维生素E酯预处理对小鼠原位脂肪肝移植的影响

目的　探讨供者用维生素E酯 (VES)预处理对原位小鼠脂肪肝移植的保护作用及其机理。方法　建立小鼠原位肝移植模型。随机分为正常小鼠对照组 (n =8)、肥胖小鼠对照组 (n =8)、非脂肪肝移植组 (n =12 )、脂肪肝移植组 (n =12 )、VES预处理脂肪肝移植组 (n =12 )。术后检测各组血清丙氨酸转氨酶 (ALT)、天冬氨酸转氨酶 (AST)相对水平 ;肝脏组织HE染色 ,油红O染色脂肪定量 ,ATP含量及解偶联蛋白 2 (UCP 2 )水平。结果　VES预处理脂肪肝移植组移植后 2h存活率为4 5 % ,而脂肪肝移植组为 2 5 % ,差异有显著性 (P <0 .0 5 ) ;VES预处理脂肪肝移植组血清ALT与AST水平与ATP浓度分别为 (32 33± 10 6 5 )U/L、(4386± 92 4 )U/L、0 .19± 0 .0 1,而脂肪肝移植组分别为 (832 0± 4 6 5 5 )U/L、(6 4 94± 2 6 5 5 )U/L、0 .13± 0 .0 1,差异有显著性 (P <0 .0 5 ) ;VES预处理脂肪肝移植组肝细胞损伤程度明显减轻 ,线粒体UCP 2水平低于脂肪肝移植组。结论　维生素E酯预处理对小鼠脂肪肝移植有一定保护作用。     

小鼠原位脂肪肝移植模型的建立

目的　建立了ob/ob小鼠脂肪肝移植模型 ,探讨保证建模成功的关键因素。方法　采用小鼠非动脉化肝移植技术 ,5～ 7周肥胖小鼠为供体 ,正常小鼠为受体 ,双袖套法行原位肝移植。受体肝组织行HE染色和油红O染色 ,血清ALT、AST水平检测采用常规生化分析法。结果非脂肪肝移植组 (lean to lean)受体长期存活率 (n =10 )为 70 % ,脂肪肝移植组 (ob/obtoagematchedlean)受体存活率为 0 (n =10 ) ,差异有显著性 (P <0 .0 5 )。脂肪肝移植给体积相当的正常小鼠 ,其短期存活率为 3 0 % (n =10 ) ,所有小鼠术后存活并苏醒 ,但均未超过 2 4h。脂肪肝移植受体ALT水平为 (62 85± 2 93 7)U /L ,AST为 (5 812± 2 942 )U /L ;而正常小鼠移植组ALT与AST水平分别为 (5 96± 114 )U /L ,(1796± 870 )U/L ,差异有显著性 (P <0 .0 5 ) ,组织学检测显示大量胆管中央凝固性坏死伴出血。结论　该模型的成功建立为我们提供了一种新的肝原发性肝无功能移植模型 ,为脂肪肝移植后脂肪肝细胞受损的机制研究奠定了基础。     

大鼠肝癌肝移植模型的建立

目的　建立肝癌肝移植动物模型并观察术后肝癌复发的生物学特点。方法　 130只近交系SD雄性大鼠 ,10 0ppm二乙基亚硝胺饲喂诱癌。共 98只大鼠据Kamada袖套技术行原位肝移植 ,术中根据肿瘤大小分为三组 :1组有明确肝癌结节但直径 <1 0cm (n =2 5 ) ,2组肝癌结节直径1 0～ 1 5cm(n =4 1) ,3组肝癌结节直径 >1 5cm(n =32 )。不行肝移植术的 10只大鼠作对照组。结果　三组大鼠肝移植术中死亡率 2 6 5 % (2 6 / 98) ,术后 30d累计死亡率 71 5 % (70 / 98)。术后存活 30d后计算平均生存期 ,1组 (81 3± 33 2 )d ,2组 (6 7 6± 2 4 9)d ,3组 (5 4 4± 2 4 9)d。对照组从诱癌开始 15 0d后计算 ,平均生存期为 (2 9 4± 12 9)d。术后肝癌复发率 35 7% (10 / 2 8) ,单纯移植肝内复发7 1% (2 / 2 8) ,肝和肺同时复发 10 7% (3/ 2 8) ,肝和腹腔同时复发 3 6 % (1/ 2 8) ,单纯腹腔肿瘤 7 1% (2 /2 8) ,单纯肺部肿瘤 7 1% (2 / 2 8)。结论　大鼠肝癌肝移植良好地模仿了临床过程 ,但诱癌大鼠体质差导致术中和术后短期死亡率高。大鼠术后长时间存活是观察到肿瘤复发的重要条件 ,肝癌复发的形式多样。该模型为肝癌肝移植术后抗复发和复发机制研究提供了极好的平台。     

