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.

All-trans retinoic acid(ATRA)is able to induce promyelocytic differentiation effectively.However,its role in the process of erythroid differentiation remains unclear.To investigate the role of AT-RA in the process of erythroid differentiation and its epigenetic regulatory mechanism,we established an induced leukemia cell K562 model in this study.Firstly,hemin was used to induce the differentiation of K562 cells into erythroid cells.The results of flow cytometry showed that ATRA affected the lineage changes of cells during erythroid differentiation and blocked the process of cell differentiation.After AT-RA treatment of differentiating cells,the expression level of erythroid differentiation-related genes de-creased.Through chromatin conformational capture(3C),formaldehyde-assisted separation of regulatory elements(FAIRE),chromatin immunoprecipitation(ChIP)techniques,the epigenetic mechanism was explored and it was found that after ATRA treatment of cells,the chromatin accessibility within the β-glo-bin family gene locus decreased,and the frequency of interaction between the locus control region(LCR)and its target gene promoter decreased.The decrease in the chromatin accessibility of the gene locus led to a decrease in the enrichment frequency of erythroid-related transcription factors GATA binding protein 1(GATA1),LIM domain binding 1(LDB1),LIM domain only 2(LMO2),and BHLH transcription factor 1(TAL1)at the promoter regions of the LCR and the gene locus of the globin family.The above results indicate that the ATRA treatment of differentiating cells leads to a decrease in the chromatin acces-sibility of erythroid differentiation-related genes,and a more closed chromatin structure hinders the bind-ing of LCR-recruiting transcription factors to the promoter regions of genes,thereby further repressing the expression of β-globin family genes.This dynamic process elucidates the epigenetic mechanism of ATRA in regulating erythroid differentiation.

Objective:To explore the feasibility of establishing combat readiness blood bank with low titer group O whole blood and group A plasma.Methods:The Galileo automatic blood analyzer was used to detect the titers of IgM anti-A and anti-B antibodies in the samples of group O blood donors and IgM anti-B titer in the samples of group A blood donors.Group O blood donors with antibody titers below 128 were selected and included in the mobile blood bank for combat readiness,group A plasma with anti-B titer lower than 128 and group O whole blood with antibody titers below 128 were included in the combat readiness entity blood bank.Results:A total of 1 452 group O blood donors were selected,and the anti-A/B antibody titers were detected.Both antibody titers were distributed below 512,and both peak values of sample distribution were at titer 4.The proportion of samples with titers＞128 for both antibodies was relatively low.There was a significant positive correlation between the titers of the two antibodies(r=0.383),and the proportion of samples with IgM anti-A titer higher than IgM anti-B titer was relatively high.1 335(91.94％)group O blood donors with IgM anti-A and anti-B antibody titers＜128 could be included in the mobile blood bank.The anti-B titer of group A blood was detected in 512 cases and the results showed that as the antibody titer increased,the proportion of blood donors gradually decreased.99.8％of group A blood donors had anti-B antibody titer less than 128,and only one case did not meet the inclusion criteria.Conclusion:The proportion of group O blood donors whose whole blood meet the low antibody titer standard is high,and almost all plasma of group A blood donors meet the low titer standard,which improves the blood supply rate in emergencies.

Objective:To explore the influence of environment temperature on the incidence of testicular torsion.Methods:We collected the clinical data on 172 cases of testicular torsion diagnosed in the Second Hospital of Hebei Medical University from De-cember 2013 to December 2020.According to the local environment temperature on the day of onset,we divided the patients into groups A(below 0℃),B(0-10℃),C(10-20℃)and D(above 20℃),and compared the incidence rates of testicular torsion among the four groups,followed by correlation analysis.Results:The incidence rate of testicular torsion was 12.8％(n=22)in group A,35.5％(n=61)in B,34.9％(n=60)in C and 16.9％(n=29)in D,the highest at 0-10℃ in group B,with sta-tistically significant difference among the four groups(x2=29.07,P＜0.001).Spearman correlation analysis indicated that the inci-dence of testicular torsion was negatively correlated with the environment temperature(r=-0.261,P＜0.01),with no statistically significant difference among different seasons(x2=5.349,P＞0.05),but higher in autumn and winter than in the other two sea-sons.Conclusion:The incidence of testicular torsion is negatively correlated with the environment temperature,elevated when the temperature decreases,but has no statistically significant difference among different seasons,though relatively higher in autumn and winter.

