多发性家族性毛发上皮瘤的临床和遗传特征分析

目的了解国人多发性家族性毛发上皮瘤(MFT)的临床表现和遗传特点。方法对收集的3个MFT家系和1989年以来国内报道的16个MFT家系进行系统的临床和遗传学的总结分析。结果⑴典型表现为沿鼻唇沟对称分布多个坚实透明的结节;⑵MFT呈常染色体显性遗传;⑶女性好发,男女性外显率之比约为0.7∶1;⑷患者发病年龄从出生到58岁不等,平均发病年龄为16.5岁;⑸可与其它遗传性皮肤病如雀斑、进行性对称性红斑角化症等并发;⑹已从国内MFT家系中发现6种新的CYLD基因突变,CYLD基因突变越靠近羧基端,患者的发病年龄越大,皮损数量越多、越大,分布越广泛。结论MFT为常染色体显性遗传病,在国人中并非罕见,女性好发,男女患病率之比为0.7∶1,患者平均发病年龄为16.5岁,典型皮损为沿鼻唇沟对称分布、皮肤颜色、粟粒至蚕豆大、坚实透明的多个结节,可与雀斑、进行性对称性红斑角化症等遗传性皮肤病并发,目前已经发现6种CYLD基因新的突变可导致MFT,CYLD基因突变越靠近羧基端,患者的发病年龄越大,皮损数量越多、越大、分布越广泛。     

角膜炎鱼鳞病耳聋综合征的GJB2基因突变的研究

目的对国内首例先天性角膜炎.鱼鳞病.耳聋综合征(KID)的GJB2基因和GJB6基因突变检测。方法提取KID综合征患者及家族成员的基因组DNA,采用聚合酶反应扩增GJB2基因和GJB6基因所有的外显子及其邻近的剪切点并进行双向直接测序。结果KID综合征患者的GJB6基因未见变化,GJB2基因核苷酸序列第148位碱基由G突变成A,位于GJB2基因的外显子2中,GJB2基因编码的连接蛋白第50位的天冬氨酸转换成天冬酰胺(D50N)突变。结论GJB2基因突变是导致汉族人发生角膜炎.鱼鳞病.耳聋综合征的致病基因。     

鸡CAPN1基因多态性及其与肉质性状的关联分析

采用聚合酶链式反应-单链构象多态(PCR-SSCP)方法对147只寿光鸡CAPN1基因第4外显子进行多态性检测,分析其与部分肉质性状的关系。在CAPN1基因第4外显子上共检测到3种基因型AA、AB和BB,它们的基因型频率分别为0.286、0.510和0.204。方差分析结果表明：在寿光鸡群体中,BB基因型个体的胸肌pHu值显著高于AA基因型个体(P＜0.05);AA基因型个体的肌内脂肪含量显著高于BB基因型个体(P＜0.05)。     

世界第5个先天性眼组织缺损致病基因被发现

经过近10年对一个先天性眼组织缺损家系的研究及116例散发病例的调查，由相关视光专家教授领衔的课题组，日前发现了世界第5个导致先天性眼组织缺损的新基因——ABCB6，该研究相关论文发表在最新一期《美国人类遗传学》杂志上。     

科技动态

美发现叶酸吸收缺陷综合症成因美国布朗克斯·爱因斯坦医学院癌症中心I.David Goldman研究小组对肠内叶酸吸收机制及遗传性的叶酸吸收缺陷综合症疾病的研究成果发表在最近出版的《细胞》杂志上。他们确定了一种名为PCFT/HCP1的基因对于叶酸吸收的重要作用,并证明了这种基因发生的功能缺失突变会导致叶酸吸收缺陷综     

有问必答

高血压是否会遗传,与普通高衄压是否存在区别,以及饮食注意点？ 高血压与遗传有关,目前多数学者认为,高血压属于多基因遗传性疾病。通过高血压患者家系调查发现,父母均患有高血压者,其子女今后患高血压概率高达45％;父母一方患高压病者,子女患高血压的几率是28％;而双亲血压正常者其子女患高血压的概率仅为3％。     

烟草细胞质雄性不育相关基因nad7的生物信息学分析

编码线粒体呼吸链复合物Ⅰ亚基的had7基因最后两个外显子缺失,会导致烟草表现为细胞质雄性不育(CMS).采用生物信息学方法,分析了不育型和野生型烟草中nad7基因在其编码蛋白各结构层次上存在的差异.结果表明,nad7基因最后两个外显子缺失可导致其编码蛋白缺失泛醌氧化还原酶(NADH)的结构域,极可能成为影响线粒体呼吸链复合物I完整性的关键因素,从而可能成为导致烟草CMS的根本原因之一.     

