104 research outputs found
Topical Corticosteroids Normalize both Skin and Systemic Inflammatory Markers in Infant Atopic Dermatitis
Background: Atopic dermatitis (AD) is the most common inflammatory skin disease. It is highly heterogeneous in clinical presentation, treatment response, disease trajectory and associated atopic comorbidities. Immune biomarkers are dysregulated in skin and peripheral blood. Aims: We used noninvasive skin and peripheral biomarkers to observe the effects of real-world topical corticosteroid (TCS) treatment in infants with AD, by measuring skin and blood biomarkers before and after therapy. Methods: Seventy-four treatment-naïve infants with AD underwent 6 weeks of TCS treatment. Stratum corneum (SC) and plasma blood biomarkers as well as SC natural moisturizing factor (NMF) were measured before and after TCS therapy. Immune markers included innate, T helper (Th)1 and Th2 immunity, angiogenesis, and vascular factors. AD severity was assessed by the Scoring Atopic Dermatitis index, and skin barrier function by transepidermal water loss (TEWL). Twenty healthy infants were recruited as controls. Results: TCS therapy predictably led to improvement in disease severity. Levels of immune markers in the skin and in the peripheral blood showed significant change from baseline, though most did not reach healthy control levels. The most prominent change from baseline in the SC was in markers of innate immune activation, interleukin (IL)-18, IL-8 and IL-1α, and the Th2 chemokines C-C motif chemokine (CCL)17 and CCL22. In blood, the largest changes were in Th2-skewed biomarkers: CCL17, IL-13, CCL22, IL-5, and CCL26. TEWL decreased after therapy; no significant changes from baseline were found for NMF. Conclusions: The profound impact of topical therapy on systemic biomarkers suggests that the skin compartment generates a major component of dysregulated systemic cytokines in infant AD. There may be long-term beneficial effects of correcting systemic immune dysregulation through topical therapy
Preconcentration techniques for trace explosive sensing
This project has received funding from NATO Science for Peace & Security under grant agreement MYP G5355, the European Union’s Seventh Framework Programme for research, technological development and demonstration under agreement no 284747, and the EPSRC under EP/K503940/1.Trace sensing of explosive vapours is a method in humanitarian demining and Improvised Explosives Device (IED) detection that has received increasing attention recently, since accurate, fast, and reliable chemical detection is highly important for threat identification. However, trace molecule sampling in the field can be extremely difficult due to factors including weather, locale, and very low vapour pressure of the explosive. Preconcentration of target molecules onto a substrate can provide a method to collect higher amounts of analyte for analysis. We used the commercial fluoropolymer Aflas as a preconcentrator material to sorb explosive molecules to the surface, allowing subsequent detection of the explosives via the luminescence quenching response from the organic polymer Super Yellow. The preconcentration effect of Aflas was confirmed and characterised with 2,4-DNT, prior to field sampling being conducted at a test minefield in Croatia by placing preconcentration strips in the entrance of the hives, where honeybees have collected explosive materials during free-flying. In this work we show for the first time a method for confirmation of landmines combining honeybee colonies containing a preconcentration material and subsequent monitoring of luminescence quenching.PostprintPeer reviewe
Randomized controlled pilot trial with ion‐exchange water softeners to prevent eczema (SOFTER trial)
Background
Observational studies suggest an increased risk of eczema in children living in hard versus soft water areas, and there is, therefore, an interest in knowing whether softening water may prevent eczema. We evaluated the feasibility of a parallel-group assessor-blinded pilot randomized controlled trial to test whether installing a domestic ion-exchange water softener before birth in hard water areas reduces the risk of eczema in infants with a family history of atopy.
Methods
Pregnant women living in hard water areas (>250 mg/L calcium carbonate) in and around London UK, were randomized 1:1 antenatally to either have an ion-exchange water softener installed in their home or not (ie to continue to receive usual domestic hard water). Infants were assessed at birth and followed up for 6 months. The main end-points were around feasibility, the primary end-point being the proportion of eligible families screened who were willing and able to be randomized. Clinical end-points were evaluated including frequency of parent-reported doctor-diagnosed eczema and visible eczema on skin examination. Descriptive analyses were conducted, and no statistical testing was performed as this was a pilot study.
