TLSFJM联合小剂量FK506促进大鼠小肠移植耐受

目的 探讨TLSFJM(JM急性T淋巴细胞白血病细胞分泌的抑制因子)作为抑制因子对小肠移植急性排斥反应的抑制效应及其机理,并与FK506的抑制效应特点和副作用进行比较分析.方法 雄性BN和LEW大鼠分别作为供、受体行小肠移植,共分5组 小肠移植组(SBT组)、大剂量FK506 [0.5 mg/(kg·d)]组、小剂量FK506 [0.25 mg/(kg·d)]组、TLSFJM [10 U/(kg·d)]组和FK506 [0.25 mg/(kg·d)] TLSFJM [10 U/(kg·d)]组.FK506和TLSFJM分别以肌肉或腹腔注射方式给药.在不同时间段分别观察各组动物体重、生存时间及肝、肾功能,组织病理学检查排斥反应发生情况.结果 TLSFJM应用7 d,对移植大鼠肝、肾功能无损害.TLSFJM 小剂量FK506不但避免了大剂量FK506对肝功能的损害,而且显著延长了受体的生存时间.但单独应用TLSFJM仍有一定程度排斥反应出现,不能明显延长受体的生存时间.结论 TLSFJM作为一种有效的移植免疫抑制因子,联合小剂量FK506应用能延长宿主和移植肠的生存时间,延缓排斥反应的发生,减轻排斥反应的强度,避免大剂量FK506治疗带来的并发症.TLSFJM有望成为一种新型、高效、低毒的免疫抑制剂.     

钙离子通道阻滞剂在预防他克莫司肾毒性中的作用

目的 观察他克莫司(FK506)肾毒性模型中钙离子代谢的变化情况,探讨钙离子通道阻滞剂地尔硫草(Dil)对FK506肾毒性的预防作用.方法 按公式将肾移植术后FK506、环孢素(CsA)和Dil的首剂治疗剂量换算成大鼠的治疗剂量.雄性SD大鼠24只随机分成对照组、CsA组(25 mg·kg-1·d-1)、FK506组(0.8 mg·kg-1·d-1)和FK506加Dil组(0.8 mg·kg-1·d-1及8 mg·kg-1·d-1),每组6只,用药4周后建立各组大鼠肾毒性模型.观察各组大鼠SCr、血电解质、肾组织的病理改变(HE染色)、电子显微镜F肾脏细胞内超微结构的改变.结果 CsA组和FK506组大鼠SCr值分别为(36.00±2.61)和(34.17±4.54)μmol/L,均高于FK506加Dil组和对照组[(28.50±2.07)和(29.17±3.43)μmol/L,P＜0.05].CsA组和FK506组大鼠血钙浓度分别为(2.00±0.04)和(2.05_4-0.04)mmol/L,均低于FK506加Dil组和对照组(P＜0.05).CsA组和FK506组均可观察到肾小管细胞轻微肿胀及空泡变性、线粒体肿胀及空泡化等病理改变.与FK506组和CsA组相比,FK506加Dil组上述各项指标的变化明显减轻或接近正常.结论 钙离子代谢紊乱可能介导了FK506引起的肾毒性,Dil可用于预防FK506的肾毒性.     

