1.Preliminary application of histological evaluation of donor pancreas biopsy tissue in simultaneous pancreas-kidney transplantation
Jiao WAN ; Hui GUO ; Jiali FANG ; Guanghui LI ; Luhao LIU ; Yunyi XIONG ; Wei YIN ; Tong YANG ; Junjie MA ; Zheng CHEN
Organ Transplantation 2026;17(2):250-256
Objective To preliminarily investigate the safety and efficacy of donor pancreas needle biopsy in simultaneous pancreas-kidney transplantation. Methods Clinical data of 7 cases undergoing donor pancreas biopsy were collected retrospectively. All cases underwent donor pancreas biopsy before or during simultaneous pancreas-kidney transplantation. Frozen section or paraffin sectioning techniques were used for tissue preparation, and hematoxylin-eosin and Masson staining were performed to histologically evaluate the donor pancreas. The quality of donor pancreas was comprehensively assessed by combining histological findings with the donor's clinical data. Postoperative follow-up data of 5 simultaneous pancreas-kidney transplant recipients were collected to summarize the safety of donor pancreas biopsy and the prognosis of transplant recipients. Results The 7 pancreas donors were aged 28 to 62 years, with a body mass index ranging from 20.76 to 27.68 kg/m2. Liver ultrasound indicated fatty liver in 3 cases, while pancreatic ultrasound did not reveal any significant abnormalities. Among them, biopsy was performed on 2 donors after completion of pancreatic procurement and processing, and the frozen section histology showed moderate acute pancreatitis changes (edema of acinar cells, necrosis and inflammatory cell infiltration). Combined with a serum amylase level elevated more than 3 times the upper limit of normal value, these two donor pancreases were finally discarded. The remaining 5 cases underwent biopsy immediately after pancreatic vascular anastomosis during simultaneous pancreas-kidney transplantation, and histological evaluation was performed on paraffin-embedded sections. No biopsy-related complications (such as bleeding, pancreatic fistula, etc.) occurred after transplantation. One recipient died of severe infection 2 months after transplantation, while the other 4 recipients were followed up for more than 5 years, with well-functioning transplant kidneys and pancreases. Conclusions Donor pancreas biopsy is relatively safe, and the risk of biopsy-related complications after transplantation is controllable. Comprehensive assessment of donor pancreas quality by combining histological evaluation with the donor's clinical indicators is conducive to improving the accuracy of donor pancreas selection and organ utilization.
2.Effect Analysis of Different Interventions to Improve Neuroinflammation in The Treatment of Alzheimer’s Disease
Jiang-Hui SHAN ; Chao-Yang CHU ; Shi-Yu CHEN ; Zhi-Cheng LIN ; Yu-Yu ZHOU ; Tian-Yuan FANG ; Chu-Xia ZHANG ; Biao XIAO ; Kai XIE ; Qing-Juan WANG ; Zhi-Tao LIU ; Li-Ping LI
Progress in Biochemistry and Biophysics 2025;52(2):310-333
Alzheimer’s disease (AD) is a central neurodegenerative disease characterized by progressive cognitive decline and memory impairment in clinical. Currently, there are no effective treatments for AD. In recent years, a variety of therapeutic approaches from different perspectives have been explored to treat AD. Although the drug therapies targeted at the clearance of amyloid β-protein (Aβ) had made a breakthrough in clinical trials, there were associated with adverse events. Neuroinflammation plays a crucial role in the onset and progression of AD. Continuous neuroinflammatory was considered to be the third major pathological feature of AD, which could promote the formation of extracellular amyloid plaques and intracellular neurofibrillary tangles. At the same time, these toxic substances could accelerate the development of neuroinflammation, form a vicious cycle, and exacerbate disease progression. Reducing neuroinflammation could break the feedback loop pattern between neuroinflammation, Aβ plaque deposition and Tau tangles, which might be an effective therapeutic strategy for treating AD. Traditional Chinese herbs such as Polygonum multiflorum and Curcuma were utilized in the treatment of AD due to their ability to mitigate neuroinflammation. Non-steroidal anti-inflammatory drugs such as ibuprofen and indomethacin had been shown to reduce the level of inflammasomes in the body, and taking these drugs was associated with a low incidence of AD. Biosynthetic nanomaterials loaded with oxytocin were demonstrated to have the capability to anti-inflammatory and penetrate the blood-brain barrier effectively, and they played an anti-inflammatory role via sustained-releasing oxytocin in the brain. Transplantation of mesenchymal stem cells could reduce neuroinflammation and inhibit the activation of microglia. The secretion of mesenchymal stem cells could not only improve neuroinflammation, but also exert a multi-target comprehensive therapeutic effect, making it potentially more suitable for the treatment of AD. Enhancing the level of TREM2 in microglial cells using gene editing technologies, or application of TREM2 antibodies such as Ab-T1, hT2AB could improve microglial cell function and reduce the level of neuroinflammation, which might be a potential treatment for AD. Probiotic therapy, fecal flora transplantation, antibiotic therapy, and dietary intervention could reshape the composition of the gut microbiota and alleviate neuroinflammation through the gut-brain axis. However, the drugs of sodium oligomannose remain controversial. Both exercise intervention and electromagnetic intervention had the potential to attenuate neuroinflammation, thereby delaying AD process. This article focuses on the role of drug therapy, gene therapy, stem cell therapy, gut microbiota therapy, exercise intervention, and brain stimulation in improving neuroinflammation in recent years, aiming to provide a novel insight for the treatment of AD by intervening neuroinflammation in the future.
