七氟烷预处理对脂多糖致大鼠急性肺损伤的保护作用

目的 评价七氟烷预处理对脂多糖(lipopolysaccharide,LPS)所致大鼠急性肺损伤(acute lung injury,ALI)的影响.方法 72只SD大鼠随机分成6组:NS组、LPS组和七氟烷预处理(S-1 h组、S-6 h组、S-12 h组、S-24 h组).通过气管内滴注LPS建立大鼠ALI模型.大鼠在气道内给予LPS或NS后6 h处死,检测不同时间点七氟烷预处理(2.4%,30 min)对支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)中白细胞计数、细胞因子TNF-α和IL-1β水平,肺组织髓过氧化物酶(myeloperoxidase,MPO)活性,肺血管通透性及肺组织病理学等的影响.结果 与NS组相比,LPS组肺组织损伤程度,BALF白细胞计数以及TNF-α和IL-1β水平,血管通透性和肺组织MPO活性均显著增高(P<0.01).给予LPS前1 h和24 h七氟烷预处理能降低肺组织MPO活性,BALF中IL-1β水平及白细胞计数(P<0.01),而S-6h组和S-12 h组与IPS组相比无明显差别.七氟烷预处理均能够降低肺血管通透性和BALF中TNF-α水平(P<0.01),且以S-1 h和S-24h组为显著(P<0.01).提示七氟烷预处理对LPS所致肺损伤具有早期和延时的保护作用.结论 气道内给予LPS1 h和24 h前七氟烷预处理对LPS致大鼠ALI具有保护作用.     

富氢液对创伤性颅脑损伤大鼠急性肺损伤的影响及Nrf2/HO-1信号通路在其中的作用

目的评价富氢液对创伤性颅脑损伤(TBI)大鼠急性肺损伤的影响及核因子E2相关因子2/血红素氧合酶-1(Nrf2/HO-1)信号通路在其中的作用。方法成年雄性SD大鼠48只, 体重220～250 g, 采用随机数字表法分为4组(n=12):假手术组(S组)、TBI组(T组)、TBI+富氢液组(T+H组)和TBI +富氢液+鸦胆子苦醇组(T+H+B组)。采用控制型皮质撞击损伤法制备TBI模型。T+H+B组于造模前10 d开始隔天腹腔注射Nrf2抑制剂鸦胆子苦醇0.4 mg/kg;T+H组和T+H+B组于造模后1和6 h时腹腔注射富氢液10 ml/kg。造模后24 h时, 收集支气管肺泡灌洗液(BLAF)测定蛋白浓度, 取右颈总动脉血和肺组织, 采用ELISA法测定血清和肺组织TNF-α、IL-10和高迁移率族蛋白B1(HMGB1)的水平, 测定肺组织湿重/干重(W/D)比值, HE染色后观察肺组织病理学结果并进行评分, 采用Western blot法检测肺组织核Nrf2、总Nrf2和HO-1表达, RT-PCR法检测肺组织HO-1 mRNA表达。结果与S组相比, T组和T+H组BALF蛋白...     

核因子-κB介导脂多糖诱导急性肺损伤大鼠高迁移率族蛋白B1的表达

目的探讨核因子(NF)-κB在脂多糖诱导大鼠急性肺损伤过程中对肺组织高迁移率族蛋白B1(HMGB1)表达的影响。方法采用腹腔注射脂多糖(LPS)致大鼠脓毒症急性肺损伤模型。取健康SPF级雄性SD大鼠72只,体重180~220g,采用随机数字表法,分为对照组(C组,n=6)、急性肺损伤组(L组,n=30)、吡咯烷二硫代氨基甲酸盐(PDTC)溶剂对照组(P组,n=6),PDTC治疗组(LP组,n=30)。各组分别给予腹腔注射磷酸盐缓冲液(PBS)(C和P组)或LPS(L和LP组);P组和LP组在PBS或LPS注射前15min,给予腹腔注射PDTC 100mg/kg。C组和P组腹腔注射PBS后的16h,L组和LP组注射LPS后的16h后各取6只大鼠检测其肺湿/干重比(W/D);C组和P组腹腔注射PBS后的16h,L组和LP组注射LPS后的4h(T1)、8h(T2)、16h(T3)、24h(T4)和48h(T5)时各取6只大鼠经处理后采用ELISA法检测支气管肺泡灌洗液(BALF)中髓过氧化物酶(MPO)和白细胞介素6(IL-6)水平,Western blot法检测肺组织HMGB1的表达水平,苏木精-伊红(HE)染色观察肺组织的病理变化。结果与C组比较,L组肺组织W/D、BALF中MPO和IL-6水平明显升高(P0.01),病理切片显示严重肺组织损伤,T2~T4时肺组织中HMGB1的表达水平明显升高(P0.05);使用PDTC治疗后,与L组比较,肺组织W/D、BALF中MPO和IL-6水平明显降低(P0.01),病理示肺损伤程度明显减轻;T2~T4时肺组织HMGB1表达水平明显降低(P0.05)。结论在脂多糖诱导急性肺损伤中,被激活的NF-κB通过介导晚期炎症因子HMGB1的表达来参与急性肺损伤的发生与发展过程。     

