肝细胞癌合并肝硬化患者肝脾联合切除术后免疫功能变化的研究

目的　探讨肝细胞癌合并肝硬化患者肝癌切除时联合脾切除术后免疫功能的变化。方法　将 16例肝癌合并肝硬化患者分成 2组 ,即肝癌切除联合脾切除组 ( 7例 )和单纯肝癌切除组 ( 9例 ) ,于术前、术后 2个月取外周血 7ml,采用流式细胞仪检测CD4、CD8、CD4 /CD8,ELISA法检测IL 2、IFN γ、IL 10。　结果　 2组患者术前CD4、CD8、CD4 /CD8、IL 2、IFN γ、IL 10水平差异无显著性 ;术后 2个月 ,切脾组CD4 ( 3 8 2 %± 3 7% )、CD4 /CD8( 1 7%± 0 3 % )高于保脾组CD4 ( 3 2 5 %± 4 0 % )、CD4 /CD8( 1 1%± 0 1% ) ,而CD8( 2 3 7%± 3 7% )低于保脾组CD8( 2 9 4 %± 4 0 % ) (P <0 0 5 ) ;切脾组IFN γ[( 10 4 4± 14 9)pg/ml]、IL 2 [( 98 6± 18 6)pg/ml]高于保脾组 [IFN γ( 70 5± 12 6)pg/ml、IL 2 ( 80 9± 13 5 )pg/ml],而IL 10 [( 5 5 5± 11 2 )pg/ml]低于保脾组 [IL 10 ( 89 4± 10 )pg/ml](P <0 0 5 )。　结论肝癌切除时联合脾切除不但没有降低机体T细胞亚群和Th细胞的平衡 ,反而促进其恢复平衡 ,并改善机体抗肿瘤免疫功能     

肝癌合并肝硬化患者肝癌切除后机体免疫状态的变化

目的探讨肝癌合并肝硬化患者癌灶切除前后机体免疫状态的变化。方法以肝硬化患者为对照组 ,采用流式细胞技术 (FCM)及ELISA方法分析 18例中晚期肝癌合并肝硬化患者癌灶切除前后外周血T细胞亚群CD4、CD8、CD4 /CD8及Th1/Th2细胞因子IFN γ、IL2、IL10蛋白水平的变化。结果　肝癌切除术后CD4 (33± 3) %、CD4 /CD8(1 1± 0 1)、IL2 (71± 11)pg/ml、IFN γ(90± 15 )pg/ml回升 ,高于术前水平〔CD4 (2 9± 4 ) %、CD4 /CD8(0 9± 0 3)、IL2 (5 7± 15 )pg/ml、IFN γ(78± 13)pg/ml〕 ,但仍低于肝硬化组〔CD4 (37± 4 ) %、CD4 /CD8(1 3± 0 2 )、IL2 (82± 15 )pg/ml、IFN γ(10 4± 2 2 )pg/ml〕(P <0 0 1或P <0 0 5 ) ;CD8(32± 3) %、IL10 (70± 9)pg/ml下降 ,低于术前〔CD8(35± 6 ) %、IL10(81± 15 )pg/ml〕水平但高于肝硬化组〔CD8(2 9± 2 ) %、IL10 (6 1± 10 )pg/ml〕(P <0 0 5 )。结论　癌灶切除后 ,机体免疫功能有明显改善。但仍未恢复到肝硬化患者的水平。     

