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Background Optimal functionality of synthetic lung surfactant for treatment of respiratory distress syndrome in preterm infants largely depends on the quality and quantity of the surfactant protein B (SP-B) peptide mimic and the lipid mixture. B-YL peptide is a 41-residue sulfur-free SP-B mimic with its cysteine and methionine residues replaced by tyrosine and leucine, respectively, to enhance its oxidation resistance. Aim Testing the structural and functional stability of the B-YL peptide in synthetic surfactant lipids after long-term storage. Methods The structural and functional properties of B-YL peptide in surfactant lipids were studied using three production runs of B-YL peptides in synthetic surfactant lipids. Each run was held at 5 °C ambient temperature for three years and analyzed with structural and computational techniques, i.e., MALDI-TOF mass spectrometry, ATR-Fourier Transform Infrared Spectroscopy (ATR-FTIR), secondary homology modeling of a preliminary B-YL structure, and tertiary Molecular Dynamic simulations of B-YL in surfactant lipids, and with functional methods, i.e., captive bubble surfactometry (CBS) and retesting in vivo surface activity in surfactant-deficient young adult rabbits. Results MALDI-TOF mass spectrometry showed no degradation of the B-YL peptide as a function of stored time. ATR-FTIR studies demonstrated that the B-YL peptide still assumed stable alpha-helical conformations in synthetic surfactant lipids. These structural findings correlated with excellent in vitro surface activity during both quasi-static and dynamic cycling on CBS after three years of cold storage and in vivo surface activity of the aged formulations with improvements in oxygenation and dynamic lung compliance approaching those of the positive control surfactant Curosurf®. Conclusions The structure of the B-YL peptide and the in vitro and in vivo functions of the B-YL surfactant were each maintained after three years of refrigeration storage.

Circulating immature surfactant protein B (proSP-B) forms emerged as the most reliable lung-specific circulating marker for alveolar-capillary membrane (ACM) dysfunction and for the overall clinical status of heart failure (HF). Notably, in terms of HF hospitalization, immature SP-B overwhelms the prognostic role of other most frequently used clinical parameters such as those related to lung dysfunction. The strong prognostic value of circulating proSP-B in HF suggests more widespread and possible systemic effects. Thus, we assessed the plasma distribution of proSP-B evaluating whether it exists in a lipoprotein-bound form and its impact on lipoprotein structure and function. ProSP-B forms were detectable in high-density lipoprotein (HDL) only. To assess the impact of proSP-B on HDL, HDL from healthy subjects were enriched with proSP-B produced by a stably transfected CHO cell line that specifically expresses and releases the human proSP-B. After enrichment, HDL size and lipoprotein electrophoretic mobility, and protein composition did not show apparent differences. HDL antioxidant capacity (HOI), assessed as their ability to inhibit air-induced LDL oxidation, was impaired after proSP-B enrichment. HOI was also higher in HF patients with respect to age-matched control healthy subjects (p = 0.013). Circulating proSP-B, besides its potential role as a specific marker for ACM dysfunction in HF patients with diagnostic and prognostic value, binds to human HDL impairing their antioxidant capacity. These findings shed light on proSP-B as a molecule that contributes to the reduction of the defense against oxidative stress, a key mediator in the pathogenesis of HF.

Hyperglycemia during pregnancy is associated with fetal lung development disorders and surfactant protein (SP) deficiency. Here, we examined the role of FOXA2 and Akt signaling in fetal lung development during diabetic pregnancy. Sprague-Dawley rats were injected with streptozocin (STZ) during pregnancy to induce diabetes (DM). DM-exposed fetal lungs exhibited reduced numbers of alveoli, irregularities in the appearance and thickness of the alveolar septum, increased levels of glycogen and lipids in type II alveolar epithelial cells, fewer microvilli and mature lamellar bodies, and swollen mitochondria. SP-B and SP-C in DM amniotic fluid and DM lungs were lower than in the control group (P < 0.05). DM lung nuclear FOXA2 was lower compared with the control group (P < 0.05), but p-FOXA2 was higher (P < 0.05). In murine lung epithelial (MLE) 12 cells, p-AKT levels were increased by high glucose/insulin, but decreased by the Akt inhibitor MK2206 (P < 0.05). Expression of nuclear FOXA2 was increased by MK2206 compared with the high glucose/insulin group (P < 0.05). These results suggest that maternal diabetes induces fetal lung FOXA2 phosphorylation through the Akt pathway, and also affects the maturation of alveolar epithelial cells and reduces levels of SP-B and SP-C in the fetal lungs. An Akt inhibitor reversed the changes in SP expression in vitro.

