超声破坏微泡造影剂促进心肌梗死大鼠血管新生的实验研究

目的 探讨超声破坏微泡造影剂刺激大鼠心肌血管内皮生长因子(VEGF)分泌、促进新血管生成的作用.方法 建立大鼠心肌梗死模型,随机分为4组.A组行超声破坏微泡治疗,B组行单纯超声治疗,C组单纯注射微泡,D组注射生理盐水作为对照,每组均处理3次.4周后取材,免疫组化检测心肌组织中VEGF、CD34表达,ELISA及Western blot检测VEGF表达.结果 A组心肌组织中见大量VEGF和CD34表达,新生血管较多;B组有较少VEGF和CD34表达,新生血管较少;C组和D组仅有极少量VEGF和CD34表达,未见明显新生血管.ELISA检测显示,A组VEGF表达量明显增高[(8.194±1.129)Pg/g],与其他三组[B组(4.339±0.753)Pg/g,C组(2.304±0.762)Pg/g,D组(2.411士0.801)Pg/g]比较,差异均有统计学意义(P＜0.05).Western blot检测显示A组有一条约21 kD的明显的蛋白质条带表达.结论 超声破坏微泡可刺激心肌内源性 VEGF 分泌,促进血管新生.     

超声破坏微泡造影剂促进大鼠心肌血管新生的实验研究

目的探讨超声破坏微泡刺激大鼠心肌内源性VEGF分泌、促进血管生成的新途径。方法正常成年Wistar大鼠30只随机分为3组。第1组超声破坏微泡组，第2组单纯超声辐照组，第3组对照组。每组均进行3次处理。第一次处理3d后每组各取1只大鼠断颈处死后取其心肌，常规HE染色光镜观察心肌结构变化。剩余大鼠于2周后取材，免疫组化检测心肌组织中VEGF表达，CD34免疫组化检测评定超声破坏微泡促进心肌血管新生疗效。结果超声破坏微泡组心肌组织中见大量VEGF和CD34表达，新生血管较多。单纯超声组心肌组织中有较少VEGF和CD34表达，新生血管较少。对照组仅有极少量VEGF和CD34表达，未见明显新生血管。结论超声破坏微泡可刺激心肌内源性VEGF分泌，促进血管新生。     

超声破坏微泡促进骨骼肌血管新生的时间-效应关系研究

目的 探讨超声破坏微泡促进大鼠骨骼肌血管新生的时间-效应关系.方法 将48只SD大鼠随机分为4组(超声破坏微泡组、单纯超声组、单纯微泡组、对照组),超声破坏微泡组经尾静脉输入自制的脂质全氟丙烷微泡造影剂0.5 ml,同时用1.0 MHz、2.0 W/cm2的超声在其大腿骨骼肌局部作用3min;单纯超声组仅在骨骼肌局部用同等的超声能量作用;单纯微泡组仅由尾静脉输入脂质全氟丙烷微泡造影剂0.5 ml;对照组不作任何处理.实验结束后的第3、7、10、14、21、28 d,各组分别取两只大鼠处死,取局部骨骼肌行石蜡切片HE染色观察显微结构的变化,CD34免疫组化计数微血管密度(MVD),酶联免疫吸附试验(ELISA)定量评价血管内皮生长因子(VEGF)的表达.结果 超声破微泡组有较多的血管新生;单纯超声组新生血管较少;单纯微泡组和对照组几乎无血管新生.随着时间的变化,超声破坏微泡组的MVD值和VEGF表达在第10 d达到高峰;单纯超声组的高峰出现在第14 d.结论 超声破坏微泡可刺激骨骼肌中内源性VEGF较快、较多地分泌,从而更好地促进新生血管生成.     

