1.Spatiotemporal Electrical Impedance Tomography for Speech Respiratory Assessment in Cleft Palate: an Interpretable Machine Learning Study
Yang WU ; Xiao-Jing ZHANG ; Hao YU ; Cheng-Hui JIANG ; Bo SUN ; Jia-Feng YAO
Progress in Biochemistry and Biophysics 2026;53(2):485-500
ObjectiveCleft palate (CP) is a common congenital deformity often associated with velopharyngeal insufficiency (VPI), which disrupts the physiological coupling between respiration and speech. Conventional clinical assessments, such as nasometry and spirometry, provide limited static data and fail to visualize the dynamic spatiotemporal distribution of lung ventilation during phonation. This study introduces spatiotemporal electrical impedance tomography (ST-EIT) to evaluate speech-respiratory functional features in CP patients compared to normal controls (NC). The aim is to characterize multi-domain respiratory patterns and to validate an interpretable machine learning framework for providing objective, quantitative evidence for clinical assessment. MethodsSeventy-five participants were enrolled in this study, comprising 37 patients with surgically repaired CP and 38 healthy volunteers matched for age, gender, and body mass index (BMI). All subjects performed standardized sustained phonation tasks while undergoing synchronous monitoring with a 16-electrode EIT system and a pneumotachograph. A comprehensive feature engineering pipeline was developed to extract physiological parameters across 3 complementary domains. (1) Temporal domain: including inspiratory/expiratory phase duration (tPhase), time constants (Tau), and inspiratory-to-expiratory time ratios (TI/TE); (2) airflow domain: comprising mean flow, peak flow, and instantaneous flow at 25%, 50%, and 75% of tidal volume; and (3) spatial domain: quantifying global and regional tidal impedance variation (TIV), global inhomogeneity (GI), and center of ventilation (CoV). Extreme Gradient Boosting (XGBoost) classifiers were trained using 5 distinct data sources (Spirometry, Nasometry, Inspiratory-EIT, Expiratory-EIT, and fused ST-EIT). Model performance was rigorously evaluated via stratified 5-fold cross-validation, and Shapley additive explanations (SHAP) were employed to quantify global and local feature contributions. ResultsThe CP group exhibited a distinct respiratory phenotype compared to controls. In the temporal domain, CP patients showed significantly shorter inspiratory (1.60 s vs.1.85 s, P<0.001) and expiratory phase durations (2.45 s vs. 3.95 s, P<0.001), indicating a rapid, shallow breathing rhythm. In the airflow domain, while inspiratory flows were comparable, the CP group demonstrated significantly elevated mean and peak flows during the expiratory phase (P<0.001), reflecting compensatory respiratory effort. Spatially, CP patients presented significant ventilation redistribution, characterized by higher regional TIV in the right-anterior (ROI1) and left-posterior (ROI4) quadrants, but lower TIV in the left-anterior (ROI2) quadrant. In terms of diagnostic accuracy, the multi-modal ST-EIT model achieved the highest performance (AUC: 0.915±0.012, Accuracy: 0.843±0.019, F1-score: 0.872±0.017), substantially outperforming models based on spirometry (AUC: 0.721) or nasometry (AUC: 0.625) alone. Interpretability analysis revealed that spatial domain features were the most critical, contributing 53.4% to the model’s decision-making, followed by temporal (25.0%) and airflow (21.6%) features. ConclusionST-EIT successfully captures the temporal, airflow, and spatial deviations in CP speech respiration that are undetectable by conventional methods—specifically, rapid phase transitions, hyperdynamic expiratory airflow, and regional ventilation heterogeneity. This study validates ST-EIT as a robust, non-invasive, and radiation-free tool for characterizing speech-respiratory dysfunction, offering high clinical value for bedside screening, rehabilitation planning, and longitudinal monitoring of patients with cleft palate.
