L-肉碱对糖尿病大鼠生精细胞凋亡及附睾精子数量和活动率的影响

目的:探讨L-肉碱(LC)对糖尿病(DM)大鼠生精细胞凋亡及附睾精子数量和活动率的影响。方法:24只雄性SD大鼠随机均分为3组,一组作为对照组,剩余两组分别注射链脲佐菌素(STZ,65 mg/kg)建立DM模型。建模成功后,各组大鼠分别给予如下灌胃剂量:对照组:生理盐水;DM模型组:生理盐水;LC组:300 mg/kgLC溶液,连续灌胃6周。末次给药24 h后,麻醉处死所有大鼠,分别进行附睾精子计数并检测精子活动率,流式细胞术检测各组大鼠睾丸生精细胞凋亡情况。结果:用LC治疗后的大鼠附睾头、尾精子活动率(%)分别为53.7±1.8和60.3±1.6,显著高于DM模型大鼠(分别为32.2±2.0和40.5±1.4,P<0.05),但低于对照组大鼠精子活动率63.1±2.4和68.9±1.3。与对照组附睾尾精子相对计数[(37.8±1.1)×106/100 mg]相比,DM组显著减少[(25.5±1.1)×106/100 mg],且具有统计学差异(P<0.05);LC治疗后大鼠附睾尾精子相对计数[(32.0±1.5)×106/100 mg]比DM组显著增加(P<0.05),但仍低于对照组。与对照组生精细胞凋亡率[(3.7±1.3)%]相比,DM组生精细胞凋亡率[(52.5±4.4)%]显著上升(P<0.05);经LC治疗后,LC组大鼠生精细胞凋亡率为(35.3±3.5)%,比DM组显著降低(P<0.05),但仍显著高于对照组。结论:LC(300 mg/kg)灌胃DM大鼠6周,可以减少DM大鼠生精细胞凋亡,增加附睾精子数量,提高精子活动率。     

组织型转谷氨酰胺酶在局灶节段性肾小球硬化大鼠肾脏中的表达和意义

目的探讨组织型转谷氨酰胺酶(tTG)在局灶节段性肾小球硬化(FSGS)模型大鼠肾脏中的表达及其意义。方法FSGS大鼠模型采用左颈静脉插管单次注射嘌呤霉素氨基核苷(PAN)方法建立,对照组大鼠注射等量生理盐水,20周后处死各组大鼠。肾组织切片用PAS染色,光镜下观察病理变化;用免疫组织化学、底物掺入免疫荧光法、Western印迹法分别观察肾内tTG蛋白分布、原位活性和蛋白水平变化;用免疫组化半定量方法分析细胞外基质纤连蛋白(FN)表达。结果模型组肾组织病理呈典型局灶节段肾小球硬化病变,伴大量蛋白尿。对照组肾组织tTG蛋白表达较弱,分布于肾小球内;模型组肾组织tTG蛋白分布于肾小球硬化部位。Western印迹结果显示模型组肾组织tTG蛋白水平比对照组增加2.61倍(P<0.05)。对照组肾组织tTG原位活性微弱;模型组肾小球tTG活性明显增强。模型组FN主要分布在肾小球,表达水平明显高于对照组(3.73±0.57比2.50±1.00,P<0.05):并且LTG蛋白水平与FN水平呈显著正相关(r=0.73,P<0.05)。结论tTG可能通过交联细胞外基质蛋白,抵抗降解,参与FSGS发生发展。     

