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 irradiation by displaying a survival curve with a much reduced shoulder width (Dq) compared to that of the survival curve measured in cells irradiated with single-graded doses alone. The effect on the mean lethal dose (D0) was small and appeared to be significant. The effect on reduction of Dq could not be completely overcome by lengthening the fractionation intervals from 3 to 6 h or 24 h, times in which repair of sublethal damage (SLD) measured by simple split-dose scheme and potentially lethal damage (PLD) measured by postirradiation incubation was completed. Other experiments showed that pretreatments of cells with fractionated irradiation appeared to slow down the cellular repair processes of SLD and PLD. Therefore, the observed change in the shape of survival curves after fractionation treatments may be attributed to a reduction of the cells' capacity for damage accumulation by an enhancement of the lethal expression of SLD and PLD. Although the molecular mechanism(s) is not known, the results of this study indicate that the acute graded dose-survival curve cannot be used a priori to extrapolate and reliably predict results of hyperfractionation. It is probable that for a nondividing or slowly dividing cell population, such an extrapolation may lead to an underestimation of cell killing. Furthermore, the findings of this investigation appear to support an interpretation, alternative to the high-linear energy transfer (LET) track-end postulate, for the effects on cell survival seen at low doses or low dose rates.
journal_name
Radiat Resjournal_title
Radiation researchauthors
Ngo FQ,Youngman K,Suzuki S,Koumoundouros I,Iliakis Gsubject
Has Abstractpub_date
1986-06-01 00:00:00pages
380-95issue
3eissn
0033-7587issn
1938-5404journal_volume
106pub_type
杂志文章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::Diethylenetriaminepentaacetic acid (DTPA) is currently still the only known chelating drug that can be used for decorporation of internalized plutonium (Pu) and americium (Am). It is generally assumed that chelation occurs only in biological fluids, thus preventing Pu/Am deposition in target tissues. We postulate that...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR14193.1
更新日期:2016-06-01 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::To characterize the differences in the radiosensitivity of individual populations of human hematopoietic stem/progenitor cells (HSPCs), we examined the relationship among cell surface antigens, clonogenic potential and radiation survival. The expressions of CD34, CD38, CD45RA, CD110 and Tie-2, early differentiation pa...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR1839.1
更新日期:2010-02-01 00:00:00
abstract::A dose of heat which renders 98% of a population of Chinese hamster ovary cells reproductively dead has no significant effect on their Na+, K+, or Mg2+ content by 28 h postheat. In contrast, the cellular Ca2+ content increases in a dose-dependent manner as observed at 22 h after heating for 15-35 min at 45 degrees C. ...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1986-02-01 00:00:00
abstract::Alteration of the radiation-induced changes in wound contraction, collagen synthesis and wound histology by ascorbic acid was studied in mice exposed to 10, 16 and 20 Gy of fractionated (2 Gy/fraction) gamma radiation. The animals were given double-distilled water or ascorbic acid daily before exposure to 2 Gy/day of ...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/0033-7587(2003)159[0371:eoteoa]2.0.co;2
更新日期:2003-03-01 00:00:00
abstract::Flynn, A. A., Green, A. J., Pedley, R. B., Boxer, G. M., Boden, R. and Begent, R. H. J. A Mouse Model for Calculating the Absorbed Beta-Particle Dose from (131)I- and (90)Y-Labeled Immunoconjugates, Including a Method for Dealing with Heterogeneity in Kidney and Tumor. Radiat. Res. 156, 28-35 (2001). Conventional inte...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/0033-7587(2001)156[0028:ammfct]2.0.co;2
更新日期:2001-07-01 00:00:00
abstract::We describe a rapid assay to predict intrinsic radiosensitivity of normal tissues based on the radiation-induced cytotoxic response of a number of types of white blood cells. Twenty-four hours after irradiation, leukocytes were prepared for analysis by flow cytometry. Radiation-induced cytotoxicity was characterized b...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1997-01-01 00:00:00
abstract::The incidence of breast cancer was determined in 4940 women treated for tuberculosis between 1925 and 1954 in Massachusetts. Among 2573 women examined by X-ray fluoroscopy an average of 88 times during lung collapse therapy and followed for an average of 30 years, 147 breast cancers occurred in contrast to 113.6 expec...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1991-02-01 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::Studies were conducted to determine the effects of BeSO4 or X rays, alone and in combination, on cell cycle kinetics, cell killing, and the production of chromosome aberrations in Chinese hamster ovary (CHO) cells. The concentration of BeSO4 required to kill 50% of CHO cells exposed to BeSO4 for 20 h was determined to...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1989-12-01 00:00:00
abstract::The potential carcinogenic effects of internally deposited alpha-particle-emitting nuclides, notably plutonium, in the liver in humans are unknown but are of concern in relation to exposures from the nuclear industry. However, patients injected with the radiographic contrast medium Thorotrast are chronically exposed t...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1994-02-01 00:00:00
