Underlying mechanisms of saphenous vein graft stenosis after coronary artery bypass caused by clipping of the side branches: an experimental study

BackgroundSaphenous veins are regular bypass conduits selected in non-left anterior descending artery (LAD) coronary artery bypass graft (CABG) surgery. Despite the technical errors, acute thrombosis, intimal hyperplasia and arteriosclerosis which could lead to saphenous vein graft (SVG) failure, the metal-clipping-related SVG failure is unique and rare. This study was conducted to investigate the clinical and underlying mechanisms of the metal-clipping-related SVG failure.MethodsWe collected 6 typical cases of the metal-clipping-related SVG failure in 41 patients who were diagnosed graft stenosis by coronary angiograph after CABG in the Department of Cardiology, Beijing Anzhen Hospital, from January 2020 to September 2021. Furthermore, we built an in vitro model to verify the identical intravascular ultrasound (IVUS) pattern of metal clip.ResultsThere were 6 in 41 cases of SVG stenosis caused by clipping of the side branches. We found that the stenosis of SVG caused by metal clipping mostly occurred at the corner and multipole clipping points. In this situation, great resistance could be felt when pushing the instruments through the stenosis and crystallized cholesterol was rarely caught by the distal protection device. We verified the similar IVUS pattern of metal clip at the side-branches of SVG in vitro.ConclusionsThe metal-clipping-related stenosis may lead to SVG failure. The stenosis of SVG caused by metal clipping mostly occurred at the corner and multipole clipping points. IVUS showed great modality for clarification.     

Deep Cryogenic Treatment Characteristics of a Deformation-Processed Cu-Ni-Co-Si Alloy

This paper investigated the influence of deep cryogenic treatments (DCT) on the tensile strength, elongation to fracture and conductivity of a deformation-processed Cu-Ni-Co-Si alloy. The tensile properties were measured using a mechanical testing machine. The conductivity was evaluated using a low-resistance tester. The microstructure and precipitated phases were analyzed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), an energy dispersive spectrometer (EDS) and an X-ray diffractometer (XRD). The tensile strength, elongation to fracture and conductivity of the Cu-1.34Ni-1.02Co-0.61Si alloy before and after cold rolling at 47% reduction increased with increasing DCT time and tended to be stable at about 36 h. The microstructure became more uniform after the DCT. The grain size was refined and was smallest after DCT for 48 h. The DCT promoted the precipitation of the solid solution elements Ni, Co and Si from the Cu matrix to form many fine and evenly distributed 20–70 nm spherical second-phase particles in the grains and grain boundaries.     

Emergence of Klebsiella pneumoniae carbapenemase-producing Proteus mirabilis in Hangzhou, China

Background Carbapenems are used to treat severe infections caused by multi-drug-resistant organisms, however, the emergence of carbapenem-resistant bacterial isolates is becoming an increasing therapeutic challenge. Since the first Klebsiella （K.） pneumoniae carbapenemase （KPC）-producing K. pneumoniae was reported in 2001, KPC-producing isolates have been found increasingly, specially in Enterobacteriaceae. The aim of this study was to characterize the mechanisms of a carbapenem-resistant Proteus （P.） mirabilis. Methods A carbapenem-resistant P. mirabilis isolate was recovered from pleural drainage fluid of a patient admitted to surgical intensive care unit. Antimicrobial susceptibility testing of the isolate was performed by disk diffusion according to Clinical and Laboratory Standards Institute guidelines, and subsequent minimal inhibitory concentrations were determined with the E-test. Amplification of the blaKPC gene generated a positive band and the PCR products were sequenced subsequently. The plasmid of the isolate was extracted and was successfully transformed into Escherichia （E.） coli DH5a. Results The P. mirabilis isolate was resistant to all detected antimicrobial agents except tigecycline. KPC-2 was confirmed by DNA sequence analysis. The transformant E. coil was resistant to carbapenems. Further study demonstrated that upstream and downstream regions of b/aKPC-2 were identical to that observed in K. pneumoniae submitted to GenBank from China in 2007. Conclusion Carbapenem resistance in the P. mirabilis isolate in this study is mainly due to production of KPC-2.     

