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Changes in skin protection behaviors, attitudes, and sunburn: in a population with the highest incidence of skin cancer in the world.

This study describes changes in skin protection attitudes and outdoor behaviors of adults in Queensland, Australia, using two cross-sectional telephone surveys conducted in 1988/89 (N = 1699) and 1991/92 (N = 2317). After adjustment for potential confounders, there were significant improvements in some skin protection attitudes, time spent outside, hat wearing, sunscreen use, overall skin protection (p < 0.01) and shade use (p < 0.05) between 11:00 AM and 3:00 PM on the previous Sunday. The degree of attitudinal and behavioral change varied with age, gender, region, and reported skin type. However, recent sunburn experience remained unchanged. A similar study in Victoria, Australia, observed changes in skin protection attitudes, behaviors, and recent sunburn. We speculate on possible explanations for the lack of improvement in recent sunburn experience despite the improvement in skin protection attitudes, and behaviors, and suggest that part of the explanation may be environmental differences. This has implications for generalizability of such studies outside the geographical region in which they were conducted.

Adolescent↗

Radionuclide therapy of skin cancers and Bowen's disease using a specially designed skin patch.

UNLABELLED: Skin cancer is the most common malignancy in humans. Therapeutic modalities for skin cancer are local destruction, radiotherapy and surgery. External radiation therapy leads to good results, however, generally 5-6 wk of treatment is needed to deliver optimal radiation dose to tumors. In this study, a beta-emitting radionuclide, 166Ho, impregnated in a specially designed patch, was used on superficial skin cancers and Bowen's disease for local irradiation. METHODS: Ten mice with chemically induced skin tumors were studied. Five-millimeter size patches containing 22.2-72.15 MBq (0.6-1.95 mCi) 166Ho were applied to the tumor surface for 1-2 hr. In a human trial, patients with squamous-cell carcinoma (n = 3), basal cell carcinoma (n = 1) and Bowen's disease (n = 1) were treated with patches containing 273.8-999 MBq (7.4-27 mCi) of 166Ho for 30 min to 1 hr. Pathologic examination was performed 4-7 wk after treatment in an animal model. Skin biopsy was performed 8 wk post-treatment in four patients. RESULTS: Tumor destruction was seen 1 wk post-treatment, however, radiation dermatitis or ulceration developed at the site of radionuclide application. Those reactions healed gradually with fibrosis or epithelialization, which was confirmed pathologically. No significant adverse reaction to radiation except subcutaneous fibrosis was found. CONCLUSION: Superficial skin tumors could be successfully treated by topical application of beta-emitting radionuclides.

Adult↗

Do public media campaigns designed to increase skin cancer awareness result in increased skin excision rates?

We report on an observational study of one city in Queensland over a 30-month period to evaluate the effects of two public skin cancer campaigns on the excision rates of melanocytic skin lesions. The numbers of melanomas, the numbers of potentially malignant melanocytic lesions (Hutchinson's melanotic freckles and dysplastic naevi) whose excision might have benefited the patient, and the total number of melanocytic skin lesions submitted to pathology services were recorded. A total of 3221 melanocytic skin lesions were excised. More lesions were excised during summer than non-summer periods (rate ratio 1.22, 95% CI 1.06, 1.40) and, independently, during campaign periods than non-campaign periods (rate ratio 1.24, 95% CI 1.11, 1.37). There were 145 melanomas (4%), of which 116 were < 0.76 mm thick, and an additional 53 (2%) other potentially malignant lesions. During campaigns, proportions of neither type increased significantly, nor was there a significant reduction in excised melanoma thickness. Doctors reported more often that the reason for excision was to exclude malignancy during the campaigns, although they felt themselves to be under less pressure from patients to excise lesions. There may be considerable cost associated with primary prevention campaigns in the form of increased excision of benign skin lesions, which should be addressed in future skin cancer public awareness campaigns.

Australia↗

Mechanisms of photodamage of the skin and its functional consequences for skin ageing.

Chronic photodamage of the skin manifests itself as extrinsic skin ageing (photoageing) and photocarcinogenesis. DNA photodamage and UV-generated reactive oxygen species are the initial molecular events that lead to most of the typical histological and clinical manifestations of chronic photodamage of the skin. Knowledge of the UV-absorbing chromophores in the skin and of the molecular mechanisms leading to the unwanted effects of sun exposure provide a basis for the development of novel strategies for the prevention and repair of photoageing. This review provides an overview of the photochemistry of the major skin chromophores and their relationship to chronic photodamage.

Amino Acids↗

Protective immunity to UV radiation-induced skin tumours induced by skin grafts and epidermal cells.

