DBP对斜生栅藻及天然混合藻类致毒效应研究

作为塑料和橡胶等化工产品的增塑剂,邻苯二甲酸酯类化合物的生产量和使用量在我国和世界上均呈上升趋势,其在环境中的广泛存在及其所产生的行为效应已引起人们的高度重视。       

小鼠脑微血管内皮细胞与隐球菌作用前后基因表达谱分析

目的 比较小鼠脑微血管内皮细胞系bEnd.3细胞与隐球菌作用前后基因表达谱的变化,为隐球菌的嗜中枢性研究提供新的线索.方法 采用基因芯片法比较bEnd.3细胞与不同血清型隐球菌作用前后基因表达谱的变化,并进一步通过荧光定量PCR的方法对某些重要基因的变化加以验证.结果 我们对bEnd.3与隐球菌作用前后基因表达进行了对比,共获得差异基因383条,其中263条基因表达下降,120条基因表达上升,并根据比较结果选取了黏附分子CDH 10及硒转运蛋白SELENBP 1两个基因进行荧光定量PCR验证,结果与芯片结果一致.发现bEnd.3与隐球菌作用后CDH 10表达明显下降,而SELENBP1表达明显上升.结论 隐球菌能引起脑血管内皮细胞黏附分子CDH 10表达下降及硒结合蛋白selenbp1表达上升,这可能与其侵袭血脑屏障有关.而SELENBP1的表达上升可能与神经系统症状有关.     

Role of IKK/NF-κB signaling in extinction of conditioned place aversion memory in rats

The inhibitor κB protein kinase/nuclear factor κB (IKK/NF-κB) signaling pathway is critical for synaptic plasticity. However, the role of IKK/NF-κB in drug withdrawal-associated conditioned place aversion (CPA) memory is unknown. Here, we showed that inhibition of IKK/NF-κB by sulphasalazine (SSZ; 10 mM, i.c.v.) selectively blocked the extinction but not acquisition or expression of morphine-induced CPA in rats. The blockade of CPA extinction induced by SSZ was abolished by sodium butyrate, an inhibitor of histone deacetylase. Thus, the IKK/NF-κB signaling pathway might play a critical role in the extinction of morphine-induced CPA in rats and might be a potential pharmacotherapy target for opiate addiction.     

人类口腔菌的一个新属

牙周病是人类的一种常见病、多发病,其致病菌具有多样性和复杂性,有关该病的致病菌和病因学的研究,对防治工作具有重要意义。作者从牙周病患者的病灶处分离到了一株细菌（90-1）,并对其进行了鉴定,现将结果报告如下。     

武汉东湖颗粒悬浮物的结构与元素组成

本研究于1989-1990对武汉东湖营养水平不同的二个湖区的颗粒悬浮物的干物质结构和元素组成进行了分析。综合平均值表明,浮游动物的现存量约为浮游植物的1/4,浮游动物群落以小型的原生动物和轮虫占优势。从年平均值来看,浮游生物的干重占颗粒悬浮物干物质的2.5-7.6%,浮游生物碳量占颗粒悬浮物碳量的4.0-9.8%;颗粒悬浮物的碳/氮比与一般浮游植物的比值相似,但明显大于多数浮游动物;颗粒悬浮物的碳与干物重之比约为一般浮游生物的3/4;颗粒悬浮物的灰分含量约为45%,显着高于除硅藻以外的其它浮游生物。从数量上来看,有机碎屑是东湖生态系统颗粒悬浮物最重要的组成部分,而活体浮游生物只占颗粒悬浮物很小的一部分(<10%);这意味着在东湖来自以浮游植物为核心的食物网的有机碎屑的形成速率显着大于有机碎屑的矿化速率。       

嗜盐隐杆藻胞外多糖的分离、纯化及理化特性

嗜盐隐杆藻（Ａｐｈａｎｏｔｈｅｃｅ ｈａｔｏｐｈｙｔｉｃａ）培养液经离心,浓缩、透析、有机溶剂沉淀得胞外多糖（Ｅｘｏｐｏｌｙｓａｃｃｈａｒｉｄｅｓ,ＥＰＳ）粗品,经ＤＥＡＥ－纤维素二次柱层析纯化得ＥＰＳ精品。葡聚糖Ｇ－２００凝胶过滤表明其为单一组份。对其进行理化测试并对各组分进行定量分析,多糖、已糖醛酸、硫酸根含量分别为４０．９６％２３．２７％和３４．４６％,元素分析你测得Ｃ、Ｈ、Ｎ、Ｓ含量分别为     

化学修饰--提高酶催化性能的重要工具

讨论了化学修饰对酶的稳定性、有机溶剂溶解性、特殊条件下的活性和选择性的影响。对常见的和近期出现的酶修饰技术,包括交联酶晶体、酶蛋白侧链功能基共价修饰、酶蛋白表面修饰、结合定点突变的化学修饰、通过酶活性位点氨基酸原子置换进行化学突变等方法作了重点阐述。     

Response of osteoblasts to low fluid shear stress is time dependent

The process of mechanotransduction of bone, the conversion of a mechanical stimulus into a biochemical response, is known to occur in osteoblasts in response to fluid shear stress. In order to understand the reaction of osteoblasts to various times of flow perfusion, osteoblasts were seeded on three-dimensional scaffolds, and cultured in the following conditions: continuous flow perfusion, intermittent flow perfusion, and static condition. We collected samples on day 4, 8 and 12 for analysis. Osteoblast proliferation was demonstrated by cell proliferation and scanning electron microscopy assay. Additionally, the expression of known markers of differentiation, including alkaline phosphatase and osteocalcin, were tested by qRT-PCR and alkaline phosphatase activity assay, and the deposition of calcium was used as an indicator of mineralization demonstrated by calcium content assay. The results supported that low fluid shear stress plays an important role in the activation of osteoblasts: enhance cell proliferation, increase calcium deposition, and promote the expression of osteoblastic markers. Furthermore, the continuous flow perfusion is a more favorable environment for the initiation of osteoblast activity compared with intermittent flow perfusion. Therefore, the force and time of fluid shear stress are important parameters for osteoblast activation.     

植物KCO基因密码子使用特性

以植物钾离子外排通道（K’channeloutward．rectifier,KCO）基因为研究对象,运用CodonW软件分析了75个植物KCO基因密码子的使用模式,探讨密码子的使用模式和影响密码子使用的各种可能因素。结果表明：碱基组成差异（r=0．961,P〈0．01）和自然选择（r=0．568,P〈0．01）是影响密码子使用的主要因素,并且高表达的基因强烈偏爱使用以G或C结尾的密码子。确定了UUC、CUC等26个均以G／C结尾的密码子为植物KcD基因的高表达优越密码子。