腺病毒介导的人血管抑素基因治疗胰腺癌

目的观察腺病毒介导的人血管抑素基因对胰腺癌的治疗作用。方法通过病毒重组技术将人血管抑素基因克隆入增殖缺陷型腺病毒基因组中,获得腺病毒滴度达5．5×10~(10) pfu/ ml,观察转染表达后的生物学活性,通过建立裸鼠动物模型(每组数n=15例),分析基因转导后胰腺癌组织中血管抑素的表达情况及对肿瘤血管的抑制作用。结果构建了血管抑素的重组腺病毒载体pCA13-hAG；检测到血管抑素在体外mRNA水平和蛋白质水平表达率分别为87%和81%,得到279 bp电泳条带和38 000大小的蛋白条带；荷瘤裸鼠体内肿瘤体积显著低于对照组(P＜0．05),治疗组MVD为9．85±1．20,两对照组肿瘤微血管密度(MVD)分别为20．35±2．15、17,66±2．34 (P＜0．05)。结论所构建的pCA13-hAG重组腺病毒载体可有效表达具有生物学活性的血管抑素,使肿瘤内微血管生成减少,肿瘤细胞增殖减慢,为抗血管生成治疗实体瘤的临床应用奠定基础。     

增殖型腺病毒介导的人内皮抑素基因治疗胰腺癌

目的 观察携带人内皮抑素基因的双重调控增殖型腺病毒(AdTPHre-hEndo)对胰腺癌的治疗作用.方法 通过病毒重组技术将人内皮抑素基因克隆入双重调控增殖型腺病毒基因组中,获得腺病毒滴度为3.25×1010pfu/ml;通过建立SW-1990胰腺癌细胞Balb/c裸鼠皮下移植瘤模型,分析基因转导后胰腺癌组织中内皮抑素的表达情况及对肿瘤血管的抑制作用.结果 构建了AdTPHre-hEndo;AdTPHre-hEndo组荷瘤裸鼠肿瘤体积显著低于携带人内皮抑素基因的重组腺病毒(Ad-hEndo)组(P＜0.01)和选择性增殖型腺病毒(ONYX-015)组(P＜0.05);AdTPHre-hEndo组内皮抑素表达量明显高于Ad-hEndo组和对照组(P＜0.01).AdTPHre-hEndo组肿瘤微血管密度(MVD)为6.8±2.5,Ad-hEndo组和对照组MVD分别为16.0±4.6(P＜0.01)、47.2±10.0(P＜0.01).结论 所构建的AdTPHre-hEndo可有效表达具有生物学活性的内皮抑素,使肿瘤内微血管生成减少,肿瘤细胞增殖减慢,具备应用于胰腺癌临床治疗的潜力.     

血管生长抑素基因抑制胰腺癌裸鼠移植瘤血管生成的实验研究

目的:探讨人血管生长抑素基因对胰腺癌裸鼠移植瘤生长及血管生成的影响。方法:建立人胰腺癌细胞株BXPC-3裸鼠移植瘤模型,应用人血管生长抑素基因质粒转染胰腺癌裸鼠移植瘤,观察移植瘤生长情况。采用免疫组织化学技术检测肿瘤血管内皮生长因子(VEGF)表达情况和微血管密度(MVD)差异,透射电子显微镜观察肿瘤细胞情况。结果:治疗组肿瘤体积明显小于空白对照组和空质粒组(P<0.01),VEGF主要表达在肿瘤细胞的胞质内,治疗组、空白对照组和空质粒组平均灰度分别为179.57±5.22、150.87±3.44和163.40±3.54;阳性单位分别为14.94±2.26、31.26±2.72和29.21±2.95;MVD分别为10.60±74.56、19.33±2.52和18.67±5.29,治疗组与空白对照组和空质粒组比较,差异有统计学意义(P均<0.05)。电子显微镜下治疗组可见大量肿瘤细胞坏死。结论:人血管生长抑素基因能明显抑制胰腺癌裸鼠移植瘤血管生成,促进肿瘤细胞坏死,进而抑制肿瘤生长。     

新型血管生成抑制人内皮细胞抑制素-血管内皮细胞生长抑制因子151治疗胃癌的实验研究

目的研究重组腺病毒表达的人内皮细胞抑制素-血管内皮细胞生长抑制因子151(hENDO-VEGI151)融合蛋白对胃癌的抑制作用.方法构建携带hENDO-VEGI151融合基因的重组腺病毒载体,脂质体介导法包装重组腺病毒Ad IL-3/hENDO-VEGI151.体外检测融合基因的表达及融合蛋白的生物学活性.应用鸡胚绒毛尿囊膜(CAM)模型及荷人胃癌裸鼠模型,进一步观察融合蛋白对活体血管生成的影响和融合基因治疗活体胃癌的疗效.结果用TCID50法测定携带融合基因的重组腺病毒滴度为4.2×1011TCID50/ml;用聚合酶链反应(PCR)、逆转录(RT)-PCR和免疫组织化学方法证实融合基因可被转导入SGC-7901细胞内并稳定高效地转录和表达;Western blot显示融合蛋白可被分泌到胞外发挥作用;融合蛋白可强烈抑制ECV-304细胞生长及鸡胚绒毛尿囊膜新生血管形成.Ad IL-3/hENDO-VEGI151治疗可强烈抑制裸鼠体内种植瘤生长,明显下调肿瘤微血管密度,促进胃癌细胞凋亡.结论 hENDO-VEGI151是一条新型强效的肿瘤血管生成抑制基因,其表达产物可能通过作用于肿瘤新生血管形成的不同环节强烈抑制新血管生成和肿瘤生长,值得进一步研究.     

