反义c-myc寡脱氧核苷酸对家兔髂总动脉损伤后内膜增生的影响

目的：观察反义c-myc寡脱氧核苷酸(ASODN)对家兔髂总动脉损伤后内膜增生的影响，探讨其防治再狭窄的潜在作用。方法：通过pluronic gel缓释系统和Lipofeclin转染导入系统，将c-myc ASODN作用于家兔髂总动脉损伤后的血管外膜，3周后对所取的血管节段进行组织切片和苏木精-伊红染色，在显微镜下进行形态学观察，并采用图像分析系统进行图像分析，计算出内膜，中膜(I/M)面积比和I／M厚度比，并进行统计学处理。结果：c-myc ASODN可明显抑制内膜增生，而正义c-myc ODN对内膜增生无影响。结论：c-myc ASODN以序列特异性方式抑制了新生内膜的形成。     

Longitudinally orientated smooth muscle cells in rabbit arteries

Intima formation in vessels, spontaneous or experimentally induced, is generally characterized by the presence of longitudinally orientated smooth muscle cells (LSMC). During an experiment of neo-intima induction in carotid arteries in rabbits, by application of a nonconstrictive silastic cuff, a study was performed to investigate the presence of LSMC in the systemic and pulmonary circulations, in both elastic and muscular arteries. Three patterns could be distinguished: intimai cushions in muscular arteries, single or small groups of LSMC in the intima in elastic and larger muscular arteries, and intra-medially located layers or columns of LSMC in the aorta, the pulmonary artery, at the bifurcation of the aorta and around orifices of branches. In order to understand this peculiar orientation a biomechanical approach was used: this showed that near the lumen the circumferential stress is 4.5 times higher than the longitudinal. Because the cell surface of the smooth muscle cells exposed to this stress per unit vessel length is much less in the longitudinal than in the circular direction we conclude that the LSMC align in the direction which allows them to cope most effectively with the mechanical stresses.     

睾酮对雄性家兔血管损伤后内皮功能及内膜增生的影响

目的:探讨睾酮对雄性家兔腹主动脉球囊损伤后内皮功能及内膜增生的影响。方法:选择健康雄性新西兰白兔24只随机分成3组:对照组(假去势)、低睾酮血症组(去势)及睾酮替代组(去势1周后加用长效十一酸睾酮单次肌注,14mg/kg),每组8只。去势10d后对所有动物行腹主动脉球囊损伤术。损伤后两周测血浆睾酮、血脂、一氧化氮代谢产物(NO₂^-/NO₃^-)、超氧化物歧化酶(SOD)及丙二醛(MDA)水平,并截取腹主动脉进行图像分析。结果:睾酮替代组和对照组的血浆总胆固醇、甘油三酯、低密度脂蛋白及MDA水平和新生内膜面积明显低于低睾酮血症组(P＜0.01或P＜0.05),睾酮替代组和对照组的NO₂^-/NO₃^-及对照组的SOD水平高于低睾酮血症组(P均＜0.05),替代组和对照组两组间比较各数据无差异。结论:生理水平的睾酮(内源性或外源性替代)具有保护雄性家兔血管内皮,抑制动脉损伤后内膜增生的作用。     

Expression of cell cycle regulators during smooth muscle cell proliferation after balloon catheter injury of rat artery

Intimal hyperplasia is defined as the abnormal migration and proliferation of vascular smooth muscle cells (VSMCs) with deposition of extracellular matrix. However, the cell cycle regulatory mechanisms of injury-induced VSMC proliferation are largely unknown. To examine the expression kinetics of cell cycle regulatory factors which is known to be worked positively or negatively, we used rat balloon injury model. Marked induction of proliferating cell nuclear antigen (PCNA), G1/S cyclin-dependent kinase (cdk2), and its regulatory subunit (cyclin E) occurred between 1 and 3 days after balloon arterial injury, and this was sustained for up to 7 days and then declined. However, the induction of the negative regulators, p21 and p27, occurred between 3 and 5 days of injury, peaked after 7 and 14 days and was then sustained. VSMC proliferation after balloon catheter injury of the rat iliac artery is associated with coordinated expression of positive (cdk2, cyclin E and PCNA) and negative (p21, p27) regulators. Cell cycle regulators such as cdk2, cyclin E, p21, p27 may be suitable targets for the control of intimal hyperplasia.     

血管腔内平整化治疗对动脉内膜剥脱术后内膜增生的影响及其机制

目的探讨血管腔内平整化治疗(IPT)对内膜剥脱术后内膜增生的作用及其可能机制,为临床运用提供理论依据。方法用金钢砂磨针磨除内膜的方法建立颈动脉内膜剥脱模型。用随机数表法将新西兰兔随机分成两组(Ⅰ组比Ⅱ组),每组8只。Ⅰ组为颈动脉内膜剥脱模型对照组;Ⅱ组为采用金刚砂磨针磨除内膜后,行IPT;取对侧颈动脉作为自身对照。术后即刻及2周应用超声诊断仪评价血管狭窄程度。2周后,取两侧颈动脉标本行苏木精-伊红(HE)染色、Masson染色,评价内膜增生情况。采用t检验进行两组间比较,多组间比较采用单因素方差分析。结果2周后,Ⅱ组腔管比(内腔面积/总面积)低于Ⅰ组[(40.57±2.40)%比(52.79±2.01)%,t=8.387,P<0.01],新生内膜区Ⅰ型胶原蛋白表达低于Ⅰ组(0.134±0.020比0.110±0.011,t=2.621,P<0.05),血管平均血流速度低于Ⅰ组[(111.300±21.380)cm/s比(168.700±13.640)cm/s,t=4.222,P<0.01],管腔直径高于Ⅰ组(0.852±0.152)mm比(1.167±0.213)mm,t=2.529,P<0.05),差异均有统计学意义。结论IPT能够抑制动脉内膜剥脱术后内膜增生,可能与血小板黏附减少有关。     

