The updated electrostatic potential for cytosine completes the qualitative explanations of base alkylation regiochemistry

The relationship between the structures of different alkylatingagents and the relative extents to which they modify the oxygenand nitrogen centers of nucleic acid bases has been discussedin the literature from several points of view, although eacheffectively attributes the increasing preference for oxygenalkylation to the increasing importance of electrostatic interactionsbetween the reacting moieties. This is in direct contradictionto the published electrostatic potential data for cytosine whichindicate the most attractive potential to lie in the vicinityof the 3-nitrogen. However, we have discovered the latter tobe an artefact of the use of inadequate levels of theory. Whenthe electrostatic potentials of cytosine are computed usingmore sophisticated ab initio Hartree-Fock/6–31G^* calculationsthe global minimum does indeed lie in the vicinity of the O²-positionas required by the various rationalizations of the alkylationdata.     

CT导引下肝肾囊肿抽吸硬化治疗

目的：总结CT导引下肝肾囊肿穿刺抽吸硬化治疗的疗效和操作经验。材料和方法：肝囊肿11，肾囊肿15例，多囊肾1例，囊肿大小为3．5－12cm，均用15cm长20GGreene针穿刺治疗，抽出囊液量为21－550ml，囊液抽净后注入99．7％的无水酒精。结果：治疗后症状均有明显好转或消失，本组随访肝囊肿7例、肾囊肿11例，疗效指数I级1例（多囊肾），Ⅱ级肝肾囊肿各2例，Ⅲ级肝囊肿5例肾囊肿8例。穿刺操作顺利，无严重并发症发生。结论：CT导引下肝肾囊肿抽吸硬化治疗操作简便、创伤小、疗效高可作为替代外科手术的有效的治疗方法，多囊肾的单纯抽吸治疗可明显减轻症状，改善肾功能，是一种较好的治疗手段。     

缺血性脑血管病患者载脂蛋白B基因多态性与血脂关系探讨

应用聚合酶链反应（ＰＣＲ），检测了１０６例正常汉族人及５５例缺血性脑血管病（ＩＣＶＤ）病人的ａｐｏＢ基因ｘｂａⅠ酶切位点限制性片段长度多态性（ＲＦＬＰｓ）及其与血脂的关系。结果表明ＩＣＶＤ组ｘｂａⅠ酶切位点上Ｘ＋的等位基因频率明显高于正常对照组（Ｐ＜０．００５）；ＩＣＶＤ组中具Ｘ＋Ｘ－基因型者的血浆ＨＤＬ－Ｃ较Ｘ－Ｘ－基因型者明显降低（Ｐ＜０．０５），而ＬＰ（ａ）和ＴＣ明显增高（Ｐ＜０．０５～０．００５）。提示ａｐｏＢ基因多态分析结合血浆脂蛋白测定更能有效地检测ＩＣＶＤ易患人群。     

外周血及移植肾内嗜酸性粒细胞变化的临床意义

为了解移植肾在急性排斥时外周血和移植肾内嗜酸性粒细胞（ＥＯ）变化的意义，动态观察３１例同种异体肾脏移植病人的外周血和移植肾内ＥＯ的变化。结果发现在急性排斥反应时，移植肾内ＥＯ数＞２％者占８０．９％，明显高于肾功能稳定时，Ｐ＜０．０１；重度排斥中血ＥＯ数＞４％者占８２．６％，明显高于肾功能稳定时和中度以下排斥者，Ｐ＜０．０１。结果认为，测定移植肾内的ＥＯ变化可以做为监测急性排斥反应的可靠指标，外周血中的ＥＯ明显增多常提示排斥反应较为严重。     

儿科住院病人药物不良反应监测

通过4家医院儿科病人为期1年的药物不良反应协作监测，对1856例住院病人的药物不良反应进行前瞻性观察。发现107例发生了药物不良反应，发生率为5．8％。其中A型反应79例（73．8％），B型28例（26．2％）。药物不良反应致停药者48例，需处理者31例，致死者1例。因药物不良反应致住院者27例、不良反应发生率与庄院时间，共用药物数量，疾病构成有关。小儿某些生理特征对药物不良反应发生有显著影响。     

