长期体外反搏对冠状动脉闭塞犬的促血管新生作用研究

目的 探索长期体外反搏对冠状动脉闭塞犬心肌微血管和血管新生作用的影响以及对循环和心肌局部血管内皮生长因子(VEGF)表达的影响.方法 雄性Beagle犬12只,随机分为对照组(n=6)和反搏组(n=6),均用心导管法建立定向冠状动脉闭塞模型3 d后,反搏组接受体外反搏处理,每日1 h,持续共6周(每只犬反搏总时间28～30 h).血管细胞成分免疫标记技术比较心肌微血管的差异和血管新生作用.双抗体夹心ELISA法测定犬血清VEGF水平动态变化.免疫组化SP法(链霉菌抗生物素蛋白-过氧化酶免疫组化染色超敏法)测定心肌组织局部VEGF的表达.RT-PCR检测心肌组织局部VEGF Mrna的表达.结果 (1)图像分析证实,反搏组犬缺血心肌组织内的微血管的数量显著高于对照组[α-actin:(11.8±5.3)支/HP比(3.4 ±1.2)支/HP,P＜0.05 ;FⅧ-r-Ag :(15.2±6.3)支/HP比(4.9±2.1)支/HP, P＜0.05].(2)冠状动脉急性闭塞后,两组犬的血清VEGF水平开始升高,在24 h均达到一峰值水平,随后VEGF水平下降,约在1周时降至最低.之后两组犬的血清VEGF水平有轻微增加,但组间变化差异无统计学意义.(3)反搏组犬缺血心肌组织的VEGF表达范围较广泛,但绝大部分仍分布于心肌细胞,少数分布于血管内皮细胞和成纤维细胞.相反,在对照组,心肌VEGF阳性表达的范围和强度均不及反搏组.(4)免疫组化图像分析发现,反搏组犬心肌VEGF表达的面积[(0.0353±0.0090)mm2比(0.0036±0.0008)mm2,P＜0.01]、吸光度指数[(3.0391±0.5121)比(0.3473±0.0840),P＜0.01)]均高于对照组;对两组心肌组织VEGF Mrna的表达进行半定量分析,结果反搏组犬心肌VEGF Mrna的表达显著高于对照组(P＜0.01),增加73.5%.结论 长期体外反搏治疗促进冠状动脉侧支循环和新生血管形成,促进缺血心肌组织局部VEGF蛋白和Mrna水平的表达可能是体外反搏的治疗机制之一.     

增强型体外反搏对犬急性心肌缺血时血管紧张素转换酶的影响

目的：探讨增强型体外反搏（ＥＥＣＰ）对我急性心肌缺血犬循环及局部组织中血管张素转换酶（ＡＣＥ）的影响。方法：结扎犬冠脉 左前降支造成急性心肌缺血模型,用紫外分光光度法测徨及局部组织ＡＣＥ活性。结果：急性心肌缺血时循环ＡＣＥ持续上升,１６５min时,上升幅度趋于平缓,经反搏治疗后６０min,未见对ＡＣＥ有影响,１２０min时ＡＣ Ｅ睛降,但仍高于下沉水平。局部ＡＣＥ在缺血时均被激活,反搏１２０min后,各组织Ａ     

体外反搏对急性缺血犬动脉剪切应力影响的实验研究

为研究体外反搏对心肌缺血的治疗机理。分别测量在正常情况下,缺血１小时,缺血２小时、缺血１小时反反搏１小时、反搏２小时犬头臂干、颈动脉、胸主动脉、腹主动脉处的实时血流量,而后通过数学计算得出各处的实时剪切应力,结论是急性心肌缺血使各处动脉血管剪切应力的脉动性下降;体外反搏的作用可增加各处动脉剪切应力的脉动性。     

体外反搏对剪切应力影响的实验研究

为了研究体外反搏治疗心肌缺血的机理,本研究从六条开胸犬实时测量颈主动脉、头臂干、胸主动脉等处的血流量,并计算出各处的剪切应力的变化。统计结果表明：体外反搏使剪切应力的平均值、变化范围及变化速度都发生了变化,即增加了血流和剪切应力的脉动性。     