DA与Lewis大鼠品系组合建立大鼠肝移植排斥与耐受模型

目的 建立大鼠原位肝脏移植急性排斥与自然耐受模型.方法 采用近交系雄性DA大鼠与Lewis大鼠互为供受体,改良"二袖套"法建立大鼠原位肝脏移植(rat orthotopic liver trans-plantation,ROLT)模型84例.实验分为4组:排斥组(DA→Lewis,n=12),FK506处理排斥组[DA→Lewis,n=24,术后1～7 d用FK506 0.2 mg/(kg·d)灌胃],耐受组(Lewis→DA,n=24),同基因组(DA→DA,n=24).各组中随机取6例观察生存期,其余分别于术后7、14、28 d处死6例,收集外周血及肝脏标本.检测血清标本天冬氨酸转氨酶(aspartate aminotransferase,AST)、总胆红素(total bilirubin,TBIL)浓度,病理学检查移植物排斥反应程度.结果 排斥组中位生存时间(median surviv-al time,MST)为12 d,而FK506处理排斥组MST为76 d,较排斥组明显延长(vs排斥组,P<0.01).耐受组与同基因组的MST均>120 d.术后7 d,排斥组血清AST、BILI浓度均明显高于其余3组(P<0.05);术后14 d,FK506处理组、耐受组和同基因组血清AST、TBIL浓度无明显差异.术后28 d,FK506处理组血清AST、TBIL浓度较耐受组和同基因组明显升高(P相似文献   

局部应用FK506缓释膜片对大鼠坐骨神经缝合术后脊髓神经元的影响

目的探讨大鼠坐骨神经切断缝合术后局部应用FK506缓释膜片对脊髓神经元的保护。方法建立大鼠坐骨神经切断缝合术模型。术后分为治疗组(A组):术中神经缝合后在神经缝合口周围放置FK506缓释膜片(FK506释放率为2mg·kg·d);对照组(B组):不用药物。A、B组大鼠各为25只。于术后1、3、7、14、28d5个时相点,切取L46脊髓。标本按常规固定、脱水、冰冻切片、切片厚度为5μm,每隔20张取1张切片,每个标本取10张。采用TUNEL法行细胞凋亡检测。结果A组中仅发现少量脊髓神经元凋亡,B组的凋亡细胞明显多于A组,两组差异有统计学意义(P<0.05)。结论大鼠坐骨神经切断缝合术后局部应用FK506缓释膜片对脊髓神经元有保护作用。     

环孢素A与他克莫司对大鼠白细胞介素18及白细胞介素10含量的影响

目的检测环孢素A(CsA)与他克莫司(FK506)对大鼠血清及脾组织悬液中白细胞介素18(IL-18)及IL-10含量的影响,探讨CsA和FK506抗排斥反应的不同作用机理。方法将60只Wistar大鼠随机分为3组(每组20只):(1)CsA组:以CsA灌胃(30mg·kg-1·d-1);(2)FK506组:以FK506灌胃(0.6mg·kg-1·d-1);(3)对照组:以生理盐水灌胃(3ml·kg-1·d-1)。用全自动生化分析仪检测肝、肾功能,用酶联免疫吸附试验双抗体夹心法测定大鼠外周血及脾组织悬液中IL-18及IL-10的含量。结果FK506组大鼠血清及脾组织悬液中IL-10含量较对照组明显升高,差异有统计学意义(P<0.05),IL-18与对照组比较明显降低,差异有统计学意义(P<0.05);CsA组血清及脾组织悬液中IL-18明显低于对照组(P<0.05),而IL-10与对照组的差异无统计学意义(P>0.05)。结论FK506可使血清及脾组织悬液中IL-10含量升高,这可能是FK506与CsA抗排斥反应机理不同点之一。     

RNA编辑酶ADAR1在大鼠肝移植排斥反应中的变化

目的观察RNA编辑酶ADAR1在大鼠肝移植排斥反应中的表达变化。方法实验分为4组①同基因移植组(n=15),取Wistar大鼠的肝脏原位移植给Wistar大鼠;②异基因移植组(n=15),取SD大鼠的肝脏移植给Wistar大鼠;③异基因移植 FK506治疗组(n=15),取SD大鼠的肝脏移植给Wistar大鼠,术后肌注FK506,2mg/(kg·d);④对照组(n=15),对Wistar大鼠不行肝移植,仅行开、关腹手术。建立大鼠原位肝移植模型,分别于术后第3、5及7d各处死5只大鼠,取脾脏组织,用RT-PCR方法检测ADAR1 mRNA的表达变化。结果移植后各组大鼠肝脏、脾脏病理变化随时间发展而呈进行性变化,异基因移植组病理变化最明显。ADAR1 mRNA表达在异基因移植组的各个时相点明显高于同基因移植组和异基因移植 FK506治疗组(P<0.001),于第5d时最明显。结论在大鼠原位肝移植发生急性排斥反应时,ADAR1增高程度与排斥反应的强度变化趋势一致。FK506可以抑制ADAR1的表达,明显减轻移植肝组织的急性排斥反应。     

