Pharmacological studies on the bungarotoxins: separation of the fractions and their neuromuscular activity

A commercial sample of Bungarus multicinctus venom was separated into its constituent fractions by column chromatography on CM-Sephadex C-50. The fractions were tested on the responses of the chick biventer cervicis preparation to nerve stimulation, and to added acetylcholine and carbachol.13 fractions were obtained: 1 was inactive, 4 exhibited weak postjunctional neuromuscular blocking activity, 3 had potent postjunctional blocking activity, and the remaining 5 fractions exhibited predominately prejunctional blocking activity. Use of higher concentrations of the prejunctional toxins revelead that 2 of these fractions also possessed some postjunctional blocking activity.Because small differences in separation procedures may result in differences in the elution pattern of the venom, and because some fractions may possess nonspecific actions only obvious at high concentrations, it is suggested that, when using venom components as experimental tools, the separation method is detalied and the fractions thoroughly tested.     

Determination of methotrexate and its major metabolite 7-hydroxymethotrexate in mouse plasma and brain tissue by liquid chromatography-tandem mass spectrometry

Methotrexate (MTX) is an anticancer agent that is widely used in a variety of human cancers including primary central nervous system lymphoma (PCNSL). Important pharmacological properties that directly bear on the use of MTX in PCNSL, such as mechanisms that govern its uptake into brain tumors, are poorly defined, but are amenable to investigation in mouse models. In order to pursue such preclinical pharmacological studies, a rapid and sensitive liquid chromatography-tandem mass spectrometry (LC/MS/MS) method for the determination of MTX and its metabolite, 7-hydroxymethotrexate (7-OH MTX) in plasma and microdialysate samples from brain tumors and cerebrospinal fluid (CSF) is needed. The plasma assay was based on 10 μl samples and following a protein precipitation procedure enabled direct injection onto a LC/MS/MS system using positive electrospray ionization. A column switching technique was employed for desalting and the clean-up of microdialysate samples from brain tissues.

The methods were validated for MTX and 7-OH MTX in both plasma and microdialysate samples from brain tumor and CSF, and produced lower limits of quantification (LLOQ) in plasma of 3.7 ng/ml for MTX and 7.4 ng/ml for 7-OH MTX, and in microdialysate samples of 0.7 ng/ml for both MTX and 7-OH MTX. The utility of the method was demonstrated by estimation of pharmacokinetic (PK) and brain distribution properties of MTX and 7-OH MTX in conscious mice. The method has the advantages of low sample volume, rapid clean-up, and the simultaneous measurement of MTX and 7-OH MTX in plasma and brain tissues allowing detailed PK studies to be completed in individual mice.     

顶空气相色谱法测定舒萨林中残留溶剂含量

目的：用顶空气相色谱法测定舒萨林中乙醇、异丙醇、乙酸乙酯有机溶剂残留量。方法：利用顶空气相色谱法,在大口径弹性石英毛细柱上进行各组分分离,各组分间的分离度均符合要求。柱温：80℃;进样口温度：200℃;检测器温度250℃。顶空瓶平衡溫度80℃平衡时间30分钟。结果：平均回收率：乙醇100.8%异丙醇101.2%乙酸乙酯100.5%。结论：该方法利用顶空气相色谱法克服了各组分分离度达不到要求的缺点,重现性好,精度高。     

Isolation and determination of lipophilic mycochemicals from a New Zealand edible native mushroom Hericium novae-zealandiae

Hericium novae-zealandiae is a native mushroom consumed by indigenous Māori people in New Zealand. The lipophilic mycochemicals of the mushroom were isolated using a normal column chromatography combined with a preparative HPLC. Structural characterisation based on spectroscopic methods, namely UV, MS, NMR and single crystal XRD have identified three lipophilic compounds as hericene B (a compound unique to Hericium), ergosterol and ergosterol peroxide. Following this, an HPLC-DAD method was developed and validated to quantify the hericene B and ergosterol. The method showed excellent selectivity, linearity, precision, accuracy and robustness. The content of hericene B was determined as 28.53 mg/g by dry weight of H. novae-zealandiae (approximately 3%). This discovery indicates the potential utilisation of H. novae-zealandiae as a natural source of hericene B. Current research revealed for the first time, the lipophilic constituents of H. novae-zealandiae and the method development for quantification of hericene B in the above species.     