2.Spatiotemporal Electrical Impedance Tomography for Speech Respiratory Assessment in Cleft Palate: an Interpretable Machine Learning Study
Yang WU ; Xiao-Jing ZHANG ; Hao YU ; Cheng-Hui JIANG ; Bo SUN ; Jia-Feng YAO
Progress in Biochemistry and Biophysics 2026;53(2):485-500
ObjectiveCleft palate (CP) is a common congenital deformity often associated with velopharyngeal insufficiency (VPI), which disrupts the physiological coupling between respiration and speech. Conventional clinical assessments, such as nasometry and spirometry, provide limited static data and fail to visualize the dynamic spatiotemporal distribution of lung ventilation during phonation. This study introduces spatiotemporal electrical impedance tomography (ST-EIT) to evaluate speech-respiratory functional features in CP patients compared to normal controls (NC). The aim is to characterize multi-domain respiratory patterns and to validate an interpretable machine learning framework for providing objective, quantitative evidence for clinical assessment. MethodsSeventy-five participants were enrolled in this study, comprising 37 patients with surgically repaired CP and 38 healthy volunteers matched for age, gender, and body mass index (BMI). All subjects performed standardized sustained phonation tasks while undergoing synchronous monitoring with a 16-electrode EIT system and a pneumotachograph. A comprehensive feature engineering pipeline was developed to extract physiological parameters across 3 complementary domains. (1) Temporal domain: including inspiratory/expiratory phase duration (tPhase), time constants (Tau), and inspiratory-to-expiratory time ratios (TI/TE); (2) airflow domain: comprising mean flow, peak flow, and instantaneous flow at 25%, 50%, and 75% of tidal volume; and (3) spatial domain: quantifying global and regional tidal impedance variation (TIV), global inhomogeneity (GI), and center of ventilation (CoV). Extreme Gradient Boosting (XGBoost) classifiers were trained using 5 distinct data sources (Spirometry, Nasometry, Inspiratory-EIT, Expiratory-EIT, and fused ST-EIT). Model performance was rigorously evaluated via stratified 5-fold cross-validation, and Shapley additive explanations (SHAP) were employed to quantify global and local feature contributions. ResultsThe CP group exhibited a distinct respiratory phenotype compared to controls. In the temporal domain, CP patients showed significantly shorter inspiratory (1.60 s vs.1.85 s, P<0.001) and expiratory phase durations (2.45 s vs. 3.95 s, P<0.001), indicating a rapid, shallow breathing rhythm. In the airflow domain, while inspiratory flows were comparable, the CP group demonstrated significantly elevated mean and peak flows during the expiratory phase (P<0.001), reflecting compensatory respiratory effort. Spatially, CP patients presented significant ventilation redistribution, characterized by higher regional TIV in the right-anterior (ROI1) and left-posterior (ROI4) quadrants, but lower TIV in the left-anterior (ROI2) quadrant. In terms of diagnostic accuracy, the multi-modal ST-EIT model achieved the highest performance (AUC: 0.915±0.012, Accuracy: 0.843±0.019, F1-score: 0.872±0.017), substantially outperforming models based on spirometry (AUC: 0.721) or nasometry (AUC: 0.625) alone. Interpretability analysis revealed that spatial domain features were the most critical, contributing 53.4% to the model’s decision-making, followed by temporal (25.0%) and airflow (21.6%) features. ConclusionST-EIT successfully captures the temporal, airflow, and spatial deviations in CP speech respiration that are undetectable by conventional methods—specifically, rapid phase transitions, hyperdynamic expiratory airflow, and regional ventilation heterogeneity. This study validates ST-EIT as a robust, non-invasive, and radiation-free tool for characterizing speech-respiratory dysfunction, offering high clinical value for bedside screening, rehabilitation planning, and longitudinal monitoring of patients with cleft palate.
3.Celastrol directly targets LRP1 to inhibit fibroblast-macrophage crosstalk and ameliorates psoriasis progression.
