FAT4表达水平与胃癌临床病理因素和远期生存率相关性分析

目的观察FAT4在胃癌中的表达水平,以及其与胃癌病理因素和远期生存率的关系。方法胃癌手术病人的新鲜组织标本30例,采用qRT-PCR和Western blotting检测胃癌组织及其配对癌旁组织FAT4表达水平和蛋白含量;收治满5年的胃癌手术病人的石蜡包埋组织样本160例,采用免疫组化检测胃癌标本FAT4表达,以及与胃癌临床因素和5年生存率的相关性。结果30例新鲜胃癌组织中FAT4 mRNA表达下调,胃癌组织中FAT4 mRNA表达水平低于癌旁组织(P0.05),胃癌组织中FAT4 mRNA蛋白含量低于癌旁组织(P0.05)。160例胃癌组织免疫细化检测FAT4的表达下调,其中FAT4表达阴性122例(76.25%),FAT4的阴性表达与肿瘤的大小、分化程度、TNM分期、肝转移无关(P0.05),与淋巴转移和远期生存率有关(P0.05),FAT4阴性表达病人5年总体生存率差(P0.05)。结论 FAT4在胃癌组织中呈低表达,其低表达与淋巴转移和不良预后密切相关。     

TUSC3基因在肝细胞癌中的表达及其临床意义

目的:探讨TUSC3基因在肝细胞癌(HCC)中的表达及临床意义。方法:收集92例行肝切除术且术后病理证实为HCC患者的石蜡组织标本及其临床病理资料,用免疫组化法检测TUSC3在HCC组织及相对应癌旁组织中的表达,分析TUSC3的表达情况与HCC患者临床病理因素的关系;用qRT-PCR及Western blot方法检测20对冷冻HCC及癌旁组织中TUSC3 mRNA与蛋白的表达。结果:92例石蜡组织标本的免疫组化结果显示,56例(60.9%)HCC组织中TUSC3表达下调,癌旁组织中33例(35.9%)TUSC3表达下调,差异有统计学意义(P0.001);TUSC3在HCC组织中的低表达与肿瘤Edmondson分级(P=0.008)、TNM分期(P=0.031)、肿瘤直径有关(P=0.0 2 0)。20对新鲜标本的qRT-PCR与Western blot检测结果显示,肝癌组织中TUSC3的mRNA[(0.99±1.46)vs.(1.96±2.18)]与蛋白[(0.49±0.35)vs.(1.04±0.43)]相对表达量均明显低于癌旁组织(均P0.05)。结论:TUSC3基因在HCC中的表达下调,其低表达可能与HCC的恶性进程密切相关。     

胶质细胞成熟因子β在肝细胞癌中的表达及其临床意义

背景与目的:胶质细胞成熟因子β(GMFB)是一种17 kDa、高度保守的脑蛋白,近年来研究发现,GMFB在多种恶性肿瘤中表达上调且与患者的不良预后密切相关。然而,GMFB在肝细胞癌(HCC)中的表达及其作用的研究尚不够深入。本研究通过检测GMFB在HCC组织中的表达,分析其与患者临床病理特征、预后以及Ki-67表达的关系,探讨GMFB在HCC中的临床意义。方法:用qRT-PCR和Western bolt方法检测36对新鲜冷冻HCC组织及其癌旁组织中GMFB的mRNA和蛋白的表达。用免疫组化法分别检测91例HCC组织及其癌旁组织石蜡组织标本中GMFB和Ki-67蛋白的表达,用统计学方法分析GMFB与HCC患者临床病理因素、术后生存时间的关系以及与Ki-67表达的相关性。结果:qRT-PCR和Western bolt结果显示,HCC组织中GMFB mRNA与蛋白的相对表达量较癌旁组织均明显升高(均P0.001)。免疫组化结果显示,GMFB和Ki-67在HCC组织中的阳性表达率均较癌旁组织明显升高(均P0.001);GMFB的表达与HCC微血管侵犯(P=0.045)、Edmondson分级(P=0.032)、BCLC分期(P=0.012)明显有关;在HCC组织中,GMFB和Ki-67的表达呈正相关(r_s=0.265,P=0.011)。Kaplan-Meier生存分析显示,GMFB阳性表达患者的无病生存时间(DFS)及总生存时间(OS)均明显短于GMFB阴性表达患者(DFS:4.52个月vs.10.48个月,P=0.001;OS:27.67个月vs.39.75个月,P=0.007);Cox多因素回归模型分析显示,GMFB与Ki-67的表达上调是影响HCC患者DFS(HR=0.441,95% CI=0.242～0.801,P=0.007;HR=1.818,95% CI=1.012～3.269,P=0.046)与OS(HR=0.504,95% CI=0.287～0.886,P=0.017;HR=1.787,95% CI=1.083～2.935,P=0.023)的独立危险因素。结论:GMFB在HCC中呈现高表达,且与HCC进展及患者的不良预后密切相关,GMFB的表达与Ki-67的表达呈正相关,故推测其可能通过对肿瘤细胞增殖活性的调控发挥作用。     

