Blue light inactivation technology, particularly at the 405 nm wavelength, has demonstrated distinct and multifaceted mechanisms of action against both Gram-positive and Gram-negative bacteria, offering a promising alternative to conventional antibiotic therapies. For Gram-positive pathogens such as Bacillus cereus, Listeria monocytogenes, and methicillin-resistant Staphylococcus aureus (MRSA), the bactericidal effects are primarily mediated by endogenous porphyrins (e.g., protoporphyrin III, coproporphyrin III, and uroporphyrin III), which exhibit strong absorption peaks between 400-430 nm. Upon irradiation, these porphyrins are photoexcited to generate cytotoxic reactive oxygen species (ROS), including singlet oxygen, hydroxyl radicals, and superoxide anions, which collectively induce oxidative damage to cellular components. Early studies by Endarko et al. revealed that (405±5) nm blue light at 185 J/cm² effectively inactivated L. monocytogenes without exogenous photosensitizers, supporting the hypothesis of intrinsic photosensitizer involvement. Subsequent work by Masson-Meyers et al. demonstrated that 405 nm light at 121 J/cm² suppressed MRSA growth by activating endogenous porphyrins, leading to ROS accumulation. Kim et al. further elucidated that ROS generated under 405 nm irradiation directly interact with unsaturated fatty acids in bacterial membranes, initiating lipid peroxidation. This process disrupts membrane fluidity, compromises structural integrity, and impairs membrane-bound proteins, ultimately causing cell death. In contrast, Gram-negative bacteria such as Salmonella, Escherichia coli, Helicobacter pylori, Pseudomonas aeruginosa, and Acinetobacter baumannii exhibit more complex inactivation pathways. While endogenous porphyrins remain central to ROS generation, studies reveal additional photodynamic contributors, including flavins (e.g., riboflavin) and bacterial pigments. For instance, H. pylori naturally accumulates protoporphyrin and coproporphyrin mixtures, enabling efficient 405 nm light-mediated inactivation without antibiotic resistance concerns. Kim et al. demonstrated that 405 nm light at 288 J/cm² inactivates Salmonella by inducing genomic DNA oxidation (e.g., 8-hydroxy-deoxyguanosine formation) and disrupting membrane functions, particularly efflux pumps and glucose uptake systems. Huang et al. highlighted the enhanced efficacy of pulsed 405 nm light over continuous irradiation for E. coli, attributing this to increased membrane damage and optimized ROS generation through frequency-dependent photodynamic effects. Environmental factors such as temperature, pH, and osmotic stress further modulate susceptibility, sublethal stress conditions (e.g., high salinity or acidic environments) weaken bacterial membranes, rendering cells more vulnerable to subsequent ROS-mediated damage. The 405 nm blue light inactivates drug-resistant Pseudomonas aeruginosa through endogenous porphyrins, pyocyanin, and pyoverdine, with the inactivation efficacy influenced by bacterial growth phase and culture medium composition. Intriguingly, repeated 405 nm exposure (20 cycles) failed to induce resistance in A. baumannii, with transient tolerance linked to transient overexpression of antioxidant enzymes (e.g., superoxide dismutase) or stress-response genes (e.g., oxyR). For Gram-positive bacteria, porphyrin abundance dictates sensitivity, whereas in Gram-negative species, membrane architecture and accessory pigments modulate outcomes. Critically, ROS-mediated damage is nonspecific, targeting DNA, proteins, and lipids simultaneously, thereby minimizing resistance evolution. The 405 nm blue light technology, as a non-chemical sterilization method, shows promise in medical and food industries. It enhances infection control through photodynamic therapy and disinfection, synergizing with red light for anti-inflammatory treatments (e.g., acne). In food processing, it effectively inactivates pathogens (e.g., E. coli, S. aureus) without altering food quality. Despite efficacy against multidrug-resistant A. baumannii, challenges include device standardization, limited penetration in complex materials, and optimization of photosensitizers/light parameters. Interdisciplinary research is needed to address these limitations and scale applications in healthcare, food safety, and environmental decontamination.