Yuyu ZHU ; Lixin ZHAO ; Wei YAN ; Hongyue MA ; Wanjun ZHAO ; Jiao QU ; Wei ZHENG ; Chenyang ZHANG ; Haojie DU ; Meng YU ; Ning WAN ; Hui YE ; Yicheng XIE ; Bowen KE ; Qiang XU ; Haiyan SUN ; Yang SUN ; Zijun OUYANG
Acta Pharmaceutica Sinica B 2025;15(2):876-891
Psoriasis is an incurable chronic inflammatory disease that requires new interventions. Here, we found that fibroblasts exacerbate psoriasis progression by promoting macrophage recruitment via CCL2 secretion by single-cell multi-omics analysis. The natural small molecule celastrol was screened to interfere with the secretion of CCL2 by fibroblasts and improve the psoriasis-like symptoms in both murine and cynomolgus monkey models. Mechanistically, celastrol directly bound to the low-density lipoprotein receptor-related protein 1 (LRP1) β-chain and abolished its binding to the transcription factor c-Jun in the nucleus, which in turn inhibited CCL2 production by skin fibroblasts, blocked fibroblast-macrophage crosstalk, and ameliorated psoriasis progression. Notably, fibroblast-specific LRP1 knockout mice exhibited a significant reduction in psoriasis like inflammation. Taken together, from clinical samples and combined with various mouse models, we revealed the pathogenesis of psoriasis from the perspective of fibroblast-macrophage crosstalk, and provided a foundation for LRP1 as a novel potential target for psoriasis treatment.
4.Research progress on cell mechanics and extracellular matrix mechanics in tumor therapy
ZHANG Hui ; GAO Hui ; XIE Youxiang ; YU Dongsheng
Journal of Prevention and Treatment for Stomatological Diseases 2025;33(10):896-907
During tumor progression, the mechanical properties of the tumor microenvironment play a pivotal regulatory role. As core mechanical indicators, cellular stiffness and extracellular matrix stiffness profoundly influence tumor development through multiple pathways, including cytoskeletal remodeling, activation of signaling pathways, and metabolic regulation. Studies have demonstrated that the tissue stiffness of various solid tumors is significantly higher than that of corresponding normal tissues, while their cellular stiffness exhibits the opposite trend. This mechanical characteristic is also observed in oral squamous cell carcinoma and exerts crucial regulatory effects during tumor progression. This review systematically summarizes the molecular composition and regulatory mechanisms underlying the stiffness of tumor cells and extracellular matrix (ECM). Mainstream stiffness detection technologies such as atomic force microscopy, microfluidic deformation, and real-time deformability cytometry are outlined, with particular emphasis on their applications and limitations in oncology research. This review comprehensively analyzes how mechanical properties regulate key processes in tumor progression, including growth, proliferation, invasion, metastasis, angiogenesis, lymphangiogenesis, drug resistance, and immune escape. This review synthesizes biomechanics-based therapeutic strategies, including: ① targeting the regulation of tumor cell stiffness through cytoskeletal modulators and cholesterol-depleting agents to enhance immune responses; ② reducing ECM stiffness by matrix remodeling enzyme inhibitors, ECM component modulators, or receptor antagonists to improve drug delivery efficiency, and combining with immunotherapy or photothermal therapy for enhanced therapeutic effects; ③ enhancing the mechanical adaptability and anti-tumor activity of immune cells through pharmacological or genetic approaches. This review establishes a robust conceptual framework for developing novel anti-tumor therapeutic strategies and provides insights for future clinical management of oral squamous cell carcinoma.
5.Effect of Tongdu Tiaoshen acupuncture on hippocampal neuronal ferroptosis in depression rats based on SLC7A11/GPX4 pathway.
Tingting QIAN ; Ling ZOU ; Zhi GAO ; Yu WU ; Yanbiao ZHAO ; Nan LI ; Hui LIU ; Meixiang SUN ; Peiyang SUN
Chinese Acupuncture & Moxibustion 2025;45(8):1120-1127
OBJECTIVE:
To observe the effects of Tongdu Tiaoshen acupuncture (acupuncture for unblocking the obstruction in the governor vessel and regulating the spirit) on the depression-like behavior and the hippocampal neuronal ferroptosis mediated by solute carrier family 7 member 11 (SLC7A11)/glutathione peroxidase 4 (GPX4) pathway in depression rats, and explore the mechanism of this therapy for depression.
