requirements at 24 h of age as judged by the oxygenation index (OI), and the combined incidence of chronic lung disease or death at 28 days. The OIs in the Exosurf and Survanta groups at 24 h were the same (10.1 and 7, respectively; P > 0.05). The magnitude and rapidity of response, however, were greater for Survanta than for Exosurf. When arterial/alveolar oxygen tension ratios (a/A) were compared, the Exosurf group had a significantly worse a/A ratio at 24 h than the Survanta group (0.21 Exosurf vs. 0.37 Survanta; P < 0.05). The long-term outcome as judged by the combined incidence of death or chronic lung disease was not different in the two groups (18.6% Exosurf vs. 15.2% Survanta; P > 0.05). When the complications of prematurity were compared, there were no statistically significant differences between the two groups. We conclude that both preparations are reasonable choices for the treatment of respiratory distress syndrome of prematurity.
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Affiliation(s)
- D E da Costa
- Division of Neonatology, Royal Hospital, Sultanate of Oman
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Abstract
Surfactant therapy is given routinely to premature newborns with respiratory failure. However, alterations in surfactants have been shown to be a significant factor in some forms of respiratory failure in newborns in animal models of lung injury. To investigate whether antioxidant supplementation might help to protect exogenous surfactant from damage by oxygen free radicals, we examined the influence of vitamin E in combination with surfactant on superoxide production as estimated by the nitroblue tetrazolium reduction test, and measured surfactant peroxidation with a new colorimetric method with or without addition of superoxide dismutase (SOD) or vitamin E. Our results showed that surfactant interacts with free radicals; surfactant reduced superoxide production by neutrophils and was peroxidized when incubated with resting and with stimulated cells. Vitamin E supplementation decreased superoxide radical production and in a dose-dependent manner decreased surfactant peroxidation. The decrease in lipid peroxidation by SOD was not significant. These findings suggest that phagocytes induce lipid peroxidation of lung surfactant, a reaction that might be prevented by antioxidants.
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Affiliation(s)
- R K Bouhafs
- Department of Immunology, Microbiology, Pathology, and Infectious Diseases, Huddinge Hospital, Karolinska Institute, Sweden
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Abstract
BACKGROUND Acute respiratory distress syndrome (ARDS) develops in association with many serious medical disorders. Mortality is at least 40%, and there is no specific therapy. A massive influx of activated neutrophils, which damage pulmonary vascular endothelium and alveolar epithelium, leads to alveolar oedema and pulmonary surfactant dysfunction. In-vitro studies show that neutrophil elastase can cleave surfactant-specific proteins and impair surfactant function. If this happens in vivo in ARDS, the response to surfactant therapy will be limited. METHODS Samples of pulmonary surfactant were obtained from the lungs of 18 patients with ARDS and six healthy controls by bronchoalveolar lavage. We separated proteins in these samples according to molecular weight by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). We then used western blotting with monoclonal antibody E8 to detect the major surfactant-specific protein A (SP-A). FINDINGS By contrast with controls, 14 of 18 patients had evidence of in-vivo damage to SP-A that resembled damage caused to SP-A when it is cleaved by neutrophil elastase. Controls showed a single band of normal dimers at 66 kDa, whereas 14 of 18 patients showed multiple bands at 66 kDa, 55 kDA, and 30-36 kDa, and six showed additional bands at 36-40 kDa. INTERPRETATION Direct damage to surfactant-specific proteins occurs in lungs of patients with ARDS, probably by proteolysis. Trials of protein-containing therapeutic surfactant are in progress in ARDS, and our results indicate that the frequent failure to maintain response may result from continuing damage to surfactant by products of activated neutrophils. A combination of surfactant and antiprotease therapy may improve therapeutic prospects.
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Affiliation(s)
- C S Baker
- Cell Biology Unit, National Heart and Lung Institute, Imperial College School of Medicine, London, UK
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Abstract
Surfactant therapy is an established part of routine clinical management of babies with respiratory distress syndrome. An initial dose of about 100 mg/kg is usually needed to compensate for the well documented deficiency of alveolar surfactant in these babies, and repeated treatment is required in many cases. Recent experimental and clinical data indicate that large doses of exogenous surfactant may be beneficial also in conditions characterized by inactivation of surfactant, caused by, for example, aspiration of meconium, infection, or disturbed alveolar permeability with leakage of plasma proteins into the airspaces. The acute response to surfactant therapy depends on the quality of the exogenous material (modified natural surfactants are generally more effective than protein-free synthetic surfactants), timing of treatment in relation to the clinical course (treatment at an early stage of the disease is better than late treatment, and may reduce the subsequent need for mechanical ventilation), and mode of delivery (rapid instillation via a tracheal tube leads to more uniform distribution and is more effective than slow airway infusion). Treatment with aerosolized surfactant improves lung function in animal models of surfactant deficiency or depletion, but is usually associated with large losses of the nebulized material in the delivery system. Furthermore, data from experiments on immature newborn lambs indicate that treatment response may depend on the mode of resuscitation at birth, and that manual ventilation with just a few large breaths may compromise the effect of subsequent surfactant therapy. The widespread clinical use of surfactant has reduced neonatal mortality and lowered costs for intensive care in developed countries. The hydrophobic surfactant proteins SP-B and SP-C are probably essential for optimal biophysical and physiological activity of exogenous surfactants isolated from mammalian lungs, and the dose-effectiveness (in part reflecting resistance to inactivation) can be further improved by enrichment with SP-A. The development of new artificial surfactant substitutes, based on synthetic analogues of the native surfactant proteins, is an important challenge for future research.
