肾康宁片中黄芪甲苷的薄层扫描法测定

目的:建立肾康宁片中黄芪甲甙含量测定方法。方法:双波长薄层扫描法,经水饱和正丁醇液冷浸超声提取,再上D101大树脂纯化,以氯仿-甲醇-水(65:30:10)下层液为展开剂,检测波长为520nm,参比波长为700nm。结果:平均加样回收率为97.8％(RSD=1.4％,n=6),标准曲线r=0.9996。结论:方法结果可靠、操作简单,可作为肾康宁片的质量控制标准。     

Surgical management of pseudomembranous colitis

The authors recently studied two cases of pseudomembranous colitis (PMC) that required surgery and combined them with previously reported cases in the literature, which required surgery to propose guidelines for the surgical management of PMC. A total of 21 patients were studied. Indications for surgery included refractory disease in seven patients, toxic megacolon in 12 patients, and perforation in two patients. Operative management ranged from decompressive cecostomy to total proctocolectomy. The best results were obtained with subtotal colectomy and ileostomy. It is concluded that PMC should be managed surgically in a manner analogous to ulcerative colitis. If there is no improvement after 7 days of aggressive medical management, surgical intervention, ileostomy with subtotal colectomy is indicated to prevent complications. Complications of PMC, toxic megacolon and perforation, should also be managed with ileostomy and subtotal colectomy as simple decompression or segmental resection does nothing to alter the underlying disease process.     

Percutaneous endoscopic gastrostomy. New technique--old complications

Early reports support the percutaneous endoscopic gastrostomy (PEG) as an alternative to traditional gastrostomy with lower cost, greater ease of placement, and low morbidity and mortality. The authors' bias has been to attempt PEG on nearly all patients referred to gastrostomy tube prior to performing open gastrostomy. In this light, we reviewed our 32 month experience of 115 PEG placements in 112 adult patients, with a mean follow-up of 59.4 days. Placement was unsuccessful in ten per cent of patients and difficult in another six per cent. Minor postoperative complications not requiring intervention occurred in 9.5 per cent of patients, and major complications in 20 per cent. Infection was the most common postoperative problem. Thirty day mortality was 24 per cent. No patient died as a direct result of the procedure. The ten per cent failure rate is a consequence of attempting PEG as the initial procedure in greater than 90 per cent of patients. PEG can be employed as an initial procedure in even the sickest of patients with a high rate of success, and morbidity comparable to open gastrostomy. This knowledge allows early PEG placement in all types of patients, thereby facilitating their transfer to a non-acute care environment.     

压电频移中和萃取法测定微克量枸橼酸维静宁

用涂圈压电石英晶体频移一中和萃取法测定枸橼酸维静宁(咳必清),检出限0.02μg,在0.05～1.6μg范围内呈线性,相关系数0.999,变异系数为2.3%。与经典的中和萃取法相比,本法具有明显的优越性。     

Starting and stopping mechanisms of absence epileptic seizures are revealed by hazard functions

We show that the hazard function provides useful information about the starting and the stopping mechanisms of absence epileptic seizures. The hazard function quantifies changes in the probability that an event (respectively, the starting and the stopping of a seizure) occurs in some small time interval given that it has not occurred yet. It informs us about changes in the concentration of endogenous substances that modulate the neuronal signalling properties of (parts of) the brain. In a pharmacological experiment, we used the hazard function to study the effect of a GABA-transaminase inhibitor (vigabatrin) on the starting and the stopping mechanisms of absence epileptic seizures in a genetic rat model of absence epilepsy (the WAG/Rij rat). This experiment showed that a high GABA level changed the stopping mechanism of the absence epileptic seizures, creating much better conditions for very long seizures to develop. With respect to the starting mechanism, it was found that both with a high and a low GABA level, there was evidence for a recovery mechanism that decreases the probability that a new seizure starts. Initially, this probability is larger with a high GABA level, but gradually it converges to the same constant baseline probability as in the condition with a low GABA level.