OBJECTIVE To investigate the mechanism by which Naozhenning granules （NZN） improve learning and memory impairment in a rat model of multiple cerebral concussion （MCC）. METHODS The MCC rat model was established using the closed controlled cortical impact method. The experiment was set up with a blank group （normal saline）， a model group （normal saline）， a piracetam group （positive control group， 0.324 g/kg）， and high-， medium-， and low-dose NZN groups （5.4， 2.7， 1.35 g/kg）， with 11 rats in each group. Drugs or normal saline were administered by gavage once daily for 28 consecutive days. General condition and body weight were monitored throughout the experiment. The sucrose preference rate and novel object recognition index were measured； Evans blue （EB） extravasation in the cerebral cortex was detected； pathological changes of cortical neurons were observed； the levels of B-cell lymphoma-2 （Bcl-2）， Bcl-2-associated X protein （Bax）， interleukin-6 （IL-6）， IL-10， and tumor necrosis factor-α （TNF-α） in the cerebral cortex were determined； and the phosphorylation levels of AMP-activated protein kinase （AMPK）， glycogen synthase kinase 3β （GSK3β）， and Tau protein were detected. RESULTS Compared with the blank group， the model group showed poor mental state， sluggish response to external stimuli， reduced food and water intake， decreased limb flexibility， and disheveled fur. Body weight， sucrose preference rate， and novel object recognition index were significantly decreased （ P ＜0.05）； EB extravasation in the cerebral cortex was significantly increased （ P ＜0.05）， with severe neuronal damage. The positive area ratio of Bax protein， IL-6 and TNF-α levels， and Tau protein phosphorylation level were all significantly increased （ P ＜0.05）， whereas the positive area ratio of Bcl-2 protein， IL-10 level， and AMPK and GSK3β protein phosphorylation levels were significantly decreased （ P ＜0.05）. Compared with the model group， all NZN dose groups showed improvements in general condition and pathological damage， with quantitative indices partially restored， and the differences in quantitative indices in high-dose NZN group were statistically significant （ P ＜0.05）. CONCLUSIONS NZN can effectively improve learning and memory impairment in MCC model rats. The mechanism may be related to activating the AMPK/GSK3β pathway， inhibiting inflammatory response， reducing Tau protein phosphorylation level， and then repairing the neuronal injury.

This study elucidated the structure-activity relationships (SAR) of three distinct opioid ligand series at the μ-opioid receptor (μ-OR) and investigated the ligand-dependent role of arrestin in downstream signaling. Radioligand binding assays across 13 compounds revealed that high-affinity μ-OR binding is not restricted to a single chemical scaffold. For fentanyl analogs, SAR analysis identified four key structural determinants: the N-phenethyl group (R1) is essential for μ-OR binding, the piperidine 4-position (R2) is sterically constrained and tolerates only small substituents such as carbomethoxy, the acyl side chain (R3) tolerates diverse chemical modifications including alkyl, alkoxy, and heteroaryl groups without substantial loss of affinity, and para-substitution on the phenethyl ring (R4) with electron-withdrawing groups like fluorine is well-tolerated. Analysis of non-fentanyl scaffolds (2-Methyl AP-237, W-15, and brorphine) demonstrated that specific side-chain functionalization, rather than core scaffold architecture, primarily determines binding potency. Comparison of classical opioids further revealed that structural flexibility, exemplified by methadone, can confer superior binding affinity compared to the rigid morphine scaffold. Consistent with this structural diversity, the contribution of arrestins to ERK activation varied substantially across compounds, suggesting that μ-OR-biased signaling is not dictated exclusively by intrinsic receptor properties but emerges from the interplay between receptor conformation and ligandspecific structural features. Collectively, our results provide a molecular framework for understanding opioid pharmacology with important implications for rational drug design aimed at minimizing adverse effects while maintaining analgesic efficacy.

