This study aimed to explore the interaction between the small molecule Lyb24 and PyrD, a key enzyme in the pyrimidine biosynthesis pathway of Klebsiella pneumoniae (KP), and the effect of Lyb24 on the catalytic activity of PyrD, thus to provide a theoretical basis for the development of novel antimicrobial agents. The pET-30a(+)-PyrD recombinant plasmid was constructed using Nde I/Xba I double digestion technology and was transformed into Escherichia coli BL21 (DE3) competent cells using the heat-shock method. The recombinant protein was induced at 16 ℃ with 0.3 mmol/L isopropyl β-D-thiogalactopyranoside (IPTG). The recombinant PyrD protein was purified using nickel-nitrilotriacetic acid (Ni-NTA) affinity chromatography to obtain a high-purity product. Surface plasmon resonance (SPR) experiments were conducted to detect the direct interaction between Lyb24 and PyrD protein, and a DCIP-based colorimetric assay was used to evaluate the effect of Lyb24 on the catalytic activity of PyrD. The pET-30a(+)-PyrD plasmid was successfully constructed, and the recombinant PyrD protein with a molecular weight of approximately 36 kD was expressed and purified to a concentration of 5.58 mg/mL. Lyb24 exhibited high-affinity direct binding to PyrD (KD = 8.83 × 10−5 mol/L) and exerted an uncompetitive inhibition effect on the catalytic activity of PyrD. This study demonstrates that Lyb24, a small-molecule compound, directly binds to PyrD and inhibits its enzymatic activity, providing crucial experimental evidence for developing PyrD-targeted antibacterial agents with value of clinical translation.

Background Prenatal exposure to fine particulate matter (PM_2.5) is closely associated with cortical damage and neuroinflammation in offspring. The cyclic guanosine monophosphate–adenosine monophosphate synthase (cGAS)–stimulator of interferon genes (STING) signaling pathway is a key regulator of inflammation and may be subject to epigenetic regulation. Objective To investigate the role of cGAS-STING pathway activation in PM_2.5-induced cortical damage in offspring mice during pregnancy and the underlying epigenetic regulatory mechanisms. Methods Open field tests were used to assess depressive-like behavior in offspring mice. Morphological analysis was conducted to evaluate cortical damage and microglial activation in offspring brains. Real-time fluorescent quantitative PCR (RT-qPCR) and Western blot (WB) were performed to detect changes in the expression of key molecules in the cGAS-STING pathway in cortical tissue. A PM_2.5-induced microglial cell injury model was established in BV2 cells. Microglial activation was observed, cell viability was measured using the Cell Counting Kit-8 (CCK-8), and the expression levels of inducible nitric oxide synthase (iNOS) and key molecules in the cGAS-STING pathway were detected by RT-qPCR and WB. Bioinformatics analysis was performed to explore the epigenetic regulatory association between the STING signaling pathway and lysine-specific demethylase 5A (KDM5A). Changes in KDM5A mRNA and protein expression, as well as the protein level of histone H3 lysine 4 trimethylation (H3K4me3), were detected in an in vitro PM_2.5 injury model. Using small interfering RNA (siRNA) technology, the KDM5A gene was silenced in BV2 cells exposed to PM_2.5. The protein expression of H3K4me3 was detected to evaluate improvements in microglial activation, changes in inflammatory markers such as iNOS and mannose receptor (CD206), and alterations in the cGAS-STING pathway. Results Compared with the control group, the total distance of offspring mice in the PM_2.5 group was significantly reduced, and both the distance traveled and the time spent in the central area of the open field were significantly decreased (P<0.01, P<0.001), indicating depressive-like behavior in the offspring mice. Compared with the control group, the offspring mice in the PM_2.5 group exhibited disorganized cortical structure and significantly activated microglia (P<0.01), with significantly increased mRNA and protein levels of cGAS and STING (P<0.05, P<0.01, or P<0.001). The in vitro experiments demonstrated that the PM_2.5 treatment induced BV2 cells to polarize toward the M1 phenotype, exhibiting a distinct amoeboid morphology, with upregulated expression of the pro-inflammatory factor iNOS (P<0.05, P<0.01, or P<0.001) and activation of the cGAS-STING pathway (P<0.05, P<0.01). The analysis of RNA-seq data from KDM5A knockout cells revealed significantly downregulated STING expression, suggesting that KDM5A may activate the STING signaling pathway. The in vitro experiments further confirmed that the PM_2.5-treated BV2 cells exhibited significantly elevated mRNA and protein levels of KDM5A (P<0.01), while the H3K4me3 protein levels were markedly reduced (P<0.05). After silencing KDM5A in BV2 cells exposed to PM_2.5, compared with the PM_2.5+siNC group, the PM_2.5+siKDM5A group showed no obvious microglial activation and polarized toward the M2 phenotype, with significantly decreased expression levels of iNOS, cluster of differentiation 16 (CD16), and interleukin-1β (P<0.05, P<0.01), and significantly increased expression levels of anti-inflammatory factors CD206, YM1, and interleukin-10 (P<0.01, P<0.001). Meanwhile, the expression levels of cGAS and STING were also reduced (P<0.05, P<0.01). Conclusion KDM5A activates microglia through the cGAS-STING pathway, thereby contributing to PM_2.5-induced cortical damage in offspring mice during pregnancy.