METHODS:
Of 30 male SD rats of SPF grade, 24 rats were selected. According to the random number table, they were divided into a normal group (n=8) and a modeling group (n=16). The rats in the modeling group were subjected to chronic unpredictable mild stress (CUMS) for 28 consecutive days to establish depression model. After modeling, 16 successfully-modeled rats were randomly divided into a model group and an acupuncture group, 8 rats in each one. In the acupuncture group, Tongdu Tiaoshen acupuncture was applied to "Dazhui"(GV14), "Shuigou" (GV26), "Baihui" (GV20) and "Shenting" (GV24). This intervention measure was deliveredonce a day, continuously for 6 days. The intervention discontinued on day 7, and was completed in 4 weeks. Before and after modeling, and after intervention completion, the behavioristics detection was performed using sucrose preference experiment and open field experiment. After intervention, using hematoxylin-eosin (HE) and Nissl staining, the morphology of hippocampal neurons was observed; with Western blot method, the protein expression of GPX4, SLC7A11, Ferritin and acyl-CoA synthetase long-chain family 4 (ACSL4) in hippocampal tissues was detected; with the real-time fluorescence quantitative PCR adopted, the mRNA expression of GPX4, SLC7A11, Ferritin and ACSL4 was detected; and using colorimetry, the hippocampal iron content was determined.
RESULTS:
After modeling, the sucrose preference rates, the total distance of movement, the standing times and the boxes of horizontal crossing in the model group and the acupuncture group were lower than those in the normal group (P<0.01). After the intervention, the sucrose preference rates, the total distance of movement, the standing times and the boxes of horizontal crossing in the acupuncture group were higher than those in the model group (P<0.01, P<0.05). Compared with the normal group, the number of necrotic cells increased and the number of Nissl bodies decreased in the model group; and when compared with the model group, the neuronal pyknosis and necrosis were ameliorated, the cells were arranged more regularly, the neuronal structure was clear, the matrix was dense, the blood vessels were enriched and the number of Nissl bodies increased in the acupuncture group. In comparison with the normal group, the relative expression of protein and mRNA of hippocampal GPX4, SLC7A11 decreased (P<0.01), it increased in the expression of hippocampal Ferritin and ACSL4 (P<0.01) in the model group. When compared with the model group, in the acupuncture group, the relative expression of protein and mRNA of hippocampal GPX4, SLC7A11 was elevated (P<0.01, P<0.05), it was dropped for hippocampal Ferritin and ACSL4 (P<0.01). In the model group, the hippocampal iron content was elevated when compared with that in the normal group (P<0.01); and it was reduced in the acupuncture group when compared with that in the model group (P<0.05).
CONCLUSION
Tongdu Tiaoshen acupuncture attenuates depression-like behaviors in the depression rats, which may be related to regulating SLC7A11/GPX4 pathway and inhibiting neuronal ferroptosis in the hippocampus.
Animals
;
Ferroptosis
;
Male
;
Hippocampus/cytology*
;
Rats, Sprague-Dawley
;
Rats
;
Depression/enzymology*
;
Phospholipid Hydroperoxide Glutathione Peroxidase/genetics*
;
Acupuncture Therapy
;
Neurons/metabolism*
;
Humans
;
Acupuncture Points
;
Amino Acid Transport System y+/genetics*
;
Glutathione Peroxidase/genetics*
6.Construction of Tax-PC/SDC/PVP-K30 micelles and their protective effect on alcoholic liver injury
Shi-yu ZHANG ; Jing-meng SUN ; Dong-dong LI ; Xin ZHANG ; Jia-hui ZHANG ; Wei-yu ZHANG
Acta Pharmaceutica Sinica 2025;60(2):488-497
Taxifolin (Tax) has been proved to be a medicinal edible substance with protective effects against alcoholic liver injury, however, its poor hydrophilicity and permeability have hindered the clinical application of Tax. In this study, we prepared taxifolin-phosphatidylcholine/sodium deoxycholate/PVP-K30 micells (Tax-MLs). Box-Behnken test was used to obtain the optimal preparation process, and Tax-MLs were characterised by transmission electron microscopy and fourier transform infrared spectroscopy. Physicochemical parameters such as proximate micelle concentration, equilibrium solubility and oil-water partition coefficient were determined, and the release pattern of Tax-MLs was investigated by
7.Construction of a machine learning model based on the Ki67 positive index to predict the recurrence risk of hepatocellular carcinoma
Haoran LI ; Yan YU ; Fangying FAN ; Wenzhen DING ; Hui FENG ; Minghua YING ; Jiawei LI ; Qingqing SUN ; Lele BIAN ; Haokai XU ; Zhanyue CHEN ; Jie YU ; Ping LIANG
Chinese Journal of Hepatology 2025;33(9):898-909
