Localization patterns of plasma apolipoproteins in human atherosclerotic lesions.

The localization patterns of human plasma lipoproteins and their respective apoproteins and of neutral lipid were determined in normal and atherosclerotic arteries. Specific antisera were prepared against plasma low-density lipoproteins(LDL) and their apoproteins (apoB), high-density lipoproteins(HDL) and one of their major apoproteins (apoA-I1, and apoC-III, which is a major apoprotein of very low-density lipoproteins (VLDL). Using immunofluorescence techniques, the various antigens were localized in arterial samples obtained at surgery or autopsy. The three apoproteins and neutral lipid were localized to the same tissue areas, namely, lipid core regions and certain connective tissue of atherosclerotic lesions, in 61% of the fibrous plaques and 48% of the fatty streaks examined. In marked contrast, none of the uninvolved arterial regions showed the presence of all four factors together. As controls, the localization of other serum proteins was also determined in these arteries using immunofluorescence techniques. Fibrinogen was associated with regions of maximum complementary localization of factors in 37% of the fibrous plaques and 64% of the fatty streaks. However, albumin was found in only 4-5% of these same regions. The present results suggest that not only LDL but also HDL and VLDL or their respective apoproteins as well as fibrinogen are specifically retained by certain tissue components of the atherosclerotic lesion.     

Detection of early atherosclerotic lesions in the carotid artery: Experimental and preliminary human data

There is a strong need to directly image, noninvasively, atheromatous lesions for early lesion detection, serial assessment of the presence and extent of disease, and treatment monitoring of atherosclerosis. The aim of this study was to investigate the value of polyclonal¹¹¹Inhuman IgG (¹¹¹In-HIG) in human carotid artery disease. A comparative study between¹¹¹In-HIG and¹²⁵I-LDL uptake in atheromatous lesions was also performed in 12 cholesterol-fed New Zealand white rabbits. Ultrasonographic and scintigraphic findings in 58 patients were compared. HIG was labeled with 500 µCi¹¹¹Indium by the diethyleneaminepentaacetic anhydride (DTPA). After injection of 10 µCi¹²⁵I-LDL, the respective entry into aortic segments was evaluated in the animals.¹¹¹In-HIG accumulation was higher in reendothelialized areas, foam cells, at the edge of lesions, and in hyperlipidemic rabbits. Ultrasound examinations of the carotid arterial wall showed wall thickening in 45 patients and plaques in 44 patients. Scintigraphic imaging of the identical area provided increased uptake in 40 patients and no abnormal uptake of¹¹¹In-HIG in 18 patients. There was, however, no significant correlation between the radiotracer retention and the ultrasonographic findings or laboratory and clinical parameters. The data provide evidence that the two imaging techniques for early atherosclerotic lesions are visualizing different aspects of atherogenesis: the functional (HIG) on the one side, and the morphological (ultrasonography) on the other side.     

Mitogenic activity in human atherosclerotic lesions

Focal smooth muscle cell proliferation is a key event in atherogenesis, but the stimulating factors are unknown, and there is little information on the occurrence of growth promoting factors in the arterial wall. We have tested extracts of human aortic intima for stimulation of DNA synthesis, using the chick chorioallantoic membrane (CAM) assay in an attempt to avoid artifacts arising with cultured cells. Consistently high levels of stimulation were obtained with early proliferative (gelatinous) lesions (mean DNA synthesis 188% of control, n = 6) and slightly more advanced transitional lesions (mean 160%, n = 4); results with mature fibrous plaques were variable (range 120-182%, n = 3). Significant stimulation was also given by four of eleven samples of apparently lesion-free intima. Intima contains fibrinogen and a range of fibrinogen and fibrin degradation products (FRA) and preliminary fractionation experiments suggest that activity may reside in the FRA fraction. Serum does not stimulate DNA synthesis in the CAM; extract activity was retained in FRA-containing fractions after removal of most serum proteins by affinity chromatography, but was mainly lost from serum protein-containing fractions after removal of FRA.     

