Abstract：
:The intrinsic radiosensitivity of tumor cells is most frequently reported for asynchronous populations, although cell cycle variation in radiosensitivity is known to be significant. Linear-quadratic analyses of survival data for asynchronous human tumor cells show wide variations in the alpha coefficient with smaller variations in the beta coefficient. HT-29 (colon), OVCAR10 (ovary) and A2780 (ovary) tumor cells with alpha coefficients of 0.03, 0.16 and 0.47 Gy(-1), respectively, and square-root of beta coefficients of 0.23-0.27 Gy(-1) for asynchronous populations were amenable to synchronization by mitotic selection. Selection procedures were optimized for each cell line and produced mitotic populations of >90%, approximately 80% and approximately 65% purity for HT-29, OVCAR10 and A2780 cells, respectively. Mitotic cells from each line exhibited similar and maximum radiosensitivities with alpha coefficients of approximately 1.3 Gy(-1) after irradiation with 137Cs gamma rays and after correction for genome multiplicity. Their relative radiosensitivities observed with asynchronous cells were maintained as they progressed through interphase of the cell cycle. All cells in early G1 phase exhibited a marked radioresistance relative to their sensitivity in mitosis, and maximum interphase radiosensitivity was observed near the G1/S-phase boundary. All cells became increasingly radioresistant as they moved through S phase, the effect being most pronounced for OVCAR10 cells and least pronounced for A2780 cells. HT-29 cells remained relatively radioresistant in G2 phase. The different interphase radiosensitivities observed for these cell lines were determined mainly by the single-hit inactivation mechanism. These studies clearly demonstrate the dominant role of single-hit inactivation in determining the intrinsic radiosensitivity of human tumor cells to 137Cs gamma rays, especially at doses of 2 Gy and less.
journal_name
Radiat Resjournal_title
Radiation researchauthors
Biade S,Stobbe CC,Chapman JDsubject
Has Abstractpub_date
1997-04-01 00:00:00pages
416-21issue
4eissn
0033-7587issn
1938-5404journal_volume
147pub_type
杂志文章abstract：:The correlation between the protein content of nuclei and heat-induced cell killing was determined for HeLa cells with various levels of thermotolerance. Thermotolerance was induced by heating cells at 45 degrees C for 15 or 30 min and then incubating them at 37 degrees C for 5 or 24 h. This procedure resulted in four...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1994-05-01 00:00:00
abstract：:Dose-response relationships for X-ray-induced reciprocal translocations in spermatogonial stem cells of mutant and wild-type mice were established by spermatocyte analysis many cell generations after irradiation. The mutants studied were Wv/+, the viable allele of dominant spotting in the heterozygous state, and Slcon...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1994-02-01 00:00:00
abstract：:Two very different techniques for measuring the energy of neutrons in the energy range 0.1-10 MeV are presented and compared. A recoil-proton spectrometer is used to determine the energy spectra of neutrons produced by the d(4)-Be and p(4)-Be reactions down to the low-energy threshold of 0.7 MeV. The same radiation fi...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1989-04-01 00:00:00
abstract：:Chinese hamster V79 cells grown for several hours in suspension culture form spheroids which are more resistant to killing by ionizing radiation than cells grown on petri dishes, a phenomenon known as the "contact effect." Previous results using the alkali-unwinding assay as a measure of DNA damage have implicated dif...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1989-01-01 00:00:00
abstract：:Both plant senescence and plant response to ionizing radiation involve changes in gene expression and epigenetic profiles, that rely on the formation of reactive oxygen species. However, how the developmental stage of a plant affects its response to ionizing radiation has not been extensively studied. In this study, o...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR13840.1
更新日期：2015-02-01 00:00:00
abstract：:Human gliomas are among the most aggressive tumors, and they respond poorly to treatment. The efficacy of surgical, radiation and chemotherapy treatment of these tumors is limited by the development of resistance. Interventions aimed at altering the response of these tumors to radiation or chemotherapy treatments are ...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2007)168[183:HGUCTW]2.0.CO;2
更新日期：2007-08-01 00:00:00
abstract：:Evidence is presented for the formation of products in irradiated dinucleoside monophosphates in which both bases are damaged. The dinucleoside monophosphates d(GpT), d(GpC), d(TpG) and d(CpG) were X-irradiated in oxygenated aqueous solution. Product identification was by NMR spectroscopy. In products containing doubl...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1995-01-01 00:00:00
abstract：:Synchronous Chinese hamster ovary cells were treated in G1 or S phase with cycloheximide or procaine hydrochloride before and during heating at 43 degrees C. Cycloheximide and procaine apparently act by different mechanisms, with cycloheximide inhibiting protein synthesis and procaine hydrochloride supposedly affectin...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1990-06-01 00:00:00
abstract：:The immunocytochemical response to DNA damage induced by low-energy bismuth and carbon ions was investigated in normal human fibroblasts. Inside the nuclei, the traversing charged particles lead to the accumulation of proteins related to DNA lesions and repair along the ion trajectories. Irradiation under a standard g...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2003)159[0676:biohct]2.0.co;2
更新日期：2003-05-01 00:00:00
abstract：:The effects of reoxygenation on repair of potentially lethal radiation damage were investigated using MG-63 human osteosarcoma cells in vitro. When exponentially growing MG-63 cells were cultured under hypoxic conditions for 24 h, cells stopped growing and remained at a low density. The hypoxic cells were then reoxyge...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1997-02-01 00:00:00
abstract：:Dose-response curves for micronucleus (MN) formation were measured in Chinese hamster V79 and xrs6 (Ku80(-)) cells and in human mammary epithelial MCF10A cells in the dose range of 0.05-1 Gy. The Chinese hamster cells were exposed to 1 GeV/nucleon iron ions, 600 MeV/nucleon iron ions, and 300 MeV/nucleon iron ions (LE...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR0967.1