Objective:To evaluate the efficacy of digitally assisted design of surgical template for fibular composite tissue flap in reconstruction of segmental mandibular defect with soft tissue defect.Methods:A retrospective analysis was conducted on 30 patients who were treated at the Department of Otolaryngology Head and Neck Surgery, the 920th Hospital of the Joint Logistics Support Force of Chinese PLA from July 2020 to May 2024 for segmental mandibular defects combined with soft tissue defect. The cohort comprised 19 males and 11 females and aged 11-71 years (44.33 years±15.31 years). Pathological diagnoses of the patients were ameloblastoma (14 cases), squamous cell carcinoma (9 cases), osteomyelitis (4 cases), and odontogenic keratocyst (3 cases). Primary reconstructive surgery were performed on 21 patients after surgical resection of lesions, and 9 patients received secondary reconstructive surgery. The length of mandibular defect ranged from 75.83 mm to 111.45 mm (87.31 mm±12.00 mm), and soft tissue defects were measured at 5.0 cm×1.8 cm to 8.6 cm×2.1 cm (mean area 13.63 cm 2±2.42 cm 2). Preoperative CTA was performed to locate the perforator of peroneal artery and for design of digital surgical template. Intraoperatively, a modified fibula composite tissue flap harvesting technique was employed and that involved in: CTA-guided perforator planning, fibula osteotomy, anterior intermuscular septum exposure for identifying the peroneal artery, and a digital template-assisted fibula crafting for reconstruction of mandibule and soft tissue defect. Postoperative follow-ups were conducted at 1, 3, and 6 months, followed by quarterly reviews at outpatient clinic or via telephone interviews. Statistical analysis was performed using SPSS 27.0 software with descriptive statistical methods. Results:After surgery, all the fibula composite tissue flaps were viable and the incision wound healed well. Two patients had partial necroses at distal edge of the flaps, and they were healed after treatment. One patient had donor site infection and healed after anti-infective treatment. One month after the surgery, patients were assessed according to the recovery of face, mouth opening and occlusion, of which 25 patients (83.3%) were rated of Grade I, 4 (13.3%) of Grade Ⅱ, and 1 (3.4%) of Grade Ⅳ, with an excellent and good rates of 96.6%. The average distance of condylar movement on the affected side was 1.28 mm±0.35 mm. Postoperative follow-up lasted for 10 to 22 months, with 19.17 months±2.14 months in average. Assessment at the final follow-up was found that a total of 26 patients (86.8%) were of Grade I, 3 (10.0%) of Grade Ⅱ, and 1 (3.3%) of Grade Ⅳ and all the transferred fibula showed good alignment with the mandible over the postoperative follow-up period.Conclusion:Digital template-assisted design of fibular composite tissue flap enables a precise vascular protection, individualised osteotomy and functional restoration in reconstruction of segmental mandibular defect with soft tissue defect. It demonstrates a high clinical feasibility.

