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。     

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。     

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.     

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.     

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.     

Proteomic analysis identifies new biomarkers for postmenopausal and dry skin

A proteomic analysis of stratum corneum (SC) samples of normal healthy skin revealed the presence of more than 70 proteins by 2D electrophoresis. The majority of these proteins to our knowledge have not yet been described in normal SC. We analysed by Western blot the levels of 25 proteins in the SC taken from postmenopausal and dry skin compared with young and normal skin, respectively. In postmenopausal skin, there was a significantly increased amount of heat shock protein 27, plakoglobin and desmoglein 1, whereas transglutaminase 3, apolipoprotein D and acid ceramidase levels were significantly reduced compared with the SC of young skin. We confirmed corneodesmosin as a marker of dry skin. In addition, we showed for the first time that the levels of both phosphatidylethanolamine-binding protein 1 and annexin A2 were significantly increased in the SC of dry skin compared with the SC of normal skin. These results suggest that a proteomic analysis of the SC obtained using a non-invasive varnish stripping method is an attractive alternative to invasive methods to better characterize changes in the physiology of ageing and dry skin.     

The relationship between skin function,barrier properties,and body‐dependent factors

Background

Skin is a multilayer interface between the body and the environment, responsible for many important functions, such as temperature regulation, water transport, sensation, and protection from external triggers.

Objectives

This paper provides an overview of principal factors that influence human skin and describes the diversity of skin characteristics, its causes and possible consequences. It also discusses limitations in the barrier function of the skin, describing mechanisms of absorption.

Methods

There are a number of in vivo investigations focusing on the diversity of human skin characteristics with reference to barrier properties and body‐dependent factors.

Results

Skin properties vary among individuals of different age, gender, ethnicity, and skin types. In addition, skin characteristics differ depending on the body site and can be influenced by the body‐mass index and lifestyle. Although one of the main functions of the skin is to act as a barrier, absorption of some substances remains possible.

Conclusions

Various factors can alter human skin properties, which can be reflected in skin function and the quality of everyday life. Skin properties and function are strongly interlinked.

     

New vision in fractional radiofrequency technology with switching,vacuum and cooling

Introduction: Since the introduction of fractional technology, various systems were launched to the market. The first generation of fractional RF systems created epidermal ablation with coagulative/necrosis of the dermis with sufficient clinical outcomes, but with some limitations. The aim of this study was to evaluate the efficacy and safety of SVC technology, based on the principle of separate biological responses. Material and methods: Fifty-two patients were treated for 3–6 sessions using fractional RF handpiece and eight patients received combination treatments with non-invasive RF handpiece. Results: All volunteers showed notable to significant improvement in the photoageing symptoms, without any significant complications or adverse events. Discussion: Due to its wide spectrum of parameters, the SVC technology can promote different biological responses. Owing to the “Switching” technology, the control of energy depth penetration enables delivery of the necessary thermal dose to the targeted skin layer. In addition, this novel technology includes the “Vacuum” and “Cooling” mechanisms, each contributing to the safety of the treatment. The Smart Heat function reduces the necessary energy levels and thereby reduces the pain level and risks for side effects.     

夜间皮肤瘙痒及治疗进展

瘙痒是皮肤科最常见的临床症状。国内外对其发生机制进行了大量的研究,提出瘙痒的发生主要由无髓C纤维介导,其对组胺及热敏感,并与一系列瘙痒介质的参与有关［1］。临床工作中发现,瘙痒常在夜间发作或明显加重［２］,患者通常描述瘙痒位于原有皮损处或全身性发作,无明确定位。Yosipovitch等［1］报道,65%的炎症性皮肤病患者夜间感觉瘙痒加重,其中包括银屑病、特应性皮炎及慢性特发性荨麻疹。另外,系统性疾病的患者,如慢性肾功能衰竭及造血系统疾病患者等也感觉夜间皮肤瘙痒加重［２－３］。夜间皮肤瘙痒的认识和处理成为临床工作的重要内容……     

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。     

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).