To study the feasibility of spermatogonial stem cell allotransplantation.

To study the effect of panax notoginsenosides (PNS) on the proliferation of hematopoietic progenitor cells (HPC) in mice with immune-mediated aplastic anemia.

To investigate the effect of basic fibroblast growth factor(bFGF) gene transfection on the proliferation and differentiation of mesenchymal stem cells (MSCs) and to provide basis for accelerating bone defect repairing using gene-enhanced tissue engineering technology, Rabbit periosteum-derived MSCs were transfected with the full-length rat bFGF cDNA in vitro. The transient and stable gene expression of bFGF were determined by immunohistochemistry. The proliferation and the synthesis alkaline phosphatase (ALP) and osteocalcin(OC) of the transfected MSCs were also examined. The results showed that bFGF cDNA could be transferred into osteoblasts and expressed stably at least 4 weeks. The proliferation and OC content of genetically modified MSCs were increased significantly, whereas the ALP activity remained no change. In conclusion, transfer of gene encoding bFGF to MSCs increases its proliferation and osteogenesis property. Based on the successful conjunction of the existing techniques of tissue engineering with the novel possibilities offered by modern gene transfer technology, an innovative concept, molecular tissue engineering, was put forward for the first time. As a new branch of tissue engineering, it represents both a new area and an important trend in tissue engineering research.

To evaluate the effect of bone morphogenetic protein (BMP) on the biological behavior of bone marrow stem cells (BMSCs) of rabbits.

To establish a method for the isolation of porcine mesenchymal stem cells (MSCs) from bone marrow and to demonstrate their differentiation ex vivo into various mesenchymal tissue cells.

To investigate the characteristic and phenotype of ectomesenchymal stem cells of human fetal facial processes and the procedure of spontaneous differentiation to smooth muscle cells.

To investigate the selection and identification of human keratinocyte stem cells(KSC) in vitro.

To investigate the feasibility of transplanting cord blood CD133+ cells derived endothelial progenitor cells (EPC) in therapeutic vasculogenesis.

To study the cellular expression of CD45RO, CD20, CD68 and proliferating cell nuclear antigen (PCNA) in nasal polyps.

Human fetal pancreatic nestin positive cells cultured in vitro could self assemble to form islet-like cell clusters(ICC). They are multipotential and are capable of generating insulin-producing cells. To investigate their biological character and physiological function in vivo, ICCs were implanted into NOD-Scid mice subcapsularly. The results showed that: (1) Neovascularizations were observed in implant sites. (2) Blood glucose levels of diabetic mice were reduced markedly after implantation of ICCs. (3) ICCs in non-diabetic mice proliferated abnormally and infiltrated into renal parenchyma with many cell structures formed.

The objective of this research was to explore whether the number of CD34(+)CD38(+) cells infused affects hematopoietic reconstitution after cord blood transplantation. The number of CD34(+)CD38(+) cells in cord blood was analysed with flow cytometry after freezethawing. The body weight and time for neutrophil and platelet recovery were measured in 20 children with acute leukemia. The results showed that the median number of CD34(+)CD38(+) cells infused was 29.47 (9.85 - 325.71) x 10(4)/kg. A median time for neutrophil recovery (> 5 x 10(8)/L) in 20 patients was 18.5 (11 - 32) days, and time for platlet recovery (> 2 x 10(10)/L) in 19 of 20 patients was 45 (12 - 118) days. The number of CD34(+)CD38(+) cells infused correlated with time to neutrophil and platelet recovery (r = -0.577, P < 0.01 and r = 0.503, P < 0.05, respectively). In conclusion, the number of CD34(+)CD38(+) cells infused is correlated with the time for hematologic recovery.

To evaluate the effects of rhG-CSF and rhSCF on mobilization of the peripheral blood stem cells, 15 monkeys were divided into control, rhG-CSF 10 micro g/(kg x day) and rhG-CSF 10 micro g/(kg x day) + rhSCF 50 micro g/(kg x day) treated groups. Monkeys were administered with vehicle, rhG-CSF and rhG-CSF + rhSCF subcutaneously once daily for 14 days, respectively. The results showed that the highest counts of leukocyte of rhG-CSF treated group were 411% of baseline value on day 7 after administration, compared with that of rhG-CSF + rhSCF treated group which were 538% on day 9. The highest counts of leukocytes lasted for 3 days in combined treated group. CFU-GM from peripheral blood in the two groups were 8.37 and 11.75 times higher at 5 and 9 days respectively after the mobilization. It is concluded that rhG-CSF significantly increases the number of peripheral blood leukocytes and CFU-GM, and a better effect can be obtained by rhSCF + rhG-CSF combined administration.

The blast colony-forming cells (BL-CFC), which are detected within embryoid bodies derived from embryonic stem cells (ES cells) differentiated for 2.5-3.5 days, have dual-potential of differentiation to hematopoietic and endothelial cells. In this investigation the culture method of BL-CFC was established and colony forming assay, immunofluorescent technique as well as nested RT-PCR was employed to identify the differentiation capacity of adherent and nonadherent cells derived from individual blast colony. The results showed that the adherent cells could intake DiI-Ac-LDL and expressed the endothelium-specific surface markers including CD31, UEA-I and VE-cadherin. In addition, nonadherent cells were capable of developing primitive or/and definitive hematopoiesis potential. High proliferative potential colony-forming cells (HPP-CFC) bearing self-renewal capacity was found in 20% of BL-CFC. It is concluded that BL-CFC derived from embryonic stem cells can generate high proliferative potential hematopoietic progenitor cells. However, the whether BL-CFC can reconstitute the adult bone marrow hematopoiesis in long-term remains to be further determined.

