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Introducción. La eficiencia de una metodología para analizar una sustancia farmacológica puede verse afectada por las condiciones reales del laboratorio de cada país, incluyendo el clima. Por esta razón, se requiere validar el método con las pautas recomendadas para ello y optimizar el proceso, para asegurar el éxito y la confianza en los resultados. Objetivo. Validar una metodología para la cuantificación simultánea del fluconazol (materia prima) y sus impurezas orgánicas mediante cromatografía líquida de alta resolución con detector de arreglo de diodos en condiciones de clima tropical y con todos los requisitos normativos. Materiales y métodos. Se hicieron pruebas previas a la validación del método: idoneidad del sistema, estudio de filtros, límite de cuantificación, ausencia del error sistemático, estudios de degradación forzada y estabilidad de las soluciones. Además, se validaron: la especificidad, la linealidad, la exactitud, la precisión y la robustez. Resultados. La pureza espectral del método se logró al obtener la separación de los productos de degradación de los picos de los analitos. La estabilidad de las soluciones no se vio afectada, en la frecuencia evaluada de 24 horas, a temperatura ambiente y de refrigeración. Se obtuvo una linealidad con coeficientes de correlación mayores o iguales a 0,999 para la valoración y mayores o iguales a 0,997 para las impurezas. La recuperación estuvo en el rango de 98 a 102,0 % de fluconazol, con una exactitud entre el 80 y el 120 % para las impurezas. El factor de repetibilidad y reproducibilidad no superó la desviación estándar relativa del 2,0 % para la valoración y, la del 5,0 %, para las impurezas, lo cual mostró una solidez adecuada del método. Además, se obtuvo un tiempo corto de ejecución del análisis, lo que permitió la rápida determinación de la calidad de la materia prima. Conclusión. Se demostró que el método de cuantificación de fluconazol, validado por cromatografía líquida de alta resolución con detector de arreglo de diodos, es lo suficientemente selectivo, preciso, exacto, lineal y robusto; además, es capaz de generar resultados analíticos veraces en condiciones de uso reales, incluyendo el clima tropical de Colombia.
Introduction. The real laboratory conditions of each country, including climate, can affect the method's efficiency in analyzing a pharmacological substance. Thus, it is necessary to validate the process according to the corresponding guidelines and optimize it to ensure success and confidence in the results. Objective. The objective was to validate a methodology for fluconazole and its organic impurities quantification in raw material using high-performance liquid chromatography, with a diode array detector, under tropical climate conditions, and complying with all regulatory requirements. Materials and methods. We performed pre-validation tests of the method consisting of system adequacy, filters study, quantification limit, absence of systematic error, forced degradation studies, and solutions stability. In addition, we validated the specificity, linearity, accuracy, precision, and robustness of the system. Results. Separation of the degradation products from the analyte peaks allowed the achievement of the method's spectral purity. The solution's stability was not affected during the evaluated time (24 hours) at room temperature and under refrigeration. Linearity resulted in correlation coefficients greater than or equal to 0.999 for the evaluation and greater than or equal to 0.997 for impurities. We obtained a fluconazole recovery varying from 98 to 102% with an accuracy between 80 to 120% for impurities detection. The repeatability and reproducibility factor did not exceed a relative standard deviation of 2.0% for the evaluation and of 5.0% for the impurities, demonstrating the adequate robustness of the method. In addition, a short analysis execution time allowed the quick determination of the raw material quality. Conclusion. We demonstrated that the fluconazole quantification method validated by high-performance liquid chromatography is sufficiently selective, precise, exact, linear, and robust to generate accurate analytical results under real conditions, including the tropical climate of Colombia.
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Objective:To establish and validate a reliable and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the detection of 12 ceramides in human plasma.Methods:From October 2021 to October 2022, 438 apparently healthy individuals were enrolled in the Affiliated Hospitals of Zunyi Medical University for reference intervals of 12 ceramides in this population. Plasma samples were collected, and separated using the ACQUITY UPLC BEH C18 (2.1×50 mm, 1.7 μm) column, deuterated isotopes were used as internal standards. The mobile phase is water (containing 0.1% formic acid) and isopropanol: acetonitrile (1∶1, v/v, containing 0.1% formic acid) at a flow rate of 0.4 ml/min with gradient elution. The detection method was established using the Qlife Lab 9000 Plus triple quadrupole mass spectrometer. The performance of the method was evaluated in terms of linearity, the lower limit of quantification, precision, recovery, and stability.Results:The method passed the performance evaluation in terms of linearity, the lower limit of quantification, recovery, precision, and stability. The intra-and inter-batch precision of the 12 ceramides ranged from 1.3% to 14.3%, the correctness was verified by spiked recovery experiments, and the recoveries ranged from 91.9% to 111.0%. The lower limit of quantification ranged from 0.001 to 0.100 μmol/L. Standard curve showed good linearity (correlation coefficient r>0.990). Stability tests showed that the 12 ceramides were stable in the biological matrix and after processing under different conditions for a specified period of time. The corresponding biological reference intervals were established for each of the 12 ceramides: 0.103-0.326 μmol/L for Cer(d18∶1/16∶0), 0.018-0.098 μmol/L for Cer(d18∶1/18∶0), 0.933-3.919 μmol/L for Cer(d18∶1/24∶0), 0.243-1.072 μmol/L for Cer(d18∶1/24∶1), 0.001-0.007 μmol/L for Cer(d18∶1/14∶0), 0.022-0.095 μmol/L for Cer(d18∶1/20∶0), 0.185-0.835 μmol/L for Cer(d18∶1/22∶0), 0.003-0.022 μmol/L for Cer(d18∶0/16∶0), 0.001-0.016 μmol/L for Cer(d18∶0/18∶0), 0.017-0.156 μmol/L for Cer(d18∶0/24∶0), 0.008-0.074 μmol/L for Cer(d18∶0/24∶1), and 0.106-0.721 μmol/L for LacCer(d18∶1/24∶1). Conclusion:Our study shows that the newly established LC-MS/MS method for the determination of 12 ceramides in human plasma is reliable, and suitable for clinical application.
