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871.
To identify susceptibility alleles associated with rheumatoid arthritis, we genotyped 397 individuals with rheumatoid arthritis for 116,204 SNPs and carried out an association analysis in comparison to publicly available genotype data for 1,211 related individuals from the Framingham Heart Study. After evaluating and adjusting for technical and population biases, we identified a SNP at 6q23 (rs10499194, approximately 150 kb from TNFAIP3 and OLIG3) that was reproducibly associated with rheumatoid arthritis both in the genome-wide association (GWA) scan and in 5,541 additional case-control samples (P = 10(-3), GWA scan; P < 10(-6), replication; P = 10(-9), combined). In a concurrent study, the Wellcome Trust Case Control Consortium (WTCCC) has reported strong association of rheumatoid arthritis susceptibility to a different SNP located 3.8 kb from rs10499194 (rs6920220; P = 5 x 10(-6) in WTCCC). We show that these two SNP associations are statistically independent, are each reproducible in the comparison of our data and WTCCC data, and define risk and protective haplotypes for rheumatoid arthritis at 6q23.  相似文献   
872.
Phytochrome signalling is mediated through nucleoside diphosphate kinase 2.   总被引:24,自引:0,他引:24  
G Choi  H Yi  J Lee  Y K Kwon  M S Soh  B Shin  Z Luka  T R Hahn  P S Song 《Nature》1999,401(6753):610-613
Because plants are sessile, they have developed intricate strategies to adapt to changing environmental variables, including light. Their growth and development, from germination to flowering, is critically influenced by light, particularly at red (660 nm) and far-red (730 nm) wavelengths. Higher plants perceive red and far-red light by means of specific light sensors called phytochromes(A-E). However, very little is known about how light signals are transduced to elicit responses in plants. Here we report that nucleoside diphosphate kinase 2 (NDPK2) is an upstream component in the phytochrome signalling pathway in the plant Arabidopsis thaliana. In animal and human cells, NDPK acts as a tumour suppressor. We show that recombinant NDPK2 in Arabidopsis preferentially binds to the red-light-activated form of phytochrome in vitro and that this interaction increases the activity of recombinant NDPK2. Furthermore, a mutant lacking NDPK2 showed a partial defect in responses to both red and farred light, including cotyledon opening and greening. These results indicate that NDPK2 is a positive signalling component of the phytochrome-mediated light-signal-transduction pathway in Arabidopsis.  相似文献   
873.
Loss of p16Ink4a with retention of p19Arf predisposes mice to tumorigenesis.   总被引:39,自引:0,他引:39  
The cyclin-dependent kinase inhibitor p16INK4a can induce senescence of human cells, and its loss by deletion, mutation or epigenetic silencing is among the most frequently observed molecular lesions in human cancer. Overlapping reading frames in the INK4A/ARF gene encode p16INK4a and a distinct tumour-suppressor protein, p19ARF (ref. 3). Here we describe the generation and characterization of a p16Ink4a-specific knockout mouse that retains normal p19Arf function. Mice lacking p16Ink4a were born with the expected mendelian distribution and exhibited normal development except for thymic hyperplasia. T cells deficient in p16Ink4a exhibited enhanced mitogenic responsiveness, consistent with the established role of p16Ink4a in constraining cellular proliferation. In contrast to mouse embryo fibroblasts (MEFs) deficient in p19Arf (ref. 4), p16Ink4a-null MEFs possessed normal growth characteristics and remained susceptible to Ras-induced senescence. Compared with wild-type MEFs, p16Ink4a-null MEFs exhibited an increased rate of immortalization, although this rate was less than that observed previously for cells null for Ink4a/Arf, p19Arf or p53 (refs 4, 5). Furthermore, p16Ink4a deficiency was associated with an increased incidence of spontaneous and carcinogen-induced cancers. These data establish that p16Ink4a, along with p19Arf, functions as a tumour suppressor in mice.  相似文献   
874.
After the renal cell carcinoma related novel gene fragmentGYLZ-RCC18 was cloned by using suppression subtractive hybridization (SSH), we used the SMART RACE technology to clone the full length ofGYLZ-RCC18 and performed chromosome location by the FISH method. RT-PCR was used to detect the expression of the first reading frame ofGYLZ-RCC18 in different stages and grades of renal cell carcinoma tissue and other tissues. Also we transfected the antisense oligonucleotide ofGYLZ-RCC18 to renal cell carcinoma cell line GRC-1, and analyzed the proliferation activity, growth speed, apoptosis and mortality changes in GRC-1. The results show that the full length ofGYLZ-RCC18 (GenBank accession No.: BE825133) cDNA is about 3.5 kb long which is located at No. 14 chromosome.GYLZ-RCC18 has a higher expression in higher grades and stages of renal cell carcinoma than in the lower ones. The expression ofGYLZ-RCC18 in renal cell carcinoma was much higher than that in normal kidney and other tissues. After transfection ofGYLZ-RCC18 antisense oligonucleotide, the mortality of GRC-1 increases evidently, the proliferation activity and growth speed were inhibited remarkably at the same time. Also the antisense oligonucleotide can induce the apoptosis of GRC-1 all through the observation time. Our results indicated thatGYLZ-RCC18 is an important novel gene related to renal cell carcinoma. Its overexpression would stimulate the growth and proliferation activity and plays an antidead and antiapoptosis effect in renal cell carcinoma. Transfection of antisense oligonucleotide could inhibit the generation and development of renal cell carcinoma. The study provides a new clue for the research of renal cell carcinoma, and also provides an instruction for special genetic diagnosis and the therapy of renal cell carcinoma.  相似文献   
875.
内蒙古草地挥发性有机物的预研究   总被引:4,自引:1,他引:3  
内蒙古草原挥发性有机物的研究在大气化学、大气环境领域具有重要的作用。2001年夏季,利用便携式光离子化检测器以及采样仪器对于内蒙古草原的一些优势草种进行了测量,得到了对内蒙古草原挥发性有机物的初步认识。  相似文献   
876.
Manpower forecasting has made significant contributions to human resource management. Due to difficulties in collecting the required data for making appropriate analysis, most studies in the literature concentrate on forecasts of individual firms. This paper presents a regression model which utilizes the data of large firms to draw inferences to the demands of other firms. More specifically, a regression model showing the negative relationship between the rank of a firm and its associated demand is fitted to the data of a number of large manufacturing firms. The area under the regression line delineated by the y-axis is then an estimate of the total demand of the whole industry. Confidence intervals for the estimate can also be constructed. As an illustration, the demand for the industrial management manpower in Taiwan is forecasted by applying the proposed model.  相似文献   
877.
 循环肿瘤细胞(CTCs)因携带原发肿瘤的一些生物特性以及自身独特的生物学功能,在癌症的诊断、治疗和转移预防方面发挥着重要作用.但外周血中CTCs 的低含量使其检测、分离和富集有一定技术难度.本文选取结肠癌HT29 细胞为CTCs 模型,以表面高表达的EpCAM 为生物标记物,选取纳米级高分子聚合物G6 PAMAM dendrimers 为基质,多价络合针对EpCAM的抗体来构建络合物,实现体外对HT29 细胞的特异性捕获及活性调控.应用红外、动态光散射、紫外和荧光等方法表征络合物的理化特性,荧光分析法考察络合物对HT29 细胞的识别和捕获,MTT、荧光拍照、流式分析法显示络合物对捕获的HT29 细胞的活性调控.结果表明,制备的络合物可以高特异性地识别和结合贴壁的和悬浮的HT29 细胞,从而对捕获的细胞产生一定的活性下调作用,但不产生严重的细胞毒效应.可见,利用具有多价络合效应的纳米材料来共价连接针对CTCs 表面标记物的靶向抗体,有望实现在病人血中对CTCs 的特异性捕获和活性调控.  相似文献   
878.
879.
黄灯期间信号交叉口的驾驶员行为   总被引:2,自引:0,他引:2  
交叉口安全评价、信号方案设计等工作中必须考虑黄灯期间驾驶员的行为特性,为此需要构建合理的驾驶员行为模型。针对黄灯期间信号交叉口的驾驶员行为模型进行研究,利用视频采集驾驶员在黄灯期间的行为数据,经数据预处理后,考虑黄灯启亮时刻车辆位置、车速两个因素,运用Logistic回归构建了驾驶员行为模型,并利用受试者工作特征曲线(ROC曲线)等检验了模型的准确性。  相似文献   
880.
为了研究地下圆形衬砌洞室在入射平面SV波和Rayleigh波作用下的动应力集中问题,利用波函数展开法,求解出三维条件下的级数解.当衬砌与半空间介质相同时,级数解将退化为无衬砌时的结果.级数解为进一步定量分析衬砌洞室对入射平面SV波和Rayleigh波的动力集中提供了理论基础.  相似文献   
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