超声介导微泡靶向传输基因促血管新生的实验研究

目的探讨超声介导微泡靶向传输血管内皮生长因子VEGF165促心肌血管新生即心肌“分子搭桥”的新途径。方法利用分子生物学方法构建人血管内皮生长因子真核表达质粒pcDNA3.1-/VEGF165;制备载VEGF165基因脂质体微泡,分析其理化性质和功能,在超声场利用超声辐射向大鼠梗死心肌靶向传输VEGF165;2周后取材,逆转录聚合酶链式反应(RT PCR)评价大鼠心肌中人源VEGF165mRNA表达,蛋白印迹杂交(WesternBlot)观察大鼠心肌VEGF165的蛋白表达,CD34免疫组化微血管密度(MVD)计数半定量法评价超声介导微泡靶向传输VEGF165促梗死心肌血管新生效果。结果①成功构建、克隆血管内皮生长基因VEGF165重组真核表达质粒pcDNA3.1-/VEGF165,测序分析、酶切鉴定准确无误;②研制的脂质体微泡超微结构显示可粘附或包载DNA,粒度分析显示平均粒径<5μm;③在超声介导下该脂质体载基因微泡可靶向传输VEGF165至大鼠梗死心肌,超声介导靶向传输组VEGF165的mRNA、蛋白表达及促血管新生作用(MVD表示)仅次于VEGF165基因心肌注射组。结论超声介导微泡可向大鼠心肌靶向传输VEGF165基因并产生促血管新生效应。     

超声破坏微泡促进骨骼肌血管新生的实验研究

目的　探讨超声破坏微泡引起的微血管破裂促进大鼠骨骼肌血管新生的有效性。方法　将 30只 Wistatr大鼠随机分为 3组 ,1组经静脉输入自制的白蛋白微泡造影剂 0 .5 ml,同时用 1MHz,2 .0 W/cm2 的超声在其骨骼肌局部间歇作用 2 min;1组仅在骨骼肌局部用同等的超声能量作用 ;第 3组作为对照组。实验结束后 ,各组分别取 1只做石蜡切片观察显微结构的变化。各组剩余的大鼠于 2周后处死 ,免疫组化观察骨骼肌中血管内皮生长因子 (VEGF)和血管内皮细胞 因子的表达。结果　超声破坏微泡组大鼠骨骼肌中可见 VEGF和 因子的表达较多 ,有较多的新生血管生成 ;而单纯超声作用组 VEGF和 因子表达较少 ,血管新生不明显 ;对照组中无 VEGF和 因子表达 ,无新生血管。结论　超声破坏微泡引起的微血管破裂可刺激骨骼肌中内源性 VEGF的分泌 ,促进血管生成。     

瑞舒伐他汀对糖尿病大鼠心肌梗死后心肌微血管形成的影响

目的:探讨瑞舒伐他汀对糖尿病大鼠心肌梗死后心肌微血管形成的影响.方法:将糖尿病大鼠随机分为3组:假手术组(A组)、心梗组(B组)、瑞舒伐他汀组(C组).行超声心动图检查;马松染色检测心肌纤维化、免疫组化检测血管内皮生长因子(VEGF)、CD31的表达;RT-PCR检测VEGF mRNA的表达.结果:与A组相比,B组左心室射血分数降低,左心室收缩末期(舒张末期)内径增大、心肌纤维化明显增加(均P＜0.05).与B组相比,C组左心室射血分数升高、左心室收缩末期(舒张末期)内径降低、心肌纤维化明显减少、心肌组织VEGF及CD31表达增加,心肌组织VEGF mRNA表达亦增加(均P＜0.05).结论:瑞舒伐他汀通过促进心肌组织血管形成,进而改善糖尿病大鼠心肌梗死后心功能,其机制可能与VEGF表达上调相关.     

超声微泡造影剂介导VEGF基因治疗大鼠心肌缺血的实验性研究

目的：探讨超声微泡造影剂介导血管内皮生长因子（VEGF）基因转染大鼠缺血心肌的有效性。方法：将15只急性心肌梗塞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pcD2VEGF121基因转染大鼠心肌约6分钟；第二组尾静脉输入同等剂量携pcD2VEGF121基因的造影剂；第三组为对照。2周后，分别行免疫组织化学检测缺血心肌中的VEGF蛋白及毛细血管内皮细胞，结果：采用超声微泡造影剂介导的VEGF基因转染，能明显增强VEGF基因在大鼠心肌组织内的表达，并可促进缺血心肌组织新生血管，结论：超声微泡造影剂介导的VEGF基因治疗是一种无创、新型、高效的基因转移方法。     

