1.Effects of human umbilical cord blood platelet-rich plasma,mononuclear cells,and mesenchymal stem cells in repairing thin endometrium in rats
Yanli MU ; Anchun HU ; Wenchi XU ; Panpan CHEN ; Hao CHEN ; Shuyun ZHAO ; Guanyou HUANG ; Xiaojuan CHEN
Chinese Journal of Tissue Engineering Research 2026;30(1):78-92
BACKGROUND:Research has found that human umbilical cord blood platelet rich plasma and human umbilical cord blood derived mesenchymal stem cells have certain therapeutic effects on thin endometrium.However,there are currently no reports on the study of human umbilical cord blood mononuclear cells on thin endometrium,and there is a lack of relevant research comparing the three.OBJECTIVE:To explore the effects and mechanisms of human umbilical cord blood platelet rich plasma,monocytes,and mesenchymal stem cells in repairing thin endometrium in rats.METHODS:Sixty female SPF grade SD rats were randomly divided into sham operation group,model group,human umbilical cord blood platelet rich plasma group,human umbilical cord blood mononuclear cell group,and human umbilical cord blood derived mesenchymal stem cell group,with 12 rats in each group.The sham operation group received 0.5 mL physiological saline injection into the uterine horn,followed by 0.5 mL of PBS infusion after 5 minutes;The model group,human umbilical cord blood platelet rich plasma group,human umbilical cord blood mononuclear cell group,and human umbilical cord blood derived mesenchymal stem cell group were injected with 0.5 mL of 95%ethanol by volume.After 5 minutes,the remaining ethanol was aspirated and washed twice with physiological saline.Then,0.5 mL of PBS,human umbilical cord blood platelet rich plasma,human umbilical cord blood mononuclear cells(1×107 cells/mL),and human umbilical cord blood derived mesenchymal stem cells(1×107 cells/mL)were perfused separately.During the third normal estrus cycle after reperfusion,organs,tissues and serum were collected for testing of relevant indicators.RESULTS AND CONCLUSION:(1)The macroscopic view of uterine tissue,hematoxylin eosin staining and Masson staining results:the sham operation group had intact structure,moderate endometrial thickness,and clear vascular structure.Compared with the sham operation group,the model group showed uterine atrophy,incomplete structure,significantly reduced endometrial thickness and glandular quantity,disordered vascular structure,and increased fibrosis.Compared with the model group,after treatment with human umbilical cord blood derivatives,the size,structure,and endometrial thickness of the uterus were restored(all P<0.01),and fibrosis was reduced,with the most significant recovery observed in the human umbilical cord blood mononuclear cell group.The increase in glandular quantity was most significant in the human umbilical cord blood platelet rich plasma group(P<0.000 1).(2)The immunohistochemistry and immunofluorescence results of uterine tissue showed that compared with the sham operation group,the expression levels of cell proliferation related indicators such as keratin 9 and vimentin,endometrial receptivity related indicators such as leukemia inhibitory factor and integrin αyβ3,platelet endothelial cell adhesion molecule,basic fibroblast growth factor,and vascular endothelial growth factor were all reduced in the model group(all P<0.05).Compared with the model group,the above indicators were significantly increased after treatment with human umbilical cord blood derivatives.Comparison of human umbilical cord blood derivatives among groups showed that keratin 9 and vascular endothelial growth factor protein:human umbilical cord blood mononuclear cell group>human umbilical cord blood derived mesenchymal stem cell group>human umbilical cord blood platelet rich plasma group;Wave shaped protein and leukemia inhibitory factor protein:human umbilical cord blood derived mesenchymal stem cell group>human umbilical cord blood mononuclear cell group>human umbilical cord blood platelet rich plasma group;Integrin αyβ3 protein:human umbilical cord blood platelet rich plasma group>human umbilical cord blood derived mesenchymal stem cell group>human umbilical cord blood mononuclear cell group;Platelet endothelial cell adhesion molecule protein:human umbilical cord blood platelet rich plasma group>human umbilical cord blood mononuclear cell group>human umbilical cord blood derived mesenchymal stem cell group;Basic fibroblast growth factor protein:human umbilical cord blood mononuclear cell group>human umbilical cord blood platelet rich plasma group>human umbilical cord blood derived mesenchymal stem cell group.