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.

Aim To investigate the therapeutic effect of the MW-9 on ulcerative colitis(UC)and reveal the underlying mechanism, so as to provide a scientific guidance for the MW-9 treatment of UC. Methods The model of lipopolysaccharide(LPS)-stimulated RAW264.7 macrophage cells was established. The effect of MW-9 on RAW264.7 cells viability was detected by MTT assay. The levels of nitric oxide(NO)in RAW264.7 macrophages were measured by Griess assay. Cell supernatants and serum levels of inflammatory cytokines containing IL-6, TNF-α and IL-1β were determined by ELISA kits. Dextran sulfate sodium(DSS)-induced UC model in mice was established and body weight of mice in each group was measured. The histopathological damage degree of colonic tissue was assessed by HE staining. The protein expression of p-p38, p-ERK1/2 and p-JNK was detected by Western blot. Results MW-9 intervention significantly inhibited NO release in RAW264.7 macrophages with IC50 of 20.47 mg·L-1 and decreased the overproduction of inflammatory factors IL-6, IL-1β and TNF-α(P<0.05). MW-9 had no cytotoxicity at the concentrations below 6 mg·L-1. After MW-9 treatment, mouse body weight was gradually reduced, and the serum IL-6, IL-1β and TNF-α levels were significantly down-regulated. Compared with the model group, MW-9 significantly decreased the expression of p-p38 and p-ERK1/2 protein. Conclusions MW-9 has significant anti-inflammatory activities both in vitro and in vivo, and its underlying mechanism for the treatment of UC may be associated with the inhibition of MAPK signaling pathway.

Objective To study the application of CE-Chirp in the evaluation of hearing impairment in forensic medicine by testing the auditory brainstem response(ABR)in adults using CE-Chirp to ana-lyze the relationship between the V-wave response threshold of CE-Chirp ABR test and the pure tone hearing threshold.Methods Subjects(aged 20-77 with a total of 100 ears)who underwent CE-Chirp ABR test in Changzhou De'an Hospital from January 2018 to June 2019 were selected to obtain the V-wave response threshold,and pure tone air conduction hearing threshold tests were conducted at 0.5,1.0,2.0 and 4.0 kHz,respectively,to obtain pure tone listening threshold.The differences and statistical differences between the average pure tone hearing threshold and V-wave response threshold were compared in different hearing levels and different age groups.The correlation,differences and statistical differences between the two tests at each frequency were analyzed for all subjects.The lin-ear regression equation for estimating pure tone hearing threshold for all subjects CE-Chirp ABR V-wave response threshold was established,and the feasibility of the equation was tested.Results There was no statistical significance in the CE-Chirp ABR response threshold and pure tone hearing threshold dif-ference between different hearing level groups and different age groups(P>0.05).There was a good correlation between adult CE-Chirp ABR V-wave response threshold and pure tone hearing threshold with statistical significance(P<0.05),and linear regression analysis showed a significant linear correla-tion between the two(P<0.05).Conclusion The use of CE-Chirp ABR V-wave response threshold can be used to evaluate subjects'pure tone hearing threshold under certain conditions,and can be used as an audiological test method for forensic hearing impairment assessment.

