不同剂量氯胺酮复合丙泊酚诱导在全麻剖宫产中的应用

目的 观察不同剂量氯胺酮复合丙泊酚诱导对产妇血流动力学及新生儿Apgar伴分的影响.方法 择期剖宫产足月初产妇60例,ASA Ⅰ或Ⅱ级,随机均分为0.5 mg/kg氯胺酮复合丙泊酚2 mg/kg组(A组)和1.0mg/kg氯胺酮复合丙泊酚2mg/kg组(B组).观察围术期产妇心率、血压变化及不良反应,新生儿1 min和5min的Apgar评分,以及新生儿行为神经评分(NBNA).结果 与诱导前比较,两组产妇插管后1 min的SBP、DBP明显升高,HR增快(P＜0.01),且A组的SBP和HR明显高于和快于B组(P＜0.05).两产妇组均无术中知晓.两组新生儿Apgar评分及NBNA评分差异无统计学意义.结论 2mg/kg丙泊酚复合1.0 mg/kg氯胺酮诱导产妇心率、血压变化较小,同时不增加新生儿呼吸抑制风险.     

预注小剂量高渗氯化钠羟乙基淀粉40对剖宫产手术母婴的影响

目的 观察术前预充小剂量高渗氯化钠羟乙基淀粉40(HSH)对剖宫产产妇血流动力学及母婴血气、离子、丙二醛(MDA)和血浆超氧化物歧化酶(SOD)的影响.方法 200例择期行剖官术产妇,随机双盲均分为:HSH组(H组)和复方乳酸钠组(L组).监测并记录入室时(T0)、预充量输注完即刻(T1)、腰麻注药后5 min(T2)、胎儿娩出时(T3)、术毕(T4)的HR、BP、SpO2;同时采脐动、静脉血和产妇动脉血各5 ml测定血乳酸(Lac)、血细胞比容(Hct)、Na+、K+、血气及SOD活力和MDA浓度;记录新生儿生后1和5 min的Apgar评分并计算胎儿氧摄取率(ERO2).结果 与T0时比较,T2～T4时L组产妇SBP、DBP明显下降,HR明显增快(P<0.05).与H组比较,T2～T4时L组产妇SBP、DBP明显降低,HR明显增快(P<0.05);H组产妇动脉血PO2明显高于L组(P<0.05),Hct和Lac明显低于L组(P<0.05);H组新生儿脐动、静脉的PO2明显高于L组(P<0.05);与入室前比较,胎儿娩出时两组产妇动脉血SOD值明显降低(P<0.05);胎儿娩出时H组产妇动脉血、新生儿脐动脉血及脐静脉血SOD值均高于L组(P<0.05);H组新生儿脐动脉血及脐静脉MDA值低于L组(P<0.05).H组胎儿ERO2较L组明显升高(P<0.05).结论 剖宫产围术期,应用小剂量HSH扩容,能稳定母婴的血流动力学,更好地维持母婴内环境稳定,提高产妇和胎儿的安全性.     

高渗氯化钠羟乙基淀粉40注射液防治产妇仰卧位低血压综合征

目的观察预输注高渗氯化钠羟乙基淀粉40注射液(HSS 40)对产妇仰卧位低血压综合征的防治效果。方法行剖宫产产妇180例,随机均分为三组:W组输注6%羟乙基淀粉130/0.4氯化钠注射液250 ml;H组输注HSS 40 250 ml;N组输注生理盐水250 ml。均于硬膜外麻醉穿刺成功后30 min内输完。于输液前、输液后30 min、术后1 d采集产妇静脉血及脐动脉血检测电解质,记录术中及术后24 h尿量。观察仰卧位低血压综合征的发生情况并记录新生儿1 min Apgar评分。结果仰卧位低血压发生率W组(8.3%)和H组(6.7%)显著低于N组(18.3%)。H组术后24 h尿量显著多于W组和N组(P<0.05)。结论 HSS 40预输注可有效防治产妇仰卧位低血压综合征发生,对胎儿无不良影响。     

