糖皮质激素加剧缺血诱导神经细胞损害的研究

目的观察糖皮质激素对神经细胞缺血性损害的影响。方法21只雄性沙士鼠随机分为3组，未缺血组(A组，n=7)，缺血组(B组，n=7)和实验组(C组，n=7)。A和B组脑室内给予生理盐水10μl，而C组给与地塞米松3μg。A组未作缺血处理，B组和C组1h后阻断双侧颈总动脉，2.5min后恢复血流。实验过程中控制脑温度在37.5℃±0.2℃。1周后将动物脑组织取出，做5μm厚的脑组织切片，经苏木素-伊红染色后计数海马CA1区1mm长度内残存的锥体细胞数。结果(1)与A组相比，B组和C组残存细胞数明显减少(P＜0.01);(2)C组的残存细胞数明显少于B组(P＜0.01)。结论(1)前脑缺血2.5min可致海马CA1区的锥体神经细胞的明显损害；(2)地塞米松明显加剧缺血时的脑细胞死亡。     

参附注射液对兔脊髓缺血损伤保护作用的量效关系研究

目的探讨参附注射液对脊髓缺血性损伤保护作用的剂量效应关系。方法24只雄性新西兰大白兔,随机分为四组A组(n=6),单纯缺血再灌注组,B组(n=6)、C组(n=6)和D组(n=6)分别于缺血前30min内持续恒速静脉输入参附注射液5ml·kg-1、10ml·kg-1、20ml·kg-1;采用肾下主动脉阻断法造成脊髓缺血(20min);术后观察神经功能变化并记录再灌注1h、4h、8h、12h、24h和48h神经功能评分,再灌注48h处死动物后取脊髓(L5～7)标本行病理学观察。结果术后神经功能评分除再灌注1hD组与A组之间无显著性差异,其余各时间点B组、C组和D组均明显高于A组(P<0．05),B组、C组和D组间则无显著性差异(P>0．05),且48h时各组神经功能评分分别为A组0．5±0．8、B组3．2±0．9(P<0．001)、C组3．0±1．0,(P<0．001)和D组2．7±0．8(P<0．05);再灌注48h脊髓前角正常运动神经元计数B组(78±25,P<0．001)、C组(41±23,P<0．05)和D组(42±27,P<0．05)均高于A(8±7)组,B组与C组、D组间亦有显著性差异(P<0．05)。结论参附注射液对脊髓缺血性损伤有保护作用,但无明显剂量效应关系。     

肺纤维化对大鼠阴茎勃起功能的影响

目的:研究肺纤维化对大鼠勃起功能的影响及其机制。方法:12周雄性SD大鼠40只,随机分为4组:正常对照4周组(A组)、6周组(B组)和肺纤维化大鼠4周组(C组)、6周组(D组)各10只,分别用生理盐水(A、B组)及博莱霉素(5 mg/kg)气管内注入,饲养4周(A、C组)、6周(B、D组)后,测定大鼠血清睾酮、动脉血气分析、阴茎海绵体内压/平均颈动脉压(ICP/MAP),取阴茎标本测定NOS活性及cGMP含量,实时荧光PCR检测eNOS、iNOS和nNOS的mRNA在阴茎海绵体的表达,W estern印迹检测阴茎海绵体eNOS蛋白的表达。结果:电刺激的3 V,5 V C组ICP/MAP×100(16.37±2.19,27.19±3.18)较A组(30.78±2.66,50.09±6.97)显著降低(P<0.05),D组ICP/MAP×100,3 V,5 V(10.17±1.31,17.40±1.74)较B组(31.45±3.07,51.23±7.23)显著降低(P<0.05),D组ICP/MAP×100值较C组显著降低(P<0.05)。C组PaO2(75.50±13.87)mmHg较A组(103.80±6.88)mmHg显著降低(P<0.05),D组PaO2(83.60±5.50)mmHg较B组(102.70±5.77)mHg显著降低(P<0.05)。C组血清睾酮水平(391.1±264.7)ng/d l较A组(175.9±53.0)ng/d l显著升高(P<0.05),D组血清睾酮水平(745.4±408.8)ng/d l较B组(177.8±52.3)ng/d l显著升高(P<0.05),同时D组血清睾酮水平较C组显著升高(P<0.05)。C组NOS活性及cGMP含量[(1.50±0.14)U/mg prot,(35.69±3.64)pmol/mg]较A组[(2.66±0.39)U/mg prot,(51.10±7.22)pmol/mg]显著降低(P<0.05),D组NOS活性及cGMP含量[(1.40±0.20)U/mg prot,(34.55±4.30 pmol/mg)]较B组[(2.75±0.36)U/mg prot,(52.15±6.86)pmol/mg]显著降低(P<0.05),C组与D组比较NOS活性及cGMP含量无显著性差异(P>0.05)。C组eNOS蛋白表达量(0.79±0.01)较A组(0.87±0.01)显著降低(P<0.01),D组eNOS蛋白表达量(0.71±0.02)较B组(0.88±0.01)显著降低(P<0.05),D组较C组eNOS蛋白表达量显著降低(P<0.05)。C组eNOS mRNA表达量(4.46±0.92)较A组(2.61±0.68)显著升高(P<0.05),D组eNOS mRNA(2.79±0.60)表达量与B组(2.69±0.65)无显著性差异(P>0.05),nNOS及iNOS的mRNA表达量在A、B组与C、D组间均无显著性差异(P>0.05)。结论:肺纤维化可通过抑制阴茎海绵体eNOS蛋白的表达、降低总NOS活性及cGMP含量等机制抑制阴茎勃起功能。     

