肾移植患者胆固醇酯转运蛋白基因多态性与脂代谢的关系

目的 探讨肾移植患者胆固醇酯转运蛋白(CETP)基因多态性与脂代谢的关系。方法 生物化学方法检测肾移植患者移植前及移植后6～8个月时的血脂水平；多聚酶链反应-限制性片断长度(PCR-RFLP)方法检测CETP内含子1TaqⅠB与内含子8MSPⅠ位点基因多态性。结果肾移植患者移植前甘油三脂(TG)水平显著高于正常对照组，血清总胆固醇(TC)、高密度脂蛋白胆固醇(HDLC)、低密度脂蛋白胆固醇(LDLC)、脂蛋白(a)[Lp(a)]水平均显著低于正常对照组；移植后TC、TG、HDLC、LDLC、载脂蛋白(ApoB、ApoE)水平均显著高于对照组及移植前水平。肾移植患者CETP TaqⅠB与MSPⅠ位点基因型及等位基因频率的发生率与正常对照组差异无显著性。CETP TaqⅠB基因型为B1/B1的肾移植患者，移植前TG、ApoB水平显著增高，HDLC水平显著降低，移植后表现为TG水平显著增高。肾移植患者CETPMSPI位点不同的基因型间血脂水平差异无显著性。结论肾移植患者易发生高脂血症。CETP内含子TaqⅠB位点基因多态性可显著性影响肾移植患者TG水平，基因型为B1/B1的患者易发生高甘油三酯血症。     

肾移植患者低密度脂蛋白受体TaqⅠ位点基因多态性及血脂水平检测

目的 探讨肾移植患者脂代谢紊乱的一般特征及低密度指蛋白受体（LDLR）TaqⅠ基因多态性对血脂水平的影响。方法 选择105例肾移植患者为病例组，60例血脂正常的健康人作为对照。检测空腹血清总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白胆固醇（LDLC）、高密度脂蛋白胆固醇（DLC）、载脂蛋白及脂蛋白（a）[Lp(a)]水平。采用聚合酶链反应－限制性长度片段多态性方法检测LDLR TaqⅠ基因多态性。结果 病例组于移植后3个月血脂水平即显著增高，于移植后6个月及1年时进一步升高；移植前血清TC、TG高于正常者仅占2.9%和7.6%，移植后3个月增高至28.6%和46.7%（P＜0.01）。移植后6个月升高至40.0%和59.0%，1年时升高至42.9%和62.9%，较3个月时显著升高（P＜0.05）。以TaqⅠ＋／－型人数最多，TaqⅠ＋／＋型最少；对照组Taq基因型分布与病例组的差异无显著性（P＞0.05）；不同基因型的受者血脂水平有所不同，多数指标依TaqⅠ－／－、TaqⅠ /-和TaqⅠ / 顺序递减；对照组因LDLR TaqⅠ基因型的不同，血清TC、LDLC水平的差异具有显著性，病例组除TC和LDLC外，TG、HDLC和Lp(a)的差异也有显著性。结论 肾移植术后易发生脂代谢紊乱，等位基因LDLR TaqⅠ是代谢紊乱发生的危险因子。     

血液透析患者低密度脂蛋白受体相关蛋白基因多态性与血脂水平检测

目的 探讨血液透析患者脂代谢紊乱的临床特征及低密度脂蛋白受体相关蛋白(LRP)基因多态性对脂代谢的影响。方法 生化方法检测血液透析血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDLC)、低密度脂蛋白胆固醇(LDLC)、载脂蛋白(Apo)A1、ApoB、ApoE及脂蛋白(Lp)(a)水平，多聚合酶链反应-限制性片断长度(PCR-RFLP)方法检测LRP5′端四核苷酸重复序列及外显子3 RsaⅠ位点基因多态性。结果 血液透析患者脂代谢紊乱主要表现为血清TG水平显著增高，高于正常者33．0％，HDLC水平显著降低，低于正常者10．4％。偏相关回归分析显示，TG水平与血清ALB水平、透析时体外循环血流量显著相关；HDLC与KT／V显著相关。血液透析患者高血压的发生率为73．6％，心血管疾病发生率为25．0％。伴心血管疾病组TG水平显著高于无心血管疾病组，伴高血压组与无高血压组血脂水平无显著差异。LRP基因多态性分析显示，LRP 5′端基因型91／91、91／187与等位基因91bp频率较高，LRP外显子3基因型C/C与等位基因C发生频率较高，病例组与对照组间无显著差异。病例组LRP5′端四核苷酸重复序列与外显子3 RsaⅠ位点不同基因型间血脂水平无显著差异。结论 血液透析患者脂代谢紊乱主要表现为血清TG、ApoB水平显著增高，HDLC等指标显著降低。伴心血管并发症的患者TG水平明显高于无并发症的患者。TG水平与血清ALB水平、透析时体外循环血流量显著相关；HDLC与KT／V显著相关。LRP5′端四核苷酸重复序列与外显子3 RsaⅠ位点基因多态性，对血液透析患者血脂水平无显著影响。     

