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.

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.

Diabetic neurogenic bladder(DNB)is an autonomic neuropathy,which is a common complication of diabetes mellitus(DM)with a high disability rate.Emphysematous cystitis(EC)is a rare and life-threatening urological disease.A patient with DNB and EC was admitted to our hospital,who was complicated with bilateral hydronephrosis and double ureters.After comprehensive treatment with indwelling catheterization,intravenous application of broad-spectrum antibiotics,and Ins hypoglycemic therapy,the re-examination of urinary CT showed that bilateral hydronephrosis,double ureters,and bladder gas disappeared,and the indicators were improved compared with before.Due to the severe condition of the patient with DNB,the residual urine volume of the bladder increased day by day after the catheter was removed,which led to long-term indwelling catheter after discharge.

Objective To study the clinical value of stroboscopic laryngoscope combined with narrow band imaging endoscope in the diagnosis of benign and malignant glottic lesions.Methods A total of 60 patients(84 sides of vocal cord)who visited our department from June 2022 to January 2023 with hoarseness as the main complaint and were found to have glottic lesions by electronic nasopharyngoscopy were selected.In all 60 patients with 84 sides of vocal cord degenerative lesions,stroboscopic laryngoscopy and narrow band imaging(NBI)endoscopy were com-pleted.The examination results were evaluated and graded separately.The same operative group performed the re-section biopsy of vocal cord lesions under general anesthesia and laryngoscope respectively,and the pathological re-sults were used as the diagnostic gold standard.With sensitivity,specificity,accuracy,false negative rate,and false positive rate as the main evaluation indexes,the differences in diagnostic accuracy between single test technique and combined application of the two techniques were analyzed.Results Pathological results showed squamous cell carci-noma on 18 sides,carcinoma in situ on 4 sides,severe dysplasia on 4 sides,mild and moderate dysplasia on 13 sides,and papilloma,chronic,mucosal,nflammation,hyperplasia,hypokeratosis,hyperkeratosis on 45 sides.The sensitivity of strobe laryngoscopy detection was 53.06％and specificity was 60.34％.The sensitivity of NBI endo-scopic detection was 88.46％,and the specificity was 89.66％.The sensitivity of strobe laryngoscopy combined with NBI endoscopy was 96.15％,and the specificity was 94.83％.The areas under the ROC curve of strobe laryn-goscopy,NBI endoscopy and white light imaging combined with narrowband imaging were 0.888(95％CI:0.820～0.957),0.943(95％CI:0.885～1),0.970(95％CI:0.942～0.999),respectively.The area under the curve of the combined method was higher than that of the single method,and the difference was statistically significant(P＜0.05).Conclusion Stroboscopic laryngoscope combined with NBI endoscope can improve the diagnostic accuracy of benign and malignant glottic lesions.

Objective:To analyze the risk factors for human cytomegalovirus (HCMV) infection in pediatric recipients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT).Methods:Clinical data of children who underwent first allo-HSCT were retrospectively analyzed from March 2017 to November 2024. A total of 259 pediatric allo-HSCT recipients were analyzed through comparing HCMV infection group (n=115) and Non-HCMV infection group (n=144). Clinical characteristics were compared, and risk factors for HCMV infection were analyzed using univariate and multivariate logistic regression.Results:The result of univariate analysis showed that adrenoleukodystrophy (ALD), length of hospitalization, duration of antiviral therapy, and bacterial infection were significantly associated with HCMV infection in pediatric allo-HSCT recipients ( P<0.05). The result of multivariate analysis showed that ALD was an independent protective factor against HCMV infection of allo-HSCT recipients ( P<0.05) [OR=0.22, 95% CI: 0.06-0.86], while umbilical cord blood transplantation (UCBT) was an independent risk factor for HCMV infection in allo-HSCT recipients ( P<0.05) [OR=6.13, 95% CI: 1.34-28.04]. When the area under the ROC curve (AUC) for predicting post-transplant relapse based on HCMV viral load was 0.75 (95% CI: 0.55-0.94, P=0.014) and at the cutoff value of 3×10 3 copies/ml, the sensitivity and specificity for predicting relapse were 81.13% and 66.67%, respectively. Conclusions:HCMV infection in pediatric allo-HSCT recipients may lead to longer hospitalization and increased risk of relapse.

