3.0T MR IDEAL序列成像应用于腰骶神经根受压的初步临床研究

目的探讨IDEAL技术在腰椎间盘突出症中显示腰骶神经受压的临床应用价值。方法将明显腰腿痛并腰椎间盘突出的患者40例作为观察组,正常志愿者10例作为对照组,行腰骶神经根IDEAL序列冠状位薄层扫描和常规扫描,所有图像均经最大信号强度投影(MIP)和曲面重建(CPR)后处理,观察腰骶神经根的受压特点及其与突出椎间盘与邻近组织的关系。结果观察组40例中有92组腰椎间盘不同程度的疝出,而由此引起的神经根受压共81组,其中神经根侧隐窝段受压的概率显著大于椎管内段,但是任何部位的神经根受压好发生于同侧还是双侧受压并没有统计学意义(P=0.338)。另有4组神经根受压由增厚的黄韧带或骨质增生引起;有6组由神经根鞘囊肿引起。受压神经根的影像学表现为:(1)神经根局部缺损样压迹;(2)走行的改变;(3)形态的改变,包括局部肿胀,甚至截断样改变;(4)与邻近组织局部粘连,边界不清,边缘模糊;(5)局部脑脊髓间隙变窄或消失。结论 IDEAL序列能直观显示腰骶神经根与邻近结构的关系及受压特点,能够对神经根受压作出准确的定位和受压程度评估,对判断腰骶神经受压、损伤等具有一定的临床诊断价值,也能为临床早期选择正确的治疗方案及疗效观察提供可靠的参考依据。     

128层多排螺旋CT前门控与非门控技术在小儿先天性心脏病中的应用对比

目的探讨128层多排螺旋CT(MDCT)前门控技术在小儿先天性心脏病检查的应用价值。方法分别采用前瞻性心电门控技术与螺旋非门控技术对2组各15例年龄、体质量相近的先天性心脏病患儿行128层MDCT心脏扫描。计算并比较2组的有效辐射剂量(ED)。对2组扫描显示不同解剖结构的图像质量进行主观评价并比较。结果门控组ED低于非门控组(P<0.05)。室间隔、房间隔、升主动脉、肺动脉主干的图像质量门控组高于非门控组(P<0.05);主动脉弓降部与两侧肺动脉干图像质量2组差异无统计学意义。结论对小儿先天性心脏病患者,应用前门控技术行128层MDCT心脏扫描可减低辐射剂量并提高图像质量。     

3.0 T磁共振T2弛豫时间图技术在评估兔坐骨神经放射性损伤的价值

目的探讨使用磁共振T₂弛豫时间图（T₂ mapping）技术评估兔坐骨神经放射性损伤的可行性和准确性。方法选取21只新西兰大白兔,随机选取一侧后肢坐骨神经行单次立体定向照射,照射剂量35 Gy,照射中心位于神经层面距腓肠肌后缘3 cm,照射野直径1 cm,照射体积约0.79 cm³,对侧为对照侧。所有兔于照射前、照射后1 d、1个月、2个月、3个月、4个月评价肢体功能变化,并行T₂多回波及T₂WI/SPIR序列扫描。扫描完成后于上述各时间点随机处死2只兔,取照射段坐骨神经行电镜检查。结果照射后1 d,照射段神经T₂值明显升高,神经肿胀、T₂WI/SPIR信号稍增高;照射后1个月T₂值较1 d降低,接近正常水平,T₂WI/SPIR上信号未见升高;照射后2个月起T₂值进行性升高,并至4个月达高峰,T₂WI/SPIR上2个月起神经及周围肌间隙出现小片长T₂信号影,3、4个月异常信号逐渐加重并出现条索状短T₂信号影。结论 T₂值能较好地反映周围神经放射性损伤的急性改变,但它对于评价放射性损伤时神经的细微改变可能并不敏感。     

