胫骨近端截骨联合膝关节后外侧重建治疗儿麻后遗症严重膝内翻

[目的]胫骨近端截骨术联合采用股二头肌长头腱重建膝关节后外侧结构并探讨其在儿麻后遗症严重膝内翻畸形矫正中的临床效果。[方法]2011年8月~2015年8月对7例儿麻后遗症严重膝内翻畸形患者,一期均行胫骨近端截骨术,二期取内固定时,同时采用股二头肌长头腱重建膝关节后外侧结构。[结果]一期胫骨近端截骨术后均随访20~48个月,平均25.40个月。在非负重状态下,所有胫骨内翻畸形均矫正;在负重状态下,术前膝内翻角度30°~45°,平均37.10°,术后膝内翻角度8°~14°,平均11.70°,矫正角度20°~31°,平均25.4°,所有膝内翻畸形较术前有改善。截骨端愈合时间3~5个月,平均3.50个月。二期膝关节后外侧重建术后随访12~24个月,术后12个月,完全伸膝位无内翻不稳;屈膝30°,Ⅰ度内翻不稳1例;屈膝30°,患侧小腿外旋较健侧增加1例。术后24个月,患膝后外侧结构的稳定性无明显改变,下肢力线恢复满意。[结论]胫骨近端截骨术可以纠正胫骨内翻畸形,改善膝内翻畸形;采用股二头肌长头腱重建膝外侧副韧带和腘肌腱,能够有效恢复膝关节后外侧结构的稳定性;两者联合应用在儿麻后遗症严重膝内翻畸形矫正中可以取得较好疗效。     

两种截骨术治疗膝骨关节炎合并膝内翻的比较

目的观察对比两种胫骨高位截骨术治疗膝骨关节炎合并膝内翻畸形的临床疗效。方法分别采用胫骨高位截骨连同腓骨中段截骨和胫骨高位截骨连同腓骨小头截骨纠正膝内翻畸形，术后5年以内及5年以后者按同一标准对其疗效进行评价。结果随访结果按窦宝信标准进行评估。胫骨高位截骨连同腓骨中段截骨5年以内及5年以后随访的优良率分别为84．6％、69．2％；胫骨高位截骨连同腓骨小头截骨5年以内及5年以后随访的优良率分别为81．7％、68．1％。两种手术方法的临床优良率基本相似。胫骨高位截骨连同腓骨小头截骨手术时间、手术切口长度、出血量显著低于胫骨高位截骨连同腓骨中段截骨。结论胫骨高位截骨治疗膝关节骨关节炎合并内翻畸形临床疗效确切，远期疗效有下降趋势。胫骨高位截骨连同腓骨小头截骨具有手术创伤小、出血少、手术时间短、腓深神经损伤发生率低等优点。     

膝外摆步态对膝内翻患者股骨-胫骨角及胫股关节外侧间隙的影响

目的探讨膝外摆(lateralthrust)步态对膝内翻患者股骨-胫骨角及胫股关节外侧间隙的影响及其临床意义。方法膝内翻伴膝外摆步态患者44例,男10例,女34例;年龄31～60岁,平均41岁。分别在静态单足和双足站立位膝关节正位X线片上测量股骨-胫骨角度数和胫股关节外侧间隙宽度。双足站立位模拟步态周期中双支撑相,即膝外摆早期;单足站立位模拟步态周期中单支撑相,即膝外摆后期,两种体位X线片上的股骨-胫骨角及胫股关节外侧间隙的改变反映了膝外摆过程中胫骨和股骨对应关系的改变。结果单足较双足支撑相的股骨-胫骨角增大(角度分别为188.50°±4.48°和185.50°±4.46°),胫股关节外侧间隙增宽[距离分别为(9.92±0.86)mm和(7.70±0.78)mm]。结论膝外摆步态中股骨-胫骨角增大、胫股关节外侧间隙增宽,使膝内翻患者的膝内侧间室承重增加,膝外侧稳定结构不稳,最终可能导致膝内翻加重及发生内侧间室骨关节炎。     

