microRNA-34a的表达对膀胱癌细胞系J82生物学行为的影响

目的:探讨microRNA-34a(miR-34a)的外源性表达对人膀胱癌J82细胞生物学行为的影响。方法:将miR-34a表达质粒或对照质粒转染J82细胞,实时定量逆转录聚合酶链反应(qRT-PCR)检测miR-34a在转染细胞中的表达水平,细胞计数法、流式细胞术、Transwell侵袭实验分别检测外源性miR-34a表达后J82细胞增殖、凋亡、周期和侵袭能力的变化情况。结果:miR-34a表达质粒组与对照组比较,其miR-34a表达诱导性升高(P=0.002 6),细胞增殖受到抑制(P=0.000 1),细胞凋亡率增加(1.237%±0.116%vs 5.497%±0.293%;P<0.000 1),细胞周期阻滞于G0～G1期(54.510%±1.501%vs 62.200%±0.754%;P=0.001 5);细胞侵袭能力降低,(65.01±11.79)vs(34.33±9.71),P=0.025 4。结论:在膀胱癌J82细胞中增加miR-34a的表达,可抑制细胞增殖和侵袭,促进细胞凋亡和周期阻滞,并通过影响上述细胞生物学行为降低肿瘤细胞恶性度,miR-34a在膀胱癌细胞系中发挥潜在的抑癌基因作用。     

miR-34a在膀胱癌中下调MTA2表达的研究

目的 研究微小核糖核酸34a（microRNA-34a,miR-34a）在膀胱癌中的表达及临床意义,确定转移相关基因2（metastasis-associated gene2,MTA2）是否为miR-34a调控的下游靶基因,探讨膀胱癌中miR-34a与MTA2的相互作用机制。方法 选取48对膀胱癌根治术后癌组织及癌旁组织,标本来源于2011年5月至2012年5月我科收治的膀胱癌患者。Real-time PCR检测miR-34a和MTA2在组织中RNA的表达情况;荧光素酶实验鉴定MTA2是否为miR-34a下游靶基因;膀胱癌细胞株T24及UMUC3中转入miR-34a后,琼脂糖凝胶电泳、免疫印迹实验检测MTA2的RNA及蛋白表达。结果 Real-time PCR检测表明,膀胱癌组织中miR-34a呈低表达,并且与肿瘤分期有关（P〈0.01）;MTA2在癌组织中表达明显上调。MiRanda、Mirwalk、Targetscan软件预测miR-34a与MTA2的mRNA有结合位点,荧光素酶实验结果表明MTA2可能是miR-34a的潜在靶基因。转染miR-34a后,分别检测MTA2的蛋白和mRNA表达情况,发现MTA2蛋白受到抑制,mRNA表达不受影响。结论 miR-34a在膀胱癌中可能通过作用于其潜在靶基因MTA2而发挥抑癌基因作用。     

microRNA-497 在肝细胞癌中的表达及意义

目的:探讨microRNA-497(miR-497)在肝细胞癌组织中的表达及其意义.方法:收集40例肝细胞癌及对应癌旁组织标本,用qRT-PCR方法检测标本中miR-497的表达;人肝癌SMMC-7721细胞经miR-497模拟物转染后,用MTT和流式细胞术检测其增殖能力与凋亡水平的变化,并用qRT-PCR和Western blot检测miR-497潜在靶点Bcl-w的mRNA与蛋白的表达.结果:miR-497在肝癌组织中的表达水平明显低于其癌旁组织[(1.181±0.779)vs.(14.599±5.266),P＜0.05];转染miR-497模拟物的SMMC-7721细胞增殖能力明显降低,细胞凋亡增加,Bcl-w的mRNA与蛋白表达均明显降低(与未转染的SMMC-7721细胞比较,均P＜0.05).结论:肝癌组织中miR-497表达下调,该下调可能导致靶基因Bcl-w表达升高,从而促进肿瘤的发生与发展.     