Background: The aim of this prospective study was to investigate the influence of long-term physical activity on HDL quality, reflected by serum amyloid A (SAA) and surfactant protein B (SPB). Methods and results: 109 healthy subjects were recruited, 98 completed the study. Participants perform within the calculated training pulse for 8 months. The performance gain was measured/quantified by bicycle stress tests at the beginning and end of the observation period. SAA and SPB were measured at baseline and after 4 and 8 months by ELISA. In contrary to HDL-quantity, there was no sports-induced change in SAA or SPB observable. However, significant predictors for SPB-levels were smoking status, BMI and weekly alcohol consumption and for SAA weekly alcohol consumption together with sex and hsCRP-levels. Conclusions: Long-term physical activity increases HDL-quantity but has no impact on HDL-quality reflected by SAA and SPB. Smoking is associated with higher SPB-levels and the weekly alcohol intake is associated with both higher SAA and SPB-levels suggesting a damaging effect of smoking and drinking alcohol on the HDL-quality. We assume that HDL-quality is at least as important as HDL-quantity when investigating the role of HDL in (cardiovascular) disease and should receive attention in further studies dealing with HDL.

Cigarette smoking is a major independent risk factor for cardiovascular diseases (CVD). The underlying mechanisms, however, are not clearly understood. Lungs are the primary route of exposure to smoke, with pulmonary cells and surfactant being the first structures directly exposed, resulting in the leakage of the immature proteoform of surfactant protein B (proSP-B). Herein, we evaluated whether proSP-B joined the cargo of high-density lipoprotein (HDL) proteins in healthy young subjects (n = 106) without any CVD risk factor other than smoking, and if HDL-associated proSP-B (HDL-SPB) correlated with pulmonary function parameters, systemic inflammation, and oxidative stress. At univariable analysis, HDL-SPB resulted significantly higher in smokers (2.2-fold, p &lt, 0.001) than in non-smokers. No significant differences have been detected between smokers and non-smokers for inflammation, oxidation variables, and alveolar-capillary diffusion markers. In a multivariable model, HDL-SPB was independently associated with smoking. In conclusion, HDL-SPB is not only a precocious and sensitive index of the acute effects of smoke, but it might be also a potential causal factor in the onset of the vascular damage induced by modified HDL. These findings contribute to the emerging concept that the quality of the HDL proteome, rather than the quantity of particles, plays a central role in CVD risk protection.

Growing interest raised on circulating biomarkers of structural alveolar–capillary unit damage and very recent data support surfactant protein type B (SP-B) as the most promising candidate in this setting. With respect to other proteins proposed as possible markers of lung damage, SP-B has some unique qualities: it is critical for the assembly of pulmonary surfactant, making its lack incompatible with life; it has no other known site of synthesis except alveolar epithelial cells different from other surfactant proteins; and, it undergoes a proteolytic processing in a pulmonary-cell-specific manner. In the recent years circulating SP-B isoforms, mature or immature, have been demonstrated to be detectable in the circulation depending on the magnitude of the damage of alveolar capillary membrane. In the present review, we summarize the recent knowledge on SP-B regulation, function and we discuss its potential role as reliable biological marker of alveolar capillary membrane (dys)function in the context of heart failure.

Pulmonary surfactant reduces surface tension in the lung and prevents alveolar collapse. Following a deep inspiration (DI), respiratory elastance first drops then gradually increases due to surface film and tissue viscoelasticity. In acute lung injury (ALI), this increase is faster and governed by alveolar collapse due to increased surface tension. We hypothesized that the rate of increase in elastance reflects the deficiency of surfactant in the lung. To test this, mice were ventilated before (baseline) and after saline lavage obtained by injecting 0.8 ml and withdrawing 0.7 ml fluid (severe ALI) or injecting 0.1 ml (mild ALI). After two DIs, elastance was tracked for 10 min followed by a full lavage to assess surfactant proteins B (SP-B) and C (SP-C) content. Following 2 DIs, the increases in elastance during 10 min ventilation (Δ H) were 3.60 ± 0.61, 5.35 ± 1.04, and 8.33 ± 0.84 cmH2O/ml in baseline mice and mice with mild and severe ALI, respectively ( P < 0.0001). SP-B and SP-C in the lavage fluid dropped by 32.4% and 24.9% in the mild and 50.4% and 39.6% in the severe ALI, respectively. Furthermore, Δ H showed a strong negative correlation with both SP-B ( r2= 0.801) and SP-C ( r2= 0.810) content. The Δ H was, however, much smaller when the lavage fluid also contained exogeneous SP-B and SP-C. Thus Δ H can be interpreted as an organ level measure of surface film functionality in lavage-induced ALI in mice. This method could prove useful in clinical situations such as diagnosing surfactant problems, monitoring recovery from lung injury or the effectiveness of surfactant therapy.

