目的探析T2加权成像(T_(2)WI)联合扩散加权成像(DWI)用于直肠诊断及术前分期的效能及其相对表观扩散系数(rADC)、表观扩散系数(ADC)值与患者临床特征的相关性。方法选择疑似直肠癌患者212例,其中男性118例,女性94例;年龄42~83岁,平均年...目的探析T2加权成像(T_(2)WI)联合扩散加权成像(DWI)用于直肠诊断及术前分期的效能及其相对表观扩散系数(rADC)、表观扩散系数(ADC)值与患者临床特征的相关性。方法选择疑似直肠癌患者212例,其中男性118例,女性94例;年龄42~83岁,平均年龄60.93岁;病程3个月~10年,平均病程5.64年。均行T_(2)WI联合DWI检查,以患者最终病理诊断结果为标准,计算T_(2)WI联合DWI对直肠癌的诊断效能,进行T、N分期诊断;以最终病理诊断结果为依据,计算其T、N分期诊断效能,并进行一致性检验;观察不同临床特征的患者间rADC、ADC值差异,绘制受试者工作特性(ROC)曲线,计算rADC、ADC值对直肠癌的诊断效能。结果术后病理诊断恶性172例,良性40例。T1期、T2期、T3期、T4期分别为8例、35例、31例、6例,N0期、N1期、N2期分别为37例、22例、21例。T_(2)WI联合DWI诊断直肠癌的准确度为92.45%,灵敏度为93.02%,特异度为90.00%;分期诊断中T1期、T2期、T3期、T4期诊断准确度为95.00%、93.75%、96.26%、95.00%,灵敏度为75.00%、94.12%、93.55%、71.43%,特异度为97.22%、95.65%、95.92%、97.26%。一致性检验显示T_(2)WI联合DWI与病理诊断结果的T分期诊断一致性较好(Kappa=0.863,P=0.000);N分期诊断中N0期、N1期、N2期诊断准确度分别为93.75%、90.00%、96.25%,灵敏度分别为94.59%、77.27%、95.24%,特异度分别为93.02%、94.83%、96.61%,一致性检验提示T_(2)WI联合DWI与病理诊断的N分期诊断一致性较好(Kappa=0.844,P=0.000);病变特征与rADC、ADC分析中,恶性病变rADC、ADC显著低于良性病变(0.84±0.09 vs 1.18±0.12、0.93±0.11 vs 1.39±0.11。P<0.05)。腺癌rADC、ADC显著高于黏液腺癌(0.89±0.11 vs 0.75±0.09、0.97±0.14 vs 0.83±0.11。P<0.05)。不同分化程度患者间rADC、ADC从高至低依次为高分化、中分化、低分化(rADC:0.95±0.16 vs 0.82±0.10 vs 0.72±0.08;ADC:1.05±0.17 vs 0.911±0.14 vs 0.81±0.09。P<0.05)。ADC诊断直肠癌AUC为0.987,灵敏度为92.44%,特异度为97.50%(P<0.001);rADC诊断结直肠癌AUC为0.941,灵敏度为92.44%,特异度为87.50%(P<0.001)。结论T_(2)WI联合DWI诊断直肠癌具有良好的诊断效能,且其术前T、N分期准确度高,与病理诊断一致性较好。rADC、ADC值在不同良恶性肿瘤、不同分化等级肿瘤、不同病理类型肿瘤间存显著差异,可作为良恶性及肿瘤分化程度的诊断依据。展开更多
目的:探讨瘤周水肿区表观扩散系数值(ADC)及相对表观扩散系数(rADC)在高级别胶质瘤及脑转移瘤鉴别诊断中的价值。方法:收集行常规MRI及DWI检查的20例高级别胶质瘤(其中3例为术后复发)与21例脑转移瘤,将瘤周1cm范围内作为感兴趣区ROI(reg...目的:探讨瘤周水肿区表观扩散系数值(ADC)及相对表观扩散系数(rADC)在高级别胶质瘤及脑转移瘤鉴别诊断中的价值。方法:收集行常规MRI及DWI检查的20例高级别胶质瘤(其中3例为术后复发)与21例脑转移瘤,将瘤周1cm范围内作为感兴趣区ROI(region of interest)测量ADC值,并计算相应的rADC值。结果:高级别胶质瘤瘤周水肿带的ADC值和rADC值分别为(1.25×10^(-3)±0.14×10^(-3))mm^2/s和1.75±0.21。脑转移瘤瘤周水肿带的ADC值和rADC值分别为(1.56×10^(-3)±0.21×10^(-3))mm^2/s和2.22±0.37,两者差异有统计学意义。结论:测量高级别胶质瘤与脑转移瘤近瘤周水肿区ADC值及rADC值对二者鉴别诊断具有一定的价值。展开更多
