血管内超声与64排螺旋CT分析冠状动脉斑块的对比研究

目的对冠状动脉病变患者进行血管内超声(IVUS)和64排螺旋CT(64MDCT)检查,评价两种检查手段在冠状动脉病变诊断中的应用价值。方法 24例临床怀疑或诊断为冠心病的患者接受冠状动脉64MDCT检查,并应用其工作站相关后处理技术对冠状动脉粥样斑块进行评估分析。一周内实施冠状动脉内IVUS检查,对冠状动脉病变进行定性和定量分析。结果分析病变血管52支,其中左主干24支,前降支21支,左回旋5支,右冠状动脉2支。IVUS显示有斑块病变的血管段为60段,64MDCT显示有斑块病变的血管样本57段,其中3段病变64MDCT诊断正常而IVUS显示为斑块早期病变。64MDCT对出现任何粥样硬化斑块节段诊断的敏感性为96%,特异性为94.7%。IVUS与64MDCT的管腔面积,外弹力膜面积、斑块面积的相关系数r分别为0.79、0.83、0.81。结论 IVUS能准确判断冠状动脉斑块的大小和性质。64MDCT作为非侵入性方法亦能显示管壁斑块的构成,判断病变的类型及程度,具有一定的敏感性和准确率。     

Blood Levels of Inflammatory and Destructive Biomarkers in Coronary Atherosclerosis of Different Severity

In male patients with coronary atherosclerosis without acute coronary syndrome, the levels of inflammatory-destructive biomarkers of atherosclerotic plaque instability depended on the severity and dissemination of coronary atherosclerosis. The highest levels of C-reactive protein and matrix metalloproteinase 3 were found in men with atherosclerotic involvement of all three main coronary arteries, primarily their middle and distal segments, and in men with predominance of low-grade stenoses (<50%) of coronary arteries in areas of atherosclerotic plaques.     

兔动脉粥样硬化易损斑块模型的建立

目的利用血管内超声(IVUS)的影像学特点分析建立的兔模型的易损斑块。方法16只雄性新西兰纯种兔,通过球囊损伤腹主动脉和高脂(1%胆固醇)饲料喂养8周,建立动脉粥样硬化易损斑块的兔模型。应用IVUS分别测量腹主动脉同一血管段中多个病变部位及其参考部位的各项指标,然后给予中国斑点蝰蛇毒(CRVV)和组胺药物触发,造成实验性斑块破裂和血栓形成。结果破裂与未破裂斑块相比较,破裂斑块具有较大的偏心性(P<0.05),破裂斑块呈现明显的正性重构,而未破裂斑块主要表现为负性重构。结论IVUS应用于已建立的动脉粥样硬化易损斑块的动物模型上,能够准确地识别动脉粥样硬化易损斑块,为以后实验性大样本研究药物稳定易损斑块的治疗奠定了基础。     

Monoclonality of smooth muscle cells in human atherosclerosis.

Atherosclerotic plaques contain a large monoclonal population of cells. Monoclonality could arise by somatic mutation, selection of a pre-existing lineage, or expansion of a pre-existing (developmental) clone. To determine the monoclonal cell type in plaque and learn when monoclonality arises, we studied X chromosome inactivation patterns using methylation of the X-linked human androgen receptor gene. Assays based on polymerase chain reaction were performed on samples of known cellular composition, microdissected from histological sections of human arteries. In atherosclerotic vessels, the majority of medial samples (7/11 coronary and 2/3 aortic) showed balanced (paternal and maternal) patterns of X inactivation, indicating polyclonality. In contrast, most samples of plaque smooth muscle cells showed a single pattern of X inactivation (3/4 aortic plaques and 9/11 coronary plaques; P < 0.01 versus media), indicating that plaque smooth muscle cells are monoclonal. Samples of plaque containing inflammatory or endothelial cells showed balanced X inactivation, also demonstrating polyclonality. Multiple plaques from a given patient showed no bias toward one allele, indicating there was no X-linked selection of cells during plaque growth. To determine whether plaques might arise from pre-existing clones (large X inactivation patches), we then studied 10 normal coronaries with diffuse intimal thickening. Six of the ten coronaries showed skewed X inactivation patterns in normal media and intima, suggesting the patch size in normal arteries is surprisingly large. Thus, smooth muscle cells constitute the monoclonal population in atherosclerotic plaques. The finding that normal arteries may have large X inactivation patches raises the possibility that plaque monoclonality may arise by expanding a pre-existing clone of cells rather than generating a new clone by mutation or selection.     

