GPC-Ⅱ-3液间歇低温灌流对兔肾的保护作用

目的：探讨供肾保存新技术。方法：用自制的器官保存液（GPC-II-3）以间歇低温灌流保存的方法，对兔肾进行0-192h的连续保存，观察其形态结构的变化。结果：肾脏在保存0-120h期间的组织结构正常，保存到144h时，肾脏的光镜下结构也基本正常，但电镜下见肾小管上皮线粒体嵴明显减少等改变。结论：用GPC-II-3保存液以间歇低温灌流法，能在形态结构上保存兔肾120h，是有效的器官保存方法。     

川芎嗪改善高渗枸橼酸盐嘌呤溶液保存犬肾的效果

目的探讨一定浓度的川芎嗪对低温保存的犬肾的影响。方法分别以2～4℃加入川芎嗪（终浓度为4mg／L）的新型高渗枸橼酸盐嘌呤溶液（HC-A Ⅱ液，实验组）、HC-A Ⅱ液（HC-AⅡ液组）及UW液（UW液组）灌注肾脏，然后进行组织病理学观察及细胞凋亡测定。将按上述方法保存48、72h的肾脏进行自体移植，术后观察血肌酐浓度、恢复正常的时间以及受者的存活情况。结果体外保存实验中，在保存时间不超过48h时，三个组的组织形态基本相似，但保存72h后，实验组和UW液组肾组织的病理改变明显轻于HC-A Ⅱ液组，细胞凋亡指数也明显低于HC-A Ⅱ液组（P〈0．05），实验组和UW液组的上述指标相比较，差异无统计学意义（P〉0．05）。经保存的肾脏自体移植后，单纯HC-A Ⅱ液保存72h者有2只犬（2／5）因肾功能衰竭死亡；不论是保存48h还是72h，采用含川芎嗪的HC-AⅡ 液和UW液保存者移植后血肌酐水平明显低于单纯HC-A Ⅱ液保存者（P〈0．05），其肾功能恢复正常的时间也较单纯HC-AⅡ液保存者缩短（P〈0．05）。结论HCA-Ⅱ液中加入一定浓度的川芎嗪能改善肾脏低温灌注保存的效果。     

不同灌注液对常温体外灌流兔肾的影响

目前,肾脏体外保存主要是浅低温保存[1],低温保存有诸多局限性。我们不是按传统的思路降低保存肾脏的代谢,而是从尽量满足保存肾脏的代谢需求的角度研究肾脏的体外保存。我们在以往研究不同灌注压、不同解痉剂对体外灌流兔肾灌流量影响的基础上,进一步探讨不同灌流液对常温体外灌流兔肾功能及其灌流保存时间的影响,为建立体外灌流保存肾脏的模型,最终建立肾库作技术准备。     

应用钙离子拮抗剂保护离体肾的实验研究

目的 探讨钙离子拮抗剂对离体肾的保护作用。方法 以3月龄的日本纯种大耳兔为实验对象,分为正常组、实验对照组和实验组,实验对照组将肾脏置于4℃高渗枸橼酸盐腺嘌呤器官保存液（HC－A）中保存24h,实验组将肾脏置于4℃含维拉帕米的HC－A液中保存24h。正常组肾切取即刻测定肾细胞线粒体内钙离子及肾组织中三磷酸腺苷（ATP）的含量;实验对照组和实验组保存24h后测定肾细胞线粒体内钙离子及肾组织中ATP的含量。结果 与肾脏切除后立即检测组相比,实验对照组肾细胞线粒体内Ca∧2＋含量明显上升（P＜0．01）,ATP明显下降（P＜0．01）;实验组上述改变可得以显著改善（P＜0．01）。结论 在离体肾保存中,应用钙离子拮抗剂维拉帕米可阻止Ca∧2＋进入细胞线粒体内,防止能量消耗,从而保护离体肾。     

长征-1号多器官保存液效果的动物实验研究

目的　研究长征１ 号（ＣＺ１） 多器官保存液对肾脏低温保存的有效性及移植存活率的影响。　方法　（１） 采用离体肾脏灌注模型,分别检测了低温延时保存后兔肾线粒体呼吸控制率（ＲＣＲ）、Ｎａ＋Ｋ＋ＡＴＰａｓｅ 活性、皮质线粒体Ｃａ２ ＋ 、皮质ＡＴＰ等含量的变化。（２） 采用ＳＤ 大鼠肾脏移植模型,分别观察了低温延时保存４８ 、７２ 小时后再移植,大鼠存活以及移植肾功能恢复情况。　结果　（１）ＣＺ１ 液组保存７２ 小时,其生化指标肾脏线粒体呼吸控制率、皮质线粒体Ｃａ２＋ 、皮质ＡＴＰ含量的变化均优于ＵＷ 液组;（２）经ＵＷ 液和ＣＺ１ 液低温保存供肾４８ 小时,７ 天之内肾功能恢复正常。保存供肾７２ 小时,１４ 天之内肾功能基本接近正常。　结论　长征１ 号多器官保存液对肾脏低温保存效果基本类同于ＵＷ 液,且部分生化学结果优于ＵＷ 液。     