PubMedID: 28481742 Background: Alveolar-capillary membrane damage develops as a result of the inflammatory effect of cardiopulmonary bypass (CPB). In the presence of a healthy alveolar-capillary barrier, there is little or no surfactant in the blood. The aim of this study was to evaluate the protective effects of ultraprotective ventilation during CPB by measuring serum and bronchoalveolar lavage (BAL) surfactant protein B (SPB) values in congenital heart surgery. Methods: This prospective study was designed for 46 patients with congenital heart defects. Patients were classified into two groups: group 1 comprising pulmonary normotensive patients and group 2 consisting of pulmonary hypertensive (PH) patients. Each group was divided into two sub-groups: (a) those who received ultraprotective ventilation during CPB and (b) those who did not receive ultraprotective ventilation during CPB. Serum SPB (S-SPB) values were measured preoperatively (ST1); at the fourth hour postop (ST2); and at the 24th hour postop (ST3). BAL SPB values were measured preoperatively (BT1); and at the fourth hour postop (BT2). Results: ST1, ST2, and ST3 values of group 1a (pulmonary normotensive ventilated patients) and group 1b (pulmonary normotensive non-ventilated patients) were much lower than those of group 2a (pulmonary hypertensive ventilated patients) and group 2b (pulmonary hypertensive non-ventilated patients) (P < .05). The evaluation of ST1, ST2, and ST3 values between groups 1a and 1b did not show statistically significant differences. When comparing ST1 to ST3, a decrease in value was observed in group 1a (32.28 ± 13.27 ng/mL to 19.38 ± 7.6 ng/mL) (P = .006). In Group 1b, values increased between ST1 and ST2 before decreasing from ST2 to ST3; however, the ST3 values were still higher than their ST1 counterparts. It was recorded that there was no statistically significant difference between the ST1, ST2, and ST3 values of group 2a and group 2b. A comparison of the BT1 and BT2 values in groups also yielded no statistically significant differences. Conclusion: Although pulmonary hypertension is known to result in lung injury, this study is important as it shows that ultraprotective ventilation protects the alveolar-capillary barrier in pulmonary normotensive congenital heart patients. © 2017 Forum Multimedia Publishing, LLC.

Takcı Ş, Anuk-İnce D, Louha M, Couderc R, Çakar N, Köseoğlu RD, Ateş Ö. A rare large mutation involving two exons of the SP-B gene in an infant with severe respiratory distress. Turk J Pediatr 2017; 59: 483-486. Hereditary surfactant protein-B (SP-B) deficiency is a rare autosomal recessive disease of newborn infants causing severe respiratory failure and death within the first year of life. The most common cause of SP-B deficiency is a frameshift mutation in exon 4 (121ins2) in the gene encoding SP-B. We report a term infant with unremitting respiratory distress who was unresponsive to all treatment modalities. The parents were consanguineous and a term sibling of the infant had died due to respiratory failure without a certain diagnosis. In the first step of the diagnostic work-up, common genetic mutations for SP-B, surfactant protein C and ATP-binding cassette s3 were absent, however sequencing of SP-B gene revealed a large homozygous genomic deletion covering exon 8 and 9. In this case report, we aimed to emphasize further genetic evaluation in all cases suggestive of surfactant dysfunction, even if common mutations are absent.

Background Alveolar Type II cell transplantation has been proposed as a cell therapy for the treatment of idiopathic pulmonary fibrosis. Its long-term benefits include repair of lung fibrosis, but its success partly depends on the restoration of lung homeostasis. Our aim was to evaluate surfactant protein restoration after alveolar Type II cell transplantation in an experimental model of bleomycin-induced lung fibrosis in rats. Methods Lung fibrosis was induced by intratracheal instillation of bleomycin. Alveolar Type II cells were obtained from healthy animals and transplanted 14 days after bleomycin was administered. Furthermore, one group transplanted with alveolar macrophages and another group treated with surfactant were established to evaluate the specificity of the alveolar Type II cell transplantation. The animals were euthanized at 21 days after bleomycin instillation. Lung fibrosis was confirmed by a histologic study and an evaluation of the hydroxyproline content. Changes in surfactant proteins were evaluated by mRNA expression, Western blot and immunofluorescence studies. Results The group with alveolar Type II cell transplantation was the only one to show a reduction in the degree of lung fibrosis and a complete recovery to normal levels of surfactant proteins. Conclusion One of the mechanisms involved in the beneficial effect of alveolar Type II cell transplantation is restoration of lung surfactant protein levels, which is required for proper respiratory function. © 2014 International Society for Heart and Lung Transplantation., This work was supported by Grant FIS PS09/02362 (Spanish Ministry of Health), by MTV3122410, by SEPAR (Sociedad Española de Neumología y Cirugía Torácica) and by FUCAP. Raquel Guillamat-Prats was supported by a Grant from CIBERES (Centro de investigaciones Biomédicas en Red de Enfermedades Respiratorias)

