Facial cleansers, which are mainly composed of fatty acid soaps or surfactants, have some potential to damage skin, depending on their usage. To prevent this undesirable effect, several efforts have been made in designing formulations. Selection of surfactants which have less irritant potency is an example. However, there are some cases in which we could not obtain the expected outcome in practical situations. When using a facial cleanser, consumers change it in shape by themselves ; that is, they make lather in their own way. Focusing on that point, we investigated whether the lather makes an impact on the skin condition. Volunteers were employed for a short-term test to use a standard facial cleanser. They were assigned to two groups ; one group was directed to make good lather in advance, while the other to make it poorly. The amount of product per use and the density of lather, expressed as the mass of total fatty acids per unit volume, were measured. Examination of facial skin was conducted at the end of the test. As a result, those who made good lather didn't show any adverse effect. On the other hand, the others who made poor lather showed a few symptoms of redness, scaling, stinging or itchiness. Based on the result, we conclude that it is important to give more explicit information on the point of usage (i. e. the ideal amount of product per use, adding water into lather, and working with a sufficient amount of air) . We also consider that there is more need to enlighten consumers on that point.

View full abstract

Skin roughness is one of the problems most concerning young women. We found many small swellings in the forehead of young women with comedogenic skin from the ages of 20 to 35. Although this roughness was supposed to indicate primary comedo, details have not been examined. We analyzed the morphology and the process of development of roughness. The results showed that skin roughness consisted of small and unnoticeable comedones which were above 100μm high and were colorless. These small swellings were possibly primary comedones named ‘missed comedones’ which were hardly supposed to be recognized as comedones by the persons who had acne vulgaris. We developed a new method of counting swellings in forehead, and the number of swellings periodically changed. Some of these swellings progressed to inflammatory acnes. We found that the persons who showed lots of roughness had a high amount of sebum. From these results we assumed that the excess of sebum and bad condition of the turnover of corneocytes may cause skin roughness and induce many swellings. We have developed effective lotions which contain salicylic acid and tranexamic acid as the active components. Application of these lotions resulted in a decrease in the amount of small swellings and improvement in skin roughness.

View full abstract

Our skin temperature varies considerably according to the external temperature. However, very little is known about the mechanism by which temperature fluctuation directly affects the skin's physiological function. The present study provides a molecular-level explanation for the direct involvement of temperature in human skin barrier function via thermo-sensitive TRPV4 which is activated by warm temperature (>30°C) . We demonstrated that activation of TRPV4 was crucial for barrier formation and recovery, both of which were critical for the prevention of excessive dehydration of human skin keratinocytes. TRPV4 activation by physiological skin temperature (33°C) or 4α-PDD allowed influx of Ca²⁺ from extracellular spaces which promoted small GTPase Rho activation and cell-cell junction development. These changes resulted in augmentation of intercellular barrier integrity in vitro and ex vivo. Furthermore, lagerstroemia speciosa extract induced an increase in cytosolic Ca²⁺ concentrations in HEK293 cells expressing TRPV4 channels and promoted intercellular barrier function in NHEKs. We believe that our new findings will not only open a new direction for dermatological research focusing on temperature, but also lead to development of novel ideas for a new category of skin care products that take into consideration the effects of skin temperature and thermo-sensitive proteins.

View full abstract

Skin is the outermost organ that is always in contact with the outside world, and is necessarily influenced by external factors such as humidity, temperature, insolation and the trendy factors including suntan and internal factors such as itch and pain. Thus women's skin is likely to be diverse. Therefore, in skincare habits, it is important to know the possible external and internal factors and to respond to them in order to keep healthy and beautiful skin. Hence, to elucidate the difference and changing of skin condition depending on external and internal factors, we investigated 20 years of long-term changes in the skin condition of women in all areas of Japan from Hokkaido Prefecture (43°04'N 141°21'E), the northern part of Japan to Okinawa Prefecture (26°13'N 127°41'E), the southern part of Japan, including total of 5893536 subjects. The results showed that apparent age spots, skin tone and wrinkle condition changed their tendency around 2000. These findings are thought to be attributable to the fashion trends in skin tone (skin tanning (Ganguro) boom to whitening boom) and social awareness of UV-induced skin damage in Japan (In 1998, sunbathing was removed from the recommendation section in the maternal and child health handbook in Japan) . In the case of pore appearance, a possible tendency according to the geographical difference was found. There was the relationship between skin sensitivity and volatility in coenocyte arrangement regularity scores throughout the year. The highly sensitive group exhibited less volatility and the less sensitive group exhibit more volatility.

View full abstract

In interpersonal communication, verbal and nonverbal behaviors provide important messages that generate psychological meanings to others. An eye-tracking device was used to examine customers' impression formation, based on the appearance of salespeople in face-to-face, over-the-counter encounters, by focusing on the customers' visual attention. Over-the-counter sales in Japan and other countries were emulated with Japanese and international participants. Results indicated that duration and frequency of customers' eye fixations were highest to the faces of salespersons, regardless of whether salespersons were groomed or not groomed. The duration and frequency of customers' eye fixations were highest to salespersons' faces, when the salespersons were groomed, compared to when they were not groomed, suggesting that eyes and facial expressions are more important than the evaluation of impressions. When salespersons were not groomed, the customers' increasingly gazed at the salespersons' body and salespersons' postures and hand positions were rated high in impression formation. The results indicate that the face is capable of transmitting nonverbal messages that are unaffected by context, whereas the body transmits context-dependent nonverbal messages. It is suggested that optimizing the posture and clothing of cosmetic salespeople could attract customers' eyes to the merchandise, resulting in increased sales.

View full abstract