Abstract：
:We measured the production of reactive hydroxyl radical (OH.) by Fe2+ itself or complexed with nucleotide triphosphates or tripolyphosphate (TPP). Coumarin-3-carboxylic acid (3-CCA) reacts with the OH. produced by Fe2+, Fe3+ or Cu2+ plus ascorbate and with various iron complexes. We measured in real time the increased fluorescence of 3-CCA after hydroxylation to 7-hydroxy-coumarin-3-carboxylic acid (7-OHCCA). Phosphate-buffered solutions do not affect the yield of Fe(2+)-linked OH. as do other organic buffer solutions. Our results show that guanosine triphosphate enhances the Fe(2+)-linked production of OH.. We also tested inosine triphosphate, adenosine triphosphate and xanthine triphosphate for their capacity to produce OH. with Fe2+. Inosine triphosphate is the most effective nucleotide in the production of OH.. However, the Fe(2+)-mediated yield of OH. is greater in the presence of TPP compared to the nucleotide triphosphates. Organic buffers as well as the purine and ribose portion of nucleotides compete for OH. and decrease the yield of fluorescent 7-OHCCA. We also decreased the yield of OH. by adding guanosine to the Fe2+/TPP-generating system. Adenosine, ribose and deoxyribose also react with Fe(2+)-generated OH.. The decreased yield of 7-OHCCA occurs because the ribose and purine part of the molecule reacts with OH.. The maximal production of reactive OH., compared to all nucleotides and phosphates tested, occurs with a ratio of 2 TPP/Fe2+ complex. In conclusion, the real-time measurement of the production of fluorescent 7-OHCCA provides a convenient means for measuring chemically generated OH.. The TPP/Fe(2+)-generating mixture, in the presence of 3-CCA, can be used to study the scavenging ability of other competing molecules.
journal_name
Radiat Resjournal_title
Radiation researchauthors
Biaglow JE,Held KD,Manevich Y,Tuttle S,Kachur A,Uckun Fsubject
Has Abstractpub_date
1996-05-01 00:00:00pages
554-62issue
5eissn
0033-7587issn
1938-5404journal_volume
145pub_type
杂志文章,评审abstract：:Intestinal microbiota affect cell responses to ionizing radiation at the molecular level and can be linked to the development of the immune system, controlled cell death or apoptosis. We have developed a microbiota mouse model and report here that high-linear energy transfer (LET) radiation induced the repair of chrom...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR13837.1
更新日期：2015-06-01 00:00:00
abstract：:There has been increased interest in the immune stimulatory properties of ionizing radiation based on several preclinical models and recently completed clinical studies performed in combination with checkpoint inhibitors. This is a paradigm shift in that it considers the role of radiation beyond its direct cytotoxic e...
journal_title：Radiation research
pub_type： 杂志文章,评审
doi：10.1667/RR14941.1
更新日期：2018-03-01 00:00:00
abstract：:Our data (Reddy et al., Radiat. Res. 141, 252-258, 1995) on the kinetics of the repair of potentially lethal damage in log-phase Chinese hamster V79 cells are used to test some predictions which arise from the different assumptions of the repair-misrepair (RMR) (C. A. Tobias, Radiat. Res. 104, S77-S95, 1985), lethal-p...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1997-09-01 00:00:00
abstract：:In the double-strand break (DSB) model, the initial slope (alpha) of the survival curve is determined by the number of DSBs remaining unrepaired at a certain time after irradiation. There are three types of calculations which confirm the validity of this approach. First, the model quite reasonably predicts the low-LET...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1993-02-01 00:00:00
abstract：:Base damage flanking a radiation-induced DNA double-strand break (DSB) may contribute to DSB complexity and affect break repair. However, to date, an isolated radiation-induced DSB has not been assessed for such structures at the molecular level. In this study, an authentic site-specific radiation-induced DSB was prod...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR0628.1
更新日期：2006-11-01 00:00:00
abstract：:In previous studies we determined a gene expression signature in baboons for predicting the severity of hematological acute radiation syndrome. We subsequently validated a set of eight of these genes in leukemia patients undergoing total-body irradiation. In the current study, we addressed the effect of intra-individu...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR15013.1
更新日期：2018-09-01 00:00:00
abstract：:In this study, we investigated the effect of (131)I gelatin microspheres ((131)I-GMSs) on human hepatocellular carcinoma cells (HepG2) in nude mice (Balb/c) and the biodistribution of (131)I-GMSs after intratumoral injection. The treatment group and control group animals received intratumoral injections of 1 mCi (131)...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR13539.1
更新日期：2014-04-01 00:00:00
