Japanese Planocerid Flatworms: Difference in Composition of Tetrodotoxin and Its Analogs and the Effects of Ingestion by Toxin-Bearing Fishes in the Ryukyu Islands, Japan.

Tetrodotoxin (TTX), known as pufferfish toxin, is a potent neurotoxin blocking sodium channels in muscle and nerve tissues. TTX has been detected in various taxa other than pufferfish, including marine polyclad flatworms, suggesting that pufferfish toxin accumulates in fish bodies via food webs. The composition of TTX and its analogs in the flatworm Planocera multitentaculata was identical to those in wild grass puffer Takifugu alboplumbeus. Previously, Planocera sp. from Okinawa Island, Japan, were reported to possess high level of TTX, but no information was available on TTX analogs in this species. Here we identified TTX and analogs in the planocerid flatworm using high-resolution liquid chromatography-mass spectrometry, and compared the composition of TTX and analogs with those of another toxic and non-toxic planocerid species. We show that the composition of TTX and several analogs, such as 5,6,11-trideoxyTTX, dideoxyTTXs, deoxyTTXs, and 11-norTTX-6(S)-ol, of Planocera sp. was identical to those of toxic species, but not to its non-toxic counterpart. The difference in the toxin composition was reflected in the phylogenetic relationship based on the mitochondrial genome sequence. A toxification experiment using predatory fish and egg plates of P. multitentaculata demonstrated that the composition of TTX and analogs in wild T. alboplumbeus juveniles was reproduced in artificially toxified pufferfish. Additionally, feeding on the flatworm egg plates enhanced the signal intensities of all TTX compounds in Chelonodon patoca and that of deoxyTTXs in Yongeichthys criniger.

A Case of Severely Impaired Consciousness and Convulsions From Attempted Suicide by Ingesting Triflumizole Emulsion: Clinical Features and Literature Review.

Triflumizole (TFZ) is a fungicide widely used in agriculture to prevent fungal infections of fruits and vegetables. Although it is considered safe for humans and animals, its toxicity profile in humans remains largely unexplored. Here, we describe a case where an individual experienced symptoms suggestive of intoxication after ingesting TFZ emulsion. A 70-year-old man ingested TFZ emulsion (Trifumin emulsionTM) and alcohol in an attempt to commit suicide. He developed a severe disturbance of consciousness, which was not explained by the estimated blood alcohol concentration, and experienced convulsions. We managed this patient with symptomatic treatment, temporary mechanical ventilation, and antiepileptic drugs. He subsequently recovered without any sequelae. We present the first case of acute oral intoxication with TFZ emulsion. Moreover, we review the literature on TFZ-induced organ dysfunction and discuss the possible mechanisms and management of this condition.

Sirtuin 3 Mediated by Spinal cMyc-Enhancer of Zeste Homology 2 Pathway Plays an Important Role in Human Immunodeficiency Virus-Related Neuropathic Pain Model.

BACKGROUND: Clinical data demonstrate that chronic use of opioid analgesics increases neuropathic pain in people living with human immunodeficiency virus (HIV). Therefore, it is important to elucidate the molecular mechanisms of HIV-related chronic pain. In this study, we investigated the role of the transcription factor cMyc, epigenetic writer enhancer of zeste homology 2 (EZH2), and sirtuin 3 (Sirt3) pathway in HIV glycoprotein gp120 with morphine (gp120M)-induced neuropathic pain in rats. METHODS: Neuropathic pain was induced by intrathecal administration of recombinant gp120 with morphine. Mechanical withdrawal threshold was measured using von Frey filaments, and thermal latency using the hotplate test. Spinal expression of cMyc, EZH2, and Sirt3 were measured using Western blots. Antinociceptive effects of intrathecal administration of antisense oligodeoxynucleotide against cMyc, a selective inhibitor of EZH2, or recombinant Sirt3 were tested. RESULTS: In the spinal dorsal horn, gp120M upregulated expression of cMyc (ratio of gp120M versus control, 1.68 ± 0.08 vs 1.00 ± 0.14, P = .0132) and EZH2 (ratio of gp120M versus control, 1.76 ± 0.05 vs 1.00 ± 0.16, P = .006), and downregulated Sirt3 (ratio of control versus gp120M, 1.00 ± 0.13 vs 0.43 ± 0.10, P = .0069) compared to control. Treatment with intrathecal antisense oligodeoxynucleotide against cMyc, GSK126 (EZH2 selective inhibitor), or recombinant Sirt3 reduced mechanical allodynia and thermal hyperalgesia in this gp120M pain model. Knockdown of cMyc reduced spinal EZH2 expression in gp120M treated rats. Chromatin immunoprecipitation (ChIP) assay showed that enrichment of cMyc binding to the ezh2 gene promoter region was increased in the gp120M-treated rat spinal dorsal horn, and that intrathecal administration of antisense ODN against cMyc (AS-cMyc) reversed the increased enrichment of cMyc. Enrichment of trimethylation of histone 3 on lysine residue 27 (H3K27me3; an epigenetic mark associated with the downregulation of gene expression) binding to the sirt3 gene promoter region was upregulated in the gp120M-treated rat spinal dorsal horn; that intrathecal GSK126 reversed the increased enrichment of H3K27me3 in the sirt3 gene promoter. Luciferase reporter assay demonstrated that cMyc mediated ezh2 gene transcription at the ezh2 gene promoter region, and that H3K27me3 silenced sirt3 gene transcription at the gene promoter region. CONCLUSION: These results demonstrated that spinal Sirt3 decrease in gp120M-induced neuropathic pain was mediated by cMyc-EZH2/H3K27me3 activity in an epigenetic manner. This study provided new insight into the mechanisms of neuropathic pain in HIV patients with chronic opioids.

A Novel Method for Creating Heterologous Lethal Antibiotic Producers by Screening from Combi-OGAB Library with Various Promoters in a Biosynthetic Gene Cluster.

In this study, we devised a novel method to create heterologous producers of lethal antibiotics against host bacteria. Heterologous producers cannot be created when antibiotics are toxic to host bacteria. To overcome this challenge, we developed a novel method involving construction of a combinatorial library with various promoters and screening based on the production. To realize this, we utilized Combi-OGAB (Combinatorial Ordered Gene Assembly in Bacillus subtilis), which technology can effectively construct diverse combinatorial library and accelerate screening procedures. B. subtilis and Gramicidin S were selected as the host bacterium and the targeted antibiotic, respectively. The screened producer from Combi-OGAB screening cycles achieved >30-fold productivity over the lethal level. These results suggest that our strategy has the potential to maximize the phenotypic resistance of host bacteria to create heterologous lethal antibiotic producers.

Different effects of crizotinib treatment in two non-small cell lung cancer patients with SDC4::ROS1 fusion variants.

The possibility of stratifying patients according to differences in ROS proto-oncogene 1 (ROS1) fusion partners has been discussed. This study aimed to clarify the clinicopathological differences between two SDC4::ROS1 positive NSCLC cases who had different responses to crizotinib. Cytology and pathology samples from two NSCLC cases with SDC4::ROS1 who were diagnosed and treated with crizotinib at Nihon University Itabashi Hospital were obtained. Case 1 has been well-controlled with crizotinib for over 5 years, but case 2 was worse and overall survival was 19 months. Sequencing analysis of ROS1 fusion genes was performed by reverse-transcription-PCR and Sanger's sequencing methods. In addition, thyroid transcription factor (TTF)-1, ROS-1, Ki67, and phosphorylated extracellular signal-regulated kinase (pERK)1/2 expression were investigated using immunohistochemistry. Sequencing analysis showed SDC4 exon2::ROS1 exon 32 (exon33 deleted) in case 1, and coexistence of SDC4 exon2::ROS1 exon 34 and SDC4 exon2::ROS1 exon35 in case 2. The Ki67 index was not different, but ROS1 and pERK1/2 expression levels tended to be higher in the tumor cells of case 2 than in case 1. Therapeutic response to crizotinib and patients' prognosis in ROS1 rearranged NSCLC may be related to the activation of ROS1 signaling, depending on ROS1 and pERK1/2 overexpression status, even if the ROS1 fusion partner is the same.

Reversible Host-Guest Crosslinks in Supramolecular Hydrogels for On-Demand Mechanical Stimulation of Human Mesenchymal Stem Cells.

Stem cells are regulated not only by biochemical signals but also by biophysical properties of extracellular matrix (ECM). The ECM is constantly monitored and remodeled because the fate of stem cells can be misdirected when the mechanical interaction between cells and ECM is imbalanced. A well-defined ECM model for bone marrow-derived human mesenchymal stem cells (hMSCs) based on supramolecular hydrogels containing reversible host-guest crosslinks is fabricated. The stiffness (Young's modulus E) of the hydrogels can be switched reversibly by altering the concentration of non-cytotoxic, free guest molecules dissolved in the culture medium. Fine-adjustment of substrate stiffness enables the authors to determine the critical stiffness level E* at which hMSCs turn the mechano-sensory machinery on or off. Next, the substrate stiffness across E* is switched and the dynamic adaptation characteristics such as morphology, traction force, and YAP/TAZ signaling of hMSCs are monitored. These data demonstrate the instantaneous switching of traction force, which is followed by YAP/TAZ signaling and morphological adaptation. Periodical switching of the substrate stiffness across E* proves that frequent applications of mechanical stimuli drastically suppress hMSC proliferation. Mechanical stimulation across E* level using dynamic hydrogels is a promising strategy for the on-demand control of hMSC transcription and proliferation.

Clinical course of pathologically confirmed corticobasal degeneration and corticobasal syndrome.

The clinical presentation of corticobasal degeneration is diverse, while the background pathology of corticobasal syndrome is also heterogeneous. Therefore, predicting the pathological background of corticobasal syndrome is extremely difficult. Herein, we investigated the clinical findings and course in patients with pathologically, genetically and biochemically verified corticobasal degeneration and corticobasal syndrome with background pathology to determine findings suggestive of background disorder. Thirty-two patients were identified as having corticobasal degeneration. The median intervals from the initial symptoms to the onset of key milestones were as follows: gait disturbance, 0.0 year; behavioural changes, 1.0 year; falls, 2.0 years; cognitive impairment, 2.0 years; speech impairment, 2.5 years; supranuclear gaze palsy, 3.0 years; urinary incontinence, 3.0 years; and dysphagia, 5.0 years. The median survival time was 7.0 years; 50% of corticobasal degeneration was diagnosed as corticobasal degeneration/corticobasal syndrome at the final presentation. Background pathologies of corticobasal syndrome (n = 48) included corticobasal degeneration (33.3%), progressive supranuclear palsy (29.2%) and Alzheimer's disease (12.5%). The common course of corticobasal syndrome was initial gait disturbance and early fall. In addition, corticobasal degeneration-corticobasal syndrome manifested behavioural change (2.5 years) and cognitive impairment (3.0 years), as the patient with progressive supranuclear palsy-corticobasal syndrome developed speech impairment (1.0 years) and supranuclear gaze palsy (6.0 years). The Alzheimer's disease-corticobasal syndrome patients showed cognitive impairment (1.0 years). The frequency of frozen gait at onset was higher in the corticobasal degeneration-corticobasal syndrome group than in the progressive supranuclear palsy-corticobasal syndrome group [P = 0.005, odds ratio (95% confidence interval): 31.67 (1.46-685.34)]. Dysarthria at presentation was higher in progressive supranuclear palsy-corticobasal syndrome than in corticobasal degeneration-corticobasal syndrome [P = 0.047, 6.75 (1.16-39.20)]. Pyramidal sign at presentation and personality change during the entire course were higher in Alzheimer's disease-corticobasal syndrome than in progressive supranuclear palsy-corticobasal syndrome [P = 0.011, 27.44 (1.25-601.61), and P = 0.013, 40.00 (1.98-807.14), respectively]. In corticobasal syndrome, decision tree analysis revealed that 'freezing at onset' or 'no dysarthria at presentation and age at onset under 66 years in the case without freezing at onset' predicted corticobasal degeneration pathology with a sensitivity of 81.3% and specificity of 84.4%. 'Dysarthria at presentation and age at onset over 61 years' suggested progressive supranuclear palsy pathology, and 'pyramidal sign at presentation and personality change during the entire course' implied Alzheimer's disease pathology. In conclusion, frozen gait at onset, dysarthria, personality change and pyramidal signs may be useful clinical signs for predicting background pathologies in corticobasal syndrome.

The highly developed symbiotic system between the solar-powered nudibranch Pteraeolidia semperi and Symbiodiniacean algae.

The intricate coexistence of Symbiodiniacean algae with a diverse range of marine invertebrates underpins the flourishing biodiversity observed within coral reef ecosystems. However, the breakdown of Symbiodiniaceae-host symbiosis endangers these ecosystems, necessitating urgent study of the symbiotic mechanisms. The symbiosis between nudibranchs and Symbiodiniaceae has been identified as an efficacious model for examining these mechanisms, yet a comprehensive understanding of their histological structures and cellular processes remains elusive. A meticulous histological exploration of the nudibranch Pteraeolidia semperi, employing optical, fluorescence, and electron microscopy, has revealed fine tubules extending to the body surface, with associated epithelial cells having been shown to adeptly encapsulate Symbiodiniaceae intracellularly. By tracing the stages of the "bleaching" in nudibranchs, it was inferred that algal cells, translocated via the digestive gland, are directly phagocytosed and expelled by these epithelial cells. Collectively, these insights contribute substantially to the scholarly discourse on critical marine symbiotic associations.

Tiger attack at a Japanese safari park: a case report.

BACKGROUND: Big cat bites are highly lethal due to the enormous bite force of these animals. This article reviews the morphology of these types of injuries and key points of management through a survival case at a Japanese safari park. CASE PRESENTATION: We report the case of a 26-year-old female keeper who was attacked by a tiger. She was quickly transported to our university hospital by ambulance helicopter. The keeper was severely bitten on the head and face and had wounds all over her body. Craniofacial repair was performed by emergency surgery. She suffered mild facial nerve paralysis and trismus because of being bitten by the tiger and is currently recovering. CONCLUSIONS: A multidisciplinary approach of the severe tiger bites successfully treated a young woman cosmetically and mentally. Animal farms and zoos that keep tigers should take strict measures to avoid direct confrontation with tigers.

Somatosensory pathway dysfunction in patients with amyotrophic lateral sclerosis in a completely locked-in state.

OBJECTIVE: To investigate somatosensory pathway function in patients with amyotrophic lateral sclerosis (ALS) dependent on invasive ventilation and in a completely locked-in state (CLIS). METHODS: We examined median nerve somatosensory evoked potentials (SEPs) in 17 ALS patients in a CLIS, including 11 patients with sporadic ALS, one with familial ALS with genes not examined, four with a Cu/Zn superoxide-dismutase-1 (SOD1) gene variant (Val118Leu, Gly93Ser, Cys146Arg), and one with a fused-in-sarcoma gene variant (P525L). We evaluated N9, N13, N20 and P25, and central conduction time (CCT); the data were compared with those of 73 healthy controls. RESULTS: N20 and N13 were abolished in 12 and 10 patients, and their latencies was prolonged in four and three patients, respectively. The CCT was prolonged in five patients with measurable N13 and N20. Two patients with SOD1 gene mutations had absent or slightly visible N9. Compared to the CCT and latencies and amplitudes of N13 and N20 in the controls, those in the patient cohort were significantly abnormal. CONCLUSIONS: The central somatosensory pathway is severely involved in patients with ALS in a CLIS. SIGNIFICANCE: Our findings suggest that median nerve SEP cannot be utilized for communication in patients with ALS in a CLIS.

The complete mitochondrial genome of Spurilla braziliana MacFarland 1909 (Nudibranchia, Aeolidiidae).

Spurilla braziliana MacFarland 1909 is a morphologically diverse nudibranch found in the Pacific and Western Atlantic. The complete mitochondrial genome of S. braziliana has been constructed using next-generation sequencing technology. The mitochondrial genome is 14,291 bp and contains 13 protein-coding genes, 2 rRNA genes, and 23 tRNA genes. Molecular phylogenetic analysis using the maximum likelihood method revealed that S. braziliana is included in the superfamily Aeolidioidea and forms a monophyletic group with Berghia stephanieae, a nudibranch of the family Aeolidiidae. This study reinforces existing taxonomic insights and provides a basis for further molecular phylogenetic analysis.

A case of intraorbital malignant lymphoma biopsied using an endoscopic transnasal approach.

Background: While most orbital tumors are primary, some are secondary, including extension or invasion from adjacent sites. The diagnosis varies widely, and the treatment strategy depends on the pathological diagnosis. Transcranial and transorbital surgical approaches are typically used. Recently, a transnasal endoscopic approach has emerged as a viable option. We report a case of an intraorbital tumor treated with endoscopic transnasal biopsy and compare the results with those of other surgical approaches. Case Description: A 74-year-old woman visited a nearby hospital due to a right eye protrusion and decreased visual acuity. An intraorbital tumor was detected and the patient was referred to our hospital. Head computed tomography revealed a mass along the posterior wall of the right orbital apex. Contrast-enhanced magnetic resonance imaging showed a 37-mm lesion with a uniform contrast effect and no intracranial extension. Intraorbital lymphoma was considered a differential diagnosis, and a biopsy was performed using an endoscopic transnasal approach. The pathological diagnosis was B-cell lymphoma, and chemotherapy was administered. Conclusion: The endoscopic transnasal approach for intraorbital tumors is less invasive, highly cosmetic, and useful, especially for medial and inferior orbital lesions.

Clinical Efficacy of Pre-Hospital Electrocardiogram Transmission in Patients Undergoing Primary Percutaneous Coronary Intervention for ST-Segment Elevation Myocardial Infarction.

Rapid reperfusion by primary percutaneous coronary intervention (pPCI) is an established strategy for the treatment of patients with ST-segment elevation myocardial infarction (STEMI). Pre-hospital electrocardiogram (PH-ECG) transmission by the emergency medical services (EMS) facilitates timely reperfusion in these patients. However, evidence regarding the clinical benefits of PH-ECG in individual hospitals is limited.This retrospective, observational study investigated the clinical efficacy of PH-ECG in STEMI patients who underwent pPCI. Of a total of 382 consecutive STEMI patients, 237 were enrolled in the study and divided into 2 groups: a PH-ECG group (n = 77) and non-PH-ECG group (n = 160). Door-to-balloon time (D2BT) was significantly shorter in the PH-ECG group (66 [52-80] min), compared to the non-PH-ECG group (70 [57-88] minutes, P = 0.01). The 30-day all-cause mortality rate was 6% in the PH-ECG group, which was significantly lower than that in the non-PH-ECG group (16%) (P = 0.037, hazard ratio [HR]: 0.38, 95% CI: 0.15-0.98). This trend was particularly evident in severely ill patients when stratified by GRACE score.The use of PH-ECG improved the survival rate of STEMI patients undergoing pPCI due to the improved pre-arrival preparation based on the EMS information. Coordination between EMS and PCI-capable institutes is essential for the management of PH-ECG.

Prospective exosome-focused translational research for afatinib (EXTRA) study of patients with nonsmall cell lung cancer harboring EGFR mutation: an observational clinical study.

Background: The exosome-focused translational research for afatinib (EXTRA) study is the first trial to identify novel predictive biomarkers for longer treatment efficacy of afatinib in patients with epidermal growth factor receptor (EGFR) mutation-positive nonsmall cell lung cancer (NSCLC) via a comprehensive association study using genomic, proteomic, epigenomic, and metabolomic analyses. Objectives: We report details of the clinical portion prior to omics analyses. Design: A prospective, single-arm, observational study was conducted using afatinib 40 mg/day as an initial dose in untreated patients with EGFR mutation-positive NSCLC. Dose reduction to 20 mg every other day was allowed. Methods: Progression-free survival (PFS), overall survival (OS), and adverse events (AEs) were evaluated. Results: A total of 103 patients (median age 70 years, range 42-88 years) were enrolled from 21 institutions in Japan between February 2017 and March 2018. After a median follow-up of 35.0 months, 21% remained on afatinib treatment, whereas 9% had discontinued treatment because of AEs. The median PFS was 18.4 months, with a 3-year PFS rate of 23.3%. The median afatinib treatment duration in patients with final doses of 40 (n = 27), 30 (n = 23), and 20 mg/day (n = 35), and 20 mg every other day (n = 18) were 13.4, 15.4, 18.8, and 18.3 months, respectively. The median OS was not reached, with a 3-year OS rate of 58.5%. The median OS in patients who did (n = 25) and did not (n = 78) receive osimertinib during the entire course of treatment were 42.4 months and not reached, respectively (p = 0.654). Conclusions: As the largest prospective study in Japan, this study confirmed favorable OS following first-line afatinib in patients with EGFR mutation-positive NSCLC in a real-world setting. Further analysis of the EXTRA study is expected to identify novel predictive biomarkers for afatinib. Trial registration: UMIN-CTR identifier (UMIN000024935, https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_his_list.cgi?recptno=R000028688.

Anti-synthetase syndrome-associated interstitial lung disease possibly caused by atezolizumab in a patient with lung adenocarcinoma: a case report.

BACKGROUND: Anti-aminoacyl-tRNA synthetase (ARS) antibody-positive patients present with a variety of symptoms, including interstitial lung disease (ILD), which is termed anti-synthetase syndrome (ASS). But it is rare that ASS-ILD is considered an immune-related adverse event after the use of immune checkpoint inhibitors (ICIs). CASE PRESENTATION: A 47-year-old male with advanced lung adenocarcinoma was treated with platinum and ICI combination immunotherapy and was followed up as an outpatient. Nine months after the start of treatment, he developed a fever and cough, and imaging findings showed lung consolidations in the bilateral lower lung fields. The patient was positive for anti- ARS antibodies and was considered to have developed ASS-ILD due to ICIs remitted with steroid therapy. The patient was found to be positive for anti-ARS antibodies before ICI administration, and the antibody titer was elevated compared to that before ICI administration. CONCLUSIONS: The examination of anti-ARS antibodies pior to the administration of ICIs may be useful in predicting the development of ASS-ILD.

Risk factors for postoperative anastomotic leakage after repair of esophageal atresia: a retrospective nationwide database study.

PURPOSE: Postoperative anastomotic leakage is the most frequent short-term complication of esophageal atresia repair in neonates. We conducted this study using a nationwide surgical database in Japan to identify the risk factors for anastomotic leakage in neonates undergoing esophageal atresia repair. METHODS: Neonates diagnosed with esophageal atresia between 2015 and 2019 were identified in the National Clinical Database. Postoperative anastomotic leakage was compared among patients to identify the potential risk factors, using univariate analysis. Multivariable logistic regression analysis included sex, gestational age, thoracoscopic repair, staged repair, and procedure time as independent variables. RESULTS: We identified 667 patients, with an overall leakage incidence of 7.8% (n = 52). Anastomotic leakage was more likely in patients who underwent staged repairs than in those who did not (21.2% vs. 5.2%, respectively) and in patients with a procedure time > 3.5 h than in those with a procedure time < 3.5 h (12.6% vs. 3.0%, respectively; p < 0.001). Multivariable logistic regression analysis identified staged repair (odds ratio [OR] 4.89, 95% confidence interval [CI] 2.22-10.16, p < 0.001) and a longer procedure time (OR 4.65, 95% CI 2.38-9.95, p < 0.001) as risk factors associated with postoperative leakage. CONCLUSION: Staged procedures and long operative times are associated with postoperative anastomotic leakage, suggesting that leakage is more likely after complex esophageal atresia repair and that such patients require refined treatment strategies.

Determinants of Microbial-Derived Dissolved Organic Matter Diversity in Antarctic Lakes.

Identifying drivers of the molecular composition of dissolved organic matter (DOM) is essential to understand the global carbon cycle, but an unambiguous interpretation of observed patterns is challenging due to the presence of confounding factors that affect the DOM composition. Here, we show, by combining ultrahigh-resolution mass spectrometry and nuclear magnetic resonance spectroscopy, that the DOM molecular composition varies considerably among 43 lakes in East Antarctica that are isolated from terrestrial inputs and human influence. The DOM composition in these lakes is primarily driven by differences in the degree of photodegradation, sulfurization, and pH. Remarkable molecular beta-diversity of DOM was found that rivals the dissimilarity between DOM of rivers and the deep ocean, which was driven by environmental dissimilarity rather than the spatial distance. Our results emphasize that the extensive molecular diversity of DOM can arise even in one of the most pristine and organic matter source-limited environments on Earth, but at the same time the DOM composition is predictable by environmental variables and the lakes' ecological history.

Does early excision or skin grafting of severe burns improve prognosis? A retrospective cohort study.

The present study aimed to investigate the appropriate timing of excision or skin grafting of burn wounds in patients with severe burns. We retrospectively analyzed data from the Diagnosis Procedure Combination Database, a nationwide inpatient database in Japan. Patients with severe burns (burn index ≥10) who underwent excision or skin grafting within 7 days from September 2010 to March 2019 were included. We defined the early surgery group as patients who underwent excision or skin grafting within 2 days of admission and the delayed surgery group as those who underwent surgery within 3-7 days of admission. Propensity score matching was used to compare the in-hospital mortality between the two groups, yielding a cohort of 389 pairs. A total of 2362 eligible patients were categorized into the early surgery group (n = 626) and delayed surgery group (n = 1736). The overall in-hospital mortality was 19.6%. In-hospital mortality did not differ significantly between the early surgery (15.9%) and the delayed surgery groups (17.2%; p = 0.70). These results suggest that excision or skin grafting within 2 days of admission was not associated with improved in-hospital mortality compared with surgery thereafter for patients with severe burns.