基因-环境交互作用研究方法:无对照病例研究

从目前的观点来看 ,可以认为很少有疾病是纯粹由遗传或者环境因素决定的 ,基因 环境交互作用在许多疾病 ,特别是常见的慢性疾病或者是所谓的“复杂性状疾病”(ｃｏｍｐｌｅｘ ｔｒａｉｔｄｉｓｅａｓｅｓ)的发病中 ,具有非常重要的意义[1 ] 。基因 环境交互作用可以理解为遗传因素对环境因素易感性的影响[2 ] 。对于基因 环境交互作用的深入研究 ,有助于了解人群易感性差异的原因 ,进而可以对环境与疾病、基因与疾病的关系有更深入的认识。目前许多对复杂性状疾病病因的遗传流行病学研究得到非常不一致的结论[3] ,没有考虑到基因 环境交…     

儿童智力研究进展

早在上世纪初，许多学就提出了有关制约智力发展因素的不同假说。影响智力发展的因素是复杂的、多方面的，智力发展是诸因素之间相互作用的结果，其中，主要是遗传和环境的有机结合。近年来，国内外学对儿童智力影响因素进行了大量研究，对智力，智力测量、智力结构，智力理论等也进行了深入研究，为人类认识自己、开发智力提供了理论基础。     

遗传流行病学研究中的几种设计

许多常见慢性疾病(如癌症、心血管疾病等)的病因都是极其复杂的,遗传因素和环境因素都可能和这些疾病有关。识别这些复杂的病因是流行病学和遗传学研究者共同的目标,两门学科的相互渗透形成了遗传流行病学。相对来说,遗传流行病学是一个比较新的研究领域,它将遗传学和流行病学的设计和方法结合起来,以探索遗传因素和环境因素对疾病的单独作用以及它们对疾病的联合作用。其主要任务是评价环境因素与疾病状态的关联;评价疾病的家庭聚集性;通过分离分析判断疾病的遗传模式;从而最终通过和遗传标记连锁定位出致病基因。     

老人吃菠菜可防视网膜病变

研究人员通过对70岁以上的老人进行研究后发现:经常走路可以防止智力衰退和老年痴呆。人们都知道,走路对保持心脏健康有好处。新的研究发现,走路对保持大脑的敏锐也有好处。以前的研究已经证实,通过阅读或字谜游戏等智力锻炼可以减少老年痴呆的发生。但是关于身体锻炼对大脑的作用,以前的研究存在许多不一致的结论。     

遗传和环境效应对儿童少年智力影响的双生子研究

目的通过对双生子儿童智力测量指标的遗传度研究,探讨遗传和环境效应对儿童少年智力的影响程度。方法采用韦氏儿童智力量表(WISC-CR)对233对6～15岁同性别双生子进行智力测评,以组内相关系数法计算各智力指标的遗传度。结果6～15岁儿童少年总智商遗传度为0.437,言语智商遗传度为0.315,操作智商遗传度为0.482。积木和译码测验得分的遗传度分别为0.514和0.454,受遗传效应影响高于常识和词汇测验。结论遗传对儿童少年智力水平有中等程度影响,遗传和环境效应在各具体能力上影响程度不同。良好环境刺激对促进个体智力各方面潜能发展都将具有重要意义。     

38对双生子的智力分析

为了探讨遗传与环境对智力的影响程度，我们对沈阳市皇姑区11所中小学8～16岁的38对双生子进行了智商测定及分析，结果表明：双生子的智商明显低于一般人群；异卵双生子间智力差别显著，同卵双生子间智力差别不显著，说明遗传对儿童智力发育是有影响的；在一起生长的同卵双生子及异卵双生子，其智商均密切相关，足以证明环境对儿童智力发育影响的肯定作用，智力的遗传度为20％左右，进一步验证了环境在儿童智力发育中的重要性。     

孕激素非基因作用的研究进展

孕激素与孕激素核受体结合,通过结合靶基因上的激素应答元件,调节靶基因表达,孕激素的这种作用被称为基因作用。但许多实验已证明,孕激素可不依赖孕激素核受体的转录活性产生快速调节作用,这些作用被称为孕激素的非基因作用。对于孕激素的非基因作用可以通过孕激素核受体与孕激素膜受体实现。对于孕激素非基因作用的研究对动物和人的许多生理变化有新的理解,并为激素依赖性恶性肿瘤的发生和药物治疗研究开辟了新的前景。     

孕激素非基因作用的研究进展

孕激素与孕激素核受体结合,通过结合靶基因上的激素应答元件,调节靶基因表达,孕激素的这种作用被称为基因作用。但许多实验已证明,孕激素可不依赖孕激素核受体的转录活性产生快速调节作用,这些作用被称为孕激素的非基因作用。对于孕激素的非基因作用可以通过孕激素核受体与孕激素膜受体实现。对于孕激素非基因作用的研究对动物和人的许多生理变化有新的理解,并为激素依赖性恶性肿瘤的发生和药物治疗研究开辟了新的前景。     

代谢综合征相关基因多态性研究进展

代谢综合征(metabolic syndrome,MS)是一组复杂的代谢紊乱疾病,近年其逐渐成为对居民健康影响较大的公共卫生问题。MS的发生是由遗传和环境因素共同作用导致的,其遗传异质性和表型异质性强,许多基因及其多态性都与MS或其组分的发生有关。有关MS及其组分相关基因多态性的研究主要集中在脂联素编码基因(ADIPOQ)、过氧化物酶体增殖物激活受体γ基因(PPARγ)、转录因子7类似物2基因(TCF7L2)、脂肪含量和肥胖相关基因(fat mass and obesity-associated gene,FTO)和载脂蛋白基因等。而目前针对女性的遗传研究尚未引起广泛关注,尚需进一步研究以寻找其致病的特异性基因,为改善女性健康提供帮助。综述近年MS相关的基因多态性的研究热点。     

脆性X综合征FMR1基因研究进展

脆性X综合征是常见的遗传性智力低下综合征,是X连锁不完全显性遗传病,其发病机理是脆性X智力低下1号基因5＇端非翻译区(CGG)n三核苷酸串联重复序列大量扩增和CpG岛异常甲基化,引起脆性X智力低下1号基因失活,导致脆性X智力低下1号蛋白的缺失引起智力低下.该文对脆性X智力低下1号蛋白生物学功能,脆性X智力低下1号基因异常的分子机制等方面国内外研究最新进展作以综述.     

上海市7岁以下残疾儿童的流行病学研究

目的掌握残疾儿童现状为制定优生规划提供依据。方法采用１９９６年《中国残疾人实用评定标准》进行诊断。结果视力、听力、智力、肢体、综合残疾１２４人,现残率９．６８‰,现残率以智力残疾为首,其次分别为综合残疾、听力残疾、肢体残疾、视力残疾,智力残疾男童明显多于女童,３岁以上儿童残疾明显高于３岁以下儿童,致残的主要危险因素除听力与曾用过耳毒药物有关外,其余残疾类别均有明显的遗传倾向。结论加强健康教育,开展遗传咨询、产前诊断,是预防残疾儿童发生,提高出生人口素质的关键。     

Current understanding of the genetic basis for physical activity

Although it is well known that physical activity prevents and ameliorates a large number of conditions and chronic diseases, it is also incontrovertible that physical inactivity is becoming more prevalent. This paradox has led some to suggest that genetic/biological factors influence activity levels as opposed to the classical notion that voluntary activity is solely regulated by environmental factors. There is a plethora of recent data showing that there is considerable genetic influence on activity levels in both humans and animals and emerging evidence suggesting potential genomic locations for those genetic factors. Several independent lines of evidence suggest that dopamine receptor 1 (Drd1) and nescient helix loop helix (Nhlh2) are excellent candidate genes for the regulation of physical activity, with several other potential candidate genes only partially supported. This foundation provides the basis for continuing work to identify additional candidate genes, to identify other genetic factors that are involved in the regulation of physical activity, and to investigate the mechanisms by which these genes and genetic factors regulate activity.     

Genetic Variation in Human Vitamin C Transporter Genes in Common Complex Diseases

Adequate plasma, cellular, and tissue vitamin C concentrations are required for maintaining optimal health through suppression of oxidative stress and optimizing functions of certain enzymes that require vitamin C as a cofactor. Polymorphisms in the vitamin C transporter genes, compromising genes encoding sodium-dependent ascorbate transport proteins, and also genes encoding facilitative transporters of dehydroascorbic acid, are associated with plasma and tissue cellular ascorbate status and hence cellular redox balance. This review summarizes our current knowledge of the links between variations in vitamin C transporter genes and common chronic diseases. We conclude that emerging genetic knowledge has a good likelihood of defining future personalized dietary recommendations and interventions; however, further validations through biological studies as well as controlled dietary trials are required to identify predictive and actionable genetic biomarkers. We further advocate the need to consider genetic variation of vitamin C transporters in future clinical and epidemiologic studies on common complex diseases.     

