皮肤光老化模型构建的评价

准确的构建模型对于皮肤光老化研究非常重要。构建体系应包括选择相应的研究对象、合理地施加光损伤和准确的评价方法。目前的模型主要包括体外培养皮肤组成细胞或皮肤组织、体外人皮肤模型、模型动物和志愿者等几种。各种模型在实际应用中都存在其优势和局限性。不同的研究应依据相应的研究目的选择和构建光老化模型。为了增加研究的科学性和严谨性,目前多数研究选择数种模型的联合应用。从事光老化的研究者有必要联合制定一套相对严谨和统一的模型体系。     

光老化的皮肤改变及其机制

光老化的皮肤粗糙、松弛、下垂，出现皱纹、色斑、毛细血管扩张、良性甚至恶性肿瘤等。主要组织学特征为胶原纤维减少和异常弹性纤维沉积。而导致这些改变的主要机制有基质金属蛋白酶表达升高和DNA损伤修复能力下降。     

皮肤光老化机制研究进展

长期紫外线辐射将导致皮肤胶原纤维减少和异常弹性纤维沉积而出现皮肤光老化。近年来大量研究表明紫外线作用于人体皮肤后通过产生的活性氧、细胞表面的生长因子受体、细胞因子受体及许多酶的级联 ,激活转录因子激活蛋白 ,使基质金属蛋白酶高表达而降解细胞外基质 ,最终导致皮肤光老化     

皮肤光老化和抗氧化剂研究进展

皮肤光老化是指皮肤长期受紫外线(ultraviolet,UV)辐射引起的皮肤老化。紫外线可通过诱导活性氧和脂质过氧化物丙二醛生成,诱导金属蛋白酶类表达等途径诱发皮肤光老化。针对光老化的发病机制采用各种天然或合成抗氧化剂能够有效的预防和缓解皮肤光损伤,本文对皮肤光老化机制及治疗研究进展进行综述。     

皮肤光老化治疗研究进展

预防和治疗皮肤光老化是当前研究的热点,各种抗光老化药物、化学剥脱剂、物理治疗、注射填充等方法可改善皮肤光老化症状。本文对皮肤光老化各种治疗方法的最新研究进展进行综述,以期为皮肤光老化治疗的相关研究提供一些参考。     

皮肤光老化机制研究进展

长期紫外线辐射将导致皮肤胶原纤维减少和异常弹性纤维沉积而出现皮肤光老化。近年来大量研究表明紫外线作用于人体皮肤后通过产生的活性氧、细胞表面的生长因子受体、细胞因子受体及许多酶的级联，激活转录因子激活蛋白，使基质金属蛋白酶高表达而降解细胞外基质，最终导致皮肤光老化。     

光老化皮肤的预防,减慢和康复

光老化皮肤表现为发黄、革样、松垂和起皱,其下结缔组织出现损伤以及发生各种良性、癌前期或恶性肿瘤。组织学改变在青年人皮肤弹性组织的纤维是纤细、分枝的、并有垂直纤维分枝上达表皮真皮交界处。老年非暴露的皮肤,弹力     

皮肤光老化

皮肤光老化是皮肤衰老的一部分。与自然老化相比皮肤光老化具有特征性的临床表现，并伴有相应的组织学及分子生物学水平的改变。皮肤光老化有特定的发生原因和影响因素。采取适当的预防或治疗措施可以减缓皮肤光老化发生。     

皮肤光老化的诊断

皮肤光老化在临床上、组织学上和皮肤的固的性老化有显著差异。但目前区分老化皮肤中哪些变化是由光老化引起、哪些是固有性老化的结果有很多困难。就目前皮肤光老化诊断方面的研究进展作一综述,将皮肤光老化作为一种发生在皮肤固有性老化基础上的疾病或皮肤综合征的范畴进行分型分类,并介绍有关临床诊断标准的研究。     

绿茶提取物对光老化、光免疫抑制的防护作用

目的 探讨不同浓度的绿茶霜对光老化、光免疫抑制的防护作用。方法 招募20名健康志愿者,在背部7个非曝光部位分别涂抹以不同浓度（2% ～ 5%）的绿茶霜（保湿霜基质中添加不同浓度的绿茶提取物配制而成）或基质,并予1.5倍最小红斑量的模拟日光照射。免疫组化染色观察细胞角蛋白5/6、16含量及CD1a、HLA-DR阳性细胞密度。结果 2%及3%的绿茶霜可有效地防护ssUV照射引起的明显的红斑及色素沉着。ssUV照射后CK5/6阳性 + 强阳性比例在只照光部位达50%,在3%绿茶霜的部位仅达25%。CK16阳性 + 强阳性比例在只照光部位达69%,在2%绿茶霜的部位仅达31%。与正常人对照相比,只照光部位表皮CD1a+或HLA-DR+的朗格汉斯细胞密度下降75%以上。一定浓度的绿茶霜可较好地抑制这种密度下降,其中3%绿茶霜的防护效果最佳。结论 绿茶提取物可以有效地防护皮肤光老化、光免疫抑制。最适合的添加浓度为2%或3%。     

