摘要:

SUMMARYSolar keratoses (SKs) or actinic keratoses are common dysplastic epidermal lesions which occur in pale‐skinned individuals who are chronically exposed to intense sunlight. Together with basal cell carcinomas and sqamous cell carcinomas, they constitute a major public health problem in such individuals.Reported SK prevalence rates range from 11 to 25% in various northern hemisphere populations, and amongst Australian adults the range is from 40 to 60%. In the only study to date reporting SK incidence data, 60% of subjects aged 40 years and over with SKs at baseline developed new lesions during 12 months of follow‐up, compared with only 19% of those who were lesion‐free on the first examination.Because existing epidemiological data on SKs are sparse, very little is known of their natural history, their role in carcinogenesis, or their preventability. In this review, current knowledge about the aetiology, diagnosis, and occurrence of SKs is discussed, as is the need for prospective studies in unselected communities. With accurate baseline data, public health authorities should be in a better position to determine the best preventive strategies, and to evaluate the effectiveness of these progr

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1994.tb08544.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryElastic microfibrils containing fibrillin are a part of the fibroreticular network of normal epidermal basement membrane. In dystrophic epidermolysis bullosa (DEB) at least one other fibroreticular component, anchoring fibrils, which contain type VII collagen, is known to be abnormal. We therefore questioned whether elastic microfibrils and fibrillin expression might also be abnormal in DEB. By indirect immunofluorescence, and pre‐embedding immunogold electron microscopy using a monoclonal antifibrillin antibody, we found no difference from control samples in either the quantity of the labelling or in the ultrastructural appearances of the immunolabelled fibrils in intact DEB skin. In areas of dermal‐epidermal separation, however, we observed a number of thin, fragmented sublamina densa wisp‐like structures, which still labelled for fibrillin despite lacking the typical ultrastructural features of normal elastic microfibril bundles. As a consequence of blistering in DEB, elastic microfibril bundles are disrupted, and fragmented microfibrils may still remain attached to the blister roofs. Many of these elastic microfibrils cannot be distinguished from rudimentary or altered anchoring fibrils on morphology alone, and might therefore account for misinterpretation of ultrastructural disorders of the dermal‐epidermal junction. We postulate that, in intact skin, elastic microfibrils might contribute to dermal‐epidermal adherence, in the absence of normalfunctioning anchorin

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1994.tb08545.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryThe monoclonal antibody LH7:2, which recognizes type VII collagen, is now used in the diagnosis and prenatal diagnosis of epidermolysis bullosa dystrophica. We constructed the expression vector which contains the cDNA fragment of type VII collagen. Western blot with LH7:2 was carried out with the resultant fusion proteins which overlap each other, and we found that reactivity is located in the central region of the N‐terminal non‐collagenous domain of type VII collagen, at a position 81 kDa upstream from the collagenous domain. This epitope mapping for LH7:2 may be useful in studying the role of type VII collagen in epidermolysis bullosa dystroph

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1994.tb08546.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryBecause the hair follicle is a highly hormone‐sensitive miniorgan, the role of hormones produced locally in the skin in the control of hair growth deserves systematic analysis. It has been shown previously that the potent steroid hormone 1,25‐dihydroxyvitamin D3(1,25‐D3) modulates growth and differentiation of keratinocytes via binding to a high‐affinity nuclear vitamin D receptor (VDR). In this study, we have examined thein situexpression of VDR during the murine hair cycle. VDR expression was detected immunohistochemically. To obtain defined stages of the murine hair cycle, hair growth was induced by depilation in C57 BL‐6 mice. In addition to the recognized VDR expression of outer root sheath keratinocytes, we detected VDR immunoreactive cells in the dermal papilla, the mesenchymal key structure of the hair follicle. Furthermore, VDR immunoreactivity in the nuclei of outer root sheath keratinocytes and in dermal papilla cells was stronger during anagen IV‐VI and catagen than during telogen and anagen I‐III. This suggests hair cycle‐associated changes in the expression of VDR, and points to a potential role for 1,25‐D3in hair follicle biology. Selected follicular cell populations may display hair cycle‐dependent sensitivity to

