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- to 100-fold for a variety of conditions when cells are heated either in suspension culture or as monolayers with or without trypsinization. The protective effect associated with feeder cells appears to be associated with close cell-to-cell proximity. However, when cells are heated without trypsinization about 24 hr or later after plating, when adaptation to monolayer has occurred, the protective effect is reduced; i.e., addition of feeder cells enhances survival much less, for example, about 2- to 3-fold at 10(-2)-10(-3) survival. Also, the survival of a cell to heat is independent of whether the neighboring cell in a microcolony is destined to live or die. Finally, if protective effects associated with cell density do occur and are not controlled, serious artifacts can result as the interaction of heat and radiation is studied; for example, survival curves can be moved upward, and thus changed in shape as the number of cells plated is increased with an increase in the hyperthermic treatment or radiation dose following hyperthermia. Therefore, to understand mechanisms and to obtain information relevant to populations of cells in close proximity, such as those in vivo, these cellular population density effects should be considered and understood.
journal_name
Radiat Resjournal_title
Radiation researchauthors
Highfield DP,Holahan EV,Holahan PK,Dewey WCsubject
Has Abstractpub_date
1984-01-01 00:00:00pages
139-53issue
1eissn
0033-7587issn
1938-5404journal_volume
97pub_type
杂志文章abstract::Telomeres cap the ends of chromosomes, preventing end-to-end fusions and subsequent chromosome instability. Here we used a telomerase knockout model to investigate whether telomerase participates in the processes of DNA break repair by de novo synthesis of telomere repeats at broken chromosome ends (chromosome healing...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/rr3203
更新日期:2004-08-01 00:00:00
abstract::Inhalation and ingestion of 137Cs and other long-lived radionuclides can occur after large-scale accidental or malicious radioactive contamination incidents, resulting in a complex temporal pattern of radiation dose/dose rate, influenced by radionuclide pharmacokinetics and chemical properties. High-throughput radiati...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RADE-20-00042.1
更新日期:2020-10-16 00:00:00
abstract::At the Swiss Institute for Nuclear Research (SIN) cancer patients are irradiated with negatively charged pi mesons using a 60-beam medical pion generator, the Piotron. A low-pressure tissue-equivalent proportional counter was used to measure absorbed dose and microdosimetric spectra. A method was developed to allow di...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1985-01-01 00:00:00
abstract::Abstract The present study was undertaken to investigate the ability of dietary supplements to reduce the formation and severity of cataracts in mice irradiated with high-energy protons or iron ions, which are important components of the radiation encountered by astronauts during space travel. The mice were exposed to...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR1398.1
更新日期:2010-03-01 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::This commentary considers modulation as a factor of potential biological importance in assessment of risk of radiofrequency (RF) energy emitted by communications systems and other technologies. Modulation introduces a spread of frequencies into a carrier waveform, but in nearly all cases this spread is small compared ...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/rr3191
更新日期:2004-08-01 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::Cells that have been grown as multicell tumor spheroids exhibit radioresistance compared to the same cells grown in monolayers. Comparison of potentially lethal damage (PLD) repair and its kinetics was made between 9L cells grown as spheroids and confluent monolayers. Survival curves of cells plated immediately after ...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1988-06-01 00:00:00
abstract::Base damage flanking a radiation-induced DNA double-strand break (DSB) may contribute to DSB complexity and affect break repair. However, to date, an isolated radiation-induced DSB has not been assessed for such structures at the molecular level. In this study, an authentic site-specific radiation-induced DSB was prod...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR0628.1
更新日期:2006-11-01 00:00:00
abstract::Prior to whole-liver irradiation (0, 15, 25 Gy) rats were not treated, placed on a protein-deficient diet for 2 weeks, administered cyclophosphamide, and/or depleted of intracellular glutathione by injection with buthionine sulfoximide and diethyl maleate. At various times (0 to 84 days) after 0- and 25-Gy liver irrad...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1992-03-01 00:00:00
abstract::Alteration of adhesion molecule expression on endothelial cells has a direct connection with ionizing radiation-induced atherosclerosis, which is an adverse effect observed after radiotherapy. However, minimal attention has been given to monocytes/macrophages role in atherosclerosis development, which are exposed to t...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR3119.1
更新日期:2013-01-01 00:00:00
abstract::These studies examined the effects of X radiation and interleukin 3 (IL-3), which is an effective cytokine for the generation of megakaryocytopoiesis from X-irradiated hematopoietic stem/progenitor cells, on the terminal process of human megakaryocytopoiesis and thrombopoiesis. Mature megakaryocytes were induced by cu...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR1519.1
更新日期:2009-09-01 00:00:00
abstract::Irradiation from internally deposited radionuclides induces malignant tumors. Ingested long-lived radionuclides accumulate in specific organs that are irradiated throughout life. To elucidate why the development of malignant tumors requires long-term internal exposure, of the order of decades, despite the fact that ir...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR1492.1
