犬缺血再灌注心肌靶向超声造影图像的组织定征量化研究

目的用超声组织定征量化分析白细胞靶向超声造影剂对犬心肌缺血再灌注(ischemia-reperfusion,I-R)损伤声像图。方法将自制超声微泡造影剂"表活显"(self-madesurfactantfluorocarbon-filledmicrobubbles,SFCMB)与磷脂酰丝氨酸(phosphatidylserine,PS)结合,制备成白细胞靶向超声微泡造影剂(SFCMB-PS),在实时心脏超声造影条件下,用SFCMB-PS对9只犬心肌I-R模型进行延迟心肌显像。实验结束后,在心肌I-R损伤处取组织块立即进行髓过氧化物酶(myeloperoxidase,MPO)活性测定。超声组织定征定量分析缺血再灌注损伤心肌。结果I-R损伤心肌声像图的回声强度[(22.56±4.62)GS]明显增高,与正常心肌[(16.57±3.82)GS]和缺血心肌[(5.00±2.58)GS]比较,差异均有统计学意义(P<0.01),而且其与MPO活性有良好的相关关系(r=0.776,P<0.05)。结论超声组织定征定量分析缺血再灌注心肌靶向超声显像能够较准确、客观地反映再灌注损伤的严重程度。     

超声造影剂对犬缺血再灌注心肌的靶向显像及其机制研究

目的用自制的靶向超声造影剂实现无创性地评价犬心肌缺血再灌注,同时研究其靶向性作用机制。方法将自行研制的表面活性剂超声造影剂“表活显”(surfactantfluorocarbon-filledmicrobubbles,SFCMB)与磷脂酰丝氨酸(phosphatidylserine,PS)结合,制备成靶向超声造影剂(SFCMB-PS),在实时心肌超声造影(MCE)条件下,用SFCMB-PS对犬心肌缺血再灌注模型进行延迟心肌显像。流式细胞术测定白细胞激活前和激活后与SFCMB-PS的结合情况以及在补体和β2整合素中的Mac-1缺乏时激活的白细胞与SFCMB-PS的结合情况。结果延迟心肌显像表明缺血再灌注区的造影剂回声较正常区的回声明显增强。流式细胞术证明了PS结合在造影剂微泡的表面,未激活的白细胞与微泡的结合率为(5.27±0.75)%,激活的白细胞与微泡的结合率为(39.67±6.83)%,结合率明显提高(P<0.01);补体和β2整合素中的Mac-1缺乏时,两者的结合明显受到抑制,结合率降到(12.27±1.66)%(P<0.01)和(10.90±2.40)%(P<0.01)。结论SFCMB-PS可以无创性地评价缺血再灌注损伤心肌的部位及其严重程度。SFCMB-PS是通过β2整合素中的Mac-1和补体介导途径与激活的白细胞结合并进入细胞内的。     

靶向超声微泡造影剂对犬缺血再灌注心肌的延迟显像研究

目的用自制的靶向超声微泡造影剂,实现无创性地评价犬心肌缺血再灌注(I-R)的范围及严重程度.方法将本研究所自行研制的表面活性剂类超声造影剂--"表活显"表面,结合上磷脂酰丝氨酸(PS),制备成具有靶向性的造影剂(MB-PS),用MB-PS对犬I-R模型在实时心脏超声造影条件下进行延迟心肌显像,实验结束后,心肌经0.5%伊文思蓝(Evens)和1%氯化三苯四氮唑(TTC)染色,确定缺血及坏死心肌范围,并与延迟心脏超声造影显像结果比较其一致性.结果细胞流式术(FC)证明了PS结合在造影剂微泡的表面,延迟心肌显像表明缺血再灌注区的造影剂回声较正常区的回声明显增强,与病理染色结果基本一致.结论缺血损伤再灌注后,心肌缺血部位的造影剂回声较其余部位正常心肌的造影剂回声明显增强,正是因为 MB-PS聚集并停留在缺血-再灌注区,才使得超声可以发现微泡的回声,从而得以无创性地评价炎症发生的部位及其严重程度.     

