Lower gastrointestinal bleeding:Role of 64-row computed tomographic angiography in diagnosis and therapeutic planning

AIM: To determine the value of computed tomographic angiography(CTA) for diagnosis and therapeutic planning in lower gastrointestinal(GI) bleeding.METHODS: Sixty-three consecutive patients with acute lower GI bleeding underwent CTA before endovascular or surgical treatment. CTA was used to determine whether the lower GI bleeding was suitable for endovascular treatment, surgical resection, or conservative treatment in each patient. Treatment planning with CTA was compared with actual treatment decisions or endovascular or surgical treatment that had been carried out in each patient based on CTA findings.RESULTS: 64-row CTA detected active extravasation of contrast material in 57 patients and six patients had no demonstrable active bleeding, resulting in an accuracy of 90.5% in the detection of acute GI bleeding(57 of 63). In three of the six patients with no demonstrable active bleeding, active lower GI bleeding recurred within one week after CTA, and angiography revealed acute bleeding. The overall location-based accuracy, sensitivity, specificity, positive predictive value(PPV) and negative predictive value(NPV) for the detection of GI bleeding by 64-row CTA were 98.8%(249 of 252), 95.0%(57 of 60), 100%(192 of 192), 100%(57 of 57), and 98.5%(192 of 195), respectively. Treatment planning was correctly established on the basis of 64-row CTA with an accuracy, sensitivity, specificity, PPV and NPV of 98.4%(248 of 252), 93.3%(56 of 60), 100%(192 of 192), 100%(56 of 56), and 97.5%(192 of 196), respectively, in a location-based evaluation. CONCLUSION: 64-row CTA is safe and effective in making decisions regarding treatment, without performing digital subtraction angiography or surgery, in the majority of patients with lower GI bleeding.

基于SPR技术的抗CD80生物技术药物结合活性方法的建立

目的基于表面等离子共振(SPR)技术建立抗CD80生物技术药物结合活性方法,并进行方法学验证和样品测定。方法通过优化试验条件建立合适的结合活性方法,并选择合适的数据分析模型后对建立的方法进行方法学验证。结果通过对各种条件进行筛选及耐用性考察,确定了方法的试验参数:配体固定条件为pH 5.0的醋酸盐缓冲液,固定量为400~5000 RU,结合和解离速率为10~50μL·min^(-1),芯片的再生条件为pH 4.0的枸橼酸缓冲液(10 mmol·L^(-1)枸橼酸钠,100 mmol·L^(-1)NaCl),响应参数为稳态相对响应值(在进样结束后10 s范围内窗口的平均响应值),数据模型为四参数模型。根据以上参数建立了基于SPR技术抗CD80生物技术药物结合活性方法。验证结果如下:线性回归方程的决定系数为0.9994;每个效价水平相对效价测定值的相对偏倚平均值为-0.66%~0.64%,线性回归方程的斜率为0.9867;每个效价水平6次独立测试结果的几何变异系数为0.7%~1.5%,范围为64%~156%。各项验证指标均满足相关验证要求,专属性结果也较好。将建立的结合活性方法应用于抗CD80生物技术药物,测得结合活性相对效价为100%。结论本研究通过优化试验条件建立了基于SPR技术的抗CD80生物技术药物结合活性方法,该方法专属性强、重复性好、准确度高。