Exhaled breath condensate: methodological recommendations and unresolved questions

Collection of exhaled breath condensate (EBC) is a noninvasive method for obtaining samples from the lungs. EBC contains large number of mediators including adenosine, ammonia, hydrogen peroxide, isoprostanes, leukotrienes, nitrogen oxides, peptides and cytokines. Concentrations of these mediators are influenced by lung diseases and modulated by therapeutic interventions. Similarly EBC pH also changes in respiratory diseases. The aim of the American Thoracic Society/European Respiratory Society Task Force on EBC was to identify the important methodological issues surrounding EBC collection and assay, to provide recommendations for the measurements and to highlight areas where further research is required. Based on the currently available evidence and the consensus of the expert panel for EBC collection, the following general recommendations were put together for oral sample collection: collect during tidal breathing using a noseclip and a saliva trap; define cooling temperature and collection time (10 min is generally sufficient to obtain 1-2 mL of sample and well tolerated by patients); use inert material for condenser; do not use resistor and do not use filter between the subject and the condenser. These are only general recommendations and certain circumstances may dictate variation from them. Important areas for future research involve: ascertaining mechanisms and site of exhaled breath condensate particle formation; determination of dilution markers; improving reproducibility; employment of EBC in longitudinal studies; and determining the utility of exhaled breath condensate measures for the management of individual patients. These studies are required before recommending this technique for use in clinical practice.

Experience with inhaled iloprost and bosentan in portopulmonary hypertension

Novel treatments, such as prostanoids or endothelin receptor antagonists, have been introduced for various forms of pulmonary arterial hypertension, but the long-term effects of these treatments on portopulmonary hypertension (PPHT) are unknown. In a retrospective analysis, the present authors assessed the safety and efficacy of inhaled iloprost, a prostacyclin analogue, and bosentan, an endothelin receptor antagonist, in patients with PPHT. In total, 31 consecutive patients with Child class A or B cirrhosis and severe PPHT were treated for up to 3 yrs with either inhaled iloprost (n = 13) or bosentan (n = 18), and the effects on exercise capacity, haemodynamics and survival were evaluated. In the iloprost group, the survival rates at 1, 2 and 3 yrs were 77, 62 and 46%, respectively. In the bosentan group, the respective survival rates were 94, 89 and 89%. Event-free survival rates, i.e. survival without transplantation, right heart failure or clinical worsening requiring the introduction of a new treatment for pulmonary hypertension, was also significantly better in the bosentan group. Bosentan had significantly better effects than inhaled iloprost on exercise capacity, as determined by the 6-min walk test, as well as on haemodynamics. Both treatments proved to be safe, especially in regards of liver function. In the present series of patients with well-preserved liver function and severe portopulmonary hypertension, treatment with both inhaled iloprost and bosentan appeared to be safe. Patients treated with bosentan had higher survival rates, but prospective controlled studies are required to confirm these findings.

Potassium regulates IL-1 beta processing via calcium-independent phospholipase A2

We report that potassium leakage from cells leads to activation of the Ca2+-independent phospholipase A2 (iPLA2), and the latter plays a pivotal role in regulating the cleavage of pro-IL-1 beta by the IL-converting enzyme caspase-1 in human monocytes. K+ efflux led to increases of cellular levels of glycerophosphocholine, an unambiguous indicator of phospholipase A2 activation. Both maturation of IL-1 beta and formation of glycerophosphocholine were blocked by bromoenol lactone, the specific iPLA2 inhibitor. Bromoenol lactone-dependent inhibition of IL-1 beta processing was not due to perturbation of the export machinery for pro-IL-1 beta and IL-1 beta or to caspase-1 suppression. Conspicuously, activation of Ca2+-dependent phospholipase A2 did not support but rather suppressed IL-1 beta processing. Thus, our findings reveal a specific role for iPLA2 activation in the sequence of events underlying IL-1 beta maturation.

