1-甲基色氨酸对胰腺癌荷瘤鼠中调节性T细胞数量变化的影响

目的 观察1-甲基色氨酸(1-MT)对胰腺癌荷瘤鼠中调节性T细胞(Treg)数量变化的影响,比较树突状细胞(DC)疫苗与1-MT联合应用前后抗肿瘤作用的强弱.方法 建立小鼠胰腺癌模型;利用流式细胞术检测荷瘤鼠应用1-MT前后肿瘤组织周围引流淋巴结(TDLNs)及脾脏中CD4~+ CD25~+T细胞占CD4~+T比例;荧光定量聚合酶链反应(PCR)测量Foxp3在TDLNs及脾脏mRNA水平;利用肿瘤细胞裂解物冲击DC制备DC疫苗,并根据是否与1-MT联合应用分组(各组均为n=8);观测各组肿瘤体积的差异.结果 应用1-MT后,荷瘤鼠CD4~+ CD25~+ T细胞占CD~+T细胞的比例明显低于未应用组(TDLNs)分别为(16.01±2.21)%和(25.00±2.16)%(P<0.05);脾脏分别为(13.11±1.93)%和(22.14±2.33)%(P<0.05,P<0.01);应用1-MT组Foxp3 mRNA表达水平显著低于未应用组,应用1-MT组相对表达值:TDLNs0.947±0.216、脾细胞1.198±0.347,而未应用组分别为:1.927±0.256、1.798±0.237(P<0.05);1-MT+DC疫苗组肿瘤生长显著受到抑制,第36天肿瘤体积为(789.0±111.0)mm~3;显著小于DC疫苗组、1-MT组及对照组,肿瘤体积分别为:(1768.0±251.3)、(1854.0±192.1)、(1899.0±201.2)mm~3(P<0.01).结论 1-MT可以有效抑制胰腺癌荷瘤鼠癌组织周围引流淋巴结及脾脏CD4~+ CD25~+ Treg细胞的数量增加,从而增强DC疫苗抗肿瘤作用.     

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.     

树突状细胞肿瘤疫苗诱导抗胃癌作用的实验研究

目的探讨树突状细胞(dendriticcells,DCs)肿瘤疫苗诱导的抗胃癌效应对荷瘤裸小鼠的作用。方法使用胃癌细胞冻融抗原,体外致敏从小鼠骨髓诱导分化来源的DCs成为肿瘤疫苗,用其来刺激脾脏淋巴细胞,得到肿瘤抗原特异的细胞毒性T淋巴细胞(CTL),观察其对荷瘤裸小鼠肿瘤生长的影响以及早期凋亡诱导作用。结果经重组小鼠粒细胞巨噬细胞集落刺激因子(rmGM-CSF)和重组小鼠白细胞介素4(rmIL-4)体外诱导小鼠骨髓细胞,得到大量形态典型、具备强烈刺激增殖能力、高表达CD1a、CD11c、CD40和CD80的DCs。肿瘤抗原致敏DCs刺激脾脏淋巴细胞成为CTL后,可显著抑制裸小鼠皮下移植瘤生长并致瘤细胞早期凋亡增加。结论DCs肿瘤疫苗可通过CTL的作用,抑制荷瘤裸小鼠的胃癌细胞生长及促进胃癌细胞早期凋亡。     

CytoMPS原位疫苗治疗肝癌的抗瘤作用及其免疫效应

目的制作成细胞因子缓释微粒原位瘤苗(CytoMPS-ISV),观测CytoMPS-ISV抗瘤作用及其免疫效应。方法 C57BL/6J小鼠皮下移植性肝癌模型瘤内注射CytoMPS3次制作CytoMPS-ISV,观察其抗肿瘤作用及小鼠生存率;流式细胞仪检测小鼠外周血淋巴细胞变化,免疫组化法检测肿瘤组织的CD4+、CD8+和NK1.1+细胞浸润情况,体外检测小鼠脾CTL和NK细胞的杀瘤活性,检测疫苗诱导脾CTL的抗体阻断作用。结果与PBS注射组和对照组相比,瘤内注射CytoMPS后肿瘤生长受到显著抑制(P0.01)。瘤内注射CytoMPS组血液中及局部浸润的CD4+、CD8+和NK细胞明显高于PBS组和对照组(P0.05);淋巴细胞杀伤试验结果显示瘤内注射CytoMPS组小鼠的脾CTL对靶细胞的杀伤率明显高于PBS组(P0.01)和对照组(P0.05);抗体阻断作用试验显示接种疫苗的小鼠脾CTL的杀瘤活性可被抗CD8+、抗MHC-I单克隆抗体所阻断,但不被抗CD4+、抗MHC-II单克隆抗体所阻断。结论 CytoMPS-ISV可以显著抑制肿瘤生长,能明显增强机体的抗肿瘤免疫作用,其诱导的CTL杀瘤特性是由MHC-I限制的CD8+T细胞所介导。     

