Objective This study aimed to investigate the antimicrobial resistance profiles of bacterial strains isolated from pediatric intensive care units(PICU)in China for better antimicrobial therapy.Methods Clinical isolates were collected from 17 institutions,including tertiary care children's hospitals and pediatric department of tertiary general hospitals in China from January 1,2020 to December 31,2022.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Results were interpreted according to the breakpoints released by the Clinical and Laboratory Standards Institute(CLSI)in 2020.Results A total of 10 688 isolates were collected,including gram-positive organisms(39.2％)and gram-negative organisms(60.8％).The top three organisms were S.aureus(13.6％,1 453/10 688),A.baumannii(10.0％,1 067/10 688),and coagulase-negative Staphylococcus(9.9％,1 058/10 688).Multi-drug resistant organisms(MDROs)were very common in children.The prevalence of methicillin-resistant Staphylococcus aureus(MRSA),carbapenem-resistant Enterobacterales(CRE),carbapenem-resistant E.coli,carbapenem-resistant K.pneumoniae(CRKP),carbapenem-resistant A.baumannii(CRAB),and carbapenem-resistant P.aeruginosa(CRPA)was 41.1％,19.4％,8.8％,30.9％,67.4％,and 28.8％,respectively.Overall,more than 50％of Enterobacteriales isolates were resistant to cephalosporins,while nearly 25％of Enterobacteriales isolates were resistant to carbapenems.MDROs were highly resistant to commonly used antibiotics.More than 80％of CRE and CRAB strains were resistant to all beta-lactam antibiotics.CRE and CRAB showed low resistance rates to tigecycline and polymyxin.CRPA showed lower resistance rates to piperacillin,beta-lactamase inhibitor combinations than the resistance rates to third and fourth generation cephalosporins.All of the Staphylococcus and Enterococcus isolates were susceptible to vancomycin and tigecycline.None of PRSP strains isolated from meningitis and nonmeningitis samples were resistant to rifampicin,vancomycin,or linezolid.The prevalence of β-lactamase-negative ampicillin-resistant(BLNAR)strains was 43.3％in Haemophilus influenzae.Conclusions MDROs were prevalent in PICU.It is necessary to establish an effective multidisciplinary team(MDT)to control the antimicrobial resistance.

BACKGROUND:Patients with Alzheimer's disease have severe brain energy disorders.In recent years,brain energy rescue strategies based on ketone body intervention have attracted more and more attention in the treatment of Alzheimer's disease.OBJECTIVE:To investigate whether β-hydroxybutyric acid can improve energy dysfunction by improving mitochondrial bioenergy function in HT22 cells of mouse hippocampal neurons induced by amyloid-β protein 1-42 (Aβ1-42).METHODS:HT22 cells were divided into four groups:Control,β-hydroxybutyric acid,Aβ1-42,Aβ1-42+β-hydroxybutyric acid.Related detection kits were respectively used to detect HT22 cell survival rate,adenosine triphosphate level,α-ketoglutarate dehydrogenase activity,Na+K+-ATPase activity,mitochondrial membrane potential,and reactive oxygen species levels.RESULTS AND CONCLUSION:Compared with the control group,the survival rate,adenosine triphosphate level,α-ketoglutarate dehydrogenase activity,Na+K+-ATPase activity,and mitochondrial membrane potential of HT22 cells were significantly decreased (P<0.05),and the level of reactive oxygen species was significantly increased (P<0.05) in the Aβ1-42 group.Compared with the Aβ1-42 group,the survival rate,adenosine triphosphate level,α-ketoglutarate dehydrogenase activity,Na+K+-ATPase activity,and mitochondrial membrane potential of HT22 cells were significantly increased (P<0.05),and the reactive oxygen species level was significantly decreased (P<0.05) in the Aβ1-42+β-hydroxybutyric acid group.These results showed that β-hydroxybutyric acid improved mitochondrial bioenergetic function and ultimately improved Aβ1-42-induced energy impairment and survival rate in HT22 cells.

Objective:To develop a bacterial endotoxin detection method suitable for mRNA vaccines based on lipid nanoparticle（LNP）delivery system.Methods:The gel clot limit test outlined in the third section of the Chinese Pharmacopoeia（2020 edition）was utilized. Taking the human herpesvirus type 2 mRNA vaccine as the detection object，the optimal conditions for bacterial endotoxin detection were established by evaluating sample dilution factors，diluents，and other interfering elements. The results were validated using the recombinant C factor method. Finally，the applicability of the established method was validated through testing the respiratory syncytial virus mRNA vaccine and the shingles mRNA vaccine.Results:Increasing the sample dilution factor to 480 times with a magnesium-containing buffer and using 0.06 EU/ml tachypleus amebocyte lysate effectively mitigated the interference caused by LNP on the test results of the human herpesvirus type 2 mRNA vaccine，the respiratory syncytial virus mRNA vaccine，and the shingles mRNA vaccine. The results from recombinant C factor method and the gel clot limit method were consistent.Conclusion:A bacterial endotoxin gel clot limit detection method tailored for human herpesvirus type 2 mRNA vaccine，respiratory syncytial virus mRNA vaccine，and shingles mRNA vaccine is successfully developed based on existing protocols in the Chinese Pharmacopoeia（2020 edition）. This study offers insights for the detection of bacterial endotoxin in LNP-based biological products.

