| 1. |
- Svensson, Sophie, 1970, et al.
(författare)
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Optimization and validation of an ion chromatographic method for the simultaneous determination of sodium, ammonium and potassium in exhaled breath condensate
- 2005
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Ingår i: J Chromatogr B Analyt Technol Biomed Life Sci. ; 814:1
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Tidskriftsartikel (refereegranskat)abstract
- An ion chromatographic method with conductivity detection for the simultaneous quantification of sodium, ammonium and potassium in exhaled breath condensate (EBC) was developed and validated. A factorial design was used to optimize the chromatographic conditions, which resulted in baseline separations of the cations within 6min. The method requires no pre-treatment of EBC samples. The optimized method was used for the intra-individual screening of cations in EBC of 10 healthy volunteers. The LOQs were low (0.3, 0.1 and 0.2muM for sodium, ammonium and potassium, respectively), compared with levels detected in healthy volunteers. The responses were linear with good precision, and samples could be stored for at least 10 weeks at refrigerating conditions.
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| 2. |
- Almstrand, Ann-Charlotte, et al.
(författare)
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Airway monitoring by collection and mass spectrometric analysis of exhaled particles.
- 2009
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Ingår i: Analytical chemistry. - : American Chemical Society (ACS). - 1520-6882 .- 0003-2700. ; 81:2, s. 662-8
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Tidskriftsartikel (refereegranskat)abstract
- We describe a new method for simultaneously collecting particles in exhaled air for subsequent chemical analysis and measuring their size distribution. After forced exhalation, particles were counted and collected in spots on silicon wafers with a cascade impactor. Several phospholipids were identified by time-of-flight secondary ion mass spectrometric analysis of the collected spots, suggesting that the particles originated from the lower airways. The amount of particles collected in ten exhalations was sufficient for characterizing the phospholipid composition. The feasibility of the technique in respiratory research is demonstrated by analysis of the phospholipid composition of exhaled particles from healthy controls, patients with asthma, and patients with cystic fibrosis. We believe this technology will be useful for monitoring patients with respiratory disease and has a high potential to detect new biomarkers in exhaled air.
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| 3. |
- Almstrand, Ann-Charlotte, et al.
(författare)
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An explorative study on respiratory health among operators working in polymer additive manufacturing
- 2023
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Ingår i: Frontiers in Public Health. - : Frontiers Media S.A.. - 2296-2565. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Additive manufacturing (AM), or 3D printing, is a growing industry involving a wide range of different techniques and materials. The potential toxicological effects of emissions produced in the process, involving both ultrafine particles and volatile organic compounds (VOCs), are unclear, and there are concerns regarding possible health implications among AM operators.The objective of this study was to screen the presence of respiratory health effects among people working with liquid, powdered, or filament plastic materials in AM. MethodsIn total, 18 subjects working with different additive manufacturing techniques and production of filament with polymer feedstock and 20 controls participated in the study. Study subjects filled out a questionnaire and underwent blood and urine sampling, spirometry, impulse oscillometry (IOS), exhaled NO test (FeNO), and collection of particles in exhaled air (PEx), and the exposure was assessed. Analysis of exhaled particles included lung surfactant components such as surfactant protein A (SP-A) and phosphatidylcholines. SP-A and albumin were determined using ELISA. Using reversed-phase liquid chromatography and targeted mass spectrometry, the relative abundance of 15 species of phosphatidylcholine (PC) was determined in exhaled particles. The results were evaluated by univariate and multivariate statistical analyses (principal component analysis). ResultsExposure and emission measurements in AM settings revealed a large variation in particle and VOC concentrations as well as the composition of VOCs, depending on the AM technique and feedstock. Levels of FeNO, IOS, and spirometry parameters were within clinical reference values for all AM operators. There was a difference in the relative abundance of saturated, notably dipalmitoylphosphatidylcholine (PC16:0_16:0), and unsaturated lung surfactant lipids in exhaled particles between controls and AM operators. ConclusionThere were no statistically significant differences between AM operators and controls for the different health examinations, which may be due to the low number of participants. However, the observed difference in the PC lipid profile in exhaled particles indicates a possible impact of the exposure and could be used as possible early biomarkers of adverse effects in the airways.