Photodynamic treatment for atherosclerotic plaques of the rabbit abdominal aorta by the laparoscopical approach using a pheophorbide derivative

A new photosensitizer, PH-1126, was administered intravenously into the ear veins of cholesterol-fed atherosclerotic rabbits at a dose of 1 mg/kg of body weight. At 24 hr after PH-1126 administration, the atherosclerotic abdominal aorta was irradiated with a krypton ion laser with a wavelength of 647 nm by 100 J/cm² by the laparoscopical approach. Twenty-four hours later, the abdominal aorta irradiated by the laser beam was excised for histological analysis. In the atherosclerotic plaques with photodynamic treatment, damaged foam cells were observed by scanning electron microscopy and transmission electron microscopy. Some of these cells were exposed to the aortic lumen. No significant changes were shown in the abdominal aorta either with plaques not injected with PH-1126 or without plaques after photodynamic treatment. These findings suggest that atherosclerotic plaques of the abdominal aorta could be selectively degraded by laparoscopical photodynamic treatment.     

Indocyanine green enables near-infrared fluorescence imaging of lipid-rich, inflamed atherosclerotic plaques

New high-resolution molecular and structural imaging strategies are needed to visualize high-risk plaques that are likely to cause acute myocardial infarction, because current diagnostic methods do not reliably identify at-risk subjects. Although molecular imaging agents are available for low-resolution detection of atherosclerosis in large arteries, a lack of imaging agents coupled to high-resolution modalities has limited molecular imaging of atherosclerosis in the smaller coronary arteries. Here, we have demonstrated that indocyanine green (ICG), a Food and Drug Administration-approved near-infrared fluorescence (NIRF)-emitting compound, targets atheromas within 20 min of injection and provides sufficient signal enhancement for in vivo detection of lipid-rich, inflamed, coronary-sized plaques in atherosclerotic rabbits. In vivo NIRF sensing was achieved with an intravascular wire in the aorta, a vessel of comparable caliber to human coronary arteries. Ex vivo fluorescence reflectance imaging showed high plaque target-to-background ratios in atheroma-bearing rabbits injected with ICG compared to atheroma-bearing rabbits injected with saline. In vitro studies using human macrophages established that ICG preferentially targets lipid-loaded macrophages. In an early clinical study of human atheroma specimens from four patients, we found that ICG colocalized with plaque macrophages and lipids. The atheroma-targeting capability of ICG has the potential to accelerate the clinical development of NIRF molecular imaging of high-risk plaques in humans.     

256层CT对颈动脉粥样硬化斑块成分及性质的分析

目的　探讨256层螺旋CT 血管造影（CT angiography,CTA）评价颈动脉粥样硬化斑块的价值。 方法　 对234例拟诊颈动脉硬化狭窄的患者行头颈部CTA检查, 根据颈动脉有无斑块分为病变组和正常对照组,通过CT值分析斑块成分和性质。 结果　病变组266支动脉,其中脂肪斑块组51支、纤维斑块组26支、钙化斑块组67支、混合斑块组122支;正常组163支。脂肪斑块组脑梗死出现率明显大于纤维斑块组和钙化斑块组（P＜0.01）;脂肪合并钙化斑块组脑梗死出现率明显大于纤维合并钙化斑块组（P＜0.01）;含脂肪斑块组溃疡出现率大于含纤维斑块组（P＜0.05）。 结论　256层螺旋CT能够分析颈动脉斑块的成分、性质,初步评价颈动脉斑块的稳定性。     

