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.

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 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 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.