Neovascularization in human coronary atherosclerotic lesions

Neovessels within human coronary atherosclerotic lesions are fequently observed, but their pathophysiological significance is still subject to debate. Also, the origin of these vessels and their pathways in the arterial wall are not well-known. In this study, we describe the transmural pathway and the frequency of neovessels both in vivo and in autopsy cases. Atherosclerotic coronary arteries were obtained during autopsy in 10 subjects without previous cardiovascular symptoms. In 25 patients undergoing percutaneous intervention for either stable or unstable angina, plaque fragments were retrieved by directional coronary atherectomy. In the autopsy study, at least one coronary artery in each case showed some degree of neointimal proliferation, characterized by smooth muscle cells in a dense extracellular matrix. A neovascularization process was seen in 17.5% of the 40 samples analyzed. In 2 cases, the transmural pathway of the neovessels could be tracked: serial sections revealed the emergence of an arteriole from the adventitia of the coronary artery, its transmedial course as a capillary, and its opening into the coronary arterial lumen. In symptomatic patients who underwent atherectomy, neovessels were found in 1 of 9 patients with stable angina (11%), and in 8 of 16 patients with unstable angina (50%, P < 0.05). Mostly, the neovessels appeared as capillaries cut in their short axis. In 2 cases, however, the capillary was seen in its longitudinal axis, and its pathway could be traced through the atherosclerotic lesion to its opening in the coronary lumen, as in the autopsy study. Therefore, neovessels frequently develop in the atherothrombotic plaque, both in asymptomatic and anginal patients. In the latter group, the proliferation of neovessels is more frequent in acute coronary syndromes. These findings have several implications, in particular for percutaneous coronary angioplasty and related procedures, such as local drug delivery. © 1996 Wiley-Liss, Inc.     

Immunoglobulin in atherosclerotic lesions of human aorta

An augmented expression of mRNA for IgG light chain was demonstrated age-dependently on atheromatous lesions of the aorta in Watanabe heritable hyperlipidemic (WHHL) rabbits. The present study was designed to determine factors related to inflammation in human vessels excised during surgery. We detected IgG mRNAs using RT-PCR in human atherosclerotic lesions but not in human umbilical arteries which have no atheromatous lesions. To determine the clonality of IgGs, cDNAs encoding variable regions of IgG heavy chain were examined using RT-PCR. Atherosclerotic lesions had several subtypes of IgG gene families' suggesting the involvement of polyclonal B-cells. mRNAs of interleukins-6 (IL-6), -1alpha (IL-1alpha), and -1beta (IL-1beta) were also detected in the same samples. In summary, inflammatory reactions were present in the atherosclerosis lesion.     

Anatomic-ultrasound correlations for intraoperative open chest imaging of coronary artery atherosclerotic lesions in human beings

This study was performed to further validate a method for intraoperative ultrasound imaging of coronary arteries. Ultrasound images of coronary atherosclerotic lesions were compared with anatomic specimens of the coronary arteries obtained from open chest human subjects. The anatomic specimens were derived from four cardiac transplant recipients, accepted as candidates for transplantation because they had severe diffuse atherosclerotic disease, and one patient who died in the early postoperative period after a coronary artery bypass procedure. Twenty-six ultrasonically imaged atherosclerotic areas of the coronary arteries in these patients were compared with formalin-fixed and decalcified anatomic specimens. Specific ultrasound appearances for atherosclerotic lesions were observed, including 1) discrete (focal) stenosing fibrous/atheromatous plaques; 2) diffuse nonobstructive fibrous/atheromatous disease (detectable even in anatomically small vessels); 3) complete occlusion by fibrous/atheromatous lesions or organizing thrombus; and 4) "shadowing," an ultrasound pattern characteristic of significant calcification within atherosclerotic plaques. As part of this study, a new 12 MHz water path probe was evaluated for coronary artery scanning. The new probe allowed improved access to coronary arteries and increased detail of anatomic visualization. Both the performance of the new high resolution probe and the knowledge gained by the anatomic correlations obtained in this study should aid the development of intraoperative coronary artery scanning for surgical localization of atherosclerotic disease during coronary bypass surgery.     

