Objective To develop and validate an efficient and simple liquid chromatography with tandem mass spectrometry(LC-MS/MS)method for determination of polymyxin E in human plasma,and apply the established method in therapeutic drug monitoring(TDM)of polymyxin E.Methods The LC-MS/MS platform was based on AB SCIEX HPLC-4500MD system.Gradient elution was performed with 0.2％formic acid in water and 0.2％formic acid in acetonitrile.Phenomenex Kinetex XB-C18 column(100 mm × 2.1 mm,2.6 μm)were used.The analytes were detected by electrospray ionization(ESI)positive multiple reaction monitoring mode.The ion pairs for analytes(polymyxins E1,E2)and internal standard(polymyxins B1)were m/z 390.7→101.3,m/z 386.0→101.2,and m/z 402.3→101.2,respectively.Plasma samples were processed with protein precipitation method.Results Polymyxin E1 and E2 showed good linearity in the range of 0.031 2-6.24 mg/L and 0.006 15-1.23 mg/L,respectively.The within-run accuracy of polymyxin E1 and E2 in plasma ranged from 89.4％to 99.8％and 91.5％to 108.2％,respectively,while the between-run accuracy ranged from 91.8％to 104.7％and 95.6％to 105.2％,respectively.The within-run precision of polymyxin E1 and E2 in plasma ranged from 4.9％to 8.9％and 2.8％to 8.5％,respectively,while the between-run precision ranged from 4.1％to 7.6％and 4.2％to 9.8％,respectively.The average internal standard normalized matrix effect factors of polymyxins E1 and E2 were 96.9％-111.2％and 106.1％-112.8％in blank plasma samples from 6 different sources,102.5％-106.8％and 98.8％-105.2％in lipemic plasma,respectively,107.8％-108.9％and 106.9％-1 07.4％in hemolyzed plasma,respectively.The precision of matrix effects was less than 15.0％.The average recovery rate was 102.9％-107.5％for polymyxin E1 and E2,and 107.0％for internal standard polymyxin B1.The precision was less than 3.7％.Conclusions In this study,a simple and efficient LC-MS/MS method was established for determination of polymyxin E1 and E2 in human plasma,which is reliable in the therapeutic drug monitoring and pharmacokinetic study of polymyxin E.

Aim To investigate the regulatory mecha-nisms of donepezil on the expression and enzymatic ac-tivity of cytochrome P450 3A4(CYP3A4),elucidate the synergistic impact of hypoxia on CYP3A4 function,and reveal its potential association with drug-induced cardiotoxicity,particularly QT interval prolongation.Methods Western blot,co-immunoprecipitation,and gene knockdown techniques were employed to evaluate the effects of donepezil and hypoxia on CYP3A4 pro-tein expression.CYP3A4 enzymatic activity was as-sessed using an in vitro incubation system with rat liver microsomes combined with high-performance liquid chromatography(HPLC),and the half-maximal inhib-itory concentration(IC50)was determined.Results Donepezil(10 μmol·L-1)and hypoxia reduced CYP3A4 protein expression to 31.75％and 45.90％of the control levels,respectively.Both interventions activated the gp78-mediated ubiquitin-proteasome path-way,significantly increasing CYP3A4 ubiquitination levels by 2.1-fold compared to the control group,thereby promoting proteasomal degradation.Donepezil inhibited CYP3A4 enzyme activity with an IC50 of 83.4μmol·L-1,and hypoxia synergistically enhanced this inhibitory effect,reducing the IC50 to 20.79 μmol·L-1.Conclusion Donepezil downregulates CYP3A4 function through dual mechanisms involving ubiquitin-mediated proteasomal degradation and direct enzymatic inhibition.Hypoxia potentiates this effect,leading to impaired metabolism of CYP3A4 substrate drugs,ele-vated plasma drug concentrations(1.6-2.3-fold in-crease compared to normal metabolic conditions),and an increased risk of QT interval prolongation and other forms of cardiotoxicity.

