| 1. |
- Behndig, Annelie, et al.
(författare)
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Airway antioxidant and inflammatory responses to diesel exhaust exposure in healthy humans.
- 2006
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Ingår i: European Respiratory Journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 27:2, s. 359-365
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Tidskriftsartikel (refereegranskat)abstract
- Pulmonary cells exposed to diesel exhaust (DE) particles in vitro respond in a hierarchical fashion with protective antioxidant responses predominating at low doses and inflammation and injury only occurring at higher concentrations. In the present study, the authors examined whether similar responses occurred in vivo, specifically whether antioxidants were upregulated following a low-dose DE challenge and investigated how these responses related to the development of airway inflammation at different levels of the respiratory tract where particle dose varies markedly. A total of 15 volunteers were exposed to DE (100 microg x m(-3) airborne particulate matter with a diameter of <10 microm for 2 h) and air in a double-blinded, randomised fashion. At 18 h post-exposure, bronchoscopy was performed with lavage and mucosal biopsies taken to assess airway redox and inflammatory status. Following DE exposure, the current authors observed an increase in bronchial mucosa neutrophil and mast cell numbers, as well as increased neutrophil numbers, interleukin-8 and myeloperoxidase concentrations in bronchial lavage. No inflammatory responses were seen in the alveolar compartment, but both reduced glutathione and urate concentrations were increased following diesel exposure. In conclusion, the lung inflammatory response to diesel exhaust is compartmentalised, related to differing antioxidant responses in the conducting airway and alveolar regions.
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| 2. |
- Behndig, Annelie F., et al.
(författare)
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Effects of controlled diesel exhaust exposure on apoptosis and proliferation markers in bronchial epithelium : an in vivo bronchoscopy study on asthmatics, rhinitics and healthy subjects
- 2015
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Ingår i: BMC Pulmonary Medicine. - : Springer Science and Business Media LLC. - 1471-2466. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Background: Epidemiological evidence demonstrates that exposure to traffic-derived pollution worsens respiratory symptoms in asthmatics, but controlled human exposure studies have failed to provide a mechanism for this effect. Here we investigated whether diesel exhaust (DE) would induce apoptosis or proliferation in the bronchial epithelium in vivo and thus contribute to respiratory symptoms.Methods: Moderate (n = 16) and mild (n = 16) asthmatics, atopic non-asthmatic controls (rhinitics) (n = 13) and healthy controls (n = 21) were exposed to filtered air or DE (100 μg/m 3 ) for 2 h, on two separate occasions. Bronchial biopsies were taken 18 h post-exposure and immunohistochemically analysed for pro-apoptotic and anti-apoptotic proteins (Bad, Bak, p85 PARP, Fas, Bcl-2) and a marker of proliferation (Ki67). Positive staining was assessed within the epithelium using computerized image analysis.Results: No evidence of epithelial apoptosis or proliferation was observed in healthy, allergic or asthmatic airways following DE challenge.Conclusion: In the present study, we investigated whether DE exposure would affect markers of proliferation and apoptosis in the bronchial epithelium of asthmatics, rhinitics and healthy controls, providing a mechanistic basis for the reported increased airway sensitivity in asthmatics to air pollutants. In this first in vivo exposure investigation, we found no evidence of diesel exhaust-induced effects on these processes in the subject groups investigated.
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| 3. |
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| 4. |
- Bosson, Jenny, et al.
(författare)
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Ozone-induced bronchial epithelial cytokine expression differs between healthy and asthmatic subjects
- 2003
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Ingår i: Clinical and Experimental Allergy. - : Wiley. - 0954-7894 .- 1365-2222. ; 33:6, s. 777-782
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Tidskriftsartikel (refereegranskat)abstract
- Background Ozone (O3) is a common air pollutant associated with adverse health effects. Asthmatics have been suggested to be a particularly sensitive group. Objective This study evaluated whether bronchial epithelial cytokine expression would differ between healthy and allergic asthmatics after ozone exposure, representing an explanatory model for differences in susceptibility. Methods Healthy and mild allergic asthmatic subjects (using only inhaled β2-agonists prn) were exposed for 2 h in blinded and randomized sequence to 0.2 ppm of O3 and filtered air. Bronchoscopy with bronchial mucosal biopsies was performed 6 h after exposure. Biopsies were embedded in GMA and stained with mAbs for epithelial expression of IL-4, IL-5, IL-6, IL-8, IL-10, TNF-α, GRO-α, granulocyte–macrophage colony-stimulating factor (GM–CSF), fractalkine and ENA-78. Results When comparing the two groups at baseline, the asthmatic subjects showed a significantly higher expression of IL-4 and IL-5. After O3 exposure the epithelial expression of IL-5, GM–CSF, ENA-78 and IL-8 increased significantly in asthmatics, as compared to healthy subjects. Conclusion The present study confirms a difference in epithelial cytokine expression between mild atopic asthmatics and healthy controls, as well as a differential epithelial cytokine response to O3. This O3-induced upregulation of T helper type 2 (Th2)-related cytokines and neutrophil chemoattractants shown in the asthmatic group may contribute to a subsequent worsening of the airway inflammation, and help to explain their differential sensitivity to O3 pollution episodes.