Objective To investigate the value of magnetic resonance imaging(MRI)T2-mapping in evaluating the activity of Graves ophthalmopathy(GO).Methods A total of 64 patients with GO in the Department of Endocrinology,the First Affiliated Hospital of Chongqing Medical University from July 2019 to January 2021 were collected.Simple random grouping was performed by computer,with 49 cases as observation subjects,and 15 patients for diagnostic test.According to clinical activity score(CAS),49 GO patients were divided into active group(CAS≥3 points,48 eyes)and inactive group(CAS<3 points,50 eyes).Normal control group(NC group)included 31 patients(62 eyes).All subjects underwent 3.0T orbital MRI T2-mapping.Measuring the T2 relaxation time(T2RT)of superior rectus,inferior rectus,medial rectus,and lateral rectus on five layers behind the eyeball on T2-mapping coronal images,and select the maximum value of T2RT in the five layers for each extraocular muscle to represent the T2RT of this extraocular muscle.Finally,select the maximum T2RT values of the four extraocular muscles,expressed as extraocular muscle maximum T2RT.Compare the differences of the above 5 indicators(superior rectus T2RT,inferior rectus T2RT,medial rectus T2RT,lateral rectus T2RT,extraocular muscle maximum T2RT)between active group,inactive group and NC group.ROC curve was used to analyze the diagnostic value of the above 5 indicators for GO activity assessment,and the diagnostic threshold was obtained.Then,another 15 GO patients were performed for diagnostic tests evaluation to determine the indicators of high diagnostic efficacy and the threshold of diagnostic activity.Results The T2RT of all extraocular muscles in active group were significantly higher than those in inactive group and NC group,the difference was statistically significant(P<0.001).The threshold value of the five indicators were obtained by ROC curve analysis.The maximum T2RT cut-off values of superior rectus muscle,inferior rectus muscle,medial rectus muscle,lateral rectus muscle and extraocular muscles for judging activity were 80.200 ms,97.045 ms,94.355 ms,85.750 ms and 101.385 ms respectively.Another 15 GO patients were performed for diagnostic tests,the indexes with relatively high sensitivity,specificity,positive predictive value and negative predictive value were inferior rectus T2RT and extraocular muscle maximum T2RT,the cut-off values of GO activity were 97.045 ms and 101.385 ms,respectively;the sensitivity were 91.7％and 93.8％,respectively;the specificity all were 80.0％.Conclusions MRI T2-mapping sequence has a good value in assessment of GO activity.The inferior rectus T2RT and extraocular muscle maximum T2RT can be choosed to evaluate the activity of GO.

Objective To investigate the environmental contamination related to first patient with carbapenem-re-sistant Acinetobacter baumannii(CRAB)infection and the infection status of relevant patients in a newly established intensive care unit(ICU)of a hospital in Tibetan area,and analyze the transmission risk.Methods From the ad-mission in ICU of a patients who was first detected CRAB on November 15,2021 to the 60th day of hospitalization,all patients who stayed in ICU for＞48 hours were performed active screening on CRAB.On the 30th day and 60th day of the admission to the ICU of the first CRAB-infected patient,environment specimens were taken respectively 2 hours after high-frequency diagnostic and therapeutic activities but before disinfection,and after disinfection but before medical activities.CRAB was cultured with chromogenic culture medium.Results Among the 13 patients who were actively screened,1 case was CRAB positive,he was transferred from the ICU of a tertiary hospital to the ICU of this hospital on November 19th.On the 40th day of admission to the ICU,he had fever,increased frequency for sputum suction,and CRAB was detected.The drug sensitivity spectrum was similar to that of the first case,and he also stayed in the adjacent bed of the first case.64 environmental specimens were taken,and 9 were positive for CRAB,with a positive rate of 14.06％,8 sampling points such as the washbasin,door handle and bed rail were positive for CRAB after high-frequency diagnostic and therapeutic activities.After routine disinfection,CRAB was detected from the sink of the washbasin.Conclusion For the prevention and control of CRAB in the basic-level ICU in ethnic areas,it is feasible to conduct risk assessment on admitted patients and adopt bundled prevention and con-trol measures for high-risk patients upon admission.Attention should be paid to the contaminated areas(such as washbasin,door handle,and bed rail)as well as the effectiveness of disinfection of sink of washbasin.

This paper outlines the common aspects of constructing integrated urban medical groups,focusing on governance,organizational restructuring,operational modes,and mechanism synergy.It then delves into the challenges in China's group construction,highlighting issues with power-responsibility alignment,capacity evolution,incentive alignment,and performance evaluation.Finally,the paper suggests strategies to enhance China's compact urban medical groups,focusing on governance reform,capacity building,benefit integration,and performance evaluation.

