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.

Objective To investigate a potential radiation biodosimetry based on multiple gene expressions.Methods Human peripheral blood were exposed to 60Co γ-rays at doses from 0 to 8 Gy.The mRNA expression levels of 10 selected genes were detected 6 and 12 h after irradiation by RT-PCR.Individual variation was also examined.An optimal mathematical model of the dose response of these gene expression levels at each time point was obtained by the stepwise regression method.A blind test was conducted to validate the statistical accuracy of dose estimation.Results The 10 selected genes expression levels at each time point were significantly increased along with dose from 0.5 to 8 Gy (R2 =0.61-0.97,P ＜ 0.05).Individual variations were evident in the gene expressions of TNFSF4,PHPT1 and FDXR.The gene expression levels of PCNA,CCNG1,TNFSF4,PHPT1,GADD45A and FDXR were incorporated into the model at 6 h after exposure (R2 =0.88,F =54.8,P ＜ 0.001);the gene expression levels of PCNA,CCNG1,TNFSF4,MDM2,GDF15 and TNFRSF10B were included in the model at 12 h after irradiation (R2 =0.82,F =42.767,P ＜ 0.001).These two statistical models can be utilized for the dose estimation accurately.Conclusions The multiple gene expressions have a potential as a radiation biodosimetry.

Objective To explore the influences of the final concentration and adding time of Cytochalasin-B (Cyt-B) on radiation-induced nucleoplasmic bridges (NPB) in cytokinesis-block assay.Methods Hunan peripheral blood samples were divided into 5 final concentration groups (group 2,4,6,8,10 μg/ml) according to different final concentrations of Cyt-B.Moreover,blood samples were divided into 4 adding time groups (group 0,28,40,44 h) according to different adding times of Cyt-B.Blood samples were irradiated with 0 (sham irradiation) and 2 Gy 60Co-rays in vitro,at a dose rate of 1 Gy/min.A cytokinesis-block assay was carried out to prepare NPB samples.The percentages of mononucleated,binucleated and multinucleated cells,as well as the frequencies of NPB and micronucleus (MN) in binucleated cells were analyzed using an optical microscope.Results Nuclear division index (NDI) and the percentages of binucleated cells increased with increased concentration of Cyt-B,and decreased with delayed adding time of Cyt-B (except group 0 h) in both final concentration groups and adding time groups.After exposed to 2 Gy,NPB frequencies were no significant difference (except group 0 h).MN frequencies had the trend of decreased with the increased concentration of Cyt-B,but no significant difference with adding time of Cyt-B.Conclusions In cytokinesis-block assay,different final concentration and adding time of Cyt-B may induce to the variation of NPB frequencies,but there was no significant difference.Appropriate increased final concentration or ahead adding time of Cyt-B can increase the percentage of binucleated cells that help to improve the efficiency of analysis.

Objective To explore whether a low dose of 60Co γ-rays could induce the adaptive response in the formation of nucleoplasmic bridges (NPB) in human peripheral blood lymphocytes,and if so,the range of the priming dose.Methods Human peripheral blood samples from healthy males were collected and irradiated with 0,20,50,75,100,150 and 200 mGy (dose-rate was 25 mGy/min) of 60Co γ-rays.After 6 h,the samples were irradiated with a challenge dose of 2 Gy (dose-rate was 1 Gy/min).The cytokinesis-block micronucleus (CBMN) assay was carried out to analyze the NPB and micronuclei (MN) formation in binucleated cells.Results Within the dose range of 0-200 mGy,the yields of NPB and MN increased with irradiation dose of γ-rays and the dose response of NPB followed with a linearquadratic equation of y =(1.5 × 10-4) x2-(5.67 × 10-3)x + 0.598 (R2 =0.893 8).Compared with the samples irradiated with 2 Gy alone,the yields of NPB and MN were significantly reduced when the samples were irradiated with a priming dose of 75-100 mGy before 2 Gy irradiation (U =2.66,2.97,3.96,5.89,P ＜0.05).The biggest decrease ratio of NPB yields approached to 43.2％ at the priming dose of 100 mGy.Conclusions Low doses in the range of 75-100 mGy of 60Co γ-rays could induce the adaptive response of NPB formation in human peripheral blood lymphocytes.

