American Journal of Respiratory and Critical Care Medicine Vol 165. pp. 1546-1550, (2002)
© 2002 American Thoracic Society
Surfactant Proteins A and D in Children with Pulmonary Disease due to Gastroesophageal Reflux
Matthias Griese,
Niels Maderlechner,
Peter Ahrens and
Richard Kitz
Dr. von Hauner Childrens' Hospital, Ludwig-Maximilians-University, Munich; and Department of Pediatrics, Johann Wolfgang Goethe-University, Frankfurt am Main, Germany
Correspondence and requests for reprints should be addressed to Matthias Griese, Kinderpoliklinik, Ludwig-Maximilians-University, Pettenkoferstr 8a, D-80336 Munich, Germany. E-mail: griese{at}pk-i.med.uni-muenchen.de
 |
ABSTRACT
|
|---|
Children with gastroesophageal reflux often suffer from chronic, severe lung damage and recurrent infections. The mechanisms may involve reflux induced lung injury with alterations of the surfactant proteins (SP) SP-A and SP-D, which bind specifically to various microbes and increase their elimination by granular leukocytes and macrophages. In 20 children with gastroesophageal reflux disease (GERD) the bronchoalveolar lavage content and macromolecular organization of SP-A and SP-D was determined by enzyme linked immunosorbent assay and gel chromatography. For comparison, lavages from 17 children without respiratory diseases were investigated. Both, SP-A and SP-D were significantly reduced in children with GERD—median (25, 75 percentiles) SP-A: 362 (169, 494) ng/ml versus 867 (656, 1,761) in control subjects and SP-D: 174 (73, 456) ng/ml versus 518 (295, 748) ng/ml in control subjects. The more active, higher molecular weight oligomers of SP-A and especially those of SP-D were diminished, whereas the smaller sized forms of SP-D were markedly increased. In children with GERD, significantly reduced amounts of SP-A and SP-D and an altered structural organization of the surfactant protein oligomers were demonstrated. Such impairments of central components of the innate host defense system may contribute to the pathogenesis of the chronic lung disease commonly observed in these children.
Key Words: surfactant protein A • surfactant protein D • reflux • bronchoalveolar lavage
|
INTRODUCTION
|
|---|
Gastroesophageal reflux disease (GERD) significantly contributes to chronic and severe respiratory morbidity in both children and adults (1). In children, recurrent bronchopulmonary infections represent the most prominent and debilitating extra esophageal, lower airway problems (2–4). Recurrent pneumonia, chronic cough and frequent episodes of obstructive bronchitis may be the result of gross or microscopic aspirations or a reflex response to acid stimulation of the esophagus, resulting in neuronally and chemically driven chronic bronchopulmonary inflammatory conditions (1). These inflammatory processes might also involve a destruction of the local pulmonary innate host defense system, favoring recurrent bronchopulmonary infections due to a reduced ability for the rapid clearance of microorganisms.
The surfactant proteins (SP) SP-A and SP-D are members of a family of collageneous carbohydrate binding proteins, now commonly known as collectins (5). In vivo data from SP-A deficient mice have demonstrated significantly impaired clearance of respiratory viruses (6) and bacteria (7, 8) in the absence of SP-A. Results on the antimicrobial host defense system in SP-D deficient animals have not yet been presented. However, a large number of in vitro studies have presented details on the interaction between microorganisms and SP-D as well as SP-A (5, 9). Their carbohydrate recognition domains bind to glycoconjugates expressed by a wide variety of microorganisms, facilitating microbial clearance through aggregation of the organisms or other direct effects (5). In addition, SP-A and SP-D modulate leukocyte and macrophage function, enhancing their chemotactic recruitment, respiratory burst, and phagocytosis and killing of microorganisms (9). Furthermore, the macromolecular organization with specific arrangement of each carbohydrate recognition domain, appears to be important for their functional properties. The resulting oligomeric structures consist of covalently linked structures of up to 18 SP-A molecules or up to 12 SP-D molecules. In the case of SP-D, even higher ordered multimers with up to 36 lectin domains are formed. The activity of SP-D in vitro and in vivo is dependent on this oligomeric structure (5, 10). Separation of these various oligomer forms by gel filtration may detect alterations of the macromolecular organization of these collectins occurring with different disease states and potentially directly linked to altered functional properties (11).
