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.

Chronic pancreatitis is a chronic inflammatory disease characterized by progre-ssive fibrosis of pancreatic tissue. Its pathological features primarily include parenchymal fibrosis, intraductal stone formation or calcification deposits, as well as segmental stenosis and dilation of the pancreatic duct. Prolonged chronic inflammatory stimulation not only leads to progressive pancreatic dysfunction but may also trigger the formation of pancreatic pseudocysts and even malignant transformation. In the comprehensive treatment of chronic pancreatitis, the core clinical goals are the removal of pancreatic duct stones, restoration of unobstructed pancreatic duct drainage, and preservation of residual pancreatic function. Traditional treatment strategies have been based on the principle of progressive intervention and early surgical management. In recent years, with advancements in extracorporeal shock wave lithotripsy, the application of new techniques such as endoscopic retrograde cholangiopancreatography combined with laser lithotripsy under direct cholan-gioscopic visualization, and improvements in pancreas-preserving surgical approaches, the debate over the superiority of progressive intervention versus early surgical treatment has intensified. Against this backdrop, the treatment mode of Xi′an Jiaotong University Pancreatic Disease Center (hereinafter referred to as "Western Pancreas") has emerged, emphasizing a personalized, multimodal treatment strategy based on different types of pancreatic duct stones. The treatment mode of "Western Pancreas" integrates lithotripsy, endoscopic treatment, and surgical interventions to optimize patient outcomes. By conducting a comprehensive analysis of domestic and international pancreatic duct stone classi-fication systems and drawing from our team′s clinical experience in managing over a thousand cases of chronic pancreatitis, the authors have further refined and proposed a classification system for pancreatic duct stones under the treatment mode of "Western Pancreas". This refinement aims to enhance the overall diagnostic and therapeutic standards for chronic pancreatitis.

Objective:To detect the levels of sex hormones and insulin in follicular fluid(FF)and the expression level of phosphatase and tensin homolog deleted on chromosome ten(PTEN)in granulosa cells in the infertile patients with polycystic ovary syndrome(PCOS),and to preliminarily explain the correlations between the insulin level and the expression level of PTEN mRNA.Methods:Seventy infertile patients were selected as the subjects and divided into PCOS group and control group(tubal obstruction or infertility due to male factors)according to infertility factors.All patients received in vitro fertilization-embryo transfer(IVF-ET)treatment.FF and ovarian granulosa cells were collected on the day of ovulation.The expression levels of PTEN mRNA in ovarian granulosa cells of the patients in two groups were detected by real-time fluorescence quantitative PCR(RT-qPCR)method.The levels of sex hormone and insulin in FF were measured by electrochemiluminescence.The correlations of the PTEN mRNA expression level in ovarian granulosa cells and testosterone(T)in FF with the level of insulin in FF were analyzed by Spearman correlation analysis method.Results:There were no significant differences in age,infertility years,body mass index(BMI),basic sex hormone,total dose of gonadotropin(Gn)and days of ovulation induction in two groups(P＞0.05).Compared with control group,the anti-Mullerian hormone(AMH)and antral follicle counting(AFC)of the patients in PCOS group were significantly increased(P＜0.05).The RT-qPCR results showed that the PTEN mRNA expression level in ovarian granulosa cells of the patients in the PCOS group was higher than that in control group(P＜0.001).The electrochemiluminescence results showed that the levels of T and insulin in FF of the patients in PCOS group were higher than those in control group(P＜0.05),whereas the estrogen and progesterone levels were lower than those in control group(P＜0.05).The Spearman correlation analysis showed that that T level in FF was positively correlated with the insulin level of the patients in PCOS group(r=0.577,P＜0.001),and the PTEN mRNA expression level in ovarian granulosa cells was positively correlated with the insulin levels in FF(r=0.616,P＜0.001);in control group,there was no correlation between T level and insulin level in FF(r=0.266,P=0.123),and there was no correlation between the expression level of PTEN mRNA in granulosa cells and the insulin level in FF in control group(r=-0.214,P=0.216).Conclusion:The high expression of PTEN in granulosa cells of the infertile patients with PCOS may be related to the local hyperinsulin level in the ovary,and PTEN participates in the occurrence and development of PCOS.

