BACKGROUND:Knee osteoarthritis(KOA)is a common chronic inflammatory disease that causes damage to joint cartilage and surrounding tissues.Immune cells play an important role in the immune-inflammatory response in knee osteoarthritis,but the specific mechanisms involved are still not fully understood. OBJECTIVE:To evaluate the potential causal relationship between 731 immune cell phenotypes and the risk of knee osteoarthritis using Mendelian randomization. METHODS:Summary statistics of genome-wide association studies(GWAS)for 731 immune cell phenotypes(from GCST0001391 to GCST0002121)obtained from the GWAS catalog and GWAS data for knee osteoarthritis from the IEUGWAS database(ebi-a-GCST007090)were used.Inverse variance-weighted method,MR-Egger regression,weighted median method,weighted mode method,and simple mode method were employed to investigate the causal relationship between immune cells and knee osteoarthritis.Sensitivity analyses were conducted to assess the reliability of the Mendelian randomization results.Reverse Mendelian randomization analysis was also performed using the same methods. RESULTS AND CONCLUSION:The forward MR analysis indicated significant causal relationships(FDR<0.20)between knee osteoarthritis and four immune cell phenotypes,namely CD27 on CD24+CD27+in B cells(OR=1.026,P=0.000 26,Pfdr=0.18),CD33 on CD33dim HLA DR-in myeloid cells(OR=1.014,P=0.000 50,Pfdr=0.18),and CD45RA+CD28-CD8br%CD8br in Treg cells(OR=1.001,P=0.000 78,Pfdr=0.18),and PDL-1 on monocytes in mononuclear cells(OR=0.952,P=0.000 98,Pfdr=0.18).These immune cell phenotypes showed direct positive or negative causal associations with the risk of knee osteoarthritis.Reverse Mendelian randomization analysis revealed no significant causal relationships(FDR<0.20)between knee osteoarthritis as exposure and any of the 731 immune cell phenotypes.The results of sensitivity analysis show that the P-values of the Cochran's Q test and the MR-Egger regression method for bidirectional Mendelian randomization were both greater than 0.05,indicating that there is no significant heterogeneity and pleiotropy in the causal effect analysis between immune cell phenotypes and knee osteoarthritis.To conclude,there may be four potential causal relationships between immune cell phenotypes,such as CD27 on CD24+CD27+cells,CD33 on CD33dim HLA DR-cells,CD45RA+CD28-CD8br%CD8br cells,and PDL-1 on monocytes,and knee osteoarthritis.These findings provide valuable clues for studying the biological mechanisms of knee osteoarthritis and exploring early prevention and treatment strategies.They also offer new directions for the development of intervention drugs.

Background The positive rate of work-related musculoskeletal disorders (WMSDs) among coal mine workers remains high, which seriously affects the quality of life of the workers. Objective To estimate the prevalence of WMSDs among coal miners in Shanxi Province and analyze their influencing factors. Methods From May to December 2023, 2315 coal miners from a coal mine enterprise inShanxi Province were selected by convenience sampling, and the self-administered Basic Situation Survey Scale, Musculoskeletal Disorders Questionnaire, Effort-Reward Imbalance Questionnaire, and Pittsburgh Sleep Quality Scale were used to evaluate general demographic characteristics, work organization characteristics, living habits, sleep quality, occupational stress, and occurrence of WMSDs symptoms and the corresponding absences (sickness absence) in past 1 year. The positive rate and absenteeism rate of WMSDs were caculated, and Pearson's chi-square test was used for identify influencing factors of WMSDs, and finally a binary logistic regression method was used to further studying the factors. Results A total of 2577 questionnaires were distributed in this survey, and 2315 valid questionnaires were recovered, with an effective recovery rate of 89.9%. The positive rate of WMSDs symptoms was 48.7% (1127/2315), the absenteeism rate due to WMSDs was 22.6% (523/2315), and the waist (17.5%), neck (11.7%), and knee (9.0%) were the most common areas presenting WMSDs symptoms. The results of logistic regression showed that compared with ≤10 years of service, the risk of WMSDs was higher for those with > 20 years of service (OR=2.167, 95%CI: 1.419, 3.311). Compared with the daily working time of ≤8 h, the risk of WMSDs was higher for those >8 h daily working time (OR=1.463, 95%CI: 1.211, 1.767). A higher risk of WMSDs was reported in workers with moderate labor intensity (OR=1.247, 95%CI: 1.009, 1.542) or heavy labor intensity (OR=1.570, 95%CI: 1.215, 2.027) than those with light labor intensity. The higher the education level (OR _{high school and technical secondary school}=1.866, 95%CI: 1.435, 2.425; OR _{junior college/bachelor degree or above}=1.953, 95%CI: 1.445, 2.639), the higher the risk of WMSDs. The risk of WMSDs was higher in workers reporting smoking (OR=1.225, 95%CI: 1.021, 1.470) or alcohol consumption (OR=1.345, 95%CI: 1.122, 1.612). The risk of WMSDs in coal miners with high occupational stress (OR=1.229, 95%CI:1.030, 1.466) or those with sleep disorders (OR=3.616, 95%CI:2.824, 4.629) was higher than that in workers with low occupational stress or no sleep disorders respectively. Conclusion The positive rate of WMSDs among coal mine personnel in Shanxi Province is high, and education level, length of service, daily working hours, smoking, alcohol consumption, labor intensity, sleep disorders, and occupational stress are influencing factors for WMSDs.

ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

Purpose: This study assessed the performance of the ultrasound-guided attenuation parameter (UGAP) in diagnosing and grading hepatic steatosis in patients with metabolic dysfunctionassociated steatotic liver disease (MASLD). Magnetic resonance imaging proton density fat fraction (MRI-PDFF) served as the reference standard. Methods: Patients with hepatic steatosis were enrolled in this prospective study and underwent UGAP measurements. MRI-PDFF values of ≥5%, ≥15%, and ≥25% were used as references for the diagnosis of steatosis grades ≥S1, ≥S2, and S3, respectively. Spearman correlation coefficients and area under the receiver operating characteristic curves (AUCs) were calculated. Results: Between July 2023 and June 2024, the study included 88 patients (median age, 40 years; interquartile range [IQR], 36 to 46 years), of whom 54.5% (48/88) were men and 45.5% (40/88) were women. Steatosis grades exhibited the following distribution: 22.7% (20/88) had S0, 50.0% (44/88) had S1, 21.6% (19/88) had S2, and 5.7% (5/88) had S3. The success rate for UGAP measurements was 100%. The median UGAP value was 0.74 dB/cm/MHz (IQR, 0.65 to 0.82 dB/ cm/MHz), and UGAP values were positively correlated with MRI-PDFF (r=0.77, P<0.001). The AUCs of UGAP for the diagnoses of ≥S1, ≥S2, and S3 steatosis were 0.91, 0.90, and 0.88, respectively. In the subgroup analysis, 98.4% (60/61) of patients had valid controlled attenuation parameter (CAP) values. UGAP measurements were positively correlated with CAP values (r=0.65, P<0.001). Conclusion Using MRI-PDFF as the reference standard, UGAP demonstrates good diagnostic performance in the detection and grading of hepatic steatosis in patients with MASLD.

Purpose: This study assessed the performance of the ultrasound-guided attenuation parameter (UGAP) in diagnosing and grading hepatic steatosis in patients with metabolic dysfunctionassociated steatotic liver disease (MASLD). Magnetic resonance imaging proton density fat fraction (MRI-PDFF) served as the reference standard. Methods: Patients with hepatic steatosis were enrolled in this prospective study and underwent UGAP measurements. MRI-PDFF values of ≥5%, ≥15%, and ≥25% were used as references for the diagnosis of steatosis grades ≥S1, ≥S2, and S3, respectively. Spearman correlation coefficients and area under the receiver operating characteristic curves (AUCs) were calculated. Results: Between July 2023 and June 2024, the study included 88 patients (median age, 40 years; interquartile range [IQR], 36 to 46 years), of whom 54.5% (48/88) were men and 45.5% (40/88) were women. Steatosis grades exhibited the following distribution: 22.7% (20/88) had S0, 50.0% (44/88) had S1, 21.6% (19/88) had S2, and 5.7% (5/88) had S3. The success rate for UGAP measurements was 100%. The median UGAP value was 0.74 dB/cm/MHz (IQR, 0.65 to 0.82 dB/ cm/MHz), and UGAP values were positively correlated with MRI-PDFF (r=0.77, P<0.001). The AUCs of UGAP for the diagnoses of ≥S1, ≥S2, and S3 steatosis were 0.91, 0.90, and 0.88, respectively. In the subgroup analysis, 98.4% (60/61) of patients had valid controlled attenuation parameter (CAP) values. UGAP measurements were positively correlated with CAP values (r=0.65, P<0.001). Conclusion Using MRI-PDFF as the reference standard, UGAP demonstrates good diagnostic performance in the detection and grading of hepatic steatosis in patients with MASLD.

