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Abstract
Pulmonary surfactant is a critical component of lung function in healthy individuals. It functions in part by lowering surface tension in the alveoli, thereby allowing for breathing with minimal effort. The prevailing thinking is that low surface tension is attained by a compression-driven squeeze-out of unsaturated phospholipids during exhalation, forming a film enriched in saturated phospholipids that achieves surface tensions close to zero. A thorough review of past and recent literature suggests that the compression-driven squeeze-out mechanism may be erroneous. Here, we posit that a surfactant film enriched in saturated lipids is formed shortly after birth by an adsorption-driven sorting process and that its composition does not change during normal breathing. We provide biophysical evidence for the rapid formation of an enriched film at high surfactant concentrations, facilitated by adsorption structures containing hydrophobic surfactant proteins. We examine biophysical evidence for and against the compression-driven squeeze-out mechanism and propose a new model for surfactant function. The proposed model is tested against existing physiological and pathophysiological evidence in neonatal and adult lungs, leading to ideas for biophysical research, that should be addressed to establish the physiological relevance of this new perspective on the function of the mighty thin film that surfactant provides.
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Affiliation(s)
- Fred Possmayer
- Department of Biochemistry, Western University, London, Ontario N6A 3K7, Canada
- Department of Obstetrics/Gynaecology, Western University, London, Ontario N6A 3K7, Canada
| | - Yi Y Zuo
- Department of Mechanical Engineering, University of Hawaii at Manon, Honolulu, Hawaii 96822, United States
- Department of Pediatrics, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96826, United States
| | - Ruud A W Veldhuizen
- Department of Physiology & Pharmacology, Western University, London, Ontario N6A 5C1, Canada
- Department of Medicine, Western University, London, Ontario N6A 3K7, Canada
- Lawson Health Research Institute, London, Ontario N6A 4V2, Canada
| | - Nils O Petersen
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
- Department of Chemistry, Western University, London, Ontario N6A 5B7, Canada
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2
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Jayadi, Airlangga PS, Kusuma E, Waloejo CS, Salinding A, Lestari P. Correlation between serum surfactant protein-D level with respiratory compliance and acute respiratory distress syndrome in critically ill COVID-19 Patients: A retrospective observational study. Int J Crit Illn Inj Sci 2022; 12:204-210. [PMID: 36779213 PMCID: PMC9910112 DOI: 10.4103/ijciis.ijciis_27_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 07/03/2022] [Accepted: 07/20/2022] [Indexed: 12/24/2022] Open
Abstract
Background Acute respiratory distress syndrome (ARDS) is one of the manifestations of severe coronavirus disease 2019 (COVID-19) with low respiratory compliance and poor oxygenation as main characteristics and mortality rate of 50%-94%. Surfactants, including surfactant protein D (SP-D), have a role in maintaining respiratory compliance. This study aimed to analyze the relationship between serum SP-D levels with respiratory compliance and ARDS in patients with critically ill COVID-19 pneumonia. Methods This study was a cross-sectional study. Subjects were adult reverse transcription-polymerase chain reaction-confirmed COVID-19 patients who had ARDS treated with invasive mechanical ventilation. All data were obtained from medical records. Statistical analysis was done using Spearman test, Mann-Whitney test, and receiver operating characteristic curve. Results Serum level of SP-D was significantly correlated with static respiratory compliance (P = 0.009; correlation coefficient [rs] = 0.467). Serum SP-D levels correlated with ARDS severity (P < 0.001). SP-D levels had a very strong diagnostic value for ARDS severity, with an optimal cutoff value of 44.24 ng/mL (sensitivity 92.3%; specificity 94.1%). ARDS severity also correlated significantly with respiratory compliance (P = 0.005; correlation coefficient 0.496). Conclusion Higher serum SP-D levels were associated with lower respiratory compliance, ARDS severity, and may be utilized diagnostically to identify patients with severe ARDS.
