Ⅰ型神经纤维瘤病软骨细胞生物学特性的研究

目的检测神经纤维瘤蛋白在Ⅰ型神经纤维瘤病（type 1 neurofibromatosis，NF1）脊柱侧凸患者软骨细胞中的表达，观察NF1脊柱侧凸患者软骨细胞的生物学特性。方法先天性脊柱侧凸患者7例，NF1脊柱侧凸患者6例，两组年龄和Cobb角接近。脊柱后路手术中取髂骨生长板行软骨细胞分离和培养。取第2代软骨细胞分别检测其增殖活性和Ⅱ型胶原、可聚蛋白多糖等软骨细胞特异性分化指标，并用免疫沉淀和Western blot检测神经纤维瘤蛋白在两组软骨细胞中的表达。结果NF1脊柱侧凸患者软骨细胞中神经纤维瘤蛋白表达水平明显低于先天性脊柱侧凸组（灰度积分比值分别为1．31±0．53和2．17±1．02，P=0．03），其Ⅱ型胶原水平明显低于先天性脊柱侧凸患者组（26．6±11．3ng／mgpro和31．7±16．2ng／mgpro，P=0．03），而可聚蛋白多糖水平两组无明显差异（63．0±129．6ng／mgpro和76．7±519．4ng／mgpro，P=0．21）。NF1脊柱侧凸患者软骨细胞显示相对活跃的增殖活性（增殖倍数分别为2．9±0．04和2．49±0．11，P=0．02）。结论NF1脊柱侧凸患者软骨细胞神经纤维瘤蛋白表达降低的同时，其细胞增值相对活跃，细胞分化功能也存在缺陷。     

Ⅰ型神经纤维瘤病成骨细胞生物学特性的研究

目的检测神经纤维瘤蛋白在Ⅰ型神经纤维瘤病(type1neurofibromatosis,NF1)脊柱侧凸患者成骨细胞中的表达,观察NF1脊柱侧凸患者成骨细胞的生物学特性。方法先天性脊柱侧凸患者10例,NF1脊柱侧凸患者8例,两组年龄和Cobb角相近。脊柱后路手术取髂骨松质骨,采用植块法进行成骨细胞培养。取第二代成骨细胞分别检测其增殖活性、碱性磷酸酶、Ⅰ型胶原和骨钙素等成骨细胞特异性分化指标,并采用免疫沉淀和Westernblot法检测神经纤维瘤蛋白在两组成骨细胞中的表达。结果NF1脊柱侧凸患者成骨细胞中神经纤维瘤蛋白表达水平明显低于先天性脊柱侧凸患者(灰度积分比值分别为1.05±0.06和2.59±1.40,P=0.002);碱性磷酸酶、Ⅰ型胶原和骨钙素水平均明显低于先天性脊柱侧凸患者(44.69IU/mg和51.38IU/mg,P=0.019;226.34ng/mg和249.93ng/mg,P=0.014;7.41ng/mg和8.87ng/mg,P=0.049)。NF1脊柱侧凸患者成骨细胞显示相对活跃的增殖活性(增殖倍数分别为3.34和2.70,P=0.049)。结论NF1脊柱侧凸患者成骨细胞神经纤维瘤蛋白表达降低的同时,其功能存在明显缺陷。成骨细胞功能缺陷可能是骨骼营养不良性改变和骨密度降低等各种骨骼异常共同的基础。     