Koshino胫骨高位截骨结合外固定支架治疗膝内侧髌股型骨关节炎

[目的]介绍Kosh ino胫骨高位截骨结合外固定支架在膝内侧髌股型骨关节炎治疗中的应用。[方法]自1995年1月~2003年1月,笔者采用Kosh ino胫骨高位截骨结合外固定支架治疗36例42膝骨关节炎。全部病例均为内侧髌股型骨关节炎。术前术后测量胫股角,关节功能评估采用日本横滨市立大学膝关节功能评分法。术后2~3周扶拐部分负重,平均10~14周拆除外固定支架。[结果]术后平均随访(18.2±6.7)个月,术后均无伤口感染,关节血肿,关节粘连或骨不连等。但有6例外固定支架钉道感染,有7例轻度深静脉栓塞。术后3~4个月完全恢复步行。膝关节功能评分改变由术前(55±8.2)分至术后(90±7.4)分,胫股角由术前(184.3±5.8)°至术后(170.5±2.2)°。[结论]Kosh ino胫骨高位截骨结合外固定支架是治疗60岁以下膝内侧髌股型骨关节炎的有效方法。     

关节镜下清理胫骨高位截骨骑缝钉固定术治疗膝骨关节炎

[目的]探讨关节镜下清理及应用记忆合金骑缝钉固定的胫骨高位截骨术治疗膝关节骨关节炎的手术方法、手术适应证及疗效。[方法]自1999年3月~2003年5月应用记忆合金骑缝钉固定的胫骨高位截骨术结合关节镜下清理术治疗膝关节骨关节炎34例(42膝),男6例(8膝),女28例(34膝),年龄42~67岁(平均54.2岁)。随访1 a 4个月~3 a 8个月(平均2 a 11个月)。关节镜下发现:髌内侧滑膜皱襞10例;内侧半月板损伤12例;外侧半月板损伤6例;关节软骨损伤20例;关节内游离体7例;髁间窝狭窄9例,关节镜下清理后进行胫骨高位截骨,不显露腓总神经,闭合楔形截骨,行改良胫骨结节前置,保持内侧骨膜的稳定性,应用记忆合金骑缝钉固定。[结果]膝关节疼痛基本消失,关节功能基本不受影响,膝内翻畸形得到矫正。膝关节评分术前为(53.71±6.7),术后为(91.02±7.7),两者比较有显著性差异(P<0.01),优良率为95.24%。术后并发症少,能早期进行功能锻炼,无需再次取出内固定。[结论]关节镜下清理及应用记忆合金骑缝钉固定的胫骨高位截骨术治疗膝关节骨关节炎,治疗关节内病变,具有操作简便,固定牢固,神经、血管损伤发生率低,可早期负重,早期进行功能锻炼,促进骨质愈合,组织相容性好,无须二次手术取出等优点。     

胫骨内侧高位楔形截骨治疗膝关节骨性关节炎

目的　探讨胫骨内侧高位楔形截骨治疗伴有膝内翻畸形的膝关节骨性关节炎的疗效。方法　对 1996年 7月～ 1999年 9月 ,采用胫骨内侧高位楔形截骨结合髂骨植骨钢板内固定术治疗 19例 (2 6膝 )膝关节骨性关节炎伴膝内翻畸形 ,病程 1～ 2 4年 ,平均 6 .3年 ,按 Ahlback分类 度 10膝 , 度 9膝 , 度 6膝 , 度 1膝。患者术前、术后 8周和术后 2年进行患肢全长 X线片检查 ,测量胫股角、胫骨角、股骨角、胫股关节面切线夹角及胫股内侧关节间距大小。按膝关节功能评定标准 ,评定术后膝关节功能恢复情况。　结果　 19例 (2 6膝 )术后获随访 2 4～ 4 5个月 ;术后 2年随访膝关节功能自 (4 8.6± 16 .6 )分增至 (81.7± 14 .8)分 ,胫股内侧关节间距自 (2 .2± 1.6 ) mm增至 (4 .9± 1.5 ) mm,胫股关节面切线夹角自 7.4°± 3.1°减少至 1.7°± 3.1°。植骨愈合满意 ,无膝内翻复发。术中出现关节内骨折 1例 ;皮肤感染 2例。结论　胫骨内侧高位楔形截骨结合植骨钢板内固定 ,可作为治疗伴有膝内翻畸形的膝关节骨性关节炎的有效方法之一。     

