African swine fever(ASF)caused by African swine fever virus(ASFV)is a febrile,hem-orrhage and highly fatal infectious disease in pigs,which poses a serious threat to the global pig in-dustry.Currently,no vaccine is available for the prevention and control of ASF,and several ASF vaccines,including gene deletion attenuated live vaccines,live vector vaccines,and subunit vaccines are under the development stage in the laboratory research.As one of the most promising vaccines,live vector vaccine has the characteristic of safety and simulation of the pathogen natural infection to effectively stimulate the innate and adaptive immune responses,which becomes one of the hotspots in the research and development of novel ASF vaccines.This review focuses on the pro-gress in using modified viruses as vectors for ASF live vector vaccines,and aims to provide valua-ble information for future development of safe and effective ASF vector vaccines.

African swine fever(ASF)is an acute,febrile,and highly fatal disease caused by African swine fever virus(ASFV)in pigs.Given the current lack of commercial vaccines and the continu-ous evolution of ASFV in recent years,the emergence of moderately virulent genotype Ⅱ strains and the introduction of genotype Ⅰ attenuated strains have led to persistent and chronic infections in pigs.Therefore,the detection of specific antibodies against ASFV has become imperative.In this study,we established a competitive chemiluminescence immunoassay(p30-cCLIA)for detecting ASFV p30 antibodies using p30 monoclonal antibodies.By detecting sera with clear negative and positive backgrounds,we determined that the Cut-off value of this method was 50％,with both di-agnostic sensitivity(Dsn)and diagnostic specificity(Dsp)reaching 100％.Under optimal reaction conditions,we screened out an enzyme-labeled stabilizer suitable for p30 monoclonal antibody 16-5E7E8-HRP.Furthermore,the sensitivity of the established p30-cCLIA method was higher than that of the commercial blocking ELISA kit(1∶2 048 vs 1∶512)and exhibited good repeatability.Detection of sera positive for other porcine virus infections showed no cross-reactivity.The estab-lishment of this method provides a powerful tool for early diagnosis of ASF.

Although no cross protection was observed between different serotypes of foot-and-mouth disease virus(FMDV),there were cross-reactivity between different serotypes of antibodies produced after vaccination,the aim of this paper was to prepare the neutralizing monoclonal anti-body against Foot-and-mouth disease virus(FMDV)serotype O,and to develop the method to dis-tinguish antibody against FMDV serotype O and A based on mAb.The inactivated FMDV serotype O was used as antigen in mAb production,a series of GST fusion overlapping peptides and trun-cated peptides expressed in Escherichia coli were used to identify antigenic epitope recognized by monoclonal antibodies.In order to verify feasibility of the screened monoclonal antibodies in diag-nosis,20 positive serum of FMDV serotype O and A,20 negative serum with known background were detected by blocking ELISA.Results were as follows:five monoclonal antibodies were suc-cessfully screened.The five monoclonal antibodies showed good reactivity with FMDV serotype O,but did not react with FMDV serotype A by Western blot and IFA,these mAbs showed neutrali-zing ability to FMDV/O/MY98/GZBY/2013 by VNT.The same epitope was identified by five monoclonal antibodies,the minimum epitope was145 RGDLQVLA152,Arg145 and Gln149 were key a-mino acids of the epitope.Sequence alignment analysis revealed that the identified epitopes were conserved among most of O type FMDV strains,but Gln149 was mutated among all A,Asia 1 and SAT1-3 type FMDV strains.The mAb-8C5D3 distinguished between antibody of FMDV serotype O and FMDV serotype A by blocking ELISA.The results provided materials for development of O type FMDV antibody detection kit and evaluation of vaccine immune effect.

Although no cross protection was observed between different serotypes of foot-and-mouth disease virus(FMDV),there were cross-reactivity between different serotypes of antibodies produced after vaccination,the aim of this paper was to prepare the neutralizing monoclonal anti-body against Foot-and-mouth disease virus(FMDV)serotype O,and to develop the method to dis-tinguish antibody against FMDV serotype O and A based on mAb.The inactivated FMDV serotype O was used as antigen in mAb production,a series of GST fusion overlapping peptides and trun-cated peptides expressed in Escherichia coli were used to identify antigenic epitope recognized by monoclonal antibodies.In order to verify feasibility of the screened monoclonal antibodies in diag-nosis,20 positive serum of FMDV serotype O and A,20 negative serum with known background were detected by blocking ELISA.Results were as follows:five monoclonal antibodies were suc-cessfully screened.The five monoclonal antibodies showed good reactivity with FMDV serotype O,but did not react with FMDV serotype A by Western blot and IFA,these mAbs showed neutrali-zing ability to FMDV/O/MY98/GZBY/2013 by VNT.The same epitope was identified by five monoclonal antibodies,the minimum epitope was145 RGDLQVLA152,Arg145 and Gln149 were key a-mino acids of the epitope.Sequence alignment analysis revealed that the identified epitopes were conserved among most of O type FMDV strains,but Gln149 was mutated among all A,Asia 1 and SAT1-3 type FMDV strains.The mAb-8C5D3 distinguished between antibody of FMDV serotype O and FMDV serotype A by blocking ELISA.The results provided materials for development of O type FMDV antibody detection kit and evaluation of vaccine immune effect.

