联合应用胸腺肽α1治疗肾病综合征临床观察

目的：研究胸腺肽α1在预防肾病综合征并发感染及协助治疗的作用。方法：60例肾病综合征患者分为治疗组和对照组，治疗组予胸腺肽α1定期注射，两组治疗前后分别用流式细胞仪测定外周血T细胞亚群（CD3^＋，CD4^＋，CD8^＋，CD4^＋/CD8^＋）和NK细胞活性：同时观察两组病程和治疗效果。结果：治疗组患者的肾病综合征治疗有效率高于对照组（P〈0．05），尿蛋白转阴时间低于对照组（P〈0．05），治疗组感染率低于对照组，发生感染者抗菌素使用天数少于对照组（P〈0．05），组间感染类别差异无统计学意义（P〉0．05），治疗前两组CD3^＋，CD4^＋，CD8^＋，CD4^＋／CD8^＋和NK细胞活性差异无统计学意义，治疗后治疗组T细胞亚群活性和NK细胞活性明显高于治疗前（P〈0．05）。结论：胸腺肽α1改善肾病综合征患者免疫的失平衡，起到双向调节免疫的作用，减少治疗过程中并发症的发生，提高肾病综合征的治疗有效率。     

脓毒症患者外周血CD3+、CD4+、CD8+ T淋巴细胞的凋亡及Bcl-2蛋白表达

目的探讨脓毒症患者外周血淋巴细胞凋亡及其与Bcl-2蛋白表达的关系。方法采集44例脓毒症患者（脓毒症组，年龄19～86岁）和25例健康体检者（正常对照组，年龄29～80岁）的外周静脉血5ml，采用流式细胞仪分别检测CD3^＋、CD4^＋、CD8^＋T淋巴细胞凋亡率和Bcl-2蛋白表达。分析细胞凋亡率与Bcl-2蛋白表达的相关性。脓毒症诊断标准参考1991年美国胸科医师协会和美国危重病医学会联席会议制定的诊断标准。结果与正常对照组比较，脓毒症组患者CD3^＋、CD4^＋T淋巴细胞凋亡率升高，Bcl-2蛋白表达下降（P〈0．05），CD8^＋T淋巴细胞凋亡率及其Bcl-2蛋白表达差异均无统计学意义（P〉0．05），CD3^＋、CD4^＋T淋巴细胞凋亡率分别与其Bcl-2蛋白表达呈负相关（r=-0．389，P〈0．05；r=-0．689，P〈0．05）。结论脓毒症患者细胞免疫功能异常可能与Bcl-2蛋白表达下调导致淋巴细胞凋亡增加有关。     

慢性特发性荨麻疹患者外周血T及Th淋巴细胞亚群的表达

目的：探讨慢性特发性荨麻疹患者外周血T及辅助性T淋巴细胞（Th）亚群的表达及其在慢性特发性荨麻疹发病机制中的作用。方法：采用流式细胞术检测经四色荧光抗体染色的慢性特发性荨麻疹患者及正常对照外周血CD3^＋、CD4^＋、CD8^＋T淋巴细胞数及CD4^＋／IFN-γ’（Th1）、CD4^＋／IL-4^＋（Th2）细胞含量。结果：慢性特发性荨麻疹组外周血CD3^＋T淋巴细胞数无明显变化、CD4^＋T淋巴细胞数、CD8^＋T淋巴细胞数均降低;CD4^＋／CD8^＋比值增高,差异有统计学意义（P〈0．01）。慢性特发性荨麻疹患者外周血Th1细胞含量、Th1／Th2比值均明显低于正常对照组（P〈0．01,P〈0．05）,Th2细胞含量高于正常对照组（P〈0．01）。结论：慢性特发性荨麻疹患者外周血存在着T及Th淋巴细胞亚群分化失衡,这可能为慢性特发性荨麻疹发病的机制之一。     

重组人生长激素对大鼠肠道缺血再灌注后肠壁组织T淋巴细胞亚群和浆细胞凋亡的影响

目的探讨肠道屏障功能损害时应用重组人生长激素（rhGH）对肠道免疫屏障中肠黏膜及固有层内T淋巴细胞亚群和浆细胞凋亡的影响。方法将60只Wistar大鼠雌雄各半随机分为实验组和对照组，按实验天数又各分为3组，每组10只，以肠缺血再灌注模型造成肠道屏障功能损害的病理现象，实验组给予rhGH每日（1．33U／kg体重），采用免疫组织化学双染法观察回肠末端黏膜固有层内CD8^＋、CD4^＋、CD3^＋T淋巴细胞数及IgA浆细胞的凋亡数量变化。结果（1）对照组CD3^＋T淋巴细胞及IgA浆细胞的凋亡数量第6天明显高于第2、4天。差异有统计学意义（P〈0．01）。（2）实验组CD8^＋、CD4^＋T淋巴细胞的凋亡数量第6天明显低于第4天，差异有统计学意义（P〈0．01）。（3）实验组与对照组相比第2、4、6天IgA浆细胞的凋亡数量均明显减少。差异有统计学意义（P〈0．01）。实验组与对照组相比大鼠第2天CD8^＋、CD4^＋、CD3^＋T淋巴细胞的凋亡数量均减少，差异有统计学意义（P〈0．05，P〈0．01）。结论肠道屏障功能损害时应用重组人生长激素能够减少肠道免疫细胞的凋亡数量，对IgA浆细胞作用最明显。可能的作用时间在第6天。     

