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.

Objective To investigate the effects of comprehensive nutrition management on glycolipid metabolism and pregnancy outcomes in patients with gestational diabetes mellitus(GDM).Methods A total of 121 pregnant women with GDM at 24-28 weeks gestation who were registered in the obstetrics department of 6 sub-central hospi-tals in China from May 2021 to July 2021 were included in this study and were randomly divided into intervention group(n=74)and control group(n=47).The intervention group received intensive comprehensive nutrition man-agement,including at least 6 outpatient interventions,individualized nutrition management and a half-day standard-ized outpatient education on gestational diabetes mellitus,continuous dynamic blood glucose monitoring and micro-blood glucose monitoring,and routine check of glycated albumin and urine every 4 weeks.Body weight,body com-position and diet and exercise implementation procedures and fetal development as well as complications were recor-ded.The control group received conventional nutritional guidance.The two groups were compared for difference in blood glucose related indicators at 37 weeks of gestation,weight gain before delivery,some lipid metabolism indica-tors,pregnancy outcomes,and oral glucose tolerance test(OGTT)at 42 days postpartum.Results Compared with the control group,the level of prenatal fasting blood glucose(P=0.006),intravenous plasma glucose(P=0.009)and blood ketone(P = 0.044)in the intervention group was significantly reduced.There was no significant difference in weight gain and weight attainment rate between the two groups.The 2-hour postpartum OGTTs of preg-nant women in the intervention group(P=0.006)were significantly lower than those in the control group,and the incidence of preeclampsia and postpartum blood loss were lower than those in the control group but no statistical difference was found.For newborns,the incidence of macrosomia(P=0.042)and planation(P=0.048)in the in-tervention group was slightly lower than that in the control group,and the results were statistically different.Other adverse pregnancy outcomes were not statistically different between the two groups.Conclusions Intensive compre-hensive nutrition management has a positive impact on the control of the blood glucose in pregnant women and im-proves the maternal and neonatal outcomes of women with GDM.

Objective:To investigate the correlation of the emm genotypes and virulence genes with the isolation sites of Group A Streptococcus (GAS). Methods:It was a retrospective study.The specimens were collected from children with impetigo in Beijing Children′s Hospital, Capital Medical University from 2006 to 2008 for GAS isolation and identification.A total of 24 GAS strains were isolated from 16 children with impetigo, among which 7 pairs of strains were isolated from the throat and skin of 7 children, and 1 pair of strains was isolated from the vulva and skin of one child, and the remaining 8 GAS strains were isolated from the skin pus samples of 8 children.Polymerase chain reaction was applied to detect the emm genotypes and 13 virulence genes ( speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ and ssa). The correlation of the emm genotypes and virulence genes with the isolation sites of GAS strains was analyzed. Results:In this study, four emm genotypes were detected, including emm1.0 (15/24), emm12.0 (4/24), emm22.0 (2/24) and emm160.0 (1/24), and one subtype emm12.19 (2/24) was detected as well.The carrying rates of 13 virulence genes speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ and ssa were 58.3%, 100%, 91.7%, 100%, 50.0%, 12.5%, 54.2%, 66.7%, 16.7%, 25.0%, 12.5%, 100% and 91.7%, respectively.All strains carried 5 to 11 virulence genes and they all carried speB, speF and smeZ.There were significant differences in the carrying rate of speA and speJ among the strains with different emm genotypes (all P<0.05). There was no significant difference in the distribution of virulence genes between skin isolates and pharyngeal isolates, including the 5 pairs of strains carrying the emm1.0 genotype (all P>0.05). Conclusions:The distribution of virulence gene of GAS in children with impetigo is significantly correlated with the emm genotype, rather than the isolation site.

Objective:To investigate the Helicobacter pylori ( H. pylori) infection of Tibetan families and individuals in the Western Sichuan Plateau region and explore the related factors which affected H. pylori infection. Methods:This was a single-center cross-sectional study. Questionnaires were collected from 50 Tibetan families including 155 individuals in Western Sichuan Plateau region during March to May 2023. The 13C-urea breath test was performed to confirm the current infection status of participants. Binary logistic regression were used to analyze the related factors associated with H. pylori infection. Results:Among the 50 Tibetan households, the individual-based H. pylori infection rate was 47.10%(73/155), with two out of nine children and 48.63%(71/146) adults infected. The age group of 18 to 40 years had the highest infection rate (55.00%, 11/20). The prevalence of infection based on family was 80.00%(40/50), of which 16.00%(8/50) had all family members infected. Of the 59 couples surveyed, 23.73%(14/59) were both infected, and 45.76%(27/59) had one person infected. Of the six families which had children and adolescents, two households had their children infected. Logistic regression analysis showed that size of the family was a factor related to H. pylori infection (odds ratio=3.038, 95% confidence interval 1.043 to 10.491, P=0.042). Conclusions:The family-based H. pylori infection rate is relatively high in Tibetan residents in the Western Sichuan Plateau, and larger family size is related with higher risk of H. pylori infection within the family.

