重症肌无力合并胸腺瘤手术治疗的近期疗效及危象发生的临床分析

目的观察重症肌无力合并胸腺瘤的手术治疗的近期疗效及危象发生的情况，分析疗效和危象的相关因素。方法1994年1月至2005年1月手术治疗重症肌无力（MG）436例，其中58例合并胸腺瘤。肌无力按改良Osserman分型，Ⅰ型17例，Ⅱa型23例，Ⅱb型12例，Ⅲ型6例；胸腺瘤Masaoka分期Ⅰ期30例，Ⅱ期18，Ⅲ期7例，Ⅳ期3例。对术后近期疗效和发生危象发生情况进行统计分析。结果手术后缓解16例（27．59％），无效18例（31．03％），恶化11例（18．97％），危象及死亡13例（22．41％）。Logistic回归分析发现，MG合并胸腺瘤者发生危象的可能性是无胸腺瘤者的1．286倍，MG伴有胸腺瘤者、MGⅡ型及以上者是术后发生危象的高危人群。Ⅰ型与Ⅱ型及以上者术后近期的危象发生率差异有统计学意义（P〈0．05）。Ⅰ期与Ⅱ期及以上胸腺瘤者术后近期的危象发生率差异无统计学意义（P〉0．05）。结论MG合并胸腺瘤的病人术后危象的发生率明显增加，MGⅡ型及以上型术后更容易发生危象，危象的发生与胸腺瘤的病理分期无相关性。     

重症肌无力外科治疗的围手术期处理

目的探讨重症肌无力（MG）外科治疗的围手术期处理方法及疗效。方法158例患者，男65例，女93例，年龄3—61岁，OssemanⅠ型93例，Ⅱa型38例，Ⅱb型17例，Ⅲ型10例。术前正确处理合并症，使用药物控制肌无力症状，术中完整切除胸腺并清扫前纵隔脂肪；术后联合使用抗胆碱酯酶药、激素及免疫抑制剂，应用呼吸机进行人工辅助呼吸，防治重症肌无力危象。结果全组患者均无手术或住院死亡，Ⅰ型MG患者术后早期症状缓解26例，明显改善19例，改善27例；Ⅱ、Ⅲ型MG患者术后早期症状缓解33例，明显改善21例；总有效率为76．6％。结论重症肌无力患者经充分的围手术期处理，可安全接受手术治疗，手术疗效好。     

胸腺癌并重症肌无力危象的围手术期治疗

重症肌无力（MG）危象是胸腺瘤病人术后最严重的并发症之一,死亡率高,及时诊断、处理是抢救成功的关键。我们自1985年6月至1998年12月共手术治疗46例胸腺瘤合并MG的病人,15例术后发生MG危象,均抢救成菌,无围手术期死亡,现将抢救体会总结如下。     

胸腺瘤切除术后重症肌无力的临床分析

目的 探讨胸腺瘤切除术后出现重症肌无力(MG)患者的临床病理特点。方法 回顾性分析15例胸腺瘤切除术后出现MG患者的临床资料,并与同时期手术平均随诊5．5年未发现：MG的全部112例单纯胸腺瘤患者的临床资料比较。15例胸腺瘤切除术后出现MG患者中女性9例、男性6例;胸腺瘤Masaoka分期Ⅰ期7例、Ⅱ期4例、Ⅲ期4例;上皮细胞型3例、淋巴细胞型4例、混合型7例、不定1例。平均随诊时间为76．7个月(8～178个月)。结果 (1)胸腺瘤切除术后出现MG的时间为术后麻醉苏醒时至术后137个月(平均33．9个月),MG症状完全缓解时间平均为术后30．9个月(0．5～120个月);(2)麻醉苏醒时即出现：MG的4例患者中,均使用了非去极化肌松剂;(3)术后放射治疗患者中3例出现MG(3／67),出现时间平均为治疗第24天,已照剂量平均为36 Gy;(4)女性、病程较长,混合型,肿瘤较大,病期稍晚者,可能有发生术后MG的倾向。结论 手术、术后放射治疗及麻醉中肌松药选择和剂量控制,均可影响术后MG的发生。     

96例重症肌无力患者的外科治疗

目的总结重症肌无力（MG）患者的外科治疗和围术期处理经验，以提高手术疗效。方法2002年1月至2007年6月，对96例MG患者行胸腺切除加前纵隔脂肪组织清扫术，根据临床相对记分、服药量改变及生活能力于术后3个月评估临床疗效。结果无围术期死亡。术后发生MG危象8例（8．3％），其中术前未服用糖皮质激素6例（18．75％），服用糖皮质激素2例（3．13％），经相应的治疗治愈。术后发生其他并发症9例（9．4%），其中肺部感染7例，切口感染2例，均经相应的治疗治愈。随访96例，随访时间3～18个月，其中32例临床痊愈，30例基本痊愈，15例显效，12例好转，7例无效。结论MG患者经内科治疗效果不佳或无效时，均应考虑手术治疗，无论是否有胸腺增生，特别是对合并有胸腺瘤者，应限期手术。若决定行手术治疗，术前除继续服用抗胆碱酯酶药物外，口服糖皮质激素15d左右可增加手术安全性，提高手术疗效。     

