DNA的动力学特性及其空间组态

在生物体中存在着大量的非线性现象.本文从B型DNA的双螺旋结构出发,建立起B-DNA的碱基对运动方程,求解了在DNA的开放系统中所激发的孤子运动,由此较为详细地分析了DNA的动力学特性及其空间组态.     

几种多种离子对DNA的效应

对金定鸭肝脏ＤＮＡ的紫外光谱分析表明：ＺＮ＾２＋可与碱基的－Ｎ经予体较弱地络合，在ＤＮＡ两链间提供一个桥，有利于ＤＮＡ复性，Ｆｅ＾３＋能与ＤＮＡ中的磷酸酯氧结合，稳定络合物，以致会阻碍ＤＮＡ复性。Ａｌ＾３与ＤＮＡ中的磷酸酯氧亲和力高，容易形成更稳定的络合物，使ＤＮＡ双链紧密结合而对热非常稳定。     

口腔医源性感染控制的方法

为了深入研究控制口腔医源性感染的方法和措施，对口腔临床感染的原因、流行状况、传播方式与途径进行了探讨，得出一些有效控制口腔医源性感染的方法和建议：建立完整的病人档案，提高医务人员的免疫力与运用物理屏障技术相结合，做好个人防护和器械、设备的消毒等。     

表达HCV核心蛋白的重组减毒鼠伤寒沙门菌口服免疫小鼠的研究

构建了丙型肝炎病毒(HCV)核心蛋白原核表达质粒pQE-HCV,转化到减毒鼠伤寒沙门菌SL7207中,SDS-PAGE和Western blot检测到该重组菌能表达3种分子量的HCV核心蛋白.以该重组菌作为口服型活疫苗灌胃接种BALB/c小鼠,检测到小鼠产生的抗HCV核心蛋白IgG及迟发型超敏反应、T细胞增殖反应和细胞毒性T淋巴细胞反应.结果表明该重组菌能有效诱导免疫应答,尤其能高效诱导细胞免疫应答,这为研制高效免疫、成本低廉、接种方便的HCV疫苗提供了一个新的可行途径.     

6种瓢虫的RAPD分析及在分类上应用的研究

利用随机引物分别对6种瓢虫的DNA进行了聚合酶链式反应（RAPD－PCR）的实验。结果显示，用相同引物扩增不同种瓢虫的基因组DNA，扩增产物多态性DNA片段的数目是不同的；两种不同引物的扩增产物中，各自呈现出种、属的特异性片段，其可用于种、属的鉴别；聚类图显示了种、属之间亲缘关系的远近程度，并与形态学分类结果相一致。实验分析还发现：七星瓢虫不同个体间多态性DNA特有带较多，遗传较稳定；龟纹瓢虫与之相比，不同个体间多态性DNA的特有带较少，变异程度较大。     

在大肠杆菌中利用反义RNA抑制乙肝病毒（HBV）X基因的表达

将乙肝病毒（ＨＢＶ）ａｙｗ株完整的Ｘ基因正向重组到原核表达质粒ｐＢＶ－２２１的ＰＬ启动子下游，得到能表达Ｘ蛋白的重组质粒ｐＢＶ－ＨＢＶ（＋）；同时将Ｘ基因反向重组到原核表达质粒ｐＢＶ－２２０的ＰＬ启动子下游，得到能转录Ｘ基因反义ＲＮＡ的重组质粒ｐＢＶ－ＨＢＸ（－）。利用这两个质粒，构建出能同时转录Ｘ基因ｍＲＮＡ和反义ＲＮＡ的重组质粒ｐＥＸ。ＡＮ－ＨＢＸ，并在原核水平上，证实了反义ＲＮＡ对Ｘ基因的表     

人HBV前S1蛋白在大肠杆菌中的融合型表达

乙型肝炎病毒(HBV)的包膜蛋白依次由108—115氨基酸的前S1蛋白、55氨基酸的前S2蛋白和226氨基酸的S蛋白组成。前S1蛋白的N端既含有直接介导毒粒与肝细胞膜结合的位点,又含有许多免疫原性较强的T细胞与B细胞表位,抗前S1抗体水平还是HBV血清学检查的一项重要指标。     

乙型肝炎病毒感染与原发性肝癌关系的临床分析

分析了福建省的莆田、厦门两市１８２例原发性肝癌（ＰＨＣ）病案的临床特点，探讨与ＨＢＶ感染、ＨＢ之间关系，以及观察其中部分病例。采集其血清作ＨＢＶ标志物检测，ＰＨＣ患者１２９例ＨＢｓＡｇ阳性７７例，阳性率５９．６９％（Ｒ－ＰＨＡ），比当地自然人群调经４．２９％高出１２．９１倍，６１例ＰＨＣ血清作ＨＢＶ标志物检查（ＥＩＡ），有９１．８０％病例感染ＨＢＶ，比配对对照组感染率８．２０％高出１０．２０倍（Ｐ     

Analysis of components of conserved “backbone sequences”among genomes of Shigella spp. strains

Difference in the genomic compositions of prokaryotes is the basis of the diversity in their biological characters. However, besides their flora-or strain-specific genes,those floras with closer relationship in the evolution also have conserved “backbone sequences”, which reveal the marks of their origin and evolution, and these “backbone sequences”are just the basis of their elementary living abilities and common biological properties. Shigella is very closely related to E. coli in the origin and evolution, and may turn out to belong to the same genus. In this study, a microarray containing E. coli K-12 whole genome and Sf301 specific ORFs is used to investigate the genomic components of four Shigella strains. The results indicate that 16%-22% K-12 ORFs sequences are not detected in the genome of Shigella strains while the genome of Shigella contains at least 2800 conserved ORFs, which compose the common “backbone sequences”.Advanced analysis indicated that the “backbone sequences”are the essential components in maintaining the normal physiological activities of intestinal bacteria. Furthermore,only 20% Sf301-specific ORFs exist in other strains simultaneously, which demonstrate the great genome heterogeneity and the genetic diversity among the strains.     

Phylogenetic position of Schnabelia, a genus endemic to China： Evidence from sequences of cpDNA matK gene and nrDNA ITS regions

The chloroplast gene matK and the internal transcribed spacers (ITS) of the nuclear ribosomal DNA from Schnabelia, a genus endemic to China, and 6 genera of Verbenaceae and 13 genera of Lamiaceae were sequenced. The phylogenetic signal and validity outgroups were measured and evaluated by means of the relatively apparent synapomorphy analysis (RASA). Independent and combined phylogenetic analyses for the matK and ITS sequences were performed using the maximum parsimony (MP), neighbor-joining (NJ) and maximum likelihood (ML) methods, indicating that Schnabelia oligophylla and Caryopteris terniflora form a sister-group relationship. The Caryopteris complex is not shown to be a monophyly because Trichostema, C. paniculata and C. forrestii are paraphyletic to the clade containing the remaining members of the complex. A monophyly of Ajugoideae proposed by Cantino et al., including 8 genera in this study, is strongly supported and the closest relatives of Schnabelia are in the Ajugoideae (Lamiaceae), especially near Caryopteris terniflora. The polygenetic analyses also showed that the genera of Lamiaceae and Verbenaceae sampled in this tudy are phylogenetically mixed and the genus Avicennia is distant to other genera of Verbenaceae. RASA and combined analysis can be used as effective approaches to determining the relationships among phylogenetically complex groups.