The goal of this study was to assess the total concentration and the oligomeric organization of the lung collectins SP-A and SP-D in healthy children and in a group of children with chronic pulmonary disease from gastroesophageal reflux, to generate evidence for the hypothesis of an impaired innate pulmonary defense system in children with GERD.
|
METHODS
|
|---|
Study Subjects
Twenty children who presented with chronic respiratory symptoms nonresponsive to conventional treatments were diagnosed as suffering from gastroesophageal reflux responsible for their symptoms (Table 1). GERD was diagnosed by 24-hour two level pH monitoring (abnormal in 14 of these children), lipid-laden macrophages (12) (abnormal in nine children), an abnormal esophagoscopy and esophageal biopsy, or an upper GI series with reflux higher than the upper third of the esophagus (16 children). Ten presented with recurrent obstructive bronchitis not appropriately responding to ß-agonists and inhaled or systemic steroids. Ten had severe recurrent bronchitis and bronchopneumonia without significant signs of airway obstruction. Cystic fibrosis, primary ciliary dyskinesia,  1-antitrypsin deficiency, allergic disease, and immunodeficiencies had been ruled out. All these children underwent broncho- and esophagoscopy during a period without acute respiratory tract infections. A group of 17 children with no history of allergic or chronic lung disease or any upper or lower respiratory tract infection in the 6 weeks before the study served as a control group. In these children during elective surgery for minor conditions, bronchoalveolar lavage (BAL) was performed (Table 2), using an end-hole catheter wedged in the right lower lobe. In the other children, BAL was performed during rigid bronchoscopy under general anesthesia by wedging the catheter in the lobe that appeared most affected or in the right lower lobe bronchus, whenever the disease was not localized. Three times 1 ml per kg/body weight of 0.9% saline was used. The recovered BAL fluid was the same in the two groups and averaged 57 ± 12%. After an aliquot was taken for the microbiologic studies, the lavage fluid was filtered through gauze and centrifuged at 200 x g for 10 minutes and the cells were analyzed as described (12). The supernatant was used for all the biochemical studies reported. The study protocol was approved by the institutional review board and informed consent from the parents or guardians and older children was obtained before the study.
View this table:
[in this window]
[in a new window]
|
TABLE 1. Results of 24-HOUR ph measurements and lipid laden alveolar macrophages in bronchoalveolar alveolar lavage fluid
|
|
ELISA for SP-A and SP-D
The assays were performed as described previously (13, 14).
Gel Filtration to Determine the Macromolecular Organization of Native SP-A and SP-D in BAL
The separation of SP-A and SP-D isoforms was done as described previously, using an Äkta apparatus (Pharmacia, Uppsala, Sweden) (11).
Sodium Dodecyl Sulfate–Polyacrylamide Gel Electrophoresis and Western Blotting
The corresponding fractions eluted from the gel chromatography columns were pooled, desalted by centrifugation through a 1-kD membrane (Microsep; Filtron Technology Corporation, Northborough, MA), separated under reducing conditions on NuPage Tris-Acetat 3–8% gels (Novex, San Diego, CA), and immunoblotted with an antiserum against native human SP-D (gift of Prof. KBM Reid and Dr. Eggleton, Oxford, UK) (15).