Factors influencing breath condensate volume

Analysis of breath condensate (BC) has received interest recently due to the need for easy and repetitive monitoring or airway and pulmonary disease. While many authors have used custom built systems, commercial systems are now available and will probably be used more widely. Early studies of markers and mediators in BC have reported concentrations following varying periods of sampling time. However, factors that influence the generation of BC have not been analysed and it is unclear whether breathing rate, tidal volume, lung function, body weight, height or age influence the amount of BC collected. We therefore studied the influence of these factors on breath condensate volume and breath condensate urea and protein concentrations in 22 healthy volunteers and 23 COPD patients. A strong correlation of total respired volume and breath condensate volume was observed for both groups (volunteers: r=0.952, p < 0.0001, COPD: r=0.883, p < 0.001) while no significant correlation existed for breath condensate volume and TLC, RV, Vc, FEV1, R(tot), height or body weight, As long as ventilation remained fairly constant, breath condensate volume increased linearly with time. The fraction of breath condensate extracted from total vapour contained in the exhalate was estimated by measuring relative atmospheric humidity before and after the collecting tube. The amount calculated by the change in temperature and saturation corresponded closely to the amount actually collected. We conclude from these results that breath condensate volume is primarily dependent on V(E), and does not seem to depend on lung function parameters. For standardisation it is suggested to report breath condensate measurements per volume respired. Both, urea and protein are present in measurable quantities in breath condensate and protein as well as BCV may be helpful denominators for comparison with e.g. cytokines in lung disease.

Co-morbid mental health conditions in cancer patients at working age--prevalence, risk profiles, and care uptake

OBJECTIVE

This study examined the prevalence of mental health conditions in cancer patients, the role of socioeconomic position in relation to that, and the use of professional mental health care.

METHODS

Prospective cohort with measurements at the beginning of inpatient treatment (baseline) and 3, 9, and 15 months after baseline using structured clinical interviews based on DSM-IV, questionnaires, and medical records.

RESULTS

At baseline, 149 out of 502 cancer patients (30%) were diagnosed with a mental health condition. Prevalence was associated with unemployment (odds ratio [OR] 2.0), fatigue (OR 1.9), and pain (OR 1.7). Of those with mental health conditions, 9% saw a psychotherapist within 3 months of the diagnosis, 19% after 9 months, and 11% after 15 months. Mental health care use was higher in patients with children ≤18 years (OR 3.3) and somatic co-morbidity (OR 2.6). There was no evidence for an effect of sex on the use of mental health care.

CONCLUSION

Few cancer patients with psychiatric disorders receive professional mental health care early enough. If patients are unemployed or if they suffer from fatigue or pain, special attention should be paid because the risk of having a mental health condition is increased in these patients.

Serum levels of vascular endothelial growth factor in patients with head and neck cancer

Angiogenesis is now considered to be crucial for tumor growth and metastasis. In several tumors, microvascular density has been shown to be correlated with metastasis and aggressiveness. Vascular endothelial growth factor (VEGF) is a secreted endothelial cell-specific mitogen, which is induced by hypoxia and is angiogenic in vivo. VEGF has been identified in a wide variety of malignancies including head and neck squamous cell carcinomas (HNSCC). We investigated the circulating level of VEGF in sera from patients with various head and neck squamous cell carcinomas (n = 71) as well as from healthy normal controls (n = 47). Serum VEGF concentrations were determined as serum immunoreactivity by using a quantitative sandwich enzyme immunoassay technique. For statistical analysis, the Wilcoxon 2-sample test and Kruskal-Wallis test were performed. The majority of the patients with HNSCC were found to have high concentrations of serum VEGE The levels of VEGF in the sera of patients with cancer ranged from below the detection limit to 937.1 pg/ml (mean, 144.5 pg/ml). In contrast, the VEGF serum levels in 47 healthy individuals ranged from below the detection limit to 168.1 pg/ml (mean, 32.7 pg/ml), VEGF serum concentration being significantly higher in HNSCC patients (P = < 0.001). These findings indicate that a positive angiogenesis regulator such as VEGF might function as an endocrine growth factor, particularly for solid HNSCC tumors and may be a useful marker for clinical monitoring.