能量多普勒显像定量评价兔肾炎症组织靶向造影实验研究

目的用能量多普勒显像（PDI）定量评价免缺血再灌注损伤肾靶向造影效果。 方法将自制活性白细胞靶向造影剂和普通造影剂对兔缺血再灌注损伤肾行超声造影，采集造影前及造影后15min PDI图，用国产DFY型超声图像定量分析诊断仪对肾彩色与总面积比（CP／TP值）及彩色强度（CI值）进行定量分析，并与肾组织髓过氧化物酶活性作相关性分析。 结果造影后15min，靶向组CP／TP值及CI值显著大于普通组（P均＜0．001），且与反映肾组织炎症程度的髓过氧化物酶活性有良好相关性（P＜0．05，r=0．842和r=0．823）。 结论PDI可定量评价免缺血再灌注损伤肾靶向造影的增强效果。     

携抗P-selectin靶向超声造影剂犬体内超声分子成像

目的 制备携抗P-selectin靶向超声造影剂,探讨其评价心肌缺血再灌注损伤的超声分子成像效果。方法 采用“生物素-亲和素”桥接法制备携抗P-selectin靶向超声造影剂,建立犬心肌缺血再灌注模型,分别注入携抗P-selectin靶向超声造影剂（MBp）和空白超声造影剂（MBc）,行心肌声学造影检查,采图、存盘。应用DFY型超声图像定量分析诊断仪中的彩色编码技术对存储的图像进行脱机处理,观察MBp体内超声分子成像效果。结果 成功制备携抗P-selectin靶向超声造影剂及建立犬心肌缺血再灌注模型。彩色编码图像示MBp行心肌声学造影可见缺血再灌注区心肌显著增强;MBc于缺血再灌注区心肌造影无明显增强。结论 应用携抗P-selectin靶向超声造影剂行心肌声学造影检查能准确检测再灌注治疗后犬心肌缺血再灌注损伤。     

超声靶向微泡破坏技术评价心肌缺血再灌注损伤的研究进展

心肌缺血再灌注损伤是指原缺血心肌恢复血供后发生更为严重的损伤,再灌注损伤减弱了再灌注给机体带来的益处。心肌缺血再灌注损伤在靶向超声分子显像技术中有多种研究,包括超声靶向破坏微泡技术对心肌缺血再灌注的评价与介导靶向治疗,其中携IL-8单克隆抗体的超声靶向微泡破坏技术可明显减轻再灌注后炎症反应引起的损伤,减轻心肌坏死程度。     

利用白细胞靶向超声造影无创检测心肌缺血再灌注损伤

心肌缺血再灌注发生后 ,白细胞可大量渗入心肌层使心肌细胞受损甚至坏死。本研究用于检测如下假说 :利用白细胞靶向声学造影剂进行心脏超声造影检查 ,可以对心肌缺血再灌注后心肌炎的发生范围及其程度进行良好评价。方法 :将磷脂酰丝氨酸 (ｐｈｏｓｐｈａｔｉｄｙｌｓｅｒｉｎｅ ,ＰＳ)结合于脂质微泡外壳制成可与白细胞靶向结合的新型造影剂 (ＭＢ -ＰＳ)。将9只 3 0～ 3 5ｋｇ的实验犬开胸 ,先静脉注射Ｏｐｔｉｓｏｎ行心脏超声造影检查评估各动物心肌血流灌注情况 ,再将其中 6只犬的冠状动脉左前降支或左旋支钳夹 90ｍｉｎ ,钳夹期间 ,再…     

瑞芬太尼后处理对大鼠心肌缺血再灌注细胞凋亡的影响

目的：观察瑞芬太尼后处理对大鼠心肌缺血再灌注细胞凋亡的影响。方法建立60只大鼠心肌缺血再灌注损伤模型。随机分为假手术组（ sham组）、缺血再灌注对照组（ I-R组）和瑞芬太尼不同剂量后处理组（RPO1、RPO2、RPO3组）,RPO1、RPO2、RPO3组再灌注之初分别以2、4、6μg／kg静脉泵注5 min,停止5 min,重复进行三次。实验结束后留取左室心肌组织标本,光镜下观察心肌组织的病理变化;用原位末端转移酶标记法（ TUNEL）检测各组心肌细胞的凋亡指数（AI）;用蛋白免疫印迹（Western blot）法检测各组心肌细胞色素C（CytC）含量。结果①光镜观察：RPO组大鼠的心肌组织损伤程度明显低于I-R组。②RPO组心肌细胞AI明显低于I-R组（P＜0．05）,各RPO组之间心肌组织AI呈剂量依赖性（P＜0．05）。③RPO组心肌细胞胞浆中的CytC含量明显低于I-R组（ P＜0．05）。结论①瑞芬太尼后处理可以减轻大鼠心肌缺血再灌注损伤。②瑞芬太尼三种不同浓度后处理对减轻心肌组织损伤有明显的差别。③瑞芬太尼后处理减轻大鼠心肌缺血再灌注损伤的机制可能与抑制细胞凋亡有关。     