活血化瘀法对急性心肌梗死大鼠CD_(34)、血管内皮生长因子阳性细胞的影响

目的研究活血化瘀法对大鼠心肌组织微环境中CD34、血管内皮生长因子(VEGF)的影响,探讨其治疗急性心肌梗死的机制。方法 Sprague-Dawley大鼠32只随机分为假手术组(n=8)、模型组(n=8)、中药+粒细胞集落刺激因子(G-CSF)组(n=8)和G-CSF组(n=8)。各组均于造模3 h后给予相应药物,连续6 d,第7天处死取材。苏木素-伊红(HE)染色观察病理形态,免疫组化染色检测梗死心肌边缘区CD34、VEGF、Ki-67阳性细胞表达。结果模型组、中药+G-CSF组和G-CSF组CD34、VEGF、Ki-67阳性细胞表达均高于假手术组(P0.05);中药+G-CSF组、G-CSF组高于模型组(P0.05);中药+G-CSF组CD34、VEGF阳性表达高于G-CSF组(P0.05),两组Ki-67阳性细胞表达无显著性差异(P0.05)。结论活血化瘀法能够提高CD34和VEGF的表达,其作用优于单独使用G-CSF,可以有效治疗急性心肌梗死。     

超声微泡介导VEGF基因治疗下肢血管闭塞

目的探讨用超声微泡造影剂促进VEGF基因治疗兔下肢缺血的可行性.方法将30只大白兔左股动脉结扎后随机分为3组: A组采用局部注射VEGF质粒DNA; B组采用局部注射VEGF质粒与超声微泡造影剂的混合物;C组作为对照.于治疗后4周进行数字减影血管造影(DSA)和免疫组织化学方法检测侧支循环建立和血管新生.结果 DSA可见用超声破坏微泡后促进侧支循环建立较好,新生血管较多;单纯局部注射质粒可促进部分血管新生,而对照组的侧支循环和新生血管较少.各组免疫组化所测血管计数均有显著性差异.结论用超声微泡介导的VEGF基因转染,可促进缺血骨骼肌的血管新生和侧支循环建立,为下肢缺血性疾病的基因治疗提供了一种新途径.     

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pcD2VEGF121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pcD2VEGF121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.     

超声辐射微泡配合内皮祖细胞移植治疗糖尿病大鼠阴茎勃起功能障碍

目的探讨超声微泡配合内皮祖细胞(EPCs)移植至海绵体组织治疗大鼠糖尿病阴茎勃起功能障碍的可行性。方法体外培养、分离EPCs。将54只成功建立糖尿病勃起功能障碍模型的SD大鼠随机分为空白对照组、EPCs治疗组、1.0W/cm2超声+微泡+EPCs组(US+MB+EPCs治疗组)。EPCs移植7天后,以脱水吗啡(APO)诱导实验检测大鼠阴茎勃起次数和勃起率,组织学观察阴茎海绵体,计数毛细血管数目,计算血管密度,免疫组化检测EPCs移植大鼠阴茎海绵体的情况,Western blot检测VEGF蛋白的表达。结果 US+MB+EPCs治疗组勃起次数和勃起率、毛细血管密度、EPCs染色强度的阳性指数均高于其他两组(P均<0.05),且VEGF蛋白表达水平最高(P<0.05)。结论超声微泡联合EPCs移植可提高EPCs的转染率和靶向性,改善糖尿病大鼠的阴茎勃起功能。     