Statistical Analysis
All data are medians, interquartile range (25 and 75 percentile), and [range] from n independent determinations. Correlation analysis was performed by calculating the two-tailed rank Spearman correlation coefficient. Comparisons were made by the two-sided Mann–Whitney U test, p < 0.05 was set as level of significance and exact p values are given (16).
|
RESULTS
|
|---|
The children with GERD had highly pathologic 24-hour two point pH-probe measurements, judged both in relation to our own control group and in relation to data in the literature (Table 1). Although the median lipid-laden alveolar macrophage (LLAM) score was higher in children with GERD, there was a large overlap and this parameter was not significantly different between children with GERD and the control subjects (Table 1). However the cellular composition of the lavages of the two groups of children investigated was different, with a higher percentage of lymphocytes at the expense of macrophages in children with GERD (Table 2). In both groups of children, the number of lavages with a positive bacterial culture was the same. The bacteria were always present in low numbers (< 104 per milliliter) and thus judged as contaminants from the upper airways. No viruses or mycoplasma and chlamydia were detected.
The concentration of total protein did not differ between the two groups (GERD 120 µg/ml (82;201)[46–352] n = 16 versus control subjects 75 µg/ml (60;146) [46–580] n = 15 (p = 0.1491)). However, the concentrations of collectins were significantly reduced in GERD (SP-A 362 ng/ml (169;494) [22–2,118] n = 20 versus control subjects 867 (656;1,761) [220–8,953] n = 17; p < 0.0001 and SP-D 174 ng/ml (73;456) [0–1,128] n = 20 versus control subjects 518 (295;748) [121–976] n = 17; p = 0.0077) (Figure 1)
. The same result was obtained when the surfactant proteins were related to the protein level of the lavages (SP-A/protein 2.6 (1.2;4.4) [0.3–28.9] n = 16 versus healthy control subjects 13.8 (7.9;30.4) [1.2–145] n = 15; p = 0.0015 and SP-D/protein 1.86 (0.38;2.48) [0–10.8] n = 16 versus control subjects 6.09 (4.50;12.1) [0.50–16.2] n = 15; p = 0.0032) (Figure 1).
View larger version (19K):
[in this window]
[in a new window]
|
Figure 1. SP-A and SP-D in lavage samples from healthy control children and from children with GERD. Results are presented as concentrations and as ratios to total protein of the respective lavage sample. Individual data points and the median are given. Comparisons were made using Mann–Whitney U test.
|
|
Gel chromatography was used to investigate the macromolecular organization of the collectins. SP-A eluted in healthy control subjects as major peaks at 7, 10, and 14 ml (Figure 2)
. This is consistent with the normal 18-, 12-, and 6-mer form of oligomers. In GERD, the 18-mer form was consistently and significantly reduced (Figure 2). SP-D eluted in healthy control subjects with major peaks at the void volume at 7 ml and at about 10 ml. This pattern is consistent with the elution of the normal 12-mer form of SP-D at 10 ml. The higher multimeric forms (5), e.g., the 24-mer are eluting with the void volume at 7 ml (Figure 3) . In contrast and consistently in GERD, the majority of the SP-D eluted in the fractions from 14 to 20 ml, consistent with the presence of SP-D monomers or trimers (Figure 3). Alternatively, the material may represent proteolytic degradation products that are still immunoreactive. This was investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of these fractions under reducing conditions. In fractions 14, 16, and 18, but not in 12 and 21 some immunoreactive SP-D fragments with molecular weights of about 30 kD, e.g., about 15 kD lower than the molecular weight of SP-D monomers under reducing conditions, were detected (Figure 4)
. However their quantitative contribution to the total SP-D of these fractions was less than 5% (Figure 4, arrow).
View larger version (27K):
[in this window]
[in a new window]
|
Figure 2. Gel chromatographic separation of lavage samples and detection of SP-A in the individual fractions. The upper part of the figure shows a representation of the oligomeric organization, the structure and the expected molecular weight of SP-A forms. Note that the size and position of the schematic drawings only give a rough orientation of the actual elution pattern from the column. The column was calibrated using a range of standards and their elution peaks are also indicated. In the lower part of the figure, the results from six control subjects and from six patients with GERD are presented as means ± SEM. In some instances error bars are hidden by the symbols. The SP-A content in the fraction at 7 ml (first peak) was different between control subjects and patients with GERD (p = 0.0012). Comparisons were made using Mann–Whitney U test.
