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Geitner CM, Becher T, Frerichs I, Weiler N, Bates JHT, Wall WA. An approach to study recruitment/derecruitment dynamics in a patient-specific computational model of an injured human lung. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2023; 39:e3745. [PMID: 37403527 DOI: 10.1002/cnm.3745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 05/04/2023] [Accepted: 06/04/2023] [Indexed: 07/06/2023]
Abstract
We present a new approach for physics-based computational modeling of diseased human lungs. Our main object is the development of a model that takes the novel step of incorporating the dynamics of airway recruitment/derecruitment into an anatomically accurate, spatially resolved model of respiratory system mechanics, and the relation of these dynamics to airway dimensions and the biophysical properties of the lining fluid. The importance of our approach is that it potentially allows for more accurate predictions of where mechanical stress foci arise in the lungs, since it is at these locations that injury is thought to arise and propagate from. We match the model to data from a patient with acute respiratory distress syndrome (ARDS) to demonstrate the potential of the model for revealing the underlying derangements in ARDS in a patient-specific manner. To achieve this, the specific geometry of the lung and its heterogeneous pattern of injury are extracted from medical CT images. The mechanical behavior of the model is tailored to the patient's respiratory mechanics using measured ventilation data. In retrospective simulations of various clinically performed, pressure-driven ventilation profiles, the model adequately reproduces clinical quantities measured in the patient such as tidal volume and change in pleural pressure. The model also exhibits physiologically reasonable lung recruitment dynamics and has the spatial resolution to allow the study of local mechanical quantities such as alveolar strains. This modeling approach advances our ability to perform patient-specific studies in silico, opening the way to personalized therapies that will optimize patient outcomes.
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Affiliation(s)
- Carolin M Geitner
- Institute for Computational Mechanics, Department of Engineering Physics & Computation, TUM School of Engineering and Design, Technical University of Munich, Garching b. Muenchen, Germany
| | - Tobias Becher
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Inéz Frerichs
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Norbert Weiler
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Jason H T Bates
- Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont, USA
| | - Wolfgang A Wall
- Institute for Computational Mechanics, Department of Engineering Physics & Computation, TUM School of Engineering and Design, Technical University of Munich, Garching b. Muenchen, Germany
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Pauluhn J. Pathogenetic role of alveolar surfactant depleted by phosgene: Biophysical mechanisms and peak inhalation exposure metrics. Regul Toxicol Pharmacol 2023; 143:105441. [PMID: 37433368 DOI: 10.1016/j.yrtph.2023.105441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/24/2023] [Accepted: 06/29/2023] [Indexed: 07/13/2023]
Abstract
In contrast to water-soluble respiratory tract irritants in their gas phase, the physicochemical properties of 'hydrophilicity' vs. 'lipophilicity' are the preponderant factors that dictate the site of major retention of the gas at the portal of entry. The lipophilic physical properties of phosgene gas facilitate retention in the alveolar region lined with amphipathic pulmonary surfactant (PS). The relationship between exposure and adverse health outcomes is complex, may vary over time, and is dependent on the biokinetics, biophysics, and pool size of PS relative to the inhaled dose of phosgene. Kinetic PS depletion is hypothesized to occur as inhalation followed by inhaled dose-dependent PS depletion. A kinetic model was developed to better understand the variables characterizing the inhaled dose rates of phosgene vs. PS pool size reconstitution. Modeling and empirical data from published evidence revealed that phosgene gas unequivocally follows a concentration x exposure (C × t) metric, independent of the frequency of exposure. The modeled and empirical data support the hypothesis that the exposure standards of phosgene are described best by a C × t time-averaged metric. Modeled data favorably duplicate expert panel-derived standards. Peak exposures within a reasonable range are of no concern.
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Affiliation(s)
- Juergen Pauluhn
- Covestro Deutschland AG, Global Phosgene Steering Group, 51365, Leverkusen, Germany.
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3
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Roles of alpha-7 nicotinic acetylcholine receptors and spleen in the lung injury induced by a repeated saline lavage in rat. BMC Pulm Med 2022; 22:367. [PMID: 36167538 PMCID: PMC9513867 DOI: 10.1186/s12890-022-02151-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 09/12/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The study aimed to determine whether or notα7 nicotinic acetylcholine receptors (α7nAChR) induce anti-inflammatory effects directly in the lung or through the spleen pathway in a sterile model of lung injury by saline lavage. METHODS Male Sprague Dawley rats were divided into seven groups; Sham, splenectomy (SPX), saline lavage (LAV), LAV treated with α7nAChR agonist nicotine (LAV + NIC), and LAV treated with NIC and a selective α7nAChR antagonist MLA (LAV+MLA+NIC), LAV and splenectomy (LAV+SPX), and LAV+SPX treated with nicotine (LAV+SPX+NIC). Tracheostomy and catheterization of the femoral artery were performed under deep anesthesia. Animals were subjected to volume-controlled ventilation and lung injury by 10 repeated saline lavages. Splenectomy was achieved one week before the induction of lung injury. The recovery phase lasted for 3 h, and drugs were injected 1 h after the last lavage. RESULTS Mean arterial blood pressure (MBP), heart rate (HR), PaO2, PaO2/FiO2 ratio, and pH decreased, whereas, maximal inspiratory (MIP) and expiratory (MEP) pressures, and PaCO2 increased 1 h after the saline lavage. Nicotine corrected entirely all the above parameters in the LAV + NIC group. MLA or SPX prevented the effects of nicotine on the above parameters, except that MLA had no extra effect on MIP or MEP. In addition, nicotine improved lung compliance in the LAV + NIC and LAV + SPX + NIC groups, though it was inhibited by MLA in the LAV + MLA + NIC group. The increases of plasma and lung tissue malondialdehyde (MDA) in the LAV group were diminished by nicotine, whereas, MLA and SPX prevented these reductions. Besides, nicotine could reduce plasma MDA in the LAV + SPX + NIC group. Total BAL cell count, protein BAL/protein plasma ratio, and lung histological scores were attenuated by nicotine in the LAV + NIC group, whereas, MLA reversed the mentioned alterations in the LAV + MLA + NIC group. However, splenectomy could not stop the decreasing effect of nicotine on the total BAL cell in the LAV + SPX + NIC group. CONCLUSIONS In this study, we indicated that α7nAChR and spleen play roles in cholinergic anti-inflammatory pathways in saline lavage-induced lung injury. However, our results are in favor of at least some direct effects of α 7nAChR in the lung.
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Agudelo CW, Samaha G, Garcia-Arcos I. Alveolar lipids in pulmonary disease. A review. Lipids Health Dis 2020; 19:122. [PMID: 32493486 PMCID: PMC7268969 DOI: 10.1186/s12944-020-01278-8] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 05/05/2020] [Indexed: 12/15/2022] Open
Abstract
Lung lipid metabolism participates both in infant and adult pulmonary disease. The lung is composed by multiple cell types with specialized functions and coordinately acting to meet specific physiologic requirements. The alveoli are the niche of the most active lipid metabolic cell in the lung, the type 2 cell (T2C). T2C synthesize surfactant lipids that are an absolute requirement for respiration, including dipalmitoylphosphatidylcholine. After its synthesis and secretion into the alveoli, surfactant is recycled by the T2C or degraded by the alveolar macrophages (AM). Surfactant biosynthesis and recycling is tightly regulated, and dysregulation of this pathway occurs in many pulmonary disease processes. Alveolar lipids can participate in the development of pulmonary disease from their extracellular location in the lumen of the alveoli, and from their intracellular location in T2C or AM. External insults like smoke and pollution can disturb surfactant homeostasis and result in either surfactant insufficiency or accumulation. But disruption of surfactant homeostasis is also observed in many chronic adult diseases, including chronic obstructive pulmonary disease (COPD), and others. Sustained damage to the T2C is one of the postulated causes of idiopathic pulmonary fibrosis (IPF), and surfactant homeostasis is disrupted during fibrotic conditions. Similarly, surfactant homeostasis is impacted during acute respiratory distress syndrome (ARDS) and infections. Bioactive lipids like eicosanoids and sphingolipids also participate in chronic lung disease and in respiratory infections. We review the most recent knowledge on alveolar lipids and their essential metabolic and signaling functions during homeostasis and during some of the most commonly observed pulmonary diseases.
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Affiliation(s)
- Christina W Agudelo
- Department of Medicine, SUNY Downstate Health Sciences University, Brooklyn, NY, 11203, USA
| | - Ghassan Samaha
- Department of Medicine, SUNY Downstate Health Sciences University, Brooklyn, NY, 11203, USA
| | - Itsaso Garcia-Arcos
- Department of Medicine, SUNY Downstate Health Sciences University, Brooklyn, NY, 11203, USA.
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Robichaud NAS, Khatami MH, Saika-Voivod I, Booth V. All-Atom Molecular Dynamics Simulations of Dimeric Lung Surfactant Protein B in Lipid Multilayers. Int J Mol Sci 2019; 20:ijms20163863. [PMID: 31398818 PMCID: PMC6719169 DOI: 10.3390/ijms20163863] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/29/2019] [Accepted: 08/06/2019] [Indexed: 02/07/2023] Open
Abstract
Although lung surfactant protein B (SP-B) is an essential protein that plays a crucial role in breathing, the details of its structure and mechanism are not well understood. SP-B forms covalent homodimers, and in this work we use all-atom molecular dynamics simulations to study dimeric SP-B’s structure and its behavior in promoting lipid structural transitions. Four initial system configurations were constructed based on current knowledge of SP-B’s structure and mechanism, and the protein maintained a helicity consistent with experiment in all systems. Several SP-B-induced lipid reorganization behaviors were observed, and regions of the protein particularly important for these activities included SP-B’s “central loop” and “hinge” regions. SP-B dimers with one subunit initially positioned in each of two adjacent bilayers appeared to promote close contact between two bilayers. When both subunits were initially positioned in the same bilayer, SP-B induced the formation of a defect in the bilayer, with water penetrating into the centre of the bilayer. Similarly, dimeric SP-B showed a propensity to interact with preformed interpores in the bilayer. SP-B dimers also promoted bilayer thinning and creasing. This work fleshes out the atomistic details of the dimeric SP-B structures and SP-B/lipid interactions that underlie SP-B’s essential functions.
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Affiliation(s)
- Nicholas A S Robichaud
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, NL A1B 3X7, Canada
| | - Mohammad Hassan Khatami
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, NL A1B 3X7, Canada
| | - Ivan Saika-Voivod
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, NL A1B 3X7, Canada.
| | - Valerie Booth
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, NL A1B 3X7, Canada.
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada.
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Abstract
Activation of TGF-β1 initiates a program of temporary collagen accumulation important to wound repair in many organs. However, the outcome of temporary extracellular matrix strengthening all too frequently morphs into progressive fibrosis, contributing to morbidity and mortality worldwide. To avoid this maladaptive outcome, TGF-β1 signaling is regulated at numerous levels and intimately connected to feedback signals that limit accumulation. Here, we examine the current understanding of the core functions of TGF-β1 in promoting collagen accumulation, parallel pathways that promote physiological repair, and pathological triggers that tip the balance toward progressive fibrosis. Implicit in better understanding of these processes is the identification of therapeutic opportunities that will need to be further advanced to limit or reverse organ fibrosis.
