硝普钠对动物血管力学参数的影响

有研究表明硝普钠具有增加动脉顺应性的趋势和降低外周阻力的作用,但是硝普钠对血管中血流惯性的影响却不统一。本文以Coldwyn等建立的动脉系改良风箱力学模型为主要研究方法对动物动脉血管顺应性(包括中央和外周顺应性),血流惯性和外周阻力等进行了研究,并建立了动脉系总阻抗的公式。然后评价硝普钠对总阻抗的影响以及总阻抗做为一种血管力学参数的灵敏性。实验结果表明:硝普钠具有统计学意义地增加外周血管的顺应性(P<0.05);有增加中央动脉顺应性和血流惯性的趋性;并能降低外周阻力和动脉系总阻抗(P<0.05)。结果还表明动脉系总阻抗是一种灵敏度高的血管力学参数。因此,硝普钠能影响血管参数,对外周血管顺应性和血管总阻抗的作用尤其明显。     

硝普钠对急性胰腺炎大鼠治疗作用初探

目的与方法:为探索硝普钠对急性胰腺炎(AP)的治疗作用,采用胰管内注射牛磺胆酸钠溶液的方法建立大鼠AP模型,并用外源性一氧化氮(NO)供体硝普钠(SNP)实验性治疗,动态观察AP模型复制后(8、16、24、48h)血浆NO、超氧化物歧化酶(SOD)和淀粉酶含量的变化及胰腺组织学改变。结果:AP组血浆NO、SOD明显下降(P＜0.05),并持续24h以上,血浆淀粉酶含量明显升高(P＜0.05),而治疗组血浆NO、SOD明显高于非治疗组(P＜0.05),淀粉酶含量明显下降(P＜0.05)。治疗组胰腺组织病理损害明显轻于模型组。结论:大鼠实验性急性胰腺炎时,血浆NO含量、SOD活性明显下降,早期腹腔注射硝普钠能显著升高血浆NO、SOD含量,降低血浆淀粉酶含量,减轻胰腺病损。本实验为临床急性胰腺炎的早期治疗提供一新途径。     

硝普钠对海马神经元cpp32基因表达的影响

为观察NO供体硝普钠对体外培养的海马神经元cpp32基因表达的影响，采用终浓度分别为0、25、50、100、200、400μmol/L的硝普钠处理海马神经元24h，用RT－PCR检测mRNA表达变化，Western blot检测蛋白表达的变化；再用终浓度分别为0、25、50、100、200μmol/L的硝普钠处理海马神经元12h，用CPP32活性检测试剂盒检测CPP32酶活性。结果表明，随着硝普钠剂量的增加，cpp32mRNA表达无改变；但CPP32酶原被裂解活化，从50μmol/L硝普钠起，酶活性显著增加，为对照组的3．02倍，100μmol/L达最大值，为对照组的3．47倍，这说明硝普钠不增加cpp32 mRNA的表达，但可诱导CPP32酶原的裂解，使CPP32活化。     

保心胶囊对实验性犬心肌缺血血流动力学的影响

目的:观察保心胶囊对结扎犬心肌缺血时心脏血流动力学的影响。 方法:实验分假手术对照组,缺血组,缺血+地奥组,缺血+保心低剂量组,缺血+保心中剂量组,各组犬连续灌胃(生理盐水或药物)三天后,结扎犬心脏冠脉左前降支复制急性心肌缺血模型,测定犬不同时点的血压、血流量及左室等容期压力最大变化速率的变化。结果:保心中剂量组对血压、血流量及左室等容期压力最大变化速率的作用与缺血组比较有显著差异(P＜0.05)。结论:保心胶囊具有改善心肌缺血、增强心肌舒缩能力的作用。     

硝普钠在心肺移植中对肺的保护作用

心肺移植是治疗终末期心肺联合病变的一种有效方法。其中移植肺更易受损 ,因而移植肺保护的好坏是心肺移植成败的重要因素之一。我们通过改良后的Ｋａｎｅｋｏ兔异位心肺移植模型[1] 观察一氧化氮 (ＮＯ)供体硝普钠对供体肺的保护作用。1　材料和方法1 1　研究对象及术前处理 :健康青紫兰兔 ,体重 2 0～2 5ｋｇ ,随机分为实验组及对照组 ,每组 8对供、受体 ,各组之间体重差异无显著性。供、受体均用 3%戊巴比妥钠经耳缘静脉注射麻醉 (1ｍＬ/ｋｇ)。供、受体均为清洁手术。1 2　供体制备 :供体兔仰卧位 ,气管切开插管接呼吸机 ,2 1%Ｏ2 ,呼…     

实验性肺水肿大鼠血浆中内皮素,一氧化氮含量的变化以及硝普钠,川芎嗪？…

静脉注射大剂量肾上腺素引起肺水种,症状典型、剧烈,动物全部迅速死亡,其机理类似于临床上的中枢性肺水肿[1,2],为一种混合性肺水肿,此类肺水肿时肺动脉压[3]及肺楔压明显增高(以后者为主),肺泡通透性也明显增高[4],肺间质腔及肺泡腔内充满含有大量蛋白的水肿液.为进一步了解此类肺水肿发病机制,探讨儿茶酚胺与内皮素(ET-1)、一氧化氮(NO)释放的关系,我们对肺水肿及采用文献报道对肺水肿具有良好预防作用的硝普钠(NP)[2]、川芎嗪(TMP)[3]预防时大鼠血浆中的ET-1、NO含量及二者的增高倍数进行了测定与探讨.     

