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.

Objective To explore the correlation between triglyceride glucose(TyG)index and per-cutaneous coronary intervention(PCI)following drug treatment in elderly patients with unstable angina pectoris(UAP).Methods A total of 221 elderly UAP patients admitted to the Hyperbaric Oxygen Department of the First Medical Center of Chinese PLA General Hospital from March 2016 to March 2024 were enrolled,and based on the tertiles of the TyG index,they were divided into low,medium and high TyG index groups(the index:≤8.48,8.49-8.92,＞8.92;with 74,74 and 73 cases,respectively).Clinical data of all patients were collected,and whether undergoing PCI after discharge was defined as the endpoint event.The follow-up ended on May 10,2024.The clini-cal data were compared in the three groups.Kaplan-Meier survival curves were plotted to compare the survival rates among the groups,and Cox proportional hazards regression model was em-ployed to analyze the influencing factors for occurrence of endpoint event.Results There were significant differences in the three groups in terms of TyG index,BMI,diabetes,FPG,TC,TG,LDL-C,HDL-C,HbA1c,NT-proBNP,and incidence of endpoint event(P＜0.05,P＜0.01).Univa-riate Cox proportional hazards regression analysis showed that the TyG index,diabetes,and HbA1c were risk factors for endpoint events in elderly patients with UAP(HR=2.523,95％CI:1.593-3.996;HR=2.543,95％CI:1.263-5.118;HR=1.434,95％CI:1.159-1.774).Further multivariate Cox proportional hazards regression analysis showed that,after adjusting for diabetes and HbA1c,the TyG index was an independent risk factor for PCI after discharge in UAP patients(HR=2.023,95％CI:1.209-3.384).Conclusion In elderly UAP patients receiving drug treat-ment,a high TyG index is positively correlated with undergoing PCI after discharge,and the index is an independent risk factor for PCI in them.

Aim To explore the influence of demethy-lase fat mass and obesity-related genes(FTO)on the abnormal contractile function of diabetic coronary smooth muscle.Methods Smooth muscle specific FTO knockout mice(FTOSMKO)were prepared by Cre-loxP recombinant technology.They were divided into four groups:control(WT)group,diabetes model group(DM),FTO knockout group(FTOSMKO),and FTOSMKO diabetic group(FTOSMKO-DM),with 15 mice in each group.Diabetic mice were prepared by intraperitoneal injection of streptozotocin(STZ);the remaining mice were injected with an equal amount of citric acid-sodi-um citrate buffer.The effects of 5-HTon the contractile response of coronary artery smooth muscle in the four groups of mice were observed by the technique of small-vessel ring tensiometry.Western blot and Dot blot were used to detect the changes of FTO protein and N6-methyladenine(m6A)methylation modification levels in mouse vascular tissues.Results Compared with the WT group,the DM group had significantly higher blood glucose(P＜0.01)and lower body weight(P＜0.05);the level of FTO protein in aorta of DM group increased(P＜0.01),and the level of m6A methylation modification decreased(P＜0.01).The 5-HT-induced contractile response significantly de-creased in the DM group compared with the WT group(P＜0.01),whereas the contractile response signifi-cantly increased in the FTOSMKO-DM group compared with the DM group(P＜0.01);the non-L-type calci-um channel-mediated vascular smooth muscle contrac-tile response was enhanced in the FTOSMKO-DM group,among which,the contractions induced by 1,4,5-triphosphate inositol receptor(IP3R)and caffeine-ac-tivated ranine receptor(RyR)mediated by sarcoplas-mic reticulum calcium release both significantly in-creased(P＜0.05).Conclusions Specific knock-down of smooth muscle FTO improves coronary artery responsiveness to the vasoconstrictor 5-HT in diabetic mice,which may be related to abnormalities in the FTO-mediated 5-HT receptor signaling pathway.

Objective To explore the correlation between triglyceride glucose(TyG)index and per-cutaneous coronary intervention(PCI)following drug treatment in elderly patients with unstable angina pectoris(UAP).Methods A total of 221 elderly UAP patients admitted to the Hyperbaric Oxygen Department of the First Medical Center of Chinese PLA General Hospital from March 2016 to March 2024 were enrolled,and based on the tertiles of the TyG index,they were divided into low,medium and high TyG index groups(the index:≤8.48,8.49-8.92,＞8.92;with 74,74 and 73 cases,respectively).Clinical data of all patients were collected,and whether undergoing PCI after discharge was defined as the endpoint event.The follow-up ended on May 10,2024.The clini-cal data were compared in the three groups.Kaplan-Meier survival curves were plotted to compare the survival rates among the groups,and Cox proportional hazards regression model was em-ployed to analyze the influencing factors for occurrence of endpoint event.Results There were significant differences in the three groups in terms of TyG index,BMI,diabetes,FPG,TC,TG,LDL-C,HDL-C,HbA1c,NT-proBNP,and incidence of endpoint event(P＜0.05,P＜0.01).Univa-riate Cox proportional hazards regression analysis showed that the TyG index,diabetes,and HbA1c were risk factors for endpoint events in elderly patients with UAP(HR=2.523,95％CI:1.593-3.996;HR=2.543,95％CI:1.263-5.118;HR=1.434,95％CI:1.159-1.774).Further multivariate Cox proportional hazards regression analysis showed that,after adjusting for diabetes and HbA1c,the TyG index was an independent risk factor for PCI after discharge in UAP patients(HR=2.023,95％CI:1.209-3.384).Conclusion In elderly UAP patients receiving drug treat-ment,a high TyG index is positively correlated with undergoing PCI after discharge,and the index is an independent risk factor for PCI in them.