他克莫司对肝移植受者外周血T淋巴细胞亚群及共刺激分子表达的影响

目的 探讨他克莫司（FK506）对肝移植受者外周血T淋巴细胞亚群及其表面共刺激分子表达的影响。方法 采用荧光标记单克隆抗体和流式细胞技术，测定术后采用FK506治疗的肝移植受者（FK506治疗组）在用FK506后1、2、3、4周时的外周血T淋巴细胞亚群及其表面共刺激分子CD28、CD152和ICOS分子的表达情况，以健康志愿者（健康对照组）和患终末期肝脏疾病拟行肝移植者（肝病对照组）为对照。结果 CD3^＋T淋巴细胞在各组间的差异均无统计学意义（P〉0．05）。经FK506治疗后，肝移植患者的CD4^＋T淋巴细胞逐渐减少，CD8^＋T淋巴细胞逐渐增加，并恢复至健康对照组水平（P〉0．05）。FK506治疗组T淋巴细胞亚群表面CD28分子和ICOS分子表达逐渐下降，并明显低于健康对照组（P〈0．05），而CD152分子表达增加，且明显高于健康对照组（P〈0．05）；其ICOS分子表达水平的下降晚于CD28分子，CD4^＋CD28^＋T淋巴细胞、CD8^＋CD28^＋T淋巴细胞和CD4^＋ICOS^＋T淋巴细胞均呈现相近的变化规律。结论 FK506能迅速纠正移植受者T淋巴细胞亚群紊乱，并抑制正性共刺激分子CD28和ICOS的表达，促进负性共刺激分子CD152的表达。     

大面积烧伤脓毒症患者T淋巴细胞免疫功能的改变及临床意义

目的 了解大面积烧伤脓毒症患者T淋巴细胞免疫功能的变化，探讨其与脓毒症的关系。方法 选择59例烧伤面积≥30％TBSA的患者，分为脓毒症组43例和非脓毒症组16例。采集两组患者伤后1、3、5、7、14、21、28d的外周静脉血，检测T淋巴细胞增殖能力和白细胞介素2（IL-2）的分泌水平，并行相关性分析；通过流式细胞仪检测CD3^＋／CD4^＋ T淋巴细胞的百分率及其凋亡率，并行相关性分析。结果 与非脓毒症组比较，脓毒症组患者伤后l、14、2l、28dT淋巴细胞增殖能力和IL-2的分泌水平均显著下降（P〈0．05或P〈0.01），两指标呈显著正相关（r=0．82，P〈0．01）。伤后1、5、14、21、28d，脓毒症组患者CD3^＋／CD4^＋T淋巴细胞百分率明显低于非脓毒症组，而其凋亡率呈相反趋势（P〈0.05或P〈0．01），两指标呈显著负相关（r=-0.66，P〈0．05）。结论 大面积烧伤脓毒症患者T淋巴细胞免疫功能持续处于抑制状态，T淋巴细胞凋亡参与了脓毒症细胞免疫紊乱的病理生理过程。     

非小细胞肺癌患者围术期细胞免疫功能的变化及免疫治疗

目的观察围术期非小细胞肺癌患者细胞免疫功能的变化及应用胸腺肽α1后对机体免疫功能的影响,为临床应用免疫增强剂联合手术治疗非小细胞肺癌患者提供依据。方法将97例行肺叶或右全肺切除术的非小细胞肺癌患者分为两组,组1：围术期给予胸腺肽α1治疗;组2：围术期未给予胸腺肽α1治疗;对照组：另选择19例同期非肺癌而采取手术治疗的肺部疾病患者作为对照。采用间接免疫荧光法（IFCA）测定3组围术期T细胞亚群的百分率变化。结果术后第1d组1 CD4^＋T、CD4^＋T／CD8^＋T高于组2（CD4^＋T 36．92％±2．10％ vs．31．18％±7．64％;CD4^＋T／CD8^＋T 1．31±0．36 vs．1．09±0．32;P〈0．05）,术后第3d组1 CD4^＋T和CD4^＋T／CD8^＋T高于组2（CD4^＋T 45．66％±3．77％ vs．34．70％±8．42％;CD4^＋T／CD8^＋T 1．42±0．11 vs．1．14±0．20;P〈0．05）;术后第9d CD4^＋T、CD4^＋T／CD8^＋T高于组2（CD4^＋T 47．28％±1．96％ vs．39．12％±3．10％;CD4^＋T／CD8^＋T 1．46±0．14 vs．1．22±0．36;P〈0．05）;术后第16d组1 CD4^＋T、CD4^＋T／CD8^＋T与组2和对照组比较差异无统计学意义（P〉0．05）。结论非小细胞肺癌患者的免疫功能低下,应用胸腺肽α1后细胞免疫功能较快恢复至正常状态,对非小细胞肺癌患者早期采用手术、化疗／放疗的综合治疗有助于提高治疗效果。     