(3)Western blot analysis showed that compared with the sham operation group,the protein levels of interleukin-6,interleukin-1β,and tumor necrosis factor alpha in the model group were significantly increased(all P<0.001),and their expression levels decreased after treatment(all P<0.05).(4)ELISA assay showed that compared with the sham operation group,the model group had lower levels of anti Mullerian hormone,estradiol,and progesterone,and increased levels of follicle stimulating hormone and luteinizing hormone(except for luteinizing hormone,all P<0.05).After treatment,there was a certain degree of recovery in the levels of sex hormones and anti Mullerian hormones.(5)Fertility experiments showed that compared with the sham operation group,the model group had an increase in conception time and a significant decrease in litter size(all P<0.05).After treatment with human umbilical cord blood derivatives,the litter size of all three groups increased(P<0.05),and no significant differences were found between the groups.This study preliminarily reveals that human umbilical cord blood mononuclear cells have a certain therapeutic effect on thin endometrium,and human umbilical cord blood platelet rich plasma,human umbilical cord blood mononuclear cells,and human umbilical cord blood derived mesenchymal stem cells have different advantages and differences in improving endometrial regeneration function,endometrial receptivity,angiogenesis,inflammation regulation,and improving pregnancy outcomes in thin endometrium.
2.Effects of human umbilical cord blood platelet-rich plasma,mononuclear cells,and mesenchymal stem cells in repairing thin endometrium in rats
Yanli MU ; Anchun HU ; Wenchi XU ; Panpan CHEN ; Hao CHEN ; Shuyun ZHAO ; Guanyou HUANG ; Xiaojuan CHEN
Chinese Journal of Tissue Engineering Research 2026;30(1):78-92
BACKGROUND:Research has found that human umbilical cord blood platelet rich plasma and human umbilical cord blood derived mesenchymal stem cells have certain therapeutic effects on thin endometrium.However,there are currently no reports on the study of human umbilical cord blood mononuclear cells on thin endometrium,and there is a lack of relevant research comparing the three.OBJECTIVE:To explore the effects and mechanisms of human umbilical cord blood platelet rich plasma,monocytes,and mesenchymal stem cells in repairing thin endometrium in rats.METHODS:Sixty female SPF grade SD rats were randomly divided into sham operation group,model group,human umbilical cord blood platelet rich plasma group,human umbilical cord blood mononuclear cell group,and human umbilical cord blood derived mesenchymal stem cell group,with 12 rats in each group.The sham operation group received 0.5 mL physiological saline injection into the uterine horn,followed by 0.5 mL of PBS infusion after 5 minutes;The model group,human umbilical cord blood platelet rich plasma group,human umbilical cord blood mononuclear cell group,and human umbilical cord blood derived mesenchymal stem cell group were injected with 0.5 mL of 95%ethanol by volume.After 5 minutes,the remaining ethanol was aspirated and washed twice with physiological saline.Then,0.5 mL of PBS,human umbilical cord blood platelet rich plasma,human umbilical cord blood mononuclear cells(1×107 cells/mL),and human umbilical cord blood derived mesenchymal stem cells(1×107 cells/mL)were perfused separately.During the third normal estrus cycle after reperfusion,organs,tissues and serum were collected for testing of relevant indicators.RESULTS AND CONCLUSION:(1)The macroscopic view of uterine tissue,hematoxylin eosin staining and Masson staining results:the sham operation group had intact structure,moderate endometrial thickness,and clear vascular structure.Compared with the sham operation group,the model group showed uterine atrophy,incomplete structure,significantly reduced endometrial thickness and glandular quantity,disordered vascular structure,and increased fibrosis.Compared with the model group,after treatment with human umbilical cord blood derivatives,the size,structure,and endometrial thickness of the uterus were restored(all P<0.01),and fibrosis was reduced,with the most significant recovery observed in the human umbilical cord blood mononuclear cell group.The increase in glandular quantity was most significant in the human umbilical cord blood platelet rich plasma group(P<0.000 1).