Objective:To disclose phylogenetic and antigenic characteristics of hemagglutinin (HA) gene of influenza B virus (Victoria) (BV) in the 2023-2024 influenza surveillance season in Beijing, and understand the matching with influenza vaccine component strain.Methods:Pharyngeal swab specimens from influenza like-illness (ILI) in the 2023-2024 influenza surveillance season were collected from surveillance network labs in Beijing and BV strains were isolated through MDCK or chicken embryo culture. After extracting nucleic acid, HA gene was amplified and sequenced. The nucleotide and amino acid sequence identity were conducted and the maximum likelihood method in Mega 5.0 software was used to construct the phylogenetic tree of HA gene. N-glycosylation sites of HA were performed online. Furthermore, three-dimensional structure of HA was available from SWISS-MODEL homologous modeling. Hemagglutination inhibition (HI) tests were performed to analyze antigenic characteristics of HA of BV strains.Results:Fifty-four BV strains were randomly selected to be analyzed further. Compared with the HA gene of this influenza season vaccine strain (B/Austria/1359417/2021), there are three amino acid mutations among all BV strains, two of which are located in two different antigenic determinants. Furthermore, the phylogenetic tree analysis revealed that only one subgroup of 1A.3a.2 was circulating simultaneously. All BV strains are located in Clade 1A.3a.2 subgroup, and in the same subgroup with that of the vaccine component BV strain in 2023-2024. All BV strains have the same glycosylation sites as that of the vaccine component BV strain in 2023-2024. Antigenic analysis showed that all BV strains were antigenically similar with its vaccine strain.Conclusions:In the 2023-2024 influenza surveillance season, the prevalent BV strains in the population in Beijing city are located in Clade 1A. 3a. 2 subgroup. The antigen matching between BV epidemic strains and vaccine BV components is relatively high during this surveillance season.

Objective:To investigate the phylogenetic and antigenic characteristics of hemagglutinin (HA) gene of influenza B/Victoria lineage (BV) viruses in Beijing during the 2021-2022 influenza surveillance season, and to analyze whether the circulating BV viruses match the vaccine strain.Methods:Pharyngeal swab specimens from influenza like-illness (ILI) cases in the 2021-2022 influenza surveillance season were collected from surveillance network labs in Beijing and cultured in MDCK cells and chicken embryo to isolate BV viruses. Nucleic acids of the viruses were extracted, and the HA gene was amplified and sequenced. The nucleotide and amino acid sequence identity of the HA gene was analyzed using MEGA5.0 software. A phylogenetic tree of HA gene was constructed using the maximum likelihood method. The N-glycosylation sites in HA were predicted online. Three-dimensional structure of HA was constructed using SWISS-MODEL homologous modeling. Hemagglutination inhibition (HI) test was performed to analyze the antigenicity of BV viruses.Results:A total of 402 BV viruses were collected and 58 strains with full-length HA gene sequences were chosen for further analysis. Compared with the HA gene of this year′s vaccine strain (B/Washington/02/2019), there were 27 amino acid mutations, 11 of which were located in four different antigenic determinants. The phylogenetic analysis revealed that three subgroups of 1A.3, 1A.3a1, and 1A.3a2 co-circulated in Beijing with 54 strains (54/58, 93.10%) clustered to the Clade 1A.3a2, two strains (2/58, 3.45%) clustered to the Clade 1A.3a1, and two strains (2/58, 3.45%) in the same subgroup (Clade 1A.3) as the vaccine component BV strain in 2021-2022. Compared with the vaccine strain (B/Washington/02/2019), two BV strains had an additional N-glycosylation site at residue 197, while the other 56 strains showed no change in N-glycosylation sites. Antigenic analysis showed that 35 BV strains (35/58, 60.34%) were antigenically similar to the vaccine strain and 23 strains (23/58, 39.66%) were low-response strains.Conclusions:Three subgroups of BV viruses co-circulated in Beijing during the 2021-2022 influenza surveillance season. The predominant subgroup was Clade 1A.3a2 (93.10%), showing a certain genetic distance with the vaccine strain (B/Washington/02/2019). Nearly 40% (39.66%) of the viruses were low-response strains. This study indicated that continuous monitoring of the variations of influenza epidemic strains and timely providing laboratory basis for screening vaccine component strains were the basic technical guarantee for coping with influenza pandemic.

