微囊化人胎胰岛功能的体外观察

目的 :观察微囊的通透性及对微囊化胰岛分泌功能的影响。方法 :将用胶原酶消化获得的胰岛细胞分为 2份 ,1份微囊包膜 ,1份未予包膜作为对照 ,培养 7天 ,比较两组培养液中胰岛素含量并分别用2 .7mmol·L-1、16 .6mmol·L-1浓度的葡萄糖及 16 .6mmol·L-1的葡萄糖加 10mmol·L-1茶碱刺激胰岛B细胞 ,观察其胰岛素分泌功能。结果 :两组在培养液中胰岛素含量及葡萄糖、茶碱刺激的胰岛B细胞胰岛素分泌方面无显著性差异 (P >0 .0 5 )。结论 :该微囊具有良好的通透性 ,微囊化胰岛的活性和分泌功能未受成囊过程的影响     

海藻酸-壳聚糖-聚乙烯乙二醇微囊化异种胰岛移植治疗小鼠糖尿病

目的比较海藻酸-聚赖氨酸-海藻酸微囊化(APA)大鼠胰岛和海藻酸-壳聚糖-聚乙烯乙二醇微囊化(ACP)大鼠胰岛移植对小鼠糖尿病的治疗作用.方法链脲霉素220 mg/kg体重腹腔内注射制作小鼠糖尿病动物模型.成模后分成APA微囊组、ACP微囊组和未微囊化胰岛组,每只小鼠腹腔内分别植入200个相应胰岛,检测监测移植前后小鼠的血糖.结果移植后第1天,3组小鼠血糖均较移植前明显降低.未微囊化胰岛移植组小鼠术后第2天血糖均恢复到术前水平;APA微囊组和ACP微囊组小鼠血糖分别维持正常(57.00±14.61)d和(41.67±16.73)d,此两组间差异无显著性(P＞0.05),但均较未微囊化胰岛移植组明显延长(P＜0.05).结论 ACP微囊与APA微囊一样具有免疫隔离作用;ACP微囊化异种胰岛移植可纠正小鼠糖尿病.     

微囊化异种甲状旁腺组织移植的研究

目的探讨微囊化异种甲状旁腺(PTG)组织移植对Wistar大鼠甲状旁腺功能低下的治疗作用及微囊的通透性。方法 40只去甲状旁腺Wistar大鼠随机分为微囊组、非微囊组、空囊组、空白对照组。用海藻酸-钡交联微囊包裹兔甲状旁腺组织,移植至Wistar大鼠肾包囊。移植后每隔2周取血测血钙,移植后第16周取移植物进行透射电镜检查及T淋巴细胞、大鼠IgG抗体的免疫组织化学染色。结果微囊组移植后第4周血清钙由(1．62±0．04)mmol／L恢复至正常水平 (2．2～2．6)mmol／L,9例维持至观察期结束(P<0．01),非微囊组、空囊组及空白对照组血清钙差异无统计学意义(P>0．05)。第16周取出移植物检测显示移植物活性良好,微囊周围可见较多T 淋巴细胞浸润,囊壁及囊内IgG抗体染色阳性。结论海藻酸-钡交联微囊可对甲状旁腺组织起到有效的保护作用,使甲状旁腺组织较长时间存活并发挥正常功能。但海藻酸-钡交联微囊并未减轻受体免疫排斥反应的激活且未有效的免疫隔离IgG抗体。     

供者肝脾细胞输注与改良的微囊法联合应用延长异种胰岛移植的存活

目的探讨改良的微囊胰岛和肝脾细胞输注联合应用,对异种胰岛细胞移植的影响。方法以新生杜洛克小猪为供者,糖尿病SD大鼠为受者。将受者随机分为6组:第1组为肝脾细胞输注移植组;第2组为微囊胰岛细胞移植组;第3组为联合应用移植组;第4组为裸胰岛细胞移植组;第5组为空囊移植对照组;第6组为生理盐水对照组。各组经尾静脉输注肝脾细胞或生理盐水,再将相应的移植物植入大鼠腹腔。术后观测血糖、血清C肽变化、移植胰岛的功能存活期及糖尿病大鼠的生存期。结果第3组控制血糖水平和血清C肽释放量比第1、2组更为平稳而持久,并明显延长移植胰岛的功能存活期和糖尿病大鼠的生存期(P<0.01)。结论异种胰岛细胞移植中,肝脾细胞输注与静电改良微囊法联合应用可诱导免疫耐受,能有效地延长移植胰岛的功能存活期。     