(2)The immunohistochemistry and immunofluorescence results of uterine tissue showed that compared with the sham operation group,the expression levels of cell proliferation related indicators such as keratin 9 and vimentin,endometrial receptivity related indicators such as leukemia inhibitory factor and integrin αyβ3,platelet endothelial cell adhesion molecule,basic fibroblast growth factor,and vascular endothelial growth factor were all reduced in the model group(all P<0.05).Compared with the model group,the above indicators were significantly increased after treatment with human umbilical cord blood derivatives.Comparison of human umbilical cord blood derivatives among groups showed that keratin 9 and vascular endothelial growth factor protein:human umbilical cord blood mononuclear cell group>human umbilical cord blood derived mesenchymal stem cell group>human umbilical cord blood platelet rich plasma group;Wave shaped protein and leukemia inhibitory factor protein:human umbilical cord blood derived mesenchymal stem cell group>human umbilical cord blood mononuclear cell group>human umbilical cord blood platelet rich plasma group;Integrin αyβ3 protein:human umbilical cord blood platelet rich plasma group>human umbilical cord blood derived mesenchymal stem cell group>human umbilical cord blood mononuclear cell group;Platelet endothelial cell adhesion molecule protein:human umbilical cord blood platelet rich plasma group>human umbilical cord blood mononuclear cell group>human umbilical cord blood derived mesenchymal stem cell group;Basic fibroblast growth factor protein:human umbilical cord blood mononuclear cell group>human umbilical cord blood platelet rich plasma group>human umbilical cord blood derived mesenchymal stem cell group.(3)Western blot analysis showed that compared with the sham operation group,the protein levels of interleukin-6,interleukin-1β,and tumor necrosis factor alpha in the model group were significantly increased(all P<0.001),and their expression levels decreased after treatment(all P<0.05).(4)ELISA assay showed that compared with the sham operation group,the model group had lower levels of anti Mullerian hormone,estradiol,and progesterone,and increased levels of follicle stimulating hormone and luteinizing hormone(except for luteinizing hormone,all P<0.05).After treatment,there was a certain degree of recovery in the levels of sex hormones and anti Mullerian hormones.(5)Fertility experiments showed that compared with the sham operation group,the model group had an increase in conception time and a significant decrease in litter size(all P<0.05).After treatment with human umbilical cord blood derivatives,the litter size of all three groups increased(P<0.05),and no significant differences were found between the groups.This study preliminarily reveals that human umbilical cord blood mononuclear cells have a certain therapeutic effect on thin endometrium,and human umbilical cord blood platelet rich plasma,human umbilical cord blood mononuclear cells,and human umbilical cord blood derived mesenchymal stem cells have different advantages and differences in improving endometrial regeneration function,endometrial receptivity,angiogenesis,inflammation regulation,and improving pregnancy outcomes in thin endometrium.
3.Progress of Ground-Glass Nodules and Lung Cancer Evolution: Molecular and Imaging Studies
Jiaxing MU ; Hao LI ; Kezhong CHEN
Medical Journal of Peking Union Medical College Hospital 2026;17(3):607-616
Ground-glass nodules (GGNs) are common imaging manifestation in the early screening of lung adenocarcinoma. With the widespread use of low-dose computed tomography (LDCT) in lung cancer screening, the detection rate of GGNs has significantly increased. According to the presence or absence of a solid component, GGNs are mainly classified into pure ground-glass nodules (pGGNs) and mixed ground-glassnodules (mGGNs), which differ in their natural course and biological behavior. In general, pGGNs tend to progress more slowly, whereas mGGNs are more likely to develop invasive features. The vast majority of pGGNs remain stable for years, but some pGGNs and mGGNs may show an increase in size or in the solid component. The "indolence" observed on the surface of GGNs hides complex genomic, metabolic, and immune changes, which are difficult to capture with traditional image-based data. In recent years, multi-omics analysis, radiomics, and artificial intelligence models have provided new tools for identifying high-risk GGNs. However, there is still controversy over the clinical generalizability, interpretability, and standardization of these models. Furthermore, there is no consensus on whether surgical resection is required. This article reviews the molecular mechanisms, metabolic, and immune microenvironment changes involved in the progression of GGNs, discusses the advantages and limitations of imaging prediction models, and combines domestic and international guidelines and survival studies to explore the controversial points in follow-up and surgical strategies, aiming to provide references for the personalized management of GGNs.