|
|
View larger version (30K):
[in this window]
[in a new window]
|
Figure 3. Gel chromatographic separation of lavage samples and detection of SP-D in the individual fractions. The upper part of the figure shows a representation of the oligomeric organization, the structure and the expected molecular weight of SP-D forms. Note that the size and position of the schematic drawings only give a rough orientation of the actual elution pattern from the column. The column was calibrated using a range of standards and their elution peaks are also indicated. In the lower part of the figure, the results from six control subjects and from six patients with GERD are presented as means ± SEM. In some instances error bars are hidden by the symbols. The SP-D content in the fractions at 7 ml (p = 0.0082), 8 ml (p = 0.0140), 10 ml (p = 0.0023), 15 ml (p = 0.0082), and 16 ml (p = 0.0012) was different between control subjects and patients with GERD. The void volume of the column was 7 ml. Comparisons were made using Mann–Whitney U test.
|
|
View larger version (96K):
[in this window]
[in a new window]
|
Figure 4. SP-D detected by immunoblotting under reducing conditions after separation by gel chromatography. The fractions 12, 14, 16, 18, and 21 from five patients with GERD (see Figure 3) were pooled and separated by SDS-PAGE. Note that different amounts of SP-D were applied to each lane. The amounts were estimated from the content measured in each gel chromatographic fraction by ELISA and were 46 ng in lane 12, 74 ng in lane 14, 31 ng in lane 16, 75 ng in lane 18, and 23 ng in lane 21. In lane 21 the estimated amount applied was very low and no SP-D was detected by immunoblotting. The majority of the SP-D was detected at a molecular weight of 41–53 kD. Nonreducible, possibly covalently linked dimers were present at 80–85 kD, trimeric forms at 120 kD and higher oligomers at 160 and 200 kD. The spot at 55 kD in lane 16 is an artifact generated during processing of the gel. The arrow indicates SP-D immunoreactive material clearly below the molecular weight of the monomer, e.g., proteolytic degradation products. For comparison, 50 ng of SP-D in whole BAL from a control child was separated by SDS-PAGE under reducing conditions and SP-D was immunodetected. This lane is shown separately on the left side of the figure and demonstrates a pattern of SP-D similar to that of the children with GERD. Note the different amounts of protein applied to the lanes.
|
|
|
DISCUSSION
|
|---|
Micro-aspiration of gastric or esophageal contents into the airways is believed to be the principal damaging mechanism in GERD leading to chronic pulmonary respiratory symptoms and inflammation. Particularly, pepsin and trypsin have been shown in animal models to be more damaging to the mucosa than acid (17). These stimuli are also known to induce and perpetuate, via axon reflexes, a neurogenic inflammation that is characterized by recruitment and activation of inflammatory cells, e.g., neutrophils and lymphocytes (1). In contrast to BAL data on lipid-laden macrophages, data on the extent of the inflammatory cell pattern is rare. There was moderate but constant lymphocytic infiltrate in this study. This was unlikely related to viral infection as no viruses were detected in BAL. Although half of our patients had obstructive airway symptoms, which are often impossible to differentiate clinically from asthma, the eosinophil count in BAL was normal and no other convincing evidence for allergic airways disease was present.
The mechanisms whereby this chronic cellular infiltration leads to the lower respiratory tract conditions, including chronic and recurrent bronchitis, recurrent pneumonia, lung abscesses, bronchial asthma, and eventually destruction of the lungs or pulmonary fibrosis (1), are largely unknown. We hypothesized that an altered innate immune defense system may be involved, particularly as many of its components have both, antimicrobial and immunoregulatory capacity (5, 18). In this investigation we have focused on the collectins SP-A and SP-D. Clear differences in their BAL concentration and multimeric organization between healthy children and those suffering from GERD were found, making these compounds good candidates to participate as central mechanisms in the pathogenesis of GERD.
The total amounts of SP-A and SP-D were severely reduced in children with GERD, both expressed per ml or per mg protein recovered. Similar findings have previously been reported in patients with cystic fibrosis (13, 19, 20) and support the view of significantly reduced lung collectin functions in this group of patients.
