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Dziegielewski J Baulch JE Goetz W Coleman MC Spitz DR Murley JS Grdina DJ Morgan WF 《Free radical biology & medicine》2008,45(12):1674-1681
Compounds that can protect cells from the effects of radiation are important for clinical use, in the event of an accidental or terrorist-generated radiation event, and for astronauts traveling in space. One of the major concerns regarding the use of radio-protective agents is that they may protect cells initially, but predispose surviving cells to increased genomic instability later. In this study we used WR-1065, the active metabolite of amifostine, to determine how protection from direct effects of high- and low-LET radiation exposure influences genomic stability. When added 30 min before irradiation and in high concentrations, WR-1065 protected cells from immediate radiation-induced effects as well as from delayed genomic instability. Lower, nontoxic concentrations of WR-1065 did not protect cells from death; however, it was effective in significantly decreasing delayed genomic instability in the progeny of irradiated cells. The observed increase in manganese superoxide dismutase protein levels and activity may provide an explanation for this effect. These results confirm that WR-1065 is protective against both low- and high-LET radiation-induced genomic instability in surviving cells. 相似文献
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Ornella Fantappiè Maura Lodovici Paola Fabrizio Serena Marchetti Valentina Fabbroni Michela Solazzo 《Free radical research》2013,47(7):751-759
Expression of multiple drug resistant (MDR) phenotype and over-expression of P-glycoprotein (P-gp) in the human hepatocellular carcinoma (HCC) cell clone P1(0.5), derived from the PLC/PRF/5 cell line (P5), are associated with strong resistance to oxidative stress and a significant (?p<0.01) increase in intracellular vitamin E content as compared with the parental cell line. This study evaluates the role of vitamin E in conferring resistance to drugs and oxidative stress in P1(0.5) cells. Parental drug-sensitive cells, P5, were incubated in α-tocopherol succinate (α-TS, 5?μM for 24?h) enriched medium to increase intracellular vitamin E content to levels comparable to those observed in P1(0.5) cells at basal conditions. Susceptibility to lipid peroxidation and oxidative DNA damage were assessed by measuring the concentration of thiobarbituric-reactive substances (TBARS) and 8-hydroxy-2′-deoxyguanosine (8-OHdG) at basal and after experimental conditions. Cell capacity to form colonies and resistance to doxorubicin were also studied. P5 cells, treated with α-TS, became resistant to ADP-Fe3+ and to ionizing radiation-induced lipid peroxidation as P1(0.5) cells. Exposure to ADP-Fe3+ or ionizing radiation increased TBARS and the 8-OHdG content in the P5 cells, while vitamin E enrichment abolished these effects. Irradiation doses at 5?cGy increased TBARS and 8-OHdG. They also inhibited cell capacity to form colonies in the untreated P5 cells. Incubation with α-TS fully reverted this effect and significantly (p<0.01) reduced the inhibitory effect of cell proliferation induced by irradiation doses at >500?cGy. Resistance to doxorubicin was not affected by α-TS. These observations demonstrate the role of vitamin E in conferring protection from lipid peroxidation, ionizing radiation and oxidative DNA damage on the human HCC cell line. They also rule out any role of P-gp over-expression as being responsible for these observations in cells with MDR phenotype expression. 相似文献
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《Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB)》2016,32(12):1495-1501
Performance comparison of selected photodiodes for usage as radiation detectors for radio-protection is presented. In this study, based on the criteria of minimum sensitive area of 5 mm2, minimum half angle 60° and low cost, four commercial photodiodes are selected for evaluation: SFH205, SFH206, BPW34, and BPX90F. Photodiodes are low cost, small volume and lightweight detectors. As an electronic transducer, photodiode detector is an attractive approach for the development of low power portable electronic dosimeter for direct-reading real-time radiation dose measurement. The devices have been studied with respect to sensitivity (efficiency) in X-rays and gamma rays detection, repeatability and linearity in air kerma. 相似文献
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