miR-139-5p对人肝癌细胞增殖和侵袭的影响

目的 探讨微小RNA(miRNA)-139-5p在肝癌组织中的表达及其对人肝癌细胞增殖、侵袭的影响和潜在的分子机制。方法 采用生物信息学方法,从GEO数据库中下载GSE36915数据集,进行差异miRNA分析,结合TCGA-LICH数据集中的生存数据,筛选与预后显著相关的miRNA。采用实时荧光定量PCR(qRT-PCR)检测miR-139-5p在肝癌及其癌旁组织中的表达。利用CCK-8实验、Transwell实验观察miR-139-5p对人肝癌细胞SK-Hep-1和SMMC-7721的表型变化。采用高通量测序检测过表达miR-139-5p的SK-Hep-1细胞中基因表达的变化,确定miR-139-5p调控的潜在的信号通路和靶基因,并采用免疫印迹实验和报告基因实验进行验证。结果 通过对GSE36915数据集进行分析,共鉴定到50个显著差异表达的miRNA。结合TCGA-LICH数据集中的生存数据,发现在差异最显著的20个miRNA中,miR-15b-3p、miR-1180-3p、miR-139-5p、miR-139-3p与预后显著相关,最终确定miR-139-5p为进一步研究对象。mi...     

miR-18a-3p在肝癌中的表达及其调控ADCY1表达对肝癌细胞侵袭及增殖的影响

背景与目的 研究表明多种microRNA（miRNA）可能在肝癌的发生发展中发挥重要作用,其作用机制仍值得进一步研究和探讨。因此,本研究从已报道的肝癌差异表达miRNA中进一步筛选关键miRNA,并验证和探讨其作用机制。方法 从已发表的研究中筛选出肝癌组织及肝癌患者血清/血浆中与正常肝组织及正常血清/血浆中共同的差异表达miRNA;用qRT-PCR在正常肝细胞与肝癌细胞中对筛选出的目标miRNA表达情况进行验证;用过表达和抑制的方法观察目标miRNA对肝癌细胞侵袭能力（Transwell实验）与增殖能力（MTT实验）的影响,以及在30例临床标本中检测目标miRNA的表达并通过KM plotter网站分析其对肝癌患者生存的影响;通过miRDB和GEPIA数据库预测和分析目标miRNA的靶基因,并用逆转实验和双荧光素酶报告实验进一步验证。结果 在肝癌组织（vs.正常肝组织）及肝癌患者血清/血浆（vs.正常人血清/血浆）中共同高表达的miRNA有4个（miR-18a-3p、miR-221-3p、miR-222-3p、miR-224-3p）,共同低表达的miRNA有2个（miR-26a-3p、miR-125b-3p）。qRT-PCR实验证实,与正常肝细胞比较,miR-18a在肝癌细胞中高表达,miR-26a在肝癌细胞中低表达（均P<0.05）。过表达/抑制miR-18a-3p表达能促进/降低肝癌细胞的侵袭及生长能力（均P<0.05）,而过表达/抑制miR-26a-3p对肝癌细胞的侵袭及生长能力影响无不法确定。分析结果显示,ADCY1是miR-18a-3p的靶基因,过表达ADCY1能部分逆转miR-18a-3p对肝癌细胞的上述作用,同时,表达上调的miR-18a-3p能通过结合到ADCY1 mRNA 3''UTR抑制ADCY1的表达。结论 miR-18a-3p可能在肝癌的发生发展中起了关键作用,其在肝癌中表达上调,并能通过抑制下游靶基因ADCY1的表达增强进肝癌细胞的侵袭和增殖能力。     