There is little evidence that cutaneous dendritic cells (DC), including epidermal Langerhans cells (LC), can induce immunity to UV radiation (UVR)-induced skin tumours. Here, it is shown that cells within skin can induce protective antitumour immunity against a UVR-induced fibrosarcoma. Transplantation of the skin overlying subcutaneous tumours onto naïve recipients could induce protective antitumour immunity, probably because the grafting stimulated the tumour Ag-loaded DC to migrate to local lymph nodes. This suggests that cutaneous APC can present tumour Ag to induce protective antitumour immunity. Previously, it has been shown that immunization of mice with MHC class II+ epidermal cells (EC) pulsed with tumour extracts could induce delayed-type hypersensitivity against tumour cells. Here, this same immunization protocol could induce protective immunity against a minimum tumorigenic dose of UVR-induced fibrosarcoma cells, but not higher doses. Epidermal cells obtained from semiallogeneic donors and pulsed with tumour extract could also induce protective immunity. However, presentation of BSA Ag from the culture medium was found to contribute to this result using semiallogeneic EC. The results suggest that LC overlying skin tumours may be able to induce protective immunity to UVR-induced tumours if stimulated to migrate from the skin.

Animals↗

Combination of a new composite biocampatible skin graft on the neodermis of artificial skin in an animal model.

INTRODUCTION: There have been very limited and inconsistent attempts at combining the cultured epidermal autograft (CEA) with the neodermis of artificial skin (Integra). The reasons for this remain unknown. The basement membrane proteins of conventional CEA sheets are easily damaged by the dispase treatment during the harvesting of the CEA from the culture flask. The damage of the basement membrane proteins may affect the anchorage of CEA onto the neodermis of Integra. A new Composite Biocompatible Skin Graft (CBSG) was recently developed. METHODS: Composite biocompatible skin graft consists of autologous keratinocytes cultivated on a pliable hyaluronate-derived membrane (Laserskin)which has been pre-seeded with allogenic dermal fibroblasts. Basement membrane proteins of CBSG are protected from the dispase treatment because the keratinocytes are directly seeded onto Laserskin. The engraftment of CBSG was evaluated on 20 wounds of 10 rats. Integrawas grafted on two freshly excised full-thickness wounds (3cm in diameter) in the dorsum of each animal. A polypropylene ring was applied to each wound to prevent the migration of epithelium from the edges. Composite Biocompatible Skin Graft was used to cover the neodermis of Integra after the silicone membrane was removed 14-21 days postgrafting. RESULTS: Fourteen (70%) of 20 skin biopsies taken at day 21 from the centre of the grafted wounds revealed regenerated epithelium. CONCLUSION: A feasible delivery system of cultured keratinocytes onto theneodermis of Integra is demonstrated in this animal -experiment.

Animals↗

Differentiation-associated localization of nPKC eta, a Ca(++)-independent protein kinase C, in normal human skin and skin diseases.

The expression of nPKC eta, a Ca(++)-independent isoform of protein kinase C in normal human skin, and skin from patients with psoriasis, squamous cell carcinoma, basal cell epithelioma, nevus pigmentosus, and seborrheic keratosis, were examined by immunohistochemical staining using a polyclonal antibody raised against a synthetic peptide at a diverse region of the nPKC eta molecule. In normal epidermis, the strongest staining was observed in the uppermost granular layer with no staining of the spinous or basal layers. The inner layer of the intra-epidermal eccrine duct was also strongly stained. Weak staining was observed in several layers of the outer root sheath of the follicular infundibulum. No staining was detected in the inner root sheath of the hair follicles, hair matrix, sebaceous gland, eccrine gland, intradermal eccrine duct, arrectores pilorum, melanocytes, Langerhans cells, fibroblasts, or blood vessels. In psoriatic skin, stained keratinocytes were distributed in the suprabasal layers with the most being observed in the uppermost layer and the least in layers closed to the basal layer. In squamous cell carcinoma, weak staining was observed in the keratotic cells around horny pearls. In the basal cell epithelioma and nevus pigmentosus, the cells were not stained, whereas in seborrheic keratosis, cells that stained were located in the granular layer. We conclude from the evidence presented above that nPKC eta is expressed in close association with epidermal differentiation in normal skin and skin diseases.

Adult↗

Permeation and skin absorption: reproducibility of various industrial reconstructed human skin models.

Human reconstructed skin models could be very useful tools to quantify percutaneous permeation and absorption. Before using such models, the reproducibility in the same batch and/or various batches, i.e. the relevance of the results obtained, must be verified. The reproducibility of 3 industrial models--EpiDerm, Episkin and SkinEthic--was tested regarding the permeation and skin absorption of 3 topically applied compounds (with a large range of physicochemical properties): lauric acid, caffeine and mannitol. For all the models, the intrabatch reproducibility was greater than the interbatch reproducibility. According to the batches tested, the larger difference in terms of reproducibility between the 3 models was observed in the case of mannitol, a very poor permeant. In this case, the best reproducibility was observed with EpiDerm and Episkin. Moreover, the rank order of the 3 compounds applied, in terms of permeation and skin absorption, was the same as that expected from ex vivo human skin. Such results revealed human skin models as a promising means to test in vitro permeation and percutaneous absorption of topical products.

