The Experts below are selected from a list of 987 Experts worldwide ranked by ideXlab platform

Alexander Vincent Anstey - One of the best experts on this subject based on the ideXlab platform.

Charles R. Taylor - One of the best experts on this subject based on the ideXlab platform.

L E Rhodes - One of the best experts on this subject based on the ideXlab platform.

  • ultraviolet radiation induced upregulation of antimicrobial proteins in health and disease
    Photochemical and Photobiological Sciences, 2013
    Co-Authors: Sarah Felton, Fatemeh Navid, Agatha Schwarz, Regine Glaser, T. Schwarz, L E Rhodes
    Abstract:

    This article reviews recent data on the expression, regulation and activation of antimicrobial peptides (AMP) in human skin, and considers their potential protective and pro-inflammatory roles following upregulation by ultraviolet radiation (UVR). Antimicrobial peptides are small peptides that are key components of the innate immune system, originally identified by their vital role in protecting the body-environment interface from infection. However, it has now become clear that AMP have more extensive actions, including the provision of pivotal links with the adaptive immune system. Moreover, aberrant AMP expression may contribute to immuno-modulated inflammatory dermatoses including psoriasis, eczema and the photoaggravated condition lupus erythematosus. Recent work has demonstrated the direct upregulation of AMP in healthy skin by cutaneous UVR exposure. This may serve to protect the skin from risks imposed by both the biophysical barrier-compromise and the immunosuppression that are attributable to UVR exposure. Furthermore, it is observed that UVR provokes upregulation of AMP in an atypical manner in the Photosensitivity Disorder polymorphic light eruption. Dysregulated UVR responses of these pro-inflammatory proteins may play a role in the pathogenesis of certain immune-mediated diseases caused or aggravated by sunlight.

  • systemic photoprotection in solar urticaria with α melanocyte stimulating hormone analogue nle4 d phe7 α msh
    British Journal of Dermatology, 2011
    Co-Authors: Ann K Haylett, Mark Brownrigg, R Taylor, L E Rhodes
    Abstract:

    Summary Background  Solar urticaria is a rare Photosensitivity Disorder demonstrating a range of action spectra, which can inflict a very large impact on life quality despite available treatments. Melanin broadly reduces skin penetration by ultraviolet–visible wavelengths, thus increased melanization may protect in solar urticaria. Objectives  To examine quantitatively for impact of the potent α-melanocyte stimulating hormone analogue afamelanotide ([Nle4-d-Phe7]-α-MSH, Scenesse®; Clinuvel Pharmaceuticals Ltd, Melbourne, Vic., Australia) on the solar urticaria response and skin melanization. Methods  Five patients with solar urticaria received a single dose of 16 mg subcutaneous afamelanotide implant in winter time. Melanin density was assessed spectrophotometrically from day 0 to day 60. Detailed monochromated light testing to geometric dose series (increment ) of wavelengths 300–600 nm was performed at 0, 30 and 60 days, with assessment of weal and flare area and minimum urticarial dose (MUD). Data were analysed by repeated-measures anova. Results  Mean melanin density increased by day 7, peaked at day 15 and remained elevated at day 60 (P = 0·03, 0·01, 0·02 vs. baseline, respectively). Baseline phototesting revealed action spectra of 320–400 (n = 1), 320–500 (n = 2), 300–600 (n = 1) and 370–500 nm (n = 1), and on afamelanotide mean rises in MUD of 1–12 and 1–3 dose increments were seen at the individual wavelengths tested, at 30 and 60 days, respectively. A significant fall in weal area occurred across responding wavelengths from 300 to 600 nm at 60 days postimplant (P = 0·049 vs. baseline), accompanied by greater than twofold overall increase in MUD (P = 0·058 vs. baseline). Conclusions  Melanization following afamelanotide is accompanied by reduction in solar urticaria response across a broad spectrum of wavelengths. Further study is warranted to assess clinical benefit under ambient conditions in summer.

I M Leigh - One of the best experts on this subject based on the ideXlab platform.

  • recurrent mutations in kindlin 1 a novel keratinocyte focal contact protein in the autosomal recessive skin fragility and Photosensitivity Disorder kindler syndrome
    Journal of Investigative Dermatology, 2004
    Co-Authors: Gabrielle H S Ashton, W Irwin H Mclean, Andrew P South, Noritaka Oyama, Frances J D Smith, Raouf Alsuwaid, Abla Al Ismaily, David J Atherton, C A Harwood, I M Leigh
    Abstract:

    Kindler syndrome (OMIM 173650) is a rare autosomal recessive Disorder characterized by trauma-induced blister formation (especially in childhood) and Photosensitivity. Other features include mucocutaneous scarring and progressive poikiloderma. There is also an increased risk of skin and mucous membrane malignancy. The Disorder was recently mapped to 20p12.3 and pathogenic mutations were identified in a new gene, KIND1. This gene encodes a 677 amino acid protein, kindlin-1, a component of focal contacts in keratinocytes. In this study, we identified four new recurrent mutations in KIND1 in 16 individuals with Kindler syndrome from 13 families of Pakistani (676insC), UK Caucasian (E304X), Omani (W616X), or Italian (958–1G > A) origins. Haplotype analysis demonstrated common ancestral mutant alleles for each mutation, apart from one of the six Pakistani families in which the mutation 676insC (which occurs in a repeat of seven cytosines) was present on a different genetic background. All mutations were homozygous, apart from the three UK Caucasian cases that were all compound heterozygotes (second allele mutations: L302X, 1161delA, 1909delA). All mutations were associated with markedly reduced or absent skin immunostaining with an antikindlin-1 antibody. These loss-of-function KIND1 mutations demonstrate the importance of kindlin-1 in maintaining epithelial integrity, although the mechanism linking this mutant protein to Photosensitivity and poikiloderma remains to be determined. Delineation of these recurrent mutations is also relevant to optimizing mutation detection strategies in Kindler syndrome patients from particular ethnic backgrounds.

