痤疮患者皮肤生理功能测定

目的 探讨痤疮患者面部皮肤生理功能的特点，以期指导痤疮患者的治疗。方法 选取受试对象120例，试验组为痤疮患者60例，其中男20例，女40例，平均年龄23.4岁；对照组为健康志愿者60例，其中男20例，女40例，平均年龄25.1岁。运用无创性皮肤生理功能测试仪，测量受试者的面颊及T区（油脂分泌旺盛区域）皮肤油脂、面颊皮肤弹性和水分。结果 试验组面部T区油脂量为（199.98 ± 58.21） μg/cm2，健康对照组为（117.55 ± 63.16） μg/cm2，两组差异有统计学意义（t = 7.34，P < 0.05）。试验组面颊油脂量为（154.45 ± 55.06） μg/cm2，健康对照组为（87.50 ± 47.36） μg/cm2，两组差异有统计学意义（t = 7.14，P < 0.05）。试验组皮肤弹性（0.7931 ± 0.0755R）与健康对照组（0.7882 ± 0.0498R）比较，差异无统计学意义（P > 0.05），试验组皮肤水分（30.75% ± 3.87%）与健康对照组（30.94% ± 2.91%）比较，差异也无统计学意义（P > 0.05）。结论 痤疮患者颜面皮肤油脂分泌过多。     

主观皮肤类型与皮肤屏障功能的关系

目的:比较不同主观皮肤类型(油性、中性和干性皮肤)屏障功能指标的差异。方法:利用无创性方法对自评为油性、中性和干性皮肤的20~25岁北京城市女性(各30例)进行皮脂分泌率(SER)、角质层含水量、p H值和经皮肤水分丢失(TEWL)值的检测,并采用胶带连续粘脱后监测TEWL值变化的方法评价角质层完整性,采用角质层取样蛋白定量的方法评价角质层黏合力和丝氨酸蛋白酶活性。结果:主观皮肤类型为中性皮肤者具有最佳的屏障功能;干性皮肤和油性皮肤者面颊部的屏障功能均有不同程度的受损,表现为TEWL值明显升高、p H值升高、丝氨酸蛋白酶活性增加;但二者也有区别,油性皮肤者角质层完整性下降更明显,而干性皮肤主要是角质层黏合力明显减弱。结论:自评为油性和干性皮肤者与中性皮肤者相比,屏障功能均存在一定程度的缺陷,油性皮肤与干性皮肤均具有不同特点,且与其屏障受损的机制不同有关。     

Formulation optimization, skin irritation, and efficacy characterization of a novel skin-lightening agent

Background Skin‐lightening preparations are used by people all over the world for a diverse range of dermatologic indications. The gold standard treatment for skin lightening is with hydroquinone but has been controversial because of the presence of several side effects. Therefore, there has been a constant search for developing new treatment alternatives. Furthermore, the new amendments and bans on animal testing by ECVAM have made the three‐dimensional models like EpiDerm^? and MelanoDerm^? increasingly popular. Objective This work aims at the formulation development for a new skin‐lightening agent, SMA‐012, followed by testing for skin irritation and efficacy. Methods Formulation parameters such as concentration of SMA‐012, amount of ethanol, effect of permeation enhancers and pH were first optimized using Franz cell experiments. Tape stripping and underlying skin assays were performed to analyze the amounts of SMA‐012 in different layers of skin. The irritation potential and efficacy of the screened formulation were evaluated using Epiderm^? and Melanoderm^? models. Results Skin permeation experiments suggested that concentrations of 0.1% SMA‐012, 35% ethanol, and pH of 8.5 to be the best formulation characteristics. This particular formulation was found to be nonirritant for short‐term exposure, when tested in Epiderm^? model and also significantly effective in decreasing the amount of melanin in pigmented skin equivalent models. Conclusion SMA‐012 shows a good promise as a skin‐lightening agent for cosmetic and therapeutic applications. Additionally, our study demonstrates the application of skin equivalent models as alternatives to animal testing in studying the regulation of skin pigmentation.     

An improved human skin explant culture method for testing and assessing personal care products

Background

Cultured human skin models have been widely used in the evaluation of dermato-cosmetic products as alternatives to animal testing and expensive clinical testing. The most common in vitro skin culture approach is to maintain skin biopsies in an airlifted condition at the interface of the supporting culture medium and the air phase. This type of ex vivo skin explant culture is not, however, adequate for the testing of cleansing products, such as shampoos and body washes. One major deficiency is that cleansing products would not remain confined on top of the epidermis and have a high chance of running off toward the dermal side, thus compromising the experimental procedure and data interpretation.

Materials and Methods

Here, we describe an improved ex vivo method for culturing full-thickness human skin for the effective testing and evaluation of skin care products by topical application.

Results

This newly developed ex vivo human skin culture method has the ability to maintain healthy skin tissues for up to 14 days in culture. Importantly, the model provides a quick and safe way to evaluate skin care products at different time points after single or repetitive topical applications using a combined regimen of leave-on and wash-off. We found that the results obtained using the new skin culture method are reproducible and consistent with the data collected from clinical testing.

