增殖性腺病毒CNHK600-p53可增强肝癌细胞株SMMC7721对化疗药物的敏感性

目的构建携带p53基因新型增殖性腺病毒CNHK600-p53,研究其是否增加肝癌细胞株对化疗药物的敏感性。方法采用四甲基偶氮唑盐(m ethylth iazolyl tetrazolium assay,MTT),观察化疗药物5-氟尿嘧啶(F luorourac il,5-Fu)、丝裂霉素(M itomyc in,MMC)和表阿霉素(Ep irub ic in,EPI)组与携带p53基因的重组腺病毒CNHK600-p53联合上述化疗药物组对肝癌细胞株SMMC7721的杀伤效应,同时观察其是否优于Ad-p53。结果单用CNHK600-p53或Ad-p53对肝癌细胞SMMC7721的杀伤效果无明显差别;肝癌细胞株SMMC7721在5-Fu浓度为100 ug/m l时细胞抑制率为58%,MMC浓度为2.5 ug/m l时细胞抑制率为50%,EPI浓度为1.25ug/m l时细胞抑制率为57%,但转入CNHK600-p53(MO I=10)后再使用上述浓度的化疗药物,细胞抑制率分别为76%、60%和62%。结论单用CNHK600-p53或Ad-p53对肝癌细胞SMMC7721的杀伤效果无明显差别,携带p53基因的CNHK600-p53能提高肝癌细胞株SMMC7721对化疗药物的敏感性,CNHK600-p53联合化疗药物治疗可望开辟克服肝癌耐药的新途径。     

新型增殖性腺病毒的构建及对肝癌细胞的抑制

目的 构建携带p53基因新型增殖性腺病毒CNHK600-p53,研究其对肝癌细胞株抑制效应是否优于Ad-p53.方法 PCR扩增p53基因,利用酶切连接方法 将其插入CNHK600载体,PCR鉴定.经293细胞包装成病毒,抽提病毒DNA,PCR鉴定.氯化铯密度梯度离心法纯化病毒,TCID50 方法 测病毒滴度.病毒增殖实验检测病毒在不同细胞增殖能力.四甲基偶氮唑盐(methyl-thiazolyl tetrazolium assay,MTT)法观察CNHK600-p53、Ad-p53两种病毒分别对肝癌细胞株的抑制率.结果 成功构建新型增殖性腺病毒载体CNHK600-p53;293细胞包装成病毒,PCR方法 鉴定无野生型病毒存在;病毒滴度为1.99×10~（10）pfu/ml;CNHK600-p53在肝癌细胞HepG2、SMMC-7721内复制能力明显高于正常肝细胞HEL-1和L02.对6种肝癌细胞(PLC/PRF5、SMMC7721、HepaG2、BEL-7402、BEL-7404、QGY-7703)而言,随着MOI值的不断增高.其对肝癌细胞的抑制作用也不断增强;在相同MOI情况下,CNHK600-p53组较Ad-p53组的细胞抑制率高(P＜0.05).当细胞抑制率达到80%以上时.两组之间差异无统计学意义(P＞0.05).结论 利用新型增殖性腺病毒CNHK600一p53较 Ad-p53能更有效的抑制肝癌细胞,可能成为肝癌的基因治疗更有效的一种基因治疗手段.     