Objective:To investigate the association between serum 25-hydroxyvitamin D [25(OH)D] levels and 24-h urinary calcium excretion (24-h UCaE) and hypercalciuria in Chinese adults.Methods:This cross-sectional study was conducted from March 2022 to March 2023 in nine cities in China and included 1 239 residents. Demographic characteristics were collected through questionnaires and physical examinations, fasting blood samples were assessed for bone metabolism indicators, and 24-h urine samples were used to determine the 24-h UCaE. Multiple linear regression analysis was used to explore the relationship between serum 25(OH)D and 24-h UCaE and bone metabolism indexes. The relationship between serum 25(OH)D and hypercalciuria was analyzed using a multiple logistic regression model combined with restricted cubic spline modeling.Results:The mean participant age was (47.9±18.1) years, of which 453 (36.6%) were male. The percentages of vitamin D sufficiency, insufficiency, and deficiency were 7.6% (94/1 239), 29.0% (359/1 239), and 63.4% (786/1 239), respectively. The multiple linear regression model showed that after adjusting for the covariates the 24-h UCaE gradually increased with higher levels of 25(OH)D ( P overall <0.001, P nonlinear <0.001). The logistic regression analysis revealed that compared with the vitamin D deficient group, the OR for the prevalence of hypercalciuria in the vitamin D sufficient and vitamin D insufficient groups were 3.290 (95% CI 1.745 to 6.202) and 3.742 (95% CI 2.458 to 5.697), respectively. The results of the restricted cubic spline modeling showed a positive nonlinear relationship between 25(OH)D and the prevalence of hypercalciuria ( P overall <0.001, P nonlinear <0.001). The prevalence of hypercalciuria increased when 25(OH)D was >17.00 μg/L and peaked at 26.71 μg/L, after which there was a decreasing trend in the prevalence of hypercalciuria with increasing 25(OH)D. Conclusion:Associations between serum 25(OH)D levels and urinary calcium excretion and the prevalence of hypercalciuria were observed in the Chinese adult population.

Objective:To develop and validate a clinical warning model for severe pediatric community-acquired pneumonia (CAP) using electronic health records.Methods:A retrospective cohort study was conducted, analyzing clinical data of 15 750 children hospitalized for CAP at Wuhan Children′s Hospital between January 1, 2019, and December 31, 2023. Patient data were randomly split into training and testing sets at a 7∶3 ratio. Six supervised machine learning models were constructed in the training set, optimized using five-fold cross-validation, and evaluated in the testing set. Model performance was assessed using ROC-AUC, sensitivity, specificity, positive predictive value, negative predictive value, calibration curves, and clinical decision curve analysis at optimal thresholds. The best-performing model was selected, and SHapley Additive exPlanations (SHAP) were used to interpret feature importance. A program interface was developed based on the model results, enabling integration into clinical decision support systems for automated early warning.Results:A total of 15 750 participants, ranging in age from 28 days to 18 years, were included in the study. The median age was 2 years [interquartile range (IQR): 0-4 years], with 9 555 males (60.67%) and 6 195 females (39.33%). Among them, 2 211 (14.04%) developed severe pneumonia. In the prediction models, XGB outperformed other models with an ROC-AUC of 0.884 (95% CI: 0.870-0.898), sensitivity (0.803, 95% CI: 0.772-0.832), specificity (0.828, 95% CI: 0.816-0.839). Calibration analysis showed strong agreement between predicted and observed risks (Brier score: 0.081, 95% CI: 0.075-0.086). The analysis based on the SHAP method revealed that respiratory rate, heart rate, T-lymphocyte subsets, and red blood cell volume distribution width-SD are predictive factors for severe progression of community-acquired pneumonia (CAP) in children. Conclusion:An interpretable machine learning model was developed for the early detection and personalized treatment planning of severe CAP in children, providing valuable support to clinicians.

