新型兰花皮肤美白提取物

对于亚洲人，面部色斑的出现常常是皮肤老化的早期信号之一。长期暴露于紫外线、局部炎症刺激或体内激素的突然变化，导致皮肤出现色素沉着，表现为色斑，并伴有皮肤光泽消失。     

环境因素引起皮肤衰老

人体皮肤直接与外环境接触,受环境因素影响最为显著,尤其是身体暴露部位,如面部、颈部、上臂等。据目前所知,对皮肤有不良作用的环境因素主要有日光中紫外线、红外线,香烟的烟雾,空气污染等,它们均可加速皮肤的衰老过程。 日光中紫外线与皮肤老化有着密切的关系。紫外线根据其波长有不同的     

防晒化妆品

防晒化妆品克丽丝汀·迪奥（中国）香水化妆品有限公司２０００３１日光中紫外线能使皮肤上皮细胞产生一系列生物化学反应，形成黑色素，使皮肤黑色素沉积。长期暴露在阳光下，紫外线不仅能使皮肤变黑，而且会使皮肤老化，弹性减少，产生皱纹，并能引起日光性皮炎，实验证...     

沈阳农村居民手背部皮肤纹理与日光暴露关系

目的 了解中国北方地区农村居民皮肤纹理与日光暴露的关系.方法 采用整群抽样方法抽取长期居住在辽宁省沈阳市王滨乡的当地居民361人作为调查对象,对收集到的手背部皮肤图像评定老化级别,使用Image-Pro Plus 5.0图像分析软件测量皮肤纹理间距、纹理形成的角度和网格数.结果 沈阳农村居民日光高暴露和低暴露组皮肤老化级别平均值分别为(4.48±1.14)和(3.65±1.43)分,达到老化的人数分别为154和97人,老化比例分别为83.7％和54.8％;各年龄组日光高暴露组皮肤老化水平和老化比例均高于低暴露组,但差异均无统计学意义(P＞0.05);年龄10～19和30 ～49岁及老化级别为4～6级时,日光高暴露组农村居民手部皮肤纹理的最大角度均大干低暴露组(P＜0.05).结论 沈阳市农村居民皮肤纹理形成的角度与日光暴露密切相关.     

夏日须当心紫外线过敏

很多人都喜欢阳光明媚的天气，但如果外出时忽略了防晒，一些特殊体质的人就易患上光敏性皮炎。经常暴露在阳光下的脸、颈、手臂等部位会出现丘疹、红斑、水疱、脱屑等，还会伴有瘙痒。人群中约有30%的人会对紫外线产生过敏，其中室内工作的人对紫外线的敏感性比室外工作的人高；青年敏感性比幼儿及老年人高。因此，青壮年与室内工作者应慎防发生紫外线过敏。     

成为光彩照人的无龄肌美人

紫外线会导致色斑、皱纹、松弛等皮肤老化现象。还会令皮肤“糖化”。让我们开启保持美肌的“饮食护肤之旅”吧！ 获得美肌双重对策 “导致皮肤老化的主要就是紫外线和糖化这两个原闪。”再生未来诊所神户的市桥正光院长说。最新的研究发现,紫外线会破坏皮肤胶原蛋白和弹性蛋白。“紫外线和因紫外线而产生的活性氧会破环与皮肤再生相关的NDA。同时,皮肤的新陈代谢受到阻碍,导致山现皮肤问题和疾病。”市桥院长说。     

防晒是功课 修好学问多

正每个人对紫外线的敏感程度不同,即使在同一时间,在不同的地点,阳光对皮肤的"杀伤力"也不同。因此,要根据自身皮肤情况、所处的环境选择防晒用品。此外,皮肤在晒后6个小时内,给予正确保养,可大大减少晒伤机会。因此,掌握科学的防晒方法,保护肌肤很重要。防晒没做好,皮肤老化快防晒主要阻隔或吸收的紫外线类型有UVA(长波紫外线)、     

紫外线照射致皮肤P53抑癌基因诱变的研究

选择不同紫外线暴露量人群４５例，采用单链构象多态性分析对暴露部位皮肤ＤＮＡ进行Ｐ５３基因第七外显子突变检测，并采用１０例Ｂｏｗｅｎ病病变皮肤为对照。结果Ｂｏｗｅｎ病例检出Ｐ５３抑癌基因诱变阳性２例（２／１０），但不同紫外线暴露量的人群无一例诱变阳性。结果提示Ｐ５３基因突变可能在癌前期发生，但其出现不早于癌前期。     

