复方中药对坐骨神经损伤大鼠神经元保护作用的实验研究

目的　神经损伤后应用复方中药 ,观察其对神经元的保护作用。方法　选用雄性 SD大鼠18只。按手术先后随机分成实验组与对照组 ,每组 9只。将大鼠左侧坐骨神经在梨状肌下缘 0 .5 mm处切断 ,近断端双重结扎。术后实验组喂复方中药 ,对照组喂生理盐水。于术后 7、14、2 8天取 L4～ 6 脊髓及L5 背根神经节作 TUNEL 标记检测 ,标记凋亡的神经元数目。切片作 HE、焦油紫染色后计算脊髓内神经元的数目。结果　术后 7天、14天 ,实验组的凋亡细胞均少于对照组 (P <0 .0 5 ) ,2 8天时两组无明显差异 (P>0 .0 5 )。各时间组的神经元数目 ,实验组明显多于对照组 (P<0 .0 1,P<0 .0 5 )。结论　复方中药对周围神经损伤后的相应神经元 ,有一定的保护作用     

血管束植入移植神经修复外周神经损伤对神经元细胞凋亡的影响

目的 应用血管束植入移植神经修复外周神经损伤，观察其对神经元的保护作用。方法 选用雄性SD大鼠27只，随机分成神经缺损组，原位移植组与血管束植入组，每组9只，并按手术先后随机分成7、14、28d三个时间组，将大鼠左侧坐骨神经在梨状肌下缘切除1.5cm，制备神经缺损动物模型，采用神经原位移植，血管束植入移植神经不同方法修复神经缺损，按术后不同时间处死动物，手术后7、14、28d取L4-6脊髓及L5背根神经节作TUNEL标记检测，标记凋亡的神经元数目，切片作HE，甲苯胺蓝染色后计算脊髓内神经元的数目。结果 在术后28d，血管植入组的凋亡细胞明显少于另两组，各时间组的神经元数目，血管束植入组明显多于另两组。结论 血管束植入移植神经对周围神经损伤后的相应神经元，有一定的保护作用。     

促红细胞生成素对大鼠坐骨神经损伤后炎性反应和细胞凋亡的影响

目的 探讨促红细胞生成素(EPO)对大鼠坐骨神经损伤后炎性反应和细胞凋亡的影响及其作用机制,为周围神经损伤的临床治疗提供实验依据.方法 雌性SD大鼠36只,制备大鼠左侧坐骨神经缺损模型,随机分为3组,即EPO组、神经生长因子(NGF)组和生理盐水(NS)组.EPO组、NGF组和NS组分别于术后立即及每日腹腔注射FPO、NGF和NS.术后7、14 d,HE染色光镜下观察L5背根神经节细胞形态变化;应用RT-PCR检测损伤近、远端坐骨神经IL-6和TNF-α mRNA的表达;以TUNEL法检测L5背根神经节细胞凋亡.结果 术后7、14 d,EPO组近、远端坐骨神经IL-6mRNA表达低于NS组,差异有统计学意义(P＜0.01);EPO组远端坐骨神经IL-6 mRNA表达低于NGF组,差异有统计学意义(P＜0.01).术后7d,EPO组近、远端坐骨神经TNF-α mRNA表达低于NS组和NGF组,差异有统计学意义(P＜0.01);术后14 d,EPO组远端坐骨神经TNF-α mRNA表达低于NS组,差异有统计学意义(P＜0.05).术后7、14 d,EPO组凋亡细胞数低于NS组,差异有统计学意义(P＜0.01);术后14 d,EPO组凋亡细胞数低于NGF组,差异有统计学意义(P＜0.05).结论 EPO可能通过减少致炎因子IL-6和TNF-α释放,减轻炎性反应,抑制细胞凋亡,对大鼠坐骨神经损伤发挥保护作用.     

