Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 26
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Clin Exp Dermatol ; 2024 May 15.
Article in English | MEDLINE | ID: mdl-38747172

ABSTRACT

Acne vulgaris (AV) is the eighth most common non-fatal disease globally. Previous work identified an association between AV and increased Filaggrin (FLG) expression in the follicular epidermis, but further work did not find a clear link between loss of function (LoF) Filaggrin gene (FLG) mutations and protection from AV. In this work we aimed to explore any association between AV and FLG LoF mutations using a cohort of genotyped Bangladeshi patients with atopic eczema (AE) in East London. Retrospective notes review was performed on 245 patients who had been genotyped for FLG LoF mutations and undergone clinical assessment. The Chi squared or Fisher's exact test was used to determine differences between groups. We found a significant reduction in history of AV in AE patients with FLG LoF mutations relative to AE patients without FLG mutations (p = 0.02). We showed a non-significant reduction in AV diagnosis in patients with impaired barrier function (measured by trans epidermal water loss) and palmar hyperlinearity. We found that patients with severe AE were less likely to have a history of AV only if they had an existing FLG LoF mutation (p = 0.02). In the context of AE, our work suggests that FLG LoF mutations protect patients from developing AV.

2.
Br J Dermatol ; 188(4): 524-532, 2023 03 30.
Article in English | MEDLINE | ID: mdl-36745558

ABSTRACT

BACKGROUND: Atopic eczema (AE) is a chronic relapsing, pruritic disease that greatly affects the child and family's quality of life (QoL). It is usually common and severe among children of Bangladeshi ethnicity. OBJECTIVES: This is a cross-sectional quantitative study in patients with AE of Bangladeshi origin, which aims to analyse different components of the family, children and adult quality-of-life indices and their relationship to patient age, sex, eczema severity and distribution, other allergic associations, parental education and socioeconomic level. METHODS: Children and young adults of Bangladeshi origin aged 0-30 years, clinically diagnosed with AE were recruited as part of the Tower Hamlets Eczema Assessment project, a clinical phenotyping study of AE in the Bangladeshi population living in East London. Questionnaires completed by children/parents included the Family Dermatology Life Quality Index (FDLQI), Infant's Dermatology Quality of Life (IDQOL) and the Children's Dermatology Life Quality Index (CDLQI). Young adults completed the Dermatology Life Quality Index (DLQI). The disease severity was assessed objectively using the Eczema Area Severity Index (EASI). Patients and parents who did not read or speak English were aided by Bengali/Sylheti-speaking research assistants. RESULTS: Overall, 460 Bangladeshi children and 98 adults with AE were recruited. Burden of care, extra housework and emotional distress were the highest affected domains in parental QoL, while itching and sleep were the highest for children. Significant factors influencing FDLQI score were EASI [marginal effect (ME) 1.01, 95% confidence interval (CI) 1.00-1.03; P = 0.004], age (ME 0.98, 95% CI 0.97-0.99; P = 0.004), extensor eczema distribution (ME 1.25, 95% CI 1.03-1.52; P = 0.023), parental English fluency (ME 1.29, 95% CI 1.10-1.52; P = 0.002) and atopic comorbidities (ME 1.10, 95% CI 1.04-1.17; P = 0.001). Parental socioeconomic class was a nonsignificant factor. IDQOL/CDLQI was influenced significantly by the child's age (ME 0.99, 95% CI 0.97-1.00, P = 0.023), 'nonclear' eczema distribution clusters especially the 'severe extensive' cluster (ME 1.46, 95% CI 1.15-1.84; P = 0.002) and nonsignificantly by EASI and parental English literacy and socioeconomic levels. DLQI was affected significantly by nonclear eczema distribution groups especially 'severe extensive' (ME 2.49, 95% 1.76-3.53; P < 0.001) and nonsignificantly by patient age, and female sex. CONCLUSIONS: AE is a chronic disease where many external factors other than disease severity affect QoL of patients and their families, -especially in under-represented minority groups who face different linguistic and cultural barriers.