Background: Our prior studies of lung cancer suggested that a novel biomarker (pro-surfactant protein B or pro-SFTPB) might serve as a predictive marker for this disease. We aimed to determine the potential use of pro-SFTPB for distinguishing lung cancer cases from matched controls as a risk marker. Methods: Study subjects were drawn from the longitudinal Physicians' Health Study (PHS). Cases (n = 188) included individuals who were cancer-free at study enrollment but developed lung cancer during follow-up. Controls (n = 337) were subjects who did not develop lung cancer. Cases and controls were matched on date of study enrollment, age at enrollment, and smoking status and amount. Baseline plasma samples drawn at enrollment were analyzed for pro-SFTPB using ELISA to detect differences in protein expression levels for cases and controls. Results: Pro-SFTPB nondetectable status was significantly associated with lung cancer risk [OR = 5.88; 95% confidence interval (CI) 1.24–27.48]. Among subjects with detectable levels of the protein, increasing plasma concentration of pro-SFTPB was associated with higher lung cancer risk (OR = 1.41 per unit increase in log pro-SFTPB; 95% CI 1.08–1.84). Conclusion: These results suggest a nonlinear, J-shaped association between plasma pro-SFTPB levels and lung cancer risk, with both nondetectable and higher levels of the marker being associated with lung cancer. Impact: These results show promise of a risk marker that could contribute to predicting risk for lung cancer development and to narrowing the high-risk population for low-dose computed tomography screening. Cancer Epidemiol Biomarkers Prev; 22(10); 1756–61. ©2013 AACR.

Surfactant protein B (SP-B) deficiency has become increasingly recognized as a cause of severe prolonged respiratory distress. However, little has been reported with regard to the genetic variability of SP-B in Chinese infants with neonatal respiratory distress syndrome (RDS). One case of a Chinese male infant with neonatal RDS was analyzed for clinical manifestation and genetic variability of SP-B. The clinical manifestations, including grunting, intercostal retractions, nasal flaring, cyanosis and tachypnea were discovered in the physical examination. The initial chest X-ray indicated hyper-inflation, diffuse opacification and air bronchogram of the lungs. Pathological tests of lung tissue revealed RDS and SP-B deficiency. Atelectasis and pneumonedema were observed in the lobes of the lung. Molecular analysis of genomic DNA revealed a mutation of 121del2 in intron 4 of the SP-B gene. In conclusion, the variant in intron 4 of the SP-B gene was associated with neonatal RDS in a Chinese male infant.

Aims: To investigate the presence of surfactant protein (SP) A, B, C and D in nasal airways and to determine whether the proteins exert their main functions in nasal secretions or in the deeper layers of the nasal mucosa. Methods: Volunteers were recruited from the Department of ENT Head and Neck Surgery, Odense University Hospital, Denmark. The study included 39 subjects. Nasal mucosal biopsies were analyzed by immunohistochemistry, and bronchoalveolar and nasal lavages, nasal brush biopsies and nasal mucus were analyzed for SP-A, -B, -C and -D by SDS-PAGE and Western blotting. The presence of SP-A and SP-D in the first three samplings were also analyzed by enzyme-linked immunosorbent assay. Results: In nasal mucosal biopsies, SP-A, -B, -C and -D were all demonstrated in the serous acini of the submucosal glands and in the surface epithelium. SP-D was detected in nasal brush biopsies, whereas the other SPs were absent. Moreover, SP-A, -B, -C and -D were absent in nasal lavage and mucus. Conclusion: SP-A, -B, -C and -D exert their protective effect in the ductal epithelium of the submucosal glands rather than in nasal secretions and mucus. Further studies are required to clarify the functions of these proteins in nasal secretory pathways for understanding upper airway diseases. i 2014 S. Karger AG, Basel

