Analysis of a decreased Na+ conductance by tumor necrosis factor in identified neurons of Aplysia kurodai.

The ionic mechanisms of the effect of extracellularly ejected recombinant human tumor necrosis factor-alpha (rhTNF-alpha) on the membrane of identified neurons R9 and R10 of Aplysia kurodai was investigated with conventional voltage-clamp, micropressure ejection, and ion substitution techniques. Micropressure-ejected rhTNF caused a marked hyperpolarization in the unclamped neuron. Clamping the same neuron at it resting potential level (-60 mV) and reejecting rhTNF-alpha with the same dose produced a slow outward current [Io (TNF)] associated with a decrease in input membrane conductance. Io (TNF) was decreased by depolarization and increased by hyperpolarization. The extrapolated reversal potential of Io (TNF) was approximately +10 mV. Ion substitution and pharmacological experiments suggest that Io (TNF) in identified neurons R9 and R10 of A. kurodai is due to a decreased Na+ conductance but not due to an activation of the Na(+)-K+ pump. Our results demonstrate that the immunomodulator TNF can act directly on the nervous system as well as on the immune system.     

酥胆麒麟膏用于痔瘘术后换药的药效学与毒理学研究（二）

本文通过设一个阳性对照组（马应龙鹰香痔疮膏），一个空白对照组（凡士林）及酥胆麒麟膏大、中、小三个剂量组（１０％、２０％、４０％浓度）进行三个方面的实验研究，证实酥胆麒麟膏具有止血、抗菌、生肌长皮等综合作用，局部外用无毒副作用，安全性高。其止血、生肌长皮作用，优于马应龙麝香痔疮膏；抗金葡萄茵的作用与银灰散相同；抗大肠杆菌的作用犹于银灰散。尤其是２０％酥胆麒麟膏的以上多种作用优于１０％浓度的，等效于４０％浓度的，可作为临床使用时的最佳浓度。     

Electrophysiologic mechanisms of ventricular arrhythmias

In this work the electrophysiologic mechanisms of ventricular arrhythmias have been briefly summarized. Ventricular arrhytmias can be caused either by pacemaker activity or by reentrant excitation. Enhancement of normal automaticy can generate a parasystolic rhythm in normal fibers. Abnormal automaticity may arise fom fibers in which maximum diastolic potential has been reduced by a variety of interventions. Triggered activity is caused by either an early (EAD) or delayed (DAD) afterdepolarization and requires a prior normal action potential for initiation. While there is growing evidence that EAD-induced triggered activity plays a significant role in the Long QTU syndrome and Torsade de Pointes, no clinical arrhythmias has definitely been ascribed to DADs, although DADs have been recorded in man after acute digoxin intoxication.Ventricular arrhytmias can be also caused by reentrant excitation, which can be subdivided into reflection or circus movement reentry (CMR). In the reflection model impulses in both directions are transmitted over the same pathway. In the CMR three models can be differentiated: the ring model, which requires a fixed anatomical obstacle; the figure-eight model and the leading circle model, where functional rather than fixed anatomical obstacles are involved.Abbreviations AV atrio-ventricular - CMR circus movement reentry - DAD delayed afterdepolarization - EAD early afterdepolarization - ECG electrocardiogram - LV left ventricle - MAP monophasic action potential - MF muscle fiber - PF Purkinje fiber - RV right ventricle - TdP Torsade de Pointes     

Acute actions of insulin-like growth factor II on glucose metabolism in adult rats

Summary The metabolic potency of recombinant human insulin-like growth factor II was studied in anaesthetized adult rats by obtaining dose-response curves for the hypoglycaemic action and for the stimulation of glucose metabolism during euglycaemic clamping. Compared to insulin, about 50 times higher doses of insulin-like growth factor II were required to result in identical in vivo responses, with half-maximally effective serum concentrations for the stimulation of glucose disposal during clamp studies of about 0.8 and 50 pmol/ml, respectively. A similar difference in potency was observed for the dose-dependent stimulatory actions on glucose metabolism in individual target tissues. Half-maximally effective serum concentrations in the range of 0.8 to 3.0 pmol/ml for insulin and of 40 to 70 pmol/ml for insulin-like growth factor II were seen to be required for 2-deoxyglucose uptake, glycogen formation in skeletal muscle and lipogenesis in epididymal fat. Maximal responses were identical with both peptides. These data suggest that in vivo acute metabolic actions of insulin-like growth factor II on carbohydrate metabolism occurred through insulin receptors.     

