ObjectiveTo explore a new method of developing a pre-vascularized cell sheets. MethodsBone marrow mesenchymal stem cells (BMSCs) from 3-week-old Japanese white rabbits were harvested and cultured. Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) were added into the culture medium to differentiate into endothelial like cells (ECs) from BMSCs (experimental group), and non-induced cells served as the control group. The cell morphology was observed; and the von Willebrand factor (vWF) and CD31 immunofluorescent staining was used to identify the induced BMSCs. The 2nd generation BMSCs were seeded on a cell culture dish at a cell density of 9×104cells/cm2 and cultured for 14 days to form a thick cell sheet, and ECs from BMSCs were then seeded on the BMSCs sheet at a cell density of 5×104 cells/cm2 to develop pre-vascularized cell sheets and cultured for 3, 7, and 14 days (group A); non-induced BMSCs sheet and only ECs from BMSCs were used as group B and group C, respectively. The CD31 immunofluorescent staining and histological analysis were performed to evaluate the pre-vascularized cell sheet. ResultsBMSCs changed from long fusiform to cobblestone-like morphology after induced by VEGF and bFGF. The expressions of CD31 and vWF were positive in experimental group, but were negative in control group, which suggested that BMSCs have the ability to differentiate into ECs under this condition. After the ECs were seeded on the BMSCs sheet, the ECs migrated and rearranged; intracellular vacuoles and networks were observed. Furthermore, immunofluorescent staining for CD31 also revealed a developing process of tube formation after the ECs were seeded on the BMSCs sheet. The histological evaluations indicated the microvessel lumen formed. However, no similar change was observed in groups B and C. ConclusionBMSCs have the ability to differentiate into ECs after induced by VEGF and bFGF. ECs from BMSCs can develop into vascular network constructs when seeded on the BMSCs sheet, which provides a new method for engineering pre-vascularized tissue construction.
ObjectiveTo explore the risk factors for central venous catheter (CVC)-related infections and its Countermeasures, as CVC is an important vascular access for blood purification and is widely used in clinical applications, but catheter-related infection is one of the common severe complications. MethodsWe retrospectively analyzed the clinical data of 725 patients with complicated infections of indwelling center venous double lumen catheter treated between January 2009 and December 2012. ResultsAmong all 725 cases, 15 had catheter-related infection. There were one case of subcutaneous tunnel infection (staphylococcus aureus by the secretion culture, negative for blood culture), and 14 cases of positive blood culture including 9 staphylococcus aureus cases, 3 escherichia coli cases, 1 colorless bacillus case and 1 stenotrophomonas maltophilia case. Eight cases were cured by antibiotic therapy while antibiotics were invalid in the other 7 cases resulting in tube withdrawing. ConclusionThe central venous catheter-related infections are related to medical service ability, catheter indwelling position, indwelling time, hemodialysis adequacy, patients' general condition and personal hygiene. Taking relative measures in view of each factor is the key to prevent infections.