右美托咪定通过抑制JAK2/STAT3通路改善脂多糖诱导的小鼠急性肺损伤

目的研究右美托咪定对脂多糖(LPS)诱导的急性肺损伤(ALI)小鼠JAK2/STAT3通路的作用。方法雄性昆明小鼠36只,随机均分为三组:正常组(C组)、模型组(L组)和右美托咪定预处理组(D组)。取小鼠右肺下叶,称量并计算湿/干比重(W/D),对右肺上叶进行苏木素-伊红(HE)染色观察小鼠肺组织病理学改变,BCA法检测支气管肺泡灌洗液(BALF)中蛋白含量,用ELISA试剂盒检测BALF上清中肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)及髓过氧化物酶(MPO)水平;qRT-PCR定量分析肺组织中TNF-α、IL-6mRNA水平;Western blot方法检测肺组织中p-JAK2、JAK2、p-STAT3、STAT3蛋白的含量。结果与L组比较,C组、D组肺损伤评分明显降低、小鼠肺W/D、BALF中蛋白含量明显减少,BALF中TNF-α、IL-6及MPO浓度明显降低,肺组织TNF-α和IL-6mRNA表达明显减少,p-JAK2/JAK2和p-STAT3/STAT3相对量明显减少(P0.05)。结论右美托咪定可能通过抑制JAK2/STAT3通路减轻LPS诱导的小鼠ALI。     

c-Jun氨基末端激酶在大鼠内毒素性急性肺损伤中的作用

目的 评价c-Jun氨基末端激酶(JNK)在大鼠内毒素性急性肺损伤中的作用.方法 雄性成年SD大鼠80只,体重250～300 g,采用随机数字表法,将其随机分为4组(n=20):对照组(C组)、急性肺损伤组(ALI组)、SP600125组(S组)和二甲基亚砜组(D组).ALI组、S组和D组尾静脉注射LPS 5 mg/kg,C组尾静脉注射等容量生理盐水;S组和D组给予LPS后,分别尾静脉注射JNK抑制剂SP600125 30 mg/kg或二甲基亚砜0.2 ml.于给予LPS后4 h时,各组处死10只大鼠,回收支气管肺泡灌洗液(BALF)并取肺组织,采用ELISA法检测BALF中TNF-α和IL-1β的浓度,计算肺组织湿重/干重比(W/D比),观察肺组织病理学结果,并进行肺损伤评分.各组其余10只大鼠观察至给予LPS后48 h,记录大鼠生存情况.结果 与C组比较,其余各组BALF中TNF-α和IL-1β的浓度、肺组织W/D比和肺损伤评分升高,生存率降低(P<0.05或0.01);与ALI组比较,S组BALF中TNF-α和IL-1度、肺组织W/D比和肺损伤评分降低,生存率升高(P<0.01),D组差异无统计学意义(P>0.05).结论 JNK的活化参与了大鼠内毒素性急性肺损伤的发生发展.

