腹膜间皮细胞过氧化物酶体增殖物活化受体γ的表达及其配体对CD40和细胞间黏附分子1的影响

目的观察过氧化物酶体增殖物活化受体γ（PPAR-γ）在大鼠腹膜间皮细胞（RPMCs）中的表达以及脂多糖（LPS）的调节作用，并探讨PPAR-γ天然配体15d-PGJ2及人工合成配体ciglitazone对RPMCs表达CD40和ICAM-1的影响。方法分离及培养RPMCs，常规传代及鉴定，取第2代细胞用于实验研究。LPS不同浓度（0．1、1．0、10、50及100μg／ml）、LPS（1μg／ml）处理后不同时间点及15d-PGJ2（3μmol／L）、ciglitazone（10μmol／L）作用细胞36h后收集细胞。RT-PCR检测PPAR-γ、CD40以及ICAM-1 mRNA表达。免疫细胞化学检测PPAR-γ在RPMCs中的分布。Western印迹检测PPAR-γ及ICAM-1蛋白表达。结果（1）常规培养的RPMCs表达一定量PPAR-γ，表达部位主要分布于RPMCs细胞核内，在细胞浆微弱表达。（2）随着LPS浓度逐渐增大，PPAR-γ蛋白表达水平呈逐渐增高的趋势，LPS浓度为10μg／ml时其表达为最高峰。LPS（1μg／ml）作用12h时PPAR-γ蛋白表达最强，PPAR-γ1表达高于PPAR-γ2；之后显著降低，持续至72h。（3）LPS刺激后RPMCs CD40mRNA表达显著增强；15d-PGJ2、ciglitazone显著降低CD40 mRNA表达（P均〈0．01）。（4）LPS刺激后RPMCs ICAM-1蛋白表达显著增加：15d-PGJ2增加LPS介导的ICAM-1 mRNA表达（P〈0.01），但显著抑制ICAM-1蛋白表达（P〈0．05）。ciglitazone对LPS介导的ICAM-1 mRNA和蛋白表达均有显著抑制作用（P均〈0．05）。结论RPMCs结构性表达PPAR-γ。LPS调节PPAR-γ表达呈现先增强后抑制趋势。PPAR-γ配体可显著抑制LPS介导的CD40mRNA和ICAM-1蛋白的表达。提示RPMCs功能性表达PPAR-γ．可能通过负性调节炎症介质分泌而参与腹腔局部防御。     

转化生长因子β1对脂多糖刺激大鼠腹膜间皮细胞上调表达促炎症因子的影响

目的 观察转化生长因子β1（TGF-β1）对脂多糖(LPS)刺激大鼠腹膜间皮细胞上调表达促炎症因子的影响，并探讨其可能的机制。 方法 把原代培养的第2代大鼠腹膜间皮细胞（RPMCs）分成对照组、LPS刺激组（1 mg/L）、TGF-β1刺激组（5 μg/L）及LPS+TGF-β1刺激组。RT-PCR和ELISA方法检测肿瘤坏死因子α（TNF-α）和白细胞介素6（IL-6） mRNA及蛋白的表达。蛋白印迹方法检测磷酸化核因子（p-NF）-κB/NF-κB值的变化。 结果 (1)LPS可刺激RPMCs上调TNF-α和IL-6表达。LPS刺激24 h后，p-NF-κB/NF-κB值升高。(2)TGF-β1可拮抗LPS刺激大鼠腹膜间皮细胞上调TNF-α和IL-6表达，同时，也降低p-NF-κB/NF-κB值。 结论 在体外培养的大鼠腹膜间皮细胞，TGF-β1可拮抗LPS的致炎作用，其作用机制可能是通过抑制NF-κB的活化而介导。     

