Objective To analyze the genetic polymorphism of 5 STR loci (D12S304, D12S313, D12S1583, D12S1640 and D12S1708) on chromosome 12 in Chinese Han population. Methods EDTA-anticoagulated blood specimens were collected from unrelated individuals of Chinese Han population in Shaanxi province. DNA samples were extracted with the Wizard Genomic DNA purification Kit and were amplified by polymerase chain reaction (PCR) technique. The PCR products were analyzed by ABI 3100 Genetic Analyzer. Results All 5 loci were in Hardy-Weinberg equilibrium. Allele and genotype frequencies, heterozygosity, power of discrimination, polymorphism information content, probability of paternity exclusion and matching probability of each locus were calculated in Excel 2002. Conclusion They are complexloci with lots of evenly distributed alleles and high heterozygosity in Chinese Han population. Thus they are informative polymorphicloci and valuable DNA marker which represents a superior alternative to many established STRs.

Objective To analyze the genetic polymorphism of 6 STR loci (D12S358, D12S1675, D12S1663, D12S1697, D12S1725 and D12S1613) on chromosome 12 in Chinese Han population. Methods EDTA-blood specimens were collected from 153 unrelated individuals of Chinese Han population in Shaanxi province. Allele and genotype frequencies for the 6 STR loci were estimated and statistical parameters of polymorphism were calculated. Re sults 8 alleles and 18 genotypes, 10 alleles and 17 genotypes, 9 alleles and 15 genotypes, 12alleles and 29 genotypes, 12 alleles and 31 genotypes, 8 alleles and 11 genotypes were observed at D12S358, D12S1675, D12S1663, D12S1697, D12S1725 and D12S1613, respectively. No deviations of the observed allele frequency from Hardy-weinberg equilibrium expectations were found for any of these loci. The Heterozygotes of these 6 loci were 78.89%, 66.10%, 54.95%, 79.10%, 71.98% and 59.48%, respectively. It indicated the high genetic polymorphism of the loci in Chinese Han population. Conclusion The 6 STR loci belonged to the genetic marker system of high discriminutesation and high information in Chinese Han population and can be used in the study of gene-related diseases.

Objective According to the distr ibution of low selenium areas, low nutrition state of the residents and the affecting cartilage growth and articular cartilage of Kashin-Beck Disease (KBD), the chondrocyte differen tiation and differential expression of collagen types i, II and X in articular cartilage from Chinese mini-pigs treated with low selenium were investigated in order to gain in sight in to the effects of these condition son chondrocyte differen tiation in KBD cartilage. Me thods Eleven male juvenile mini-pigs, aged from 4 weeks to 6 weeks after birth, were divided in to 3 groups. The Secontent in the diet of the "low Se" group was 0.035mg/kg diet, and 0.175mg/kg diet in the control. For Se-supplemented group 0.390mg Na2SeO3/kg diet was added. The con tent of Sein blood was assayed at the beginning and at the end of each experiment. Samples of articular cartilage were taken from the right femur condylus, and collagen types I, II and "in articular cartilage were analyzed by immunohistochem istry and in situ hybridization. Results ①All cartilage samples from juven ilem in i-pigs fed with low selenium dietrevealed areduction in type "collagen mRNA expression in the hypertrophic chondrocytes as shown by in situ hybridization, and reduced type "collagen depos ition in the lower hypertrophic zone as shown by immunohistochem istry. ②Addition of selenium to the dietrestored the type" collagen to normal level. ③Type collagen was evenly distr ibuted over the entire articular cartilage in all experimental and controlgroups. Type collagen mRNA signals weremost prominent in the upper articular layer as well as in the hypertrophic zone in all groups. Type collagen express ion was restricted to the zone of endochondraloss if ication in all experimental groups and the control. Conclusion　Low selen ium has an down-regulatoryrole on the syn thes is and deposition of collagen type "in hypertrophic chondrocytes in articular cartilage of mini-pigs. Supplement of the low Sediet with additional Serestored the signals of collagen type" to normal levels. These findings indicate that selenium deficiency may disturb chondrocyte differen tiation to hypertrophic cells in the growth plate, and worthy to be investigated further.

目的 分析大骨节病核心家庭的发病特点。方法 应用临床诊断搜集大骨节病核心家庭，根据父母患大骨节病情况将4938个核心家庭分为四种类型，结合病区类型，分析轻、中、重病区内不同核心家庭子代患病率及其家庭聚集性。结果 （1）核心家庭类型与病区类型的轻重有关；（2）中、重病区核心家庭子1代患病具有家庭聚集性；（3）仅双亲和父亲患大骨节病的核心家庭子1代具有明显的家庭聚集性；（4）双亲患大骨节病的核心家庭的子1代患病率明显高于单亲或双亲不患大骨节病的核心家庭。结论 大骨节病病区人群的患病除了与轻、中、重病区的类型有关，还可能与核心家庭双亲患大骨节病的情况有关。