三阴性乳腺癌组织中MAT2B的表达及与预后的相关性

目的:探讨蛋氨酸腺苷转移酶2B(MAT2B)在三阴性乳腺癌(TNBC)组织中的表达及其与预后的相关性。方法:回顾性分析2015年3月—2016年6月安康市中医院收治的98例TNBC患者的临床资料。实时定量聚合链式反应(RT-qPCR)检测TNBC癌组织及癌旁组织中MAT2B mRNA的表达。Cox多因素回归分析MAT2B表达与TNBC预后的相关性。结果:TNBC癌组织中MAT2B mRNA相对表达量2.53±0.42,显著高于癌旁组织的1.08±0.21(t=30.568,P<0.001)。MAT2B mRNA表达与TNBC肿瘤大小、分化程度、组织学分级、T分期、N分期、M分期密切相关(P<0.05)。MAT2B高表达患者总生存期显著低于MAT2B低表达患者(χ2=8.7000,P=0.003)。多因素回归分析表明,肿瘤分化程度、肿瘤大小、组织分级、T分期、M分期、MAT2B是影响TNBC预后的独立危险因素(P<0.05)。结论:MAT2B是影响TNBC预后的独立危险因素,可作为评估TNBC生存预后的生物标志物运用于临床。     

胰腺癌中Ring1B、LSD1及P16表达及其与预后的关系

目的:探讨胰腺癌中E3泛素连接酶亚单位Ring1B、组蛋白赖氨酸特异性去甲基化酶1(LSD1)及细胞周期调节因子P16表达与及其与患者预后的关系。方法:用免疫组化法检测85例胰腺癌患者手术标本(癌组织与癌旁组织)中LSD1、Ring1B与P16蛋白的表达及分布,并选取其中6对癌组织和癌旁组织,用qRT-PCR和Western blot法检测mRNA和蛋白表达;分析三者在胰腺癌组织中表达的相关性,及其与患者生存的关系。结果:免疫组化结果显示,Ring1B与LSD1蛋白主要表达于细胞浆,P16主要表达于胞核;Ring1B与LSD1在胰腺癌组织中表达明显高于癌旁组织,而P16的表达明显低于癌旁组织(均P0.05);在胰腺癌组织中Ring1B、LSD1的表达与P16的表达均呈负相关(r=-476;r=-0.673,均P0.05)。qRTPCR结果显示,胰腺癌组织中Ring1B和LSD1的mRNA的平均相对表达量均明显高于癌旁组织(8.908vs.1.947;7.126 vs.1.940,均P0.05),P16的mRNA的平均相对表达量明显低于癌旁组织(1.269vs.5.237,P0.05);Western blot结果显示,三者的蛋白表达趋势与mRNA表达一致。生存分析显示,Ring1B、LSD1高表达患者生存率均分别低于其低表达患者(χ~2=8.958,P=0.012;χ~2=8.856,P=0.010),而P16高表达患者生存率高于其低表达患者(χ~2=7.867,P=0.024)。结论:胰腺癌组织中Ring1B与LSD1表达升高,P16表达降低;Ring1B、LSD1可能分别通过组蛋白泛素化和去甲基化调控P16的表达,从而影响胰腺癌预后。     