Post-endoscopic retrograde cholangiopancreatography pancreatitis(PEP)is one of the most common complications after endoscopic retrograde cholangiopancreatography(ERCP).Numerous PEP prediction models have been established based on different statistical methods at home and abroad.The PEP prediction model,as a tool for evaluating and screening high-risk populations,can provide a basis for medical staff to find high-risk PEP patients early and take effective preventive measures.In recent years,new PEP prediction models have appeared one after another,but there is still a lack of recognized reliable prediction models in clinic.This article reviews the research status of PEP risk prediction models,aim to provide a direction for establishing a more reliable,accurate,and practical PEP risk prediction model in the later period.

HDAC(histone deacetylase)is a class of epigenetic modifying enzymes that can deacetylate proteins by altering the acetylation status of histones in the nucleus,regulating promoter activation levels,and thereby affecting downstream gene expression.However,expression changes of HDACs during endo-thelial differentiation are still unclear.This study used a three-stage method to induce human induced pluripotent stem cells(hiPSCs)to differentiate into endothelial cells,and qRT-PCR was used to detect the expression changes of class I HDAC(HDAC1,2)and class Ⅱ HDAC(HDAC4,5)genes.It was found that HDAC5 exhibits significant expression changes during endothelial differentiation.It is downreg-ulated by 90％during the mesodermal differentiation stage(P＜0.01),upregulated by 3.7-fold during the vascular precursor stage(P＜0.01),and subsequently downregulated by 70％during the late stage of endothelial differentiation(P＜0.01).Immunoblotting experiments further confirmed that HDAC5 under-goes periodic expression changes during endothelial differentiation.Mechanistic studies have shown that HDAC5 downregulation during the differentiation stage of the mesoderm is mediated by Wnt signaling.CHIR99021 treatment and overexpression of Wnt3a can activate the Wnt signaling pathway,leading to HDAC5 downregulation.Inhibiting the Wnt signaling pathway through IWP-2 promotes the recovery of HDAC5 expression.In addition,it was found that HDAC5 is mainly localized in the nucleus,and IWP-2 restores HDAC5 expression,but it remains in the cytoplasm.Further research suggests that downregu-lation of HDAC5 during mesodermal differentiation may contribute to the expression of the mesodermal marker BraT.Treatment with the HDAC inhibitor BML210 can promote early mesodermal differentiation,interfere with endothelial differentiation of vascular precursor cells,and enhance late-stage endothelial differentiation.In conclusion,HDAC5 displays a stage-specific expression during endothelial differentia-tion,and Wnt signaling activation is the main mechanism regulating the downregulation of HDAC5 during the mesoderm stage.

Objective:To investigate the effect of genetic polymorphism of MTHFR C677T (rs1801133) on methotrexate (MTX) related toxicity in pediatric mature B-cell lymphoma patients. Methods:Fifty-eight intermediate and high risk patients under 18 years of age with mature B-cell lymphoma who received 5 g/m2 MTX (24 h intravenous infusion) in Sun Yat-sen University Cancer Center from August 2014 to December 2021 were included,and their toxicity of high-dose MTX (HD-MTX) were monitored and analyzed. Results:Among the 58 pediatric patients,the number of CC,CT,and TT genotypes for MTHFR C677T was 33,19 and 6,respectively. A total of 101 courses of HD-MTX therapy were counted,of which plasma MTX level>0.2 μmol/L at 48 h post-MTX infusion were observed in 35 courses,≤0.2 μmol/L in 66 courses. Inter-group comparison showed that plasma MTX level>0.2 μmol/L at 48 h post-MTX infusion increased the risk of developing oral mucositis (P<0.05). Compared with wild-type (CC genotype),patients in the mutant group (CT+TT genotype) were more likely to develop myelosuppression,manifested as anemia,leucopenia,neutropenia and thrombocytopenia. However,plasma MTX level at 48 h was not associated with MTHFR C677T gene polymorphism. Conclusion:The risk of developing oral mucositis in children with mature B-cell lymphoma is associated with plasma MTX concentration. Polymorphism of MTHFR C677T gene is not related to plasma MTX concentration in children with mature B-cell lymphoma,but is related to grade Ⅲ to Ⅳ hematological toxicity.

