自身免疫法制作大鼠慢性非细菌性前列腺炎模型的周期

目的 探讨应用前列腺组织蛋白提纯液(PTHS)辅以弗氏完全佐剂(FCA)和百白破疫苗(PDT),成功建立慢性非细菌性前列腺炎(CNP)大鼠模型所需的时间周期.方法 取4个月龄雄性SD大鼠10只,麻醉处死后在无菌条件下剖腹取前列腺组织,高速离心制作PTHS,用微量紫外分光光度计测定前列腺组织蛋白含量,再以0.1 mol/LpH7.4的PBS缓冲液调节蛋白浓度至20 mg/ml.再将PTHS与FCA等体积混合成混悬液.另取2个月龄SD大鼠48只,随机分为6组,每组8只.其中5组为实验组(1周组、2周组、4周组、6周组、8周组),每只大鼠皮内多点注射PTHS与FCA的混悬液1.0ml,同时腹腔注射PDT 0.5ml,分别于1、2、4、6、8周处死后取前列腺组织观察大体形态和光镜病理特征.另1组为对照组,同法注射等量生理盐水,并于第8周处死后观察前列腺特征.结果 对照组大鼠前列腺大体形态正常,光镜下未见炎症表现;1周组大鼠前列腺也无明显炎症表现;2周组大鼠前列腺组织轻度充血水肿,腺体周围可见散在的淋巴细胞浸润;4周组大鼠前列腺结构出现轻中度破坏,间质、腺体内和腺体周围均出现较多的淋巴细胞浸润;6周组大鼠前列腺结构破坏严重,间质、腺体内和腺体周围有弥漫的淋巴样组织增生和淋巴、单核细胞等慢性炎细胞浸润,提示建模成功;8周组大鼠炎症情况与6周组大鼠类似.结论 应用同源大鼠的PTHS辅以双重免疫佐剂(FCA和PDT)经过6周的时间可以成功建立CNP大鼠模型.     

糖尿病性勃起功能障碍大鼠中低睾酮水平对阴茎海绵体平滑肌的影响

目的 观察糖尿病性勃起功能障碍(DMED)大鼠的睾酮水平变化对其阴茎海绵体平滑肌组织和超微结构的影响.方法 将3个月龄雄性Wistar大鼠20只随机等分为两组:正常对照组和DMED组,行放射免疫法测定其血清睾酮浓度和masson染色观察阴茎海绵体平滑肌(CCSM)密度以及通过透射电镜观察海绵体平滑肌细胞的超微结构.结果 DMED组大鼠的血清睾酮水平(17.445 ±2.540) nmol/L较正常组(338.457±63.802) nmol/L明显下降(P＜0.01);同时DMED组大鼠CCSM密度(5.640±0.597)％较正常对照组(19.890±1.957)％亦明显减少(P＜0.01),透射电镜下还观察到DMED组大鼠阴茎CSMC的核浆比增大,高尔基复合体明显肥大以及线粒体水肿.结论 睾酮水平下降可能导致DMED大鼠阴茎海绵体平滑肌发生病理变化.     

血管活性肠多肽调控大鼠阴茎勃起的年龄及雄激素相关性研究

目的建立不同月龄及不同雄激素水平的SD大鼠模型,评价血管活性肠多肽（VIP）调控不同模型大鼠阴茎勃起的作用。方法 SD雄性大鼠80只随机等分为4组：A组（对照组）;B组（去势组）,行双侧睾丸切除;C组（老龄组）,普通饲养16个月;D组（去势老龄组）,去势术后饲养16个月。A和B组1月后测勃起功能;C和D组16个月后测勃起功能。电刺激海绵体神经时海绵体内压力（ICP）的最大值与对应平均动脉压（MAP）的比值表示勃起功能,记为Ratio。海绵体注射VIP前、后大鼠勃起功能分别以b-Ratio和m-Ratio表示。m-Ratio与b-Ratio的比值（记为mR/bR）表示VIP对勃起功能的影响程度。留取血清,ELISA方法检测血清睾酮浓度。结果 A、B、C和D组的b-Ratio（%）分别为69.8±7.0、36.8±5.4、53.2±8.5、33.2±6.3;m-Ratio（%）分别为73.0±8.7、63.4±9.6、79.7±10.8、67.0±11.8;mR/bR分别为1.05±0.03、1.72±0.08、1.56±0.29、2.06±0.44。后3组与A组比较勃起功能增加程度明显（P均〈0.01）。A、B、C和D组的血清睾酮浓度（ng/mL）分别为1.542±0.131、0.438±0.096、0.840±0.153、0.416±0.101,后3组均明显低于A组（P均〈0.01）。结论年龄增长和雄激素水平降低导致大鼠勃起功能下降,年龄对勃起功能的影响可能基于雄激素水平的变化;VIP对阴茎勃起的调控作用与年龄增长呈正相关,与雄激素水平负相关。     

