急性颈髓损伤并低钠血症的临床分析

目的:探讨急性颈髓损伤并低钠血症患者血钠浓度与颈髓损伤平面、程度的关系,观察低钠血症治疗效果.方法:回顾分析2002年1月～2007年12月我院收治的256例急性颈髓损伤并低钠血症患者资料,伤后第1天入院179例,第2天入院77例.高位颈髓(C4及C4以上)损伤101例,其中完全性颈髓损伤者59例,不完全性颈髓损伤者42例;低位颈髓(C4以下)损伤155例,其中完全性颈髓损伤者67例,不完全性颈髓损伤者88例.均于入院后第1、3、5天清晨空腹抽取静脉血查血钠,取其平均值,统计分析低血钠程度与颈髓损伤平面、程度的关系,观察低钠血症的治疗效果.结果:130mmol/L≤血钠＜135mmol/L者(轻度)96例,120mmol/L≤血钠＜130m01/L者(中度)122例,＜120mmol/L者(重度)38例.高位颈髓损伤者中,完全性损伤者血钠为117.33±4.52mm01/L.不完全性损伤者为125.49±3.74mmol/L;低位颈髓损伤者中,完全性损伤者血钠为123.67±3.81mmol/L,不完全性损伤者为131.9±4.85mmol/L,同一损伤部位完全性损伤者的血钠浓度与不完全性损伤者比较有显著性差异(P＜0.05),同一损伤程度高位损伤者与低位损伤者比较有显著性差异(P＜0.05).218例轻、中度低钠血症患者经治疗血钠完全恢复正常,38例重度低钠血症患者中9例因合并高热、感染、呼吸衰竭死亡.结论:急性颈髓损伤患者低钠血症的程度与颈髓损伤平面、程度有关,且血钠浓度越低,患者预后越差,病死率越高.     

急性完全性颈髓损伤患者的水电解质紊乱及相关内分泌变化

目的：研究急性完全性颈髓损伤患者继发的水电解质紊乱及有关内分泌的变化,探讨其发生机制。方法：颈髓损伤组28例,对照组18例,观测其水电解质代谢及血压,心率等变化,放免检测血浆肾素活性（PRA）,血管紧张素Ⅱ（AⅡ）,醛固酮（ALD）及抗利尿激素（ADH）的浓度。结果：颈髓损伤组92．9％可出现低钠血症,此外还有多尿,尿钠排出增多,血压降低,心率减慢以及液体入量低于尿量（P＜0．05）,体 液代谢呈负平衡等表现,颈髓损伤组PRA和血浆ALD及ADH浓度均低于对照组,结论：低钠血症是急性完全性颈髓损伤常见的并发症,其发生机制可能与颈髓损伤后交感神经系统抑制,使肾素－血管紧张素－醛固酮系统功能低下,继而肾脏排钠增多有关。     

急性颈脊髓损伤并发低钠血症的发病机制、治疗与预防

目的探讨急性颈脊髓损伤并发低钠血症的发病机制、治疗方法及预防措施。方法自2002—01—2012～12诊治急性颈脊髓损伤并发低钠血症179例。结果治疗1个月后各项指标与住院时相比较,血压、心率升高;24h尿量减少不明显（P〉0．05）;血钠、血浆渗透压、尿渗透压值升高;尿钠减少（P〈0．05）。出院时较治疗1个月时各项指标相比较,心率升高,血压无明显变化（P〉0．05）;尿量明显减少,血钠值升高,尿钠明显减少（P〈0．05）;血浆渗透压、尿渗透压值升高。结论急性颈脊髓损伤合并低钠血症的影响因素较多,发病机制为SIADH及CSWS,治疗时要鉴别,并可针对各种因素桌预防．减少低钠血症发毕率．     

