摘要:

SummaryGlutathione (GSH) performs several important biological functions, including quenching of reactive oxygen species, and protection of cells from toxic compounds such as quinones. The first step in the synthesis of GSH is catalysed by γ‐glutamylcysteine synthetase, an enzyme which is inhibited by cystamine and buthionine sulfoximine (BSO). In this study, we examined the possibility that the effect of hydroquinone (HQ) on pigmentation could be potentiated by inhibiting the production of GSH.In vitrostudies using melanoma cell lines demonstrated that both cystamine and BSO could potentiate the inhibitory effects of HQ on tyrosinase activity and melanin content. A synergistic decrease in hair pigmentation was observed when a combination of HQ (2 or 4%) and BSO (5%) was applied to the dorsal skin of C57BL mice. In black hairless guinea‐pigs, the application of HQ plus either BSO or cystamine resulted in a significant decrease in epidermal pigmentation when compared with any of the agents alone. The possibility exists that in the future a combination of HQ plus cystamine or BSO could be used to treat disorders such as melasma and post‐Inflammatory hyperpigmen

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1995.tb02660.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThe two main pathogenetic characteristics of atopic dermatitis (AD) are: (i) antigen‐dependent ‘specific’ reactivity, and (ii) altered non‐immimological ‘non‐specific’ reactivity. Our understanding of the role of non‐specific reactivity is hampered by the fact that methods available for its quantification are limited. The aim of the present study was to assess the usefulness of two parameters as quantitative measures of non‐specific skin reactivity in AD: (i) susceptibility to repeated epicutaneous exposure to an irritant (sodium lauryl sulphate, SLS), assessed by visual scoring and transepidermal water loss(TEWL) measurement, and (ii) reactivity to intracutaneously injected bioactive agents (codeine, FMLP, histamine, methacholine, substance P, trypsin), assessed by measurement of weal and flare size. These two parameters were tested in a group of AD patients, subdivided according to the severity of their dermatitis, and a control group. The visual score and TEWL after SLS exposure tended to be higher in the AD group than in the control group. Furthermore, visual score and post‐exposure TEWL were positively correlated with the dermatitis severity score. Weal size following injection of codeine, histamine and substance P, and flare size following injection of all agents, except methacholine, were significantly lower in the AD group than in the control group. Negative correlations were found between weal and flare sizes and the dermatitis severity score. These findings can be explained by down‐regulation of structures involved in weal and flare reactions. In conclusion, we propose that epicutaneous irritant susceptibility and reactivity to intracutaneous bioactive agents may be useful indicators of non‐specifi

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1995.tb02661.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryMany atopic dermatitis (AD) patients have exacerbations of their skin disease in winter. These exacerbations may be caused by non‐immunological ‘non‐specific’ factors, such as low sun exposure and low temperature. To date, the influence of season on non‐specific skin reactivity in AD has not been studied. The aim of the present investigation was to assess the influence of season on two skin parameters which may be used as quantitative measures of non‐specific skin reactivity in AD: (i) susceptibility to repeated epicutaneous irritant (sodium lauryl sulphate, SLS) exposure, and (ii) weal and flare responses to intracutaneous injection of bioactive agents (codeine, FMLP, histamine, methacholine, substance P, trypsin). Four of 16 AD patients had dermatitis which was more severe in November than in July. Susceptibility to SLS was increased in November, both in AD patients and in control subjects. AD patients were more susceptible to SLS than control subjects in both July and November, Pre‐exposure barrier function and skin hydration were reduced in November. The increased irritant susceptibility in November may be attributed to reduced barrier function, reduced skin hydration, and/or absence of the beneficial effects of ultraviolet light on cellular targets beneath the stratum corneurn, Flare responses to codeine, methacholine, substance P and trypsin were also increased in November compared with July, especially in AD patients. However, smaller Hares were observed in AD patients than in control subjects, in both July and November, Flare values were negatively correlated with dermatitis severity, probably because of down‐regulation. Weal responses did not show a clear seasonal variation. Hence, susceptibility to epicutaneous irritants and reactivity to intracutaneousty injected bioactive agents are parameters which may be used to monitor season dependent changes in non‐specifi

