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Objective:To study the influence of circular RNA hsa_circZDHHC21_004 on the proliferation of human small intestinal epithelial cells HIEC-6 after 60Co γ-rays exposure. Methods:HIEC-6 cells were exposed to 60Co γ-rays at 0, 5, 10, and 15 Gy with a dose rate of 1 Gy/min. The expression level of hsa_circZDHHC21_004 in the irradiated HIEC-6 cell was detected. Hsa_circZDHHC21_004 was knocked-down to investigate the influences of hsa_circZDHHC21_004 on the proliferation of irradiated HIEC-6 cells by CCK-8 assay and colony formation assay. Results:The expression level of hsa_circZDHHC21_004 in HIEC-6 cells was upregulated by (1.00±0.24), (1.34±0.28), (1.85±0.31), and (2.80±0.64) times of control after 0, 5, 10, and 15 Gy irradiation, respectively and there were significant difference between 10 or 15 Gy group and 0 Gy group ( F=10.86, P=0.008). Knockdown of hsa_circZDHHC21_004 significantly increased the proliferation rate of HIEC-6 cells at 24, 48, and 72 h after 10 Gy irradiation compared with non-irradiated control ( t=-6.25, -5.83, -7.75, P < 0.001). Under 2 and 5 Gy irradiation, the clone formation rates of the hsa_circZDHHC21_004 knockdown cells were significantly higher than those of the control ( t=-7.45, -8.83, P<0.01). Conclusions:Hsa_circZDHHC21_004 is increased after irradiation and influenced the proliferation of irradiated HIEC-6 cells.
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The radiological health in China has been comprehensively progressing since The People′s Republic of China was founded. The outstanding achievement in radiological health field has been obtained, after lots of research work and practical applications have been completed. In order to provide the references and enlighten the ideas for domestic scientific institutes and colleagues in radiological health, this paper explicated the scientific questions and the bottleneck of techniques which needs to be explored in near future. The fields are including not only the protection and safety in occupational radiation, medical radiation, population radiation and emergency radiation, but also the radiation biological effects and its mechanism.
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Objective:To explore the characteristics of lipid metabolism in rat plasma after total body irradiation(TBI) in order to provide scientific evidence of radiation biomarkers.Methods:For the non-targeted lipidomics study, 50 SD rats were divided into 6 groups and irradiated with 0, 1, 2, 3, 5 or 8 Gy 60Co γ-rays, respectively. For the targeted lipidomics study, 25 rats were divided into 5 groups and irradiated with 0, 0.5, 2.5, 4 or 6 Gy. Venous blood samples were collected and plasma were separated 4 h after TBI. Radiation-sensitive lipids were screened and their concentrations were determined. Receiver operating characteristic curve (ROC) and dose-response were analyzed. Results:A total of 15 radiation differential lipids were screened out based on non-targeted lipidomics study and 7 of them were identified as radiosensitive lipids by targeted lipidomics analysis. The ROC of radiosensitive lipids distinguished area under curve (AUC) of samples in 0 Gy group and > 0 Gy group, < 2 Gy group and ≥ 2 Gy group were all > 0.75. The AUC values were increased to 0.96 and 0.94 after the panel of radiation sensitive lipids ROC analysis. The concentrations of LysoPC(18: 2), LysoPC(22: 0), PC(18: 0/18: 2), PE(18: 2/16: 0) and PE(18: 2/18: 0) decreased with irradiation dose within 0-6 Gy.Conclusions:A total of 7 plasma radiosensitive lipids in rat plasma were identified 4 h after TBI, and the panel of them could be used for specific dose classification. Five of the lipids had good dose-response relationship.
