Antibiotic-lock therapy: a clinical viewpoint

Antibiotic lock therapy (ALT) – instillation of high concentrations of anti-microbial agent with or without anti-coagulant into the lumen of central venous catheters – is considered a valid conservative treatment for catheter-related bloodstream infection (CRBSI) in patients highly dependent on maintaining the catheter. Results from randomized controlled studies have indicated that the effectiveness of ALT is moderate, but recent findings from experimental studies and observational case series point to considerable efficacy and safety of this therapy, which is usually associated with concomitant systemic treatment. In this article, the current knowledge about ALT for patients with CRBSI is reviewed and discussed, with emphasis on existing controversies and the results obtained according to the various uses of the catheters and the etiologies of infection.     

Production of influenza pseudotyped lentiviral particles and their use in influenza research and diagnosis: an update

Pseudotyped viral particles are being used as safe surrogates to mimic the structure and surface of many viruses, including highly pathogenic viruses such as avian influenza H5N1, to investigate biological functions mediated by the envelope proteins derived from these viruses. The first part of this article evaluates and discusses the differences in the production and characterization of influenza pseudoparticles. The second part focuses on the applications that such a flexible tool can provide in modern influenza research, in particular in the fields of drug discovery, molecular biology and diagnosis.     

血液透析患者永久性双腔导管的操作流程改良

目的 探讨永久性双腔导管的操作流程改良对预防透析导管堵管和感染的效果.方法 将透析中心置入长期透析导管的21例患者,随机分对照组10例按照2010版血液净化标准进行导管使用和护理,观察组11例强化双腔导管的细节管理,即整个操作过程不让血液在导管内停留,同时操作环节没有导管口的暴露机会.结果 对照组1 200个导管日,导管不全堵塞71例次,完全堵塞12例次,感染6例次;观察组1 200个导管日,导管不全堵塞11例次,完全堵塞2例次,感染0次,两组比较,差异有统计学意义(P＜0.05,P＜0.01).结论 在导管使用和维护中,注重细节管理,可有效防范导管护理不良事件的发生.     

永久性双腔血液透析导管流量及再循环率的测定

目的了解不同型号永久性双腔血液透析留置导管的实际流量以及不同流量和连接方法下导管再循环率的情况,为永久性双腔导管的临床应用提供实证依据。方法将56例使用永久性双腔血液透析导管的血液透析患者根据留置导管不同分为Perm-cath组(P组)30例,Tal Palindrome TM组(T组)26例,利用Transonic HD02血液透析监护仪进行实际血流量监测。测定正接和反接状态下,泵设流量分别为150、200、250、300、350mL/min时的再循环率。结果无论正接还是反接,两组实际流量均能达到泵设流量的要求;不同泵设流量时正接和反接实际流量比较,差异无统计学意义(均P>0.05)。正接时泵设流量150～350mL/min,两组几乎没有再循环。反接时,不同泵设流量组内再循环率比较,差异无统计学意义(均P>0.05);但各不同泵设流量下,P组再循环率显著高于T组(均P<0.01)。结论两种永久性双腔血液透析留置导管血流量能满足泵设流量需求,正接时都没有再循环;反接时Tal Palindrome TM型再循环率比Permcath型低,两种导管再循环率不随泵设流量的增加而增加。因此,应尽量避免反接导管,必须反接时,可相应提高血流量,以保证透析效果。     