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Affiliation(s)
- B Robertson
- Division for Experimental Perinatal Pathology, Department of Woman and Child Health, Karolinska Hospital, Stockholm, Sweden.
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Helbich TH, Popow C, Dobner M, Wunderbaldinger P, Zekert M, Herold CJ. New-born infants with severe hyaline membrane disease: radiological evaluation during high frequency oscillatory versus conventional ventilation. Eur J Radiol 1998; 28:243-9. [PMID: 9881260 DOI: 10.1016/s0720-048x(97)00153-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
OBJECTIVE The aim of our study was to determine the impact of treatment with exogenous surfactant (ES) and high frequency oscillatory ventilation (HFOV) on the radiological appearance and clinical course of hyaline membrane disease (HMD) in new-born infants. MATERIALS AND METHODS New-born infants (18) (median weight, 1010 g) with severe HMD (stages 3.5 and 4) who were treated with ES and HFOV were matched by birth weight and severity of disease with 18 new-born infants treated with ES and conventional mechanical ventilation (CV). Chest radiograms taken on days 1, 2/3, 4/5, 7, 14 and 28 were analyzed to check for the severity of generalized parenchymal opacities (GPO), local opacifications, pulmonary interstitial emphysema (PIE), gross air leak, general and localized overinflation, bronchopulmonary dysplasia (BPD) and clinical variables such as survival rates, duration of mechanical ventilation, mean airway pressure and inspired oxygen concentration. RESULTS At 4 weeks of age, new-born infants treated by HFOV had less severe GPO (median degree 1.5 vs. 3), less PIE (1 vs. 7 patients) and fewer signs of BPD (median BPD degree 1.5 vs. 2.6). The incidence of pneumothorax and of local opacifications were similar in both groups. New-born infants on HFOV had a lower mortality rate (5 vs. 13), needed fewer days of mechanical ventilation (median 15 vs. 23 days) and lower inspiratory oxygen concentrations (median FiO2 0.38 vs. 0.64). CONCLUSION In new-born infants with HMD, treatment with ES and HFOV resulted in a favourable radiological and clinical outcome as compared to treatment with ES and CV.
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Affiliation(s)
- T H Helbich
- Department of Radiology, University of Vienna (AKH), Währinger Gürtel, Austria
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Kerr CL, Ito Y, Manwell SE, Veldhuizen RA, Yao LJ, McCaig LA, Lewis JF. Effects of surfactant distribution and ventilation strategies on efficacy of exogenous surfactant. J Appl Physiol (1985) 1998; 85:676-84. [PMID: 9688746 DOI: 10.1152/jappl.1998.85.2.676] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The effects of both surfactant distribution patterns and ventilation strategies utilized after surfactant administration were assessed in lung-injured adult rabbits. Animals received 50 mg/kg surfactant via intratracheal instillation in volumes of either 4 or 2 ml/kg. A subset of animals from each treatment group was euthanized for evaluation of the exogenous surfactant distribution. The remaining animals were randomized into one of three ventilatory groups: group 1 [tidal volume (VT) of 10 ml/kg with 5 cmH2O positive end-expiratory pressure (PEEP)]; group 2 (VT of 5 ml/kg with 5 cmH2O PEEP); or group 3 (VT of 5 ml/kg with 9 cmH2O PEEP). Animals were ventilated and monitored for 3 h. Distribution of the surfactant was more uniform when it was delivered in the 4 ml/kg volume. When the distribution of surfactant was less uniform, arterial PO2 values were greater in groups 2 and 3 compared with group 1. Oxygenation differences among the different ventilation strategies were less marked in animals with the more uniform distribution pattern of surfactant (4 ml/kg). In both surfactant treatment groups, a high mortality was observed with the ventilation strategy used for group 3. We conclude that the distribution of exogenous surfactant affects the response to different ventilatory strategies in this model of acute lung injury.
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Affiliation(s)
- C L Kerr
- Department of Physiology, St. Joseph's Health Centre, The University of Western Ontario, London, Ontario, Canada N6A 4V2.
