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- Gouveia-Figueira, Sandra C., et al.
(författare)
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Mass spectrometry profiling reveals altered plasma levels of monohydroxy fatty acids and related lipids in healthy humans after controlled exposure to biodiesel exhaust
- 2018
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Ingår i: Analytica Chimica Acta. - : Elsevier. - 0003-2670 .- 1873-4324. ; 1018, s. 62-69
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Tidskriftsartikel (refereegranskat)abstract
- Experimental human exposure studies are an effective tool to study adverse health effects from acute inhalation of particulate matter and other constituents of air pollution. In this randomized and double-blinded crossover study, we investigated the systemic effect on bioactive lipid metabolite levels after controlled biodiesel exhaust exposure of healthy humans and compared it to filtered air at a separate exposure occasion. Eicosanoids and other oxylipins, as well as endocannabinoids and related lipids, were quantified in plasma from 14 healthy volunteers at baseline and at three subsequent time points (2, 6, and 24 h) after 1 h exposure sessions. Protocols based on liquid chromatography (LC) coupled to tandem mass spectrometry (MS/MS) methods were developed to detect temporal changes in circulating levels after biodiesel exhaust exposure. The exhaust was generated by a diesel engine fed with an undiluted rapeseed methyl ester fuel. Among the 51 analyzed lipid metabolites, PGF(2 alpha), 9,10-DiHOME, 9-HODE, 5-HETE, 11-HETE, 12-HETE, and DEA displayed significant responsiveness to the biodiesel exhaust exposure as opposed to filtered air. Of these, 9-HODE and 5-HETE at 24 h survived the 10% false discovery rate cutoff (p < 0.003). Hence, the majority of the responsive lipid metabolites were monohydroxy fatty acids. We conclude that it is possible to detect alterations in circulating bioactive lipid metabolites in response to biodiesel exhaust exposure using LC-MS/MS, with emphasis on metabolites with inflammation related properties and implications on cardiovascular health and disease. These observations aid future investigations on air pollution effects, especially with regard to cardiovascular outcomes.
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| 2. |
- Hansson, Alva, et al.
(författare)
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Reduced bronchoalveolar macrophage phagocytosis and cytotoxic effects after controlled short-term exposure to wood smoke in healthy humans
- 2023
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Ingår i: Particle and Fibre Toxicology. - : BioMed Central (BMC). - 1743-8977. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Exposure to wood smoke has been shown to contribute to adverse respiratory health effects including airway infections, but the underlying mechanisms are unclear. A preceding study failed to confirm any acute inflammation or cell influx in bronchial wash (BW) or bronchoalveolar lavage (BAL) 24 h after wood smoke exposure but showed unexpected reductions in leukocyte numbers. The present study was performed to investigate responses at an earlier phase, regarding potential development of acute inflammation, as well as indications of cytotoxicity.Methods: In a double-blind, randomised crossover study, 14 healthy participants were exposed for 2 h to filtered air and diluted wood smoke from incomplete wood log combustion in a common wood stove with a mean particulate matter concentration of 409 µg/m3. Bronchoscopy with BW and BAL was performed 6 h after exposure. Differential cell counts, assessment of DNA-damage and ex vivo analysis of phagocytic function of phagocytosing BAL cells were performed. Wood smoke particles were also collected for in vitro toxicological analyses using bronchial epithelial cells (BEAS-2B) and alveolar type II-like cells (A549).Results: Exposure to wood smoke increased BAL lactate dehydrogenase (LDH) (p = 0.04) and reduced the ex vivo alveolar macrophage phagocytic capacity (p = 0.03) and viability (p = 0.02) vs. filtered air. BAL eosinophil numbers were increased after wood smoke (p = 0.02), while other cell types were unaffected in BW and BAL. In vitro exposure to wood smoke particles confirmed increased DNA-damage, decreased metabolic activity and cell cycle disturbances.Conclusions: Exposure to wood smoke from incomplete combustion did not induce any acute airway inflammatory cell influx at 6 h, apart from eosinophils. However, there were indications of a cytotoxic reaction with increased LDH, reduced cell viability and impaired alveolar macrophage phagocytic capacity. These findings are in accordance with earlier bronchoscopy findings at 24 h and may provide evidence for the increased susceptibility to infections by biomass smoke exposure, reported in population-based studies.
