苯丙胺诱发小鼠激怒反应及其机制

苯丙胺15mg/kg ip能诱发小鼠激怒反应,使小鼠出现攻击和殴斗行为。强安定药、弱安定药和利血平有明显拮抗效果。镇静剂如巴比妥类、抗胆碱药及抗肾上腺素药均无拮抗作用。金刚胺、左旋多巴和阿扑吗啡均能增强苯丙胺的激怒效应。因苯丙胺激怒小鼠的方法简便易行,可作为筛选抗精神病药的动物模型。苯丙胺产生激怒作用的机制与增强多巴胺能神经的功能有关,推测可能是促进边缘系统多巴胺释放的结果。     

Percutaneous removal of residual intrahepatic stones

In the Orient there is a high frequency of residual intrahepatic stones after biliary tract surgery. Percutaneous removal of residual intrahepatic stones was attempted in a group of 74 patients. Stones were exclusively intrahepatic in 57 patients, whereas 17 patients also had stones in the common bile duct. Biliary strictures were present in 60 cases (81%). A combination of techniques was used, including preshaped angulated catheters, irrigation-suction, balloon dilation of strictures, and crushing of large stones. In 36 cases all stones were removed and in 14 cases most stones were removed, for a success rate of 67.6%. Biliary stricture was the factor most often responsible for failure.     

Five‐year experience with tadalafil in the UK: an effective treatment for erectile dysfunction

Background: Erectile dysfunction (ED) is a common medical condition. In the UK, approximately 2.3 million men suffer from moderate‐to‐severe ED, many of whom do not consult a healthcare professional about the problem. Phosphodiesterase‐type 5 (PDE5) inhibitors have revolutionised treatment for ED and three such drugs are currently available: sildenafil citrate, tadalafil and vardenafil HCl. Methods: This article reviews available information on the efficacy and safety of tadalafil for the treatment of ED, with a focus on clinical experience in the UK. Results: The clinical effects of tadalafil have been shown to last for up to 36 h after administration, longer than the other PDE5 inhibitors, which are effective for only 4–5 h after dosing. Extensive clinical experience with tadalafil, worldwide and in the UK, supports its efficacy and tolerability in many patient populations, including those with comorbidities often associated with ED. Conclusions: Studies have shown that tadalafil is an effective ED treatment, regardless of disease severity and cause, patient age and presence of comorbid conditions. As the treatments for ED have evolved, patient preference has emerged as an important aspect of ED therapy.     

Pulmonary arteriovenous malformations: diagnosis by gradient-refocused MR imaging

Six known or suspected pulmonary arteriovenous malformations (AVMs) in four patients were evaluated with magnetic resonance (MR) imaging at 1.5 T. All lesions were imaged using a gradient-refocused echo pulse sequence with a 25/13 ms [repetition (TR)/echo (TE) times] and a 30 degrees flip angle, as well as with a cardiac-gated spin echo short TR/TE pulse sequence technique. Five of the lesions were vascular in nature based on their signal intensity characteristics, and one nonvascular lesion was a carcinoid tumor. On the spin echo images, the AVMs showed a central signal intensity void with a peripheral rim of intermediate signal intensity that was detectable for lesions greater than or equal to 1.5 cm in size. Smaller lesions were more difficult to distinguish from the surrounding air-filled lung, which normally generates no appreciable signal on MR images. The AVMs demonstrated uniform high signal intensity on the gradient echo pulse sequence and were more conspicuous, irrespective of size. With a single breath-hold scan, the vascular nature of the lesion could be rapidly confirmed with an acquisition time of 13 s. In three patients, the cine MR gradient echo images showed a pulsatile quality to the signal intensity in the lesion over the cardiac cycle similar to that within adjacent pulmonary vessels. The results of this study show a potential role for gradient echo MR imaging as a rapid, noninvasive method to evaluate the vascular nature of an atypical pulmonary nodule.