阿伦膦酸钠对骨髓生成破骨细胞及骨吸收作用的影响

[目的]研究阿伦膦酸钠对体外培养的小鼠骨髓生成破骨细胞及其骨吸收作用的影响。[方法]收集小鼠骨髓细胞于含有10^-8mol／L的1，25二羟基维生素D3[1，25-（OH）2D3]的α-MEM完全培养基中体外培养，设置不同浓度的阿伦膦酸钠给药，并于培养的第6、9、12d观察记录抗酒石酸酸性磷酸酶（tartrate-resistant acidphosphatase，TRAP）阳性多核巨细胞[破骨样细胞（osteoclast-like cell，OLC）]生成数，反映破骨细胞生成情况。记数培养12d骨磨片上骨吸收陷窝数及吸收面积，反映骨吸收情况。[结果]随着阿伦膦酸钠浓度的增高，TRAP阳性的细胞数减少，骨吸收陷窝数及面积均减少。[结论]阿伦膦酸钠可抑制骨髓细胞体外培养中破骨样细胞的形成，体外可抑制破骨细胞骨吸收作用。     

1，25-二羟基维生素D3对小鼠骨髓细胞形成破骨细胞样细胞及其骨吸收效应的影响

目的动态观察1,25-二羟基维生素D3[1,25-(OH)2D3]对NH小鼠骨髓细胞培养在体外形成破骨细胞及其骨吸收的剂量效应和作用时象.方法收集NH小鼠骨髓细胞于含10%胎牛血清的α-MEM培养基中行体外培养,设置不同的1,25-(OH)2D3浓度组和给药时间组,并于培养第3、6、9、12天观察记录抗酒石酸酸性磷酸酶(tartrate-resistant acid phosphatase,TRAP)阳性多核巨细胞[或破骨细胞样细胞(osteroblast-like cell,OLC)]以及骨磨片上骨吸收陷窝的数目.结果高于10-9mmol/L的1,25-(OH)2D3单一刺激可于培养第6天诱导TRAP阳性OLC形成,并且可在骨磨片上观察到骨吸收陷窝;随1,25-(OH)2D3浓度的增高,OLC和骨吸收陷窝数目均随之增加;各浓度组OLC数目于培养第9天达最高值,随后则趋于减少,而骨吸收陷窝数于培养第9和第12天均有所增加;采用单一1,25-(OH)2D3浓度(10-8mmol/L),TRAP阳性OLC和骨吸收陷窝见于培养3 d后用药和全程用药组,而仅在培养前3 d用药则不能诱导OLC和骨吸收陷窝的形成.结论 1,25-(OH)2D3可在体外诱导骨髓单核细胞分化形成OLC并使其具有破骨活性,诱导作用的强弱与1,25-(OH)2D3的浓度相关,而且其作用时象可能是在培养3 d以后.     

辛伐他汀对PTHrP诱导的破骨细胞性骨吸收及小鼠颅盖骨代谢的影响

[目的]探讨辛伐他汀对体外甲状旁腺素相关肽（PTHrP）诱导小鼠的破骨细胞骨吸收功能的作用及其小鼠骨代谢的影响。[方法]采用PTHrP诱导小鼠骨髓细胞培养破骨细胞和小鼠颅盖骨培养体系，检测辛伐他汀作用8d后破骨细胞骨吸收陷窝和培养上清钙的变化；检测小鼠颅盖骨培养上清碱性磷酸酶和钙含量，组织学观察小鼠颅盖骨形态学变化。[结果]辛伐他汀体外可明显抑制PTHrP诱导小鼠的破骨细胞骨吸收陷窝的形成及培养上清钙的释放，辛伐他汀体外可增强小鼠颅盖骨培养上清碱性磷酸酶的活性，组织学观察到辛伐他汀使小鼠颅盖骨矿化增强。[结论]辛伐他汀体外不仅可促进小鼠颅盖骨的成骨活性，并且可明显抑制PTHrP诱导小鼠的破骨细胞骨吸收功能，对骨吸收性疾病有着重要的防治作用。     