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Affiliation(s)
- Jayadi
- Department of Anesthesiology and Reanimation, Faculty of Medicine, Dr. Soetomo General Hospital, Airlangga University, Surabaya, Indonesia
| | - Prananda Surya Airlangga
- Department of Anesthesiology and Reanimation, Faculty of Medicine, Dr. Soetomo General Hospital, Airlangga University, Surabaya, Indonesia
| | - Edward Kusuma
- Department of Anesthesiology and Reanimation, Faculty of Medicine, Dr. Soetomo General Hospital, Airlangga University, Surabaya, Indonesia
| | - Christrijogo Soemartono Waloejo
- Department of Anesthesiology and Reanimation, Faculty of Medicine, Dr. Soetomo General Hospital, Airlangga University, Surabaya, Indonesia
| | - Agustina Salinding
- Department of Anesthesiology and Reanimation, Faculty of Medicine, Dr. Soetomo General Hospital, Airlangga University, Surabaya, Indonesia
| | - Pudji Lestari
- Department of Public Health and Preventive Medicine, Faculty of Medicine, Airlangga University, Surabaya, Indonesia
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3
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Mariano CA, Sattari S, Quiros KAM, Nelson TM, Eskandari M. Examining lung mechanical strains as influenced by breathing volumes and rates using experimental digital image correlation. Respir Res 2022; 23:92. [PMID: 35410291 PMCID: PMC8999998 DOI: 10.1186/s12931-022-01999-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 03/18/2022] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Mechanical ventilation is often employed to facilitate breathing in patients suffering from respiratory illnesses and disabilities. Despite the benefits, there are risks associated with ventilator-induced lung injuries and death, driving investigations for alternative ventilation techniques to improve mechanical ventilation, such as multi-oscillatory and high-frequency ventilation; however, few studies have evaluated fundamental lung mechanical local deformations under variable loading. METHODS Porcine whole lung samples were analyzed using a novel application of digital image correlation interfaced with an electromechanical ventilation system to associate the local behavior to the global volume and pressure loading in response to various inflation volumes and breathing rates. Strains, anisotropy, tissue compliance, and the evolutionary response of the inflating lung were analyzed. RESULTS Experiments demonstrated a direct and near one-to-one linear relationship between applied lung volumes and resulting local mean strain, and a nonlinear relationship between lung pressures and strains. As the applied air delivery volume was doubled, the tissue surface mean strains approximately increased from 20 to 40%, and average maximum strains measured 70-110%. The tissue strain anisotropic ratio ranged from 0.81 to 0.86 and decreased with greater inflation volumes. Local tissue compliance during the inflation cycle, associating evolutionary strains in response to inflation pressures, was also quantified. CONCLUSION Ventilation frequencies were not found to influence the local stretch response. Strain measures significantly increased and the anisotropic ratio decreased between the smallest and greatest tidal volumes. Tissue compliance did not exhibit a unifying trend. The insights provided by the real-time continuous measures, and the kinetics to kinematics pulmonary linkage established by this study offers valuable characterizations for computational models and establishes a framework for future studies to compare healthy and diseased lung mechanics to further consider alternatives for effective ventilation strategies.
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Affiliation(s)
- C A Mariano
- Department of Mechanical Engineering, University of California at Riverside, Riverside, CA, USA
| | - S Sattari
- Department of Mechanical Engineering, University of California at Riverside, Riverside, CA, USA
| | - K A M Quiros
- Department of Mechanical Engineering, University of California at Riverside, Riverside, CA, USA
| | - T M Nelson
- Department of Mechanical Engineering, University of California at Riverside, Riverside, CA, USA
| | - M Eskandari
- Department of Mechanical Engineering, University of California at Riverside, Riverside, CA, USA.
- BREATHE Center, School of Medicine, University of California at Riverside, Riverside, CA, USA.
- Department of Bioengineering, University of California at Riverside, Riverside, CA, USA.
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Szoták-Ajtay K, Szõke D, Kovács G, Andréka J, Brenner GB, Giricz Z, Penninger J, Kahn ML, Jakus Z. Reduced Prenatal Pulmonary Lymphatic Function Is Observed in Clp1 K/K Embryos With Impaired Motor Functions Including Fetal Breathing Movements in Preparation of the Developing Lung for Inflation at Birth. Front Bioeng Biotechnol 2020; 8:136. [PMID: 32211389 PMCID: PMC7067749 DOI: 10.3389/fbioe.2020.00136] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 02/11/2020] [Indexed: 11/13/2022] Open
Abstract
Embryonic lungs must be inflated immediately after birth to establish respiration. In addition to pulmonary surfactant, recently, we have revealed lymphatic function as a previously unknown regulator of prenatal lung compliance that prepares the embryonic lung for inflation at birth. It is well-documented that the late gestation embryo performs episodic breathing-like movements called as fetal breathing movements (FBMs), but the physiological importance of these events is not clear. Here we aimed to study the physiological role of FBMs in preparation for air inflation at birth. Clp1K/K late gestation embryos develop a progressive loss of spinal motor neurons associated with axonal degeneration and denervation of neuromuscular junctions serving as an ideal genetic model to test the possible role of FBMs. We demonstrated that Clp1K/K newborns show impaired motor function resulting in fatal respiratory failure after birth. Next, we showed that the alveolar septa are thicker, and the alveolar area is reduced in Clp1K/K late gestation embryos, while the expression of molecular markers of lung development are not affected. Importantly, pulmonary lymphatic vessels are dilated and the prenatal pulmonary lymphatic function is reduced in Clp1K/K late gestation embryos. Our results have revealed that Clp1K/K mice show impaired motor functions including FBMs, and late gestation Clp1K/K embryos display reduced prenatal lymphatic function and impaired lung expansion represented as thickened alveolar septa and reduced alveolar area in preparation of the developing lung for inflation at birth. These findings suggest a possible mechanism that FBMs, similarly to breathing movements after birth, stimulate prenatal lymphatic function in pulmonary collecting lymphatics lacking smooth muscle coverage to prepare the developing lung for inflation and gas exchange at birth. Moreover, these results raise the possibility that stimulating FBMs during late gestation might be an effective way to reduce the risk of the development of neonatal respiratory failure.
