Objective:To investigate the factors influencing early recurrence for patients with initially unresectable hepatocellular carcinoma (HCC) who underwent salvage liver resection (SLR) following transcatheter arterial chemoembolization-based downstaging treatment, and construct a predictive model to evaluate its predicting performance.Methods:The retrospective cohort study was constructed. The clinicopathological data of 305 patients with initially unresectable HCC who were admitted to 4 medical centers in China, including the Third Affiliated Hospital of Naval Medical University (Shanghai Eastern Hepatobiliary Surgery Hospital) et al, from January 2019 to December 2021 were collected. There were 286 males and 19 females, aged (48.7±10.4)years. A total of 133 patients who were admitted from January 2019 to December 2020 were set as the training cohort, and the other 172 patients who were admitted from January to December 2021 were set as the validation cohort. Observation indicators: (1) postoperative recurrence-free survival in HCC patients; (2) analysis of factors influencing postoperative early recurrence in HCC patients; (3) construction and validation of the predictive model. Comparison of measurement data with normal distribution between groups was conducted using the independent sample t test. Comparison of count data between groups was conducted using the chi-square test. Comparison of ordinal data was conducted using the rank sum test. Univariate and multivariate analyses were conducted using the Cox regre-ssion model. The Kaplan-Meier method was used to calculate survival. The Log-rank test was used for survival analysis. The predicting performance of the model was evaluated using the concordance index (C-index) and the area under curve (AUC) of time-dependent receiver operating characteristic (ROC) curve, and the accuracy of the model was validated using the calibration curve. The total net gain of the model was evaluated using the decision curve. Results:(1) Postoperative recurrence-free survival in HCC patients. The recurrence-free survival time of 133 HCC patients in the training cohort was 10.0(range, 1.5-24.0)months, with 1-, 2-year recurrence-free survival rate of 47.3% and 36.8%. The recurrence-free survival time of 172 HCC patients in the validation cohort was 11.0(range, 1.0-24.0)months, with 1-, 2-year recurrence-free survival rate of 51.7% and 37.2%. There was no significant difference in recurrence-free survival between patients in the training cohort and the validation cohort ( χ2=0.075, P>0.05). (2) Analysis of factors influencing postoperative early recur-rence in HCC patients. Results of multivariate analysis showed that tumor burden prior to down-staging treatment, grade of albumin-bilirubin (ALBI) score prior to SLR, alpha-fetoprotein (AFP) half-life prior to SLR, and tumor response prior to SLR were independent factors influencing early recurrence in HCC patients after surgery [ hazard ratio=3.212, 2.526, 2.304, 1.575, 95% confidence interal ( CI) as 1.262-8.175, 1.324-4.818, 1.477-3.595, 1.138-2.180, P<0.05]. (3) Construction and validation of the predictive model. A nomogram predictive model for postoperative early recurrence was constructed base on the results of multivariate analysis. The C-index of predictive model was 0.786 for the training cohort and 0.734 for the validation cohort. The AUC of ROC curve of nomogram predictive model for 12-, 18-, and 24-month recurrence-free survival rate in the training cohort were 0.890 (95% CI as 0.836-0.944), 0.895 (95% CI as 0.842-0.947), and 0.887 (95% CI as 0.831-0.942), respectively. The AUC of ROC curve of nomogram predictive model for 12-, 18-, and 24-month recurrence-free survival rate in the validation cohort were 0.845 (95% CI as 0.781-0.909], 0.888 (95% CI as 0.826-0.950), and 0.919 (95% CI as 0.870-0.968), respectively. Results of calibration curve showed high consistency between the predicted results of nomogram predictive model and actual outcomes. Results of decision curve showed the nomogram predictive model with a good total net gain at a threshold of 0.10-0.50. Conclusions:Tumor burden prior to downstaging treatment, grade of ALBI score prior to SLR, AFP half-life prior to SLR, and tumor response prior to SLR are independent factors influencing early recurrence in initially unresectable HCC patients undergoing SLR following downstaging treatment. The nomogram predictive model based on these factors can effectively evaluate the prognosis of this patient population.

