西施舌血清和肌肉提取液凝集性能研究

利用血凝试验测定西施舌(Coelomactra antiquata)血清和肌肉提取液对8种红细胞的凝集活性,同时进行热稳定性、糖抑制和pH影响试验.结果表明,西施舌的血清和肌肉提取液均能凝集试验所用的8种红细胞,但肌肉提取液的凝集效价高于血清(人O型血除外).二者的热稳定性均较高.血清对草鱼红细胞的凝集作用可被试验用的7种糖抑制,而肌肉提取液则不被7种糖抑制.二者在pH 4.0-10.0的范围内均具有凝集活性.试验结果表明,西施舌血清和肌肉提取液均含有凝集素,但种类不同.     

从甘薯品种中筛选凝集素

在相同种植环境,相同提取条件下,对6种甘薯抗感品种的叶片组织进行凝集素的提取,研究结果表明：6个品种均存在着凝集素,其区别在于品种之间对兔红细胞的凝集活性及活性峰不同,检没了这些凝集素的中性糖含量,热稳定性,酸碱稳定性,糖抑制作用和抑菌作用,为进一步纯化提供了一些科学依据。     

金属离子和变性剂对黄精凝集素Ⅱ构象与功能的影响

黄精凝集素II（Polygonatum cyrtonema Hua.Lectin II,PCLII)具有323nm的荧光发射峰和281．6nm的激发峰,其远紫外圆二色谱（CD谱）显示224nm负峰,分子中含有17．3％的α螺旋和45．8％的β折叠,在10mmol/L的SDS中,PCL II完全丧失兔红细胞凝集能力及促T－淋巴细胞有丝分裂活性,CD谱呈现双负峰的a螺旋构象,去除SDS后,则呈无规卷曲构象,此时,荧光发射峰红移而激发峰蓝移,PCL II仍完全失活,在EDTANa2溶液中,PCL II凝集红细胞能力及促淋巴细胞有丝分裂活性完全丧失,去除EDTA后,红细胞凝集活性完全恢复,但仍失去促淋巴细胞有丝分裂能力,PCL II二级结构变化不大,荧光光谱的变化表明微环境受到影响。     

棉花凝集素对枯萎病菌的抑制作用与其受体的研究

研究了ＦＩＴＣ或ＨＲＰ标记的棉花凝集与枯萎病菌丝体作用后，在荧光显微镜下或扫描电镜下可以清晰地看到ＦＩＴＣ－凝集素或ＨＲＰ－凝集素－受体复合物在菌丝体上的均匀分布实验表明，纯化的棉花凝集素对棉花枯萎病菌丝体的生长有较强的抑制作用，当凝集素浓度达１５０μｇ／ｍＬ时，可以使枯萎病菌丝体的生长完全停止。     

Influence of ethanol on calcium,inositol phospholipids and intracellular signalling mechanisms

Summary Studies have implicated Ca⁺⁺ in the actions of ethanol at many biochemical levels. Calcium as a major intracellular messenger in the central nervous system is involved in many processes, including protein phosphorylation enzyme activation and secretion of hormones and neurotransmitters. The control of intracellular calcium, therefore, represents a major step by which neuronal cells regulate their activities. The present review focuses on three primary areas which influence intracellular calcium levels; voltage-dependent Ca⁺⁺ channels, receptor-mediated inositol phospholipid hydrolysis, and Ca⁺⁺/Mg⁺⁺-ATPase, the high affinity membrane Ca⁺⁺ pump.Current research suggests that a subtype of the voltage-dependent Ca⁺⁺ channel, the dihydropyridine-sensitive Ca⁺⁺ channel, is uniquely sensitive to acute and chronic ethanol treatment. Acute exposure inhibits, while chronic ethanol exposure increases⁴⁵Ca⁺⁺-influx and [³H]dihydropyridine receptor binding sites. In addition, acute and chronic exposure to ethanol inhibits, then increases Ca⁺⁺/Mg⁺⁺-ATPase activity in neuronal membranes. Changes in Ca⁺⁺ channel and Ca⁺⁺/Mg⁺⁺-ATPase activity following chronic ethanol may occur as an adaptation process to increase Ca⁺⁺ availability for intracellular processes. Since receptor-dependent inositol phospholipid hydrolysis is enhanced after chronic ethanol treatment, subsequent activation of protein kinase-C may also be involved in the adaptation process and may indicate increased coupling for receptor-dependent changes in Ca⁺⁺/Mg⁺⁺-ATPase activity.The increased sensitivity of three Ca⁺⁺-dependent processes suggest that adaptation to chronic ethanol exposure may involve coupling of one or more of these processes to receptor-mediated events.     

