Phosphorylation of p27BBP/eIF6 and its association with the cytoskeleton are developmentally regulated in Xenopus oogenesis

p27^BBP/eIF6 is an evolutionarily conserved regulator of ribosomal function. It is necessary for 60S biogenesis and impedes improper joining of 40S and 60S subunits, regulated by protein kinase C or Efl1p. No data on p27^BBP/eIF6 during early development of Metazoa are available. We studied the distribution, post-translational changes and association with the cytoskeleton of p27^BBP/ eIF6 during Xenopus oogenesis and early development. Results indicate that p27^BBP/eIF6 is present throughout oogenesis, partly associated with 60S subunits, partly free and with little cytoskeleton bound. During prophase I, p27^BBP/eIF6 is detected as a single band of 27-kDa. Upon maturation induced by progesterone or protein kinase C, a serine-phosphorylated 29 kDa isoform appears and is kept throughout development to the neurula stage. Confocal microscopy showed that the distribution of p27^BBP/eIF6 and its association with the cytoskeleton varies according to oogenesis stages. Briefly, in stage 6 oocytes, p27^BBP/eIF6 has a limited dot-like distribution, and does not co-localize with cytokeratin, whereas upon maturation it spreads throughout the cytoplasm. After fertilization, a large fraction coalesces around cytomembranes and a cytochalasin B-sensitive co-localization with cytokeratin occurs. RNAse removes p27^BBP/eIF6 from the cytokeratin fibres. Developmental data suggest a role of p27^BBP/eIF6 in controlling ribosomal availability or regulating cross-talk between ribosomes and the cytoskeleton.Received 7 April 2005; received after revision 11 May 2005; accepted 25 May 2005R. Carotenuto and N. De Marco contributed equally to the paper     

发酵液中1,6—二磷酸果糖含量的测定

采用分级分离的方法除弃一切有干扰的物质,被测物１,６二磷酸果糖在浓盐酸溶液中加热,分解成的呋喃化合物与间苯二酚显色,且在５７０ｎｍ处有一最大吸收峰。根据此原理,探索出了快速准确测定１,６二磷酸果糖的方法,平均回收率在９８．５％以上。     

新试剂2,4-二溴-6-硝基苯基重氮氨基-4-苯基-2-噻唑的合成及与钯(Ⅱ)显色反应的研究

本文研究了新显色剂2,4-二溴-6-硝基苯基重氮氨基-4-苯基-2-噻唑（DB-o-NDAT）的合成及与把（II）的显色反应．在阳离子表面活性剂N-氯代十六烷基吡啶（CPC）存在下,于pH=6.0～8.0的KH2PO4-NaOH缓冲溶液中,把（II）与该试剂形成1：1的紫色配合物,其最大吸收峰位于600nm,摩尔吸光系数为5．3×104L·mol－1·Cm－1．钯（II）浓度在0～16μg／25ml范围内符合比尔定律,该试剂对钯的选择性良好,用于Pd-C催化剂及矿样中微量把（II）的测定,结果令人满意．     

Changes in body temperature and circulating levels of interleukin-6 after intra-arterial injections or infusions of tumor necrosis factor α in guinea pigs

Tumor necrosis factor (TNF) is released systematically during the early phase of endotoxin induced fever. To study the effects of this cytokine in guinea pigs, 2 g TNF were intra-arterially injected as a bolus or slowly infused within 60 min. Both modes of administration induced a biphasic elevation of the animals' abdominal temperature lasting 6 h and stimulated the release of endogenous interleukin-6 (IL-6)-like activity. The second phase of the thermal response and the release of endogenous IL-6-like activity were significantly higher, when TNF was slowly infused into the animals' circulation, in spite of a transiently higher TNF-like activity after the bolus injection of TNF. Both TNF and IL-6 may therefore be regarded as candidates to trigger the febrile response in guinea pigs.     

