限制性液体复苏对失血性休克大鼠网状内皮系统的影响

目的探讨限制性液体复苏对失血性休克大鼠网状内皮系统的影响。方法60只SD大鼠制成未控制性重度失血性休克模型,随机分成对照组、NF组(无液体复苏组)、NS40组(限制性液体复苏组)和NS80组(常规大量液体复苏组),检测和比较休克复苏后各组存活大鼠肝脏枯否细胞和腹腔巨噬细胞的吞噬功能。结果重度失血性休克大鼠失血后150min存活率NF组、NS40组和NS80组比对照组明显提高,NS40组较NS80组显著改善(P0.05);NS40组大鼠肝脏枯否细胞和腹腔巨噬细胞的吞噬功能较NS80组明显改善(P0.05)。结论限制性液体复苏可以显著改善失血性休克大鼠的网状内皮系统的吞噬功能,提高大鼠的免疫功能,降低死亡率。     

梗阻性黄疸大鼠腹腔巨噬细胞凋亡和吞噬功能的改变

目的　探讨梗阻性黄疸大鼠腹腔巨噬细胞功能的改变。方法　将 66只成年Wistar大鼠随机分为正常 (A)组、假手术 (B)组和胆总管结扎 (CBDL ,C)组 ,每组术后又分为 1、3、7、10、14d五个时相点 ;应用流式细胞术检测两组腹腔巨噬细胞 (PMs)的凋亡、吞噬凋亡细胞及主要组织相容性复合物 (MHC)Ⅱ表达能力的变化。结果　C组大鼠术后各时相点PMs的凋亡指数 (AI)显著增高、吞噬能力和MHCⅡ (I A)类抗原表达能力下降 ,与A组和B组均有明显差异 (P <0 .0 1) ,且C组各时相点PMs的AI与吞噬能力和MHCⅡ类抗原表达能力改变有明显相关性。结论　CBDL大鼠PMs的AI明显增高 ,吞噬能力和MHCⅡ类抗原表达能力降低 ,可能导致梗阻性黄疸机体免疫机能的紊乱。     

地塞米松治疗急性坏死性胰腺炎的实验研究

目的探讨地塞米松治疗急性坏死性胰腺炎(ANP)的机理.方法经胰胆管逆行注射牛磺胆酸钠法诱导SD大鼠ANP,治疗组(n=24)模型诱导30 min后注射地塞米松0.2 mg/100 g鼠重,对照组(n=24)注射等量生理盐水,两组分别于4 h和12 h各处死8只鼠测血清肿瘤坏死因子α(TNFα)、淀粉酶,并行胰腺坏死程度评分、检测胰腺腺胞细胞凋亡,余下8只鼠作生存期观察.结果治疗组4 h、12 h TNFα分别为(17.8±2.7) pg/ml和(8.5±1.6) pg/ml,胰腺腺胞细胞凋亡指数分别为(36.94±4.12)%和(32.79±3.31)%,生存时间为(33.4±21.5) h; 对照组上述各项指标依次为(53.6±18.7) pg/ml和(37.2±11.1) pg/ml (P<0.01)、(4.37±1.24)%和(5.12±2.11)%(P<0.01)及(14.6±5.7) h (P<0.01),两组胰腺坏死程度评分差异有显著性意义(P<0.01).结论地塞米松能通过抑制TNFα调控细胞凋亡,细胞凋亡对胰腺具有保护作用.     