4.Trend change of the mortality and disease burden of hypertensive nephropathy in Chongqing in 2012-2023
Xianbin DING ; Yan JIAO ; Rui DING ; Biao KANG ; Hao MU ; Jie XU ; Ting CHEN ; Jiawei XIE
Journal of Public Health and Preventive Medicine 2025;36(6):43-47
Objective To analyze trend changes of disease burden of hypertensive nephropathy (HTN) between 2012 and 2023 in Chongqing, and to provide the suggestion for HTN prevention and treatment. Methods Death cases of HTN from Chongqing death registration data between 2012 and 2023 were analyzed to calculate indicators such as mortality, age standardization mortality rate (ASMR), rate of years of life lost (YLL) and Average years of life lost. The mortality of HTN between male and female, urban and rural were compared by Chi-square test. The trend change was explained by average annual percent of change (AAPC). Results The mortality and standardized mortality of HTN in Chongqing decreased from 5.44/100 000 and 3.13/100 000 in 2012 to 2.76/100 000 and 1.07/100,000 in 2023 respectively. The average annual percent change (AAPC) was -5.41% and -8.35% respectively, and the differences in the change trends were statistically significant (P<0.01). The mortality and standardized mortality of HTN in males and females decreased with AAPC of 5.50%, 8.07%, 5.27% and 8.69% respectively, and the differences in the change trends were all statistically significant (all P< 0.05). From 2012 to 2014, 2019 and 2021, the mortality rate of HTN in rural areas was higher than that in urban areas (all P < 0.05). The mortality and standardized mortality of HTN in rural areas decreased with AAPC of 6.58% and 9.46% respectively, and the differences in the change trends were all statistically significant (all P<0.05). The rate of YLL and standardized YLL of HTN in Chongqing decreased from 96.02/100 000 and 60.42/100 000 in 2012 to 44.98/100 000 and 21.49/100 000 in 2023 respectively. The AAPC was -5.83% and -7.80% respectively, and the differences in the change trends were statistically significant (both P < 0.05). AYLL of HTN were 17.88 years in 2012, and it was 17.08 years in 2023. There were no statistically significant differences in the changes (both P > 0.05). The standardized AYLL of HTN in rural areas increased at an average annual rate of 1.14%, and the difference was statistically significant (P < 0.05). Conclusion The mortality and YLL rate of HNT in Chongqing was lower than it in China. Moreover, its trend was decreased. It should be strengthened early screening and healthy management of HNT.
5.Exploration of basket trial design with Bayesian method and its application value in traditional Chinese medicine.
Si-Cun WANG ; Mu-Zhi LI ; Hai-Xia DANG ; Hao GU ; Jun LIU ; Zhong WANG ; Ya-Nan YU
China Journal of Chinese Materia Medica 2025;50(3):846-852
Basket trial, as an innovative clinical trial design concept, marks the transformation of medical research from the traditional large-scale and single-disease treatment to the precise and individualized treatment. By gradually incorporating the Bayesian method during development, the trial design becomes more scientific and reasonable and increases its efficiency. The fundamental principle of the Bayesian method is the utilization of prior knowledge in conjunction with new observational data to dynamically update the posterior probability. This flexibility enhances the basket trial's capacity to effectively adapt to variations during the research process. Consequently, it enables researchers to dynamically adjust research strategies based on accumulated data and improve the predictive accuracy regarding treatment responses. In addition, the design concept of the basket trial aligns with the traditional Chinese medicine(TCM) principle of "homotherapy for heteropathy". The principle of "homotherapy for heteropathy" emphasizes that under certain conditions, different diseases may have the same treatment. Similarly, basket trials allow using a uniform trial design across multiple diseases, offering enhanced operational and significant practical value in the realm of TCM, particularly within the context of syndrome-based disease research. By introducing basket trials, the design of TCM clinical studies will be more scientific and yield higher-quality evidence. This study systematically categorized various Bayesian methods and models utilized in basket trials, evaluated their strengths and weaknesses, and identified their appropriate application contexts, so as to offer a practical guide for designing basket trials in the realm of TCM.