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Affiliation(s)
- Kitti Szoták-Ajtay
- Department of Physiology, Semmelweis University School of Medicine, Budapest, Hungary.,MTA-SE "Lendület" Lymphatic Physiology Research Group of the Hungarian Academy of Sciences and the Semmelweis University, Budapest, Hungary
| | - Dániel Szõke
- Department of Physiology, Semmelweis University School of Medicine, Budapest, Hungary.,MTA-SE "Lendület" Lymphatic Physiology Research Group of the Hungarian Academy of Sciences and the Semmelweis University, Budapest, Hungary
| | - Gábor Kovács
- Department of Physiology, Semmelweis University School of Medicine, Budapest, Hungary.,MTA-SE "Lendület" Lymphatic Physiology Research Group of the Hungarian Academy of Sciences and the Semmelweis University, Budapest, Hungary
| | - Judit Andréka
- Department of Physiology, Semmelweis University School of Medicine, Budapest, Hungary.,MTA-SE "Lendület" Lymphatic Physiology Research Group of the Hungarian Academy of Sciences and the Semmelweis University, Budapest, Hungary
| | - Gábor B Brenner
- Department of Pharmacology and Pharmacotherapy, Semmelweis University School of Medicine, Budapest, Hungary
| | - Zoltán Giricz
- Department of Pharmacology and Pharmacotherapy, Semmelweis University School of Medicine, Budapest, Hungary
| | - Josef Penninger
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria.,Department of Medical Genetics, Life Science Institute, University of British Columbia, Vancouver, BC, Canada
| | - Mark L Kahn
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Zoltán Jakus
- Department of Physiology, Semmelweis University School of Medicine, Budapest, Hungary.,MTA-SE "Lendület" Lymphatic Physiology Research Group of the Hungarian Academy of Sciences and the Semmelweis University, Budapest, Hungary
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Norman TA, Gower AC, Chen F, Fine A. Transcriptional landscape of pulmonary lymphatic endothelial cells during fetal gestation. PLoS One 2019; 14:e0216795. [PMID: 31083674 PMCID: PMC6513083 DOI: 10.1371/journal.pone.0216795] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 04/29/2019] [Indexed: 02/06/2023] Open
Abstract
The genetic programs responsible for pulmonary lymphatic maturation prior to birth are not known. To address this gap in knowledge, we developed a novel cell sorting strategy to collect fetal pulmonary lymphatic endothelial cells (PLECs) for global transcriptional profiling. We identified PLECs based on their unique cell surface immunophenotype (CD31+/Vegfr3+/Lyve1+/Pdpn+) and isolated them from murine lungs during late gestation (E16.5, E17.5, E18.5). Gene expression profiling was performed using whole-genome microarrays, and 1,281 genes were significantly differentially expressed with respect to time (FDR q < 0.05) and grouped into six clusters. Two clusters containing a total of 493 genes strongly upregulated at E18.5 were significantly enriched in genes with functional annotations corresponding to innate immune response, positive regulation of angiogenesis, complement & coagulation cascade, ECM/cell-adhesion, and lipid metabolism. Gene Set Enrichment Analysis identified several pathways coordinately upregulated during late gestation, the strongest of which was the type-I IFN-α/β signaling pathway. Upregulation of canonical interferon target genes was confirmed by qRT-PCR and in situ hybridization in E18.5 PLECs. We also identified transcriptional events consistent with a prenatal PLEC maturation program. This PLEC-specific program included individual genes (Ch25h, Itpkc, Pcdhac2 and S1pr3) as well as a set of chemokines and genes containing an NF-κB binding site in their promoter. Overall, this work reveals transcriptional insights into the genes, signaling pathways and biological processes associated with pulmonary lymphatic maturation in the fetal lung.