体外反搏对失血性休克犬大脑和皮肤微血管血流灌注的作用

应用激光多普勒测定微血管血流灌注技术，观察体外反搏提高灌注压力对失血性休克犬大脑皮层及皮肤微血管血流灌注的作用。结果显示，体外反搏可明显提高休克犬主动脉平均压力，增加休克犬大脑皮层及皮肤微血管血流灌注。在回输失血复苏后，对照组和反搏组主动脉平均压力恢复接近失血前水平，但反搏组微血管灌注的回升却明显高于对照组。结果提示体外反搏在犬失血性休克期预处理能改善其微循环障碍，有利于复苏期微血管的灌注     

体外反搏对犬血流脉动性和血管阻力的影响

为了评价体外反搏是否具有扩张血管和增加血流脉动性的作用 ,制造了犬急性心肌梗塞模型 ,并使犬存活 6周。麻醉后 ,测定左侧颈总动脉血流量和右侧颈总动脉血压。计算反搏前和反搏中脉压差、血压脉动指数、血压的标准差、流量差、流量脉动指数、流量标准差和平均血管阻力。结果显示脉压差、血压脉动指数和血压标准差三个血压脉动性指标分别由反搏前的 30± 9mm Hg、1.2 6± 0 .0 5、8.7± 2 .5 mm Hg升高到反搏中的 4 3± 8mm Hg(P<0 .0 5 )、1.5 4± 0 .13、12 .4± 2 .0 mm Hg (P<0 .0 5 )。流量差、流量脉动指数和流量标准差三个血流脉动性指标分别由反搏前的 317± 4 8ml/ min、2 .85± 0 .2 1、96± 2 1ml/ min升高到反搏中的 4 4 7± 88m l/ min、4 .5 6± 0 .90、131±39m l/ m in,P值均于小 0 .0 5。平均血管阻力由反搏前的 5 78± 72 Wood单位降低到反搏中的 4 76± 85 Wood单位(P<0 .0 5 )。这表明体外反搏可使血管阻力下降 ,血压和血流脉动性增强。     

体外反搏对典型冠状动脉疾病作用效果的集中参数建模仿真

目的 研究增强型体外反搏（enhanced external counter pulsation,EECP）疗法对典型冠脉血管病及微血管心绞痛的血流动力学影响。方法 使用集中参数建模方法,建立包含导管动脉与心肌微循环的右优势型冠脉生理模型。分别仿真单支狭窄、三支狭窄及微血管心绞痛等病理情况。建立EECP干预模型,结合上述病理模型,仿真EECP对病理模型的血流动力学作用。结果 建立的冠脉生理模型、病理模型及EECP干预模型仿真结果与相关文献中的实验数据相符合。EECP对3种病理情况都有改善冠脉血流的效果。对单支狭窄,EECP在左主干冠脉狭窄程度达到80%~85%之后便无法使血流恢复正常水平。对三支狭窄,若3条分支狭窄程度有1支超过90%,则无法使用EECP治疗。对微血管心绞痛,EECP有效的临界情况是充血心肌血流量>1.03 mL/（min·g）、冠状动脉血流储备>1.64。结论 建立的EECP干预冠脉血管病模型符合预期,所获仿真数据对EECP的临床操作具有一定参考价值。     

体外反搏中的血流分布与反搏方式的仿真研究

据报道体外反搏对身体各部位的缺血性疾病都有一定疗效。但由于受现有实验条件及检测手段的限制,对反搏参数的对症设置缺乏理论依据。为此,我们运用心血管系统的仿真模型,通过大量的仿真实验,对反搏过程中的血流分布进行分析研究,得到了针对不同部位缺血性疾病的理想反搏控制参量。仿真模型的输出结果与现有临床数据相吻合,说明了模型的可信性,同时也表明运用这一模型得到的结果有一定的实用价值。     

体外反搏对局部血管紧张素原与肾素基因表达的影响

目的探讨局部血管紧张素原(angiotensinogen,ATG)与肾素在增强型体外反搏(enhancedexternalcounterpulsation,EECP)治疗心肌缺血时的改变。方法利用冠状动脉结扎法造成犬急性心肌缺血动物模型。观察EECP治疗时缺血心肌、肾脏、肺脏和主动脉处肾素活性的改变。应用反转录-聚合酶链式反应(RT-PCR)观察组织中ATG与肾素mRNA的表达。结果反搏组缺血心肌肾素活性明显低于缺血组[(2.36±0.59)ng·ml-1·h-1对(3.21±0.67)ng·ml-1·h-1,P<0.05]。反搏组缺血心肌中ATG、肾素以及主动脉肾素mRNA也明显低于缺血组(0.56±0.16对0.71±0.15,1.12±0.16对1.37±0.22,P<0.05;0.96±0.11对1.18±0.18,P<0.05)。结论EECP能通过抑制心血管肾素mRNA的表达来抑制肾素活性,同时对ATGmRNA有抑制作用。这可能是EECP抑制心血管局部血管紧张素(Ang)Ⅱ水平,从而保护缺血心肌的机制之一。     