白细胞介素-18与癌细胞裂解物修饰的树突状细胞疫苗对胰腺癌的免疫治疗作用

目的　观察经白细胞介素 18(IL 18)和胰腺癌细胞裂解物修饰的树突状细胞 (DC)疫苗对胰腺癌荷瘤小鼠的免疫治疗作用。方法　用药物诱导制成BALB/c小鼠的胰腺癌模型。通过IL 18和癌细胞裂解物修饰小鼠DC(MTSC4) ,制成DC疫苗 ,检测各组血清中细胞因子IL 18、干扰素γ(IFN γ)的浓度 (分为DC IL18 裂解物组 ,DC 裂解物组 ,DC IL 18组 ,DC组 ,PBS组 ) ,研究了其对小鼠胰腺癌的免疫治疗作用。结果　DC IL18 裂解物组中IL 18与IFN γ的浓度 ( 2 161± 43 9)μg/L和 ( 4 3 5± 72 ) μg/L ,与其余各组比较差异有显著性 (P <0 .0 5 ,P <0 .0 1)。DC IL18 裂解物组接种胰腺癌细胞后 5 0d均未见移植肿瘤形成 ,与其余各组比较差异有非常显著性 (P <0 .0 1)。对胰腺癌细胞的细胞毒作用以DC IL18 裂解物组最强 ,DC 裂解物组次之 ,DC IL18组较弱 ,其余 2组则缺乏 (P <0 .0 1)。DC IL18 裂解物组的小鼠的生存期比他各组明显延长 ,且肿瘤的重量比其他各组明显减轻 (P <0 .0 1,P <0 .0 5 )。结论　IL 18和胰腺癌细胞裂解物修饰的DC疫苗对胰腺癌荷瘤小鼠有明显的免疫治疗作用。     

茯苓醇提取物抗心脏移植急性排斥反应的实验研究

目的　研究茯苓醇提取物对心脏移植急性排斥反应的抑制作用。方法　以Wistar大鼠为供者、SD大鼠为受者 ,建立异位 (腹腔 )心脏移植模型 ,移植前按组分别以橄榄油、茯苓醇提取物及环孢素A灌胃 ,并设SD大鼠空白对照组。术后观察移植心的存活时间 ,测定各组术后第 7d外周血中白细胞介素 2 (IL 2 )和γ干扰素 (IFN γ)含量以及CD3+、CD4 +、CD8+细胞和CD4 +细胞与CD8+细胞的比值 (CD4 +/CD8+) ,并观察移植心的病理变化。结果　接受茯苓醇提取物 2 5mg·kg-1·d-1或 5 0mg·kg-1·d-1灌胃的大鼠 ,移植心存活时间显著延长 ,病理损害程度减轻 ,外周血IL 2及IFN γ的含量以及CD3+、CD4 +、CD8+细胞百分比和CD4 +/CD8+比值降低 ,与环孢素A 5mg·kg-1·d-1灌胃的结果相当。结论　茯苓醇提取物对心脏移植急性排斥反应具有明显的抑制作用。     

应用MAGE-3抗原肽诱导肝癌患者细胞毒T淋巴细胞反应的研究

目的研究MAGE 3抗原肽对肝细胞癌 (HCC)患者进行免疫治疗的可行性。方法微量细胞毒法检测HCC患者中HLA A2表达情况 ,RT PCR方法检测肝癌组织MAGE 3基因mRNA表达情况。用免疫磁珠从患者外周血单个核细胞 (PBMC)中分离出CD8阳性细胞作为效应细胞 ;将其余自体CD8阴性的PBMC与MAGE 3抗原肽 (FLWGPRALV)短暂孵育 ,经γ射线照射后作为抗原呈递细胞 (APC) ,与CD8阳性效应细胞进行混合淋巴细胞培养 ,作为实验组 ,7d后再加入APC刺激患者效应细胞 1次。每周计数效应细胞数量 ,培养第 15天时作为细胞毒T淋巴细胞 (CTL)检测其杀伤活性。以表达MAGE 3和HLA A2的肝癌细胞系HLE作为靶细胞 ,采用IFN γ细胞因子分泌法 ,通过流式细胞仪检测具有分泌γ 干扰素 (IFN γ)的CD8阳性细胞的频数来反映CTL的杀伤活性。另设不加APC刺激的CD8阳性细胞 ,加IL 2培养作为对照组。结果本组 2 5例HCC患者中 9例HLA A2阳性表达 ;9例中 3例MAGE 3基因mRNA阳性表达 ,6例阴性表达。培养开始时 ,效应细胞为 1 0× 10 6/孔 ,2周后细胞增殖 4～ 6倍。分泌IFN γ的CD8阳性细胞的频数 ,3例MAGE 3阳性患者平均为 2 2 0 % ,6例阴性患者为 0 5 % ,两组间差异有非常显著意义 (P <0 0 1)。结论本实验结果表明 ,应用MAGE 3抗原肽 ,能在体外从HCC患者     