更新日期:2009-04-01 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::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::Monte Carlo simulations are used in the development of a nanotechnology-based multi-pixel beam array small animal microirradiation system. The microirradiation system uses carbon nanotube field emission technology to generate arrays of individually controllable X-ray pixel beams that electronically form irregular irra...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR1453.1
更新日期:2009-03-01 00:00:00
abstract::The concept of curvature in dose-response relationships figures prominently in radiation biology, encompassing a wide range of interests including radiation protection, radiotherapy and fundamental models of radiation action. In this context, the ability to detect even small amounts of curvature becomes important. Sta...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR14520.1
更新日期:2017-01-01 00:00:00
abstract::Wortmannin has been shown to be an efficient radiosensitizer. Since wortmannin is able to inhibit DNA-dependent protein kinase (DNA-PK) and double-strand break (DSB) rejoining, it is believed that its mechanism of radiation sensitization is through the inhibition of DNA-PK-mediated repair of DSBs. However, since wortm...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1999-02-01 00:00:00
abstract::Reproductive cell death (RCD) occurs after one or more cell divisions resulting from an insult such as radiation exposure or other treatments with carcinogens or mutagens. The radioadaptive response for RCD is usually investigated by in vitro or in vivo clonogenic assay. To date, this has not been demonstrated in the ...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR14368.1
更新日期:2016-04-01 00:00:00
abstract::Cisplatin and binuclear rhodium (Rh2) carboxylates appear to potentiate radiation-induced killing of Salmonella typhimurium cells largely as a consequence of one-electron reduction that leads to an active radiolytic product. This conclusion is supported by results from experiments wherein the hydrated electron and the...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1991-07-01 00:00:00
abstract::The killing effects of ionizing radiation on MOLT-4 cells were studied using colony formation assays, dye exclusion tests, and cell growth analysis. When MOLT-4 cells were exposed to X rays, the fraction of cells stained with erythrosin B increased markedly during the incubation after irradiation at 37 degrees C and r...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1993-08-01 00:00:00
abstract::Mutation and killing induced by X radiation and 60CO gamma radiation were studied in six different histidine-requiring auxotrophs of Salmonella typhimurium. Strain TA100, which is sensitive to base-pair substitutions, and strains TA2637 and TA98, which are sensitive to frameshifts, carry the pKM101 plasmid and exhibit...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1984-11-01 00:00:00
abstract::Ionizing radiation induces bistranded clustered damages--two or more abasic sites, oxidized bases and strand breaks on opposite DNA strands within a few helical turns. Since clusters are refractory to repair and are potential sources of double-strand breaks (DSBs), they are potentially lethal and mutagenic. Although i...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/rr3498.1
更新日期:2006-02-01 00:00:00
abstract::This study demonstrates that mice, similar to humans, have a common mitochondrial DNA deletion (3,860 bp) that encodes 5 transfer RNA genes and 5 polypeptide genes that is related to aging, tissue type and radiotoxicity. Our research indicates that the deletion ratio in the liver was significantly higher than in the b...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR3373.1
更新日期:2013-10-01 00:00:00
abstract::The reactions of free and DNA-bound 2,2,5,5-tetramethylpyrrolidine-N-oxyl (PROXYL) probes with radicals generated during radiolysis of dilute aqueous solutions of DNA were examined. For the free PROXYL probe in deaerated solution with each of the four nucleotides (dAMP, dCMP, dGMP, and TMP) it was found that the pyrim...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1987-10-01 00:00:00
abstract::Ionizing radiation is known to effect development during early life stages. Lake whitefish (Coregonus clupeaformis) represent a unique model organism for examining such effects. The purpose of this study was to examine how ionizing radiation affects development in lake whitefish embryos and to investigate the presence...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR14574.1
更新日期:2017-10-01 00:00:00
abstract::The alveolar type II cell is one of the critical cells for radiation damage in the lungs after inhalation of radioactive aerosols. With the aid of a Quantimet-970 image analyzer and a VAX-11/780 computer, we calculated the radiation dose to rat alveolar type II cells from alpha particles emitted by 239PuO2. A series o...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1989-11-01 00:00:00
abstract::Infusions of boronophenylalanine-fructose complex (BPA-F), at doses up to 900 mg/kg of BPA and 860 mg/kg of fructose, have been used to deliver boron to cancer tissue for boron neutron capture therapy (BNCT). In patients with phenylketonuria (PKU), phenylalanine accumulates, which is harmful in the long run. PKU has b...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/rr3067
更新日期:2003-11-01 00:00:00
abstract::The nature of the primary biochemical defect in the human radiosensitive and cancer-prone syndrome, ataxia telangiectasia (AT), has remained obscure despite many efforts to elucidate it. In this study, AT complementation group D cells and a nearly isogenic corrected AT-hamster hybrid derivative have been analyzed for ...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1995-12-01 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