Comparison of the immunogenicity of mRNA-encoded and protein HIV-1 Env-ferritin nanoparticle designs.

Nucleoside-modified mRNA technology has revolutionized vaccine development with the success of mRNA COVID-19 vaccines. We used modified mRNA technology for the design of envelopes (Env) to induce HIV-1 broadly neutralizing antibodies (bnAbs). However, unlike SARS-CoV-2 neutralizing antibodies that are readily made, HIV-1 bnAb induction is disfavored by the immune system because of the rarity of bnAb B cell precursors and the cross-reactivity of bnAbs targeting certain Env epitopes with host molecules, thus requiring optimized immunogen design. The use of protein nanoparticles (NPs) has been reported to enhance B cell germinal center responses to HIV-1 Env. Here, we report our experience with the expression of Env-ferritin NPs compared with membrane-bound Env gp160 when encoded by modified mRNA. We found that well-folded Env-ferritin NPs were a minority of the protein expressed by an mRNA design and were immunogenic at 20 µg but minimally immunogenic in mice at 1 µg dose in vivo and were not expressed well in draining lymph nodes (LNs) following intramuscular immunization. In contrast, mRNA encoding gp160 was more immunogenic than mRNA encoding Env-NP at 1 µg dose and was expressed well in draining LN following intramuscular immunization. Thus, analysis of mRNA expression in vitro and immunogenicity at low doses in vivo are critical for the evaluation of mRNA designs for optimal immunogenicity of HIV-1 immunogens.IMPORTANCEAn effective HIV-1 vaccine that induces protective antibody responses remains elusive. We have used mRNA technology for designs of HIV-1 immunogens in the forms of membrane-bound full-length envelope gp160 and envelope ferritin nanoparticle. Here, we demonstrated in a mouse model that the membrane-bound form induced a better response than envelope ferritin nanoparticle because of higher in vivo protein expression. The significance of our research is in highlighting the importance of analysis of mRNA design expression and low-dose immunogenicity studies for HIV-1 immunogens before moving to vaccine clinical trials.

Isolated ipsilateral ptosis associated with ventral midbrain infarction: a case report and literature review.

Documented cases of ipsilateral ptosis caused by midbrain infarction remain rare. Herein, we present a patient with isolated ipsilateral ptosis that was initially considered to be a consequence of myasthenia gravis but was subsequently attributed to ventral midbrain infarction. We also discuss the possible underlying mechanisms; ipsilateral ptosis in our patient was attributed to selective damage of the levator palpebral muscle branch of the oculomotor nerve. The patient was started on aspirin (200 mg once daily) and atorvastatin (40 mg once daily). Improvement in ptosis occurred from day 5 of admission, and the patient was subsequently discharged. Ptosis disappeared 1 month after onset. This report describes an extremely rare case of ventral midbrain infarction presenting with isolated ipsilateral ptosis. Careful examination, including magnetic resonance imaging, is essential in such patients, especially in those with multiple cerebrovascular risk factors.

Liver Extracellular Vesicles and Particles Enriched ß-Sitosterol Effectively Promote Liver Regeneration in Mice.

Background: The liver's regenerative capacity allows it to repair itself after injury. Extracellular vesicles and particles (EVPs) in the liver's interstitial space are crucial for signal transduction, metabolism, and immune regulation. Understanding the role and mechanism of liver-derived EVPs in regeneration is significant, particularly after partial hepatectomy, where the mechanisms remain unclear. Methods: A 70% hepatectomy model was established in mice, and EVPs were isolated and characterized using electron microscopy, nanocharacterization, and Western blot analysis. Combined metabolomic and transcriptomic analyses revealed ß-sitosterol enrichment in EVPs and activation of the Hedgehog signaling pathway during regeneration. The role of ß-sitosterol in EVPs on the Hedgehog pathway and its targets were identified using qRT-PCR, Western blot analysis. The regulation of carnitine synthesis by this pathway was determined using a dual luciferase assay. The effect of a ß-sitosterol diet on liver regeneration was verified in mice. Results: After 70% hepatectomy, the liver successfully regenerated without liver failure or death. At 24 hours post-surgery, tissue staining showed transient regeneration-associated steatosis (TRAS), with increased Ki67 positivity at 48 hours. EVPs displayed a spherical lipid bilayer structure with particle sizes of 70-130 nm. CD9, CD63, and CD81 in liver-derived EVPs were confirmed. Transcriptomic and metabolomic analyses showed EVPs supplementation significantly promoted carnitine synthesis and fatty acid oxidation. Tissue staining confirmed accelerated TRAS resolution and enhanced liver regeneration with EVP supplementation. Mass spectrometry identified ß-sitosterol in EVPs, which binds to Smo protein, activating the Hedgehog pathway. This led to the nuclear transport of Gli3, stimulating Setd5 transcription and inducing carnitine synthesis, thereby accelerating fatty acid oxidation. Mice with increased ß-sitosterol intake showed faster TRAS resolution and liver regeneration compared to controls. Conclusion: Liver-derived EVPs promote regeneration after partial hepatectomy. ß-sitosterol from EVPs accelerates fatty acid oxidation and promotes liver regeneration by activating Hedgehog signaling pathway.