还原型谷胱甘肽和供氧对伴有脂肪变性的供肝移植后肝细胞凋亡及超微结构的影响

目的探讨还原型谷胱甘肽 (GSH)和冷保存时供氧对脂肪变性供肝移植术后肝细胞凋亡及超微结构的影响。方法大鼠喂饲 79%标准饲料加 2 0 %猪油加 1%胆固醇 ,同时以 5 0 %酒精灌胃 1ml·10 0g-1·d-1,6周后诱导形成Ⅱ级脂肪变性供肝 ;GSH和静脉供氧预处理后行肝移植 ,正常供肝作对照 ;观察术后存活率、肝细胞凋亡、微循环及超微结构改变。结果大鼠脂肪变性供肝移植术后 3d肝细胞坏死率为 (38± 10 ) % ,凋亡率 (2 2± 11) % ;而给予预处理后坏死减少 (17± 6 ) % ,凋亡增多 (33± 8) % ;同时肝细胞内线粒体水肿减轻、肝窦内皮细胞损伤减少 ;微循环由 (5 96± 0 2 6 )伏 (相对值 )增为 (7 73± 0 4 3)伏 ;预处理后的脂肪变性供肝移植 1周存活率由 2 5 % (2 /8)提高到 6 2 % (5 /8) ,(χ2 =4 0 7,P =0 0 4 36 )。结论GSH和静脉供氧可通过减轻肝细胞线粒体损伤、减少肝窦破坏、改善微循环而提高大鼠脂肪变性供肝移植的存活率。     

Pannexin1,2在小鼠睾丸癌I-10细胞和睾丸间质细胞TM3中的表达及通道功能调控

目的:探讨泛连接蛋白(Panx)蛋白在小鼠睾丸癌I-10细胞与睾丸间质细胞TM3中的表达水平及其功能调控。方法:Western印迹法检测Panx-1和Panx-2蛋白在睾丸癌细胞中的表达水平;使用Panx通道抑制剂100μmol/L的甘珀酸(CBX)、200μmol/L的丙磺舒(PBN)作用于I-10细胞后,采用实时荧光法检测细胞间荧光传递能力;化学发光法检测细胞外ATP浓度;分别干扰(shRNA)和过表达(m Panx-1) Panx-1基因,调控Panx-1蛋白的表达及功能。结果:Western印迹结果显示,与TM3细胞相比,I-10细胞中Panx-1和Panx-2的表达量分别增加(289. 5±55. 8)%(P 0. 05)和(264. 5±24. 6)%(P 0. 05);采用CBX和PBN处理后,实时荧光实验和化学发光法结果显示,与对照组相比,CBX组和PBN组平均荧光物质转运量下降(87. 5±17. 7)%和(89. 3±14. 3)%(P0. 01),细胞外ATP水平在8、16、24 h时分别下降(57. 3±7. 2)%、(56. 4±9. 6)%,(63. 4±6. 4)%、(61. 7±2. 5)%,(35. 8±1. 6)%、(13. 5±8. 3)%(P 0. 01); shRNA和m Panx-1处理后,Western印迹结果显示,与阴性对照组相比,shRNA1和shRNA2组中Panx-1的表达量下降(38. 3±5. 2)%和(31. 8±5. 1)%(P 0. 01),m Panx-1组Panx-1的表达量增加(128. 4±7. 5)%(P 0. 01),且实时荧光实验和化学发光法结果显示,shRNA组荧光物质转运量下降(72. 4±39. 4)%(P 0. 01)和细胞外ATP含量在8、16、24 h分别下降(14. 7±0. 1)%、(13. 7±0. 3)%、(13. 1±0. 3)%(P 0. 01); m Panx-1组荧光物质转运量增加(122. 5±. 17. 1)%(P 0. 01)和细胞外ATP含量在8、16、24 h分别增加(886. 1±82. 1)%、(885. 8±83. 3)%、(841. 5±21. 8)%(P 0. 01)。结论:Panx-1和Panx-2在小鼠睾丸癌I-10细胞中表达增多,CBX和PBN及shRNA抑制Panx通道后,睾丸癌I-10细胞荧光传递能力减弱和细胞外ATP水平下降。     

