AIM: To investigate the cytological basis and differentiating conditions of human bone marrow mesenchymal stem cells (hMSCs) differentiated into cells of the endothelial lineage in vitro. METHODS: hMSCs were isolated by density gradient centrifugation and fractionated on a 1 073 g/L Percoll. The combination of VEGF165 and various matrix proteins including fibronectin (FN) and type I collagen (Col) was used to induce hMSCs in vitro. Cells were characterized by immunohistochemistry, cytochemistry, FACS and ultrastructure to identify and detect the differentiated population and markers. RESULTS: hMSCs was positive for KDR. PAS reaction was positive and ultrastructure of hMSCs showed glycogen- pool in ectoplasm. Glycogen reducing or disappear suggested that stem cells have occurred differentiation. Induction of hMSCs resulted in the increase of KDR, β1 integrin and CD34. CONCLUSION: hMSCs were induced to a transit population (TP( )) that differentiated toward the endothelial progenitor cells ( EPC), but not a really EPC. hMSCs pedigree diagram of differentiation was hMSCs→TP→EPC→endothelial cells (Ecs).

AIM:To investigate the cytological basis and differentiating conditions of human bone marrowmes-enchymal stem cells(hMSCs) differentiated into cells of the endothelial lineagein vitro.METHODS:hMSCs were isolatedby density gradient centrifugation and fractionated on a 1 073 g/L Percoll.The combination of VEGF165and various matrixproteins including fibronectin(FN) and typeⅠ collagen(Col) was used to induce hMSCsin vitro.Cells were character-ized by immunohistochemistry,cytochemistry,FACS and ultrastructure to identify and detect the differentiated populationand markers.RESULTS:hMSCs was positive for KDR.PAS reaction was positive and ultrastructure of hMSCs showedglycogen-pool in ectoplasm.Glycogen reducing or disappear suggested that stem cells have occurred differentiation.In-duction of hMSCs resulted in the increase of KDR,?1integrin and CD34.CONCLUSION:hMSCs were induced to atransit population(TP) that differentiated toward the endothelial progenitor cells(EPC),but not a really EPC.hMSCspedigree diagram of differentiation was hMSCs→TP→EPC→endothelial cells(ECs).

Objective: To prepare peptide minotope-based recombinant diagnostic antigen of Epstein-Barr virus (EBV) infection and evaluate its antigenicity preliminarily. Methods: With Trx at the N-terminal and His tag at the C-terminal, the peptide minotope of EBV (GP125, F1, A2, A3C2) was expressed in Escherichia coli and purified by affinity and anion exchange chromatography (designated 'H58’); based on antigenicity of H58 identified by Western blotting (WB), we constructed and evaluated a novel early diagnostic ELISA for EBV infection. Results: The soluble H58 protein with high concentration (2.8 mg/ml) and purity (99.01) was obtained; WB analysis found that there was an obvious band (28 ×10³) on the NC membrane, using H58 anti-Trx monoclonal antibody or acute-phase sera of EBV infection as the first antibody. With the novel ELISA, 50 positive sera of EBV infection and 50 negative sera were detected, displaying that the grouping of OD value of positive serum (95%CI: 1.233-1.489) and negative serum (95%CI: 0.113-0.159) was different (P<0.05) with the sensitivity 98.0%, specificity 96.0% and kappa value 0.940. Conclusions By E. coli expression and affinity and ion exchange chromatography purification, the peptide minotope-based recombinant diagnostic antigen of EBV infection was obtained with excellent antigenicity, which could be applied for serological detection of EBV infection.