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.

Objective: To investigate the characteristics and risk factors of an outbreak of acute hemorrhagic conjunctivitis (AHC) in a boarding middle school in Guangdong Province, in order to provide a scientific evidence for effective prevention and control of campus AHC outbreaks. Methods: From September 1st to 28th 2023, case identification was conducted among 559 students and 60 faculty members using standardized definition. Descriptive analysis was conducted on the three distrubution patterns of the outbreak. Questionnaires were designed, and a case-control study was adopted to analyze the possible risk factors of the disease transmission. The propensity score matching (PSM) method was used to control the difference of baseline data. Results: A total of 269 cases of AHC were identified, with an attack rate of 43.46%. The pathogen was confirmed as Coxsackie virus A24 variant (CA24v). Among these, 264 cases were students (attack rate of 47.23%) and 5 were staff (attack rate of 8.33%). A total of 153 pairs of PSM were successfully matched. After PSM matching, there were no statistically significant differences in gender, grade and class between the case group and the control group ( χ 2=0.12, 5.41, 11.24, P >0.05). The results of multivariate Logistic regression analysis showed that middle school students whose towels contacted with others ( OR =1.81), and direct contact with other AHC cases recently ( OR =4.89) were more likely to have AHC; while wearing glasses ( OR =0.43) and frequent use of hand sanitizer ( OR = 0.37 ) were less likely to have AHC ( P <0.05). Conclusion The outbreak of AHC is caused by CA24v, demonstrating rapid spread and extensive impact within the school setting.

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 explore whether 5/6 nephrectomy can establish a rat model of chronic renal failure-in-duced sarcopenia.Methods The rats were randomly divided into control group,sham operation group and 5/6 ne-phrectomy model group.Chronic renal failure and sarcopenia were further verified.Results Compared with the sham group:① In the model group,the qualitative analysis of urinary protein,serum creatinine,blood urea nitrogen and serum uric acid levels were increased(P＜0.05);② In the model group,the degree of renal fibrosis and the rate of apoptosis were high(P＜0.05);③ In the model group,the muscle strength and function declined(P＜0.05);④ In the model group,the degree of muscle fibrosis was obvious(P＜0.05).Conclusion Through the 5/6 nephrectomy method,an animal model of chronic renal failure-induced sarcopenia can be established,which provides an experimental basis for further prevention and treatment of this disease.

This paper took the"see your life story"-volunteer service project of the cancer patient care program of the First Affiliated Hospital of Guangzhou Medical University as an example,and explored the application of life narrative in the care service of cancer patients.The project adopted the multi-dimensional volunteer service model of"doctors and nurses+volunteers+social workers+patient friends",used the life narrative method,and guided the three groups of cancer patients,patient caregivers,and oncology medical staff to tell their life stories through medical volunteers.Finally,these life stories were delivered in diversified ways,such as physical picture books,interview stories,and sharing meetings.The connection between patients can be promoted in the form of sharing,so that patients and caregivers can get support,and truly achieve to impact life with life.This paper selected the cases in life story books,deeply analyzed the important role of life narrative in promoting the physical and mental recovery of cancer patients,as well as provided reference suggestions for improving patients'medical experience and promoting the cultural development of public hospitals.

Objective To compare clinical effect between open reduction and fixation with cannulated screw and threaded rivet via posteromedial approach versus arthroscopic Endobutton plate fixation in treating posterior cruciate ligament avulsion fractures.Methods Clinical data of 38 patients with posterior cruciate ligament avulsion fractures from July 2020 to December 2021 were analyzed retrospectively,and divided into open reduction and internal fixation group(posterior medial approach hollow anchor system fixation)and arthroscopic fixation group(Endobutton with loop plate fixation under arthroscopy).There were 20 patients in open reduction and internal fixation group,including 16 males and 4 females,aged from 26 to 74 years old with an average of(42.9±18.8)years old;13 patients on the left side and 7 patients on the right side;12 patients were classi-fied to type Ⅱ and 8 patiens with type Ⅲ according to Meyers-McKeever fractures classification;14 patients were grade Ⅱ and 6 patients were grade Ⅲ in back drawer test.There were 18 patients in arthroscopic fixation group,including 11 males and 7 fe-males;aged from 24 to 70 years old with an average of(53.5±13.4)years old;11 patients on the left side and 7 patients on the right side;10 patients were classified to type Ⅱ and 8 patiens with type Ⅲ according to Meyers-McKeever fractures classifica-tion;11 patients were grade Ⅱ and 7 patients were grade Ⅲ in back drawer test.Operation time,blood loss,and quality of im-mediate reduction were compared between two groups.Knee range of motion,knee back drawer test,and International Knee Documentation Committee(IKDC)grading,KT2000 stability evaluation and Lysholm function score of knee joint were com-pared at 6 months after operation.Results All patients were followed up for 8 to 16 months with an average of(12.3±1.9)months.There were no complications such as incision infection,fracture malunion or non-union,and internal fixation loosening occurred.The avulsion fractures of knee joint were reached to imaging healing standard at 6 months after operation.Operation time and blood loss in open reduction and internal fixation group were(56.4±7.1)min and(63.2±10.2)ml,while(89.9±7.4)min and(27.7±8.7)ml in arthroscopic fixation group,respectively,and had significant difference between two groups(P＜0.05).There were no differences in immediate reduction quality(x2=0.257,P=0.612),knee joint range of motion at 6 months after opertaion(t=0.492,P=0.626),knee joint rear drawer test(x2=0.320,P=0.572),IKDC classification of knee joint(x2=0.127,P=0.938),KT2000stability evaluation(x2=0.070,P=0.791),and knee Lysholmfunction score(t=0.092,P=0.282)between two groups.Conclusion Posterior medial approach with hollow anchoring system fixation and arthroscopic Endobutton with loop plate fixa-tion for the treatment of posterior cruciate ligament tibial occlusion avulsion fracture could achieve satisfactory clinical results,and arthroscopic surgery has less bleeding,but also has a longer learning curve and longer operation time than traditional inci-sion surgery.The surgeon needs to make a choice according to clinical situation of patient and their own surgical inclination.

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 forecast the national nursing human resources situation and provide policy basis for promoting the development of the nurse team.Methods The registered nurse numbers,the total population,the registered(assistant)physician numbers,and the bed numbers in medical and health institutions(in thousands)were selected from 2013 to 2023,and the bed-to-nurse ratio,doctor-to-nurse ratio,and the number of nurses per thousand population were calculated and analyzed to study the changes in national nursing human resources over the past decade.A grey GM(1,1)model was established to predict the number of nurses per thousand population from 2024 to 2030.Results ① The number of nurses per thousand population has increased year by year in the past decade,with an average annual growth rate of 11.38％;② The precision of the grey GM(1,1)model for the number of nurses per thousand population is precise(α=-0.065 9,b=2.014 1,C value=0.003 3,P=1.000),with high fitting degree.And the predicted number of registered nurses per thousand population from 2024 to 2030 are 4.291,4.584,4.896,5.229,5.585,5.965,and 6.371 respectively.Conclusion The national nursing human resources allocation has been optimized in the past decade,and the GM(1,1)model predicts that the national nursing human resources change is also in an upward trend.However,relevant policies still need to be formulated to improve the bed-to-nurse ratio and doctor-to-nurse ratio.