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Machine learning approaches are increasingly being applied to neuroimaging data from patients with psychiatric disorders to extract brain-based features for diagnosis and prognosis. The goal of this review is to discuss recent practices for evaluating machine learning applications to obsessive-compulsive and related disorders and to advance a novel strategy of building machine learning models based on a set of core brain regions for better performance, interpretability, and generalizability. Specifically, we argue that a core set of co-altered brain regions (namely 'core regions') comprising areas central to the underlying psychopathology enables the efficient construction of a predictive model to identify distinct symptom dimensions/clusters in individual patients. Hypothesis-driven and data-driven approaches are further introduced showing how core regions are identified from the entire brain. We demonstrate a broadly applicable roadmap for leveraging this core set-based strategy to accelerate the pursuit of neuroimaging-based markers for diagnosis and prognosis in a variety of psychiatric disorders.
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Humans , Obsessive-Compulsive Disorder/epidemiology , Brain/pathology , Neuroimaging/methods , Machine Learning , Comorbidity , Magnetic Resonance Imaging/methodsABSTRACT
Objective:To construct a prokaryotic expression vector for human retinol binding protein 4 (hRBP4) that allows technicians to obtain hRBP4 purified protein with low cost, high efficiency, high concentration and high purity.Methods:The hRBP4 coding sequence provided by National Center for Biotechnology Information was optimized by E. coli codons, and a synthetic DNA fragment was cloned into the PET-28A (+) prokaryotic expression vector to construct a recombinant hRBP4 expression plasmid. The recombinant protein was transformed into E. coli BL21, and the induced expression conditions (temperature, rotate speed and isopropyl β-d-thiogalactoside concentration) were optimized. The recombinant protein was purified by His fusion tag. Results:The recombinant hRBP4 prokaryotic expression plasmid was successfully constructed, and the expression concentration and induction temperature of the recombinant protein were optimized. The results of sodium dodecyl sulfate polyacrylamide gel electrophoresis showed that a band with a relative molecular weight of 26 000 daltons was clearly visible in the purified product. The purified hRBP4 protein could be detected clinically, and there was a good linear relationship between the dilution ratio and the detection concentration.Conclusions:The recombinant hRBP4 protein has high purity, high concentration, and short production cycle. It has the potential to become a candidate for reference materials for laboratory quality evaluations.
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Objective:To investigate the molecular mechanism of proliferation-inhibiting effect of icaritin on hepatoma cells via regulating miRNA-329 (miR-329) and miRNA-1236 (miR-1236).Methods:Hepatoma cell line HepG2 was treated with icaritin at different concentrations (2.5, 5.0, 10.0, 20.0, 40.0 μmol/L), and the control group only added dimethyl sulfoxide (DMSO). The half inhibitory concentration ( IC50) of icaritin on HepG2 cells and cell proliferation rate were detected by CCK-8 after cultured for 36 h. HepG2 cells were treated with 400 μg/L alpha fetoprotein (AFP). After cultured for 0, 12, 24, 36, 48 and 60 h, the effect of AFP on the proliferation of HepG2 cells was detected by CCK-8 method. AFP-3'UTR reporter plasmid pmirGLO-AFP-3'UTR plasmid was constructed, pmirGLO blank vector plasmid, pmirGLO-AFP-3'UTR plasmid, miR-329 or miR-1236 mimics or inhibitors, control plasmid of mimics (NC), control plasmid of inhibitors (INC) were respectively co-transfected with HepG2 cells, and the effect of miR-329 and miR-1236 on the luciferase activity was detected by dual-luciferase reporter assay after cultured for 24 h. Western blot and real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) were used to detect the effects of icaritin on the expressions of AFP, miR-329 and miR-1236 in HepG2 cells. HepG2 cells were respectively transfected with mimics and inhibitors of miR-329 and miR-1236 to detect the effects of miR-329 and miR-1236 on the expression of AFP. Results:The cell proliferation rates of 2.5, 5.0, 10.0, 20.0, 40.0 μmol/L icaritin group and control group were (80.4±2.3)%, (73.2±1.6)%, (51.7±3.3)%, (38.2±4.6)%, (29.5±4.3)%, and (94.0±2.9)%, respectively, and the difference was statistically significant ( F = 75.65, P < 0.01); the differences in the proliferation rate of HepG2 cells between different concentrations of icaritin group and control group were statistically significant (all P < 0.01). The IC50 of icaritin on HepG2 cells was 10 μmol/L. The relative expressions of AFP mRNA in 2.5, 5.0, 10.0, 20.0, 40.0 μmol/L icaritin group and control group were 0.83±0.06, 0.69±0.02, 0.53±0.07, 