Objective:To screen the optimal machine learning model for predicting the recurrence condition of hepatocellular carcinoma (HCC) at different time points post-surgery, based on the cutoff value of the Ki67 positive proliferation index condition calculated from recurrence-free survival and combined with various clinical features.Methods:retrospective study included initially treated patients with solitary HCC who underwent radical surgery at the Fifth Medical Center of the PLA General Hospital from January 2013 to March 2023. Data included general clinical data, preoperative laboratory parameters, and surgical pathology information about the subjects. The postoperative recurrence status was assessed by querying the medical record system or by telephone follow-up. The Ki67 positive index cutoff value was determined by the X-tile software based on the patient's recurrence-free survival status and time analysis. Survival rates were calculated using the Kaplan-Meier method, and survival curves were plotted. The study population was randomly divided into training and testing groups in a 7:3 ratio using a computer-generated random number method. The minimum redundancy maximum relevance (mRMR) method was used for feature variable selection. Predictive models for postoperative HCC recurrence conditions in patients with HCC were constructed using random forest, support vector machine, logistic regression, and gradient boosting decision tree machine learning algorithms. Inter-group comparisons for continuous data were performed using the t-test or Mann-Whitney U test. Inter-group comparisons of enumeration data were performed using the Pearson χ2 test, continuity-corrected χ2 test, or Fisher's exact test. Results:The cutoff values for the Ki67 positivity index were 0.3 and 0.5 in 510 cases, with a follow-up time ranging from 1.2 to 11.4 years (median: 6.2 years). The recurrence-free survival time was between 1 and 135 months (median: 32 months), with recurrence-free survival rates post-surgery at 1, 2, 3, and 5 years were 87.5%, 77.1%, 61.2%, and 54.5%, respectively. The top five variables predicted HCC recurrence and non-recurrence conditions following surgical follow-up at 6 months, 1 year, 2 years, and beyond 2 years, in accordance with information obtained by the mRMR screen out. The Ki67 positivity index screened a successfully constructed machine learning model to predict HCC recurrence and non-recurrence conditions following surgical follow-up at 6 months, 1 year, 2 years, and beyond 2 years. The machine learning model based on the gradient boosting decision tree algorithm had the best prediction performance among them (areas under the receiver operating characteristic curves for predicting HCC recurrence within six months in the training and validation sets were 0.996 and 0.946, and accuracies were 0.972 and 0.935, respectively).Conclusion:A machine learning model was successfully constructed using the Ki67 positivity index combined with four readily available clinical features to predict HCC recurrence. The machine learning model based on the gradient boosting decision tree algorithm demonstrated the best performance in terms of predicting HCC recurrence within six months after surgery.
8.Ameliorating effect of total flavonoids of rhododendron on brain oxi-dative stress injury in cerebral ischemia-reperfusion rats
Xiaohai YU ; Yu JIN ; Minqiong SUN ; Hui CONG ; Qianying GUO
Chinese Journal of Clinical Pharmacology and Therapeutics 2025;30(2):216-221
AIM:To explore the protective effect of total flavonoids from rhododendron(TFR)on oxi-dative stress injury in the brain of rats subjected to cerebral ischemia/reperfusion(I/R).METHODS:For-ty male SD rats were randomly divided into 5 groups:sham operation group(Sham group),cere-bral ischemia-reperfusion group(MCAO group),and Cerebral Ischemia/Reperfusion with TFR treat-ment groups(TFR 50,100,200 mg/kg groups).The MCAO group and TFR-treated groups underwent ischemia/reperfusion surgery,and the TFR-treated groups received TFR intragastrically for 14 consecu-tive days following the ischemia/reperfusion injury.After 14 days,comparisons were made in terms of neurological function scores,serum inflammatory factors,oxidative stress indicators,and brain injury markers.Additionally,histological examination of brain tissue morphology using Hematoxylin and Eo-sin(HE)staining,observation of cerebral blood flow through cerebral blood flow imaging,and measurement of lactate dehydrogenase(LDH),neu-ron-specific enolase(NSE)activity in serum,inter-leukin-1(IL-1),interleukin-6(IL-6)levels,superox-ide dismutase(SOD)activity,malondialdehyde(MDA)content,nitric oxide(NO)content,and nitric oxide synthase(NOS)activity were performed.RE-SULTS:Compared to the Sham group,MCAO rats exhibited abnormal neurological function scores,severe damage to the microstructure of brain tis-sue,noticeable changes in brain morphology,ele-vated activities of LDH and NSE,increased levels of IL-1 and IL-6,elevated MDA content,and de-creased SOD,NOS activity,and NO content.In com-parison to the MCAO group,rats treated with TFR at doses of 50,100,and 200 mg/kg showed recov-ery of abnormal neurological function scores,re-duced damage to the microstructure of brain tis-sue,decreased activities of LDH and NSE,lowered levels of IL-1 and IL-6,reduced MDA content,and increased SOD,NOS activity,and NO content.CON-CLUSION:Total flavonoids from Rhododendron can protect against cerebral ischemia/reperfusion inju-ry,reducing oxidative stress levels.
