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.

OBJECTIVE To develop a population pharmacokinetic （PPK） model for mycophenolate mofetil active metabolite mycophenolic acid （MPA） in children with primary IgA nephropathy， explore the factors affecting the pharmacokinetic parameters of MPA， and provide a basis for clinical individualized therapy. METHODS Retrospective collection was conducted on 636 concentrations and clinical data from 47 pediatric patients with primary IgA nephropathy. PPK analysis was carried out by using the nonlinear mixed-effects model； the covariates were tested with a stepwise method. Goodness-of-fit plots， Bootstrap and visual predictive check were employed to evaluate the final model. RESULTS The pharmacokinetics of MPA in children with IgA nephropathy in vivo conformed to the first-order absorption and elimination two-compartment model （objective function value of 3 276.31）. Covariate analysis suggested that body weight and albumin （ALB） levels were significant influencing factors on apparent clearance rate and apparent distribution volume. The typical values of PPK parameters of MPA in the final model were as follows： the central room had a distributed volume of 5.79 L， the clearance rate was 4.06 L/h， the volume of peripheral ventricular distribution was 430.93 L， the clearance rate between compartments was 15.40 L/h， the oral absorption rate constant was 1.29 h－1. After verification， most of the predicted corrected observed concentration points were within the 90% confidence interval of the predicted corrected simulated concentration， indicating that the MPA final model had good predictive performance. CONCLUSIONS The PPK model of MPA in children with primary IgA nephropathy is established in this study， identifying body weight and ALB levels are significant factors affecting MPA metabolism.

Platycodonis Radix is the dry root of Platycodon grandiflorum of Campanulaceae, which has a variety of pharmacological effects and is a commonly used bulk Chinese medicine. In this study, the chloroplast genome sequences of six P. grandiflorum from different producing areas has been sequenced with Illumina HiSeq X Ten platform. The specific DNA barcodes were screened, and the germplasm resources and genetic diversity were analyzed according to the specific barcodes. The total length of the chloroplast genome of 6 P. grandiflorum samples was 172 260-172 275 bp, and all chloroplast genomes showed a typical circular tetrad structure and encoded 141 genes. The comparative genomics analysis and results of amplification efficiency demonstrated that trnG-UCC and ndhG_ndhF were the potential specific DNA barcodes for identification the germplasm resources of P. grandiflorum. A total of 305 P. grandiflorum samples were collected from 15 production areas in 9 provinces, for which the fragments of trnG-UCC and ndhG_ndhF were amplificated and the sequences were analyzed. The results showed that trnG-UCC and ndhG_ndhF have 5 and 11 mutation sites, respectively, and 5 and 7 haplotypes were identified, respectively. The combined analysis of the two sequences formed 13 haplotypes (named Hap1-Hap13), and Hap4 is the main genotype, followed by Hap1. The unique haplotypes possessed by the three producing areas can be used as DNA molecular tags in this area to distinguish from the germplasm resources of P. grandiflorum from other areas. The haplotype diversity, nucleotide diversity and genetic distance were 0.94, 4.79×10^-3 and 0.000 0-0.020 3, respectively, suggesting that the genetic diversity was abundant and intraspecific kinship was relatively close. This study laid a foundation for the identification of P. grandiflorum, the protection and utilization of germplasm resources, and molecular breeding.