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Affiliation(s)
- Kevin K Kim
- Department of Medicine, University of Michigan School of Medicine, Ann Arbor, Michigan 48109
| | - Dean Sheppard
- Department of Medicine, Cardiovascular Research Institute, and Lung Biology Center, University of California, San Francisco, San Francisco, California 94143
| | - Harold A Chapman
- Department of Medicine, Cardiovascular Research Institute, and Lung Biology Center, University of California, San Francisco, San Francisco, California 94143
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7
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Möller J, Reiss I, Schaible T, Kohl M, Göpel W, Fischer T, Nitsche E, Krüger S. Oxygenation and Lung Morphology in a Rabbit Pediatric ARDS- Model under High Peak Pressure Ventilation plus Nitric Oxide and Surfactant Compared with Veno-venous ECMO. Int J Artif Organs 2018. [DOI: 10.1177/039139889902201108] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The aim of the study is to investigate which of two treatment options of saline lavage induced ARDS in rabbits is better in terms of oxygenation and prevention of barotrauma: combined high peak pressure ventilation with surfactant administration and inhaled nitric oxide or veno-venous ECMO combined with low peak inspiratory pressure ventilation. Materials and Methods After saline lavage (10 cc/kg repeated as long as foamy retrieval was observed) two combined therapeutic strategies were examined: ventilation with high inspiratory pressures (35 cm H2O) with additional exogenous surfactant administration (100 mg/kg) and inhaled nitric oxide (10 PPM) (n=5, group 1) and low inspiratory pressure (20 cm H2O) ventilation under veno-venous ECMO support (n=5, group 2). The FiO2 was maintained at 1.0 in both groups. The paO2/FiO2 ratio was calculated in 30 minute intervals for 4 hours. After that the animals were sacrificed and the lungs examined macro- and microscopically. Aeration was described in a semiquantitative method using the alveolar expansion index. Oxygenation in group 1 was significantly better than in group 2, it increased significantly after surfactant but not after additional nitric oxide administration. However, the lungs in group 1 showed severe signs of baro/ergotrauma (Hyaline membranes, air leaks, infiltration of polymorphonuclear (PMN) granulocytes and macrophages, break down of alveolar capillary membranes) after 4 hrs of combined therapy, whereas the lungs in group 2 appeared normal. Adding surfactant and NO to a high tidal volume ventilation improved oxygenation, but did not prevent baro/ergotrauma. Ventilation with low inspiratory pressures combined with ECMO caused little baro/ergotrauma but adequate oxygenation could not be achieved, probably due to anatomical features of the rabbit which do not allow appropriate blood flow within the ECMO-circuit.
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Affiliation(s)
- J.C. Möller
- Departments of Pediatrics and Anaesthesiology, Medical University of Lübeck, Lübeck - Germany
| | - I. Reiss
- Departments of Pediatrics and Anaesthesiology, Medical University of Lübeck, Lübeck - Germany
| | - T.F. Schaible
- Departments of Pediatrics and Anaesthesiology, Medical University of Lübeck, Lübeck - Germany
| | - M. Kohl
- Departments of Pediatrics and Anaesthesiology, Medical University of Lübeck, Lübeck - Germany
| | - W. Göpel
- Departments of Pediatrics and Anaesthesiology, Medical University of Lübeck, Lübeck - Germany
| | - T. Fischer
- Departments of Pediatrics and Anaesthesiology, Medical University of Lübeck, Lübeck - Germany
| | - E.M. Nitsche
- Departments of Pediatrics and Anaesthesiology, Medical University of Lübeck, Lübeck - Germany
| | - S. Krüger
- Institute of Pathology, Medical University of Lübeck, Lübeck - Germany
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8
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Möller J, Schaible T, Reiss I, Artlich A, Gortner L. Treatment of Severe Non-Neonatal ARDS in Children with Surfactant and Nitric Oxide in a “PRE-ECMO”-Situation. Int J Artif Organs 2018. [DOI: 10.1177/039139889501801009] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The use of exogenous surfactant and nitric oxide in neonates has reduced the number of infants requiring ECMO. The purpose of this study was to demonstrate whether these two therapeutic options might reduce the number of over 28 days old children with severe ARDS requiring ECMO, without reducing changes of survival and morbidity. Over a 30 month period all non-neonatal ARDS patients transferred to our institution for ECMO evaluation were treated based on a study-algorithm. If they did not fulfill “fast entry criteria” (paO2< 40 for more than 3 hrs.) we first tried different ventilation, vasodilatation, and hemodynamic strategies for max. 4 hrs. (inv. I/E ratio, HFOV, epoprostenol, high doses norepinephrine. If the 01 did not decrease by< 10, 30-280 mg natural surfactant or 1-20 ppm nitric oxide were treatment options depending on the degree of pulmonary hypertension measured by echocardiography and by mixed venous saturation measurements. It was possible to use NO and surfactant sequentially. The patients had different etiologies of ARDS as near drowning, pneumonia, immunosuppression, and sepsis. If their 01 did not decrease by 10 in 8 hrs. ECMO was installed. Nineteen patients were evaluated, 6 improved with conventional therapy, their 01 decreased without a relapse (mean 01 at begin of the study: 38). Six patients improved with surfactant therapy alone (mean 01: 54), 4 patients improved after surfactant and sequential NO-treatment, 3 patients were initially treated with NO, 1 sequentially with surfactant. One patient did not show any benefit from NO or surfactant and was put on ECMO. Three patients died (withdrawal of life support because of severe brain damage caused by the underlying disease). We could not observe any respiratory related failure. No patient had to be discharged on oxygen. A sophisticated treatment algorithm integrating different modern ARDS treatment options can reduce the number of patients requiring ECMO. We speculate however that these options can only be used effectively in centers involved in ARDS treatment quite frequently and that these centers have to provide ECMO as one of their therapeutic tools.
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Affiliation(s)
- J.C. Möller
- ICU, Department of Pediatrics, Medical University of Lübeck - Germany
| | - T.F. Schaible
- ICU, Department of Pediatrics, Medical University of Lübeck - Germany
| | - I. Reiss
- ICU, Department of Pediatrics, Medical University of Lübeck - Germany
| | - A. Artlich
- ICU, Department of Pediatrics, Medical University of Lübeck - Germany
| | - L Gortner
- ICU, Department of Pediatrics, Medical University of Lübeck - Germany
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Romaní-Pérez M, Outeiriño-Iglesias V, Moya CM, Santisteban P, González-Matías LC, Vigo E, Mallo F. Activation of the GLP-1 Receptor by Liraglutide Increases ACE2 Expression, Reversing Right Ventricle Hypertrophy, and Improving the Production of SP-A and SP-B in the Lungs of Type 1 Diabetes Rats. Endocrinology 2015. [PMID: 26196539 DOI: 10.1210/en.2014-1685] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Diabetes alters microvascular function in the vascular beds of organs, including the lungs. Cardiovascular complications of pulmonary vascular affectation may be a consequence of the overactivation of the vasoconstrictive and proliferative components of the renin-angiotensin system. We previously reported that pulmonary physiology and surfactant production is improved by the glucagon-like peptide 1 receptor (GLP-1R) agonist liraglutide (LIR) in a rat model of lung hypoplasia. Because we hypothesized that streptozotocin-induced diabetes rats would show deficiencies in lung function, including surfactant proteins, and develop an imbalance of the renin-angiotensin system in the lungs. This effect would in turn be prevented by long-acting agonists of the GLP-1R, such as LIR. The induction of diabetes reduced the surfactant protein A and B in the lungs and caused the vasoconstrictor component of the renin-angiotensin system to predominate, which in turn increased angiotensin II levels, and ultimately being associated with right ventricle hypertrophy. LIR restored surfactant protein levels and reversed the imbalance in the renin-angiotensin system in this type 1 diabetes mellitus rat model. Moreover, LIR provoked a strong increase in angiotensin-converting enzyme 2 expression in the lungs of both diabetic and control rats, and in the circulating angiotensin(1-7) in diabetic animals. These effects prompted complete reversion of right ventricle hypertrophy. The consequences of LIR administration were independent of glycemic control and of glucocorticoids, and they involved NK2 homeobox 1 signaling. This study demonstrates by first time that GLP-1R agonists, such as LIR, might improve the cardiopulmonary complications associated with diabetes.
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Affiliation(s)
- Marina Romaní-Pérez
- Laboratory of Endocrinology (M.R.-P., V.O.-I., L.C.G.-M., E.V., F.M.), Centre for Biomedical Research (CINBIO), University of Vigo, Faculty of Biology, E-36310 Vigo, Spain; Institute for Biomedical Research of Vigo (IBIV) (M.R.-P., V.O.-I., L.C.G.-M., E.V., F.M.), University of Vigo/Sergas, E36310, Vigo, Spain; and Institute Biomedical Research Alberto Sols (C.M.M., P.S.), Spanish Council of Research, Universidad Autónoma de Madrid, Madrid E28029, Spain
| | - Verónica Outeiriño-Iglesias
- Laboratory of Endocrinology (M.R.-P., V.O.-I., L.C.G.-M., E.V., F.M.), Centre for Biomedical Research (CINBIO), University of Vigo, Faculty of Biology, E-36310 Vigo, Spain; Institute for Biomedical Research of Vigo (IBIV) (M.R.-P., V.O.-I., L.C.G.-M., E.V., F.M.), University of Vigo/Sergas, E36310, Vigo, Spain; and Institute Biomedical Research Alberto Sols (C.M.M., P.S.), Spanish Council of Research, Universidad Autónoma de Madrid, Madrid E28029, Spain
| | - Christian M Moya
- Laboratory of Endocrinology (M.R.-P., V.O.-I., L.C.G.-M., E.V., F.M.), Centre for Biomedical Research (CINBIO), University of Vigo, Faculty of Biology, E-36310 Vigo, Spain; Institute for Biomedical Research of Vigo (IBIV) (M.R.-P., V.O.-I., L.C.G.-M., E.V., F.M.), University of Vigo/Sergas, E36310, Vigo, Spain; and Institute Biomedical Research Alberto Sols (C.M.M., P.S.), Spanish Council of Research, Universidad Autónoma de Madrid, Madrid E28029, Spain
| | - Pilar Santisteban
- Laboratory of Endocrinology (M.R.-P., V.O.-I., L.C.G.-M., E.V., F.M.), Centre for Biomedical Research (CINBIO), University of Vigo, Faculty of Biology, E-36310 Vigo, Spain; Institute for Biomedical Research of Vigo (IBIV) (M.R.-P., V.O.-I., L.C.G.-M., E.V., F.M.), University of Vigo/Sergas, E36310, Vigo, Spain; and Institute Biomedical Research Alberto Sols (C.M.M., P.S.), Spanish Council of Research, Universidad Autónoma de Madrid, Madrid E28029, Spain
| | - Lucas C González-Matías
- Laboratory of Endocrinology (M.R.-P., V.O.-I., L.C.G.-M., E.V., F.M.), Centre for Biomedical Research (CINBIO), University of Vigo, Faculty of Biology, E-36310 Vigo, Spain; Institute for Biomedical Research of Vigo (IBIV) (M.R.-P., V.O.-I., L.C.G.-M., E.V., F.M.), University of Vigo/Sergas, E36310, Vigo, Spain; and Institute Biomedical Research Alberto Sols (C.M.M., P.S.), Spanish Council of Research, Universidad Autónoma de Madrid, Madrid E28029, Spain
| | - Eva Vigo
- Laboratory of Endocrinology (M.R.-P., V.O.-I., L.C.G.-M., E.V., F.M.), Centre for Biomedical Research (CINBIO), University of Vigo, Faculty of Biology, E-36310 Vigo, Spain; Institute for Biomedical Research of Vigo (IBIV) (M.R.-P., V.O.-I., L.C.G.-M., E.V., F.M.), University of Vigo/Sergas, E36310, Vigo, Spain; and Institute Biomedical Research Alberto Sols (C.M.M., P.S.), Spanish Council of Research, Universidad Autónoma de Madrid, Madrid E28029, Spain
| | - Federico Mallo
- Laboratory of Endocrinology (M.R.-P., V.O.-I., L.C.G.-M., E.V., F.M.), Centre for Biomedical Research (CINBIO), University of Vigo, Faculty of Biology, E-36310 Vigo, Spain; Institute for Biomedical Research of Vigo (IBIV) (M.R.-P., V.O.-I., L.C.G.-M., E.V., F.M.), University of Vigo/Sergas, E36310, Vigo, Spain; and Institute Biomedical Research Alberto Sols (C.M.M., P.S.), Spanish Council of Research, Universidad Autónoma de Madrid, Madrid E28029, Spain
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Ochiai R. Mechanical ventilation of acute respiratory distress syndrome. J Intensive Care 2015; 3:25. [PMID: 26045965 PMCID: PMC4456061 DOI: 10.1186/s40560-015-0091-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 05/13/2015] [Indexed: 02/06/2023] Open
Abstract
Acute respiratory distress syndrome (ARDS) has been intensively and continuously studied in various settings, but its mortality is still as high as 30-40 %. For the last 20 years, lung protective strategy has become a standard care for ARDS, but we still do not know the best way to ventilate patients with ARDS. Tidal volume itself does not seem to have an important role to develop ventilator-induced lung injury (VILI), but the driving pressure, which is inspiratory plateau pressure-PEEP, is the most important to predict and affect the outcome of ARDS, though there is no safe limit for the driving pressure. There is so much controversy regarding what the best PEEP is, whether collapsed lung should be recruited, and what parameters should be measured and evaluated to improve the outcome of ARDS. Since the mechanical ventilation for patients with respiratory failure, including ARDS, is a standard care, we need more dynamic and regional information of ventilation and pulmonary circulation in the injured lungs to evaluate the efficacy of new type of treatment strategy. In addition to the CT scanning of the lung as the gold standard of evaluation, the electrical impedance tomography (EIT) of the lung has been clinically available to provide such information non-invasively and at the bedside. Various parameters have been tested to evaluate the homogeneity of regional ventilation, and EIT could provide us with the information of ventilator settings to minimize VILI.
