阿仑膦酸钠对假体周围骨溶解中OPG及RANKL的影响

目的 探讨阿仑膦酸钠对聚乙烯颗粒诱导假体周围骨溶解中OPG及RANKL影响.方法 将钛金属棒植入新西兰大白兔左侧股骨内,每2周向左膝关节内注射聚乙烯颗粒,使用随机数字表随机分成实验组和对照组,各6只.实验组给予阿仑膦酸钠灌胃,而对照组给予等量的0.9％的氯化钠溶液灌胃.12周后处死动物,取出假体周围界膜组织,用ELIS...     

载阿仑膦酸钠骨水泥抑制钛磨屑诱导的假体周围骨溶解

目的 比较载阿仑膦酸钠丙烯酸骨水泥与皮下注射阿仑膦酸钠抑制钛磨眉诱导的骨溶解的效果.方法 48只成年雄性新西兰兔随机均分为无钛磨屑且无阿仑膦酸钠组(A组),有钛磨屑注射且无阿仑膦酸钠组(B组),钛磨屑分别注射0.1%、0.5%、1.0%载阿仑膦酸钠丙烯酸骨水泥组(C、I)、E组),钛磨屑注射且皮下手射阿仑膦酸钠组(F组),每组8只.将载阿仑膦酸钠骨水泥植入兔股骨远端.制备磨屑诱导骨溶解动物模型.术后8周对股骨行组织形态学分析、骨密度(bone mineral density,BMD)测定及界面力学测试结果 B组假体周围可见明显的骨溶解,而C、D、E、F组骨溶解明显少于B组.B组假体周围BMD和骨-骨水泥界面抗剪强度分别较A组下降17%和56%;D组假体周围BMD和界面抗剪强度较B组分别增加29%和62%;E组假体周围BMD和界画抗剪强度较B组分别增加37%和29%;F组假体周围BMD和界面抗剪强度较B组分别增加51%和69%;C组、D组、E组分别与F组比较,假体周围BMD和界面抗剪强度的差异均无统计学意义.结论 载阿仑瞵酸钠丙烯酸骨水泥与皮下注射阿仑瞵酸钠均可在一定程度上抑制磨屑诱导的骨吸收,增强界画抗剪强度.     

Micro-CT评价唑来膦酸对磨损颗粒诱导假体周围骨溶解模型的抑制作用

目的 :研究唑来膦酸对磨损颗粒诱导假体周围骨溶解大鼠模型的骨微结构的影响。方法 :选取30只成年雄性SPF级SD大鼠(重250~300 g),随机分成假手术组、模型组和唑来膦酸组,每组10只。通过往大鼠右侧股骨置入钛钉和聚乙烯颗粒进行造模,术后3 d假手术组、模型组皮下注射0.9%生理盐水2 ml/kg,唑来膦酸组皮下注射唑来磷酸0.1 mg/kg,每周1次,共8周。8周后取各组大鼠右侧股骨标本采用Micro-CT对大鼠股骨松质骨微结构进行扫描,应用三维重建处理和分析软件进行处理得到图像及BMD、BV/TV、Tb.N、Tb.Th、SMI、BS/BV、Tb.Sp、Tb.Pf等参数进行分析。结果:Micro-CT三维成像显示,模型组大鼠股骨骨密度较假手术组明显下降,骨微结构破坏严重,骨小梁稀疏变细,连续性降低;唑来膦酸组与模型组比较,骨微结构又出现明显改善。对大鼠股骨微结构的Micro-CT参数进行分析,模型组大鼠股骨BMD(0.081±0.020)明显低于假手术组(0.160±0.018)及唑来膦酸组(0.125±0.012),差异有统计学意义;模型组大鼠股骨BV/TV(10.563±1.070)低于假手术组(27.935±1.834)及唑来膦酸组(14.559±1.258),差异有统计学意义;模型组大鼠股骨Tb.N(1.005±0.165)低于假手术组(2.058±0.108)及唑来膦酸组(1.515±0.126),差异均有统计学意义;模型组大鼠股骨Tb.Th(0.075±0.016)明显低于假手术组(0.158±0.016)及唑来膦酸组(0.124±0.011),差异均有统计学意义。同时,模型组大鼠股骨SMI(1.817±0.127)明显高于假手术组(1.104±0.120)及唑来膦酸组(1.547±0.122),差异均有统计学意义;模型组大鼠股骨BS/BV(35.784±1.650)明显高于假手术组(21.506±2.771)及唑来膦酸组(30.399±2.730);模型组大鼠股骨Tb.Sp(0.735±0.107)高于假手术组(0.423±0.057)及唑来膦酸组(0.577±0.082),差异均有统计学意义;模型组大鼠股骨Tb.Pf(9.088±1.283)明显高于假手术组(2.447±0.703)及唑来膦酸组(5.862±1.042),差异有统计学意义。结论:唑来膦酸可以通过改变大鼠骨微结构达到抑制磨损颗粒诱发的骨溶解的作用,为使用唑类酸作为一种治疗性干预手段来防止假骨溶解提供了科学依据。     

