非综合征母系遗传耳聋的分子遗传学研究

对一个母系遗传的“线粒体耳聋”家系,应用ＰＣＲ,ＰＣＲ－ＳＳＣＰ,ＰＣＲ－ＲＦＬＰ,ＰＣＲ产物克隆测序技术对该家系ｍｔＤＮＡ进行了分析,发现该家系全部患者都有ｍｔＤＮＡ１２ＳｒＲＮＡ基因１５５５位点Ａ１５５５Ｇ突变,另外,除此突变位点外,我们还在部分患者中发现了一新的突变位点：ｍｔＤＮＡ１２ＳｒＲＮＡ基因１４３８位点Ａ→Ｇ改变,说明Ａ１５５５Ｇ突变可能是导致该家系耳聋的主要因素之一．     

超越椭圆曲面到有限修改曲面的解析映射之投影族

设Ｒ和Ｓ为两个超越椭圆黎曼曲面。Ｓ表示Ｓ的有限修改曲面。文中主要讨论了Ｒ到Ｓ和Ｒ到Ｓ的解析映射之投影和投影间的关系可能发生的各种情形。可作为对过去只在最大Ｐｉｃａｒｄ常数下之研究的重要补充。     

Fuzzy拓扑中的S—RO等价

首先引入两个Ｆ拓扑空间Ｓ－ＲＯ等价的概念，并给出其刻画条件，此外，还得到了两个Ｆ拓扑空间是ＲＯ－等价的充要条件，最后，讨论了那些性质是Ｓ－ＲＯ等价性质。     

ANLL中转录因子GATA—2基因点突变

了解转录因子ＧＡＴＡ－２基因在ＡＮＬＬ中的表达和突变情况,方法：采用ＲＴ－ＰＣＲ检测８５例ＡＮＬＬ病人外周血单个核细胞中ＧＡＴＡ－２基因的表达情况,ＰＣＲ产物进一步经单链构象多态性（ＳＳＣＰ）分析以了解基因突变情况。结果：绝大多数ＡＮＬＬ都表达了ＧＡＴＡ－２基因（８９．４％）,ＳＳＣＰ分析发现一例Ｍ２型的ＰＣＲ产物出现异常迁移带,核苷序列分析显示在ＧＡＴＡ－２基因第８９２位的核苷酸出现点突变,即第     

ICR／RMU—nu无胸腺裸鼠的培育

作者从一窝白色ＩＣＲ远交系小鼠群中发现突变裸鼠，采用回交一互交号法“ｎｕ”基因保留下来，随后用隔离器养的ＩＣＲ小鼠为代乳鼠，通过剖腹取胎净化该种群，微生物学检查其主要项目达到ＳＰＦ级标准，术后动物饲养于洁净层流架中，＾６０Ｃｏ灭菌饲料，酸化水、鼠盒、垫料均高压灭菌，以纯合雄鼠与杂合雌鼠１：１非近亲繁殖，扩大了种群，定名ＩＣＲ／ＰＭＵ－ｎｕ裸鼠。与此同时，对突变裸鼠进行了免疫生物学检查，剖检１０余只     

肝细胞性肝癌P53基因多态性定点突变

对Ｐ５３阳性的８例肝细胞性肝癌（ＨＣＣ）广西科学，１９９５，２（１）：５５～５７）中的７例的Ｐ５３基因进行ＤＮＡ单键构象多态性分析（ＳＳＣＰ）和ＰＣＲ扩增物直接测序。结果，７例均在Ｐ５３第７外显子第２４９编码区的３号位发现异常。１例在２４９编码区的第３碱基微小丧失引起乱码突变；另６例在此位点同时出现突变的Ｔ和Ｃ带，成为的多态性突变形式。外显子５、６、８和９没有异常。估计除黄曲霉毒素Ｂ１外可能有别的致癌因素协同作用造成此种多态性。认为南宁地区是继中国江苏启东和莫桑比克后的第３个ＨＣＣＰ５３基因２４９编码区有集中突变热点的地区。     

广义变换图G^＋∞（R,S）的边连通度

记Ａ＋∞（Ｒ,Ｓ）为具有行和向量Ｒ及列和向量Ｓ的所有ｍ×ｎ阶非负整数矩阵的集合．广义变换图Ｇ＋∞（Ｒ,Ｓ）的顶点定义为Ａ＋∞（Ｒ,Ｓ）中的矩阵,两个顶点（矩阵）相邻当且仅当它们可通过一次变换相互得到．并证明Ｇ＋∞（Ｒ,Ｓ）的边连通度等于其顶点的最小度δ（Ｇ＋∞（Ｒ,Ｓ））．     

