Clinical study on the effects of a cosmetic product on dermal extracellular matrix components using a high-resolution multiphoton tomograph.

BACKGROUND/PURPOSE: The aim of this study was to demonstrate the effects of selected plant extracts in a cosmetic cream on the dermal network components after a 3-month treatment using an in vivo multiphoton tomographic device. METHODS: Twenty-four Caucasian women aged between 45 and 65 applied randomly a cosmetic emulsion B containing active ingredients (soy and jasmine) twice a day on one arm and its vehicle A (without active ingredients) on the other arm during 3 months. Measurements were performed on the internal side of the forearm before starting the treatment (T0), after 4 week (T4) and 12 weeks (T12) treatment. Measurements consisted of a multi-layers acquisitions using a multiphoton tomograph with subcellular resolution. Optical sections (about 6 microm thick) were recorded from 0 to about 200 microm using two different wavelengths: 760 and 820 nm. To compare the series of images and obtain an objective quantification of the signal of second harmonic generation (SHG) and autofluorescence, the method used consisted of taking the integrated brightness of an image (same rectangular area for all images) as a measure of the signal. Following this step, a ratio between brightness of images from the area treated with cream A or B and brightness of untreated area was calculated and used as an assessment of treatment efficacy. The parameter used for statistical analysis (variance analysis) is the difference before and after 12 weeks of treatment by either cream A or B of the signal ratios calculated in the upper dermis (118-130 microm) and those from a deeper region of the upper dermis (165-178 microm). RESULTS: Signals (autofluorescence+SHG) of extracellular matrix do not change significantly with time (weeks 0, 4 and 12) when cream A (vehicle with no active ingredient) is applied. Treatment with cream B results in an enhancement in the signal level of extracellular matrix at week 12. The comparison of signals, in both areas (118-130 microm and 160-178 microm), show an higher increase in the deeper region than in the more superficial one for product B while we do not notice any change with product A. CONCLUSION: The multiphoton tomograph provided excellent high-resolution images, which describe clearly the different skin layers, single cells and extracellular matrix components in all the 24 volunteers. Statistic analyses reveal a real effect for product B with selected plant extracts, known to increase collagen synthesis. Changes observed are characteristics of modifications in dermal collagen and elastin content. To our knowledge, it is the first time that it was possible to demonstrate in vivo the effect of a cosmetic product on the superficial dermal layer, in a non-invasive and non-destructive process, i.e. without cutting the skin.

[Dental extraction in patients with bleeding disorders. Proposal of a protocol based on the type of anesthesia used]. / Extractions dentaires chez les patients porteurs d'un trouble de l'hémostase. Proposition d'un protocole basé sur le type d'anesthésie nécessaire.

INTRODUCTION: The authors propose a protocol to avoid bleeding complications in patients with bleeding disorders. MATERIAL AND METHOD: When a general anesthesia or trunk nerve infiltration is indicated, clotting factor concentrates are to be used in patients with severe bleeding disorders. Desmopressin is to be used in patients with mild bleeding disorders but who are good responders and in patients with thrombopathy. An antifibrinolytic treatment and a fibrin glue are also used. Ninety-six patients underwent 107 extractions with this protocol. RESULTS: Only two patients had bleeding complications requiring an additional treatment. DISCUSSION: In case of bleeding disorders, the treatment depends on disease severity and type of anesthesia. A general treatment (clotting factor concentrates or desmopressin) is indicated with general anesthesia and with local anesthesia in severe bleeding disorders, but not absolutely necessary with local anesthesia in mild bleeding disorders. However, desmopressin can used in all good responders.

Assessment of topical non-steroidal anti-inflammatory drugs.

A new non-invasive technique for assessing the efficacy of topical non-steroidal anti-inflammatory drugs (NSAID) in man is proposed. The NSAID are initially applied to the skin under occlusion before inflammation is induced by a methyl nicotinate solution. The inflammatory response is quantified in terms of cutaneous blood flow by a laser Doppler velocimeter (LDV). The efficacy of NSAID preparations is calculated by comparing the responses of the LDV to the methyl nicotinate challenge on the pretreated and the non-treated skin sites. This protocol has been used to investigate the effect of three different NSAID preparations (indomethacin, niflumic acid, palmitoyl collagenic acid) and the influence of the vehicle on the efficacy of indomethacin. The three preparations tested gave positive results but with different amplitudes in response. The efficacy of indomethacin varied with the vehicle used.