ABSTRACT
In vitro proliferation of hematopoietic stem cells(HSCs) is performed on the basis ofthe simulation of in vitro blood system by adding growth factors and promoting components. Several protocols for expansion of HSCs in vitro are currently in development. In recent years, with the understanding of the molecular and cellular mechanisms regulating HSCs maintenance and expansion, tremendous progress has been made in this field. In this paper, research progress in the study of the factors determining the in vitro HSCs proliferation is reviewed.
ABSTRACT
Objective:To investigate Bcl-2 and Bax gene expression in acute myelogenous Leukemia and the relationship between Bcl-2/Bax ratio and drug resistance.Method:Expression of Bcl-2、Bax was detected by immunohistochemical method while drug resistance of AML was detected by cell culture and MTT assay.Results:A high expression of Bcl-2 and a low expression of Bax were detected in AML,respectively,and the ratio between Bcl-2 and Bax was significantly higher than that in normal control (P＜0.01). The ratio in those who are resistant to chemotherapy was significantly higher than that in those sensitive to chemotherapy (P＜0.05).The responsiveness to chemotherapy of those with a high ratio was poorer than thos with a low ratio (P＜0.05).Conclusion:The alteration of Bcl-2 and Bax played certain role in the development of drug resistance in AML,the test of Bcl-2/Bax ratio may have great significance in choice of chemotherapeutic agents and also provide important information for outcome prediction.
ABSTRACT
AIM: To study the survival, transfer and distribution of bone marrow CD34+/CD45+ cells from transgenic GFP mouse after transplanted into the completed transversional spinal cord rat model. METHODS: The bone marrow cells isolated from transgenic GFP mice were cultured in vitro. The cultured cells were identified by anti-CD34 and anti-CD45 monoclonal antibodies, and were transferred into the end of transection spinal cord. Paraformaldehyde was infused into the left ventricle of the rat model at the 24 h, 48 h, 1 week, 2 weeks, 4 weeks and 8 weeks after cell transplantation. Through sank and frozen, the spinal cord was sectioned at 10 ?m thickness. The green fluorescence positive cells were observed under the fluorescence microscope. CD34+/CD45+ cells were identified by immunohistochemistry staining. RESULTS: Green fluorescence positive cells were found at the head and the end of the completed transection part of spinal cord. Most of the green fluorescence positive cells were distributed in the gray substance of spinal cord. CD34+/CD45+ cells were found by immunohistochemistry staining. CONCLUSION: CD34+/CD45+ cells survived in spinal cord of SD rat, and migrated to the head of the transection part. The distance of migration was extended by the time.