淫羊藿次苷Ⅰ及淫羊藿次苷Ⅱ通过BMP/Runx2/Osx信号通路促进大鼠骨髓间充质干细胞成骨分化的实验研究

目的观察淫羊藿次苷Ⅰ及淫羊藿次苷Ⅱ对大鼠骨髓间充质干细胞(bone marrow stromal cells,BMSCs)成骨分化过程中BMP-2/Runx2/Osx信号通路的影响,探讨其可能的作用机制。方法贴壁筛选法体外培养BMSCs,随机分为空白对照组、阳性转化液组、抑制剂组、淫羊藿次苷Ⅰ组及淫羊藿次苷Ⅰ+抑制剂组、淫羊藿次苷Ⅱ组及淫羊藿次苷Ⅱ+抑制剂组。通过茜素红染色,对各组促进骨髓间充质干细胞向成骨细胞分化作用进行药效学评价; ELISA法检测各组ALP活性、BGP、COL-Ⅰ、BMP2蛋白分泌量;RTReal-TimePCR法检测各组ALP、BGP、Osterix和Runx-2 mRNA基因表达。结果茜素红染色结果表明,淫羊藿次苷Ⅰ组及淫羊藿次苷Ⅱ组均可明显观察到大量的矿化结节的形成;ELISA实验结果表明,与空白对照组比较,淫羊藿次苷Ⅰ及淫羊藿次苷Ⅱ均能明显促进ALP细胞活性及BGP、COL-Ⅰ、BMP-2蛋白分泌量,并且差异具有统计学意义(P0.05);两组药物作用强度均已达到阳性转化液组的80%以上。同时,淫羊藿次苷Ⅰ对ALP活性、 BGP蛋白表达均明显强于淫羊藿次苷Ⅱ,并且差异具有统计学意义(P0.05);对COL-Ⅰ、BMP-2的蛋白表达量,两者差异无统计学意义(P0.05)。RT-PCR实验结果表明,与空白对照组相比,淫羊藿次苷Ⅰ及淫羊藿次苷Ⅱ均可显著上调成骨相关转录因子ALP、BGP、RunX2,并进一步调节其下游基因Osterix的转录表达,差异具有统计学意义(P0.05);与阳性对照液组比较,淫羊藿次苷Ⅱ对ALP、Osterix的mRNA表达无明显差异(P0.05);淫羊藿次苷Ⅰ与淫羊藿次苷Ⅱ组比较,淫羊藿次苷Ⅱ对Osterix mRNA的表达明显强于淫羊藿次苷Ⅰ,并且差异具有统计学意义(P0.05)。对ALP、BGP、RunX2 mRNA的表达二者无显著性差异(P0.05)。结论淫羊藿次苷Ⅰ和淫羊藿次苷Ⅱ均能促进BMSCs定向成骨转化,其作用机制可能与激活BMP/Runx2/Osx信号通路有关。淫羊藿次苷Ⅰ和淫羊藿次苷Ⅱ作用差异可能与淫羊藿次苷Ⅰ在体内生物转化为淫羊藿次苷Ⅱ有关。     

淫羊藿苷含药血清对体外培养大鼠颅骨成骨细胞增殖与分化的影响

目的 研究淫羊藿苷含药血清(Serum of rats administered icariin,SI)对体外培养大鼠颅骨成骨细胞(Rat calvarial osteoblasts,ROB)增殖和分化成熟的影响.方法 以每1 kg体重0.25 g淫羊藿苷的剂量灌服成年大鼠制得淫羊藿苷含药血清,以灌服等体积生理盐水制得对照血清.分别以2.5%,5%和10%3种浓度加入ROB培养基,检测对成骨细胞增殖、碱性磷酸酶(ALP)活性和钙化结节数等的影响.结果 2.5%和5%SI均促进细胞的增殖,尤以5%浓度更为明显,该浓度含药血清提高ROB的ALP活性,增加Ⅰ型胶原表达,并显著提高钙化结节形成数量.结论 淫羊藿经口服后的代谢产物可刺激成骨细胞增殖,促进其分化成熟,是淫羊藿抗骨质疏松的有效成分.     

