| 1. |
- Högman, Marieann, et al.
(författare)
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Effects of growth and aging on the reference values of pulmonary nitric oxide dynamics in healthy subjects
- 2017
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Ingår i: Journal of Breath Research. - : IOP Publishing. - 1752-7155 .- 1752-7163. ; 11:4
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Tidskriftsartikel (refereegranskat)abstract
- The lung just like all other organs is affected by age. The lung matures by the age of 20 and age-related changes start around middle age, at 40-50 years. Exhaled nitric oxide (FENO) has been shown to be age, height and gender dependent. We hypothesize that the nitric oxide (NO) parameters alveolar NO (CANO), airway flux (JawNO), airway diffusing capacity (DawNO) and airway wall content (CawNO) will also demonstrate this dependence. Data from healthy subjects were gathered by the current authors from their earlier publications in which healthy individuals were included as control subjects. Healthy subjects (n = 433) ranged in age from 7 to 78 years. Age-stratified reference values of the NO parameters were significantly different. Gender differences were only observed in the 20-49 age group. The results from the multiple regression models in subjects older than 20 years revealed that age, height and gender interaction together explained 6% of variation in FENO at 50 ml s-1 (FENO50), 4% in JawNO, 16% in CawNO, 8% in DawNO and 12% in CANO. In conclusion, in this study we have generated reference values for NO parameters from an extended NO analysis of healthy subjects. This is important in order to be able to use these parameters in clinical practice.
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| 2. |
- Ghorbani, Ramin, 1981-, et al.
(författare)
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Fitting of single-exhalation profiles using a pulmonary gas exchange model : application to carbon monoxide
- 2019
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Ingår i: Journal of Breath Research. - : Institute of Physics Publishing (IOPP). - 1752-7155 .- 1752-7163. ; 13:2
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Tidskriftsartikel (refereegranskat)abstract
- Real-time breath gas analysis coupled to gas exchange modeling is emerging as promising strategy to enhance the information gained from breath tests. It is shown for exhaled breath carbon monoxide (eCO), a potential biomarker for oxidative stress and respiratory diseases, that a weighted, nonlinear least-squares fit of simulated to measured expirograms can be used to extract physiological parameters, such as airway and alveolar concentrations and diffusing capacities. Experimental CO exhalation profiles are acquired with high time-resolution and precision using mid-infrared tunable diode laser absorption spectroscopy and online breath sampling. A trumpet model with axial diffusion is employed to generate eCO profiles based on measured exhalation flow rates and volumes. The concept is demonstrated on two healthy non-smokers exhaling at a flow rate of 250 ml s−1 during normal breathing and at 120 ml s−1 after 10 s of breath-holding. The obtained gas exchange parameters of the two subjects are in a similar range, but clearly distinguishable. Over a series of twenty consecutive expirograms, the intra-individual variation in the alveolar parameters is less than 6%. After a 2 h exposure to 10 ± 2 ppm CO, end-tidal and alveolar CO concentrations are significantly increased (by factors of 2.7 and 4.9 for the two subjects) and the airway CO concentration is slightly higher, while the alveolar diffusing capacity is unchanged compared to before exposure. Using model simulations, it is found that a three-fold increase in maximum airway CO flux and a reduction in alveolar diffusing capacity by 60% lead to clearly distinguishable changes in the exhalation profile shape. This suggests that extended breath CO analysis has clinical relevance in assessing airway inflammation and chronic obstructive pulmonary disease. Moreover, the novel methodology contributes to the standardization of real-time breath gas analysis.
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| 3. |
- Högman, Marieann
(författare)
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Innovative exhaled breath analysis with old breathing manoeuvres-is there a problem or an advantage?