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Abstract
The pathophysiology of neonatal meconium aspiration syndrome (MAS) is related to mechanical obstruction of the airways and to chemical pneumonitis. It has also been suggested that meconium causes inhibition of surfactant function. To assess its in vitro effect on surfactant function and morphology, we used a pulsating bubble surfactometer to measure the dynamic surface tension of meconium-surfactant mixtures and observed their electron microscopic structures. The mixtures were prepared by adding serial dilutions of human meconium to various concentrations of Surfactant-TA (Surfacten) that had been used for the prevention and treatment of neonatal respiratory distress syndrome. Inhibition of the surface tension-lowering properties of Surfactant-TA was caused by the addition of meconium and depended on the concentration of the surfactant; the inhibition could be overcome by increasing the surfactant concentration. When meconium was added to Surfactant-TA, the characteristic ultrastructural features of the latter, the loosely stacked layers, changed to a spherical lamellar structure and folded linear structures. These results suggest that meconium inhibits surfactant function by altering surfactant morphology. Our morphologic and functional findings support the new concept that surfactant inhibition may play a role in the pathophysiology of MAS.
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Affiliation(s)
- C W Bae
- Department of Pediatrics, Kyunghee University Hospital, Seoul, Korea
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Abstract
Surfactant replacement therapy has been shown to be an effective and often life-saving treatment for newborn infants with respiratory distress syndrome (RDS). This article provides the clinician with an update regarding the various other applications of surfactant replacement therapy, as well as issues related to surfactant administration for the preparations approved for use in pediatric patients.
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Affiliation(s)
- S A Dekowski
- Division of Neonatology, Northwestern University Medical School, Chicago, Illinois, USA
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Whitsett JA, Stahlman MT. Impact of advances in physiology, biochemistry, and molecular biology on pulmonary disease in neonates. Am J Respir Crit Care Med 1998; 157:S67-71. [PMID: 9563763 DOI: 10.1164/ajrccm.157.4.nhlb1-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
MESH Headings
- Animals
- Animals, Genetically Modified
- Humans
- Infant, Newborn
- Infant, Premature, Diseases/metabolism
- Infant, Premature, Diseases/physiopathology
- Infant, Premature, Diseases/therapy
- Lung Diseases/metabolism
- Lung Diseases/physiopathology
- Lung Diseases/therapy
- Pulmonary Surfactants/chemistry
- Pulmonary Surfactants/physiology
- Respiratory Distress Syndrome, Newborn/metabolism
- Respiratory Distress Syndrome, Newborn/physiopathology
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Affiliation(s)
- J A Whitsett
- Division of Neonatology, Children's Hospital Medical Center, Cincinnati, Ohio 45229-3039, USA.
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Phase Transition Temperature of Vesicles Determined by Surface Tension Measurements: A Fast Method. J Colloid Interface Sci 1998. [DOI: 10.1006/jcis.1997.5253] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Moya FR, Llanos AJ, Ríos AM, Riquelme RA, Moraga FA, Rubio LA, Salvo HD, Jacobs HC. Repeated doses of the perfluorocarbon FC-100 improve lung function of preterm lambs. Pediatr Res 1997; 42:893-8. [PMID: 9396575 DOI: 10.1203/00006450-199712000-00028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Intratracheal administration of a single dose of the perfluorocarbon FC-100 improves lung function in surfactant-deficient animals. In this study we compared the response to repeated doses of FC-100 (3 mL/kg 3% solution, n = 5) with that observed after administration of Exosurf (5 mL/kg, n = 5) to mechanically ventilated preterm lambs of 125 d of gestation. The initial dose of FC-100 rapidly increased arterial PO2, decreased arterial PCO2, and improved arterial pH. Also dynamic lung compliance markedly improved with this agent. Administration of an additional dose of FC-100 resulted in relatively similar changes, albeit of lesser magnitude than those observed with the initial dose. In contrast, Exosurf did not improve these variables even after three doses. All lambs treated with FC-100 survived the 6-h study period, whereas one of the five Exosurf-treated lambs survived (p < 0.05). Mean arterial blood pressure and heart rate decreased in those lambs that received FC-100, but not in surviving lambs that received Exosurf. Our data demonstrate that repeated intratracheal administration of the perfluorocarbon FC-100 improves lung function and survival of surfactant-deficient lambs better than the synthetic surfactant Exosurf. We speculate that tensio-active agents with properties different from surfactant, such as FC-100, might improve lung function in preterm neonates with diseases due to surfactant deficiency.
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Affiliation(s)
- F R Moya
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas 75235, USA
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Peruzzi WT, Franklin ML, Shapiro BA. New concepts and therapies of adult respiratory distress syndrome. J Cardiothorac Vasc Anesth 1997; 11:771-86. [PMID: 9327323 DOI: 10.1016/s1053-0770(97)90175-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- W T Peruzzi
- Department of Anesthesiology, Northwestern University Medical School, Chicago, IL, USA
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50
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Effects of lung surfactant specific protein SP-B and model SP-B peptide on lipid monolayers at the air-water interface. Colloids Surf A Physicochem Eng Asp 1997. [DOI: 10.1016/s0927-7757(96)03919-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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