超声介导微泡造影剂对大鼠心肌组织的毛细血管和细胞影响的研究

目的探讨超声介导微泡造影剂（MBCA）对大鼠心肌组织的毛细血管和细胞的影响。方法大鼠经股静脉输入含氟碳气体的微泡造影剂,应用超声辐照其心肌组织,超声辐照后取左心室前壁心肌,用透射电镜观察其毛细血管和细胞。结果用透射电镜观察：超声介导MBCA这一技术会使大鼠心肌组织毛细血管壁破裂,红细胞外溢到心肌纤维间,心肌纤维断裂、溶解。结论超声介导微泡造影剂能引起心肌组织的毛细血管,心肌细胞发生变化。     

超声微泡造影剂对心肌组织的生物学效应及介导VEGF基因转染大鼠心肌的实验研究

目的 探讨超声微泡造影剂对心肌组织的生物学效应及其介导VEGF基因转染大鼠心肌的有效性。方法 18只健康雄性Wistar大鼠，取3只采用超声波在鼠胸壁破坏微泡造影剂，观察对心肌组织显微结构的影响。将另15只急性心肌梗死3天后的雄性Wistar大鼠分为3组，每组5只。第一组采用超声破坏微泡造影剂的方式，将pcDzVEGFm基因转染大鼠心肌至造影剂不再显影(约6min)；第二组尾静脉输入同等剂量携pcD。VEGF。基因的造影剂；第三组为对照。2周后，取缺血心肌组织行VEGF免疫组织化学染色，观察心肌组织血管内皮生长因子(VEGF)蛋白表达情况。结果超声波破坏微泡造影剂能使心肌组织充血，产生大量空泡，并有部分心肌细胞坏死。采用超声微泡造影剂介导的VEGF基因转染，能明显增强大鼠心肌组织VEGF蛋白的表达。结论 超声微泡造影剂能明显增强对组织的空化效应，其介导的VEGF基因治疗是一种无创、新型、高效的基因转移方法。     

超声波与微泡声学造影剂增强基因定位转染动物实验研究

目的观察经静脉注射基因与微泡声学造影剂,同时经皮超声辐照肝脏方式能否增强小鼠肝脏基因定位转染及其转染效率.方法昆明种小白鼠24只,随机分为4组,每组6只.第1组为单纯质粒转染组:经尾静脉快速注入2 ml含20 μg乙型肝炎核心抗原(pcDNA3.1/HBV)质粒的生理盐水溶液.第2组为单纯微泡转染组:经尾静脉快速注入2 ml含20 μg质粒的微泡声学造影剂.第3组为单纯超声转染组:经尾静脉快速注入2 ml含20 μg质粒的生理盐水溶液,同时采用频率为1 MHz、声强为0.5 W/cm2的超声波经小白鼠体表肝区辐照1 min.第4组为超声与微泡转染组:经尾静脉快速注入2 ml含20 μg质粒的微泡声学造影剂,同时经小白鼠体表肝区局部采用相同剂量超声辐照1 min.7天后处死小鼠,分别取肝、肾、肺、心、脾、骨骼肌组织进行pcDNA3.1/HBV免疫组化检测,记录不同组织每高倍视野(×400)pcDNA3.1/HBV表达阳性细胞数.结果第1、2组肝、肾组织内偶见pcDNA3.1/HBV表达弱阳性细胞,肺、心、脾、骨骼肌组织未见表达阳性细胞.第3组肝组织内可见少量pcDNA3.1/HBV阳性细胞,每高倍视野表达阳性细胞(26.5±3.9)个.肾、肺、心、脾、骨骼肌组织未见表达.第4组肝组织内pcDNA3.1/HBV表达最强,每高倍视野表达阳性细胞(84.2±4.4)个,为第3组的约3.2倍.肾、肺、心、脾、骨骼肌组织未见表达.结论静脉注射黏附质粒的微泡声学造影剂同时经体表给予一定强度的超声辐照,能显著增强辐照部位局部组织的基因转染与表达,有望成为一种安全、高效的体内基因定位转染新技术.     