Astrocytes in the Ventral Hippocampus Bidirectionally Regulate Innate and Stress-Induced Anxiety-Like Behaviors in Male Mice.

The mechanisms of anxiety disorders, the most common mental illness, remain incompletely characterized. The ventral hippocampus (vHPC) is critical for the expression of anxiety. However, current studies primarily focus on vHPC neurons, leaving the role for vHPC astrocytes in anxiety largely unexplored. Here, genetically encoded Ca2+ indicator GCaMP6m and in vivo fiber photometry calcium imaging are used to label vHPC astrocytes and monitor their activity, respectively, genetic and chemogenetic approaches to inhibit and activate vHPC astrocytes, respectively, patch-clamp recordings to measure glutamate currents, and behavioral assays to assess anxiety-like behaviors. It is found that vHPC astrocytic activity is increased in anxiogenic environments and by 3-d subacute restraint stress (SRS), a well-validated mouse model of anxiety disorders. Genetic inhibition of vHPC astrocytes exerts anxiolytic effects on both innate and SRS-induced anxiety-related behaviors, whereas hM3Dq-mediated chemogenetic or SRS-induced activation of vHPC astrocytes enhances anxiety-like behaviors, which are reversed by intra-vHPC application of the ionotropic glutamate N-methyl-d-aspartate receptor antagonists. Furthermore, intra-vHPC or systemic application of the N-methyl-d-aspartate receptor antagonist memantine, a U.S. FDA-approved drug for Alzheimer's disease, fully rescues SRS-induced anxiety-like behaviors. The findings highlight vHPC astrocytes as critical regulators of stress and anxiety and as potential therapeutic targets for anxiety and anxiety-related disorders.

[Mechanism of protective effect of n-butanol extract of Pulsatilla Decoction on vaginal epithelial cells under Candida albicans stimulation through EGFR/MAPK pathway based on transcriptomics].

This study aimed to investigate the protective effect and its underlying mechanism of n-butanol extract of Pulsatilla Decoction(BEPD) containing medicinal serum on vaginal epithelial cells under Candida glabrata stimulation via the epidermal growth factor receptor/mitogen activated protein kinase( EGFR/MAPK) pathway based on transcriptomics. A vulvovaginal candidiasis(VVC) mouse model was established first and transcriptome sequencing was performed for the vaginal mucosa tissues to analyze the gene expression differences among the control, VVC model, and BEPD intervention groups. Simultaneously, BEPD-containing serum and fluconazole-containing serum were prepared. A431 cells were divided into the control, model, blank serum, fluconazole-containing serum, BEPD-containing serum, EGFR agonist and EGFR inhibitor groups. Additionally, in vitro experiments were conducted using BEPD-containing serum, fluconazole-containing serum, and an EGFR agonist and inhibitor to investigate the intervention mechanisms of BEPD on C. glabrata-induced vaginal epithelial cell damage. Cell counting kit-8(CCK-8) assay was utilized to determine the safe concentrations of C. glabrata, drug-containing serum, and compounds on A431 cells. Enzyme-linked immunosorbent assay(ELISA)was employed to measure the expression levels of interleukin(IL)-1ß, IL-6, granulocyte-macrophage colony-stimulating factor(GMCSF), granulocyte CSF(G-CSF), chemokine(C-X-C motif) ligand 20(CCL20), and lactate dehydrogenase(LDH). Gram staining was used to evaluate the adhesion of C. glabrata to vaginal epithelial cells. Flow cytometry was utilized to assess the effect of C.glabrata on A431 cell apoptosis. Based on the transcriptomics results, immunofluorescence was performed to measure the expressions of p-EGFR and p-ERK1/2 proteins, while Western blot validated the expressions of p-EGFR, p-ERK1/2, p-C-Fos, p-P38, Bax and Bcl-2 proteins. Sequencing results showed that compared with the VVC model, BEPD treatment up-regulated 1 075 genes and downregulated 927 genes, mainly enriched in immune-inflammatory pathways, including MAPK. Mechanistically, BEPD significantly reduced the expression of p-EGFR, p-ERK1/2, p-C-Fos and p-P38, as well as the secretion of IL-1ß, IL-6, GM-CSF, G-CSF and CCL20, LDH release induced by C. glabrata, and the adhesion of C. glabrata to A431 cells, suggesting that BEPD exerts a protective effect on vaginal epithelial cells damaged by C. glabrata infection by modulating the EGFR/MAPK axis. In addition, BEPD downregulated the pro-apoptotic protein Bax expression and up-regulated the anti-apoptotic protein Bcl-2 expression, leading to a reduction in C. glabrata-induced cell apoptosis. In conclusion, this study reveals that the intervention of BEPD in C. glabrata-induced VVC may be attributed to its regulation of the EGFR/MAPK pathway, which protects vaginal epithelial cells.