罗格列酮通过核因子κB抑制脂多糖诱导的大鼠腹膜间皮细胞CD40和胞间黏附分子1的表达

目的 探讨罗格列酮对脂多糖（LPS）诱导的体外培养大鼠腹膜间皮细胞CD40和胞间黏附分子1（ICAM-1）表达的影响以及调节机制。 方法 分离及培养大鼠原代腹膜间皮细胞。将细胞随机分为正常对照组、LPS（5 mg/L）组、BAY11-7085（NF-κB抑制剂）组（5 μmol/L预刺激3 h后加入LPS作用3 h）、不同浓度罗格列酮（过氧化物酶体增殖蛋白激活性受体γ配体）组（10、20 μmol/L分别预处理3 h再加入LPS 5 mg/L）、GW9662（过氧化物酶体增殖蛋白激活性受体γ拮抗剂）预处理组（预处理3 h后加入罗格列酮10 μmol/L,3 h后再加入LPS 5 mg/L）和溶媒对照组。加入LPS后 1 h收集细胞检测核因子κB（NF-κB） p65水平;3 h收集细胞分别检测CD40和ICAM-1基因表达;24 h收集细胞分别检测CD40和ICAM-1蛋白表达。RT-PCR法检测基因表达;Western印迹和免疫荧光方法检测蛋白表达及核因子磷酸化。 结果 （1）常规培养的腹膜间皮细胞表达基础量CD40和ICAM-1,LPS显著上调其表达（P < 0.05）;LPS作用1 h时腹膜间皮细胞磷酸化NF-κB p65活化水平显著增高,与对照组差异有统计学意义 (1.10±0.17比0.55±0.06,P < 0.05)。（2）NF-κB抑制剂BAY11-7085预处理后LPS诱导的磷酸化NF-κB p65水平、CD40 和ICAM-1表达显著低于LPS组（0.22±0.11比1.10±0.17,P < 0.01;0.34±0.02 比 0.50±0.06,P < 0.05;0.35±0.16 比0.74±0.03,P < 0.05）。（3）罗格列酮预处理后,LPS诱导的磷酸化NF-κB p65水平、CD40以及ICAM-1蛋白表达亦显著低于LPS组（0.77±0.08比0.90±0.10,P < 0.01;0.79±0.16 比0.99±0.06,P < 0.05;0.83±0.20比1.22±0.13,P < 0.05）。GW9662和罗格列酮联合预处理后,LPS诱导的磷酸化NF-κB p65水平与罗格列酮预处理组差异无统计学意义,但CD40和ICAM-1表达显著高于罗格列酮预处理组（0.95±0.19比0.79±0.16;1.04±0.24比0.83±0.20,均P < 0.05）。 结论 NF-κB信号通路参与调节LPS诱导的腹膜间皮细胞表达CD40和ICAM-1。罗格列酮通过 NF-κB途径下调CD40和ICAM-1表达,从而发挥抗炎作用。     

细菌毒素和肿瘤坏死因子-α对人腹膜间皮细胞白细胞介素8和纤连蛋白分泌的影响

目的：研究细菌毒素和肿瘤坏死因子（TNF）-α对人腹膜间皮细胞分泌白细胞介素（IL）-8和纤连蛋白（FN）的影响。方法：分离人腹膜间皮细胞（HPMC）做体外培养,采用酶联免疫双抗夹心法和逆转录聚合酶链反应,检测细胞产生IL-8和FN水平的情况。采用Lowry方法检测培养液中细胞内总蛋白。结果：脂多糖（10μg/ml)、金黄色葡萄球菌肠毒素（10μg/ml)和TNF-α（1000U/ml)分别刺激HPMC后,培养液内IL-8和FN蛋白质水平显著增高（P＜0.01),并上调IL-8和FN的mRNA表达。结论：细菌毒素和TNF-α可引起人腹膜间皮细胞IL-8和FN蛋白水平增加,并上调HPMC IL-8和FN mRNA表达;FN合成增加可能是导致腹膜纤维化原因之一。     