人髂骨生长板软骨细胞的体外培养及鉴定

[目的]探讨人髂骨生长板软骨细胞体外培养的可行性并观察其生物学特征。[方法]对手术中获得的10例青少年特发性脊柱侧凸患者髂骨生长板软骨行体外分离、培养，观察细胞形态，MTT法测定细胞增殖，Ⅱ型胶原免疫组化染色，采用逆转录聚合酶链反应检测各代细胞Ⅱ型胶原mRNA的表达水平。[结果]（1）体外培养的软骨细胞随着传代次数的增加，细胞形态由原代的多角形逐渐变为长梭形；（2）MTT比色法检测显示，第2代髂软骨细胞的生长曲线近似倒“S”形，在第4～8d细胞呈对数生长，在9～10d达平台期，至第11d开始出现生长抑制。（3）第2代细胞Ⅱ型胶原免疫组化呈强阳性。（4）Ⅱ型胶原mRNA表达水平从第2代后随着传代次数的增加逐渐下降。[结论]采用联合酶序贯消化法将软骨细胞悬液和软骨块共同体外培养髂软骨细胞简单、有效，P2代细胞很好的保持了软骨细胞的特性，可以作为种子细胞来源。     

植块法在成骨细胞培养中的应用

目的：探讨植块法培养成骨细胞的可行性。方法：取10例先天性脊柱侧凸患者髂骨松质骨，应用植块法分离培养成骨细胞。培养过程中观察细胞形态学变化，并用碱性磷酸酶染色、RT-PCR检测Ⅰ型胶原和骨钙素表达、骨钙素免疫荧光检测、钙结节观察等方法对培养细胞进行鉴定。结果：应用植块法培养获得了较多的原代细胞，光镜下呈典型的成骨细胞形态，碱性磷酸酶染色、Ⅰ型胶原和骨钙素表达及钙结节形成等观察结果均证实所培养细胞表现成骨细胞特性。结论：植块法成骨细胞培养体系方法简单，在获得大量原代成骨细胞的同时，较好地保持了其生物学特征，是一种较理想的人成骨细胞培养方法。     

Ⅰ型神经纤维瘤病营养不良性脊柱侧凸患者椎体生长板软骨细胞的功能变化及意义

目的:观察Ⅰ型神经纤维瘤病(NF1)营养不良性脊柱侧凸患者椎体生长板软骨细胞的功能变化,探讨其在脊柱营养不良性改变中的作用。方法:共有8例NF1营养不良性脊柱侧凸患者纳入本研究,男5例,女3例,年龄9~15岁,平均11.8±2.0岁。在矫形术中取营养不良区(顶椎区,A组)、非营养不良区(端椎区,B组)椎体生长板软骨及髂软骨(C组)。采用两步酶消化结合植块法进行软骨细胞培养。应用Real-time PCR法检测软骨细胞中可聚蛋白多糖、Ⅱ型胶原及神经纤维瘤蛋白的mRNA表达。结果:A组软骨细胞中可聚蛋白多糖mRNA的表达量为0.04±0.02,B组为0.09±0.04,C组为0.13±0.07,A组显著低于B组和C组(P<0.05)。A组Ⅱ型胶原的mRNA表达量为0.91±0.04,B组为0.96±0.07,C组为1.03±0.10,A组显著低于C组(P<0.05),A组与B组差别无统计学意义(P>0.05)。A组神经纤维瘤蛋白的mRNA表达量为0.39±0.30,B组为1.34±0.63,C组为1.00±0.51,A组较B、C组均明显降低(P<0.05)。各指标在B组与C组间均无统计学差异(P>0.05)。结论:NF1营养不良性脊柱侧凸患者营养不良区椎体生长板软骨细胞分化功能存在明显缺陷,其可能是脊柱营养不良性改变的基础。     

