| 1. |
|
|
| 2. |
|
|
| 3. |
- Bjerg Bäcklund, Anders, 1982-
(författare)
-
Epidemiology of asthma in primary school children
- 2008
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Childhood asthma has increased worldwide, although recent studies report a prevalence plateau in some western countries.Aims: To investigate the prevalence of asthma and the associated risk factor patterns from ages 7-8 to 11-12 with special emphasis on the hereditary component, and further to study prevalence trends at age 7-8 from 1996 to 2006 and the possible determinants of these trends.Methods: The studies involved two cohorts from Kiruna, Luleå and Piteå: one previously identified cohort of 3430 children age 7-8 followed by yearly questionnaires until age 11-12 with 97% yearly participation. Skin-prick tests for allergic sensitisation were performed at ages 7-8 and 11-12 in subsets of 2148 and 2155 children respectively (88% of invited). In 2006 a new cohort of 7-8-year-olds was identified and examined identically. 2585 (96% of invited) and 1700 (90% of invited) participated in the questionnaire and skin-prick tests, respectively. The questionnaire included questions about symptoms of asthma, allergic rhinitis and eczema, and possible risk factors.Results: In the 1996 cohort, from age 7-8 to 11-12 the prevalence of physician-diagnosed asthma increased (5.7%-7.7%, P<0.01) while current wheeze decreased (11.7%-9.4%, P<0.01), and 34.7% reported ever wheee at ≥one occasion. Remission was 10% of which half relapsed during the study. Remission was significantly lower among sensitised children. The strongest risk factors for current asthma at ages 7-8 and 11-12 were allergic sensitisation (OR 5) and family history of asthma (OR 3). Several other significant risk factors, e.g. respiratory infections, damp house and low birth weight, had lost importance at age 11-12. At age 7-8, parental asthma was a stronger risk factor (OR 3-4) than parental rhinitis or eczema (OR 1.5-2). Sibling asthma had no independent effect. Biparental asthma had a multiplicative effect (OR 10). Maternal and paternal asthma was equally important, regardless of the child’s sex and sensitisation status.From 1996 to 2006 the prevalence of current wheeze and asthma at age 7-8 did not increase (P=0.13, P=0.18), while lifetime prevalence of ever wheeze and physician-diagnosed asthma increased (P<0.01, P=0.01). Symptoms of rhinitis and eczema were unchanged, despite 45% increase (P<0.01) in allergic sensitisation. For current asthma the adjusted population attributable fractions of sensitisation and parental asthma increased (35%-41%, 27%-45%). This was however balanced by decreased exposure to infections, maternal smoking and home dampness, resulting in stable asthma prevalence. Stratification by sex revealed that current wheeze increased in boys (P<0.01) but tended to decrease in girls (P=0.37), seemingly due to symptom persistence in males. Several asthma indices followed this pattern. The boy-to-girl ratio in exposure to all studied risk factors increased, which may explain the sex-specific prevalence trends in wheeze.Conclusions: The prevalence of current asthma and wheeze did not increase statistically significantly. However, the risk factor pattern has changed considerably since 1996, which will presumably affect the clinical features of childhood wheeze in this region. Sex-specific trends in wheeze can be explained by changes in exposure, and trends in risk factors should be explored parallel to prevalence trends.
|
|
| 4. |
- Bosson, Jenny, et al.
(författare)
-
Diesel exhaust exposure enhances the ozone-induced airway inflammation in healthy humans
- 2008
-
Ingår i: European Respiratory Journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 31:6, s. 1234-1240
-
Tidskriftsartikel (refereegranskat)abstract
- Exposure to particulate matter and ozone cause adverse airway reactions. Individual pollutant effects are often addressed separately, despite coexisting in ambient air. The present investigation was performed to study the effects of sequential exposures to diesel exhaust (DE) and ozone on airway inflammation in human subjects. Healthy subjects underwent bronchoscopy with bronchoalveolar lavage (BAL) and bronchial wash (BW) sampling on two occasions. Once following a DE exposure (with 300 mug.m(-3) particles with a 50% cut-off aerodynamic diameter of 10 mum) with subsequent exposure to O(3) (0.2 ppm) 5 h later. The other bronchoscopy was performed after a filtered air exposure followed by an ozone exposure, using an identical protocol. Bronchoscopy was performed 24 h after the start of the initial exposure. Significant increases in neutrophil and macrophage numbers were found in BW after DE followed by ozone exposure versus air followed by ozone exposure. DE pre-exposure also raised eosinophil protein X levels in BAL compared with air. The present study indicates additive effects of diesel exhaust on the ozone-induced airway inflammation. Together with similar results from a recent study with sequential diesel exhaust and ozone exposures, the present data stress a need to consider the interaction and cumulative effects of different air pollutants.
|
|
| 5. |
- Crüts, Björn, et al.
(författare)
-
Exposure to diesel exhaust induces changes in EEG in human volunteers.
