Exploitation of long-lasting ultraweak photon emission to estimate skin photodamage after ultraviolet exposure.

Background: Establishing a noninvasive method to estimate skin damage immediately after ultraviolet (UV) exposure is required to minimize the anticipated severe symptoms triggered by early phase UV-induced reactions in the skin. To develop a suitable method, we focused on ultraweak photon emission (UPE) immediately after UV exposure to characterize the relationship of UPE to skin photodamage caused by the UV exposure.

Materials And Methods: Analysis of the correlation between UV-induced UPE and erythema formation characterized by skin redness was conducted in a clinical study.

Evaluation of unique elastic aggregates (elastic globes) in normal facial skin by multiphoton laser scanning tomography.

Background: There is no reliable marker to estimate the degree of skin aging in vivo. It now has become possible to quantitatively determine the dermal characteristics of the extracellular matrix (ECM) in vivo using multiphoton laser tomography (MLT).

Methods: Fifty-seven healthy Japanese female volunteers, aged from 20 to 60 years old, were examined using multiphoton depth-resolved measurements of autofluorescence (AF) and second harmonic generation (SHG) at three sites on their right cheek.

Seasonal and annual variation in the intensity of facial wrinkles.

Background/aims: We studied annual, seasonal and gender-dependent changes in the intensity of facial wrinkles.

Methods: The study included 32 Japanese subjects (16 men, 16 women, aged 35-47). Wrinkles on the forehead, corner of the eye, lower eyelid and nasolabial groove of each subject were captured in photos and in replicas at 3-month intervals from March, 2009 to March, 2010.

Gender-dependent differences in degree of facial wrinkles.

Background/purpose: This study aimed to reveal gender-dependent differences in the degree of facial wrinkles.

Methods: Subjects comprised 173 Japanese men and women, divided into four groups according to age. Photographs were taken from nine facial regions and used to classify the intensity of wrinkles into five grades.

A new method for the visualization and quantification of internal skin elasticity by ultrasound imaging.

Background/purpose: Skin elasticity has been assessed previously only in the surface layer. We developed a new method that uses tissue strain imaging (TSI) technology, and the aim of this study was to test this new method to assess internal skin elasticity.

Methods: Using a pressure device with a 12 MHz ultrasound transducer, constant and linear compressions were applied to the cheek skin of 35 volunteers (aged: 20-60 years).

Relationship between the echogenicity of subcutaneous tissue and the depth of forehead wrinkles.

Background/purpose: Subcutaneous tissue is rarely studied in research on wrinkles. We used diagnostic ultrasonography to produce images of subcutaneous tissue of the forehead, one of the areas where age-related wrinkles form. We quantified the resulting echogenicity and investigated its relationship with wrinkle depth.

Relationship between the echogenicity of subcutaneous tissue and the depth of eye corner wrinkles.

Background/purpose: A close relationship was found between the internal structure of subcutaneous tissue and wrinkle depth in our previous study of human forehead. The present study examined the relationship in the eye corner.

Methods: One hundred and seventy-three Japanese subjects were divided into four age groups (21-28 years, 35-41 years, 47-59 years and 65-75 years).

Evaluation of photoaging in facial skin by multiphoton laser scanning microscopy.

Background/purpose: It has been reported that autofluorescence (AF) and second harmonic generation (SHG) generated in the upper dermis are related with skin photoaging. In this study, we assessed the photoaging of facial skin exposed to daily sunlight using in vivo multiphoton laser microscopy to measure AF and SHG.

Methods: The intensities of AF and SHG in the upper dermis of cheek skin of 56 healthy volunteers aged 20-69 years were measured using a commercially available multiphoton laser microscope (DermaInspect(®) ).

Imaging of melanin distribution using multiphoton autofluorescence decay curves.

Background/purpose: Multiphoton fluorescence lifetime imaging (FLIM) is a technique that produces an image based on differences in the decay rate of fluorescence from a sample. Based on this method, the DermaInspect was developed to observe human skin components non-invasively. In this study, we used the DermaInspect to study melanin in skin.

The effect of eye opening and closing on the result of facial wrinkle assessment.

Background/purpose: Since there is no standard protocol that specifies the opening or closing of eyelids in wrinkle assessment, the eyelid position of subjects at the time of assessment varies from study to study. This study aimed to reveal the effect of eye opening and closing on the result of wrinkle assessment. The study also attempted to analyze the age-, site-, and ethnicity-dependent variations in the effect.

Ethnic differences in the structural properties of facial skin.

Background: Conspicuous facial pores are one type of serious aesthetic defects for many women. However, the mechanism(s) that underlie the conspicuousness of facial pores remains unclear. We previously characterized the epidermal architecture around facial pores that correlated with the appearance of those pores.

Development of a novel method to measure the elastic properties of skin including subcutaneous tissue: new age-related parameters and scope of application.

Background/purpose: We have developed a new apparatus to measure the elastic properties of skin without contact using an air blown technique.

Methods: Real-time measurements of skin movement induced by air blown on the surface were measured at various times. We investigated age-related changes in the displacement of the skin surface caused by air using various parameters.

Comparison of age-related changes in facial wrinkles and sagging in the skin of Japanese, Chinese and Thai women.

Background: Differences in skin aging features between Asians and Caucasians are commonly known, whereas little is known about such differences in various Asian populations.

Objective: A survey was carried out in Tokyo, Shanghai and Bangkok to identify specific features of skin aging in each population and to evaluate whether our conventional photo scale is an appropriate tool for this type of comparative study.

Methods: Eighty-seven women residing in Tokyo, 100 women residing in Shanghai, and 90 women residing in Bangkok were examined by a specialist.