靶向Slug基因诱导PUMA上调增强AsPC-1细胞对γ射线的敏感性研究

目的 探讨siRNA干扰Slug基因表达对胰腺癌AsPC-1细胞γ射线敏感性的影响。方法 以0、10、50、100感染复数(MOI)的rAAV-EGFP-Slug-siRNA(Slug-siRNA)转染AsPC-1细胞72 h,免疫组织化学法和Western blotting检测转染前后细胞内Slug和PUMA表达。采用4 Gy γ射线细胞进行照射,MTT比色法和Hoechst 33342和PI双染法检测对照组、转染组(MOI 50)、照射组、转染(MOI 50)+照射组细胞存活率和凋亡率,DNA琼脂糖凝胶电泳检测细胞凋亡,Giemsa 染色观察细胞形态。结果 细胞受到MOI为10、50、100作用72 h后,Slug 蛋白表达相对值分别为0.831±0.14、0.546±0.12和0.178±0.08,明显低于对照组1.17±0.152, 差异有统计学意义(F= 4.992,P<0.05);而细胞受到MOI为10、50、100作用72 h,PUMA 蛋白表达相对值分别为0.325±0.07、0.593±0.11和0.978±0.12,明显高于对照组0.143±0.04, 差异有统计学意义(F= 4.324,P<0.05);转染(MOI 50)+照射组细胞增殖抑制率为(78.76±9.36)%,明显高于转染组和单独射线照射组[(43.68±6.71)%和(19.25±3.72)%],差异有统计学意义(F=5.056,P<0.05)。另外,转染(MOI 50)+照射组细胞的凋亡现象较其他组更加明显。结论 siRNA干扰Slug基因表达能够解除Slug对PUMA的抑制,增强胰腺癌细胞对γ射线的敏感性。     

姜黄素提高人胰腺癌PANC-1细胞放射敏感性的机制研究

目的 观察姜黄素对人胰腺癌PANC-1细胞放射敏感性的影响。方法 γ射线照射人胰腺癌PANC-1细胞,同时联合应用姜黄素处理细胞,通过MTT法检测PANC-1细胞增殖活性的变化,利用流式细胞仪观察PANC-1细胞周期和凋亡率的变化,采用RT-PCR和Western blot分析PANC-1细胞中P21表达的变化。结果 与γ射线照射组比较,γ射线联合应用姜黄素可以显著降低PANC-1细胞的增殖活性(t=6.72, P<0.01),同时影响细胞周期的变化,显著增加S期细胞(t=4.78, P<0.05),PANC-1细胞凋亡明显提高(t=6.58,P<0.01),并伴有P21蛋白和mRNA表达的变化(t=5.72、5.63, P<0.01)。结论 姜黄素可以显著提高人胰腺癌PANC-1细胞的放疗敏感性,这一特性与P21的表达有关。     

干扰血管内皮生长因子表达联合γ射线对食管癌细胞移植瘤的影响

目的 研究反义cDNA干扰血管内皮生长因子(VEGF)表达联合γ射线对裸鼠移植瘤的影响,并观察各组裸鼠肿瘤病理组织学和细胞生物学特征的变化,为VEGF基因治疗联合放射治疗食管癌提供理论依据。方法 将32只Balb/c/nu裸鼠随机分为4组:对照组、单纯照射组、反义组和反义+照射组,使用已转染和未转染反义VEGFcDNA TE-1食管癌细胞株,分别建立裸鼠爪垫移植瘤模型, 瘤体直径0.8~1.0 cm,⁶⁰Co γ射线18 Gy单次照射单纯照射组与反义+照射组裸鼠移植瘤,对比观察各组移植瘤生长情况,检测移植瘤组织中VEGF mRNA和蛋白的表达,并分析肿瘤组织中细胞凋亡情况。结果 与未转染两组比较,转染两组瘤体生长速度慢,成瘤潜伏期延长(t=13.898, P<0.01)。反义组肿瘤体积为(1207.50±97.07)mm³,反义+照射组为(1057.5±91.50)mm³,两者差异无统计学意义(t=1.124,P>0.05),而此2组与对照组(5442.50±185.08)mm³ 和单纯照射组(2922.50±152.773)mm³ 体积间差异有统计学意义(t=9.475~21.238,P<0.01)。反义组与反义+照射组VEGF mRNA和蛋白表达较对照组和单纯照射组差异有统计学意义(F=387.394、13.519, P<0.01)。结论 抗VEGF治疗可有效地抑制裸鼠移植瘤的生长,但单纯抑制VEGF表达对增加裸鼠移植瘤放射治疗增敏效果有限,需进一步研究。     

