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.

To investigate the effect of excessive fluoride ingestion (EFI) on the differential expression of collagen phenotypes and chondrocyte differentiation in cartilage, 60 Sprague-Dawley rats, 4-6 weeks old, were divided into three groups and exposed to O (control), 50, and 100 ppm fluoride (from NaF) in drinking water for 3 to 5 months. Correlating with the increased F in the serum and bone in the two groups exposed to EFI, chondrocytes in the proliferative and hypertrophic zones of growth plate cartilage (GPC) and rib cartilage (RC) were retained and formed a mixture tissue of cartilage peninsulas or islands with ossified islands in the deep zone of GPC and RC. Staining reactions for types II and X collagen were increased in the over-thickened region of GPC and were decreased in RC. Type X collagen staining reactions were also increased in the upper and middle zones in articular cartilage (AC) of tibia in the higher fluoride (EFI-II) group. Abnormal collagen expression in rats of the EFI groups resulted from abnormal differentiation of chondrocytes in proliferative and hypertrophic zones in GPC and RC and from degenerative changes in AC of rats in the EFI groups. Four types of abnormal chondrocyte differentiation in hyaline cartilage of rats with skeletal fluorosis (SF) suggested two pathogenic mechanisms for early stage of SF: osteomalacia-like changes in GPC and RC coupled with delayed mineralization and degenerative changes in AC.

目的 探讨大骨节病患者关节软骨细胞凋亡及相关调控因子Bcl-2表达分布的特点。方法 采用脱氧核糖核酸末端转移酶介导的脱氧核糖核酸缺口标记法（TUN EL氏法）检测凋亡阳性细胞，利用单克隆抗体免疫组化检测Bcl-2在关节软骨中的表达。结果 ①TUN EL法染色的大骨节病儿童关节软骨凋亡阳性细胞数较正常关节软骨增多，且主要分布在中层。②大骨节病儿童关节软骨Bcl-2的表达显著高于正常关节软骨中的表达，以表层最多，其次为中层；成人晚期大骨节病患者剥蚀的关节软骨表层Bcl-2的表达聚集在软骨细胞团中。结论 大骨节病患者关节软骨细胞凋亡及相关调控因子Bcl-2表达较正常人显著增多。

目的 探索甲状旁腺激素相关肽（PTH rP）在大骨节病儿童及成人关节软骨中的表达及分布。方法 应用免疫组化方法比较正常儿童和成人与大骨节病儿童和成人关节软骨中PTH rP的表达。结果 ①大骨节病儿童关节软骨表层、中层、深层PTH rP阳性细胞表达率分别为30%、24% 和31%，中层、深层表达率比正常儿童明显增高（P<0.01）；②大骨节病成人关节软骨表、中、深层PTH rP阳性细胞表达率分别为54%、46% 和16%，各层细胞阳性表达率均明显高于正常组（P<0.01）。③大骨节病儿童与成人比较各层软骨细胞PTH rP的阳性表达差异均有显著意义（P<0.01），表现为表、中层成人高于儿童，深层儿童高于成人。结论 大骨节病患者关节软骨中PTH rP阳性表达率高于正常对照。

We sought to determine whether transplanted allogeneic bone mesenchymal stem cells can survive and increase the amount of proteoglycans in intervertebral discs. We used the rabbit intervertebral disc as a model, creating three groups: an uninjected control group, a group injected with saline, and a group injected with 1