超声组织定征视频法监控兔缺血再灌注肾靶向声学造影实验研究

目的定量评价自制靶向超声造影剂对兔缺血再灌注肾显像的靶向增强效果。方法将磷脂酰丝氨酸(phos-phatidylserine,PS)加在自制表面活性剂类超声造影剂微泡壁上,用有和无PS造影剂分别对6只肾缺血再灌注损伤兔进行声学造影,谐波显像观察肾实质回声的变化,用国产“DFY-2型超声图像定量分析诊断仪”对兔肾实质灰阶(GS)值进行动态定量分析。结果造影后,有和无PS组GS峰值分别高于造影前(P<0.001和P<0.05);有PS组GS峰值高于无PS组(P<0.001)。结论超声组织定征视频法可定量评价兔缺血再灌注肾靶向声学造影的增强效果。     

二次谐波显像估价正常心肌血流灌注

本文的目的是比较静脉注射声学造影剂后基波显像和二次谐波显像估价正常心肌血流灌注的能力。在10条开胸犬，静脉注射氟碳微泡造影剂（0．01ml／公斤体重）。使用二次谐波样机（HP）获得乳头肌水平左室短轴，探头频率为1．8／3．6MHz。将41×41像素的取样区置于左空腔和左室前壁心肌，用声学密度法进行定量分析。视觉造影效果以0，1＋，2＋和3＋的分级方法进行定性分析。使用二次谐波时，18次静脉注射产生了明显的心肌显影（3级），且心肌显影的时间明显延长。而基波显像则14次出现了中等度的心肌显影（2级）。二次谐波产生的心肌声学密度较基波明显为高（9．8±1.4声学单位，6．5±1．1声学单位），两组之间有明显的统计学差别（P＜0．001）。但左室腔的声学密度仅比心肌高一倍。二次谐波结合较低剂量的造影剂所引起的声影持续时间较短。静脉注射声学造影剂未引起血流动力学改变。结论：二次谐波显像技术结合新型声学造影剂可以非损伤性估价心肌血流灌注，这种方法明显优于目前临床使用的常规显像方法。     

被动靶向心肌超声造影评价大鼠心脏移植术后急性排斥反应

目的探讨白细胞被动靶向心肌超声造影对心脏移植术后急性排斥反应的诊断价值。方法成功建立20只大鼠腹部异位心脏移植模型,其中同种异体移植12例(实验组),同系移植8例(对照组)。术后第3天,将声诺维(SonoVue)经静脉持续注入大鼠体内,应用心肌超声造影技术观察异位移植心脏,分别取得注入造影剂20 s时的心肌灌注图像和5 min时的白细胞被动靶向心肌造影图像,利用图像分析仪分别测定其造影图像灰阶值(GS_(20s)、GS_(5m)),靶向灰阶值(GS_(target))为同一只大鼠的GS_(5m)与GS_(20s)之差。观察完毕后处死大鼠行病理检查,HE染色确定移植心肌排斥程度,免疫组织化学检测移植心组织内CD3~+T细胞浸润程度,将随机10个高倍视野下的CD3~+T细胞数量定为CD3~+细胞记数,并将其分别与GS_(20s)、GS_(5m)、GS_(target)做相关分析。结果心肌灌注成像显示实验组GS_(20s)稍低于对照组GS_(20s)(P0.05),但差异无统计学意义。白细胞被动靶向心肌造影显示实验组GS_(5m)明显高于对照组GS_(5m)(P0.001),且GS_(target)实验组显著高于对照组(P0.001)。HE染色移植心肌显示对照组多为正常心肌组织,而实验组心肌多为Ⅲ～Ⅳ级排斥反应,免疫组织化学检测显示CD3~+细胞记数实验组较对照组显著增高(P0.001),相关分析显示:CD3~+细胞记数与GS_(target)呈明显正相关(r=0.79,P0.001)。结论白细胞被动靶向心肌超声造影技术能无创、有效地评价心脏移植术后的急性排斥反应。     

