Abstract:
:We used a cell sorter assay to evaluate the efficacy of the hypoxic cell sensitizer etanidazole over 3-4 logs of cell inactivation, with particular attention to the clinically relevant low-dose survival region. Analysis of the radiation responses in a panel of six human tumour cell lines under conditions of hypoxia and hypoxia with etanidazole revealed both a cell-line and radiation dose-dependence in the sensitizing ability of this drug. Fits of the linear-quadratic (LQ) model to the low-dose region of cell survival indicate that sensitization of hypoxic cells by etanidazole results primarily from a modification of the beta parameter. This results in selective sensitization of cell lines in which this parameter contributes significantly to cell kill (i.e. a low alpha/beta ratio) and implies that the efficacy of this drug may be tumour specific. Selective modification of beta also leads to a radiation dose-dependence of the sensitizing enhancement ratio (SER). Analysis of the alpha and beta parameters derived from fist to data at low doses of radiation, suggests that the dose-dependence of this sensitizer, and possibly others including oxygen, is cell-line dependent; cell lines exhibiting a low alpha/beta ratio (i.e. with a large shoulder) exhibit little or no SER dose dependence, while those with a high alpha/beta ratio (i.e. small shoulder) exhibit a reduced SER at low doses as compared to high doses. Furthermore, this analysis suggests that modelling of the low-dose radiation survival data under conditions of hypoxia, can be predictive for both the absolute sensitizing ability of etanidazole, and its dose dependence. Our results also indicate that measurement of the in vitro low-dose radiation survival response in a panel of human cell lines is a more effective assay for evaluating agents like etanidazole than simply high-dose measurements in rodent cell lines which have, in general, demonstrated more congruent survival responses.
journal_name
Int J Radiat Bioljournal_title
International journal of radiation biologyauthors
Wouters BG,Sy AM,Skarsgard LDdoi
10.1080/095530096144617subject
Has Abstractpub_date
1996-12-01 00:00:00pages
719-33issue
6eissn
0955-3002issn
1362-3095journal_volume
70pub_type
杂志文章abstract:PURPOSE:To present details of the recent version of the 'Local Effect Model' (LEM), that has been developed and implemented in treatment planning for the ion beam therapy pilot project performed at GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany. MATERIALS AND METHODS:The new version of the model i...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.3109/09553002.2011.611213
更新日期:2012-01-01 00:00:00
abstract::Single crystals of cytosine hydrochloride with thiocytosine as an impurity were found suitable for the study of a possible new mechanism of long-range migration of energy deposited by ionizing radiation. In a crystal containing thiocytosine, two kinds of chlorine-containing paramagnetic centres are present that are co...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.1080/09553009414550891
更新日期:1994-07-01 00:00:00
abstract::A study has been made of the intrinsic radiosensitivity of peripheral blood lymphocytes from normal individuals. Cell survival following in vitro high (1.55 Gy min-1) and low (0.0098 Gy min-1) dose-rate irradiation was obtained for single lymphocyte samples from three individuals in six experiments. Despite wide inter...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.1080/09553009314551571
更新日期:1993-10-01 00:00:00
abstract:PURPOSE:The aim of this research was to demonstrate the effects of 50 Hz sinusoidal extremely low frequency of magnetic fields (ELF-MF) on preincubated chicken embryo hearts at histopathological, biochemical, and ultrastructural levels. MATERIALS AND METHODS:Ninety healthy fertilized eggs were divided into six groups ...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.3109/09553002.2013.754556
更新日期:2013-04-01 00:00:00
abstract:PURPOSE:The purpose of this study was to determine whether the effects of gamma rays on the regeneration of hair follicles are carried over to later hair cycles. MATERIALS AND METHODS:The whole bodies of C57BL/10JHir mice in the 1st telogen phase were irradiated with (60)Co γ-rays. Mice were examined for the effects o...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.3109/09553002.2015.1101647
更新日期:2015-01-01 00:00:00
abstract:PURPOSE:To analyze the role of mus-genes repair in system activation P-elements in Drosophila melanogaster induced by a chronic exposure to low doses. MATERIALS AND METHODS:The materials were dysgenic individuals of Drosophila melanogaster with mutations in repair genes (mus101, mus205, mus304, mus308, mus309) and sim...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.1080/09553002.2016.1206221
更新日期:2016-09-01 00:00:00
abstract:PURPOSE:The prolonged delivery times associated with intensity modulated radiation therapy (IMRT) may reduce treatment effectiveness of radiation therapy for cancers with short repair half-times. In this study, in vitro radiation experiments with DU-145 prostate cancer cells were designed to quantify the half-time of s...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.1080/09553000802061285
更新日期:2008-06-01 00:00:00
abstract:PURPOSE:To examine the relationship between cell killing and residual chromatin breaks after irradiation with qualitatively different types of radiation in six human cell lines. MATERIALS AND METHODS:Six human tumour cell lines and normal human cells were irradiated with 200 kV X-rays and two carbon-ion beams accelera...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.1080/09553000050134429
更新日期:2000-09-01 00:00:00
abstract:PURPOSE:Detection of gene targets applicable to biological dosimetry and early detection of radiation-induced cell damage. MATERIALS AND METHODS:MCF-7 human mammary carcinoma cells were exposed to 2 and 6 Gy X-rays. Expression of 1176 genes was traced with the Atlas Human 1.2 Array (Clontech). RESULTS:(1) Based on da...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.1080/0955300032000093146
更新日期:2003-05-01 00:00:00
abstract:PURPOSE:The linear nonthreshold (LNT) model has been used in radiation protection for over 40 years and has been hotly debated. It relies heavily on human epidemiology, with support from radiobiology. The scientific underpinnings include NCRP Report No. 136 ('Evaluation of the Linear-Nonthreshold Dose-Response Model fo...
