ObjectiveTo observe the protective effect of Erchentang （ECT） on SiO₂-induced lung injury in rats and to explore its underlying mechanism. MethodsA rat model of lung injury was established by a single intratracheal instillation of 50 mg·mL^-1 SiO₂ suspension. Thirty male Sprague-Dawley （SD） rats were randomly assigned to five groups： control， model， low and high-dose （4.5 g·kg^-1·d^-1 and 9 g·kg^-1·d^-1， respectively） ECT， and dexamethasone （0.2 mg·kg^-1·d^-1）. All the groups were treated for 4 consecutive weeks. Histopathological alterations in the lung tissue were examined by hematoxylin and eosin （HE） staining. The levels of malondialdehyde （MDA）， superoxide dismutase （SOD）， and glutathione peroxidase （GSH-Px） in the lung tissue were measured through biochemical assays. The expression of key molecules in the nuclear factor erythroid 2-related factor 2 （Nrf2）/heme oxygenase-1 （HO-1） pathway was determined by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， Western blot， and immunofluorescence assay. The primary active components of ECT were identified by ultra-performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS）， and their binding affinity to Nrf2/HO-1 was assessed by molecular docking. Untargeted metabolomics of the lung tissue was performed based on UPLC-quadrupole time-of-flight mass spectrometry （UPLC-Q-TOF-MS）， and correlation analysis was performed to identify differential metabolites and parameters closely associated with the Nrf2/HO-1 pathway. ResultsCompared with the control group， the model group exhibited a reduction in body weight gain， an increase in lung index， increased MDA content， weakened SOD and GSH-Px activities in the lung tissue， down-regulated mRNA and protein levels of Nrf2 and protein levels of HO-1 and GPX4， and an up-regulated protein level of Keap1 （P<0.05， P<0.01）. Treatment with ECT attenuated the SiO₂-induced decline in body weight （P<0.05）， alleviated inflammatory cell infiltration and silicotic nodule formation in alveoli， and reduced the MDA content and enhanced the SOD and GSH-Px activities in the lung tissue （P<0.05， P<0.01）. UPLC-MS/MS and molecular docking revealed that core components of ECT， such as hesperidin and glycyrrhizic acid， displayed strong binding affinity to Nrf2/HO-1. Molecular biological experiments demonstrated that ECT promoted nuclear translocation of Nrf2， up-regulated the mRNA and protein levels of HO-1 and GPX4， and down-regulated Keap1 expression （P<0.05， P<0.01）. Metabolomic analysis indicated that ECT reversed the SiO₂-induced aberrant expression of metabolites， including linoleic acid and glutamine （P<0.05， P<0.01）. Correlation analysis showed that Nrf2 and HO-1 were positively correlated with SOD and GSH-Px （P<0.05， P<0.01）， but negatively correlated with glutamine and serine （P<0.05， P<0.01）. ConclusionECT may activate the Nrf2/HO-1 pathway through its core active components， thereby regulating oxidative stress and metabolic disorders to ameliorate SiO₂-induced lung injury in rats. This study provides experimental evidence for ECT in the prevention and treatment of occupational lung injury.

Objective:To dynamically assess liver fibrosis using magnetic resonance elastography (MRE) and explore factors associated with fibrosis reversal in patients with metabolic dysfunction-associated steatohepatitis (MASH).Methods:This study included data from patients diagnosed with MASH by liver biopsy who underwent at least two MRE examinations. Patients were divided into a fibrosis reversal group and a non-reversal group according to whether MRE values decreased by 20% during follow-up. Differences in clinical data between the groups were compared using analysis of variance, the Kruskal-Wallis test, and the chi-square test. Univariate and multivariate logistic regression analyses were used to explore independent risk factors for fibrosis reversal in MASH.Results:A total of 46 cases were included in this study (mean age 50.1±12.3 years, BMI 26.1±3.1 kg/m2). Among them, the reversal group accounted for 26.1%. The rate of decrease in MRI proton density fat fraction (PDFF) was significantly higher in the reversal group (-50.0% vs. -8.1%, P=0.001) than in the non-reversal group between the two MRE examinations. The reversal group showed a more significant change rate of decreases in fasting insulin (-37.3% vs. -3.6%, P=0.011), insulin resistance index (-38.6% vs. -6.5%, P=0.044), and ALP (-24.9% vs. 0, P=0.004). Multivariate logistic regression analysis indicated that the rate of change in MRI PDFF was an independent predictor of fibrosis reversal ( OR=0.96, 95% CI: 0.92-1.00, P=0.046). Conclusion:A decrease in MRI proton density fat fraction levels is independently associated with liver fibrosis reversal in MASH, suggesting that intervention targeting liver fat content may be an effective treatment strategy.

This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.

