异种脱蛋白骨管移植修复大段骨缺损的力学评估

目的研究异种脱蛋白骨管移植修复大段骨缺损的生物力学变化。方法建立山羊双侧胫骨大段骨缺损模型,36只山羊(72只后肢)随机分为2组,实验组:异种脱蛋白骨管;对照组:异种脱蛋白骨粒;两组均在移植骨中添加了骨形态发生蛋白(BMP),并采用骨板、钢板双重固定修复骨缺损。术后5、10、15周对羊胫骨行影像学观察和生物力学的变化。结果影像学显示实验组在骨缺损修复及成骨方面较对照组高。生物力学测试结果表明,术后5、10、15周时实验组力学强度较对照组明显增高,差异有统计学意义(P<0.05);术后15周,实验组的生物力学强度与正常胫骨已无差异。结论应用异种脱蛋白骨管支撑复合BMP修复大段骨缺损,能够有效加强移植骨修复负重骨缺损区的力学结构。     

组织工程骨膜及脱蛋白骨修复兔桡骨大段骨缺损的早期观察

[目的]比较组织工程骨膜及脱蛋白骨对兔桡骨大段骨缺损的早期修复效果,研究组织工程骨膜移植修复大段骨缺损的可行性。[方法]分离兔骨髓间充质干细胞体外诱导增殖,制成细胞悬液接种于猪小肠黏膜下层表面,构建组织工程骨膜。3个月龄新西兰大白兔24只,随机分为3组各8只,手术制备单侧桡骨干30 mm骨膜-骨缺损模型,A组缺损区植入组织工程骨膜骨修复,B、C组则分别以猪小肠黏膜下层和脱蛋白骨作为对比。术后4周,行X线检查并杀取标本予以组织学染色及评分。[结果]经放射学和组织学观察,在A组中缺损区可见大量新骨形成并桥连两缺损端;而在B组和C组中无明显新骨产生。[结论]使用组织工程骨膜修复同种异体兔桡骨大段骨缺损是可行的,且明显优于脱蛋白骨。     

三种生物骨衍生材料修复节段性骨缺损的实验研究

目的　评价 3种生物骨衍生材料修复节段性骨缺损的成骨作用。　方法　将 6 0只健康日本大耳白兔双侧桡骨中段制成 10 mm节段性骨缺损 ,并随机分为 A、B、C、D和 E组 ,每组 12只 ,其中 A组植入复合型完全脱蛋白骨 (composite fully deproteinised bone,CFDB)、B组植入部分脱蛋白骨 (partially deproteinised bone,PDPB)、C组植入部分脱钙骨 (partially decalcified bone,PDCB)修复兔桡骨节段性缺损 ,D组自体髂骨移植 ,E组以空白缺损为对照 ,于术后4、8、12及 2 4周取材 ,通过 X线摄片和不脱钙硬组织切片检测 ,评价 3种材料的成骨作用。　结果　 X线摄片观察 :A、B与 C组 4周时材料密度较高 ;8周时材料与宿主骨交界处模糊 ;12周时材料边缘部分区域密度接近宿主骨 ;2 4周时 B组髓腔再通 ,C组缺损区域密度大部分接近宿主骨 ,有少许高密度影 ,A组缺损区域有较多高密度影。 X线片评分 4周和8周时各材料组无统计学差异 (P>0 .0 5 ) ;12周时 B组和 C组高于 A组 (P<0 .0 5 ) ;2 4周时 D组 >B组 >C组 >A组(P<0 .0 5 )。经组织学形态观察可见 4周和 8周时新骨贴附材料生长 ;以后新骨增多 ;材料随着时间的推移逐渐降解吸收 ;2 4周时成骨量 D组 >B组 >C组 >A组 (P<0 .0 5 )。　结论　 PDPB修复节段性骨缺损的效果佳 ,     

成骨细胞复合异种脱蛋白骨进行腰椎后外侧融合

目的 评价兔皮质骨来源的成骨细胞复合异种脱蛋白骨进行脊柱融合的效果.方法选取60只新西兰兔随机分4组行腰椎后外侧融合术:Ⅰ组,组织工程骨组;Ⅱ组,空白对照组;Ⅲ组,单纯异种脱蛋白骨组;Ⅳ组,自体髂骨组.术后10周将动物处死做大体观察、手工力学、X线片、CT和组织学检查.结果大体观察、手工力学、X线片及CT检查均显示Ⅰ、...     