In addition to these quantitative reductions, we also found distinct structural alterations of SP-A and especially SP-D in their nonpurified macromolecular states. Similarly as done previously for SP-A (11), we estimated the amounts of the various oligomers of SP-A and SP-D present in BAL, from their peaks eluting from the column. The allocation of the oligomers to the various peaks was based on the calibration of the column by the molecular weight standards (Figures 3 and 4), in the case of SP-A on the comparison with sucrose density gradient centrifugation (11) and the extensive utilization of the column for the isolation and purification of these proteins under identical conditions (21). SP-A and SP-D are complex molecules composed of polypeptide chains, with a molecular weight of about 30 (SP-A) and 45 (SP-D) kD (Figures 2 and 3). Cysteine residues at the NH2-terminus and in the collagen-like region allow the association of three polypeptide chains and form a collagen triple helix (3-mer). In the case of SP-A, a total of six such (hetero-) 3-mers may associate to form the characteristic "bunch of tulips" structure (Figure 2). In the case of SP-D, four such SP-D (homo-) 3-mers may associate via additional disulfide bonds to form the characteristic cross-like structure (12-mer) (Figure 3). Assembly of these to 24-mer or higher-ordered multimeric structures generates the high affinity binding to carbohydrate-bearing surfaces. In vitro and also in vivo functional activity of the collectins is dependent on the oligomeric structure (5, 10). Depolymerization by oxidation or other means leads to loss of function, e.g., in the case of SP-A to loss of binding to pollen grains (22). In the case of SP-D, in vivo expression in mice of a mutant protein unable to form SP-D oligomers, crosslinked by disulfide bonds, resulted in the development of emphysema and foamy macrophages (10).
In BAL from control children, SP-A was principally present as oligomeric structures composed of 18 or 12 monomers, similar to that previously described in adults (11). In the children with GERD, there was a small but significant increase of the second (12-mer) peak at the expense of the first (18-mer) peak. This was consistent with a minor shift to lower SP-A oligomers. The latter may be a result of oxidation (22).
In the healthy control children, SP-D was also predominantly assembled as the expected 12-mer structure, eluting in fraction 9–10 and in addition as multimeric, e.g., 24- or higher oligomers in fractions 7 and 8. This pattern was not found in GERD, where the majority of the SP-D eluted at a size typical for monomers or potentially also as smaller fragments. The latter possibility was examined by electrophoresis of these column fractions. Under reducing conditions, only a small fraction was present as proteolytic break down products with a molecular weight of about 30 kD. These results clearly demonstrated damage of SP-D, most likely by oxidation leading to depolymerization of the oligomers and to a much smaller extent also by proteolytic degradation. Such biochemical alterations are very likely associated with loss of functions given the close structure–function relationship established for the collections, as described previously. Thus, the data collected in this study support the hypothesis of an impaired innate pulmonary defense system in children with GERD. Both the more direct antimicrobial and the complex immunomodulatory roles these collectins have within the body, very likely contribute to the pathogenesis of the clinical condition in these children. In case additional studies will directly delineate a collectin-dependent loss of function, exogenous replacement is worthwhile to consider in experimental models of this lung disease, for preclinical assessment of their utility in human GERD.
|
Acknowledgments
|
|---|
The technical assistance of A. Schams is appreciated. The authors thank Dr. Hasegawa, Teijin, Yamaguchi, Japan for the anti-SP-A monoclonal antibody PC-6; Dr. Steinhilber, Byk-Gulden, Konstanz, Germany for the rabbit polyclonal anti-human SP-A antibody and human recombinant SP-A; and Prof. Erica Crouch, Department of Pathology, St. Louis, MO for the human recombinant SP-D.
|
FOOTNOTES
|
|---|
This article has an online data supplement, which is accessible from this issue's table of contents online at www.atsjournals.org
Received in original form July 30, 2001;
accepted in final form December 10, 2001
|
REFERENCES
|
|---|
-
Stein MR. Gastroesophageal reflux disease and airway disease. New York: Dekker; 1999.