急性颈脊髓损伤并发低钠血症的机制及治疗分析

目的 :探讨急性颈脊髓损伤患者并发低钠血症的病因、发病机制和治疗方法。方法 :自2005年1月至2010年7月收治严重创伤导致急性颈脊髓损伤伴高位截瘫并发低钠血症患者57例,男46例,女11例;年龄26～69岁,平均39.5岁;颈椎骨折或脱位55例,无骨折或脱位型脊髓损伤2例;完全性损伤28例,不完全性损伤29例。神经功能损害按ASIA分级:A级28例,B级25例,C级4例。每日监测心率、血压、尿量、血钠,诊断低钠血症后即开始静脉补液、补钠,每隔2 d检测尿钠、血浆渗透压、尿渗透压,根据监测结果及治疗反应判断低钠原因是由脑性盐耗综合征(CSWS)还是由抗利尿激素不适当分泌综合征(SIADH)引起,前者继续静脉补液、补钠,后者严格限水同时静脉补钠直至低钠纠正。对治疗前后血钠等指标进行统计学分析。结果:57例中诊断CSWS者42例,SIADH者15例。治疗3周后所有患者的心率、血钠、血渗透压有明显回升(P<0.01),血压、尿渗透压升高,尿钠减少(均P<0.05),尿量未见明显减少(P>0.05)。出院时与治疗3周比较,心率、血浆渗透压、尿渗透压进一步回升,尿量减少,尿钠进一步减少(P<0.05),血压无明显改变(P>0.05)。结论:急性颈脊髓损伤后并发低钠血症受多因素影响,发病机制主要为脑性盐耗综合征(SCWS)及抗利尿激素不适当分泌综合征(SIADH),治疗时应注意鉴别,根据不同病因采取补液或限液治疗。     

急性颈髓损伤后低钠血症发生机制及相关因素

[目的]探讨急性颈髓损伤后低钠血症的发生机制、相关因素及临床诊治原则.[方法]检测52例急性颈椎损伤后连续10 d的空腹电解质、血压、出入量的情况,根据Frankel评分标准,利用统计学方法,比较分析损伤平面、损伤程度等因素对低钠血症的影响,分析平均动脉压及24 h出入量的变化情况及与低钠血症的关系.[结果] 52例患者中,颈髓损伤38例,其空腹血钠值为(134.7±5.13)mmol/L,血压为(101.4±5.21/78.6±4.81) mmHg(1 mmHg=0.133 kPa),24 h入量为(5 810 ±493.18) ml,出量为(5 450±497.21) ml.无颈髓损伤的14例,其空腹血钠值为(139.8±2.18) mmol/L,血压为(127.2 ±2.81/84.6 ±3.42) mmHg,24 h入量为(2 890±255.82) ml,出量为(2 580±214.99) ml.伤后低钠血症的出现时间是5.2～8.3 d.[结论]低钠血症的严重程度与颈髓损伤的严重程度呈正相关,而与颈椎损伤节段无明显相关性.颈髓损伤越严重的患者,往往伴随严重的低血压,同时低钠血症也非常严重.在颈髓损伤患者的24 h出量和入量明显增加.     

急性颈髓损伤后的低钠血症

[目的]探讨急性颈髓损伤后低钠血症的病因、发病机制、诊断和治疗。[方法]回顾性分析2004年-2006年收治的急性颈髓损伤后低钠血症患者15例的临床资料。[结果]全组患者入院24—72h内血钠低于130mmol／L，其中5例低于120mmol／L。14例尿钠40—68mmol／L，1例尿钠为148mmol／L；尿渗透压420～980mmol／L，12例患者经适当的补盐和限制水摄入量治疗，低钠症状2～3周内改善；2例发热患者因发热不能严格限制水摄入，其中1例2个月后恢复，另1例失访；1例患者补盐限水后病情加重，调整治疗方案后恢复。[结论]颈髓损伤越重，损伤后低钠血症发生率越高；颈髓损伤后低钠血症多由抗利尿激素分泌异常综合征引起；血钠浓度，血、尿渗透压等是诊断依据；适当补充钠盐和液体量是有效的治疗方法。     

急性完全性颈髓损伤并发低钠血症的早期有效防治

目的探讨急性完全性颈髓损伤后并发低钠血症的有效预防与治疗。方法采用前瞻性方法,选择自2013-01—2015-05诊治的急性完全性颈髓损伤81例,入院后随机分为2组,A组40例入院后根据体重(以kg为单位)每日需钠量立即给予1/3~1/2量口服补钠,发现低钠血症后给予静脉补钠,以30 ml/h的速度静脉滴注,并根据尿量限制液体入量。B组41例入院后不口服补钠,在发现低钠血症后再行静脉补钠。结果 42例(51.9%)发生低钠血症,其中A组15例(37.5%),B组27例(65.9%);A组低钠血症发生率明显低于B组,差异有统计学意义(χ2=6.520,P=0.011)。发生低钠血症时间距伤后3~15 d,平均9 d;低钠血症持续时间11~25 d,平均18 d。A组意识障碍发生率(χ2=4.419,P=0.036)、血氧饱和度降低发生率(χ2=4.125,P=0.042)、非心源性肺水肿水泡痰发生率(χ2=5.239,P=0.022)明显低于B组,差异有统计学意义(P0.05)。结论急性完全性颈髓损伤可并发严重低钠血症,在颈髓损伤后早期采取预防性干预措施,早期发现及时纠正低钠血症对于改善预后具有极其重要的意义。     