0.45±0.01, 0.33±0.07, and 1.00±0.01, respectively, and the difference was statistically significant ( F = 42.67, P < 0.01); the differences in the relative expressions of AFP mRNA between different concentrations of icaritin group and control group were statistically significant (all P < 0.01). HepG2 cells were treated by 400 μg /L AFP for 0, 12, 24, 36, 48 and 60 h, and the cell proliferation rates were (102±5)%, (138±13)%, (186±24)%, (260±12)%, (311±15)%, and (348±25)%, respectively, and the difference was statistically significant ( F = 27.483, P < 0.01); the differences in the cell proliferation rate between different time of AFP treatment and 0 h were statistically significant (all P < 0.01). Compared with the control group, different concentrations of icaritin can promote the expression of miR-329 and miR-1236 (all P < 0.01). After co-transfection of miR-329 and miR-1236 mimics and AFP-3'UTR, the luciferase activity decreased by about 40%; after co-transfection of miR-329 and miR-1236 inhibitors and AFP-3'UTR, the luciferase activity increased about 1.5 times. Both miR-329 and miR-1236 can reduce the expression levels of AFP protein and mRNA (both P < 0.05). Conclusion:Icaritin can promote the binding of miR-219, miR-1236 and AFP-3'UTR by promoting the expression of miR-329 and miR-1236, inhibit the stability and translation activity of AFP mRNA, inhibit the expression of AFP, and thus inhibit the proliferation of hepatoma cells in vitro.
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Objective:To establish the allowable total error (TEa) of the national external quality assessment (EQA) program in line with the current quality level of serum folate measurement in China.Methods:The data of serum total folate test in the clinical laboratory of a hospital in Beijing in 2016 were collected, and the Stata SE 15 software was used for Monte Carlo simulation to obtain the false-negative rate under different bias and inaccuracy conditions. The Origin Pro 9.1 software was used to make the contour figure. The TEa of serum total folate test is derived based on the acceptable false-negative rate. National EQA data of serum total folate in 2020 were collected to calculate the pass rate of participating laboratories and the laboratory pass rate of quality control products at each level under the five TEa derived from the analysis performance on clinical outcomes, biological variation, and the evaluation criterion of national EQA.Results:Based on the influence of analytical performance on clinical outcomes, the TEa was 10%. Under this TEa, the pass rate of the first EQA program of serum total folate in 2020 was more than 80%, and the pass rate of the second time was 73.1%. Under the minimum (46.57%) and appropriate level of TEa (15.52%) derived from biological variation and national EQA evaluation criterion, the pass rate of serum total folate in the two EQA programs in 2020 exceeded 85%.Conclusion:The analytical performance of serum total folate in China cannot meet the requirements of TEa derived based on the effect of analytical performance on clinical outcomes. An appropriate level of TEa derived based on biological variation (15.52%) is suggested as the recommended criterion for the TEa of serum total folate test.
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Objective:To establish an accurate quantitative method for the determination of serum glycated albumin (GA) based on isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS).Methods:This study optimized the ID-LC/MS method recommended by the Japan Society of Clinical Chemistry (JSCC). Albumin (Alb) was purified by anion exchange chromatography. The standard solution of purified sample, lysine (Lys) and deoxyfructosyl lysine (DOF-Lys) and their mixed internal standard were weighed accurately by weight method. The Alb was hydrolyzed to amino acid, and Lys and DOF-Lys were detected to determine GA. The method was evaluated and compared with the routine method.Results:The purity of Alb was 100%. The R 2 ranges of Lys and DOF-Lys linear standard curves were 0.997 8-0.999 9 and 0.999 4-1.000 0. The results of three-day precision evaluation of low, medium and high concentrations of serum were 0.69%-1.97%, 1.13%-2.33% and 1.37%-2.54% in intra, inter and total Coefficient of variation ( CV). In the accuracy evaluation, the deviations between the results of three concentration standards and the certified value were -2.56%, -1.87% and-2.94%. The matrix effects of Lys and DOF-Lys were 89.92% and 109.98%, and the carryover rates were -1.13% and -3.27% respectively. The detection limit and quantitative limit of Lys were 0.075 nmol/g and 0.248 nmol/g, and the DOF-Lys were 0.007 nmol/g and 0.024 nmol/g. The relative expanded uncertainty was 1.60%-2.03%. The fitting regression curve R 2 with the routine method was 0.970 7. Conclusions:A method was established for the detection of serum GA. The method evaluation was accurate and reliable. It was expected to be a candidate reference method for the detection of serum GA.