Bayes Theorem
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Humans
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Medicine, Chinese Traditional/methods*
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Research Design
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Clinical Trials as Topic/methods*
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Drugs, Chinese Herbal/therapeutic use*
6.Correlation between body mass index and risk of multiple myeloma: a two-sample Mendelian randomization study
Fangshuo FENG ; Lanting LIU ; Lugui QIU ; Mu HAO
Journal of Leukemia & Lymphoma 2025;34(5):291-295
Objective:To explore the correlation between body mass index (BMI) and the risk of multiple myeloma (MM).Methods:A two-sample Mendelian randomization (MR) analysis was utilized. The data were obtained from genome-wide association study (GWAS) datasets in the IEU OpenGWAS database. The dataset number for exposure factor BMI was ieu-a-2, involving 339 224 mixed populations (males and females) and containing 2 555 511 single nucleotide polymorphisms (SNP); the dataset number for outcome factor MM was ieu-b-4957, involving 372 617 European populations (601 MM patients and 372 016 healthy individuals), containing 8 615 746 SNP; the BMI and MM reference genomes were both HG19/GRCh37 provided by the Genetic Investigation of Anthropometric Traits (GIANT) collaborative organization. From dataset ieu-a-2, 79 SNP significantly associated with BMI were selected as instrumental variables ( F > 10), and then validated in the outcome factor dataset (ieu-b-4957), with missing SNP excluded, resulting in 76 retained instrumental variables. MR analyses were performed using the inverse variance weighted (IVW), MR-Egger regression, weighted median method, simple mode method, and weighted mode method. Sensitivity analyses were conducted using the Cochran Q test, MR-Egger regression intercept and leave-one-out approach. Results:IVW results showed a positive correlation between BMI and the risk of MM ( OR = 1.001, 95% CI: 1.000-1.002, P = 0.012), which was supported by the MR-Egger method ( OR = 1.003, 95% CI: 1.000-1.005, P = 0.022). The sensitivity analyses results showed that neither the MR-Egger intercept (intercept = -4.336×10 -5, P = 0.158) nor the heterogeneity test (IVW: Q = 82.02, P = 0.271) found significant heterogeneity or horizontal pleiotropy, indicating high robustness of the results. Conclusions:BMI may be a potential risk factor for the development of MM.
7.The Valvular Heart Disease-specific Age-adjusted Comorbidity Index (VHD-ACI) score in patients with moderate or severe valvular heart disease.
Mu-Rong XIE ; Bin ZHANG ; Yun-Qing YE ; Zhe LI ; Qing-Rong LIU ; Zhen-Yan ZHAO ; Jun-Xing LV ; De-Jing FENG ; Qing-Hao ZHAO ; Hai-Tong ZHANG ; Zhen-Ya DUAN ; Bin-Cheng WANG ; Shuai GUO ; Yan-Yan ZHAO ; Run-Lin GAO ; Hai-Yan XU ; Yong-Jian WU
Journal of Geriatric Cardiology 2025;22(9):759-774
BACKGROUND:
Based on the China-VHD database, this study sought to develop and validate a Valvular Heart Disease- specific Age-adjusted Comorbidity Index (VHD-ACI) for predicting mortality risk in patients with VHD.
