Association of CD36 gene polymorphisms with echo- and electrocardiographic parameters in patients with early onset coronary artery disease

Introduction

CD36 plays an important role in long-chain fatty acid homeostasis in skeletal muscle and the myocardium. CD36 deficiency may lead to reduced myocardial uptake of long-chain fatty acid. Therefore, different mutations of the CD36 gene may contribute to the clinical heterogeneity of cardiac hypertrophy.

Material and methods

The objective of the study was to investigate whether there is an association between the sequence changes in CD36 and echocardiographic and electrocardiographic parameters in Caucasian patients with early onset coronary artery disease. The study group comprised 100 patients. Electrocardiography and echocardiography were performed in all patients. Amplicons of exons 4 to 6 including fragments of introns were studied using the denaturing high-performance liquid chromatography technique.

Results

IVS3-6TC (rs3173798) heterozygotes had impaired left ventricle diastolic function. 573GA heterozygotes (rs5956) had higher frequency of pseudonormal left ventricular diastolic function and it was confirmed by the increase in wave A’ in the tissue Doppler. 591AT genotype was associated with borderline higher posterior wall end-diastolic thickness and lower E/A ratio. These results are consistent with electrocardiography parameters which could reflect left ventricular hypertrophy (higher R_V5(6) and R_V5(6) + S_V1(2) parameters, depressed ST segments and tendency to longer Qtc II interval) in 591AT heterozygotes.

Conclusions

Detected variant alleles of CD36 may be associated with features of left ventricular hypertrophy and impaired diastolic function.     

XZ-Ⅱ型轴流血泵的流场分析

血液破坏是目前影响国产心室辅助装置(ventricular assist device,VAD)不能临床应用的主要障碍.方法本文中采用计算机辅助设计(computer-aided design,CAD)工具设计XZ-Ⅱ型轴流血泵,并用计算流体力学(computationalfluid dynamics,CFD)方法进行泵内流场分析对VAD进行血液相容性研究.结果①血泵的压力流量输出可以满足心室辅助的要求;②流场中的最大剪切率出现在叶轮入口的地方,在整个叶轮端面保持了较高的剪切率,而且随着转速升高,剪切率增大,流量增加,剪切率也增大;③在叶轮相对径向流速以较高速度旋转时,在入口附近,流场保持层流状态,接近转子时,出现周向剪切速度,转子和泵壁之间的流场出现了不对称性,中下壁面出现较大波动,在叶轮附近,流场发生剧烈的变化,在靠近轮毂的地方会出现湍流,叶片之间出现较大的分离涡流,在出口导流叶片与叶轮的相接区域,流动出现局部回流,在狭窄的交接区域,出现流动滞止,流体进入导流叶片时,流动方向在此急剧变化会引起流动分离,从而影响了出口流速和流动的稳定性;④叶轮与出口导叶片接触端面压力变化剧烈.结论叶轮内部、叶轮与导叶片连接部分、出口导叶片内部流场不稳定容易形成涡流和流动停滞,容易形成血栓;叶轮与出口导叶片连接端面以及叶轮内部剪切力较高,容易产生溶血.     

DEAD/H BOX 3 (DDX3) helicase binds the RIG‐I adaptor IPS‐1 to up‐regulate IFN‐β‐inducing potential

Retinoic acid‐inducible gene‐I (RIG‐I)‐like receptors (RLR) are members of the DEAD box helicases, and recognize viral RNA in the cytoplasm, leading to IFN‐β induction through the adaptor IFN‐β promoter stimulator‐1 (IPS‐1) (also known as Cardif, mitochondrial antiviral signaling protein or virus‐induced signaling adaptor). Since uninfected cells usually harbor a trace of RIG‐I, other RNA‐binding proteins may participate in assembling viral RNA into the IPS‐1 pathway during the initial response to infection. We searched for proteins coupling with human IPS‐1 by yeast two‐hybrid and identified another DEAD (Asp‐Glu‐Ala‐Asp) box helicase, DDX3 (DEAD/H BOX 3). DDX3 can bind viral RNA to join it in the IPS‐1 complex. Unlike RIG‐I, DDX3 was constitutively expressed in cells, and some fraction of DDX3 is colocalized with IPS‐1 around mitochondria. The 622‐662 a.a DDX3 C‐terminal region (DDX3‐C) directly bound to the IPS‐1 CARD‐like domain, and the whole DDX3 protein also associated with RLR. By reporter assay, DDX3 helped IPS‐1 up‐regulate IFN‐β promoter activation and knockdown of DDX3 by siRNA resulted in reduced IFN‐β induction. This activity was conserved on the DDX3‐C fragment. DDX3 only marginally enhanced IFN‐β promoter activation induced by transfected TANK‐binding kinase 1 (TBK1) or I‐kappa‐B kinase‐ε (IKKε). Forced expression of DDX3 augmented virus‐mediated IFN‐β induction and host cell protection against virus infection. Hence, DDX3 is an antiviral IPS‐1 enhancer.     

介入器械放置与血流影响的仿真分析

心血管介入器械的使用越来越广泛,而综合考虑血流、器械和血管的作用情况,研究器械的放置和设计问题,有助于减少器械诱发的并发症,提高其使用的效果.本文以腔静脉滤器为例,采用计算机建模,有限体积法生成网格,通过计算流场来分析器械与血流的相互作用.结果表明介入器械的结构(如器械的支腿类型、附着方式)和放置对血管及血流有显著的影响,而器械的放置位置也可依据血管流场的情况来进行优化选择.     