胸腺瘤合并重症肌无力的外科治疗

目的报告1988年～2000年12月手术治疗36例胸腺瘤合并重症肌无力(MG)的结果.方法全部患者均行手术治疗,按Masaoka临床分期Ⅰ期6例,Ⅱ期15例,Ⅲ期12例,Ⅳ期3例.结果术后18例出现重症肌无力危象,均行气管切开及辅助呼吸,1例死于危象.术后随访半年～10年,3年内MG缓解率为72.2%,5年生存率为65.4%,10年生存率为24.8%.结论胸腺切除手术是治疗胸腺瘤合并重症肌无力的主要方法,术后肌无力危象发生率高,及时行气管切开及辅助呼吸是处理的关键.     

胸腺扩大切除术治疗重症肌无力527例

目的总结胸腺扩大切除术治疗重症肌无力(myasthenia gravis,MG)的外科治疗经验,探讨MG外科治疗效果。方法回顾性分析我院1996年6月至2017年10月期间527例行胸腺扩大切除术的MG患者临床病例资料,其中男242例,女285例;年龄5~77岁,平均(52.6±13.7)岁。病程12天~18年。合并甲状腺功能亢进症22例,纯红细胞再生障碍性贫血7例,甲状腺机能减退症、肠激惹症、风湿性关节炎、强直性脊柱炎和血小板减少综合征各1例。改良OssermanⅠ型272例,Ⅱa型72例,Ⅱb型78例,Ⅲ型81例,Ⅳ型24例。所有患者肌疲劳试验、新斯的明试验阳性,胸部CT检查明确诊断。总结围手术期相关资料及术后随访情况。结果围手术期死亡3例,均为胸腺瘤合并MG,其中OssermanⅢ型MG 2例、Ⅳ型MG 1例。术后肌无力危象15例,其中OssermanⅡb型2例、Ⅲ型11例、Ⅳ型2例,气管切开7例。血浆置换70例,并发低渗综合征、下肢静脉血栓各2例。术后病理诊断胸腺增生293例(55.60%)、胸腺瘤207例(39.28%)、胸腺囊肿24例(4.55%)和胸腺萎缩3例(0.57%)。随访378例,平均随访(85.9±58.5)月;MG完全缓解、部分缓解、无变化和恶化患者分别为135例(35.71%)、192例(50.79%)、41例(10.85%)和10例(2.65%)。完全缓解率OssermanⅠ>Ⅱa>Ⅳ>Ⅱb>Ⅲ型,恶化率OssermanⅢ>Ⅳ>Ⅰ型。OssermanⅠ型外科治疗无效18例,术前病程>5~10年;恶化1例,为应用电视胸腔镜胸腺切除的眼肌型MG患者,遗留胸腺左叶未切除,6年后发展为重度全身型,再次手术切除遗留的左叶胸腺,证实左叶胸腺代偿性肥大增生。恶化患者中死亡6例,均为胸腺瘤合并MG,其中OssermanⅢ型5例、Ⅳ型1例;死亡原因为肌无力危象3例,快速停服溴吡斯的明3个月后突发呼吸骤停猝死2例,胆碱能危象1例。结论规范的胸腺扩大切除是治疗MG的有效方法,眼肌型MG尽早手术可有效降低其全身性转化风险。OssermanⅡb型以上MG易发生肌无力危象,围手术期采取综合处理措施有助于降低MG相关风险。重症术后远期可反复发生肌无力危象,须规律用药,并采取MG综合治疗措施。     