Objective:To analyze the clinical characteristics and treatment outcomes of children with anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (anti-HMGCR) antibody-mediated necrotizing myopathy, and to explore early identification and management strategies to provide reference for clinical diagnosis and treatment.Methods:A retrospective analysis was conducted on the clinical data and treatment outcomes of 10 pediatric patients with anti-HMGCR antibody-mediated necrotizing myopathy admitted to the Department of Rheumatology, Children′s Hospital of Fudan University from December 2020 to December 2024. Statistical description was performed using SPSS 22.0.Results:Among the 10 patients, the male-to-female ratio was 1:4, the age of onset was (7.2±4.0) years, and the disease duration at diagnosis was (22.2±19.6) months. None had a history of statin exposure. Six patients presented with muscle weakness, and4 were diagnosed due to asymptomatic elevation of creatine kinase (CK); 4 had dermatomyositis-like rashes. All patients showed significantly elevated CK levels [median 3 291(1 969, 8 776)U/L] and underwent muscle biopsy. Histopathological findings revealed myofiber degeneration, necrosis, and regeneration in all cases, with inflammatory infiltration in 9 cases, MHC-Ⅰ positivity in all, and C5b-9 positivity in 9 cases. The median follow-up duration was (15.7±6.3) months. At the last follow-up, muscle strength was normal or nearly normal, and the CK median value had decreased to 977.5 (211.0, 3 536.0) U/L.Conclusion:For patients with suspected idiopathic inflammatory myopathy and significantly elevated CK, muscle-specific antibody testing-including anti-HMGCR-and muscle biopsy should be performed promptly regardless of the presence of skin rash, to ensure accurate diagnosis and guide treatment, thereby avoiding misdiagnosis or missed diagnosis.

Objective:To investigate the clinical characteristics and independent risk factors of severe disease in patients with anti-nuclear matrix protein (NXP) 2 antibody-positive juvenile dermatomyositis (JDM).Methods:A retrospective cohort study was conducted, including 219 anti-NXP2 antibody-positive JDM patients admitted to 23 children′s hospitals across China from July 2011 to July 2023. Patients were classified into severe and non-severe groups based on classification criteria for severe dermatomyositis. Demographic characteristics, clinical manifestations, and laboratory parameters were compared between the 2 groups using independent sample t-test, Mann-Whitney U test, or χ2 test. Univariate and multivariate Logistic regression analyses were performed to identify risk factors for severe disease. The receiver operating characteristic curve was employed to calculate optimal cut-off values. Results:Among the 219 patients, 108 were male and 111 were female, with an age at onset of 6.3 (3.5, 9.4) years. The severe group comprised 69 patients, and the non-severe group 150 patients. The severe group had significantly higher rates of fever, heliotrope rash, subcutaneous edema, periorbital edema, anti-Ro52 antibody positivity, as well as elevated levels of ferritin-to-albumin ratio (FAR), creatine kinase (CK), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) (all P<0.05). Multivariate analysis identified anti-Ro52 antibody positivity ( OR=13.26, 95% CI 1.37-128.29) and elevated FAR ( OR=1.90, 95% CI 1.09-2.31) as independent risk factors for severe anti-NXP2 antibody-positive JDM (both P<0.05). Receiver operating characteristic curve analysis revealed that a FAR cutoff value of 6.82 predicted severe disease with an area under the curve of 0.87 (95% CI 0.81-0.94, P<0.001), sensitivity of 0.85, and specificity of 0.70. All patients received glucocorticoid therapy, and the severe group received higher proportions of steroid pulse therapy, cyclophosphamide, mycophenolate mofetil, intravenous immunoglobulin, biologics, and adjuvant treatments compared to the non-severe group (all P<0.05). In terms of outcomes, 2 patients (2.9%) in the severe group died (due to neurological involvement and intestinal perforation, respectively), while the remaining patients achieved complete clinical response or remission. All patients in the non-severe group achieved remission. Conclusions:The primary clinical features of anti-NXP2 antibody-positive JDM included fever, heliotrope rash, subcutaneous edema, periorbital edema, anti-Ro52 antibody positivity, and elevated levels of CK, AST, LDH, and FAR. Furthermore, anti-Ro52 antibody positivity and a FAR>6.82 were identified as independent risk factors.

