Inter- and Intra-physician variation in quantifying actinic keratosis skin photodamage.

We investigated the variations in physician evaluation of skin photodamage based on a published photodamage scale. Of interest is the utility of a 10-level scale ranging from none and mild photodamage to actinic keratosis (AK). The dorsal forearms of 55 adult subjects with various amounts of photodamage were considered. Each forearm was independently evaluated by 15 board-certified dermatologists according to the Global Assessment Severity Scale ranging from 0 (less severe) to 9 (the most progressed stage of skin damage). Dermatologists rated the levels of photodamage based upon the photographs in blinded fashion. Results show substantial disagreement amongst the dermatologists on the severity of photodamage. Our results indicate that ratings could be more consistent if using a scale of less levels (5-levels or 3-levels). Ultimately, clinicians can use this knowledge to provide better interpretation of inter-rater evaluations and provide more reliable assessment and frequent monitoring of high-risk populations.

Quantifying skin photodamage with spatial frequency domain imaging: statistical results.

We investigated the change in optical properties and vascular parameters to characterize skin tissue from mild photodamage to actinic keratosis (AK) with comparison to a published photodamage scale. Multi-wavelength spatial frequency domain imaging (SFDI) measurements were performed on the dorsal forearms of 55 adult subjects with various amounts of photodamage. Dermatologists rated the levels of photodamage based upon the photographs in blinded fashion to allow comparison with SFDI data. For characterization of statistical data, we used artificial neural networks. Our results indicate that optical and vascular parameters can be used to quantify photodamage and can discriminate between the stages as low, medium, and high grades, with the best performance of ∼70%, ∼76% and 80% for characterization of low- medium- and high-grade lesions, respectively. Ultimately, clinicians can use this noninvasive approach for risk assessment and frequent monitoring of high-risk populations.

Shrinkage of cutaneous specimens: formalin or other factors involved?

BACKGROUND: Shrinkage of cutaneous tissue during processing is a source of controversy. This study was designed to prospectively determine tissue shrinkage at two intervals: 1 min after excision and after 24 to 48 h of formalin fixation. Secondarily, gender, age, site, prior biopsy scar and solar elastosis were evaluated with respect to shrinkage. METHODS: Ninety-seven cutaneous specimens were measured prior to excision, 1 min after removal and after 24 to 48 h of formalin fixation. Width of prior biopsy scar, damage to elastic fibers and solar elastosis were subjectively quantified. RESULTS: Significant tissue shrinkage occurred immediately after excision, prior to formalin fixation. Mean shrinkage (95% confidence interval): length 20.66% +/- 2.15% and width 11.79% +/- 2.35%. Range of shrinkage: length 0 to 41.18% and width -18.75% (indicating expansion) to 37.50%. Patient age was significant; shrinkage decreased 0.3% per year of increasing age. Site was less significant; trunk excisions measured 5% greater shrinkage than head/neck excisions. As solar elastosis increased, shrinkage decreased. CONCLUSIONS: Cutaneous tissue shrinkage following excision is primarily because of intrinsic tissue contractility. Increasing patient age and solar elastosis correlate with less shrinkage. The clinicians and dermatopathologists must be cognizant of the expected shrinkage of submitted specimens for settling discrepancies within the medical record.

Augmentation of chemotherapy-induced cytokine production by expression of the platelet-activating factor receptor in a human epithelial carcinoma cell line.

In addition to their known cytotoxic effects, chemotherapeutic agents can trigger cytokine production in tumor cells. Moreover, many chemotherapeutic agents are potent pro-oxidative stressors. Although the lipid mediator platelet-activating factor (PAF) is synthesized in response to oxidative stress, and many epidermal carcinomas express PAF receptors (PAF-R) linked to cytokine production, it is not known whether PAF is involved in chemotherapeutic agent-induced cytokine production. These studies examined the role of the PAF system in chemotherapy-mediated cytokine production using a model system created by retroviral-mediated transduction of the PAF-R-negative human epidermal carcinoma cell line KB with the human PAF-R. The presence of the PAF-R in KB cells resulted in augmentation of the production of cytokines IL-8 and TNF-alpha induced by the chemotherapeutic agents etoposide and mitomycin C. These effects were specific for the PAF-R, as expression of the G protein-coupled receptor for fMLP did not affect chemotherapeutic agent-induced cytokine production. Moreover, ablation of the native PAF-R in the epithelial cell line HaCaT using an inducible antisense PAF-R strategy inhibited etoposide-induced cytokine production. Oxidative stress and the transcription factor NF-kappaB were found to be involved in this augmentative effect, because it was mimicked by the oxidant tert-butyl-hydroperoxide, which was blocked both by antioxidants and by inhibition of the NFkappaB pathway using a super-repressor IkappaBM mutant. These studies provide evidence for a novel pathway by which the epidermal PAF-R can augment chemotherapy-induced cytokine production through an NF-kappaB-dependent process.