实验性肺水肿大鼠血浆中内皮素、一氧化氮含量的变化以及硝普钠、川芎嗪对其的影响

在肾上腺素所致大鼠肺水肿实验中，发现其血浆中内皮素（ET－1）明显升高，一氧化氮（NO）稍有增高，但ET－1的增幅远远大于NO的增幅，动物均在15min内死亡。ET的增高与儿茶酚胺的升高有密切关系。经硝普纳（NP）、川芎嗪（TMP）预防后，ET－1与NO基本恢复正常，趋于平衡，动物长期存活。提示：肺水肿时NO相对于ET－1明显降低，NP、TMP可对NO与ET的平衡起调节作用。     

硝普钠、速尿对急性心肌梗塞左心衰竭患者微循环的影响

目的 探讨硝普钠和速尿对急性左心衰患者微循环的影响。方法 将６０例急性心肌梗塞左心衰患者随机平均分成两组,一组静滴硝普钠,另一组静注速尿。通过微循环显微电视系统观测甲襞微循环多项指标变化。结果 硝普钠组血流状态改善,微血管襻数目增加,红细胞聚集减轻。速尿组微血管襻数目减少,红细胞聚集加重。结论 反复应用速尿,对心梗患者有诱发休克和再梗塞之弊。     

硝普钠对核因子κB活性影响的初步研究

目的:探讨不同浓度的硝普钠(SNP)对人外周血T淋巴细胞核因子kappa B(NF-κB)活性的影响及机制。方法: 应用人外周血T淋巴细胞培养、Western blot和RT-PCR等技术,观察不同浓度的一氧化氮(NO)供体SNP对人T细胞受植物血凝素(PHA-P)刺激30 min、120 min后IκB_α mRNA和蛋白质表达的影响。结果:中高浓度的SNP能显著减少PHA-P刺激30 min时IκB_α蛋白的降解,并明显增加刺激120 min时IκB_α mRNA的再表达。结论: 中高浓度的SNP抑制NF-κB活性的机制与其通过NO减少IκB_α降解、促进IκB_α再合成有关,而低浓度SNP对NF-κB活性影响的机制可能不是通过IκB_α。     

深静脉置管引流术在心包积液中的临床应用

目的:探讨经皮心包穿刺置管引流心包积液的疗效及安全性。方法:对28例中到大量心包积液的患者在床边进行心包穿刺置管,置管后引流。结果:28例患者均置管成功,留置时间平均7d(3~15d),均无组织脏器损伤及感染。结论:经皮心包穿刺置管引流治疗心包积液,具有操作方便,疗效可靠,穿刺并发症少等优点。     

心包积液时右心房与心包腔内压力关系的临床研究

目的：研究心包积液时右心房与心包腔内压力关系,并对心包填塞分级。方法：采用右心导管和剑突下穿刺术,同步连续测定１５例患者的右房和心包腔内压力,直到心包造影证实积液基本抽完时为止。结果：心包积液时,右房压始终高于心包压,压差随心包内压力升高而减小,范围从０１３～０．４０ｋＰａ。心包填塞者,当抽液到１５０ｍＬ时,右房和心包内压力下降曲线最为陡峭。压力越高,下降幅度越大。当抽液２５０ｍＬ时,心包舒张压显著低于右房舒张压。结论：在心包填塞时,右房和心包腔内压力相近,但不相等,前者稍高于后者。在心包积液基本抽完时,心包压与胸膜压相近似。依据右房压,可将心包填塞程度分为无症状、轻、中、重和危象５级。     

Metastatic squamous-cell carcinoma in pericardial effusion: Report of four cases,two with cardiac tamponade

For reasons unknown, metastatic squamous-cell carcinoma is a rare cause of pleural effusions and is even less common in pericardial effusions. A review of all pericardial effusions examined in the Cytology Service at Montefiore Medical Center over a 15-year (1980–1994) period was undertaken (N = 251). Four cases with metastatic squamous-cell carcinoma were identified among 39 malignant effusions. Two patients with metastatic squamous-cell carcinoma presented with cardiac tamponade, and the other two cases had progressive cardiac failure. The diagnostic cells on cytology evaluation were scant in all four cases but exhibited classical features of metastatic squamous carcinoma, such as cytoplasmic keratinization, intercellular bridges, and occasional “pearl” formation. Pericardial biopsies available in three patients, two with cardiac failure and one with cardiac tamponade, were negative. In all four cases the primary tumor was a bronchogenic carcinoma. Metastatic squamous-cell carcinoma is an uncommon cause of pericardial effusion and usually indicates the presence of a bronchogenic carcinoma with a rapidly fatal outcome. Cytologic examination of pericardial fluid is essential in the evaluation of such patients. Diagn. Cytopathol. 1998;18:422–424. © 1998 Wiley-Liss, Inc.     

