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.

Biomolecular condensates are formed through phase separation of biomacromolecules such as proteins and RNAs. These condensates exhibit liquid-like properties that can futher transition into more stable material states. They form complex internal structures via multivalent weak interactions, enabling precise spatiotemporal regulations. However, the use of inconsistent and non-standardized terminology has become increasingly problematic, hindering academic exchange and the dissemination of scientific knowledge. Therefore, it is necessary to discuss the terminology related to biomolecular condensates in order to clarify concepts, promote interdisciplinary cooperation, enhance research efficiency, and support the healthy development of this field.

ObjectiveHepatocyte nuclear factor 4-alpha (HNF4A) is a critical transcription factor in the liver and pancreas. Dysfunctions of HNF4A lead to maturity onset diabetes of the young 1 (MODY1). Notably, MODY1 patients with HNF4A pathogenic mutations exhibit decreased responses to arginine and reduced plasma triglyceride levels, but the mechanisms remain unclear. This study aims to investigate the potential target genes transcriptionally regulated by HNF4A and explore its role in these metabolic pathways. MethodsA stable 293T cell line expressing the HNF1A reporter was overexpressed with HNF4A. RNA sequencing (RNA-seq) was performed to analyze transcriptional differences. Transcription factor binding site prediction was then conducted to identify HNF4A binding motifs in the promoter regions of relevant target genes. ResultsRNA-seq results revealed a significant upregulation of transmembrane 4 L six family member 5 (TM4SF5) mRNA in HNF4A-overexpressing cells. Transcription factor binding predictions suggested the presence of five potential HNF4A binding motifs in the TM4SF5 promoter. Finally, we confirmed that the DR1 site in the -57 to -48 region of the TM4SF5 promoter is the key binding motif for HNF4A. ConclusionThis study identified TM4SF5 as a target gene of HNF4A and determined the key binding motif involved in its regulation. Given the role of TM4SF5 as an arginine sensor in mTOR signaling activation and triglyceride secretion, which closely aligns with phenotypes observed in MODY1 patients, our findings provide novel insights into the possible mechanisms by which HNF4A regulates triglyceride secretion in the liver and arginine-stimulated insulin secretion in the pancreas.

Objective: To explore the relationship of physical activity (PA) and sedentary behavior (SB) with cardiorespiratory fitness (CRF) among middle schoold students in Tibet, so as to provide empirical references for improving the cardiorespiratory fitness and health levels of adolescents in Tibet. Methods: From August to December 2020, 1 225 junior and senior high school students were selected from 2 middle schools in Lhasa, Tibet Autonomous Region, using the stratified cluster random sampling method. Triaxial accelerometers were used to evaluate PA and SB behaviors, and the 20 meter shuttle run was employed to assess CRF among the middle school students. Isochronous substitution modeling was used to analyze the associations of SB, low intensity physical activity (LPA), and moderate vigorous physical activity (MVPA) with CRF, and the saturation threshold effect in the dose response relationship between MVPA and CRF was analyzed through restricted cubic spline and two stage linear regression. Results: After adjusting for covariates such as gender, body mass index and sleep quality score, isotemporal substitution analysis showed that among junior high school students aged 13-15, replacing 30 minutes of SB ( B =1.73) or LPA ( B =2.38) with MVPA were positively associated with CRF (both P <0.05). Among senior high school students aged 16-18, replacing SB ( B =0.99) or LPA ( B =1.38) with MVPA were also positively associated with CRF (both P <0.05). Restricted cubic spline and two piecewise linear regression analyses indicated that only middle school girls aged 13-18 exhibited a saturation threshold effect between MVPA and CRF (logarithmic likelihood ratio test=0.03), with the optimal CRF improvement observed at 60 minutes of MVPA per day ( B=0.13, P ＜ 0.01). Conclusions Reducing SB and LPA while increasing MVPA can improve CRF in Tibetan middle school students. To maximize CRF improvement, middle school girls should engage in at least 60 minutes of MVPA daily.