abstract：:The interaction function gamma(chi), which was introduced in the theory of dual radiation action as the probability that two energy transfers separated by distance chi combine with each other to produce a lesion, was estimated with sparsely ionizing radiation (60Co gamma rays and 40 kV X rays). Gamma(chi) was deduced ...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1987-10-01 00:00:00
abstract：:DNA double-strand breaks (DSBs) are 2.9 times more frequently induced in yeast cells exposed to sparsely ionizing 30-MeV electrons under oxic compared to anoxic conditions. The rejoining of DSBs induced under anoxic conditions was investigated under conditions allowing repair of potentially lethal damage and compared ...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1991-12-01 00:00:00
abstract：:Oncogenic transformation of C3H 10T1/2 cells was determined after exposure to graded doses of 4.3-MeV alpha particles LET = 101 keV/microns. The source of alpha particles was 244Cm and the irradiation was done in an irradiation chamber built for the purpose. Graded doses in the range of 0.2 to 300 cGy were studied wit...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1992-07-01 00:00:00
abstract：:To determine whether different agents that enhance the expression of potentially lethal X-ray damage (PLD) interact with the same or different lesions (or spectrum of lesions), cell killing was measured in three kinds of experiments: (1) When cells were irradiated in G1 phase and treated with caffeine or hydroxyurea a...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1991-11-01 00:00:00
abstract：:Previous studies identified radiation therapy as a key modifier of basal cell carcinoma (BCC) risk in survivors of hematopoietic cell transplantation (HCT). In the present analysis, risk of BCC was analyzed in relation to age at transplant, attained age, race, total-body irradiation (TBI), and radiation fractionation ...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR1469.1
更新日期：2009-02-01 00:00:00
abstract：:To accurately quantify the number of single-strand breaks (SSBs) induced in plasmid DNA molecules after irradiation, a new type of assay methodology has been explored. The new method is based on the TUNEL (terminal deoxynucleotide transferase dUTP nick end-labeling) assay that was adopted for use under ELISA (enzyme-l...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR1684.1
更新日期：2009-11-01 00:00:00
abstract：:Radiation therapy is an essential component of cancer treatment. Currently, tumor control and normal tissue complication probabilities derived from a general patient population guide radiation treatment. Its outcome could be improved if radiation biomarkers could be incorporated into approaches to treatment. A substan...
journal_title：Radiation research
pub_type： 杂志文章,评审
doi：10.1667/RR15553.1
更新日期：2020-03-01 00:00:00
abstract：:The relationship between apoptosis induced by gamma radiation and glutathione in cells of two human cancer cell lines, HeLa from cervix carcinoma and MCF-7 from mammary carcinoma, was examined. MCF-7 cells appeared to be more radioresistant than HeLa cells, and radiation-induced apoptosis, which was monitored by asses...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR0578.1
更新日期：2007-03-01 00:00:00
abstract：:Bcl-X(S) is a pro-apoptosis member of the Bcl2 family that has been shown to induce cell death and enhance chemosensitivity. We have investigated the effect of Bcl-X(S) overexpression on radiation sensitivity. Using a tetracycline-repressible system, we found that removal of tetracycline for 16 h induced Bcl-X(S) and ...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/rr3169
更新日期：2004-05-01 00:00:00
abstract：:A recently developed method for the direct measurement of the restricted dose mean LET (cutoff energy = 500 eV) of an unspecified photon or electron radiation field with the high-pressure ionization chamber has been utilized to investigate the variation of this radiobiologically important parameter outside the primary...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1987-04-01 00:00:00
abstract：:The natural survival, relative to properly chosen controls, of 26 beagle dogs injected once intravenously with an average of 0.58 +/- 0.04 kBq 239Pu/kg, 23 dogs injected with 2.31 +/- 0.43 kBq 226Ra/kg, 13 dogs injected with 1.84 +/- 0.26 kBq 228Ra/kg, 12 dogs injected with 0.56 +/- 0.030 kBq 228Th/kg, and 12 dogs inj...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1991-06-01 00:00:00
abstract：:Changes in the free-cell population of the lungs of two strains of mice (SAS/4 and CBA/H) were studied up to 4 months after inhalation exposure to a sized fraction of 239PuO2 particles (1.5 micron AMAD) to give initial alveolar depositions (IADs) ranging from 17 to 810 Bq. A sample of the free-cell population of the l...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1986-03-01 00:00:00
abstract：:Current therapeutic approaches for treatment of exposure to radiation involve the use of antioxidants, chelating agents, recombinant growth factors and transplantation of stem cells (e.g., hematopoietic stem cell transplantation). However, exposure to high-dose radiation is associated with severe damage to the vascula...