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Affiliation(s)
- Ryoichi Ochiai
- Department of Anesthesiology, School of Medicine, Toho University, 6-11-1, Oomori-nishi, Oota-city, Tokyo 143-8541 Japan
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11
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Abstract
Mechanical ventilation (MV) is, by definition, the application of external forces to the lungs. Depending on their magnitude, these forces can cause a continuum of pathophysiological alterations ranging from the stimulation of inflammation to the disruption of cell-cell contacts and cell membranes. These side effects of MV are particularly relevant for patients with inhomogeneously injured lungs such as in acute lung injury (ALI). These patients require supraphysiological ventilation pressures to guarantee even the most modest gas exchange. In this situation, ventilation causes additional strain by overdistension of the yet non-injured region, and additional stress that forms because of the interdependence between intact and atelectatic areas. Cells are equipped with elaborate mechanotransduction machineries that respond to strain and stress by the activation of inflammation and repair mechanisms. Inflammation is the fundamental response of the host to external assaults, be they of mechanical or of microbial origin and can, if excessive, injure the parenchymal tissue leading to ALI. Here, we will discuss the forces generated by MV and how they may injure the lungs mechanically and through inflammation. We will give an overview of the mechanotransduction and how it leads to inflammation and review studies demonstrating that ventilator-induced lung injury can be prevented by blocking pathways of mechanotransduction or inflammation.
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Affiliation(s)
- Ulrike Uhlig
- Department of Pharmacology & Toxicology, Medical Faculty, RWTH Aachen University, Aachen, Germany
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12
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Sharifahmadian M, Sarker M, Palleboina D, Waring AJ, Walther FJ, Morrow MR, Booth V. Role of the N-terminal seven residues of surfactant protein B (SP-B). PLoS One 2013; 8:e72821. [PMID: 24023779 PMCID: PMC3759391 DOI: 10.1371/journal.pone.0072821] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 07/19/2013] [Indexed: 12/21/2022] Open
Abstract
Breathing is enabled by lung surfactant, a mixture of proteins and lipids that forms a surface-active layer and reduces surface tension at the air-water interface in lungs. Surfactant protein B (SP-B) is an essential component of lung surfactant. In this study we probe the mechanism underlying the important functional contributions made by the N-terminal 7 residues of SP-B, a region sometimes called the “insertion sequence”. These studies employed a construct of SP-B, SP-B (1–25,63–78), also called Super Mini-B, which is a 41-residue peptide with internal disulfide bonds comprising the N-terminal 7-residue insertion sequence and the N- and C-terminal helices of SP-B. Circular dichroism, solution NMR, and solid state 2H NMR were used to study the structure of SP-B (1–25,63–78) and its interactions with phospholipid bilayers. Comparison of results for SP-B (8–25,63–78) and SP-B (1–25,63–78) demonstrates that the presence of the 7-residue insertion sequence induces substantial disorder near the centre of the lipid bilayer, but without a major disruption of the overall mechanical orientation of the bilayers. This observation suggests the insertion sequence is unlikely to penetrate deeply into the bilayer. The 7-residue insertion sequence substantially increases the solution NMR linewidths, most likely due to an increase in global dynamics.
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Affiliation(s)
- Mahzad Sharifahmadian
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Muzaddid Sarker
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Dharamaraju Palleboina
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Alan J. Waring
- Department of Medicine at Harbor UCLA, Division of Molecular Medicine, Torrance, California, United States of America
| | - Frans J. Walther
- Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Centre, Torrance, California, United States of America
- Department of Pediatrics, Leiden University Medical Centre, Leiden, The Netherlands
| | - Michael R. Morrow
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Valerie Booth
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
- * E-mail:
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13
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Abstract
Multiorgan failure (MOF) represents the leading cause of death in patients with sepsis and systemic inflammatory response syndrome (SIRS) following severe trauma. The underlying immune response is highly complex and involves activation of the complement system as a crucial entity of innate immunity. Uncontrolled activation of the complement system during sepsis and SIRS with in excessive generation of complement activation products contributes to an ensuing dysfunction of various organ systems. In the present review, mechanisms of the inflammatory response in the development of MOF in sepsis and SIRS with particular focus on the complement system are discussed.
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14
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Fang X, Bai C, Wang X. Potential clinical application of KGF-2 (FGF-10) for acute lung injury/acute respiratory distress syndrome. Expert Rev Clin Pharmacol 2012; 3:797-805. [PMID: 22111782 DOI: 10.1586/ecp.10.59] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is an acute life-threatening form of hypoxemic respiratory failure with a high mortality rate, and there is still a great need for more effective therapies for such a severe and lethal disease. Dysfunction of endothelial and epithelial barriers is one of the most important mechanisms in hypoxia-associated ALI/ARDS. The acceleration of the epithelial repair process in the injured lung may provide an effective therapeutic target. KGF-2, a potent alveolar epithelial cell mitogen, plays an important role in organ morphogenesis and epithelial differentiation, and modulates a variety of mechanisms recognized to be important in alveolar repair and resolution in ALI/ARDS. Preclinical and clinical studies have suggested that KGF-2 may be the candidate of novel therapies for alveolar epithelial damage during ALI/ARDS.
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Affiliation(s)
- Xiaocong Fang
- Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.
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15
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A combined action of pulmonary surfactant proteins SP-B and SP-C modulates permeability and dynamics of phospholipid membranes. Biochem J 2011; 438:555-64. [DOI: 10.1042/bj20110681] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Proteins SP-B and SP-C are essential to promote formation of surface-active films at the respiratory interface, but their mechanism of action is still under investigation. In the present study we have analysed the effect of the proteins on the accessibility of native, quasi-native and model surfactant membranes to incorporation of the fluorescent probes Nile Red (permeable) and FM 1-43 (impermeable) into membranes. We have also analysed the effect of single or combined proteins on membrane permeation using the soluble fluorescent dye calcein. The fluorescence of FM 1-43 was always higher in membranes containing SP-B and/or SP-C than in protein-depleted membranes, in contrast with Nile Red which was very similar in all of the materials tested. SP-B and SP-C promoted probe partition with markedly different kinetics. On the other hand, physiological proportions of SP-B and SP-C caused giant oligolamellar vesicles to incorporate FM 1-43 from the external medium into apparently most of the membranes instantaneously. In contrast, oligolamellar pure lipid vesicles appeared to be mainly labelled in the outermost membrane layer. Pure lipidic vesicles were impermeable to calcein, whereas it permeated through membranes containing SP-B and/or SP-C. Vesicles containing only SP-B were stable, but prone to vesicle–vesicle interactions, whereas those containing only SP-C were extremely dynamic, undergoing frequent fluctuations and ruptures. Differential structural effects of proteins on vesicles were confirmed by electron microscopy. These results suggest that SP-B and SP-C have different contributions to inter- and intra-membrane lipid dynamics, and that their combined action could provide unique effects to modulate structure and dynamics of pulmonary surfactant membranes and films.
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16
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Raghavendran K, Willson D, Notter RH. Surfactant therapy for acute lung injury and acute respiratory distress syndrome. Crit Care Clin 2011; 27:525-59. [PMID: 21742216 PMCID: PMC3153076 DOI: 10.1016/j.ccc.2011.04.005] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
This article examines exogenous lung surfactant replacement therapy and its usefulness in mitigating clinical acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS). Surfactant therapy is beneficial in term infants with pneumonia and meconium aspiration lung injury, and in children up to age 21 years with direct pulmonary forms of ALI/ARDS. However, extension of exogenous surfactant therapy to adults with respiratory failure and clinical ALI/ARDS remains a challenge. This article reviews clinical studies of surfactant therapy in pediatric and adult patients with ALI/ARDS, focusing on its potential advantages in patients with direct pulmonary forms of these syndromes.
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Affiliation(s)
- Krishnan Raghavendran
- Division of Acute Care Surgery, Department of Surgery, University of Michigan Health System, 1500 East Medical Center Drive, 1C340A-UH, SPC 5033, Ann Arbor, MI 48109-5033, USA.
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17
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Beck-Broichsitter M, Ruppert C, Schmehl T, Guenther A, Betz T, Bakowsky U, Seeger W, Kissel T, Gessler T. Biophysical investigation of pulmonary surfactant surface properties upon contact with polymeric nanoparticles in vitro. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2011; 7:341-50. [DOI: 10.1016/j.nano.2010.10.007] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 10/12/2010] [Accepted: 10/17/2010] [Indexed: 02/05/2023]
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18
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Sarker M, Rose J, McDonald M, Morrow MR, Booth V. Modifications to surfactant protein B structure and lipid interactions under respiratory distress conditions: consequences of tryptophan oxidation. Biochemistry 2010; 50:25-36. [PMID: 21128671 DOI: 10.1021/bi101426s] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
These studies detail the altered structure-function relationships caused by oxidation of surfactant protein B (SP-B), a mode of damage thought to be important in acute respiratory distress syndrome (ARDS), a common and frequently fatal condition. An 18-residue fragment comprising the N-terminal helix of SP-B was investigated in oxidized and unmodified forms by solution and solid-state nuclear magnetic resonance (NMR), circular dichroism (CD), and molecular dynamics (MD) simulation. Taken together, the results indicate that tryptophan oxidation causes substantial disruptions in helical structure and lipid interactions. The structural modifications induced by tryptophan oxidation were severe, with a reduction in helical extent from approximately three helical turns to, at most, one turn, and were observed in a variety of solvent environments, including sodium dodecyl sulfate (SDS) micelles, dodecyl phosphocholine (DPC) micelles, and a 40% hexafluoro-2-propanol (HFIP) aqueous solution. The unmodified peptide takes on an orientation within lipid bilayers that is tilted approximately 30° away from an in-plane position. Tryptophan oxidation causes significant modifications to the peptide-lipid interactions, and the peptide likely shifts to a more in-plane orientation within the lipids. Interestingly, the character of the disruptions to peptide-lipid interactions caused by tryptophan oxidation was highly dependent on the charge of the lipid headgroup.
