微小RNA-150在肝细胞癌中的表达及其临床意义

【摘要】〓目的〓探讨微小RNA(miR)-150在肝细胞癌中的表达及其临床意义。方法〓实时荧光定量聚合酶链反应(qRT-PCR)检测肝癌及配对癌旁组织中miR-150表达。原位杂交技术(ISH)进一步验证肝癌和配对癌旁组织miR-150表达差异。将肝癌组织中miR-150表达与临床病理特征进行关联分析。Kaplan-Meier法检测miR-150阴性组和阳性组生存曲线。Cox单因素回归模型分析miR-150表达与患者术后总生存的相关性。结果〓qRT-PCR结果显示:与癌旁组织相比,12例中有8例肝癌组织低表达miR-150,肝癌组织中miR-150表达明显降低(P=0.034)。ISH结果与qRT-PCR结果相一致,即肝癌组织大部分为阴性或弱阳性表达,62%癌旁组织ISH染色强度高于配对的肝癌组织(P<0.001)。关联分析提示miR-150表达与AFP、肿瘤大小、TNM分期、组织学分级、脉管癌栓存在明显负相关(P<0.05)。miR-150阳性组患者术后总生存明显高于miR-150阴性组(P=0.004,Kaplan-Meier法)。Cox单因素回归分析提示肝癌组织低表达miR-150是患者不良预后指标(P=0.005)。结论〓肝癌组织低表达miR-150与肿瘤侵袭表型相关,提示不良预后。     

miR-20b在乳腺癌的表达及对乳腺癌细胞增殖的影响

【摘要】〓目的〓观察miRNA-20b(miR-20b)在乳腺癌组织中的表达情况和对乳腺癌细胞株生长凋亡的影响。方法〓运用实时定量RT-PCR检测134例乳腺浸润性导管癌组织miR-20b的表达,并与临床病理资料和生存时间进行相关分析;瞬时转染miR-20b抑制物到乳腺癌细胞中,CCK-8法和流式细胞术检测细胞增殖和凋亡情况。结果〓miR-20b在乳腺癌组织中表达量明显高于癌旁组织(P<0.001)。其表达与肿瘤大小、远处转移情况及Ki67表达相关(P<0.001)。miR-20b高表达组病人的无病生存期(DFS)和总生存期(OS)短于低表达组(P<0.05)。转染miR-20b抑制物后,细胞增殖减弱(P<0.05),凋亡增强(P<0.05)。结论〓乳腺癌组织中miR-20b表达与乳腺癌预后相关,可作为乳腺癌恶性程度的预测指标。     

微RNA-21在肝细胞癌中的表达及其靶基因研究

目的 探讨微RNA(miRNA)-21在肝细胞癌中的表达特征及其功能,筛选并鉴定miRNA-21可能调控的靶基因.方法 用PAGE/Northern blot方法分析miRNA-21在10例肝细胞癌患者组织标本中的表达特征,并在3种肝癌细胞株中加以验证.用生物信息学分析预测miRNA-21可能的靶基因,通过逆转录-聚合酶链反应(RT-PCR)方法克隆靶基因的调控区序列,利用荧光素酶双报告基因系统筛选,并通过Western blot、流式细胞仪在蛋白质水平进行分析验证.用体外细胞侵袭实验分析miRNA-21与肝癌细胞侵袭能力的关系.结果 miRNA-21在10例肝细胞癌患者中均表达上调,与癌旁组织比较,表达量增加10倍以上.在3种肝癌细胞株中也得到相似的结果.筛选并确认了RECK为miRNA-21的调控靶基因之一.抑制miRNA-21的表达可明显降低肝癌细胞的侵袭.结论 miRNA-21在肝细胞癌中表达失控,通过抑制RECK表达促进肿瘤细胞侵袭.     

miRNA-138与EZH2在肾透明细胞癌发生发展中作用机制的研究

目的:探讨miRNA-138及其调控靶基因EZH2在肾透明细胞癌(RCC)发生发展中的相关作用机制。方法:利用第二代大规模平行测序技术对10例RCC及对应癌旁组织进行全基因组测序,在肾癌组织中筛选出表达显著上调的miRNA-138;其次在人肾癌细胞株786-O、ACHN、Caki-1、769-P、os-rc-2及对照细胞人胚肾细胞293T中对miRNA-138进行转染,采用划痕实验检测miRNA-138对细胞株侵袭和迁移能力的影响;进而用多种预测软件预测靶基因,对预测的候选靶基因EZH2进行PCR验证。结果:发现miRNA-138在RCC中表达上调,并能够显著促进人肾癌细胞株786-O、ACHN的迁移;而其候选靶基因EZH2的表达在临床组织标本中显著上调;相应蛋白变化需要进一步验证。结论:EZH2表达在RCC中明显高于正常组织,提示EZH2可能是RCC一个敏感的生物学标志。推测miRNA-138与其靶基因EZH2可能参与肿瘤代谢和细胞凋亡等信号通路,在RCC的发生发展中发挥重要作用。     

