慢病毒载体GV115介导Caspase-3 siRNA转染人椎间盘髓核细胞的生物学效应

目的 :研究慢病毒载体GV115介导Caspase-3 si RNA转染人椎间盘髓核细胞的生物学效应。方法 :采集12例外伤致脊柱爆裂性骨折患者(22~36岁)术中切除的椎间盘髓核组织,采用组织块法分离培养髓核细胞并传代。取第2代髓核细胞,分为GV115-Caspase3 si RNA组、GV115组和对照组,各组12个细胞培养孔。在荧光显微镜下观察计数阳性髓核细胞,计算GV115-Caspase3 siRNA对人椎间盘髓核细胞的转染效率;采用免疫荧光法检测三组髓核细胞中Caspase-3表达;采用MTT法检测三组髓核细胞活性;采用Western-Blot法和Antonopulos法分别检测三组髓核细胞的Ⅱ型胶原和蛋白多糖含量。结果 :椎间盘髓核细胞被成功分离培养,培养1周后细胞达到80%融合,进行传代培养。转染后1周(85.6±1.3)%的髓核细胞可被GV115-Caspase3 si RNA转染而表达绿色荧光素。GV115-Caspase3 siRNA组Caspase-3免疫荧光阳性细胞率[(19.4±3.2)%]较GV115组[(84.3±9.2)%]和对照组[(83.9±8.7)%]明显减少(P0.05),OD值(1.56±0.21)较GV115组(0.91±0.15)和对照组(0.92±0.17)高(P0.05),Ⅱ型胶原免疫印迹染色强度(1.32±0.09)较GV115组(0.81±0.05)和对照组(0.79±0.04)高(P0.05),蛋白多糖含量(0.56±0.09)较GV115组(0.35±0.06)和对照组(0.34±0.05)高(P0.05)。结论:GV115-Caspase3 siRNA可高效转染人椎间盘髓核细胞,增强髓核细胞的生物活性,并促进细胞外基质的合成。     

洛伐他汀对胆管癌细胞株QBC939生长侵袭的抑制作用

目的 研究洛伐他汀(lovastatin)对人胆管癌细胞株QBC939生长、迁移、凋亡等生物学行为的影响,初步探讨其可能机制.方法 应用四甲基偶氮唑盐法检测洛伐他汀作用后细胞增殖情况.流式细胞技术检测细胞凋亡率.细胞划痕实验观察细胞迁移能力改变.RT-PCR和Western印迹法检测洛伐他汀作用前后人胆管癌细胞株QBC939中白细胞介素-6(IL-6)、丝氨酸/苏氨酸蛋白激酶B(protein kinase B,PKB/Akt)、血管内皮生长因子(VEGF)、基质金属蛋白酶—9(MMP-9) mRAN 和Akt蛋白的表达.结果 与对照组相比,洛伐他汀组胆管癌细胞相对活力明显降低(24 h、48 h、72 h:F=173.05、159.66、577.87,均为P＜0.01)并具有浓度时间依赖性.洛伐他汀组较对照组细胞早期凋亡[(14.29±0.75)％比(5.61±0.85)％]、总凋亡[(35.48±1.13)％比(24.94±0.40)％]比例明显增加(均为P＜0.01).细胞24 h、48 h平均迁移速率明显减慢(分别为10.94±3.07比24.17±3.31和10.96±2.45比18.65±0.94,均为P＜0.01).洛伐他汀组中IL-6、Akt、VEGF、MMP-9 mRNA和Akt蛋白的表达明显低于对照组(均为P＜0.05).结论 洛伐他汀可抑制胆管癌细胞的增殖、迁移并诱导其凋亡,可能与下调IL-6、Akt、VEGF、MMP-9的表达有关.     