3.Nogo-A Protein Mediates Oxidative Stress and Synaptic Damage Induced by High-Altitude Hypoxia in the Rat Hippocampus.
Jin Yu FANG ; Huai Cun LIU ; Yan Fei ZHANG ; Quan Cheng CHENG ; Zi Yuan WANG ; Xuan FANG ; Hui Ru DING ; Wei Guang ZHANG ; Chun Hua CHEN
Biomedical and Environmental Sciences 2025;38(1):79-93
OBJECTIVE:
High-altitude hypoxia exposure often damages hippocampus-dependent learning and memory. Nogo-A is an important axonal growth inhibitory factor. However, its function in high-altitude hypoxia and its mechanism of action remain unclear.
METHODS:
In an in vivo study, a low-pressure oxygen chamber was used to simulate high-altitude hypoxia, and genetic or pharmacological intervention was used to block the Nogo-A/NgR1 signaling pathway. Contextual fear conditioning and Morris water maze behavioral tests were used to assess learning and memory in rats, and synaptic damage in the hippocampus and changes in oxidative stress levels were observed. In vitro, SH-SY5Y cells were used to assess oxidative stress and mitochondrial function with or without Nogo-A knockdown in Oxygen Glucose-Deprivation/Reperfusion (OGD/R) models.
RESULTS:
Exposure to acute high-altitude hypoxia for 3 or 7 days impaired learning and memory in rats, triggered oxidative stress in the hippocampal tissue, and reduced the dendritic spine density of hippocampal neurons. Blocking the Nogo-A/NgR1 pathway ameliorated oxidative stress, synaptic damage, and the learning and memory impairment induced by high-altitude exposure.
CONCLUSION:
Our results demonstrate the detrimental role of Nogo-A protein in mediating learning and memory impairment under high-altitude hypoxia and suggest the potential of the Nogo-A/NgR1 signaling pathway as a crucial therapeutic target for alleviating learning and memory dysfunction induced by high-altitude exposure.
GRAPHICAL ABSTRACT
available in www.besjournal.com.
Animals
;
Oxidative Stress
;
Hippocampus/metabolism*
;
Rats
;
Nogo Proteins/genetics*
;
Male
;
Rats, Sprague-Dawley
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Hypoxia/metabolism*
;
Altitude
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Synapses
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Humans
;
Altitude Sickness/metabolism*
4.Association of Body Mass Index with All-Cause Mortality and Cause-Specific Mortality in Rural China: 10-Year Follow-up of a Population-Based Multicenter Prospective Study.