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| 4. |
- Almstrand, Ann-Charlotte
(författare)
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Analysis of Endogenous Particles in Exhaled Air
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Exhaled air contains non-volatile particulate material from the respiratory tract. The precise location in which exhaled particles are formed is unknown, and details on their chemical content are scarce. The aim of this work was to chemically characterize and to study the mechanisms of formation of endogenous particles in exhaled air. A new instrument for counting and sampling particles in exhaled air by impaction was developed, as a part of this thesis, at the Department of Public Health and Community Medicine, Occupational and Environmental Medicine in collaboration with the Department of Chemistry, Atmospheric Science at the University of Gothenburg. In the first instance, exhaled particles were analyzed using time-of-flight secondary ion mass spectrometry (TOF-SIMS), which is a very sensitive technique for surface analysis. This method was also used to compare the composition of particles in exhaled air from subjects with asthma to that in healthy controls. Second, a method for the quantitative determination of glutathione was developed and applied in the analysis of exhaled particles and exhaled breath condensate. In parallel to chemical analysis, the hypothesis that particles are formed during the reopening of closed airways was tested by measuring particle number concentrations in the air exhaled by healthy volunteers performing different breathing maneuvers. This is the first study involving chemical analysis of particles in exhaled air. TOF-SIMS analysis revealed that exhaled particles contain several phospholipids (phosphatidylcholine, phosphatidylglycerol and phosphatidylinositol). These lipids are characteristic of the pulmonary surfactant which is present in the respiratory tract lining fluid (RTLF) that covers the epithelium in the alveoli and the airways. Using this method, it was found that the TOF-SIMS spectra of the particles exhaled by healthy subjects differed from those of the particles exhaled by subjects with asthma. These differences were attributed to differences in the abundance of phosphatidylcholine and phosphatidylglycerol between the two groups. By using the newly-developed method for glutathione analysis, it was possible to demonstrate the presence of glutathione in exhaled particles for the first time. The method was used to compare glutathione levels in exhaled particles to those in exhaled breath condensate; it was found that analysis of particles was more revealing in terms of the levels of glutathione in exhaled air. Studies of particle formation showed that deep exhalations to residual volume (RV) caused significantly higher concentrations of particles in the subsequent exhalation than did exhalations to functional residual capacity (FRC).This supports the theory that film rupture during airway reopening after airway closure is an important mechanism of particle formation. The results of these studies show that particles in exhaled air can be sampled by impaction, that surfactant phospholipids and glutathione are part of their chemical composition, and that they are largely formed in the peripheral airways, where airway closure takes place.
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| 5. |
- Almstrand, Ann-Charlotte, et al.
(författare)
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Effect of Airway Opening on Production of Exhaled Particles.
- 2010
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Ingår i: Journal of applied physiology. - : American Physiological Society. - 1522-1601 .- 8750-7587. ; 108:3, s. 584-588
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Tidskriftsartikel (refereegranskat)abstract
- The technique of sampling exhaled air is attractive because it is non-invasive, and so allows repeated sampling with ease and no risk for the patient. Knowledge of the biomarkers' origin is important in order to correctly understand and interpret the data. Endogenous particles, formed in the airways, are exhaled and reflect chemical composition of the respiratory tract lining fluid. However, the formation mechanisms and formation sites of these particles are unknown. We hypothesize that airway opening following airway closure cause production of airborne particles that are exhaled. The objective of this study was to examine production of exhaled particles following varying degrees of airway closure. 10 healthy volunteers performed 3 different breathing manoeuvres in which the initial lung volume preceding an inspiration to total lung capacity was varied between functional residual capacity (FRC) and residual volume (RV). Exhaled particle number concentrations in the size interval 0.30-2.0 mum were recorded. Number concentrations of exhaled particles showed a 2-18 fold increase after exhalations to RV compared to exhalations where no airway closure was shown (8500 (810-28000) vs. 1300 (330-13000) particles/expired litre, p=0.012). The difference was most noticeable for the smaller size range of particles (<1 mum). There were significant correlations between particle concentrations for the different manoeuvres. Our results show that airway reopening following airway closure is an important mechanism for formation of endogenous exhaled particles and that these particles originate from the terminal bronchioles. Key words: exhaled particles, airway closure, breath.
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| 6. |
- Almstrand, Ann-Charlotte, et al.
(författare)
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Evidence for an N-methyl transfer reaction in phosphatidylcholines with a terminal aldehyde during negative electrospray ionization tandem mass spectrometry
- 2015
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 407:17, s. 5045-5052
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Tidskriftsartikel (refereegranskat)abstract
- Lipidomic analysis of the complex mixture of lipids isolated from biological systems can be a challenging process that often involves tandem mass spectrometry and interpretation of both precursor ions and product ions relative to the molecular structure of the lipids. Therefore, detailed understanding of the gas-phase ion chemistry occurring for each class of phospholipids is critically important for an accurate assignment of lipid structure. Some oxidized phosphatidylcholines are known to be biologically active and responsible for pathological events, and are therefore important targets for detection in lipidomic studies. Modification of fatty acyl chains by oxidation may, however, change the behavior of ion formation and decomposition in the mass spectrometer. In this study, we report on the mass-spectrometric behavior of 1-palmitoyl-2-(9'-oxononanoyl)-sn-glycero-3-phosphocholine, a bioactive product of phosphatidylcholine oxidation. In addition to [M-15](-) and the acetate adduct [M+59](-), three additional adduct ions, including [M-H](-), were present in significant abundance in the negative ion electrospray mass spectrum. It was found that this unexpected [M-H](-) ion was formed by the transfer of a methyl group from the choline residue on the polar head group to the aldehyde functionality of the sn-2 substituent, resulting in a 14-Da increase in the mass of the resulting sn-2 carboxylate anion formed by collisional activation of this ion. These results suggest additional rules for understanding the gas-phase ion chemistry of aldehydic phosphatidylcholine molecular species.
