摘要:

SUMMARYIntrinsic (chronological) skin ageing is characterized hy atrophy of the skin with loss of elasticity and slowed metabolic activity. The superposition of environmental damage, particularly exposure to ultraviolet radiation (photodamage). on the intrinsic ageinj; process results, at least initially, in a hypcrtrophic repair response, with a thickened epidermis and increased melanogenesis. Even more striking changes occur in the dcrmis: massive elastosis (deposition of abnormal elastic libres). collagen degenerafion. and twisted, dilated microvasculature. ReguUir use of a sunscreen alone appears to allow some repair as well as protection from further photodamage. Topical tretinoin has been shown fo partially reverse the clinical and histological changes induced by the combination of sunlight exposure and chronological ageing. A formulation of tretinoin in an emollient cream (Retinova™ Renova®). developed speciiically for the treatment of photodamaged skin, has heen extensively investigated in multifenlre. double‐blind trials and has been shown to produce significant improvement within 4–6 months of daily use, compared witb vehicle alone, as part of a regimen including sun protection and moisturizer use. Histological changes in the epidermis and dermis noted after 12 months suggest tretinoin repairs photodamage by reconstitution of the rete pegs, repair of kcratinocyte ultrastructural damage, more even distribution of melanocytcs and melanin pigment, deposition of new papillary dermal collagen, and Improvements in vasculature. Alpha‐hydroxy acids (AHAs) have also been widely used for therapy of photodamaged skin, and these compotinds have been reported lo normalize hyperkeratlnization and increase viable epidermal thickness and dermal glycosaminoglycans content. The single randomized controlled study now available appears to substantiate AHA efficacy and safety. In summary, recent work has substantially elucidated the ageing processes that alTect the skin and has demonstrated that many of tbe unwanted changes can be improved by topical

ISSN:0007-0963    

DOI:10.1046/j.1365-2133.1996.d01-1088.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SUMMARYCD44 is the major human cell surface receptor for hyaluronate and functions in a diverse range of physiological processes. Alternative splicing of a single gene generates a lamily of splice variants (CD44v1‐10) in addition to the standard isoform. CD44H. Expression of CD44. particularly CD44v6. has heen descrihcd to correlate with metastasis formation in various tumours, although evidence in malignant melanoma is inconclusive. In this study, we explored the immunohisto‐chemical pattern of CD44 expression in a range of melanocytic lesions using a panel of monoclonal antibodies raised to CD44H and the variants v 3, v4/5. v6and v8/9. Skin biopsies of 106 lesions from 100 patients were assessed and included benign and dysplastic naevi. melanoma in situ, malignant melanomas in horizontal and vertical growth phase, and cutaneous and lymph node metastases. CD44H was highly expressed in benign and dysplastic naevi and in melanomain situ.However, expression within melanomas diminished with increasing invasiveness. and the pattern of expres‐sion observed correlated significantly with the growth phase of the lesion rather than its Brcslow thickness. CD44 splice variants were not detected in any lesions. These results suggest a possible role for downregulation of CD44H in modulating the biological behaviour of malignant mel

ISSN:0007-0963    

DOI:10.1046/j.1365-2133.1996.d01-1089.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SUMMARYGlycoprotein Ilb‐IIIa (integrin alpha lib beta3) is an adhesive receptor involved in platelet aggregation and adhesion to the extracellular matrix. Previous.studies showed the presence of IIb‐IIIa‐like glycoproteins on cells of melanoma cell lines and on cells of lymph node metastases. This study evaluates the presence of glycoprotein IIb‐IIIa subunits on cells of primary cutaneous malignant melanomas wilh (n= 4) and without (n= 9) metastases over a period of 6 years and on naevus cells (n= 4). Monoclonal antibodies directed against the subunits of the glycoprotein IIb‐IIIa receptor were used on paraffin‐embedded sections and evaluated by means of immuno‐histochemistry. The giycoprotein lib subunit was exclusively present on cells of metastatic melanomas. It was not found on non‐metastatic melanomas or benign melanocytes. These data favour the role of the integrin receptor glycoprotein IIb‐IIIa in the metastatic behaviour of ma

