Abstract：
:The nitroxide Tempol, a stable free radical, has recently been shown to protect mammalian cells against several forms of oxidative stress including radiation-induced cytotoxicity. To extend this observation, six additional water-soluble nitroxides with different structural features were evaluated for potential radioprotective properties using Chinese hamster V79 cells and clonogenic assays. Nitroxides (10 mM) were added 10 min prior to radiation exposure and full radiation dose-response curves were determined. In addition to Tempol, five of the six nitroxides afforded in vitro radioprotection. The best protectors were found to be the positively charged nitroxides, Tempamine and 3-aminomethyl-PROXYL, with protection factors of 2.3 and 2.4, respectively, compared with Tempol, which had a protection factor of 1.3. 3-Carboxy-PROXYL, a negatively charged nitroxide, provided minimal protection. DNA binding characteristics as studied by nonequilibrium dialysis of DNA with each of the nitroxides demonstrated that Tempamine and 3-amino-methyl-PROXYL bound more strongly to DNA than did Tempol. Since DNA is assumed to be the target of radiation-induced cytotoxicity, differences in protection may be explained by variabilities in affinity of the protector for the target. This study establishes nitroxides as a general class of new nonthiol radioprotectors and suggests other parameters that may be exploited to find even better nitroxide-induced radioprotection.
journal_name
Radiat Resjournal_title
Radiation researchauthors
Hahn SM,Wilson L,Krishna CM,Liebmann J,DeGraff W,Gamson J,Samuni A,Venzon D,Mitchell JBsubject
Has Abstractpub_date
1992-10-01 00:00:00pages
87-93issue
1eissn
0033-7587issn
1938-5404journal_volume
132pub_type
杂志文章abstract：:Many studies have shown the importance of altered cellular proto-oncogene expression in contributing to changes in cell survival, cell transformation, and cell cycle progression. In these experiments we examined the effects of total-body exposure of BCF1 mice to gamma rays (3 Gy) in modulating expression of cellular o...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1992-06-01 00:00:00
abstract：:Aqueous solutions of calf thymus deoxyribonucleic acid (DNA) were exposed to hydrogen peroxide in the presence of air. Base products formed in DNA were identified and quantitated following acid hydrolysis and trimethylsilylation using gas chromatography-mass spectrometry. The yields of these products were dependent up...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1990-03-01 00:00:00
abstract：:Angiogenesis defines the many steps involved in the growth and migration of endothelial cell-derived blood vessels. This process is necessary for the growth and metastasis of tumors, and considerable effort is being expended to find inhibitors of tumor angiogenesis. This usually involves screening of potential anti-an...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2001)155[0171:rdaion]2.0.co;2
更新日期：2001-01-01 00:00:00
abstract：:Fluorescence in situ hybridization procedures were used to examine the influence of chromosome locus on the frequency and type of chromosome aberrations induced by 60Co gamma rays in the human lymphoblastoid cell line TK6. Aberrations involving the X chromosome were compared to those involving the similarly sized auto...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1994-03-01 00:00:00
abstract：:To ensure the high-fidelity transmission by reproductive cells of genetic information from generation to generation, cells have evolved surveillance systems to eliminate genomic lesions by inducing cell suicide and/or DNA repair. In this report, gamma-ray-induced cell death was investigated using the medaka fish, Oryz...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2002)157[0386:acsisf]2.0.co;2
更新日期：2002-04-01 00:00:00
abstract：:The lineal energy distribution and several other dosimetric parameters were measured for the neutrons emitted from a replica of the Hiroshima bomb to determine their usefulness in biological experiments designed to estimate the effectiveness of actual Hiroshima neutrons. The "Little-Boy" replica (LBR) was constructed ...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1991-11-01 00:00:00
abstract：:To determine whether exposure to radiofrequency (RF) radiation can induce DNA damage or apoptosis, Molt-4 T lymphoblastoid cells were exposed with RF fields at frequencies and modulations of the type used by wireless communication devices. Four types of frequency/modulation forms were studied: 847.74 MHz code-division...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/rr3127
