Skin Bacteria and Skin Disinfection Reconsidered

Large discrepancies in the available data on skin microbiology stimulated investigations of the number, interactions, and location of commensals and the true efficiency of disinfection by using skin biopsy, culture of frozen sections, and other methods.Most current procedures were less than 0·5% as sensitive as the biopsy method described. This gave mean bacterial counts ranging from 4,400/cm² on the breast to 400,000/cm² in the axillae. An iodine preparation removed 95% of accessible organisms, but about 20% of bacteria were protected by follicles, crevices, and lipids. Commensals in over 20% of people produced antibiotics against a wide range of pathogens. Conversely, “satellitism” was demonstrable in 12% of people.     

Radiation Therapy for Skin Cancer

Local control, cosmesis and functional results were evaluated in 315 cases of skin cancer in 247 patients treated with radiation therapy. The initial recurrence rate for basal cell carcinoma was 7.8 percent and for squamous cell carcinoma was 14.9 percent. Ultimate local control was achieved in 98.7 percent of the cases of basal cell carcinoma and in 94.0 percent of the cases of squamous cell carcinoma with use of further irradiation or other therapeutic modalities. Ultimate local control rates were comparable to other therapeutic modalities. Cosmetic and functional results were excellent. Cartilage necrosis was not a significant problem. Radiation therapy may offer advantages in certain clinical situations and should be considered as a mode of therapy in the treatment of skin cancer.     

新型持续皮肤牵张器促进皮肤创面愈合的实验研究

目的：介绍自主研制的持续皮肤牵张器,探讨自主研制的持续皮肤牵张器治疗皮肤缺损的可行性和效果分析。方法：自主研制的持续皮肤牵张器8套;白色家猪6只,将每只猪的背部（两侧）切除矩形皮肤软组织缺损,形成12个创面,分为二组,实验组4只猪8个创面,对照组2只猪4个创面,创面均为10cm×6cm,实验组创面用自制持续皮肤牵张器行皮肤伸展术治疗,对照组创面自行愈合。结果：实验组与对照组每日创面缩小面积相差较多,差异有统计学意义,实验组皮肤缺损行5-6天皮肤伸展术治疗后,可直接行二期缝合关闭,对照组1周后仍存在较大皮肤缺损,无法缝合关闭。结论：应用自制持续皮肤牵张器行皮肤伸展术,可以早期快速闭合皮肤创面。自制持续皮肤牵张器克服了以往牵张器的不足,具有使用方便,效果可靠,并发症少等优点,有良好的应用前景。     

Skin gene therapy for acquired and inherited disorders

The rapid advances associated with the Human Genome Project combined with the development of proteomics technology set the bases to face the challenge of human gene therapy. Different strategies must be evaluated based on the genetic defect to be corrected. Therefore, the re-expression of the normal counterpart should be sufficient to reverse phenotype in single-gene inherited disorders. A growing number of candidate diseases are being evaluated since the ADA deficiency was selected for the first approved human gene therapy trial (Blaese et al., 1995). To cite some of them: sickle cell anemia, hemophilia, inherited immune deficiencies, hyper-cholesterolemia and cystic fibrosis. The approach does not seem to be so straightforward when a polygenic disorder is going to be treated. Many human traits like diabetes, hypertension, inflammatory diseases and cancer, appear to be due to the combined action of several genes and environment. For instance, several wizard gene therapy strategies have recently been proposed for cancer treatment, including the stimulation of the immune system of the patient (Xue et al., 2005), the targeting of particular signalling pathways to selectively kill cancer cells (Westphal and Melchner, 2002) and the modulation of the interactions with the stroma and the vasculature (Liotta, 2001; Liotta and Kohn, 2001).     

Skin and environment

The human skin is one of the major human organs in perpetual interaction with environmental factors. Permanent micro-aggressions by light, mechanical factors or chemical factors are useful for the maintenance of healthy skin. For example light is necessary for vitamin D synthesis and for the control of skin inflammation. If the aggression is too strong, repair mechanisms are involved such as wound healing or DNA repair. Accumulation of aggressions could induce acute or chronic diseases such as sunburn, photoageing or skin carcinoma. On specific individuals with genetic predisposition environmental aggressions can induce frequent diseases such as atopic dermatitis, present in 20% of children or psoriasis, present in 2-3% of the European population. Chemical aggressions are responsible for irritant dermatitis or allergic dermatitis, which are among the most frequent professional diseases. Aggression by UV light is one of the best examples of the interaction between environment and health. At a low dose UV light is very good for the health. At a high dose it is responsible for photoageing and skin carcinoma. To improve the control of environmental factors important for health, two approaches are essential: 1) research into epidemiology to discover the causal relationships and into biology to discover the mechanisms involved; 2) education from childhood to explain the results of research and to propose effective behaviours. For each aggression individuals at risk have to be identified.     

Nanolipidgel for Enhanced Skin Deposition and Improved Antifungal Activity

The purpose of the research was to prepare and evaluate a topical nanolipidgel (NLH) of terbinafine hydrochloride (TRB), an antimycotic agent, for enhanced skin deposition and improved antifungal activity. Topical solid lipid nanoparticles (SLN) based nanolipidgel was formulated and evaluated. TRB-loaded SLNs were formulated by high-pressure homogenization technique. The stable TRB SLN dispersion was incorporated into a gel using 1% Carbopol 980 NF. Rheological evaluation and texture analysis of the TRB NLH was carried out. Skin permeation, skin deposition, antifungal activity, and occlusivity studies of the nanolipidgel formulation were carried out. The safety of the TRB NLH gel was evaluated using acute skin irritation test on New Zealand White rabbits. The SLN dispersion containing 10% of glyceryl monostearate, 3% of Tween 80, and 1% Plurol Oleique was the most stable. The optimized TRB SLN had a particle size and zeta potential value of 148.6 ± 0.305 nm and −20.4 ± 1.2 mV, respectively. TRB NLH had excellent rheological and texture properties to facilitate its topical application. TRB NLH showed increased skin deposition of the drug over plain (3-fold) and marketed TRB formulation (2-fold). TRB NLH had significantly enhanced antifungal activity against Candida albicans. TRB NLH showed efficient occlusivity and was non-irritant to the rabbit skin with no signs of erythema or edema. Solid lipid nanoparticles-based topical nanolipidgel of terbinafine can be an efficient, industrially scalable, and cost-effective alternative to the existing conventional formulations.KEY WORDS: in vitro antifungal activity, rheological analysis of gel, solid lipid nanoparticles, terbinafine, texture analysis of gel     

组织工程皮肤生物反应器的研究与设计

目的设计一套生物反应器,能针对不同支架材料———细胞复合物进行构建组织工程皮肤。方法根据皮肤的自身生长特点和不同支架材料-细胞复合物的特性,模拟皮肤的生长环境和力学环境,通过生物反应器解决组织工程皮肤构建中支架的装夹和气液界面问题。结果生物反应器由控制系统和生物反应器主体两部分构成,能提供对多种皮肤细胞复合物的动态培养。结论皮肤生物反应器能够满足不同组织工程皮肤产品的需要。能够形成气液界面和模拟生物力学的刺激。