白细胞介素-1在周围神经损伤后神经再生中的作用

目的　观察白细胞介素 1(interleukin 1,IL 1)在周围神经损伤后神经再生中的作用。方法　采用 40只Wister大鼠为实验动物。在坐骨神经形成 1cm的缺损后 ,以自体颈静脉桥接 ,根据注入静脉的不同制剂分为 4组 :雪旺细胞培养液组、IL 1组、IL 1再加IL 1拮抗剂组和培养液组 (对照组 )。术后 1、3个月进行电生理和组织学观察 ,并进行对比检测。结果　术后 1个月 ,IL 1组神经轴突的再生明显好于加IL 1拮抗剂组和对照组 (F =4.0 18,P <0 .0 5 )。术后 3个月时 ,IL 1组神经轴突的再生仍好于后 2组 ,但无统计学意义。结论　IL 1有促进周围神经再生的作用。但其作用方式、注入量、注射间隔时间等仍有待于进一步的研究。     

高浓度臭氧注入猪蛛网膜下腔后对脑脊液和脊髓的影响

目的观察高浓度臭氧注入猪蛛网膜下腔后脑脊液常规、生化改变及脊髓病理形态学改变。方法小型猪8只,随机分为4组,每组2头,A组在蛛网膜下腔注射高浓度臭氧后第二天处死取材,B组在1周后处死,C组在1个月后处死,D组在3个月后处死。透视下用21G Chiba针沿L4-5棘突间隙进入蛛网膜下腔,注入10 ml 90μg/ml臭氧。分别在术前、术后30 min、1周、1个月和3个月抽取脑脊液2 ml行常规及生化检验,并进行CT、MRI检查,按照分组处死动物,取出腰段脊髓行大体及光镜下观察。结果术后实验动物均无严重的行为异常。各阶段脑脊液常规及生化检验未见明显异常改变。影像学检查未见脊髓损伤征象,术后各阶段脊髓大体及光镜下均未见明显异常改变。结论高浓度臭氧10ml以下注入猪蛛网膜下腔是安全的,该实验为临床治疗椎间盘突出症时误穿入蛛网膜下腔提供安全性依据。     

缓释bFGF胶原膜修复猪胆管缺损的实验研究

目的探讨采用缓释bFGF胶原膜修复猪胆管缺损的效果。方法中华实验用猪28只,雌雄不限,体重15～30 kg;根据处理方法不同,将其随机分为3组,其中实验组12只,空白对照组12只,正常对照组4只。正常对照组不作处理;实验组和空白对照组制备胆管壁缺损模型(长2 cm,宽1/3～2/3胆管周径)后,分别采用2.0 cm×1.0 cm×0.5 mm缓释bFGF胶原膜和空白胶原膜缝合修复。术后观察实验动物存活情况,并于术后1、2、3个月检测肝功能变化,处死动物后行大体观察;取胆管组织经HE及免疫组织化学染色,行微血管密度(microvessel density,MVD)及黏膜下腺体计数;术后3个月行经胆囊胆管胆道造影观察。结果术后实验动物均存活至实验完成。术后1个月实验组及空白对照组腹腔粘连均较严重,随着时间延长,实验组粘连较空白对照组明显缓解。肝功能检测示,除ALP在术后2、3个月实验组及空白对照组均较正常对照组显著下降(P<0.05)外,其余各指标,如谷丙转氨酶、总胆红素和白蛋白术后各时间点组间比较,差异均无统计学意义(P>0.05)。组织学及免疫组织化学染色观察示,实验组胆管腺体再生和上皮再生速度快于空白对照组,2个月即完成胆管上皮覆盖,3个月与正常对照组相似,相应组织水肿和炎性浸润均较空白对照组轻。术后1个月实验组黏膜下腺体计数及MVD值均显著高于两个对照组(P<0.05),2个月后下降并稳定于正常对照组水平;空白对照组随时间延长呈上升趋势,术后1、2个月显著低于实验组和正常对照组(P<0.05),3个月时达到并稳定于正常对照组水平。相关性分析表明,正常对照组、实验组和空白对照组术后各时间点黏膜下腺体计数与MVD之间均成正相关(P<0.01)。术后3个月造影显示,实验组、空白对照组均无胆管扩张及结石形成。结论缓释bFGF胶原膜可通过促进新生血管再生等方式促进猪胆管缺损愈合。     