A novel interplay between membrane and nuclear melatonin receptors in human lymphocytes: significance in IL-2 production

Human lymphocyte melatonin, through membrane and nuclear receptors binding, acts as an activator in IL-2 production. Antagonism of membrane melatonin receptors using luzindole exacerbates the drop of the IL-2 production induced by PGE₂ in peripheral blood mononuclear and Jurkat cells. This paper studies the melatonin membrane and nuclear receptors interplay in PGE₂-diminished IL-2 production. The decrease in IL-2 production after PGE₂ and/or luzindole administration correlated with downregulation in the nuclear receptor RORα. We also highlighted a role of cAMP in the pathway, because forskolin mimicked the effects of luzindole and/or PGE₂ in the RORα expression. Finally, a significant RORα downregulation was observed in T cells permanently transfected with inducible MT₁ antisense. In conclusion, we show a novel connection between melatonin membrane receptor signalling and RORα expression, opening a new way to understand melatonin regulation in lymphocyte physiology. Received 23 September 2008; received after revision 19 November 2008; accepted 21 November 2008     

隐层神经元自适应算法：通过数据表示达到完备学习

提出采用数据表示，即通过一能把输入空间变换到高维空间的接受函数，把所有训练样本变换到集合空间中，然后将经过重新表示的数据馈入神经网络，则不需再采用其他算法，神经网络可达到完备学习。还给出了对正弦函数近似问题应用数据表示与隐层神经元自适应算法结合达到完备学习的实例。     

菜豆植物凝集素对小鼠骨髓细胞微核发生率的影响

目的分析不同品种菜豆植物凝集素对小鼠骨髓细胞微核发生率的影响,明确其生物安全性。方法小鼠腹腔注射3个品种菜豆凝集素,6 d后取小鼠骨髓细胞,吉姆萨染色,光学显微镜下观察小鼠骨髓细胞的微核发生情况并进行微核发生率的统计,进而判断不同种类菜豆植物凝集素是否具有致突变作用。结果实验组3个品种的菜豆植物凝集素引起的小鼠微核发生率与阴性对照组比较差异均无统计学意义,而阳性对照组与实验组及阴性对照组间差异有统计学意义(P<0.05);小鼠骨髓细胞微核发生率与菜豆植物凝集素呈剂量—反应关系,但与小鼠性别无关。结论 3个含量分别为高、中、低水平的菜豆植物凝集素对小鼠骨髓细胞均无致突变作用,可进一步用于有关药物和生物制剂的开发应用。     

不同转移潜能人肝癌细胞系中GP73糖基化修饰水平比较

 利用抗体亲和层析纯化不同转移潜能人肝癌细胞系中的高尔基体蛋白73（GP73）,比较不同转移潜能人肝癌细胞系中GP73 糖基化修饰水平,为GP73 成为肝癌标志物提供依据。纯化的GP73 通过质谱鉴定后,分别进行蛋白印迹（western blot）和凝集素印迹（lectin blot）分析,比较其在不同转移潜能肝癌细胞系的糖基化修饰水平。实验发现,GP73 含有伴刀豆凝集素（ConA）、橙黄网胞盘菌凝集素（AAL）、小扁豆凝集素（LCA）和红腰果E 型凝集素（PHA-E）识别的糖型,且单位GP73 的LCA、PHA-E 识别的岩藻糖和平分型糖型含量在肝癌细胞Huh7、MHCC97L、MHCC97H、HCCLM3 中有升高趋势。研究表明,单位GP73 岩藻糖和平分型聚糖结构随肝癌细胞的转移潜能升高而增多。     

猪甘露聚糖结合凝集素A血清含量的测定

应用自行制备的抗体,采用双抗体夹心法对仔猪血清中MBL-A的浓度进行检测.结果显示,杜洛克仔猪血清中MBL-A的浓度基本呈正态分布,其平均值为9.1 ng/mL.长白猪仔猪MBL-A的浓度呈现3种特征性正态分布状态,平均值分别为5.40,7.45和9.12 ng/mL.表明不同品种的猪血清MBL-A水平存在差异,将为抗病育种工作提供基础研究依据.