青少年特发性脊柱侧凸患者软骨细胞中Sox9的表达及意义

目的:检测转录因子Sox9在青少年特发性脊柱侧凸(AIS)患者软骨细胞中的表达,探讨其在AIS患者生长发育异常中的可能作用.方法:14例(男1例,女13例)年龄10～16岁(平均13.1岁)的AIS患者(AIS组),Cobb角41°～88°,平均51.4°;8例(男1例,女7例)非AIS患者(对照组),年龄10～15岁,平均12.9岁;腰椎骨折1例,脊髓室管膜瘤1例,腰椎间盘突出症1例,脊柱骨样骨瘤1例,先天性髋关节脱位4例.在行手术治疗时获取髂骨生长板软骨,采用酶消化法体外分离、培养、传代,并观察细胞形态;采用Ⅱ型胶原细胞免疫组织化学法对传至P2代的细胞行表型鉴定;采用逆转录-聚合酶链反应(RT-PCR)、蛋白免疫印迹(Western blotting)法检测两组软骨细胞中Sox9 mRNA及蛋白表达情况.结果:酶消化法体外单层培养软骨细胞成功;细胞传至P2代时具有软骨细胞的典型形态特征,呈多角状;Ⅱ型胶原细胞免疫组化染色呈阳性,细胞胞浆内可见棕褐色颗粒,很好地保持了软骨细胞的表型特征;AIS组患者软骨细胞中Sox9核酸表达强度为1.08±0.14,蛋白表达强度为0.38±0.14,均较对照组高(P<0.05).结论:转录因子SOx9在软骨细胞水平表达强度的异常可能与AIS患者生长发育异常有关.     

青少年特发性脊柱侧凸软骨Sox9表达及意义

[目的]检测Sox9及软骨特异性标记物Ⅱ型胶原及Aggrecan在青少年特发性脊柱侧凸(adolescent idiopathic scoliosis, AIS)患者关节突软骨细胞中的表达,探讨其与AIS发生、发展的关系。[方法]收集我院行后路脊柱侧凸矫形术的15例AIS患者的关节突软骨标本,设为AIS组;取同年龄段无脊柱侧凸行脊柱融合术的10例患者正常软骨标本,设为对照组。分别分离软骨细胞体外培养,分别采用RT-PCR,免疫组化,免疫荧光染色和Westen-blotting等方法检测AIS组及对照组软骨Sox9及Ⅱ型胶原及Aggrecan的表达情况,进行两组间比较和AIS组凸侧与凹侧间比较。[结果] AIS组患者软骨细胞内的Sox9及软骨特异性标记物CollagenⅡ及Aggrecan的表达明显高于非AIS组患者。相比于凹侧,AIS患者顶椎凸侧原代软骨细胞中Sox9及软骨特异性标记物CollagenⅡ及Aggrecan表达明显升高。[结论] Sox9在AIS患者体内及原代软骨细胞中的表达异常是AIS患者体内软骨发育异常及脊柱不平衡生长的重要原因,可能是AIS发生、发展的原因之一。     

SOX9、L—SOX5、SOX6及Ⅱ型胶原在青少年特发性脊柱侧凸患者顶椎终板软骨的共表达及意义

目的：观测SOX9、L—SOX5、SOX6及Ⅱ型胶原在青少年特发性脊柱侧凸（adolescent idiopathic scoliosis，AIS）患者顶椎终板软骨中的表达，探讨其与AIS发生、发展的关系。方法：12例AIS患者，每例在前路手术时截取顶椎终板软骨1份，每份标本均包含凸侧与凹侧。切片行HE染色观察其组织细胞形态；行免疫组织化学染色，应用病理图像分析系统观测凸侧与凹侧的SOX9、L—SOX5、SOX6及Ⅱ型胶原表达的阳性细胞数和累积光密度（IOD），并计算这4个因子表达的相关性。结果：HE染色显示终板软骨有类似四肢长骨骺板样软骨内成骨组织形态．与凹侧比较凸侧显示了更强的软骨细胞活性。凸侧SOX9、L—SOX5、SOX6及Ⅱ型胶原表达的阳性细胞数和前三者的IOD值均明显大于凹侧，差异均有显著性（P〈0．05），凸侧Ⅱ型胶原表达的IOD值与凹侧比较无显著性差异（P〉0．05），4个因子表达的阳性细胞数之间的相关系数为0．46-0.91（P〈0．05），IOD之间为0．64～0．98（P〈0．05），均呈正性相关。结论：AIS患者顶椎凸侧与凹侧终板软骨的组织形态学及SOX9、L—SOX5、SOX6和Ⅱ型胶原的表达均存在差异，其可能是脊柱不同部位间机械应力差异下的继发性变化：4个因子的共表达异常触发AIS的可能性小。     