更新日期：2004-02-01 00:00:00
abstract：:This study investigated whether the clonogenic ability of tumor cells to establish subcutaneous tumors and the tumor-associated macrophage (TAM) content correlate with the development and extent of the tumor bed effect (TBE). Ten tumors, five sarcomas and five carcinomas, syngeneic to C3Hf/Kam mice were used. Tumors w...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1990-08-01 00:00:00
abstract：:The mechanisms underlying the hyper-radiosensitivity of AT cells were investigated by analyzing chromosome aberrations in the G(2) and M phases of the cell cycle using a combination of chemically induced premature chromosome condensation (PCC) and fluorescence in situ hybridization (FISH) with chromosome painting prob...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2003)159[0597:rcaiat]2.0.co;2
更新日期：2003-05-01 00:00:00
abstract：:We have examined the role of natural killer (NK) cells in situ in the recovery of marrow hematopoiesis in B6D2F1 mice receiving various doses of total-body irradiation (TBI) as a well-characterized model for treatment-induced myelosuppression. Applying an in situ cytotoxic approach for ablating NK 1.1 cells, we have d...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1990-05-01 00:00:00
abstract：:The survival of synchronous G1 or asynchronous Chinese hamster ovary cells in vitro to heat treatment may depend on the cellular population density at the time of heating and/or as the cells are cultured after heating. The addition of lethally irradiated feeder cells may increase survival at 10(-3) by as much as 10- t...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1984-01-01 00:00:00
abstract：:Some recent epidemiological studies have shown a positive association between cancer incidence and exposure to electromagnetic (EM) fields. Evidence from in vitro studies indicates that this effect could be due to synergistic interaction between EM fields and tumor promoters. However, no dose-response data related dir...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1991-04-01 00:00:00
abstract：:A method was used to detect chromosome inversions as apparent or false sister chromatid exchanges (SCEs) in the first mitosis after gamma irradiation of human G0 cells. Dose-response relationships for small inversions have not been measured and reported previously, but it has been assumed that these are induced with a...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1995-08-01 00:00:00
abstract：:The presence of low levels of oxygen may have profound effects on the cytotoxic activity of radiation, radiosensitizers, and bioreductive alkylating agents. As others have shown, low oxygen tensions may significantly alter rates of cellular and chemical oxygen consumption. When experiments are performed at very low ox...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1986-10-01 00:00:00
abstract：:Determinations of the LET distribution, phi(L), of charged particles within a spacecraft in low-Earth orbit have been made. One method used a cylindrical tissue-equivalent proportional counter (TEPC), with the assumption that for each measured event, lineal energy, y, is equal to LET and thus phi(L) = phi(y). The othe...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2001)156[0310:coldmi]2.0.co;2
更新日期：2001-09-01 00:00:00
abstract：:The molecular structure of mutants induced in human lymphoblast cells by 500 cGy X rays in the presence of the radioprotector cysteamine (25 mM) has been compared with that induced by an equally mutagenic treatment of 150 cGy X rays alone. Sets of mutants at the hypoxanthine-guanine phosphoribosyl transferase locus we...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1989-05-01 00:00:00
abstract：:These studies were carried out to examine the capacity of alpha-difluoromethylornithine (DFMO) to modulate cell proliferation and apoptosis in cells of squamous cell carcinomas (SCCs) of the head and neck. Exposure of cells to DFMO (5 mM for 48 h) depleted intracellular putrescine and spermidine levels (greater than 5...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1999-12-01 00:00:00
abstract：:The effects of bromodeoxyuridine (BrdUrd) substitution for thymidine on gamma-ray-induced strand breakage were determined in single- and double-stranded oligonucleotides and double-stranded oligonucleotides containing a mismatched bubble region. BrdUrd does not sensitize complementary double-stranded DNA to gamma-ray-...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/rr3267