可乐定-氯胺酮硬膜外给药在剖宫产术的应用

目的观察剖宫产术中硬膜外并用氯胺酮和可乐定对产妇和新生儿的影响。方法80例择期剖宫产产妇,随机分为四组氯胺酮组(LK组);可乐定组(LC组);氯胺酮 可乐定组(LKC组);对照组(L组)。麻醉生效后,硬膜外腔给予氯胺酮0·6mg/kg和/或可乐定1μg/kg。术中常规监测SBP、DBP、ECG、HR和SpO2。每组于用药前(T0)、切皮时(T1)、胎儿娩出时(T2)及术毕(T3)对产妇进行疼痛视觉模拟评分(VAS)和镇静评分,并取产妇静脉血2ml、脐动静脉血各2ml,测定血浆肾上腺素(E)、去甲肾上腺素(NE)、皮质醇(Cor)浓度。记录术中不良反应。胎儿娩出后1min和5min行Apgar评分。结果四组产妇SBP、DBP和SpO2在各时点差异均无显著意义;与L组相比,LC组与LKC组HR明显下降(P<0·05)。在T1、T2、T3时LK、LC和LKC组VAS均较L组明显降低(P<0·05),LKC组降低尤为明显(P<0·01);镇静评分均明显升高,LKC组升高更为明显(P<0·01)。在T1时L组和LK组产妇E、NE、Cor浓度较T0时均有明显升高(P<0·05),但在LC和LKC组升高不明显;在T2时各组E、NE、Cor浓度较T0时均有明显升高(P<0·05),但LKC组较其他组升高较少;在T3时L组E、NE、Cor浓度较T0时仍有明显升高(P<0·05),但LK组、LC和LKC组均有不同程度下降(P<0·05),LKC组下降尤其明显(P<0·01)。在脐动、静脉血,LK组、LC和LKC组E、NE、Cor浓度较L组均有降低(P<0·05),其中LKC组降低尤其明显(P<0·01)。四组新生儿出生后1min及5minApgar评分差异均无显著意义。L组有5例出现寒战,LK组有4例产妇出现兴奋多语。结论氯胺酮可乐定联合硬膜外给药,能更好地消除产妇术中疼痛,降低母婴的应激反应,减少二者单独应用时对母婴的不良影响。     

腰麻-硬膜外联合麻醉对剖宫产母婴肾素-血管紧张素-醛固酮系统的影响

目的 研究腰麻－硬膜外联合麻醉（CSEA）对剖宫产母婴肾素－血管紧张素－醋固酮系统（RAAS）的影响。方法 将60例ASA Ⅰ级行择期剖宫产的健康产妇随机分为硬膜外麻醉组（EA组，n＝30）和CSEA组（n＝30)。分别于注射局麻药前(T0)、切皮后即刻（T1）、胎儿晚出后即刻（T2）、术毕即刻（T3）和术后24h（T4）取母体静脉血和胎儿娩出后胎儿脐动、静脉血测定血清素活性（PRA）、血管紧张素Ⅱ（AT-Ⅱ）和醛固酮（ALD）浓度；评定麻醉效果，记录痛觉阻滞平面达T7水平的时间，注射局麻药至胎儿娩出时间（I－DI）及新生儿娩出1min、5min的Apgar评分。结果 两组术中SP、DP、HR、SpO2的变化及新生儿娩出1min、5min的Apgar评分。结果 两组术中SP、DP、HR、SpO2的变化及新生儿娩出1min、5min的Apgar评分差异无显著性（P＞0.05）。同EA组相比，CSEA组麻醉起效时间明显缩短（P＜0.01）。两组母体于T1、T2、T4的PRA、AT－Ⅱ、ALD值均比T0、T3值明显降低（P＜0.01），胎儿脐动、静脉血中三者值差异不明显，但明显低于母体T0、T3值（P＜0.01）。结论 CSEA用于剖宫产手术时，只要运用得当，不会对母婴AAS产生不良影响。     

预注去氧肾上腺素或麻黄碱对腰麻下剖宫产产妇及新生儿的影响

目的比较预注去氧肾上腺素与麻黄碱对腰麻下剖宫产术产妇及新生儿的影响。方法选择择期单次腰麻下剖宫产产妇60例,随机分为两组:去氧肾上腺素组(P组)和麻黄碱组(E组),每组30例。产妇腰麻改平卧位后即刻静脉推注去氧肾上腺素60μg或麻黄碱5mg,若产妇血压下降超过20%时使用去氧肾上腺素或麻黄碱升压。记录入室时(T0)及腰麻后1min(T1)、3min(T2)、5min(T3)、10min(T4)、胎儿娩出时(T5)的HR、SBP和DBP;记录产妇不良反应及新生儿1、5min的Apgar评分,同时检测胎儿娩出时脐静脉血气。结果 T1~T5时E组HR均明显快于P组和T0时(P0.05或P0.01)。E组和P组的低血压及高血压发生率差异无统计学意义。两组新生胎儿脐静脉血乳酸水平、血气分析及Apgar评分差异无统计学意义。E组恶心呕吐发生率明显高于P组(P0.05)。结论腰麻剖宫产术预注去氧肾上腺素能较好地防治产妇术中低血压,产妇恶心呕吐发生率较低,对新生儿无不良影响。     

