结直肠癌术前vivonex替代肠道准备的临床研究

目的探讨口服vivonex可否替代结直肠癌术前肠道准备。方法结直肠癌患者40例,分vivonex组(20例)和对照组(20例),手术前后行肠道菌群分析,血浆D-乳酸、血中细菌DNA检测,观察术中肠道清洁情况和术后感染性并发症的发生率。结果两组术前双歧杆菌/大肠杆菌(B/E)比值倒置,对照组术后B/E比值(0.25±0.06)较术前(0.72±0.59)倒置更为明显,P<0.01。vivonex组术后B/E比值(1.36±0.34)较术前(0.76±0.47)显著增加,P<0.05;两组术后B/E比值比较,vivonex组较对照组显著增加(P<0.01)。术后血浆D-乳酸对照组较vivonex组显著增加(P<0.05),血中DNA阳性率(40%)、术后感染性并发症发生率(25%)对照组均高于vivonex组(25%和15%)。结论vivonex用于结直肠癌术前肠道准备可维护肠屏障功能,降低术后感染性并发症发生率。     

补充双歧三联活菌对结直肠癌术后患者免疫状况和炎性反应的影响

目的 探讨结直肠癌患者术前补充双歧三联活菌对术后免疫状况和炎性反应的影响.方法 60例患者入院后按随机数字表法分为治疗组和对照组.治疗组30例术前5 d起在常规肠内营养基础上口服双歧三联活菌：对照组30例术前肠道准备按传统方法进行.两组患者手术前3d和术后第1次自然排便（术后3～5 d）时分别留取粪便作肠道菌群分析,检测粪便SIgA;术前1 d和术后1、9 d进行免疫和炎性反应指标检测,并观察患者术后感染并发症发生情况.结果 术后治疗组患者双歧杆菌（B）/大肠杆菌（E）比值（2.01±0.36）较术前（26.53±4.22）明显下降（P＜0.05）,但仍大于1：对照组患者手术前后B/E比值（0.72±0.14和0.02±0.06）均明显低于治疗组（P＜0.05）.术前两组免疫和炎性反应指标检测结果差异无统计学意义（P＞0.05）.术后第1天,两组患者免疫球蛋白、淋巴细胞总数和粪便SIgA均下降,炎性因子均上升.术后第9天,两组患者血清IgG水平逐渐上升,但治疗组显著高于对照组（P＜0.05）,而血清IL-6和C反应蛋白水平显著低于对照组（P＜0.05）;粪便SIgA水平治疗组显著高于对照组（P＜0.05）.术后感染并发症发生率治疗组低于对照组（P＜0.05）,但术后其他并发症发生率及住院天数两组差异无统计学意义（P＞0.05）.结论 术前常规肠内营养基础上补充双歧三联活菌能改善结直肠癌患者肠道菌群失调.益于术后重建肠道菌群平衡、提高机体免疫状况和保护肠黏膜屏障功能及减轻炎性反应.     

直肠癌患者围手术期肠道菌群变化影响因素的临床研究

目的探讨围手术期不同处理因素对直肠癌患者术后肠道菌群变化的影响。方法前瞻性入组2010年7月至2011年6月间青岛大学医学院附属医院收治的64例直肠癌患者。按术前肠道准备、抗生素应用和术后禁食3个因素进行析因设计．采用随机数字表法将64例人组患者分为8组．每组8例。收集手术前后粪便标本,倍比稀释后分别涂在选择性培养基上恒温培育48h,对肠道细菌进行计数．比较各组患者手术前后菌群变化的程度。结果与术前相比．各组患者术后肠道菌群发生明显变化,表现为细菌总数、双歧杆菌、消化链球菌、乳酸杆菌、类杆菌和肠球菌明显减少,而大肠杆菌计数明显增加（P〈O．05）;且杆菌与球菌的比例（杆球比）显著紊乱。各组术后细菌总数经过析因设计方差分析显示．肠道准备、抗生素应用及术后禁食均为影响肠道菌群的主要因素（均P〈0．05）。与上述3项因素均限制组相比,抗生素未限制组术后大肠杆菌、类杆菌、肠球菌、乳酸杆菌、消化链球菌及细菌总数均下降,杆球比升高（P〈0．05）;肠道准备组术后类杆菌、消化链球菌、细菌总数及杆球比均下降（P〈0．05）;术后禁食组术后类杆菌、肠球菌、双歧杆菌、细菌总数及杆球比均下降（P〈0．05）。结论抗生素、肠道准备及术后禁饮食均可影响直肠癌患者围手术期肠道菌群在数量及比例的改变．从而导致肠道菌群失调。     

