杂交手术技术在复杂型Stanford B型主动脉夹层及其并发症治疗的临床研究

目的探讨杂交手术治疗复杂型Stanford B型主动脉夹层的可行性。方法自2011年8月至2015年8月期间,笔者所在医院共有14例复杂型Stanford B型主动脉夹层患者完成腔内修复术(thoracic endovascular aortic repair,TEVAR)并行杂交手术治疗。其中男11例,女3例;年龄(44±7.2)岁(22~62岁)。12例患者夹层动脉瘤累及主动脉弓部及其三大分支血管,其中2例TEVAR手术患者分别于术后3年和5年支架近端新发夹层或假性动脉瘤形成行开胸杂交手术治疗;3例为累及左颈动脉行颈-颈杂交术;7例为累及左锁骨下动脉行颈-锁杂交术。另2例夹层动脉瘤累及髂动脉且合并血栓形成导致下肢缺血,行股-股杂交术。结果所有患者均成功完成覆膜支架的置入并行杂交手术。术中血管造影见支架释放位置准确,夹层隔绝成功,支架无明显内漏和移位,主动脉夹层真腔血流恢复正常,旁路及目标血管血流通畅。14例患者术后均获随访,随访时间为(24.0±8.2)个月(3~36)个月;术后2 d出现脑卒中1例,术后10 d出现切口下血肿1例,术后1个月出现胸腔积液1例,其余患者围手术期无死亡和严重并发症发生。随访的14例患者均恢复正常生活。结论对于复杂型Stanford B型主动脉夹层患者实施杂交手术可以增加TEVAR术的成功率及其使用范围,早、中期效果满意。     

直视支架象鼻手术治疗急性复杂型StanfordB型主动脉夹层

目的总结直视支架象鼻手术治疗急性复杂型Stanford B型主动脉夹层的临床经验及手术适应证。方法纳入2009年2月至2013年4月在北京安贞医院行直视支架象鼻手术的25例急性复杂型Stanford B型主动脉夹层患者,男22例、女3例,年龄30~66(46.92±9.12)岁;合并高血压病16例,术前合并急性肾功能不全3例。患者均在低温体外循环下,经主动脉弓切口放入并缝合术中支架象鼻血管。同期行解剖外旁路血管手术11例,Bentall手术1例,主动脉瓣置换术3例,升主动脉成形术3例。术后出院前均行CT血管造影(CTA)检查。所有患者均随访。随访时复查主动脉CTA。结果手术时间4~7(5.5±0.7)h,体外循环时间93~206(137.64±30.02)min,主动脉阻断时间28~109(57.96±21.05)min,选择性脑灌注时间15~76(26.76±11.88)min。无手术死亡。术后气管内插管2例,近端吻合口漏2例,急性肾功能衰竭1例,一过性神经系统并发症1例,突发心室颤动1例,切口延迟愈合1例。术后随访6~54(25.76±16.15)个月,失访2例,随访率92%。随访期间无死亡。结论直视支架象鼻手术是治疗复杂型Stanford B型主动脉夹层的可靠手段。其手术适应证为近端锚定区不足的复杂型Stanford B型主动脉夹层;合并升主动脉病变,主动脉根部病变,近端心脏疾病如心瓣膜病、冠状动脉粥样硬化性心脏病、先天性心脏病的Stanford B型主动脉夹层;病因为遗传性结缔组织病的Stanford B型夹层患者。     