Aim To compare the pharmacokinetics of pemirolast potassium tablets in healthy subjects in Chi-na under single fasting and postprandial conditions,and to evaluate the bioequivalence of the test prepara-tion(T)and the reference preparation(R).Methods A randomized,open-ended,single-dose,two-cycle,double-cross bioequivalence trial design was adopted,and 26 and 30 subjects were enrolled in the fasting group and the postprandial group,respectively,and 10 mg of the test preparation and the reference preparation were taken in the fasting or postprandial state each cy-cle,and venous blood was collected at the designed time points before and after the administration cycle.The concentration of pemirolast potassium in plasma was determined by LC-MS/MS method,and the phar-macokinetic parameters were calculated with PhoenixTM WinNonlin ?(8.3)software,and the bioequivalence analysis of the two preparations was performed.Re-sults The t1/2 of the test preparation and the reference preparation was(4.44±0.91)h and(4.49±0.93)h,respectively;the median tmax was(1.96±1.29)h and(2.18±1.25)h,respectively;the Cmax was(867.12±205.56)μg·L-1 and(863.35±172.03)μg·L-1,respectively;the AUC0-t was(5 513.23±1463.67)h·μg·L-1 and(5 661.32±1 628.65)h·μg·L-1,respectively;AUC0_∞ was(5 699.81±1477.68)h·μg·L-1 and(5 849.44±1 644.75)h·μg·L-1,respectively.The statistical results of the 90％confidence intervals of the main pharmacokinetic parameters Cmax,AUC0-t,and AUC0-∞ was 92.49％～107.53％,94.71％～100.67％and 95.28％～100.27％,respectively,all of which were within the range of 80.00％～125.00％,and the safety of the tested preparation and the reference preparation was good when taken orally on an empty stomach.The t1/2 of single oral administration after prandial administra-tion of the tested preparation and the reference prepara-tion was(4.46±0.78)and(4.51±0.84)h,respec-tively;the median tmax was(3.08±1.36)h and(3.28±1.28)h,respectively;the Cmax was(683.83±111.87)μg·L-1 and(689.77±110.24)μg·L-1,respectively;the AUC0-t was(5 695.99±1566.05)h·μg·L-1 and(5 773.60±1 551.04)h·μg·L-1,respectively;the AUC0-∞ was(5 914.06±1 551.86)h·μg·L-1 and(5 967.30±1552.89)h·μg·L-1,respectively.The 90％confi-dence interval of Cmax,AUC0-t,and AUC0-∞ was 93.56％～104.69％,96.43％～100.83％,and 97.29％～101.14％,respectively,which was in the range of 80.00％～125.00％,and the safety of the tested preparation and the reference preparation was good after meals.Conclusion In the state of fasting and postprandial single oral administration,the two kinds of pemirolast potassium tablets have good bio-equivalence.

Aim To establish a quantitative immunofluorescent bioactivity assay(ICW)for insulin glargine based on CHO-IN-SRB 1284 transgenic cells,and to study its equivalence with in-sulin bioassay of Ch.P.Methods The cells were diluted 25 times with 1.5 × 108 L-1 cell density plates and 1 500 μmol·L-1 insulin glargine,and then diluted with a 3-fold gradient se-ries.The cells were stimulated in microporous plates for 20 min.After fixation,permeation and antibody incubation.Quantitative immunofluorescence biological activity was detected by odyssey two-color infrared fluorescence imaging system.Results There was a good dose-effect relationship between the concentration of insulin glargine in ICW and its relative potency.The method had good specificity,and the relative accuracy,intermediate preci-sion and linearity met the requirements.The relative deviation of biological activity results of 7 batches of insulin glargine samples measured by the two methods was less than 10％.The results were analyzed by SPSS and SAS software,which showed that the methods were correlated and equivalent.Conclusions The quantitative immunofluorescence assay for the biological activity of insulin glargine can be established.The method has good spe-cificity,high accuracy and precision,and has correlation and e-quivalent with biotiter assay,which can be applied to in vitro ef-ficacy evaluation and quality control of insulin glargine.