Dopamine antagonists reduce spontaneous electrical activity in cultured mammalian neurons from ventral mesencephalon

Mammalian neurons from ventral mesencephalon (VM) were grown in primary dissociated cell (PDC) culture. These neurons are predominantly non-dopaminergic. Many of these non-dopaminergic neurons have dopamine agonist and antagonist binding sites. Intracellular recordings were obtained from these neurons. When bathed in phosphate-buffered saline (PBS) solution they generated action potentials spontaneously. However, in the presence of haloperidol dissolved in PBS solution, the percentage of neurons which generated action potentials spontaneously was reduced in a dose-dependent manner (1–10 μM). This response was also obtained with (+) butaclamol (1 μM) but not with (−) butaclamol (1 μM). This neuroleptic inhibition of spontaneously generated action potentials was specific for neurons in PDC cultures of VM since neurons in PDC cultures of spinal cord did not demonstrate this phenomenon.     

原钒酸钠对Ⅱ型糖尿病的降糖作用研究

目的　观察原钒酸钠对Ⅱ型糖尿病大鼠的降糖作用。方法　用高脂饲料灌胃正常大鼠 ,引起肥胖 ,测定血中游离脂肪酸浓度。同时应用正糖钳技术检测胰岛素抗性 ,对产生胰岛素抵抗的大鼠腹腔注射小剂量链脲菌素 (5 5mg·kg-1) ,然后筛选空腹血糖值大于 11 1mmol·L-1大鼠为糖尿病模型组。连续灌胃原钒酸钠 7d后 ,测定空腹血糖值。结果　①大鼠喂食高脂饲料后 ,正糖钳实验中维持血糖稳态所需胰岛素量增多 ,为 (0 5 4± 0 0 2 )U·min-1,高于正常组 (P <0 0 1) ;同时血中游离脂肪酸浓度增加 ,从正常 (0 4 6 9±0 0 4 7)mmol·L-1至 (1 5 32± 0 2 91)mmol·L-1(P <0 0 1) ;②原钒酸钠对正常大鼠的血糖值无影响 ,而对Ⅱ型糖尿病大鼠的空腹血糖值及糖耐量曲线下面积有降低作用 (P <0 0 5 )。结论　实验结果证明了原钒酸钠可以明显降低Ⅱ型糖尿病大鼠的空腹血糖值 ,并且对糖耐量具有保护作用     

精神分裂症患者心理防御机制与人格特征的相关性分析

目的　探讨精神分裂症患者心理防御方式和人格特片的特点及二者的相关性。方法　分别运用防御方式问卷 (DSQ)和艾森克个性问卷 (EPQ)对 10 1名精神分裂症患者和 30例正常人群进行防御方式评定和人格测定。结果　与正常对照组相比 ,精神分裂症患者更多采用不成熟和中间型防御方式 (P <0 0 5 )。防御方式与人格特征存在着一定的关联性 (P <0 0 5 )。不成熟型防御方式和中间型防御机制与EPQ的精神质 (P)得分和神经质 (N)得分呈显著正相关 (P <0 0 1) ,成熟防御机制与内外向(E)得分呈显著正相关 (P <0 0 5 )。结论　精神分裂症患者更多地使用不成熟防御机制 ,存在病态人格 ,且者之间存在明显相关性 ,有关结果 ,对于探讨精神分裂症患者的病理心理机制和开展心理治疗有指导意义。     

病理性近视眼的研究进展

通过复习近年来相关文献,对近视眼发生发展机制与形觉剥夺之间的关系进行综合评述。认为近视眼的发生及眼轴延长与形觉剥夺有一定关系,深入研究其相关机制,对近视眼的早期防治具有重要意义。     

浅析《内经》之闭经证治

收集了《内经》有关闭经方面的相关阐述从而探讨闭经的病因病机、诊断与治疗,并详细记述了《内经》对血滞经闭和血枯经闭这两类型经闭的不同治疗法度。