神经生长因子对比格犬年轻恒牙牙髓组织再生的促进作用

目的：建立比格犬年轻恒牙根尖周炎模型,探讨神经生长因子（NGF）对比格犬年轻恒牙牙髓组织再生的影响,阐明其作用机制。方法：选择6只比格犬符合标准的12颗恒牙作为研究对象,将其分为对照组、水凝胶组和水凝胶复合NGF组,每组2只犬4颗恒牙。对照组不建模;水凝胶组建立根尖周炎模型,给予单纯水凝胶处理;水凝胶复合NGF组建立根尖周炎模型,给予NGF复合水凝胶处理。采用HE染色观察各组实验牙组织学变化,测定各组实验牙再生组织长入深度和再生组织面积。结果：比格犬年轻恒牙根尖周炎模型建立成功。对照组牙根管内牙髓组织正常,有成纤维细胞、成牙本质细胞和血管组成;水凝胶组牙根尖部无新形成硬组织,根尖周出现纤维修复;水凝胶复合NGF组牙根管内有新形成的硬组织,可见牙骨质细胞样细胞和牙骨质基质陷窝,根管内可见游离的牙骨质样组织,牙根管内新形成的软组织主要为血管和成纤维细胞。水凝胶复合NGF组牙再生组织长入深度和再生组织面积均高于水凝胶组（t=66.261,P<0.01;t=60.363,P<0.01）。结论： NGF具有促进比格犬年轻恒牙根尖周炎牙髓组织再生的作用。     

免疫介导坏死性肌病的临床和病理特征分析

目的 比较不同肌炎特异性自身抗体(myositis specific antibodies,MSAs)类型的免疫介导坏死性肌病(immune-mediated necrotizing myopathies,IMNM)的临床和病理特征。方法 从中日友好医院2008—2018年住院期间所有行肌肉活检的特发性炎性肌病患者中选取符合以下任一条件的IMNM患者104例:(1)抗信号识别颗粒(signal recognition particle,SRP)抗体阳性;(2)抗3-羟基-3-甲基戊二酰辅酶A 还原酶(3-hydroxy-3-methylglutaryl-coenzyme A reductase,HMGCR)抗体阳性;(3)血清MSAs阴性且病理符合2004年欧洲神经肌肉病中心定义的IMNM病理诊断标准。回顾性收集患者的临床、实验室检查和肌肉病理等信息,比较各组临床及病理特征的差异。结果 所有104例IMNM患者中,肌无力(92.3%)、肌酸激酶升高(92.3%)是IMNM的最常见临床表现,此外,33.7%的IMNM患者合并吞咽困难,46.5%的患者合并间质性肺病(interstitial lung diseases,ILD)。抗HMGCR阳性患者较抗SRP阳性和MSAs阴性患者更容易出现V形疹(30.4% vs. 4.3%和5.9%,P<0.01),抗SRP阳性患者合并ILD发生率高于抗HMGCR阳性和MSAs阴性患者(64.4% vs. 34.8%和29.0%,P<0.01),MSAs阴性患者合并其他结缔组织病更多见(32.4% vs. 8.5%和4.3%,P<0.01)。3组IMNM患者肌肉病理中均可见肌细胞坏死(94.2%)、吞噬(65.4%)和再生(67.3%),肌细胞膜表达主要组织相容性复合物-Ⅰ分子上调(78.8%),肌内膜CD4 ⁺T细胞(68.3%)和CD68 ⁺巨噬细胞(65.7%)浸润。结论 抗SRP抗体阳性、抗HMGCR抗体阳性和MSAs阴性的IMNM患者存在异质性,在临床上开展MSAs检测和肌肉病理检查对区分不同类型的IMNM有指导价值。     

CT引导^125Ⅰ放射粒子联合间质化疗治疗晚期非小细胞肺癌

目的 探讨CT引导^125Ⅰ放射粒子联合间质化疗治疗晚期非小细胞肺癌的临床价值,可行性和安全性。方法 回顾分析经病理证实的晚期非小细胞肺癌患者31例、33个病灶,在CT引导下植入^125Ⅰ放射性粒子,联合植入化疗粒子缓释剂中人氟安,比较治疗前及治疗后6个月肿瘤变化,判定疗效。结果 31例患者33个病灶,6个月后CT复查,CR 6例（19.4%）、PR 21例（67.7%）、NC 3例（9.7%）、PD 1例（3.2%）,有效率（CR＋PR）87.1%。术中4例出现少量气胸,1例肺内少量出血,术后1周内痰中带血丝3例。结论 CT引导^125Ⅰ放射粒子联合间质化疗治疗晚期非小细胞肺癌安全、微创、近期疗效明显。     