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Objective:To establish and validate an LC-MS/MS method for simultaneous determination of Aβ 1-42, Aβ 1-40, and Aβ 1-38 in cerebrospinal fluid. Additionally, the consistency between this method and three mainstream detection methods was evaluated.Methods:This study involved method establishment, validation, and consistency evaluation. The N15 labeled β-amyloid protein was used as the internal standard. Extraction was performed using Waters MCX 96-wells solid phase extraction plate, and the eluent was collected to QuanRecovery MaxPeak 700 μl plate. At the positive ion mode, the multi-reaction ion monitoring mode based on electric spray ionization is chosen for the determination of CSF Aβ 1-42, Aβ 1-40, and Aβ 1-38. Referring to the CLSI C62-A and EP-15A3 guidelines, the method is evaluated and verified, including quantitation of limit (LOQ), linearity, recovery, precision, and accuracy. In addition, a total of 57 clinical residual CSF samples were collected and the concentrations of Aβ 1-42 and Aβ 1-40 were determined based on manual INNOTEST ELISA assay and Lumipulse G and Roche Elecsys fully automated biochemical analyzers. The comparison analysis and deviation evaluation were conducted by passing-bablok and Bland Altman methods.Results:The analysis time of this method is 8 min, and the LOQ of Aβ 1-42, Aβ1-40 and Aβ1-38 is 0.1 ng/ml, 0.5 ng/ml, and 0.1 ng/ml, respectively, and the linear range can meet the needs of clinical detection. Respectively, the recovery is 86.2%-93.8%, 100.9%-103.9% and 103.3%-107.1%; the total imprecision is 4.7%-7.4%, 3.5%-4.6% and 5.2%-10.9%. The measured values of Aβ 1-42 certified reference materials are all within the allowable uncertainty requirements. Moreover, the carryover rate of three analytes was all≤0.11%. In addition, the correlations of Aβ 1-42 and Aβ1-40 in CSF between this LC-MS/MS method and the INNOTEST ELISA method, Lumipulse G and Roche Elecsys fully automated biochemical analyzers were all deemed good, with correlation coefficient (r) ranging from 0.920 to 0.970. However, the measured values between the four methods were remarkably different.Conclusion:We established and validated a robust method based on LC-MS/MS technology for simultaneous determination of Aβ 1-42, Aβ 1-40, and Aβ 1-38 in CSF. The method is accurate, simple, and suitable for clinical measurements. However, despite good correlations, there were substantial differences in the measurement results of Aβ 1-42 and Aβ 1-40 among different analytical platforms, indicating the need for further promotion of harmonization and standardization processes for AD classic biomarkers.
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Objective: To establish a method for rapid determination of bongkrekic acid (BA) in plasma by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Methods: In November 2020, plasma samples were extracted by methanol and acetonitrile (1∶1) and purified directly. The samples were separated by C18 column. Gradient elution was carried out with 5 mmol/L ammonium acetate water acetonitrile solution as mobile phase. Under the optimized instrument conditions, the electrospray ionization multiple reaction monitoring (MRM) mode was used, and the external standard method was used for quantitative analysis. Results: The linear relationship of BA in plasma was good in the concentration range of 2-100 μg/L, the correlation coefficient was 0.9998, the average recovery was 83.7%-112.0%, the relative standard deviation within and between batches was less than 10%, the detection limit of the method was 0.7 μg/L and the lower limit of quantification was 2.0 μg/L. Conclusion: The method is simple, rapid, accurate and sensitive, and can meet the requirements for the determination of BA in blood samples of poisoning patients.
