Objective To explore the selection and clinical effects of internal or external drainage for upper urinary tract obstruction complicated with acute renal failure.Methods A total of 25 cases of upper urinary tract obstruction complicated with acute renal failure were treated with double J(DJ) tube internal drainage(12 cases,15 times) or percutaneous nephrectomy(PCN) external drainage(19 cases,23 times).15 cases of obstruction were induced by tumor and 10 cases of obstruction induced by benign disease.Results The drainage treatments were performed successfully in 23 cases,with the success rate of PCN and DJ drainage being 86.9%(20/23) and 60.0%(9/15),respectively.Postoperative bleeding occurred in 1 patient with PCN.Conclusions PCN is superior to DJ in the treatment of malignant obstruction,but DJ internal drainage may be the first choice for non-malignant obstruction.

Objective To explore the mechanism of β-amyloid peptide (β-AP) in Alzheimer's disease at ionic channel level.Methods Hippocampal CA1 neurons of 7-21 days' rats were acutely dissociated and the effects of β-AP on transient outward potassium current were observed by a whole-cell recording patch clamp technique.Results β-AP can significantly block transient potassium current in dose-dependent, time-dependent and partly voltage-dependent manners.Conclusion β-AP may decrease the membrane conductance of K+ channels in hippocampal neurons, playing an important role in the pathophysiological mechanism of Alzheimer's disease.