冬凌草甲素对瘢痕疙瘩成纤维细胞增殖和凋亡的影响

目的 探讨冬凌草甲素对瘢痕疙瘩成纤维细胞增殖和凋亡的影响及其诱导凋亡的机制.方法 采用不同浓度的冬凌草甲素作用于体外培养的成纤维细胞,在不同的时间用MTT法检测冬凌草甲素对瘢痕疙瘩成纤维细胞的增殖抑制作用,用Hoechst染色、流式细胞仪检测细胞凋亡及线粒体膜电位的变化,用比色法检测Caspase-3活性变化.结果 浓度为20、40、80 μmol/L冬凌草甲素加入瘢痕疙瘩成纤维细胞中48 h,其抑制率[(20.47±2.29)%、(25.44 d-2.62)%、(44.37±0.59)%]和凋亡率[(10.23±1.83)%、(16.03±2.21)%、(30.83 4-3.43)%]呈明显的浓度依赖性,与空白对照组比较,其差异有统计学意义(P<0.01);而线粒体膜电位的荧光强度(564.43±27.17、421.54±18.94、288.43±15.29)呈明显下降趋势,与空白对照组(757.24±28.86)比较,其差异有统计学意义(P<0.01);Caspase-3活性(33.46±3.97、45.43±10.87、68.44±15.32)呈明显增强趋势,与空白对照组(19.76±2.43)比较,其差异有统计学意义(P<0.01).结论 冬凌草甲素可抑制瘢痕疙瘩成纤维细胞的增殖,并呈明显的时间和浓度依赖性.其机制与降低线粒体膜电位继而诱导瘢痕疙瘩成纤维细胞凋亡有关.     

丹参酮ⅡA诱导瘢痕疙瘩成纤维细胞凋亡及细胞周期阻滞的实验研究

目的观察丹参酮ⅡA对人瘢痕疙瘩成纤维细胞增殖、凋亡及细胞周期的影响。方法体外培养人瘢痕疙瘩成纤维细胞,予含有不同浓度丹参酮ⅡA的培养液(分别为0μg/mL、50μg/mL、100μg/mL和200μg/mL)进行干预。不同时间点以CCK-8检测细胞增殖活力,流式细胞仪检测细胞凋亡、细胞周期的变化。结果不同浓度丹参酮ⅡA干预和不同时间干预,对瘢痕疙瘩成纤维细胞的增殖活性、早期凋亡率、细胞周期G0/G1期比例的影响,均具有统计学意义(P<0.001),其中200μg/mL组干预效果最明显。结论丹参酮ⅡA具有抑制瘢痕疙瘩成纤维细胞增殖,诱导凋亡并阻滞细胞周期的作用,且干预效果存在浓度依耐性及时间依耐性。     

消瘢醑对瘢痕疙瘩成纤维细胞I、III型胶原蛋白的影响

目的研究复方中药制剂消瘢醑对体外培养的瘢痕疙瘩成纤维细胞(Keloid fibroblast,KFB)I、III型胶原蛋白的影响. 方法 6例瘢痕疙瘩成纤维细胞为实验组,6例正常皮肤成纤维细胞(Normal fibroblast,NFB)为对照组,采用成纤维细胞体外培养、ABC免疫细胞化学染色技术及积分光密度(IOD)分析,观察在10μg/ml消瘢醑浓度作用下,瘢痕疙瘩和正常皮肤成纤维细胞I、III型胶原蛋白的表达. 结果瘢痕疙瘩成纤维细胞I、III型胶原阳性染色表达强度均显著高于正常皮肤成纤维细胞(11113.1±1304.9 vs 3519.6±236.0与11157.7±1300.3 vs 2626.5±426.3,t值分别为14.42和13.47,P值分别为0.00003和0.00004).10μg/ml浓度的消瘢醑作用48小时后:1.瘢痕疙瘩成纤维细胞I、III型胶原阳性染色表达强度均显著高于正常皮肤成纤维细胞(7675.4±825.5 vs 2305.2±320.4与10595.2±1311.5 vs 2434.8±356.9,t值分别为13.37和12.66,P值分别为0.00004和0.00005);2.瘢痕疙瘩和正常皮肤成纤维细胞呈阳性表达的I、III型胶原染色强度明显下降,与未经药物处理的相应空白对照相比具有显著性差异(7675.4±825.5 vs 11113.1±1304.9与10595.2±1311.5 vs 11157.7±1300.3,t值分别为10.31和4.68,P值分别为0.0001和0.0054).瘢痕疙瘩组I型胶原蛋白合成抑制率30.7%,III型胶原蛋白合成抑制率为5.1%. 结论在I、III型胶原蛋白表达方面,体外培养的瘢痕疙瘩成纤维细胞明显高于正常皮肤成纤维细胞;"消瘢醑"能显著抑制体外培养瘢痕疙瘩成纤维细胞和正常皮肤成纤维细胞I、III型胶原蛋白的表达,并以抑制I型胶原表达为主.     