AIM To optimize the extraction process for uracil,hypoxanthine,xanthine,uridine,thymine,inosine,guanosine and 2'-deoxyguanosine from Pheretima guillelmi(Michaelsen),and to determine their contents.METHODS With solid-liquid ratio,ultrasonic time and ultrasonic temperature as influencing factors,contents of hypoxanthine and total nucleosides as evaluation indices,the extraction process was optimized by orthogonal test.HPLC was adopted in the content determination of varioud nucleosides,the analysis was performed on a 30℃thermostatic Agilent C18 column(4.6 mm×250 mm,5 μm),with the mobile phase comprising of methanol-water flowing at 1 mL/min in a gradient elution manner,and the detection wavelength was set at 260 nm.RESULTS The optimal conditions were determined to be 1∶250 for solid-liquid ratio,60 min for ultrasonic time,and 60℃for ultrasonic temperature.Eight nucleosides showed good linear relationships within their own ranges(R2＞0.999 0),whose average recoveries were 99.11%-103.27%with the RSDs of 0.85%-2.89%.CONCLUSION This stable and reliable method can be used for the extraction and content determination of nucleosides from P.guillelmi.

China prospective multicenter birth cohort (Prospective Omics Health Atlas birth cohort, POHA birth cohort) study was officially launched in 2022. This study, in collaboration with 12 participating units, aims to establish a high-quality, multidimensional cohort comprising 20 000 naturally conceived families and assisted reproductive families. The study involves long-term follow-up of parents and offspring, with corresponding biological samples collected at key time points. Through multi-omics testing and analysis, the study aims to conduct multi-omics big data research across the entire maternal and infant life cycle. The goal is to identify new biomarkers for maternal and infant diseases and provide scientific evidence for risk prediction related to maternal diseases and neonatal health.

Objective:To investigate the early clinical characteristics of elderly patients with severe burns and the risk factors on prognosis.Methods:This study was a retrospective case series study. Clinical data of 124 elderly patients with severe burns who met the inclusion criteria and were admitted to the 12 hospitals from January 2015 to December 2020 were collected, including 4 patients from the Fourth People's Hospital of Dalian, 5 patients from Fujian Medical University Union Hospital, 22 patients from Guangzhou Red Cross Hospital of Jinan University, 5 patients from Heilongjiang Provincial Hospital, 27 patients from the First Affiliated Hospital of Naval Medical University, 9 patients from the First Affiliated Hospital of Nanchang University, 10 patients from Affiliated Hospital of Nantong University, 9 patients from Tongren Hospital of Wuhan University & Wuhan Third Hospital, 12 patients from the 924 th Hospital of PLA, 6 patients from Zhangjiagang First People's Hospital, 4 patients from Taizhou Hospital of Zhejiang Province, and 11 patients from Zhengzhou First People's Hospital. The patients' overall clinical characteristics, such as gender, age, body mass index, total burn area, full-thickness burn area, inhalation injury, causative factors, whether combined with underlying medical diseases, and admission time after injury were recorded. According to the survival outcome within 28 days after injury, the patients were divided into survival group (89 cases) and death group (35 cases). The following data of patients were compared between the two groups, including the basic data and injuries (the same as the overall clinical characteristics ahead); the coagulation indexes within the first 24 hours of injury such as prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time, D-dimer, fibrinogen degradation product (FDP), international normalized ratio (INR), and fibrinogen; the blood routine indexes within the first 24 hours of injury such as white blood cell count, platelet count, neutrophil-to-lymphocyte ratio, monocyte count, red blood cell count, hemoglobin, and hematocrit; the organ function indexes within the first 24 hours of injury such as direct bilirubin, total bilirubin, urea, serum creatinine, aspartate aminotransferase, alanine aminotransferase, total protein, albumin, globulin, blood glucose, triglyceride, total cholesterol, alkaline phosphatase, creatine kinase, electrolyte indexes (potassium, sodium, chlorine, calcium, magnesium, and phosphorus in blood), uric acid, myoglobin, and brain natriuretic peptide; the infection and blood gas indexes within the first 24 hours of injury such as procalcitonin, C-reactive protein, pH value, oxygenation index, base excess, and lactate; treatment such as whether conducted with mechanical ventilation, whether conducted with continuous renal replacement therapy, whether conducted with anticoagulation therapy, whether applied with vasoactive drugs, and fluid resuscitation. The analysis was conducted to screen the independent risk factors for the mortality within 28 days after injury in elderly patients with severe burns. Results:Among 124 patients, there were 82 males and 42 females, aged 60-97 years, with body mass index of 23.44 (21.09, 25.95) kg/m 2, total burn area of 54.00% (42.00%, 75.00%) total body surface area (TBSA), and full-thickness burn area of 25.00% (10.00%, 40.00%) TBSA. The patients were mainly combined with moderate to severe inhalation injury and caused by flame burns. There were 43 cases with underlying medical diseases. The majority of patients were admitted to the hospital within 8 hours after injury. There were statistically significant differences between patients in the 2 groups in terms of age, total burn area, full-thickness burn area, and inhalation injury, and PT, APTT, D-dimer, FDP, INR, white blood cell count, platelet count, urea, serum creatinine, blood glucose, blood sodium, uric acid, myoglobin, and urine volume within the first 24 hours of injury (with Z values of 2.37, 5.49, 5.26, 5.97, 2.18, 1.95, 2.68, 2.68, 2.51, 2.82, 2.14, 3.40, 5.31, 3.41, 2.35, 3.81, 2.16, and -3.82, respectively, P<0.05); there were statistically significant differences between two groups of patients in whether conducted with mechanical ventilation and whether applied with vasoactive drugs (with χ2 values of 9.44 and 28.50, respectively, P<0.05). Age, total burn area, full-thickness burn area, serum creatinine within the first 24 hours of injury, and APTT within the first 24 hours of injury were the independent risk factors for the mortality within 28 days after injury in elderly patients with severe burns (with odds ratios of 1.17, 1.10, 1.10, 1.09, and 1.27, 95% confidence intervals of 1.03-1.40, 1.04-1.21, 1.05-1.19, 1.05-1.17, and 1.07-1.69, respectively, P<0.05). Conclusions:The elderly patients with severe burns had the injuries mainly from flame burns, often accompanied by moderate to severe inhalation injury and enhanced inflammatory response, elevated blood glucose levels, activated fibrinolysis, and impaired organ function in the early stage, which are associated with their prognosis. Age, total burn area, full-thickness burn area, and serum creatinine and APTT within the first 24 hours of injury are the independent risk factors for death within 28 days after injury in this population.

