Objective:To establish the technique for T lymphocytes inducted and differentiated by using human hematopoietic stem/progenitor cells ex vivo and to provide a technological platform for studying T cells biological characteristics and cellular immune.Methods:Human CD34-positive cells were isolated from umbilical cord blood by using a high-gradient magnetic cell sorting system(MACS) and CD34+ cells were seeded on human fetal thymic stromal monolayer system.Liquid culture system contains hematopoietic cytokines(FL+IL-12+IL-7+IL-2) and 20% human AB serum.Non-adhension cells were obtained after 7?14?28?35?42 days of culture respectively to analysis T cells phenotype by FACS using T cells specific monoclonal antibody.T cells morphology were also studied.Results:After 2 weeks of culture CD4+CD8+ immature T lymphocytes wre about 0 3%～13 3% and the peak value is 16 6%～26 5% at 4～5 weeks of culture.CD4-CD8+ and CD4+CD8- T cells that coexpressed CD3 cells increased at 26 5%～64 9% and 11 6%～38 9% after 6 weeks of culture.Wright staining shows that the mature T cells harvested after mitogenic stimulation have the presence of large cells with lymphoblast morphology.Conclusion:Human umbilical cord blood CD34+ cells could be differentiated into T lymphocytes by the culture conditions of human fetal thymic stromal monolayer system and the cytokine combination of FL+IL-12+IL-7+IL-2,and the T cells can be stimulated by IL-2+PHA.

Objective To investigate the significance of the mutation of c-kit gene in the development,(clinical) pathology and prognosis of gastrointestinal stromal tumors(GISTs).Methods The technique of(PCR-SSCP) was used to detect ckit gene mutation in 106 cases of GIST,and 57 of the cases were(followed-up).Results The c-kit gene mutation rate in the whole group was 45.3%(48/106),and(3.4)%(2/41) in benign GIST,and 70.8%(46/65) in malignant GIST.The 1-,3 and 5-year survival rates and median survival time of the mutation positive group were all markedlly lower than those of the(mutation) negative group.A comparison of the parameters that can differentiate the benign GISTs from malignant ones such as size,histological necrosis,aggressive grade,nucleus mitotic count and nuclear discrepancy,showed significant difference between the of postive and negative gene mutation(P

Objective:To study the differentiation capacity of the fibroblast-like cells isolated from human skin dermis into mesenchymal stem cells, and to explore the feasibility to use these cells as alternative cell source of autologus bone marrow mesenchymal stem cells (BMSCs ) for regeneration of tissue inj uries and defects. Methods:Full thickness skin samples were obtained from the abdomen of surgical patients, then digested with dispase and collagenase Ⅰ subsequently. Thereafter, the digested cells were collected and cultured, followed by suspension with serum free medium containing N2,B27,basic fibroblast growth factor (bFGF),and epidermal growth factor (EGF).The skin dermis derived spheroids (SDDSs)were collected and monolayer cultured in serum-containing medium.Finally,the cells were characterized by immunofluorescence staining and differentiation assays.Results:The dermis derived cells proliferated and formed SDDSs in the suspension of serum-free medium. After monolayer cultivation in serum-containing medium, the cells from spheroids were successfully expanded to large number. The cells expressed mesenchymal stem cells markers CD90, CD105 and vimentin. Under osteogenic,chondrogenic and adipogenic differentiation conditions,these cells were differentiated into the alizarin red,safranin O, and oil red O staining positive cells, displayed similar differentiation traits with BMSCs. However,safranin O staining was weaker in the dermis derived cells than BMSCs. Conclusion:A kind of fibroblast-like cells exist in human skin dermis, and have osteocytic, chondrogenic and adipogenic differentiation potentials,demonstrating that these cells will be utilized as a novel cell source for repairing the tissue injury and defect in clinic.