野生型p53基因对不同内源性p53状态的肝癌细胞株生长的影响

目的探讨外源性野生型p53(wild-type p53,WT-p53)基因对具有不同内源性p53功能状态肝癌细胞生长的影响.方法通过表达WT-p53的重组腺病毒载体(Ad-p53),将p53基因导入具有不同内源性p53功能状态的肝癌细胞株Bel-7402、QGY-7701和PLC/PRF/5中,用MTT法检测Ad-p53对各细胞株生长的影响,流式细胞仪分析各组细胞中DNA含量及凋亡的比例.结果当取40、200、800 MOI值的表达p53的腺病毒分别转染PLC/PRF/5、Bel-7402和QGY-7701细胞时,72 h后行MTT检测,OD值分别为在 PLC/PRF/5细胞,空载体(Ad-LacZ)组0.98±0.16,Ad-p53组0.02±0.00(P＜0.01);在Bel-7402细胞Ad-LacZ组1.04±0.23,Ad-p53组0.10±0.02(P＜0.01);而在QGY-7701细胞Ad-LacZ组1.88±0.24,Ad-p53组1.86±0.19(P>0.05).细胞周期分析显示,在PLC/PRF/5,表现为既诱导细胞凋亡,又诱导细胞周期阻滞.在Bel-7402,表现为诱导细胞周期阻滞.结论外源性p53对肝癌细胞生长的抑制可能与内源性p53功能状态无关.     

基因-病毒治疗系统CNHK500-p53的构建和体外初步研究

目的构建一种新的基因-病毒治疗系统。方法通过基因操作技术将目的基因表达盒mCMV启动子 p53基因 SV40polyA插入腺病毒E1A基因受端粒酶逆转录酶(hTERT)启动子调控、E1B基因受缺氧反应元件(HRE)启动子调控的增殖病毒载体质粒pSG500的E1A下游,得到腺病毒质粒pSG500-p53;通过pSG500-p53与5型腺病毒右臂的质粒pBHGE3在293细胞中同源重组得到重组病毒CNHK500-p53;利用Westernblot和ELISA法检测病毒E1A、E1B基因和p53抑癌基因的表达;TCID50方法测定病毒滴度;通过增殖实验观察重组病毒的选择性增殖能力;应用细胞病理效应(CPE)实验检测病毒抗肿瘤作用。结果CNHK500-p53的病毒滴度为2×1010pfu/ml,增殖实验证实CNHK500-p53可以选择性地在端粒酶阳性和缺氧微环境的肝癌细胞中增殖,CNHK500-p53所携带的p53基因在肝癌细胞株中的表达量388±34.6μg/L明显高于非增殖型腺病毒载体Ad-p53的76.3±13.17μg/L(P<0.005),并显示了较强的抗肿瘤效应。结论CNHK500-p53是一种具备治疗肝癌潜力的新型基因-病毒治疗系统。     

肝细胞生长因子受体反义寡核苷酸影响胶质瘤细胞对丝裂霉素C敏感性的研究

目的探讨肝细胞生长因子受体(c-Met)反义寡核苷酸(ASODN)增强胶质瘤细胞系 U251细胞对丝裂霉素C(MMC)敏感性的作用。方法用5 μmol／L c-Met ASODN封闭U251细胞 c-Met mRNA,将50μg/L的MMC与其共培养,采用逆转录-聚合酶链反应(RT-PCR)技术检测c- Met mRNA表达,噻唑蓝(MTT)试验检测U251细胞的生长情况,免疫组织化学法检测细胞PCNA 蛋白的表达,体外检测细胞黏附率。以无义寡核苷酸处理及未处理U251细胞为对照。结果经 c-Met ASODN处理的U251细胞 ,c-Met mRNA的表达(吸光度值为62±21)明显低于经无义寡核苷酸处理U251细胞(吸光度值为150±25,P<0．05);对MMC的敏感性,细胞生长抑制率、细胞黏附率及PCNA指数分别为(53．84±12．21)％、(14．61±3．82)％和(0．35±0．02)％,明显高于相应的无义[(9．86±3．42)％、(24．84±5．90)％和(0．55±0．04)％,P<0．05]。结论 c-Met ASODN能增强胶质瘤细胞系U251细胞对MMC的敏感性,其分子机制可能与c-Met反义寡核苷酸下调了c- Met基因和PCNA蛋白的表达有关。     