Bovine rotavirus(BRV)is an important pathogen causing diarrhea in calves.To understand the genomic charac-teristics and genetic variations in bovine rotavirus,and to further enrich data on the biological characteristics of rotavirus,we aimed to amplify 11 gene segments of the isolated and cultured G6P[1]bovine rotavirus BLL strain,perform whole genome se-quencing,and analyze the molecular characteristics.MEGA7.0 and DNAMAN software were used for homology and typing a-nalysis,and the whole genome phylogenetic tree was constructed to analyze genetic evolution relationships.The complete geno-type of the BLL strain was G6-P[1]-I2-R2-C2-M2-A3-N2-T6-E2-H3.Phylogenetic analysis of the VP7 and VP4 genes of the BLL strain showed that the VP7 gene had the highest homology with RVA/Cow-wt/HB01/China/2021,and the VP4 gene of the BLL strain was in the same branch as RVA/Human-tc/ISR/Ro8059/1995.From the sequence alignment of VP8*amino acids,the sialic acid domain of the BLL strain was found to be similar to that in other P[1]strains,but different from those in other types of strains,except for residue 189,which was the same as that in Ro8059 but different from that in other strains.The results suggested that the BLL strain might potentially infect humans.Therefore,continued monitoring and study of the biological characteristics of this strain are necessary to provide more information and evidence supporting further research on the cross-species transmission of group A rotavirus in China.

Aim To explore the in vitro anti-human triple-negative breast cancer(TNBC)effect and mech-anism of Austocystin R.Methods MTT assay was used to evaluate the anti-tumor potential of Austocystin R for various human tumor cells and normal cells.Flow cytometry was employed to evaluate the influence on cell cycle progression.mRFP-GFP-LC3 adenovirus transfection was used to evaluate the autophagic flux process.Western blot assay was used to verify the effect of Austocystin R on the expression of related pro-teins.Results The results showed that Austocystin R significantly inhibited the proliferation of multiple tumor cells in a dose-dependent manner,especially for the MDA-MB-231 cells with an IC50 of 1.45μmol·L-1.In addition,Austocystin R increased the protein expression of PTEN,p53,p-p53,p27,p21,and down-regulated the expression of p-PI3K,p-AKT and p-mTOR.Austocystin R can significantly increase the proportion of S-phase MDA-MB-231 cells,inhibit the expression of Cyclin D1,CDK4,CDK6,Rb,Cyclin B1 and CDK1,and promote the expression of Cyclin E1 and CDK2.Austocystin R can promote the autophagic flux process of MDA-MB-231 cells,promote the expres-sion of LC3 Ⅰ/Ⅱ,p-Beclin-1,p-ULK1,HMGB-1 and Atg 14 proteins,and inhibit the expression of Beclin-1,ULK1,p62,ATG 3,ATG 4B,ATG 5,ATG 7,ATG 12,ATG 13 and ATG 16L1 proteins.Conclusion Austo-cystin R can exhibit its anti-TNBC activity by inhibi-ting the PI3K/AKT/mTOR signaling pathway,blocking the cell cycle at the S phase and inducing autophagic cell death.

Aim To explore the in vitro anti-human triple-negative breast cancer(TNBC)effect and mech-anism of Austocystin R.Methods MTT assay was used to evaluate the anti-tumor potential of Austocystin R for various human tumor cells and normal cells.Flow cytometry was employed to evaluate the influence on cell cycle progression.mRFP-GFP-LC3 adenovirus transfection was used to evaluate the autophagic flux process.Western blot assay was used to verify the effect of Austocystin R on the expression of related pro-teins.Results The results showed that Austocystin R significantly inhibited the proliferation of multiple tumor cells in a dose-dependent manner,especially for the MDA-MB-231 cells with an IC50 of 1.45μmol·L-1.In addition,Austocystin R increased the protein expression of PTEN,p53,p-p53,p27,p21,and down-regulated the expression of p-PI3K,p-AKT and p-mTOR.Austocystin R can significantly increase the proportion of S-phase MDA-MB-231 cells,inhibit the expression of Cyclin D1,CDK4,CDK6,Rb,Cyclin B1 and CDK1,and promote the expression of Cyclin E1 and CDK2.Austocystin R can promote the autophagic flux process of MDA-MB-231 cells,promote the expres-sion of LC3 Ⅰ/Ⅱ,p-Beclin-1,p-ULK1,HMGB-1 and Atg 14 proteins,and inhibit the expression of Beclin-1,ULK1,p62,ATG 3,ATG 4B,ATG 5,ATG 7,ATG 12,ATG 13 and ATG 16L1 proteins.Conclusion Austo-cystin R can exhibit its anti-TNBC activity by inhibi-ting the PI3K/AKT/mTOR signaling pathway,blocking the cell cycle at the S phase and inducing autophagic cell death.