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Humans , Bongkrekic Acid , Chromatography, High Pressure Liquid , Solid Phase Extraction , Tandem Mass SpectrometryABSTRACT
Objective:Analyze the correlation between serum immunoglobulin G (IgG) N-glycan and Lauren classification of gastric cancer.Methods:A retrospective study was performed on 17 patients with diffuse type gastric cancer and 21 patients with intestinal type who received treatment in Zhongshan Hospital from 2017 to 2018, and the general medical history data and disease characteristics were summarized. The serum IgG glycome profiles were analyzed by ultraperformance liquid chromatography, and the difference between intestinal type and diffuse type gastric cance was compared.Logistic regression was used to evaluate the correlation between serum IgG N-glycan and Lauren classification.Results:IgG N-glycome analysis included 27 directly detected glycans and 4 derived traits. H=Hexose, N=N-acetylglucosamine, F=Fucose, S=Sialic acid.There was no significant difference in IgG N-glycan among different chemotherapy protocol. Compared with intestinal type, H3N3F1 ( t=3.785, P=0.001), H3N4( t=3.919, P=0.002), H3N4F1( t=2.770, P=0.005), H3N5F1( t=2.888, P=0.010) were decreased in diffuse type; H4N4F1(6)( t=?3.488, P<0.001), H5N4F1( t=?3.401, P=0.003), H5N5F1( t=?2.303, P=0.023), H5N4F1S1 ( t=?3.068, P=0.008) were increased.H3N3F1( OR:1.20, P=0.008), H3N4( OR:1.32, P=0.005), H3N4F1 ( OR:1.13, P=0.017), H3N5F1 ( OR:1.78, P=0.015), H4N4F1(6)( OR:0.43, P=0.008), H5N4F1(6)( OR:0.74, P=0.008), H5N5F1 ( OR:0.32, P=0.036), H5N4F1S1( OR:0.48, P=0.009) were significantly correlated with Lauren classification. Sialylated ( t=?2.717, P=0.012) and galactosylated ( t=?3.400, P=0.001) IgG N-glycan were reduced in patients with intestinal type gastric cancer.Galactosylated ( OR:0.87, P=0.007) and sialylated ( OR:0.62, P=0.015) IgG N-glycan were significantly correlated with Lauren classification. Conclusion:Some IgG N-glycan are significantly correlated with Lauren classification, which can be used as potential biomarkers.
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Objective:To screen the potential biomarkers for the diagnosis and differential diagnosis of immune-mediated demyelinating diseases by tandem mass tags (TMT) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) technology.Methods:Twenty patients with demyelinating diseases (demyelinating group) and 10 patients with noninflammatory neurological diseases (NND group) from Beijing Tiantan Hospital affiliated to Capital Medical University from January 2020 to January 2021 were enrolled in this study. The demyelinating group included 10 patients with Guillain-Barre syndrome (GBS subgroup) and 10 patients with multiple sclerosis (MS subgroup). TMT proteomics was used to screen out the different protein expression patterns between the demyelinating group and the NND group and between the GBS subgroup and the MS subgroup (difference>2 or<0.5 and with statistical significance), and String database was used to perform gene ontology (GO) analysis and Kyoto encyclopedia of gene and genomes (KEGG) analysis on the pathways involved in the differently expressed proteins between the groups. In addition, 80 demyelinating patients (demyelinating diseases validation group) and 40 healthy subjects (healthy control group) were selected for retrospective analysis of general lipid indexes. The demyelinating diseases validation group included 40 GBS patients (GBS validation group) and 40 MS patients (MS validation group). Receiver operating characteristic (ROC) curve was obtained to evaluate the value of general lipid indexes for the diagnosis of demyelinating diseases and the differential diagnosis between GBS and MS groups.Results:A total of 362 proteins were detected by TMT proteomics. There were 101 differentially expressed proteins between the demyelinating group and the NND group, and 45 differentially expressed proteins between the GBS group and the MS group. Compared with the NND group, GO enrichment analysis showed that the top five enrichment pathways in the demyelinating group were macrophage colony stimulating factor and receptor complex, negative regulation of cholesterol input, negative regulation of very low density lipoprotein particle clearance, triglyceride-rich lipoprotein particle remodeling, and cholesterol reverse transport. Compared with MS group, the top five enriched pathways in GBS group were high-density lipoprotein particle receptor binding, negative regulation of very low density lipoprotein particle remodeling, negative regulation of cholesterol input, negative regulation of very low density lipoprotein particle clearance, and medium density lipoprotein particle. KEGG enrichment analysis results showed that differentially expressed proteins in the demyelinating group and the NND group were enriched in 8 pathways, including phosphatidylinositide 3-kinases-protein kinase B signaling pathway, complement and coagulation cascade reaction, extracellular matrix and its receptor interaction, Staphylococcus aureus infection, cholesterol metabolism, RAS signaling pathway, phagosome, and mitogen-activated protein kinase signaling pathway. Differentially expressed proteins in GBS group and MS group were enriched in 9 pathways: cholesterol metabolism, complement and coagulation cascade, platelet activation, peroxisome proliferators-activated receptors signaling pathway, vitamin digestion and absorption, novel coronavirus infection, fat digestion and absorption, axon guidance, and neutrophil extracellular trap formation pathway. The levels of triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and apolipoprotein B (apoB) were significantly higher, while high density lipoprotein cholesterol (HDL-C) and apolipoprotein A1 (apoA1) levels were significantly lower in the demyelinating disease validation group than in the healthy control group (all P<0.05 or 0.01). Area under the curve (AUC) of TG, TC, HDL-C, LDL-C, apoA1 and apoB alone or in combination for the diagnosis of immune-mediated demyelinating diseases was 0.746, 0.643, 0.798, 0.703, 0.806, 0.708 and 0.868, respectively. The AUC of HDL-C, apoA1, LDL-C and apoB for differential diagnosis between GBS and MS was 0.692, 0.653, 0.632, 0.695 and 0.718, respectively. Conclusions:There are differences in cerebrospinal fluid proteomics between patients with immune-mediated demyelinating disease and patients with NND, GBS and MS, and the differentially expressed protein patterns mainly exist in the pathways related to lipid metabolism. Lipid related indicators may be used as biomarkers for the diagnosis and differential diagnosis of immune-mediated demyelinating disease.