METHODS & RESULTS:
The China-VHD study was a nationwide, multi-centre multi-centre cohort study enrolling 13,917 patients with moderate or severe VHD across 46 medical centres in China between April-June 2018. After excluding cases with missing key variables, 11,459 patients were retained for final analysis. The primary endpoint was 2-year all-cause mortality, with 941 deaths (10.0%) observed during follow-up. The VHD-ACI was derived after identifying 13 independent mortality predictors: cardiomyopathy, myocardial infarction, chronic obstructive pulmonary disease, pulmonary artery hypertension, low body weight, anaemia, hypoalbuminaemia, renal insufficiency, moderate/severe hepatic dysfunction, heart failure, cancer, NYHA functional class and age. The index exhibited good discrimination (AUC, 0.79) and calibration (Brier score, 0.062) in the total cohort, outperforming both EuroSCORE II and ACCI (P < 0.001 for comparison). Internal validation through 100 bootstrap iterations yielded a C statistic of 0.694 (95% CI: 0.665-0.723) for 2-year mortality prediction. VHD-ACI scores, as a continuous variable (VHD-ACI score: adjusted HR (95% CI): 1.263 (1.245-1.282), P < 0.001) or categorized using thresholds determined by the Yoden index (VHD-ACI ≥ 9 vs. < 9, adjusted HR (95% CI): 6.216 (5.378-7.184), P < 0.001), were independently associated with mortality. The prognostic performance remained consistent across all VHD subtypes (aortic stenosis, aortic regurgitation, mitral stenosis, mitral regurgitation, tricuspid valve disease, mixed aortic/mitral valve disease and multiple VHD), and clinical subgroups stratified by therapeutic strategy, LVEF status (preserved vs. reduced), disease severity and etiology.
CONCLUSION
The VHD-ACI is a simple 13-comorbidity algorithm for the prediction of mortality in VHD patients and providing a simple and rapid tool for risk stratification.
8.The diagnostic accuracy and safety of CT-guided percutaneous lung biopsy in ≥80 years patients
Journal of Interventional Radiology 2025;34(4):414-417
Objective To evaluate the diagnostic accuracy and clinical safety of CT-guided percutaneous lung biopsy in ≥80 years patients.Methods A total of 400 patients who underwent CT-guided percutaneous lung biopsy were enrolled in this study.There were 79 patients aged ≥80 years(≥80 group)and 321 patients aged<80 years(<80 group).The diagnostic accuracy and complications of CT-guided percutaneous lung biopsy were compared between the two groups.Multivariate logistic regression analysis was used to assess the relevant risk factors for the occurrence of complications in patients aged ≥80 years.Results No statistically significant differences in the incidence of complications(including pneumothorax,pulmonary hemorrhage,hemoptysis,etc.)existed between the two groups(P>0.05).In ≥80 group and<80 group,the diagnostic accuracy was 97.47%and 97.51%respectively,the sensitivity was 97.10%and 97.17%respectively,both the specificity and positive predictive value were 100%,and the negative predictive value was 83.33%and 82.61%respectively,the differences in the above indexes between the two groups were not statistically significant(all P>0.05).In ≥80 group,the lesion size and the number of intraoperative needle direction adjustments were the independent risk factors for causing pulmonary hemorrhage(OR=0.429,9.429,P<0.05).Conclusion For 80 years patients,CT-guided percutaneous lung biopsy is clinical safe with high diagnostic accuracy.The incidence of complications and diagnostic accuracy of CT-guided percutaneous lung biopsy in patients aged ≥80 years are not significantly different from those in patients aged<80 years.
