绞股蓝总皂苷防治单侧输尿管结扎大鼠肾间质纤维化的实验研究

目的探讨绞股蓝总皂苷(GPs)对单侧输尿管结扎(UUO)大鼠肾组织结缔组织生长因子(CTGF)表达及肾间质纤维化的影响。方法采用UUO大鼠模型,将大鼠随机分为3组假手术组、模型组、GPs组。假手术组和模型组仅给予标准饲料30g,GPs组于术前3d至术后9d每天给予GPs200mg·kg-1·d-1灌胃,第9d处死各组大鼠。免疫组化法检测各组肾组织CTGF、转换生长因子β1(TGF-β1)和α-平滑肌肌动蛋白(α-SMA)的表达;RT-PCR方法检测各组CTGFmRNA含量;Masson染色评定各组肾小管间质损害程度。结果模型组CTGF、TGF-β1、α-SMA的表达及肾小管间质损伤指数明显高于假手术组(P<0.01),而GPs组各项指标明显低于模型组(P<0.01)。各项指标作相关分析,CTGF与肾小管间质损伤指数(r=0.788,P<0.01)、TGF-β1(r=0.879,P<0.01)、α-SMA(r=0.940,P<0.01)为正相关关系。结论绞股蓝总皂苷可以抑制肾纤维化时结缔组织生长因子表达,从而遏制肾纤维化的进展。     

结缔组织生长因子在关木通相关肾小管间质肾病肾间质纤维化中的作用

目的 通过观察关木通相关肾小管间质肾病(GMT-TIN)肾小管间质内纤维化相关生长因子表达及细胞外基质(ECM)沉积的特点,探讨其纤维化病变发生与发展的有关环节。方法 22例GMT-TIN患者根据病理特点分为急性组8例、慢性轻型组8例和慢性重型组6例,对其纤维化程度进行半定量分析。应用免疫组化SP法观察肾活检组织标本中,肾小管间质内α-平滑肌肌动蛋白(α-SMA)、纤连蛋白(FN)、IV型胶原、结缔组织生长因子(CTGF)和转化生长因子 β1(TGF-β1)的表达情况。分析上述指标之间以及与纤维化病变之间的相关关系。结果 (1)各组肾小管间质内均检测到高表达的α-SMA、FN和IV型胶原,随病变慢性化加重3者表达均明显增强,并与肾间质纤维化程度正相关(P<0.01)。(2)各组肾间质内均出现CTGF及TGF-β1表达,2者间显著正相关(r=O.771,P<0.0001),但在时相上存在一定差异。(3)肾间质内CTGF表达分别与FN及IV型胶原沉积正相关(r=0.6855和0.5964,P<0.01)、与纤维化病变程度正相关(r=0.4941,P<0.05)。结论(1)GMT-TIN肾间质内CTGF的高表达、CTGF与ECM沉积以及纤维化病变的相关性,提示其在GMT-TIN肾间质纤维化病变中起重要作用。(2)CTGF与TGF-β1的相关关系及2者表达时相的差异,进一步支持CTGF可能作为TGF-β1的下游效应因子在纤维化病变     

维甲酸抑制大鼠单侧输尿管梗阻模型肾间质纤维化

目的探讨维甲酸对大鼠单侧输尿管梗阻(UUO)模型肾间质纤维化的影响。方法建立大鼠UUO模型前2d治疗组和对照组分别每天给予10mg/kg全反式维甲酸或溶媒皮下注射。观察模型第3、7和12天肾小管损害百分比、肾间质纤维化程度、肾间质巨噬细胞数、肾间质α-平滑肌肌动蛋白(α-SMA)、胶原Ⅲ和单核细胞趋化蛋白-1(MCP-1)mRNA的表达。结果维甲酸显著减轻肾小管损害和肾间质纤维化(P<0.01)。治疗组肾间质巨噬细胞数和肾间质α-SMA表达显著低于对照组(P<0.01)。维甲酸显著抑制胶原Ⅲ和MCP-1mRNA表达(P<0.01)。结论维甲酸减少大鼠UUO模型肾间质巨噬细胞浸润、降低胶原Ⅲ和MCP-1mRNA表达、抑制α-SMA蛋白的表达,从而减轻肾间质纤维化。     

