去甲肾上腺素对感染性休克患者肺循环压力的影响

目的探讨去甲肾上腺素在治疗感染性休克时对患者肺血管压力的影响。方法随机将60例感染性休克患者分为4组,每组15例。分别输注不同剂量去甲肾上腺素,观察肺动脉压和肺静脉压的变化。结果当用药剂量达到2μg／（kg·min）和5μg／（kg·min）时肺动脉压显著升高,而平均动脉压在用药剂量达到1．0μg（kg·min）时就显著升高。当用药剂量达到2μg／（kg·min）和5μg／（kg·min）时平均动脉压升高幅度显著高于肺动脉压升高幅度。结论去甲。肾上腺素治疗感染性休克不升高肺静脉压,当剂量达到2μg／（kg·min）和5μg／（kg·min）时,肺动脉压升高,但其幅度低于平均动脉压的升高幅度。     

缺氧、内毒素对清醒山羊肺动脉增压反应和肺内液体交换的影响

作者采用山羊慢性肺淋巴瘘模型,观察缺氧、小剂量的内毒素单独及复合作用,对清醒山羊肺动脉压、肺微血管壁通透性及肺组织问液形成的影响。缺氧(模拟4,000m高原,历时5小时)可使肺动脉压显著升高,但肺淋巴流量、淋巴与血浆蛋白比值及肺淋巴蛋白清除率均无明显改变。在平原注射内毒素后其反应可分为三期:(1)肺动脉高压期;(2)肺微血管损伤期;(3)肺微血管壁通透性增高期。在缺氧与内毒素复合作用时,肺动脉压、肺淋巴流量、淋巴与血浆蛋白比值及肺淋巴蛋白清除率的改变,与内毒素单独作用时基本相同。本实验结果提示:(1)缺氧与内毒素复合作用时肺动脉压增高的幅度,并作二者单独作用时幅度的叠加;(2)缺氧不能加重内毒素引起的肺损伤。     

钾对在体灌流鼠肺动脉压及肺血管反应性的影响

本文采用大鼠在体肺灌流方法，观察了钾对肺动脉压及肺血管反应性的影响。当灌流液中的ＫＣｌ浓度增至６ｍｍｏｌ·Ｌ－１时，肺动脉压无明显变化，增至９～１５ｍｍｏｌ·Ｌ－１范围内，肺动脉压呈剂量依赖性升高。以６ｍｍｏｌ·Ｌ－１ＫＣｌ灌流鼠肺，能完全消除０．０５μｇ白三烯引起的肺血管收缩反应；也能使１０ｕｇ去甲肾上腺素引起的肺动脉压升高百分率由４０±６％降低到２５±４％（Ｐ＜０．０１）；使０．１μｇ血管紧张素Ⅱ所致的肺动脉压升高百分率由２５±４％降至１３±３％     

肺动脉性高压内科药物治疗的进展

肺动脉高压定义为安静时肺动脉收缩压大于30mmHg或平均压大于25mmHg，而肺动脉性肺高压则是排除左心分流性疾病：和肺静脉高压的影响，同时要求肺毛细血管楔嵌压小于15mmHg。     

药物对雄性狗尿流动力作用的研究（Ⅰ）

观察了去甲肾上腺素─酚妥拉明、ＡⅡ对狗储尿期膀胱尿道的作用及离体膀胱肌条带对ＡⅡ的反应，结果表明去甲肾上腺素─酚妥拉明对升高尿道压作用明显，特别对前列腺部尿道压，Ｐ＜０．０１，而对膀胱的影响无统计学意义；ＡⅡ能升高膀胱压、降低膀胱容量和顺应性，但对尿道压的影响不大，能使离体膀胱肌条带明显收缩。就上述结果进行了讨论。     

