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Light Skin (light + skin)
Selected AbstractsObsession with Light Skin , Shedding some light on use of skin lightening products in IndiaINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 4 2010Shyam B. Verma MBBS No abstract is available for this article. [source] Health disparities in the forensic sexual assault examination related to skin colorJOURNAL OF FORENSIC NURSING, Issue 4 2009FAAN, Marilyn S. Sommers PhD Abstract Little is known about the role of skin color in the forensic sexual assault examination. The purpose of this study was to determine whether anogenital injury prevalence and frequency vary by skin color in women after consensual sexual intercourse. The sample consisted of 120 healthy (63 Black, 57 White) women who underwent a forensic sexual assault examination following consensual sexual intercourse. Experienced sexual assault forensic examiners using visual inspection, colposcopy technique with digital imaging, and toluidine blue application documented the number, type, and location of anogenital injuries. Although 55% of the total sample was observed to have at least one anogenital injury of any type following consensual intercourse, the percentages significantly differed for White (68%) and Black (43%) participants (p= 0.02). When the presence of anogenital injury was analyzed by specific anatomical region, a significant difference between White and Black participants was only evident for the external genitalia (White = 56%, Black = 24%, p= .003), but not for the internal genitalia (White = 28%, Black = 19%, p= .20) or anus (White = 9%, Black = 10%, p= 0.99). A one standard deviation-unit increase in L* values (lightness) was related to a 150% to 250% increase in the odds of external genitalia injury prevalence (p < 0.001). While Black and White participants had a significantly different genital injury prevalence, dark skin color rather than race was a strong predictor for decreased injury prevalence. Sexual assault forensic examiners, therefore, may not be able to detect injury in women with dark skin as readily as women with light skin, leading to health disparities for women with dark skin. [source] Molecular Responses to Stress Induced in Normal Human Caucasian Melanocytes in Culture by Exposure to Simulated Solar UV,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 2 2005Laurent Marrot ABSTRACT Melanocytes play a central role in the response of skin to sunlight exposure. They are directly involved in UV-induced pigmentation as a defense mechanism. However, their alteration can lead to melanoma, a process where the role of sun overexposure is highly probable. The transformation process whereby UV damage may result in melanoma initiation is poorly understood, especially in terms of UV-induced genotoxicity in pigmented cells, where melanin can act either as a sunscreen or as a photosensitizer. The aim of this study was to analyze the behavior of melanocytes from fair skin under irradiation mimicking environmental sunlight in terms of spectral power distribution. To do this, normal human Caucasian melanocytes in culture were exposed to simulated solar UV (SSUV, 300,400 nm). Even at relatively high doses (until 20 min exposure, corresponding to 12 kJ/m2 UV-B and 110 kJ/m2 UV-A), cell death was limited, as shown by cell viability and low occurrence of apoptosis (caspase-3 activation). Moreover, p53 accumulation was three times lower in melanocytes than in unpigmented cells such as fibroblasts after SSUV exposure. However, an important fraction of melanocyte population was arrested in G2-M phase, and this correlated well with a high induction level of the gene GADD45, 4 h after exposure. Among the genes involved in DNA repair, gene XPC was the most inducible because its expression increased more than two-fold 15 h after a 20 min exposure, whereas expression of P48 was only slightly increased. In addition, an early induction of Heme Oxygenase 1 (HO1) gene, a typical response to oxidative stress, was also observed for the first time in melanocytes. Interestingly, this induction remained significant when melanocytes were exposed to UV-A radiation only (320,400 nm), and stimulation of melanogenesis before irradiation further increased HO1 induction. These results were obtained with normal human cells after exposure to SSUV radiation, which mimicked natural sunlight. They provide new data related to gene expression and suggest that melanin in light skin could contribute to sunlight-induced genotoxicity and maybe to melanocyte transformation. [source] The patterns of melanosome distribution in keratinocytes of human skin as one determining factor of skin colourBRITISH JOURNAL OF DERMATOLOGY, Issue 3 2003H.-Y. Thong Summary Background One determining factor of skin colour is the distribution pattern of melanosomes within keratinocytes. Melanosomes in keratinocytes of light skin as in Caucasians are distributed as membrane-bound clusters, whereas the melanosomes in keratinocytes of dark skin as in African/American individuals tend to be larger and distributed individually. It has been shown that melanin content, melanin composition and the size of melanosomes in the human epidermis vary considerably with both ethnicity and chronic sun exposure. Objectives To assess quantitatively the distribution pattern of melanosomes that have been transferred to keratinocytes in the photoprotected (volar forearm) skin from normal Asian individuals and to compare these data with those from light-skinned Caucasian and dark-skinned African/American individuals. Methods Electron microscopy was used. Results We have demonstrated that melanosomes within keratinocytes of Asian skin are distributed as a combination of individual and clustered melanosomes with a proportion of 62·6% vs. 37·4%, respectively. This contrasts with dark and light skin keratinocytes where melanosomes are predominantly individual (88·9%) and clustered (84·5%), respectively. Analysis of mean ± SD melanosome size also revealed a progressive variation in size with ethnicity, melanosomes in dark skin being the largest (1·44 ± 0·67 ,m2 × 10,2) followed in turn by those in Asian skin (1·36 ± 0·15 ,m2 × 10,2) and Caucasian skin (0·94 ± 0·48 ,m2 × 10,2). In addition, it was shown that the melanosomes that are individually distributed tend to have a larger size than the clustered melanosomes. Conclusions The present data indicate that there may be a size gradient of melanosomes encompassing the global complexion coloration and that the melanosome distribution in keratinocytes of Asian skin is intermediate between that in light Caucasian and dark African/American skin. [source] | ||||||||||