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Notes: Background and objective The increasing urbanization and the decrease in the numbers of farms in southern Germany might be associated with an increasing prevalence of allergic diseases. We compared the prevalence of allergic diseases in farmers, and rural, suburban and urban residents in the small geographical area of Augsburg in southern Germany.Methods In a cross-sectional survey adults, aged 25–75 years selected from the community population register were investigated. Rural, suburban and urban residents were defined by community size and farmers by occupation. Allergic respiratory disorders were assessed by self-administered questionnaires and specific IgE antibodies to five common aeroallergens.Results In comparison to rural residents the urban population had an increased risk of allergic rhinitis (OR = 1.5; 95% CI: 1.2–1.9), atopic sensitization (OR = 1.2; 95% CI: 1.0–1.4) and sensitization against pollen (OR = 1.5; 95% CI: 1.2–1.9). There was no difference in the risk of asthma (OR = 1.0; 95% CI: 0.6–1.6) and a decreased risk in the sensitization against house dust mite (OR = 0.8; 95% CI: 0.7–1.0). The suburban residents did not differ from urban residents. Farmers had lower risks in allergic rhinitis, atopic sensitization, sensitization against pollen and mites (OR = 0.63; 0.86; 0.51 and 0.80, respectively) than rural non-farming residents, however, these differences were statistically not significant. Reported allergic rhinitis with sensitization to pollen was 2.5 times (95% CI: 1.8–3.6) more prevalent in urban than in rural residents.Conclusion A farming environment and rural lifestyle might be associated with unknown protective factors impacting the prevalence of allergies.

Notes: Background The ADAM33 gene has recently been associated with asthma and bronchial hyper-reactivity. It codes for a disintegrin and metalloproteinase that triggers intra- and extracellular signalling by protein shedding.Objective We examined whether polymorphisms in ADAM33 are associated with asthma and related traits in two German populations.Methods We genotyped 15 intragenic single-nucleotide polymorphisms (SNPs) by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of allele-specific primer extension products. The transmission disequilibrium test was used for association analysis in the German asthma family study. Additionally, we tested for association of these SNPs in a case–control sample from the European Community Respiratory Health Study using Armitage's trend test.Results In both studies, we found SNPs that were significantly associated with asthma and related traits. In the family study, significant associations were observed for the SNPs F+1, ST+4 and ST+5 (with the lowest P-value for F+1, P=0.005). Remarkably, this association is seen even in the absence of linkage with two microsatellite markers from a previous genome scan either 3.1 million bases (Mb) up- or 5.6 Mb downstream. In the case–control study, SNP ST+7 (P=0.008) was significantly associated with asthma. Some of these SNPs overlapped with those found to be associated with elevated total IgE levels and bronchial hyper-responsiveness.Conclusion This study replicates the recently published association between asthma and ADAM33 gene variants. However, most of the associated SNPs were at non-identical positions in the German, UK and US samples. As linkage disequilibrium is high among the tested SNPs, and there is no known functional polymorphism, either not-tested variants in ADAM33, unknown regulatory elements or a gene in close proximity is responsible for this association.

Notes: Background Exposure to endotoxin in childhood is currently discussed to protect from the development of allergic diseases.Objective To study the effect of early endotoxin exposure on incidence of atopic sensitization, atopic dermatitis and wheezing until the age of 2 years in infants with different risk status in terms of parental atopy.Methods Data of 1942 infants of an ongoing birth cohort study were analysed by logistic regression. Endotoxin was measured in settled dust of the mothers' mattresses at infants' age of 3 months. Data on allergic symptoms and physicians' diagnoses were gathered by questionnaire. Sensitization to common food and inhalant allergens was assessed by specific serum IgE.Results High endotoxin levels increased the risk of repeated wheeze [adjusted odds ratio (OR) for 4th exposure quartile (Q4) 1.52, 95% confidence interval (CI) 1.08–2.14], but were associated with neither sensitization to food allergens nor atopic dermatitis. Stratification by parental atopy showed that there was an association of endotoxin exposure with incidence of repeated wheeze as well as with sensitization to inhalant allergens (P for trend = 0.008 and 0.044, respectively) only in infants with parental atopy, with the highest risk in the 4th exposure quartile (repeated wheeze: ORQ4 1.77, 95% CI 1.14–2.73; sensitization to inhalant allergens: ORQ4 1.69, 95% CI 0.70–4.11).Conclusion Early endotoxin exposure in terms of mattress dust endotoxin levels seemed to increase the risk of atopic reactions to inhalant allergens at the age of 2 years, especially in infants at risk due to parental atopy. Our data disagree with an early protective effect of endotoxin on atopy development until the age of 2 years.