ObjectiveTo construct a prediction model for high responsiveness to short-term aerobic training in patients with Parkinson's disease (PD) based on dual-task gait assessment, and to provide evidence for identifying individuals who are most likely to benefit from such interventions. MethodsA total of 42 patients with PD who visited the outpatient clinic of Tianjin Huanhu Hospital between August 29, 2023 and December 19, 2024 were enrolled. All participants completed a 4-week home-based aerobic cycling training program and underwent dual-task gait assessments pre- and post-training. Patients were classified into high-response group (n = 12) and low-response group (n = 30) according to whether the improvement in gait speed reached the minimal clinically important difference of 0.1 m/s. The clinical validity of this grouping was verified by comparing differences in cardiopulmonary exercise testing parameters and dual-task gait indicators between the two groups pre- and post-training. Based on baseline characteristics, Firth's penalized maximum likelihood logistic regression was applied to construct a predictive model for high responsiveness, and the discriminative performance of the model was assessed preliminarily. ResultsThe high-response group showed significantly greater improvement in gait speed, step length, cadence and the anaerobic threshold to maximal oxygen uptake ratio after training compared with the low-response group (P < 0.05), confirming the clinical validity of the grouping. The baseline anaerobic threshold to maximal oxygen uptake ratio (OR = 3.348), body mass index (OR = 2.229) and age (OR = 0.428) demonstrated certain discriminative ability in the present sample. The area under the receiver operating characteristic curve was 0.831, with an overall prediction accuracy of 81.0%, specificity of 83.3% and sensitivity of 75.0%. Robustness of the model was confirmed via internal validation using the Bootstrap method, which suggested that the results were informative, but further validation was still required. ConclusionThe anaerobic threshold/maximal oxygen uptake ratio, body mass index and age may predict the response to short-term aerobic training in patients with PD.

Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry(MALDI-TOF MS)has a-chieved remarkable progress in diagnosis of infectious diseases in recent years,showing certain advantages in iden-tification of bacteria and fungi as well as analysis of macromolecules such as proteins.The application effectiveness of MALDI-TOF mass spectrometry in detection of infectious diseases,especially foodborne pathogenic bacteria in-fections,urinary tract infections,bloodstream infections,reproductive system infections as well as the drug resist-ance testing,was reviewed in the article so as to facilitate the diagnosis and treatment of infectious diseases.

Objective:To explore the application value of radiomics models based on MRI of vertebrae and paravertebral muscles in identifying potential vertebral fragility fracture risk in osteoporosis and osteopenia.Methods:This cross-sectional study collected data from patients who underwent both dual-energy X-ray absorptiometry (DXA) and lumbar MRI at the Third Affiliated Hospital of Southern Medical University between January 2014 and December 2023,retrospectively. Based on DXA results, patients were categorized into osteoporosis group ( n=302) and osteopenia group ( n=264), with fracture and non-fracture patients matched at 1∶1 ratio by propensity score matching based on age, gender, and body mass index. The fourth lumbar vertebra was selected as the region of interest (ROI) for the vertebral body, and the bilateral psoas major, erector spinae, and multifidus muscles were selected as the ROIs for the paraspinal muscles. A total of 7 259 radiomics features were extracted from these ROIs. The dataset was divided into a training set and a test set in an 8∶2 ratio by simple random sampling (osteoporosis group 241 and 61 cases, osteopenia group 211 and 53 cases). The T-score was used to establish the clinical model. After feature normalization and dimensionality reduction, logistic regression was applied to build three radiomics models: vertebral model, paraspinal muscle model, and vertebral-paraspinal muscle model. The T-score was then combined with the radiomics model that achieved the highest area under the receiver operating characteristic curve (AUC) in the test set to construct a clinical-radiomics combined model. Model performance was evaluated using the AUC. The DeLong test was used to compare the diagnostic efficacy between models. Results:In the test set, the vertebral-paravertebral muscle model achieved the highest AUC among radiomics models and was selected for combination with the T-score. In identifying potential vertebral fragility fractures of osteoporosis group, the AUC (95% CI) of the clinical model, vertebral model, paraspinal muscle model, vertebral-paraspinal muscle model, and clinical-radiomics model were 0.523 (0.373-0.672), 0.869 (0.779-0.959), 0.608 (0.464-0.752), 0.876 (0.791-0.961), and 0.860 (0.769-0.952), respectively. For osteopenia group, the corresponding AUC(95% CI) were 0.625 (0.467-0.783), 0.696 (0.547-0.845), 0.706 (0.563-0.848), 0.816 (0.702-0.930), and 0.820 (0.710-0.930). The DeLong test showed that the vertebral model for identifying the potential vertebral fracture risk in osteoporosis group had better performance than the paraspinal muscle model ( Z=3.28, P=0.001). While for osteopenia group, there was no significant difference in diagnostic performance between the vertebral model and the paraspinal muscle model ( Z=0.09, P=0.932). The recognition efficacy of the clinical model and the vertebral-paraspinal muscle model was significantly different ( Z=3.69, 1.98; P<0.001, P=0.047), while there was no significant difference between the clinical-radiomics combined model and the vertebral-paraspinal muscle model ( Z=1.51, 0.12; P=0.131, 0.904). Conclusion:The MRI-based vertebral-paraspinal muscle radiomics model can effectively identify osteoporosis or osteopenia patients with potential fragility fracture risk. In osteopenia group, the efficacy of the MRI radiomics models based on the vertebra and paraspinal muscles in identifying potential vertebral fragility fracture risk is comparable.