The first successful trial of surfactant treatment for respiratory distress syndrome (RDS) was reported in 1980. Since then there have been numerous randomised trials demonstrating first, the efficacy of surfactant treatment in reducing pulmonary air leaks and increasing survival and second, assessing various other aspects of therapy. These studies show that multiple doses may be needed if surfactant is used to treat established RDS but early or prophylactic treatment is superior for infants with gestational ages less than 30 weeks. Natural surfactants (containing proteins) are more effective than synthetic products (protein free), the latter now being infrequently used. Natural surfactants vary and should not be considered to be equivalent in their effects. A porcine surfactant (poractant alfa) acts more rapidly than a bovine preparation (beractant) in infants with moderate to severe RDS. A meta-analysis of 5 comparative studies suggests that a dose of 200 mg/kg of poractant alfa is associated with lower mortality compared with 100 mg/kg of beractant. Chronic lung disease remains a problem but it is hoped that early treatment with surfactant combined with extubation to continuous positive airway pressure will reduce this complication of prematurity. The newer synthetic surfactants, containing analogues of surfactant protein B or C, have undergone some trials for treatment of RDS but comparative studies which have just been published do not show that they are superior to existing natural surfactants. However, as they are more resistant to inactivation they may have a role in treatment of adult or acute RDS. The last 25 years have seen a large increase in basic science research on surfactants with determination of the structure and function of the four surfactant proteins probably being the most important advances. Future studies will focus on widening the indications for surfactant treatment, developing non-invasive means of administration and assessing the role of the newer synthetic surfactants.

Chronic heart failure (CHF) is associated with adaptive structural changes at the alveolocapillary barrier that may be associated with altered protein permeability. Bidirectional protein movement across the barrier was studied in anesthetized rats with infarct-induced CHF by following125I-labeled albumin (125I-albumin) flux into the alveoli and the leakage of surfactant protein (SP)-B from the alveoli into the circulation. Three groups were studied: controls [0% left ventricular (LV) infarction], moderate infarct (25–45% LV infarction), and large infarct (>46% LV infarction). Wet and dry lung weights increased in the large infarct group (both P < 0.001), consistent with increased lung water and solid lung tissue.125I-albumin flux increased across the endothelial ( P < 0.001) and epithelial ( P < 0.01) components of the alveolocapillary barrier in the large infarct group. Plasma SP-B increased 23% with moderate infarcts ( P < 0.05) and 97% with large infarcts ( P < 0.001), independent of alveolar levels. Lavage fluid immune cells ( P < 0.01) and myeloperoxidase activity ( P < 0.05) increased in the large infarct group, consistent with inflammation. Bidirectional protein movement across the alveolocapillary barrier is increased in CHF, and alveolar inflammation may contribute to this pathophysiological defect.

Software advancements in the last several years have had a significant impact on proteomics from method development to data analysis. Herein, we detail a method, which uses our in-house developed software tool termed Skyline, for empirical refinement of candidate peptides from targeted proteins. The method consists of four main steps from generation of a testable hypothesis, method development, peptide refinement, to peptide validation. The ultimate goal is to identify the best performing peptide in terms of ionization efficiency, reproducibility, specificity, and chromatographic characteristics to monitor as a proxy for protein abundance. It is important to emphasize that this method allows the user to perform this refinement procedure in the sample matrix and organism of interest with the instrumentation available. Finally, the method is demonstrated in a case study to determine the best peptide to monitor the abundance of surfactant protein B in lung aspirates.

Background Patients with Adult Respiratory Distress Syndrome (ARDS) and Acute Lung Injury (ALI) have low concentrations of disaturated-phosphatidylcholine and surfactant protein-B in bronchoalveolar lavage fluid. No information is available on their turnover. Objectives To analyze disaturated-phosphatidylcholine and surfactant protein-B turnover in patients with ARDS/ALI and in human adults with normal lungs (controls). Methods 2H2O as precursor of disaturated-phosphatidylcholine-palmitate and 113C-Leucine as precursor of surfactant protein-B were administered intravenously to 12 patients with ARDS/ALI and to 8 controls. Disaturated-phosphatidylcholine and surfactant protein-B were isolated from serial tracheal aspirates, and their fractional synthetic rate was derived from the 2H and 13C enrichment curves, obtained by gas chromatography mass spectrometry. Disaturated-phosphatidylcholine, surfactant protein-B, and protein concentrations in tracheal aspirates were also measured. Results 1) Surfactant protein-B turned over at faster rate than disaturated-phosphatidylcholine both in ARDS/ALI patients and in controls. 2) In patients with ARDS/ALI the fractional synthesis rate of disaturated-phosphatidylcholine was 3.1 times higher than in controls (p < 0.01), while the fractional synthesis rate of surfactant protein-B was not different. 3) In ARDS/ALI patients the concentrations of disaturated-phosphatidylcholine and surfactant protein-B in tracheal aspirates were markedly and significantly reduced (17% and 40% of the control values respectively). Conclusions 1) Disaturated-phosphatidylcholine and surfactant protein-B have a different turnover both in healthy and diseased lungs. 2) In ARDS/ALI the synthesis of these two surfactant components may be differently regulated.