- 2017
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Ingår i: Journal of Breath Research. - : IOP Publishing. - 1752-7155 .- 1752-7163. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- As the field of exhaled breath research is expanding, the question that arises is can the old usual method of spirometry be used in all cases? The answer is yes for some analysation methods and definitely not for others: it all depends on the result you are looking for. Exhaled breath condensate collection can be accomplished with silent tidal breathing, but not in the analysation of the amount of exhaled particles, as they become very low during tidal breathing. There are gases that are exhalation flow dependent, e.g. nitric oxide, acetone and ethanol, that require a special breathing manoeuvre with flow control. Physiological changes of the lung, i.e. inhalation to total lung capacity or forced exhalation such as during spirometry, will affect the result of exhaled biomarkers. The standardisation of exhaled breath requires further development, and there are many aspects to consider.
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| 4. |
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| 5. |
- Jacinto, Tiago, et al.
(författare)
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Differential effect of cigarette smoke exposure on exhaled nitric oxide and blood eosinophils in healthy and asthmatic individuals
- 2017
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Ingår i: Journal of Breath Research. - : IOP Publishing. - 1752-7155 .- 1752-7163. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- Background:Tobacco smoking affects both the fraction of exhaled nitric oxide (FeNO) and blood eosinophil (B-Eos) count, two clinically useful biomarkers in respiratory disease that represent local and systemic type-2 inflammation, respectively.Objective:We aimed to study the influence of objectively measured smoke exposure on FeNO and B-Eos in a large population of subjects with and without asthma.Methods:We utilized the US National Health and Nutrition Examination Surveys 2007-2012 and included 10 669 subjects aged 6-80 years: 9869 controls and 800 asthmatics. Controls were defined as having no respiratory disease, no hay fever in the past year, and B-Eos count ≤0.3 × 109 l−1. Asthma was defined as self-reported current asthma and at least one episode of wheezing or an asthma attack in the past year, but no emphysema or chronic bronchitis. Tobacco use was collected via questionnaires and serum cotinine was measured with mass spectrometry.Results:Increasing cotinine levels were associated with a progressive reduction in FeNO in both controls and asthmatics. FeNO remained significantly higher in asthmatics than controls except in the highest cotinine decile, equivalent to an average reported consumption of 13 cigarettes/day. B-Eos count increased with cotinine in controls, but was unchanging in asthmatics. Interestingly, B-Eos count was significantly higher in presently non-exposed (cotinine below detection limit) former smokers than never smokers.Conclusion:Smoke exposure decreases FeNO and increases B-Eos count. These effects should be considered in the development of normalized values and their interpretation in clinical practice. The persistence of elevated B-Eos in former smokers warrants further studies.
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| 6. |
- Krantz, Christina, et al.
(författare)
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Exhaled and nasal nitric oxide in relation to lung function, blood cell counts and disease characteristics in cystic fibrosis
- 2017
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Ingår i: Journal of Breath Research. - : IOP Publishing. - 1752-7155 .- 1752-7163. ; 11:2
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Patients with cystic fibrosis (CF) have similar or lower exhaled nitric oxide (FeNO) and lower nasal nitric oxide (nNO) levels than controls. There are divergent results on alveolar NO (CalvNO) concentrations in relation to CF. There are inconsistent results on correlation between different nitric oxide parameters and lung function and inflammation in CF.AIM: To compare FeNO, CalvNO and nNO levels between subjects with CF, asthma and healthy controls and to study whether these parameters are related to lung function, blood cell counts or clinical characteristics in CF patients.MATERIAL AND METHODS: Measurements of FeNO at multiple exhalation flow rates, nNO and spirometry were done in 38 patients (18 adults) with CF. Blood cell counts and CF clinical characteristics were recorded. Thirty-eight healthy controls and 38 asthma patients, gender- and age-matched, were included as reference groups.RESULTS: FeNO levels were lower in CF patients (7.2 [4.7-11.2] ppb) than in healthy controls (11.4 [8.3-14.6] ppb) and asthma patients (14.7 [8.7-24.7] ppb) (both p < 0.005). These differences were consistent in adults. No difference in CalvNO was seen between the groups. nNO levels in CF patients (319 [193-447] ppb) were lower than in healthy controls (797 [664-984] ppb) and asthma patients (780 [619-961] ppb) (both p < 0.001). FeNO positively related to FEV1 (rho = 0.51, p = 0.001) in CF patients and this was consistent in both adults and children. A negative correlation was found between FeNO and blood neutrophil counts (rho = -0.37, p = 0.03) in CF patients.CONCLUSION: CF patients have lower FeNO and nNO and similar CalvNO levels as healthy controls and asthma patients. Lower FeNO related to lower lung function in both adults and children with CF. Furthermore, in CF, lower FeNO also related to higher blood neutrophil counts.