Vitamin E oxidation in human atherosclerotic lesions

Oxidation of low-density lipoproteins (LDL) is a key process in atherogenesis, and vitamin E (alpha-tocopherol, TOH) has received attention for its potential to attenuate the disease. Despite this, the type and extent of TOH oxidation and its relationship to lipid oxidation in the vessel wall where lesions develop remain unknown. Therefore, we measured oxidized lipids, TOH, and its oxidation products, alpha-tocopherylquinone (TQ), 2,3- and 5,6-epoxy-alpha-tocopherylquinones by gas chromatography-mass spectrometry analysis in human lesions representing different stages of atherosclerosis. We also oxidized LDL in vitro to establish "footprints" of TOH oxidation product for different oxidants. The in vitro studies demonstrated that tocopherylquinone epoxides are the major products when LDL is exposed to the one-electron (ie, radical) oxidants, peroxyl radicals, and copper ions, whereas TQ preferentially accumulates with the two-electron (nonradical) oxidants, hypochlorite, and peroxynitrite. In human lesions, the relative extent of TOH oxidation was maximal early in the disease where it exceeded lipid oxidation. Independent of the disease stage, TQ was always the major oxidation product with all products together representing <20% of the total TOH present, and the oxidation product profile mirroring that formed during LDL oxidation by activated monocytes in the presence of nitrite. In contrast, oxidized lipid increased with increasing disease severity. These results suggest that two-electron oxidants are primarily responsible for TOH oxidation in the artery wall, and that the extent of TOH oxidation is limited yet substantial lipid oxidation takes place. This study may have important implications regarding antioxidant supplements aimed at preventing LDL oxidation and hence atherogenesis.     

Advanced atherosclerotic lesions in the innominate artery of the ApoE knockout mouse

Most previous studies of atherosclerosis in hyperlipidemic mouse models have focused their investigations on lesions within the aorta or aortic sinus in young animals. None of these studies has demonstrated clinically significant advanced lesions. We previously mapped the distribution of lesions throughout the arterial tree of apolipoprotein E knockout (apoE(-/-)) mice between the ages of 24 and 60 weeks. We found that the innominate artery, a small vessel connecting the aortic arch to the right subclavian and right carotid artery, exhibits a highly consistent rate of lesion progression and develops a narrowed vessel characterized by atrophic media and perivascular inflammation. The present study reports the characteristics of advanced lesions in the innominate artery of apoE(-/-) mice aged 42 to 60 weeks. In animals aged 42 to 54 weeks, there is a very high frequency of intraplaque hemorrhage and a fibrotic conversion of necrotic zones accompanied by loss of the fibrous cap. By 60 weeks of age, the lesions are characterized by the presence of collagen-rich fibrofatty nodules often flanked by lateral xanthomas. The processes underlying these changes in the innominate artery of older apoE(-/-) mice could well be a model for the critical processes leading to the breakdown and healing of the human atherosclerotic plaque.     

自膨式支架治疗症状性基底动脉狭窄围手术期并发症的分析

目的探讨自膨式支架治疗基底动脉症状性粥样硬化性狭窄患者围手术期的并发症。方法回顾性分析2007年11月—2013年1月,51例接受Gateway球囊扩张+自膨式支架(Wing-span支架37例、Enterprise支架8例、Solitaire支架5例、Neuroform支架1例)置入治疗患者的临床资料。评估患者的临床表现、影像学特点及围手术期并发症发生率。结果①技术成功率为100%。基底动脉病变部位的平均狭窄率[中位数(M),范围]从术前的74(50～95)%下降至术后的26(0～48)%。4例(7.8%)患者出现了不同程度的言语不清、一侧肢体肌力减退等缺血症状,MRI检查提示桥脑新发梗死,考虑为穿支动脉闭塞引发的缺血事件。积极治疗后2例术后1个月症状缓解,2例仍有不同程度的神经功能障碍。②51例患者中有49%的狭窄部位在基底动脉下段,33.3%在中段,17.6%在上段。基底动脉上段狭窄支架置入治疗后,缺血并发症率高于基底动脉中下段(22.2%比4.8%),但因例数少,差异无统计学意义(χ2=3.115,P>0.05)。结论自膨式支架治疗基底动脉狭窄安全可行,但穿支动脉缺血事件是较常见的并发症,而且以基底动脉上段最为多见。     

