BACKGROUND:Studies have shown that metformin has anti-inflammatory,anti-tumor,anti-aging and vasoprotective effects,and can inhibit the progression of osteoarthritis,but its specific mechanism of action remains unclear. OBJECTIVE:To investigate the mechanism of metformin on cartilage protection in a rat model of osteoarthritis. METHODS:Forty male Sprague-Dawley rats were randomly divided into four groups(n=10 per group):blank,control,sham-operated,and metformin groups.The blank group did not undergo any surgery.In the sham-operated group,the joint cavity was exposed.In the model group and the metformin group,the modified Hulth method was used to establish the osteoarthritis model.At 1 day after modeling,the rats in the metformin group were given 200 mg/kg/d metformin by gavage,and the model,blank,and sham-operated groups were given normal saline by gavage.Administration in each group was given for 4 weeks consecutively.Hematoxylin-eosin staining,toluidine blue staining,and safranin O-fast green staining were used to observe the morphological structure of rat knee joints.Immunohistochemical staining and western blot were used to detect the protein expression of SOX9,type Ⅱ collagen,a disintegrin and metalloproteinase with thrombospondin motifs 5(ADAMTS5),Beclin1,P62,phosphatidylinositol 3-kinase(PI3K),p-PI3K,protein kinase B(AKT),p-AKT,mammalian target of rapamycin(Mtor),and p-Mtor in rat cartilage tissue. RESULTS AND CONCLUSION:The results of hematoxylin-eosin,toluidine blue and safranin O-fast green staining showed smooth cartilage surface of the knee joints and normal histomorphology in the blank group and the sham-operated group,while in the model group,there was irregular cartilage surface of the knee joint and cartilage damage,with a decrease in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.In the metformin group,there was a significant improvement in the damage to the structure of the cartilage in the knee joints of the rats,and the cartilage surface tended to be smooth,with an increase in the number of chondrocytes and the content of proteoglycans in the cartilage matrix.Immunohistochemistry staining and western blot results showed that compared with the control and sham-operated groups,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the model group was significantly decreased(P<0.05).Conversely,the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly increased(P<0.05).Furthermore,compared with the model group,the expression of SOX9,type Ⅱ collagen,and Beclin1 proteins in the cartilage tissue of rats in the metformin group was significantly increased(P<0.05),while the expression of ADAMTS5,P62,as well as p-PI3K,p-AKT,and p-Mtor proteins was significantly decreased(P<0.05).To conclude,Metformin can improve the autophagy activity of chondrocytes and reduce the degradation of cartilage matrix in osteoarthritis rats by inhibiting the activation of PI3K/AKT/Mtor signaling pathway,thus exerting a protective effect on articular cartilage.