门脉高压症患者脾切除术后免疫功能的改变及其与脾组织免疫细胞的关系

目的　研究门脉高压症脾亢患者脾切除前后免疫功能的改变 ,以及巨脾组织免疫活性细胞的数量变化。探讨门脉高压症脾亢患者脾脏切除术合理性的免疫学基础。方法　对门脉高压症脾切除术患者 ,术前检测静脉血T淋巴细胞亚群 (CD3 、CD4 、CD8 、CD2 0 )及NK细胞 ;白介素 2(IL 2 )和白介素 10 (IL 10 ) ;γ干扰素 (IFN γ) ;免疫球蛋白 (IgG、IgM、IgA)及补体C3、C4。脾切除术后 1周、1月再次检测上述指标。切除的巨脾组织制成石蜡切片 ,检测CD3 、CD8 、CD2 0 、CD6 8 阳性细胞数量及分布 ,与正常脾组织进行比较。结果　①脾切除术后 1月免疫球蛋白IgG、补体C3、C4均升高 (P <0 .0 5 ) ,IgM、IgA呈增高趋势 ,但无统计学意义。②脾切除术后 1月IL 2、IFN γ明显升高 ,但仍低于正常人 ;IL 10明显降低 ,但仍高于正常人。③脾切除手术前后外周血CD4 、CD8 、CD4 /CD8 、CD2 0 细胞变化均无统计学意义。仅CD3 、NK细胞术后 1月明显升高 (P <0 .0 1)。④门静脉高压症巨脾与正常脾脏比较 ,CD3 、CD8 、CD2 0 、CD6 8 细胞数均减少。结论　经部分免疫学指标检测 ,门脉高压症脾亢患者免疫功能降低 ,脾切除术能使门脉高压症患者免疫功能得到一定改善。     

CD4+CD25+Treg细胞对肿瘤特异性CTL杀伤效果的影响

目的 探讨CD4+CD25+Treg细胞对肿瘤特异性细胞毒T细胞(CTL)杀伤效果的影响及机制.方法 将C57BL/6小鼠80只随机分为4组,每组20只.A组:树突状细胞(DC)与T细胞共同培养前删除CD4+CD25+Treg;B组:DC与T细胞共同培养后删除CD4+CD25+Treg;C组:DC与T细胞共同培养时不删除CD4+CD25+Treg;对照组:无DC诱导的T细胞.应用脾脏来源DC细胞诱导T细胞制备CTL,在CTL形成的不同时期采用MACS法删除CD4+CD25+Treg.应用噻唑蓝(MTY)比色法检测不同组别CTL对B16黑色素瘤细胞的杀伤效果.同时应用酶联免疫吸附试验(ELISA)法检测细胞培养液中白细胞介素(IL)-2、干扰素(IFN)-γ含量变化.结果 3组实验组CTL杀伤率明显高于对照组(P<0.05).删除CD4+CD25+Treg的A组、B组CTL杀伤率明显高于未删除的C组(P<0.05).但CTL形成的不同时期删除CD4+CD25+Treg对CTL杀伤率的影响无统计学意义(P>0.05).IL-2、IFN-γ含量变化与杀伤率呈现相同的变化趋势.结论 删除CD4+CD25+Treg细胞可明显提高CTL的杀伤效果,是消除肿瘤免疫耐受机制的新途径.     