Distinct patterns of gene expression in the skin lesions of atopic dermatitis and psoriasis: a gene microarray analysis.

BACKGROUND: Atopic dermatitis (AD) and psoriasis are the two most common chronic inflammatory skin diseases. Both of these diseases have distinct clinical findings and specific inflammatory cell infiltrates. Previous reports have focused individually on one or two genes or gene products in the lesions of both skin diseases. However, they have not captured the complex gene expression that must occur to induce specific cellular infiltrates in the skin lesions of these two diseases. DNA microarray studies allow the simultaneous comparison of thousands of messenger RNAs that may identify the disease-specific pattern of tissue inflammatory responses. OBJECTIVE: To compare the complex gene expression pattern of AD versus psoriasis skin lesions. METHODS: RNA was extracted from skin biopsy specimens of 6 patients with AD and 7 patients with psoriasis and analyzed with the use of Hu-U95Av.GeneChip microarrays. To confirm GeneChip results, real-time PCR of selected genes were performed. RESULTS: In AD skin, a total of 18 genes including the CC chemokines, CCL-13/MCP-4, CCL-18/PARC, and CCL-27/CTACK showed a statistically significant, >2-fold increase of gene expression compared with psoriasis. In psoriasis skin, a total of 62 genes including CCL-4/MIP-1beta, CCL-20/MIP-3alpha, CXCL-2/GRO-beta CXCL-8/IL-8, and CXCR2/IL-8R showed a >2-fold increase of gene expression compared with AD skin. Real-time PCR confirmed several of these GeneChip results. CONCLUSIONS: These results show a very distinctive gene expression pattern in AD as compared with psoriasis that may explain several features of AD and psoriasis including the specific inflammatory cell infiltrates observed in these disorders, that is, T(H)2 cells, eosinophils, and mast cells in AD and T(H)1 cells and neutrophils in psoriasis. Such observations may contribute to a characteristic "signature" for these two skin diseases.

Cytokine milieu of atopic dermatitis, as compared to psoriasis, skin prevents induction of innate immune response genes.

Atopic dermatitis (AD) and psoriasis are the two most common chronic skin diseases. However patients with AD, but not psoriasis, suffer from frequent skin infections. To understand the molecular basis for this phenomenon, skin biopsies from AD and psoriasis patients were analyzed using GeneChip microarrays. The expression of innate immune response genes, human beta defensin (HBD)-2, IL-8, and inducible NO synthetase (iNOS) was found to be decreased in AD, as compared with psoriasis, skin (HBD-2, p = 0.00021; IL-8, p = 0.044; iNOS, p = 0.016). Decreased expression of the novel antimicrobial peptide, HBD-3, was demonstrated at the mRNA level by real-time PCR (p = 0.0002) and at the protein level by immunohistochemistry (p = 0.0005). By real-time PCR, our data confirmed that AD, as compared with psoriasis, is associated with elevated skin production of Th2 cytokines and low levels of proinflammatory cytokines such as TNF-alpha, IFN-gamma, and IL-1beta. Because HBD-2, IL-8, and iNOS are known to be inhibited by Th2 cytokines, we examined the effects of IL-4 and IL-13 on HBD-3 expression in keratinocyte culture in vitro. We found that IL-13 and IL-4 inhibited TNF-alpha- and IFN-gamma-induced HBD-3 production. These studies indicate that decreased expression of a constellation of antimicrobial genes occurs as the result of local up-regulation of Th2 cytokines and the lack of elevated amounts of TNF-alpha and IFN-gamma under inflammatory conditions in AD skin. These observations could explain the increased susceptibility of AD skin to microorganisms, and suggest a new fundamental rule that may explain the mechanism for frequent infection in other Th2 cytokine-mediated diseases.