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.

Chronic pancreatitis is a chronic inflammatory disease characterized by progre-ssive fibrosis of pancreatic tissue. Its pathological features primarily include parenchymal fibrosis, intraductal stone formation or calcification deposits, as well as segmental stenosis and dilation of the pancreatic duct. Prolonged chronic inflammatory stimulation not only leads to progressive pancreatic dysfunction but may also trigger the formation of pancreatic pseudocysts and even malignant transformation. In the comprehensive treatment of chronic pancreatitis, the core clinical goals are the removal of pancreatic duct stones, restoration of unobstructed pancreatic duct drainage, and preservation of residual pancreatic function. Traditional treatment strategies have been based on the principle of progressive intervention and early surgical management. In recent years, with advancements in extracorporeal shock wave lithotripsy, the application of new techniques such as endoscopic retrograde cholangiopancreatography combined with laser lithotripsy under direct cholan-gioscopic visualization, and improvements in pancreas-preserving surgical approaches, the debate over the superiority of progressive intervention versus early surgical treatment has intensified. Against this backdrop, the treatment mode of Xi′an Jiaotong University Pancreatic Disease Center (hereinafter referred to as "Western Pancreas") has emerged, emphasizing a personalized, multimodal treatment strategy based on different types of pancreatic duct stones. The treatment mode of "Western Pancreas" integrates lithotripsy, endoscopic treatment, and surgical interventions to optimize patient outcomes. By conducting a comprehensive analysis of domestic and international pancreatic duct stone classi-fication systems and drawing from our team′s clinical experience in managing over a thousand cases of chronic pancreatitis, the authors have further refined and proposed a classification system for pancreatic duct stones under the treatment mode of "Western Pancreas". This refinement aims to enhance the overall diagnostic and therapeutic standards for chronic pancreatitis.

Objective:To analyze the clinical characteristics and treatment outcomes of children with anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (anti-HMGCR) antibody-mediated necrotizing myopathy, and to explore early identification and management strategies to provide reference for clinical diagnosis and treatment.Methods:A retrospective analysis was conducted on the clinical data and treatment outcomes of 10 pediatric patients with anti-HMGCR antibody-mediated necrotizing myopathy admitted to the Department of Rheumatology, Children′s Hospital of Fudan University from December 2020 to December 2024. Statistical description was performed using SPSS 22.0.Results:Among the 10 patients, the male-to-female ratio was 1:4, the age of onset was (7.2±4.0) years, and the disease duration at diagnosis was (22.2±19.6) months. None had a history of statin exposure. Six patients presented with muscle weakness, and4 were diagnosed due to asymptomatic elevation of creatine kinase (CK); 4 had dermatomyositis-like rashes. All patients showed significantly elevated CK levels [median 3 291(1 969, 8 776)U/L] and underwent muscle biopsy. Histopathological findings revealed myofiber degeneration, necrosis, and regeneration in all cases, with inflammatory infiltration in 9 cases, MHC-Ⅰ positivity in all, and C5b-9 positivity in 9 cases. The median follow-up duration was (15.7±6.3) months. At the last follow-up, muscle strength was normal or nearly normal, and the CK median value had decreased to 977.5 (211.0, 3 536.0) U/L.Conclusion:For patients with suspected idiopathic inflammatory myopathy and significantly elevated CK, muscle-specific antibody testing-including anti-HMGCR-and muscle biopsy should be performed promptly regardless of the presence of skin rash, to ensure accurate diagnosis and guide treatment, thereby avoiding misdiagnosis or missed diagnosis.