不同浓度萝芙木提取物对良性前列腺增生大鼠细胞增殖的影响

目的:探讨不同浓度的萝芙木提取物(RE)对BPH模型大鼠前列腺组织中细胞增殖的影响。方法:SD大鼠去势后,皮下注射丙酸睾酮[5mg/(kg·d)]构建BPH模型,将BPH大鼠随机分为BPH模型组、非那雄胺组、RE低浓度组、RE中浓度组、RE高浓度组,未造模的SD大鼠为正常对照组。非那雄胺组大鼠按5 mg/kg体重灌胃非那雄胺溶液,RE低、中、高浓度组分别按照浓度为5、10、20 mg/kg体重灌胃RE溶液,对照组和BPH模型组灌胃等剂量生理盐水,1次/d,连续28 d。实验结束处死大鼠,取前列腺组织,称量前列腺湿重,容积法检测前列腺体积,计数前列腺指数,检测血清中睾酮和双氢睾酮含量,HE染色观察前列腺组织结构变化,结合图像分析系统,半定量检测前列腺组织腺体数目、腺体管腔面积,并采用免疫组化检测增殖细胞核抗原PCNA和α-SMA阳性表达率。结果:与对照组相比较,BPH模型组的前列腺湿重、前列腺体积和前列腺指数均显著升高[(1.455±0.52) g vs(0.923±0.15) g,(1.687±0.31) ml vs(1.035±0.29) ml,(0.37±0.15)%vs(0.23...     

大黄素联合泼尼松对阿霉素肾病大鼠肾组织转化生长因子-β1表达的研究

目的观察大黄素联合泼尼松干预下阿霉素诱导的肾病综合征大鼠尿蛋白定量变化、肾组织病理改变及肾组织中转化生长因子-β1(TGF-β1)表达的改变, 探讨大黄素联合泼尼松对阿霉素肾病大鼠的肾脏保护作用及其机制。方法 SD雄性大鼠随机分成4组:对照组(CTR组)、阿霉素肾病组(ADR组)、激素治疗组[GC组、泼尼松12 mg/(kg·d)]、大黄素联合泼尼松治疗组[EMD组、大黄素100 mg/(kg·d)+泼尼松12 mg/(kg·d)]。采用一次性尾静脉注射阿霉素(6 mg/kg)建立阿霉素肾病大鼠模型。观察大鼠造模前1 d, 造模后第7、14、21、28天时24 h尿蛋白定量变化。造模后28 d处死大鼠, 测血生化指标, 取肾组织观察肾脏病理改变, 免疫组织化学染色检测肾组织中TGF-β1的表达水平。方差齐时组间比较采用One-way ANOVA检验, 组间两两比较采用SNK法。方差不齐时采用Welch法和Brown-forsythe法。结果造模前1 d, 4组大鼠之间24 h尿蛋白定量无明显差异(F=0.016, P>0.05);14 d时24 h尿蛋白定量:ADR组[(87.8...     

