Effects of a leucocyte depleting arterial line filter on perioperative proteolytic enzyme and oxygen free radical release in patients undergoing aortocoronary bypass surgery

BACKGROUND: Proteolytic enzymes and oxygen free radicals released from activated leucocytes contribute significantly to the organ dysfunction associated with cardiopulmonary bypass. Leucocyte depletion during extracorporeal circulation should reduce the release of these toxic compounds and thereby improve postbypass myocardial and pulmonary function. Recently, a leucocyte-specific arterial line filter to achieve leucocyte depletion during clinical perfusion has become commercially available. The aim of this study, therefore, was to evaluate the influence of the leucocyte depleting arterial line filter on proteolytic enzyme release, oxygen free radical release and postbypass pulmonary and myocardial function in patients undergoing bypass surgery. METHODS: Forty patients undergoing elective aortocoronary bypass surgery were included into this prospective, randomized clinical study, 20 in the leucocyte depletion (LG-6 group, leucocyte-specific arterial line filter) and 20 in the control group (AV-6 group, standard arterial line filter). White cell count, differential white cell count, plasma elastase concentration, plasma malondialdehyde concentration and C-reactive protein were determined before, twice during and immediately after cardiopulmonary bypass, at the end of surgery and 6 and 20 h thereafter. RESULTS: White cell count, differential white cell count, malondialdehyde and C-reactive protein were not significantly different between LG-6 and control patients. Plasma elastase concentrations were significantly (P < or = 0.03) higher during and immediately after extracorporeal circulation in LG-6 group patients. Need for inotropic support, arterial pO2 after extracorporeal circulation and perioperative CK MB mass and troponin I release were not different between the two groups of patients. CONCLUSION: The use of a leucocyte depleting arterial line filter is associated with an increased release of the proteolytic enzyme elastase, but does not reliably and consistently achieve effective leucocyte depletion during clinical perfusion. In contrast to previous studies, we could not demonstrate any significant difference in postbypass pulmonary or myocardial function between patients perfused with the leucocyte-specific arterial line filter and control patients. Our data do not support the routine use of a leucocyte depleting arterial line filter during clinical perfusion in patients undergoing elective aortocoronary bypass surgery.     

模拟飞行缺氧与吸氧对小鼠脏器自由基代谢的影响

目的 观察了两种模拟飞行条件（１５００ｍ轻度低压缺氧和５５００ｍ中度低压吸氧重复暴露下小鼠多脏器自由基代谢变化的特点。方法 昆明种小鼠６０只,随机分为６组（ｎ＝１０）进行缺氧与吸氧实验,实验完毕后,取小鼠尾血做血常规检查。次日,将小鼠断头处死,取脑、心、肺、肝、肾制备匀浆,测定丙二醛（ＭＤＡ）含量和超氧化物歧化酶（ＳＯＤ）活性。结果 １５００ｍ轻度低压缺氧重复暴露８ｗｋ使肺ＭＤＡ含量显著增高,提示     

Ultrasound Densitometric Analysis: Comparison Between an Online Digital Acquisition Acoustic Program and an Offline Analog Program

Videodensitometric analysis of myocardial contrast echocardiography is traditionally performed off line. Recently, an online contrast ultrasound analysis system, Acoustic Densitometry (Hewlett-Packard), was introduced. We compared pixel intensities acquired with Acoustic Densitometry to pixel intensities derived from videodensitometry. A tissue phantom was imaged in phase I using three transducer frequencies (2.5, 3.5, and 5.0 MHz). In phase II, an in vitro flowing tube model with various concentrations of Albunex® was imaged at two flow rates, 0.6 and 1.2 m/sec, and at two transducer frequencies, 2.5 and 3.5 MHz. The relationship between pixel intensities yielded by the two systems for identical ultrasound signals was determined with linear regression. Intensities derived with Acoustic Densitometry strongly correlated with those derived from the offline videodensitometry system. The intensities were related by a predictive multiplicative factor based on display characteristics of the two systems. These results suggest that semiquantitative, online perfusion analysis with Acoustic Densitometry is as sensitive as analysis offline with videodensitometry.     

