Objective To observe and evaluate the changes in plasma C3a and C5a concentration after injecting protamine via two different pathways:ascending aorta and superior vena cava.Methods Sixty children with age under 1-year-old who underwent cardiopulmonary bypass were randomly divided into two groups:experimental group(injecting protamine via ascending aorta,n =30)and control group(injecting protamine viasuperior vena cava,n =30;).The plasma concentration of C3a and C5a were measured by ELISA at prior to protamine injected(Time 1)and 1 hour after the protamine injected(Time 2).Results In experimental group,there was no statistical difference on C3a and C5a concentration before and after injection of protamine[C3a:(18.762±3.792) μg/L vs(19.554±3.453) μg/L,t =-0.846,P =0.20; C5a:(0.843±0.159) μg/L vs (0.825±0.119) μg/L,t =0.496,P =0.31].In control group,C3 a concentration increased from(18.780±3.864) μg/L to(22.961±3.501) g/L,C5a concentration increased from(0.839±0.157) μg/L to(0.979±0.116)μg/L after injection of protamine,and the differences were significant(t =-4.392,-3.928,respectively,P ＜0.01).The level of C3a concentration in experimental group was significantly higher than that in control group[(19.554±3.453) μg/L vs.(22.961±3.501) μμg/L,ι =3.795,P < 0.01]after injection of protamine for 1 h and the level of C5a concentration exhibited the same change[(0.825±0.119) μg/L vs.(0.979±0.116)μg/L,t =-5.075,P ＜0.01].Conclusion The levels of C3a and C5a concentration of infants underwent cardiopulmonary bypass are decreased significantly after protamine injected via ascending aorta compated with via superior vena cava.

Objective:To study the clinical characteristics of neonatal umbilical vascular catheter (UVC) rupture.Methods:A neonate with UVC rupture admitted to Neonatology Department of our hospital was retrospectively reviewed. Literature on this subject were searched in the following databases: Chinese Medical Journal full-text Database, CNKI, Wanfang Database, CQVIP database, PubMed, Web of Science, Embase and Cochrane Library (up until March 15 2022). The causes, treatment and prognosis of neonatal UVC rupture were analyzed.Results:In our case, the UVC was accidentally damaged during the removal of the ligature suture. The UVC was ruptured after a slight force was applied to remove the catheter, resulting in approximately 7 cm of UVC remaining in the body. Trans-umbilical vein intervention was performed and the catheter was successfully removed with a lasso under X-ray guidance. A total of 33 UVC rupture cases were included from 15 articles (no case report in China before). In 16 cases (47.1%), the UVCs were accidentally cut off by knife or scissors when removing the catheter. In 3 cases (8.8%), the UVCs were broken during insertion. The UVC was broken in 1 case (2.9%) during flushing the catheter. The causes of the other 14 cases (41.2%) were unknown. 9 cases (26.5%) had clinical manifestations, including respiratory distress, prominent heart murmur, sepsis and limb ischemia. 20 cases (58.8%) showed no clinical features. No data on the other 5 cases (14.7%). 21 cases (61.8%) received vascular intervention removal, 11 cases (32.4%) received surgical removal, 1 case (2.9%) was removed with tweezers, and 1 case (2.9%) died before UVC was removed. Among the neonates receiving surgical treatment, 1 case died of sepsis on the second day after surgery and 1 case had sequela of limb ischemia. 2 cases had postoperative vasospasm and embolism after vascular intervention with overall good prognosis.Conclusions:The rupture of UVC in neonates is rare and mainly related with knife and scissors injury.

