肝硬变肝组织H1和H2受体的实验与临床研究

目的：了解肝硬变大鼠和病人肝组织中H1和H2受体的变化。方法：光学放射自显影术。结果：大鼠肝组织受体密度（每1000μm^2银粒计）正常／肝硬化H1受体：肝细胞346±32／117±18（P＜0．01）；肝静脉277±18／27±5（P＜0．01）。肝动脉31±7／12±3（P＜0．05）；门静脉25±11／16±4（P＜0．05）；H2受体：肝细胞289±21／168±24（P＜0．01）；肝动脉235±29／154±25（P＜0．05）；门静脉230±28／148±18（P＜0．05）；肝静脉261±36／141±18（P＜0．01）。病人对照组／肝硬化H1受体：肝细胞69±19／63±15（P＞0．05）；肝动脉41±7／35±5（P＞0．05）；门静脉39±5／34±7（P＞0．05）；肝静脉36±8／35±5（P＞0．05）。H2受体：肝细胞512±38／168±23（P＜0．01）；肝动脉175±26／56±17（P＜0．01）；门静脉166±18／52±15（P＜0．01）；肝静脉313±2／239±41（P＜0．01）。结论：大鼠以H1受体占优势，人以H2受体为主；肝硬化大鼠及病人肝组织的H1、H2受体明显低于对照组。     

阿霉素肾病大鼠肾皮质nephrinmRNA的表达及来氟米特对其表达的影响

目的：观察阿霉素肾病大鼠肾皮质nephrin mRNA的表达及来氟米特对其表达的影响，探讨nephrin在蛋白尿发生发展中的作用以及来氟米特治疗肾脏病的可能机制。方法：建立阿霉素肾病模型，第4周进一步将模型组分为治疗组和非治疗组，治疗组给予来氟米特管饲。应用光镜、电镜观察不同时期（第2、4、6、8周）各组大鼠肾组织的病理改变；BCA法检测尿蛋白排泄量；半定量RT—PCR的方法检测肾皮质中nephrin mRNA的表达。结果：（1）模型组尿蛋白量逐渐增加，而治疗组第6周和第8周的尿蛋白量均低于同时期的非治疗组水平（P=0．02和P＜0．01）；（2）模型组nephrin mRNA表达量在2、4、6、8周分别为对照组的0．5、1．0、2．0、1．6倍，并与尿蛋白量呈正相关（r=0．699，P＜0．001）；（3）模型治疗组nephrin mRNA的表达第8周达非治疗组的1．3倍。结论：（1）随着阿霉素肾病大鼠尿蛋白排泄量的增加，肾皮质nephrin mRNA的表达发生了显著变化，并与蛋白尿的发生发展之间具有一定的相关性；（2）来氟米特可减少肾病大鼠尿蛋白量，同时增加肾皮质nephrin mRNA的表达。     

肝硬变门静脉高压症大鼠肝组织内皮素—1基因的mRNA表达研究

目的：研究肝硬变大鼠肝组织内皮素－1（ET－1）的基因mRNA表达的变化。方法：半定量逆转录多聚酶链反应（SqRT-PCR)。结果：经SqRT-PCR测定大鼠肝组织ET－1基因的mRNA（integral optical density,IOD)值：各期肝硬变大鼠模型制作2周、4周、6周、8周分别为68330±1096、73836±1125、85712±1283、89215±1366，均明显高于正常对照鼠37745±1066（P＜0．01），但肝硬变大鼠各组之间的差异无统计学意义（P＞0．05）。结论：肝硬变门静脉高压症时大鼠肝组织内ET－1基因的mRNA表达明显增加。     

背根神经节Nav1.8磷酸化在大鼠糖尿病痛性周围神经病变中的作用

目的 本研究采用射频热凝毁损腰交感神经节,探讨背根神经节（DRG）Nav1．8磷酸化在大鼠糖尿病痛性周围神经病变中的作用。方法 采用腹腔注射链尿佐菌素诱导糖尿病痛性周围神经病变大鼠模型,取造模成功的大鼠20只,随机分为糖尿病对照组（D组）及交感神经节射频热凝组（R组）,每组10只,另取10只同月龄大鼠为正常对照组（C组）。R组大鼠在X光机介导下行右侧L3,4椎旁腰交感神经节射频热凝毁损。分别于射频热凝前、射频热凝后1、2周时,采用von Frey纤维丝测定大鼠右侧后爪对机械性刺激缩足反应的阈值（PWT）;射频热凝后2周,采用Western-blotting方法测定DRG细胞Nav1．8蛋白和苏氨酸磷酸化Nav1．8蛋白表达,并采用透射电镜观察大鼠腓肠神经超微病理结构。结果 与C组比较,射频热凝前D组和R组PWT降低（P＜0．01）。射频热凝后1～2周,R组较D组PWT升高,但仍较C组降低（P＜0．05）。C组髓鞘排列均匀,轴突内可见形态正常的线粒体;D组脱髓鞘明显,髓鞘板层排列紊乱、断裂、肿胀;R组脱髓鞘程度明显减轻,髓鞘板层局部排列紊乱、空泡形成。与C组比较,D组和R组Nav1．8蛋白表达降低（P＜0．05）,而苏氨酸磷酸化Nav1．8蛋白表达增高（P＜0．01）;R组苏氨酸磷酸化Nav1．8蛋白表达低于D组（P＜0．05）。结论 DRG细胞Nav1．8的磷酸化可能是糖尿病痛性周围神经病变大鼠痛觉过敏形成的机制之一。     

