Abstract:
:The hyperthermic inhibition of cellular DNA synthesis, i.e., reduction in replicon initiation and delay in DNA chain elongation, was previously postulated to be involved in the induction of chromosomal aberrations believed to be largely responsible for killing S-phase cells. Utilizing asynchronous Chinese hamster ovary cells heated for 15 min at 45.5 degrees C, an increase in single-stranded regions in replicating DNA (as measured by BND-cellulose chromatography) persisted in heated cells for as long as replicon initiation was affected. Alkaline sucrose gradient analyses of cells pulse-labeled immediately after heating with [3H]thymidine and subsequently chased at 37 degrees C revealed that these S-phase cells can eventually complete elongation of the replicons in operation at the time of heating, but required about six times as long relative to control cells which completed replicon elongation within 4 h. DNA chain elongation into multicluster-sized molecules was prevented for up to 18 h in these heated cells, resulting in a buildup of cluster-sized molecules (approximately 120-160 S) mainly because of the long-term heat damage to the replicon initiation process. Utilizing bromodeoxyuridine (BrdU)-propidium iodide bivariate analysis on a flow cytometer to measure cell progression, control cells pulsed with BrdU and chased in unlabeled medium progressed through S and G2M with cell division starting after 2 h of chase time. In contrast, the majority of the heated S-phase cells progressed slowly and remained blocked in S phase for about 18 h before cell division was observed after 24 h postheat. Our findings suggest that possible sites for where the chromosomal aberrations may be occurring in heated S-phase cells are either (1) at the persistent single-stranded DNA regions or (2) at the regions between clusters of replicons, because this long-term heat damage to the DNA replication process might lead to many opportunities for abnormal DNA and/or protein exchanges to occur at these two sites.
journal_name
Radiat Resjournal_title
Radiation researchauthors
Wong RS,Thompson LL,Dewey WCsubject
Has Abstractpub_date
1988-04-01 00:00:00pages
125-37issue
1eissn
0033-7587issn
1938-5404journal_volume
114pub_type
杂志文章abstract::The immune response of guinea pigs to Q fever vaccine following 75 to 250 R (60 to 180 rads) of acute whole-body irradiations was investigated. Complement-fixing (CF) antibody titers and protection against febrile response to challenge with virulent Coxiella burnetii were studied. Exposures ranging from 75 to 250 R, 2...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1968-10-01 00:00:00
abstract::The linear no-threshold extrapolation from a dose-response relationship for ionizing radiation derived at higher doses to doses for which regulatory standards are proposed is being challenged by some scientists and defended by others. It appears that the risks associated with exposures to doses of interest are below t...
journal_title:Radiation research
pub_type:
doi:
更新日期:1998-12-01 00:00:00
abstract::Molecular oxygen has long been recognized as a powerful radiosensitizer that enhances the cell-killing efficiency of ionizing radiation. Radiosensitization by oxygen occurs at very low concentrations with the half-maximum radiosensitization at approximately 3 mmHg. However, robust hypoxia-induced signal transduction c...
journal_title:Radiation research
pub_type: 杂志文章,评审
doi:10.1667/RR13959.1
更新日期:2015-05-01 00:00:00
abstract::The effects of 2.45-GHz continuous-wave microwaves (SAR = 130 mW/g) on the expression of the interferon-regulated enzymes 2'-5'-oligoadenylate (2-5A) synthetase(s) and 2-5A-dependent endoribonuclease (RNase L) were studied in murine L929 cells. Cells growing as monolayers were removed from the substratum and placed in...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1991-08-01 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::Electron microbeam experiments are planned or under way to explore in part the question regarding whether the bystander effect is a general phenomenon or is restricted to high-LET radiation. Since low-LET radiations scatter more readily compared to high-LET radiations, identifying bystander cells and assessing the pot...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/0033-7587(2001)155[0089:moakem]2.0.co;2
更新日期:2001-01-01 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::Gemcitabine (dFdCyd) shows broad antitumor activity in solid tumors in chemotherapeutic regimens or when combined with ionizing radiation (radiosensitization). While it is known that mismatches in DNA are necessary for dFdCyd radiosensitization, the critical event resulting in radiosensitization has not been identifie...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR14443.1
更新日期:2016-11-01 00:00:00
abstract::The functional and morphological response of the remaining hypertrophied kidney in unilaterally nephrectomized rats to single doses of 0-20 Gy X rays was investigated. Functional and histological end points were assessed serially 4-24 weeks postirradiation. Renal irradiation led to time- and dose-dependent reductions ...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/0033-7587(2001)155[0481:trotti]2.0.co;2
更新日期:2001-03-01 00:00:00
abstract::On future missions into deep space, astronauts will be required to work more autonomously than on previous missions, and thus their ability to perform executive functions could be critical to mission success. In this study, we determined the effect that ≤15 cGy of 600 MeV/n 56Fe particles has on attentional set-shifti...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR15085.1
更新日期:2018-12-01 00:00:00
abstract::The effects of amiloride (an inhibitor of Na+/H+ antiport), DIDS (an inhibitor of Na(+)-coupled and Na(+)-independent HCO3-/Cl- exchange) and nigericin (K+/H+ ionophore) alone and in various combinations on the intracellular pH (pHi) and thermosensitivity of SCK tumor cells were studied. Hyperthermia alone at 43 degre...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1992-01-01 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::The goal of this study was to make a comparison between stereotactic brachytherapy implants and linear accelerator-based radiosurgery of brain tumors with respect to physical dose distributions and radiobiological efficacy. Twenty-four treatment plans made for irradiation of brain tumors with low-dose-rate (125)I brac...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR3529.1
更新日期:2006-06-01 00:00:00
abstract::To characterize the role of the cerebrovascular response in the development of brain injury after focal irradiation, 125I sources were implanted in frontal white matter of the brain of normal dogs; dose was 20 Gy, 7.5 mm from the source. Cerebral blood flow, vascular volume and mean transit time of blood were quantifi...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1992-05-01 00:00:00
abstract::The recent demonstration of nanoscale scintillators has led to interest in the combination of radiation and photodynamic therapy. In this model, scintillating nanoparticles conjugated to photosensitizers and molecular targeting agents would enhance the targeting and improve the efficacy of radiotherapy and extend the ...
