目的通过磁共振扩散峰度成像(diffusion kurtosis imaging,DKI)预测WHOⅡ级脑胶质瘤异柠檬酸脱氢酶(isocitrate dehydrogenase,IDH)基因状态。材料与方法收集经病理证实的25例WHOⅡ级脑胶质瘤患者的临床、影像资料,患者术前均行常规MRI...目的通过磁共振扩散峰度成像(diffusion kurtosis imaging,DKI)预测WHOⅡ级脑胶质瘤异柠檬酸脱氢酶(isocitrate dehydrogenase,IDH)基因状态。材料与方法收集经病理证实的25例WHOⅡ级脑胶质瘤患者的临床、影像资料,患者术前均行常规MRI及DKI扫描,测量肿瘤实质区、水肿区、同层面对侧正常脑白质(normal appearing white matter,NAWM)的DKI参数扩散各项异性分数(fractional anisotropy,FA)、平均扩散系数(mean diffusivity,MD)、平均扩散峰度(mean kurtosis,MK)、轴向扩散峰度(axial kurtosis,Ka)、径向扩散峰度(radial kurtosis,Kr),并对DKI参数校正处理,得到相对扩散各项异性分数(ratio of FA,rFA)、相对平均扩散系数(ratio of MD,rMD)、相对平均扩散峰度(ratio of MK,rMK)、相对轴向扩散峰度(ratio of Ka,rKa)、相对径向扩散峰度(ratio of Kr,rKr)值(肿瘤区、水肿区参数值除以对侧NAWM)。术后标本制作蜡块行Sanger基因测序分析。25例分为IDH突变型16例,IDH野生型9例,应用两独立样本t检验分析校正后两组DKI参数差异,受试者工作特征(receiver operating characteristic,ROC)曲线分析各参数值的诊断价值。结果 IDH野生型肿瘤实质区rFA值、rMK值均高于IDH突变型,而rMD值低于IDH突变型,两者之间差异有统计学意义(P<0.05);两组病例瘤周水肿各参数值差异无统计学意义。瘤体rMK值ROC曲线下面积为75.7%,当截点取0.515时,敏感性为77.8%。特异性为68.7%;rFA值ROC曲线下面积为72.9%,当截点取0.527时,敏感性为66.7%。特异性为93.7%;rMD值ROC曲线下面积为75.7%,当截点取1.261时,敏感性为87.5%。特异性为66.7%。结论 WHOⅡ级脑胶质瘤瘤体rMK、rFA、rMD值有助于判断IDH基因状态,并且rMK与rMD的敏感性及特异性均较高。展开更多
The plant NAD-dependent isocitrate dehydro-genase (NAD-IDH) is an important multifunctional enzyme. The cDNAs encoding three different subunits of the NAD-IDH were cloned successfully from leaves of Arabidop-sis thali...The plant NAD-dependent isocitrate dehydro-genase (NAD-IDH) is an important multifunctional enzyme. The cDNAs encoding three different subunits of the NAD-IDH were cloned successfully from leaves of Arabidop-sis thaliana ecotype Columbia gl1 and three lines (Shaan 2A, Shaan 2B and Ken C1) of Brassica napus by RT-PCR method. By searching the sequences in GenBank Database, it is shown that these sequences from B. napus were novel. Their encoding regions of a functional protein were then inserted into the multiple cloning sites of pMID1 vector for the expression of recombinant protein. All the recombinants were successfully expressed in the in vitro expression system. When the transcripts of subunits 0, 1 and 2 were added to-gether to the in vitro system with 36 靏/mL of protein disul-fide isomerase, the expressed products had NAD-IDH enzy-matic activity. Comparison of different kinds of gene and molecular ratio of the transcripts showed that the NAD-IDH enzyme is composed of three subunits designated subunit 0, subunit 1 and subunit 2. All the three subunits are essential to catalytic activity. Missing subunit 0 could abolish activity. Missing either subunit 1 or subunit 2 would cause severe impact on activity. Deletions, which would cause frameshift mutation or nonsense mutation, were also found in some transcripts of subunit 1 gene from Shaan 2A and Shaan 2B of B. napus. The mutated subunit 1 lost its proper function. This may explain why there is difference of the NAD-IDH activity among three lines of B. napus.展开更多