Objective To establish a stable liquid chromatography-tandem mass spectrometry(LC-MS/MS)method for detecting gamma-aminobutyric acid(GABA)in plasma,and to evaluate the value of GABA detection in the diagnosis of sleep disorders.Methods GABA was detected using a UPLC Xevo TQs system.The method was pre-validated and its performance was verified to establish a reference range for healthy individuals.The difference in plasma GABA levels between apparently healthy individuals and patients with sleep disorders was compared.Results We employed deuterated compounds as isotopic internal standards and utilized an Amide chromatographic column for separation.The mobile phase was 0.050%formic acid in water and 90%acetonitrile in water containing 0.175%formic acid and 5 mmol/L ammonium acetate with gradient elution in the column temperature of 35℃.The linear range for the detection of GABA by LC-MS/MS was 0.05-10.00 μmol/L,with a lower limit of quantification of 0.02 μmol/L,the inter-day CV<3.00%and intra assay CV<4.00%,respectively,and the recovery rate was 101.06%-109.02%.The reference ranges for plasma GABA were established by analyzing 300 healthy controls stratified by age:18-34 years(0.08-0.15 μmol/L),35-49 years(0.10-0.20 μmol/L),and≥50 years(0.12-0.23 μmol/L).Then plasma GABA was used as a biomarker for auxiliary diagnosis of sleep disorders in analyzing 221 patients and 300 healthy controls,which revealed that AUC values were 0.510(P=0.850),0.686(P=0.002),and 0.890(P<0.001)in the groups of 18-34 years,35-49 years,and≥50 years,respectively,with optimal cut-off values of 0.09,0.10 and 0.11 μmol/L.Conclusion A reliable LC-MS/MS method for detecting GABA has been established,which can detect plasma GABA levels sensitively and accurately and can be used in assisting the clinical diagnosis of sleep disorders.

Objective To detect the expression level of serum LncRNA P53RRA in patients with primary hepatocellular carcinoma(HCC)and explore its clinical application value in the diagnosis of HCC.Methods Ninety-three patients with primary HCC visited Zhongshan Hospital Affiliated to Fudan University from November 2019 to December 2020 were selected as the HCC group and 88 healthy individuals undergone physical examination as the control group.Their serum samples were collected and the expression levels of serum LncRNA P53RRA were detected by real-time fluorescence quantitative PCR(qRT-PCR).The correlations of serum P53RRA levels with clinicopathological parameters and clinical biochemical indicators such as alanine aminotransferase(ALT),glutamate amin-otransferase(AST),gamma-glutamyl transpeptidase(GGT),and alkaline phosphatase(ALP)in HCC patients were analyzed.The diagnostic value of serum P53RRA for HCC was evaluated by the receiver operating characteristic(ROC)curve.Results The expres-sion levels of serum P53RRA in HCC patients(2.15±0.22)were significantly lower than that in healthy controls(3.54±0.33),and the difference was statistically significant(t=3.489,P＜0.05).The analysis of clinicopathological parameters showed that the expres-sion levels of serum P53RRA in HCC patients were correlated with tumor staging(χ2=9.590,P＜0.05),α-fetoprotein(AFP,χ2=5.732,P＜0.05),and GGT(χ2=5.732,P＜0.05).ROC curve analysis showed that the area under the ROC curve(AUCROC)of ser-um P53RRA in the diagnosis of HCC was 0.750(95%CI:0.679-0.821),with a sensitivity of 65.6%and specificity of 64.8%.The AUCROC,sensitivity and specificity of P53RRA combined with AFP and GGT in the diagnosis of HCC were 0.911(95%CI:0.867-0.953),88.2%and 70.5%,respectively,which were higher than those of single indicator.Conclusion LncRNA P53RRA is expec-ted to serve as a novel non-invasive biomarker,effectively assisting in the clinical diagnosis of HCC.