Objective:To understand the epidemic situation of Redondoviridae in Beijing and analyze its epidemiologic characteristics.Methods:Pharyngeal swab samples of healthy people and patients with acute respiratory infection in Beijing, including influenza like cases and severe acute respiratory infection (SARI) cases in hospitals were collected. Real time PCR was used to detect the nucleic acid of Redondoviridae. The positive samples were amplified and sequenced to analyze their species. The age and sex distribution of patients and species distribution of Redondoviridae were obtained through statistical analysis. Multiplex PCR was used to detect other common respiratory pathogens in the positive samples of Redondoviridae in influenza like cases and SARI cases, and the pathogenicity of Redondoviridae was analyzed.Results:The positive rates of Redondoviridae in healthy people and acute respiratory infection cases were 20.48% (189/923) and 11.23% (43/390), respectively, with a statistically significant difference ( P<0.05). The positive rate of male was higher than that of female in the healthy population, and the positive rate of the elderly group was higher than that of the adult group and the underage group, with a statistically significant difference ( P<0.05). The positive rate of male patients with acute respiratory tract infection was higher than that of female patients, but there was no significant difference. The proportion of Vientovirus in the positive samples of Redondoviridae was higher than that of Brisavirus, and the difference was statistically significant ( P<0.05). Among the throat swabs of respiratory tract infection cases, 43 were positive for Redondoviridae, of whom 24 were not detected for other pathogens. Conclusions:Redondoviridae widely exists in healthy people of all age groups in Beijing, and is also found in acute respiratory infection cases. The positive rate of Redondoviridae is different in different ages and genders. Both Vientovirus and Brisavirus were detected, and the proportion of Vientovirus was significantly higher than Brisavirus.

Objective:To characterize the epidemic of influenza in Beijing from 2022 to 2023 and the variation of gene and antigenicity of hemagglutinin (HA) of influenza A H3N2 virus, so as to provide scientific basis for influenza prevention and control in Beijing.Methods:Statistical analysis was carried out on the result of influenza pathogenic monitoring in Beijing from week 14, 2022 to week 20, 2023, and 79 strains of influenza A H3N2 virus were selected at different time and population sources, and their genetic variation and evolution characteristics were analyzed through HA gene amplification sequencing and antigenicity analysis.Results:From week 14, 2022 to week 20, 2023, 24 244 throat swabs of influenza like cases were collected in Beijing, and 4 987 influenza virus nucleic acid positive cases were detected, including 2 749 influenza A H3N2 positive cases, with a detection rate of 11.34%. Among the 79 strains, 50 strains (63.29%) showed low response, 94.44% of the strains from August to November 2022 had low response, and 54.10% of the strains from February to March 2023 had low response, with a statistically significant difference ( χ2=8.079, P=0.004). Compared with the vaccine strain A/Darwin/9/2021, the HA gene sequence of 79 strains of influenza A H3N2 showed nucleotide similarity of 97.47% to 98.47% and amino acid similarity of 97.05% to 98.17%. Genetic evolution analysis showed that the 18 strains isolated from August to November 2022 were all distributed in the 3C.2a1b.2a.1a.1 branch, while the 61 strains isolated from February to March 2023 all belonged to the 3C.2a1b.2a.3a.1 branch. Compared with the vaccine strain, there were multiple site mutations distributed at multiple antigenic determinants and receptor binding sites in A, B, C, D, and E. All strains had potential glycosylation sites of 8NST, 22NGT, 38NAT, 45NSS, 63NCT, 126NWT, 133NGT, 246NST, 285NGS, 483NET, while one strain missed 165NVT glycosylation sites; 55 strains between February and March 2023 missed 122NES glycosylation sites. Conclusions:The HA gene locus of influenza A H3N2 virus detected in Beijing from week 14, 2022 to week 20, 2023 showed multiple mutations, continuous monitoring of this subtype variation is crucial.