Objective:To develop a bacterial endotoxin detection method suitable for mRNA vaccines based on lipid nanoparticle（LNP）delivery system.Methods:The gel clot limit test outlined in the third section of the Chinese Pharmacopoeia（2020 edition）was utilized. Taking the human herpesvirus type 2 mRNA vaccine as the detection object，the optimal conditions for bacterial endotoxin detection were established by evaluating sample dilution factors，diluents，and other interfering elements. The results were validated using the recombinant C factor method. Finally，the applicability of the established method was validated through testing the respiratory syncytial virus mRNA vaccine and the shingles mRNA vaccine.Results:Increasing the sample dilution factor to 480 times with a magnesium-containing buffer and using 0.06 EU/ml tachypleus amebocyte lysate effectively mitigated the interference caused by LNP on the test results of the human herpesvirus type 2 mRNA vaccine，the respiratory syncytial virus mRNA vaccine，and the shingles mRNA vaccine. The results from recombinant C factor method and the gel clot limit method were consistent.Conclusion:A bacterial endotoxin gel clot limit detection method tailored for human herpesvirus type 2 mRNA vaccine，respiratory syncytial virus mRNA vaccine，and shingles mRNA vaccine is successfully developed based on existing protocols in the Chinese Pharmacopoeia（2020 edition）. This study offers insights for the detection of bacterial endotoxin in LNP-based biological products.

ObjectiveTo evaluate the clinical effectiveness and safety of Modified Zhigancao Granules （炙甘草汤加味颗粒） for preventing the early recurrence following radiofrequency ablation in patients with atrial fibrillation （AF） of qi-yin deficiency syndrome. MethodsA multi-center， randomized， double-blind， placebo-controlled trial was designed. A total of 116 patients with atrial fibrillation of qi-yin deficiency syndrome who underwent radiofrequency ablation for the first time were enrolled from 3 centers， and they were randomly divided into a treatment group （59 cases） and a control group （57 cases）. Both groups received basic western medicine treatment after surgery. In addition， the treatment group was given oral Modified Zhigancao Granules， while the control group was given oral placebo granules. The dosage for both groups was 20 g each time， twice a day， with continuous treatment for 12 weeks. The recurrence of atrial fibrillation in both groups was recorded at 24 hours， 4 weeks， 8 weeks， and 12 weeks after surgery. The serum levels of B-type natriuretic peptide （BNP）， interleukin-6 （IL-6）， high-sensitivity C-reactive protein （hs-CRP）， and tumor necrosis factor-α （TNF-α） were detected before treatment and 12 weeks after treatment in both groups. The scores of Atrial Fibrillation Effect on QualiTy-of-life （AFEQT） Questionnaire （including scores of the daily life dimension， symptom dimension， treatment worry dimension， treatment satisfaction dimension， and total score） and traditional Chinese medicine （TCM） syndrome scores were compared before treatment and at 4 weeks， 8 weeks， and 12 weeks between groups. Safety indicators such as blood routine， urine routine， liver function， and renal function were monitored before and after treatment. ResultsNine of the treatment group and seven of the control group dropped out. Finally， 50 patients in each group were included in the statistical analysis. At 24 hours， 4 weeks， 8 weeks， and 12 weeks after surgery， the recurrence rates of AF in the treatment group were 2.0% （1/50）， 2.0% （1/50）， 4.0% （2/50）， and 10.0% （5/50）， respectively； while those in the control group were 2.0% （1/50）， 26.0% （13/50）， 28.0% （14/50）， and 34.0% （17/50）， respectively. Compared with the control group at the same time points， the early recurrence rates of AF in the treatment group were significantly lower at 4 weeks， 8 weeks， and 12 weeks after surgery （P＜0.01）. Compared with the baseline within group， BNP， hs-CRP， IL-6， and TNF-α in the treatment group all decreased after 12 weeks of treatment （P＜0.05）； the difference in hs-CRP levels （before vs. after treatment） in the treatment group was higher than that in the control group （P＜0.01）. Compared with the baseline within group， both groups showed decreases in the total score of AFEQT Questionnaire， scores of the daily life dimension， treatment worry dimension， symptom dimension， and TCM syndrome scores at 4 weeks， 8 weeks， and 12 weeks after treatment. Meanwhile， the score of the treatment satisfaction dimension of AFEQT increased in both groups （P＜0.01）， and the improvements in all the above scores in the treatment group were superior to those in the control group at all time points （P＜0.05 or P＜0.01）. All safety indicators of patients in both groups were within the normal range before treatment and at 12 weeks after treatment， and no adverse reactions or adverse events occurred in either group. ConclusionModified Zhigancao Granules can reduce the early recurrence rate following radiofrequency ablation in AF patients with qi-yin deficiency syndrome， improve clinical symptoms and quality of life， suppress inflammatory response， and show good safety.

Booster vaccinations are highly recommended in combating the SARS-CoV-2 Omicron variant and its subvariants. However, the optimal booster vaccination strategies and related immune mechanisms with different prior vaccinations are under-revealed. In this study, we systematically evaluated the immune responses in mice and hamsters with different prime-boost regimens before their protective efficacies against Omicron were detected. We found that boosting with Ad5-nCoV, S_WT-2P or S_Omicron-6P induced significantly higher levels of neutralization activities against Omicron variants than CoronaVac and ZF2001 by eliciting stronger germinal center (GC) responses. Specifically, S_Omicron-6P induced even stronger antibody responses against Omicron variants in CoronaVac and Ad5-nCoV-primed animals than non-Omicron-specific vaccines but with limited differences as compared to Ad5-nCoV and S_WT-2P. In addition, boosting with a specific vaccine has the potential to remodel the existing immune profiles. These findings indicated that adenovirus-vectored vaccines and mRNA vaccines would be more effective than other types of vaccines as booster shots in combating Omicron infections. Moreover, the protective efficacies of the vaccines in booster vaccinations are highly related to GC reactions in secondary lymphatic organs. In summary, these findings provide timely important information on prime-boost regimens and future vaccine design.

Objective:To investigate the feasibility and clinical effects of ultra early enteral nutrition (≤24 h) in critically ill children supported by extracorporeal membrane oxygenation (ECMO).Methods:A retrospective cohort study was conducted. Clinical data of 43 critically ill children who received ECMO support in the pediatric intensive care unit (PICU) of Shanghai Children′s Hospital from January 2016 to December 2023 were collected, including general information, nutritional support modalities, and enteral nutrition tolerance. Based on the timing of enteral nutrition initiation, patients were divided into the within 24 h enteral nutrition group and the after 24 h enteral nutrition group. Nutritive indicators, nutritional intake, duration of ECMO support, duration of mechanical ventilation duration, and mortality rates were compared between the 2 groups using the two independent sample t test, Mann-Whitney U test, χ2 test and Fisher′s exact test. Results:Among the 43 children, 25 were male and 18 were female, with an age of 47 (18, 97) months. There were no statistically significant differences between the within 24 h enteral nutrition group (21 cases) and the after 24 h enteral nutrition group (22 cases) in terms of age, body mass index Z score, total protein, albumin, hemoglobin levels before ECMO support, duration of ECMO support, duration of mechanical ventilation, length of PICU stay, number of enteral nutrition intolerance events, number of enteral nutrition interruption, or mortality rate (all P>0.05). The protein intake adequacy rate during ECMO support was higher in the within 24 h enteral nutrition group than in the after 24 h enteral nutrition group (0 (0, 21%) vs. 0 (0, 0), U=175.00, P<0.05). Conclusions:Ultra early enteral nutrition is safe for children supported by ECMO. Initiating enteral nutrition within 24 h can increase the proportion of days with adequate protein intake in ECMO children without increasing the occurance of enteral nutrition intolerance or interruptions.

BACKGROUND:Patients with Alzheimer's disease have severe brain energy disorders.In recent years,brain energy rescue strategies based on ketone body intervention have attracted more and more attention in the treatment of Alzheimer's disease.OBJECTIVE:To investigate whether β-hydroxybutyric acid can improve energy dysfunction by improving mitochondrial bioenergy function in HT22 cells of mouse hippocampal neurons induced by amyloid-β protein 1-42 (Aβ1-42).METHODS:HT22 cells were divided into four groups:Control,β-hydroxybutyric acid,Aβ1-42,Aβ1-42+β-hydroxybutyric acid.Related detection kits were respectively used to detect HT22 cell survival rate,adenosine triphosphate level,α-ketoglutarate dehydrogenase activity,Na+K+-ATPase activity,mitochondrial membrane potential,and reactive oxygen species levels.RESULTS AND CONCLUSION:Compared with the control group,the survival rate,adenosine triphosphate level,α-ketoglutarate dehydrogenase activity,Na+K+-ATPase activity,and mitochondrial membrane potential of HT22 cells were significantly decreased (P<0.05),and the level of reactive oxygen species was significantly increased (P<0.05) in the Aβ1-42 group.Compared with the Aβ1-42 group,the survival rate,adenosine triphosphate level,α-ketoglutarate dehydrogenase activity,Na+K+-ATPase activity,and mitochondrial membrane potential of HT22 cells were significantly increased (P<0.05),and the reactive oxygen species level was significantly decreased (P<0.05) in the Aβ1-42+β-hydroxybutyric acid group.These results showed that β-hydroxybutyric acid improved mitochondrial bioenergetic function and ultimately improved Aβ1-42-induced energy impairment and survival rate in HT22 cells.

Objective This study aimed to investigate the antimicrobial resistance profiles of bacterial strains isolated from pediatric intensive care units(PICU)in China for better antimicrobial therapy.Methods Clinical isolates were collected from 17 institutions,including tertiary care children's hospitals and pediatric department of tertiary general hospitals in China from January 1,2020 to December 31,2022.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Results were interpreted according to the breakpoints released by the Clinical and Laboratory Standards Institute(CLSI)in 2020.Results A total of 10 688 isolates were collected,including gram-positive organisms(39.2％)and gram-negative organisms(60.8％).The top three organisms were S.aureus(13.6％,1 453/10 688),A.baumannii(10.0％,1 067/10 688),and coagulase-negative Staphylococcus(9.9％,1 058/10 688).Multi-drug resistant organisms(MDROs)were very common in children.The prevalence of methicillin-resistant Staphylococcus aureus(MRSA),carbapenem-resistant Enterobacterales(CRE),carbapenem-resistant E.coli,carbapenem-resistant K.pneumoniae(CRKP),carbapenem-resistant A.baumannii(CRAB),and carbapenem-resistant P.aeruginosa(CRPA)was 41.1％,19.4％,8.8％,30.9％,67.4％,and 28.8％,respectively.Overall,more than 50％of Enterobacteriales isolates were resistant to cephalosporins,while nearly 25％of Enterobacteriales isolates were resistant to carbapenems.MDROs were highly resistant to commonly used antibiotics.More than 80％of CRE and CRAB strains were resistant to all beta-lactam antibiotics.CRE and CRAB showed low resistance rates to tigecycline and polymyxin.CRPA showed lower resistance rates to piperacillin,beta-lactamase inhibitor combinations than the resistance rates to third and fourth generation cephalosporins.All of the Staphylococcus and Enterococcus isolates were susceptible to vancomycin and tigecycline.None of PRSP strains isolated from meningitis and nonmeningitis samples were resistant to rifampicin,vancomycin,or linezolid.The prevalence of β-lactamase-negative ampicillin-resistant(BLNAR)strains was 43.3％in Haemophilus influenzae.Conclusions MDROs were prevalent in PICU.It is necessary to establish an effective multidisciplinary team(MDT)to control the antimicrobial resistance.

Objective:To investigate the feasibility and clinical effects of ultra early enteral nutrition (≤24 h) in critically ill children supported by extracorporeal membrane oxygenation (ECMO).Methods:A retrospective cohort study was conducted. Clinical data of 43 critically ill children who received ECMO support in the pediatric intensive care unit (PICU) of Shanghai Children′s Hospital from January 2016 to December 2023 were collected, including general information, nutritional support modalities, and enteral nutrition tolerance. Based on the timing of enteral nutrition initiation, patients were divided into the within 24 h enteral nutrition group and the after 24 h enteral nutrition group. Nutritive indicators, nutritional intake, duration of ECMO support, duration of mechanical ventilation duration, and mortality rates were compared between the 2 groups using the two independent sample t test, Mann-Whitney U test, χ2 test and Fisher′s exact test. Results:Among the 43 children, 25 were male and 18 were female, with an age of 47 (18, 97) months. There were no statistically significant differences between the within 24 h enteral nutrition group (21 cases) and the after 24 h enteral nutrition group (22 cases) in terms of age, body mass index Z score, total protein, albumin, hemoglobin levels before ECMO support, duration of ECMO support, duration of mechanical ventilation, length of PICU stay, number of enteral nutrition intolerance events, number of enteral nutrition interruption, or mortality rate (all P>0.05). The protein intake adequacy rate during ECMO support was higher in the within 24 h enteral nutrition group than in the after 24 h enteral nutrition group (0 (0, 21%) vs. 0 (0, 0), U=175.00, P<0.05). Conclusions:Ultra early enteral nutrition is safe for children supported by ECMO. Initiating enteral nutrition within 24 h can increase the proportion of days with adequate protein intake in ECMO children without increasing the occurance of enteral nutrition intolerance or interruptions.