AIM:To investigate the mechanism by which interleukin-13(IL-13)influences vascular smooth muscle cell(VSMC)phenotypic transformation and subsequently contributes to vascular intimal hyperplasia in rats.METHODS:A total of 32 male SD rats,aged 5～7 weeks and weighing 330～360 g,were randomly divided into 4 groups(n=8 per group):normal(Nor)group,normal treatment(Nor+IL-13 neutralizing antibody,Nor+IL-13Nab)group,inju-ry(Inj)group,and injruy treatment(Inj+IL-13Nab)group.A 2F balloon catheter was used to induce mechanical injury in the left common carotid artery of SD rats to establish a vascular intimal hyperplasia model.Hematoxylin-eosin staining was performed to observe vascular structural changes.Enzyme-linked immunosorbent assay(ELISA)kits were used to measure IL-13 and transforming growth factor-β1(TGF-β1)levels.Human aortic smooth muscle cells(HA-SMCs)were cultured in vitro.Flow cytometry was conducted to assess peripheral blood CD4+IL-13+T cell content.Real-time quantita-tive PCR(RT-qPCR)was employed to evaluate gene expression levels of α-smooth muscle actin,osteopontin,calponin,collagen type Ⅰ/Ⅲ,proliferating cell nuclear antigen and Ki-67 antigen.Transwell and scratch wound assays were per-formed to assess cell migration.RESULTS:Compared with the model group,administration of IL-13Nab significantly in-hibited vascular intimal hyperplasia induced by mechanical vascular injury by antagonizing high plasma IL-13 levels(P<0.01).Immunofluorescence and mRNA analysis showed that neutralizing high plasma IL-13 suppressed collagen accumu-lation(P<0.01)and VSMC phenotypic transformation(P<0.01)in the injured vessels but did not inhibit peripheral blood CD4+IL-13+T cell activation.Incubation of HA-SMCs with recombinant human IL-13(rhIL-13)promoted cell pro-liferation and migration(P<0.01)as well as phenotypic transformation(P<0.01).Additional evidence suggested that rhIL-13-induced HA-SMC phenotypic transformation was associated with the regulation of TGF-β1 secretion by HA-SMCs.CONCLUSION:Interleukin-13 promotes vascular intimal hyperplasia by regulating VSMC phenotypic transformation through TGF-β1 secretion in rat models.

This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.

AIM:To investigate the mechanism by which interleukin-13(IL-13)influences vascular smooth muscle cell(VSMC)phenotypic transformation and subsequently contributes to vascular intimal hyperplasia in rats.METHODS:A total of 32 male SD rats,aged 5～7 weeks and weighing 330～360 g,were randomly divided into 4 groups(n=8 per group):normal(Nor)group,normal treatment(Nor+IL-13 neutralizing antibody,Nor+IL-13Nab)group,inju-ry(Inj)group,and injruy treatment(Inj+IL-13Nab)group.A 2F balloon catheter was used to induce mechanical injury in the left common carotid artery of SD rats to establish a vascular intimal hyperplasia model.Hematoxylin-eosin staining was performed to observe vascular structural changes.Enzyme-linked immunosorbent assay(ELISA)kits were used to measure IL-13 and transforming growth factor-β1(TGF-β1)levels.Human aortic smooth muscle cells(HA-SMCs)were cultured in vitro.Flow cytometry was conducted to assess peripheral blood CD4+IL-13+T cell content.Real-time quantita-tive PCR(RT-qPCR)was employed to evaluate gene expression levels of α-smooth muscle actin,osteopontin,calponin,collagen type Ⅰ/Ⅲ,proliferating cell nuclear antigen and Ki-67 antigen.Transwell and scratch wound assays were per-formed to assess cell migration.RESULTS:Compared with the model group,administration of IL-13Nab significantly in-hibited vascular intimal hyperplasia induced by mechanical vascular injury by antagonizing high plasma IL-13 levels(P<0.01).Immunofluorescence and mRNA analysis showed that neutralizing high plasma IL-13 suppressed collagen accumu-lation(P<0.01)and VSMC phenotypic transformation(P<0.01)in the injured vessels but did not inhibit peripheral blood CD4+IL-13+T cell activation.Incubation of HA-SMCs with recombinant human IL-13(rhIL-13)promoted cell pro-liferation and migration(P<0.01)as well as phenotypic transformation(P<0.01).Additional evidence suggested that rhIL-13-induced HA-SMC phenotypic transformation was associated with the regulation of TGF-β1 secretion by HA-SMCs.CONCLUSION:Interleukin-13 promotes vascular intimal hyperplasia by regulating VSMC phenotypic transformation through TGF-β1 secretion in rat models.

