动脉粥样硬化易损斑块的分子影像研究进展

动脉粥样硬化是心脑血管疾病最主要的病因,而其中易损斑块的突然破损所诱发的血小板聚集和血栓形成是引起脑卒中和急性心肌梗死的重要发病机制.如何更有效地早期诊断动脉粥样硬化的易损斑块是目前研究的热点.文章主要就近年来分子影像技术用于动脉粥样硬化易损斑块的评价研究进行综述.     

冠状动脉易损斑块影像学最新研究进展

冠心病(CAD)是世界上致死率最高的疾病之一,其中,以急性冠状动脉综合征(ACS)病情最为凶险,而近70%的急性冠脉事件并不是由显著地冠状动脉狭窄引起,而是由冠状动脉易损斑块(vulnerable plaque)破裂造成的急性狭窄,以及其后血栓形成所致,因此冠状动脉易损斑块是导致急性冠状动脉综合征的主要元凶,因此需要早期发现易损斑块并积极进行干预。近两年来,CT、MRI、血管内超声(IVUS)和光学相干断层成像(OCT)广泛应用于易损斑块的评估并取得显著进展,而分子影像学能从分子层面揭示易损斑块形成机制以及更加早期识别斑块进行。本文简要总结近两年影像学方法对易损斑块的最新研究进展及热点。     

血清妊娠相关血浆蛋白A在诊断异常妊娠中的临床意义

目的:探讨血清妊娠相关血浆蛋白A(PAPP-A)在诊断异常妊娠中的临床意义,分析其与异常妊振的关系。方法:选取299例5~13周的正常早孕妇为正常早孕组,同期选取稽留流产86例,先兆流产54例,异位妊娠76例为异常妊娠组,用酶联免疫吸附试验(ELASA)测定两组受试者的血清PAPP-A水平,分析两组受试者各个孕周内的血清PAPP-A水平的差异。结果:稽留流产孕妇在各个孕周内(9~13周)的血清PAPP-A水平显著低于同孕周内正常早孕孕妇(t值分别为9.500,8.113,3.511,9.538,8.504,P值均0.05);稽留流产孕妇总的平均血清PAPP-A水平亦低于常早孕孕妇(t=3.651,P值均0.05);异位妊娠孕妇在各个孕周内(9~13周)的血清PAPP-A水平显著低于同孕周内正常早孕孕妇(t值分别为7.976,9.030,9.941,11.625,14.079,12.569,P值均0.05),异位妊娠孕妇总的平均血清PAPP-A水平亦低于常早孕孕妇(t=28.168,P值均0.05);先兆流产孕妇(除孕8周)与正常早孕妊娠血清PAPP-A水平比较无显著统计学意义。结论:血清PAPP-A水平在异常妊娠如异位妊娠、稽留流产中显著降低,可作为诊断异位妊娠、稽留流产及先兆流产辅助诊断的生物学指标。     

动脉粥样硬化易损斑块的核医学和磁共振分子影像学研究进展

动脉粥样硬化分子影像学通过使用具有敏感性和特异性影像对比的分子探针针对动脉粥样硬化斑块相关的特定分子进行分子成像.该方法会极大地提高对动脉粥样硬化病变特性的检测水平和增强对该病变特征,尤其对斑块的组成成份的识别能力.斑块的组成成份和斑块的破裂、斑块的易损性以及斑块破裂后导致的结果密切相关.因此了解斑块组成成份的在体无创性检测将对动脉粥样硬化病人的治疗和判断预后产生非常重要的临床应用价值.     

