血清趋化素及肿瘤坏死因子α水平与2型糖尿病肾脏病的相关性研究

目的观察不同分期糖尿病肾脏病(diabetic kidney disease,DKD)患者血清趋化素(chemerin)及肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)水平的变化,并探讨其与DKD的相关性。方法入选45名健康体检者作为正常对照(normal control,NC)组和133例2型糖尿病患者,后者根据尿微量白蛋白/肌酐(the value of urinary albumin/creatine ratio,ACR)水平分为单纯糖尿病(simple diabetes mellitus,SDM)组47例、微量白蛋白尿(micro albuminuria DKD,mic-DKD)组41例和大量白蛋白尿(macro albuminuria DKD,mac-DKD)组45例。采用ELISA法测定4组研究对象的血清chemerin和TNF-α水平,并分析DKD发生的危险因素。结果 NC组血清chemerin浓度为(34.14±7.54)ng/ml,TNF-α浓度为(103.99±20.43)ng/L。SDM组血清chemerin浓度为(38.23±5.48)ng/ml,TNF-α浓度为(134.42±27.31)ng/L。mic-DKD组血清chemerin浓度为(42.69±8.os)ng/ml,TNF-α浓度为(165.48±32.63)ng/L。mac-DKD组血清chemerin浓度为(47.32±9.11)ng/ml,TNF-α浓度为(227.53±58.31)ng/L。4组血清chemerin和TNF-α水平逐渐升高,组间比较差异具有统计学意义(均P0.05)。血清chemerin水平与TNF-α、超敏C反应蛋白(high sensitivity C-reactive protein,hs-CRP)、糖化血红蛋白(glycosylated hemoglobin,HbA1c)、血肌酐(SCr)及病程呈正相关,与高密度脂蛋白胆固醇(high-density lipoprotein cholesterol,HDL-C)呈负相关。血清TNF-α水平与尿ACR、HbA1c、hs-CRP、SCr、低密度脂蛋白胆固醇(ligh-density lipoprotein cholesterol,LDL-C)及病程呈正相关,与HDL-C呈负相关。Logistic回归分析显示,chemerin、TNF-α、白细胞、年龄、HbA1c、低HDL-C及高血压是DKD发生的独立危险因素。结论 Chemerin和TNF-α参与了DKD发病,检测其水平可以在一定程度上反映DKD病情的严重程度。     

管腔外局部应用紫杉醇对豚鼠胆管对端吻合术后吻合口愈合的作用

目的探讨局部应用紫杉醇对豚鼠动物模型胆管对端吻合术后瘢痕愈合、狭窄发生抑制作用的可能性。方法制作豚鼠胆管对端吻合动物模型。将42只豚鼠按术后时间（3d、2周、1个月）随机分为3组,每组按紫杉醇组与对照组各分为2组,每组7只。紫杉醇组于显微吻合操作完成后吻合口管壁外局部涂抹紫杉醇溶液（1000μmol/L,0.05ml）,作用10min左右。术后分别于3d、2周、1个月时取材,与对照组比较,进行组织学、管壁厚度检测。应用透射电镜观察紫杉醇诱导细胞凋亡的超微结构。结果术后胆管壁呈炎症反应,内膜增生显著。术后3天和1个月时,紫杉醇组管壁厚度均小于对照组[3天：（574.41±24.53）μmvs（802.98±24.42）μm,t=-6.604,P=0.000;1个月：（1383.36±36.64）μmvs（1518.56±34.89）μm,t=-2.672,P=0.020）]。透射电镜可见紫杉醇诱导细胞凋亡及细胞器损害超微结构表现。结论管腔外局部单次使用紫杉醇1个月内可起到延缓豚鼠动物模型胆管管壁增厚的作用。     