辅助性T细胞亚群分化在Ⅲ型前列腺炎免疫发病机制中的作用

目的 探讨前列腺液(EPS)中CD+4T细胞亚群辅助性T细胞(Th细胞)分化在Ⅲ型前列腺炎免疫发病机制中的作用. 方法门诊诊断前列腺炎患者76例,年龄18～47岁,平均32岁.患者均有慢性前列腺炎典型临床症状,病程均＞3个月.按美国国立卫生院分类方法分为ⅢA型组(47例)、ⅢB型组(29例).其中ⅢA型组根据炎症程度又分为ⅢAl组(轻度炎症26例)和ⅢA2组(重度炎症21例).另设健康对照组(16例),年龄19～45岁,平均31岁.采用双抗体夹心酶联免疫法检测EPS中Th1类细胞因子(IFN-γ)、Th2类细胞因子(IL-4)水平及Th1/Th2比值(IFN-γ/IL-4),比较各组问差异.结果 ⅢA、ⅢB组IFN-γ水平[(134.78±43.67),(109.82±30.09)pg/m1]与对照组[(60.63±15.16)pg/m1]比较,差异有统计学意义(P＜0.05),ⅢA组较ⅢB组升高更明显(P＜0.05);ⅢA组IL-4水平[(51.99±20.59)pg/m1]与对照组[(53.88±17.92)pg/m1]比较差异无统计学意义P＞0.05),ⅢB组IL-4水平[(76.40±17.99)pg/m1]明显上调(P＜0.05);ⅢA组IFN-γ/IL-4水平(2.94±1.12)明显高于对照组(1.20±0.48,P＜0.05),Ⅲ B组(1.49±0.48)无明显改变(P＞0.05).与对照组比较,Ⅲ A1组IL-4水平[(63.03±18.86)pg/m1]无明显变化(P＞0.05),而ⅢA2组水平[(30.20±13.16)pg/m1]显著下调(P＜0.05);ⅢA1组和m A2组IFN-γ水平均明显上调[(127.65±36.57),(143.49±50.76)pg/m1],P＜0.05),但2组间差异无统计学意义(P＞0.05);ⅢA2组IFN-γ/IL-4明显高于ⅢA1组(3.67±0.82 vs 2.34±0.97,P＜0.05).结论 ⅢA型前列腺炎Th1细胞分化占优势,Th1/Th2平衡向Th1漂移,以细胞免疫反应为主;Th细胞分化也参与了ⅢB型前列腺炎的发病,但Th1/Th2处于相对平衡状态.Th1的优势分化可能是导致前列腺局部炎症发展的原因之一.     