Objective:To analyze the clinical characteristics and cytokines expression characteristics in infants with mild and severe respiratory syncytial virus (RSV) infection.Methods:From May 2023 to December 2023, plasma samples and clinical information were collected from 16 infants with RSV infection and 14 control infants. Cytek Aurora flow cytometry (Cytek, America) and Enzyme linked immunosorbent assay (ELISA) were used to detect the expression levels of 25 cytokines after mild and severe RSV infection.Results:Cough and nasal obstruction were the main clinical manifestations in infants with mild RSV infection, accompanied by polypnea, wheezing and other symptoms. The main symptoms of severe RSV infection were cough and rales, accompanied by fever and polypnea. In comparison with the control group, the expression levels of IL-2, IL-4, IL-5, IL-6, IL-9, IL-13, IL-22, TNF-α, IFN-α, IFN-β, MIP-1β, I-TAC, ENA-78, GROα, Eotaxin, and MCP-1 in the RSV infection group all exhibited an upregulation trend. Both IP-10 and MIP-3α demonstrated a downward trend in the RSV infection group; however, there was no statistically significant difference ( P>0.05). The levels of IL-10, IFN-γ, MIP-1α, and IL-8 in the RSV infection group were significantly higher than those in the control group, whereas the levels of MIG, TARC, and RANTES in the RSV infection group were significantly lower than those in the control group ( P<0.05). The levels of IL-2, IL-4, IL-5, IL-6, IL-9, IL-10, IL-13, IL-22, IFN-β, IFN-γ, TNF-α, IL-8, I-TAC, MIP-1β, Eotaxin, and MCP-1 in the mild RSV infection group were significantly higher than those in the severe RSV infection group ( P>0.05). Among these, the levels of MIG, RANTES, TARC, MIP-3α, and ENA-78 in the mild infection group were all lower than those in the severe infection group. The expressions of ENA-78 and MIP-1α in the severe infection group were significantly higher than those in the mild infection group and also higher than those in the control group. There was no significant difference in IP-10 and GROα between the mild and severe RSV infection groups ( P>0.05). Conclusions:The differences in clinical features and cytokines between infants with mild and severe RSV infection provide important data support for the prevention and treatment of RSV infection in infants.

Diabetic neurogenic bladder(DNB)is an autonomic neuropathy,which is a common complication of diabetes mellitus(DM)with a high disability rate.Emphysematous cystitis(EC)is a rare and life-threatening urological disease.A patient with DNB and EC was admitted to our hospital,who was complicated with bilateral hydronephrosis and double ureters.After comprehensive treatment with indwelling catheterization,intravenous application of broad-spectrum antibiotics,and Ins hypoglycemic therapy,the re-examination of urinary CT showed that bilateral hydronephrosis,double ureters,and bladder gas disappeared,and the indicators were improved compared with before.Due to the severe condition of the patient with DNB,the residual urine volume of the bladder increased day by day after the catheter was removed,which led to long-term indwelling catheter after discharge.

Objective : To investigate the mechanisms of bromodomain-containing protein 4(BRD4) in TGF-β1-induced epithelial-mesenchymal transition in alveolar type II epithelial cells. Methods : MLE-12 cells were stimulated with different concentrations(5 ng/ml, 10 ng/ml) of TGF-β1 for 48 h to establish an EMT cell model. The cells were pretreated with 50 nmol/L BRD4 inhibitor JQ-1, 100 μmol/L high mobility group box 1 protein(HMGB1)inhibitor glycyrrhizin acid(GA), and 3 μg/ml rHMGB1. The experimental groups were divided as follows: control group, TGF-β1 group, JQ-1 group, JQ-1+TGF-β1 group, GA group, GA+TGF-β1 group, and JQ-1+TGF-β1+rHMGB1 group. The effect of JQ-1 on cell viability was examined using cell counting kit-8(CCK-8). The protein expression levels of CDH1, ZO-1, Vimentin, α-SMA, BRD4, HMGB1, TGF-β1, Smad2/3 and p-Smad2/3 were detected by Western blot. The cell migration ability was detected by a scratch test. Results : Compared with the control group, the levels of Vimentin and α-SMA in the TGF-β1 group increased, and the levels of CDH1 and ZO-1 protein decreased, suggesting that the EMT model was successfully established. In this model, the expression of BRD4 and HMGB1 significantly increased. Different concentrations of JQ-1 could inhibit the cell viability of MLE-12 in a concentration-dependent manner. Both JQ-1 and GA could effectively alleviate TGF-β1-induced EMT, and reduce the increase in HMGB1 expression and the activation of TGF-β1/Smad2/3 pathway caused by TGF-β1. Moreover, rHMGB1 treatment could reduce the effects of JQ-1 on EMT and the TGF-β1/Smad2/3 pathway. Additionally, both JQ-1 and glycyrrhizin could effectively decrease TGF-β1-induced cell migration, whereas rHMGB1 could alleviate the inhibitory effect of JQ-1 on the rate of cell migration. Conclusion BRD4 can regulate epithelial-mesenchymal transition in alveolar type II epithelial cells via HMGB1/TGF-β1/Smad2/3 signaling cascade, and BRD4 may be a potential target for inhibition of pulmonary fibrosis.

