Objective To prepare a variety of quality control(QC)materials for SARS-CoV-2 variants as an addition to the conven-tional SARS-CoV-2 nucleic acid QC products for the laboratory detection of mutant strains by optimizing the preparation and purification process of MS2 phage virus-like particle(VLP)technique,and evaluate their performances.Methods The typical mutation sequence fragments or full length S genes were designed and synthesized according to the genomic information of SARS-CoV-2 variants.Then,they were inserted into the downstream of maturase gene,coat protein and the pac-site of MS2 phage to construct a series of recombi-nant expression vectors.After induced by the prokaryotic expression system,the VLP products were purified through the polyethylenei-mine precipitation,ultrafiltration,nuclease digestion,and gel filtration chromatography.The obtained VLP were validated by the nucle-ic acid electrophoresis,protein electrophoresis,protein concentration determination,and fluorescence PCR,and their performances such as nucleic acid residue and stability were also evaluated.Results A total of 10 kinds of VLP containing the targeted sequences of the gene to be tested were prepared.The length of the foreign sequence wrapped in them ranged from 297 bp to 3 822 bp,which could be combined into a variety of QC materials for the mutation detection of different SARS-CoV-2 variants.The prepared VLP QC materials could not be effectively amplified without nucleic acid extraction or reverse transcription steps during the routine nucleic acid detection.The simulated QC samples remained stable after repeated freeze-thaw cycles.They could be stored stably for 2 months at 25 ℃ and 4 weeks at 37 ℃.Conclusion The established preparation and combined purification process of VLP QC materials can encapsulate vari-ous exogenous nucleic acid sequences with different lengths into the viral coat protein to form VLP,with high production efficiency.The VLP QC products prepared by the above process have stable performance and almost no residual exogenous nucleic acid,which can ef-fectively meet clinical requirements and ensure the quality of laboratory testing.

Objective To prepare a variety of quality control(QC)materials for SARS-CoV-2 variants as an addition to the conven-tional SARS-CoV-2 nucleic acid QC products for the laboratory detection of mutant strains by optimizing the preparation and purification process of MS2 phage virus-like particle(VLP)technique,and evaluate their performances.Methods The typical mutation sequence fragments or full length S genes were designed and synthesized according to the genomic information of SARS-CoV-2 variants.Then,they were inserted into the downstream of maturase gene,coat protein and the pac-site of MS2 phage to construct a series of recombi-nant expression vectors.After induced by the prokaryotic expression system,the VLP products were purified through the polyethylenei-mine precipitation,ultrafiltration,nuclease digestion,and gel filtration chromatography.The obtained VLP were validated by the nucle-ic acid electrophoresis,protein electrophoresis,protein concentration determination,and fluorescence PCR,and their performances such as nucleic acid residue and stability were also evaluated.Results A total of 10 kinds of VLP containing the targeted sequences of the gene to be tested were prepared.The length of the foreign sequence wrapped in them ranged from 297 bp to 3 822 bp,which could be combined into a variety of QC materials for the mutation detection of different SARS-CoV-2 variants.The prepared VLP QC materials could not be effectively amplified without nucleic acid extraction or reverse transcription steps during the routine nucleic acid detection.The simulated QC samples remained stable after repeated freeze-thaw cycles.They could be stored stably for 2 months at 25 ℃ and 4 weeks at 37 ℃.Conclusion The established preparation and combined purification process of VLP QC materials can encapsulate vari-ous exogenous nucleic acid sequences with different lengths into the viral coat protein to form VLP,with high production efficiency.The VLP QC products prepared by the above process have stable performance and almost no residual exogenous nucleic acid,which can ef-fectively meet clinical requirements and ensure the quality of laboratory testing.

Objective The objective of this study was to investigate the clinicopathological features and rational treatment of primary fallopian tube cancer(PFTC).Methods The clinical and pathological data of 39 patients with primary fallopian tube cancer from January 2006 to July 2016 in Beijing Tongren Hospital of Capital University were retrospectively analyzed.Results There were 39 cases of undifferentiated carcinoma,including 1 case of undifferentiated and transitional cell carcinoma,37 cases of undifferentiated adenocarcinoma,or 29 cases of simple adenocarcinoma and 10 cases of mixed type.Among them,7 cases were treated with clear cell carcinoma,endometriosis in 2 cases,combined with transitional cell carcinoma in 1 case.Extra-pelvic metastases were the most common site of the omentum with 17 cases.The preoperative test CA125 was increased in 13 cases and 38 patients received postoperative chemotherapy.The 5-year overall survival rate of 39 patients was 51.3%.Univariate analysis showed that postoperative pathologic stage(Ⅰ~Ⅱ vs.Ⅲ,P<0.001),intraoperative residual lesion size(P<0.001),omentum metastasis(P<0.001),ovarian metastasis(P=0.034),retroperitoneal lymph node metastasis(P=0.018)and preoperative CA125 elevation(P=0.002)were associated with prognosis,while age(P=0.310)and pathological grade(P=0.663)were not associated with prognosis.Multivariate analysis showed that the number of patients with postoperative lymph node metastasis(P=0.018)and preoperative CA125 elevation(P=0.002)were correlated with prognosis(HR=1.202,95% CI:2.354~63.290,P=0.003) and pathological stage(HR=3.810,95% CI:1.202~12.079,P=0.023).They were associated with prognosis as independent prognostic factors.Conclusion Tumor pathologic staging and omentum metastasis are important prognostic factors influencing the prognosis of patients with primary fallopian tube cancer.Early diagnosis and complete operation can improve the prognosis of patients.