Andreas Katsambas - One of the best experts on this subject based on the ideXlab platform.

  • Spectrum of idiopathic photodermatoses in a Mediterranean country.
    International journal of dermatology, 2003
    Co-Authors: Alexander J. Stratigos, Christina Antoniou, Evangelia Papathanakou, Maria Daboudi, Konstantina Tranaka, Konstantina Tsara, Andreas Katsambas
    Abstract:

    Background  Idiopathic photodermatoses are considered to be common Disorders in the population of northern latitude countries, presumably because of the dominance of more “sun-sensitive” individuals with a light-skinned complexion. The incidence of these Disorders in the Mediterranean or tropical countries is often under-appreciated because of the higher degree of perennial presence of sunlight and the prevalence of darker skin-type individuals who are seemingly more resistant to the development of sun sensitivity. Methods  We performed a retrospective, chart-based review of all patients who were diagnosed with idiopathic photodermatoses at a photodermatology referral center in Athens, Greece, during a period of 10 years. Our aim was to assess the pattern of idiopathic Photosensitivity Disorders in a Mediterranean country and to determine their epidemiological, clinical, and photobiological profile. Results  A total of 310 patients were referred to our center with symptoms of Photosensitivity. One hundred and forty-six patients (47.0%) were diagnosed with an idiopathic Photosensitivity Disorder by means of history, clinical examination, biochemical screening, histology, and phototesting. The most prevalent Disorder was polymorphous light eruption, which was diagnosed in 95 patients (65.0%) of our cohort. Chronic actinic dermatitis occurred in 15 patients (10.2%), solar urticaria in 26 patients (17.8%), actinic prurigo in three patients (2.0%), hydroa vacciniforme in one patient (0.6%) and juvenile spring eruption in six patients (4.1%). Conclusions  Compared with the results of other studies, the prevalence of idiopathic photodermatoses appears to have a similar trend to that of higher latitude countries. Distinct features in our series include the higher incidence of idiopathic Photosensitivity in patients with a fair-skinned complexion (skin types II–III) and the frequent appearance of photo-induced eruptions during sunny weather breaks in the winter period.

  • evaluation of the role of contact sensitization and Photosensitivity in the pathogenesis of poikiloderma of civatte
    British Journal of Dermatology, 2002
    Co-Authors: A C Katoulis, N G Stavrianeas, Alexandra Katsarou, C Antoniou, S Georgala, Dimitris Rigopoulos, E Koumantaki, G Avgerinou, Andreas Katsambas
    Abstract:

    Summary Background Poikiloderma of the face and neck (Civatte) is a rather common, indolent, chronic dermatosis, most often affecting menopausal females. Cumulative excessive sun exposure, a phototoxic or a photoallergic reaction, hormonal changes of menopause and genetic factors have all been incriminated in its obscure aetiopathogenesis. Objectives To evaluate the role of contact sensitization and Photosensitivity in the pathogenesis of poikiloderma of Civatte (PC). Methods Thirty-two patients (24 females and eight males, age range 38–74 years) with PC were patch tested with the European standard series and the fragrance series, and were photopatch tested with the photoallergens series. Additionally, photo-testing with a monochromator was performed. Results Thirteen of 32 patients (40·62%) had one or more positive reactions to allergens of the standard series. Eight patients (25%) had positive reactions to fragrance mix and/or Balsam of Peru, which are included in the standard series, or to allergens of the fragrance series. Nickel sulphate was the single most common cause of contact sensitization (18·75%) among our patients. Ninety-seven subjects, who were patch tested with the standard series for suspected allergic contact dermatitis of the face and/or neck, served as age, sex and site controls. Of these, nine (9·27%) had one or more positive reactions to fragrance compounds. Statistical analysis showed a statistically significant difference in the frequency of positive reactions to fragrances between the PC group and the control group (χ2 value = 3·91, P < 0·05). In contrast, none of the PC patients had a positive photopatch test for the allergens included in the photoallergens series. The estimated minimal erythemal dose for the PC group was in all cases within normal limits for all wavelengths of ultraviolet (UV) radiation examined. Conclusions Contact sensitization, mostly to perfume ingredients, may develop in PC, possibly playing a pathogenetic part, at least in a subset of patients. Despite negative results of photopatch testing, an allergic photo-contact reaction cannot be definitely excluded. PC seems not to be a Photosensitivity Disorder of the type of chronic actinic dermatitis. UV radiation-induced dermal connective tissue changes are the predominant histological feature of PC, leading to telangiectasia due to loss of vascular support. Reticular pigmentation may result from a delayed hypersensitivity reaction to perfume and/or cosmetic ingredients. Patch testing with the standard series and avoidance of documented allergens may be of value in patients with PC.