大鼠慢性非细菌性前列腺炎模型的建立及病理组织学特征

目的 建立大鼠慢性非细菌性前列腺炎(chronic nonbacterial prostatitis,CNP)模型,探讨大鼠CNP的病理组织学特征. 方法 4只SD大鼠,处死后在无菌条件下取前列腺组织,制作前列腺组织蛋白提纯液(prostate tissue homogenate supernate,PTHS).另取20只SD大鼠分为对照组和模型组,每组各10只.模型组于第0、30天皮内多点注射PTHS(20 mg/ml)与弗氏完全佐剂(Freund's complete adjuvant,FCA)的等体积混悬液1.0 ml,同时腹腔注射百白破疫苗(pertussis-diphtheria-tetanus,PDT)0.5 ml;对照组同法注射等量生理盐水.第45天处死后无菌条件下取前列腺组织,观察前列腺的大体形态和光镜病理特征.确认建模成功后同法建立80只CNP大鼠,分为雄激素高剂量组(H组)、中剂量组(M组)、低剂量组(L组)和对照组(C组),每组各20只.H、M、L组分别应用4、2、1 mg/ml的丙酸睾酮,C组应用无菌花生油,皮下注射,0.5 ml/次,隔日1次.每组均再分为4个亚组,每亚组各5只,分别用药1、2、4、6周.用药期满后观察前列腺的大体形态和光镜病理特征. 结果 第45天模型组前列腺大体形态可见组织严重充血水肿,与周围组织粘连,前列腺包膜不完整.光镜下见前列腺组织结构破坏,间质和腺体内有弥漫的淋巴样组织增生和慢性炎症细胞浸润.对照组无上述炎症表现.应用丙酸睾酮后,H、M、L组前列腺炎症出现不同程度的减轻,破坏的腺体和间质修复再生,淋巴样组织增生减少,慢性炎症细胞浸润的部位、范围和数量减少,且应用丙酸睾酮浓度越大、时间越长,炎症程度减轻越明显.C组炎症程度无改善.根据病理检查结果总结CNP大鼠前列腺的病理组织学特征,包括炎症部位、炎症范围和炎症分级3个方面.炎症部位:①炎症位于腺体,指炎症细胞浸润位于导管上皮、腺泡上皮和(或)腺腔内;②炎症位于腺体周围,指炎症细胞浸润间质,环绕腺管周围;③炎症位于间质,指炎症细胞浸润间质,不环绕腺管周围.根据炎症细胞浸润组织的面积确定炎症范围:①＜10％为局灶性;②10％ ～50％为多灶性;③＞50％为弥漫性.炎症分级:Ⅰ级指炎症细胞分散,炎症细胞数1 ～ 10个/HP;Ⅱ级指炎症细胞聚集,无腺体上皮组织破坏或淋巴样小结/滤泡形成,炎症细胞数11～20个/HP;Ⅲ级指炎症细胞聚集,部分腺体上皮组织破坏或淋巴样小结/滤泡形成,炎症细胞数＞20个/HP;Ⅳ级指炎症细胞聚集,大量腺体上皮组织破坏或淋巴样小结/滤泡形成,炎症细胞数满视野. 结论 应用同源大鼠的PTHS辅以FCA和PDT可以建立大鼠CNP模型.根据炎症的部位、范围和分级来评价大鼠CNP的病理组织学特征有利于CNP发病机制和治疗的研究.     