-
del Rosario JF, Orenstein, S. Evaluation and management of gastroesophageal reflux and pulmonary disease. Curr Opin Pediatr 1996;8:209–215.[Medline]
-
Chen P, Chang M, Hsu S. Gastroesophageal reflux in children with chronic recurrent bronchopulmonary infection. J Pediatr Gastroenterol Nutr 1991;13:16–22.[Medline]
-
Padhy A, Gopinath P, Sharma S, Prasad A, Arora N, Tiwari D, Gupta K, Chetty A. Radionuclide detection of gastroesophageal reflux in children suffering from recurrent lower respiratory tract infection. Indian J Pediatr 1990;57:517–525.[Medline]
-
Crouch E. Collectins and pulmonary host defense. Am J Respir Cell Mol Biol 1998;19:177–210.[Abstract/Free Full Text]
-
LeVine AM, Gwozdz J, Stark J, Bruno M, Whitsett JA, Korfhagen T. Surfactant protein-A enhances respiratory syncytial virus clearance in vivo. J Clin Invest 1999;103:1015–1021.[Medline]
-
LeVine AM, Kurak K, Bruno MD, Stark J, Whitsett JA, Korfhagen TR. Surfactant protein-A-deficient mice are susceptible to pseudomonas aeruginosa infection. Am J Respir Cell Mol Biol 1998;19:700–708.[Abstract/Free Full Text]
-
LeVine AM, Kurak K, Wright JR, Watford WT, Bruno MD, Ross GF, Whitsett JA, Korfhagen TR. Surfactant protein-A binds group B streptococcus enhancing phagocytosis and clearance from lungs of surfactant protein-A-deficient mice. Am J Respir Cell Mol Biol 1999;20:279–286.[Abstract/Free Full Text]
-
Wright JR. Immunomodulatory functions of surfactant. Physiol Rev 1997; 77:931–961.[Abstract/Free Full Text]
-
Zhang L, Ikegami M, Crouch E, Korfhagen T, Whitsett JA. Activity of pulmonary surfactant protein D (SP-D) in vivo is dependent on oligomeric structure. Am J Respir Crit Care Med 2001;163:A729.
-
Hickling T, Malhotra R, Sim RB. Human lung surfactant protein A exists in several different oligomeric states: oligomer size distribution varies between patient groups. Mol Med 1998;4:266–275.[Medline]
-
Ahrens P, Noll C, Kitz R, Willigens P, Zielen S, Hofmann D. Lipid-laden alveolar macrophages (LLAM): a useful marker of silent aspiration in children. Pediatr Pulmonol 1999;28:83–88.[Medline]
-
Griese M, Birrer P, Demirsoy A. Pulmonary surfactant in cystic fibrosis. Eur Respir J 1997;10:1983–1988.[Abstract]
-
Griese M, Maderlechner N, Bufler P. Surfactant proteins D and A in sputum. Eur J Med Res 2001;6:33–38.[Medline]
-
Lu J, Willis C, Reid KM. Purification, characterisation and cDNA cloning of human lung surfactant protein D. Biochem J 1992;284:795–802.
-
Motulsky H. Intuitive biostatistics. New York: Oxford University Press; 1995.
-
Mello CJ. GERD: a major factor in chronic cough. In: Stein MR, editor. Gastroesophageal reflux disease and airway disease. New York: Marcel Dekker; 1999. p. 89–113.