ISSN:0007-0963    

DOI:10.1046/j.1365-2133.1996.d01-1090.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SUMMARYSeveral studies have indicated that extracellular matrix (ECM) proteins can influence melanocyte behaviour in vitro. However. Ihe choice of medium is known to have a profound effect on meianocyte behaviour and it is currently difficult to ascribe which reported effects are due to ECM proteins and those which are attributable to the medium used in these different studies. The purpose of this study was to learn more about the influence of ECM proteins on melanocyte function by examining a range of cell‐derived and individual ECM proteins for their impact on melanocyte tyrosinase activity in cells cultured under conditions of varying mitogenic drive. We found that ECM derived from human dermal fibroblasts. bovine endothelial cells and a human endothelial cell line as well as collagen I. collagen IV. fibronectin. and to a lesser extent laminin. were all capable of increasing tyrosinase activity in cultures of normal melanocytes. Effects of these ECM were seen most consistently in media with relatively few mitogens, for example ECM proteins influenced melanocyte morphology and this was seen most readily in cells cultured in medium without any mitogens (which ordinarily falls to support melanocyte survival). This study illustrates that ECM proteins can influence melanocyte morphology, proliferation, and tyrosinase activity in vitro and supports a possible role of ECM proteins in the regulation of melanocyte functionin viv

ISSN:0007-0963    

DOI:10.1046/j.1365-2133.1996.d01-1091.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SUMMARYThere has been considerable interest in the potential role of growth fctclors in the initiation and development of cutaneous malignant melanoma (CMM). Platelet‐derived growth factor (PDGF) has been shown to be secreted by melanoma cell lines and by metastatic melanomain vivo.PDGF also has been reported to stimulate the development of tumour stroma and new blood vessels. We studied the expression of PDGF and its receptors by both immunohistt)chcmistry (IHC) and in situ hybridization (ISH) in primary and metastatic melanoma and in normal skin specimens. Cryostat sections were incubated with35S‐labelled riboprobes and antibodies for PDGF‐AA. PDGF‐alpha receptor. PDGF‐BB and PDGF‐beta receptor. Both primary and metastatic melanoma exhibited significant expression of PDGF‐AA. PDGF‐BB and PDGF‐alpha receptor by both IHC and ISH. compared with only background expression in normal skin. We did not observe expression of PDGF‐beta receptor in melanoma. Our results suggest that PDGF may function as an autocrine growth factor, as well as an angiogenesis factor, in CMM tumour development. This expression of the PDGF‐alpha receptor rather than the beta receptor may be uniqu

ISSN:0007-0963    

DOI:10.1046/j.1365-2133.1996.d01-1092.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SUMMARYTo elucidate involvement ol protcinascs in malignancy of keratinocytes. expression ol catbepsin B, a cysteine proteinase. and catbepsin D. an aspartic proteinase. was ascertained in lormalin‐lixed paraffin‐embedded specimens of nortnal skin, squamous cell carcinoma (SCC). Bowen's disease, seborrboeic keratosis and basal cell carcinoma (BCC). Presence of procalbepsin B and an intermediate form of catbepsin D was coiilirmed by Westerti blolling and enzytne activity analysis. Cathepsin B stained more Intensely In SCC tumour cells tban in normal epidermis: staining patterns were diffuse, grantilar or botb. Diflusc and granular patterns (procatbcpsin B and mature enzyme, respectively) appeared in inner and outer parts of tumour islands, respectively. Five of 20 cases of Bowen's disease sbowed diffuse enhanced catbepsin B expression: 20 cases of seborrhoeic keratosis or BCC did not. Cathepsin D stained intensely in tumour cells of half the SCC cases. The staining manner and distribution of cathepsins B and D was similar in the cytoplasm of cancer cells. No enhanced staining of cathepsin I) was seen in any cases of Bowen's disease, seborrhoeic keratosis. or BCC. Coexistence and localization of active mature forms of cathepsins B and D suggests that cooperation between tbe two enzymes may play an important part in invasion of