Objective To explore the efficacy of DSA-guided intrathecal drug delivery system combined with Zi Wu Liu Zhu Acupoint Therapy for management of cancer pain and provide reference for its standardized clinical application.Methods and Results Recommendations were formulated based on literature review and expert group discussion,and consensus was reached following expert consultation.The consensus recommendations are comprehensive,covering the entire treatment procedures from preoperative assessment and preparation,surgical operation process,postoperative management and traditional Chinese medicine treatment to individualized treatment planning.The study results showed that the treatment plans combining traditional Chinese with Western medicine effectively alleviated cancer pain,reduced the use of opioid drugs,and significantly improved the quality of life and enhanced immune function of the patients.Postoperative follow-up suggested good treatment tolerance among the patients without serious complications.Conclusion The formulated consensus is comprehensive and can provide reference for clinicians to use DSA-guided intrathecal drug delivery system combined with Zi Wu Liu Zhu Acupoint Therapy.The combined treatment has a high clinical value with a good safety profile for management of cancer pain.

Silent mutations within the RAS  gene have garnered increasing attention for their potential roles in tumorigenesis and therapeutic strategies. Kirsten-RAS ( KRAS ) mutations, predominantly oncogenic, are pivotal drivers in various cancers. While extensive research has elucidated the molecular mechanisms and biological consequences of active KRAS  mutations, the functional significance of silent mutations remains relatively understudied. This review synthesizes current knowledge on KRAS  silent mutations, highlighting their impact on cancer development. Silent mutations, which do not alter protein sequences but can affect RNA stability and translational efficiency, pose intriguing questions regarding their contribution to tumor biology. Understanding these mutations is crucial for comprehensively unraveling KRAS -driven oncogenesis and exploring novel therapeutic avenues. Moreover, investigations into the clinical implications of silent mutations in KRAS -mutant tumors suggest potential diagnostic and therapeutic strategies. Despite being in early stages, research on KRAS  silent mutations holds promise for uncovering novel insights that could inform personalized cancer treatments. In conclusion, this review underscores the evolving landscape of KRAS  silent mutations, advocating for further exploration to bridge fundamental biology with clinical applications in oncology.
Humans ; Mutation/genetics* ; Neoplasms/genetics* ; Proto-Oncogene Proteins p21(ras)/genetics* ; Animals

BACKGROUND: Pre-transplant exposure to immune checkpoint inhibitors (ICIs) significantly increases the risk of allograft rejection after liver transplantation (LT); however, whether ICI-related rejection leads to increased graft loss remains controversial. Therefore, this study aimed to investigate the association between ICI-related allograft rejection and perioperative graft loss. METHODS: This was a retrospective analysis of adult liver transplant recipients with early biopsy-proven T-cell-mediated rejection (TCMR) at Liver Transplantation Center of Sun Yat-sen Memorial Hospital from June 2019 to September 2024. The pathological features, clinical characteristics, and perioperative graft survival were analyzed. RESULTS: Twenty-eight patients who underwent early TCMR between June 2019 and September 2024 were included. Based on pre-LT ICI exposure, recipients were categorized into ICI-related TCMR (irTCMR, n = 12) and conventional TCMR (cTCMR, n = 16) groups. Recipients with irTCMR had a higher median Banff rejection activity index (RAI) (6 vs . 5, P = 0.012) and more aggressive tissue damage and inflammation. Recipients with irTCMR showed higher proportion of treatment resistance, achieving a complete resolution rate of only 8/12 compared to 16/16 for cTCMR. Graft loss occurred in 5/12 of irTCMR recipients within 90 days after LT, with no graft loss in cTCMRs recipients. Cox analysis demonstrated that irTCMR with an ICI washout period of <30 days was an independent risk factor for perioperative graft loss (hazard ratio [HR], 6.540; 95% confidence interval [CI], 1.067-40.067, P = 0.042). CONCLUSION IrTCMR is associated with severe pathological features, increased resistance to treatment, and higher graft loss in adult liver transplant recipients.
Humans ; Liver Transplantation/adverse effects* ; Male ; Female ; Middle Aged ; Retrospective Studies ; Graft Rejection/immunology* ; Immune Checkpoint Inhibitors/therapeutic use* ; Adult ; T-Lymphocytes/drug effects* ; Graft Survival/immunology* ; Aged