EGFR抗体对持续低剂量率照射CL187细胞的放射增敏研究

目的 探讨表皮生长因子受体(EGFR)抗体对放射性¹²⁵I粒子持续低剂量率照射大肠癌细胞CL187的增敏作用。方法 采用CL187大肠癌细胞系体外培养,实验分空白对照组、单纯抗体组、单纯照射组、照射加不同浓度抗体组。用克隆形成方法评价不同处理方式对CL187细胞的杀伤效应。应用流式细胞仪检测细胞凋亡和周期的改变。结果 EGFR与射线联合作用细胞存活分数较单纯照射组明显下降(P<0.05)。EGFR抗体浓度2、5、10 nmol/L时增敏比分别为1.34、1.59、2.08。持续低剂量率照射4 Gy后,抗体联合照射组凋亡率(39.86%±4.38%)高于单纯抗体组(12.49%±1.59%)和单纯照射凋亡率之和(21.57%±2.97%),差异有统计学意义(P<0.05)。细胞周期检测显示表皮生长因子抗体联合照射主要引起细胞的G₁期阻滞(84.51%±3.42%),持续低剂量率照射主要引起G₂/M期阻滞(46.41%±4.48%),两者联合作用时,G₁期(59.31%±5.34%)和G₂/M期(38.10%±2.57%)细胞比率增加,S期(2.59%±1.19%)细胞比率明显减少(P<0.05)。结论 表皮生长因子抗体对持续低剂量率照射具有明显的放射增敏作用,其增敏机制主要来自细胞周期的重分布和细胞凋亡的增加。     

程序性死亡受体1抑制剂通过促进细胞 焦亡加重放射性心肌损伤的研究

目的 探讨程序性死亡受体1(PD-1)抑制剂通过细胞焦亡通路对放射性心肌损伤的影响。方法 20只C57BL/6雄性小鼠按随机数字表法分为4组:健康对照组;PD-1抑制剂组;单纯照射组(胸部单次照射20 Gy);照射联合PD-1抑制剂组,每组5只。超声心动测试评价受照后1个月小鼠左室射血分数(LVEF)、每搏输出量 (SV)、左室缩短率(FS);采用苏木精-伊红(HE)、Masson染色观察心肌组织病理学改变;蛋白免疫印迹、实时荧光定量反转录聚合酶链式反应(RT-qPCR)检测心肌组织焦亡关键因子半胱氨酸天冬氨酸蛋白水解酶1(Caspase-1)、消皮素D(GSDMD)、凋亡相关斑点样蛋白(ASC)表达水平;酶联免疫吸附实验(ELISA)检测白介素18(IL-18)、IL-1β表达;流式细胞术检测心肌淋巴细胞浸润情况。结果 照射后1个月,照射联合PD-1抑制剂组的LVEF、FS、SV较单纯照射组下降(t = 4.50、27.93、3.11,P <0.05); 照射联合PD-1抑制剂组小鼠心肌损伤及纤维化较单纯照射组更明显,心肌胶原容积分数较单纯照射组升高[(2.88±0.27)% vs. (3.81±0.57)%,t = 2.90,P<0.05];与单纯照射组比较,照射联合PD-1抑制剂组心肌Caspase-1、Caspase-1 p20、GSDMD、GSDMD-N、ASC蛋白表达量增高(t=3.14、3.22、8.83、20.29、2.79,P <0.05),Caspase-1、GSDMD、ASC的mRNA表达量也升高(t = 3.09、2.91、2.53,P <0.05);照射联合PD-1抑制剂组心肌及血清IL-18、IL-1β表达较单纯照射组均升高(t = 3.46、3.75、7.58、8.24,P <0.05),CD8+T淋巴细胞百分比高于单纯照射组[(38.33 ± 7.92)% vs. (54.70 ± 4.01)%,t = 3.29,P <0.05],而CD4+T淋巴细胞在各组间的差异无统计学意义(P >0.05)。结论 PD-1抑制剂可通过Caspase-1/GSDMD促进细胞焦亡,进而加重放射性心肌损伤。     