Objective:To dynamically assess liver fibrosis using magnetic resonance elastography (MRE) and explore factors associated with fibrosis reversal in patients with metabolic dysfunction-associated steatohepatitis (MASH).Methods:This study included data from patients diagnosed with MASH by liver biopsy who underwent at least two MRE examinations. Patients were divided into a fibrosis reversal group and a non-reversal group according to whether MRE values decreased by 20% during follow-up. Differences in clinical data between the groups were compared using analysis of variance, the Kruskal-Wallis test, and the chi-square test. Univariate and multivariate logistic regression analyses were used to explore independent risk factors for fibrosis reversal in MASH.Results:A total of 46 cases were included in this study (mean age 50.1±12.3 years, BMI 26.1±3.1 kg/m2). Among them, the reversal group accounted for 26.1%. The rate of decrease in MRI proton density fat fraction (PDFF) was significantly higher in the reversal group (-50.0% vs. -8.1%, P=0.001) than in the non-reversal group between the two MRE examinations. The reversal group showed a more significant change rate of decreases in fasting insulin (-37.3% vs. -3.6%, P=0.011), insulin resistance index (-38.6% vs. -6.5%, P=0.044), and ALP (-24.9% vs. 0, P=0.004). Multivariate logistic regression analysis indicated that the rate of change in MRI PDFF was an independent predictor of fibrosis reversal ( OR=0.96, 95% CI: 0.92-1.00, P=0.046). Conclusion:A decrease in MRI proton density fat fraction levels is independently associated with liver fibrosis reversal in MASH, suggesting that intervention targeting liver fat content may be an effective treatment strategy.

Hyperbranched polymers (HBPs) have drawn great interest in the biomedical field on account of their special morphology, low viscosity, self-regulation, and facile preparation methods. Moreover, their large intramolecular cavities, high biocompatibility, biodegradability, and targeting properties render them very suitable for anti-tumor drug delivery. Recently, exploiting the specific characteristics of the tumor microenvironment, a range of multifunctional HBPs responsive to the tumor microenvironment have emerged. By further introducing various types of drugs through physical embedding or chemical coupling, the resulting HBPs based delivery systems have played a crucial part in improving drug stability, increasing effective drug concentration, decreasing drug toxicity and side effects, and enhancing anti-tumor effect. Here, based on different types of tumor microenvironment stimulation signals such as pH, redox, temperature, etc., we systematically review the preparation and response mechanism of HBPs, summarize the latest advances in drug delivery applications, and analyze the challenges and future research directions for such nanomaterials in biomedical clinical applications.

Objective:To compare the results of invasive prenatal diagnosis and preimplantation genetic testing (PGT) and explore the underlying mechanism.Methods:Clinical data of pregnant women undergoing PGT and invasive prenatal diagnosis at the Sixth Affiliated Hospital of Sun Yat-sen University from January 2019 to December 2022 were collected. The results of PGT and invasive prenatal diagnosis were compared, and the outcomes of pregnancies were followed up. This study has been approved by the Medical Ethics Committee of the the Sixth Affiliated Hospital of Sun Yat-sen University (No. 2022SLYEC-491).Results:A total of 172 couples were included in this study, and 26 non-targeted variants were discovered upon prenatal diagnosis, including 10 cases (38.5%) by chromosomal karyotyping, 15 (57.7%) by chromosomal microarray analysis (CMA), and 1 (3.8%) by whole exome sequencing. The 10 karyotypic anomalies had included 6 chromosomal polymorphisms, 2 chromosomal mosaicisms, 1 paternally derived translocation, and 1 missed maternal chromosomal inversion. CMA has identified 15 copy number variations (CNVs), which included 11 microdeletions and microduplications, 3 loss of heterozygosity, and 1 low-level mosaicism of paternal uniparental disomy. One CNV was classified as pathogenic, and another one was likely pathogenic, whilst the remaining 13 were classified as variants of uncertain significance. Therefore, 8.7% of CNVs was detected by invasive prenatal diagnosis after PGT. 92.3% (24/26) of the non-targeted variants have been due to technological limitations of next-generation sequencing (NGS).Conclusion:Invasive prenatal diagnosis after PGT can detect non-targeted variants, which may further reduce the incidence of birth defects.

Hyperbranched polymers(HBPs)have drawn great interest in the biomedical field on account of their special morphology,low viscosity,self-regulation,and facile preparation methods.Moreover,their large intramolecular cavities,high biocompatibility,biodegradability,and targeting properties render them very suitable for anti-tumor drug delivery.Recently,exploiting the specific characteristics of the tumor microenvironment,a range of multifunctional HBPs responsive to the tumor microenvironment have emerged.By further introducing various types of drugs through physical embedding or chemical coupling,the resulting HBPs based delivery systems have played a crucial part in improving drug sta-bility,increasing effective drug concentration,decreasing drug toxicity and side effects,and enhancing anti-tumor effect.Here,based on different types of tumor microenvironment stimulation signals such as pH,redox,temperature,etc,we systematically review the preparation and response mechanism of HBPs,summarize the latest advances in drug delivery applications,and analyze the challenges and future research directions for such nanomaterials in biomedical clinical applications.