Non-invasive MRI of mouse models of atherosclerosis

Early detection and characterization of atherosclerotic lesions susceptible to sudden rupture and thrombosis may decrease morbidity and mortality. Plaque development has been extensively studied using MRI in animal models of rapidly progressing atherosclerosis. These transgenic mice develop atherosclerotic plaques in the aortic root by 10 weeks of age and throughout the vasculature thereafter. Transplantation of lesion-containing segments of the thoracic aorta into wild-type mice results in nearly total reversal of atherosclerosis, making it possible to study both progression and regression of plaques in this model. MRI permits the non-invasive accurate assessment of atherosclerotic plaque burden and the differentiation between the lipid and fibrous content of individual plaques, thus providing a non-invasive approach to serially monitor the evolution of individual plaques in the mouse models. Emergence of novel contrast agents that target a diverse set of molecules within the plaque are now helping to elucidate the changes at the cellular and molecular levels during plaque progression and regression.     

Morphometric and immunohistochemical characterization of the intimal layer throughout the arterial system of elderly humans

The purpose of the present study was to obtain insight into the natural development of adaptive intimal thickening and atherosclerosis in the arterial tree of human species. The morphometry and composition of the intimal layer were studied in the arterial system of elderly individuals. Post mortem, a total of 703 arterial segments were dissected from 24 subjects (age 81.9 ± 9.9 years). From each subject, segments were dissected from 31 different arteries. Area stenosis [(plaque area/vessel area) × 100%] was determined in each segment. By (immuno)histochemistry, lipid content and the presence of inflammatory cells (macrophages) were assessed in the coronary, common carotid, brachial, radial and internal iliac arteries. Adaptive intimal thickening or advanced atherosclerosis was observed in all studied artery types. Area stenosis was highest in the coronary arteries (median, 30%) and lowest in the arteries supplying the brain (median, ≤ 7%). Plaques hiding a lipid‐rich core and plaques with macrophage infiltration were observed in all five selected artery types. In summary, the present observation demonstrates that intimal thickening is a systemic process involving most artery types. Within elderly humans, features of advanced atherosclerotic disease, a lipid‐rich core and macrophages, can be observed in the intimal layer of artery types that are recognised for their relation with clinical syndroms as well as artery types that remain clinically silent.     

Laguerre-based method for analysis of time-resolved fluorescence data: application to in-vivo characterization and diagnosis of atherosclerotic lesions

We report the application of the Laguerre deconvolution technique (LDT) to the analysis of in-vivo time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) data and the diagnosis of atherosclerotic plaques. TR-LIFS measurements were obtained in vivo from normal and atherosclerotic aortas (eight rabbits, 73 areas), and subsequently analyzed using LDT. Spectral and time-resolved features were used to develop four classification algorithms: linear discriminant analysis (LDA), stepwise LDA (SLDA), principal component analysis (PCA), and artificial neural network (ANN). Accurate deconvolution of TR-LIFS in-vivo measurements from normal and atherosclerotic arteries was provided by LDT. The derived Laguerre expansion coefficients reflected changes in the arterial biochemical composition, and provided a means to discriminate lesions rich in macrophages with high sensitivity (>85%) and specificity (>95%). Classification algorithms (SLDA and PCA) using a selected number of features with maximum discriminating power provided the best performance. This study demonstrates the potential of the LDT for in-vivo tissue diagnosis, and specifically for the detection of macrophages infiltration in atherosclerotic lesions, a key marker of plaque vulnerability.     