淫羊藿苷对破骨细胞活性的影响

目的:观察淫羊藿苷对破骨细胞骨吸收及凋亡的影响,探讨淫羊藿苷的抗骨质疏松作用机制。方法:体外分离、培养兔破骨细胞,与玻片及骨磨片共同培养,用10-7、10-6、5×10-6、10-5mol/L浓度的淫羊藿苷刺激破骨细胞,倒置相差显微镜下观察活体细胞、HE染色、TRAP染色及骨吸收陷窝甲苯胺蓝染色,鉴定破骨细胞,并进行骨吸收陷窝计数和面积测量,吖啶橙染色观察凋亡破骨细胞所占的比例。结果:与空白对照组比较,10-6、5×10-6、10-5mol/L浓度的淫羊藿苷组破骨细胞凋亡率均明显增高,骨吸收陷窝数目、面积明显减少,随浓度增加抑制作用增强,差异有显著性意义(P<0.05)。结论:淫羊藿苷可诱导破骨细胞凋亡,抑制骨吸收,并随浓度增加抑制作用增强。     

阿司匹林对大鼠破骨细胞分化成熟和骨吸收活性的影响

目的 研究不同浓度阿司匹林对体外培养大鼠破骨细胞(Osteoclast,OC)分化成熟及骨吸收活性的影响.方法 建立由核激活因子受体配体(receptor activator of NF-κB ligand,RANKL)和巨噬细胞集落刺激因子(Macrophage colony stimulating factor,M-CSF)共同作用的大鼠破骨细胞骨髓诱导体系,将雌激素(10-6 mmol/L)和不同浓度的阿司匹林(0.25 mmol/L、0.5 mmol/L、1.0 mmol/L、1.5 mmol/L)分别作用于破骨细胞.诱导培养后分别对破骨细胞进行抗酒石酸酸性磷酸酶(The tartrate-resistant acid phosphatase,TRAP)染色,观察细胞形态,并计数破骨样细胞数量;将各组破骨细胞接种于骨磨片上,建立破骨细胞-骨磨片活性分析模型,于不同时间点对骨磨片进行光镜和扫描电镜观察,分析计算骨吸收陷窝面积.结果 与正常对照组相比,雌激素组破骨细胞数量和骨吸收陷窝面积低于正常对照组,差异有统计学意义(P＜0.05);且随着阿司匹林浓度的增加,阿司匹林组TRAP阳性多核破骨细胞数量、骨吸收陷窝面积逐渐减少直至消失,差异有统计学意义(P＜0.05).与雌激素组相比,低浓度阿司匹林组(0.25mmol/L)没有明显差异;但中、高浓度阿司匹林实验组(0.5mmol/L、1.0mmol/L、1.5mmol/L)破骨细胞数量和骨吸收陷窝面积减少,差异有统计学意义(P＜0.05).结论 阿司匹林对破骨细胞的分化成熟及骨吸收功能有抑制作用,且呈剂量依赖性,从而具有抗骨质疏松的作用.     

不同氧环境中破骨细胞的发育分化和功能变化研究

目的 本实验拟观察不同氧浓度下破骨细胞诱导过程中的分化发育,寻找破骨细胞体外培养的适宜氧浓度,为骨转换平衡的修复提供依据.方法 取野生型C57B/L小鼠(2个月龄左右,雄性)骨髓进行破骨细胞的诱导培养.用RANKL(10ng/ml)和M-CSF(10ng/ml)联合的诱导方案,将小鼠骨髓中单核-巨噬细胞系体外诱导为破骨细胞样细胞.将原代破骨细胞置于20%O2、7%O2、2%O2下诱导培养,MOCP5不同氧浓度下普通培养.用MTT法检测MOCP5的增殖变化,用抗酒石酸酸性磷酸酶(TRAP)染色检测破骨细胞形成的变化,并进行TRAP阳性细胞计数,用象牙骨片骨吸收陷窝甲苯胺蓝染色检测破骨细胞骨吸收活性的变化.结果 骨髓中单核-巨噬细胞体外经RANKL和M-CSF联合诱导可分化为多核的破骨细胞样细胞,在诱导第3天细胞开始融合,第5天TRAP染色强阳性,第8天可见象牙骨片上形成圆形、椭圆形、腊肠形等多种形态的骨吸收陷窝.MTT检测显示MOCP5在20%O2培养时一直处于增殖状态,7%O2条件下由增殖期进入平台期,2%O2时增殖缓慢且没有规律.20%O2、7%O2、2%O2培养下形成的TRAP阳性破骨细胞数分别为22±5.97、34±2.97、7±1.39(P<0.05),原代诱导的破骨细胞在20%O2、7%O2、2%O2形成的骨吸收陷窝面积(μm2)分别为3892.28±1642.78、5356.7±1655.6、2573±994.48(P<0.05).结论 体外RANKL和M-CSF联合可将骨髓单核-巨噬细胞诱导成多核的破骨细胞样细胞作为破骨细胞的研究模型.常氧条件下破骨细胞的TRAP阳性细胞数和骨吸收活性均低于7%O2.7%O2培养下的破骨细胞更接近于体内生理状态的破骨细胞.     