白细胞介素-7促进CD8+T细胞干扰素-γ的分泌增强小鼠抗乳腺肿瘤的免疫效应

目的 观察白细胞介素(IL)-7是否通过促进CD8+T细胞干扰素-γ(IFN-γ)分泌来增强小鼠抗乳腺肿瘤的免疫效应.方法 荷瘤小鼠瘤体内直接注射IL-7真核表达质粒(pcDNA3-IL-7);免疫磁珠分选CD4+T、CD8+T细胞并体外培养;流式细胞仪检测细胞内干扰素(IFN)-γ的分泌量;酶联免疫吸附试验(ELISA)检测培养上清IFN-γ的量;噻唑蓝(MTT)法检测CD8+T细胞体外杀伤活性;小鼠体内预先注射anti-CD8抗体阻断活化.结果 pcDNA3-IL-7注射组CD8+T细胞内IFN-γ(38.6±4.4)％、CD8+T细胞培养上清IFN-γ( 136.0±11.2) ng/L,与对照组比较,pcDNA3-IL-7明显促进CD8+T细胞IFN-γ表达量(P＜0.05);IL-7处理过的荷瘤小鼠CD8+T细胞杀伤活性显著增强,尤其效靶比为100∶1;小鼠体内预先注射anti-CD8抗体阻断CD8+T细胞活化,显著抑制IL-7抗瘤效应(P＜0.05).结论 IL-7通过促进小鼠体内CD8+T细胞分泌IFN-γ介导抗瘤效应,从而增强小鼠机体抗乳腺肿瘤的免疫反应.     

gp96多肽复合物对树突状细胞成熟的影响

目的研究热休克蛋白gp96多肽复合物与小鼠骨髓来源的树突状细胞（DC）成熟的关系。方法采用GM-CSF、IL-4刺激培养小鼠骨髓细胞，增殖产生大量DC；从小鼠肝癌细胞株H22细胞中提取gp96肽复合物，体外修饰DC；通过流式细胞仪检测上清液IL-12、TNF-α细胞因子含量和DC表面主要组织相容性Ⅱ类抗原、CD40、CD80等分子表达；DC与小鼠脾淋巴细胞共同培育后，检测CD4、CD8和IFN-γ、IL-10双阳性细胞比例；以^51Cr释放法测定细胞毒性T淋巴细胞（CTL）杀伤活性。结果gp96多肽复合物修饰的DC大量分泌IL-12、TNF-α等细胞因子，高表达MHCⅡ类抗原、CD40、CD80等分子；并且能激活小鼠脾淋巴细胞，CD8^＋-IFN-γ^＋和CD4^＋-IFN-γ^＋双阳性细胞比例显著升高；能够特异性的杀伤H22癌细胞。结论gp96多肽复合物能够诱导DC成熟，体外产生特异性CTL反应。     

抑制Tregs增强DC/HCC融合疫苗诱导抗肝癌免疫反应的研究

目的 通过抑制荷瘤小鼠体内调节性T细胞(TregFoxp3+),探讨其增强DC/HCC融合细胞疫苗诱导抗肝癌免疫作用的相关机制.方法 皮下建立小鼠肝癌模型,24只小鼠随机分为4组:(1)环磷酰胺联合疫苗组[环磷酰胺(CTX)+ VAC];(2)疫苗组(VAC);(3)单纯环磷酰胺组(CTX);(4)对照组.各组治疗后,取外周血测定CD8+及CD4+淋巴细胞比例,同时取肿瘤组织及脾脏组织分别行苏木素-伊红(HE)染色和免疫组织化学观察肿瘤坏死和CD8+细胞及Treg+细胞的浸润,并用细胞计数试剂盒(CCK-8)检测脾脏淋巴细胞特异性细胞毒T淋巴细胞(CTL)活性.结果 与其他各组比较,CTX+ VAC组外周血CD4+及CD8+细胞比例增高[ CTX+ VAC:17.50％、14.69％;VAC:16.17％、13.07％;CTX:12.17％、11.59％;对照组:12.24％、11.16％];肿瘤组织可见大量肿瘤细胞坏死,脾脏组织中Foxp3+细胞浸润减少,CD8+细胞浸润增高,CTL对肿瘤细胞杀伤作用明显增强(P＜0.05).结论 通过CTX抑制荷瘤小鼠微环境及外周血中的Treg细胞,可以明显增强DC/HCC融合疫苗对肿瘤的杀伤作用.     

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.     

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.     

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.     

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.     

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.     

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.