更新日期：2004-12-01 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：:We have monitored the end points of cellular survival, micronucleus formation and neoplastic transformation frequency to assess adaptation to ionizing radiation in the C3H 10T1/2 mouse embryo cell system. Plateau-phase cells were pre-exposed to an adapting dose of 0.1 to 1.5 Gy low-dose-rate gamma radiation 3.5 h prio...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1994-04-01 00:00:00
abstract：:We have investigated how radiation quality affects the induction of chromosomal aberrations in human cells. Human lymphocytes were irradiated in vitro with various energies of accelerated high charge and energy (HZE) particles including oxygen, neon, silicon, titanium and iron. Chromosome damage was assessed using thr...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR3291.1
更新日期：2013-07-01 00:00:00
abstract：:Exposure of humans and rodents to radiofrequency (RF) cell phone fields has been reported to alter a number of stress- related parameters. To study this potential relationship in more detail, tube-restrained immobilized Fischer 344 rats were exposed in the near field in a dose-dependent manner to pulse-modulated (11 p...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2001)155[0584:eoiace]2.0.co;2
更新日期：2001-04-01 00:00:00
abstract：:The Radiological Research Accelerator Facility (RARAF) is in its 50th year of operation. It was commissioned on April 1, 1967 as a collaboration between the Radiological Research Laboratory (RRL) of Columbia University, and members of the Medical Research Center of Brookhaven National Laboratory (BNL). It was initiall...
journal_title：Radiation research
pub_type： 历史文章,杂志文章
doi：10.1667/RR002CC.1
更新日期：2017-04-01 00:00:00
abstract：:Neither cell division nor growth of Saccharomyces cerevisiae were stimulated by the ultraviolet luminescence produced by adjacent exponential phase cultures of the yeast. The study included experiments in which the inocula (density = 5 X 10(7) cells cm-3) were irradiated and in which lag phase cultures (densities = 1 ...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1985-05-01 00:00:00
abstract：:This is the 14th report in a series of periodic general reports on mortality in the Life Span Study (LSS) cohort of atomic bomb survivors followed by the Radiation Effects Research Foundation to investigate the late health effects of the radiation from the atomic bombs. During the period 1950-2003, 58% of the 86,611 L...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/rr2629.1
更新日期：2012-03-01 00:00:00
abstract：:Little computational or experimental information is available on site-specific hydroxyl attack probabilities to DNA. In this study, an atomistic stochastic model of OH radical reactions with DNA was developed to compute relative OH attack probabilities at individual deoxyribose hydrogen atoms. A model of the self-comp...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2002)157[0038:ssoatt]2.0.co;2
更新日期：2002-01-01 00:00:00
abstract：:We report here on a qualitative and quantitative comparison of four kinetic photon cell survival models. The commonly used linear-quadratic model extended by a dose protraction factor, the lethal potentially lethal model, the repair misrepair model and the recently reported Giant LOop Binary LEsion (GLOBLE) model are ...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR13862.1
更新日期：2015-11-01 00:00:00
abstract：:Clustered DNA damage is considered an important factor in determining the biological consequences of ionizing radiation. In this study, we successfully estimated the localization of abasic sites (APs) in DNA exposed to ionizing radiation using fluorescence resonance energy transfer (FRET) without any involvement of re...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR13780.1
更新日期：2015-01-01 00:00:00
abstract：:In this article, we describe recent methodological enhancements and findings from the dose reconstruction component of a study of health risks among U.S. radiologic technologists. An earlier version of the dosimetry published in 2006 used physical and statistical models, literature-reported exposure measurements for t...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR13542.1
更新日期：2014-11-01 00:00:00
abstract：:Soil microorganisms in general and biocontrol agents in particular are very sensitive to UV light. The packaging of biocontrol microorganisms into cellular solids has been developed as a means of reducing loss caused by exposure to environmental UV radiation. The bacterial and fungal biocontrol agents Pantoea agglomer...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/rr3027
更新日期：2003-08-01 00:00:00