Ventilation and secretion of pulmonary surfactant

Various factors are involved in the regulation of surfactant secretion: chemical agonist; local environmental factors such as mediators, locally produced hormones, and possibly pH; and finally, mechanical stress occurring during lung inflation. Here we suggest a model of regulation which is grouped into three levels: a basal autoregulatory mechanism with local factors being superimposed and a systemic level acting through hormones reaching the lung via the bloodstream. Depending on the situation, the different levels may vary in their importance. For the normal situation, in the absence of stress factors, we suggest the autoregulation of stretch-induced secretion and SP-A inhibition as indicated by in vitro experiments to be the prominent regulatory mechanism for surfactant secretion. From this model, mechanisms can be derived which indicate involvement of the surfactant system in, for example, obstructive lung disease. Support from the literature for this hypothesis is reviewed. Because quantitative measurement of the amount of surfactant-associated phospholipids cannot be done adequately at this time, we suggest testing the relatively risk-free application of exogenous surfactant in a pilot phase based on indications for its involvement and usefulness derived from animal and in vitro experiments.

Lipid analysis of bronchoalveolar lavage fluid (BAL) by MALDI-TOF mass spectrometry and 31P NMR spectroscopy

Despite the high clinical relevance, only the cellular moiety of bronchoalveolar lavage (BAL) has been intensively investigated and is used for diagnosis purposes. On the other hand, the cell-free fluid is, by far, less characterized. Although this fluid represents a relatively simple mixture of only a few different phospholipids (mainly phosphatidylcholine, phosphatidylglycerol and cholesterol), methods for the routine analysis of these fluids are still lacking. In the present investigation we have applied, for the first time, MALDI-TOF mass spectrometry, as well as 31P NMR spectroscopy to the analysis of organic extracts of bronchoalveolar lavage fluids. BAL from different mammals (rat, minipig, rabbit and man) were investigated and, for means of comparison, organic extracts of lung tissue were also examined. Both applied methods provide fast and reliable information on the lipid composition of the bronchoalveolar lavage. However, despite of its comparably low sensitivity, 31P NMR spectroscopy detects all phospholipid species in a single experiment and with the same sensitivity, whereas MALDI-TOF fails in the detection of phosphatidylethanolamine in the presence of higher quantities of phosphatidylcholine. In contrast, MALDI-TOF mass spectrometry is more suitable for the detection of cholesterol and the determination of the fatty acid composition of the individual phospholipids, especially lysolipids. It will be shown that all BALs exhibit significant, species-dependent differences that mainly concern the content of phosphatidylglycerol and lyso-phosphatidylcholine. It is concluded that both methods are suitable tools in lipid research due to the (in comparison to alternative methods) simplicity of performance.

[German guideline for diagnosis and management of idiopathic pulmonary fibrosis]

Idiopathic pulmonary fibrosis is a fatal lung disease with a variable and unpredictable natural history and limited treatment options. Since publication of the ATS-ERS statement on IPF in the year 2000 diagnostic standards have improved and a considerable number of randomized controlled treatment trials have been published necessitating a revision. In the years 2006 - 2010 an international panel of IPF experts produced an evidence-based guideline on diagnosis and treatment of IPF, which was published in 2011. In order to implement this evidence-based guideline into the German Health System a group of German IPF experts translated and commented the international guideline, also including new publications in the field. A consensus conference was held in Bochum on December 3rd 2011 under the protectorate of the "Deutsche Gesellschaft für Pneumologie und Beatmungsmedizin (DGP)" and supervised by the "Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften" (AWMF). Most recommendations of the international guideline were found to be appropriate for the german situation. Based on recent clinical studies "weak negative" treatment recommendations for pirfenidone and anticoagulation were changed into "weak positive" for pirfenidone and "strong negative" for anticoagulation. Based on negative results from the PANTHER-trial the recommendation for the combination therapy of prednisone plus azathiorpine plus N-acetlycsteine was also changed into strong negative für patients with definite IPF. This document summarizes essential parts of the international IPF guideline and the comments and recommendations of the German IPF consensus conference.

