皮肤老化与光老化

皮肤老化分为时程老化及光老化。时程老化又称自然老化 ,光老化则主要与紫外线 (ＵＶ)有关。一、老化的原因皮肤的老化涉及许多因素 ,如遗传、激素、环境等。其中最重要的是长期太阳辐射[1] ,这也就是为何皮肤老化在曝光的部位最明显 ,户外工作者尤为显著的原因。从组织学角度而言 ,同一个体的曝光及非曝光部位皮肤有明显的不同。老化过程也受皮肤的自然保护作用的影响 ,曝露于同样的日光 ,Ⅰ型皮肤较Ⅳ型皮肤更易老化。由于日光对皮肤的老化作用需要一个很长的时间 ,所以很难确定与老化有关的确切的作用光谱。太阳光中长波紫外线 (ＵＶＡ)…     

绞股蓝对光老化皮肤组织的影响

目的探讨外用绞股蓝对紫外线照射引起的无毛小鼠光老化模型皮肤组织中过氧化氢酶（CAT）、谷光甘肽过氧化物酶（GSH—PX）活性和羟脯氨酸（HYP）含量的变化及其对光老化皮肤组织的影响。方法将昆明种无毛小鼠随机分成5组,制模同时,给药组外用绞股蓝。测定其皮肤组织中CAT、GSH—PX活性及HYP含量。结果模型组CAT、GSH—PX活性明显降低,HYP含量明显减少（分别为P〈0．01,P〈0．05,P〈0．05）,给药组中各指标均有不同程度的改善。结论绞股蓝可以通过提高CAT、GSH—PX的活性,增加HYP含量达到抗皮肤光老化的作用。     

藏红花素对光老化皮肤成纤维细胞的影响

目的探讨藏红花素对光老化皮肤成纤维细胞的影响,期望从细胞水平阐明藏红花素抗皮肤光老化的作用与机理,为临床应用提供依据。方法 (1)分离培养人皮肤成纤维细胞,以不同浓度藏红花素(0、50、100、200μM)处理皮肤成纤维细胞,培养72 h后,应用CCK-8试剂盒检测细胞增殖情况。(2)以不同剂量紫外线(25、50、100 m J/cm^2)照射皮肤成纤维细胞,72 h后应用CCK-8试剂盒检测细胞增殖情况。(3)以不同浓度藏红花素(0、12.5、25、50、100μM)处理皮肤成纤维细胞24 h,紫外线(100 m J/cm^2)照射后即刻,应用流式细胞仪检测细胞内活性氧簇含量;照射后48 h后,应用流式细胞仪检测细胞周期;照射后72 h后,应用CCK-8试剂盒检测细胞增殖情况,并提取细胞RNA,应用RT-PCR技术检测细胞Ⅰ型胶原的表达。结果 (1)低浓度藏红花素(50、100μM)对皮肤成纤维细胞增殖无显著影响,高浓度藏红花素(200μM)可促进皮肤成纤维细胞增殖。(2)紫外线照射可显著抑制皮肤成纤维细胞增殖,并呈量效依赖关系。(3)紫外线照射提高细胞活性氧簇产生、抑制细胞增殖、抑制Ⅰ型胶原的表达,藏红花素(12.5、25、50、100μM)能减少紫外线照射引起的细胞活性氧簇产生,恢复细胞周期和Ⅰ型胶原的合成能力。结论藏红花素通过减少细胞活性氧簇,产生抵抗紫外线照射的作用,恢复皮肤成纤维细胞细胞增殖和胶原合成能力,起到抗光老化作用。     

多功能光子治疗仪治疗面部皮肤光老化107例

皮肤老化是由遗传因子决定并受多种环境因素影响的自然过程,既包含由遗传因素及不可抗因素(如重力、机体内分泌及免疫功能随机体衰老的改变)引起的自然老化,也包含由环境因素如紫外线(UV)、吸烟、风吹、接触化学物质等引起的外源性老化,日光中UV长期反复的照射是环境中影响皮肤     

