热CO2气腹对胃癌细胞杀伤作用的实验研究

目的:体外研究热CO2气腹对人胃癌细胞SGC-7901的杀伤作用,探讨临床上腹腔镜胃癌手术使用热CO2气腹抑制腹膜转移和戳孔种植的可行性。方法:建立体外热CO2气腹实验模型,人胃癌细胞SGC-7901经热CO2气腹(42℃、43℃,1～3 h)处理后,WST-8法检测细胞毒作用,流式细胞术定量分析、Hoechst 33342/PI荧光显微镜观察细胞形态,RT-PCR检测Bax、bcl-2基因mRNA的表达。结果:WST-8法检测显示热CO2气腹能显著抑制人胃癌细胞SGC-7901增殖,43℃作用3 h后,细胞存活率降至(65.83±2.40)%。流式细胞术及细胞形态学结果显示,诱导胃癌细胞凋亡是热CO2气腹作用的主要方式,与温度和作用时间呈正相关。RT-PCR检测结果显示,实验组(43℃,3 h)Bax基因mRNA表达水平显著高于对照组(25℃,3 h)差异有统计学意义(P<0.05);但对bcl-2的表达无明显影响。结论:热CO2气腹通过诱导细胞凋亡对人胃癌细胞有显著的增殖抑制作用,发生机制可能是通过上调Bax的表达促进细胞凋亡。     

抗Fas单克隆抗体诱导人胃癌细胞系SGC-7901细胞凋亡的研究

目的 探讨抗Fas单克隆抗体诱导胃癌细胞凋亡的规律及在胃癌治疗中的意义。方法 应用细胞形态观察、琼脂糖凝胶电泳、流式细胞光度术检测抗Fas单克隆抗体对胃癌细胞SGC-7901增殖周期的影响以及对细胞杀伤作用的方式，并检测了SGC-7901细胞表面bcb2的表达情况。结果 抗Fas单克隆抗体有阻滞细胞周期、通过诱发凋亡而抑制肿瘤细胞生长的作用。经抗Fas单克隆抗体处理后，SGC-7901细胞表面bcl-2蛋白表达无明显变化。结论 抗Fas单克隆抗体可以诱导胃癌细胞系SGC-7901细胞凋亡，抗Fas单克隆抗体诱导胃癌细胞凋亡与bcl-2表达无关。     

舒芬太尼对胃癌SGC-7901细胞活力的影响

目的通过不同浓度的舒芬太尼作用于胃癌SGC-7901细胞,研究舒芬太尼对胃癌细胞活力的影响。方法将对数生长期的胃癌细胞随机均分为对照组(C组)、舒芬太尼0.5nmol/L组(0.5nM组)、5nmol/L(5nM组)、50nmol/L(50nM组)和500nmol/L(500nM组)。分别以0、0.5、5、50、500nmol/L浓度的舒芬太尼作用于胃癌细胞,FDA/PI荧光双染观察染毒后的胃癌SGC-7901细胞存活情况;CCK-8试剂盒检测细胞活力;AnnexinV-FITC流式细胞术检测胃癌细胞的凋亡情况;最后运用细胞周期检测试剂盒分析胃癌细胞的细胞周期。结果 FDA/PI双染观察显示,随着舒芬太尼染毒浓度的增高,死亡的胃癌SGC-7901细胞比例不断增加,存活的正常细胞比例下降;CCK-8分析表明药物作用后的胃癌细胞的活力呈下降趋势,与C组比较,12h时500nM组和24、48h时50、500nM组细胞活力明显下降(P0.05或P0.01)。与C组比较,5nM组、50nM组和500nM组细胞凋亡率明显升高(P0.05或P0.01)。运用AnnexinV-FITC/PI凋亡实验发现胃癌细胞凋亡和死亡的数量也随药物浓度的增加而不断增多;最后通过检测染毒后的胃癌细胞,发现与C组比较,5nM、50nM和500nM组G2/M期细胞比例明显升高,S期细胞比例明显降低(P0.01)。结论舒芬太尼可以使胃癌SGC-7901细胞的活力下降,促进胃癌细胞凋亡。     

FasL、B7-1联合基因修饰的胃癌细胞诱导抗胃癌主动免疫的研究

目的 探讨FasL、B7-1联合基因转移是否具有协同的抗肿瘤效应。方法 采用重组腺病毒载体将FasL、B7-1基因导入人胃癌细胞SGC-7901,G418阳性克隆筛选,流式细胞分析,逆转录-聚合酶链反应(RT-PCR),显示FasL和B7-1的表达,并且通过Hoechst33342染色检测胃癌细胞凋亡;将携带 FasL和 B7-1基因的胃癌细胞(命名为 SGC-7901/FB-11)接种于 C57BL/6小鼠背部皮下,观测其致瘤性能;SGC-7901/FB-11致敏的小鼠对野生型瘤细胞是否具有免疫保护作用;用SGC-7901和 SGC-7901/FB-11细胞分别经腹腔免疫小鼠,得到腹腔浸润淋巴细胞及致敏脾细胞,MTT法检测其体外杀伤实验。结果 FasL和B7-1基因在胃癌细胞中获得高表达并可诱导胃癌细胞的凋亡,双基因转染的胃癌细胞的致瘤性明显下降;SGC-7901/FB-11诱导的细胞毒T淋巴细胞(CTL)对SGC-7901的杀伤活性显著高于野生型SGC-7901诱导的CTL对相同靶细胞的杀伤活性(P<0.05);SGC-7901/FB-11诱导的 CTL对 SGC-7901/FB-11的杀伤率显著高于对野生型 SGC-7901的杀伤率(P<0.05)。结论 FasL促进胃癌细胞凋亡,B7-1促进抗胃癌CTL的增殖、活化,在效应阶段两基因发挥着重要的协同作用。     

索拉菲尼对人胃癌细胞SGC-7901增殖、凋亡和P-ERK表达的影响

目的：探讨多分子靶向药物索拉菲尼（sorafenib）对体外人胃癌细胞SGC-7901增殖、凋亡的影响及对癌细胞P-ERK表达的影响,并探讨其可能机制。 方法：以MTT法检测索拉菲尼对SGC-7901细胞的杀伤抑制作用;免疫细胞化学法检测胃癌细胞内P-ERK蛋白的表达;流式细胞仪检测胃癌细胞凋亡的变化情况。 结果：索拉菲尼对胃癌细胞生长增殖具有抑制作用,随药物浓度的增加作用也增强,呈剂量—时间双效应关系(P<0.05);经索拉菲尼处理的SGC-7901细胞的P-ERK表达明显下降(P<0.05);细胞凋亡率增高(P<0.05)。 结论：sorafenib在体外对SGC-7901细胞具有明显的抑制作用,主要机制为抑制其P-ERK表达,从而抑制其增殖和促进凋亡。     

塞来昔布对胃癌SGC-7901细胞凋亡与Fas/FasL表达的影响

目的 观察选择性环氧合酶2抑制剂塞来昔布体外诱导胃癌SGC-7901细胞凋亡的作用及其机制.方法 用吖啶橙/溴化乙啶染色结合荧光显微镜、流式细胞仪(FCM)技术观察不同浓度的塞来昔布对胃癌SGC-7901细胞凋亡的影响,用流式细胞仪技术榆测Fas和FasL.蛋白表达.结果 荧光染色法显示塞来昔布在15～120 μmol/L时诱导胃癌SGC-7901细胞凋亡,且呈浓度和时间依赖性.FCM显示不同浓度的塞来昔布作用SGC-7901细胞48 h后.凋亡率分别为8.02%～50.81%,呈浓度依赖性.塞来昔布上凋胃癌SGC-7901细胞Fas蛋白的表达,下调FasL蛋白的表达.结论 塞来昔布可诱导胃癌SGC-7901细胞凋亡;Fas/FasL表达的改变可能是塞来昔布诱导胃癌SGC-7901细胞凋亡的机制之一.     

慢病毒介导的双自杀基因诱导胃癌细胞凋亡的研究

目的 观察慢病毒介导的KDR启动子驱动的CD/TK双自杀基因体系对胃癌细胞SGC-7901的体外杀伤作用.方法 用重组慢病毒FGW-KDRP-CD/TK体外感染SGC-7901细胞.噻唑蓝(MTT)比色法检测前药对细胞的杀伤效应;透射电镜及流式细胞术观察细胞凋亡及细胞内DNA含量.结果 慢病毒的感染率随病毒滴度的增高而递增.当前药更昔洛韦(GCV)为100 mg/L、5-氟胞嘧啶(5-FC)为320 mg/L时,对未转基因及转基因细胞的抑制率分别为18%、94%,两者筹异有统计学意义(P<0.01).电镜下用药组出现细胞凋亡.流式细胞仪检测显示,随着药物浓度的增加,凋亡细胞所占的比例逐渐增加.结论 KDR启动子可调控双自杀基因系统选择性杀伤SGC-7901细胞,并且该体系可以诱导胃癌细胞凋亡.     

塞来昔布联合顺铂对SGC-7901人胃癌细胞凋亡及Bcl-2表达的影响

目的:探讨选择性环氧化酶-2(COX-2)抑制剂塞来昔布联合顺铂对SGC-7901人胃癌细胞生长、凋亡及Bcl-2表达的影响.方法:终浓度为100、200及300 μmol/L的塞来昔布作用于SGC-7901入胃癌细胞24 h后加入顺铂(2.0 μg/mL),采用M开比色法测定细胞的生长抑制率,流式细胞仪检测细胞周期、细胞凋亡率及Bcl-2表达水平.结果:不同浓度的塞来昔布对SGC-7901人胃癌细胞均有抑制作用,抑制率与对照组相比.差异有统计学意义(P<0.05);流式细胞学检测到凋亡峰,细胞阻滞于G0/G1期.同时伴随Bcl-2表达水平下降,其抑制作用呈时间-剂量依赖性,且以上抑制作用与顺铂具有协同作用.结论:塞来昔布能促进顺铂诱导胃癌细胞凋亡,进而抑制胃癌细胞的增殖,这可能是COX-2抑制剂抗肿瘤的机制之一.     

RNA干扰沉默STIL基因表达对胃癌细胞生物学行为的影响

目的 探讨STIL在胃癌中的表达以及沉默STIL基因对胃癌细胞株SGC-7901各生物学活性的影响.方法 采用实时定量PCR（qPCR）法和Western Blot法检测STIL在胃癌及癌旁组织中的表达.构建靶向STIL的SiRNA并转染SGC-7901细胞,以MTT法检测细胞增殖、平板克隆法检测细胞克隆形成,流式细胞仪检测细胞周期及凋亡.结果 与癌旁组织相比,胃癌组织中STIL在mRNA和蛋白水平表达显著增高.与对照组相比,STIL特异性SiRNA（Si-STIL）转染后,SGC-7901细胞中STIL mRNA表达受到抑制,细胞增殖、克隆形成能力下降,凋亡增加,细胞周期被阻滞于S期.结论 STIL在胃癌组织中高表达,STIL基因沉默可抑制胃癌细胞生长和克隆增殖、抑制有丝分裂期（M期）转换,促进细胞凋亡.     

双链蛋白聚糖对胃癌细胞生长作用研究

目的:研究双链蛋白聚糖(biglycan,BGN)对人胃癌细胞系SGC-7901的细胞增殖、周期及凋亡等生长作用影响。方法:构建重组质粒pIRES2-EGFP/BGN,转染胃癌细胞株SGC-7901,获得胃癌稳转细胞株SGC-7901/BGN。通过细胞增殖实验(CCK-8法)、平板克隆实验、流式细胞技术,分别检察BGN过表达对SGC-7901细胞增殖、克隆形成、周期及凋亡的影响。结果:SGC-7901/BGN组胃癌细胞较SGC-7901/空载组生长明显抑制(P<0.01),细胞培养板形成的克隆数明显减少[(209.7±12.6)比(326.0±15.1)];同时过表达BGN可促进胃癌细胞的凋亡[(10.7±1.5)%比(5.3±1.1)%],且将细胞周期阻止在G1期[(55.7±2.1)%比(37.6±1.8)%]。结论:胃癌细胞过表达BGN可抑制胃癌细胞的增殖、克隆形成。BGN可能通过将细胞周期阻滞在G1期、诱导细胞凋亡,从而发挥其生长抑制的生物学效应。     

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.     

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.     

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.     

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.     

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.