青少年特发性脊柱侧凸患者椎体生长板中Runx2及X型胶原表达

目的：观察青少年特发性脊柱侧凸（AIS）患者上、下端椎和顶椎椎体生长板凸、凹侧软骨细胞的生物活性差异．探讨其在AIS发生和发展中的作用。方法：在对12例AIS患者行胸椎侧凸前路松解手术或前路矫形手术时获取上、下终椎和顶椎椎体生长板，分成凸、凹侧2组，共72枚标本，应用免疫组织化学方法检测Runx2和X型胶原蛋白的表达．原位杂交方法检测Runx2mRNA表达。所有染色结果通过图像分析系统进行半定量分析。结果：AIS患者顶椎椎体生长板凸、凹两侧的X型胶原、Runx2和Runx2 mRNA表达总量存在显著性差异（P〈0．05）。顶椎椎体生长板凹侧X型胶原的表达总量低于下终椎椎体生长板凹侧的表达总量（P〈0．05）。顶椎椎体生长板凹侧Runx2的表达总量低于上、下终椎椎体生长板凹侧的表达总量（P〈0．05）。顶椎椎体生长板凹侧单一软骨细胞Runx2表达量高于凸侧和上、下终椎椎体生长板凹侧单一软骨细胞的表达（P〈0.05）。顶椎椎体生长板凹侧高倍视野下平均Runx2mRNA表达总量低于上、下终椎椎体生长板的凹侧（P〈0．05）。顶椎椎体生长板凸侧单一细胞Runx2 mRNA表达量低于凹侧（P〈0.05）。顶椎椎体生长板凹侧高倍视野下平均X型胶原阳性细胞密度和Runx2阳性细胞密度低于凸侧和上、下终椎椎体生长板凹侧阳性细胞密度（P〈0．05）。结论：AIS患者上、下终椎和顶椎椎体生长板凸、凹侧软骨细胞存在不同的生物活性和细胞动力学，这可能是力学条件改变后的一种继发性改变，但其可能在AIS的进展中发挥重要作用。     

膝关节滑膜间质干细胞分离、培养及其多向分化潜能特性的研究

目的 探讨晚期骨关节炎患者膝关节滑膜间质干细胞(synovium-derived mesenchymalstem cells,SMSCs)体外分离、培养的可行性及其在体外向脂肪细胞、成骨细胞和软骨细胞定向分化的特性.方法 取膝关节滑膜组织,胶原酶消化获得有核细胞.挑选单细胞克隆,筛选获得SMSCs.流式细胞技术检测细胞表面特异性抗原标志.培养至第三代,分别向脂肪细胞、成骨细胞和软骨细胞诱导分化.油红O染色鉴定向脂肪细胞分化;碱性磷酸酶染色、茜素红染色鉴定向成骨细胞分化;甲苯胺蓝染色鉴定向软骨细胞分化.RT-PCR检测脂肪细胞、成骨细胞标志基因.Ⅱ型胶原免疫组化染色检测软骨细胞Ⅱ型胶原的表达.结果 原代SMSCs体外培养呈葵花样细胞集落,传代后可见圆形巨噬样细胞和纺锤形成纤维样细胞,融合后呈成纤维细胞样生长.CD44、CD90呈阳性,CD34、CD71和CD45呈阴性.向脂肪细胞诱导21d,油红O染色阳性;RT-PCR检测有脂蛋白酶、乙二腈及PPARγ2表达;向成骨细胞诱导7、28 d,ALP,茜素红染色阳性,有ALP、Osteopontin及Osteocalcin表达;向软骨细胞诱导21d,甲苯胺蓝染色阳性,Ⅱ型胶原免疫组化染色阳性.结论 晚期骨关节炎患者膝关节滑膜组织可以分离、培养获得SMSCs. SMSCs具有向脂肪细胞、成骨细胞和软骨细胞发生定向分化的潜能.     

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.