Local Angiopeptin Delivery Using Coated Stents Reduces Neointimal Proliferation in Overstretched Porcine Coronary Arteries

BACKGROUND: Systemic administration of angiopeptin has been shown to inhibit myointimal thickening after arterial injury in several animal species. METHODS AND RESULTS: To explore to what extent high and long-lasting local concentrations of angiopeptin influence the healing process after vascular injury, tantalum balloon-expandable stents were first coated with a polymer loaded with angiopeptin 250 μg. Implantation of these stents in porcine coronary arteries resulted in tissue concentrations of 10.7 pg/ml wet weight in the stented arterial segment 24 hours after stent implantation, gradually declining to 2.0 pg/ml wet weight at day 8. Finally, 20 pigs were randomly treated with either an angiopeptin-loaded or a blank-coated stent. At baseline, the angiographic parameters were similar between both groups but, after 6 weeks, the minimal luminal diameter of the stented arterial segment was larger in the angiopeptin-treated pigs when compared to controls (2.20 +/- 0.57 mm vs 1.57 +/- 0.68 mm, p < 0.01) This angiographic finding was confirmed by post-mortem morphometry where the respective lumen area values were 1.00 +/- 0.54 mm2 and 0.43 +/- 0.28 mm2 (p < 0.01). CONCLUSION: Polymer coated stents can be loaded with angiopeptin, which after implantation in porcine right coronary arteries result in high local tissue concentrations gradually declining over more than 8 days. These high local concentrations inhibit myointimal proliferation induced by poly(organo)phosphazene coated overstretched stents.     

Local Delivery of Antithrombotic Drug Inhibits Neointimal Hyperplasia Following Arterial Injury

The efficacy of local delivery of antithrombotic drugs on neointimal hyperplasia was investigated in 41 rabbits. One side of a rabbit iliac artery was injured by a balloon catheter as a control-injured artery. Another side of the iliac artery was also injured, and followed by local delivery of the antithrombotic drug (argatroban: 0.05 mg/kg; heparin 25 U/kg; or batroxobin 1 U/kg + heparin 25 U/kg). One hour after the balloon injury, angioscopy demonstrated occlusive or mural thrombus in all the controls, but few in the local drug-delivery arteries. Four weeks after balloon injury, angiographic percent stenosis in the locally drug-delivered arteries was 8%± 2% in the argatroban group (n = 7. P < 0.001 vs control side; 67%± 33%), 25%± 19% in the heparin group (n = 5, P < 0.005 vs control 66%± 14%), and 5%± 5% in the batroxobin group (n = 7, P < 0.01 vs control 59%± 39%). The activated partial thromboplastin time and fibrinogen did not change significantly. The PDGF-B chain was prominent at the neointimal layer in all the controls, but less so in the locally drug-delivered arteries. Thus, local delivery of antithrombotic drugs can inhibit neointimal hyperplasia after balloon injury by reducing thrombus related growth stimulation.     

血管紧张素Ⅱ2型受体介导抑制大鼠颈动脉新生内膜增生的机制

目的:探讨血管紧张素Ⅱ2型受体(AT2R)介导抑制新生内膜增生作用的机制。方法:大鼠颈动脉球囊损伤后,局部转染带有大鼠AT2R基因重组腺病毒转染(pAdCMV／AT2R)或空载腺病毒转染 (pAd-GFP),分正常组(6只)、未转染组(18只)、pad-GFP组(18只)、pAdCMV／AT2R组(18只)。于术后7、14、21天取材,用逆转录一多聚酶链反应、Western印迹杂交检测AngⅡ1型受体(AT1R)、AT2R、胞外调控激酶1和2、基本转录元件结合蛋白2在大鼠颈动脉壁中的表达变化。结果:未转染组和pad-GFP组AT1R、AT2R、胞外调控激酶1和2、基本转录元件结合蛋白2的7、14、21天mRNA及蛋白表达显著高于正常组,pAdCMV／AT2R组AT2R的表达显著高于正常组、未转染组和pAd-GFP组(P<0．01),胞外调控激酶1和2、基本转录元件结合蛋白2的表达显著低于未转染组和pAd-GFP组(P<0．01),而AT1R的表达在未转染组、pAd-GFP组、pAdCMV／AT2R组无显著差异(P>0．05)。结论:AT2R灭活AT1R激活的胞外调控激酶1和2,降低基本转录元件结合蛋白2表达,可能是AT2R介导抑制新生内膜形成的机制之一。     