Objective To investigate the dose response of S100A4 gene expression in the irradiated lymphoblastoid cells AHH-1 at different time points post irradiation.Methods AHH-1 cells was exposed to different doses(0,1,3,5,8,10,15 and 18 Gy)of 60Co γ-rays,and its mRNA levels of S100A4 was detected by reverse transcription PCR and real-time PCR at 4,8,12,24,48 and 72 h after irradiation.Results Within the range of applied doses,the level of S100A4 gene expression was upregulated with a good dose-response (R2 =0.79-0.93,P ＜ 0.05) and had obvious difference at different time points (F =8.91,P ＜ 0.01).Conclusion S100A4 gene expression at transcriptional level could be detected easily and had optimum dose-responses at certain time points after irradiation,and hence is applicable as a dosimeter.

Objective To investigate the effect of radiation on the mitochondrion in adenocarcinoma A549 cells.Methods After A549 cells were irradiated with 0,0.5,3 or 8 Gy of 60Co γrays,mitochondrion membrane potential of A549 cells was detected by JC-1 probe,and ATP activity was measured by ATP kit in a chemiluminescence apparatus.The mitochondria DNA copy numbers was detected by real-time PCR assay.Results At 24 h after radiation,the mitochondrion membrane potential of A549 cells in all the irradiated groups changed significantly (F =243.44,P ＜ 0.05),among which 0.5 or 3 Gy of radiation resulted in a significant increase of mitochondrion membrane potential of A549 cells (t =-10.12,-5.59,P ＜ 0.05).However,the mitochondrion membrane potential of A549 cells exposed to 8 Gy of radiation decreased significantly 24 h after radiation (t =15.22,P ＜ 0.05).The mitochondrion membrane potential of A549 cells in all radiation groups returned to the normal level 48 h after radiation (F =10.36,P ＜ 0.05).24 h after radiation,the level of ATP in A549 cells significantly changed respectively(F =97.08,P ＜ 0.05),similar to the mitochondrion membrane potential.The ATP level in 0.5 and 3 Gy groups increased significantly (t =1.66,7.27,P ＜ 0.05),and the level of ATP in 8 Gy group decreased significantly (t =-8.24,P ＜ 0.05).Furthermore,48 h after both 0.5 and 3 Gy of radiation,the ATP content in A549 cells was still higher than that in untreated A549 cells (t =4.60,8.53,P ＜0.05).The mitochondria DNA copy numbers in A549 cells increased significantly in all the radiation groups (F =118.00,P ＜ 0.05).Compared with untreated A549 cells the mitochondria DNA copy numbers in A549 cells increased at 0.5 Gy by 12 times(t =0.02,P ＜0.05),and increased at 3 and 8 Gy by 7 and 10 times,respectively (t =9.68,15.10,P ＜ 0.05).Conclusions High dose of radiation resulted in the decrease of mitochondrion membrane potential of A549 cells,which subsequently affected the production of ATP.However,radiation with moderate and lower dose could lead to the compensatory increase of mitochondrion membrane potential of A549 cells,which promoted the production of ATP.The mitochondria DNA copy numbers compensatory would increase after A549 cells were exposed to radiation within 8 Gy.

Objective For developing safe and effective anti-radiation new drugs,the effects of different lipoic acid amino acid salts on radiosensitivity were investigated.Methods The free radical scavenging ability of the above salts was evaluated in Fenton system.CCK-8 assay and flow cytometry assay were performed to evaluate the survival rate of L02 and apoptosis of AHH-1 after γ-ray irradiation,respectively.Results The lipoic acid arginine salt had the best ability of scavenging free radicals in Fenton system with an IC50 of 8.40 μ moL/ml.The survival assay showed that lipoic acid amino acid salts had better stability and equal ability in radioprotection (P ＞ 0.05) compared with lipoic acid.The apoptosis assay indicated that all lipoic acid amino acid salts could inhibit radiation-induced apoptosis,where lipoic acid arginine salt was more effective (t =-6.67,P ＜ 0.01).Conclusions Lipoic acid arginine salt has good radioprotection effect on L02 and AHH-1 cells by scavenging free radicals.