积雪草颗粒对UUO大鼠肾组织CTGF、α-SMA、HGF、MCP-1表达的影响

目的:探讨积雪草对单侧输尿管梗阻(UUO)大鼠肾组织结缔组织生长因子(CTGF)、α-肌动蛋白(α-SMA)、肝细胞生长因子(HGF)、单核细胞趋化蛋白(MCP-1)-1表达的影响,为临床上应用积雪草延缓肾衰竭提供依据。方法:50只雄性SD大鼠随机分为假手术组、模型组、积雪草大剂量组、积雪草小剂量组、对照(福辛普利)组。每组10只,除假手术组外均成功建立UUO大鼠模型,术后21 d腹主动脉采血,检测肝、肾功能的变化;免疫组化检测CTGF、α-SMA、HGF、MCP-1的表达部位及含量。结果:模型组CTGF、α-SMA、MCP-1的表达高于假手术组(P<0.01),药物干预组指标低于模型组(P<0.01);药物干预组HGF含量显著高于模型组(P<0.01);其中积雪草大剂量组的表达高于小剂量组(P<0.01),但与福辛普利组相似(P>0.05)。药物干预组BUN水平下降,Scr、ALT、AST变化不明显。结论:积雪草可通过上调UUO大鼠肾组织HGF的表达,抑制UUO大鼠肾组织CTGF、α-SMA、MCP-1表达而实现其抗肾小管间质纤维化(TIF)的作用,大剂量组与福辛普利组作用相似,且没有明显的肝肾毒性。     

结缔组织生长因子在肾活检组织中的表达及意义

目的 :检测不同间质纤维化程度的肾活检组织中结缔组织生长因子 (CTGF)和α -平滑肌肌动蛋白(α -SMA)的表达 ,观察CTGF、α -SMA与肾间质纤维化程度和肾功能之间的关系 ,探讨CTGF在肾脏肌成纤维细胞形成中可能的作用。方法 :选取不同病因和类型的肾活检标本 4 5例 ,按常规进行染色 ,根据光镜下小管间质的病变分组。采用免疫组化方法 ,检测各组标本CTGF和α -SMA的表达 ,并将CTGF的表达、α -SMA的表达、间质纤维化程度和患者血肌酐水平进行比较。结果 :CTGF主要表达于肾小管上皮细胞和一些肾间质细胞胞浆 ,并且随间质病变的加重 ,表达量增加 ,范围增大 ;α-SMA在病变肾间质区域表达增强 ,一些管腔破坏和萎缩的肾小管上皮细胞也可见表达 ,阳性分布区域与CTGF相似。肾小管间质中CTGF、α -SMA表达量之间呈正相关 ,CTGF和α -SMA表达量与肾间质纤维化病变程度和患者血肌酐水平均呈正相关关系。结论 :CTGF可能通过促进间质中肌成纤维细胞的形成而参与肾间质纤维化的形成 ,CTGF的表达上调对肾脏疾病有预后价值     

黄芪注射液改善肾间质纤维化的作用机制研究

目的:观察黄芪注射液对肾间质纤维化的改善作用并探讨其机制.方法:以单侧输尿管梗阻(unilateral ureteral obstruction,UUO)大鼠模型为研究对象.将36只SD大鼠随机分为对照组、UUO模型组和黄芪注射液治疗组.治疗组每日给予黄芪注射液(5 ml·kg-1·d-1)腹腔注射,术前1天始至术后第9天止.术后第10天取术侧肾脏组织.HE、PAS和苦味酸-天狼星红染色,观察肾小管间质病理改变、肾皮质相对间质容积和相对胶原含量的变化.免疫组织化学方法检测转化生长因子-β1(TGF-β1)、α-平滑肌肌动蛋白(α-SMA)和Ⅰ型胶原在肾间质中的表达.免疫印迹方法检测热休克蛋白47(heat shock protein 47,HSP47)在肾脏中的表达.结果:UUO大鼠模型组和治疗组均出现明显的肾间质纤维化病理改变,但治疗组病变程度相对较轻.肾皮质相对间质容积和相对胶原含量于模型组及治疗组明显高于对照组(P＜0.01),但治疗组明显低于模型组(P＜0.01).免疫组化染色显示:TGF-β1、α-SMA和Ⅰ型胶原表达于模型组和治疗组均明显高于对照组(P＜0.05),但治疗组较模型组有明显减少(P＜0.05).免疫印迹方法显示:HSP47蛋白表达于模型组和治疗组明显高于对照组(P＜0.05),但治疗组较模型组有明显减少(P＜0.05).结论:黄芪注射液对大鼠肾间质纤维化具有明显的改善作用,这种作用部分是通过抑制TGF-β1表达,阻止肾小管上皮细胞转分化,减少胶原合成实现的.     