BACKGROUND:Metformin is currently considered the first-line medication for the treatment of type 2 diabetes.Metformin may delay the progression of osteoarthritis,but its specific mechanism of action remains unclear.OBJECTIVE:To evaluate the therapeutic effects and the related action mechanisms of metformin on osteoarthritis in rats.METHODS:(1)Network pharmacology:Potential common targets for metformin,osteoarthritis,and ferroptosis were screened using the CTD,SwissTargetPrediction,GeneCards,and OMIM databases.After importing the targets into the STRING database,protein-protein interaction analysis was conducted to identify the key targets for metformin,osteoarthritis,and ferroptosis.(2)Molecular docking:P53 and its downstream factor SLC7A11 protein structures in PDB format were downloaded from the PDB database.The 2D structure of metformin was converted to a 3D structure,and molecular docking of metformin with the proteins was performed using Discovery Studio 2019 Client.(3)In vivo experiments:Thirty male SD rats were randomly divided into three groups(n=10).The blank group did not receive surgery.The osteoarthritis model was established using the modified Hulth method for the model and metformin groups.One day after the surgery,rats in the metformin group were gavaged with metformin 200 mg/kg per day,while the blank and model groups were gavaged with physiological saline.Treatment continued for 4 weeks.Hematoxylin-eosin staining and Safranin O-fast green staining were used to observe the pathological morphology and structure of the knee cartilage,and Mankin scoring was performed.ELISA was used to measure the levels of tumor necrosis factor-α and interleukin-6 in the serum.The microplate method was used to measure serum ferroptosis-related indicators,including glutathione,malondialdehyde,and Fe2+.Immunofluorescence staining,western blot assay,and real-time qPCR were used to detect the protein and mRNA expression of P53,SLC7A11,glutathione peroxidase 4,proteoglycans,and matrix metalloproteinase 13 in the cartilage tissue of the rats.RESULTS AND CONCLUSION:(1)A total of 96 intersecting targets among metformin,osteoarthritis,and ferroptosis were identified.After protein-protein interaction analysis,77 potential targets were found.Further screening identified the core targets as TP53,AKT1,JUN,interleukin-6,MYC,interleukin-1β,and tumor necrosis factor-α,among others.(2)Docking analysis results showed that metformin bound strongly and stably with P53 and its downstream factor SLC7A11.(3)In the model group,the knee cartilage surface was irregular,with cartilage tissue defects and reduced chondrocyte numbers.Compared to the model group,the knee cartilage structure damage in the metformin group was significantly improved,with a smoother cartilage surface and increased chondrocyte numbers.The Mankin score in the model group was significantly higher than that in the blank group,while the Mankin score in the intervention group was significantly lower than that in the model group.(4)Compared with the model group,the metformin group had significantly lower levels of tumor necrosis factor-α,interleukin-6,malondialdehyde,and Fe2+,and significantly higher glutathione levels.(5)Compared to the model group,the metformin group had significantly increased protein and mRNA expression of SLC7A11,glutathione peroxidase 4,and proteoglycans,and significantly decreased protein and mRNA expression of P53 and matrix metalloproteinase 13 in their cartilage tissue.(6)The results indicate that metformin can effectively improve cartilage damage in osteoarthritis rats and alleviate chondrocyte ferroptosis by inhibiting the aberrantly activated P53/SLC7A11/glutathione peroxidase 4 signaling pathway.This improvement in chondrocyte iron metabolism and lipid peroxidation response further reduces cartilage matrix degradation and prevents further cartilage damage and inflammatory response.

Objective:To explore the clinical characteristics of patients with metastatic gastric tumor and to differentiate them from those with primary malignant gastric tumors.Methods:This study retrospectively analyzed the clinical data of 21 patients with metastatic gastric tumor confirmed by gastroscopy biopsy and pathology.The clinical manifestations,gastroscopy characteristics,pathological results,and the time interval between the diagnosis of primary malignant tumor and the confirmation of gastric metastasis were summarized.Results:The patient primarily exhibited symptoms related to gastric involvement;gastroscopy findings resembled those of primary malignant tumors of the stomach;pathological results were consistent with primary malignant tumors;the time interval between the diagnosis of primary cancer and the confirmation of metastatic gastric tumor varied significantly,ranging from up to 18 years to simultaneous detection.Conclusion:Metastatic gastric tumors are similar to primary malignant tumors of the stomach in terms of clinical manifestations and endoscopic features,making clinical differentiation challenging.The main approach for distinguishing them is based on pathological examination.

Objectives:To explore the feasibility of zero-ray radiofrequency catheter ablation for paroxymal atrial fibrillation under the guidance of transthoracic echocardiography combined with three-dimensional mapping system.Methods:This is a single-center prospective observational study.A total of 12 patients with paroxysmal atrial fibrillation who underwent radiofrequency catheter ablation in Fuwai Hospital,Chinese Academy of Medical Sciences from June 1,2024 to September 30,2024 were included.All patients underwent successful percutaneous puncture,atrial septal puncture under the guidance of transthoracic echocardiography,and all patients underwent left atrial modeling and discharge ablation under the guidance of transthoracic echocardiography combined with three-dimensional mapping system.The disappearance of pulmonary vein potential was confirmed after the ablation operation and as the ablation endpoint and successful ablation marker.The operation results and 1-month and 3-month follow-up results of the patients were observed.Results:There were 12 patients with paroxysmal atrial fibrillation,9 males and 3 females,aged(56.8±11.2)years,with a history of paroxysmal atrial fibrillation(4.2±2.3)years.The mean left atrial diameter was(36.5±2.5)mm,the left ventricular end-diastolic diameter was(47.8±4.1)mm,and the left ventricular ejection fraction was 55%-65%.The mean overall operation time was(102.25±14.51)min,the ultrasound operation time was(29.58±6.23)min,and the catheter operation time was(33.08±4.10)min.All patients completed circumferential pulmonary vein isolation without intraoperative complications.The hospitalization time was 2-6 days.At the 1-month follow-up after ablation,all patients showed sinus rhythm on 24-hour ambulatory electrocardiogram,and 2 patients had occasional atrial premature contractions without recurrence of atrial fibrillation.At the 3-month follow-up,two patients had occasional premature atrial contractions,and no recurrence of atrial fibrillation was recorded on the electrocardiogram of all patients.Conclusions:It is feasible to complete radiofrequency catheter ablation of paroxysmal atrial fibrillation under the guidance of transthoracic echocardiography combined with three-dimensional mapping system.