COX基因多态性与缺血性卒中的相关性研究

【摘要】 目的 探讨环氧合酶(COX)代谢通路基因多态性及其与缺血性卒中发病率的关系。方法 将2013年2月~2015年11月在德阳市人民医院和温州医科大学第三附属医院神经内科住院经头颅CT和MRI检查确诊的299例急性缺血性卒中患者,根据彩超结果分为颈动脉易损斑块组（VP）94例、稳定斑块组（SP）74例和无斑块组（NP）131例;同时再分为颈动脉内膜增厚组（IT）108例和非内膜增厚组（NT）191例。使用聚合酶链反应和质谱分析测定基因多态性,包括前列腺素合酶1(PTGS1 rs1236913)、前列腺素H合酶2(PTGS2 rs689466)、血栓素A2合酶(TBXAS1 rs2267679、rs41708、rs194149)、前列腺素E合酶(PTGES2 rs6478818)、环前列腺素合成酶(PTGIS rs5602、rs5629)。结果 在易损斑块组和无斑块组之间TBXAS1 rs194149 GG基因型(P=00281),PTGIS rs5602 CT基因型(P=00319)存在显著差异。内膜增厚组和非内膜增厚组之间PTGS2 rs689466 GG基因型(P=00216)显示显著差异。多元回归分析显示,PTGIS的AA基因型(P=00308,OR:0275,95%CI:0079～0955)和PTGS2的AG+ GG基因型(P=00065,OR:2162,95%CI:1232～3795)是内膜增厚的破坏性因素。结论 COX的单核苷酸多态性(SNP)与脑梗死的发病率存在相关性,PTGIS和PTGS2基因多态性与内膜增厚脑卒中患者相关。     

Mean HbA1c over 18 years predicts carotid intima media thickness in women with type 1 diabetes

Aims/hypothesis Intima media thickness (IMT) of the common carotid artery (CCA) is a validated surrogate marker of early atherosclerosis. The aim of our study was to assess the association between IMT in CCA and long-term mean HbA₁c in type 1 diabetes. We also elucidated the association between carotid IMT and preclinical coronary atherosclerosis.Methods In 39 individuals with type 1 diabetes, HbA₁c was measured prospectively over 18 years. The IMT examinations were performed with high-resolution ultrasound. The association between carotid IMT and preclinical coronary atherosclerosis (assessed by intravascular ultrasound [IVUS]) was tested in 29 of the patients.Results Mean HbA₁c over 18 years was 8.2% (range: 6.6–11.3%). Mean age at follow-up after 18 years was 43 years and mean duration of diabetes was 30 years. IMT was significantly higher in diabetic patients than in an age- and sex-matched reference population. The IMT values were at the same level as for controls who were 20 years older. In women, HbA₁c was significantly associated with mean average CCA IMT (r²=0.77, p<0.0001 when adjusted for age), whereas there was no significant association for men. Among women, a significant association was also found between carotid IMT and the percentage of coronary vessel area stenosis (r=0.65, p=0.03).Conclusions/interpretation The present findings suggest an important role of long-term hyperglycaemia in the development of atherosclerosis, especially in women with type 1 diabetes.Type 1 diabetes patients have earlier development of, and more advanced, atherosclerosis compared with an age- and sex-matched reference population. In women, carotid IMT reflects preclinical coronary atherosclerosis.     

老年人脉压指数与颈动脉内膜中层厚度的关系

为了研究脉压指数与颈动脉内膜中层厚度的关系 ,对 334例老年人行颈动脉内膜中层厚度超声检测并进行测压 ,分别以脉压≤ 6 0mmHg、6 1～ 80mmHg、81～ 10 0mmHg及 >10 0mmHg和脉压指数≤ 0 .4 0 0、0 .4 0 1～ 0 .5 0 0、0 .5 0 1～ 0 .6 0 0及 >0 .6 0 0分为四个亚组进行分析。结果发现 ,随着脉压和脉压指数的增加 ,颈动脉内膜中层厚度和收缩压均随之增加 ,脉压指数组舒张压进行性下降 ;Spearman’s相关分析发现 ,颈动脉内膜中层厚度与脉压指数相关性最佳 ;多元逐步回归分析显示 ,颈动脉内膜中层厚度仅与脉压指数、年龄具有显著回归效果 ,脉压指数的标准回归系数远大于年龄。结果提示 ,在老年人中脉压指数评价血管硬化比脉压有一定的优越性