亚低温下肾保存的实验研究

为了进一步提高肾移植的水平，了解肾脏在低温保存下的病理改变及生化指标的变化，利用低温可控冰箱，以ＨＣＡ液作为灌洗及保存液，对兔肾进行不同温度（４℃、０℃，－２℃、－４℃）及不同时间（７２、９６、１２０小时）的保存，经对保存肾脏进行形态及功能方面观察，认为灌洗后静脉流出液ＬＤＨ浓度及光、电镜观察是肾保存质量观察的可靠指标。同时，在－２℃以下温度保存的肾皮质细胞在镜下可见有冰晶形成引起的空泡，它对肾脏细胞及结构产生严重的损害。     

含饱和氢气肾保存液对大鼠肾脏冷缺血再灌注损伤的影响

目的 评价含饱和氢气肾保存液对大鼠肾脏冷缺血再灌注损伤的影响.方法 健康雄性Wistar大鼠24只,周龄8～10周,体重200～ 250 g,采用随机数字表法,将其随机分为3组(n=8):对照组(H1组)大鼠仅切除右肾;普通肾保存液组(H2组)大鼠采用冷缺血再灌注模型,用4℃普通HC-A肾保存液对左肾行冷灌注和冷保存;含饱和氢气肾保存液组(H3组)大鼠操作同H2组,灌注液及保存液换用自制的4℃含饱和氢气HC-A肾保存液.于再灌注24 h时抽取下腔静脉血样,测定血清BUN、Cr、TNF-α和IL-6浓度;切取左肾,测定肾组织MDA和8-羟基脱氧鸟苷(8-OHdG)含量,光镜下观察肾组织病理学结果.结果 与H1组相比,H2组和H3组大鼠血清BUN、Cr、TNF-α和IL-6浓度及肾组织MDA和8-OHdG含量均升高(P＜ 0.05);与H2组相比,H3组血清BUN、Cr、TNF-α和IL-6浓度及肾组织MDA和8-OHdG的含量均降低(P＜0.05).H1组肾组织形态结构未见明显异常,H2组肾小管损伤明显,H3组肾小管损伤较H2组减轻.结论 含饱和氢气肾保存液可明显减轻大鼠肾脏冷缺血再灌注损伤.     

新型器官保存液低温保存猪肾效果的研究

目的研究新型器官保存液Lifor液对猪肾脏的低温保存效果。方法 24只白色杂种猪,随机均分为Lifor液保存组和威斯康星大学保存液（UW液）组各12只,建立离体肾脏非循环灌注模型,供肾取出后分别以0~4℃的Lifor液和UW液灌注并低温保存,再根据保存时间随机分成2个亚组,分别为保存24h、48h组,然后行猪自体肾移植。比较两组肾脏低温保存结束后其病理学及肾皮质三磷腺苷（ATP）含量的改变,并观察自体肾移植后肾功能恢复情况。结果供肾离体保存24h、48h后,Lifor液组与UW液组的肾组织病理学改变基本一致,肾皮质ATP含量比较差异无统计学意义（P〉0.05）。移植后两组血清肌酐水平比较差异亦无统计学意义（P〉0.05）。结论 Lifor液低温保存肾脏的效果与UW液相当,且成本低廉,因此更具有临床应用前景。     

长征－1号多器官保存液对兔肾脏冷冻保存的连续形态学观察

自１９９２年始研制成功长征－１号多器官保存液（简称ＣＺ－１液）。在完成对兔心脏及肝脏的冷冻保存后的形态学变化观察后，又做了对兔肾脏冷冻保存的形态学改变观察，并与ＵＷ液和ＨＣ－Ａ液作了比较。结果表明：冷冻保存７２小时以内ＣＺ－１液组肾脏组织光镜和电镜下形态学改变与ＵＷ组相比无明显区别，而且ＣＺ－１液组冷冻保存肾脏组织的变化以及细胞和细胞器的变性均缓于ＨＣ－Ａ组。由于ＨＣ－Ａ液已被证实能有效地保存犬肾在７２小时内，临床保存供肾在５７小时以内，ＵＷ液已经被证实能有效地保存供肾在７２小时以内，因此认为：从光镜和电镜下肾脏组织观察来看，ＣＺ－１液能保存兔肾脏在７２小时之内。     

胰、十二指肠及肾联合获取、修整和保存的实验研究

目的：对供者胰、十二指肠及肾等器官的联合获取、修整和保存方法进行研究。方法：采用原位腹主动脉插管、低温灌注、快速整块切取及体外修整获得可供移植的胰、十二指肠及肾移植物。2例用UW液保存的供胰用于实验研究。结果：获取8例供者的移植物,平均热缺血时间为4min50s,获取时间为18min20s。7例修整成适用于临床作胰、十二指肠及肾的移植物,平均时间为2h。后4次采用UW液灌注和保存的供者器官中,对其中2例供胰进行了保存研究,UW液保存18h的供胰超微结构正常。结论：此方法适合于供者胰、十二指肠及肾的联合获取、修整和保存。     

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.     

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.     

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.