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Affiliation(s)
- Muzaddid Sarker
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, NL, Canada
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19
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Beck-Schimmer B, Schimmer RC. Perioperative tidal volume and intra-operative open lung strategy in healthy lungs: where are we going? Best Pract Res Clin Anaesthesiol 2010; 24:199-210. [PMID: 20608557 PMCID: PMC10068647 DOI: 10.1016/j.bpa.2010.02.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Tidal volumes have tremendously decreased over the last decades from <15 ml kg(-1) to approximately 6 ml kg(-1) actual body weight. Guidelines, widely agreed and used, exist for patients with acute lung injury or acute respiratory distress syndrome (ARDS). However, it is questionable if data created in patients with acute lung injury or ARDS from ventilation on intensive care units can be transferred to healthy patients undergoing surgery. Consensus criteria regarding this topic are still missing because only a few randomised controlled trials have been performed to date, focussing on the use of the best intra-operative tidal volume. The same problem has been observed regarding the application of positive end-expiratory pressure (PEEP) and intra-operative lung recruitment. This article provides an overview of the current literature addressing the size of tidal volume, the use of PEEP and the application of the open-lung concept in patients without acute lung injury or ARDS. Pathophysiological aspects of mechanical ventilation are elucidated.
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20
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Frey SL, Pocivavsek L, Waring AJ, Walther FJ, Hernandez-Juviel JM, Ruchala P, Lee KYC. Functional importance of the NH2-terminal insertion sequence of lung surfactant protein B. Am J Physiol Lung Cell Mol Physiol 2009; 298:L335-47. [PMID: 20023175 DOI: 10.1152/ajplung.00190.2009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Lung surfactant protein B (SP-B) is required for proper surface activity of pulmonary surfactant. In model lung surfactant lipid systems composed of saturated and unsaturated lipids, the unsaturated lipids are removed from the film at high compression. It is thought that SP-B helps anchor these lipids closely to the monolayer in three-dimensional cylindrical structures termed "nanosilos" seen by atomic force microscopy imaging of deposited monolayers at high surface pressures. Here we explore the role of the SP-B NH(2) terminus in the formation and stability of these cylindrical structures, specifically the distribution of lipid stack height, width, and density with four SP-B truncation peptides: SP-B 1-25, SP-B 9-25, SP-B 11-25, and SP-B 1-25Nflex (prolines 2 and 4 substituted with alanine). The first nine amino acids, termed the insertion sequence and the interface seeking tryptophan residue 9, are shown to stabilize the formation of nanosilos while an increase in the insertion sequence flexibility (SP-B 1-25Nflex) may improve peptide functionality. This provides a functional understanding of the insertion sequence beyond anchoring the protein to the two-dimensional membrane lining the lung, as it also stabilizes formation of nanosilos, creating reversible repositories for fluid lipids at high compression. In lavaged, surfactant-deficient rats, instillation of a mixture of SP-B 1-25 (as a monomer or dimer) and synthetic lung lavage lipids quickly improved oxygenation and dynamic compliance, whereas SP-B 11-25 surfactants showed oxygenation and dynamic compliance values similar to that of lipids alone, demonstrating a positive correlation between formation of stable, but reversible, nanosilos and in vivo efficacy.
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Affiliation(s)
- Shelli L Frey
- Department of Chemistry, Institute for Biophysical Dynamics and James Franck Institute, The University of Chicago,929 E. 57 St., Chicago, IL 60637, USA
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21
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Kesecioglu J, Beale R, Stewart TE, Findlay GP, Rouby JJ, Holzapfel L, Bruins P, Steenken EJ, Jeppesen OK, Lachmann B. Exogenous Natural Surfactant for Treatment of Acute Lung Injury and the Acute Respiratory Distress Syndrome. Am J Respir Crit Care Med 2009; 180:989-94. [DOI: 10.1164/rccm.200812-1955oc] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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22
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Cholesterol modulates the exposure and orientation of pulmonary surfactant protein SP-C in model surfactant membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:1907-15. [DOI: 10.1016/j.bbamem.2009.05.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Revised: 04/24/2009] [Accepted: 05/07/2009] [Indexed: 01/08/2023]
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23
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Zhang Y, Zhu J, Tang Y, Chen X, Yang Y. The preparation and application of pulmonary surfactant nanoparticles as absorption enhancers in insulin dry powder delivery. Drug Dev Ind Pharm 2009; 35:1059-65. [DOI: 10.1080/03639040902769628] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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24
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Han JJ, Yim HE, Lee JH, Kim YK, Jang GY, Choi BM, Yoo KH, Hong YS. Albumin versus normal saline for dehydrated term infants with metabolic acidosis due to acute diarrhea. J Perinatol 2009; 29:444-7. [PMID: 19158801 DOI: 10.1038/jp.2008.244] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
UNLABELLED To compare the efficacy of albumin to normal saline (NS) for initial hydration therapy for dehydrated term infants with severe metabolic acidosis due to acute diarrhea. STUDY DESIGN We randomized 33 infants presenting with moderate-to-severe dehydration and metabolic acidosis (pH <7.25 or base excess (BE) <-15) into two groups, an albumin group (n=15) and a NS group (n=18). For initial hydration treatment, the albumin group received 5% albumin (10 ml kg(-1)), whereas the NS group received NS (10 ml kg(-1)). RESULT After 3 h of treatment, both groups improved. However, the magnitude of improvement in the pH, BE and HCO(3)(-) levels were not different in comparisons between these two groups. In addition, there were no differences either in the body weight and weight gain 4 days after treatment or in the length of hospital stay. CONCLUSION Albumin was not more effective than NS for initial hydration treatment of dehydrated term infants with metabolic acidosis due to acute diarrhea.
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Affiliation(s)
- J J Han
- Department of Pediatrics, College of Medicine, Korea University, Seoul, Republic of Korea
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25
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Salvesen B, Mollnes TE, Saugstad OD. Albumin lavage does not improve the outcome of meconium aspiration syndrome. J Matern Fetal Neonatal Med 2009; 21:719-25. [PMID: 19012188 DOI: 10.1080/14767050802255561] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
OBJECTIVE Meconium aspiration syndrome is still a serious condition with high mortality and morbidity. No specific treatment is yet available, although surfactant is known to reduce the need for extracorporeal membrane oxygenation and surfactant lavage has shown promising results in animal studies. Our group has previously shown reduced oxygenation index in an experimental model of meconium aspiration syndrome in newborn pigs when mixing albumin with meconium before endotracheal instillation. Lung compliance increased when albumin was instilled after meconium as a rescue. The aim of this study was to combine the effect of albumin and lavage. METHODS Sixteen newborn pigs (six in the meconium-albumin group, six in the meconium group, and four control animals) were anesthetized and tracheotomized. Meconium 4 mL/kg was instilled endotracheally. After five minutes, albumin 15 mL/kg was instilled in the meconium-albumin group followed by endotracheal suctioning. The observation time was six hours. Respiratory and hemodynamic parameters were measured. The terminal complement complex and proinflammatory cytokines were analyzed in plasma. RESULTS Oxygenation index, ventilatory index, and the terminal complement complex (sC5b-9) increased significantly in both groups, but significantly more in the meconium-albumin group. Compliance decreased, but significantly more in the meconium-albumin group. The terminal sC5b-9 complex increased in both groups, but significantly more in the meconium-albumin group. Tumor necrosis factor-alpha, interleukin (IL)- 1beta, and IL-6 increased significantly in both groups. CONCLUSION Albumin-lavage did not improve the outcome of experimental meconium aspiration syndrome.
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Affiliation(s)
- Bodil Salvesen
- Department of Pediatric Research, Medical Faculty, University of Oslo and Rikshospitalet University Hospital, Oslo, Norway.
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26
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Soni N, Williams P. Positive pressure ventilation: what is the real cost? Br J Anaesth 2008; 101:446-57. [PMID: 18782885 DOI: 10.1093/bja/aen240] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Positive pressure ventilation is a radical departure from the physiology of breathing spontaneously. The immediate physiological consequences of positive pressure ventilation such as haemodynamic changes are recognized, studied, and understood. There are other significant physiological interactions which are less obvious, more insidious, and may only produce complications if ventilation is prolonged. The interaction of positive pressure with airway resistance and alveolar compliance affects distribution of gas flow within the lung. The result is a wide range of ventilation efficacy throughout different areas of the lung, but the pressure differentials between alveolus and interstitium also influence capillary perfusion. The hydrostatic forces across the capillaries associated with the effects of raised venous pressures compound these changes resulting in interstitial fluid sequestration. This is increased by impaired lymphatic drainage which is secondary to raised intrathoracic pressure but also influenced by raised central venous pressure. Ventilation and PEEP promulgate further physiological derangement. In theory, avoiding these physiological disturbances in a rested lung may be better for the lung and other organs. An alternative to positive pressure ventilation might be to investigate oxygen supplementation of a physiologically neutral and rested lung. Abandoning heroic ventilation would be a massive departure from current practice but might be a more rationale approach to future practice.
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Affiliation(s)
- N Soni
- Imperial College Medical School, Chelsea and Westminster Hospital, 369 Fulham Road, London SW10 9NH, UK.
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27
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van Helden HPM, van de Meent D, Oostdijk JP, Joosen MJA, van Esch JHM, Hammer AH, Diemel RV. Protection of Rats Against Perfluoroisobutene (PFIB)-Induced Pulmonary Edema by Curosurf andN-Acetylcysteine. Inhal Toxicol 2008; 16:549-64. [PMID: 15204746 DOI: 10.1080/08958370490442575] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Airborne exposure to lung-toxic agents may damage the lung surfactant system and epithelial and endothelial cells, resulting in a life-threatening pulmonary edema that is known to be refractory to treatment. The aim of this study was to investigate in rats (1) the respiratory injury caused by nose-only exposure to perfluoroisobutene (PFIB), and (2) the therapeutic efficacy of a treatment at 4 and/or 8 h after exposure consisting of the natural surfactant Curosurf and/or the anti-inflammatory drug N-acetylcysteine (NAC). For that purpose, the following parameters were examined: respiratory frequency (RF), lung compliance (Cdyn), airway resistance (Raw), lung wet weight (LWW), airway histopathology; and in brochoalveolar lavage (BAL) fluid, total protein, total phospholipid, cell count and differentiation, and changes in the surface tension of the BAL fluid. The mean (+/- SEM) surface tension of BAL fluid derived from PFIB-exposed (C . t = 1100-1200 mg min(-1) m(-3), approximately 1LCt50; t = 20 min) animals at 24 h following exposure (11 +/- 3 mN/m) was higher than that of unexposed rats (0.8 +/- 0.4 mN/m), reflecting damage to the surfactant system and justifying treatment with exogenous surfactant. Curosurf treatment (62.5 mg/kg i.t.) decreased pulmonary edema caused by PFIB, reflected by a decreased LWW, and decreased the amount of protein in BAL fluid. NAC treatment (1000 mmol/kg ip) inhibited the interstitial pneumonia reflected by a decreased percentage of neutrophils in the alveolar space. It was concluded that a combined treatment of Curosurf + NAC improved respiration, that is, RF and Cdyn, whereby Curosurf predominantly decreased pulmonary edema and NAC predominantly reduced the inflammatory process. A combined treatment may therefore be considered a promising therapeutic approach in early-stage acute respiratory distress caused by PFIB, although the treatment regimes need further investigation.