Pyogenic liver abscess in pediatric populations in beijing (2008-2023).

BACKGROUND: Data on pyogenic liver abscess (PLA) of children in China have been limited. We aimed to summarize the clinical feather, microbiological characteristics, management, and outcome of PLA in children. METHOD: We retrospectively reviewed PLA cases from January 2008 to June 2023 at Beijing Children's Hospital. Clinical characteristics, pathogens and management were analyzed. RESULTS: We diagnosed 57 PLA patients in our center. The median onset age was 4.5 years and the male-to-female ratio was 1.6:1. The median diagnostic time was nine days and the median length of stay was 22 days. Twenty-eight patients (49.1%) had predisposing factors, around 71.4% of the patients had malignant hematology and primary immunodeficiency disease. Patients with underlying factors were more likely to have extrahepatic organ involvement (p = 0.024), anemia (p < 0.001), single abscess (p = 0.042), unilateral involvement (p = 0.039), and small size of the abscess (p = 0.008). Twenty-four patients (42.1%) had extrahepatic organ involvement. Pathogens were identified in 17 patients (29.8%), the most common pathogens were Klebsiella pneumoniae and Staphylococcus aureus. The positive rate of metagenomic next-generation sequencing (mNGS) was 87.5% (7/8). On multivariable analysis, the extrahepatic organ involved (p = 0.029) and hepatomegaly (p = 0.025) were two independent factors associated with poor outcomes. CONCLUSIONS: PLA is usually seen in children with predisposing factors. Malignant hematology and primary immunodeficiency disease were the most common underlying diseases. Extrahepatic organ involvement and hepatomegaly are associated with poor prognosis. Increased use of mNGS could be beneficial for identifying pathogens.

Group A Streptococcal meningitis in children: a short case series and systematic review.

BACKGROUND: Group A streptococcal(GAS) meningitis is a severe disease with a high case fatality rate. In the era of increasing GAS meningitis, our understanding about this disease is limited. PURPOSE: To gain a better understanding about GAS meningitis. METHODS: Five new cases with GAS meningitis were reported. GAS meningitis related literatures were searched for systematic review in PUBMED and EMBASE. Case reports and case series on paediatric cases were included. Information on demographics, risk factors, symptoms, treatments, outcomes, and emm types of GAS was summarized. RESULTS: Totally 263 cases were included. Among 100 individuals, 9.9% (8/81) had prior varicella, 11.1% (9/81) had anatomical factors, and 53.2% (42/79) had extracranial infections. Soft tissue infections were common among infants (10/29, 34.5%), while ear/sinus infections were more prevalent in children ≥ 3 years (21/42, 50.0%). The overall case fatality rate (CFR) was 16.2% (12/74). High risk of death was found in patients with shock or systemic complications, young children(< 3 years) and cases related to hematogenic spread. The predominate cause of death was shock(6/8). Among the 163 patients included in case series studies, ear/sinus infections ranged from 21.4 to 62.5%, while STSS/shock ranged from 12.5 to 35.7%, and the CFR ranged from 5.9 to 42.9%. CONCLUSIONS: A history of varicella, soft tissue infections, parameningeal infections and CSF leaks are important clinical clues to GAS in children with meningitis. Young children and hematogenic spread related cases need to be closely monitored for shock due to the high risk of death.

A Prelimbic Cortex-Thalamus Circuit Bidirectionally Regulates Innate and Stress-Induced Anxiety-Like Behavior.

Anxiety-related disorders respond to cognitive behavioral therapies, which involved the medial prefrontal cortex (mPFC). Previous studies have suggested that subregions of the mPFC have different and even opposite roles in regulating innate anxiety. However, the specific causal targets of their descending projections in modulating innate anxiety and stress-induced anxiety have yet to be fully elucidated. Here, we found that among the various downstream pathways of the prelimbic cortex (PL), a subregion of the mPFC, PL-mediodorsal thalamic nucleus (MD) projection, and PL-ventral tegmental area (VTA) projection exhibited antagonistic effects on anxiety-like behavior, while the PL-MD projection but not PL-VTA projection was necessary for the animal to guide anxiety-related behavior. In addition, MD-projecting PL neurons bidirectionally regulated remote but not recent fear memory retrieval. Notably, restraint stress induced high-anxiety state accompanied by strengthening the excitatory inputs onto MD-projecting PL neurons, and inhibiting PL-MD pathway rescued the stress-induced anxiety. Our findings reveal that the activity of PL-MD pathway may be an essential factor to maintain certain level of anxiety, and stress increased the excitability of this pathway, leading to inappropriate emotional expression, and suggests that targeting specific PL circuits may aid the development of therapies for the treatment of stress-related disorders.

A new lignan from Laggera crispata (Vahl) Hepper & J. R. I. Wood.

A new lignan, 9'-O-angelyllariciresinol (1), and 20 known compounds (2-21) were isolated from the petroleum ether fraction of Laggera crispata (Vahl) Hepper & J. R. I. Wood. Their structures were identified by spectral analysis (NMR, IR, UV, and MS). Activity screening showed that compound 5 exhibited significant inhibitory effect on Staphylococcus aureus, while compound 2 exhibited significant inhibitory effect against liver cancer cell line HepG2.

Single-cell topographical profiling of the immune synapse reveals a biomechanical signature of cytotoxicity.

Immune cells have intensely physical lifestyles characterized by structural plasticity and force exertion. To investigate whether specific immune functions require stereotyped mechanical outputs, we used super-resolution traction force microscopy to compare the immune synapses formed by cytotoxic T cells with contacts formed by other T cell subsets and by macrophages. T cell synapses were globally compressive, which was fundamentally different from the pulling and pinching associated with macrophage phagocytosis. Spectral decomposition of force exertion patterns from each cell type linked cytotoxicity to compressive strength, local protrusiveness, and the induction of complex, asymmetric topography. These features were validated as cytotoxic drivers by genetic disruption of cytoskeletal regulators, live imaging of synaptic secretion, and in silico analysis of interfacial distortion. Synapse architecture and force exertion were sensitive to target stiffness and size, suggesting that the mechanical potentiation of killing is biophysically adaptive. We conclude that cellular cytotoxicity and, by implication, other effector responses are supported by specialized patterns of efferent force.

Vaccination induces broadly neutralizing antibody precursors to HIV gp41.

A key barrier to the development of vaccines that induce broadly neutralizing antibodies (bnAbs) against human immunodeficiency virus (HIV) and other viruses of high antigenic diversity is the design of priming immunogens that induce rare bnAb-precursor B cells. The high neutralization breadth of the HIV bnAb 10E8 makes elicitation of 10E8-class bnAbs desirable; however, the recessed epitope within gp41 makes envelope trimers poor priming immunogens and requires that 10E8-class bnAbs possess a long heavy chain complementarity determining region 3 (HCDR3) with a specific binding motif. We developed germline-targeting epitope scaffolds with affinity for 10E8-class precursors and engineered nanoparticles for multivalent display. Scaffolds exhibited epitope structural mimicry and bound bnAb-precursor human naive B cells in ex vivo screens, protein nanoparticles induced bnAb-precursor responses in stringent mouse models and rhesus macaques, and mRNA-encoded nanoparticles triggered similar responses in mice. Thus, germline-targeting epitope scaffold nanoparticles can elicit rare bnAb-precursor B cells with predefined binding specificities and HCDR3 features.

Mature astrocytes as source for astrocyte repopulation after deletion in the medial prefrontal cortex: Implications for depression.

The adult brain retains a high repopulation capacity of astrocytes after deletion, and both mature astrocytes in the neocortex and neural stem cells in neurogenic regions possess the potential to generate astrocytes. However, the origin and the repopulation dynamics of the repopulating astrocytes after deletion remain largely unclear. The number of astrocytes is reduced in the medial prefrontal cortex (mPFC) of patients with depression, and selective elimination of mPFC astrocytes is sufficient to induce depression-like behaviors in rodents. However, whether astrocyte repopulation capacity is impaired in depression is unknown. In this study, we used different transgenic mouse lines to genetically label different cell types and demonstrated that in the mPFC of normal adult mice of both sexes, mature astrocytes were a major source of the repopulating astrocytes after acute deletion induced by an astrocyte-specific toxin, L-alpha-aminoadipic acid (L-AAA), and astrocyte regeneration was accomplished within two weeks accompanied by reversal of depression-like behaviors. Furthermore, re-ablation of mPFC astrocytes post repopulation led to reappearance of depression-like behaviors. In adult male mice subjected to 14-day chronic restraint stress, a well-validated mouse model of depression, the number of mPFC astrocytes was reduced; however, the ability of mPFC astrocytes to repopulate after L-AAA-induced deletion was largely unaltered. Our study highlights a potentially beneficial role for repopulating astrocytes in depression and provides novel therapeutic insights into enhancing local mature astrocyte generation in depression.

[Treatment of Tile type C pelvic ring fracture using orthopedic robot combined with Starr pelvis reduction frame].

OBJECTIVE: To investigate the clinical effect of orthopedic robot combined with Starr pelvic reduction frame in the treatment of Tile type C pelvic ring fracture. METHODS: From October 2019 to May 2021, 14 patients with type C pelvic ring fracture were treated with robotic combined with Starr pelvic reduction frame, including 9 males and 5 females. The age ranged from 33 to 69 years. All the 14 patients had fresh closed fractures without femur, tibia and fibula fracture. Surgery was completed from 4 to 7 d after hospital admission. During the operation, the X-ray carbon bed was used, the pelvic ring was reduced by Starr pelvis reduction frame, and pelvic ring fracture was treated by orthopedic robot. Operation time, bleeding volume, fluoroscopy times of single screw placement, fracture reduction quality, affected limb function and complications were observed. Radiological reduction was evaluated using Matta scoring standard, and clinical efficacy was evaluated by Majeed pelvic function scoring system at the final follow-up. RESULTS: All of 14 patients successfully completed the operation, the operation time was 84 to 141 min, the bleeding volume was 20 to 50 ml, and the fluoroscopy times of single screw insertion was 4 to 9 times. All of 14 patients were followed up for 12 to 24 months. The healing time was 3 to 7 months. No complications such as fracture of internal fixation, screw loosening, infection and nerve injury were found. According to the evaluation criteria of Matta imaging reduction, 9 cases were excellent, 4 cases were good, and 1 case was fair. At the final follow-up, Majeed pelvic function scoring system was used:10 cases were excellent, 4 cases were good. CONCLUSION: The treatment of type C pelvic ring fracture with robotic combined Starr pelvis reduction frame is simple, time-saving, less trauma, less complications and effective.

[Mechanism of n-butanol extract of Pulsatilla Decoction in treating ulcerative colitis by activating BMP signaling pathway].

The study aimed to investigate the therapeutic effects of the n-butanol extract of Pulsatilla Decoction(BEPD) on ulcerative colitis(UC) via the bone morphogenetic protein(BMP) signaling pathway. C57BL/6 mice were divided into six groups: control, model, mesalazine, and BEPD low-, medium-, and high-dose groups. Except for the control group, the rest groups were treated with 3% dextran sulfate sodium(DSS) freely for seven consecutive days to establish the UC mouse model, followed by treatment with different concentrations of BEPD and mesalazine by gavage. The murine body weight and disease activity index(DAI) were recorded. After the mice were sacrificed, their colon tissues were collected for histological analysis. Alcian blue/periodic acid-Schiff(AB/PAS) staining was used to detect the number and mucus secretion status of goblet cells; immunohistochemistry was performed to measure the expression of ki67, cleaved caspase-3, mucin 2(Muc2), and matrix metalloproteinase-9(MMP9) in colon tissues; and immunofluorescence was used to analyze the expression of tight junction proteins in colon tissues, and enzyme linked immunosorbent assay(ELISA) was employed to quantify the levels of tumor necrosis factor-α(TNF-α), interleukin(IL)-1ß, and IL-6. Western blot was conducted to evaluate the expression of BMP pathway-related proteins in mouse colon tissues. Quantitative real-time PCR(qRT-PCR) was performed to measure the expression of genes related to goblet cell differentiation in mouse colon tissues. In addition, this study also examined the protective effect and underlying mechanism of BEPD-containing serum on lipopolysaccharide(LPS)-induced barrier damages in LS174T goblet cells in vitro. The results showed that BEPD significantly alleviated UC symptoms in mice, restored goblet cell diffe-rentiation function, promoted Muc2 secretion and tight junction protein expression, and suppressed inflammatory factor secretion while activating the BMP signaling pathway. Therefore, BEPD may exert its therapeutic effects on UC by activating the BMP signaling pathway, providing a new strategy for drug intervention in UC.

Astrocytic ALKBH5 in stress response contributes to depressive-like behaviors in mice.

Epigenetic mechanisms bridge genetic and environmental factors that contribute to the pathogenesis of major depression disorder (MDD). However, the cellular specificity and sensitivity of environmental stress on brain epitranscriptomics and its impact on depression remain unclear. Here, we found that ALKBH5, an RNA demethylase of N6-methyladenosine (m6A), was increased in MDD patients' blood and depression models. ALKBH5 in astrocytes was more sensitive to stress than that in neurons and endothelial cells. Selective deletion of ALKBH5 in astrocytes, but not in neurons and endothelial cells, produced antidepressant-like behaviors. Astrocytic ALKBH5 in the mPFC regulated depression-related behaviors bidirectionally. Meanwhile, ALKBH5 modulated glutamate transporter-1 (GLT-1) m6A modification and increased the expression of GLT-1 in astrocytes. ALKBH5 astrocyte-specific knockout preserved stress-induced disruption of glutamatergic synaptic transmission, neuronal atrophy and defective Ca2+ activity. Moreover, enhanced m6A modification with S-adenosylmethionine (SAMe) produced antidepressant-like effects. Our findings indicate that astrocytic epitranscriptomics contribute to depressive-like behaviors and that astrocytic ALKBH5 may be a therapeutic target for depression.

Minimizing the ratio of ionizable lipid in lipid nanoparticles for in vivo base editing.

Lipid nanoparticles (LNPs) have gained clinical approval as carriers for both siRNA and mRNA. Among the crucial components of LNPs, ionizable lipids play a pivotal role in determining the efficiency of RNA delivery. In this study, we synthesized a series of ionizable lipids, denoted as HTO, with a higher count of hydroxyl groups compared to SM-102. Remarkably, LNPs based on HTO12 lipid demonstrated comparable mRNA delivery efficiency and biosafety to those based on SM-102. However, the former reduced the ratio of ionizable lipid/total lipids to mRNA in LNPs by 2.5 times compared to SM-102. The HTO12 LNP efficiently encapsulated adenine base editor mRNA and sgRNA targeting Pcsk9, leading to substantial gene editing within the liver of mice and effective reduction of the target protein. Our study underscores that ionizable lipids with multiple hydroxyl groups may facilitate an improved lipid-to-mRNA ratio to minimize the dosage of ionizable lipids for in vivo delivery.

Erratum: [Corrigendum] Chloroquine potentiates the anticancer effect of sunitinib on renal cell carcinoma by inhibiting autophagy and inducing apoptosis.

[This corrects the article DOI: 10.3892/ol.2017.7635.].

Characterization and prevention of flame burns caused by electric bicycle battery chargers: results from a 7-year experience.

OBJECTIVE: With the recent exponential increase in express deliveries across China, the number of patients with flame burns caused by electric bicycle battery chargers (BEBBC) has markedly increased in burn units. In this study, we aimed to characterize BEBBC to systematically explore measures to prevent their occurrence. METHODS: We performed a retrospective chart review of patients with flame burns who visited the Burn Department of Rui Jin Hospital between January 2015 and December 2021. RESULTS: Sixty-three patients with BEBBC and 1412 with types of other flame burn were included in this study. Fifty-six of the 63 BEBBC cases occurred between 9 pm and 7 am. BEBBC incidents involved a higher incidence of group burn in which multiple individuals were affected. Non-local patients with BEBBC were significantly younger than their local counterparts. BEBBC had a higher mortality than types of other flame burn. CONCLUSIONS: The rising incidence of BEBBC calls for greater attention because of the associated high mortality and heavy burden on society. Enacting related legislation, disseminating information to the public, and improving treatment to control infection can help prevent BEBBC, increase its cure rate, and reduce patient mortality.