journal_title:International journal of radiation biology
pub_type: 杂志文章,评审
doi:10.1080/09553002.2017.1328750
更新日期:2017-10-01 00:00:00
abstract:PURPOSE:It is considered that exposure to static magnetic fields (SMF) may have both detrimental and therapeutic effect, but the mechanism of SMF influence on the living organisms is not well understood. Since the adenosine triphosphatases (ATPases) and acetylcholinesterase (AChE) are involved in both physiological and...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.1080/09553002.2018.1518611
更新日期:2018-11-01 00:00:00
abstract::Pre-implantation embryos of the mouse were studied for the occurrence of an adaptive response, i.e. induction of radio-resistance by a previous low dose. Various experimental designs were checked (initial doses between 3 and 10 cGy; second dose 2-6 Gy at 6-24 h after the first dose). Some of the experiments were carri...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.1080/09553009214551981
更新日期:1992-08-01 00:00:00
abstract::A radionuclide release assay for measuring the in vitro kinetics of cell death has been developed. CHO cells were labelled for 24 h with 3.0 hBq/ml of [125I] iododeoxyuridine (125IUdR) and the fate of the labelled cells and their progeny was monitored at daily intervals by measuring the rate of 125I release. Prelabell...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.1080/09553009114550361
更新日期:1991-02-01 00:00:00
abstract:PURPOSE:The nature of the transferrable factor which goes from irradiated objects to bystander objects remains undefined. Most agree that a chemical entity is the likely 'factor' although some authors have produced in vitro evidence for the involvement of a physical component or a very potent volatile capable of travel...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.3109/09553002.2012.698366
更新日期:2012-08-01 00:00:00
abstract:PURPOSE:Many strategies have been investigated to exclude the several side-effects of pharmacological or invasive treatments. Non-invasive pulsed magnetic field (PMF) treatment with no toxicity or side-effects can be an alternative to pharmacologic treatments. The purpose of this study was, therefore, to investigate th...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.3109/09553002.2013.835501
更新日期:2014-01-01 00:00:00
abstract:PURPOSE:To construct a quantitative model of the radiation-induced bystander effect based on diffusion-type spreading of bystander signal communication between the hit and non-hit cells. Cell inactivation and induced oncogenic transformation by broad- and microbeam irradiation systems are considered. MATERIALS AND MET...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:
更新日期:2003-01-01 00:00:00
abstract::Cells use substrates such as glucose and glutamine to provide energy for repair of radiation damage. Glutaminolysis and glycolysis were inhibited by aminooxyacetic acid (AOAA) and 2-deoxyglucose (2DG), respectively, to inhibit metabolism of these substrates in order to determine the effect on radiation response of CHO...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.1080/095530098142419
更新日期:1998-03-01 00:00:00
abstract:PURPOSE:Radiotherapy of cancer carries a perceived risk of inducing secondary cancer and other damage due to dose delivered to normal tissue. While expectedly small, this risk must be carefully analysed for all modalities. Especially in the use of exotic particles like pions and antiprotons, which annihilate and produc...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.3109/09553000903242081
更新日期:2009-12-01 00:00:00
abstract::CHEF-electrophoresis was used as a technique to detect radiation-induced DNA breakage with special emphasis to biological relevant X-ray doses (0-10 Gy). Fluorescence detection of DNA-fragments using a sensitive image analysis system was directly compared with conventional scintillation counting of 3H-thymidine prelab...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.1080/09553009314551361
更新日期:1993-08-01 00:00:00
abstract::We have compared the repair kinetics of X-ray-induced sublethal damage (SLD) and potentially lethal damage (PLD) in V79 cells during postirradiation incubation in growth medium at 37 degrees C. Kinetics of SLD repair were studied by dose fractionation (D1 + D2 = 2 + 2, 4 + 2, 4 + 4, 10 + 4 and 10 + 7 Gy). Kinetics of ...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.1080/09553008914551411
更新日期:1989-09-01 00:00:00
abstract:PURPOSE:To study the oxidative stress-induced changes by sublethal doses of cadmium chloride (CdCl2) and gamma irradiation, two redox-inducing agents, on metallothionein (MT) gene and protein expression in Plantago ovata Forsk (P. ovata). MATERIALS AND METHODS:Chlorophyll content was estimated to study the stress resp...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.3109/09553002.2013.782109
更新日期:2013-07-01 00:00:00
abstract:PURPOSE:This review is a contribution to the memory of Dr William (Bill) Morgan and highlights an area of research and deliberation that he considered extremely important in support of the setting of protective radiation dose limits. Biological research has generally played a minor role in the estimation of adverse hea...