原代大鼠雪旺细胞在聚甲基丙烯酸甲酯电纺纳米纤维支架上的生长

目的 探讨原代大鼠雪旺细胞(SCs)在不同拓扑结构的聚甲基丙烯酸甲酯(PMMA)电纺纳米纤维上生长的特点,为后续在体研究提供基础.方法 构建具有随机或有序拓扑结构的PMMA电纺纳米纤维,并测定其生物相容性;利用PMMA薄膜组作为对照,利用慢病毒载体转染绿色荧光蛋白基因作为显色手段,分析SCs在随机及有序纤维支架上的细胞形态和生长方向,以及胞体及突起与纤维结构的依存关系. 结果 构建的PMMA电纺纳米纤维具有良好的生物相容性,SCs在随机及有序电纺纤维上均能顺利贴壁并生长;电纺纤维的拓扑结构能够影响SCs的细胞形态,与在PMMA薄膜及随机电纺纤维上相比,在有序纤维系统上的SCs能够形成更长且与纤维延伸方向一致的细胞突起(P＜0.01).相比随机电纺纤维,有序纳米纤维对原代SCs的生长更具引导作用. 结论 PMMA有序电纺纳米纤维具有作为神经损伤后植入性SCs支架的潜力.     

Stent Compression in Iliac Vein Compression Syndrome Associated with Acute Ilio-Femoral Deep Vein Thrombosis

ObjectiveThis study was conducted to evaluate stent compression in iliac vein compression syndrome (IVCS) and to identify its association with stent patency.ResultsAll of the stents used were laser-cut nitinol stents. The proportion of limbs showing significant stent compression was 33%. Fifty-six percent of limbs in the significant stent compression group developed stent occlusion. On the other hand, only 9% of limbs in the insignificant stent compression group developed stent occlusion. Significant stent compression was inversely correlated with stent patency (p < 0.001). The median patency period evaluated with Kaplan-Meier analysis was 20.0 months for patients with significant stent compression. Other factors including gender, age, and type of stent were not correlated with stent patency. Significant stent compression occurred most frequently (87.5%) at the upper end of the stent (ilio-caval junction).ConclusionSignificant compression of nitinol stents placed in IVCS highly affects stent patency. Therefore, in order to prevent stent compression in IVCS, nitinol stents with higher radial resistive force may be required.     

Cyclosporine-induced renal injury induces toll-like receptor and maturation of dendritic cells

BACKGROUND: The toll-like receptor (TLR) is stimulated by not only pathogen-associated molecular patterns but also endogenous TLR ligands provided by injured cells. The influence of cyclosporine A (CsA)-induced renal injury on TLR expression and subsequent signaling pathway was evaluated. METHODS: Induction of chronic CsA nephropathy was made by administering CsA (15 mg/kg/day) for 28 days in rats. The TLR2 and TLR4 mRNA and protein expression, TLR-signaling pathway (MYD88, NF-kappaB and AP-1), putative TLR ligand (heat shock protein 70 [HSP70]), and maturation of dendritic cells were evaluated in CsA-treated rat kidneys. RESULTS: Long-term CsA treatment upregulated TLR2 and TLR4 mRNA and protein expression on renal tubular cells, and these were accompanied by increased MYD88, NF-kappaB and AP-1 expression. Putative TLR ligand (HSP70) was also significantly increased in CsA-treated rat kidney compared with vehicle-treated rat kidney. CsA-treatment increased expression of TNF-alpha mRNA, the number of dendritic cells, and expression of MHC class II antigen. Double-labeling of markers of dendritic cells and MHC class II antigen revealed that matured dendritic cells increased in CsA-treated rat kidney. CONCLUSIONS: CsA-induced renal injury stimulates components of innate immunity, and this finding suggests close association between CsA-induced renal injury and activation of innate immunity.     

