摘要:

summaryHemidesmosomes are frequently rudimentary in junctional epidermolysis bullosa (JEB), and JEB keratinocytes display abnormal attachment to the substrate in culture. Our aim was to determine whether this abnormality reflects defective hemidesmosome synthesisin vitro.Keratinocytes from five JEB patients were cultured under standard conditions. Control cultures, from four healthy males, three patients with dystrophic EB (DEB), and one patient with the simplex variant (EBS), were also examined. Post‐confluent cultures were processed for transmission electron microscopy. Hemidesmosome‐like structures were counted in electron micrograph montages. The number of hemidesmosome‐like structures in JEB cultures (0.97±0.57, per 10±m of basal cell membrane) was approximately 17% of the value for normal controls (5.81±3.08,P<0.02). The values for EBS (3.72) and DEB (3.28±1.44) were not statistically different from normal controls. In addition hemidesmosome‐like structures in JEB cultures were morphologically ill‐defined, compared with those from controls. This correlated with the loose apposition between JEB keratinocytes and the substrate, which appeared tight in controls. JEB keratinocytes continue to expressin vitroa major phenotypic abnormality which characterizes the diseasein vivo. Therefore, this model should prove useful in studies determining the pathogenesis and possible new trea

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1990.tb01840.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

summaryThe effects of α‐melanocyte stimulating hormone (α‐MSH) were studied on levels of cyclic adenosine 3′,5′‐monophosphate (cAMP), melanin content and response to ultraviolet radiation (UVR) in cultured human melanocytes (HuMC). ForeskinHuMC were cultured in a hormone‐supplemented system not dependent on the presence of phorbol esters. Following addition of α‐MSH (10‐6m) there was a rise in cAMP levels maximal between 5 and 15 min to 9.4±3.2 pm/ 105cells, while control levels were 3.6±0.7pm/105cells. After 7 days’culture in the presence of ±‐MSH (10‐8‐10‐6m) the melanin content increased by only 35%, whereas Forskolin (10‐5m) induced a 9.5‐fold rise in cAMP after 5 min and a 10.9‐fold rise in melanin content after 7 days. When HuMC were irradiated daily for 6 days with UVR (Helarium fluorescent lamps emitting 20% UVB, 80% UVA) melanin content rose 2.7‐fold (SE0.3). This was unchanged or slightly reduced in the presence of α‐MSH (10‐8‐10‐6m). Parallel observations on Cloudman S91melanoma cells showed that α‐MSH caused only an 80% increase in melanin content after 4 days. The rise in melanin content induced by three daily UV‐irradiations (2.4‐fold, SE0.5) was unchanged by α‐MSH (10‐8‐10‐6m). Although α‐MSH induces a small rise in cAMP in HuMC this does not result in melanogenesis, and the

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1990.tb01841.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

summaryImmunolocalization studies using the strepavidin/biotin peroxidase system were used to identify epidermal growth factor receptors in 10 samples of normal skin, 13 seborrhoeic warts (SW), five lesions of Bowen's disease (BD), 11 solar keratoses (SK), 22 basal cell carcinomas (BCC) and five squamous cell carcinomas (SCC). The intensity of cell membrane staining was assessed using the 10‐cm visual analogue scale technique and the results analysed using non‐parametric statistics. The cell membranes in BCC showed significantly less intense staining when compared to normal epidermal cells (P<0.001) and the constituent cells of SW (P<0.0001), SK (P<0.001), BD (P<0.01), and SCC (P<0.001). Classification of the specimens into normal, benign, premalignant and malignant indicated that cell membranes of malignant tumours showed significantly less staining than the other groups (P<0.001). The observed reduction in the epidermal growth factor receptors in malignant tumours may be due to occupation and down regulation in response to autocrine secretion of growth fact

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1990.tb01842.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

summaryThe existence of β‐adrenoceptors on intact cells of the human malignant melanoma cell line A‐ 375 was investigated using the binding properties of the tritiated radioligand (‐)‐[3H]CGP‐ 12177, a hydrophilic non‐selective β‐adrenoceptor antagonist. Displacement experiments of the radioligand from its binding site were performed with antagonists and agonists to determine the β‐adrenoceptor subtype selectivity. The binding of (‐)‐[3H]CGP‐12177 was saturable, of high affinity (Kd= 0.025 nmol/1,n= 12) and was rapid and readily reversible. The maximal number of binding sites (Bmax) was 33.5 ± 1.9 fmol/107cells or 2018 ± 114 receptors per cell. β‐adrenoceptor antagonists inhibited binding of the radioligand with monophasic displacement curves. IC50values were (nmol/l): propranolol (non‐selective) 2.82, alprenolol (non‐selective) 2.0, ICI 118,551 (β2‐selective) 3.5 and bisoprolol (β1‐selective) 2200. Agonists inhibited binding in the order of potency of isoprenaline>adrenaline>noradrenaline. It is concluded that cells of the melanoma cell line A‐375 contain a ho