海藻酸钠-氯化钡微囊对大鼠胰岛体外胰岛素分泌功能的影响

目的　观察海藻酸钠 -氯化钡微囊对大鼠胰岛体外胰岛素分泌功能有无影响。方法　以海藻酸钠和氯化钡为材料 ,采用气体吹喷制囊法将新鲜分离纯化的大鼠胰岛制成微囊化胰岛 ,取空微囊、微囊化大鼠胰岛与未微囊化大鼠胰岛各 5 0 0只 ,分为 10份 ,置于培养板中培养 ,用放免法测定并比较第 2、4、6 d培养液中基础胰岛素浓度。结果　空微囊组第 2、4、6 d的基础胰岛素平均浓度均为 0 nm ol/ 1/ 5 0 ,微囊化大鼠胰岛组第 2、4、6 d的基础胰岛素平均浓度为 5 .179、5 .80 6、5 .5 5 8nm ol/ 1/5 0只 ,未微囊化大鼠胰岛组第 2、4、6 d的基础胰岛素平均浓度为 5 .4 4 1、6 .0 80、5 .4 6 8nmol/ 1/ 5 0只 ,后两者差异无显著性意义 (P>0 .0 5 )。结论　海藻酸钠 -氯化钡微囊对大鼠胰岛体外胰岛素分泌功能无影响     

共微囊化异种肝细胞胰岛联合移植治疗急性肝衰

目的　探讨共微囊化异种肝细胞胰岛联合移植对急性肝衰的治疗作用。方法　D 氨基半乳糖诱导小鼠急性肝衰 ;Seglen法分离大鼠肝细胞 ;Sutton法分离胰岛 ;自制双喷头成囊器制备微囊。比较生理盐水、自由肝细胞移植、微囊化肝细胞移植、共微囊化肝细胞胰岛联合移植 4组间存活率、体重、谷丙转氨酶、血清白蛋白、总胆红素、血糖等指标的变化情况。结果　共微囊化肝细胞胰岛联合移植组存活率达 10 0 % ,组间差异有显著性 (P <0 .0 5 ) ,各项生化指标也明显占优。肝细胞与胰岛 β细胞可在微囊内融合。 结论　共微囊化肝细胞胰岛联合移植对氨基半乳糖诱导的急性肝衰有最佳的治疗作用     

骨髓间充质细胞和单个核细胞移植对糖尿病小鼠胰岛功能的影响

目的 比较骨髓间充质细胞移植和单个核细胞移植对糖尿病小鼠胰岛功能影响的差异.方法 建立糖尿病小鼠模型并分成3组:对照组(n=14)通过尾静脉注射磷酸盐缓冲液(PBS);单个核细胞组(n=14)通过尾静脉移植骨髓单个核细胞;间充质细胞组(n=14)通过尾静脉移植骨髓间充质细胞.观察移植后1周(n=6)和移植后6周(n=8),各组小鼠血糖的变化、胰岛数量、胰腺组织形态学特征及相关标记物的表达.结果 移植后1周,间充质细胞组小鼠血糖出现显著下降(16.6±1.6)mmol/L,与对照组(26.3±0.5)mmol/L和单个核细胞移植组(24.4±1.3)mmol/L比较差异有统计学意义(P＜0.05),并一直维持到移植后第6周,血糖下降到(16.5±1.5)mmol/L,与对照组(27.7±0.1)mmol/L比较差异有统计学意义(P＜0.05);移植后1周,间充质细胞组小鼠胰岛数目(21.2±1. 1)和胰岛β细胞数目(415.9±25.4)显著增加,与对照组(11.2±1.3)/(65.9±7.1)和单个核细胞组(12.2±1.3)/(64.1±6.5)比较差异均有统计学意义(P均＜0.05).单个核细胞组和间充质细胞组小鼠胰岛中均发现BrdU(+)Insulin(+)细胞和BrdU(+)Insulin(-)细胞.结论 骨髓间充质细胞移植改善糖尿病小鼠胰岛功能的效果优于骨髓单个核细胞移植.移植后胰岛的再生既来源于胰岛β细胞的增殖,也可能来源于胰岛干细胞的分化.

Abstract：

Objective To compare the different effects of bone marrow mononuclear cells vs mesenchymal cells transplantation on islets function of diabetic mice. Methods Mouse diabetic models were created by multiply peritoneal injection of low-dose streptozotocin (STZ) and divided into three groups:control group ( n = 14) , bone marrow mononuclear cells group ( n = 14) , and bone marrow mesenchymal cells group (n = 14). Blood glucose was measured weekly after transplantation by glucometer. Histochem istry and immunofluorescence were performed to characterize pancreatic histology, morphology and markers expressed in receipt pancreas. Results Compared with control group and bone marrow mesenchymal cells group, blood glucose levels in bone marrow mesenchymal cells group were significantly reduced at first week after transplantation[( 16. 6 ± 1.6 ) vs ( 26. 3 ± 0. 5 ) / ( 24. 4 ± 1.3 ) mmol/L, P ＜ 0. 05]and sustained to reduce at 6th week after transplantation[( 16. 5 ± 1.5 ) vs ( 27.7 ± 0. 1 ) mmol/L in control group,P＜0. 05]. One week after transplantation, the islets number in bone marrow mesenchymal cells group was larger than in control group ( 21.2 ± 1. 1vs 11.2 ± 1.3, P ＜ 0. 05 ) and bone marrow mononuclear cells group ( 21.2 ± 1. 1vs 12. 2 ± 1.3 ,P ＜0. 05 ). One weeks after transplantation, the beta cell number in bone marrow mesenchymal cells group was larger than in control group (415.9 ± 25.4 vs 65.9 ±7. 1,P＜0.05) and bone marrow mononuclear cells group (415.9 ±25.4 vs 64. 1 ±6.5,P＜0.05). In bone marrow mononuclear cells and bone marrow mesenchymal cells groups, there were several BrdU ( + )Insulin( - ) cells and BrdU( + )Insulin( - ) cells in the islets. Conclusion The effect of bone marrow mesenchymal cells transplantation to improve diabetic islet function is more satisfactory than bone marrow mononuclear cells transplantation. Bone marrow mesenchymal cells transplantation can initiate pancreatic islets β cells regeneration by both proliferation of β cells and differentiation of pancreatic stem cells.     

