吸脂组织中脂肪干细胞分离和定向分化的研究

目的探讨吸脂组织中的干细胞分离和体外诱导分化为表皮样细胞、成骨细胞及脂肪细胞的可能性。方法通过电动负压吸引获取1例行吸脂手术的30岁女性腹部脂肪组织,酶消化法获取脂肪来源干细胞,体外培养扩增,通过流式细胞仪检测表面抗原的表达。取生长良好的第3代人脂肪来源干细胞,分别应用成表皮诱导培养液（70％培养液A＋30％成纤维细胞培养基上清液＋10ng／L表皮生长因子）,成骨诱导培养基（DMEM／10％FBS,0．1μmol／L地塞米松,50μmol／L维生素C,10mmol／Lβ-甘油磷酸钠,100U／ml青霉素,100U／ml链霉素）和成脂肪细胞诱导培养基（DMEM＋10％FBS＋500μmol／L1-甲基-3-异丁基黄嘌呤＋1μmol／L吲哚美辛）诱导20d后,分别对成表皮诱导组进行免疫组化检测CK19表达,成骨诱导组进行碱性磷酸酶检测,成脂诱导组进行油红O检测。结果流式细胞仪鉴定结果示,人脂肪来源干细胞CD44和CD49d为阳性,CD34为阴性。诱导20d后,成表皮诱导组示免疫组织化学鉴定结构显示有CK19的表达;成骨诱导组示细胞碱性磷酸酶染色阳性;成脂肪细胞诱导组示油红O染色,胞质内脂滴均被染成红色,证实为脂性液体。结论从吸出的脂肪组织中分离出脂肪来源干细胞,在体外进行了脂肪干细胞的扩增和传代,所分离的脂肪来源干细胞具备多向分化能力。     

人瘢痕疙瘩成纤维细胞的干细胞特性研究

目的探讨人瘢痕疙瘩成纤维细胞是否具有间充质干细胞的生物学特性,从细胞分子学角度为进一步研究瘢痕疙瘩的发病机制提供基础研究资料。方法以人瘢痕疙瘩标本为研究对象,通过组织块贴壁法获得成纤维细胞,用流式细胞术检测细胞表面标志CD29、CD34、CD44及CD90的表达;采用免疫细胞化学法检测细胞波形蛋白、Oct4的表达;将体外诱导细胞向成骨细胞、成软骨细胞、成脂肪细胞方向分化。结果采用组织块贴壁法,从瘢痕疙瘩标本中获得成纤维细胞;经流式细胞术检测瘢痕疙瘩成纤维细胞呈高表达CD29、CD44、CD90等间充质干细胞表面标志;经免疫细胞化学法检测瘢痕疙瘩成纤维细胞的波形蛋白、Oct4呈阳性表达;体外诱导分化结果:瘢痕疙瘩成纤维细胞可向成骨细胞、成软骨细胞和成脂肪细胞分化,具有多向分化潜能。结论人瘢痕疙瘩成纤维细胞具有间充质干细胞的生物学特性,可能是瘢痕疙瘩发生、发展的重要因素。     

高成脂脂肪干细胞系的分子克隆筛选

目的 探讨并筛选具备高成脂能力的脂肪干细胞系表面标志、可应用于脂肪组织工程的种子细胞,以提高组织工程化脂肪的构建效率.方法 胶原酶消化人脂肪组织,获得脂肪干细胞,培养扩增后成脂诱导,收集诱导成熟的脂肪细胞,天花板贴壁培养得到去分化脂肪细胞.比较去分化脂肪细胞与人脂肪干细胞的增殖能力,成脂分化能力及表面抗原表达的变化.结果 去分化脂肪细胞与脂肪干细胞的形态和增殖能力相似;去分化脂肪细胞的成脂分化能力高于脂肪干细胞;两种细胞表面抗原的表达大致相同,但去分化脂肪细胞的CD54的阳性表达高于脂肪干细胞.结论 CD54的表达可能与去分化脂肪细胞的高成脂分化能力密切相关,可能是高成脂系干细胞的特异性表面抗原标志.     

