移植抗原特异性转基因CD8+T细胞对白细胞介素2的依赖性

目的研究白细胞介素2（IL-2）在调节移植抗原特异性转基因CD8^＋T细胞介导的免疫排斥反应中的作用。方法将经荧光染科CFSE标记后的C57BL／6小鼠和2CTg小鼠（CD4敲除鼠）淋巴细胞分别植入经致死剂量γ射线照射过的两组DBA／2J小鼠体内，检测CD4^＋与CD8^＋T细胞在体内分裂增殖的时相，并用胞浆内IL-2标志染色方法测定活化后T细胞表达IL-2的能力。以Balb／c小鼠为供者，糖尿病2CTg小鼠和2C Tg-IL-2KO小鼠（IL-2敲除鼠）为受者，进行胰岛细胞移植。观察CD8^＋ T细胞在介导移植排斥中的作用。结果DBA／2J小鼠输注了C57BL／6小鼠的淋巴细胞后，CD4^＋与CD8^＋T细胞分裂增殖均非常明显，前者表达大量IL-2，后者则不表达。DBA／2J小鼠输注了2CTg小鼠的淋巴细胞后。在完全没有CD4^＋T细胞存在的情况下，CD8^＋T细胞仍明显分裂增殖并大量表达IL-2。2CTg和2CTg—IL-2KO小鼠移植胰岛细胞后，前者迅速发生排斥反应，胰岛移植物的平均存活时间仅为8d，而后者胰岛移植物的平均存活时间〉50d。结论CD8^＋T细胞在产生和利用IL-2时有很大的可塑性。CD4^＋T细胞存在时，CD8^＋T细胞能有效利用CD4^＋T细来源的IL-2进行分裂增殖，在缺乏CD4^＋T细胞时，则利用自身来源的IL-2进行分裂增殖；移植抗原特异性CD8^＋T细胞的效应功能完全依赖于IL-2，排斥反应由CD8^＋T细胞介导时，阻断IL-2／IL-2受体通路可诱导移植物长期存活。     

环孢素A联合供者骨髓细胞输注延长大鼠移植心脏存活时间

目的：探讨环孢素A（CsA）联合供者骨髓细胞（DBMC）输注对同种大鼠移植心脏存活时间的影响。方法：制作Lewis大鼠到BN大鼠的异位（腹部）心脏移植模型，并按对受者处理的不同分为四组，对照组不进行特别处理，CsA组术后连续7d给予CsA5mg·kg^-1·d^-1，联合处理组分别于术中及术后第6天输注1×10^8个DBMC，术后连续7d给予CsA5nag·kg^-1·d^-1，DBMC组分别于术中及术后第6天输注1×10^8个DBMC；另设BN大鼠间的心脏移植作为对照（BN对照组）。观察移植心脏的存活时间，观测术后第6天血清白细胞介素2（IL-2）、移植心脏组织中肿瘤坏死因子（TNF-α）mRNA表达以及组织学改变，流式细胞仪检测术后第6、12、18天时受者外周血有核细胞中的供者来源细胞、CD3^＋ CD25^＋细胞、CD4^＋ CD25^＋细胞的百分比以及共刺激分子CD86表达、CD4^＋ CD45RC^＋／CD4^＋ CD45RC^-等。结果：联合处理组移植心脏存活时间为（21．6±3．2）d，明显长于对照组和DBMC组（P〈0．05），其血清IL广2为（313±95）pg／ml，心肌组织中TNF-α mRNA的表达量为0．12±0．10，均明显低于对照组和DBMC组（P〈0．05），排斥反应程度轻于其它3个移植组。联合处理组大鼠外周血有核细胞上CD86表达受到明显抑制；术后6、12d，联合处理组的CD4^＋ CD45RC^＋／CD4^＋ CD45RC^-比值低于对照组和DBMC组，CD3^＋ CD25^＋细胞百分比也低于对照组和DBMC组；接受DBMC输注者外周血中供者来源的有核细胞明显多于未接受DBMC者。结论：短疗程CsA联合DBMC输注能减轻大鼠心脏移植急性排斥反应程度，延长移植心脏存活时间。     