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Objective:To use the high performance liquid chromatography method to determine the content of formononetin in Jinji Pills and by using atomic absorption spectrophotometry,method to determine the harmful elements of heavy metal in Jinji Pills in orer to provide the scientific foundation for improving its quality standards and safety evaluation. Methods:Use Waters XBridge? C18 column (4.6 mm × 250 mm, 5 μm), set mobile phase at acetonitrile-1% phosphoric acid solution (27:73), flow rate 1.0 ml/min, column temperature 30 ℃, detection wavelength 249 nm, column temperature 30 ℃; Lead (Pb) and cadmium (Cd) was detected by graphite furnace method; arsenic (As) was detected by cold steam series graphite furnace method; copper (Cu) was detected by flame method; mercury (Hg) was detected by cold steam method.Results:The formononetin had a good linear relationship between 0.02-2.01 μg, the recovery rate was 98.5%, RSD was 1.53%. Lead (Pb) recovery rate was 103.6%, cadmium (Cd) recovery rate was 95.7%, arsenic (As) recovery rate was 92.4%, mercury (Hg) recovery rate was 104.9%, copper (Cu) recovery rate was 112.5%. Conclusion:This method is of accuracy, specificity, high sensitivity and good reproducibility, which could provide strong evidence for quality improvement and safety use of Jinji pill.
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Objective@#The aim of this study is to evaluate the commutability of 16 processed materials for 17-hydroxyprogesterone by using 2 commutability assessment approaches.@*Methods@#52 serum specimens were collected in Clinical Laboratory Department of Beijing Hospital from February 2018 to June 2019. According to the report of the Clinical and Laboratory Standards Institute (EP14-A3) document and the recommendations of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) working group on commutabilityassessment, serum 17-hydroxyprogesterone isotope diluent chromatogram tandem mass spectrometry (ID-LC/MS/MS) was used for comparison. Three clinical routine analysis systems (1 radioimmunoassay, 2 LC/MS analysis methods) were used to determine the concentration of 17-hydroxyprogesterone in 52 human serum samples and 16 processed materialsfor commutabilityassessment.@*Results@#Combined with the results of the two commutability assessment, all accuracy verification materials and national steroid hormone standards showed good commutability in the LC/MS analysis system, and 6/9 EQA materials showed commutability in the three routine analysis systems.All materials showed good commutability in the LC/MS analysis system of bias difference method.@*Conclusions@#The two kinds of commutability assessment results are different. Bias difference method has more clinical value, but it has certain application limitations. The use of fresh frozen human serum as a quality assessment materialfor serum 17-hydroxyprogesterone is meets the commutability requirement.
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Objective@#To understand vitamin A level of middle and primary school students in Qiongzhong Area in Hainan Province implementing the "Nutritional Compulsory Education Student Nutrition Improvement Plan" (hereinafter referred to as "Student Nutrition Plan"), and to provide suggestions for the followup implementation of student nutrition improvement work.@*Methods@#The multi-stage cluster sampling method was used to select three junior high schools and elementary schools in Qiongzhong County, Hainan Province, and students from 1-2 classes from each grade were randomly selected as survey objects. In March 2014, November 2015, December 2016 and December 2017, fasting venous blood was collected from students and serum vitamin A (Retinol) levels were detected by high-performance liquid chromatography.@*Results@#From 2014 to 2017, vitamin A levels were (358.77±88.44) (333.54±81.91) (345.84±86.08) (370.70±87.94)μg/L respectively, the subclinical deficiency rate of vitamin A were 22.3%, 31.6%, 27.9%, 18.0%, the vitamin A level of elementary school students were (332.92±71.80) (315.34±73.41) (327.44±77.02) (356.84±80.88)μg/L, the vitamin A level of junior high school students were (412.20±95.56) (383.20±83.53) (396.63±89.48) (411.60±95.14)μg/L, the difference were statistically significant by year (F=26.43, 4.01, P<0.05); vitamin A level and vitamin A subclinical rate of primary school students showed differences by year in both gender. The deficiency rate was statistically significant regardless of the annual difference between men and women(P<0.05); there was no statistically significant difference in the annual rate of vitamin A deficiency and sub-clinical vitamin A deficiency among junior high school students of different grades and genders (χ2=0.85, 2.08, 1.40, 2.36, P>0.05).@*Conclusion@#The implementation of "Student Nutrition Plan" in Qiongzhong area of Hainan Province shows pasitive effect on the vitamin A nutritional status of students. It’s suggested that prevention should be further strengthened, and nutrition knowledge publicity should be promoted.