OBJECTIVE To evaluate the value of matrix-assisted laser desorption ionization time-of-flight-mass spectrometry(MALDI-TOF MS)in direct identification of carbapenem-resistant Escherichia coli and Klebsiella pneumoniae positive for blood culture.METHODS The blood culture bottles that were positive for E.coli or K.pneumoniae were collected from the patients with bloodstream infection who were treated in Zhongshan Hospi-tal,Fudan University from Jul.2021 to Jun.2023.The isolates were collected by using a gel-contact clotting tube,then the tested strains were respectively mixed with 4 μg/ml of imipenem,4 μg/ml of meropenem and 2 μg/ml of ertapenem for coculture and were incubated at 35 ℃ for 4 and 5 hours,finally,the strains were i-dentified by using the mass spectrum.The minimum inhibitory concentrations(MICs)of the three types of drugs were tested by microbroth dilution method and were set as the golden standards for the test.RESULTS Totally 31 strains of E.coli and 28 strains of K.pneumoniae that were positive in blood culture bottles were collected,both of the effective rates of controlled growth of the E.coli strains were 100.00％after the incuba-tion for 4 and 5 hours,and the effective rates of controlled growth of the K.pneumoniae strains were 9 6.43％and 100.00％after the incubation for 4 and hours,respectively.The sensitivity,specificity,positive predictive value and negative predictive value of the K.pneumoniae strains against the three types of drugs were 100.00％after the incubation for 5 hours.The specificity and positive predictive value of the E.coli strains against imipenem,meropenem and ertapenem were 100.00％after the incubation for 5 hours;the sensitivities were 73.58％,78.93％and 78.93％,respectively;the negative predictive values were 70.60％,75.00％and 75.00％,respectively.CONCLUSIONS MALDI-TOF MS is rapid and accurate for direct identification of the carbapenem-resistant E.coli and K.pneumoniae strains positive in blood culture bottles,and the accuracy reaches at 100.00％for the test of drug-resistant K.pneumoniae strains after the incubation for 5 hours.The method may provide evidence for clinical treatment of bloodstream infections induced by carbapenem-resistant Enterobacteriaceae.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective To construct an animal model of dilated cardiomyopathy(DCM)with heart failure toxin syndrome that conforms to the characteristics of traditional Chinese medicine(TCM)syndrome and identify potential biomarkers or intervention targets for DCM with heart failure toxin syndrome.Methods Fifteen male SD rats were divided into a blank control,doxorubicin,or DCM with heart failure toxin syndrome group using a random number table method,with five rats per group.The doxorubicin group received intraperitoneal injection of doxorubicin at a dose of 1.25 mg/kg,administered on the first and fourth days of each week,along with a standard diet.The DCM with heart failure toxin syndrome group,in addition to the doxorubicin treatment,was given 42％white liquor(10 mL/kg)via gavage every other day,along with a 45％high-fat feed and 10％fructose water.The blank control group received intraperitoneal injection of an equivalent volume of phosphate-buffered saline at the same time points as the doxorubicin group,along with a standard diet.The model was established for 10 weeks.At the fourth and tenth weeks of modeling,echocardiography was performed to measure left ventricular ejection fraction(LVEF),fractional shortening(FS),systolic left ventricular posterior wall thickness(LVPWs),diastolic left ventricular posterior wall thickness,systolic left ventricular internal diameter(LVIDs),and diastolic left ventricular internal diameter(LVIDd);macroscopic changes in fur color of the rats were assessed using the red-green-blue colorimetric method.After modeling,the open field test was conducted to evaluate the exercise tolerance of the rats,and the grip strength test was performed to assess changes in forelimb grip strength.Hematoxylin-eosin,Masson,and wheat germ agglutinin staining were used to evaluate pathological changes in cardiac tissue.Bulk RNA sequencing analysis was performed to identify differentially expressed genes(DEGs)in the hearts of rats between the blank control and the DCM with heart failure toxin syndrome groups.Using DCM,the Blue value of rat fur color,and forelimb grip strength as phenotypic traits,weighted gene co-expression network analysis(WGCNA)was performed to screen for characteristic module gene sets(MEs)associated with DCM with heart failure toxin syndrome.Overlapping analysis was performed on DEGs,immune-related gene sets,and MEs,and the intersecting genes were identified as potential biomarkers or intervention targets for DCM with heart failure toxin syndrome.The sensitivity and specificity of these targets were evaluated using receiver operating characteristic(ROC)curve analysis.Results Compared with the blank control group,at the tenth week of modeling,the LVEF,FS,and LVPWs of rats in the doxorubicin group and the DCM with heart failure toxin syndrome group decreased,whereas LVIDs and LVIDd increased,and the movement distance of the open field test and forelimb grip strength were reduced(P＜0.05).At the 10th week of modeling,the Blue value of fur color in the DCM with heart failure toxin syndrome group was significantly lower than that of the blank control and doxorubicin groups(P＜0.05).Compared with the blank control group,rats in the doxorubicin and DCM with heart failure toxin syndrome groups exhibited significant cardiac dilation and increased immune cell infiltration in cardiac tissue,accompanied by collagen deposition and cardiomyocyte hypertrophy.Bulk RNA sequencing identified 2,003 DEGs,including 1,082 downregulated genes and 921 upregulated genes.WGCNA results revealed that the MEturquoise module had the strongest positive correlation with DCM and the strongest negative correlation with the Blue value and forelimb grip strength.The overlapping analysis identified four intersecting genes:bone morphogenetic protein 6(Bmp6),serine-threonine-protein kinase 1(Pak1),proto-oncogene JunD(JunD),and S100 calcium-binding protein A3(S100A3).ROC curve analysis demonstrated that these four genes exhibited high sensitivity and specificity for DCM with heart failure toxin syndrome.Conclusion The rat model constructed by intraperitoneal injection of doxorubicin combined with a high-fat feed,fructose water,and white liquor gavage closely aligns with the characteristics of the DCM with heart failure toxin syndrome.Bmp6,JunD,Pak1,and S100A3 are potential biomarkers or therapeutic targets for DCM heart failure toxin syndrome.

