彩色室壁动力技术小剂量多巴酚丁胺负荷试验检测冬眠心肌与病理学检查对比的实验研究

目的: 探讨彩色室壁动力技术(CK)小剂量多巴酚丁胺超声心动图负荷试验(CK-DSE) 检测冬眠心肌(HM)的价值.材料和方法: 22只犬结扎冠状动脉造成实验性心肌缺血损伤的动物模型.应用CK-DSE检测动物模型的心肌梗塞区心内膜运动幅度/非梗塞区心内膜运动幅度比值(AMI/ANMI),与病理组织切片显示冬眠心肌面积/梗塞区总面积的比值(ATAM/ATIM)进行对比分析.结果: 本实验成功地建立11只实验性心肌缺血损伤的动物模型,CK-DSE检测冬眠心肌的敏感性、特异性和准确性分别为90%、80%和83%.CK-DSE检测AMI/ANMI比值,与ATAM/ATIM具有较好的相关关系(r=0.75).结论: CK-DSE能准确地检出心肌梗死后存活的冬眠心肌,是定量检测梗塞区内冬眠心肌的较好方法.     

彩色多普勒血流会聚法定量诊断二尖瓣狭窄的研究

本研究应用Ｍ型彩色多普勒血流会聚法、二维彩色多普勒血流会聚法测量２１例以二尖瓣狭窄为主的风心病患者二尖瓣狭窄瓣口面积，并分别与二维超声直接测面积法及多普勒超声压力减半时间法所测二尖瓣口面积相比较。结果表明，Ｍ型彩色多普勒血流会聚法与二维彩色多普勒血流会聚法在检测二尖瓣狭窄瓣口面积方面基本可靠，但两者的准确性无显著差异。本文初步分析了Ｍ型彩色多普勒血流会聚法及二维彩色多普载血流会聚法测量二尖瓣狭窄瓣口面积的优缺点及临床价值。     

MicroRNA‐146a contributes to abnormal activation of the type I interferon pathway in human lupus by targeting the key signaling proteins

Objective

MicroRNA have recently been identified as regulators that modulate target gene expression and are involved in shaping the immune response. This study was undertaken to investigate the contribution of microRNA‐146a (miR‐146a), which was identified in the pilot expression profiling step, to the pathogenesis of systemic lupus erythematosus (SLE).

Methods

TaqMan microRNA assays of peripheral blood leukocytes were used for comparison of expression levels of microRNA between SLE patients and controls. Transfection and stimulation of cultured cells were conducted to determine the biologic function of miR‐146a. Bioinformatics prediction and validation by reporter gene assay and Western blotting were performed to identify miR‐146a targets.

Results

Profiling of 156 miRNA in SLE patients revealed the differential expression of multiple microRNA, including miR‐146a, a negative regulator of innate immunity. Further analysis showed that underexpression of miR‐146a negatively correlated with clinical disease activity and with interferon (IFN) scores in patients with SLE. Of note, overexpression of miR‐146a reduced, while inhibition of endogenous miR‐146a increased, the induction of type I IFNs in peripheral blood mononuclear cells (PBMCs). Furthermore, miR‐146a directly repressed the transactivation downstream of type I IFN. At the molecular level, miR‐146a could target IFN regulatory factor 5 and STAT‐1. More importantly, introduction of miR‐146a into the patients' PBMCs alleviated the coordinate activation of the type I IFN pathway.

Conclusion

The microRNA miR‐146a is a negative regulator of the IFN pathway. Underexpression of miR‐146a contributes to alterations in the type I IFN pathway in lupus patients by targeting the key signaling proteins. The findings provide potential novel strategies for therapeutic intervention.