护理肌肤该出手时就出手

皱纹产生于皮肤的老化。皮肤老化分为自然老化和外源性老化。自然老化是由遗传因素及不可抗力因素（如重力、机体内分泌、免疫功能随机体衰老而发生的改变）引起的皮肤的退行性改变．是随着时间推移而自然发生于皮肤中的结构和功能变化。外源性老化则是指由环境因素如紫外线、吸烟、风吹、接触化学物质等引起的老化。其中紫外线导致的光老化是外源性老化中最主要的因素。皱纹的产生就是在自然老化过程中重叠有外源性老化所共同导致的结果。     

给皮肤穿上“遮阳外衣”──谈如何选择与使用防晒化妆品

给皮肤穿上“遮阳外衣”──谈如何选择与使用防晒化妆品辽宁省预防医学研究所主任医师戴玉林众所周知，太阳光过度曝晒皮肤，能引起日光性皮炎、黑色素沉着、皮肤老化、弹性减小，产生皱纹。这是由于日光中的紫外线对皮肤表皮层和真皮层造成损害而引起。那么，如何防止日...     

Occupational exposure to ultraviolet radiation: a health risk assessment

This review applies health risk assessment methodology to the subject of occupational exposure to ultraviolet radiation (UVR). Ultraviolet radiation is produced by many sources, and for most people the sun is their main source of exposure. In the occupational environment, there are also many artificial sources, of which welding arcs are the predominant and most intense. Adverse health effects include photokeratitis, erythema, pterygium, some types of cataract, non-melanocytic skin cancer, and malignant melanoma. Outdoor workers and workers who are exposed to certain artificial sources (particularly welding arcs), frequently are exposed to UVR levels that are above the current exposure limits. Such workers may also be at an additional risk of developing nonmelanocytic skin cancer along with other chronic conditions, including malignant melanoma. A range of control measures is available but nevertheless, many workers (particularly those exposed to solar UVR) do not make full use of these measures. Therefore, the implementation of health education campaigns and other initiatives that encourage use are needed. Overall, although exposure to UVR presents a substantial risk for certain occupations, the current exposure standards and currently available control measures (if used) are considered to provide adequate protection for most workers.     

Mechanism of selenium-induced inhibition of arsenic-enhanced UVR carcinogenesis in mice

BACKGROUND: Hairless mice that ingested arsenite in drinking water exhibited more than a 5-fold enhancement of ultraviolet radiation (UVR) carcinogenesis, whereas arsenite alone was carcinogenically inactive. Dietary organoselenium blocked the cancer enhancement effect of arsenic but not cancer induction by UVR. OBJECTIVE: In this study we sought to explain selenium blockage of As enhancement by establishing the extent that As and Se tissue distributions are coincident or divergent. METHODS: We used the X-ray fluorescence microprobe at the Advanced Photon Source (Argonne National Laboratory) to probe sections of skin and liver from hairless mice exposed to a) UVR, b) UVR + As, c) UVR + organoselenium, or d) UVR + As + organoselenium. RESULTS: We found elevated levels of As in the skin epithelium (hair follicles and epidermis) and diffusely in the liver of mice exposed to UVR + As. Arsenic was entirely absent in skin in mice exposed to UVR + As + organoselenium, but a diffuse low level was seen in the liver. As and Se locations were consistently divergent in skin; As was more diffusely distributed, whereas Se was strongly associated with membranes. X-ray absorption near-edge spectra are consistent with the presence of the seleno-bis(S-glutathionyl) arsinium ion in the liver. CONCLUSIONS: Supplemental Se was uncommonly effective at preventing even a trace of As in skin at 14 or 196 days of continuous exposure to As in drinking water. Traces of the seleno-bis(S-glutathionyl) arsinium ion in the liver suggested that formation of this compound was more likely to be responsible for the As-blocking effect of Se than was a mechanism based on antioxidation.     

