参附注射液对大鼠胰腺移植受体小肠肠粘膜屏障的保护作用

目的探讨参附注射液(SF)对大鼠胰腺移植受体肠粘膜屏障的保护作用及机制。方法24只糖尿病大鼠随机分为缺血再灌注组(IR组,n=12),参附注射液预处理组(SF组,n=12),12只正常大鼠为对照组,IR组和SF组大鼠均接受胰腺移植,再灌注后5d检测小肠通透性和吸收功能,检测血清TNF-α、NO、SOD和淀粉酶活性,取受体空肠粘膜组织检测小肠粘膜粘膜湿重、微绒毛高度及宽度、MDA含量及MPO活性,同时取肠系膜静脉血、肠系膜淋巴结、肝及脾组织进行细菌培养,观察细菌易位情况。结果再灌注后SF组血清TNF-α含量(P<0.01)、淀粉酶活性(P<0.01)、MDA含量(P<0.01)、MPO活性(P<0.01)、小肠通透性(P<0.01)、细菌易位率(P<0.01)和小肠粘膜损伤程度均低于IR组;血清NO和SOD含量、小肠吸收功能均高于IR组(P<0.01)。结论SF预处理可保护大鼠胰腺移植受体小肠肠粘膜屏障,降低细菌易位率,机制可能与降低胰酶活性、减少TNF-α生成、减轻PMNs粘附与聚集、增加NO和SOD含量有关。     

参附对再灌注期间肠粘膜上皮细胞凋亡的抑制作用及机制探讨

目的　探讨大鼠缺血 再灌注期间粘膜上皮细胞凋亡及参附注射液对其影响的可能机制。方法　采用大鼠肠缺血 再灌注模型 ,2 4只大鼠随机分为对照组 (C组 )、缺血 再灌注组 (I R组 )和参附治疗组 (SF组 )。在规定时间检测回肠粘膜上皮细胞Caspase 3、Bcl 2蛋白的表达、凋亡细胞数目及回肠粘膜组织肿瘤坏死因子 (TNF α)水平 ,同时观察病理形态学改变。结果　 (1)I R组凋亡细胞显著增多 ,SF组凋亡细胞数较I R组显著减少而多于C组 (P <0 0 5 )。 (2 )Caspase 3在I R组的表达显著高于SF组和C组 (P <0 0 1) ,SF组与C组差异无显著性。Caspase 3表达与凋亡细胞数目呈正相关 (r =0 914 9,P <0 0 1) ;Bcl 2的表达与Caspase 3的表达呈直线负相关 (r =- 0 9384 ,P <0 0 1)。 (3)TNF α表达 :TNF α的表达在I R组显著高于C组和SF组 (均P <0 0 1) ,SF组与C组差异无显著性。TNF α表达与凋亡细胞数目呈正相关 (r =0 9133,P <0 0 1)。 (4)SF组小肠粘膜病理损伤程度明显小于I R组 (P <0 0 1)。结论　参附注射液通过抑制TNF α、Caspase 3表达同时上调Bcl 2而抑制缺血 再灌注期间肠粘膜上皮细胞的凋亡 ,从而减轻肠粘膜缺血 再灌注损伤。     

参附注射液对大鼠心肌缺血再灌注损伤的保护作用

目的探讨参附注射液对大鼠心肌缺血再灌注损伤保护作用的机制。方法健康雄性 SD大鼠24,只,随机分为3组(n=8):假手术组(Sham组)、缺血再灌注组(I／R组)、参附处理组(SF 组)。Sham组丝线穿过冠状动脉前降支但不结扎,I／R、SF组通过结扎心脏左冠状动脉前降支30 min, 再灌注60 min制作缺血再灌注损伤动物模型。缺血前30 min,SF组经腹腔注射参附注射液10 ml／kg, 其余两组注射等量生理盐水。于再灌注末通过右颈动脉置管取血,采用酶联免疫吸附法测定血浆肿 瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)浓度,电镜下观察缺血区心肌超微结构变化。结果 与 Sham组比较,I／R组血浆TNF-α、IL-6浓度升高,SF组血浆IL-6浓度升高(P<0．01)。与I／R组比较,SF 组血浆TNF-α、IL-6浓度降低(P<0．01)。I／R组心肌超微结构明显受损,SF组受损较轻。结论参附 注射液可通过降低大鼠全身炎症反应减轻心肌缺血再灌注损伤。     

