冷保存对大鼠部分移植肝再生的影响

目的探讨冷保存对大鼠部分肝移植术后肝再生的影响。方法健康SD大鼠分为Ⅰ组（肝切除组）、Ⅱ组（冷保存1h部分肝移植组）和Ⅲ组（冷保存8h部分肝移植组）。观察各实验组生存率，比较各组术后1、6、12、24、48、72、168h肝质量／体质量比率、肝再生率、有丝分裂指数及增殖细胞核抗原表达。结果Ⅰ、Ⅱ、Ⅲ组7d存活率分别为100％、90％、40％；Ⅲ组术后2～3d大鼠肝质量／体质量比率、肝再生率、有丝分裂指数较Ⅰ、Ⅱ组明显偏低（P〈0．05）；Ⅲ组术后12h内增殖细胞核抗原表达较其余两组明显偏低（P〈0．05），48h才达高峰，至第7天阳性表达仍处高水平。结论长时间冷保存降低了部分肝移植术后的肝再生能力和大鼠术后生存率。     

肝再生增强因子促进肝再生的细胞信号途径研究

目的探讨肝再生增强因子（ALR）促进肝部分切除（PH）后再生的机制。方法采用肝再生率评价ALR对PH后肝再生的作用；MTT检测ALR协同肝再生大鼠血清对肝细胞增殖和ALR对TGF-β1抑制肝细胞增殖的作用；免疫组化观察再生肝中ALR的表达；免疫细胞化学和Western blot检测经ALR刺激后肝细胞中ALR表达变化。结果ALR明显促进PH后的肝再生，可协同肝再生大鼠血清促进肝细胞增殖；ALR能拮抗TGF-β1对肝细胞增殖的抑制；ALR主要表达于正常肝细胞浆内；PH后2～3d肝细胞ALR减少甚至消失，第6天随着肝再生的完成，ALR含量又恢复正常；ALR刺激后肝细胞内源性ALR表达增高。结论ALR能以自主分泌方式从肝细胞中释放，与间质细胞产生的肝再生调控因子相互作用，如抑制TGF-β1生物活性，间接促进PH后的肝再生过程。     

信号调节蛋白α1在大鼠肝再生过程中表达的实验研究

目的：观察信号调节蛋白α1（SIRPα1）在大鼠肝再生过程中的表达变化。方法：选取雄性SD大鼠120只，随机分为两组：假手术组（SO）和肝切除手术组（OP），每一组又分为10个时间点，即手术后2、6、12、24、30、48、72、120、168和240h，每一时间点6只，切除大鼠70％肝脏（肝左叶和中叶）建立肝再生模型，术后在预定时间点分别取肝组织固定石腊包埋切片，采用免疫组织化学方法测定肝组织SIRPα1表达。结果：再生肝组织12h肝实质可见局灶散在肝细胞膜棕黄色着色，24h弥漫性肝细胞膜着色，120h以后肝细胞膜着色逐渐减弱。结论：SIRPα1作为一种负向调控因子参与了肝细胞再生，可能与肝再生终止有关，但关于其详细调控机制及其与其他因子相互作用的机制有待于进一步研究。     

术后肝再生进程中肝细胞脂肪聚积相关性基因的筛查分析

目的观察肝部分切除术(PH)后肝再生过程中肝细胞一过性脂肪聚积相关性基因的表达谱。方法小鼠随机分为70%PH组(按术后时间分为0-72 h时相小组,每小组5只)和假手术组(分组同前)。不同时相点获取的肝组织分别实施油红O染色的肝细胞脂聚积分析和RNA制备。用cDNA微阵列法筛查并用实时RT-PCR确认PH组和假手术组各时相点(0～24 h)生脂基因的诱导表达情况。结果与假手术组和手术组0 h等时相点比较,PH后的12 h和24h时相点的油红O染色明显增强。经cDNA微阵列筛查并经实时RT-PCR独立确认的、仅在PH后6 h和或12 h时相点诱导表达的生脂基因有:Adipsin、AP2、S3-12和FSP27。结论术后肝再生过程中,肝细胞在聚积大量脂肪之前启动了一个与脂肪聚积相关的生脂基因表达程序。     