人类解旋酶样转录因子过表达促进辐射诱导的A549细胞凋亡

目的 探讨人类解旋酶样转录因子(HLTF)对辐射诱导细胞凋亡的影响及其机制。方法 将空质粒和带FLAG标签的HLTF表达质粒分别转染人肺癌细胞A549,⁶⁰Co γ射线照射观察细胞凋亡变化。用Western blot 检测HLTF在细胞核和胞质内水平的变化及线粒体细胞色素C的释放。结果 HLTF转染可促进γ射线诱导的细胞凋亡,凋亡率为(32.2±2.1)%,高于空载体转染组(11.4±2.3)%和Mock转染组(11.1±1.8)%(F=101.85,P<0.01)。辐射后HLTF在胞质内的表达水平显著提高。HLTF转染组胞质内细胞色素C的水平亦显著提高。结论 HLTF可促进辐射损伤诱导的细胞凋亡, 其部分机制可能是通过提高核质转位以及影响线粒体细胞色素C的释放来实现的。     

FAM83A对胰腺癌细胞PANC-1干细胞样表型和放射敏感性的影响

目的 探讨FAM83A对胰腺癌细胞PANC-1干细胞样表型和放射敏感性的影响,旨在为胰腺癌靶向治疗提供新思路。方法 慢病毒感染构建稳定沉默FAM83A的PANC-1细胞株,qPCR和Western blot进行验证;流式细胞仪检测干细胞标记物CD133阳性的细胞数;肿瘤细胞成球实验检测PANC-1细胞成球能力;MTT检测吉西他滨对PANC-1稳转株细胞活力的影响;平板克隆形成实验检测X射线照射对PANC-1稳转株细胞增殖的影响;流式细胞术检测吉西他滨和X射线照射对PANC-1稳转株细胞凋亡的影响;Western blot检测PANC-1稳转株细胞中Wnt/β-catenin信号通路表达变化。结果 沉默FAM83A后PANC-1细胞中FAM83A蛋白表达（0.83±0.08）和mRNA表达（0.29±0.03）较阴性对照组FAM83A蛋白表达（1.95±0.19）和mRNA表达（0.98±0.09）显著降低（t=9.410、12.600,P<0.05）;沉默FAM83A后CD133阳性PANC-1细胞率（8.97±0.62）%较阴性对照组（21.60±2.60）%显著降低（t=8.184,P<0.05）,且细胞成球数（8±1）较阴性对照组（25±3）亦显著降低（t=9.311,P<0.05）,PANC-1细胞干细胞样表型显著被抑制;沉默FAM83A联合50 μmol/L吉西他滨处理PANC-1细胞72 h后细胞活力（32.33±3.05）%较吉西他滨处理组（63.06±5.98）%显著降低,细胞凋亡率（76.52±8.34）%较吉西他滨处理组（40.88±4.91）%显著增加,差异有统计学意义（t=6.378、7.929,P<0.05）;沉默FAM83A联合X射线照射后,PANC-1细胞活力（43.25±4.21）%较X射线照射组（78.13±7.98）%明显降低,细胞凋亡率（44.56±5.32）%较X射线照射组（15.15±1.95）%明显增加,差异有统计学意义（t=6.694、8.990,P<0.05）;沉默FAM83A后细胞中Wnt/β-catenin信号通路蛋白Active-β-catenin表达降低,p-β-catenin表达增加,且细胞核中β-catenin表达也降低,差异有统计学意义（t=10.290、8.521、8.969,P<0.05）,而Total β-catenin无明显变化,细胞中Wnt/β-catenin信号通路活性明显被抑制。结论 沉默FAM83A可能通过Wnt/β-catenin信号抑制胰腺癌细胞干细胞样表型,增强细胞对化疗药物吉西他滨及放射敏感性,FAM83A将可为胰腺癌临床治疗提供新靶点。     