Objective: To prepare strains of influenza A (H7N9) pseudovirus derived from different districts of China for vaccine efficacy evaluation. Methods: Phylogenetic tree was built based on hemagglutinin (HA) amino acid sequence analyses from 29 influenza A (H7N9) virus strains and 6 influenza A (H7N9) virus strains with HA determinants variation were selected. 293FT cells were co-transfected with plasmid pNL4-3-Luc.R-E-, pVRC-HA and pVRC-NA with codon-optimized hemagglutinin (HA) and neuraminidase (NA) derived from the six influenza A (H7N9) virus strains, respectively. Transmission electron microscopy assay and Western blot analysis were performed to demonstrate morphology and specificity of these particles, luciferase activity assay and hemagglutinin titers detection were used to determine their infectivity and hemagglutinin activity. And finally, pseudovirus-based neutralization assays were evaluated with HA immunized mice serum. Results: Six influenza A (H7N9) peseudovirus particles derived from different districts of China were selected and prepared. All of the particles bearing HA and NA were characterized with classic influenza virus morphology, with TCID₅₀ titer ranged from 10⁴TCID₅₀/50 μl to 10⁵TCID₅₀/50 μl and with hemagglutinin activity ranged from 64 to 512. Neutralization efficacies on influenza A/Shanghai/1/2013(H7N9) HA vaccine serum against 100TCID₅₀ dose of these pseudovirus particles indicated their potential application in the vaccine cross-protective evaluation in future. Conclusions Six influenza A (H7N9) pseudovirus derived from different districts of China with potential antigenic variation on HA were constructed successfully, established foundation for their further application in vaccine cross-reactive efficacy evaluation.

Objective: To explore the characteristics of thrombelastogaphy (TEG) in term neonates, and to evaluate their correlation with traditional coagulation tests. Methods: A total of 52 term neonates were enrolled as neonatal group and 34 adults undergoing elective surgery as adult control group in Jiangmen Central Hospital from January to December 2017.TEG, plasma coagulation test and platelet counts (PLT) were performed and the corresponding ana-lysis was conducted. Results: TEG parameters in term neonates: response time(R)(4.18±1.08)min, clot kinetics(K)(1.21±0.45) min, α angle (Angle)(73.08±5.74)°, maximum amplitude(MA)(65.68±7.13)mm.Compared with adult control group, neonatal group exhibited shorter R and K(t=3.764, P<0.001; t=4.888, P<0.001), higher Angle, MA(t=5.539, P<0.001; t=2.873, P=0.001). In traditional coagulation, compared with adult control group, neonatal group showed longer prothrombin time(PT), activated partial thromboplastin time(APTT), thrombin time(TT) (t=5.449, P<0.001; t=13.134, P<0.001; t=3.575, P=0.001), lower fibrinogen(Fib) (t=4.164, P<0.001), and higher PLT (t=4.230, P<0.001). In addition, K was negatively correlated with Fib(r=-0.374, P=0.004), while Angle and MA were positively correlated with Fib(r=0.354, P=0.007; r=0.630, P<0.001); K was negatively correlated with PLT(r=-0.430, P=0.001), but Angle and MA were positively correlated with PLT (r=0.427, P=0.001; r=0.586, P<0.001); K was positively correlated with APTT(r=0.285, P=0.035), and MA was negatively correlated with APTT(r=-0.324, P=0.017). There was no significant correlation between R and traditional coagulation test.K, MA and Angle were not significantly correlated with PT (all P>0.05), and Angle and APTT were not significantly correlated (all P>0.05). Conclusions The reference interval of TEG in term neonates is different from adults.And the parameters of TEG in term neonates are partly related to the traditional coagulation tests.

Objective: To investigate the smartphone addiction among college students during the Coronavirus Disease 2019 (COVID-19) pandemic and its association with daily behaviors and mental health,and to provide reference for heath education and psychological counseling for college students. Methods: An observational study using online quyestionnaire was conducted among 10 357 college students of two provincial medical schools in Guangdong and Shanxi Province from February 24th to March 4th in 2020. Participants were investigated on demographic information, smartphone addiction, daily routine, physical activity, weight status, anxiety, and other health information. Logistic regression with inverse probability treatment weighting (IPTW) based on propensity score was used to analyze the association between smartphone addiction with daily behavior and mental health. Results: The prevalence of smartphone addiction was 59.42%. The prevalence of phone addiction was higher in postgraduates, senior undergraduates, students with non-medical major, students living in GuangDong and those without regular exercise habit before vacation(χ 2=47.91，17.78，42.75，138.58，P<0.05). With IPTW, there were significant associations between smartphone addiction and late bedtimes (OR=1.82, 95%CI=1.66-1.98) and wake-up times (OR=1.55, 95%CI=1.44-1.68), more sedentary behaviors (OR=1.21, 95%CI=1.12-1.31), less moderate to vigorous physical activity (OR=1.33, 95%CI=1.22-1.44), anxiety (OR=2.98, 95%CI=2.52-3.40), weight gain(OR=1.27，95%CI=1.17-1.37) and other detrimental daily behavior and feelings. Conclusion High prevalence of smartphone addiction has been observed during the COVID-19 pandemic, with impaired daily behavior and mental health.