Objectives:To explore the feasibility of zero-ray radiofrequency catheter ablation for paroxymal atrial fibrillation under the guidance of transthoracic echocardiography combined with three-dimensional mapping system.Methods:This is a single-center prospective observational study.A total of 12 patients with paroxysmal atrial fibrillation who underwent radiofrequency catheter ablation in Fuwai Hospital,Chinese Academy of Medical Sciences from June 1,2024 to September 30,2024 were included.All patients underwent successful percutaneous puncture,atrial septal puncture under the guidance of transthoracic echocardiography,and all patients underwent left atrial modeling and discharge ablation under the guidance of transthoracic echocardiography combined with three-dimensional mapping system.The disappearance of pulmonary vein potential was confirmed after the ablation operation and as the ablation endpoint and successful ablation marker.The operation results and 1-month and 3-month follow-up results of the patients were observed.Results:There were 12 patients with paroxysmal atrial fibrillation,9 males and 3 females,aged(56.8±11.2)years,with a history of paroxysmal atrial fibrillation(4.2±2.3)years.The mean left atrial diameter was(36.5±2.5)mm,the left ventricular end-diastolic diameter was(47.8±4.1)mm,and the left ventricular ejection fraction was 55%-65%.The mean overall operation time was(102.25±14.51)min,the ultrasound operation time was(29.58±6.23)min,and the catheter operation time was(33.08±4.10)min.All patients completed circumferential pulmonary vein isolation without intraoperative complications.The hospitalization time was 2-6 days.At the 1-month follow-up after ablation,all patients showed sinus rhythm on 24-hour ambulatory electrocardiogram,and 2 patients had occasional atrial premature contractions without recurrence of atrial fibrillation.At the 3-month follow-up,two patients had occasional premature atrial contractions,and no recurrence of atrial fibrillation was recorded on the electrocardiogram of all patients.Conclusions:It is feasible to complete radiofrequency catheter ablation of paroxysmal atrial fibrillation under the guidance of transthoracic echocardiography combined with three-dimensional mapping system.

