Is magnesium neuroprotective following global and focal cerebral ischaemia? A review of published studies.

Neuroprotective activity with magnesium associated with animal models of cerebral ischaemia, seizure, perinatal hypoxia/ischaemia, subarachnoid haemorrhage and traumatic brain injury has provided the justification for clinical stroke trials. However, the recent IMAGES stroke clinical trial found magnesium to be largely ineffective. Hence, due to the negative stroke trial outcome, current FAST-MAG trial and our own experience with magnesium in cerebral ischaemia animal models, we thought it prudent to review these preclinical and clinical studies. We reviewed nine studies describing the use of magnesium following global cerebral ischaemia and fourteen following focal cerebral ischaemia. Four global ischaemia and six focal ischaemia studies did not show a significant neuroprotective effect with magnesium. In the majority of positive magnesium studies animal body temperature was not monitored post-ischaemia. Thus the effects of post-ischaemic hypothermia cannot be ruled out as a confounding factor in positive magnesium cerebral ischaemia studies. Moreover, data from our own laboratory indicates that magnesium is only neuroprotective when combined with post-ischaemic hypothermia. These data provide a possible explanation of why the IMAGES trial was largely unsuccessful, as current stroke patient management does not involve hypothermia induction. Future preclinical and clinical cerebral ischaemia trials with magnesium should consider combining treatment with mild hypothermia.     

A comparative study of using comet assay and gammaH2AX foci formation in the detection of N-methyl-N'-nitro-N-nitrosoguanidine-induced DNA damage.

Comet assay is a useful technique in the detection of DNA damages, particularly DNA strand breaks; and it has been utilized to show that a potent carcinogen N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), can induce such damages. Recently, gammaH2AX foci formation has been suggested as another sensitive way to detect DNA double strand breaks (DSBs). However, there is no systematic comparison being conducted to evaluate the consistency of these two methods. Using MNNG as a model chemical, the sensitivity of neutral comet assay and gammaH2AX foci formation in detecting MNNG-induced damage was studied. It was found that at concentrations of 0.1 and 1 microg/ml, both methods can detect MNNG-induced damage in human amnion FL cells. However, at 0.1 microg/ml, comet assay revealed more percentage of cells with DNA damage than gammaH2AX fluorescence revealed. On the other hand, while gammaH2AX foci were readily formed at very early times by 10 microg/ml MNNG treatment, neutral comet assay did not detect any significant DNA damage at the same time points. In addition, 10 microg/ml MNNG induced a distinct whole nuclei staining pattern of gammaH2AX, a type of DNA damage which was not detected by neutral comet assay but could be detected by alkaline comet assay. Therefore, gammaH2AX may be used as a sensitive indicator for DNA damage.     

从SARS流行看医院危机管理

医院是一个高风险的组织，在复杂、多变的市场环境中，危机是一种连续发生的常态。要借鉴SARS危机管理的经验教训，树立预警性反危机理念，尽量减少危机发生。要提高医院危机管理能力和水平，尽量减少危机造成的损害。要善于把危机变成推动医院发展的契机。     

微波干燥法对腊叶标本压制的实验研究

目的：寻求一种不受气候条件影响而能成功制作腊叶标本的新技术。方法：采用微波干燥法，即用微波炉，由创制的直径31cm瓦楞纸板、吸水纸与玻璃皿组成的压制程序进行微波干燥。结果：微波干燥法可用于腊叶标本压制，且优于传统的常规腊叶标本压制方法。结论：本研究为腊叶标本的制作提供了一个新方法，收到了便捷、高效、且保色的理想效果。     

兔女郎的前世今生

《花花公子》杂志曾经是西方性解放运动的产物，这本杂志及其创办的兔女郎俱乐部在相当长的时期里曾经影响着西方上流社会的生活，成为著名的声色享乐之地。     

新的高强度高选择性阿片μ受体激动剂[11C]-羟甲芬太尼的合成

羟甲芬太尼(I)是一个新的高强度高选择性阿片μ受体激动剂。本文用cis-A-N-[1-(2-羟基-2-苯乙基)-3-甲基-4-哌啶基]-苯胺(II)或cis-N-[1-(苯甲酰甲基)-3-甲基-4-哌啶基]-苯胺(III)作为前体合成了[¹¹C]-羟甲芬太尼,以便用正电子发射断层扫描(PET)来观察μ受体。通过水解cis-A-羟甲芬太尼(I)和cis-N-[1-(苯甲酰甲基)-3-甲基-4-哌啶]-N-苯基丙酰胺(cis-IV)的4-N-丙酰基分别获得II和III。溴乙烷的格氏试剂与回旋加速器产生的[¹¹C]-二氧化碳反应后继而直接加入邻苯二甲酸二酰氯和2,6-二叔丁基吡啶生成同位素标记中间体[¹¹C]-丙酰氯。[¹¹C]-丙酰氯与OH-前体(II)反应后再经HPLC分离纯化直接得[¹¹C]-羟甲芬太尼;[¹¹C]-丙酰氯与酮-前体(III)反应后,再用硼氢化钠甲醇溶液处理,然后进行HPLC分离纯化得[¹¹C]-羟甲芬太尼。两种方法均可获得ll.1～14.8GBq/μmol的特异性放射化学纯[¹¹C]-羟甲芬太尼。总共耗时为40～50min(EOB)。     