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| 5. |
- Eklund, Linda, et al.
(författare)
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An experimental exposure study revealing composite airway effects of physical exercise in a subzero environment
- 2021
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Ingår i: International Journal of Circumpolar Health. - : Taylor & Francis. - 1239-9736 .- 2242-3982. ; 80:1
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Tidskriftsartikel (refereegranskat)abstract
- Exposure to a cold climate is associated with an increased morbidity and mortality, but the specific mechanisms are largely unknown. People with cardiopulmonary disease and winter endurance athletes are particularly vulnerable. This study aimed to map multiple domains of airway responses to exercise in subzero temperature in healthy individuals.Thirty-one healthy subjects underwent whole-body exposures for 50 minutes on two occasions in an environmental chamber with intermittent moderate-intensity exercise in +10 °C and -10 °C. Lung function, plasma/urine CC16 , and symptoms were investigated before and after exposures.Compared to baseline, exercise in -10 °C decreased FEV1 (p=0.002), FEV1/FVC (p<0.001), and increased R20Hz (p=0.016), with no differences between exposures. Reactance increased after +10 °C (p=0.005), which differed (p=0.042) from a blunted response after exercise in -10 °C. Plasma CC16 increased significantly within exposures, without differences between exposures. Exercise in -10 °C elicited more intense symptoms from the upper airways, compared to +10 °C. Symptoms from the lower airways were few and mild. Short-duration moderate-intensity exercise in -10 °C induces mild symptoms from the lower airways, no lung function decrements or enhanced leakage of biomarkers of airway epithelial injury, and no peripheral bronchodilatation, compared to exercise in +10 °C.
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| 6. |
- Eklund, Linda, 1982-
(författare)
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Cold air, physical activity, and the airways : epidemiological and experimental studies
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Cold exposure is associated with increased morbidity and mortality. Elite cross-country skiers are regularly exposed to cold, dry air and have a high prevalence of asthma compared to the Swedish population. However, evidence is limited regarding how a combination of sub-zero temperatures and physical activity affects the airways of healthy individuals.Aims: The aims of this thesis were to study the prevalence of self-reported asthma, age at asthma onset, and predictors of asthma in Swedish endurance athletes, with a focus on cross-country skiers. This thesis also aimed to assess the effects of subzero temperature and physical activity on healthy human airways.Methods: Study 1 (papers I-II) consisted of an annual postal questionnaire investigating asthma prevalence and predictors of asthma that was sent to invited athletes in 2011–2015. Invited athletes were Swedish elite cross-country skiers, biathletes, ski orienteers, and orienteers from Swedish National Elite Sport Schools, national teams, and Swedish Ski Universities, or top orienteers according to national ranking. Former Swedish Olympic skiers and an adolescent reference group were invited in 2013. Paper I included cross-sectional data from 2011 for adolescents/adults and from 2013 for former skiers (n=491). Paper II included adolescent elite skiers (n=253) from the Swedish National Elite Sport Schools invited during 2011-2013, as well as a reference group (n=500) aged 16-20 years that was matched for school municipalities and invited in 2013. Study 2 (papers III-IV) comprised whole-body experimental exposure of healthy adults to sub-zero temperatures and exercise in an environmental chamber. Lung function and biochemical markers in plasma and urine were measured before and after exposure. Symptoms were investigated before, during, and after exposure. In both trials, study subjects were exposed for 50 min on two separate occasions in randomized order. Paper III comprised 31 subjects and moderate-intensity exercise (30 min running at 62-78% of VO2max), at 10°C vs. -10°C. Paper IV included 29 subjects and hard-intensity exercise (30 min of running at 85% of VO2max) vs. rest, both at a temperature of -15°C.Results: In paper I, the overall response rate was 82%. Athletes reporting asthma in the different age categories were: 29% of skiers (38% of the female skiers) and 17% of orienteers (p=0.071) among 15 to 19-year-olds; 35% of skiers and 16% of orienteers (p=0.029) among 20 to 