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Hernández‐Martín, A.; González‐Sarmiento, R.; Unamuno, P.DE
doi: 10.1046/j.1365-2133.1999.03098.xpmid: 10583107
X‐linked ichthyosis is a genetic disorder of keratinization characterized by a generalized desquamation of large, adherent, dark brown scales. Extracutaneous manifestations include corneal opacity and cryptorchidism. Since 1978 it has been known that a deficit in steroid sulphatase enzyme (STS) is responsible for the abnormal cutaneous scaling, although the exact physiological mechanism remains uncertain. The STS gene has been mapped to the distal part of the short arm of the X chromosome. Interestingly, this region escapes X chromosome inactivation and has the highest ratio of chromosomal deletions among all genetic disorders, complete deletions having been found in up to 90% of patients. Diagnosis of patients with X‐linked ichthyosis and female carriers is based on biochemical and genetic analysis. The latter currently seems to be the most accurate method in the majority of cases.
Banfield, C.C.; Dawber, R.P.R.
doi: 10.1046/j.1365-2133.1999.03099.xpmid: 10583108
In this review, the current state of knowledge concerning nail melanoma is summarized. The pathogenesis, histological findings, clinical presentation, treatment and prognosis of this rare form of cutaneous melanoma are discussed. Important clinical clues to the early diagnosis of nail melanoma are highlighted and recommendations to improve the management of patients are suggested.
Cox, N.H.; Eedy, D.J.; Morton, C.A.
doi: 10.1046/j.1365-2133.1999.03100.xpmid: 10583109
These guidelines for management of Bowen's disease have been prepared for dermatologists on behalf of the British Association of Dermatologists. They present evidence‐based guidance for treatment, with identification of the strength of evidence available at the time of preparation of the guidelines, and a brief overview of epidemiological aspects, diagnosis and investigation.
Hofmann, B.; Stege, H.; Ruzicka, T.; Lehmann, P.
doi: 10.1046/j.1365-2133.1999.03101.xpmid: 10583110
The clinical efficacy and tolerability of the topical receptor‐selective retinoid tazarotene in the treatment of congenital ichthyoses was investigated. Twelve consecutive patients with different forms of congenital ichthyosis were enrolled in an open, non‐randomized, intraindividually controlled, half‐side pilot study. Diagnoses were X‐linked recessive ichthyosis, non‐erythrodermic autosomal recessive lamellar ichthyosis, autosomal dominant ichthyosis vulgaris and ichthyosis bullosa of Siemens (IBS). Tazarotene 0.05% gel was applied unilaterally daily on a defined body area measuring 10% of the body surface area. The contralateral side was treated with an ointment containing 10% urea. After 14 days, application frequency was reduced to three times a week, and stopped after another 2 weeks. The follow‐up period was 3 months. Reduction in scaling and roughness was used to assess the clinical response in the tazarotene‐treated area compared with the control area. Clinical and laboratory assessments were performed every 14 days during the trial. Unilateral improvement in favour of the tazarotene‐treated side was observed in nine of 12 patients (75%). Four patients (33%) achieved an excellent response and four (33%) achieved a good response. No therapeutic effect was seen in patients with IBS. The remission persisted during the reduction phase and after discontinuation for up to 2 months. Local irritation in three patients was the only side‐effect detectable. Short‐term topical application of tazarotene 0.05% gel is a very effective and well‐tolerated treatment modality in different forms of congenital ichthyoses and may be an alternative to systemic retinoid therapy.
Kawakami, T.; Saito, R.; Takahashi, K.
doi: 10.1046/j.1365-2133.1999.03102.xpmid: 10583111
Disseminated superficial porokeratosis (DSP) consists of multiple small lesions of porokeratosis. Although the pathogenesis of DSP remains unclear, localized cloning of abnormal epidermis has been hypothesized. Malignant cutaneous neoplasms, especially Bowen's disease, have been frequently reported in DSP. Immunopositive p53 has been demonstrated in a variety of human malignant tumours, and its role in oncogenesis and tumour progression is thought to be important. p21Waf1/Cip1 is thought to mediate the signal of p53 induced by DNA damaging agents to arrest the cell cycle. To clarify the role of p53 and p21Waf1/Cip1 in Bowen's disease and DSP, we analysed 12 cases of Bowen's disease and eight cases of DSP by immunohistochemistry. In five of the 12 Bowen's disease patients and two of the eight DSP patients, positive p53 staining was detected. In contrast, whereas p21Waf1/Cip1 overexpression was detected in all Bowen's disease patients, it was not seen in DSP. The present data suggest that p53 immunostaining provides relevant information concerning the pathogenesis of Bowen's disease and DSP. Furthermore, high p21Waf1/Cip1 expression appears to be a useful indicator of tumour activity in Bowen's disease.