不同方法低温保存的组织工程骨修复骨缺损的实验研究

目的探讨不同方法低温保存的组织工程骨修复节段性骨缺损的差异。方法以骨髓基质干细胞（BMSCs）复合部分脱蛋白骨培养制备组织工程骨，组织工程骨分别用添加或不添加冻存保护剂的保存液于-196℃的液氮中冻存3个月，植入实验前复温冻存的组织工程骨。选择60只新西兰白兔，制作15mm长的桡骨节段性骨缺损模型，根据骨缺损区植入不同的材料分为A、B、C和D组，每组15只，A组：植入添加冻存剂保存的组织工程骨；B组：植入未添加冻存剂保存的组织工程骨；C组：植入未行低温保存的组织工程骨；D组：植入部分脱蛋白骨。术后4、8、16周取材，行X线检查、组织学观察、计算机图像分析和生物力学测定。结果术后4、8、16周各组骨缺损区均有新骨生成，成骨量随时间的推移而增加。经X线、组织学和生物力学评估，A组与C组比较差异无统计学意义（P〉0．05），A组或C组分别与B、D组比较，成骨能力依次为：A组或C组〉B组〉D组，差异有统计学意义（P〈0．05），其中A组或C组术后16周骨缺损完全修复，骨髓腔再通，生物力学性能接近正常骨。结论选择适宜的冻存保护剂对组织工程骨的生物活性有一定的保护作用。     

异种脱蛋白皮质骨管复合组织工程骨修复大段骨缺损的实验研究

目的评估异种脱蛋白皮质骨管复合组织工程骨修复大段骨缺损的力学作用及成骨效果。方法 36只成年猪,随机分成3组,实验组植入异种脱蛋白皮质骨管复合骨基质明胶、骨形态发生蛋白及骨膜细胞,对照组植入异种脱蛋白骨皮质骨管复合自体髂骨微粒,空白对照组植入单纯异种脱蛋白骨管,三组均采用锁定钢板及异种皮质骨板固定。通过X线检查、病理组织学、生物力学及灰量测定检查观察骨缺损修复情况。结果术后24周,实验组及对照组骨缺损处新生骨生长良好,骨小梁排列整齐,空白对照组骨缺损新生骨较少,且与断端部分相连。植入后24周实验组与对照组的生物力学及骨矿含量相比无统计学差异,且均明显高于空白对照组。结论异种脱蛋白皮质骨管复合骨基质明胶、骨形态发生蛋白及骨膜细胞修复大段骨缺损具有良好的应力支撑作用,其成骨效果与自体松质骨相当。     

雪旺细胞促进组织工程骨修复大鼠股骨损的实验研究

目的 探讨雪旺细胞(SCs)对β-磷酸三钙/骨髓基质干细胞诱导分化的成骨细胞(β-TCP/BDOB)组织工程骨修复大鼠股骨缺损的影响. 方法 将SD大鼠骨髓基质于细胞(BMSCs)诱导分化为BDOB,并从SD乳鼠中提取SCs.将36只SD大鼠随机分为3组,每组12只,分别将术前预种植SCs的β-TCP/BDOB组织工程骨(A组)、β-TCP/BDOB组织工程骨(B组)、单纯β-TCP材料(C组)植入大鼠体内修复长度为8 mm的股骨缺损.于术后12周行X线摄片、组织学检查和显微CT扫描观察各组股骨缺损部位新生骨质的形成情况. 结果 术后12周X线片和显微CT扫描结果显示:A组大鼠股骨缺损已完全愈合,B组大鼠股骨缺损部分愈合,C组大鼠股骨缺损未愈合.A组、B组、C组的X线影像学评分平均分别为(12.08 ±0.90)、(9.25±1.06)、(6.17±1.12)分,3组比较差异有统计学意义(F=99.553、P=0.000),3组间两两比较差异均有统计学意义(P＜0.05).组织学检查结果显示:A组植入物中有大量骨质形成,广泛分布肥大的软骨细胞与成骨细胞;B组植入物中也可见散在新生骨形成,软骨细胞与成骨细胞散在稀疏分布;C组植入物中新生骨质形成极少,几乎未见软骨细胞或成骨细胞. 结论 SCs可提高β-TCP/BDOB组织工程骨修复大鼠股骨缺损的效果.     