34-year-olds; and 22% of the skiers aged 40–94 years. Asthma onset occurred in adolescence among the active athletes. Increasing age, female sex, allergy, family history of allergy/asthma, and being a skier were predictors of self-reported physician-diagnosed asthma. In paper II, the response rate was 96% for skiers and 48% for the reference group. Skiers reported a higher prevalence of self-reported physician-diagnosed asthma than the reference population (27% vs. 19%, p=0.046). Physician-diagnosed asthma was more frequently reported by female skiers than male skiers (34% vs. 20%, p=0.021). Median age at asthma onset was higher among skiers than in the reference population (12.0 vs. 8.0 years; p<0.001). Female sex, family history of asthma, nasal allergy, and being a skier were risk factors associated with self-reported physician-diagnosed asthma. In paper III, exercise at -10°C decreased FEV1 (p=0.002) and FEV1/FVC (p<0.001) and increased resistance at 20 Hz (p=0.016) to similar magnitudes as exercise at 10°C. Exercise at 10°C increased reactance (p=0.005), which differed (p=0.042) from a less pronounced response after exercise at -10°C. Plasma CC16 increased similarly after both exposures, without significant differences. More intense symptoms from the upper airways were reported after exercise at -10°C than at 10°C. Symptoms from the lower airways were few and mild. In paper IV, FEV1 decreased from baseline after both rest (p<0.001) and exercise (p=0.012) at -15°C, with no differences between exposures. Compared to rest, exercise at -15°C induced greater increases in reactance (p=0.023), plasma CC16 (p<0.001), and plasma IL-8 (p<0.001). Exercise gave rise to more intense symptoms from the lower airways, whereas rest induced more general symptoms.Conclusions: In the 1990s, a high prevalence of physician-diagnosed asthma was reported among Swedish elite cross-country skiers, and our studies show that this has not changed. Asthma onset commonly occurs in early adolescence among skiers, in the beginning of their career. Being an elite skier is an independent risk factor associated with asthma. Targeted preventive measures should be introduced at an early age to avoid the development of asthma in endurance athletes. Healthy individuals performing short-duration moderate- and hard-intensity exercise in sub-zero temperatures responded with lung function changes and an increased airway permeability. These findings warrant further research on airway responses to sub-zero temperatures in vulnerable individuals such as elite endurance athletes.
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| 7. |
- Eklund, Linda M., et al.
(författare)
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Cold air exposure at -15 °C induces more airway symptoms and epithelial stress during heavy exercise than rest without aggravated airway constriction
- 2022
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Ingår i: European Journal of Applied Physiology. - : Springer. - 1439-6319 .- 1439-6327. ; 122:12, s. 2533-2544
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Exposure to cold air may harm the airways. It is unclear to what extent heavy exercise adds to the cold-induced effects on peripheral airways, airway epithelium, and systemic immunity among healthy individuals. We investigated acute effects of heavy exercise in sub-zero temperatures on the healthy airways.Methods: Twenty-nine healthy individuals underwent whole body exposures to cold air in an environmental chamber at − 15 °C for 50 min on two occasions; a 35-min exercise protocol consisting of a 5-min warm-up followed by 2 × 15 min of running at 85% of VO2max vs. 50 min at rest. Lung function was measured by impulse oscillometry (IOS) and spirometry before and immediately after exposures. CC16 in plasma and urine, and cytokines in plasma were measured before and 60 min after exposures. Symptoms were surveyed pre-, during and post-trials.Results: FEV1 decreased after rest (− 0.10 ± 0.03 L, p < 0.001) and after exercise (− 0.06 ± 0.02 L, p = 0.012), with no difference between trials. Exercise in − 15 °C induced greater increases in lung reactance (X5; p = 0.023), plasma CC16 (p < 0.001) as well as plasma IL-8 (p < 0.001), compared to rest. Exercise induced more intense symptoms from the lower airways, whereas rest gave rise to more general symptoms.Conclusion: Heavy exercise during cold air exposure at − 15 °C induced signs of an airway constriction to a similar extent as rest in the same environment. However, biochemical signs of airway epithelial stress, cytokine responses, and symptoms from the lower airways were more pronounced after the exercise trial.