journal_title:Radiation research
pub_type: 杂志文章,评审
doi:10.1667/RR1470.1
更新日期:2009-02-01 00:00:00
abstract::The effects of multiple-dose gamma irradiation on the shape of survival curves were studied with mouse C3H 10T1/2 cells maintained in contact-inhibited plateau phase. The dose-fractionation intervals included 3, 6, and 24 h. Following three fractionated doses (5 Gy per dose) of exposures, cells responded to further ir...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1986-06-01 00:00:00
abstract::In higher eukaryotes, DNA double-strand breaks (DSBs) induced by ionizing radiation activate checkpoints that delay progression through the cell cycle. Compared to delays in other phases of the cell cycle, delays induced in G(2) are longer and frequently correlate with resistance to killing by radiation. Therefore, mo...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR2165.1
更新日期:2010-10-01 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::To improve radioimmunotherapy with Auger electron emitters, we assessed whether the biological efficiency of (125)I varied according to its localization. A-431 and SK-OV-3 carcinoma cells were incubated with increasing activities (0-4 MBq/ml) of (125)I-labeled vectors targeting the cell membrane, the cytoplasm or the ...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR1359.1
更新日期:2008-08-01 00:00:00
abstract::Human cancers have multiple alterations in cell signaling pathways that promote resistance to cytotoxic therapy such as X rays. Parthenolide is a sesquiterpene lactone that has been shown to inhibit several pro-survival cell signaling pathways, induce apoptosis, and enhance chemotherapy-induced cell killing. We invest...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR1128.1
更新日期:2007-12-01 00:00:00
abstract::Two different sets of Monte Carlo computations were carried out for the study of dose penetration of monoenergetic, low-energy (10 to 100 keV) photon beams incident on slabs of tissue. One program took into account coherent scattering and considered electron binding when finding the angle of scattering during incohere...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1983-11-01 00:00:00
abstract::Radiotherapy is one of the major treatment modalities for the management of various cancers, however, it is limited by the severe side effects and complications experienced by some patients. Nicaraven, a chemically synthesized hydroxyl radical-specific scavenger, has been shown to protect normal tissues from radiation...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR14614.1
更新日期:2017-02-22 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::1. A survival curve for the colony-forming ability of mouse bone marrow cells irradiated in vivo with Co60 gamma-rays has been obtained. The curve may be characterized by D0 of 95 rads and an extrapolation number of 1.5. 2. Comparison with the survival curve obtained for irradiated in vitro indicated a statistically s...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1962-06-01 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::The cellular sites for damage in mammalian cells caused by 193-nm radiation from an argon fluoride excimer laser were investigated. The ability of Chinese hamster ovary cells to reduce a tetrazolium dye (MTT) was decreased to 37% of unirradiated control by 2.5 x 10(3) J/m2 of 193-nm radiation when measured either 4 or...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1990-05-01 00:00:00
abstract::Groups of rats were administered different doses of X rays (7.5 and 15 Gy), and the effect on the permeability of their lungs was evaluated during a time frame within which radiation pneumonitis develops. Sham-exposed animals served as controls. End points surveyed included lung weight and increases in the total prote...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1993-05-01 00:00:00
abstract::The non-random distribution of DNA breakage in PFGE (pulsed-field gel electrophoresis) experiments poses a problem of proper subtraction of the background DNA damage to obtain a fragment-size distribution due to radiation only. A naive bin-to-bin subtraction of the background signal will not result in the right DNA ma...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR0663.1
更新日期:2006-12-01 00:00:00
abstract::The exposure of peripheral blood mononuclear cells (PBMCs) was performed in a 10-T static magnetic field. Without lymphocyte stimulation, there were no significant differences in the viability of the exposed and unexposed CD4(+) T cells, CD8(+) T cells, B cells, and natural killer (NK) cells. The expression of Th1 typ...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/0033-7587(2003)159[0775:eotsmf]2.0.co;2
更新日期:2003-06-01 00:00:00
abstract::Pentamidine is similar to rhodamine-123 in chemical structure and state of electron charge, and rhodamine-123 was previously shown to be a hyperthermic sensitizer under appropriate cell culture conditions. The present experiments were carried out to determine whether pentamidine would potentiate hyperthermic cell kill...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1988-11-01 00:00:00