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 compare the clinical features of severe Mycoplasma pneumoniae pneumonia (SMPP) in pediatric intensive care units (PICU) before and after the COVID-19 pandemic.Methods:A retrospective study was conducted in the PICU of Shanghai Children's Hospital. Clinical and laboratory data were collected from medical records of SMPP patients admitted to the PICU before (January to December 2019) and after (March 2023 to February 2024) the COVID-19 pandemic. Patients admitted in 2019 were categorized as the pre-COVID-19 group, while those admitted in 2023-2024 were classified as the post-COVID-19 group.Results:A total of 287 children with SMPP were included, comprising 155 males and 132 females. The pre-pandemic group consisted of 180 cases, while the post-pandemic group had 107 cases. Macrolide-resistant Mycoplasma pneumoniae (MRMP) was detected in 270 cases (94.1%), with no significant difference in MRMP prevalence between the two groups [101 cases (94.4%) vs. 169 cases (93.9%), Z= 0.031, P = 0.861]. The median age of the post-pandemic group was higher than that of the pre-pandemic group [72 (42, 108) months vs. 42 (24, 68) months, Z= 6.438, P < 0.001].Comparisons of complications between the post-pandemic and pre-pandemic groups were as follows: pleural effusion [20 cases (18.7%) vs. 81 cases (45.0%), χ2=20.365, P< 0.001], shock [4 cases (3.7%) vs. 79 cases (43.9%), χ2=52.628, P< 0.001], gastrointestinal dysfunction [2 cases (1.9%) vs. 24 cases (13.3%), χ 2=9.359, P=0.002], liver dysfunction [9 cases (8.4%) vs. 46 cases (25.6%), χ2=12.733, P< 0.001], and renal injury [0 cases vs. 10 cases (5.6%), P=0.015].There was no significant difference in the incidence of respiratory failure [102 cases (95.3%) vs. 172 cases (95.6%), χ2=0.008, P=0.928]. However, the number of cases requiring high-flow oxygen therapy and mechanical ventilation was significantly lower in the post-pandemic group compared to the pre-pandemic group [14 cases (13.3%) vs. 48 cases (26.7%), 21 cases (20.3%) vs. 122 cases (67.8%), all P<0.05].The time from symptom onset to the initiation of tetracycline/quinolone therapy was shorter in the post-pandemic group compared to the pre-pandemic group [7 (3, 10) days vs. 9 (6.3, 11) days, χ2=-3.565, P< 0.001]. The proportion of patients who had already received tetracycline/quinolone therapy before admission to the PICU was significantly higher in the post-pandemic group compared to the pre-pandemic group [25 cases (23.4%) vs. 2 cases (1.1%), χ 2=10.009, P=0.002].Both the total hospital stay and PICU stay were shorter in the post-pandemic group compared to the pre-pandemic group [10.0 (8.0, 14.0) days vs. 15.5 (12.0, 22.0) days, 5 (3.0, 8.0) days vs. 7.0 (5.0, 10.0) days, all P=0.000]. All 7 deaths occurred in the pre-pandemic group, including 5 cases with co-infections and 2 cases with underlying diseases. Conclusions:In the post-COVID-19 era, SMPP cases in the PICU were predominantly observed in children over 5 years old, with a lower incidence of shock, gastrointestinal disorders, liver injury, and kidney injury compared to the pre-pandemic period. Patients with macrolide-resistant Mycoplasma pneumoniae who received timely treatment with tetracycline/quinolones exhibited favorable outcomes.

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.

Obstructive sleep apnea(OSA)is a dis-order characterized by chronic intermittent hypoxia and sleep fragmentation,usually manifested by ob-struction of the upper respiratory tract,resulting in sleep fragmentation,intermittent hypoxia,and hy-percapnia.OSA and significant comorbidities are as-sociated with perioperative complications.Opioids,as the most commonly used pain relievers,may fur-ther affect perioperative pain management in OSA and comorbidities.Studies have shown that OSA patients are more susceptible to the respiratory de-pressant effects of opioids.OSA also increases the risk of opioid-induced respiratory depression.There-fore,understanding the effects and mechanisms of opioids on OSA has important clinical significance for optimizing drug use,improving prognosis,and reducing respiratory adverse events.This article aims to review the effects of opioids on OSA and their relationship.

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.

Obstructive sleep apnea(OSA)is a dis-order characterized by chronic intermittent hypoxia and sleep fragmentation,usually manifested by ob-struction of the upper respiratory tract,resulting in sleep fragmentation,intermittent hypoxia,and hy-percapnia.OSA and significant comorbidities are as-sociated with perioperative complications.Opioids,as the most commonly used pain relievers,may fur-ther affect perioperative pain management in OSA and comorbidities.Studies have shown that OSA patients are more susceptible to the respiratory de-pressant effects of opioids.OSA also increases the risk of opioid-induced respiratory depression.There-fore,understanding the effects and mechanisms of opioids on OSA has important clinical significance for optimizing drug use,improving prognosis,and reducing respiratory adverse events.This article aims to review the effects of opioids on OSA and their relationship.

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.

In November 2023, the seventh National Nucleic Acid Vaccine Conference was held to deeply discuss the immune mechanism, safety risks, advantages, and disadvantages of nucleic acid vaccines, and review the safety and effectiveness of COVID-19 vaccines developed by nucleic acid vaccine technology. Some prospectives were formed in the meeting that in the post-pandemic era, nucleic acid vaccine technology will play a role in the following areas: dealing with pathogens that are difficult to be prevented by traditional vaccines, promoting the upgrading of traditional live attenuated vaccines, contributing to the development of multivalent and combined vaccines, and rapid response to emerging and re-emerging infectious diseases. These views point out the direction for the future development of nucleic acid vaccine technology.

microRNA(miRNA)is a 22nt long sin-gle-stranded non-coding RNA that is involved in a variety of physiological and pathological processes.Bronchial asthma is a heterogeneous disease,and airway inflammation is one of the important mecha-nisms of its pathogenesis.Asthma can be classified into different types based on the different immune mechanisms involved in its pathogenesis,and the mechanism of airway inflammation also varies be-tween different types of asthma.This article reviews the research progress of miRNA in asthma airway inflammation and endotype,and explores the pathogenesis and treatment prospects of miRNA in asthma airway inflammation and endotype.

Objective:To investigate the efficacy and safety of tocilizumab in the treatment of critically ill children with acute necrotizing encephalopathy (ANE).Methods:It is a retrospective cohort study. The children with ANE admitted to the pediatric intensive care unit of 4 Chinese tertiary hospitals from December 2022 to November 2023 were divided into conventional treatment group and tocilizumab group, and the comparison between groups was performed by using Mann ‐ Whitney U test or Chi-square test. Results:Among 21 cases of severe ANE, there were 11 males with the onset age of 65 (27, 113) months. The duration from onset to PICU admission was 2 (1, 2) days. There were 13 cases of ultra-high fever (greater than 40 ℃), including 18 cases of convulsions, and 19 cases with a GCS score of less than 8 points. The causative agent was novel coronavirus Omicron in 7 cases and influenza A in 14 cases. All cases had central respiratory failure requiring mechanical ventilation. Of the 21 cases, 18 were shock, 15 were coagulopathy, 10 were kidney injury and 13 were liver dysfunction. Of these hospitalized patients, 8 children with ANE were treated with tocilizumab. Eight cases received continuous blood purification (CBP) treatment, 5 of them were combined with plasmapheresis. Serum cytokine levels were elevated in 21 children with ANE, including (interleukin, IL)-6 and IL-8 (61 (22, 1 513) and 68 (5, 296) ng/L). There were 14 cases (67%) deaths, including 11 cases in the conventional treatment group and 3 cases in the tocilizumab group. There was no significant difference in the mortality rate between the two groups ( P=0.056). Tocilizumab-related rash or other adverse events were not observed. Conclusions:The motality of critically ill ANE patients was high. The combination of Tocilizumab with conventional treatment did not reduce the motality of severe ANE patients, and no adverse reactions of tocilizumab were observed.