大鼠肠道缺血再灌注后肠粘膜损伤与防御素-5 mRNA变化

目的探讨大鼠肠道缺血再灌注后肠粘膜损伤与大鼠防御素5(rat defensin-5,RD-5)mRNA变化。方法采用夹闭肠系膜上动脉(SMA)方法制造大鼠肠道缺血再灌注模型,大鼠分为假手术组、实验组,在缺血再灌注后1h、6h、12h及24h观测肠粘膜形态变化,检测肿瘤坏死因子-α(TNF-α)、白介素-6(IL-6)含量及大鼠防御素5(RD-5)mRNA的动态变化。结果形态学观察显示实验组缺血再灌注后肠粘膜呈不同程度的损害状态,损伤评分较假手术组高;实验组TNF-α、IL-6含量明显升高,12小时达高峰,均较假手术组高,并有统计学意义;大鼠防御素5(RD-5)mRNA在缺血再灌注后明显升高,再灌注后1小时到达高峰,随后逐渐下降,但均高于假手术组。结论肠道缺血再灌注对肠道粘膜造成损伤,肠道防御素5参与人肠粘膜的损伤与抗损伤过程。     

参附注射液对大鼠移植肝脏缺血再灌注损伤的影响

目的探讨参附注射液(Shenfuinjection,SF)对大鼠移植肝脏缺血再灌注损伤的保护作用及机制。方法采用雄性SpragueDawley(SD)大鼠同种异体原位肝移植模型,60只SD大鼠随机平均分成对照组和SF处理组,移植肝脏再灌注3、6、24h取血及肝脏组织检测。结果SF组血清超氧化物歧化酶(SOD)和一氧化氮(NO)水平明显高于对照组(P<0·05),丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、乳酸脱氢酶(LDH)、透明质酸(HA)、丙二醛(MDA)、肿瘤坏死因子α(TNF-α)、白介素1(IL-1)、内皮素1(ET-1)水平和肝脏细胞凋亡指数明显低于对照组(P<0·05),肝脏组织形态学改变也轻于对照组。结论参附注射液对移植肝脏缺血再灌注损伤具有防治作用,可能的机制包括抑制枯否细胞激活和氧自由基产生,改善微循环,减少细胞凋亡。     

色甘酸钠对大鼠肠缺血再灌注损伤的作用

目的 探讨肥大细胞膜稳定剂色甘酸钠对大鼠肠缺血再灌注损伤的作用。方法 32只SD大鼠随机分为4组（n=8）：假手术组（S组）、缺血再灌注组（I/R组）、缺血再灌注＋色甘酸钠25 mg/kg组（C1组）及缺血再灌注＋色甘酸钠50 mg/kg组（C2组）。采用肠缺血45 min再灌注1h制备肠缺血再灌注损伤模型,C1组、C2组再灌注前15min腹腔注射色甘酸钠。再灌注1h后,取小肠组织,光镜下观察小肠粘膜病理学改变,进行Chiu评分,电镜下观察小肠粘膜的超微结构,测定小肠肿瘤坏死因子-α（TNF-α）及组胺含量,进行肠粘膜肥大细胞（IMMC）计数,并测定类胰蛋白酶表达。结果 肠缺血再灌注导致小肠Chiu评分、TNF-α含量、IMMC计数及类胰蛋白酶表达增加,组胺含量降低,IMMC出现胞浆颗粒明显减少,颗粒包膜相互融合形成细胞内空泡等脱颗粒现象;色甘酸钠25、50mg/kg可减弱肠缺血再灌注导致的上述改变,且50mg/kg的作用更明显。Chiu评分与TNF-α、组胺、类胰蛋白酶水平有相关性,相关系数分别为0．532、-0．770（P＜0．05）。结论 色甘酸钠25、50mg/kg可抑制IMMC活性,减少TNF-α的释放,从而减轻了大鼠肠缺血再灌注损伤;色甘酸钠50mg/kg的效果较好。     

缺血预处理-后处理对大鼠肠缺血再灌注损伤的影响

目的 评价缺血预处理.后处理对大鼠肠缺血再灌注损伤的影响.方法 清洁级成年雄性SD大鼠40只.体重225～275 g,随机分为5组(n=8):假手术组(S组)仅分离肠系膜上动脉(SMA),不夹闭;肠缺血再灌注组(IIR组)采用夹闭SMA 60 min,再灌注60 min的方法制备肠缺血再灌注损伤模型;缺血预处理组(IPr组)夹闭SMA 10 min,再灌注10 min,余同IIR组;缺血后处理组(IPo 组)夹闭SMA 60 min后,再灌注30 s,缺血30 s,反复3次,再灌注60 min;缺血预处理.后处理组(IPr-IPo组)先行缺血预处理,再行缺血后处理,操作过程同IPr组和IPo组.于再灌注60 min时各组取肠粘膜组织,观察肠粘膜形态并行Chiu评分,检测丙二醛(MDA)含量,超氧化物歧化酶(SOD)及髓过氧化物酶(MPO)活性,同时采集动脉血样检测血浆肿瘤坏死因子α(TNF-α)及白细胞介素6(IL-6)浓度.结果 与S组比较,其余各组Chiu评分、MDA含量、MPO活性、血浆TNF-α与IL-6浓度升高,SOD活性降低(P<0.05).与IIR组比较,IPr组、IPo组及IPr-IPo组Chiu评分、MDA含量、MPO活性、血浆TNF-α和IL-6浓度降低.SOD活性升高(P<0.01).与IPr组和IPo组比较,IPr-IPo组Chiu评分和MDA含量降低,SOD活性升高(P<0.05).IPr组与IPo组各指标比较差异无统计学意义(P>0.05).结论 缺血预处理-后处理可减轻大鼠肠缺血再灌注损伤,较单独应用时效果好.     