Objective:To investigate the factors influencing early recurrence for patients with initially unresectable hepatocellular carcinoma (HCC) who underwent salvage liver resection (SLR) following transcatheter arterial chemoembolization-based downstaging treatment, and construct a predictive model to evaluate its predicting performance.Methods:The retrospective cohort study was constructed. The clinicopathological data of 305 patients with initially unresectable HCC who were admitted to 4 medical centers in China, including the Third Affiliated Hospital of Naval Medical University (Shanghai Eastern Hepatobiliary Surgery Hospital) et al, from January 2019 to December 2021 were collected. There were 286 males and 19 females, aged (48.7±10.4)years. A total of 133 patients who were admitted from January 2019 to December 2020 were set as the training cohort, and the other 172 patients who were admitted from January to December 2021 were set as the validation cohort. Observation indicators: (1) postoperative recurrence-free survival in HCC patients; (2) analysis of factors influencing postoperative early recurrence in HCC patients; (3) construction and validation of the predictive model. Comparison of measurement data with normal distribution between groups was conducted using the independent sample t test. Comparison of count data between groups was conducted using the chi-square test. Comparison of ordinal data was conducted using the rank sum test. Univariate and multivariate analyses were conducted using the Cox regre-ssion model. The Kaplan-Meier method was used to calculate survival. The Log-rank test was used for survival analysis. The predicting performance of the model was evaluated using the concordance index (C-index) and the area under curve (AUC) of time-dependent receiver operating characteristic (ROC) curve, and the accuracy of the model was validated using the calibration curve. The total net gain of the model was evaluated using the decision curve. Results:(1) Postoperative recurrence-free survival in HCC patients. The recurrence-free survival time of 133 HCC patients in the training cohort was 10.0(range, 1.5-24.0)months, with 1-, 2-year recurrence-free survival rate of 47.3% and 36.8%. The recurrence-free survival time of 172 HCC patients in the validation cohort was 11.0(range, 1.0-24.0)months, with 1-, 2-year recurrence-free survival rate of 51.7% and 37.2%. There was no significant difference in recurrence-free survival between patients in the training cohort and the validation cohort ( χ2=0.075, P>0.05). (2) Analysis of factors influencing postoperative early recur-rence in HCC patients. Results of multivariate analysis showed that tumor burden prior to down-staging treatment, grade of albumin-bilirubin (ALBI) score prior to SLR, alpha-fetoprotein (AFP) half-life prior to SLR, and tumor response prior to SLR were independent factors influencing early recurrence in HCC patients after surgery [ hazard ratio=3.212, 2.526, 2.304, 1.575, 95% confidence interal ( CI) as 1.262-8.175, 1.324-4.818, 1.477-3.595, 1.138-2.180, P<0.05]. (3) Construction and validation of the predictive model. A nomogram predictive model for postoperative early recurrence was constructed base on the results of multivariate analysis. The C-index of predictive model was 0.786 for the training cohort and 0.734 for the validation cohort. The AUC of ROC curve of nomogram predictive model for 12-, 18-, and 24-month recurrence-free survival rate in the training cohort were 0.890 (95% CI as 0.836-0.944), 0.895 (95% CI as 0.842-0.947), and 0.887 (95% CI as 0.831-0.942), respectively. The AUC of ROC curve of nomogram predictive model for 12-, 18-, and 24-month recurrence-free survival rate in the validation cohort were 0.845 (95% CI as 0.781-0.909], 0.888 (95% CI as 0.826-0.950), and 0.919 (95% CI as 0.870-0.968), respectively. Results of calibration curve showed high consistency between the predicted results of nomogram predictive model and actual outcomes. Results of decision curve showed the nomogram predictive model with a good total net gain at a threshold of 0.10-0.50. Conclusions:Tumor burden prior to downstaging treatment, grade of ALBI score prior to SLR, AFP half-life prior to SLR, and tumor response prior to SLR are independent factors influencing early recurrence in initially unresectable HCC patients undergoing SLR following downstaging treatment. The nomogram predictive model based on these factors can effectively evaluate the prognosis of this patient population.