血液透析患者低密度脂蛋白受体相关蛋白Rsa Ⅰ位点基因多态性对血脂水平的影响

目的 探讨血液透析患者脂代谢紊乱的临床特征及低密度脂蛋白受体相关蛋白(LRP)外显子3RsaⅠ位点基因多态性对脂代谢的影响.方法 生化方法检测血液透析患者血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDLC)、低密度脂蛋白胆固醇(LDLC)、载脂蛋白(Apo)A1、ApoB、ApoE及脂蛋白(Lp)(a)水平,多聚合酶链反应-限制性片断长度多态性方法( PCR - RFLP)检测LRP外显子3Rsa Ⅰ位点基因多态性.健康体检者372例作为对照组.结果 血液透析患者脂代谢紊乱主要表现为血清TG水平显著增高,HDLC水平显著降低.血清TG水平高于正常者为33％,HDLC低于正常者为10.4％.偏相关回归分析显示,TG水平与血清ALB水平、透析时体外循环血流量显著相关;HDLC与KT/V显著相关.血液透析患者高血压的发生率为73.6％,心血管疾病为25％.伴心血管疾病组TG水平显著高于无心血管疾病组,伴高血压组与无高血压组血脂水平无显著差异.LRP基因多态性分析显示,LRP外显子3基因型C/C与等位基因C发生频率较高,病例组与对照组间无显著差异.对照组基因型C/T者血清TC、TG、LDLC水平高于基因型为C/C者,后者具有显著性差异;病例组无显著差异病例组外显子3 Rsa Ⅰ位点不同基因型间血脂水平无显著差异.结论 血液透析患者脂代谢紊乱主要表现为血清TG、ApoB水平显著增高,HDLC等指标显著降低.伴心血管并发症的患者TG水平显著高于无并发症的患者.TG水平与血清ALB水平、透析时体外循环血流量显著相关;HDLC与KT/V显著相关.LRP外显子3 Rsa Ⅰ位点基因多态性对正常人群与血液透析患者血脂水平有不同的影响.     

胆囊结石病家系的基因多态性研究

目的 从胆囊结石病多发家系角度来探讨胆石症发病的分子基础并研究部分胆石病易感基因在胆石病家系成员中的分布及与胆石病的关系。方法 收集调查上海地区93个胆石病家系，通过胆囊B超检查证实每个家系至少有2名胆石病患，对333名家系成员（其中患239人）进行临床调查并检测血脂水平，应用PCR－RFLP（PCR－限制性多形性碎片长度）法来检测胆石病易感基因载脂蛋白B（Apo B)基因Xbal和载脂蛋白E（Apo E)基因Hha I的多态性位点基因型，分析各基因型和等位基因在家系成员中的分布情况。结果 （1）Apo B基因Xba I多态性X^ /-基因型频率在胆石组为5．9％，非胆石组为10．6％，分布无显性差异。不同的Apo B基因型，其血液生化指标无显性差异。（2）Apo E基因多态性各等位基因ε2、ε3和ε4的分布频率在胆石组分别为：6．9％、81．4％和11．7％，在非胆石组分别为：9．0％、81．4％和9．6％，分布无显性差异。年龄段为≤40岁的家系成员中，Apo E4/x(Apo E3/4,Apo E4/4)基因型在胆石组的分布频率（20．6％）显高于非胆石组（0％）（P＝0．04）。不同的Apo E基因型对血脂水平有着不同的影响，总体上看，E2／x(Apo E2/2,Apo E2/3)基因型的血清TG和HDLC显升高，LDLC显降低（P＜0．05）；而E4／x基因型的TC、LDLC、Apo B以及Apo E均显升高，HDLC、Apo A1显降低（P＜0．05）。结论 ε4等位基因可能是胆石病的易感基因，Apo B基因X^ 等位基因和胆石病的关系有待进一步确定。     