南京地区人群对防晒的认知和行为及面部皮肤光老化的调查

目的调查南京地区人群的防晒认知、行为及面部皮肤光老化情况,并对其相关性进行分析。方法974例18~65岁南京地区人群,按年龄将被调查者分为10组,以问卷形式调查一般情况、防晒知识、防晒行为及面部光老化Glogau分型。将调查结果用Logistic回归模型筛选与光老化发生相关的因素。结果随着年龄的增长患皮肤光老化风险增加,46～65岁人群以Ⅲ型光老化为主。多数被调查者对防晒知识有一定的了解,并且有着积极的防晒意识,多数人能采用一些防晒方法,但对防晒霜的使用方法缺乏正确了解。有着较高防晒意识和知识者患皮肤光老化的风险小,特意进行日光浴和长时间室外活动不涂防晒霜是引起皮肤光老化的高危险因素,选择树荫、戴宽沿帽、选择秋季防晒则是保护性因素。结论积极的防晒意识和正确的防晒方法有助于防止皮肤光老化,为了更有效防止紫外线对皮肤损害,目前人们需要更好地了解防晒霜的正确使用方法。     

三亚与沈阳农村地区人群手背部皮肤纹理老化配对比较研究

目的:比较三亚与沈阳两地农民手背部皮肤纹理老化程度,探索紫外线对皮肤老化的影响。方法:采用I mage-Pr o Pl us图像分析软件,测量三亚与沈阳两地人群手背部皮肤纹理间距、纹理形成的角度和网格数。结果:除中年男性外,男女各年龄组的三亚地区人群皮肤纹理最大角度均显著高于沈阳地区人群,两地男性皮肤纹理最大角度达到老化的OR值为6.5(95%CI=1.5-28.8),女性的OR值为11.5(95%CI=2.7-48.8)。三亚地区青中年女性皮肤纹理间距显著高于沈阳地区女性,网格数显著低于沈阳地区女性。男性的皮肤网格数仅在青年时期表现出显著的两地差异。结论:三亚农村地区人群的手背部皮肤纹理老化程度高于沈阳农村地区人群,其中皮肤纹理最大角度能够更有效地反映两地人群皮肤老化的差异。     

皮肤光老化的研究进展

人的皮肤长期受到紫外线的照射容易引起光老化,而光老化与脂溢性角化、色素斑、日光性角化病及皮肤恶性肿瘤等多种疾病的发生有关,因此,预防和改善皮肤光老化已经逐渐成为皮肤科医生研究的热点。近年来,国内外学者对光老化的研究有了新的进展,通过查阅文献,笔者主要从光老化的发生机制、光老化的防治以及α1抗胰蛋白酶在光老化中的研究进展三个方面进行综述。     

线粒体在皮肤光老化的研究进展

外源性老化中, 紫外线照射导致的皮肤老化占80%以上, 称为皮肤光老化。皮肤光老化中线粒体形态和能量代谢等均有异常, 通过线粒体自噬去除异常线粒体后可延缓皮肤光老化, 线粒体参与了皮肤光老化有关过程。本文概述光老化皮肤中与线粒体生物事件相关的多种表现, 包括线粒体的形态异常、线粒体能量代谢异常、线粒体氧化应激异常、线粒体自噬、以线粒体为靶点的抗光损伤药物。     

强脉冲光治疗光老化的皮肤测试与评价

近年来,笔者科室采用强脉冲光治疗了62例光老化患者,并通过皮肤测试仪进行测定,客观评价强脉冲光对光老化皮肤的改善程度,取得了较好疗效,现报道如下。     

光老化作用对体外人皮肤成纤维细胞的影响

目的 建立体外分离培养人皮肤成纤维细胞的光老化模型,观察研究中波紫外线对人皮肤成性纤维细胞的影响.方法 使用组织块法分离培养原代人皮肤成纤维细胞,并用免疫荧光特异性标记物鉴定证实,选择不同剂量的紫外线照射人皮肤成纤维细胞后,倒置显微镜观察细胞形态学的改变;β-半乳糖苷酶(β-gal)细胞衰老试剂盒染色;MTT检测不同剂量的紫外线照射对成纤维细胞增殖能力影响;western blot检测衰老标志物P16蛋白的表达.结果 组织块法成功分离获得人皮肤成纤维细胞,用20～60mJ/cm2 UVB单次照射后,可以成功诱导人皮肤成纤维细胞出现衰老形态学的改变,其增殖能力降至正常对照组的一半左右,β-gal染色阳性率约90%,衰老相关蛋白P16表达随时相明显升高.结论 20～60mJ/cm2中波紫外线照射人皮肤成纤维细胞可诱导人皮肤成纤维细胞衰老,为今后皮肤光老化的体外研究提供了参考.     