局部应用FK506缓释膜片对大鼠坐骨神经缝合术后脊髓神经元的影响

目的探讨大鼠坐骨神经切断缝合术后局部应用FK506缓释膜片对脊髓神经元的保护。方法建立大鼠坐骨神经切断缝合术模型。术后分为治疗组(A组):术中神经缝合后在神经缝合口周围放置FK506缓释膜片(FK506释放率为2mg·kg·d);对照组(B组):不用药物。A、B组大鼠各为25只。于术后1、3、7、14、28d5个时相点,切取L46脊髓。标本按常规固定、脱水、冰冻切片、切片厚度为5μm,每隔20张取1张切片,每个标本取10张。采用TUNEL法行细胞凋亡检测。结果A组中仅发现少量脊髓神经元凋亡,B组的凋亡细胞明显多于A组,两组差异有统计学意义(P<0.05)。结论大鼠坐骨神经切断缝合术后局部应用FK506缓释膜片对脊髓神经元有保护作用。     

银杏叶提取物EGb24/6对受损神经神经元的保护作用及其对神经元超微结构的影响

目的 研究银杏叶提取物（EGb)对受损的大鼠坐骨神经神经元的保护作用。方法 SD雄性大鼠30只,体重180－220g。随机分成对照组和EGb24/6组,每组各15只。将对照组和EGb24/6组的鼠坐骨神经切断,近端双重结扎,远端埋入股二头肌中。术后对照组每天喂生理盐水2ml,EGb24/6组每天喂EGb24/6,2ml。术后第7、14、28d取L4－6脊髓和L5背侧神经节做如下检查：组织学检查（HE）、焦油紫染色对神经元的数目、形态进行检测;TUNEL标记凋亡的神经元;L5背侧神经节作电镜超微结构观察。结果 术后各时间点EGb24/6组神经元数目均多于对照组（P＜0．01）,细胞凋亡的数目EGb24/6组均少于对照组（P＜0．05）。L5背侧神经节超微结构观察：对照组随着时间的推移,神经元细胞核逐渐变小,核质变淡且稀疏,卫星细胞从神经元紧密相连到与之分离,线粒体肿胀、嵴消失,基质丢失。EGb24/6组神经元基本正常,细胞器丰富。结论 EGb24/6对神经损伤后相应的神经元有一定的保护作用,能减少神经元的凋亡。     

嗅鞘细胞移植对坐骨神经切断后神经元的作用

目的研究嗅鞘细胞(olfactory ensheathing cells,OECs)移植对周围神经切断后脊髓及神经节内神经元的保护作用。方法SD大鼠55只,随机分为3个组:空白组5只、实验组及对照组各25只。行右侧坐骨神经切断,近端断端行肌肉内包埋,实验组和对照组分别予OECs及细胞培养液,空白组暴露神经后不作任何处理。术后1、2、3、7和14d,分批处死,行组织学观察及TUNEL标记观察神经元的改变。结果空白组术后14d均无阳性变化。大鼠坐骨神经切断后,脊髓及神经节内均有神经元凋亡发生。术后1、2、3d实验组细胞存活率分别为98.4%±6.5%、97.6%±6.5%及95.2%±6.7%,对照组分别为97.8%±6.7%、97.4%±6.4%及94.3%±6.8%,比较差异无统计学意义(P>0.05);7、14d实验组细胞存活率分别为92.4%±8.9%、87.7%±9.4%,较对照组87.4%±8.6%、83.4%±8.5%高,差异有统计学意义(P<0.05)。术后1、2d实验组及对照组脊髓前角运动神经元无细胞凋亡;3、7、14d实验组脊髓前角运动神经元凋亡指数分别为1.2±0.8、1.4±0.6及4.1±1.3,较对照组2.1±1.1、3.1±1.1、6.1±1.8低,差异有统计学意义(P<0.05)。术后1、2、3d神经节内细胞无凋亡;7d实验组神经节内的凋亡指数2.10±0.32,较对照组4.40±0.56低,差异有统计学意义(P<0.05);14d实验组神经节内的凋亡指数4.3±1.80与对照组6.70±2.50比较,差异无统计学意义(P>0.05)。结论周围神经损伤后脊髓及神经节内神经元有神经元凋亡发生,OECs移植对神经元凋亡有保护作用。     

脑源性神经营养因子对大鼠坐骨神经损伤诱导神经元凋亡的作用

目的　观察大鼠坐骨神经损伤后脊髓运动神经元的凋亡现象及脑源性神经营养因子(BDNF)抑制凋亡的作用。方法　成年SD大鼠 2 7只 ,体重 1 80～ 2 2 0 g,随机分为对照组、BDNF组和生理盐水 (NS)组。将大鼠右侧坐骨神经于梨状肌下缘 0 .5cm处锐性切断 ,硅胶管套接神经 ,将BDNF和NS分别加入管中。于术后 3、6、1 2、2 4d取L4～ 6 脊髓作原位末端标记技术 (TUNEL)检测 ,切片作苏木素 伊红 (HE)染色计算脊髓内神经元的数目。结果　与NS组和对照组比较 ,BDNF组神经元凋亡数在伤后 6d由 (1 2 .5± 2 .2 ) %下降到 (9.3± 1 .8) % (P <0 .0 5) ;神经元存活率由(82 .6± 1 .2 ) %增加到 (88.1± 1 .4) % (P <0 .0 5)。结论　坐骨神经损伤后脊髓神经元发生凋亡 ,BDNF可显著抑制这种凋亡     

