Calcium-activated proteolysis of intracellular domains in the cell adhesion molecules NCAM and N-cadherin.

One of the consequences of increased intracellular calcium in response to a variety of physiological stimuli is the calcium activation of cytosolic proteases. Unlike lysosomal proteases with broad specificity, these calcium-activated neutral proteases show limited proteolysis of a restricted set of substrate proteins suggesting they may play a regulatory role in cellular physiology. In this study we show that the neural cell adhesion molecules NCAM-180 and N-cadherin are substrates for such endogenous calcium-activated neutral proteases. In contrast, a third neural cell adhesion molecule G4/L1 was not susceptible to calcium-activated proteolysis. The threshold for activation of NCAM and N-cadherin proteolysis is in the micromolar range of calcium suggesting that NCAM and N-cadherin are substrates for a mu-type calpain (calpain I). The site recognized by this protease is within intracellular domains of NCAM-180 and N-cadherin which are important for their interaction with cytoskeletal components. These results suggest that calcium-activated proteolysis at these sites in vivo could disrupt the linkage between extracellular ligand binding to these adhesion molecules and the normal intracellular effectors of such extracellular binding events.     

高热惊厥214例临床分析

本文分析了214例高热惊厥,结果为:检出率4.35％;男女之比为1.61:1;好发年龄为6个月～6岁(93.5％);首发年龄为6个月～4岁(89.9％);惊厥发作时体温多在39℃以上(74.6％);惊厥发作多在发热后12h内(72.4％);每次热病中惊厥发作1～3次(99.5％);惊厥持续时间多在15min内(91.0％);致惊厥发作的热性疾病以上呼吸道感染为最多;214例中63例复发,其中2例转癫痫,61例尚未发现智力低下或其他异常。从2例转癫痫的临床及脑电图看,提示惊厥发作愈重,持续时间愈长,转癫痫的可能性愈大。     

Intracellular Ca2+ suppressed a transient potassium current in hippocampal neurons

The effects of intracellular Ca2+ (Ca2+i) on K+ currents in hippocampal cells were examined using acutely isolated cells obtained from adult guinea pigs. Whole-cell voltage-clamp recordings were carried out in a configuration that allowed a continuous perfusion of the intracellular medium. Recording media were made to block inward currents and allowed selective activation of K(+)-dependent outward currents. Voltage-dependent outward currents consisted of an initial rapidly decaying component followed by a sustained component. The time constant of decay of the transient current was about 25 msec, and previous studies (Numann et al., 1987) showed that the kinetic and pharmacological properties of this current closely resembled the A current recorded in invertebrate neurons (Connor and Stevens, 1971; Thompson, 1982). Intracellular perfusion of hippocampal cells with a solution containing elevated Ca2+ (about 4.5 x 10(-4) M) elicited outward currents at the holding potential (-45 to -55 mV) and produced changes in voltage-dependent K+ currents. The transient outward current (IA) activated by depolarization was suppressed with increases in Ca2+i. Delayed, sustained K+ currents were greatly potentiated. Data also showed that, among the 3 effects elicited by Ca2+i, suppression of IA was most sensitive to Ca2+i elevation. Previous results (Numann et al., 1987) showed that IA had a lower threshold (about -45 mV) than sustained currents (about -40 mV). By using low levels of depolarization (-40 mV), IA can be selectively activated, and the suppressive effect of Ca2+i on IA was confirmed on the kinetically isolated IA.(ABSTRACT TRUNCATED AT 250 WORDS)     

Treatment of ulcerative colitis by traditional Chinese medicine and dynamic study of immune functions

The effect of the traditional Chinese medicinal herbs enema and enteric-coated capsules in the treatment of ulcerative colitis (UC) were compared in 260 cases. The immune complexes and the dynamic change of autoantibodies were monitored in 28 out of the 260 cases before and after treatment. The following results were observed. (1) There was no significant difference in the total effective rate between the enema group and the oral capsule group (93.3% and 87.5% respectively), but the recovery rates of purulent hemafecia, mucusfecia and erosion accompanying colitis, etc. in the former group were higher than those in the latter (P less than 0.01). (2) The circulating immune complexes were found 43 times above the normal range in 17 cases with positive rate 60.7%, and tended to decrease as the condition became better after treatment. Antinuclear antibodies were determined by the indirect fluorescent immune method and the indirect enzyme labelling method and the positive rates were 53.6% and 64.7% respectively, both being much higher than those in the controls (P less than 0.01).     

应用膀胱三角区壁瓣成形尿道治疗女性外伤性尿道缺损(附5例报告)

目的：探讨膀胱三角区壁瓣成形尿道治疗女性外伤性尿道损伤的疗效。方法：自膀胱颈后唇向上，取梯字形壁瓣，形成锥状管，经膀胱颈口，自阴道前壁外拉至外阴部，在原尿道外口处固定，替代尿道。结果：3例随访8年，1例6年，1例5年，平均随访7年，均排尿通畅，无尿失禁和尿道狭窄。结论：女性外伤性尿道缺损，应用膀胱三角区壁瓣形成锥状管替代尿道法治疗，手术简单，对患者打击小，成功率高，远期效果好。     

自拟威秦麻细蠲痹汤治疗风寒湿性关节痛临床报告

目的：用威秦麻细蠲痹汤内服，合药渣煮水加50度白酒泡足局部热敷治疗风寒湿性关节痛45例病人，具有祛风除湿、温经通络、调节机体促进康复。方法：以威秦麻细蠲痹汤为基本方一日一剂，根据临床发病部位及风、寒、湿的偏胜而辩证加减，配合荮渣煮水加50度白酒泡足和疼痛部位热敷，七天为一疗程．结果：45例病人中治愈71．1％：有效24．4％；显效4．5％；无效为0；总有效率100％，疗程最短的二周；最长为5周；平均21天。结论：威秦麻细蠲痹汤内服配合药渣外敷及泡足和热敷疗法共奏祛风除湿、散寒止痛，益气活血之功效，使机体气充血旺，营卫复常；血行风灭，温经散寒，脾健湿去而形成通则不痛，荣则不麻不酸的良性循环，疗效满意．     

核磁共振法测定非离子表面活性剂 HLB 值的研究 2.几种混合体系 HLB 值的测定与计算

本文应用核磁共振法(NMR)测定了几种混合体系的 HLB 值与混合体系中各组分的 HLB 值。实验结果表明,混合体系中各组分在核磁共振图谱中的积分曲线高度也具有加和性。混合体系的 HLB 值是体系中各组分 HLB 值的加权平均值。因此,对混合体系的 HLB 值可以应用 NMR 法直接测定,也可应用 NMR 法测定各组分的 HLB值,通过计算求得,计算值与实测值完全一致。