Neonates colonized in the hypopharyngeal region with S. pneumoniae, H. influenzae, or M. catarrhalis, or with a combination of these organisms, are at increased risk for recurrent wheeze and asthma early in life.
BackgroundLoss-of-function variants in the gene encoding filaggrin (FLG) are major determinants of eczema. We hypothesized that weakening of the physical barrier in FLG-deficient individuals may potentiate the effect of environmental exposures. Therefore, we investigated whether there is an interaction between FLG loss-of-function mutations with environmental exposures (pets and dust mites) in relation to the development of eczema.Methods and FindingsWe used data obtained in early life in a high-risk birth cohort in Denmark and replicated the findings in an unselected birth cohort in the United Kingdom. Primary outcome was age of onset of eczema; environmental exposures included pet ownership and mite and pet allergen levels. In Copenhagen (n = 379), FLG mutation increased the risk of eczema during the first year of life (hazard ratio [HR] 2.26, 95% confidence interval [CI] 1.27–4.00, p = 0.005), with a further increase in risk related to cat exposure at birth amongst children with FLG mutation (HR 11.11, 95% CI 3.79–32.60, p < 0.0001); dog exposure was moderately protective (HR 0.49, 95% CI 0.24–1.01, p = 0.05), but not related to FLG genotype. In Manchester (n = 503) an independent and significant association of the development of eczema by age 12 mo with FLG genotype was confirmed (HR 1.95, 95% CI 1.13–3.36, p = 0.02). In addition, the risk increased because of the interaction of cat ownership at birth and FLG genotype (HR 3.82, 95% CI 1.35–10.81, p = 0.01), with no significant effect of the interaction with dog ownership (HR 0.59, 95% CI 0.16–2.20, p = 0.43). Mite-allergen had no effects in either cohort. The observed effects were independent of sensitisation.ConclusionsWe have demonstrated a significant interaction between FLG loss-of-function main mutations (501x and 2282del4) and cat ownership at birth on the development of early-life eczema in two independent birth cohorts. Our data suggest that cat but not dog ownership substantially increases the risk of eczema within the first year of life in children with FLG loss-of-function variants, but not amongst those without. FLG-deficient individuals may need to avoid cats but not dogs in early life.
Variation at the chromosome 17q12-q21 locus was associated with approximately twofold increased risk of recurrent wheeze, asthma, asthma exacerbations, and bronchial hyperresponsiveness from early infancy to school age but without conferring risk of eczema, rhinitis, or allergic sensitization. These longitudinal clinical data show this locus to be an important genetic determinant of nonatopic asthma in children.
BackgroundDiabetes and TB are associated, and diabetes is increasingly common in low-income countries where tuberculosis (TB) is highly endemic. However, the role of diabetes for TB has not been assessed in populations where HIV is prevalent.MethodsA case-control study was conducted in an urban population in Tanzania among culture-confirmed pulmonary TB patients and non-TB neighbourhood controls. Participants were tested for diabetes according to WHO guidelines and serum concentrations of acute phase reactants were measured. The association between diabetes and TB, and the role of HIV as an effect modifier, were examined using logistic regression. Since blood glucose levels increase during the acute phase response, we adjusted for elevated serum acute phase reactants.ResultsAmong 803 cases and 350 controls the mean (SD) age was 34.8 (11.9) and 33.8 (12.0) years, and the prevalence of diabetes was 16.7% (95% CI: 14.2; 19.4) and 9.4% (6.6; 13.0), respectively. Diabetes was associated with TB (OR 2.2, 95% CI: 1.5; 3.4, p<0.001). However, the association depended on HIV status (interaction, p = 0.01) due to a stronger association among HIV uninfected (OR 4.2, 95% CI: 1.5; 11.6, p = 0.01) compared to HIV infected (OR 0.1, 95% CI: 0.01; 1.8, p = 0.13) after adjusting for age, sex, demographic factors and elevated serum acute phase reactants.ConclusionDiabetes is a risk factor for TB in HIV uninfected, whereas the association in HIV infected patients needs further study. The increasing diabetes prevalence may be a threat to TB control.
The antibacterial properties of the indigenous microflora of rainbow trout (Oncorhynchus mykiss Walbaum) and the potential use of inhibitory bacteria as fish probiotics were investigated. A total of 1018 bacteria and yeasts were isolated on tryptone soy agar (TSA) from skin, gills and intestine. Forty-five of these inhibited growth of the fish pathogenic bacterium Vibrio anguillarum in a well diffusion assay. The antagonism was most prominent among Pseudomonas spp., as 28 (66%) of the antagonistic bacteria belonged to this genus, despite constituting only 15% of the total tested flora. As pseudomonads are typically siderophore producers, chrome azurol S (CAS) agar was used as a semi-selective medium for isolation of antagonistic bacteria. On this medium, 75% of the iron-chelating strains were inhibitory to V. anguillarum. Eight strains out of a subset of 11 antagonists caused a 3-6 log unit reduction in the density of V. anguillarum [measured by polymerase chain reaction (PCR) detection in a most probable number (MPN) regimen] in a broth co-culture assay. Survival of rainbow trout infected with vibriosis was improved 13-43% by six out of nine antagonistic strains tested in vivo. All disease-protecting strains were pseudomonads, isolated from CAS plates, whereas two Carnobacterium spp. that were antagonistic in in vitro well diffusion assays did not alter the accumulated mortality of rainbow trout. The addition of live bacterial cultures to fish-rearing water may thus improve survival of the fish; however, in vitro antagonism could not completely predict an in vivo effect. Further studies on the underlying mechanism of activity are required to design appropriate selection criteria for fish probiotic bacteria.
Summary. Modern epidemiology often requires testing of the effect of a covariate on multiple end points from the same study. However, popular state of the art methods for multiple testing require the tests to be evaluated within the framework of a single model unifying all end points. This severely limits their use in applications where there are different types of end point, e.g. binary, continuous or time to event. We use an asymptotic representation of parameter estimates to combine multiple models without additional constraints. This result enables the use of established tools for multiple testing to provide a fine‐tuned control of the overall type I error in a wide range of epidemiological experiments where in reality no other useful alternative exists. The methodology proposed is applied to a multiple‐end‐point study of the effect of neonatal bacterial colonization on development of childhood asthma.
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