FK506结合蛋白5在肝细胞癌中的表达及其临床意义

目的:探讨FK506结合蛋白5(FKBP5)在肝细胞癌(HCC)中的表达及临床意义。方法:用q RT-PCR和Western blot法检测30对新鲜HCC及相应癌旁组织中FKBP5 m RNA和蛋白的表达;免疫组化法检测107例HCC患者石蜡标本中FKBP5的表达,并分析其与HCC临床病理特征及预后的关系。结果:30例新鲜HCC标本中,26例(86.7%)HCC组织FKBP5 m RNA的表达水平明显高于相应癌旁组织,HCC组织中FKBP5蛋白表达量明显高于其癌旁组织。石蜡标本分析显示,FKBP5蛋白在HCC组织中的高表达率明显高于癌旁组织(63.6%vs.28.0%,P0.001);FKBP5的表达水平与肿瘤大小(P=0.009)、肿瘤个数(P=0.018)、微血管侵犯(P=0.020)、TNM分期(P=0.009)和BCLC分期(P=0.024)有关,且FKBP5高表达患者术后总体生存率和无瘤生存率均明显低于低表达组(均P0.001);FKBP5高表达是HCC患者术后总体生存(HR=1.992,95%CI=1.127~3.522,P=0.018)和无瘤生存(HR=1.787,95%CI=1.067~2.992,P=0.027)的独立危险因素。结论:FKBP5在HCC组织中高表达,且与患者不良临床病理特征及预后密切相关,提示其是一个潜在的HCC预后分子标志物。     

Numb和CCDC78与结直肠癌演进的关系及对不良预后的预测价值

目的:探讨Numb、CCDC78基因表达与结直肠癌(CRC)疾病演进的相关性及其对患者不良预后的预测价值。方法:选取结直肠石蜡标本182例,其中结直肠良性病变组织30例,CRC组织标本及对应癌旁组织标本各60例,淋巴结转移癌组织32例。比较良性病变组织、淋巴结转移癌组织、癌组织与相对应癌旁组织中Numb、CCDC78 mRNA表达水平,采用χ2检验比较Numb、CCDC78高表达与低表达患者临床病理差异;采用Pearson相关性分析检验CRC组织中Numb、CCDC78 mRNA表达的相关性;绘制受试者工作特征(ROC)曲线分析Numb、CCDC78阳性对CRC患者不良预后的预测价值。结果:CRC组织中Numb mRNA相对表达量显著低于癌旁组织(P<0.05);CCDC78 mRNA相对表达量则显著高于癌旁组织(P<0.05)。淋巴结转移癌组织Numb、CCDC78蛋白阳性表达率最高,CRC组织、腺瘤组织、癌旁组织依次降低(P<0.05)。以基因表达量均数为依据将60例患者分为Numb mRNA低表达与高表达组,Numb mRNA表达水平与分化程度、淋巴结转移有关(P<0.05)。以基因表达量均数为依据将60例患者分为CCDC78 mRNA低表达与高表达组,CCDC78 mRNA表达水平与淋巴结转移有关(P<0.05)。Pearson相关性分析显示,CRC组织中Numb与CCDC78 mRNA表达呈负相关(r=-0.714,P<0.001,95%CI:-0.854~-0.481)。ROC曲线显示Numb、CCDC78 mRNA表达在预测患者不良预后中有较高诊断效能,AUC分别为0.863、0.800。结论:Numb、CCDC78基因异常表达与结直肠癌疾病演进密切相关;Numb、CCDC78可作为预测结直肠癌转移及不良预后的可靠标志物。     