Effect of solar UV radiation on earthworm (Metaphire posthuma)

Human health risks like damage to the eyes, immune system, and skin are known to be associated with increasing ultraviolet radiation (UVR) in the environment. In this study, we evaluated the phototoxic effects of UVR in sunlight and its possible mechanism of action by using earthworm as an alternative model because earthworm skin contains several biomolecules (tetraene and triene sterol) similar to human beings. We studied the generation of reactive oxygen species (ROS), photooxidation of lipids, and histopathological changes in earthworm integument. It was observed that UVR-exposed earthworm skin homogenate produced a significant amount of singlet oxygen ((1)O(2)), superoxide anion (O(2)(*)(-)), hydroxyl radicals ((*)OH), and photooxidation of lipids. The production of ROS and lipid peroxidation product was found dependent on the dose of solar UVR in earthworm integument. Histological anomalies such as thickening, vacuolation, and hypertrophy of epidermal cells were observed when the animals were exposed for 1 to 2h, while a higher exposure period (3h) caused degeneration of circular and longitudinal muscles. Continuous sunlight exposure for more than 3h was found lethal to worms. These observations suggested that the current level of UVR in sunlight may produce significant phototoxic effects in the earthworms probably via the generation of ROS (photodynamic action). Possible increases in UVR in view of ozone depletion may be more detrimental to the biomolecules in the worm's skin. The earthworm thus turned out as a simple, sensitive, and cost-effective test organism for the assessment of the hazardous potential of solar radiation and also for planning safety measures for human beings.     

Protection from sunlight, particularly for children

Excessive exposure to ultraviolet radiation (UVR) in childhood has been recognized as an extrinsic risk factor for the development of skin cancer later in life. The risk of squamous cell carcinoma is clearly related to the lifetime accumulated UVR dose, while the risk of melanoma and basal cell carcinoma is increased by intermittent UVR exposure, which is frequently responsible for sunburn. Besides UVR exposure, several intrinsic factors increase the risk of skin cancer, especially the risk of melanoma, such as skin type, the number of normal and dysplastic melanocytic naevi and family history. Responsible sun behaviour in childhood is most important to prevent skin cancer: stay in the shade, especially between 12:00 and 3:00 p.m., wear protective clothing, including a hat and sunglasses, try to build-up natural adaptation of the skin to UVR and apply a sunscreen to UVR exposed skin. There are strong indications that the possible preventive effect of sunscreens on the development of skin cancer is abolished in case of prolonged and intensive UVR exposure, because of a false feeling of safety. The most important measure to prevent the development of melanomas and basal cell carcinomas is probably the prevention of sunburn in childhood.     

Sun-protective behaviors of California farm workers

OBJECTIVE: Farm workers are exposed to long hours of solar ultraviolet radiation (UVR), placing them at higher risk for skin cancer. The goal of this study was to evaluate farm workers' sun exposure behaviors. METHODS: Farm workers (n=326) in the San Joaquin Valley of California were interviewed about their sun protective behaviors; these behaviors also were observed directly and these data were used to assess whether participants adequately protected against UVR exposure. RESULTS: All participants were Latino men with a mean age of 33 years. Although rates of wearing any hat and long-sleeved shirts were high, rates of wearing wide-brimmed hats and sunscreen were low. CONCLUSIONS: This study is important because there is limited research focused on farm workers' protective behaviors against UVR exposure. Interventions to improve sun protection behaviors of farm workers are needed.     

Arsenic-induced enhancement of ultraviolet radiation carcinogenesis in mouse skin: a dose-response study

The present study was designed to establish the form of the dose-response relationship for dietary sodium arsenite as a co-carcinogen with ultraviolet radiation (UVR) in a mouse skin model. Hairless mice (strain Skh1) were fed sodium arsenite continuously in drinking water starting at 21 days of age at concentrations of 0.0, 1.25, 2.5, 5.0, and 10 mg/L. At 42 days of age, solar spectrum UVR exposures were applied three times weekly to the dorsal skin at 1.0 kJ/m2 per exposure until the experiment ended at 182 days. Untreated mice and mice fed only arsenite developed no tumors. In the remaining groups a total of 322 locally invasive squamous carcinomas occurred. The carcinoma yield in mice exposed only to UVR was 2.4 +/- 0.5 cancers/mouse at 182 days. Dietary arsenite markedly enhanced the UVR-induced cancer yield in a pattern consistent with linearity up to a peak of 11.1 +/- 1.0 cancers/mouse at 5.0 mg/L arsenite, representing a peak enhancement ratio of 4.63 +/- 1.05. A decline occurred to 6.8 +/- 0.8 cancers/mouse at 10.0 mg/L arsenite. New cancer rates exhibited a consistent-with-linear dependence on time beginning after initial cancer-free intervals ranging between 88 and 95 days. Epidermal hyperplasia was elevated by arsenite alone and UVR alone and was greater than additive for the combined exposures as were growth rates of the cancers. These results demonstrate the usefulness of a new animal model for studying the carcinogenic action of dietary arsenite on skin exposed to UVR and should contribute to understanding how to make use of animal data for assessment of human cancer risks in tissues exposed to mixtures of carcinogens and cancer-enhancing agents.     

