听性脑干反应和蜗神经直接动作电位联合听觉监护在侧颅底手术中的应用

目的:通过听性脑干反应(ABR)和蜗神经动作电位(CNAP)在侧颅底外科手术中的应用,分析造成听力损伤的原因,并对这两种听觉监测技术作出评价。方法:在手术过程中对14例保留听力的侧颅底手术的患者进行听觉监测。ABR在整个手术过程中监测,CNAP在打开脑膜、暴露蜗神经后进行监测。在患者出院后1个月左右随访听力。结果:所有患者在手术过程中都有不同程度的ABR变化,尤其是耳科电钻使用后[相对使用前延长(0.19±0.16)ms)]和颅内操作时[相对操作前延长(0.29±0.25)ms]。部分患者的波形潜伏期延长在术毕时有所恢复[10例,平均缩短(0.27±0.16)ms]。结论:侧颅底手术中应用听觉监护能防止听觉损伤。电钻使用造成的震动和噪声对听力有损伤,解除引起波形潜伏期延长的诱因后可恢复部分听力。术后的听力预后与术毕潜伏期的延长有相对应关系。术中监测的新趋势是联合应用ABR和CNAP,取长补短。     

Effect of intravenous ketanserin on the human action potential duration at fixed heart rate

Summary In this study any changes in action potential duration or Q-T interval due to acute doses of ketanserin were monitored. The effect of a bolus dose (10 or 20 mg) followed by an infusion (10 or 20 mg over 20 minutes) of ketanserin on the Q-T interval and action potential duration was studied in six patients undergoing routine cardiac catheterization. Action potential duration was measured with a silver-silver chloride electrode catheter while heart rate was kept constant by atrial pacing and reflex effects avoided by -adrenergic blockade. There were some prolongations of the action potential duration but they were not in excess of 40 msec and did not reach statistical significance (control 263±46.0 msec; bolus 269±52.1 msec; infusion 262±53.6 msec; nor were there any significant changes in Q-T interval. Thus acute intravenous doses of ketanserin, in the absence of hypokalaemia or other Q-T interval-prolonging drugs, have no consistent effect on Q-T interval or action potential duration; prolongation of the action potential, when it occurs, is small.     

Antiserotonergic inhibition of calcitonin-induced increase of β-endorphin,ACTH, and cortisol secretion

Summary In a previous study we observed that calcitonin increases -endorphin, ACTH, and cortisol secretion. We assumed that calcitonin might have a modulatory role on the pituitary function. The present study was initiated to clarify whether this effect is due to a direct pituitary stimulation or to an indirect stimulation through CRF (corticotropin releasing factor).Fourteen healthy subjects, aged 30–60 years were investigated. All the subjects received 100IU Salmon calcitonin Sandoz i.v. at 8a.m. (time 0). Plasma -endorphin, ACTH and cortisol were estimated every 30min from – 30 to 120 min by specific radioimmunoassay. The same parameters were estimated a second time, at the same intervals, when cyproheptadine 8 mg (7 subjects) and 40 mg propranolol (7 subjects) were given per os at – 30 min and calcitonin i.v. at time 0. -endorphin, ACTH and cortisol levels (Mean ±SEM) rose significantly after calcitonin (peak value at 30–90 min) from 5.2 ±0.7 to 15.1±2.6 pmol/l; from 43.0±2.7 to 70.7±4.1 pg/ml and from 10.6±1.5 to 19.6 ±2.1 g/100 ml respectively (p< 0.0001 by analysis of variance and covariance and repeated measures). Propranolol 40 mg (per os) administered at time – 30 did not alter the response of -endorphin, ACTH and cortisol to calcitonin (infused at time 0).Cyproheptadine, the antiserotonergic substance that inhibits the synthesis and release of CRF completely inhibited the stimulatory effect of calcitonin.We conclude that probably calcitonin has a modulatory role on the hypothalamo-pituitary adrenal axis and that it acts at the hypothalamic level probably by stimulating CRF secretion.     