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Objective:To investigate the changes of CPT1A and CPT1B protein expression in rat intestinal epithelial cells (IEC-6) after 60Co γ-ray irradiation, and the mechanism of the influence of carnitine palmitoyltransferase 1 (CPT1) on the proliferation of irradiated IEC-6 cells. Methods:IEC-6 cells were cultured in serum-normal medium or in serum-starved medium overnight, and pretreated with 20 μmol/L palmitic acid (PA) before irradiation with 0, 5, 10, and 15 Gy. At 24 h after irradiation, the cellular protein was collected for the measurement of CPT1A and CPT1B proteins by Western blot. The influences of ETO, an inhibitor of CPT1, on the survival and proliferation of irradiated IEC-6 cells were analyzed by colony formation assay and CCK-8 assay. The protein expressions and phosphorylation levels of the extracellular signal-regulated kinase (ERK1/2) and c-Jun N-terminal kinase (JNK) in 5 Gy irradiated IEC-6 cells pre-treated with ETO were analyzed by Western blot at 48 h after radiation.Results:When IEC-6 cells were cultured in serum-normal medium together with PA, the protein level of CPT1A was significantly increased after 15 Gy irradiation ( t=-2.82, P<0.05). When IEC-6 cells were cultured in serum-starved medium, the protein level of CPT1A was significantly increased at 5, 10, and 15 Gy ( t=-3.28, -8.72, -8.67, P<0.05). When IEC-6 cells were cultured in serum-starved medium together with PA, the protein levels of CPT1A were significantly increased at 5, 10 and 15 Gy ( t=-10.69, -7.02, -8.23, P<0.05), the protein levels of CPT1B were significantly increased at 10 and 15 Gy ( t=-3.73, -5.05, P<0.05). After irradiation, the survival and proliferation of IEC-6 cells in ETO group were significantly lower than those in control group ( t=5.46, 13.22, P<0.05), and the protein level of ERK1/2 and p-JNK in ETO group were significantly lower than those in control group ( t=4.01, 3.29, 10.68, 14.44, P<0.05). Conclusions:CPT1 promoted radiation-induced IEC-6 injury cells survival and proliferation by enhancing the expression level of ERK1/2 protein and the activity of JNK.
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Objective:To explore the mechanism and regulatory effects of melatonin on UVB-induced melanin synthesis in human immortalized keratinocytes (HaCaT), so as to provide a theoretical basis for the skin protection of melatonin.Methods:HaCaT cells were pretreated with 10 -5 mol/L melatonin and then irradiated with 80 mJ/cm 2UVB. The melanin content was detected by NaOH assay, the proportion of premature senescence cells was detected by β-galactosidase staining kit, and the protein expression levels of both p53 and tyrosinase (TYR) were detected by Western blot at 72 h after UVB exposure. After 12 h pretreatment of ATM/ATR inhibitor, p53 inhibitor and melatonin, the proportion of premature senescence and the change of melanin content in HaCaT cells were detected at 72 h after 80 mJ/cm 2 UVB irradiation. Results:Melatonin inhibited UVB-induced increases of melanin content ( t=56.65, 13.39, P<0.05) and TYR expression ( t=16.46, P<0.05) in HaCaT cells. Melatonin alleviated UVB-induced premature senescence ( t=7.139, P<0.05) and inhibited UVB-induced increase of p53 expression ( t=19.08, P<0.05) in HaCaT cells. In addition, ATM/ATR inhibitor, p53 inhibitor and melatonin all inhibited UVB-induced increase of melanin content in HaCaT cells. Conclusions:Melatonin inhibits TYR-mediated melanin synthesis by regulating p53-related premature senescence in HaCaT cells after UVB irradiation.
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The application of chromosome translocation to retrospective biodosimetry for A-bomb survivors, the victims previously exposed to nuclear/ radiation accident has experienced nearly 40 years of development. Retrospective biodosimetry was internationally paid close attention to radiation workers, exposed atomic veterans and medical exposure subjects, respectively, along with the development of molecular cytogenetic technology such as mFISH and cGH. And the remarkable breakthrough and progress have been made in recent years. This paper reviews the progress of translocation indicator as retrospective biodosimetry for the subjects, in order to provide a reference for retrospective dose estimation based on translocation analysis.
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Objective:To explore the influence of dose-rate on radiation-induced gene expression in human peripheral blood.Methods:Human peripheral blood ex vivo was irradiated with 0, 1, 2, 4 and 6 Gy of 60Co γ-rays with different dose-rates of 0.2, 1 and 2 Gy/min. Human blood cells were harvested at 24 h post-irradiation. Following RNA isolation, the mRNA expression levels ofCDKN1A, MDM2, PCNA, FDXR, GADD45A, PHPT1, ASTN2, TNFSF4, POLH, GDF-15 and PPM1D were measured by quantitative real-time PCR. The stepwise regression method was used to establish the gene combination models. Results:The relative mRNA expression levels of 11 genes significantly increased in a dose-dependent manner within the dose range of 0-6 Gy with three dose-rates of irradiation ( R2=0.744-0.998, P< 0.05). Following the exposure to 2 Gy(0.2 Gy/min) 60Co γ-rays, the expression levels of CDKN1A, FDXR, PHPT1 and TNFSF4 genes were significantly higher than that of the 1 and 2 Gy/min groups ( t=3.73, 5.73, 2.44, 2.77, 3.53, 2.68, 2.43, 2.05, P< 0.05). With 6 Gy irradiation, the changes of radiation-induced PPM1D expression level under a dose rate of 2 Gy/min were significantly higher than other two dose-rates( t=3.82, 2.54, P< 0.05). The combined expression model at different dose rates was composed of 2-3 genes, and the R2values of regression equations were 0.976, 0.964 and 0.951, respectively. Conclusions:In a certain range, the dose-rate may affect the changes of radiation-induced gene expression in human peripheral blood.
