ABSTRACT
Objective To evaluate the predictive value of N-terminal-pro-brain natriuretic peptide (NT-proBNP) in weaning patients from mechanical ventilation (MV).Methods Data of 42 patients supported with MV in intensive care unit (ICU) admitted to the Rui Jin Hospital from January through December in 2014 were retrospectively analyzed,and the causes for MV were recorded.According to the outcomes of weaning from MV after 48 hours,the patients were divided into two groups namely success group and failure group.Comparisons of fluid balance in 72 hours before spontaneous breathing trial (SBT),and comparisons of NT-proBNP1 levels at admission,NT-proBNP2 levels before SBT,NT-proBNP3 levels after 48 hours after SBT between two groups were carried out.And the receiver operating characteristic (ROC) curve for predicting weaning rate was plotted to find the optimal cut-off point of NT-proBNP2.Results In the total of 42 patients,there were 27 cases in success group and 15 cases in failure group.There were not statistically differences of NT-proBNP1 levels between success group and failure group (P =0.121).However,the NT-proBNP2 levels and NT-proBNP3 levels in failure group were significantly higher than those in success group (P =0.01,0.003).The area under curve (AUC) of the ROC curve of NT-proBNP2 levels to predict the failure of weaning was 0.862 (95％ CI:0.753-0.971).When the optimal cut-off point of NT-proBNP2 was 715.5 pg/mL,the sensitivity and specificity were 93.3％ and 74.1％,respectively.Conclusion The NT-proBNP2 levels before SBT have predictive value in weaning rate,and it can be used as one of the screening indicators for weaning.
ABSTRACT
BACKGROUND: Bone marrow mesenchymal stem cells are important seeded cells for construction of tissue-engineered trachea, but there is no special surface marker. Therefore, identification of bone marrow mesenchymal stem cells is mostly based on morphology, phenotype antigen and the function of differentiation. OBJECTIVE: To explore the feasibility of the tracheal chondrogenic differentiation of bone marrow mesenchymal stem cells under a special condition through isolation, cultivation and identification of bone marrow mesenchymal stem cells. METHODS: Rabbit bone marrow was acquired in the sterile environment to isolate and culture bone marrow mesenchymal stem cells to passage 2 by bone marrow adherence and screening method. Flow cytometry identified the phenotype CD44, CD45 of bone marrow mesenchymal stem cells at passages 1 and 2. Rabbit tracheal samples were acquired in the sterile environment, the tracheal chondrocytes were isolated and cultured by enzyme digestion, and toluidine blue staining was used to detect aggrecan. Bone marrow mesenchymal stem cells were co-cultured with tracheal chondrocytes by Transwel and transforming growth factor β1. Cel morphology was detected under an inverted microscope. Real-time quantitative PCR and toluidine blue staining detected the extracel ular matrix components, such as type Ⅱ col agen and aggrecan.RESULTS AND CONCLUSION: After isolation and culture, cells were spindle and irregular in morphology, and passaged cells thrived that were gathered into a fish-like colony growth. For passage 1 bone marrow mesenchymal stem cells, the positive rates of phenotype antigen CD44 and CD45 were respectively 96.97% and 13.72%; for passage 2 cells, the positive rates of phenotype antigen CD44 and CD45 were 99.11% and 8.54%, respectively. Tracheal chondrocytes were positive for toluidine blue staining. The morphology of induced bone marrow mesenchymal stem cells changed from long fusiform to triangular or irregular shape, indicating the chondrocytes expressed type Ⅱ col agen and aggrecan, and toluidine blue staining was positive. These results showed bone marrow adherence and screening method could acquire bone marrow mesenchymal stem cells, and the purity of passage 2 cells is higher. Under a special condition, bone marrow mesenchymal stem cells have the potential of chondrogenic differentiation, and can be selected as seed cells for construction of tissue-engineered trachea.