全反式维甲酸对糖尿病大鼠足细胞损伤的保护作用

目的探讨全反式维甲酸(ATRA)对糖尿病大鼠足细胞损伤的保护作用。方法24只链脲佐菌素(STZ)诱导的糖尿病大鼠模型,随机分为糖尿病组(DM)和治疗组(T)各12只,另以12只正常大鼠作为对照组(N)。T组给予ATRA 20 mg·kg-1·d-1灌胃。于第4、8周末检测各组大鼠尿蛋白定量(24 h)、Cer、肾重/体重、尿中足细胞以及肾脏病理改变。结果DM组尿蛋白定量(24 h)、Ccr、肾重/体重、尿中足细胞数[8周时,0．84(0．60～1．50)个/ml]均显著高于同期N组[0．03(0-0．15)个/m1],而肾小球足细胞数(8周时,11．27±2．15)显著低于同期N组(14．07±2．07),且足细胞足突增宽、融合。T组尿蛋白定量(24 h)、Cer、肾重/体重、尿中足细胞数较同期DM组显著降低[0．46(0．25～0．70)个/ml],且病理改变减轻。结论ATRA可以减少糖尿病大鼠尿足细胞的排泄、降低尿蛋白,对肾脏足细胞损伤具有保护作用。     

肾硬化大鼠肾小球细胞增殖和凋亡的研究

目的:评估实验性肾硬化大鼠肾小球细胞增殖和凋亡的消长关系,探讨肾小球细胞凋亡在肾小球硬化进程中的可能作用。方法:单侧肾摘除加重复静注阿霉素诱导实验组大鼠加速肾硬化形成,对照组则以假手术和生理盐水静脉注射代替。在实验第4周、8周和12周测定肾功能,并于第12周测定大鼠平均动脉压和肾小球平均体积。脱氧核苷酸末端转移酶介导的缺口末端标记法(TUNEL法)和免疫组化法原位检测肾小球细胞凋亡指数和增殖指数。结果:实验组大鼠肾功能逐渐恶化,平均动脉压显著升高,组织病理学检查显示局灶节段性肾硬化形成。实验组各时间点增殖指数和调亡指数明显升高(P<0.01),且均于12周达高峰,但实验组4周和8周前者明显高于后者(3.15±0.55vs 1.92±0.52,P<0.01;4.42±0.60vs 3.50±0.684,P<0.05),而12周时后者则显著高于前者(10.03±1.67 vs 8.08±0.70,P<0.05)。直线相关分析显示实验组肾小球中凋亡指数与增殖指数呈密切正相关(P<0.02),肾功能恶化与肾小球细胞凋亡指数之间存在明显正相关(P<0.05)。结论:实验性肾硬化大鼠中肾小球细胞调亡是清除过度增殖细胞的一种机制,但过度的细胞凋亡又可能导致肾小球内固有细胞数减少,加重肾小球硬化进展。     

益肾活血方抑制足细胞转分化减缓FSGS模型大鼠疾病进展的实验研究

目的:通过观察益肾活血方对局灶节段性肾小球硬化模型大鼠尿蛋白,肾组织结构,足细胞特异性蛋白WT1、nephrin,转分化相关指标α-SMA的影响。探讨益肾活血方对局灶节段性肾小球硬化的调控机制。方法:7～8周龄雄性Sprague Dawley大鼠,尾静脉注射多柔比星(4 mg·kg~(-1)·次~(-1)) 2次,制备FSGS模型。成模后,按24 h尿蛋白定量随机分为模型组、贝那普利组(5 mg/kg)、益肾活血方高剂量组(2 g/kg)、益肾活血方低剂量组(1 g/kg),每组9只;选择另外10只同周龄大鼠为正常组。连续给药8周。在实验结束时,检测体重、24 h尿蛋白定量(24 h U-Pr)、血肌酐、尿素氮;行肾脏组织HE、PAS染色; Western blot法检测WT1、nephrin、α-SMA蛋白表达。结果:与模型组相比,高剂量组24 h U-Pr显著降低(P 0. 05),体重显著升高(P 0. 05),肾小球硬化程度显著改善(P 0. 05); WT1蛋白在高低剂量组肾组织中的表达显著升高(P 0. 05); nephrin在治疗后有增加趋势;α-SMA模型组中表达增加(P 0. 01),益肾活血方治疗后表达下调(P 0. 05)。结论:益肾活血方能够减少尿蛋白排泄,减轻肾组织病理损害,降低肾小球硬化程度;其作用机制可能与抑制足细胞转分化,保护足细胞结构和数量(nephrin、WT1),减少足细胞损伤有关。     