靶向Erk/Slug信号上调PUMA表达增强乳腺癌MDA-MB-231细胞对γ射线的敏感性

目的 研究Erk/Slug信号通路在乳腺癌细胞MDA-MB-231放射敏感性中的作用。方法 通过以NF-κB p65 siRNA、PUMA siRNA或Slug siRNA转染MDA-MB-231细胞,或以U0126处理该细胞之后,以4 Gy γ射线进行照射,在照射后的不同时间点检测细胞内Erk1/2、NF-κB p65、Slug和PUMA蛋白的表达,以MTT比色法检测细胞存活率,以TUNEL法检测细胞凋亡。 结果 与单纯照射组相比,NF-κB p65 siRNA/4 Gy 组,细胞PUMA表达明显下降;U0126/4 Gy组,细胞Erk1/2和Slug蛋白表达明显降低,PUMA表达明显升高;Slug siRNA/4 Gy组,Erk1/2蛋白表达无变化,但PUMA蛋白表达明显增加;同时,U0126/4 Gy组和Slug siRNA/4 Gy组,细胞照射48 h后存活率降至最低点,分别为19.78±2.71（F=11.39,P<0.05）和17.41±4.58（F=15.31,P<0.05）,细胞凋亡率升至最高点,分别为28.61±4.70（F=9.84,P<0.05）和 27.55±6.41（F=10.31,P<0.05）;NF-κBp65 siRNA/4 Gy组和PUMA siRNA/4 Gy组,细胞照射24h后存活率分别为85.65±9.60（F=12.31,P<0.05）和87.53±11.50（F=13.68,P<0.05）,细胞凋亡率明显下降,分别为3.28±0.78（F=10.83,P<0.05）和3.46±0.84（F=9.92,P<0.05）。结论 γ 射线照射后24 h内,MDA-MB-231细胞敏感性与依赖于NF-κB上调的PUMA表达有关;而照射24 h后,细胞的辐射抵抗性与依赖于Erk1/2上调的Slug表达有关,后者对PUMA表达有明显的抑制作用。     

miR-21反义寡核苷酸对SHG-44放射增敏作用的体外研究

目的 探讨抑制miR-21表达对SHG-44人脑胶质瘤细胞系放射敏感性的影响及其机制。方法 脂质体介导采用瞬间转染法转染反义miR-21寡核苷酸(AS-miR-21)及阴性对照寡核苷酸于胶质瘤SHG-44细胞中。设空白对照组、阴性对照转染组及AS-miR-21转染组,分别给予6 MeV X射线单次照射0、1、2、4、6和8 Gy,采用成克隆实验计算放射增敏比,并绘制细胞存活曲线。流式细胞仪检测上述3组及联合单次6 Gy照射后细胞凋亡率、细胞周期变化。结果 转染AS-miR-21组的D₀、D_q较空白对照组及阴性转染组降低,放射增敏比SER_D0、SER_Dq分别为1.32和2.10。细胞周期分析示,转染组较空白对照及阴性对照组的G₀/G₁期比例增高,S期比例降低(t =8.18、-4.52,P<0.05)。凋亡分析示,单纯照射组、AS-miR-21转染组及照射联合AS-miR-21转染组的早期凋亡率均高于对照组(t =20.14、11.11、50.07, P <0.05)。结论 AS-miR-21可增加胶质瘤SHG-44细胞系放射敏感性,其机制可能与促进细胞凋亡及周期再分布有关。     

脊柱适形调强放疗和普通放疗脊髓生物安全性的比较

目的 探讨脊柱适形调强放疗(IMRT)和普通放疗对犬脊髓的生物安全性。方法 选取纯种比格犬12只并随机分为2组,模拟犬胸9～10椎体肿瘤,以IMRT和普通放疗2种方式分别对2组比格犬胸9～10椎体给予50及70Gy剂量的放疗,于放疗3个月后活杀取材,取相同部位、相同位置的胸9～10节段脊髓行HE染色,电镜观察后,免疫组织化学法定量检测脊髓中Fas、HSP70蛋白的表达,TUNEL法定量检测脊髓中凋亡神经元。结果 照射3个月后可观察到脊髓的损伤,IMRT组脊髓神经元以可逆性损伤为主,而普通放疗组以凋亡为主。相同剂量的放疗,IMRT组细胞凋亡指数〔50Gy组为(1.2±0.7)%;70Gy组为(2.5±0.8)%〕均低于普通放疗〔50Gy组为(7.3±1.1)%,70Gy组为(11.3±1.4)%〕,两组比较差异有统计学意义(50Gy组t=0.022,P<0.05;70Gy组t=0.017,P<0.05);凋亡促进蛋白Fas表达量IMRT组(50Gy组为4.6±0.8;70Gy组为7.4±1.1)明显低于普通放疗组(50Gy组为15.1±6.4,70Gy组为19.3±7.6),两组比较差异有统计学意义(50Gy组t=0.231,P<0.05;70Gy组t=0.457,P<0.05);而凋亡抑制蛋白HSP70表达量IMRT组(50Gy组为9.1±0.8,70Gy组为7.3±1.4)明显高于普通放疗组(50Gy组为2.1±0.9,70Gy组为1.7±0.3),两组比较差异有统计学意义(50Gy组t=0.153,P<0.05;70Gy组t=0.223,P<0.05)。脊髓神经元凋亡指数与Fas/HSP70比值呈正相关(r=0.996,t=1.14,P<0.05)。结论 照射3个月后脊髓中存在着明显的放疗迟发反应。通过放疗后脊髓神经元形态学、神经元凋亡指数、凋亡相关蛋白表达等指标的测定结果提示脊柱IMRT的脊髓安全性远优于普通放疗。     

