端粒、端粒酶与皮肤病

本文介绍了端粒和端粒酶的结构、分子生物学作用，尤其与细胞增殖及永生化的关系，进而重点介绍了端粒酶与皮肤肿瘤及慢性炎症性皮肤病（如异位皮炎、银屑病）的关系，指出端粒酶活性的测定，有可能为探索某些皮肤病的发病机制、治疗等提供新思路。     

端粒,端粒酶与皮肤

端粒作为细胞线性染色体末端的一组重复ＤＮＡ序列,对维持染色体的稳定和细胞寿命至关重要,其长度的维持有赖于一种ＲＮＡ酶即端粒酶的存在。近年来许多学者对人类端粒和端粒酶的研究表明,端粒和端粒酶是决定基因扩增和稳定的主要因素而调控着细胞增殖活性和细胞寿命。介绍了人类端粒、端粒酶的研究进展及其与皮肤、皮肤病的关系。     

端粒、端粒酶及其在临床上的意义

端粒是真核细胞线性染色体末端的DNA重复序列和特异结合蛋白的复合体，对维持染色体的稳定性和完整性具有重要作用。端粒酶是一种由RNA和蛋白质组成的核糖核蛋白复合体，具有逆转录酶的活性。许多研究表明，端粒和端粒酶系统调控着细胞增殖活性和细胞寿命。本文介绍了端粒、端粒酶的研究进展以及其在某些皮肤病和肿瘤发生与发展中的作用。     

端粒、端粒酶与皮肤

端粒作为细胞线性染色体末端的一组重复DNA序列,对维持染色体的稳定和细胞寿命至关重要,其长度的维持有赖于一种RNA酶即端粒酶的存在。近年来许多学者对人类端粒和端粒酶的研究表明,端粒和端粒酶是决定基因扩增和稳定的主要因素而调控着细胞增殖活性和细胞寿命。介绍了人类端粒、端粒酶的研究进展及其与皮肤、皮肤病的关系。     

端粒酶及其抑制剂在皮肤肿瘤诊治中的作用

端粒是真核细胞染色体末端独特的蛋白质 -DNA结构 ,是调控细胞寿命、发育和分化的生物钟。端粒酶是由RNA和蛋白质组成的核蛋白逆转录酶 ,与细胞永生化和癌变有关。研究发现 85 %～ 90 %人肿瘤细胞表达端粒酶活性 ,正常人体细胞无端粒酶表达 ,因此端粒酶有望成为肿瘤诊断的标志物及肿瘤治疗的新靶点。目前人们正在探讨将抑制端粒酶的表达作为肿瘤基因治疗的一种策略     

端粒酶在皮肤病学中的研究进展

端粒是位于真核生物线性染色体末端一段富含G的重复核苷酸序列 ,具有防止染色体端 -端融合、断裂 ,重组或降解等作用。端粒酶是一种核糖核蛋白酶 ,能以自身RNA为模板 ,逆转录合成端粒DNA重复序列并加到染色体末端 ,使端粒延长 ,从而延长细胞的寿命甚至使其永生化。研究表明端粒和端粒酶同细胞衰老以及肿瘤的发生发展有密切关系。现介绍了近几年端粒酶在皮肤肿瘤的发生 ,良性增生性及炎症性皮肤病等领域研究的新进展。     

端粒酶和肿瘤

端粒是真核细胞染色体末端的DNA重复序列和特异结合蛋白的复合体 ,能维持染色体的稳定和完整。端粒酶是由RNA和蛋白质组成的复合体 ,能以自身的RNA为模板合成端粒序列。端粒酶在肿瘤的发生和发展中具有重要的作用。以调节端粒酶为基础的基因治疗为抗肿瘤的研究开辟一条新途径。研究端粒酶的活性表达及其调节和作用机理 ,对肿瘤的发病机理、诊断和治疗有着重要的意义。     

端粒酶和肿瘤

端粒是真核细胞染色体末端的ＤＮＡ重复序列和特异结合蛋白的复合体，能维持染色体的稳定和完整。端粒酶是由ＲＮＡ和蛋白质组成的复合体，能以自身的ＲＮＡ为模板合成端粒序列。端粒酶在肿瘤的发生和发展中具有重要的作用。以调节端粒酶为基础的基因治疗为抗肿瘤的研究开辟一条新途径。研究端粒酶的活性表达及其调节和作用机理，对肿瘤的发病机理、诊断和治疗有着重要的意义。     