更新日期：2007-12-01 00:00:00
abstract：:Experimentally derived optical constants and X-ray attenuation cross sections were used to construct the complete dipole oscillator strength distribution for solid, dry DNA. Monte Carlo simulations of the energy loss by electrons of initial energy 5 keV to 1 MeV in DNA were performed using cumulative inelastic cross s...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1995-02-01 00:00:00
abstract：:The relationship between intracellular and extracellular pH was investigated in a murine tumor and normal tissue, prior to and following glucose injection. Isotransplants of the murine tumor FSa-II in the dorsum of the hind foot and leg muscle, were investigated in nonanesthetized mice. Extracellular pH was measured w...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1991-05-01 00:00:00
abstract：:It has been acknowledged for many years that radiation exposure induces delayed, non-targeted effects in the progeny of the irradiated cell. Evidence is beginning to demonstrate that among these delayed effects of radiation are epigenetic aberrations, including altered DNA methylation. To test the hypothesis that diff...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR2390.1
更新日期：2011-05-01 00:00:00
abstract：:In this study, we assessed the efficacy of unilamellar 110-nm liposomes encapsulating the chelating agent diethylenetriaminepentaacetic acid (DTPA) in plutonium-exposed rats. Rats were contaminated by intravenous administration of the soluble citrate form of plutonium. The comparative effects of liposomal and free DTP...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR14968.1
更新日期：2018-05-01 00:00:00
abstract：:Ionizing radiation induces chronic metabolic oxidative stress and a mutator phenotype in hamster fibroblasts that is mediated by H(2)O(2), but the intracellular source of H(2)O(2) is not well defined. To determine the role of mitochondria in the radiation-induced mutator phenotype, end points of mitochondrial function...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR1617.1
更新日期：2009-12-01 00:00:00
abstract：:While impairment of thyroid function has been demonstrated for high-dose external radiation (e.g., for Hodgkin's disease), the long-term functional effects of low-dose external radiation have not been fully explored. One hundred fifty-three subjects with a past history of thymic irradiation during infancy were stratif...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1987-06-01 00:00:00
abstract：:Pulse radiolysis and 60Co gamma radiolysis were used to study the effects of ionizing radiations on the activity of glutamate dehydrogenase. Hydroxyl radicals are considerably more effective than hydrated electrons in causing loss of enzymatic activity. Evidence is also presented that the free radical anions (SCN)-.2,...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1983-01-01 00:00:00
abstract：:We have evaluated the effect of X irradiation on the mesenchymal tissue growth (blood capillaries and stromal cells) in an angiogenesis system in the mouse. This was accomplished by implanting a polyvinyl alcohol sponge disc in the subcutis of the thorax, and quantifying the extent of growth reduction of capillaries a...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1990-10-01 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 risk of a radiological or nuclear public health emergency is a major growing concern of the U.S. government. To address a potential incident and ensure that the government is prepared to respond to any subsequent civilian or military casualties, the U.S. Department of Health and Human Services and the Department o...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR15137.1
更新日期：2018-12-01 00:00:00
abstract：:Late radiation damage to pig skin has been assessed at 104 weeks after exposure to sources of 90Sr/90Y (Emax 2.2 MeV) and 170Tm (Emax 0.9 MeV). Damage was assessed from measurements of dermal thickness in histological sections of irradiated skin and was compared with that of unirradiated skin to establish the relative...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1993-03-01 00:00:00
abstract：:To approach treatment of micrometastases of steroid receptor-rich cancers using estrogen receptor-directed therapy with Auger electrons, multicellular spheroids of the estrogen receptor-rich human breast cancer cell line, MCF-7, were prepared and exposed to a range of concentrations of an Auger electron-emitting estro...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1999-05-01 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：:While nontargeted and low-dose effects such as the bystander effect are now accepted, the mechanisms underlying the response have yet to be elucidated. It has been shown that the transfer of irradiated cell conditioned medium (ICCM) can kill cells that are not directly irradiated; however, to date the effect of ICCM c...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR1141.1
更新日期：2008-02-01 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：:Identification of medical countermeasures (MCM) to mitigate radiation damage and/or protect first responders is a compelling unmet medical need. The prostaglandin E2 (PGE2) analog, 16,16 dimethyl-PGE2 (dmPGE2), has shown efficacy as a radioprotectant and radiomitigator that can enhance hematopoiesis and ameliorate int...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RADE-20-00181.1
更新日期：2020-12-10 00:00:00
abstract：:In previous studies, flavonoids, orientin and vicenin, that were isolated from the leaf extract of Ocimum sanctum, were found to protect mice against radiation injury. Several flavonoids are known to be good antioxidants. Therefore, the effect of orientin and vicenin on radiation-induced lipid peroxidation in vivo and...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2000)154[0455:rpbtof]2.0.co;2
更新日期：2000-10-01 00:00:00
abstract：:Experiments were performed to test whether significant amounts of pyrimidine dimers are produced in cultured cells of tobacco (Nicotiana tabacum L. var. Xanthi) and of Haplopappus gracilis by ultraviolet light in the biological dose range and whether either or both dark and light repair systems exist in these cells. T...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1968-11-01 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