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。     

电刺激阴茎海绵体神经测定大鼠勃起功能的方法探讨

目的:探讨电刺激阴茎海绵体神经(CN)测定大鼠勃起功能的方法。方法:选择4月龄雄性SD大鼠20只,体质量(425±25)g。左颈总动脉内插管,直接法持续监测大鼠平均动脉压(MAP);左侧海绵体内插管测定阴茎海绵体内压(ICP);前列腺右侧叶前外侧表面暴露右侧CN,通过电刺激CN诱发阴茎勃起。电刺激参数为:5V,2ms,25Hz,每次刺激持续1min,间隔5min重复电刺激,共刺激3次。电刺激CN前的(ICP/MAP)×100(rR)代表阴茎海绵体的静息状态;电刺激CN后的(ICP最大值/MAP)×100(bR)代表阴茎海绵体的勃起状态或大鼠的基础勃起功能;bR/rR代表阴茎勃起后ICP的增高程度。结果:电刺激CN使ICP明显升高,MAP变化不大,表明电刺激可有效诱发勃起。ICP、MAP、rR、bR、bR/rR等各项指标3次重复测定之间的差异均无统计学意义(均P>0.05),表明电刺激法结果稳定。rR、bR和bR/rR总的平均值分别为(12.00±2.62)%、(67.68±11.28)%和(5.85±1.80)。结论:电刺激阴茎CN测定大鼠勃起功能的方法稳定易重复,能够客观准确地评估阴茎的勃起程度,是研究阴茎勃起功能的重要技术,值得在国内推广。     

α-黑素细胞刺激素对慢性非细菌性前列腺炎大鼠HMGB1表达的影响

目的 探讨HMGB1在大鼠慢性非细菌性前列腺炎(CNP)发病中的作用和α-MSH治疗大鼠CNP的机制.方法 将30只大鼠随机分为正常对照组,CNP模型组和CNP+α-MSH治疗组,每组10只.H.E染色,光镜下观察各组前列腺组织的病理学表现,采用免疫组化的方法 检测HMGB1、TNF-α和IL-10在各组大鼠前列腺中的表达.Western blot检测HMGB1、TNF-α和IL-10定量变化的情况.结果 (1)所建立的大鼠模型的病理和病理生理学的改变符合CNP的特点;(2)HMGBl和TNF-α在模型组的表达均显著高于正常对照组(P<0.05);(3)治疗组大鼠的前列腺组织中HMGB1和TNF-α表达量显著降低(P<0.05);(4)治疗组大鼠IL-10的表达明显高于模型组(P<0.05).结论 HMGB1可能参与了大鼠慢性非细菌性前列腺炎的发病过程,α-MSH具有抑制炎症因子表达和促进抗炎性细胞因子IL-10表达的作用.     

人胰岛素样生长因子-1基因治疗老龄大鼠阴茎勃起功能障碍的研究

目的探讨阴茎海绵体内注射胰岛素样生长因子1(hIGF-1)基因提高老年性大鼠阴茎勃起功能的可能性. 方法9月龄＞500g SD大鼠35只随机分为3组,注射PCDB-hIGF-1组15只,注射PCDB组10只,空白对照组10只.注射后1～2 d测量大鼠海绵体内压(ICP),收集大鼠阴茎海绵体组织,Trizol方法提取总RNA,RT-PCR检测hIGF-1基因mRNA的表达,免疫组化检测hIGF-1蛋白表达.结果注射PCDB-hIGF-1组大鼠ICP(149±10)高于注射PCDB空质粒组(93±11)和对照组(89±12),差异有统计学意义(P＜0.05);RT-PCR检测注射PCDB-hIGF-1组检测到392 bp的特异性条带,注射PCDB组和对照组未检测到特异性条带;注射PCDB-hIGF-1组免疫组化均可见hIGF-1蛋白的阳性表达.结论hIGF-1基因在大鼠阴茎海绵体中有大量表达,PCDB质粒介导的海绵体内hIGF-1基因注射可部分恢复老龄大鼠的勃起功能.     