携带小鼠白介素12基因的增殖型腺病毒对胃癌细胞株化疗敏感性影响的研究

目的研究携带白介素12(mIL-12)基因的增殖型腺病毒CNHK200-mIL-12对胃癌细胞株化疗敏感性的影响。方法扩增增殖型腺病毒Onyx-015及携带小鼠mIL-12基因的增殖型腺病毒CNHK200-mIL-12,利用MTT法测定同一病毒滴度下联合应用不同浓度化疗药物及同一化疗药物浓度下联合应用不同滴度病毒对胃癌细胞株杀伤作用,并观察增殖型腺病毒联合化疗药物对裸鼠腹腔种植瘤的抑制作用。结果当不同感染复数(MOI)=0.5时,增殖型病毒Onyx-015、CNHK200-mIL-12对胃癌细胞SGC-7901无明显的杀伤作用。加入化疗药物阿霉素(ADM)、氟尿嘧啶(5-Fu)和卡铂(CAP)后,两者对SGC-7901的杀伤率随着药物浓度增加都有不同程度的升高,与单纯使用化疗药物组比较,差异有统计学意义(P<0.05)。浓度为10μg/ml的5-Fu对SGC-7901的杀伤作用不明显,单用增殖型腺病毒对SGC-7901的杀伤作用也较弱,两者联合应用杀伤活性明显提高,与未加5-Fu组比较,差异有统计学意义(P<0.05)。动物试验证明:经Onyx-015联合5-Fu治疗后,裸鼠腹腔内肿瘤形成率为1/6,而CNHK200-mIL-12联合5-Fu组未见腹腔内肿瘤生长,与单用增殖型腺病毒或单用化疗者比较,差异有统计学意义(P<0.05)。结论携带mIL-12基因的增殖型腺病毒能够提高胃癌细胞株对化疗药物的敏感性,在杀伤胃癌细胞株的作用中     

导入野生型p53基因对人胶质瘤细胞生长及化疗敏感性的影响

目的 研究野生型p53基因对人胶质瘤细胞生长及化疗敏感性的影响。方法 将载有野生型p53基因的表达质粒PC53-SN3导入U251细胞。通过逆转录-聚合酶链反应(RT-PCR)检测p53基因在转染细胞中的表达,用四甲基偶氮唑盐微量酶反应比色法(MTT法)和流式细胞仪检测p53基因对U251细胞生长抑制及凋亡的影响以及它与顺铂联合作用后的效果。结果 通过RT-PCR证实了野生型p53基因在U251细胞中的表达。MTT检测发现p53基因对U251细胞的生长有明显的抑制作用,抑制率为(79.60±5.69)％。顺铂对 U251细胞的抑制作用随着顺铂浓度的增加(1、2、4、8 mg/L)而增强,抑制率分别为(19.40±6.69)％、(24.41±2.68)％、(51.84±13.38)％、(66.22±5.02)％,但不如 p53基因的抑制作用强。当野生型 p53基因与顺铂联合作用于 U251细胞时,抑制率明显增加,分别为(91.64±1.00)％、(94.98±1.67)％、(95.32±2.01)％、(95.65±1.00)％。p53基因转染所产生的 U251细胞凋亡率为 17.38％。顺铂引起的细胞凋亡率随着顺铂浓度的增加(1、2、4、8mg/L)而增加,分别为5.71％、5.93％、6.27％、6.81％。当p53基因与不同浓度的顺铂(1、2、4、8mg/L)联合作用于U251细胞时,凋亡率也明显增加,分别为23.50％、23.54％、23.89％、28.88％。结论 野生型p53基因与     

