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.

Portal vein embolization （PVE） can induce atrophy of the embolized lobe and compensatory regeneration of the non-embolized lobe. However， due to inadequate regeneration of future liver remnant （FLR） after PVE， some patients remain unsuitable for hepatectomy after PVE. In recent years， liver venous deprivation （LVD）， which combines PVE with hepatic vein embolization （HVE）， has induced enhanced FLR regeneration. Compared with associating liver partition and portal vein ligation for staged hepatectomy （ALPPS）， LVD triggers faster and more robust FLR regeneration， with lower incidence rate of postoperative complications and mortality rate. By reviewing related articles on LVD， this article introduces the effectiveness of LVD and analyzes the differences and safety of various technical paths， and it is believed that LVD is a safe and effective preoperative pretreatment method.

In recent years, cancer treatment methods and means are becoming more and more diversified, and single treatment methods often have limited efficacy, while the synergistic effect of immunity combined with chemotherapy can inhibit tumor growth more effectively. Based on this, we constructed a sodium alginate hydrogel composite system loaded with chemotherapeutic agents and tumor vaccines (named SA-DOX-NA) with a view to the combined use of chemotherapeutic agents and tumor vaccines. Firstly, the tumor vaccine (named NA) degradable under acidic conditions was constructed by in situ polymerization using chicken ovalbumin (OVA), acrylamide (AAM) and 2-(dimethylamino) ethyl methacrylate (DMAEMA) monomer. Then a hydrogel composite system SA-DOX-NA co-loaded with chemotherapeutic drug doxorubicin (DOX) and NA was prepared using sodium alginate as a matrix. The results showed that SA-DOX-NA had good in situ gel-forming ability and formed a mesh structure that could realize the co-loading of DOX and NA as well as the slow drug release. The electron microscopy results showed that SA-DOX-NA had good in situ gel-forming ability with good internal connectivity, and the three-dimensional mesh structure could realize the co-loading of DOX and NA as well as the slow drug release. The antitumor and immunomodulatory results showed that SA-DOX-NA both effectively inhibited the growth of tumor cells and efficiently promoted the proliferation and activation of DC2.4 dendritic cells without additional adjuvant. In summary, SA-DOX-NA exerts the dual efficacy of chemotherapy and immunotherapy for tumor treatment, and has a good application prospect in local tumor treatment.

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.

Pelvic acetabular fractures(PAFs)are one of the most common types of pelvic fractures,mostly high-energy injuries,with complex pelvic acetabular structure and limited surgical methods.The trauma of the acetabular fracture itself and the need for long-term bed rest after surgery cause particularly complicated clinical complications.Venous thromboembolism(VTE)is one of its high incidence and serious complications.This review mainly focuses on VTE after PAFs,and describes the epidemiology,risk factors and prevention measures of VTE,aiming to help improve the prognosis and avoid the occurrence of serious complications.

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 compare and analyze the clinical outcomes of the ortho-bridge system(OBS)and the proximal humeral internal locking system(PHILOS)for the treatment of humeral surgical neck fractures(HSNF)in the elderly.Methods A retrospective analysis was conducted on the clinical data of 80 elderly patients with HSNF admitted to our hospital.Patients were divided into the two groups based on different surgical methods,among which 30 patients treated with OBS were included into the OBS group and 50 patients treated with PHILOS were included into the PHILOS group.The operation indicators,postoperative recovery indicators,serum bone metabolism indexes[osteocalcin(OCN),N-terminal propeptide of type Ⅰ precollagen(PINP)and alkaline phosphatase(ALP)],callus score,shoulder joint function scores[Constant-Murley scale(CMS)score and Neer score],and incidence of complications of the two groups were compared.Results The operation time in the OBS group was longer than that in the PHILOS group,and the fracture healing time was shorter than that in the PHILOS group(P＜0.05).The levels of serum OCN,PINP,and ALP 1 month and 3 months after surgery in the OBS group were higher than those in the PHILOS group(P＜0.05).The callus scores 1 month,2 months,and 3 months after surgery in the OBS group were higher than those in the PHILOS group(P＜0.05).The CMS and Neer scores 1 month and 3 months after surgery in the OBS group were higher than those in the PHILOS group(P＜0.05).The incisions of patients in the two groups recovered well after surgery,achieving gradeⅠ healing without complications such as wound infection or nonunion.Conclusion Compared with PHILOS,the application of OBS in the treatment of elderly patients with HSNF has a better short-term clinical outcome,and can promote fracture healing.

Intramedullary needle(IMN)has the advantages of high healing rate and low incidence of complications in treatment of tibial fracture,and has become one of the most commonly used fixation methods for the treatment of tibial fracture.However,due to the patient's own factors,fracture location and fracture type,infection and surgical treatment,bone nonunion after IMN still occurs in clinic.Bone nonunion leads to the increase of medical cost and prolonged the hospitalization time of patients,which causes great pain to patients,and also brings great challenges to the treatment of orthopedic surgeons.Therefore,this paper reviews the influencing factors of bone nonunion after IMN for tibial fracture,in order to provide reference for clinical treatment.

Objective To retrospectively analyze the ultra-fast track anesthesia(UFTA)methods and perioperative anesthesia management experiences of transcatheter mitral valve edge-to-edge repair(TEER)in the treatment of functional mitral regurgitant.Methods In this retrospective study,patients underwent the TEER procedure and received UFTA in Fuwai Yunnan Hospital,from May 2022 to September 2022 for heart failure combined with moderate to severe or severe functional mitral regurgitant were included.Baseline,preoperative complications,cardial function and anesthesia classification,amino-terminal probrain natriuretic peptide(NT-proBNP),ultrasound examination results,surgery time,extubation time,intraoperative anesthetic and vasoactive drug,complications related to TEER and UFTA,perioperative,and postoperative 30-day and one-year follow-up data were collected.All perioperative clinical data were recorded and analyzed.Results A total of 30 patients were enrolled,11 patients(36.7％)were female,mean age was(63.6±6.1)years,NYHA classification IV 14 patients(46.7％),left ventricular ejection fraction(LVEF)(36.0±8.1)％,the end-diastolic volume of the left ventricle(66.0±8.2)mm,mitral regurgitation 4+14 patients(56.7％),3+17 patients(43.3％),NT-proBNP(1 934.1±1 973.5)pg/ml,1 patient(3.3％)used high-dose vasoactive drugs during surgery.All patients did not experience nausea,vomiting,delirium,respiratory depression,perioperative transesophageal echocardiography-related gastrointestinal bleeding,pericardial effusion,cerebrovascular accidents,emergency surgery or secondary intervention,or other serious adverse events within 24 hours after surgery.No 30-day all-cause death occurred;the mean postoperative hospital stay was(7.4±2.8)days.All patients completed one-year follow-up,LVEF(37.6±11.1)％,the end-diastolic volume of the left ventricle(63.2±8.6)mm,mitral regurgitation 2+7 patients(23.3％),1+23 patients(76.7％),NT-proBNP(1 949.2±2 576.6)pg/ml.Conclusions Ultra-fast track anesthesia can be safely applied to TEER in treating functional mitral regurgitant patients.

Mitral valve prolapse is one of the common causes of mitral regurgitation.Mitral valve prolapse complicated with leaflet cleft is rare in clinical practice,which most often undergo surgical mitral valve repair or mitral valve replacement.We report a case of mitral valve prolapse with posterior leaflet cleft treated by transcatheter edge-to-edge mitral valve repair,in order to provide a model for similar cases.