Spontaneous hemolytic activity of rat alveolar lining material

During assays of the complement hemolytic activity in lavage fluids (LF) from humans and various laboratory animals (hamsters, rabbits, rats, guinea pigs), we have observed that rat bronchoalveolar lavages had a spontaneous, complement-independent, hemolytic activity to sheep red blood cells (SRBC). Rat lavage fluids were able to lyse sheep and autologous red blood cells at 2°C as well as at 37°C. Together with these observations, the inverse relationship that existed between the LF hemolytic activity and the calcium concentration in the incubation medium suggested that lysis could be due to the presence of large amounts of lysophospholipids in rat lavage fluid. However, thin layer chromatography did not reveal any abnormal amount in lysoderivative, whereas the free fatty acid (FFA) content was very high. Pure palmitic acid, at a concentration similar to that observed in LF from rat, was able to lyse SRBC (8.5μg lyzed 50% of 10⁸ SRBC); its lytic activity decreased when Ca⁺⁺ or bovine serum albumin was added to the incubation mixture. FFA through their detergent effect, appear to account for the hemolytic activity of the rat alveolar lining material.     

Effect of calcium on the hemolytic activity of Stichodactyla helianthus toxin sticholysin II on human erythrocytes

Sticholysin II (St II) is a toxin from the sea anemona Stichodactyla helianthus that produces erythrocytes lysis at low concentration and its activity depends on the presence of calcium. Calcium may act modifying toxin interaction with erythrocyte membranes or activating cellular processes which may result in a modified St II lytic action. In this study we are reporting that, in the presence of external K⁺, extracellular calcium decreased St II activity on erythrocytes. On the other hand an increase of intracellular calcium promotes Sty II lytic activity. The effect of intracellular calcium was specifically studied in relation to membrane lipid translocation elicited by scramblases and how this action influence St II lytic activity on erythrocytes. We used 0.5 mmol/L calcium and 10 mmol/L A23187, as calcium ionophore, for scramblases activation and found increased St II activity associated to increase of intracellular calcium. N-ethyl maleimide (activator) and 4,4′-diisothiocyanatostilbene-2,2′-disulfonate (inhibitor) were used as scramblases modulators in the assays which produced an increase and a decrease of the calcium effect, respectively. Results reported suggest an improved St II membrane pore-forming capacity promoted by intracellular calcium associated to membrane phospholipids translocation.     

血清溶血程度对21项生化指标测定的影响

目的观察血清不同的溶血程度对21项生化指标测定的影响。方法用Bayer120全自动血常规分析仪测定血清血红蛋白（Hb）含量作为判定溶血的程度;采用全自动生化分析仪及电解质仪检测40例门诊随机病人,观察在不溶血和溶血程度在Hb=3．0g／L与Hb：6．0g／L时的21项血清生化指标的酶活力变化。结果在Hb=3．0g／L时的溶血程度下AST,LDH,CK,CK-MB,α-HBDH,TP,K值显著升高（P〈0．01,TP为P〈0．05）,并随着溶血程度加重（Hb=6．0g／L时）酶活力比Hb=3．0g／L时又明显升高（P〈0．01）。在Hb=3．0g／L的溶血程度下,GLU,Phos则显著降低（P〈0．01）,并随溶血加重（Hb=6．0g／L）时,检测值降低更明显（P〈0．01）;Cr在Hb=3．0g／L时差异无统计学意义（P〉0．05）,但当溶血程度加重（Hb=6．0g／L）时酶活力则显著下降（P〈0．05）。其余酶活力指标在不同溶血程度下则差异无统计学意义（P〉0．05）。结论不同程度的溶血主要对21项生化指标中心肌酶谱5项,TP,K,GLU,Phos,Cr的检测有明显影响,其余指标差异不显著。     

正交试验法优选溶血效果的研究

目的以血凝块溶解为指标,研究污物排除配方,确定具有最佳溶血效果的试剂组合,利于检验仪器管道清洗。方法通过预实验在众多试剂中筛选出符合实验要求的试剂,利用正交试验法优选出溶血效果最佳的试剂组合,分析各因素对溶血效果的影响。结果正交试验法确定有机溶剂5%、中性表面活性剂0.5%、胰蛋白酶0.1%、脂肪酶0.2%为最佳复合配方;各因素对溶血效果的影响如下：有机溶剂〉胰蛋白酶〉中性表面活性剂〉脂肪酶。结论确定的最佳组合试剂溶血效果佳,有利于检验仪器管道清洗。     

Biocompatibility Assessment of the First Generation PediaFlow Pediatric Ventricular Assist Device

The PediaFlow pediatric ventricular assist device is a miniature magnetically levitated mixed flow pump under development for circulatory support of newborns and infants (3–15 kg) with a targeted flow range of 0.3–1.5 L/min. The first generation design of the PediaFlow (PF1) was manufactured with a weight of approximately 100 g, priming volume less than 2 mL, length of 51 mm, outer diameter of 28 mm, and with 5‐mm blood ports. PF1 was evaluated in an in vitro flow loop for 6 h and implanted in ovines for three chronic experiments of 6, 17, and 10 days. In the in vitro test, normalized index of hemolysis was 0.0087 ± 0.0024 g/100L. Hemodynamic performance and blood biocompatibility of PF1 were characterized in vivo by measurements of plasma free hemoglobin, plasma fibrinogen, total plasma protein, and with novel flow cytometric assays to quantify circulating activated ovine platelets. The mean plasma free hemoglobin values for the three chronic studies were 4.6 ± 2.7, 13.3 ± 7.9, and 8.8 ± 3.3 mg/dL, respectively. Platelet activation was low for portions of several studies but consistently rose along with observed animal and pump complications. The PF1 prototype generated promising results in terms of low hemolysis and platelet activation in the absence of complications. Hemodynamic results validated the magnetic bearing design and provided the platform for design iterations to meet the objective of providing circulatory support for young children with exceptional biocompatibility.     

人凝血因子Ⅷ的溶血性和血管刺激性研究

目的  评估人凝血因子Ⅷ（human coagulation factor Ⅷ,hFⅧ）的溶血性和血管刺激性。方法  以家兔为实验动物,对hFⅧ进行体外溶血和体内血管刺激性实验。结果  在3 h体外实验期间未观察到兔红细胞发生溶血和凝聚。当以40 IU/kg 剂量的hFⅧ对家兔进行静脉注射时,未观察到家兔耳缘静脉的血管刺激性反应。结论  静脉注射推荐剂量的hFⅧ不会发生溶血和血管刺激反应。     

溶血对乙型肝炎表面抗原检测的影响

目的分析溶血对乙型肝炎表面抗原检测的影响。方法采用金标法检测乙型肝炎表面抗原（HBsAg）。结果溶血标本采用金标法检测HBsAg易产生假阳性或假阴性。结论溶血影响乙型肝炎表面抗原的测定结果 ,溶血标本一般不宜做乙型肝炎表面抗原的检测。