[Experimental study of in vitro chondrogenesis by co-culture of bone marrow stromal cells and chondrocytes].

Objective: Chondrogenic microenvironments play a very important role in chondrogenesis of bone marrow stromal cells (BMSC). This study explored the feasibility of in vitro chondrogenesis by co-culture of BMSC and chondrocytes so as to confirm the hypothesis that chondrocytes can provide chondrogenic microenvironment to induce chondrogenic differentiation of BMSC and thus promote in vitro chondrogenesis of BMSC.

Methods: Porcine BMSC and auricular chondrocytes were in vitro expanded respectively and then were mixed at a ratio of 8:2 (BMSC:chondrocyte).

[Reconstruction of rabbit corneal stroma using tissue engineering technique].

Objective: Reconstruct corneal stroma by tissue engineering.

Methods: Primary corneal stromal cells were isolated from newborn rabbit cornea. When the cultured cells reaching confluence, the stromal cells were mixed with polyglycolic acid (PGA) to form a cell-scaffold construct.

[Changes in tissue plasminogen activator and plasminogen activator inhibitor during administration of nitroglycerine into internal thoracic artery in dogs with acute myocardial ischemia].

Objective: To study the changes in tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI) in a model of acute myocardial infarction reproduced in the dog with administration of nitroglycerin into internal thoracic artery under pressure.

Methods: Sixty healthy cross-breed dogs were randomly divided into experimental and control group with 30 dogs in each group. The animal model of acute myocardial ischemia was reproduced by ligating the left anterior descending coronary artery.

[Isolation and culture of human pluripotent embryonic germ cells].

To establish human pluripotent embryonic germ (EG) cell lines, human primordial germ cells (PGCs) of embryos aborted in 5-9 week were cultured on inactive mouse STO fibroblast feeder. The medium contained human leukemia inhibitory factor (hLIF), human basic fibroblast growth factor (hbFGF) and forskolin. The EG cells could be passaged continuously until 12 generations.

[Repairing porcine knee joint osteochondral defects at non-weight bearing area by autologous BMSC].

Objective: To test the possibility of using bone marrow stromal cells (BMSC) and biodegradable polymers to repair articular osteochondral defects at non-weight bearing area of porcine knee joints.

Methods: Bone marrows were harvested from 18 hybrid pigs. BMSC were cultured and in vitro expanded and induced with dexamethasone (group A) or with dexamethasone and transforming growth factor-beta1 (TGF-beta1) (group B) respectively.

[In-vivo tracing of bone marrow stromal cell differentiating into chondrocytes by green fluorescent protein gene transfection].

Aim: To achieve highly efficient, stable and long-term expression of green fluorescent protein(GFP) reporter gene in bone marrow stromal cells(BMSCs) and to trace directly the distribution and differentiation of BMSCs in articular cartilage defects.

Methods: Recombinant RV-GFP expression vector was constructed and transfected into packaging cell PT67. After G418 screening and amplification, cell clones producing high level recombinant viruses were obtained and in-vitro expanded.

[Preliminary Study on the Effects of Novel Retinoids SX-115 and CHU-012 on NB4 Cell Line].

In this research, the effects of two new retinoids, SX-115 and CHU-012, on promyelocytic leukemia cell line NB4 were studied in vitro. Cell proliferation, cell morphologic characters, cell cycle kinetics, reduction ability of NBT, differentiation antigens, immunofluorescence staining and RT-PCR were adopted as the observational parameters. The results showed that SX-115 and CHU-012 induced differentiation of NB4 cells at concentration of 10(-6) mol/L.