Intensification of ultraviolet-induced dermal damage by infrared radiation

Summary Abnormal dermal deposition of elastic fibers is the earliest and most striking effect of prolonged sun exposure (solar elastosis). The hyperplastic fibers are usually ascribed to ultraviolet (UV) rays. Nonetheless, other portions of the solar spectrum may play contributing roles. Heat, for example, enhances experimental UV tumorigenesis. Heat induces erythema ab igne in which the structural alterations resemble those of actinically damaged skin, including the development of premaligant and malignant lesions. In regions of high insolation, infrared radiation (IR) is a constant companion of UV. To assess the role of IR in actinic damage to the dermis, albino guinea pigs were irradiated for 45 weeks with UV-B and UV-A, with and without IR. Control animals received IR only or no irradiation at all. Unirradiated dermis contains small amounts of elastic fibers in the upper dermis with greater depositions around follicles and sebaceous glands. After irradiation with UV, the fibers became more numerous, thicker, and more twisted; IR alone produced many fine, feathery fibers. The addition of IR to UV resulted in dense matlike elastic fiber depositions that exceeded what was observed with either irradiation alone. In combination or alone UV and IR radiation produced a large increase in ground substance, a finding also seen in actinically damaged human skin. Infrared radiation, in the physiologic range, though pleasant is not innocuous.     

Tungiasis infestation of dermis fat graft in an anophthalmic socket

A patient with an anophthalmic socket with a dermis-fat graft (DFG) developed inflammation and a foul odour in the right socket. The DFG was surgically removed and Tungiasis infestation was detected. This is the first case to report Tungiasis infestation in a DFG in an anophthalmic socket.     

不同来源胶原蛋白对人真皮成纤维细胞生长的影响

目的:探讨不同来源胶原蛋白对体外培养人真皮成纤维细胞(HDF-a细胞)生长的影响.方法:用不同浓度、不同来源胶原蛋白的培养基培养HDF-a细胞,考察样品对体外HDF-a细胞生长的影响.结果:12批不同来源胶原蛋白中,4批样品能抑制HDF-a细胞生长,其他8批样品则能促进HDF-a细胞的生长.结论:胶原蛋白对HDF-a细...     

小鼠真皮间充质干细胞对硬皮病成纤维细胞胶原分泌和TGF-β1表达的影响

目的:研究体外小鼠真皮间充质干细胞(mdMSCs)与硬皮病患者皮损区成纤维细胞(hsFb)共培养对其胶原成分分泌和转化生长因子β1(TGF-β1)表达的影响,探讨MSCs对硬皮病治疗的可能性。方法:采用低血清培养基,消化-贴壁-传代法体外培养、鉴定mdMSCs,并与体外分离培养的hsFb或正常人成纤维细胞(hnFb)于Transwell培养体系中共培养,样本碱水解法和ELISA法分别检测第4、8 d培养上清液中羟脯氨酸(Hyp)和TGF-β1的变化。结果:第8 d单独培养的hsFb上清液Hyp、TGF-β1含量较hnFb高(P<0.05);经各细胞密度mdMSCs处理的hsFb培养上清液中Hpy含量与单独培养时无显著差异;经mdMSCs 2.5×104处理的hsFb培养组,在共培养第4 d上清液TGF-β1含量较单独培养时明显增高(P<0.05),第8 d时与单独培养比较无明显差异(P>0.05)。共培养组Hyp含量与TGF-β1水平无明显相关(r=0.221,P>0.05);单独培养组Hyp含量与TGF-β1水平有正相关关系(r=0.682,P<0.01)。结论:体外mdMSCs与hsFb共培养未能有效减少Hyp和TGF-β1的分泌,提示mdMSCs不能通过对hsFb的作用达到治疗硬皮病的目的。     

Human dermal fibroblast isolation using two enzyme digestion methods: A comparative study北大核心

BACKGROUND: Dermal fibroblasts are widely used and demanded, and there are various isolation methods, but no comparative studies on enzyme digestion methods are reported. OBJECTIVE: To compare the cell count, morphology, migration and proliferation of human dermal fibroblasts isolated by two enzyme digestion methods. METHODS: Human dermal fibroblasts were isolated using either dispase-collagenase or trypsin, and their cell yield and viability were assessed by morphology, cell count and proliferation curve by cell counting-kit 8 assay. The ability of migration was observed by cell scratch test. RESULTS AND CONCLUSION: The fibroblasts digested with dispase-collagenase were fused at 6-7 days after inoculation, and the cells isolated by trypsin digestion were fused at 8-9 days after inoculation. Fibroblasts could be obtained by both two digestion methods. The production in the dispase-collagenase group was significantly higher than that in the trypsin group. The migration rate in the dispase-collagenase group was significantly faster than that in the trypsin group. The growth cures of the human dermal fibroblasts in the two groups revealed that the cell count was positively correlated with time, and the absorbance values of the dermal fibroblasts in the dispase-collagenase group were significantly higher than those in the trypsin group at 3, 4 and 5 days after incubation. To conclude, the cell yields, migration and proliferation of dermal fibroblasts digested with dispase-collagenase are significantly higher than those of the cells digested by trypsin, indicating that dispase-collagenase digestion results in better isolation and viability of dermal fibroblasts from the dermis. © 2018, Journal of Clinical Rehabilitative Tissue Engineering Research. All rights reserved.     

