Ahmed Elkhyat

Influence of the hydrophobic and hydrophilic characteristics of sliding and slider surfaces on friction coefficient: in vivo human skin friction comparison

Introduction: The objective of this study was to investigate whether hydrophilic/hydrophobic balance (Hi/Ho) of the skin surface strongly modifies the friction coefficient (μ).

Cutaneous differences between Black, African or Caribbean Mixed-race and Caucasian women: biometrological approach of the hydrolipidic film.

Background/purpose: Studies about the adaptation of ethnic types of skin to an environment radically different from their original environment are rarely found in the literature. We have evaluated the differences in the skin surface properties of three ethnic groups: Black, African or Caribbean Mixed‐race and Caucasian women living in defined climatic conditions.

Efficacy of micronutrient supplementation on skin aging and seasonal variation: a randomized, placebo-controlled, double-blind study.

Background Several studies have confirmed dramatic changes in skin surface parameters during the winter months. Although there are many studies supporting the positive effects of topical treatment, there are no published studies demonstrating the effects of oral supplementation in the prevention of negative skin changes during winter. The purpose of this study was to evaluate the efficacy of an oral micronutrient supplement in preventing the negative effects of winter weather on skin quality using noninvasive biometrologic instruments. Methods This study included 80 healthy female volunteers aged 35–55 years with phototype II–IV skin. Randomization was balanced. Two tablets of a micronutrient supplement (Perfectil® Platinum) or placebo were administered once daily for 4 months. The volunteers were examined at baseline, after 4 months, and 6 weeks after termination of treatment (month 5.5). The evaluation included skin microrelief by Visioscan® as the main outcome, and the secondary outcomes were results on standard macrophotography, skin tension by Reviscometer®, skin high-frequency ultrasound, and self-assessment. Results For all pseudoroughness and microrelief indicators, there was a significant increase from baseline to month 4 in the placebo group (P<0.05) but no change in the active group. Descriptive statistics for the mean minimum, mean maximum, and minimum to maximum ratio on the nonexposed study zone showed a significant and dramatic difference between baseline and month 4 and between baseline and month 5.5 (P<0.05) in the active group, indicating decreasing anisotropy of the skin. High-frequency ultrasound on the exposed study zone revealed that skin thickness was significantly decreased in the placebo group during winter but was stable in the treated group (P<0.01). The photography scaling and self-assessment questionnaire revealed no significant changes in either group. Conclusion These results indicate that the skin is prone to seasonal changes during winter, particularly in exposed areas. The data also indicate that oral supplementation can be a safe treatment, with no serious side effects, and may prevent or even eliminate the negative effects of winter on the skin.

Dermal Equivalents in Oncology: Benefit of One-Stage Procedure

BACKGROUND In oncology, dermal equivalent may be indicated to cover losses of substance related to skin tumors or after the removal of skin flaps. OBJECTIVE To report our experience of two dermal equivalents, Matriderm 1 mm with a one‐stage graft (DE1) and Integra DL with a two‐stage graft (DE2) in oncology. PATIENTS AND METHOD Retrospective, single‐center study involving 16 patients. RESULTS Sixteen patients received dermal equivalents as an alternative to flaps (7 cases), over tendinous areas (7 cases), and for cosmetic purposes (2 cases). Twelve patients received DE1 and four DE2. Wound healing times with DE1 were 4 weeks less than those with DE2. Three cases of infection were noted with DE2. The use of dermal equivalents as an alternative to skin flaps was effective, and no adhesions were found over the tendinous areas. CONCLUSION The learning curve, the two‐stage graft required with DE2, and not using a vacuum‐assisted closure system can explain the high infection rate. The use of dermal equivalents is particularly indicated in the treatment of skin defect in oncology. The possibility of a one‐stage graft with DE1 and combination with negative pressure therapy is beneficial.

Assessment of spray application of Saint GERVAIS® water effects on skin wettability by contact angle measurement comparison with bidistilled water

Background: The skin is responsible for protecting the body from physical, chemical and microbial injuries. The stratum corneum is the top layer of the epidermis and it plays a key role in helping to contain moisture. When the skin becomes damaged, its ability to perform these functions is compromised. Dry skin is a common form of skin damage. Contact angle θ between a surface and water is a good indicator of hydrophobic or hydrophilic tendency of surfaces.

Mécano-Stimulation™ of the skin improves sagging score and induces beneficial functional modification of the fibroblasts: clinical, biological, and histological evaluations

Background Loss of mechanical tension appears to be the major factor underlying decreased collagen synthesis in aged skin. Numerous in vitro studies have shown the impact of mechanical forces on fibroblasts through mechanotransduction, which consists of the conversion of mechanical signals to biochemical responses. Such responses are characterized by the modulation of gene expression coding not only for extracellular matrix components (collagens, elastin, etc.) but also for degradation enzymes (matrix metalloproteinases [MMPs]) and their inhibitors (tissue inhibitors of metalloproteinases [TIMPs]). A new device providing a mechanical stimulation of the cutaneous and subcutaneous tissue has been used in a simple, blinded, controlled, and randomized study. Materials and methods Thirty subjects (aged between 35 years and 50 years), with clinical signs of skin sagging, were randomly assigned to have a treatment on hemiface. After a total of 24 sessions with Mécano-Stimulation™, biopsies were performed on the treated side and control area for in vitro analysis (dosage of hyaluronic acid, elastin, type I collagen, MMP9; equivalent dermis retraction; GlaSbox®; n=10) and electron microscopy (n=10). Furthermore, before and after the treatment, clinical evaluations and self-assessment questionnaire were done. Results In vitro analysis showed increases in hyaluronic acid, elastin, type I collagen, and MMP9 content along with an improvement of the migratory capacity of the fibroblasts on the treated side. Electron microscopy evaluations showed a clear dermal remodeling in relation with the activation of fibroblast activity. A significant improvement of different clinical signs associated with skin aging and the satisfaction of the subjects were observed, correlated with an improvement of the sagging cheek. Conclusion Mécano-Stimulation is a noninvasive and safe technique delivered by flaps microbeats at various frequencies, which can significantly improve the skin trophicity. Results observed with objective measurements, ie, in vitro assessments and electron microscopy, confirm the firming and restructuring effect clinically observed.

Development of a new sensor based on micro‐electro‐mechanical systems for objective in vivo measurement of the cutaneous temperature: application to foundations

Background/aims: The purpose of this work was to develop a new sensor for objective in vivo measurement of the cutaneous temperature based on micro‐electro‐mechanical systems (MEMS), and to compare these performances with those of a classical thermocouple. Research on this new sensor was carried out to allow the quantification of the thermal properties of the made‐up skin.

Skin rejecting tattoo ink followed, in vivo, by reflectance confocal microscopy.

M. Mandal a,* A. Gianatti, D. Massi Division of Medical Oncology, Unit of Translational and Clinical Research, Papa Giovanni XXIII Hospital, Bergamo, Italy, Division of Pathology, Papa Giovanni XXIII Hospital, Bergamo, Italy, Division of Pathological Anatomy, Department of Surgery and Translational Medicine, University of Florence, Florence, Italy *Correspondence: Mario Mandal a. E-mail: mariomandala@tin.it