Background— Surfactant protein type B (SPB) is needed for alveolar gas exchange. SPB is increased in the plasma of patients with heart failure (HF), with a concentration that is higher when HF severity is highest. The aim of this study was to evaluate the relationship between plasma SPB and both alveolar-capillary diffusion at rest and ventilation versus carbon dioxide production during exercise. Methods and Results— Eighty patients with chronic HF and 20 healthy controls were evaluated consecutively, but the required quality for procedures was only reached by 71 patients with HF and 19 healthy controls. Each subject underwent pulmonary function measurements, including lung diffusion for carbon monoxide and membrane diffusion capacity, and maximal cardiopulmonary exercise test. Plasma SPB was measured by immunoblotting. In patients with HF, SPB values were higher (4.5 [11.1] versus 1.6 [2.9], P =0.0006, median and 25th to 75th interquartile), whereas lung diffusion for carbon monoxide (19.7�4.5 versus 24.6�6.8 mL/mm Hg per min, P P P P P P P =0.004), and ventilation/carbon dioxide production slope (β, 0.25; SE, 0.026; P =0.034) were independently associated with SPB. Conclusion— Circulating plasma SPB levels are related to alveolar gas diffusion, overall exercise performance, and efficiency of ventilation showing a link between alveolar-capillary barrier damage, gas exchange abnormalities, and exercise performance in HF.

Whether surfactant protein B (SP-B)-18A/C and 1580C/T polymorphism were associated with susceptibility to chronic obstructive pulmonary disease (COPD) in Chinese Han population was investigated. After genomic DNA was isolated from blood of COPD smokers and control smokers, the genotypes of SP-B-18A/C and SP-B1580C/T polymorphism loci were determined by polymerase chain reaction-restriction fragment length polymorphism analysis (PCR-RFLP) respectively. The results showed that there was significant difference in genotypes distribution frequency of SP-B1580C/T polymorphism locus between COPD smokers and control smokers. C-->T mutation rate (including TT homozygote and CT heterozygote) in COPD smokers was higher than in control smokers (57.9% vs 41.7%, chi2 = 4.93, P

OBJECTIVE To determine if high-frequency oscillatory ventilation and neuromuscular blockade improve oxygenation and chest radiographic appearance more effectively than high-frequency oscillation alone for surfactant protein-B (SP-B)--deficient infants. STUDY DESIGN We reviewed medical records and chest radiographs of five SP-B--deficient infants awaiting lung transplantation. Changes in FiO2 and radiographic scores were analyzed with respect to neuromuscular blockade status. RESULTS FiO2 consistently increased 0.20 (SD 0.11) during high-frequency ventilation without neuromuscular blockade (p = 0.02) and decreased 0.14 (SD 0.11) during high-frequency ventilation with neuromuscular blockade (p = 0.05). Chest radiographic appearance, quantified by an expansion/aeration index, consistently deteriorated without neuromuscular blockade (p = 0.01) and consistently improved with neuromuscular blockade (p = 0.03). Changes in FiO2 correlated with changes in radiograph scores (r = 0.7, p < 0.001). CONCLUSIONS High-frequency ventilation with neuromuscular blockade optimizes oxygenation for SP-B--deficient infants. This ventilatory strategy should be considered while awaiting the diagnosis of SP-B deficiency or lung transplantation.

Background. Chemical spills are on the rise and inhalation of toxic chemicals may induce chemical acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Although the pathophysiology of ALI/ARDS is well understood, the absence of specific antidotes has limited the effectiveness of therapeutic interventions. Objectives. Surfactant inactivation and formation of free radicals are important pathways in (chemical) ALI. We tested the potential of lipid mixtures with advanced surfactant protein B and C (SP-B and C) mimics to improve oxygenation and lung compliance in rabbits with lavage- and chemical-induced ALI/ARDS. Methods. Ventilated young adult rabbits underwent repeated saline lung lavages or underwent intratracheal instillation of hydrochloric acid to induce ALI/ARDS. After establishment of respiratory failure rabbits were treated with a single intratracheal dose of 100 mg/kg of synthetic surfactant composed of 3% Super Mini-B (S-MB), a SP-B mimic, and/or SP-C33 UCLA, a SP-C mimic, in a lipid mixture (DPPC:POPC:POPG 5:3:2 by weight), the clinical surfactant Infasurf®, a bovine lung lavage extract with SP-B and C, or synthetic lipids alone. End-points consisted of arterial oxygenation, dynamic lung compliance, and protein and lipid content in bronchoalveolar lavage fluid. Potential mechanism of surfactant action for S-MB and SP-C33 UCLA were investigated with captive bubble surfactometry (CBS) assays. Results. All three surfactant peptide/lipid mixtures and Infasurf equally lowered the minimum surface tension on CBS, and also improved oxygenation and lung compliance. In both animal models, the two-peptide synthetic surfactant with S-MB and SP-C33 UCLA led to better arterial oxygenation and lung compliance than single peptide synthetic surfactants and Infasurf. Synthetic surfactants and Infasurf improved lung function further in lavage- than in chemical-induced respiratory failure, with the difference probably due to greater capillary-alveolar protein leakage and surfactant dysfunction after HCl instillation than following lung lavage. At the end of the duration of the experiments, synthetic surfactants provided more clinical stability in ALI/ARDS than Infasurf, and the protein content of bronchoalveolar lavage fluid was lowest for the two-peptide synthetic surfactant with S-MB and SP-C33 UCLA. Conclusion. Advanced synthetic surfactant with robust SP-B and SP-C mimics is better equipped to tackle surfactant inactivation in chemical ALI than synthetic surfactant with only a single surfactant peptide or animal-derived surfactant.