Fas介导瘢痕疙瘩周围皮肤成纤维细胞凋亡及其基因检测研究

目的　探讨瘢痕疙瘩周围皮肤中是否有生物学活性异常成纤维细胞 ,以期进一步了解瘢痕疙瘩的发展机制。方法　所取新鲜组织标本进行细胞培养 ,通过碘化丙啶 (PI)染色、激光流式细胞仪比较不同浓度Fas单克隆抗体 (FasMcAb ,0～ 10 0 0 μg/L)作用后各组成纤维细胞凋亡率。采用聚合酶链反应 (PCR)技术对Fas基因外显子 8进行DNA扩增并测序。结果　FasMcAb作用2 4h后 ,瘢痕疙瘩成纤维细胞在各浓度段均不能凋亡 ,瘢痕疙瘩周围皮肤成纤维细胞随FasMcAb作用浓度的增加凋亡率虽有所增加 ,但总体比较与瘢痕疙瘩差异无显著性 (P >0 .0 5 ) ,而与正常皮肤差异有显著性 (P <0 .0 1)。瘢痕疙瘩周围皮肤 6例标本中有 4例 (4 /6)Fas基因外显子 8及其下游序列存在点突变及移码突变 ,均与同患者瘢痕疙瘩细胞基因序列分析结果一致 ,而两组正常皮肤成纤维细胞则未发现有任何形式的基因突变。结论　瘢痕疙瘩周围 0 .5cm皮肤内存在生物学活性异常细胞 ,这可能为瘢痕疙瘩浸润性生长的结果及其治疗后易复发的原因之一。     

雷帕霉素对瘢痕疙瘩成纤维细胞增殖、迁移及凋亡的影响

目的通过体外细胞培养实验,观察雷帕霉素对瘢痕疙瘩及正常皮肤成纤维细胞增殖、迁移和凋亡的影响,探讨雷帕霉素用于治疗瘢痕疙瘩的可能性及有效性。方法在无菌条件下切取人瘢痕疙瘩和正常皮肤组织,分离培养其成纤维细胞;实验分为不同浓度雷帕霉素(2.5、5.0、7.5、10.0μmol/L)处理组和DMSO溶剂对照组。分别采用MTS法、划痕法和Annexin V-PI染色检测不同浓度雷帕霉素对两种成纤维细胞增殖、迁移和凋亡的影响。结果雷帕霉素能够抑制两种成纤维细胞的增殖,且对正常皮肤成纤维细胞增殖的抑制作用更强,其浓度越高抑制效率越高;能够显著抑制两种成纤维细胞的迁移,并明显诱导正常皮肤成纤维细胞的凋亡,且高浓度(10.0μmol/L)雷帕霉素处理组的凋亡率最高,但对瘢痕疙瘩成纤维细胞的凋亡作用不明显。结论雷帕霉素可以抑制两种成纤维细胞的增殖和迁移,诱导成纤维细胞的凋亡;雷帕霉素对成纤维细胞的影响,可能成为预防瘢痕疙瘩等纤维化疾病的有效药物。     