胸腺扩大切除术治疗重症肌无力527例

目的总结胸腺扩大切除术治疗重症肌无力(myasthenia gravis,MG)的外科治疗经验,探讨MG外科治疗效果。方法回顾性分析我院1996年6月至2017年10月期间527例行胸腺扩大切除术的MG患者临床病例资料,其中男242例,女285例;年龄5~77岁,平均(52.6±13.7)岁。病程12天~18年。合并甲状腺功能亢进症22例,纯红细胞再生障碍性贫血7例,甲状腺机能减退症、肠激惹症、风湿性关节炎、强直性脊柱炎和血小板减少综合征各1例。改良OssermanⅠ型272例,Ⅱa型72例,Ⅱb型78例,Ⅲ型81例,Ⅳ型24例。所有患者肌疲劳试验、新斯的明试验阳性,胸部CT检查明确诊断。总结围手术期相关资料及术后随访情况。结果围手术期死亡3例,均为胸腺瘤合并MG,其中OssermanⅢ型MG 2例、Ⅳ型MG 1例。术后肌无力危象15例,其中OssermanⅡb型2例、Ⅲ型11例、Ⅳ型2例,气管切开7例。血浆置换70例,并发低渗综合征、下肢静脉血栓各2例。术后病理诊断胸腺增生293例(55.60%)、胸腺瘤207例(39.28%)、胸腺囊肿24例(4.55%)和胸腺萎缩3例(0.57%)。随访378例,平均随访(85.9±58.5)月;MG完全缓解、部分缓解、无变化和恶化患者分别为135例(35.71%)、192例(50.79%)、41例(10.85%)和10例(2.65%)。完全缓解率OssermanⅠ>Ⅱa>Ⅳ>Ⅱb>Ⅲ型,恶化率OssermanⅢ>Ⅳ>Ⅰ型。OssermanⅠ型外科治疗无效18例,术前病程>5~10年;恶化1例,为应用电视胸腔镜胸腺切除的眼肌型MG患者,遗留胸腺左叶未切除,6年后发展为重度全身型,再次手术切除遗留的左叶胸腺,证实左叶胸腺代偿性肥大增生。恶化患者中死亡6例,均为胸腺瘤合并MG,其中OssermanⅢ型5例、Ⅳ型1例;死亡原因为肌无力危象3例,快速停服溴吡斯的明3个月后突发呼吸骤停猝死2例,胆碱能危象1例。结论规范的胸腺扩大切除是治疗MG的有效方法,眼肌型MG尽早手术可有效降低其全身性转化风险。OssermanⅡb型以上MG易发生肌无力危象,围手术期采取综合处理措施有助于降低MG相关风险。重症术后远期可反复发生肌无力危象,须规律用药,并采取MG综合治疗措施。     

胸腺瘤合并重症肌无力患者的手术及围术期处理

目的 为提高胸腺瘤合并重症肌无力（MG）患者手术的安全性和治愈率，总结其临床经验。方法 1991年7月至2005年8月收治胸腺瘤合并MG23例，术前均给予肾上腺糖皮质激素和抗胆碱酯酶药物治疗，病情稳定后行胸腺扩大切除术，对发生MG危象患者予以气管切开或气管内插管，必要时使用呼吸机辅助呼吸。结果 全组无手术死亡，术后2例发生MG危象，经处理后痊愈。随访20例，失访3例，随访时间3个月～10年，缓解3例，明显改善11例，改善5例，无变化1例。其中1例胸腺瘤部分切除患者术后4个月死于肿瘤复发。结论 胸腺瘤合并MG患者除临床证实肿瘤无法切除或已胸外转移者外，其余均应手术治疗，完全切除胸腺瘤并清除前纵隔脂肪组织；正确的围术期处理是降低手术并发症及死亡率的关键。     

胸腔镜胸腺切除术治疗重症肌无力500例

目的 总结胸腔镜胸腺切除术治疗重症肌无力(MG)的经验,对比胸腺瘤和非胸腺瘤MG患者的术后效果,分析胸腔镜联合纵隔镜和单纯胸腔镜治疗非胸腺瘤MG的远期效果.方法 2001年至2011年,采用胸腔镜胸腺扩大切除术治疗MG患者500例,根据是否合并胸腺瘤和术中是否联合纵隔镜分组:胸腔镜胸腺瘤组(A组)118例,胸腔镜非胸腺瘤组(B组)301例,胸腔镜联合纵隔镜非胸腺瘤组(C组)81例.结果 全组无术中死亡.完全电视胸腔镜下完成手术495例.A组手术(128.5±77.8) min,术后24.6％患者出现肌无力危象;B组手术(111.3±31.6) min,术后11.0％患者出现肌无力危象;C组手术(145.0 ±71.6) min,术后9.9％患者出现肌无力危象.术后随访3个月至11年,A、B、C组患者完全缓解率(CSR)分别为28.7％、37.3％、36.5％.无病生存曲线示术后3年B、C组CSR高于A组,术后5年C组CSR高于B组.术后第5年C组CSR接近60％,B组为50％,而A组仅为36％.结论 胸腔镜基础上联合纵隔镜胸腺扩大切除手术清除颈部、前纵隔脂肪组织及异位胸腺更为彻底,远期效果更加理想.与非胸腺瘤MG患者相比,胸腺瘤MG患者术后远期效果较差.     

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.