Comparison between self‐assembling peptide nanofiber scaffold (SAPNS) and fibrin sealant in neurosurgical hemostasis

RADA16‐I is a synthetic type I self‐assembling peptide nanofiber scaffold (SAPNS) which may serve as a novel biocompatible hemostatic agent. Its application in neurosurgical hemostasis, however, has not been explored. Although RADA16‐I is nontoxic and nonimmunogenic, its intrinsic acidity may potentially provoke inflammation in the surgically injured brain. We conducted an animal study to compare RADA16‐I with fibrin sealant, a commonly used agent, with the hypothesis that the former would be a comparable alternative. Using a standardized surgical brain injury model, 30 Sprague–Dawley rats were randomized into three treatment groups: RADA16‐I, fibrin sealant or gelatin sponge (control). Animals were sacrificed on day 3 and 42. Astrocytic and microglial infiltrations within the cerebral parenchyma adjacent to the operative site were significantly lower in the RADA16‐I and fibrin sealant groups than control. RADA16‐I did not cause more cellular inflammatory response despite its acidity when compared with fibrin sealant. Immunohistochemical studies showed infiltration by astrocytes and microglia into the fibrin sealant and RADA16‐I grafts, suggesting their potential uses as tissue scaffolds. RADA16‐I is a promising candidate for further translational and clinical studies that focus on its applications as a safe and effective hemostat, proregenerative nanofiber scaffold as well as drug and cell carrier.     

图形翻转视觉诱发电位在视神经管减压后视神经损伤不同时期的变化特征

目的:观察视神经损伤动物模型在损伤后和不同时期视神经管减压后视觉诱发电位的变化,了解创伤性视神经损伤的手术时机与疗效的关系。方法:实验于2005-03/05在解放军南京军区南京总医院动物实验中心完成。①实验分组:30只新西兰白兔随机分为正常对照组、术后2d减压组、术后7d减压组、术后14d减压组、术后不减压组,每组6只。②造模:除正常对照组外,其余各组在视神经孔中塞入一细端为2mm直径的圆锥软硅胶,阻塞视神经孔,造成视神经的挤压伤。③指标检测:采用图形翻转视觉诱发电位检测损伤前、损伤后1h、减压前1h、减压后2周视功能变化,记录NPN曲线主波(P波)的绝对潜伏期、绝对波幅。正常对照组仅采集一组数据作为对照。结果:30只实验动物均进入结果分析。①正常对照组家兔图形翻转视觉诱发电位检查均引出典型NPN波型曲线,视神经挤压伤后1hNPN波形低阔扁平,P波潜伏期延长,波幅降低。②P波潜伏期:术后2d减压组减压后短于减压前[(71.25±8.51),(86.47±14.28)ms,P<0.05];术后7d减压组减压前后比较差异无显著性(P>0.05);术后14d减压组减压后明显长于减压前[(158.73±15.16),(116.35±17.13)ms,P<0.05]。术后2d减压组和术后7d减压组短于术后不减压组(P<0.01)。术后7,14d减压组和术后不减压组明显长于正常对照组(P<0.01)。③P波波幅:术后2d减压组减压后高于减压前[(5.25±0.78),(4.42±0.42)μV,P<0.05]。术后2d减压组减压后低于术后7d减压组、术后14d减压组(P<0.01),术后14d减压组低于术后7d减压组(P<0.05);术后7d减压组、术后14d减压组、术后不减压组低于正常对照组(P<0.01)。结论:神经元继发性损伤是视功能进行性下降的重要原因,视神经减压术有利于减轻视神经间接损伤,较早期(损伤后48h以内)减压可阻止轴突继发性损伤,避免视功能进一步下降,并在一定程度上逆转视功能的损害。     

Radioembolization with Infusion of Yttrium-90 Microspheres into a Right Inferior Phrenic Artery with Hepatic Tumor Supply Is Feasible and Safe

PurposeTo evaluate the feasibility and safety of yttrium-90 (⁹⁰Y) radioembolization through the inferior phrenic arteries (IPAs).Materials and MethodsRetrospective analysis of 108 patients referred for radioembolization to treat primary (n = 103) or secondary (n = 5) liver malignancy was performed. Five patients had malignant hepatic tumors supplied by the IPA and met criteria for infusion of ⁹⁰Y spheres into the IPA. Digital subtraction angiography (DSA), catheter-directed computed tomographic (CT) angiography, and technetium-99m (^99mTc) macroaggregated albumin (MAA) single photon emission CT (SPECT)/CT were used to plan treatment. Bremsstrahlung SPECT/CT was performed 1 day after radioembolization. Follow-up included clinical and biochemical tests and cross-sectional CT or magnetic resonance imaging.ResultsParasitized extrahepatic arteries were detected in 37% of patients (n = 40). Of these, 62.5% (n = 25) had tumor supply through an IPA. Of the patients with IPA supply, 20% (n = 5) underwent infusion of ⁹⁰Y into the right IPA. Reasons for disqualifying patients from infusion into the IPA were less than 10% tumor supply (n = 11), failed catheterization of IPA (n = 3), arterioportovenous shunt (n = 2), failed identification of IPA on pretreatment angiography (n = 1), and gastric or esophageal enhancement on catheter-directed CT angiography (n = 3). In all five patients, technical success was demonstrated on ⁹⁰Y imaging, with no significant extrahepatic radionuclide activity. No adverse events related to IPA radioembolization occurred at mean follow-up of 4.5 months (range, 2.2–10.1 mo).ConclusionsDelivery of ⁹⁰Y microspheres through the right IPA is feasible and safe with the use of catheter-directed CT angiography in addition to DSA and ^99mTc MAA SPECT/CT in patients with tumors with greater than 10% IPA supply.