慢病毒介导的SHP-1过表达抑制模型小鼠动脉粥样硬化

目的:研究含SH2结构域的酪氨酸磷酸酶-1(SHP-1)慢病毒载体在动脉粥样硬化模型小鼠中的作用。方法:将45只8周龄雄性Apo E基因敲除小鼠随机分为3组,即对照组、绿色荧光蛋白(GFP)转染组、SHP-1转染组。3组小鼠右侧颈总动脉植入套环并高脂喂养8周,随后分别转染GFP空载体和SHP-1慢病毒(SHP-1-LV)。分别于转染第1、2、6周检测硬化斑块荧光强度、小鼠体重、血清总胆固醇(TC)、甘油三酯(TG)水平变化,并利用real-time PCR和Western blot检测右侧颈总动脉中SHP-1、白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、基质金属蛋白酶(MMP)-2、MMP-9等的表达,最后制作切片染色观察斑块病理变化。结果:荧光显微镜下观察到慢病毒转染第1、2、6周后斑块有明显荧光,且在第2周时荧光强度最高,SHP-1慢病毒转染对小鼠体重和血清TC、TG水平无显著影响,但可显著上调右侧颈总动脉中SHP-1的mRNA和蛋白的表达,同时抑制IL-6、TNF-α、MMP-2、MMP-9等的表达水平。SHP-1慢病毒转染也降低右侧颈总动脉斑块面积比及脂质含量。结论:过表达SHP-1可能促进小鼠动脉粥样硬化斑块消退,从而为预防和治疗动脉粥样硬化提供靶点。     

Intimal plaque development and oxidative stress in cholesterol‐induced atherosclerosis in New Zealand rabbits

Although oxidative stress is well known in atherogenesis, the origin, nature and kinetics of free radicals involved have not been well described till now. Here, we correlated parameters of oxidative stress with cellular components during induction and stabilization of aortic intimal lesions which were induced in rabbits by feeding a cholesterol‐enriched diet for 6 weeks and a normal diet for further 68 weeks. Plasma lipids, aortic plaque size and composition (macrophages, smooth muscle cells, oxidized LDL by morphometry), as well as aortic radical production (by luminol‐enhanced chemiluminescence and TEMPO‐9AC fluorescence) were measured after various time points. The parameters of oxidative stress were correlated with the different cellular components of the aortic plaques. The plaques increased until week 21, no significant regression was found until week 74, plasma cholesterol was maximal at week 6. Macrophages, oxidized LDL and generation of different species of free radicals were increased during plaque development, yet with different time kinetics. Whereas chemiluminescence correlated only weakly with the amount of intimal macrophages, strong correlations were found between TEMPO fluorescence and smooth muscle cells (r = 0.4778, P < 0.001) and between macrophages and oxidized LDL (r = 0.5896, P < 0.0001). Different indicators of oxidative stress were increased during plaque progression and stabilization. However, the various correlations show, that distinct types of reactive species secreted probably from macrophages and smooth muscle cells contribute to oxidative stress in the different phases of plaque development.     

消斑肽加速氧化低密度脂蛋白诱导的血管平滑肌细胞凋亡

目的：我们已经发现消斑肽能逆转平滑肌源性的泡沫细胞,阻抑C57BL/6J小鼠动脉粥样硬化斑块的形成,对已形成的斑块有消退作用。本文主要探讨消斑肽的作用机制。方法：体外培养的猪主动脉平滑肌细胞,先与15 mg/L的氧化低密度脂蛋白孵育72 h,再与0.1 mg/L消斑肽孵育24 h,应用荧光染色技术、激光共聚焦显微技术和流式细胞术,观察消斑肽对平滑肌细胞的作用。结果：氧化低密度脂蛋白能诱导血管平滑肌细胞发生凋亡;消斑肽能加速氧化低密度脂蛋白诱导的细胞凋亡。结论：综合以前的实验,消斑肽可能是通过加速斑块中细胞的凋亡发挥抗动脉粥样硬化效果。     

The distribution of adhesion molecules in human atherosclerosis

Chronic inflammatory cells are a recognized component of atherosclerotic plaques at all stages of development. As adhesion molecules play a fundamental role in inflammatory processes, we have carried out an immunohistochemical investigation of the distribution of endothelial leucocyte adhesion molecule-1 (ELAM-1)*, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in human atherosclerotic lesions. Autopsy specimens from abdominal aorta and coronary arteries were obtained from 21 cases within 24 h of death. ELAM-1 and ICAM-1 were consistently expressed by the entire intimal endothelium of normal coronary arteries and also by the intimal endothelium overlying aortic fatty streaks. Both coronary artery and aortic lesions showed strong staining for ICAM-1 on and around macrophages. VCAM-1 was not detected on intimal endothelial cells, but strong staining of adventitial lymphoid aggregates for this molecule was seen. This work suggests a role for ELAM-1 and ICAM-1 in mononuclear cell recruitment during atherogenesis.     

