BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.

BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.

OBJECTIVE To explore the mechanism of Chaiqi yigan granules （CQYG） against liver cancer through the ferroptosis pathway. METHODS Network pharmacology combined with ferroptosis-related database was used to screen key targets and main effective components of CQYG against liver cancer via regulating ferroptosis； molecular docking technology was employed to analyze the binding ability of main active components to key targets. Human liver Huh-7 cells were divided into blank serum control （CON） group， CQYG drug-containing serum （CQYGKL） group， ferroptosis inducer （RSL3） group， mammalian target of rapamycin complex 1 （mTORC1） inhibitor （RMC-5552） group， mTORC1 agonist （CCT007093） group， and CCT007093+CQYGKL group. The levels of Fe 2+ ， malondialdehyde （MDA）， and glutathione （GSH） in the cells were detected in the former three groups； mRNA expressions of mammalian target of rapamycin （mTOR）， sterol regulatory element-binding protein 1 （SREBP1）， and stearoyl-CoA desaturase 1 （SCD1）， protein expressions of SREBP1 and SCD1 as well as phosphorylation levels of mTOR and ribosomal S6 kinase （S6K） proteins were detected in all groups. RESULTS Key targets of CQYG for anti-liver cancer through the ferroptosis pathway were mTOR， SREBP1， SCD1，etc. The main active components included quercetin， tanshinone Ⅱ A ， baicalein， etc. The binding energies of main active components to key targets were all less than －5 kJ/mol. Compared with CON group， the levels of Fe 2+ and MDA in the cells in CQYGKL group and RSL3 group were significantly increased， while the levels of GSH were significantly decreased （ P ＜0.05）. mRNA expressions of mTOR， SREBP1 and SCD1， protein expressions of SREBP1 and SCD1， as well as the phosphorylation levels of mTOR and S6K proteins were significantly decreased in the CQYGKL group， RSL3 group， and RMC-5552 group， whereas all the above indicators were significantly increased in the CCT007093 group （ P ＜0.05）. Compared with CCT007093 group， the changes in all the above indicators were significantly suppressed in the CCT007093+CQYGKL group （ P ＜0.05）. CONCLUSIONS CQYG may induce ferroptosis by inhibiting mTORC1/SREBP1/SCD1 axis， thereby exerting anti-liver cancer effects.

Objective To propose a novel mechanical method and index to in-vivo characterize the health status of cancellous bone during the percutaneous kyphoplasty(PKP),and validate its feasibility and consistency.Methods According to the theory of elasticity,the expression and physical significance of the mechanical index K were given.Then using clinical images of the lumbar spine L4,three-dimensional finite element simulations were conducted to verify the validity of the theoretical results,as well as the consistency of the methodology and the indexes were verified for studies of different balloon shapes and puncture routes.Results The internal pressure of the balloon linearly varied with the injected fluid volume.The mechanical index K was closely related to the bone shear modulus and could well reflect the health status of cancellous bones.The balloon shape had a trivial influence on the Kresults,and the relative difference between the cylindrical and ellipsoidal shapes was less than 2％.The influence of surgical access route on the K results was also very small,and the relative difference between the routes by vertebral pedicle and by lateral margin of vertebral pedicle was less than 0.5％.Conclusions The in-vivo mechanical method and the mechanical index K can characterize the bone health of patients with good consistency.This study has a great significance for providing guidelines of the optimization of PKP operation plan and postoperative rehabilitation,collecting in vivo data of bone mechanical properties,and improving the diagnosis and treatment of osteoporosis in clinic.

Objective:To explore the occurrence and clinical characteristics of nephrogenic systemic fibrosis (NSF) induced by gadolinium-based contrast agents (GBCA).Methods:CNKI, Wanfang, VIP and PubMed databases were searched (as of October 28, 2024) and case reports on GBCA-related NSF were collected; the following information was extracted, including the publication year of the literature, country, patient gender, age, basic kidney diseases and renal replacement therapy, variety of GBCA used, exposure frequency, time of occurrence or diagnosis of NSF, clinical manifestations, pathological examination, main intervention measures and outcomes. The data were analyzed by descriptive statistics.Results:A total of 45 case reports were collected, involving 97 patients. The literature were reported mainly from the United States and published mainly in 2006 and 2007. Number of the relevant literature decreased significantly after 2008, but there were still new cases reports in China in the following years (for example, in 2023). Among the 97 patients, 53 (54.6%) were male and 44 (45.4%) were female; the age ranged from 9 to 83 years with a median age of 53 years. One patient was with severe malnutrition, while the other 96 had severe basic kidney diseases, including chronic kidney disease in 85 (88.5%) patients and acute kidney injury in 11 (11.5%) patients. Variety of GBCA exposed was described in 76 patients, including gadodiamide in 67 (88.2%) patients. Exposure frequency of GBCA before NSF occurrence was described in 88 patients, 48 (54.5%) of which were exposed only once and 23 (26.1%) were exposed twice. Time from the first GBCA exposure to the occurrence of NSF was described in 92 patients, with the shortest time of 2 days and the longest time of more than 10 years; 70.7% (65/92) occurred within 3 months after GBCA exposure. All patients had typical skin symptoms of NSF, which were confirmed by pathological examination. Among them, 43 (44.3%) had joint disorders, 9 patients had eye involvement, a few patients had cardiac fibrosis, respiratory failure, metabolic acidosis, rhabdomyolysis, muscle necrosis, etc. Follow-up information was described in 82 patients with a range of 4 months to 11 years. Among them, 21 patients (25.6%) died, mainly due to the basic kidney diseases and complications; 11 (13.4%) were severely disabled; 7 (8.5%) were mildly disabled or slowly deteriorated; 43 (52.4%) had stable disease or slightly improved condition.Conclusion:NSF caused by GBCA mainly occurs in patients with severe basic renal diseases, mostly caused by gadodiamide. Severe skin damage is often accompanied by joint involvement or even disability, and the overall prognosis is poor.

