Some in vitro experiments have shown that erythropoietin （EPO） increases resistance to apoptosis and facilitates neuronal survival follow- ing cerebral ischemia. However, results from in vivo studies are rarely repo...Some in vitro experiments have shown that erythropoietin （EPO） increases resistance to apoptosis and facilitates neuronal survival follow- ing cerebral ischemia. However, results from in vivo studies are rarely reported. Perfusion-weighted imaging （PWI） and diffusion-weighted imaging （DWI） have been applied successfully to distinguish acute cerebral ischemic necrosis and penumbra in living animals; therefore, we hypothesized that PWI and DWI could be used to provide imaging evidence in vivo for the conclusion that EPO could reduce apoptosis in brain areas injured by cerebral ischemia/reperfusion. To validate this hypothesis, we established a rat model of focal cerebral ischemia/ reperfusion injury, and treated with intra-cerebroventricular injection of EPO （5,000 U/kg） 20 minutes before injury. Brain tissue in the ischemic injury zone was sampled using MRI-guided localization. The relative area of abnormal tissue, changes in PWI and DWI in the ischemic injury zone, and the number of apoptotic cells based on TdT-mediated dUTP-biotin nick end-labeling （TUNEL） were assessed. Our findings demonstrate that EPO reduces the relative area of abnormally high signal in PWI and DWI, increases cerebral blood volume, and decreases the number of apoptotic cells positive for TUNEL in the area injured by cerebral ischemia/reperfusion. The experiment pro- vides imaging evidence in vivo for EPO treating cerebral ischemia/reperfusion injury.展开更多
目的探讨螺旋CT灌注成像在鼻咽癌放疗后局部复发诊断及定量分析中的应用价值。方法选取2013年1月~2015年1月于本院行鼻咽癌放疗的患者96例,根据治疗后鼻咽镜病理活检结果将患者分为复发组（n=46）、放疗后改变组（n=32）及无改变组（n=1...目的探讨螺旋CT灌注成像在鼻咽癌放疗后局部复发诊断及定量分析中的应用价值。方法选取2013年1月~2015年1月于本院行鼻咽癌放疗的患者96例,根据治疗后鼻咽镜病理活检结果将患者分为复发组（n=46）、放疗后改变组（n=32）及无改变组（n=18）,对所有患者进行螺旋CT灌注成像检查,比较3组患者的CT灌注成像参数,主要包括血容量（BV）、血流量（BF）、表面通透性（PS）、平均通过时间（MTT）,并根据ROC曲线分析BF、PS数值对诊断鼻咽癌放疗后局部复发的最佳临界值。结果 3组患者CT灌注成像参数比较结果显示,BF、BV、PS数值存在显著差异（P〈0.05）;复发组与放疗后改变组的MTT指标比较无显著差异（P〉0.05）,与无改变组比较存在显著差异（P〈0.05）;BF、BV、PS的ROC曲线面积分别为0.899、0.935、0.778,BF、BV、PS最佳临界值分别为335.49 m L/100 g·min、10.20 m L/100 g、17.35 m L/100 g·min,灵敏度分别为93.5%、96.8%、82.0%,特异度分别为76.5%、82.4%、60.8%。结论采用螺旋CT灌注成像诊断鼻咽癌放疗后局部复发准确率较高,可根据局部组织灌注参数进行定量或半定量分析,对指导临床治疗及提高患者生存率具有重要意义。展开更多
文摘Some in vitro experiments have shown that erythropoietin （EPO） increases resistance to apoptosis and facilitates neuronal survival follow- ing cerebral ischemia. However, results from in vivo studies are rarely reported. Perfusion-weighted imaging （PWI） and diffusion-weighted imaging （DWI） have been applied successfully to distinguish acute cerebral ischemic necrosis and penumbra in living animals; therefore, we hypothesized that PWI and DWI could be used to provide imaging evidence in vivo for the conclusion that EPO could reduce apoptosis in brain areas injured by cerebral ischemia/reperfusion. To validate this hypothesis, we established a rat model of focal cerebral ischemia/ reperfusion injury, and treated with intra-cerebroventricular injection of EPO （5,000 U/kg） 20 minutes before injury. Brain tissue in the ischemic injury zone was sampled using MRI-guided localization. The relative area of abnormal tissue, changes in PWI and DWI in the ischemic injury zone, and the number of apoptotic cells based on TdT-mediated dUTP-biotin nick end-labeling （TUNEL） were assessed. Our findings demonstrate that EPO reduces the relative area of abnormally high signal in PWI and DWI, increases cerebral blood volume, and decreases the number of apoptotic cells positive for TUNEL in the area injured by cerebral ischemia/reperfusion. The experiment pro- vides imaging evidence in vivo for EPO treating cerebral ischemia/reperfusion injury.
文摘目的探讨螺旋CT灌注成像在鼻咽癌放疗后局部复发诊断及定量分析中的应用价值。方法选取2013年1月~2015年1月于本院行鼻咽癌放疗的患者96例,根据治疗后鼻咽镜病理活检结果将患者分为复发组（n=46）、放疗后改变组（n=32）及无改变组（n=18）,对所有患者进行螺旋CT灌注成像检查,比较3组患者的CT灌注成像参数,主要包括血容量（BV）、血流量（BF）、表面通透性（PS）、平均通过时间（MTT）,并根据ROC曲线分析BF、PS数值对诊断鼻咽癌放疗后局部复发的最佳临界值。结果 3组患者CT灌注成像参数比较结果显示,BF、BV、PS数值存在显著差异（P〈0.05）;复发组与放疗后改变组的MTT指标比较无显著差异（P〉0.05）,与无改变组比较存在显著差异（P〈0.05）;BF、BV、PS的ROC曲线面积分别为0.899、0.935、0.778,BF、BV、PS最佳临界值分别为335.49 m L/100 g·min、10.20 m L/100 g、17.35 m L/100 g·min,灵敏度分别为93.5%、96.8%、82.0%,特异度分别为76.5%、82.4%、60.8%。结论采用螺旋CT灌注成像诊断鼻咽癌放疗后局部复发准确率较高,可根据局部组织灌注参数进行定量或半定量分析,对指导临床治疗及提高患者生存率具有重要意义。