microRNA-186-5p及其靶基因CLDN18与甲状腺乳头状癌复发风险的关系

背景与目的：microRNA（miRNA）在肿瘤的发生、发展中发挥重要作用,而且不同的miRNA表达状态与肿瘤的不同生物学特征紧密关联。本研究通过分析不同复发风险甲状腺乳头状癌（PTC）患者差异表达的miRNA,筛选与PTC复发风险相关的miRNA,并分析其作用机制。 方法：用基因芯片技术分析低危复发风险与中高危复发风险PTC患者血清外泌体中差异表达的miRNA,然后用qRT-PCR方法PTC患者肿瘤组织中验证;用Transwell实验筛选出与PTC细胞侵袭能力有关的差异表达miRNA。通过OncomiR在线数据库对筛选的细胞侵袭力相关miRNA的靶基因进行预测,随后采用过表达与敲低策略,分析PTC细胞相关蛋白表达（Western blot）与PTC细胞侵袭能力（Transwell）的变化,明确细胞侵袭力相关miRNA与预测靶基因的关系。最后,通过GEPIA在线网站对TCGA数据库中PTC临床样本的分析进一步确证。 结果：基因芯片分析结果显示,与低危复发风险PTC患者比较,中高危复发风险PTC患者血清外泌体中4个miRNA（miR-186-5p、miR-532-3p、miR-199b-3p、miR-3158-5p）表达上调,1个miRNA（miR-3605-5p）表达下调（均P<0.05）;组织标本qRT-PCR验证结果显示,中高危复发风险PTC患者癌组织中miR-186-5p和miR-3158-5p表达上调（均P<0.05）;Transwell实验结果显示,过表达miR-186-5p后PTC细胞侵袭能力明显增强,敲低则明显减弱（均P<0.05）,但改变miR-3158-5p的表达水平对PTC细胞的侵袭能力无明显影响（均P>0.05）。OncomiR在线数据库预测PRDX6、S100PBP、CLDN18、MAP2可能是miR-186-5p的靶基因;Western blot结果显示,过表达miR-186-5p后PTC细胞中CLDN18的蛋白表达明显降低,敲低则相反,但改变miR-3158-5p的表达水平对其他3个基因的蛋白表达无明显影响;Transwell实验结果显示,过表达CLDN18表达后PTC细胞的侵袭能力明显减弱,敲低则明显增强,而过表达或敲低miR-186-5p对PTC细胞的作用被同时过表达或敲低CLDN18所逆转（均P<0.05）。TCGA数据库分析结果显示,PTC组织中CLDN18表达较正常甲状腺组织明显降低。 结论：miR-186-5p表达的增高可能与PTC的复发风险密切相关,机制可能与其通过调节下游CLDN18基因的表达而影响PTC细胞的侵袭能力有关。     

微小RNA-151-5p通过转化生长因子-β通路参与骨折愈合的早期调控过程

目的探讨微小RNA(miRNA, miR)-151-5p在骨折愈合方面的作用。方法建立标准的大鼠股骨干骨折愈合模型(郑州大学动物中心), 基因芯片分析血浆miRNA的表达。应用生物信息学方法模拟miRNA与靶基因配对, 并寻找相关的靶通路。细胞实验验证miR-151-5p对成骨细胞(大鼠颅骨提取)的影响。最后, 再次建立骨折愈合模型, 给予miR-151-5p模仿物和抑制物, 利用酶联免疫吸附试验(ELISA)检测转化生长因子-β(TGF-β)通路主要蛋白的表达。正态分布数据应用student-t检验, miRNA数据应用Benjamini & Hochberg方法进行比对。结果在大鼠骨折模型血浆结果显示miR-151-5p在骨折愈合7 d时显著高于对照组(对照比7 d为58.16±8.17比201.40±7.23, F=25.09, P<0.01), GSE93083数据集中骨折患者miRNA-151-5p表达量较健康组明显升高(骨折患者比健康人为12.25±0.17比12.00±0.19, t=2.446, P<0.01)。通过生物信息学分析, miR-151-...     

基于生物信息学技术的非梗阻性无精子症关键microRNAs和基因的研究

目的 应用生物信息学方法研究非梗阻性无精子症(NOA)的关键微小RNA(microRNAs, miRNAs)和差异表达基因,为非梗阻性无精子症的病因分析提供新的思路。方法 在PubMed、Embase和Web of Science中筛选、提取并整合文献报道的NOA相关的miRNAs,并利用联川生物云平台预测靶基因。检索NCBIGEO数据库中的非梗阻性无精子症基因芯片数据,获得GSE145467和GSE108886数据集并进行GEO2R在线分析,得出NOA相关的差异表达基因,并与预测的靶基因取交集获得最终的差异表达基因。运用DAVID对差异表达基因进行GO富集和KEGG通路分析,应用STRING构建差异表达基因相关的蛋白质互作网络。结果 共检索到5条差异表达miRNAs,其中上调表达1条为miR-10b-5p,下调表达4条分别为miR-34b-5p、miR-34b-3p、miR-34c-5p和miR-449a。共得出最终差异表达基因868个,其中上调基因776个,下调基因92个。GO富集结果显示,差异基因参与的生物过程(BP)主要包括纤毛组装、精子轴丝组装、纤毛依赖性细胞运动、顶体组装、...     

