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。     

Impact of defensins-containing body cream on skin composition

Background and Aims

Defensins are peptides capable of reactivating latent LGR6 stem cells in the basal layer. When applied topically, these peptides can reduce signs of skin aging and increase dermal thickness. This study investigates the effects of a topical defensin formulation on extremity skin composition.

Methods

An open label, single arm clinical trial was conducted on participants with dry, photoaged, or dull skin. A defensin-containing hand and body cream was applied twice daily for 6 weeks to the hands, forearms, elbows, and knees. Photographs and objective measurements of skin hydration, viscoelasticity (VE), retraction time (RT), thickness, density/transepidermal water loss (TEWL), as well as self-evaluation of skin quality and characteristics were obtained pre- and post- intervention.

Results

After the study period, RT decreased by 56% across all body sites (p < 0.001) and VE improved at the elbow (125%, p = 0.009) and knee (110%, p < 0.001). Skin density also increased in all 4 body sites (40%, p < 0.001), while skin thickness increased at the elbow (29%, p = 0.03) and knee (17%, p = 0.04). Skin hydration increased at the elbow, knee, and forearm by 99%, 28%, and 16%, respectively (p < 0.05), while TEWL improved at the elbow only (−39%, p = 0.02). Patients' self-evaluations showed improvements in overall skin quality and in the domains of dryness, ashiness, wrinkling, pigmentation, redness, roughness, and discomfort (p < 0.05).

Conclusions

Following 6-week use of a defensin-containing cream, subjects reported significant improvement across many subjective skin domains. Similarly, objective measurements demonstrated significant improvement in skin architecture at select sites.     

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.     

Glove powder affects skin roughness, one parameter of skin irritation

Most patients with immediate-type-hyper sensitivity to natural rubber latex (NRL) give a history of hand eczema. Susceptibility to allergens is increased by irritant hand eczema due to damage to the skin barrier. Therefore, especially for employees in medical or paramedical professions, reduction in skin irritation is of importance. The present study reports the effect of glove powder on skin roughness, one feature of skin irritancy. Skin replicas, performed before and after wearing different types of gloves, were evaluated by laser profilometry. Significant alteration of skin roughness was evident and determined by different factors. Use of unpowdered Biogel gloves on prepowdered hands results in an increase in skin roughness, in contrast to the use of Biogel gloves on hands without any pre-application. On the other hand, powdered Manex neoderm gloves show no influence on the skin structure, whereas powdered Peha taft gloves also increase the roughness of the skin. Other potential candidates causing skin morphology alteration could be the glove pH, rubber chemicals with irritant potential and other characteristics of gloves, which are already under investigation.     

Age-dependent changes in skin surface assessed by a novel two-dimensional image analysis

Background/purpose: Skin microrelief has been studied using various methods and devices. However, the long duration of time needed to process one sample or the expensive equipment hampered the use of those systems for routine diagnosis. Today, the emergence of new software and hardware technologies may allow this issue to be resolved.
Methods: To characterize objectively the skin surface, we introduced a new parameter SPm , namely, the area mean of superficial skin texture block formed by primary and secondary lines crossing each other. Based on the skin detector produced by the Boseview Technology Company, we developed a software for acquiring automatically skin images and calculating SPm . The relationship between SPm and age was studied on the dorsal and ventral midway of the forearm (sun-exposed and sun-protected areas) of 94 healthy volunteers without a history of smoking.
Results: The skin surface topography can be conveniently quantified with the new parameter SPm . The value of SPm of both sites increases with age, independent of sex, with the site more exposed to light being more affected.
Conclusion: With the software developed, the details of the skin surface can be observed. SPm appears to be a new valid parameter for characterizing the property of the skin surface. Our method, alone or in combination with other technologies of skin topography analysis may be applied in routine diagnosis for a quantified evaluation of skin aging.     

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...     

Neural basis of sensitive skin: an fMRI study

Background/purpose: About 50% of women declare themselves to have sensitive skin. However, sensitive skin still appears to be a questionable problem not corresponding to a specific physiological pattern. To objectivate the neural basis of sensitive skin, we measured cerebral response to cutaneous provocative tests in self‐perceived sensitive and non‐sensitive skin subjects using functional magnetic resonance imaging (fMRI). Methods: Subjects were divided into two groups according to their self‐perceived characterization by using a dedicated questionnaire about their skin reactivity. Event‐related fMRI was used to measure cerebral activation associated with skin discomfort induced by a simultaneous split‐face application of lactic acid and of its vehicle. Results and discussion: In both groups, skin discomfort due to lactic acid increased activity in the primary sensorimotor cortex contralateral to application site and in a bilateral fronto‐parietal network including parietal cortex, prefrontal areas around the superior frontal sulcus, and the supplementary motor area. However, activity was significantly larger in the sensitive skin group. Most remarkably, in the sensitive skin group only, activity spreaded into the ipsilateral primary sensorimotor cortex and the bilateral peri‐insular secondary somatosensory area. Our results demonstrate that, compared with control subjects, self‐perceived sensitive skin subjects have a specific cerebral activation during skin irritative test, which allows us to hypothesize that self‐perceived sensitive skin is intrinsically linked to a specific neurophysiologic pattern for these subjects. Conclusion: This study demonstrates that fMRI is an effective objective method for measuring cerebral processes underlying skin reactivity and contributes to a better understanding of the neural basis of the sensitive skin phenomenon.