粒细胞集落刺激因子动员BMSCs归巢治疗大鼠脊髓损伤的疗效观察

目的观察粒细胞集落刺激因子(granulocyte colony stimulating factor,G-CSF)动员BMSCs归巢对大鼠脊髓损伤的治疗效果,评估G-CSF动员BMSCs治疗脊髓损伤的可行性。方法将24只成年健康雌性SD大鼠术前12 h于鼠尾静脉注射绿色荧光蛋白(green fluorescence protein,GFP)标记的BMSCs(GFP-BMSCs),并随机分为假手术组(A组)、假手术+G-CSF组(B组)、脊髓损伤组(C组)、脊髓损伤+G-CSF组(D组),每组6只。C、D组采用T10水平脊髓半切法建立脊髓损伤模型,A、B组仅行椎板切除,不损伤脊髓;术后1 h B、D组分别注射G-CSF(10μg/kg·d),连续注射3 d;A、C组注射等量生理盐水。术后1、3、7、14、21、28 d采用BBB评分行大鼠双后肢神经功能评估,并采用ELISA法检测血清TNF-α和基质细胞衍生因子1(stromal cell-derived factor 1,SDF-1)表达。术后28 d处死大鼠取脊髓样品行免疫组织化学染色观察细胞因子SDF-1、BDNF、VEGF和TNF-α表达,免疫荧光染色观察GFP-BMSCs阳性细胞及双染荧光黄色的GFP/神经元核抗原(neuronal nuclei,NeuN)阳性神经元细胞和GFP/胶质原纤维酸性蛋白(glial fibrillary acidic protein,GFAP)阳性神经胶质细胞数;并采用TUNEL法检测细胞凋亡。结果术后各时间点A、B组BBB评分较术前无明显变化;术后1 d,C、D组BBB评分降至最低,后逐渐上升。除术后1 d外,其余各时间点D组BBB评分均显著高于C组(P0.05)。术后3、7、14、21、28 d,C、D组TNF-α和SDF-1含量均明显高于A、B组(P0.05);但D组各时间点TNF-α含量显著低于C组,SDF-1含量显著高于C组(P0.05)。免疫组织化学染色示,术后各时间点C、D组SDF-1、BDNF、VEGF和TNF-α表达均显著高于A、B组(P0.05);D组SDF-1、BDNF、VEGF表达显著高于C组,TNF-α表达显著低于C组(P0.05)。免疫荧光染色示,C、D组GFP-BMSCs、GFP/NeuN、GFP/GFAP阳性细胞数均显著多于A、B组,D组显著多于C组,差异均有统计学意义(P0.05)。TUNEL法检测示,C、D组凋亡细胞数目显著低于A、B组,D组显著低于C组,差异均有统计学意义(P0.05)。结论 G-CSF可以动员BMSCs归巢至大鼠脊髓损伤部位并参与修复,其作用可能与其下调TNF-α减少细胞凋亡,上调SDF-1、BDNF、VEGF促进BMSCs迁移有关。     

