[目的]针对2011年3月11日日本福岛核事故,于2011—2013年采取相应的技术措施监测北京地区河、湖水与饮用水放射性污染水平,即该两类水中总α、总β放射性水平,确保饮用水的放射性污染水平不超过国家相关标准限值要求,为将来河、湖水的放射性水平可能发生的变化提供基础数据。[方法]制定采集计划,每年分别在枯水期和丰水期采集河、湖水和饮用水,样品的采集覆盖北京市16个区（县）,依据GB/T 5750.13—2006《生活饮用水标准检验方法》和GB 5749—2006《生活饮用水卫生标准》进行采集,采用相对比较测量法对水样总α、总β放射性进行测量分析。[结果]河、湖水样品中,总α放射性水平算术平均值范围为0.06~0.15 Bq/L,总β放射性水平平均值范围为0.20~0.25 Bq/L;饮用水样品中,总α放射性水平算术平均值范围为0.09~0.11 Bq/L,总β放射性水平平均值范围为0.08~0.10 Bq/L。[结论]2011—2013年北京地区河、湖水及饮用水在枯水期和丰水期的放射性水平均未超过国家生活饮用水卫生标准指导值。

核或辐射紧急情况下,为避免不必要的辐射照射风险和有效支持现场减灾活动,应急工作人员的防护与安全是必须考虑的一个关键问题[1].政府必须制定关于管理、控制和记录应急工作人员在紧急情况下所受剂量的计划,该计划必须由响应组织和雇主实施[2]. 文献[3]介绍了日本东京电力公司(TEPCO)福岛第一核电站特大事故(以下或简称福岛事故)期间放射工作人员的受照情况和剂量管理措施,对改善应急照射剂量管理应关注的问题也进行了有益的探讨.现对其所涉问题进一步补充说明如下.

Objective To investigate the dose-,time-effect of STAT3 activation induced by radiation and explore the underlying signal pathway.Methods Pulmonary adenocarcinoma cells (H322) with mutated p53 gene were irradiated with 0-10 Gy of γ-rays.After radiation,the expression and transcriptional activity of STAT3 and the levels of its upstream molecules,including p-EGFR,were detected by Western blot.The nucleus translocation of p-STAT3 was examined by immunofluorescence staining assay.Results The protein expression and transcriptional activation of p-STAT3 in H322 cells were increased by 1.9-6.6 fold after 2-10 Gy radiation and increased by 1.2-9.5 fold after 0-24 h of irradiation.In addition,the expression of p-EGFR was also increased by 4.3-19.2 fold after irradiation.Conclusions After radiation,the expression of p-STAT3 in the pulmonary adenocarcinoma H322 cell can be increased probably through EGFR/STAT3 signal pathway.

Objective To investigate the effect of ionizing radiation on the expression of transcription factor STAT3 target genes in the pulmonary adenocarcinoma cell line A549.Methods The expressions of VEGF,Bcl-2 and Survivin in A549 cells with or without STAT3 inhibition were detected by RT-PCR and/or Western blot 24 h after 2 or 4 Gy of γ-ray irradiation.Results After γ-ray irradiation with 2 or 4 Gy,the expression of VEGF and Survivin increased significantly.However,the expression of Bcl-2 was not affected by γ-ray irradiation.Furthermore,the increased expression of VEGF and Survivin induced by radiation was found to be inhibited after radiation-induced activation of STAT3 was blocked by AG490 inhibiter.Conclusions γ-ray irradiation could up-regulate the expression of Survivin and VEGF via activating STAT3.The increase of Survivin might partly inhibit the radiation-induced apoptosis of A549 cells,and the up-regulation of VEGF might contribute to the tumor angiogenesis.