电磁脉冲造成神经细胞氧化损伤效应研究

电磁脉冲(EMP)作为一种非电离辐射,生物效应广泛,从自由基生物学角度研究其对神经细胞的辐射损伤效应具有一定的实际意义.方法采用自旋捕捉的方法检测自由基的变化,TBA法检测脂质过氧化产物丙二醛(MDA),DTNB法检测谷胱甘肽过氧化物酶(GSH-px)的活性,MTT法检测细胞存活率,流式细胞术检测细胞内Ca2+浓度.结果电磁脉冲作用大鼠大脑皮层细胞和海马细胞后,脂氧自由基水平升高.MDA水平升高,大脑皮层细胞对照组MDA水平为(6.18±0.29)nmol/mg,EMP作用组为(8.43±0.01)nmol/mg(P＜0.01);海马细胞对照组MDA水平为(4.38±0.15)nmol/mg,EMP作用组为(4.98±0.39)nmol/mg(P＜0.05).GSH-px活性降低,大脑皮层细胞对照组A值为0.026±0.001,EMP作用组为0.022±0.002(P＜0.05),海马细胞对照组A值为0.021±0.002,EMP作用组为0.018±0.001(P＜0.05).电磁脉冲不能直接杀死细胞,其存活率约为95%,当脉冲数达到10次时,细胞内Ca2+浓度开始升高.结论电磁脉冲提高了神经细胞脂氧自由基水平,脂质过氧化产物MDA水平升高,GSH-px活性降低,预示氧化损伤效应的发生.另外,电磁脉冲不能直接杀死细胞,但可导致细胞内Ca2+浓度升高,增多的Ca2+可能成为诱发细胞凋亡的重要因素之一.     

PKM2基因沉默对人肺癌A549细胞放射敏感性的影响

目的 探讨通过siRNA干扰技术沉默丙酮酸激酶同工酶M2(pyruvate kinase M2,PKM2)基因表达对人肺癌A549细胞放射敏感性的影响。方法 以人肺癌A549细胞为研究对象,根据PKM2 mRNA编码序列设计并合成干扰siRNA序列,瞬时转染A549细胞。用RT-PCR和Western blot法分别从mRNA水平和蛋白水平检测PKM2基因的表达。设PKM2 siRNA干扰组,阴性对照组、空白对照组。各组细胞分别接受不同剂量6 MV X射线照射,通过集落形成实验检测细胞放射敏感性,流式细胞仪检测各组细胞周期及凋亡率。每组实验重复3次。结果 RT-PCR和Western blot显示,PKM2 siRNA干扰组较空白对照组的PKM2 mRNA和蛋白表达都明显下降(t=20.91、47.00,P<0.01),抑制率分别为(70.27±1.38)%和(70.42±1.18)%;集落形成实验显示,PKM2 siRNA干扰+IR组A549细胞 D₀、D_q、N和SF₂值均低于空白对照+IR组(t=43.82、28.44、15.60、29.63,P<0.01),放射增敏比(SER)为1.27。流式细胞仪分析显示,PKM2 siRNA干扰组G₂/M期细胞的百分率明显高于空白对照组(t=8.35,P<0.01),经10 Gy X射线照射,G₂/M期细胞比例也明显升高(t=27.87,P<0.01)。两者联合使用后G₂/M期阻滞更加明显。siRNA干扰组细胞凋亡率较空白对照组无显著升高,空白对照+IR组较空白对照组凋亡率明显升高(t=23.99,P<0.01);PKM2 SiRNA干扰+IR组较空白对照+IR组和PKM2 siRNA干扰组差异均有统计学意义(t=9.42、65.21,P<0.01)。结论 特异性沉默PKM2基因表达能够增加A549细胞的放射敏感性,推测其机制可能与改变细胞周期分布及使射线诱导细胞凋亡的作用增强有关。     

Pancreatic diffusion‐weighted imaging (DWI): Comparison between mass‐forming focal pancreatitis (FP), pancreatic cancer (PC), and normal pancreas

Purpose

To compare diffusion‐weighted imaging (DWI) findings and the apparent diffusion coefficient (ADC) values of pancreatic cancer (PC), mass‐forming focal pancreatitis (FP), and the normal pancreas.