端粒酶在皮肤科领域的研究进展

端粒一端粒酶在细胞永生化及肿瘤发生中的作用已逐渐被人们所揭示。对近年来端粒酶在皮肤科领域的研究进展，包括皮肤恶性肿瘤、良性肿瘤、癌前病变、某些炎性皮肤病及正常皮肤、皮肤附属器中的表达进行了综述，并对以端粒酶为靶点的治疗在皮肤科领域的应用前景进行了展望。     

皮肌炎的皮肤表现及其意义

皮肌炎（dermatomyositis, DM）以累及皮肤、横纹肌为特征的自身免疫性结缔组织病。DM临床表现复杂多样,而直观或可触及的皮损有助于临床诊断与鉴别诊断,某些皮损与潜在的内脏损害、恶性肿瘤、实验室检查指标异常及预后有关,现就皮肌炎伴发的皮损及其意义进行概述……     

Malassezia yeasts and their significance in dermatology

Yeasts of the genus Malassezia belong to the normal microflora of the human skin. In addition they are known to cause a variety of skin diseases; the most frequent of which is pityriasis versicolor. Malassezia yeasts are also thought to be associated with seborrheic dermatitis, dandruff and Malassezia folliculitis. Recently the significance of Malassezia yeasts as a trigger factor for atopic dermatitis of the head and neck region has been pointed out. The role of the Malassezia yeasts in these different diseases has been controversial in the past and remains an issue because of difficulties in isolation, culture and differentiation of the organism. Thanks to molecular techniques, 10 species can actually be differentiated. The article presents the different Malassezia-associated diseases, their clinical picture, diagnosis and appropriate therapy. In addition the speciation of Malassezia is reviewed.     

The genodermatoses and their significance in pediatric dermatology

This article presents a detailed discussion of six genetic disorders with major cutaneous manifestations that might commonly be seen by the dermatologist or pediatrician. These include neurofibromatosis, tuberous sclerosis, xeroderma pigmentosum, incontinentia pigmenti, incontinentia pigmenti achromians, and Down's syndrome. The appearance of each disease at birth is described, and all manifestations of each entity are discussed in detail. Disorders with different inheritance patterns were chosen so that important genetic principles could be elucidated. The article concludes with a general discussion of genetic counseling, which draws upon the six genetic diseases for specific examples of important concepts.     

Gonococcal surface antigens and their significance for serotyping and vaccines

Outer membrane components of Neisseria gonorrhoeae play an important role in the initial steps of infection. Precise knowledge about the surface antigens is needed for the development of a serotyping system and of a vaccine against local and systemic gonorrhea. Structure, antigenicity, and function of the best-known membrane components, i.e., lipopolysaccharide, protein I, protein II, protein III, and pili, are discussed. Lipopolysaccharide is a strong immunogen and induces bactericidal antibodies, but is unsuitable for use as a vaccine because of its toxicity. Protein I and protein III are stable proteins, not subject to antigenic variation. Antibodies against protein I, which are able to kill N. gonorrhoeae, are detectable in the serum of patients with disseminated gonococcal infection. Protein II and pili are highly variable antigens with constant, very slightly immunogenic regions. To interrupt the pathomechanism of gonococcal infection at different stages, future vaccines should contain more than one surface antigen.     

Autoantibodies and their clinical significance in a black vitiligo population

The frequency of autoantibodies was determined in 70 black vitiligo patients and controls. Both groups were screened for antithyroid, antinuclear, antigastric parietal cell, anti-smooth muscle cell, and antimitochondrial autoantibodies. The significance of autoantibodies was determined in vitiligo patients by correlating their presence or absence with various clinical features of the patients. The overall frequencies of autoimmune and endocrine diseases were also assessed in vitiligo patients, controls, and their respective families. Vitiligo patients had an increased frequency of antithyroid antibodies and an increased frequency of autoimmune and/or endocrine diseases. These diseases included, especially, hyperthyroidism, hypothyroidism, and alopecia areata. Autoantibody-positive vitiligo patients had an increased frequency of first- and second-degree relatives having autoimmune and/or endocrine diseases. These findings tend to support an autoimmune cause of vitiligo in black patients.