超大城市是指市区非农业人口超过200万人的特大城市，如上海、北京等。

重大活动是指具有特定规模的政治、经济、文化、体育及其他重大社会活动。核与辐射突发事件是指突然发生的，由放射性物质或其他放射源造成或可能造成严重影响公众健康的紧急事件。核与辐射突发事件主要包括：核与辐射事故和核与辐射恐怖袭击两大类型。重大活动中的核与辐射突发事件以核恐怖袭击为主。

Objective To investigate the effect of whole-body irradiation with low-dose γ-rays on the central nervous system of mice.Methods Fifty C57 mice were randomly divided into 3 groups and treated with 0,0.5,1 Gy whole-body irradiation,respectively.24 or 48 h after irradiation,brain tissue of mice was resected and homogenated.The levels of amino acid neurotransmitter,including Glu,Asp,GABA and Gly in brain homogenate were measured by high performance liquid chromatography (HPLC).Results Compared to the brain tissue of untreated mice,the contents of Glu and Asp at 0.5 and 1 Gy (t=-4.080,-3.935,-4.416,-3.630,-4.831, - 4.656,P ＜0.05) in mice brain tissue significantly increased at 24 h at 1 Gy and 48 h.However,the contents of Glu and Asp had no obvious changes in mice brain tissue 24 h after 1 Gy of irradiation. The contents of GABA and Gly had no difference between irradiated groups and untreated control group. Conclusions Short-term whole-body irradiation with low-dose γ-rays induces slight stimulation effect on the central nervous system of mice.

上海世博会三防医学应急救援保障中，由3个单位抽组人员组成三防医学救援队，分别为三防主力队，专家组，医疗救治组。由于人员数量偏少，核化救援分队的各组人员共用。辐射侦检组由1名辐射专业人员和1名防化专业人员组成。当执行辐射应急时，主要由辐射专业人员主持侦检工作，另1名成员作风速、风向测量及记录数据等配合工作。

在事故区上风向、距离事故区（污染控制区）50～100 m位置建立临时医疗站，见图1。其中：洗消区靠近装备洗消站，包括伤员洗消通道和非伤员洗消通道，细分为伤员接收区（放射性物质收集和污染检查）、洗消区（划分全身淋浴、担架伤员洗消、眼睛洗消、头部洗消等功能区）和洗消后处理区（污染控制检查和更衣）；放射性检验评价区包括外照射剂量评估及放射病分类诊断和内污染检查与评估；污染伤员急救区主要负责危重伤员的生命抢救；后送区包括污染伤员后送和去污染伤员后送。此外，在整个现场处置期间密切监测风向，当风向发生改变时，应及时调整医疗站位置。

Objective To investigate the effect of ionizing radiation on the invasion of the pulmonary adenocarcinoma cell line A549.Methods The invasiveness of A549 cells irradiated with 2 and 4 Gy doses of γ-rays was detected by using transwell invasion assay.The expression levels of matrix metalloproteinase (MMP)-2 mRNA and protein and phosphorylated signal transducers and activators of transcription 3 ( STAT3 ) protein were detected by reverse transcription PCR and Western blot.Results After irradiation with 2 or 4 Gy, the invasiveness of A549 cells increased by 200.0% ( F = 111.7, P ＜ 0.01 ) and 390.9% ( F = 593.7, P ＜ 0.01 ), respectively, compared with that in untreated A549 cells.Furthermore, the transcription and protein expression of MMP-2 24 h after irradiation and the phosphorylation of STAT3 12 h after irradiation were promoted.The irradiation-induced elevation of MMP-2 protein expression was suppressed using STAT3 phosphorylation specific inhibitor (AG490).Moreover,compared with 4 Gy of irradiation alone, treatment with 4 Gy of irradiation plus AG490 decreased the number of invasive cells by 76.1% ( F = 555.9, P ＜ 0.01 ), and the number of invasive cells in 4 Gy of irradiation plus AG490 group made up only 117.8% of that in untreated group ( F = 3.6, P ＞ 0.05 ).Conclusions Ionizing radiation could activate STAT3, which triggers the transcription of MMP-2, and then promote the invasiveness of A549 cells.

Objective To investigate the effects of signal transducer and activator of transcription 3 (STAT3) RNAi on the content of reactive oxygen species (ROS) and the DNA damage in glioma cells.Methods Glioma cells of the line U251 cells were cultured and transfected with STAT3 RNAi plasmid (pSilencer2.1-STAT3,STAT3 group) and pSilencer2.1-GFP (GFP control group) respectively.Part of the U251 cells were irradiated with γ-rays of 60Co as positive control group of smear phenomenon.The levels of ROS and malondialdehyde (MDA) in the cells were detected 24,48,and 72 h later by flow cytometry and fluorescence chamoluminescence analyzer,respectively.The DNA damage in the transfected U251 cells was examined by using single cell gel electrophoresis assay,and the cell cycle distribution was examined using FACS PI staining 12,24,and 36 h later.Results At 24 h after the transfection,the ROS level of the siSTAT3-transfected ceils was 8.91 times that of the control group (F = 89.296,P < 0.05),and returned to the normal level 48 h later.There were not significant differences in the MDA level of the cells 24,48,and 72 h later between the siSTAT3 group and siGFP group.Compared with the 8 Gy irradiation positive group with obvious smear phenomenon,smear phenomenon was shown in part of the ceils in the siSTAT3 group 6 h later,became less 12 h later,and disappeared completely 24 h later.Compared with the control group,lag of S stage rate was 17.22% and the lag of G2/M stage rate was 6.4% 12 h later in the siSTAT-transfected group,and the G0/G1 stage lag rate was 18.44% 24 h later,and the lag of S stage rate was 17.99% 36 h later.Conclusions Inhibition of STAT3 results in the change of oxidoreduction status in glioma cells,as well as damage and reparation of DNA.

OBJECTIVE:To study the effects of ionizing radiation on the proliferation,apoptosis and cell cycle of gastric adenocarcinoma cells in vitro.METHODS:After gastric adenocarcinoma BGC-823 cells were irradiated by ~(60)Coγ-rays with a single dose of 0,2 or 4 Gy,the proliferation ability of BGC-823 cells in every dose group was evaluated by MTT and cloning efficiency assay.Apoptosis and cell cycle were further investigated by flow cytometry with Annexin-V/PI double staining and PI staining,respectively.RESULTS:Compared with the 0 Gy group,proliferation of gastric adenocarcinoma cells was inhibited significantly after doses of 2 and 4 Gyγ-rays irradiation(P0.05). Furthermore,the cells were arrested in S then G_2/M phases afterγ-rays irradiation of 2 and 4 Gy.Finally,compared with 0 Gy group,the percentage of apoptotic cells in 4 Gy dose group increased significantly 48 h after irradiation(P0.05). CONCLUSION:Radiation treatment of gastric adenocarcinoma BGC-823 cells with ~(60)Coγ-rays could inhibit cell proliferation,induce cell cycle arrest and promote apoptosis.

Objective To observe the mRNA and protein expressions of S100A4 and MMP -2,to detect the changes of migrative and invasive abilities of human pancreatic cancer Bxpc-3 cells when S100A4 gene was silenced, and to discuss the role of S100A4 gene on metastasis of pancreatic cancer. Methods Human pancreatic cancer Bxpc-3 cells were transfected in vitro with sequence -specific siRNA targeting S100A4 gene using RNA interference technique. The mRNA and protein expression of S100A4 and MMP-2 before and after transfection were detected by real-time PCR and western- blot respectively. The changes of migrative and invasive abilities were detected by Transwell chamber model. Results The expressions of S100A4 and MMP-2 were both decreased. The migrative and invasive abilities were reduced obviously (P 0.05). Conclusions S100A4 gene upregulating the expression of MMP -2 is one of the roles of high invasion of tumor cells. S100A4 gene can be considered as one of the target for gene therapy of human pancreatic cancer.

Background The Beijing genotype of M. tuberculosis is a virulent strain that is disseminating worldwide and has a strong association with drug resistance. In the Western Cape of South Africa, epidemiological studies have identified the R220 cluster of the Beijing genotype as a major contributor to a recent outbreak of drug-resistant tuberculosis. Although the outbreak is considered to be due to clonal transmission, the relationship among drug resistant isolates has not yet been established. Results To better understand the evolution of drug resistance among these strains, 14 drug-resistant clinical isolates of the Beijing genotype were sequenced by whole-genome sequencing, including eight from R220 and six from a more ancestral Beijing cluster, R86, for comparison. While each cluster shares a distinct resistance mutation for isoniazid, mapping of other drug-resistance mutations onto a phylogenetic tree constructed from single nucleotide polymorphisms shows that resistance mutations to many drugs have arisen multiple times independently within each cluster of isolates. Thus, drug resistance among these isolates appears to be acquired, not clonally derived. This observation suggests that, although the Beijing genotype as a whole might have selective advantages enabling its rapid dissemination, the XDR isolates are relatively less fit and do not propagate well. Although it has been hypothesized that the increased frequency of drug resistance in some Beijing lineages might be caused by a mutator phenotype, no significant shift in synonymous substitution patterns is observed in the genomes. Conclusion While MDR-TB is spreading by transmission in the Western Cape, our data suggests that further drug resistance (i.e. XDR-TB) at this stage is acquired.

The publication of the complete genome sequence for Mycobacterium tuberculosis H37Rv in 1998 has had a great impact on the research community. Nonetheless, it is suspected that genetic differences have arisen in stocks of H37Rv that are maintained in different laboratories. In order to assess the consistency of the genome sequences among H37Rv strains in use and the extent to which they have diverged from the original strain sequenced, we carried out whole-genome sequencing on six strains of H37Rv from different laboratories. Polymorphisms at 73 sites were observed, which were shared among the lab strains, though 72 of these were also shared with H37Ra and are likely to be due to sequencing errors in the original H37Rv reference sequence. An updated H37Rv genome sequence should be valuable to the tuberculosis research community as well as the broader microbial research community. In addition, several polymorphisms unique to individual strains and several shared polymorphisms were identified and shown to be consistent with the known provenance of these strains. Aside from nucleotide substitutions and insertion/deletions, multiple IS6110 transposition events were observed, supporting the theory that they play a significant role in plasticity of the M. tuberculosis genome. This genome-wide catalog of genetic differences can help explain any phenotypic differences that might be found, including a frameshift mutation in the mycocerosic acid synthase gene which causes two of the strains to be deficient in biosynthesis of the surface glycolipid phthiocerol dimycocerosate (PDIM). The resequencing of these six lab strains represents a fortuitous "in vitro evolution" experiment that demonstrates how the M. tuberculosis genome continues to evolve even in a controlled environment.

Objective To study the expression and regulation of S100A8,a calcium-binding protein,in mouse macrophage cell line RAW264.7,which was used as cellular model of radiation injury.Methods RAW264.7 cells were exposed to γ-ray irradiation and/or lipopolysaccharide(LPS),then the mRNA level of S100A8 was detected by RT-PCR and real-time quantitative PCR methods.Real-time quantitative PCR was used to investigate the mRNA level of S100A8 in H2O2 or camptothecin treated cells.The second messenger in signal-transduction pathway was explored.To find γ-ray irradiation response element in the region 5' to the transcription start site,a series of 5' deletion fragments of this sequence linking luciferase reporter gene were constructed,and relative luciferase activity was measured after transfection and irradiation.Results The expression level of S100A8 mRNA was increased by irradiation.The expression of S100A8 in H2O2 treated cells was increased.However,no change was found in the expression of camptothecin treated cells.The expression level of luciferase reporter gene didn't change either after irradiation.Conclusions It has been revealed in present study that γ-ray irradiation or LPS challenge can induce the mRNA expression of S100A8,and that the cooperative effect between γ-rays and LPS can further increase the mRNA expression of S100A8 in RAW264.7.The second messenger of γ-ray induced S100A8 expression appears to be ROS rather than DNA damage.The responsive element to γ-ray radiation was not at position-877 to 0.It is likely that γ-ray radiation may regulate the expression of S100A8 by increasing its mRNA stability rather than influencing transcription frequency.

AIM:To explore the effect of activating the murine macrophage cell line RAW264.7 by both gamma-rays and lipopolysaccharide (LPS) and to study the expression of calcium-binding protein S100A8 induced by gamma-rays and LPS.METHODS:The RAW264.7 cells were observed by phase contrast microscope. The cell cycle and the level of reactive oxygen intermediates (ROIs) were detected by flow cytometry (FCM). The production of NO was measured by colorimetric Griess reaction. The mRNA expression of S100A8 was recorded by real-time quantitative RT-PCR method.RESULTS:The exposure of RAW264.7 cells to gamma-rays and LPS resulted in the morphological change of cells, the rise of cells number of aneuploid and apoptosis, and the rise of the level of ROI, NO and S100A8 mRNA. The effect of using both gamma-rays and LPS was stronger than that of single gamma-rays or LPS treatment.CONCLUSION:The mechanism of using both gamma-rays and LPS for activating macrophages is owing to the various biological effects including the change of cell cycle, the change of the level of messenger molecules and the expression of inflammation factor such as S100A8. The expression of S100A8 gene is closely correlated with the function and state of macrophages.