氧化应激诱导神经细胞凋亡与c-Myc、Fas-FasL、核因子-κB关系的研究

目的　探讨氧化应激诱导神经细胞凋亡与c -Myc、Fas -FasL、核因子 -κB(NF -κB)蛋白表达的关系。　方法　将分离培养的新生SD大鼠大脑皮质神经细胞分为 :A组 (对照组 )、B组 (缺氧处理 )、C组 (低浓度H2 O2 处理 )、D组 [缺氧 +超氧化物歧化酶 (SOD)处理 ]、E组 (H2 O2 +SOD处理 ) ,利用琼脂糖凝胶电泳、末端脱氧核苷酸介导的X -dUTP缺口末端标记法 (TUNEL)、流式细胞仪测定细胞凋亡 ,免疫组织化学方法 (SP法 )测定细胞c -Myc、Fas -FasL、NF -κB蛋白表达。结果　B组和C组神经细胞凋亡率分别为A组的 6倍和 8倍 (P <0 .0 1) ;A组c -Myc、Fas-FasL、NF -κB阴性表达 ,其余各组均有阳性表达 ;SOD在降低B组和C组细胞c-Myc、Fas-FasL、NF -κB表达强度的同时 ,细胞凋亡率也随之降低。　结论　氧化应激诱导神经细胞凋亡可能与NF -κB的激活 ,启动凋亡相关基因c -Myc、Fas -FasL有关。     

霍奇金淋巴瘤组织中H／RS细胞与其背景细胞的微切割及其IgH基因重排检测

目的 从基因水平探讨霍奇金淋巴瘤(HL)组织中H／RS细胞(Hodgkin and Reed-Sternberg cells)是否起源于B细胞、H／RS细胞的克隆性以及与背景淋巴细胞的相互关系。方法 对33例经典霍奇金淋巴瘤(cHL)石蜡刮片组织进行IgH基因重排分析，并对其中6例重排阳性的病例经B细胞特异性激活蛋白(BSAP)免疫标记，将标记阳性的H／RS细胞和背景淋巴细胞进行微切割后进一步行IgH基因重排分析。结果 16例石蜡刮片组织IgH基因重排阳性。对6例经BSAP标记的cHL成功进行了微切割，其中19管H／RS细胞中，有14管出现重排阳性，细胞数目不同的各管阳性率无显著性差异(P=0．290)；12管背景淋巴细胞有2管出现重排阳性，H／RS细胞与背景淋巴细胞的阳性率有显著性差异(P=0．002)。结论 支持H／RS细胞来源于B细胞的理论，认为部分背景淋巴细胞可能具有瘤性增生活性，参与H／RS细胞的前体细胞组成。     

Synthesis of CCK-8 Tetrapeptide Fragment by Enzymatic Method

Cholecystokinin (CCK )isa polypeptidehor monecontaining 33aminoacidsresiduewithgastroin testinal,biliarandbrainactivities Itiswidelydis tributedinthevertebratecentralnervoussystem ,anditcanstimulateextensivelytheliberationofinsulinandglucagonfromtheLangerhansislets GreateffortshavebeendevotedtothesynthesisofCCK 8,itsderivativesandanalogues Amongthedifferentmethods ,theenzymaticmethodisthemosteffectiveonewithmanyadvantagesoverconventionalchemicalmethodologies :enzymespecificitysuppress essid…     

开（牙合）患者舌位置变化研究

目的：研究开He患者的舌位置有无特征性变异。方法：利用舌背碘油造影方法，增加头颅侧位定位X线片上舌背的显影效果，在头颅侧位定位X线片上以舌体在固有口腔内的相对位置确定舌体的位置，通过开He与正常He者知位置的团体t检验比较，找出开He患者的舌位置变异特性。结果：开He患者与正常He者比较，舌根部与悬雍垂之间的间隙增大，舌背部与腭表面之间的间隙减小，舌尖部更靠近牙齿，结论：开He个体相对于正常He个体舌位置有向前，向上的变化特点，这可能是开He的病因之一。