降钙素基因相关肽对大鼠骨髓单核巨噬细胞破骨分化作用的实验研究

目的 通过体外实验研究外源性降钙素基因相关肽（calcitonin gene-related peptide,CGRP)对大鼠骨髓单核巨噬细胞 (BMMs)破骨分化能力的影响,为CGRP在抗骨质疏松治疗方面的应用提供理论依据。方法 采用差速贴壁的方法分离出SD大鼠髓腔内单核巨噬细胞,原代培养并传代,在培养体系中添加含不同浓度CGRP (实验组：10–7 mol/L、10–8 mol/L、10–9 mol/ L;对照组：无CGRP)的破骨诱导液,对前体细胞进行破骨诱导7天后进行相关实验检测,分别采用抗酒石酸酸性磷酸酶染色(TRAP染色）观察破骨细胞的生成能力;用RT-PCR方法检测破骨细胞系特征性基因（RANK、TRAP、NFATc1); Western-blot检测破骨特征性TRAP和RANK蛋白的表达;骨磨片甲苯胺蓝染色检测诱导的破骨细胞的骨吸收功能。结果TRAP染色显示 CGRP各浓度组镜下成熟破骨细胞的个数显著低于对照组,有统计学差异(P <0.05)并随CGRP浓度的增高成熟破骨细胞数减少,CGRP组间亦差异明显(P <0. 05);RT-PCR检测破骨特征性RANK、TRAP、NFATc1 mRNA和Westem-blot测破骨特征性TRAP、RANK蛋白的表达各CGRP组均低于对照组(P < 0. 05);骨磨片破骨细胞甲苯胺蓝染色后单倍视野下CGRP组破骨陷窝数量也明显少于对照组(P < 0. 05),且与药物组浓度与陷窝数量呈负相关性。结论 CGRP能够抑制BMMs向破骨方向的分化,为CGRP抗骨质疏松的治疗提供理论支持。     

重组人骨保护素与重组核因子κb活化因子受体蛋白对破骨前体细胞分化的影响

目的:对比重组人骨保护素(rhOPG-Fc)与重组核因子κb活化因子受体蛋白(rhRANK)对破骨前体细胞分化的影响.方法:采用成骨细胞与破骨前体细胞RAW264.7混合培养,在地塞米松、1,25 (OH) 2VitD3诱导下生成破骨细胞的方法.研究分3组:rhRANK组:10-5 g/L;rhOPG-Fc组:10-5 g/L;空白对照组.作用9d后观察破骨细胞数目和形态,抗酒石酸酸性磷酸酶(TRAP)染色阳性细胞个数,骨磨片吸收陷窝计数.结果:在空白对照组,小鼠成骨细胞与破骨前体细胞RAW264.7混合培养6d后,开始出现多核细胞,9d时可见大量成熟多核细胞,经TRAP染色证实为成熟破骨细胞,而rhRANK组及rhOPG-Fc组TRAP染色阳性多核细胞数较对照组均减少,特别是rhRANK组减少更明显.骨片吸收陷窝计数显示rhRANK组及rhOPG-Fc组较对照组也明显减少,而相对来说,rhRANK组较rhOPG-Fc组更少.结论:rhOPG-Fc与rhRANK均可以有效抑制破骨前体细胞分化成为成熟破骨细胞,且rhRANK较rhOPG-Fc抑制效果更明显.     