淫羊藿苷对人成骨细胞增殖及OPG蛋白表达的实验研究

目的：建立体外培养人成骨细胞系,观察淫羊藿苷对人成骨细胞增殖的影响,以及对人成骨细胞内骨保护素（Osteoprorotegerin,OPG）蛋白表达的影响,探讨淫羊藿苷促进人成骨细胞骨形成的可能作用机制。方法：将手术中取得的人股骨头松质骨骨片,使用酶消化法进行培养,取生长良好的第3代人成骨细胞进行实验。实验分为4组,对照组给予15%NCS-DMEM-F12（1：1）培养液培养;淫羊藿苷组分别于正常培养液内添加终浓度为10-6、10-8、10-10mol/L淫羊藿苷。噻唑蓝比色法（MTT）分别在培养1、3、5、7、9d后观察各组人成骨细胞的增殖情况,用蛋白免疫印迹方法（in-cell western blot）测定各组培养8、10、12d后人成骨细胞内OPG蛋白的表达情况。采用重复测量的方差分析方法,比较各组间在不同时间点的作用差异。结果：MTT结果,淫羊藿苷组具有促进人成骨细胞增殖的作用,并呈明显的量效关系,即随着淫羊藿苷浓度的增高,其促人成骨细胞增殖的能力增强,以10-6mol/L淫羊藿苷组（0.402±0.033）促成骨细胞增殖的作用最显著,与对照组（0.268±0.031）比较差异有统计学意义（P〈0.05）。在时效关系的研究中,随着培养天数的延长,人成骨细胞的量逐渐增加,人成骨细胞于第5天时进入快速生长期,第7天进入平台期;淫羊藿苷组从第5天开始促进人成骨细胞的增殖,第7、9天仍然具有明显的促成骨细胞增殖的作用,以第9天促增殖作用最强。其中,第9天10-6mol/L淫羊藿苷组（0.402±0.033）与对照组（0.268±0.031）比较有统计学意义（P〈0.01）。OPG表达结果,对照组人成骨细胞培养至第8天时检测到OPG蛋白的表达,表达量为1.01±0.08,第12天达到表达高峰为1.80±0.10,两个值比较有统计学差异（P〈0.05）;在观察的不同天数内,不同浓度的淫羊藿苷组人成骨细胞内OPG蛋白表达低于对照组,且随着淫羊藿苷浓度的降低,OPG蛋白的表达量逐渐降低,差异有统计学意义（P〈0.05）;干预12d,10-6mol/L淫羊藿苷组OPG量（1.67±0.13）和10-8mol/L淫羊藿苷组OPG量（1.64±0.05）比较,无统计学差异（P〉0.05）。结论：淫羊藿苷促人成骨细胞骨形成能力的作用途径之一,是通过提高人成骨细胞的增殖能力而实现。     

葛根素和淫羊藿甙对成骨细胞生物学作用的比较研究

目的 对比葛根素和淫羊藿甙对成骨细胞增殖和分化的影响。方法 将小鼠骨髓基质干细胞定向诱导分化为成骨细胞，取第3、4代细胞，以rhBMP-2为阳性对照，MTT法观察葛根素和淫羊藿甙对成骨细胞的增殖作用，碱性磷酸酶（ALP）比活性测定及钙结节计数观察葛根素和淫羊藿甙对成骨细胞分化的影响。结果 20μg／ml的淫羊藿甙可显著促进成骨细胞的增殖；20μg／ml淫羊藿甙及50μg／ml葛根素均能提高成骨细胞的碱性磷酸酶活性，并使矿化结节的形成明显增多。结论 淫羊藿甙不仅能促进成骨细胞的分化，还能增强其增殖能力，而葛根素主要是通过刺激分化来增强成骨细胞的活力。     

