易损斑块的影像学检查方法

目前动脉粥样硬化斑块的影像学检查方法主要包括无创性（如多普勒超声、CT和MRI）和有创性（如DSA、血管内超声、血管内MRI）检查,每种检查方法各有优缺点,无创影像学评估易损斑块的比较研究有利于优化影像学检查技术。多种方法的联合应用,可以大大提高诊断准确率。     

Molecular mechanisms and therapeutic strategies of vulnerable atherosclerotic plaques

Vulnerable atherosclerotic plaque rupture leading to thrombosis is the major cause of acute coronary syndrome (ACS). Studies on the pathophysiologic mechanism of both ACS and plaque stabilizing treatment are driving the development of animal models of vulnerable plaque. In our laboratory, we established animal models of plaque rupture and thrombosis in rabbits and mice that are similar to human plaque rupture. Potential mechanisms involved in plaque vulnerability were studied from the inflammation-immunity, proliferation-apoptosis, oxidative stress and biomechanics aspects. Imaging markers and biomarkers were used to detect vulnerable plaques, including high frequency duplex ultrasound, intravascular ultrasound (IVUS), intravascular ultrasound elastography, magnetic resonance imaging (MRI) and inflammatory markers. Effective gene and drug strategies to treat vulnerable plaques were explored.     

多层螺旋CT评估冠状动脉分叉角度对动脉粥样硬化斑块形成的影响

目的探讨冠状动脉前降支（LAD）-对角支（DX）分叉角度与冠状动脉斑块形成和分布的相关性。方法选取我院行64层螺旋CT冠状动脉造影检查者72例,所选患者均无高血脂、高血压和糖尿病病史。原始图像经后处理工作站重建出冠状动脉的二维和三维图像。测量冠脉LAD-DX分叉角度、分叉管壁交点至斑块中心垂直线的直线距离,研究冠脉斑块距分叉处的距离和LAD-DX分叉角度的相关性。结果 33例前降支（LAD）存在斑块的患者中,LAD-DX分叉角度与斑块距分叉处的距离之间存在负相关。12例对角支（DX）有斑块者中,LAD-DX分叉角度与斑块距分叉处的距离之间无相关性。结论冠状动脉分叉角度作为一种潜在血流动力学因素对冠状动脉粥样斑块的形成和分布具有重要影响。     

18F-FDG PET与MRI联合检测颈动脉易损斑块的应用前景

颈动脉粥样硬化斑块的破裂是导致脑卒中发生的主要原因.利用18F-FDG PET联合MRI的方法可以同时提供斑块代谢、形态及成分方面的信息,大大提高诊断的灵敏度和特异性.     

Atherosclerosis imaging using 3D black blood TSE SPACE vs 2D TSE

AIM: To compare 3D Black Blood turbo spin echo (TSE) sampling perfection with application-optimized contrast using different flip angle evolution (SPACE) vs 2D TSE in evaluating atherosclerotic plaques in multiple vascular territories.METHODS: The carotid, aortic, and femoral arterial walls of 16 patients at risk for cardiovascular or atherosclerotic disease were studied using both 3D black blood magnetic resonance imaging SPACE and conventional 2D multi-contrast TSE sequences using a consolidated imaging approach in the same imaging session. Qualitative and quantitative analyses were performed on the images. Agreement of morphometric measurements between the two imaging sequences was assessed using a two-sample t-test, calculation of the intra-class correlation coefficient and by the method of linear regression and Bland-Altman analyses.RESULTS: No statistically significant qualitative differences were found between the 3D SPACE and 2D TSE techniques for images of the carotids and aorta. For images of the femoral arteries, however, there were statistically significant differences in all four qualitative scores between the two techniques. Using the current approach, 3D SPACE is suboptimal for femoral imaging. However, this may be due to coils not being optimized for femoral imaging. Quantitatively, in our study, higher mean total vessel area measurements for the 3D SPACE technique across all three vascular beds were observed. No significant differences in lumen area for both the right and left carotids were observed between the two techniques. Overall, a significant-correlation existed between measures obtained between the two approaches.CONCLUSION: Qualitative and quantitative measurements between 3D SPACE and 2D TSE techniques are comparable. 3D-SPACE may be a feasible approach in the evaluation of cardiovascular patients.     