xanK单位点突变对野油菜黄单胞菌菌黄素合成及黄原胶产物性质的影响

菌黄素的存在使得野油菜黄单胞菌产生的黄原胶发酵液呈现黄色,并显著影响了黄原胶的性状、产量及提取工艺。研究过程中得到一株自然突变的不产生菌黄素的黄原胶生产菌株XW,测序发现该菌株xanK基因的一处碱基突变使相应编码的天冬氨酸突变为甘氨酸。为探究xanK基因突变对菌黄素合成的影响,通过回补试验将野生型菌株的xanK基因导入到突变菌株中,发现突变菌株的菌黄素合成恢复,说明该突变导致菌黄素合成受阻。此外,对两种黄原胶产物进行分析,结果显示突变菌株产生的黄原胶在黏度和丙酮酸含量上均高于野生型菌株,而分子量和乙酰基含量要低于野生型菌株,说明菌黄素对黄原胶的合成可能具有复杂的影响。     

产紫红色素菌株的筛选及诱变

以土壤和3种水果为样品,马铃薯-抗生素培养基为基质,采用稀释平板法分离产紫红色素的菌株,并以产紫红色素菌株为出发菌株进行紫外诱变.结果表明:从苹果表面上获得1株产紫红色素的真菌,通过个体形态和菌落特征初步分析为镰孢茵属菌株(fusarium sp.),该菌以马铃薯-蔗糖(35%)为基质发酵,获得胞内紫红色素OD值为0.790,胞外色素OD值为0.538,该突变菌株获得其胞内紫红色素OD值为0.895,胞外色素OD值为0.503,且该突变菌株产生色素的速度要快于出发菌株1 d.     

一株放线菌产棕色素初探及其16S rDNA序列分析

对分离自酒厂土壤中的一株放线菌产水溶性棕色素的路径进行简要分析,得出结论为:在进行液态发酵时添加0.075%酪氨酸,色素产生效果最佳.色素的紫外-可见光谱测定表明,该色素可能为黄酮类物质.基于该菌16S rDNA序列分析,该菌与金色链霉菌相似度最高,并与一些色素产生菌有较近的亲缘关系.     

Analytical methods for the determination of acrylamide in food products: a review

In early 2002, the Swedish National Food Administration reported high acrylamide levels in heat-treated carbohydrate-rich foods. Consequently, intensive activity began examining the many different types of food, and thousands of analyses have been undertaken world wide. Measurement data have been published in many different types of media. Within this flood of publications, there are only a limited number of articles concerned with the technical aspects of the measurements. This review focuses on the state-of-the-art in the analysis of acrylamide in foodstuffs. It covers information on methods from peer-reviewed articles and other sources (e.g. a survey carried out among official and private laboratories of the Member States of the European Union). Alternative methods are presented and discussed alongside the more common measurement techniques for acrylamide in foodstuffs. Special attention is given to sample preparation. The greatest differences between the analytical methods was for acrylamide extraction and clean-up. The influence of different extraction techniques or extraction solvents/solvent mixtures on the measurement results has not yet been fully investigated. There is also a lack of understanding about the sample clean-up. Since both might have a large impact on the results of the analysis, this review should also be considered as a basis for further investigations.     

Meat safety and quality: a biological approach

Safe, high-quality meat that is minimally processed, containing few added chemicals, is what is desired by the modern consumer. Biological approaches to meat safety appear more natural and, thus, are more readily acceptable. In this review, we examine biological approaches for meat safety and quality in the preharvest animal as well as during slaughter and in the post-harvest processing of the meat product. Biological components, including probiotics (Direct-Fed Microbials), vaccines, bacteriocins and lytic bacteriophage, are important components of a comprehensive approach to meat safety and quality.     

Semicarbazide in baby food: a European survey

The concentration of semicarbazide (SEM) in baby food packed in glass jars with lids sealed with plastic gaskets was determined in more than 100 samples, produced in 11 European countries, and purchased at local supermarkets in 14 countries. The method used for the analyses has been recently validated in a collaborative study. A correlation between the measured SEM concentration and the type of food (fruit, vegetables, meat and combinations of those) was found. The lowest values of SEM were found in samples containing only fruit with a mean concentration of 5.5±3.8 μg/kg. Some brands were characterised by low levels of SEM regardless of the composition. The levels of SEM found were comparable for the different countries of production. Both, high and low semicarbazide levels were found among organic and conventional samples.