外周神经切断后诱发脊髓运动神经元细胞凋亡的形态学研究

目的 观察外周神经切断损伤后，脊髓前角运动神经元发生细胞凋亡的形态学变化。方法 采用切断成年SD大鼠左侧坐骨神经后，近端双重结扎的实验模型，分别在术后3、7、14和21d取材。应用苏木精伊红染色光镜下观察凋亡细胞的形态学变化；利用透射电镜观察不同时期凋亡细胞的超微结构变化，TUNEL染色观察脊髓前角神经元中标记阳性细胞的形态变化。结果 坐骨神经切断后3和21d，在脊髓前角可见到典型凋亡细胞，1—2周为细胞凋亡的高峰期，而且在同一时间点可以检测到处于不同阶段的凋亡细胞和典型的凋亡小体。结论 外周神经轴突损伤诱发脊髓前角运动神经元发生细胞凋亡有很重要的形态学改变。     

银杏叶提取物EGb_(24/6)对受损神经神经元的保护作用及其对神经元超微结构的影响

目的研究银杏叶提取物 (EGb)对受损的大鼠坐骨神经神经元的保护作用。方法 SD雄性大鼠 30只,体重 180～ 220 g。随机分成对照组和 EGb24/6组,每组各 15只。将对照组和 EGb24/6组的鼠坐骨神经切断,近端双重结扎,远端埋入股二头肌中。术后对照组每天喂生理盐水 2 ml, EGb24/6组每天喂 EGb24/6 2 ml。术后第 7、 14、 28 d,取 L4～ 6脊髓和 L5背侧神经节做如下检查 :组织学检查 (HE)、焦油紫染色对神经元的数目、形态进行检测; TUNEL标记凋亡的神经元; L5背侧神经节作电镜超微结构观察。结果术后各时间点 EGb24/6组神经元数目均多于对照组 (P< 0.01),细胞凋亡的数目 EGb24/6组均少于对照组 (P< 0.05)。 L5背侧神经节超微结构观察 :对照组随着时间的推移,神经元细胞核逐渐变小,核质变淡且稀疏,卫星细胞从与神经元紧密相连到与之分离,线粒体肿胀、嵴消失,基质丢失。 EGb24/6组神经元基本正常,细胞器丰富。结论 EGb24/6对神经损伤后相应的神经元有一定的保护作用,能减少神经元的凋亡。     

兔腰神经根慢性损伤后背根神经节内神经元的细胞凋亡

目的 观察兔腰神经根慢性压迫和自体髓核刺激损伤后背根神经节细胞和相应脊髓前角神经元凋亡的情况。方法 45只新西兰大白兔随机分成假手术组、神经根慢性损伤组及损伤后超短波治疗组，每组15只。每组又分为损伤后10天、30天和90天组。取兔尾部的自体髓核组织放入内径1．5mm、外径2．5mm，壁带孔的硅胶管内，压迫左侧第7腰神经根，各时间组取腰7背根神经节和相应节段的脊髓，分别用HE染色和TUNEL检测细胞凋亡数。结果 神经根慢性损伤后背根神经节感觉神经元及脊髓前角运动神经元假手术组未检测出TUNEL标记细胞，均表现为：假手术组未检测出TUNEL标记细胞，损伤组于伤后10d和30d的神经细胞凋亡指数均高于超短波组。损伤组、超短波组于损伤后10d时凋亡达高峰。而超短波治疗组各时间点的细胞凋数均低于损伤组。结论 神经根慢性损伤后DRG内感觉神经元和脊髓前角运动神经元均可发生细胞凋亡，早期超短波干预可减轻细胞凋亡的发生。     

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.     

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.     

Immunomodulation in Transplantation with Photopheresis

Abstract: Photopheresis is a technique in which peripheral blood mononuclear cells, in the presence of a photoacti-vatable compound, are exposed extracorporeally to ultraviolet A light and reinfused, inducing a host autoregula-tory immune response. Experimental work and ongoing clinical studies are helping to define the role of this novel, safe, and non-toxic immunomodulating technology in the field of transplantation.