Abstract：

Objective To evaluate the role of c-Jun N-terminal kinase (JNK) in lipopolysaccharide (LPS)-induced acute lung injury ( ALI) in rats.Methods Eighty male SD rats weighing 250-300 g were randomly divided into 4 groups ( n = 20 each) : control group (group C) ; ALI group; LPS + SP600125 (JNK inhibitor)group (group S) and LPS+ DMSO (the solvent) group (group DMSO) . ALI was induced by intravenous LPS 5mg/kg. In S and DMSO groups, SP600125 30 mg/kg and DMSO 0.2 ml were injected intravenously after LPS administration respectively. Ten animals were sacrificed by exsanguinafions at 4 h after LPS administration in each group. The broncho-alveolar lavage fluid (BALF) was colleted. The TNF-α and IL-1β concentrations in BALF were measured. The lungs were removed for microscopic examination and determination of W/D lung weight ratio. The other 10 animals in each group were observed for 48 h survival rate. Results Intravenous LPS significantly increased TNF-α and IL-1β concentrations in BALF and W/D lung weight ratio, decreased 48 h survival rate and induced histologic damage. Intravenous SP600125 30 mg/kg significantly attenuated the above-mentioned LPS-induced changes. Conclusion Activation of JNK is involved in the development of endotoxin-induced ALI in rats.     

氟比洛酚酯对内毒素急性肺损伤中性粒细胞肺内聚集与氧自由基损伤的抑制作用

目的 探讨氟比洛酚酯(FA)预处理对内毒素及脂多糖(LPS)所致急性肺损伤(ALI)的保护作用.方法 雄性SD大鼠40只,随机分为A1组和A2组(尾静脉注射LPS 5 mg/kg)、FA干预的F1组和F2组(注射LPS前1h,静脉注射FA 6 mg/kg)和脂微球对照组(C组),每组8只.每组给药固定容积1 ml/kg,A1、F1组和A2、F2组分别于LPS注入2、4 h后处死动物.测定动脉血氧合指数(PaO2/FiO2)、肺组织湿干质量(W/D)比值,支气管肺泡盥洗液(BALF)里中性粒细胞(PMN)百分比和乳酸脱氢酶(LDH)活性、肺髓过氧化物酶(MPO)活性,血浆及肺组织丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性,计算肺细胞凋亡指数(AI),并进行肺组织病理学检查.结果 与A1、A2组比较,F1、F2组PaO2/FiO2明显升高(P＜0.05);LDH活性和W/D比值显著下降(P＜0.05);BALF中PMN百分比、肺MPO活性显著降低(P＜0.05);血浆及肺组织MDA含鼍下降,SOD活性升高(P＜0.05);AI下降(P＜0.05),但F1与F2组间差异无统计学意义.肺组织病理学检查显示F1与F2组内毒素引起的肺损伤较A1、A2明显减轻.结论 FA预处理对ALI有保护作用,其机制可能与抑制PMN聚集、减少氧自由基生成、降低肺细胞凋亡的作用有关.     

甘草甜素对大鼠脓毒血症引起的急性肺损伤的保护作用

目的 观察甘草甜素(GL)对大鼠脓毒血症引起的急性肺损伤(ALI)的保护作用.方法 采用脂多糖(LPS)尾静脉注射诱导大鼠脓毒血症引起的AI模型.雄性SD大鼠30只,随机均分为五组:对照组(C组)、模型组(S组.静注LPS 7.5 mg/kg)、GL处理组(GL1、GL2、GL3组,分别于静注LPS 7.5 mg/kg前10 min腹腔注射GL、30、60、120 mg/kg).LPS静沣后12 h,测定各组大鼠支气管肺泡灌洗液(BALF)中自细胞总数、总蛋白的含量、肺组织髓过氧化物酶(MPO)活性和湿干重比值.并观察肺组织病理学变化.结果 与C组相比.S组BALF中白细胞计数、总蛋白含量、肺组织MPO活性和湿千重比值明显增加(P<0.05);S组肺组织切片观察见明显的炎细胞浸润、充血、水肿等.与S组相比,GL1、GL2、GL3组BALF中白细胞计数、总蛋白含量、肺组织MPO活性和肺组织湿干重比值均降低(P<0.05).病理学损伤也减轻;GL3组损伤减轻较GL1、GL2组更为明显(P<0.05).结论 GL可减轻肺泡毛细血管屏障的损伤,并随着剂量的加大损伤减轻更加明显,对脓毒血症引起的急性肺损伤具有保护作用.     