BACKGROUND:Metformin is currently considered the first-line medication for the treatment of type 2 diabetes.Metformin may delay the progression of osteoarthritis,but its specific mechanism of action remains unclear.OBJECTIVE:To evaluate the therapeutic effects and the related action mechanisms of metformin on osteoarthritis in rats.METHODS:(1)Network pharmacology:Potential common targets for metformin,osteoarthritis,and ferroptosis were screened using the CTD,SwissTargetPrediction,GeneCards,and OMIM databases.After importing the targets into the STRING database,protein-protein interaction analysis was conducted to identify the key targets for metformin,osteoarthritis,and ferroptosis.(2)Molecular docking:P53 and its downstream factor SLC7A11 protein structures in PDB format were downloaded from the PDB database.The 2D structure of metformin was converted to a 3D structure,and molecular docking of metformin with the proteins was performed using Discovery Studio 2019 Client.(3)In vivo experiments:Thirty male SD rats were randomly divided into three groups(n=10).The blank group did not receive surgery.The osteoarthritis model was established using the modified Hulth method for the model and metformin groups.One day after the surgery,rats in the metformin group were gavaged with metformin 200 mg/kg per day,while the blank and model groups were gavaged with physiological saline.Treatment continued for 4 weeks.Hematoxylin-eosin staining and Safranin O-fast green staining were used to observe the pathological morphology and structure of the knee cartilage,and Mankin scoring was performed.ELISA was used to measure the levels of tumor necrosis factor-α and interleukin-6 in the serum.The microplate method was used to measure serum ferroptosis-related indicators,including glutathione,malondialdehyde,and Fe2+.Immunofluorescence staining,western blot assay,and real-time qPCR were used to detect the protein and mRNA expression of P53,SLC7A11,glutathione peroxidase 4,proteoglycans,and matrix metalloproteinase 13 in the cartilage tissue of the rats.RESULTS AND CONCLUSION:(1)A total of 96 intersecting targets among metformin,osteoarthritis,and ferroptosis were identified.After protein-protein interaction analysis,77 potential targets were found.Further screening identified the core targets as TP53,AKT1,JUN,interleukin-6,MYC,interleukin-1β,and tumor necrosis factor-α,among others.(2)Docking analysis results showed that metformin bound strongly and stably with P53 and its downstream factor SLC7A11.(3)In the model group,the knee cartilage surface was irregular,with cartilage tissue defects and reduced chondrocyte numbers.Compared to the model group,the knee cartilage structure damage in the metformin group was significantly improved,with a smoother cartilage surface and increased chondrocyte numbers.The Mankin score in the model group was significantly higher than that in the blank group,while the Mankin score in the intervention group was significantly lower than that in the model group.(4)Compared with the model group,the metformin group had significantly lower levels of tumor necrosis factor-α,interleukin-6,malondialdehyde,and Fe2+,and significantly higher glutathione levels.(5)Compared to the model group,the metformin group had significantly increased protein and mRNA expression of SLC7A11,glutathione peroxidase 4,and proteoglycans,and significantly decreased protein and mRNA expression of P53 and matrix metalloproteinase 13 in their cartilage tissue.(6)The results indicate that metformin can effectively improve cartilage damage in osteoarthritis rats and alleviate chondrocyte ferroptosis by inhibiting the aberrantly activated P53/SLC7A11/glutathione peroxidase 4 signaling pathway.This improvement in chondrocyte iron metabolism and lipid peroxidation response further reduces cartilage matrix degradation and prevents further cartilage damage and inflammatory response.

Objective:To explore the clinical characteristics of patients with metastatic gastric tumor and to differentiate them from those with primary malignant gastric tumors.Methods:This study retrospectively analyzed the clinical data of 21 patients with metastatic gastric tumor confirmed by gastroscopy biopsy and pathology.The clinical manifestations,gastroscopy characteristics,pathological results,and the time interval between the diagnosis of primary malignant tumor and the confirmation of gastric metastasis were summarized.Results:The patient primarily exhibited symptoms related to gastric involvement;gastroscopy findings resembled those of primary malignant tumors of the stomach;pathological results were consistent with primary malignant tumors;the time interval between the diagnosis of primary cancer and the confirmation of metastatic gastric tumor varied significantly,ranging from up to 18 years to simultaneous detection.Conclusion:Metastatic gastric tumors are similar to primary malignant tumors of the stomach in terms of clinical manifestations and endoscopic features,making clinical differentiation challenging.The main approach for distinguishing them is based on pathological examination.

Objective: To explore the relationship between depressive symptoms, negative life events and resilience among primary and secondary school teachers, so as to provide a reference for mental health promotion in school teachers. Methods: During November to December 2022, a questionnaire survey was conducted using convenient cluster sampling method to select 11 332 in service teachers from 38 schools in 8 provinces (cities) including Beijing, Guangdong, Anhui, Hubei, Sichuan, Xinjiang, Liaoning, and Heilongjiang. The Patient Health Questionnaire-9 items, a self developed 21-item Adverse Life Events questionnaire, and a 10-item Conner-Davidson Resilience Scale were used to assess depressive symptoms, experiences of negative life events, and resilience levels of the teachers, respectively. The relationship between depressive symptoms, negative life events and psychological resilience were analyzed by multiple linear regression and stratified regression. Results: The detection rate of depressive symptoms among primary and secondary school teachers was 14.0%. Negative life events of primary and secondary school teachers were positively correlated with depressive symptoms ( r =0.35), while psychological resilience was negatively correlated with depressive symptoms ( r =-0.45) ( P <0.05). After adjusting for possible covariates including gender and marital status, negative life events were positively correlated with depressive symptoms ( β=0.22, P <0.01). Resilience played a moderating role in the association of negative life events with depressive symptoms among primary and secondary school teachers ( B=-0.15, P <0.01). Conclusions Negative life events experiences are associated with higher level of depressive symptoms among school teachers. However, resilience might mitigate the negative effects of negative life events on depressive symptoms, playing a protective role in teachers mental health.

