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UVC Irradiation (uvc + irradiation)
Selected AbstractsEffect of germicidal UVC light on fungi isolated from grapes and raisinsLETTERS IN APPLIED MICROBIOLOGY, Issue 3 2007A. Valero Abstract Aims:, To examine how UVC affects the different genera of fungi commonly isolated from grapes, with the aim of understanding changes in mycobiota during grape ripening and possible applications for preventing grape decay during storage. Methods and Results:, Spores of Aspergillus carbonarius, Aspergillus niger, Cladosporium herbarum, Penicillium janthinellum and Alternaria alternata (between 100,250 spores/plate agar) were UVC irradiated for 0 (control), 10, 20, 30, 60, 300 and 600 s. Plates were incubated at 25°C and colonies were counted daily up to 7 days. Alternaria alternata and Aspergillus carbonarius were the most resistant fungi. Conidial germination in these species was reduced by approx. 25% after 10 s of exposure, compared with greater than 70% reduction for the remaining species tested. Penicillium janthinellum spores were the most susceptible at this wavelength. UVC exposures of 300 s prevented growth of all isolates studied, except for Alternaria alternata. Conclusions:, UVC irradiation plays a major role in selecting for particular fungi that dominate the mycobiota of drying grapes. Significance and Impact of the Study:, The UVC irradiation of harvested grapes could prevent germination of contaminant fungi during storage or further dehydration. [source] Differential Signaling Circuits in Regulation of Ultraviolet C Light-induced Early- and Late-phase Activation of NF-,BPHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 5 2010Shiyong Wu Ultraviolet C light (UVC) induces nuclear factor-kappa B (NF-,B) activation via a complex network. In the early phase (4,12 h) of irradiation, NF-,B activation is accompanied with I,B, reduction via a translation inhibition pathway. In the late phase of UVC-induced NF-,B activation (16,24 h), the I,B, depletion is a combined result of regulation at both transcriptional and translational levels. However, the NF-,B activation appears to be independent of the level of I,B,. In this review, we will discuss the multiple signaling circuits that regulate NF-,B activation during the early and late phases of UVC irradiation. [source] Differential Activation of ERK 1/2 and JNK in Normal Human Fibroblast-like Cells in Response to UVC Radiation Under Different Oxygen Tensions ,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 3 2000Naoki Matsuda ABSTRACT The mechanisms by which mitogen-activated protein kinases (MAPK) respond to the input of UV-induced signal transduction pathways and the resulting biological functions are not well understood. We investigated whether the level of oxygen tension of culture was responsible for the differential activation of MAPK and different cellular outcomes in UVC-irradiated cells. The intracellular oxidative level of normal human fibroblast-like cells in a normal atmosphere (normoxic, 20% O2) was increased within 30 min after UVC irradiation. When cells were cultured at lower oxygen tension in the presence of an antioxidant N -acetyl- l -cysteine (NAC) or under physiologically hypoxic (5% O2) conditions, the elevation of the oxidative level by UV-irradiation was significantly reduced. Among MAPK, extracellular-signal related kinase (ERK) 1/2 was activated by UV regardless of the oxidative level, while c-Jun N-terminal kinase (JNK) activation was inhibited in NAC-treated and in hypoxic cultures. In addition, in cultures at lower oxygen tension, there was less apoptosis and cell survival was enhanced. These results suggest that UV-induced oxidative stress was responsible for intracellular signaling through the JNK pathway. Furthermore, the balance between ERK1/2 and JNK activities after UV irradiation under different oxygen tensions possibly modified cellular outcome in response to UV. [source] Apoptosis regulators Fau and Bcl-G are down-regulated in prostate cancerTHE PROSTATE, Issue 14 2010Mark R. Pickard Abstract BACKGROUND The molecular control of cell death through apoptosis is compromised in prostate cancer cells, resulting in inappropriate cell survival and resistance to cytotoxic therapy. Reduced expression of the functionally connected apoptosis-regulators and candidate tumor suppressors Fau and Bcl-G has recently been implicated in oncogenesis in other tissues. The present study examines the hypothesis that reduced expression of these genes may be involved in prostate cancer. METHODS Fau and Bcl-G mRNA levels were determined by real time RT-PCR in two independent prostate tissue collections. In experiments in vitro, Fau and Bcl-G levels in prostate cancer cell lines were reduced using RNA interference and the effects on sensitivity to UVC irradiation were determined. RESULTS Fau and Bcl-G mRNA levels were both lower in prostate cancer tissue than in normal prostate and Benign Prostate Hyperplasia. Active down-regulation of Fau and Bcl-G expression in vitro resulted in decreased sensitivity to UVC-induced cytotoxicity. Simultaneous down-regulation of Fau and Bcl-G produced a decrease in sensitivity which was similar to either gene alone. CONCLUSIONS Fau and Bcl-G mRNA levels are both decreased in prostate cancer. In prostate cancer cell lines in vitro such down-regulation results in reduced sensitivity to UVC-induced cytotoxicity, consistent with the putative roles of these genes as candidate prostate tumor suppressors. The absence of an additive effect when Fau and Bcl-G were down-regulated simultaneously is consistent with the two genes acting in the same apoptosis pathway, for example, with the pro-apoptotic effects of Fau being mediated through modulation of Bcl-G. Prostate 70: 1513,1523, 2010. © 2010 Wiley-Liss, Inc. [source] | ||||||||||