脱细胞膀胱细胞外基质作为膀胱替代材料的实验研究

探讨异体脱细胞膀胱细胞外基质（ＥＣＭ）作为膀胱替代材料的可行性。方法将２０只兔行膀胱全切,对膀胱内细胞进行两次提取后,获得无细胞成分的膀胱ＥＣＭ,提取后的ＥＣＭ制成４ｃｍ×３ｃｍ大小备用。实验组２０只兔膀胱切除４ｃｍ×３ｃｍ大小,用异体膀胱ＥＣＭ植于缺损区。对照组１０只兔切除同样范围膀胱,用未经脱细胞处理的异体膀胱进行移植。结果实验组中膀胱移植区未见排斥反应及坏死,ＥＣＭ移植片存活良好。１个月后ＥＣＭ区已全部长入膀胱粘膜细胞和肌细胞,各项生化检查和尿动力学结果均正常。对照组移植膀胱片３～６天坏死。结论脱细胞膀胱ＥＣＭ可作为较理想的膀胱替代材料。     

异体真皮细胞外基质重建尿道的实验和临床研究

目的：寻求理想的尿道修复材料。方法: 2只犬真皮脱细胞处理后制成真皮细胞外基质框架;18只犬分为2组;异体真皮细胞外基质（ECM）移植组（实验组）15只,异体真皮移植组（对照组）3只,全麻下将尿道中段切除5cm,将同样长度真皮ECM或异体真皮缝成直径0．3cm管状替代缺损尿道,8F硅塑管留置4周,实验组分别于术后1,3,6,12,24周每次3只取材行光镜,电镜及免疫组化检查。结果：组织学显示：1周时移植物边缘腔内面有尿上皮,管壁可见少量肌束,6周时移植物区尿路上皮达4－5层,肌层分布均匀,24周后移植物已无法与宿主尿道辨别,对照组术后8－10d移植物坏死出现尿瘘,在实验基础上用于临床2例均获成功。结论ECM为理想的尿道修复材料。     

冻干无细胞膀胱黏膜下基质修复兔尿道缺损

目的　探讨冻干无细胞膀胱黏膜下基质修复尿道缺损的效果。方法　应用反复冻融-酶法及冷冻干燥技术制备冻干无细胞人体膀胱黏膜下基质。 18只新西兰白兔建立尿道中段部分缺损模型 ,尿道缺损面积约 1 0cm× 0 5cm。其中 14只兔作为实验组 ,以冻干无细胞膀胱黏膜下基质修补尿道缺损 ,术后 1、2、3、4、8、12、2 4周分别取 2只行逆行性尿道造影 ,观察尿道情况 ,并采取尿道组织进行大体、组织学及超微结构观察 ;4只兔作为对照组 ,未采用任何材料修补尿道缺损 ,直接缝合尿道海绵体包膜、皮下组织及阴茎皮肤 ,术后 2、4周分别取 2只行逆行性尿道造影 ,采取尿道组织进行大体观察。结果　实验组 14只兔均未发现明显的尿道狭窄。冻干无细胞膀胱黏膜下基质组织相容性良好 ,移植后无细胞膀胱黏膜下基质内有细胞长入 ,新生血管形成 ,术后 2周无细胞膀胱黏膜下基质移植区完全上皮化。随着移植时间的延长 ,移植区胶原纤维排列由紊乱趋于规则。结论　冻干无细胞膀胱黏膜下基质能够诱导尿道黏膜细胞迁徙、生长和上皮化 ,初步认为可以作为尿道缺损修复材料。     

犬化学去细胞神经同种异体移植的神经再生研究

目的 观察犬去细胞异体神经移植后近期神经再生的情况。谅15只家犬分成实验组（去细胞神经移植组，6只犬），对照组I（自体神经移植组，6只犬），对照组Ⅱ（新鲜异体神经移植组，3只犬），制成犬坐骨神经缺损5.0cm的模型，以上述3种神经移植物桥接修复。术后6个月行神经再生的组织学观察。结果 实验组移植段内有大量的新生神经纤维，新生血管及雪旺细胞；远端胫神经内出现大量的有髓神经纤维；靶肌肉运动终板的数量，形态及分布均良好。实验组和对照组I非常相似。结论 化学去细胞神经作为同种异体神经移植物，在修复术的粗大和长段神经缺损时不会被宿主排斥和吸收，其神经再生与自体神经移植无明显差别。     

组织工程学材料替代输尿管缺损的动物实验及临床应用

目的　寻求理想的输尿管替代材料。　方法　将２０ 只兔双侧输尿管脱细胞处理后制成输尿管细胞外基质（ＥＣＭ） ；另６０ 只兔分为３ 组：输尿管ＥＣＭ 移植组（ 实验组） ，对照组１ 及对照组２ 。　结果　实验组术后组织学检查显示１ 周时ＥＣＭ 边缘部腔内面已见移行上皮细胞，管壁有肌细胞长入。６ 周时取材ＥＣＭ 区已修复近正常输尿管组织结构。１２ 、２４ 周时ＩＶＵ 检查；输尿管显影良好，通畅。对照组１ 术后７ ～１０ 天，移植的异体输尿管均坏死。对照组２ 输尿管缺损区６ 周时均被纤维包裹而明显增粗。在实验取得满意结果的基础上成功应用于临床。　结论　异体脱细胞输尿管细胞外基质为理想的输尿管替代材料。     

