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

Objectives:Comparative analysis of the beagles acute-phase electrocardiographic,hemodynamic,left ventricular flow field status,and energy consumption characteristics of pacing at different sites of conduction system may help to elucidate the scientific mechanism of left bundle branch pacing(LBBP)as a option of physiological pacing therapy.Methods:Eight healthy adult beagles were used in this study.Initially,an active fixation lead was implanted in the right atrial appendage,followed by implantation of another active fixation lead at the right ventricular apex,distal His bundle,and left bundle septal branch,respectively.After connecting a dual-chamber pacemaker,electrocardiographic and acute phase hemodynamic parameters under sinus rhythm,right ventricular apex pacing(RVAP),distal His bundle pacing(DHBP),and LBBP states were collected and analyzed.Three complete cardiac cycles of standard apical three-chamber color Doppler dynamic images were acquired under vector flow mapping(VFM)mode.Offline analysis was performed on obtained parameters including isovolumic contraction period,rapid ejection period,isovolumic relaxation period,rapid filling period,atrial contraction period,and left ventricular intracavitary energy consumption.These parameters were compared under pacing at different sites and the linear correlations of major parameters were analyzed.Results:The QRS duration of baseline intrinsic sinus rhythm,RVAP,DHBP and LBBP were(45.0±4.0)ms,(98.4±6.2)ms,(50.0±4.5)ms and(62.0±4.7)ms,respectively.The LBBP-QRS duration was significantly wider than intrinsic sinus rhythm and DHBP,but significantly narrower than RVAP(all P<0.01).Compared with baseline AOO mode(the pacing rate was performed at 10 beats/min above the intrinsic heart rate),the change of acute phase maximum left ventricular pressure rise rate(LVdP/dtmax)in RVAP,DHBP and LBBP was([-7.89±5.67]% ),([0.74±2.05]% )and([-0.14±3.59]% ),respectively.There was no significant difference in LVdP/dtmax changes between DHBP and LBBP(P=0.667),but both pacing modalities were significantly better than RVAP(all P<0.01).The average energy consumption of the left ventricle under RVAP was significantly higher than that of intrinsic sinus rhythm,DHBP,and LBBP in isovolumic contraction period,rapid ejection period,isovolumic relaxation period,rapid filling period,and atrial contraction period(all P<0.01).However,there was no statistically significant difference in energy consumption among intrinsic sinus rhythm,DHBP,and LBBP during the above five phases(all P>0.05).DHBP and LBBP did not show a significant increase in the number of left ventricular vortices,vortex area,and circulation intensity compared to intrinsic sinus rhythm,and LBBP did not show a significant increase in vortex area and circulation intensity compared to DHBP.Conclusions:Although LBBP canines significantly prolonged the paced QRS duration,it showed no significant differences in acute phase left ventricular hemodynamics,left ventricular flow field status,and energy consumption compared to intrinsic sinus rhythm and DHBP.Performance of LBBP was superior to RVAP.This study may contribute to revealing the theoretical basis of LBBP as a feasible physiological pacing therapy.