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1990.tb01843.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

summaryThe expression of integrin cell surface receptors in normal skin and their synthesis and molecular structure in keratinocyte cultures was investigated. The reactivity of four different polypeptides of the integrin family (α2‐,α3‐,α6‐ and β1‐chains) was demonstrated in the basal cell layer of normal epidermis. Studies of labelled keratinocyte cell lines showed that the polypeptides were expressed as α2β1, α3β1and α6β4integrins. Only the α6β4integrin showed polarization towards the basement membrane attachment site of basal layer keratinocytes, and was preferentially expressed at microvillous projections. In contrast, α2β1and α3β1integrins were equally expressed throughout the bas

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1990.tb01844.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

summaryThe initial lymph vessels, the lymph capillaries and precollectors, are difficult to detect in normal skin using routine histological methods. A method is described in which specimens of the skin are fixed in an expanded condition. In 1.05 μm thick plastic‐embedded sections the dilated lymph vessels of the skin can be demonstrated. The dermal lymph vessel network can be seen following the subepidermal injection of a coloured solution. The endothelial cells and subendothelial fibrous network can be examined using electron microsco

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1990.tb01845.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

summaryOne hundred women who presented with diffuse alopecia, were quantitatively evaluated for hair variables and compared with 20 controls. Fifty were selected for biochemical and haematological investigations, 44 of whom also underwent endocrine evaluation. Compared to controls, significant changes in hair values were found in the frontal area of all subjects, while 84% had significant changes in the occipital area. A biphasic distribution of hair diameter was evident in subjects who had percentages of vellus hair and telogen hair ≤30 mm in length that were above the control ranges. No significant difference between the mean hormonal values of women with diffuse alopecia and controls could be found. No correlation between hair values and individual or combined hormonal levels could be established. In 18 subjects (40.9%) hormonal values were within the control ranges and these apparently normal findings were often associated with adverse hair profiles. A raised dihydrotestosterone was found in 13 subjects (29.5%) and was the most frequently elevated androgenic finding. Seventeen (34.0%) had changes in iron metabolism, while in 36 (72.0%) serum ferritin levels were below the lowest control value. All had a decrease in the percentage of hair in the anagen growth phase compared to controls. The hair changes were similar to those observed in genetic hair loss in men, a proven androgendependent condition. We propose that diffuse androgen‐dependent alopecia is the appropriate name to describe this condition in these wo

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1990.tb01846.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

summaryThe susceptibility of the skin to various irritants was investigated with the aim of determining the role of the barrier function of the stratum corneum, skin dryness and whether a history of atopic dermatitis (AD) was a factor. The transepidermal water loss (TEWL) was measured using an evaporimeter and skin hydration using a Corneometer and by visual scoring. The group with a history of AD (n= 20) had a lower pre‐exposure barrier function and a higher TEWL value following irritant exposure than the group with a history of allergic contact dermatitis (n= 18) and a control group (n= 18). Clinically dry skin was more susceptible than normal skin, though no difference was noted in the pre‐exposure barrier function. The increased susceptibility to irritants in those with a past history of AD was probably due to impaired barrier function. The increased susceptibility to irritants in those with a past history of AD was probably due to impaired barrier function and/or the presence of a dry s

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1990.tb01847.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

summaryThe effect of cyclosporin A (CyA) on the growth of cultured normal human keratinocytes and fibroblasts was studied. Tritiated thymidine incorporation per DNA content was used for shortterm studies (1–2 days) and cell counting for longer term studies (up to 14 days). CyA caused a dose‐ and time‐dependent inhibition of growth of both cell types. Keratinocytes (serum free, 70 μM Ca2) were more sensitive to CyA than fibroblasts (10% serum). For keratinocytes, at 2 days growth was 61% and 6% of controls with 3 and l0 μg/ml CyA, respectively, at 4 days growth was 51% with 1 μg/ml with complete inhibition at 10 μ/ml, and at 11 days growth was 58 and 39% with 0.1 and 1 μ/ml. For fibroblasts, at 4 days growth was 72 and 58% of controls with 10 and 30 μg/ml CyA, respectively, at 10 days growth was 76, 43 and 10% with 3, 10 and 30 μg/ml, and at 14 days growth was 41 and 11% with 3 and 10 μg/ml with complete inhibition with 30μg/ml. For keratinocytes the effect of 24 h of CyA on growth was reversible. Growth of keratinocytes was inhibited by 10% delipidized serum, and 1% serum had a small stimulatory effect, but the action of CyA was unaltered. We conclude that increasing the duration of exposure to CyA increases the concentration‐dependent growth inhibition. At therapeutic blood levels of CyA the growth of cultured keratinocytes but not fibroblasts is inhibited. The benefit of CyA in reducing the hyperproliferation of psoriasis may include a direct effect

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1990.tb01848.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

summaryTwelve cases were reviewed of squamous cell carcinoma of the nail bed, with emphasis on the aetiological role of human papillomavirus (HPV) infection and radiation damage. Using a hybridization technique, similar HPV genomes were detected in a uterine cervical neoplasia and a subungual squamous cell carcinoma in the same patient.

ISSN:0007-0963    

DOI:10.1111/j.1365-2133.1990.tb01849.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY