首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 234 毫秒
1.
目的 探讨基因组合表达模型作为辐射生物剂量计的可行性。方法 0~8 Gy 60Co γ射线照射正常人外周血,利用实时荧光定量PCR检测10个辐射敏感基因表达变化,应用逐步回归方法建立基因组合表达模型;双盲法验证模型估算剂量的准确性。结果 照后6和12 h,10个辐射敏感基因的表达水平随受照剂量的增加而增加,均呈现良好的剂量-效应关系(R2=0.61~0.97,P< 0.05);TNFSF4、PHPT1和FDXR基因相对表达量存在较大的个体间差异;照后6 h,PCNA、CCNG1、TNFSF4、PHPT1、GADD45A和FDXR建立的基因组合表达模型R2为0.88(F=54.8,P<0.001);照后12 h,PCNA、CCNG1、TNFSF4、MDM2、GDF15和TNFRSF10B建立的基因组合表达模型R2为0.82(F=42.767,P<0.001);各时间点基因组合表达模型估算的受照剂量均接近于真实照射剂量。结论 基因组合表达模型具备作为辐射生物剂量计的基本条件。  相似文献   

2.
目的 以核质桥(NPB)为主要指标,探索低剂量60Co γ射线是否能诱导人外周血淋巴细胞的适应性反应及诱导剂量范围。方法60Co γ射线照射健康成年男子离体外周血,照射剂量分别为0、20、50、75、100、150和200 mGy(吸收剂量率为25 mGy/min),照射后间隔6 h后再给予2 Gy照射(吸收剂量率为1 Gy/min)。采用胞质分裂阻滞法(CBMN)进行细胞培养,观察NPB及微核(MN)的发生情况。结果 0~200 mGy剂量范围内,NPB和MN数目随吸收剂量的增加而增多,并拟合出NPB的线性平方模型y=(1.5×10-4)x2-(5.67×10-3)x+0.598 (R2=0.893 8)。提前给予75~100 mGy照射比直接受到2 Gy照射产生的NPB及MN数目均有所减少(U=2.66、2.97、3.96、5.89,P<0.05),在100 mGy照射后NPB减少最多(43.2%)。结论 低剂量60Co γ射线可以诱导人外周血淋巴细胞的适应性反应,诱导剂量范围为75~100 mGy。  相似文献   

3.
目的 探讨125I粒子和60Co γ射线对非小细胞肺癌(NSCLC)A549细胞和正常支气管上皮BEAS-2B细胞生物学效应的影响。方法 A549、BEAS-2B细胞均行125I粒子和60Co γ射线不同剂量照射;集落形成实验检测细胞存活分数;流式细胞术检测细胞周期和细胞凋亡率;Western blot检测凋亡相关蛋白的表达水平。结果 A549细胞在4、6、8 Gy照射时,125I粒子组细胞克隆存活分数较60Co组降低更明显(t=6.06、9.42、4.90,P<0.05)。A549细胞在4 Gy时,G1期细胞比例125I粒子组为70.67%±1.49%,60Co组为59.59%±0.71%(t=10.77,P<0.05);细胞凋亡率125I粒子组为18.09%±0.73%,60Co组为9.81%±0.16%(t=19.40,P<0.05)。125I粒子照射明显上调Bax、cleaved Caspase-3蛋白的表达,同时下调Bcl-2蛋白的表达。但不同射线同一剂量或相同射线不同剂量下,BEAS-2B细胞的凋亡率及凋亡相关蛋白的表达无明显变化。结论 125I粒子持续低剂量率照射较60Co γ射线高剂量率照射抑制A549细胞增殖的效应更明显。Bcl-2/Bax蛋白比失衡,最终致Caspase-3蛋白的活化在125I粒子持续低剂量率照射抑制肿瘤细胞增殖的效应中可能发挥重要的作用。  相似文献   

4.
目的 根据扫描显微镜搭配玻片扫描软件(Metafer 4),在松弛素B(CB)阻断微核法试验中识别和鉴定微核,建立60Co γ射线照射剂量与人外周血淋巴细胞微核率的剂量-效应曲线。方法 采集4名健康人(2男2女)肘静脉血样品,用0、0.25、0.5、1、2、3、4和5 Gy 60Co γ射线(剂量率0.74 Gy/min)离体照射,胞质分裂阻断微核法培养、收获和制备标本玻片,人工智能彩色识别分析系统分析并记录双核细胞和微核数。应用CABAS 软件拟合基于微核率的剂量-效应曲线。2份照射后的盲样进行生物剂量估算验证。结果 在0~5 Gy 剂量范围内,拟合的微核剂量-效应曲线符合二次多项式模型,回归方程为y=0.0321D2+0.0237D+0.0127(R2=0.998,D为剂量)。用拟合曲线对验证样本的剂量估算结果与实际照射剂量基本接近。结论 成功建立基于人工智能识别微核的剂量-效应曲线,为估算辐射生物剂量提供了可行方法。  相似文献   

5.
目的 探讨125I粒子持续性低剂量率照射下肿瘤细胞的凋亡和周期改变。方法 采用CL187人结肠癌细胞系体外培养,分为空白对照组、60Co单次高剂量率照射组、125I低剂量率照射组。单次高剂量率组以2 Gy/min给予细胞1、2、4、6、8和10 Gy的照射,低剂量率组以2.77cGy/h的初始剂量率给予相同剂量照射,照射后24 h根据肿瘤细胞死亡率和14 d克隆形成率评价不同照射方式对肿瘤细胞的杀伤效果。同时,用放射性125I粒子以2.77 cGy/h的剂量率,给予细胞2、5和10 Gy的照射,应用流式细胞术测量其凋亡和细胞周期的变化。结果 低剂量率组照射后细胞死亡率在1 Gy时低于60Co单次高剂量率组,随着剂量的上升,2 Gy后,超过单次高剂量率组,但整体上125I粒子照射后细胞死亡率高于60Co组(P=0.011)。125I持续性低剂量率照射组的克隆增殖率明显低于60Co单次高剂量率组(P=0.0021)。低剂量率照射下,2 Gy时仅能引起G2/M期阻滞和凋亡,5 Gy时达到峰值,10 Gy时细胞周期阻滞和凋亡的比率依然很高,但相对于5 Gy有所下降;同时G2/M期阻滞和凋亡变化呈现出相同的趋势。结论 在相同剂量条件下,125I粒子持续照射低剂量率照射比60Co单次高剂量照射对CL187肿瘤细胞具有更强的杀伤效应;G2/M期阻滞引起的凋亡是低剂量率照射杀伤肿瘤细胞的主要机制。  相似文献   

6.
目的 比较56Fe17+12C6+重离子束与60Co γ射线对人淋巴细胞染色体畸变、周期、凋亡的影响。方法 56Fe17+12C6+重离子束和60Co γ射线分别照射人淋巴细胞系Peng-EBV,吸收剂量均为0、0.5和2.0 Gy,56Fe17+重离子束剂量率为0.26~0.55 Gy/min,12C6+重离子束剂量率为0.30~0.50 Gy/min,γ射线照射剂量率为0.75 Gy/min。研究不同射线对染色体细胞畸变率、“双+环”畸变率的影响。利用流式细胞仪检测细胞周期和细胞凋亡。结果 12C6+56Fe17+重离子与60Co γ射线照射后细胞畸变率与0 Gy相比,差异有统计学意义(χ2=12.08~322.97,P<0.05)。“双+环”畸变率与0 Gy相比,差异有统计学意义(χ2=4.06~205.37,P<0.05)。其中,12C6+重离子束诱导的细胞畸变率和“双+环”畸变率最高,其次是56Fe17+重离子束,而且二者均高于60Co γ射线。56Fe17+12C6+离子束与60Co γ射线均能诱导人淋巴细胞发生明显的G2期阻滞,差异有统计学意义(t=-80.9~0.17,P<0.05),12C6+重离子、γ射线及56Fe17+重离子诱导的G2期阻滞程度依次降低。56Fe17+12C6+离子束与60Co γ射线均能促进细胞凋亡,差异有统计学意义(t=-22.65~0.87,P<0.05),12C6+重离子、γ射线及56Fe17+重离子诱导的早期凋亡率依次降低。结论 56Fe17+12C6+离子束与60Co γ射线均能诱导人淋巴细胞发生明显的染色体畸变、G2期阻滞及细胞凋亡。12C6+离子束诱导的染色体畸变、周期阻滞和凋亡程度最高。56Fe17+12C6+离子束与γ射线的生物学效应与LET相关。  相似文献   

7.
目的 应用实时荧光PCR技术检测不同剂量60Co γ射线照射后不同时间永生化淋巴细胞系AHH-1中S100A4基因的表达变化情况,探讨其基因表达变化的剂量和时间效应关系.方法 永生化淋巴细胞系AHH-1接受0、1、3、5、8、10、15、18 Gy 60Co γ射线照射后4、8、12、24、48和72 h,利用反转录聚合酶链反应(PCR)以及实时荧光PCR技术检测细胞S100A4基因表达水平,分析各时间点其基因的相对表达水平与不同照射剂量之间的关系.结果 照射后各时间点,一定剂量范围内,AHH-1中S100A4基因的表达水平上调,与照射剂量存在着一定的剂量-效应关系(R2=0.79~0.93,P<0.05);在一定时间范围内,AHH-1中S100A4基因表达水平的上调受照射后时间的影响(F=8.91,P<0.01).结论 在一定剂量范围内,辐射诱导的S100A4基因表达在转录水平的变化检测便捷,具有较好的剂量-效应关系,初步具备作为生物剂量计的基本条件.  相似文献   

8.
目的 建立检测γ射线照射剂量的新方法,探讨应用金纳米颗粒复合材料(ssDNA-AuNPs)比色检测γ射线照射剂量的可行性。方法 将寡核苷酸分子(ssDNA)修饰到金纳米颗粒(AuNPs)表面,制备出复合材料ssDNA-AuNPs。用60Co γ射线对其进行照射,剂量分别为0、5、10、20和30 Gy,而后观察溶液颜色变化并测量紫外-可见吸收光谱,建立吸收光谱中625 nm处与521 nm处吸光度的比值(A625/A521)与照射剂量线性关系。结果 随着60Co γ射线照射剂量的不断增加,ssDNA-AuNPs溶液的颜色由酒红色逐渐变为蓝紫色。在0~30 Gy剂量范围内,吸收光谱中A625/A521的比值对其拟合线性方程为A625/A521=0.020 6+0.303 6ER2=0.991 5)。结论 本实验合成的ssDNA-AuNPs能够比色检测γ射线照射剂量,建立了一种比色检测γ射线照射剂量的新方法。  相似文献   

9.
目的 确定核质桥判定标准,建立 60Co γ 射线诱导正常人外周血淋巴细胞中核质桥(NPB)的剂量-效应曲线。 方法 60Co γ 射线照射3名健康男性离体外周血,照射剂量分别为0、1、2、3、4、5和6 Gy,剂量率为1 Gy/min,采用胞质分裂阻滞微核(CBMN)法进行细胞培养、收获、制片、染色。在光学显微镜下分析双核细胞中NPB及微核(MN)。 结果 在0~6 Gy 60Co γ 射线照射后,人外周血双核淋巴细胞中的NPB符合泊松分布,且NPB频率随吸收剂量增加而增加(H=19.51,P<0.01),拟合回归方程为线性平方模式y=(1.39×10-3x2 + (4.94×10-3xR2=0.981,P < 0.01)。 结论 成功建立 0~6 Gy 60Co γ 射线诱导正常人外周血淋巴细胞中NPB的剂量-效应曲线。  相似文献   

10.
目的 比较60Co γ射线照射及环磷酰胺对小鼠造血和免疫功能损伤的规律,为急性放射综合征(ARS)患者临床救治提供实验依据.方法 48只雌性BABL/c小鼠随机数字表法分为照射组、化疗组,每个剂量组6只.照射组接受60Co γ射线照射,吸收剂量为2、4、6和8 Gy;化疗组注射环磷酰胺,剂量为100、150、200和250 mg/kg.处理后采尾静脉血,进行血常规检测.选择白细胞(WBC)差异无统计学意义的2 Gy和200 mg/kg组,处理后流式细胞术检测T、B、NK及调节T细胞.结果 各组外周血WBC计数均先下降,4 d后降至最低值.化疗组和2 Gy照射组WBC迅速回升,10~12 d基本恢复;而4 Gy照射组恢复较慢,6和8 Gy组不能自行恢复.2 Gy照射组与200 mg/kg化疗组差异无统计学意义,其余照射组与200 mg/kg化疗组的差异有统计学意义(t=2.531, 2.343, 2.074, P<0.05).2 Gy照射组CD8+T细胞数较200 mg/kg化疗组明显下降(F=5.026,P<0.05),2 Gy照射组调节T细胞在照射后升高,与200 mg/kg化疗组比较差异有统计学意义(F=4.848,P<0.05),但CD4+T、B和NK细胞数两组之间差异无统计学意义.结论 电离辐射较化疗对造血、免疫功能的损伤较大,恢复较慢.因此,在ARS患者中可针对性延长造血刺激因子和集落刺激因子的使用,以起到预防感染、出血及败血症、帮助造血及免疫系统重建的作用.  相似文献   

11.
Acute limping may be the result of multiple pathologies in children. The differential diagnosis varies based on the age of the child. Irrespective of age, the initial imaging work-up includes AP and frog leg radiographs of the pelvis and ultrasound; MRI may sometimes be helpful. In children less than 3 years, infections and trauma are most frequent. MRI is the imaging modality of choice when osteomyelitis is clinically suspected. Between the ages of 3 and 10 years, transient synovitis of the hip and Legg-Calvé-Perthes disease are main considerations but infection, inflammation and focal bony lesions are also considered. In children over 10 years, slipped capital femoral epiphysis also is considered.  相似文献   

12.
KEY POINTS ·High-intensity interval training(HIT)is characterized by repeated sessions of relatively brief,intermittent exercise.often performed with an“a11 out”effort or at an intensity close to that which elicits peak oxygen uptake(i.e.,≥90%of VO2 peak).  相似文献   

13.
In response to the ENFSI and EDNAP groups’ call for new STR multiplexes for Europe, Promega® developed a suite of four new DNA profiling kits. This paper describes the developmental validation study performed on the PowerPlex® ESI 16 (European Standard Investigator 16) and the PowerPlex® ESI 17 Systems. The PowerPlex® ESI 16 System combines the 11 loci compatible with the UK National DNA Database®, contained within the AmpFlSTR® SGM Plus® PCR Amplification Kit, with five additional loci: D2S441, D10S1248, D22S1045, D1S1656 and D12S391. The multiplex was designed to reduce the amplicon size of the loci found in the AmpFlSTR® SGM Plus® kit. This design facilitates increased robustness and amplification success for the loci used in the national DNA databases created in many countries, when analyzing degraded DNA samples. The PowerPlex® ESI 17 System amplifies the same loci as the PowerPlex® ESI 16 System, but with the addition of a primer pair for the SE33 locus. Tests were designed to address the developmental validation guidelines issued by the Scientific Working Group on DNA Analysis Methods (SWGDAM), and those of the DNA Advisory Board (DAB). Samples processed include DNA mixtures, PCR reactions spiked with inhibitors, a sensitivity series, and 306 United Kingdom donor samples to determine concordance with data generated with the AmpFlSTR® SGM Plus® kit. Allele frequencies from 242 white Caucasian samples collected in the United Kingdom are also presented. The PowerPlex® ESI 16 and ESI 17 Systems are robust and sensitive tools, suitable for the analysis of forensic DNA samples. Full profiles were routinely observed with 62.5 pg of a fully heterozygous single source DNA template. This high level of sensitivity was found to impact on mixture analyses, where 54–86% of unique minor contributor alleles were routinely observed in a 1:19 mixture ratio. Improved sensitivity combined with the robustness afforded by smaller amplicons has substantially improved the quantity of data obtained from degraded samples, and the improved chemistry confers exceptional tolerance to high levels of laboratory prepared inhibitors.  相似文献   

14.
The Knee injury and Osteoarthritis Outcome Score (KOOS) is a self-administered instrument measuring outcome after knee injury at impairment, disability, and handicap level in five subscales. Reliability, validity, and responsiveness of a Swedish version was assessed in 142 patients who underwent arthroscopy because of injury to the menisci, anterior cruciate ligament, or cartilage of the knee. The clinimetric properties were found to be good and comparable to the American version of the KOOS. Comparison to the Short Form-36 and the Lysholm knee scoring scale revealed expected correlations and construct validity. Item by item, symptoms and functional limitations were compared between diagnostic groups. High responsiveness was found three months after arthroscopic partial meniscectomy for all subscales but Activities of Daily Living.  相似文献   

15.
Objective To evaluate the preliminaily clinical efficacy and retrievability of a retrievable hinged covered metallic stent in the treatment of the bronchial stump fistula (BSF). Methods Between April 2003 and March 2005, 8 patients with bronchial stump fistula after pneumonectomy or lobectomy were treated with two types (A and B) of retrievable hinged covered metallic stents. Type A stent was placed in 6 patients and type B in 2 under fluoroscopic guidance. The stent was removed with a retrieval set when BSF was healed or complications occurred. Results Stent placement in the bronchial tree was technically successful in all patients, without procedure-related complications. Immediate closure of the BSF was achieved in all patients after the procedure. Stents were removed from all patients but one. Removal of the stents was difficult in two patients due to tissue hyperplasia. Patients were followed up for 6 - 21 months. Placement of the stents remained stable in all patients except one due to severe cough. Permanent closure of BSF was achieved in 7 (87.5%) of 8 patients. Conclusion Use of a retrievable hinged covered expandable metallic stent is a simple, safe, and effective procedure for closure of the BSF. Retrieval of the stent seems to be feasible. (J Intervent Radiol, 2007, 16: 253-257)  相似文献   

16.
17.
18.
19.
Zusammenfassung Bei der rechtsmedizinischen Identifizierung kann die Identität im strengen Sinn allenfalls bei lebenden Personen festgestellt werden; sonst läßt sich nur von Teilen auf das Ganze (vom Untersuchungsobjekt auf die Person) schließen, wobei die verschiedenen Merkmale des Untersuchungsobjektes entsprechend der Hdufigkeit ihres Vorkommens eine unterschiedliche Beweiskraft haben. Bei der Schädelidentifizierung mit Hilfe moderner photographischer oder elektronischer Superprojektionsverfahren ergeben sich unter Berücksichtigung der Weichteildicken so viele (fiktive) Vergleichspunkte, daß bei geeignetem Vergleichsmaterial (Photographien) Identität wegen der Vielzahl übereinstimmender Bezugspunkte in den meisten Fällen evident ist.  相似文献   

20.
This is a review of the role of imaging procedures for the assessment of abdominal and pelvic lymph nodes. The diagnosis of malignant lymphatic spread is rarely the sole purpose of imaging, because it is usually part of a general abdominal examination, most frequently with CT or US, or increasingly with MRI. These studies are often requested in order to obtain information about the situation to be encountered during surgery, or to alert the surgeon to irresectability or to unexpected metastases outside the initially planned area of exploration. In most surgically treated tumours the role of imaging for preoperative staging is limited, due either to its insufficient sensitivity or because the initial treatment is independent of the lymph node stage. Imaging is commonly used to verify treatment response to chemo- or radiotherapy and for follow-up.Correspondence to: S. Delorme  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号