椎体成形术对兔手术椎体相邻椎间盘的影响

[目的]探讨椎体成形术(vertebroplasty,VP)是否会引起兔手术椎体相邻椎间盘的退变,以及椎间盘的退变程度与聚甲基丙烯酸甲酯(polymethyl methacrylate,PMMA)用量的相关性.[方法]80只5个月龄雌性新西兰大白兔,随机选16只为正常对照组(A组),剩余的64只采用去势法建立兔骨质疏松模型后随机分为4组,设L5为手术椎体.B组(实验对照组)L5不注入任何药物;C组L5注入PMMA0.1 ml;D组L5注入PMMA0.3 ml;E组L5注入PMMA 0.5ml.每组分别于术前及术后1、3、6个月各处死4只动物,进行X线、MRI检查,通过计算椎间盘高度指数百分数(disc height Index percentage,DHIP)和MRI指数,来定量分析椎间盘退变程度.并取相邻椎间盘送病理,采用Masuda评分评估椎间盘退变程度.[结果]A、B组椎间盘的DHIP、MRI指数和Masuda评分在各个时间点均无明显变化.C、D、E组在术前及术后1个月时的DHIP、MRI指数和Masuda评分较A、B组无明显改变.第3个月时,E组椎间盘的DHIP、MRI指数较其他各组均有降低,且MRI指数和Masuda评分较A、B组有统计学差异(P＜0.05).第6个月时,D、E组椎间盘的DHIP、MRI指数和Masuda评分跟术前及术后1、3个月比较均有显著统计学差异(P＜0.05),E组的DHIP和MRI指数均明显低于A、B、C、D组.组织学退变也较A、B、C、D明显,Ma-suda评分明显高于A、B、C、D组.[结论]VP可以引起手术椎体相邻椎间盘的退变,并且椎间盘退变程度与PM-MA用量相关.     

不同浓度臭氧注入猪椎间盘后氧化效果的实验研究

目的观察低、中、高浓度臭氧注入猪正常椎间盘后不同时间段髓核组织的变化,探索既高效又安全的臭氧浓度,为临床注射臭氧治疗腰椎间盘突出症提供实验依据。方法小型猪10只,于透视下用21G Chiba针刺入猪腰椎间盘中心部,经穿刺针注入臭氧3 ml,重复3次,在椎间孔处注入5 ml于椎旁组织内。其中L5~6,L4~5,L3~4和L2~3分别注入臭氧浓度为90μg/ml,60μg/ml,30μg/ml及无菌空气,L6~S1不进行任何干预,为空白对照。分别在注射后1天、1周、1个月、2个月和3个月后处死动物各2只,在相同时间点进行CT及MR检查。处死后取出椎间盘及椎旁肌肉标本,作大体和光镜下观察,对髓核氧化及退变程度进行量化评分。结果术后3个月内髓核氧化及退变程度评分随时间推移逐渐增高,臭氧浓度越高,增高趋势越明显。术后MRI随访1个月时高浓度组髓核信号T2加权开始减低,其他组不明显。术后2个月注射组所有椎间盘信号均减低,臭氧浓度越高,信号减低越明显。光镜下1天出现髄核细胞的肿胀变性,1周髄核细胞出现与注射浓度正相关的体积缩小和基质含量减少,此后胶原纤维增生,逐渐取代髄核组织,在3个月时,高浓度组髄核干涸的程度,继发纤维化均较中、低浓度组高,并且出现相邻椎体骨性融合。中、高浓度椎旁肌肉注射1周时出现肌纤维肿胀变性及间质黏液变性。结论臭氧浓度越高,髄核的干涸效果越明显,椎间盘退行性变也越明显。高浓度臭氧盘内注射,3个月后椎间盘退变严重,不宜进行临床应用,椎旁肌肉内不宜注射中、高浓度臭氧。     

异种膀胱无细胞基质替代尿道的研究

目的探讨异种膀胱无细胞基质(ACM)管状替代尿道的可行性。方法19只成年雄性新西兰白兔分成3组：A组3只，为假手术对照组；B组10只，切除一段1．0cm尿道；C组6只，切除一段3．5～4．0cm尿道，之后应用已经事先制备好的异种膀胱ACM制成相当长度的管状替代被切除的尿道。术后1、2、4、8、16周动态观察替代尿道的尿道上皮、平滑肌和血管的再生情况。结果所有实验动物在术后7d拔除尿管后都恢复了自主排尿，没有排斥、尿瘘、感染等并发症发生。组织学检查显示实验组术后2周尿道上皮再生良好，4周完全覆盖尿道内腔，术后8周平滑肌见于近吻合口处，平滑肌生长缓慢，观察期内未能覆盖全长尿道。尿道造影未见明显尿道狭窄和憩室。结论异种膀胱ACM是一种良好的尿道修复和替代的材料。     

老年骨质疏松性胸腰椎压缩性骨折采用椎体成形术联合中药治疗疗效观察

目的探讨老年骨质疏松性胸腰椎压缩性骨折患者采用椎体成形术联合中药治疗疗效。方法将2014年6月至2017年6月医院收治的75例老年骨质疏松性胸腰椎压缩性骨折患者按照治疗方法分组为对照组与观察组,分别为38例、37例。其中对照组采用后路经皮椎体成形术治疗;观察组于对照组治疗基础上采用中药补肾壮骨汤口服。记录两组患者术前、术后3个月、6个月疼痛程度,检测两组患者术前、术后3个月、6个月L_(1～4)骨密度,采用Oswestry功能障碍指数评价两组患者术前、术后3个月、6个月生活质量,记录两组术后再骨折情况,评价临床疗效。结果两组患者术后3个月、6个月VAS评分、Oswestry指数较术前明显下降,且术后6个月低于术后3个月,观察组术后3个月、6个月VAS评分、Oswestry指数明显低于对照组,P0.05。两组患者术后3个月、6个月L_(1～4)骨密度明显高于术前,术后6个月明显高于术后3个月,观察组术后3个月、6个月时L_(1～4)骨密度明显高于对照组,P0.05。观察组术后6个月内再骨折率为0.0%,明显低于对照组15.79%(6/38),χ~2=6.35,P=0.01;观察组总有效率明显高于对照组,P0.05。结论中药汤剂联合后路椎体成形术治疗老年骨质疏松性胸腰椎压缩性骨折患者疗效显著,值得推广。     