Notes: Background The increase in allergic diseases is still unexplained. It was hypothesized that the intake of unsaturated fatty acids is a contributing cause of this development. We investigated the relationship between serum cholesterol levels, intake of polyunsaturated fatty acids (PUFA) and manifestations of atopy in a population-based setting.Methods A nested case–control study was performed within the population of the 3rd MONICA survey in Augsburg (Germany). The serum levels of total, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol of 1537 adults (aged 28–78 years, response 61.4%) and the estimated intake of PUFA in a subset of 139 men were compared with the frequency of a doctor's diagnosis of asthma, allergic rhinoconjunctivitis (AR), atopic eczema (AE) and allergic sensitization as measured by skin prick and Radio Allergo Sorbent Test.Findings In bivariate analyses, we obtained a negative linear association between total and LDL cholesterol levels and the frequency of AR and sensitization, which was no longer significant after adjustment for important confounders. In contrast, positive linear associations were found between HDL cholesterol levels and AR and AE and, furthermore, between the intake of PUFA and allergic sensitization in men (P〈0.01). After adjustment, an increasing risk for atopic diseases with increasing levels of HDL cholesterol and an increasing risk for allergic sensitization with increasing intakes of PUFA remained statistically significant.Interpretation There is indication that HDL cholesterol also plays a role in the complex interaction of fat intake, metabolism and the manifestation of atopy in adults. These findings may contribute to the understanding of time trends and regional differences of allergies.

Notes: Background Previous studies have shown that the risk for allergic sensitization is lower in children who grew up on farms and in young adults who were exposed to dogs in early childhood. A higher microbial exposure in general and in particular to endotoxin in early childhood might contribute to this lower risk of atopy.Objective We examined whether the presence of pets or vermin in the home is associated with higher endotoxin concentrations in settled house dust.Methods House dust was sampled in a standardized manner on the living room floors of 454 homes of German children aged 5–10 years (participation rate 61%). Endotoxin was assessed with a quantitative kinetic chromogenic Limulus Amebocyte Lysate (LAL) method. Associations between endotoxin levels, pets and vermin are presented as ratios of the crude and confounder adjusted geometric means (means ratios) in the category of study vs. a reference category using multiple linear regression models.Results Endotoxin concentrations in living room floor dust sampled in homes without pets and vermin were lower (1246 ng per square meter, 1519 ng endotoxin/g dust, n = 157) than those sampled in homes with pets or vermin (2267 ng per square meter, 2200 ng endotoxin/g dust, n = 296). After adjustment for city of residence, season of dust sampling, age of the building and story of the dwelling, means ratios for endotoxin expressed per gram of dust were statistically significantly increased for dog (1.64, 95% CI 1.09–2.46), for cat (1.50, 95% CI 1.03–2.18) and for cockroach (3.01, 95% CI 1.37–6.60), whereas no major statistically significant associations were found for other pets, ants and mice.Conclusion Keeping a dog or a cat in the home is consistent with higher exposure to endotoxin and might therefore contribute to the lower risk of atopy in later life.

Notes: Background Atopic diseases develop on a genetic background and are modulated by environmental factors among which some infectious diseases are thought to have a protective influence.Objective The aim of this study was to determine the influence of infectious diseases in younger ages, bacterial and viral, on atopic diseases and sensitization to aero- and foodallergens in adults.Methods A population-based sample of 4262 subjects aged 25–74 years were interviewed concerning their history of infectious disease within the first 18 years of life. Information about allergic disease, including atopic eczema, allergic rhinitis (AR), and asthma was obtained. A blood sample was drawn and analysed for allergen-specific IgE antibodies against food- and aeroallergens.Results Multiple logistic regression analyses identified viral infection to be associated with AR (adjusted odds ratio (OR)=1.39; 95% confidence interval (95% CI): 1.13–1.72) and sensitization to aeroallergens (OR=1.21; 95% CI: 1.05–1.41). Bacterial disease was a negative predictor for atopy development in the subgroup of patients sensitized to nutritional allergens with concomitant atopic eczema (OR=0.34; 95% CI: 0.11–0.99), AR (OR=0.67; 95% CI: 0.42–1.07), or asthma (OR=0.41; 95% CI: 0.19–0.87). Influences of viral and bacterial infection on AR differed with regard to family history of atopic disease.Conclusion In our study population, history of viral infection was consistently positively associated with AR. Our data suggests that bacterial infections might be preventive for specific subgroups of atopy.