Objective To evaluate the impact of setting a 4-day incubation time on the detection performance of bloodstream infection(BSI)pathogens by the BacTALERT VIRTUO blood culture system(VIRTUO).Methods Retrospectively collecting blood culture(BC)results from Zhongshan Hospital,Fudan University,from June 2021 to December 2023,and comparing the time-to-detection for clinically significant microorganisms.Results A total of 87 052 BC bottles were collected,of which 7 167(8.23%)were positive.95%of aerobic and anaerobic bottles were reported positive at 65.67 h and 91.2 h respectively.The average(median)time-to-detection for Staphylococcus aureus(S.aureus)was 21.76(16.08)h,Klebsiella pneumoniae(KP)was 15.32(11.65)h,Escherichia coli(E.coli)was 16.14(10.87)h,and Candida species was 35.2(28.5)h.Only 213 bottles(0.24%)were reported positive after 4 days of incubation;among them,88 bottles(41.31%)cultured Propionibacterium acnes(P.acnse).Medical chart reviews for BC reported positive after 96 h(4 days)showed no clinical significance.Simulated growth experiments were conducted on 11 fastidious bacteria,and the median detection time was only 10.8 h,indicating that an incubation time of 4 days is sufficient for fastidious bacteria.Conclusion A 4-day incubation is adequate for VIRTUO system.Reporting 1 day earlier to the doctors can reduce the positive rate of contaminants and the use of antimicrobial agents.

Objective To establish a stable liquid chromatography-tandem mass spectrometry(LC-MS/MS)method for detecting gamma-aminobutyric acid(GABA)in plasma,and to evaluate the value of GABA detection in the diagnosis of sleep disorders.Methods GABA was detected using a UPLC Xevo TQs system.The method was pre-validated and its performance was verified to establish a reference range for healthy individuals.The difference in plasma GABA levels between apparently healthy individuals and patients with sleep disorders was compared.Results We employed deuterated compounds as isotopic internal standards and utilized an Amide chromatographic column for separation.The mobile phase was 0.050%formic acid in water and 90%acetonitrile in water containing 0.175%formic acid and 5 mmol/L ammonium acetate with gradient elution in the column temperature of 35℃.The linear range for the detection of GABA by LC-MS/MS was 0.05-10.00 μmol/L,with a lower limit of quantification of 0.02 μmol/L,the inter-day CV<3.00%and intra assay CV<4.00%,respectively,and the recovery rate was 101.06%-109.02%.The reference ranges for plasma GABA were established by analyzing 300 healthy controls stratified by age:18-34 years(0.08-0.15 μmol/L),35-49 years(0.10-0.20 μmol/L),and≥50 years(0.12-0.23 μmol/L).Then plasma GABA was used as a biomarker for auxiliary diagnosis of sleep disorders in analyzing 221 patients and 300 healthy controls,which revealed that AUC values were 0.510(P=0.850),0.686(P=0.002),and 0.890(P<0.001)in the groups of 18-34 years,35-49 years,and≥50 years,respectively,with optimal cut-off values of 0.09,0.10 and 0.11 μmol/L.Conclusion A reliable LC-MS/MS method for detecting GABA has been established,which can detect plasma GABA levels sensitively and accurately and can be used in assisting the clinical diagnosis of sleep disorders.