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| 7. |
- Almstrand, Ann-Charlotte, et al.
(författare)
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Identification of oxidized phospholipids in bronchoalveolar lavage exposed to low ozone levels using multivariate analysis
- 2015
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Ingår i: Analytical Biochemistry. - : Elsevier BV. - 0003-2697 .- 1096-0309. ; 474, s. 50-58
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Tidskriftsartikel (refereegranskat)abstract
- Chemical reactions with unsaturated phospholipids in the respiratory tract lining fluid have been identified as one of the first important steps in the mechanisms mediating environmental ozone toxicity. As a consequence of these reactions, complex mixtures of oxidized lipids are generated in the presence of mixtures of non-oxidized naturally occurring phospholipid molecular species, which challenge methods of analysis. Untargeted mass spectrometry and statistical methods were employed to approach these complex spectra. Human bronchoalveolar lavage (BAL) was exposed to low levels of ozone, and samples with and without derivatization of aldehydes were analyzed by liquid chromatography electrospray ionization tandem mass spectrometry. Data processing was carried out using principal component analysis (PCA). Resulting PCA scores plots indicated an ozone dose-dependent increase, with apparent separation between BAL samples exposed to 60 ppb ozone and non-exposed BAL samples as well as a clear separation between ozonized samples before and after derivatization. Corresponding loadings plots revealed that more than 30 phosphatidylcholine (PC) species decreased due to ozonation. A total of 13 PC and 6 phosphatidylglycerol oxidation products were identified, with the majority being structurally characterized as chain-shortened aldehyde products. This method exemplifies an approach for comprehensive detection of low-abundance, yet important, components in complex lipid samples.
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| 8. |
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| 9. |
- Almstrand, Ann-Charlotte, et al.
(författare)
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TOF-SIMS analysis of exhaled particles from patients with asthma and healthy controls.
- 2012
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Ingår i: The European respiratory journal: official journal of the European Society for Clinical Respiratory Physiology. - : European Respiratory Society (ERS). - 1399-3003 .- 0903-1936. ; 39:1, s. 59-66
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Tidskriftsartikel (refereegranskat)abstract
- Particles in exhaled air (PEx) may reflect the composition of respiratory tract lining fluid (RTLF); thus, there is a need to assess their potential as sources of biomarkers for respiratory diseases. In the present study, we compared PEx from patients with asthma and controls using time-of-flight-secondary ion mass spectrometry (TOF-SIMS) and multivariate analysis. Particles were collected using an instrument developed in-house. 15 nonsmoking subjects with physician-diagnosed asthma and 11 nonsmoking healthy controls performed 10 consecutive forced exhalations into the instrument. Particle concentrations were recorded and samples of particles collected on silicon plates were analysed by TOF-SIMS. Subjects with asthma exhaled significantly lower numbers of particles than controls (p=0.03) and the ratio of unsaturated to saturated phospholipids was significantly lower in samples from subjects with asthma (0.25 versus 0.35; p=0.036). Orthogonal partial least squares-discriminant analysis models showed good separation between both positive and negative spectra. Molecular ions from phosphatidylcholine and phosphatidylglycerol, and protein fragments were found to discriminate the groups. We conclude that analysis of PEx is a promising method to examine the composition of RTLF. In the present explorative study, we could discriminate between subjects with asthma and healthy controls based on TOF-SIMS spectra from PEx.
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| 10. |
- Assenhöj, Maria, et al.
(författare)
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Occupational exposure and health surveys at metal additive manufacturing facilities
- 2023
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Ingår i: Frontiers in Public Health. - : FRONTIERS MEDIA SA. - 2296-2565. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Additive manufacturing is a novel state-of-the art technology with significant economic and practical advantages, including the ability to produce complex structures on demand while reducing the need of stocking materials and products. Additive manufacturing is a technology that is here to stay; however, new technologies bring new challenges, not only technical but also from an occupational health and safety perspective. Herein, leading Swedish companies using metal additive manufacturing were studied with the aim of investigating occupational exposure and the utility of chosen exposure- and clinical markers as predictors of potential exposure-related health risks.Methods: Exposure levels were investigated by analysis of airborne dust and metals, alongside particle counting instruments measuring airborne particles in the range of 10 nm-10 mu m to identify dusty work tasks. Health examinations were performed on a total of 48 additive manufacturing workers and 39 controls. All participants completed a questionnaire, underwent spirometry, and blood and urine sampling. A subset underwent further lung function tests.Results: Exposure to inhalable dust and metals were low, but particle counting instruments identified specific work tasks with high particle emissions. Examined health parameters were well within reference values on a group level. However, statistical analysis implied an impact on workers kidney function and possible airway inflammation.Conclusion: The methodology was successful for investigating exposure-related health risks in additive manufacturing. However, most participants have been working <5 years. Therefore, long-term studies are needed before we can conclusively accept or reject the observed effects on health.
