BACKGROUND:Synthetic polymers,such as polypropylene and polyester,used for the treatment of abdominal wall defects not only lack biodegradability and bioactivity but also fail to meet the demands of complex and irregular wounds.Therefore,finding bioactive materials with low immunogenicity and good histocompatibility has become a hot spot in the repair of abdominal wall defects. OBJECTIVE:To prepare methacryloyl modified dermal extracellular matrix hydrogel and explore its potential application in abdominal wall defect. METHODS:(1)The porcine dermis was acellular with 0.25%trypsin and 1%Triton X-100 in turn to obtain the dermal extracellular matrix.After pepsin digestion and methacrylic anhydride modification,the methacrylated dermal extracellular matrix hydrogel was formed by photocrosslinking.The microscopic morphology of the hydrogel was observed by scanning electron microscope,and its rheological properties,swelling properties and other physical and chemical properties were tested.(2)Mice fibroblasts(L929)were inoculated into methacrylated dermal extracellular matrix hydrogel to detect the cell compatibility.(3)Totally 12 SD rats were randomly divided into two groups(n=6)to create abdominal wall defect model with peritoneum preserved.The defect site of the polypropylene group was filled with polypropylene material,and the hydrogel group was filled with methacrylated dermal extracellular matrix hydrogel.The wound skin of both groups was covered with polypropylene material.The wound healing was observed and histological analysis was carried out. RESULTS AND CONCLUSION:(1)Enzymatic hydrolysis had a good decellularization effect on porcine dermis after decellularization,and the original glycosaminoglycans and collagen were well retained.Scanning electron microscope observation revealed that the dermal extracellular matrix hydrogel presented loose and porous structure.The aperture was between 70 and 120 μm.The swelling ratio was(16.88±3.24)%and the water absorption was(94.24±1.11)%.The rheological property test showed that the methacrylated dermal extracellular matrix hydrogel was stable and had shear thinning characteristics,with injectability.(2)CCK-8 assay and live/dead staining showed that methacrylated dermal extracellular matrix hydrogel had good cell compatibility.(3)The results of animal experiments showed that the skin wound healing rate of the experimental group was higher than that of the control group at 7,10,and 14 days after operation(P<0.05).Hematoxylin-eosin and Masson staining of skin and muscle tissue exhibited that compared with the polypropylene group,the skin wound epithelialization,hair follicle formation,collagen fiber arrangement,and neovascularization were better in the hydrogel group 14 days after surgery.The skin wound new tissue structure was similar to the normal tissue at 28 days after surgery,and scar hyperplasia was less.A small amount of muscle regeneration was observed on day 28 after operation.(4)The results show that the methacrylated dermal extracellular matrix hydrogel can promote wound skin healing and muscle tissue regeneration in rats with abdominal wall defect.

In 2023，World Health Organization（WHO）announced that the pandemic of COVID-19 is over；while there was an epidemic of multi-pathogenic infections in the respiratory tract by the end of the year in China，indicating that high attention still need to be paid to infectious diseases. In the past one year，some breakthroughs for infectious diseases have been achieved.This article reviews the major events and research progress in the diagnosis，prevention and treatment of infectious diseases in 2023.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