文摘目的通过磁共振扩散峰度成像(diffusion kurtosis imaging,DKI)预测WHOⅡ级脑胶质瘤异柠檬酸脱氢酶(isocitrate dehydrogenase,IDH)基因状态。材料与方法收集经病理证实的25例WHOⅡ级脑胶质瘤患者的临床、影像资料,患者术前均行常规MRI及DKI扫描,测量肿瘤实质区、水肿区、同层面对侧正常脑白质(normal appearing white matter,NAWM)的DKI参数扩散各项异性分数(fractional anisotropy,FA)、平均扩散系数(mean diffusivity,MD)、平均扩散峰度(mean kurtosis,MK)、轴向扩散峰度(axial kurtosis,Ka)、径向扩散峰度(radial kurtosis,Kr),并对DKI参数校正处理,得到相对扩散各项异性分数(ratio of FA,rFA)、相对平均扩散系数(ratio of MD,rMD)、相对平均扩散峰度(ratio of MK,rMK)、相对轴向扩散峰度(ratio of Ka,rKa)、相对径向扩散峰度(ratio of Kr,rKr)值(肿瘤区、水肿区参数值除以对侧NAWM)。术后标本制作蜡块行Sanger基因测序分析。25例分为IDH突变型16例,IDH野生型9例,应用两独立样本t检验分析校正后两组DKI参数差异,受试者工作特征(receiver operating characteristic,ROC)曲线分析各参数值的诊断价值。结果 IDH野生型肿瘤实质区rFA值、rMK值均高于IDH突变型,而rMD值低于IDH突变型,两者之间差异有统计学意义(P<0.05);两组病例瘤周水肿各参数值差异无统计学意义。瘤体rMK值ROC曲线下面积为75.7%,当截点取0.515时,敏感性为77.8%。特异性为68.7%;rFA值ROC曲线下面积为72.9%,当截点取0.527时,敏感性为66.7%。特异性为93.7%;rMD值ROC曲线下面积为75.7%,当截点取1.261时,敏感性为87.5%。特异性为66.7%。结论 WHOⅡ级脑胶质瘤瘤体rMK、rFA、rMD值有助于判断IDH基因状态,并且rMK与rMD的敏感性及特异性均较高。
文摘The plant NAD-dependent isocitrate dehydro-genase (NAD-IDH) is an important multifunctional enzyme. The cDNAs encoding three different subunits of the NAD-IDH were cloned successfully from leaves of Arabidop-sis thaliana ecotype Columbia gl1 and three lines (Shaan 2A, Shaan 2B and Ken C1) of Brassica napus by RT-PCR method. By searching the sequences in GenBank Database, it is shown that these sequences from B. napus were novel. Their encoding regions of a functional protein were then inserted into the multiple cloning sites of pMID1 vector for the expression of recombinant protein. All the recombinants were successfully expressed in the in vitro expression system. When the transcripts of subunits 0, 1 and 2 were added to-gether to the in vitro system with 36 靏/mL of protein disul-fide isomerase, the expressed products had NAD-IDH enzy-matic activity. Comparison of different kinds of gene and molecular ratio of the transcripts showed that the NAD-IDH enzyme is composed of three subunits designated subunit 0, subunit 1 and subunit 2. All the three subunits are essential to catalytic activity. Missing subunit 0 could abolish activity. Missing either subunit 1 or subunit 2 would cause severe impact on activity. Deletions, which would cause frameshift mutation or nonsense mutation, were also found in some transcripts of subunit 1 gene from Shaan 2A and Shaan 2B of B. napus. The mutated subunit 1 lost its proper function. This may explain why there is difference of the NAD-IDH activity among three lines of B. napus.