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Affiliation(s)
- Timothy A Norman
- Pulmonary Center, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Pathology & Laboratory Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Adam C Gower
- Clinical and Translational Science Institute, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Felicia Chen
- Pulmonary Center, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Alan Fine
- Pulmonary Center, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Boston Veteran's Hospital, West Roxbury, Massachusetts, United States of America
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Satalin J, Habashi NM, Nieman GF. Never give the lung the opportunity to collapse. TRENDS IN ANAESTHESIA AND CRITICAL CARE 2018. [DOI: 10.1016/j.tacc.2018.05.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Jakus Z, Gleghorn JP, Enis DR, Sen A, Chia S, Liu X, Rawnsley DR, Yang Y, Hess PR, Zou Z, Yang J, Guttentag SH, Nelson CM, Kahn ML. Lymphatic function is required prenatally for lung inflation at birth. ACTA ACUST UNITED AC 2014; 211:815-26. [PMID: 24733830 PMCID: PMC4010903 DOI: 10.1084/jem.20132308] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Neonatal mice lacking lymphatic vessels due to loss of lymphangiogenic factor CCBE1 or VEGFR3 function fail to inflate their lungs, suggestive of respiratory failure in infants with congenital pulmonary lymphangiectasia. Mammals must inflate their lungs and breathe within minutes of birth to survive. A key regulator of neonatal lung inflation is pulmonary surfactant, a lipoprotein complex which increases lung compliance by reducing alveolar surface tension (Morgan, 1971). Whether other developmental processes also alter lung mechanics in preparation for birth is unknown. We identify prenatal lymphatic function as an unexpected requirement for neonatal lung inflation and respiration. Mice lacking lymphatic vessels, due either to loss of the lymphangiogenic factor CCBE1 or VEGFR3 function, appear cyanotic and die shortly after birth due to failure of lung inflation. Failure of lung inflation is not due to reduced surfactant levels or altered development of the lung but is associated with an elevated wet/dry ratio consistent with edema. Embryonic studies reveal active lymphatic function in the late gestation lung, and significantly reduced total lung compliance in late gestation embryos that lack lymphatics. These findings reveal that lymphatic vascular function plays a previously unrecognized mechanical role in the developing lung that prepares it for inflation at birth. They explain respiratory failure in infants with congenital pulmonary lymphangiectasia, and suggest that inadequate late gestation lymphatic function may also contribute to respiratory failure in premature infants.
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Affiliation(s)
- Zoltán Jakus
- Department of Medicine, 2 Cardiovascular Institute, and 3 Department of Dermatology, University of Pennsylvania, Philadelphia, PA 19104
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Jonson B, Richard JC, Straus C, Mancebo J, Lemaire F, Brochard L. Pressure-volume curves and compliance in acute lung injury: evidence of recruitment above the lower inflection point. Am J Respir Crit Care Med 1999; 159:1172-8. [PMID: 10194162 DOI: 10.1164/ajrccm.159.4.9801088] [Citation(s) in RCA: 210] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Measuring elastic pressure-volume (Pel-V) curves of the respiratory system and the volume recruited by a positive end-expiratory pressure (PEEP) allows one to study the pressure range over which recruitment occurs in acute lung injury (ALI), and to explain how recruitment affects the compliance. Pel-V curves were measured with the low flow inflation technique in 11 patients mechanically ventilated for ALI. Curve I was recorded during inflation from the volume attained after a prolonged expiration (6 s) at PEEP (9.0 +/- 2.2 cm H2O), and Curve II after expiration to the elastic equilibrium volume at zero end-expiratory pressure (ZEEP). By using the end-expiratory volume of the breaths, the curves were aligned on a common volume axis to determine the effect of a single complete expiration. In each patient, Curve II (from ZEEP) was shifted toward lower volumes than Curve I. The volume shift, probably due to derecruitment, was 205 +/- 100 ml at 15 cm H2O (p < 0.01) and 78 +/- 93 ml at 30 cm H2O (p < 0.01); thus, during inflation from ZEEP, the volume deficit was successively regained over a pressure range up to at least 30 cm H2O. At any pressure, compliance was higher on the curve from ZEEP than from PEEP, by 10.0 +/- 8.7 ml/cm H2O at 15 cm H2O (p < 0.01), and by 5.4 +/- 5.5 at 30 cm H2O (p < 0.01). It is concluded that in ALI, a single expiration to ZEEP leads to lung collapse. High compliance during insufflation from ZEEP indicates that lung recruitment happens far above the lower inflection point of the Pel-V curve.
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Affiliation(s)
- B Jonson
- Medical Intensive Care Unit, INSERM U492, Hôpital Henri Mondor, AP-HP Paris XII University, Créteil, France
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Morita M, Tabata N. Studies on asphyxia: on the changes of the alveolar walls of rats in the hypoxic state. II. The hypoxic state produced by carbon dioxide and methane gases. Forensic Sci Int 1988; 39:257-62. [PMID: 3147928 DOI: 10.1016/0379-0738(88)90128-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Experimental studies were presented here concerning death by asphyxia due to the inhalation of carbon dioxide and methane gases. The morphological changes were almost the same as those demonstrated in our previous report. The authors concluded that the morphological changes in the lung tissue were not attributable to the chemical specificity of gases used in the experiment but to the decrease of oxygen.
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Affiliation(s)
- M Morita
- Department of Legal Medicine, Sapporo Medical College, Japan
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10
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Guice KS, Oldham KT, Wolfe RR, Simon RH. Lung injury in acute pancreatitis: primary inhibition of pulmonary phospholipid synthesis. Am J Surg 1987; 153:54-61. [PMID: 3799893 DOI: 10.1016/0002-9610(87)90201-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Alterations in the pulmonary surfactant system are partly responsible for the respiratory insufficiency seen with acute pancreatitis. In this model of cerulein-induced pancreatitis in rats, we utilized a new stable isotope metabolic tracer technique to examine one aspect of the pulmonary surfactant system and its relationship to associated lung injury. We have demonstrated primary, early depression of lung phospholipid synthesis reflected in both lung tissue and alveolar washings. We suggest that this quantitative change in pulmonary surfactant synthetic rate may partly explain the occurrence of respiratory failure with acute pancreatitis.