Materials and Methods

DWI (b = 0 and 600 seconds/mm²) findings of 14 patients with mass‐forming FP proven by histopathology and or clinical follow‐up, 10 patients with histopathologically‐proven PC, and 14 subjects with normal pancreatic exocrine function and normal imaging findings were retrospectively evaluated. ADC values of the masses, the remaining pancreas, and the normal pancreas were measured.

Results

On b = 600 seconds/mm² DWI, mass‐forming FP was visually indistinguishable from the remaining pancreas whereas PC was hyperintense relative to the remaining pancreas. The mean ADC value of PC (1.46 ± 0.18 mm²/second) was significantly lower than the remaining pancreas (2.11 ± 0.32 × 10^–3 mm²/second; P < 0.0001), mass‐forming FP (2.09 ± 0.18 × 10^–3 mm²/second; P < 0.0001), and pancreatic gland in the control group (1.78 ± 0.07 × 10^–3 mm²/second; P < 0.0005). There was no significant difference of ADC values between the mass‐forming focal pancreatitis and the remaining pancreas (2.03 ± 0.2 × 10^–3 mm²/second; P > 0.05).

Conclusion

Differences on DWI may help to differentiate PC, mass‐forming FP, and normal pancreas from each other. J. Magn. Reson. Imaging 2009;29:350–356. © 2009 Wiley‐Liss, Inc.     

Diffusion-Weighted MR Imaging of Primary and Secondary Lung Cancer: Predictive Value for Response to Transpulmonary Chemoembolization and Transarterial Chemoperfusion

PurposeTo examine predictive value of apparent diffusion coefficient (ADC) in diffusion-weighted imaging (DWI) for response of patients with primary and secondary lung neoplasms undergoing transpulmonary chemoembolization (TPCE) and transarterial chemoperfusion (TACP) treatment.Materials and MethodsThirty-one patients (mean age ± SD 64 ± 12.4 y) with 42 lung target lesions (13 primary and 29 secondary) underwent DWI and subsequent ADC analysis on a 1.5T MR imaging scanner before and 30.3 days ± 6.4 after first session of TPCE or TACP. After 3.1 treatment sessions ± 1.4 performed in 2- to 4-week intervals, morphologic response was analyzed by comparing tumor diameter and volume before and after treatment on unenhanced T1-weighted MR images. On a per-lesion basis, response was classified according to Response Evaluation Criteria In Solid Tumors.ResultsThreshold ADC increase of 20.7% indicated volume response with 88% sensitivity and 78% specificity (area under the curve [AUC] = 0.84). Differences between ADC changes in volume response groups were significant (P = .002). AUC for volume response predicted by ADC before treatment was 0.77. Median ADC before treatment and mean ADC change were 1.09 × 10⁻³ mm²/second and 0.36 × 10⁻³ mm²/second ± 0.23, 1.45 × 10⁻³ mm²/second and 0.14 × 10⁻³ mm²/second ± 0.16, and 1.30 × 10⁻³ mm²/second and 0.06 × 10⁻³ mm²/second ± 0.19 in partial response, stable disease, and progressive disease groups. In primary lung cancer lesions, strong negative correlation of ADC change with change in diameter (ρ = −.87, P < .001) and volume (ρ = −.66, P = .016) was found. In metastases, respective correlation coefficients were ρ = −.18 (P = .356) and ρ = −.35 (P = .061).ConclusionsADC quantification shows considerable diagnostic value for predicting response and monitoring TPCE and TACP treatment of patients with primary and secondary lung neoplasms.     