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Objective:To evaluate the performance of aldosterone testing in China through the External Quality Assessment (EQA) and improve the testing quality of aldosterone.Methods:Two kinds of EQA program for aldosterone were carried out in China, one of which is Routine EQA and the other is Trueness verification scheme. Lyophilized sera with 5 concentration levels were used as quality control of Routine EQA. The results were grouped according to the instrument. Target values and the coefficient of variation ( CV) were calculated in each group. Trueness verification scheme was verified by using frozen human sera of 3 concentration levels determined by the reference method, and the bias of each instrument group from the target value was calculated. Results:272 laboratories submitted the testing results, and 91.6% of laboratories used chemiluminescence method. The maximum CV was obtained by radioimmunoassay and liquid chromatography mass spectrometry, and the robust CVs were 14.6%-33.4% and 43.5%-53.9%, respectively. For chemiluminescence methods, the robust group CV was less than 10%. The results of the Trueness verification scheme showed that liquid chromatography mass spectrometry method was the most accurate method, with biases of -7.9%, 8.9% and -0.7% for the three quality controls. Diasorin system had the more accurate results deviated from the target by 58.7%, 7.9% and -2.1%, respectively. The results of other chemiluminescence methods were negatively correlated with the sample concentration, and one of them with a bias of 479%. Conclusions:The accuracy and comparability of aldosterone among laboratories in China are not satisfactory. Reagent manufacturers and laboratories should pay more attention to EQA, with the aldosterone results traceable to SI unit, and improve the test quality of aldosterone.
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Chronic kidney disease caused by diabetes and hypertension has become a global public health problem. Urinary albumin is one of the key indicators for the diagnosis and grading of chronic kidney disease, and it has been widely used in practice. Accurate and comparable results of urinary albumin detection served as an important basis for clinical application. This paper discussed the status of urinary albumin detection and the progress of standardization, in order to help the laboratory correctly interpret the test results and promote the quality of diagnostic products.
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Objective Accurate measurement of aldosterone is critical in the diagnosis of primary aldosteronism. We compared the harmonization of three assays including isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) and two chemiluminescence immunoassays (CLIAs:system A and system B) for the aldosterone measurement. Methods A total of 45 plasma samples, 4 quality control materials, 5 lyophilized bovine serums, and 3 fresh frozen human serum pools were measured by three assays respectively. Based on CLSI EP15-A3 rule, the precision was assessed by coefficient of variance. Deming regression and Bland&Altman plots was performed for method comparison, and correlation coefficient was calculated for concordance (CCC). Results All three methods met the performance criteria based on desirable biological variation for precision (<7.35％). System A showed a relevantly good correlation and comparability with ID-LC/MS/MS (R2=0.985, CCC=0.967), while System B showed relevantly bad correlations and comparability with both System A (R2=0.538, CCC=0.605) and ID-LC/MS/MS (R2=0.547, CCC=0.528).. However, the average relevant bias of two CLIAs exceeded the bias requirement derived from biological variation (18.60％). Conclusion Significant differences were found in the measurement of plasma aldosterone using ID-LC-MS/MS and two CLIAs, which urges the establishment of traceability hierarchy and improvement of reagents' specificity for standardization of aldosterone measurement in clinical settings.
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Objective To perform a methodological evaluation study of 4 HPLC based systems and a capillary electrophoresis based system , with the International Federation of Clinical Chemistry and Laboratory Medicine ( IFCC) glycated hemoglobin reference method as a comparative method .Methods 40 hemolysis samples of variety concentrations were prepared .The samples were measured by IFCC reference method and 5 glycated hemoglobin testing systems , respectively and trueness verification was performed according to the Clinical &Laboratory Standards Institute (CLSI) guideline EP9-A3.Whole blood samples were used to test the systems'precision, linearity and analytical interferences .Results The average CV of IFCC reference method results of 40 hemolysis samples was 1.4％( range from 0.2％to 2.5％).No outlier was found in the results of the 5 testing system.The slopes ranged from 0.9902 to 1.0267, and intercepts from -0.1526 mmol/mol to +0.1512 mmol/mol, squared correlation coefficient from 0.9962-0.9971, biases at two medical decision level were less than 0.3％HbA1c.Within-laboratory precisions were less than 2％ (NGSP unit).Bias between all test results and predicted results were less than 5％.High concentration of glucose showed certain interference to glycated Hemoglobin tests but had little influence in clinical practice.Conclusions The results of the 5 testing system are comparable to the IFCC reference method , the results of precision and linearity evaluation meet the requirements of related guidelines .