解耦联蛋白-2基因敲除减轻高脂饮食诱导小鼠脂肪肝缺血再灌注损伤

目的 观察解耦联蛋白-2(UCP-2)基因在脂肪肝缺血再灌注损伤中的作用,探讨以UCP-2为靶点的脂肪供肝预处理新途径.方法 实验动物分为3组:实验组(A组):UCP-2基因敲除小鼠,给予高脂饮食(n=20);空白对照组(B组):野生型同系小鼠,给予正常饮食(n=20);阴性对照组(C组):野生型同系小鼠,给予高脂饮食(n=20).喂养6个月,建屯小鼠脂肪肝模型.各组小鼠阻断门静脉缺血15 min,再灌注24 h后处死,检测肝组织中UCP-2基因表达及三磷酸腺苷(ATP)、活性氧族(ROS)、乳酸脱氢酶(LDH)水平;并行血清丙氨酸转氨酶(ALT)、天门冬氨酸转氨酶(AST)检测及肝组织病理学检测.结果 高脂饮食喂养6个月后成功建立小鼠脂肪肝模型;Western blot证实A组小鼠UCP-2无表达,C组表达明显高于B组;A组ALT、AST、ATP、ROS、LDH的定量值为:(55.33±5.51)、(128.33±7.02)U/L、(28.00±2.00)nmol/L、(165.33±7.09)、(1176.00±22.27)U/pmt;B组上述指标为(25.00±4.58)、(85.33±4.51)U/L、(24.33±4.16)nmol/L、(147.33±7.51)、(707.33±31.64)U/prot;C组为(142.67±13.01)、(220.67±7.02)U/L、(8.67±1.53)nmol/L、(65.00±5.00)、(1748.33±42.52)U/prot,A组和C组差异有统计学意义(P<0.05);病理检测表明A组损伤轻于C组.结论 抑制解耦联蛋白-2基因表达能在减轻小鼠脂肪肝急性损伤.     

δ胆红素在肝移植术后早期的变化规律及价值

目的　探讨血清δ胆红素 (δB)在肝移植术后早期的变化规律及临床意义。　方法　 2 7例原位肝移植 ,按并发症有无分为 :病情平顺组 ( 10例 ) ,急性排斥反应组 ( 8例 ) ,两组合并为痊愈组 ( 18例 ) ,其余为围手术期死亡组 ( 9例 )。比较各组病人术后每日血清δB的变化。　结果　术后δB占总胆红素 (Totalbilirubin ,TB)的百分比 (δB % ) ,病情平顺组病人逐渐升高 ,2 1天时达 ( 37 5± 11 2 ) %。急性排斥反应发生后 ,δB %由 ( 2 6 4± 9 8) %下降至 ( 2 0 2± 12 7) % (n =8,t=2 12 ,P =0 0 7) ,TB、结合胆红素 (Conjugatedbilirubin ,CB)峰值比排斥反应前基值显著升高 (t=3 75 ,P =0 0 0 7;t=3 5 9,P =0 0 0 9)。术后 14天痊愈组δB % (n =18)明显高于死亡组 (n =9) ,分别为 ( 33 4± 12 2 ) %和 ( 2 2 0± 10 0 ) % (t=2 4 2 ,P =0 0 2 )。　结论　术后 14天时δB %与病人出院时转归有关。在排斥反应的诊断方面 ,血清TB和CB比δB %有更大优势。     