Objective:To predict the inflammatory activity of patients with ankylosing spondylitis (AS) after 12 weeks treatment with recombinant human tumor necrosis factor-α receptor Ⅱ immunoglobulinG Fc fusion protein (rhTNFR:Fc) by Doppler ultrasonography at baseline.Methods:A total of 60 patients with AS were selected, and their general clinical characteristics before and after treatment were compared. Meanwhile, Doppler ultrasonography of the sacroiliac joint was performed to compare the Doppler parameters before and after treatment, and the correlation between baseline Doppler ultrasonography and clinical characteristics was analyzed, along with its diagnostic performance. The pre-treatment and post-treatment parameters were compared to the measured data followed by paired t-test for normal distribution, and the counting data were paired with Chi- square test. Pearson correlation test was used to analyze the correlation between pretreatment ultrasound parameters and pre-treatment disease activity. All statistical tests were bilateral, with a statistically significant difference of P<0.05. Results:After treatment, the overall score [(1.4±1.0) points vs (6.0±1.8) points, t=17.80, P<0.001], night pain score [(1.6±1.2) points vs (5.7±1.5) points, t=15.80, P<0.001], back pain score [(1.9±1.3) points vs (5.5±1.2) points, t=16.39, P<0.001], morning stiffness [(12±6) min vs (38±21) min points, t=8.93, P<0.001], Bath ankylosing spondylitis disease activity index (BASDAI) [(1.1±0.6) vs (4.6±1.3), t=12.41, P<0.001], ankylosing spondylitis disease activity score-C-reactive protein (ASDAS-CRP) [(1.0±0.4) points vs (3.7±0.9) points, t=22.01, P<0.001] and ASDAS-erythrocyte sedimentation rate (ESR) [(1.0±0.7) points vs (4.0±0.8) points, t=20.10, P<0.001] of patients with ankylosing spondylitis were lower than those before treatment, and the differences were statistically significant ( P<0.001). Compared with AS patients before treatment, the color blood flow grading score was significantly lower after treatment [(1.7±0.8) points vs (3.9±1.1) points, t= 12.86, P<0.001). The post-treatment proportion of AS patients with bilateral sacroiliac joint blood flow signal was 67% (40/60), which was lower than 87% (52/60) before treatment, but the difference was not statistically significant ( P=0.251). After treatment, the peak systolic velocity (PSV), pulsatile index (PI) and resistance index (RI) were significantly higher than those before treatment [(30±17) cm/s vs (19±8) cm/s, t=-5.42, P<0.001; (1.55±0.69) vs (1.00±0.45), t=0.45, P<0.001; (0.81±0.11) vs (0.55±0.14), t=11.20, P<0.001)]. The end diastolic velocity (EDV) before and after treatment had no statistical significant differences [(6.7±2.5) cm/s vs (6.3±1.9) cm/s, t=0.80, P=0.428]. Baseline Doppler ultrasound parameters and pre-treatment clinical indicators showed that PI and RI were negatively correlated with BASDAI ( r=-0.49, P=0.005; r=-0.51, P<0.001) , and blood flow grades were positively correlated with BASDAI ( r=0.46, P=0.028). However, there were no significant correlation between PSV, EDV and BASDAI ( r=-0.12, P=0.176; r=0.03, P=0.756). Baseline Doppler ultrasound parameters were correlated with ASDAS-CRP ( r=-0.45, P=0.012; r=0.29, P<0.048; r=-0.52, P<0.035; r=-0.76, P<0.001; r=0.61, P<0.001). There was no correlation between EDV and ASDAS-ESR ( r=0.30, P=0.110), the other ultrasound Doppler parameters were correlated with ASDAS-ESR ( r=-0.36, P<0.001; r=-0.54, P<0.001; r=-0.61, P=0.021; r=0.41, P=0.028). The receiver operating characteristic curve was drawn with the baseline RI value as a variable. According to the ASDAS-CRP value, the diagnostic threshold for determining the presence or absence of AS activity after 12 weeks of treatment was 0.49, with an area under the curve of 0.817, sensitivity of 88.1%, specificity of 61.1%, positive predictive value of 66.7%, and negative predictive value of 86.1%. Conclusion:Baseline Doppler ultrasound correlates well with clinical indicators, among which baseline RI values is a good predictor of inflammatory activity status after rhTNFR:Fc treatment.