RecA family recombinases play essential roles in maintaining genome integrity. A group of RecA-like proteins named RadC are present in all archaea, but their in vivo functions remain unclear. In this study, we perform...RecA family recombinases play essential roles in maintaining genome integrity. A group of RecA-like proteins named RadC are present in all archaea, but their in vivo functions remain unclear. In this study, we performed phylogenetic and genetic analysis of two RadC proteins from Sulfolobus islandicus. RadC is closer to the KaiC lineage of cyanobacteria and proteobacteria than to the lineage of the recombinases （RecA, RadA, and Rad51） and the recombinase paralogs （e.g., RadB, Rad55, and Rad51B）. Using the recently- established S. islandicus genetic system, we constructed deletion and over-expression strains of radC1 and radC2. Deletion of radC1 rendered the cells more sensitive to DNA damaging agents, methyl methanesulfonate （MMS）, hydroxyurea （HU）, and ultraviolet （UV） radiation, than the wild type, and a AradCIAradC2 double deletion strain was more sensitive to cisplatin and MMS than the AradC1 single deletion mutant. In addition, ectopic expression of His-tagged RadC 1 revealed that RadC I was co-purified with a putative structure-specific nuclease and ATPase, which is highly conserved in archaea. Our results indicate that both RadCI and RadC2 are involved in DNA repair. RadCl may play a general or primary role in DNA repair, while RadC2 plays a role in DNA repair in response to specific DNA damages.展开更多
文摘目的探析T2加权成像(T_(2)WI)联合扩散加权成像(DWI)用于直肠诊断及术前分期的效能及其相对表观扩散系数(rADC)、表观扩散系数(ADC)值与患者临床特征的相关性。方法选择疑似直肠癌患者212例,其中男性118例,女性94例;年龄42~83岁,平均年龄60.93岁;病程3个月~10年,平均病程5.64年。均行T_(2)WI联合DWI检查,以患者最终病理诊断结果为标准,计算T_(2)WI联合DWI对直肠癌的诊断效能,进行T、N分期诊断;以最终病理诊断结果为依据,计算其T、N分期诊断效能,并进行一致性检验;观察不同临床特征的患者间rADC、ADC值差异,绘制受试者工作特性(ROC)曲线,计算rADC、ADC值对直肠癌的诊断效能。结果术后病理诊断恶性172例,良性40例。T1期、T2期、T3期、T4期分别为8例、35例、31例、6例,N0期、N1期、N2期分别为37例、22例、21例。T_(2)WI联合DWI诊断直肠癌的准确度为92.45%,灵敏度为93.02%,特异度为90.00%;分期诊断中T1期、T2期、T3期、T4期诊断准确度为95.00%、93.75%、96.26%、95.00%,灵敏度为75.00%、94.12%、93.55%、71.43%,特异度为97.22%、95.65%、95.92%、97.26%。一致性检验显示T_(2)WI联合DWI与病理诊断结果的T分期诊断一致性较好(Kappa=0.863,P=0.000);N分期诊断中N0期、N1期、N2期诊断准确度分别为93.75%、90.00%、96.25%,灵敏度分别为94.59%、77.27%、95.24%,特异度分别为93.02%、94.83%、96.61%,一致性检验提示T_(2)WI联合DWI与病理诊断的N分期诊断一致性较好(Kappa=0.844,P=0.000);病变特征与rADC、ADC分析中,恶性病变rADC、ADC显著低于良性病变(0.84±0.09 vs 1.18±0.12、0.93±0.11 vs 1.39±0.11。P<0.05)。腺癌rADC、ADC显著高于黏液腺癌(0.89±0.11 vs 0.75±0.09、0.97±0.14 vs 0.83±0.11。P<0.05)。