BACKGROUND:Steroid-induced osteonecrosis of the femoral head is closely related to ferroptosis in osteoblasts.Deer antler peptide can promote the survival and functional establishment of osteoclasts by inhibiting ferroptosis in osteoblasts,and has the potential to treat steroid-induced osteonecrosis of the femoral head,but its regulatory mechanism of ferroptosis in osteoblasts has not yet been clarified.OBJECTIVE:To investigate the mechanism by which deer antler peptide inhibits dexamethasone-induced ferroptosis in osteoblasts.METHODS:(1)Different concentration gradients of antler peptide and dexamethasone were used to intervene in MC3T3-E1 14 cells,and the cell activity was detected by cell counting kit-8 method to determine the effect concentration of antler peptide and dexamethasone.(2)MC3T3-E1 14 cells treated with dexamethasone(800 μmol/L)were intervened with different concentrations of gradient antler polypeptide,which were then divided into blank control group,dexamethasone group and dexamethasone+antler peptide group.Cell counting kit-8 method was used to calculate the effects of different concentrations of antler polypeptide on the proliferation of MC3T3-E1 14 cells.(3)Glutathione,superoxide dismutase,malondialdehyde,lipid peroxide,cellular iron,and reactive oxygen species levels in the blank control group,dexamethasone group and dexamethasone+antler peptide group were detected using kits.The protein expressions of glutathione peroxidase 4 and solute carrier family 7 member 11 were detected by western blot to verify the pathway by which antler polypeptide inhibits ferroptosis.RESULTS AND CONCIUSION:After cell activity was detected by cell counting kit-8 assay,antler peptide(10 mg/mL)and dexamethasone(800 μmol/L)were selected to treat MC3T3-E1 14 cells for 24 hours in subsequent experiments.After treatment with dexamethasone,malondialdehyde,lipid peroxide,cellular iron and reactive oxygen species levels were all increased(P<0.01),while glutathione content and superoxide dismutase activity were decreased and the protein expression of glutathione peroxidase 4 and solute carrier family 7 member 11 were also decreased(P<0.05-0.01).After antler peptide intervention,the changes in the above indexes were obviously reversed(P<0.05-0.01).To conclude,antler peptide may inhibit ferroptosis in osteoblasts by regulating the glutathione peroxidase 4/solute carrier family 7 member 11 axis,and thereby exert a therapeutic role in steroid-induced osteonecrosis of the femoral head.

Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry(MALDI-TOF MS)has a-chieved remarkable progress in diagnosis of infectious diseases in recent years,showing certain advantages in iden-tification of bacteria and fungi as well as analysis of macromolecules such as proteins.The application effectiveness of MALDI-TOF mass spectrometry in detection of infectious diseases,especially foodborne pathogenic bacteria in-fections,urinary tract infections,bloodstream infections,reproductive system infections as well as the drug resist-ance testing,was reviewed in the article so as to facilitate the diagnosis and treatment of infectious diseases.

Objective To investigate the diagnostic efficacy of fat fraction(FF)and T2* values of infrapatellar fat pad(IPFP)based on MR mDixon-Quant technique for knee osteoarthritis(KOA),and to analyze their related influencing factors.Methods A total of 178 knee joints from 114 volunteers were included and underwent knee joints X-ray examination and MR mDixon-Quant sequence scanning.The correlation between FF and T2* values of IPFP with gender,age,body mass index(BMI),and K-L grade was analyzed by Spearman's test and multiple linear regression.Receiver operating characteristic(ROC)curves were plotted to assess the diag-nostic efficacy of FF and T2* values for KOA.Results FF value of IPFP was negatively correlated with age,BMI,and K-L grade(r=-0.470,-0.276,-0.679,P＜0.001),and T2* value was also negatively correlated with age,BMI,and K-L grade(r=-0.291,-0.173,-0.505,P＜0.001).Multiple linear regression analysis results showed that only K-L grade had a statistically significant correlation with FF and T2* values(P＜0.001).ROC curve analysis indicated that the area under the curve(AUC)for diagnosing KOA using the FF and T2* values of IPFP were 0.859 and 0.767,respectively,with sensitivity of 0.878 and 0.841,and specificity of 0.719 and 0.573,respectively.The combined diagnosis had an AUC of 0.855,a sensitivity of 0.625,and a specificity of 0.963,improving the diagnostic specificity for KOA.Conclusion FF and T2* values of IPFP can serve as objective imaging indicators for KOA assessment,and their reduction is correlated with the progress of age,BMI,and K-L grade,of which the K-L grade is an independent influencing factor.The combination of FF and T2 can improve the diagnostic specificity of KOA,and provide a quantitative basis for early KOA detection and severity stratification.