吉西他滨化疗对免疫健全小鼠Panc02胰腺癌的作用以及对免疫环境的影响

目的 建立免疫健全小鼠Panc02胰腺癌皮下种植瘤模型.利用该模型观察吉西他滨化疗对免疫健全小鼠胰腺癌的作用以及对全身及肿瘤局部免疫环境的影响.方法 利用C57BL/6J小鼠同源Panc02胰腺癌细胞建立皮下种植瘤模型.待肿瘤生长至75 ～ 100 mm3时,将荷瘤小鼠分为化疗组和对照组.化疗组利用吉西他滨50 mg/kg腹腔内注射化疗,每周2次,共4周.绘制肿瘤生长曲线,最终称量荷瘤小鼠体质量、肿瘤重量及脾脏重量.流式细胞计数检测外周血与肿瘤组织中10个免疫细胞群的变化.实时荧光定量反转录-聚合酶链反应检测荷瘤小鼠脾脏及肿瘤组织中7种细胞因子水平.免疫组织化学法及Western blot检测CD34及淋巴管内皮透明质酸受体-1(LYVE-1)蛋白表达,并计数肿瘤组织中微血管密度(MVD)及淋巴管密度(LVD).结果 化疗组肿瘤体积明显小于对照组,在各个时间点比较差异有统计学意义(P＜0.05).化疗组荷瘤小鼠体质量明显小于对照组[(21.00±1.88)g比(28.36±1.06)g,P＜0.01].化疗组终末肿瘤重量明显小于对照组[(641.67 ±289.92) mg比(1 492.00±462.73)mg,P＜0.01].化疗组与对照组脾脏重量比较差异无统计学意义(P＞0.05).化疗后外周血中CD11c+树突状细胞增多[(22.93±2.26)％比(16.53±2.68)％,P＜0.05],CD11b+ Gr-1+髓系来源抑制细胞(MDSC)减少[(3.00±0.10)％比(7.03±0.32)％,P＜0.01].化疗后肿瘤组织中CD3+T淋巴细胞[(10.70±1.21)％比(21.10±3.54)％,P＜0.01]及MDSC[(5.10 ±2.11)％比(10.50±0.72)％,P＜0.05]减少,而树突状细胞[(17.13±3.21)％比(10.43±1.60)％,P＜0.05]、CD19+B细胞[(17.13±2.68)％比(7.90±1.87)％,P＜0.01]、Gr-1+粒细胞[(79.50 ±5.86)％比(46.00±3.75)％,P＜0.01]、CD3+NK1.1+自然杀伤T细胞(NKT)[(9.77±1.56)％比(4.90±1.81)％,P＜0.05]增多.化疗后脾脏中白细胞介素-4 (IL-4)表达升高(P＜0.05),而肿瘤坏死因子-α(TNF-α,P＜0.05)及IL-2(P＜0.01)表达下降.化疗后肿瘤组织中IL-4及转化生长因子(TGF)-β表达升高(P＜0.05),而IL-6、干扰素(IFN)-γ、TNF-α及IL-2表达均下降(P＜0.05或P＜0.01).化疗后肿瘤组织中MDSC效应产物精氨酸酶-1(Arginase-1)明显下降(P＜0.05).化疗后肿瘤组织中MVD(18.47±2.61比30.40±3.92,P ＜0.05)及LVD(6.66±2.77比16.27±2.02,P＜0.01)均下降.结论 吉西他滨可以抑制小鼠Panc02胰腺癌生长以及肿瘤组织中淋巴管及血管的生成,但也诱导产生了肿瘤局部和全身的免疫抑制效应,以肿瘤局部免疫抑制作用尤为明显.化疗诱导产生的免疫抑制效应以及肿瘤血管生成减少导致的肿瘤组织中血药浓度下降,可能是影响胰腺癌疗效的重要原因,有望成为提高胰腺癌化疗效果的重要靶点.     

