Stratum corneum drying drives vertical compression and lipid organization and improves barrier function in vitro.

The stratum corneum dehydrates after exogenous hydration due to skincare or bathing. In this study, sheets of stratum corneum were isolated from reconstructed human epidermis and the barrier function and structure of these sheets were assessed during drying with the aim of improving our understanding of skincare. Water diffusion through the sheets of stratum corneum decreased with drying, accompanied by decreased thickness and increased visible light transmission through the sheets.

Relationship between perceived softness of bilayered skin models and their mechanical properties measured with a dual-sensor probe.

The development of a sensor system that can predict the subjective softness of human skin is an important goal for the cosmetics industry. Here, we first carried out a subjective softness evaluation test using 65 skin models consisting of polyurethane bilayers with different thickness of the superficial layer and different degree of cross-polymerization of the basal layer. The results showed that perceived softness was dependent on the mechanical properties of both the superficial and basal layers.

Kallikrein-related peptidase-7 regulates caspase-14 maturation during keratinocyte terminal differentiation by generating an intermediate form.

The maturation and activation mechanisms of caspases are generally well understood, except for those of caspase-14, which is activated at the onset of keratinocyte terminal differentiation. We investigated the possible involvement of epidermal proteases expressed in the late stage of differentiation, and found that the chymotrypsin-like serine protease kallikrein-related peptidase-7 (KLK7) cleaved procaspase-14 at Tyr(178), generating an intermediate form that consists of a large (20 kDa) and a small subunit (8 kDa). We prepared an antibody directed to this cleavage site (h14Y178 Ab), and confirmed that it recognized a 20-kDa band formed when procaspase-14 was incubated with chymotrypsin or KLK7.

Near-infrared imaging of water in human hair.

Background/purpose: The water content of hair can be evaluated by weighing, the Karl Fischer method, and from electrical properties. However, these methods cannot be used to study the distribution of water in the hair. Imaging techniques are required for this purpose.

Softness sensor system for simultaneously measuring the mechanical properties of superficial skin layer and whole skin.

Background/aims: Few attempts have been made to distinguish the softness of different skin layers, though specific measurement of the superficial layer would be useful for evaluating the emollient effect of cosmetics and for diagnosis of skin diseases.

Materials And Methods: We developed a sensor probe consisting of a piezoelectric tactile sensor and a load cell. To evaluate it, we firstly measured silicone rubber samples with different softness.

Ultraviolet light-induced changes of lymphatic and blood vasculature in skin and their molecular mechanisms.

Ultraviolet light in the 290- to 320-nm wavelength range (UVB) induces angiogenesis and lymphatic dysfunction in skin. This review deals with UVB-induced alterations to the blood and lymphatic systems in skin and the molecular mechanisms involved. We also discuss potential strategies to block photoageing of skin by inhibiting angiogenesis and/or promoting lymphatic vascular function.

A missense mutation within the helix initiation motif of the keratin K71 gene underlies autosomal dominant woolly hair/hypotrichosis.

Woolly hair (WH) is an abnormal variant of tightly curled hair, which is frequently associated with hypotrichosis. Non-syndromic forms of WH can show either autosomal-dominant WH (ADWH) or autosomal-recessive WH (ARWH) inheritance patterns. ARWH has recently been shown to be caused by mutations in either the lysophosphatidic acid receptor 6 (LPAR6) or lipase H (LIPH) gene.

Light source spectrum strongly influences the in vitro estimation of sun protection factor.

Irradiation from an artificial solar simulator that matches the relative cumulative erythema effectiveness (RCEE) of sunlight is used for in vivo sun protection factor (SPF) testing, whereas irradiation that matches the spectrum of natural sunlight (NS) is generally used for in vitro SPF testing. This study was designed to clarify whether this difference is important. Eight sunscreens spread on artificial substrates and several optical filters as sunscreen mimics were used.

Relation between working memory performance and evoked cerebral blood oxygenation changes in the prefrontal cortex evaluated by quantitative time-resolved near-infrared spectroscopy.

Objectives: The lateral prefrontal cortex (LPFC) plays a central role in working memory (WM). In the present study, we employed quantitative, near-infrared time-resolved spectroscopy (TRS) to evaluate the relation between LPFC activity during WM and the task performance in 19 healthy, middle-aged, female subjects (mean age of 46·8±2·1 years).

Methods: Concentration changes of oxyhemoglobin (oxy-Hb), deoxyhemoglobin, and total hemoglobin in the bilateral LPFC were measured by means of TRS during performance of Sternberg tests (ST) of one digit and six digits.

Improvement of skin surface texture by topical estradiol treatment in climacteric women.

Background: Hormone replacement therapy (HRT) has been widely applied to climacteric women to improve various climacteric symptoms. Purpose of the present study is to reveal the effect of topical HRT with estradiol on skin surface texture (SST), a major determinant of skin appearance.

Methods: Estradiol 1.

Involvement of upper cheek sagging in nasolabial fold formation.

Background: Nasolabial folds are a well-known feature of aging, but the mechanism of their formation remains unclear.

Objectives: To clarify the mechanism of nasolabial fold formation, we established grading criteria for severity and explored the influence of dermal elasticity and subcutaneous adipose mass. We also investigated the involvement of facial morphological changes, such as wrinkling and sagging.

Influence of application amount on sunscreen photodegradation in in vitro sun protection factor evaluation: proposal of a skin-mimicking substrate.

Widely used polymethylmethacrylate substrates for in vitro sun protection factor (SPF) testing of sunscreens do not mimic the rough surface structure of skin, and in addition, sample loading is less than that used in in vivo SPF testing (2.00 mg cm(-2)). We have developed a skin-mimicking substrate (SMS), which has furrows and ridges on its surface, like human skin.