miR-143-3p在胃癌组织中的表达和临床意义研究以及生信分析

目的探索miR-143-3p在胃癌细胞和胃癌组织中的表达、并分析其异常表达的临床意义;同时采用生物信息学方法,进行靶基因和信号通路富集分析。方法采用实时荧光定量PCR法检测miR-143-3p在正常胃黏膜细胞和5种胃癌细胞,以及胃癌组织和癌旁组织中的表达,并分析其临床意义。采用OncomiR和YM500数据库分析miR-143-3p在胃癌组织和癌旁组织中的表达。采用miRecords网站数据库的预测软件预测其靶基因,选择至少3个以上软件支持的靶基因,运用DAVID 6.7软件在线富集分析其靶基因参与的信号通路。结果实验结果表明:相对于正常胃黏膜上皮细胞GES-1,miR-143-3p在不同分化程度的胃癌细胞,包括SGC-7901(中分化)、MKN-45(中分化)、MGC-803(低分化)、BGC-823(低分化)和HGC-27(未分化)细胞中的表达量均明显下调(P0.001)。实时荧光定量PCR检测结果表明:相对于癌旁组织,miR-143-3p在胃癌组织中的表达在36例中下调,在18例中上调,4例变化不明显。miR-143-3p在胃癌组织中的表达与胃癌淋巴结转移以及浸润深度相关(P0.05)。生信分析结果显示,miR-143-3p的靶基因富集在38个与肿瘤相关的信号通路中。结论 miR-143-3p是胃癌中表达下调的分子标志物,是潜在的具有临床相关性的抑癌基因,可能参与胃癌发生发展过程中的生物学行为。     

基于生物信息学的肝细胞癌组织miR-1180表达与临床意义分析

目的:通过生物信息学数据分析探讨肝细胞癌(HCC)组织中miR-1180的表达及其临床意义。方法:下载GEO(Gene Expression Omnibus)和TCGA(The Cancer Genome Atlas)相关数据集,比较HCC组织和癌旁组织中miR-1180表达量,并分析miR-1180表达量与肝癌患者临床病理特征及预后之间的相关性。利用生物信息学方法对mi R-1180的靶基因进行预测及功能富集分析,并结合预后分析结果筛选miR-1180关键靶基因。结果:mi R-1180在HCC组织中较癌旁组织高表达,且对于HCC具有良好的诊断效能(AUC0.8,均P0.05);miR-1180的表达量与患者年龄、肿瘤家族史、肿瘤分化程度以及AFP等指标明显有关(均P0.05)。生存分析表明HCC组织中miR-1180高表达是影响HCC患者预后的独立危险因素(P0.05)。富集分析提示miR-1180的靶基因主要富集于脂质代谢、细胞迁移、转录调控等功能和脂肪酸降解等通路。PPARGC1A、ALDH2、SARDH、HMGCS2、ESR1、ETS2等为miR-1180关键靶基因,在HCC组织中均表达下调(均P0.05),且相对低表达者预后较差(均P0.05)。结论:mi R-1180在HCC组织中表达升高,其可能作为一种促癌miRNA参与HCC的发生、发展,并具有成为HCC诊断标志物、预后指标及治疗靶点的潜在应用价值。     

microRNA-497 在肝细胞癌中的表达及意义

目的:探讨microRNA-497(miR-497)在肝细胞癌组织中的表达及其意义.方法:收集40例肝细胞癌及对应癌旁组织标本,用qRT-PCR方法检测标本中miR-497的表达;人肝癌SMMC-7721细胞经miR-497模拟物转染后,用MTT和流式细胞术检测其增殖能力与凋亡水平的变化,并用qRT-PCR和Western blot检测miR-497潜在靶点Bcl-w的mRNA与蛋白的表达.结果:miR-497在肝癌组织中的表达水平明显低于其癌旁组织[(1.181±0.779)vs.(14.599±5.266),P＜0.05];转染miR-497模拟物的SMMC-7721细胞增殖能力明显降低,细胞凋亡增加,Bcl-w的mRNA与蛋白表达均明显降低(与未转染的SMMC-7721细胞比较,均P＜0.05).结论:肝癌组织中miR-497表达下调,该下调可能导致靶基因Bcl-w表达升高,从而促进肿瘤的发生与发展.     

