Objective To explore the label ing efficiency and cellular viabil ity of rabbit BMSCs labeled with different concentrations of superparamagnetic iron oxide (SPIO) particles, and to determine the feasibil ity of magnetically labeled stem cells with MR imaging. Methods The BMSCs were collected from il iac marrow of 10 adult rabbits (weighing 2.5-3.0 kg) and cultured. The SPIO-poly-L-lysine compound by different ratios mixed with medium, therefore, the final concentration of Fe2+ was 150 (group A), 100 (group B), 50 (group C) and 25 μg (group D) per mL, respectively, the 3rd generation BMSCs culture edium was added to lable; non-labeled cells served as a control (group E). MR imaging of cell suspensions was performed by using T1WI and T2WI sequences at a cl inical 1.5 T MRI system. Results BMSCs were efficiently labeled with SPIO, labeled SPIO particles were stained in all cytoplasms of groups A, B, C and D. With the increasing of Fe2+ concentration, blue dye particles increased. The staining result was negative in group E. The cell viabil ity in groups A, B, C, D and E was 69.20% ± 6.11%, 80.41% ± 2.42%, 94.32% ± 0.67%, 96.24% ± 0.34% and 97.43% ± 0.33%, respectively. There were statistically significant differences between groups A, B and groups C, D and E (P lt; 0.05), and between group A and group B (P lt; 0.05). T1WI images had no specific difference among 5 groups, T2WI images decreased significantly in groups A, B, C, decreased sl ightly in group D, and had l ittle change in group E. The T2WI signal intensities of groups A, B, C, D and E were 23.37 ± 6.21, 26.73 ± 3.60, 29.63 ± 2.82, 45.03 ± 6.76 and 783.15 ± 7.38, respectively, showing significant difference between groups A, B, C, D and group E (P lt; 0.05), and between groups A, B, C and group D (Plt; 0.05). Conclusion BMSCs can be easily and efficiently labeled by SPIO without interference on the cell viabil ity in labled concentration of 20-50 μg Fe2+ per mL. MRI visual ization of SPIO labeled BMSCs is feasible, which may be critical for future experimental studies.
Objective To evaluate associations betweenMTHFD1 gene G1958A polymorphism and the risk of neural tube defects (NTDs). Methods We electronically searched databases including PubMed, The Cochrane Library, Web of Science, CNKI, VIP, and WanFang Data from inception to June 2016 to collect case-control studies of the correlation between the G1958A polymorphism inMTHFD1 and the risk of NTDs. Two reviewers independently screened the studies, extracted data and assessed the risk of bias of included studies, and then, meta-analysis was performed using Stata 12.0 software. Results Thirteen case-control studies were included, involving 1 724 NTDs infants, 1 485 mothers and 774 fathers with NTDs offspring. The results of meta-analysis showed that there was significant association betweenMTHFD1 gene G1958A polymorphism and increased risk of NTDs in infants (AAvs. GG: OR=1.437, 95%CI 1.100 to 1.878,P=0.008; AA+AGvs. GG: OR=1.187, 95%CI 1.031 to 1.367,P=0.017; Avs. G: OR=1.210, 95%CI 1.050 to 1.394,P=0.008). However, there was no association between biparentalMTHFD1 gene G1958A polymorphism and NTDs in the offspring. Conclusion The current evidence shows thatMTHFD1 gene G1958A polymorphism may be a genetic risk factor for NTDs. Due to the limited quantity and quality of the included studies, more high quality studies are needed to verify the above conclusion.