Hyperpigmentation in human solar lentigo is promoted by heparanase-induced loss of heparan sulfate chains at the dermal-epidermal junction.

Background: Skin pigmentation induced by ultraviolet B radiation is caused in part by inflammation mediated by cytokines secreted from keratinocytes and fibroblasts in the irradiated area. Heparanase is also activated in the irradiated skin, and this leads to loss of heparan sulfate at the dermal-epidermal junction (DEJ), resulting in uncontrolled diffusion of heparan sulfate-binding cytokines through the DEJ. However, it is not clear whether heparanase-induced loss of heparan sulfate at the DEJ is involved in the pigmentation process in sun-exposed skin.

Large-scale production of saikosaponins through root culturing of Bupleurum falcatum L. using modified airlift reactors.

Modification of internal configuration of a bubble column, airlift and stirred tank reactor (10-200 L) was made for root cultures of Bupleurum falcatum L. Agitation with an impeller covered with partition mesh was ineffective for a 10-L modified reactor, because it caused intensive foaming and subsequent overflow of the culture medium even at a low rotation speed of 50 rpm and a low aeration rate of 0.1 vvm (volume per volume of medium).

Key role of heparan sulfate chains in assembly of anchoring complex at the dermal-epidermal junction.

Epidermal basement membrane forms anchoring complex composed of hemidesmosomes, anchoring filaments, lamina densa and anchoring fibrils to link epidermis to dermis. However, the anchoring complex is rarely formed in skin equivalent models, probably because of degradation of extracellular matrix (ECM) proteins and heparan sulfate chains by matrix metalloproteinases (MMPs) and heparanase, respectively. To explore the roles of ECM proteins and heparan sulfate in anchoring complex assembly, we used specific inhibitors of MMPs and heparanase, and the formation of anchoring complex was analysed in terms of polarized deposition of collagen VII, BP180 and β4 integrin at the dermal-epidermal junction (DEJ) by means of immunohistochemistry and transmission electron microscopy (TEM).

Extended range near-infrared imaging of water and oil in facial skin.

Recently, near-infrared (NIR) imaging has been applied to detecting changes in skin hydration using the water OH band centered near 1460 nm. However, assigning changes in the intensity of the OH band near 1460 nm to changes in the skin's water content is complicated. Consequently, detection of small changes in facial skin water content is difficult.

Dermal carbonyl modification is related to the yellowish color change of photo-aged Japanese facial skin.

Background: The photo-aged facial skin is characterized by various unique features such as dark spots, wrinkles, and sagging. Elderly people, particularly Asians, tend to show a yellowish skin color change with photo-aging. However, there has been no analytical study conducted on this unique skin color change of the aged facial skin.

Negative regulation of dermal fibroblasts by enlarged adipocytes through release of free fatty acids.

Subcutaneous adipose tissue lies just beneath the dermal layer, but the interaction between the two types of tissue remains obscure. Recently, we reported that obesity is associated with decreased dermal elasticity. To investigate the mechanism of the adipose tissue/dermal interaction, fibroblasts were cocultured with small or enlarged adipocytes, using a membrane insert to prevent direct contact.

Morphological and functional differences in coculture system of keratinocytes and dorsal-root-ganglion-derived cells depending on time of seeding.

Previous study indicated that in a coculture system of keratinocytes and dorsal-root-ganglion-derived (DRG) cells, mechanical stimulation of keratinocytes induced ATP-mediated calcium propagation and excitation of DRG cells. Here, we examined two different coculture systems of keratinocytes and DRG cells. In one, we seeded keratinocytes first and then seeded DRG cells on the keratinocytes.

Comparison of sagging at the cheek and lower eyelid between male and female faces.

Background: Facial sagging is a well-known morphological feature associated with aging and reduced dermal elasticity. Its morphological characteristics and mechanism have been studied in females, but it is unclear whether or not there is a gender difference.

Aims: The aim of this study was to clarify the morphological characteristics of sagging and the mechanism of sagging formation in male faces as compared with female faces, focusing on changes in dermal elasticity.

Roles of transient receptor potential proteins (TRPs) in epidermal keratinocytes.

Epidermal keratinocytes are the epithelial cells of mammalian skin. At the basal layer of the epidermis, these cells proliferate strongly, and as they move towards the skin surface, differentiation proceeds. At the uppermost layer of the epidermis, keratinocytes undergo apoptosis and die, forming a thin, water-impermeable layer called the stratum corneum.

Sex difference in human fingertip recognition of micron-level randomness as unpleasant.

We investigated sex difference in evaluation, using the human fingertip, of the tactile impressions of three different micron-scale patterns laser-engraved on plastic plates. There were two ordered (periodical) patterns consisting of ripples on a scale of a few micrometres and one pseudo-random (non-periodical) pattern; these patterns were considered to mimic the surface geometry of healthy and damaged human hair, respectively. In the first experiment, 10 women and 10 men ran a fingertip over each surface and determined which of the three plates felt most unpleasant.

Phosphorylcholine (PC)-bonded protein A affinity chromatographic medium for high-throughput purification with reduced non-specific protein adsorption.

A protein A affinity chromatographic medium based on porous silica modified with phosphorylcholine (PC) groups and amino groups (PNSP) was synthesized. The PC groups functioned as suppressors of non-specific protein adsorption. Recombinant protein A was bound to the amino groups on PNSP with a glutaraldehyde used as a spacer (PNSP-PA).