Drug Evaluation, Preclinical↗

Up- and down-regulation of granulocyte/macrophage-colony stimulating factor activity in murine skin increase susceptibility to skin carcinogenesis by independent mechanisms.

The role of granulocyte-macrophage colony-stimulating factor (GM-CSF) in tumorigenesis is complex. On the one hand, GM-CSF can promote tumor cell growth, survival, and even metastasis. On the other hand, it can stimulate tumor cell rejection. In skin, it is early expressed after topic application of tumor-promoting agents and therefore may be responsible for changes that correlate with skin tumor promotion (e.g., epidermal hyperproliferation and inflammation). To analyze GM-CSF function in skin tumorigenesis, we generated transgenic mice epidermally overexpressing either GM-CSF or a GM-CSF antagonist. Both types of transgenic mice exhibited significantly increased numbers of benign tumors in a two-step skin carcinogenesis experiment using 7',12'-dimethylbenz[a]anthracene (DMBA) as initiator and 12-O-tetradecanoylphorbol-CSF displayed a significantly elevated carcinoma burden following a single-step carcinogenesis protocol consisting of tumor initiation only. Therefore, endogenous promotion is responsible for elevated tumor development in GM-CSF-overexpressing mice. In antagonist transgenic animals, an increased tumorigenicity of modified B16 tumor cells after cutaneous transplantation as compared with nontransgenic or GM-CSF transgenic mice was observed. Thus, the antitumor activity leading to the repression of tumor cell growth in control mice is GM-CSF dependent and is compromised in mice expressing the antagonist. We suggest that both, up-regulation and down-regulation of GM-CSF activity in skin, increase the incidence and growth of tumors via two independent mechanisms: endogenous tumor promotion in the case of increased GM-CSF activity and compromised tumor cell rejection in the case of decreased GM-CSF activity.

9,10-Dimethyl-1,2-benzanthracene↗

Structure and function of the skin. Are there differences between black and white skin?

In concluding my remarks on structure and function of the skin, I wish to make one additional observation. Most dermatologists have acknowledged the role of the skin and its ability to protect the human organism from invasion by pathogenic organisms. There is good scientific evidence that skin plays an important protective role. Although an intact epidermis is of utmost importance as a protective unit, the contribution of the "acid mantle" is of considerable magnitude. The acidity or alkalinity and stability of this mantle is contributed to, in large measure, by the presence of eccrine gland secretions and sebaceous gland secretions. It is then not logical to assume that if black skin contains larger numbers of large and overly active adnexal glands, it would have a most effective mechanism for control of bacterial, viral, and other infections? That this is not the situation becomes apparent in the discussions that follow on cutaneous infections in black skin.

Black People↗

Skin symptoms and work-related skin symptoms among grape farmers in Crete, Greece.

BACKGROUND: Grape farmers are exposed to a variety of agents capable of inducing occupational skin disease. We conducted a study to measure the prevalence of skin symptoms and work-related skin symptoms among grape farmers in the Malevisi region of Crete and to provide data on associated risk factors. METHODS: One hundred twenty grape farmers and 100 controls participated in the study. The protocol consisted of a questionnaire, skin prick tests for 16 common allergens, and measurement of specific IgE antibodies against 8 allergens. RESULTS: Self-reported itchy rash (OR, 2.31; 95%CI, 1.10-4.84, P<0.05) within the last 12 months, and work-related itchy rash (OR, 4.08; 95%CI, 1.01-20.33, P<0.05) were significantly higher in grape farmers than in controls, after adjusting for age and sex. Sensitization to pollens (OR, 4.20; 95% CI, 1.41-12.82, P<0.01) and allergic rhinitis (OR, 3.06; 95% CI, 1.21-8.28, P<0.05) were found to be significantly associated with self-reported itchy rash in the grape farmers group. CONCLUSIONS: Grape farmers reported skin symptoms more frequently than non-exposed controls, and IgE-mediated sensitization to pollens was found to be significantly associated with the reported symptoms. Further studies are needed to evaluate the impact of specific occupational agents on skin diseases among grape farmers.

Adult↗

Proteomic analysis of skin irritation reveals the induction of HSP27 by sodium lauryl sulphate in human skin.