     

VFM评价正常成人左室心腔血流流场运动状态的初步研究

目的:运用VFM( Vector Flow Mapping)成像探讨正常成人左心室腔内收缩期血流流场特征.方法:健康成人志愿者40例(男22例,女18例),二维超声取心尖三腔观左室腔彩色血流信息动态图像存贮并脱机分析,将取样线分别置于左室腔基底段、中尖段和心尖段,获取心动周期内经取样线部位左室腔血流时间速度积分(Time-Flow curve, TF)变化曲线,记录基底段、中间段及心尖段收缩早期速度时间积分(ES-TF)、收缩中期速度时间积分(MS-TF)、收缩晚期速度时间积分(LS-TF).观察收缩期血流流场特征,观察涡流出现时间,测量涡流直径(横径Dx,)及涡流的最大向量速度(Vmax).结果:正常人左室心腔血流流场呈规则变化,收缩早期二尖瓣前叶下方可见涡流显示,收缩中期及晚期涡流消失.收缩早、中、晚期,血流时间速度积分测值由心尖段经中间段至基底段逐渐递增,差异均有统计学意义(P<0.05).收缩早期涡流直径约为(25.74±7.32)mm, 涡流最大向量速度均背离探头,大小为(38.31±14.25)cm/s,朝向探头速度大小为(11.42±6.28) cm/s.结论:应用VFM技术可清晰显示左室心腔内血流流场状态,左室腔血流速度积分测值可直观反应心腔内血流动力学变化.     

Left ventricular apical aneurysm associated with normal coronary arteries following cardiac surgery: Echocardiographic features and differential diagnosis

Left ventricular aneurysms mainly occur in patients with transmural myocardial infarction caused by left anterior descending coronary artery occlusion. Left ventricular apical aneurysm is rarely found in patients with normal coronary arteriograms, and even rarer in these patients following cardiac operations. We analyzed 37 patients with postoperative left ventricular apical aneurysm, including 1 case from our hospital and 36 cases from the literature; 23 cases (62%) had left ventricular apical true aneurysms and 14 cases (38%) had left ventricular apical pseudoaneurysms, all confirmed at surgery and/or angiography. All cases, with the exception of one, had previously undergone cardiac surgery under cardiopulmonary bypass with apical venting. Although left ventriculography is generally regarded as the gold standard for diagnosis of ventricular aneurysm, echocardiography is an accurate and sensitive method in the evaluation of left ventricular apical aneurysm. Differential diagnosis of left ventricular apical aneurysm includes takotsubo cardiomyopathy, post transapical approach for transcatheter aortic valve implantation, and left ventricular diverticulum.     

室间隔缺损修补术后残余分流自然愈合的彩色多普勒超声心动图观察

本文报道２例室间隔缺损修补术后残余分流但以后自然愈合的患者，１例室间隔缺损患者于修补术后１０天彩色多普勒超声心动图检查时见残余分流，在术后１２周复查时发现残余分流自然消失。另１例为室间隔缺损合并房间隔缺损患者，术后第２天有较重的血红蛋白尿，彩色多普勒超声心动图检查时发现心室水平及左室与右房间的残余分流而行再次修补术。第二次术后１５天彩色多普勒超声心动图检查时仍存在左室与右房间的残余分流。继续追踪观察于再次术后７周原残余分流消失，自然愈合。室间隔缺损术后可因修补不完善，补片与空间隔间缝线撕裂，或补片与室间隔间存在较窄的缝隙而出现残余分流。较小的残余分流可因补片与室间隔交接处形成血栓、缝线周围纤维化等因素而自然愈合，患者无需进行再治疗。彩色多普勒超声心动图可较敏感地发现室间隔缺损术后残余分流，并可追踪观察残余分流的自然愈合，因而对其预后判断具有重要价值。     

Right ventricular regional and global systolic function is diminished in patients with pulmonary arterial hypertension: a 2-dimensional ultrasound speckle tracking echocardiography study