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Affiliation(s)
- Herman P M van Helden
- Department of Medical Countermeasures TNO Prins Maurits Laboratory, Rijswijk, the Netherlands.
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28
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Rittirsch D, Flierl MA, Day DE, Nadeau BA, McGuire SR, Hoesel LM, Ipaktchi K, Zetoune FS, Sarma JV, Leng L, Huber-Lang MS, Neff TA, Bucala R, Ward PA. Acute lung injury induced by lipopolysaccharide is independent of complement activation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 180:7664-72. [PMID: 18490769 PMCID: PMC2753408 DOI: 10.4049/jimmunol.180.11.7664] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although acute lung injury (ALI) is an important problem in humans, its pathogenesis is poorly understood. Airway instillation of bacterial LPS, a known complement activator, represents a frequently used model of ALI. In the present study, pathways in the immunopathogenesis of ALI were evaluated. ALI was induced in wild-type, C3(-/-), and C5(-/-) mice by airway deposition of LPS. To assess the relevant inflammatory mediators, bronchoalveolar lavage fluids were evaluated by ELISA analyses and various neutralizing Abs and receptor antagonists were administered in vivo. LPS-induced ALI was neutrophil-dependent, but it was not associated with generation of C5a in the lung and was independent of C3, C5, or C5a. Instead, LPS injury was associated with robust generation of macrophage migration inhibitory factor (MIF), leukotriene B(4) (LTB4), and high mobility group box 1 protein (HMGB1) and required engagement of receptors for both MIF and LTB4. Neutralization of MIF or blockade of the MIF receptor and/or LTB4 receptor resulted in protection from LPS-induced ALI. These findings indicate that the MIF and LTB4 mediator pathways are involved in the immunopathogenesis of LPS-induced experimental ALI. Most strikingly, complement activation does not contribute to the development of ALI in the LPS model.
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Affiliation(s)
- Daniel Rittirsch
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Michael A. Flierl
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Danielle E. Day
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Brian A. Nadeau
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Stephanie R. McGuire
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Laszlo M. Hoesel
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109
- Department of Traumatology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Kyros Ipaktchi
- Department of Traumatology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Firas S. Zetoune
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - J. Vidya Sarma
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Lin Leng
- Department of Medicine and Pathology, Yale University School of Medicine, The Anlyan Center, New Haven, CT 06520
| | - Markus S. Huber-Lang
- Department of Traumatology, Hand, Plastic, and Reconstructive Surgery, University Hospital Ulm, Ulm, Germany
| | - Thomas A. Neff
- Department of Anesthesiology, University Hospital Zurich, Zurich, Switzerland
| | - Richard Bucala
- Department of Medicine and Pathology, Yale University School of Medicine, The Anlyan Center, New Haven, CT 06520
| | - Peter A. Ward
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109
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29
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Abstract
This article reviews exogenous surfactant therapy and its use in mitigating acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS) in infants, children, and adults. Biophysical and animal research documenting surfactant dysfunction in ALI/ARDS is described, and the scientific rationale for treatment with exogenous surfactant is discussed. Major emphasis is placed on reviewing clinical studies of surfactant therapy in pediatric and adult patients who have ALI/ARDS. Particular advantages from surfactant therapy in direct pulmonary forms of these syndromes are described. Also discussed are additional factors affecting the efficacy of exogenous surfactants in ALI/ARDS.
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Affiliation(s)
- Douglas F Willson
- Pediatric ICU and Division of Pediatric Critical Care, University of Virginia Children's Medical Center, UVA Health Sciences System, Box 800386, Charlottesville, VA 22908-0386, USA.
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30
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Raghavendran K, Pryhuber GS, Chess PR, Davidson BA, Knight PR, Notter RH. Pharmacotherapy of acute lung injury and acute respiratory distress syndrome. Curr Med Chem 2008; 15:1911-24. [PMID: 18691048 PMCID: PMC2636692 DOI: 10.2174/092986708785132942] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS) are characterized by rapid-onset respiratory failure following a variety of direct and indirect insults to the parenchyma or vasculature of the lungs. Mortality from ALI/ARDS is substantial, and current therapy primarily emphasizes mechanical ventilation and judicial fluid management plus standard treatment of the initiating insult and any known underlying disease. Current pharmacotherapy for ALI/ARDS is not optimal, and there is a significant need for more effective medicinal chemical agents for use in these severe and lethal lung injury syndromes. To facilitate future chemical-based drug discovery research on new agent development, this paper reviews present pharmacotherapy for ALI/ARDS in the context of biological and biochemical drug activities. The complex lung injury pathophysiology of ALI/ARDS offers an array of possible targets for drug therapy, including inflammation, cell and tissue injury, vascular dysfunction, surfactant dysfunction, and oxidant injury. Added targets for pharmacotherapy outside the lungs may also be present, since multiorgan or systemic pathology is common in ALI/ARDS. The biological and physiological complexity of ALI/ARDS requires the consideration of combined-agent treatments in addition to single-agent therapies. A number of pharmacologic agents have been studied individually in ALI/ARDS, with limited or minimal success in improving survival. However, many of these agents have complementary biological/biochemical activities with the potential for synergy or additivity in combination therapy as discussed in this article.
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Affiliation(s)
- Krishnan Raghavendran
- Department of Surgery, State University of New York (SUNY) at Buffalo, Buffalo, NY 14214, USA.
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Wang Z, Schwab U, Rhoades E, Chess PR, Russell DG, Notter RH. Peripheral cell wall lipids of Mycobacterium tuberculosis are inhibitory to surfactant function. Tuberculosis (Edinb) 2007; 88:178-86. [PMID: 18155644 DOI: 10.1016/j.tube.2007.11.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2007] [Revised: 11/07/2007] [Accepted: 11/12/2007] [Indexed: 10/22/2022]
Abstract
The transmission of Mycobacterium tuberculosis (TB) requires extensive damage to the lungs to facilitate bacterial release into the airways, and it is therefore likely that the microorganism has evolved mechanisms to exacerbate its local pathology. This study examines the inhibitory effects of lipids extracted and purified chromatographically from TB on the surface-active function of lavaged bovine lung surfactant (LS) and a clinically relevant calf lung surfactant extract (CLSE). Total lipids from TB greatly inhibited the surface activity of LS and CLSE on the pulsating bubble surfactometer at physical conditions applicable for respiration in vivo (37 degrees C, 20 cycles/min, 50% area compression). Minimum surface tensions for LS (0.5 mg/ml) and CLSE (1 mg/ml) were raised from <1 mN/m to 15.7+/-1.2 and 18.7+/-1.3 mN/m after 5 min of bubble pulsation in the presence of total TB lipids (0.15 mg/ml). TB mixed waxes (0.15 mg/ml) and TB trehalose monomycolates (TMMs, 0.15 mg/ml) also significantly inhibited the surface activity of LS and CLSE (minimum surface tensions of 10-16 mN/m after 5 min of bubble pulsation), as did purified trehalose 6,6'-dimycolate (TDM, cord factor). Phosphatidylinositol mannosides (PIMs, 0.15 mg/ml) from TB had no inhibitory effect on the surface activity of LS or CLSE. Concentration dependence studies showed that LS was also inhibited significantly by total TB lipids at 0.075 mg/ml, with a smaller activity decrease apparent even at 0.00375 mg/ml. These findings document that TB contains multiple lipids that can directly impair the biophysical function of endogenous and exogenous lung surfactants. Direct inhibition by TB lipids could worsen surfactant dysfunction caused by plasma proteins or other endogenous substances induced by inflammatory injury in the infected lungs. TB lipids could also inhibit the effectiveness of exogenous surfactants used to treat severe acute respiratory failure in TB patients meeting criteria for clinical acute lung injury (ALI) or the acute respiratory distress syndrome (ARDS).
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Affiliation(s)
- Zhengdong Wang
- Department of Pediatrics, University of Rochester School of Medicine, Box 850, 601 Elmwood Avenue, Rochester, NY 14642, USA
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Lazarov S, Yanev E, Momchilova A, Markovska T, Ivanova L, Pankov R. Alterations of the composition and metabolism of pulmonary surfactant phospholipids induced by experimental peritonitis in rats. Chem Biol Interact 2007; 169:73-9. [PMID: 17597597 DOI: 10.1016/j.cbi.2007.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2007] [Revised: 05/15/2007] [Accepted: 05/22/2007] [Indexed: 01/11/2023]
Abstract
Pulmonary complications often accompany the development of acute peritonitis. In this study, we analyzed the alterations of alveolar surfactant phospholipids in rats with experimentally induced peritonitis. The results showed a reduction of almost all phospholipid fractions in pulmonary surfactant of experimental animals. The most abundant alveolar phospholipids-phosphatidylcholine and phosphatidylglycerol were reduced significantly in surfactant of rats with experimental peritonitis. In addition, analysis of the fatty acid composition of these two phospholipids revealed marked differences between experimental and control animals. The activity of phospholipase A2, which is localized in the hydrophyllic phase of alveolar surfactant, was higher in rats with experimental peritonitis compared to sham-operated ones. Also, a weak acyl-CoA:lysophospholipid acyltransferase activity was detected in alveolar surfactant of rats with experimental peritonitis, whereas in control animals this activity was not detectable. The lipid-transfer activity was quite similar in pulmonary surfactant of control and experimental rats. The total number of cells and the percentage of neutrophils were strongly increased in broncho-alveolar lavage fluid from rats with peritonitis. Thus, our results showed that the development of peritonitis was accompanied by pulmonary pathophysiological processes that involved alterations of the phospholipid and fatty acid composition of alveolar surfactant. We suggest that the increased populations of inflammatory cells, which basically participate in internalization and secretion of surfactant components, contributed to the observed alterations of alveolar phospholipids. These studies would be useful for clarification of the pathogenic mechanisms underlying the occurrence of pulmonary disorders that accompany acute inflammatory conditions, such as peritonitis and sepsis.
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Affiliation(s)
- Simeon Lazarov
- Department of Pathophysiology, Medical University, 1431 Sofia, Bulgaria
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Verbrugge SJC, Lachmann B, Kesecioglu J. Lung protective ventilatory strategies in acute lung injury and acute respiratory distress syndrome: from experimental findings to clinical application. Clin Physiol Funct Imaging 2007; 27:67-90. [PMID: 17309528 DOI: 10.1111/j.1475-097x.2007.00722.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This review addresses the physiological background and the current status of evidence regarding ventilator-induced lung injury and lung protective strategies. Lung protective ventilatory strategies have been shown to reduce mortality from adult respiratory distress syndrome (ARDS). We review the latest knowledge on the progression of lung injury by mechanical ventilation and correlate the findings of experimental work with results from clinical studies. We describe the experimental and clinical evidence of the effect of lung protective ventilatory strategies and open lung strategies on the progression of lung injury and current controversies surrounding these subjects. We describe a rational strategy, the open lung strategy, to accomplish an open lung, which may further prevent injury caused by mechanical ventilation. Finally, the clinician is offered directions on lung protective ventilation in the early phase of ARDS which can be applied on the intensive care unit.