Angiotensin II Release From Rabbit Intrarenal Arteries: A Critical Assessment

A microdissected rabbit intrarenal arterial network (IAN) perfused at constant flow with Krebs-bicarbonate solution was employed to determine whether this network, which has a high renin content, releases angiotensin II (AII) either spontaneously or during β-adrenergic stimulation. Six groups of experiments were conducted in which samples of the vascular effluent were collected on Sep Paks before and during intraluminal infusion of L-isoproterenol (1.1 to 11 μg/min). Separation and assay of AII were by combined HPLC and RIA. For an accurate estimation of the quantity of AII released, it was important to subtract the Krebs and isoproterenol blanks, 19 and 23 pg, respectively, from the basal and isoproterenol-induced AII release. In Groups 1 and 2, AII release was determined before and during isoproterenol infusion (5.5 μg/min). Basal release of AII was insignificant in Groups 1 to 5. In Group 1, infusion of isoproterenol caused AII release from IAN before and after removal of glomeruli (glomerulectomy), but with variability between experiments. An even higher infusion rate of isoproterenol (11 μg/min) in Group 2 caused no significant AII release. Similarly, in Group 3, in which a longer collection period was imposed, isoproterenol (5.5 μg/min) failed to cause significant AII release. In Groups 4 and 5, Goldblatt hypertensive and salt-restricted rabbits, respectively, isoproterenol caused AII release, but the effect was statistically significant only in Group 4. Supplying renin substrate in Group 6 caused only a small spontaneous AII release. We conclude that under these conditions of complete isolation from the intact circulation, the IAN despite a high renin content, releases little locally generated AII.     

CBP基因沉默对大鼠颈动脉球囊损伤后内膜增生的影响

目的 观察小干扰RNA (siRNA)重组慢病毒介导的CREB结合蛋白(CBP)基因沉默对大鼠颈动脉球囊损伤后新生内膜增生的影响,并探讨其作用机制.方法 雄性SD大鼠48只,随机分为4组:假手术组、PBS对照组、慢病毒介导CBP基因siRNA转染组(CBP-siRNA-Lenti组)及慢病毒介导非CBP同源序列siRNA转染组(NC-siRNA-Lenti组),建立大鼠颈动脉球囊损伤模型,术后28天处死动物.分别用实时定量PCR、Western Blot检测大鼠颈动脉CBP和乙酰化核因子κB p65(NF-κB p65)的表达水平;病理组织学观察血管内膜增生情况;免疫组织化学染色对损伤血管壁增殖细胞核抗原(PCNA)的表达进行评估.结果 术后28天,与PBS对照组和NC-siRNA-Lenti组比较,CBP-siRNA-Lenti组CBP mRNA和蛋白的表达显著下调(P均＜0.05),CBP沉默能明显抑制新生内膜面积(0.108 ±0.008 mm2比0.238±0.022 mm2、0.252±0.016 mm2,P ＜0.05)、内膜与中膜面积比(0.706±0.062比1.483 ±0.136、1.497±0.137,P＜0.05)的增加,及下调血管壁乙酰化NF-κB p65和PCNA的表达水平(P均＜0.05).结论 慢病毒介导的CBP基因沉默能有效地抑制颈动脉球囊损伤后新生内膜的形成,其机制可能与抑制NF-κB p65的过度乙酰化有关.     

同型半胱氨酸与血管成形术后新内膜增生的研究进展

同型半胱氨酸是一种含硫的非必需氨基酸 ,其在血管动脉粥样硬化中的作用已得到大量资料证实。近来发现其有促进血管成形术后血管内膜增生的作用 ,从而促进血管再狭窄。高同型半胱氨酸不仅具有抑制血管内皮损伤后内皮修复的作用 ,而且有促进内皮下血管平滑肌细胞增殖及迁移的作用 ,这可能是其促进血管成形术后新内膜增生的机制。     