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| 11. |
- Barregård, Lars, 1948, et al.
(författare)
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Experimental exposure to wood smoke: effects on airway inflammation and oxidative stress.
- 2008
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Ingår i: Occupational and environmental medicine. - : BMJ. - 1470-7926 .- 1351-0711. ; 65:5, s. 319-24
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Particulate air pollution affects cardiovascular and pulmonary disease and mortality. A main hypothesis about the mechanisms involved is that particles induce inflammation in lower airways, systemic inflammation and oxidative stress. OBJECTIVES: To examine whether short-term exposure to wood smoke in healthy subjects affects markers of pulmonary inflammation and oxidative stress. METHODS: 13 subjects were exposed first to clean air and then to wood smoke in a chamber during 4-hour sessions, 1 week apart. The mass concentrations of fine particles at wood smoke exposure were 240-280 mug/m(3), and number concentrations were 95 000-180 000/cm(3), about half of the particles being ultrafine (<100 nm). Blood and breath samples were taken before and at various intervals after exposure to wood smoke and clean air and examined for exhaled nitric oxide and Clara cell protein in serum and urine, and malondialdehyde in exhaled breath condensate. RESULTS: Exposure to wood smoke increased alveolar nitric oxide 3 hours post-exposure while malondialdehyde levels in breath condensate were higher both immediately after and 20 hours after exposure. Serum Clara cell protein was increased 20 hours after exposure. CONCLUSIONS: Wood smoke at levels that can be found in smoky indoor environments caused an inflammatory response and signs of increased oxidative stress in the respiratory tract, especially in the lower airways.
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| 12. |
- Bredberg, Anna, et al.
(författare)
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Comparison of Exhaled Endogenous Particles from Smokers and Non-Smokers Using Multivariate Analysis
- 2013
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Ingår i: Respiration. - : S. Karger AG. - 0025-7931 .- 1423-0356. ; 86:2, s. 135-142
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Tidskriftsartikel (refereegranskat)abstract
- Background: Smoking, along with many respiratory diseases, has been shown to induce airway inflammation and alter the composition of the respiratory tract lining fluid (RTLF). We have previously shown that the phospholipid and protein composition of particles in exhaled air (PEx) reflects that of RTLF. In this study, we hypothesized that the composition of PEx differs between smokers and non-smokers, reflecting inflammation in the airways. Objective: It was the aim of this study to identify differences in the phospholipid composition of PEx from smokers and non-smokers. Methods: PEx from 12 smokers and 13 non-smokers was collected using a system developed in-house. PEx was analysed using time-of-flight secondary ion mass spectrometry, and the mass spectral data were evaluated using multivariate analysis. Orthogonal partial least squares (OPLS) was used to relate smoking status, lung function and pack years to the chemical composition of RTLF. The discriminating ions identified by OPLS were then used as explanatory variables in traditional regression analysis. Results: There was a clear discrimination between smokers and non-smokers according to the chemical composition, where phospholipids from smokers were protonated and sodiated to a larger extent. Poor lung function showed a strong association with higher response from all molecular phosphatidylcholine species in the samples. Furthermore, the accumulated amount of tobacco consumed was associated with variations in mass spectra, indicating a dose-response relationship. Conclusion: The chemical composition of PEx differs between smokers and nonsmokers, reflecting differences in the RTLF. The results from this study may suggest that the composition of RTLF is affected by smoking and may be of importance for lung function.
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| 13. |
- Bredberg, Anna, et al.
(författare)
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Exhaled Endogenous Particles Contain Lung Proteins.
- 2012
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Ingår i: Clinical Chemistry. - : Oxford University Press (OUP). - 1530-8561 .- 0009-9147. ; 58:2, s. 431-440
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:We recently developed a novel, noninvasive method for sampling nonvolatile material from the distal airways. The method is based on the collection of endogenous particles in exhaled air (PEx). The aim of this study was to characterize the protein composition of PEx and to verify that the origin of PEx is respiratory tract lining fluid (RTLF).METHOD:Healthy individuals exhaled into the sampling device, which collected PEx onto a silicon plate inside a 3-stage impactor. After their extraction from the plates, PEx proteins were separated by SDS-PAGE and then analyzed by LC-MS. Proteins were identified by searching the International Protein Index human database with the Mascot search engine.RESULTS:Analysis of the pooled samples identified 124 proteins. A comparison of the identified PEx proteins with published bronchoalveolar lavage (BAL) proteomic data showed a high degree of overlap, with 103 (83%) of the PEx proteins having previously been detected in BAL. The relative abundances of the proteins were estimated according to the Mascot exponentially modified protein abundance index protocol and were in agreement with the expected protein composition of RTLF. No amylase was detected, indicating the absence of saliva protein contamination with our sampling technique.CONCLUSIONS:Our data strongly support that PEx originate from RTLF and reflect the composition of undiluted RTLF.