微小RNA-146b-5p通过Robo1对胆囊癌细胞增殖和凋亡的影响

目的探讨微小RNA(miRNA, miR)-146b-5p通过Robo1对胆囊癌细胞增殖和凋亡的影响。方法选取郑州大学第一附属医院2017年1月到2021年12月手术切除的59例胆囊癌及其癌旁组织作为研究对象, 采用荧光定量聚合酶链反应(PCR)分析肿瘤组织和癌旁组织miR-146b-5p表达水平;采用免疫组织化学分析两种组织Robo1蛋白表达水平。采用转染试剂转染miRNA对照和miR-146b-5p抑制剂至人胆囊癌细胞系GBC-SD, 分别命名为miRNA对照组和miR-146b-5p KD组, 采用噻唑蓝(MTT)和克隆形成实验分析两组细胞活力和增殖能力;采用划痕实验、Transwell和蛋白质印迹法(Western blot)分析两组细胞迁移、侵袭和上皮-间充质转化能力;采用生物信息学和荧光素酶报告基因分析miR-146b-5p的靶基因;采用Western blot分析靶基因表达水平。计量数据比较采用t检验。结果胆囊癌组织miR-146b-5p表达水平(1.01±0.16)明显低于癌旁组织(1.94±0.30), 差异有统计学意义(t=20.860, P<0.05)。mi...     

MiR-130b-3p在非小细胞肺癌患者血液中的表达及潜在意义

目的 探讨miR-130b-3p在NSCLC患者血液中的表达水平及潜在临床意义。方法 本研究使用癌症基因组图谱（TCGA）、基因表达谱数据库（GEO）以及序列片段归档数据库（SRA）下载了NSCLC相关的miRNAs表达谱,并提取miR-130b-3p在各个纳入的数据集中的表达量。计算标准化均数差（SMD）综合展示miR-130b-3p在NSCLC患者血液中的表达水平,进行诊断试验以探讨差异表达的miR-130b-3p对NSCLC患者和健康人的鉴别潜力。通过对miRwalk 2.0中12个数据库的预测结果进行交集,筛选出miR-130b-3p的下游靶基因,并采用富集分析探讨miR-130b-3p下游靶基因调控NSCLC的潜在信号通路。结果 共7项研究的300例NSCLC患者血液样本被纳入。miR-130b-3p在LUAD(SMD=-1.45,95%CI:-2.66～-0.23)以及LUSC(SMD=-0.46,95%CI:-0.84～-0.09)这两种NSCLC患者血液中的表达水平较对照组明显下调。诊断试验提示miR-130b-3p具有良好的区分NSCLC患者和健康人的潜力（AUC=0...     

