Soft Drugs. XX. Design,Synthesis, and Evaluation of Ultra-Short Acting Beta-Blockers

A new type of ultra-short acting -blocker which might prove advantageous in treating acute arrhythmias was designed, synthesized and investigated. Based on the soft drug inactive metabolite approach, the inactive phenylacetic acid metabolite of both metoprolol and atenolol was reactivated by esterification with sulfur-containing aliphatic alcohols. Since the sulfur-containing moieties are labile to the ubiquitous esterases, the new compounds should be inactivated by a one step enzymatic cleavage back to the inactive phenylacetic acid derivative. Pharmacological and pharmacokinetic profiles of the new compounds were evaluated in rats and rabbits. Isoproterenol-induced tachycardia was inhibited with short-term infusion of each compound. This tachycardia blocking effect rapidly disappeared upon termination of infusion, while -blocking activity was 2–4-fold longer after comparable doses of the short-acting -blocker, esmolol. The rapid recovery from the -receptor blockade is believed due to fast hydrolysis of the soft drugs in the body. This is supported from in vitro results showing the t_l/2 of esmolol is about 10-fold longer than the new soft drugs in rat, rabbit, dog and human blood. Hydrolysis studies in phosphate buffered solutions indicated that the esters are labile to base-catalyzed hydrolysis. However, the relative t_1/2 values measured in biological media compared to phosphate buffered solution clearly support rapid enzymatic cleavage of the soft drugs. Interestingly, one of the soft -blockers, the sulfonyl ester derivative, showed a unique property of exhibiting good -receptor blocking activity without significant hypotensive action.     

经岩骨入路颈静脉孔区手术的显微解剖观测

目的：为获得经岩骨入路颈静脉孔区手术相关的国人解剖学参数,指导临床实践。方法：通过解剖观测３０ 侧国人尸头,对有关岩骨入路数据进行测量。结果：鼓环～颈静脉球顶距离为（４．８４±３．８４）ｍ ｍ ,鼓环～面神经距离为（２．７１±０．８１）ｍ ｍ ,后半规管～颈静脉球顶距离为（４．９９±４．４１）ｍ ｍ ,膝状神经节～颈内动脉膝部距离为（７．７１±１．４７）ｍ ｍ ,面神经垂直部～颈静脉球距离为（５．６７±２．２４）ｍ ｍ 。结论：术中如能注意相关解剖学参数,可提高治愈率,减少并发症和死亡率     

High Cervical Disc Lesions in Elderly Patients – Presentation and Surgical Approach

Summary  The incidence of high cervical disc lesions is extremely rare, and the mechanism of their development is unclear. We report these three cases, and discuss the possible mechanisms. We also describe surgical strategies for these lesions.  The first and second cases were an 82-year-old male and an 84-year-old male with retro-odontoid disc hernia. The third was an 83-year-old female with a herniated disc at C2/C3. To investigate Aetiological mechanisms of these lesions, we examined the findings on cervical images in extension and flexion, and compared the results in a younger than 80-year-old group and an older than 80-year-old group.  The patients underwent surgery via a posterolateral intradural approach. Wide laminectomy and incision of the dentate ligaments enabled access to the ventral space of the upper cervical spinal canal and sufficient decompression. All patients became ambulatory postoperatively without special fixation of the cervical spine. In the younger group, the level mostly loaded during cervical movement was C5/6, however, the levels in the older group were C2/3 and C3/4.  In elderly patients, less mobilization of the middle and/or lower cervical spine due to spondylotic change causes overloading at higher levels resulting in high cervical disc lesions. Retro-odontoid disc lesions can be caused by a herniated disc at C2/C3, which migrates upward. Regarding surgical strategy, the posterolateral intradural approach is less invasive and more advantageous for these lesions.     

Multiple intracranial aneurysms: A high risk condition

Summary There is still a relative silence in the literature on what policy should be followed in treating multiple aneurysms. The main risks are: bleeding of a formerly asymptomatic aneurysm during the haemodynamic tides of the peri-operative period; aneurysm(s) can be hidden on angiograms and tend to be overlooked easier in case of an already revealed aneursym; misjudgement of the ruptured one as a silent additional aneurysm, therefore left for second stage surgery.This paper, based on a material of 330 operations for multiple aneurysms, focuses on these problems. It advocates the one stage complete repair of all lesions using both options of bilateral pterional craniotomies or the contralateral approach. But it also describes those silent aneurysms which safely could be clipped later. Hazards and disadvantages concerning the more aggressive surgery proved to be less significant than the natural history of multiple aneurysms represents.Presented at the EANS Wintermeeting on High Risk Neurosurgery, Budapest, February 20–23, 1991.     

浅谈药用植物良种选育的目标和常规途径

针对传统药用植物的品质退化进行品质改良，选育优良品种，是优化中草药品质的根本途径。优质、高产、稳产、熟期适应、抗性强、适应性相对较广是各种药用植物育种的共同目标，但不同药用植物品种的侧重点和具体内容各有变化。在药用植物的良种选育工作中，确定育种目标是基础。通常用以下途径进行良种繁育：1．种质资源调查和收集；2．引种驯化；3．良种选育；4．建立良种繁育基地。     

颈静脉球解剖变异对经内镜行岩斜坡区病变手术的影响

目的 了解颈静脉球的解剖变异对颞骨径路在内镜下行桥小脑角区病变手术的影响。方法 在20例40侧成人尸头上模拟颞骨径路内镜手术,测量相关数据。结果 颈静脉球高度为左侧(7.39±2.11)mm,右侧(9.05±3.10)mm;宽度为左侧(6.28±1.25)mm,右侧(6.34±0.79)mm;颈静脉球顶距鼓室天盖、后半规管上、下缘、上半规管顶点、内淋巴囊上缘、面神经锥段中点、内听道下缘之间距离分别为:(16.05±3.34)mm、(8.73±3.11)mm、(3.13±1.83)mm、(14.63±3.33)mm、(5.01±2.88)mm、(3.70±3.36)mm、(5.03±3.19)mm。结论 高位颈静脉球对内镜手术有一定影响,但相对非内镜手术而言要小,高位颈静脉球的定义依不同的术式而不同。     

颞下经岩尖-小脑幕入路手术的显微解剖研究

目的 为颞下经岩骨入路手术处理斜坡及脑干腹侧病灶提供解剖学资料。方法 模拟颞下经岩尖—小脑幕入路的手术操作,在手术显微镜下对20侧(10具)福尔马林固定的国人成年带颈头颅标本进行解剖,并观测各主要解剖结构的相互关系。结果 颞下硬脑膜外经前内侧的三叉神经压迹、外侧的岩浅大神经沟及岩上窦所形成的三角区磨削岩骨尖。其周围结构的测量结果为:上半规管垂直于岩骨嵴,位于弓状隆起下方,耳蜗位于内听道前方、岩骨颈内动脉膝后方,内听道位于上半规管与岩浅大神经夹角中央。20侧中有2侧面神经膝裸露,耳蜗至膝状神经节的距离约为3.30 mm±0.79 mm,耳蜗距颈内动脉膝约2.48 mm±1.14 mm,内听道距岩斜缝约16.03 mm±1.94 mm,颈内动脉水平段距岩上窦约10.73 mm±2.00 mm。结论 颞下经岩尖—小脑幕入路能增加岩斜坡及脑干腹侧的显露,但显露范围有限,且需一定程度的颞叶牵拉。同时可能因为不熟悉解剖而误伤耳蜗、颈内动脉及第Ⅶ脑神经、第Ⅷ脑神经,选择应用时应审慎考虑。