Objectives:Comparative analysis of the beagles acute-phase electrocardiographic,hemodynamic,left ventricular flow field status,and energy consumption characteristics of pacing at different sites of conduction system may help to elucidate the scientific mechanism of left bundle branch pacing(LBBP)as a option of physiological pacing therapy.Methods:Eight healthy adult beagles were used in this study.Initially,an active fixation lead was implanted in the right atrial appendage,followed by implantation of another active fixation lead at the right ventricular apex,distal His bundle,and left bundle septal branch,respectively.After connecting a dual-chamber pacemaker,electrocardiographic and acute phase hemodynamic parameters under sinus rhythm,right ventricular apex pacing(RVAP),distal His bundle pacing(DHBP),and LBBP states were collected and analyzed.Three complete cardiac cycles of standard apical three-chamber color Doppler dynamic images were acquired under vector flow mapping(VFM)mode.Offline analysis was performed on obtained parameters including isovolumic contraction period,rapid ejection period,isovolumic relaxation period,rapid filling period,atrial contraction period,and left ventricular intracavitary energy consumption.These parameters were compared under pacing at different sites and the linear correlations of major parameters were analyzed.Results:The QRS duration of baseline intrinsic sinus rhythm,RVAP,DHBP and LBBP were(45.0±4.0)ms,(98.4±6.2)ms,(50.0±4.5)ms and(62.0±4.7)ms,respectively.The LBBP-QRS duration was significantly wider than intrinsic sinus rhythm and DHBP,but significantly narrower than RVAP(all P<0.01).Compared with baseline AOO mode(the pacing rate was performed at 10 beats/min above the intrinsic heart rate),the change of acute phase maximum left ventricular pressure rise rate(LVdP/dtmax)in RVAP,DHBP and LBBP was([-7.89±5.67]% ),([0.74±2.05]% )and([-0.14±3.59]% ),respectively.There was no significant difference in LVdP/dtmax changes between DHBP and LBBP(P=0.667),but both pacing modalities were significantly better than RVAP(all P<0.01).The average energy consumption of the left ventricle under RVAP was significantly higher than that of intrinsic sinus rhythm,DHBP,and LBBP in isovolumic contraction period,rapid ejection period,isovolumic relaxation period,rapid filling period,and atrial contraction period(all P<0.01).However,there was no statistically significant difference in energy consumption among intrinsic sinus rhythm,DHBP,and LBBP during the above five phases(all P>0.05).DHBP and LBBP did not show a significant increase in the number of left ventricular vortices,vortex area,and circulation intensity compared to intrinsic sinus rhythm,and LBBP did not show a significant increase in vortex area and circulation intensity compared to DHBP.Conclusions:Although LBBP canines significantly prolonged the paced QRS duration,it showed no significant differences in acute phase left ventricular hemodynamics,left ventricular flow field status,and energy consumption compared to intrinsic sinus rhythm and DHBP.Performance of LBBP was superior to RVAP.This study may contribute to revealing the theoretical basis of LBBP as a feasible physiological pacing therapy.

Objective:To establish venetoclax-resistant acute myeloid leukemia(AML)cell lines,assess the sensitivity of venetoclax-resistant cell lines to the BCL-2 protein family,and investigate their resistance mechanisms.Methods:CCK-8 method was used to screen AML cell lines(MV4-11,MOLM13,OCI-AML2)that were relatively sensitive to venetoclax.Low concentrations of venetoclax continuously induced drug-resistance development in the cell lines.Changes in cell viability and apoptosis rate before and after resistance development were measured using the CCK-8 method and flow cytometry.BH3 profiling assay was performed to anayze the transform of mitochondrion-dependent apoptosis pathway as well as the sensitivity of resistant cell lines to BCL-2 family proteins and small molecule inhibitors.Real-time fluorescence quantitative PCR(RT-qPCR)was utilized to examine changes in the expression levels of BCL-2 protein family members in both venetoclax-resistant cell lines and multidrug-resistant patients.Results:Venetoclax-resistant cell lines of MV4-11,MOLM13,and OCI-AML2 were successfully established,with IC50 values exceeding 10-fold.Under the same concentration of venetoclax,the apoptosis rate of resistant cells decreased significantly(P＜0.05).BH3 profiling assay revealed that the drug-resistant cell lines showed increased sensitivity to many pro-apoptotic proteins(such as BIM,BID and NOXA).RT-qPCR showed significantly upregulated MCL1 and downregulated NOXA1 were detected in drug-resistant cell lines.Expression changes in MCL1 and NOXA1 in venetoclax-resistant patients were consistent with our established drug-resistant cell line results.Conclusion:The venetoclax-resistant AML cell lines were successfully established through continuous induction with low concentrations of venetoclax.The venetoclax resistance resulted in alterations in the mitochondrial apoptosis pathway of the cells and an increased sensitivity of cells to pro-apoptotic proteins BIM,BID,and NOXA,which may be associated with the upregulation of MCL1 expression and downregulation of NOXA1 expression in the drug-resistant cells.