Objective:To investigate the clinical characteristics and independent risk factors of severe disease in patients with anti-nuclear matrix protein (NXP) 2 antibody-positive juvenile dermatomyositis (JDM).Methods:A retrospective cohort study was conducted, including 219 anti-NXP2 antibody-positive JDM patients admitted to 23 children′s hospitals across China from July 2011 to July 2023. Patients were classified into severe and non-severe groups based on classification criteria for severe dermatomyositis. Demographic characteristics, clinical manifestations, and laboratory parameters were compared between the 2 groups using independent sample t-test, Mann-Whitney U test, or χ2 test. Univariate and multivariate Logistic regression analyses were performed to identify risk factors for severe disease. The receiver operating characteristic curve was employed to calculate optimal cut-off values. Results:Among the 219 patients, 108 were male and 111 were female, with an age at onset of 6.3 (3.5, 9.4) years. The severe group comprised 69 patients, and the non-severe group 150 patients. The severe group had significantly higher rates of fever, heliotrope rash, subcutaneous edema, periorbital edema, anti-Ro52 antibody positivity, as well as elevated levels of ferritin-to-albumin ratio (FAR), creatine kinase (CK), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) (all P<0.05). Multivariate analysis identified anti-Ro52 antibody positivity ( OR=13.26, 95% CI 1.37-128.29) and elevated FAR ( OR=1.90, 95% CI 1.09-2.31) as independent risk factors for severe anti-NXP2 antibody-positive JDM (both P<0.05). Receiver operating characteristic curve analysis revealed that a FAR cutoff value of 6.82 predicted severe disease with an area under the curve of 0.87 (95% CI 0.81-0.94, P<0.001), sensitivity of 0.85, and specificity of 0.70. All patients received glucocorticoid therapy, and the severe group received higher proportions of steroid pulse therapy, cyclophosphamide, mycophenolate mofetil, intravenous immunoglobulin, biologics, and adjuvant treatments compared to the non-severe group (all P<0.05). In terms of outcomes, 2 patients (2.9%) in the severe group died (due to neurological involvement and intestinal perforation, respectively), while the remaining patients achieved complete clinical response or remission. All patients in the non-severe group achieved remission. Conclusions:The primary clinical features of anti-NXP2 antibody-positive JDM included fever, heliotrope rash, subcutaneous edema, periorbital edema, anti-Ro52 antibody positivity, and elevated levels of CK, AST, LDH, and FAR. Furthermore, anti-Ro52 antibody positivity and a FAR>6.82 were identified as independent risk factors.

Objective This study investigated whether gut microbiota and its metabolites are altered in myasthenia gravis(MG)patients.Methods We collected fresh stool specimens from MG patients and healthy controls.16S rRNA gene sequencing and gas chromatography-mass spectrometry were used to measure abundance of gut microbiota and metabolite levels in two groups,respectively.Clinical data of the subjects were also collected including quantitative MG score(QMGS),MG-activities of daily living(MG-ADL),MG-specific quality-of-life 15(MG-QOL15),manual muscle testing(MMT),and the acetylcholine receptor antibody(AchR-Ab)titers.The correlation between the differential microbiota and the clinical characteristics was investigated.Results A total of 50 MG patients and 15 healthy controls were recruited.Simpson's index was significantly higher in the MG group(0.936±0.041)than in the control group(0.888±0.123).Alpha diversity was significantly decreased in the MG group(t=2.349,P=0.022).There was a significant difference in microbial phenotype between the two groups(R=0.966,P=0.001,Adonis).The results of LEfSe showed that the abundance of Esherichia-Shigella,Succinivibrio,Fusobacterium,and Ruminococcus-gnavus-group were up-regulated while the abundance of Lachnospira,Roseburia,Desulfovibrio,and Coprococcus were down-regulated.The results showed that the metabolites of the MG group were significantly different from those of the control group.There were 28 metabolites up-regulated and 71 metabolites down-regulated in the MG patient group.Kyoto Encyclopedia of Genes and Genomes analyses demonstrated that the majority of metabolic pathways in which differential metabolites were involved were related to amino acid metabolism and nucleotide metabolism.61.2% (30/49)of bacterial amplicon sequence variant(ASV)were significantly associated with multiple metabolites(P<0.001).The relative abundance of Lachnospiraceae in the group with MG was negatively correlated with the QMGS(r=-0.496,P<0.001),MG-ADL(r=-0.542,P<0.001),MG-QOL15(r=-0.464,P=0.007),and the AchR-Ab(r=-0.315,P=0.026).The relative abundance of Lachnospiraceae in the group with MG was positively correlated with the MMT(r=0.374,P=0.008).Conclusion The intestinal flora of MG patients is down-regulated in the abundance of beneficial bacteria and up-regulated in the abundances of harmful bacteria.Disturbance of metabolites are also present in MG patients.Regulating gut microbiota in MG patients may be a new target for treating the disease.