Epstein─Barr病毒膜抗原在中国仓鼠卵巢（CHO）细胞中的表达

将切去３’端穿膜序列的ＥＢ病毒膜抗原（ＭＡ）基因,插入ｐＳＶ２－ｄｈｆｒ质粒的ＳＶ４０早期启动子下游,构建了真核表达载体ｐＳＶ２－ｄｈｆｒＧＰＴＲ,使两个ＳＶ４０早期启动子分别调控ＭＡ和二氢叶酸还原酶（ｄｈｆｒ）基因。将该重组质粒转化ＣＨＯ－ｄｈｆｒ细胞,在选择培养基中筛选阳性克隆,用氨甲喋呤加压扩增,建立了表达ＥＢＶ－ＭＡ的克隆细胞系。ｗｅｓｔｅｒｎｂｌｏｔ分析证明,所表达的蛋白的分子量大约为３４０ｋｄ和２２０ｋｄ。经过细Ｓｅｐｈａｒｏｓｅ２Ｂ琼脂糖凝胶层析初步纯化的抗原与福氏佐剂混合免疫小鼠,２周后小鼠血清中出现明显的ｇｐ３４０／２２０特异性抗体,表明切去嵌膜区结构的ＥＢＶ－ＭＡ基因在ＣＨＯ细胞中的表达产物具有同天然膜抗原相似的分子量大小、糖基化程度、免疫特异性和免疫原性,可望成为ＥＢ病毒人用基因工程亚单位疫苗。     

寡糖素对红花及三七培养细胞的生理作用

三种寡糖素,即来自人参（Ｐａｎａｘ ｇｉｎｓｅｎｇ）培养细胞的人参寡糖素、红花（Ｃａｒｔｈａｍｕｓ ｔｉｎｃｔｏｒｉｕｓ）培养细胞的红花寡糖素、黑节草（Ｄｅｎｄｒｏｂｉｕｍ ｃａｎｄｉｄｕｍ）植物的黑节草寡糖素对红花及三七（Ｐａｎａｘ ｎｏｔｏｇｉｎｓｅｎｇ）的培养细胞的生长及代谢产物的含量均有显著的促进作用。寡糖素可耐高温高压（１２１℃、．ｂｓ／ｃｍ＾２）灭菌１５分钟而不失活,其对植物培养细胞的     

江苏野菜资源的利用与开发

江苏野菜资源丰富,共计１９２种,隶属４４科１０８属,其中蕨类植物７科１５属５１种,种子植物３７科９３属１４１种。江苏野菜利用历史悠久,近年已发展成为规模种植,产生良好的经济效益和社会效益。     

酪氨酸羟化酶基因载体－pCMVTH 质粒的构建及在大鼠骨骼肌内的表达

为用转基因方法治疗巴金森氏病大鼠模型,本研究采用分子克隆技术,将合成多巴胺的关键酶－酪氨酸羟化酶（ＴＨ）的基因,克隆进入以巨细胞病毒ＣＭＶ为启动子的载体质粒内,经限制性内切酶定位分析证实该重组的ＤＮＡ质粒的可靠性。携带ＴＨ基因的ＰＣＭＶＴＨ质粒以ＬＩＰＯ－ＦＥＣＴＩＮ介导,在培养的原代骨骼肌细胞中高效表达。本研究为进一步用转基因的细胞植入脑内以治疗巴金森氏病打下一定基础。     

少年人群接种乙肝疫苗后七年随访观察

对７９名ＨＢＶ标志阴性少年人群,以乙肝疫苗１０μｇ×３的免疫剂量和０、１、２月的免疫程序进行接种,对其抗－ＨＢｓ免疫应答和临床保护效果作了为期７年的定人随访。结果表明,抗－ＨＢｓ阳转率在免后三个月时为１００％,均值为３０８４ＭＩＵ／ｍｌ。至免后８４个月时疫苗接受者中仍有５５．７％的抗－ＨＢｓ水平≥１０ＭＩＵ／ｍｌ。６例检出抗－ＨＢｓ,其中５例的抗－ＨＢｓ持续处于高水平。全部观察对象无一例检出ＨＢｓＡｇ或发生临床肝炎。少年接种乙肝血源疫苗至少７年内可具有保护性抗体。故在此期内不需加强免疫。     

南瓜果肉色素的提取及稳定性的研究

本文研究了从南瓜果肉中提取色素的方法,并对它的光、热、酸、碱稳定性进行了研究,发现其性质较稳定,且原料来源广泛,提取工艺简单,着色效果好,是食品、医药、化妆品等领域的理想添加剂。     