尼美舒利对二甲基苯并蒽诱导的乳腺癌的影响及机制的实验研究

目的探讨选择性环氧化酶-2(COX-2)抑制剂尼美舒利(NIM)对二甲基苯并蒽(DMBA)诱导的大鼠乳腺癌的影响及其作用机制。方法将76只大鼠随机分为致癌组(30只)、NIM组(30只)、饮食对照组(8只)及NIM药物对照组(8只),观察乳腺肿瘤诱发率。通过逆转录聚合酶链反应方法、蛋白印迹法测定每组肿瘤组织中COX-2mRNA含量及其蛋白表达水平;放射免疫法测定各组大鼠血浆、肿瘤组织中前列腺素E2(PGE2)含量;TUNEL法、增殖细胞核抗原分别检测凋亡和增殖指数。结果NIM组(40.3%)大鼠乳腺肿瘤发生率明显低于致癌组(69.2%);NIM组COX-2mRNA、蛋白水平较致癌组明显下调[A值:(0.21±0.05)vs.(0.46±0.12),P<0.05;(30.26±8.75)vs.(58.13±10.02),P<0.05],血浆、肿瘤组织中PGE2的含量显著降低[(233±59)pg/mlvs.(452±82)pg/ml,P<0.01;(167±42)pg/mg蛋白vs.(250±67)pg/mg蛋白,P<0.05];NIM组肿瘤细胞的增殖指数与致癌组相比下降[(20±5)vs.(36±5),P<0.01],凋亡指数明显增高[(43±13)vs.(18±7),P<0.01],差异有统计学意义。结论NIM通过下调COX-2的表达,抑制前列腺素的合成,抑制肿瘤细胞的增殖、诱导凋亡,降低DMBA诱发大鼠乳腺癌的发生率。     

雌激素诱导外周血间充质干细胞动员和归巢促进失血性休克大鼠创面愈合的作用

目的:观察雌激素动员外周血间充质干细胞归巢对失血性休克大鼠皮肤创面愈合的影响.方法:制备失血性休克SD大鼠模型,在其背部正中线两侧各制作一个全层皮肤缺损创面(直径2 cm).96只大鼠随机分为4组:假手术对照组(予动、静脉插管但不放血、不补液)、失血性休克组(失血性休克模型大鼠以2:1的乳酸林格液和羟乙基淀粉行常规液体复苏)、雌激素低剂量组(给予失血性休克大鼠雌激素0.2 mg/kg+常规液体复苏)、雌激素高剂量组(给予失血性休克大鼠雌激素0.5 mg/kg+常规液体复苏).观察不同时相点各组动物皮肤创面愈合程度、愈合时间、组织血流量、ATP酶活性以及间充质干细胞动员、归巢情况.结果:与假手术对照组相比,失血性休克大鼠皮肤创面愈合缓慢,在第4天、第8天愈合率分别为(15.40±0 0 1)％、(36.80±1.25)％(P＜0.05),组织血流量及ATP酶活性明显降低(P＜0.01).雌激素能明显促进皮肤创面的愈合,显著改善组织血流量,增强ATP酶活性,增加受损皮肤组织和血液中间充质干细胞的数量.与失血性休克大鼠相比,低剂量雌激素组第4天、第8天皮肤创面愈合率分别为(22.10±0.01)％、(46.40±1.25)％,其外周血及受损皮肤组织中间充质干细胞数量明显增多,同假手术组第4天创面愈合率[(37.10±4.32)％]、第8天创面愈合率[(67.70±1.79)％]相比,愈合仍较为缓慢(P＜0.05);高剂量雌激素具有更好的促创面愈合效果,其第4天、8天创面愈合率分别为(28.40±0.12)％、(57.30±2.01)％(P＜0.05),且间充质干细胞在皮肤创面及外周血中增多更为显著.失血性休克组创面完全愈合时间[(23.98±1.56) d]较假手术对照组[(14.98±1.21)d]显著延长(P＜0.01),高剂量雌激素组(16.87±1.56)d和低剂量雌激素组[(22.67±1.78)d]创面愈合时间明显缩短(P＜0.05),且高剂量雌激素组创面愈合时间最短.结论:雌激素可动员间充质干细胞归巢,促进失血性休克大鼠创面愈合.     