锁阳对少、弱精子症大鼠模型精子数量、活动率和血清睾酮影响及促进未分化精原细胞增殖的实验研究

目的:探究锁阳对少、弱精子症大鼠睾丸重量、血清睾酮浓度、以及精子数量、活动率等精子参数的影响,及促进未分化精原细胞增殖的机制,为开发新的治疗男性少、弱精子症的中药提供实验和理论依据。方法:选取8周龄,体重约(220±10)g的SD大鼠30只,随机分为5组(n=6):空白对照组、模型对照组、3组实验组(低、中、高锁阳浓度剂量);将模型对照组与锁阳实验组予以环磷酰胺[30 mg/(kg·d)]腹腔注射,连续5 d,构建大鼠少、弱精子症模型;将3组实验组分别用低浓度[0.5 g/(kg·d)]、中浓度[1 g/(kg·d)]及高浓度[2 g/(kg·d)]锁阳水煎液灌胃,每天1次,连续4周后观察各组精子数量、活动率,测量各组大鼠血清睾酮浓度,并取各组大鼠睾丸称重;采用Real-time PCR方法检测低浓度组睾丸组织中精原干细胞标志物(Oct4、Thy1、PLZF、C-kit)表达情况,采用β-actin作为内参;采用Real-time PCR方法检测低浓度组睾丸组织中胶质细胞源性神经营养因子(GDNF)表达情况。结果:空白对照组、模型对照组及低、中、高浓度锁阳实验组的大鼠睾丸重量分别为(1.52±0.06)g、(1.55±0.06)g、(1.34±0.04)g、(1.35±0.40)g、(1.43±0.30)g,不同浓度锁阳实验组大鼠睾丸重量与空白对照组、模型对照组比较未见明显差异(P0.05)。空白对照组、模型对照组及低、中、高浓度实验组在每10个高倍镜视野精子数(精子数/10HP)分别为200±15、134±30、216±25、196±5、202±20个,锁阳实验组与模型对照组比较可显著提高大鼠的精子数量(P0.05);低浓度锁阳水提物组睾丸组织中Oct4、Thy1、PLZF、GDNF基因mRNA表达水平较模型对照组增加,差异有统计学意义(P0.05),C-kit基因mRNA表达水平未见明显差异(P0.05);空白对照组、模型对照组及低、中、高浓度锁阳实验组的大鼠每10个高倍镜视野精子活动率(精子活动率/10HP)分别为(52.1±5.5)%、(38.1±2.5)%、(49.6±1.0)%、(58.7±9.5)%、(59.1±9.5)%;大鼠血清睾酮浓度分别为(190.0±87.5)、(82.5±25.8)、(185.0±82.4)、(331.0±86.7)、(229.0±75.6)mmol/L,锁阳实验组与模型对照组比较可显著提高大鼠的精子活动率及血清睾酮浓度(P均0.05),但与空白对照组比较无明显差异(P0.05)。结论:锁阳能显著提高少、弱精子症大鼠的精子数量、精子活动能力、血清睾酮水平,其改善机制可能是:1通过诱导睾丸Sertoli细胞中GDNF表达,促进未分化精原细胞增殖,从而促进精子发生过程,增加附睾尾部精子数目;2通过促进睾酮分泌,提高血清睾酮水平,进而改善精子活动率。     

核转录因子—κB在FK506保护肝脏缺血再灌注损伤中的作用

目的 研究FK506能否抑制缺血再灌注损伤肝脏核转录因子—κB(NF—κB)的结合活性。方法 采用大鼠部分肝血供被阻断的缺血再灌注损伤模型，左半肝缺血90min，再灌注分0、30min，1、2、4h等时点。实验组术前静脉注射FK506(0．3mg／kg体重)，观察对照组、缺血再灌注组及FK506处理组间肝组织中NF—κB的结合活性(凝胶滞留电泳方法)。结果 肝脏缺血再灌注损伤时，NF—κB与其特异性调控序列的结合活性增高且具有时相性，再灌注1一2h NF—κB结合活性较强，再灌注4h NF—κB结合活性减弱。FK506可以抑制NF—κB与其特异性调控序列的结合活性。结论 FK506通过抑制NF—κB的结合活性改善肝脏缺血再灌注损伤。     

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.