Effects of dihydroergotamine (DHE) on blood flow and metabolism in the underperfused myocardium in anaesthetized dogs

Summary The study was carried out in 13 mongrel dogs. Regional myocardial blood flow was measured using radiolabelled microspheres. Lactate, H⁺-ions, and O₂ content were measured in arterial and local venous blood. Partial occlusion of the ramus circumflexus (LCX) led to a decrease in left ventricular dp/dt max, systemic arterial pressure, and a marked release of lactate from the underperfused myocardium. With DHE (2 g/kg infused within 5 min, 8 dogs), a slight decrease in heart rate, left ventricular dp/dt max, LCX-resistance and a small increase in femoral and total peripheral resistance as well as in arterial and left and right atrial pressure was observed. In the normally perfused and in the underperfused part of the left ventricle microsphere assessed blood flow was unchanged or slightly elevated with DHE. Lactate release from the underperfused myocardium was markedly reduced. None of the DHE-induced effects on hemodynamic and metabolic parameters were observed in control experiments with infusion of 0.9% NaCl (5 ml). The results indicate that DHE leads to an amelioration of impaired metabolism in the underperfused myocardium and exerts no vasoconstriction in this area.This work was supported by the Fonds zur Förderung der wissenschaftlichen Forschung.     

Combined negative inotropic effects of calcium entry blockers and isoflurane on canine isolated heart muscles

The combined negative inotropic effects of isoflurane and calcium entry blockers (verapamil, diltiazem, nifedipine, nicardipine) were studied utilizing isolated heart preparations of ventricular muscles from dogs. All of these calcium entry blockers exerted dose-dependent decreases in maximal velocity of shortening (Vmax), maximal developed isometric force (Fm), and the maximal first derivative of Fm (maximal dF/dt). Dose-dependent decreases of these variables of muscle mechanics were augmented in isoflurane-depressed myocardium. At equimolar concentrations, direct myocardial depression was demonstrated in the following order of severity: nifedipine > diltiazem = verapamil > nicardipine. Percent depressions of Vmax, Fm and maximal dF/dt were significantly greater in muscles when calcium entry blockers were combined with 1MAC isoflurane than in muscles of calcium entry blockers alone. These data suggest that the negative inotropic effects of verapamil, diltiazem, nifedipine, and nicardipine were potentiated by isoflurane.(Nakata F, Kemmotsu O: Combined negative inotropic effects of calcium entry blockers and isoflurane on canine isolated heart muscles. J Anesth 5: 48–55, 1991)     

川芎嗪对大鼠缺血心肌细胞核钙转运异常的影响

目的 :观察大鼠缺血心肌细胞核钙转运功能的变化及川芎嗪的作用。方法 :将Wistar大鼠随机分成对照组、缺血组和川芎嗪保护组。采用皮下注射异丙肾上腺素 (ISP,5mg·kg- 1 ) ,2 4h后再注射相同剂量一次 ,造成心肌缺血模型。超速离心纯化细胞核 ,酶学法鉴定核纯度和测定核膜Ca2 + ATPase活性 ,同位素法观测核钙的摄取。结果 :缺血组心肌细胞核膜Ca2 + ATPase活性较对照组下降 2 1 .4% (P<0 .0 1 ) ,4 5Ca2 + 摄取率也呈显著性降低 ,其最大反应速度 (Vmax)降低 48.5 % ,细胞核膜Ca2 + 依赖性ATP酶的Vmax 降低 3 4.1 % ,Km 值降低 42 .2 % (P <0 .0 1 ) ,川芎嗪保护组心肌细胞核Ca2 + ATP酶活性及核4 5Ca2 + 摄取率较缺血组均有显著性升高 ,且有剂量依赖关系。结论 :川芎嗪对ISP所致的缺血心肌细胞核钙转运功能下降有拮抗作用     