术前不同肠道准备对结直肠癌术后肠道菌群变化的影响

目的比较传统肠道准备与快速肠道准备对结直肠癌患者术后肠道菌群变化的影响。方法前瞻性人组2010年3月至2011年3月间南方医科大学南方医院收治的60例结直肠癌患者,按抓阄的方法随机分成试验组（33例,术前仅行1d的肠道准备）和对照组（27例,按传统的3d方案进行肠道准备）。分别于肠道准备前和术后第1次排粪时,留取粪便进行肠道菌群分析,并观察术后肠道菌群紊乱及感染性并发症的发生情况。结果两组患者术后均发生不同程度的肠道菌群失调,表现为双歧杆菌、乳酸杆菌等益生菌种计数较术前明显减少（P〈0．05）,且对照组较试验组下降更明显（P〈0．05）;而大肠杆菌、葡萄球菌等致病菌的计数则明显高于术前（P〈0．05）,且对照组明显高于试验组（P〈0．05）。试验组术后感染性并发症发生率为9．1％（3／33）,明显低于对照组的29．6％（8／27）（P〈0．05）。结论快速肠道准备在一定程度上可减轻术后肠道菌群的紊乱程度,并降低术后感染性并发症的发生率。     

SYBR GreenⅠ实时荧光定量PCR法分析结直肠癌患者肠道菌群变化

目的应用SYBR GreenⅠ实时荧光定量PCR法分析结直肠癌患者肠道菌群的变化,探讨肠道相关分子微生态在其发病中的作用及意义。方法根据细菌的16S rRNA基因序列设计双歧杆菌属、乳酸杆菌属和大肠杆菌的特异性引物,根据细菌的ddl基因序列设计粪肠球菌及屎肠球菌的特异性引物。收集结直肠癌患者术前粪便标本30份(结直肠癌组)及正常对照标本30份(正常对照组),提取细菌基因组DNA,应用SYBR GreenⅠ实时荧光定量PCR反应测定5种细菌的数量。结果正常对照组与结直肠癌组粪便中细菌数量分别为双歧杆菌属:9.25±0.83比4.52±0.49,乳酸杆菌属:7.45±0.37比5.46±0.12,结直肠癌组的数量明显减少(P0.05);大肠杆菌:4.68±0.32比5.82±0.47,粪肠球菌:4.95±0.24比10.60±0.30,屎肠球菌:5.03±0.43比5.74±0.16,结直肠癌组的数量明显增多(P0.05)。结论结直肠癌患者粪便中双歧杆菌及乳酸杆菌数量较正常对照明显减少,而大肠杆菌,粪肠球菌和屎肠球菌的数量较正常对照明显增多,提示结直肠癌的发生、发展与肠道菌群有一定关系。     

大肠癌术后肠道菌群变化的临床研究

目的探讨大肠癌手术后肠道菌群的变化。方法对 30例大肠癌患者于手术前后留取粪便作肠道菌群分析 ,检测血中细菌DNA ,血细菌培养 ,观察术后感染并发症。结果术后大肠杆菌和肠球菌计数均明显增加 (P <0 0 5 ) ,双歧杆菌和乳杆菌计数则明显减少 (P <0 0 5 ) ,双歧杆菌 /大肠杆菌比值较术前倒置更为显著 (0 0 2 8± 0 0 7vs.0 75± 0 4 6 ,P <0 0 1 ) ,术前血中细菌DNA和细菌培养均为阴性 ,术后阳性率则分别为 4 3% (3/30 )、7% (2 /30 ) ,术后感染并发症发生率为 30 % (9/30 )。结论大肠癌手术可引起肠道菌群失调 ,损害肠屏障功能 ,导致细菌移位 ,增加术后感染并发症 ,围手术期应重视肠道菌群的微生态调理     

手术处理对结直肠癌患者肠道菌群变化的临床研究

目的探讨结直肠癌手术处理对肠道菌群变化的影响,为临床治疗提供理论依据。方法收集手术前后结直肠癌患者粪便标本50份及正常对照标本50份,应用SYBRGreenI实时荧光定量PCR反应测定不同细菌的。结果正常对照组,手术前、后实验组粪便中细菌数量分别为双歧杆菌（8.85±0.57、5.22±0.45、0.47±0.28）、乳酸杆菌（8.06±0.654.86±0.38、3.52±0.26）,手术前、后实验组数量较正常组明显减少（P〈0.05）,以术后为甚。大肠杆菌为（5.46±0.48、6.57±0.85、4.83±0.47）,粪肠球菌为（5.98±0.44、9.76±0.67、2.38±0.14）,屎肠球菌为（4.79±0.69、6.88±0.35、1.45±0.19）,拟杆菌为（7.98±0.84、9.12±0.53、5.83±0.54）,梭杆菌为（8.12±0.78、9.67±0.82、5.41±0.59）,梭菌为（5.16±0.55、7.01±0.43、4.42±0.48）,术前实验组数量较正常组明显增多（P〈0.05）,术后实验组数量较术前明显减少（P〈0.05）。结论结直肠癌患者手术处理可引起肠道菌群失调,可能与结直肠癌的复发和发展有关,应重视围手术期肠道菌群的微生态调理。     