Expression of heregulin in human coronary atherosclerotic lesions

BACKGROUND: Endothelial cells, monocytes/macrophages, and vascular smooth muscle cells contribute to the establishment and progression of atherosclerotic lesions by expressing growth and inflammatory factors. The aim of the present study was to determine whether heregulin (HRG) is associated with human coronary artery disease. METHODS: Twenty-six fresh human coronary artery segments were collected at autopsy. Expression of cysteine-rich 61 (CYR61) and VEGF in response to HRG was studied in the human endothelial cell line EA.hy926, and expression of CYR61 and HRG was evaluated in activated macrophages isolated from peripheral blood of healthy donors. RESULTS: We found that HRG was overexpressed at the protein and mRNA level in all lesions analyzed and gradually increased as the stages of the lesions progressed. Expression of HRG was observed in the intima primarily in macrophages. The same specimens were analyzed for the expression of CYR61, an angiogenetic factor regulated by HRG in breast cancer epithelial cells. CYR61 was expressed in both normal and atheromatic specimens, but its expression was significantly enhanced in macrophages of the intima. Activation of primary human macrophages results in increased expression of both HRG and CYR61. In addition, studies in endothelial cells where no endogenous HRG is present showed that HRG induces expression of CYR61 and secretion of VEGF. CONCLUSIONS: HRG may, therefore, play an important role in the development of coronary artery disease and the expansion of the atherosclerotic plaque and may locally regulate the expression of the angiogenetic factor CYR61.     

Localization of apolipoprotein E in normal and atherosclerotic human aorta

To elucidate the role of apolipoprotein E (apo E) in atherogenesis, we have investigated the localization of apo E in normal and atherosclerotic aortas as well as in other tissues of 32 post-mortem individuals. Using double immunofluorescence it has been found that normal intima of individuals older than 20 years and some adolescents contained immunoreactive material that reacted with poly- and monoclonal antibodies to apo E. A staining pattern of apo E differed from that of apolipoprotein B, the latter being seen in normal intima of each child older than 7 years. Apo E was present extracellularly in lipid streaks and atheromatous plaques, where its staining was particularly intensive around the necrotic zone of plaques. Some macrophages in the plaques of 4 aortas exhibited apo E-positive staining, while aortic endothelial and smooth muscle cells never contained apo E. Apo E-positive staining was not found in the majority of vessel cells, it was always, however, observed in other types of cells including hepatocytes. Kupffer cells, spleen macrophages and cerebral astrocytes. Our findings indicate that only some macrophages in human aorta may be responsible for the production of apo E that can participate in reverse cholesterol transport. At the same time, apo E accumulation in the aortic wall may promote the development of atherosclerosis.     

Expression of GM3 synthase in human atherosclerotic lesions

We have previously demonstrated that amounts of ganglioside GM3 are markedly higher in human atherosclerotic lesions compared to that in non-diseased arterial tissue. Because the fatty acid composition of GM3 in blood plasma low density lipoproteins (LDL) and the fatty acid composition of GM3 in atherosclerotic lesions differed, we hypothesized that, in addition to GM3 originating from LDL infiltrating the arterial wall from the blood, excessive GM3 may be synthesized locally in atherosclerotic lesions. In the present work, using an anti-GM3 antibody developed by us, we showed that the levels of GM3 synthase in membrane fractions isolated from the atherosclerotic intima were higher compared to those in non-diseased arterial tissue. Using an immunohistochemical approach, we examined the expression of GM3 synthase in sections of atherosclerotic plaques and non-diseased arterial wall. GM3 synthase immunopositivity was found to be low in non-diseased arterial intima but large numbers of GM3 synthase-immunopositive cells were observed in atherosclerotic plaques. GM3 synthase was overexpressed by macrophages and dendritic cells and double immunostaining demonstrated cellular co-localization of GM3 synthase and GM3. Further in vitro experiments showed that both monocyte-derived dendritic cells and macrophages expressed high levels of GM3 synthase. The findings of the present study indicate that, at least partially, excessive amounts of GM3 in atherosclerotic lesions can be synthesized by macrophages and dendritic cells directly within the arterial wall.     

Carotid artery lesions and atherosclerotic risk factors in Japanese hemodialysis patients

To determine the prevalence and severity of carotid artery lesions and which risk factors might be responsible for atherosclerosis in end-stage renal disease (ESRD) patients, we tested for carotid atherosclerosis (CA) by ultrasonography and compared the CA prevalence with well-known or suspected atherosclerotic risk factors in 226 hemodialysis (HD) patients and 2410 healthy residents of Japan. The CA prevalence was higher in the HD patients than in the healthy residents. Univariate analysis showed that HD patients with CA had a higher frequency of diabetes mellitus and left ventricular hypertrophy, and were significantly older, had significantly higher systolic blood pressure and pulse pressure, and lower albumin levels than those without. Multivariate analysis showed that age, pulse pressure, phosphorus, duration of HD, and diabetes mellitus were independent, significant predictors for CA in the HD patients. Neither Chlamydia pneumoniae seropositivity nor elevated homocysteine level was independently, significantly associated with CA. Our results suggest that HD patients had more advanced CA than the healthy residents. CA in the HD patients may be associated not only with several conventional risk factors but also with non-conventional risk factors such as phosphorus and the HD procedure itself.     