阿仑膦酸钠不同给药时间间隔对磨损颗粒诱导的假体周围骨溶解影响

目的 观察阿仑膦酸钠不同给药时间间隔对磨损颗粒诱导假体周围骨溶解的影响，为临床应用阿仑膦酸钠预防人工关节假体周围骨溶解提供理论依据。方法 雄性SD大鼠12只，经膝关节将钛合金假体及混合磨损颗粒植入胫骨近端（双侧），随机分成实验Ⅰ组和实验Ⅱ组，每组6只，术后分别每日1次空腹阿仑膦酸钠（0．1m∥kg）灌胃和每周1次空腹阿仑膦酸钠（0．7mg／kg）灌胃，持续6周。术后12周处死取材，进行组织学观察及组织形态计量学测定。结果 实验Ⅰ组和实验Ⅱ组假体柄周围纤维界膜均较薄，细胞成分少，假体周围新生骨与假体间可见有直接接触，对假体支撑作用良好。假体周围界膜厚度及面积的形态计量学检测发现，两组间差异无显著性。结论阿仑膦酸钠预防磨损颗粒诱导的假体周围骨溶解时，每周给药1次与每日给药1次可产生同样的效果。     

RANKL/RANK/OPG信号通路参与调控磷酸三钙磨损颗粒诱导假体周围骨溶解的研究

目的探讨RANKL/RANK/OPG信号通路在磷酸三钙磨损颗粒诱导假体周围骨溶解中的作用。方法将30只小鼠随机分为假手术组、模型组和OPG组,制备小鼠颅骨溶解模型,OPG组于术后第2天在颅顶局部注射骨保护素(osteoprotegerin,OPG)(3 mg/kg),每隔2 d 1次;假手术组和模型组给予等量生理盐水,共2周。测定破骨细胞数和骨溶解面积,检测白细胞介素-1β(Interleukin-1β,IL-1β)、白细胞介素-6(Interleukin-6,IL-6)和肿瘤坏死因子-α(tumor necrosis factorα,TNF-α)、OPG、NF-kappa B的受体激活因子(receptor activator of nuclear factor-κB,RANK)和RANK配体(receptor activator of nuclear factor-κB ligand,RANKL)的水平。结果与假手术组比较,模型组小鼠颅骨破骨细胞数、骨溶解面积均增加,IL-1β、IL-6和TNF-α水平均增加,RANKL和RANK mRNA的相对表达量均增加,OPG mRNA的相对表达量降低(P0.05);与模型组比较,OPG组小鼠颅骨破骨细胞数和骨溶解面积减少,IL-1β、IL-6和TNF-α水平减少,RANKL和RANK mRNA的相对表达量均降低,OPG mRNA的相对表达量增加(P0.05)。结论 RANKL/RANK/OPG信号通路参与调控磷酸三钙磨损颗粒诱导假体周围骨溶解,通过给予外源性OPG能显著抑制磷酸三钙磨损颗粒诱导的骨溶解。     

骨保护素和骨保护素配体在假体周围骨溶解中作用的实验研究

目的通过动物实验模拟聚乙烯颗粒诱导假体周围骨溶解,观察骨溶解的组织学反应和界膜内肿瘤坏死因子-α(TNF-α)、骨保护素(OPG)和骨保护素配体(OPGL)的变化,了解上述物质在磨损颗粒诱导假体周围骨溶解中的作用机理。方法实验选用SPF级雄性SD大鼠24只,经双侧膝关节向股骨远端植入钛合金棒,术后2、4、6、8、10周分别向左侧膝关节注入聚乙烯颗粒,右侧注射生理盐水作为对照,术后12周处死动物取材,观察界膜的组织学改变、TNF-α的浓度和OPG、OPGL的mRNA含量变化。所得数据选用配剥t检验进行统计学分析。结果注射颗粒侧钛合金棒周围有明显界膜形成,界膜中的TNF-α也有明显增高。RT-PCR半定量分析发现,注射颗粒侧界膜组织中OPG mRNA水平低于对照侧,而OPGL mRNA水平则高于对照侧(P＜0．05)。结论聚乙烯颗粒可引起钛合金棒周围多种细胞参与的异物肉芽肿反应,成骨细胞/骨髓基质细胞OPGL的合成增加而OPG的合成减少,此过程可能与TNF-α的升高有关。     