骨髓基质干细胞分化为胰岛样细胞的形态学观察

目的　探讨体外自体骨髓基质干细胞 (MSC)定向诱导分化为胰岛样细胞的可能性。方法　对Wistar大鼠MSC进行体外培养 ,通过不同的条件诱导MSC向胰岛样细胞分化 :LN组 ,10mmol/L尼克酰胺 1mmol/Lβ 巯基乙醇的低糖Dulbecco最低必须培养基 [L DMEM ,含 2 0 %胎牛血清 (FSC) ]预先诱导 2 4h ,10mmol/L尼克酰胺 1mmol/Lβ 巯基乙醇的无血清高糖Dulbecco最低必须培养基 (H DMEM )诱导 10h。HN组 ,含 2 0mmol/L尼克酰胺的L DMEM (2 0 %FSC)预先诱导 2 4h ,2 0mmol/L尼克酰胺的无血清H DMEM诱导 10h。通过倒置显微镜观察诱导细胞的形态学变化。结果　LN、HN组细胞均可见部分骨髓基质干细胞分化、增殖 ,形成胰岛样细胞团 ,部分细胞向神经元样细胞分化 ;对照组细胞未见明显分化。结论　体外诱导骨髓基质干细胞定向分化为胰岛样细胞存在可行性。     

人瘢痕疙瘩来源干细胞的生物学特性鉴定

目的 分析人瘢痕疙瘩来源干细胞的生物学特性,为进一步研究该细胞在瘢痕疙瘩形成中的作用提供参考.方法 以人瘢痕疙瘩为研究对象,采用酶消化法及传代培养法分离筛选瘢痕疙瘩干细胞.选取原代和(或)第3代贴壁细胞进行生物学特性鉴定:加入CD29-藻红蛋白(PE)、CD34-PE、CD44-异硫氰酸荧光素(FITC)、CD90-FITC、CD45-多甲藻黄素叶绿素蛋白抗体,流式细胞仪检测细胞表面分子标记物CD29、CD34、CD44、CD45及CD90的表达及细胞周期;加入小鼠抗人细胞角蛋白19(CK19)即用型单克隆抗体、鼠抗波形蛋白即用型单克隆抗体,免疫细胞化学法检测CK19、波形蛋白的表达;RT-PCR检测细胞Oct4的表达.取第1代细胞,应用成骨细胞、成脂肪细胞、软骨细胞诱导分化培养液进行诱导分化实验,观察细胞的多向分化能力.结果 传代培养后,细胞形态较为均一,以梭形为主,排列不规则.流式细胞仪检测表明,该细胞高表达CD29、CD44、CD90等间充质干细胞表面标记物,低表达CD34、CD45等造血干细胞表面标记物.细胞周期分析显示67.66%的细胞处于G0/G1期,26.24%的细胞处于G2/M期,6.11%的细胞处于S期.免疫细胞化学法检测显示细胞波形蛋白表达呈阳性、CK19表达呈阴性.RT-PCR法检测显示细胞Oct4表达呈阳性.诱导分化实验表明,细胞可向成骨细胞、软骨细胞和成脂肪细胞分化,具有多向分化潜能.结论 人瘢痕疙瘩内存在间充质样干细胞,这种干细胞可能在瘢痕疙瘩形成中发挥重要作用.

