Coronary Microembolization with Normal Epicardial Coronary Arteries and No Visible Infarcts on Nitrobluetetrazolium Chloride-Stained Specimens: Evaluation with Cardiac Magnetic Resonance Imaging in a Swine Model

Objective

To assess magnetic resonance imaging (MRI) features of coronary microembolization in a swine model induced by small-sized microemboli, which may cause microinfarcts invisible to the naked eye.

Materials and Methods

Eleven pigs underwent intracoronary injection of small-sized microspheres (42 µm) and catheter coronary angiography was obtained before and after microembolization. Cardiac MRI and measurement of cardiac troponin T (cTnT) were performed at baseline, 6 hours, and 1 week after microembolization. Postmortem evaluation was performed after completion of the imaging studies.

Results

Coronary angiography pre- and post-microembolization revealed normal epicardial coronary arteries. Systolic wall thickening of the microembolized regions decreased significantly from 42.6 ± 2.0% at baseline to 20.3 ± 2.3% at 6 hours and 31.5 ± 2.1% at 1 week after coronary microembolization (p < 0.001 for both). First-pass perfusion defect was visualized at 6 hours but the extent was largely decreased at 1 week. Delayed contrast enhancement MRI (DE-MRI) demonstrated hyperenhancement within the target area at 6 hours but not at 1 week. The microinfarcts on gross specimen stained with nitrobluetetrazolium chloride were invisible to the naked eye and only detectable microscopically. Increased cTnT was observed at 6 hours and 1 week after microembolization.

Conclusion

Coronary microembolization induced by a certain load of small-sized microemboli may result in microinfarcts invisible to the naked eye with normal epicardial coronary arteries. MRI features of myocardial impairment secondary to such microembolization include the decline in left ventricular function and myocardial perfusion at cine and first-pass perfusion imaging, and transient hyperenhancement at DE-MRI.     

The role of costotransverse radical debridement,fusion and postural drainage in the surgical treatment of multisegmental thoracic spinal tuberculosis: a minimum 5-year follow-up

Purpose

We present a retrospective study of patients with multilevel contiguous tuberculous spondylitis of thoracic region that underwent single-stage posterolateral debridement and fusion and following posterior instrumentation.

Methods

From June 2000 to March 2009, 870 consecutive spinal tubercular patients including 36 patients who were diagnosed and treated as multilevel contiguous thoracic spinal tuberculosis in our institution. Apart from five patients being treated conservatively, the 31 cases received surgery by single-stage posterolateral debridement, fusion, following posterior instrumentation and postural drainage. The patients were evaluated based on the Frankel scoring system, kyphotic Cobb angle, and visual analog scale (VAS) pain score.

Results

The mean duration of postoperative follow-up was 79.2 ± 9.9 months (range 62–98 months). Neither mortalities nor any major complications were found. Solid bony fusion was achieved in all patients. No patients with neurological deficit deteriorated postoperatively. According to Frankel scoring system, 7 cases were rated as Grade D, 24 cases as Grade E at last follow-up. The average preoperative Cobb’s angle was 32° (range 21°–39°). The average early postoperative Cobb’s angle was 23° (range 15°–32°). The mean latest postoperative Cobb’s angle was 26° (range 20°–32°), with a small loss of correction at last follow-up. Pre-op VAS was 8.8 ± 0.7 (range 7–10) and final follow-up was 1.8 ± 1.1. There was a significant difference of VAS between preoperation and the final follow-up.

Conclusions

One-stage surgical treatment for multilevel contiguous spinal tuberculosis by posterolateral debridement, fusion, posterior instrumentation can be an effective and feasible treatment method.