Bone metabolism includes the processes of bone formation and bone resorption, both of which maintain bone metabolic homeostasis in the body. Adipose browning is a biological process that converts energy-storing white fat into thermogenic brown fat, which is induced by environment, exercise, nutrients, and signaling molecules. Adipose browning regulates bone metabolism in vivo and affects osteogenic and osteoblastic capacity through the secretion of adipokines such as fibroblast growth factor-21, adiponectin, insulin-like growth factor-1, and bone morphogenetic proteins. Adipose browning can also affect bone metabolism through immune pathways mediated by the gut microbiota. The browning ability of fat decreases in the aging body, which is related to the imbalance of bone metabolism in the state of osteoporosis. In children and adolescents, fat browning is active and bone metabolism is maintained in a healthy state. Exercise and supplementation of nutrients (capsaicin, resveratrol, quercetin, etc.) can promote the browning of adipose tissue and maintain brown adipose tissue, which plays a positive role in bone metabolism. In the future, it is of great significance to clarify the specific regulatory mode between adipose browning and bone metabolism for the treatment of bone metabolism-related diseases by intervening adipose browning.

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 summarize the clinical and neurophysiological characteristics of epilepsy with blink inducing.Methods:The patients with epilepsy with blink test positive who received 24 h-video-electroencephalography (24 h-VEEG) monitoring from May 2017 to May 2022 in the Xijing Hospital, the Air Force Military Medical University were enrolled. Their clinical and electrophysiological characteristics were studied and they were followed up to observe their prognosis.Results:A total of 42 patients with epilepsy with blink test positive were collected, 1 of whom was lost to follow-up. The remaining 41 patients included 18 males (44%) and 23 females (56%), whose age was 3 to 12 (8.1±2.6) years. Self-limited epilepsy with centrotemporal spikes (SeLECTS) was diagnosed in 35 patients, self-limited epilepsy with autonomic seizures in 3, and developmental epileptic encephalopathy with spike-and-wave activation in sleep in 3, respectively. The electrical status epilepticus during sleep (ESES) was found in 31 patients (76%), whereas 10 (24%) without ESES. Thirty-two patients experienced 24 h-VEEG monitoring more than twice, and 23 of them were seizure free, of whom blink inducing disappeared in 14 patients and existed in 9 in the last 24 h-VEEG monitoring. Among the 9 patients who were not seizure free, blink inducing disappeared in 3 patients and remained in 6. There was no statistically significant difference between the two groups ( P>0.05). The age of the patients whose blink inducing disappeared in the last 24 h-VEEG monitoring after treatment was (11.3±3.1) years. Meanwhile the age of the patients whose blink inducing remained was (9.1±2.3) years, and the difference between the two groups was statistically significant ( t=2.254, P=0.030). Conclusions:Blink inducing is highly age-dependent and common in self-limited focal epilepsy and developmental epileptic encephalopathy, especially in SeLECTS. Moreover, patients with ESES are more likely to be blink test positive. There was no correlation between blink inducing and seizure outcome.

Objective:To investigate the incidence and risk factors of deep vein thrombosis(DVT)in patients with rheumatoid arthritis(RA).Methods:The clinical data of RA patients who were hospi-talized in the Department of Rheumatology and Immunology of Aerospace Center Hospital from May 2015 to September 2021 was retrospectively analyzed,including demographic characteristics,concomitant diseases,laboratory examinations(blood routine,biochemistry,coagulation,inflammatory markers,rheumatoid factor,antiphospholipid antibodies and lupus anticoagulant,etc.)and treatment regimens.The patients were compared according to the presence or absence of DVT,and the t test,Mann-Whitney U test or Chi-square test were applied to screen for relevant factors for DVT,followed by Logistic regres-sion analysis to determine risk factors for DVT in patients with RA.Results:The incidence of DVT in the RA patients was 9.6％(31/322);the median age of RA in DVT group was significantly older than that in non-DVT group[64(54,71)years vs.50(25,75)years,P＜0.001];the level of disease activity score using 28 joints(DAS28)-erythrocyte sedimentation rate(ESR)in DVT group was higher than that in non-DVT group[5.2(4.5,6.7)vs.4.5(4.5,5.0),P＜0.001];the incidence of hypertension,chronic kidney disease,fracture or surgery history within 3 months,and varicose veins of the lower ex-tremities in DVT group was higher than that in non-DVT group(P＜0.001).The levels of hemoglobin and albumin in DVT group were significantly lower than that in non-DVT group(P=0.009,P=0.004),while the D-dimer level and rheumatoid factor positive rate in DVT group were significantly higher than that in non-DVT group(P＜0.001).The use rate of glucocorticoid in DVT group was higher than that in non-DVT group(P=0.009).Logistic regression analysis showed that the age(OR=1.093,P＜0.001),chronic kidney disease(OR=7.955,P=0.005),fracture or surgery history with-in 3 months(OR=34.658,P=0.002),DAS28-ESR(OR=1.475,P=0.009),and the use of glu-cocorticoid(OR=5.916,P=0.003)were independent risk factors for DVT in RA patients.Conclu-sion:The incidence of DVT in hospitalized RA patients was significantly increased,in addition to tradi-tional factors,such as age and chronic kidney disease,increased DAS28-ESR level and the use of glu-cocorticoid were also independent risk factors for DVT.

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.

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.