The newly emerged Middle East respiratory syndrome coronavirus (MERS-CoV) is a highly pathogenic respiratory virus with pathogenic mechanisms that may be driven by innate immune pathways. The goal of this study is to characterize the expression of the structural (S, E, M, N) and accessory (ORF 3, ORF 4a, ORF 4b, ORF 5) proteins of MERS-CoV and to determine whether any of these proteins acts as an interferon antagonist. Individual structural and accessory protein-coding plasmids with an N-terminal HA tag were constructed and transiently transfected into cells, and their native expression and subcellular localization were assessed using Wes tern blotting and indirect immunofluorescence. While ORF 4b demonstrated majorly nuclear localization, all of the other proteins demonstrated cytoplasmic localization. In addition, for the first time, our experiments revealed that the M, ORF 4a, ORF 4b, and ORF 5 proteins are potent interferon antagonists. Further examination revealed that the ORF 4a protein of MERS-CoV has the most potential to counteract the antiviral effects of IFN via the inhibition of both the interferon production (IFN-β promoter activity, IRF-3/7 and NF-κB activation) and ISRE promoter element signaling pathways. Together, our results provide new insights into the function and pathogenic role of the structural and accessory proteins of MERS-CoV.
Cell Line ; Coronavirus ; genetics ; pathogenicity ; Genes, Viral ; Humans ; Interferons ; antagonists & inhibitors ; Open Reading Frames ; Recombinant Proteins ; genetics ; metabolism ; Viral Matrix Proteins ; genetics ; metabolism ; Viral Regulatory and Accessory Proteins ; genetics ; metabolism ; Viral Structural Proteins ; genetics ; metabolism

Objective:To evaluate the in vitro cross-neutralization of serum antibodies in human and mice immunized with inactivated SARS-CoV-2 vaccine against Delta and Beta variants. Methods:Human serum samples after a second and a third dose of inactivated SARS-CoV-2 vaccine and mouse serum samples after a two-dose vaccination were collected. The neutralizing antibodies in the samples against SARS-CoV-2 strains of prototype, Delta and Beta variants were detected using micro-neutralization assay in biosafety level Ⅲ laboratory. The seroconversion rates and geometric mean titers (GMTs) of antibodies were calculated.Results:The seroconversion rates of antibodies in human serum samples against different SARS-CoV-2 strains were all above 95%. After two-dose vaccination, the GMTs of neutralizing antibodies against the prototype, Delta and Beta strains were 109, 41 and 15, respectively. The GMTs decreased by 2.7 folds and 7.3 folds for the Delta and Beta variants as compared with the prototype strain. After the booster vaccination, the GMTs of neutralizing antibodies against the prototype, Delta and Beta strains were 446, 190 and 86, respectively. The GMTs of neutralizing antibodies against Delta and Beta variants decreased by 2.3 folds and 5.2 folds as compared with that against the prototype strain. The seroconversion rates of antibodies against different SARS-CoV-2 strains in mouse serum samples were all 100%. The GMTs of neutralizing antibodies against the prototype, Delta and Beta strains were 2 037, 862 and 408, respectively. The GMTs decreased by 2.4 folds and 5.0 folds for the Delta and Beta variants.Conclusions:Inactivated SARS-CoV-2 vaccine could induce a certain level of neutralizing antibodies against Delta and Beta variants in both human and mouse models. Moreover, a third dose of vaccine induced higher levels of neutralizing antibodies against Delta and Beta variants in human. This study provided valuable data for the clinical application and protective evaluation of the inactivated SARS-CoV-2 vaccine.

Objective: To explore the association between light intensity physical activity (LPA) and sedentary behavior (SB) with body composition, so as to provide data references for improving adolescent physical health. Methods: From August 2020 to January 2021, general information of 694 students in grade one of a high school in Foshan City was collected, and the 24 hour activity behavior and body composition of the students were measured objectively by triaxial accelerometer and bioelectrical impedance tester. Dual component multivariate regression and dual compositional isotemporal substitution model were used to explore the relationship between LPA and SB and body composition. Results: LPA was associated with lower fat relative dominance (FRD) (male weekends FRD=-21.44%, female weekly FRD=-17.83%, weekdays FRD=-18.27%, P <0.05), and LPA was also associated with higher muscle relative dominance (MRD) and bone relative dominance (BRD) (male weekends MRD=12.78%, BRD= 12.87 %; female weekly MRD=11.64%, BRD=9.01%; female weekdays MRD=12.02%, BRD=9.23%, P <0.05). Replacing sedentary behavior (SB) with 10 minutes of LPA could reduce fat proportion [male:weekly -0.15(-0.26--0.04), weekdays -0.12 (-0.22--0.02); female:weekly -0.18(-0.27--0.08), weekdays -0.16(-0.25--0.07)) and increase muscle proportion (male:weekly 0.14(0.03-0.24), weekdays 0.11(0.02-0.21); female:weekly 0.17(0.07-0.26), weekdays 0.15(0.07-0.24)]. Conclusion Interrupting continuous SB with LPA can serve as an intervention measure to promote physical health and fitness in adolescents. School should encourage students to engage in frequent LPA during breaks and after school activities, while avoiding prolonged SB.

Objective:To evaluate the immunogenicity of a novel influenza virus mRNA vaccine based on conserved antigens delivered by lipopolyplex (LPP) platform in a mouse model.Methods:Four copies of genes coding for extracellular domain of matrix 2 protein (M2e) and nucleoprotein (NP) of influenza A virus were synthetized after codon optimization. The fusion antigens were transcribed in vitro and delivered by LPP platform, named as LPP-4M2eNP. Expression of M2e and NP in eukaryotic cells was detected by immunofluorescence assay (IFA). BALB/c mice were inoculated intramuscularly twice with 10 μg or 30 μg LPP-4M2eNP vaccine at an interval of four weeks. Antibody response was detected by ELISA and cellular-mediated immunity (CMI) was detected by enzyme-linked immunospot assay (ELISPOT). Results:IFA showed that NP and M2e were expressed correctly in eukaryotic cells. Single dose immunization could induce significant antigen (NP, M2e)-specific CMI and antigen (NP, M2e)-specific antibody response was induced in mice with Th1 type bias after boost immunization. Moreover, NP-specific CMI was increased significantly after the second immunization, while no significant change in M2e-specific CMI was observed.Conclusions:Stronger CMI was triggered in mice by single dose of LPP-4M2eNP vaccine. Furthermore, robust humoral and cellular immune responses were induced after boost immunization. This study suggested that LPP-4M2eNP vaccine, which based on conserved antigen of influenza A and delivered by LPP platform, had great potential for development and application.

Objective:To evaluate the performance of two commercial EIA kits for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing antibodies.Methods:Two commercial SARS-CoV-2 neutralizing antibody ELISA test kits (A and B) were used to detect serum panel consists of the following sera: 44 collected before vaccination, 120 collected one month after vaccination and 64 collected six months after recovery from convalescent patients of COVID-19. In the meantime, the above samples were also taken for live virus micro-neutralization test (micro-NT) indicated as the 50% neutralization antibody titer (NT 50). The consistency of qualitative and quantitative results between the two commercial kits and live virus neutralization test was analyzed. Results:Taking the micro-NT results as the standard, the positive coincidence rates of A and B kits were 97.40% and 100.00%, respectively; the negative coincidence rates were 97.30% and 95.95%, respectively; the Youden indices were 0.95 and 0.96, respectively. Furthermore, quantitative analysis indicated that the correlation coefficients between A and B kits and micro-NT results were 0.24 ( P<0.05) and 0.52 ( P<0.000 1) for samples collected after vaccination, respectively; while the correlation coefficients were 0.81 ( P<0.000 1) and 0.89 ( P<0.000 1) for convalescent serum samples, respectively. Conclusions:The results obtained by the two commercial neutralizing antibody detection kits were in good agreement with the qualitative results of micro-NT. The neutralizing antibody titers in convalescent serum samples detected by the two kits showed a stronger correlation with the micro-NT results.