103Pd放射性支架抑制再狭窄的作用及对平滑肌细胞凋亡基因表达的影响

目的　观察1 0 3Pd放射性支架对兔腹主动脉中膜平滑肌细胞凋亡相关基因Bcl 2及BaxmRNA表达的影响 ,探讨其防治血管成形术后再狭窄的作用机理。方法　将雄性新西兰大白兔 5 0只随机分为普通支架组及1 0 3Pd放射性支架组 ,设正常对照。分别于术后 3、7、14、2 8和 5 6d取材 ,进行病理形态学研究 ,并用原位杂交的方法测定血管中膜平滑肌细胞中Bcl 2mRNA及BaxmRNA的表达。结果　光镜下发现 ,放射性支架组管腔狭窄程度明显低于普通支架组 ,术后第 5 6天最显著(P <0 0 1)。与对照组比较 ,术后 3～ 2 8d普通支架组与放射性支架组Bcl 2mRNA表达均明显增加 ,而放射性支架组的表达则较普通支架组降低 (P <0 0 1)。BaxmRNA的表达 ,术后第 3～ 2 8天两支架组均超过对照组 ,而放射性支架组的表达较普通支架组显著增加 (P <0 0 1)。Bcl 2mRNA与BaxmRNA的比值显示 ,普通支架组术后第 3、14和 2 8天均大于对照组 (P <0 0 1) ,放射性支架组虽也大于对照组 ,但无统计学差异 (P >0 0 5 )。术后第 3～ 2 8天 ,放射性支架组的比值均小于普通支架组(P <0 0 5 )。结论　1 0 3Pd放射性支架增加细胞凋亡的BaxmRNA表达 ,减少抑制细胞凋亡的Bcl 2mRNA表达 ,使凋亡细胞比例增加 ,降低再狭窄的发生     

浓缩铀诱发人白血病细胞凋亡及相关基因调控研究

目的　研究浓缩铀诱发人白血病HL 6 0细胞凋亡的损伤特征及对凋亡相关基因bcl 2和bax的调控作用。方法　研究受浓缩铀内照射不同时间诱发HL 6 0细胞凋亡的DNA凝胶电泳。运用免疫组织化学技术探讨浓缩铀对HL 6 0细胞bcl 2 bax的蛋白表达 ,以及RNA分子杂交技术探讨浓缩铀对HL 6 0细胞bcl 2mRNA的转录水平表达。结果　在浓缩铀作用下 ,HL 6 0细胞的DNA呈现出在核小体间断裂的阶梯状条带形成的凋亡特征 ;并且观察到对照HL 6 0细胞中bcl 2蛋白呈高度表达 ,为 (88± 7) % ,而受浓缩铀辐照后 ,可下调至 (6 1± 5 ) %。bax在对照细胞中的表达很低 ,在浓缩铀作用下 ,未见明显改变。而且受浓缩铀辐照后 ,可使HL 6 0细胞中bcl 2mRNA表达呈明显下调。结论　浓缩铀可诱发HL 6 0细胞凋亡发生 ,其诱发凋亡的程度随浓缩铀作用时间的延长而增加。并且发现浓缩铀诱发人白血病HL 6 0细胞的凋亡作用 ,与其下调凋亡相关基因bcl 2的表达相关联。     

Percutaneous Radiofrequency Lung Ablation Combined with Transbronchial Saline Injection: An Experimental Study in Swine

To evaluate the efficacy of radiofrequency lung ablation with transbronchial saline injection. The bilateral lungs of eight living swine were used. A 13-gauge bone biopsy needle was inserted percutaneously into the lung, and 1 ml of muscle paste was injected to create a tumor mimic. In total, 21 nodules were ablated. In the saline injection group (group A), radiofrequency ablation (RFA) was performed for 11 nodules after transbronchial saline injection under balloon occlusion with a 2-cm active single internally cooled electrode. In the control group (group B), conventional RFA was performed for 10 nodules as a control. The infused saline liquid showed a wedge-shaped and homogeneous distribution surrounding a tumor mimic. All 21 RFAs were successfully completed. The total ablation time was significantly longer (13.4 ± 2.8 min vs. 8.9 ± 3.5 min; P = 0.0061) and the tissue impedance was significantly lower in group A compared with group B (73.1 ± 8.8 Ω vs. 100.6 ± 16.6 Ω; P = 0.0002). The temperature of the ablated area was not significantly different (69.4 ± 9.1°C vs. 66.0 ± 7.9°C; P = 0.4038). There was no significant difference of tumor mimic volume (769 ± 343 mm³ vs. 625 ± 191 mm³; P = 0.2783). The volume of the coagulated area was significantly larger in group A than in group B (3886 ± 1247 mm³ vs. 2375 ± 1395 mm³; P = 0.0221). Percutaneous radiofrequency lung ablation combined with transbronchial saline injection can create an extended area of ablation.     