Objective To investigate the mid-term effect and complications of arthroscopic popliteal tendon suture in the treatment of lateral meniscus injury.Methods From January 2016 to December 2020,the data of 57 patients with lateral meniscus popliteal tendon injury treated by arthroscopic popliteal tendon suture fixation were retrospectively analyzed,includ-ing 35 males and 22 females,aged from 18 to 47 years old with an average of(32.9±7.9)years old.Knee function was evaluat-ed using the International Knee Documentation Committee(IKDC)and Lysholm scores both before the operation and at the fi-nal follow-up.Meniscus healing was evaluated according to the postoperative Barrett standard.Wound healing complications,such as vascular injury,nerve injury,and lower extremity venous thrombosis,were recorded.Results All 57 patients were fol-lowed up for 12 to 58 months with an average of(38.1±14.9)months.The incisions of the patients after the operation were all Grade A healing without infection,popliteal tendon injury,blood vessel injury,nerve injury and lower extremity venous throm-bosis.The IKDC score increased from(49.7±3.6)points preoperatively to(88.5±4.4)points in the final follow-up(P＜0.05).The Lysholm score increased from(48.8±4.9)points preoperatively to(91.9±3.9)points at the final follow-up(P＜0.05).At 3,6 months and 1 year after operation,according to Barrett's criteria,54 cases were clinically healed,the healing rate was 94.7％(54/57).Conclusion This study preliminarily confirmed that arthroscopic suture technique can result in clinical sta-bility through suture and fixation of the meniscus in the injured lateral popliteal tendon area.No adverse effects on knee joint function were found in the mid-term follow-up after the operation.

Objective To explore early postoperative gait characteristics and clinical outcomes after total knee arthroplasty(TKA).Methods From February 2023 to July 2023,26 patients with unilateral knee osteoarthritis(KOA)were treated with TKA,including 4 males and 22 females,aged from 57 to 85 years old with an average of(67.58±6.49)years old;body mass in-dex(BMI)ranged from 18.83 to 38.28 kg·m-2 with an average of(26.43±4.15)kg·m-2;14 patients on the left side,12 pa-tients on the right side;according to Kellgren-Lawrence(K-L)classification,6 patients with grade Ⅲ and 20 patients with grade Ⅳ;the courses of disease ranged from 1 to 14 years with an average of(5.54±3.29)years.Images and videos of standing up and walking,walking side shot,squatting and supine kneeling were taken with smart phones before operation and 6 weeks after operation.The human posture estimation framework OpenPose were used to analyze stride frequency,step length,step length,step speed,active knee knee bending angle,stride length,double support phase time,as well as maximum hip flexion angle and maximum knee bending angle on squatting position.Western Ontario and McMaster Universities(WOMAC)arthritis index and Knee Society Score(KSS)were used to evaluate clinical efficacy of knee joint.Results All patients were followed up for 5 to 7 weeks with an average of(6.00±0.57)weeks.The total score of WOMAC decreased from(64.85±11.54)before op-eration to(45.81±7.91)at 6 weeks after operation(P＜0.001).The total KSS was increased from(101.19±9.58)before opera-tion to(125.50±10.32)at 6 weeks after operation(P＜0.001).The gait speed,stride frequency and stride length of the affected side before operation were(0.32±0.10)m·s-1,(96.35±24.18)steps·min-1,(0.72±0.14)m,respectively;and increased to(0.48±0.11)m·s 1,(104.20±22.53)steps·min-1,(0.79±0.10)m at 6 weeks after operation(P＜0.05).The lower limb support time and active knee bending angle decreased from(0.31±0.38)sand(125.21±11.64)° before operation to(0.11±0.04)s and(120.01±13.35)° at 6 weeks after operation(P＜0.05).Eleven patients could able to complete squat before operation,13 patients could able to complete at 6 weeks after operation,and 9 patients could able to complete both before operation and 6 weeks after operation.In 9 patients,the maximum bending angle of crouching position was increased from 76.29° to 124.11° before operation to 91.35° to 134.12° at 6 weeks after operation,and the maximum bending angle of hip was increased from 103.70° to 147.25° before operation to 118.61° to 149.48° at 6 weeks after operation.Conclusion Gait analysis technology based on artificial intelligence image recognition is a safe and effective method to quantitatively identify the changes of pa-tients'gait.Knee pain of KOA was relieved and the function was improved,the supporting ability of the affected limb was im-proved after TKA,and the patient's stride frequency,stride length and stride speed were improved,and the overall movement rhythm of both lower limbs are more coordinated.