骨髓间充质干细胞联合定向诱导的神经元样细胞移植治疗脊髓损伤

[目的]探讨一定条件下骨髓间充质干细胞向神经元样细胞分化的能力,并进一步研究两种细胞联合移植治疗脊髓损伤(spinalcord injury,SCI)的效果。[方法]选取3个月龄雌性SD大鼠62只,2只处死后提取骨髓间充质干细胞用于细胞培养和分化研究,剩余大鼠采用改良Allen’s法制备T9～11SCI模型,然后随机分为4组(n=15),A组为空白对照组,B组为干细胞组,C组为神经元样细胞组,D组为联合移植组。诱导后的细胞采用免疫荧光方法检测细胞表面特异性标志,各组细胞用Hoechst33342标记,脊髓损伤模型建立1周后将细胞以局部注射的方法移植到损伤区,细胞移植后的1、2、4、6周对各组动物进行Basso-Beattie-Bresnahan(BBB)评分,并行HE染色、荧光显微镜、免疫荧光法检测细胞在体内的存活和分化。[结果]术后2、4、6周各细胞移植组BBB评分较空白对照组相比显著增加(P0.05),D组高于B、C两组(P0.05),B、C两组组间比较差异无统计学意义(P0.05)。HE染色示B、C、D组术后6周的脊髓空洞较A组均减小,以D组最明显;荧光显微镜显示移植的细胞存活于脊髓损伤的区域;免疫荧光染色显示诱导后的细胞与体内存活的细胞表面特异性标志神经元特异性烯醇化酶(neuron specific enolase,NSE)、神经丝蛋白200(neuroflament200,NF-200)表达呈阳性,胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)表达呈弱阳性,其中D组NSE和NF-200阳性细胞数量较多,B、C两组较少。[结论]体内体外一定条件下骨髓间充质干细胞都有向神经元样细胞分化的能力;骨髓间充质干细胞和定向诱导的神经元样细胞都可用于移植治疗脊髓损伤,但以两者联合移植治疗的效果最佳。     

黄芪对大鼠睾丸扭转/复位模型保护作用的研究

目的:探讨黄芪注射液对大鼠睾丸扭转/复位模型的保护作用。方法:将30只健康雄性Wistar大鼠分为3组。分别为假手术对照组(A组,n=10);睾丸扭转/复位组(B组,n=10);睾丸扭转/复位+腹腔内注射黄芪注射液组(C组,n=10)。按Turner法建立睾丸扭转模型,喂养至术后7d处死,切取扭转侧睾丸检测凋亡指数(AI)及谷胱甘肽过氧化物酶活力及丙二醛含量。结果:A、B、C三组扭转侧睾丸AI分别为5.82±1.21、36.18±8.40、20.39±3.57,B、C组明显高于对照组(P(0.05),B组明显高于C组(P(0.05)。A、B、C三组扭转侧睾丸谷胱甘肽过氧化物酶活力分别为48.03±2.01、30.93±1.25、38.44±1.06U/mg;丙二醛含量分别为1.43±0.17、3.98±0.36、2.57±0.53nmol/ml,三组之间比较均有显著性差异(P(0.05)。结论:黄芪注射液可明显减少扭转侧睾丸生殖细胞凋亡,保护谷胱甘肽过氧化物酶活力,减轻脂质过氧化程度。     

携载川芎嗪缓释微粒导电水凝胶修复脊髓损伤实验研究

目的 探讨携载川芎嗪缓释微粒导电水凝胶（以下简称“TGTP水凝胶”）对脊髓损伤大鼠的神经保护作用。方法 将48只成年雌性SD大鼠随机分为4组,假手术组（A组）、模型组（B组）、导电水凝胶组（C组）、TGTP水凝胶组（D组）,每组12只。A组仅行椎板切除术,B～D组均制备脊髓完全横断大鼠模型。分别于造模前及造模后1、3、7、14、28 d采用BBB评分评估各组大鼠后肢运动功能恢复情况。造模后28 d处死动物取材行劳克坚牢蓝（luxol fast blue,LFB）染色检测髓鞘再生情况;Nissl染色检测神经元存活情况;免疫组织化学染色评估炎症相关因子（NF-кB、TNF-α、IL-10）表达情况;免疫荧光染色和Western blot评估神经丝蛋白200(neurofilament 200,NF200)表达。结果 造模后各时间点A组BBB评分均优于其余3组（P<0.05）;14、28 d C、D组BBB评分差异无统计学意义（P>0.05）,但D组BBB评分明显优于B组（P<0.05）。LFB染色与Nissl染色示,A组神经元及髓鞘结构完整,D组髓鞘完整性与神经元存活数量...     

高草酸尿和输尿管梗阻对鼠肾小管上皮细胞凋亡的影响

目的探讨高草酸尿和输尿管梗阻(UUO)对鼠肾小管上皮细胞凋亡的影响. 方法雄性成年Wistar大鼠40只,随机分为4组,每组10只,A组为对照组,B组为高草酸尿组,C组为输尿管梗阻组,D组为高草酸尿并输尿管梗阻组.所有大鼠均在术后2周处死并取左肾,常规HE染色检测肾小管间质草酸盐结晶沉着情况;原位末端标记法(TUNEL)检测肾小管上皮细胞凋亡情况. 结果 B组和D组组织切片肾小管腔内可见明显草酸盐晶体沉着,A组和C组未见晶体沉着.计数5个高倍镜视野的细胞,A、B、C、D各组肾小管上皮细胞凋亡数分别为1.1±1.1,31.3±8.0,145.0±33.4,275.8±51;A组与各组相比差异均有显著性意义(P<0.001),B组与C组、D组相比差异有显著性意义(P<0.001),C组与D组相比差异亦有显著性意义(P<0.01). 结论高草酸尿可致肾小管间质草酸盐结晶沉着;完全性输尿管梗阻并高草酸尿使肾小管上皮细胞凋亡水平明显增高,且造成肾脏损害,输尿管梗阻是比高草酸尿更重要的促细胞凋亡因素.     