体外反搏走向世界

体外反搏是1963年美国哈佛大学的学者首先提出的一种辅助衰竭心脏的装置，但由于其设计上的缺陷，不能达到预期的疗效，在上世纪70年代末已被临床淘汰。     

红花多糖对荷瘤小鼠肿瘤组织血管生成的抑制作用研究

目的 观察红花多糖(SPS)对荷S180小鼠肿瘤组织血管生成的抑制作用.方法 按照SPS低剂量组20 mg/kg·d、SPS中剂量组40mg/kg·d、SPS高剂量组80 mg/kg·d的剂量对荷瘤小鼠进行腹腔注射给药,模型对照组给等体积的生理盐水,连续10天,第11天取瘤组织,免疫组化法检测肿瘤组织中血管内皮生长因子(VEGF)含量及微血管密度(MVD).结果 免疫组化法检测显示,SPS干预后小鼠肿瘤组织中VEGF灰度值上升:模型组(143.9±13.60)、SPS低剂量组(157.1±9.57)、SPS中剂量组(166.4±8.93)和SPS高剂量组(168.8±10.13);mVD明显下降:模型组(41.25±3.58)、SPS低剂量组(38.75±3.69)、SPS中剂量组(31.88±3.00),SPS高剂量组(25.38 ±4.21).结论 SPS能够通过抑制VEGF的表达、降低MVD,使肿瘤生长及转移受到抑制.     

冠心病介入治疗患者体外反搏的疗效探讨

目的探讨增强型体外反搏(enhancedexternalcouterpulsationEECP)对冠心病经皮冠状动脉介入治疗患者的疗效。方法经选择性冠状动脉造影确诊为冠心病且介入治疗成功的患者共469例,其中85例在药物治疗的基础上行体外反搏治疗(EECP组),另384例予单纯药物治疗(药物组)。临床随访6~72个月,部分行超声心动图和冠脉造影复查,比较两组随访病例临床终点事件、左室功能和造影结果的差异。结果(1)基线资料:对EECP组81例(95%)和药物组350例(91%)成功进行了随访,两组在临床资料、造影特征和介入治疗等方面差异均无统计学意义(P>0.05)。⑵临床终点事件:EECP组心绞痛复发率显著低于药物组(8·6%比17.4%,P<0.05);EECP组总的临床终点事件发生率明显低于药物组(18.5%比35.4%,P<0.01)。(3)超声心动图:两组基线室壁运动指数和左室射血分数相似,但复查时EECP组明显优于药物组(P<0.01)。⑷冠状动脉造影:两组再狭窄发生率差异无统计学意义P>0.05,但EECP组出现侧支循环患者数明显多于药物组(17.9%比5·1%,P<0.05),复查时病变血管参考内径[(3.29±0.61)mm比(3.06±0.50)mm,P<0.05]和支架内最小腔径[(3.02±0.59)mm比(2.67±0.62)mm,P<0.01]均显著大于药物组。结论对于介入治疗成功的冠心病患者,增强型体外反搏可减少心绞痛复发,改善预后和心功能,并可能有预防再狭窄的作用。     

Increased angiogenesis in chronic idiopathic myelofibrosis: vascular endothelial growth factor as a prominent angiogenic factor