雷帕霉素药物洗脱支架对糖尿病小型猪冠状动脉支架置入后内膜增生的影响

目的:评估雷帕霉素药物洗脱支架(SES)对糖尿病小型猪冠状动脉支架置入后内膜增生的作用.方法:建立链脲菌素诱导的糖尿病小型猪模型(糖尿病组,n=12),随机选取2支冠状动脉置入SES,共计置入24枚支架,术后饲养6个月,与非糖尿病置入SES支架的小型猪模型(对照组,n=12)比较冠状动脉造影、血管内超声及组织切片检查结果.结果:两组动物支架置入冠状动脉分布,术前参照血管直径[糖尿病组:(2.78±0.35)mm,对照组:(2.81±0.29)mm]及术后即刻最小管腔内径[糖尿病组:(2.90±0.42)mm,对照组:(2.89±0.33)mm]均相似(P均>0.05).术后6个月糖尿病组支架内狭窄程度[(35.6±9.2)%和(7.9±3.1)%,P<0.001]、支架内晚期管腔丢失[(0.32±0.09)mm和(0.09±0.04)mm,P<0.001]、新生内膜厚度[血管内超声:(0.35±0.12)mm和(0.11±0.08)mm,P<0.05]及新生内膜面积[血管内超声:(1.29±0.51)mm~2和(0.26±0.11)mm~2,P<0.001;组织切片:(1.24±0.76)mm~2和(0.19±0.08)mm~2,P<0.05]均显著高于对照组.结论:糖尿病小型猪冠状动脉置入SES后内膜增生程度显著高于无糖尿病模型.     

In-Stent Restenosis: Contributions of Inflammatory Responses and Arterial Injury to Neointimal Hyperplasia

Objectives. We examined the relative contributions of inflammation and arterial injury to neointimal formation in a porcine coronary overstretch restenosis model.Background. Previous studies established that stents cause neointimal proliferation proportional to injury. Although inflammation has been postulated to be a major contributor to restenosis after angioplasty, there is a paucity of data on the relation between inflammation and subsequent neointimal formation.Methods. Twenty-one pigs underwent balloon injury followed by implantation of oversized, tubular, slotted stents (stent/artery ratio 1.2:1) in the left anterior descending coronary artery. Morphometric analysis of the extent of injury (graded as injury score 0 to 3) and inflammation (graded as inflammation score 0 to 3) 1 month later was assessed and correlated with neointimal formation.Results. An inflammatory reaction was observed in 20 of 21 pigs, and significant positive correlations were found between the degree of arterial injury and the extent of the inflammatory reaction (r = 0.80, p < 0.01) and between the extent of inflammatory reaction and the neointimal thickness (r = 0.75, p < 0.01), neointimal area (r = 0.53, p = 0.01) and percent area stenosis (r = 0.66, p < 0.01) within the stents. Importantly, there were areas with inflammation only in the absence of injury, and vice versa, that were also associated with neointimal hyperplasia.Conclusions. These data suggest that the inflammatory reaction plays an equally important role as arterial injury in neointimal formation after coronary stenting, and that anti-inflammatory approaches may be of value to reduce in-stent restenosis.     