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Objective:To investigate the metabolite changes in rat plasma after total body irradiation (TBI) and to explore dose classification based on radiation sensitive metabolites.Methods:The differential metabolites induced by radiation were screened and verified by metabolomics. In the discovery stage, 50 SD rats were irradiated with 0, 1, 2, 3, 5 and 8 Gy of 60Co γ-rays. In the verification stage, 25 rats were irradiated with 0, 0.5, 2.5, 4 and 6 Gy. Peripheral blood samples were collected 4 h after irradiation, and plasma was separated. Radiation-induced differential metabolites were identified and their concentrations were determined. Receiver operating characteristic (ROC) curve of the differential metabolites was used to classify dose range. Results:In the discovery stage, 8 radiation-induced differential metabolites in rat plasma were identified and four of them (cytosine, L-hexylcarnitine, Linoelaidylcarnitine and L-palmitylcarnitine) were upregulated, which was confirmed in the verification stage. The area under the curve (AUC) for the specific dose was >0.75. After combining these four metabolites, the AUC value to classify the radiation dose of 0 Gy versus >0 Gy, <2 Gy versus ≥2 Gy, <5 Gy versus ≥5 Gy were 0.96, 1 and 0.94, respectively.Conclusions:The metabolites in rat plasma changed significantly at 4 h after TBI, where 8 differential metabolites were identified. Cytosine, L-hexylcarnitine, linoelaidylcarnitine and L-palmiylcarnitine were stably over-expressed in the plasma after irradiation. The combination of these four compounds had high classification accuracy and thus may applicable as radiation sensitive biomarkers for dose classification.
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Proteomics was first proposed by Marc Wikins, et al in 1995. It refers to the investigation of all the proteins expressed in a set of genomes. With the development of mass spectrometry technology, it more and more extensively apply to the field of radiation. In particular, due to the widespread application of nuclear and radiation technologies has greatly increased, the probability of nuclear and radiation accidents, and the exposure of large-scale populations are increased. Therefore, simple, rapid, and high-throughput measurement of acute radiation exposure is necessary. The application of proteomics technology to study the molecular biological effects of radiation and the discovery of radiation biomarkers provide the possibility for rapid high-through put dose assessment. We reviewed the recent development of proteomics and its application in the field of radiation.
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Objective:To explore the feasibility of the optimized cytokinesis-block (CB) assay on radiation-induced nucleoplasmic bridge (NPB), and to provide a scientific basis for the application of NPB in biological dose estimation.Methods:Human peripheral blood in vitro was irradiated with 2 Gy 60Co γ-rays at a dose rate of 1 Gy/min (0 Gy control group). According to the culture time after irradiation, blood samples were divided into group 48, 56, 68 and 72 h. Cytochalasin-B (Cyt-B) with a concentration of 6 μg/ml was added into the samples at 28 h and harvested at 48, 56, 68 and 72 h after irradiation, respectively. On the other hand, the blood samples were treated with different concentration of Cyt-B i. e., 0.6, 1, 2, 6 and 10 μg/ml at the beginning of culture (0 h) and harvested at 68 h after irradiation. The proportion of mononucleated, binucleated and multinucleated cells, radiation-induced NPB and micronucleus (MN) frequencies were analyzed. Results:The nuclear division index (NDI) and proportion of binucleated cells at 2 Gy and 0 Gy had tendency of increasing with cell culture time. NPB frequencies (0.023 0-0.033 0/cell) and MN frequencies had no significantly difference ( P> 0.05). With the increase of Cyt-B concentration, NDI and the proportion of binucleated cells in group 2 Gy and 0 Gy also increased, but NPB frequencies (0.023 0-0.047 0/cell) had no significant difference ( P> 0.05). MN frequencies of group 10 μg/ml were significantly lower than that of group 6 μg/ml ( U=2.74, P< 0.01). Conclusions:Cell culture time and Cyt-B concentration had no significant influence on radiation-induced NPB frequencies, suggesting that NPB could be obtained by appropriately reducing cell culture time and Cyt-B could be added into blood samples at the beginning of culture. But this protocol reduced the number of cells for further analysis, and thus its feasibility for dose estimation still need to be studied.