Chronic exposure to the carcinogenic compound benzo[a]pyrene induces larger and phenotypically different atherosclerotic plaques in ApoE-knockout mice

Benzo[a]pyrene (B[a]P) is a polycyclic aromatic hydrocarbon with atherogenic and carcinogenic properties. The role of B[a]P in carcinogenesis is well established, and thought to exert via enzymatic activation into reactive metabolites that are capable of binding to the DNA leading to uncontrolled proliferation. However, the mechanism underlying the atherogenic properties of B[a]P is still unclear. Therefore, the effects of chronic B[a]P exposure on atherosclerotic plaque development in apolipoprotein E knockout (apoE-KO) mice were studied. ApoE-KO mice were orally treated with 5 mg/kg/bw B[a]P once per week for 12 or 24 consecutive weeks. Levels of reactive B[a]P metabolites in the arterial tree (from the aortic arch until the iliac artery bifurcations) were high as shown by the level of B[a]P DNA-binding products measured in DNA isolated from the entire aorta (38.9 +/- 4.8 adducts/10(8) nucleotides). Analysis of atherosclerotic lesions in the aortic arch showed no influence of B[a]P on location or number of lesions. Moreover, no increased levels of p53 nuclear protein accumulation or cell proliferation, as detected by immunohistochemistry, were seen in the plaques of the B[a]P-exposed animals. However, the effects of B[a]P on advanced lesions were obvious: advanced plaques were larger and more prone to lipid core development and plaque layering at both 12 and 24 weeks (P < 0.05). In the B[a]P-exposed animals advanced plaques contained more T-lymphocytes and macrophages than in the control animals at both end points (P < 0.05). These data suggest that B[a]P does not initiate atherosclerosis in apoE-KO mice, but accelerates the progression of atherosclerotic plaques via a local inflammatory response.     

Lipids in cells of atherosclerotic and uninvolved human aorta. II. Lipid metabolism in primary culture

[3H]Acetate and [3H]oleate were used to evaluate the rate of lipid synthesis in smooth muscle cells of human aorta. Experiments were carried out in primary cultures derived from the intima and media of unaffected and atherosclerotic vascular segments. The obtained results indicate that the rate of lipid synthesis in cells cultured from fatty streaks, atherosclerotic plaques, and underlying media is higher than in cells cultured from an uninvolved intima and media, respectively. The highest level of the label incorporation was observed in the fraction of phospholipids. In cultures obtained from fatty streaks and plaques, an increased incorporation of the labeled precursors into phospholipids, triglycerides, free sterols, and sterol esters was registered. The highest relative increase occurred in the fraction of sterol esters, the rate of acetate inclusion being five- to sixfold higher compared to the cell cultures derived from unaffected aortic segments. A direct and very close correlation was found between the rate of lipid synthesis and lipid levels in cells of normal and atherosclerotic aorta. The role of intracellular lipid metabolism disorders in the accumulation of excessive fat by "atherosclerotic" cells is discussed in this report.     

Anatomical Variations in the Aortic Bifurcation in New Zealand White Rabbits on Arteriography

The radiologic anatomy of the aortic bifurcation in the rabbit has received little study but it is important as this anatomical area is widely used in atherosclerosis research. Thirty rabbits were used to study the aortic bifurcation and subsequent branching patterns on arteriography. Fifteen different arteries were identified. Mean arterial diameters of 2.88 ± 0.7 and 2.27 ± 0.55 mm were obtained for the aorta and external iliac arteries, respectively. The cranial and middle aspects at the seventh lumbar vertebra (L7) were the most frequent anatomical landmarks (53.3% of the cases) for aortic and common iliac bifurcations, respectively. The caudal aspect of L6 was the most frequent origin (50% of the cases) for the median sacral artery. Deep circumflex iliac arteries originated from common iliac arteries and not the abdominal aorta in the rabbit, showing anatomical asymmetry in 73.3% of the cases. No gender disparity was found in the anatomical location of any of the arteries of the study. Knowledge of normal vascular landmarks for the aortic bifurcation as well as anatomical variations should be helpful to future experimental studies. Anat Rec, 297:663–669, 2014. © 2014 Wiley Periodicals, Inc.     