高碳酸血症时的肺循环血流动力学的仿真分析

目的用计算机仿真方法评价高碳酸血症对肺循环血流动力性的影响。方法利用包含多种心血管反射的血流动力学模型,在高碳酸血症条件下,运用动态仿真工具Simulink,采用ODE45可变步长算法实现仿真。结果在高碳酸血症条件下,去除化学反射后,肺动脉压基本无变化,肺静脉压和肺毛细血管压都有一定程度的下降;而在去除压力反射后,肺动脉压显著升高。结论压力反射对肺动脉压的缓冲作用有重要意义,这对动物实验设计有启示作用。     

猫肺血管顺应性与反应性研究

本文研究了猫肺血管在不同功能状态下的顺应性与反应性。结果显示,静注去甲肾上腺素(NA)、组织胺(HiS)及肺泡缺氧均使肺血管顺应性指数(CI_(PA))降低;异丙肾上腺素(Iso)则使之升高。在缺氧及注NA时,用肺阻抗血流图与肺动脉平均压变化两种方法,测得的肺血管反应性明显相关;肺血管反应与肺血管顺应性变化也明显相关。     

前列腺素和白三烯在内毒素所致肺动脉高压中的意义

给狗一次注射大肠杆菌内毒素5μg/kg,引起肺动脉压和肺血管阻力显著增加,肺动脉嵌压无明显变化。动脉血浆血栓素β_z和6-酮-PGF1α水平及白三烯含量均明显升高。环氧合酶抑制剂消炎痛可缓解肺动脉压力升高;脂氧合酶抑制剂乙胺嗪,阻断白三烯生成及部分抑制血栓素B_2的增加,可以阻止肺动脉高压形成。提示:内毒素所致肺动脉高压与血栓素A_2和白三烯有关。     

低氧性肺静脉收缩及重塑

慢性阻塞性肺疾病患者可以合并肺动脉高压(PH),逐渐发展导致慢性肺源性心脏病。肺泡缺氧引起肺血管收缩和重塑是PH形成的原因。肺血管由动脉、静脉和毛细血管网组成。长期以来,肺动脉在PH发病中的作用受到关注,而肺静脉受到忽视。研究表明同肺动脉一样肺静脉在低氧时也会出现肺静脉的收缩和重塑,低氧时肺静脉在PH形成中的作用值得思考。     

病理生理教学实验中应培养学生研究疾病机制的能力

不少研究因设计不完善而导致错误的结论 ,如根据实验中动物吸入低氧气体可使肺动脉压升高和血中组胺浓度升高 ,给正常动物注射组胺也引起肺动脉压上升 ,就得出组胺在缺氧性肺动脉高压的发生中起介导作用的错误结论。后来实验发现 ,给动物注 H1受体阻断剂不影响缺氧性肺动脉高压的形成 ,而 H2受体阻断剂则可显著增强缺氧引起的肺动脉高压反应。表明在机体缺氧时组胺的生成增多主要作用于肺血管 H2受体使肺血管舒张 ,从而对缺氧性肺血管收缩反应起调节作用。有人仅用体外培养的肺动脉内皮细胞研究缺氧对一氧化氮合酶基因表达的影响 ,发现缺…     

Quantitative assessment of jet velocities and pressure gradients in experimentally induced aortic membranous and tunnel-like stenoses]

To assess the quantitative relationship between jet velocities and pressure gradients in membranous and tunnel-like stenoses, Doppler echo-cardiography(DE) and cardiac catheterization(CC) were performed simultaneously in 6 open-chested anaesthetized dogs. A nonelastic strip was put around the canine ascending aorta through a metal tube and tightened to produce a stenotic lesion. The cross sectional area of the aortic lumen was gradually decreased while the length of the stenotic lesion gradually increased by using strips with different width. The jet velocities and pressure gradients were recorded simultaneously using the continuous-wave Doppler and dual catheter techniques. The comparison of the peak (delta Pp) and the mean (delta Pm) pressure gradients measured by DE and CC yielded high correlations (r = 0.98, SEE = 1.17Kpa, and r = 0.97, SEE = 0.89Kpa, respectively). However, in lesions where the ratio of the length over the radius(1/r) of the stenotic segment was more than 3, DE significantly underestimated delta Pp and delta Pm measured by CC(P less than 0.001). We conclude that DE can accurately predict pressure gradients across membranous and tunnel-like stenoses, but significant underestimation may occur in stenotic lesions with 1 more than 14mm and 1/r more than 3.     