Results
One hundred and forty-nine families screened were eligible antenatally and 28% (41/149) could not have a water softener installed due to technical reasons or lack of landlord approval. Eighty of 149 (54%) were randomized, the primary end-point. Two participants withdrew immediately after randomization, leaving 39 participants in each arm (78 total). Attrition was 15% (12/78) by 6 months postpartum. All respondents (n = 69) to the study acceptability questionnaire reported that the study was acceptable. Fifty-six of 708 (7.9%) water samples in the water softener arm were above the hard water threshold of 20 mg/L CaCO3. At 6 months of age 27/67 infants (40%) developed visible eczema, 12/36 (33%) vs. 15/31 (48%) in the water softener and control groups, respectively, difference −15% (95% CI −38, 8.3%), with most assessments (≥96%) remaining blinded. Similarly, a lower proportion of infants in the water softener arm had parent-reported, doctor-diagnosed eczema by 6 months compared to the control arm, 6/17 (35%) versus 9/19 (47%), difference −12% (95% CI −44, 20%).
Conclusion
A randomized controlled trial of water softeners for the prevention of atopic eczema in high-risk infants is feasible and acceptable
Protocol for an outcome assessor-blinded pilot randomised controlled trial of an ion-exchange water softener for the prevention of atopic eczema in neonates, with an embedded mechanistic study : the softened water for eczema prevention (SOFTER) trial
Introduction
Atopic eczema affects 20% of UK children, and environmental factors are important in its aetiology. Several observational studies suggest an increased risk of atopic eczema in children living in hard water areas. The Softened Water for Eczema Prevention pilot trial tests the feasibility of installing domestic ion-exchange water softeners around the time of birth to reduce the risk of atopic eczema in children with a family history of atopy. A further aim is to explore the pathophysiological mechanisms for this in an embedded mechanistic study.
Methods and analysis
Multicentre parallel group assessor-blinded randomised controlled pilot trial. Participants are newborn babies (n=80) living in a hard water (>250 mg/L calcium carbonate) area at risk of developing atopic eczema because of a family history of atopy. Participants will be randomised prior to birth in a 1:1 ratio. The intervention group will have an ion-exchange water softener installed prior to birth. The control group will receive their usual domestic hard water supply. Follow-up will be until 6 months of age. Data will be collected at birth (baseline), 1, 3 and 6 months of age. The main outcome is the proportion of eligible families screened who are willing and able to be randomised. Several secondary feasibility and clinical endpoints will also be evaluated, alongside mechanistic outcomes. Data will be analysed on an intention-to-treat basis. There will be no hypothesis testing for the clinical outcomes. Study acceptability will be evaluated through semistructured interviews.