Objective:To analyze the risk factors for human cytomegalovirus (HCMV) infection in pediatric recipients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT).Methods:Clinical data of children who underwent first allo-HSCT were retrospectively analyzed from March 2017 to November 2024. A total of 259 pediatric allo-HSCT recipients were analyzed through comparing HCMV infection group (n=115) and Non-HCMV infection group (n=144). Clinical characteristics were compared, and risk factors for HCMV infection were analyzed using univariate and multivariate logistic regression.Results:The result of univariate analysis showed that adrenoleukodystrophy (ALD), length of hospitalization, duration of antiviral therapy, and bacterial infection were significantly associated with HCMV infection in pediatric allo-HSCT recipients ( P<0.05). The result of multivariate analysis showed that ALD was an independent protective factor against HCMV infection of allo-HSCT recipients ( P<0.05) [OR=0.22, 95% CI: 0.06-0.86], while umbilical cord blood transplantation (UCBT) was an independent risk factor for HCMV infection in allo-HSCT recipients ( P<0.05) [OR=6.13, 95% CI: 1.34-28.04]. When the area under the ROC curve (AUC) for predicting post-transplant relapse based on HCMV viral load was 0.75 (95% CI: 0.55-0.94, P=0.014) and at the cutoff value of 3×10 3 copies/ml, the sensitivity and specificity for predicting relapse were 81.13% and 66.67%, respectively. Conclusions:HCMV infection in pediatric allo-HSCT recipients may lead to longer hospitalization and increased risk of relapse.

Objective:To analyze the clinical characteristics and cytokines expression characteristics in infants with mild and severe respiratory syncytial virus (RSV) infection.Methods:From May 2023 to December 2023, plasma samples and clinical information were collected from 16 infants with RSV infection and 14 control infants. Cytek Aurora flow cytometry (Cytek, America) and Enzyme linked immunosorbent assay (ELISA) were used to detect the expression levels of 25 cytokines after mild and severe RSV infection.Results:Cough and nasal obstruction were the main clinical manifestations in infants with mild RSV infection, accompanied by polypnea, wheezing and other symptoms. The main symptoms of severe RSV infection were cough and rales, accompanied by fever and polypnea. In comparison with the control group, the expression levels of IL-2, IL-4, IL-5, IL-6, IL-9, IL-13, IL-22, TNF-α, IFN-α, IFN-β, MIP-1β, I-TAC, ENA-78, GROα, Eotaxin, and MCP-1 in the RSV infection group all exhibited an upregulation trend. Both IP-10 and MIP-3α demonstrated a downward trend in the RSV infection group; however, there was no statistically significant difference ( P>0.05). The levels of IL-10, IFN-γ, MIP-1α, and IL-8 in the RSV infection group were significantly higher than those in the control group, whereas the levels of MIG, TARC, and RANTES in the RSV infection group were significantly lower than those in the control group ( P<0.05). The levels of IL-2, IL-4, IL-5, IL-6, IL-9, IL-10, IL-13, IL-22, IFN-β, IFN-γ, TNF-α, IL-8, I-TAC, MIP-1β, Eotaxin, and MCP-1 in the mild RSV infection group were significantly higher than those in the severe RSV infection group ( P>0.05). Among these, the levels of MIG, RANTES, TARC, MIP-3α, and ENA-78 in the mild infection group were all lower than those in the severe infection group. The expressions of ENA-78 and MIP-1α in the severe infection group were significantly higher than those in the mild infection group and also higher than those in the control group. There was no significant difference in IP-10 and GROα between the mild and severe RSV infection groups ( P>0.05). Conclusions:The differences in clinical features and cytokines between infants with mild and severe RSV infection provide important data support for the prevention and treatment of RSV infection in infants.