淫羊藿总黄酮和戊酸雌二醇对骨质疏松症大鼠TGF-β1/Smads信号通路的影响

目的 研究淫羊藿总黄酮和戊酸雌二醇对骨质疏松症大鼠TGF-β1/Smads信号通路的影响。方法 75只雌性SD大鼠随机分为假手术组（Sham组）、模型组（Model组）、淫羊藿总黄酮组（TFE组）、戊酸雌二醇组（E2V组）、淫羊藿总黄酮联合戊酸雌二醇组（TFE+E2V组）,行双侧卵巢切除术造模,术后12周开始给予相应的药物干预12周。分别检测血清骨代谢指标,BMD和骨灰重比,骨骼生物力学参数,股骨形态计量学参数,股骨TGF-β1/Smads蛋白和mRNA表达。结果 模型组血清Ca、P、OC、PINP,股骨和椎体骨密度、灰重比,股骨最大载荷、最大位移、最大应力、弹性模量,股骨Tb.Ar、Tb.Th、Tb.N,股骨TGF-β1、Smads2蛋白和mRNA表达较Sham组均显著降低（P＜0.01）,E2V组、TFE组、TFE＋E2V组上述指标较模型组均显著增加（P＜0.05）,TFE＋E2V组上述指标较E2V组、TFE组均显著增加（P＜0.05）。模型组血清ALP,股骨Tb.Sp、Oc.N较Sham组显著增加（P＜0.01）,E2V组、TFE组、TFE＋E2V组上述指标较模型组均显著降低（P＜0.05）,TFE＋E2V组上述指标较E2V组、TFE组均显著降低（P＜0.05）。结论 淫羊藿总黄酮联合戊酸雌二醇通过上调TGF-β1、Smad2表达,调节骨质疏松大鼠骨代谢,增加骨量,提高骨密度和骨强度,从而起到抗骨质疏松作用。     

淫羊藿和女贞子配伍对绝经后骨质疏松症大鼠TGF-β1/Smads信号通路的实验研究

目的 研究淫羊藿和女贞子配伍对绝经后骨质疏松症（postmenopausal osteoporosis,PMOP）大鼠转化生长因子（transforming growth factor,TGF）-β1/Smads信号通路的影响。方法 将48只SPF级8月龄雌性SD大鼠,随机分为假手术组、模型组、淫羊藿组、女贞子组、淫羊藿和女贞子配伍组（配伍组）、雷洛昔芬组。对大鼠行双侧卵巢切除术造模,术后1周开始给予相应的药物治疗至术后13周结束。运用酶免法检测血清TGF-β1含量、蛋白免疫印迹法（western blot,WB）和免疫荧光法（immunofluorescence staining,IF）检测骨组织中TGF-β1、p-Smad2/3和Smad7蛋白表达,通过实时荧光定量PCR（quantitative real-time PCR,qRT-PCR）法检测骨组织中TGF-β1、Smad2、Smad3和Smad7 mRNA的表达。结果 与模型组比较,淫羊藿、女贞子配伍组能增加大鼠血清TGF-β1含量（P<0.05）,上调骨组织中TGF-β1、Smad2、Smad3的mRNA表达和TGF-β1、p-Smad2/3的蛋白表达（P均< 0.01）,下调骨组织中Smad7的mRNA和蛋白表达（P均< 0.01）,且配伍组对上述指标的调节作用优于淫羊藿或女贞子单用。结论 淫羊藿和女贞子配伍可以调节PMOP大鼠TGF-β1/Smads信号通路中细胞因子的表达,从而调节骨代谢。     

淫羊藿苷介导MAPK信号通路防治骨质疏松的研究进展

骨质疏松症(osteoporosis,OP)是以骨含量降低、骨密度下降、骨微结构破损、易发骨折为特征的骨科疾病,目前OP治疗主要以西药治疗为主,但疗效并不理想,所以有待进一步寻找根治OP的药物治疗方案。随着传统医学对OP研究的不断深入,发现淫羊藿苷可通过MAPK信号通路促进骨形成、改善骨代谢平衡、增加骨密度等,进而发挥抗OP作用。因此,本文将淫羊藿苷与MAPK信号通路相结合,以促进成骨细胞增殖分化、抑制破骨细胞分化、促进骨髓间充质干细胞成骨分化为治疗靶点综述淫羊藿苷介导MAPK信号通路防治骨质疏松的研究进展,以期为今后临床治疗OP提供新思路。     