Objective     To investigate the relationship between preoperative mean daily step counts and pulmonary complications after thoracoscopic lobectomy in elderly patients. Methods     From 2018 to 2021, the elderly patients with pulmonary complications after thoracoscopic lobectomy were included. A 1∶1 propensity score matching was performed with patients without pulmonary complications. The clinical data were compared between the two groups. Results    Totally, 100 elderly patients with pulmonary complications were enrolled, including 78 males and 22 females, aged 66.4±4.5 years. And 100 patients without pulmonary complications were matched, including 71 males and 29 females aged 66.2±5.0 years. There was no significant difference in the preoperative data between the two groups (P>0.05). Compared to the patients with pulmonary complications, the ICU stay was shorter (8.1±4.4 h vs. 12.9±7.5 h, P<0.001), the first out-of-bed activity time was earlier (8.8±4.5 h vs. 11.2±6.1 h, P=0.002), and the tube incubation time was shorter (19.3±9.2 h vs. 22.5±9.4 h, P=0.015) in the patients wihout pulmonary complications. There was no statistical difference in other perioperative data between the two groups (P>0.05). The mean daily step counts in the pulmonary complications group were significantly less than that in the non-pulmonary complications group (4 745.5±2 190.9 steps vs. 6 821.1± 2 542.0 steps, P<0.001). The daily step counts showed an upward trend for three consecutive days in the two groups, but the difference was not significant. Conclusion     The decline of preoperative mean daily step counts is related to pulmonary complications after thoracoscopic lobectomy in elderly patients. Recording daily step counts can promote preoperative active exercise training for hospitalized patients.

BACKGROUND:For dislocation of acromioclavicular joint induced by coracoclavicular ligament fracture,single EndoButton Plate reconstruction and double EndoButton Plates reconstruction are common repair methods.Further study on the stress distribution and fracture risk of the two repair methods is of great significance. OBJECTIVE:To study the biomechanical properties of the coracoclavicular ligament,and compare the fixation effect,stress distribution and failure mode of single and double EndoButton Plates reconstruction. METHODS:(1)Finite element simulation analysis:Mimics,Wrap and SolidWorks were used to establish normal coracoclavicular ligament,single EndoButton Plate reconstruction and double EndoButton Plates reconstruction.Ansys software was used to analyze the stress and deformation of the scapula and clavicle of each model under vertical load.(2)Sample experiment:Fifteen intact scapular-clavicle specimens were randomly grouped into five groups,with three specimens in each group.In group A,the acromioclavicular ligament was severed and the coracoclavicular ligament remained intact.In group B,acromioclavicular ligaments and trapeoid ligaments were severed,leaving intact conical ligaments.In group C,acromioclavicular ligaments and conical ligaments were cut off,and the intact traprex ligaments were retained.In group D,acromioclavicular and coracoclavicular ligaments were severed,and coracoclavicular ligaments were repaired by single EndoButton Plate reconstruction.In group E,acromioclavicular and coracoclavicular ligaments were severed,and the coracoclavicular ligaments were repaired by double EndoButton Plates reconstruction.The mechanical experiment was carried out by a mechanical testing machine to analyze the biomechanical status,stress distribution and failure patterns of the scapular-clavicle and clavicle. RESULTS AND CONCLUSION:(1)Finite element simulation analysis:The average stress of coracoclavicular ligament attached specimens was the lowest,and the risk of coracoclavicular fracture was less than that of single and double EndoButton Plates reconstruction.The mean stress of the coracoid process was similar in single and double EndoButton Plates reconstruction,and the fracture risk was similar.(2)Sample experiment:In groups A,B,C,D and E,the stiffness of specimens was(26.4±3.5),(19.8±2.8),(21.3±3.2),(57.7±4.1),and(46.2±2.8)N/mm,respectively;the ultimate loads were(545.5±53.7),(360.1±42.1),(250.9±44.4),(643.5±39.1),and(511.9±31.7)N,respectively;global stiffness in groups D and E was higher than that in group A(P=0.000 06,0.000 3);ultimate load in group D was higher than that in group A(P<0.05);the ultimate load was not significantly different between the group E and group A(P>0.05).Ligament fracture was observed in groups A,B and C and coracoid process fracture was found in groups D and E.(3)These results suggest that from the biomechanical analysis,Single EndoButton Plate reconstruction and double EndoButton Plates reconstruction are effective treatment techniques for coracoclavicular ligament fracture in acromioclavicular joint dislocation,but increase the risk of fracture.The double EndoButton Plates reconstruction dispersed the stress of the steel plate and reduced the contact force between the steel plate and bone,but slightly reduced the ultimate bearing capacity.Single and double EndoButton Plates reconstruction should be selected according to the actual clinical situation.