瘢痕疙瘩microRNA表达谱的筛选及miR-199a-5p生物功能的初步研究

目的 探讨并筛选出瘢痕疙瘩相关微小RNAs(miRNAs),检测其对瘢痕疙瘩成纤维细胞(keloid fibroblasts,KF)增殖的影响.方法 收集手术切除瘢痕疙瘩及正常皮肤组织标本各8例,采用基因芯片检测瘢痕疙瘩与正常皮肤组织差异表达的miRNA,并采用qRT-PCR验证,在瘢痕疙瘩成纤维细胞株中转染miRNA模拟物,模拟细胞中成熟miRNA的高表达,用EdU检测方法检测其对瘢痕疙瘩成纤维细胞增殖的影响.结果 ①通过芯片检测发现包括miR-199a-5p在内的17个差异表达的miRNAs.②qRT-PCR验证结果显示miR-199a-5p表达下调,与芯片检测结果相一致.③miR-199a-5p模拟物转染组与阴性对照组EdU的阳性率分别为(20.72±2.50)％和(27.68±4.92)％,miR-199a-5p模拟物转染组瘢痕疙瘩成纤维细胞的增殖率下降(t=2.183,P=0.047).同时,细胞的生长周期分布也发生改变,MiR-199a-5p模拟物转染组S期与G2/M期细胞百分比分别为(33.93±1.30)％和(10.87±0.80)％,阴性对照组分别为(31.39±0.79)％和(9.27±0.46)％,差异有统计学意义(P＜0.05).结论 ①瘢痕疙瘩中miRNA的差异表达有组织特异性;②miR-199a-5p在瘢痕疙瘩中的显著低表达,可影响瘢痕疙瘩成纤维细胞周期分布,抑制瘢痕疙瘩成纤维细胞增殖,提示miR-199a-5p可能参与了瘢痕疙瘩成纤维细胞增殖的调控.     

二甲双胍对瘢痕疙瘩成纤维细胞增殖及胶原合成的影响

目的 探讨二甲双胍对瘢痕疙瘩成纤维细胞增殖、胶原合成及蛋白激酶B/叉头框蛋白O1(Akt/FoxOl)信号通路磷酸化水平的影响.方法 将瘢痕疙瘩成纤维细胞分为培养液处理的空白对照组和用含不同浓度二甲双胍培养液处理的实验组,给药后48 h采用CCK-8比色法检测细胞增殖,western blot技术检测Akt 、FoxO1的磷酸化水平,羟脯氨酸试剂盒检测胶原的合成.结果 二甲双胍可显著抑制成纤维细胞的增殖,用30、60、90、120 mmol/L不同浓度的二甲双胍处理成纤维细胞后,成纤维细胞的抑制率依次升高为(13.30±2.04)％、(22.64±4.70)％、(54.00±5.34)％和(63.12±3.48)％,呈明显的剂量依赖性.与空白对照组比较,二甲双胍处理后的成纤维细胞中Akt、FoxO1磷酸化水平降低,胶原蛋白产生减少,并且呈剂量依赖性(P ＜0.05,P＜0.01).结论 二甲双胍可显著抑制瘢痕疙瘩成纤维细胞的增殖及胶原合成,其机制可能与调控Akt/FoxOl信号通路的磷酸化水平有关.     

甲基化酶抑制剂5-氮杂-2-脱氧胞苷对瘢痕疙瘩成纤维细胞TGF-β/smad信号通路的影响

目的 探讨甲基化酶抑制剂5-氮杂-2-脱氧胞苷对瘢痕疙瘩成纤维细胞TGF-β/smad信号通路的影响.方法 收集瘢痕疙瘩及正常皮肤组织各15例,免疫组化检测磷酸化smad2(p-smad2)和磷酸化smad3(p-smad3)在瘢痕疙瘩和正常皮肤中的阳性表达率;将瘢痕疙瘩分为实验组和对照组,实验组以5-氮杂-2-脱氧胞苷(5×10-5mmol/L)干预,对照组用等量的DMEM培养液,采用组织块法培养人瘢痕疙瘩成纤维细胞,流式细胞仪分析5-氮杂-2-脱氧胞苷(5×10-5mol/L)对瘢痕疙瘩成纤维细胞周期及凋亡的影响;Western blot检测各组p-smad2、p-smad3、TGF-β1和smad7的表达变化;细胞免疫荧光染色法观察各组瘢痕疙瘩成纤维细胞内p-smad2和p-smad3蛋白的影响.结果 瘢痕疙瘩组织中p-smad2和p-smad3阳性表达率明显高于正常皮肤组织中p-smad2和p-smad3阳性表达.流式细胞仪显示5-氮杂-2-脱氧胞苷干预瘢痕疙瘩成纤维细胞后,细胞停滞于G0/G1期比例增加并且细胞凋亡率增加,瘢痕疙瘩成纤维细胞中p-smad2和p-smad3蛋白的表达减少,同时,TGF-β1蛋白表达减少,smad7蛋白表达回升.此外,5-氮杂-2-脱氧胞苷抑制smad2和smad3磷酸化及核转移.结论 甲基化酶抑制剂5-氮杂-2-脱氧胞苷可抑制瘢痕疙瘩成纤维细胞的增殖及促进其凋亡,其作用机制可能与抑制TGF-β/smad信号通路有关.     