Type I collagen gene expression in human atherosclerosis. Localization to specific plaque regions.

Because collagen is a major component of the human atherosclerotic plaque, factors controlling collagen synthesis may have a profound influence on the volume growth of these intimal lesions. In human arteries, we compared normal vs atherosclerotic media vs intimas for type I collagen gene expression using immunocytochemistry and in situ messenger RNA hybridization with subsequent correlations with plaque topographical features. We also determined the associations of such collagen gene expression with proximity to monocyte/macrophages and T lymphocytes. Type I collagen synthesis appears to be upregulated in atherosclerotic plaques compared with their underlying medias and normal internal mammary arteries and coronary diffuse intimal thickenings. At least in established and advanced coronary and carotid plaques, type I collagen gene expression is focal and especially prevalent in fibrous cap and vascularized regions. Although macrophages and type I procollagen messenger RNA and protein are both found in atherosclerotic plaques, no apparent spatial correlation between macrophage presence and type I procollagen presence was found within these atherosclerotic intimas. Type I procollagen presence appears to be negatively associated with the spatial presence of T cells. Thus, human atherosclerotic plaques exhibit nonuniform patterns of type I collagen gene expression. Although the biochemical determinants of this focal gene expression have yet to be determined, it is conceivable that stimulatory/inhibitory cytokines and other factors (eg hemodynamics) play important roles in determining the focal nature of collagen synthesis in atherosclerosis.     

采用高脂饲料加空气干燥术建立颈动脉粥样硬化动物模型

目的:利用高脂饮食加空气干燥术建立一种稳定、重复性好、有较典型动脉粥样硬化病理改变的动物模型。方法:32只日本大耳白兔随机分为模型组(n=24)、对照组(n=8)。模型组给予高脂饲料喂养加空气干燥术,术中结扎左侧颈动脉分支血管,对照组正常饲料喂养,分别于术后第2、4、8、12周处死动物。取颈动脉组织切片HE染色,光镜下观察。结果:(1)75%兔颈总动脉存在细小血管分支,暂时结扎侧支血管后干燥效果更好。(2)对双侧颈动脉实施手术,结扎左侧分支,成模率更高。部分斑块显示出不稳定性。结论:采用改进后高脂饮食加空气干燥术可成功建立兔颈动脉粥样硬化模型,其病理特点适合于目前临床研究。     

细胞外基质金属蛋白酶诱导因子与尿激酶型纤溶酶原激活物在载脂蛋白E 敲除大鼠动脉粥样硬化斑块表达的意义及相关性*

目的：探究细胞外基质金属蛋白酶诱导因子（ EMMPRIN）与尿激酶型纤溶酶原激活物（ μPA）在载脂蛋 白E 基因（ ApoE）敲除大鼠动脉粥样硬化斑块表达意义及相关性。方法：选择ApoE 敲除大鼠,将其分为对照组 与高脂饮食组,对照组大鼠实施正常饮食喂养,高脂饮食组实施高脂饮食喂养,并分别于喂养的第6、10、14、 18 周处死部分大鼠,采用H-E 染色观测动脉粥样硬化斑块形态, 免疫印迹及RT-PCR 检测主动脉粥样硬化斑块内 EMMPRIN和μPA 的表达及其mRNA表达,并实施组间比较。结果：高脂饮食组大鼠动脉出现明显动脉粥样硬化 斑块,且随着时间的推进,逐渐加重,而对照组大鼠并未出现明显的动脉粥样硬化斑块;喂养第6、10、14、18 周时高脂饮食组大鼠主动脉内EMMPRIN和μPA 的表达及其mRNA表达均明显高于对照组;EMMPRIN与μPA 表 达呈正相关。结论： EMMPRIN与μPA 在动脉粥样斑块中的表达水平呈正相关关系,两者可能参与动脉粥样硬化 斑块的形成并发挥促进作用。