- 2008
-
Ingår i: Particle and Fibre Toxicology. - : Springer Science and Business Media LLC. - 1743-8977. ; 5, s. 4-
-
Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: BACKGROUND: Ambient particulate matter and nanoparticles have been shown to translocate to the brain, and potentially influence the central nervous system. No data are available whether this may lead to functional changes in the brain. METHODS: We exposed 10 human volunteers to dilute diesel exhaust (DE, 300 mug/m3) as a model for ambient PM exposure and filtered air for one hour using a double blind randomized crossover design. Brain activity was monitored during and for one hour following each exposure using quantitative electroencephalography (QEEG) at 8 different sites on the scalp. The frequency spectrum of the EEG signals was used to calculate the median power frequency (MPF) and specific frequency bands of the QEEG. RESULTS: Our data demonstrate a significant increase in MPF in response to DE in the frontal cortex within 30 min into exposure. The increase in MPF is primarily caused by an increase in fast wave activity (beta2) and continues to rise during the 1 hour post-exposure interval. CONCLUSION: This study is the first to show a functional effect of DE exposure in the human brain, indicating a general cortical stress response. Further studies are required to determine whether this effect is mediated by the nanoparticles in DE and to define the precise pathways involved.
|
|
| 6. |
|
|
| 7. |
- Ericsson, Eva, et al.
(författare)
-
Is the P600/affected by the richness of semantic content? : a linguistic ERP study in Swedish
- 2008
-
Ingår i: Scandinavian Journal of Psychology. - : Wiley. - 0036-5564. ; 49, s. 1-9
-
Tidskriftsartikel (refereegranskat)abstract
- The study investigated whether the P600/SPS component is sensitive to the richness of semantic content in sentences. ERPs were recorded while 30 native Swedish speakers read sentences, of which half were syntactically correct and half contained a syntactic violation. Both kinds of sentences came in one of three types of descending semantic completeness: semantically coherent sentences, sentences which were incoherent due to violations of selectional restrictions, or sentences of pseudo words, hence void of lexical content. In the semantically coherent sentences a P600/SPS was found for the syntactic violation. A less salient positivity was found for the violation in the semantically incoherent sentences. No P600/SPS was found for the syntactic violation in the pseudo word sentences and no LAN component in any sentence type. The results are interpreted as supporting the hypothesis that the P600/SPS component reflects a semantically based reanalysis process.
|
|
| 8. |
- Fors, Yvonne, et al.
(författare)
-
Sulfur Accumulation in Pine Wood (Pinus sylvestris) Induced by Bacteria in Simulated Seabed Environment : Implications for Marine Archaeological Wood and Fossil Fuels
- 2008
-
Ingår i: International Biodeterioration & Biodegradation. - 0964-8305 .- 1879-0208. ; :62, s. 336-347
-
Tidskriftsartikel (refereegranskat)abstract
- Fresh pine wood blocks were submerged in sulfate and iron(II) containing media, inoculated with bacterial consortia isolated from seawater, aiming to simulate the seabed conditions of the Vasa shipwreck (1628). The consortia contained erosion (EB) and sulfate-reducing bacteria (SRB). Sulfur K-edge x-ray absorption near edge structure (XANES) spectroscopy and scanning x-ray spectromicroscopy images showed that organic sulfur, mainly thiols (R-SH), had accumulated in the lignin-rich middle lamella in EB-degraded parts of the wood. The sulfur content in the wood increased more than 10 times in two years. In another series with active inoculums from marine archaeological wood, the sulfur XANES spectra showed after four years anaerobic treatment considerable amounts also of inorganic iron sulfides, Fe1-xS, which oxidized at atmospheric exposure. A sediment sample from the Vasa’s seabed was also rich in iron sulfides, including pyrite FeS2. X-ray fluorescence mappings of sulfur and phosphorous distributions indicate that scavenging SRB penetration, producing hydrogen sulfide in situ, is restricted to EB-degraded parts of the wood structure. The sulfur isotope depletion of 34S from d34S = 21‰ in marine sulfate to d34S = 6‰ and 1.8‰ for fractions of reduced sulfur and sulfate separated from a Vasa wood sample, respectively, suggests bacterial transformation. A fuller understanding of the routes of sulfur accumulation, as reactive iron sulfides and as organic sulfur, has important implications for improving conservation methods of marine archaeological wood. Moreover, the biogenic accumulation of organically bound sulfur specifically in lignin-rich parts of waterlogged wood has wider geochemical significance for fossil fuels of marine origin, as lignin-rich humic matter is important for the diagenetic formation of kerogens from anoxic marine sediments.
|
|
| 9. |
- Frisk, Thomas, et al.
(författare)
-
An integrated QCM-based narcotics sensing microsystem
- 2008
-
Ingår i: Lab on a Chip. - : RSC Publishing. - 1473-0197 .- 1473-0189. ; 8:10, s. 1648-1657
-
Tidskriftsartikel (refereegranskat)abstract
- We present the design, fabrication and successful testing of a 14 x 14 x 4 mm(3) integrated electronic narcotics sensing system which consists of only four parts. The microsystem absorbs airborne narcotics molecules and performs a liquid assay using an integrated quartz crystal microbalance (QCM). A vertically conductive double-sided adhesive foil (VCAF) was used and studied as a novel material for LOC and MEMS applications and provides easy assembly, electrical contacting and liquid containment. The system was tested for measuring cocaine and ecstasy, with successful detection of amounts as small as 100 ng and 200 ng, respectively These levels are of interest in security activities in customs, prisons and by the police.
|
|
| 10. |
|
|