老年急性脑梗死患者外周血EMMPRIN表达与颈动脉易损斑块的相关性

目的:分析老年急性脑梗死(acute cerebral infarction,ACI)患者外周血血小板表面细胞外基质金属蛋白酶诱导因子(EMMPRIN)表达与颈动脉易损斑块的相关性。方法:收集2017年3月至2019年3月于我院收治的老年ACI患者作为研究对象,按照超声下颈动脉斑块的分类标准,将颈动脉斑块呈高回声受检者纳入稳定斑块组(n=41),斑块呈低回声或等回声的受检者则纳入易损斑块组(n=52)。应用logisitc回归模型,分析ACI患者颈动脉易损斑块的影响因素;采用Pearson相关分析,研究外周血单个核细胞EMMPRIN与各临床指标的相关性;采用受试者工作特征(ROC)曲线评价EMMPRIN诊断颈动脉易损斑块的准确性。结果:易损斑块组高脂血症、高血压病、2型糖尿病比例以及FPG、IL-6、IL-1β、MMP-9、MCP-1、TNF-α、LDL、EMMPRIN水平均高于稳定斑块组,组间差异显著(P0.05);易损斑块组HDL水平均低于稳定斑块组,组间差异显著(P0.05)。person相关分析结果显示,EMMPRIN与IL-6、IL-1β、MMP-9、TNF-α均呈正相关(r=0.348,0.374,0.418,0.427,P0.05)。logistic多因素回归分析显示,结果显示,高血压病、2型糖尿病、IL-1β、MMP-9、EMMPRIN均为颈动脉易损斑块的危险因素。EMMPRIN的AUC优于MMP-9、IL-1β(P=0.016,0.039,均P0.05)。结论:外周血血小板表面EMMPRIN水平可能与老年ACI患者颈动脉斑块稳定性有关,可作为辅助临床诊断颈动脉易损斑块的预警指标,对于ACI的发生、发展均具有重要的临床意义。     

急性冠脉综合征患者PAPP-A基因IVS6+95(C/G)多态性与血浆PAPP-A水平及斑块性质的相关性

为研究湖北十堰地区急性冠脉综合征(ACS)患者PAPP-A基因IVS6 +95(C/G)多态性与血浆PAPP-A水平和斑块性质的相关性,随机选择215例ACS患者(包括58例急性心肌梗死(AMI)患者、73例不稳定型心绞痛(UAP)患者和84例稳定型心绞痛(SAP)患者)及142例健康对照者作为研究对象,检测PAPP-A基因IVS6+ 95 (C/G)多态性和血浆PAPP-A浓度,并进行统计学分析.结果显示,AMI组、UAP组和SAP组的PAPP-A浓度具有极显著差异(p＜0.01),在稳定性斑块和易损性斑块组间的PAPP-A浓度亦具有极显著差异(p＜0.01);AMI组、UAP组和SAP组与对照组间的基因型频率和等位基因频率具有显著差异(p＜0.05);在ACS组和对照组中,组内各类基因型人群的血浆PAPP-A浓度的差异不显著(p＞0.05).结果表明,PAPP-A基因IVS6+ 95多态性与急性冠脉综合征患者密切相关,血浆PAPP-A浓度与斑块性质相关,能够反映ACS患者斑块的易损性,是ACS患者危险分层的标志物.     

瑞舒伐他汀对兔动脉粥样硬化斑块及血清PAPP-A的影响

目的:探讨瑞舒伐他汀对兔动脉粥样硬化斑块及血清妊娠相关血浆蛋白(PAPP-A)的影响.方法:新西兰家兔18只,随机分为正常对照组(Normal组,n=6)、动物粥样梗化模型组(AS组,n=6)和瑞舒伐他汀治疗组(RSV组,n=6).于治疗前、治疗后,检测血清总胆固醇(TC)、三酰甘油(TG)、血清低密度脂蛋白胆固醇(LDL-C)及高密度脂蛋白胆固醇(HDL-C)含量,酶联免疲吸附法(ELISA)检测血清PAPP-A水平.同时,用血管内超声检查(IVUS)测定病变部位的血管外弹力膜面积(EEMA)、管腔面积(LA)和斑块面积(PA),计算管腔面积狭窄百分率(LAS%).结果:治疗前,AS组和RSV组兔的血清TC、TG、LDL-C及PAPP-A的水平较Normal组高(P<0.01),HDL-C的水平较Normal组低(P<0.01);治疗后,RSV组兔的血清TC、TG、LDL-C及PAPP-A比AS组低(P<0.01).HDL-C的水平比AS组高(P<0.01),且RSV组兔的血清TC、TG、LDL-C及PAPP-A的水平较治疗前低(P<0.01),HDL-C的水平较治疗前高(P<0.01).血管内超声检查结果显示,治疗后,RSV组兔的LAS%(30.87%±5.27%)比AS组低(37.42%±6.12%)(P<0.01).结论:瑞舒伐他汀能改善对AS兔血脂,减少AS斑块形成及降低血清PAPP-A水平.     