African swine fever(ASF)is an acute,febrile,and highly fatal disease caused by African swine fever virus(ASFV)in pigs.Given the current lack of commercial vaccines and the continu-ous evolution of ASFV in recent years,the emergence of moderately virulent genotype Ⅱ strains and the introduction of genotype Ⅰ attenuated strains have led to persistent and chronic infections in pigs.Therefore,the detection of specific antibodies against ASFV has become imperative.In this study,we established a competitive chemiluminescence immunoassay(p30-cCLIA)for detecting ASFV p30 antibodies using p30 monoclonal antibodies.By detecting sera with clear negative and positive backgrounds,we determined that the Cut-off value of this method was 50％,with both di-agnostic sensitivity(Dsn)and diagnostic specificity(Dsp)reaching 100％.Under optimal reaction conditions,we screened out an enzyme-labeled stabilizer suitable for p30 monoclonal antibody 16-5E7E8-HRP.Furthermore,the sensitivity of the established p30-cCLIA method was higher than that of the commercial blocking ELISA kit(1∶2 048 vs 1∶512)and exhibited good repeatability.Detection of sera positive for other porcine virus infections showed no cross-reactivity.The estab-lishment of this method provides a powerful tool for early diagnosis of ASF.

African swine fever(ASF)caused by African swine fever virus(ASFV)is a febrile,hem-orrhage and highly fatal infectious disease in pigs,which poses a serious threat to the global pig in-dustry.Currently,no vaccine is available for the prevention and control of ASF,and several ASF vaccines,including gene deletion attenuated live vaccines,live vector vaccines,and subunit vaccines are under the development stage in the laboratory research.As one of the most promising vaccines,live vector vaccine has the characteristic of safety and simulation of the pathogen natural infection to effectively stimulate the innate and adaptive immune responses,which becomes one of the hotspots in the research and development of novel ASF vaccines.This review focuses on the pro-gress in using modified viruses as vectors for ASF live vector vaccines,and aims to provide valua-ble information for future development of safe and effective ASF vector vaccines.

Objective:To analyze and summarize the implementation effect of basic essential surgical training (BEST) course of laparoscopic skills over the past 10 years and the practical experience in updating course content and models.Methods:The pre-class assessment questionnaires, basic laparoscopic operation assessment results, and post-class assessment questionnaires of the students who participated in the BEST course of laparoscopic skills were collected. According to the period of the course construction, the students were divided into two groups, namely students who used the course of single training system in the early stage (traditional group) and students who used the course integrating a variety of training systems after the course model was updated in the later stage (test group). The two groups were compared for the scores of track circle moving, tunnel crossing, and high and low columns, as well as their subjective evaluation of course setting and implementation effect. The t-test, Wilcoxon test, or chi-square test was conducted according to the data type using SPSS 13.0. Results:The time for 150 traditional group students to complete track circle moving, tunnel crossing, and high and low columns was 1.08 min (0.81 min, 1.60 min), 2.20 min (1.60 min, 3.27 min), and 4.86 min (3.28 min, 6.36 min), respectively, while the time for 75 test group students to complete the three operations was 1.27 min (0.87 min, 1.83 min), 2.57 min (1.58 min, 4.07 min), and 4.35 min (2.90 min, 6.42 min), respectively, with no significant difference between the two groups ( P>0.05). In terms of students' subjective evaluation of the course, a higher percentage of the test group students were satisfied with classroom environment, teaching method arrangement, training equipment, training opportunities, helping clinical work, and meeting pre-class expectations than those in the traditional group. Conclusion:The constantly updated BEST course can ensure the training quality of trainees and obtain their higher satisfaction. The benefits of this course in clinical practice can be further verified through long-term follow-up of these trainees.