Notes: It is widely known and accepted that grass pollen is a major outdoor cause of hay fever. However, it is of virtual importance for grass pollen allergic patients with symptoms all the year round to know the concentration of grass pollen allergens in their homes.〈section xml:id="abs1-2"〉〈title type="main"〉ObjectiveThe main objective of this study was to quantify the amount of grass pollen allergen in mass units (μg Phl p 5) in dust settled indoors and to detect the distribution of allergenic activity in different sampling locations of homes. Furthermore, we studied the seasonal fluctuation of allergen content in dust samples.〈section xml:id="abs1-3"〉〈title type="main"〉MethodsWe adapted the two site binding assay for detection of group 5 grass pollen allergens in samples from randomly selected homes in Hamburg (n = 371), Erfurt (n = 396), Hettstedt (n = 353), Zerbst (n = 289) and Bitterfeld (n = 226), Germany. Dust samples were collected from floor of living room (LR), bedroom (BR) or children's room (CR) and mattress (MA) during period of June 1995 to August 1998. The amount of the major grass group 5 allergens was detected in μg/g dust.〈section xml:id="abs1-4"〉〈title type="main"〉ResultsPhl p 5 was detected in 67% of the samples analysed (n = 4760). The range was between undetectable (〈 0.03 μg/g dust) and 81 μg/g dust. Phl p 5 levels were significantly higher in the dust from LR (geometric mean 0.117 μg/g dust) or BR/CR floors (geometric mean 0.098 μg/g dust) than in mattresses (geometric mean 0.043 μg/g dust). We observed seasonal fluctuation of indoor Phl p 5 levels with peak in June but also annual differences. Thus Phl p 5 content indoors reflects also the different quantities of pollen counts of annual courses. During pollination period we found two times higher Phl p 5 levels (0.172 μg/g dust, P 〈 0.001) than outside of grass pollination season (0.095 μg/g dust). The indoor Phl p 5 levels outside of season seem to be independent of pollination before. We suppose that settled pollen grains or allergenic material from outdoor particles carried indoors via footwear and clothes accumulates in house dust.〈section xml:id="abs1-5"〉〈title type="main"〉ConclusionAlthough we not known how the allergens in settled dust are equilibrated with those in the air, the considerable high level of Phl p 5 in indoor dust even during periods when no grass pollen is present in the atmosphere may be an important cause of pollen-allergy symptoms outside of season.

Notes: Background  Studies investigating the effect of exposure to indoor allergens and endotoxin on human respiratory health usually take dust samples only at one single point of time and consider them to be representative for the indoor biocontaminant burden during a time period of several years. This singly measured biocontaminant concentration is related to adverse respiratory outcomes such as asthma, wheeze or others.Objective  We analysed two repeated measurements of mite and cat allergens in mattress and living room floor dust as well as endotoxin concentrations in living room floor dust. The repeated samples were taken over a time period of about 6 years. We investigated the repeatability over time of their concentrations by determining correlation coefficients and computing within- and between-home variance components.Methods  Our analysis was based on the population of a study on Indoor Factors and Genetics in Asthma (INGA) being carried out in 1995/96 and followed up in 2000/01. Complete data were available from 152 participants.Results  The measured allergen concentrations were low and a considerable percentage of the values was below the limit of detection. The crude Spearman's rank correlation coefficients between the two measurements taken in 1995/96 and 2000/01 ranged from 0.32 to 0.61 for the dust mites allergens, from 0.21 to 0.44 for cat allergen and from 0.35 to 0.51 for endotoxin. Correlations were higher if measurements were performed on the same floor or the same mattress at both sampling time-points. The within-home variance for all measured biocontaminant concentrations was of about the same order as the between-home variance.Conclusion  For studies like ours with low allergen and endotoxin concentrations, the repeatability of these concentrations over a time period as long as 6 years is low and a single measurement does not accurately reflect the true long-term exposure in the homes.

Notes: Reproducible growth of well-aligned nanostructures with an average nearest-neighbor distance of a few hundred nanometers is achieved on an array of strong nucleation sites provided by the facetted TiC(111) surface. The growth of the complex shaped nanostructures, composed out of carbon encapsulated TiCx crystallites interconnected by nanorods, 25 nm in diameter, is fed by the thermal decomposition of TiC. The length of the nanorods and the shape of the nanocrystallites is determined by the applied annealing program. © 2000 American Institute of Physics.

Notes: Background:  This study examined the association of maternal oral contraceptive (OC) use – before and after birth – and atopic manifestations in the offspring.Methods:  A total of 2754 East German children aged 5–14 years participated in a cross-sectional survey in 1998–99. The standardized parental questionnaire in 1998–99 included data on atopic diseases, socio-economic factors, parental atopy and maternal OC use. Specific immunoglobulin E against common inhalant allergens was measured by radioallergosorbent test (RAST).Results:  Maternal OC use before birth was associated with a higher risk of atopic diseases in the offspring compared with children of mothers who had never taken OC [asthma: odds ratio (OR) 1.6; 95% confidence interval (CI): 0.9–3.0; allergic rhinitis: OR 1.5; CI: 0.96–2.2; atopic eczema: OR 2.6; CI: 1.6–4.3; atopic sensitization: OR 1.5; CI: 0.97–2.2]. However, the effect estimates for maternal OC use after birth compared with the never users showed quite similar effects for these atopic conditions. No relations were observed between the prevalences of atopic diseases and maternal age at beginning of OC use, the duration of OC use, the type of contraceptive or maternal age at birth.Conclusion:  This study raises doubts in a true biological association between OC use and atopic diseases.