urocanic acid/erythema

BACKGROUND cis-Urocanic acid (cis-UCA) is an endogenous immunosuppressive molecule of the epidermis. OBJECTIVE We investigated the effects of topical cis-UCA creams (2·5% and 5%) in acute and subacute mouse models of skin inflammation. METHODS Acute skin irritation was induced by applying dimethyl

Commercial sunscreens may offer some protection from immunosuppression induced by ultraviolet (UV) radiation, but agreement concerning the degree of protection is lacking. Cis-urocanic acid, formed by the photoisomerization of transurocanic acid is considered an important mediator of the cutaneous

The relationship of epidermal urocanic acid concentration and photoisomerization reactivity to human skin cancer was studied. Twelve cutaneous malignant melanoma patients, 10 basal cell carcinoma patients and 22 healthy matched controls were enrolled in the study. A solar simulating ultraviolet

To investigate the relationship between erythemal sensitivity of the skin to UV radiation and epidermal urocanic acid (UCA) concentration, 45 healthy volunteers of anamnestic skin phototypes (ASP) 1-IV were studied. In 16 of the subjects, we analyzed UCA photoisomerization after graded UVB

Solar radiation contains ultraviolet B (280-315 nm) and ultraviolet A (ultraviolet AII, 315-340 nm; ultraviolet AI, 340-400 nm) wavebands. Ultraviolet B is known to suppress certain aspects of cell mediated immunity. Using three ultraviolet lamps (the broad-band ultraviolet B TL-12, the narrow-band

The immunological consequences of exposure to UVA (320-400 nm) radiation are unclear. This study describes the relationship between the generation of epidermal cis-urocanic acid and the ability to respond to a contact-sensitizing agent, in hairless mice exposed to different UV radiation sources,

The effect of a null mutation for the metallothionein (MT)-I and -II isoforms in mice on the immunosuppressive action of ultraviolet B (UVB; 280-320 nm) radiation has been examined. Mice were exposed to a series of increasing daily UVB doses, each dose administered to the dorsum on 3 consecutive

Terrestrial ultraviolet radiation (UVR) exposure, consisting of ultraviolet A (320-40 nm) and B (290-320 nm), results in the photoisomerizion of epidermal trans-urocanic acid (trans-UCA) to cis-urocanic acid (cis-UCA), a potential suppressor of local and systemic immune responses. This study

OBJECTIVE Trans-urocanic acid is isomerized to cis-urocanic acid (C-UCA) by ultraviolet radiation. C-UCA suppresses immunity in vitro and in vivo in animals; its effect on human skin is unknown. We sought to determine whether its topical application to normal skin suppresses induction of immunity to

A series of experimental sunscreen preparations based on a common vehicle, containing increasing concentrations of either octyl-N-dimethyl-p-aminobenzoate (o-PABA) or 2-ethylhexyl-p-methoxycinnamate (2-EHMC) as the ultraviolet B (UVB) absorber, has been tested in the hairless mouse for the ability

Urocanic acid (UCA), present in the stratum corneum, is a major absorber of ultraviolet (UV) radiation and, on UV exposure, is induced to isomerize from the naturally occurring trans-isomer to the cis-isomer. Cis-UCA has been shown to have immunosuppressive properties, while trans-UCA may act as a

Exposure to sunlight can result in a number of harmful effects, including sunburn, erythema, premature aging of the skin, immune suppression and skin cancer. Studies designed to understand the underlying mechanisms often depend upon the use of artificial sources of UV radiation. Unfortunately,

Urocanic acid (UCA), present in the stratum corneum as trans-UCA, absorbs ultraviolet (UV) radiation and isomerizes to cis-UCA. Cis-UCA has been demonstrated to initiate suppression of selected immune responses in several experimental systems. Topical application of UCA-containing products reduces

The photoisomerization characteristics of urocanic acid (UCA) were studied by using both a narrow-band monochromator and 4 broad-band phototherapy devices. The latter included 2 ultraviolet B (UVB) irradiators with different emission spectra, a black-light UVA source and a long-range UVA emitter.

Exposure to ultraviolet (UV) radiation may induce erythema, DNA damage and suppression of immune responses. Melanin pigmentation offers protection against the first two of these effects, but immunosuppression seems to occur irrespective of the subject's pigmentation. Cis-urocanic acid (cis-UCA),