Objective:To assess the deformation of the bladder-neck opening and the impact of the bladder-neck angle(BNA)on urination in male patients by fluid-structure interaction(FSI)analysis.Methods:We established geometric models of the blad-der,prostate and urethra were established,incorporating both normal and enlarged BNAs,and assessed the effects of BNA alteration on urinary flow by FSI simulation of the flow rate and pressure of the urine within the bladder,bladder neck and urethra,and that of pros-tate displacement as well.We retrospectively analyzed the clinical data on 145 male patients from the Second Hospital of Hebei Medical University between June 2020 and June 2023,39 with acute urine retention(the AUR group)and 106 without(the non-AUR group),and evaluate the impact of BNA on urination based on the urinary flow rate and prostate volume.Results:Comparative simulation a-nalysis showed significant differences in the total urethral pressure and flow rate between the normal and enlarged BNA models(P＜0.05).The maximum prostate displacement was found at the bladder neck,with moderate displacement and unchanged urethral diame-ter in the normal BNA model,but significant displacement and a reduced urethral opening diameter in the enlarged BNA model.FSI analysis confirmed an evident impact of enlarged BNA on urination,more significant in the AUR than in the non-AUR patients(P＜0.05).The BNAs in the patients with the maximum urinary flow rate(Qmax)of＜10,10-15 or＞15 ml/s were 83.7°±2.5°,67.5°±1.8° and 65.1°±4.8° respectively,with statistically significant difference between the former one and the latter two groups(P＜0.05).The BNAs in the patients with normal prostate volume or BPH of grade Ⅰ,Ⅱ,Ⅲ or Ⅳ were 65.0°±3.7°,67.2°±3.1°,71.5°±2.0°,82.8°±3.5° and 105.8°±6.0°,respectively(P＜0.05),with statistically significant difference between BPH grades Ⅲ and Ⅳ(P＜0.05)as well as between these two and the other three groups(P＜0.05),but not among the normal prostate volume,BPH grade Ⅰ and BPH grade Ⅱ groups(P＞0.05).Spearman correlation analysis indicated that BNA was strongly correlated with total prostate volume(TPV),transition zone volume(TZV),intravesical prostatic protrusion(IPP),prostatic urethral angle(PUA),IPSS,and Qmax(P＜0.05).Conclusion:Changes in BNA affect urination and are closely associated with the se-verity of prostate hyperplasia.The BNA may be an important anatomical factor for assessing the severity of lower urinary tract symptoms in BPH patients.

AIM To investigate the effects of total Astragalus saponins on the improvement of sarcopenia in a rat model of type 2 diabetes mellitus(T2DM).METHODS The rats were divided into the normal group for a normal feeding and the model group for the feeding of high-sugar and high-fat diet combined with intraperitoneal injection of STZ to establish a T2DM model.The successful model rats were randomly divided into the model group,the metformin group(0.2 g/kg)and the total Astragalus saponins group(80 mg/kg),and given corresponding doses of drugs by gavage.After 12 weeks administration,the rats had their FBG,postprandial blood glucose(PG2h)and wet weight of skeletal muscle measured;their serum levels of INS,C-peptide(C-P),IGF-1,TNF-α and IL-1β detected by ELISA;their morphological changes of skeletal muscle observed by HE staining;their protein expressions of PI3K,p-Akt,mTOR,S6K1,FoxO1 and Murf1 in skeletal muscle detected by Western blot;and their mRNA expressions of Pi3k,Akt and mtor in skeletal muscle detected by RT-qPCR method.RESULTS Compared with the model group,the total Astragalus saponins group displayed decreased levels of FBG,PG2h,OGTT-AUC,HOMA-IR,TNF-α and IL-1β(P＜0.01);increased levels of INS,C-P,IGF-1 and wet weight of skeletal muscle(P＜0.05,P＜0.01);improved skeletal muscle atrophy and increased protein expressions of PI3K,p-Akt,mTOR and S6K1 in skeletal muscle(P＜0.05,P＜0.01);decreased protein expressions of FoxO1 and Murf1(P＜0.05,P＜0.01);and increased mRNA expressions of Pi3k,Akt and mtor(P＜0.01).CONCLUSION The improvement effects of total Astragalus saponins on sarcopenia in T2DM rats may be associated with the regulation of PI3K/Akt/mTOR and PI3K/Akt/FoxO1 pathways.