人左、右心室阻抗微分心动图的比较研究

作者利用Ⅱ导心电图、心音图、颈动脉搏动图、右（或左）心室阻抗微分心动图同步描记的方法。对人左、右心室阻抗微分心动图进行了比较分析。结果显示:人的左、右心室阻抗微分心动图图形相似，波形稳定，转折明显，均有清晰的生理标志点。两种图形各相应生理标志点在时相上存在着区别．且人的左、右心室阻抗微分心动图能分别反映人的左、右心室收缩和舒张过程，说明利用人的左、右心室阻抗微分心动图能分别测定人的左、右心室收缩时间间期与舒张时间间期值，鉴别和评定左、右心室的功能。     

Blood flow variation and energy metabolism in the gastric mucosa following 7．5％ hypertonic saline resuscitation

Ｂｌｏｏｄｆｌｏｗｖａｒｉａｔｉｏｎａｎｄｅｎｅｒｇｙｍｅｔａｂｏｌｉｓｍｉｎｔｈｅｇａｓｔｒｉｃｍｕｃｏｓａｆｏｌｌｏｗｉｎｇ７．５％ｈｙｐｅｒｔｏｎｉｃｓａｌｉｎｅｒｅｓｕｓｃｉｔａｔｉｏｎＷａｎｇＪｕｎｙｉ（王俊义）；ＷｕＧｕｏｓｈｅｎｇ；（吴...     

药物浓度和病因对三磷酸腺苷治疗阵发性室上性心动过速的影响

本文报告23例次ATP治疗PSVT的效果,总有效率56.5％,9例次高浓度快速注射者8例转复。器质性心脏病者副作用较多,1例冠心速注高浓度ATP后,发生心室颤动和阿-斯氏综合征。这一结果提示:药物浓度和注射速度是影响疗效的主要因素,PSVT伴AVB者疗效也很低;病因和药物浓度是决定副作用的因素。因此,对于器质性心脏病者,尤其冠心病人,应避免高浓度快速静脉注射ATP。     

用Logistic曲线求月经初潮均龄

介绍用Logistic 曲线来计算初潮均龄及95%可信区间,该方法只需原始数据即可进行计算,不必将来潮率以概率单位置换,从而避免了年龄与发生率的S 形曲线与正态分布函数相符这一要求。经验证和比较,认为本方法计算简便,误差小,是一种值得采用的方法。     

Comparison of the enzymatic and edema-produscing activities of two venom phospholipase A2 enzymes

The edema-producing activity of NNAVPLA₂, an acidic phospholipase A₂ (PLA₂) enzyme from Naja naja atra venom (NNAV), was less potent than that of TMVPLA₂ II, a basic PLA; from Trimeresurus mucrosquamatus venom (TMV). These edema-forming effects were greatly suppressed by pretreatment of rats with diphenhydramine/ methysergide or compound 48/80, which reduced the tissue content of histamine and serotonin. Heparin abolished and suppressed the paw edema caused by protamine and TMVPLA₂ II, respectively, but had no effect on the NNAVPLA₂-induced response. In isolated rat peritoneal mast cells, both PLA₂ concentration dependently induced the release of histamine and β-glueuronidase. Again, TMVPLA₂ II was more potent than NNAVPLA₂. This degranulation effect of mast cells caused by TMVPLA₂ II and protamine was inhibited by heparin, while that caused by NNAVPLA₂ was unaffected. The edema-forming and mast cell degranulation effects were greatly decreased in both PBPB-modified NNAVPLA₂ and PBPB-modified TMVPLA₂ II, in which the catalytic activity of the enzymes was completely lost. PBPB-modified TMVPLA₂ II-induced paw edema was also suppressed by heparin. Furthermore, this edematous response was totally reversed in rat pretreated with aspirin in combination with diphenhydramine and methysergide. These results suggest that the edema-forming effect of PLA₂ is probably dependent on the presence of catalytic, positive charge and pharmacological sites on its molecule.