RNA干扰Survivin基因表达对瘢痕疙瘩中成纤维细胞增殖与凋亡的影响

目的 探讨RNA干扰Survivin基因表达对癜痕疙瘩成纤维细胞增殖与凋亡的影响,为瘢痕疙瘩的基因治疗提供实验依据.方法 构建靶向Survivin的siRNA表达质粒,利用Lipofectamine TM 2000转染体外培养瘢痕疙瘩成纤维细胞;采用RT-PCR、Western blot技术检测成纤维细胞中Survivin基因的被干扰情况及Caspase-3基因的表达情况;利用MTT法、流式细胞仪检测成纤维细胞的增殖与凋亡情况.结果 靶向Survivin的序列特异件的siRNA对成纤维细胞中Survivin基因表达的抑制率:在mRNA水平为59.86%和82.57%,在蛋白质水平分别为48.76%和72.53%.Caspase-3基因的表达和活性显著增加(P＜0.01).转染靶向Survivin的RNAi表达质粒对瘢痕疙瘩成纤维细胞增殖的抑制较显著(P＜0.05).Annexin V-FITC/P1双染法显示,干扰Survivin基因表达后成纤维细胞的调亡率高于对照组(56.36%,P＜0.05).结论 所构建的靶向Survivin的RNAi质粒可有效地抑制瘢痕疙瘩成纤维细胞中Survivin基因的表达,通过Survivin基因表达的下调激活Caspas-3基因活性,可显著抑制成纤维细胞的增殖并诱导其凋亡,为瘢痕疙瘩的基因治疗开辟一新途径.     

δ-氨基酮戊酸光动力疗法对瘢痕疙瘩成纤维细胞增殖及胶原分泌的影响

目的 探讨δ-氨基酮戊酸(ALA)光动力疗法(PDT)对瘢痕疙瘩成纤维细胞增殖、凋亡及胶原分泌的影响.方法 取体外培养的第3代瘢痕疙瘩成纤维细胞,给予0、1、3、6及9 mmol/L的ALA避光孵育3h,635 nm波长红光照射,能量密度为30 J/cm2,照射后继续孵育24 h,CCK-8法检测成纤维细胞增殖的抑制率;比色法检测羟脯氨酸含量;Western blot法检测丝氨酸/苏氨酸蛋白激酶Akt磷酸化激活形式p-Akt及程序性死亡因子4(PDCD4)的表达水平.结果 ALA在0、1、3、6及9 mmol/L的浓度下,瘢痕疙瘩成纤维细胞增殖的抑制率分别为0、(8.30±1.01)％、(29.48±3.27)％、(52.01±5.34)％、(79.99±5.85)％;羟脯氨酸含量分别是(9.540 0±0.352 42)、(6.242 5±0.224 85)、(5.107 5士0.534 88)、(3.4900±0.623 48)、(2.945 0±0.514 10) μg/mg;p-Akt的相对表达量分别为1、0.75±0.12、0.52±0.14、0.41±0.18、0.32±0.09;PDCD4的相对表达量分别为1、1.18±0.19、1.51±0.22、0.15±0.30、2.44±0.22.1、3、6及9 mmol/L组与0 mmol/L相比,差异均具有统计学意义(P＜0.05).结论ALA在1～9 mmol/L范围内,均可可显著抑制成纤维细胞的增殖,减少羟脯氨酸的含量,表明δ-氨基酮戊酸光动力疗法可能是瘢痕疙瘩的一种潜在的治疗方法.     

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.     

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.     

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.     

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.