黑色素瘤模型的建立与评价

为了快速有效地进行在体药物筛选,研究了以小鼠黑色素实体瘤组织中的原代细胞构建黑色素瘤模型的方法。从荷黑色素瘤小鼠的组织中提取原代肿瘤细胞,与体外培养的B16细胞通过皮下注射分别植入两组C57BL/6小鼠体内,考察两组小鼠肿瘤显现时间和生长速度。结果表明：当接种浓度为5.0×10⁶个/ mL、每只0.2 mL时,小鼠黑色素瘤原代细胞和体外培养的B16细胞成瘤率分别为100%和80%,且小鼠右前肢肿瘤(大小约4 mm³）出现时间分别约在第3天和第8天。紫杉醇对两种模型的初步评价显示,与体外培养的B16细胞模型相比,原代B16细胞模型是体内筛选和评价特定化合物抗肿瘤活性的一种可行而有效的方法,成瘤时间较短、成瘤率高,所得实验数据误差也较小。模型的建立为相关药物评价模型的开发研究提供了一条可借鉴的新途径。     

光还原法制备Ag/Bi2WO6可见光催化剂及其性能研究

利用离子液体辅助醇热法制备了具有较高活性的Bi_2WO_6可见光催化剂,并进一步采用光还原法将Ag纳米粒子负载到Bi_2WO_6催化剂表面.利用Ag良好的导电性以及表面plasma效应,有效增强了催化剂的可见光吸收,降低了光生载流子复合的几率,显著提高了污染物降解的光催化活性.同时确定了最佳Ag含量和反应条件.     

电阻型超导限流器和10kV配电网继电保护相配合的仿真分析

短路电流的增大已经成为高电压等级电网建设和运行中的一个突出问题.超导限流器是目前最为理想的限流装置,而其与现有继电保护装置的配合是超导限流器挂网运行的关键技术之一.利用PSCAD/EMTDC仿真软件搭建了电阻型超导限流器和继电保护装置的自定义模型,在此基础上分析了引入电阻型超导限流器对10kV配电网电流保护的影响,并对两者的配合问题进行了仿真研究,进一步提出通过改变超导体参数来调整电阻型SFCL的限流电阻和限流水平,以实现与继电保护协调配合,为超导限流器应用于实际电网参数配置提出了重要的量化依据.     

10kV线路供电能力评估体系的研究及其应用

配网供电能力评估的重点在于对10kV线路的科学评价和分级管理．介绍了10kV线路供电能力分级评估体系和评价方法，通过实例分析该评估体系的应用情况，提出通过对配电网10kV线路进行定期评估，确定配网建设、改造的目标和具体对象，持续提高配网运行管理水平．     

Drug susceptibility of PCA in WBB6F1-W/Wv mice

Our previous study revealed that passive cutaneous anaphylaxis (PCA) can be produced in congenitally mast cell-deficient WBB6F1-W/W^v (abbreviated as W/W^v) mice on sensitization with undiluted or slightly diluted allogeneic and xenogeneic antisera but not on sensitization with allogeneic monoclonal immunoglobulin (Ig)E and IgG1 antibodies regardless of the antibody concentration [1]. In view of these findings, the present study was conducted to characterize PCA in this strain from its drug susceptibilities using mast cell-bearing WBB6F1-+/+ (abbreviated as +/+) and B6D2F1 mice as references. PCA in W/W^v mice mediated by a low dilution (1  4) of hyperimmune serum to bovine serum albumin of the B6D2F1 mouse origin was markedly suppressed by CV-6209, an antagonist of platelet-activating factor (PAF), but not by antihistamines such as cyproheptadine and oxatomide. In contrast, PCA in +/+ and B6D2F1 mice mediated by a high dilution (1  128) of the anti-serum (virtually by IgG1 antibody) was nearly completely suppressed by antihistamines but not by CV-6209. A remarkable difference between PCA in W/W^v and reference mice was also observed in the susceptibility to monoclonal anti mouse granulocyte (Gr-1) antibody PCA in W/W^v mice was potently suppressed by the 1- to 3-day pretreatment with this antibody but that in references was not at all. Putting these present results together with the previous finding that anti-granulocyte antibody greatly reduces circulatory Gr-1⁺ leukocytes, 1 to 3 days after the treatment [2], it is highly probable that PCA in W/W^v mice mediated by some antibody isotypes other than IgE and IgG1 is produced by PAF mainly released from Gr-1⁺ cells, while IgG1 antibody-mediated PCA in mast cell-bearing reference mice is evoked by histamine derived from mast cells. PCA homologous to that in W/W^v mice could also be produced in the reference mice on sensitization with undiluted or slightly diluted antiserum, when generalized blueing due to excess IgG1 antibody was removed by the oxatomide treatment be fore the antigen challenge. Received 10 December 1997; received after revision 2 February 1998; accepted 23 February 1998