Objective The study aims to investigate the immunological functions of the nucleocapsid (N) protein of the novel coronavirus Omicron (BA.1, BA.2) and evaluate the differences among different N proteins of mutant strains in immunogenicity. Methods By aligning sequences, the mutation sites of the Omicron (BA.1, BA.2) N protein relative to prototype strain of the novel coronavirus (Wuhan-Hu-1) were determined. The pET-28a-N-Wuhan-Hu-1 plasmid was used as template to construct pET-28a-BA.1/BA.2-N through single point mutation or homologous recombination. The three kinds of N protein were expressed in prokaryotic system, purified through Ni-NTA affinity chromatography, and then immunized into mice. The titer and reactivity of the polyclonal antibody, as well as the expression level of IL-1β and IFN-γ in mouse spleen cells, were detected using indirect ELISA and Western blot assay. Results The constructed prokaryotic expression plasmids were successfully used to express the Wuhan-Hu-1 N, BA.1 N, and BA.2 N proteins in E.coli BL21(DE3) at 37 DegreesCelsius for 4 hours. The indirect ELISA test showed that the titers of polyclonal antibody prepared by three N proteins were all 1:51 200. All three N proteins can increase the expression of IFN-γ and IL-1β cytokines, but the effect of Omicron N protein in activing two cytokines was more obvious than that of Wuhan-Hu-1 N protein. Conclusion The study obtained three new coronavirus N proteins and polyclonal antibodies, and confirmed that mutations in the amino acid sites of the N protein can affect its immunogenicity. This provides a basis for developing rapid diagnostic methods targeting N protein of different novel coronavirus variants.
Animals ; Mice ; SARS-CoV-2/genetics* ; Coronavirus Nucleocapsid Proteins/immunology* ; Nucleocapsid Proteins/isolation & purification* ; COVID-19/immunology* ; Antibodies, Viral/immunology* ; Mice, Inbred BALB C ; Interferon-gamma/metabolism* ; Interleukin-1beta/metabolism* ; Female ; Escherichia coli/metabolism* ; Mutation ; Humans

AIM To investigate the promotional effects of esculin combined with bone marrow mesenchymal stem cells(BM-MSCs)transplantation on the repair of spinal cord injury(SCI)in rats.METHODS The rats were randomly divided into the sham operation group,the model group,the esculin group for gavage of 20 mg/kg esculin,the BM-MSCs group for tail vein injection of 1 mL of 1×106/mL BM-MSCs,and the combinaiton treatment group.The SCI rat model was established using Allen's method,followed by the 14 days consecutive corresponding drug administration starting from the 2nd day after modeling.On days 3,7 and 14 of drug administration,the rats had their hind limbs motor function evaluated by the BBB scoring;and their footprint experiment conducted on the 14th day after modeling.After 14 days of administration,the rats had their morphological changes of spinal cord tissue observed with HE staining and Nissl staining;their activities of SOD and GSH,and level of MDA in spinal cord tissue detected by kits;their expressions of MAP2,GAP43 and GFAP in spinal cord tissue detected by immunofluorescence;and their expressions of NQO-1,Nrf-2,Bcl-2 and Bax proteins in spinal cord tissue detected by Western blot.RESULTS Compared with the model group,the groups interved with esculin,or BM-MSCs,or the combination treatment showed improvements in hind limb function and spinal cord tissue morphology(P＜0.05);decreased MDA levels(P＜0.05);increased SOD and GSH activities(P＜0.05);increased MAP2 and GAP43 fluorescence intensity(P＜0.05);decreased GFAP fluorescence intensity(P＜0.05);increased NQO-1,Nrf-2 and Bcl-2 protein expressions(P＜0.05);and decreased Bax protein expression(P＜0.05).And the combination treatment group was observed with an even better effects(P＜0.05).CONCLUSION The combination of esculin and BM-MSCs transplantation can effectively improve the spinal cord tissue damage and hind limb function in SCI rats.This effect may be achieved by activating the Nrf-2/NQO-1 signaling pathway to inhibit oxidative stress response,thereby reducing neuronal apoptosis,blocking glial scar formation,and promoting stem cell differentiation to rebuild neurons.

Objective To evaluate the application of problem-based learning(PBL)and case-based learning(CBL)combined with ideological-political elements in surgical clinical ethics.Methods Eighty graduate students of grade 2022 majoring in surgery from Peking Union Medical College were selected as the subjects for the clinical ethics course offered in the first semester of the 2022-2023 academic year.They underwent the innovative pedago-gies of PBL and CBL combined with ideological-political elements.The satisfaction investigation and questionnaire surveys were performed to evaluate the effects.Results A total of 78 valid questionnaires were received.The results showed that 96.2%of students believed that this course supported them to understand the fundamental prin-ciples and knowledge of surgical clinical ethics and 94.9%of students expressed their willingness to expand their knowledge,indicating high satisfaction with the course.There were 91%of students acknowledged this model in terms of improving active learning and 93.6%stated that the course helped in developing good professional ethics.Most students responded positively to this model because of its contribution to enhance core clinical competencies.Conclusions The PBL and CBL combined with ideological-political elements have a better effect on surgical clini-cal ethics with high satisfaction of the students.