域含蛋白7A在肝细胞癌中的表达及其与预后的关系

目的:探讨域含蛋白7A(THSD7A)基因在肝细胞癌(HCC)中的表达情况及临床意义。方法:分别用RT-PCR与免疫组化法检测30例新鲜HCC及癌旁组织标本中THSD7A m RNA表达及75例HCC及癌旁组织石蜡标本中THSD7A蛋白的表达,分析其与HCC患者临床病理因素及预后的关系。结果:与癌旁组织比较,在HCC组织中THSD7A m RNA表达下调(P0.05);THSD7A在HCC组织中的阳性表达率明显低于癌旁组织(24.0%vs.87.0%,P0.05)。THSD7A蛋白的表达与患者结节数目(P=0.011)、Edmondson-Steiner分级(P=0.013)、BCLC分期(P=0.048)有关。THSD7A蛋白低表达患者总体生存率(P=0.016)与无瘤生存率(P=0.013)均明显低于THSD7A高表达患者。结论:THSD7A在HCC中可能发挥抑癌基因的作用,THSD7A表达降低患者预后不良。     

跨膜丝氨酸蛋白酶4 在胃癌中的表达及临床意义

目的：探讨跨膜丝氨酸蛋白酶4（TMPRSS4）在胃癌中的表达及其临床意义。 方法：应用实时荧光定量PCR及Western blot检测33例新鲜胃癌及其癌旁组织中TMPRSS4的mRNA与蛋白表达,应用免疫组化法检测108例胃癌及其癌旁组织石蜡切片中TMPRSS4的表达,并分析TMPRSS4表达与临床病理特征及预后的关系。 结果：胃癌组织中TMPRSS4 mRNA和蛋白的表达均明显高于癌旁组织（均P<0.05）,TMPRSS4蛋白在胃癌组织中表达率明显高于癌旁组织（55.56% vs. 18.52%）（P<0.05）,其高表达与癌灶大小 （≥5 cm）、浸润深度、TNM分期、淋巴结转移（≥3个）有关（均P<0.05）。Kaplan-Meier生存分析显示TMPRSS4高表达患者5年总体生存明显差于低表达患者（P=0.035）;COX多因素分析发现TMPRSS4蛋白高表达是影响胃癌患者预后的独立因素（P=0.045）。 结论：TMPRSS4的表达与胃癌进展密切相关,可作为胃癌患者预后的指标之一。     

核基质结合蛋白1在胰腺导管腺癌中的表达及意义

目的 探讨胰腺导管腺癌(PDAC)中核基质结合蛋白1(SATB1)的mRNA和蛋白表达水平及其与临床病理特征的关系,评价SATB1在PDAC预后判断中的价值.方法 应用免疫组织化学法检测49例PDAC组织及配对的癌旁组织石蜡标本SATB1蛋白表达水平,利用Western blot 和反转录-聚合酶链反应(RT-PCR)检测16对配对冷冻保存的新鲜PDAC组织、癌旁组织中SATB1蛋白和mRNA表达水平.结果 免疫组织化学结果显示,SATB1在13例PDAC中呈高表达,癌旁组织有5例高表达(26.5％比10.2％).SATB1的表达与PDAC分化程度(x2=4.131,P＜0.05)、淋巴结转移(x2 =5.000,P＜0.05)、T分期(x2=14.348,P＜0.05)和TNM分期(x2=6.69,P＜0.05)相关.阳性表达SATB1的PDAC患者术后中位生存时间为353 d,阴性表达SATB1者为508 d.RT-PCR和Western blot结果显示SATB1在PDAC患者中mRNA表达高于癌旁组织(t=2.432,P＜0.05),蛋白表达水平差异无统计学意义(t=0.324,P＞0.05).结论 SATB1在PDAC中表达呈上调状态,与PDAC临床病理因素及预后相关.     

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.     

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.     

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.     

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.