关于右RIC环

本文的主要目的是讨论Ｓｍｉｔｈ提出的两个公开问题,这两个问题是：（１）右ＰＣＩ 否为右ＳＩ环？（２）右ＲＩＣ环→右ＣＥＰＩ环和右ＣＥＰＩ环→右ＳＩ环是否成立？本文对上述上公开问题给出了肯定的回答,并且证明了：（１）设Ｒ是右ＲＩＣ环,若Ｍ１是ＣＳ模,Ｍ２是半单模,则Ｍ１＋Ｍ２是ＣＳ模;（２）设Ｒ昌左Ｎｏｅｔｈｅｒ在ＲＩＣ环,则每个有限生成右Ｒ－模满足限制极小条件。     

常压烧结Si3N4陶瓷的阻力（R—曲线）特性

文章利用压痕微裂纹法测试了３种Ｓｉ３Ｎ４基陶瓷的Ｒ曲线．结果发现：添加Ｙ２Ｏ３和Ａｌ２Ｏ３的Ｓｉ３Ｎ４材料（１号）具有明显上升的Ｒ曲线；添加ＺｒＯ２的材料（２号）次之；添加ＡｌＮ的材料（３号）的Ｒ曲线变化幅度最小．并结合断口形貌分析发现，材料的Ｒ曲线行为与其微观结构密切相关．     

鸡肝脏和心脏线粒体的热化学研究

利用ＬＫＢ２２７７生物活性检测系统，测定了家鸡两个品种的心脏和肝脏线粒体的活性及其代谢热。结果表明：这两个品种鸡的心脏和肝脏线粒体热谱图各异，ＡＶＩＡＮ心脏和肝脏线粒体的总体谢时间和总代谢热量大于ＳＴＡＲ－ＣＲＯＳＳ２８８。讨论了热谱图与不同品种鸡的线粒体代谢的关系。     

Detection of a new mutation (1467-A) for the pedigree with mucopolysaccharidosis type Ⅱ from a Chinese family

Mucopolysaccharidosis type Ⅱ is of high genetic heterogeneity. PCR-DNA sequencing was used to study the mutation hot spots in the IDS gene of a Chinese MPS Ⅱ pedigree. A new mutation （1467-A） not yet reported worldwide was detected. This mutation located at 448th codon in the coding region of exon 9 deletes one “A” at the end of 1467 bp （cDNA）. The frame-shift mutation makes the peptide chain shorten from amino acids 550 to 459, probably altering the configuration of IDS enzyme protein remarkably and lowering the activation of IDS greatly. Therefore it is supposed to be the direct cause of the patient with MPS Ⅱ and to be a necessary premise for prenatal gene diagnosis.     

A cluster of cystic fibrosis mutations in the first nucleotide-binding fold of the cystic fibrosis conductance regulator protein.

The gene responsible for cystic fibrosis (CF) has recently been identified and is predicted to encode a protein of 1,480 amino acids called the CF transmembrane conductance regulator (CFTR). Several functional regions are thought to exist in the CFTR protein, including two areas for ATP-binding, termed nucleotide-binding folds (NBFs), a regulatory (R) region that has many possible sites for phosphorylation by protein kinases A and C, and two hydrophobic regions that probably interact with cell membranes. The most common CF gene mutation leads to omission of phenylalanine residue 508 in the putative first NBF, indicating that this region is functionally important. To determine whether other mutations occur in the NBFs of CFTR, we determined the nucleotide sequences of exons 9, 10, 11 and 12 (encoding the first NBF) and exons 20, 21 and 22 (encoding most of the second NBF) from 20 Caucasian and 18 American-black CF patients. One cluster of four mutations was discovered in a 30-base-pair region of exon 11. Three of these mutations cause amino-acid substitutions at residues that are highly conserved among the CFTR protein, the multiple-drug-resistance proteins and ATP-binding membrane-associated transport proteins. The fourth mutation creates a premature termination signal. These mutations reveal a functionally important region in the CFTR protein and provide further evidence that CFTR is a member of the family of ATP-dependent transport proteins.     

A frame-shift mutation in the cystic fibrosis gene.

