Abstract：
:Although conclusive evidence has been obtained for the presence of radiation-induced bystander effects, the mechanisms that trigger and regulate these processes are still largely unknown. The bystander effect may play a critical role in determining the biological effectiveness of low-dose exposures, but questions on how to incorporate it into current models and extrapolate the risks of radiation-induced carcinogenesis are still open. The Gray Cancer Institute soft X-ray microbeam has been used to investigate the dose-response relationship of the bystander effect below 0.5 Gy. The survival response of V79 cells was assessed after the irradiation of a single cell within a population with a submicrometer-size beam of carbon K X rays (278 eV). Above 0.3 Gy, the measured bystander cell killing was in agreement with previously published data; however, a significant increase in the scatter of the data was observed in the low-dose region (<0.3 Gy). The data distribution observed indicates a binary behavior for triggering of the bystander response. According to our hypothesis, the probability of triggering a bystander response increases approximately linearly with the dose delivered to the single selected cell, reaching 100% above about 0.3 Gy. The magnitude of the bystander effect, when triggered, is approximately constant with the dose and results in an overall approximately 10% reduction in survival in our system. This suggests that the event that triggers the emission of the bystander signal by the hit cell is an all-or-nothing process. Extrapolation of the data indicates that when a single fast electron traverses a V79 cell, there is a probability of approximately 0.3% that the cell will emit the bystander signal. The data presented in this paper have also been analyzed statistically to test the possibility that complex DNA double-strand breaks may be the initial critical event.
journal_name
Radiat Resjournal_title
Radiation researchauthors
Schettino G,Folkard M,Michael BD,Prise KMdoi
10.1667/rr3319subject
Has Abstractpub_date
2005-03-01 00:00:00pages
332-6issue
3eissn
0033-7587issn
1938-5404pii
RR3319journal_volume
163pub_type
杂志文章abstract：:Impaired fluid and electrolyte transport in the intestine is a well-recognized characteristic of radiation-induced pathologies in the gastrointestinal tract. The aim of this study was to investigate the responsiveness of the epithelium of the colon of the rat to electrical and pharmacological (serotonin, carbachol) st...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1999-04-01 00:00:00
abstract：:After a planned or unplanned radiation exposure, determination of absorbed dose has great clinical importance, informing treatment and triage decisions in the exposed individuals. Biodosimetry approaches allow for determination of dose in the absence of physical measurement apparatus. The current state-of-the-art biod...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR15283.1
更新日期：2019-05-01 00:00:00
abstract：:A histopathological study was carried out on the spinal cord of rats after boron neutron capture (BNC) irradiation. Rats were irradiated with thermal neutrons alone or in combination with borocaptate sodium (BSH) or p-boronophenylalanine (BPA). Spinal cords were examined 1 year after irradiation, or at earlier times i...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1996-09-01 00:00:00
abstract：:The effects of ionizing radiation, with or without the anti-angiogenic agent anginex (Ax), on multiple myeloma growth were tested in a SCID-rab mouse model. Mice carrying human multiple myeloma cell-containing pre-implanted bone grafts were treated weekly with various regimens for 8 weeks. Rapid multiple myeloma growt...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR1734.1
更新日期：2010-06-01 00:00:00
abstract：:The mortality experience between 1956 and 1985 of 8977 males employed by Atomic Energy of Canada Limited is reported. A total of 4260 men, 47% of the cohort, were exposed to low doses of external ionizing radiation at low dose rates, with a mean cumulative equivalent dose of 52.1 mSv. For cancers as a whole the excess...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1993-03-01 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：:Tumor radiotherapy with large-field irradiation results in an increase of p53-dependent apoptosis of the radiosensitive hematopoietic stem cells. Proapoptotic PUMA is a transcriptional target of p53. Thus suppression of PUMA expression by gene therapy with the transcription repressor SNAI2 as transgene might be a pote...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR1952.1
更新日期：2010-05-01 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：: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：:The increasing use of mobile phones by children and teenagers has raised concerns about their safety. Addressing such concerns is difficult, because no data are available on possible effects from long-term exposure to radiofrequency (RF) fields during the development of the nervous system. Possible morphological and f...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR1002.1
更新日期：2007-10-01 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：:In this study, we sought to determine how diffusion-weighted imaging (DWI) and proton magnetic resonance spectroscopy (1H-MRS) features are associated with histopathological results, and explored the cellular mechanisms of DWI and 1H-MRS in early radiosensitivity of transplanted liver tumors. VX2 tumors were implanted...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR15140.1
更新日期：2019-01-01 00:00:00
abstract：:Chinese hamster ovary (CHO) cells became thermotolerant after treatment with either heat for 10 min at 45.5 degrees C or incubation in 100 microM sodium arsenite for 1 h at 37 degrees C. Thermotolerance was tested using heat treatment at 45 degrees C or 43 degrees C administered 6-12 h after the inducing agent. At 45 ...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1990-03-01 00:00:00
