| 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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