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1994.tb08547.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummarySites of previously unexposed buttock skin of eight human volunteers (skin type II) were treated daily for 3, 5, 8, or 10 days with suberythemogenic doses of solar‐simulated radiation (SSR) in the presence of a UVB sunscreen containing 5‐methoxypsoralen (5‐MOP) at 30p.p.m., or daily for 10 days with SSR+the same sunscreen without 5‐MOP. One week after cessation of treatment, these sites, together with a control unexposed site, were challenged with 2 minimal erythema doses (2 MED) of SSR. Biopsy samples were taken within 15 min of the challenge dose, and were incubated for 1 h in tritiated thymidine. UV‐induced DNA damage was measured indirectly by unscheduled DNA synthesis (UDS), and directly using a monoclonal antibody to thymine dimers, and automated image analysis. The level of pigmentation was assessed in sections in a semiquantitative fashion with Masson‐Fontana staining, and the number of layers in the stratum corneum was used to assess changes in epidermal thickness. Using the UDS and dimer measurements, the level of photochemoprotection afforded by 5‐MOP was determined from the reduction in the level of DNA damage observed. The photochemoprotection was expressed as a ratio of the 5‐MOP‐treated sites compared with the sites that did not receive 5‐MOP treatment.The onset of 5‐MOP photochemoprotection was shown to occur after three to five daily exposures, and became maximal after eight daily exposures. The onset of this protection coincided with increases in melanin and in stratum corneum thickness. In an extension of this study, it was found that following 10 daily exposures, 5‐MOP photochemoprotection declined at a rate of about 5% per week, and in spite of several cycles of epidermal cell replacement, some protection still persisted up to 14 weeks after the end of the tanning protocol. The sites treated with sunscreen without 5‐MOP showed negligible changes in melanin, stratum corneum thickness and levels of DNA damage. There was good correlation between the photochemoprotection endpoints of UDS and thymine dimer levels. The importance of 5‐MOP photochemoprotection in the risk‐benefit assessment of sunscreens us

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1994.tb08548.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummarySeven of 25 patients with cutaneous delayed‐type hypersensitivity to hydrocortisone had an immediate reaction following the intradermal injection of hydrocortisone sodium succinate. Using an ELISA method, we found that these patients had significantly increased levels of IgG antibodies to hydrocortisone when compared with normal blood donors (P<0.005) and nickel‐allergic patients (P<0.05). We suggest that these patients are at risk of developing type III and possibly type I reactions following the systemic administration of hydrocortisone and that, if needed, an alternative systemic corticosteroid should be used, for example betamethasone or dexamethas

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1994.tb08549.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryThe anatomy of the epidermis, dermis and subcutaneous tissues of the nail apparatus is distinct from that of non‐appendageal skin. Apart from the demonstration of the longitudinal configuration of the dermal‐epidermal junction of the nail bed, there have been no studies of the composition of the basement membrane zone of the nail apparatus. We obtained three human accessory digits, including one thumb, all of which had been amputated for cosmetic reasons, and were without known pathology. Specimens were stained with a battery of monoclonal and polyclonal antibodies which target normal basement membrane zone antigens, and studied by indirect immunoflourescence.This study demonstrated that the four distinct regions of the nail, namely the proximal nail fold, the nail matrix, the nail bed and the hyponychium expressed all the target antigens found in the normal non‐appendageal basement membrane. In particular, there was normal expression of the epidermal‐associated antigens, the 220‐and 180‐kDa bullous pemphigoid antigens, and the α6β4 integrin. There was also normal expression of the lamina lucida antigens LH39, GB3 and laminin. It is of interest that the dermal‐associated components, namely the 285‐kDa linear IgA antigen, the extracellular matrix glycoproteins chondroitin sulphate, type VII collagen and its closely associated proteins, and the poorly characterized antigen for LH24 and LH39 were all normally expressed.Fibronectin, which is not a normal basement membrane zone component, was diffusely expressed in the extracellular matrix, but did not accentuate the basement membrane zone. LHF2, an antibody raised against tenascin, which shows weak positive staining at the tips of dermal papillae in normal skin (unpublished data) diffusely stained the extracellular matrix and the tips of the dermal papillae of the nail matrix and hyponychium, but did not stain the basement membrane of the nail bed.These findings show that despite the numerous distinct features of epidermis, dermis and subcutis of the nail apparatus, the basement membrane zone has virtually identical antigen expression to that of the dermal‐epidermal junction elsewhere. The difference in LHF2 expression in the nail bed most likely reflects the different shape of the nail bed basement membrane, which is arranged in