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Objective:To screen radiosensitive lipid metabolites in rat small intestine and analyze their metabolic pathways, in order to provide scientific basis for radiation enteropathy biomarkers.Methods:The total body irradiation of 60Co γ rays was performed to rats with different doses of 0, 1, 2, 3, 5 and 8 Gy. The changes of lipids in small intestine were studied by targeted lipidomics method based on liquid chromatography coupled mass spectrometry (LC-MS). Results:Fifteen lipids in small intestine were screened as radiosensitive metabolites at 3 d after irradiation, including 4 up-regulated lipids and 11 down-regulated lipids( t=-6.395, 5.998, 5.836, -5.503, -5.449, -5.422, 4.841, 4.802, 4.621, 4.457, 4.426, 4.373, 4.110, 3.945, 3.902, P< 0.05 and FDR < 0.05). The metabolic pathways of sphingolipid, glycerophosphoplipid were significantly enriched. Four phosphatidyl serines (PS)increased while 1 phosphatidic acid(PA), 2 sphingomyelins(SM) and 4 fatty acids(FA)decreased in a good dose-response manner( R2> 0.80, P< 0.05), which were more potential radiation enteropathy biomarkers. Conclusions:Lipid metabolites in rat small intestine were significantly changed after the rat was total body irradiated with 60Co γ-rays.Eleven lipids with good dose-response relationship were more potential to be radiation enteropathy biomarkers.
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Objective:To explore the advantage of dose estimation based on semi-automated dicentric (dic) scoring and the feasibility of reflecting a large scale radiation accident for population clinical triage by mean of the comparison between semi-automatic and manual detection.Methods:Human peripheral blood samples from two healthy volunteers were irradiated by 60Co γ-rays at the doses of 0, 0.5, 1, 2, 3, 4, 5 and 6 Gy with a dose rate of 0.27 Gy/min, and chromosome preparation was carried out using the conventional method. The dic and dic plus ring were analyzed automatically with the DCScore software and manually with the Ikaros software, respectively, in a high-throughput chromosome automatic scanning system. The dose-response curves were fitted with dic or dic plus ring per cell. Twelve standard samples of biodosimetry were used to validate the dose-response curves. Results:The numbers of dic or dic plus ring per cell by semi-automatic or manual detection increased with the exposure doses ( r=0.984, 0.972, 0.972, P<0.01). The yields of semi-automated dic or manually detected dic plus ring were well fitted with the correlation coefficients ( R2=0.998, 0.999, 0.999, P<0.01). When the exposure dose of the standard samples was more than 2 Gy, the relative deviation between actual and predict doses was within 21% using the dose-response curve based on automated dic before human verification and correction of dic (elimination of false positives and inclusion of true positives), and wiht ±10% after manual elimination of false positive dic. Bio-doses estimated from the dic detected by manual scoring were similar to the actual exposure doses with the exception of 0.7 Gy, but the efficiency of semi-automatic analysis of dic was increased by 6-times in bio-dose assessment. Conclusions:The semi-automated dic detection obviously improves the level and efficiency of biodosimetry analysis, and thus can meet the requirements of clinical classification diagnosis of medical emergency response to large-scale nuclear radiation events.
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Objective:To screen radiosensitive lipid metabolites in rat plasma and analyze their metabolic pathways in order to provide scientific basis for radiation damage biomarker.Methods:The whole body irradiation of 60Co γ rays was performed to rats with different doses of 0, 1, 3 and 5 Gy. The changes of lipids in plasma were detected by untargeted lipidomics method based on liquid chromatography coupled mass spectrometry. Results:Twenty plasma lipids were identified as the potential radiosensitive biomarkers at 7 days after irradiation, including 13 over-expressed lipids and 7 down-expressed lipids, where 12 lipids well responded to radiation doses.Conclusions:Lipid metabolites in rat plasma are significantly changed after exposure to γ rays, and the metabolic pathways of sphingolipid, glycerophospholipid and glycosylphosphatidylinositol (GPI) are significantly enriched.
