目的:研究小剂量长波紫外线(UVA)辐射对人体皮肤的累积效应。方法:以10名志愿者的臀部作为受试部位,共分为3个区域:阴性对照区域,不进行照射;小剂量照射区域和阳性对照区域分别进行UVA照射,每周照射3次,连续13周,共39次。其中小剂量照...目的:研究小剂量长波紫外线(UVA)辐射对人体皮肤的累积效应。方法:以10名志愿者的臀部作为受试部位,共分为3个区域:阴性对照区域,不进行照射;小剂量照射区域和阳性对照区域分别进行UVA照射,每周照射3次,连续13周,共39次。其中小剂量照射区域的累积剂量为50 J/cm^2;阳性对照区域的累积剂量为1 000J/cm^2。照射前后测定皮肤角质层含水量、经皮水分丢失(transepidermal water loss,TEWL)、pH值、皮肤颜色的L~*a~*b~*值和M、E值。取照射区皮肤组织进行苏木精-伊红染色、弹性纤维染色和免疫组化染色,观察表皮、角质层厚度、胶原纤维、弹性纤维的变化、基质金属蛋白酶(MMP)-1和人类长寿基因SIRT1的蛋白表达产物在UVA照射后的变化。结果:小剂量照射区域角质层含水量有下降趋势,TEWL有增加趋势,L~*值下降、M、a~*、E值升高,pH值无明显变化。皮肤的角质层和表皮厚度增加,真皮中的胶原纤维细碎、淡染,弹性纤维片断化。MMP-1和SIRT1的表达增加。结论:小剂量UVA照射可以引起皮肤光老化。展开更多
Background: Keratectasia is one of the most severe complications after refract ive laser surgery. Usually penetrating keratoplasty is the treatment of choice t o achieve an optical rehabilitation in such cases. Patien...Background: Keratectasia is one of the most severe complications after refract ive laser surgery. Usually penetrating keratoplasty is the treatment of choice t o achieve an optical rehabilitation in such cases. Patients and Methods: We repo rt on a female patient who developed keratectasia in both eyes 4 weeks after LAS IK. Due to a severe keratectasia 10 months after LASIK, a treatment with ribofla vin/UVA cross-linking was performed. Results: Due to the induced collagen cross linking the biomechanical status of the cornea was stabilized and a progression of the keratectasia was prevented. The postoperative refraction and corneal topo graphy have been stable for 18 months. Conclusion: Collagen cross-linking leads to a stiffening of the anterior parts of the corneal stroma. The increase of bi omechanical stability can stop the progression of a keratectasia after LASIK by means of a simple procedure.展开更多
文摘目的:研究小剂量长波紫外线(UVA)辐射对人体皮肤的累积效应。方法:以10名志愿者的臀部作为受试部位,共分为3个区域:阴性对照区域,不进行照射;小剂量照射区域和阳性对照区域分别进行UVA照射,每周照射3次,连续13周,共39次。其中小剂量照射区域的累积剂量为50 J/cm^2;阳性对照区域的累积剂量为1 000J/cm^2。照射前后测定皮肤角质层含水量、经皮水分丢失(transepidermal water loss,TEWL)、pH值、皮肤颜色的L~*a~*b~*值和M、E值。取照射区皮肤组织进行苏木精-伊红染色、弹性纤维染色和免疫组化染色,观察表皮、角质层厚度、胶原纤维、弹性纤维的变化、基质金属蛋白酶(MMP)-1和人类长寿基因SIRT1的蛋白表达产物在UVA照射后的变化。结果:小剂量照射区域角质层含水量有下降趋势,TEWL有增加趋势,L~*值下降、M、a~*、E值升高,pH值无明显变化。皮肤的角质层和表皮厚度增加,真皮中的胶原纤维细碎、淡染,弹性纤维片断化。MMP-1和SIRT1的表达增加。结论:小剂量UVA照射可以引起皮肤光老化。
文摘Background: Keratectasia is one of the most severe complications after refract ive laser surgery. Usually penetrating keratoplasty is the treatment of choice t o achieve an optical rehabilitation in such cases. Patients and Methods: We repo rt on a female patient who developed keratectasia in both eyes 4 weeks after LAS IK. Due to a severe keratectasia 10 months after LASIK, a treatment with ribofla vin/UVA cross-linking was performed. Results: Due to the induced collagen cross linking the biomechanical status of the cornea was stabilized and a progression of the keratectasia was prevented. The postoperative refraction and corneal topo graphy have been stable for 18 months. Conclusion: Collagen cross-linking leads to a stiffening of the anterior parts of the corneal stroma. The increase of bi omechanical stability can stop the progression of a keratectasia after LASIK by means of a simple procedure.