联合检测血清Leptin、INS、TNF-α、SOD对NAFLD的临床意义

目的：探讨血清瘦素(Leptin),胰岛素(INS),胰岛素抵抗指数(IRI)．肿瘤坏死因子α(TNF-α),超氧化物岐化酶(SOD)浓度变化对NAFLD诊断及预后判断的临床应用价值。方法：采用放射免疫法检测Leptin、INS、TNF-α,化学法检测SOD,根据HOMA-IR-[FBG(mmol/l)×FIN(mIU/l)]/22．5计算胰岛素抵抗指数(IRI)。结果：①NASH组32例瘦素浓度(13．320±5．323ng/ml)显著高于NASFL组32例(8．068±2．320ng/ ml)(P＜0．05)和NC组32例(3．533±1．686ng/ml)(P＜0．05),NASFL组32例瘦素浓度显著高于NC组(P＜0．05)。②NASH组INS浓度(24．810±9．01 7mIU/l)及IRI(6．733±2．501)显著高于NC组(15．460±6．012mIU/l,4．131±2．158)(P＜0．05),NASFL组INS浓度(21．180±11．610mIU/l)及IRI(6．462±2．872)显著高于NC组(P＜0．05),NASH组INS浓度及IRI与NASFL组比较差异无显著性(P＞0．05)。③NASH组TNF-α浓度(0．322±0．165ng/ml)显著高于NC组(0．254±0．093ng/ml)(P＜0．05)．NASH组与NASFL组TNF-α浓度(0．271±0．098ng/ml)比较差异有显著性(P＜0．05),NASFL组与NC组TNF-α浓度比较差异无显著性(P＞0．05)。④NC组SOD浓度(112．200±7．978U/ml)显著高于NASH组(72．540±1．32U/ml)(P＜0．05),NASFL组SOD浓度(109．900±8．903U/ml)显著高于NASH组(P＜0．05),NASFL组与NC组SOD浓度比较差异无显著性(P＞0．05)。结论：联合检测血清Leptin、INS、TNF-α、SOD对NAFLD的诊断及预后判断具有一定的临床参考价值。     

羊膜制品对宫腔粘连分离术后宫腔渗出液中细胞因子的影响及意义

目的探讨羊膜制品对宫腔粘连分离术(trans-cervical resection of adhesions,TCRA)后宫腔渗出液中与粘连有关细胞因子浓度变化的影响及意义。方法选择30例因重度宫腔粘连实施TCRA,随机分为研究组15例:宫腔内放置覆盖羊膜制品的Foley’s球囊导管;对照组15例:宫腔内仅放置Foley’s球囊导管。分别于术后3 h、6 h、9 h、12 h、24 h、48 h、72 h和4 d、5 d、6 d、7 d经球囊导管收集宫腔渗出液,测量肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、血管内皮生长因子(vascular endothelial growth factor,VEGF)和白细胞介素1(interleukin-1,IL-1)的浓度,观察羊膜制品使用后子宫腔创面渗液量与上述细胞因子的变化。结果宫腔渗液量的变化:研究组总渗液量(30.6±18.2)ml,显著少于对照组(62.7±32.9)ml(t=-3.307,P=0.003);研究组术后48 h渗液量达峰值,中位数5.50 ml(0.50~13.00 ml),7 d时渗液量显著低于48 h水平(χ~2=15.691,P=0.000);对照组术后4 d渗液量达峰值,中位数11.50 ml(3.00~23.00 ml),7 d时渗液量显著低于4 d水平(χ~2=9.549,P=0.002);研究组术后7 d渗液量中位数1.00 ml(0.00~2.00 ml),显著少于对照组中位数6.50 ml(5.00~8.00 ml)(Z=-4.666,P=0.000)。3种粘连相关细胞因子:研究组术后48 h TNF-α达峰值浓度(279.35±29.52)ng/L,术后7 d降为(243.56±43.99)ng/L(q=3.990,P0.05);对照组TNF-α术后48 h达峰值浓度(309.18±35.20)ng/L,与术后7 d(285.06±38.20)ng/L无统计学差异(q=2.485,P0.05)。研究组VEGF术后72 h达峰值浓度(629.24±101.38)ng/L,术后7 d降为(428.16±104.35)ng/L(q=6.974,P0.05);对照组VEGF术后24 h达峰值浓度(713.47±110.20)ng/L,术后7 d降为(564.59±119.92)ng/L(q=5.169,P0.05)。研究组IL-1术后6 d达峰值浓度(84.41±16.31)ng/L,与术后7 d(80.62±14.77)ng/L相比无统计学差异(q=0.923,P0.05);对照组IL-1术后5 d达峰值浓度(101.35±19.53)ng/L,与术后7 d(89.89±13.83)ng/L相比无统计学差异(q=2.736,P0.05)。结论使用羊膜制品能够明显减少TCRA术后宫腔渗液量和渗液时间,在一定程度上降低渗出液中TNF-α、VEGF和IL-1粘连相关细胞因子的浓度,小样本数据表明TCRA术后使用羊膜制品有助于降低再粘连形成。     