内侧撑开高位胫骨截骨术联合调整胫骨平台后倾角治疗屈曲受限型膝内翻骨关节炎的早期疗效

目的探讨内侧撑开高位胫骨截骨术联合调整胫骨平台后倾角治疗屈曲受限型膝内翻骨关节炎的早期疗效。方法回顾性分析2014年1月—2016年7月收治并符合选择标准的18例(18膝)屈曲受限型膝内翻骨关节炎患者临床资料。其中,男6例,女12例;年龄48~64岁,平均54.9岁。左膝8例,右膝10例。膝内翻7.45~15.52°,平均10.63°。按照Kellgren-Lawrence分级标准:Ⅱ级4例,Ⅲ级14例。术中采用内侧撑开高位胫骨截骨矫正膝内翻,同时调整胫骨平台后倾角以改善屈曲受限。结果术中截骨厚度为10~19 mm,平均14.91 mm;手术时间1.2~2.0 h,平均1.4 h。术后切口均Ⅰ期愈合。患者均获随访,随访时间l.0~2.5年,平均1.5年。末次随访时,患者膝关节屈曲角度较术前增加,Lysholm评分、美国特种外科医院(HSS)评分、国际膝关节文献委员会(IKDC)评分均较术前明显提高,比较差异有统计学意义(P0.05)。X线片复查示,截骨均愈合,愈合时间3~7个月,平均3.6个月。末次随访时,下肢力线通过胫骨平台相对位置以及胫骨平台后倾角均较术前明显改善,比较差异有统计学意义(P0.05)。结论内侧撑开高位胫骨截骨术联合调整胫骨平台后倾角治疗屈曲受限型膝内翻骨关节炎,可有效改善膝关节屈曲角度,获得良好早期疗效。     

胫骨内侧高位楔形截骨治疗膝内翻畸形的临床疗效观察

[目的]探讨胫骨内侧高位楔形截骨治疗膝内翻畸形的疗效.[方法]1998年7月～2007年10月,采用胫骨内侧张开式高位楔形截骨结合植骨钢板内固定术治疗膝内翻畸形共49例72个膝关节.患者术前、术后8周、术后1.5年行患肢全长X线片检查,测量胫股角、胫股内侧关节间距大小.按HSS膝关节功能评定标准评定术前、术后膝关节功能.[结果]72膝术后随访18～128个月,平均58个月;胫股角术前187.5°±5.3°,术后172.6°±3.6°,膝关节功能由(47.2±17.6)分增至(83.2±15.3)分,胫股内侧关节间距由(2.4±1.2)mm增至(4.3±1.2)mm.植骨均愈合满意,无膝内翻复发.术后疼痛缓解及行走功能改善显著.术中出现关节内骨折3例,无神经血管损伤.术后皮肤感染切口延迟愈合2例.[结论]胫骨内侧高位楔形截骨结合植骨钢板内固定术,可作为治疗膝内翻畸形的有效方法之一.     

胫骨高位截骨手术并发症23例次分析

[目的] 探讨胫骨高位截骨手术并发症的发生情况，并提出预防和治疗措施。[方法]2000年1月～2004年10月采用胫骨高位截骨术治疗膝骨关节炎合并内翻畸形患者126人，21人发生手术并发症，男4例，女17例；年龄48～64岁，平均61岁。术前拍摄站立膝关节正位X线片，测量股骨一胫骨角，计算截骨角度，采用外侧闭合胫骨高位截骨术矫正膝内翻畸形。[结果] 术后随访6～12个月，平均7．5个月。共21名患者发生各类并发症23例次．发生率为16．7％。其中发生胫骨骨折4例，腓总神经麻痹3例，出现深静脉血栓形成5例，膝内翻复发病例6例，内固定失败4例（其中2例合并膝内翻复发），感染1例。[结论] 降低胫骨高位截骨手术并发症需要术者熟悉局部解剖和精确的术前设计，提高手术技巧及完善的围手术期护理。     

胫骨高位外翻截骨并截骨远端前置内移术后胫骨内旋

目的观察胫骨高位外翻截骨并截骨远端前置内移术后的胫骨扭转角和足前进角的变化,探讨胫骨内旋对膝关节生物力学的影响及临床意义。方法膝内翻骨性关节炎并髌股关节炎患者24例(30膝)行胫骨高位外翻截骨并截骨远端前置内移术,男5例7膝,女19例23膝;年龄49～55岁,平均53岁。分别于术前和术后6个月～2年以足印迹法测量患侧足前进角,同时于术前和术后行CT扫描,测量患侧胫骨扭转角。采用t检验对术前、术后两组数据进行统计学分析。结果测量数据显示术前患侧足前进角为8.95°±2.99°,术后6个月时为-2.23°±4.11°;术前胫骨扭转角为33.77°±8.12°,术后为21.27°±8.48°。统计学分析显示足前进角和胫骨扭转角手术前、后差异有统计学意义(P<0.05)。术后胫骨扭转角比术前减小12.50°±2.60°,术后足前进角比术前减小11.08°±2.59°,两者比较差异无统计学意义(P>0.05)。结论胫骨高位外翻截骨并截骨远端前置内移术使胫骨内旋和足前进角减小,影响手术的效果及骨性关节炎病情的进展。     

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.