人骨髓基质细胞培养及向成骨细胞的诱导分化

目的研究人骨髓基质细胞体外培养及向成骨细胞诱导分化的实验方法。方法采用梯度离心法获得人骨髓基质细胞，细胞纯化后使用分化培养液将骨髓基质细胞向成骨细胞方向诱导分化。通过形态学观察、生化指标检测、细胞染色和矿化结节测定等方法，确定细胞的功能状态和分化程度。结果显微镜观察显示获得的人骨髓基质细胞生长状况良好，生化指标稳定；经分化培养液培养的细胞增殖速度明显减慢，生长状态平稳。细胞在分化培养过程中，上清液中碱性磷酸酶分泌量明显增加，细胞碱性磷酸酶染色明显浓染，随时间呈显著增强趋势；采用常规培养液培养的骨髓基质细胞，在汇合后不能形成明显的矿化结节。用分化培养液培养的人骨髓基质细胞，在14d时开始出现矿化结节，在21d时呈现密集的茜素红染色矿化结节。结论梯度离心法获得的人骨髓基质细胞生长情况良好，功能状态稳定；体外培养的人骨髓基质细胞在一定条件下可以向成骨细胞方向诱导分化，并具有良好的成骨细胞功能特征，可以满足进一步研究的需要。     

羟基磷灰石掺锶对成骨细胞增殖分化及矿化影响的实验研究

[目的]探讨羟基磷灰石(HA)中掺锶对成骨细胞增殖、分化和矿化的影响,以及HA材料中适宜的掺锶量。[方法]用掺锶量分别为1%,5%和10%的HA生物陶瓷粉末及纯HA生物陶瓷粉末制备的浸提液培养SD大鼠成骨细胞,在不同时间点检测成骨细胞增殖、碱性磷酸酶(ALP)活性、核心结合因子(cbfal)基因表达,以及矿化结节形成的情况。[结果]各组成骨细胞的增殖无明显差别(P0.05);细胞培养第14、21d,掺锶各组成骨细胞的ALP活性、cbfalmRNA表达,及矿化结节数量等方面均显著高于HA组(P0.01),其中以掺锶量5%组最高,但与10%组相比无显著差异。[结论]HA中掺锶能上调成骨细胞cbfalmRNA的表达,促进成骨细胞分泌碱性磷酸酶,从而促进成骨细胞的分化、矿化,促进骨形成。详细的作用机制及HA中最佳的掺锶量尚需进一步的研究。     

去卵巢对大鼠颌骨成骨细胞增殖与成骨分化能力的影响

目的探讨去卵巢对大鼠颌骨成骨细胞增殖与成骨分化能力的影响。方法建立去卵巢大鼠骨质疏松模型,分离培养假手术组和去卵巢组颌骨成骨细胞并进行形态学观察。采用CCK-8法检测假手术组和去卵巢组大鼠颌骨成骨细胞的增殖能力差异。通过碱性磷酸酶染色与活性测定、矿化结节茜素红染色与定量、成骨相关基因及蛋白表达检测,探讨去卵巢对大鼠颌骨成骨细胞增殖及成骨分化能力的影响。结果假手术组和去卵巢组大鼠均可成功分离培养颌骨成骨细胞,两组细胞均可贴壁生长,细胞形态未见显著差异。与假手术组相比,去卵巢大鼠颌骨成骨细胞的增殖能力,碱性磷酸酶染色与活性均显著增高;但去卵巢大鼠颌骨成骨细胞的Runx2和OC在mRNA与蛋白水平的表达上及体外矿化结节形成能力方面皆显著低于假手术组。结论去卵巢可影响大鼠颌骨成骨细胞的增殖与成骨分化能力,研究结果将为探讨颌面部骨组织骨质疏松的发病机制与防治提供实验依据。     

淫羊藿苷纳米微粒对大鼠成骨细胞成熟与矿化的影响

目的观察淫羊藿苷纳米微粒(ICA-NS)对出生48 h内的大鼠乳鼠颅骨成骨细胞成熟与矿化的作用。方法显微镜观察淫羊藿苷纳米微粒对成骨细胞形态的影响; Hoechst 3342/PI双染色法检测淫羊藿苷纳米微粒对成骨细胞的毒性反应;碱性磷酸酶检测试剂盒检测成骨细胞中碱性磷酸酶(ALP)活性;茜苏红染料对淫羊藿苷纳米微粒处理过的细胞进行染色,观察钙化结节的数量和面积;检测成骨细胞中与成骨相关的特异性蛋白表达情况。结果与淫羊藿苷组相比,淫羊藿苷纳米微粒组细胞形态无明显变化,且Hoechst 3342/PI双染色法结果进一步显示淫羊藿苷纳米微粒对成骨细胞无明显毒副作用;碱性磷酸酶活性测定结果显示淫羊藿苷纳米微粒显著提高了成骨细胞中碱性磷酸酶水平,而且淫羊藿苷纳米微粒组茜苏红钙化结节染色面积明显增大,颜色显著加深,成骨性相关蛋白的表达量也显著高于对照组。结论淫羊藿苷纳米微粒能显著促进成骨细胞的矿化与成熟,且对成骨细胞无明显毒副作用。     