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Aberg A, Gislen L. Use of the drop volume of amniotic fluid in estimating the risk for respiratory distress syndrome in the newborn infant. Am J Obstet Gynecol 1986; 154:68-74. [PMID: 3753823 DOI: 10.1016/0002-9378(86)90395-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The present study describes the testing and function of the drop-volume method in the analysis of fetal lung maturity with use of amniotic fluid. Elevated surface tension resulting from a lack of surface-active phospholipids (surfactant) is the primary etiologic defect in the development of respiratory distress syndrome. The drop-volume method quantifies the surface tension of amniotic fluid with use of the fact that the volume of a falling drop of liquid is proportional to the quantity of surfactant in the solution. The drop-volume method requires only 2 minutes and 2 ml of amniotic fluid and predicts fetal lung maturity with an accuracy equal to or greater than that of other tests currently in use.
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Casals C, Herrero LM, Soriano Y, García-Barreno P, Municio AM. Membrane regulation of liver and lung microsomes under low oxygen tension. Biochem Biophys Res Commun 1985; 126:551-8. [PMID: 3970707 DOI: 10.1016/0006-291x(85)90641-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A highly monitorized animal model has been developed for the study of the influence of low oxygen tension on lipid composition, microviscosity and regulation of enzyme activities involved in the phospholipid synthesis of hepatic and pulmonary microsomes. Microviscosity decreased in liver microsomes whereas no difference was shown in that of microsomal membrane core of hypoxemic lung. Nevertheless, phospholipid and cholesterol content of both liver and lung membranes changed significantly. Microsomal membranes of hypoxemic liver increased the unsaturation degree of fatty acids, whereas hypoxemic lung membranes become more saturated, mainly due to the increase of palmitic acid. The adaptive response of lung was confirmed by the high increase of the deacylation-reacylation mechanism.
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Snyder JV, Carroll GC, Schuster DP, Culpepper J, Klain M. Mechanical ventilation: physiology and application. Curr Probl Surg 1984; 21:1-87. [PMID: 6368135 DOI: 10.1016/0011-3840(84)90002-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Lafranconi WM, Spall RD, Sipes IG, Duhamel RC, Meezan E, Brendel K. Rapid isolation of type II pneumocytes with magnetic removal of macrophages. Exp Lung Res 1983; 4:191-204. [PMID: 6851958 DOI: 10.3109/01902148309046060] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A method is described for the rapid preparation of lung cell fractions enriched in type II alveolar pneumocytes. Isolated perfused rabbit lungs are exposed to Fe3O4 by tracheal lavage, which permits pulmonary alveolar macrophages to phagocytize the particles. Alveolar epithelial cells are then selectively freed from the basement membrane matrix by critical placement of collagenase and elastase. Detached cells are harvested either by repeated tracheal lavage or by mincing the lobes and filtering freed cells through a series of nylon mesh sieves. Iron oxide-containing macrophages are then removed from the harvested cells by a strong magnetic field. A final sizing of the macrophage-depleted suspension yields a preparation enriched in alveolar type II cells. Eight million viable cells (95% type II) were obtained per rabbit lung when harvested by lavage, while 32 x 10(6) (88% type II) cells were obtained from minced lungs. These values for cell yield and relative purity are comparable to previously described separation methods that depend upon differences in cell density or size. A major advantage of the magnetic separation procedure is the substantially shortened preparation time, typically 2 hr instead of 4. The viability (90-95%), oxygen consumption (88 nmol/10(6) cells/hr), and incorporation of [14C]acetate and [14C]choline (0.44 and 0.115 nmol/10(6) cells/hr, respectively) indicate that these cells will be suitable for pharmacologic and toxicologic investigation.
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Diedrich K, Beutler HO, Krebs D. A new method of evaluating fetal lung maturity: the enzymatic lecithin determination in amniotic fluid. Eur J Obstet Gynecol Reprod Biol 1982; 13:279-89. [PMID: 7117659 DOI: 10.1016/0028-2243(82)90050-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The concentration of phospholipids is well suited as indicator for the prognosis of a possibly postnatal respiratory distress syndrome. The method used most frequently up to now has been the determination of the lecithin/sphingomyelin ratio (L/S ratio) by thin layer chromatography. We have developed a specific assay for the quantitative determination of lecithin in amniotic fluid, which yields absolute concentration values and does not require the determination of a concentration ratio. Lecithin is hydrolized by phospholipase C and alkaline phosphatase. Choline is determined afterwards by a highly specific choline kinase from yeast. The total time required is less than 2 h. The usual lecithin concentration present in the 35th to 38th wk of gestation can be determined with a coefficient of variation of 2-3% (n=30). Fetal lung maturity can be expected at a lecithin concentration above 4.7-5.1 mg/100 ml. The method compares well with the L/S ratio. Detailed data about clinical significance will be presented. Good precision accuracy and simple handling make enzymatic lecithin determinations suitable for routine use.
