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 investigate the predictive value of new simplified insulin resistance(IR)assessment indexes in identifying subclinical left ventricular systolic function impairment in patients with type 2 diabetes mellitus(T2DM).Methods A total of 150 T2DM patients with preserved left ventricular ejection fraction(LVEF≥50%)who were admitted to Department of Endocrinology of the First Affiliated Hospital of Air Force Medical University from June 2021 to December 2021 were retrospectively analyzed.All patients underwent two-dimensional speckle tracking echocardiography to measure left ventricular global longitudinal strain(GLS).According to GLS value,the subjects were divided into the normal group(GLS≥18%group,n=80)and the impaired group(GLS<18%group,n=70).Some new simplified IR assessment indicators were calculated and compared between the two groups,including body mass index(BMI),TG/HDL-C ratio,triglyceride-glucose(TyG)index,TyG-BMI index,TyG-WHR and metabolic score for IR(METS-IR).Correlation between the GLS and the new simplified IR assessment indexes was analyzed.The receiver operating characteristic(ROC)curve was used to analyze the diagnostic efficacy of different simplified IR assessment indexes,with the area under the curve(AUC)calculated.Furthermore,according to whether the subjects were complicated with hypertension,binary logistics regression analysis was performed to explore the independent correlation between the simplified IR assessment index and GLS<18%.Results Total 150 were included with aged(54.5±13.7)years with 96(64.0%)men and 54(36.0%)women.Compared with the GLS≥18%group,the TG/HDL-C ratio,TyG index,TyG-BMI,and METS-IR of subjects in the GLS<18%group were significantly increased(P<0.05).Pearson correlation analysis showed that TG/HDL-C ratio,TyG index,TyG-BMI,TyG-WHR,and METS-IR were negatively correlated with GLS(P<0.05).ROC analysis showed that TyG index had a certain predictive value for the evaluation of GLS<18%(AUC=0.678,95%CI 0.591-0.765,P<0.001).Stratification based on hypertension and further adjusting for confounding factors,TyG index remains significantly associated with GLS<18%(OR=3.249,95%CI 1.045-10.103,P=0.042).Conclusions The novel simplified insulin resistance evaluation indexes are closely associated with left ventricular subclinical systolic dysfunction in T2DM patients with preserved ejection fraction.TyG index is an effective index to identify left ventricular subclinical dysfunction in these populations.

AIM To explore the effect of Heidihuang Pills on renal fibrosis in a rat model of chronic renal failure(CRF)and its mechanism.METHODS Wistar rats were randomly divided into the blank group for normal feeding and the model group for the establishment of CRF rat models by 5/6 nephrectomy.Subsequently,the successfully established rat models were randomly divided into the model group,the Heidihuang Pills group(10.43 g/kg),and the Heidihuang Pills+IGF-1R blocker(JB1)group for a regimen of 7-day subcutaneous injection of 18 μg/kg JB1 followed by gavage of 10.43 g/kg Heidihuang Pills.Eight weeks after the administration,the rats had their serum levels of Scr and BUN detected;their pathological changes of renal tissue observed by HE and Masson staining;their renal protein expressions of TGF-β,HIF-1α and α-SMA detected by immunohistochemistry;their renal protein expressions of IGF-1R and TGF-β detected by Western blot;and their renal mRNA expressions of IGF-1R and TGF-β detected by RT-qPCR.RESULTS Compared with the blank group,the model group displayed increased serum levels of Scr and BUN(P＜0.05);increased,degree of renal fibrosis,and renal fibrosis area(P＜0.05);increased renal expressions of TGF-β,HIF-1α,α-SMA proteins and TGF-β mRNA(P＜0.05);and decreased expressions of IGF-1R mRNA and protein(P＜0.05).Compared with the model group,the Heidihuang Pills group displayed decreased serum Scr and BUN levels(P＜0.05);decreased inflammatory cells in renal interstitium and the fibrosis degree(P＜0.05);decreased renal expressions of TGF-β,HIF-1α,α-SMA proteins and TGF-β mRNA(P＜0.05);and increased expressions of IGF-1R mRNA and protein(P＜0.05).However,the administration of JB1 could weaken the improvement effect of Heidihuang Pills on renal fibrosis in CRF rats(P＜0.05).CONCLUSION Heidihuang Pills can inhibit the renal fibrosis in CRF rats,and the inhibition process is related to up-regulated IGF-1 expression and promoted combination of IGF-1 and IGF-1R.