AIM To investigate the repair effects of tauroursodeoxycholic acid(TUDCA)combined with bone marrow mesenchymal stem cells(BMSCs)transplantation on spinal cord injury(SCI)in rats.METHODS The rats were randomly divided into the sham operation group,the model group,the TUDCA group,the BMSCs transplantation group and the combination therapy of TUDCA and BMSCs transplantation group,with the SCI rat model established by Allen's method.The next day after modeling,the rats of TUDCA and combination therapy groups were given 200 mg/kg TUDCA by gavage.On the 3rd day after modeling,rats in BMSCs transplantation group and combination therapy group were injected with 1 mL tuned bone marrow BMSCs(the 3rd generation,1× 106/mL)via tail vein.Rats in the sham operation group and the model group were given gastric perfusion of normal saline and injection of 1 mL PBS through tail vein.On the 3rd,7th and 14th day after modeling,the rats had their motor function of hind limbs observed and BBB score determined.After the corresponding drug administration,the rats had their movement track of hind limbs recorded by footprint experiment;their the protein expressions of IL-6,IL-10,Arg-1,PI3K and Akt in spinal cord tissue detected by Western blot;their pathological changes of spinal cord tissue observed by HE staining and Nissl staining;and their expressions of MAP2,GAP43 and GFAP detected by immunofluorescence staining.RESULTS Compared with the model group,the groups intervened with TUDCA,or BMSCs transplantation,or combination therapy shared improved hind limb function and spinal cord histomorphology(P＜0.05);increased fluorescence intensity of MAP2 and GAP43,and protein expressions of IL-10,Arg-1,p-PI3K and p-Akt(P＜0.05);decreased fluorescence intensity of GFAP and IL-6 protein expressions(P＜0.05);among which the combination therapy group took the lead(P＜0.05).CONCLUSION The combination therapy of TUDCA and BMSCs transplantation may restore the function of the rat model of SCI by reducing inflammatory reaction,alleviating secondary injury,and promoting axon and myelin regeneration via PI3K/Akt signaling pathway.

Objective:To investigate the effects of oral propranolol on the heart rate and blood glucose levels in children with hemangiomas receiving hospital care.Methods:A total of 259 children [77 males and 182 females, aged (125.2±85.4) days, weighted (6.3±1.6) kg], who were treated with oral propranolol for the first time under hospital care from January 2013 to August 2021, were retrospectively analyzed. After fasting, the patients administered the same dose of propranolol once daily (0.5-2.5 mg/kg). Fasting blood glucose and heart rate were measured in all children before propranolol administration and after 2 h. Heart rate was measured at 1, 3 and 6 h after propranolol administration for three consecutive days. Adverse reactions were observed and recorded.Results:Within three days of oral propranolol administration, the heart rates at 1, 3 and 6 h after propranolol administration were lower than those before propranolol administration (all P<0.001). Within three days after taking propranolol and 2 h after taking propranolol daily, blood glucose levels reduced in all children (all P<0.001). During the hospitalization period, the incidence of adverse reactions was 5.4% (14/259), including lesion ulcers in four cases, upper respiratory tract infection with fever in four, reduced eating in two, nausea and vomiting in one, lethargy in one, sinus tachycardia in one, and hyperkalemia in one. No serious adverse reactions were life-threatening. Conclusion:After oral administration of propranolol, the heart rate and blood sugar of the children decrease to different degrees compared with those before propranolol administration.

Objective To explore the potential characteristics of self-management behavior in maintenance hemodialysis patients with hypertension and determine the influencing factors of different characteristics,so as to provide reference for improving self-management behavior.Methods A total of 192 maintenance hemodialysis patients with hypertension who received dialysis in The First Hospital Affiliated to Naval Medical University from May to September 2022 were enrolled by convenience sampling.A general information questionnaire,hypertension self-management behavior scale,Morisky medication adherence scale-8 items,and medication adherence self-efficacy scale-revision(MASES-R)were used to investigate the potential categories of self-management behavior in maintenance hemodialysis patients with hypertension,and the predictive indicators of each category were analyzed by latent profile analysis.Results Three latent categories of self-management behavior in maintenance hemodialysis patients with hypertension were identified:low self-management behavior,moderate self-management behavior,and high self-management behavior.Medication adherence and medication adherence self-efficacy were predictors of high self-management behavior.Monitoring blood pressure once daily was a predictor of moderate self-management behavior.Conclusion There is significant self-management characteristics among maintenance hemodialysis patients with hypertension.These characteristics and risk factors should be identified early to help patients improving their self-management.

Objective To assess the impact of long working hours on sleep disorders among manufacturing workers and explore the roles of alcohol consumption and mental health factors(anxiety and depressive symptoms)in this association.Methods A cross-sectional study design was used to survey 1 336 manufacturing workers in Shenzhen.We collected the data of their demographic characteristics,work-related factors,personal behaviors,sleep disorders,and mental health status.Multivariate Logistic regression analysis was used to assess the association between long working hours and sleep disorders.Stratified analysis and mediation effect models were applied to examine the effect modification by alcohol consumption and the mediating role of mental health factors,respectively.Results Among the study samples,31.8％reported long working hours and 45.6％had sleep disorders.Multivariate Logistic regression analysis showed that long working hours significantly increased the risk of sleep disorders(adjusted OR=2.073,95％ CI:1.478-2.907,P＜0.001).Stratified analysis revealed that the association between long working hours and sleep disorders was more pronounced among alcohol consumers(adjusted OR=2.556,95％ CI:1.432-4.562,P=0.001).Mediation effect analysis showed that anxiety and depressive symptoms partially mediated the relationship between long working hours and sleep disorders,with indirect effects accounting for 25.71％ and 27.14％,respectively.Conclusion Long working hours increase the risk of sleep disorders among manufacturing workers,particularly among those who consume alcohol.Anxiety and depressive symptoms partially explain the association between long working hours and sleep disorders.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.