BACKGROUND: There is an increasing need for screening of mild irritants in vitro to reduce animal testing. OBJECTIVES: Proteomics were used to search for new markers of which the expression changes after mild irritation. METHODS: Sodium lauryl sulphate (SLS) was applied topically on excised human skin. Epidermal proteins were isolated from SLS-treated skin specimens that showed hardly any morphological changes. The proteins were analysed by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and proteins that significantly increased or decreased after SLS treatment in a dose-dependent way were characterized by mass spectrometry. Subsequently, immunohistochemistry was performed on skin samples treated with SLS in vivo and nonanoic acid (NAA) or benzalkonium chloride (BC) in vitro to evaluate one of the identified proteins for its predictive value. RESULTS: We identified seven proteins as potentially new epidermal markers for skin irritation. Among these seven proteins, the 27 kDa heat shock protein (HSP27) was identified as the most prominently upregulated protein. A strong nuclear HSP27 staining was seen in the SLS-treated skin, whereas in the vehicle controls only cytoplasmic staining was observed. Moreover, nuclear staining was also observed after topical application of SLS in vivo and after exposure to NAA and BC in vitro. CONCLUSIONS: Our findings suggest that HSP27 may serve as a sensitive marker of skin irritation and eventually as a novel tool in clinics for testing the sensitivity of the patient for a panel of irritants.

Animal Testing Alternatives↗

Surface electrical capacitance as an index of epidermal barrier properties of composite skin substitutes and skin autografts.

Restoration of the epidermal barrier is a requirement for burn wound closure. A rapid, reliable, and noninvasive measure of the rate of restoration of the epidermal barrier is not readily available. To monitor the reformation of the epidermal barrier, we measured surface electrical capacitance on cultured skin substitutes (human keratinocytes and fibroblasts attached to collagen-glycosaminoglycan substrates) and split-thickness skin autografts grafted to patients. Data were collected from four patients with burns and one pediatric patient with a congenital hairy nevus comprising > 60% total body surface area. Capacitance measurements were performed at days 7, 10, 12, 14, and 28 by direct contact of the capacitance probe for 10 seconds to the cultured skin substitutes or split-thickness autograft. On postoperative days 7, 10, 12, 14, 21, and 28, the surface electrical capacitance of cultured skin substitutes after 10 seconds of sampling was 2468 +/- 268, 1443 +/- 439, 129 +/- 43, 200 +/- 44, 88 +/- 20, and 74 +/- 19 picofarads (mean +/- standard error of the mean), respectively. Surface electrical capacitance for split-thickness autograft on the same days was 1699 +/- 371, 1914 +/- 433, 125 +/- 16, 175 +/- 63, 110 +/- 26, 271 +/- 77 picofarads, respectively. Surface electrical capacitance in all of the grafts decreased with time. Cultured skin substitutes had approximately the same 10-second capacitance values as split-thickness autograft during 3 weeks of healing and approached values for uninjured skin (32 +/- 5 picofarads) by 12 days. Measurement of surface electrical capacitance is a direct, inexpensive, and convenient index for noninvasive monitoring of epidermal barrier formation.

Journal Article↗

Assessment of epidermal subpopulations and proliferation in healthy skin, symptomless and lesional skin of spreading psoriasis.

BACKGROUND: The margin zone in spreading psoriatic lesions has frequently been used as a model to study the changes in epidermal proliferation, keratinization and inflammation during the transition from symptomless to lesional skin. However, the dynamics of the changes in the epidermal subpopulations-basal cells, transit amplifying cells and differentiated cells-have not been studied in the transition between symptomless and lesional skin. OBJECTIVES: To quantify in a dynamic model of the margin zone in psoriasis the characteristics of these subpopulations with respect to epidermal proliferation and differentiation. METHODS: From seven patients with active psoriasis, biopsies were taken from the distant uninvolved skin, outer margin, inner margin and centre of a spreading psoriatic plaque. Frozen sections were labelled immunofluorescently using direct immunofluorescence for Ki-67 and beta1 integrin and the Zenon labelling technique for keratin 6, 10 and 15. Digital photographs of the stained sections were quantitatively analysed. RESULTS: In the distant uninvolved skin the expression of beta1 integrin was decreased and keratin 15 expression was lost. In this area suprabasal cells expressed beta1 integrin and in the outer margin suprabasal cells expressed Ki-67. From the outer to the inner margin of the psoriasis plaque, which coincided with the appearance of the clinical lesion, there was a significant change in the various markers. The patchy expression of keratin 6 in the inner margin became homogeneous in the centre of the psoriasis plaque and here was also coexpression of keratin 6 and keratin 10 in a single cell. CONCLUSIONS: The present study provides additional evidence that the distant uninvolved skin has a prepsoriatic phenotype, which is the first step in a psoriatic cascade. The cascade between symptomless and lesional skin comprises first an abnormality in inflammation with involvement of beta1 integrin-dim cells (transit amplifying cells) subsequently eliciting an enlarged germinative compartment with increased recruitment of cycling epidermal cells and focal expression of proliferation-associated keratins, ultimately culminating in a more-or-less homogeneous epidermis with massive recruitment of cycling epidermal cells and proliferation-associated keratinization.

Cell Differentiation↗