     

胸腰椎骨折三种不同内固定方式的疗效比较

目的:对比后路复位内固定治疗胸腰椎骨折中,传统短节段内固定、短节段内固定结合伤椎椎体成形术及经伤椎置钉三种不同内固定方式的临床疗效。方法:回顾性分析我院2010年1月~2014年10月收治的87例胸腰椎单节段骨折患者,其中30例行传统短节段内固定(A组),25例行短节段内固定结合伤椎椎体成形术(B组),32例行经伤椎置钉内固定(C组)。记录患者手术时间、术中出血量,测量手术前后及末次随访时的伤椎前缘高度比值(AVH)、区域后凸角(LKA)等影像学指标,在末次随访时观测CT矢状位及横断位上伤椎骨缺损程度及位置,并进行统计分析。采用汉化Oswestry功能障碍指数(ODI)评估腰背痛症状等。结果:所有病例均获得随访,平均15.5±2.3个月(13~21个月)。三组患者术中出血量无统计学差异(P0.05),但B组的手术时间比A、C两组长,差异具有统计学意义(P0.05);比较三组术前、术后AVH、LKA无统计学差异(P0.05),而末次随访时在AVH、LKA及汉化ODI评分等方面,A组均比B组、C组差(P0.05),B、C两组比较则无统计学差异(P0.05)。末次随访三组患者CT显示伤椎骨缺损在矢状面上主要位于椎体上1/3中部,在横断面上主要位于前柱的中央前缘部。A、B、C三组末次随访伤椎骨缺损程度分别为(18.6±7.3)%、(11.8±4.3)%、(8.4±2.1)%,组间两两比较差异具有显著性(P0.01)。B、C两组无一例出现断钉断棒等现象,而A组则有3例断钉。结论:在后路复位内固定治疗胸腰椎骨折中,与传统短节段内固定相比,结合椎体成形术或经伤椎置钉均能有效维持矫正效果、重建椎体高度及减少内固定并发症,两者临床疗效相当;但经伤椎置钉固定因操作简单、安全,并能进一步有效降低伤椎骨缺损程度,更适合临床推广应用。     

红细胞分布宽度鉴别急性肠系膜缺血诊断价值的系统评价

目的:系统评价红细胞分布宽度(red cell distribution width,RDW)对急性肠系膜缺血(acute mesenteric ischemia,AMI)的诊断价值。方法:在"MEDLINE数据库"、"EMBASE数据库"、"Cochrane系统评价图书馆"、"中国生物医学文献数据库"、"维普中文科技期刊数据库"和"万方数据知识服务平台"系统检索截止2015年8月以前的相关研究,以RDW、AMI和已报道诊断价值的诊断性试验为纳入标准,对所筛选的文献进行纳入和排除,提取数据进行统计学分析。结果:最终纳入4篇文献进行Meta分析,统计学分析显示RDW对AMI诊断价值范围:灵敏度(sensitivity)0.41~0.88;特异度(specificity)0.54~0.92,阳性似然比(positive likelihood ratio)1.49~8.73;阴性似然比(negative likelihood ratio)0.16~0.73;诊断优势比(diagnostic odds ratio)2.59~28.06。结论:纳入文献的研究仍有局限,RDW对AMI的诊断价值还需进一步研究。     

Variants in 9p21 Predicts Severity of Coronary Artery Disease in a Chinese Han Population

Recent genome‐wide association studies identified the common genetic variants in 9p21 were associated with the coronary artery disease (CAD). However, whether this locus could predict the severity of CAD in Chinese Han population is unclear. 499 CAD patients who underwent coronary angiography (CAG) have been enrolled for this study. The single‐nucleotide polymorphisms rs2383207 and rs2383206 in 9p21 were genotyped in 499 CAG cases and 1519 controls in Chinese Han population. The gene dosage of 9p21 was stratified by the degree of vascular lesions and tested for association with the severity of CAD. Rs2383207 and rs2383206 demonstrated significant associations with 2‐vessel and 3‐vessel disease (P = 2.0×10^?3 and 1.9×10^?4, respectively). GG genotypes of rs2383206 occurred higher proportion of left main trunk (LM) disease (P = 6.0×10^?3). GG genotypes of rs2383207 occurred higher proportion of left anterior descending artery disease (LAD) and right CAD (RCA) (P = 2.7×10^?6 and 1.6×10^?4, respectively). The risk allele G of rs2383207 was associated with severity of CAD estimated by the Gensini score (P = 3.6×10^?5). Rs2383207 may strongly influence the development of CAD in Chinese Han population. The gene dosage in 9p21 could predict the severity of CAD.     