斑蝥素对大鼠颈动脉球囊损伤后新生内膜增生的影响

目的:通过细胞培养及建立大鼠颈动脉球囊损伤模型,探讨斑蝥素对血管内皮损伤后新生内膜增生的作用及机制。方法:采用组织块贴壁法体外培养SD大鼠胸主动脉血管平滑肌细胞(VSMC),以脂多糖(LPS)作为刺激因素,选择吡咯烷二硫代氨甲基甲酸盐(PDTC)作为核转录因子(NF-κB)信号通路抑制剂,将VSMC分为对照组、1μg/ml LPS刺激组(LPS组)、LPS刺激后加用5μmol/L斑蝥素组(斑蝥素组)、LPS刺激后加用80μmol/L PDTC处理组(PDTC组)、LPS刺激后加用5μmol/L斑蝥素和80μmol/L PDTC处理组(斑蝥素+PDTC组)共5组;应用伤口愈合实验和Transwell实验检测斑蝥素对VSMC迁移的影响,蛋白免疫印迹法(Western blot)检测斑蝥素对NF-κB p65、磷酸化NF-κB p65(p-p65)和基质金属蛋白酶9(MMP-9)表达的影响。采用Fogarty(2 F)球囊导管建立大鼠颈动脉球囊损伤模型,SD大鼠随机分为假手术组、损伤组、斑蝥素(2 mg/kg)组,各组于造模前1周开始腹腔注射给药,连续给药3周,术后14 d取血检测血清肿瘤坏死因子α(TNF-α)及白细胞介素-6(IL-6)的水平,同时取损伤颈动脉进行苏木精-伊红染色、免疫组织化学法检测MMP-9、NF-κB p65、TNF-α及IL-6的表达。结果:伤口愈合实验和Transwell实验结果显示,LPS组细胞的迁移能力显著增强(P<0.01);与LPS组比较,斑蝥素组、PDTC组、斑蝥素+PDTC组细胞迁移能力均受到抑制(P<0.01),另外与斑蝥素组比较,斑蝥素+PDTC组细胞迁移未见差异(P>0.05)。Western blot结果显示,与对照组比较,LPS组细胞p-p65和MMP-9表达增加,斑蝥素组或PDTC组表达显著降低(P均<0.05);与斑蝥素组比较,斑蝥素+PDTC组中p-p65和MMP-9表达未见差异(P均>0.05)。在大鼠颈动脉球囊损伤模型中,损伤组大鼠血清内TNF-α和IL-6浓度明显升高,斑蝥素组大鼠血清中TNF-α和IL-6浓度较损伤组显著降低(P均<0.05);损伤组大鼠颈动脉内膜增生明显,斑蝥素组较损伤组内膜面积、内膜面积/中膜面积减小(P均<0.05);与损伤组比较,斑蝥素组血管内膜中MMP-9、NF-κB p65、TNF-α和IL-6的表达明显降低(P均<0.05)。结论:斑蝥素对LPS诱导的VSMC的迁移以及对受损大鼠颈总动脉内膜的增生具有显著的抑制作用;其机制主要与抑制NF-κB信号通路介导的炎症反应密切相关。     

Measurement of Heparin in Patients Receiving Subcutaneous Heparin Therapy

Heparin assays based on four different tests of clotting function have been compared with a heparin assay utilizing the potentiating effect of heparin on anti-factor Xa in a group of patients receiving subcutaneous heparin therapy during late pregnancy. It is considered that the anti-factor Xa method is a better indication of the antithrombotic effect of heparin. In the presence of high levels of clotting factors, heparin assays based on tests of clotting function can be misleading.     

Norepinephrine Release in Arteries of Spontaneously Hypertensive Rats

The role of the sympathetic nervous system in arterial hypertension cannot be properly evaluated until we know about its activity in the vessels themselves. In this study we investigated the effect of transmural stimulation on the tail artery - labelled in vitro with ³H-norepinephrine - of 7-9 week old spontaneously hypertensive rats (SHR) and Wistar Kyoto controls (WKR). Electrical stimulation using two frequencies (2 and 10 Hz) resulted in significantly more ³H overflow in vessels from SHR than from WKR. With 10 Hz stimulation the fractional release was also greater. Column chromatographic analysis of ³H overflow revealed that transmural stimulation in arteries of SHR enhanced mainly the release of norepinephrine and not of its metabolites. Significantly, an increased release of ³H-norepinephrine on stimulation was observed in SHR before the full development of hypertension suggesting that it might be a cause rather than a consequence of high blood pressure.     

Overlapping Coronary Stents Result in an Increased Neointimal Hyperplasia: Insight from a Porcine Coronary Stent Model

Clinical experience suggests that overlapping coronary stents result in an increased in-stent restenosis. This study investigates the underlying mechanisms in a porcine coronary model. Single or two overlapping self-made stainless steel single wire sinusoidal helical coil stents were randomly deployed in the right coronary artery of 20 cross-bred pigs. The pigs underwent a control angiogram at 6 weeks and were then sacrificed. Quantitative coronary analysis before, immediately after stent implantation, and at 6 weeks was performed using the semiautomated Polytron 1000 system. Morphometry was performed using a computerized morphometric program. Angiographic analysis revealed a decreased recoil in the overlapping group (1% vs 4%: P < 0.02) and a significantly larger minimal stent lumen diameter at follow-up in the single stent group (2.87 ± 0.16 vs 2.58 ± 0.22 mm, P = 0.005). Histopathology showed a significantly increased injury (1.27 ± 0.43 vs 0.83 ± 0.44, P = 0.042) and inflammatory reaction (1.51 ± 0.11 vs 1.09 ± 0.54, P = 0.035) surrounding the stent filaments in the overlapping stent group. Morphometric analysis showed a significantly higher neointimal hyperplasia (3.34 ± 0.68 vs 2.16 ± 1.48 mm², P = 0.034) in the overlapping stent group. Overlapping stents result in a more pronounced coronary vessel injury resulting in more inflammation and neointimal hyperplasia compared to single stents.     

