OBJECTIVE To observe the effect of Shixiang plaster on promoting the wound healing of diabetic foot ulcer.METHODS Totally 50 male SPF grade SD rats were prepared to establish the diabetic models by feeding with high glucose and high fat forage and intraperitoneal injection of streptozotocin,the rats models that were es-tablished successfully were randomly divided into the model group,the Shixiang plaster group and the Kangfuxin solution group.The models of diabetic ulcers were established.The Shixiang plaster group was treated with exter-nal Shixiang plaster,the Kangfuxin solution group was given external Kangfuxin solution,and the model group was treated with coverage with sterile gauze.The wound healing status of the rats was observed,the wound tis-sues were collected for bacterial culture and hematoxylin-eosin(HE)staining after drug administration for 14 and 28 days,respectively.The expression levels of nuclear factor-red cell-2-related factor 2(Nrf-2),heme oxygenase-1(HO-1),tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and vascular endothelial growth factor(VEGF)were detected by immunohistochemistry(IHC),the expression levels of Nrf-2 and HO-1 were detected with the use of Western Blot,and the levels of serum malondialdehyde(MDA),superoxide dismutase(SOD)and reactive oxygen species(ROS)were detected by enzyme-linked immunosorbent assay(ELISA).RESULTS After the drug administration for 14 and 28 days,the wound healing rates of the Shixiang plaster group were(62.15±3.82)％and(81.68±3.83)％,respectively,higher than(47.14±2.80)％and(69.96±6.49)％of the Kangfuxin solu-tion group and(29.14±9.52)％and(57.91±6.63)％of the model group,and there were significant differences(F=21.716,12.626,P=0.002,0.007).The bacterial colony counts of the Shixiang plaster group were less than those of the Kangfuxin solution group and the model group after the drug administration for 14 and 28 days(P＜0.05).The result of HE staining showed that the Shixiang plaster group had a better wound healing.The result of IHC indicated that the expression levels of Nrf-2,HO-1 and VEGF of the Kangfuxin solution group and the Shix-iang plaster group were up-regulated after the drug administration for 28 days,while the expression levels of TNF-α and IL-6 were down-regulated.The expression levels of Nrf-2 and HO-1 proteins of the Shixiang plaster group were higher than those of the Kangfuxin solution group and the model group after the drug administration for 14 and 28 days,the levels of serum MDA and ROS of the Shixiang plaster group were lower than those of the Kangfuxin solution group and the model group,and the serum SOD level of the Shixiang plaster group was higher than that of the model group(P＜0.05).CONCLUSIONS Shixiang plaster can effectively promote the wound heal-ing of the rats with diabetic foot ulcers and reduce the bacterial colony counts of wound surfaces.The mechanism may be associated with the alleviation of oxidative stress injury by mediating the Nrf-2/HO-1 signaling pathways,promotion of angiogenesis and inhibition of excessive inflammatory reactions.

