Objectives. To investigate the genetic susceptibility for breast cancer of Chinese, a hospital-based case-control study, pedigree survey and molecular genetic study were conducted. Methods. Logistic regression model a...Objectives. To investigate the genetic susceptibility for breast cancer of Chinese, a hospital-based case-control study, pedigree survey and molecular genetic study were conducted. Methods. Logistic regression model and stratification methods were used in the risk factors analysis. Li-Mantel-Gart and Falconer methods were used to analyze the segregation ratio and heritability. Polymerase chain reaction(PCR) and polyacrylamide gel electrophoresis were used to detect AI, G-banding technique was used to detect the chromosome aberration of peripheral blood lymphocyte. Results. Family history of breast cancer is related to enhanced breast cancer risk significantly, OR is 3905(95%CI=1079～1413), and it widely interacts with other risk factors. Accumulative incidence of breast cancer in first degree relatives is 999%, which is larger than that in second, third degree and non-blood relatives. Segregation ratio is 0021, heritability among first degree relatives is 356±58%. Frequencies of LOH at BRCA1 and BRCA2 loci in sporadic breast cancer are 612% and 577% respectively. In the sibs, both of them show LOH at D13S173 locus, and high frequencies of chromosome aberrations were observed. Conclusions. Genetic susceptibility contributes to breast cancer occurrence of Chinese, and its racial variation may be one of the important reasons for the large difference of incidence between western and eastern countries.展开更多
To gain a better understanding of the genetic diversity and evolution of PRRSV in the Ningxia Hui Nationality Autonomous Region(Ningxia) of China,the nsp2 genes from a series of PRRSV strains collected from the region...To gain a better understanding of the genetic diversity and evolution of PRRSV in the Ningxia Hui Nationality Autonomous Region(Ningxia) of China,the nsp2 genes from a series of PRRSV strains collected from the region in 2007 were partially sequenced. These sequences were then analyzed along with the classical strain(ch-1a) and two other epidemic strains SD(3) and SD2006. Comparison of the nucleotide sequence with ch-1a indicated that nsp2 genes of seventeen Ningxia isolates(NX strain) have deletions of 87 nucleotides. Sequence analysis indicated that homology between the Ningxia strain and ch-1a was 60.3%-79.9% in the nucleotide sequence,and homology between the NX strains and SD strains was 80.3%-98.8% in the nucleotide sequence. The nsp2 genes of the seventeen isolates had 74.9%-100% nucleotide sequence identities with each other. This study was undertaken to assess the regional variation of prevalent PRRSV and to establish a sequence database for PRRSV molecular epidemiological studies.展开更多
文摘Objectives. To investigate the genetic susceptibility for breast cancer of Chinese, a hospital-based case-control study, pedigree survey and molecular genetic study were conducted. Methods. Logistic regression model and stratification methods were used in the risk factors analysis. Li-Mantel-Gart and Falconer methods were used to analyze the segregation ratio and heritability. Polymerase chain reaction(PCR) and polyacrylamide gel electrophoresis were used to detect AI, G-banding technique was used to detect the chromosome aberration of peripheral blood lymphocyte. Results. Family history of breast cancer is related to enhanced breast cancer risk significantly, OR is 3905(95%CI=1079～1413), and it widely interacts with other risk factors. Accumulative incidence of breast cancer in first degree relatives is 999%, which is larger than that in second, third degree and non-blood relatives. Segregation ratio is 0021, heritability among first degree relatives is 356±58%. Frequencies of LOH at BRCA1 and BRCA2 loci in sporadic breast cancer are 612% and 577% respectively. In the sibs, both of them show LOH at D13S173 locus, and high frequencies of chromosome aberrations were observed. Conclusions. Genetic susceptibility contributes to breast cancer occurrence of Chinese, and its racial variation may be one of the important reasons for the large difference of incidence between western and eastern countries.
文摘To gain a better understanding of the genetic diversity and evolution of PRRSV in the Ningxia Hui Nationality Autonomous Region(Ningxia) of China,the nsp2 genes from a series of PRRSV strains collected from the region in 2007 were partially sequenced. These sequences were then analyzed along with the classical strain(ch-1a) and two other epidemic strains SD(3) and SD2006. Comparison of the nucleotide sequence with ch-1a indicated that nsp2 genes of seventeen Ningxia isolates(NX strain) have deletions of 87 nucleotides. Sequence analysis indicated that homology between the Ningxia strain and ch-1a was 60.3%-79.9% in the nucleotide sequence,and homology between the NX strains and SD strains was 80.3%-98.8% in the nucleotide sequence. The nsp2 genes of the seventeen isolates had 74.9%-100% nucleotide sequence identities with each other. This study was undertaken to assess the regional variation of prevalent PRRSV and to establish a sequence database for PRRSV molecular epidemiological studies.