微囊化大鼠胰岛异种移植的实验研究

目的　通过动物实验明确微囊化胰岛是否具有免疫隔离作用。方法　SD大鼠胰腺原位消化 ,Ficoll间断密度梯度离心法纯化、分离胰岛 ,气流吹喷制作海藻酸钠 /聚赖氨酸 /海藻酸钠(APA)微囊化大鼠胰岛 ,比较微囊化与未微囊化胰岛的胰岛素释放试验 ;将微囊化 (实验组 )与未微囊化 (对照组 )大鼠胰岛植入链脲佐菌素 (STZ)诱导的I型糖尿病小鼠中 ,作两组间血糖正常持续时间比较。结果　实验组与对照组的胰岛素释放试验差异无显著性 (P >0 .0 5 ) ;实验组血糖正常持续时间为 2 3～ 6 5d(平均 48d) ,对照组为 3～ 6d(平均 5d) ,两组差异有极显著性 (P <0 .0 1)。已排斥的实验组小鼠腹腔灌洗发现部分微囊化胰岛存活 ,部分已坏死 ,但微囊膜皆完整 ,囊壁无纤维化。结论　微囊具有良好的免疫隔离作用 ,可使胰岛移植物存活时间明显延长。同时推测微囊内移植物死亡与细胞因子、自由基作用或营养不足等有关。     

盆神经节海绵体内移植对双侧海绵体神经损伤后大鼠阴茎勃起功能的影响

目的　研究双侧海绵体神经离断后 ,自体盆神经节海绵体内移植对大鼠阴茎勃起功能的影响。方法　将 2 6只雄性SD大鼠 (3～ 6个月 ,30 0～ 4 0 0g 只 )随机分为 2组 :(1)实验组 (n =16 )行双侧海绵体神经离断及左盆神经节移植入左侧阴茎脚内 ;(2 )对照组 (n =10 )仅离断双侧海绵体神经。1个月及 3个月后阿朴吗啡皮下注射检测勃起功能 ,电刺激左阴茎脚移植区域或右侧盆神经节比较海绵体内压的变化 ,NADPH染色检测海绵体内一氧化氮合酶 (NOS)阳性神经纤维 ,透射电镜观察盆神经节移植后的存活情况。结果　两组大鼠 1个月及 3个月后注射阿朴吗啡后均无勃起反应 ;电刺激左阴茎脚盆神经节移植区域后亦不能导致勃起。 1个月后电刺激两组左阴茎脚后的海绵体内压变化分别为 (9 4 1± 3 2 0 )、(4 16± 2 5 8)cmH2 O(t=4 76 9,P <0 0 5 ) ,3个月后分别为 (13 6 7± 4 18)、(5 0 9± 2 74 )cmH2 O(t=9 18,P <0 0 5 )。两组大鼠左阴茎脚区域的NOS阳性神经纤维数目 1个月后分别为 (2 18 7± 2 4 5 )、(18 0± 3 7) (t=14 77,P <0 0 5 ) ,3个月后分别为 (183 2± 19 7)、(19 0± 3 8) (t =12 18,P <0 0 5 ) ;透射电镜证实了神经节移植后的存活。结论　盆神经节海绵体内移植后可以存     

微囊化罗非鱼肝细胞移植治疗大鼠急性肝功能衰竭

目的 观察微囊化罗非鱼肝细胞移植对急性肝衰大鼠的治疗作用.方法 D-氨基半乳糖制备的肝衰大鼠随机分为4组:微囊化组,裸肝细胞组、空微囊组及生理盐水组,腹腔内分别植入微囊化罗非鱼肝细胞、裸肝细胞、空微囊及生理盐水.比较各组间1周死亡率.移植后动态检测各组大鼠总胆红素,比较其差异,动态观察移植物的病理变化.结果 移植后1周内微囊化组的存活率较高(57.9%),与其他各组比较差异有统计学意义(P＜0.05).移植后48 h,微囊化组总胆红素(6.21±0.86)μmol/L明显较低,与其他各组差异有统计学意义(P＜0.01).移植后1周,微囊化组可以收集到形态完整,没有粘连的微囊,其内的肝细胞尚部分保持存活.结论 微囊化罗非鱼肝细胞移植能改善肝衰大鼠的肝功能、提高存活率.     

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.     

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.     

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.