结肠憩室病患者基质胶原Ⅰ、Ⅲ代谢异常的研究

目的探讨憩室病与结肠组织中基质胶原代谢的关系。方法通过生物化学方法测定14例憩室组患者和14例对照组患者结肠组织中基质胶原的总量并分别测定基质胶原Ⅰ、Ⅲ、基质金属蛋白酶(MMP)-1和MMP-13的含量。结果两组基质胶原总量差异无显著性意义(t=0.731,P>0.05)。憩室组结肠组织基质胶原Ⅰ含量低于对照组,分别为(1.36±0.31)p·μm2和(1.61±0.34)p·μm2,两组比较,t=2.216,P<0.05。而憩室组结肠组织基质胶原Ⅲ含量高于对照组,分别为(1.62±0.33)p·μm2和(1.41±0.39)p·μm2,两组比较,t=2.075,P<0.05。基质胶原Ⅰ/Ⅲ的比值憩室组低于对照组,分别为0.83±0.25和1.14±0.28,两组比较,t=2.793,P<0.01。MMP-1憩室组和对照组分别为(4.81±0.91)p·μm2和(6.11±0.94)p·μm2,两组比较差异有显著性意义(t=2.458,P<0.05)。两组间MMP-13的量差异无显著性意义(t=0.687,P>0.05);但MMP-13并非在所有的病例中都表达,憩室组的表达率为57.14%(8/14),对照组表达率为21.43%(3/14),两组表达率比较,χ2=4.87,P<0.01。结论憩室病患者结肠组织中基质胶原Ⅰ/Ⅲ比值的降低是导致憩室病的一个重要因素,可能与MMP-1和MMP-13的异常表达有关。     

大鼠左半结肠与右半结肠吻合愈合能力的对比研究

目的 比较大鼠左半结肠和右半结肠吻合愈合的能力,为临床行结肠手术方式的选择提供理论依据.方法 将40只雄性Wistar大鼠随机分为A、B两组,每组20只.A组行右半结肠端端吻合,B组行左半结肠端端吻合.分别于术后第4天和第7天处死两组各10只动物,用免疫组化法测量吻合口组织中基质金属蛋白酶1(MMP-1)、MMP-13以及Ⅰ型胶原的表达,并同时进行组织病理学检查.结果 术后第4天,两组大鼠的左半结肠和右半结肠吻合口组织中MMP-1的表达分别为(1226±506)μm2和(732±376)μm2,两组之间比较差异有统计学意义(t=-2.54,P<0.05);两组MMP-13的表达分别为(1726±509)μm2和(1161±753)μm2,两组之间比较差异有统计学意义(t=-2.47,P<0.05);两组Ⅰ型胶原的表达分别为(199±90)μm2和(314±135)μm2,两组之间比较差异有统计学意义(t=2.30,P<0.05).术后第7天,两组大鼠的左半结肠和右半结肠吻合口组织中MMP-1的表达分别为(1264±508)μm2和(869±378)μm2,两组之间比较差异有统计学意义(t=-3.19,P<0.05);两组Ⅰ型胶原的表达分别为(228±79)μm2和(374±130)μm2,两组之间比较差异有统计学意义(t=2.61,P<0.05).结论 在结肠吻合术后,大鼠右半结肠吻合口组织中MMP-1和MMP-13的表达明显低于左半结肠,Ⅰ型胶原的表达明显高于左半结肠,提示右半结肠吻合愈合能力明显强于左半结肠.     

黄芪润肠丸治疗慢传输型便秘的临床与实验研究

为探索黄芪润肠丸治疗慢传输型便秘（STC）的机理,进行了临床与实验研究。结果显示,黄芪润肠丸（治疗组）治疗STC有效率达92．5％,优于西沙必利（对照组）（P〈0．05）。动物实验表明,小鼠排便颗粒数和炭末推进百分率治疗组均优于对照组和生理盐水组（空白组）;家兔结肠电波波幅和频率均高于正常组;治疗组小鼠结肠P物质（SP）和血管活性肠肽（VIP）物质含量均高于对照组。结果表明,由于黄芪润肠丸能通过提高结肠内SP和VIP物质含量,激活结肠电活动,加快结肠肠蠕动,故对STC有明显治疗作用。     