血管紧张素转换酶2和血管紧张素转换酶基因多态性与妊娠糖尿病孕妇及正常孕妇血脂水平的相关性研究

目的探讨血管紧张素转换酶2（ACE2）单核苷酸多态性位点rs2285666和rs2106809及血管紧张素转换酶（ACE）插入／缺失（I／D）多态性与妊娠糖尿病（GDM）孕妇及正常孕妇妊娠中晚期血脂水平的相关性。方法选取GDM孕妇344例,糖耐量正常（NOT）孕妇417例。采用聚合酶链反应（PCR）及聚合酶链反应-限制性片断长度多态性（PCR—RFLP）方法检测ACE2及ACE基因多态性,并于孕24～28周留取受试者空腹静脉血检测总胆固醇（TC）、甘油三酯（TG）、高密度脂蛋白胆固醇（HDLC）、低密度脂蛋白胆固醇（LDLC）、载脂蛋白A1（ApoA1）、载脂蛋白B（ApoB）和脂蛋白a[Lp（a）]水平。结果GDM和NGT两组间ACE2 rs2285666、rs2106809和ACE I／D基因型及等位基因分布频率均无统计学差异（P〉0．05）。GDM患者的TG水平显著高于NGT孕妇[（2．69±0．95）mmol／L vs（2．38±0．81）mmol／L]（P〈0．05）,HDLC水平显著低于NGT孕妇[（2．11±0．46）mmol／L vs（2．20±0．43）mmol／L]（P〈0．05）。将受试者按ACE2 rs2285666、rs2106809ACE和ACE I／D基因型分组,ACE DD基因型组TC、LDLC水平高于ACEⅡ组,分别为（6．33±1．09）mmol／L vs（6．05＋0．96）mmol／L、（3．62±0．89）mmol／L vs（3．39±0．79）mmol／L（P〈0．05）,进一步将受试者分别按ACE I／D基因型分组,NGT组DD基因型受试者TC和LDLC水平明显高于Ⅱ基因型组,分别为（6．46±1．20）mmol／L vs（6．06±0．95）mmol／L和（3．73±1．03）mmol／L vs（3．43±0．77）mmol／L（P〈0．05）,而GDM组各基因型组之间各血脂水平无显著差异。结论ACE I／D多态性与孕妇孕中晚期血脂水平有关,NGT组DD基因型孕妇比Ⅱ基因型孕妇的TC、LDL水平高,GDM可能也存在ACE I／D多态性对孕妇妊娠中晚期血脂水平的影响。     

胆固醇水平高者结肠腺瘤发生危险增加

流行病学资料表明，高脂饮食和肥胖与结肠癌的发病率上升密切相关，血脂水平与结肠腺瘤之间亦存在一定关系。武汉大学人民医院周中银等发现，血浆总胆固醇水平增高者，结肠腺瘤发生的危险性增加，而ApoEε3／ε4基因型携带者结肠腺瘤发生的危险减少。     

胆囊结石病家系的基因多态性研究

目的 从胆囊结石病多发家系角度来探讨胆石症发病的分子基础并研究部分胆石病易感基因在胆石病家系成员中的分布及与胆石病的关系。方法 收集调查上海地区93个胆石病家系,通过胆囊B超检查证实每个家系至少有2名胆石病患者,对333名家系成员（其中患者239人）进行临床调查并检测血脂水平,应用 PCR-RFLP（PCR-限制性多形性碎片长度）法来检测胆石病易感基因载脂蛋白 B（Apo B）基因Xbal和载脂蛋白E（Apo E）基因Hha I的多态性位点基因型,分析各基因型和等位基因在家系成员中的分布情况。结果 （1）Apo B基因 Xba　I多态性 X+/-基因型频率在胆石组为5.9％,非胆石组为10.6％,分布无显著性差异。不同的Apo　B基因型,其血液生化指标无显著性差异。（2）Apo E基因多态性各等位基因ε2、ε3和ε4的分布频率在胆石组分别为:6.9％、81.4％和11.7％,在非胆石组分别为:9.0％、81.4％和9.6％,分布无显著性差异。年龄段为≤40岁的家系成员中,Apo E4/x（Apo E3/4,Apo E4/4）基因型在胆石组的分布频率（20.6％）显著高于非胆石组（0％）（P=0.04）。不同的Apo E基因型对血脂水平有着不同的影响,总体上看,E2/x（Apo E2/2,Apo E2/3）基因型者的血清TG和HDLC显著升高,LDLC显著降低（P<0.05）;而E4/x基因型者的TC、LDLC、Apo     

载脂蛋白E与胆囊胆固醇结石关系的研究

目的 探讨载脂蛋白Ｅ（ａｐｏｌｉｐｏｐｒｏｔｅｉｎ Ｅ）基因多态性与胆囊胆固醇结石形成的关系。方法 应用聚合酶链反应（ＰＣＲ）技术检测６０例健康人和４０例胆囊胆固醇结石患者的Ａｐｏ Ｅ基因多态性及等位基因频率。结果 胆囊胆固醇结石患者Ａｐｏ Ｅ基因型Ｅ３／４的频率２３％（９／４０）明显高于健康对照组７％（４／６０）（Ｐ〈０．０５）,胆囊胆固醇结石患者组ε４等位基因频率为１５％（１２／８０）,明显高     

血液透析患者脂代谢紊乱的临床研究

目的探讨血液透析患者脂代谢紊乱的临床特征及原因。方法检测106例维持性血液透析患者空腹血脂，并对影响血脂水平及有关因素进行分析。结果血液透析患者脂代谢紊乱主要表现为血清甘油三脂（TG）、载脂蛋白B（Apo-LB）水平显著增高，高密度脂蛋白胆固醇（HDLC）显著降低。TG与血清白蛋白（Alb）、透析时体外循环血流量显著负相关（r=-0．398，r=-0．219）；HDLC水平与Kt／V显著相关（r=-0．305）。血液透析患者高血压的发生率为73．6％，心血管病变为25％。伴心血管疾病的血液透析患者TG水平显著高于无心血管疾病者。结论血液透析患者脂代谢紊乱主要表现为TG、Apo-LB水平增高，HDLC水平降低。透析充分及透析时体外循环血流量及血清白蛋白水平影响血脂水平。     

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.     

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.     

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.