Genetics of osteoporosis

Osteoporosis is a common disease with a strong genetic component characterised by reduced bone mass and an increased risk of fragility fractures. Twin and family studies have shown that genetic factors contribute to osteoporosis by influencing bone mineral density (BMD), and other phenotypes that are associated with fracture risk, although the heritability of fracture itself is modest. Linkage studies have identified several quantitative trait loci that regulate BMD but most causal genes remain to be identified. In contrast, linkage studies in monogenic bone diseases have been successful in gene identification, and polymorphisms in many of these genes have been found to contribute to the regulation of bone mass in the normal population. Population-based studies have identified polymorphisms in several candidate genes that have been associated with bone mass or osteoporotic fracture, although individually these polymorphisms only account for a small amount of the genetic contribution to BMD regulation. Environmental factors such as diet and physical activity are also important determinants of BMD, and in some cases specific nutrients have been found to interact with genetic polymorphisms to regulate BMD. From a clinical standpoint, advances in knowledge about the genetic basis of osteoporosis are likely to be important in increasing the understanding of the pathophysiology of the disease; providing new genetic markers with which to assess fracture risk and in identifying genes and pathways that form molecular targets for the design of the next generation of drug treatments.     

Gene-Environment Interaction in Genome-Wide Association Studies

It is a commonly held belief that most complex diseases (e.g.,diabetes, asthma, cancer) are affected in part by interactionsbetween genes and environmental factors. However, investigatorsconducting genome-wide association studies typically test foronly the marginal effects of each genetic marker on disease.In this paper, the authors propose an efficient and easily implemented2-step analysis of genome-wide association study data aimedat identifying genes involved in a gene-environment interaction.The procedure complements screening for marginal genetic effectsand thus has the potential to uncover new genetic signals thathave not been identified previously. association; environment; genes; genetic markers; genetics; genome     

多囊卵巢综合征的分子遗传学研究进展

多囊卵巢综合征是生育期妇女最常见的内分泌紊乱性疾病之一,以高雄激素血症、月经失调及高胰岛素血症为主要临床特征.多囊卵巢综合征的主要内分泌紊乱为高雄激素与胰岛素抵抗,其发病机理尚不清楚.该文从分子遗传学角度综述了雄激素代谢相关基因、糖代谢相关基因及促性腺激素相关基因等异常与多囊卵巢综合征发病的关系.遗传学研究表明多种基因与该病的易感性有关,提示该病的复杂遗传学背景.因此,对多囊卵巢综合征的分子遗传学研究将有助于进一步揭示其发病机理.     

泛耐药鲍氏不动杆菌获得性耐药基因与可移动遗传元件检测结果的指标聚类分析

目的 了解泛耐药鲍氏不动杆菌(PDRAB)获得性耐药基因、可移动遗传元件的存在,分析二者的相关性.方法 收集医院ICU 2009年1月-2010年3月痰液标本检出的菌株,采用聚合酶链反应(PCR)扩增法,对20株PDRAB检测54种耐药基因与12种可移动遗传元件遗传标记,检测结果采用指标聚类分析(UPGMA法)获得性耐药基因及可移动遗传元件遗传标记的相关性.结果 20株PDRAB检出4种β-内酰胺类获得性耐药基因,A类检出TEM-1、PER,检出率分别为95.0％、25.0％,C类检出ADC-30,检出率为100.0％,D类检出OXA-23,检出率为100.0％.结论 该组菌株获得性耐药相关基因可导致相关抗菌药物耐药,可移动遗传元件的水平转移使细菌的耐药性在同种菌株及不同菌株间快速传播,UPGMA分析获得性耐药基因与可移动遗传元件高度相关.     

Bedeutung der Genetik beim Thema "soziale Ungleichheit und Gesundheit"

In Germany it has rarely been assessed in a systematic way, if and how genetic disposition and genetic testing are linked to health inequality. The paper aims to be a contribution towards closing this gap. In a first step, it is pointed out that the discussion about potential links between genetic causes of social inequalities has concentrated on issues such as body height and intelligence. It is stressed that, of course, social status is mainly determined socially and not genetically. In the second step, medical benefits of genetic testing are discussed. It can be assumed that low status groups are using these tests less often than high status groups, and that they are less capable of interpreting the results. Tests that can have a positive effect on health could thus lead to an increase of health inequalities. However, empirical studies for testing these hypotheses are hardly available. In the third step, the question is raised whether genetic information could lead to social discrimination (e.g. concerning health insurance, life insurance or employer). According to the current empirical literature, to date, this risk is (still) rather small. Thus, it is stressed that more research is needed, and that already today there is some need for intervention (e.g. concerning equal access to genetic testing, better information of low status groups).