Objective To investigate the impact of silymarin(SM)on the malignant growth of glioma cells and the regulatory mechanism on the miR-124-3p/WEE1 axis.Methods Glioma U87 cells were grouped into control,SM low,medium,and high concentration groups,and SM high concentration + miR-124-3p inhibitor group(SM high + miR-124-3p inhibitor group).CCK-8 was used to measure the proli-feration rate of cells;Transwell? assay was applied to assay the migration and invasion of cells;cell cycle progression was detected by flow cytometry;Western blotting was applied to measure the expression of cyclin D1 and apoptosis-related proteins;the levels of miR-124-3p and WEE1 mRNA were determined by qRT-PCR;and a luciferase activity test was applied to verify the targeting relationship between miR-124-3p and WEE1;in addition,the establishment,administration,and analysis of a NOD/SCID mouse model of intracranial trans-planted tumor were conducted.Results Compared with the control group,the cell proliferation,the numbers of migrating and invading cells,the expression of cyclin D1,and the level of WEE1 mRNA in the various SM treatment groups decreased,the number of cells in G0/G1 phase,the expression of cleaved caspase-8,cleaved caspase-9,cleaved caspase-3 and miR-124-3p increased(P＜0.05);furthermore,transfection of miR-124-3p inhibitor reversed the inhibitory effect of SM on the malignant behavior of glioma cells.In vivo experiments with mice showed that the weights and volumes of tumors in the SM treatment group were lower than those in the model group(P＜0.05),and there was no discernible change in the weight of the mice(P＞0.05).Conclusion SM can inhibit the malignant growth of glioma cells by upregulating miR-124-3p and downregulating WEE1.

DNA origami is a powerful technique for generating nanostructures with dynamic properties and intelligent controllability. The precise geometric shapes, high programmability, and excellent biocompatibility make DNA origami nanostructures an emerging drug delivery vehicle. The shape, size of the carrier material, as well as the loading and release of drugs are important factors affecting the bioavailability of drugs. This paper focuses on the controllable design of DNA origami nanostructures, efficient drug loading, and intelligent drug release. It summarizes the cutting-edge applications of DNA origami technology in biomedicine, and discusses areas where researchers can contribute to further advancing the clinical application of DNA origami carriers.

Pulmonary fibrosis is a chronic and progressive lung disease that poses a threat to human health. Current treatment options are limited, highlighting the urgent need for more effective therapeutic strategies. Tetrandrine (TET), a bis-benzylisoquinoline alkaloid extracted from Stephania tetrandra, has been known for its anti-inflammatory and anti-fibrotic effects, but its specific mechanisms remain unclear. This study investigated the anti-fibrotic effects of TET in a chronic model of pulmonary fibrosis, aiming to delineate the molecular mechanisms underlying TET-mediated inhibition of fibroblast activation. The results showed that TET significantly alleviated the pathological changes in a murine model of multiple bleomycin-induced pulmonary fibrosis and effectively inhibited TGF-β1-induced fibroblast activation. Mechanistically, TET predominantly inhibited the TGF-β/SMAD signaling pathway and diminished intracellular reactive oxygen species (ROS) levels. Utilizing CRISPR-Cas9 library screening, we identified that angiotensin II type 1 receptor associated protein (AGTRAP) and membrane palmitoylated protein 6 (MPP6) played important roles in TET's suppressive impact of ROS levels, with the knockout of two genes attenuating TET's antifibrotic activity. All animal treatment procedures were approved according to the Committee on the Ethics of Animal Experiments of the Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences (IMB-20230406D507). This research not only elucidates the pharmacological mechanism of TET but also provides a novel therapeutic avenue for the treatment of pulmonary fibrosis.

Objective To explore the mechanical behavior of cancellous bone under the interaction of whole-body low-magnitude high-frequency vibration(LMHFV)parameters,in order to provide theoretical guidance for the clinical treatment of disuse osteoporosis.Methods A three-dimensional reconstruction model was established for the cancellous bone of the mid femur by Mimics software,which was then imported into Comsol software to form a three-dimensional fluid-solid coupling finite element model.Twelve scenarios with the vibration acceleration amplitude(a)being 0.015×g,0.02×g,0.03×g and vibration frequency(f)being 30,45,60 and 100 Hz were set up for the simulation study to analyze the distribution rules of the hydrodynamic microenvironment,the stresses and the deformation displacements of cancellous bone under the interaction of LMHFV parameters.Results The bone marrow flow velocity on the surface of trabeculae and deformation displacement of bone matrix increased with the rising of a and decreased with the growing of f.Trabeculae gained high mean values of deformation displacement in case of the vibration scenario(0.015×g/0.02×g/0.03×g,30 Hz),and had high von Mises stress when LMHFV parameters were restricted within(0.02×g to 0.03×g,30 Hz to 35 Hz).Conclusion Whole-body LMHFV significantly improves the force and hydrodynamic environment of cancellous bone,and force-mediated osteoblast bioactivity can be enhanced by rationally modulating LMHFV parameters during clinical processes so as to promote osteogenesis.[Chinese Medical Equipment Journal,2024,45(7):17-23]