Cyclophosphamide pulse therapy in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive disorder with poor prognosis. Response to treatment is infrequent and the use of immunosuppressive agents other than corticosteroids is the subject of ongoing discussion because of uncertain efficacy and side-effects. To determine the efficacy and safety of cyclophosphamide pulse therapy in IPF, this study retrospectively analysed 18 patients with progressive IPF who were treated with intermittent i.v. cyclophosphamide (1-13 g x month(-1)) and additional oral prednisolone for 1 yr. Static lung volumes, arterial oxygen tension (Pa,O2) at rest, clinical symptoms and potential treatment-related side-effects were recorded. Cyclophosphamide had to be stopped in one patient, owing to repeated pulmonary infection; 11 patients were responders (five improving, six stabilizing) and six patients deteriorated. The change in vital capacity (VC) of responders was +6.7+/-18.0% (mean +/-SD), compared with -20.6+/-18.2% in nonresponders (p=0.008). Pa,O2 remained constant in responders (+0.13+/-0.88 kPa (+1.0+/-6.6 mmHg)), while it decreased in nonresponders (-2.08+/-1.92 kPa (-15.6+/-14.4 mmHg, p=0.008)). Additional prednisolone was reduced by 19.1+/-13.4 mg in responders, compared with 6.7+/-16.3 mg in nonresponders (p=0.02). VC at initiation of therapy was higher in responders (60.2+/-10.2 versus 40.3+/-12.9% predicted; p=0.004). No side-effects occurred, other than respiratory tract infection. These data demonstrate that intravenous cyclophosphamide pulse therapy may be a favourable regimen for certain patients with progressive idiopathic pulmonary fibrosis. Patients with a vital capacity of more than 50% predicted and a shorter duration of disease may benefit most.

Circulating endocannabinoids and N-acyl-ethanolamides in patients with sleep apnea--specific role of oleoylethanolamide

OBJECTIVE

The endocannabinoid system promotes diverse effects on fat and glucose metabolism as well as on energy balance and sleep regulation. The role of N-acylethanolamides like oleoylethanolamide (OEA) and other endocannabinoids such as anandamide (AEA) and 2-arachidonyl-glycerol (2-AG) has not yet been investigated in patients with sleep apnea.

DESIGN AND METHODS

We measured circulating OEA, AEA and 2-AG in patients with sleep apnea (n = 20) and healthy control subjects (n = 57). Respiratory distress index (RDI) as measured by polysomnography was used as a quantitative index of sleep apnea.

RESULTS

In patients with sleep apnea OEA serum concentrations were significantly higher than in control subjects (8.4 pmol/ml (95% CI 6.9;9.9) vs. 4.0 (3.5;4.5); p<0.0001, adjusted for body mass index (BMI), fasting insulin, HDL and LDL cholesterol). In contrast, AEA (2.9 (95% CI 1.9;3.9) vs. 1.8 (1.4;2.1), p = 0.09) and 2-AG (20.0 (-14.5;54.5) vs. 32.8 (21.4;44.2), p = 0.56) were not significantly different between patients with sleep apnea and control subjects after adjustment. In the sleep apnea group, OEA serum concentrations were associated with RDI (r (2) = 0.28, p = 0.02) and BMI (r (2) = 0.32, p = 0.01). However, OEA was not associated with BMI in the control group (p = 0.10).

CONCLUSIONS

These results indicate that among the three analyzed fatty acid derivatives, OEA plays a specific role in patients with sleep apnea. Together with animal data, the 2-fold elevation of OEA serum concentrations could be interpreted as a neuroprotective mechanism against chronic oxidative stressors and a mechanism to promote wakefulness in patients with nocturnal sleep deprivation and daytime hypersomnolence.

Factors associated with non-participation and dropout among cancer patients in a cluster-randomised controlled trial

We investigated the impact of demographic and disease related factors on non-participation and dropout in a cluster-randomised behavioural trial in cancer patients with measurements taken between hospitalisation and 6 months thereafter. The percentages of non-participation and dropout were documented at each time point. Factors considered to be potentially related with non-participation and dropout were as follows: age, sex, marital status, education, income, employment status, tumour site and stage of disease. Of 1,338 eligible patients, 24% declined participation at baseline. Non-participation was higher in older patients (Odds Ratio [OR] 2.1, CI: 0.6-0.9) and those with advanced disease (OR 2.0, CI: 0.1-1.3). Dropout by 6 months was 25%. Dropout was more frequent with increased age (OR 2.8, CI: 0.8-1.2), advanced disease (OR 3.0, CI: 1.0-1.2), being married (OR 2.4, CI 0.7-1.1) and less frequent with university education (OR 0.4, CI -1.3 to -0.8) and middle income (OR 0.4, CI -0.9 to -0.7). When planning clinical trials, it is important to be aware of patient groups at high risk of non-participation or dropout, for example older patients or those with advanced disease. Trial designs should consider their special needs to increase their rate of participation.