超声波与微泡声学造影剂增强体外培养肿瘤细胞基因转染实验研究

目的观察超声波与微泡声学造影剂能否增强体外培养肿瘤细胞基因转染及其转染效率,初步摸索适宜的超声辐照条件.方法将培养的HepG2细胞分为3组,第1组为单纯造影剂转染组:加入5 μg绿色荧光蛋白质粒(PEGFP-C1)与微泡声学造影剂混合液进行转染;第2组为脂质体转染组:用相同浓度PEGFP-C1质粒进行常规脂质体转染;第3组为造影剂加超声辐照转染组:加入5 μg PEGFP-C1质粒与微泡声学造影剂混合液,然后分别用0.25 W/cm2、0.5 W/cm2、1.0 W/cm2超声波经培养板底部辐照10 s.24 h后用荧光显微镜观察各转染组细胞荧光蛋白表达情况,计录每高倍视野(400×)荧光蛋白表达阳性细胞数.结果单纯造影剂转染组未见荧光蛋白表达阳性细胞,造影剂加超声辐照转染组可见不同程度荧光蛋白表达,其中以0.5 W/cm2超声辐照组表达最强,每高倍视野绿色荧光蛋白表达阳性细胞数为(20.7±3.2)个/HP,高于0.25 W/cm2与1.0 W/cm2超声辐照组[分别为(4.8±1.9)个/HP;(9.9±2.3)个/HP],与脂质体转染组[(22.1±3.5)个/HP]比较无显著差异(P>0.05).结论微泡声学造影剂加一定强度的超声辐照能显著增强体外培养肿瘤细胞的基因转染与表达,超声辐照条件是影响转染率的重要因素,适宜条件时其转染效率与常规脂质体转染方法无显著差异.     

微泡造影剂联合超声辐照介导的绿色荧光蛋白质粒转染小鼠肝癌的实验研究

目的探讨微泡造影剂SonoVue联合超声辐照在介导体内基因转染中的作用。方法建立小鼠肝癌皮下移植瘤模型，尾静脉注入绿色荧光蛋白质粒（pEGFP），添加或不添加SonoVue，脉冲多普勒超声辐照（1MHz，2W／cm^2）瘤组织。持续时间1、5、10min，7d后流式细胞仪、荧光显微镜评价pEGFP转染率。HE染色行肿瘤病理学检查。结果SonoVue联合超声辐照组pEGFP的转染率显著高于单纯超声辐照组（P〈0．01）；仅SonoVue与单纯pEGFP2组间转染率无显著差异（P〉0．05）；辐照时间5、10min时pEGFP表达明显高于1min（P〈0．05）。5与10min组间pEGFP表达无显著差异（P〉0．05）。HE染色肿瘤组织无坏死灶出现。结论微泡造影剂联合超声辐照可明显提高基因转染率，且对组织无损害。     

评价超声联合白蛋白微泡造影剂实现基因转染靶向性的研究

目的 评价超声联合白蛋白微泡造影剂实现基因转染的靶向性.方法 选择增强型绿色荧光蛋白质粒为报告基因,经股静脉输入黏附质粒的白蛋白微泡的同时在大鼠背部脊斜肌区域经皮辅予一定强度的超声照射对大鼠脊斜肌行基因转染,转染7 d后,取脊斜肌、肝、肾、心肌组织快速冷冻切片,荧光显微镜下观察各组织内的荧光表达.结果 脊斜肌组织中可见较多特异性绿色荧光,多位于微血管周围,荧光强度较其余组织明显增强(P<0.05),肝脏、肾脏组织中见少量特异性绿色荧光,肝脏荧光强度约为肾脏的4倍(P<0.05),心肌组织中未见特异性绿色荧光.结论 静脉注射黏附质粒的微泡声学造影剂同时经体表给予一定强度的超声辐照,可以较好地实现基因的靶向转染.     

