Moxostoma的磷酸葡萄糖异构酶电泳研究

用水平淀粉凝胶电泳对290尾Moxostoma属3个种的胭脂鱼进行了磷酸葡萄糖异构酶(PGI)的研究,得到10种电泳表现型(Phenotype),由A与B两个位点控制。A位点向阳极迁移,有a、b、c、d及e5个等位基因;B位点向阴极迁移,有f及g两个等位基因。种间差异明显。 不同采集地区(德克萨斯、佛罗里达及路易斯安那)的鱼类,新鲜材料、冰冻材料及雌雄之间电泳结果无差异。     

N49 phospholipase A2, a unique subgroup of snake venom group II phospholipase A2

A novel phospholipase A₂ (PLA₂) with Asn at its site 49 was purified from the snake venom of Protobothrops mucrosquamatus by using SP-Sephadex C25, Superdex 75, Heparin-Sepharose (FF) and HPLC reverse-phage C₁₈ chromatography and designated as TM-N49. It showed a molecular mass of 13.875 kDa on MALDI-TOF. TM-N49 does not possess enzymatic, hemolytic and hemorrhagic activities. It fails to induce platelet aggregation by itself, and does not inhibit the platelet aggregation induced by ADP. However, it exhibits potent myotoxic activity causing inflammatory cell infiltration, severe myoedema, myonecrosis and myolysis in the gastrocnemius muscles of BALB/c mice. Phylogenetic analysis found that that TM-N49 combined with two phospholipase A₂s from Trimeresurus stejnegeri, TsR6 and CTs-R6 cluster into one group. Structural and functional analysis indicated that these phospholipase A₂s are distinct from the other subgroups (D49 PLA₂, S49 PLA₂ and K49 PLA₂) and represent a unique subgroup of snake venom group II PLA₂, named N49 PLA₂ subgroup.     

Nitric Oxide Mediates Root K+/Na+ Balance in a Mangrove Plant,Kandelia obovata,by Enhancing the Expression of AKT1-Type K+ Channel and Na+/H+ Antiporter under High Salinity

It is well known that nitric oxide (NO) enhances salt tolerance of glycophytes. However, the effect of NO on modulating ionic balance in halophytes is not very clear. This study focuses on the role of NO in mediating K⁺/Na⁺ balance in a mangrove species, Kandelia obovata Sheue, Liu and Yong. We first analyzed the effects of sodium nitroprusside (SNP), an NO donor, on ion content and ion flux in the roots of K. obovata under high salinity. The results showed that 100 μM SNP significantly increased K⁺ content and Na⁺ efflux, but decreased Na⁺ content and K⁺ efflux. These effects of NO were reversed by specific NO synthesis inhibitor and scavenger, which confirmed the role of NO in retaining K⁺ and reducing Na⁺ in K. obovata roots. Using western-blot analysis, we found that NO increased the protein expression of plasma membrane (PM) H⁺-ATPase and vacuolar Na⁺/H⁺ antiporter, which were crucial proteins for ionic balance. To further clarify the molecular mechanism of NO-modulated K⁺/Na⁺ balance, partial cDNA fragments of inward-rectifying K⁺ channel, PM Na⁺/H⁺ antiporter, PM H⁺-ATPase, vacuolar Na⁺/H⁺ antiporter and vacuolar H⁺-ATPase subunit c were isolated. Results of quantitative real-time PCR showed that NO increased the relative expression levels of these genes, while this increase was blocked by NO synthesis inhibitors and scavenger. Above results indicate that NO greatly contribute to K⁺/Na⁺ balance in high salinity-treated K. obovata roots, by activating AKT1-type K⁺ channel and Na⁺/H⁺ antiporter, which are the critical components in K⁺/Na⁺ transport system.     

