Objectives: Little is known about risk factors for new onset and loss of atopic sensitisation in adulthood. The aim is to examine the longitudinal effect of quantitatively assessed endotoxin exposures on changes in specific allergen sensitisation in young adults.
Methods: The cohort consisted of 1113 young Danish farmers and rural controls, with a mean age of 19 years at baseline.
Background: Childhood exposure to a farm environment has been shown to protect against the development of inflammatory diseases, such as allergy, asthma, and inflammatory bowel disease.
Objective: We sought to investigate whether both exposure to microbes and exposure to structures of nonmicrobial origin, such as the sialic acid N-glycolylneuraminic acid (Neu5Gc), might play a significant role.
Methods: Exposure to Neu5Gc was evaluated by quantifying anti-Neu5Gc antibody levels in sera of children enrolled in 2 farm studies: the Prevention of Allergy Risk factors for Sensitization in Children Related to Farming and Anthroposophic Lifestyle (PARSIFAL) study (n = 299) and the Protection Against Allergy Study in Rural Environments (PASTURE) birth cohort (cord blood [n = 836], 1 year [n = 734], 4.
Importance: Atopic dermatitis is an inflammatory, pruritic skin disease that often occurs in early infancy with a chronic course. However, a specific description of subtypes of atopic dermatitis depending on the timing of onset and progression of the disease in childhood is lacking.
Objective: To identify different phenotypes of atopic dermatitis using a definition based on symptoms before age 6 years and to determine whether some subtypes are more at risk for developing other allergic diseases.
Background: Dampness and mould exposure have been repeatedly associated with respiratory health. However, less is known about the specific agents provoking or arresting health effects in adult populations. We aimed to assess predictors of microbial agents in mattress dust throughout Europe and to investigate associations between microbial exposures, home characteristics and respiratory health.
View Article and Find Full Text PDFBackground: Sensitization to wheat flour plays an important role in the development and diagnosis of baker's asthma.
Objectives: We evaluated wheat allergen components as sensitizers for bakers with work-related complaints, with consideration of cross-reactivity to grass pollen.
Methods: Nineteen recombinant wheat flour proteins and 2 cross-reactive carbohydrate determinants were tested by using CAP-FEIA in sera of 101 bakers with wheat flour allergy (40 German, 37 Dutch, and 24 Spanish) and 29 pollen-sensitized control subjects with wheat-specific IgE but without occupational exposure.
Inverse associations have been found between exposure to bio-contaminants and asthma and allergies. The aim of this study was to prospectively assess whether early exposure to bio-contaminants in dust is associated with asthma and allergy later in childhood among children from (sub)-urban areas. In subsets of three European birth cohorts (PIAMA: n=553; INMA: n=481; and LISAplus: n=395), endotoxin, (1,3,)-β-d-glucan and extracellular polysaccharide were measured in dust from living rooms shortly after birth.
View Article and Find Full Text PDFBackground: Respiratory health effects of damp housing are well recognised, but less is known about the effect of dampness and water damage in schools. The HITEA study previously reported a higher prevalence of respiratory symptoms in pupils from moisture damaged schools, but the role of specific microbial exposures remained unclear.
Objectives: To study associations between school dampness, levels of fungal and bacterial markers, respiratory symptoms and lung function in children.
Objectives: To evaluate sensitization and acute respiratory health effects in inhabitants living in the vicinity of a factory producing soy oil.
Methods: Two panels of potential responders were created on the basis of a response to a short screening questionnaire sent to random samples of 1,000 exposed and 1,000 non-exposed individuals living around the factory and a control area. Individuals responding to the questionnaire were invited for a medical evaluation, including a respiratory symptom questionnaire and skin prick testing, for a panel of common allergens and a soy allergen extract.
Background: Isocyanate asthma is one of the most frequently identified forms of occupational asthma in industrialised countries. The underlying mechanisms have not been clarified. There is only limited information about the relationship between exhaled nitric oxide (eNO) and occupational exposure to isocyanates and asthma.
View Article and Find Full Text PDFBackground: The hygiene hypothesis states that children exposed to higher loads of microbes such as farmers' children suffer less from allergies later in life. Several immunological mechanisms underpinning the hygiene hypothesis have been proposed such as a shift in T helper cell balance, T regulatory cell activity, or immune regulatory mechanisms induced by the innate immunity.
Objective: To investigate whether the proposed immunological mechanisms for the hygiene hypotheses are found in farmers' children.
Both genetic and environmental factors are important for the development of allergic diseases. However, a detailed understanding of how such factors act together is lacking. To elucidate the interplay between genetic and environmental factors in allergic diseases, we used a novel bioinformatics approach that combines feature selection and machine learning.