Objective To explore the magnetic resonance imaging(MRI)manifestations of acute cerebral infarction(ACI)and the correlation between lipoprotein-associated phospholipase A2(Lp-PLA2),cystatin C(Cys C)and short-term prognosis.Methods A total of 110 ACI patients admitted to the department of neurology in our hospital from January 1,2022 to January 1,2023 were selected as the study objects.The clinical data and multimodal MRI were collected,and the serum Lp-PLA2 and Cys C levels of patients were detected.The patients were divided into the good prognosis group and the poor prognosis group according to the modified Rankin scale(mRS)score 90 days after onset.The predictive value of MRI manifestations and Lp-PLA2 and Cys C levels for short-term poor prognosis was analyzed.Results There were statistically significant differences in the time from onset to admission,National Institute of Health Stroke Scale(NIHSS)score on admission,hypertension or diabetes,coronary heart disease or atrial fibrillation of patients between the good prognosis group and the poor prognosis group(P<0.05).The proportions of patients with ischemic penumbra,HV positive,cortical-subcortical infarction,large perforating branch infarction,small perforating branch infarction,bilateral anterior circulation infarction,posterior circulation infarction,anterior-posterior circulation infarction,middle cerebral artery(MCA)stenosis or occlusion,both internal carotid artery(ICA)and MCA stenosis or occlusion,posterior cerebral artery(PCA)or vertebral artery(VA)stenosis or occlusion and hemorrhage transformation in the poor prognosis group were significantly higher than those in the good prognosis group(P<0.05).The Lp-PLA2 and Cys C levels of patients in the poor prognosis group were significantly higher than those in the good prognosis group(P<0.05).Small penetrating branch infarction,posterior circulation infarction,anterior-posterior circulation infarction,MCA stenosis or occlusion,both ICA and MCA stenosis or occlusion,hemorrhage transformation,serum Lp-PLA2 and Cys C had certain predictive value for patients with short-term poor prognosis(P<0.05).Conclusion MRI manifestations(ischemic penumbra,HV positivity,different types of cerebral infarction,and vascular stenosis)and serum Lp-PLA2 and Cys C levels can predict the short-term prognosis of ACI patients and provide important reference for the formulation of clinical treatment plans.

Objective To compare the efficacy of renal proximal renal artery denervation(pRDN)and full-length renal artery denervation(fRDN)for treatment of hypertension.Methods Fifty-six hypertensive patients were enrolled and randomly assigned to full-length renal artery denervation group(n=25)and proximal renal artery denervation group(n=31).After the procedure,24-hour ambulatory blood pressure monitoring(24 h-ABPM)at 6 months and office blood pressure at 12 months was recorded for statistical analysis.Results The blood pressure at follow-up reduced significantly in both groups,while there was no significant difference between groups.The baseline office blood pressure in fRDN group and pRDN group was(180±15)/(104±10)mmHg and(180±12)/(103±8)mmHg,respectively,which decreased to(142±9)/(82±7)mmHg and(143±10)/(83±6)mmHg at 12 months postoperatively(P＜0.001 within groups and P＞0.05 between groups).The baseline 24 h-ABPM in the two groups was(162±13)/(95±8)mmHg and(160±12)/(94±8)mmHg,respectively,which decreased to(142±11)/(83±7)mmHg and(141±8)/(81±7)mmHg at 6 months postoperatively(P＜0.001 within groups and P＞0.05 between groups).However,there was no significant difference in the reduction of office blood pressure and ambulatory blood pressure between the two groups.No treatment-related adverse events were observed.Conclusions pRDN has similar antihypertensive effect to fRDN.