不同分化程度患者间rADC、ADC从高至低依次为高分化、中分化、低分化(rADC:0.95±0.16 vs 0.82±0.10 vs 0.72±0.08;ADC:1.05±0.17 vs 0.911±0.14 vs 0.81±0.09。P<0.05)。ADC诊断直肠癌AUC为0.987,灵敏度为92.44%,特异度为97.50%(P<0.001);rADC诊断结直肠癌AUC为0.941,灵敏度为92.44%,特异度为87.50%(P<0.001)。结论T_(2)WI联合DWI诊断直肠癌具有良好的诊断效能,且其术前T、N分期准确度高,与病理诊断一致性较好。rADC、ADC值在不同良恶性肿瘤、不同分化等级肿瘤、不同病理类型肿瘤间存显著差异,可作为良恶性及肿瘤分化程度的诊断依据。
文摘目的:探讨瘤周水肿区表观扩散系数值(ADC)及相对表观扩散系数(rADC)在高级别胶质瘤及脑转移瘤鉴别诊断中的价值。方法:收集行常规MRI及DWI检查的20例高级别胶质瘤(其中3例为术后复发)与21例脑转移瘤,将瘤周1cm范围内作为感兴趣区ROI(region of interest)测量ADC值,并计算相应的rADC值。结果:高级别胶质瘤瘤周水肿带的ADC值和rADC值分别为(1.25×10^(-3)±0.14×10^(-3))mm^2/s和1.75±0.21。脑转移瘤瘤周水肿带的ADC值和rADC值分别为(1.56×10^(-3)±0.21×10^(-3))mm^2/s和2.22±0.37,两者差异有统计学意义。结论:测量高级别胶质瘤与脑转移瘤近瘤周水肿区ADC值及rADC值对二者鉴别诊断具有一定的价值。
基金supported by the grants from the National Natural Science Foundation of China(Nos.3093002 and 31170072) to Y.SDanish Council of Independent Research(No.FTP/11-106683) to Q.S
文摘RecA family recombinases play essential roles in maintaining genome integrity. A group of RecA-like proteins named RadC are present in all archaea, but their in vivo functions remain unclear. In this study, we performed phylogenetic and genetic analysis of two RadC proteins from Sulfolobus islandicus. RadC is closer to the KaiC lineage of cyanobacteria and proteobacteria than to the lineage of the recombinases （RecA, RadA, and Rad51） and the recombinase paralogs （e.g., RadB, Rad55, and Rad51B）. Using the recently- established S. islandicus genetic system, we constructed deletion and over-expression strains of radC1 and radC2. Deletion of radC1 rendered the cells more sensitive to DNA damaging agents, methyl methanesulfonate （MMS）, hydroxyurea （HU）, and ultraviolet （UV） radiation, than the wild type, and a AradCIAradC2 double deletion strain was more sensitive to cisplatin and MMS than the AradC1 single deletion mutant. In addition, ectopic expression of His-tagged RadC 1 revealed that RadC I was co-purified with a putative structure-specific nuclease and ATPase, which is highly conserved in archaea. Our results indicate that both RadCI and RadC2 are involved in DNA repair. RadCl may play a general or primary role in DNA repair, while RadC2 plays a role in DNA repair in response to specific DNA damages.