Cystic fibrosis (CF) is a common recessive lethal genetic disorder, affecting 1 in 1,600 Caucasians. The disease causes defective regulation of chloride-ion transport in exocrine cells. Although in all CF families the disease is linked to a locus on chromosome 7q31, there is clinical heterogeneity in the severity of the disease and the age at which it is diagnosed. CF is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. A three-nucleotide deletion (delta F508) causing the loss of a phenylalanine residue in the tenth exon of the CFTR gene has been found on 70% of CF chromosomes. We have now characterized a CF family in which neither parent of the affected individual carries the common mutation, and identified a two-nucleotide insertion in the CF allele of the mother. The mutation introduces a termination codon in exon 13 of the CFTR gene at residue 821, and is predicted to result in the production of a severely truncated nonfunctional protein.     

甲型流感病毒PB1-PA蛋白作用位点的发现与分析

 基于共进化理论,探究了甲型流感病毒PB1蛋白与PA蛋白上具有共同进化可能性的保守九聚片段 (C9MP)。结构信息显示PB1蛋白的第1-15位氨基酸与PA蛋白的第239-716位氨基酸具有相互作用域;对该区域变异分布的分析发现,PA蛋白第670位氨基酸Q所在的C9MP与PB1蛋白的第9位氨基酸F、第12位氨基酸V和第13位氨基酸P所在的C9MP在PB1-MP1相互作用面上具有最低的共进化值。结合DSSP程序的分析表明,由PA蛋白第670位氨基酸Q与PB1蛋白的第9位氨基酸F、第12位氨基酸V与第13位氨基酸P构成的区域可能成为潜在的相互作用位点。     

大豆胰蛋白酶抑制剂SBTi—A2新类型Ti^d突变位点的初步研究

纯化的大豆胰蛋白酶抑制下Ｔｉ＾ａ和Ｔｉ＾ｄ分别经烷基化，ＣＮＢｒ裂解，痛ＰＡＧＥ电泳，Ｔｒｉｃｉｎｅ／ＳＤＳ－ＰＡＧＥ电泳分析，初步证明了Ｔｉ＾ｄ的突变位点发生在蛋白Ｎ端１－８４氨基酸残基上。     

天人菊matK基因克隆及生物信息学分析

为了完善天人菊的遗传信息,丰富菊科植物分子生物学分析数据.通过PCR扩增、基因克隆获得天人菊matK基因的完整核苷酸序列,采用生物信息学方法分析天人菊matK蛋白的结构及性质,并与其他12种matK氨基酸序列进行对比,构建系统进化树.结果表明,天人菊matK基因全长1296 bp,可编码432个氨基酸,二级结构以α-螺...     

柱前衍生化-HPLC测定马氏珠母贝肉中氨基酸的含量

以邻苯二甲醛-9-芴甲基氯甲酸酯为衍生化试剂,对氨基酸进行柱前衍生,建立了35℃下,醋酸钠缓冲液、甲醇及乙腈为流动相,用Eclipse AAA氨基酸分析柱和二极管阵列检测器的氨基酸色谱分析方法,18种氨基酸在36 min内获得了较好的分离,在一定浓度范围内,氨基酸的峰面积与浓度的线性相关系数在0.990 6～0.999 8之间,相对标准偏差为1.96%～5.45%(n=5).并测定了马氏珠母贝肉蛋白中氨基酸的组成和含量.结果表明,马氏珠母贝肉蛋白中含有至少18种氨基酸,其中8种必须氨基酸总含量达39%以上,是一种优质的功能食品原料.     

Structures of the cloned chitinase and its truncant from A.caviae

Aeromonas caviae can secrete several chintinases with different molecular weights. One chitinase gene chi 1 has been cloned and sequenced. It encodes a protein of 865 amino acids with a signal peptide at the N-terminus, a polycystic kidney disease(PKD)-like domain, a triosephosphate isomerase(TIM) catalytic region, a receptor for egg jelly(REJ)-like domain and two tandem chitin binding domains (ChBDs). The entire chitinase degrades colloid chitin both endolytically and exolytically into N-acetylglucosamine, chitobiose and chitotriose. When removing the 302 amino acids at C-teminus its activity remains but the degraded products are chitobiose, chitotriose and chitotetraose. The study shows that for the full-length chitinase, its substrate with the shortest length is chitotriose while in its truncated form, it is chitotetraose.     

计算变异学创立背景及其用途

为了克服生物信息学和计算生物学中字母或数字不受序列长度、氨基酸组成和位置、相邻氨基酸影响的缺陷,根据自然界普遍存在的随机性原理,创立计算变异学。计算变异学用氨基酸对可预测性、氨基酸分布概率和变异概率3种方法量化整个蛋白质及每个氨基酸,用活的、动态的测量指标量化分析蛋白质。计算变异学方法可以应用于研究蛋白质进化、遗传病定量诊断,分析蛋白质结构与功能、药物设计和病毒变异预测等领域。