Qualification of an automated device to objectively assess the effect of hair care products on hair shine.

The authors developed and qualified an automated routine screening tool to quantify hair shine. This tool is able to separately record individual properties of hair shine such as specular reflection and multiple reflection, as well as additional features such as sparkle, parallelism of hair fibers, and hair color, which strongly affect the subjective ranking by individual readers. A side-by-side comparison of different hair care and styling products with regard to hair shine using the automated screening tool in parallel with standard panel assessment showed that the automated system provides an almost identical ranking and the same statistical significances as the panel assessment.

Qualification of a new and precise automatic tool for the assessment of hair diameters in phototrichograms.

Background/purpose: To automatically assess hair growth during cosmetic trials, incorporating parameters such as anagen-to-telogen rate, growth rate, and especially hair diameter.

Methods: We designed and qualified a new and automatic phototrichogram system based on a high-resolution DSLR camera system (theoretical resolution of 2.557 μm/pixel) and modular macrolens system with fixed focus, combined with a trainable pattern recognition software for automated analysis.

Validation of the body scanner as a measuring tool for a rapid quantification of body shape.

Background: Currently, the body scanner, using laser-triangulation, is one of the most precise measuring tools for the rapid quantification of body shape. The VITUS body scanner is a laser-based system based on a principle called triangulation and the scan produced describes the distance to a surface at each point in the picture. The body scanner has multiple applications such as determining body measurements for tailoring, anthropometric investigations and cosmetic surgery.

Non-invasive monitoring of oxidative skin stress by ultraweak photon emission measurement. II: biological validation on ultraviolet A-stressed skin.

Background/purpose: Several physical or chemical environmental stressors generate reactive oxygen species, which trigger oxidation reactions of cells or tissues and thereby induce a correlated ultraweak photon emission (UPE) signal. The present study was designed to qualify and validate UPE measurement following ultraviolet (UV) excitation of porcine and human skin as an analytical method to assess the potency of topical antioxidants in vivo.

Methods: UPE of porcine skin in vitro and human skin in vivo following excitation with UVA was recorded using sensitive photomultiplier systems.

Non-invasive monitoring of oxidative skin stress by ultraweak photon emission (UPE)-measurement. I: mechanisms of UPE of biological materials.

Background/purpose: Oxidation of proteins and amino acids is associated with generation of ultraweak photon emission (UPE), which may be used to assess oxidative processes in the skin in a non-invasive way. This first part of a series of reports addresses the physicochemical basis of oxidation-induced UPE in the skin, with a special focus on the contribution of amino acid oxidation.

Methods: UPE of biological samples and protein/amino acid solutions following oxidation with H(2)O(2) in the presence of Fe(2+) was recorded using a sensitive photomultiplier system.

Nitric oxide regulates synthesis of gene products involved in keratinocyte differentiation and ceramide metabolism.

During terminal differentiation of keratinocytes the expression of various proteins, which are required for the formation of the epidermal water barrier in the skin of land dwelling animals, is upregulated. Using a cell culture model for the differentiation of human keratinocytes and real-time PCR, we quantified the mRNA levels of several proteins involved in differentiation and ceramide metabolism. A calcium shift (1.

Stratum corneum pH in atopic dermatitis: impact on skin barrier function and colonization with Staphylococcus Aureus.

Recent studies have provided new insights into the occurrence, causes, and pathogenetic consequences of changes in the skin pH in atopic dermatitis, particularly with respect to skin barrier function and colonization with Staphylococcus aureus. Growing evidence suggests an impaired release of proton donors, such as amino acids, urocanic acid, and lactic acid, to the stratum corneum in atopic dermatitis, as a result of reductions in filaggrin proteolysis and sweat secretion. In addition, an impaired formation of free fatty acids from sebaceous lipids and epidermal phospholipids seems to be involved.

Role of taurine accumulation in keratinocyte hydration.

Epidermal keratinocytes are exposed to a low water concentration at the stratum corneum-stratum granulosum interface. When epithelial tissues are osmotically perturbed, cellular protection and cell volume regulation is mediated by accumulation of organic osmolytes such as taurine. Previous studies reported the presence of taurine in the epidermis of several animal species.

The acidic milieu of the horny layer: new findings on the physiology and pathophysiology of skin pH.

The acidic pH of the horny layer, measurable on the skin surface, has long been regarded as a result of exocrine secretion of the skin glands. The 'acid mantle' was thought to regulate the bacterial skin flora and to be sensitive primarily to skin cleansing procedures. In recent years, an increasing number of investigations have been published on the changes in, and constituents and functions of, the pH of the deeper layers of the stratum corneum, as well as on the influence of physiological and pathological factors.