Juan Juan HUANG ; Yuan Zhi DI ; Ling Yu SHEN ; Jian Guo LIANG ; Jiang DU ; Xue Fang CAO ; Wei Tao DUAN ; Ai Wei HE ; Jun LIANG ; Li Mei ZHU ; Zi Sen LIU ; Fang LIU ; Shu Min YANG ; Zu Hui XU ; Cheng CHEN ; Bin ZHANG ; Jiao Xia YAN ; Yan Chun LIANG ; Rong LIU ; Tao ZHU ; Hong Zhi LI ; Fei SHEN ; Bo Xuan FENG ; Yi Jun HE ; Zi Han LI ; Ya Qi ZHAO ; Tong Lei GUO ; Li Qiong BAI ; Wei LU ; Qi JIN ; Lei GAO ; He Nan XIN
Biomedical and Environmental Sciences 2025;38(10):1179-1193
OBJECTIVE:
This study aimed to explore the association between body mass index (BMI) and mortality based on the 10-year population-based multicenter prospective study.
METHODS:
A general population-based multicenter prospective study was conducted at four sites in rural China between 2013 and 2023. Multivariate Cox proportional hazards models and restricted cubic spline analyses were used to assess the association between BMI and mortality. Stratified analyses were performed based on the individual characteristics of the participants.
RESULTS:
Overall, 19,107 participants with a sum of 163,095 person-years were included and 1,910 participants died. The underweight (< 18.5 kg/m 2) presented an increase in all-cause mortality (adjusted hazards ratio [ aHR] = 2.00, 95% confidence interval [ CI]: 1.66-2.41), while overweight (≥ 24.0 to < 28.0 kg/m 2) and obesity (≥ 28.0 kg/m 2) presented a decrease with an aHR of 0.61 (95% CI: 0.52-0.73) and 0.51 (95% CI: 0.37-0.70), respectively. Overweight ( aHR = 0.76, 95% CI: 0.67-0.86) and mild obesity ( aHR = 0.72, 95% CI: 0.59-0.87) had a positive impact on mortality in people older than 60 years. All-cause mortality decreased rapidly until reaching a BMI of 25.7 kg/m 2 ( aHR = 0.95, 95% CI: 0.92-0.98) and increased slightly above that value, indicating a U-shaped association. The beneficial impact of being overweight on mortality was robust in most subgroups and sensitivity analyses.
CONCLUSION
This study provides additional evidence that overweight and mild obesity may be inversely related to the risk of death in individuals older than 60 years. Therefore, it is essential to consider age differences when formulating health and weight management strategies.
Humans
;
Body Mass Index
;
China/epidemiology*
;
Male
;
Female
;
Middle Aged
;
Prospective Studies
;
Rural Population/statistics & numerical data*
;
Aged
;
Follow-Up Studies
;
Adult
;
Mortality
;
Cause of Death
;
Obesity/mortality*
;
Overweight/mortality*
5.Preservation and Utilization of Clinical Bronchoalveolar Lavage Fluid Specimen
Hui ZHANG ; Le LI ; Yun FANG ; Ning YANG ; Xin YUAN ; Yan LIU
Medical Journal of Peking Union Medical College Hospital 2025;16(6):1587-1592
Bronchoalveolar lavage fluid (BALF) is rich in various bioactive substances such as cytokines and enzymes, making it a high-quality clinical specimen and research sample. It holds significant value in fields such as etiological analysis, proteomics, pathology, and disease diagnosis and treatment. This article systematically reviews the key technical points for the preservation of BALF samples and provides an in-depth interpretation of bronchoalveolar lavage fluid from an application perspective. The aim is to offer references for the standardization of sample preservation practices and to promote the widespread use of BALF samples in clinical research.
6.Recommendations for the clinical use of anti-amyloid-β monoclonal antibody for Alzheimer's disease(2025)
Nan ZHI ; Jinwen XIAO ; Rujing REN ; Binyin LI ; Jintao WANG ; Jieli GENG ; Wenwei CAO ; Yaying SONG ; Hualong WANG ; Shuguang CHU ; Guoping PENG ; Jun LIU ; Xiaoyun LIU ; Fang YUAN ; Wen WANG ; Ronghua DOU ; Xia LI ; Ling YUE ; Wenshi WEI ; Xiaoling PAN ; Xiangyang ZHU ; Dian HE ; Weinü FAN ; Jingping SHI ; Nan ZHANG ; Hui ZHAO ; Qin CHEN ; Cuibai WEI ; Xiaochun CHEN ; Gang WANG
Journal of Chongqing Medical University 2025;50(9):1133-1140
In recent years,significant breakthroughs have been achieved in the immunotherapy for Alzheimer's disease.In line with global advancements,two anti-amyloid-β monoclonal antibodies have been approved and successfully launched in China for clinical use.Lecanemab and Donanemab were officially used in June 2024 and April 2025 in China,respectively.In order to standardize the rational and safe application of anti-amyloid-β monoclonal antibodies for Alzheimer's disease in China,this article integrates recom-mendations from the clinical trials and real-world experience from the author's team and domestic peers to further update the recom-mendations for the clinical use of anti-amyloid-β monoclonal antibody based on the 2024 version.It includes indications for therapy,pre-treatment evaluation and preparation,administration protocols and safety measures during treatment,and post-treatment monitor-ing strategies.