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Affiliation(s)
- Serge J C Verbrugge
- Department of Intensive Care Medicine, University Medical Center Utrecht, Utrecht, The Netherlands.
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Peres e Serra A, Parra ER, Eher E, Capelozzi VL. Nonhomogeneous immunostaining of hyaline membranes in different manifestations of diffuse alveolar damage. Clinics (Sao Paulo) 2006; 61:497-502. [PMID: 17187083 DOI: 10.1590/s1807-59322006000600002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2006] [Accepted: 07/18/2006] [Indexed: 11/22/2022] Open
Abstract
PURPOSE To determine the nature of hyaline membranes in different manifestations of diffuse alveolar damage, [pulmonary and extrapulmonary acute respiratory distress syndrome], and idiopathic [acute interstitial pneumonia]. MATERIALS AND METHODS Pulmonary specimens were obtained from 17 patients with acute respiratory distress syndrome and 9 patients with acute interstitial pneumonia. They were separated into 3 different groups: (a) pulmonary diffuse alveolar damage (pDAD) (n = 8), consisting only of pneumonia cases; (b) extrapulmonary diffuse alveolar damage (expDAI) (n = 9), consisting of sepsis and septic shock cases; and (c) idiopathic diffuse alveolar damage (iDAD) (n = 9), consisting of idiopathic cases (acute interstitial pneumonia). Hyaline membranes, the hallmark of the diffuse alveolar damage histological pattern, were examined using various kinds of antibodies. The antibodies used were against surfactant apoprotein-A (SP-A), cytokeratin 7 (CK7), cytokeratin 8 (CK8), alpha smooth muscle actin (alpha-SMA), cytokeratin AE1/AE3 (AE1/AE3), and factor VIII-related antigen (factor VIII). RESULTS Pulmonary diffuse alveolar damage showed the largest quantity of hyaline membranes (12.65% +/- 3.24%), while extrapulmonary diffuse alveolar damage (9.52% +/- 3.64%) and idiopathic diffuse alveolar damage (7.34% +/- 2.11%) showed intermediate and lower amounts, respectively, with the difference being statistically significant between pulmonary and idiopathic diffuse alveolar damage (P < 0.05). No significant difference was found for hyaline membranes Sp-A immunostaining among pulmonary (15.36% +/- 3.12%), extrapulmonary (16.12% +/- 4.58%), and idiopathic (13.74 +/- 4.20%) diffuse alveolar damage groups. Regarding factor VIII, we found that idiopathic diffuse alveolar damage presented larger amounts of immunostained hyaline membranes (14.12% +/- 6.25%) than extrapulmonary diffuse alveolar damage (3.93% +/- 2.86%), with this difference being statistically significant (P < 0.001). Equally significant was the difference for progressive decrease of cytokeratin AE1/AE3 immunostaining in hyaline membranes present in the extrapulmonary diffuse alveolar damage (5.42% +/- 2.80%) and idiopathic diffuse alveolar damage (0.47% +/- 0.81%) groups (P < 0.001). None of the groups stained for cytokeratin CK-7, CK-8, vimentin, or a anti-smooth muscle actin. CONCLUSIONS This study showed that only the epithelial/endothelial components (SP-A, factor VIII, and AE1/AE3) of the alveolar/capillary barrier are present in hyaline membranes formation in the 3 groups of patients with diffuse alveolar damage. The significant difference in the expression of factor VIII-related antigen and cytokeratin AE1/AE3 in the expDA versus iDAD groups as well as the significant difference in the amount of hyaline membranes present in the pDAD versus iDAD groups are suggestive of a local and specific lesion with different pathways (direct, indirect, or idiopathic), depending on the type of diffuse alveolar damage.
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Affiliation(s)
- André Peres e Serra
- Department of Pathology, São Paulo University Medical School, São Paulo, SP, Brazil
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Serrano AG, Pérez-Gil J. Protein-lipid interactions and surface activity in the pulmonary surfactant system. Chem Phys Lipids 2006; 141:105-18. [PMID: 16600200 DOI: 10.1016/j.chemphyslip.2006.02.017] [Citation(s) in RCA: 220] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2005] [Accepted: 02/20/2006] [Indexed: 11/30/2022]
Abstract
Pulmonary surfactant is a lipid-protein complex, synthesized and secreted by the respiratory epithelium of lungs to the alveolar spaces, whose main function is to reduce the surface tension at the air-liquid interface to minimize the work of breathing. The activity of surfactant at the alveoli involves three main processes: (i) transfer of surface active molecules from the aqueous hypophase into the interface, (ii) surface tension reduction to values close to 0 mN/m during compression at expiration and (iii) re-extension of the surface active film upon expansion at inspiration. Phospholipids are the main surface active components of pulmonary surfactant, but the dynamic behaviour of phospholipids along the breathing cycle requires the necessary participation of some specific surfactant associated proteins. The present review summarizes the current knowledge on the structure, disposition and lipid-protein interactions of the hydrophobic surfactant proteins SP-B and SP-C, the two main actors participating in the surface properties of pulmonary surfactant. Some of the methodologies currently used to evaluate the surface activity of the proteins in lipid-protein surfactant preparations are also revised. Working models for the potential molecular mechanism of SP-B and SP-C are finally discussed. SP-B might act in surfactant as a sort of amphipathic tag, directing the lipid-protein complexes to insert and re-insert very efficiently into the air-liquid interface along successive breathing cycles. SP-C could be essential to maintain association of lipid-protein complexes with the interface at the highest compressed states, at the end of exhalation. The understanding of the mechanisms of action of these proteins is critical to approach the design and development of new clinical surfactant preparations for therapeutical applications.
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Affiliation(s)
- Alicia G Serrano
- Departamento de Bioquímica y Biología Molecular I, Facultad de Biología, Universidad Complutense, Jose Antonio Novais 2, Madrid, Spain
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Dehority W, Lu KW, Clements J, Goerke J, Pittet JF, Allen L, Taeusch HW. Polyethylene glycol-surfactant for lavage lung injury in rats. Pediatr Res 2005; 58:913-8. [PMID: 16183815 DOI: 10.1203/01.pdr.0000182581.39561.01] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Addition of ionic and nonionic water-soluble polymers to pulmonary surfactants in the presence of inactivating substances prevents surfactant inactivation in vitro and improves lung function in several models of lung injury. However, a recent report found opposite effects when surfactant plus polyethylene glycol (PEG) was used to treat lung injury caused by saline lung lavage. Therefore, we examined the reasons why the polymer effect is less evident in the saline lung lavage lung injury model. We treated rats with lavage lung injury with a commercial lung surfactant extract derived from bovine lung (Survanta) with or without addition of PEG. Groups treated with Survanta + PEG had significantly higher static post mortem lung volumes than groups treated with Survanta. However, groups treated with Survanta + PEG had more tracheal fluid and no significant benefit in arterial oxygenation compared with the group treated with Survanta, despite our use of measures to reduce pulmonary edema. Measurements after intravascular injections of (125)I-labeled albumin confirmed that addition of PEG increased extravascular lung water and that this effect is mitigated by furosemide. We conclude that surfactant + PEG mixtures are less effective in lavage injury than in other forms of lung injury because of increased extravascular lung water.
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Affiliation(s)
- Walter Dehority
- Department of Pediatrics, San Francisco General Hospital/University of California-San Francisco, San Francisco, California 94110, USA
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Wang Z, Foye A, Chang Y, Chess PR, Wright TW, Bhagwat S, Gigliotti F, Notter RH. Inhibition of surfactant activity by Pneumocystis carinii organisms and components in vitro. Am J Physiol Lung Cell Mol Physiol 2005; 288:L1124-31. [PMID: 15886399 DOI: 10.1152/ajplung.00453.2004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study examines the direct inhibitory effects of Pneumocystis carinii (Pc) organisms and chemical components on the surface activity and composition of whole calf lung surfactant (WLS) and calf lung surfactant extract (CLSE) in vitro. Incubation of WLS suspensions with intact Pc organisms (10(7) per milligram of surfactant phospholipid) did not significantly alter total phospholipid levels or surfactant protein A content. Incubation with intact Pc organisms also did not impair dynamic surface tension lowering in suspensions of WLS or centrifuged large surfactant aggregates on a bubble surfactometer (37 degrees C, 20 cycles/min, 0.5 and 2.5 mg phospholipid/ml). However, exposure of WLS or CLSE to disrupted (sonicated) Pc organisms led to severe detriments in activity, with minimum surface tensions of 17-19 mN/m vs. <1 mN/m for surfactants alone. Extracted hydrophobic chemical components from Pc (98.8% lipids, 0.1 mM) reduced the surface activity of WLS and CLSE similarly to sonicated Pc organisms, whereas extracted hydrophilic chemical components from Pc (primarily proteins) had only minor effects on surface tension lowering. These results indicate that in addition to surfactant dysfunction induced by inflammatory lung injury and edema-derived inhibitors in Pc pneumonia, disrupted Pc organisms in the alveolar lumen also have the potential to directly inhibit endogenous and exogenous lung surfactants in affected patients.
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Affiliation(s)
- Zhengdong Wang
- Dept. of Pediatrics, Box 850, Univ. of Rochester School of Medicine, 601 Elmwood Ave., Rochester, NY 14642, USA
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Davidson BA, Knight PR, Wang Z, Chess PR, Holm BA, Russo TA, Hutson A, Notter RH. Surfactant alterations in acute inflammatory lung injury from aspiration of acid and gastric particulates. Am J Physiol Lung Cell Mol Physiol 2005; 288:L699-708. [PMID: 15757954 DOI: 10.1152/ajplung.00229.2004] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
This study examines surfactant dysfunction in rats with inflammatory lung injury from intratracheal instillation of hydrochloric acid (ACID, pH 1.25), small nonacidified gastric particles (SNAP), or combined acid and small gastric particles (CASP). Rats given CASP had the most severe lung injury at 6, 24, and 48 h based on decreases in arterial oxygenation and increases in erythrocytes, total leukocytes, neutrophils, total protein, and albumin in bronchoalveolar lavage (BAL). The content of large surfactant aggregates in BAL was reduced in all forms of aspiration injury, but decreases were greatest in rats given CASP. Large aggregates from aspiration-injured rats also had decreased levels of phosphatidylcholine (PC) and increased levels of lyso-PC and total protein compared with saline controls (abnormalities for CASP were greater than for SNAP or ACID alone). The surface tension-lowering ability of large surfactant aggregates on a bubble surfactometer was impaired in rats with aspiration injury at 6, 24, and 48 h, with the largest activity reductions found in animals given CASP. There were strong statistical correlations between surfactant dysfunction (increased minimum surface tension and reduced large aggregate content) and the severity of lung injury based on arterial oxygenation and levels of albumin, protein, and erythrocytes in BAL (P < 0.0001). Surfactant dysfunction also correlated strongly with reduced lung volumes during inflation and deflation (P = 0.0004-0.005). These results indicate that surfactant abnormalities are functionally important in gastric aspiration lung injury and contribute significantly to the increased severity of injury found in CASP compared with ACID or SNAP alone.