Objective:To investigate exercise fear condition and its influencing factors in patients with coronary heart dis-ease(CHD)involving in phase Ⅱ cardiac rehabilitation after percutaneous coronary intervention(PCI).Methods:Conven-ience sampling was performed among cardiac rehabilitation patients from a Shanxi grade-A tertiary hospital between Janu-ary 2023 and June 2023.General data questionnaire,Tampa Scale for Kinesiophobia-Short Version for Heart patients(TSK-SV H),the Multidimensional Scale of Perceived Social Support(MSPSS)and the Post Percutaneous Coronary In-tervention Health Literacy Scale(PPCIHLS)were used for assessment.Pearson and Spearman rank correlation analyses were applied to investigate the relationships between social support factors and health literacy factors with patients'fear of exercise;multivariate linear regression models and quantile regression models were used to analyze the influencing factors of fear of exercise.Results:Among the 118 patients,average TSK-SV H score was(33.78±3.79)points;10.2％patients showed significant fear.The correlation analysis showed that PPCIHLS score was negatively correlated with TSK-SV H score(r=-0.423,P＜0.001).Results from multivariate regression analysis indicated that health literacy,cardiac func-tion class and drinking status affected the average score of exercise fear(P＜0.05 all).The quantile regression model pro-vided additional insights,showing that the impact of factors such as living situation,drinking status,cardiac function class and health literacy on exercise fear varied across different quantiles.Notably,cardiac function class had a consistently posi-tive effect on TSK-SV H score at various quantiles.Conclusion:Improving health literacy and tailored rehabilitation plans are vital to reduce exercise fear and improve cardiac rehabilitation effect.

Fucoidan(FUC)is a natural seaweed-derived drug.Previously,our experiments have shown that FUC can significantly inhibit the cell viability of human osteosarcoma 143B cells and induce cell death,but the mechanism remains unclear.Ferroptosis,a novel form of cell death,has emerged as an important target for tumor therapy.This study aims to investigate whether FUC induces ferroptosis of 143B cells and elucidate its underlying molecular mechanisms.CCK-8 and LDH assays result showed that FUC(10,100,400 μg/mL)significantly reduced cell viability of 143B cells and induced cell death.Calce-in-AM staining,FeRhoNox-1 staining,and C11 BODIPY 581/591 staining indicated that FUC obviously increased the levels of labile iron pool(LIP),Fe2+,and lipid reactive oxygen species(Lip ROS)in 143B cells.Chemical colorimetric analysis revealed that FUC markedly decreased intracellular Glutathi-one(GSH)contents.Real-time quantitative PCR showed that FUC dramatically reduced the mRNA lev-els of ferroptosis-related factors solute carrier family 7 member 11(SLC7A11)and glutathione peroxidase 4(GPX4),while increasing the mRNA levels of prostaglandin endoperoxide synthase 2(PTGS2)and acyl-CoA synthetase long-chain family member 4(ACSL4).Western blotting analysis demonstrated that FUC significantly reduced the protein levels of SLC7A11 and GPX4,and the ratios of p-PI3K/PI3K,p-AktSer473/Akt,and p-AktThr308/Akt,but increased the protein level of ACSL4.Immunofluorescence staining showed that FUC obviously inhibited the nuclear translocation of p-AktSer473.The ferroptosis in-hibitor ferrostatin-1(Fer-1)and iron chelator deferoxamine(DFO)remarkably suppressed cell death in-duced by FUC in 143B cells.Additionally,the PI3K/Akt pathway activator 740Y-P significantly inhibi-ted FUC-induced iron overload and lipid peroxidation in 143B cells,and restored the protein levels of SLC7A11 and GPX4.In conclusion,FUC can induce ferroptosis of 143B cells by inhibiting the PI3K/Akt signaling pathway,which may be a potential target for the prevention and treatment of osteosarcoma.

Inflammatory response,immunosuppression,and drug sensitivity have been reported to have a significant correlation with the disulfidptosis levels in cancer patients.However,the value of disulfidpto-sis in colorectal cancer therapy remains unclear.Therefore,we classified the CRC cells into different cell types using single-cell sequencing data and cell-specific markers and analyzed their relationship with the cell disulfidptosis level.We found that the high disulfidptosis regions were concentrated in epithelial-like CRC cells.Further exploration using the disulfidptosis and programmed cell death 1 inhibitor therapy treated differential expression genes indicated that CRC patients with high disulfidptosis levels exhibited a lower risk profile and increased sensitivity to immunotherapy.By using the spatial transcriptomic analy-sis,we found that ubiquinol-cytochrome c reductase core protein 1(UQCRC1),a disulfidptosis-related gene,is highly expressed in epithelial-like CRC cells and co-localized with immune-infiltrated tumor re-gions.Additional bioinformatic analyses and experimental validation further confirmed that UQCRC1 was downregulated in CRC tissues.Overexpression of UQCRC1 suppressed CRC cell proliferation and migra-tion.These findings indicate that UQCRC1 is a potential target for CRC diagnosis and treatment.