Tuberous sclerosis complex(TSC)is a rare genetic disease that can lead to benign dysplasia in multiple organs such as the skin, brain, eyes, oral cavity, heart, lungs, kidneys, liver, and bones. Its main symptoms include epilepsy, intellectual disabilities, skin depigmentation, and facial angiofibromas, whilst incidence is approximately 1 in 10 000 to 1 in 6000 newborns. This case presents a middle-aged woman who initially manifested with epilepsy and nodular depigmentation. Later, she developed a lower abdominal mass, elevated creatinine, and severe anemia. Based on clinical features and whole exome sequencing, the primary diagnosis was confirmed as TSC. Laboratory and imaging examinations revealed that the lower abdominal mass originated from the uterus. CT-guided biopsy pathology and surgical pathology suggested a combination of leiomyoma and abscess. With the involvement of multiple organs and various complications beyond the main diagnosis, the diagnostic and therapeutic process for this patient highlights the importance of rigorous clinical thinking and multidisciplinary collaboration in the diagnosis and treatment of rare and challenging diseases.

Most patients with differentiated thyroid cancer have a good prognosis after radioiodine-131 therapy,but a small number of patients are insensitive to radioiodine-131 therapy and even continue to develop disease.At present,some targeted drugs can improve progression-free survival in patients with radioactive iodine-refractory differentiated thyroid cancer(RAIR-DTC),such as sorafenib and levatinib,have been approved for the treatment of RAIR-DTC.However,due to the presence of primary and acquired drug resistance,drug efficacy in these patients is unsatisfactory.This review introduces the acquired drug resistance mechanism of sorafenib in the regulation of mitogen-activated protein kinase(MAPK)and phosphatidylinositol-3-kinase(PI3K)pathways and proposes related treatment strategies,in order to provide a reference for similar drug resistance mechanism of sorafenib and effective treatment of RAIR-DTC.

Objective Human papillomavirus(HPV)is a detriment virus to human health,because it can cause malignant tumors.HPV vaccine has been developed and plays an important role in preventing a range of diseases caused by HPV.HPV vaccine as a primary prevention measure,has demonstrated excellent protective efficacy and safety in preventing HPV-related infection and cervical cancer.This article summarizes the application of preventive HPV vaccine and its safety,and provides reference for the widespread vaccination of HPV vaccine in China.

Transmission electron microscopy(TEM)is considered as an important characterization tool for revealing morphology of materials and an indispensable strategy for studying the mechanisms of charge-discharge process in battery.TEM samples needs be less than 0.1 μm thick,which means electrodeposited materials must undergo pre-treatment processes such as focusing ion beam etching,ultra-thin slicing,or ultrasonic dispersion before they can be observed via TEM.However,such treatments cause structure changes,and what real formed in electrodes is hard to estimate.In this work,a self-interlacing film layer composed of carbon nanotubes(CNTs)was fabricated on a copper grid through blade coating.A novel TEM grid was produced by optimizing the interlacing film's thickness and covering area through adjusting the interlacing state of various concentrations of CNTs.Utilizing the novel TEM grid as the battery's positive electrode,electrode deposits were acquired and subjected to TEM analysis to generate high-definition microstructure images of the electrode surface.This process provided new insights into sample preparation for investigating the deposition/stripping mechanism in high-energy-density metal anodes.