Reduced capacity of whole blood leucocytes to express tumour necrosis factor-alpha and interleukin-10 following major orthopaedic surgery

BACKGROUND: Severe trauma is a challenge to the immune response and may cause reduced immune capacity. As a marker of decreased cellular activity, studies with ex vivo lipopolysaccharide (LPS) stimulation of whole blood or isolated mononuclear cells from injured patients have revealed reduced production of inflammatory cytokines. To gain further insight into immune alterations in orthopaedic surgery, we studied LPS-induced tumour necrosis factor (TNF)-alpha and interleukin (IL)-10 in whole blood of patients during peri- and postoperative phases of total hip replacement. METHODS: Four females and 3 males undergoing elective total hip replacement were included in the study. Ex vivo LPS-induced TNF-alpha and IL-10 were measured in a whole blood assay before, during and at 1 and 6 days after operation. In addition, the counts of white blood cells were determined. RESULTS: During the operation, there were significant reductions in the number of monocytes, but at day 1 and 6 after surgery, there were significant increases as compared to the levels before surgery. The capacity of whole blood to express TNF-alpha and IL-10 did not change significantly during the operation and the following postoperative day. At day 6, however, there were significant reductions in expression of both TNF-alpha and IL-10 as compared to the levels before the operation. In relation to the values of monocytes, there was a significant reduction in the expression of TNF-alpha also at day 1 after operation. CONCLUSION: Our data indicate that in the course of at least 6 days after a major orthopaedic trauma, there is suppression of the whole blood capacity to express the inflammatory cytokine TNF-alpha and the anti-inflammatory cytokine IL-10 when exposed to LPS. During this time, then, the patient is particular susceptible to septic complications.     

Large-Scale Proteomics and Phosphoproteomics of Urinary Exosomes

Normal human urine contains large numbers of exosomes, which are 40- to 100-nm vesicles that originate as the internal vesicles in multivesicular bodies from every renal epithelial cell type facing the urinary space. Here, we used LC-MS/MS to profile the proteome of human urinary exosomes. Overall, the analysis identified 1132 proteins unambiguously, including 177 that are represented on the Online Mendelian Inheritance in Man database of disease-related genes, suggesting that exosome analysis is a potential approach to discover urinary biomarkers. We extended the proteomic analysis to phosphoproteomic profiling using neutral loss scanning, and this yielded multiple novel phosphorylation sites, including serine-811 in the thiazide-sensitive Na-Cl co-transporter, NCC. To demonstrate the potential use of exosome analysis to identify a genetic renal disease, we carried out immunoblotting of exosomes from urine samples of patients with a clinical diagnosis of Bartter syndrome type I, showing an absence of the sodium-potassium-chloride co-transporter 2, NKCC2. The proteomic data are publicly accessible at http://dir.nhlbi.nih.gov/papers/lkem/exosome/.Urinary exosomes are small extracellular vesicles (<100 nm in diameter) that originate from the internal vesicles of multivesicular bodies (MVB) in renal epithelial cells, including glomerular podocytes, renal tubule cells, and the cells lining the urinary drainage system.¹ Exosomes are released into the urine when the outer membrane of the MVB fuses with the apical plasma membrane of the epithelial cell.Exosomes can be recovered from the urine by differential centrifugation as a low-density membrane fraction. Exosome isolation can result in marked enrichment of low-abundance urinary proteins that have potential pathophysiologic significance. As a consequence, we and others have been working to define optimal conditions for their isolation and purification as a prelude to their use in biomarker discovery studies.^1–3In this study, we thoroughly expanded the known proteome of human urinary exosomes by using a highly sensitive LC-MS/MS system, improved software for identification of peptide ions and a more elaborate data analysis strategy than in our previous study. In addition, we used a neutral loss scanning approach⁴ to investigate the phosphoproteome of human urinary exosomes. The study identified 1412 proteins including 14 phosphoproteins in human urinary exosomes. Overall, there are 177 proteins that are associated with diseases as judged by their presence on the Online Mendelian Inheritance in Man (OMIM) database, 34 of which are known to be associated with renal diseases. The potential clinical usefulness of urinary exosomes was demonstrated using the well-defined renal tubulopathy, Bartter syndrome type I, as an example. The rich information from the proteomic analysis also provides further insight into the biogenesis of urinary exosomes.     

阿片类药物耐受机制的研究进展

以吗啡为代表的阿片类药物在治疗慢性疼痛病人时,可使机体对药物产生耐受与依赖。阿片类药物耐受性的形成涉及复杂的分子生物学机制。在受体水平,主要涉及u阿片受体;受体后机制则主要体现在神经细胞内信号转导途径的变化。