abstract：:Exposure to ionizing radiation alone or combined with traumatic tissue injury is a crucial life-threatening factor in nuclear and radiological incidents. Radiation injuries occur at the molecular, cellular, tissue and systemic levels; their mechanisms, however, remain largely unclear. Exposure to radiation combined wi...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR14647.1
更新日期：2017-11-01 00:00:00
abstract：:Radiation exposure from a number of terrestrial sources is associated with an increased risk for atherosclerosis. Recently, concern over whether exposure to cosmic radiation might pose a similar risk for astronauts has increased. To address this question, we examined the effect of 2 to 5 Gy iron ions ((56)Fe), a parti...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR2482.1
更新日期：2011-06-01 00:00:00
abstract：:Thymic explant cultures were used to study the radiosensitivity of nonlymphoid thymic components in dogs. Thymic fragments from fetal (50 days gestation), newborn, and juvenile (70 days old) dogs were irradiated in vitro at 0, 0.5, 1, 2, or 4 Gy prior to culture. Colonies were classified as epithelial, spindle, or mix...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1988-07-01 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：:A recent publication by Leith et al. (Cancer Res. 51, 4111-4113, 1991) showed that administration of epidermal growth factor (EGF) (0.25 mg/kg; q.i.d. x 7) to mice bearing xenografted A431 human epidermoid cancers produced increased tumor growth and a reduction of the percentage of hypoxic cells within neoplasms. In c...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1992-11-01 00:00:00
abstract：:Normal human fibroblasts in plateau phase ( congruent with 95% G(1) phase) were stained with the vital nuclear dye Hoechst 33342 (blue fluorescence) or the vital cytoplasmic dye Cell Tracker Orange (orange fluorescence) and plated at a ratio of 1:1. Only the blue-fluorescing nuclei were microbeam-irradiated with a def...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/rr3236
更新日期：2004-10-01 00:00:00
abstract：:The radiation dose received by crew members in interplanetary space is influenced by the stage of the solar cycle. Using the recently developed models of the galactic cosmic radiation (GCR) environment and the energy-dependent radiation transport code, we have calculated the dose at 0 and 5 cm water depth; using a com...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1994-05-01 00:00:00
abstract：:Single crystals of the co-crystalline complex of 1-methyluracil and 9-ethyladenine were X-irradiated and studied using EPR, ENDOR and FSE spectroscopic techniques at 10 K. All together seven radicals were identified, and experimental evidence for at least one more species, as well as for a very low population of radic...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1998-02-01 00:00:00
abstract：:Previous work from our laboratory suggested that neuronal chromatin structure may be altered immediately after exposure to ionizing radiation. In the present study, whole brains of 4-month-old male Fisher 344 rats were irradiated with a dose of 25 Gy. The kinetics of restoring the chromatin structure to its unirradiat...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1988-04-01 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：:A plasma membrane-rich fraction has been separated from liver cells and cells of two solid rat tumors. D23 hepatoma and MC7 sarcoma. On the basis of marker enzyme activity the membranes separating at the 31-41% interface on the discontinuous sucrose gradient were enriched 15- to 19-fold. No significant differences in ...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1991-01-01 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 hypothesis of boron neutron capture therapy (BNCT) research has been that the short-range, high-linear energy transfer radiation produced by the capture of thermal neutrons by (10)B will potentially control tumor and spare normal tissue only if the boron compound selectively targets tumor tissue within the treatme...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR3592.1
更新日期：2006-08-01 00:00:00
abstract：:The model of radiation action that is presented relates the surviving fraction of irradiated cells to unrepaired DNA double-strand breaks (DSBs). The following assumptions are made in the model: (i) A DNA fragment created by the induced DSBs may move out of its chromosome (become lost), and the probability of that pro...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1989-06-01 00:00:00
abstract：:Experiments were performed to determine whether diurnal variations in apoptosis in the mouse small intestine after irradiation with 2.5 Gy gamma rays depended on the time of day that the mice were irradiated, the time of day that the mice were sacrificed or the interval between irradiation and sacrifice. Experiments w...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1998-04-01 00:00:00
abstract：:The incidence of micronuclei was evaluated to assess the induction of an adaptive response to non-ionizing radiofrequency (RF) radiation in peripheral blood lymphocytes collected from five different human volunteers. After stimulation with phytohemagglutinin for 24 h, the cells were exposed to an adaptive dose of 900 ...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR1687.1
更新日期：2009-06-01 00:00:00
abstract：:The increasingly wider use of microdosimetry in fields other than pure radiobiological research, especially in "practical" domains such as radiation protection and medical physics, has created a number of new practitioners who are not fully acquainted with many of the experimental pitfalls which beset the aspiring mic...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1990-10-01 00:00:00