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Objective:To explore the influence factors of chromosomal aberration levels in radiation workers in hospitals.Methods:Two hundred and fourteen age- and sex- matched hospital radiation workers were recruited by stratified random sampling method. According to the job title, the individuals were divided into four groups including diagnostic radiology group ( n=57), radiotherapy group ( n=49), nuclear medicine group ( n=52) and interventional radiology group ( n=56). Chromosomal aberrations in peripheral blood lymphocytes from the subjects were measured using conventional cytogenetic analysis method, and the influence factors of chromosomal aberrations were analyzed. Results:There was significant difference in the frequencies of acentric fragment, translocation and total chromosome-type aberrations among the four groups ( χ2=9.906, 19.965, 32.824, P<0.05), and the rates of aberrations were significantly higher in the interventional radiology group and the nuclear medicine groups than those in the diagnostic radiology (interventional group: χ2=4.711, 10.798, 10.845, P<0.05; nuclear medicine group: χ2=3.853, 7.674, 7.708, P<0.05) and the radiotherapy groups (interventional group: χ2=9.209, 9.772, 21.330, P<0.05; nuclear medicine group: χ2=8.010, 6.969, 10.812, P<0.05). The rates of translocation and total aberrations ( χ2=7.706, 6.667, P<0.05) and the frequencies of acentric fragment, translocation and total aberrations ( χ2=12.263, 15.360, 21.478, P<0.01) were dependent on the length of service and the dose among different groups. The rates of translocation and total aberrations significantly increased along with exposure doses ( r=0.347, 0.263, P<0.01). Poisson regression analysis indicated that the job titles and annual effective dose partly affected the levels of chromosomal aberrations[ IRR=1.797 (nuclear medicine group), 2.136 (interventional group) and 1.422 (0.5-1 mSv group); P<0.05]. Conclusions:The frequencies of chromosomal aberrations in the radiation workers of interventional and nuclear medicine groups remain higher levels in hospital, thus it is necessary to strengthen the radiation protection on these radiation workers.
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Objective:To explore the effects of ultraviolet B (UVB) on the premature senescence of human immortalized keratinocytes HaCaT cells and the possible underlying molecular mechanism.Methods:HaCaT cells were exposed with UVB of different doses (20, 50, 80 and 100 mJ/cm 2). At 72 h after exposure, cellular morphology was observed by Giemsa staining, cell proliferation was detected by clone formation assay, and the proportion of premature senescence cells was detected by β-galactosidase staining. The number change of lysosomes was detected by Lyso-Tracker Red fluorescence probe at 24, 48 and 72 h after exposure. Cell migration was measured by scratch test at 24 h and 48 h after exposure. The protein expressions of p53 and p16 related to premature senescence were detected by Western blot assay at 72 h after exposure. Results:After UVB exposure, HaCaT cells showed a premature senescence phenotype. At 72 h after exposure, the cell volume increased ( F=115.18, P<0.05), the cell proliferation ability decreased ( F=410.32, P<0.05), the activity of β-galactosidase increased ( F=16.31, P<0.05), and the expressions of P53 and P16 increased. In addition, the number of lysosomes increased at 24, 48, and 72 h after exposure ( F=17.65, 38.36, 13.66, P<0.05), and cell migration capacity was inhibited at 24 and 48 h after exposure ( F=8.21, 11.48, P<0.05). Conclusions:UVB exposure can induce premature senescence of HaCaT cells by increasing the expression of p53 and p16 proteins.
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Objective:To investigate the feasibility of dose estimation based on the dose-response curves established by different types of dicentrics (dic).Methods:Human peripheral blood samples were irradiated by 60Co γ-rays at the doses of 0, 0.5, 1, 2, 3, 4, 5 and 6 Gy with the dose rate of 0.27 Gy/min, and chromosome preparation was carried out. The different types of dics were analyzed. The dose-response curves were fitted with software of Chromosomal Aberration Calculation Software (CABAS). Two samples were used to validate the dose-response curves. Results:The aberration rates of different types of dics increased with the exposure doses ( R2=0.886-0.943, P<0.01). The proportion of typical and single-ended dic components accounted for more than 92% of all types of dic, while the proportion of short-range dic and double-ended dic components was less than 4% at each dose point. The dose-response curves based on different types of dics were established ( R2=0.998, P<0.01). There was no significant difference in the doses estimated by four different dose-response curves ( P>0.05). The relative deviations between actual and predict doses were less than 13.08% by using dose-response curve based on typical dics. Conclusions:Dose-response curves based on different types of dics have the feasibility of dose estimation.