抑癌基因RUNX3在膀胱癌T24细胞株中的表达以及对凋亡的影响

目的 明确RUNX3抑癌基因在正常膀胱组织和膀胱癌T24细胞株的甲基化状态,并将野生型RUNX3基因转染T24细胞,探讨RUNX3基因恢复表达后对膀胱癌细胞凋亡的影响. 方法应用RT-PCR、甲基化特异性PCR和非甲基化PCR检测正常膀胱组织、膀胱癌T24细胞中RUNX3基因的表达以及基因启动子区域CpG岛的甲基化状态.构建真核载体的RUNX3-EGFP-pDest质粒,在LipefectamineTM2000介导下转染膀胱癌T24细胞,转染实验设立3组:空白对照组、空质粒EGFP-pDest转染组以及RUNX3-EGFP-pDest转染组.Western blot检测RUNX3蛋白表达,流式细胞仪检测细胞凋亡情况. 结果正常膀胱组织RT-PCR可检测出1248bp的RUNX3基因条带,而膀胱癌T24细胞中无法检测出RUNX3基因的表达.正常膀胱组织RUNX3基因甲基化PCR检测阴性,非甲基化PCR阳性;T24细胞反之.正常膀胱粘膜组和RUNX3-EGFP-pDest质粒转染组Western blot检测,均表达RUNX3蛋白,而膀胱癌T24细胞未表达RUNX3蛋白.流式细胞仪检测,空白对照组的凋亡率为(3.1±0.46)%,而EGFP-pDest转染组和RUNX3-EGFP-pDest质粒转染组的凋亡率分别为(10.1±1.62)%、(41.20±1.53)%,应用方差分析的LSD法和SNK法进行均数的多重两两比较,RUNX3-EGFP-pDest质粒转染组与EGFP-pDest转染组、空白对照组凋亡率之间的差异均具有显著性,P<0.01.结论 正常膀胱组织RUNX3基因正常表达,未发生启动子区域CpG岛甲基化,而膀胱癌T24细胞可能因RUNX3基因启动子区域CpG岛发生甲基化,致RUNX3基因无法表达.转染野生型RUNX3抑癌基因后促进了膀胱癌T24细胞的凋亡.     

前列腺干细胞抗原在膀胱尿路上皮癌组织中的表达及其临床意义

目的探讨前列腺干细胞抗原（PSCA）在膀胱尿路上皮癌组织中的表达情况,并分析其与膀胱癌临床病理特征及复发的关系。方法选择105例膀胱尿路上皮癌标本,20例癌旁正常膀胱组织标本。癌标本中非肌层浸润性癌74例,肌层浸润性癌31例;G1 26例、G2 54例、G3 25例;单发肿瘤63例,多发肿瘤42例;非肌层浸润性癌中未复发31例,复发43例。采用SP免疫组织化学方法检测膀胱癌和癌旁正常组织中PSCA蛋白的表达,并结合临床病理资料进行分析。结果正常膀胱组织中无PSCA蛋白表达,癌组织中随病理分级和分期增加,PSCA相对表达量逐渐增高。G1、G2、G3 膀胱癌PSCA蛋白表达阳性率分别为23．1％、46．3％,76．0％,差异均有统计学意义（P〈0．001）。非肌层浸润性肿瘤和肌层浸润性肿瘤中PSCA蛋白表达阳性率为47.3％和71．0％,差异有统计学意义（P=0．004）。随访3～54个月,非肌层浸润性膀胱癌中,复发组与未复发组中PSCA蛋白高表达阳性率为65．1％和32.3％,差异有统计学意义（P〈0．001）。结论PSCA蛋白高表达与膀胱尿路上皮癌的恶性程度及预后相关,检测PSCA有助于膀胱癌的诊断及评估预后。     