Local chemistry of the surfactant's head groups determines protein stability in reverse micelles

Protein stability in reverse micelles is determined by local chemical interactions between the surfactant molecules and the protein groups.

Breath-to-breath variability correlates with apnea-hypopnea index in obstructive sleep apnea

BACKGROUND

Breathing in patients with obstructive sleep apnea (OSA) is frequently interrupted by periods of hypopnea and apnea. There is limited information regarding a possible disturbance of breathing outside these periods.

STUDY OBJECTIVE

To analyze the degree of breathing disturbance during nonocclusion.

DESIGN

Prospective determination of breathing variability during full polysomnographic sleep studies.

PATIENTS

Breath-to-breath variation was monitored in 34 patients with OSA and in 9 healthy subjects.

MEASUREMENTS AND RESULTS

All breath-to-breath intervals were automatically analyzed from flow signal, displayed, and manually corrected for artifacts. Distribution of all nonapneic breath intervals was analyzed for the extent of difference from a normal distribution pattern by specifying kurtosis. In untreated OSA patients, kurtosis was significantly reduced (0.0 +/- 0.5, mean +/- SD) compared to control subjects (0.8 +/- 0.5), indicating increased variability of nonoccluded breathing. This effect was present in all sleep stages, and the extent depended significantly on the degree of disease. Continuous positive airway pressure breathing was able to normalize kurtosis (1.0 +/- 0.9) immediately.

CONCLUSIONS

Breathing in OSA is not only characterized by interruptions of breathing during occlusion, but by a greater variation in the pattern of normal-length breaths.

Hydrophobic Collapse of Ubiquitin Generates Rapid Protein-Water Motions

We report time-resolved measurements of the coupled protein-water modes of solvated ubiquitin during protein folding. Kinetic terahertz absorption (KITA) spectroscopy serves as a label-free technique for monitoring large scale conformational changes and folding of proteins subsequent to a sudden T-jump. We report here KITA measurements at an unprecedented time resolution of 500 ns, a resolution 2 orders of magnitude better than those of any previous KITA measurements, which reveal the coupled ubiquitin-solvent dynamics even in the initial phase of hydrophobic collapse. Complementary equilibrium experiments and molecular simulations of ubiquitin solutions are performed to clarify non-equilibrium contributions and reveal the molecular picture upon a change in structure, respectively. On the basis of our results, we propose that in the case of ubiquitin a rapid (<500 ns) initial phase of the hydrophobic collapse from the elongated protein to a molten globule structure precedes secondary structure formation. We find that these very first steps, including large-amplitude changes within the unfolded manifold, are accompanied by a rapid (<500 ns) pronounced change of the coupled protein-solvent response. The KITA response upon secondary structure formation exhibits an opposite sign, which indicates a distinct effect on the solvent-exposed surface.

Patientenfragebogen zur Erfassung der Ursachen interstitieller und seltener Lungenerkrankungen – klinische Sektion der DGP

Hintergrund Interstitielle Lungenerkrankungen (ILD) umfassen verschiedenste heterogene, zumeist chronische Erkrankungen des Interstitiums und/oder der Alveolen mit bekannten und unbekannten Ursachen. Die Diagnostik der ILD ist sehr komplex und sollte interdisziplinär erfolgen. Eine der wesentlichen Basisuntersuchungen ist eine umfangreiche Anamnese. Hierzu kam im deutschsprachigen Raum bisher der Frankfurter Bogen von 1985 zur Anwendung, der mittlerweile jedoch sprachlich und inhaltlich einer Überarbeitung bedurfte.

Methode Unter Schirmherrschaft der klinischen Sektion der DGP erfolgte die Erstellung eines neuen Patientenfragebogens zur Diagnostik interstitieller und seltener Lungenerkrankungen. Der Fragebogen entstand unter Mitarbeit von Pneumologen mit ILD-Expertise, Arbeitsmedizinern und Psychologen sowie der Unterstützung von Selbsthilfegruppen. Abschließend wurde der Fragebogen mithilfe von Patienten sprachlich optimiert.