肿瘤坏死因子α对人腹膜间皮细胞基质金属蛋白酶及其组织抑制物表达的影响

目的 观察肿瘤坏死因子α（TNF-α）对人腹膜间皮细胞(HPMC) 基质金属蛋白酶（MMP）2、MMP-9及其组织抑制物（TIMP）2、TIMP-1 mRNA和Ⅰ型胶原表达的影响，同时观察TNF-α、TGF-β、IL-1单独或协同作用对HPMC的MMP-9活性的影响。 方法 采用半定量RT-PCR法测定细胞MMP-2、MMP-9、TIMP-2及TIMP-1 mRNA 的表达。采用Biotrak MMP-9 活性检测系统来精确定量测定MMP-9活性及MMP-9原的含量。ELISA法检测Ⅰ型胶原蛋白的表达。 结果 TNF-α(1~10 μg/L)分别刺激HPMC 4、16、24及48 h后， HPMC的MMP-9 mRNA表达显著上调，为基础的2.3～4.9倍（P ＜ 0.05），呈时间依赖性。TNF-α（1 μg/L）作用48 h后显著下调TIMP-1、TIMP-2 mRNA 表达，为基础的77.2％、61.3％（P ＜ 0.05），而MMP-2 mRNA表达没有显著变化。TNF-α+TGF-β１ （1~10 μg/L）、 TNF-α+TGF-β1+IL-1(1~10 μg/L)和TNF-α(5~10 μg/L)刺激HPMC 24 h后，促其分泌MMP-9 的作用最为明显。同时，TNF-α明显上调Ⅰ型胶原蛋白表达（P ＜ 0.05）。 结论 TNF-α 明显上调HPMC的MMP-9 mRNA的表达和MMP-9 的活性；联合其他细胞因子后促MMP-9分泌的作用更明显。TNF-α单独或协同其他因子在腹膜纤维化的过程中可能发挥了重要作用。     

结直肠癌微环境中细胞因子的表达及其与CD16a mRNA表达的相关性研究

目的探讨结直肠癌肿瘤微环境中细胞因子的表达及其与CD16a mRNA表达的关系。方法分别采用实时荧光定量PCR法和流式细胞术微球阵列法(CBA法)检测42例结直肠癌组织及其癌旁组织中CD16a mRNA和8种细胞因子[包括白细胞介素(IL)-2、IL-4、IL-6、IL-10、IL-12、肿瘤坏死因子-α(TNF-α)、γ-干扰素(IFN-γ)和血管内皮生长因子(VEGF)]的表达水平,分析两者之间的相关性。结果结直肠癌组织中IL-6、TNF-α和VEGF的表达水平高于癌旁组织(P<0.05),而IL-2、IL-4、IL-10、IL-12和IFN-γ在2种组织中的表达水平比较差异均无统计学意义(P>0.05)。术前CEA正常组的IL-6和VEGF的表达水平高于术前CEA升高组(P<0.05)。相关性分析结果显示:结直肠癌组中IL-6的相对表达水平与CD16a mRNA的表达水平呈负相关(P<0.05)。结论结直肠癌组织中IL-6、TNF-α和VEGF的表达水平较癌旁组织明显升高,提示促血管生成作用及免疫抑制增强。此外,结直肠癌肿瘤微环境中CD16a mRNA的表达与IL-6的表达呈负相关。     

核因子-κB、细胞间黏附分子-1和炎症细胞因子在急性胰腺炎肝损伤中的作用

目的 观察核因子（NF）-κB、细胞间黏附分子（ICAM）-1和炎症细胞因子在急性胰腺炎（AP）肝损伤中的作用。方法 36只SD大鼠随机分为AP组、假手术组（SO组），通过胰胆管逆行注射3．5％牛磺胆酸钠溶液制作大鼠AP模型。术后3、6、12h胰腺组织光镜检查；肝组织光镜、电镜观察；检测血清丙氨酸氨基转移酶（ALT）；放射免疫法（RIA）测定血清肿瘤坏死因子（TNF）-α、白细胞介素（IL）-1β、IL-6；酶联免疫吸附法（ELISA）检测IL-10；实时定量聚合酶链反应（Real—time PCR）检测肝组织TNF-αmRNA、IL-6mRNA；肝组织Envision法免疫组织化学测定NF-κB、ICAM-1。结果 病理学证实建立AP组，出现肝损伤的病理形态变化；与SO组比较，AP组的血清ALT以及TNF-α、IL-6、IL-1β、IL-10水平显著增高（P〈0．05），其中血TNF-α水平在3h升高、6h达高水平，血IL-6在AP3h明显升高，下降缓慢。AP6、12h组肝NF-κB活化，AP各组间肝NF-κB活性表达差异均有统计学意义（χ^2=15．048，P〈0．05），ICAM-1无表达。AP3～12h内，AP组肝TNF-αmRNA在3h明显升高、6h高表达；AP组的肝IL-6mRNA则在3h已增加、3h后缓慢下降，均显著高于各自时段的SO组（P〈0．05）。结论 AP发生后，肝脏NF-κB活化，可能介导肝TNF-αmRNA、IL-6mRNA的表达来参与肝损伤，ICAM-1对AP早期肝损伤无明显作用。     