Vascular endothelial growth factor-D expression in human atherosclerotic lesions

OBJECTIVE: Vascular endothelial growth factor-D (VEGF-D) is a recently characterized member of the VEGF family, but its expression in atherosclerotic lesions remains unknown. We studied the expression of VEGF-D and its receptors (VEGFR-2 and VEGFR-3) in normal and atherosclerotic human arteries, and compared that to the expression pattern of VEGF-A. METHODS: Human arterial samples (n=39) obtained from amputation operations and fast autopsies were classified according to the stage of atherosclerosis and studied by immunohistochemistry. The results were confirmed by in situ hybridization and RT-PCR. RESULTS: We found that while VEGF-A expression increased during atherogenesis, VEGF-D expression remained relatively stable only decreasing in complicated lesions. In normal arteries and in early lesions VEGF-D was mainly expressed in smooth muscle cells, whereas in complicated atherosclerotic lesions the expression was most prominent in macrophages and also colocalized with plaque neovascularization. By comparing the staining profiles of different antibodies, we found that proteolytic processing of VEGF-D was efficient in the vessel wall. VEGFR-2, but not VEGFR-3, was expressed in the vessel wall at every stage of atherosclerosis. CONCLUSIONS: Our results suggest that in large arteries VEGF-D is mainly expressed in smooth muscle cells and that it may have a role in the maintenance of vascular homeostasis. However, in complicated lesions it was also expressed in macrophages and may contribute to plaque neovascularization. The constitutive expression of VEGFR-2 in arteries suggests that it may be one of the principal mediators of the VEGF-D effects in large arteries.     

锁骨下动脉粥样硬化性病变介入治疗的长期疗效观察

目的评价锁骨下动脉粥样硬化性病变介入治疗的长期疗效。方法对2003年3月至2011年6月沈阳军区总医院心血管内科诊治的72例锁骨下动脉狭窄或闭塞患者，实施经皮腔内血管成形术与支架植入术治疗，随访观察介入治疗后1年以上的临床疗效。结果72例患者中男性61例（84．7％），年龄（64．9±9．0）岁，吸烟史48例（66．7％），原发性高血压病史34例（47．2％），糖尿病史22例（30．6％）。术前临床表现肢体供血不足62例（86．1％）、椎基底供血不足27例（37．5％）、有血管杂音24例（33．3％）、血管搏动减弱或消失72例（100％）。介入手术成功66例（91．7％），失败6例（8．3％）。随访36（12～100）个月，随访率97．2％。上述四个方面临床治愈好转率分别为91．9％、88．9％、91．7％、93．1％，恶化病例1例，为介入治疗失败患者行外科人工血管置换术。介入成功患者患侧术后收缩压较其术前明显升高，差异有统计学意义[（115．00±21．21）mmHg vs.（82．92±51．01）mmHg，P〈0．05，1mmHg=0．133kPa]。结论经皮血管腔内介入治疗锁骨下动脉病变安全、有效，长期疗效明确。     

Blood velocity in the right coronary artery: relation to the distribution of atherosclerotic lesions

Vascular endothelial injury by high shear stresses and adverse effects of low shear rates on mass transfer across the arterial wall have been suggested as factors in atherogenesis. This study describes differences in blood velocity, and therefore differences of shear rate, across the lumen of the right coronary artery (RCA) of man. Selective coronary arteriograms of 30 patients without obstructive RCA disease were reviewed. Velocity was assessed qualitatively based on the rate of clearance of contrast material. There was a rapid clearing of contrast material along the outer wall of the RCA as it curved around the border of the heart. A much slower clearing occurred along the inner wall, bordering the myocardium, which persisted 2 to 6 cardiac cycles after the outer wall had cleared. This suggests that velocity, and therefore shear rate, is much lower along the inner wall of the RCA. To determine the relation of the distribution of atherosclerotic plaques in the RCA to local blood velocity, the RCA in 17 randomly selected human subjects who died of noncardiac disease were studied histologically. There was an uneven distribution of atherosclerotic plaques in the RCA with greater involvement of the inner wall. These observations demonstrate an association between the lower shear rate along the inner wall of the RCA and the site of higher concentration of atherosclerosis.