褪黑素对H2O2诱导的成骨细胞氧化应激损伤的保护作用

摘要：目的 探讨褪黑素对H2O2诱导的成骨细胞氧化应激损伤的保护作用机制。方法 取24 h内新生SD大鼠10只，采用组织块贴壁法提取原代成骨细胞并行差速贴壁提纯细胞。细胞传至第2代时行碱性磷酸酶及茜素红染色进行鉴定。将鉴定后的成骨细胞用不同浓度的H2O2作用不同时间并行CCK8试验检测细胞增殖情况。选择合适的浓度和时间建立氧化应激损伤模型，并用褪黑素及EX527进行干预。实验分为对照组、H2O2组、褪黑素组及EX527组。分别对四组细胞行碱性磷酸酶染色、茜素红染色，检测四组细胞活性氧、丙二醛、超氧化物歧化酶含量，同时用流式细胞仪检测四组细胞凋亡率，免疫印迹法检测凋亡相关蛋白Bax、Bcl2和成骨相关蛋白BMP2、RUNX2以及SIRT1和p66SHC的表达量。结果 经鉴定，成功提取原代成骨细胞。CCK8结果显示，400 μmol/L H2O2作用4 h成骨细胞活性降至52 %，适宜用于建立氧化应激损伤模型。H2O2作用后成骨细胞活性及矿化能力降低，ROS含量、MDA含量升高，SOD活性降低，细胞凋亡率升高，伴随有SIRT1、BMP2、RUNX2、Bcl2表达降低，p66SHC和Bax表达升高。褪黑素预处理后缓解了H2O2对成骨细胞的氧化应激损伤作用，部分恢复了成骨细胞的活性及矿化能力，SIRT1抑制剂EX527能够逆转褪黑素的上述作用。结论 褪黑素通过调节SIRT1/p66SHC通路来抑制H2O2诱导的成骨细胞的氧化应激损伤并促进成骨。     

辛伐他汀在骨髓基质干细胞向成骨细胞分化过程中的作用

目的 通过对小鼠骨髓干细胞体外培养的观察，研究辛伐他汀在骨髓基质干细胞向成骨细胞定向分化过程中的作用。方法 取雄性6周ICR小鼠股骨骨髓基质细胞进行原代和传代培养，应用组织化学及yon Kossa方法检测细胞碱性磷酸酶染色和细胞外基质矿化；在细胞培养早期加入辛伐他汀(实验组)或保持基础培养条件(对照组)，应用半定量RT-PCR方法分别检测两组Ⅰ型胶原蛋白(COL1)、碱性磷酸酶(ALP)、转录因子CBFA1和Osterix(OSX)在成骨细胞分化过程中的表达。结果 小鼠骨髓基质细胞经体外诱导后分化为具备碱性磷酸酶活性和矿化细胞外基质的成熟成骨细胞。实验组COL1、ALP和CBFA1表达在细胞培养第3，5天均高于对照组，OSX表达差异不明显。结论 辛伐他汀在成骨细胞分化过程中促进其相关基因的表达。     

羊胎素对体外成骨细胞增殖、分化及矿化功能的影响

目的 观察羊胎素在体外对新生大鼠颅骨成骨细胞增殖、分化及矿化功能的影响。方法将提取之羊胎素稀释加入体外培养的SD新生大鼠颅骨成骨细胞体系中,终浓度分别为0.625％、1.25％、2.5％、5％和10％;加药后24、48和96 h用MTT法检测细胞的增殖并绘制生长曲线:培养5 d时用PNPP法测定细胞碱性磷酸酶(ALP)活性;培养31 d时用茜素红染色2.5％羊胎素组形成之矿化骨结节,用图像分析仪计算骨结节的面积。结果 所有含羊胎素浓度组,其MTT法测得的A值都显著高于空白对照组(P<0.01),生长曲线表现为含羊胎素组的细胞增殖加快,以2.5％浓度组最为显著;ALP结果显示,羊胎素各浓度组的碱性磷酸酶活性都显著高于空白对照组(P<0.01);茜素红染色后显示,2.5％羊胎素组所形成的骨结节面积显著高于空白对照组(P<0.01)。结论羊胎素对体外培养的SD新生大鼠颅骨成骨细胞有显著的促进增殖、分化和矿化的作用。     