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Objective To investigate the clinical,therapeutic and prognostic features of patients with lateral sinus stenosis and isolated intracranial hypertension,and further explore the possible mechanisms of their coexistence.Methods We retrospectively enrolled 16 patients with neurosurgery in our hospital from January 2009 to December 2016,who were clinically diagnosed as simple intracranial hypertension with bilateral or predominant lateral sinus stenosis and lateral stenting.These 16 patients were recorded surgical procedures and postoperative outcomes,and followed-up to understand the long-term prognosis of them.Results There were 14 females in the 16 patients,with an average age of (32.4 ± 10.1) years,a mean duration of (10.9 ± 7.3) months,and an average body mass index of (28.9 ± 3.6) kg/m2.In terms of clinical manifestions,majority of the patients presented with headache (n =15) and visual symptoms (n =14),and all with papilledema by fundus examination.The elevated opening cerebrospinal fluid (CSF) pressure was noticed:five cases between 25-33 cmH2O (1 cmH2O =0.098 kPa),11 cases more than 33 cmH2O.The mean pressure difference in the proximal and distal sinus of the anterior chamber was (36.3 ± 9.4) cmH2O in the range of 15-91 cmH2O.The pressure difference between the two ends of the stenosis disappeared immediately after the operation in 12 cases and the pressure difference less than 15 (2-12) cmH2O in four cases.Thirteen patients underwent lumbar puncture at one week after operation.The CSF pressure of them decreased significantly,of which eight were in the normal range.Six months after the operation,11 patients underwent DSA/MRV,none of which had serious surgical complications.With the average follow-up of (35.4 ± 9.8) months,the overall prognosis of these patients was good.Headaches in 14 of 15 patients were improved,out of which 12 were free of headache,two with only mild headache and a slight intracranial hypertension (19 and 23 cmH2O,respectively);visual complaints were reversed in nine out of 14 cases;10 patients underwent fundus examination,and nine of them were observed the improvement of papilledema.During the follow-up period,the symptoms of other patients were improved (headache relief and visual improvement) except one,the overall effective ratio being 15/16.Conclusions The interventional treatment of lateral sinus stenting is effective in patients with sinus stenosis associated with simple intracranial hypertension.The stenosis of the lateral sinus may be the main mechanism of increased intracranial pressure.
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Objective To compare the difference in risks of obstetric complications of singleton pregnancy between women with hyperandrogenic polycystic ovary syndrome (PCOS) and women with normoandrogenic PCOS. Methods Prospective cohort study. This study was a secondary analysis of data collected during a multicenter randomized controlled clinical trial. Women who got clinical singleton pregnancy were grouped according to whether they were diagnosed with hyperandrogenism at baseline. There were 118 women with hyperandrogenism and 366 women without hyperandrogenism. The incidences of obstetric complications and birth weight were compared between the two groups. Results Women with hyperandrogenic PCOS had a significantly higher risk of preterm delivery than women with normoandrogenic PCOS [12.7％ (15/118) versus 3.6％ (13/366); OR=3.94, 95％CI: 1.82-8.56]. After adjustment of age, duration of infertility, body mass index, and fresh or frozen embryo transfer group, hyperandrogenism was still associated with an increased risk of preterm delivery (OR=3.67, 95％CI: 1.67-8.07). Compared with women with normoandrogenic PCOS, women with hyperandrogenic PCOS had similar risks of pregnancy loss, gestational diabetes mellitus, pre-eclampsia, placenta previa, and postpartum hemorrhage (all P>0.05). Birth weight as well as the risks of being small for gestational age and large for gestational age were also comparable between the two groups (all P>0.05). Conclusion In women with PCOS and singleton pregnancy, those with preconceptional hyperandrogenism have a higher risk of preterm delivery than those without hyperandrogenism.
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Objective To understand the current status of the measurement quality of serum Cystatin C (CysC) in China.Methods The external quality assessment (EQA) data in 2017 were collected from the network platform of National Center for Clinical Laboratories.The EQA data were classified into 8 groups according to different types of diagnostic reagents,each of which was employed by at least 18 users.The robust mean value and robust coefficients of variation (CV) were calculated according to ISO 13528 document in each group.The robust mean value was set as the target value.The total error derived from biological variation was used as the fine (3.8％),moderate (7.6％) and weak (11.4％) criteria in evaluating the pass rates,respectively.The reagents which were employed by more than 50 users were classified into subgroups named as " reagent-analyzer" group according to the used analyzer.The median values and differentials between maximum and minimum value were calculated for each reagent-analyzer subgroup.Results A total number of 710 laboratories submitted their results of CysC measurement during 2017.The fine,moderate and weak pass rates according to the setting criteria were 25.9％ (184/710),55.5 ％ (394/710) and 75.2％ (534/710),respectively.The variations of CysC measurement results of among different reagent-analyzer groups ranged from 1.62％ to 12.27％.Conclusion The quality of CysC measurement of should be improved with nationwide attention.