骨水泥颗粒促进肿瘤坏死因子α诱导的破骨细胞形成及其骨吸收作用

目的:验证骨水泥颗粒对肿瘤坏死因子α(TNFα)诱导的破骨细胞形成及其生物学活性的影响。方法:体外培养外周血单核细胞,对照组加入TNFα和白细胞介素-1α(IL-1α)及巨噬细胞克隆集落刺激因子(M-CSF),实验组并分别加入含有或不含有硫酸钙的骨水泥(PMMA±BaSO4)颗粒。对培养终末细胞作组织化学染色检测破骨细胞标志物抗酒石酸酸性磷酸酶(TRAP)的表达,并以象牙磨片上虫蚀样骨吸收陷窝的形成为指标检测破骨细胞的生物学活性;并比较各实验组中TRAP阳性多核细胞(multinucleatedcells,MNCs)及虫蚀样骨吸收陷窝形成时间的早晚。结果:各组TRAP阳性MNCs的数量无明显差异;PMMA±BaSO4组象牙磨片上骨吸收陷窝的面积均较对照组大,差异具有显著性(P<0.01);并且PMMA±BaSO4组TRAP阳性的MNCs及虫蚀样骨吸收陷窝的形成均较对照组早。结论:PMMA±BaSO4颗粒能够促进TNFα诱导的破骨细胞分化提早发生并促进其骨吸收活性。     

辛伐他汀对钛颗粒刺激人单核细胞形成破骨细胞的影响

目的研究体外辛伐他汀对钛颗粒刺激单核细胞形成破骨细胞的影响,探讨辛伐他汀防治人工关节无菌性松动的可能性。方法体外分离培养人外周血单个核细胞并分成5组,A组为钛颗粒刺激组（单核细胞和磨屑混合培养）,B组为10^-5mol／L辛伐他汀组（单核细胞、磨屑混合培养＋10^-5mol／L辛伐他汀）,C组为10^-6mol／L辛伐他汀组（单核细胞、磨屑混合培养＋10^-6mol／L辛伐他汀）,D组为10^-7mol／L辛伐他汀组（单核细胞、磨屑混合培养＋10^-7mol／L辛伐他汀）,E组为单核细胞组。各组细胞培养24h后取上清液,用ELISA法检测上清液中肿瘤坏死因子（TNF-α）、单核细胞趋化蛋白-1（MCP-1）的含量。分别培养10d、18d后进行TRAP染色阳性细胞计数,采用扫描电镜检测骨磨片的吸收陷窝,观察钛颗粒对破骨细胞形成的影响。结果磨屑刺激单个核细胞分泌溶骨因子,辛伐他汀抑制磨损颗粒刺激单核／巨噬细胞分泌TNF-α及MCP-1;且破骨细胞数明显减少,骨吸收陷窝数减少,与钛颗粒组刺激组比较,差异均有统计学意义（P〈0．05）。结论辛伐他汀通过抑制TNF-α、MCP-1的释放而有效防止磨屑诱导的骨溶解,有望成为防治人工关节无菌性松动的一种有潜力的药物。     

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.     

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.     

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.     

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.     

The analgesic effect of racemic ketamine in patients with chronic ischemic pain due to lower extremity arteriosclerosis obliterans

Background : Ketamine in sub-dissociative doses has been shown to have analgesic and phantom-Limb pain, where conventional treatment has often failed. Chronic ischemic pain due to lower extremity arteriosclerosis obliterans often responds poorly to analgesics, and the pain-generating mechanisms are not well understood.
Methods : Eight patients with rest pain in the lower extremity due to arteriosclerosis obliterans were given sub-dissociative doses of 0.15, 0.30, or 0.45 mg/kg racemic ketamine and morphine 10 mg as a 5-min infusion on four separate days in a cross-over, double-blind, randomised protocol. Plasma levels of (S)- and (R)-ketamine and their nor-metabolites were analysed with an enantioselective high-performance liquid chromatography (HPLC) method. Pain levels were evaluated with a visual analogue scale (VAS).
Results : Individual pain levels were highly variable during and after all the infusions but the pooled pain levels showed a dose-dependent analgesic effect of ketamine with a transient but complete pain relief in all patients at the highest dose (0.45 mg/ kg). Side-effects, mainly disturbed cognition and perception, were pronounced and dose-dependent. Morphine 10 mg had an analgesic peak at 20 min and 5/8 patients had complete pain relief. The remaining 3 patients also had high baseline pain scores, indicating a higher analgesic potency for the 0.30 and 0.45 mg/ kg ketamine doses than for morphine 10 mg.
Conclusion : We have demonstrated a potent dose-dependent analgesic effect of racemic ketamine in clinical ischemic pain. Due to a narrow therapeutic window, this analgesic effect is probably best utilised in combination with other analgesics.