[Objective] To compare next generation sequencing (NGS) library construction technology between probe hybridization capture and amplicon methods, and analyze the influencing factors of HLA genotyping resolution level and its prospects in clinical applications. [Methods] A total of 207 clinical samples with known typing results and samples from the proficiency testing plan were selected. The conformity rate of HLA genotyping results, allele coverage and typing data analysis indicators were confirmed, and the effects of two library construction methods on the level of HLA genotyping discrimination were compared. [Results] The concordance rate of 207 samples with the feedback results of PT or prior well-characterized HLA genotypes was 100%. Among them, 91 samples were captured using hybridization probe capture method. Compared with the original amplicon method, the hybridization probe capture method can distinguish the alleles of DRB1 and DPB1 that cannot be determined in 13 samples. The allelic imbalance of DRB1, DPA1, and DQB1 loci in 6 samples was resolved. Three samples were found to have missed detection of alleles at the DQA1 and DQB1 loci. [Conclusion] The performance indicators of hybridization probe capture and amplicon performance confirmation meet the requirements of clinical detection of HLA genotyping, which provides an experimental method and basis for clinical application.

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.

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 establish a linkage prediction model for human leukocyte antigen (HLA) DPA1-DPB1 and validate it by using clinical data and follow-up data from unrelated allogeneic hematopoietic stem cell transplantation donors and recipients, and to explore the clinical application value of the prediction model in transplantation prognosis.Methods:This is a retrospective study. Leveraging the artificial neural network algorithm of NetMHCⅡpan and the DPA1-DPB1 haplotype linkage database of the Chinese population established in our previous research, and incorporating the amino acid FASTA data of DPA1-DPB1 of all known sequences newly published by the Latest International Immunogenetics/Human Leukocyte Antigens, 47 DPA1-DPB1 linkage models were established. Employing next-generation sequencing technology based on the hybridization capture library construction method, HLA genotyping tests for HLA-A, -B, -C, DRB1, DQB1, DQA1, DRB3/4/5, DPB1, and DPA1 (9 loci) were performed on 250 donor-recipients pairs who underwent unrelated-donor hematopoietic stem cell transplantation in the Department of Hematology of the First Affiliated Hospital of Soochow University between January 2016 and September 2021. HLA typing data and clinical information of transplant donors and recipients were retrospectively analyzed to assess and predict the impact of permissive and non-permissive linkage mismatches of DPA1-DPB1 on transplantation prognosis. The Kaplan-Meier method with the log-rank test was applied to compare the survival curves of overall survival (OS) rates between different groups. Additionally, a competing risks model was utilized to compare the cumulative incidence of grade Ⅱ-Ⅳ acute graft-versus-host disease and non-relapse mortality (NRM) across groups. The area under the receiver operating characteristic curve was employed to compare the predictive performance of the established prediction model with that of the T-cell epitope (TCE) model.Results:According to the different hydrophilic and hydrophobic properties of amino acids, the DPA1-DPB1 linkage model is categorized into types Ⅰ-Ⅳ: type I consists of 6 hydrophobic types at P1-P8 plus hydrophilic type at P9; type Ⅱ includes 17 hydrophobic types; type Ⅲ comprises 9 amphiphilic types; and type Ⅳ consists of 15 hydrophilic types. According to the prediction model, DPA1-matched and DPB1-mismatched donor-recipient cases were classed into P1-matched or P1-mismatched groups. Compared with fully matched DPA1 and DPB1 cases, P1-mismatched patients had a 2-year OS rate of 75% (12/16) versus 96.2%(25/26) (χ2=4.13, P=0.04), and a NRM rate of 4/16 versus 0 (χ2=7.05, P<0.01). However, there was no statistically significant difference in the 2-year OS and NRM rates compared to DPA1 and DPB1 cases ( P>0.05). The prediction model established in this study demonstrated a larger area under the receiver operating characteristic curve for predicting the 2-year OS rate compared with the DPB1 TCE model ( Z=0.71, P=0.48). In donor-recipient cases where both DPA1 and DPB1 were mismatched, the 2-year OS rates decreased and the NRM increased in both P1-matched and P1-mismatched cases compared with fully matched DPA1 and DPB1. Moreover, P1-mismatched patients had a worse prognosis compared to P1-matched patients. Conclusion:The DPA1-DPB1 linkage prediction model established based on high-throughput next-generation sequencing technology can be used to predict the impact of HLA-DP mismatches on OS and NRM in transplantation, and the prediction performance is superior to the TCE model.

Objective To investigate the underlying mechanism of metformin's protective effect on articular cartilage in rats afflicted with osteoarthritis.Methods Thirty male SD rats were randomly divided into three groups(n=10 per group)to establish a rat model of knee osteoarthritis.The metformin group received metformin via gavage[200 mg/(kg·d)],while the control and model groups received saline as a control.After 4 weeks,morphological staining was used to observe articular cartilage morphology,and immunohistochemical staining,immunofluores-cence staining,and Western blot were employed to detect the expression of factors related to the SIRT1/p53 signaling pathway,inflammation,and apoptosis.Results Compared to the model group,the metformin group exhibited significantly reduced cartilage structural damage,characterized by a smoother cartilage surface,increased chondrocyte population,and enhanced proteoglycan content.Immunohistochemical staining,immunofluorescence staining,and Western blot analysis revealed significantly higher expression levels of SOX9,Aggrecan,Bcl-2,and SIRT1 proteins in the metformin-treated cartilage tissue compared to the model group.Conversely,lower expression levels of IL-6 TNF-α BAX Caspase-9 and p53 proteins were observed in the metformin group compared to the model group.TUNEL staining results demonstrated a significant reduction in apoptotic chondrocytes within the metformin-treated group when compared with the model group.Conclusion Metformin exerts a protective effect on articular cartilage in SD rat models of osteoarthritis by activating the SIRT1/p53 signaling pathway,leading to decreased chondrocyte apoptosis and inhibition of extracellular matrix degradation.