Background: Whether congenital diaphragmatic hernia (CDH) is associated with surfactant deficiency or dysfunction is controversial. Aims: To measure disaturated phosphatidylcholine (DSPC) and surfactant protein B (SP-B) synthesis and metabolism in infants with CDH. Methods: DSPC and SP-B amounts and kinetics were studied in tracheal aspirates (TA) of 12 infants with CDH (BW 2978±447g, GA 38±2 wk) and in 8 GA-matched control infants (BW 3160±350g, GA 38±2 wk). Seventeen infants received a 24h infusion of 13C-leucine, an i.v. bolus of 2H2O and 0.0625% of fluid intake as 2H2O every 12h over the next 48h. Three infants received only 13C-leucine infusion. DSPC and SP-B were isolated from TA. DSPC amounts, 2H-palmitate and 13C-leucine enrichments were measured by gas chromatography mass spectrometry. Results: DSPC amount and kinetics have been measured in 17 newborns, and SP-B kinetics in 18. DSPC median (interquartile range) fractional synthesis rate (FSR) was 5.0 %/day (3.5-8.5) in CDH patients vs 6.1 %/day (5.8-7.0) in controls (p=0.31). DSPC secretion time (ST) was 10.7h (6.9-11.5) vs 7.9h (5.2-14.0) (p=0.65). SP-B FSR was 33.4 %/day (28.4-42.9) vs 52.0 %/ day (40.0-83.4) (p=0.03); SP-B peak time was 26h (24-32) vs 18h (15-21) (p=0.02), both significantly lower in the CDH group. SP-B ST was 6.1h (4.0- 9.9) vs 2.7h (1.1-7.1) (p=0.24), and half life 7.5h (5.2-9.1) vs 11.1h (5.8-17.3) (p=0.33). Conclusions: Decreased and delayed SP-B synthesis was found in newborns with CDH compared to controls while DSPC kinetics was similar in both groups, which may contribute to severe respiratory failure in these patients.

Grossmann, Gertie, Yasuhiro Suzuki, Bengt Robertson, Tsutomu Kobayashi, Per Berggren, Wen-Zhi Li, Guo-Wei Song, and Bo Sun.Pathophysiology of neonatal lung injury induced by monoclonal antibody to surfactant protein B. J. Appl. Physiol. 82(6): 2003–2010, 1997.—Near-term newborn rabbits were exposed via the airways to a monoclonal antibody to surfactant protein B and ventilated for 0–120 min. Control animals received nonspecific rabbit or mouse immunoglobulin G, saline, or no material via the airways. Administration of the antibody at ≥40 mg/kg elicited an immediate, significant fall in lung-thorax compliance associated with progressive intra-alveolar edema and/or alveolar collapse and necrosis and desquamation of airway epithelium, and hyaline membranes. The vascular-to-alveolar leak of human albumin and human immunoglobulin G, injected intravenously at birth and determined in lung lavage fluid 60–120 min after instillation of the antibody, was 1.8% for the left lung, with no difference between the markers. The average leak in control animals ventilated for 120 min was

Alveolar surfactant is fundamental for normal lung function. We recently reported increased concentrations of surfactant protein A (SP-A) in serum from patients with acute respiratory failure (ARF). Since surfactant protein B (SP-B) is synthesised as a precursor (approximately 42 kDa) considerably smaller than alveolar (A) SP-A (approximately 650 kDa) and since little is known about surfactant status in patients with ARF, the aims of this study were to determine whether SP-B enters the circulation more readily than SPA and to examine surfactant composition in the injured lung.

