NB-UVB治疗慢性湿疹疗效观察

目的探讨NB-UVB治疗慢性湿疹的临床疗效。方法治疗组以窄波UVB照射配合常规疗法;对照组只用常规疗法。结果治疗组有效率为89.47%,对照组为76.32%,两组比较差异有统计学意义(P<0.05)。结论窄波UVB治疗湿疹安全有效。     

Relationship between covalently bound ceramides and transepidermal water loss (TEWL)

The stratum corneum, which is the outermost layer of the skin, functions as an important barrier to maintain biological homeostasis. The multilamellar structures formed by intercellular lipids present in the stratum corneum are considered to play an important role in barrier function. Most intercellular lipids are unbound and can be extracted by organic solvents, but some intercellular lipids are covalently bound to cornified envelope proteins. Decreases in unbound lipid levels reduce the barrier function of the stratum corneum, but the relationship between bound lipid and the barrier function of the stratum corneum is not well understood. In this study, we examined the relationship between the amount of covalently bound ceramide, the main bound lipid, and the barrier function of the stratum corneum. A single dose of UVB irradiation (2 x MED), or continuous UVB irradiation (0.5 x MED/day for 14 days) to the back, or feeding with an essential fatty acid-deficient (EFAD) diet for 8 weeks caused a significant elevation of TEWL and a significant reduction in covalently bound ceramides in hairless rats. Transmission electron microscopy revealed that the intercellular multilamellar structures in the stratum corneum of treated rats were incomplete (folding, defects, unclear images) compared to the structures seen in the stratum corneum of non-UVB-irradiated and non-EFAD rats. These results suggest that the amount of covalently bound ceramides is highly correlated with the barrier function of the skin, and that covalently bound ceramides play an important role in the formation of lamellar structures, and are involved in the maintenance of the barrier function of the skin.     

Inhibitors of cysteine cathepsin and calpain do not prevent ultraviolet-B-induced apoptosis in human keratinocytes and HeLa cells

Caspases, members of the cysteine protease family, execute UVB-induced apoptosis in several cell lines and keratinocytes. Several researchers investigating UVB-induced apoptosis have demonstrated a dose-dependent protective effect of the synthetic peptide caspase inhibitor zVAD-fmk. However, zVAD-fmk displays a dose-dependent protective effect against UVB-induced apoptosis, even at doses higher than those required to block all known proapoptotic caspases. In addition, it is known that zVAD-fmk also inhibits other cysteine proteases including cathepsins and calpains, and these proteases have recently been demonstrated to play a role in the execution of programmed cell death induced by other stimuli, e.g. TNF-α. The purpose of the present study was therefore to investigate whether inhibitors of cysteine cathepsins and calpains could prevent UVB-induced apoptosis in HeLa cells and keratinocytes. This was done by investigating the effect of the irreversible cysteine protease inhibitor zFA-fmk, the cathepsin B inhibitor CA-074-Me and the calpain inhibitor ALLN on the viability of UVB-irradiated human keratinocytes and HeLa cells. At concentrations of 10 μM and above zVAD-fmk conferred partial dose-dependent protection against UVB-induced apoptosis in HeLa cells and keratinocytes. Moreover, caspase-3 activity was completely blocked at zVAD-fmk concentrations of 1 μM in HeLa cells. This indicates that caspase-independent mechanisms could be involved in UVB-induced apoptosis. However, the protease inhibitors zFA-fmk, CA-074-Me and ALLN all failed to prevent UVB-induced apoptosis in HeLa cells and keratinocytes. In conclusion, the protective effect of zVAD-fmk at high concentrations indicates that other proteases than caspases are active in the execution of UVB-induced apoptosis but further studies are needed to identify these proteases.     

Sunbed use in Buenos Aires, Argentina

The objectives were to survey tanning salons in a defined geographic area of Buenos Aires city and to assess the information offered to consumers regarding chronic exposure to ultraviolet radiation, types of radiation used, and safety measures employed. A prospective study using a standardized interview with limited multiple choice responses for data collection was conducted. Results of the interview survey were that 35% of the establishments (tanning salons) said they used UVA exclusively, 6% UVB, and 25% both; 35% did not know the type of radiation to which their clients were exposed. Sunbeds were promoted as healthy in 56% of the tanning salons, whereas potential risks were mentioned in only 15%. One to 3 sessions on the same day were allowed by 84%, while 40% allowed customers to choose the number of weekly sessions. The use of goggles was optional in 65% of the establishments and 21% did not even provide goggles. Use of sunscreens was not compulsory, and none of the salons had associated physicians. Previous history of skin cancer, sunburn or potential photosensitive drug intake were never recorded, and the age of access was not restricted in 71% of the establishments. In Argentina there are no guidelines to regulate the operation of tanning salon establishments or the equipment they use, and there are no specific measures taken to prevent skin and ocular pathologies. Ways to reduce the risks of ocular and skin pathologies from artificial tanning in Argentina are urgently needed.     