Ergebnisse Der neu erstellte Patientenfragebogen zur Diagnostik interstitieller und seltener Lungenerkrankungen umfasst mehrere Bereiche: Initiale und aktuelle Symptome, Fragen zur Vorgeschichte inklusive Medikation, pulmonale und extrapulmonale Vorerkrankungen, mögliche Expositionen im häuslichen, privatem und beruflichem Umfeld sowie Familienanamnese und Reisetätigkeiten.

Schlussfolgerung Der neu erstellte Fragebogen kann in der klinischen Routine die Diagnostik bei Patienten mit Verdacht auf eine interstitielle Lungenerkrankung wesentlich erleichtern.

Proton Traffic Jam: Effect of Nanoconfinement and Acid Concentration on Proton Hopping Mechanism

The properties of the water network in concentrated HCl acid pools in nanometer-sized reverse non-ionic micelles were probed with TeraHertz absorption, dielectric relaxation spectroscopy, and reactive force field simulations capable of describing proton hopping mechanisms. We identify that only at a critical micelle size of W0=9 do solvated proton complexes form in the water pool, accompanied by a change in mechanism from Grotthuss forward shuttling to one that favors local oscillatory hopping. This is due to a preference for H+ and Cl- ions to adsorb to the micelle interface, together with an acid concentration effect that causes a "traffic jam" in which the short-circuiting of the hydrogen-bonding motif of the hydronium ion decreases the forward hopping rate throughout the water interior even as the micelle size increases. These findings have implications for atmospheric chemistry, biochemical and biophysical environments, and energy materials, as transport of protons vital to these processes can be suppressed due to confinement, aggregation, and/or concentration.

[Modern impulse oscillometry in the spectrum of pulmonary function testing methods]

Impulse oscillometry (IOS) is a computer supported method for the measurement of complex mechanical airway characteristics. Bronchial obstructions can reliably be diagnosed by IOS when more complex parameters such as frequency dependence of resistance (FDR) and lung reactance (X5) are evaluated in cases with more severe obstruction. Parameters of conventional methods like pneumotachography, spirometry, and bodyplethysmography show relatively low correlations due to the different measurement principles, not only in comparison to IOS, but also in between one another. The IOS is a convenient method for patients with a low dependency on cooperation for the evaluation of obstructive airway diseases complementary to the established standard methods. Furthermore, IOS may provide a sensitive screening tool for the early detection of bronchial obstructions not only in paediatrics but also in occupational medicine.

[Impulse oscillometry in the diagnosis of the severity of obstructive pulmonary disease]

Impulse oscillometry (IOS) is a computer-supported method for the measurement of complex mechanical airway characteristics. The aim of this study was to evaluate the applicability of IOS in the diagnosis of obstructive airway diseases in comparison to the standard methods of spirometry, pneumotachymetry, and bodyplethysmography. 244 patients (age 61.5 +/- 13.6 years; 61 % men) with bronchial asthma (n = 65) and chronic obstructive pulmonary disease (COPD) (n = 179) were retrospectively analysed. By means of body plethysmography (Srtot < 120%pred) an obstruction was diagnosed in 94%, by pneumotachymetry (FEV1 < 80%pred) in 78 %, and by IOS depending on the parameter chosen in 87-94% of patients. Mild and medium obstructions could be identified by means of all IOS parameters except for R20: severe obstructions, however, were better detected by means of the frequency-dependent resistance FDR and reactance at 5 Hz, X5. The parameters R5, X5, and Zrs, however, showed a tendency to underestimate the degree of obstruction. Bronchial obstruction can reliably be diagnosed by IOS when, in cases of severe obstruction, more complex parameters like FDR and X5 are included. The parameters of the standard methods (body plethysmography and pneumotachymetry) show relatively low correlations due to the different measurement methods not only in comparison to IOS but also to one another. In summary, IOS is a convenient method for patients with a low dependency on cooperation for the evaluation of obstructive airway diseases complementary to the established standard methods and, in addition, is useful as a sensitive screening tool for the early detection of bronchial obstruction.