Carbon dioxide(CO2),a colorless,odorless,low-density negative contrast agent with no nephrotoxicity or allergic reactions,has seen increasingly widespread application in the field of vascular imaging in recent years,particularly in patients with iodine allergy or renal insufficiency.When combined with digital subtraction angiography,CO2 angiography has demonstrated high-quality imaging in various arterial and venous sites such as the abdominal aorta,renal arteries,iliac arteries,lower limb arteries,and inferior vena cava.It has also shown safety and efficacy in clinical scenarios such as peripheral arterial disease,dialysis access evaluation,and transjugular intrahepatic portosystemic shunt procedures.This review systematically summarizes domestic and international research progress on CO2 angiography,outlines its physicochemical properties,injection dosages and parameters,clinical indications,and imaging characteristics,and compares its image quality with that of iodine-based contrast agents.Common complications,their mechanisms,and preventive measures are also discussed.Although the image quality of CO2 is slightly inferior to that of iodine agents,it remains sufficient for most diagnostic and therapeutic needs,with a low overall incidence of mainly mild and transient adverse effects.With the development of automated injection systems and digital variance angiography technology,CO2 imaging quality is expected to continue improving,and its application scope is likely to expand further.Future efforts should focus on strengthening multicenter clinical research and establishing standardized operational protocols to promote the broader adoption and regulated use of this technology.

Objective:To analyze the awareness of HCV infection status and willingness for HCV-RNA testing among hepatitis C cases in four provinces in China and to provide a reference for adjusting HCV prevention and control strategies.Methods:From September 2021 to September 2022, a cross-sectional survey was conducted using stratified random cluster sampling in four provinces (Jiangsu, Henan, Hubei, and Yunnan) in China, with an estimated sample size of 6 468 participants. The questionnaire included sociodemographic information, HCV infection awareness, willingness for HCV-RNA testing, and history of high-risk behaviors from the survey participants. Logistic regression models were used to analyze the factors associated with HCV infection awareness and willingness for HCV-RNA testing among hepatitis C cases. Statistical analysis was performed using R 4.1.3 software.Results:A total of 10 563 hepatitis C cases were surveyed. The awareness rate of HCV infection was 86.74% (9 162/10 563), and the willingness rate for HCV-RNA testing was 85.21% (9 001/10 563). Multivariate logistic regression models analysis showed that the awareness rate of HCV infection was lower among individuals aged ≥60 years, urban residents (with New Rural Cooperative Medical Insurance ), those without a history of blood transfusion, those without a history of paid blood donation, those without a history of injection drug use, and those without a family member with hepatitis C case.The awareness rate was higher among individuals with high or technical secondary school education, college education or above, and those married with a spouse (all P<0.05). In terms of willingness for HCV-RNA testing, it was lower among females, individuals aged ≥60 years, and those without a history of blood transfusion, paid blood donation, or injection drug use. The willingness was higher among farmers or migrant workers, employees of enterprises or institutions, and those in other occupations (all P<0.05). Conclusions:There was room for improvement in the awareness proportion of HCV infection and willingness for HCV-RNA testing among hepatitis C cases in the four provinces of China. More convenient policies and measures should be provided to increase the awareness rate of HCV infection and the willingness to undergo HCV-RNA testing in this population.