Effect of tet methylcytosine dioxygenase 2 on the regulation of transforming growth factor-β1 expression in mesangial cells induced by high glucose

Objective To investigate the role of tet methylcytosine dioxygenase 2 (TET2) in the regulation of transforming growth factor-β1 (TGF-β1) expression in human glomerular mesangial cells induced by high glucose. Methods Cultured human glomerular mesangial cells were divided into normal control group (5.5 mmol/L glucose) and high glucose group (30.0 mmol/L glucose) which was cultured for 12 h to 72 h. The gene expression of TET2 in mesangial cells were inhibited by small molecule chemical called SC1, and which were divided into high glucose group (30.0 mmol/L glucose+DMEM), DMSO group (30.0 mmol/L glucose+0.1%DMSO) and SC1 group (30.0 mmol/L glucose+3 μmol/L SC1). The mRNA and protein expression of TGF-β1, TET1 to 3 and α-smooth muscle actin (α-SMA) was detected by quantitative real-time PCR and Western blotting. Methylation of CpG islands in the regulation region of TGF-β1 was detected by bisulfite sequencing PCR (BSP). The activity of mesangial cell proliferation was assessed by colorimetry of thiazolyl blue (MTT). Results Compared with normal control group, the mRNA and protein expression of TET2 in mesangial cells induced by high glucose was increased significantly in a time-dependent manner (all P＜0.05), but the expression of TET1 and TET3 was not affected. Meanwhile methylation rate of 4 CG sites from 24 h to 72 h were decreased in the first exon of TGF-β1 (P＜0.01), but not in the promoter. Compared with high glucose group, when the expression of TET2 was inhibited by SC1, the methylation rate of TGF-β1 was recovered evidently (P＜0.05), the mRNA and protein expression of TGF-β1 and α-SMA was suppressed, and the proliferation of mesangial cells was decreased (all P＜0.05). Conclusions Demethylation of the CpG island mediated by TET2 may play an important role in the expression of TGF-β1 and mesangial cell phenotype transformation induced by high glucose.     

ER、PR、HER-2、Ki-67与乳腺癌新辅助化疗疗效相关性分析

目的  探讨雌激素受体（ER）、孕激素受体（PR）、人表皮生长因子受体2（HER-2）、Ki67抗原（Ki-67）与乳腺癌新辅助化疗疗效相关性分析。方法  采用免疫组织化学方法检测81例乳腺癌新辅助化疗前后ER、PR、HER-2、Ki-67的表达情况,并评估其与乳腺癌新辅助化疗有效率的关系。结果  81例患者中临床RR79％,术后pCR（9.9％）,tpCR（6.2％）。达到pCR+tpCR率,（ER阴性）23.0%>（ER阳性）12.7%,（PR阴性）28.6%>（PR阳性）9.4%;ER、PR、HER-2及Ki67等与新辅助化疗疗效之间差异无统计学意义。新辅助化疗前后ER、PR、HER-2的状态改变不明显,差异无统计学意义（P >0.05）,而Ki67的表达数量有统计学意义（P <0.05）,其降低了Ki67的表达水平。结论  乳腺癌新辅助化疗可有效控制肿瘤,ER或PR阴性者较阳性者可获得更高的pCR+tpCR率,Ki67可作为化疗药物敏感性和耐药性的预测指标。

     

鼻咽癌放疗抵抗的分子机制研究进展

鼻咽癌（NPC）是我国南方及东南亚地区最常见的恶性肿瘤之一,其发病率和死亡率均居头颈恶性肿瘤之首。放射治疗（简称放疗）是NPC的首选治疗方式,但放疗抵抗严重地影响NPC的放疗效果,所以开展NPC放疗抵抗的分子机制研究,以降低NPC放疗抵抗性、增强其放疗敏感性成为目前医学工作者研究的重点。近年来,学者们从基因组学、蛋白质组学和micro RNA组学等方面对NPC放疗抵抗产生的原因及分子机制进行大量研究,该文就其研究进展予以综述。