TNF-α抑制兔耳瘢痕增生的实验研究

目的：通过建立兔耳增生性瘢痕模型,研究肿瘤坏死因子（tumor necrosis factor-alpha,TNF-α）在减轻增生性瘢痕形成中的作用。方法：建立兔耳增生性瘢痕模型,实验动物随机分为A、B、C、D、E五组,并设C组为对照组,A、B、D、E组瘢痕内分别注射不同浓度TNF-α溶液0．1ml（100ng／ml,500ng／ml,1000ng／ml,5000ng／ml）,C组瘢痕内注射等量生理盐水。观察增生性瘢痕组织块的组织结构、成纤维细胞的密度以及caspase-3蛋白的表达情况。分析不同浓度TNF-α对增生性瘢痕形成的影响。结果：瘢痕增生块减轻程度随TNF-α浓度增加而增加,即TNF-α浓度越高,增生性瘢痕体积越小,成纤维细胞密度越低,caspase-3表达强度越强。结论：肿瘤坏死因子-α可明显抑制兔耳增生性瘢痕的形成及瘢痕组织增生．     

肿瘤坏死因子-α通过骨形态发生蛋白-2信号通路抑制成骨细胞分化的实验研究

目的 通过观察肿瘤坏死因子-α(TNF-α)体外诱导鼠肌源细胞C2C12向成骨细胞分化过程中的影响,探讨TNF-α通过骨形态发生蛋白-2(BMP-2)信号通路对成骨细胞分化的调控及其规律.方法 应用BMP-2体外诱导鼠肌源细胞C2C12 向成骨细胞分化模型,实验分4组:对照组不做任何处理,BMP-2组放入100 ng/mL BMP-2,TNF-α组放入5 ng/mLTNF-α,BMP-2+TNF-α组放入100ng/mLBMP-2和5 ng/mL TNF-α.当BMP-2浓度保持100ng/mL时,添加TNF-α浓度为0、2、5、10 ng/mL;当TNF-α保持在5 ng/mL时,添加BMP-2浓度为100、200、300 ng/mL,分别进行培养7 d后,茜素红染色观察细胞矿化,4-硝基苯基磷酸二钠盐偶氮法定量分析成骨细胞碱性磷酸酶(ALP)活性.结果 TNF-α组、BMP-2组和BMP-2+TNF-α组的成骨活性分别为0.260±0.245、7.311±0.772、1.344±0.133,组间两两比较差异均行统计学意义(P＜0.05).当BMP-2浓度保持100 ng/mL,TNF-α浓度为0、2、5、10 ng/mL时,ALP 活性分别为10.207±0.459、6.183±0.374、1.873±0.388、0.096±0.023,组间两两比较差异均有统计学意义(P＜0.05).当TNF-α保持在5 ng/mL,B MP-2浓度为100、200、300 ng/mL时,ALP活性分别为1.859±0.220、3.779±0.216、4.716±0.304,组间两两比较差异均有统计学意义(P＜0.05).结论 TNF-α能够抑制BMP-2诱导的成骨分化,并具有剂量-效应依赖相关性;且足量的BMP-2可以抵抗TNF-α对成骨细胞的抑制作用.     

TGF-β1和TNF-α协同刺激诱导人支气管上皮细胞优化上皮间质转化模型

目的探索转化细胞生长因子-β1(transforming growth factor-β1,TGF-β1)和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)协同刺激诱导人气管上皮细胞(human bronchial epithelial cell,HBE)细胞,优化上皮间质转化细胞模型的效果。方法采用空白对照、TGF-β1 10 ng/ml、TNF-α10 ng/ml、TGF-β1 10 ng/ml+TNF-α10 ng/ml刺激诱导HBE细胞24 h后,观察细胞的变化。采用CCK8、细胞迁徙、蛋白印迹实验来实现。结果 TGF-β1+TNF-α协同诱导下大多数细胞从鹅卵石样形态变化为梭形、边界消失、间隙明显增宽。空白对照组、TGF-β1 10 ng/ml组、TNF-α10 ng/ml组、TGF-β1 10 ng/ml+TNF-α10 ng/ml组的细胞迁移距离分别为(420.06±10.38)μm、(499.86±34.00)μm、(514.93±10.56)μm和(569.68±33.58)μm。TGF-β1+TNF-α组与对照组、TGF-β1、TNF-α的差异有统计学意义(P0.05)。TGF-β1+TNF-α协同诱导时,上皮标志物E-cadherin明显降低,间质标志物Vimentin明显升高。结论在HBE细胞中采用TGF-β1和TNF-α协同诱导可以优化细胞上皮间质转化模型。     