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1995.tb02662.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryAntibodies raised against fragments of synthetic peptides of human 5α‐reductase isoenzymes 1 (h5αrl) and 2 (h5αr2) were applied to paraffin sections of human skin (scalp, eyelid, lip, breast, scrotum).Immunoreactive sites were differentially distributed, in that h5αrl immunoreactivity was present in the nuclei of cells in the stratum germinativum (basal and lower portion of the spinous layer) of the epidermis, subepithelial tibroblasts, adipocytes, smooth muscle cells of the scrotal tunica dartos, basal cells of sebaceous glands, excretory duct cells of sweat glands, cells of the dermal papilla and fibrous and outer epithelial sheath of hair roots, as well as endothelial cells of small vessels and Schwann cells of cutaneous myelinated nerves. In contrast, immunoreactivity for h5αr2 was found in the cytoplasm of the cells of the spinous layer (and far less intensely in the basal layer) of the epidermis, subepidermal fibrocytes, and especially in subcutaneous adipocytes. Immunoreactivity was strongest in the non‐keratinized portion of the inner epithelial sheath and the cuticle of hair follicles, whereas other portions of the hair root were negative. Sweat glands were stained, whereas sebaceous glands showed only weak diffuse immunoreactivily. In mucoculaneous zones, salivary glands and conjunctival epithelium showed immunoreactive cells. Vascular endothelium displayed immunoreactivity only in the genital region. We present experimental evidence for a differential distribution of 5α‐reductase isoenzymes in human skin. This might reflect a diversity in the response of different areas of the skin to androgeni

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1995.tb02663.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryICAM‐3 is a newly recognized adhesion molecule, which is a member of the immunoglobulin supergene family of ICAMs. and has been shown to be identical with the CD50 antigen. Recent functional studies have shown that ICAM‐3 is a ligand for LFA‐1, and plays an important part in immune reactions. To date, very few data exist in the literature concerning its expression in the skin. In the present study, we investigated the expression of ICAM‐3 in normal skin and in 98 biopsy specimens of various inflammatory and neoplastic dermatoses. ICAM‐3 was found to be expressed by epidermal CD la+Langerhans cells, by cells of Langerhans cell hisliocytosis, by T and B lymphocytes infiltrating the dermis in cutaneous lymphomas and in a wide spectrum of inflammatory dermaloses. Epidermal keralinocytes were consistently negative: endothelial expression of ICAM‐3 was observed in six of the 48 cases. These results show that ICAM‐3 is constitutively and widely expressed by cells participating in inflammatory dermaloses (including Langerhans cells and T and B lymphocytes), and that it can be albeit rarely, induced on endothelial cells and dermal dendrocytes. These results highlight the important part that ICAM‐3 may play in cutaneous inflammatory and i

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1995.tb02664.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryBP180 is a 180kDa hemidesmosomal protein recognized by bullous pemphigoid (BP) and pemphigoid gestationis (PG) autoantibodies. Recent cloning and sequence analysis performed by our laboratory have revealed that BP180 is a transmembrane protein with a long extracellular collagen‐like region. A rabbit polyclonal antibody has been generated against a recombinant protein, designated GST‐NΔ1. containing a segment of the BP180 ectodomain. The resulting antiserum. RNΔ1 A, was shown to specifically react with BP180 on immunoblot, and labelled the extracellular region of the epidermal hemidesmosome on immunoelectron microscopy. A panel of normal and neoplastic human tissues were analysed by indirect immunofluorescence (IF) and RNΔ1A, to determine the distribution of BP180. A total of nine basal cell carcinomas (BCCs) and four squamous cell carcinomas (SCCs) of the skin were also studied. Intense IF staining was seen along the basement membrane zone (BMZ) of the epidermis, hair follicles, and the periphery of sebaceous gland lobules. The sebaceous lobules showed more intense staining in areas close to the duct, The epithelial BMZ of the following tissues also reacted with RNΔ1A: cornea, ocular conjunctiva, buccal mucosa. upper oesophagus, placenta (amnion placentum). umbilical cord and transitional epithelium of the bladder, The epithelium of the jejunum and ovary tailed to react with RNΔ1A, Staining of the BCCs and SCCs was variable. Five of six nodular BCCs showed some anti‐BP180 staining at the tumour‐stromal interface, although the level of staining was less intense than that observed in the overlying normal epidermis. All three morphoeic BCCs analysed in this investigation did not show any staining with RNΔ1A. Three of four SCCs showed weak staining at the tumour‐stromal interface. Thus, the tissue distribution of BP180 paralleled that of hemidesmosomes, and expression of this protein was found to be decreased or absent in cuta