Sunscreens, skin photobiology, and skin cancer: the need for UVA protection and evaluation of efficacy

Sunscreens are ultraviolet radiation (UVR)-absorbing chemicals that attenuate the amount and nature of UVR reaching viable cells in the skin. They are selected and tested for their ability to prevent erythema. No sunscreen prevents photodamage, as it has been demonstrated that suberythemal doses of UVR cause a variety of molecular changes (including DNA damage) in these cells. Furthermore, the spectrum of UVR reaching viable cells is altered by topically applied sunscreen. In this review, the basic aspects of sunscreens and skin photobiology are reviewed briefly. Although there can be no question concerning the efficacy of sunscreens for the prevention of erythema, questions remain because of the possible cumulative effects of chronic suberythemal doses and the increased exposure of skin cells to longer UVR wavelengths. The current major issue surrounding sunscreens involves their ability to protect skin cells against the effects of UVA radiation. These UVA effects may be direct damage (base oxidations) or effects on the skin immune system, yet there is no uniformly accepted method for the evaluation of UVA protection. This review is focused primarily on the latter topic covering action spectra that implicate the need for UVA protection. In addition, in vivo and in vitro methods proposed for the evaluation of candidate sunscreen formulations of UVA protective ability are reviewed. Finally, revisions in the terminology used to describe the protection afforded by sunscreens are suggested. It is proposed that SPF ("sun" protection factor) be renamed "sunburn" protection factor and that "critical wavelength" be designated "long wave index."     

Time- and Tissue-Dependent Polychlorinated Biphenyl Residues in Hairless Mice After Exposure to Polychlorinated Biphenyl-Contaminated Soil

Four groups of 16 age-matched female Crl:SKH1-hrBR hairless mice were exposed to either control soil or polychlorinated biphenyl (PCB)–contaminated soil (retrieved from an electrical waste landfill in Southern Illinois) for 11 weeks. The mice were exposed in a study to determine interactions between environmental PCBs and ultraviolet radiation (UVR), but the UVR group did not differ and provided a replicate for the residue study. Ear biopsies were performed immediately after the termination of soil exposure. The mice were maintained in regular bedding for 37 weeks thereafter. The ear-skin, trunk-skin, fat-pad, and liver samples were collected and weighed at the end of the study (week 48) and analyzed for PCB residues. A total of 141 PCB congeners were target analytes. There were significant differences in body weights and food consumption from week 2 to 28. The liver weights of mice treated with PCB only were significantly greater than those of UVR-treated mice. The fat-pad weight did not differ among treated groups. PCB residues in the ear biopsies specimens of mice exposed to contaminated soil were 342.3 and 317.2 ppm in the PCB- and PCB + UVR–treated groups, respectively, and contained both persistent and episodic congeners. After 37 weeks of isolation from soil, the ear PCB residues decreased to 21.5 ppm (PCB group) and 14.5 ppm (PCB + UVR group), and only persistent congeners contributed to the total PCB residues. The accumulation of PCB residues was highest in the fat pad (fat pad > ear skin > trunk skin > liver) in both PCB ± UVR groups at the end of the study. However, the percentage of individual congeners contributing to total PCBs in these different tissues did not differ.     

Artificial suntanning: spectral irradiance and hazard evaluation of ultraviolet sources

High incidences of skin damage and skin cancer amongst Australians have resulted in numerous campaigns to encourage people to protect themselves against solar ultraviolet radiation (UVR). The detrimental effects of UV-B radiation have been known for some time but recently there has been concern over the effects of UV-A radiation which had been thought of as relatively harmless. The proliferation of solaria, which incorporate UV-A sources, prompted the issuing of an Australian standard dealing with technical and non-technical aspects of the artificial suntanning industry. The purpose of this study was to measure the irradiance and spectral distribution of the emission from sunbeds and other UVR sources used for tanning, to evaluate the hazard potential and also the compliance with the standard. It was found that the majority of the UV-A lamps evaluated met the requirements of the standard. The UV-B lamps and portable sunlamps are potentially hazardous and their use should be discouraged. In general, the survey of solaria highlighted the need for further education of the public and especially the users and operators of solaria, on the hazards of UVR and of protective measures required for its safe use.