Subject(s)
Dermatitis, Atopic , Dermatology , Eczema , Child , Infant , Young Adult , Humans , Female , Dermatitis, Atopic/psychology , Quality of Life , Cross-Sectional Studies , London/epidemiology , Severity of Illness Index , Pruritus
3.
Br J Dermatol ; 188(6): 785-792, 2023 05 24.
Article in English | MEDLINE | ID: mdl-36840480

ABSTRACT

BACKGROUND: Hyperlinear palms are described as a feature of loss-of-function (LoF) variants in filaggrin (FLG). OBJECTIVES: To explore the phenotype of participants (age < 31 years) with atopic eczema of Bangladeshi ancestry from East London and investigate which factors best associate with LoF FLG variants. METHODS: A cross-sectional study with participants recruited between May 2018 and December 2020. Patterns of palmar linearity were categorized and modelled with the Eczema Area and Severity Index (EASI), transepidermal water loss (TEWL), skin hydration (SH) and LoF FLG variants. RESULTS: There were 506 complete cases available. Five palm patterns were noted. The 'prominent diamond' pattern associated best with EASI [marginal effects (ME) 2.53, 95% confidence interval (CI) 1.74-3.67], SH (ME 0.85, 95% CI 0.78-0.96) and TEWL (ME 1.32, 95% CI 1.11-1.62). Using five palm patterns had some ability to discriminate LoF FLG variants [area under the receiver operator characteristic (AUROC) 76.32%, 95% CI 71.91-80.73], improving to 77.99% (73.70-82.28) with the addition of SH. In subgroup analysis with only fine perpendicular/prominent diamond patterns the AUROC was 89.11% (95% CI 84.02-94.19). CONCLUSIONS: This was a single-centre study design with humans classifying clinical patterns. The stability of temperature and humidity was not guaranteed across TEWL and SH measurements despite using a climate-controlled room. Palm patterns associate with EASI and TEWL. The fine perpendicular/prominent diamond patterns are markers to detect the absence/presence of LoF FLG variants, respectively.


Subject(s)
Dermatitis, Atopic , Eczema , Humans , Adult , Dermatitis, Atopic/genetics , Filaggrin Proteins , Cross-Sectional Studies , Eczema/genetics , Patient Acuity , Intermediate Filament Proteins/genetics , Intermediate Filament Proteins/metabolism , Mutation/genetics , Genetic Predisposition to Disease/genetics
4.
Br J Dermatol ; 189(6): 674-684, 2023 11 16.
Article in English | MEDLINE | ID: mdl-37722926

ABSTRACT

BACKGROUND: Conventional systemic drugs are used to treat children and young people (CYP) with severe atopic dermatitis (AD) worldwide, but no robust randomized controlled trial (RCT) evidence exists regarding their efficacy and safety in this population. While novel therapies have expanded therapeutic options, their high cost means traditional agents remain important, especially in lower-resource settings. OBJECTIVES: To compare the safety and efficacy of ciclosporin (CyA) with methotrexate (MTX) in CYP with severe AD in the TREatment of severe Atopic Eczema Trial (TREAT) trial. METHODS: We conducted a parallel group assessor-blinded RCT in 13 UK and Irish centres. Eligible participants aged 2-16 years and unresponsive to potent topical treatment were randomized to either oral CyA (4 mg kg-1 daily) or MTX (0.4 mg kg-1 weekly) for 36 weeks and followed-up for 24 weeks. Co-primary outcomes were change from baseline to 12 weeks in Objective Severity Scoring of Atopic Dermatitis (o-SCORAD) and time to first significant flare (relapse) after treatment cessation. Secondary outcomes included change in quality of life (QoL) from baseline to 60 weeks; number of participant-reported flares following treatment cessation; proportion of participants achieving ≥ 50% improvement in Eczema Area and Severity Index (EASI 50) and ≥ 75% improvement in EASI (EASI 75); and stratification of outcomes by filaggrin status. RESULTS: In total, 103 participants were randomized (May 2016-February 2019): 52 to CyA and 51 to MTX. CyA showed greater improvement in disease severity by 12 weeks [mean difference in o-SCORAD -5.69, 97.5% confidence interval (CI) -10.81 to -0.57 (P = 0.01)]. More participants achieved ≥ 50% improvement in o-SCORAD (o-SCORAD 50) at 12 weeks in the CyA arm vs. the MTX arm [odds ratio (OR) 2.60, 95% CI 1.23-5.49; P = 0.01]. By 60 weeks MTX was superior (OR 0.33, 95% CI 0.13-0.85; P = 0.02), a trend also seen for ≥ 75% improvement in o-SCORAD (o-SCORAD 75), EASI 50 and EASI 75. Participant-reported flares post-treatment were higher in the CyA arm (OR 3.22, 95% CI 0.42-6.01; P = 0.02). QoL improved with both treatments and was sustained after treatment cessation. Filaggrin status did not affect outcomes. The frequency of adverse events (AEs) was comparable between both treatments. Five (10%) participants on CyA and seven (14%) on MTX experienced a serious AE. CONCLUSIONS: Both CyA and MTX proved effective in CYP with severe AD over 36 weeks. Participants who received CyA showed a more rapid response to treatment, while MTX induced more sustained disease control after discontinuation.