The predictive value of cardiac morphology for long-term outcome of patients undergoing catheter ablation for atrial fibrillation

ObjectiveCatheter ablation (CA) is an established therapy for selected patients with atrial fibrillation (AF), but predictors of CA ablation outcome are still not fully elucidated. The aim of the study was to identify structural and morphological parameters from computed tomography (CT) as predictors of successful CA of AF in a single center prospective cohort.MethodsAn analysis of CT scans dedicated to LA evaluation was performed in 99 patients (63 ± 8 years old, 70% males, 59% paroxysmal AF) scheduled for CA of AF. Survival free of atrial fibrillation/flutter/tachycardia at 1- and 3-years was assessed.ResultsIn overall study population, both 1- and 3-year responders had smaller distance to the first division in left superior pulmonary vein (16.3 ± 5.42 mm vs. 19.1 ± 7.0 mm and 14.9 ± 3.6 mm vs. 18.7 ± 7.0 mm; p < 0.05). One-year responders had larger ostium area of left inferior pulmonary vein (median 236 mm² [IQR = 97] vs. 222 mm² [IQR = 71]; p = 0.03) and less acute angle between the interatrial septum and the right superior pulmonary vein (102 ± 20° vs. 95 ± 10°; p = 0.03). Three-years' responders had smaller ostium area of the right superior pulmonary vein (248 ± 94 mm² vs. 364 ± 282 mm²; p = 0.02). Multivariate Cox regression analysis identified different predictors in paroxysmal and non-paroxysmal AF. For patients with paroxysmal AF, the predictors were angle to right superior pulmonary vein and left superior/inferior pulmonary veins carina thickness with hazard ratios of 0.965 (95%CI 0.939 to 0.992, p = 0.010) and 0.747 (95%CI 0.591 to 0.944, p = 0.015). In patients with persistent AF, the predictors were gender and NYHA stage with hazard ratios of 4.9 (95%CI 1.758 to 13.579, p = 0.002) and 0.365 (95%CI 0.148 to 0.899, p = 0.028) respectively.ConclusionsThe anatomy of LA, especially morphology of pulmonary veins, seems to be one of the predictors of clinical outcome after CA for paroxysmal AF. In non-paroxysmal AF LA anatomy is less relevant in prediction of clinical outcome.     

Longitudinal assessment of coronary plaque volume change related to glycemic status using serial coronary computed tomography angiography: A PARADIGM (Progression of AtheRosclerotic PlAque DetermIned by Computed TomoGraphic Angiography Imaging) substudy

BackgroundData on the impact of glycemic status on coronary plaque progression have been limited. This study evaluated the association between glycemic status and coronary plaque volume change (PVC) using coronary computed tomography angiography (CCTA).MethodsA total of 1296 subjects (61 ± 9, 56.9% male) who underwent serial CCTA with available glycemic status were enrolled and analyzed from the Progression of AtheRosclerotic PlAque DetermIned by Computed TomoGraphic Angiography IMaging (PARADIGM) registry. The median inter-scan period was 3.2 (2.6–4.4) years. Quantitative assessment of coronary plaques was performed at both scans. All participants were categorized into the following groups according to glycemic status: normal, pre-diabetes (pre-DM), and diabetes mellitus (DM).ResultsDuring the follow-up, significant differences in PVC (normal: 51.3 ± 83.3 mm³ vs. pre-DM: 51.0 ± 84.3 mm³ vs. DM: 72.6 ± 95.0 mm³; p < 0.001) and annualized PVC (normal: 14.9 ± 24.9 mm³ vs. pre-DM: 15.7 ± 23.8 mm³ vs. DM: 21.0 ± 27.7 mm³; p = 0.001) were observed among the 3 groups. Compared with normal individuals, individuals with pre-DM showed no significant differences in the adjusted odds ratio (OR) for plaque progression (PP) (1.338, 95% confidence interval [CI] 0.967–1.853; p = 0.079). However, the adjusted OR for PP was higher in DM individuals than in normal individuals (1.635, 95% CI 1.126–2.375; p = 0.010).ConclusionDM had an incremental impact on coronary PP, but pre-DM appeared to have no significant association with an increased risk of coronary PP after adjusting for confounding factors.Clinical trial registrationClinicalTrials.gov NCT02803411.