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| 3. |
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| 4. |
- Larsson, B-M, et al.
(författare)
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Road tunnel air pollution induces bronchoalveolar inflammation in healthy subjects
- 2007
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Ingår i: European Respiratory Journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 29:4, s. 699-705
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Tidskriftsartikel (refereegranskat)abstract
- Traffic-related air pollution is associated with adverse respiratory effects. The aim of the present study was to investigate whether exposure to air pollution in a road tunnel causes airway inflammatory and blood coagulation responses. A total of 16 healthy subjects underwent bronchoscopy with bronchial mucosal biopsies and bronchoalveolar lavage (BAL) on two occasions, in random order: once at 14 h after a 2-h exposure to air pollution in a busy road tunnel, and once after a control day with subjects exposed to urban air during normal activities. Peripheral blood was sampled prior to bronchoscopy. The road tunnel exposures included particulate matter with a 50% cut-off aerodynamic diameter of 2.5 μm, particulate matter with a 50% cut-off aerodynamic diameter of 10 μm and nitrogen dioxide which had median concentrations of 64, 176 and 230 µg·m−3, respectively. Significantly higher numbers of BAL fluid total cell number, lymphocytes and alveolar macrophages were present after road tunnel exposure versus control. Significantly higher nuclear expression of the transcription factor component c-Jun was found in the bronchial epithelium after exposure. No upregulation of adhesion molecules or cellular infiltration was present and blood coagulation factors were unaffected. In conclusion, exposure of healthy subjects to traffic-related air pollution resulted in a lower airway inflammatory response with cell migration, together with signs of an initiated signal transduction in the bronchial epithelium.
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| 5. |
- Muala, Ala, et al.
(författare)
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Small airways effects of exposure to wood smoke
- 2019
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Ingår i: European Respiratory Journal. - Sheffield : European Respiratory Society Journals. - 0903-1936 .- 1399-3003. ; 54
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 6. |
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| 7. |
- Sehlstedt, Maria, 1979-, et al.
(författare)
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Airway inflammatory response to diesel exhaust generated at urban cycle running conditions
- 2010
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Ingår i: Inhalation Toxicology. - : Informa UK Limited. - 0895-8378 .- 1091-7691. ; 22:14, s. 1144-1150
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Tidskriftsartikel (refereegranskat)abstract
- DE generated under urban running conditions increased bronchial adhesion molecule expressions, together with the novel finding of bronchoalveolar eosinophilia, which has not been shown after exposure to DE at idling. Variations in airway inflammatory response to DE generated under diverse running condition may be related to differences in exhaust composition.
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| 8. |
- Sehlstedt, Maria, 1979-, et al.
(författare)
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Antioxidant airway responses following experimental exposure to wood smoke in man
- 2010
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Ingår i: Particle and Fibre Toxicology. - : Springer Science and Business Media LLC. - 1743-8977. ; 7, s. 21-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Biomass combustion contributes to the production of ambient particulate matter (PM) in rural environments as well as urban settings, but relatively little is known about the health effects of these emissions. The aim of this study was therefore to characterize airway responses in humans exposed to wood smoke PM under controlled conditions. Nineteen healthy volunteers were exposed to both wood smoke, at a particulate matter (PM2.5) concentration of 224 +/- 22 mu g/m(3), and filtered air for three hours with intermittent exercise. The wood smoke was generated employing an experimental set-up with an adjustable wood pellet boiler system under incomplete combustion. Symptoms, lung function, and exhaled NO were measured over exposures, with bronchoscopy performed 24 h post-exposure for characterisation of airway inflammatory and antioxidant responses in airway lavages. Results: Glutathione (GSH) concentrations were enhanced in bronchoalveolar lavage (BAL) after wood smoke exposure vs. air (p = 0.025), together with an increase in upper airway symptoms. Neither lung function, exhaled NO nor systemic nor airway inflammatory parameters in BAL and bronchial mucosal biopsies were significantly affected. Conclusions: Exposure of healthy subjects to wood smoke, derived from an experimental wood pellet boiler operating under incomplete combustion conditions with PM emissions dominated by organic matter, caused an increase in mucosal symptoms and GSH in the alveolar respiratory tract lining fluids but no acute airway inflammatory responses. We contend that this response reflects a mobilisation of GSH to the air-lung interface, consistent with a protective adaptation to the investigated wood smoke exposure.