野生紫斑牡丹和四川牡丹种子萌发特性及与其致濒的关系

野生牡丹种子一般较小,而且不同产地之间形状、大小差异较大。其萌发特性与栽培牡丹相比也有较大差异：萌发期长达半年以上,且萌发温度在１０～１５℃为宜,超过２０℃则明显不利于生根及上胚轴生长。四个不同分布地的四川牡丹种子萌发率较一致,均在６０～７７％之间。三个不同产地的紫斑牡丹种子萌发率则相差甚远,分布于甘肃文县的萌发率达７６％,而分布于陕西略阳和湖北神农架的萌发率则分别只有１２％和４．４％,出苗率则更低。本文认为紫斑牡丹的种子特性是其在自然界处于濒危状态的重要原因之一。     

Activation of MEK family kinases requires phosphorylation of two conserved Ser/Thr residues.

MEK is a family of dual specific protein kinases which activate the extracellular signal-regulated kinases by phosphorylation of threonine and tyrosine residues. MEK itself is activated via serine phosphorylation by upstream activator kinases, including c-raf, mos and MEK kinase. Here, we report the activation phosphorylation sites of human MEK1 and yeast STE7 kinase as determined by a combination of biochemical and genetic approaches. In human MEK1, substitution of either serine residue 218 or 222 with alanine completely abolished its activation by epidermal growth factor-stimulated Swiss 3T3 cell lysates or immunoprecipitated c-raf, suggesting that both serine residues are required for MEK1 activation. Phosphopeptide analysis demonstrated that serine residues 218 and 222 of human MEK1 are the primary sites for phosphorylation by c-raf. These two serine residues are highly conserved in all members of the MEK family, including the yeast STE7 gene product, a MEK homolog in the yeast mating pheromone response pathway. Mutation of the corresponding residues in STE7 completely abolished the biological functions of this gene. These data demonstrate that MEK is activated by phosphorylation of two adjacent serine/threonine residues and this activation mechanism is conserved in the MEK family kinases.     

Desulfurization of dibenzothiophene to 2-hydroxybiphenyl by some newly isolated bacterial strains

Gram-positive, non-spore-forming, non-acid-fast, rod-shaped aerobic bacteria with the ability to desulfurize dibenzothiophene (DBT) or dibenzosulfone (DBTO₂) were isolated from soil samples contaminated with fossil fuels. Using a bioavailability method, cells with the desired DbtS⁺ phenotype were enriched. Modified fluorescence and colorimetric assays were used for the initial detection of 2-hydroxybiphenyl (OH-BP) in microtiter plates; subsequently, isolates were grown in wells of microtiter plates and screened for the production of desulfurization product. Fluorescence under UV light and the production of colored product in the phenol assay were used as presumptive indications of production of OH-BP. Confirmation of the presence of OH-BP was achieved with HPLC, UV-absorbance, and mass spectrometry. Nutrient utilization and fatty acid composition (as discerned with Biolog plates and gas chromatography, respectively) were used to identify presumptively the strains as Rhodococcus erythropolis; colony and cell morphology may not be consistent with the identification achieved by nutrient utilization and fatty acid composition. The desulfurization end product, OH-BP, can not be used as carbon source by the tested strain, N1-36.     

Simultaneous extraction of soil phytoavailable cadmium,copper, and lead by chelating resin membrane

Cadmium, copper, and lead were extracted from suspensions of contaminated soils using metal chelating exchange resin membranes. Nine soils with widely varying properties and Cd, Cu and Pb levels were tested. Soil suspensions made up with 4 g in 40 mL deionized water were equilibrated with 5 cm² Ca-saturated Chelex exchange resin membrane which was retained inside a polypropylene bag and shaken at 150 rpm for 24 hrs. Resin membrane extractable Cd, Cu and Pb of the soils were correlated with Cd, Cu, and Pb uptake by young wheat seedlings grown in these soils and compared with soil Cd, Cu, and Pb extracted by 0.1 M HCl, 0.01 M CaCl₂, and 0.005 M Diethylenetriamine pentaacetic acid (DTPA). The amounts of Cd, Cu and Pb extracted by the Ca-saturated Chelex membrane from all tested soils correlated well with those absorbed by young wheat seedlings. The Ca-saturated Chelex membrane extractable Cd, Cu and Pb of the soil had the strongest correlation with plant uptake Cd, Cu and Pb among the extraction methods we tested. It was demonstrated that the Ca-saturated Chelex membrane extraction is an appropriate method in simultaneously estimating Cd, Cu and Pb phytoavailability of soil and is applicable to a wide range of soils.