非诺贝特对自发性高血压大鼠颈动脉球囊损伤后内膜增生的影响

目的观察微粒化非诺贝特对自发性高血压大鼠(Spontaneouslyhypertensiverats,SHR)颈动脉球囊损伤后动脉内膜增生的影响。方法球囊损伤造成大鼠颈动脉内膜剥脱后,将27只大鼠随机分为3组,1组给予标准饲料,其余2组分别给予高脂饲料、高脂饲料 非诺贝特100mg/kg.d灌胃。用药时间为3月。3月后,腹主动脉取血,以备血脂的测定,并立即行腹主动脉插管灌注固定颈总动脉,HE染色,用图像分析仪观察颈总动脉血管腔面积(L)、血管壁(中膜)面积(W),并计算其比值(W/L)。结果(1)与标准饲料组相比,高脂饲料组SHR体重和血浆甘油三酯(TG)、胆固醇(TC)水平明显增高,高密度脂蛋白胆固醇(HDL-C)水平明显降低(P<0.05),非诺贝特治疗组与标准饲料组比较血压明显下降,HDL-C明显升高,体重、TG及TC水平无明显差异。(2)颈总动脉健侧各组W/L无明显差异;损伤侧高脂饲料组比标准饲料组明显增厚(0.36±0.03比标准饲料组0.27±0.04,P<0.05),局部有斑块形成。结论非诺贝特可降低SHR体重、血压,改善SHR血脂水平,减缓SHR颈动脉球囊损伤后内膜增生,延缓动脉粥样硬化进程。     

非诺贝特对自发性高血压大鼠颈动脉球囊损伤后内膜增生的影响

目的 观察微粒化非诺贝特对自发性高血压大鼠(Spontaneously hypertensive rats,SHR)颈动脉球囊损伤后动脉内膜增生的影响.方法 球囊损伤造成大鼠颈动脉内膜剥脱后,将27只大鼠随机分为3组,1组给予标准饲料,其余2组分别给予高脂饲料、高脂饲料 非诺贝特100 mg/kg·d灌胃.用药时间为3月.3月后,腹主动脉取血,以备血脂的测定,并立即行腹主动脉插管灌注固定颈总动脉,HE染色,用图像分析仪观察颈总动脉血管腔面积(L)、血管壁(中膜)面积(W),并计算其比值(W/L).结果 (1)与标准饲料组相比,高脂饲料组SHR体重和血浆甘油三酯(TG)、胆固醇(TC)水平明显增高,高密度脂蛋白胆固醇(HDL-C)水平明显降低(P＜0.05),非诺贝特治疗组与标准饲料组比较血压明显下降,HDL-C明显升高,体重、TG及TC水平无明显差异.(2)颈总动脉健侧各组W/L无明显差异;损伤侧高脂饲料组比标准饲料组明显增厚(0.36±0.03比标准饲料组0.27±0.04,P＜0.05),局部有斑块形成.结论 非诺贝特可降低SHR体重、血压,改善SHR血脂水平,减缓SHR颈动脉球囊损伤后内膜增生,延缓动脉粥样硬化进程.     