西罗莫司对创伤小鼠脾脏树突状细胞诱导T淋巴细胞应答能力的影响

目的 了解西罗莫司对创伤小鼠脾脏树突状细胞(DC)诱导异源性T淋巴细胞应答能力的体外调节作用.方法 将24只BALB/c小鼠按随机数字表法分为对照组与创伤组,每组12只.将创伤组麻醉后造成失血合并闭合性骨折,对照组仅麻醉不致伤,24 h后分离2组小鼠脾脏DC.将2组DC分为西罗莫司阴性对照组和创伤组(不用西罗莫司处理),以及西罗莫司阳性对照组和创伤组(用10μg/L西罗莫司处理6 h).检测各组DC自噬活性(用荧光强度值表示)及DC介导的混合淋巴细胞反应(MLR)变化(用吸光度值表示).流式细胞仪检测细胞表面主要组织相容性复合物(MHC)Ⅱ与共刺激分子CD40、CD80、CD86表达.用ELISA法检测LPS刺激后DC中IL-12p40、IL-12p70和IL-10的水平.对数据进行单因素方差分析.结果 (1)西罗莫司阴性创伤组小鼠脾脏DC自噬活性(荧光强度值为13±2)及其介导的MLR强度均较西罗莫司阴性对照组(荧光强度值为22±6)明显减弱(F=212.836,P<0.05).与西罗莫司阴性对照组和创伤组比较,西罗莫司阳性对照组和创伤组自噬活性(45±8、44±8)均明显增强(F=212.836,P<0.05或P<0.01).西罗莫司阳性创伤组MLR强度较西罗莫司阴性创伤组明显增强(F值分别为101.426、86.533,P值均小于0.05).(2)西罗莫司阴性创伤组小鼠脾脏DC表面的MHCⅡ[(60±9)%]及CD40[(4±1)%]表达较西罗莫司阴性对照组[(85±6)%、(8±1)%]明显降低(F值分别为37.918、40.426,P值均小于0.05),西罗莫司阳性创伤组MHCⅡ表达[(78±7)%]较西罗莫司阴性创伤组明显提高(F=37.918,P<0.05).(3)两罗莫司阴性创伤组小鼠脾脏DC的IL-12p40、IL-12p70表达水平[(120±13)、(10±3)pg/mL]较西罗莫司阴性对照组[(200±25)、(20±6)pg/mL]明显降低(F值分别为218.646、310.253,P值均小于0.05);与西罗莫司阴性对照组和创伤组比较,西罗莫司阳性对照组和创伤组IL-12p40[(560±34)、(540±29)pg/mL]、IL-12p70[(55±8)、(60±11)pg/mL]表达水平均明显提高(F值分别为218.646、310.253,P值均小于0.01),IL-10表达水平降低(F=246.108,P<0.01).结论 西罗莫司在体外可部分改善创伤小鼠DC功能,并提高其诱导T淋巴细胞的应答能力.     

Nod样受体蛋白3炎性体抑制剂格列苯脲对机械通气致小鼠急性肺损伤的保护作用

目的 探究Nod样受体蛋白3(Nod-like receptor protein-3,NLRP3)炎性体抑制剂格列苯脲对机械通气导致的小鼠急性肺损伤是否具有保护作用. 方法 28只7～9周的清洁级ICR雄性小鼠,按完全随机分组法分为4组:对照组(CON组,6只)、格列苯脲组(GLY组,6只)、机械通气组(VEN组,8只)和格列苯脲+机械通气组(GLY+VEN组,8只).VEN组和GLY+VEN组机械通气4h后与CON组及GLY组麻醉插管后4h测定肺泡灌洗液中蛋白含量及炎性细胞数量,测量肺组织湿/干重比(wet/dry,W/D),观察肺组织病理学改变,ELISA法检测肺组织IL-1β、IL-6、TNF-α的含量. 结果 VEN组肺泡灌洗液中蛋白浓度和细胞数量[(0.534±0.104) g/L和(3.4±0.7)×105/ml]比CON组[(0.167±0.021) g/L和(1.9±0.5) ×105/ml]升高(P＜0.01);GLY+VEN组肺泡灌洗液中蛋白浓度和细胞数量[(0.425±0.083) g/L和(2.4±0.6) ×105/ml]比VEN组下降(P＜0.05).VEN组肺组织W/D(5.1±0.5)与CON组(4.4±0.4)比较,差异有统计学意义(P＜0.01),GLY +VEN组肺组织W/D(4.7±0.4)与VEN组比较,差异有统计学意义(P＜0.05).VEN组和GLY+VEN组肺组织中IL-1β、IL-6和TNF-α蛋白表达与CON组比较,明显升高(P＜0.05),GLY+VEN组IL-1β和IL-6表达与VEN组比较,表达明显降低(P＜0.05).结论 机械通气前给予格列苯脲可有效减少小鼠肺组织炎症细胞聚集,减轻肺水肿,机制可能与其抑制炎性体的激活有关.     