脱蛋白异种骨复合富血小板血浆修复股骨干骨缺损

目的将富血小板血浆与异种脱蛋白骨结合,观察其修复股骨干骨缺损的疗效。方法2次离心取得患者自体富血小板血浆,术前将其与异种脱蛋白松质骨混合,植于股骨干骨折骨缺损处。对照组仅用异种脱蛋白松质骨植骨。术后7d和1、2、3、6、12个月定期摄X线片检查,参照Lane—Sandhu的X线评分标准评分,并比较两组骨痂灰度,比较两组愈合情况及愈合速度。结果两组Lane-Sandhu的X线评分在术后1、2、3、6个月时,差异有显著性（P〈0．05）;而在术后12个月,两组差异无显著性（P〉0．05）。骨痂灰度术后1、2、3、6个月时两组差异有显著性（P〈0.05）。结论富血小板血浆复合异种脱蛋白松质骨可促进和加速骨缺损的修复。     

异种脱蛋白骨管复合不同移植材料修复大段骨缺损的实验研究

目的 应用异种脱蛋白骨管复合骨基质明胶(BMG)、骨形态发生蛋白(BMP)、骨膜细胞与复合脱钙骨基质(DBM)、自体红骨髓(RBM)作比较,观察修复猪大段骨缺损的成骨差异.方法 建立猪双侧胫骨大段骨缺损模型.24只成年猪,随机分成2组,实验组A:异种骨管+BMG、BMP、骨膜细胞;实验组B:异种骨管+DBMLRBM;两组均采用锁定钢板及异种皮质骨板固定.分别于术后4、8、12、24周时通过大体标本观察.放射学及组织学观察评估其修复猪大段骨缺损的成骨情况.结果 植入后24周,异种骨管复合BMG、BMP、骨膜细胞完全修复.成骨活跃程度,骨再生量和重建髓腔结构等方面均显著;复合脱钙骨基质、自体红骨髓成骨能力较弱.结论 异种脱蛋白皮质骨管复合骨基质明胶、骨形态发生蛋白及骨膜细胞能够有效修复大段骨缺损.     

种植转染VEGF165基因骨髓基质细胞的脱蛋白异体骨在裸鼠体内的成骨

目的:探讨脱蛋白骨支架种植转染血管内皮生长因子(vascular endothelial growth factor,VEGF)165基因的骨髓基质细胞体内的成骨作用.方法:从狗的髂骨穿刺骨髓分离骨髓基质细胞,应用脂质体转染VEGF165基因,以RT-PCR检测转染的基因表达.随机选取4周龄BALB/C裸鼠30只,随机分为3组,各组10只.实验组A为脱蛋白骨 转染pcDNA3-hVEGF165基因的骨髓基质细胞;实验组B为脱蛋白骨 骨髓基质细胞;对照组C为单纯植入脱蛋白骨 DMEM.在脊柱两侧分开肌间隙,每只裸鼠植入2块脱蛋白骨材料至肌腹内.术后4、8周处死取材,经大体观察、组织形态学与免疫组化方法检查细胞材料复合物植入后的成骨作用及VEGF表达.结果:组织学检查A、B组均有成骨,并随时间延长而新骨增多,但其中转基因的A组其成骨作用明显,并在植入4周后免疫组化可见VEGF表达呈阳性;对照组C无成骨现象.结论:转染VEGF165基因骨髓基质细胞复合脱蛋白骨在体内具有较好的成骨作用.     

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.