Abstract：

Objective To investigate the biological characteristics of human keloid-derived stem cells (KDSC) in order to further research its role in keloid pathogenesis. Methods Human keloid specimens were harvested to isolate and select KDSC by enzyme digestion and subculturing. Primary and (or) the third generation of KDSC were collected for identification of biological characteristics as follows. (1) After addition of mouse anti-human monoclonal fluorescent antibodies (CD29-PE,CD34-PE,CD44-FITC,CD90-FITC,CD45-PerCP),the expression of cell surface antigen phenotype (CD29,CD34,CD44,CD45,CD90) as well as cell cycle was analyzed by flow cytometry. (2) After addition of mouse anti-human cell keratin (CK19) monoclonal antibody and mouse anti-human vimentin monoclonal antibody,the expression level of CK19 and vimentin was respectively determined with immunocytochemical method. RT-PCR was used to detect the expression of Oct4. The multipotent differentiation capacity of the first generation KDSC was observed with osteogenic,chondrogenic and adipogenic nutrient media. Results After being subcultured,the sizes of cells were similar,and the majority of them were spindle-shaped with disorderly arrangement. The cells highly expressed typical surface markers of mesenchymal stem cells (such as CD29,CD44,and CD90,etc.) with low expression of hematopoietic stem cell surface markers (such as CD34,CD45,etc.). 67.66% of cells were in G0/G1 phase,26.24% of cells were in G2/M phase,and 6.11% of cells were in S phase. Vimentin was positively expressed in KDSC while CK19 was negatively expressed. The expression of Oct4 was also positive. After being cultured in inducing differentiation media,the cells could differentiate into osteoblasts,chondrocytes,and adipocytes. Conclusions Stem cells existing in human keloid,which are similar to mesenchymal stem cells,may play an important role in keloid pathogenesis.     

人瘢痕疙瘩间充质样干细胞向成骨细胞分化过程中Notch信号表达的研究

目的研究人瘢痕疙瘩间充质样干细胞向成骨细胞分化过程中,Notch 1~4受体的表达情况,探讨Notch信号通路是否参与调控人瘢痕疙瘩间充质样干细胞的成骨分化。方法经患者知情同意后,分离培养人瘢痕疙瘩间充质样干细胞,采用流式细胞术检测CD29、CD34、CD44、CD45及CD90的表达;免疫细胞化学法检测Oct 4的表达;体外诱导其向成骨细胞分化,诱导3周后行茜素红染色;于诱导前及诱导后2、3周,采用实时定量-多聚酶链反应(RT-PCR)及免疫蛋白印迹法(western blot),分别检测细胞Notch 1~4受体mRNA及蛋白的表达。结果流式细胞术结果表明,分离培养的细胞高表达间充质干细胞表型CD29(98.76%)、cD44(98.11%)、CD90(97.86%),不表达造血干细胞表型CD34(0.05%)、CD45(0.03%);免疫细胞化学法检测多能干细胞标志物Oct4呈阳性表达;向成骨细胞体外诱导3周后,茜素红染色可见明显的钙盐结节。RT-PCR和western blot结果显示,随着诱导时间的延长,Notch 1~4受体mRNA和蛋白的相对表达量逐渐减少,差异有统计学意义(P0.05)。结论在人瘢痕疙瘩间充质样干细胞向成骨细胞诱导分化过程中,Notch受体信号的表达逐渐减弱,低水平的Notch信号激活可能有利于瘢痕疙瘩间充质样干细胞的成骨分化。     

脂肪间充质干细胞的基本生物学特性及向成骨细胞诱导分化的实验研究

目的　研究脂肪间充质干细胞的基本生物学特性以及在特定培养条件下向成骨细胞分化 ,探讨其作为骨组织工程的种子细胞的可行性。方法　取 3周龄Lewis大鼠的腹股沟脂肪垫 ,消化法获得脂肪间充质干细胞 ,分别用脂肪诱导培养基和成骨诱导培养基诱导其向脂肪细胞与成骨细胞分化 ,组织化学染色、免疫细胞化学染色和Westernblot检测细胞分化的情况。结果　从成体大鼠脂肪组织中培养出脂肪间充质干细胞 ,原代脂肪间充质干细胞能自发分化为脂肪细胞 ,传代细胞在胰岛素和呋塞米的作用下生成脂滴 ,过氧化物酶体增殖物激活受体 (PPAR)γ表达增强 ,向脂肪细胞分化 ;在呋塞米、抗坏血酸、β 甘油磷酸钠的诱导下 ,脂肪间充质干细胞的碱性磷酸酶(ALP)活性检测显示诱导组与对照组差异有显著性 (P <0 .0 1) ,vonKossa染色出现钙结节 ,骨桥蛋白 (OPN)、骨形态发生蛋白 (BMP) 2免疫细胞化学染色阳性 ,Westernblot检测到诱导后细胞OPN、BMP2的表达。结论　从脂肪组织中可获得具有多分化潜能的间充质干细胞 ,经诱导后可分化为脂肪细胞和成骨细胞 ,有可能成为骨组织工程较理想的种子细胞之一     