The purpose of the study is to evaluate right ventricular (RV) regional and global systolic function in patients with pulmonary arterial hypertension (PAH) by 2-dimensional ultrasound speckle tracking echocardiography (STE) and explore the impact of pulmonary artery systolic pressure (PASP) and pulmonary vascular resistance (PVR) on RV systolic function. 42 patients with PAH and 31 healthy controls were included in this study. RV longitudinal peak systolic strain (LS) and strain rate (LSRs) were measured at the basal, mid and apical segments of the RV free wall and septum by STE. RV global longitudinal peak systolic strain (GLS) and strain rate (GLSRs) were also measured by STE. RV ejection fraction (EF) was determinated by cardiac magnetic resonance (CMR) imaging. LS and LSRs of RV 6 segments were significantly reduced in patients with PAH compared with controls. RV GLS and GLSRs were lower in patients with varying degrees of PAH than controls. Furthermore, RV GLS were most altered in patients with severe PAH compared with mild PAH. PVR was correlated with RV GLS and GLSRs (r ₁  = ?0.549; r ₂  = ?0.466, respectively, P < 0.05). Similarly, there was correlation between PASP and RV GLS and GLSRs (r ₁  = ?0.551; r ₂  = ?0.425, respectively, P < 0.05). GLS and GLSRs were correlated with CMR-derived RVEF. (r ₁  = 0.693; r ₂  = 0.560, respectively, P < 0.05). STE can identify impaired RV regional and global systolic function in patients with PAH. STE-derived strain and strain rate can be used as novel indices for RV function assessment from 2-dimensional echocardiographic images.     

罗哌卡因在老年患者全髋关节置换术中髋关节囊周围神经阻滞的半数有效浓度

目的 测定全麻联合髋关节囊周围神经（PENG）阻滞用于全髋关节置换术老年患者的罗哌卡因半数有效浓度（EC₅₀）。

方法 选择择期行全髋关节置换术的老年患者36例,男20例,女16例,年龄65～80岁,BMI 18～30 kg/m²,ASA Ⅱ或Ⅲ级。在超声引导下行PENG阻滞,设定罗哌卡因容量为20 ml,浓度由序贯法确定,初始浓度为0.375%,若神经阻滞20 min后,静息NRS评分较阻滞前下降≥2分且活动时NRS评分较阻滞前下降≥3分时,则视为阻滞成功,反之则视为失败,阻滞失败则下1例患者提高1个浓度梯度,阻滞成功则下1例患者降低1个浓度梯度,相邻浓度比值为1.0∶1.2,直至出现7个拐点。采用Probit概率法计算罗哌卡因的EC₅₀及其 95%可信区间（CI）。记录PENG阻滞前（阻滞前）、阻滞后20 min和术后2、6、12、24 h静息和活动（被动抬髋15°）时NRS评分,术后穿刺部位感染、血肿、神经损伤、局麻药中毒、恶心、呕吐、头晕等发生情况。

结果 罗哌卡因用于老年患者全髋关节置换术前行PENG阻滞的EC₅₀为0.185%（95%CI 0.154%～0.213%）。无一例患者穿刺部位感染、血肿、神经损伤、局麻药中毒并发症。

结论 罗哌卡因用于老年患者全髋关节置换术中PENG阻滞的EC₅₀为0.185%（95%CI 0.154%～0.213%）。     

补阳还五汤联合依达拉奉对脑缺血再灌注后神经细胞凋亡及Bcl-2和Bax表达的影响

目的 研究补阳还五汤联合依达拉奉对小鼠脑缺血再灌注损伤后神经细胞凋亡及凋亡相关蛋白表达的影响。方法 60 只小鼠随机分假手术组（sham）,模型组（I/R）,补阳还五汤组（BYHWD）,依达拉奉组（ED）,补阳还五汤+依达拉奉组（BYHWD+ED）,每组再分2个亚组：1 d组和7 d 组。采用改良线栓法制作小鼠大脑中动脉缺血再灌注模型,分别给药。TUNEL法观察神经细胞凋亡率;进一步Western bolt检测大脑皮质缺血区bcl-2 和 bax的蛋白的定量表达。结果 补阳还五汤+依达拉奉组较其他组能更明显地降低神经细胞凋亡指数(P<0.01),且较其他组可更明显地升高凋亡相关蛋白bcl-2的表达和下调bax的表达 (P<0．05)。结论 补阳还五汤与依达拉奉联用能降低脑缺血再灌注损伤后小鼠脑组织细胞中促凋亡蛋白bax的表达,增加具有神经元保护作用的抑凋亡蛋白bcl-2的表达,从而抑制神经细胞凋亡,加速神经功能的恢复,协同发挥脑保护作用。