亚微米级超声微泡造影剂的制备及体外基因转染效率的实验研究

目的 探索制备亚微米级超声微泡造影剂的方法 ,以GFP作为目的 基因验证其作为一种新型基因载体的可行性.方法 以高剪切分散法制备超声微泡造影剂,透射电镜及激光粒度分析仪检测其形态及粒径;将超声微泡造影剂与不同剂量的绿色荧光蛋白质粒PShuttle-IRES-hrGFP-1结合后转染HepG2细胞,利用荧光显微镜观察并检测其基因转染效率.结果 自制超声微泡造影剂为均匀分散的圆泡,粒径分布在282.2～415.7 nm之间,平均值为(335±5)nm,达到亚微米级;该微泡能将GFP基因成功转运到HepG2细胞内并高效表达,转染效率达32.61%±3.42%.结论 自制亚微米级超声微泡造影剂粒径小、分散均匀,并能成功转运外源DNA进入细胞内,可作为一种新型基因载体.     

超声辐照微泡对大鼠前列腺增生组织通透性的影响

目的探讨大鼠前列腺增生组织通透性的改变及超声微泡对通透性的影响。方法24只SD大鼠随机分为正常组、前列腺增生组、超声辐照微泡治疗前列腺列增生组(UM BPH组)。UM BPH组注射白蛋白微泡并对前列腺局部用UGT1025型超声基因转染仪辐照。各组电镜观察其前列腺血管及细胞膜变化、计算前列腺指数(prostaticindex,PI),并测定前列腺组织中台盼蓝含量。结果电镜观察可见UM BPH组微血管基底膜变薄,部分血管周围有红细胞漏出,前列腺上皮细胞结构疏松,线粒体内可见空化;BPH组前列腺指数为2.88±0.03,UM BPH组为2.88±0.02,较正常组1.57±0.04均明显增加(P<0.05);前列腺组织中台盼蓝的含量:UM BPH组为(8.54±0.23)×10-9g/L,较BPH组[(2.54±0.11)×10-9g/L]及NP组[(4.20±0.22)×10-9g/L]明显增加(P<0.05)。结论在大鼠BPH时,组织通透性有所下降,超声辐照白蛋白微泡可以增加前列腺组织的通透性。     

超声联合微泡造影剂促进干细胞移植研究进展

干细胞移植已应用于多种疾病的治疗研究,但其效果受到移植干细胞存活率、分化率以及靶向性等因素影响.随着超声影像学技术的不断发展,超声联合微泡造影剂不仅能有效介导细胞基因转染,而且能靶向性传递移植细胞,从而提高干细胞移植效果.本文将就近年来超声联合微泡造影剂促进干细胞移植的研究进展作一综述.     

微泡造影剂及超声促进绿色荧光蛋白质粒在人肝癌细胞HepG2内表达的实验研究

目的研究微泡造影剂与超声辐照是否能提高绿色荧光蛋白质粒在人肝癌细胞HepG2中的转染率。方法将培养的HepG2细胞分为四组：第一组为对照组;第二组以脂质体转染;第三组加入微泡造影剂SonoVue并予以超声辐照;第四组加入脂质体和微泡造影剂SonoVue并予以超声辐照．将合有绿色荧光蛋白报告基因的真核表达质粒pEGFP-N1转染人肝癌细胞HepG2,24小时后以荧光显微镜观察人肝癌细胞HepG2中的绿色荧光蛋白表达情况,并用流式细胞仪测算转染率。结果脂质体转染组与微泡造影剂＋超声辐照组有显著性差异（P〈0．05）。脂质体＋微泡造影剂＋超声辐照组与微泡造影剂＋超声辐照组有显著性差异（P〈0．01）结论微泡造影剂和超声辐照协同脂质体能提高目标基因在肝癌细胞内的转染率。     

超声介导微气泡造影剂促反义寡核苷酸转染的有效性研究

目的探讨超声介导脂质体微气泡转染反义寡核苷酸HA-2741的有效性。方法12孔板培养人乳腺癌细胞,分组为:(1)单纯超声照射;(2)单纯造影剂;(3)单纯HA-2741;(4)超声照射 HA-2741;(5)造影剂 HA-2741;(6)造影剂 HA-2741 超声照射;(7)脂质体 HA-2741;(8)脂质体 HA-2741 超声照射。造影剂浓度2%,超声波发射频率1.3MHz,强度-3dB,照射时间30s,予与实验刺激后,流式细胞仪定量分析HA-2741的转染率,RT-PCR的检测乳腺癌细胞的HER-2mRNA水平,免疫细胞化学检测HER-2蛋白的表达。结果造影剂 HA-2741 超声照射组HA-2741的转染率显著高于其余各组,约94.6%,造影剂 HA-2741 超声照射组乳腺癌细胞的HER-2mRNA水平显著降低,HER-2蛋白表达明显减低,其程度与HA-2741转染率呈正相关。结论超声介导微气泡造影剂显著增加基因的转染效率,方法简便,安全,具有良好的靶向性。     