MAPK信号通路在淫羊藿甙促进成骨细胞Cbfa1蛋白表达中的作用

目的 观察淫羊藿甙对体外培养大鼠成骨细胞丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)信号通路的影响以及MAPK信号通路在淫羊藿甙促成骨细胞核心结合因子α1(core binding factor-1,Cbfa1)蛋白表达中的作用,以探讨淫羊藿甙对成骨细胞作用的信号传导机制.方法 用酶消化法分离24 h内新生SD大鼠颅盖骨成骨细胞,进行原代培养.在培养液中加入淫羊藿甙(10 ng/mL),作用于成骨细胞5 min、10 min、30 min、60 min,抽提总蛋白,用Western blot法检测细胞中ERK、p-ERK、P38和p-P38蛋白的表达.用雌二醇(10-8 mol/L)作用于成骨细胞5 min、10 min、30 min,同上法检测细胞中ERK、p-ERK、P38和p-P38蛋白的表达.用淫羊藿甙(10 ng/mL)、雌二醇(10-8 mol/L)和u0126或SB203580单独或共同干预成骨细胞24 h,抽提核蛋白,用Western blot法检测Cbfa1蛋白的表达.结果 ①淫羊藿甙作用于成骨细胞,30 min时可促进ERK蛋白的磷酸化,并可持续至60 min,和空白组比较,差异有显著性(P<0.05);淫羊藿甙作用于成骨细胞,5 min时即可促进P38蛋白的磷酸化,在30 min时达高峰,并可持续至60 min,和空白组比较,差异有显著性(P<0.05).②雌二醇作用于成骨细胞,在30 min时可促进ERK蛋白的磷酸化,和空白组比较,差异有显著性(P<0.05);雌二醇作用于成骨细胞,在10 min时可促进P38蛋白的磷酸化,并可持续至30 min,和空白组比较,差异有显著性(P<0.05).③淫羊藿甙和雌二醇均能促进成骨细胞中Cbfa1蛋白的表达,和空白组相比,差异有显著性(P<0.05).u0126和SB203580可以抑制淫羊藿甙和雌二醇促进Cbfa1蛋白表达的作用.结论 ①淫羊藿甙和雌二醇均可以激活成骨细胞中ERK/MAPK和P38/MAPK信号通路;②淫羊藿甙和雌二醇均能促进成骨细胞中核转录因子Cbfa1的表达,并且ERK/MAPK和P38/MAPK信号通路参与了此过程.     

山茱萸新苷Ⅰ对成骨细胞的增殖及成骨分化的影响

目的基于Wnt信号通路及内质网应激研究山茱萸新苷Ⅰ对大鼠原代成骨细胞的增殖及成骨分化的影响。方法提取原代成骨细胞,CKK8实验检测在药物浓度下山茱萸新苷Ⅰ对成骨细胞增殖的影响;碱性磷酸酶(alkaline phosphatase,ALP)染色检测不同浓度山茱萸新苷Ⅰ干预下成骨细胞ALP的活性情况; Real-time PCR检测Wnt2、β-catenin、BMP2、OPG、NOX4、PERK基因mRNA的表达; Western blot检测Wnt2、β-catenin、PDI、CHOP和BIP蛋白表达量。结果 CKK8实验及ALP染色表明山茱萸新苷Ⅰ对成骨细胞增殖及分化有一定影响,不同浓度山茱萸新苷Ⅰ干预下成骨细胞出现不同程度的增殖;与空白对照组相比,山茱萸新苷Ⅰ组的Wnt2、BMP2、β-catenin、OPG、NOX4的mRNA表达水平显著升高(P0. 01),而PERK明显降低(P0. 01)。与空白对照组相比,山茱萸新苷Ⅰ组的成骨细胞Wnt2、β-catenin、PDI蛋白表达量显著升高(P0. 01),CHOP表达亦有轻微上升,但不明显(P0. 05),而BIP的蛋白表达水平明显降低(P0. 01)。结论山茱萸新苷Ⅰ浓度为1 mmol/mL时在促进成骨细胞的增殖分化的作用上表现最佳,其能显著升高成骨细胞Wnt2、BMP2、β-catenin、OPG和NOX4的mRNA表达水平,而降低PERK的mRNA表达水平,升高Wnt2、β-catenin、PDI的蛋白表达量,降低BIP的表达量,在山茱萸新苷Ⅰ的干预下,Wnt信号通路及内质网应激途径对成骨活动的发生发展起着重要作用。     

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 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.