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DNA damage induced by UV radiation is a critical event in skin photocarcinogenesis. However, the role of racial/ethnic origin in determining individual UV sensitivity remains unclear. In this study, we examined the relationships between melanin content and DNA damage induced by UV exposure in situ in normal human skin of different racial/ethnic groups,(More)
Objective in situ measurements of skin pigmentation are needed for accurate documentation of pigmentation disorders, in studies of constitutive and induced skin pigmentation, for testing of the efficacy of pro-pigmentation or de-pigmentation agents, etc. Non-invasive instrumental measurements of skin pigmentation have been used for many decades. All are(More)
The risk of squamous cell carcinoma (SCC) from ultraviolet radiation (UV) emitted by unfiltered fluorescent lamps was assessed. The assessment employed a mathematical power model based on human epidemiological data, which relates the SCC incidence in the United States white population to ambient solar UV. The annual numbers of new SCC on anatomical sites(More)
BACKGROUND Various physical, chemical and biological insults, including exposure to ultraviolet (UV) radiation, cause erythema and change in pigmentation in human skin. These reactions provide an important measure of the cutaneous response to the insult. OBJECTIVES To present a new implementation of a method for objective in vivo measurement of erythema(More)
Pigmentation of human skin is closely involved in protection against environmental stresses, in particular exposure to ultraviolet (UV) radiation. It is well known that darker skin is significantly more resistant to the damaging effects of UV, such as photocarcinogenesis and photoaging, than is lighter skin. Constitutive skin pigmentation depends on the(More)
Ultraviolet radiation stimulates pigmentation in human skin, but the mechanism(s) whereby this increase in melanin production (commonly known as tanning) occurs is not well understood. Few studies have examined the molecular consequences of UV on human skin of various racial backgrounds in situ. We investigated the effects of UV on human skin of various(More)
The use of unfiltered quartz-halogen lamps exposes human skin to radiation that spans much of the ultraviolet (UV) spectrum. Reports indicate that exposure to quartz-halogen lamps is erythemogenic, mutagenic, and carcinogenic. To compare the carcinogenic potential of quartz-halogen lamps with that of other UV sources, we determined the dose dependence for(More)
High-frequency ultrasound images were used to measure the thickness of the dermis and epidermis of four human subjects. These measurements were performed before and after a single exposure to ultraviolet radiation (UV). Doses ranging from 0.5 to 3 minimal erythema doses (MED) were delivered to the skin of the back of four human subjects, and thickness(More)
Melanin plays an important role in protecting the skin against UV radiation, and melanomas and basal/squamous cell carcinomas occur more frequently in individuals with fair/light skin. We previously reported that levels of melanin correlate inversely with amounts of DNA damage induced by UV in normal human skin of different racial/ethnic groups. We have now(More)
Murine leukemic lymphoblasts L5178Y-R (LY-R) undergo conversion into their L5178Y-S (LY-S) variant as a result of prolonged (5 months to 4 years) cultivation in vitro. LY-R cells are highly tumorigenic in DBA/2 mice; resistant to X-rays [D0 (mean lethal dose [reciprocal of the slope of the linear portion of dose-survival curve] ) = 0.91 grays]; and(More)