Conclusion

Our new ex vivo skin explant method offers a highly efficient and cost-effective system for the evaluation and testing of a variety of personal care products and new formulations.     

神经酰胺与相关皮肤病的研究进展

神经酰胺（ceramide,Cer）由长链鞘氨醇碱和脂肪酸组成,参与皮肤屏障的构成、调节皮肤免疫及细胞周期、分化与凋亡等过程。神经酰胺的合成代谢异常与多种皮肤疾病相关，如特应性皮炎、银屑病等。本文就神经酰胺与相关皮肤病的研究进展进行综述。     

含牛油果树果脂等植物成分的保湿产品改善皮肤干燥的安全性及有效性评价

目的：探讨一种含牛油果树果脂等植物成分的保湿产品改善皮肤干燥的临床有效性和安全性。方法：采用前瞻性多中心自身前后对照试验进行研究,共收集196例受试者。受试者在双侧小腿胫前皮肤使用该保湿产品,每日1次,共14 d。分别在使用前、使用后1 h、4 h、24 h、7 d及14 d进行受试区皮肤生理指标检测及干燥程度的主观评分。结果：受试者单次使用研究产品后1 h、4 h及24 h,受试区皮肤角质层含水量较基线水平显著增加,分别升高17.11±6.72、13.98±6.36、10.79±6.28（P<0.001）,保湿时效≥24 h。使用7 d和14 d后,角质层含水量分别为41.18±8.70和43.48±8.84,较基线水平（26.53±8.68）明显升高;经皮水分丢失分别为（6.48±2.33）g/h/m²和（6.46±3.43）g/h/m²,较基线水平[（7.36±3.96）g/h/m²]减少;pH值改变分别为5.28±0.60和5.37±0.53,较基线水平（5.51±0.70）降低并保持稳定;皮肤干燥程度主观...     

Development and characterization of a canine skin equivalent

The development of a complex cellular model, which incorporates the basic cell components of the dog skin, would be a useful tool to investigate the biology and pathology of canine skin and also to replace animal testing partially. The aim of the present study was to develop and characterize a canine skin equivalent. Epidermal keratinocytes and dermal fibroblasts were freshly isolated from skin biopsies from healthy dogs. Fibroblasts were embedded into a bio-matrix from collagen type I matrix protein; this built the scaffold where the keratinocytes were seeded, at air exposed conditions. At 3, 7, 15 and 21 days of culture in special growth media, skin equivalents were analysed by histological, immunohistochemical and electron microscopical techniques. At 15 days, keratinocytes underwent differentiation to a multilayer epidermis with stratum basal, stratum spinosum, stratum granulosum and stratum corneum. Expression of epidermal cytokeratins in keratinocytes was detected by immunhistochemistry, and followed the same pattern than in the normal canine epidermis. Fibroblasts from the skin equivalent expressed vimentin as dermal fibroblasts do. A basement membrane (BM) was observed underneath the epidermis; ultrastructurally, it was similar to the normal canine BM and collagen IV and laminin 5 were detected immunohistochemically as major components of this structure. Skin equivalents developed from canine cutaneous cells presented a similar morphological structure than healthy canine skin. Moreover, the immunohistochemical analysis revealed the expression of the major markers of the epidermis (keratins), dermis (vimentin) and BM (collagen type IV, laminin 5).     

Nicotinamide and the skin

Nicotinamide, an amide form of vitamin B3, boosts cellular energy and regulates poly‐ADP‐ribose‐polymerase 1, an enzyme with important roles in DNA repair and the expression of inflammatory cytokines. Nicotinamide shows promise for the treatment of a wide range of dermatological conditions, including autoimmune blistering disorders, acne, rosacea, ageing skin and atopic dermatitis. In particular, recent studies have also shown it to be a potential agent for reducing actinic keratoses and preventing skin cancers.     

Assessment of skin lesions and skin cancer using simple electrical impedance indices

Background/aims: Purpose of this investigation was to assess benign pigmented cellular nevus (BEN), basal cell carcinoma (BCC), dermatofibroma (DER), dysplastic nevus (DYS), and seborrheic keratoses (SEB) using in vivo non- invasive electrical impedance technique.
Methods: Electrical impedance was measured at 258 BEN, 34 BCC, 17 DER, 35 DYS, and 26 SEB lesions. Controls were measured at healthy skin close to the lesions. The impedance was measured between 1 kHz and 1 MHz at five depth settings. After the impedance measurements the lesions were histopathologically diagnosed. The impedance spectra were parameterized to four indices prior to the statistical analysis of the data.
Results: There were significant differences between the lesions and their controls for BEN ( P  < 0.001), BCC ( P  < 0.001), DYS ( P  < 0.01), and SEB ( P  < 0.01).
Conclusions: There are clear statistical differences between impedance of common lesions and control skin. With some further developments, the impedance technique can be useful as a diagnostic decision support tool for skin cancer assessment.