Fujino, M.; Ohnishi, K.; Asahi, M.; Wang, X.; Takahashi, A.; Ohnishi, T.
doi: 10.1046/j.1365-2133.1999.03103.xpmid: 10583112
To examine whether protein kinase C (PKC) and A (PKA) contribute to WAF1 induction by ionizing radiation (IR) in cultured human melanomas, the effect of PK inhibitors 1‐(5′‐isoquinolinesulphonyl)‐2‐methylpiperazine dihydrochloride (H7), bisindolylmaleimide (GF) and N‐[2(p‐dromocinnamylamino)ethyl]‐5‐isoquinolinesulphonamide (H89) on IR‐induced WAF1 accumulation was analysed by Western blot analysis. Gamma‐ray‐induced accumulation of WAF1 showed a peak at 6 Gy in all the cell lines. After γ‐ray irradiation of 6 Gy, a peak of WAF1 accumulation was observed at 6 h in SK‐Mel‐26, G361 and HM6KO cells, and at 3 h in MeWo cells. In MeWo and SK‐Mel‐26 cells, the X‐ray‐induced WAF1 accumulation was decreased by PK inhibitors, GF (PKC inhibitor) or H89 (PKA inhibitor); this did not occur in G361 and HM6KO. In all the cell lines, accumulation of WAF1 induced by X‐ray irradiation was suppressed by H7 (PKC and PKA inhibitor). In addition, polymerase chain reaction–single strand conformational polymorphism analysis detected no aberrations in the p53 gene of the four cell lines used. These results suggest that IR‐induced WAF1 expression involves PKC and/or PKA activity depending on cell type.
doi: 10.1046/j.1365-2133.1999.03104.xpmid: 10583113
Fibronectin, laminin and tenascin play an important part in the assembly of the extracellular matrix and the interaction of cells with it. In this study, changes in their expression and distribution associated with tuberous sclerosis are reported. Fibroblasts from three different tuberous sclerosis skin lesions (forehead plaque, neck fibroma and ungual fibroma) secreted more fibronectin and tenascin into their culture medium than did normal skin fibroblasts. Immunohistochemistry and flow cytometry showed that cells from an ungual fibroma which secreted most of each of these glycoproteins also retained more of them, associated mainly with the cell surface and a perinuclear area. Laminin was also produced by all fibroblasts but only in those from the neck fibroma was more both secreted and retained. The proportions of fibronectin/laminin/tenascin secreted by the skin lesion fibroblasts were markedly different from normal. The results suggest that the characteristic tissue hardening of skin lesions in tuberous sclerosis may result, at least in part, from differences in the expression and distribution of these critical components of the extracellular matrix and its consequent abnormal assembly.
doi: 10.1046/j.1365-2133.1999.03105.xpmid: 10583114
Hair follicles develop or regress in accordance with the hair cycle. In this study, we partially characterized fibrillar type I collagen, the predominant component in the dermis, at two stages of the hair cycle: anagen and telogen. Skin samples were obtained from the backs of two groups of 11‐week‐old C3H mice: one at anagen stage induced by shaving and the other at telogen stage. The amount of neutral salt‐soluble (newly synthesized) collagen obtained from anagen skin was about twofold that from telogen skin, while the level of acid‐soluble collagen was not significantly different between the two groups. The degree of lysine hydroxylation of pepsinized type I collagen obtained from anagen skin was significantly higher than that in telogen (5.0% higher in α1 chain, and 15.6% higher in α2 chain). Proline hydroxylation at the anagen stage was also slightly higher than in the telogen stage. Two major collagen cross‐links were found in both groups of skin; dehydro‐hydroxylysinonorleucine and dehydro‐histidinohydroxymerodesmosine. The concentration of the latter, a complex tetravalent cross‐link, was significantly lower in anagen skin when compared with telogen skin (mean ± SD 0.64 ± 0.07 vs. 0.78 ± 0.06 mol/mol collagen). The former showed no significant difference between the two groups. In addition, a significant amount of lysyl‐aldehyde (a cross‐link precursor) was found in anagen (0.16 ± 0.02 mol/mol collagen), while it was 0.12 mol/mol collagen in telogen. These results indicate that the remodelling of collagen is more active in anagen skin than in telogen, and that characteristic post‐translational modifications of dermal collagen seen in anagen may play a part in facilitating an environment around hair follicles for their migration and growth.
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