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Objective To establish an analysis method for simultaneous determination of 13 sedative substances and their metabolites in blood by liquid-liquid extraction and liquid chromatography-tandem mass spectrometry （LC-MS/MS） technology and to apply the method to actual cases. Methods The samples were extracted with ethyl acetate after an internal standard was added. The extract was condensed until it was nearly dry and then its residues were dissolved with methanol, filtered through 0.22 μm filter and finally determined. The 13 sedative substances and their metabolites were separated through the C18 chromatographic column, then gradient elution was performed on them with methanol and 20 mmol/L ammonium formate （containing 0.1% formic acid） solution. After that, they were determined in the electrospray positive ion mode and quantified by internal standard method. Results The 13 sedative substances and their metabolites in blood showed good linearity in the range of 5-200 μg/L with correlation coefficients ranging from 0.990 3 to 0.999 8. The detection limits were 0.1-1.0 μg/L. Recovery rates of sedative substances were in the range of 71.2%-93.4% when solutions with concentrations of 10, 50 and 200 μg/L were added. The deviations of intra-day and inter-day relative standard deviations （RSD） were not more than 8.6%. Accuracies （bias） were within ±9.8%. Conclusion This method is rapid, simple, effective and sensitive, and can be applied to analysis of 13 sedative substances and their metabolites in blood in forensic toxicology.
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Chromatography, High Pressure Liquid , Chromatography, Liquid , Forensic Toxicology , Hypnotics and Sedatives , Tandem Mass SpectrometryABSTRACT
Objective@#To develop a method using ultra-high performance liquid chromatography-triple quadrupole mass spectrometry to determine the urinary metabolites of benzene, toluene and xylene. The selected metabolites are S-phenylmercapturic acid (S-PMA) , trans, trans-muconic acid (t, t-MA) , 8-hydroxy-2 deoxyguanosine (8-OHdG) , hippuric acid (HA) , 2-methylhippuric acid (2-MHA) , 3-methylhippuric acid (3-MHA) and 4-methylhippuric acid (4-MHA) .@*Methods@#The urine sample was pretreated using methanol to precipitate the proteins. HSS T3 chromatographic column was used to separate the metabolites. The mass spectrometric acquisition was carried out using multiple reaction monitoring (MRM) after ionization with ESI source. External standard method was used for quantification.@*Results@#All the standard curves showed good linear relation, and r of the seven metabolites was all above 0.999. The detection limits and quantitative limits of the seven metabolites were 0.01-500 ng/ml and 0.02-1 000 ng/ml (based on the actual dilution ratio) , respectively. The average spiked recoveries of four loadings ranged from 85.8% to 109.9%. The intra-day and inter-day precisions were 0.2%-4.5% and 0.6%-9.5%, respectively. The samples can be kept for at least 14 days at both 4 ℃ and -20 ℃.@*Conclusion@#This method is simple, rapid and highly sensitive with low cost, and its accuracy, precision and stability can meet the daily test requirements. It can be applied for the determination of urinary S-PMA, t, t-MA, 8-OHdG, HA, 2-MHA, 3-MHA and 4-MHA for the occupational population exposed to benzene, toluene and xylene.
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Objective@#To establish a method for determination of arsenic species in blood with high performance liquid chromatography-atomic fluorescence spectrometry (HPLC-AFS) .@*Methods@#The effect of mobile phase about chromatography separation and sample pretreatment conditions and atomic fluorescence spectrometry detection parameters has been optimized to reliably measure the following four kinds of species arsenic compound including arsenic[As (III) ]、dimethylarsinic acid (DMA) 、monomethylarsonic acid (MMA) and arsenate[As (V) ] in acute intoxication human blood. The method of technical standard about within-run, between-run and recoveries of standard were optimized.@*Results@#The method showed As (III) linear relationship was 2.63-100.00 μg/L, The detection limit was 2.63 μg/L. The relative coefficient (r) was 0.9999; DMA linear relationship was 3.21-100.00 μg/L, The detection limit was 3.21 μg/L. The r was 0.9992; MMA linear relationship was 3.41-100.00 μg/L, The detection limit was 3.41 μg/L. The r was 0.9998; As (V) linear relationship was 3.90-100.00 μg/L, The detection limit was 3.90 μg/L. The r was 0.9996. The average recovery of four species arsenic in tested samples ranged from 91.3%-99.8% with the relative standard deviation (RSD) from 2.39% to 4.05%. The within-run and between-run relative standard deviations (RSD) of repetitive measurement at 10.00, 40.00, 80.00 μg/L concentration levels were 1.99%-4.59% and 2.72%-4.53%.@*Conclusion@#This method is low detection limit, good accurate and high sensitivity, proposed method had been applied to the analysis of arsenic species in blood samples those who acute intoxication or poisoning diagnosis.