Increased angiogenesis has been suggested to be implicated in the pathogenesis of chronic idiopathic myelofibrosis (CIMF). We hypothesized that vascular endothelial growth factor (VEGF) drives CIMF-associated angiogenesis, and thus, we aimed to determine its expression and biologic impact in newly diagnosed patients. All patients with CIMF diagnosed between 1990 and 2001, for whom adequate bone marrow specimens and clinical data were available, were deemed eligible. Each case was reclassified according to World Health Organization criteria. Microvessel density (MVD), as assessed by CD34 staining, and VEGF expression were examined by standard immunohistochemistry on paraffin-embedded trephine bone marrow biopsy specimens. The cytogenetic phenotype was determined by fluorescence in situ hybridization. Appropriate summary statistics were used for comparisons between groups; survival was calculated using Kaplan-Meier estimates. Parameters found to be of prognostic significance in univariate analysis were verified in a multivariate Cox regression model. Fifty-five patients with CIMF were investigated. With a median of 43 vascular lumina per 0.747 mm(2), patients with CIMF displayed significantly greater MVD than did age-matched controls (n = 10; median MVD, 19; P < .001) with equal distribution between the various fibrosis stages. Moreover, VEGF expression was significantly increased in CIMF (median, 12 cells/0.747 mm(2) versus 1.4 cells/0.747 mm(2); P = .01) and correlated with MVD (P = .001). However, neither MVD nor VEGF expression correlated with cytogenetics or clinical outcome. We conclude that in CIMF, increased MVD is detectable even in early (pre-)fibrotic stages. Moreover, we found significantly elevated VEGF expression correlating with MVD, thus suggesting VEGF to play a prominent angiogenic role and representing a novel potential therapeutic target in CIMF.     

姜黄素对佐剂性关节炎大鼠滑膜血管新生的影响

目的观察佐剂性关节炎大鼠血清血管内皮生长因子水平,滑膜血管新生和血管内皮生长因子及其受体的表达及姜黄素对其干预作用,探讨姜黄素治疗类风湿关节炎可能的机制。方法取sD大鼠,制成佐剂性关节炎模型,设正常组、模型组、姜黄素组、甲氨喋呤组。造模后第9天起分别予腹腔注射姜黄素50mg·kg^-1·d^-1,连续14d;甲氨蝶呤0．5mg·kg^-1·3d^-1,连续5次。计算第9天、第23天各组大鼠的AI积分。于第23天处死大鼠,ELISA法检测血清血管内皮生长因子;取膝关节滑膜,行免疫组化染色,观察滑膜微血管密度,半定量计算血管内皮生长因子及其受体的表达。结果①在第9天,各组造模后大鼠表现不同程度的关节炎症,其AI积分与正常组差异均有显著性（P〈0．01）。治疗后,第23天姜黄素组和甲氨蝶呤组大鼠AI积分与模型组相比有显著性差异（P〈0．01）;②模型组大鼠血清血管内皮生长因子明显升高（P〈0．01）,治疗后甲氨蝶呤组和姜黄素组的血清血管内皮生长因子与模型组相比差异均有显著性（P〈0．01）;③模型组大鼠滑膜微血管密度和血管内皮生长因子及其受体表达较正常组增加明显（P〈0．01）,治疗后甲氨蝶呤组和姜黄素组的微血管密度,血管内皮生长因子及其受体的表达与模型组相比差异均有显著性（P〈0．01）,且甲氨蝶呤组、姜黄素组组间比较差异无显著性（P〉0．05）。结论姜黄素能有效降低佐剂性关节炎大鼠血清血管内皮生长因子水平,抑制滑膜血管新生和血管内皮生长因子及其受体的表达,这可能是姜黄素治疗类风湿关节炎的作用机制之一。     

Inhibition of angiogenesis by NSAIDs: molecular mechanisms and clinical implications

Angiogenesis, the formation of new capillary blood vessels, is a fundamental process essential for reproduction and embryonic development. It is crucial to the healing of tissue injury because it provides essential oxygen and nutrients to the healing site. Angiogenesis is also required for cancer growth and progression since tumor growth requires an increased nutrient and oxygen supply. Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most widely used drugs worldwide for treating pain, arthritis, cardiovascular diseases, and more recently for colon cancer prevention. However, NSAIDs produce gastrointestinal ulcers and delay ulcer healing. Recently NSAIDs have been demonstrated to inhibit angiogenesis, but the underlying mechanisms are only beginning to be elucidated. The inhibition of angiogenesis by NSAIDs is a causal factor in the delay of ulcer healing, and it is becoming clear that this is also likely to be one of the mechanisms by which NSAIDs can reduce or prevent cancer growth. Based on the experimental data and the literature, the mechanisms by which NSAIDs inhibit angiogenesis appear to be multifactorial and likely include local changes in angiogenic growth factor expression, alteration in key regulators and mediators of vascular endothelial growth factor (VEGF), increased endothelial cell apoptosis, inhibition of endothelial cell migration, recruitment of inflammatory cells and platelets, and/or thromboxane A2 mediated effects. Some of these mechanisms include: inhibition of mitogen-activated protein (Erk2) kinase activity; suppression of cell cycle proteins; inhibition of early growth response (Egr-1) gene activation; interference with hypoxia inducible factor 1 and VEGF gene activation; increased production of the angiogenesis inhibitor, endostatin; inhibition of endothelial cell proliferation, migration, and spreading; and induction of endothelial apoptosis.     

