Confocal Blood Flow Videomicroscopy of Thrombus Formation over Human Arteries and Local Targeting of P2X7

Atherothrombosis exposes vascular components to blood. Currently, new antithrombotic therapies are emerging. Herein we investigated thrombogenesis of human arteries with/without atherosclerosis, and the interaction of coagulation and vascular components, we and explored the anti-thrombogenic efficacy of blockade of the P2X purinoceptor 7 (P2X7). A confocal blood flow videomicroscopy system was performed on cryosections of internal mammary artery (IMA) or carotid plaque (CPL) determining/localizing platelets and fibrin. Blood from healthy donors elicited thrombi over arterial layers. Confocal microscopy associated thrombus with tissue presence of collagen type I, laminin, fibrin(ogen) and tissue factor (TF). The addition of antibodies blocking TF (aTF) or factor XI (aFXI) to blood significantly reduced fibrin deposition, variable platelet aggregation and aTF + aFXI almost abolished thrombus formation, showing synergy between coagulation pathways. A scarce effect of aTF over sub-endothelial regions, more abundant in tissue TF and bundles of laminin and collagen type I than deep intima, may suggest tissue thrombogenicity as molecular structure-related. Consistently with TF-related vascular function and expression of P2X7, the sections from CPL but not IMA tissue cultures pre-treated with the P2X7 antagonist A740003 demonstrated poor thrombogenesis in flow experiments. These data hint to local targeting studies on P2X7 modulation for atherothrombosis prevention/therapy.     

Feature extraction by autoregressive spectral analysis using maximum likelihood estimation: internal carotid arterial Doppler signals

Abstract: In this study, Doppler signals recorded from the internal carotid artery (ICA) of 97 subjects were processed by personal computer using classical and model-based methods. Fast Fourier transform (classical method) and autoregressive (model-based method) methods were selected for processing the ICA Doppler signals. The parameters in the autoregressive method were found by using maximum likelihood estimation. The Doppler power spectra of the ICA Doppler signals were obtained by using these spectral analysis techniques. The variations in the shape of the Doppler spectra as a function of time were presented in the form of sonograms in order to obtain medical information. These Doppler spectra and sonograms were then used to compare the applied methods in terms of their frequency resolution and the effects in determination of stenosis and occlusion in the ICA. Reliable information on haemodynamic alterations in the ICA can be obtained by evaluation of these sonograms.     

侧颅底手术过程中脑及颅神经功能保护

手术是绝大部分侧颅底病变的首选治疗方式。因侧颅底解剖结构复杂,毗邻脑及重要血管神经,手术容易致死或致残,限制了该部位手术的实施。脑、后组颅神经、面神经、听力功能是该部位手术保护的重点,恰当处理功能保留和切除病变的关系、良好的外科操作技能以及合理使用介入、导航等新的辅助技术是侧颅底手术中实现器官功能保护的关键。     

Cerebral Hyperperfusion after Revascularization Inhibits Development of Cerebral Ischemic Lesions Due to Artery-to-Artery Emboli during Carotid Exposure in Endarterectomy for Patients with Preoperative Cerebral Hemodynamic Insufficiency: Revisiting the “Impaired Clearance of Emboli” Concept

The purpose of the present study was to determine whether cerebral hyperperfusion after revascularization inhibits development of cerebral ischemic lesions due to artery-to-artery emboli during exposure of the carotid arteries in carotid endarterectomy (CEA). In patients undergoing CEA for internal carotid artery stenosis (≥70%), cerebral blood flow (CBF) was measured using single-photon emission computed tomography (SPECT) before and immediately after CEA. Microembolic signals (MES) were identified using transcranial Doppler during carotid exposure. Diffusion-weighted magnetic resonance imaging (DWI) was performed within 24 h after surgery. Of 32 patients with a combination of reduced cerebrovascular reactivity to acetazolamide on preoperative brain perfusion SPECT and MES during carotid exposure, 14 (44%) showed cerebral hyperperfusion (defined as postoperative CBF increase ≥100% compared with preoperative values), and 16 (50%) developed DWI-characterized postoperative cerebral ischemic lesions. Postoperative cerebral hyperperfusion was significantly associated with the absence of DWI-characterized postoperative cerebral ischemic lesions (95% confidence interval, 0.001–0.179; p = 0.0009). These data suggest that cerebral hyperperfusion after revascularization inhibits development of cerebral ischemic lesions due to artery-to-artery emboli during carotid exposure in CEA, supporting the “impaired clearance of emboli” concept. Blood pressure elevation following carotid declamping would be effective when embolism not accompanied by cerebral hyperperfusion occurs during CEA.     

颞骨及岩骨段颈内动脉的断面解剖学研究与三维模型构建

目的：为解剖学习和临床影像诊断及手术治疗提供颞骨及岩骨段颈内动脉（petrous carotid artery,PCA）的三维立体形态学参数。方法：该研究中,我们采用数字化可视人（中国首例女性）的数据集（该断层层厚较薄,霞建图像更逼真,数据更精确）,对颞骨及PCA进行断面解剖学观察,提取相关断面图像信息,分别应用Adobe．photoshopCS3、AmiFa和Maya软件。对颞骨及PCA进行计算机三维重建和虚拟现实显示。结果：通过3个典型的层面（即外半规管层面、前庭窗层面、咽鼓管层面）,对其主要结构的断面形态及毗邻关系进行描述。重建三维模型可清楚地显示颢骨内部结构和PCA的形态和空间位置关系,同时尚可任意角度旋转、切割、组合和整体显示相关结构。PCA水平段与PCA弯曲部和内耳道内侧缘连线的夹角平均值为67．5度。结论：采用三维重建技术重建的颢骨及PCA结构清晰,其构建模型可较为准确地揭示颢骨内部结构及与PCA的毗邻关系,为解剖学习和临床应用提供更为直观便捷的参考。     