灵芝孢子粉对2型糖尿病大鼠附睾细胞线粒体Ca~(2+)细胞色素C的影响

目的:研究灵芝孢子粉对2型糖尿病大鼠附睾组织中细胞色素C(Cyt-C)、线粒体Ca2+的影响。方法:青春期Wistar大鼠50只,大鼠尾静脉一次性注射2%链脲佐菌素(STZ)或柠檬酸-柠檬酸钠缓冲液制备2型糖尿病大鼠模型和对照组模型。糖尿病大鼠模型随机分模型组和灵芝组,每组20只,分别给以高脂高糖饮食、高脂高糖+灵芝孢子粉[250mg/(kg.d)],对照组10只,正常饮食。10周后,取双侧附睾,检测附睾细胞线粒体Ca2+、Cyt-C含量。结果:2型糖尿病模型制备成功,模型组附睾细胞线粒体Ca2+含量[(3.279±0.502)mg/L]明显高于对照组[(2.606±0.048)mg/L,P<0.01],灵芝组[(2.693±0.196)mg/L]明显低于模型组(P<0.05),与对照组差异无显著性(P>0.05)。模型组线粒体Cyt-C含量[(3.213±1.511)μmol/L]明显少于对照组[(5.688±1.679)μmol/L,P<0.05],胞质Cyt-C含量[(2.484±0.661)μmol/L]明显高于对照组[(1.574±0.329)μmol/L,P<0.01];灵芝组线粒体Cyt-C含量[(5.258±1.560)μmol/L]高于模型组,但差异无显著性(P>0.05),胞质Cyt-C含量[(1.727±0.396μmol/L]明显低于模型组(P<0.05),与对照组差异无显著性(P>0.05)。结论:2型糖尿病大鼠附睾细胞钙稳态失衡、线粒体有损伤,附睾细胞可能存在细胞凋亡过度。灵芝孢子粉在糖尿病状态下,对附睾组织有保护作用或有对抗细胞凋亡作用。     

STZ诱导联合高脂饮食及右肾切除糖尿病肾病模型大鼠病程早、中、晚期的界定

目的:探索糖尿病肾病(DN)模型大鼠不同病程阶段(早、中、晚期)的造模时间。方法:采用右肾切除+腹腔注射链脲佐菌素+高脂饮食建立DN大鼠模型(DN模型组),对照组予假手术及普通饲料喂养。观察26周。定期检测大鼠体重、尿微量白蛋白(m Alb)、24 h尿蛋白定量(24 h U-Pr)、血糖、Scr、BUN、肾脏病理等,观察模型大鼠进入DN早、中、晚期的时间。结果:DN模型组大鼠在右肾切除、STZ腹腔注射3天后测尿m Alb升高,24 h U-Pr 30 mg,此时为DN早期阶段(记为0周)。第9周末,DN模型大鼠24 h U-Pr(123. 40±22. 15) mg/24 h,显著高于对照组(9. 05±1. 92) mg/24 h(P 0. 01);电镜下见肾小球GBM增厚(0. 28μm),足细胞结构不清,数目减少,此时进入DN中期阶段。第22周末,DN模型大鼠血BUN(13. 52±1. 26) mmol/L,Scr(73. 42±3. 51)μmol/L,较对照组[BUN(6. 31±1. 44) mmol/L,Scr(39. 25±2. 92)μmol/L]显著升高(P 0. 01)。光镜下见DN大鼠肾小球荒废,毛细血管节段性硬化;电镜下测GBM厚约0. 35μm,足细胞数目明显减少,足突排列紊乱、大片融合。此时进入DN晚期阶段。结论:右肾切除+高脂饲料+STZ腹腔注射3天后大鼠DN造模成功,此时为DN早期。DN成模9周后进入DN中期,22周后进入DN晚期。     

