Objective: To study the feasibility of ultrasonic molecular imaging of immediately blood-mediated inflammatory reaction (IBMIR) in vitro.
Methods: IBMIR models in vitro were divided into 3 groups: Group A, no microbubbles were added; Group B, non-targeted micro-bubbles were added; Group C, Lys-Gly-Asp-Ser (KGDS)-targeted microbubbles (MBK) were added. The ultrasonic enhancement of IBMIR in loops by ultrasonic contrast imaging was evaluated.
Results: The contrast-enhanced US imaging did not show thrombus formation in the group A, whereas the thrombus was found in the Group B and C with a change in filling defects or ring enhancement, respectively. The time for detecting thrombosis was (7.3 ± 0.5) min and (13.2 ± 0.6) min in Group B and Group C, respectively (P<0.05). The average-gray scales of thrombus in Group B and Group C were 31.22 ± 3.56 and 75.85 ± 5.21, respectively (P<0.05). The fluorescence microscope also showed that MBK was attached to thrombus surrounding islets.
Conclusion: IBMIR model in vitro showed that KGDS-targeted ultrasound contrast agent could adhere to thrombus shell surrounding islets and molecular target ultrasonography could image these thrombi noninvasively and effectively.
目的：探讨采用赖氨酸-甘氨酸-天冬氨酸-丝氨酸(Lys-Gly-Asp-Ser，KGDS)血栓靶向超声造影剂显示体外胰岛移植立即经血液介导的炎症反应(immediately blood-mediated inflammatory reaction，IBMIR)可行性，为无创、实时、动态地研究和评价IBMIR探索一种新的分子影像学方法。方法：7 mL新鲜全血+1 000 胰岛当量(islet equivalent quantity，IEQ)新生猪胰岛体外制作IBMIR模型。实验分为3组，均重复3次：A组对照组，不加造影剂；B组加普通超声造影剂；C组加靶向超声造影剂。将上述各组Loops管道固定于摇床，并浸于37 ℃的水浴中。采用超声造影模式实时观察Loops管内的回声，记录超声发现血栓出现的时间；并采用Line成像模式存储在硬盘，脱机分析血栓超声增强强度。实验开始后10，30，60 min 3个时间点，经70 μm过滤网过滤Loops管内血液，测定过滤液体的凝血系统[凝血酶抗凝血酶复合物(thrombin-antithrombin complex，ATA)，D-二聚体(D-dimer)]、补体系统(C3a，C5b-9)及胰岛素含量等指标，过滤网内血块做病理学检测。结果：A组没有加入造影剂，超声不能发现血栓形成；B组、C组加入超声造影剂后超声可以发现血栓，其中B组加入自制普通超声造影剂，血栓在超声图像上显示为周边及内部无增强，呈充盈缺损改变，发现血栓时间为(7.3±0.5) min，相应血栓超声增强强度的灰阶值为31.22±3.56；C组加入靶向超声造影剂，超声清晰显示环状增强的血栓，发现血栓时间为(13.2±0.6) min，其超声增强强度的灰阶值为75.85±5.21。B组、C组血栓灰阶值及发现时间比较差异均有统计学意义(P<0.05)。血液学检测证实各实验组均发生了IBMIR；病理结果显示胰岛与新鲜全血接触后，其表面形成血栓壳，加入带荧光的靶向超声造影剂，荧光显微镜可以清楚观察到胰岛周边呈明亮的荧光光环，与血栓壳位置、形态、范围完全吻合。结论：超声分子影像技术可以靶向显像体外IBMIR，为无创评估IBMIR的发生及其范围、程度提供了可能。.