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| 7. |
- Perez-Bogerd, Silvia, et al.
(författare)
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COPD patients with peripheral airway obstruction reversibility identified by exhaled nitric oxide
- 2019
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Ingår i: Journal of Breath Research. - : IOP Publishing. - 1752-7155 .- 1752-7163. ; 13:3
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Tidskriftsartikel (refereegranskat)abstract
- Rationale:Besides its role as an inflammatory marker in asthma, fractional exhaled nitric oxide (FENO) provides information on the extent of the airway obstruction process through evaluating its change after bronchodilation.Objective:To investigate whether FENO change after bronchodilation can identify different sites of airway obstruction in COPD patients.Methods:FENO, FEV(1 )and the slopes (S) of the alveolar plateau of the single breath washout test (SBWT) were measured in 61 stable COPD patients (FEV1 34.5% predicted) before and after the inhalation of 400 mu g salbutamol. SBWT used Helium (He), and sulfur-hexafluoride (SF6). Obstruction relief occurring in pre-acinar and intra-acinar small airways is expected to decrease S-He and S-F6 , respectively. Indices changes (Delta) after bronchodilation were expressed as a percentage of pre-bronchodilation values.Results:FENO stability (vertical bar Delta FENO vertical bar <= 11%) was observed in 19 patients [-2.7(6.7)%] [mean (SD)] (NO = group); Delta FENO > 11% [+37.4(27.7)%] in 20 patients (NO+group) and Delta FENO < -11% in 22 patients [-31.2(9.8)%] (NO- group). A similar Delta FEV1 (p = 0.583; [+9.4(9.6)%]) was found in the three groups. In NO = and NO+ groups, neither S-He nor S-SF6 changed; in NO- both S-He [-12.4(27.5)%, p = 0.007] and S-SF6 [ -20.2(20.4)%, p < 0.001] significantly decreased.Conclusion:Different patterns of FENO response to beta(2) -agonists were observed in COPD most likely depending on the extent of the dilation process. A profile of airway obstruction with an extensive beta(2) -agonist response down to lung periphery is identified by FENO reduction after acute bronchodilation in 30% of COPD patients. The clinical relevance of this profile requires further investigation.
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| 8. |
- Soares, M., et al.
(författare)
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Particles in exhaled air (PExA): non-invasive phenotyping of small airways disease in adult asthma
- 2018
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Ingår i: Journal of Breath Research. - : IOP Publishing. - 1752-7155 .- 1752-7163. ; 12:4
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Tidskriftsartikel (refereegranskat)abstract
- Rationale: Asthma is often characterised by inflammation, damage and dysfunction of the small airways, but no standardised biomarkers are available. Objectives: Using a novel approach-particles in exhaled air (PExA)-we sought to (a) sample and analyse abundant protein biomarkers: surfactant protein A (SPA) and albumin in adult asthmatic and healthy patients and (b) relate protein concentrations with physiological markers using phenotyping. Methods: 83 adult asthmatics and 21 healthy volunteers were recruited from a discovery cohort in Leicester, UK, and 32 adult asthmatics as replication cohort from Sweden. Markers of airways closure/small airways dysfunction were evaluated using forced vital capacity, impulse oscillometry and multiple breath washout. SPA/albumin from PEx (PExA sample) were analysed using ELISA and corrected for acquired particle mass. Topological data analysis (TDA) was applied to small airway physiology and PExA protein data to identify phenotypes. Results: PExA manoeuvres were feasible, including severe asthmatic subjects. TDA identified a clinically important phenotype of asthmatic patients with multiple physiological markers of peripheral airway dysfunction, and significantly lower levels of both SPA and albumin. Conclusion: We report that the PExA method is feasible across the spectrum of asthma severity and could be used to identify small airway disease phenotypes.