硬膜外分娩镇痛对新生儿氧合状态的影响

目的评价硬膜外分娩镇痛对新生儿氧合状态的影响。方法选择初产妇60例,年龄22～33岁,ASAⅠ或Ⅱ级,足月单胎头位妊娠,将自愿接受硬膜外分娩镇痛的产妇分至E组,自愿放弃分娩镇痛的产妇分至S组,每组30例。E组:宫口开至3cm时,于L_(2-3)椎间隙行硬膜外穿刺,注入试验剂量1%利多卡因3ml,观察3～5min,注入0.1%罗哌卡因与0.25μg/ml舒芬太尼的混合液8～12ml作为首剂量,获得满意镇痛效果后接PCA泵,背景输注速率8～12ml/h,PCA量3～5ml,锁定时间30min,最大量20ml/h,胎儿胎盘娩出,缝合伤口全部结束后停药拔管。S组:按常规自然分娩程序处理。记录产妇宫口开3、6、8、10cm时VAS疼痛评分;记录新生儿出生后1、5min时Apgar评分;记录脐动脉血气分析及血清乳酸浓度;采用ELISA法测定脐动脉血中脐血中缺血修饰白蛋白(ischemia modified albumin,IMA)、白蛋白浓度。结果产妇宫口开6、8、10cm时E组VAS评分明显低于S组(P0.05)。两组新生儿Apgar评分、脐动脉血气分析、血清乳酸浓度和脐动脉血IMA浓度、白蛋白浓度以及IMA/白蛋白比值差异无统计学意义。结论硬膜外分娩镇痛对脐血IMA浓度以及新生儿氧合无影响,且镇痛效果确切,是一种安全有效的分娩镇痛方法。     

小剂量氯胺酮用于剖宫产麻醉对脐血气及新生儿Apgar评分的影响

小剂量氯胺酮用于产科麻醉是否对新生儿产生抑制,至今仍有争议。为验证这一问题,我们在1990年12月至1991年4月对46例剖宫产的产妇进行了脐动、静脉血气分析及新生儿Apgar评分,随机分成氯胺酮组和局麻组,局麻组用0.5％普鲁卡因50～100ml逐层     

目标导向液体治疗对剖宫产术产妇蛛网膜下腔阻滞后低血压的影响

目的 评价经胸壁超声(TTE)指导的目标导向液体治疗(GDFT)对降低剖宫产术产妇蛛网膜下腔阻滞后低血压发生率的影响。方法 选择于蛛网膜下腔阻滞下行择期剖宫产术产妇128例,年龄18～35岁,BMI≤30 kg/m²,ASAⅡ级。将产妇随机分为两组：对照组(C组)和GDFT组(T组),每组64例。C组在胎儿娩出前输注复方乳酸钠20 ml·kg^-1·h^-1,胎儿娩出后减至5 ml·kg^-1·h^-1。T组产妇在蛛网膜下腔阻滞后3 min内输注复方乳酸钠3 ml/kg,在TTE指导下使每搏变异度(ΔSV)≤10%,行GDFT前后输注复方乳酸钠5 ml·kg^-1·h^-1。记录输液量、术中低血压的发生情况、去氧肾上腺素用量、术后24 h出血量和术后住院时间。记录麻醉前(t₀)、蛛网膜下腔阻滞注药完成后5 min(t₁)、胎儿娩出时(t₂)和蛛网膜下腔阻滞注药完成后15 min(t...     

腰-硬联合阻滞腰麻后硬膜外镇痛时机对分娩镇痛的影响

目的观察腰-硬联合阻滞(CSEA)腰麻后硬膜外镇痛时机对分娩镇痛的影响。方法选择ASAⅠ或Ⅱ级,足月初产妇80例,于宫口开至2~3cm时实施CSEA镇痛。将入选产妇采用随机数字表法均分为E1组、E2组、E3组和E4组,分别于蛛网膜下腔给药后3、30、60和90min接受持续硬膜外给药。L3~4椎间隙行硬膜外穿刺,取25G腰麻穿刺针刺入蛛网膜下腔,见脑脊液后给予布比卡因2.5mg和芬太尼25μg,然后均采用PCEA模式。0.1%罗哌卡因与2μg/ml芬太尼混合液100ml加入电子镇痛泵,设置背景维持量为10ml/h,单次剂量为5ml,锁定时间15min。记录第一产程时间、第二产程时间、催产素使用率、分娩方式和不良反应发生情况,新生儿Apgar评分、脐动脉血气分析,以及产妇补救剂量和硬膜外用药总量。结果四组产妇产程、催产素使用率、分娩方式、新生儿Apgar评分、脐动脉血气分析差异均无统计学意义。E1、E2组需要PCA例数和次数明显少于、硬膜外罗哌卡因补救剂量明显低于E3、E4组(P<0.05)。结论蛛网膜下腔给药后30min以内开始硬膜外持续镇痛可以明显减少PCA次数和硬膜外罗哌卡因的补救剂量。     

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.