7.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.
8.Analysis of influencing factors for ischemic stroke in patients with unilateral moderate-to-severe extracranial internal carotid artery stenosis and development of a nomogram model
Yaqin HUANG ; Yusen LIU ; Jia YANG ; Xinyi CAI ; Qi FANG ; Pinjing HUI
Chinese Journal of Cerebrovascular Diseases 2025;22(6):363-372
Objective To explore the influencing factors for ischemic stroke in patients with unilateral moderate-to-severe extracranial internal carotid artery(ICA)stenosis and to construct a nomogram prediction model.Methods This study retrospectively and consecutively enrolled patients diagnosed with unilateral moderate-to-severe extracranial ICA stenosis and exhibited indications for carotid endarterectomy(CEA)hospitalized in the Department of Neurosurgery at the First Affiliated Hospital of Soochow University,between August 2019 and September 2024.The patients were divided into a stroke group and a non-stroke group,based on their clinical presentation and head MRI results.Baseline characteristics and clinical data including age,sex,body mass index,blood pressure(systolic and diastolic pressure[<140 mmHg,140-<160 mmHg,≥160 mmHg]),hypertension,diabetes,smoking and alcohol consumption history,use of statin and antiplatelet medication,fasting blood glucose,high-density lipoprotein cholesterol(HDL-C),low-density lipoprotein cholesterol(LDL-C),triglycerides(TG),total cholesterol(TC)were collected and ratios between LDL-C/HDL-C,TG/HDL-C,non-HDL-C(calculated according to equation:non-HDL-C=TC-HDL-C),and non-HDL-C/HDL-C(nHHR)were calculated based on aforementioned data.The clinical and baseline data were then compared between two groups.Imaging data included side of carotid artery stenosis(identified through neck vascular ultrasound,CT angiography and/or DSA),degree of carotid stenosis(with 50%-69%categorized as moderate stenosis,and,70%-99%as severe stenosis),plaque echogenicity(predominantly low,medium or high),plaque calcification(surface and basal calcification),plaque ulceration(exists or not),bilateral middle cerebral artery(MCA)hemodynamic parameters measured by transcranial Doppler ultrasound(including,mean flow velocity[Vm],peak systolic velocity[Vs],end-diastolic velocity[Vd]),and the pulsatility index(PI,calculated via formula:PI=[Vs-Vd]/Vm).The hemodynamic parameter differences(△Vm,△Vs,△Vd,△PI)between the healthy and affected MCA were calculated.The baseline,clinical and imaging data with P<0.05 in univariate analysis were included in multivariate Logistic regression analysis using forward stepwise selection to identify influencing factors for ischemic stroke in patients with unilateral moderate-to-severe extracranial ICA stenosis,and a nomogram prediction model was then constructed base on the analyzed results.Receiver operating characteristic curves were plotted,and the area under the curve(AUC)was calculated to evaluate the predictive performance of the nomogram.Delong's test was used to compare AUC differences between single indicators and the combined model.Results A total of 166 patients with unilateral moderate-to-severe extracranial ICA stenosis and CEA indication were included.In which,99 patients were in the stroke group and 67 patients were in the non-stroke group.The stroke group had a significantly higher proportion of hypertension patients(78.8%[78/99]vs.59.7%[40/67],P=0.008),higher systolic blood pressure([152±15]mmHg vs.[137±18]mmHg,P<0.01),higher diastolic blood pressure([84±10]mmHg vs.[80±10]mmHg,P=0.042),higher TG(1.33[0.95,1.77]mmol/L vs.1.10[0.87,1.48]mmol/L,P=0.019),higher TG/HDL-C(1.35[0.97,2.08]vs.1.07[0.81,1.52],P=0.003),and higher nHHR(2.89[2.25,3.61]vs.2.48[1.93,3.27],P=0.027)than the non-stroke group.The HDL-C was significantly lower in the stroke group(0.96[0.80,1.15]mmol/L vs.1.03[0.91,1.16]mmol/L,P=0.014).Statistically significant differences were also observed in the distribution of systolic blood pressure between the groups(P<0.01).No significant differences were found in other clinical data(all P>0.05).The proportion of patients with carotid plaque ulceration was higher in the stroke group(35.4%[35/99]vs.16.4%[11/67],P=0.007),while stenosis side,stenosis degree,plaque echogenicity,and plaque calcification type showed no significant differences between the groups(all P>0.05).