Subject(s)
Cyclosporine , Dermatitis, Atopic , Child , Humans , Adolescent , Cyclosporine/adverse effects , Methotrexate/adverse effects , Dermatitis, Atopic/drug therapy , Filaggrin Proteins , Odds Ratio , Treatment Outcome , Severity of Illness Index , Double-Blind Method
5.
Angew Chem Int Ed Engl ; 62(45): e202311044, 2023 Nov 06.
Article in English | MEDLINE | ID: mdl-37718313

ABSTRACT

We report thermochromism in crystals of diphenyl diselenide (dpdSe) and diphenyl ditelluride (dpdTe), which is at variance with the commonly known mechanisms of thermochromism in molecular crystals. Variable temperature neutron diffraction studies indicated no conformational change, tautomerization or phase transition between 100 K and 295 K. High-pressure crystallography studies indicated no associated piezochromism in dpdSe and dpdTe crystals. The evolution of the crystal structures and their electronic band structure with pressure and temperature reveal the contributions of intramolecular and intermolecular factors towards the origin of thermochromism-especially the intermolecular Se⋅⋅⋅Se and Te⋅⋅⋅Te chalcogen bonds and torsional modes of vibrations around the dynamic Se-Se and Te-Te bonds. Further, a co-crystal of dpdSe with iodine (dpdSe-I2 ) and an alloy crystal of dpdSe and dpdTe implied a predominantly intramolecular origin of the observed thermochromism associated with vibronic coupling.

6.
Angew Chem Int Ed Engl ; 61(22): e202202742, 2022 May 23.
Article in English | MEDLINE | ID: mdl-35286738

ABSTRACT

Glass-forming metal-organic frameworks (MOFs) have novel applications, but the origin of their peculiar melting behavior is unclear. Here, we report synchrotron X-ray diffraction electron densities of two zeolitic imidazolate frameworks (ZIFs), the glass-forming Zn-ZIF-zni and the isostructural thermally decomposing Co-ZIF-zni. Electron density analysis shows that the Zn-N bonds are more ionic than the Co-N bonds, which have distinct covalent features. Variable-temperature Raman spectra reveal the onset of significant imidazolate bond weakening in Co-ZIF-zni above 673 K. Melting can be controlled by tuning the metal-ligand and imidazole bonding strength as shown from thermal analysis of nine solid-solution Cox Zn1-x -ZIF-zni (x=0.3 to 0.003) MOFs, and a mere 4 % Co-doping into Zn-ZIF-zni results in thermal decomposition instead of melting. The present findings demonstrate the key role of the metal-ligand bonds and imidazolate bonds in controlling the delicate balance between melting and decomposition processes in this class of ZIF compounds.