MR动态增强扫描评估正常兔肾实质的血流灌注

目的探讨动态增强磁共振检查对正常肾实质血流灌注评价的作用。方法健康大白兔9只,行肾脏动态增强MR检查,测量各肾皮质及髓质的信号强度,绘出其平均信号强度-时间曲线,记录皮质、髓质的平均峰值（P）及峰值/达峰时间比（P/T）。结果肾脏的灌注曲线（SI-T曲线）稳定,获得的血流灌注参数（Pc,Pm,Pc/Tc,Pm/Tm）具有一定规律,MR动态增强可反映出肾实质的血流动力学状态。结论动态增强MR能够反映肾脏血流灌注的变化,为兔肾血流动力学研究提供新的无创性手段。     

Effects of aerosolized histamine and carbachol in the conscious horse

Pulmonary function tests were performed in seven conscious, standing horses. Changes in pulmonary mechanics and ventilation volumes were measured after inhalation challenge with saline (baseline), histamine (1% w/v solution for 5 min) and carbachol (0.5% w/v solution for 3 min). Comparisons between baseline and posthistamine values revealed a significant (P less than 0.05) increase in nonelastic work of breathing (Wb), maximum change in transpulmonary pressure (max delta Ppl), and pulmonary resistance (RL), while dynamic compliance (Cdyn) decreased (P less than 0.05). Tripelennamine completely abolished these histamine induced changes suggesting the involvement of H1 receptors. A nonsignificant increase occurred in functional residual capacity. However, the amount of nitrogen retained in the lung at the end of a nitrogen washout test was significantly (P less than 0.05) greater after histamine when compared to baseline values. The effect of carbachol was qualitatively similar to that of histamine, Wb and max delta Ppl increased while Cdyn decreased (P less than 0.05). The increase in lower RL reached statistical significance (P less than 0.05) only at the beginning of expiration (/ 25% VT). The present investigation demonstrates that the physiological measurements of lung function could be carried out in conscious, unsedated horses and that the pulmonary function test methods could be used as a tool for study of drug induced changes in pulmonary mechanics.     

Neural histamine in the tuberomammillary nucleus regulates the onset of neurogenic pulmonary edema in rabbits

Objective:To explore the effect of neural histamine in the tuberomammillary nucleus(TM) on neurogenic pulmonary edema (NPE) onset in rabbits and the function of the rostral ventrolateral medulla(RVLM) in the neural histamine modulation of NPE. Methods: NPE was produced by the intracisternal injections of fibrinogen and thrombin. The contents of histamine in the TM and RVLM in rabbits were measured with high performance liquid chromatography(HPLC). Rabbits were placed on a stereotaxic frame and microinjectio...     

764—3对炎症时肺组织胺含量及成纤维细胞生长的影响

博莱霉素所致肺急性(7d)与亚急性(21d)炎症时,肺内组织胺含量明显升高;而764-3则可使肺组织胺含量下降至接近正常。另外,组织胺对肺成纤维细胞具有时间及剂量依赖性促生长作用,764-3可抑制这一作用。提示组织胺在博莱霉素致肺纤维化中具有一定作用,764-3对这一过程有抑制作用。     

Experimental study of the protective effects of N-acetylcysteine on endotoxin-induced acute lung injury]