9.Changing resistance profiles of Haemophilus influenzae and Moraxella catarrhalis isolates in hospitals across China:results from the CHINET Antimicrobial Resistance Surveillance Program,2015-2021
Hui FAN ; Chunhong SHAO ; Jia WANG ; Yang YANG ; Fupin HU ; Demei ZHU ; Yunsheng CHEN ; Qing MENG ; Hong ZHANG ; Chun WANG ; Fang DONG ; Wenqi SONG ; Kaizhen WEN ; Yirong ZHANG ; Chuanqing WANG ; Pan FU ; Chao ZHUO ; Danhong SU ; Jiangwei KE ; Shuping ZHOU ; Hua ZHANG ; Fangfang HU ; Mei KANG ; Chao HE ; Hua YU ; Xiangning HUANG ; Yingchun XU ; Xiaojiang ZHANG ; Wenen LIU ; Yanming LI ; Lei ZHU ; Jinhua MENG ; Shifu WANG ; Bin SHAN ; Yan DU ; Wei JIA ; Gang LI ; Jiao FENG ; Ping GONG ; Miao SONG ; Lianhua WEI ; Xin WANG ; Ruizhong WANG ; Hua FANG ; Sufang GUO ; Yanyan WANG ; Dawen GUO ; Jinying ZHAO ; Lixia ZHANG ; Juan MA ; Han SHEN ; Wanqing ZHOU ; Ruyi GUO ; Yan ZHU ; Jinsong WU ; Yuemei LU ; Yuxing NI ; Jingrong SUN ; Xiaobo MA ; Yanqing ZHENG ; Yunsong YU ; Jie LIN ; Ziyong SUN ; Zhongju CHEN ; Zhidong HU ; Jin LI ; Fengbo ZHANG ; Ping JI ; Yunjian HU ; Xiaoman AI ; Jinju DUAN ; Jianbang KANG ; Xuefei HU ; Xuesong XU ; Chao YAN ; Yi LI ; Shanmei WANG ; Hongqin GU ; Yuanhong XU ; Ying HUANG ; Yunzhuo CHU ; Sufei TIAN ; Jihong LI ; Bixia YU ; Cunshan KOU ; Jilu SHEN ; Wenhui HUANG ; Xiuli YANG ; Likang ZHU ; Lin JIANG ; Wen HE ; Chunlei YUE
Chinese Journal of Infection and Chemotherapy 2025;25(1):30-38
Objective To investigate the distribution and antimicrobial resistance profiles of clinically isolated Haemophilus influenzae and Moraxella catarrhalis in hospitals across China from 2015 to 2021,and provide evidence for rational use of antimicrobial agents.Methods Data of H.influenzae and M.catarrhalis strains isolated from 2015 to 2021 in CHINET program were collected for analysis,and antimicrobial susceptibility testing was performed by disc diffusion method or automated systems according to the uniform protocol of CHINET.The results were interpreted according to the CLSI breakpoints in 2022.Beta-lactamases was detected by using nitrocefin disk.Results From 2015 to 2021,a total of 43 642 strains of Haemophilus species were isolated,accounting for 2.91%of the total clinical isolates and 4.07%of Gram-negative bacteria in CHINET program.Among the 40 437 strains of H.influenzae,66.89%were isolated from children and 33.11%were isolated from adults.More than 90%of the H.influenzae strains were isolated from respiratory tract specimens.The prevalence of β-lactamase was 53.79%in H.influenzae strains.The H.influenzae strains isolated from children showed higher resistance rate than the strains isolated from adults.Overall,779 strains of H.influenzae did not produce β-lactamase but were resistant to ampicillin(BLNAR).Beta-lactamase-producing strains showed significantly higher resistance rates to these antimicrobial agents than the β-lactamase-nonproducing strains.Of the 16 191 M.catarrhalis strains,80.06%were isolated from children and 19.94%isolated from adults.M.catarrhalis strains were mostly susceptible to both amoxicillin-clavulanic acid and cefuroxime,evidenced by resistance rate lower than 2.0%.Conclusions The emergence of antibiotic-resistant H.influenzae due to β-lactamase production poses a challenge for clinical anti-infective treatment.Therefore,it is very important to implement antibiotic resistance surveillance for H.influenzae and guide rational antibiotic use.All local clinical microbiology laboratories should actively improve antibiotic susceptibility testing and strengthen antibiotic resistance surveillance for H.influenzae.