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Objective:To screen the indicators of retrospective dose estimation, based on 5 cytogenetic methods to assess the victim followed-up at 4 year after 192Ir radiation accident in Nanjing. Methods:The chromosome aberration (dic + r) assay, cytokinesis block micronucleus (MN) and nucleoplasmic bridge (NPB) assay, fluorescence in situ hybridization (FISH)-based and G banding-based translocation analysis were used to retrospective biological dose estimation. Results:The estimated doses of FISH-based and G banding -based analysis were 1.45 and 1.21 Gy respectively, which was similar to the biological dose estimated short time after the accident. However, the estimated doses by chromosome aberration, micronucleus and nucleoplasmic bridge method were 0.56, 0.45 and 0.41 Gy respectively, which were lower than the corresponding biodose. Correction factors were used to adjust the biodose.Conclusions:In the 4th years after exposure, the estimated biological doses by FISH-based and G banding-based translocation were consistent with the biodose.Therefore, the two methods were suitable for retrospective dose estimation, while correction factors should be considered in chromosome aberration method for retrospective dose estimation.
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Objective To study the effects of sex,age,length of service,type of work and annual effective radiation dose on nucleoplasmic bridge (NPB) in the peripheral blood lymphocytes of radiation workers.Methods The peripheral blood samples of 100 radiation workers in Henan province were collected and the NPB in peripheral blood lymphocytes were measured by CBMN assay.The frequencies of NPB formation and NPB-containing cells were calculated,and the effects of various factors on NPB incidence were analyzed statistically.Results The NPB frequency in radiation workers was higher than that in healthy people (Z=-8.123,P＜0.01).Except for sex,the factors of age,length of service,type of work and annual effective dose had significant influences on NPB (x2=7.202-45.571,P＜0.05).Conclusions NPB reflects the effect of low-dose long-term chronic irradiation on the occupational radiation workers.
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Objective@#To study the effects of sex, age, length of service, type of work and annual effective radiation dose on nucleoplasmic bridge (NPB) in the peripheral blood lymphocytes of radiation workers.@*Methods@#The peripheral blood samples of 100 radiation workers in Henan province were collected and the NPB in peripheral blood lymphocytes were measured by CBMN assay. The frequencies of NPB formation and NPB-containing cells were calculated, and the effects of various factors on NPB incidence were analyzed statistically.@*Results@#The NPB frequency in radiation workers was higher than that in healthy people (Z=-8.123, P<0.01). Except for sex, the factors of age, length of service, type of work and annual effective dose had significant influences on NPB (χ2= 7.202-45.571, P<0.05).@*Conclusions@#NPB reflects the effect of low-dose long-term chronic irradiation on the occupational radiation workers.
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OBJECTIVE: To explore the dose-effect of X-ray irradiation and chromosome aberrations in human peripheral blood cells,and establish a dose-response curve of dicentric and ring(dic+r)aberration induced by X-ray irradiation.METHODS: Human peripheral blood samples were collected from three healthy individuals and were exposed to X-ray at the doses of 0.00,0.25,0.50,0.75,1.00,2.00,3.00,4.00 and 5.00 Gy in vitro.The dose rate was 1.158 Gy/min.The blood cells were harvested after routine culture,and the chromosome preparation was carried out.The dicentrics and rings in metaphase cells were counted under microscope,and a dose-response curve was fitted by using the software of CABAS.Dose estimation was performed according to the curve from two blind samples.RESULTS: Aberration of dic+r increased with irradiation doses in the range of 0.00-5.00 Gy(P<0.01).The dose-response relationship followed a linear-quadratic equation:■,where■ is the yield of dic+r,and D is the irradiated dose.The estimated doses of the two blind samples were in accordance with the actual doses.CONCLUSION: The dose-response curve and mathematical model of chromosome aberration following exposure to 0.00-5.00 Gy X-ray irradiation is established in this study provide a reliable method for the accurate dose estimation.