View Article and Find Full Text PDFRetinoid acid receptor-related Orphan Receptor Alpha (RORA) was recently identified as a susceptibility gene for asthma in a genome-wide association study. To investigate the impact of RORA on asthma susceptibility, we performed a genetic association study between RORA single nucleotide polymorphisms (SNPs) in the vicinity of the asthma-associated SNP (rs11071559) and asthma-related traits. Because the regulatory region of a previously implicated asthma susceptibility gene, Neuropeptide S receptor 1 (NPSR1), has predicted elements for RORA binding, we hypothesized that RORA may interact biologically and genetically with NPSR1.
View Article and Find Full Text PDFExposure to biocontaminants is associated with behavioural problems and poorer cognitive function. Our study assesses the associations between early life exposure to home dampness, pets and farm animal contact and cognitive function and social competences in 4-year old children, and the associations between these indoor factors and microbial compounds (bacterial endotoxin and fungal extracellular polysaccharides). A Spanish population-based birth-cohort enrolled 482 children, and 424 of them underwent psychometric testing at 4 years of age, including the McCarthy Scales of Child Abilities (MSCA) and the California Preschool Social Competence Scale (CPSCS).
View Article and Find Full Text PDFAnn Agric Environ Med
July 2013
Introduction And Objectives: Microbiological control agents (MBCA) are widely used in greenhouses, replacing chemical pesticides. The presented study aims to describe health effects of exposure to three types commonly used: Bacillus thuringiensis, Verticillium lecanii, and Trichoderma harzenianum covering seven different products in greenhouse workers with emphasis on sensitization and respiratory effects.
Methods: 579 persons aged 17-67 years culturing ornamental flowers were included.
β-Glucans are components of fungal cell walls and potent stimulants of innate immunity. The majority of research on biological activities of glucans has focused on β-(1→3)-glucans, which have been implicated in relation to fungal exposure-associated respiratory symptoms and as important stimulatory agents in anti-fungal immune responses. Fungi-and bacteria and plants-produce a wide variety of glucans with vast differences in the proportion and arrangement of their β-(1→3)-, -(1→4)- and -(1→6)-glycosidic linkages.
View Article and Find Full Text PDFInt Arch Occup Environ Health
February 2013
Purpose: Despite the importance of skin exposure, studies of skin symptoms in relation to exposure and respiratory symptoms are rare. The goals of this study were to describe exposure-response relationships for skin symptoms, and to investigate associations between skin and respiratory symptoms in bakery and auto body shop workers.
Methods: Data from previous studies of bakery and auto body shop workers were analyzed.
Background: Fungal β-(1,3)-glucans are pro-inflammatory agents, and exposures to β-(1,3)-glucans are associated with respiratory tract symptoms. IgG anti-(1,3)-glucan titers are measured in diagnosis of fungal infections. Although other β-glucan structures exist, like β-(1,6)-glucans, little is known about their antigenic or pro-inflammatory properties.
View Article and Find Full Text PDFObjectives: Endotoxin-exposed workers are at an increased risk of non-atopic asthma and lung-function decline. Genetic variants may influence susceptibility to these effects. The objective of the present study was to assess whether the association between occupational endotoxin exposure and wheeze is modified by innate immunity gene variants.
View Article and Find Full Text PDFBackground: Based on a recent positional cloning approach, it was claimed that the collagen 29A1 gene (COL29A1), which encodes an epidermal collagen, represents a major risk gene for eczema underlying a previously reported linkage to chromosome 3q21. However, thus far, not a single replication attempt has been published, and no definitive functional data have been provided.
Objectives: We aimed to determine whether COL29A1 polymorphisms contribute to eczema susceptibility and whether COL29A1 expression is altered in eczema.
We recently introduced a passive dust sampling method for airborne endotoxin and glucan exposure assessment-the electrostatic dustfall collector (EDC). In this study, we assessed the effects of different storage and extraction procedures on measured endotoxin and glucan levels, using 12 parallel EDC samples from 10 low exposed indoor environments. Additionally, we compared 2- and 4-week sampling with the prospect of reaching higher dust yields.
View Article and Find Full Text PDFAssociations between house dust-associated beta-(1,3)-glucan exposure and airway inflammatory reactions have been reported, while such exposures in early childhood have been suggested to protect against asthma and wheezing. Most epidemiological studies have used reservoir dust samples and an inhibition enzyme immunoassay (EIA) for beta-(1,3)-glucan exposure assessment. The objective of this study was to develop inexpensive but highly sensitive enzyme immunoassays to measure airborne beta-(1,3)-glucans in low-exposure environments, like homes.
View Article and Find Full Text PDFBackground: Microbial exposures in both childhood and adult life are protective against atopy, allergic rhinitis and atopic asthma. In adults, this protective effect is paralleled by an increased prevalence of non-atopic asthma. This study was undertaken to investigate associations between occupational endotoxin exposure and atopic sensitization and bronchial hyperresponsiveness to methacholine (BHR) in agricultural workers.
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