Objective To evaluate long-term outcome of simultaneous kissing sirolimus-eluting stent (SKS) technique versus single sirolimus-eluting stent (SSS) technique for percutaneous treatment of true coronary bifurcation lesions in large-size vessels.Methods This randomized study assigned 190 patients with a coronary bifurcation lesion to simultaneous kissing stenting (SKS) in both main and side branches and 190 patients to main vessel stenting only (SSS).The endpoints included restenosis,death,non-fatal myocardial infarction,target-lesion revascularization (TLR),stent thrombosis,success rate of percutaneous coronary intervention (PCI) and the operation duration.Results During 1-year follow-up,the SKS group and the SSS group had similar incidences of overall re stenosis [30 ( 15.8 ％ ) vs.24 ( 15.2 ％ ),x2=0.000,P＜0.05],mainbranch restenosis [20 ( 10.5％ ) vs.16 ( 10.1％ ),x2=0.003,P ＞ 0.05];side-branch restenosis [13 ( 6.8％ )vs.23 ( 14.6％ );x2=4.73,P＜0.05];death [2 ( 1.1％ ) vs.1 ( 0.6％ ),x2=0.026,P ＞ 0.05],non-fatal myocardial infarction [4 (2.1％ ) vs.2 ( 1.3％ ),x2=0.034,P ＞ 0.05],TLR [23 ( 12.1％ ) vs.20 ( 12.7％ ),x2=0.000,P ＞ 0.05] and stent thrombosis [4 (2.1％ ) vs.2 ( 1.3 ％ ),x2=0.034,P ＞ 0.05] and a shorter operation duration[(20 ± 8) min vs.(45 ± 9) min,t=1.98,P＜0.05] than the SSS group.Conclusion For true coronary bifurcation lesions in large-size vessels,SKS and SSS have similar long-term outcomes.The SKS group has a higher success rate of PCI and shorter operation duration.

Objective To investigate the dose-effect relationship of mRNA level of sensitive mitochondrial genes in human lymphoblastoid cells induced by ionizing radiation.Methods Seven human sensitive genes,including ND3,Cyt b,COX Ⅰ,COX Ⅱ,COX Ⅲ,ATPase6 and ATPase8 were chosen.Changes of mRNA level of these genes were detected by RT-PCR and Real-Time PCR at 24 h after irradiation in human lymphoblastoid cells,which were exposed to 0 - 15 Gy of 60 Co γ-rays.Results The expression of these 7 genes at mRNA level was up-regulated 24 h after irradiation in human lymphoblastoid cells.The level of gene expression of COX Ⅰ,which belongs to complex Ⅳ of mitochondrial respiratory chain,was most obvious,and the peak occurred after irradiation of 8 Gy,which was 13 times of the control group.A good dose-effect relationship was showed for COX Ⅲ gene expression at dose range of 3 -10 Gy as well as 3 - 15 Gy for other 3 genes including ND3,ATPase6 and ATPase8.Conclusions Gene expression levels of COX Ⅲ,ND3,ATPase6 and ATPase8 24h post-irradiation at certain irradiation dose range could be used for radiation damage biomarkers.

OBJECTIVETo investigate the human mitochondrial DNA (mtDNA) variations associated with longevity in Bama elderly population from Guangxi.

METHODSMitochondrial genome of 20 individuals over 96 years of age was sequenced, and seven target single nucleotide polymorphism (SNPs) were observed by comparing with the standard rCRS sequence, and two were tested by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in a larger population including 208 individuals of 90-113 years old, and 586 unrelated control individuals from Guangxi.

RESULTSThe 4824G frequency of the mtDNA4824A/G locus increased with age both in the long-lived elderly and in controls. And it was significantly higher in controls than that in long-lived population (P<0.05).

CONCLUSIONThe mtDNA4824 A/G is not only an age-related locus, its mutation is also negatively correlated with longevity.

Aged ; China ; ethnology ; DNA, Mitochondrial ; analysis ; genetics ; Genome, Mitochondrial ; genetics ; Haplotypes ; Humans ; Longevity ; genetics ; Mutation ; Myanmar ; ethnology ; Polymorphism, Genetic ; Polymorphism, Restriction Fragment Length ; Polymorphism, Single Nucleotide ; genetics ; Population Groups