The effect of the addition of surfactant protein (SP)-B or SP-B plus SP-C (SP-BC) to a surfactant made from bovine lung (Survanta) was evaluated in 27-d-gestation preterm rabbits. The animals were treated with Survanta, Survanta + 2% SP-B, Survanta + 3% SP-BC, or sheep surfactant. They were then ventilated with 3 cm H2O positive end-expiratory pressure and tidal volumes of 8 mL/kg. Survanta + 2% SP-B was prepared by adding SP-B in water to Survanta or by adding SP-B in chloroform [SP-B(Chl)] to lipid-extracted Survanta. Dynamic compliances of the Survanta + 2% SP-B(Chl)- and Survanta + 3% SP-BC-treated rabbits were greater (p < 0.05) than those treated with Survanta or Survanta + 2% SP-B in water and were comparable to sheep surfactant. Postventilation pressure-volume curves for the groups treated with Survanta supplemented with SP-B had significantly larger retained volumes on deflation compared with those treated only with Survanta (p < 0.01). The effects of ventilation style on the responses were assessed by ventilating other groups of rabbits treated with Survanta, Survanta + 0.5% SP-B(Chl), Survanta + 2% SP-B(Chl), or sheep surfactant with tidal volumes of 10 mL/kg and 0 cm H2O positive end-expiratory pressure. SP-B (2%) augmented the in vivo function of Survanta without positive end-expiratory pressure, and 0.5% SP-B had no effect. Infasurf, a surfactant with more SP-B, was more effective than Survanta when tested in the preterm rabbits. SP-B is a critical factor for optimum immediate surfactant function.

Introduction: Accurate staging of mediastinal lymph nodes guides decisions in the choice of treatment of NSCLC. Unfortunately, reported sensitivity for mediastinoscopy ranges from 40%–89%, using standard pathologic techniques. Our objective was to develop molecular techniques to improve sensitivity and to apply these methods intraoperatively such that mediastinoscopy and tumor resection can potentially be performed in one procedure when the mediastinum is negative for disease. Methods: Approximately 40 markers were screened for expression in 6 primary tumors and 10 benign lymph nodes. From these, 6 markers that showed high expression in primary tumors and at least 500 fold lower expression in benign nodes were chosen for a secondary screening in 22 primary tumors, 21 positive lymph nodes and 22 benign lymph nodes to assess sensitivity and specificity. In collaboration with Cepheid, we have developed and tested a fully integrated, automated instrument (the GeneXpert) that is capable of performing both RNA isolation and QRT-PCR in less than 35 minutes. To demonstrate the feasibility of intraoperative staging, 5-micron sections were cut from OCT embedded tissues from a set of 6 positive, 6 negative, and 6 benign nodes and analyzed on the GeneXpert. Results: We identified 6 markers with good potential for lymph node analysis. Using an expression level cutoff equal to the highest expression in the benign lymph nodes and thus yielding 100% specificity, the following sensitivities were achieved for each marker respectively: carcinoembryonic antigen (CEA) (95.2%), cytokeratin 19 (CK19) (100%), lung-specific X protein (LUNX) (61.9%), novel marker LC-1 (61.9%), surfactant protein B (SFTPB) (57.1%), and TACSTD-1 (100%). Using TACSTD-1 as the marker, the fully automated GeneXpert assay (completed in 35 minutes) clearly discriminated positive from negative nodes. Conclusions: We evaluated molecular markers for their ability to detect nodal disease in NSCLC. In addition, we have developed instrumentation that allows rapid, automated molecular analysis of lymph nodes. The combination of the appropriate markers with this technology could potentially provide the ability to detect occult nodal disease, allowing for accurate intraoperative analysis of mediastinal lymph nodes, and enabling the surgeon to determine operability at the time of the original procedure.

Background :T he surfactant specific proteins, SP-B and SP-C are believed to be important regulators of the surfactant function and homeostasis. Since acute respiratory distress syndrome(ARDS) is usually viewed as the functional and morphological expression of a similar underlying lung injury caused by a variety of insults, and since abnormalities in the surfactant function have been described in ARDS, the authors investigated the different effects of endotoxin and thiourea on the accumulation of mRNA encoding SP-B and SP-C. Methods : Sprague-Dawley rats were given 5 mg/kg of an intraperitoneal endotoxin from Salmonella enteritidis and 3.5 mg/kg intraperitoneal thiourea and were sacrificed at different time periods. Results : 1. The SP-B mRNA levels 6 and 24 hours after the 5 ㎎/㎏ endotoxin treatment was significantly reduced by 26.1% and 50%, respectively(P

Hyaluronan Binding Peptide Limits Surfactant Dysfunction, Respiratory Distress and Surfactant Protein-B and -C Deficiency after Acute Lung Injury

7596 Background: The detection of CTCs in the peripheral blood of cancer patients is of great interest in oncology but remains technically challenging. Molecular methodologies such as QRT-PCR are h...