2-Mercaptonicotinoyl glycine prevents UV-induced skin darkening and delayed tanning in healthy subjects: A randomized controlled clinical study.

BACKGROUND: Chronic nonextreme sun exposure induces two mechanisms of skin pigmentation, causing immediate darkening and delayed tanning. A new molecule, 2-mercaptonicotinoyl glycine (2-MNG), has been shown in vitro to inhibit both immediate darkening and new melanin synthesis via covalent conjugation of the thiol group of 2-MNG to melanin precursors. OBJECTIVE: To evaluate 2-MNG in preventing both mechanisms in vivo. METHODS: In a randomized, intra-individual and controlled study, 33 subjects with melanin-rich skin were exposed to UV daylight on designated areas on the back and treated with a cosmetic formula containing 0.5% or 1% 2-MNG alone or 0.5% 2-MNG in association with lipohydroxy acid (LHA, 0.3%) plus Mexoryl-SX (MSX, 1.5%). The respective vehicles were used as controls and 4-n-butyl-resorcinol (4-n-BR, 2.5%) as a positive reference. RESULTS: 2-MNG alone significantly reduced immediate darkening and inhibited new melanin production when compared with vehicle, with higher performance at 1% than at 0.5%. 2-MNG at 0.5% in association with LHA and MSX showed significantly higher performance than 2-MNG 0.5% alone. 2-MNG at 0.5% and 1% showed significantly better performance than 4-n-BR. CONCLUSIONS: 2-MNG inhibited both UV-induced skin pigmentation mechanisms in vivo. The association of 2-MNG with LHA plus MSX showed the highest efficacy on melanin-rich skin with pigmentation induced by UV exposure.

A severe chronic outdoor urban pollution alters some facial aging signs in Chinese women. A tale of two cities.

BACKGROUND: The impact of a chronic outdoor urban pollution on skin aging-related facial signs is a poorly referenced topic. OBJECTIVE: To assess, through visual grading and referential photographic atlas, possible differences in some facial signs between Chinese women, of comparable ages, living in two close cities very differently exposed to urban pollution. METHODS: The faces of two cohorts of 204 Chinese women (2 × 102) of same age-groups (25-45 years), living in Baoding (a highly polluted city) and Dalian (a less polluted city), for at least 15 years, have been analyzed. Standardized facial photographs (full face and lateral views) were taken and examined, focusing on 26 signs that belong to 3 different clusters (wrinkles and skin texture, pigmentation disorders, and skin pores/skin redness). The severity of each facial sign was graded by 15 trained experts with the help of an Asian skin referential photographic Atlas that illustrates various scales of clinical severity (0-5, 0-8…). In addition, a naïve panel of 80 Chinese non-expert women was asked, while viewing all photographs, to answer to 4 questions regarding skin radiance, dullness, healthy appearance, and perceived age. RESULTS: The increased severity of almost all facial signs was mostly observed in the older group (40-45 years) living in Baoding. In particular, the clinical severity of eight facial signs (five related to skin structure and three related to pigmentation) was found strongly and significantly enhanced by a regular exposure to a severe chronic urban pollution. The naïve panel judged the facial appearance of women from Baoding less radiant, duller, less healthy, and found them older than their Dalian counterparts. The monthly-recorded weather conditions (UV radiance, temperature, wind, precipitations) of the two cities (of same latitude) show that these only differ by their very different Air Quality Indexes (AQI). The daily life conditions of all women (UV exposure, use of cosmetic facial products, intake of sweet or spicy food…) were found similar in all age-groups. CONCLUSION: As compared to a moderately polluted region, a severe chronic outdoor urban pollution favors the aggravation of some facial signs in Chinese women. In short, a highly polluted environment can be viewed as an additional accelerating factor of the skin aging process, when compared to a moderately polluted area.

Frequency of traumatic lesions alleged by victims of assault during police custody.

A retrospective study was undertaken to determine the frequency of traumatic lesions found in individuals alleging police brutality during official custody in the département of Hauts-de-Seine, located in the west suburbs of Paris. All medical certificates relating to the examination of 11,653 individuals detained during the year 2004 were analysed. From this population, there were 119 cases where victimized individuals alleged police assault and 245 revealed aggressive police manhandling, as indicated by traces of tight handcuffs. Among the individuals alleging police violence, most of them showed recent traumatic lesions (n=91). The majority of lesions were superficial contusions frequently located in the cervico-cephalic area. All traumatic lesions were compatible with the allegations of police assault. Neurological complications secondary to the application of handcuffs were encountered in less than 2% of the cases. Although no death was recorded in police custody during the period of the study, approximately 5% of the population that had encountered some form of police violence was found to require emergency hospitalization.