7.
Chemistry ; 26(39): 8651-8662, 2020 Jul 14.
Article in English | MEDLINE | ID: mdl-32297999

ABSTRACT

FeSb2 exhibits a colossal Seebeck coefficient ( S ) and a record-breaking high thermoelectric power factor. It also has an atypical shift from diamagnetism to paramagnetism with increasing temperature, and the fine details of its electron correlation effects have been widely discussed. The extraordinary physical properties must be rooted in the nature of the chemical bonding, and indeed, the chemical bonding in this archetypical marcasite structure has been heavily debated on a theoretical basis since the 1960s. The two prevalent models for describing the bonding interactions in FeSb2 are based on either ligand-field stabilization of Fe or a network structure of Sb hosting Fe ions. However, neither model can account for the observed properties of FeSb2 . Herein, an experimental electron density study is reported, which is based on analysis of synchrotron X-ray diffraction data measured at 15 K on a minute single crystal to limit systematic errors. The analysis is supplemented with density functional theory calculations in the experimental geometry. The experimental data are at variance with both the additional single-electron Sb-Sb bond implied by the covalent model, and the large formal charge and expected d-orbital splitting advocated by the ionic model. The structure is best described as an extended covalent network in agreement with expectations based on electronegativity differences.

8.
Acta Derm Venereol ; 100(7): adv00094, 2020 Mar 25.
Article in English | MEDLINE | ID: mdl-32147745

ABSTRACT

Inherited monogenic palmoplantar keratodermas are a heterogeneous group of conditions characterised by persistent epidermal thickening of the palmoplantar skin. Palmoplantar keratodermas are grouped depending on the morphology of the keratoderma into diffuse, focal/striate or papular/punctate. Some palmoplantar keratodermas just affect the skin of the palms and soles and others have associated syndromic features which include changes in hair, teeth, nails, hearing loss or cardiomyopathy. Next generation sequencing has helped discover genes involved in many of these conditions and has led to reclassification of some palmoplantar keratodermas. In this review, we discuss the diagnostic features of palmoplantar keratodermas and management options.


Subject(s)
Keratoderma, Palmoplantar/diagnosis , Keratoderma, Palmoplantar/genetics , Humans , Keratoderma, Palmoplantar/therapy , Keratoderma, Palmoplantar, Epidermolytic/diagnosis , Keratoderma, Palmoplantar, Epidermolytic/genetics , Keratoderma, Palmoplantar, Epidermolytic/therapy , Mutation , Phenotype
13.
Clin Infect Dis ; 73(11): e3982-e3983, 2021 12 06.
Article in English | MEDLINE | ID: mdl-32780852
14.
Contact Dermatitis ; 71(2): 98-101, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24850439

ABSTRACT

BACKGROUND: Hair dye exposure is the most common cause of sensitization to p-phenylenediamine (PPD). Cross-reactions with structurally related allergens occur. OBJECTIVES: It is suggested that a stronger patch test reaction (3+ rather than 1+) to PPD (usually tested as 1% petrolatum) is associated with an increased propensity for cross-reactions. In this article we will demonstrate this association. METHODS: Of 230 patients with allergic reactions to PPD on patch testing identified during 2007-2012 from clinical records, notes for 221 were available for review. Data were collected regarding age, sex, and grade of reaction [International Contact Dermatitis Research Group (ICDRG) criteria] to PPD. Cross-reactions with the following allergens, found in our baseline series, were recorded: Disperse Yellow 3, N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), and caine mix. Having excluded 23 doubtful reactions, the reactions from 198 patients were further considered. RESULTS: Of the patients, 75.3% (n = 149) were female, and the mean age was 48.6 years (12-82 years). Of the patients allergic to PPD, 16.6% (n = 33) showed cross-reactions with one or more related allergens. Cross-reactions were seen in 16% with a grade of 1+, 14.5% with a grade of 2+, 28.6% with a grade of 3+ when PPD was tested 1% pet., and 50.0% when PPD was tested at 0.1-0.001%, arbitrarily considered to be 4+ (p = 0.02; Cramér's V = 0.23). CONCLUSION: An increasing likelihood of reactions to Disperse Yellow 3, IPPD or caine mix was seen with increasing strength of patch test reaction to PPD. The clinical relevance of these cross-reactions is unclear.