超声引导下前锯肌平面阻滞对乳腺癌根治术患者术后镇痛的影响

目的探讨超声引导下前锯肌平面(serratus plane,SP)阻滞对乳腺癌根治术患者术后镇痛效果的影响。方法选择择期行全麻下乳腺癌根治术患者40例,年龄45~65岁,ASAⅠ或Ⅱ级,随机分为两组:SP阻滞组(SP组)和对照组(C组),每组20例。麻醉诱导后行超声引导下术侧SP阻滞,SP组注射0.375%罗哌卡因20 ml,C组注射等容量生理盐水,术后均行舒芬太尼PCIA。于术后2、4、8、12、24h行Prince-Henry疼痛评分(PHPS)。记录术中瑞芬太尼用量及术后24h内舒芬太尼用量,24h内PCIA泵有效按压次数(D1)和实际按压次数(D2),计算D1/D2。记录患者不良反应发生情况。结果 SP组PHPS疼痛评分在术后2h[(1.3±0.4)分vs.(3.0±0.5)分]、4h[(1.4±0.5)分vs.(2.9±0.7)分]、8h[(1.7±0.6)分vs.(2.7±0.6)分]明显低于C组(P0.05)。SP组术中瑞芬太尼用量[(287±41)μg vs.(375±66)μg]及术后24h内舒芬太尼用量[(54±17)μg vs.(88±25)μg]明显少于C组,D1/D2值(0.88±0.11vs.0.56±0.17)明显高于C组(P0.05)。两组均未见其他不良反应。结论超声引导下前锯肌平面阻滞能减轻乳腺癌根治术后患者早期疼痛,增强术后镇痛效果,减少围术期阿片类药物的用量。     

糖尿病患者P物质含量与围手术期不良心血管事件的相关性研究

目的 探讨糖尿病患者血清P物质(substance P,SP)含量变化与围手术期不良心血管事件(adverse cardiovascular event,ACVE)的相关性. 方法 择期行胆囊切除术的患者44例,根据术前有无糖尿病分为两组(每组22例):糖尿病组(DM组)与对照组(C组).记录两组患者术前一般情况(年龄、性别、ASA分级、体重、血脂、肌酐等),术中血糖、心律、HR、BP、ECG、手术时间以及补液量等变化.采用ELISA法测定术前、术毕SP含量以及术前、术后24 h肌钙蛋白Ⅰ(cardiac troponin Ⅰ,cTnⅠ)含量. 结果 DM组患者胆囊切除术围手术期ACVE发生率(68.18％)较C组(36.36％)高(P＜0.05);DM组患者术前、术毕血清SP含量[(1.1 ±0.4)、(1.0±0.5) μg/L]较C组[(1.6±o.7)、(1.3±o.6)ug/L]低(P＜0.05),而术前、术后24 h血清cTnⅠ含量[(1.8±0.6)、(2.4±1.0)μg/L]较C组[(1.2±0.5)、(1.4±0.6)μg/L]高(P＜0.05);根据围手术期有无发生ACVE进行分类,发生ACVE患者SP含量[(1.0±0.5)μg/L]较未发生ACVE患者(non-ACVE,NACVE)SP含量[(1.4±0.7)μg/L]低(P＜0.05).结论 糖尿病患者血清SP含量降低可能与患者围手术期ACVE的发生率有关.     

先天性巨结肠突触素和 Cajal间质细胞及肠电图的同步研究

目的探讨突触素( SY)和 Cajal间质细胞( ICCs)在先天性巨结肠( HD)中的变化和临床意义.方法应用免疫组织化学方法和病理显微镜图像分析系统,计算 48例 HD患儿和 10例正常对照儿 SY和 ICCs阳性染色区域面积并进行对比.结果 HD患儿扩张段内 SY和 ICCs阳性面积与对照组比较,差异无统计学意义 [(3.27± 1.05) vs.(3.53± 0.89);(2.09± 1.28)vs.(2.22± 1.31);P >0.05],而狭窄段肠壁内 SY和 ICCs镜下阳性面积均比对照组明显减少 [(1.34± 0.97)vs.(3.53± 0.89);(1.41± 0.85)vs.(2.22± 1.31);P< 0.01]. HD病变肠段肠电图出现异常波型.结论突触素和 Cajal间质细胞的分布异常是 HD的重要病理改变,这种改变导致了病变肠管慢波节律形成和兴奋传导的异常,引起或加重了 HD的动力障碍.     

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.     