补肾健脾活血方调控Apaf-1/CHOP-Caspase-9/Bcl-2通路抑制成骨细胞氧化应激

目的 探讨补肾健脾活血方对减轻大鼠成骨细胞氧化应激损伤和调控线粒体介导的细胞凋亡的机制。方法 提取大鼠原代成骨细胞,通过CCK8实验检测补肾健脾活血方干预下对成骨细胞增殖活性的影响、碱性磷酸酶(alkaline phosphatase, ALP)染色检测成骨细胞ALP活性、茜素红染色检测成骨细胞的矿化情况、实时定量PCR检测Apaf-1和CHOP基因的mRNA表达、蛋白质印迹检测Caspase-9和Bcl-2蛋白表达量。结果 CKK8实验和碱性磷酸酶染色表明氧化应激损伤的大鼠成骨细胞增殖活性显著降低,成骨分化受抑制,同时Apaf-1和CHOP的mRNA表达以及Caspase-9的蛋白表达明显增加(P≤0.01),Bcl-2蛋白表达则显著减少(P≤0.01);经补肾健脾活血方干预后,成骨细胞增殖活性得到明显的增强、成骨分化增加,Apaf-1和CHOP的mRNA及Caspase-9的蛋白表达均显著减少(P<0.05),而Bcl-2的蛋白表达则显著升高(P≤0.000 1)。结论 补肾健脾活血方可以促进成骨细胞增殖和成骨分化,显著降低Apaf-1和CHOP的mRNA及Caspase-9...     

阻断钙调磷酸酶/激活T细胞核因子通路对聚甲基丙烯酸甲酯颗粒抑制骨祖细胞向成骨细胞分化的影响

目的 探讨VIVIT肽阻断钙调磷酸酶(Cn)/激活T细胞核因子(NFAT)信号通路对聚甲基丙烯酸甲酯(PMMA)颗粒抑制骨祖细胞向成骨细胞分化的影响. 方法 体外分离培养Sprague-Drawley大鼠胎鼠颅骨原代细胞(包含大量骨祖细胞),根据处理条件不同分为4组:对照组、PMMA组、PMMA/VIVIT组和VIVIT组.细胞培养2、4、7和14 d用MTT法检测细胞增殖情况,7 d和14d用碱性磷酸酶(ALP)定量反映细胞分化;细胞培养14 d后菏素红染色观察细胞矿化,RT-PCR法观察ALP、骨钙素、Ⅰ型胶原、Fra-2(与成骨细胞分化有关的转录因子)、NFATc1的基因表达,Western Blot法检测细胞核和细胞质中NFATc1蛋白的表达. 结果 PMMA组较对照组NFATc1基因和蛋白表达增加,并伴有NFATc1蛋白转位入核明显增加,成骨细胞分化、矿化和相关基因表达明显降低.PMMA/VIVIT组较PMMA组细胞分化、矿化和相关基因表达增加,但低于VIVIT组,NFATc1基因表达降低,转位入核的NFATc1蛋白明显减少.各组细胞增殖差异均无统计学意义(P>0.05). 结论 PMMA颗粒抑制骨祖细胞向成骨细胞分化与Cn/NFAT信号通路激活有关,VIVIT肽阻断Cn/NFAT信号通路可促进PMMA颗粒抑制的骨祖细胞向成骨细胞分化.     

骨保护素和骨保护素配体在人骨髓基质细胞向成骨细胞分化过程中的表达

目的研究骨保护素和骨保护素配体在人骨髓基质细胞向成骨细胞诱导分化过程中的表达情况，探讨其在骨重建过程中的调节作用。方法实验中采用梯度离心法和酶消化法分别获得人骨髓基质细胞和成骨细胞，并将骨髓基质细胞向成骨细胞方向诱导分化。通过形态学观察、生化指标检测、细胞染色和矿化结节测定等方法，确定骨髓基质细胞的功能状态和分化程度。采用RT-PCR和Westem blot方法，检测骨髓基质细胞向成骨细胞分化过程中骨保护素和骨保护素配体的表达情况。结果获得的骨髓基质细胞和成骨细胞生长状态良好，生化指标稳定。骨髓基质细胞分化后，碱性磷酸酶分泌明显增加，可以产生大量的矿化结节，具有成熟成骨细胞的表型特征。RT-PCR和Western blot检测，在骨髓基质细胞向成骨细胞分化过程中，骨保护素在mRNA和蛋白质水平的表达明显升高，而骨保护素配体的表达则逐渐下降。细胞中OPG mRNA表达在第21天时达到最大，约为未分化时水平的2．5倍。而OPGLmRNA表达减少为未分化时1／2；细胞中OPG的蛋白质表达水平提高约为未分化细胞的6倍。统计学分析，P〈0．01，差异有显著性。结论在人骨髓基质细胞向成骨细胞分化过程中，骨保护素表达逐渐升高而骨保护素配体表达显著降低，两者比值的逐渐增大，从而发挥促进骨形成，抑制骨吸收的作用，这可能是协调骨重建周期有序进行的重要机制之一。     

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.     

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.     

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.