抗肿瘤药复方三生注射液的研究

复方三生注射液是由生附片等六味中药组成的静注用灭菌水溶液。本文综合报道了该制剂的制备方法,质量分析,抗肺癌作用的药理及临床等研究的主要内容。结果表明,本品是治疗中晚期肺癌有效的中药复方注射剂。     

民族药香青兰化学成分及药理作用研究进展

摘要：目的：对民族药香青兰进行化学成分及药理活性的研究,对该药材的综合应用和深入研究奠定基础。方法：通过查阅1995-2022年知网、PubMed中的中英文文献与相关文献对香青兰进行综述。结果：经过系统的研究,发现香青兰的组成主要包含总黄酮和黄酮苷类、挥发油、三萜类和蛋白质等。这些成分有着多种药理作用,如抗缺氧、抗血栓和降血压。结论：香青兰对于治疗高血压,心脏病等有一定疗效。香青兰在蒙医临床中应用广泛。研究表明,香青兰的化学成分和药理作用已经取得了一定的进展,其作用范围广泛,对心血管疾病有显著的疗效。     

The sustained inward current in sino-atrial node cells of guinea-pig heart

 Single myocytes were dissociated from the sino-atrial (SA) node of guinea-pig hearts. Only a quite small fraction of the cell population showed spontaneous action potentials and these cells were characterized by the presence of the hyperpolarization-activated cation current I _f , the delayed rectifier K⁺ current I _K and the L-type Ca²⁺ current I _Ca,L as well as by the absence of both the transient outward current I _to and the inward rectifier K⁺ current I _K,1. After blocking I _f and I _K, depolarizing pulses from –80 mV revealed a large nicardipine-sensitive late current (NSLC). The NSLC was scarcely affected by decreasing extracellular [Ca²⁺] ([Ca²⁺]_o) from 1.8 to 0.1 mM, while it was decreased significantly by depleting [Na⁺]_o, differently from I _Ca,L. NSLC was blocked by nicardipine and was increased by Bay K 8644. NSLC was increased by isoprenaline and the additional application of acetylcholine reversed the increase of this current. We conclude that NSLC is largely composed of I _st described in the rabbit SA node pacemaker cells, and that I _st is unique for the pacemaker cells in mammalian SA node cells. Most of the quiescent cells showed neither I _f nor I _st. Received: 22 July 1996 / Received after revision: 30 September 1996 / Accepted: 9 October 1996     

Opioid peptides selective for mu- and delta-opiate receptors reduce calcium-dependent action potential duration by increasing potassium conductance

We suggest that both mu- and delta-opiate receptors on dorsal root ganglion neuron somata are coupled to voltage- and/or calcium-dependent potassium channels since opioid peptide decreases of calcium-dependent action potential duration were: (1) not associated with a change of resting membrane potential or conductance; (2) accompanied by an increase in action potential after-hyperpolarization, and (3) blocked by intracellular injection of the potassium channel blocker cesium [18]. In contrast, norepinephrine [4] and cadmium [9], which have been reported to act on voltage-dependent calcium rather than potassium channels, shortened action potential duration and decreased after-hyperpolarization amplitude, an action not blocked by intracellular iontophoresis of cesium.     

左氧氟沙星延长离体豚鼠乳头肌的动作电位时程

目的观察左氧氟沙星(LVFX)对豚鼠心肌动作电位的影响,并以司帕沙星(SPX)为阳性对照物比较二者对心肌的毒性作用。方法微电极记录豚鼠右心室乳头肌动作电位。结果刺激频率为1 Hz时,各浓度的SPX均显著性延长APD50和APD90,而LVFX浓度超过10μmol/L时明显延长APD50和APD90。结论LVFX和SPX均引起APD延长,前者效应较后者弱,仅在大剂量时有导致QT间期延长的潜在毒性。     

分析探讨神经干复合动作电位

目的：讨论分析蛙神经干动作电位，为电生理实验课教学提供一些创新思路。方法：制备蛙的坐骨神经标本，在原有教学实验设计的基础上，就记录距离。麻药阻滞对神经干复合动作电位的波形、幅度、潜伏期及时程的影响，传导速度的计算方法等问题进行深入分析。结果：增大两记录电极距离，在一定范围内第一相峰值逐渐升高，持续时间延长，第二相峰值逐渐减小，电位持续时间逐渐延长，记录两点间滴加麻药，动作电位的波形第一相峰值逐步加大，第二相逐渐变小，直至消失形成单相动作电位；利用顶点所测速度与起点法测量值不相等。结论：讨论分析该实验结果能更好地使学生理解神经干复合动作电位的原理，牢固掌握基本的电生理知识。