UVB照射对PIG1细胞增殖活性的影响

目的：探讨UVB照射对正常人黑素细胞PIG1细胞形态及增殖活性的影响。方法：取对数生长期的PIG1细胞,分别以50、100、200、300、400、500、600和700mJ/cm2剂量的UVB照射后继续培养0h、24h和48h,在倒置显微镜下观察其形态学变化,用MTT法检测UVB照射对细胞增殖活性的影响。结果：在50～200 mJ/cm2的UVB辐射下,随辐射剂量的增大,PIG1细胞的增殖活性逐渐增加,倒置相差显微镜从形态学上证实了一定剂量的UVB照射可以促进细胞增殖。结论：一定剂量的UVB照射有刺激PIG1细胞增殖及树突生长的作用。     

Structural and biochemical basis for the UVB-induced alterations in epidermal barrier function

Ultraviolet light (UVR) induces a myriad of cutaneous changes, including delayed disruption of the permeability barrier with higher doses. To investigate the basis for the UVB-induced barrier alteration, we assessed the epidermal lamellar body secretory system at various time points before and after barrier disruption with a single high dose of UVB (7.5 MED) to murine epidermis. Morphological data were correlated with changes in epidermal proliferation and lipid synthesis, indicative of lamellar body generation. Twenty-four hours following UVB, the stratum corneum (SC) is normal, but a layer of abnormal, vacuolated, and lamellar body (LB)-deficient cells is present, immediately beneath the stratum granulosum (SG)/SC interface. Immediately subjacent to this band of damaged cells, normal keratinocytes that contain intact LBs are present. By 72 h, concomitant with the appearance of a barrier abnormality, extensively damaged cells persist at the SC/SG interface, and abnormal lamellar membrane structures appear in the lower SC. Upper stratum spinosum (SS) and lower SG cells appear normal, with increased numbers of LBs. A barrier abnormality is still present at 96 h, in association with membrane abnormalities in the lower SC interstices, but up to four normal-appearing, subjacent SG cell layers are present. By 120 h, accelerated LB formation and precocious LB extrusion occur throughout the thickened SG; normal lamellar membranes are present in the lower SC; and barrier recovery is almost complete. Whereas, epidermal synthesis of the major barrier lipid species (i.e., cholesterol, fatty acids, and ceramides, including acylceramides) is reduced or unchanged at 24 and 48 h, it increases significantly 72 h after exposure to UVB. Therefore, the delayed disruption of the permeability barrier following acute UVB exposure results from the arrival of a band of lamellar body-incompetent (i.e., damaged) cells at the SG/SC interface. The subsequent, rapid recovery of the barrier, in turn, results from compensatory hyperplasia of subjacent, undamaged SS/SG cells, generating increased numbers and contents of LB. These results underscore the critical role of the stratum compactum in mediating barrier function, and suggest that beneficial therapeutic effects of UV exposure may be due to enhanced lipid production and barrier regeneration.     

复方丙酸氯倍他索软膏联合UVB治疗寻常型银屑病的临床疗效及护理

目的探讨用复方丙酸氯倍他索软膏联合UVB照射，并配合护理措施治疗寻常型银屑病的临床疗效。方法治疗组于患处外涂复方丙酸氯倍他索软膏，每天2次，行UVB全身照射，1周2～3次，并配合适当的护理措施。对照组于患处外涂复方丙酸氯倍他索软膏，每天2次。根据PASI评分标准评价疗效。结果治疗组有效率88．46％，对照组有效率65．38％，经统计学处理，x^2=7．8000，P〈0．01；治疗组复发率19．05％，对照组复发率53．85％，经统计学处理，x^2=4．4472，P〈0．05。结论复方丙酸氯倍他索软膏联合UVB照射并配合适当的护理措施是治疗寻常型银屑病的有效方法。     

紫外线通过诱导TNF-α胞内聚集间接调控VEGF分泌表达

目的 探讨紫外线(UVB)反应中TNF-α在介导VEGF诱导表达中的作用.方法 采用TNF-α特异性shRNA转染小鼠成纤维细胞(MEFs)并建立稳定细胞株;RT-PCR方法验证TNF-α shRNA的有效性;荧光素酶报道分析系统检测vegf基因启动子活性;ELISA方法检测VEGF的分泌表达水平.结果 本课题组构建的TNF-α shRNA能够有效抑制UVB刺激作用下TNF-α的诱导表达;同样条件下,UVB诱导vegf基因启动子活性上调趋势被TNF-α shRNA显著抑制;同时VEGF的胞外分泌表达水平明显下降.结论 UVB反应中TNF-α可间接介导VEGF的诱导表达.     

玉竹对UVB诱导HaCaT细胞损伤的保护作用

目的:探讨玉竹水提液对中波紫外线(UVB)诱导人皮肤角质形成细胞损伤的保护作用及其可能机制。方法:用64mJ.cm-2的UVB照射人皮肤角质形成细胞建立光老化细胞模型,以不同浓度玉竹提取物处理光老化细胞,羟胺法检测细胞超氧化物歧化酶(SOD)活性,比色法检测谷胱甘肽过氧化物酶(GSH-Px)活性,TBA法检测丙二醛(MDA)含量,酶联免疫法检测肿瘤坏死因子α(TNF-α)、白介素6(IL-6)分泌量。结果:UVB照射角质形成细胞后,SOD、GSH-Px活性降低,MDA含量升高,TNF-α、IL-6分泌量增加(P<0.01),玉竹水提液中(100μg.ml-1)、高(200μg.ml-1)剂量组能显著提高SOD、GSH-Px活性,降低MDA含量,减少TNF-α、I L-6分泌(P<0.05或P<0.01)。结论:玉竹水提液可在一定程度上减轻UVB对角质形成细胞的损伤,其机制可能与其抑制氧化损伤,增强细胞抗氧化能力,减少炎症细胞因子分泌有关。