Comprehensive analysis of elemental distribution in human skin using laser ablation inductively coupled plasma mass spectrometry.

Background: Multiple chemical elements play roles in skin homeostasis. The distribution of elements in skin has been studied by X-ray microanalysis methods and fluorescence microscopy using chemical indicators, but the former requires complicated sample preparation steps, while the latter is limited by the availability of suitable chemical indicators.

Materials And Methods: We applied laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to measure the distributions of thirty-eight elements in human skin.

Red light-promoted skin barrier recovery: Spatiotemporal evaluation by transepidermal potential.

The light-promoted recovery of epidermal barrier of skin was evaluated by the associated recovery of transepidermal potential (TEP), the potential difference between the surface and dermis of skin, by using porcine skin samples. An accelerated recovery of TEP was observed by irradiation of red light with the irradiance of 40 mW/cm2 and a duration of > 10 min. The influence of the light stimulation to the surroundings (~ 20 mm) was also observed.

Tranexamic acid blocks the thrombin-mediated delay of epidermal permeability barrier recovery induced by the cedar pollen allergen, Cry j1.

We previously demonstrated that Cry j1, the major pollen allergen of Cryptomeria japonica (Japanese cedar), transiently increases protease activity and intracellular Ca concentration in cultured human keratinocytes, and delays recovery after stratum corneum barrier disruption in human skin ex vivo. Topical application of tranexamic acid or trypsin-type serine protease inhibitors accelerates barrier recovery. We hypothesized that tranexamic acid might prevent the transient protease activity increase and the barrier recovery delay induced by Cry j1.

Visualization of viscoelastic behavior in skin equivalent using optical coherence tomography-based straingraphy.

Background/purpose: The relationships between the skin components and these mechanical roles are still unclear. To clarify these relationships, we investigated spatial mapping of the mechanical behavior of cultured skin equivalents (SEs) using optical coherence tomography (OCT)-based straingraphy.

Methods: We built a strain relaxation test system combined with OCT and developed an algorithm that could visualize a time-dependent strain distribution, named dynamic-optical coherence straingraphy (D-OCSA).

3,4-Dihydroxyphenylacetic acid is a predominant biologically-active catabolite of quercetin glycosides.

Since dietary flavonoid glycosides, including quercetin 4'-glucoside from onion, are poorly absorbed from the gastrointestinal tract, they are converted into smaller phenolic acids, which can be absorbed into the circulation. The purpose of this study was to compare the effects of the major phenolic acid catabolites of quercetin 4'-glucoside, including 3,4-dihydroxyphenylacetic acid (DOPAC), 3-hydroxyphenylacetic acid, 3,4-dihydroxybenzoic acid (protocatechuic acid) and hippuric acid, on the antioxidant activity and phase II cytoprotective enzyme induction in vitro. Both DOPAC and protocatechuic acid, having a catechol moiety, exhibited both DPPH radical scavenging and superoxide dismutase-like activities, whereas 3-hydroxyphenyl acetic acid and hippuric acid did not.

Heparanase Inhibitors Facilitate the Assembly of the Basement Membrane in Artificial Skin.

Recent research suggests that the basement membrane at the dermal-epidermal junction of the skin plays an important role in maintaining a healthy epidermis and dermis, and repeated damage to the skin can destabilize the skin and accelerate the aging process. Skin-equivalent models are suitable for studying the reconstruction of the basement membrane and its contribution to epidermal homeostasis because they lack the basement membrane and show abnormal expression of epidermal differentiation markers. By using these models, it has been shown that reconstruction of the basement membrane is enhanced not only by supplying basement membrane components, but also by inhibiting proteinases such as urokinase and matrix metalloproteinase.

Characterization and mechanisms of photoageing-related changes in skin. Damages of basement membrane and dermal structures.

Sun-exposed skin is characterized by superficial changes such as wrinkles, sagging and pigmentary changes, and also many internal changes in the structure and function of epidermis, basement membrane (BM) and dermis. These changes (so-called photoageing) are predominantly induced by the ultraviolet (UV) component of sunlight. Epidermis of UV-irradiated skin produced several enzymes such as matrix metalloproteinases (MMPs), urinary plasminogen activator (uPA)/plasmin and heparanase, which degrade dermal collagen fibres and elastic fibres in the dermis, and components of epidermal BM.

The effect of calprotectin on TSLP and IL-25 production from airway epithelial cells.

Background: Calprotectin is a heterodimer complex of the S100A8 and S100A9 proteins, and has various functions as an innate mediator at the sites of inflammation. The aim of this study was to elucidate the roles of calprotectin in the eosinophilic chronic rhinosinusitis (ECRS).

Methods: Allergen-induced production of calprotectin was evaluated in cultured normal human bronchial epithelial (NHBE) cells by ELISA and RT-PCR.

Analysis of absorption and spreading of moisturizer on the microscopic region of the skin surface with near-infrared imaging.

Background/purpose: Near-infrared (NIR) light with high water absorption enables us to visualize the water content distribution appeared in the superficial skin layer. The light penetration depth with the wavelength of 1920 nm is almost 100 μm from the skin surface. Thus, the water distribution in the stratum corneum can be effectively imaged by detecting the wavelength band around 1920 nm.

Antiedema effects of Siberian ginseng in humans and its molecular mechanism of lymphatic vascular function in vitro.

The lymphatic system in the skin plays a major role in tissue fluid homeostasis, in the afferent phase of the immune response, and in tumor metastasis. Although lymphangiogenic factors involved in embryonic development and the metastatic spread of tumor cells have been well studied, little is known about small-molecule compounds that activate lymphatic function, especially under physiological conditions. We hypothesized that the identification of a lymphatic-activating compound could provide a method for improving edema.