Subject(s)
Anesthetics, Local/immunology , Azo Compounds/immunology , Dermatitis, Allergic Contact/immunology , Hair Dyes/chemistry , Phenylenediamines/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Cross Reactions , Dermatitis, Allergic Contact/etiology , Female , Hair Dyes/adverse effects , Humans , Male , Middle Aged , Patch Tests , Retrospective Studies , Young Adult
16.
Skin Health Dis ; 4(3): e358, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38846698

ABSTRACT

Background: Atopic eczema is a common, chronic, inflammatory skin condition with considerable heterogeneity. South Asian people living in the UK frequently have low serum vitamin D3 (25(OH)D3), and those with atopic disease can present with severe eczema. The association between vitamin D deficiency and eczema severity, and the role of vitamin D supplementation in atopic eczema is inconsistent, and under-researched in people with Asian ancestry. Objectives: This cross-sectional study investigates the association between serum 25(OH)D3 and eczema severity in a cohort of South Asian children and young adults living in London. Methods: Eligible participants were Bangladeshi children and young adults aged 0-30 years with eczema, living in London and participating in the Tower Hamlets Eczema Assessment study. Data was collected via parent/patient self-reporting, clinical history and examination, and hospital databases. 25(OH)D3 levels were documented retrospectively, if available, from hospital databases. Eczema severity was classified by Eczema Area and Severity Index (EASI) score less than or greater than 10 (clear-mild vs. moderate-severe). Multivariate logistic regression was used to adjust for confounding factors. Results: 681 participants were included in analyses. 25(OH)D3 results were available for 49.6% (338/681), 84.3% of which had deficient or insufficient lowest 25(OH)D3. Lowest 25(OH)D3 was inversely correlated with EASI score (Spearman's rank R 2 = -0.24, p < 0.001). 26.1% (178/681) had EASI >10 and a lower median lowest and nearest 25(OH)D3. After adjustment for confounding EASI > 10 was significantly associated with a lowest 25(OH)D3 < 25 (OR 3.21, 95%CI 1.35, 8.60), use of mild-moderate potency topical steroid on the face and neck (OR 3.11, 95%CI 1.86, 5.31), calcineurin inhibitor on the face and neck (OR 2.79, 95% CI 1.26, 6.10) and potent - very potent topical steroid on the face and neck (OR2.23, 95%CI 1.02, 4.77) and body (OR 2.11, 95%CI 1.18, 3.87). Discussion: Vitamin D plays a role in modulation of proteins required for skin barrier function and regulation of the innate immune system, suggesting 25(OH)D3 deficiency contributes to skin inflammation. This study demonstrates a relationship between 25(OH)D3 deficiency and worse eczema severity in a cohort of South Asian children and young adults.

17.
Acta Crystallogr A Found Adv ; 79(Pt 1): 41-50, 2023 Jan 01.
Article in English | MEDLINE | ID: mdl-36601762

ABSTRACT

The electron density and thermal motion of diamond are determined at nine temperatures between 100 K and 1000 K via synchrotron powder X-ray diffraction (PXRD) data collected on a high-accuracy detector system. Decoupling of the thermal motion from the thermally smeared electron density is performed via an iterative Wilson-Hansen-Coppens-Rietveld procedure using theoretical static structure factors from density functional theory (DFT) calculations. The thermal motion is found to be harmonic and isotropic in the explored temperature range, and excellent agreement is observed between experimental atomic displacement parameters (ADPs) and those obtained via theoretical harmonic phonon calculations (HPC), even at 1000 K. The Debye temperature of diamond is determined experimentally to be ΘD = 1883 (35) K. A topological analysis of the electron density explores the temperature dependency of the electron density at the bond critical point. The properties are found to be constant throughout the temperature range. The robustness of the electron density confirms the validity of the crystallographic convolution approximation for diamond in the explored temperature range.