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Affiliation(s)
- Bruce A Davidson
- Departments of Anesthesiology,University at Buffalo-State University of New York, Buffalo, NY 14214, USA
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Nishina K, Mikawa K, Takao Y, Obara H. The Efficacy of Fluorocarbon, Surfactant, and Their Combination for Improving Acute Lung Injury Induced by Intratracheal Acidified Infant Formula. Anesth Analg 2005; 100:964-971. [PMID: 15781507 DOI: 10.1213/01.ane.0000146438.87584.a9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We conducted the current study to compare the efficacy of partial liquid ventilation (PLV), pulmonary surfactant (PSF), and their combination in ameliorating the acidified infant-formula-induced acute lung injury (ALI). In the Part I study, 42 rabbits receiving volume-controlled ventilation with positive end-expiratory pressure 10 cm H(2)O were randomly divided into 6 groups (groups noninjuryI, gas ventilation [GVi], PLVi, PSFi, PLVi-->PSFi, and PSFi-->PLVi). ALI was induced by intratracheal acidified infant formula (2 mL/kg, pH 1.8). Group GVi received neither PLV nor PSF therapy. Groups PLV and PSF received intratracheal fluorocarbon 15 mL/kg or surfactant 100 mg/kg, respectively, 30 min after acidified infant formula. Groups PLVi-->PSFi and PSFi-->PLVi received both treatments at 30-min intervals. In Part II, 42 rabbits (in 6 groups) undergoing pressure-controlled ventilation received the same drug therapies as in Part I. The lungs were excised to assess biochemical and histological damage 150 min after induction of ALI. In Parts I and II, PSF, fluorocarbon, and their combination attenuated lung leukosequestration and edema and superoxide production of neutrophils, consequently improving oxygenation, lung mechanics, and pathological changes. Independent of ventilation mode, PSF followed by fluorocarbon provided the most beneficial effects and fluorocarbon followed by PSF produced the least efficacy.
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Affiliation(s)
- Kahoru Nishina
- Department of Anesthesia & Perioperative Medicine, Faculty of Medical Sciences, Kobe University Graduate School of Medicine, Kobe, Japan
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Hermon MM, Wassermann E, Pfeiler C, Pollak A, Redl H, Strohmaier W. EARLY MECHANICAL VENTILATION IS DELETERIOUS AFTER ASPIRATION-INDUCED LUNG INJURY IN RABBITS. Shock 2005; 23:59-64. [PMID: 15614133 DOI: 10.1097/01.shk.0000143417.28273.6d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We investigated whether mechanical ventilation after aspiration is deleterious when started before surfactant therapy. Gas exchange and lung mechanics were measured in rabbits after aspiration either mechanically ventilated before or after lavage with diluted surfactant or Ringer's solution. Lung injury was induced by intratracheal instillation of 2 mL/kg of a betain/HCl pepsin mixture. After 30 min of spontaneous breathing, ventilation was started in 12 rabbits, which were then treated by lavage with diluted surfactant (15 mL/kg body weight; 5.3 mg/mL, group MVpre S) or with Ringer's solution (1 mL/kg; group MVpre R). Another 12 rabbits were treated by lavage while spontaneously breathing and were then connected to the ventilator (MVpost S and MVpost R). Sham control rabbits were mechanically ventilated for 4 h. At the end of experiment, PaO2/FiO2 ratio in MVpost S was five times higher than in MVpre S (P=0.0043). Lung mechanics measurements showed significant difference between MVpre S and MVpost S (P=0.0072). There was histopathologic evidence of decreased lung injury in MVpost S. Immediate initiation of ventilation is harmful when lung injury is induced by aspiration. Further investigations are needed to clarify whether the timing of lavage with diluted surfactant has an impact on the treatment of patients with aspiration or comparable types of direct lung injury.
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Affiliation(s)
- Michael M Hermon
- Division of Neonatology and Pediatric Intensive Care, University Children's Hospital, Medical University of Vienna, Austria.
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Xu Y, Kobayashi T, Cui X, Ohta K, Kabata C, Tashiro K. Lung volumes and alveolar expansion pattern in immature rabbits treated with serum-diluted surfactant. J Appl Physiol (1985) 2004; 97:1408-13. [PMID: 15358752 DOI: 10.1152/japplphysiol.01043.2003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In acute respiratory distress syndrome, mechanical ventilation often induces alveolar overdistension aggravating the primary insult. To examine the mechanism of overdistension, surfactant-deficient immature rabbits were anesthetized with pentobarbital sodium, and their lungs were treated with serum-diluted modified natural surfactant (porcine lung extract; 2 mg/ml, 10 ml/kg). By mechanical ventilation with a peak inspiration pressure of 22.5 cm H2O, the animals had a tidal volume of 14.7 ml/kg (mean), when 2.5 cm H2O positive end-expiratory pressure was added. This volume was similar to that in animals treated with nondiluted modified natural surfactant (24 mg/ml in Ringer solution, 10 ml/kg). However, the lungs fixed at 10 cm H2O on the deflation limbs of the pressure-volume curve had the largest alveolar/alveolar duct profiles (> or =48,000 microm2), accounting for 38% of the terminal air spaces, and the smallest (<6,000 microm2), accounting for 31%. These values were higher than those in animals treated with nondiluted modified natural surfactant (P <0.05). We conclude that administration of serum-diluted surfactant to immature neonatal lungs leads to patchy overdistension of terminal air spaces, similar to the expansion pattern that may be seen after dilution of endogenous surfactant with proteinaceous edema fluid in acute respiratory distress syndrome.
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Affiliation(s)
- Yongmei Xu
- Dept. of Anesthesiology and Intensive Care Medicine, Graduate School of Medical Science, Kanazawa Univ., Kanazawa 920-8641, Japan
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Quasney MW, Waterer GW, Dahmer MK, Kron GK, Zhang Q, Kessler LA, Wunderink RG. Association between surfactant protein B + 1580 polymorphism and the risk of respiratory failure in adults with community-acquired pneumonia. Crit Care Med 2004; 32:1115-9. [PMID: 15190959 DOI: 10.1097/01.ccm.0000124872.55243.5a] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Pulmonary surfactant protein (SP)-B plays a vital role in the formation and function of surfactant in the lung. A genetic polymorphism (SP-B + 1580) is postulated to result in diminished activity of SP-B. The objective was to determine whether the SP-B + 1580 CC genotype is associated with an increased risk of respiratory failure and ARDS in adults with community-acquired pneumonia. DESIGN Prospective cohort of adults diagnosed with community-acquired pneumonia. SETTING Hospital system. PATIENTS We enrolled 402 adults > or = 18 yrs of age with community-acquired pneumonia; 158 were white, 243 were African American, and one was Asian. INTERVENTIONS Genotypic analysis was performed on DNA isolated from whole blood using polymerase chain reaction amplification and DdeI restriction enzyme digestion. MEASUREMENTS AND MAIN RESULTS We recorded the requirement for mechanical ventilation, the presence of acute respiratory distress syndrome (ARDS) or septic shock, and mortality. Sixty-three patients required mechanical ventilation, 12 patients developed ARDS, and 35 patients developed septic shock. Genotypic frequencies at the SP-B + 1580 site were T/T 183 of 402 (0.45), T/C 160 of 402 (0.40), and C/C 59 of 402 (0.15). Of the 59 patients who were C/C at the SP-B + 1580 site, 21 (0.356) required mechanical ventilation, compared with 26 of 160 patients (0.163) who were T/C and 16 of 183 (0.087) patients who were T/T (p < .001). ARDS developed in five of 59 (0.085) patients with the C/C genotype, compared with six of 160 (.038) patients with T/C and one of 183 patients with T/T (0.005, p < .009). Septic shock occurred in 12 of 59 (0.203) patients with the C/C genotype, compared with 13 of 160 (0.081) patients with T/C and ten of 183 (0.055) patients with T/T (p < .001). Mortality rate was not different between the three genotypes. CONCLUSION Carriage of the C allele at the SP-B + 1580 site is associated with ARDS, septic shock, and the need for mechanical ventilation in adults with community-acquired pneumonia.
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Affiliation(s)
- Michael W Quasney
- Division of Critical Care, Department of Pediatrics, University of Tennessee, Memphis, Children's Foundation Research Center of Memphis, Le Bonheur Children's Medical Center, 50 N. Dunlap, Memphis, TN 38103, USA.
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Huang T, Uyehara C, Balaraman V, Miyasato C, Person D, Egan E, Easa D. Surfactant lavage with lidocaine improves pulmonary function in piglets after HCl-induced acute lung injury. Lung 2004; 182:15-25. [PMID: 14752669 PMCID: PMC1415270 DOI: 10.1007/s00408-003-1041-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/07/2003] [Indexed: 01/11/2023]
Abstract
Acute respiratory distress syndrome (ARDS) is associated with significant morbidity and mortality. The pathophysiology of ARDS includes abnormalities of surfactant function as well as pulmonary inflammation. Immunomodulating drugs, like Lidocaine, have shown some success in decreasing inflammation in ARDS. We attempted to combine surfactant lavage's ability to reverse the surfactant dysfunction, while acting as a vehicle to deliver Lidocaine. Gravity-driven surfactant (Infasurf) lavage (35 ml/kg) was administered alone or mixed with Lidocaine after severe HCl acid injury (0.3 N; 3 cc/kg) in neonatal piglets. Treatment groups included: control (C) ( n = 5), surfactant lavage (SL) (35 ml/kg-diluted Infasurf) ( n = 7) and SL mixed with Lidocaine (SL+L) ( n = 7). About 26-27% of the lavage was retained (phospholipid 73-74 mg/kg; Lidocaine 1.8 mg/kg). Oxygenation progressively increased in the SL and SL+L groups over the 4-hour period (at 240 min: C = 99 +/- 14; SL = 154 +/- 39; SL+L = 230 +/- 40 mmHg) ( p < 0.05). PaCO(2) increased in all groups from 43 +/- 0.3 to 55 +/- 0.7 mmHg. Only SL+L showed a reduction in PaCO(2) (at 240 min: C = 54 +/- 4; SL = 53 +/- 7; SL+L = 49 +/- 2 mmHg) ( p < 0.05). Finally, SL and SL + L had superior characteristics during the quasi-static pressure volume (PV) procedure as compared to Control ( p < 0.05). In our HCl ALI model, SL improved oxygenation and quasi-static lung compliance over C. The pulmonary function effects of SL were further enhanced by the addition of Lidocaine to the surfactant suspension. Combining therapeutic agents with surfactant lavage may be an effective strategy in ALI.