自聚肽承载的Ephrin-b2/Fc重组蛋白在心肌梗死治疗中的缓释效应

目的通过体外观测和体内实验探讨自聚肽RAD16-Ⅱ对Ephrin-b2/Fc重组蛋白的控制释放效应及其免疫原性,解决心肌梗死蛋白质治疗中裸露的蛋白质在机体有效作用时间短且易被降解的问题。方法体外观测RAD16-Ⅱ的塑型及对Ephrin-b2/Fc重组蛋白的控制释放;构建SD大鼠心肌梗死模型,将存活大鼠分为2组分别予心肌内注射Ephrin-b2/Fc蛋白(E组,n=25)和自聚肽Ephrin-b2/Fc蛋白凝胶(ES组,n=25),在设定的时间点(1 h,3h,24 h,7 d,14 d)各收集心肌组织和血清样本5个,分别用免疫荧光和免疫印迹技术检测eprhin-b2蛋白驻留和丢失情况;皮下注射RAD16-Ⅱ,5 W后ELISA法检测血清抗体滴度,评估RAD16-Ⅱ的免疫原性。结果 RAD16-Ⅱ在PBS中可自我聚合组装成纳米纤维网状结构;这种结构在体外可使Ephrin-b2/Fc重组蛋白的释放持续144 h,其中超过50%量在120 h内释放;免疫荧光显示除注射后1 h外,Ephrin-b2/Fc蛋白在ES组的驻留量明显高于同期的E组(P0.05);免疫印迹显示注射早期,ES组Ephrin-b2/Fc蛋白的血液释入量明显少于同期的E组(P0.05);ELISA法检测血清抗RAD16-Ⅱ抗体效价与阴性对照组无显著差异。结论 RAD16-Ⅱ可明显地延缓Ephrin-b2/Fc重组蛋白的释放,是承载Ephrin-b2/Fc蛋白用于心肌梗死治疗和缺血性研究的较为可靠和安全的生物载体材料。     

支气管动脉栓塞术治疗大咯血的疗效分析

报道 14例大咯血患者行支气管动脉栓塞术 ,即刻出血率 5 7.1% ,经 1个月和 3个月随访观察 ,其止血率分别为 85 .7%和 78.6 %。对支气管动脉栓塞术的应用价值、栓塞材料与方法的选择、适应证、并发症及其预防等进行了讨论     

Prenatal Diagnosis of Transposition of the Great Arteries Reduces Postnatal Mortality: A Population-Based Study

BackgroundTransposition of the great arteries (TGA) may present as a life-threatening neonatal malformation. Although prenatal detection facilitates the perinatal management, the impact on outcome is controversial.MethodsThis study reviewed the differences in prenatal diagnosis of TGA from 2009 to 2014 among the 5 geographic areas in Ontario and compared the management, morbidity, and mortality among neonates with a prenatal (prenatal cohort; n = 70) vs a postnatal (postnatal cohort; n = 76) anomaly diagnosis. Cases were identified from prospective databases of the provincial cardiac tertiary centres and the coroner’s office.ResultsPrenatal TGA detection rates varied significantly among areas (median: 50%; range: 14% to 72%; P = 0.03). Compared with the postnatal cohort, time from birth to tertiary care admission (1.4 vs 10.4 hours, P < 0.001), prostaglandin therapy (0.1 vs 5.3 hours; P < 0.001), balloon atrial septostomy (5.3 vs 14.9 hours; P <0.001), and arterial switch operation (6 vs 9 days, P = 0.002) was significantly shorter in the prenatal cohort. Although other preoperative variables—including the need of ventilation and mechanical support, morbidity score, and lowest pH and preductal oxygen saturations—were comparable, a prenatal diagnosis was associated with improved 1-year survival (odds ratio: 0.108; 95% confidence interval, 0.013-0.88; P = 0.0184).ConclusionsPrenatal diagnosis of TGA significantly shortened time intervals from birth to neonatal care and surgery and was associated with improved survival. The prenatal detection rate of TGA in Ontario was low (50% or less) outside of Metropolitan Toronto, suggesting the need for new strategies to further improve intraprovincial detection rates.     

Self-Help Large-Group Therapy for Alcoholism: A Controlled Study

An innovative approach to ambulatory alcoholism treatment is proposed, based on adapting a self-help modality to the institutional clinic setting, for more cost-effective care. It draws on the principles of social influence in large groups, and diffuses the therapist's perogatives among more advanced patients. The program thereby operates with half the usual counseling staff. In this study (n = 235), a controlled comparison of this approach was made with more conventional clinic treatment, based on small-group therapy. Retention and visit rates of the experimental patients over 1 year of care were no different from the control patients, and engagement of inpatients into ambulatory care was more effective.