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Objective@#To establish a reference measurement procedure for the determination of human serum homocysteine by isotope dilution high performance liquid chromatography-tandem mass spectrometry (ID-LC/MS/MS), and to apply it to establish sample target values for external quality assessment (EQA) in clinical laboratories.@*Methods@#The reference method of Hcyquantification in our laboratory was establishedaccording to the method recommended by the Joint Committee for Traceability in Laboratory Medicine (JCTLM). The precision, trueness, specificity, residue and matrix effect of the method were evaluated. The reference method was applied to establish Hcy target values for samples of the second EQA in Shanghai of 2018.@*Results@#The method detects 12.5μmol/L and 37.4μmol/L samples in three batches in three days, and the CV between batches is 1.03% and 2.10%, respectively. The measured values of Standard reference material (SRM) 1955 of National Institute of Standards and Technology (NIST) were within the specified uncertainty range. No matrix effect and carryover were observed. The second EQA data in 2018 showed that the average value of domestic reagent group was lower than that of reference method, and that of imported reagent group was higher than that of reference method.@*Conclusion@#Thereference measurement procedure of ID-LC/MS/MS was successfully established to determine the human serum homocysteine. It is expected to play a role in tracing the quantities of Hcy in clinical laboratories.
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Objective To establish a reference measurement procedure for the determination of human serum homocysteine by isotope dilution high performance liquid chromatography-tandem mass spectrometry (ID-LC/MS/MS), and to apply it to establish sample target values for external quality assessment (EQA) in clinical laboratories. Methods The reference method of Hcyquantification in our laboratory was establishedaccording to the method recommended by the Joint Committee for Traceability in Laboratory Medicine (JCTLM). The precision, trueness, specificity, residue and matrix effect of the method were evaluated. The reference method was applied to establish Hcy target values for samples of the second EQA in Shanghai of 2018. Results The method detects 12.5μmol/L and 37.4μmol/L samples in three batches in three days, and the CV between batches is 1.03％and 2.10％, respectively. The measured values of Standard reference material (SRM) 1955 of National Institute of Standards and Technology (NIST) were within the specified uncertainty range. No matrix effect and carryover were observed. The second EQA data in 2018 showed that the average value of domestic reagent group was lower than that of reference method, and that of imported reagent group was higher than that of reference method. Conclusion Thereference measurement procedure of ID-LC/MS/MS was successfully established to determine the human serum homocysteine. It is expected to play a role in tracing the quantities of Hcy in clinical laboratories.
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Objective To study the newborn screening program,morbidity,laboratory findings,gene mutations,treatment and follow-up of neonatal propionic academia (PA) in Xuzhou City.Method From September 2015 to September 2018,the blood sample of neonates from newborn screening program in Xuzhou were measured using liquid chromatography tandem mass spectrometry (LC-MS/MS) method to examine the blood acylcarnitine level.The diagnosis was confirmed by urine gas chromatography mass spectrometry (GC-MS) and gene analysis.The clinical manifestation,laboratory findings,gene analysis,treatment and prognosis were retrospectively analyzed.Result A total of 297 610 live birth infants blood samples were screened using MS/MS,and 8 cases were diagnosed with PA,with a prevalence of 1∶37 201.Among the 8 patients,7 had no clinical symptoms before the diagnosis and one already had symptoms including recurrent vomiting,drowsiness,tachypnea and hypotonia.Gene analysis revealed that 6 cases carried propionyl-CoA carboxylase α (PCCA) gene mutations and 2 cases carried propionyl-CoA carboxylase β (PCCB) gene mutations.A total of 10 types of PCCA gene mutations were detected,including 5 missense mutations,4 splicing mutations and 1 synonymous mutation,among which 7 were de-novo mutations.A total of 4 types of PCCB gene mutations were detected,including 2 missense mutations,1 frameshift duplication and 1 splicing mutation,among which 3 were de-novo mutations.1 patient died after refusing treatments.The other 7 cases showed significant decline of the blood propionyl-carnitine level,the ratio of propionyl-carnitine to acetylcarnitine,3-OH-propionate and methylcitrate level in urine after treatment.4 cases had normal growth and development,and 3 cases showed various psychomotor retardation on follow-up.Conclusion Newborn screening using LC-MS/MS method is important for early diagnosis of PA.The incidence of PA is relatively high in Xuzhou City.The major clinical manifestations of PA were neurological symptoms.The main cause is PCCA gene defects and missense mutation is most common.
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Objective To investigate the digestion kinetics of Apolipoprotein A-I and B by ID-LC-MS method for accurate quantification of proteins .Methods Methodological research .The target peptides of ApoA-I and B were determined .The ApoA-I and B from 5 human serum samples on market with levels from 0.90-2.54 g/L and 0.54-1.39 g/L separately , were measured in terms of target peptides by isotope dilution liquid chromatography mass spectrometry method .The releasing amount and rate of peptides were analyzed and plotted according to different time points .The correlation coefficient R2 was calculated among peptide releasing amount between samples .Results Most peptides reached their peaks within 4 hours.The peptides VQ , DY and VS from Apo A-I, TR and FP from Apo B were released relatively slowly .After getting to their peak stage , the ratio between TEV and SIL-TEV, AK and SIL-AK, VQ and SIL-VQ presented stable state.As for Apo A-I the correlations among peptides are high , from 0.904 to 0.999.Some peptides from Apo B show lower correlations , such as TG-SV with R20.543 (3 h).Conclusions Peptides from Apo A-I and Apo B present different releasing properties after trypsin digestion .Proper selection of representative peptides and enzymatic conditions can benefit accurate quantification of target proteins .