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Affiliation(s)
- T.K. Huang
- Department of Clinical Investigation, Tripler Army Medical Center, TAMC, Honolulu, Hawaii 96826, USA
| | - C.F.T. Uyehara
- Department of Clinical Investigation, Tripler Army Medical Center, TAMC, Honolulu, Hawaii 96826, USA
| | - V. Balaraman
- Department of Pediatrics, John A. Burns School of Medicine, University of Hawaii and Kapiolani Medical Center, Honolulu, Hawaii 96826, USA
| | - C.Y. Miyasato
- Department of Clinical Investigation, Tripler Army Medical Center, TAMC, Honolulu, Hawaii 96826, USA
| | - D. Person
- Department of Clinical Investigation, Tripler Army Medical Center, TAMC, Honolulu, Hawaii 96826, USA
| | - E. Egan
- Department of Pediatrics and Physiology, University of Buffalo, State University of New York, Buffalo, New York, USA
| | - D. Easa
- Department of Clinical Investigation, Tripler Army Medical Center, TAMC, Honolulu, Hawaii 96826, USA
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Mikawa K, Nishina K, Takao Y, Obara H. Intratracheal Application of Recombinant Surfactant Protein-C Surfactant to Rabbits Attenuates Acute Lung Injury Induced by Intratracheal Acidified Infant Formula. Anesth Analg 2004; 98:1273-9, table of contents. [PMID: 15105199 DOI: 10.1213/01.ane.0000111111.76779.b3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
UNLABELLED Our aim in the current study was to determine whether recombinant surfactant protein-C (rSP-C) surfactant improves acute lung injury (ALI) induced by intratracheal acidified milk products. Twenty-eight rabbits were randomly divided into four groups. ALI was induced with intratracheal acidified infant formula (0.8 mL/kg, pH 1.8) in 3 groups. The control group received intratracheal acidified saline. Therapy groups received 1 of 2 doses of intratracheal rSP-C surfactant (0.5 or 2 SP-C mg/kg) 30 min after the acidified infant formula. The lungs were ventilated with 100% oxygen for 4 h after induction of ALI. Acidified infant formula dramatically reduced oxygenation and lung compliance, and increased resistance. Both doses of rSP-C improved the variables [mean PaO(2) (mm Hg) and compliance (mL/cm H(2)O) at 4 h: 61 and 0.4 for infant formula, 162 and 1.0 for small-dose rSP-C, and 152 and 1.2 for large-dose rSP-C, respectively; P < 0.05]. Pulmonary leukosequestration and edema, and severe morphological changes were attenuated by rSP-C treatment (ALI score: 14, 7, 7 in infant formula, small-dose rSP-C, and large-dose rSP-C; P < 0.05). The efficacy was similar for the two doses of rSP-C. These findings suggest that intratracheal administration of rSP-C ameliorates ALI induced by aspiration of acidified milk products. IMPLICATIONS Small or large doses of recombinant surfactant protein-C surfactant given 30 min after intratracheal acidified infant formula attenuated physiological, biochemical, and morphological lung damage.
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Affiliation(s)
- Katsuya Mikawa
- Department of Anesthesia and Perioperative Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
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Mikawa K, Nishina K, Takao Y, Obara H. Efficacy of partial liquid ventilation in improving acute lung injury induced by intratracheal acidified infant formula: determination of optimal dose and positive end-expiratory pressure level. Crit Care Med 2004; 32:209-16. [PMID: 14707581 DOI: 10.1097/01.ccm.0000104954.22016.d2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Partial liquid ventilation with fluorocarbon was successfully used for acute lung injury induced by oleic acid or lung lavage. Positive end-expiratory pressure (PEEP) during partial liquid ventilation enhances the efficacy of fluorocarbon. The aim of the current study was to assess whether partial liquid ventilation can repair lung damage induced by intratracheal acidified infant formula and to determine the optimal fluorocarbon dose and PEEP level. DESIGN Prospective, randomized animal study. SETTING University research laboratory. SETTING AND SUBJECTS Seventy-six male anesthetized rabbits. INTERVENTIONS For study 1, acute lung injury was induced by intratracheal acidified infant formula in four groups. Next, three groups received 10, 15, or 20 mL/kg fluorocarbon, and the fourth group was conventionally gas ventilated. For study 2, acute lung injury was induced in five groups. One group was gas ventilated at a PEEP of 5 cm H2O, whereas the other four groups received fluorocarbon (15 mL/kg) and were assigned to one of four PEEP levels (5, 7.5, 10, or 12.5 cm H2O). The lungs were ventilated with 100% oxygen for 4 hrs after acute lung injury. MEASUREMENTS AND MAIN RESULTS In study 1, fluorocarbon at doses of 15 and 20 mL/kg attenuated lung leukosequestration and edema and superoxide production of neutrophils, resulting in similar improvements in oxygenation, lung mechanics, and pathologic changes. The highest fluorocarbon dose caused mortality from pneumothorax. In study 2, the combination of PEEP with partial liquid ventilation improved gas exchange, lung compliance, pulmonary edema, and histologically observed damage. The beneficial effects of PEEP at 10 and 12.5 cm H2O were similar. Adverse side effects of 12.5 cm H2O PEEP included pneumothorax and hemodynamic instability. CONCLUSIONS The combination of fluorocarbon and PEEP improved the physiologic, biochemical, and histologic lung injury induced by acidified infant formula. The beneficial effects of partial liquid ventilation are due, in part, to inhibition of pulmonary neutrophil accumulation and activation with fluorocarbon. The optimal fluorocarbon dose and PEEP level in our model were 15 mL/kg and 10 cm H2O, respectively.
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Affiliation(s)
- Katsuya Mikawa
- Department of Anesthesia and Perioperative Medicine, Faculty of Medical Sciences, Kobe University Graduate School of Medicine, Japan.
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Buccoliero R, Ginzburg L, Futerman AH. Elevation of lung surfactant phosphatidylcholine in mouse models of Sandhoff and of Niemann-Pick A disease. J Inherit Metab Dis 2004; 27:641-8. [PMID: 15669680 DOI: 10.1023/b:boli.0000042958.22066.6c] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Sandhoff disease is caused by the defective activity of the lysosomal enzyme beta-hexosaminidase, resulting in accumulation of the glycolipids, GA2 and GM2. Niemann-Pick A/B disease is caused by the defective activity of lysosomal acid sphingomyelinase resulting in sphingomyelin accumulation. Pulmonary complications have been observed in both diseases. We now demonstrate changes in phospholipid levels in pulmonary surfactant in mouse models of these diseases. In the Hexb mouse, a model of Sandhoff disease, lipid phosphate levels were elevated in surfactant from 3- and 4-month-old mice, which was mainly due to elevated levels of phosphatidylcholine. In the ASM mouse, a model of Niemann-Pick A disease, levels of the primary storage material, sphingomyelin, were elevated as expected, and levels of phosphatidylcholine and two other phospholipids were also significantly elevated in pulmonary surfactant and in lung tissue from 5-, 6- and 7-month-old mice. These results suggest that changes in phospholipid levels and composition in lung surfactant might be a general feature of sphingolipid storage diseases, which may be in part responsible for the increased susceptibility of these patients to respiratory infections and lung pathology, often the main reason for the death of these patients.
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Affiliation(s)
- R Buccoliero
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel
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Markart P, Ruppert C, Grimminger F, Seeger W, Günther A. Fibrinolysis-inhibitory capacity of clot-embedded surfactant is enhanced by SP-B and SP-C. Am J Physiol Lung Cell Mol Physiol 2003; 284:L69-76. [PMID: 12388357 DOI: 10.1152/ajplung.00037.2002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Incorporation of pulmonary surfactant into fibrin inhibits its plasmic degradation. In the present study we investigated the influence of surfactant proteins (SP)-A, SP-B, and SP-C on the fibrinolysis-inhibitory capacity of surfactant phospholipids. Plasmin-induced fibrinolysis was quantified by means of a (125)I-fibrin plate assay, and surfactant incorporation into polymerizing fibrin was analyzed by measuring the incorporation of (3)H-labeled L-alpha-dipalmitoylphosphatidylcholine into the insoluble clot material. Incorporation of a calf lung surfactant extract (Alveofact) and an organic extract of natural rabbit large surfactant aggregates (LSA) into a fibrin clot revealed a stronger inhibitory effect on plasmic cleavage of this clot than a synthetic phospholipid mixture (PLX) and unprocessed LSA. Reconstitution of PLX with SP-B and SP-C increased, whereas reconstitution with SP-A decreased, the fibrinolysis-inhibitory capacity of the phospholipids. The SP-B effect was paralleled by an increased incorporation of phospholipids into fibrin. We conclude that the inhibitory effect of surfactant incorporation into polymerizing fibrin on its susceptibility to plasmic cleavage is enhanced by SP-B and SP-C but reduced by SP-A. In the case of SP-B, increased phospholipid incorporation may underlie this finding.
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Affiliation(s)
- Philipp Markart
- Department of Internal Medicine, Justus-Liebig-University-Giessen, Klinikstrasse 36, D-35385 Giessen, Germany
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Mander A, Langton-Hewer S, Bernhard W, Warner JO, Postle AD. Altered phospholipid composition and aggregate structure of lung surfactant is associated with impaired lung function in young children with respiratory infections. Am J Respir Cell Mol Biol 2002; 27:714-21. [PMID: 12444031 DOI: 10.1165/rcmb.4746] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Alterations to pulmonary surfactant structure, composition, and function contribute to the severity of respiratory infections. Analysis of bronchoalveolar lavage fluid (BALF) from children undergoing diagnostic bronchoscopy for structural abnormalities (control group, n = 24), asthma (n = 18), lung infection (n = 30), and cystic fibrosis (CF, n = 15) showed that BALF phospholipid concentration decreased with age for the control group and was elevated in all disease groups. The fractional concentration of the major surface active component, dipalmitoyl phosphatidylcholine (PC16:0/16:0), correlated (r(2) = 0.608, P < 0.01) with airway resistance (FEV(1%) predicted), and decreased PC16:0/16:0 was accompanied by increased concentrations of phospholipid components characteristic of cell membranes (PC16:0/18:1 and PI18:0/20:4). Median minimal surface tension, measured by pulsating bubble surfactometer, was elevated (P < 0.01) in both infection (17.5 mN/m) and CF (17.1 mN/m) compared with the control group (1.5 mN/m). Centrifugation (60,000 x g, 40 min) of BALF indicated that infection was accompanied by accumulation of large aggregate forms of surfactant, in contrast to previous reports of increased conversion to inactive small aggregate surfactant particles in ventilated patients with respiratory failure. This accumulation of surface-inactive, large aggregate forms of surfactant, possibly due to mixing with membrane material from inflammatory cells, may contribute to severity of lung disease in children with respiratory infections.
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Affiliation(s)
- Ann Mander
- Child Health, Infection Inflammation and Repair Division, School of Medicine, Southampton General Hospital, Southampton, UK
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Lu KW, Taeusch HW, Robertson B, Goerke J, Clements JA. Polyethylene glycol/surfactant mixtures improve lung function after HCl and endotoxin lung injuries. Am J Respir Crit Care Med 2001; 164:1531-6. [PMID: 11704608 DOI: 10.1164/ajrccm.164.8.2104016] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Addition of nonionic polymers such as polyethylene glycol (PEG) and dextran ameliorates inactivation of Survanta by a variety of substances in vitro. Addition of polymers to Survanta also improves pulmonary function when used to treat rats with lung injury caused by instillation of human meconium. To find whether this approach is effective in lung injuries that more closely resemble adult respiratory distress syndrome (ARDS), we have compared the use of Survanta with Survanta + PEG in two additional models of lung injury caused by either lipopolysaccharide (LPS) or HCl in adult rats. Significant improvement of serial measures for arterial oxygenation and of postmortem pressure-volume measurements were found after treatment with Survanta + PEG compared with Survanta alone. PEG added to Survanta increased resistance to inactivation caused by tracheal fluid taken from animals injured with HCl. Other work suggests that PEG promotes surfactant aggregation, separates surfactant from surfactant inhibitors, and enhances access of surfactant to the gas-liquid interface. The addition of polymers to surfactants may also be useful in the treatment of lung injury where inactivation of surfactant has already occurred.
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Affiliation(s)
- K W Lu
- Department of Pediatrics, University of California-San Francisco, San Francisco, California, USA.
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Sayeed MM. Does burn injury affect pulmonary surfactant metabolism? Crit Care Med 2001; 29:1484-5. [PMID: 11445719 DOI: 10.1097/00003246-200107000-00036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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