Objective: To establish a prediction model for the distant metastasis of breast cancer based on qualitative magnetic reso-nance imaging (MRI) parameters. Methods: A retrospective analysis of 3,032 patients with breast MRI from January 2011 to Decem-ber 2016 in Tianjin Medical University Cancer Institute and Hospital was conducted. After the confirmation of invasive breast cancer, the subjects were divided in 2 groups: metastasis and metastasis-free. A total of 93 patients were included in the metastasis group, and 186 patients without the presence of distant metastasis in the metastasis-free group. We analyzed the correlation between breast cancer molecular subtypes and distant metastasis in the metastasis group. Univariate and Logistic regression analyses of qualitative MRI features were performed for the groups. Subsequently, we used the results to establish prediction models. Results: The results showed that hormone receptor-positive tumors (Luminal type) had a greater tendency to develop bone metastasis in the metastasis group. Triple-negative tumors showed a greater tendency to develop lung metastasis. Human epidermal growth factor receptor 2 gene overexpression cases were more likely to develop liver metastasis. The results of the univariate analysis showed that the type of le-sion, multifocality or multicentricity of the cancer, T1-weighted signal uniformity, T2-weighted signal uniformity, and tumor size were statistically different between the groups (P<0.05). The results of the logistic regression analysis showed that the type of lesion, multi-focality or multicentricity of the cancer, T2-weighted signal uniformity, and tumor size were independent predictors of distant metasta-sis. Based on select independent predictors, we established a prediction model for the distant visceral metastasis of breast cancer. The accuracy, area under the curve, sensitivity, and specificity of the model were 82.8%, 0.801, 85.7%, and 75.0%, respectively. Conclu-sions: The prediction model based on the clinical pathology and MRI features established in this study can predict the distant metasta-sis of breast cancer.

Objective To investigate the magnetic resonance imaging (MRI) features and differential diagnosis of axillary schwannomas, and analyze the causes of misdiagnosis. Methods A retrospective study from October 2014 to October 2017 was performed in 5 patients with axillary schwannomas, confirmed by surgery and pathology, in whom clinically suspected axillary metastases have been diagnosed. All the patients underwent breast MRI to summarize the key points of diagnosis and differential diagnosis. Results Five tumors located in neurovascular bundles extending along the brachial plexus nerve distribution. The tumors presented as single, spindle or ovoid masses, well-circumscribed margins in 4 cases, entering and exiting nerve signs in 5 cases, the split fat sign in 4 cases, vascular compressed sign in 5 cases, and target sign in 1 case. The tumors were isointense or slight hypointense on T1WI compared to the adjacent muscle. Three tumors manifested heterogeneous slight hyperintense, 1 tumor was slight hyperintense, and the target sign was seen in 1 tumor on T2WI. Diffusion-weighted image was heterogeneous hyper or slightly hyper-intense. When b＝500 and 1 000 s/mm2, the apparent diffusion coefficient (ADC) was (1.40 - 2.23) × 10 -3mm2/s and (1.31 -2.94) × 10-3mm2/s respectively. All the 5 tumors manifested persistent enhancement on dynamic contrast-enhanced MRI (DCE-MRI). Three tumors were heterogeneously enhanced, and 2 tumors were circularly enhanced. Conclusions Axillary schwannomas has certain characteristics which can be helpful for the identification of metastatic lymph nodes.

Objective This study examined the prevalence of underweight and its related risk factors of community-dwelling patients with schizophrenia. Methods Five hundred and three community-dwelling patients with schizophrenia and 323 healthy controls were recruited in a cross-sectional study. Body mass index less than 18.5 was defined as underweight. Their demographic and clinical data including anthropometric data, plasma glucose and lipid parameters were collected. The Positive and Negative Syndrome Scale (PANSS) was used to assess patients' psychopathology. Results The prevalence of underweight was 9.9% (50/503) in schizophrenia patients versus 1.5% (5/323) in the control group ( P<0.01). Further logistic regression analysis showed that male ( OR=2.43, 95%CI:1.74~3.39), smoking behavior (OR=1.50, 95%CI: 1.21~1.86), hospitalization times (OR=1.18, 95% CI: 1.06~1.31), PANSS negative score (OR=1.09, 95% CI: 1.04~1.14) were significant predictors for underweight (all P<0.05). Conclusion The prevalence of underweight is higher in Chinese patients with schizophrenia than in the general population. Some demographic and clinical variables are risk factors for underweight in schizophrenia.