Objective To analyze the stresses in implanted titanium solid and bone trabecular prosthesis hip replacements.Methods A femur model was built inversely based on Mimics software,and optimized using Geomagic software,and then materialized by SolidWorks software.The osteotomized femur was assembled with the metal femoral stem to form a model,and then the model was imported into ABAQUS for finite element calculation.The upper femur was divided into four regions in different states of integration:medial proximal point(small trochanter region),lateral proximal region(large trochanter region),proximal point of the femoral stem(region around the mid-portion of the styloid process)and distal region(around the end of the styloid process and distal portion).Calculations were carried out over the femoral stresses before and after implantation of titanium solid and trabecular prostheses under gait and stair-climbing loads and the interfacial stresses when the region was unintegrated.The type of deformation at the bone interface was analyzed by means of a stress ellipsoid.Results At the small trochanter region,the stress shielding rates of the trabecular prosthesis under gait and stair climbing loads were reduced by 20.5％and 14.7％compared to the titanium solid prosthesis,respectively.In case of different integration states of the titanium solid prosthesis,the interface tensile stresses under the gait and stair climbing loads were up to 10.842 MPa and 12.900 MPa,and the shear stresses reached 7.050 MPa and 6.805 MPa,respectively;in case of different integration states of the trabecular prosthesis,the interface tensile stresses under the gait and stair climbing loads were up to 3.858 MPa and 4.389 MPa,and the shear stresses reached 4.156 MPa and 3.854 MPa,respectively.Under the 2 different loads,the inboard shear stress ellipsoid of the interface opened toward the sides and the bone interface showed tensile deformation;the outboard shear stress ellipsoid of the interface opened up and down and had compressive deformation.Conclusion After total hip arthroplasty,the overall performance of the trabecular prosthesis is better than that of the titanium solid prosthesis.The unintegrated edges of the prosthesis-bone interface are susceptible to stress concentrations and distortion which may result in occurrence of failures.[Chinese Medical Equipment Journal,2024,45(3):29-35]

OBJECTIVE: To determine the role of Tripterygium wilfordii multiglycoside (TGW) in the treatment of psoriatic dermatitis from a cellular immunological perspective. METHODS: Mouse models of psoriatic dermatitis were established by imiquimod (IMQ). Twelve male BALB/c mice were assigned to IMQ or IMQ₊TGW groups according to a random number table. Histopathological changes in vivo were assessed by hematoxylin and eosin staining. Ratios of immune cells and cytokines in mice, as well as PAM212 cell proliferation in vitro were assessed by flow cytometry. Pro-inflammatory cytokine expression was determined using reverse transcription quantitative polymerase chain reaction. RESULTS: TGW significantly ameliorated the severity of IMQ-induced psoriasis-like mouse skin lesions and restrained the activation of CD45⁺ cells, neutrophils and T lymphocytes (all P<0.01). Moreover, TGW significantly attenuated keratinocytes (KCs) proliferation and downregulated the mRNA levels of inflammatory cytokines including interleukin (IL)-17A, IL-23, tumor necrosis factor α, and chemokine (C-X-C motif) ligand 1 (P<0.01 or P<0.05). Furthermore, it reduced the number of γ δ T17 cells in skin lesion of mice and draining lymph nodes (P<0.01). CONCLUSIONS TGW improved psoriasis-like inflammation by inhibiting KCs proliferation, as well as the associated immune cells and cytokine expression. It inhibited IL-17 secretion from γ δ T cells, which improved the immune-inflammatory microenvironment of psoriasis.
Male ; Animals ; Mice ; Tripterygium ; Psoriasis/drug therapy* ; Keratinocytes ; Skin Diseases/metabolism* ; Cytokines/metabolism* ; Imiquimod/metabolism* ; Dermatitis/pathology* ; Disease Models, Animal ; Mice, Inbred BALB C ; Skin/metabolism*