膀胱无细胞基质移植物重建同种异体兔膀胱的研究

目的探讨膀胱无细胞基质移植物（BAMG）重建同种异体兔膀胱的效果。方法制备兔BAMG,用一半膀胱大小的BAMG对已行半个膀胱切除的25只同种异体兔做原位移植。8周时测定重建膀胱的容量、压力和顺应性,行膀胱造影;于术后1,2,4,8,12和16周,分别行重建膀胱的光镜和电镜观察。结果同种异体兔膀胱重建术后,肉眼可见BAMG结构上逐渐再生完全。术前与术后8周膀胱最大流出压（Pves,mas）、膀胱最大容量（VOlmax）和顺应性（VOlmax／Pves,mas）比较,差异均无统计学意义（P均〉0．05）。重建膀胱X线造影显示膀胱形态恢复正常。膀胱重建后1周时,在原膀胱和BAMG的交界处有上皮细胞、炎症细胞和毛细血管出现;2周时,BAMG有平滑肌和多层上皮细胞形成;4周后,在BAMG内可见短小的神经,各种成分以BAMG为支架继续再生;16周时,移植的无细胞基质与原膀胱在组织学上无区别。结论应用BAMG重建同种异体兔膀胱后,其结构上和功能上的再牛是以BAMG为支架逐步完成的。     

脂肪干细胞复合膀胱脱细胞基质促进膀胱再生的实验研究

目的 探讨脂肪干细胞(adipose-derived stem cell,ADSC)在兔的组织工程膀胱重建中的应用.方法 采用自体脂肪干细胞和膀胱脱细胞基质(bladder acellular matrix graft,BAMG)构建兔组织工程膀胱.应用酶消化法分离培养兔自体的ADSC,并进行流式细胞鉴定.对新鲜的兔膀胱组织进行脱细胞处理制得BAMG.将ADSC扩增后接种于BAMG表面并进行体外培养,获得组织工程膀胱.对24只雄性新西兰兔行40％ ～ 50％膀胱部分切除,分为实验组和对照组,每组12只.实验组采用自体培养的ADSC构建的组织工程膀胱对缺损膀胱进行修复,对照组采用单纯的BAMG进行修复.术后24周进行膀胱造影并取材观察组织修复再生情况. 结果 镜下观察ADSC贴壁后绝大多数为纺锤形,细胞之间以细丝拉网.流式细胞仪检测结果CD90、CD4、CD105、CD166、CD34表达均为阳性,CD106、CD45表达为阴性.ADSC种植于BAMG表面生长良好.修补24周后,对照组和实验组膀胱容量分别为术前的(69.33 ±5.05)％和(94.68±3.31)％.组织染色分析对照组显示上皮层正常,黏膜下纤维组织增生而肌层较薄;实验组则显示了与自体膀胱相似的正常的3层组织结构. 结论 采用ADSC和BAMG构建组织工程膀胱是理想的膀胱替代修补材料.     

尿道细胞外基质修复尿道缺损的研究

目的 寻求一种较理想的尿道修复材料。方法 20只家兔尿道制成尿道细胞外基质(ECM)；另40只随机分3组：尿道ECM移植组(实验组)，对照组Ⅰ及对照组Ⅱ。实验组切除尿道1．O～1．5cm后用尿道ECM修复并于术后10d、3周、6周及24周行组织再生情况观察；另于术后10周、24周各取4只行膀胱尿道造影；24周时实验组及对照组Ⅰ各取4只行尿流动力学检测；24周实验组取4只行尿道镜检查。结果 缺损修复术后10d，基质中见单层上皮细胞且有血管长入ECM；3周时尿道ECM管腔已完全被上皮细胞覆盖；6周时可见平滑肌细胞再生，炎性细胞消失；24周后其组织结构与正常组织相比差异无统计学意义。膀胱尿道造影无尿液外渗，无梗阻及结石形成。尿流动力学检测结果实验组与对照组Ⅰ差异无统计学意义；尿道镜检查证实尿道黏膜完整光滑，尿道内径及其形态正常。结论 尿道细胞外基质是一种理想的尿道修复材料。     

应用异体脱细胞尿道基质修复尿道缺损

目的探讨应用同种脱细胞尿道基质修复尿道缺损的可行性。方法将14只雄性新西兰兔分为两组，切除实验组长约1.0～1．5cm的尿道，用相应长度脱细胞尿道基质修复；对照组行假手术。术后行尿道造影并取尿道标本作病理检查。结果12只实验兔的脱细胞基质移植物没有移位。除2例狭窄、2例尿瘘外，其余满意效果。病理检测示，术后3周尿道管腔上皮化，6个月基质中平滑肌及血管再生明显。结论同种脱细胞尿道基质材料可以修复兔尿道部分缺损。     

冻干去细胞同种异体神经种植类许旺细胞修复坐骨神经缺损的实验研究

目的研究冻干去细胞异体神经修复大鼠坐骨神经缺损的效果。方法50只成年雌性DA大鼠随机分为5组，每组10只，分别用5种移植物桥接大鼠1．5cm坐骨神经缺损。A组：冻干去细胞异体神经种植类许旺细胞移植组；B组：冻干去细胞异体神经移植组；C组：去细胞异体神经移植组；D组：新鲜异体神经移植组；E组：自体神经移植组。术后4、24周通过大体观察、神经电生理、肌肉湿重及组织学指标评价各组修复神经缺损的效果。结果术后24周A、E组间差异无统计学意义（P〉0．05），A、E组的各项指标均优于B、C、D组（P〈0．05或P〈0．01）。结论冻干化学去细胞神经是良好的神经移植替代材料。     

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.