同期杂交手术治疗复杂Stanford B型主动脉夹层

目的回顾性分析同期杂交手术治疗复杂Stanford B型主动脉夹层的手术方法及疗效,探讨基层医院施行该手术的可行性。方法2010年12月至2013年3月襄阳市中心医院胸心外科对7例复杂Stanford B型急性主动脉夹层患者施行同期杂交手术治疗。男2例、女5例,年龄45～64（50．0±8.3）岁。术前主动脉CT血管造影（CTA）示主动脉夹层破口距左锁骨下动脉开口〈15mm 4例,累及左锁骨下动脉开口3例,其中1例合并胸主动脉壁多部位钙化,冠状动脉CTA示前降支近中段狭窄约70％。采用气管内插管静脉复合麻醉,手术室先期行颈部切口完成主动脉弓分支旁路手术,术毕转送导管室行股动脉切口完成主动脉腔内修复术,冠状动脉粥样硬化性心脏病患者同期完成前降支支架植入术。结果所有患者均成功完成手术,并植入覆膜支架。1例术后发生少量Ⅰ型内漏。围术期无死亡和严重并发症发生。术中CTA证实主动脉夹层真腔血流恢复正常,旁路血管血流通畅,支架植入定位准确,支架无明显移位。随访7例,随访时间3～24（12．0±3．6）个月,所有患者均生存,恢复正常生活。6例术后3个月及术后1年或2年复查主动脉增强CT示支架无移位和内漏,支架内及人工血管旁路血流通畅;1例少量Ⅰ型内漏患者术后3个月复查假腔内仍有造影剂显示,但部分血栓形成,假腔程度及范围较术前变小,真腔明显增大,术后6个月复查内漏消失。所有患者未见脑部和肢体缺血征象。结论复杂Stanford B型主动脉夹层采用同期杂交手术治疗安全、有效,扩大了介入覆膜支架腔内治疗的适应证,在基层医院值得推广应用。     

一站式杂交手术治疗Stanford A型主动脉夹层的临床研究

目的探讨杂交手术治疗Stanford A型主动脉夹层的方法及临床疗效。方法 2016年1月～2016年12月,Stanford A型主动脉夹层病人22例,均完成了杂交手术。术后即刻行升主动脉造影,术后1个月个随访CT资料,观察支架和人工血管通畅情况。结果所有病人均成功完成杂交手术,并植入覆膜支架。术中血管造影证实支架植入定位准确,无明显内漏和移位。主动脉夹层真腔血流恢复正常,围手术期无死亡和严重并发症发生。随访22例,随访时间3个月,所有病人均生存,并恢复正常生活。术后1个月、3个月,复查主动脉增强CT显示,支架无移位和内漏,支架内及人工血管旁路血流通畅。结论 Stanford A型主动脉夹层采用杂交手术,安全、有效,能明显减轻病人的创伤和痛苦,该方法扩大了介入覆膜支架腔内治疗的适应证,但远期疗效有待进一步观察。     

老年StanfordB型主动脉夹层的手术治疗

目的 探讨老年Stanford B型主动脉夹层患者的手术治疗方法.方法 老年Stanford B型主动脉夹层患者47例分为两组,开放组采用深低温停循环下带支架人工血管置入术31例,介入组经股动脉行腔内覆膜支架人工血管植入术16例.结果 开放组,2例死于多器官功能衰竭,1例死于急性心梗;2例术后出现脑梗塞,其中1例死亡;一过性精神障碍11例,声音嘶哑3例.介入组,术后出现左上肢缺血3例,脑梗塞2例,其中1例术后出现大面积脑梗塞,8d后死亡.结论 对老年胸降主动脉夹层者须根据患者的不同情况,采用适合的治疗方法,以提高治疗效果.     

累及肠系膜上动脉的Stanford B型夹层主动脉瘤的治疗

目的探讨Stanford B型主动脉夹层动脉瘤(aortic dissection aneurysm,ADA)引起肠道缺血(intestinal ischemia)的治疗。方法回顾分析2005年1月至2006年2月8例累及肠系膜上动脉(superior mesenteric artery,SMA)的Stanford B型急慢性ADA的治疗方法。其中有5例SMA完全开口于假腔,为了预防腔内修复(endovascular repair,EVR)术后出现肠道缺血,先行髂动脉-SMA人工血管旁路术,再行腔内修复降主动脉夹层动脉瘤。1例ADA急性期出现肠坏死行小肠部分切除,SMA内膜切除及固定。1例EVR术后肠缺血缓解。1例EVR术后7个月出现SMA夹层,保守治疗。结果所有5例行内脏动脉重建者均获得成功,无围手术期死亡。所有8例降主动脉夹层动脉瘤EVR均获得成功,1例出现Ⅱ型内瘘,无肠道缺血症状出现。术后随访平均7.5(1～14)个月,CTA示SMA通过移植血管显影通畅;人工血管内支架无移位、断裂;出现Ⅱ型内瘘患者术后3个月随访CTA内瘘消失。结论内脏动脉受累的Stanford B型急慢性ADA,术前正确的判断及合理的手术方式往往可以挽救患者的生命,减少主动脉破裂的危险以及内脏缺血致死的可能。     