慢性乙型肝炎病毒感染者外周血T细胞亚群及NK细胞的特点及意义

目的探讨慢性乙型肝炎病毒（hepatitis B virus,HBV）感染者外周血T细胞亚群及NK细胞的特点及临床意义。方法采用流式细胞术检测各研究组,包括慢性乙型肝炎（chronic hepatitis B,CHB）组33例、乙型肝炎失代偿期肝硬化（1iver cirrhosis,LC）组20例、慢性乙型重型肝炎（chronic severe hepatitis B,CSH）组17例及健康对照组（Control）20例的外周血T细胞亚群及NK细胞相对计数,并检测肝功能、HBVDNA含量及HBV血清标志物。结果按Control、CHB、LC、CSH顺序,CD3^＋T细胞、CD8^＋T细胞百分比依次升高,而CIM^＋T细胞、CD4^＋／CD8^＋比值及NK细胞百分比依次降低,且CHB、LC、CSH组与Control组及CHB组与CSH组相比,差异均有统计学意义（P〈0．05或P〈0．008）。CHB患者的CD3^＋T细胞与血清总胆红素（total bilirubin,TB）、HBVDNA含量（log_10）呈正相关（P〈0．001;P〈0．001）;CD8^＋T细胞与HBVDNA含量（log_10）呈正相关（P=0．007）,NK细胞与HBVDNA含量（log_10）（P=0．001）呈负相关。CHB组乙型肝炎e抗原（HBeAg）阳性者的CD4^＋T细胞及CD4^＋／CD8^＋比值低于HBeAg阴性者（P=0．018;P〈0．001）,而HBVDNA含量（log_10）和CD8^＋T细胞高于HBeAg阴性者（P=0．012;P=0．019）。结论慢性HBV感染者外周血T细胞亚群及NK细胞相对值紊乱,且与临床类型、病情、血清HBVDNA水平及HBeAg相关。     

结肠癌患者外周血 CD4+ CD25+调节性 T细胞检测的临床意义

目的 探讨结肠癌患者外周血CD4^＋CD25^＋调节性T细胞检测的临床意义。方法采用流式细胞技术对51例结肠癌患者和30例健康体检者外周血淋巴细胞CD4及CD25进行了检测。结果（1）结肠癌组CD4^＋CD25^＋细胞明显高于正常对照组（P〈0．05），CD4^＋CD25^＋细胞则显著低于正常对照组（P〈0．05）；（2）结肠癌组手术后患者CD4^＋CD25^＋、CD4^-CD25^＋细胞与手术前相比显著下降（P〈0．05）；（3）结肠癌组淋巴结转移患者CD4^＋CD25^＋细胞明显高于未转移组（P〈0．001）。结论CD4^＋CD25^＋调节性T细胞数可以反映肿瘤患者免疫系统存在抑制状态，且可能与肿瘤的免疫耐受有关，并可反映肿瘤淋巴结转移状况。     

微创置管胸腔内注射顺铂及香菇多糖治疗恶性胸腔积液

目的：总结微创置管引流、胸腔内注射顺铂及香菇多糖治疗恶性胸腔积液的疗效。方法：70例患者按顺序分为治疗组（35例）和对照组（35例）,均采取留置中心静脉导管穿刺引流,治疗组胸腔内注射顺铂及香菇多糖,对照组注射顺铂。结果：治疗组、对照组有效率分别为88．6％、54．3％（P〈0．05）,治疗组胸水中CEA、CYFRA21—1、NSE浓度较治疗前明显下降,较对照组明显降低（P〈0．05）,外周血NK细胞活性,T淋巴细胞中的CD3^＋、CD4^＋及CD4^＋／CD8^＋比值明显增高（P〈0．05）。结论：微创置管引流、胸腔内注射顺铂及香菇多糖治疗恶性胸腔积液安全有效,具有创伤小、操作简便、痛苦少、对年老体弱患者也适用等特点.     

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.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

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.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

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.