CD4+ CD25+ Treg细胞延长大鼠肾移植术后存活时间的量效关系分析

目的观察肾移植受者（Wistar大鼠）应用供者（SD大鼠）抗原特异性CD4^＋CD25^＋免疫调节性T细胞（CD4^＋CD25^＋Treg细胞）对移植肾存活时间的影响，为CD4^＋CD25^＋Treg细胞在体内应用提供定量分析依据。方法SD大鼠为供者，Wistar大鼠为受者，建立同种肾移植动物模型；免疫磁珠（MACS）法分选Wistar大鼠脾脏CD4^＋CD25^＋T细胞，检测CD4^＋CD25^＋Foxp3^＋T细胞的纯度，并诱导其对SD大鼠供者抗原的特异性表型；根据在肾移植术中经受者尾静脉注射不同数量（2×10^5、5×10^5、1×10^6、2×10^6）的供者抗原特异性CD4^＋CD25^＋T细胞分为：实验Ⅰ、Ⅱ、Ⅲ、Ⅳ组，并以未注射组作为对照。术后观察移植肾的存活时间；监测血肌酐（cr）的水平；按照BanffSchema标准进行移植肾病理诊断，并根据Watanabe的方法进行半定量评分。结果肾移植术后实验Ⅲ组平均存活时间最长，为（31．4±4．6）d，对照组平均存活时间最短，为（11．7±6．2）d；各实验组与对照组间血Cr检测结果比较，差异均有统计学意义（P〈0．05）；实验Ⅲ组和Ⅳ组不同时段的移植肾病理检查半定量评分结果与对照组比较，差异均有统计学意义（P〈0．05）。结论初步证实在受者体内应用适当数量的供者抗原特异性CD4^＋CD25^＋Treg细胞，能够改善移植肾的功能，有效延长大鼠肾移植术后的存活时间。     

全反式维甲酸和三氧化二砷协同诱导胰腺癌细胞凋亡

目的研究与三氧化二砷（As2O2）具有协同效应治疗胰腺癌的药物。方法以胰腺癌细胞系SWl990为研究对象，观察5-氟尿嘧啶（5-Fu）、健择（Gemcitabine）和全反式维甲酸（AT—RA）与As2O3共同作用对细胞的影响。通过台盼蓝拒染法检测细胞生长和细胞活力，流式细胞仪检测AnnexinV或PI阳性细胞的含量，评价以上药物对细胞增殖和凋亡的作用。结果5-Fu和Gemcitabine与As2O3无协同效应。单独应用As2O3或ATRA均抑制SWl990细胞生长，不诱导细胞凋亡。其中，对照组活细胞密度为（8．5±0．3）×10^5个／ml，As2O3组为（4．4±0．1）×10^5个／ml，ATRA组为（6．7±0．2）×10^5个／ml。但是，As203和ATRA共同处理SWl990细胞后，细胞生长明显抑制，并诱导细胞凋亡。对照组活细胞密度为（8．5±0．3）×10^5个／ml，As2O3＋ATRA组为（3．3±0．1）×10^5个／ml；对照组细胞活力为（92，0±1．2）％，As2O3组为（90．0±1．3）％，ATRA组为（93．0±1．4）％，As2O3＋ATRA组为（65．0±2．1）％；对照组Annexin V和PI阳性细胞的含量为（6．0±1．2）％，As2O3组为（11．0±3．3）％，ATRA组为（5．0±1．4）％，As2O3＋ATRA组为（37．0±5．3）％。结论As2O3和ATRA可协同诱导胰腺癌细胞凋亡，两者联合应用可能作为胰腺癌辅助治疗的另一选择。     

恶性梗阻性黄疸经皮肝穿刺胆管内外引流术前后T淋巴细胞亚群、肿瘤坏死因子变化及其意义

目的探讨经皮肝穿刺胭管内外引流术对恶性梗阻性黄疸（MOJ）患者免疫功能的影响。方法将我院2000年11月至2007年3月收治的108例恶性肿瘤致梗阻性黄疸患者按胆汁引流途径分成2组：外引流组52例，内引流组56例。分别于术前1d、术后1周检测肝功能、血清肿瘤坏死因子（TNF-α）及细胞金疫功能指标，观察各指标术前术后的变化，与健康对照组进行比较。结果外、内引流总胆红素（TBIL）分别由术前（344．55±106．57）、（322．20±111．51）／μmolL降为术后1周的（291．57±104．47）、（284．73±105．96）／／L，两组总胆红素均较术前明显下降（P〈0．05），两组间差异无统计学意义（P〉0．05）。TNF-α在外、内引流组分别由术前的（109．59±20．96）、（110．99±17．25）ng／L降为术后的（105．33±20．60）、（84．93±14．44）ng／L，内引流组较术前显著改善（P〈0．01）；内引流组患者术后外周血T淋巴细胞亚群（TLS）CD4^＋、CD3^＋、CD4^＋／CD8^＋值较术前明显增高，术后CD8^＋则明显低于术前（P〈0．05）；而外引流组TNF-α及外周血CD4^＋、CD3^＋、CD8^＋、CD4^＋／CD8^＋与术前比较，差异无统计学意义（P〉0．05），两组问存在明显差异。结论经皮肝穿刺胆道引流术是治疗恶性肿瘤致梗阻性黄疸有效的方法；恶性肿瘤致梗阻性黄疸时全身免疫功能低下，胆道内引流后细胞免疫功能显著改善。     