Attention deficit hyperactivity disorder(ADHD)is a common neurodevelopmental disorder in children and adolescents,and its etiology and pathogenesis are still unclear.Brain is the organ with the largest oxygen consumption in human body and is easily affected by oxidative imbalance.Oxidative stress has become the key research direction for the pathogenesis of ADHD,but there is still a lack of relevant studies in China.Based on the latest research findings in China and overseas,this article reviews the clinical and experimental studies on oxidative stress in ADHD and explores the association of oxidative stress with neurotransmitter imbalance,neuroinflammation,and cell apoptosis in the pathogenesis of ADHD,so as to provide new research ideas for exploring the pathogenesis of ADHD.[Chinese Journal of Contemporary Pediatrics,2024,26(2):201-206]

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

Aim To investigate the effect of quercetin on the aging model of bone marrow mesenchymal stem cells established under microgravity. Methods Using 3D gyroscope, a aging model of bone marrow mesenchymal stem cells was constructed, and after receiving quercetin and microgravity treatment, the anti-aging effect of the quercetin was evaluated by detecting related proteins and oxidation indexes. Results Compared to the control group, the expressions of age-related proteins p21, pi6, p53 and RB in the microgravity group significantly increased, while the expressions of cyclin D1 and lamin B1 significantly decreased, with statistical significance (P<0.05). In the microgravity group, mitochondrial membrane potential significantly decreased (P<0.05), ROS accumulation significantly increased (P <0.05), SOD content significantly decreased and MDA content significantly increased (P<0.05). Compared to the microgravity group, the expressions of age-related proteins p21, pi6, p53 and RB in the quercetin group significantly decreased, while the expressions of cyclin D1 and lamin B1 significantly increased, with statistical significance (P<0.05). In the quercetin group, mitochondrial membrane potential significantly increased (P<0.05), ROS accumulation significantly decreased (P<0.05), SOD content significantly increased and MDA content significantly decreased (P<0.05). Conclusions Quercetin can resist oxidation, protect mitochondrial function and normal cell cycle, thus delaying the aging of bone marrow mesenchymal stem cells induced by microgravity.