Objective To investigate the effect of CDT1 gene over-expression on the apoptosis and cell cycle distribution in liver cells with a characteristic of genomic instability induced by radiation(GIR).Methods Lentivirus particles were transferred into liver cells of GIR to up-regulate the expression of CDT1 gene.The apoptosis and the cell cycle were detected by flow cytometry (FCM).The expression changes of p53,ATM,ATR,Bcl-2,and Caspase-3 genes were analyzed by real-time fluorescence quantitative PCR.Results CDT1 gene was efficiently increased by the gene transfection(t =15.56,P ＜ 0.05).In the CDT1 over-expressed cells,while the apoptosis ratio was increased (t =4.19,P ＜ 0.05),the expressions of p53 and Bcl-2 gene were decreased (t =-4.21,-2.06,P ＜ 0.05),but the expression of ATM,ATR and Caspase-3 changed with no significant difference compared with control.Conclusions Over-expression of CDT1 could regulate genomic instability through apoptosis pathway and checkpoint independent of p53.

Objective To investigate the differential expression profile in the progeny of human liver cells surviving from ionizing radiation.Methods Complemental DNA gene chip was used to measure the transcriptional profile in progeny of HL-7702 cells exposed to 0, 2, 4, and 6 Gy of 60Co γ-rays, and the differentially expressed genes HAVCR2 and RAN were further identified by real-time PCR.Results The transcription level of 262 genes, 2746 genes and 3406 genes changed in the progeny of survival cells at 2, 4 and 6 Gy, respectively.A total of 71 common differentially expressed genes were screened, most of which were associated with transduction, cell cycle regulation, cellular immunity, cytoskeleton and movement, cell replication and repair mechanism.Conclusions Ionizing radiation could induce the expression changes of many genes, which might reveal the molecular mechanisms of gene expression in radiation induced genomic instability.

Objective To investigate the changes of proteomics in serum of Sprague-Dawley(SD) rats after accumulated irradiation with 137Cs γ-rays.Methods A total of thirty mature SD rats were randomly divided into three groups:0.2 Gy group,2 Gy group and healthy control group.Rats were irradiated at a dose rate of 0.336 mGy/min for 10 d and 20 d continuously.Isobaric tags for relative and absolute quantitation (iTRAQ) was used to analyze the different protein expression in serum of irradiated rats.Gene Ontology,KEGG pathway and protein-protein interaction network analysis were conducted using softwares.Results In total,363 protein spots were identified.Twenty nine proteins were differentially expressed in both groups compared with control,of which 10 proteins were up-regulated and 19 proteins were down-regulated.Based on the information of GO categories,these differentially expressed proteins were mainly located in the cytoplasm and membrane concerning the function of binding and catalytic activity.Analysis with the PAJEK software demonstrated that 16 differentially expressed proteins could form a complicated interaction network where glutathione S-transferase P1 (GSTP1),phosphoglycerate kinase 1 (PGK1) and protein disulfide-isomerase (PDI) might be key nodes.Conclusions Accumulated irradiation can induce differentially expressed proteins in serum of irradiated rats.Analysis on functional roles of the screened proteins GSTP1,PGK1 and PDI may provide insight into further mechanistic investigations and underlying molecular biomarkers induced by accumulated irradiation.

Objective To explore the effects of HAVCR2 siRNA on apoptosis and cell cycle in the radiation-caused genomic instable liver cells.Methods RNAi was used to inhibit HAVCR2 gene transcription.Cellular apoptosis and cell cycle distribution were detected by flow cytometry (FCM).Expression of p53 gene was assayed by real time fluorescence quantitative PCR.Results HAVCR2 gene was effectively inhibited by RNAi (t =19.21,P ＜ 0.05).After siRNA transferring,cell apoptosis (t =3.65,P ＜ 0.05) and p53 gene expression (t =4.82,P ＜ 0.05) were decreased,and G2-phase arrest was induced(t =-3.41,P ＜ 0.05).Conclusion HAVCR2 siRNA can decrease the generation of apoptosis in the genomic instable liver cells and blocks the cells at G2 phase.