微小RNA-146a在骨肉瘤中的表达及意义

目的 探讨微小RNA(miRNA,miR)-146a在骨肉瘤中表达的意义和miRNA-146a对骨肉瘤的作用机制.方法 实时定量聚合酶链反应(Real-time PCR)检测骨肉瘤标本和癌旁组织中miRNA-146a表达量,并采用Cox回归模型分析其与患者生存期的相关性.质粒转染miRNA-146a进入骨肉瘤细胞TE85中,检测转染后细胞活性、细胞凋亡和细胞中YY1、Fas蛋白的表达.结果 癌旁组织和骨肉瘤组织中miRNA-146a的表达量分别为1.213±0.525和0.734±0.263,差异有统计学意义(P＜0.05).miRNA-146a的表达量与患者的生存时间呈正相关(P＜0.05).转染miRNA-146a24 h后,50、100 nmol/L组人骨肉瘤细胞活性明显降低至(65.161±5.528)％和(40.385±8.442)％(P＜0.05),细胞凋亡率分别明显升高至(38.671±12.415)％和(59.513±9.058)％ (P＜0.05),细胞中YY1蛋白表达量明显降低(分别为0.472±0.014和0.272±0.005,P＜0.05),而Fas蛋白表达量明显升高(0.292±0.010、0.584±0.006,P＜0.05).转染miRNA-146a 48 h后,与对照组比较,50、100 nmol/L组人骨肉瘤细胞活性、凋亡率、YY1表达量和Fas蛋白表达量变化与转染24 h的变化相似.结论 miRNA-146a对骨肉瘤的作用是通过下调YY1的表达,而上调Fas蛋白的表达,抑制骨肉瘤细胞的增殖同时促进骨肉瘤细胞的凋亡.     

miR-184靶向AGO2调控AKT/mTOR信号通路对膀胱癌细胞增殖、迁移及侵袭能力的影响

目的 研究miR-184在膀胱癌发生、发展过程中的作用及其相关机制。方法 收集2015年1月至2017年1月南阳市中心医院87例膀胱癌患者的手术切除标本,采用qRT-PCR检测膀胱癌及癌旁组织中miR-184的表达;通过生物信息学方法预测miR-184的靶基因并采用双荧光素酶实验及免疫荧光进行验证。在人膀胱癌细胞系T24中转染miR-184过表达质粒,MTT、Transwell侵袭和划痕实验检测细胞增殖、侵袭和迁移能力,Western blot检测AKT/mTOR通路蛋白的表达。结果 miR-184在膀胱癌组织中的相对表达水平1.238±0.026明显低于癌旁组织2.601±0.054,差异有统计学意义(t=22.57,P0.01);且其表达水平与膀胱癌患者的TNM分期(t=-5.61,P0.001)、淋巴结转移(t=-2.35,P=0.011)及组织学分级存在明显相关(t=2.171,P=0.033)。生物信息学预测及双荧光素酶报告基因实验证实miR-184能直接靶向结合AGO2基因3′-UTR。体外实验结果表明,转染miR-184模拟物后,膀胱癌细胞T24中AGO2mRNA和蛋白的表达水平明显下调,细胞增殖、迁移及侵袭能力降低,p-mTOR、p-AKT蛋白表达降低(P0.05)。结论 miR-184在膀胱癌组织中低表达,上调miR-184表达可抑制细胞的增殖、侵袭和迁移能力,其作用机制可能与AKT/mTOR信号通路的调节有关。     

RNA干扰对膀胱癌T24细胞血管内皮生长因子C表达的影响

目的 观察RNA干扰(RNAi)抑制膀胱癌T24细胞中血管内皮生长因子C(VEGF-C)表达和提高化疗敏感性.方法 根据转染效率最高时pEGFPN1质粒与脂质体的比例,转染T24细胞,实验分为3组,逆转录-聚合酶链反应(RT-PCR)检测VEGF-C mRNA的表达,流式细胞仪分析细胞凋亡率.结果 转染后24 h,即有mRNA表达水平的下降,Quantity one半定量:24 h 0.57±0.17,48 h 0.42±0.11,72 h0.33±0.09.VEGF-C抑制后,吉西他滨诱导的凋亡率明显升高,转染组为(41.38±1.54)%,明显高于未转染组(22.87±1.40)%与脂质体组(23.47±1.58)%(P<0.05).结论 RNAi可高效稳定抑制膀胱癌T24细胞中VEGF-C的表达,明显提高吉西他滨诱导膀胱癌T24细胞凋亡的药物敏感性.     

