不同Pfirrmann分级椎间盘内髓核细胞生物学特性的比较

目的比较不同Pfirrmann分级椎间盘内髓核细胞的生物学特性,验证腰椎间盘退变Pfirrmann分级能否反应髓核组织在细胞水平的退变程度。方法取术中获得的患者的髓核组织,按腰椎椎间盘退变Pfirrmann分级标准进行分组。组织切片甲苯胺蓝观察比较各组髓核内细胞的密度。采用酶消化法分离培养髓核细胞。台盼蓝染色计算各组细胞活性比率,光镜观察细胞形态,透射电镜观察细胞的超微结构。MTT法绘制各组2代细胞的生长曲线。阿利辛蓝法检测各组细胞的蛋白聚糖含量,比较各组差异。结果随退变级别升高,标本内胶冻样物质含量减少,透明度降低,纤维化组织增多,Ⅴ级标本完全纤维化,并伴有钙化,无法区分髓核组织。Ⅰ级和Ⅱ级髓核内细胞密度明显高于Ⅲ级,Ⅳ级又明显高于Ⅳ级。Ⅰ级组髓核细胞的活性比率为（93.5±3.7）%;Ⅱ级组细胞活性比率为（91.6±4.3）%;Ⅲ级组细胞活性比率为（83.5±6.7）%;Ⅳ级组细胞活性比率为（74.8±5.9）%。除Ⅰ级与Ⅱ级比较差异无统计学意义外,其余各组两两比较差异均具有统计学意义（P〈0.05）。光镜下Ⅰ级和Ⅱ级组细胞呈短梭形或多角形轮廓清晰饱满,折光性强。Ⅲ级组胞突较长,Ⅳ级组胞突更长,细胞轮廓模糊。电镜下Ⅰ级和Ⅱ级组细胞相似,胞浆内含有大量粗面内质网和线粒体,Ⅲ级组细胞内的粗面内质网和线粒体减少,出现小的空泡,可见溶酶体出现。Ⅳ级组细胞溶酶体大量聚集,可见巨大的空泡样结构。Ⅰ级组和Ⅱ级组细胞生长速率快于Ⅲ级组（P〈0.01））。Ⅲ级组细胞生长速率快于Ⅳ级组（P〈0.05）。Ⅰ、Ⅱ、Ⅲ、Ⅳ组细胞GAG含量分别为（423.19±41.21）mg/L,（408.23±29.25）mg/L、（273.05±52.44）mg/L、（91.73±38.06）mg/L,Ⅰ级组和Ⅱ级组细胞高于于III级组（P〈0.05））。Ⅲ级组细胞高于Ⅳ级组（P〈0.05）。结论椎间盘退变的Pfirrmann分级,能很好的反映髓核组织在细胞水平的退变程度。是一种简单有效的退变分级系统。     

LOX在人体退变椎间盘髓核组织中的表达及临床意义

目的探讨赖氨酰氧化酶(LOX)在人体退变椎间盘髓核组织中的表达及其临床意义。方法选取自2018-01—2018-12诊治的22例腰椎间盘突出症患者作为观察组,将4例同期突发创伤导致腰椎椎体骨折行手术摘除椎间盘的年轻患者作为对照组。按照椎间盘Pfirrmann分级分组,对照组为Ⅰ级(A组);观察组细分为4组,B组为Ⅱ级,C组为Ⅲ级,D组为Ⅳ级,E组为Ⅴ级。取各组椎间盘髓核组织行免疫组化、Western Blot、PT-PCR检测。结果观察组髓核细胞数量及细胞外基质成分明显少于对照组。LOX在髓核细胞中的阳性表达率与Pfirrmann分级、年龄呈负相关。各组LOX蛋白表达量:A组2.69±0.24,B组2.24±0.32,C组1.34±0.19,D组1.30±0.32,E组1.01±0.12。各组LOXmRNA表达量:A组1.06±0.03,B组0.83±0.07,C组0.71±0.09,D组0.53±0.09,E组0.27±0.05。随着椎间盘退变程度加重,髓核组织LOX蛋白表达水平、mRNA表达水平呈逐渐降低趋势。结论 LOX的蛋白及mRNA表达水平随着人体椎间盘退变程度加重而降低,LOX可能参与了人体椎间盘髓核组织退变的发生与发展过程。     