人腹膜中间充质干细胞生物学特性的初步研究

目的探讨人腹膜中是否含有间充质干细胞(Mesenchymal stem cells,MSC),并研究其生物学特性。方法腹膜取自接受胃大部切除及腹腔淋巴结清扫术的胃癌患者。将腹膜剪碎,Ⅰ型胶原酶消化后以低密度接种,2周后计算细胞群中成纤维细胞集落形成单位(Colony-forming unit-fibroblast,CUF-F)数量;流式细胞分析贴壁细胞表型;定向诱导2周后,碱性磷酸酶和油红O染色,观察细胞体外成骨和成脂肪能力。结果贴壁的细胞呈成纤维细胞样,消化的腹膜细胞群中,CFU-F比例平均为0.574‰(0.26‰～0.84‰)。流式分析显示,细胞均一表达CD29、CD44和CD73,不表达CD31、CD34和CD45。成骨细胞定向诱导后,细胞呈现碱性磷酸酶活性;成脂诱导后细胞内出现脂肪滴,油红O染色阳性。结论人腹膜中富含MSC,可作为一个含有生物支架的干细胞来源。     

脂肪干细胞诱导分化成淋巴管内皮样细胞的初步研究

目的 探讨利用血管内皮细胞生长因子C(VEGF-C) (156s)等生长因子诱导脂肪干细胞成为淋巴管内皮样细胞的方法. 方法 取健康成人脂肪组织,胰酶消化法获得脂肪组织来源的间质干细胞(adipose-derived stem cell),通过流式细胞仪检测其表面标记,并进行成脂肪、成骨诱导等体外分化能力鉴定.取生长状态良好的P3代细胞进行诱导实验:设置含VEGF-C156 s、bFGF等生长因子的诱导液组为实验组,并设空白对照组(常规L-DMEM培养基).观察诱导前后两组细胞的形态变化,并于10 d后进行LYVE-1免疫荧光的鉴定. 结果 成功分离纯化脂肪干细胞,流式细胞结果显示,CD13、CD29、CD44、CD105高表达,CD31、CD34、CD45、HLA-DR极低表达,具有间充质干细胞特性;体外成脂和成骨能力鉴定也取得成功;在体外成功利用含VEGF-C156 s、bFGF等生长因子的诱导液将脂肪干细胞诱导为淋巴管内皮样细胞,实验组LYVE-1免疫荧光显色呈强阳性,而对照组则未见到阳性染色;荧光强度定量结果差异有统计学意义(P＜0.01). 结论 利用含有VEGF-C156 s的诱导液可以将脂肪干细胞诱导分化为淋巴管内皮样细胞.     

人脂肪组织来源干细胞体外增殖分化中端粒酶的表达

目的 探讨体外培养条件下人脂肪干细胞增殖和分化过程中端粒酶的表达水平,为其作为种子细胞的应用研究提供理论基础.方法 体外分离、培养人脂肪干细胞并传代,行流式细胞表面抗原分析,并用油红O染色及茜素红染色行成骨和成脂诱导分化的鉴定;采用TRAP法分别检测新鲜的不同时间培养的人脂肪干细胞和诱导分化为脂肪细胞的人脂肪干细胞的端粒酶活性.结果 脂肪干细胞具有向脂肪细胞、成骨细胞多向分化的能力,且表达干细胞相关表面标志物.新鲜分离和传代的脂肪干细胞,在体外培养12代内端粒酶活性呈阴性或低水平表达;一旦经过成脂诱导分化,细胞端粒酶活性表达上调,培养3～6 d后端粒酶活性开始出现逐渐降低.结论 用胶原酶消化法从脂肪抽吸术中得到的细胞主要是人脂肪干细胞;在体外培养增殖的过程中,人脂肪干细胞的端粒酶活性未见异常表达;成脂诱导分化早期人脂肪干细胞端粒酶活性增高,其后开始出现下降趋势.     

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.     

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.     

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.