In order to obtain a comprehensive picture of the molecular events regulating cutaneous photodamage of intact human epidermis, suction blister roofs obtained after a single dose of in vivo ultraviolet (UV)B exposure were used for microarray profiling. We found a changed expression of 619 genes. Half of the UVB-regulated genes had returned to pre-exposure baseline levels at 72 h, underscoring the transient character of the molecular cutaneous UVB response. Of special interest was our finding that several of the central p53 target genes remained unaffected following UVB exposure in spite of p53 protein accumulation. We next compared the in vivo expression profiles of epidermal sheets to that of cultured human epidermal keratinocytes exposed to UVB in vitro. We found 1931 genes that differed in their expression profiles between the two groups. The expression profile in intact epidemis was geared mainly towards DNA repair, whereas cultured keratinocytes responded predominantly by activating genes associated with cell-cycle arrest and apoptosis. These differences in expression profiles might reflect differences between mature differentiating keratinocytes in the suprabasal epidermal layers versus exponentially proliferating keratinocytes in cell culture. Our findings show that extreme care should be taken when extrapolating from findings based on keratinocyte cultures to changes in intact epidermis.

The mycosporine-like amino acid (MAA), porphyra-334 (lambda(max) = 334 nm; epsilon = 42,300 M(-1) cm(-1)), was isolated from the aquatic cyanobacterium Aphanizomenon flos-aquae (AFA) and its structure was verified by spectroscopic methods. The UVA absorption properties of the crude methanolic extract were determined against two commercial sun care products in terms of mean critical wavelength, mean UVA/UVB ratios and UVA protection category (Boots the Chemists, Ltd.). The crude methanolic extract from AFA exhibited maximum UVA protection comparable to that determined for Boots SPF 4.

A novel photo protective mycosporine was isolated from the lichenized ascomycete Collema cristatum. Biological activity was measured in terms of protection against UV‐B induced membrane destruction and pyrimidine dimer formation in cultured human keratinocytes, and prevention of UV‐B induced erythema. It was found that the pure isolated compound prevented UV‐B induced cell destruction in a dose‐dependent manner, that the compound partially prevented pyrimidine dimer formation and completely prevented UV‐B induced erythema when applied to the skin prior to irradiation.

Published data on the prevalence of onychomycosis in psoriasis patients compared with healthy controls are controversial, We therefore conducted a prospective study of toenail onychomycosis, among 113 psoriatic and 106 healthy non-psoriatic subjects, selected from the normal population in the Jerusalem area in the period 2003-05. The results revealed a prevalence of 47.6% toenail onychomycosis among psoriatic patients, compared with 28.4% in normal controls (p=0.0054). Both gender and age affected the prevalence of onychomycosis in both psoriatic and healthy controls, with a higher prevalence in male and elderly subjects. The type and duration of psoriasis were also found to have an impact on the prevalence of onychomycosis. However, the body area involved did not affect the prevalence of onychomycosis in psoriatic patients. Approximately the same percentages of dermatophytes and yeasts were found in psoriatic patients as in healthy controls. However, a higher percentage of moulds was found in psoriatic patients.

Onychomycosis is caused by dermatophyte infection of the nail. Though laser energy has been shown to eliminate dermatophytes in vitro, direct laser elimination of onychomycosis is not successful due to difficulties in selectively delivering laser energy to the deeper levels of the nail plate without collateral damage. Femtosecond (fsec) infrared titanium sapphire lasers circumvent this problem by the nonlinear interactions of these lasers with biological media. This quality, combined with the deeply penetrating nature of the near-infrared radiation, allows elimination of deeply seeded nail dermatopytes without associated collateral damage. Nail cuttings obtained from patients with onychomycosis caused by Trichophyton rubrum underwent fsec laser irradiation using increasing laser intensities with the focus scanned throughout the whole thickness of the nail specimen. The efficacy of the laser treatment was evaluated by subculture. Scanning electron microscopy was used to determine fsec laser-induced collateral damage. We found that a fsec laser fluence of 7 x 10(31) photons m(-2) s(-1) or above successfully inhibited the growth of the fungus in all samples examined, whereas laser intensities above 1.7 x 10(32) photons m(-2) s(-1) affected the structure of the nail plate. Our findings suggest that T. rubrum-mediated onychomycosis may be treated by fsec laser technology.

Exposing skin to ultraviolet (UV) radiation contributes to photoaging and to the development of skin cancer by DNA lesions and triggering inflammatory and other harmful cellular cascades. The present study tested the ability of unique lipid molecules, polyhydroxylated fatty alcohols (PFA), extracted from avocado, to reduce UVB-induced damage and inflammation in skin. Introducing PFA to keratinocytes prior to their exposure to UVB exerted a protective effect, increasing cell viability, decreasing the secretion of IL-6 and PGE(2), and enhancing DNA repair. In human skin explants, treating with PFA reduced significantly UV-induced cellular damage. These results support the idea that PFA can play an important role as a photo-protective agent in UV-induced skin damage.

IGFBP7 is underexpressed in psoriatic epidermis but is inducible by UVB.

SummaryData in the literature regarding the prevalence of Candida in psoriatic and atopic dermatitis patients are controversial. We conducted a prospective study to determine the prevalence of Candida on the tongue, axillae and groin of psoriatic patients when compared with atopic dermatitis patients and normal controls. During the period 2003-2005, data were collected from 100 psoriatic patients, 100 patients with atopic dermatitis and 100 normal controls. Fungal test specimens for Candida were collected from the axillae, groin and tongue of each patient. There was no increase in the prevalence of Candida in intertriginous area of either psoriatic or atopic dermatitis patients. However, the prevalence of Candida on the tongue was significantly higher in psoriatic patients (32%) compared with atopic dermatitis (18%) (P = 0.024) and higher, although not significantly, than in normal controls (21%) (P = 0.08). Our study did not reveal higher prevalence of Candida in the axillae and groin of either psoriatic or atopic dermatitis patients. There was a higher prevalence of Candida on the tongue of psoriatic patients. The Candida of the tongue was asymptomatic and did not correlate with age, gender, type of psoriasis or severity of the disease, therefore we conclude that this is clinically irrelevant.