Ethics and dissemination
This study has been reviewed and given a favourable opinion by the North West–Liverpool East Research Ethics Committee (Ref: 17/NW/0661). The results of the study will be reported at international conferences and in peer-reviewed scientific journals. We will send participating families a summary of the pilot trial results
Filaggrin Genotype Determines Functional and Molecular Alterations in Skin of Patients with Atopic Dermatitis and Ichthyosis Vulgaris
BACKGROUND: Several common genetic and environmental disease mechanisms are important for the pathophysiology behind atopic dermatitis (AD). Filaggrin (FLG) loss-of-function is of great significance for barrier impairment in AD and ichthyosis vulgaris (IV), which is commonly associated with AD. The molecular background is, however, complex and various clusters of genes are altered, including inflammatory and epidermal-differentiation genes. OBJECTIVE: The objective was to study whether the functional and molecular alterations in AD and IV skin depend directly on FLG loss-of-function, and whether FLG genotype determines the type of downstream molecular pathway affected. METHODS AND FINDINGS: Patients with AD/IV (n = 43) and controls (n = 15) were recruited from two Swedish outpatient clinics and a Swedish AD family material with known FLG genotype. They were clinically examined and their medical history recorded using a standardized questionnaire. Blood samples and punch biopsies were taken and trans-epidermal water loss (TEWL) and skin pH was assessed with standard techniques. In addition to FLG genotyping, the STS gene was analyzed to exclude X-linked recessive ichthyosis (XLI). Microarrays and quantitative real-time PCR were used to compare differences in gene expression depending on FLG genotype. Several different signalling pathways were altered depending on FLG genotype in patients suffering from AD or AD/IV. Disease severity, TEWL and pH follow FLG deficiency in the skin; and the number of altered genes and pathways are correlated to FLG mRNA expression. CONCLUSIONS: We emphasize further the role of FLG in skin-barrier integrity and the complex compensatory activation of signalling pathways. This involves inflammation, epidermal differentiation, lipid metabolism, cell signalling and adhesion in response to FLG-dependent skin-barrier dysfunction
Ecologically Appropriate Xenobiotics Induce Cytochrome P450s in Apis mellifera
BACKGROUND: Honey bees are exposed to phytochemicals through the nectar, pollen and propolis consumed to sustain the colony. They may also encounter mycotoxins produced by Aspergillus fungi infesting pollen in beebread. Moreover, bees are exposed to agricultural pesticides, particularly in-hive acaricides used against the parasite Varroa destructor. They cope with these and other xenobiotics primarily through enzymatic detoxificative processes, but the regulation of detoxificative enzymes in honey bees remains largely unexplored. METHODOLOGY/PRINCIPAL FINDINGS: We used several approaches to ascertain effects of dietary toxins on bee susceptibility to synthetic and natural xenobiotics, including the acaricide tau-fluvalinate, the agricultural pesticide imidacloprid, and the naturally occurring mycotoxin aflatoxin. We administered potential inducers of cytochrome P450 enzymes, the principal biochemical system for Phase 1 detoxification in insects, to investigate how detoxification is regulated. The drug phenobarbital induces P450s in many insects, yet feeding bees with phenobarbital had no effect on the toxicity of tau-fluvalinate, a pesticide known to be detoxified by bee P450s. Similarly, no P450 induction, as measured by tau-fluvalinate tolerance, occurred in bees fed xanthotoxin, salicylic acid, or indole-3-carbinol, all of which induce P450s in other insects. Only quercetin, a common pollen and honey constituent, reduced tau-fluvalinate toxicity. In microarray comparisons no change in detoxificative gene expression was detected in phenobarbital-treated bees. However, northern blot analyses of guts of bees fed extracts of honey, pollen and propolis showed elevated expression of three CYP6AS P450 genes. Diet did not influence tau-fluvalinate or imidacloprid toxicity in bioassays; however, aflatoxin toxicity was higher in bees consuming sucrose or high-fructose corn syrup than in bees consuming honey. CONCLUSIONS/SIGNIFICANCE: These results suggest that regulation of honey bee P450s is tuned to chemicals occurring naturally in the hive environment and that, in terms of toxicological capacity, a diet of sugar is not equivalent to a diet of honey
Stimuli Thresholds for Isomerization-Induced Molecular Motions in Azobenzene-Containing Materials.
We use large-scale molecular dynamics simulations of the isomerizations of azobenzene molecules diluted inside a simple molecular material to investigate the effect of a modification of the cis isomer shape on the induced diffusion mechanism. To this end we simulate incomplete isomerizations, modifying the amplitude of the trans-to-cis isomerization. We find thresholds in the evolution of the host molecules mobility with the isomerization amplitude, a result predicted by the cage-breaking mechanism hypothesis (Teboul, V.; Saiddine, M.; Nunzi, J. M.; Accary, J. B. J. Chem. Phys. 2011, 134, 114517) and by the gradient pressure mechanism theory (Barrett, C. J.; Rochon, P. L.; Natansohn, A. L. J. Chem. Phys. 1998, 109, 1505–1516.). Above the threshold the diffusion then increases linearly with the variation of the chromophore size induced by the isomerization
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