吸烟对大鼠生精细胞发育影响的研究

目的:探讨吸烟对大鼠生精细胞发育的影响。方法:自制吸烟机将大鼠制成被动吸烟模型,大鼠随机分成被动吸烟组(A、B组各10只)及相应对照组(C、D组各10只),A、B组被动吸烟8周,随后处死A组及相应对照组C组大鼠;B组停止被动吸烟后与其相应对照组D组继续观察48 d后处死。流式细胞术(FCM)检测各组大鼠生精细胞周期,放免法测定血睾酮(T)、黄体生成素(LH)水平,HE染色观察睾丸组织结构变化,透射电镜观察睾丸超微结构改变。结果:与C组比较,A组大鼠精子、精子细胞[(18.76±3.58)%]和初级精母细胞[(5.71±1.18)%]明显减少(P均<0.01),而精原细胞[(55.98±5.35)%]增加(P<0.01),增殖指数降低(P<0.01)。A组大鼠生精小管壁变薄,层次减少,生精小管内精原细胞减少,精母细胞固缩。间质细胞内质网扩张脱颗粒,高尔基复合体减少,支持细胞脂滴和溶酶体增多。A组大鼠T、LH水平低于C组(P均<0.01)。B组大鼠停止被动吸烟后,精子、精子细胞、初级精母细胞比例和增殖指数上升,T、LH水平升高,但仍低于D组。结论:吸烟导致大鼠睾丸生精上皮损伤及间质细胞和支持细胞受损,同时伴有T和LH水平的下降,延缓生精细胞增殖,停止吸烟后生精功能有逐渐恢复的趋势。     

基于TNFR/RIPK1通路探索紫草素对大鼠脊髓损伤的作用及机制

目的:初步探讨紫草素对大鼠急性脊髓损伤(spinal cord injury,SCI)后神经功能恢复的影响及作用机制。方法:将96只Sprague-Dawley(SD)雄性大鼠分为4组:假手术组,即A组;假手术+紫草素组,即B组;脊髓损伤+二甲基亚砜(dimethyl sulfoxide,DMSO)组,即C组;脊髓损伤+紫草素组,即D组;每组24只。C、D组采用钳夹法制作大鼠急性SCI 模型。所有大鼠硬膜下置管,A 组不给药,B组和D组造模后30 min 经导管注射紫草素100 mg·kg^-1,C组注射等量 DMSO,每日1次,至取材时间点。各组分别于造模后6、12 h和3 d 每组取8只大鼠,行 Basso-Beattie-Bresnahan(BBB)评分及造模后1、3、7、14、21 d行斜板实验,再处死动物取脊髓组织。造模后1 h 每组大鼠腹腔注射碘化丙啶(propidine iodide,PI)1 mg·kg^-1,术后24 h取材检测脊髓组织 PI 红染细胞数;24 h 时取材采用苏木素-伊红(haematoxylin eosin,HE)染色观察脊髓损伤情况,尼氏(Nissl)染色观察神经元存活数量,使用Western-blot技术检测 B细胞淋巴瘤-2(B cell lymphoma-2,Bcl-2)蛋白及凋亡相关蛋白受体相互作用蛋白激酶1(receptor-interacting protein kinase 1,RIPK1)的表达水平。结果:造模后A组和B组各时间点的 BBB 评分均正常,C、D组各时间点均低于A、B组,D组造模后12 h和3 d的 BBB 评分高于同时间点C组(P<0.05)。造模后12 h,D组PI 红染细胞较C 组明显减少,神经元崩解减轻(P<0.05)。造模后24 h,A 组和 B 组脊髓组织 HE 和 Nissl 染色正常,D 组脊髓组织损伤程度和存活神经元数量均优于 C 组(P<0.05)。Bcl-2、RIPK1蛋白在A 组、B 组表达很低; RIPK1 在C组表达明显增高,在D组表达明显下降,差异有统计学意义(P<0.05);Bcl-2蛋白在D 组表达高于C 组(P<0.05)。结论:紫草素可减轻大鼠急性SCI后的病理变化,改善行为学评分,促进脊髓神经功能恢复。其具体机制可能与抑制TNFR/RIPK1信号通路介导的坏死性凋亡有关。     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

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.     

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.     

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.