1-磷酸鞘氨醇受体在不同退变程度髓核组织中的表达变化

目的 :比较不同退变程度人椎间盘髓核组织中3种1-磷酸鞘氨醇受体(S1PR1/2/3)表达水平的差异,探讨椎间盘中S1PR表达水平与椎间盘退变的关系。方法:收集腰椎间盘退行性病变患者手术切除的椎间盘组织,其中轻度退变(Pfirrmann分级Ⅳ级)22例,严重退变(Pfirrmann分级Ⅴ级)14例;同时取6例无椎间盘退变患者(单纯腰椎椎体骨折,Pfirrmann分级Ⅱ级)手术切除的椎间盘组织作为对照组;通过HE染色以及Saf-O染色观察不同退变程度椎间盘的组织学变化,免疫组化检测不同退变程度组织中的S1PR表达水平;Ⅱ型胶原酶消化分离提取原代髓核细胞,通过Real-time PCR、Western-bolt检测不同退变程度椎间盘髓核细胞中S1PR的表达水平,并通过细胞免疫化学方法对S1PR进行定位。结果:HE染色及Saf-O染色结果显示退变椎间盘的纤维环出现破损,髓核细胞形成明显的集落,细胞外基质减少。免疫组化结果显示正常和轻度退变的髓核组织中3种受体(S1PR1/2/3)都有表达,严重退变的组织中表达极弱;Real-time PCR结果显示对照组髓核细胞中S1PR1/2/3的m RNA表达水平分别是严重退变组的5.34±0.52倍、7.25±0.04倍、1.92±0.06倍,轻度退变组S1PR1/2/3的m RNA表达水平分别是严重退变组的4.35±2.45倍、4.96±3.44倍、2.19±0.82倍;Western-blot发现对照组和轻度退变组髓核细胞中S1PR1/2/3均有表达,严重退变组表达水平较低;免疫细胞化学显示S1PR主要集中在髓核细胞的细胞质和细胞膜上。结论:髓核组织中主要表达S1PR1/2/3,在严重退变的髓核组织和细胞中其表达水平明显下降,S1P及其受体可能参与椎间盘髓核组织的退变过程。     

BMSCs-壳聚糖凝胶复合体移植治疗椎间盘退变的实验研究

目的 探讨兔BMSCs-壳聚糖凝胶复合体移植治疗椎间盘髓核缺损退变的效果,为临床应用提供实验依据. 方法 6只健康1月龄新西兰白兔,雌雄不限,体重1.0～1.5 kg.取骨髓2 mL,分离培养BMSCs.取第3代BMSCs,5-BrdU活细胞示踪剂标记,与壳聚糖凝胶混匀,制备BMSCs-壳聚糖凝胶复合体.将6只动物建立兔椎间盘髓核缺损退变模型,并随机分为3组(n=2):正常对照组仅分离暴露椎间盘,不作任何处理;移植治疗组将30 μL自体BMSCs-壳聚糖凝胶复合体注射入缺损椎间盘中心;缺损退变组仅注射入0.01 mol/L PBS液30 μL.移植后4周处死动物,取出移植修复的椎间盘,行细胞5-BrdU标记检测、HE、aggrecan番红.染色及Col Ⅱ免疫组织化学染色;Col Ⅱ免疫组织化学染色切片行灰度值测定. 结果 细胞标记检测发现,自体BMSCs移植后继续存活并增殖,形成细胞克隆.正常对照组及移植组椎间盘HE染色示椎间盘结构清晰,髓核组织及外周纤维环分界清晰,细胞核及细胞浆染色明显;缺损退变组示椎间盘结构紊乱,髓核组织和外周纤维化分界不清.aggrecan番红O染色示正常对照组及移植治疗组椎间盘染色明显,椎间盘结构清晰;缺损退变组椎间盘结构紊乱,髓核组织和外周纤维化分界不清.Col Ⅱ免疫组织化学染色示正常对照组以中央髓核组织染色为主,呈黄褐色阳性反应,椎间盘结构清晰;移植治疗组中央髓核组织呈阳性反应,细胞间质可见明显黄褐色,大体结构仍保持完整;缺损退变组染色较前两组浅,且结构不清.3组Col Ⅱ免疫组织化学染色切片行灰度值测定,正常对照组为223.84±3.93,与移植治疗组(221.03±3.53)比较差异无统计学意义(P>0.05),但两组与缺损退变组(172.50±3.13)比较,差异均有统计学意义(P<0.05). 结论 兔BMSCs-壳聚糖凝胶复合体可修复椎间盘缺损退变,为临床应用可注射式组织工程髓核移植治疗椎间盘退变奠定实验基础.     

白藜芦醇通过Wnt/β-catenin信号通路调控髓核细胞细胞外基质表达

目的探讨白藜芦醇(resveratrol,RES)对退变髓核细胞(nucleus pulposus cells,NPC)细胞外基质(extracellular matrix,ECM)表达的调控作用及其相关分子机制。方法选取临床上接受椎间盘摘除术的10例患者,其中5例为年轻脊柱爆裂骨折患者,作为对照组;余5例为老年腰椎间盘突出症患者,作为退变组。取两组患者髓核组织,免疫组织化学染色比较β-catenin的原位表达,Western blot检测β-catenin、Ⅱ型胶原和聚集蛋白聚糖(Aggrecan)蛋白表达。取退变组髓核组织分离、培养NPC,分别用IL-1β单独(B组)或联合RES(C组)刺激第3代NPC,并设未刺激细胞作为空白对照组(A组),Western blot检测Ⅱ型胶原和Aggrecan蛋白表达。进一步采用小干扰RNA(small interfering RNA,si RNA)靶向沉默SIRT1和β-catenin后,采用Western blot、实时荧光定量PCR检测β-catenin、SIRT1蛋白和基因表达。用完全培养基(1组)、IL-1β(2组)、RES+IL-1β(3组)、SIRT1-si RNA+RES+IL-1β(4组)刺激第3代NPC培养24 h后,细胞免疫荧光染色检测β-catenin核转位情况;用完全培养基(Ⅰ组)、IL-1β(Ⅱ组)、IL-1β+β-catenin-si RNA(Ⅲ组)、IL-1β+RES(Ⅳ组)、IL-1β+RES+SIRT1-si RNA(Ⅴ组)刺激第3代NPC培养24 h后,采用Western blot检测Ⅱ型胶原和Aggrecan蛋白表达。结果免疫组织化学染色及Western blot检测示,与对照组比较,退变组髓核组织中β-catenin阳性表达的细胞比例显著升高(t=4.616,P=0.010);β-catenin蛋白相对表达量显著升高,Ⅱ型胶原和Aggrecan蛋白相对表达量显著下降(P0.05)。细胞学实验发现,B组β-catenin蛋白相对表达量显著高于A、C组,Ⅱ型胶原和Aggrecan相对表达量显著低于A、C组(P0.05)。si RNA转染后,Western blot检测显示SIRT1、β-catenin蛋白表达显著降低(P0.05)。细胞免疫荧光染色结果进一步提示与3组相比,4组SIRT1被si RNA沉默后,RES减弱的β-catenin核转位现象加剧。Western blot检测示,Ⅱ组Ⅱ型胶原和Aggrecan蛋白表达较Ⅰ组明显降低(P0.05);Ⅲ组NPC转染β-catenin-si RNA后,IL-1β对ECM的降解作用被明显抑制,Ⅱ型胶原和Aggrecan蛋白表达较Ⅱ组明显升高(P0.05);Ⅴ组NPC转染SIRT1-si RNA后,抑制了RES对ECM降解的保护作用,Ⅱ型胶原和Aggrecan蛋白表达较Ⅳ组明显降低(P0.05)。结论 RES可以通过抑制Wnt/β-catenin信号通路维持NPC ECM的表达,为椎间盘退行性疾病的治疗提供了新思路。     

兔退变椎间盘中髓核细胞凋亡与BNIP3基因表达的意义

目的髓核细胞凋亡可能与髓核组织代谢障碍产生缺氧,导致BNIP3基因表达有关。通过观察兔退变椎间盘中髓核组织的细胞密度、细胞凋亡率及BNIP3的表达,为进一步了解髓核细胞凋亡机制提供实验依据。方法健康3月龄雄性新西兰大白兔30只,体重(2.3±0.2)kg,随机分为实验组(n=20)及对照组(n=10)。实验组大白兔采用针刺L3、4、L4、5及L5、6椎间盘制备椎间盘退变模型;对照组仅暴露椎间盘后缝合。术后4、8周通过MRI检查评价椎间盘退变情况,采用组织学观察和TUNEL法检查椎间盘髓核组织中凋亡细胞,用免疫组织化学染色法检测兔椎间盘髓核细胞BNIP3的表达。结果 MRI检查示实验组术后4、8周椎间盘髓核信号强度呈逐渐降低趋势。根据Pfirrmann分级标准,实验组术后4、8周椎间盘退变分级比较,差异均有统计学意义(P0.05)。组织学观察及TUNEL检查示:对照组椎间盘髓核中细胞密度高,可见少量散在的凋亡细胞;实验组术后4、8周时椎间盘髓核组织内细胞密度逐渐降低,可见较多凋亡细胞。各时间点实验组细胞密度、TUNEL染色阳性细胞率与对照组比较,以及实验组各指标两时间点间比较,差异均有统计学意义(P0.05)。对照组椎间盘髓核组织细胞中无BNIP3表达;实验组术后4、8周椎间盘髓核组织细胞中BNIP3表达逐渐增多,BNIP3染色阳性细胞率分别为13.45%±1.16%、32.00%±1.82%,BNIP3灰度值分别为194.32±4.65、117.54±2.11,各时间点间比较差异均有统计学意义(P0.05)。结论椎间盘退变与髓核组织中细胞密度下降有关,细胞凋亡是椎间盘髓核细胞减少的原因之一,BNIP3参与了椎间盘髓核细胞凋亡。     

SDF-1/CXCR4信号轴促进退变椎间盘胞外基质降解的研究

[目的]探讨SDF-1/CXCR4信号轴对于退变椎间盘胞外基质的影响及其潜在的作用机制。[方法]分别从年龄相匹配的椎间盘突出症和脊柱骨折手术患者中获取椎间盘组织,通过术前磁共振(MRI)采用Pfirrmann分级对椎间盘样本进行退变程度分组。免疫组化和western blot检测两个组椎间盘组织SDF-1、CXCR4、MMP-3,MMP9,Collagen Ⅱ和Aggrecan的表达。对取自椎间盘突出症患者的组织进行分离,细胞原代培养。取第3~6代细胞加入100ng/ml SDF-1或转染CXCR4小干扰RNA(siRNA)后共培养24 h,荧光定量PCR和western blot检测CXCR4、Collagen Ⅱ和Aggrecan的表达,Annexin V/PI双染法检测细胞凋亡率。为进一步探讨其潜在的分子机制,NF-κB抑制剂PDTC(20μmol/L)或CXCR4-siRNA转染髓核细胞后,观察NF-κB的主要基团P65磷酸化水平(p-P65)及核转移情况,胞外基质的表达和细胞凋亡水平是否发生改变。[结果]通过MRI的Pfirrmann分级标准,椎间盘突出组的分级为Grade Ⅲ~Ⅴ级,而脊柱骨折组的分级为Grade Ⅰ、Ⅱ级,分别定义为退变组和正常组。通过检测两组未进行处理的椎间盘组织发现,SDF-1、CXCR4、MMP-3和MMP-9在退变组中表达增高,而胞外基质的主要成分Collagen Ⅱ和Aggrecan表达则在退变组织中明显降低。而体外细胞实验结果显示,SDF-1处理后CXCR4的表达明显增高,同时伴随细胞凋亡的增高,而Collagen Ⅱ、Aggrecan的表达则显著降低,但这一作用可以随着CXCR4被siRNA靶向沉默后受到明显抑制。作者进一步采用PDTC或CXCR4-siRNA处理细胞后发现,SDF-1可以明显提高p-P65表达水平,促进P65基团的核转移,而这些作用随着CXCR4表达降低而受到抑制。此外PDTC抑制NF-κB活性后,细胞凋亡水平明显下降,而Collagen Ⅱ和Aggrecan的表达则明显上升。[结论]SDF-1/CXCR4信号轴在退变椎间盘中表达增高,它可以促进胞外基质的降解,增加细胞的凋亡水平,其潜在的机制通过调控NF-κB的活性得以实现。SDF-1/CXCR4信号轴有望成为治疗椎间盘退变疾病的潜在靶点。     

细胞凋亡、细胞增殖在人颈椎间盘退变过程中的作用

目的 探讨细胞凋亡、细胞增殖在人颈椎间盘退变过程中的作用以及人颈椎间盘细胞凋亡可能涉及的信号转导途径.方法 收集手术切除的33份突出颈椎间盘组织,以22份正常人颈椎间盘组织作为对照,组织形态学和TUNEL法检测凋亡细胞,免疫组织化学法检测增殖细胞核抗原(PCNA)、bax及Caspase-3的表达.结果 实验组的细胞密度低于对照组(髓核内:6.30±1.54比8.96±1.14;软骨终板内:17.27±1.82比25.41±1.89);实验组的TUNEL阳性细胞率高于对照组(髓核内:11.73±1.36比7.02±1.26;软骨终板内:13.04±1.75PC6.86±1.42);实验组髓核内PCNA阳性细胞率高于对照组(8.38±1.98比4.55±1.54);实验组髓核内bax阳性细胞率和Caspase-3阳性细胞率分别高于对照组(bax:19.32±1.95比10.94±1.72;Caspase-3:15.05±1.74比8.92±1.48);TUNEL阳性细胞率与细胞密度之间呈负相关(P＜0.01);实验组髓核内PCNA阳性细胞率与细胞密度之间呈正相关(P＜0.01);两组髓核内bax阳性细胞率、Caspase-3阳性细胞率均与TUNEL阳性细胞率之间呈正相关(P＜0.01).结论 细胞凋亡与细胞增殖间的不平衡可能是人退变颈椎间盘内细胞密度下降的原因,人颈椎间盘髓核细胞的过度凋亡可能与bax和Caspase-3的表达上调有关.     

腰椎间盘髓核组织中TrkB、NDRG2表达及其与衰老髓核细胞的关系

目的 探究退变腰椎间盘髓核组织中酪氨酸激酶受体B(tyrosine kinase receptor B,TrkB)、N-Myc下游调节基因2(N-myc downstream regulatory gene 2,NDRG2)表达变化,并分析两者与衰老髓核细胞之间的相关性.方法 选取2018年1月～2020年4月于本院行腰椎手术摘除的髓核组织标本75份,依据髓核退变程度Pfirrmann分级,划分为Ⅱ级组、Ⅲ级组、Ⅳ级组,各25例.采用细胞衰老β-半乳糖苷酶(senescence-associatedβ-galactosidase,SA-β-gal)试验检测髓核组织中衰老髓核细胞占比,采用RT-PCR技术检测微小RNA-200c(microRNA-200c,miR-200c)、TrkB mRNA及NDRG2 mRNA、P53 mRNA相对表达量,采用Western blotting法测定TrkB、NDRG2蛋白表达,并采用Pearson相关性分析TrkB、NDRG2表达与衰老髓核细胞的关系.结果 三组髓核组织中的衰老髓核细胞百分比比较,存在显著差异(F=145.315,P<0.001).三组miR-200c、TrkB mRNA、TrkB蛋白相对表达量比较,存在显著差异(P<0.05).三组P53 mRNA、NDRG2 mRNA与NDRG2蛋白相对表达量比较,Ⅱ级组<Ⅲ级组<Ⅳ级组,差异均有统计学意义(P<0.05).Pearson相关性分析显示,髓核组织中髓核细胞占比与TrkB mRNA相对表达量、TrkB蛋白相对表达量呈显著负相关(P<0.05),与NDRG2 mRNA相对表达量、NDRG2蛋白相对表达量呈显著正相关(P<0.05);miR-200c与TrkB mRNA呈显著负相关(r=-0.792,P<0.05),P53 mRNA与NDRG2 mRNA呈显著正相关(r=0.974,P<0.05).结论 TrkB、NDRG2可参与腰椎间盘退变病理过程,或经介导腰椎间盘髓核细胞衰老,促使椎间盘退变.     

前路减压治疗下颈椎颈髓损伤并截瘫

目的探讨下颈椎颈髓损伤手术及疗效以及影响疗效的因素。方法采用颈椎前路减压自体腓骨植骨融合治疗下颈惟颈髓损伤高位截瘫36例。结果18例随访2～8年．平均5年7个月按ASIA损伤分级，Ⅰ级14例，术后无效1例，术后恢复至Ⅱ级4例．Ⅲ级3例，Ⅳ级4例．Ⅴ级2例；Ⅱ级4例，术后恢复至Ⅲ级Ⅰ例，Ⅳ级2例．Ⅴ级1例；Ⅲ级6例．术后恢复至Ⅳ级3例．Ⅴ级3例；Ⅳ级4例．术后全部恢复至Ⅴ级。提示伤后8h内手术最佳时机。结论采用颈椎前路减压植骨融合治疗下颈惟颈髓损伤效果肯定。     

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.     

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.     

Intravenous endotoxin does not increase tissue extravasation of albumin in rats

Background : It is unclear whether activation of the inducible nitric oxide synthase (iNOS) increases or decreases the extravasation of plasma.
Methods : Chloralose anaesthetised male Wistar rats received E. coli lipopolysacharide (LPS), 3 mg kg^-1 i.v., or the corresponding volume of saline, 3 or 5 h before the end of the experiment. Mean arterial pressure (MAP) and heart rate (HR) were recorded. Tissue clearance of radio-labelled albumin, during the last 2 h of each experiment, was determined by a double-isotope method. In separate animals, the serum concentration of nitrite and nitrate was determined, 5 h after LPS or the solvent.
Main Results : LPS initially decreased MAP and lastingly increased HR. In the 3-h LPS animals (n=8), tissue plasma clearance was lower in the heart and calf muscle and increased only in diaphragm, compared to corresponding control animals (n=8). In the 5-h LPS rats, clearance was lowered (n=8) in the entire gastrointestinal tract and in testes, compared to controls (n=8). The serum nitrite/nitrate concentration was higher in animals given LPS (n=6) than in controls (n=6).
Conclusion : After LPS, tissue clearance of albumin was not increased in any major tissue, in spite of increased serum levels of NO end products. Apparently, after activation of iNOS, the augmented release of NO is not necessarily associated with increased albumin extravasation.     

Adrenaline markedly improves thoracic epidural analgesia produced by a low-dose infusion of bupivacaine, fentanyl and adrenaline after major surgery: A randomised, double-blind, cross-over study with and without adrenaline

Background: Basic pharmacological research indicates that there are synergistic antinociceptive effects at the spinal cord level between adrenaline, fentanyl and bupivacaine. Our clinical experience with such a mixture in a thoracic epidural infusion after major surgery confirms this. The objectives of the present study were to evaluate the effects on postoperative pain intensity, pain relief and side effects when removing adrenaline from this triple epidural mixture. Methods: A prospective, randomised, double-blind, cross-over study was carried out in 24 patients after major thoracic or abdominal surgery. Patients with only mild pain when coughing during a titrated thoracic epidural infusion of about 10 ml · h^?1 of bupivacaine 1 mg · ml^?1, fentanyl 2 μg · ml^?1, and adrenaline 2 μg · ml^?1 were included. On the 1^st and 2^nd postoperative days each patient was given a double-blind epidural infusion, at the same rate, with or without adrenaline. The effect was observed for 4 h or until pain when coughing became unacceptable in spite of a rescue analgesic procedure. Rescue analgesia consisted of up to two epidural bolus injections per hour and i.v. morphine if necessary. All patients received rectal paracetamol 1 g, every 8 h. Fentanyl serum concentrations were measured with a radioimmunoassay technique at the start and end of each study period. Main outcome measures were extent of sensory blockade and pain intensity at rest and when coughing, evaluated by a visual analogue scale, a verbal categorical rating scale, the Prince Henry Hospital pain score, and an overall quality of pain relief score. Results: The number of hypaesthetic dermatomal segments decreased (P <0.001) and pain intensity at rest and when coughing increased (P <0.001) when adrenaline was omitted from the triple epidural mixture. This change started within the first hour after removing adrenaline. After 3 h pain intensity when coughing had increased to unacceptable levels in spite of rescue analgesia (epidural bolus injections and i.v. morphine). Within 15–20 min after restarting the triple epidural mixture with adrenaline, pain intensity was again reduced to mild pain when coughing. Serum concentration of fentanyl doubled from 0.22 to 0.45 ng · ml^?1 (P <0.01), and there was more sedation during the period without adrenaline. Conclusions: Adrenaline increases sensory block and improves the pain-relieving effect of a mixture of bupivacaine and fentanyl infused epidurally at a thoracic level after major thoracic or abdominal surgery. Serum fentanyl concentrations doubled and sedation increased when adrenaline was removed from the epidural infusion, indicating more rapid vascular absorption and systemic effects of fentanyl.     

Utilisation des médicaments prokinétiques en réanimation : indications et limites ?

Enteral feeding is often limited by gastric and intestinal motility disturbances in critically ill patients, particularly in patients with shock. So, promotility agents are frequently used to improve tolerance to enteral nutrition. This review summaries the pathophysiology, presents the available pharmacological strategies, the clinical data, the counter-indications and the principal limits. The clinical data are poor. No study demonstrates a positive effect on clinical outcomes. Metoclopramide and erythromycin seems to be the more effective. Considering the risk of antibiotic resistance, the first line use of erythromycin should be avoided in favor of metoclopramide.     