急性胰腺炎后胰腺内分泌变化临床研究

目的:观察研究急性胰腺炎后胰腺内分泌变化。方法:选取既往无糖尿病病史的急性胰腺炎住院患者60例为急性胰腺炎组,既往无糖尿病病史正常体检者30人为对照组。测定入院时、入院次日晨空腹、入院后第3 d晨空腹、入院后第7 d晨空腹血糖、胰岛素和C肽,比较两组结果。结果:急性胰腺炎组血糖在入院时[(7.2±1.4)mmol/L]、24 h[(7.3±2.3)mmol/L]、3 d[(9.4±1.6)mmol/L]较对照组[(4.3±1.8)mmol/L]升高,具有统计学意义,入院后7 d血糖([4.5±1.2)mmol/L]较对照组无明显升高。急性胰腺炎组血清胰岛素在入院后24 h([10.0±3.0)μIU/m L]、3 d([9.5±2.6)μIU/m L]较对照组[(11.4±0.6)μIU/m L]降低,具有统计学意义(P0.05),入院时[(11.8±2.7)μIU/m L]及入院后7 d[(11.9±2.7)μIU/m L]血清胰岛素较对照组无明显变化。急性胰腺炎组血清C肽在入院后24 h[(1.3±0.6)ng/m L]、3 d[(1.3±0.3)ng/m L]较对照组[(1.5±0.5)ng/m L]降低,入院时[(1.4±0.3)ng/m L]及入院后7 d[(1.5±0.3)ng/m L]血清C肽较对照组无明显变化。急性胰腺炎组血糖值随着发病时间延长呈现先升后降趋势,发病后7 d血糖基本恢复。血清胰岛素及C肽值则呈现先降后升趋势。结论:急性胰腺炎患者随着病情发展血糖先升后降,胰岛素及C肽先降后升,提示急性胰腺炎患者胰腺内分泌功能失调。     

术中结肠灌洗在治疗左半结肠癌性梗阻时肠道细菌学的研究

目的探讨术中结肠灌洗一期切除吻合治疗急性左半结肠癌并完全性肠梗阻的可行性。方法对18例左半结肠癌并急性肠梗阻的患者采用术中结肠灌洗并行一期肿瘤切除吻合,并与12例左半结肠癌无梗阻患者的肠内容物和肠黏膜细菌变化情况进行对比。结果肠梗阻患者近端肠内容物和肠黏膜的细菌数明显高于无梗阻组,肠内容物细菌数分别为(107.63±59.58)×106cfu/L和(13.86±3.19)×106cfu/L,两组相比,P=0.021;肠黏膜细菌数分别为(7770.06±2433.95)cfu/cm2和(334.83±288.39)cfu/cm2,两组相比,P=0.014。经术中结肠灌洗后,近端肠内容物细菌数梗阻组比无梗阻组明显减少,分别为(1.72±0.21)×106cfu/L与(13.86±3.19)×106cfu/L,两组相比,P=0.004;近端肠黏膜细菌数梗阻组也比无梗阻组明显减少,分别为(13.22±8.85)cfu/cm2与(334.83±28.84)cfu/cm2,两组相比,P=0.013。术前应用抗生素与否对肠道细菌无明显影响(P>0.05)。结论左半结肠癌并完全性肠梗阻经术中结肠灌洗,能使肠道内细菌数明显降低而达到或低于无梗阻患者肠道内的细菌数,因而一期切除吻合是可行的。     

精准肝切除治疗肝脏肿瘤的疗效评价

目的评价精准肝切除术治疗肝脏肿瘤的近期疗效。方法将近2年内收治的143例肝脏肿瘤患者采用前瞻性、非随机对照临床试验的方法行精准肝切除84例(精准组)和行传统肝切除59例(对照组),比较两组手术后的近期效果。精准组采用肝段或肝叶切除方式,术中以半肝阻断或不阻断入肝血流为主。传统组采用肝门血流全阻断下大块钳夹缝扎法。结果精准组手术切除时间[(134±86)min]显著长于对照组[(71±52)min](P<0.01)。两组术中出血量分别为(274±186)mL和(340±220)mL,组间无统计学差异(P=0.055)。术后精准组当日引流量[(175±86)mL]显著少于对照组[(311±98)mL](P<0.01)。精准组术后3 d内血清ALT,AST,总胆红素,C反应蛋白峰值依次分别为(283.9±218.4)U/L,(215.5±171.3)U/L,(27.7±15.9)μmol/L,(35.4±17.3)mg/L,对照组分别为(754.5±273.0)U/L,(692.1±216.7)U/L,(46.3±20.1)μmol/L和(79.5±31.8)mg/L,两组间上述指标差异有统计学意义(均P<0.01...     

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.