Objectives:To investigate the clinical impacts of chronic total occlusion (CTO) in acute non-ST segment elevation myocardial infarction (NSTEMI) patients underwent primary percutaneous coronary intervention (PCI).Methods:A total of 2 271 acute NSTEMI patients underwent primary PCI from China Acute Myocardial Infarction Registry were enrolled in this study and divided into the CTO group and the non-CTO group according to the angiography. The primary endpoint was in-hospital mortality and mortality during a 2-year follow-up. The secondary endpoint was major adverse cardiovascular events (MACE) including revascularization, death, re-myocardial infarction, heart failure readmission, stroke and major bleeding.Results:Thirteen-point four percent of the total acute NSTEMI patients had concurrent CTO. In-hospital mortality (3.6% vs. 1.4%, P<0.01) and 2-year mortality (9.0% vs. 5.1%, P<0.01) were significantly higher in the CTO group than those in the non-CTO group, respectively. Multiple regression analyses showed that chronic obstructive pulmonary disease ( HR 7.28, 95% CI 1.50-35.35, P=0.01) was an independent risk factor of in-hospital mortality, and advanced age ( HR 1.04, 95% CI 1.01-1.07, P<0.01), and low levels of ejection fraction ( HR 0.95, 95% CI 0.93-0.98, P<0.01) were independent risk factors of 2-year mortality. CTO ( HR1.67, 95% CI 1.10-2.54, P=0.02) was an independent risk factor of revascularization, but not a risk factor of mortality. Conclusions:Although acute NSTEMI patients concurrent with CTO had higher mortality, CTO was only an independent risk factor of revascularization, but not of mortality. Advanced age and low levels of ejection fraction were independent risk factors of long-term death among acute NSTEMI patients.

Objective:To clarify the M protein ( emm gene) types and drug susceptibility characteristic variations of Group A Streptococcus (GAS) in children in Beijing. Methods:The GAS strains isolated from throat swab samples of children diagnosed with scarlet fever and pharyngeal infection in scarlet fever etiology surveillance sentinel hospitals in 16 districts of Beijing in 2018, 2019 and 2021 were analyzed retrospectively.PCR amplification and sequencing were used for emm genotyping, and the minimum inhibitory concentrations (MIC) of 10 antibiotics were determined by the broth microdilution method.The data were analyzed using χ2 test and Fisher′ s exact method between groups. Results:A total of 557 GAS strains were collected, and 11 emm genotypes ( emm1, emm3, emm4, emm6, emm11, emm12, emm22, emm75, emm89, emm128, and emm212) were detected.Of 557 strains, 238 trains were of emm1 type (42.73%), 271 strains were of emm12 type (48.65%) and 48 strains were of other emm types (8.62%). The detection rates of emm1, emm12 and other emm type genes in 2018, 2019, and 2021 were [37.50% (105/280 strains), 57.14% (160/280 strains), 5.36% (15/280 strains)], [49.05% (129/263 strains), 39.54% (104/263 strains), 11.41% (30/263 strains)], and [28.57% (4/14 strains), 50.00% (7/14 strains), 21.43% (3/14 strains)], respectively.In children infected with emm12 in 2018 and 2019, there were more children under 6 years old than children over 6 years old (62.50% vs.46.88%, 46.36% vs.30.36%) (χ 2=7.182, 6.973; all P<0.05). Drug susceptibility testing results suggested that 225 randomly selected GAS strains were all 100.00% sensitive to 7 antibiotics including Penicillin, Levofloxacin, Meropenem, Linezolid, Cefotaxime, Cefepime and Vancomycin.The rates of resistance to Erythromycin, Tetracycline and Clindamycin were [88.57% (93/105 strains), 87.62% (92/105 strains), 86.67% (91/105 strains)], and [94.34% (100/106 strains), 94.34% (100/106 strains), 87.74% (93/106 strains)] in 2018 and 2019, respectively.The test strains were 100.00% (14/14 strains) resistant to the above 3 antibiotics in 2021.MIC 50 and MIC 90 values of Penicillin in 2018, 2019, and 2021 were (0.03 mg/L, 0.03 mg/L), (0.03 mg/L, 0.06 mg/L), and (0.06 mg/L, 0.06 mg/L), respectively.Among 225 GAS strains, 207 strains had drug resistance and were resistant to more than one drug.Specifically, 94.69% (196/207 strains) were resistant to Erythromycin, Tetracycline and Clindamycin.About 4.35% (9/207 strains) were resistant to both Erythromycin and Clindamycin.A total of 0.97% (2/207 strains) were resistant to Erythromycin and Tetracycline. Conclusions:The emm genotypes of GAS in children in Beijing are diverse in 2018, 2019 and 2021.The dominant genotypes are emm12 and emm1, and emm12 is the main epidemiological type.GAS strains maintain highly resistant to Erythromycin, Clindamycin and Tetracycline, and sensitive to Penicillin and other antibiotics.However, MIC 50 and MIC 90 of Penicillin shows an ascending trend.