血管腔内治疗主动脉夹层和夹层动脉瘤

目的 探讨血管腔内治疗主动脉夹层和夹层动脉瘤的技术方法和疗效。方法 对20例主动脉夹层和夹层动脉瘤患者的临床资料进行分析。Stanford A型2例,其中1例内膜撕裂口位于升主动脉。Stanford B型18例。5例在不同部位有2个以上撕裂口。全组均以带膜支架型人工血管腔内植入行隔绝术。其中1例加作腹主动脉开窗和人工血管置换术,1例先行升主动脉．左锁骨下动脉和左颈总动脉Y形人工血管旁路术,再行腔内隔绝术。结果 无一例患者术中死亡,术后3d 1例Stanford B型患者死于心肌梗死,其余19例健康存活,生存率95％。术后随访1—20个月,各例主动脉夹层和动脉瘤均消失,无内漏,各器官灌注良好。结论 血管腔内植入带膜支架型人工血管是治疗主动脉夹层和夹层动脉瘤的简便、安全而有效的方法。手术死亡率低,手术成功率和生存率高。     

不同杂交方式治疗累及弓部的主动脉夹层

目的探讨不宜单独行腔内隔绝治疗、累及弓部的主动脉夹层杂交手术治疗方法及其疗效。方法回顾性分析2008年11月至2011年8月成都军区总医院15例累及弓部的主动脉夹层患者行杂交手术治疗的临床资料,其中男10例,女5例;年龄51～72(58.2±7.2)岁。Stanford A型主动脉夹层4例,B型主动脉夹层11例,病变均累及主动脉弓。采用胸骨正中切口或加颈部切口行升主动脉至头臂动脉旁路移植、单纯颈部切口行头臂动脉间旁路移植,然后行股动脉切口逆行主动脉腔内覆膜支架植入。术后即刻行数字减影血管造影(DSA),术后3个月、术后1年和2年分别随访CT造影资料,观察支架和人工血管通畅情况。结果所有患者均成功完成手术,并植入覆膜支架。术中血管造影证实支架植入定位准确,支架无明显内漏和移位。主动脉夹层真腔血流恢复正常,旁路血管血流通畅,围术期无死亡和严重并发症发生。随访15例,随访时间3～20(12.0±4.1)个月,所有患者均生存,恢复正常生活。术后3个月及术后1年、2年复查主动脉增强CT示:支架无移位和内漏,支架内及人工血管旁路血流通畅,未见脑部和肢体缺血征象。结论累及弓部的主动脉夹层可根据受累部位和程度采用不同的杂交手术方法,安全、有效,能明显减轻患者的创伤和痛苦,该方法扩大了介入覆膜支架腔内治疗的适应证,但远期疗效有待进一步观察。     

主动脉夹层的细化分型及其应用

目的探讨在Stanford分型的基础上根据主动脉夹层的部位和病变程度再进行细化分型,对指导临床选择手术时机、确定治疗方案和手术方式,以及判断预后的价值。方法1994年1月至2004年12月我院治疗主动脉夹层708例。其中Stanford A型夹层477例：（1）根据主动脉根部病变程度分为3型。A1型（主动脉窦部正常型）212例,行保留主动脉窦部的主动脉替换;A2型（主动脉窦部轻度受累型）72例,行主动脉窦部成形63例、David手术9例;A3型（主动脉窦部重度受累型）193例,行主动脉根部替换术（Bentall手术）。（2）根据主动脉弓部病变分为2型。C型（复杂型）78例,行主动脉弓部替换＋象鼻术;S型（单纯型）399例,行部分主动脉弓部替换。Stanford B型夹层231例,（1）根据主动脉扩张的范围分为3型：B1型：降主动脉无扩张或仅有近端扩张,147例,行腔内带膜支架主动脉腔内修复术103例（B1S型）、部分胸降主动脉替换术32例、部分胸降主动脉替换术＋远端支架象鼻术12例;B2型：全部胸降主动脉扩张,53例,行部分胸降主动脉替换术＋主动脉成形32例、全部胸降主动脉替换术21例;B3型：全部胸降主动脉及腹主动脉扩张,31例行胸腹主动脉替换术。（2）根据左锁骨下动脉和远端主动脉弓部是否受夹层累及分为2型：C型（复杂型）：夹层累及左锁骨下动脉或远端的主动脉弓部,44例,在深低温停循环下手术治疗;S型（单纯型）：远端主动脉弓部和左锁骨下动脉未受夹层累及,187例,介入治疗103例、手术治疗84例（常温阻断下手术60例,股动脉-股静脉转流下手术24例）。结果Stanford A型夹层住院病死率为4．6％（22／477）,并发症发生率为14．5％（69／477）。Stanford B型夹层：介入治疗组病死率1．9％（2／103）,并发症发生率为2．9％（3／103）,轻度内漏发生率为9．7％（10／103）;手术治疗组住院病死率为3．1％（4／128）,并发症发生率为18．8％（24／128）。结论细化主动脉夹层的分型对于术前判断手术时机、制定手术方案和初步判断预后,具有重要的指导作用。     