慢性马兜铃酸肾病患者肾小管上皮细胞转分化的研究

目的探讨慢性马兜铃酸肾病。肾小管上皮细胞转分化与肾间质纤维化的关系。方法以慢性马兜铃酸肾病患者的肾组织为标本,作常规Masson染色化病理检查;用天狼星红组织化学(组化)染色检查胶原Ⅰ、Ⅲ表达;用免疫组化染色检查角蛋白(CK)、α-平滑肌肌动蛋白(α-SMA)、波形蛋白(Vim)及转化生长因子-β1(TGF-β1)表达。对结果进行定量或半定量分析。结果 肾间质Masson染色纤维化面积及胶原Ⅰ、Ⅲ面积,与肾小管间质α-SMA及Vim阳性表达面积呈显著正相关(P<0.05),与肾小管CK阳性表达面积呈显著负相关(P<0.05);病变过程中健存肾小管TGF-β1表达明显增强。结论慢性马兜铃酸肾病患者的肾小管上皮细胞可转分化为肌成纤维细胞,参与肾间质纤维化,而这细胞转分化很可能与其自身高表达TGF-β1相关。     

金属蛋白酶组织抑制剂1在大鼠肾小管间质损害中的表达及其意义

目的 观察单侧输尿管梗阻(UUO)大鼠模型中金属蛋白酶组织抑制剂1(TIMP-1)在肾小管间质中的表达部位、动态变化及其与肾小管问质损害的关系。方法 制备UUO大鼠模型,采用免疫组织化学方法检测UUO术后第1、3、5、7、14天肾小管间质中TIMP-1、α-平滑肌肌动蛋白(SMA)、增殖细胞核抗原(PCNA)和单核巨噬细胞抗原(ED)-1的表达及其与输尿管梗阻后肾小管间质损害的关系。结果 UUO术后第1天肾间质可见少量TIMP-1表达细胞,第3～7天TIMP-1表达明显增加,主要表达于肾小管上皮细胞和肾间质。UUO术后第3天肾小管PCNA表达达高峰,随后下降,而肾间质PCNA水平于第7～14天仍较高。UUO术后第3天肾间质成纤维细胞及肾小管上皮细胞可检出α-SMA表达并随时间递增。α-SMA阳性面积与肾间质相对面积成正相关(r=0.924,p<0.01)。TIMP-1表达与间质相对面积(r=0.835,P<0.05)及α-SMA阳性面积(r=0.922,P<0.01)成正相关。结论 TIMP-1蛋白质于肾小管间质病变早期表达于肾小管间质,早于肾间质纤维化出现,其表达量与肾间质α-SMA表达及肾间质相对面积呈正相关并随病变进展逐渐增加。TIMP-1在肾小管上皮细胞和问质细胞的高表达及肾小管上皮细胞和间质细胞增殖可能参与介导UUO术后肾小管间质损害。     

冬虫夏草在肾间质纤维化大鼠模型中的作用及其对TGF-β1、α-SMA的影响

目的：探讨冬虫夏草在肾小管间质纤维化大鼠模型中肾脏保护作用及其可能的作用机制。方法：采用单侧输尿管结扎术（UUO）致肾小管间质纤维化大鼠模型。将大鼠随机分为3组：假手术组、模型组、虫草治疗组。手术后第9d处死各组大鼠，用免疫组化半定量检测各组肾脏TGF-β1、α-SMA、Ⅳ型胶原的表达，Masson染色评定各组肾小管间质损害程度。结果：模型组TGF-β1、α-SMA、Ⅳ型胶原的表达及肾小管间质损伤指数明显高于假手术组（P〈0．01），而虫草治疗组明显低于模型组（P〈0．01）。结论：冬虫夏草可能通过下调TGF-β1，抑制肾小管上皮细胞、成纤维细胞转化为成肌纤维细胞防治。肾小管间质纤维化。     

毛蕊花糖苷改善单侧输尿管梗阻模型大鼠肾纤维化

该研究探讨毛蕊花糖苷对单侧输尿管梗阻模型大鼠肾纤维化的作用。采用随机数字表法将24只成年健康雄性SD大鼠随机分为假手术(CON)组、单侧输尿管梗阻(UUO)组、UUO+毛蕊花糖苷(ACT)组和UUO+贝那普利(BZ)组, 采用单侧输尿管结扎术建立肾纤维化动物模型。HE染色和Masson染色观察各组大鼠肾组织病理改变。免疫组化法检测肾组织Ⅲ型胶原蛋白(CollagenⅢ)、热休克蛋白(HSP)-47、结缔组织生长因子(CTGF)、α平滑肌肌动蛋白(α-SMA)、β联蛋白(β-catenin)、B细胞淋巴瘤因子2(Bcl-2)和半胱氨酸蛋白酶3(Caspase-3)蛋白的表达。Western印迹法检测肾组织葡萄糖调节蛋白(GRP)78蛋白表达。结果显示, 与CON组比较, UUO组大鼠肾小管扩张, 肾间质胶原纤维沉积显著增加;UUO+ACT组和UUO+BZ组大鼠肾小管扩张和间质胶原纤维沉积程度较UUO组显著减轻, 但仍明显重于CON组。与CON组比较, UUO组大鼠肾组织CTGF、α-SMA、CollagenⅢ、HSP-47、β-catenin及GRP78蛋白表达量均显著较高, Bcl-2...     

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.