Objective:The incidence of early-onset colorectal cancer (EOCRC) is increasing globally; however, the molecular characteristics and prognosis of sporadic EOCRC are unclear. In this systematic review and meta-analysis, we aimed to investigate the incidence of gene mutations and their association with cancer survival in sporadic EOCRC, focusing on six common gene mutations ( TP53, BRAF, KRAS, NRAS, PTEN, and APC). Methods:Ovid Embase and Ovid Medline electronic databases were searched for studies involving patients with sporadic EOCRC (i.e., diagnosed with colorectal cancer before the age of 50 years and with no evidence of hereditary syndromes predisposing to colorectal cancer). The included articles were evaluated using quality assessment tools. Meta-analysis was performed using random-effects and fixed-effects models. Cochran's Q statistic and the I2 index were used to assess heterogeneity. The incidence of the six common gene mutations listed above in sporadic EOCRC and their association with cancer survival were evaluated.Results:(1) Incidence of specific gene mutations in sporadic EOCRC. A total of 34 articles were included in this meta-analysis. The incidence of APC gene mutation was 36% (from 13 articles, 95%CI: 19%-55%, P=0.043); of KRAS gene mutation 30% (from 26 articles, 95%CI: 24%-35%, P=0.190); of BRAF gene mutation 7% (from 18 articles, 95%CI: 5%-11%, P=0.422); of NRAS gene mutation 4% (from five articles, 95%CI: 3%-5%, P=0.586); of PTEN gene mutation 6% (from six articles, 95%CI: 4%-10%, P=0.968); and of TP53 gene mutation 59% (from 13 articles, 95%CI: 49%-68%, P=0.164). (2) Association between gene mutations and survival in sporadic EOCRC . A total of six articles were included in this meta-analysis. Compared with wild-type BRAF, mutant BRAF was significantly associated with increased overall mortality risk in patients with EOCRC (pooled HR=2.85, 95%CI: 1.45-5.60, P=0.002). Subgroup analysis showed that the incidence of BRAF gene mutation was higher in Eastern than in Western countries, whereas the incidence of TP53, KRAS, NRAS, and APC gene mutations was lower. There was no significant difference in the incidence of PTEN gene mutation between different regions. Conclusion:Compared with colorectal cancer occurring in the general population, the incidence of APC and KRAS mutations is lower in EOCRC, whereas the incidence of TP53 mutation remains consistent. BRAF mutation is associated with increased overall mortality risk in patients with EOCRC.

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.

Objective:The incidence of early-onset colorectal cancer (EOCRC) is increasing globally; however, the molecular characteristics and prognosis of sporadic EOCRC are unclear. In this systematic review and meta-analysis, we aimed to investigate the incidence of gene mutations and their association with cancer survival in sporadic EOCRC, focusing on six common gene mutations ( TP53, BRAF, KRAS, NRAS, PTEN, and APC). Methods:Ovid Embase and Ovid Medline electronic databases were searched for studies involving patients with sporadic EOCRC (i.e., diagnosed with colorectal cancer before the age of 50 years and with no evidence of hereditary syndromes predisposing to colorectal cancer). The included articles were evaluated using quality assessment tools. Meta-analysis was performed using random-effects and fixed-effects models. Cochran's Q statistic and the I2 index were used to assess heterogeneity. The incidence of the six common gene mutations listed above in sporadic EOCRC and their association with cancer survival were evaluated.Results:(1) Incidence of specific gene mutations in sporadic EOCRC. A total of 34 articles were included in this meta-analysis. The incidence of APC gene mutation was 36% (from 13 articles, 95%CI: 19%-55%, P=0.043); of KRAS gene mutation 30% (from 26 articles, 95%CI: 24%-35%, P=0.190); of BRAF gene mutation 7% (from 18 articles, 95%CI: 5%-11%, P=0.422); of NRAS gene mutation 4% (from five articles, 95%CI: 3%-5%, P=0.586); of PTEN gene mutation 6% (from six articles, 95%CI: 4%-10%, P=0.968); and of TP53 gene mutation 59% (from 13 articles, 95%CI: 49%-68%, P=0.164). (2) Association between gene mutations and survival in sporadic EOCRC . A total of six articles were included in this meta-analysis. Compared with wild-type BRAF, mutant BRAF was significantly associated with increased overall mortality risk in patients with EOCRC (pooled HR=2.85, 95%CI: 1.45-5.60, P=0.002). Subgroup analysis showed that the incidence of BRAF gene mutation was higher in Eastern than in Western countries, whereas the incidence of TP53, KRAS, NRAS, and APC gene mutations was lower. There was no significant difference in the incidence of PTEN gene mutation between different regions. Conclusion:Compared with colorectal cancer occurring in the general population, the incidence of APC and KRAS mutations is lower in EOCRC, whereas the incidence of TP53 mutation remains consistent. BRAF mutation is associated with increased overall mortality risk in patients with EOCRC.