转染肿瘤mRNA的树突状细胞疫苗诱导抗肝癌免疫研究

目的探讨转染原发性肝癌(HCC)mRNA的树突状细胞(DC)能否诱导抗肿瘤特异性细胞毒性T淋巴细胞(CTL)。方法采用HCC患者外周血单核细胞(PBMC)体外刺激分化为DC细胞；从人肝癌HepG-2细胞和3例HCC患者的肝癌组织中体外扩增mRNA。以mRNA转染DC细胞，并与PBMC混合培养诱导扩增CTL。流式细胞计数仪检测培养细胞中CD3^ 、CD4^ 、CD8^ 细胞的比例。^51Cr释放法测定CTL的杀瘤活性。结果经扩增人肝癌HepG-2mRNA和2例AFP( )患者的AFP( )HCCmRNA诱导3周后，CD3^ 、CD8^ 细胞占淋巴细胞总数由诱导前的27．8％、26．5％、29．6％升高至89．3％、73．6％、86．8％；而经扩增AFP(-)HCCmRNA诱导3周后，CD3^ 、CD8^ 细胞占淋巴细胞总数由诱导前的25．4％升高至53．6％。转染HepG-2细胞和AFP( )的患者HCCmRNA的DC诱导的CTL对HepG-2细胞杀瘤活性明显高于AFP(-)的患者，其杀瘤特性由MHC-I限制的CD8^ T细胞所介导。结论HCCmRNA体外转染DC能诱导肿瘤特异性CTL，可为肝癌的免疫治疗提供新的有效手段。     

微波消融灭瘤联合瘤内接种树突状细胞诱导特异性抗肝癌免疫

目的 探讨微波消融(MWA)灭瘤联合瘤内接种树突状细胞(DCs)诱导特异性抗肝癌免疫的效能.方法 采用GM-CSF联合IL-4体外培养C57BL/6小鼠骨髓来源的DCs,于第6天收集使用.建立C57BL/6小鼠皮下Hepa1-6肝癌模型,随机分为对照组、瘤内接种DCs组(DC组)、肿瘤微波消融组(MWA组)及肿瘤微波消融+瘤内接种DCs组(MWA+DC组).免疫组织化学法检测肿瘤组织内CD4+和CD8+T细胞的浸润,MTT法检测小鼠脾脏细胞对Hepa1-6的特异性杀伤活性,观测各组小鼠肿瘤生长情况.结果 免疫组织化学法检测显示MWA+DC组肿瘤组织内有大量的CD4+和CD8+T淋巴细胞浸润,显著高于其它组(P<0.05).MwA+DC组脾细胞对Hepa1-6细胞有特异性杀伤效能,在E/T=40和100时,MWA+DC组脾细胞对Hepa1-6细胞的特异性杀伤力显著高于对照组、DC组及MWA组(P<0.05).MWA+DC组小鼠肿瘤完全消退率显著高于其它各组(P<0.05).结论 MWA联合瘤内接种DCs可有效诱导机体产生特异性抗肝癌免疫,是预防MwA治疗后肝瘤复发的一种有效方法 .     

癌细胞裂解物修饰的DC疫苗对胰腺癌荷瘤小鼠的免疫治疗作用

目的　观察经胰腺癌细胞裂解物修饰的DC疫苗对胰腺癌荷瘤小鼠的免疫治疗作用。方法　通过胰腺癌细胞裂解物修饰小鼠DC制成DC疫苗 ,研究其对小鼠抗胰腺癌的免疫保护作用 ,并评估了其对胰腺癌荷瘤小鼠的免疫治疗效果。结果　DC疫苗组的小鼠接种胰腺癌细胞 2 5d后未见移植肿瘤形成 ,其余各组在 3～ 9d后可见有移植肿瘤的生长。DC疫苗组的CTL对胰腺癌细胞有明显的细胞毒作用 ,但其余各组的CTL则缺乏明显的细胞毒作用。DC疫苗组小鼠的生存期 (5 6± 9)d比其余各组明显延长 ,且肿瘤重量 (1 4± 0 8)g明显低于其余各组 (P <0 0 1,P <0 0 5 )。结论　癌细胞裂解物致敏的DC可诱导荷瘤小鼠产生高效的抗胰腺癌免疫应答反应。     