人体内肺癌细胞Ku80蛋白含量与顺铂化疗敏感性的关系研究

目的探讨患者体内肺癌细胞Ku80蛋白含量与其对顺铂敏感性的相关性。方法收集肺癌患者胸腔积液中的肺癌细胞进行体外原代培养,通过传代进行纯化和扩增后进行实验。体外药敏试验采用CCK-8法测定肺癌细胞对顺铂的敏感性,获得各样本的半数抑制浓度(IC50)。利用Western blot法测定各样本细胞内Ku80蛋白含量。分析Ku80蛋白含量与顺铂敏感性的相关性。结果非小细胞肺癌(NSCLC)组IC50为(4.40±3.39)mg/L,小细胞肺癌(SCLC)组IC50为(1.02±0.54)mg/L,二者比较差异有统计学意义(P0.001)。NSCLC组Ku80蛋白相对含量为0.80±0.45,而SCLC组为0.48±0.25,二组之间比较差异有统计学意义(P0.05)。通过相关性分析得到肺癌患者Ku80含量与IC50呈正相关(r=0.618,P0.001)。结论 NSCLC患者Ku80基因表达高于SCLC患者,可能与NSCLC对化疗敏感性差有关。肺癌细胞Ku80蛋白含量与其对顺铂敏感性呈负相关。Ku80蛋白含量可作为预测肺癌患者以铂类为基础的化疗敏感性的候选指标。     

超声引导与触脉结合在桡动脉穿刺置管中的应用

目的 评估超声引导结合传统触脉定位行桡动脉穿刺置管的临床效果.方法 选取解放军第四一一医院准备择期手术患者60例,ASA Ⅰ或Ⅱ级,年龄32 ～ 87岁,采用数字表法随机分为U、C2组,每组30人.U组:采用传统触脉定位结合超声引导下穿刺置管;C组:采用传统触脉盲探法穿刺置管.记录2组患者定位及准备时间、置管成功时间、一次成功率、总成功率、穿刺次数、失败率及血肿并发症发生率.结果 与传统触脉定位法相比,传统触脉定位结合超声引导法置管成功时间显著缩短(P＜0.01),一次成功率显著提高(P＜0.01),穿刺次数显著减少(P＜0.01).结论 超声引导与触脉结合下行桡动脉穿刺置管,穿刺时间短,一次成功率高,并发症发生率低,安全可靠.     

顶空-气相色谱法测定人参皂苷Rd原料中残留物的含量

目的 :建立人参皂苷Rd原料中溶剂和树脂残留物的测定方法。方法 :采用顶空进样 毛细管气相色谱法 ,色谱柱为CP Sil 8石英毛细管柱 (30m× 0 5 3mm ,5 μm) ;柱温 :5 0℃维持 5min ,以每分钟 15℃升温至16 0℃ ,维持 2min ;检测器 :FID ,温度 :2 80℃。用外标法测定人参皂苷Rd原料中溶剂和树脂残留物。结果 :建立的色谱方法在所考察的浓度范围内线性关系良好 ,各溶剂回收率符合要求。结论 :本实验建立的色谱方法适用于人参皂苷Rd原料中溶剂和树脂残留物的检测。     

小儿导水管阻塞性脑积水32例治疗体会

目的　评价脑室一腹腔分流术（ＶＰＳ）对小儿导水管阻塞性脑积水的疗效。方法　回顾性总结了３２ 例小儿导水管阻塞性脑积水的临床表现、诊断、治疗与疗效。结果　３２ 例中恢复良好１４ 例,好转１２ 例,有效６ 例。结论　采用ＶＰＳ治疗小儿导水管阻塞性脑积水是一种安全有效的治疗方法。     

血浆BNP水平对老年COPD患者肺动脉高压及预后的评估意义

目的通过比较老年COPD患者与非COPD患者血浆BNP水平、肺动脉压力、预后间的差别及相关指标间的联系,探讨血浆BNP水平对相关指标的评估作用。方法回顾性分析24例2011年1月～2012年1月共24例60岁以上老年COPD患者血浆BNP水平、肺动脉压力等,并与52例非COPD患者比较,分析其差别并确定各指标间相互联系。结果 COPD患者的肺动脉压力(39.88mmHg)明显高于非COPD患者(12mmHg),同时COPD患者的血浆BNP水平(671.83ng/L)亦明显高于非COPD患者(98.35ng/L)(P<0.01),且血浆BNP水平与肺动脉压力间存在正相关关系(rs=0.508,P=0.011),但尚不能评估患者预后。结论血浆BNP水平是反映患者肺动脉压力水平的良好指标,对于临床肺动脉压监测及病情评估有良好意义。     

我国桑属（Morus L．）药用植物资源化学研究进展

我国已有5000年栽桑养蚕的文明史,是世界桑资源分布中心。目前的桑园面积达800万hm^2,2000万户农民从事栽桑养蚕,有利地促进了我国蚕丝产量占有国际70％-80％的份额。随着桑蚕产业的大力发展,近年来国内外科研工作者对桑资源研究取得了长足进展。基于中药资源化学研究思路与方法对桑资源性成分研究、动态评价以及桑资源的多途径、多层次开发利用研究等方面进行了较为系统归纳和总结,以期为桑资源产业链的发展提供依据与参考。