Objective To explore the effects of accumulated 60CD,γ-ray irradiation on small molecular metabolites in rats urine.Methods Ten healthy male SD rats were irradiated by 60Co γ-rays in 5 days and the accumulated doses were 0,0.2,0.4,0.6,0.8,1.0 Gy,respectively.The metabolites in urine of different groups were measured with 1 H-NMR combined with principal components analysis (PCA) and partial least square discriminate analysis (PLS-DA). Results The metabolites in rat urine were obviously changed after irradiation. Compared with control group,the amount of acetoacetate decreased after irradiation(t =29.7 -30.7,P ＜ 0.05 ),but its relative level was stable when the dose increased ( P ＞ 0.05 ).Meanwhile,the relative level of hippuric acid increased ( t =4.4 - 21.6,P ＜ 0.05 ) especially when the accumulated dose was higher than 1 Gy (t =21.6,P＜0.05). The relative level of proline,taurine and trimethylamine-N-oxide increased after irradiation with the same trend( t =3.5 - 13.4,4.7 - 11.5,2.9- 12.7,P＜0.05). Conclusions The acetoacetate,hippuric acid,proline,taurine,and trimethylamine-N-oxide may be applicable for biomarkers of accumulative irradiation on rat.

Radiation sterilization is one of the most successful applications of ionizing radiation technologies. This paper reviews research on virus inactivation by ionizing radiation, focusing on its use in virus control for food, blood products, and homologous or heterologous tissue repair materials, inactivated viral vaccine preparation, and high-risk virus-related laboratory sample preparation, and also puts forward some thoughts on the application of ionizing radiation technologies in the prevention and control of coronavirus disease 2019.

This paper summarizes and discusses the research and achievements in the effect of irradiation on extending the shelf life and quality guarantee period of seafood, on the quality of seafood, and on seafood sterilization, and seafood irradiation biological dosimeter study, and defines the concepts related to seafood irradiation. Moreover, we propose that irradiation sterilization on severe acute respiratory syndrome coronavirus 2 of cold-chain seafood and seafood irradiation dose control are the main research content and directions.

Health monitoring of radiation workers is an important part of the radiation protection system. Occupational health examination is very important for the safe use of nuclear energy technology. This article analyzes the detection results of radiation-sensitive indicators reported in the literature to investigate the health status of radiation workers and to provide a reference for the further study of sensitive indicators in health monitoring of radiation workers.

A large number of people would be exposed to irradiation in large-scale nuclear and radiation accidents or nuclear terrorist attacks. Therefore, it is urgent to establish rapid and high-throughput biodosimetry for in triage, providing a basis for emergency management. Imaging flow cytometry (IFC) possesses the high through put advantages of traditional flow cytometry and the sensitivity and specificity of microscope, and has a good application prospect in the research and development of rapid, automated, and high-throughput biological dose estimation technology. This article reviews the application progress of IFC in biodosimetry, and provides a reference for the development of biological dose estimation and detection equipment for large-scale nuclear and radiation accidents.

Objective To analyze the micronucleus levels of peripheral blood lymphocytes of medical radiation workers, and to provide a basis for radiation protection to reduce occupational hazards caused by ionizing radiation. Methods A total of 1072 medical radiation workers were selected into radiation group, and 329 healthy adults who underwent pre-employment occupational physical examination and intended to be radiation workers were selected into control group. The micronucleated lymphocyte frequency was determined by whole blood micro-culture. Results There were no significant differences in micronucleated cell frequency and micronucleus frequency between the radiation group and the control group (both P > 0.05). The detection rate of micronucleus abnormalities in the radiation group was significantly higher than that in the control group (P < 0.001). Female radiation workers had significantly higher micronucleated cell frequency, micronucleus frequency, and the detection rate of micronucleus abnormalities than male radiation workers (all P < 0.001). Between different types of work, significant differences were observed in micronucleated cell frequency and micronucleus frequency (both P < 0.05), but not in the detection rate of micronucleus abnormalities (P > 0.05). Radiation workers with different lengths of working showed significant differences in micronucleated cell frequency (P < 0.05), micronucleus frequency (P < 0.05), and the detection rate of micronucleus abnormalities (P < 0.001). Significant differences were observed in micronucleated cell frequency and micronucleus frequency between different age groups (both P < 0.05). The Spearman’s rank correlation analysis showed that micronucleated cell frequency and micronucleus frequency were positively correlated with the age of radiation workers (both P < 0.001). Conclusion The micronucleus frequency of radiation workers was related to the type and length of work, and had a positive correlation with age. Radiation protection should be enhanced for workers engaged in medical radiation for a long period, especially female workers and workers with a long length of service.