10.Study on the correlation between H3N2 subtype influenza virus F195Y mutation and inadaptability in chicken embryos
Shunwu HUANG ; Jinyu DUAN ; Shiyu QI ; Hui LIU ; Ying SUN ; Weihua WU ; Xin WANG ; Yu′e HAO ; Shumei ZOU ; Dayan WANG ; Shisong FANG
Chinese Journal of Experimental and Clinical Virology 2025;39(2):175-181
Objective:This study aimed to explore the molecular mechanisms of the maladaptation of H3N2 influenza virus in chicken embryos, provide a theoretical basis for the restoration of H3N2 influenza vaccine production in chicken embryos.Methods:Samples of respiratory secretions from patients with influenza-like symptoms (Influenza-like Illness, ILI) caused by H3N2 influenza virus were inoculated into chicken embryos and Madin-Darby Canine Kidney cells (MDCK), respectively. After isolating the virus, hemagglutination experiments were conducted to detect hemagglutination titers and hemagglutination inhibition experiments were used to compare antigenic differences; further, whole-genome sequencing of H3N2 influenza virus was performed using second-generation high-throughput gene sequencing (Next Generation High-Throughput Gene Sequencing, NGS), and key amino acid sites of mutations were identified through sequence alignment; combined with sialic acid receptor binding experiments, the differences in the binding of wild-type and mutant receptor binding sites (RBS) to sialic acid receptors were compared; finally, molecular docking and molecular dynamics simulation method were used to explore the specific molecular mechanisms of how mutation sites affect the differences in the affinity of the RBS pocket for sialic acid receptors.Results:The hemagglutination assay result indicated that both chicken embryos and MDCK cells could isolate the influenza virus, and the hemagglutination inhibition test showed that no antigenic differences were produced in the isolated strains. NGS analysis revealed that the H3N2 virus underwent an F195Y mutation in the (RBS) region of the hemagglutinin (HA) protein after adaptation through chicken embryo passages. Receptor-binding experiments demonstrated that the F195Y mutation enhanced the virus′s binding ability to α2, 3-linked sialic acid glycan (Neu5Acα2-3Galβ1-4GlcNAcβ-PAA, 3′SLN), while the mutation did not affect the affinity of the RBS pocket for α2, 6-linked sialic acid glycan (Neu5Acα2-6Galβ1-4GlcNAcβ-PAA, 6′SLN). Molecular docking and molecular dynamics simulation result indicate that the F195Y mutation, by replacing a hydrophobic amino acid with a hydrophilic one, leads to a significant decrease in the structure of the RBS pocket, enhancing the binding stability of the H3N2 influenza virus with α2, 3-sln. This is specifically manifested by an increase in binding time and an increase in the number of hydrogen bonds at the RBS site with the receptor. Furthermore, the F195Y mutation does not alter the binding of the virus to other receptors.Conclusions:The F195Y mutation in the RBS pocket of H3N2 influenza virus is a key site affecting the viral chicken embryo inadaptability.


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