槲皮素调控MAPK通路对绝经后骨质疏松大鼠骨形成的影响

目的 探讨槲皮素调节MAPK信号通路对绝经后骨质疏松大鼠模型骨形成的影响。方法 将SPF级SD雌性大鼠分为假手术组、模型组、槲皮素低、高剂量组及补佳乐组。通过ELISA法检测大鼠血清雌激素E2水平、骨代谢标志物CBF-α1、CTX-Ⅰ、PINP、OC水平、炎性指标IL-6、TNF-α、IL-1β水平;HE染色观察大鼠骨组织形态学变化;TRAP染色观察N.Oc/BS;显微CT扫描大鼠股骨形态,测定大鼠股骨BMD、Tb.N、Tb.Th、Tb.Sp; WB检测MAPK信号通路相关蛋白表达。结果 与假手术组相比,模型组大鼠血清E2、CBF-α1、CTX-Ⅰ、PINP、OC水平降低,IL-6、TNF-α、IL-1β水平增加,N.Oc/BS增加,BMD、Tb.N、Tb.Th降低,Tb.Sp增大(P<0.05);与模型组相比,槲皮素低、高剂量组及补佳乐组大鼠血清E2、CBF-α1、CTX-Ⅰ、PINP、OC水平增加,IL-6、TNF-α、IL-1β水平降低,N.Oc/BS降低,BMD、Tb.N、Tb.Th增高,Tb.Sp减小(P<0.05)。假手术组骨组织形态结构正常;模型组骨皮质厚度变...     

阿伦膦酸钠防治人工关节松动的实验研究

目的：评价二膦酸盐阿伦膦酸钠在防治人工关节松动中的作用。方法：36只SD大鼠右膝置入自制人工关节假体,建立人工关节松动的动物模型,分成3组：阴性对照组,阳性对照组和实验组。阴性对照组关节腔内注射磷酸缓冲液与鼠血清混合液,阳性对照组关节腔内注射10^10/ml关节磨屑（超高分子聚乙烯颗粒）,实验组关节腔内注射10^10/ml关节磨屑同时用阿伦膦酸钠灌胃（每日1mg/kg）。术后12周,处死各组动物行组织切片对比观察假体周围骨溶解情况。体外分离培养人外周血单个核细胞并分成5组,A组为单核细胞组,B组为单核细胞和关节磨屑混合培养组,C组为单核细胞和关节磨屑混合培养加入10^-4mol/L阿伦膦酸钠,D组单核细胞和关节磨屑混合培养加入10^-5mol/L阿伦膦酸钠,E组为单核细胞和关节磨屑混合培养加入10^-6mol/L阿伦膦酸钠,检测各组单个核细胞分泌溶骨因子的情况。结果：关节磨屑可引起假体周围骨溶解,刺激单个核细胞分泌溶骨因子,阿伦膦酸钠可阻止这种作用。结论：阿伦膦酸钠可有效防止关节磨屑诱导的人工关节松动,有望用于临床。     

阿仑膦酸钠预防磨损颗粒诱导假体周围骨溶解的作用机制

目的 目的是利用阿仑膦酸钠来研究其对人工关节假体周围骨溶解的影响及其作用机制。方法 体重300～350g的雄性SD大鼠24只，经膝关节将特制的钛合金假体及混合磨损颗粒植入胫骨近端（双侧），随机分为实验组和对照组，每组12只，术后分别每日空腹阿仑膦酸钠（0.1mg／kg体重）灌胃和生理盐水2ml灌胃，共6周。术后12周处死取材，进行组织学观察及组织形态计量学测定，并采用ELISA法及半定量RT—PCR检测假体周围组织中TNF-α的的含量及OPGL／OPG含量的比率。结果 组织学观察发现，对照组假体柄周围纤维界膜厚、细胞成分多。可分3层：紧贴假体处为疏松结缔组织，稍外为致密纤维结缔组织。最外层含有单核细胞、巨噬细胞及异物巨细胞。与纤维界膜连接处新生骨边缘呈虫蚀状，新生骨与假体接触少。对假体的支撑作用差。实验组假体周围纤维界膜较薄、细胞成分少，多为成纤维细胞。新生骨与假体间呈点状接触。对假体有明显的支撑作用。形态计量学检测发现，两组间假体周围界膜厚度及面积差异有统计学意义；ELISA和半定量RT—PCR检测假体周围组织中TNF-α及OPGL／OPG发现。两组间差异有统计学意义。结论 阿仑膦酸钠不仅可直接作用于假体周围组织的中破骨细胞。同时可通过调节假体周围组织分泌TNF-α、OPGL、OPG等的含量来调节破骨细胞的分化、成熟及增殖。     

SCID小鼠单次唑来磷酸头皮下注射抑制人假体周围骨溶解

[目的]评价唑来磷酸在新型动物模型中对人关节假体周围界膜组织诱导的骨溶解的抑制效应。[方法]将髋关节翻修病人体内获得的界膜组织移植到SCIDbeige小鼠颅骨上。术后2d将唑来磷酸直接注射至小鼠头皮下,并在术后2、4周处死动物取出带移植组织的颅骨进一步检测。[结果]移植组织在动物体内存活至少4周,HE染色可见界膜组织引起大量的骨胶原纤维碎裂溶解。界膜组织中TNF-α、IL-6、RANKL和CPK的基因表达和蛋白水平均显著高于对照。单次局部注射唑来磷酸显著降低RANKL和CPK的表达但未影响TNF-α和IL-6的水平。[结论]单次局部注射唑来磷酸可有效抑制人界膜组织诱导的骨溶解,且效应持续。该新型动物模型模拟临床程度高,可作为评价假体周围骨溶解药物抑制效应的平台。     

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 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.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

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.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.