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Objective To investigate the characteristics of neonatal methylmalonic aciduria (MMA)regarding clinical manifestations,laboratory findings,gene mutations,treatments and prognosis.Methods Acylcamitine levels in blood samples of 207 308 neonates born from January 2016 to December 2017 in Xuzhou were detected by liquid chromatography tandem mass spectrometry and the abnormal results were further confirmed by detecting organic acids in urine samples with gas chromatography-mass spectrometry and gene sequencing analysis.Patients with isolated MMA were treated with dietary control and levocarnitine,while those complicated by homocysteinemia were treated with vitamin B12,levocarnitine,glycine betaine and calcium folinate.Clinical manifestations,laboratory findings,imaging features,genotypes,treatments and prognosis of patients with MMA were retrospectively analyzed.Paired sample t-test was applied for statistical analysis.Results MMA was eventually diagnosed in 12 patients,among which three were isolated MMA and nine were complicated by homocysteinemia.The three isolated MMA cases failed to response to vitamin B12 treatment without any symptoms on diagnosis.However,vitamin B12 was effective for the other nine patients,among which four had no clinical symptoms on diagnosis and five had manifestations such as slow response,recurrent vomiting,poor feeding,dyspnea,anemia and jaundice.Abnormal results of cranial MRI included bilateral basal ganglia damage,enlarged extracranial space,ventriculomegaly and changes in white matter.All patients underwent genetic analysis and three were found with MUT gene mutations and nine with MMACHC gene mutations.MUT gene mutations were classified into five types,including c.I106G＞A,c.1880A＞G,c.441T＞A,c.581C＞T and c.1741C＞T.Eight types of MMACHC gene mutations were identified,including c.609G＞A,c.658_660delAAG,c.482G＞A,c.1A＞G,c.567dupT,c.80A＞G,c.276+1G＞A and c.228_23 l delTGAC.Two mutations,c.276+lG＞A and c.228 23 ldelTGAC,were novel mutations.The most common mutation in MMACHC gene was c.609G＞A,followed by c.658_660delAAG and c.482G＞A.One of the isolated MMA patients died after refusing treatments and the other two showed significant decrease in serum propionylcarnitine,propionylcarnitine to acetylcarnitine ratio,serum homocysteine and methylmalonic acid and methylcitric acid in urine after treatment.Moreover,of the two patients who were alive at follow-up,one experienced normal growth and development and the other suffered from growth retardation.The ratio of propionylcamitine to acetylcarnitine and the levels of serum propionylcarnitine,serum homocysteine and methylmalonic acid and methylcitric acid in urine were significantly decreased in the nine patients with MMA complicated by homocystinuria after one month of treatment [0.88±0.35 vs 0.13±0.05,(7.12±1.90) μ mol/L vs (3.18±1.08) μ mol/L,(136.48±38.14) μ mol/L vs (34.41±17.33) μmol/L,103.51±69.62vs 5.35±2.15 and 7.95±6.88 vs 1.02±0.48,t=-6.166,-6.687,-12.941,-4.208 and-3.015,respectively,all P＜0.05].Two deaths,three asymptomatic and four psychomotor retardation patients were reported during follow-up.Conclusions Newborn screening with liquid chromatography tandem mass spectrometry is important for early diagnosis of MMA.MMACHC gene defects are the main causes of MMA in Xuzhou area and the predominant one is c.609G＞A mutation.Prognosis of MMA might be related to disease type,age of onset and patient's reactivity to vitamin B12.
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Objective To analyze the vitamin D status among apparently healthy younger and elder adults in Beijing based on liquid chromatography tandem mass spectrometry.Methods This is an observational study.Participants included 287 apparently healthy young adults(143 males and 144 females) with an average of (32.2 ± 6.9) years old (19-44 years).At the same time 198 middle-and elder-aged adults were recruited [90 males,108 females,(55.6 ± 7.6) years],and fasting blood samples were collected and serum were isolated.They measured 25-hydroxyvitamin D (25OHD:25OHD2 and 25OHD3)using liquid chromatography tandem mass spectrometry method.Vitamin D with deficiency,insufficiency,sufficiency and intoxication was categorized as 25OHD ＜ 20 ng/ml,20-30 ng/ml,30-150 ng/ml,and ≥ 150 ng/ml,respectively.ALT,Ca,P,Cr,Glu,TG,TC and iPTH wereanalyzed using automatic analyzers.Statistical analysis was performed using SPSS17.0.Results The median 25OHD level in the total studied younger adults was 16.0 [2.5％-97.5％:(6.1-29.0) ng/ml] which didn't show significant difference with that of middle-and elder-aged adults.Younger males had significant higher level of 25OHD than females [17.9 (8.3-32.3) ng/ml vs.14.4 (5.4-26.4) ng/ml,Z =-4.238,P ＜ 0.01].Of the total younger subjects,the rate of vitamin D with deficiency (＜ 20 ng/ml),insufficiency (20-30 ng/ml)and sufficiency (≥30 ng/ml) was 72.8％,25.1％,2.1％,respectively,while that of middle-and elderaged adults was 76.3％,21.2％,2.5％ respectively,and that of younger males was 65.0％,30.8％,4.2％,respectively while that of younger females was 80.6％,19.4％,0％,respectively.Younger females had significantly higher rate of 25OHD deficiency (x2 =31.766,P ＜ 0.01).With adjusting sex,age and BMI,serum iPTH (r =-0.264,P ＜ 0.01) was significantly negatively correlated with 25OHD while Cr (r =0.221,P ＜ 0.01) showed significantly positively correlation with 25OHD.Conclusion Vitamin D deficiency is prevalent in both younger and elder adults in Beijing,especially in younger females.