携Sialyl Lewis^X超声微泡靶向探查缺血心肌的炎症分子“印记”

目的探讨应用靶向超声分子成像探查心肌缺血再灌注损伤炎症“印记”的可行性。方法采用“亲和素-生物素”桥接法构建携唾液酸化路易斯（Sibyl Lewis^X）靶向超声微泡（MBsLex）和同型对照微泡（MBc）。10只心肌缺血再灌注小鼠随机先后注入MBsLex和MBc（间隔30min）,分别于注入5min后行心肌对比超声检查,测量心肌缺血区和非缺血区的声强度（Ⅵ）。结果对比超声图像显示MBsLex组缺血区心肌造影见显著增强,Ⅵ值高达23．52±1．08,而在MBc组缺血区心肌造影仅见轻度增强,Ⅵ缸为9．81±0．41,两者之间差异有统计学意义（P〈0．05）。但无论MBsLex组还是MBc组,缺血区心肌Ⅵ值均明显高于非缺血区心肌Ⅵ值（P〈0．05）。两组非缺血区心肌之间Ⅵ值未见明显差异。结论应用携sLex超声微泡行对比超声能够靶向探查心肌缺血再灌注损伤的炎症“印记”。     

Real-time myocardial blood flow imaging in normal human beings with the use of myocardial contrast echocardiography.

Triggered myocardial contrast echocardiography (MCE) has been used successfully to quantify myocardial blood flow and assess coronary stenosis in animal models, but practical considerations have limited its broad clinical use. Real-time MCE may have practical advantages to assess perfusion and real time myocardial blood flow in human beings. We compared real-time MCE with triggered imaging in 23 normal human volunteers by using an investigational ultrasound contrast agent (DMP-115) and a commercially available ultrasound platform (Acuson Sequoia). Peak myocardial opacification (reflecting myocardial blood volume) after contrast infusion was quantified digitally in gray scale units (GU). In 13 subjects, myocardial blood flow reserve was assessed during dipyridamole infusion with the use of intermittent destruction-replenishment techniques. Real-time MCE resulted in a 30- to 45-GU increase from baseline compared with a 20- to 70-GU increase with triggered imaging. Real-time MCE showed no statistical difference in opacification (P = .131 by analysis of variance) among any of the myocardial regions of interest. Triggered imaging resulted in heterogeneous opacification among the regions of interest (P < .05 by analysis of variance). Dipyridamole did not significantly change peak myocardial opacification (myocardial blood volume) for either technique. Quantification of flow reserve revealed that myocardial blood flow reserve for the dipyridamole group was 3.6 +/- 0.4 (mean +/- 1 standard error of the mean). Real-time MCE is feasible in normal human volunteers and provides homogenous opacification of the myocardium. Furthermore, quantification of myocardial blood flow with real-time MCE in normal human beings produces results that are consistent with the known physiology of the coronary microcirculation.     

选择性心肌超声造影对冠状动脉介入治疗后即刻心肌灌注变化的初步研究

目的 采用选择性心肌超声造影（MCE）探讨冠状动脉介入（PCI）术后冠状动脉微循环改善情况。方法 对14例冠心病患者分别于PCI术前及冠状动脉开通后即刻经冠状动脉注射造影剂，在对比脉冲序列成像（CPS）条件下行MCE检查，对比观察心肌显影效果，并采用CUSQ软件进行脱机分析，计算心肌节段微血管灌注的平均灌注量（minivalue）。结果 冠状动脉内注入造影剂即刻能够获得清晰心肌显影，所有患者均获得较满意的左心室及心肌显影。14例患者中12例冠状动脉开通，2例冠状动脉慢性闭塞未能开通。13例于PCI术前MCE显示狭窄或闭塞冠状动脉的对应心肌节段显示节段性充盈减低或无造影剂充盈，1例慢性冠状动脉闭塞性病变患者冠状动脉造影显示侧支循环良好，MCE显示闭塞冠状动脉对应心肌节段充盈基本接近正常。冠状动脉成功开通的12例患者术后即刻MCE显示11例术前闭塞冠状动脉对应心肌节段充盈较术前改善，心肌节段微血管灌注的平均灌注量较术前增加（P〈0．05），1例改善不明显。结论 PCI能够有效改善病变心肌微循环，选择性MCE在CPS条件下能够准确、快速、有效地评价PCI后心肌再灌注情况。     

Noninvasive vessel-selective perfusion imaging with intravenous myocardial contrast echocardiography.