Purpose: This study assessed the performance of the ultrasound-guided attenuation parameter (UGAP) in diagnosing and grading hepatic steatosis in patients with metabolic dysfunctionassociated steatotic liver disease (MASLD). Magnetic resonance imaging proton density fat fraction (MRI-PDFF) served as the reference standard. Methods: Patients with hepatic steatosis were enrolled in this prospective study and underwent UGAP measurements. MRI-PDFF values of ≥5%, ≥15%, and ≥25% were used as references for the diagnosis of steatosis grades ≥S1, ≥S2, and S3, respectively. Spearman correlation coefficients and area under the receiver operating characteristic curves (AUCs) were calculated. Results: Between July 2023 and June 2024, the study included 88 patients (median age, 40 years; interquartile range [IQR], 36 to 46 years), of whom 54.5% (48/88) were men and 45.5% (40/88) were women. Steatosis grades exhibited the following distribution: 22.7% (20/88) had S0, 50.0% (44/88) had S1, 21.6% (19/88) had S2, and 5.7% (5/88) had S3. The success rate for UGAP measurements was 100%. The median UGAP value was 0.74 dB/cm/MHz (IQR, 0.65 to 0.82 dB/ cm/MHz), and UGAP values were positively correlated with MRI-PDFF (r=0.77, P<0.001). The AUCs of UGAP for the diagnoses of ≥S1, ≥S2, and S3 steatosis were 0.91, 0.90, and 0.88, respectively. In the subgroup analysis, 98.4% (60/61) of patients had valid controlled attenuation parameter (CAP) values. UGAP measurements were positively correlated with CAP values (r=0.65, P<0.001). Conclusion Using MRI-PDFF as the reference standard, UGAP demonstrates good diagnostic performance in the detection and grading of hepatic steatosis in patients with MASLD.

OBJECTIVE To investigate the effects and potential mechanism of paeoniflorin on oxidative stress of ulcerative colitis （UC） mice based on adenosine monophosphate-activated protein kinase （AMPK）/nuclear factor-erythroid 2-related factor 2 （Nrf2） pathway. METHODS Male BALB/c mice were randomly divided into control group， model group， inhibitor group （AMPK inhibitor Compound C 20 mg/kg）， paeoniflorin low-， medium- and high-dose groups （paeoniflorin 12.5， 25， 50 mg/kg）， high- dose of paeoniflorin+inhibitor group （paeoniflorin 50 mg/kg+Compound C 20 mg/kg）， with 8 mice in each group. Except for the control group， mice in all other groups were given 4% dextran sulfate sodium solution for 5 days to establish the UC model. Subsequently， mice in each drug group were given the corresponding drug solution intragastrically or intraperitoneally， once a day， for 7 consecutive days. The changes in body weight of mice were recorded during the experiment. Twenty-four hours after the last administration， colon length， malondialdehyde （MDA） content， and activities of superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px） in colon tissues were measured； histopathological morphology of colon tissues， tight junctions between intestinal epithelial cells， and histopathological scoring were all observed and evaluated； the mRNA expressions of AMPK and Nrf2， as well as the protein expressions of heme oxygenase-1（HO-1）， occludin and claudin-1， were all determined in colon tissue. RESULTS Compared with model group， paeoniflorin groups exhibited recovery from pathological changes such as inflammatory cell infiltration and crypt damage in the colon tissue， as well as improved tight junction damage between intestinal epithelial cells. Additionally， significant increases or upregulations were observed in body weight， colon length， activities of SOD and GSH-Px， phosphorylation level of AMPK， and protein expression of Nrf2， HO-1， occludin， claudin-1， and mRNA expressions of AMPK and Nrf2； concurrently， MDA content and histopathological scores were significantly reduced （P＜ 0.05 or P＜0.01）. In contrast， the inhibitor group showed comparable （P＞0.05） or worse （P＜0.05 or P＜0.01） indicators compared to the model group. Conversely， the addition of AMPK inhibitor could significantly reverse the improvement of high- dose paconiflorin （P＜0.01）. CONCLUSIONS Paeoniflorin can repair intestinal epithelial cell damage in mice， improve tight junctions between epithelial cells， upregulate the expression of related proteins， and promote the expression and secretion of antioxidant-promoting molecules， thereby ameliorating UC； its mechanism may be associated with activating AMPK/Nrf2 antioxidant pathway.