体外反搏对血管剪切分力频率分量的影响

目的研究体外反搏治疗心肌缺血时血管对剪切应力各频率分量的影响。方法对17条开胸犬实时测节其正常情况下、缺血1h、缺血1h后反搏1h、反博2h以及正常情况时不同反搏压力下头臂干处的血流量，计算出此处剪切应力的频率分最变化。结果体外反搏使头臂干处剪切应力的频率分量发生了明显的变化。急性心肌缺血和体外反搏可以使剪切应力的各频率分量发生明显的改变。结论反搏压力大于一定程度时休外反搏可以明显改变体内血管剪切应力的低频分量。     

Hypoxia-induced expression of vascular endothelial growth factor by retinal glial cells promotes in vitro angiogenesis

To determine whether retinal glial cells (RGCs) participate in the paracrine regulation of retinal neovascularization, we investigated whether cultured RGCs synthesize and release vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) under normoxic or hypoxic conditions. Northern blot analysis demonstrated that cultured RGCs transcribed both VEGF mRNA with two molecular bands approximately 3.9 and 4.3 kilobases (kb), and bFGF mRNA with approximately 3.7 and 6.0 kb. The expression of VEGF mRNA was greatly enhanced by hypoxic cultivation (2% oxygen) when compared with normoxic cultivation (20% oxygen), while the expression of bFGF mRNA by RGCs was not significantly affected by hypoxia. The effects of RGCs-conditioned media (CM) on tritiated-thymidine incorporation and in vitro angiogenesis by retinal capillary endothelial cells (RECs) in producing the formation of capillary-like tubes in type I collagen gels, were evident in the observation that RGCs-CM harvested after hypoxic cultivation significantly enhanced tritiated-thymidine incorporation (1.9 times, P<0.01) and in vitro angiogenesis (2.4 times, P<0.01) compared with the normoxic RGCs-CM. These enhancing effects of RGCs-CM at hypoxia were suppressed by anti-VEGF neutralizing antibody. Furthermore, RECs were shown to express mRNA encoding the VEGF receptor flt-1 by northern blot analysis. These results suggest that VEGF expressed by RGCs under hypoxic conditions plays an integral role in the initiation and progression of retinal neovascularization in a paracrine manner.     

丰富环境对大鼠局灶性脑梗死后海马区微血管新生的影响

目的研究丰富环境对局灶性脑梗死后大鼠海马区微血管新生的影响。方法采用开颅电凝法制作SD大鼠右侧大脑中动脉缺血（MCAO）模型,术后24h随机分为丰富环境组（EE组）和标准环境组（SE组）。另设假手术组（Sham组）。免疫组织化学法检测大鼠缺血侧海马区血管内皮生长因子（VEGF）、Ⅷ因子表达,测定微血管密度。结果EE组和SE组大鼠缺血侧海马区术后1d VEGF开始表达,3d达高峰,EE组大鼠经干预后后期VEGF和微血管数目高于SE组大鼠。结论丰富环境可促进脑梗死大鼠海马区VEGF、Ⅵ因子表达,促进微血管新生,有利于脑损伤修复。     

血管生成的调节在瘢痕形成过程中的作用

血管生成的调节主要发生在创面愈合过程中的后2个阶段,即增生期、重塑期。正常情况下,创面形成大量排列紊乱的毛细血管床,但随着创面逐渐愈合,大部分血管凋亡、退化,并重新排列,最终恢复正常皮肤毛细血管结构与密度。该过程受一系列复杂分子及信号通路的调控,主要包括促血管生成和抗血管生成2方面因子的刺激,但关于创面血管功能和毛细血管增生如何影响瘢痕形成的关键问题仍未得到解答。本综述总结国内外现有研究成果,全面阐述创面血管生成的调控机制,深入探讨血管生成和瘢痕形成之间的关系以及血管异常生长影响瘢痕形成的潜在机制,介绍针对血管形成的相关治疗方案,为减少创面瘢痕形成提供新的思路。