Gene expression profiling of negative-pressure-treated skin graft donor site wounds

Negative-pressure wound therapy (NPWT) is widely used to improve skin wound healing. Although NPWT has been studied as a treatment for wound closure and healing, the molecular mechanisms explaining its therapeutic effects remain unclear. To investigate the effect of NPWT on gene expression, and to discover the genes most dominantly responding to this treatment during skin wound healing, we applied negative pressure on split-thickness skin graft donor sites from the first postoperative day (POD) to the seventh POD. Biopsies were collected from 4 NPWT-treated and 2 control patients. Two biopsy samples were taken from each patient: one from intact skin before graft harvesting, and one on the seventh POD from the donor site wound. Genome-wide microarrays were performed on all samples. Gene expression changes on the seventh POD were compared between NPWT and control patients, and were analyzed for statistical significance. In addition, we analyzed wound exudates for volume, and for concentrations of leukocytes, erythrocytes, and haemoglobin. NPWT induced major changes in gene expression during healing. These changes ranged from 10-fold induction to 27-fold suppression. The genes most induced were associated with cell proliferation and inflammation, and the most down-regulated genes were linked to epidermal differentiation. Our results provide the first insight into the molecular mechanisms behind NPWT, and suggest that NPWT enhances specific inflammatory gene expression at the acute phase associated with epithelial migration and wound healing. However, its continued use may inhibit epithelial differentiation.     

Construction of bilayered tissue-engineered skin with human amniotic mesenchymal cells and human amniotic epithelial cells

Human amniotic mesenchymal cells (hAMCs) and human amniotic epithelial cells (hAECs) have attracted increasing attention in recent years as a possible reserve of stem cells that may be useful for clinical application in regenerative medicine. The object of this study was to establish a new model for reconstruction of bilayered tissue-engineered (TE) skin with hAMCs and hAECs (amniotic cells TE skin, AC-TE skin). We studied these two types of cells and confirmed that they possessed the properties of stem cells. Mesenchymal-epidermal interactions are responsible for organogenesis. On the basis of this mechanism, we modified the constructing methods of traditional TE skin (TE skin with human fibroblasts and keratinocytes) and then established a new bilayered TE skin-AC-TE skin. Histological and immunochemical methods were carried out to assess AC-TE skin. The results showed that AC-TE skin was similar in morphology to human skin which had stratified epidermis and underlying dermis. AC-TE skin expressed proliferative cells marker Ki67 and epithelial stem cells marker K19; moreover, the constructed AC-TE skin could successfully repair full thickness skin defects on athymic mice. Our findings suggest that AC-TE skin is a useful skin equivalent which has good application prospects in regenerative medicine.     

A 35-month profilometric and clinical evaluation of non-ablative remodeling using a 1540-nm Er:glass laser

BACKGROUND/OBJECTIVE: As remodeling is getting more popular with patients, long-term studies are becoming necessary. The aim of this 35-month clinical study was to evaluate the long-term benefits obtained using a 1540-nm Er:glass laser for non-ablative remodeling of perioral and periorbital rhytids. The role of maintenance treatments was also investigated. STUDY DESIGN/METHODS: Eleven women with periorbital and perioral rhytids underwent a series of five treatments at 6-week intervals with an Er:glass laser. Five patients subsequently received two maintenance retreatments and six did not. The maintenance treatments were performed at 14 and 20 months. Silicone imprints were performed to measure anisotropy before treatment, at 6 months, at 14 months and at 35 months. Patient self-evaluation/questionnaire was also done to assess adverse effects and subjective clinical improvement. RESULTS: For all 11 patients, the percentage of anisotropy reduction was 41.21% at 6 months, 51.76% at 14 months and 29.87% at 35 months. No adverse effects were noted. Patient satisfaction was high at the end of the evaluation. Retreated patients were more satisfied than non-retreated ones. However, there was no difference in the anisotropy factor between the two groups. CONCLUSION: Treatment of facial rhytids with a non-ablative 1540-nm Er:glass laser system can produce benefits that persist over 2 years after the last treatment.     

少年儿童皮肤厚度的超声学测量

目的用无创的方法获得少年儿童皮肤厚度资料。方法选择221例1～18岁皮肤健康的少年儿童，按年龄分为幼儿组（1～2岁）、学龄前期组（3～6岁）、学龄期组（男7～12岁、女7～11岁）、青春期组（男13～18岁、女12～18岁），各年龄组下分男、女2个性别组。应用13MHz高频超声，检测上述人员面部、胸部、腹部、背部、前臂、臀部、大腿7个部位的皮肤表皮、真皮与全层皮肤厚度。结果221例少年儿童的皮肤以面部较薄，背部及臀部较厚。（1）各年龄组的同一部位以及同一年龄组中男、女同一部位的表皮厚度相近（P〉0．05）。（2）幼儿组、学龄前期组与学龄期组同一部位组间比较，以及组内不同性别同一部位比较，真皮和皮肤全层厚度相近（P〉0．05）。与其余3组比较，青春期组此2项指标均明显偏高（P〈0、05），男性真皮厚度为（1.16±0．04）～（1．98±0．47）mm、皮肤全层厚度为（1.27±0．12）～（2．20±0．45）mm，女性真皮厚度为（1．00±0.18）～（1.60±0.30）mm、皮肤全层厚度为（1.10±0.17）～（1、83±0．29）mm。结论13MHz高频超声是无创测量少年儿童皮肤厚度的有效方法。青春期少年全层皮肤厚度增加的主要因素系真皮厚度明显增加，且男性较女性更为显著。面部与背部、臀部皮肤厚度的明显差异，对皮肤移植术具有指导意义。