Optic nerve injury demonstrated by MRI with STIR sequences

We studied nine patients with optic nerve injury associated with closed head trauma by magnetic resonance imaging (MRI) with short inversion time inversion recovery (STIR) sequences on 11 occasions from 4 days to 14 years after the injury: three studies were within 17 days and eight over 4 months to 14 years. MRI revealed abnormal high signal in 10 of the 11 injured nerves. MRI 4 days after the injury showed no abnormality.     

SEN病毒D亚型ORF1-C端基因的克隆、表达和鉴定

目的:获得SENV-D亚型ORF1-C端蛋白基因序列,并进行表达,为进一步研究及诊断、治疗应用奠定基础.方法:用PCR法从SENV阳性血清中获得SENV-DORF1C端基因,测序验证后,构建了pQE30-SENV-D重组表达质粒,并经过转化E.coli M15,IPTG诱导表达,Western blot分析表达结果.结果:获得了正确序列的SENV-D亚型ORF1-C端蛋白基因序列,表达出Mr约为38×103的蛋白.表达蛋白能与患者血清中相应的抗体结合,发生抗原抗体反应.结论:成功获得并表达了SENV-D-ORF1-C端蛋白,并经Western blot印迹法证实能与阳性血清中的抗体发生抗原抗体反应,有可能用于检测SENV-D抗体.为今后进一步研究有助于疫情监测及早期发现感染者的抗体奠定了坚实的基础.     

Post-translational processing of thyrotropin-releasing hormone precursor in rat brain: identification of 3 novel peptides derived from pro TRH

The sequence of rat hypothalamic pro-thyrotropin releasing hormone, deduced by sequencing of cDNA, in addition to 5 TRH progenitor genitor sequences contains leader, trailer and 4 intervening sequences separated by paired basic amino acid sequences. We have developed radioimmunoassays to synthetic peptides corresponding to portions of these cryptic proTRH sequences and have used these assays to identify and partially characterize proTRH peptides, distinct from TRH, in extracts of rat brain. Two of these peptides correspond closely in size to one intervening sequence and the car☐y-terminal sequence of proTRH. Three other peptides correspond to the intact amino-terminal leader sequence and two peptides formed by a further cleavage of the leader sequence at an internal paired basic amino acid sequence.     

SLE小鼠高IgG血症Fcgr2b基因序列分析

目的: 测定系统性红斑狼疮(SLE)小鼠模型-NZB/WF1双亲NZB,NZW小鼠 Fcgr2b基因启动子区核酸序列,明确Fcgr2b基因启动子区的突变性质.方法:扩增NZB,NZW小鼠Fcgr2b基因启动子DNA进行核酸序列分析.采用ELISA法测定、比较(NZB×NZW )F1×NZW回交小鼠Fcgr2b基因B/W型与W/W型组间血清总IgG 水平.结果:NZB小鼠Fcgr2b基因启动子区与正常鼠Balb/C相比存在2个部位碱基缺失,分别为13 bp及3 bp.NZW小鼠除有3个碱基置换外,与Balb/C鼠该基因启动子区序列相同.回交小鼠Fcgr2b基因B/W型组血清总 IgG水平明显高于W/W型组(P<0.0001).结论:NZB小鼠Fcgr2b基因启动子区存在碱基缺失,且该缺失突变可能与血清总IgG水平升高有关.     

单次激发半傅立叶FSE序列MRCP的应用

目的评价单次激发半傅立叶FSE序列MRCP图像质量及诊断价值，分析胆道梗阻性疾病的MRCP影像学表现。方法218例病人行单次激发半傅立叶FSE序列MRCP扫描，然后对图像进行质量评价，根据ERCP及手术结果对照分析胆道梗阻性疾病的MRCP的影像学征象和特点，讨论单次激发半傅立叶FSE序列MRCP在胆道梗阻性疾病中的诊断价值。结果单次激发半傅立叶FSE序列MRCP扫描时间为5～7S，优良图像为82．5％，合格图像为10，6％，差为6．9％。单次激发半傅立叶FSE序列MRCP在胆道梗阻性疾病中，对各类梗阻疾病的定位诊断率为100％，梗阻端形态，胆胰管之间的关系均可显示。病因定性诊断率为95．5%。结论单次激发半傅立叶FSE序列MRCP不受呼吸运动影响，图像优质率高，扫描速度快，可显示各种疾病的胆胰管梗阻改变，对诊断较小的结石及泥沙样结石有较大的价值，诊断较早期胆管癌准确率高，可满足临床诊断的要求。     

粘病毒抵抗基因-1启动子88位点G/T多态性影响乙型肝炎病毒感染的自然转归

目的探讨乙型肝炎病毒（HBV）自限感染和慢性感染与粘病毒抵抗基因-1（MxA）启动子的-88位点G／T单核苷酸多态性的关系。方法收集100例抗-HBs和抗-HBc阳性的HBV自限感染者和340例慢性感染者的外周全血，提出基因组DNA；采用竞争分化聚合酶链反应技术为基础的方法进行MxA-88G／T基因分型；采用单因素Odds ratio和x^2检验等方法进行统计学分析。结果MxA-88G／G基因型（低表达型）检出率为50．2％（221／440），T／T基因型（高表达型）检出率为5．5％（24／440），G／T杂合型检出率为44．3％（195／440）。与慢性感染患者相比，自限感染患者携带较低的G／G基因型（41．0％与52．9%，P〈0．05）、G等位基因（62．5％与75．3％，P〈0．01）和较高的T／T基因型（16．0％与2．4%，P〈0．01）、T等位基因（37．5％与24．7％，P〈0．01），而两者之间的G／T杂合型差异无统计学意义。结论MxA-88G／T基因型能在一定程度上影响HBV感染的自然转归，有望成为临床上HBV感染转归的预测指标。     

The universal algorithm of maturation for secretory and excretory protein precursors.

During maturation, most proteins undergo different posttranslational modifications. In most simple cases, signal peptidases remove the signal or leader peptide from the precursors of the secretory proteins during their translocation across the ER membrane. For biologically active proteins, such as enzymes, regulatory and defense proteins, toxins, etc., additional maturation-regulating mechanisms were shown to proceed with limited proteolysis of inactive precursors by specific enzymes. A number of specific enzymes from different cell types selectively cleave proproteins at specific processing sites. In this work, we analyzed the sequences of protein precursors synthesized in the excretory glands of different animals and identified new, non-traditional processing sites. They differ from the motifs previously identified in secreted proteins' precursors and enabled us to reconstruct the sequence of events leading to the conversion of protein precursors into the final products (mature proteins). We also found that in animals, the maturation mechanism of secretory and excretory proteins and the set of enzymes involved are species specific. The processing sites identified in protein precursors in this study are useful for a more detailed genome analysis and more accurate mature protein sequence prediction.     

SNP及其在畜牧业中的应用前景

SNP(single nucleotide polymorphisns-单核苷酸多态性)是继限制性片段长度多态性和微卫星之后，新发展起来的第3代分子标记。已成为一类新的遗传标记，广泛应用于基因定位、克隆和遗传多样性研究。本文介绍了SNP的特性、检测方法及其在畜牧业研究生产中的广泛利用前景。并提出了SNP研究中遇到的一些问题。