Temperature-dependent pharmacokinetics and pharmacodynamics of vecuronium

BACKGROUND: The authors evaluated the influence of temperature on the pharmacokinetics and pharmacodynamics of vecuronium because mild core hypothermia doubles its duration of action. METHODS: Anesthesia was induced with alfentanil and propofol and maintained with nitrous oxide and isoflurane in 12 healthy volunteers. Train-of-four stimuli were applied to the ulnar nerve, and the mechanical response of the adductor pollicis was measured. Volunteers were actively cooled or warmed until their distal esophageal temperatures were in one of four ranges: < 35.0 degrees C, 35.0-35.9 degrees C, 36.0-36.9 degrees C, and > or = 37.0 degrees C. With temperature stabilized, vecuronium was infused at 5 microg x kg(-1) x min(-1) until the first response of each train-of-four had decreased by 70%. Arterial blood (for vecuronium analysis) was sampled at intervals until the first response recovered to at least 90% of its prevecuronium level. Vecuronium, 20 microg x kg(-1) x min(-1), was then infused for 10 min, and arterial blood was sampled at intervals for up to 7 h. Population-based nonlinear mixed-effects modeling was used to examine the effect of physical characteristics and core temperature on vecuronium pharmacokinetics and pharmacodynamics. RESULTS: Decreasing core temperature over 38.0-34.0 degrees C decreases the plasma clearance of vecuronium (11.3% per degrees C), decreases the rate constant for drug equilibration between plasma and effect site (0.023 min(-1) per degrees C), and increases the slope of the concentration-response relationship (0.43 per degrees C). CONCLUSIONS: Our results show that reduced clearance and rate of effect site equilibration explain the increased duration of action of vecuronium with reducing core temperature. Tissue sensitivity to vecuronium is not influenced by core temperature.     

Primary right atrial synovial sarcoma manifesting as transient ischemic attacks

Primary tumors of the heart are rare and most of them benign. The majority of benign cardiac tumors are myxomas while almost all malignant cardiac tumors are sarcomas. We present a case of primary right atrial synovial sarcoma, a form of sarcoma particularly rare in the heart. The tumor manifested clinically as transient ischemic attacks probably related to a patent foramen ovale allowing paradoxical tumor embolization.     

荨麻水溶性化学成分研究

 目的 研究荨麻的水溶性化学成分。方法 运用大孔树脂、聚酰胺柱色谱、硅胶柱色谱等方法对荨麻水溶性化学成分 进行分离;运用UV,IR,MS,NMR等方法进行结构鉴定。结果 从荨麻全草中分离并鉴定了7个化合物,分别为硝酸钾(potassi- um nitrate,Ⅰ)、异鼠李素(isorhamnetin,Ⅱ)、山柰酚-7-O-β-D-吡喃葡萄糖苷(kaempferol-7-O-β-D-glucopyranoside,Ⅲ)、槲皮素-7-O-β-D-吡喃葡萄糖苷(quercetin-7-O-β-D-glucopyranoside,Ⅳ)、异鼠李素-3-O-β-D-芸香糖苷(isorhamnetin-3-O-β-rutinoside,Ⅴ)、3,5-二 咖啡酰奎宁酸(3,5-di-O-caffeoylquinic acid,Ⅵ)、芦丁(rutin,Ⅶ)。结论 化合物Ⅱ-Ⅶ均为首次从荨麻中分得,其中Ⅳ,Ⅴ为首 次从荨麻属中分得。     

国际多中心临床试验的监查

为贯彻临床试验管理规范，保证多中心临床试验的质量。本文以ADVANCE多中心临床试验为例，简介监查的程序和方法。提出监查员应当具有医药知识和临床试验经验，应当按程序到研究点去核查CRF，研究文件和有关资料。标准化的监查有助于提高多中心临床试验的质量。     

A systematic review to determine the reliability of knee joint position sense assessment measures

BackgroundThe assessment of joint position sense (JPS) is the most widely used measurement of knee proprioceptive capability within the literature. However, it remains unclear what the most reliable method is to assess this. The purpose of this study was to determine the intra- and inter-rater reliability of the various methods used to assess knee JPS.MethodsA systematic review of published and unpublished literature sources was conducted up to June 2012. All studies principally assessing the reliability (intra- or inter-rater) or reproducibility of a JPS of the knee were included. The methodological quality of each study was reviewed using the Critical Appraisal Skills Programme tool.ResultsA total of 18 studies were eligible, assessing the reliability of JPS with 456 knees. The reliability of four methods of JPS has been recorded: position replication using a model, image recorded angulation, electrogoniometry and dynamometry/angular motion chair. Intra-rater reliability was good for the assessment of JPS using photographs and digital images, and replicating knee position using a paper model, this was good but variable when electrogoniometry was used, and moderate but variable when assessed using dynamometry/angle motion chairs. The assessment of JPS by image recorded angulation, electrogoniometry and dynamometry/angular motion chair has demonstrated good inter-rater reliability.ConclusionsWhilst JPS methods appear to have variable reliability, the four assessment methods should be further assessed with pathological populations such as those following patellar dislocation or anterior cruciate ligament rupture. This will better facilitate the generalisability of JPS assessment methods to inform clinical practice.