The aim of this study was to investigate corneal enzymatic resistance following epithelium off and on riboflavin/UVA cross-linking (CXL). One hundred and fourteen porcine eyes were divided into four non-irradiated control groups and seven CXL groups. The latter comprised; (i) epithelium-off, 0.1% iso-osmolar riboflavin, 9 mW UVA irradiation for 10 min, (ii) disrupted epithelium, 0.1% hypo-osmol...

background : one way to optimize energy consumption is replacing incandescent lamp with compact fluorescent lamps .these lamps produce ultraviolet radiation due to the nature of light production. this study aimed to evaluate the ultraviolet radiation emitted from compact fluorescent lamps which are widely used in iran. methods : this study carries out on 16 compact fluorescent lamps (four diffe...

Diesel exhaust has been classified as a potential carcinogen and is associated with various health effects. A previous study showed that the doses for manifesting the mutagenetic effects of diesel exhaust could be reduced when coexposed with ultraviolet-A (UVA) in a cellular system. However, the mechanisms underlying synergistic effects remain to be clarified, especially in an in vivo system. I...

PURPOSE To determine the mechanism that leads to the UVA light-dependent loss of glutathione reductase (GR) activity in human lens (HL). METHODS Both the HL water-soluble (WS) fraction and yeast GR were irradiated with UVA light (200 mW/(cm(2). h) for 1 hour at +20 degrees C, and the specific activity (SA) was observed. GR apoenzyme (apo-GR) was prepared from either HL-WS fractions or yeast G...

The single-cell gel/comet assay is an electrophoretic technique used to detect single-strand breaks in DNA. Damage is assessed examining individual cells under an epifluorescent microscope. UV-induced DNA damage consists mostly of the formation of pyrimidine dimers; therefore, most of the damage cannot be detected using a standard comet assay. The enzyme T4 endonuclease V breaks DNA strands at ...

PURPOSE Combined riboflavin/UVA treatment inducing collagen cross-links in the cornea has been shown to increase the biomechanical rigidity of the cornea and has been used successfully in the treatment of progressive keratoconus. The current study was undertaken to investigate the possible cytotoxic effect of combined riboflavin/UVA treatment on corneal keratocytes in vivo. METHODS Thirty-fou...

PURPOSE Laser-assisted in situ keratomileus (LASIK) creates a permanent flap that remains non-attached to the underlying laser-modified stroma. This lack of permanent adhesion is a liability. To immobilize a corneal flap, a protocol using fibrinogen (FIB), riboflavin (RF), and ultraviolet (UVA) light (FIB+RF+UVA) was devised to re-adhere the flap to the stroma. METHODS A model flap was create...

BACKGROUND There are unpredictable inter-individual differences in sensitivity to psoralen-UVA (PUVA) photochemotherapy, used to treat skin diseases including psoriasis. Psoralens are metabolised by cytochrome P450 enzymes (P450), and we hypothesised that variability in cutaneous P450 expression may influence PUVA sensitivity. We previously showed that P450 CYP1B1 was abundantly expressed in hu...