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Abstract
With increasing age, chronic underlying disease, and debility, the oropharyngeal flora are colonized with aerobic gram-negative bacilli. In this debilitated population, gram-negative bacillary pneumonias (GNBP) are increasingly common. GNBP account for two of every three pneumonia deaths today. As a group, the mortality of GNBP is about 50%. Although the original epidemiologic surveys were done 15 years ago, there is little evidence for an improving case fatality rate despite the appearance of aminoglycoside antibiotics, carbenicillin, and cephalosporins. In susceptible patients, GNBP pneumonias occur both in the community and as nosocomial infections. Recognition of the dangers of contaminated reservoir nebulizers or other similar devices used in inhalation therapy has led to epidemiologic measures within hospitals that have markedly decreased the incidence of this nosocomial GNBP. The role of Gram stain and culture of expectorated sputum and similar examinations of specimens obtained by transtracheal aspiration, fiberoptic bronchoscopy, and lung biopsy in the diagnosis of GNBP are discussed in this review (see Criteria for Diagnosis). In the presence of pulmonary emphysema, congestive heart failure, mixed gram-negative bacillary infections, or the use of immunosuppressive drugs, typical characteristics of individual GNBP may not be apparent. Typical features of Pseudomonas aeruginosa, Escherichia coli, Enterobacter, Proteus, Hemophilus, and anaerobic pulmonary infections are described. Early recognition and institution of appropriate antibacterial agents are emphasized, particularly in GNBP caused by Pseudomonas aeruginosa, Escherichia coli, or Friedländer's bacillus, where the mortality approaches 70%. The mortality of GNBP, including Enterobacter, Proteus, Hemophilus, and anaerobic GNBP, is about 20%. The latter figure is the same as the mortality of pneumococcal pneumonia in similar patients.
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Abstract
This paper details efforts to define the primary pathophysiology of acute smoke inhalation without the variables of infection, burns, or fluid resuscitation. A standard dose of smoke (wood and kerosene) was delivered at 37 C to mongrel dogs. The parameters studied included blood gases, carboxyhemoglobin, pulmonary and systemic hemodynamics, respiratory mechanics, surface tension area curves as an indication of surfactant activity, and in vivo photomicroscopy. The FiO2 of the smoke was 17 volumes per cent; the carbon monoxide 17,000 ppm. Immediately following smoke exposure, dense, nonsegmental atelectasis developed. Hemodynamic changes were insignificant, but the PaO2 fell to 49 mmHg; the right to left shunt rose from 5 to 41%. Surfactant reduction was significant: enough to cause an increase in the minimum surface tension from 7 to 22 dynes/cm. This surfactant loss may explain the atelectasis seen and the marked instability of subpleural alveolar walls. The data collected are consistent and support the acute inactivation of surfactant as one of the primary pathophysiologic events in smoke inhalation. The clinical correlation is good; surfactant loss may explain why victims of smoke inhalation are so vulnerable to fluid administration if they have thermal burns as well effectiveness of medical devices.
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Svendsen O, Aaes-Jørgensen T. Studies on the fate of vegetable oit after intramuscular injection into experimental animals. ACTA PHARMACOLOGICA ET TOXICOLOGICA 1979; 45:352-78. [PMID: 539434 DOI: 10.1111/j.1600-0773.1979.tb02404.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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23
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Le Mesurier SM, Stewart BW, O'Connell PJ, Lykke AW. Pulmonary responses to atmospheric pollutants. II. Effect of petrol vapour inhalation on secretion of pulmonary surfactant. Pathology 1979; 11:81-7. [PMID: 581905 DOI: 10.3109/00313027909063542] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Inhalation of air contaminated with petrol vapour has been shown to produce reduced surfactant levels in the lungs of rats. Pulmonary surfactant was obtained by endobronchial lavage followed by salt extraction and freeze drying to obtain the dry, hydrophobic product. During 45 days of continuous exposure, the lowest yield of surfactant was obtained after 15 days of treatment. During the following 30 days of treatment, the surfactant yield reached a relatively constant level, approximately half the mean value for control animals. Chromatographic analysis indicated no qualitative alteration in the phospholipid components of surfactant with increasing times of exposure to the irritant. It has been possible to correlate biochemical evidence of toxic lung injury with signs of cellular damage obtained from ultrastructural studies.