超声破坏微泡对大鼠皮肤创面愈合影响的实验研究

目的 探讨超声破坏微泡(声诺维)对大鼠皮肤创面愈合的影响.方法 96只SD大鼠建立皮肤创面模型后随机分成4组:超声破坏微泡组、单纯微泡组、单纯超声组和对照组.超声破坏微泡组经鼠尾静脉注射微泡造影剂0.5 ml,同时用声强度1 MHz、2.0 W/cm2超声辐照3 min单纯微泡组经鼠尾静脉注射微泡造影剂0.5 ml;单纯超声组经鼠尾静脉注射生理盐水0.5 ml,同样条件超声辐照3 min对照组经鼠尾静脉注射生理盐水0.5 ml.于创伤后第1、3、5、7、14、21 d利用HE染色和免疫组化方法 观察各组创面肉芽组织生长及血管内皮生长因子(VEGF)表达的情况.结果 HE染色:伤后第7 d,超声破坏微泡组肉芽组织明显比其他3组厚,新生毛细血管均垂直于创面生长,其他3组毛细血管排列紊乱.免疫组化观察VEGF表达变化:超声破坏微泡组在第3 d形成表达高峰,其他3组表达高峰在第5～7 d.结论 超声破坏微泡可以提高大鼠背部皮肤的创面愈合质量;新生肉芽组织成熟早,创面愈合加速.超声破坏微泡时产生的高温、高压及某些化学效应可以刺激内源性VEGF分泌,促进血管生成,从而促进创面愈合.

Abstract：

Objective To investigate the effect of microbubble(Sono Vue) destruction with ultrasound on wound healing in rats. Methods Total 96 SD rats were accepted one rounded whole-layer skin incision on back each other and randomly divided into four groups:microbubble destruction with ultrasound(US + MB),microbubble(MB), ultrasound(US) and control group. Rats in US + MB group were injected with 0.5 ml microbubble contrast agent via tail vein,and then ultrasound irradiated for 3 minutes immediately. MB group were injected with 0.5 ml microbubble contrast agent. US group were injected with 0.5 ml physiological saline,and then ultrasound irradiated for 3 minutes immediately under the same condition. Control group were injected with 0.5 ml physiological saline. Feed each rat in single cage. On day 1,3,5,7,14 and 21 after wound creation,the excised wound tissues were analyzed by histology and VEGF expression in wounds by immunohistochemistry. Results HE staining: On day 7, wounds of US + MB group displayed the most accumulation of granulation tissue and all new capillaries were perpendicular to the wound surface, but the new capillaries of other 3 groups were disordered. Immunohistochemical examination of VEGF expression:the peak expression appeared on day 3 in US + MB group, other 3 groups were on day 5 to day 7.Conclusions US + MB treatment could improve the quality of wound healing and granulation tissues were maturated earlier than MB, US treatment and control group, which could accelerate wound healing. High temperature,high pressure and some kind of chemistry effecs induced by microbubble destruction with ultrasound can stimulate the secretion of endogenous VEGF, which may be the mechanism of promoting angiogenesis and wound healing.     

超声靶向破坏微泡介导骨髓间充质干细胞移植促进大鼠血管新生

目的 探讨超声破坏微泡介导骨髓间充质干细胞(MSCs)移植在大鼠缺血骨骼肌中的作用. 方法 24只Wister大鼠离断右侧股动脉7 d后分为4组:①超声+微泡组(US+MB);②干细胞静脉移植组(MSCs-iv);③超声+微泡+干细胞静脉移植组(US+MB+MSCs-iv);④对照组.处理后第7 d取局部缺血骨骼肌行免疫组化检测. 结果 US+MB+MSCs-iv组缺血骨骼肌可见较多移植的MSCs,其新生血管数量较其他组明显增加. 结论 超声靶向破坏微泡有可能成为一种增强MSCs移植和促进血管新生的新方法 .     

Experimental research on therapeutic angiogenesis induced by hepatocyte growth factor directed by ultrasound-targeted microbubble destruction in rats.

