Carrera Cristina, Puig Susana, Llambrich Alex, Palou Josep, Lecha Mario, Massi Daniela, Malvehy Josep
Melanoma Unit, Dermatology Department, Hospital Clínic de Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.
Dermatology. 2008;217(2):124-36. doi: 10.1159/000134612. Epub 2008 May 26.
Ultraviolet radiation (UVR) plays an important role in the development of melanocytic lesions. Sunscreens have shown an impact in the prevention of UVR damage; however, their role in melanocytes has not been well established. The aim was to design and validate an in vivo human model to study the influence of UVR and sunscreen protection on nevi.
A model describing clinical, dermoscopic, histopathological and molecular changes after UVR with or without protection was elaborated. Two UVB minimal erythema doses were irradiated on 4 nonsuspicious nevi from 4 patients; previously one half of each lesion was protected, in 2 cases with a physical opaque material and in the other 2 lesions by applying a high physical and chemical protection sunscreen (containing octocrylene, Parsol 1789, titanium dioxide, Mexoryl SX, Mexoryl XL). Lesions were excised 7 days afterwards.
After 7 days, clinical and dermoscopic changes (more pigmentation, erythema, dotted vessels, blurred network) were noted comparing the lesions before and after irradiation, especially when comparing both sides of each nevus (protected and nonprotected). Histopathological and immunohistochemical studies demonstrated marked melanocytic activation on nonprotected areas and a high proliferation index of keratinocytes. Both physical and sunscreen protections seem to avoid these changes.
A useful and secure human model to study the UVR influence, and efficacy of sunscreens, on melanocytic lesions was developed. In vivo and ex vivo differences between irradiated nevus versus irradiated nevus plus sunscreen or physical protection were found.
紫外线辐射（UVR）在黑素细胞性病变的发生发展中起重要作用。防晒霜已显示出对预防UVR损伤有影响；然而，它们在黑素细胞中的作用尚未完全明确。目的是设计并验证一种体内人体模型，以研究UVR和防晒保护对痣的影响。
构建一个描述有或无保护情况下UVR照射后临床、皮肤镜、组织病理学和分子变化的模型。对4例患者的4个非可疑痣照射两个UVB最小红斑剂量；之前，每个痣的一半进行保护，其中2个病变用物理不透明材料保护，另外2个病变涂抹高物理和化学防护的防晒霜（含二乙氨羟苯甲酰、二甲基辛酯、二氧化钛、双-乙基己氧苯酚甲氧苯基三嗪、亚甲基双-苯并三唑基四甲基丁基酚）。7天后切除病变。
7天后，比较照射前后的病变，尤其是比较每个痣的两侧（保护侧和未保护侧），发现临床和皮肤镜变化（色素沉着增加、红斑、点状血管、网状结构模糊）。组织病理学和免疫组化研究显示未保护区域有明显的黑素细胞活化以及角质形成细胞的高增殖指数。物理防护和防晒似乎都能避免这些变化。
开发了一种有用且安全的人体模型，用于研究UVR对黑素细胞性病变的影响以及防晒霜的功效。发现照射痣与照射痣加防晒霜或物理防护之间存在体内和体外差异。