【Objective】 To explore the effectiveness and safety of different salvage therapies for local recurrence of tumor following primary prostate cryoablation so as to provide the reference for the treatment of prostate similar cases. 【Methods】 The clinical data of patients with prostate cancer (cT1c-4N0M0) who received salvage therapy for local recurrence of tumor following primary prostate cryoablation in the Sun Yat-Sen University Cancer Center during June 2014 and Dec. 2020 were retrospectively analyzed. Salvage therapies included local therapy (salvage radiotherapy, salvage cryoablation or salvage radical prostatectomy) and androgen deprivation therapy (ADT). 【Results】 Altogether 8 patients were involved. The median age was 71(63-76) years, the median prostate specific antigen (PSA) at the first diagnosis was 17.650(10.380-325.100) ng/mL, the median nadir post-cryoablation PSA was 0.041(0.003-0.541) ng/mL, and the median PSA at local recurrence was 3.030(2.090-19.180) ng/mL. Abnormal digital rectal examination was found in 3 cases, and radiographic evidence of local recurrence was found in 7 cases. Prostate biopsy was performed in 4 cases, 2 of which had positive results. The median follow-up after salvage therapy lasted for 54 (9-75) months. Four cases received salvage radiotherapy, 2 of which developed bloody stool, hematuresis and urinary tract infection, and recovered after conservative treatment; 1 case received salvage cryoablation without side effects; 1 case underwent radical prostatectomy and radiotherapy, developed lymphorrhagia and recovered after conservative treatment; 2 cases received ADT alone, one experienced hot flashes and recovered after conservative treatment, and the other progressed into castration-resistant prostate cancer after 63 months. No other progression or death occurred at the termination of follow-up. 【Conclusion】 Salvase therapy (salvage radiotherapy, salvage cryoablation, salvage radical prostatectomy) and ADT can be used for local recurrence of tumor following primary prostate cryoablation. However, large-scale prospective research is needed to confirm the effectiveness and safety of different therapies.

BACKGROUND:There is controversy regarding the need for marrow reaming in intertrochanteric fractures of the femur.Some believe that unreaming shortens operative time,reduces bleeding,and decreases intraoperative risk in elderly patients,but there is no basis for whether this move reduces the effectiveness of intramedullary nail support.Others believe that reaming allows for the selection of thicker diameter intramedullary nails for better mechanical support,but basic studies have shown that this approach carries risks such as fat embolism and destruction of bone(especially in elderly patients with osteoporosis). OBJECTIVE:To analyze the mechanical distribution characteristics of reamed and unreamed proximal femoral nail antirotation-Ⅱ in the treatment of type 31-A3 intertrochanteric fractures by finite element analysis. METHODS:A healthy volunteer was included,and CT scans of his femur were obtained in DICOM format,and the files were sequentially imported into Mimics,Geomagic Wrap,SolidWorks,Hypermesh,and Ansys software for processing.The A3.1,A3.2,and A3.3 intertrochanteric fracture models were obtained and assembled with 9 mm,11 mm diameter,and 170 mm length intramedullary nails,respectively,followed by assigning material properties,setting the interaction relationship of each contact surface and defining the load and boundary conditions,and then solved.The femoral stress distribution,internal fixation stress distribution,femoral displacement,and internal fixation displacement were observed in different models. RESULTS AND CONCLUSION:(1)The femoral stress was less than that of unreamed intramedullary nail fixation for each type of fracture,and the maximum stress value of the femur for A3.3 fracture was greater than that of A3.1 and A3.2.(2)The internal fixation stress was greater than that of unreamed intramedullary nail fixation for each type of fracture,and the maximum stress value of internal fixation for A3.3 fracture was greater than that of A3.1.(3)Reamed versus unreamed intramedullary nailing has less effect on femoral and internal fixation displacement and more effect on stress.(4)It is indicated that the use of reamed intramedullary nail fixation results in a reduction in femoral stress,an increase in the stress borne by the internal fixation as a whole,and a reduction in the stress borne by the distal locking nail.The use of reamed intramedullary nail fixation may provide better treatment results compared to unreamed intramedullary nail fixation.

Coronavirus disease 2019(COVID-19)has been one of the most concerning public health events in recent years,seriously threatening the lives and health of people worldwide.COVID-19 vaccines are the most cost-effective measure to reduce the influence of severe acute respiratory syndrome coronavirus 2(SARS-COV-2)to the population.Therefore,countries actively develop and vaccinate COVID-19 vaccines,including recombinant protein vaccines,viral vector vaccines,inactivated vaccines,and mRNA vaccines,which occupy the primary market.With the enhancement of variants transmission ability and evasion immunity,the protective effect and durability of COVID-19 vaccines have become the current research hotspots.This paper presents a brief review of the progress of COVID-19 vaccines,intending to provide a reference for the development of COVID-19 vaccines.

Objective:To analyze the factors affecting delayed chemotherapy in children with Burkitt lymphoma (BL) and their influence on prognosis.Methods:Retrospective cohort study. Clinical data of 591 children aged ≤18 years with BL from May 2017 to December 2022 in China Net Childhood Lymphoma (CNCL) was collected. The patients were treated according to the protocol CNCL-BL-2017. According to the clinical characteristics, therapeutic regimen was divided into group A, group B and group C .Based on whether the total chemotherapy time was delayed, patients were divided into two groups: the delayed chemotherapy group and the non-delayed chemotherapy group. Based on the total delayed time of chemotherapy, patients in group C were divided into non-delayed chemotherapy group, 1-7 days delayed group and more than 7 days delayed group. Relationships between delayed chemotherapy and gender, age, tumor lysis syndrome before chemotherapy, bone marrow involvement, disease group (B/C group), serum lactate dehydrogenase (LDH) > 4 times than normal, grade Ⅲ-Ⅳ myelosuppression after chemotherapy, minimal residual disease in the interim assessment, and severe infection (including severe pneumonia, sepsis, meningitis, chickenpox, etc.) were analyzed. Logistic analysis was used to identify the relevant factors. Kaplan-Meier method was used to analyze the patients' survival information. Log-Rank was used for comparison between groups.Results:Among 591 patients, 504 were males and 87 were females, the follow-up time was 34.8 (18.6,50.1) months. The 3-year overall survival (OS) rate was (92.5±1.1)%,and the 3-year event-free survival (EFS) rate was (90.5±1.2)%. Seventy-three (12.4%) patients were in delayed chemotherapy group and 518 (87.6%) patients were in non-delayed chemotherapy group. The reasons for chemotherapy delay included 72 cases (98.6%) of severe infection, 65 cases (89.0%) of bone marrow suppression, 35 cases (47.9%) of organ dysfunction, 22 cases (30.1%) of tumor lysis syndrome,etc. There were 7 cases of chemotherapy delay in group B, which were seen in COPADM (vincristine+cyclophosphamide+prednisone+daunorubicin+methotrexate+intrathecal injection,4 cases) and CYM (methotrexate+cytarabine+intrathecal injection,3 cases) stages. There were 66 cases of chemotherapy delay in group C, which were common in COPADM (28 cases) and CYVE 1 (low dose cytarabine+high dose cytarabine+etoposide+methotrexate, 12 cases) stages. Multinomial Logistic regression analysis showed that the age over 10 years old ( OR=0.54,95% CI 0.30-0.93), tumor lysis syndrome before chemotherapy ( OR=0.48,95% CI 0.27-0.84) and grade Ⅲ-Ⅳ myelosuppression after chemotherapy ( OR=0.55,95% CI 0.33-0.91)were independent risk factors for chemotherapy delay.The 3-year OS rate and the 3-year EFS rate of children with Burkitt lymphoma in the delayed chemotherapy group were lower than those in the non-delayed chemotherapy group ((79.4±4.9)% vs. (94.2±1.1)%, (80.2±4.8)% vs. (92.0±1.2)%,both P<0.05). The 3-year OS rate of the group C with chemotherapy delay >7 days (42 cases) was lower than that of the group with chemotherapy delay of 1-7 days (22 cases) and the non-delay group (399 cases) ((76.7±6.9)% vs. (81.8±8.2)% vs. (92.7±1.3)%, P=0.002).The 3-year OS rate of the chemotherapy delay group (9 cases) in the COP (vincristine+cyclophosphamide+prednisone) phase was lower than that of the non-chemotherapy delay group (454 cases) ((66.7±15.7)% vs. (91.3±1.4)%, P=0.005). Similarly, the 3-year OS rate of the chemotherapy delay group (11 cases) in the COPADM1 phase was lower than that of the non-chemotherapy delay group (452 cases) ((63.6±14.5)% vs. (91.5±1.3)%, P=0.001). Conclusions:The delayed chemotherapy was related to the age over 10 years old, tumor lysis syndrome before chemotherapy and grade Ⅲ-Ⅳ myelosuppression after chemotherapy in pediatric BL. There is a significant relationship between delayed chemotherapy and prognosis of BL in children.

Group A Streptococcus (GAS) are important human pathogens.In recent years, the M1 UK strain has attracted widespread attention in the United Kingdom and other countries because it has been associated with a surge in scarlet fever and an increase in invasive GAS infections.Author conducted a whole-genome sequencing study of 42 GAS strains from 2016 to 2018 in Shenzhen, and found that a GAS strain isolated from a child with scarlet fever in Shenzhen area in 2018 was homologous to M1 UK, which is the first strain of M1 UK confirmed in the mainland of China.For this reason, hereby publish it with a view to attracting the attention of our domestic counterparts and safeguarding public health safety.

Objective To investigate the relationship among circulating soluble major histocompatibility complex class Ⅰ-related chain A(sMICA),soluble major histocompatibility complex class Ⅰ-related chain B(sMICB),the activity of systemic lupus erythematosus(SLE)and autoantibodies.Methods A total of 156 SLE patients(SLE group)and 103 healthy volunteers(control group)who underwent physical examination in outpatient physical examination center were selected from the Qianjiang Hospital Affiliated to Chongqing University from January 2020 to January 2023.According to SLE disease activity score(SLEDAI),these SLE patients were divided into mild activity group(n=43),moderate activity group(n=69),and severe activity group(n=44).Serum levels of sMICA and sMICB,and the proportion of autoantibodies and peripheral blood NK cells were detected.Spearman or Pearson method was used to analyze the correlation among sMICA,sMICB,score,autoantibodies and peripheral blood NK cells proportion.Receiver operating characteristics(ROC)curve was used to evaluate the value of sMICA and sMICB in the diagnosis of SLE activity.Results Serum sMICA(173.65±23.92 pg/ml)and sMICB(96.35±15.74 pg/ml)levels in SLE group were higher than those in control group(32.51±6.27 pg/ml,12.03±2.47 pg/ml),while the proportion of CD3-CD56+NK cells(12.02％±2.65％)in peripheral blood was lower than that in control group(18.35％±3.71％),and the differences were statistically significant(t=58.498,53.897,-16.010,all P＜0.05).Serum sMICA and sMICB levels in severe active group were higher than those in moderately active group and mildly active group(t=8.192,12.352;19.652,23.742,all P＜0.05),and the proportion of CD3-CD56+NK cells in peripheral blood was lower than that in moderate and mild active groups(t=8.154,10.658,P＜0.05).The differences in positive rates of anti-dsDNA antibody,anti-nuclear antibody,anti-nucleosome antibody and anti-histone antibody in SLE patients with different disease activities were significant(x2=8.795,7.216,7.539,8.946,all P＜0.05).Serum sMICA and sMICB levels in SLE patients were positively correlated with SLED AI score,anti-dsDNA antibody,anti-nuclear antibody,anti-nucleosome antibody and anti-histone antibody(r=0.206～0.402,all P＜0.05),and negatively correlated with the proportion of CD3-CD56+NK cells in peripheral blood(r=-0.563,-0.427,all P＜0.05).The areas under the curve of SLE in severe active group diagnosed by sMICA and sMICB alone were 0.652 and 0.704,respectively.The area under the curve of SLE in severe active group diagnosed by sMICA and sMICB combined with SLE was 0.812,which was higher than that by the single diagnosis(Z=3.050,2.346,all P＜0.05).Conclusion The increased serum sMICA and sMICB levels in SLE patients were associated with the increased positive rate of SLE autoantibodies,the decreased proportion of NK cells in peripheral blood and the enhanced disease activity,which could be used as potential markers of SLE.

Following the principles of evidence-based medicine,in accordance with the structure and drafting rules of standardized documents,based on literature research,according to the characteristics of chronic cough in children and issues that need to form a consensus,the TCM Guidelines for Diagnosis and Treatment of Chronic Cough in Children was formulated based on the Delphi method,expert discussion meetings,and public solicitation of opinions.The guideline includes scope of application,terms and definitions,eti-ology and diagnosis,auxiliary examination,treatment,prevention and care.The aim is to clarify the optimal treatment plan of Chinese medicine in the diagnosis and treatment of this disease,and to provide guidance for improving the clinical diagnosis and treatment of chronic cough in children with Chinese medicine.