重组人肝再生增强因子可增强大鼠肝星状细胞间质胶原酶基因的表达

目的：了解重组人肝再生增强因子（hALR)对大鼠肝星状细胞间质胶原酶（MMP13）基因表达的影响。方法：在培养的肝星状细胞系中加入200、20、2μg/L3种浓度的hALR，于8、24、48、72h4个时间点收集细胞，提取总RNA；用逆转宝量聚合酶链反应（PCR）方法测定MMP13的基因表达水平。结果：高、中、低浓度的hALR3组肝星状细胞MMP13基因表达水平在8、24、48、72h4个时间点均明显高于对照组；最高值均出现在24－48h，低剂量组为对照组的3倍，中剂量组为对照组的4倍，高剂量组达对照组的6倍。结论：重组人肝再生增强因子对大鼠肝星状细胞间质胶原酶基因表达有明显的促进作用。     

缺血预处理对肝大部切除术中残肝缺血再灌注损伤的保护作用

目的 观察缺血预处理对大鼠肝大部切除术中残肝缺血再灌注损伤的保护作用。方法 健康的雌性SD大鼠随机分为3组：即单纯肝叶切除组（PH组）、缺血再灌注损伤状态下肝叶切除组（IR组）及缺血预处理组（IP组）。分别取术前及术后0．5、6、12、24、48h等时间点，应用全自动生化分析仪检测血清ALT、AST含量，通过免疫组织化学法检测残肝组织中Ki67和Cyclin D1表达变化，采用放免法检测血清中透明质酸（HA）含量。结果 IP组术后24h内各检测点的AST和ALT值明显高于PH组和IR组（P〈0．05）。术后早期IP组大鼠的血清HA表达量明显高于PH组和IR组（P〈0．05）。PH组大鼠肝细胞Ki67和Cyclin D1表达在术后24h达到峰值，并且明显高于IR组和IP组大鼠（P〈0．05）。其中IP组大鼠术后Ki67和Cyclin D1表达量降低地最显著。结论 在合并肝组织大部缺失时，缺血预处理对残留肝组织的缺血再灌注损伤的保护效应消失，它损害了大鼠残肝再生功能。     

大鼠肝、胰十二指肠联合切除残肝肝细胞生长因子表达的研究

目的 用实验动物模型同时切除肝脏、胰腺及十二指肠，以探讨肝细胞生长因子(HGF)对残肝再生的影响。方法 60只SD大鼠被随机分为4组：①68％肝切除组；②68％肝叶切除加50％胰腺切除组；③68％肝叶切除加十二指肠切除组；④68％肝叶切除、加50％胰腺切除加近端十二指肠切除组。每组中3只大鼠分别于术后12、24、48、72和168h处死并采集肝脏样本，计算肝再生率。切除的肝脏组织用RT-PCR技术检测HGF在术后不同时间的表达，并与免疫组化法检测的肝细胞增殖细胞核抗原(PCNA)进行对比研究。结果 68％肝切除组残肝HGF的表达逐渐增强，24h达到高峰，随后逐渐下降，168h时达最低水平。而肝、胰切除，肝十二指肠切除和肝、胰十二指肠切除可显著减少残肝细胞HGF的表达，并使HGF的表达延迟至术后48h。结论 HGF可促进肝脏切除术后残肝的再生反应，而起源于胰腺和十二指肠外分泌腺的其他因素亦对HGF的表达起显著的调节作用，从而影响肝细胞的增殖。     

