Objective To establish a simple and efficient method to isolate and culture the umbilical vein vascular endothelial cells in canine. Methods Twelve umbilical cords [(13.0 ± 1.5) cm in length] were taken from 12 newborn pups of Beagles. And then the vascular endothelial cells were isolated from these umbilical cords digested by 1% collagenase type I for 5, 7, and 10 minutes respectively (4 umbilical cords in each group). After cultured, the vascular endothelial cells were identified by morphology, immunofluorescence, and flow cytometry. And the growth curvature of umbilical vein vascular endothelial cells was detected by MTT assay. Results Few vascular endothelial cells were collected at 5 and 10 minutes after digestion; many vascular endothelial cells were seen at 7 minutes, and became cobblestone with culture time, with a large nucleus; after passage, cell morphology had no obvious change. Fluorescence microscope results showed that positive von Willebrand factor (vWF) and CD31 cells were observed in most of cells. The flow cytometry test displayed that the positive cell rates of vWF and CD31 were 99.0% ± 0.7% and 98.0% ± 1.2%, respectively. The above results indicated that cultured cells were vascular endothelial cells. MTT assay showed that vascular endothelial cells proliferation increased significantly with culture time. Conclusion Enzyme digestion is a convenient method to isolate vascular endothelial cells from canine umbilical vein, and a large number of cells and high purity of cells can be obtained by the method.
ObjectiveTo evaluate the diagnostic accuracy and efficacy of X-ray for evaluating the tip position of umbilical venous catheterization (UVC). MethodsThe PubMed, Embase, Cochrane Library, CBM, CNKI, VIP and WanFang Data databases were electronically searched to collect diagnostic tests for UVC tip localisation from inception to 1 May 2023. Two reviewers independently screened the literature according to the inclusion and exclusion criteria, extracted the data and assessed the quality of the studies using the QUADAS-2 tool. Then, meta-analysis was performed by using Stata 16.0 software. Results Twelve articles involving 1 055 patients were included. The sensitivity and specificity of Negar Yazdani’s study were both 100%. The results of the meta-analysis (the remaining eleven articles, n=951) indicated a pooled sensitivity of 0.7 (95%CI 0.6 to 0.8), a pooled specificity of 0.8 (95%CI 0.7 to 0.9), a positive likelihood ratio of 4.0 (95%CI 2.0 to 8.1), a negative likelihood ratio of 0.4 (95%CI 0.2 to 0.6) and a diagnostic odds ratio of 11 (95%CI 3 to 36) with an area under the cumulative receiver operating characteristic curve of 0.8 (95%CI 0.8 to 0.9). A subgroup analysis was performed according to the different methods of judging X, the 8th–9th thoracic, the 9th–10th thoracic and combined judgement of the diaphragmatic plane + the vertebral body + the heart shadow. The sensitivities of the 3 groups were 0.8 (95%CI 0.5 to 0.9), 0.5 (95%CI 0.4 to 0.7) and 0.8 (95%CI 0.6 to 0.9); the specificities of the 3 groups were 0.8 (95%CI 0.6 to 0.9), 0.76 (95%CI 0.6 to 0.9) and 0.91 (95%CI 0.79 to 0.96). The areas under the cumulative receiver operating characteristic curve were 0.9 (95%CI 0.8 to 0.9), 0.7 (95%CI 0.6 to 0.7) and 0.92 (95%CI 0.89 to 0.94). ConclusionSome error is present when determining the catheter tip position by X-ray, in which the evaluation of the umbilical vein catheter tip position through a comprehensive evaluation of the diaphragmatic plane, the heart margin and the vertebral body is more powerful than the evaluation of the vertebral body alone.