携带人内皮抑素基因的增殖型腺病毒AdTPHre-hE对胰腺癌的体内实验研究

目的通过建立裸鼠胰腺癌肿瘤模型,在体内实验中进一步证实携带人内皮抑素基因的增殖型腺病毒AdTPHre-hE的抗肿瘤作用.方法建立AsPC-1胰腺癌细胞BALB/c裸鼠皮下移植瘤模型,在瘤体内注射AdTPHre-hE治疗,观察肿瘤生长.ELISA法检测裸鼠血清中人内皮抑素浓度,肿瘤组织行Hexon单克隆抗体免疫组化染色及微血管免疫组化染色.结果AdTPHre-hE抑制肿瘤生长的作用显著强于Ad-hE(P＜0.01)和对照组(P＜0.01).随着治疗时间的延长,裸鼠血清中内皮抑素表达量不断增加,明显高于Ad-hE组(P＜0.01)和对照组(P＜0.01).病毒Hexon免疫组化染色显示,AdTPHre-hE治疗组移植瘤内可见片状或弥漫性分布的阳性染色,AdTPHre-hE治疗组瘤组织中微血管密度为16.3±4.3明显少于Ad-hE组的33.8±6.2(P＜0.01)和对照组的36.8±4.6(P＜0.01).结论增殖型腺病毒AdTPHre-hE介导人内皮抑素的表达,具有明显抑制肿瘤细胞生长的作用.     

鼠源性血管抑素对裸鼠种植性肿瘤的抑制作用

目的　探讨鼠源性血管抑素转染入人肝癌细胞SMMC 772 1后对裸鼠种植性肿瘤的影响。　方法　建立鼠源性血管抑素基因的人肝癌SMMC 772 1细胞株 ,实验动物分 3组 :空白对照组种植SMMC 772 1细胞 ,空载体组种植SMMC 772 1/pcDNA3 1(+)细胞 ,血管抑素组种植SMMC 772 1/pcDNA3 1 mAST细胞。比较各组裸鼠肿瘤体积、重量和肿瘤微血管密度 (MVD)。　结果　在肿瘤细胞种植 35d时裸鼠肿瘤体积 :空白对照组 (35 38 1± 6 43 3)mm3 ,空载体组 (312 8 5± 5 46 6 )mm3 ,血管抑素组 (75 5 8± 198 2 )mm3 ;肿瘤重量 :空白对照组 (6 0± 0 7)g,空载体组 (5 9± 0 5 )g ,血管抑素组(2 1± 0 5 )g;肿瘤MVD :空白对照组 5 2 2± 6 6 ,空载体组 49 4± 7 0 ,血管抑素组 2 5 5± 4 1。血管抑素组裸鼠肿瘤体积、重量和MVD显著小于空白对照组和空载体组 (P均 <0 0 1) ,肿瘤的抑制率达78 6 %。　结论　转染血管抑素基因的人肝癌细胞SMMC 772 1在裸鼠体内的致瘤力明显降低 ,肿瘤的体积、重量和微血管密度显著低于对照组 ,表明血管抑素可通过抑制肿瘤血管生成而显著抑制肿瘤生长     

生长抑素和KDR表达与胰腺癌血管形成关系及临床意义

目的:探讨人胰腺癌组织生长抑素和血管内皮生长因子受体KDR(kinase insert domain con-taining receptor)的表达与血管形成的关系及其临床意义.方法:采用免疫组织化学方法检测62例人胰腺癌组织生长抑素(somatostatin SS)和KDR的表达,并对CD34+血管进行微血管密度(MVD)计数,对KDR及SS表达阳性血管进行半定量计数.结果:胰腺癌组织KDR高、中表达组的MVD明显高于KDR低表达组(P<0.01);而在SS低表达组的MVD明显高于高、中表达组(P<0.01).KDR的表达与肿瘤大小及远处转移相关(P<0.05),SS的表达与肿瘤大小及分化程度有关(P<0.05),并且KDR与SS的表达存在明显负相关(P<0.01).MVD与肿瘤大小相关(P<0.05).结论:KDR、SS在胰腺癌组织中的表达与肿瘤血管形成及调控密切相关,与胰腺癌的发生、发展及转移可能密切相关,可作为评估胰腺癌患者预后的指标.     