BACKGROUND:Accurate reduction of ankle fractures under direct vision has become a common understanding among foot and ankle surgeons.How to fully expose free or compressed fragments of the posterior ankle remains one of the most challenging problems. OBJECTIVE:To explore the clinical efficiency of the para-Achilles tendon approach in exposing and repositioning the posterior malleolus sandwich fracture. METHODS:A retrospective study was made for 26 patients with posterior malleolus sandwich fracture treated with open reduction and internal fixation via para-Achilles tendon approach from January to December 2020 in The Second People's Hospital of Dalian.21 of 26 cases were managed with the lateral approach of Achilles tendon and 5 cases were managed with the medial approach of Achilles tendon.There were 19 males and 7 females,with the age of 24-69 years,averagely 38.6 years.The operation time and postoperative complications were recorded.The fracture reduction condition was evaluated by Burwell-Charnley imaging standard.Before operation,3 months after operation and last follow-up,visual analog scale score,ankle plantar flexion and dorsiflexion and American Orthopedic Foot&Ankle Society Ankle Hind Score were used to evaluate the treatment effect. RESULTS AND CONCLUSION:(1)All 26 patients were followed up for an average of 14.6 months(range 13-18 months).The operation time was 52-85 minutes(average 64.2 minutes).(2)Part of the skin edge of the lateral malleolus incision was necrotic in one patient and healed completely after a dressing change.Incision healing of the other patients was in one stage.(3)Through Burwell-Charnley imaging standard,anatomical reductions were obtained in 24 of 26,and good reductions were in 2 of 26,with an excellent and good rate of 100%.(4)At the last follow-up,the visual analog scale score(1.19±0.40)was significantly lower than the preoperative score(6.81±0.80)(P<0.01).Ankle plantar flexion(33.5±5.02)° and ankle plantar back stretch(17.23±0.99)° were significantly increased compared with preoperative data(14.58±2.50)° and(5.81±1.02)°(P<0.01).American Orthopedic Foot&Ankle Society Ankle Hind Score was improved to(89.31±3.62)points compared to preoperative(46.00±5.45)points(P<0.01).The results were excellent in 23 patients and good in 3 patients,with an excellent and good rate of 100%.(5)It is concluded that the open reduction and internal fixation via the para-Achilles tendon approach for the treatment of posterior malleolus sandwich fracture were efficient with decreased operation time,satisfying fracture reduction,fewer complications,satisfactory motion range,and functional recovery.

Objective:To analyze the clinicopathological features of gastric oxyntic gland neo-plasms.Methods:Forty-nine cases of stomach oxyntic gland neoplasms including oxyntic gland adenoma(OGA)and gastric adenocarcinoma of the fundic gland type(GA-FG)diagnosed in the Sec-ond Hospital of Shandong University from January 2016 to December 2020 were selected.The clini cal information,endoscopic appearance,histological features and immunophenotype were analyzed retrospectively,and followed up.Results:Age of the gastric oxyntic gland neoplasm patients ranged from 19 to 83 years old,with an average age of(57.3±2.4)years old.The male-to-female ratio was 24:25.Most of the lesions were located in the gastric body(27/49)and fundus(15/49).There were four endoscopic phenotypes:flat bulging,polypoid,flat and depression.In some lesions,there were dilated dendritic vessels.48 cases were single onset.The mean maximum diameter of lesions was(3.9±0.5)mm(1.0～7.0 mm).Seven cases showed submucosal invasion,and the inva-sion depth was less than 500 μm.The tumor consists of the dense glandular and the glandular con-nects to form a strip shape,which is irregularly branched and labyrinthlike under the microscope.These tumor cells were well differentiated and the morphology was similar to oxyntic gland cells.The chief cells were the predominant cells.The nucleus was mildly enlarged with slight pleomorphism and the mitosis was uncommon.The oxyntic gland neoplasms of the stomach were diffusely posi-tive for Mucin-6(MUC6)(100％)and Pepsinogen Ⅰ(83％),focally positive for H+/K+-ATPase(58％).Conclusions:The stomach oxyntic gland neoplasm is a new histology type with unique clinico-pathological features.The incidence of this neoplasm is low and the prognosis is good but it still needs long-term follow-up.