粉防己碱对血管性痴呆大鼠齿状回S100B蛋白表达的研究

目的：探讨粉防己碱（Tet）对血管性痴呆（VaD）大鼠齿状回S100B蛋白表达的影响以及在血管性痴呆发病中的作用。方法：运用双侧颈总动脉永久性结扎（2-VO法）建立VaD大鼠模型,Nissl染色观察海马齿状回（DG）神经元内的尼氏小体的变化,免疫荧光观察海马DG区S100B的表达情况,F1uo-3/AM探针负载后检测各组大鼠海马内〔Ca2＋〕i浓度变化,探讨Tet改善VaD大鼠神经功能的分子机制。结果：Nissl染色后,Tet干预组大鼠海马DG区尼氏小体较模型组显著增多;免疫标记发现Tet干预组大鼠DG区神经元内S100B蛋白的表达量明显增多;Tet干预组大鼠海马〔Ca2＋〕i浓度显著下降（p〈0.05）。结论：Tet可改善大鼠脑缺血损伤引起的学习记忆能力障碍,可能与Tet下调S100B蛋白,抑制钙离子有关。     

一种基于光流的GVF主动轮廓线模型在颈动脉超声动态图像序列边缘提取中的运用

颈动脉超声图像边缘的提取对冠状动脉疾病的诊断和治疗有着重要的意义。本文提出了一种针对颈动脉超声动态图像序列的边缘跟踪方法。根据前一帧图像的边界轮廓,通过计算当前帧与前一帧之间的光流场来预测当前帧图像的初始轮廓,再使用GVF主动轮廓线方法进行分割。然后依次处理图像序列的每一帧图像。实验证明,这种方法相对与独立的分割每帧图像更有效率,并且由于使用了光流来进行预测,具有很好的动态跟踪能力。     

A novel automatic algorithm for the segmentation of the lumen of the carotid artery in ultrasound B-mode images

A novel algorithm is proposed for the segmentation of the lumen and bifurcation boundaries of the carotid artery in B-mode ultrasound images. It uses the image contrast characteristics of the lumen and bifurcation of the carotid artery in relation to other tissues and structures for their identification. The relevant ultrasound data regarding the artery presented in the input image is identified using morphologic operators and processed by an anisotropic diffusion filter for speckle noise removal. The information obtained is then used to define two initial contours, one corresponding to the lumen and the other one regarding the bifurcation boundaries, for the application of the Chan-Vese level set segmentation model. A set of longitudinal ultrasound B-mode grayscale images of the common carotid artery was acquired using a GE Healthcare Vivid-e ultrasound system. The results reveal that the new algorithm is effective and robust, and that its main advantage relies on the automatic identification of the carotid lumen, which overcomes the known limitations of the traditional algorithms.     

维格列汀联合二甲双胍治疗对2型糖尿病合并心脑血管疾病 IMT、血清 APN 及 Hcy 水平的影响

目的：观察维格列汀联合二甲双胍治疗对2型糖尿病合并心脑血管疾病颈动脉内膜中层厚度（carotid inti-ma-media thickness,IMT）、血清脂联素（adiponectin,APN）和同型半胱氨酸（homocysteine,Hcy）水平的影响,探讨2型糖尿病并发心脑血管疾病的危险因素。方法将150例初诊2型糖尿病合并心脑血管疾病患者随机分为3组：A 组50例采用维格列汀治疗,B 组50例采用二甲双胍治疗,C 组50例采用维格列汀联合二甲双胍治疗,治疗3个月后,比较3组治疗前后血糖控制情况及 IMT、APN 和 Hcy 水平改善情况。结果治疗后 A、C 组 IMT、Hcy 均较治疗前明显降低,APN 较治疗前明显增加,且 C 组改善程度较 A、B 组更为显著（P ＜0．05）。相关分析结果显示,IMT 与 HOMA-IR（r＝0．356,P ＝0．013）、LDL（r＝0．363,P ＝0．009）、Hcy（r＝0．756,P ＝0．022）呈正相关,与HDL（r＝－0．461 P ＝0．001）、APN（r＝－0．482,P ＝0．000）呈负相关。结论 HOMA-IR、LDL、Hcy 升高,HDL、APN 降低是2型糖尿病患者 IMT 增厚的危险因素。维格列汀联合二甲双胍治疗可有效降低其 IMT 值及 Hcy 水平,增加 APN 含量。     

子宫切除后绝经妇女颈动脉内中膜厚度及血管内皮功能的变化及意义

目的探讨子宫切除后绝经妇女血管内皮功能、颈动脉内中膜厚度（intima-media thickness,IMT）的变化及二者与动脉粥样硬化的关系。方法应用高分辨率彩色多普勒超声检测45例子宫切除后绝经妇女和45例绝经前妇女（对照组）的颈动脉IMT、粥样斑块及肱动脉血流介导的血管舒张功能（flow-mediated-vasodilation,FMD）,分析其变化。结果子宫切除后绝经组患者颈动脉IMT较对照组明显增厚（P〈0.01）,粥样斑块发生率较对照组明显增高（P〈0.01）;肱动脉FMD明显低于对照组（P〈0.01）。结论子宫切除后绝经妇女FMD损伤,从而引起颈动脉IMT增厚及粥样斑块的形成。因此子宫切除后绝经妇女血管内皮功能损伤促进了动脉粥样硬化的发生,从而导致子宫切除后绝经妇女心血管疾病发病率的剧增。