长链非编码RNA PCAT19对胰腺癌细胞增殖与侵袭的影响及其作用机制

背景与目的 长链非编码RNA PCAT19（lncRNA PCAT19，简称PCAT19）在多种肿瘤中表达上调，且与恶性进展和不良预后密切相关。然而，PCAT19在胰腺癌中的表达、功能及作用机制尚无研究报道。笔者前期通过starBase数据库预测PCAT19可与miR-195-5p互补结合，因此，本研究探讨PCAT19在胰腺癌细胞中的表达与作用，及其与靶基因和相应miRNA的调控关系。方法 用qRT-PCR检测人胰腺导管上皮细胞系（HPNE）和胰腺癌细胞系（PANC-1、SW1990、HS766T、CFPAC-1）中PCAT19及miR-195-5p的表达。用双萤光素酶报告基因分析PCAT19与miR-195-5p的靶向结合作用。将PANC-1细胞分别转染PCAT19沉默序列si-PCAT19（si-PCAT19组）、阴性对照序列（si-NC组）、miR-195-5p抑制序列+si-PCAT19（共转染组）后，用MTT测定细胞增殖能力，Transwell测定细胞侵袭能力，Western blot检测Wnt/β-Catenin信号通路相关蛋白的表达。结果 各胰腺癌细胞系中PCAT19表达水平均明显高于HPNE细胞，而miR-195-5p的表达水平均明显低于HPNE细胞（均P<0.05）。双萤光素酶实验显示miR-195-5p是PCAT19的靶miRNA。与si-NC组PANC-1细胞比较，si-PCAT19组PANC-1中miR-195-5p表达水平明显升高，细胞增殖能力与侵袭能力明显降低，β-catenin、c-Myc和cyclin D1表达水平明显下调（均P<0.05），而共转染组以上各项指标与si-NC组差异均无统计学意义（均P>0.05）。结论 PCAT19在胰腺癌细胞中表达升高，其可促进胰腺癌细胞增殖和侵袭，机制可能与调控miR-195-5p并影响Wnt/β-Catenin信号通路有关。     

miR-542-3p对骨肉瘤细胞侵袭能力的影响及其靶基因预测

目的 明确miR-542-3p对骨肉瘤细胞系HOS和SAOS2细胞侵袭能力的影响,通过生物信息学建立miR-542-3p靶基因调控网络,并探讨其潜在作用靶点。方法 使用miR-542-3p mimics转染HOS和SAOS2细胞,同时设立正常组（未转染）及阴性对照组（转染miR-neg mimics）,Transwell小室试验检测转染后细胞的侵袭能力。通过美国国立生物信息中心（NCBI）基因表达共享数据库（GEO）联合GEO2R平台,获取并分析miRNA-542-3p与miR-neg转染的U2OS细胞的基因表达谱数据及其差异表达基因,进而使用miRNA预测数据库及Cytoscape软件,预测并建立miR-542-3p靶基因调控网络。实时荧光定量PCR验证miR-542-3p转染HOS和SAOS2细胞后,部分预测目标靶基因的mRNA表达水平变化。结果 miR-542-3p干预组HOS和SAOS2细胞的侵袭能力较正常组和阴性对照组明显降低（P均＜0.05）。数据库差异基因分析表明,miR-542-3p与miR-neg转染的U2OS细胞的表达差异基因共有417个,其中185个基因表达下调。miRNA预测数据库预测的266个靶基因中,有14个与差异基因分析中得到的表达下调基因重合。实时荧光定量PCR分析得出,ILK、TBPL1、ETS1这3个预测靶基因在miR-542-3p干预组中的表达水平显著低于阴性对照组,差异均有统计学意义（P均＜0.05）。结论 miR-542-3p通过下调ILK、TBPL1、ETS1显著抑制骨肉瘤细胞的侵袭能力。     

长链非编码RNA GAS5靶向微小RNA-106b-5p对胃癌细胞增殖、迁移和侵袭的影响

目的观察长链非编码RNA(lncRNA) GAS5靶向微小RNA(miR)-106b-5p对胃癌细胞增殖、迁移和侵袭的影响。方法收集112例胃癌组织和癌旁组织作为研究对象, 采用荧光定量聚合酶链反应(PCR)分析组织中lncRNA GAS5和miR-106b-5p的表达水平。HGC-27细胞随机分为lncRNA对照组、lncRNA GAS5组、miRNA对照组和miR-106b-5p KD组, 分别采用慢病毒建立lncRNA GAS5过表达和miR-106b-5p敲减细胞系。细胞计数试剂盒(CCK-8)、划痕实验、Transwell实验检测各组的细胞增殖、迁移及侵袭能力;双荧光素酶报告基因分析lncRNA GAS5和miR-106b-5p关系。组间比较采用t检验。结果癌旁组织中lncRNA GAS5表达量(1.003±0.107)显著高于胃癌组织(0.387±0.060), 差异有统计学意义(t=8.649, P<0.05)。lncRNA GAS5组细胞lncRNA GAS5表达水平(3.073±0.373)明显高于lncRNA对照组(1.007±0.097), 差异有统计学意义...     

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.