OBJECTIVE: The purpose of this study was to explore the feasibility of therapeutic angiogenesis in myocardial infarction induced by hepatocyte growth factor (HGF) mediated by ultrasound-targeted microbubble destruction. METHODS: Forty Wistar rats were divided into 4 groups after the models of myocardial infarction were prepared: (1) HGF, ultrasound, and microbubbles (HGF+US/MB), (2) HGF and ultrasound, (3) HGF and microbubbles, and (4) surgery alone. Destruction of ultrasound-targeted microbubbles loaded with the HGF gene with an electrocardiographic trigger mode was performed in the HGF+US/MB group. All the rats were killed after being transfected for 14 days. Enhanced green fluorescent protein expression was examined in the myocardium, liver, and kidney in all groups by fluorescence microscopy; CD34 expression was detected by immunohistochemistry, and microvessel density (MVD) was counted in the high-power field on microscopy. Hepatocyte growth factor expression in the myocardium was detected by western blotting and an enzyme-linked immunosorbent assay. RESULTS: Enhanced green fluorescent protein expression was detected in the myocardium of the HGF+US/MB group, but a few areas of HGF expression were detected only in small vessels and the capillary endothelium, and no expression was found in the surgery-alone and HGF and microbubbles groups. The results of MVD counting by microscopy showed that the MVD in the myocardium of the HGF+US/MB group was the highest among all the groups. The results of western blotting and the enzyme-linked immunosorbent assay showed that the amount of HGF in the myocardium was highest in the HGF+US/MB group. CONCLUSIONS: Ultrasound-targeted microbubble destruction could deliver HGF into the infracted myocardium and produce an angiogenesis effect, which could provide a novel strategy for gene therapy of myocardial infarction.     

超声微泡介导血管内皮生长因子基因转染大鼠阴茎组织

目的 探讨超声靶向破坏微泡介导血管内皮生长因子165(VEGF₁₆₅)转染于高脂模型大鼠阴茎海绵体组织的可行性。方法 以含4％胆固醇及1％胆酸饲料饲养36只2月龄雄性SD大鼠3个月,建立大鼠高脂模型,将其随机均分为高脂模型组(对照组)、VEGF₁₆₅组和1.0 W/cm²超声+微泡+VEGF₁₆₅组(US+MB＋VEGF₁₆₅组)。于基因转染后7天处死大鼠,采用荧光定量PCR检测VEGF₁₆₅基因表达水平,以Western Blot检测大鼠阴茎组织VEGF蛋白质的表达水平,用免疫组织化学法(IHC)检测大鼠阴茎组织内皮型一氧化氮合成酶(eNOS)蛋白质表达。结果 转基因7天后,US+MB＋VEGF₁₆₅组VEGF₁₆₅基因水平明显高于VEGF₁₆₅组及对照组(P均<0.05),其阴茎海绵体组织VEGF蛋白质表达较VEGF₁₆₅组及对照组增加(P均<0.05);IHC结果显示,US+MB＋VEGF₁₆₅组大鼠阴茎组织eNOS较其他组高表达(P均<0.05)。结论 超声靶向破坏微泡可介导VEGF₁₆₅基因在大鼠高脂模型阴茎海绵体组织的高效转移,为基因治疗高脂勃起功能障碍提供了实验依据。     

不同强度超声破坏微泡对犬心肌组织的生物学效应

目的 探讨不同强度的超声破坏微泡对犬心肌组织的生物学效应,优化出影响心肌微环境的最佳辐照条件.方法 9只健康成年杂种犬随机分成3组,每组3只.静脉输入2 ml微泡造影剂,同时采用频率为1 MHz,强度不同的超声辐照(0.5 W/cm2、1.0 W/cm2、2.0 W/cm2)犬心肌组织,辐照时间为5 min.辐照完毕后即刻处死动物,取局部心肌组织.进行病理组织HE染色和透射电镜观察犬心肌细胞及毛细血管内皮细胞等细胞超微结构改变.结果 0.5 W/cm2超声破坏微泡后心肌组织水肿,无出血;1.0 W/cm2超声破坏微泡后心肌组织轻微出血和少量炎症细胞浸润;2.0 W/cm2超声破坏微泡后心肌组织明显出血,炎症细胞一定程度浸润.结论 不同强度超声破坏微泡造影剂能使犬心肌组织产生不同程度的生物学效应;超声强度在1.0～2.0 W/cm2能在使心肌轻度损伤时引起一定程度的炎症反应.     