Objective:To optimize the image quality of PET/CT following 90Y-selective internal radiation therapy ( 90Y-SIRT) using block-sequential regularized expectation maximization (BSREM) reconstruction algorithm, and to evaluate its impact of different β values on image quality and quantitative analysis. Methods:A retrospective study was conducted on 8 male patients with hepatic tumors (age: 62(52, 71) years) treated at Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua Medicine Tsinghua University, between June 2024 and January 2025. All patients were treated with 90Y resin microspheres (2.6(0.9, 3.6)GBq) and underwent post-treatment 90Y PET/CT liver imaging. Imaging data were reconstructed using BSREM with different noise penalty weighting factors ( β values: 0, 300, 1000, 1500, 2500, 3500, 4000, 6000, 8000, 10000). Visual assessment was independently performed by two nuclear medicine physicians, using a 4-point scale (1=worst, 4=best). The mean score was considered as the final score. The consistency of the 2 reviewers was calculated and analyzed by Kappa test. Visual scores of different β value groups were compared by Friedman test. The β value demonstrating highest mean score and optimal consistency was selected as the optimal. Quantitative analysis was performed using MIM software to calculate the maximum absorbed dose ( Dmax) and the mean absorbed dose ( Dmean) for tumor, normal liver, and whole liver regions, and the CV was used to evaluate the impact of β values. Results:The visual assessment consistency of reviewers in 3 β value groups (0, 3500, 6000) were the highest (7/8) (all kappa=0.88, all P<0.05). Visual scores of the 10 β value groups were significantly different ( χ2=28.74, P<0.001), and the visual scores of 2 β value groups (3500, 4000) were the highest, both of which were 4.0(4.0, 4.0). Overall, visual assessment identified β=3500 as the optimal. Quantitative analysis revealed that, (1) Dmax in all regions (tumor, normal liver, whole liver) decreased with the increasing β values, stabilizing when β>1000 ( CV 56%-67%); (2) Dmean remained stable across different β values ( CV 0.04%-5.00%). Conclusions:In BSREM reconstruction, β=3500 is the optimal parameter for improving 90Y-PET image quality. β values significantly affect Dmax (stabilizing at β > 1000), but have no significant impact on Dmean, suggesting that reconstruction parameters primarily influence dose distribution morphology rather than average dose assessments.

AIM:To investigate the impact of Kir2.1 channels on abnormal spontaneous pacemaker activities induced by hypokalemia and to elucidate the underlying mechanisms.METHODS:Human induced pluripotent stem cell-derived cardiomyocytes(hiPSC-CMs)were transfected with lentiviral particles containing sequences for human Kir2.1,the Kir2.1-E224G mutant,or Kir4.1.Patch clamp techniques were employed to examine the effects of low extracellular potassium concentration([K+]e)of 1 mmol/L on the resting membrane potentials and whole-cell currents of the cells in each group,assessed via both current and voltage clamp modes.RESULTS:Under conditions of 1 mmol/L[K+]e,cur-rent clamp data revealed that hiPSC-CMs overexpressing Kir2.1 channels exhibited both hyperpolarized and depolarized resting membrane potentials,with the depolarized state triggering abnormal pacemaker activities.In contrast,cells overex-pressing the Kir2.1-E224G mutant or Kir4.1 channels displayed only hyperpolarized resting membrane potentials.Voltage clamp analysis indicated that hiPSC-CMs overexpressing Kir2.1 channels produced"N"-shaped whole-cell currents,whereas cells expressing the Kir2.1-E224G mutant or Kir4.1 exhibited typical K+currents.CONCLUSION:Kir2.1 channels play a crucial role in mediating hypokalemia-induced abnormal spontaneous pacemaker activities in human car-diomyocytes through their inward rectification properties.

Objective:To determine the best scoring system for assessing the severity of perioperative aortic dissection.Methods:All data were obtained from the Medical Information Mart for Intensive Care-Ⅳ(MIMIC-Ⅳ) database in the United States. The predictive value of the Acute Physiology Score Ⅲ(APS Ⅲ), Oxford Acute Severity of Illness Score (OASIS), Sequential Organ Failure Assessment (SOFA), Simplified Acute Physiology Score Ⅱ(SAPS Ⅱ), and Charlson Comorbidity Index (CCI) scoring systems were evaluated using the receiver operating characteristic ( ROC) curve. The area under the curve ( AUC) was used to determine the best predictive score, and the ideal cutoff value of the score was calculated based on the Youden index. Patients were divided into high and low groups according to the cutoff value. The Kaplan- Meier curve was used to show the impact on the survival rate of patients with aortic dissection. Results:ROC curve analysis showed that APS Ⅲ( AUC: 0.803, 95% CI: 0.721-0.885) was superior to SAPS Ⅱ( AUC: 0.767, 95% CI: 0.654-0.880), OASIS( AUC: 0.760, 95% CI: 0.635-0.885), SOFA( AUC: 0.753, 95% CI: 0.649-0.857), and CCI( AUC: 0.670, 95% CI: 0.524-0.817) in assessing in-hospital mortality. Based on the ROC curve and the Youden index calculation, the ideal cutoff value of the APS Ⅲ score was 57.5. Kaplan- Meier survival analysis showed that patients in the high group of APS Ⅲ had a shorter 28-day survival time. Patients in the high group of APS Ⅲ had a higher incidence of postoperative complications, and correlation analysis showed that patients in the high group of APS Ⅲ had a longer hospital stay. Conclusion:The APS Ⅲ scoring system is more valuable in predicting the 28-day mortality and prognosis of patients with aortic dissection.