完全性颈脊髓损伤患者早期发生低钠血症的多因素分析

目的探讨导致急性完全性颈脊髓损伤患者早期出现低钠血症的相关因素。方法回顾性分析2010年1月~2015年12月完全性颈脊髓损伤患者49例临床资料。以连续2次(间隔24 h)血钠135 mmol/L为低钠血症的诊断标准,合并低钠血症的26例为低钠血症组,未合并低钠血症的23例为对照组。对年龄,性别,颈脊髓损伤最高节段、损伤程度,是否使用糖皮质激素治疗,是否合并神经源性休克,平均每日尿量,平均每日液体平衡量,转入危重医学科时血钠水平和血浆白蛋白水平共10项指标进行单因素分析,单因素分析有统计学意义(P0.05)的指标再进行logistic逐步回归分析。计量资料单因素分析有统计学意义的指标通过绘制ROC曲线确定其最佳临界点。结果单因素分析中,2项指标在2组间有统计学差异(P0.05),低钠血症组患者低钠血症发生前神经源性休克发生率为57.7%(15/26),对照组为26.1%(6/23)(χ~2=6.516,P=0.011);低钠血症组患者平均每日尿量(2225±389)ml,对照组(1936±289)ml(t=2.924,P=0.005)。logistic逐步回归分析显示这两项因素均为完全性颈脊髓损伤患者早期发生低钠血症的独立影响因素(OR=13.708、0.996,P=0.004、0.002)。ROC曲线显示平均每日尿量的最佳临界点为2331 ml。结论并发神经源性休克与平均每日尿量2331 ml为完全性颈脊髓损伤患者早期发生低钠血症的独立影响因素。     

颈髓损伤患者低渗血症的原因及治疗

目的：探讨急性颈髓损伤后低渗血症的相关因素及治疗方法.方法：1998年10月～2002年2月共收治114例急性颈髓损伤患者,其中完全性颈髓损伤患者42例（A组）;不完全性颈髓损伤72例（B组）;同期收治的不伴颈髓损伤的其它损伤患者41例（C组）.测定各组患者的血浆渗透压、Na^＋、K^＋、Cl^-、Ca^2＋、二氧化碳结合力（CO2CP）、血糖（Glu）、血尿素氮（Bun）、血浆蛋白质总量（TP）、白蛋白（ALB）及球蛋白（GLB）含量.对42例完全性颈髓损伤患者中35例严重低钠血症患者（血钠=120～125mmol/L）20例每天采用3%氯化钠盐水400ml静脉点滴（D组）,15例每天采用3%氯化钠盐水400ml加血浆200ml静脉点滴（E组）进行1周治疗.结果：A、B、C三组间血浆渗透压、Na^＋、Cl^-、TP及ALB、GLB含量存在显著性差异（P＜0.05）.D、E组间治疗效果存在显著性差异（P＜0.05）,E组优于D组.结论：急性颈髓损伤易并发低渗血症,其发生率与损伤的程度、低钠及低蛋白有关.同时补充盐和血浆治疗效果较好.     

不同程度颈脊髓损伤后低钠血症的临床分析

 目的回顾性总结急性颈脊髓损伤后低钠血症的发生特点,并分析其可能的发生原因,以及脊髓损伤严重程度、性别、年龄等因素对血钠变化的影响。方法研究对象为2005年6月至2011年3月急诊收治的一组颈椎外伤患者,排除合并颅脑外伤及慢性疾病的患者,入选病例分为完全性脊髓损伤组、不完全性脊髓损伤组及无神经功能障碍组,回顾性分析各组病例的血钠变化情况。结果入选病例共102例,男83例,女19例;年龄17~68岁,平均45.6岁。完全性脊髓损伤组23例,不完全性脊髓损伤组60例,无神经功能障碍组19例。共发生低钠血症共39例,完全性脊髓损伤组15例(65%),不完全性脊髓损伤组23例(38%),无神经功能障碍组1例(5%)。低钠血症发生率在三组间两两比较,差异有统计学意义,完全性脊髓损伤组低钠血症的发生率明显高于不完全性脊髓损伤组和无神经功能障碍组。Logistic逐步回归分析结果显示低钠血症与患者脊髓损伤程度有明确相关关系,而与患者的年龄、性别、脊髓损伤节段无相关关系。结论急性颈脊髓损伤后具有较高的低钠血症发生率,虽然影响钠盐平衡的因素及相互作用非常复杂,但颈脊髓损伤致自主神经功能障碍、神经内分泌功能异常以及血液动力学改变可能是导致颈脊髓损伤后电解质系统异常的重要原因。     

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.