Leucine-rich repeat C4 protein is involved in nervous tissue development and neurite outgrowth, and induction of glioma cell differentiation

LRRC4, leucine-rich repeat C4 protein, has been identified in human （GenBank accession No. AF196976）, mouse （GenBank accession No. DQ177325）, rat （GenBank accession No. DQ119102） and bovine （GenBank accession No. DQ 164537） with identical domains. In terms of their similarity, the genes encoding LRRC4 in these four mammalian species are orthogs and therefore correspond to the same gene entity. Based on previous research, and using in situ hybridization, we found that LRRC4 had the strongest expression in hippocampal CA1 and CA2, the granule cells of the dentate gyrus region, the mediodoral thalamic nucleus, and cerebella Purkinje cell layers. Using a P19 cell model, we also found that LRRC4 participates in the differentiation of neuron and glia cells. In addition, extracellular proteins containing both an LRR cassette and immunoglobulin domains have been shown to participate in axon guidance. Our data from neurite outgrowth assays indicated that LRRC4 promoted neurite extension of hippocampal neurons, and induced differentiation of glioblastoma U251 cells into astrocyte-like cells, confirmed by morphology observation and glial fibrillary acidic protein expression.     

不同食物饲养幼鼠对肝组织化学影响的观察

实验采用刚断乳的幼鼠２０ 只, 分为两组喂养, 每组１０ 只, 对照组和普通饲料喂养（简称Ａ 组）,另一组用奶粉喂养（简称Ｂ组）。分别喂养２０天后, 对其肝组织化学进行了分组定性对比观察。结果显示：Ａ 组肝细胞糖原ＰＡＳ反应, ＳＤＨ、ＣｈＥ活性高于Ｂ组, 分别为强阳性（）, 而Ｂ组ＬＤＨ, ＡＫＰ活性比Ａ组强, 分别为强阳性及最强阳性 （, ）。     

聚-ε-赖氨酸高产菌株的筛选及其发酵工艺的初步研究

利用亚甲基蓝平板初筛、摇瓶复筛,从土壤中筛选了一株聚-ε-赖氨酸(ε-PL)高产菌株,ε-PL摇瓶产量大于2g/L,经初步鉴定该菌株为白色链霉菌(Streptomyces albulus)。对该菌株发酵生产ε-PL的培养基成分进行初步研究表明:葡萄糖是最好的碳源,酵母粉和硫酸铵是最佳的复合氮源,在优化培养基下,ε-PL摇瓶产量达到3.9g/L。     

正常菌群对常见致病菌拮抗作用的研究

生物拮抗作用是微生物种群关系研究的一个侧面,实验中我们使用从皮肤上分离的常住菌——痤疮丙酸杆菌(A14-1)和表皮葡萄球菌(F65)对常见致病菌如金黄色葡萄球菌(C189)、绿脓杆菌(C8514)和埃希氏大肠杆菌(C1356)的体外拮抗试验表明,它们具有明显的拮抗作用,拮抗作用一般从48小时开始,72小时明显。而皮肤常住菌间无拮抗作用,相反它们还有协同作用,这对于皮肤的自净以及维持皮肤的微生态平衡具有重要的作用。此外,实验中还进行了乳杆菌和双歧杆菌等正常菌群分离株与上述常见致病菌的体外拮抗试验,结果表明也     

海州香薷Actin基因片段克隆及表达分析

通过克隆海州香薷Actin基因片段并分析其组织表达,为研究海州香薷重金属抗性相关基因的表达调控奠定基础。根据Gen Bank中其他植物Actin基因保守序列设计兼并引物,以海州香薷根总RNA为模板,利用RT-PCR技术分离得到Actin基因片段。序列分析结果表明,海州香薷Actin基因片段长576 bp,编码192个氨基酸,与其他植物同源基因的氨基酸序列相似性为84%-97%,所克隆的序列为Actin基因的同源片段,将其命名为Eh ACT,在Gen Bank中提交序列,获得登录号AGT37260。半定量RT-PCR分析结果表明,Eh ACT在海州香薷的根、茎和叶中表达相对稳定,初步表明其可作为研究海州香薷基因表达的内参基因。     

原发不育症子宫内膜花生凝集素受体的研究

本文以PNA(花生凝集素)为探针,应用ABC亲和组化技术,对69例原发不育症患者的子宫内膜PNA受体进行了检测.结果表明,原发不育症子宫内膜的增生期、分泌期PNA受体的阳性率均显著低于年龄相似、有生育史的对照组子宫内膜的阳性率.不育症子宫内膜分泌欠佳的PNA受体阳性率显著低于不育症分泌期不同时期子宫内膜的阳性率.提示,这种差异可能与雌孕激素对两组子宫内膜作用水平的不同引起.