单分支主动脉覆膜支架修复伴锚定区不足的急性Stanford B型夹层：附8例报告

背景与目的 单分支型主动脉覆膜支架及其传输系统是近年国内研发的新型支架系统,适用于锚定区不足的主动脉夹层,是累及左锁骨下动脉（LSA）主动脉夹层的新选择。笔者通过总结使用该支架系统行胸主动脉覆膜支架腔内隔绝术（TEVAR）治疗锚定区不足的急性Stanford B型的病例,评估其近期效果与安全性。方法 回顾性收集2019年4月—2020年1月,在云南省阜外心血管病医院血管外科采用Castor^?一体化分支型主动脉覆膜支架行TEVAR的Stanford B型夹层伴锚定区不足的8例患者的临床资料。分析手术过程及围手术期并发症情况。结果 8例患者中,男7例（87.5%）,女1例（12.5%）;中位年龄42（33~64）岁;BMI（25.5±3.8）kg/m²。8例均成功植入支架,初始技术成功率100%,无围手术期死亡及神经系统并发症,无I型内漏。平均住院时间为（14.8±3.7）d。平均随访时间为223（60~370）d,所有主体、分支支架血管通畅、无相关I和III型内漏,无神经系统并发症,无左上肢缺血表现。结论 应用单分支覆膜支架行TEVAR治疗Stanford B型夹层伴锚定区不足是一种安全、有效的方法,中远期疗效有待随访。     

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.     

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.     

Negative pressure ventilation vs. spontaneous assisted ventilation during rigid bronchoscopy: A controlled randomised trial

Background: Ventilation during interventional rigid bronchoscopy (IRB) under general anaesthesia (jet ventilation, positive pressure ventilation and spontaneous assisted ventilation) may offer some difficulties. This study compares the effectiveness during IRB of intermittent negative pressure ventilation (INPV) and spontaneous assisted ventilation (SAV). Methods: Thirty-eight patients submitted to IRB were randomised into two groups: SAV or INPV. All patients received a total intravenous anaesthesia; INPV patients were paralysed. Pre-and intra-operative arterial blood gases and O₂ flow through a rigid bronchoscope were assessed. The endoscopist applying a subjective score evaluated the operating conditions. Results: Patients of the INPV group, as compared to the SAV group, required a lower dosage of fentanyl (2.6 ± 1.8 (μg · kg^?1· h^?1 vs. 6.6 ± 4.8 μg · kg^?1· h^?1), a lower O₂ supply (3.3 ± 2.8 1/min vs. 11.6 ± 3.4 1/min), a shorter recovery time (5.4 ± 2.9 min vs. 9.8 ± 7.1 min) and no manually assisted ventilation (0 ± 0 vs. 1 ± 1.1 nd?/procedure). Intraoperative PaCO₂ was higher in the SAV (8.1 ± 1.3 kPa) than in the INPV group (5.0 ± 1.6 kPa) and intraoperative pH differed in the two groups (7.26 ± 0.05, SAV vs. 7.47 ± 0.08, INPV). Operating conditions, as assessed by a subjective score, were considered better with INPV than with SAV (4.9 vs. 4.3). Conclusions: As compared to SAV, INPV in paralysed patients during IRB reduces administration of opioids, shortens recovery time, prevents respiratory acidosis, excludes the need for manually assisted ventilation, reduces 02 need and affords optimal surgical conditions. INPV appears a safe, non-invasive and effective ventilatory management during IRB.