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| 8. |
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| 9. |
- Eriksson, Linda, et al.
(författare)
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Symptom av måttlig träning i minusgrader : En experimentell exponeringsstudie
- 2018
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Bakgrund: Exponering för kyla leder till ökad sjuklighet och dödlighet i befolkningen. Tidigare studier av symptom i samband med köldexponering har mestadels varit befolkningsbaserade enkätstudier fokuserade på ett smalt symptomspektrum. Syftet meddenna studie var att undersöka effekten av kyla och fysisk aktivitet på ett brett spektrumav symptom hos friska individer.Material och metod: Trettioen friska försökspersoner exponerades i en köldkammare för +10 °C och -10 °C under en timme, vid två separata tillfällen. Under varje exponeringsprang försökspersonerna intermittent på 62-78% av maximal syreupptagningsförmåga. Vid fem tillfällen, före, under och efter exponeringarna, frågades försökspersonerna om 18 symptom och dessas intensitet. Borgs CR10 skala användes för att skatta intensitetenfrån 0 till 11, där 0 betydde ”inget alls” och 11 betydde ”maximalt”. Maximalt Borg-värdeför varje symptom under exponeringarna jämfördes med värdena innan exponeringarna. Summan av alla fem Borg CR10-värdena jämfördes mellan de två exponeringarna. PairedWilcoxon signed-rank test användes för analyser. Data presenteras som medianvärden.Resultat: En signifikant stegring av symptomen hosta, ögonirritation, fysiskt obehag ochkalla extremiteter förekom endast vid -10 °C. I jämförelse med fysisk aktivitet i +10 °C, gav fysisk aktivitet i -10 °C upphov till signifikant högre summerade värden för ögonirritation 2,0 jfr 0,5 (p=0,011), rinit 12,0 jfr 8,0 (p=0,000), irritation i näsan 3,5 jfr 0,5 (p=0,001), kyla i ansiktet 7,0 jfr 1,0 (p=0,000), fysiskt obehag 6,5 jfr 0,0 (p=0,000), och kalla extremiteter 10,0 jfr 0,5 (p=0,000).Slutsats: Hos friska individer kan fysisk aktivitet på måttlig intensitet i -10 °C ge upphovtill och öka intensiteten av ett brett spektrum av symptom. Symptom från de nedre luftvägarna var milda och inte frekventa vid de aktuella exponeringarna.
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| 10. |
- Eriksson, Linda, et al.
(författare)
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Symptoms of moderate exercise in subzero temperatures - An experimental exposure study
- 2018
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Ingår i: European Respiratory Journal. - : European Respiratory Society. - 0903-1936 .- 1399-3003. ; 52
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Humans react to cold with various symptoms. Previous studies enquiring about symptoms during cold exposure have for the most part been population based studies using questionnaries and have focused on a narrow spectrum of symptoms. The purpose of this study was to study the effect of cold air and physical exercise on a wide range of symptoms in healthy individuals.A total of 31 healthy subjects were experimentally exposed to +10 °C and -10 °C in an environmental chamber for one hour, on two separate occasions. During each exposure, subjects performed an intermittent moderate-intensity running protocol between 62-78% of maximal oxygen consumption (VO2 max). At five timepoints, before, during and after the exposures, subjects were asked about 18 symptoms and their intensity. The Borg CR10 scale was used to rate the intensity from 0 to 11, where 0 meant "none" and 11 meant "maximal". The sum of all five Borg CR10-scores were added together to form a single score for each exposure. Paired Wilcoxon signed-rank test was used for analysis. Data are presented as medians.Symptoms of cough, eye irritation, physical discomfort, and cold extremities were present only at -10 °C. Compared to exercise in +10 °C, exercise in -10 °C induced significantly higher summed symptom scores for eye irritation 2.0 vs 0.5 (p=0.011), rhinitis 12.0 vs 8.0 (p=0.000), nasal irritation 3.5 vs 0.5 (p=0.001), cold face 7.0 vs 1.0 (p=0.000), physical discomfort 6.5 vs 0.0 (p=0.000), and cold extremities 10.0 vs 0.5 (p=0.000).In healthy subjects, moderate-intensity exercise in -10 °C can induce and enhance the intensity of a wide range of symptoms. Symptoms of the lower airways were infrequent and mild.
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