白介素4及CD40抗体作用下肾小管上皮细胞钙调神经磷酸酶活性及其与RANTES分泌的关系

目的观察小鼠肾小管上皮细胞(TEC)在白介素4(IL-4)及CD40激活状态下钙调神经磷酸酶(CaN)活性,并进一步探讨其与趋化因子RANTES分泌的关系。方法取Ⅱ级6～7周的雌性DBA小鼠,分离肾小管上皮细胞进行培养、刺激。采用RT-PCR检测RANTESmRNA表达;ELISA检测培养上清中RANTES含量;流式细胞仪检测CD40表达。结果(1)常规培养TEC可表达一定量的CD40;用IL-4刺激TEC24h,细胞表面CD40平均荧光强度(MFI)显著高于对照组(7.92±0.56vs4.33±0.30,P<0.001)。(2)常规培养TEC中有一定量的CaN活化(8.98±0.56)nmol/mg.pro;用IL-4、CD40抗体(mAb)及IL-4 CD40mAb刺激细胞,3组CaN活性均显著高于对照组(P<0.05)。(3)常规培养TEC仅分泌极少量的RANTES;在IL-4刺激或CD40mAb激活后TECRANTES蛋白分泌增高,分别为(43.61±13.73)pg/ml和(73.77±4.28)pg/ml,显著高于对照组(14.78±2.20)pg/ml(P<0.001)。(4)常规培养TEC微量表达RANTESmRNA;用IL-4、CD40mAb及IL-4 CD40mAb刺激细胞24h,各刺激组RANTESmRNA表达显著高于对照组(P<0.05)。(5)在IL-4、CD40mAb及IL-4 CD40mAb刺激下,FK506对TEC分泌RANTES蛋白及mRNA有显著抑制作用(P均<0.05)。结论Th2细胞因子IL-4及CD40-CD40配体(CD40L)共刺激信号可通过活化TECCaN,调控RANTES基因表达及分泌、     

稳定存活肝移植受者血清细胞因子水平的研究

目的 研究稳定存活的肝移植受者血清细胞因子的表达状况及意义。方法ELISA检测22例原位肝移植患者、13例原发性肝癌患者及12例正常人血清细胞因子的表达情况。流式细胞术分析外周血T细胞表型。结果外周血CD3^ 、CD8^ T细胞百分比以及CD4^ ／CD8^ 比值,各组间比较无统计学差异。肝移植组CD3^ CD25^ T细胞百分比高于正常人组(P=0．022)。血清IL-2、IFN-γ、IL-10、IL-4及INF-α水平,各组间比较差异无显著性。IL-6、ICAM-1和P-seleetin水平肝移植组显著高于正常人组(P值分别为0．048、0．000和0．025)。结论稳定存活的肝移植患者体内效应T细胞仍处于低活化状态,炎症性细胞因子(TNF-α、IL-6)和黏附分子(ICAM-1、P-Seleetin)可能在移植物的慢性损伤过程中发挥了作用。     

T细胞免疫球蛋白及黏蛋白家族-3对干扰素-γ活化的小鼠肝Kupffer细胞分泌炎性细胞因子的调节作用及机制

目的探讨T细胞免疫球蛋白及黏蛋白家族-3(Tim3)对IFN-γ活化的小鼠Kupffer细胞的调节作用并探讨其相关机制。方法将真核表达质粒pc DNA3.1-Tim3转染小鼠肝Kupffer细胞,以Real-time PCR和Western blot检测Tim3在小鼠肝Kupffer细胞的表达。通过ELISA检测质粒pc DNA3.1-Tim3、Tim3阻断型抗体对IFN-γ活化的小鼠肝Kupffer细胞因子(TNF-α、IL-1β和IL-6)产生的影响,Western blot检测JAK2/STATl蛋白表达。结果 Real-time PCR检测结果显示,IFN-γ能够显著提高小鼠肝脏Kupffer细胞中Tim3 m RNA的表达水平(P0.05);pc DNA3.1-Tim3组的TNF-α、IL-6和IL-1β分泌较对照组显著下降(P0.01);ELISA结果显示,Tim3阻断型抗体组与对照组相比,TNF-α、IL-6和IL-1β的分泌增加(P0.01);Western blot检测显示,与对照组相比,Tim3阻断型抗体预处理的小鼠Kupffer细胞JAK2及STAT1蛋白的表达上调(P0.05)。结论Tim3通过调控Jak2/Stat1蛋白表达参与了Kupffer细胞活化的调节。     

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.