结直肠癌患者手术前后肠道菌群变化分析

为通过观察结直肠癌患者手术前后肠道中双歧杆菌（Bifidobacteriumspp．）、乳酸杆菌（Lactobacillus）、粪肠球菌（Enterococcus如ecalis）和拟杆菌（Bacteroidaceae）的变化情况,分析肠道菌群的改变在结直肠癌发病及治疗中的作用及意义,收集正常健康人粪便标本60份、结直肠癌患者术前及术后粪便标本各60份,应用平板活菌计数法和荧光定量聚合酶链反应（PCR）法检测粪便标本中各种菌群的数量,同时采集患者的外周血标本,应用显色法检测D-乳糖和内毒素的含量。结果显示,结直肠癌患者术前粪便中乳酸杆菌、双歧杆菌数量均比正常健康人少,P〈O．05或P〈O．01;粪肠球菌、拟杆菌数量均比正常健康人多,P〈O．05或P〈O．01。结肠癌患者术后粪便中乳酸杆菌、双歧杆菌数量进一步减少,P〈0．05或P〈0．01;粪肠球菌、拟杆菌数量进一步增多,P〈O．05或P〈O．01。结直肠癌患者血清I）I乳糖、内毒素含量比正常健康人高,P〈O．Ol,手术后其含量进一步升高,P〈O．Ol。结果表明,肠道菌群的变化与结直肠癌的发生、发展及预后有一定关系。     

加速康复外科联合益生菌对结直肠癌患者术后肠道菌群变化的影响

［摘要］ 目的 探讨加速康复外科联合益生菌对结直肠癌患者术后肠道菌群变化的影响。方法 前瞻性纳入2016年5月至2018年5月江门市中心医院胃肠外科收治的结直肠癌患者126例,将入组患者分为对照组（59例,单纯ERAS组）和实验组（67例,ERAS联合益生菌治疗组）。比较两组患者术后肠道菌群不同菌属数量的变化及菌群紊乱的分度,比较两组患者术后肠源性感染相关并发症的发生率。结果 两组患者术前均出现不同程度的菌群失调（P>0.05）,对照组患者术后以Ⅱ°菌群失调居多,而实验组患者术后主要表现为Ⅰ°的菌群失调（P=0.014）。术后实验组双歧杆菌、乳酸杆菌计数总量均高于对照组（P<0.001）。对照组术后出现腹泻、腹腔感染、吻合口漏的发生率比实验组高,但只有腹泻的发生率两组差异有统计学意义,腹腔感染和吻合口漏统计学差异不明显。两组患者术后均无出现脓毒血症。结论 结直肠癌患者围手术期予以益生菌治疗,可改善肠道微生态环境,保护肠道黏膜屏障,加速患者术后康复。     

加速康复外科联合益生菌对结直肠癌患者术后肠道菌群变化的影响

目的探讨加速康复外科联合益生菌对结直肠癌患者术后肠道菌群变化的影响。方法前瞻性纳入2016年5月至2018年5月江门市中心医院胃肠外科收治的结直肠癌患者126例,将入组患者分为对照组(59例,单纯ERAS组)和实验组(67例,ERAS联合益生菌治疗组)。比较两组患者术后肠道菌群不同菌属数量的变化及菌群紊乱的分度,比较两组患者术后肠源性感染相关并发症的发生率。结果两组患者术前均出现不同程度的菌群失调(P0.05),对照组患者术后以Ⅱ°菌群失调居多,而实验组患者术后主要表现为Ⅰ°的菌群失调(P=0.014)。术后实验组双歧杆菌、乳酸杆菌计数总量均高于对照组(P0.001)。对照组术后出现腹泻、腹腔感染、吻合口漏的发生率比实验组高,但只有腹泻的发生率两组差异有统计学意义,腹腔感染和吻合口漏统计学差异不明显。两组患者术后均无出现脓毒血症。结论结直肠癌患者围手术期予以益生菌治疗,可改善肠道微生态环境,保护肠道黏膜屏障,加速患者术后康复。     

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.