超声联合微泡在肿瘤化疗增敏的基础研究与临床应用进展

恶性肿瘤是一类死亡率很高的疾病,化疗是其重要的治疗方法之一。应用微泡的声孔效应提高细胞对化疗药物的摄取以增加肿瘤组织局部药物浓度达到增敏化疗的目的,是目前肿瘤治疗研究的新方向之一。超声联合微泡可增加肿瘤组织局部药物浓度、增强细胞毒作用,促进肿瘤细胞凋亡,缩小肿瘤体积,改善肿瘤对化疗药物的耐药性,具有良好的临床应用价值及前景。本文拟从超声联合微泡增敏肿瘤化疗的基础研究及临床运用方面进行综述。     

治疗超声介导微泡造影剂对体外血栓的助溶研究

目的运用本科自制脂膜氟烷超声造影剂“脂氟显”结合治疗超声对组织纤溶酶原激活物(tissue-plasminogen activator,t-PA)助溶体外血栓的有效性进行研究。方法取健康人全血制成质量约200~300mg血栓,频率1MHz治疗超声结合“脂氟显”和t-PA进行溶栓治疗。计算治疗前后的血栓质量,得到溶栓率,进行统计学分析。结果组间比较溶栓率超声+t-PA+“脂氟显”组(50.05±6.59)%与单纯超声辐照(24.14±3.93)%、单纯t-PA组(35.66±3.34)%、超声+t-PA组(41.85±4.78)%及超声+“脂氟显”组(29.51%±5.17)%间差异均有十分显著性意义(P<0.01);超声+“脂氟显”组与单纯超声辐照组间比较差异有显著性意义(P<0.05)。结论微泡超声造影剂在治疗超声介导下对t-PA助溶体外血栓有显著效果。     

Treatment of Microvascular Micro-embolization Using Microbubbles and Long-Tone-Burst Ultrasound: An in Vivo Study

Despite epicardial coronary artery reperfusion by percutaneous coronary intervention, distal micro-embolization into the coronary microcirculation limits myocardial salvage during acute myocardial infarction. Thrombolysis using ultrasound and microbubbles (sonothrombolysis) is an approach that induces microbubble oscillations to cause clot disruption and restore perfusion. We sought to determine whether this technique could restore impaired tissue perfusion caused by thrombotic microvascular obstruction. In 16 rats, an imaging transducer was placed on the biceps femoris muscle, perpendicular to a single-element 1-MHz treatment transducer. Ultrasound contrast perfusion imaging was performed at baseline and after micro-embolization. Therapeutic ultrasound (5000 cycles, pulse repetition frequency = 0.33 Hz, 1.5 MPa) was delivered to nine rats for two 10-min sessions during intra-arterial infusion of lipid-encapsulated microbubbles; seven control rats received no ultrasound–microbubble therapy. Ultrasound contrast perfusion imaging was repeated after each treatment or control period, and microvascular volume was measured as peak video intensity. There was a 90% decrease in video intensity after micro-embolization (from 8.6 ± 4.8 to 0.7 ± 0.8 dB, p < 0.01). The first and second ultrasound–microbubble sessions were respectively followed by video intensity increases of 5.8 ± 5.1 and 8.7 ± 5.7 dB (p < 0.01, compared with micro-embolization). The first and second control sessions, respectively, resulted in no significant increase in video intensity (2.4 ± 2.3 and 3.6 ± 4.9) compared with micro-embolization (0.6 ± 0.7 dB). We have developed an in vivo model that simulates the distal thrombotic microvascular obstruction that occurs after primary percutaneous coronary intervention. Long-pulse-length ultrasound with microbubbles has a therapeutic effect on microvascular perfusion and may be a valuable adjunct to reperfusion therapy for acute myocardial infarction.     