五环三萜类化合物对大鼠慢性肾病的保护作用

目的研究五环三萜类化合物对大鼠慢性肾小球肾炎的保护作用。方法48只SD健康大鼠随机分为正常对照组、阿霉素肾病模型组和五环三萜类化合物(破壁灵芝孢子粉的有效活性成分)治疗组,治疗观察6周后24h尿蛋白测定、血生化检测及病理的变化。结果阿霉素肾病模型组24h尿蛋白测定(82.50±3.18)mg/d及血肌酐(44.75±8.06)μmol/L较正常对照组(9.60±0.57)mg/d及(35.25±2.63)μmol/L明显异常,差异有统计学意义(P<0.05),肾脏病理变化显著;而五环三萜类化合物治疗组24h尿蛋白测定(45.01±3.94)mg/d较模型组(82.50±3.18)mg/d显著改善,差异有统计学意义(P<0.05),肾脏病理变化明显改善。结论应用五环三萜类化合物对大鼠慢性肾病有明显的保护作用。     

棓丙酯对早期糖尿病肾病保护作用机制的实验研究

目的:探讨早期糖尿病肾病肾小球新生血管的特征及其棓丙酯对早期糖尿病肾病肾小球病变的保护作用及可能机制。方法:将30只SD大鼠随机分为3组,模型组与治疗组大鼠应用链脲佐菌素(60mg/kg)一次性腹腔注射建立糖尿病肾病模型,对照组注射相应体积的柠檬酸盐溶液,治疗组给予棓丙酯(2mg.kg-1.d-1)腹腔注射治疗。模型建立8周后PAS染色评价各组肾组织病理变化,观察大鼠24h尿蛋白排泄率与肾组织CD31的IOD变化,运用CD31及PCX标记免疫荧光检测肾小球血管增生程度和结构特点。结果:造模后8周,模型组肾小球增殖血管在结构上可见无足细胞包被的幼稚血管,在肾小球血管增殖方面较对照组显著增加(P<0.01),但在治疗组这种升高被显著抑制(P<0.05);模型组新生血管的程度与白蛋白尿的程度正相关(r=0.62)。结论:早期糖尿病肾病大鼠肾小球内不成熟血管增殖明显,促进早期糖尿病肾病的进展,棓丙酯可抑制肾小球异常血管增殖从而对早期糖尿病肾病发挥保护作用。     

胰岛素降糖治疗对糖尿病肾病大鼠自噬的影响

目的了解自噬在糖尿病肾病大鼠肾小球的表达情况,观察胰岛素降糖治疗对糖尿病肾病大鼠足细胞自噬的影响,探讨自噬在糖尿病肾病进程中的作用。方法选择50只雄性wistar大鼠,适应性喂养1周后随机选10只作为空白对照组(A组),另外40只大鼠进行链脲佐菌素(streptozotocin,STZ)诱导,腹腔注射STZ制备糖尿病动物模型。造模成功后将40只糖尿病大鼠随机分为2组(B组和C组),每组各20只;B组给予等量柠檬酸缓冲液皮下注射,C组每天根据血糖水平给予胰岛素1.5 U/kg皮下注射,连续注射4周。4周后收集24 h血、尿标本查尿素氮、肌酐、血糖,肾脏组织送病理PAS染色观察肾组织病理改变,透射电镜观察肾小球足细胞足突改变,Western blot检测自噬标志物LC3I/H表达。结果与A组相比,B、C组大鼠24 h尿白蛋白、血糖均升高明显(P0.01),PAS染色发现肾小球基膜增厚,系膜区增宽,基质增多,电镜下足细胞足突增宽、融合,自噬活化标志物LC3-Ⅱ/LC3-Ⅰ值明显下降(P0.01)。与B组比,C组大鼠肾小球病理变化有所改善,足细胞和自噬体数量增多,细胞器损伤减轻,LC3-Ⅱ/LC3-Ⅰ值上调(P0.01)。结论糖尿病肾病大鼠肾小球自噬水平降低,胰岛素处理糖尿病肾病大鼠可上调自噬水平,并可减轻肾小球病理改变和足细胞损伤,提示自噬水平增强可能有益于延缓糖尿病肾病进展。     

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.     

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.