BACKGROUND:Previous research by the research team found that domestically produced porous tantalum is beneficial for early adhesion and proliferation of MG63 cells,and can be used as a scaffold material for bone tissue engineering. OBJECTIVE:To investigate the effect of domestic porous tantalum modified by osteogenic induction factor slow-release system on the adhesion,proliferation,and differentiation of MG63 cells. METHODS:Osteogenic induction factor slow-release system was constructed by adding 15%volume fraction of osteogenic factor solution to poly(lactic-co-glycolic-acid)gel.The passage 3 MG63 cells were inoculated on a porous tantalum surface(control group),porous tantalum surface coated with poly(lactic-co-glycolic-acid)copolymer gel(gel group),and porous tantalum surface coated with osteoblastic induction factor slow-release system(slow-release system group),and co-cultured for 5 days.The surface cytoskeleton of the material was observed by phalloidine staining.Cell proliferation was detected by flow cytometry.Western blot assay and RT-qPCR were used to detect the protein and mRNA expressions of type Ⅰ collagen,osteopontin,and RUNX-2 on the surface cells of the material. RESULTS AND CONCLUSION:(1)Phalloidine staining showed that MG63 cells adhered to and grew on the surface and inside of the three groups of porous tantalum,and the matrix secreted by the cells covered the surface of the material.(2)Flow cytometry showed that the cell proliferation in the slow-release system group was faster than that in the control group and the gel group(P<0.05).(3)Western blot assay and RT-qPCR showed that the protein and mRNA expressions of type Ⅰ collagen,osteopontin,and RUNX-2 in the slow-release system group were higher than those in the control group and gel group(P<0.05).(4)The results showed that the domestic porous tantalum modified by the osteogenic induction factor slow-release system was beneficial to the adhesion,proliferation,and differentiation of MG63 osteoblasts.

Objectives:To explore the risk factors for recurrent in-stent restenosis(R-ISR)in patients with coronary heart disease after percutaneous coronary intervention(PCI)and to develop a risk prediction model for R-ISR using a nomogram. Methods:All patients treated for ISR at the Fuwai Hospital,Chinese Academy of Medical Sciences from January to December 2017 were eligible for this study.A total of 1 102 ISR patients were included for analysis.Based on the recurrence of ISR after PCI,patients were divided into R-ISR group and non-R-ISR group.Univariate Cox regression analyses,LASSO regression analyses,and the combination of clinical experience were used to select predictors of R-ISR.A multivariate Cox regression model was used to analyze the independent risk factors of R-ISR and to develop a risk prediction model. Results:The median follow-up duration for participants was 1 264(1 169,1 334)days,the incidence rate of R-ISR after PCI was 10.1%.Multivariate Cox regression analysis showed that age(HR=0.98,95%CI:0.96-0.99),total bilirubin(HR=0.95,95%CI:0.91-0.99),apolipoprotein A1(HR=0.08,95%CI:0.02-0.42),high-sensitivity C-reactive protein(HR=1.05,95%CI:1.01-1.10),and reference vessel diameter(HR=0.65,95%CI:0.44-0.98)were independent determinants of R-ISR.Accordingly,the R-ISR risk prediction model was developed with a nomogram,the AUC of this model to predicto R-ISR was 0.70(95%CI:0.64-0.77). Conclusions:Coronary heart disease patients with younger age,lower levels of total bilirubin and apolipoprotein A1,smaller vessel diameter,and higher levels of high-sensitivity C-reactive protein are at higher risk of R-ISR.The developed visual risk prediction model for R-ISR shows promising predictive performance but still requires further optimization and validation.