Angiogenesis in skin aging and photoaging

Angiogenesis, the process of generating new blood vessels, is affected by various physiological and pathological conditions of skin. The skin aging process can be divided into intrinsic aging and photoaging. With aging, cutaneous blood vessels undergo pronounced alterations. A reduction of the cutaneous microvasculature has been observed in the skin of elderly individuals. Human skin is exposed daily to solar ultraviolet (UV) radiation, infrared rays and heat, and these stimuli are known to induce skin angiogenesis. Interestingly, although acute UV irradiation stimulates skin angiogenesis, cutaneous blood vessels are decreased in chronically photodamaged skin. The reason for the differential effects of acute and chronic UV exposure on skin angiogenesis remains to be elucidated. This review discusses the vascularization changes in intrinsically aged and photoaged human skin, the effects of UV irradiation, infrared rays and heat on skin angiogenesis, and the effects of topical retinoic acid treatment on UV-induced angiogenesis and cutaneous vascularity in aged and photoaged human skin. An understanding of the molecular mechanisms of aging- and photoaging-dependent changes of skin angiogenesis may provide us with new insights to prevent and treat the skin aging process.     

培养的人皮肤成纤维细胞光老化模型中自噬水平的研究

目的 研究人皮肤成纤维细胞的光老化模型中细胞自噬功能的变化。方法 通过UVB多次照射培养的人皮肤成纤维细胞,制作光老化人皮肤成纤维细胞模型,同时设立不用UVB照射的对照组。用β-半乳糖苷酶法测定未照射的对照组及光老化组细胞的老化程度,并分别测定两组细胞的自噬体表达水平。结果 经UVB重复照射后的光老化人皮肤成纤维细胞大多变形、扭曲,部分细胞死亡。光老化组与对照组β-半乳糖苷酶表达阳性细胞的百分率分别为50.60% ± 5.04%、14.58% ± 2.69%,两组间差异有统计学意义（P ＜ 0.01）。光老化组与正常对照组自噬体阳性细胞百分率分别为14.91% ± 4.59%、68.45% ± 8.25%,两组间差异有统计学意义（P ＜ 0.01）。结论 人皮肤成纤维细胞光老化模型形态明显异常,生长基本停滞,老化程度明显高于正常细胞,而自噬水平则明显低于正常对照组细胞。     

Skin surface topography grading is a valid measure of skin photoaging

BACKGROUND: The technique of grading the surface topography of sun-exposed skin using silicone impressions of the skin surface is a simple, non-invasive method for measuring skin damage because of sun exposure, but it has never been validated in a community setting. OBJECTIVE: To investigate the repeatability and validity of using standardly-graded skin impressions as a means of assessing skin photoaging. PATIENTS/METHODS: A random sample of 195 adults aged 18-79 years and living in Nambour, Australia (latitude, 26 degrees South) had a silicone impression taken of the back of the left hand and a 2 mm punch biopsy of the skin at the same site. Silicone impressions were graded twice independently and histological photoaging was determined by two pathologists. RESULTS: Grading of silicone impressions of skin surface topography was highly repeatable (weighted kappa > 0.8). Compared with those with low skin impression grades (least degeneration), people with high grades were three times more likely to show a high degree of dermal elastosis on skin histology (odds ratio 3.1, 95% confidence interval 1.6, 5.7) after adjusting for age, sex, skin colour, tanning ability, occupational exposure, smoking and height-adjusted weight. Other photoaging changes in the stratum corneum and dermis were also strongly correlated with high grades of damage on skin impressions. CONCLUSION: Grading silicone impressions of skin surface topography is a highly reliable and a valid measure of photoaging and enables prediction of dermal elastosis in a population setting.     

Consultation for photoaging skin

Chemical peeling remains a valuable tool for the cosmetic surgeon to treat photoaging skin. Choices available include superficial, medium, and deep chemical peeling agents along with preparatory cosmoceutical agents to prep the skin and maintain rejuvenation. This article will prepare the cosmetic surgeon to include the latest agents in his practice and correctly choose which treatment is best for patients with individual problems of photoaging of the face and body, acne scars, and pigmentary problems. These modalities will be compared with other treatment modalities, such as laser and dermabrasion.     

夏枯草对UVA诱导的豚鼠皮肤光老化的防护作用

皮肤光老化是指紫外光长期辐射引起的慢性损容性皮肤损伤,表现为面部等曝光部位皮肤粗糙、深皱纹、色斑增多等.为了寻找安全有效的天然防光物质,我们应用夏枯草进行皮肤光老化的防护研究.