Aim To design and synthesize a series of glycyrrhetinic acid derivatives by using glycyrrhetinic acid as the parent nucleus,screen their antitumor activ-ities,and investigate the in vitro and in vivo antitumor effects and mechanisms of the most active compound.Methods MTT assay was used to screen for the com-pound with the most potent antitumor activity.MTT as-say,wound healing assay,colony formation assay and Transwell migration assay were used to evaluate the effects of the compound on tumor cell viability and mi-gration.Flow cytometry was employed to assess the im-pact of the compound on tumor cell cycle progression and apoptosis.Western blot was conducted to verify the effects on the expression of pro-apoptotic proteins Bax,caspase-3 and cleaved caspase-3.A mouse model of hepatocellular carcinoma ascites tumor was estab-lished to examine the antitumor effects of the compound in vivo.Results Compound C22 was identified as having the most significant inhibitory effect on hepato-cellular carcinoma cells.C22 inhibited the viability and migration of hepatocellular carcinoma cells in a time and concentration-dependent manner.C22 upreg-ulated the expression of pro-apoptotic proteins Bax,caspase-3 and cleaved caspase-3 in hepatocellular car-cinoma cells,induced apoptosis,and arrested the cell cycle in the G0/G1 and S phases.C22 significantly re-duced the growth of mouse hepatocellular carcinoma as-cites tumors and prolonged survival.Conclusion Glycyrrhetinic acid derivative C22 significantly inhibits the viability and migration of hepatocellular carcinoma cells in vitro and in vivo,and induces cell cycle arrest and apoptosis.

Objective To develop and validate an efficient and simple liquid chromatography with tandem mass spectrometry(LC-MS/MS)method for determination of polymyxin E in human plasma,and apply the established method in therapeutic drug monitoring(TDM)of polymyxin E.Methods The LC-MS/MS platform was based on AB SCIEX HPLC-4500MD system.Gradient elution was performed with 0.2％formic acid in water and 0.2％formic acid in acetonitrile.Phenomenex Kinetex XB-C18 column(100 mm × 2.1 mm,2.6 μm)were used.The analytes were detected by electrospray ionization(ESI)positive multiple reaction monitoring mode.The ion pairs for analytes(polymyxins E1,E2)and internal standard(polymyxins B1)were m/z 390.7→101.3,m/z 386.0→101.2,and m/z 402.3→101.2,respectively.Plasma samples were processed with protein precipitation method.Results Polymyxin E1 and E2 showed good linearity in the range of 0.031 2-6.24 mg/L and 0.006 15-1.23 mg/L,respectively.The within-run accuracy of polymyxin E1 and E2 in plasma ranged from 89.4％to 99.8％and 91.5％to 108.2％,respectively,while the between-run accuracy ranged from 91.8％to 104.7％and 95.6％to 105.2％,respectively.The within-run precision of polymyxin E1 and E2 in plasma ranged from 4.9％to 8.9％and 2.8％to 8.5％,respectively,while the between-run precision ranged from 4.1％to 7.6％and 4.2％to 9.8％,respectively.The average internal standard normalized matrix effect factors of polymyxins E1 and E2 were 96.9％-111.2％and 106.1％-112.8％in blank plasma samples from 6 different sources,102.5％-106.8％and 98.8％-105.2％in lipemic plasma,respectively,107.8％-108.9％and 106.9％-1 07.4％in hemolyzed plasma,respectively.The precision of matrix effects was less than 15.0％.The average recovery rate was 102.9％-107.5％for polymyxin E1 and E2,and 107.0％for internal standard polymyxin B1.The precision was less than 3.7％.Conclusions In this study,a simple and efficient LC-MS/MS method was established for determination of polymyxin E1 and E2 in human plasma,which is reliable in the therapeutic drug monitoring and pharmacokinetic study of polymyxin E.