abstract::Therapeutic gain factors (TGFs) have been determined for three spontaneous tumors of the C3H mouse treated by photons + normobaric oxygen (O2(1) ATA), photons + hyperbaric oxygen (O2 3 ATA), photons + misonidazole, or fast neutrons. The tumors were early generation isotransplants of spontaneous tumors: MCaIV, a mammar...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1988-12-01 00:00:00
abstract::Tissue ablation by ultraviolet excimer lasers results in exposure of viable cells to subablative doses of radiation. To understand the potential biological consequences better, we have studied changes in gene expression in cultured human skin fibroblasts exposed to either 193- or 248-nm laser light. Northern blot anal...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1992-09-01 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::Asynchronously growing V79 cells were assayed for mutation induction following exposure to hyperthermia either immediately before or after being irradiated with 60Co gamma rays. Hyperthermia exposures consisted of either 43.5 degrees C for 30 min or 45 degrees C for 10 min. Each of these heat treatments resulted in a ...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1989-08-01 00:00:00
abstract::We report results for chromosomal aberrations in human peripheral blood lymphocytes after they were exposed to high-energy iron ions with or without shielding at the HIMAC, AGS and NSRL accelerators. Isolated lymphocytes were exposed to iron ions with energies between 200 and 5000 MeV/nucleon in the 0.1-1-Gy dose rang...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/rr3362.1
更新日期:2005-10-01 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::The current status of particle radiotherapy from a historical perspective is presented. This is done with a personal view and contains personal references and memories during the development of particle radiotherapy. The particles covered are fast neutrons, neutron capture therapy, protons, helium ions, pions and heav...
journal_title:Radiation research
pub_type: 历史文章,杂志文章
doi:
更新日期:1996-04-01 00:00:00
abstract::Induction of interphase death was examined in Chinese hamster ovary cells exposed to accelerated heavy ions (carbon, neon, argon and iron) of various linear energy transfers (LETs) (10-2000 keV/microm). The fraction of cells that underwent interphase death was determined by observing individual cells with time-lapse p...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1997-11-01 00:00:00
abstract::The response of the testes of two strains of adult rats (Sprague-Dawley and Wistar) to graded single doses and split doses of 230 kVp X rays has been investigated. A marked difference was noted between the strains in the response of the clonogenic spermatogonia to irradiation, as measured histologically by the repopul...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1987-10-01 00:00:00
abstract::The structural maintenance of chromosome 1 (Smc1) protein is a member of the highly conserved cohesin complex and is involved in sister chromatid cohesion. In response to ionizing radiation, Smc1 is phosphorylated at two sites, Ser-957 and Ser-966, and these phosphorylation events are dependent on the ATM protein kina...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR2402.1
更新日期:2011-03-01 00:00:00
abstract::The efficacy of photodynamic therapy is dependent upon the optical dose rate or upon the fractionation schedule on the light. These effects are thought to be limited by the time required for oxygen diffusion from the capillaries, since this therapy can consume oxygen faster than it can be supplied to tissues distant f...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.2307/3579621
更新日期:1997-05-01 00:00:00
abstract::Mice were irradiated with 1 Gy of fission neutrons. At intervals up to 15 days after irradiation undifferentiated spermatogonia were counted in whole mounts of seminiferous tubules in up to eight stages of the epithelial cycle. From Day 6 onward lower numbers of spermatogonia were found in the areas which were in stag...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1984-03-01 00:00:00
abstract::Peroxidation of unconjugated polyunsaturated fatty acids such as linolenic acid proceeds through a free radical chain mechanism and is accompanied by the formation of conjugated dienes such as hydroperoxides. In an investigation of radiation-induced oxidation of aqueous linolenate, we have measured two indexes of pero...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/0033-7587(2000)153[0201:eotfod]2.0.co;2
更新日期:2000-02-01 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::In recent years, there has been increasing concern over the possibility of a radiological or nuclear incident occurring somewhere in the world. Intelligence agencies frequently report that terrorist groups and rogue nations are seeking to obtain radiological or nuclear weapons of mass destruction. In addition, there e...
journal_title:Radiation research
pub_type:
doi:10.1667/RR14810.1
更新日期:2017-08-01 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::We studied the role of cysteine as an intracellular radiation protector under conditions in which both oxygen and thiols were monitored at 37 degrees C. In HCT-116 human colon cancer cells, the intracellular cysteine content affects the radiation survival dramatically at intermediate oxygen levels, but not at zero or ...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/0033-7587(2001)156[0388:tkmfro]2.0.co;2
更新日期:2001-10-01 00:00:00
abstract::Clustered damage sites other than double-strand breaks (DSBs) have the potential to contribute to deleterious effects of ionizing radiation, such as cell killing and mutagenesis. In the companion article (Semenenko et al., Radiat. Res. 164, 180-193, 2005), a general Monte Carlo framework to simulate key steps in the b...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/rr3414
更新日期:2005-08-01 00:00:00