ObjectiveTo investigate the mechanism of topical treatment of allergic contact dermatitis （ACD） mice with Portulacae Herba based on the nuclear factor E₂-related factor 2 （Nrf2）/heme oxygenase-1 （HO-1）/nuclear factor-κB （NF-κB） signaling pathway. MethodsA total of 70 6-week-old specific pathogen free （SPF） female Kunming mice were adaptively fed for 1 week and randomly divided into blank group， model group， compound dexamethasone acetate cream group （2.075×10^-2 g·g^-1）， blank matrix cream group， low-dose Portulacae Herba cream group （0.1 g·g^-1）， high-dose Portulacae Herba cream group （0.2 g·g^-1）， and Portulacae Herba + inhibitor group （0.2 g·g^-1 + 30 mg·kg^-1 ML385）， with 10 mice in each group. One day before the experiment， the mice were shaved on the neck and back. Except for the blank group， the mice in the other groups were treated with 2，4-dinitrochlorobenzene （DNCB） to establish an ACD model. After respective administration， the skin lesion of the mice was scored， and the histopathological changes of the skin were stained with hematoxylin-eosin （HE）. Enzyme-linked immunosorbent assay （ELISA） was used to detect the levels of interleukin-6 （IL-6）， interleukin-1β （IL-1β）， reactive oxygen species （ROS）， superoxide dismutase （SOD） activity， and malondialdehyde （MDA） in serum of mice. The expression of Nrf2/HO-1/NF-κB signaling pathway-related proteins in mouse skin tissue was detected by immunohistochemistry （IHC）， Western blot， and real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. ResultsCompared with the blank group， the mice in the model group had an increased skin lesion score （P<0.01）， severe pathological damage to skin tissue， increased content of IL-1β， IL-6， ROS， and MDA in their serum （P<0.01）， and decreased content of SOD （P<0.01）. In addition， the mRNA and protein expression levels of Nrf2， HO-1， and nuclear factor-κB inhibitor α （IκBα） in skin tissue were up-regulated （P<0.01）， while the protein expression levels of phosphorylated （p）-IκBα and p-NF-κB p65 and the mRNA expression of NF-κB p65 were down-regulated （P<0.01）. Compared with the model group and the blank matrix cream group， the mice treated with Portulacae Herba had a decreased skin lesion score （P<0.01）， reduced pathological damage to skin tissue， decreased content of IL-1β， IL-6， ROS， and MDA in their serum （P<0.01）， and increased content of SOD （P<0.01）. Additionally， the mRNA and protein expression levels of Nrf2， HO-1， and IκBα in skin tissue were down-regulated （P<0.05，P<0.01）， and the protein expression levels of p-IκBα and p-NF-κB p65 and the mRNA expression of NF-κB p65 were up-regulated （P<0.05，P<0.01）. Compared with the Portulacae Herba + inhibitor group， the high-dose Portulacae Herba cream group had a decreased skin lesion score （P<0.01）， alleviated pathological damage to skin tissue， decreased content of IL-1β， IL-6， ROS， and MDA in the serum of mice （P<0.05，P<0.01）， and increased content of SOD （P<0.01）. The protein expression levels of Nrf2， HO-1， and IκBα and the mRNA expression of Nrf2 and HO-1 in skin tissue were up-regulated （P<0.05，P<0.01）， and the protein expression levels of p-IκBα and p-NF-κB p65 and the mRNA expression of NF-κB p65 were down-regulated （P<0.05）. ConclusionPortulacae Herba can improve DNCB-induced ACD skin damage in mice by regulating the Nrf2/HO-1/NF-κB signaling pathway.