Psychiatric tests in seborrhoeic dermatitis.
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Biomedical subjects
Publications and source records attributed to Emel Calikoglu.
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We studied the reliability of teledermatology diagnoses made using a Web-based system. Clinical photographs and information relating to 125 patients were placed on a Web server. Three dermatologists made the most likely diagnosis via a Web interface. The reference diagnosis was made in a face-to-face consultation with a fourth dermatologist; where appropriate it was confirmed histologically. The teledermatologists were correct in 57% of cases when viewing the images alone. Their diagnostic accuracy improved to 70% when additional clinical information was available. The rate of agreement between the teledermatologists ranged from 44% to 70% (kappa= 0.22-0.32). Seventy-seven per cent of the patients were correctly diagnosed by at least two dermatologists when clinical information was provided. A Web-based system appears to be reliable for teledermatology. A single well trained teledermatologist may give better results than a group of less well trained clinicians.
The histological distinction between dermatofibroma (DF) and dermatofibrosarcoma protuberans (DFSP) may be extremely difficult. CD34 and Factor XIIIa have been used to differentiate DF from DFSP. However, there is an overlap and relative lack of specificity of their expressions. CD44 is a widely distributed integral membrane glycoprotein, which is expressed as a multitude of isoforms generated by alternative splicing of at least 10 different variant exons and post-translational modifications. CD44 is currently thought to be the principal cell surface receptor for hyaluronate (HA), the major component of the extracellular matrix. In this study we aimed to assess the expression of standard CD44 (CD44s) and its isoforms (CD44v3, CD44v4, CD44v5, CD44v6, CD44v7, CD44v7v8, and CD44v10), and HA in DF and DFSP. Immunohistochemical staining was performed on the biopsy specimens of 15 cases of DF and four cases of DFSP, using antibodies that recognize the CD44s, different CD44 isoforms and the hyaluronate binding protein (HABP). Tumor cells displayed a strong CD44s immunoreactivity in all cases of DF whereas a faint HA positivity was observed in the tumor stroma. The DF cells were negative for CD44v3, CD44v4, CD44v6, CD44v7 and CD44v7v8 but showed a strong reactivity for CD44v5 and CD44v10. In contrast, CD44s' expression was significantly reduced or absent in all DFSP lesions and the tumor stroma displayed strong staining for HA. Our results indicate that CD44 and HA can be used as additional diagnostic markers to distinguish DF from DFSP.
BACKGROUND: Dermatofibroma (DF) is a common benign histiocytic tumor, which has several clinicopathological variants. Myxoid DF is one of these variants, which is characterized by a stromal mucin deposition. CD44 is a polymorphic transmembrane glycoprotein and the principal cell surface receptor of hyaluronate (HA), the major component of the extracellular matrix. In a recent study, we have observed an abnormal accumulation of HA in the superficial dermis of transgenic mice with a keratinocyte-specific CD44 expression defect. We have also shown that HA was accumulated in large amounts in the superficial dermis of lichen sclerosus et atrophicus (LSA) lesions and that the epidermal CD44 expression of LSA skin was significantly decreased or lost. In an another study, we have suggested that a decrease in CD44 expression in follicular epithelial proliferations might be correlated with an abnormal HA accumulation in perifollicular solitary cutaneous myxoma. Recently we have also demonstrated that classical DF lesions displayed a strong CD44 expression in tumor cells and a weak HA positivity in tumor stroma whereas CD44 expression was significantly reduced or absent in dermatofibrosarcoma lesions and the tumor stroma showed strong HA staining. OBJECTIVE AND METHODS: Here we present 3 cases of myxoid DF, in which we explored the nature of the mucinous material in myxoid stroma by colloidal iron and hyaluronic acid binding protein stainings, as well as the expression of CD44 in the tumor cells by immunohistochemistry. RESULTS: We show that HA is accumulated in the stroma of all myxoid DF lesions with a significant decrease in CD44 expression in the tumor cells. CONCLUSION: Our results suggest that a decrease in CD44 expression in the tumor cells may result in stromal myxoid changes characterized by an abnormal HA accumulation in myxoid DF.
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BACKGROUND: Myxomas are rare cutaneous tumors which may be solitary or associated with Carney's complex, NAME or LAMB syndromes. The mucinous material which constitutes the stroma of cutaneous myxomas is predominantly composed of hyaluronate (HA), the major component of the extracellular matrix. CD44 is a polymorphic integral membrane glycoprotein which serves as the principal cell surface receptor for HA. OBJECTIVE AND METHODS: Here we present 2 cases of solitary cutaneous myxomas displaying microscopically a perifollicular localization, in which we explored the nature of the accumulated mucinous material by colloidal iron and HA-binding protein stainings, as well as the epidermal expression of CD44 protein by immunohistochemistry. RESULTS: We show that HA is accumulated in the stroma of the cutaneous myxoma lesions and that the protein expression of CD44 in the keratinocytes of the trichofolliculoma-like epithelial buds projecting from the hair follicle centering these lesions is significantly decreased. CONCLUSIONS: Our results suggest that a decrease in CD44 expression in follicular epithelial proliferations may be correlated with an abnormal HA accumulation in cutaneous myxoma.
The transmembrane glycoprotein CD44 is currently thought to be the main cell surface receptor for the glycosaminoglycan hyaluronate. We previously showed that (1) CD44 regulate keratinocyte proliferation; (2) topical retinoids dramatically increase the expression of CD44, hyaluronate and hyaluronate synthase (HAS)s in mouse epidermis; (3) topical retinaldehyde restores the epidermal thickness and CD44 expression which are correlated with clinical improvement in lichen sclerosus et atrophicus lesions; and (4) retinaldehyde-induced proliferative response of keratinocytes is a CD44-dependent phenomenon and requires the presence of HB-EGF, erbB1 and matrix metalloproteinases. In this study, we analyzed the effect of UV irradiation on the levels of epidermal hyaluronate and CD44 in mice, as well as its potential prevention by topical retinoids. UVA (10 J/cm(2)) or UVB (1 J/cm(2)) irradiation significantly decreased the expression of CD44 and hyaluronate in the epidermis of hairless mice after 2 h. Expression of both epidermal CD44 and hyaluronate was reconstituted within 24 h. Topical application of retinaldehyde for 3 days prior to UVA or UVB irradiation prevented the decrease of CD44 and hyaluronate expression. Topical retinol and retinoic acid also increased the basal levels of epidermal CD44 and hyaluronate, although their preventive effect on UV-induced decrease of these molecules was less pronounced as compared to topical retinaldehyde. These data confirm the relationships between retinoid and CD44 pathways, although the primary target(s) of UV leading to CD44 and hyaluronate degradation remain to be elucidated.