We investigated the effects of single and combined exposures to two ubiquitous environmental carcinogens, polycyclic aromatic hydrocarbons and UVA radiation, in Big Blue mouse embryonic fibroblasts. We quantified the cytotoxicity, DNA adduct formation, and induction of mutations in the cII transgene in cells treated with a single agent or combinations of agents in both direct and reverse order....

In Eastern cultures, such as India, it is traditionally recommended that women but not men cover their heads while working in the scorching sun. The purpose of this pilot study was to determine whether there was any scientific basis for this cultural tradition. We examined the differential cytotoxic effects of ultraviolet A light (UVA) on an established T cell line treated with female and male ...

background: different investigation showed that 5-methoxypsoralen and 8- methoxypsoralen reduce birth rates in the rats. objective: in this study we worked out the effect of methoxsalen together with ultraviolent a (uva) radiation on mature balb/c mice spermatogenesis. materials and methods: the ld50 standard was determined 160 mg/kg and the uva dose which causes erythema was calculated 0.046 j...

Photochemotherapy-in which a photosensitizing drug is combined with ultraviolet or visible radiation-has proven therapeutic effectiveness. Existing approaches have drawbacks, however, and there is a clinical need to develop alternatives offering improved target cell selectivity. DNA substitution by 4-thiothymidine (S(4)TdR) sensitizes cells to killing by ultraviolet A (UVA) radiation. Here, we ...

The mechanisms of the toxic eŠects of UVA (320–400 nm) irradiation remain unclear. The actions of monochromatic longer wavelength UVA, in particular, have been di‹cult to analyze because of a lack of a powerful light source; however, a UVA laser that can be used for biological studies was recently developed. In the current studies, we examined the eŠects of 364-nm irradiation on yeast cells usi...

This paper provides an overview of the characteristics of a phenothiazine-mylar dosimeter which can be used as an effective solar UVA exposure assessment tool. This dosimeter is sensitive to UVA wavelengths (315-400 nm); its performance has been characterized in a series of tests such as (a) UVA exposure response (dose-response), (b) temperature stability of the response, (c) impact of long ter...

A personal UV dosimeter that can quantitatively assess high exposure solar UVA exposures has been developed. The chemical polyphenylene oxide has been previously reported on its ability to measure high UVB exposures. This current research has found that polyphenylene oxide, cast in thin film form, is responsive to both the UVA and UVB parts of the solar spectrum. Further to this, the UVB wavele...

The effect of 8-methoxypsoralen-UVA therapy on the catalysis of histidine to trans-urocanic acid by histidine ammonia lyase (HAL, EC 4.3.1.3) was examined using an enzymatic assay from Sigma-Aldrich where the growth of the trans-urocanic acid peak at 277 nm was monitored. A Rayonet Photochemical Mini Reactor (Model RMR-600) equipped with eight, 3500 Å light sources and a custom UVA filter (Mode...

UVA (320-400 nm) and UVB (290-320 nm) are the major components of solar UV irradiation, which is associated with various pathological conditions. UVB causes direct damage to DNA of epidermal cells and is mainly responsible for erythema, immunosuppression, photoaging, and skin cancer. UVA has oxidizing properties that can cause damage or enhance UVB damaging effects on skin. On the other hand, U...

RATIONALE Human skin contains photolabile nitric oxide derivates like nitrite and S-nitroso thiols, which after UVA irradiation, decompose and lead to the formation of vasoactive NO. OBJECTIVE Here, we investigated whether whole body UVA irradiation influences the blood pressure of healthy volunteers because of cutaneous nonenzymatic NO formation. METHODS AND RESULTS As detected by chemolum...