Objective: To understand the antigenicity and genetic characterization of influenza B virus HA gene in B/Victoria-lineage virus (BV) in Beijing during 2017-2018. Methods: Thirty BV virus strains isolated from MDCK cell culture by 17 laboratories in Beijing were collected. The antigenicity was analyzed by comparing with the vaccine strain recommended by WHO. The total viral nucleic acid was extracted and HA gene was amplified by RT-PCR and sequenced. The phylogenetic tree was constructed by HA and mutant sites were analyzed. Results: Among 30 strains of BV, 23 strains (76.7%) were low-reactive strains, other 7 strains (23.3%) were related to the vaccine. The phylogenetic analysis showed that the HA gene of all 30 strains located in Clade 1A branch. In addition, amino acid mutations occurred in 8 sites, and 6 of them located in the antigen determining region. Conclusions There was a correlation between the high proportion of low-reactive antigenicity and 6 aa variation in antigenic determinants involved in HA region of BV influenza virus between 2017-2018, which provides an important laboratory basis for the recommendation of BV influenza vaccine.

Objective: To investigate the efficacy of bare metal stent for treating focal coronary artery aneurysm complicating with severe stenosisin single coronary artery. Methods: This retrospective analysis was performed in 7 patients who were diagnosed as local coronary artery aneurysm complicating with severe stenosis(≥70%) in single coronary artery and treated with bare metal stent during the period from December 2012 to June 2015 in Fuwai Hospital. All 7 patients were male with age of (62±11) years old. During the interventional operation, the narrow parts were pre-expanded,and all patients received bare metal stents implantation to cover aneurysms.The clinical and imaging data of patients immediately post procedure and at postoperative follow-up were collected to evaluate the clinical efficacy. Results: There were 5 cases of left anterior descending aneurysms and 2 cases of right coronary artery aneurysms. The diameter of aneurysm was (5.21±1.28)mm, and the length was (13.71±3.88)mm. There was intracranial vortex in coronary arteriography immediately after intervention.Proximalstenosis of coronary artery aneurysm was disappeared,and the distal blood flow was TIMI class 3.There were no signs of aortic dissection and thrombus formation.During 6(6 16) months follow-up, the aneurysms were disappeared,and there were no major adverse cardiovascular events which including myocardial ischemia, acute myocardial infarction, revascularization,bleeding,and death for all patients. Conclusion Initial experience shows that double-layer bare metal stents implantation for patients with localized coronary artery aneurysm complicating with severe stenosis in single vessel is safe and effective.

Objective To prepare anti-folic acid (FA) polyclonal antibody and develop a new non-balanced competing chemiluminescence analysis for clinical detection of FA.Methods Established the detection method by added FITC-FA-analogs and FAHRP-antibody in the light emitting plate,which coated with anti-FITC antibody,to form the immune response complex of FITC/antibody-FITC-FA-analogs/FA-antibody-HRP.Then methodology evaluation was performed to evaluate the method performance;and further compared the detecting results with non-FITC system detection system and Electrochemiluminescence system (Roche Elecsys 2010).Results The ELISA results showed that the prepared anti-FA antibodies can recognize serum FA specificly.The methodology evaluation indicated that the linear correlation coefficient of the standard curve was 0.990 0;the analytical sensitivity was 1.21 ng/mL;the range of linear detection was 1.21～ 38.80 ng/mL;The coefficient variability of intra-assay was ＜5 ％,which was better than the results of non-FITC detection system;and the correlation coefficient was 0.908 1 compared with the Elecsys-2010 detection system.Conclusion The established chemiluminescence immunoassay for human serum FA has a good sensitivity and specificity,and suitable for clinical serum FA quantitativedetecting.