CO2气腹对荷瘤大鼠IL-1β、IL-6和腹膜巨噬细胞功能的影响

目的采用种植性大鼠肝脏肿瘤模型观察CO2气腹对细胞因子和腹膜巨噬细胞功能的影响.方法荷瘤大鼠32只随机分为4组(n=8)对照组(仅麻醉)、开腹组、免气腹组和CO2气腹组.术后2、24 h收集血清,检测血清中的IL-1β、IL-6水平;术后48 h,收集培养腹膜巨噬细胞,检测巨噬细胞产生的TNF-α水平.结果术后2、24 h开腹组IL-6的水平分别为(57.92±2.06)pg/ml,(35.49±1.15)pg/ml,显著高于CO2气腹组(14.64±0.34)pg/ml,(15.39±0.86)pg/ml,免气腹组(24.75±1.53)pg/ml,(17.10±0.97)pg/ml和对照组(17.75±1.60)pg/ml,(14.55±0.25)pg/ml(P＜0.05).术后2 h开腹组IL-1β的水平为(92.63±4.81)pg/ml,显著高于CO2气腹组(57.94±4.46)pg/ml、免气腹组(58.48±3.20)pg/ml和对照组(58.99±2.30)pg/ml(P＜0.05).CO2气腹组腹膜巨噬细胞产生的TNF-α水平为(35.69±3.54)pg/ml,显著低于免气腹组(68.87±4.08)pg/ml、开腹组(82.96±5.39)pg/ml和对照组(66.45±7.96)pg/ml(P＜0.05).结论腹腔镜术后机体应激反应较小,CO2气腹可能抑制腹膜巨噬细胞的功能.     

严重烧伤早期大鼠中性粒细胞、巨噬细胞凋亡实验研究

目的探讨严重烧伤后中性粒细胞(PMN)凋亡及烧伤血清刺激后PMN、巨噬细胞(Mφ)凋亡,以及巨噬细胞吞噬凋亡PMN的变化.方法选用Ⅲ度30%TBSA烧伤大鼠模型,收集伤后0、6、12、24hPMN,分离伤后24h烧伤血清,应用流式细胞技术检测PMN凋亡百分率;同时收集大鼠腹腔巨噬细胞,检测烧伤血清对Mφ凋亡变化的影响及烧伤后24h大鼠腹腔Mφ对凋亡PMN吞噬能力.结果伤后大鼠PMN凋亡百分率明显降低,伤后6、12、24h各时相点无显著差异.烧伤大鼠血清刺激24h后,PMN凋亡百分率为(15.4±1.2)%,较正常大鼠血清刺激后(50.6±3.9)%显著降低;而Mφ凋亡百分率为(23.2±2.1)%,较正常大鼠血清刺激后(¨.5±1.6)%增多;严重烧伤后大鼠腹腔Mφ对凋亡PMN吞噬能力由(35.0±2.6)%降至(21.8±2.1)%.结论严重烧伤后及在烧伤血清刺激下大鼠PMN凋亡延迟,Mφ吞噬凋亡PMN能力降低,可能凋亡的PMN被Mφ吞噬不完全,最终坏死,释放毒性内容物,是引发SIRS的重要因素之一.     

营养性肥胖对青春期雄性大鼠睾丸生精细胞凋亡的影响

目的:探讨营养性肥胖对青春期雄性大鼠睾丸生精细胞凋亡的影响。方法:健康雄性W istar大鼠40只,随机分为两组,每组20只,对照组给予普通饲料喂养,高脂组用高脂、高热量饲料喂养建立营养性肥胖大鼠模型,10周末处死大鼠摘取睾丸。全自动生化分析仪(ACA)检测外周血总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C);光镜观察睾丸组织病理学改变;TUNEL检测睾丸组织凋亡细胞;免疫组化法检测Bc l-2和Bax蛋白的分布和表达;RT-PCR法检测睾丸组织Bc l-2 mRNA和Bax mRNA的表达。结果:高脂组TC、TG、HDL-C和LDL-C(5.17±0.17、1.18±0.09、1.76±0.11、5.08±0.18)较对照组(1.38±0.12、0.39±0.05、0.97±0.07、0.75±0.06)显著升高(P<0.05);高脂组生精细胞凋亡指数(37.17±2.74)较对照组(5.16±0.81)显著升高(P<0.01),凋亡细胞以精原细胞和精母细胞为主;高脂组Bax蛋白和Bax mRNA(153.26±8.74、1.08±0.12)表达较对照组(101.81±6.14、0.37±0.04)明显升高(P<0.01);高脂组Bc l-2蛋白和Bc l-2 mRNA(139.26±7.21、0.46±0.05)表达较对照组(159.37±8.96、1.05±0.11)明显降低(P<0.01)。结论:营养性肥胖诱导大鼠睾丸生精细胞凋亡增多,其机制可能与Bc l-2表达降低和Bax表达升高相关。     