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| 14. |
- Ericson, Petrea, 1966, et al.
(författare)
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Low Levels of Exhaled Surfactant Protein A Associated With BOS After Lung Transplantation
- 2016
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Ingår i: Transplantation Direct. - : Ovid Technologies (Wolters Kluwer Health). - 2373-8731. ; 2:9
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Tidskriftsartikel (refereegranskat)abstract
- Background. There is no clinically available marker for early detection or monitoring of chronic rejection in the form of bronchiolitis obliterans syndrome (BOS), the main long-term complication after lung transplantation. Sampling and analysis of particles in exhaled air is a valid, noninvasive method for monitoring surfactant protein A (SP-A) and albumin in the distal airways. Methods. We asked whether differences in composition of exhaled particles can be detected when comparing stable lung transplant recipients (LTRs) (n = 26) with LTRs who develop BOS (n = 7). A comparison between LTRs and a matching group of healthy controls (n = 33) was also conducted. Using a system developed in-house, particles were collected from exhaled air by the principal of inertial impaction before chemical analysis by immunoassays. Results. Surfactant protein A in exhaled particles and the SP-A/albumin ratio were lower (P = 0.002 and P = 0.0001 respectively) in the BOS group compared to the BOS-free group. LTRs exhaled higher amount of particles (P < 0.0001) and had lower albumin content (P < 0.0001) than healthy controls. Conclusions. We conclude that low levels of SP-A in exhaled particles are associated with increased risk of BOS in LTRs. The possibility that this noninvasive method can be used to predict BOS onset deserves further study with prospective and longitudinal approaches.
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| 15. |
- Holmgren, Helene, 1981, et al.
(författare)
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Effects of breath holding at low and high lung volumes on amount of exhaled particles
- 2013
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Ingår i: Respiratory Physiology & Neurobiology. - : Elsevier BV. - 1569-9048 .- 1878-1519. ; 185:2, s. 228-234
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Tidskriftsartikel (refereegranskat)abstract
- Exhaled breath contains particles originating from the respiratory tract lining fluid. The particles are thought to be generated during inhalation, by reopening of airways closed in the preceding expiration. The aim here was to explore processes that control exhaled particle concentrations. The results show that 5 and 10 s breath holding at residual volume increased the median concentration of particles in exhaled air by 63% and 110%, respectively, averaged over 10 subjects. An increasing number of closed airways, developing on a timescale of seconds explains this behaviour. Breath holds of 5, 10 and 20 s at total lung capacity decreased the concentration to 63%, 45% and 28% respectively, of the directly exhaled concentration. The decrease in particle concentration after breath holding at total lung capacity is caused by gravitational settling in the alveoli and associated bronchioles. The geometry employed here when modelling the deposition is however not satisfactory and ways of improving the description are discussed.
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| 16. |
- Holmgren, Helene, 1981, et al.
(författare)
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Size Distribution of Exhaled Particles in the Range from 0.01 to 2.0 µm
- 2010
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Ingår i: Journal of Aerosol Science. - : Elsevier BV. - 0021-8502 .- 1879-1964. ; 41:5, s. 439-446
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates the number size distribution of endogenously produced exhaled particles during tidal breathing and breathing with airway closure. This is the first time that the region below 0.4 µm has been investigated. The particle concentration was generally lower for tidal breathing than for airway closure, although the inter-individual variation was large. During tidal breathing, the size distribution peaks at around 0.07 µm. This peak is still present during the airway closure manoeuvre, but an additional broad and strong peak is found between 0.2 and 0.5 µm. This suggests that different mechanisms govern the generation of particles in the two cases. The particles produced from airway closure may be attributed to formation of film droplets in the distal bronchioles during inhalation. It is speculated that the very small particles are film droplets originating from the alveolar region.
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| 17. |
- Larsson, Per, et al.
(författare)
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Exhaled particles as markers of small airway inflammation in subjects with asthma
- 2017
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Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961. ; 37:5, s. 489-497
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Tidskriftsartikel (refereegranskat)abstract
- Exhaled breath contains suspended particles of respiratory tract lining fluid from the small airways. The particles are formed when closed airways open during inhalation. We have developed a method called Particles in Exhaled air (PExA((R))) to measure and sample these particles in the exhaled aerosol. Here, we use the PExA((R)) method to study the effects of birch pollen exposure on the small airways of individuals with asthma and birch pollen allergy. We hypothesized that birch pollen-induced inflammation could change the concentrations of surfactant protein A and albumin in the respiratory tract lining fluid of the small airways and influence the amount of exhaled particles. The amount of exhaled particles was reduced after birch pollen exposure in subjects with asthma and birch pollen allergy, but no significant effect on the concentrations of surfactant protein A and albumin in exhaled particles was found. The reduction in the number of exhaled particles may be due to inflammation in the small airways, which would reduce their diameter and potentially reduce the number of small airways that open and close during inhalation and exhalation.
