Isoprostanes-Biomarkers of Lipid Peroxidation: Their Utility in Evaluating Oxidative Stress and Analysis

Isoprostanes (IsoPs) are key biomarkers for investigating the role of free radical generation in the pathogenesis of human disorders. To solve IsoPs-related problems with regard to isoprostanes, analytical tools are required. This paper reviews the problems and trends in this field focusing on the methodology for assaying biomarkers in exhaled breath condensate (EBC) samples. A large amount of work has been done in the qualitative and quantitative analysis of IsoPs, but a standardized method has yet to emerge. The methodologies described differ, either in the sample preparation steps or in the detection techniques, or both. Requiring a number of chromatographic steps, the relevant extraction and purification procedures are often critical and time-consuming, and they lead to a substantial loss of target compounds. Recent data show that EBC is a promising non-invasive tool for the evaluation of different diseases. Two main analytical approaches have been adopted for IsoPs measurement: immunological methods and mass spectrometry. The methodologies for the extraction, purification and analysis of IsoPs in EBC samples are presented

Short-term intra-subject variation in exhaled volatile organic compounds (VOCs) in COPD patients and healthy controls and its effect on disease classification

Exhaled volatile organic compounds (VOCs) are of interest for their potential to diagnose disease non-invasively. However, most breath VOC studies have analyzed single breath samples from an individual and assumed them to be wholly consistent representative of the person. This provided the motivation for an investigation of the variability of breath profiles when three breath samples are taken over a short time period (two minute intervals between samples) for 118 stable patients with Chronic Obstructive Pulmonary Disease (COPD) and 63 healthy controls and analyzed by gas chromatography and mass spectroscopy (GC/MS). The extent of the variation in VOC levels differed between COPD and healthy subjects and the patterns of variation differed for isoprene versus the bulk of other VOCs. In addition, machine learning approaches were applied to the breath data to establish whether these samples differed in their ability to discriminate COPD from healthy states and whether aggregation of multiple samples, into single data sets, could offer improved discrimination. The three breath samples gave similar classification accuracy to one another when evaluated separately (66.5% to 68.3% subjects classified correctly depending on the breath repetition used). Combining multiple breath samples into single data sets gave better discrimination (73.4% subjects classified correctly). Although accuracy is not sufficient for COPD diagnosis in a clinical setting, enhanced sampling and analysis may improve accuracy further. Variability in samples, and short-term effects of practice or exertion, need to be considered in any breath testing program to improve reliability and optimize discrimination

Bronchoalveolar lavage, sputum and exhaled clinically relevant inflammatory markers: values in healthy adults.

11noBronchoalveolar lavage (BAL), induced sputum and exhaled breath markers (exhaled nitric oxide and exhaled breath condensate) can each provide biological insights into the pathogenesis of respiratory disorders. Some of their biomarkers are also employed in the clinical management of patients with various respiratory diseases. In the clinical context, however, defining normal values and cut-off points is crucial. The aim of the present review is to investigate to what extent the issue of defining normal values in healthy adults has been pursued for the biomarkers with clinical value. The current authors reviewed data from literature that specifically addressed the issue of normal values from healthy adults for the four methodologies. Most studies have been performed for BAL (n = 9), sputum (n = 3) and nitric oxide (n = 3). There are no published studies for breath condensate, none of whose markers yet has clinical value. In healthy adult nonsmokers the cut-off points (mean+2sd) for biomarkers with clinical value were as follows. BAL: 16.7% lymphocytes, 2.3% neutrophils and 1.9% eosinophils; sputum: 7.7 x 10(6).mL(-1) total cell count and 2.2% eosinophils; nitric oxide: 20.2 ppb. The methodologies differ concerning the quantity and characteristics of available reference data. Studies focusing on obtaining reference values from healthy individuals are still required, more evidently for the new, noninvasive methodologies.nonemixedBALBI B; PIGNATTI P; CORRADI M; BAIARDI P; BIANCHI L; BRUNETTI G; RADAELI A; MOSCATO G; MUTTI A; SPANEVELLO A; MALERBA MBalbi, B; Pignatti, P; Corradi, M; Baiardi, P; Bianchi, L; Brunetti, G; Radaeli, A; Moscato, G; Mutti, A; Spanevello, Antonio; Malerba, M

Expiratory flow rate, breath hold and anatomic dead space influence electronic nose ability to detect lung cancer

BACKGROUND: Electronic noses are composites of nanosensor arrays. Numerous studies showed their potential to detect lung cancer from breath samples by analysing exhaled volatile compound pattern ("breathprint"). Expiratory flow rate, breath hold and inclusion of anatomic dead space may influence the exhaled levels of some volatile compounds; however it has not been fully addressed how these factors affect electronic nose data. Therefore, the aim of the study was to investigate these effects. METHODS: 37 healthy subjects (44 +/- 14 years) and 27 patients with lung cancer (60 +/- 10 years) participated in the study. After deep inhalation through a volatile organic compound filter, subjects exhaled at two different flow rates (50 ml/sec and 75 ml/sec) into Teflon-coated bags. The effect of breath hold was analysed after 10 seconds of deep inhalation. We also studied the effect of anatomic dead space by excluding this fraction and comparing alveolar air to mixed (alveolar + anatomic dead space) air samples. Exhaled air samples were processed with Cyranose 320 electronic nose. RESULTS: Expiratory flow rate, breath hold and the inclusion of anatomic dead space significantly altered "breathprints" in healthy individuals (p 0.05). These factors also influenced the discrimination ability of the electronic nose to detect lung cancer significantly. CONCLUSIONS: We have shown that expiratory flow, breath hold and dead space influence exhaled volatile compound pattern assessed with electronic nose. These findings suggest critical methodological recommendations to standardise sample collections for electronic nose measurements

Short-term health effects of air pollution and viral exposure

This thesis describes the short-term effects of environmental exposures on the cardiorespiratory system, and consists of two parts. In the first part, we investigated the short-term health effects of air pollution, in which 21 healthy young adults were repeatedly (2-5 visits) exposed for 5 hours to the ambient air near a major airport and two highways. We found that exposures to high levels of ultrafine particles, decreased lung function, prolonged the QTc interval, altered the exhaled breath profile, and heightened concentrations of oxidative stress markers in urine. This study shows the importance of air pollution reduction and the need for future research to determine how detrimental the (long-term) effects of exposure to ultrafine particles (from aviation) are. In the second part, we investigated the effects of a rhinovirus challenge on the fluctuations in exhaled metabolites. Exhaled breath measurements were performed 2-3 times per week using an electronic nose, 60 days before and 30 days after a rhinovirus-16 (RV16) challenge, in non-atopic healthy adults (n=12) and atopic mild asthmatics (n=12). We found that day-to-day fluctuations in the exhaled breath profiles rapidly increased after the RV16 challenge, with distinct differences between atopic mild asthmatics and non-atopic healthy volunteers. This proof-of-concept study shows the potential of exhaled breath analysis for monitoring of virus-induced exacerbations in asthma