Ankylosing spondylitis (AS) combined with lower cervical fracture is often categorized into unstable fracture, with a high incidence of neurological injury and a high rate of disability and morbidity. As factors such as shoulder occlusion may affect the accuracy of X-ray imaging diagnosis, it is often easily misdiagnosed at the primary diagnosis. Non-operative treatment has complications such as bone nonunion and the possibility of secondary neurological damage, while the timing, access and choice of surgical treatment are still controversial. Currently, there are no clinical practice guidelines for the treatment of AS combined with lower cervical fracture with or without dislocation. To this end, the Spinal Trauma Group of Orthopedics Branch of Chinese Medical Doctor Association organized experts to formulate Clinical guidelines for the treatment of ankylosing spondylitis combined with lower cervical fracture in adults ( version 2024) in accordance with the principles of evidence-based medicine, scientificity and practicality, in which 11 recommendations were put forward in terms of the diagnosis, imaging evaluation, typing and treatment, etc, to provide guidance for the diagnosis and treatment of AS combined with lower cervical fracture.

The uniqueness of the location of large general hospitals in urban areas determines that the contradiction between space constraints and medical expansion has become a problem of management bottleneck.The situation that expert visits are too concentrated on a certain working day morning has been significantly improved by carrying out peak load shifting in the visiting arrangements and visiting units of large general hospitals through the Total Quality Management theory and continuous improvement of work mode,greatly alleviating public transportation congestion around the hospital.Through the internal construction of the quality of outpatient clinics,it can effectively improve the patients'sense of access to health care.

This study using maltodextrin as raw material, 1%-5% polyvinylpyrrolidone K30 as template agent, 1%-5% ammonium bicarbonate as pore-forming agent, curcumin and ibuprofen as model drugs. Porous maltodextrin was prepared by template and pore-forming agent methods, respectively. The structure and drug delivery behavior of porous maltodextrin prepared by different technologies were comprehensively characterized. The results showed that the porous maltodextrin prepared by pore-forming agent method had larger specific surface area (6.449 4 m²·g^-1) and pore size (32.804 2 nm), which was significantly better than that by template agent method (3.670 2 m²·g^-1, 15.278 5 nm). The adsorption kinetics between porous maltodextrin prepared by pore-forming agent method and curcumin were suitable for quasi-first order adsorption kinetic model, and that between porous maltodextrin and ibuprofen were suitable for quasi-second order adsorption kinetic model. While the adsorption kinetics between porous maltodextrin prepared by template agent method and two model drugs were both suitable for the quasi-first order adsorption kinetic model. In addition, the dissolution behavior analysis showed that the porous maltodextrin prepared by the two technologies can significantly improve the dissolution behavior of insoluble drugs, and the drug release was both carried out by diffusion mechanism, which suitable for the Peppas kinetic release model, but the porous maltodextrin prepared by template agent method had a faster release rate. The change of nozzle diameter had no significant effect on the adsorption process and drug release behavior of porous maltodextrin. In conclusion, the porous maltodextrins prepared by two different technologies were both beneficial to the delivery of insoluble drugs, and the template agent method was the best for delivery of insoluble drugs. This study can provide theoretical basis for the preparation of porous particles, promote the application of porous particles in insoluble drugs, and improve the bioavailability of insoluble drugs.