8-甲氧补骨脂素和长波紫外线光化学疗法对皮肤光老化的影响

目的　探讨 8 甲氧补骨脂素和长波紫外线 ( psoralenandultravioletA ,PUVA)光化学疗法对皮肤光老化影响及其可能机制。方法　采用HE染色、Verhoeff染色、电镜、酶组织化学、免疫组织化学等方法检测PUVA治疗对银屑病背部非皮损区皮肤真皮基质、成纤维细胞表型、衰老相关 β半乳糖苷酶(SA β Gal)和 p16蛋白表达的影响。 结果　PUVA治疗后 ,银屑病患者背部非皮损区皮肤真皮变性胶原、弹力纤维增多 ,排列紊乱 ;真皮成纤维细胞由分裂表型转化为无分裂活性表型 ;B组和A组的SA β Gal表达阳性率分别为 13 .6%、0 .0 0 % ,p16蛋白表达阳性率分别为 81.8%、42 .9% ,两组两项指标比较均有显著性差异 ( χ2 =2 1.412 ,P <0 .0 0 1,χ2 =4.0 3 5 ,P <0 .0 5 )。结论　PUVA可诱导寻常型银屑病患者背部非皮损区真皮迅速出现具有光老化特征性的组织学及生物学特性改变 ,其机制与皮肤成纤维细胞形态及功能的特异性改变密切相关     

The effects of ultraviolet radiation on wound healing

The effects of prior ultraviolet light exposure on wound tensile strength and skin histology were evaluated in the hairless guinea pig model. Hairless guinea pigs (strain IAF/HA-HO) were irradiated with either UVA (80 J/cm2) or UVB (0.46 J/cm2) every other day for 16 weeks. Following cessation of treatment, a standard dorsal wound was made in each animal, allowed to heal, and mechanically tested to failure at 21 days. Serial 4 mm punch biopsies were obtained prior to the initial exposure and at 2, 4, 8, 12 and 16 weeks. Histological examination with haematoxylin and eosin, trichrome and elastin stains was performed. In comparison to the unexposed control group, wound tensile strength was significantly less in the UVA- and UVB-irradiated animals. Histological examination revealed a marked endothelial swelling and eosinophilic infiltration in the irradiated groups. These results indicate that repeated exposure to even moderate doses of non-ionising radiation alters normal skin structure and adversely affects subsequent wound tensile strength in this model.     

The influence of ultraviolet irradiation on the blood transfusion effect

Reports of improved survival of allografts in recipients of donor-specific blood prompted an attempt to determine the relationship of the antigenic composition of the blood product transfused to the development of immunologic unresponsiveness in rats. Cardiac allografts were transplanted from Fischer, Brown-Norway (BN), and Lewis (L) X BN (LBN) f1 hybrids to recipients treated with three weekly transfusions of 1 ml of donor-specific whole blood, erythrocytes, or ultraviolet-irradiated whole blood. Despite moderate improvement in survival with whole blood alone in the LBN- greater than L group (11.6 +/- 1.0 days), it was only with the ultraviolet-irradiated whole blood that marked prolongation was seen in all three strain combinations: Fischer- greater than L: 25.5 +/- 5.2, LBN- greater than L: 17.3 +/- 1.2, and BN- greater than L: 11.1 +/- 0.4 days compared with respective controls: 10.3 +/- 1.2, 7.3 +/- 0.5, and 7.4 +/- 0.6 days. Unlike reports for renal allografts, erythrocyte suspensions provided minimal protection for the cardiac allografts (14.2 +/- 0.8, 9.0 +/- 1.1, and 11.0 +/- 0.4 days, respectively), and adjunctive treatment with antilymphocyte serum had a similar small effect (16.3 +/- 1.4, 13.4 +/- 1.9, and 8.3 +/- 0.8 days, respectively). The elimination or inactivation of functional class 2 major histocompatibility complex antigens from the blood used for donor-specific blood transfusion may be an effective means of prolonging allograft survivals over those seen with whole blood alone; however, the degree of resultant unresponsiveness is still clearly influenced by dosage schedule, the organ transplanted, histocompatibility barrier, and adjunctive immunosuppression.     