MAGE-1抗原肽致敏DC活化淋巴细胞对裸鼠肝癌移植瘤的免疫防护作用

目的　观察黑色素瘤 1基因 (MAGE 1)抗原肽致敏树突状细胞 (DC)所活化的淋巴细胞(CTL)对人肝癌HCC移植瘤的抑制和消退作用 ,评估临床治疗HCC的可行性和有效性。　方法BEL 74 0 2HCC细胞于 30只裸鼠背部皮下接种 ,建立裸鼠HCC移植瘤模型 ,其中 2 2只成瘤 ;用MAGE 1九肽致敏DC所活化的淋巴细胞 (1× 10 6)注入肿瘤部位皮下 (治疗组A ,n =5 ) ,其余 17只随机分成 5组 (B、C、D、E、F) ,用其他不同性质的细胞治疗 ,观察各组肿瘤生长情况并进行病理学分析和统计学处理 ,阐明特异性CTL对肿瘤的作用机制。　结果　 (1)A组HCC移植瘤均停止生长并趋于缩小 ,荷瘤裸鼠观察期内无死亡 ;而其他 5组肿瘤均快速生长 ,大部分荷瘤裸鼠 2周内死亡。MAGE 1九肽致敏DC所活化淋巴细胞能显著抑制HCC移植瘤生长 ,促使肿瘤消退 (P <0 0 1)。 (2 )A组移植肿瘤广泛坏死 ,肿瘤细胞广泛凋亡。　结论　MAGE 1九肽致敏DC有抑制HCC生长 ,促进HCC消退 ,防止肿瘤转移、复发的作用。肿瘤细胞凋亡增强是DC肿瘤免疫的可能机制。MAGE 1九肽联合DC可作为治疗HCC的新型疫苗。     

脂质体介导IFN-γ基因治疗荷大肠癌小鼠的实验研究

目的探讨利用γ 干扰素 (interferon γ ,IFN γ)基因对大肠癌的治疗作用及其作用机制。方法构建携带IFN γ基因的真核表达质粒pcDNA3 IFN γ ,以脂质体作载体 ,对荷大肠癌小鼠行瘤体内注射IFN γ基因 ,检测经基因治疗后小鼠体内IFN γ基因的表达、脾脏的细胞毒性T淋巴细胞 (cyto toxicTlymphoctye,CTL)活性、肿瘤的大小、肿瘤局部的淋巴细胞浸润情况及荷瘤小鼠的生存期。结果经IFN γ基因治疗后 ,治疗组小鼠血清中IFN γ表达量和脾脏的CTL活性明显增强 (P <0 0 1) ,肿瘤局部淋巴细胞浸润明显 ,肿瘤生长受到抑制 ,荷瘤小鼠的存活期明显延长。结论利用IFN γ基因治疗大肠癌具有明显的疗效。     

吗替麦考酚酯抑制小鼠TH17细胞的分化和增殖

目的 通过观察吗替麦考酚酯(MMF)对小鼠辅助性T淋巴细胞17(TH 17细胞)分化和增殖的影响,探讨MMF的免疫抑制作用及其机制.方法 采用随机数字表法将小鼠分为MMF组与对照组,每组8只.MMF组小鼠每天给予MMF 40 mg·kg-1·d-1灌胃,对照组小鼠每天给予等体积生理盐水灌胃.3周后取小鼠外周血和脾脏,采用流式细胞术检测小鼠外周血和脾细胞中TH17细胞和CD4+CD25+调节性T淋巴细胞(Treg细胞)的比例,并计算出TH 17细胞与Treg细胞的比值;采用酶联免疫吸附试验法分别检测两组小鼠血清中白细胞介素(IL)-17和IL-23的浓度.结果 MMF组外周血和脾细胞中TH17细胞比例分别为(1.95±0.08)％和(2.42±0.06)％,对照组分别为(3.19±0.07)％和(4.21±0.25)％,两组比较,差异均有统计学意义(P＜0.05).MMF组外周血和脾细胞中TH 17细胞与Treg细胞的比值均显著低于对照组(P＜0.05).MMF组小鼠血清IL-17水平明显低于对照组(P＜0.05),而血清IL-23水平高于对照组(P＜0.05).结论 MMF能够明显抑制小鼠体内TH17细胞的分化与增殖,降低TH 17细胞与Treg细胞的比值,减少IL-17的分泌,有利于诱导免疫耐受.     

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.