兔颈动脉无缝线胶黏吻合与传统缝线吻合的对比研究

目的　对比研究兔颈动脉无缝线胶黏吻合与传统缝线吻合的手术操作情况和吻合口通畅情况。方法　将 16只新西兰大白兔随机分为对照组和实验组 ,记录每个吻合口的吻合时间及出血量 ,术后 1、2、4、12周分别取材观察其通畅情况 ,并对吻合口内膜增生情况行病理切片和计算机图像分析。结果　与对照组相比 ,实验组的手术时间明显缩短 [(8.19± 6.5 1)min比 (2 0 .5 0± 14 .3 5 )min] ,术中出血量明显减少 [(2 .44± 5 .83 )ml比 (10 .3 8± 17.49)ml] ,通畅率也较高 (93 .8%比87.5 % ) ,内膜增生程度明显减轻 ,术后 1、2、4、12周时其内膜厚度分别降低了 3 1.4%、2 4.5 %、2 3 .9%和 3 1.9% (P <0 .0 1) ,其内膜面积分别降低了 3 6.2 %、2 9.1%、3 1.3 %和 40 .0 % (P <0 .0 1)。结论　中小血管的无缝线胶黏吻合较传统的缝线吻合操作省时省力 ,术中出血少 ,避免了缝针和缝线对血管吻合口处的透壁性损伤 ,消除了缝线等异物对管壁的持续性刺激所致的增生性反应 ,使吻合口处内膜增生减轻 ,吻合口通畅率提高。     

不同肠内营养液与生长激素联合应用对烫伤大鼠炎性反应的影响

目的 了解标准肠内营养(EN)、肠内免疫营养(EIN)液与重组人生长激素(rhGH)联合应用对烫伤大鼠炎性反应的影响. 方法 将128只SD大鼠按随机数字表法分为EN、EIN、EN+rhGH、EIN+rhGH组,每组32只.将大鼠制成总面积30%TBSA的Ⅲ度烫伤模型,分别于伤后1、4、7、10 d抽取各组大鼠静脉血,检测血清内毒素、白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)水平;切取大鼠肝组织检测其CD14 mRNA、TNF-α mRNA的表达.另取8只SD大鼠作为对照组,检测上述指标. 结果 伤后各组各时相点大鼠血清内毒素、IL-6、TNF-α水平以及肝组织中的CD14 mRNA、TNF-α mRNA表达均高于对照组(P＜0.01).伤后4、7、10 d,EIN组和EN+rhGH组血清内毒素、IL-6、TNF-α水平以及肝组织CD14 mRNA、TNF-α mRNA表达均低于EN组(P＜0.05或P＜0.01);伤后10 d,EIN+rhGH组血清内毒素[(0.37±0.07)EU/mL]、IL-6[(289±49)ng/L]、TNF-d[(1.87±0.32)μg/L]水平以及肝组织CD14 mRNA(0.39±0.05)、TNF-α mRNA(0.47±0.03)表达均低于EIN组[(0.48±0.08)EU/mL、(364±53)ng/L、(2.50±0.48)μg/L、0.67±0.06、0.66±0.05,P＜0.05或P＜0.01]. 结论 EN、EIN液与rhGH联合应用可减轻大鼠烫伤后的炎性反应,且rhGH具有明显的协同作用.     

下肢静脉性溃疡大鼠模型建立与评价

目的:建立下肢静脉性溃疡大鼠模型并进行评价。方法:在大鼠建立下肢深静脉血栓模型基础上,采用局部皮肤缺损的方法建立溃疡模型。将20只大鼠随机分为对照组、模型组,观察模型大鼠的外部体征和行为学表现,创面组织病理变化,以及血清中IL-6、IL-1β、TNF-α的表达。结果:对照组7 d溃疡面积为(0.83±0.04)cm~2、14 d为(0.49±0.03)cm~2,7 d溃疡愈合率为(13.1±1.8)%、14 d为(47.7±5.5)%。模型组7 d溃疡面积为(1.48±0.09)cm~2、14 d为(1.23±0.07)cm~2,7 d溃疡愈合率为(16.02±5.55)%、14 d为(30.43±4.06)%。模型组在溃疡面积上明显大于对照组;模型组在创面愈合率上明显低于对照组(P0.05)。组织病理学提示,模型组有大量炎细胞增生,纤维结缔组织增生明显。对照组可见少量炎性细胞浸润及坏死中性粒细胞。大鼠在成模后,一般状态良好,活动自如,体质量减轻,创面溃疡部分有愈合,面积较之前缩小。模型组成功率为80%,对照组成功率为100%。在大鼠7 d、14 d血流变及血浆D-二聚体的化学检测对比中得出结果,模型组各项数值均高于对照组;在模型组大鼠7 d、14 d血清IL-1β、IL-6和TNF-α浓度均高于对照组。结论:下肢静脉性溃疡大鼠模型建立成功。     

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.