ISSN:0007-0963    

DOI:10.1046/j.1365-2133.1996.d01-1093.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SUMMARYHistological interpretation of frozen sections made during Mohs' micrographic surgery may be difficult, depending on the morphological and staining characteristics of the tumour and on tbe nature of the associated inllammatory inliltrate. We have employed an adaptation of micrographic surgery in which horizontal, formalin‐tixed. paraflin‐embedded sections were used to improve histological assessment in the excision of 18 non‐melanoma skin tumours in which frozen sections had been or were likely to be unsatisfactory. We describe our experience of this method in the management of squamous cell carcinomas (11). extramammary Paget's disease (two), microcystic adnexal cell carcinomas (two), dermatotibrosarcoma protuberans (two), and primary cutaneous neuroendocrine carcinoma (Merkel cell carcinoma) (one). The use of horizontal paraffin‐embedded sections lengthens the duration of the procedure but facilitates accurate assessment of histological sections in selected

ISSN:0007-0963    

DOI:10.1046/j.1365-2133.1996.d01-1094.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SUMMARYSeborrhoeic keratosis (SK) is a benign epidermal tumour with a varying degree of pigmentation. We have recently demonstrated that endothelin‐1 (ET‐1) is a strong keratinocyte‐derived mitogen and melanogen for human melanocytes in UVB‐induced melanosis. To clarify the role of ET‐1 in hyperpigmentation in SK, we have used immunohistochemistry and reverse transcriptionpolymerase chain reaction (RT‐PCR) to see whether the production of ET‐1 is accentuated in SK. Immunohistochemical analysis in SK (n= 7: acanthotic and deeply pigmented types) revealed marked immunostaining with anti‐ET‐1 in almost all basaloid and basal cells as compared with definite staining confined to basal cells in the perilesional normal controls. In parallel. RT‐PCR of ET‐l mRNA demonstrated accentuated expression of ET‐1 transcript in SK (n= 4) in comparison with that in the perilesional normal controls, accompanied by a similarly accentuated expression of tyrosinase mRNA. These findings suggest that ET‐1 plays a part in the hyp

ISSN:0007-0963    

DOI:10.1046/j.1365-2133.1996.d01-1095.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SUMMARYThe term ‘jingry back syndrome’ (ABS) was coined by Mitchell in 197S. It was.stated that a strong positive patch test reaclion could create an ‘angry back’ which becomes hyperretictiye to other patch test challenges. The present study investignled whether the ABS is a generalized state of hyper‐reactivity of skin, whether it is a localized hyper‐reactivity of skin. i.e. only in lhe close proximity to a strong patcli test reaction, whelhcr it is an individual specilic phenomenon and if ABS is a reproducible phenomenon. The studies failed lo demonstrate any generalized or localized change in the reactivity of the skin. This lell the possibility that ABS might be a rare, and individual‐specilic phenomenon. However, even in the subjects who had previously been diagnosed as having ABS we failed to reproduce t

ISSN:0007-0963    

DOI:10.1046/j.1365-2133.1996.d01-1096.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

SUMMARYPivalone®/tixocortol pivalate commonly yields positive reactions in the patch test series. The clinical relevance of these positive reactions was investigated in more detail. In the standard patch test series 5.6% (73 of 1306) ofthe patients were positive to corticosteroids. 5.2% to 0.1% tixocortol pivalate in ethanol (Pivalone® nasal spray diluted 1:10) and 2.3% to 1% hydrocortisone butyrate in ethanol. Some ofthe patients were tested in parallel with Pivalone® and 1% tixocortol pivalate in petrolatum. The former test reagent yielded some false‐positive reactions, whereas with the latter, some allergic responses were missed. Intradermal tests with the succinate esters of hydrocortisone, methylprednisolone and prednisolone were performed with 52 patients positive to Pivalone®. Of these 76.9% (40 of 52) were positive in the intradermal tests; 38 to hydrocortisone. 35 to methylprednisolone and 30 to prednisolone. Twelve patients who had been positive in the intradermal tests were challenged orally with corticosteroids and they all showed positive reactions to hydrocortisone, methylprednisolone or prednisolone. The patients developed localized reactions at the sites of previous eczema or positive skin tests or diffuse erythema or exanthema. The oral doses of hydrocortisone eliciting positive delayed skin reactions ranged from 20 to 200 mg. Reactivity to tixocortol pivalate is closely related to sensitivity to hydrocortisone, methylprednisolone and prednisolone, but high oral doses of these corticosteroids may be required to produce allergic sym

ISSN:0007-0963    

DOI:10.1046/j.1365-2133.1996.d01-1097.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY