Objective: To investigate the association between monocyte to high-density lipoprotein cholesterol ratio (MHR) and periodontitis and to provide new epidemiologic evidence on the factors affecting periodontitis. Methods: Data on MHR, periodontitis, and other covariates were selected from the NHANES(National Health and Nutrition Examination) database for 3 cycles of subjects in 2009-2010, 2011-2012, and 2013-2014, and a total of 8 456 study subjects were included. The study participants were grouped according to the prevalence of periodontitis (presence or absence), and three regression models (unadjusted covariates, partially adjusted covariates, and fully adjusted covariates) were constructed to analyze the relationship between MHR and periodontitis by using a weighted logistic regression method with stepwise adjustment for confounders. MHR was divided into four groups from Q1 to Q4 according to quartiles from small to large for weighted trend analysis, and the nonlinear relationship between MHR (continuous) and periodontitis was analyzed using a restricted cubic spline with subgroup analysis and sensitivity analysis. Results: All three logistic regression models showed a positive association between MHR and periodontitis (OR = 2.92, 95%CI: 2.14-3.99, P<0.001 (not adjusted); OR = 1.97, 95%CI: 1.39-2.78, P<0.001 (partially adjusted); OR = 1.62, 95%CI: 1.10-2.39, P = 0.017 (fully adjusted)). Trend analysis showed a significantly higher risk of developing periodontitis in the Q4 group compared with the Q1 group in both single (OR = 1.92, 95% CI: 1.58-2.33, P<0.001) and multifactorial analyses (OR = 1.30, 95% CI: 1.03-1.64, P = 0.029). Restricted cubic spline results did not support a nonlinear relationship between MHR and periodontitis (P for nonlinear>0.05), subgroup analysis showed no significant interaction between the covariates and MHR (P>0.05), and sensitivity analysis also showed a positive correlation between MHR and periodontitis (OR = 1.67, 95%CI: 1.31-2.14, P<0.001). Conclusion MHR is positively associated with the risk of developing periodontitis.

Objective: To identify an optimal back-flush solution for leukocyte-depleted filters that maximizes peripheral blood mononuclear cell (PBMC) recovery with high viability, long-term storage stability, and sterility of the harvested residues, thereby providing a clinically translatable strategy. Methods: Three sterile bag-packaged solutions—Saline, Solvent, and Hanks' balanced salt solution (HBSS)—were used to back-flush randomly assigned leukocyte-depleted filters. Nucleated cell recovery rate and viability of the harvested residues were compared. The optimal solution identified was applied to an expanded sample set. PBMC viability and yield were evaluated after 1h vs 48h storage of the residues. PBMCs isolated from the residues were cryopreserved in liquid nitrogen for 1 month, followed by post-thaw comparisons of viability and T-cell expansion capacity. Results: The Solvent group achieved the highest and most consistent nucleated cell recovery rate. Post-flush recovery rate from filters after 400 mL whole blood processing was (21.3±1.6)% for the Solvent group, significantly higher than Saline group (19.2±6.3)% and HBSS group (11.2±5.0)%, with residues from all groups maintaining viability >90%. No biologically significant difference in residue viability was observed between 48h vs 1h storage groups (93.3±2.3)% vs (95.7±1.8)%). PBMC recovery rates from residues showed no statistical difference between 48h vs 1h storage groups [(48.2%±9.5%)vs (40.41%±8.35%), P>0.05], with (17.7±2.6)×10 cells. After 1-month cryopreservation and 10-day expansion, PBMCs isolated from 48-hour-stored residues retained (91.2±3.2)% viability and achieved a (61.9±15.9)-fold expansion. Conclusion: The bag-packaged Solvent, as a back-flush solution, enables sterile acquisition of leukocyte-depleted filter residues through closed-system tubing connections. These residues maintained PBMC viability and recovery rates after 48h storage at 2℃-8℃, with post-cryopreservation (1-month liquid nitrogen) viability and expansion capacity remaining stable. This protocol complies with blood bank regulatory criteria, addresses the concerns about the infectious window period in cell therapy raw materials, and provides a clinically translatable strategy for PBMC-based applications.

Background: Diabetes-induced testicular damage (DITD) is a common complication of diabetes. We investigated underlying mechanism of retinoblastoma-binding protein 6 (Rbbp6)-mediated brain and muscle ARNT-like 1 (Bmal1) ubiquitination in modulating ferroptosis in DITD. Methods: Spermatogenic cell apoptosis and viability were measured by flow cytometry and cell counting kit 8 (CCK-8), respectively. The impact of Rbbp6 and Bmal1 on ferroptosis was assessed by determining expression of ferroptosis markers glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11), and levels of malondialdehyde (MDA), glutathione (GSH), iron, and lipid peroxidation. Co-immunoprecipitation was performed to determine the interaction between Rbbp6 and Bmal1, as well as the ubiquitination level of Bmal1. The expression levels of Rbbp6, Bmal1, Yes-associated protein 1 (YAP1), ferroptosis markers, and testicular steroidogenic enzymes were tested by Western blot. Results: Bmal1 protein expression was significantly downregulated, while Rbbp6 was upregulated in DITD mouse model and high glucose (HG)-induced GC-1 spg cells. Overexpression of Bmal1 improved testicular injury in diabetic mice, reduced 4-hydroxynonenal (4-HNE), MDA, iron levels, and increased expression levels of GPX4, SLC7A11, GSH, as well as testicular steroidogenic enzymes. Rbbp6 decreased Bmal1 level through promoting its ubiquitination. Meanwhile, Rbbp6 knockdown inhibited the ferroptosis of HG-induced GC-1 spg cells, which were abolished by silencing Bmal1. In addition, knockdown of YAP1 or treatment with ferroptosis inducer erastin blocked the above effects caused by Bmal1 overexpression. Conclusion Rbbp6-mediated Bmal1 ubiquitination suppressed YAP1 pathway, promoting ferroptosis in DITD. This study highlighted Rbbp6/Bmal1/YAP1 axis as a potential therapeutic target for mitigating DITD.

Background: Diabetes-induced testicular damage (DITD) is a common complication of diabetes. We investigated underlying mechanism of retinoblastoma-binding protein 6 (Rbbp6)-mediated brain and muscle ARNT-like 1 (Bmal1) ubiquitination in modulating ferroptosis in DITD. Methods: Spermatogenic cell apoptosis and viability were measured by flow cytometry and cell counting kit 8 (CCK-8), respectively. The impact of Rbbp6 and Bmal1 on ferroptosis was assessed by determining expression of ferroptosis markers glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11), and levels of malondialdehyde (MDA), glutathione (GSH), iron, and lipid peroxidation. Co-immunoprecipitation was performed to determine the interaction between Rbbp6 and Bmal1, as well as the ubiquitination level of Bmal1. The expression levels of Rbbp6, Bmal1, Yes-associated protein 1 (YAP1), ferroptosis markers, and testicular steroidogenic enzymes were tested by Western blot. Results: Bmal1 protein expression was significantly downregulated, while Rbbp6 was upregulated in DITD mouse model and high glucose (HG)-induced GC-1 spg cells. Overexpression of Bmal1 improved testicular injury in diabetic mice, reduced 4-hydroxynonenal (4-HNE), MDA, iron levels, and increased expression levels of GPX4, SLC7A11, GSH, as well as testicular steroidogenic enzymes. Rbbp6 decreased Bmal1 level through promoting its ubiquitination. Meanwhile, Rbbp6 knockdown inhibited the ferroptosis of HG-induced GC-1 spg cells, which were abolished by silencing Bmal1. In addition, knockdown of YAP1 or treatment with ferroptosis inducer erastin blocked the above effects caused by Bmal1 overexpression. Conclusion Rbbp6-mediated Bmal1 ubiquitination suppressed YAP1 pathway, promoting ferroptosis in DITD. This study highlighted Rbbp6/Bmal1/YAP1 axis as a potential therapeutic target for mitigating DITD.

Background: Diabetes-induced testicular damage (DITD) is a common complication of diabetes. We investigated underlying mechanism of retinoblastoma-binding protein 6 (Rbbp6)-mediated brain and muscle ARNT-like 1 (Bmal1) ubiquitination in modulating ferroptosis in DITD. Methods: Spermatogenic cell apoptosis and viability were measured by flow cytometry and cell counting kit 8 (CCK-8), respectively. The impact of Rbbp6 and Bmal1 on ferroptosis was assessed by determining expression of ferroptosis markers glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11), and levels of malondialdehyde (MDA), glutathione (GSH), iron, and lipid peroxidation. Co-immunoprecipitation was performed to determine the interaction between Rbbp6 and Bmal1, as well as the ubiquitination level of Bmal1. The expression levels of Rbbp6, Bmal1, Yes-associated protein 1 (YAP1), ferroptosis markers, and testicular steroidogenic enzymes were tested by Western blot. Results: Bmal1 protein expression was significantly downregulated, while Rbbp6 was upregulated in DITD mouse model and high glucose (HG)-induced GC-1 spg cells. Overexpression of Bmal1 improved testicular injury in diabetic mice, reduced 4-hydroxynonenal (4-HNE), MDA, iron levels, and increased expression levels of GPX4, SLC7A11, GSH, as well as testicular steroidogenic enzymes. Rbbp6 decreased Bmal1 level through promoting its ubiquitination. Meanwhile, Rbbp6 knockdown inhibited the ferroptosis of HG-induced GC-1 spg cells, which were abolished by silencing Bmal1. In addition, knockdown of YAP1 or treatment with ferroptosis inducer erastin blocked the above effects caused by Bmal1 overexpression. Conclusion Rbbp6-mediated Bmal1 ubiquitination suppressed YAP1 pathway, promoting ferroptosis in DITD. This study highlighted Rbbp6/Bmal1/YAP1 axis as a potential therapeutic target for mitigating DITD.

Background: Diabetes-induced testicular damage (DITD) is a common complication of diabetes. We investigated underlying mechanism of retinoblastoma-binding protein 6 (Rbbp6)-mediated brain and muscle ARNT-like 1 (Bmal1) ubiquitination in modulating ferroptosis in DITD. Methods: Spermatogenic cell apoptosis and viability were measured by flow cytometry and cell counting kit 8 (CCK-8), respectively. The impact of Rbbp6 and Bmal1 on ferroptosis was assessed by determining expression of ferroptosis markers glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11), and levels of malondialdehyde (MDA), glutathione (GSH), iron, and lipid peroxidation. Co-immunoprecipitation was performed to determine the interaction between Rbbp6 and Bmal1, as well as the ubiquitination level of Bmal1. The expression levels of Rbbp6, Bmal1, Yes-associated protein 1 (YAP1), ferroptosis markers, and testicular steroidogenic enzymes were tested by Western blot. Results: Bmal1 protein expression was significantly downregulated, while Rbbp6 was upregulated in DITD mouse model and high glucose (HG)-induced GC-1 spg cells. Overexpression of Bmal1 improved testicular injury in diabetic mice, reduced 4-hydroxynonenal (4-HNE), MDA, iron levels, and increased expression levels of GPX4, SLC7A11, GSH, as well as testicular steroidogenic enzymes. Rbbp6 decreased Bmal1 level through promoting its ubiquitination. Meanwhile, Rbbp6 knockdown inhibited the ferroptosis of HG-induced GC-1 spg cells, which were abolished by silencing Bmal1. In addition, knockdown of YAP1 or treatment with ferroptosis inducer erastin blocked the above effects caused by Bmal1 overexpression. Conclusion Rbbp6-mediated Bmal1 ubiquitination suppressed YAP1 pathway, promoting ferroptosis in DITD. This study highlighted Rbbp6/Bmal1/YAP1 axis as a potential therapeutic target for mitigating DITD.

Objective To clone and express the heat shock cognate protein 20 (SjHsc20) of Schistosoma japonicum, and to preliminarily investigate its biological characteristics. Methods The target fragment of the SjHsc20 gene was amplified using PCR assay and cloned into the pET-28a(+) expression plasmid to generate the recombinant expression vector pET-28a(+)-SjH-sc20, which was then transformed into Escherichia coli BL21 (DE3) competent cells. The recombinant SjHsc20 (rSjHsc20) protein was induced with isopropyl β-D-thiogalactopyranoside (IPTG) and purified, and the expression of the rSjHsc20 protein was checked with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The immunogenicity of the rSjHsc20 protein was detected using Western blotting, and the transcriptional levels of SjHsc20 were quantified in S. japonicum worms at different developmental stages and in male and female adult worms using real-time quantitative PCR (RT-qPCR) assay. Thirty female BALB/c mice at ages 6 to 8 weeks were divided into three groups, including the rSjHsc20 immunization group, the PBS control group, and the ISA 206 adjuvant group, of 10 mice in each group. Mice in the rSjHsc20 immunization group were subcutaneously immunized with 20 μg rSjHsc20 on days 1, 15 and 31, and animals in the PBS control group were subcutaneously injected with the same volume of PBS on days 1, 15 and 31, while mice in the ISA 206 adjuvant group were subcutaneously immunized with the same volume of ISA 206 adjuvant on days 1, 15 and 31, respectively. All mice in each group were infected with (40 ± 2) S. japonicum cercariae via the abdomen 14 day following the last immunization. Levels of serum specific IgG and its subtypes IgG1 and IgG2 antibodies against rSjHsc20, and the serum titers of anti-rSjHsc20 antibody were detected in mice using indirect enzyme-linked immunosorbent assay (ELISA). All mice were sacrifice 42 days post-infection, and S. japonicum worms were collected from the hepatic portal vein and counted. The eggs per gram (EPG), worm burden reductions and egg burden reductions were estimated to evaluate the protective efficacy of the rSjHsc20 protein. Results The SjHsc20 gene had an open reading frame (ORF) with 756 bp in length and encoded 252 amino acids, and the rSjHsc20 protein had a relative molecular mass of approximately 29 kDa. The rSjHsc20 protein was recognized by the serum of mice infected with S. japonicum and the serum of mice immunized with the rSjHsc20 protein, indicating that rSjHsc20 had a good immunogenicity. There was a significant difference in the transcriptional levels of the SjHsc20 gene among the 7-day (1.001 4 ± 0.065 7), 12-day (2.268 3 ± 0.129 2), 21-day (1.378 5 ± 0.160 4), 28-day (1.196 4 ± 0.244 0), 35-day (1.646 3 ± 0.226 1), 42-day worms of S. japonicum (1.758 0 ± 0.611 1) (F = 38.45, P < 0.000 1), and the transcriptional level of the SjHsc20 gene was higher in the 12-day worms than in worms at other developmental stages (all P values < 0.000 1). The serum levels of anti-rSjHsc20 IgG antibody were 0.106 6 ± 0.010 7, 0.108 3 ± 0.010 4, and 0.553 2 ± 0.069 1 in the PBS control group, ISA 206 adjuvant group, and rSjHsc20 immunization group following the last immunization, respectively, and the serum levels of IgG1 antibody were 0.137 3 ± 0.054 0, 0.181 1 ± 0.096 8, and 1.765 8 ± 0.221 1, while the levels of IgG2a antibody were 0.280 3 ± 0.197 6, 0.274 0 ± 0.146 3, and 1.560 4 ± 0.106 0, respectively. There were significant differences in the serum levels of anti-rSjHsc20 IgG (F = 397.70, P < 0.000 1), IgG1 (F = 401.00, P < 0.000 1) and IgG2a antibodies (F = 229.70, P < 0.000 1) among the three groups, and the serum levels of anti-rSjHsc20 IgG, IgG1 and IgG2a antibodies were higher in the rSjHsc20 immunization group than in the PBS control group and the ISA 206 adjuvant group (all P values < 0.000 1). There was a significant difference in the IgG1/IgG2a ratio among the rSjHsc20 immunization group (1.177 2 ± 0.143 6), the PBS control group (0.428 4 ± 0.199 8) and the ISA 206 adjuvant group (0.559 9 ± 0.181 1) (F = 43.97, P < 0.000 1), and the IgG1/IgG2a ratio was > 1 in the rSjHsc20 immunization group, which was higher than in the PBS control group and the ISA 206 adjuvant group (both P values < 0.000 1). The titers of serum anti-rSjHsc20 antibody were all above 1∶16 384 in the rSjHsc20 immunization group following immunizations on days 1, 15 and 31, indicating that the rSjHsc20 protein had a strong immunogenicity. The mean worm burdens were (16.60±5.75), (15.80±5.58) worms per mouse and (14.40±5.75) worms per mouse in the PBS control group, the ISA 206 adjuvant group and the rSjHsc20 immunization group 42 days post-infection with S. japonicum cercariae (F = 0.50, P > 0.05), and the EPG were 68 370 ± 22 690, 67 972 ± 19 502, and 41 075 ± 13 251 in the PBS control group, the ISA 206 adjuvant group and the rSjHsc20 immunization group (F = 4.55, P < 0.05), with lower EPG in the PBS control group and the ISA 206 adjuvant group than in the rSjHsc20 immunization group (both P values < 0.05). Immunization with the rSjHsc20 protein resulted in a worm burden reduction of 13.25% and an egg burden reduction of 39.92% relative to the PBS control group. Conclusions SjHsc20 is successfully cloned and expressed, and the rSjHsc20 protein induces partial immunoprotective effects in mice, which provides a basis for deciphering the biological functions of SjHsc20 and assessing the potential of SjH-sc20 as a vaccine candidate.

Objective:To establish a radiotherapy treatment planning process of high ventilation functional lung avoided (HVFLA) for thoracic tumors based on 4D-CT lung ventilation functional images and determine the treatment planning strategy of HVFLA radiotherapy, and so as to provide support for the clinical trials of HVFLA radiotherapy in thoracic cancer patients.Methods:A deep learning-based 4D-CT lung ventilation functional imaging model was established and integrated into the radiotherapy treatment planning process. Furthermore, ten thoracic cancer patients with 4D-CT simulation positioning were retrospectively enrolled in this study. The established model was used to obtain the 4D-CT lung ventilation functional imaging for each patient. According to the relative value of lung ventilation, the lung ventilation areas are equally segmented into high, medium and low lung ventilation and then imported them into Pinnacle 3 treatment planning system. According to the prescription dose of target and dose constraints of organ at risks (OARs), the clinical and HVFLA treatment plans were designed for each patient using volumetric modulated radiotherapy technique, and each plan should meet the clinical requirements and adding dose constraints of high ventilation functional lung for HVFLA plan. The dosimetric indexes of the target, OARs (lungs, heart and cord) and high functional lung (HFL) were used to evaluated the plan quality. The dosimetric indexes included D2, D98 and mean dose of target, V5, V10, V20, V30 and mean dose of lungs and HFL, V30, V40 and mean dose of heart, and D1 cm 3 of cord. Paired samples t-test was used for statistical analysis of the two groups of plans. Results:The target and OARs of the clinical plan and HVFLA plan meet the clinical requirements. The HVFLA plan resulted in a statistically significant reduction in the mean dose, V5, V10, V20, and V30 of the high functional lung by 1.2 Gy, 5.9%, 4.2%, 2.6%, and 2.3%, respectively ( t=-8.07, 4.02, -6.02, -7.06, -6.77, P<0.05). There was no statistical difference in the dosimetric indexes of lungs, heart and cord. Conclusions:We established the treatment planning process of HVFLA radiotherapy based on 4D-CT lung ventilation functional images. The HVFLA plan can effectively reduce the dose of HFL, while the doses of lungs, heart and cord had no significant difference compared with the clinical plan. The strategy of HVFLA radiotherapy planning is feasible to provide support for the implementation of HVFLA radiotherapy in thoracic cancer patients.

Objective:To preliminarily evaluate the effects and analyze the influencing factors of continuous renal replacement therapy (CRRT) in severe burn patients complicated with acute kidney injury (AKI).Methods:This study was a retrospective case series study. From January 2010 to December 2020, 79 severe burn patients complicated with AKI who received CRRT and met the inclusion criteria were admitted to the First Affiliated Hospital of Army Medical University (the Third Military Medical University). The general data (the same below) of all patients were collected, including gender, age, body mass index, burn area, burn index, cause of injury, whether combined with inhalation injury, acute physiology and chronic health status evaluation Ⅱ (APACHE Ⅱ) score and sepsis-related organ failure assessment (SOFA) score on admission, admission time after burn, and time of AKI after admission. The total efficacy of CRRT, including overall effective rate, complete effective rate, partial effective rate, ineffective rate, and deterioration rate, creatinine, urea, cystatin C, and fluid overload rate before and after treatment, in-hospital mortality, predictive mortality based on Baux scoring model, the most common cause of death, and length of hospital stay were recorded. According to the effect of CRRT, the patients were divided into effective group (42 patients) and ineffective group (37 patients). The general information of patients, the time to initiate CRRT after the occurrence of AKI, the duration of CRRT, etiology of AKI, AKI stage before CRRT initiation, CRRT mode, anticoagulant type, and in-hospital mortality were compared between the two groups of patients. The independent influencing factors for CRRT in severe burn patients complicated with AKI were screened. According to the etiology of AKI, the patients were divided into prerenal group (22 patients) and renal group (57 patients). The general information of patients, the time to initiate CRRT after the occurrence of AKI, the duration of CRRT, and total efficacy of CRRT (except for the most common cause of death) were compared between the two groups of patients.Results:Among the 79 patients, 73 cases were male and 6 cases were female, with age of (46±14) years, body mass index of (24.0±2.9) kg/m 2, total burn area of (69±26)% total body surface area (TBSA), full-thickness burn area of (44±25)%TBSA, and burn index of 57 (36, 76). There were 36 cases of flame burns, 19 cases of electrical burns, 16 cases of hydrothermal burns, 6 cases of explosive burns, and 2 cases of chemical burns. Thirty-nine patients were complicated with inhalation injury. The APACHE Ⅱ score was 16 (12, 18) and the SOFA score was 11 (5, 13) on admission. The patients were admitted to the hospital on 0 (0, 2) d after burn, and AKI occurred on 0 (0, 6) d after admission. The overall effective rate of CRRT was 53.16% (42/79), the complete effective rate was 30.38% (24/79), the partial effective rate was 22.78% (18/79), the ineffective rate was 31.65% (25/79), and the deterioration rate was 15.19% (12/79). The creatinine and urea of patients after treatment were significantly lower than those before treatment (with Z values of -3.26 and -2.54, respectively, P<0.05); there were no statistically significant differences in the cystatin C and fluid overload rate of patients before and after treatment ( P>0.05). The in-hospital mortality of patients was 17.72% (14/79), and the predictive mortality based on Baux scoring model was 75.10% (18.94%, 91.84%). The most common cause of death was multiple organ failure, and the length of hospital stay was 39.43 (11.52, 110.58) d. There were statistically significant differences in the full-thickness burn area, the duration of CRRT, and etiology of AKI of patients between effective group and ineffective group (with Z values of -1.99 and -2.90, respectively, χ2=5.58, P<0.05). There were no statistically significant differences in the other indicators ( P>0.05). The etiology of AKI and full-thickness burn area were the independent influencing factors for CRRT in severe burn patients complicated with AKI (with odds ratios of 4.21 and 1.03, respectively, 95% confidence intervals of 1.20-14.80 and 1.00-1.05, respectively, P<0.05). There were statistically significant differences in the cause of injury, overall effective rate of CRRT, total burn area, burn index, admission time after burn, time of AKI after admission, the time to initiate CRRT after the occurrence of AKI, and predictive mortality based on Baux score model of patients between prerenal group and renal group (with χ2 values of 12.59 and 5.58, respectively, Z values of 2.46, 2.43, -2.43, -4.03, -3.01, and -2.31, respectively, P<0.05). Before treatment, urea and cystatin C of patients in renal group were significantly higher than those in prerenal group (with Z values of -2.98 and -2.77, respectively, P<0.05), and the liquid overload rate was significantly lower than that in prerenal group ( Z=-2.99, P<0.05); after treatment, the cystatin C of patients in renal group was significantly higher than that in prerenal group ( Z=-2.08, P<0.05); there were no statistically significant differences in the other indicators ( P>0.05). Conclusions:CRRT can significantly improve renal function, avoid fluid overload, and alleviate renal injury in severe burn patients complicated with AKI. Prerenal AKI is the main independent influencing factor leading to ineffective CRRT.

Objective:To investigate the relationship between the lowest hemoglobin value during hospitalization and the prognosis in patients with extensive burns, in order to explore the hemoglobin warning threshold for blood transfusion in patients with extensive burns.Methods:The research was a retrospective observational study. From October 2012 to October 2022, 288 patients with extensive burns who met the inclusion criteria were admitted to the First Affiliated Hospital of Army Medical University (the Third Military Medical University), including 243 males and 45 females, aged 18 to 65 years. These patients were assigned to the death group ( n=54) and the survival group ( n=234) based on their final prognosis. The clinical data including gender, age, body mass index, total burn area, full-thickness burn area, time of first operation after injury, preoperative prothrombin time (PT) and activated partial thromboplastin time (APTT) and hemoglobin level of the first surgery, complication of inhalation injury, number of surgeries, total surgical area, total surgical time, total length of hospital stay, and highest procalcitonin value, lowest platelet count and hemoglobin values, and occurrence of sepsis during hospitalization were compared between the two groups of patients. According to the lowest hemoglobin value during hospitalization, the patients were assigned to <65 g/L group, ≥65 g/L and <75 g/L group, ≥75 g/L and <85 g/L group, and ≥85 g/L group. The total length of hospital stay, mortality and incidence of sepsis during hospitalization, and mortality within 90 days after injury were compared among the four groups of patients. The relationship between the lowest hemoglobin value during hospitalization and the mortality risk of patients with extensive burns was analyzed using a restricted cubic spline model before and after adjusting covariates. A logistic regression model was adopted to analyze the relationship between the lowest hemoglobin value during hospitalization and the mortality risk of patients with extensive burns after adjusting covariates, with the lowest hemoglobin value during hospitalization as a continuous variable and a categorical variable, separately. Results:Compared with those in survival group, the total burn area, full-thickness burn area, and total surgical area of patients in death group were significantly increased, the preoperative APTT of the first surgery was significantly prolonged, the number of surgeries was significantly reduced, the total length of hospital stay was significantly shortened, the highest procalcitonin value during hospitalization was significantly increased, the lowest platelet count and hemoglobin values during hospitalization were significantly decreased, and the incidence proportion of sepsis during hospitalization was significantly increased (with Z values of -6.72, -5.40, -2.15, -2.99, -2.21, -7.84, -6.23, -7.03, and -3.43, respectively, χ2=161.95, P values all <0.05). There were no statistically significant differences in the other clinical data of patients between the two groups ( P>0.05). There were statistically significant differences in mortality and incidence of sepsis during hospitalization, and mortality within 90 days after injury of patients among the four groups divided according to the lowest hemoglobin value during hospitalization (with χ2 values of 12.12, 15.93, and 10.62, respectively, P<0.05). There was no statistically significant difference in the total length of hospital stay of patients among the four groups ( P>0.05). The restricted cubic spline model analysis revealed an approximately linear relationship between the lowest hemoglobin value during hospitalization and the mortality risk of patients with extensive burns before and after adjusting covariates (with χ2 values of 0.81 and 0.75, respectively, P>0.05). After adjusting covariates, the logistic regression model analysis showed that the mortality risk of patients with extensive burns increased with decreasing hemoglobin when the lowest hemoglobin value during hospitalization was analyzed as a continuous variable (with odds ratio of 0.96, with 95% confidence interval of 0.92 to 0.99, P<0.05). When using the median value of 75.5 g/L as the cut-off value for categorizing the lowest hemoglobin value during hospitalization, there was no statistically significant difference in the mortality risk between patients with hemoglobin <75.5 g/L and those with hemoglobin ≥75.5 g/L ( P>0.05). When the patients were divided into four groups based on the lowest hemoglobin value during hospitalization as above, using ≥85 g/L group as a reference, only patients in <65 g/L group had a significantly increased mortality risk (with odds ratio of 5.37, with 95% confidence interval of 1.57 to 18.29, P<0.05). Conclusions:There is an approximately linear correlation between the lowest hemoglobin value during hospitalization and the mortality risk of patients with extensive burns. When the hemoglobin level drops to 65 g/L or lower, the mortality risk of patients increases significantly, suggesting that a hemoglobin level of 65 g/L could serve as a warning threshold for blood transfusion in patients with extensive burns.