颈动脉粥样硬化斑块新生血管的超声造影强化特征研究

目的 探讨颈动脉粥样硬化斑块新生血管的超声造影(contrast-enhanced ultrasonography,CEUS)强化特征。 方法 运用实时超声造影技术对78例有颈动脉粥样硬化斑块患者进行斑块新生血管强化特征分级和量化分析,探讨斑块新生血管灌注模式以及斑块强化与斑块厚度的关系,并根据斑块回声分类进行斑块强化特征的组间比较。对5例患者颈动脉内膜剥脱术后斑块的病理组织学微血管计数与术前斑块超声造影强化指标进行相关分析。 结果 78个斑块常规超声显示低回声斑23 例（29.49％）, 混合回声斑30 例（38.46％）,等回声斑20 例（25.64％）, 高回声斑5例（6.41％）;斑块最厚者5.5 mm ,最薄者2.6 mm。本组60例（76.9%）颈动脉粥样硬化斑块CEUS显示不同程度的新生血管强化。斑块厚度与斑块强化程度存在相关关系（r=0.686,P<0.05）。低回声斑和混合回声斑强化程度高于等回声斑及高回声斑（P<0.05）;斑块病理组织学新生血管数量分级与超声造影强化程度呈正相关（r=0.886,P<0.05）。 结论 超声造影能够实时地观察和评价颈动脉粥样硬化斑块内的新生血管的灌注特征,为斑块易损性的临床评估提供了新的影像学检查方法。     

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。     

Discovering and differentiating new and emerging clonal populations of Chlamydia trachomatis with a novel shotgun cell culture harvest assay

Chlamydia trachomatis is the leading cause of preventable blindness and bacterial sexually transmitted diseases worldwide. Plaque assays have been used to clonally segregate laboratory-adapted C. trachomatis strains from mixed infections, but no assays have been reported to segregate clones from recent clinical samples. We developed a novel shotgun cell culture harvest assay for this purpose because we found that recent clinical samples do not form plaques. Clones were strain-typed by using outer membrane protein A and 16S rRNA sequences. Surprisingly, ocular trachoma reference strain A/SA-1 contained clones of Chlamydophila abortus. C. abortus primarily infects ruminants and pigs and has never been identified in populations where trachoma is endemic. Three clonal variants of reference strain Ba/Apache-2 were also identified. Our findings reflect the importance of clonal isolation in identifying constituents of mixed infections containing new or emerging strains and of viable clones for research to more fully understand the dynamics of in vivo strain-mixing, evolution, and disease pathogenesis.     

Thirty-nine-month xylitol chewing-gum programme in initially 8-year-old school children: a feasibility study focusing on mutans streptococci and lactobacilli

AIM: To investigate the use of xylitol-containing chewing-gums in public elementary schools as a means to affect the growth of salivary and plaque mutans streptococci and salivary lactobacilli. DESIGN: Over a period of 24 months, 750 8- to 9-year-old children chewed xylitol (X group; n = 255) or xylitol-sorbitol (XS group; n = 264) gum on school days (454 days over 2 years), or chewed no gum at all (C group; n = 231). Consumption of xylitol in the X and the XS groups was 6.6 and 5.4g per day, respectively. Use of gum took place at school in four daily episodes of which three were supervised by teachers. Following the 24-month chewing-gum period, the subjects were re-examined after 15 months (total follow-up period: 39 months) at which time an extraneous comparison group (ExC; n = 117) was also examined. The numbers of subjects examined after 39 months were: X, 239; XS, 248; C3 217. METHODS: Salivary and plaque levels of mutans streptococci and the salivary levels of aerobically cultured aciduric bacteria (mostly representing lactobacilli) were determined using the Orion Diagnostica Dentocult SM and LB test kits, respectively. RESULTS: There were statistically significant differences after 24 and 39 months between the two xylitol chewing-gum groups and the C group with regard to salivary and plaque mutans streptococci and salivary lactobacilli: the use of xylitol-containing chewing-gums significantly reduced these bacterial scores. The reductions were statistically more significant in the X group than in the XS group. The bacterial scores of groups C and ExC were similar. CONCLUSIONS: Long-term use of xylitol-containing chewing-gum can reduce the growth of mutans streptococci in saliva and dental plaque, and lactobacilli-type bacteria in saliva, even if xylitol is used only on school days. The results also suggest that xylitol gum use can have a long-term, delayed growth-retarding effect on these micro-organisms, since reduced bacterial growth was still observed 15 months following the termination of xylitol use. The results indicate a close biochemical relationship between xylitol and mutans streptococci, and suggest that a similar relationship may exist regarding aerobically cultured aciduric bacteria present in saliva.     

颈动脉粥样硬化斑块影像学评估研究进展

对于颈动脉斑块的评估,经典的策略是通过影像学进行狭窄程度分级,从而决定临床干预方式。而随着临床经验和研究证据的积累,人们逐渐认识到斑块稳定性这一指标比狭窄程度更能准确反映患者的症状和预后、评估再血管化指征。本文整合了近年来经典或新型影像技术(超声、计算机断层扫描、磁共振、分子成像等)的研究进展,分析了这些技术在斑块形态及稳定性方面评估的原理和优劣,为临床提供参考。