BACKGROUND: The potential impact of pre-existing coronary artery stenosis (CAS) on right ventricular (RV) function during acute pulmonary embolism (PE) episodes remains underexplored. This study aimed to investigate the association between pre-existing CAS and RV dysfunction in patients with acute PE. METHODS: In this multicenter, case-control study, 89 cases and 176 controls matched for age were enrolled at three study centers (Peking Union Medical College Hospital, Fuwai Hospital, and the Second Affiliated Hospital of Harbin Medical University) from January 2016 to December 2020. The cases were patients with acute PE with CAS, and the controls were patients with acute PE without CAS. Coronary artery assessment was performed using coronary computed tomographic angiography. CAS was defined as ≥50% stenosis of the lumen diameter in any coronary vessel >2.0 mm in diameter. Conditional logistic regression analysis was used to evaluate the association between CAS and RV dysfunction. RESULTS: The percentages of RV dysfunction (19.1% [17/89] vs. 44.6% [78/176], P <0.001) and elevated systolic pulmonary artery pressure (sPAP) (19.3% [17/89] vs. 39.5% [68/176], P = 0.001) were significantly lower in the case group than those in the control group. In the multivariable logistic regression model, CAS was independently and negatively associated with RV dysfunction (adjusted odds ratio [OR]: 0.367; 95% confidence interval [CI]: 0.185-0.728; P = 0.004), and elevated sPAP (OR: 0.490; 95% CI: 0.252-0.980; P = 0.035), respectively. CONCLUSIONS Pre-existing CAS was significantly and negatively associated with RV dysfunction and elevated sPAP in patients with acute PE. This finding provides new insights into RV dysfunction in patients with acute PE with pre-existing CAS.
Humans ; Pulmonary Embolism/complications* ; Case-Control Studies ; Male ; Ventricular Dysfunction, Right/physiopathology* ; Female ; Middle Aged ; Aged ; Coronary Stenosis/complications* ; Logistic Models ; Adult

With the rapid development of competitive sports, the incidence of anterior cruciate ligament (ACL) injury is on the rise. Such injuries may shorten athletes′ career and lead to other long-term adverse consequences. Although athletes generally recover well after ACL reconstruction, many still struggle to return to their pre-injury performance levels. Advances in the understanding of ACL anatomy and injury mechanisms, along with the evolution of surgical techniques and rehabilitation methods, have provided more individualized and tailored options for athletes following ACL injuries. However, there is currently no consensus in China regarding surgical and rehabilitation strategies for competitive athletes aiming to return to sports after ACL injuries. To this end, the Sports Medicine Committee of the Chinese Research Hospital Association and the Editorial Board of the Chinese Journal of Trauma jointly formulated the Expert consensus on surgical treatment and rehabilitation for competitive sports athletes returning to sports after anterior cruciate ligament injury ( version 2025), and presented 14 recommendations covering surgical indications, preoperative rehabilitation, surgical timing, surgical strategies and postoperative rehabilitation strategies, aiming to improve the surgical treatment and rehabilitation system for ACL injuries in competitive athletes and facilitate their return to high-level sports performance after injury.