Objective:To explore if miR-133a is involved in the occurrence and development of hepatocellular carcinoma(HCC)via regulating G6PD.Methods:Bioinformatics analysis predicted the binding sites of miR-133a and G6PD;RT-PCR or western blot was used to assess the expres-sion of miR-133a and G6PD in HCC tissues and the adjacent normal tissues;CCK-8 and flow cy-tometry assays were performed to evaluate the effects of miR-133a/G6PD on cell proliferation,apop-tosis;Fluorescent reporter gene and western blot assays were used to assess the effect of miR-133a on G6PD expression.Results:miR-133a expression was decreased in HCC tissues while G6PD was increased(P0.01);Up-regulation of miR-133a significantly reduced G6PD expression(P＜0.01);up-reg-ulation of miR-133a inhibited cell growth and promoted cell apoptosis(P＜0.05),whereas these effects induced by miR-133a over-expression were all abolished when G6PD was up-regulated(P＜0.01).Conclusion:miR-133a represses the occurrence and development of HCC via targeting G6PD.

Objective To evaluate the bioequivalence and safety of ezetimibe tablets in healthy Chinese subjects.Methods The study was designed as a single-center,randomized,open-label,two-period,two-way crossover,single-dose trail.Subjects who met the enrollment criteria were randomized into fasting administration group and postprandial administration group and received a single oral dose of 10 mg of the subject presparation of ezetimibe tablets or the reference presparation per cycle.The blood concentrations of ezetimibe and ezetimibe-glucuronide conjugate were measured by high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS),and the bioequivalence of the 2 preparations was evaluated using the WinNonlin 7.0 software.Pharmacokinetic parameters were calculated to evaluate the bioequivalence of the 2 preparations.The occurrence of all adverse events was also recorded to evaluate the safety.Results The main pharmacokinetic parameters of total ezetimibe in the plasma of the test and the reference after a single fasted administration:Cmax were(118.79±35.30)and(180.79±51.78)nmol·mL-1;tmax were 1.40 and 1.04 h;t1/2 were(15.33±5.57)and(17.38±7.24)h;AUC0-t were(1 523.90±371.21)and(1 690.99±553.40)nmol·mL-1·h;AUC0-∞ were(1 608.70±441.28),(1 807.15±630.00)nmol·mL-1·h.The main pharmacokinetic parameters of total ezetimibe in plasma of test and reference after a single meal:Cmax were(269.18±82.94)and(273.93±87.78)nmol·mL-1;Tmax were 1.15 and 1.08 h;t1/2 were(22.53±16.33)and(16.02±5.84)h;AUC0_twere(1 463.37±366.03),(1 263.96±271.01)nmol·mL-1·h;AUC0-∞ were(1 639.01±466.53),(1 349.97±281.39)nmol·mL-1·h.The main pharmacokinetic parameters Cmax,AUC0-tand AUC0-∞ of the two preparations were analyzed by variance analysis after logarithmic transformation.In the fasting administration group,the 90％CI of the log-transformed geometric mean ratios were within the bioequivalent range for the remaining parameters in the fasting dosing group,except for the Cmax of ezetimibe and total ezetimibe,which were below the lower bioequivalent range.The Cmax of ezetimibe,ezetimibe-glucuronide,and total ezetimibe in the postprandial dosing group was within the equivalence range,and the 90％CI of the remaining parameters were not within the equivalence range for bioequivalence.Conclusion This test can not determine whether the test preparation and the reference preparation of ezetimibe tablets have bioequivalence,and further clinical trials are needed to verify it.