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| 18. |
- Larsson, Per, et al.
(författare)
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Surfactant protein A and albumin in particles in exhaled air.
- 2012
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Ingår i: Respiratory medicine. - : Elsevier BV. - 1532-3064 .- 0954-6111. ; 106:2, s. 197-204
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Tidskriftsartikel (refereegranskat)abstract
- In this study we test the hypothesis that endogenous particles in exhaled air (PEx), non-invasively sampled from lower airways, are well suited for the analysis of respiratory tract lining fluid (RTLF) proteins, i.e., surfactant protein A (SP-A) and albumin. Ten healthy volunteers were included in the study and participated in two sampling sessions. Blood, exhaled breath condensate (EBC) and PEx were collected at each session. 100L of breath were collected for each exhaled sample. Serum and exhaled samples were analyzed for SP-A using an in-house ELISA. Albumin was analyzed in exhaled samples using a commercial ELISA kit. SP-A detection rates were 100%, 21%, and 89% for PEx, EBC and serum, respectively. Albumin was detected in PEx, but not in EBC. SP-A measurements in PEx showed good repeatability with an intra-individual coefficient of variation of 13%. Both SP-A and albumin showed significant correlation to mass of PEx (r(s)=0.93, p<0.001 and r(s)=0.86, p=0.003, respectively). Sampling and analysis of PEx is a valid non-invasive method to monitor RTLF proteins sampled from the lower respiratory tract, as demonstrated here by example of SP-A and albumin analysis.
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| 19. |
- Larsson, Per, et al.
(författare)
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The effect of exhalation flow on endogenous particle emission and phospholipid composition
- 2017
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Ingår i: Respiratory Physiology & Neurobiology. - : Elsevier BV. - 1569-9048. ; 243, s. 39-46
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Tidskriftsartikel (refereegranskat)abstract
- Exhaled particles constitute a micro-sample of respiratory tract lining fluid. Inhalations from low lung volumes generate particles in small airways by the airway re-opening mechanism. Forced exhalations are assumed to generate particles in central airways by mechanisms associated with high air velocities. To increase knowledge on how and where particles are formed, different breathing manoeuvres were compared in 11 healthy volunteers. Particles in the 0.41-4.55 mu m diameter range were characterised and sampled. The surfactant lipid dipalmitoylphosphatidylcholine (DPPC) was quantified by mass spectrometry. The mass of exhaled particles increased by 150% (95% CI 10-470) for the forced exhalation and by 470% (95% CI 150-1190) for the airway re-opening manoeuvre, compared to slow exhalations. DPPC weight percent concentration (wt%) in particles was 2.8 wt% (95%CI 1.4-4.2) and 9.4 wt% (95%CI 8.0-10.8) for the forced and the airway re-opening manoeuvres, respectively. In conclusion, forced exhalation and airway re-opening manoeuvres generate particles from different airway regions having different DPPC concentration.
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| 20. |
- Ljungkvist, Göran, 1949, et al.
(författare)
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Two techniques to sample non-volatiles in breath-exemplified by methadone.
- 2018
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Ingår i: Journal of breath research. - : IOP Publishing. - 1752-7163. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- The particles in exhaled breath provide a promising matrix for the monitoring of pathological processes in the airways, and also allow exposure to exogenous compounds to be to assessed. The collection is easy to perform and is non-invasive. The aim of the present study is to assess if an exogenous compound-methadone-is distributed in the lining fluid of small airways, and to compare two methods for collecting methadone in particles in exhaled breath. Exhaled particles were collected from 13 subjects receiving methadone maintenance treatment. Two different sampling methods were applied: one based on electret filtration, potentially collecting exhaled particles of all sizes, and one based on impaction, collecting particles in the size range of 0.5-7 μm, known to reflect the respiratory tract lining fluid from the small airways. The collected samples were analyzed by liquid chromatography mass spectrometry, and the impact of different breathing patterns was also investigated. The potential contribution from the oral cavity was investigated by rinsing the mouth with a codeine solution, followed by codeine analysis of the collected exhaled particles by both sampling methods. The results showed that methadone was present in all samples using both methods, but when using the method based on impaction, the concentration of methadone in exhaled breath was less than 1% of the concentration collected by the method based on filtration. Optimizing the breathing pattern to retrieve particles from small airways did not increase the amount of exhaled methadone collected by the filtration method. The contamination from codeine present in the oral cavity was only detected in samples collected by the impaction method. We conclude that methadone is distributed in the respiratory tract lining fluid of small airways. The samples collected by the filtration method most likely contained a contribution from the upper airways/oral fluid in contrast to the impaction method.
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| 21. |
- Lärstad, Mona, 1971, et al.