BACKGROUND: Intravenous myocardial contrast echocardiography (MCE) cannot identify each perfusion area of coronary vessels separately. However, by destroying microbubbles passing through a specific vessel using high-power ultrasound during intravenous MCE, vessel-selective perfusion imaging (VSPI) may be feasible. METHODS: In 10 open-chest dogs, intermittent short-axis images were obtained during contrast agent infusion using an ultrasound system. For VSPI, a probe coupled to another ultrasound machine was placed on the proximal left circumflex coronary artery (LCx). High-power ultrasound pulses were transmitted to destroy bubbles passing through the LCx. A negative contrast area on VSPI was considered to represent the perfusion area of the LCx (LCx-VSPI). A negative contrast area on conventional MCE during LCx occlusion and a region without staining by Evans blue dye were used as gold standards for defining the LCx perfusion area. LCx-VSPI was compared with a negative contrast area on conventional MCE during LCx occlusion and a region without staining by Evans blue dye. RESULTS: Despite lack of LCx occlusion, high-power destructive pulses produced a definite area of negative contrast on the LCx region. Decreased power of ultrasound pulses resulted in disappearance of the negative contrast area. An excellent relationship was demonstrated between both LCx-VSPI and a negative contrast area on conventional MCE during LCx occlusion (r = 0.93, P <.0001), and LCx-VSPI and a region without staining by Evans blue dye (r = 0.92, P =.0002). CONCLUSION: VSPI during intravenous MCE may be feasible for noninvasive assessment of perfusion areas associated with specific vessels.     

Impact of myocardial contrast echocardiography on vascular permeability: an in vivo dose response study of delivery mode, pressure amplitude and contrast dose

An in vivo rat model of myocardial contrast echocardiography (MCE) was defined and used to examine the dose range response of microvascular permeabilization and premature ventricular contractions (PVCs) with respect to method of imaging, peak rarefactional pressure amplitude (PRPA) and agent dose. A left ventricular short axis view was obtained on anesthetized rats at 1.7 MHz using a diagnostic ultrasound system with simultaneous ECG recording. Evans blue dye, a marker for microvascular leakage, and a bolus of Optison were injected i.v. Counts of PVCs were made from video tape during the 3 min of MCE. Hearts were excised 5 min after imaging and petechial hemorrhages, Evans blue colored area and Evans blue content were determined. No PVCs or microvascular leakage were seen in rats imaged without contrast agent followed by contrast agent injection without imaging. When PVCs were detected during MCE, petechial hemorrhages and Evans blue leakage were also found in the myocardium. Triggering 1:4 at end-systole produced the most PVCs per frame and most microvascular leakage, followed by end-systole 1:1, continuous scanning and end-diastole triggering 1:1. All effects increased with increasing Optison dosage in the range 25 to 500 microL kg(-1). Ultrasound PRPA was important, with apparent thresholds for PVCs at 1.0 MPa and for petechiae at 0.54 MPa. PVCs, petechial hemorrhages and microvascular leakage in the myocardium occur as a result of MCE in rats.     

二次谐波触发显像声学造影评价急性心肌缺血的实验研究

目的　采用二次谐波触发显像超声造影评价急性缺血心肌血流灌注。方法　对 10只犬急性心肌缺血模型用自制的白蛋白氟碳气体声学造影剂进行心肌声学造影 ,测量心肌灌注缺损面积 ,与心肌病理染色对照。结果　造影后正常心肌回声显著增强。缺血心肌呈现灌注缺损。缺损面积与心肌病理染色测值相关良好。结论　自制的声学造影剂安全有效 ,能用于动物心肌缺血的实验研究。