Objective To investigate the diagnostic efficacy of fat fraction(FF)and T2* values of infrapatellar fat pad(IPFP)based on MR mDixon-Quant technique for knee osteoarthritis(KOA),and to analyze their related influencing factors.Methods A total of 178 knee joints from 114 volunteers were included and underwent knee joints X-ray examination and MR mDixon-Quant sequence scanning.The correlation between FF and T2* values of IPFP with gender,age,body mass index(BMI),and K-L grade was analyzed by Spearman's test and multiple linear regression.Receiver operating characteristic(ROC)curves were plotted to assess the diag-nostic efficacy of FF and T2* values for KOA.Results FF value of IPFP was negatively correlated with age,BMI,and K-L grade(r=-0.470,-0.276,-0.679,P＜0.001),and T2* value was also negatively correlated with age,BMI,and K-L grade(r=-0.291,-0.173,-0.505,P＜0.001).Multiple linear regression analysis results showed that only K-L grade had a statistically significant correlation with FF and T2* values(P＜0.001).ROC curve analysis indicated that the area under the curve(AUC)for diagnosing KOA using the FF and T2* values of IPFP were 0.859 and 0.767,respectively,with sensitivity of 0.878 and 0.841,and specificity of 0.719 and 0.573,respectively.The combined diagnosis had an AUC of 0.855,a sensitivity of 0.625,and a specificity of 0.963,improving the diagnostic specificity for KOA.Conclusion FF and T2* values of IPFP can serve as objective imaging indicators for KOA assessment,and their reduction is correlated with the progress of age,BMI,and K-L grade,of which the K-L grade is an independent influencing factor.The combination of FF and T2 can improve the diagnostic specificity of KOA,and provide a quantitative basis for early KOA detection and severity stratification.

BACKGROUND:Steroid-induced osteonecrosis of the femoral head is closely related to ferroptosis in osteoblasts.Deer antler peptide can promote the survival and functional establishment of osteoclasts by inhibiting ferroptosis in osteoblasts,and has the potential to treat steroid-induced osteonecrosis of the femoral head,but its regulatory mechanism of ferroptosis in osteoblasts has not yet been clarified.OBJECTIVE:To investigate the mechanism by which deer antler peptide inhibits dexamethasone-induced ferroptosis in osteoblasts.METHODS:(1)Different concentration gradients of antler peptide and dexamethasone were used to intervene in MC3T3-E1 14 cells,and the cell activity was detected by cell counting kit-8 method to determine the effect concentration of antler peptide and dexamethasone.(2)MC3T3-E1 14 cells treated with dexamethasone(800 μmol/L)were intervened with different concentrations of gradient antler polypeptide,which were then divided into blank control group,dexamethasone group and dexamethasone+antler peptide group.Cell counting kit-8 method was used to calculate the effects of different concentrations of antler polypeptide on the proliferation of MC3T3-E1 14 cells.(3)Glutathione,superoxide dismutase,malondialdehyde,lipid peroxide,cellular iron,and reactive oxygen species levels in the blank control group,dexamethasone group and dexamethasone+antler peptide group were detected using kits.The protein expressions of glutathione peroxidase 4 and solute carrier family 7 member 11 were detected by western blot to verify the pathway by which antler polypeptide inhibits ferroptosis.RESULTS AND CONCIUSION:After cell activity was detected by cell counting kit-8 assay,antler peptide(10 mg/mL)and dexamethasone(800 μmol/L)were selected to treat MC3T3-E1 14 cells for 24 hours in subsequent experiments.After treatment with dexamethasone,malondialdehyde,lipid peroxide,cellular iron and reactive oxygen species levels were all increased(P<0.01),while glutathione content and superoxide dismutase activity were decreased and the protein expression of glutathione peroxidase 4 and solute carrier family 7 member 11 were also decreased(P<0.05-0.01).After antler peptide intervention,the changes in the above indexes were obviously reversed(P<0.05-0.01).To conclude,antler peptide may inhibit ferroptosis in osteoblasts by regulating the glutathione peroxidase 4/solute carrier family 7 member 11 axis,and thereby exert a therapeutic role in steroid-induced osteonecrosis of the femoral head.