9.Development of a triplex quantitative reverse transcription-polymerase chain reac-tion for the detection of porcine epidemic diarrhea virus,transmissible gastroenter-itis virus,andporcine delta coronavirus
Qianlin CHEN ; Shaomei LI ; Yifan ZHANG ; Hao MU ; Mingni LIU ; Liu YANG ; Qingyong GUO ; Lizhi FU
Chinese Journal of Veterinary Science 2025;45(5):905-912
Swine enteric coronaviruses(SeCoV),such as porcine epidemic diarrhea virus(PEDV),transmissible gastroenteritis virus(TGEV),and porcine delta coronavirus(PDCoV),cause severe diarrhea in piglets,resulting in substantial losses in pig farming.In this study we establish a triple fluorescence reverse transcription-quantitative PCR(RT-qPCR)method for the simultaneous de-tection of PEDV,TGEV,and PDCoV.The specific primers and probes for each target virus were designed based on conserved sequences from the PEDV M gene,the TGEV ORF 1b gene,and the PDCoV ORF 1b gene respectively.Following the optimization of parameters and conditions,a triple RT-qPCR method was successfully established to simultaneously detect PEDV,TGEV,and PD-CoV.The developed assay exhibits strong specificity for these three pathogens without any cross-reaction with other common porcine viruses like CSFV,PCV2,PoRVA,PRV,and PRRSV.The de-tection limit of linear templates for pTOPO-PEDV 128,pTOPO-TGEV 116,and pTOPO-PDCoV 125 recombinant plasmids were 16.835,17.610 and 17.020 copies/μL,respectively.The intra group and inter group coefficients of variation were less than 5%,with no significant differences observed(P>0.05).Moreover,the detection consistency rate of the developed RT-qPCR was compared with standard method and showed 100%agreement.Out of 35 small intestine tissue samples,17 tested positive for PEDV,resulting in a positive rate of 48.57%(17/35).The tests for TGEV and PDCoV yielded negative results,and no mixed infections were detected.Based on the above results,the tri-ple RT-qPCR method established is specific,sensitive,stable,and rapid,and can be used for clinical detection and differential diagnosis of PEDV,TGEV,and PDCoV simultaneously,providing a method for the detection and epidemiological investigation of porcine diarrhea coronaviruses.
10.Mechanism of tigecycline resistance induced in vitro in Citrobacter freundii
Hang MU ; Hao FU ; Jie ZHOU ; Shubo WANG ; Jingyuan ZHANG ; Ledi MA ; Jin ZHANG ; Shuyong WEI
Chinese Journal of Veterinary Science 2025;45(10):2222-2230
Tigecycline(TGC)is a recently developed broad-spectrum and highly effective glycylcy-cline antibiotic that overcomes traditional tetracycline resistance mechanisms.It is widely used in the treatment of complex skin and intra-abdominal infections.However,the emergence of TGC re-sistance in recent years poses a significant challenge,and its underlying resistance mechanisms re-main incompletely understood,warranting further investigation.This study induced TGC resistance in Klebsiella aerogenes(ATCC-43864)under in vitro conditions and evaluated phenotypic chan-ges,including growth curves,motility,multidrug susceptibility,and ultrastructural alterations,be-fore and after induction.Whole-genome sequencing(WGS)and transcriptome sequencing(RNA-seq)were employed to analyze resistance-related genetic changes,which were further validated.Ef-flux pump inhibition assays and Red homologous recombination were used to investigate the roles of efflux pumps,lon deletion,and rpsM mutation in TGC resistance.A stable resistant strain,CF-T-32,was obtained,with a 32-fold increase in TGC minimum inhibitory concentration(MIC).CF-T-32 exhibited an enlarged periplasmic space between the cell wall and membrane,reduced growth and motility,and no significant changes in susceptibility to 28 antimicrobial agents,including doxy-cycline,gentamicin,and ciprofloxacin.Genomic analysis revealed no significant differences in ge-nome composition or interference from exogenous plasmids between the parental and induced strains.However,two missense mutations were identified in rpsM and lon.Transcriptomic analysis and qPCR validation showed significant upregulation of efflux pump genes(acrA and acrB)in the AcrAB-TolC system and downregulation of ribosomal protein genes(rpsM,rpsJ,and rpsC).Ef-flux pump inhibition and Red homologous recombination experiments demonstrated that the rpsM C287T missense mutation,leading to a Pro96Leu substitution and reduced expression,is likely the primary factor contributing to TGC resistance in the induced strain.


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