Granulocyte colony-stimulating factor facilitates the angiogenesis induced by ultrasonic microbubble destruction

Ultrasonic destruction of microbubbles (US/MB) in the microcirculation causes local inflammatory cell infiltration, which has been shown to induce angiogenesis. Granulocyte colony-stimulating factor (G-CSF), which mobilizes myelomonocytic cells from the bone marrow and enhances vascular endothelial growth factor (VEGF) release from these cells, has also been applied to therapeutic angiogenesis induction. In the present study, we sought to examine the potential of G-CSF pretreatment to enhance the angiogenic effect of US/MB. Ischemic hindlimbs in mice were treated with either a predetermined minimal effective dose (300 mug/kg) of G-CSF, US/MB alone or G-CSF pretreatment followed by US/MB at seven days after removal of the femoral artery. Ultrasonic destruction of microbubbles was performed as intermittent pulsed local insonation using a diagnostic ultrasound scanner at a peak negative pressure of 1.4 MPa after intravenous injection of perfluorocarbon microbubbles. At 21 days after the treatment, we quantified the surface vascularity using a grid method and the capillary density using an alkaline phosphatase stain. Relative to the capillary density in normal muscle, the capillary density in the treated limbs was restored to 74 +/- 13% by G-CSF alone and 90 +/- 20% by US/MB alone (p < 0.05 vs. both untreated and G-CSF alone), and further increased to 101 +/- 21% by G-CSF pretreatment. The collateral growth induced by the combination of G-CSF pretreatment and US/MB was 2.8- and 1.4-fold greater than the growth induced by G-CSF alone and US/MB alone, respectively (p < 0.05 for both). Thus, pretreatment with a single minimal effective dose of G-CSF can augment the angiogenic effect of US/MB.     

Ultrasound-Mediated Microbubble Cavitation Transiently Reverses Acute Hindlimb Tissue Ischemia through Augmentation of Microcirculation Perfusion via the eNOS/NO Pathway

Ultrasound-mediated microbubble cavitation improves perfusion in chronic limb and myocardial ischemia. The purpose of this study was to determine the effects of ultrasound-mediated microbubble cavitation in acute limb ischemia and investigate the mechanism of action. The animal with acute hindlimb ischemia was established using male Sprague-Dawley rats. The rats were randomly divided into three groups: intermittent high-mechanical-index ultrasound pulses combined with microbubbles (ultrasound [US] + MB group), US alone (US group) and MB alone (MB group). Both hindlimbs were treated for 10 min. Contrast ultrasound perfusion imaging of both hindlimbs was performed immediately and 5, 10, 15, 20 and 25 min after treatment. The role of the nitric oxide (NO) pathway in increasing blood flow in acutely ischemic tissue was evaluated by inhibiting endothelial nitric oxide synthase (eNOS) with N^ω-nitro-L-arginine methyl ester hydrochloride (L-NAME). In the US + MB group, microvascular blood volume and microvascular blood flow of the ischemic hindlimb were significantly increased after treatment (both p values <0.05), while the microvascular flux rate (β) increased, but not significantly (p > 0.05). The increases were observed immediately after treatment, and had dissipated by 25 min. Changes in the US and MB groups were minimal. Inhibitory studies indicated cavitation increased phospho-eNOS concentration in ischemic hindlimb muscle tissue, and the increase was significantly inhibited by L-NAME (p < 0.05). Ultrasound-mediated microbubble cavitation transiently increases local perfusion in acutely ischemic tissue, mainly by improving microcirculatory perfusion. The eNOS/NO signaling pathway appears to be an important mediator of the effect.     

Microbubble-Facilitated Ultrasound Catheter Ablation Causes Microvascular Damage and Fibrosis

High-intensity ultrasound (US) ablation produces deeper myocardial lesions than radiofrequency ablation. The presence of intravascular microbubble (MB) contrast agents enhances pulsed-wave US ablation via cavitation-related histotripsy, potentially facilitating ablation in persistently perfused/conducting myocardium. US ablation catheters were developed and tested in the presence of MBs using ex vivo and in vivo models. High-frame-rate videomicroscopy and US imaging of gel phantom models confirmed MB destruction by inertial cavitation. MB-facilitated US ablation in an ex vivo perfused myocardium model generated shallow (2 mm) lesions and, in an in vivo murine hindlimb model, reduced perfusion by 42% with perivascular hemorrhage and inflammation, but no myonecrosis.