大鼠精索静脉曲张模型及其高位结扎术后睾丸生精细胞凋亡及其IL-1和NO含量的变化

目的:研究大鼠左侧精索静脉曲张(VC)模型及其高位结扎术后睾丸生精细胞凋亡及白细胞介素-1(IL-1)和一氧化氮(NO)含量的变化。方法:选用雄性SD大鼠60只,均选择左侧精索静脉作为研究对象,建立VC模型。将大鼠随机分为3组:假手术组(SO)15只,VC后高位结扎组(VCT)组15只和VC模型对照组30只。模型对照组中随机选取15只大鼠作为VC1组,余下15只大鼠作为VC2组,分别测定VC1组和SO组、VC2组和VCT组大鼠精液质量及睾丸组织中IL-1和NO的含量并加以比较,采用TUNEL检测睾丸生精细胞凋亡情况。结果:所有大鼠均建模成功,VC1组精子浓度[(1.54±1.16)×10~6/ml]和精子活力[(44.23±15.46)%]均显著低于SO组[2.80±1.62)×10~6/ml、(72.34±12.62)%](P0.05),VCT组精子浓度[1.82±1.34)×10~6/ml]和精子活力[(51.21±12.62)%]较VC2组有显著提高[(1.04±1.21)×10~6/ml、(39.23±13.21)%](P0.05)。大鼠左侧睾丸NO[(0.172±0.030)ng/ml]、IL-1[(1.468±0.080)mg/ml]含量VC1组明显高于SO组[(0.134±0.021)ng/ml、(0.782±0.079)mg/ml](P0.05),VC2组左侧睾丸NO[(0.198±0.020)ng/ml]、IL-1[(1.994±0.090)mg/ml]含量明显高于VCT组[(0.141±0.010)ng/ml、(0.781±0.036)mg/ml](P0.05),而右侧睾丸2组比较差异无显著性(P0.05),而且NO与IL-1含量之间呈正相关关系(r=0.492,P0.01)。VC1组大鼠双侧睾丸生精细胞大量凋亡,左、右侧睾丸生精细胞凋亡指数差异有统计学意义(P0.05),SO组左、右侧睾丸生精细胞凋亡指数无明显差异(P0.05),2组间同侧睾丸生精细胞凋亡指数差异显著,均有统计学意义(P0.01);VCT组大鼠左、右侧睾丸生精细胞凋亡指数差异有统计学意义(P0.05);VC2组左、右侧睾丸生精细胞凋亡指数无明显差异(P0.05);2组间同侧睾丸生精细胞凋亡指数差异显著,均有统计学意义(P0.01)。VC2组、VCT组组内同侧睾丸生精细胞凋亡指数无明显差异(P0.05),但VC2组、VCT组2组间同侧睾丸生精细胞凋亡指数差异显著,均有统计学意义(P0.01)。结论:VC致睾丸组织中NO和IL-1含量升高,并加重睾丸生精细胞凋亡,可能是其致睾丸损伤、影响睾丸生精功能障碍的原因之一。     

自体血回输对全髋关节置换术患者免疫功能的影响

目的 比较回收式自体血回输和异体血输血对全髋关节置换手术患者免疫功能的影响. 方法 选择50例全髋关节置换手术,随机数字表法分为自体血回输组(A组)和异体血输血组(B组),每组25例.术中根据血容量丢失情况分别用自体血回输及异体血输血,于麻醉前、输血后第2天和输血后第5天采用流式细胞仪测定血浆CD4+T淋巴细胞(CD4+)、CD8+T淋巴细胞(CDx+)、自然杀伤细胞(natural killer cell,NK)的比例以及白细胞介素(interleukin,IL)-2(IL-2)和白细胞介素-6(IL-6)的值.结果 B组输血后CD4+、CD8+、NK细胞、IL-2的值在第2天[(35±6)、(22±6)、(7±3)％、(523±407) ng/L]和第5天[(35±6)、(26±8)、(6±4)％、(442±376) ng/L]均低于术前[(40±8)、(28±9)、(9±4)％、(839±472)ng/L] (P＜0.05);A组输血后CD4+、CD8+的值在第5天[(39±8)、(27±9) ng/L]、NK细胞、IL-2的值在第2天[(8±4)％、(807±534) ng/L]和第5天[(8±4)％、(821±437) ng/L]均较术前有所下降,但差异无统计学意义(P＞0.05);IL-6的值在第2天[(3198±698) ng/L]和第5天[(3076±703) ng/L]均较术前[(2593±784) ng/L]有所升高(P＜0.05). 结论 自体血回输对全髋关节置换手术患者细胞和体液免疫功能均无明显抑制作用,是安全、可靠的血液保护方式.     