非细菌性前列腺炎动物模型的建立及环氧合酶-2测定

目的 探讨非细菌性前列腺炎的动物模型建立方法及慢性非细菌性前列腺炎(CNP)的发病机制.方法 成年雄性SD大鼠72只,随机分为3组,每组24只:实验组用大鼠膀胱穿刺抽出尿液前列腺内注射建立前列腺炎模型,对照组用无菌生理盐水前列腺内注射,假手术组大鼠前列腺仅做针刺处理.模型建立后第1、3、7天分别处死大鼠8只观察前列腺大体形态,HE染色光镜观察,免疫组织化学法检测环氧合酶-2(COX-2)在模型中的表达.结果 实验组前列腺炎症变化较对照组及及假手术组明显,第1、3、7天随着时间延长实验组前列腺内炎症程度渐好转.免疫组织化学显示实验组COX-2染色强度为87.5%,较对照组(25.0%)及假手术组(12.5%)明显增强(P＜0.05);随着时间延长C0X-2染色强度有明显下降(P＜0.05).结论 尿液刺激导致前列腺内COX-2升高可能与CNP的发病机制有密切关系.     

补肾助阳方对植物雌激素致勃起功能下降干预的实验研究

目的:研究补肾助阳方(养精胶囊)对大鼠阴茎勃起功能的影响机制。方法:成年雄性SD大鼠56只,随机分为7组,分别为空白对照组、大豆黄酮组、十一酸睾酮组、西地那非组及养精胶囊(高/中/低)剂量组。空白对照组给予生理盐水灌胃,其余各组100 mg/(kg·d)大豆黄酮灌胃30d。随后各实验组在给予大豆黄酮灌胃的同时,养精胶囊(高/中/低)剂量组分别给予1.26、0.63、0.315 mg/k/d剂量的养精胶囊组方,十一酸睾酮组给予4mg/(kg·d)剂量的十一酸睾酮,西地那非组给予2.5 mg/(kg·d)剂量的西地那非。分别在实验第0、30、60天观察各组大鼠阿扑吗啡诱导的自发勃起反应,记录勃起次数及勃起潜伏期,测定大鼠血清睾酮、黄体生成素水平,并观察大鼠阴茎海绵体组织切片。结果:实验第30天时,所有实验组大鼠阿扑吗啡诱导的勃起次数明显下降,勃起潜伏期延长,有统计学意义(P0.05)。第60天时,大豆黄酮组(1.39±0.42 vs 2.67±0.33)和大豆黄酮及低剂量养精胶囊组(1.33±0.49 vs 2.83±0.61)大鼠阿扑吗啡诱导的勃起次数明显下降(P0.05);阿扑吗啡诱导的大鼠勃起潜伏期只有大豆黄酮组[(16.33±3.11)min vs(8.50±0.93)min]和大豆黄酮及低剂量养精胶囊组[(15.50±3.21)min vs(8.63±1.54)min]明显延长(P0.05),其余各组变化不明显。实验第30天时,所有实验组大鼠血清睾酮、黄体生成素均有显著下降(P0.05)。实验第60d时,大豆黄酮组[(5.34±0.89)ng/ml vs(1.24±0.30)ng/ml]和大豆黄酮及低剂量养精胶囊组[(5.28±1.12)ng/ml vs(2.07±0.76)ng/ml]血清睾酮变化有统计学意义(P0.05)。两组的黄体生成素由(3.62±0.37)ng/ml、(3.79±0.28)ng/ml变为(2.09±0.12)ng/ml、(2.17±0.33)ng/ml,显著下降(P0.05)。切片结果显示对照组大鼠阴茎海绵体内海绵窦数目多,血管清晰可见。大豆黄酮加睾酮组、大豆黄酮加西地那非组和大豆黄酮加中、高剂量养精胶囊组大鼠海绵体与正常对照组相比,海绵窦数目减少。大豆黄酮组和大豆黄酮加低剂量养精胶囊组大鼠海绵体内海绵窦明显减少,血管少见。结论:使用高剂量养精胶囊治疗后,大鼠阴茎勃起功能恢复,对由植物雌激素引起的勃起功能下降有良好疗效。     

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.