中国Alport综合征一家系的基因突变检测与临床表型分析

目的:应用高通量测序技术,检测一个中国遗传性肾病家系的致病基因突变,探讨靶区域捕获和高通量测序方法在遗传性肾病基因筛查中的可行性。方法:收集家系临床资料和外周血样本;分析先证者的临床资料,并观察肾穿组织病理,采用目标区域捕获和高通量测序技术,对先证者355个遗传性肾病相关基因的外显子进行突变筛查;应用Sanger测序,在其他家庭成员中进行突变位点验证及突变-表型共分离分析,并对突变位点进行多物种的保守性分析。结果:结合临床检验结果和肾活检病理观察,先证者符合慢性肾小球肾炎,不排除Alport综合征的可能。基因筛查发现,该家系可确诊为X染色体显性遗传Alport综合征,家系中所有女性患者均为X染色体COL4A5基因c.3641GA(p.Gly1214Glu)杂合突变,而男性患者均为该位点的半合子。且该位点在多个物种中具有高度的序列保守性。结论:该遗传性肾病家系是X染色体显性遗传Alport综合征,致病突变位点为COL4A5 c.3641GA(p.Gly1214Glu)。靶区域捕获和高通量测序技术成本低、高通量、准确性高,适用于遗传性肾病家系的基因突变筛查。     

高分辨率HLA-DRB基因型分析方法的研究

目的 采用焦磷酸微测序技术，建立一种高通量、高分辨率的HLA-DRB基因型分析新方法，为临床应用提供依据。方法 对HLA-DRB外显子2DNA序列进行同源性分析，设计PCR引物，提取健康人外周血淋巴细胞基因组DNA，PCR扩增外显子2基因片段，克隆构建含有外显子2的重组质粒pMD／DRB3＊02023。扩增产物经链亲和素包被磁珠纯化、变性、分离制备单链DNA测序模板，采用PSQ96焦磷酸测序仪进行实时测序，分析判断HLA-DRB基因型。结果 扩增并克隆了HLA-DRB外显子2，焦磷酸微测序结果与克隆质粒常规测序结果比较，测序正确，与HLA数据库基因序列比较，可准确进行HLA-DRB基因型分析。采用重组质粒pMD／DRB3＊02023和pMD／DRBl＊0405等比例混合模拟杂合子基因型，焦磷酸微测序分析获得预期结果。结论焦磷酸微测序技术应用于HLA-DRB基因型分析具有高分辨率和快速等优点，可有效分析杂合子基因型，该新方法有望应用于器官及骨髓移植的供体／受体筛查。     

西北高原汉族人群人类白细胞抗原-A、B、DRB1基因多态性与慢性肾衰竭相关性分析

目的：研究西北高原汉族人群人类白细胞抗原(human leukocyte antigen,HLA)-A、B、DRB1基因多态性与慢性肾脏疾病(chronic kidney disease,CKD)的相关性。方法选择410例等待肾移植的CKD患者和403例健康个体作为研究对象,且所有研究对象均来自中国西北高原地区并在当地生活多年。采用序列特异引物聚合酶链式反应技术对研究对象进行基因分型,比较两个群体HLA-A、HLA-B和 HLA-DRB1基因频率的差异,并采用相对风险系数评价 HLA与CKD的相关性。结果与健康对照组比较,CKD 组 HLA-A?32(2.43%比0.37%,P=0.001;odds ratio [OR]=6.692,confidence interval [CI]：1.981~22.608)、HLA-A?68(2.07%比0.37%,P=0.002;OR=5.667,CI：1.654~19.412)和HLA-DRB1?16(3.41%比0.87%,P=0.001;OR=4.035;CI：1.753~9.292)具有高频率,而HLA-B?14(0.36%比1.48%,P=0.02;OR=0.243;CI：0.068~0.864)却频率较低。结论西北汉族人群中,HLA-A?32、HLA-A?68和 HLA-DRB1?16可能是 CKD 的易感基因,而HLA-B?14则可能是保护性基因。     