十二指肠空肠旁路术和袖状胃切除术对糖尿病大鼠肝脏葡萄糖激酶表达的影响

目的探讨十二指肠空肠旁路手术（DJB）和袖状胃切除术（SG）对糖尿病大鼠肝脏葡萄激酶（GCK）表达的影响。方法制作GK大鼠（非肥胖糖尿病大鼠）和正常SD大鼠DJB和SG两种术式的动物模型．动态观察术后空腹血糖和胰岛素的变化。术后8周取肝组织标本,分别采用实时定量RT—PCR和Western blot检测术后肝脏GCK mRNA和蛋白表达水平。结果GK大鼠DJB组和SG组术后各时间点空腹血糖均显著低于术前水平（均P〈0．01）,假手术组1周内空腹血糖降低,2周后逐渐恢复到术前高水平：SD大鼠各种手术后血糖水平无明显改变（均P〉0．05）。GK大鼠DJB术后肝脏GCK mRNA和蛋白表达水平分别为1．45±0．29和494．25±30．25,SG术后分别为0．65±0．25和345．25±28．13;假手术组术后GCK mRNA和蛋白表达水平分别为1．05±0．19和409．13±26．86,与DJB组和SG组比较,差异有统计学意义（均P〈0．01）;对照组GCK mRNA和蛋白表达水平分别为1．04±0．17和404．75±30．90,与DJB组和SG组比较,差异具有统计学意义（均P〈0．01）。SD大鼠术后GCK表达也呈现了相似的变化。结论DJB和SG均能明显改善糖尿病大鼠的术后血糖水平．但两种术式对肝脏GCK的表达却具有完全不同的影响。     

补肾方对流产大鼠胎盘胰岛素样生长因子介导孕激素生成的影响

目的探讨补肾方对流产大鼠胎盘胰岛素样生长因子Ⅰ、Ⅱ（IGF—Ⅰ、IGF-Ⅱ）及其受体（R）在胎盘滋养层细胞表达的影响及其与孕激素分泌的关系。方法溴隐亭皮内注射法建立流产大鼠模型,于孕1～8、1～11d灌服补肾方药,孕酮（P）肌注作为阳性对照组,采用放射免疫法测定大鼠血清P水平;逆转录聚合酶链反应（RT-PCR）技术检测IGF-Ⅰ、IGF-Ⅱ及其受体在不同组大鼠胎盘中的mRNA表达。结果溴隐亭模型组IGF-Ⅰ、IGF-Ⅱ、IGF-Ⅱ RmRNA表达比正常对照组显著降低（P〈0．01）;中药组及P组降低IGF-ⅠRmRNA表达,并不同程度提高模型大鼠胎盘IGF-Ⅰ、IGF-Ⅱ、IGF-ⅡR mRNA表达。表达强度随孕龄和给药时间逐渐升高,且与血清P有相关。结论补肾方益气清热、固肾安胎,可调控胎盘滋养细胞IGF-Ⅰ、IGF-Ⅱ及其受体的基因表达,并且调节滋养层细胞的增殖活性,促进P合成分泌增加,从而达到保胎的目的。     

雌激素受体β蛋白及其同分异构体在慢传输型便秘大鼠结肠中的表达

目的研究雌激素受体β（ERβ）蛋白及其同分异构体mRNA在慢传输型便秘（STC）大鼠结肠的表达。方法建立STC大鼠模型．采用RT-PCR及Western blot技术检测20只STC大鼠及20只对照组结肠ERβ蛋白及其同分异构mRNA的表达。结果rERβ2mRNA在STC大鼠及对照组结肠均有表达,redβ1、rERβ1δ3、rERβ1δ3,及rERβ1δ4mRNA在两组中均无表达．STC组rERβ2mRNA及蛋白表达量（0．31±0．03,0．57±0．15）低于对照组（0．55±0．05,0．99±0．15）,差异有统计学意义（P〈0．01）。结论STC大鼠结肠ERβ蛋白及ERβ2mRNA表达量均低于对照组,提示ERβ参与STC的发病。     