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| 9. |
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| 10. |
- Sehlstedt, Maria, 1979-
(författare)
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Respiratory effects of particulate matter air pollution : studies on diesel exhaust, road tunnel, subway and wood smoke exposure in human subjects
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Ambient air pollution is associated with adverse health effects, but the sources and components, which cause these effects is still incompletely understood. The aim of this thesis was to investigate the pulmonary effects of a variety of common air pollutants, including diesel exhaust, biomass smoke, and road tunnel and subway station environments. Healthy non-smoking volunteers were exposed in random order to the specific air pollutants and air/control, during intermittent exercise, followed by bronchoscopy. Methods and results: In study I, exposures were performed with diesel exhaust (DE) generated at transient engine load and air for 1 hour with bronchoscopy at 6 hours post-exposure. Immunohistochemical analyses of bronchial mucosal biopsies showed that DE exposure significantly increased the endothelial adhesion molecule expression of p-selectin and VCAM-1, together with increased bronchoalveolar lavage (BAL) eosinophils. In study II, the subjects were exposed for 1 hour to DE generated during idling with bronchoscopy at 6 hours. The bronchial mucosal biopsies showed significant increases in neutrophils, mast cells and lymphocytes together with bronchial wash neutrophils. Additionally, DE exposure significantly increased the nuclear translocation of the aryl hydrocarbon receptor (AhR) and phosphorylated c-jun in the bronchial epithelium. In contrast, the phase II enzyme NAD(P)H-quinone oxidoreductase 1 (NQO1) decreased after DE. In study III, the 2-hour exposures took place in a road tunnel with bronchoscopy 14 hours later. The road tunnel exposure significantly increased the total numbers of lymphocytes and alveolar macrophages in BAL, whereas NK cell and CD56+/T cell numbers significantly decreased. Additionally, the nuclear expression of phosphorylated c-jun in the bronchial epithelium was significantly increased after road tunnel exposure. In study IV, the subjects were exposed to metal-rich particulate aerosol for 2 hours at a subway station with bronchial biopsy and BAL sampling at 14 hours. The subway exposure significantly increased the concentration of glutathione disulphide (GSSG) in BAL, with no airway inflammatory responses. In contrast, the number of neutrophils in the bronchial mucosa and the nuclear expression of phosphorylated c-jun in the bronchial epithelium tended to decrease after the subway exposure. In study V, the exposure to biomass smoke lasted 3 hours. Bronchoscopy was conducted 24 hours post exposure. The investigated biomass combustion emissions resulted in a significant increase in total glutathione and reduced glutathione in BAL, without any evident acute airway inflammatory responses. Conclusion: The present thesis presents data from exposures of healthy subjects to a variety of common air pollutants, as compared with an air reference. Oxidative as well as bronchial mucosal and bronchoalveolar responses differed between these air pollutants, with the most pronounced airway effects seen after exposure to diesel exhaust. This may be due to differences in pulmonary deposition, physicochemical characteristics, toxicological pathways and potency. Additional studies will assist in addressing dose-response and time kinetic aspects of the airway responses.
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