Objective To analyze the research status and hotspots in the field of astragalus polysaccharides;To provide references for further research.Methods Research literature about astragalus polysaccharides was retrieved from CNKI,Wanfang Data,VIP,PubMed,and Web of Science databases from 1st,Jan.2013 to 1st,July 2023.NoteExpress 3.7 software was used to manage the literature and ultimately establish a database.Excel 2019,CiteSpace 6.2.2R and VOSviewer 1.6.18 were used to visually analyze the publication volume,authors,institutions,and keywords of the included literature.Results A total of 2 462 articles were included,with 1 284 Chinese articles and 1 178 English articles.The main research institutions were Gansu University of Chinese Medicine,Shandong University of Traditional Chinese Medicine,and Beijing University of Chinese Medicine.The core authors of Chinese literature were Liu Yongqi,Wang Hongxin,Lu Meili,etc.The core authors of English literature included Zhang Wei,Li Ke,Yang Xiaojun,etc.High-frequency keywords of Chinese literature included Astragali Radix,rats,polysaccharides,cell apoptosis,and oxidative stress,etc.High frequency keywords in English literature included expression,in vitro,oxidative stress,apoptosis,etc.Conclusion The research on astragalus polysaccharides focuses on their pharmacological effects and mechanisms.Intestinal flora,immune regulation,autophagy and apoptosis are the hot action mechanisms in this field.The focus of disease research involves tumor and diabetes,and antiviral,anti infection and other pharmacological effects are the research trend.

Objective To investigate the relationship of TyG index and IC.Methods A cross-sectional study was conducted with 1000 older adults living in Wanshou Road Community from May to December 2023.Finally 820 participants were enrolled,and based on the TyG index,they were divided into lower TyG index group(≤7.349,404 cases)and higher TyG index group(＞7.349,416 cases).After PSM,there were only 522 participants subjected,including 261 individuals in the lower TyG index group 1 (≤7.349)and 416 ones in the higher TyG index group 2(＞7.349).Univariate and multivariate logistic regression analyses were used to assess the correlation between IC and the TyG index as both continuous and categorical variables.PSM was employed to eliminate the confounding effects of covariates to identify the relationship between TyG index and IC in different categories.Results Before PSM,the neutrophil count,WBC count,and Hcy,FPG,TC,TG and HbA1c levels were significantly lower,and lymphocyte count,monocyte count,and AST level were obviously higher in the low TyG index group than the high TyG index group(P＜0.05,P＜0.01).After PSM,the low TyG index group still had notably lower FPG,TG and HbA1c than the high TyG index group(P＜0.05,P＜0.01).ROC curve analysis revealed that the cutoff value of TyG index was 7.349.Taking 7.349 as the cutoff value and TyG index as the cate-gorical variable,multivariate logistic regression analysis displayed that TyG index was correlated with IC[OR=3.921,95％CI:2.800-5.491,P=0.001(Model 1);OR=2.744,95％CI:1.739-4.329,P=0.001(Model 2);OR=2.744,95％CI:1.805-4.171,P=0.001(Model 3);OR=2.722,95％CI:1.530-4.843,P=0.001(after PSM)],indicating that TyG index remains an independent risk factor for IC.Conclusion IC is still correlated with TyG index in community-dwelling elderly individuals under different baseline conditions after adjusting for relevant laboratory indicators.As an indicator generated from routine blood test,TyG index has advantages in terms of cost and time.With further validation,TyG may provide a direction for studying IC prediction.

