| 1. |
- Barraza-Villarreal, Albino, et al.
(författare)
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Air pollution, airway inflammation, and lung function in a cohort study of Mexico City schoolchildren.
- 2008
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Ingår i: Environmental health perspectives. - : Environmental Health Perspectives. - 0091-6765 .- 1552-9924. ; 116:6, s. 832-8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The biological mechanisms involved in inflammatory response to air pollution are not clearly understood. OBJECTIVE: In this study we assessed the association of short-term air pollutant exposure with inflammatory markers and lung function. METHODS: We studied a cohort of 158 asthmatic and 50 nonasthmatic school-age children, followed an average of 22 weeks. We conducted spirometric tests, measurements of fractional exhaled nitric oxide (Fe(NO)), interleukin-8 (IL-8) in nasal lavage, and pH of exhaled breath condensate every 15 days during follow-up. Data were analyzed using linear mixed-effects models. RESULTS: An increase of 17.5 microg/m(3) in the 8-hr moving average of PM(2.5) levels (interquartile range) was associated with a 1.08-ppb increase in Fe(NO) [95% confidence interval (CI), 1.01-1.16] and a 1.07-pg/mL increase in IL-8 (95% CI 0.98-1.19) in asthmatic children and a 1.16 pg/ml increase in IL-8 (95% CI, 1.00-1.36) in nonasthmatic children. The 5-day accumulated average of exposure to particulate matter <2.5 microm in aerodynamic diamter (PM(2.5)) was significantly inversely associated with forced expiratory volume in 1 sec (FEV(1)) (p=0.048) and forced vital capacity (FVC) (p=0.012) in asthmatic children and with FVC (p=0.021) in nonasthmatic children. Fe(NO) and FEV(1) were inversely associated (p=0.005) in asthmatic children. CONCLUSIONS: Exposure to PM(2.5) resulted in acute airway inflammation and decrease in lung function in both asthmatic and nonasthmatic children.
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| 2. |
- Behndig, Annelie, 1963-
(författare)
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Airway antioxidant responses to oxidative air pollution and vitamin supplementation
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Air pollutants, such as ozone (O3) and diesel exhaust particles, elicit oxidative stress in the lung. Antioxidants within the respiratory tract lining fluid (RTLF) protect the underlying tissue from oxidative injury. Supplementation with vitamins has been shown to modulate the acute ozone-induced effects, but the mechanisms behind this have not been fully clarified. The aim of this thesis was to investigate the airway responses to diesel exhaust and ozone exposure in healthy humans, with the emphasis on inflammatory and antioxidant responses. Furthermore, to study whether oral supplementation with vitamin C could increase ascorbate concentration in the RTLF and whether vitamin supplementation could modulate the negative effects induced by ozone exposure. Diesel exhaust (100 µg/m3 PM10 for 2h), evaluated 18 hours post exposure (PE), induced a neutrophilic airway inflammation and an increase in bronchoalveolar (BAL) urate and reduced glutathione. During O3 exposure (0.2 ppm for 2h), significant losses of nasal RTLF urate and ascorbate concentrations were observed. Six hours PE, a neutrophilic inflammation was evident in the bronchial wash (BW), together with enhanced concentrations of urate and total glutathione. In the bronchoalveolar lavage (BAL), where vitamin C, urate and glutathione concentrations were augmented, no inflammatory response was seen. In alveolar lavage leukocytes, there was a significant loss of glutathione and cysteine, whereas an increase in ascorbate was found in bronchial tissue samples. Following supplementation with increasing doses of vitamin C (60-1,000 mg/day, for 14 days), evaluated 24 hours after the last dose, ascorbate concentrations were unchanged in the nasal RTLF, despite elevated concentrations in plasma and urine. In contrast, following a single dose of 1g of vitamin C, vitamin C concentrations increased significantly in both plasma and nasal lavage two hours post supplementation, before returning to baseline levels at 24 hours. Notably, dehydroascorbate (DHA) accounted for the largest part of RTLF vitamin C and a number of control experiments were performed to ensure the authenticity of this finding. Healthy O3 responders were exposed to O3 (0.2 ppm for 2 h) and air, following seven days of supplementation with vitamin C and E or placebo. No protective effect on lung function or airway inflammation was observed following supplementation. BW and BAL-DHA were enhanced after O3, with further increases following supplementation. In conclusion, oxidative air pollutants induce airway inflammation, as well as a broad spectrum of antioxidant adaptations, which could ultimately limit the airway inflammatory responses. Oral vitamin supplementation was shown to augment RTLF-vitamin C concentrations, but it did not provide protection from the ozone-induced airway responses following a single insult of ozone. The finding of high concentrations of DHA in the RTLF could indicate that DHA represents an important transport form of vitamin C onto the surface of the lung.
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| 3. |
- Pala, Valeria, et al.
(författare)
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Meat, eggs, dairy products, and risk of breast cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort.
- 2009
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Ingår i: The American journal of clinical nutrition. - : Elsevier BV. - 1938-3207 .- 0002-9165. ; 90:3, s. 602-612
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A Western diet is associated with breast cancer risk. OBJECTIVE: We investigated the relation of meat, egg, and dairy product consumption with breast cancer risk using data from the European Prospective Investigation into Cancer and Nutrition (EPIC). DESIGN: Between 1992 and 2003, information on diet was collected from 319,826 women. Disease hazard ratios were estimated with multivariate Cox proportional hazard models. RESULTS: Breast cancer cases (n = 7119) were observed during 8.8 y (median) of follow-up. No consistent association was found between breast cancer risk and the consumption of any of the food groups under study, analyzed by both categorical and continuous exposure variable models. High processed meat consumption was associated with a modest increase in breast cancer risk in the categorical model (hazard ratio: 1.10; 95% CI: 1.00, 1.20; highest compared with lowest quintile: P for trend = 0.07). Subgroup analyses suggested an association with butter consumption, limited to premenopausal women (hazard ratio: 1.28; 95% CI: 1.06, 1.53; highest compared with lowest quintile: P for trend = 0.21). Between-country heterogeneity was found for red meat (Q statistic = 18.03; P = 0.05) and was significantly explained (P = 0.023) by the proportion of meat cooked at high temperature. CONCLUSIONS: We have not consistently identified intakes of meat, eggs, or dairy products as risk factors for breast cancer. Future studies should investigate the possible role of high-temperature cooking in the relation of red meat intake with breast cancer risk.
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| 4. |
- 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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