聚丙烯酰胺水凝胶注入兔体后组织病理学与免疫组化的动态观察

目的动态观察聚丙烯酰胺水凝胶(奥美定)注入兔体后,对组织细胞形态学及Bcl-2、P53、HsP70、PCNA表达的影响。方法将24只新西兰白色家兔分为三组,注入奥美定5ml/kg的10只为Ⅰ组,注入奥美定10ml/kg的11只为Ⅱ组,未注入任何材料的3只为对照组,在相同的饲养条件下,分别于注入3、6、14个月时处死白色家兔,即刻切取标本切片,经10%甲醛固定后,石蜡包埋,HE及免疫组化染色观察。结果24只新西兰白色家兔中有6只兔(注入奥美定的4只,对照组的2只),分别观察到支气管肺炎、支气管黏膜鳞状上皮化生、肝点状坏死、间质性心肌炎等病理改变;其余18只兔均无明显改变。免疫组化Bcl-2、p53均为阴性,Hsp70、PCNA仅在极少数的肝、肾小管上皮细胞有阳性表达。结论奥美定注入兔体后动态观察3、6、14个月时处死,经病理形态学及免疫组化检测表明是安全的。     

脱细胞异体阔筋膜与自体网膜修补肾损伤的对比研究

目的 探讨异体阔筋膜细胞外基质(ECM)作为肾损伤修补材料的效果.方法 24只实验犬随机分3组:组1,异体阔筋膜ECM修补,10只;组2,自体大网膜修补,10只;组3,异体阔筋膜修补,4只.组1、2于术后1、2周及术后1、2、4个月取材,组3于术后2周、2个月时取材,每组每次2只.术前及术后行血红蛋白检查,术中估算出血量,术前及处死动物前行血清.肾素及SCr检查,并分别测定左、右肾的肌酐清除率,处死动物后切取双侧.肾脏分别称重并于修补局部取材行光镜及扫描电镜检查.结果 术中出血量组2为(28.3±1.8)g,明显高于组1[(18.0±2.7)g]及组3[(17.7±3.1)g],差异有统计学意义;各组各时段术后血红蛋白、SCr及血清肾素检查与术前相比差异无统计学意义;各组各时段手术修补肾(左肾)与对侧正常肾(右肾)肌酐清除率相比以及双侧肾脏质量相比差异均无统计学意义.术后大体标本、光镜及电镜检查显示:组1,术后各时段补片与周围组织均无明显粘连,且补片大小形状无明显改变,无皱缩现象.随时间推移,补片逐渐变薄形成接近正常的肾包膜结构.补片下方的肾皮质在术后各时期均无明显炎性细胞浸润.组2,取材时游离患肾十分困难,随时间延长肾创面有收缩现象,创面逐渐形成包膜样结构,但较薄且与其上的大网膜无法分离.组3,术后补片与周围组织粘连明显,肾创面有明显收缩现象,局部炎性细胞浸润明显,免疫反应严重.结论 异体阔筋膜ECM可作为理想的肾修补材料.     

牙列缺损合并重度牙周炎患者植牙同期CGF联合引导骨再生术治疗的疗效研究

目的研究牙列缺损合并重度牙周炎患者植牙同期浓缩生长因子(CGF)联合引导骨再生术治疗的疗效。方法选取本院于2016年9月到2017年9月收治的62例牙列缺损合并重度牙周炎患者进行研究,按照随机数字表法随机分成治疗组和对照组,每组各31例。对照组单纯行植牙手术,治疗组则在植牙同期应用CGF联合引导骨再生术进行治疗。观察并比较两组患者术后1、3、6、12个月种植体周改良龈沟出血指数(m BI)、探诊深度及术前、术后6、12个月的牙槽嵴高度、宽度变化情况。结果治疗组术后1个月、3个月、6个月、12个月的mBI均显著低于对照组,两组比较差异显著(P0.05)。治疗组术后1个月、3个月、6个月、12个月的探诊深度明显低于对照组,两组比较具有统计学意义(P0.05)。两组术后6个月和术后12个月的牙槽嵴高度和宽度均较术前显著增加,且治疗组的牙槽嵴高度和宽度均较对照组增加更为显著(P0.05);但两组术后6个月和12个月比较两者均无统计学意义(P0.05)。结论牙列缺损合并重度牙周炎患者植牙同期应用CGF联合引导骨再生术治疗的疗效显著,可有效减少mBI和探诊深度,增加缺损部位骨量,可在临床推广应用。     

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.