The effect of ultraviolet radiation on the electrical conductivity of human bone

The electrical conductivity of intact bone, collagen and apatite mineral was determined in the region of moderately high fields. After exposure to ultraviolet (UV) radiation the conductivity of the specimens was redetermined. Following exposure marked decreases in electrical conductivity occurred in all specimens. The possible modes of interaction of UV radiation with bone are discussed. It is suggested that protonic conduction may be an important mode of charge transport in bone.     

The control of environmental pollution and optimal investment and employment decisions

This paper develops an optimal control model for the firm's decision-making concerning pollution control spending, employment and investment. The model explicitly considers the impact of adjustment costs of changing the level of the pollution stock and involves three state variables and two control variables. Necessary conditions are derived by the maximum principle. The results include an optimal employment-investment-pollution abatement programme, an optimal pollution control decision rule, the equilibrium optimal pollution control and spending plan, and the equilibrium employment-investment decision.     

放射辐照对异体神经移植组织学改变的影响

目的探索放射辐照对异体神经移植组织学改变的影响.方法将18只SD大白鼠随机均分为三组:自体对照组、异体对照组、辐照处理组.应用放射辐照方法处理异体神经后进行移植.术后12周移植神经和胫前肌HE染色,移植神经S-100蛋白及波形蛋白免疫组化和甲苯胺蓝染色,观察其组织学变化和计数单位面积内阳性轴突数和再生的有髓神经纤维数量.结果放射辐照处理后的移植神经,纤维组织增生和炎性细胞浸润较少,胫前肌生长良好,再生有髓神经纤维增多(与异体对照组比较,P＜0.05),单位面积内的阳性轴突数明显增多(P＜0.05).结论放射辐照处理可降低异体神经的抗原性.     

放射辐照对异体神经移植组织学改变的影响

目的　探索放射辐照对异体神经移植组织学改变的影响。方法　将 18只SD大白鼠随机均分为三组 :自体对照组、异体对照组、辐照处理组。应用放射辐照方法处理异体神经后进行移植。术后 12周移植神经和胫前肌HE染色 ,移植神经S - 10 0蛋白及波形蛋白免疫组化和甲苯胺蓝染色 ,观察其组织学变化和计数单位面积内阳性轴突数和再生的有髓神经纤维数量。结果　放射辐照处理后的移植神经 ,纤维组织增生和炎性细胞浸润较少 ,胫前肌生长良好 ,再生有髓神经纤维增多 (与异体对照组比较 ,P <0 .0 5 ) ,单位面积内的阳性轴突数明显增多 (P <0 .0 5 )。结论　放射辐照处理可降低异体神经的抗原性     

The influence of dietary and environmental factors on prostate cancer risk

Prostate cancer is the most common malignancy found in males and one of the most common causes of cancer death. The epidemiology implicates environmental and nutritional factors in the initiation and progression of the disease. Identification of these factors would allow chemoprevention strategies to be tested. Potent mutagenic and carcinogenic heterocyclic amines and polycyclic aromatic hydrocarbons are produced in cooked meat, and following metabolic activation some of them are strongly associated with prostate carcinogenesis in rodents. Primary cell cultures of human prostate epithelial cells were obtained from patients undergoing transurethral resection of the prostate. Metabolic activation of the cooked food carcinogens 2-amino-1-methyl-6-phenylimidazo- [4,5-b]pyridine (PhIP) and benzo[a]pyrene (B[a]P) was examined and resultant DNA damage (single strand breaks) measured using the Comet assay. Increased concentrations of carcinogen were associated with increased DNA damage and comet tail length compared to controls. Prostate Cancer and Prostatic Diseases (2000) 3, 256-258     

Occlusive clothing and ultraviolet radiation in hip surgery

In a randomized study of 20 total hip arthroplasties, the staff wore shirts and trousers of a fabric impervious to bacteria underneath operating gowns of a non-woven material. Volumetric air sampling demonstrated a low number of colony-forming units with this clothing, further reduced by ultraviolet radiation to below 10 colony-forming units/m³, the upper limit of “ultraclean air,” in all the cases (median 2.6, range 1.1-7.1).