妊娠血清标志物的联合检测在预测胚胎停止发育中的价值

目的:探讨血清孕酮(p)、妊娠相关血浆蛋白A(PAPP-A)、血管内皮生长因子(VEGF)在胚胎停止发育的早期诊断和预测的价值.方法:选择100例孕龄在6～7周的单胎孕妇,追踪85例妊娠结局,据妊娠结局分为正常妊娠组68例,胚胎停止发育而自然流产者为胚胎停育组17例;检测血清P、PAPP-A、VEGF水平,建立ROC曲线,评价指标的诊断价值.结果:(1)胚胎停育组血清P和PAPP-A、VEGF水平均显著低于正常妊娠组(P＜0.001).(2)P与PAPP-A呈正相关,P与VEGF呈正相关(p＜0.001).(3)以P＜14.996ng/ml、VEGF＜26.505pg/ml为临界值,二者联合检测可使胚胎停止发育诊断阳性率达94.12%,特异性为88.2%.结论:血清P、VEGF联合检测敏感性高,对胚胎停育的早期诊断和预测有一定价值.     

SARS-CoV 基因组编码蛋白研究进展

严重急性呼吸综合征(severe acute respiratory syndrome,SARS)2002年底暴发于中国广东,后蔓延至全球的传染性疾病．其病原体为一种新型的未知冠状病毒,基因组长度约30 kb,预测具有14个开放读码框．至今为止,对 SARS 冠状病毒(SARS-COV)基因组编码蛋白质的研究已取得显著进展,其研究主要集中在复制酶 1a/1b、结构蛋白及“附属”蛋白(SARS-CoV 特异性蛋白)结构与功能的研究．以 SARS-CoV 的蛋白组成及功能研究为主要内容,系统介绍了 SARS-CoV 蛋白质研究进展．     

植物胞间连丝相关蛋白研究进展

概要综述近几年来植物胞间连丝相关蛋白(PAPs)与动物间隙连接蛋白(connexins)的同源性、PAPS的定位、PAPS的磷酸化、以及PAPs的分子生物学的最新研究进展, 并展望该领域的研究前景.     

Retracted: Downregulated microRNA-224 aggravates vulnerable atherosclerotic plaques and vascular remodeling in acute coronary syndrome through activation of the TGF-β/Smad pathway

Recent studies have shown that circulating microRNAs (miRNA) play a critical role in diagnosing acute coronary syndrome (ACS). This study aims to investigate the effect of miR-224 on atherosclerotic plaques forming and vascular remodeling in ACS and its relationship with TGF-β/Smad pathway. Myocardial infarction (MI) rat model was established and lentivirus vector of miR-224 inhibitor was prepared for investigating the effect of downregulated miR-224 on the contents of nitric oxide (NO) and endothelin-1 (ET-1), blood lipid levels and inflammatory factor levels in serum as well as the TGF-β/Smad pathway. The rats suffering from MI had decreased survival rates and exhibited reduced levels of NO, high-density lipoprotein cholesterol, and lumen diameter, and Smad7 messenger RNA (mRNA) and protein expression; while had significantly increased ratio of heart weight or body weight, levels of ET-1, inflammatory factors, blood lipid indexes, vascular remodeling indexes, collagen volume fraction, vulnerable atherosclerotic plaque area, VCAM-1 and MMP-2 protein expression, TGF-β, Smad2, Smad3, and Smad4 mRNA and protein expression. After inhibiting the TGF-β/Smad pathway, the rats suffering from MI showed notably opposite trend. In conclusion, downregulation of miR-224 expression promotes the formation of vulnerable atherosclerotic plaques and vascular remodeling in ACS through activation of the TGF-β/Smad pathway. Therefore, this study provides a new therapeutic target for ACS.     