18.
Adv Mater ; 35(5): e2207152, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36418017

ABSTRACT

Magnetic materials with the spinel structure (A2+ B3+ 2 O4 ) form the core of numerous magnetic devices, and ZnFe2 O4 constitutes a peculiar example where the nature of the magnetism is still unresolved. Susceptibility measurements revealed a cusp around Tc  = 13 K resembling an antiferromagnetic transition, despite the positive Curie-Weiss temperature determined to be ΘCW  = 102.8(1) K. Bifurcation of field-cooled and zero-field-cooled data below Tc in conjunction with a frequency dependence of the peak position and a non-zero imaginary component below Tc shows it is in fact associated with a spin-glass transition. Highly structured magnetic diffuse neutron scattering from single crystals develops between 50 K and 25 K revealing the presence of magnetic disorder which is correlated in nature. Here, the 3D-mΔPDF method is used to visualize the local magnetic ordering preferences, and ferromagnetic nearest-neighbor and antiferromagnetic third nearest-neighbor correlations are shown to be dominant. Their temperature dependence is extraordinary with some flipping in sign and a strongly varying correlation length. The correlations can be explained by orbital interaction mechanisms for the magnetic pathways and a preferred spin cluster. This study demonstrates the power of the 3D-mΔPDF method in visualizing complex quantum phenomena thereby providing a way to obtain an atomic-scale understanding of magnetic frustration.

19.
Skin Therapy Lett ; 17(10): 5-9, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23223768

ABSTRACT

Cutaneous T-cell lymphomas are rare, distinct forms of non-Hodgkin's lymphomas. Of which, mycosis fungoides (MF) and Sézary syndrome (SS) are two of the most common forms. Careful, clear classification and staging of these lymphomas allow dermatologists to commence appropriate therapy and allow correct prognostic stratification for those patients affected. Of note, patients with more advanced disease will require multi-disciplinary input in determining specialist therapy. Literature has been summarized into an outline for classification/staging of MF and SS with the aim to provide clinical dermatologists with a concise review.


Subject(s)
Mycosis Fungoides/classification , Sezary Syndrome/classification , Skin Neoplasms/classification , Humans , Mycosis Fungoides/pathology , Mycosis Fungoides/therapy , Neoplasm Staging/methods , Prognosis , Sezary Syndrome/pathology , Sezary Syndrome/therapy , Skin Neoplasms/pathology , Skin Neoplasms/therapy
20.
IUCrJ ; 9(Pt 4): 523-532, 2022 Jul 01.
Article in English | MEDLINE | ID: mdl-35844472

ABSTRACT

The scattering pattern of a crystal obeys the symmetry of the crystal structure through the corresponding Laue group. This is usually also true for the diffuse scattering, containing information about disorder, but here a case is reported where the diffuse scattering is of lower symmetry than the parent crystal structure. The mineral bixbyite has been studied by X-ray and neutron scattering techniques since 1928 with some of the most recent studies characterizing the low-temperature transition to a magnetically disordered spin-glass state. However, bixbyite also exhibits structural disorder, and here single-crystal X-ray and neutron scattering is used to characterize the different modes of disorder present. One-dimensional rods of diffuse scattering are observed in the cubic mineral bixbyite, which break the expected symmetry of the scattering pattern. It is shown that this scattering arises from epitaxial intergrowths of the related mineral, braunite. The presence of this disorder mode is found to be directly observable as well-defined residuals in the average structure refined against the Bragg diffraction. An additional three-dimensional diffuse scattering component is observed in neutron scattering data, which is shown to originate from the substitutional disorder on the Fe/Mn sites. This occupational disorder gives rise to local relaxations of the oxide sublattice, and the pattern of oxide displacements can be rationalized based on crystal-field theory. The combined use of neutron and X-ray single-crystal scattering techniques highlights their great complementarity. In particular, the large sample requirements for neutron scattering experiments prove to be an obstacle in solving the intergrowth disorder due to several growth orientations, whereas for X-ray scattering the one-dimensional nature of the intergrowth disorder renders solving this a more tractable task. On the other hand, the oxide relaxations cannot be resolved using X-rays due to the low Mn/Fe contrast. By combining the two approaches both types of disorder have been characterized.

SELECTION OF CITATIONS
SEARCH DETAIL