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Stoner GD, Hallman M, Troxell MC. Lecithin biosynthesis in a clonal line of lung adenoma cells with type II alveolar cell properties. Exp Mol Pathol 1978; 29:102-14. [PMID: 581072 DOI: 10.1016/0014-4800(78)90030-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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25
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Abstract
The survival of Staphylococcus aureus in the lungs of mice was studied under various conditions. Doses of 10(7) to 10(9) washed staphylococci were quantitatively introduced into the lungs after intratracheal inoculation in mice under either ether or sodium pentobarbital anesthesia. Mice were sacrificed at intervals, the lungs were excised and homogenized, and the cocci were enumerated by plate count. The 50% lethal dose was 6 x 10(8) cocci per mouse, and mice died within 24 h but without proliferation of the inoculum. Mice given 10(8) cocci intratracheally under pentobarbital anesthesia regularly survived and eliminated the organisms over a 48-h period. The use of ether anesthesia resulted in persistence of the inoculum for up to 48 h, but the organisms were then eliminated. Inability to proliferate did not appear to result from a lack of iron because pretreatment of the mice with ferric ammonium citrate or Imferon did not alter inoculum survival. Staphylococci inoculated intratracheally in mice infected with influenza virus 3 to 21 days previously showed no enhanced persistence or multiplication. Cocci preclumped with fibrinogen, inocula mixed with 10 times the number of Formalin-killed staphylococci, or inocula of the encapsulated Smith strain did not survive any better than conventional inocula, suggesting that phagocytosis might not be the sole mechanism for elimination. However, a sedimentable fraction from normal or infected lung homogenates proved either inhibitory or cidal for staphylococci in vitro.
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26
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Suter PM, Fairley HB, Isenberg MD. Effect of tidal volume and positive end-expiratory pressure on compliance during mechanical ventilation. Chest 1978; 73:158-62. [PMID: 340159 DOI: 10.1378/chest.73.2.158] [Citation(s) in RCA: 143] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In 12 patients requiring therapy with mechanical ventilation for acute respiratory failure, total static compliance (Cst) increased from 29 +/- 4 ml/cm H2O at a tidal volume (TV) of 5 ml/kg to 42 +/- 7 ml/cm H2O at a TV of 15 ml/kg. Similarly, Cst increased from 42 +/- 7 ml/cm H2O to 52 +/- 8 ml/cm H2O between 0 and 6 cm H2O of positive end-expiratory pressure (PEEP). At high levels of pulmonary inflation (ie, high PEEP and large TV) compliance decreased. The changes of total respiratory compliance with TV were mainly due to changes in pulmonary compliance. With PEEP, the functional residual capacity increased, and specific compliance did not change. Two mechanisms may be responsible for the changes in compliance. First, varying TV or PEEP will alter the position of tidal ventilation on the pressure-volume curve, resulting in an increase in compliance with increasing TV and PEEP up to a point, where overdistention occurs and compliance decreases. Secondly, the function of the surface-lowering substance may be altered in acute pulmonary parenchymal disease, thus disturbing the regulation of surface tension over the range of pulmonary inflation studied.
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Estudio de las alteraciones de las propiedades tensioactivas del surfactante pulmonar del perro por la produccion de un enfisema experimental papainico. Arch Bronconeumol 1977. [DOI: 10.1016/s0300-2896(15)32681-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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29
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Williams MC. Conversion of lamellar body membranes into tubular myelin in alveoli of fetal rat lungs. J Cell Biol 1977; 72:260-77. [PMID: 833198 PMCID: PMC2111004 DOI: 10.1083/jcb.72.2.260] [Citation(s) in RCA: 236] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Fluid-filled lumina of fetal rat lungs contain lamellar bodies (LBs) as well as tubular myelin (TM), both of which are thought to be stores of phospholipid-rich pulmonary surfactant. The alveolar epithelium is believed to secrete LBs, but neither the origin nor the mechanism of TM formation is entirely certain. The main objective of this study was to determine the relationship between secreted LBs and TM and to define membrane phenomena which occur during TM formation. I examined lung tissues of 20-21 day-old fetuses (day 22 = term) using transmission and high voltage transmission electron microscopy and cytochemistry. My findings indicate that secreted LBs, identified by the presence of an acid-phosphatase reactive core, are the precursor of TM. Secreted LBs are highly organized structures which contain structurally specialized areas, one of which is a "mini-lattice" structure similar to TM. During TM formation, fuzzes or 8.0-nm diameter particles appear on transition membranes, although LB membranes appear to lack both structures. Similar particles are present on TM membranes and are generally associated with membrane intersections. My results provide evidence that TM is formed from LBs within the alveolar lumen by mechanisms which may be complex.
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Lieber M, Smith B, Szakal A, Nelson-Rees W, Todaro G. A continuous tumor-cell line from a human lung carcinoma with properties of type II alveolar epithelial cells. Int J Cancer 1976; 17:62-70. [PMID: 175022 DOI: 10.1002/ijc.2910170110] [Citation(s) in RCA: 913] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The A549 tumor-cell line, initiated from a human alveolar cell carcinoma, has been continuously propagated in vitro for more than 3 years (more than 1,000 cell generations). These cells have a human karyotype and appear to have been derived from a single parent cell. All A549 cells examined by electron microscopy at both early and late passage levels contain multilamellar cytoplasmic inclusion bodies typical of those found in type II alveolar epithelial cells of the lung. At early and late passage levels, the cells synthesize lecithin with a high percentage of disaturated fatty acids utilizing the cytidine diphosphocholine pathway; such a pattern of phospholipid synthesis is expected for cells believed to be responsible for pulmonary surfactant synthesis. The A549 cell line should permit in vitro analysis of human surfactant synthesis and secretion and possibly provide a source of human surfactant for therapeutic intervention in pulmonary disease states characterized by surfactant deficiency.