转化生长因子β不敏感的树突状细胞疫苗对肾癌的免疫治疗作用

目的观察转化生长因子β（TGF-β）不敏感、肿瘤细胞裂解物负载的树突状细胞（DC）疫苗对小鼠肾癌的治疗作用。方法利用修饰的TβRII粒构建逆转录病毒载体，转染肾癌Renca细胞裂解物负载的DC，获得表达显性负相TpRII（TpRIIDN）的DC，流式细胞仪测定细胞表型变化，观察TGF-β体外增殖抑制效果，Western blot检测SMAD-2的磷酸化水平。Renea细胞皮下荷瘤BALB／C鼠40只，随机分TβRIIN—DC组、DC-抗原组、DC组和对照组4组，每组10只，分别给予不同的皮下接种，观察肿瘤体积改变和小鼠生存期。结果经方差分析，TβRIIDN—DC组与DC-抗原组，DC、组的DC细胞CD86、CD80，CD40、CD11c及MHC-Ⅱ表型差异无统计学意义（P＞0．05），TGF-β对TβRIIDN—DC细胞的增殖无抑制作用。在TβRIIDN—DC组未检测到磷酸化SMAD-2。TβRIIDN—DC组、DC抗原组、DC组和对照组的小鼠肿瘤体积分别为（36．27±13．09）、（115．51±20．75）、（218．10±18．93）和（239．21±21．82）mm^3，4组荷瘤小鼠生存期分别为（75．6±10．2）、（44．3±8．5）、（19．0±5．4）和（21．2±6．7）d，其中TβRIIDN—DC组2只小鼠肿瘤完全消失，TβRIIDN-DC组肿瘤体积及荷瘤小鼠生存期与其他各组比较差异均有统计学意义（P＜0．01）。结论TGF-β不敏感的DC疫苗对肾癌荷瘤BALB／C小鼠有明显的免疫治疗作用。     

早期肠内免疫营养对烫伤大鼠免疫功能的影响

目的了解早期肠内免疫营养对烫伤大鼠全身及肠道免疫功能的影响。方法将健康SD大鼠分为标准营养组（EN组）和免疫营养组（EIN组），每组32只。将两组大鼠制成烧伤总面积30％TBSA的Ⅲ度烫伤模型，于伤后1、4、7、10d检测其外周血T淋巴细胞亚群、肠黏膜增殖细胞核抗原（PCNA）表达水平、浆细胞数量及肠黏液分泌型免疫球蛋白A（S-IgA）含量的变化。另取8只健康大鼠检测上述指标作为正常参考值。结果（1）与正常值比较，伤后EN组CD3^＋、CD4^＋、CD4^＋／CD8^＋降低但CD8^＋升高，与各项指标大部分时相点比较，差异有统计学意义（P〈0．05或P〈0．01）。伤后10d与EN组（CD4^＋／CD8^＋为1．26±0．10）比较，EIN组CD3^＋、CD4^＋、CD4^＋／CD8^＋（CD4^＋／CD8^＋为1．86±0．25）升高而CD8^＋下降（P〈0．01）。（2）伤后4、7、10d，EIN组肠黏膜PCNA表达水平、浆细胞数量及肠黏液S-IgA含量较EN组明显升高（P〈0．05或P〈0．01）。结论烫伤后早期给予肠内免疫营养，可以提高全身及肠道免疫功能，效果优于标准肠内营养。     

非小细胞肺癌患者围术期细胞免疫功能的变化及免疫治疗

目的观察围术期非小细胞肺癌患者细胞免疫功能的变化及应用胸腺肽α1后对机体免疫功能的影响,为临床应用免疫增强剂联合手术治疗非小细胞肺癌患者提供依据。方法将97例行肺叶或右全肺切除术的非小细胞肺癌患者分为两组,组1：围术期给予胸腺肽α1治疗;组2：围术期未给予胸腺肽α1治疗;对照组：另选择19例同期非肺癌而采取手术治疗的肺部疾病患者作为对照。采用间接免疫荧光法（IFCA）测定3组围术期T细胞亚群的百分率变化。结果术后第1d组1 CD4^＋T、CD4^＋T／CD8^＋T高于组2（CD4^＋T 36．92％±2．10％ vs．31．18％±7．64％;CD4^＋T／CD8^＋T 1．31±0．36 vs．1．09±0．32;P〈0．05）,术后第3d组1 CD4^＋T和CD4^＋T／CD8^＋T高于组2（CD4^＋T 45．66％±3．77％ vs．34．70％±8．42％;CD4^＋T／CD8^＋T 1．42±0．11 vs．1．14±0．20;P〈0．05）;术后第9d CD4^＋T、CD4^＋T／CD8^＋T高于组2（CD4^＋T 47．28％±1．96％ vs．39．12％±3．10％;CD4^＋T／CD8^＋T 1．46±0．14 vs．1．22±0．36;P〈0．05）;术后第16d组1 CD4^＋T、CD4^＋T／CD8^＋T与组2和对照组比较差异无统计学意义（P〉0．05）。结论非小细胞肺癌患者的免疫功能低下,应用胸腺肽α1后细胞免疫功能较快恢复至正常状态,对非小细胞肺癌患者早期采用手术、化疗／放疗的综合治疗有助于提高治疗效果。     