烫伤延迟复苏大鼠组织白细胞介素18mRNA表达的变化

目的 探讨烫伤延迟复苏后不同组织白细胞介素18（IL－18）mRNA的动态表达规律。方法 采用大鼠TBSAⅢ度烫伤延迟复苏模型,54只大鼠随机分为正常对照组、烫伤延迟复苏组、选择性消化道脱污染（SDD）预防组,分别在伤前及伤后2、8、16、24h,采用逆转录聚合酶链式反应,检测肠、肺、肝、肾等组织IL－18 mRNA含量。结果 烫伤延迟复苏后体循环内毒素水平显升高,8、24h达高峰（P＜0．01）,给予SDD预防治疗可显降低内毒素峰值（P＜0．05）;另一方面,烫伤后2h,肺、肝、肾等组织IL－18 mRNA含量表达较伤前值有显升高,烫伤后8h达高峰（P＜0．01）,且一直持续至伤后24h,给予SDD预防后可不同程度抑制IL－18 mRNA的表达（P＜0．05－0．01）。相关分析显示,体循环内毒素水平同肠、肺、肝组织IL－18 mRNA呈显正相关（r值分别为0．298、0．290、0．365,P＜0．05－0．01）。结论 肠、肺、肝、肾等组织IL－18 mRNA表达在烫伤早期即显增多,并呈逐渐升高的趋势,创伤后内毒素血症对机体多种组织IL－18 mRNA基因表达具有重要影响。     

17β-雌二醇对大鼠肝纤维化门静脉压力的作用

目的观察17β-雌二醇（E2）对四氯化碳（GEl4）诱导大鼠肝纤维化中门静脉压力变化的作用。方法40只Wistar雄性大鼠随机分为A、B、C和D共4组，均采用CCl4诱导肝纤维化12周。另外，A组同时采用肌注E2（2mg／kg体重），2次／周；B组采用肌注E2（1mg／kg体重），2次／周；C组作为对照组；D组采用每日口服他莫昔芬6mg／kg体重。第13周将全部大鼠麻醉后测定门静脉压力（PVP）、并采用实时荧光定量（Real—Time）聚合酶链反应（PCR）技术测量大鼠肝脏组织中核转录因子p65（NF-kappaBIN55）mRNA和转化生长因子-β1（TGF-β1）mRNA的表达，采用Massion染色检测大鼠肝组织中胶原纤维（CF）含量情况，并将不同组别大鼠肝组织中NF-kappaBIN55mRNA值、TGF-β1mRNA值、CF含量以及PVP作相关性分析。结果（1）各组大鼠PVP高低为：A〈B〈C〈D，各组比较差异有统计学意义（F=54．712，P〈0．05）；（2）各组大鼠肝组织中NF-kappa Bp65 mRNA的表达情况为：A〈B〈C〈D，各组比较差异有统计学意义（F=109．024，P〈0．05）；（3）各组大鼠肝组织中TGF．1mRNA表达高低比较：A〈B〈C〈D，组间比较差异有统计学意义（F=224．969，P〈0．01）；（4）各组大鼠肝组织CF含量比较：A〈B〈C〈D，组间比较差异有统计学意义（F=6．929，P〈0．01）；（5）各组大鼠肝组织中NF-kappa Bp65 mRNA值和TGF-1mRNA值呈直线相关（r=0．724，P〈0．05），TGF-β1 mRNA值和cF含量呈直线相关（r=-0．871，P〈0．05），CF含量和PVP也呈直线相关（r=0．902，P〈0．05）。结论E2通过抑制大鼠肝纤维化肝组织中NF-kappa Bp65 mRNA的表达，减弱了TGF-β1 mRNA的表达，使得肝组织中CF含量减少，以致PVP降低。     

FGFR3在大鼠肝硬化模型中的动态表达研究

目的：观察大鼠肝硬化形成过程中成纤维细胞生长因子受体3（Fibroblast growth factor receptor3,FGFR3）的表达变化。方法：70只雄性SD大鼠,随机取10只作为对照组,其余60只作为肝硬化组。采用剂量频次渐变式四氯化碳（CCL）腹腔内注射建立肝硬化大鼠模型。检测2组大鼠的血清ALT、体重、肝体比,病理组织行包括HE和嗜银染色．并采用荧光定量聚合酶链反应（real—timePCR）和蛋白质印迹（Western blot）检测FGFR3基因和相应蛋白在肝硬化形成过程中的表达变化。结果：肝硬化组大鼠的血清ALT、肝体比和死亡率均显著高于对照组（P均〈0．01）;而体重则显著低于对照组（P〈0．01）;肝硬化组大鼠肝组织大体观察、HE染色及嗜银染色均呈明显肝硬化表现,而对照组则无该表现：real-timePCR及Western-blot结果显示,FGFR3在肝硬化形成过程中总体表达逐渐增强。结论：剂量频次渐变式GEl4腹腔内注射法是一种高效、低成本的大鼠肝硬化建模方法。而肝组织FGFR3在肝硬化发生、发展过程中的动态表达在一定程度上反映了肝纤维化及肝硬化程度。     

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.