Spatial Distribution of Ultrasound Targeted Microbubble Destruction Increases Cardiac Transgene Expression But Not Capillary Permeability

Ultrasound targeted microbubble destruction (UTMD) has evolved as a promising tool for organ specific gene and drug delivery. Using DNA-loaded microbubbles, cardiac transfection has been shown to be feasible. However, two-dimensional properties of the ultrasound beam limit cardiac transgene expression to the focal zone, thus, reducing its potential therapeutic effect. The aim of this study was to test if spatial distribution of ultrasound targeted microbubble destruction in the heart could lead to augmented transgene expression or increased capillary permeability. Lipid microbubbles containing plasmids with a luciferase transgene were used to target rat hearts. The diagnostic ultrasound probe was fixed in a mid-short axis view with a gel stand-off between the chest and probe. Ultrasound (1.3 MHz) with a mechanical index of 1.6 was intermittently applied to rats during microbubble infusion. Rats were randomized to either stay in that position or move horizontally in a cranio-caudal direction (3 mm sweep) relative to the ultrasound probe during UTMD. After 4 days, organs were harvested and analyzed for reporter gene expression. Another group of rats received Evans Blue, followed by UTMD with unloaded microbubbles. Again, rats were randomized into a static or moving group. Hearts were harvested to evaluate extravasation of Evans Blue. Moving rats in a cranio-caudal direction significantly increased transgene expression by 19-fold in the anterior heart, by sixfold in the posterior heart and by 32-fold in the apex. Interestingly, Evans Blue extravasation was not augmented in the moving group. Spatial distribution of UTMD may increase transgene expression due to sonication of larger areas in the heart. In contrast, capillary permeability does not increase, indicating less capillary damage. (E-mail: raffi.bekeredjian@med.uni-heidelberg.de)     

Ultrasound-Mediated Microbubble Destruction Increases Renal Interstitial Capillary Permeability in Early Diabetic Nephropathy Rats

Diabetic nephropathy (DN) is defined as persistent proteinuria corresponding to a urinary albumin excretion rate >300 μg/mg in the absence of other non-diabetic renal diseases. The aim of this study was to determine if ultrasound (US)-mediated microbubble (MB) destruction could increase renal interstitial capillary permeability in early DN rats. Diabetes was induced with streptozotocin. DN rats presented with mild micro-albuminuria 30 d after onset of diabetes. DN rats (N = 120) were divided into four groups that received Evans blue (EB) followed by: (i) no treatment (control group); (ii) continuous ultrasonic irradiation for 5 min (frequency = 7.00 MHz, mechanical index = 0.9, peak rarefactional pressure = 2.38 MPa: US group); (iii) microbubble injection (0.05 mL/kg: MB group); and (iv) both ultrasound and microbubble injection (US + MB group). Another 8 DN rats were subjected to ultrasound and microbubbles and then injected with EB after 24 h (recovery group). EB content, EB extravasation and E-selectin mRNA and protein expression significantly increased, and interstitial capillary walls became discontinuous in the US + MB group. Neither hemorrhage nor necrosis was observed on renal histology. Urine samples were collected 24 h post-treatment. There was no hematuria, and the urinary albumin excretion rate did not increase after ultrasound-microbubble interaction detected by urinalysis. EB content returned to the control group level after 24 h, as assessed for the recovery group. In conclusion, ultrasound-mediated microbubble destruction locally increased renal interstitial capillary permeability in DN rats, and should be considered a therapy for enhancing drug and gene delivery to the kidney in the future.     

诊断超声联合微泡对兔VX2肿瘤的血流增强效应

目的探讨不同机械指数(MI)的诊断超声联合微泡对兔VX_2肿瘤的血流增强效应。方法选取健康雄性新西兰白兔40只,采用单侧大腿内侧瘤组织块接种法接种VX_2肿瘤,造模成功后将其随机分为实验1组(MI=0.3)、实验2组(MI=0.7)、实验3组(MI=1.4)及对照组,每组各10只。抽取0.2 ml"脂氟显"用5.0 ml生理盐水稀释后经耳缘静脉通道匀速推入,同时分别经不同机械指数辐照肿瘤,对照组予以超声假照,时间均为5 min。储存治疗前后动态造影图像,并用造影分析软件分析,记录峰值强度(PI)和曲线下面积(AUC)。结果实验1组、实验3组治疗前后PI比较差异均有统计学意义(P=0.028、0.018),实验2组、对照组治疗前后PI比较差异无统计学意义(P=0.994、0.978);实验3组治疗前后AUC值比较差异有统计学意义(P=0.009),实验1、2组及对照组治疗前后AUC值比较差异均无统计学意义(P=0.099、0.497、0.898)。结论低能量诊断超声(MI=0.3)联合微泡可丰富兔VX_2肿瘤血供,高能量诊断超声(MI=1.4)可减少血流灌注。     