趋化因子巨噬细胞炎性蛋白-1α基因和B7-1基因共转染诱导大鼠的抗乳腺癌免疫效应

目的观察共转染巨噬细胞炎性蛋白-1α（MIP-α）和B7-1诱导免疫应答的能力和抗乳腺癌免疫治疗的作用。方法7d龄SD大鼠接种乳腺癌细胞后，每天观察有无肿瘤形成；转基因细胞接种荷瘤SD大鼠，观察肿瘤体积的变化及生存期；流式细胞仪检测外周血T细胞亚型，酶联免疫吸附试验（ELISA）法检测白细胞介素（IL）-2及1-干扰素（IFN-1）的含量。结果SHZ-88、B7-1、MIP-α和MIP-α＋B7-1细胞接种10d后致瘤性分别为100％、30％、20％和0；荷瘤大鼠的生存天数分别为53．404±1．14、63．804±1．64、64．204±1．92及（89．004±2.55）d及外周血的CD4^＋、CD8^＋、CD4^＋／CD8^＋比值、IL-2及IFN-1的含量，MIP-1d＋B7-1组均高于其它组（P〈0．05）；接种14、28及40d后，MIP-1α＋B7-1组大鼠的肿瘤体积均小于其它组（P〈0．05）。肿瘤中心或对侧腋窝接种肿瘤细胞，诱导的抗肿瘤效应差异无统计学意义（P〉0．05）。结论共转染MIP-1α和B7-1，可产生协同抗乳腺癌效应。     

大肠癌患者外周血调节性T细胞的检测及临床意义

目的观察大肠癌患者外周血CD4^＋CD25^＋调节性T（Treg）细胞数量的变化，探讨其与肿瘤临床病理特征的关系。方法应用流式细胞仪分析大肠癌患者和健康对照组外周血单个核细胞的Treg细胞数目，比较Treg细胞百分比变化与大肠癌临床病理特征的相关性。结果结直肠癌患者Treg细胞占CD4^＋T细胞百分比（15±8）％，与健康对照组（6．0±3．5）比较，差异有统计学意义（P〈0．01）；CEA正常的结直肠癌患者Treg细胞占CD4^＋T细胞百分比（13±4）％，与CEA升高的结直肠癌患者Treg细胞（17±10）％比较，差异有统计学意义（P〈0．05）；Duke＇s C和D期的结直肠癌患者Treg细胞占CD4^＋T细胞百分比（19±6）％，与A期和B期Treg细胞百分比（12±5）％比较，差异有统计学意义（P〈0．05）。结直肠癌患者外周血TGF-131含量（1．2±0．4）ng／L，与Treg细胞数目呈正相关（r=0．253，P〈0．05）。结论Treg细胞在大肠癌患者中比例升高，可能是产生肿瘤免疫抑制的重要机制，Treg细胞增加可作为大肠癌患者肿瘤进展的重要标志。     

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.     

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.     

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.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Reduction of Plasma Fibrinogen, Immunoglobulin G, and Immunoglobulin M Concentrations by Immunoadsorption Therapy with Tryptophan and Phenylalanine Adsorbents

Abstract Immunoadsorption (1A) therapy with tryptophan (TR-350) or phenylalanine (PH-350) adsorbents has been used to reduce the concentration of serum antibodies in human lymphocyte antigen (HLA)-immunized patients. Other forms of plasma purification have been reported to reduce the level of fibrinogen, which affects the blood properties. In this study we investigated the effects of IA therapy using both adsorbents on plasma fibrinogen and immunoglobulins G and M in 13 patients (8 patients were treated with TR-350, and 5 patients were treated with PH-350). During each session 1 plasma volume (2.8 ± 0.4 L of plasma) was processed through the immunocolumn and then returned to the patient together with the blood cells. Compared with the pretreatment values, the plasma fibrinogen, IgG, and IgM concentrations were significantly reduced after IA therapy (p < 0.01 for TR-350; p < 0.04 for PH-350). There was a positive correlation between the degree of reduction of plasma proteins and the number of IA treatments given. A nonpara-metric test (Wilcoxon's signed-rank test or the Mann-Whitney test) was used for statistical analysis. We conclude from our study that IA therapy effectively lowers the plasma levels of fibrinogen, IgG, and IgM and thus can be considered a valuable alternative to other blood purification methods.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.     

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.