CD/5-FC系统对胰腺癌裸鼠移植瘤的抗血管形成作用的初步探讨

目的　探讨自杀基因系统对胰腺癌裸鼠移植瘤的微血管形成的抑制作用。方法　构建含大肠杆菌胞嘧啶脱氨酶 (cytosinedeaminase ,CD)基因的腺病毒穿梭载体 pAdTrack CMV CD ,与骨架载体pAdEasy 1在细菌内重组为 pAd CD ,经 2 93细胞包装、扩增 ,氯化铯密度梯度离心制备纯化高效的CD腺病毒液 ,建立胰腺癌裸鼠皮下移植瘤模型 ,观察CD基因的原位治疗及微血管形成抑制情况。结果　含CD基因腺病毒载体经酶切鉴定正确 ,包装纯化后 ,检测病毒滴度为 2× 10 11pfu/ml,体内实验显示CD基因原位转导对裸鼠胰腺癌移植瘤的微血管形成具有较明显的抑制效应。结论　腺病毒介导CD/ 5 FC自杀基因系统 ,不仅可以直接杀灭癌细胞 ,而且还可通过抑制移植瘤微血管的形成来抑制胰腺癌细胞的生长 ,可作为胰腺癌基因治疗的有效方法。     

环氧合酶2对胰腺癌新生血管生成的调节作用及其机制

目的　探讨环氧合酶 2 (COX 2 )在胰腺癌新生血管生成中的调节作用及其作用机制。方法　应用免疫组织化学染色研究人胰腺癌组织COX 2、血管内皮细胞生长因子 (VEGF)表达 ;同时标记肿瘤新生血管内皮细胞vWF和血管壁Ⅳ型胶原 ,计算肿瘤组织微血管密度 (MVD)。建立裸鼠胰腺癌细胞株PC 3移植瘤 ,观察选择性COX 2抑制剂Celebrex对肿瘤组织MVD的影响 ,并应用免疫组织化学染色和逆转录聚合酶链式反应 (RT PCR)研究裸鼠移植瘤组织VEGF表达变化。结果　COX 2在人胰腺癌组织中表达阳性率为 87 5 % ,VEGF阳性率为 5 8 3%。COX 2强阳性组MVD平均值显著高于COX 2弱阳性 +阴性组 ,P <0 0 1。VEGF阳性组MVD平均值高于VEGF阴性组 ,但无统计学差异 ,P >0 0 5 ;Pearson相关性检验结果表明COX 2与vWF和Ⅳ胶原标记的MVD均有明显的相关性 (相关系数分别为 0 5 99和 0 6 ) ,P <0 0 5。在裸鼠移植瘤的体内实验中 ,与对照组MVD(6 3 89± 13 6 7)相比 ,Celebrex处理组MVD为 32 2 5± 12 99,两者差异显著 ,P <0 0 1。免疫组织化学染色和RT PCR结果表明Celebrex处理组肿瘤组织VEGF表达较对照组明显下调。结论　COX 2与胰腺癌新生血管生成密切相关 ,其高表达促进了胰腺癌新生血管生成 ;可能作用机制是上调促血管生成因子VEGF     

血管内皮生长因子受体启动子双自杀基因治疗乳腺癌

目的 探讨腺病毒介导的KDRP-CD/TK融合基因对乳腺癌裸鼠体内抑瘤作用的特点.方法 以MCF-7细胞株建立裸小鼠乳腺癌动物模型,随机分为Ⅰ组[注射重组腺病毒AdKDRP-CDglyTK与前药5-氟胞嘧啶(5-FC)与丙氧鸟苷(GCV)]、Ⅱ组(仅注射前药5-FC与GCV)、Ⅲ组(仅注射重组腺病毒AdKDRP-CDglyTK)及Ⅳ组(空白对照,不施加任何处理).治疗结束后,计算抑瘤率、常规病理检查、逆转录-聚合酶链反应(RT-PCR)检测瘤体CD/TK融合基因的表达以及微血管密度(MVD)变化的检测,同时观察该治疗体系有无系统毒性.结果 各组瘤重如下:Ⅰ组(实验组)(25.04±3.09)mg、Ⅱ组(498.07±4.47)mg、Ⅲ组(501.94±4.50)mg、Ⅳ组(503.79±6.27)mg.可见Ⅰ组肿瘤逐渐缩小,余各组肿瘤逐渐增大(F=12 727.420,P＜0.01);第Ⅱ、Ⅲ、Ⅳ组肿瘤生长差异无统计学意义(P＞0.05);Ⅰ组有CD/TK基因表达且MVD(1.05±0.04)较对照组(4.15±0.10)变小(t=64.126,P＜0.01);常规病理检查发现Ⅰ组组织片状坏死,且该治疗体系对重要脏器无毒性作用.结论 KDR启动子驱动双自杀基因体系对裸鼠皮下移植瘤有明显的生长抑制作用,其机制涉及对肿瘤及其血管内皮细胞的双重杀伤.     

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.     

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.     

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.