胃癌组织中miR-497表达及其生物学意义

目的检测胃癌组织和癌旁组织中miR-497的表达差异,寻找其下游作用靶点。方法选取2010-2013年期间在中国医科大学附属第一医院胃肠外科手术切除的94例胃癌及其癌旁组织。用RT-PCR法定量检测miR-497在其中的表达;在线软件预测miR-497靶基因,用阴性对照及miR-497-mimics转染SGC-7901细胞系,RT-PCR及Western检测胃癌细胞miR-497过表达后靶点基因mRNA及蛋白水平的改变;MTT法检测miR-497-mimics组（miR-497过表达）细胞株与阴性对照组间对5-氟尿嘧啶（5-FU）化疗的敏感性。结果①miR-497表达量在胃癌组织中明显低于癌旁组织,差异有统计学意义（P〈0．01）。②BCL2L2被预测为miR-497的靶基因,miR-497在胃癌SGC-7901细胞中过表达后BCL2L2蛋白表达在miR-497-mimics组细胞中明显弱于阴性对照组细胞,BCL2L2mRNA在2组细胞中的表达差异无统计学意义（P〉0．05）。miR-497-mimics组细胞对5-FU的Ic50值明显低于阴性对照组细胞（P=0．0046）。结论miR-497在胃癌组织中低表达,BCL2L2为miR-497的靶基因,miR-497过表达可提高胃癌细胞对5-Fu的敏感性,这为进一步研究miR-497与BCL2L2在胃癌中的作用及治疗提供了新的方向。     

miR-145-5p在肝细胞癌中的表达及其临床意义

目的 探讨miR-145-5p表达水平与肝细胞癌（肝癌）临床病理特征及其预后的关系。方法 通过分析Gene Expression Omnibus(GEO)中肝癌芯片数据,采用实时荧光定量PCR方法检测肝癌临床手术组织标本及其癌旁正常组织、肝癌细胞系及石蜡包埋肝癌组织中miR-145-5p相对表达量,分析其与肝癌临床病理特征的关系,并进行Kaplan-Meier生存曲线及单因素和多因素分析影响肝癌患者总体生存的危险因素。结果 miR-145-5p在肝癌细胞系、肝癌组织中表达分别低于正常肝细胞和癌旁组织（P<0.001）;miR-145-5p的相对表达量与转移及肿瘤分化相关参数肿瘤数目（P=0.040）、脉管侵犯（P=0.010）、Edmondson-Steiner分级（P=0.011）、BCLC分期（P=0.003）有关。Cox多因素分析发现,肿瘤数目、脉管侵犯、Edmondson-Steiner分级、BCLC分期和miR-145-5p表达量是影响肝癌患者总体生存的独立危险因素（HR=2.864、2.114、3.157、4.106、3.594;均P<0.05）,同时也是影响肝...     

miR-144CCNB1信号调节通路在肝癌增殖、迁移和侵袭作用及相关机制的研究

目的探讨microRNA-144细胞周期蛋白B1(miR-144CCNB1)信号调节通路在肝癌增殖、迁移和侵袭作用及其相关机制。方法以2011年1月~2016年1月我院收治的100例肝癌患者的肝癌组织和癌旁组织为研究标本,采用荧光定量PCR(qRT-PCR)法检测肝癌及其癌旁组织的miR-144表达和CCNB1蛋白表达情况,采用RNA干扰技术沉默CCNB1基因,并将靶向CCNB1的siRNA转染至肝癌细胞系HepG2和QGY-7703中,检测其对肝癌细胞生长、迁移和侵袭的生物学行为的影响。结果肝癌组织中miR-144表达较癌旁组织明显下调,CCNB1蛋白在肝癌组织的表达水平较癌旁组织明显上调,miR-144高表达者预后无瘤生存期较其低表达者明显长,而CCNB1蛋白低表达者无瘤生存期明显长于其高表达者,差异有统计学意义(P0.05);与未处理者和阴性对照模拟物相较,转染CCNB1 siR肝癌细胞CCNB1蛋白表达水平明显下降;与未处理和阴性对照模拟物相较,转染CCBN1 siR HepG2细胞凋亡百分明显升高,转染CCNB1 siR HepG2细胞增殖能力明显下降,转染CCNB1siR HepG2细胞迁移能力明显降低;与阴性对照模拟物和未处理细胞相较,转染CCNB1-siR QGY-7703细胞克隆团数(成瘤能力)明显减少。结论 miR-144CCNB1信号调节通路在肝癌增殖、迁移和侵袭中发挥重要作用,其可能机制为miR-144负向调控CCNB1表达,从而影响肝癌细胞增殖、凋亡、迁移等生物学行为,为肝癌治疗的新靶点提供理论依据。     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.     