HLA-DR、DQ基因与肾移植术后糖尿病的相关性的研究

目的探讨肾移植术后糖尿病与HLA-DR、DQ基因的相关性。方法28例患者肾移植术后并发糖尿病,术前进行了HLA分型。另以同期进行HLA分型肾移植术后无糖尿病的患者132例作为对照,二者在性别构成比及年龄方面的差异无统计学意义。术后采用环孢素A(CsA)、硫唑嘌呤和泼尼松(Pred),或采用CsA、霉酚酸酯和Pred预防排斥反应。结果HLA-DRB1*03、DRB1*02、DQB1*03与肾移植术后糖尿病呈显著正相关(相对危险度分别为2.16、1.74和1.99,P值均<0.05)。HLA-DRB3、HLA-DQB1*06与糖尿病发生呈显著负相关(相对危险度分别为0.59和0.55,P值均<0.05)。两种免疫抑制方案间糖尿病发病率的差异无统计学意义(P>0.05)。结论肾移植术后糖尿病的发生与某些HLA基因(糖尿病易感基因)相关。     

胚胎植入前单基因遗传学检测结合HLA配型诊疗X连锁高IgM综合征1例

目的 探讨胚胎植入前单基因遗传学检测(PGT-M)基因突变结合人类白细胞抗原(HLA)配型在X连锁高IgM综合征(X-HIGM)患者临床诊疗中的应用效率及可行性。方法 应用多重PCR结合二代测序技术针对X-HIGM的致病基因CD40LG及临近区域特异性单核苷酸多态性(SNP)位点进行鉴别构建单体型,另外针对HLA-A、HLA-B、HLA-DRA、HLA-DQB1及临近区域特异性SNP位点进行鉴别构建单体型。经本中心常规促排卵、体外受精及胚胎培养,随后进行胚胎活检;对于目标基因CD40LG进行PGT-M,包括直接突变检测和间接单体型连锁分析;对于HLA采用HLA复合体中多个位点的连锁分析来选择相合的胚胎。结果 先证者男孩,临床诊断为X-HIGM,基因检测分析显示其X染色体上的CD40LG基因有1个半合子突变,c.49＿59del(p.L17Hfs*28)。该基因突变会导致X-HIGM。经家系验证发现,先证者母亲在该位点存在和先证者相同的杂合变异。对该家系通过单体型连锁分析之后进行CD40LG基因检测+HLA配型双重PGT。由于先证者母亲卵巢储备不足,只获得3枚卵子,受精后养成的囊胚也只有...     

人类白细胞抗原-DRB1基因多态性与山西省家族性乙型肝炎预后的相关性研究

目的探讨人类白细胞抗原（human lymphoeyte antigen,HLA）-DRB1等位基因多态性与山西省家族性乙型肝炎临床转归及乙型肝炎病毒（HBV）复制状态的相关性。方法采用前瞻性临床流行病学研究方法,以山西省家族性乙型肝炎家庭中的295位成员为研究对象,将其分为健康对照组、慢性无症状携带（ASC）组、慢性乙型肝炎（CHB）组及肝硬化组。采用聚合酶链反应．序列特异性寡核苷酸探针技术（polymerase chain reaction—sequence specific oligonucleotide probe,PCR—SSOP）结合荧光磁珠流式检测技术,进行HLA—DRB1等位基因检测。采用,检验或Fisher’s确切概率计算法比较HLA—DRB1各等位基因频率在各组间以及在HBV DNA不同载量下的分布情况,组间计量资料比较采用方差分析,相关疾病的等位基因风险率以相对危险系数（RR）表示。结果HLA—DRB＊04基因频率在健康对照组为0．159,明显高于ASC组（0．069）和CHB组（0．079）,差异具有统计学意义（χ^2分别为4．892和4．072,P值均〈0．05）;HLA—DRB1＊07等位基因在CHB组和肝硬化组的频率分别为0．131和0．154,明显高于健康对照组（0．049）,差异具有统计学意义（χ^2值分别为4．140和5．529,P值均〈0．05）;HLA—DRB1＊13等位基因频率在健康对照组为0．037,高于CHB组（0）,2组比较差异具有统计学意义（χ^2=3．316,P〈0．05）。HLA—DRB1＊15等位基因频率在ASC组为0．206,在肝硬化组为0．115,2组比较差异具有统计学意义（χ^2=4．287,P〈0．05）。其他各等位基因频率在各组间差异无统计学意义。患者年龄在ASC、CHB及肝硬化3组间的差异有统计学意义（F=33．38,P〈0．01）;HBV DNA阳性组的HLA—DRB1＊07基因频率（0．167）高于HBV DNA阴性组（0．096）（χ^2=5．268,P=0．002）。结论HLA—DRB1＊07与家族性HBV易感性有关,可能是山西省家族性乙型肝炎易感基因或连锁基因。HLA—DRBI＊04及HLA—DRB1＊13与家族性乙型肝炎抗性相关,可能是山西省家族性乙型肝炎抗性基因。     

COL1A1新发突变致儿童成骨不全症 1 例报道并文献复习

目的分析一例I型成骨不全症(osteogenesis imperfecta,OI)患儿的临床特点,并研究患者及其家系的基因突变情况及致病性鉴定。方法详细询问病史,分析骨转换指标、骨密度、骨骼X线特点。采用高通量测序法,对患儿骨病检测包225个相关致病基因各外显子编码区域的序列变异情况进行检测分析,采用PCR结合Sanger测序的方法验证突变位点变异情况。结果骨标志物提示高转换水平,影像学提示骨量低下,四肢长骨纤细、骨皮质变薄,基因检测发现患儿COL1A1基因编码区杂合变异c.2911_2912insAG(p.G971Efs*138),经Mutation Taster预测显示为致病性突变。先证者母亲、父亲以及妹妹均未携带该突变基因。结论发现了OI患者COL1A1基因新的突变位点c.2911_2912insAG(p.G971Efs*138),丰富了中国人OI群体COL1A1基因致病突变谱。     

南方汉族等候肾移植终末期肾功能衰竭患者HLA基因多态性分析

目的对我国南方地区3911例等候肾脏移植的患者进行HLA-A，B，DRB1基因表达的回顾性研究，以探讨在因肾脏疾病导致患者最终并发终末期肾功能衰竭（EsRD）进程中的HLA免疫遗传易感性及其相对风险作用。方法采用聚合酶链反应-序列特异性引物扩增（PcR-SSP）技术进行HLA-A，B，DR基因分型，应用SPPS13．0软件包统计分析ESRD患者中HLA抗原频率、基因频率、HLA—A，B，DR三个位点的单倍型频率（HF）、连锁不平衡参数、相对危险度（RR）及优势比（OR）。结果ESRD患者中表达出HLA-A抗原19个，HLA-B抗原40个，HLA-DR抗原14个；其中呈现抗原频率显著增高（Pc〈O．0001，Pc值即P值乘以所检测的某一位点的抗原数）的是HLA-B75（RR=1．222，OR=1．479）、DR4（RR=1．146，OR=1．294），DR17（RR=1．541，OR=2．639）；呈现出抗原频率显著降低（Pc〈0．0001）的是HLA-DR8（RR=0．812，DR=0．697）、DR9（RR=0．878，OR=0．793）；ESRD患者中具有显著连锁不平衡单倍型（HF〉0．5％）10条，分别为A1-B37．DR10，A2-B7-DR17，A29-B7-DR10，A30-B13-DR7，A33-B13-DR17，A33-B44-DR17，A33-B46-DR17，A33-B58-DR17，A33-B60-DR17和A33-B75-DR17，其中A33-B75-DR17、A33-B58-DR17频率高达7．93％和11．74％。结论研究发现HLA-B75、DR4和DR17可能对南方地区肾脏疾病患者最终并发ESRD具有独立易感关联，而表达HLA-DR8、DR9的肾脏病患者将可能不易并发ESRD；单倍型A33-B75-DR17高频率出现说明HLA-B75，DR17不仅具有独立易感作用还可能对肾脏病患者最终并发ESRD具有集合易感作用。这个发现对于等候肾脏移植患者选择合适供体以提高移植后患者生存时间和远期移植效果具有临床指导意义。     

循环肿瘤DNA监测转移性乳腺癌治疗过程中肿瘤负荷量动态变化的探索性研究

目的探讨转移性乳腺癌患者在接受治疗过程中利用高通量测序技术进行循环肿瘤DNA（ctDNA）检测的价值。 方法通过目标区域捕获结合第二代高通量测序技术,对转移性乳腺癌患者在进行治疗期间不同治疗节点的ctDNA进行测序,并与临床影像学指标进行对比。 结果本研究共纳入5例转移性乳腺癌患者不同时间点的13份血液样本。利用二代高通量测序技术成功在12份（92.3%）样本中检测出ctDNA,联合生物信息学分析出ctDNA在治疗过程中的各个突变克隆的变化趋势。 结论二代测序技术对检测转移性乳腺癌的突变谱有应用价值,ctDNA的动态变化能有效反映转移性乳腺癌患者在治疗过程中不同时期的肿瘤负荷量变化。     

人类白细胞抗原等位基因与慢性乙型肝炎聚乙二醇化干扰素疗效的相关性研究

目的 探讨人类白细胞抗原(HLA)-DRB1等位基因与聚乙二醇化干扰素(PEG-IFN)抗HBV应答的相关性.方法 应用聚合酶链反应-序列特异性引物(PCR-SSP)技术对青岛地区46例慢性乙型肝炎患者HLA-DRB1进行等位基因多态性分析.结果 30例有应答者HLA-DRB1*15等位基因频度(46.67%)高于16例无应答者(12.5%),RR=6.125,P=0.021; HLA-DRB1*07的分布则相反(26.67%对75%,RR=0.121,P=0.002).结论 推测HLA-DRB1*15可能与PEG-IFN的高应答有关, HLA-DRB1*07可能与PEG-IFN低应答有关.     

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.     

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.     

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.     

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.     

The analgesic effect of racemic ketamine in patients with chronic ischemic pain due to lower extremity arteriosclerosis obliterans

Background : Ketamine in sub-dissociative doses has been shown to have analgesic and phantom-Limb pain, where conventional treatment has often failed. Chronic ischemic pain due to lower extremity arteriosclerosis obliterans often responds poorly to analgesics, and the pain-generating mechanisms are not well understood.
Methods : Eight patients with rest pain in the lower extremity due to arteriosclerosis obliterans were given sub-dissociative doses of 0.15, 0.30, or 0.45 mg/kg racemic ketamine and morphine 10 mg as a 5-min infusion on four separate days in a cross-over, double-blind, randomised protocol. Plasma levels of (S)- and (R)-ketamine and their nor-metabolites were analysed with an enantioselective high-performance liquid chromatography (HPLC) method. Pain levels were evaluated with a visual analogue scale (VAS).
Results : Individual pain levels were highly variable during and after all the infusions but the pooled pain levels showed a dose-dependent analgesic effect of ketamine with a transient but complete pain relief in all patients at the highest dose (0.45 mg/ kg). Side-effects, mainly disturbed cognition and perception, were pronounced and dose-dependent. Morphine 10 mg had an analgesic peak at 20 min and 5/8 patients had complete pain relief. The remaining 3 patients also had high baseline pain scores, indicating a higher analgesic potency for the 0.30 and 0.45 mg/ kg ketamine doses than for morphine 10 mg.
Conclusion : We have demonstrated a potent dose-dependent analgesic effect of racemic ketamine in clinical ischemic pain. Due to a narrow therapeutic window, this analgesic effect is probably best utilised in combination with other analgesics.