journal_title:International journal of radiation biology
pub_type: 杂志文章,评审
doi:10.1080/09553002.2017.1290848
更新日期:2017-10-01 00:00:00
abstract:PURPOSE:One of the most important issues regarding radiofrequency electromagnetic fields (RF-EMF) is their effect on genetic material. Therefore, we investigated the cytogenotoxic effects of 900 MHz radiofrequency electromagnetic fields (RF-EMF) and the effect of a recovery period after exposure to RF-EMF on bone marro...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.3109/09553002.2013.809170
更新日期:2013-11-01 00:00:00
abstract::The radiosensitization of two human tumour in vitro cell lines, HT-1080 and LoVo, has been compared with that of the Chinese hamster cell line V79-379A. Although the two human tumour cell lines were more radiosensitive than the V79 cell line sensitizer, enhancement ratios for misonidazole, pimonidazole and azomycin we...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.1080/09553009014552461
更新日期:1990-02-01 00:00:00
abstract:PURPOSE:Dose response and repair kinetics of phosphorylated histone H2A isoform X (gamma-H2AX) foci in T-lymphocytes were investigated in the low-dose range after in vitro irradiation of whole blood and T-lymphocytes with 100 kVp X-rays and (60)Co gamma-rays. MATERIALS AND METHODS:Whole blood or isolated T-lymphocytes...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.3109/09553002.2010.484479
更新日期:2010-09-01 00:00:00
abstract::Purpose To investigate the effect of increasing the overall treatment time as well as delivering the compensating doses on the Balb/c breast adenocarcinoma (4T1) tumor. Materials and methods A total of 72 mice were divided into two aliquots (classes A and B) based on the initial size of their induced tumor. Each class...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.3109/09553002.2016.1117677
更新日期:2016-01-01 00:00:00
abstract:PURPOSE:Caffeine (1,3,7-trimethyl xanthine), a dietary component, has been shown to have widely varying effects on DNA damage induced by UV and ionizing radiation, depending upon pre- or post-irradiation administration and its concentration. Caffeine administered post-UV irradiation is known to inhibit enzymatic repair...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.1080/09553000110034649
更新日期:2001-05-01 00:00:00
abstract::We have measured clonal survival following gamma-irradiation of unstimulated (G0) T-lymphocytes from 35 donors, of 11 T-lymphocyte cell lines, of six lymphoblastoid cell lines, and of nine primary fibroblast strains for which we have G0 T-lymphocyte material from the same donor. Amongst the G0 lymphocytes we have resu...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.1080/09553008814552331
更新日期:1988-12-01 00:00:00
abstract::Cell cultures derived from skin biopsies of mouse fetuses X-irradiated at the zygote stage (2 Gy) were studied for the presence of chromosomal aberrations and micronuclei. In comparison with cells from control, unirradiated fetuses significantly higher spontaneous frequencies of aberrations per 100 metaphases and aber...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.1080/09553008914550091
更新日期:1989-01-01 00:00:00
abstract:PURPOSE:To ask whether highly metastatic sublines show more marked low-dose hyper-radiosensitivity (HRS) response than poorly metastatic ones. MATERIALS AND METHODS:The progressive (PRO) subline showing tumourigenicity and metastatic potential and the regressive (REG) subline showing neither tumourigenicity nor metast...
journal_title:International journal of radiation biology
pub_type: 杂志文章
doi:10.1080/09553000802195331
更新日期:2008-07-01 00:00:00