Review: Biocatalytic transformations of ferulic acid: An abundant aromatic natural product

In this review we examine the fascinating array of microbial and enzymatic transformations of ferulic acid. Ferulic acid is an extremely abundant, preformed phenolic aromatic chemical found widely in nature. Ferulic acid is viewed as a commodity scale, renewable chemical feedstock for biocatalytic conversion to other useful aromatic chemicals. Most attention is focused on bioconversions of ferulic acid itself. Topics covered include cinnamoyl side-chain cleavage; nonoxidative decarboxylation; mechanistic details of styrene formation; purification and characterization of ferulic acid decarboxylase; conversion of ferulic acid to vanillin;O-demethylation; and reduction reactions. Biotransformations of vinylgualacol are discussed, and selected biotransformations of vanillic acid including oxidative and nonoxidative decarboxylation are surveyed. Finally, enzymatic oxidative dimerization and polymerization reactions are reviewed.     

二核苷酸重复多态性的非同位素检测及其在基因诊断中的应用

本文报道了一种检测二核苷酸重复多态性的简便的非同位素法,利用重复序列两侧的特异引物进行ＰＣＲ扩增,产生的等位片段在薄层变性聚丙烯酰胺凝胶电泳上分离,再用灵敏的银染法显色。该方法不需要标记ＰＣＲ产物,简便、快速,分辨率可达１ｂｐ,并可用多对引物同时进行多重ＰＣＲ分析。用此方法对ＤＭＤ家系成员ｄｙｓｔｒｏｐｈｉｎ基因的５＇－脑型外显子止游区和３＇－非翻译区的两个（ＣＡ）。位点进行了扩增片段长度多态性分     

使用MUG培养基定量检测植物药中大肠杆菌时荧光猝灭现象的发生与克服方法

实验中观察到,用ＭＵＧ培养基对植物药中的大肠杆菌定量时多发生荧光猝灭现象,影响检测结果。本文对此现象产生的原因与克服方法进行了系统的考察,发现以一种简便的转接方法可排除植物药介质对菌检的干扰。该方法由两组检验系列构成,当怀疑正常稀释系列（第一系列）４０ｈ培养液的荧光结果可能因猝灭现象呈假阴性时,立即分别将该系列的１—３号管培养液以０．５ｍｌ的接种量转接入新鲜的ＭＵＧ培养基（第二系列）,重新培养２４ｈ,荧光猝灭现象即可克服。综合两系列的荧光、产气和吲哚三项生化特征得出检品中大肠杆菌含量。实际应用表明,此法能显著提高使用该培养基时菌检结果的可靠性。     

CO2激光治疗慢性宫颈炎670例疗效观察

本文用ＣＯ２激光对６７０例慢性宫颈炎患者进行了治疗,经复查,治愈率９８％,有效率１００％。     

Bi（Ⅲ）与金属硫蛋白作用性质研究

 Ｂｉ（Ⅲ）与金属硫蛋白作用性质研究张保林,黄辉,朱凌燕,岳晟,唐雯霞（南京大学配位化学研究所,配位化学国家重点实验室,南京２１００９３）如何降低顺铂或其它抗癌铂的毒性,一直是癌症化疗中的重要课题之一,最近研究发现预先给大鼠或肺癌病人服用铋盐,可以极大...     

钙离子和蛋白激酶C对大鼠缺血海马脑片谷氨酸堆积的影响

采用大鼠海马脑片体外缺血模型观察钙离子和蛋白激酶Ｃ（ＰＫＣ）对神经元胞外谷氨酸（ＧＬＵ）堆积的影响,结果显示：海马脑片在体外“缺血”１０ｍｉｎ,ＧＬＵ在胞外的浓度增加４倍（从３２±４升高到１１３±１０ｐｍｏｌ／（ｍｉｎ．ｍｇＰｒ）．ｎ＝６）．Ｎ型钙通道拮抗剂蝙蝠葛苏林碱（ＤＳＬ）或无钙培养液均能有效抑制这种浓度的升高（Ｐ＜０．０１）．提示缺血１０ｍｉｎ引发的ＧＬＵ浓度升高是受Ｃａ２＋内流调控的．当脑片在缺血状况下孵育３０ｍｉｎ,ＤＳＬ只部分抑制这种ＧＬＵ堆积,而无钙培养液则无影响,但这额外的ＧＬＵ堆积可被ＰＫＣ抑制剂Ｈ－７完全阻断,而被ＰＫＣ激动剂ＰＤＢ所加强;且不受钙调蛋白抑制剂Ｃａｌｍｄａｚｏｌｉｕｍ和８－溴－ｃＡＭＰ影响．提示缺血３０ｍｉｎ,胞外ＧＬＵ的堆积受钙内流和ＰＫＣ双重调控。     

Evidence that 5-HT2 antagonism elicits a 5-HT3-mediated increase in dopamine transmission

Amperozide, a novel atypical antipsychotic drug with few extrapyramidal side effects, is a strong serotonin₂ (5-HT₂) antagonist but has low affinity for dopamine receptors in vitro. The effect of amperozide on the dopaminergic synapse was studied with an in vivo microdialysis technique using anesthetized male Sprague-Dawley rats. Following implantation of dialysis probes into the striatum and nucleus accumbens (NuAc), amperozide was intravenously infused as six consecutive incremental doses (0.5, 0.5, 1.0, 2.0, 4.0 and 8.0 mg/kg) at intervals of 15 min. From the beginning of drug infusion, perfusates were collected in fractions every 30 min throughout a total period of 120 min. The samples were then immediately analyzed by high-performance liquid chromatography with electrochemical detection. Amperozide induced a dose-related elevation of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindolacetic acid (5-HIAA) levels in both areas.p-Chlorophenylalanine (pCPA) pretreatment abolished the production of 5-HIAA in both areas and attenuated the amperozide-induced rise of DOPAC but not of dopamine. After pretreatment with an intravenous 5-HT₃ antagonist, MDL 72222, the amperozide-induced changes in dopamine, DOPAC and 5-HIAA in both areas were lower than in the saline control group. Preliminary data showed that afterpCPA pretreatment, incremental concentrations of the 5-HT₃ agonist 1-(m-chlorophenyl)-biguanide perfused via the probe also produced significant elevation of dopamine and DOPAC levels in these two areas. Taken together, these results suggest that amperozide may directly block 5-HT₂ receptors in the striatum and NuAc, thereby enhancing 5-HT transmission. The enhanced 5-HT transmission may activate postsynpatic 5-HT₃ receptors located on the dopaminergic terminals, leading to changes in dopamine transmission in these two areas.