Puerarin blocks Na~+ current in rat ventricular myocytes

AIM: To study the effect of puerarin (Pue) on Na~+ channel in rat ventricular myocytes. METHODS: Whole-cell patch-clamp technique was applied on isolated cardiomyocytes from rats. RESULTS: Pue inhibited cardiac I_(Na) in a positive rate-dependent and dose-dependent manner, with an IC_(50) of 349 μmol/L. The kinetics of blockage of cardiac sodium channel by Pue resembled the ClassIa/Ic of antiarrhythmic agents. Pue 300 μmol/L did not alter the shape of the I-V curve of I_(Na), but markedly shifted the steady-state inactivation curve of I_(Na) towards more negative potential by 15.9 mV, and postponed the recovery of I_(Na) inactivation state from (21.9±1.6) ms to (54.4±3.4) ms (P<0.01 ). It demonstrated that the steady state of inactivation was affected by Pue significantly. CONCLUSION: Pue protected ventricular myocytes against cardiac damage and arrhythmias by inhibiting recovery from inactivation of cardiac Na~+ channels.     

PATHOLOGY OF LONG-CHAIN 3-HYDROXYACYL-COA DEHYDROGENASE DEFICIENCY CAUSED BY THE G1528C MUTATION

Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency is a recently discovered disorder affecting the mitochondrial-oxidation of fatty acids. There have been few reports of the pathologic findings in-oxidation defects. We examined pathologic specimens from 16 patients with this disorder (11 patients were homozygous for the common mutation G1528C, 5 patients were siblings with a similar clinical presentation). Autopsies were performed on all 15 patients who died, and liver biopsy specimens were available from 8 patients. Hepatomegaly and steatosis of the liver, found in every patient, were often combined with fibrosis or cirrhosis. Cardiomegaly and accumulation of fat in the myocardium, renal tubules, and skeletal muscle were found in many patients. A detailed neuropathologic examination was performed on six patients, and brain specimens obtained at autopsy were examined in four others. In general, neuropathologic findings were mild and unspecific, but vacuolization was detected in the deep gray matter and in the cerebellum and brain stem nuclei of five patients. In one patient the vacuolization was prominent; in the other four it was milder and more focal. The vacuoles seemed to be either in the neuropil or associated with swollen hydropic cells. The uniform pattern of histopathologic changes facilitates the diagnostics in this severe disorder, allowing opportunities for therapy and prenatal diagnosis.     

护心灵对大鼠心肌缺血再灌注损伤的保护作用

 目的 探讨护心灵(HXL)对心肌缺血再灌注损伤的影响。方法 采用冠状动脉结扎法制备大鼠急性心肌缺血模型,观察护心灵对其心电图、心肌梗死范围以及血清中酶活性的影响。结果 HXL可以改变缺血再灌注损伤大鼠心电图ST段的变化幅度,降低大鼠急性心肌梗死面积,抑制血清中肌酸激酶(CK)、乳酸脱氢酶(LDH)的活性,提高超氧化物歧化酶(SOD)的活力,同时降低丙二醛(MDA)的含量。结论 HXL对心肌缺血再灌注损伤具有较好的保护作用。     

银杏叶提取物对糖尿病大鼠脂质过氧化作用的影响

目的 研究银杏叶提取物(EGb)抗糖尿病大鼠心肌、睾丸、脑组织脂质过氧化作用。方法 用链脲佐菌素制备SD大鼠糖尿病模型。测定EGb对糖尿病大鼠血液葡萄糖、胰岛素水平,心肌、睾丸、脑组织内超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量的影响。结果 与糖尿病组相比,EGb治疗组大鼠血糖下降、胰岛素升高,心肌、睾丸、脑组织内SOD活性明显升高,MDA含量明显降低。结论 EGb能提高糖尿病大鼠组织抗氧化能力。