Intraoperative autotransfusion is associated with modest reduction of allogeneic transfusion in prosthetic hip surgery

Background: The efficacy of intraoperative salvage and washing of wound blood and the predictors of allogeneic red cell transfusions in prosthetic hip surgery are insufficiently known.
Methods: In 96 patients, undergoing primary or revision surgery, salvaged and washed red cells and, if necessary, allogeneic blood were used to keep haematocrit not lower than 33%. The bleeding of red cells during hospital stay was calculated from the red cell balance. The preoperative red cell reserve (millilitres of red cells in excess of a haematocrit of 33%) was estimated and the difference between this volume and the total bleeding of red cells was retrospectively used to classify patients with regard to the need for red cells. Stepwise regression analysis was used to define patient-related variables associated with allogeneic blood transfusion.
Results: Preoperative knowledge of the type of operation (primary, revision), the preoperative red cell reserve, and the body mass could predict roughly half of the need for banked blood (r²=0.45). Only one-third of the total bleeding of red cells was retransfused. For complete avoidance of allogeneic blood, autotransfusion was most effective in patients with a moderate need (0–4 u). However, 32% of such patients required allogeneic blood.
Conclusions: Autotransfusion has a limited efficacy to decrease the need for allogeneic blood, and other blood-saving methods should be added for this purpose. It is difficult to predict the need for allogeneic blood preoperatively.     

缺氧对肾小管上皮细胞分泌外泌体的影响

目的    观察缺氧对肾小管上皮细胞分泌外泌体的影响,探讨外泌体在缺氧致肾脏损伤中的作用及机制。 方法    （1）常氧（21% O₂）及缺氧（1% O₂）分别处理大鼠肾小管上皮细胞（NRK-52E）48 h,收集细胞上清液并使用高速梯度离心法分离外泌体。采用透射电镜、纳米示踪分析、Western印迹、蛋白浓度定量鉴定并比较两组外泌体的基本特性。（2）在共培养实验中,以不同浓度（1、10、50、100、300 mg/L）的常氧外泌体、缺氧外泌体分别干预脂多糖（LPS）诱导的大鼠原代腹腔巨噬细胞,使用实时荧光定量PCR与酶联免疫吸附试验（ELISA）法分别检测巨噬细胞白细胞介素6（IL-6）、肿瘤坏死因子α（TNF-α）、诱导型氮氧化物合酶（iNOS）水平;使用Western印迹法检测巨噬细胞磷酸化（p）STAT/STAT及细胞因子信号传导抑制蛋白1（SOCS1）的蛋白表达;最后,使用实时荧光定量PCR法检测常氧外泌体与缺氧外泌体中炎性反应相关微RNA（microRNA,miR）的表达差异。 结果    （1）离心得到的囊泡具有外泌体典型的结构,粒径小于150 nm,表达外泌体标志蛋白CD63,说明分离得到外泌体。缺氧对肾小管上皮细胞分泌的外泌体形态、粒径分布比例无明显影响,但提高了外泌体的分泌量。（2）缺氧外泌体相比于常氧外泌体促进了LPS诱导的M1型巨噬细胞IL-6、TNF-α、iNOS 的表达和分泌（均P＜0.01）,同时提高STAT的磷酸化水平并减少SOCS1的蛋白表达（均P＜0.01）;对炎性反应相关microRNA检测发现缺氧外泌体中miR-155、miR-27a表达量较常氧外泌体明显升高（P＜0.05）。 结论    缺氧可改变外泌体的生物学功能,表现为协同促进LPS诱导的M1型巨噬细胞的表型转化,这可能是慢性肾脏病微炎性反应状态持续的原因之一。     

In Vitro Function and Durability Assessment of a Novel Polyurethane Heart Valve Prosthesis

Abstract While flexible-leaflet, central-flow prosthetic heart valves promise relief from anticoagulation therapy, they continue to be restricted by inadequate durability. In consequence, a novel trileaflet valve, made entirely from polyurethane, has been developed. A batch of 6 consecutively manufactured polyurethane valves was subjected to hydrodynamic function and accelerated fatigue testing. Computerized data acquisition and control systems have been introduced to improve valve testing methodologies. In terms of hydrodynamic function, the polyurethane valve demonstrates transvalvular pressure gradients similar to those for a bioprosthetic valve (Carpentier-Edwards) and levels of retrograde flow significantly less than those for either the bioprosthetic valve or a bileaflet mechanical valve (St Jude Medical). The equivalent of 10 years of cycling without failure has been exceeded by all 6 polyurethane valves in accelerated fatigue tests with 2 valves remaining intact after 674 million cycles (equivalent to approximately 17 years) in continuing tests. Highspeed photography revealed considerable differences in leaflet motion between valves cycled at accelerated and physiological rates.