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Objective To explore the value of the combination of homocysteine analysis, liquid chromatography tandem mass spectrometry(LC-MS/MS)and gas chromatography mass spectrometry(GC/MS)in the prenatal diagnosis of combined methylmalonic acidemia and homocystinuria(cblC defect)in amniotic fluid.Methods This is a retrospective study of 187 cases of pregnancies that came to our hospital for prenatal diagnosis between 2014/01-2017/03,among which 78 cases′probands were cblC defect patients and 109 cases′probands were not organic academia patients(control group).Amniotic fluid samples from pregnant women were obtained at 16 -24 weeks of gestation.Propionylcarnitine(C3)and acetylcarnitine (C2)were measured by LC-MS/MS, methylmalonic acid and methylcitric acid were analyzed by GC /MS, and homocysteine was determined by fluorescence polarization immunoassay.Some pregnancies received MMACHC gene sequencing with cultured cells from amniotic fluid.Data were analyzed using Mann-Whitney U and Kruskal-Wallis H tests.Results Among those 78 pregnant women whose probands were diagnosed to be cblC defect,24 cases were diagnosed to be cblC defect(positive group)and 54 pregnant women were diagnosed to be negative(negative group).In positive group, levels of homocysteine, C3, C3/C2, methylmalonic acid and methylcitric acid were all significantly higher than their normal reference ranges, negative group and control group(P values are 0.00).Cases that were diagnosed to be cblC defect by MMACHC gene sequencing were all turned out to be positive in the tests of the above metabolites in amniotic fluid.Cases with negative results of the metabolites were all excluded to be cblC defect by gene sequencing. Besides,2 cases of pregnancies were diagnosed to be positive by homocysteine and mass spectrometric analysis while only one mutation were detected by gene sequencing.Conclusions The combination of homocysteine, LC-MS/MS and GC/MS analysis in amniotic fluid turns out to be reliable for prenatal diagnosis of cblC defect,which may further cover the defect of prenatal diagnosis of those pregnancies whose probands′gene mutation is unknown.
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Objective This study is aimed to investigate the prognostic significance of ring sideroblast ( RS) in MDS( Myelodysplastic Sydrome ) and evaluate the correlation of RS and other prognostic index.Methods A total of 198 patients with MDS between March 2009 and December 2015 in Chinese PLA′s Gerneral hospital were chosen for this study .Based on the ratio of RS in nucleated red blood cell , patients were first separated into myelodysplastic syndrome without ring sideroblast (MDS RS-) group, RS≥15%, and myelodysplastic syndrome with ring sideroblast ( MDS RS +) group, RS <15%. Then, according to the proportion of blasts in bone marrow nucleated cells above 5%or below, patients were further divided into myelodysplastic syndrome with low blasts without ring sideroblast ( MDS-LB RS-) group, myelodysplastic syndrome with low blasts and ring sideroblast ( MDS-LB RS+) group, refractory anemia with excess blast without ring sideroblast ( RAEB RS-) group and refractory anemia with excess blast and ring sideroblast ( RAEB RS+) groupe.All patients had completed the morphological , genetics , molecular biology examination at dignosis, and followed up by phone.The results of the overall survival (OS) analysis have been presented in a Kaplan-Meier curve and cox regression model .Last, according to the percentage of RS in nucleated red blood cell , patients were separated into RS <5%groupe, 5%-15%group, 15%-40%group, RS≥40%group, and analyse their survival prognosis by statistical methods .Results Comparing to MDS RS-group, the morbidity age, WBC and PLT count were significantly higher [61 ±1.91 vs 52 ±1.37, t=-3.555, P<0.01, 3.82(0.47-323)vs 2.6(0.6-59.7), z=-4.014, P<0.01;139.5(7-608) vs 60(3-724), z =-3.988, P<0.01], bone marrow eythroid hyperplasia and gigantocyte were more obvious in MDS RS+group[χ2 =11.032, P<0.01, χ2 =5.165, P<0.05]; the percentage of GATA1 gene and abnormal rate of poor prognosis gene ( MLL, NRAS, WT1 ) , either mutation or high gene expression , were higher in MDS-LB RS+group than that in MDS-LB RS-( P<0.05 ); Contrasting with RAEB RS-group, the karyotype is worse in RAEB RS +group[χ2 =4.966, P<0.05];Comparing to 15%-40%group, the OS were poorer in RS≥40%;MDS RS+patients were more prone to adverse prognosis than MDS RS-patients.Conclusion Compared to MDS RS-group, MDS RS +patients had worse prognosis;RS maybe correlate to morbidity age , eythroid dysplasia and gene abnormality in affecting the survival prognosis of MDS.