-
Medzhitov R, Janeway C. Advances in immunology: innate immunity. N Engl J Med 2000;343:338–344.[Free Full Text]
-
von Bredow C, Birrer P, Griese M. Surfactant protein A and other bronchoalveolar lavage proteins are altered in cystic fibrosis. Eur Respir J 2001;17:716–722.[Abstract/Free Full Text]
-
Postle AD, Mander A, Reid KM, Wang JY, Wright S, Moustaki M, Warner J. Deficient hydrophilic lung surfactant proteins A und D with normal surfactant phospholipid molecular species in cystic fibrosis. Am J Respir Cell Mol Biol 1999;20:90–98.[Abstract/Free Full Text]
-
Strong P, Kishore U, Morgan C, Lopez Bernal A, Singh M, Reid KBM. A novel method of purifying lung surfactant proteins A and D from the lung lavage of alveolar proteinosis patients and from pooled amniotic fluid. J Immunol Methods 1998;220:139–149.[CrossRef][Medline]
-
Stuart GR, Sim RB, Malhortra R. Characterization of radioiodinated lung surfactant protein A (SP-A) and the effects of oxidation on SP-A quaternary structure and activity. Exp Lung Res 1996;22:467–487.[Medline]
-
Vandenplas Y, Sacre-Smits L. Continuous 24-hour esophageal pH monitoring in 285 asymptomatic infants 0–15 months old. J Pediatr Gastroenterol Nutr 1987;6:220–224.[Medline]
-
Euler AR, Byrne WJ. Twenty-four-hour esophageal intraluminal pH probe testing: a comparative analysis. Gastroenterology 1981;80:957–961.[Medline]
-
Gustafsson PM, Kjellman MN-I, Tibbling L. Bronchial asthma and acid reflux into the distal and proximal oesophagus. Arch Dis Child 1990; 65:1255–1258.[Abstract]
This article has been cited by other articles:
|
|
|
|
 
E. Zecca, D. De Luca, S. Baroni, G. Vento, E. Tiberi, and C. Romagnoli
Bile Acid-Induced Lung Injury in Newborn Infants: A Bronchoalveolar Lavage Fluid Study
Pediatrics,
January 1, 2008;
121(1):
e146 - e149.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
V. Starosta, R. Kitz, D. Hartl, V. Marcos, D. Reinhardt, and M. Griese
Bronchoalveolar Pepsin, Bile Acids, Oxidation, and Inflammation in Children With Gastroesophageal Reflux Disease
Chest,
November 1, 2007;
132(5):
1557 - 1564.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Griese, R. Essl, R. Schmidt, E. Rietschel, F. Ratjen, M. Ballmann, K. Paul, and for the BEAT Study Group
Pulmonary Surfactant, Lung Function, and Endobronchial Inflammation in Cystic Fibrosis
Am. J. Respir. Crit. Care Med.,
November 1, 2004;
170(9):
1000 - 1005.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
F. Brasch, M. Griese, M. Tredano, G. Johnen, M. Ochs, C. Rieger, S. Mulugeta, K.M. Muller, M. Bahuau, and M.F. Beers
Interstitial lung disease in a baby with a de novo mutation in the SFTPC gene
Eur. Respir. J.,
July 1, 2004;
24(1):
30 - 39.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Griese, J. Ramakers, A. Krasselt, V. Starosta, S. van Koningsbruggen, R. Fischer, F. Ratjen, B. Mullinger, R. M. Huber, K. Maier, et al.
Improvement of Alveolar Glutathione and Lung Function but Not Oxidative State in Cystic Fibrosis
Am. J. Respir. Crit. Care Med.,
April 1, 2004;
169(7):
822 - 828.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
T. L. Noah, P. C. Murphy, J. J. Alink, M. W. Leigh, W. M. Hull, M. T. Stahlman, and J. A. Whitsett
Bronchoalveolar Lavage Fluid Surfactant Protein-A and Surfactant Protein-D Are Inversely Related to Inflammation in Early Cystic Fibrosis
Am. J. Respir. Crit. Care Med.,
September 15, 2003;
168(6):
685 - 691.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. J. Tobin
Pediatrics, Surfactant, and Cystic Fibrosis in AJRCCM 2002
Am. J. Respir. Crit. Care Med.,
February 1, 2003;
167(3):
333 - 344.
[Full Text]
[PDF]
|
|
|
Copyright © 2002 American Thoracic Society
|
TOP
ABSTRACT
INTRODUCTION