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32
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Allgemeine und spezielle Maßnahmen zur Verhütung und Beseitigung der postoperativen Atelektase. ACTA ACUST UNITED AC 1976. [DOI: 10.1007/978-3-642-66553-0_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
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33
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34
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Rooney SA, Gross I, Gassenheimer LN, Motoyama EK. Stimualtion of glycerolphosphate phosphatidyltransferase activity in fetal rabbit lung by cortisol administration. BIOCHIMICA ET BIOPHYSICA ACTA 1975; 398:433-41. [PMID: 1242106 DOI: 10.1016/0005-2760(75)90194-0] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Phosphatidylglycerol is an important component of pulmonary surfactant. Previous studies have shown that direct administration of corticosteroids of thyroxine to the fetus during the latter part of gestation results in accelerated lung maturation with increased surfactant production. We have shown that administration of cortisol to fetal rabbits at 24 days' gestation results 3 days later in a significant increase in the activity of pulmonary glycerolphosphate phosphatidyltransferase, an enzyme involved in the synthesis of phosphatidylglycerol. The activity of the liver enzyme was not affected. Choline phosphotransferase, CDPdiglyceride-inositol phosphatidyltransferase, lysophosphatidic acid acyltransferase and lysolecithin acyltransferase activities were not altered significantly by cortisol treatment. Thyroxine treatment had no effect on any of the enzymes of phospholipid or fatty acid biosynthesis studied.
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35
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36
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Loosli CG, Stinson SF, Ryan DP, Hertweck MS, Hardy JD, Serebrin R. The destruction of type 2 pneumocytes by airborne influenza PR8-A virus; its effect on surfactant and lecithin content of the pneumonic lesions of mice. Chest 1975; 67:7S-14S. [PMID: 1172777 DOI: 10.1378/chest.67.2_supplement.7s] [Citation(s) in RCA: 42] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Influenzal pneumonia has been studied in mice subjected to sublethal doses of airborne PR8-A influenza virus. Electron microscopy revealed that the virus propagated in and at the same time destroyed the ciliated and nonciliated bronchial cells and the types 1 and 2 alveolar pneumocytes. The regenerating bronchial membranes were metaplastic and grew peripherally into the surrounding alveolar ducts and alveoli to form epithelial nodules which caused obstruction and collapse of the involved lobes. The development of the lung lesions was correlated with phospholipid (lecithin) levels in consolidated and unconsolidated infected and normal lungs. As the lungs became more and more consolidated, there was a corresponding and significant decrease in the amount of phospholipid (dipalmitoyl lecithin) compared to the amount of normal or unconsolidated infected tissue. The destruction of the type 2 pneumocytes by the influenza virus and their failure to regenerate is considered to be the reason for the low phospholipid levels in the involved lobes, and thus an important cause of post-influenzal collapse in mice. The above adds additional evidence to the view that the type 2 pneumocytes are a major source of surfactant in mammalian lungs.
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37
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Alcorn DG, Alexander IG, Maloney JE, Ritchie BC, Walker AM. Morphological development of the lung: a review. AUSTRALIAN PAEDIATRIC JOURNAL 1974; 10:189-98. [PMID: 4374920 DOI: 10.1111/j.1440-1754.1974.tb02919.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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40
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Rooney SA, Canavan PM, Motoyama EK. The identification of phosphatidylglycerol in the rat, rabbit, monkey and human lung. BIOCHIMICA ET BIOPHYSICA ACTA 1974; 360:56-67. [PMID: 4369311 DOI: 10.1016/0005-2760(74)90179-9] [Citation(s) in RCA: 128] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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41
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Solliday NH, Chandrasekhar AJ, Nam KI, Cugell DW, Bazley ES. The Lazy Respiratory Center–or How to Recognize a Tired Horse. Chest 1974. [DOI: 10.1378/chest.66.1.71] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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42
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Schulz H. [Electron microscope findings in hyperoxia (author's transl)]. PNEUMONOLOGIE. PNEUMONOLOGY 1973; 149:181-92. [PMID: 4205212 DOI: 10.1007/bf02096016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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43
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44
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Pender CB. Respiratory distress in the newborn due to aspiration of amniotic fluid and its contents. Resuscitation 1973; 2:157-67. [PMID: 4801161 DOI: 10.1016/0300-9572(73)90041-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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45
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46
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Munden JW, Swarbrick J. Time-dependent surface behavior of dipalmitoyllecithin and lung alveolar surfactant monolayers. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 291:344-50. [PMID: 4739527 DOI: 10.1016/0005-2736(73)90487-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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47
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Gerbie MV, Gerbie AB, Boehm J. Diagnosis of fetal maturity by amniotic fluid phospholipids. Am J Obstet Gynecol 1972; 114:1078-82. [PMID: 4678300 DOI: 10.1016/0002-9378(72)90872-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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48
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49
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