The object of this study was to explore the effect of FL gene transfected marrow stromal cells on expansion of human cord blood CD34(+) cells ex vivo. A co-culture system was established with FL gene transfected human marrow stromal cells and cord blood CD34(+) cells. The CD34(+) cells were cultured in different culture systems with different combinations of stromal cells and SCF, IL-3 and FL. The numbers of total nucleated cells, CFCs and CD34(+) cells were repeatedly counted in culture systems for 3 weeks. The results showed that the FL transgenic marrow stromal cell feeder layer significantly enhanced the expansion of total nucleated cells, CFC and CD34(+) cells, compared with stromal cell feeder layer and stromal cell-free culture systems. The transgenic stromal cells and cytokines co-culture system manifested the most potent expansion of the cord blood cells with increase of the number of total nucleated cells by (122.5 +/- 4.3)-fold, CFCs by (39.6 +/- 2.7)-fold and CD34(+) cells by (11.8 +/- 0.52)-fold. It is concluded that human umbilical cord blood CD34(+) cells can be extensively expanded ex vivo by using FL gene transfected stromal cells combined with cytokines.

To study enhancing effect of IL-3 gene transfected bone marrow stromal cell which can be induced by doxycycline (Dox) to express IL-3 cytokine on the proliferation and differentiation of hematopoietic stem cell, retrovirus vector system contained mIL-3 cDNA was established and bone marrow stromal cell line was transfected, and obtained QXMSC1Tet-on-IL-3, in which expression level of IL-3 can be modulated by Dox. The activities of IL-3 were measured under different Dox concentrations. The numbers of hematopoietic progenitors (CFU-GM, CFU-E, CFU-GEMM and LTC-IC) were measured and the capacity of QXMSC1Tet-on-IL-3 sustaining hematopoietic progenitor cell growth was evaluated. The results showed that IL-3 gene transfected stromal cell line QXMSC1-Tet-on + IL-3 expressed high concentration of IL-3 in vitro under control of Dox. The supernatant of QXMSC1-Tet-on + IL-3 was able to increase the number of CFU-GM, CFU-E and CFU-GEMM. The total numbers of nucleated cells and long-term cultured colonies increased in LTC-IC assay. It is concluded that in the culture of QXMSC1-Tet-on + IL-3 cells, Dox actually enhanced IL-3 expression, and thus augmented the proliferation and differentiation of hematopoietic stem/progenitor cells in vitro.

Mesenchymal stem cells (MSCs), precursors of diverse stromal cells, can support hematopoiesis in vitro and can promote the implantation of hematopoietic stem cells in vivo when co-transplanted with CD34(+) cells. The aim of this study was to investigate the potential effect of MSCs on the hematopoietic development of embryonic stem cells (ES cells) and the feasibility of a novel system in which ES cells will be co-cultured with MSCs. The murine bone marrow MSCs were isolated and cultured and then their phenotype and differentiation function were identified with FCM and histochemical technique. The CCE cells, murine ES cell line, were co-cultured with the isolated MSCs and the hematopoietic differentiation of CCE cells was observed with hematopoietic clonogenic assay and RT-PCR. The results showed that the morphology of MSCs became gradually homogeneous with the passage culture of cells. After passage 4, the marker of Sca-1, CD29, CD44 and CD105 were highly expressed, however, CD34 and CD45, the specific marker of hematopoietic and endothelial cells, could hardly be identified. The isolated MSCs differentiated into adipocytes and osteoblasts in specific induction culture system. After maintaining culture on mouse embryonic fibroblasts, CCE cells were plated in suspended culture system with only differentiation inductive agents and co-culture system in which MSCs were added. Compared with CCE cell suspended culture, the cells differentiated into embryoid body were obviously enhanced and there were no colony-forming cells in the co-culture system of ES cells and MSCs. In addition, transcription factor Oct-4 in co-cultured CCE cells was expressed and hematopoietic markers, Flk-1, GATA-1 and beta-H1, were negative. The ability of embryoid bodies derived from the co-culture system to produce hematopoietic colonies was markedly higher than that from the suspended culture system. It is concluded that MSCs inhibit the initial differentiation of ESC and enhance hematopoietic differentiation ability of the co-cultured ES cells.

To establish a stable culture system of mouse embryonic fibroblast(MEF).

To explore the cell components of normal cells and abnormal clons in bone marrow of patients with paroxysmal nocturnal hemoglobinuria (PNH).

To investigate the possible mechanisms of improving ischemic myocardial function by transplantation of bone marrow cells in a rat ischemic heart model.

To investigate the effect of transforming growth factor (TGF) beta 1 gene transfection on the growth of mesenchymal stem cells(MSCs) and to evaluate a new biomimetic biodegradable polymer as scaffolds for applications in articular cartilage tissue engineering.