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1994.tb08550.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryThe expression of cytokeratins and involucrin varies greatly in different epithelia, and this raises the possibility that detailed analysis of these epidermal proteins might provide a means of identifying various skin tumours. The present study was conducted to determine the immunohistochemical distribution of cytokeratins and involucrin in calcifying epithelioma of Malherbe, in order to elucidate the nature and differentiation of this tumour. To correlate the immunohistochemical profile with the most frequest histological patterns, we categorized the basophilic, transitional, shadow, and squamoid cells, and the shreds of keratin. Comparative studies with normal skin showed that the shadow and transitional cells corresponded to hair cortex cells, the squamoid cells to the outer root sheath, the basophilic cells adjacent to the stroma to the outermost cell layer of the outer root sheath between the lower permanent portion and upper transient portion of the follicles, and the basophilic cells adjacent to the transitional cells to the hair matrix. The expression of cytokeratins in most shreds of keratin was similar to that in squamoid cells. Calcifying epithelioma was, therefore, shown to be composed of tumour cells differentiating into both the hair cortex and outer root sheath. These tumour cells were differentiated from basophilic cells, which showed the same staining patterns as the outermost cell layer of the outer root sheath between the lower permanent portion and upper transient portion of the hair follicles, supporting the hypothesis that the keratinocytes in the outermost cell layer can differentiate into the transitional portion of the follicle and anagen hair.

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1994.tb08551.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummarySixty‐two skin samples from patients with a variety of benign disorders (20 cases of psoriasis, 14 cases of chronic dermatitis, 11 seborrhoeic keratoses, 11 cases of lichen planus), and seven normal skin samples, were stained immunohistochemically with a polyclonal antibody (CM‐1) to p53, and a monoclonal antibody to Ki67, using the avidin‐biotin complex method, p53‐positive keratinocytes could be found in most of these lesions. The percentage of p53‐positive cells was, however, far lower than usually seen in p53‐positive malignant tumours. No p53 reactivity was observed in the normal skin samples. Variable Ki67 reactivity was observed in all skin samples. Overall, the number of Ki67‐positive cells was higher in skin samples in which the proportion of p53‐positive cells was high (>0.5% of total epidermal cell population) (P=0.004). This also applied separately to psoriatic and non‐psoriatic lesions (P=0.028 andP=0.033, respectively). In cases with>10% of Ki67‐positive cells, there were significantly more mitoses (P<0.001). This association applied to both psoriasis and the other lesions studied (P=0.024 andP<0.001, respectively). The results show that immunohistochemically detectable accumulation of p53 is a frequent finding in non‐neoplastic skin lesions. As p53 positivity was associated with the proliferation marker Ki67, the accumulation of p53 is possibly a response to an increased proliferation rate of the keratinocytes in these skin diseases, or alternatively it may be asso

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1994.tb08552.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

SummaryProgrammed cell death (PCD) in normal human skin tissues was studied by usingin situspecific labelling of fragmented DNA. This labelling method clearly stained the nuclei of Henle's layer in the bulb of the anagen hair follicle in serial sections, and the nuclei of the inner root sheath cuticle cells and Huxley's layer cells showed positive staining in the upper part of the hair follicles. This staining pattern was consistent with the sequence of keratinization in the three layers. The nuclei of differentiated cells located at the centre of the sebaceous glands, and those of the granular keratinocyte layer, were also stained. These findings suggest that PCD might play a key role in the terminal differentiation of the epidermis and epidermal appendages.

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1994.tb08553.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY