Preparation and Targeting Evaluation of Recombined Intrakine Plasmid pEGFP/SDF-1/KDE/Folate-Liposome Complexes

Objective:To prepare folate liposome complexes of recombinant plasmid pEGFP/SDF-1/KDEL wich contained intrakine SDF-1/KDEL gene and to observe its targeting for breast cancer cells.Methods:Reverse phase evaporation method was employed for preparing folate-liposome complexeses of pEGFP/SDF-1/KDEL,so that preparation condition was optimized;and fluorometric method was taken for testing encapsulation efficiency.Particle diameter of liposome was tested by transmission electron microscopy.Complexeses encapsulated with 0.05-0.25 mg/ml calcein were got and incubated with breast cancer cell line MDA-MB-231 cells for 2 to 12 h,then dissolved them with dimethyl sulfoxide,then detected absorbance with microplate reader.Results:The optimized encapsulation condition are as follows:molecular ratio of lecithin and cholesterol was 3:1,rotary speed was 150 r/min under temperature of 43℃,and encapsulation efficiency reached 81%in this experiment.Average liposome particle diameter was 210 nm;8 h after incubation, the intake of MDA-MB-231 cells to 0.25 mg/ml compounds achieved saturation. Conclusion:The pEGFP/SDF-1/KDEL folic acid liposome complexes prepared has a high encapsulating rate,liposome particle diameters are homogeneous,which is available for targeting for breast cancer cells in vitro.

Phenotypic Knockout of CXCR4 on Molt-4 with SDF-1α/54 Attached with KDEL

Objective ： To investigate the mechanism of phenotypic knockout of CXCR4 on T-cell leukemia cell line Molt-4 via SDF-1α/54/KDEL intrakine technology, which the mutant SDF-1α/54, human stromal cell-derived Faceor-1 （SDF-1α） was deleted its C- terminal α-helix and attached with a endoplasimc reticulum retention signal 4-peptide- KDEL encoding gene, so that retain the newly synthesized receptor CXCR4 within the Molt-4 cells endoplasmic reticulum. Methods： The recombinant vector pEGFP-C3/SDF- 1α/54/KDEL were transfected into Cos-7 cells by liposome, SDF-1α/54/KDEL fusion protein was confirmed with western blot. The recombinant plasmids were transfected transiently into Molt-4 by electroporation. Results：Western blot confirmed SDF-1α/54/KDEL expression in Cos-7. A dramatic downregulation of CXCR4 expression on Molt-4 was demonstrated by flow cytometric （FCM） analysis. Conelusion：SDF-1α/54/KDEL and SDF- 1αKDEL have no significant deviation for phenotypic knockout of CXCR4. These suggest that the phenotypic knockout effects of SDF-1α/54 against CXCR4 are not influenced by deleting of SDF-1α helix in the C-terminal.

人工智能辅助诊断系统在肺结节CT检测中的应用分析

目的:探讨人工智能辅助诊断系统的应用对于提高在肺结节计算机体层成像(CT)检测准确性的影响。方法:选取2021年4月~2022年7月于本院接受胸部CT检查的309例患者作为研究对象,由影像科医师对CT影像进行审阅,应用人工智能辅助诊断系统进行阅片,结合人工阅片、应用人工智能辅助诊断系统阅片、人工阅片+应用人工智能辅助诊断系统阅片的结果,分析肺结核的检出情况,比较其差异性。结果:病理检查结果显示,在309例患者中,确诊肺结节1236个。人工阅片后,检出肺结节993个,存在漏检247个、误检4个。应用人工智能辅助诊断系统阅片后,检出肺结节1419个,存在漏检2个、误检185个。在肺结节CT检测中,人工阅片的漏检率高于应用人工智能辅助诊断系统阅片(P<0.05)。而人工智能辅助诊断系统阅片的误检率高于人工阅片(P<0.05)。在人工阅片的基础上,应用人工智能辅助诊断系统进行阅片,肺结节检出率为100%。在人工阅片+应用人工智能辅助诊断系统阅片的过程中,阅片时间为(299.73±79.78)s,比人工阅片更短(P<0.05)。应用人工智能辅助诊断系统阅片,直径<5mm、5~10mm、>10mm的肺结节的检出率分别为99.83%、100.00%、100.00%,实性结节、磨玻璃结节、部分实性结节的检出率分别为99.89%、99.66%、100.00%,显著高于人工阅片(P<0.05)。结论:在肺结节的临床诊断中实施胸部CT检查,影像科医师进行人工阅片的同时借助人工智能辅助诊断系统可以有效提高阅片效率,提高肺结节的检出率和准确性,降低误诊、漏诊的风险,便于及时、有效地进行治疗。