The fluorescence spectrum of the homopolymeric double helix poly(dG) x poly(dC) is dominated by emission decaying on the nanosecond time-scale, as previously reported for the alternating homologue poly(dGdC) x poly(dGdC). Thus, energy trapping over long periods of time is a common feature of GC duplexes which contrast with AT duplexes. The impact of such behaviour on DNA photodamage needs to be...

BACKGROUND Intense pulse light (IPL) treatment currently represents one of the most popular non-ablative photodamage skin treatments. Recent anecdotal evidence suggests that aminolevulonic acid (ALA) photodynamic therapy using IPL as a light source is superior to IPL alone for photorejuvenation. METHODS Seven adult subjects (six women, one man) with minimal photodamage were treated with full ...

Potassium leakage is one of the first events that appear after photosensitization of red blood cells. This event may subsequently lead to colloid osmotic hemolysis. The aim of our study was to determine which photodynamically induced damage is responsible for increased membrane cation permeability. This was done by studying the effect of dimethylmethylene blue (DMMB)-mediated photodynamic treat...

Changes in actual efficiency of PS II photochemistry, non-photochemical quenching (NPQ), content of xanthophylls and kinetics of de-epoxidation were studied in ABA-fed and non-ABA-fed leaves of rice and cabbage under NaCl stress. Salt stress induced more progressive decrease in actual efficiency of PS II photochemistry (ФPS II), higher reduction state of PS II, and a small significant increase ...

Ultraviolet (UV) radiation is a carcinogen that also compromises skin appearance and function. Since the UV action spectra for DNA damage, skin cancer, and vitamin D photosynthesis are identical, and vitamin D is readily available from oral supplements, why has sun protection become controversial? First, the media and, apparently, some researchers are hungry for a new message. They have also dr...

BACKGROUND Fine lines and rhytides are clinically evident signs of photodamage. Traditionally, ablative and nonablative lasers have been used for nonsurgical facial rejuvenation, but their side effects and downtime have limited their use. OBJECTIVE Radiofrequency (RF) is novel nonablative technology originally used to target photodamage. It differs from lasers in that it uses an electric curr...

Ultraviolet (UV) radiation is a proven carcinogen, responsible for more than half of all human malignancies. It also compromises skin appearance and function. Since the UV action spectra for DNA damage, skin cancer and Vitamin D(3) (vit D) photosynthesis are identical and vit D is readily available from oral supplements, why has sun protection become controversial, now that some data suggest co...

Lutein and zeaxanthin are xanthophyll carotenoids with potent antioxidant properties protecting the skin from acute photodamage. This study extended the investigation to chronic photodamage and photocarcinogenesis. Mice received either a lutein/zeaxanthin-supplemented diet or a standard nonsupplemented diet. Dorsal skin of female Skh-1 hairless mice was exposed to UVB radiation with a cumulativ...