journal_title：Radiation research
pub_type： 杂志文章,评审
doi：10.1667/RR14461.1
更新日期：2016-08-01 00:00:00
abstract：:There is growing scientific, regulatory and public concern over anthropogenic input of radionuclides to the aquatic environment, especially given the issues surrounding existing nuclear waste, future energy demand and past or potential nuclear accidents. A change in the approach to how we protect the environment from ...
journal_title：Radiation research
pub_type： 杂志文章,评审
doi：10.1667/rr2687.1
更新日期：2012-05-01 00:00:00
abstract：:Based on murine survival studies, endogenous hemopoietic spleen colony formation (E-CFU), and recovery of bone marrow and splenic granulocyte-macrophage colony-forming cells (GM-CFC), it was demonstrated that the postirradiation administration of glucan, an immunomodulator and hemopoietic stimulant, enhances the radio...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1989-01-01 00:00:00
abstract：:Through a detailed study of cell cycle progression, protein expression, and kinase activity in gamma-irradiated synchronized cultures of human skin fibroblasts, distinct mechanisms of initiation and maintenance of G2-phase and subsequent G1-phase arrests have been elucidated. Normal and E6-expressing fibroblasts were ...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2003)159[0072:cotmoi]2.0.co;2
更新日期：2003-01-01 00:00:00
abstract：:Caffeine is a model radiosensitizing agent that is thought to work by abrogating the radiation-induced G(2)-phase checkpoint. In this study, we examined the effect that various concentrations of caffeine had on cell cycle checkpoints and apoptosis in cells of a human lung carcinoma cell line and found that a concentra...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2002)157[0166:citigp]2.0.co;2
更新日期：2002-02-01 00:00:00
abstract：:Molecular imaging is an evolving science that is concerned with the development of novel imaging probes and biomarkers that can be used to non-invasively image molecular and cellular processes. This special issue approaches molecular imaging in the context of radiation research, focusing on biomarkers and imaging meth...
journal_title：Radiation research
pub_type：
doi：10.1667/rr2959.1
更新日期：2012-04-01 00:00:00
abstract：:The molecular basis of radiotherapy-related multidrug resistance (MDR) is still unclear. Here we report on a study investigating the effect of fractionated irradiation on expression of the MDR-associated proteins P-glycoprotein (P-gp), multidrug resistance-associated protein (MRP), and lung resistance-related protein ...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR0986.1
更新日期：2008-07-01 00:00:00
abstract：:The reactions of free and DNA-bound 2,2,5,5-tetramethylpyrrolidine-N-oxyl (PROXYL) probes with radicals generated during radiolysis of dilute aqueous solutions of DNA were examined. For the free PROXYL probe in deaerated solution with each of the four nucleotides (dAMP, dCMP, dGMP, and TMP) it was found that the pyrim...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1987-10-01 00:00:00
abstract：:Experimental data from laboratory animals indicate that the same extent of DNA damage or the same mutations in oncogenes and tumor suppressor genes in different hosts result in widely differing cancer development because of numerous polymorphic tumor susceptibility genes. Similarly, recent epidemiological data indicat...
journal_title：Radiation research
pub_type： 杂志文章,评审
doi：10.1667/rr3333.1
更新日期：2005-10-01 00:00:00
abstract：:Cancer mortality in relation to radiation dose was evaluated among 4153 women treated with intrauterine radium (226Ra) capsules for benign gynecologic bleeding disorders between 1925 and 1965. Average follow up was 26.5 years (maximum = 59.9 years). Overall, 2763 deaths were observed versus 2687 expected based on U.S....
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1990-09-01 00:00:00
abstract：:Mutation and killing induced by X radiation and 60CO gamma radiation were studied in six different histidine-requiring auxotrophs of Salmonella typhimurium. Strain TA100, which is sensitive to base-pair substitutions, and strains TA2637 and TA98, which are sensitive to frameshifts, carry the pKM101 plasmid and exhibit...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1984-11-01 00:00:00
