A Spectrophotometric Method to Determine Minimal Erythema Dose for Ultraviolet Radiation in Human Skin.

: Ultraviolet radiation (UVR) induces oxidative stress in the skin by generating reactive oxygen species (ROS), which can lead to inflammatory conditions including erythema (a sign of sunburn). This clinical study aims to develop an instrumental evaluation method to determine the minimal erythema dose (MED) for UVR. : Fourteen human subjects aged 27 to 57 years (48.

An analysis of shapes and location of anterior hairline in Asian men.

An individual's first impression can be influenced by a number of esthetic factors, one of which is a natural hairline. The anterior hairline can be affected by various factors, such as race, age, forehead shape, and hair loss progression, similar to androgenetic alopecia. Information on the shape, hairline location on the forehead, and race are required to classify the anterior hairline.

Dynamic Evaluation of Microwound Healing Induced by a Fractional CO Laser Using Reflectance Confocal Microscopy.

Background: A model for evaluating the skin wound healing process over time is needed. Wound healing can be evaluated using reflectance confocal microscopy (RCM), which permits the dynamic characterization of the skin in a noninvasive manner.

Objective: The aim of this study was to analyze the healing process of fractionally induced microwounds using RCM.

Early detection of microcomedones induced by cocoa butter using reflectance confocal microscopy.

Background: Many ingredients used in cosmetics evoke a comedogenic response. The concept of ''acne cosmetica'' was developed to link the use of certain ingredients to comedone formation. Various clinical research methods have been suggested for the effective screening of an ingredient that can worsen acne or acneiform eruption and confirm its clinical relevance as to whether it is used as a non-comedogenic claim.

Clinical Evidence of Effects of Lactobacillus plantarum HY7714 on Skin Aging: A Randomized, Double Blind, Placebo-Controlled Study.

The beneficial effects of probiotics are now widely reported, although there are only a few studies on their anti-aging effects. We have found that Lactobacillus plantarum HY7714 (HY7714) improves skin hydration and has anti-photoaging effects, and in the present study, we have further evaluated the anti-aging effect of HY7714 via a randomized, double blind, placebo-controlled clinical trial. The trial included 110 volunteers aged 41 and 59 years who have dry skin and wrinkles.

4-n-butylresorcinol dissolving microneedle patch for skin depigmentation: a randomized, double-blind, placebo-controlled trial.

Background: For effective skin depigmentation, the skin depigmentation agent must be delivered to melanocytes, where melanin is synthesized. Although dissolving microneedle (DMN) is one of the best transdermal drug delivery systems to deliver the active compound, no clinical trial has been conducted in terms of safety and efficacy.

Objectives: To assess the clinical efficacy and safety of a DMN patch that contained 4-n-butylresorcinol, a skin depigmentation agent.

Identification of a possible susceptibility locus for UVB-induced skin tanning phenotype in Korean females using genomewide association study.

A two-stage genomewide association (GWA) analysis was conducted to investigate the genetic factors influencing ultraviolet (UV)-induced skin pigmentation in Korean females after UV exposure. Previously, a GWA study evaluating ~500 000 single nucleotide polymorphisms (SNPs) in 99 Korean females identified eight SNPs that were highly associated with tanning ability. To confirm these associations, we genotyped the SNPs in an independent replication study (112 Korean females).

A study of the human skin-whitening effects of resveratryl triacetate.

Resveratrol has a variety of bioactivities that include its anti-melanogenic effects, but its use in cosmetics has been challenging partly because of its chemical instability. Resveratryl triacetate (RTA) is a prodrug that can enhance stability. The purpose of this study was to examine the skin safety and whitening effects of RTA in human subjects.

The Atopic Dermatitis Antecubital Severity score: validity, reliability, and sensitivity to change in patients with atopic dermatitis.

Background: The Atopic Dermatitis Antecubital Severity (ADAS) score is a new objective scale for the assessment of the severity of atopic dermatitis (AD). It is calculated by multiplying the intensity of inflammatory signs by the size of an antecubital eczema lesion.

Aim: To test the validity, reliability, and sensitivity to changes of the ADAS score compared with those of the Eczema Area and Severity Index (EASI) score.

A validation study to find highly correlated parameters with visual assessment for clinical evaluation of cosmetic anti-cellulite products.

Background/purpose: There has been growing interest in cellulite on parts of the body; however, no objective assessment has been specifically established. This study aims to demonstrate an optimized method by comparing the existing assessments of cellulite.

Methods: In Test 1, for subjects of 20 healthy females who have cellulite, we measured volume and roughness of cellulite using fringe projection method, roughness using replica method, dermo-subcutaneous interface length and subcutaneous thickness using ultrasonography and skin temperature using infrared ray, elasticity and blood flow.