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1995.tb02665.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThe monoclonal antibody UM4D4, assigned to the CDw60 cluster of differentiation, identities an epilope expressed on a subset of normal T cells, some malignant T cells, melanocytes, malignant melanoma cells and hyperproliferative psoriatic keratinocytes. CDw60 antibodies bind to the acetylated form of GD3gangliosides. These gangliosides have been implicated in the control of cellular proliferation. Because the acetylated form of GD3has been demonstrated in basal cell carcinomas, we determined whether the CDw60 epitope was expressed in basal cell carcinomas (n= 24) and squamous cell carcinomas (n= 2). Biopsies of these tumours were sectioned on a cryostat, and stained with anti‐CDw60 using a sensitive indirect immunoperoxidase technique. A mean of 74±4% (mean ± SEM) of the basal cell carcinoma cells expressed CDw60. In contrasl, CDw60 expression in normal skin was confined to melanocytes and a few scattered keratinocytes at the basal cell layer. CDw60 expression in basal cell carcinomas was highly upregulated at the tumour front in most of the lesions, whereas the squamous cell carcinomas showed uniform CDw60 expression in all ar

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1995.tb02666.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryVarious cell stimuli occur via activation of phospholipase A2, which hydrolyses polyunsaturated fatty acids from the sn‐2 position of membrane phospholipids, resulting in the formation of polyunsaturated fatty acids and lysophospholipids. The level of lysophospholipids is determined by the balance between phospholipase A2activity and the rate of catabolism of the lysophospholipids. One of the lysophospholipid classes, lysophosphatidylcholine, has been shown to stimulate certain leucocyte activities which are of importance for the induction and maintenance of inflammation. In addition, it has been demonstrated that phospholipase A2activity is increased in psoriatic skin.In the present study, we analysed the levels of lysophosphatidylcholine, by thin layer chromatography, in lesional psoriatic skin, uninvolved psoriatic skin and normal skin. The lysophosphatidylcholine content, expressed as μmol lysophosphatidylcholine/μmol phosphatidylcholine, was 1.55, 0.21 and 0.12% in lesional psoriatic skin, uninvolved psoriatic skin and normal skin, respectively. The level of lysophosphatidylcholine was significantly elevated in lesional compared with uninvolved psoriatic skin (P= 0.004) and normal skin (P= 0.002). The increased lysophosphatidylcholine levels in psoriatic skin indicate that the phospholipase A2activation is not accompanied by a corresponding increase in the activity of enzymes catabolizing lysoPC.If present in biologically active concentrations, lysophosphatidylcholine may contribute to the induction and maintenance of the inflammatory and immunological processes occurring in lesional psoriatic s

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1995.tb02667.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThe systemic absorption of topical hydrocortisone (HC) was quantified in seven patients with erythroderma, using the ratio of the areas under the curves for plasma concentration vs. time, following topical and intravenous administration. Over a period of 24 h. 19–93 mg of HC was absorbed systemically, corresponding to 4–19% of the total topical dose of 500 mg. Thus, topical HC therapy of erythroderma is accompanied by a pharmacologically significant systemic d

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1995.tb02668.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryKeratoderma with scleroatrophy of the extremities, also referred to as Huriez syndrome, is a rare, autosomal dominant condition, first described in 42 of 132 members of two families from northern France. The term clerotylosis was proposed because of the pseudosclerodermatous appearance of the hands and digits. The distinctive feature of this syndrome is the risk of the development of squamous cell carcinoma on affected skin. Since the initial description of this disease, three other families, and possibly a fourth, have been reported. In the present study, we reassessed the clinical, pathological and genetic data in 114 members of one of the two original families, of whom 27 were affected by this syndrome.

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1995.tb02669.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY