富马酸二甲酯对小鼠肾缺血再灌注损伤的保护作用及其机制

目的探讨富马酸二甲酯(DMF)在小鼠肾脏缺血再灌注损伤中的保护作用及可能的机制。方法将小鼠随机分成3组(n=8):假手术组(S组)、缺血再灌注组(IR组)和DMF预处理组(DMF组)。IR组及DMF组制备肾脏IR模型,再灌注24h后收集血清及肾组织,测定血清肌酐(SCr)及尿素氮(BUN)值;评定肾脏组织形态学改变;检测肾脏组织中丙二醛(MDA)含量及超氧化物歧化酶(SOD)活力;Western-blot检测各组肾组织内核因子E2相关因子2(Nrf2)及血红素氧化酶-1(HO-1)蛋白含量。结果IR组SCr及BUN显著高于S组[(143.17±14.18)μmol/L,(26.52±3.56)mmol/L vs.(24.50±5.54)μmol/L,(8.25±2.14)mmol/L,P0.01];DMF组SCr及BUN均低于IR组[(81.83±9.39)μmol/L,(18.62±2.75)mmol/L vs.(143.17±14.18)μmol/L,(26.52±3.56)mmol/L](P0.01);和IR组比较,DMF组的组织形态学损伤较轻(P0.01);DMF组过氧化损伤指标MDA水平低于IR组[(3.55±0.48)μmol/g vs.(5.48±0.70)μmol/g](P0.01),而抗氧化酶SOD水平高于IR组[(35.02±4.13)kU/g vs.(23.80±4.36)kU/g](P0.01)。Western-blot及免疫组化结果显示DMF组Nrf2和HO-1蛋白表达水平高于IR组(P0.05)。结论 DMF对小鼠肾缺血再灌注损伤具有保护作用,其机制可能与激活Nrf2/HO-1通路进而提高肾脏抗氧化应激能力有关。     

L-精氨酸和氨基胍在大鼠肺移植缺血再灌注损伤中的作用

目的 观察L-精氨酸(L-Arg)和氨基胍对大鼠肺移植后缺血再灌注的保护作用.方法 建立大鼠左单肺移植模型,术后随机分为A组(对照组,腹腔注射生理盐水),B组(腹腔注射L-Arg)、C组(腹腔注射氨基胍)和D组(腹腔注射L-Arg和氨基胍),每组6只.移植肺再灌注2 h后,检测肺组织髓过氧化物酶(MPO)、丙二醛(MDA)含量、超氧化物歧化酶(SOD)活力、内皮型一氧化氮合酶(eNOS)和诱导型一氧化氮合酶(iNOS)活性并测定移植肺干湿重比(W/D)及静脉血中一氧化氮(NO)含量,观察移植肺的病理学形态.结果 再灌注2 h后,B组移植肺的W/D(5.10±0.21)、MPO(1.74±0.26)U/g和MDA(20.87±2.90)μmol/g均低于A组W/D(5.74 ±0.14)、MPO(2.36±0.32)U/g和MDA(31.33 ±3.46)μmol/g;SOD活性(424.29±27.86)U/mgprot、NO含量(175.12 ±17.40)μmol/L、iNOS活性(3.62 ±0.26)U/mgprot和eNOS活性(5.36±0.28)U/mgprot均较A组SOD活性(268.01±26.06)U/mgpro、NO含量(98.29±6.95)μmol/L、iNOS活性(2.53 ±0.22)U/mgprot和eNOS活性(3.57 ±0.40)U/mgprot高(P＜0.05).C组的NO含量(84.13±5.18)μmol/L、iNOS活性(1.81 ±0.09)U/mgprot均较A组低(P＜0.05).D组的W/D(4.79 ±0.19)、MPO(1.24±0.13)U/g、MDA(14.60±4.14)μmol/g、iNOS活性(1.99±0.17)U/mgprot低于A组,SOD活性(493.75±24.95)、NO含量(149.61±10.70)μmol/L、eNOS活性(5.50±0.27)U/mgprot高于A组(P＜0.05).与B组比较,D组的W/D、MPO、MDA、NO含量、iNOS活性降低,SOD升高(P＜0.05).病理形态学检查显示D组炎细胞浸润及渗出最轻,B组次之,A组和C组最差.结论 移植后再灌注早期应用L-Arg可减轻缺血再灌注损伤,应用氨基胍并不能减轻移植肺的损伤,但联合应用L-Arg和氨基胍优于单纯应用L-Arg.

Abstract：

Objective To investigate the effects of L-arginine (L-Arg) and aminoguanidine on ischemia-reperfusion injury following rat lung transplantation. Methods The models of rats lung transplantation were established and 4 groups ( n = 6 each) were randomly set up: group A ( normal control group)and treated groups B, C and D. In these groups, different medicines (NS, group A; L-Arg, group B;aminoguanidine, group C; L-Arg and aminoguanidine, group D) were intraperitoneally administered to the recipient rats before reperfusion. After reperfusion for 2 h, the lung graft was harvested for measurements of lung wet/dry ratio ( W/D ) , myeloperoxidase ( MPO ) , malondialdehyde ( MDA ) , superoxide dismutase (SOD) , endothelial nitric oxide synthase (eNOS) , inducible nitric oxide synthase (iNOS). The contents of plasma nitric oxide (NO) were determined. The pathological changes in the lung grafts were observed.Results After reperfusion for 2 h, W/D (5. 10 ±0.21), MPO (1.74 ±0.26) U/g, MDA (20.87 ±2. 90) μmol/g in group B were significantly lower [W/D (5. 74 ± 0. 14), MPO (2. 36 ± 0. 32) U/g,MDA (31. 33 ±3.46) μmol/g] (P ＜ 0. 05), and the levels of SOD (424. 29 ± 27. 86) U/mg protein,NO (175. 12 ± 17. 40) μmol/L, iNOS (3. 62 ±0. 26) U/mg protein and eNOS (5. 36 ±0. 28) U/mg protein were significantly higher than in group A [SOD (268.01 ±26.06) U/mg protein, NO (98.29 ±6.95) μmol/L, iNOS (2.53 ±0.22) U/mg protein and eNOS (3. 57 ±0.40) U/mg protein] (P＜0. 05). The contents of NO (84. 13 ±5. 18) μmol/L and iNOS (1. 81 ±0. 09) U/mg protein in group C were significantly lower than in group A (P ＜ 0. 05). W/D (4. 79 ± 0. 19) , MPO (1. 24 ± 0. 13 ) U/g,MDA (14. 60 ±4. 14) μmol/g, iNOS (1. 99 ±0. 17) U/mg protein were significantly lower than in group A (P ＜0. 05) , and SOD (493. 75 ±24. 95) , NO (149. 61 ± 10. 70) μmol/L and eNOS (5. 50 ±0. 27)U/mg protein in group D were significantly higher than in group A (P＜0. 05). W/D, MPO, MDA, NO and iNOS in group D were significantly reduced as compared with group B (P ＜ 0. 05 ) , and SOD was significantly increased in group B ( P ＜ 0. 05 ) . The pathological examination revealed that the inflammatory cell infiltration in group D was the mildest, followed by groups B, A and C. Conclusion The L-Arg could alleviate the lung ischemia-reperfusion injury after transplantation, the combined used of L-Arg and aminoguanidine could obtain better effects than L-Arg used alone. The aminoguanidine used alone could not alleviate ischemia-reperfusion injury after transplantation.     

黄芪对梗阻性黄疸肝缺血再灌注大鼠肾损伤的影响

目的:探讨黄芪对梗阻性黄疸术后肝缺血再灌注肾脏功能损伤的影响。方法:选取60只大鼠,分为梗阻性黄疸组(A组)、梗阻性黄疸肝脏缺血再灌注组(B组)、梗阻性黄疸肝脏缺血再灌注+黄芪注射液组(C组)3组,每组20只,组内依据灌注时间点0、1、3、6、12 h分为5个亚组,每组4只。按时间点检测血清中尿素氮(BUN)、肌酐(Cr)、肿瘤坏死因子-α(TNF-α)的水平及肾脏组织中丙二醛(MDA)、超氧化物歧化酶(SOD)、髓过氧化物酶(MPO)含量。结果:与A组相同时间点比,其余两组BUN、Cr和TNF-α水平升高(P0.05);MDA、MPO含量升高,SOD含量减少(P0.05);C组血清和肾脏组织中各项指标的改变程度均明显低于B组(P0.05)。结论:黄芪能够保护梗阻性黄疸术后肝脏缺血再灌注引起的远端肾脏功能损伤,其与提高机体抗氧化能力,减少中性粒细胞聚集率、降低脂质过氧化及炎症反应相关。     

肾缺血后处理对热休克蛋白表达的影响及作用

目的 评价肾缺血后处理(ischemic postconditioning,IPo)对热休克蛋白(heat shock protein,HSP)70、HSP27和血红素加氧酶-1(heme oxygenase-1,HO-1,即HSP32)表达的影响及在减轻肾缺血/再灌注损伤(ischemia/reperfusion injury,I/RI)中的作用.方法 健康雄性SD大鼠140只,体重250 g～280 g,采用随机数字表法随机分为4组(每组35只):假手术组(S组)仅开腹,游离双侧肾脏,分离双侧肾蒂不夹闭;缺血/再灌注(ischemia/reperfusion,I/R)组,夹闭双侧肾蒂缺血45 min,恢复灌注;IPo组,夹闭双侧肾蒂45 min,再灌注10 s,缺血10s,反复3次,恢复灌注;HSP抑制剂槲皮黄酮+IPo组(Q+IPo组),缺血前lh腹腔注射槲皮黄酮100 mg/kg,余操作同IPo组.于再灌注即刻(T0)、1、3、6、12、24、48 h(T1～6)时取5只大鼠经心脏抽血后迅速处死取肾,采用逆转录-多聚酶链反应(RT-PCR)和免疫组织化学法分别检测各时点肾组织HSP70、HSP27和HO-1的mRNA和蛋白表达,测定T3时血清肌酐(creatinine,Cr)和尿素氮(urea nitrogen,BUN)浓度、肾组织丙二醛(methylene dioxyamphetamine,MDA)含量和超氧化物歧化酶(superoxide dismutase,SOD)活性、肾组织核因子-κB(nuclear factor-kappa B,NF-κB)表达和血清肿瘤坏死因子-α(tumor necrosis factorα,TNF-α)浓度,光镜下观察肾组织病理学结果. 结果 S组HSP70、HSP27和HO-1的mRNA有微量表达,蛋白几乎无表达,其余组在To时开始表达,逐渐升高,T3时达高峰,随后逐渐下降.与S组比较,其余组各时点HSP70、HSP27和HO-1的mRNA和蛋白表达上调(P＜0.05),IPo组较I/R组T2～5时HSP70、HSP27和HO-1的mRNA和蛋白表达上调(P＜0.05),Q+IPo组较IPo组T2～5时HSP70、HSP27和HO-1的mRNA和蛋白表达下调(P＜0.05).T3时血清Cr、BUN和TNF-α浓度I/R组分别为(102±5) μmol/L、(25.7±3.9) mmol/L、(2.29±0.18) μg/L,IPo组分别为(64±5)μmol/L、(11.3±3.0) mmol/L、(1.76±0.13)μg/L,Q+IPo组分别为(101±6)μmol/L、(26.5±4.5) mmol/L、(2.31±0.17) μg/L,均高于S组(46±6) μmol/L、(5.1±1.9) mmol/L和(1.13±0.14) μg/L(P＜0.05),IPo组三者浓度较I/R组降低(P＜0.05),Q+IPo组较IPo组升高(P＜0.05).T3时MDA含量I/R组(2.20±0.23) nmol/mgprot、IPo组(1.35±0.13) nmol/mgprot和Q+IPo组(2.25±0.16) nmol/mgprot较S组(1.02±0.19) nmol/mgprot升高(P＜0.05),SOD活性I/R组(104±6) U/mgprot、IPo组(124±4) U/mgprot和Q+IPo组(106±5) U/mgprot较S组(147±6) U/mgprot 降低(P＜0.05),IPo组与I/R组比较MDA含量降低和SOD活性升高(P＜0.05),Q+Ipo组与IPo组比较MDA含量升高和SOD活性降低(P＜0.05),肾组织NF-κB表达I/R组、IPo组和Q+IPo组较S组增高,IPo组较I/R组表达降低,Q+IPo组较IPo组表达增高(P＜0.05).I/R组与Q+Ipo组相比,各指标差异无统计学意义(P＞0.05).与S组比较,其余3组有程度不等的肾组织病理学损伤,IPo组损伤较I/R组减轻,Q+IPo组损伤程度与I/R组相似. 结论 IPo上调了HSP70、HSP27和HO-1的表达;HSP高表达参与了肾IPo减轻肾I/RI的过程.     

大鼠肺缺血期肢体缺血处理对肺缺血/再灌注损伤的保护作用

目的 观察大鼠肺缺血期双后肢缺血处理对肺缺血/再灌注损伤的影响.方法 将24只SD大鼠随机分为3组(n=8):缺血再灌注组(I/R组)、肺缺血期肢体缺血处理组(LIPER组)和假手术组(S组).I/R组开胸后左侧肺门阻断45 min,再灌注120 min.LIPER组左侧肺门阻断45 min,再灌注120 min,左侧肺门阻断5 min时阻断双后肢血供5 min,再灌注5 min,反复4次处理.S组开胸后旷置观察165 min.再灌注120 min时采动脉血样作血气分析;再灌注120 min后处死大鼠,取左肺组织,测定超氧化物歧化酶(SOD)、髓过氧化物酶(MPO)活性及丙二醛(MDA)含量;计算湿干比(W/D);肺组织行病理切片,苏木素-伊红(HE)染色,观察病理形态改变,并进行肺损伤评分.结果 I/R组和LIPER组血氧分压(PaO2)值分别为(58.5±3.1)和(71.0±3.5)mmHg(1 mmHg =0.133 kPa,P＜0.05)、W/D值分别为6.20±0.32和5.39 ±0.29(P ＜0.05)、SOD活性分别为(14.21±1.14)和(33.78 ±2.06) U/mg(P＜0.05)、MDA含量分别为(1.32±0.09)和(0.81±0.05) nmol/mg(P＜0.05)、MPO活性分别为(4.30 ±0.22)和(2.01 ±0.17) U/g(P＜0.05)、急性肺损伤评分值分别为(12.13±1.13)和(6.75±0.71)分(P＜0.05).结论 肺缺血期双后肢缺血处理具有减轻肺缺血/再灌注损伤的作用.     

左卡尼汀对肾缺血再灌注损伤的抗氧化作用及其机制

目的研究左卡尼汀对大鼠肾缺血再灌注损伤的抗氧化作用并探讨其机制。方法将大鼠随机分为3组：对照组（C组）,缺血再灌注组（IR组）,左卡尼汀组（LC组）。C组不予缺血再灌注处理,IR组及LC组建立肾脏IR模型。再灌注6h后检测各组血清肌酐（Cr）和尿素氮（BUN）水平;测定肾组织超氧化物歧化酶（SOD）活性及丙二醛（MDA）含量;RT-PCR检测肾组织核因子E2相关因子2（Nrf2）、血红素氧化酶-1（HO-1）mRNA含量;Western-blot检测各组肾组织Nrf2及HO-1蛋白表达水平。结果 LC组血清Cr、BUN水平低于IR组[（74.17±12.80）μmol/L、（24.28±2.58）mmol/L vs.（112.83±17.45）μmol/L、（35.13±6.01）mmol/L],差异具有统计学意义（P〈0.01）。LC组肾组织SOD活性高于IR组[（39.55±6.61）kU/g vs.（28.05±4.37）kU/g],差异具有统计学意义（P〈0.01）;MDA显著降低于IR组[（4.15±0.69）μmol/g vs.（6.12±1.08）μmol/g],差异具有统计学意义（P〈0.01）。IR组Nrf2、HO-1mRNA及蛋白表达水平高于C组（P〈0.01）,低于LC组（P〈0.01）。结论左卡尼汀对肾脏缺血再灌注损伤具有明显保护作用,其机制可能为激活Keapl-Nrf2-ARE通路进而诱导HO-1的表达。     

缺血后处理对小鼠肠缺血再灌注致肾损伤时Nrf2蛋白表达的影响

目的 评价缺血后处理对小鼠肠缺血再灌注致肾损伤时核因子E2相关因子2(Nrf2)蛋白表达的影响.方法 健康雄性C57BL/6J小鼠36只,9～12周,采用随机数字表法,将其随机分为3组(n=12):假手术组(S组)、缺血再灌注组(I/R组)、缺血后处理+缺血再灌注组(IPO组).采用夹闭肠系膜上动脉根部45 min恢复灌注的方法制备小鼠肠缺血再灌注损伤模型,IPO组于缺血45 min时再灌注30s,缺血30s,重复3次后恢复灌注.于再灌注2h时采集颈动脉血样,然后处死小鼠,取肾组织,测定血清BUN、Cr和中性粒细胞明胶酶相关脂质运载蛋白(NGAL)水平,检测肾组织Nrf2和HO-1蛋白表达、MDA含量、SOD活性、TNF-α、IL-6和IL-10的含量.显微镜下观察肾组织病理学结果,并行病理学损伤评分.结果 与S组比较,I/R组血清BUN、Cr和NAGL浓度升高,肾脏组织Nrf2及HO-1蛋白表达上调,MDA含量升高,SOD活性降低,肾脏组织病理学损伤评分升高(P＜0.05);与I/R组比较,IPO组血清BUN、Cr和NAGL浓度降低,肾脏组织Nrf2及HO-1蛋白表达上调,MDA含量降低,SOD活性升高,肾脏组织病理学损伤评分降低(P＜0.05).各组肾脏组织TNF-α、IL-6和IL-10含量比较差异无统计学意义(P＞0.05).结论 缺血后处理可减轻小鼠肠缺血再灌注致肾损伤,其机制可能与促进Nrf2蛋白表达,从而上调HO-1蛋白表达有关.     

前列地尔对兔肾缺血再灌注时细胞凋亡的保护作用

目的 观察前列地尔对兔肾缺血再灌注损伤时肾小管上皮细胞凋亡的保护作用.方法 建立兔肾缺血再灌注损伤动物模型,将实验兔随机分为3组:即对照组、缺血再灌注组和前列地尔组,每组10只.检测兔血清肌苷(Cr)、尿素氮(BUN)浓度及肾组织中丙二醛(MDA)、超氧化物歧化酶(SOD)和髓过氧化物酶(MPO)含量及肾组织中凋亡细胞.结果 与对照组比较,缺血再灌注组和前列地尔组在再灌注后Cr、BUN水平均大幅度上升(P＜0.05);但前列地尔组动物在再灌注60min后Cr水平(231.32±17.57)μmol/L明显低于缺血再灌注组(390.61±20.42)μmol/L(P＜0.05);肾小管上皮细胞bcl-2、bax、Caspase-3表达与对照组比较,缺血再灌注组明显增强(P＜0.05);前列地尔组与缺血再灌注组比较表达减弱,但仍强于对照组(P＜0.05).前列地尔组、缺血再灌注组与对照组比较凋亡细胞数增多,前列地尔组与缺血再灌注组比较凋亡细胞数减少.MDA、SOD与MPO的活性与对照组比较,缺血再灌注组与前列地尔组明显增强(P＜0.05);前列地尔组与缺血再灌注组比较,该两者活性明显减弱(P＜0.05).结论 前列地尔在肾脏缺血再灌注损伤时能有效的保护肾功能其作用机制可能是通过减少细胞脂质过氧化,从而降低bcl-2、bax、Caspase-3等凋亡基因的表达.

Abstract：

Objective To study the alprostadil effects of alprostadil on apoptosis by renal ischemia-reperfusion injury (IR[) in rabbits. Methods The rabbit IRI models were made, and randourly divided into three groups: control group, IR[group and prostavasin intervention group. The creatinine (Ct) and blood urea nitrogen (BUN) were determined. Malondialdehyde ( MDA), superoxide dismutase (SOD),myeloperoxidase ( MPO), bcl-2, bax, Caspase-3 and apoptosis were assayed at 60 min after reperfusion.Results The Cr and BUN levels in plasma in IRI group and Prostavasin intervention group were increased obviously after reperfusion. The Cr levels at 60 min after repeffusion in alprostadil intervention group (231.32 + 17. 57 ) μmol/L were significantly lower than in IRI group ( 390. 61 ± 20. 42 ) μ mol/L, ( P ＜0. 05 ). The levels of bcl-2, bax, Caspase-3 in the renal tissue in IRI group were significantly higher than in control group ( P ＜ 0. 05 ), and those in alprostadil intervention group were lower than in IRI group, but markedly higher than in control group (P ＜ 0. 05 ). The number of apoptotic cells in alprostadil intervention group and IRI group was increased as compared with control group, and that in alprostadil intervention group was reduced as compared with IRI group. The contents of MDA, SOD and MPO in renal tissue of IRI group and Prostavasin intervention group were significantly higher than in control group ( P ＜ 0. 05 ), and those in IRI group were significantly lower than in alprostadil intervention group (P ＜0. 05 ). Conclusion Alprostadil could be used to protect renal ischemia-reperfusion injury probably by decreasing oxygen free radicals generation, inhibiting neutrophils aggregating and activating in the renal tissues, thereby inhibiting the expression of bcl-2, bax, Caspase-3.     

肾脏远隔缺血后适应在兔急性肠系膜缺血再灌注损伤中的作用

目的 观察以肾脏作为远隔器官的远隔缺血后适应能否减轻兔急性肠系膜缺血再灌注损伤.方法 将雄性新西兰兔90只随机分为对照组、缺血再灌注(I/R)组、远隔缺血后适应(IRpostC)组,每组30只.分别干预后采集各组兔部分肠道组织作为标本,试剂盒检测肠道组织内丙二醛(MDA)、髓过氧化物酶(MPO)水平,苏木素-伊红(HE)染色,chiu6级评分法观察肠黏膜损伤,电镜下观察肠上皮细胞变化.结果 I/R组肠道组织中MDA、MPO测定值及肠黏膜损伤评分分别为( 14.72±0.21) nmol/mg、( 1.65±0.35) U/g、(3.30±0.69),IRpostC组分别为(7.13 ±0.40) nmol/mg、(0.91±0.33) U/g、2.10 ±0.92,与对照组[(3.28±0.26) nmol/mg、(0.52 ±0.23) U/g、0.69±0.52]比较差异均有统计学意义(P＜0.01).与I/R组比较,IRpostC组肠道组织中MDA、MPO水平及肠黏膜损伤评分明显降低(P＜0.01),电镜下发现细胞损伤减轻.结论 以肾脏作为远隔器官的远隔缺血后适应可明显降低兔急性肠系膜缺血再灌注损伤后肠道组织中MDA、MPO水平及肠黏膜损伤.     

肢体缺血预处理对兔肺缺血再灌注损伤的影响

目的 探讨肢体缺血预处理对兔肺缺血再灌注损伤的影响.方法 健康日本大耳白兔18只,体重2.0～2.5 kg,雌雄不拘,随机分为3组(n=6):假手术组(S组)开胸后左侧肺门穿线但不结扎,旷置观察340 min;缺血再灌注组(IR组)开胸旷置100 min,阻断左侧肺门,左肺不张后60 min再灌注180 min;肢体缺血预处理组(L组)捆绑双后肢10 min,松开10 min,反复3次后恢复灌注,60 min后阻断左侧肺门60 min,再灌注180 min.于缺血前、再灌注15、30、60、120、180 min时采集左颈内动脉血样行血气分析,计算呼吸指数(R1);于再灌注180 min时处死动物,取左肺上叶组织,测定超氧化物歧化酶(SOD)、髓过氧化物酶(MPO)活性及丙二醛(MDA)含量,计算肺湿干重比(W/D);取左肺下叶行支气管肺泡灌洗,计算肺通透性指数;取左肺中叶组织,观察肺组织病理学,进行弥漫性肺泡损伤(DAD)评分.结果 与s组比较,IR组RI、MDA含量、MPO活性、肺W/D、肺通透性指数和DAD评分升高,SOD活性降低(P<0.05或0.01);与IR组比较,L组RI,MDA含量、MPO活性、肺W/D、肺通透性指数和DAD评分降低,SOD活性升高(P<0.05或0.01);L组和S组间上述指标比较差异无统计学意义(P>0.05).L组和S组肺组织病理损伤程度较IR组减轻.结论 肢体缺血预处理可减轻兔肺缺血再灌注损伤.     

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.