△Vm(19[4,32]cm/s vs.10[-3,21]cm/s,P=0.001),△Vs(32[9,55]cm/s vs.24[3,40]cm/s,P=0.005),and △Vd(10[-1,19]cm/s vs.6[-3,12]cm/s,P=0.006)were significantly higher in the stroke group.No significant difference was found in △PI(P=0.076).Multivariate Logistic regression analysis identified high systolic blood pressure(OR,1.063,95%CI 1.036-1.090,P<0.01),high TG/HDL-C(OR,2.802,95%CI 1.551-5.061,P=0.001),high △Vm(OR,1.032,95%CI 1.010-1.055,P=0.004),and plaque ulceration(OR,2.777,95%CI 1.123-6.871,P=0.027)as independent risk factors for ischemic stroke in patients with unilateral moderate-to-severe extracranial ICA stenosis.Systolic blood pressure,TG/HDL-C,△Vm and plaque ulceration were involved in the construction of a combined predictive model for ischemic stroke in the targeted patient group(with unilateral moderate-to-severe extracranial ICA stenosis).The AUC of the combined prediction model was 0.828(95%CI 0.765-0.892,P<0.01),which was significantly higher than the predictive efficacy of any single factor(all P<0.01).Conclusions High systolic blood pressure,high TG/HDL-C ratio,high △Vm,and plaque ulceration are independent risk factors for ischemic stroke in patients with unilateral moderate-to-severe extracranial ICA stenosis.The nomogram prediction model based on these factors demonstrates good predictive value for assessing ischemic stroke risk in this patient population.
9.Relationship between active exercise rehabilitation behavior and symptoms trajectory in middle aged patients with chronic obstructive pulmonary disease
Rong CHENG ; Zhixia ZHANG ; Limin LIU ; Qiuxia CHEN ; Zhen YANG ; Hui WU ; Fang JIANG ; Linru QIAO
Chinese Journal of Nursing 2025;60(16):1996-2002
Objective To explore the temporal characteristics and correlation between active exercise rehabilitation behaviour and related symptoms in middle-aged chronic obstructive pulmonary disease(COPD)patients,and to provide a basis for constructing a full cycle precision rehabilitation management system.Methods The ecological momentary assessment method was used to select 63 middle-aged COPD patients from the respiratory and critical care medicine department of a tertiary comprehensive hospital in Wuhan from October 15 to December 1,2024,using convenience sampling.Their active exercise rehabilitation behaviour(number of exercise projects,duration)and related symptoms(dyspnea,fatigue,anxiety)were continuously monitored for a week by using baseline survey,daily active exercise rehabilitation behavior assessment questionnaire,daily symptom assessment questionnaire.A multi-layer linear model was used to analyze the dynamic correlation between active exercise rehabilitation behaviour and symptoms.Results 58 patients were included.During the 1-week ecological momentary assessment,the system triggered a total of 1,218 momentary assessments and obtained 1,120 valid responses(with the valid response rate of 91.95%),with patients completing an average of(2.76±0.39)assessments per day.Multilevel linear models showed that momentary dyspnoea,fatigue,anxiety symptoms and baseline kinesiophobia all significantly negatively influenced active exercise rehabilitation behaviour(P<0.05).Conclusion There are dynamic changes in the active exercise rehabilitation behaviour and related symptoms of middle-aged COPD patients.Nursing staff should establish a precise rehabilitation intervention system based on symptom fluctuations,strengthen patient self-management efficiency through dynamic monitoring and hierarchical management,and achieve long-term optimization of lung rehabilitation effects.
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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