Anesthésie générale chez l’enfant : quid des pratiques en 2010 ?

Introduction

The practice of pediatric anesthesia requires a regular update of scientific knowledge and technical skills. To provide the most adequate Continuing Medical Education programs, it is necessary to assess the practices of pediatric anesthesiologists. Thus, the objective of this survey was to draw a picture of the current clinical practices of general anesthesia in children, in France.

Material and methods

One thousand one hundred and fifty questionnaires were given to anesthesiologists involved in pediatric cases. These questionnaires collected information on various aspects of clinical practice relative to induction, maintenance, recovery from general anaesthesia and also classical debated points such as children with Upper Respiratory Infection (URI), emergence agitation, epileptoid signs or anaesthetic management of adenoidectomy. Differences in practices between CHG (general hospital), CHU (teaching hospital), LIBERAL (private) and PSPH (semi-private) hospitals were investigated.

Results

There were 1025 questionnaires completed. Fifty-five percent of responders worked in public hospitals (CHG and CHU); 77% had a practice that was 25% or less of pediatric cases. In children from 3 to 10 years: 72% of respondents used always premedication and two thirds performed inhalation induction in more than 50% of cases. For induction, 53% used sevoflurane (SEVO) at 7 or 8%. Respondents from LIBERAL used higher SEVO concentrations. Tracheal intubation was performed with SEVO alone (37%), SEVO and propofol (55%) and SEVO with myorelaxant (8%), 93% of respondents used a bolus of opioid. For maintenance, the majority of respondents used SEVO associated with sufentanil; desflurane and remifentanil were more frequently used in CHU. Two thirds of respondents used N₂O. Depth of anesthesia was commonly assessed by hemodynamic changes (52%), end tidal concentration of halogenated (38%) or automated devices based on EEG (7%). In children with URI, 98% of respondents used SEVO for anesthesia. To control the airway 42% used a tracheal tube, 30% a laryngeal mask and 20% a facial mask. Emergence agitation was an important concern for two thirds of respondents, while epileptoid signs were considered as important by only 20%. Eighty-nine percent of respondents practiced anesthesia for adenoidectomy. Anesthesia was induced by inhalation of SEVO 7–8% (41%), 6% (39%) or 4% (12%), 66% put an intravenous line (less frequently in LIBERAL). 67% of the responders managed adenoidectomy without any device to control the airway (more frequently in LIBERAL), 32% administrated a bolus of opioid (less frequently in LIBERAL).

Discussion

This survey demonstrated that the practices regarding general anesthesia in children are relatively homogenous. Most of the differences appeared between LIBERAL and the others structures; the anaesthetic management for adenoidectomy illustrates these findings.     

Intérêt d’une rééducation précoce pour les patients neurologiques

Rehabilitation improves the functional prognosis of patients after a neurologic lesion, and tendency is to begin rehabilitation as soon as possible. This review focuses on the interest and the feasibility of very early rehabilitation, initiated from critical care units. It is necessary to precisely assess patients’ impairments and disabilities in order to define rehabilitation objectives. Valid and simple tools must support this evaluation. Rehabilitation will be directed to preventing decubitus complications and active rehabilitation. The sooner rehabilitation is started; the better functional prognosis seems to be.     

Risiko Schlaganfall — Öffentlichkeitsarbeit und Aufklärung dringend erforderlich

Zusammenfassung Das wesentliche — und zugleich noch wenig ausgeschöpfte — Potenzial der Schlaganfallmedizin liegt in der langfristigen Prophylaxe. Durch Beeinflussung von Lifestylefaktoren wie Ernährungsgewohnheiten, Zigarettenkonsum und körperlichem Training durch entsprechende Aufklärung ließe sich ein erheblicher Teil an zerebralen Ereignissen vermeiden. Ein weiterer in Deutschland noch zu wenig beachteter Faktor ist die konsequente Blutdruckeinstellung. Breitgestreute Aufklärung könnte außerdem potenziellen Patienten helfen, bereits auftretende Warnsymptome wie die transiente ischämische Attacke richtig einzuschätzen, um eine rechtzeitige Behandlung zu ermöglichen.