严重烧伤大鼠肾脏细胞凋亡及其机制的研究

目的探讨严重烧伤大鼠肾脏细胞凋亡的分子机制。方法将50只雄性Wistar大鼠随机分为烧伤组和对照组,每组25只。烧伤组造成30％TBSAⅢ度烫伤(以下称烧伤),伤后创面涂碘伏抗感染,并于伤后6 h抽取大鼠静脉血后处死,留取肾脏标本。对照组除不烫伤外,其余处理同烧伤组。采用原位缺口末端标记法检测两组大鼠肾脏细胞凋亡率。流式细胞术检测肾脏细胞中肿瘤坏死因子相关的凋亡诱导配体(TRAIL)各受体的mRNA及蛋白表达水平。同时检测大鼠血浆尿素氮(BUN)、肌酐(Cr)含量。结果烧伤组大鼠肾脏细胞的凋亡率为(32．4±1．1)％,明显高于对照组[(1．0±0．6)％,P<0．05];而大鼠肾脏组织中TRAIL诱骗受体DcR1的mRNA及蛋白表达水平显著低于正常对照组(P<0．05)。伤后6 h,烧伤组大鼠BUN值[(13．3±2．0)nmol/L]及Cr值 [(76．4±2．0)μmol/L]均明显高于对照组[(5．2±0．7)mmol/L、(40．2±2．8)μmol/L,P<0．05]。结论 TRAIL凋亡通路可能参与介导了严重烧伤大鼠肾脏细胞的凋亡。     

氯化钆对内毒素刺激后小鼠巨噬细胞Toll样受体表达的影响

目的观察氯化钆(GdCl3)对内毒素刺激后的小鼠巨噬细胞来源的细胞系RAW264.7细胞Toll样受体(TLRs)表达的影响。方法RAW264.7细胞分为空白组、内毒素处理组(LPS组)及GdCl3处理组(GdCl3组),采用流式细胞仪检测TLR2/4蛋白表达情况;用逆转录PCR(RT-PCR)法分析细胞中TLR2/4mRNA表达的变化;用ELISA检测细胞培养上清液中TNF-α的水平。结果与LPS组相比,不同浓度的GdCl3作用于RAW264.7细胞后,其TLR2/4蛋白和基因的表达以及TNF-α的表达水平均明显下降,在观察浓度范围内以2000μmol/L时最明显,TLR2/4蛋白:200μmol/L时为(70.2±1.28)%/(66.7±2.59)%,400μmol/L时为(64.9±1.43)%/(60.4±1.25)%,2000μmol/L时为(47.4±0.98)%/(32.1±0.74)%,其与LPS组的(94.4±1.76)%/(95.7±0.87)%比较,P<0.01;TLR2/4mRNA(A值):200μmol/L时为(76.42±2.76)/(101.72±3.14),400μmol/L时为(75.60±3.76)/(89.65±5.17),2000μmol/L时为(64.22±4.67)/(78.44±4.88),其与LPS组的(127.64±3.25)/(119.82±5.59)比较,P<0.05,P<0.01;TNF-α:200μmol/L时为(2540±77)pg/ml,400μmol/L时为(2041±106)pg/ml,2000μmol/L时为(1020±220)pg/ml,其与LPS组的(4688±127)pg/ml比较,P<0.01。结论GdCl3能明显抑制内毒素引起的RAW264.7细胞Toll样受体的表达及相应炎症因子的生成。     

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.     

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.     

Immunomodulation in Transplantation with Photopheresis

Abstract: Photopheresis is a technique in which peripheral blood mononuclear cells, in the presence of a photoacti-vatable compound, are exposed extracorporeally to ultraviolet A light and reinfused, inducing a host autoregula-tory immune response. Experimental work and ongoing clinical studies are helping to define the role of this novel, safe, and non-toxic immunomodulating technology in the field of transplantation.