Characterization of microthermal zones induced by fractional radiofrequency using reflectance confocal microscopy: a preliminary study.

Background: The microthermal zone (MTZ) produced by fractional device have been mostly evaluated through histopathologic analysis. Study of ablative type MTZ created by fractional device and skin thermal interaction using in vivo reflectance confocal microscopy (RCM) has been rarely reported.

Objectives: We evaluated the in vivo human RCM skin images of ablated fractional radiofrequency (RF) treatment to demonstrate the thermal interaction between RF and skin tissue.

Analysis of the temporal change in biophysical parameters after fractional laser treatments using reflectance confocal microscopy.

Background: Fractional photothermolysis is a popular treatment option for photorejuvenation. Previous literature studies have demonstrated the clinical effectiveness of fractional photothermolysis on cutaneous photoaging; however, the associated changes in biophysical properties of the skin following fractional photothermolysis have not been fully elucidated. This study was conducted to investigate the temporal changes in biophysical parameters after fractional laser treatment on Asian skin.

Reduction of facial wrinkles depth by sleeping on copper oxide-containing pillowcases: a double blind, placebo controlled, parallel, randomized clinical study.

Background: Copper up-regulates the secretion of extracellular skin proteins and stabilizes the extracellular matrix once formed. As copper can be absorbed through intact skin, we reasoned that sleeping on pillowcases containing copper-impregnated fibers would reduce skin wrinkles.

Objective: Demonstrate that sleeping on pillowcases containing copper-impregnated fibers reduce facial skin wrinkles.

Cosmetic efficacy evaluation of an anti-acne cream using the 3D image analysis system.

Background/purpose: Acne is a skin disease which accompanies pathological and morphological changes. Although acne severity is scored by clinicians based on pathological status, aesthetic aspect of acne symptom is also concerned by patients. This study was conducted to examine the usefulness of a 3D image analysis method for the cosmetic efficacy evaluation of an anti-acne cream.

Use of non-melanocytic HEK293 cells stably expressing human tyrosinase for the screening of anti-melanogenic agents.

Tyrosinase (TYR) from mushrooms has been inappropriately used in the screening assay for hypopigmenting agents even though its biochemical properties are different from those of human TYR. Cell-free extracts of human epidermal melanocyes (HEMs) could be another choice for the assay, but HEMs grow too slowly to get a sufficient amount of cell-free extracts. In the present study, human embryonic kidney (HEK) 293 cells were transfected with a human TYR construct to establish a cell line that grows rapidly and expresses human TYR constitutively.

Comparison of the antimelanogenic effects of p-coumaric acid and its methyl ester and their skin permeabilities.

Background: p-Coumaric acid (PCA) inhibits human tyrosinase (TYR) activity and melanin synthesis in human epidermal melanocytes.

Objective: The purpose of the current study was to examine the potential of PCA and its hydrophobic derivative, methyl p-coumarate (MPC), as hypopigmenting agents for topical use.

Methods: PCA and MPC were comparatively tested against in vitro human TYR enzyme activity and cellular melanin synthesis in human epidermal melanocytes.

p-coumaric acid not only inhibits human tyrosinase activity in vitro but also melanogenesis in cells exposed to UVB.

Tyrosinase (TYR) catalyzes rate-limiting steps of melanogenesis and thus its inhibitors are potentially useful as hypopigmenting agents. Recently, p-coumaric acid (p-CA) has been suggested to interfere with the pro-melanogenic actions of tyrosine due to its structural similarity with tyrosine (An SM et al., Br J Dermatol 2008.

Inhibition of melanogenesis by tyrosinase siRNA in human melanocytes.

Tyrosinase (TYR) plays a critical role in cellular melanogenesis and, thus, has been the major target of pharmacological approaches for the control of skin pigmentation. This study examined an alternative molecular approach using TYR-small interfering RNA (siRNA) to control melanogenesis in the human melanocytes. Both the mRNA and protein levels of TYR were significantly lowered by TYR-siRNA treatment, whereas TYR-related protein 1 and TYR-related protein 2 displayed no such changes.

Cigarette smoking associated with premature facial wrinkling: image analysis of facial skin replicas.

Background: Despite the obvious relation between smoking and facial wrinkling, grossly undetectable wrinkling and the consequences of smoking on the face have been poorly studied.

Objective: To assess the risk factor of cigarette smoking on the development of premature facial wrinkling.

Methods: One hundred and twenty-three nonsmokers, 160 current smokers, and 67 past smokers, aged 20-69 years, were studied.