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| 9. |
- Jacinto, Tiago, et al.
(författare)
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Evolution of exhaled nitric oxide levels throughout development and aging of healthy humans
- 2015
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Ingår i: Journal of Breath Research. - : IOP Publishing. - 1752-7155 .- 1752-7163. ; 9:3
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Tidskriftsartikel (refereegranskat)abstract
- It is not fully understood how the fraction of exhaled nitric oxide (FeNO) varies with age and gender in healthy individuals. We aim to describe the evolution of FeNO with age, giving special regard to the effect of gender, and to relate this evolution to natural changes in the respiratory tract. We studied 3081 subjects from NHANES 2007-08 and 2009-10, aged 6-80 years, with no self-reported diagnosis of asthma, chronic bronchitis or emphysema, and with normal values of blood eosinophils and C-reactive protein. The relationship of the mean values of FeNO to age, in all participants and divided by gender, was computed, and compared with changes in anatomic dead space volume and forced vital capacity. A change-point analysis technique and subsequent piecewise regression was used to detect breakpoints in the evolution of FeNO with age. Three distinct phases in the evolution of FeNO throughout the age range 6-80 years can be seen. FeNO values increase linearly between 6-14 years of age in girls and between 6-16 years of age in boys, in parallel with somatic growth. After that, FeNO levels plateau in both genders until age 45 years in females and age 59 years in males, when they start to increase linearly again. This increase continues until age 80. Our data clearly show a triphasic evolution of FeNO throughout the human age range in healthy individuals. This should be accounted for in development of reference equations for normal FeNO values.
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| 10. |
- Thorhallsdottir, Anna Kristin, et al.
(författare)
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Exhaled nitric oxide in a middle-aged Icelandic population cohort.
- 2016
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Ingår i: Journal of Breath Research. - : IOP Publishing. - 1752-7155 .- 1752-7163. ; 10:4
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Tidskriftsartikel (refereegranskat)abstract
- The prevalence of atopy and asthma is relatively low in Iceland. The purpose of this study was to describe exhaled nitric oxide (FeNO) levels in the general population in correlation with demographic characteristics, smoking status, asthma, rhinitis, atopic status and lung function tests. Altogether 403 subjects, from the European Community Respiratory Health Survey (ECRHS) III who answered the main questionnaire and were checked by FeNO measurements, lung function testing, skin prick testing and measurement of total IgE and specific IgE were included. The geometric mean (95% CI) of FeNO was 16.2 ppb (15.2-17.1) and the prevalence of higher FeNO (⩾25 ppb) was 19.5% in the random sample. Subjects with higher FeNO levels were less likely to be current smokers and more likely to have asthma and rhinitis. Having higher FeNO values was also associated with higher total IgE, having specific IgE to at least one allergen and being skin prick test positive. Current smokers had significantly lower levels of FeNO, geometric mean (95% CI) 9.6 ppb (8.4-11.0), than ex-smokers 18.2 ppb (16.6-20.0) and never smokers 17.3 ppb (16.1-18.5). In multivariable models, having asthma (OR (95% CI) 2.10 (1.20-3.67)), having a specific IgE (OR 2.30 (1.25-4.23)) and being skin prick test positive (OR 2.06 (1.18-3.60)) were independently positively associated with a higher FeNO (⩾25) whereas current smoking was independently negatively associated with a higher FeNO (OR 0.19 (0.06-0.63)). Higher levels of FeNO (⩾25 ppb) were found in one out of five Icelanders; FeNO was positively associated with asthma and allergy and negatively with smoking.
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