Effects of Focused Ultrasound and Microbubbles on the Vascular Permeability of Nanoparticles Delivered into Mouse Tumors

Ultrasound sonication with microbubbles (MBs) was evaluated for enhancement of the release of nanoparticles from vasculature to tumor tissues. In this study, tumor-bearing Balb/c mice were insonicated with focused ultrasound (FUS) in the tumors after the injection of MBs (SonoVue^®) and then lipid-coated quantum dot (LQD) nanoparticles (130 ± 25 nm) were injected through the tail vein. We studied the effects of the injected MB dose (0–300 μL/kg), sonication duration (0–300 s) and treatment-procedure sequence on the accumulation of nanoparticles in the tumors 24 h after the treatment and the time response of the accumulation (0.5–24 h). After the treatment, the mice were sacrificed and perfused and then the tumor tissues were harvested for quantifying the amount of nanoparticles using graphite furnace atomic absorption spectrometry (GF-AAS). The results showed that pulsed-FUS sonication with MBs can effectively enhance the vascular permeability for LQD nanoparticle delivery into the sonicated tumors. It indicates that this technique is promising for a better nanodrug delivery for tumor chemotherapy. (E-mail: winli@ntu.edu.tw)     

超声对胆管癌分期诊断探讨:对血管浸润的诊断

目的：探讨超声对胆管癌浸润血管的诊断价值,提高手术切除率。方法：回顾性分析了５２例胆管癌资料,重点观察局部肿瘤与相邻血管关系,并设定了超声对血管浸润的诊断指标。结果：手术病理证实胆管癌３７％（１９／５２）门脉受侵。超声评价胆管癌门脉受侵的敏感性、特异性及诊断正确率分别为５６％（９／１６）、８９％（３２／３６）和７９％（４１／５２）;超声分级低于病理分级者占１５％（８／５２）,高于病理分级者占６％（３／５２）;彩色超声亦有助于肝动脉分支的观察评价。结论：超声是一种较好的评价胆管癌周围血管受侵及其程度的方法,其无创伤及特异性高,有推广应用价值。     

超声辐照联合超声造影剂介导的HSV-TK/GCV体外杀伤血管内皮细胞

目的探讨采用超声辐照联合超声造影剂介导含血管内皮生长因子受体-胸腺激酶(KDR-TK)基因的真核表达质粒载体转染血管内皮细胞的有效性,以及调控单纯疱疹病毒I型的胸腺激酶(HSV-TK)在血管内皮细胞中特异性杀伤作用。方法基因重组构建真核表达质粒载体pEGFP-KDR-TK,采用超声辐照联合超声造影剂SonoVue介导方式转染血管内皮细胞,MTT检测更昔洛韦(GCV)对KDR-TK/VEC(VEC)、原代人脐因管内皮细胞(HUVEC)、人肝癌细胞株(HepG2)的杀伤作用。结果GCV浓度为1、10、50和100μg/ml时,KDR-TK/VEC和HUVEC细胞抑制率分别为14.7%±11.0%vs5.2%±3.3%,P=0.412;44.9%±24.6%vs13.2%±1.7%,P=0.010;68.8%±7.0%vs26.2%±9.3%,P=0.001和73.2%±32.8%vs38.8%±16.8%,P=0.006。而HepG2细胞抑制率仅为6.1%±5.1%,9.4%±1.9%,13.2%±0.4%和14.7%±6.9%,与前两者比较,P均<0.05。结论超声辐照联合SonVue能有效地介导含KDR-TK真核表达质粒转染血管内皮细胞,可调控HSV-TK/GCV对血管内皮细胞的特异性杀伤作用。