The purpose of this study was to investigate the effects of NAC (N-acetylcysteine) on endotoxin induced acute lung injury in unanesthetized sheep. The results showed that NAC attenuated the responses to endotoxemia, and the rise in pulmonary artery pressure was significantly diminished, and the rise of TXB2 and 6-keto-PGF1 alpha in plasma and lung lymph was less significantly for NAC + E than for E alone. The QL (lung lymph flow), PC (lung lymph protein clearance) and PS (pulmonary capillary surface permeability area) were significantly decreased in NAC + E group. The lipid peroxide contents in artery plasma and lung lymph were not increased in NAC-treated group. We conclude that NAC is capable of attenuating all pathophysiologic changes after endotoxin infusion, blocking the reaction of oxygen free radicals, and protecting lungs from oxidant damage.     

双向喷射通气对组胺狗模型血气的影响

比较HFTJV和HFJV对组胺所致狗肺损伤模型动脉血气的影响。取健康犬6条,以戊巴比妥钠行腹腔麻醉。组胺输注致肺损伤,测定损伤前和损伤后的有关数据进行比较。结果:输注组胺使PaO_2显著降低而PaCO_2明显增高;两种喷射通气在致伤前后吸气末压无显著差异(P>0.05),HFTJV时的呼气末压显著低于致伤后HFJV时(P<0.01);HFTJV时使致伤后PaO_2显著高于HFJV(P<0.05);两种通气均使致伤前后PaCO_2显著降低,但HFTJV使PaCO_2降低较HFJV显著(P<0.05)。表明:HFTJV与HFJV相比,在气道压力进一步降低的条件下,能增强氧合及CO_2的排出。     

实验性急性胰腺炎大鼠肺内肿瘤坏死因子αmRNA的表达及其意义

为了解急性胰腺炎（ＡＰ）时,肺组织中肿瘤坏死因子（ＴＮＦ）转录水平上调在肺损伤机制中的意义,作者以半定量逆转录聚合酶链反应（ＲＴ－ＰＣＲ）技术,检测了急性水肿性胰腺炎（ＡＥＰ）与急性坏死性胰腺炎（ＡＮＰ）两种模型的大鼠肺组织内ＴＮＦ－αｍＲＮＡ表达的状况,同时观察了它与内毒素（ＥＴ）血症及肺损伤的关系。结果表明,ＡＮＰ组血ＴＮＦ－α水平（１０７．４±４９．７ｐｇ／ｍｌ）显著高于ＡＥＰ组（５５．８±     

儿茶酚氧位甲基转移酶基因多态性与精神分裂症关联分析

目的 探测中国汉族人儿茶酚O 甲基转移酶(COMT)基因第 108位密码子由缬氨酸到甲硫氨酸突变的多态性与精神分裂症的关系。方法 应用聚合酶链反应 (PCR)和限制性片段长度多态性(RFLP)技术,检测 309例精神分裂症患者(患者组)和 367名正常人(对照组)的COMT基因多态性。结果(1)患者组COMT等位基因A频率(23. 78% )低于对照组( 30. 93% ),等位基因G频率 (76. 22% )高于对照组(69. 07% ),差异均有非常显著性(P=0. 003)。按性别比较,等位基因A和G频率在两组男性之间的差异均具显著性(P=0. 02),而两组女性间的差异则不具显著性(P=0. 073)。(2)COMT基因A/A基因型频率两组的差异无统计学意义(P=1. 000, P=0. 815).患者组及其男性和女性的A/G基因型频率(分别为 39. 80%、40. 75%和 39. 35% )均低于对照组(分别为 53. 68%、55. 76%和 51. 98% );P=0. 000,P=0. 006,P=0. 018。患者组及其男性和女性的G/G基因型频率(分别为 56. 32%、57. 15%和 55. 48% )均高于对照组(分别为 42. 23%、41. 21%和 43. 07% );P=0. 000、P=0. 004和P=0. 020。结论 该结果提示,在我们研究的样本中COMT108Met多态性与精神分裂症关联。所以,不能排除中国汉人 22号染色体存在精神分裂症易患性基因的可能性。