OBJECTIVE To observe the effect of Shixiang plaster on promoting the wound healing of diabetic foot ulcer.METHODS Totally 50 male SPF grade SD rats were prepared to establish the diabetic models by feeding with high glucose and high fat forage and intraperitoneal injection of streptozotocin,the rats models that were es-tablished successfully were randomly divided into the model group,the Shixiang plaster group and the Kangfuxin solution group.The models of diabetic ulcers were established.The Shixiang plaster group was treated with exter-nal Shixiang plaster,the Kangfuxin solution group was given external Kangfuxin solution,and the model group was treated with coverage with sterile gauze.The wound healing status of the rats was observed,the wound tis-sues were collected for bacterial culture and hematoxylin-eosin(HE)staining after drug administration for 14 and 28 days,respectively.The expression levels of nuclear factor-red cell-2-related factor 2(Nrf-2),heme oxygenase-1(HO-1),tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and vascular endothelial growth factor(VEGF)were detected by immunohistochemistry(IHC),the expression levels of Nrf-2 and HO-1 were detected with the use of Western Blot,and the levels of serum malondialdehyde(MDA),superoxide dismutase(SOD)and reactive oxygen species(ROS)were detected by enzyme-linked immunosorbent assay(ELISA).RESULTS After the drug administration for 14 and 28 days,the wound healing rates of the Shixiang plaster group were(62.15±3.82)％and(81.68±3.83)％,respectively,higher than(47.14±2.80)％and(69.96±6.49)％of the Kangfuxin solu-tion group and(29.14±9.52)％and(57.91±6.63)％of the model group,and there were significant differences(F=21.716,12.626,P=0.002,0.007).The bacterial colony counts of the Shixiang plaster group were less than those of the Kangfuxin solution group and the model group after the drug administration for 14 and 28 days(P＜0.05).The result of HE staining showed that the Shixiang plaster group had a better wound healing.The result of IHC indicated that the expression levels of Nrf-2,HO-1 and VEGF of the Kangfuxin solution group and the Shix-iang plaster group were up-regulated after the drug administration for 28 days,while the expression levels of TNF-α and IL-6 were down-regulated.The expression levels of Nrf-2 and HO-1 proteins of the Shixiang plaster group were higher than those of the Kangfuxin solution group and the model group after the drug administration for 14 and 28 days,the levels of serum MDA and ROS of the Shixiang plaster group were lower than those of the Kangfuxin solution group and the model group,and the serum SOD level of the Shixiang plaster group was higher than that of the model group(P＜0.05).CONCLUSIONS Shixiang plaster can effectively promote the wound heal-ing of the rats with diabetic foot ulcers and reduce the bacterial colony counts of wound surfaces.The mechanism may be associated with the alleviation of oxidative stress injury by mediating the Nrf-2/HO-1 signaling pathways,promotion of angiogenesis and inhibition of excessive inflammatory reactions.

Objective:To report the nationwide surveillance results of pathogenic profiles and antimicrobial resistance patterns of Gram-positive bloodstream infections in China in 2023.Methods:The clinical isolates of Gram-posttive bacteria from blood cultures were collected in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）during January to December 2023. Antimicrobial susceptibility testing was performed using the dilution method recommended by the Clinical and Laboratory Standards Institute（CLSI）. Statistical analyses were conducted using WHONET 5.6 and SPSS 25.0 software.Results:A total of 4 385 Gram-positive bacterial isolates were obtained from 60 participating center. The top five pathogens were Staphylococcus aureus（ n=1 544，35.2%），coagulase-negative Staphylococci（ n=1 441，32.9%）， Enterococcus faecium（ n=574，13.1%）， Enterococcus faecalis（ n=385，8.8%），and α-hemolytic Streptococci（ n=187，4.3%）. The prevalence of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）was 26.2%（405/1 544）and 69.8%（1 006/1 441），respectively. Notably，all Staphylococci remained susceptible to glycopeptide or daptomycin. Staphylococcus aureus demonstrated excellent susceptibility（>97.0%）to cephalobiol，rifampicin，trimethoprim-sulfamethoxazole，linezolid，minocycline，tigecycline，and eravacycline. No Enterococcus exhibiting resistance to linezolid were detected. Glycopeptide resistance was uncommon but more frequent in Enterococcus faecium（resistance to vancomycin and teicoplanin：both 1.7%）compared to Enterococcus faecalis（both 0.3%）. The detection rates of MRSA and MRCNS exhibited significant regional variations across the country（ χ2=17.674 and 148.650，respectively，both P<0.001）. No vancomycin-resistant Enterococci were detected in central China. Institutional comparison demonstrated higher prevalence of MRSA（ χ2=14.111， P<0.001）and MRCNS（ χ2=4.828， P=0.028）in provincial hospitals than that in municipal hospitals. Socioeconomic analysis identified elevated detection rates of both MRSA（ χ2=18.986， P<0.001）and MRCNS（ χ2=4.477， P=0.034）in less developed regions（per capita GDP

Objective:To report the results of bacterial resistant investigation collaborative system（BRICS）on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2023，and provide reference for clinical tretment of bloodstream infections and prevention and control of bacterial resistance.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of BRICS were collected during January 2023 to December 2023. 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 were used to analyze the data.Results:During the study period，11 492 strains of Gram-negative bacteria were collected from 60 hospitals，of which 10 098（87.9%）were Enterobacterales and 1 394（12.1%）were non-fermentative bacteria. The top 5 bacterial species were Escherichia coli（50.0%）， Klebsiella pneumoniae（26.1%）， Pseudomonas aeruginosa（5.1%）， Acinetobacter baumannii complex（5.0%）and Enterobacter cloacae complex（4.1%）. The ESBL-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus mirablilis were 46.8%（2 685/5 741），18.3%（549/2 999）and 44.0%（77/175），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（76/5 741）and 15.0%（450/2 999）；32.9%（25/76）and 78.0%（351/450）of CREC and CRKP were sensitive to ceftazidime/avibactam combination，respectively. 94.7%（72/76）and 90.2%（406/450）of CREC and CRKP were sensitive to aztreonam/avibactam combination. Furthermore，57.9%（44/76）and 79.1%（356/450）were sensitive to imipenem/relebactam combination. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 64.6%（370/573），while more than 80.0% of CRAB complex was sensitive to tigecycline，eravacycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 17.0%（99/581）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of important Gram-negative bacteria resistance among different regions in China，with statistically significant differences in the prevalence of CREC，CRKP，CRPA and CRAB complex（ χ2=10.6，28.6，10.8 and 19.3， P<0.05）. The prevalence of ESBL-producing Escherichia coli， CREC，CRAB complex and CRKP were higher in provincial hospitals than those in municipal hospitals（ χ2=12.5，9.8，12.7 and 57.8，all P<0.01）. Conclusions:Gram-negative bacteria are the main pathogens causing bloodstream infections in China，and Escherichia coli is ranked in the top，while the trend of Klebsiella pneumoniae increases continuously with time. CRKP infection shows a slow upward trend，CREC infecton maintains a low prevalence level，and CRAB complex infection continues to exhibit a high prevalence rate. The composition and resistance patterns of pathogens causing bloodstream infections vary to some extent across different regions and levels of hospitals in China.

Objective:To report the nationwide surveillance results of pathogenic profiles and antimicrobial resistance patterns of Gram-positive bloodstream infections in China in 2023.Methods:The clinical isolates of Gram-posttive bacteria from blood cultures were collected in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）during January to December 2023. Antimicrobial susceptibility testing was performed using the dilution method recommended by the Clinical and Laboratory Standards Institute（CLSI）. Statistical analyses were conducted using WHONET 5.6 and SPSS 25.0 software.Results:A total of 4 385 Gram-positive bacterial isolates were obtained from 60 participating center. The top five pathogens were Staphylococcus aureus（ n=1 544，35.2%），coagulase-negative Staphylococci（ n=1 441，32.9%）， Enterococcus faecium（ n=574，13.1%）， Enterococcus faecalis（ n=385，8.8%），and α-hemolytic Streptococci（ n=187，4.3%）. The prevalence of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）was 26.2%（405/1 544）and 69.8%（1 006/1 441），respectively. Notably，all Staphylococci remained susceptible to glycopeptide or daptomycin. Staphylococcus aureus demonstrated excellent susceptibility（>97.0%）to cephalobiol，rifampicin，trimethoprim-sulfamethoxazole，linezolid，minocycline，tigecycline，and eravacycline. No Enterococcus exhibiting resistance to linezolid were detected. Glycopeptide resistance was uncommon but more frequent in Enterococcus faecium（resistance to vancomycin and teicoplanin：both 1.7%）compared to Enterococcus faecalis（both 0.3%）. The detection rates of MRSA and MRCNS exhibited significant regional variations across the country（ χ2=17.674 and 148.650，respectively，both P<0.001）. No vancomycin-resistant Enterococci were detected in central China. Institutional comparison demonstrated higher prevalence of MRSA（ χ2=14.111， P<0.001）and MRCNS（ χ2=4.828， P=0.028）in provincial hospitals than that in municipal hospitals. Socioeconomic analysis identified elevated detection rates of both MRSA（ χ2=18.986， P<0.001）and MRCNS（ χ2=4.477， P=0.034）in less developed regions（per capita GDP

Objective:To report the results of bacterial resistant investigation collaborative system（BRICS）on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2023，and provide reference for clinical tretment of bloodstream infections and prevention and control of bacterial resistance.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of BRICS were collected during January 2023 to December 2023. 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 were used to analyze the data.Results:During the study period，11 492 strains of Gram-negative bacteria were collected from 60 hospitals，of which 10 098（87.9%）were Enterobacterales and 1 394（12.1%）were non-fermentative bacteria. The top 5 bacterial species were Escherichia coli（50.0%）， Klebsiella pneumoniae（26.1%）， Pseudomonas aeruginosa（5.1%）， Acinetobacter baumannii complex（5.0%）and Enterobacter cloacae complex（4.1%）. The ESBL-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus mirablilis were 46.8%（2 685/5 741），18.3%（549/2 999）and 44.0%（77/175），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（76/5 741）and 15.0%（450/2 999）；32.9%（25/76）and 78.0%（351/450）of CREC and CRKP were sensitive to ceftazidime/avibactam combination，respectively. 94.7%（72/76）and 90.2%（406/450）of CREC and CRKP were sensitive to aztreonam/avibactam combination. Furthermore，57.9%（44/76）and 79.1%（356/450）were sensitive to imipenem/relebactam combination. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 64.6%（370/573），while more than 80.0% of CRAB complex was sensitive to tigecycline，eravacycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 17.0%（99/581）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of important Gram-negative bacteria resistance among different regions in China，with statistically significant differences in the prevalence of CREC，CRKP，CRPA and CRAB complex（ χ2=10.6，28.6，10.8 and 19.3， P<0.05）. The prevalence of ESBL-producing Escherichia coli， CREC，CRAB complex and CRKP were higher in provincial hospitals than those in municipal hospitals（ χ2=12.5，9.8，12.7 and 57.8，all P<0.01）. Conclusions:Gram-negative bacteria are the main pathogens causing bloodstream infections in China，and Escherichia coli is ranked in the top，while the trend of Klebsiella pneumoniae increases continuously with time. CRKP infection shows a slow upward trend，CREC infecton maintains a low prevalence level，and CRAB complex infection continues to exhibit a high prevalence rate. The composition and resistance patterns of pathogens causing bloodstream infections vary to some extent across different regions and levels of hospitals in China.

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.

End-stage liver diseases,such as cirrhosis and liver cancer caused by hepatitis B,are often combined with hepatic encephalopathy(HE);ammonia poisoning is posited as one of its main pathogenesis mechanisms.Ammonia is closely related to autophagy,but the molecular mechanism of ammonia's regulatory effect on autophagy in HE remains unclear.Sialylation is an essential form of glycosylation.In the nervous system,abnormal sialylation affects various physiological processes,such as neural development and synapse formation.ST3 β-galactoside α2,3-sialyltransferase 6(ST3GAL6)is one of the significant glycosyltransferases responsible for adding α2,3-linked sialic acid to substrates and generating glycan structures.We found that the expression of ST3GAL6 was upregulated in the brains of mice with HE and in astrocytes after ammonia induction,and the expression levels of α2,3-sialylated glycans and autophagy-related proteins microtubule-associated protein light chain 3(LC3)and Beclin-1 were upregulated in ammonia-induced astrocytes.These findings suggest that ST3GAL6 is related to autophagy in HE.Therefore,we aimed to determine the regulatory relationship between ST3GAL6 and autophagy.We found that silencing ST3GAL6 and blocking or degrading α2,3-sialylated glycans by way of Maackia amurensis lectin-Ⅱ(MAL-Ⅱ)and neuraminidase can inhibit autophagy.In addition,silencing the expression of ST3GAL6 can downregulate the expression of heat shock protein β8(HSPB8)and Bcl2-associated athanogene 3(BAG3).Notably,the overexpression of HSPB8 partially restored the reduced autophagy levels caused by silencing ST3GAL6 expression.Our results indicate that ST3GAL6 regulates autophagy through the HSPB8-BAG3 complex.

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.