(författare)
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Surfactant Protein A in Exhaled Endogenous Particles Is Decreased in Chronic Obstructive Pulmonary Disease (COPD) Patients: A Pilot Study
- 2015
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 10:12
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Tidskriftsartikel (refereegranskat)abstract
- Background Exhaled, endogenous particles are formed from the epithelial lining fluid in small airways, where surfactant protein A (SP-A) plays an important role in pulmonary host defense. Based on the knowledge that chronic obstructive pulmonary disease (COPD) starts in the small airway epithelium, we hypothesized that chronic inflammation modulates peripheral exhaled particle SP-A and albumin levels. The main objective of this explorative study was to compare the SP-A and albumin contents in exhaled particles from patients with COPD and healthy subjects and to determine exhaled particle number concentrations. Patients with stable COPD ranging from moderate to very severe (n = 13), and healthy nonsmoking subjects (n = 12) were studied. Subjects performed repeated breath maneuvers allowing for airway closure and re-opening, and exhaled particles were optically counted and collected on a membrane using the novel PExA1 instrument setup. Immunoassays were used to quantify SP-A and albumin. COPD patients exhibited significantly lower SP-A mass content of the exhaled particles (2.7 vs. 3.9 weight percent, p = 0.036) and lower particle number concentration (p<0.0001) than healthy subjects. Albumin mass contents were similar for both groups. Decreased levels of SP-A may lead to impaired host defense functions of surfactant in the airways, contributing to increased susceptibility to COPD exacerbations. SP-A in exhaled particles from small airways may represent a promising non-invasive biomarker of disease in COPD patients.
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| 22. |
- Murgia, Nicola, et al.
(författare)
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8-ISOPROSTANE IN EXHALED BREATH CONDENSATE AFTER EXPERIMENTAL EXPOSURE TO WOOD SMOKE IN HUMANS
- 2016
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Ingår i: Journal of Biological Regulators and Homeostatic Agents. - 0393-974X. ; 30:1, s. 263-270
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Tidskriftsartikel (refereegranskat)abstract
- Wood smoke, a well-known indoor and outdoor air pollutant, may cause adverse health effects through oxidative stress. In this study 8-isoprostane, a biomarker of oxidative stress, was measured in exhaled breath condensate (EBC) and urine before and after experimental exposure to wood smoke. The results were compared with measurements of other biomarkers of oxidative stress and inflammation. Thirteen subjects were exposed first to clean air and then, after 1 week, to wood smoke in an exposure chamber during 4-hour sessions. Exhaled breath condensate, exhaled nitric oxide, blood and urine were sampled before and at various intervals after exposure to wood smoke and clean air. Exhaled breath condensate was examined for 8-isoprostane and malondialdehyde (MDA), while exhaled air was examined for nitric oxide, serum for Clara cell protein (CC16) and urine for 8-isoprostane. 8-isoprostane in EBC did not increase after wood smoke exposure and its net change immediately after exposure was inversely correlated with net changes in MDA (r(s)= -0.57, p= 0.041) and serum CC16 (S-CC16) (r(p)= -0.64, p= 0.020) immediately after the exposure. No correlation was found between 8-isoprostane in urine and 8-isoprostane in EBC. In this study controlled wood smoke exposure in healthy subjects did not increase 8-isoprostane in EBC.
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| 23. |
- Romieu, Isabelle, et al.
(författare)
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Exhaled breath malondialdehyde as a marker of effect of exposure to air pollution in children with asthma.
- 2008
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Ingår i: The Journal of allergy and clinical immunology. - : Elsevier BV. - 1097-6825 .- 0091-6749. ; 121:4
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Assessment of the adverse effects of oxidative stress related to air pollution is limited by the lack of biological markers of dose to the lungs. OBJECTIVE: We evaluated the use of exhaled breath condensate (EBC) malondialdehyde as a biomarker of exposure to traffic-related pollution in children with asthma as part of a panel study in Mexico City. METHODS: Standard spirometry and collection of EBC and nasal lavage were performed. Environmental monitoring sites were located within 5 km of the children's homes and schools. Data were analyzed by using generalized estimating equations. RESULTS: A total of 480 samples of malondialdehyde were obtained from 107 patients with asthma, with a median level of 18.7 (interquartile range [IQR], 12.4-28.7) nmol. Ambient particulates less than 2.5 microg/m(3) and ozone levels on the day of sampling were significantly associated with higher malondialdehyde levels. A 14.2-microg/m(3) (IQR) increase in 8-hour moving average particulates less than 2.5 microg/m(3) in size was associated with a 1.12-nmol increase in malondialdehyde and a 15.9-ppb (IQR) increase in 8-hour moving average ozone with a 1.16-nmol increase in malondialdehyde. Malondialdehyde levels were inversely associated with forced vital capacity and FEV(1) and positively associated with IL-8 levels in nasal lavage. CONCLUSION: Exhaled breath condensate malondialdehyde was related to both air pollution exposure and changes in lung function and inflammatory markers.
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| 24. |
- Runström Eden, Gunilla, et al.
