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Objective To explore the best multiplicities of infection (MOI),the expression of the target gene and in vitro MR imaging of adenovirus vector-mediated transferrin receptor (TFRC) reporter gene transfection of human colorectal cancer Lovo cells.Methods Lovo cells were transfected with recombinant adenovirus (Ad-TFRC) at 5,10,50,100 MOI to determine the best MOI,and quantitative real-time PCR was performed to detect the eDNA of TFRC.The transfected cells were incubated in the culture medium including Tf-USPIO of various concentrations,and were observed by Prussian blue staining,then the cell viability was evaluated via Trypan blue staining.The labeled cells were scanned with 7.0T MR T2W,T2 map,T2* map sequences,and the signal intensities were analyzed.Results Ad-TFRC were successfully transfected into Lovo cells.The best MOI was 50,and the efficiency of infection was more than 90％.The relative expression amount of TFRC in transfected cells was higher than that in control Lovo cells by real-time quantitive PCR (P＜ 0.01).Prussian blue staining showed numerous blue iron particles in transfected cells when the best labeling concentration was 1.5 μg/ml.Trypan blue staining results of transfected Lovo cells and control Lovo cells was (93.80± 1.60)％ and (95.10±2.30) ％,respectively (P＞0.05).MR imaging in vitro showed that compared with control Lovo cells,the signal intensity decreased on T2WI,T2 map and T2* map sequences in transfected Lovo cells (P＜0.05).Conclusion TFRC reporter gene can be efficiently mediated by adenovirus for expression in Lovo cells.After magnetization labeling,7.0T MR imaging of Lovo cells can be successfully achieved in vitro.
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Objective To study the application value of MSCT in preoperative evaluation of rectal cancer before surgery.Methods Clinical materials of 146 patients with colonoscopy and clinical proved rectal cancer were recruited.MSCT were performed with plain and triphasic dynamic contrast enhancement before surgery.The value of MSCT was evaluated by comparing the results of pre-operative evaluation with the surgical results.Results 130 cases accepted surgical treatment:3 cases of transanal local excision,28 cases of Miles operation,3 cases of Hartmann operation,96 cases of Dixon.Preoperative evaluation of MSCT:33 cases of Miles,4 cases of Hartmann,88 cases of Dixon,5 cases of local excision of the anus.The accuracy on MSCT preoperative evaluation was 84.62%. MSCT preoperative evaluation consistency was consistent with postoperative outcome(k=0.653,χ2=225.352,P=0.000).Conclu-sion It is high accuracy for MSCT in preoperative evaluation of rectal cancer,and it can provide important significance for preopera-tive selection of surgical procedures.