Effects of volume expansion and vasodilators in acute pericardial tamponade

Pharmacologic therapy may be useful as emergency treatment for acute pericardial tamponade while preparing for pericardiocentesis. We studied the effects of volume expansion and vasodilators in acute pericardial tamponade in spontaneously breathing mongrel dogs. Hemodynamic parameters and blood flow (15-micrometer microspheres) to brain, heart, kidney, colon, stomach, liver, and temporalis muscle were measured. Arterial pressure and cardiac output rose, and blood flow to all major organs, except stomach, increased after volume expansion (n = 17) by infusion of 20 ml/kg of dextran after tamponade. With nitroprusside (8-75 microgram/min) after volume expansion (n = 5), ventricular filling pressures were reduced to control levels, whereas the favorable effects of volume expansion on cardiac output, blood pressure, and kidney and heart blood flow were maintained. Hydralazine alone or hydralazine plus volume expansion was not as effective as the combination of nitroprusside and volume expansion. Thus, volume expansion alone or the combination of volume expansion and nitroprusside infusion should be beneficial as emergency therapy while preparing for pericardiocentesis in patients with acute pericardial tamponade.     

Cyanide toxicity of sodium nitroprusside in therapeutic use with and without sodium thiosulphate

Summary Sodium nitroprusside (SNP) as a monoinfusion was administered to 51 patients for periods of a few hours. A further group of 19 patients received SNP for periods of several days as a combination solution of SNP mixed with sodium thiosulphate. The concentrations of cyanide and of thiocyanate in the blood of all patients were measured. In seven of the patients the level of thiosulphate was also measured. Infusion of SNP on its own at levels exceeding 2 µg/kg/min led to the rising of cyanide levels in the blood being proportional to dosage. Infusion of SNP mixed with thiosulphate showed no such accumulation of cyanide in any patient, irrespective of dosage level and duration. The efficacy at lowering blood pressure was fully maintained in the mixed infusion. The elimination half-life for thiosulphate was 16.5 min. Pharmacokinetic calculation of the rise in cyanide level showed that mono-infusions of 5–10 µg SNP/kg/min could within 5–10 h cause a life-threatening cyanide level in the blood. By contrast, mixed influsion of SNP together with thiosulphate, for which light-opaque syringes and tubing must be used, is a procedure free of danger and should become the technique of choice when therapeutically administering SNP in order to lower blood pressure.Supported by the Deutsche Forschungsgemeinschaft     

心脏外伤并发急性心包填塞影像特点与救治体会

心脏外伤多由锐器刺伤前胸心脏危险区引起,当并发急性心包填塞时可因心源性休克导致伤员死亡.自1980年至2002年8月间,我科收治7例心脏外伤并发急性心包填塞患者,其中2例在入院途中呼吸和心跳停止,临床死亡;5例经手术抢救治愈.现结合文献将心脏刀刺伤并发急性心包填塞影像特点和救治体会报告如下.     

The development of pericardial villi in the chick embryo

Summary The development of pericardial villi and their relation to the development of the cardiac surface was studied in chick embryos from the 3rd to 10th day of incubation by scanning electron microscopy. During the 3rd day of incubation (stage 14–17 HH) the coelomic epithelium covering the ventral wall of the sinus venosus forms villous protrusions. By the end of the 3rd day (stage 17 HH) these protrusions contact the dorsal wall of the heart, so that a secondary dorsal mesocardium is formed. This bridges the pericardial cavity between the ventral wall of the sinus venosus and the dorsal base of the ventricles. This sinu-ventricular mesocardium exists only temporarily, as on the 8th day of incubation it becomes a part of the cardiac wall due to fusion with the epicardium of the coronary sulcus. During the 4th and 5th day of incubation (stage 17 – 25 HH), the formation of the epicardium proceeds from the point of attachment of the sinu-ventricular mesocardium. Although these findings suggest that the epithelium of the villous protrusions spreads over the surface of the embryonic heart, one cannot exclude other hypotheses on epicardial origin. The impression of a spreading epicardium could also be created if epicardial cells were to delaminate from a local epithelium in a temporally and spatially organized pattern.