Objective:To evaluate the effect of low-dose recombinant interleukin-2(rIL-2)therapy on immunocyte subsets and its side effects in children with solid tumor.Methods:A total of 22 children(11 males and 11 females)with solid tumor in our department from December 2012 to November 2017 were selected,with a median age of 9(3-16)years old when starting IL-2 therapy.ALL surgeries and chemotherapy of children had been completed before low-dose rIL-2 therapy,and 17 cases achieved complete remission(CR)and 5 cases achieved partial remission(PR).A low-dose rIL-2 therapy was given 1 month after chemotherapy for 1 year:4 × 105 IU/(m2·d),s.c.for every other day,3 times per week.The immunocyte subsets were detected every 3 months until the end of treatment,meanwhile,disease condition and therapy-related side effects were followed up.Results:After low-dose rIL-2 therapy in 22 children,the absolute values of CD3+T cells,CD3-CD56+natural killer cells,CD3+CD4+helper T cells(Th)and CD3+CD8+cytotoxic T cells were up-regulated remarkably,as well as Th/suppressor T cells(all P＜0.05).While,there were no significant differences in absolute value and proportion of CD4+CD25+CD127-Treg cells during therapy.Among the 17 children who achieved CR before rIL-2 therapy,14 cases continued to maintain CR after therapy,while 3 cases relapsed,and with 2 died after treatment abandonment.The 5 children who achieved PR before low-dose rIL-2 therapy were evaluated CR by PET/CT scan after treatment.In the early stage of low-dose rIL-2 therapy,1 child developed skin rashes at the injection sites,and 2 children ran a slight to mild transient fever.Their symptoms disappeared without any organ damage after symptomatic treatment.Conclusion:Low-dose rIL-2 therapy has good drug tolerance,and changes the distribution of anti-tumor immune-cell subgroup in peripheral blood of children with solid tumor remarkably without up-regulation of absolute value and ratio of Treg cells.

Objective:To screen interleukin(IL)-1β secretion-related membrane transporters by macrophage experiment in vitro and conventional knockout mice.Methods:THP-1 cell line was differentiated to obtain human THP-1-derived macrophages,and the primary macrophages were obtained from human peripheral blood.FVB wild-type mice with the same sex and age were used as the controls of MRP1 knockout mice.The macrophages in abdominal cavity and bone marrow of mice were cultivated.The cells were treated with ABCC1/MRP1,ABCG2/BCRP,ABCB1/P-gp,OATP1B1,and MATE transporter inhibitors,then stimulated by lipopolysaccharide and adenosine triphosphate.The secretion level of IL-iβ was detected by ELISA,Western blot,and immunofluorescence.Results:After inhibiting ABCC1/MRP1 transporter,the secretion of IL-1β decreased significantly,while inhibition of the other 4 transporters had no effect.In animal experiment,the level of IL-1 β secreted by macrophages in bone marrow of MRP1 knockout mice was significantly lower than control group(P＜0.05).Conclusion:ABCC1/MRP1 transporter is a newly discovered IL-1β secretion pathway,which is expected to become a new target for solving clinical problems such as cytokine release syndrome.

Objective:To investigate the factors contributing to frailty in very elderly patients with multimorbidity.Methods:This cross-sectional study enrolled 119 very elderly patients with multimorbidity who were hospitalized in the Department of Geriatrics of Huadong Hospital Affiliated to Fudan University from August 2022 to March 2023.The study aimed to understand the basic status of multimorbidity by collecting general information, the number and types of diseases, and frailty status.The subjects were divided into frail and non-frail groups through comprehensive geriatric assessment.Various factors including gender, age, Tinetti balance gait score, risk of sarcopenia, dementia, depression, risk of deep vein thrombosis, dysphagia, comorbidity index, medication count, Basic Activities of Daily Living(BADL)score, Instrumental Activities of Daily Living(IADL)score, Nutritional Risk Screening 2002(NRS-2002)score, Norton pressure injury risk assessment score, and Social Support Rating Scale(SSRS)score were compared.The correlation between each factor and the occurrence of frailty was analyzed using univariate analysis and multivariate Logistic regression analysis.Results:A total of 119 elderly inpatients with multimorbidity, with an average age of 90.8±5.9 years old, were included in the study.The incidence of frailty was 68.9%(82 cases).Univariate analysis revealed significant statistical differences between the frail group and the non-frail group in various factors including age( t=-3.131, P=0.002), Tinetti score( Z=-5.544, P<0.001), risk of sarcopenia( χ2=39.205, P<0.001), dysphagia( χ2=5.937, P=0.015), Charlson comorbidity index( Z=-2.565, P=0.010), medication count( Z=-3.325, P<0.001), BADL( Z=-5.871, P<0.001), IADL( Z=-5.062, P<0.001), Norton score( Z=-5.922, P<0.001), and SSRS social support( Z=-2.637, P=0.008).Multivariate logistic regression analysis showed that the Tinetti score( OR=0.843, 95% CI: 0.737-0.966, P=0.014), decreased muscle strength( OR=11.226, 95% CI: 2.157-58.432, P=0.004), sarcopenia( OR=18.084, 95% CI: 2.041-106.211, P=0.009), Norton score( OR=0.462, 95% CI: 0.254-0.838, P=0.011), and medication count( OR=1.153, 95% CI: 1.000-1.329, P=0.049)were independently associated with frailty. Conclusions:In very elderly patients with multimorbidities, the occurrence of frailty is notably increased.Frailty is linked to multiple risks including falls, muscle weakness/sarcopenia, pressure ulcer risk, and polypharmacy, and these risks are independent of other factors.

Objective To observe the clinical efficacy of compound Wufengcao liquid combined with negative pressure wound therapy with instillation(NPWTi)for the treatment of stage Ⅲ-Ⅳ pressure injury(PI),and to preliminarily explore its action mechanism.Methods(1)Clinical research:from January 2019 to October 2022,60 PI patients who were admitted to the Scrofula Department and Wound Care Clinic at Nanjing Municipal Hospital of Traditional Chinese and Western Medicine were randomly divided into normal saline NPWTi group and compound Wufengcao liquid NPWTi group,with 30 cases in each group.Both groups underwent NPWTi under the premise of systemic basic treatment,before treatment,after removing the negative pressure device in the 1st,2nd and 3rd weeks of treatment,the pressure ulcer scale for healing(PUSH)score,the wound bacterial culture detection rate and the wound healing time were counted,and the vascular endothelial growth factor(VEGF)content of wound tissue was detected by ELISA method.(2)Animal experiments:24 SD rats were randomly divided into blank group,model group,normal saline NPWTi group and compound Wufengcao liquid NPWTi group,6 rats in each group.PI rat model was established by local tissue ischemia/reperfusion injury method,and the negative pressure device was removed at the end of each day of treatment.Before treatment and 3,7 and 10 days after treatment,the wound morphology of each group of rats was observed,the wound histopathology was observed by HE staining,the CD34 positive cells rate of wound tissue was detected by immunohistochemistry,and the expressions of p38 mitogen-activated protein kinase(p38 MAPK),nuclear factor-κB p65(NF-κB p65),inducible nitric oxide synthase(iNOS),tumor necrosis factor-α(TNF-α),arginase-1(Arg-1)and transforming growth factor-β(TGF-β)in rat blood and wound tissue were detected by ELISA and RT-qPCR.Results(1)Clinical research:Both groups could effectively reduce the PUSH score and the wound bacterial culture detection rate,shorten the wound healing time,and promote the expression of VEGF in wound tissue,the compound Wufengcao liquid NPWTi group was better than the normal saline NPWTi group(P<0.05).(2)Animal experiments:Compared with blank group,the rats in the model group showed obvious wound inflammatory response and tissue damage,and the CD34 positive cells rate,blood and wound tissue p38 MAPK,NF-κB p65,iNOS and TNF-α levels were significantly increased,Arg-1 and TGF-β level was significantly reduced(P<0.05);Compared with model group,after 7 days of treatment,the normal saline NPWTi group and the compound Wufengcao liquid NPWTi group significantly decreased the wound morphology score,the histopathological morphology was significantly improved,the CD34 positive cells rate was significantly increased(P<0.05),the levels of blood and wound tissue p38 MAPK,NF-κB p65,iNOS,and TNF-α were significantly reduced,and the levels of Arg-1 and TGF-β were significantly increased(P<0.05),and the compound Wufengcao liquid NPWTi group was better than that of the normal saline NPWTi group(P<0.05).Conclusion Compound Wufengcao liquid combined with NPWTi can effectively promote the healing of PI wounds,and its mechanism of action may be by inhibiting the activation and expression of p38 MAPK/NF-κB signaling pathway,thereby regulating the polarization balance of M1/M2 macrophages.

Objective:To evaluate the diagnostic accuracy of the convolutional neural network（CNN） in diagnosing nasopharyngeal carcinoma using endoscopic narrowband imaging. Methods:A total of 834 cases with nasopharyngeal lesions were collected from the People's Hospital of Guangxi Zhuang Autonomous Region between 2014 and 2016. We trained the DenseNet201 model to classify the endoscopic images, evaluated its performance using the test dataset, and compared the results with those of two independent endoscopic experts. Results:The area under the ROC curve of the CNN in diagnosing nasopharyngeal carcinoma was 0.98. The sensitivity and specificity of the CNN were 91.90% and 94.69%, respectively. The sensitivity of the two expert-based assessment was 92.08% and 91.06%, respectively, and the specificity was 95.58% and 92.79%, respectively. There was no significant difference between the diagnostic accuracy of CNN and the expert-based assessment （P=0.282, P=0.085）. Moreover, there was no significant difference in the accuracy in discriminating early-stage and late-stage nasopharyngeal carcinoma（P=0.382）. The CNN model could rapidly distinguish nasopharyngeal carcinoma from benign lesions, with an image recognition time of 0.1 s/piece. Conclusion:The CNN model can quickly distinguish nasopharyngeal carcinoma from benign nasopharyngeal lesions, which can aid endoscopists in diagnosing nasopharyngeal lesions and reduce the rate of nasopharyngeal biopsy.
Humans ; Nasopharyngeal Carcinoma ; Narrow Band Imaging ; China ; Neural Networks, Computer ; Nasopharyngeal Neoplasms/diagnostic imaging*

Objective:To understand the current situation of nurses in 52 hospitals in China on mastery of knowledge about skin injury in the elderly based on the background of mixed-mode homogenization training.Methods:Using the convenient sampling method, a total of 1 067 nurses from 52 hospitals in China were selected as the research objects in January 2021. A self-designed questionnaire on knowledge of skin injury in the elderly was used to investigate the nurses through the questionnaire star and univariate analysis was used to analyze the influencing factors. A total of 1 067 questionnaires were distributed and 1 067 valid questionnaires were recovered, and the effective recovery rate was 100%.Results:The knowledge scores of pressure injury, incontinence-associated dermatitis, skin tear and xerosis cutis among 1067 nurses were (95.66±7.37) , (95.65±9.15) , (91.37±15.45) and (87.67±15.91) , respectively. The results of univariate analysis showed that hospital grade was the influencing factor of nurses' knowledge score of pressure injury, skin tear and incontinence-associated dermatitis ( P<0.05) , educational background was the influencing factor of nurses' knowledge score of skin tear ( P<0.05) , professional title was the influencing factor of nurses' knowledge scores of pressure injury, incontinence-associated dermatitis and xerosis cutis ( P<0.05) . Conclusions:Hospitals at all levels need to strengthen the theoretical and practical knowledge training for nurses on skin xerosis and skin tear in the elderly, especially for nurses with primary titles and lower education in grassroots hospitals.