OBJECTIVE To design and synthesize rifamycin S derivatives and load them into milk exosomes to evaluate their in vitro antimicrobial activity.METHODS Rifamycin S derivatives were synthe-sized and characterized by mass spectrometry and NMR.Using the dilution assay method,the inhibitory activity of each rifamycin S derivatives molecule against Staphylococcus aureus and Pseudomonas aerugi-nosa was determined,and the IC50 was calculated.Derivatives molecules with excellent antimicrobial activity were selected and loaded into milk exosomes using the ultrasonication method,resulting in the preparation of milk exosome-loaded rifamycin S derivatives.The antimicrobial activity against Staphylo-coccus aureus was determined using the dilution assay method.The inhibitory effect of the exosome-loaded rifamycin S derivatives on Staphylococcus aureus residing within macrophages was detected using the plate colony counting method.RESULTS Three rifamycin S derivatives were successfully designed and synthesized,which demonstrated superior antimicrobial activity against Staphylococcus aureus(the parent compound's antimicrobial activity is merely from 1/20 to 1/80 of that of the three rifamycin S derivatives)and Pseudomonas aeruginosa(the parent compound's antimicrobial activity is only 1/14 and 1/9 of that of compound 1 and compound 3)compared to the parent compound.The loading of milk exosomes with the rifamycin S derivatives compound 3 was successfully achieved,with a loading efficiency of 10.9％.The antimicrobial activity of the compound after exosome loading was significantly enhanced against Staphylococcus aureus in vitro and against Staphylococcus aureus residing within macrophages(P＜0.01).CONCLUSION The designed and synthesized derivatives of rifamycin S possess stronger anti-microbial activity,and their antibacterial efficacy against both extracellular and intracellular bacteria can be further enhanced after loading into exosomes.

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 investigate the use of vascular access among the maintenance hemodialysis(MHD)pa-tients and observe the impact on complications so as to provide bases for standardized clinical management and ma-intenance of vascular access.METHODS The MHD patients who were treated in hemodialysis center of The Affili-ated Hospital of North Sichuan Medical College from Jan.2015 to Jan.2024 were recruited as the research sub-jects.The types of vascular access and incidence rates of complications caused by the vascular access were retro-spectively analyzed.RESULTS A total of 2 040 MHD patients who were treated with the vascular access were en-rolled in the study,1 795(87.99％)of whom were autogenous arteriovenous fistula(AVF),80(3.92％)were tunnel-cuffed catheter(TCC),and 28(1.37％)were arteriovenous graft(AVG),126(6.18％)were non-cuffed catheter(NCC),and 11(0.54％)were arteriovenous direct puncture.The incidence of complications of the TCC group was 32.50％,higher than 16.88％of the AVF group and 19.84％of the NCC group,and there was signifi-cant difference(x2=12.915,4.209;P＜0.001,0.040);there was no significant difference in the incidence of com-plications between the AVF group(16.88％)and the NCC group(19.84％)(x2=0.730,P=0.393).CONCLUSIONS AVF is the major vascular access for the MHD patients,and the incidence of complications is rel-atively high among the patients treated with TCC.It is necessary for the hospital to attach great importance to the occurrence of catheter-related complications.

Objective:To analyze the learning curve of TiRobot-assisted lumbar pedicle screw fixation (LPSF) by cumulative sum (CUSUM) test method.Methods:The clinical data of 50 patients who underwent TiRobot-assisted LPSF from January 2020 to December 2022 in Beijing Friendship Hospital, Capital Medical University were retrospectively analyzed. CUSUM analysis and learning curve fitting were performed with robot usage time as the main indicator with the time for each step refined (robot registration time, path planning time and guide wire placement time), to select the best learning curve fitting model with the R2 value closest to 1. Using the turning point of the learning curve as the boundary, the learning curve was divided into two stages as learning stage and maturity stage, and then the observation indexes were compared between the two stages. Results:All 50 patients successfully completed the surgery without perioperative complications, with a total of 244 pedicle screws implanted. The total robot usage time and robot registration time showed a gradually decreasing trend with the increase of case number, and the learning curves were successfully fitted and reached their peaks at the seventeenth and thirteenth cases respectively. The entire learning process was divided into learning stage (17 cases) and maturity stage (33 cases) based on the turning point of the learning curve of total robot usage time. The path planning time and guide wire placement time did not show significant changes with the increase in the case number. The total robot usage time, robot registration time and the intraoperative blood loss in the learning stage were significantly higher than those in the maturity stage: (35.35 ± 1.58) min vs. (30.61 ± 0.43) min, (20.83 ± 1.56) min vs. (14.94 ± 0.29) min and 400 (150, 500) ml vs. 200 (110, 300) ml, the guide wire placement time of per screw was significantly lower than that in the maturity stage: 2.00 (1.83, 2.34) min/screw vs. 2.33 (2.13, 2.69) min/screw, and there were statistical differences ( P<0.05 or <0.01). There were no statistical difference in the path planning time, path planning time of per screw, guide wire placement time and the accuracy of screw placement between two stages ( P>0.05). Conclusions:TiRobot-assisted LPSF is a new technology with safety and effectiveness, and it has a relatively short learning curve. To achieve technological maturity, at least 17 surgeries are required with accumulated experience, and the robot registration is the main step of the learning process. After reaching maturity stage, the robot usage time is significantly shortened and intraoperative trauma is significantly reduced while the relatively high screw placement accuracy is ensured.