Facial expression under stiff stratum corneum leads to strain concentrations, followed by residual wrinkle formation.

Objective: Computer simulation studies of skin models, which indicate skin compression in the same manner as facial expressions, have suggested that stratum corneum could control skin-folding patterns, which may play an essential role in wrinkle formation. However, it is not clear to what extent the mechanics of stratum corneum influence wrinkle formation in vivo. The aim of this study was to verify that stratum corneum could control strain distribution during facial expressions, which in turn leads to wrinkle formation.

Efficacy and possible mechanisms of topical tranexamic acid in melasma.

Background: Tranexamic acid (TA) has been suggested as an effective treatment for melasma.

Aim: To investigate the effects and mechanism of action of topical TA in the treatment of melasma.

Methods: In this study, 23 participants with melasma applied a 2% TA formulation to the whole face for 12 weeks.

Comparative study on prediction performance of photosafety testing tools on photoallergens.

Several testing methods have been established to identify potential phototoxins. The present study was undertaken to clarify the predictive ability of in vitro photosafety assays for photoallergenicity. On the basis of animal and/or clinical photosafety information, 23 photoallergens and 7 non-phototoxic/non-photoallergenic chemicals were selected and subjected to UV/VIS spectral analysis, reactive oxygen species (ROS)/micellar ROS (mROS) assays, and 3T3 neutral red uptake phototoxicity testing (3T3 NRU PT).

Mathematical model for calcium-assisted epidermal homeostasis.

Using a mathematical model of the epidermis, we propose a mechanism of epidermal homeostasis mediated by calcium dynamics. We show that calcium dynamics beneath the stratum corneum can reduce spatio-temporal fluctuations of the layered structure of the epidermis. We also demonstrate that our model can reproduce experimental results that the recovery from a barrier disruption is faster when the disrupted site is exposed to air.

Effects of Cosmetic Therapy on Cognitive Function in Elderly Women Evaluated by Time-Resolved Spectroscopy Study.

With the rapid increase in dementia in developed countries, it is important to establish methods for maintaining or improving cognitive function in elderly people. To resolve such problems, we have been developing a cosmetic therapy (CT) program for elderly women. However, the mechanism and limitations of CT are not yet clear.

Development of an in vitro photosensitization test based on changes of cell-surface thiols and amines as biomarkers: the photo-SH/NH₂ test.

As a part of our studies to develop a cell-based in vitro photosensitization assay, we examined whether changes of cell-surface thiols and amines on human monocytic cell line THP-1 could be used to predict photosensitizing potential of chemicals. First, we identified a suitable ultraviolet A (UV-A) irradiation dose to be 5.0 J/cm(2) by investigating the effect of UV-A on the levels of cell-surface thiols and amines in ketoprofen (KP; a representative photoallergen)-treated THP-1 cells.

Preparation and Thermal Properties of Fatty Alcohol/Surfactant/Oil/Water Nanoemulsions and Their Cosmetic Applications.

Physicochemical properties of oil-in-water (O/W) emulsions containing fatty alcohols and surfactants have been investigated with the aim of developing new formulations that are less viscous and more transparent than conventional milky lotions, as well as for providing greater skin-improving effects. O/W-based creams can be converted to low viscosity milky lotions following their emulsification with a homogenizer at temperatures greater than the transition temperatures of their molecular assemblies (α-gel). The stability of the O/W emulsions evaluated in the current study increased as the transition temperatures of the molecular assemblies formed from their fatty alcohol and surfactant constituents increased.

A new quantitative evaluation method for age-related changes of individual pigmented spots in facial skin.

Background: Facial skin pigmentation is one of the most prominent visible features of skin aging and often affects perception of health and beauty. To date, facial pigmentation has been evaluated using various image analysis methods developed for the cosmetic and esthetic fields. However, existing methods cannot provide precise information on pigmented spots, such as variations in size, color shade, and distribution pattern.

Development of novel in vitro photosafety assays focused on the Keap1-Nrf2-ARE pathway.

Although photoallergens require UV energy for antigen formation, the subsequent immune response is considered to be the same as in ordinary skin sensitization. Therefore, in vitro tests for skin sensitization should also be applicable for photoallergy testing. In this study, we examined whether activation of the Keap1 (Kelch-like ECH-associated protein 1)-Nrf2 (nuclear factor-erythroid 2-related factor 2)-ARE (antioxidant response element) pathway could be used to assess the photoallergenic potential of chemicals, using the reporter cell line AREc32 or KeratinoSens(TM) .

Topical adenosine increases the proportion of thick hair in Caucasian men with androgenetic alopecia.

Adenosine is an effective treatment for androgenetic alopecia (AGA) in Japanese men and women. Adenosine exerts its effects by significantly increasing the proportion of thick hair. In this study, we assessed the clinical outcome of adenosine treatment for 6 months in 38 Caucasian men.

Japanese Cedar (Cryptomeria japonica) pollen allergen induces elevation of intracellular calcium in human keratinocytes and impairs epidermal barrier function of human skin ex vivo.

Cry j1 is the major peptide allergen of Japanese cedar (Sugi), Cryptomeria japonica. Since some allergens disrupt epidermal permeability barrier homeostasis, we hypothesized that Cry j1 might have a similar effect. Intracellular calcium level in cultured human keratinocytes was measured with a ratiometric fluorescent probe, Fura-2 AM.