中国癌症与土壤中钼元素的关系

利用土壤中钼元素资料 110 376个数据 ,癌死亡调查资料 7870 80例 ,研究了胃癌、食管癌、肝癌、宫颈癌、肺癌、大肠癌、白血病、鼻咽癌、乳腺癌死亡率与人群生存区土壤环境中钼元素的关系。结果表明 ,胃癌、食管癌、宫颈癌死亡率与钼元素有相关性 ,等级相关系数分别为 - 0 .4 2 4 6( P<0 .0 2 5) ,- 0 .54 53( P<0 .0 0 2 5) ,- 0 .3369( P<0 .0 5)。     

Relative Contribution of Inbreeding Depression and Eroded Adaptive Diversity to Extinction Risk in Small Populations of Shore Campion

Abstract:  To study the relative importance of inbreeding depression and the loss of adaptive diversity in determining the extinction risk of small populations, we carried out an experiment in which we crossed and self-fertilized founder plants from a single, large population of shore campion ( Silene littorea Brot.). We used the seeds these plants produced to colonize 18 new locations within the distribution area of the species. The reintroduced populations were of three kinds: inbred and genetically homogeneous, each made up of selfed seed from a single plant; inbred and mixed, made up of a mixture of selfed seeds from all founder plants; and outbred and mixed, made up of a mixture of seeds obtained in outcrosses between the founders. We compared the inbred homogeneous populations with the inbred mixed to measure the effect of genetic diversity among individuals and the inbred mixed with the outbred mixed to measure the effect of inbreeding. Reintroduction success was seriously limited by inbreeding, whereas it was not affected by genetic diversity. This observation and the nonsignificant interaction between family and reintroduction location for individual plant characters suggest that the fixation of overall deleterious genes causing inbreeding depression posed a more serious threat to the short-term survival of the populations than the loss of genes involved in genotype and environment interactions. Thus, reintroduction success was related to adaptive diversity. Preventing such fixation might be the most important consideration in the genetic management and conservation of shore campion populations.     

东南沿海珍珠岩矿床及其成因

本区珍珠岩矿床主要产于中生代Ⅲ、Ⅳ旋回初始期和复活期的火山岩中,形成于活动大陆边缘的扩张阶段,是“陆壳改造型”岩浆强烈分异的产物,矿床类型可分为牛台式和白水洋式。珍珠岩具有异常高的δ~(18)O值,它取决于低温时水—岩同位素交换反应。珍珠岩中Cs矿化十分显著。珍珠岩水的结构种及含量是决定膨胀倍的主要因素。     

Prenatal molecular diagnosis in hypertrophic cardiomyopathy: report of the first case

Hypertrophic cardiomyopathy (HCM) is an autosomal dominant disease that may cause premature sudden death, especially in teenagers and young adults. The recent progress in the molecular genetics of the disease has made genetic testing sometimes available in clinical practice. We report the case of a couple who still requested prenatal molecular testing after detailed information had been given through a multidisciplinary consultation. Prenatal diagnosis in HCM is associated with complex medical and psychological implications, in addition to general ethical considerations, as the potential value of the diagnosis is counterbalanced by the highly variable expression of the disease and the difficulty in predicting its evolution. The R403L mutation in the MYH7 gene had been previously identified in this family, characterized by a malignant form of HCM. In the specific context of this case, we decided to agree to the request of the parents and performed the prenatal diagnosis. To the best of our knowledge, this is the first report of a prenatal molecular diagnosis performed in the context of HCM. Copyright © 2004 John Wiley & Sons, Ltd.     

First application of preimplantation genetic diagnosis to neurofibromatosis type 2 (NF2)

Neurofibromatosis type 2 (NF2) is a dominantly inherited cancer predisposition syndrome that is caused bymutations in the NF2 gene. We report here the first clinical preimplantation genetic diagnosis (PGD) forNF2. A protocol was developed to simultaneously amplify the mutation and a single nucleotide polymorphism (SNP) located within the gene. The mutation and polymorphism were analysed by simultaneous fluorescent single-strand conformation polymorphism (SSCP) on an automated DNA sequencer. The mutation, carried by the male partner, was a single base pair substitution affecting a splice site in intron 4 of the gene. The female partner was infertile due to polycystic ovary syndrome and would require IVF to conceive. The couple was found to be informative at a linked intragenic SNP situated in the 5′ untranslated region of the gene. The SNP was included in the assay to reduce the risk of misdiagnosis due to allele dropout (ADO). The couple underwent three cycles of treatment during which a total of 43 blastomeres were biopsied from 31 embryos. Amplification at both loci was obtained in 35 cells (81%). A total of five embryos were transferred, two in the first cycle, two in the second and one in the third. No pregnancy ensued. The results of the diagnoses indicated that, in this couple, the inheritance of the mutation may be non-Mendelian. Out of a total of 32 embryos tested only four were found not to carry the mutation. The reasons for this apparent skew remain unknown. Copyright © 2002 John Wiley & Sons, Ltd.     

环境生物技术在微污染源水中的应用与展望

常规水处理难以有效去除微污染源水，以微生物选育、培养技术、遗传基因为基础的环境生物技术在微污染源水中起着重要的作用。分析了环境生物技术在开发基因工程菌、生物修复中的应用及潜力。