To construct a recombinant plasmid Pet23a-M, the gene encoding severe acute respiratory syndrome (SARS) coronavirus membrane protein was amplified by RT-PCR and cloned into the expression plasmid Pet23a. Results of restriction endonuclease analysis, PCR detection and DNA sequencing analysis revealed that the cloned DNA sequence was the same as that reported. The recombinants were transformed into Escherichia coli (E. Coli) BL21 (DE3) and induced by Isopropyl-beta-D-thiogalactopyranoside (IPTG). The expression of 27 kD (1 kD=0.992 1 ku) protein was detected by SDS-PAGE and pured by metal chelated chromatography. Results of Western-blot showed that this expressed protein could react with antibodies in sera of SARS patients during convalescence. This provided the basis for the further study on SARS virus vaccine and diagnostic agents.
Cloning, Molecular ; Escherichia coli/genetics ; Escherichia coli/metabolism ; Membrane Proteins/*biosynthesis ; Membrane Proteins/genetics ; Membrane Proteins/isolation & purification ; Plasmids/biosynthesis ; Plasmids/genetics ; Recombinant Proteins/biosynthesis ; Recombinant Proteins/genetics ; Recombinant Proteins/isolation & purification ; Reverse Transcriptase Polymerase Chain Reaction ; SARS Virus/chemistry ; SARS Virus/*genetics ; Viral Vaccines/biosynthesis

Objective To construct a prokaryotic expression system containing the dense granule protein 4(GRA4) of Toxoplasma gondii,purify the expressed protein and detect its immunogenicity.Methods The specific fragment of GRA4 gene was amplified by PCR.After subcloning the prokaryotic expression recombinant pET,GRA4,the expressed product was purified with His?BindTM affinity chromatography and analyzed by Western blot.BALB/c mice were immunized with the GRA4 recombinant protein,and the antibody IgG titer was detected by ELISA.Results The pET,GRA4 prokaryotic expression system was obtained.The MW of the expressed protein was Mr 40 000 and formed in inclusion body.After purification,the recombinant protein could be specifically recognized by the T.gondii infected rabbit serum.Mice immunized with the purified recombinant protein elicited high titer of IgG antibody.Conclusion The pET,GRA4 recombinant protein was successfully expressed and purified,which shows the immunogenicity.

To construct a recombinant plasmid Pet23a-M, the gene encoding severe acute respiratory syndrome (SARS) coronavirus membrane protein was amplified by RT-PCR and cloned into the expression plasmid Pet23a. Results of restriction endonuclease analysis, PCR detection and DNA sequencing analysis revealed that the cloned DNA sequence was the same as that reported. The recombinants were transformed into Escherichia coli (E. Coli) BL21 (DE3) and induced by Isopropyl-beta-D-thiogalactopyranoside (IPTG). The expression of 27 kD (1 kD=0.992 1 ku) protein was detected by SDS-PAGE and pured by metal chelated chromatography. Results of Western-blot showed that this expressed protein could react with antibodies in sera of SARS patients during convalescence. This provided the basis for the further study on SARS virus vaccine and diagnostic agents.
Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Humans ; Membrane Proteins ; biosynthesis ; genetics ; isolation & purification ; Plasmids ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; isolation & purification ; Reverse Transcriptase Polymerase Chain Reaction ; SARS Virus ; chemistry ; genetics ; Viral Vaccines ; biosynthesis

BACKGROUND:Reducing the rate of abnormal fertilization is an effective approach to improving the efficacy of in vitro fertilization and reducing patients'financial strain.However,the current research on abnormal fertilization has focused on exploring the types of prokaryotic nuclei and their generation mechanisms,as well as analyzing embryos formed by abnormal fertilization,chromosomal ploidy and utilization value.There is a lack of clinical prediction models for abnormal fertilization based on retrospective studies. OBJECTIVE:To construct a nomogram model to predict abnormal female factors in in vitro fertilization. METHODS:A total of 5 075 patients undergoing treatment for conventional in vitro fertilization at Nanxishan Hospital of Guangxi Zhuang Autonomous Region from March 2017 to March 2022 were retrospectively analyzed.The male confounders were calibrated on a 1:1 propensity score with a match tolerance of 0.02,and 1 672 cases were successfully matched.According to the Vienna Consensus,patients with≥60%normal fertilization capacity were included in the normal fertilization group(n=836)and those with<60%normal fertilization capacity were included in the abnormal fertilization group(n=836).The model and validation groups were obtained by random sampling at a ratio of 7:3.Factors related to the occurrence of abnormal fertilization following conventional in vitro fertilization in the model group were screened using univariate analysis and the best matching factors were selected using the Least Absolute Shrinkage and Selection Operator(LASSO)and included in a multifactorial forward stepwise Logistic regression to identify their independent influencing factors and plot a nomogram.Finally,the prediction model was validated for discrimination,accuracy and clinical application efficacy using receiver operating characteristic curves,calibration curves,clinical decision curves and clinical impact curves. RESULTS AND CONCLUSION:The univariate analysis indicated the factors influencing the occurrence of abnormal fertilization were age,controlled ovarian hyperstimulation protocol,number of assisted pregnancies,years of infertility,infertility factors,anti-mullerian hormone,sinus follicle count,basal luteinizing hormone,luteinizing hormone concentration on the human chorionic gonadotropin day,and estradiol level on human chorionic gonadotropin injection day(P<0.05).LASSO regression further identified the best matching factors,including age,microstimulation protocol,number of assisted pregnancies,years of infertility,anti-mullerian hormone,luteinizing hormone level on human chorionic gonadotropin injection day,and estradiol level on human chorionic gonadotropin injection day(P<0.05).Multifactorial forward stepwise Logistic regression results showed that age,microstimulation protocol,number of assisted conceptions,years of infertility,anti-mullerian hormone,and estradiol level on human chorionic gonadotropin injection day were independent influencing factors for the occurrence of abnormal fertilization following conventional in vitro fertilization.The receiver operating characteristic curves showed an area under the curve of 0.761(0.746,0.777)for the model group and 0.767(0.733,0.801)for the validation group,indicating that the model has good discrimination.The mean absolute error of the calibration curve was 0.044,and the Hosmer-Lemeshow test indicated that there was no significant difference between the predicted probability of abnormal fertilization and the actual probability of abnormal fertilization(P>0.05),indicating the prediction model has good consistency and accuracy.The clinical decision curves and clinical impact curves showed that the model and validation groups had the maximum net clinical benefit at valve probability values of 0.00-0.52 and 0.00-0.48,respectively,and there was a good clinical application efficacy in this valve probability range.To conclude,the nomogram model has good discrimination and accuracy as well as clinical application efficacy for predicting the occurrence of abnormal fertilization in women undergoing conventional in vitro fertilization based on age,microstimulation protocol,number of assisted conceptions,years of infertility,anti-mullerian hormone,and estradiol level on human chorionic gonadotropin injection day.