结直肠癌术后顺铂和5-氟尿嘧啶化疗及枢复宁对胃肠动力的影响

14例结直肠癌术后化疗病人进行胃肠动力采用PC Polygraf HR台式高分辨八导消化道动力监测系统进行测压；第一天为对照期，第二天为化疗期，方案为顺铂40mg如和5-FU 500mg；第三天为枢复宁期，继续化疗药物，化疗前5min静推枢复宁8mg。结果 显示对照期MMC个数为9．14±2．54个从，化疗期增至13．14±3．96个从(P<0.01)。枢复宁期MMC数为13．07±360个／人。MMC周期对照期为170±50min．化疗期期缩短至122±47min(P<0．05)。枢复宁期为124±65min。MMC移行速度对照期为0．114±0.028cm／sec，化疗期加快至0.161±0．049cm／sec，枢复宁期MMC的移行速度平均为0．13±0.017cm／sec。MMCⅢ相收缩波数对照期为453±109个/人。化疗期增加至664±196个从(P<0.01)。枢复宁期MMCⅢ相收缩渡数为646±209个／人。MMCⅢ相收缩波幅植对照期为409±0．99kPa，化疗期为4．13±1．13kPa(P<0．05)。枢复宁期为3．92±1．19kPa。应用化疗药物后14例病人中9例发生呕吐，发生呕吐的时间为280±28min。应用枢复宁后，无病人再发生呕吐(P<0.05)，但不增强胃肠道平滑肌的收缩强度。枢复宁可抑制化疗药物引起的呕吐，化疗药物引起胃肠动力加快和呕吐属于两不同的机制，两间无因果关系。     

腺病毒介导p53基因对胰腺癌细胞抑制作用的体外实验研究

目的 探讨腺病毒介导p53基因(adenovirus-mediated p53 gene,Ad-p53)对人胰腺癌细胞株PANC-1的生长抑制作用.方法 以Western Blot方法 检测加入Ad-p53后PANC-1细胞在48h 、72h p53表达情况以及未处理组细胞48h 、72h p53的表达.采用四甲基偶氮唑盐(MTT)比色实验检测不同MOI值的Ad-p53感染后,PANC-1细胞的生长情况并绘制生长曲线,用PI、annexin V-FITC双重染色并用流式细胞技术检测受感染细胞的凋亡比例.结果 Western Blot结果 显示,处理组细胞内48h 、72h p53蛋白表达明显高于相同时间点对照组细胞;MTT结果 显示不同MOI值细胞生长抑制情况不同,MOI值越高,对细胞生长的抑制程度也越高;流式检测细胞在MOI值为150时,0h、48h、72h凋亡比例分别为(7.5±0.8)%、(22.5±2.3)%和(34.4±2.7)%,对照组细胞为(5.8±0.4)%、(8.3±1.7)%和(9.7±2.1)%.结论 Ad-p53能有效感染胰腺癌细胞,导致胰腺癌细胞凋亡.     

细胞周期蛋白D1和P21WAF1在胃癌中的表达及其与化疗药物敏感性的关系

目的检测细胞周期蛋白（cyclin）D1、P21WAF1在胃癌组织中的表达,并探讨其与化疗药物敏感性的关系。方法采用MTT比色法观察80例胃癌原代培养细胞在体外对化疗药物羟基喜树碱（HCPT）、顺铂（DDP）、阿霉素（ADM）、氟尿嘧啶（5-Fu）及丝裂霉素（MMC）的敏感性;免疫组织化学染色检测cyclin D1和P21WAF1蛋白在胃癌组织中的表达情况。结果胃癌细胞对不同化疗药物敏感性不同：5-FU、MMC和DDP对胃癌细胞的抑制率显著高于ADM和HCPT（P〈0．05）。胃癌组织中cvclin D1和P21WAF1蛋白的阳性率分别为70．0％和47．5％。cyclin D1阳性表达者对5-Fu和HCPT的敏感性显著高于阴性表达者（P〈0．05）,而P21WAF1阴性表达者对MMC、5-FU和DDP的敏感性显著高于阳性表达者（P〈0．05）。结论cyclin D1和P21WAF1蛋白与胃癌对化疗药物敏感性有关．检测其表达对于化疗药物的选择具有一定的参考价值。     

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.