miR-34a靶向STAT1基因调控牙周膜细胞增殖及凋亡的分子机制

目的:探讨miR-34a靶向STAT1基因调控牙周膜细胞增殖及凋亡的分子机制。方法:将PDLCs细胞分成Pm、Py、Pz三组,Pz组(PDLCs细胞不做任何处理),Pm组(转染miR-34a模拟物)、Py组(转染miR-34a抑制物),RT-PCR检测STAT1、miR-34a水平,Westernblot法检测STAT1蛋白表达,流式细胞仪、MTT法分别检测PDLCs细胞凋亡、增殖情况。结果:RTPCR检测STAT1、miR-34a水平结果显示,与Pz组对比,Py组STAT1、miR-34a水平有显著下降,Pm组STAT1、miR-34a水平最高,Pz组STAT1、miR-34a水平其次,Py组STAT1、miR-34a水平最低(均P0.05)。Westernblot法检测STAT1蛋白发现,与Pz组对比,Py组STAT1蛋白较Pm组有显著下降,Pm组STAT1蛋白表达最高,Pz组蛋白表达其次,Py组STAT1蛋白表达最低(均P0.05)。流式细胞术检测发现,与Pz组对比,Pm组PDLCs细胞凋亡明显增加,与Pm组对比,Py组细胞凋亡明显降低(均P0.05),Pm组细胞凋亡呈三组最高,Pz组其次,Py组最低。MTT检测结果显示:Pz组PDLCs细胞在24h、48h、72h时均缓慢增长,Py组PDLCs细胞24h、48h增殖变化较平稳,72h时增殖速度明显加快,Pm组受miR-34a模拟物影响,PDLCs细胞数量增殖缓慢(均P0.05)。结论:miR-34a低表达能够抑制PDLCs细胞凋亡,促进其生长,这一作用机制可能与降低STAT1蛋白表达有关。     

膀胱癌中DNA甲基转移酶1表达的实时定量检测

目的 探讨DNA甲基转移酶1(DNMTl)mRNA在膀胱移行细胞癌中的表达水平及其临床意义.方法 膀胱癌手术标本35例.男29例,女6例.年龄24～88岁,平均68岁.初发28例,复发7例.病理分级:G1 12例,G2 14例,G3 9例.临床分期非浸润性膀胱癌(Tis～T1)11例,浸润性膀胱癌(T2～T4)24例.以SYBR green为信号标记,应用实时荧光定量PCR法检测35例膀胱癌组织及10例正常膀胱黏膜中DNMT1 mRNA的表达.结果膀胱癌中DNMT1 mRNA的表达(3.25±0.74)明显高于正常膀胱黏膜(1.53±0.44,P＜0.001).非浸润性膀胱癌标本DNMT1 mRNA表达值为3.14±0.67、浸润性膀胱癌为3.31±0.84(P＞0.05).G1～G3膀胱癌组织DNMT1 mRNA表达值分别为3.13±0.59、3.25±0.64、3.43±0.55,各组间比较差异无统计学意义(P＞0.05).＞40岁患者表达值(3.34±0.50)高于≤40岁者(3.01±0.27),差异有统计学意义(P＜0.05).男性患者表达值(3.31±0.42)高于女性患者(3.01±0.20),差异有统计学意义(P＜0.05).复发者表达值(3.45±0.33)高于初发者(3.21±0.63),但差异无统计学意义(P＞0.05).结论 DNMT1过表达与膀胱癌关系密切,可能足抑癌基因启动子区CpG岛DNA甲基化修饰频率大大提高的原因,导致基因失活,从而参与膀胱癌的发生发展.     

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.