参附注射液对大鼠肠缺血再灌注损伤后肠黏膜细胞凋亡的影响

目的：研究参附注射液对大鼠肠缺血再灌注期间黏膜上皮细胞凋亡的影响，并探讨其可能机制。方法：采用大鼠肠缺血再灌注模型。24只大鼠随机分为假手术对照组（C组）、缺血再灌注组（I／R组）和参附治疗组（SF组），在规定时间检测小肠黏膜上皮细胞caspase-3、Bcl-2蛋白的表达，凋亡细胞数目，同时观察小肠黏膜病理形态学改变。结果：IR组肠黏膜上皮细胞凋亡指数（apoptosisindex,AI）、caspase-3、Bcl-2蛋白显著高于C组（P〈0．01）。SF组AI、caspase-3蛋白低于IR组（P〈0.01或P〈0．05），而Bcl-2蛋白较IR组上调（P〈0．01）。caspase-3表达与AI呈正相关（r=0，914，P〈0，01）；Bel-2的表达与AI、caspase-3呈直线负相关（r分别=-0．375，-0．367，P〈001）。SF组小肠黏膜病理损伤程度较I／R组明显减轻（P〈0.01）。结论：参附注射液通过抑制caspase-3表达和促进Bcl-2基因表达减少缺血再灌注期间肠黏膜上皮细胞的凋亡。从而一定程度上减轻肠黏膜缺血再灌注损伤。     

参附注射液对大鼠胰腺移植受体小肠肠粘膜屏障的保护作用

目的探讨参附注射液（SF）对大鼠胰腺移植受体肠粘膜屏障的保护作用及机制。方法24只糖尿病大鼠随机分为缺血再灌注组（IR组。n=12），参附注射液预处理组（SF组．n=12），12只正常大鼠为对照组，IR组和SF组大鼠均接受胰腺移植，再灌注后5d检测小肠通透性和吸收功能，检测血清TNF-α、NO、SOD和淀粉酶活性，取受体空肠粘膜组织检测小肠粘膜粘膜湿重、微绒毛高度及宽度、MDA含量及MPO活性，同时取肠系膜静脉血、肠系膜淋巴结、肝及脾组织进行细菌培养，观察细菌易位情况。结果再灌注后SF组血清TNF—α含量（P〈0．01）、淀粉酶活性（P〈0．01）、MDA含量（P〈0．01）、MPO活性（P〈0．01）、小肠通透性（P〈0．01）、细菌易位率（P〈0．01）和小肠粘膜损伤程度均低于IR组；血清NO和SOD含量、小肠吸收功能均高于IR组（P〈0．01）。结论SF预处理可保护大鼠胰腺移植受体小肠肠粘膜屏障，降低细菌易位率，机制可能与降低胰酶活性、减少TNF—α生成、减轻PMNs粘附与聚集、增加NO和SOD含量有关。     

蛇床子素预处理对肾脏缺血再灌注损伤炎症因子表达的影响

目的:探讨肾脏缺血再灌注损伤时致炎症因子TNF-α、IL-8、IL-6的表达及蛇床子素对其的保护作用及机制。方法:建立大鼠肾脏缺血再灌注损伤模型。我们随机将30只大鼠分为3组,假手术组(Sham)、缺血再灌注损伤组(IRI)、蛇床子素干预组(Osthole),收集各组血液和肾脏标本,分析肾功能和组织学变化。采用RT-PCR和ELISA分析肾组织和血液TNF-α、IL-8、IL-6的表达。结果:与IR组相比,Osthole预处理组显著改善了肾功能和肾脏组织学变化,以及由IR损伤导致的TNF-α、IL-8、IL-6的表达(P<0.05)。结论:蛇床子可以通过抑制炎症保护肾脏缺血再灌注损伤,蛇床子素可能是一种防治缺血再灌注损伤的新的治疗措施。     

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 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.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

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.