基于美欧医疗器械上市后法规要求对我国建立医疗器械警戒制度的思考

本文旨在深入探讨美国和欧盟的医疗器械上市后监管制度,包括风险监管理念、监管法规体系、上市后临床研究、质量管理体系等,总结出开发风险监测工具、落实风险管理、采用合并报告模式、公开风险信息等经验,为我国医疗器械行业有序发展提供参考。我国可以借鉴美欧医疗器械上市后的监管实践,从提高监管机构能力、建设监测哨点和强化法规框架等方面,建立和试点医疗器械警戒制度。

一种适用于高通量基因分型的水稻种子切片DNA制备技术

建立一种高质量、低成本的水稻种子切片DNA制备方法,用于育种群体的高通量基因分型。通过对比TPS法提取水稻叶片DNA及96孔板结合磁珠法提取切片种子DNA的纯度和浓度,进一步采用STARP(Semi-thermal asymmetric PCR)标记检测验证96孔板结合磁珠法提取水稻切片种子DNA的质量。结果表明:96孔板结合磁珠法提取水稻种子切片的DNA质量和纯度优于TPS法提取水稻叶片的DNA质量;STARP标记检测验证结果显示96孔板结合磁珠法提取水稻切片种子DNA可适用于GS3、Wx的STARP标记基因分型,其鉴定结果与测序结果一致。研究显示96孔板结合磁珠法可以从微量水稻种子切片中提出高回收率、高纯度、高完整度、无PCR抑制物的DNA用于高通量STATP法基因单倍型分析,可获得一种96孔板结合磁珠法提取DNA的高通量基因分型操作流程。

Abundance and Community Composition of Ammonia-Oxidizers in Paddy Soil at Different Nitrogen Fertilizer Rates

Ammonia oxidation, the first and rate-limiting step of nitrification, is carried out by both ammonia-oxidizing bacteria （AOB） and ammonia-oxidizing archaea （AOA）. However, the relative importance of AOB and AOA to nitrification in terrestrial ecosystems is not well understood. The aim of this study was to investigate the effect of the nitrogen input amount on abundance and community composition of AOB and AOA in red paddy soil. Soil samples of 10-20 cm （root layer soil） and 0-5 cm （surface soil） depths were taken from a red paddy. Rice in the paddy was fertilized with different rates of N as urea of N1 （75 kg N ha＂ yr-1）, N2 （150 kg N ha~ yrl）, N3 （225 kg N ha1 yrl） and CK （without fertilizers） in 2009, 2010 and 2011. Abundance and community composition of ammonia oxidizers was analyzed by real-time PCR and denaturing gradient gel electrophoresis （DGGE） based on amoA （the unit A of ammonia monooxygenase） gene. Archaeal amoA copies in N3 and N2 were significantly （P〈0.05） higher than those in CK and N1 in root layer soil or in surface soil under tillering and heading stages of rice, while the enhancement in bacterial amoA gene copies with increasing of N fertilizer rates only took on in root layer soil. N availability and soil NO3--N content increased but soil NH4＋-N content didn＇t change with increasing of N fertilizer rates. Otherwise, the copy numbers of archaeal amoA gene were higher （P〈0.05） than those of bacterial amoA gene in root lary soil or in surface soil. Redundancy discriminate analysis based on DGGE bands showed that there were no obvious differs in composition of AOA or AOB communities in the field among different N fertilizer rates. Results of this study suggested that the abundance of ammonia-oxidizers had active response to N fertilizer rates and the response of AOA was more obvious than that of AOB. Similarity in the community composition of AOA or AOB among different N fertilizer rates indicate that the community composition of ammonia-oxidizers was relatively stable in the paddy soil at least in short term for three years.

Changes in bacterial community and abundance of functional genes in paddy soil with cry1Ab transgenic rice

A field experiment involving cry1Ab transgenic rice(GM) and its parental non-cry1Ab rice(M) has been on-going since 2014. The diversity of the bacterial communities and the abundance of the microbial functional genes which drive the conversion of nitrogen in paddy soil were analyzed during the growth period of rice in the fifth year of the experiment, using 16 S rRNAbased Illumina Mi Seq and real-time PCR on the amoA, nirS and nirK genes. The results showed no differences in the alpha diversity indexes of the bacterial communities, including Chao1, Shannon and Simpson, between the fields cultivated with line GM and cultivar M at any of the growth stages of rice. However, the bacterial communities in the paddy soil with line GM were separated from those of paddy soil with cultivar M at each of the growth stages of rice, based on the unweighted Uni Frac NMDS or PCoA. In addition, the analyses of ADONIS and ANOSIM, based on the unweighted Uni Frac distance, indicated that the above separations between line GM and cultivar M were statistically significant(P<0.05) during the growth season of rice. The increases in the relative abundances of Acidobacteria or Bacteroidetes, in the paddy soils with line GM or cultivar M, respectively, led to the differences in the bacterial communities between them. At the same time, functional gene prediction based on Illumina Mi Seq data suggested that the abundance of many functional genes increased in the paddy soil with line GM at the maturity stage of rice, such as genes related to the metabolism of starch, amino acids and nitrogen. Otherwise, the copies of bacterial amo A gene, archaeal amo A gene and denitrifying bacterial nir K gene significantly increased(P<0.05 or 0.01) in the paddy soil with line GM. In summary, the release of cry1Ab transgenic rice had effects on either the composition of bacterial communities or the abundance of microbial functional genes in the paddy soil.

Diversity of Microbial Community in a Paddy Soil with cry1Ac/cpti Transgenic Rice

Two types of crylAc/cpti transgenic rice （GM1 and GM2） and their parental non-crylAc/cpti rice （CK1 and CK2） were planted in the field at Wufeng, Fhjian Province, China for four years to investigate the influence of genetically modified rice on diversity of bacterial and fungal community in the paddy soil. The community composition and abundance of bacteria or fungi in the paddy soil were assessed at different growth stages of rice by denaturing gradient gel electrophoresis and real-time polymerase chain reaction based on 16S rRNA gene or SSU rRNA gene in the 4th year after the experimental establishment. The composition of bacterial or fungal community changed during rice growth, while no significant differences were observed between the fields cultivated with GM1 and CK1, or between the fields cultivated with GM2 and CK2 in either bacterial or fungal community composition. The copy numbers of bacterial 16S rRNA gene in the soils with CK1, CK2, GM1 and GM2 ranged from 5.64 x 10i1 to 6.89 x 10li copies g-1 dry soil at rice growth stages, and those of fungal SSU rRNA gene from 5.24 x 10s to 8.68 x l0s copies g-1 dry soil. There were no marked differences in the copies of bacterial 16S rRNA gene or fungal SSU rRNA gene between CK1 and GM1 or between CK2 and GM2 at any growth stage of rice. Planting crylAc/cpti transgenic rice had no significant effect on composition and abundance of bacterial and fungal community in paddy soil during the rice growing season at least in the short term.