阿司匹林诱生型脂氧素A4对脂多糖诱导小鼠急性肺损伤的影响

目的 评价阿司匹林诱生型脂氧素A4 (ATL)对脂多糖(LPS)诱导小鼠急性肺损伤的影响.方法 雄性SPF级BALB/C小鼠30只,体重25～30 g,10～ 12周龄,采用随机数字表法,将其分为3组(n=10):对照组(NS组)气管内滴定生理盐水(LPS溶媒)1.5 ml/kg,1h后尾静脉注射50％无水乙醇(ATL溶媒)0.1 ml; LPS组气管内滴定LPS 3 mg/kg,1h后尾静脉注射50％无水乙醇0.1 ml; ATL组气管内滴定LPS 3 mg/kg,1h后尾静脉注射ATL 0.2 mg/kg.气管内滴定药物后24h处死,采集支气管肺泡灌洗液(BALF),计数总细胞数、多形核粒细胞比例、单个核细胞比例及其总蛋白、TNF-α、IL-6、单核细胞趋化蛋白-1(MCP-1)、IL-10的浓度;取肺组织,测定髓过氧化物酶(MPO)活性、p38丝裂原活化蛋白激酶(p38 MAPK)、c-Jun氨基末端激酶(JNK)、细胞外调节蛋白激酶(ERK1/2)的磷酸化水平,并观察肺组织病理学结果,行肺损伤评分.结果 与NS组比较,LPS组和ATL组肺损伤评分、BALF中总细胞数、多形核粒细胞比例、TNF-α、IL-6、MCP-1浓度升高,单个核粒细胞比例降低,LPS组BALF中IL-10浓度降低,总蛋白浓度、肺组织MPO活性、p38 MAPK、JNK、ERK1/2的磷酸化水平升高(P＜0.05),ATL组BALF中总蛋白、IL-10浓度、肺组织MPO活性、p38 MAPK、JNK、ERK1/2的磷酸化水平差异无统计学意义(P＞0.05);与LPS组比较,ATL组肺损伤评分、BALF中总细胞数、多形核粒细胞比例和总蛋白、TNF-α、IL-6、MCP-1浓度降低,单个核粒细胞比例和IL-10浓度升高,肺组织MPO活性、p38MAPK和JNK的磷酸化水平降低(P＜0.05),ERK1/2的磷酸化水平差异无统计学意义(P＞0.05).结论 ATL可减轻LPS诱导的小鼠急性肺损伤,其机制与抑制p38 MAPK和JNK信号通路激活有关.     

不同剂量6%羟乙基淀粉130/0.4预先给药对大鼠内毒素性急性肺损伤的影响

目的 研究不同剂量6%羟乙基淀粉130/0.4(6% HES 130/0.4)预先给药对大鼠内毒素性急性肺损伤的影响.方法 72只健康清洁级雄性SD大鼠随机分为6组(n=12),对照组(C组)经尾静脉注射生理盐水30 ml/kg;肺损伤组(L组)经尾静脉注射脂多糖(LPS)5 mg/kg;不同剂量6%HES130/0.4组分别经尾静脉注射6%HES 130/0.4 7.5 ml/kg(H1组)、15 ml/kg(H2组)和30 ml/kg(H3组),1 h后再经尾静脉注射LPS 5 mg/kg;H4组经尾静脉注射6%HES 130/0.4 30 ml/kg.各组给药速率均为0.2ml/min.注射LPS后4 h行动脉血气分析,气管插管.每组取6只大鼠,测定肺组织微血管通透性指数(PMPI);每组取6只大鼠,测定支气管肺泡灌洗液(BALF)蛋白浓度、肺组织湿/干重比(W/D)、髓过氧化物酶(MPO)活性,血清肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)、白细胞介素-10(IL-10)、丙二醛(MDA)浓度和超氧化物歧化酶(SOD)活性,观察肺组织病理学.结果 与L组比较,H2组血清TNF-α、IL-1β、MDA浓度和肺组织MPO活性降低,血清IL-10浓度和SOD活性升高,H1组IL-1β浓度降低,H1组、H2组和H3组PMPI、BALF蛋白浓度和W/D均降低(P＜0.05);与H2组比较,H1组和H3组血清TNF-α、MDA浓度和肺组织MPO活性升高,血清SOD活性、IL-10浓度降低,H3组血清IL-1β浓度升高(P＜0.05).H1组、H2组和H3组较L组肺组织损伤较轻,其中H2组损伤最轻.结论 15 ml/kg6%HES 130/0.4预先给药可减轻大鼠内毒素性急性肺损伤,其机制可能与抑制炎性因子释放、减少肺内中性粒细胞聚集和氧自由基生成、改善肺微血管通透性有关.     

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 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.     

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.     

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.     

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.     

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.     

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.