Evaluation of an International Pharmacopoeia method for the analysis of ritonavir by liquid chromatography

A gradient LC method for the determination of related substances in ritonavir (RTV) has been recently published in the International Pharmacopoeia. The method uses a base-deactivated reversed-phase C18 column kept at a temperature of 35 degrees C. The mobile phases consist of acetonitrile, phosphate buffer pH 4.0 and water. UV detection is performed at 240 nm. A system suitability test (SST) is described to govern the quality of the separation. Since no brand names of columns are mentioned in pharmacopoeial texts, analysts often have problems to select a suitable stationary phase which is only described in general terms. So, the separation towards RTV components was investigated on 18 C18 columns and correlation was made with the column classification system developed in our laboratory. The method was further evaluated using a Hypersil BDS C18 column (25 cm x 4.6mm i.d.), 5 microm, which was also used for the development of the method. A central composite design was applied to examine the robustness of the method. The method shows good precision, linearity, sensitivity and robustness. Four commercial samples were examined using this method.     

Trauma to the medial ray of the foot: A classification of patterns of injury and their management

AimsFractures and dislocations of the midfoot are relatively uncommon but can be life changing injuries. Within the literature, there has been scant specific reference to the identification and management of medial ray injuries in midfoot trauma. Moreover, it is appreciated that these injuries are associated with poor outcomes. We aim to clearly define these injury characteristics and demonstrate fixation techniques.Patients and methodsA retrospective review of the case notes and imaging was conducted for operatively treated midfoot injuries between January 2013 and January 2018.Results161 patients were identified, 31 of these with imaging and operative diagnosis suggestive of medial ray injury. Studying these 31 injuries revealed five patterns of injury.ConclusionWhen treating midfoot trauma, it is important to fully understand the injury pattern as this dictates the principles and techniques of fixation. Identification and knowledge of these five injury patterns will aid surgeons in future management of these injuries and may improve treatment outcomes.     

脊柱结核的影像学诊断价值及临床分析

目的探讨脊柱结核的影像学（CR或DR、CT及MRI）诊断价值并进行临床分析。方法对68例经临床手术或病理证实且影像学资料完整的脊柱结核进行分析。结果中心型40例;边缘型16例;韧带下型7例;附件型5例。CR（DR）显示：椎体溶骨性骨质破坏55例,椎间隙变窄60例,椎旁梭形软组织密度影22例,脊柱后突畸形31例。CT显示：椎体穿凿样骨质破坏12例,边缘破坏30例,附件破坏12例,椎旁软组织块影46例;MRI显示：椎体呈斑片状或弥漫性长T1、长T2信号影38例;椎旁软组织块影38例;椎间隙变窄32例;脊柱后突畸形30例,脊髓水肿12例。结论影像学对脊柱结核的诊断具有特征性,对临床治疗、评价疗效具有重要价值。     

中国科学引文数据库来源期刊微信公众号现状调查与分析

【目的】全面了解我国科技期刊微信公众号现状,为更多期刊应用微信技术积累可资借鉴的经验。【方法】以2015—2016年度中国科学引文数据库来源期刊为样本,采用手机搜索法,结合期刊网站、纸质期刊等公告信息的浏览,从中选出271个科技期刊微信公众号为讨论源刊,并于2015年6月进行为期一个月的手机应用测试。【结果】多数微信公众号基本资料展示良好,特色创新服务有所体现;按“对话框式”“消息推送式”“分类导航式”及“分类导航+消息推送式”等四种情形进行讨论。其中,“分类导航+消息推送式”是目前最优服务方式;今后应注意栏目设置与内容优化、创新服务项目开发以及多刊共用微信号等问题,基本资料展示要准确、简明、易记。【结论】微信公众号是科技期刊宣传推广的新途径,必须得到重视。     

红景天甙的制备工艺改进

本文报道红景天甙的制备工艺,首次将聚酰胺、反相大孔树脂、硅胶及葡聚糖凝胶四种柱层析组合使用,成功地从大花红景天醇提物里制备出克级水平的红景天甙。     

黄芩中汉黄芩素的提取制备

为建立制备大量高纯度汉黄芩素的方法,将中药黄芩50g用pH 5水水解12h,再用95％的乙醇提取,得到的提取物浸膏,过30～60目的聚酰胺树脂柱纯化,将含有汉黄芩素的洗脱物采用高速逆流色谱（HSCCC）进行分离.通过该方法制得汉黄芩素525mg,纯度为98.7％.