(författare)
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Exploring Methods for Surveillance of Occupational Exposure from Additive Manufacturing in Four Different Industrial Facilities
- 2022
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Ingår i: Annals of Work Exposures and Health. - : Oxford University Press (OUP). - 2398-7308 .- 2398-7316. ; 66:2, s. 163-177
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Tidskriftsartikel (refereegranskat)abstract
- 3D printing, a type of additive manufacturing (AM), is a rapidly expanding field. Some adverse health effects have been associated with exposure to printing emissions, which makes occupational exposure studies important. There is a lack of exposure studies, particularly from printing methods other than material extrusion (ME). The presented study aimed to evaluate measurement methods for exposure assessment in AM environments and to measure exposure and emissions from four different printing methods [powder bed fusion (PBF), material extrusion (ME), material jetting (MJ), and vat photopolymerization] in industry. Structured exposure diaries and volatile organic compound (VOC) sensors were used over a 5-day working week. Personal and stationary VOC samples and real-time particle measurements were taken for 1 day per facility. Personal inhalable and respirable dust samples were taken during PBF and MJ AM. The use of structured exposure diaries in combination with measurement data revealed that comparatively little time is spent on actual printing and the main exposure comes from post-processing tasks. VOC and particle instruments that log for a longer period are a useful tool as they facilitate the identification of work tasks with high emissions, highlight the importance of ventilation and give a more gathered view of variations in exposure. No alarming levels of VOCs or dust were detected during print nor post-processing in these facilities as adequate preventive measures were installed. As there are a few studies reporting negative health effects, it is still important to keep the exposure as low as reasonable.
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| 25. |
- Runström Eden, Gunilla, et al.
(författare)
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Particle and VOC Emissions During the Thermal Processing of Plastics to make Filaments for 3D-Printing
- 2023
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Ingår i: Annals of Work Exposures and Health. - : Oxford University Press. - 2398-7308 .- 2398-7316. ; 67:Supplement_1
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Tidskriftsartikel (refereegranskat)abstract
- Introduction 3D-printing is continuing to grow as an industry, which creates a demand for printing material. Studies on 3D-printing have shown that printers emit nanoparticles and VOC, depending on printing method, and some adverse health effects have been reported. Emissions during production of 3D-printer filament is less studied, and interesting as it can be likened to a larger material extrusion printer. Materials and methods Measurements were made at a factory producing 3D-printer filaments, using an array of instruments to characterise the emissions and exposure for the staff. Particle emissions were assessed using condensation particle counters (20nm-1um), DataRAM (0.1-10 um) and a particle sensor (0.35-40 um). VOC emissions and exposure were assessed using Tenax tubes and VOC sensors. Measurements were performed for 1-2 days, apart from sensors, which were placed at the facility for a full working week, including after a longer break . Results High concentrations of nanoparticles were found in the production rooms (25 000-100 000 pt/ml) and close to the extruder nozzle (100 000-500 000 pt/ml). Levels of nanoparticles were also high in office rooms near production(25 000-50 000 pt/ml). VOC sensors showed the same trend in all rooms, including offices and staff kitchen, indicating spread of emissions from the source and inadequate ventilation. The particle sensor also showed variation over the week in correlation with work performed. Conclusion Production of 3D-printer filaments emit nanoparticles and VOC. Inadequate ventilation can lead to high concentrations of nanoparticles. Sensors were a useful tool to show emission trends.
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| 26. |
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| 27. |
- Stockfelt, Leo, 1981, et al.
(författare)
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Effects on airways of short-term exposure to two kinds of wood smoke in a chamber study of healthy humans.
- 2012
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Ingår i: Inhalation toxicology. - : Informa UK Limited. - 1091-7691 .- 0895-8378. ; 24:1, s. 47-59
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Air pollution causes respiratory symptoms and pulmonary disease. Airway inflammation may be involved in the mechanism also for cardiovascular disease. Wood smoke is a significant contributor to air pollution, with complex and varying composition. We examined airway effects of two kinds of wood smoke in a chamber study. Materials and Methods: Thirteen subjects were exposed to filtered air and to wood smoke from the start-up phase and the burn-out phase of the wood-burning cycle. Levels of PM(2.5) were 295 µg/m(3) and 146 µg/m(3), number concentrations 140 000/cm(3) and 100 000/cm(3). Biomarkers in blood, breath and urine were measured before and on several occasions after exposure. Effects of wood smoke exposure were assessed adjusting for results with filtered air. Results: After exposure to wood smoke from the start-up, but not the burn-out session, Clara cell protein 16 (CC16) increased in serum after 4 hours, and in urine the next morning. CC16 showed a clear diurnal variation. Fraction of exhaled nitric oxide (FENO) increased after wood smoke exposure from the burn-out phase, but partly due to a decrease after exposure to filtered air. No other airway markers increased. Conclusions: The results indicate that relatively low levels of wood smoke exposure induce effects on airways. Effects on airway epithelial permeability was shown for the start-up phase of wood burning, while FENO increased after the burn-out session. CC16 seems to be a sensitive marker of effects of air pollution both in serum and urine, but its function and the significance need to be clarified.
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