静脉应用抑肽酶对大鼠肺移植模型缺血再灌注损伤的作用

目的 探讨静脉应用抑肽酶对肺移植后肺缺血再灌注损伤的作用和机制.方法 利用移植肺冷缺血14 h建立的大鼠肺移植缺血再灌注损伤模型,考察抑肽酶对缺血再灌注损伤的影响,并检测细胞因子等指标探讨机制.结果 抑肽酶组较对照组移植肺氧合好、湿干比小,同时支气管肺泡灌洗液中白细胞介素(IL)-2[(113±32)μg/L和(162±43)μg/L,P＜0.05]、血清中IL-8[(7.26±1.01)ng/L和(9.43±0.97)ng/L,P＜0.05]和肿瘤坏死因子(TNF)-α[(152.3±36.4)ng/L和(211.6±52.7)ng/L,P＜0.05]、肺组织中髓过氧化物酶活性[(2.36±0.62)U/g和(3.98±0.36)U/g,P＜0.05]都显著降低.结论 静脉应用抑肽酶能够减轻缺血再灌注损伤,机制可能包括:减少IL-2的释放、抑制TNF-α活化和IL-8产生,抑制中性粒细胞的聚集、激活和脱颗粒.     

自身免疫性前列腺炎大鼠模型的建立

目的:使用前列腺蛋白提纯液建立自身免疫性前列腺炎大鼠模型。方法:选用36只Wistar大鼠,随机分为对照组、低浓度组和高浓度组,每组12只。对照组注射生理盐水,低浓度和高浓度组实验大鼠于0、14 d分别注射等剂量15 mg/ml及80 mg/ml浓度的前列腺蛋白提纯液,4周后处死大鼠,前列腺组织HE染色,取大鼠外周血检测血清炎症因子IL-8、IL-10,血清免疫球蛋白IgA、IgM,辅助性T细胞Th1/Th2等指标。结果:高浓度组有3只大鼠死亡,对照组与低浓度组均无死亡。前列腺大体观察对照组无明显变化,低浓度组大鼠前列腺体积增大,质地稍硬,高浓度组大鼠前列腺质地坚硬,与周围组织粘连。实验组病理切片显示前列腺组织腺体结构破坏,有炎性细胞浸润。大鼠血清IL-8指标低浓度组[(129.07±11.48)pg/ml]、高浓度组[(147.58±17.70)pg/ml]与对照组[(94.12±7.04)pg/ml]比明显升高(P0.05);大鼠血清IL-10指标低浓度组[(227.14±18.19)pg/ml]、高浓度组[(187.14±16.32)pg/ml]与对照组[(252.48±21.72)pg/ml]相比显著降低(P0.05)。大鼠血清IgA与对照组[(0.19±0.14)mg/ml]相比,低浓度组[(0.25±0.37)mg/ml]和高浓度组[(0.31±0.42)mg/ml]明显升高(P0.05);大鼠血清IgM指标低浓度组[(0.23±0.41)mg/ml]、高浓度组[(0.34±0.58)mg/ml]与对照组[(0.17±0.33)mg/ml]相比,显著升高(P0.05)。外周血辅助性T细胞Th1/Th2未见明显改变。结论:低、高浓度组大鼠造模均获成功。使用低浓度的前列腺蛋白提纯液造模的动物死亡率低,病理改变及血清炎症因子变化符合自身免疫性前列腺炎的表现,可作为制备自身免疫性前列腺炎的可靠模型浓度。     

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.     

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.     

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.     

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.     

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.     

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.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.