Objective:To explore the value of the imaging nomogram model based on preoperative CT features of patients with small intestinal stromal tumor (SIST) in predicting pathological risk classification.Methods:This was a cohort study. The patients who were diagnosed as primary SIST by postoperative pathology in Cancer Hospital, Chinese Academy of Medical Sciences from January 2014 to October 2023 were retrospectively included. According to the modified 2008 National Institutes of Health classification criteria, the patients were divided into a pathological intermediate/high-risk group (86 cases) and a very low/low-risk group (56 cases). The features of preoperative enhanced CT images of SIST were analyzed, including tumor boundary, necrosis, intra-tumoral hemorrhage, intra-tumoral calcification, growth pattern, enhancement pattern, enhancement degree, enlarged vessels feeding or draining the mass (EVFDM), and tumor location. Patients were followed up to determine the recurrence-free survival (RFS). Univariate and multivariate logistic regression were used to screen the independent predictors of SIST with pathological medium/high-risk group. The independent predictors were combined to construct an imaging prediction model, and a nomogram was drawn. The receiver operating characteristic curve was used to evaluate the predictive efficacy of the model. The Kaplan-Meier method was used to draw the survival curve, and the log-rank test was used to compare the differences in RFS.Results:Univariate logistic regression results showed that tumor shape, necrosis, intra-tumoral hemorrhage, EVFDM, and tumor location were potentially related to medium/high-risk SIST. Multivariate logistic regression results showed that tumor shape ( OR=3.92, 95% CI 1.58-9.71, P=0.003), necrosis ( OR=4.60, 95% CI 1.91-11.09, P<0.001), and EVFDM ( OR=6.25,95% CI 1.74-22.47, P=0.005) were independent predictors of pathological intermediate/high-risk SIST. The area under the curve of the imaging predictive model combining the three predictors to predict the intermediate/high-risk SIST was 0.835 (95% CI 0.769-0.901), the sensitivity was 0.810, the specificity was 0.839, and the accuracy was 0.789. Taking the cut-off value (0.810) as the boundary value, the patients were divided into the high-risk group (74 cases) and the low-risk group (68 cases) according to the prediction results. The median RFS of the predicted high-risk group was poorer than that of the predicted low-risk group, and the difference was statistically significant ( χ2=5.20, P=0.023). Conclusions:The imaging nomogram model based on preoperative CT image features shape, necrosis, and EVFDM can effectively predict the pathological intermediate/high-risk SIST before surgery and has important predictive value for postoperative recurrence.

Pulmonary arterial hypertension(PAH)is a severe disease characterized by abnormal pulmonary vascular remodeling and increased right ventricular pressure load,posing a significant threat to patient health.While some pathological mechanisms of PAH have been revealed,the deeper mechanisms of pathogenesis remain to be elucidated.In recent years,bioinformatics has provided a powerful tool for a deeper understanding of the complex mechanisms of PAH through the integration of techniques such as multi-omics analysis,artificial intelligence,and Mendelian randomization.This review focuses on the bioinformatics methods and technologies used in PAH research,summarizing their current applications in the study of disease mechanisms,diagnosis,and prognosis assessment.Additionally,it analyzes the existing challenges faced by bioinformatics and its potential applications in the clinical and basic research fields of PAH in the future.[Chinese Journal of Contemporary Pediatrics,2024,26(4):425-431]

Objective To investigate the effect of Porphyromonas gingivalis(Pg)infection on immune escape of oesophageal cancer cells and the role of YTHDF2 and Fas in this regulatory mechanism.Methods We examined YTHDF2 and Fas protein expressions in esophageal squamous cell carcinoma(ESCC)tissues with and without Pg infection using immunohistochemistry and in Pg-infected KYSE150 cells using Western blotting.The interaction between YTHDF2 and Fas was investigated by co-immunoprecipitation(Co-IP).Pg-infected KYSE150 cells with lentivirus-mediated YTHDF2 knockdown were examined for changes in expression levels of YTHDF2,cathepsin B(CTSB),Fas and FasL proteins,and the effect of E64(a cathepsin inhibitor)on these proteins were observed.After Pg infection and E64 treatment,KYSE150 cells were co-cultured with human peripheral blood mononuclear cells(PBMCs),and the expressions of T cell-related effector molecules were detected by flow cytometry.Results ESCC tissues and cells with Pg infection showed significantly increased YTHDF2 expression and lowered Fas expression.The results of Co-IP demonstrated a direct interaction between YTHDF2 and Fas.In Pg-infected KYSE150 cells with YTHDF2 knockdown,the expression of CTSB was significantly reduced while Fas and FasL expressions were significantly increased.E64 treatment of KYSE150 cells significantly decreased the expression of CTSB without affecting YTHDF2 expression and obviously increased Fas and FasL expressions.Flow cytometry showed that in Pg-infected KYSE150 cells co-cultured with PBMCs,the expressions of Granzyme B and Ki67 were significantly decreased while PD-1 expression was significantly enhanced.Conclusion Pg infection YTHDF2-dependently regulates the expression of Fas to facilitate immune escape of esophageal cancer and thus promoting cancer progression,suggesting the key role of YTHDF2 in regulating immune escape of esophageal cancer.