CAD基因原核表达载体的构建及表达产物的活性鉴定

目的构建pCool—GST—ICAD／CAD的表达载体，并存大肠杆菌BL21（DE3）中表达具有生物学活性的CAD核酸酶？方法用PCR扩增CAD基因，将扩增产物克隆入pCool—GST—ICAD载体中构建出pCool—GST—ICAD／CAD表达载体。经酶切和电泳鉴定正确后，在大肠杆菌BL21（DE3）中诱导表达，表达产物经亲和层析、离子交换层析及凝胶过滤等方法分离纯化。最后用SDS—PAGE和DNA降解实验进行鉴定。结果构建了pCool—GST—ICAD／CAD原核表达载体，重组载体转化后表达出毫克级水平的GST—ICAD／CAD蛋白复合体。经分离纯化后得到纯度很好的CAD—ICAD篮白复合体，在SDS—PAGE电泳上旱现清晰的两条蛋白带。经DNA降解实验证明纯化所得的CAD蛋白具有非特异性降解DNA的核酸酶作用。结论成功制备了具有生物学活性的CAD核酸酶，为进一步研究细胞凋亡的作用机制提供了有效的制剂。     

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数字印模技术是随着计算机辅助设计与制作（CAD／CAM）技术逐渐发展起来的,与模型扫描相比存在更大的难度,对系统本身的要求更高。常见的口腔数字印模系统包括CEREC蓝光系统（德国Sirona公司）、CERECOmicam系统（德国Sirona公司）、LavaC．O．S．系统（美国3M公司）、iTero系统（美国Cadent／Straumann公司）和E4D系统（美国E4D公司）,这些系统获取印模的方式和软件不同,各有优势。数字印模在效率、精度和舒适性方面与传统印模技术相比具有很大的优势,但需要在牙体预备、干燥隔湿和喷粉取像方面注意操作技巧。     

Fracture risk of lithium-disilicate ceramic inlays: A finite element analysis

Objectives

In the present study, lithium-disilicate ceramic inlays should be analyzed biomechanically according to their thickness and dimension, and it should be clarified as to whether there is a significant relationship between the inlay volume and the induced tensile stress level.

Methods

Using a new parametric CAD modeling procedure, 27 lithium-disilicate ceramic inlays with various parameters of “depth”, “width”, “angle” and restoration volume were generated. These inlays were integrated into the CAD model of a lower molar created from the CT data of an anatomical preparation. The resulting CAD models were, finally, three-dimensionally cross-linked to FEM models. After applying a compressive force of 200 N, Principal Tensile Stresses (PTSs) could be measured in the inlay. The values were subject to statistical analysis afterwards.

Results

The volume of the inlay restorations varied between 35.7 mm³ and 82.5 mm³. The maximum PTS values (n = 10) only showed a slight negative correlation with the inlay volume. The correlation coefficient according to Spearman was −0.082 (p ≤ 0.001). If the highest 1000 PTS values of each inlay were considered (n = 1000), the correlation coefficient was further reduced to +0.068 (p ≤ 0.001). No significant correlation between the inlay volume and the induced PTS level could be detected.

Significance

Under the conditions and limitations of the present FEM study, the inlay volume did not significantly influence the tensile stress level of ceramic inlays. The results may support the thesis that volume-reduced all-ceramic inlays might not have an increased fracture risk. Further studies are needed to confirm this.     

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本文主要介绍了无托槽隐形矫治器的生产工艺流程及现代无托槽隐形矫治技术的临床应用流程。无托槽隐形矫治器的生产工艺流程主要步骤为：扫描硅橡胶印模或石膏模型,从而获得数字化牙列模型,运用计算机辅助设计与制造（CAD／CAM）系统模拟治疗计划并生产加工母模,采用热压成型技术加工隐形矫治器。现代无托槽隐形矫治技术临床应用主要流程有：临床接诊、病例提交、确认模拟矫治方案、生产矫治器、临床配戴矫治器、精细调整,最终完成治疗并保持。     

Coronary Artery Disease in Patients with Ischemic Stroke and TIA

Background and ObjectivesIschemic stroke (IS) and coronary artery disease (CAD) share common risk factors and one may be the harbinger of the other. We aimed to study prevalence of symptomatic and asymptomatic CAD in a cohort of consecutive patients with IS and assess its relationship with intracranial and extracranial large artery cerebrovascular disease (LAD).MethodsAll consecutive eligible IS and Transient Ischemic Attack (TIA) patients were recruited into the study. Both clinically suspected and asymptomatic patients (N = 259) underwent myocardial Stress-rest Gated Technetium-99m (Tc99m) MIBI Myocardial Perfusion SPECT scan performed on a dual head SPECT-CT to estimate evidence of myocardial ischemia.ResultsThree hundred patients completed the study. Forty one patients were previously diagnosed cases of definitive CAD. Twelve patients were clinically suspected to have CAD and 247 patients were asymptomatic. Among these, 12 patients (4.81%) had a positive SPECT. The overall prevalence of CAD was 17.67% (n = 53). Presence of diabetes was an independent predictor of CAD (OR 1.98, 95% CI 1.07-3.67. P .02). No significant association was found between the presence of LAD and CAD in all subgroup comparisons. However, there was a suggestion of higher LAD among patients with known CAD compared with others.ConclusionsCAD is prevalent in patients with ischemic stroke. No definitive relationship was found between CAD and intracranial or extracranial LAD. Population based stratification tools are needed to further assess the need to detect subclinical CAD in patients with stroke.