微生物酵素和促肝细胞生长素对肝切除后肝功能的影响

目的观察微生物酵素对大鼠部分肝切除后肝再生过程中肝功能的影响。方法采用大鼠部分肝切除（Partial Hepatectomy,PH）模型,通过与对照组和促肝细胞生长素（Hepatocyte Growth-Promoting Factor,pHGF）组比较,在PH后12小时、24小时、48小时、72小时、120小时和168小时,留取血清,检测血清天门冬氨酸氨基转移酶（aspartate aminotransferase,AST）、血清丙氨酸氨基转移酶（alanine aminstransferase,ALT）、血清总胆红素（total bilirubin,TB）、血清白蛋白（albumin,ALB）。结果在PH12小时-120小时,促肝细胞生长素组AST低于对照组,差异有统计学意义,微生物酵素组在48小时和72小时低于对照组,差异有统计学意义;促肝细胞生长素组在12小时、24小时、72小时和120小时ALT低于对照组,差异有统计学意义,微生物酵素组在12小时、48小时和72小时ALT低于对照组,差异有统计学意义;在PH后24小时、72小时～168小时,促肝细胞生长素组TB是低于对照组,差异有统计学意义;在PH后24小时、120小时,微生物酵素组与对照组相比TB是降低的,差异有统计学意义;促肝细胞生长素在72小时和120小时ALB高于对照组,差异有统计学意义,微生物酵素组在168小时ALB高于对照组,差异有统计学意义。结论在PH后的某些时间点上,微生物酵素同促肝细胞生长素一样具有降低AST、A坍、TB和提高ALB合成,促进肝功能恢复的作用。     

硒螺旋藻对大鼠肝叶切除术后肝细胞再生和抗氧化能力的影响

目的研究硒螺旋藻（Se—SP）对大鼠肝叶切除术后肝细胞再生和抗氧化能力的影响，以印证其生物利用价值。方法用Wistar大鼠复制67％肝叶切除动物模型，设Se—SP高剂量（H）和低剂量（L）治疗组，术前以Se—SP灌胃7d；另设生理盐水（C）及假手术对照组（S）。于手术前及其后24h取鼠肝细胞，检测硒（Se）、丙二醛（MDA）含量及谷胱甘肽过氧化物酶（GPx）和超氧化物歧化酶（SOD）活性；利用免疫组化方法测定肝细胞增生核抗原（PCNA）表达指数，慧星实验检测过氧化氢诱导的肝细胞DNA损伤。结果与C，S组相比，H组、L组肝细胞中MDA水平明显降低（P〈0．05），而Se，GPx和SOD明显升高（P〈0．05）；肝细胞PCNA指数明显升高（P〈0．05），过氧化氢诱导的DNA损伤程度较轻。结论Se—SP对肝切除鼠肝细胞具有一定的抗氧化和促再生作用。     

微生物酵素对部分肝切除大鼠肝再生的作用

目的观察微生物酵素能否促进大鼠部分肝切除后肝再生。方法采用大鼠部分肝切除（Partial Hepatectomy,PH）模型,通过与对照组和促肝细胞生长素（Hepatocyte Growth-Promoting Factor,pHGF）组比较,在pH后12小时、24小时、48小时、72小时、120小时和168小时,留取相应肝组织,检测反映肝再生的指标肝再生率（Hepatic Regeneration Rate。HRR）、增殖指数（Proliferation Index,PI）和细胞增殖核抗原（Proliferating Cell Nuclear Antigen,PCNA）。结果在pH后12小时和24小时、微生物酵素组同促肝细胞生长素组一样与对照组相比,肝再生率高,差异有统计学意义（P〈0．05）;pH后12、24、72、120小时,微生物酵素组的PI高于对照组,差异有统计学意义（分别为P〈0．05、P〈0．01、P〈0．05和P〈0．05）。在pH后72小时和168小时PCNA出现高峰,微生物酵素组与对照组相比,差异有统计学意义（P〈0．05）。结论微生物酵素同促肝细胞生长素一样具有早期促进肝再生的作用。     

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.