The roles of myeloperoxidase in coronary artery disease and its potential implication in plaque rupture

Atherosclerosis is the main pathophysiological process underlying coronary artery disease (CAD). Acute complications of atherosclerosis, such as myocardial infarction, are caused by the rupture of vulnerable atherosclerotic plaques, which are characterized by thin, highly inflamed, and collagen-poor fibrous caps. Several lines of evidence mechanistically link the heme peroxidase myeloperoxidase (MPO), inflammation as well as acute and chronic manifestations of atherosclerosis. MPO and MPO-derived oxidants have been shown to contribute to the formation of foam cells, endothelial dysfunction and apoptosis, the activation of latent matrix metalloproteinases, and the expression of tissue factor that can promote the development of vulnerable plaque. As such, detection, quantification and imaging of MPO mass and activity have become useful in cardiac risk stratification, both for disease assessment and in the identification of patients at risk of plaque rupture. This review summarizes the current knowledge about the role of MPO in CAD with a focus on its possible roles in plaque rupture and recent advances to quantify and image MPO in plasma and atherosclerotic plaques.     

The role of nitric oxide in lung innate immunity: Modulation by surfactant protein-A

Surfactant protein A (SP-A) and alveolar macrophages are essential components of lung innate immunity. Alveolar macrophages phagocytose and kill pathogens by the production of reactive oxygen and nitrogen species. In particular, peroxynitrite, the reaction product of superoxide and nitric oxide, appears to have potent antimicrobial effects. SP-A stimulates alveolar macrophages to phagocytose and kill pathogens and is important in host defense. However, SP-A has diverse effects on both innate and adaptive immunity, and may stimulate or inhibit immune function. SP-A appears to mediate toxic or protective effects depending on the immune status of the lung. In contrast to mouse or rat cells, it has been difficult to demonstrate nitric oxide production by human macrophages. We have recently demonstrated that human macrophages produce nitric oxide and use it to kill Klebsiella pneumoniae. SP-A either stimulates or inhibits this process, depending on the activation state of the macrophage. Given its diverse effects on immune function, SP-A may prove to be an effective therapy for both infectious and inflammatory diseases of the lung.     

Trimerization Domain of the Collagen Tail of Acetylcholinesterase

In the collagen-tailed forms of cholinesterases, each subunit of a specific triple helical collagen, ColQ, may be attached through a proline-rich domain (PRAD) situated in its N-terminal noncollagenous region, to tetramers of acetylcholinesterase (AChE) or butyrylcholinesterase (BChE). This heteromeric assembly ensures the functional anchoring of AChE in extracellulare matrices, for example, at the neuromuscular junction. In this study, we analyzed the influence of deletions in the noncollagenous C-terminal region of ColQ on its capacity to form a triple helix. We show that an 80-residue segment located downstream of the collagenous regions contains the trimerization domain, that it can form trimers without the collagenous regions, and that a pair of cysteines located at the N-boundary of this domain facilitates oligomerization, although it is not absolutely required. We further show that AChE subunits can associate with nonhelical collagen ColQ monomers, forming ColQ-associated tetramers (G₄-Q), which are secreted or are anchored at the cell surface when the C-terminal domain of ColQ is replaced by a GPI-addition signal.     

The protein-A plaque assay: a new system for the detection of cells secreting a given idiotype

With a modification of the protein-A plaque assay, cells secreting a given idiotype could be detected. Different anti-idiotypic antisera raised against the M-component of macroglobulinemia Waldenstr?m patients were used. The antibodies did not cross-react with cell clones of other patients or normal controls. Spontaneous plaques, without prior cultivation, were mainly shown to be of IgM class, the majority being idiotype specific, in blood and bone marrow lymphocytes from these patients. This is in contrast to the predominance of Ig or IgA found in normal blood donors. A low but recognizable stimulation of the malignant clone may be observed when cells were stimulated by certain polyclonal B cell activators.     