Experimental and Numerical Investigation of an Axial Rotary Blood Pump

Left ventricular assist devices (LVADs) have become a standard therapy for patients with severe heart failure. As low blood trauma in LVADs is important for a good clinical outcome, the assessment of the fluid loads inside the pump is critical. More specifically, the flow features on the surfaces where the interaction between blood and artificial material happens is of great importance. Therefore, experimental data for the near‐wall flows in an axial rotary blood pump were collected and directly compared to computational fluid dynamic results. For this, the flow fields based on unsteady Reynolds‐averaged Navier–Stokes simulations‐computational fluid dynamics (URANS‐CFD) of an axial rotary blood pump were calculated and compared with experimental flow data at one typical state of operation in an enlarged model of the pump. The focus was set on the assessment of wall shear stresses (WSS) at the housing wall and rotor gap region by means of the wall‐particle image velocimetry technique, and the visualization of near‐wall flow structures on the inner pump surfaces by a paint erosion method. Additionally, maximum WSS and tip leakage volume flows were measured for 13 different states of operation. Good agreement between CFD and experimental data was found, which includes the location, magnitude, and direction of the maximum and minimum WSS and the presence of recirculation zones on the pump stators. The maximum WSS increased linearly with pressure head. They occurred at the upstream third of the impeller blades and exceeded the critical values with respect to hemolysis. Regions of very high shear stresses and recirculation zones could be identified and were in good agreement with simulations. URANS‐CFD, which is often used for pump performance and blood damage prediction, seems to be, therefore, a valid tool for the assessment of flow fields in axial rotary blood pumps. The magnitude of maximum WSS could be confirmed and were in the order of several hundred Pascal.     

圆柱型Halbach永磁魔环研究进展

受局部饱和和局部退磁效应的影响以及磁材料性能的限制,永磁体的气隙磁场一般难以达到4T。Halbach永磁魔环结构磁材料利用效率高,且能够产生比剩磁更高的静磁场,因而近年来在磁共振成像领域得到了广泛关注。本文针对Halbach永磁魔环的构成形式,介绍了永磁魔环、阵列永磁魔环、永磁双魔环和单边永磁魔环的研究现状,分析了这些魔环结构由于永磁磁块形状、尺寸,永磁材料受温度变化影响,和加工工艺等因素引起的磁场均匀性较差等主要问题,并对圆柱型Halbach永磁魔环在NMR、MRI和便携式分析仪器等方面的应用进行了展望。     

125I粒子条联合胆道支架植入治疗恶性梗阻性黄疸22例疗效分析

目的研究和探讨125I粒子条联合胆道支架植入治疗恶性梗阻性黄疸的临床疗效。方法2011年6月—2013年9月收治恶性梗阻性黄疸患者40例。行胆道支架植入术治疗患者18例,为对照组;采用125I粒子条联合胆道支架植入患者22例,为观察组。两组均采用经皮肝穿刺胆道引流(PTCD)并胆道支架植入。结果观察组与对照组的平均胆道开通时间分别为(8.7±0.7)和(6.2±0.4)个月,两组比较差异有统计学意义(P<0.05)。观察组与对照组术后平均生存时间分别为(11.4±0.8)和(8.7±0.5)个月,生存时间的差异有统计学意义(P<0.05)。术后近期疗效及并发症两组之间的比较无明显差异(P>0.05),但是远期疗效有显著差异(P<0.05)。结论与对照组相比,观察组的术后生存时间及胆道开通时间明显延长,对于125I粒子条联合支架治疗恶性梗阻性黄疸值得进一步临床研究。