Background:Werner syndrome (WS) is a rare autosomal recessive progeroid disorder caused by mutations of the WRN gene encoding a protein of the RecQ-type family of DNA helicases. Objectives:To develop a rapid and simpl...Background:Werner syndrome (WS) is a rare autosomal recessive progeroid disorder caused by mutations of the WRN gene encoding a protein of the RecQ-type family of DNA helicases. Objectives:To develop a rapid and simple reverse transcription-polymerase chain reaction (RT-PCR) strategy for mutation analysis of the WRN gene, to identify pathogenic mutations in a German patient with WS and to determine the effects of the pathogenic mutations on WRN mRNA stability. Methods:Allele-specific RT-PCR, semiquantitative RT-PCR, DNA sequencing. Results:We describe a novel and rapid RT-PCR-based method for mutation analysis in WS and report a German patient with WS carrying a previously reported (1396delA) as well as a novel nonsense mutation (2334delAC)of the WRN gene. By semiquantitative RT-PCR analysis we demonstrate that this compound heterozygous genotype leads to WRN transcript decay. Conclusions:In previous studies WS was primarily attributed to a loss of function of stable truncated WRN gene products. Our findings indicate that mutations can also lead to markedly decreased WRN transcript stability.展开更多
目的探讨中国汉族人群中DNA修复基因的拷贝数多态性(copy number variations,CNV)与年龄相关性白内障(age-related cataract,ARC)易感性的关系。方法研究对象来自"江苏眼病研究"流行病学人群,包括ARC组780例和对照组525人。...目的探讨中国汉族人群中DNA修复基因的拷贝数多态性(copy number variations,CNV)与年龄相关性白内障(age-related cataract,ARC)易感性的关系。方法研究对象来自"江苏眼病研究"流行病学人群,包括ARC组780例和对照组525人。采集受试者外周静脉血,提取全血基因组DNA。通过实时荧光定量PCR方法检测四种DNA修复基因的拷贝数(copy number,CN),分析ARC组和对照组基因CN的差异以及相对危险度(odds ratio,OR)。结果在WRN基因中发现了新的CNV。WRN基因高拷贝(CN=3+)与ARC的易感性有关(OR=1.88,P=0.02);HSF4基因低拷贝(CN=1)的人群对ARC易感(OR=4.09,P=0.004)。WRN基因高拷贝与核性以及后囊下性ARC的易感性有关(OR=2.06、3.72,均为P=0.02)。HSF4基因低拷贝与核性以及后囊下性ARC的易感性有关(OR=5.73,P=0.001;OR=6.80,P=0.01)。WRN和HSF4基因的联合作用显著增加了ARC的易感性。经过多重校正以后,仅有HSF4的CNV与ARC的易感性有关,尤其与核性和后囊下性ARC的易感性有关。结论 HSF4基因与WRN基因的CNV可能与中国汉族人群ARC的易感性有关。DNA修复基因对ARC易感性有一定的作用,并且对不同亚型ARC产生不同的影响。展开更多
1980年3月13日,IEEE批准了一个新的的工程802。IEEE 802由LAN/MAN Standard Committee(LMSC)负责。就无线通信而言,802 WG定义了802.11WLAN,802.15WPAN和802.16WMAN。与以前的无线技术一样,随着通信实体的距离的增大,数据的传输速率随...1980年3月13日,IEEE批准了一个新的的工程802。IEEE 802由LAN/MAN Standard Committee(LMSC)负责。就无线通信而言,802 WG定义了802.11WLAN,802.15WPAN和802.16WMAN。与以前的无线技术一样,随着通信实体的距离的增大,数据的传输速率随之降低。对新的应用层业务而言,无论距离多远,都必须要保障高的数据率。要克服链路速率的限制,必须密集地布置无线网路设备。WMN有助于克服当前的无线通信系统对有线主干网络的依赖,因为它们价格便宜并能保证新的无线应用。概括了WMN的发展历程和最新的发展动态,并指出了进一步的发展方向。展开更多
文摘Background:Werner syndrome (WS) is a rare autosomal recessive progeroid disorder caused by mutations of the WRN gene encoding a protein of the RecQ-type family of DNA helicases. Objectives:To develop a rapid and simple reverse transcription-polymerase chain reaction (RT-PCR) strategy for mutation analysis of the WRN gene, to identify pathogenic mutations in a German patient with WS and to determine the effects of the pathogenic mutations on WRN mRNA stability. Methods:Allele-specific RT-PCR, semiquantitative RT-PCR, DNA sequencing. Results:We describe a novel and rapid RT-PCR-based method for mutation analysis in WS and report a German patient with WS carrying a previously reported (1396delA) as well as a novel nonsense mutation (2334delAC)of the WRN gene. By semiquantitative RT-PCR analysis we demonstrate that this compound heterozygous genotype leads to WRN transcript decay. Conclusions:In previous studies WS was primarily attributed to a loss of function of stable truncated WRN gene products. Our findings indicate that mutations can also lead to markedly decreased WRN transcript stability.
文摘1980年3月13日,IEEE批准了一个新的的工程802。IEEE 802由LAN/MAN Standard Committee(LMSC)负责。就无线通信而言,802 WG定义了802.11WLAN,802.15WPAN和802.16WMAN。与以前的无线技术一样,随着通信实体的距离的增大,数据的传输速率随之降低。对新的应用层业务而言,无论距离多远,都必须要保障高的数据率。要克服链路速率的限制,必须密集地布置无线网路设备。WMN有助于克服当前的无线通信系统对有线主干网络的依赖,因为它们价格便宜并能保证新的无线应用。概括了WMN的发展历程和最新的发展动态,并指出了进一步的发展方向。
