Polychromatic UV irradiation is a common method of pathogen inactivation in the water treatment industry. To improve its disinfection efficacy, more information on the mechanisms of UV inactivation on microorganisms at wavelengths throughout the germicidal UV spectrum, particularly at below 240 nm, is necessary. This work examined UV inactivation of bacteriophage MS2, a common surrogate for ent...

In the past few years, the cellular effects of ultraviolet (UV) irradiation induced in skin have become increasingly recognized. Indeed, it is now well known that UV irradiation induces structural and cellular changes in all the compartments of skin tissue. The generation of reactive oxygen species (ROS) is the first and immediate consequence of UV exposure and therefore the quantitative determ...

INTRODUCTION Molecular mechanisms that supervise radiation-susceptibility of human cells are one of the important problems in Radiation Protection Science. We previously hypothesized that proteases may play a key role in cellular functions triggered by radiation as well as those in SOS functions of E. coli (1). It has been found that the activity is detectable less than 1 min after irradiation ...

PURPOSE To define the role of molecular interaction between the UV-induced JNK (c-Jun N-terminal kinase) cascade and corneal epithelial cell apoptosis and protection against apoptosis by caffeine. METHODS Rabbit and human corneal epithelial cells were cultured in DMEM/F12 medium containing 10% FBS and 5 microg/mL insulin at 37 degrees C in 5% CO(2). DNA fragmentation and ethidium bromide/acri...

Ultraviolet-B (UV-B) irradiation of antigen presenting cells (APCs) modifies their allogenecity, resulting in inhibition of the proliferative response of T cells in mixed lymphocyte reaction (MLR). Costimulation by the CD28 ligand CD80 (B7/B7-1) and CD86 (B70/B7-2) plays an important role during T-cell proliferation by augmenting synthesis of interleukin-2 (IL-2) and other cytokines. In this st...

Inhibition of photosynthesis and epidermal damage resulting from ultraviolet irradiation were assessed for arctic and alpine plant species. These species were taken from a latitudinal gradient of the arctic-alpine life zone from the Andes to northern Alaska, which spans a steep change in solar UV-B irradiation (280 to 320 nm). Ecotypes and species from the Arctic, where solar UV-B flux is very ...

In our previous study, we found that colcemid, an inhibitor of mitotic spindle, promotes UVC-induced apoptosis in Chinese hamster ovary cells (CHO-K1). A brief treatment of colcemid on cells after UV irradiation could synergistically reduce the cell proliferation. In this study, colcemid was found to hinder the restoration of genomic integrity following UV irradiation based on results of the nu...

Flow cytometry analysis was used to detect the changes of γH2AX protein expression in human peripheral blood lymphocytes. In the dose-effect study, the expression of γH2AX was detected 1 h after irradiation with 60Co γ-rays at doses of 0, 0.5, 1, 2, 4, and 6 Gy. Blood was cultivated for 0, 1, 2, 4, 6, 12, and 24 h after 4 Gy 60Co γ-rays irradiation for the time-effect study. At the same time, t...

BACKGROUND/AIMS Ultraviolet (UV) irradiation of mammalian cells in culture evokes the transcriptional activation of different proto-oncogenes, among them members of the fos/jun family which are known to play an important role in cell proliferation and differentiation. To investigate in vivo UV induced proto-oncogene expression of irradiated ocular cells, the expression of JunB, JunD, and Egr-1 ...

Dihydrorhodamine (DHR) 123 is a fluorophore commonly used for measuring reactive oxygen species (ROS), often after exposing cells to ultraviolet (UV) irradiation or oxidative burst inducers such as Phorbol 12-myristate 13-acetate (PMA). However, the negative effects of UV irradiation on oxidation of DHR123 itself to green fluorescence rhodamine (R) 123 under different experimental conditions (e...