肝脏恶性肿瘤682例手术治疗分析

目的　探讨影响肝脏恶性肿瘤患者手术治疗后长期生存的因素。方法　回顾性分析1989年 1月至 2 0 0 3年 1月施行外科手术治疗的 6 82例肝脏恶性肿瘤患者的临床资料。结果　小肝癌 (直径 <5cm ,n =2 96 )患者术后 3年、5年生存率分别为 (6 1 2 5± 4 4 1) %和 (5 3 84± 5 6 8) % ,巨大肝癌 (直径 >10cm ,n =14 5 )患者术后 3年、5年生存率分别为 (45 90± 6 98) %和 (30 2 1±10 2 3) % ;肿瘤单发患者 (n =4 0 3)术后 3年、5年生存率分别为 (6 1 86± 3 6 9) %和 (5 5 4 0±4 91) % ,肿瘤多发 (2个或 2个以上 )患者 (n =2 4 6 )术后 3年、5年生存率分别为 (38 31± 4 97) %和(2 8 0 1± 6 31) % ;术前肝功能Child分期为Ⅰ期的患者 (n =397)术后 3年、5年生存率分别为 (6 0 6 8± 3 6 8) %和 (5 0 99± 5 10 ) % ,Ⅱ期或Ⅱ期以上的患者 (n =2 85 )术后 3年、5年生存率则为 (43 0 1±5 33) %和 (36 39± 7 5 8) % ;行局部或一段切除的患者 (n =2 98)术后 3年、5年生存率分别为 (6 8 6 5± 4 95 ) %和 (6 5 38± 5 6 9) % ,行两段或两段以上及半肝切除的患者 (n =32 4 )术后 3年、5年生存率分别为 (49 88± 4 13) %和 (37 98± 5 70 ) %。结论　小肝癌     

早期乳腺癌保留乳房和切除乳房的疗效观察

目的　评价早期乳腺癌保留乳房和切除乳房两种治疗方法的疗效。方法　 14 8例早期乳腺癌患者分保留乳房组 (保乳组 ,n =46 )和切除乳房组 (切乳组 ,n =10 2 )。前者行乳房的局部切除加腋淋巴结清扫 ,后者行乳房改良根治术。结果　 139例患者获得随访 ,随访期 3～ 13年。两组 3年、5年、10年的生存率分别为 10 0 %、87.88%、73.6 8%和 10 0 %、85 .92 %、75 .0 0 % ,局部复发率分别为 6 .98%、9.0 9%、5 .2 6 %和 7.2 9%、8.45 %、7.5 0 % ,远处转移率分别为 2 .33%、12 .12 %、10 .5 3%和 3.13%、12 .6 8%、12 .5 0 %。两组各指标差异无显著 (P >0 .0 5 ) ;而保留乳房组手术创伤小 ,乳房美观满意率 81.4% ,与后者相比差异有显著性 (P <0 .0 1)。结论　与乳房的改良根治术相比 ,乳房的局部切除腋淋巴结清扫加根治性放疗对于早期乳腺癌疗效可靠 ,生活质量提高 ,是一种安全、有效的方法 ,但应有严格适应证。     

赛尼哌在肝移植中的应用探讨

目的研究赛尼哌在肝移植患者中应用的安全性和有效性 ,探讨其在肝移植中的合理应用方案。方法对 2 0 0 1年 3月到 2 0 0 3年 2月间 5 0例有肾功能不全或有肾功能不全高危因素的肝移植患者应用赛尼哌情况进行回顾性研究。结果与对照组相比以下时期血肌酐水平显著增高 :移植前 (12 6± 5 5 )mmol/L ,P =0 0 0 2 7;术后第 1天 (16 4± 6 0 )mmol/L ,P =0 0 0 14 ;术后第 7天(12 0± 2 8)mmol/L ,P =0 0 179。术后第 14天 (99± 2 6 )mmol/L与对照组比差异无显著意义 ,P =0 4 0 0 7。应用赛尼哌期间未见有其他重要脏器功能损害。急性排斥反应的发生率 :治疗组 6 % (3/5 0 ) ,对照组 2 9% (18/ 6 2 ) ,P =0 0 0 19。感染的发生率 :治疗组 5 6 % (2 8/ 5 0 )。对照组 5 8% (36 / 6 2 ) ;P =0 82 6。结论赛尼哌在肝移植中应用安全有效 ,有利于肾功能不全的恢复 ,不增加感染的发生率 ,不引起重要脏器功能不全。联合应用赛尼哌 ,可减低钙调神经磷酸酶抑制剂 (calcineurininhibitor,CNI)的血药浓度 ,在术后早期推迟CNI的应用时间 ,同时明显减低急性排斥反应的发生率。     

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.