Apelin: a new plasma marker of cardiopulmonary disease

OBJECTIVES: Dyspnea is a major symptom of both parenchymal lung disease and chronic heart failure. Underlying cardiac dysfunction can be assessed by measurement of cardiac-derived B-type natriuretic peptide or its precursor in plasma. However, no specific endocrine marker of the lung parenchyma has so far been identified. We therefore examined whether plasma concentrations of apelin, a novel inotropic hormone, is affected in patients with chronic parenchymal lung disease without cardiac dysfunction. METHODS AND RESULTS: Patients with severe chronic parenchymal lung disease and normal cardiac function (n=53), idiopathic pulmonary hypertension with increased right ventricular pressure (n=10), and patients with severe left ventricular systolic dysfunction (n=22) were enrolled. Plasma apelin-36 and proBNP concentrations were measured with radioimmunoassays. While proBNP plasma concentrations were unaffected in chronic parenchymal lung disease patients compared to normal subjects, the apelin-36 concentration was reduced 3.3-fold (median 35 pmol/l (0-162 pmol/l) vs. 117 pmol/l (55-232 pmol/l), P<0.001). Moreover, the apelin-36 concentration was decreased in chronic heart failure patients (2.1-fold, P<0.01) and in patients with idiopathic pulmonary hypertension (4.0-fold, P<0.001). In contrast, the proBNP concentration was highly increased in both chronic heart failure and idiopathic pulmonary hypertension patients. CONCLUSION: Plasma concentrations of apelin-36, a novel inotropic peptide, are decreased in patients with chronic parenchymal lung disease and preserved cardiac function. Combined measurement of apelin-36 and proBNP may be a new diagnostic approach in distinguishing pulmonary from cardiovascular causes of dyspnea.     

Chest pain in the emergency room: value of the HEART score

Background. Chest pain is one of the most common causes of presentation to the emergency room. The diagnosis of non-ST-elevation acute coronary syndrome typically causes uncertainty. Classical considerations for risk stratification are History, ECG, Age, Risk factors and Troponin (HEART). Each can be scored with zero, one or two points, depending on the extent of the abnormality. The HEART score is the sum of these five considerations. Methods. Clinical data from 122 patients referred to the emergency room for chest pain were analysed. The predictive value of the HEART score for reaching an endpoint was evaluated in 120/122 patients. Results. Twenty-nine patients reached one or more endpoints: an acute myocardial infarction was diagnosed in 16 patients, 20 underwent revascularisation and two died. The HEART score in the patients with and without an endpoint was 6.51±1.84 and 3.71±1.83 (p<0.0001) respectively. A HEART score of 0-3 points holds a risk of 2.5% for an endpoint and supports an immediate discharge. With a risk of 20.3%, a HEART score of 4-6 points implies admission for clinical observation. A HEART score ≥7points, with a risk of 72.7%, supports early invasive strategies. Conclusion. The HEART score facilitates accurate diagnostic and therapeutic choices. The HEART score is an easy, quick and reliable predictor of outcome in chest pain patients. (Neth Heart J 2008;16:191-6.)     

Synergistic degradation of bovine serum albumin by mutans streptococci and other dental plaque bacteria

Mutans streptococci (Streptococcus mutans and Streptococcus sobrinus) exhibited low levels of proteolytic activity against the model protein substrate, FITC-labelled bovine serum albumin, when incubated alone. Inclusion of other members of the dental plaque microflora in the assay usually resulted in marked increases in the degree of proteolysis and a high level of synergy. Interactions between mutans streptococci and either Streptococcus oralis or Fusobacterium nucleatum gave rise to the greatest degree of synergistic proteolytic degradation.