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Objective To evaluate the consistency and comparability of two kinds of cholesterol reference methods listed in the Joint Committee for Traceability in Laboratory Medicine(JCTLM).Methods 52 fresh frozen sera with cholesterol concentrations among 3 -10 mmol/L were tested by isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS)and high performance liquid chromatography(HPLC).The precision and accuracy of the two methods were calculated,and then a series of analysis were conducted including plotting scatter plots and deviation graphs,testing outliers,selecting the best fitting regression models and calculating the regression equations and parameters,and so on.The results of the two methods were statistically analyzed to estimate the expected deviation at the level of medical decision of cholesterol and the 95% confidence range.Results For HPLC method,the CV of instrument measurement was 0.22%(0 -0.49%),the total CV of samples measurement was 0.36%(0.02% -0.83%),and the average bias of the reference materials was 0.37%(-1.31%-0.14%).For ID-LC/MS/MS method,the CV of instrument measurement was 0.50%(0 -1.51%),the total CV of samples measurement was 0.55%(0.03%-1.17%),and the average bias of the reference materials was 0.24%(-0.53%-0.14%).No outliers were found from the scatter plots and the statistical analysis and the linear regression were fitted to analyze the results of the two methods.The linear regression parameters of two methods for 52 fresh frozen human sera were as follows:the slope was 0.989 5,the standard error of slope was 0.003 4,the intercept was 0.063 4 mmol/L,the standard error of intercept was 0.019 9 mmol/L,the standard error of Y-estimate was 0.034 8 mmol/L,and the correlation coefficient was 0.999 7.Compared with the ID-LC/MS/MS method,the absolute deviation of fresh sera by HPLC method was 0.000 mmol/L (-0.083-0.076 mmol/L),with a relative deviation of 0.07%(-1.22-1.24%).T-test results showed no statistically significant difference between the two methods.The expected deviations at the cholesterol medicine decision level were within the range 95% confidence range,and the expected deviations were far less than the allowable error.Conclusions The HPLC method of cholesterol has good consistency and comparability with ID/MS method using the primary measurement principle.Because of more advantages of HPLC method such as less cost,more simple,requirement,and better precision,HPLC method is expected to play an important role in the process of standardization and traceability of serum cholesterol.
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Objective Preparation of aqueous reference materials for cholesterol and glycerol.Methods Study on reference materials.The certified reference materials GBW09203b and GBW09149 were weighed accurately and dissolved into 20% of methyl cyclodextrin aqueous solution to prepare six kinds of candidate reference materials of cholesterol and glycerol according to the concentration.The materials were tested for homogeneity and stability using routine methods.The reference methods of isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS) were used to determine the concentration of cholesterol and glycerol to evaluate the accuracy of the certified values.Meanwhile, the blank verification test was carried out.The expanded uncertainty was the combination of standard uncertainty of measurement, unhomogeneity and instability.Results It showed that the six candidate reference materials were homogeneous and stable for at least 1 year at-70 ℃ and-20 ℃.The certified values (reference value ± expanded uncertainty,mmol/L) were as follows,for cholesterol:0.65±0.01,1.31 ±0.01,2.57±0.02,5.21±0.06,7.71±0.08,10.24±0.06;for glycerol:0.29±0.01,0.58±0.01,1.22±0.02,2.24±0.02,3.46±0.04,4.52 ±0.04.The results of reference methods were consistent with the certified values.Blank validation tests showed that the concentration of the analytes would not be affected by the reagent and the blank matrix.Conclusions Certified reference materials for cholesterol and glycerol in aqueous solution have been prepared successfully.These materials are homogeneous and stable, and the certified values are reliable.Therefore the materials have been approved to be the Certificate Reference Materials of GBW 09823, GBW 09824, GBW 09825, GBW09826, GBW09827 and GBW 09828.
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Objectives To investigate the factors influencing long-term quality of life (QOL)of patients with first-episode ischemic stroke(IS)and partial side limb dysfunction.Methods 126 cases of the first ischemic stroke patients with partial side limb dysfunction admitted to hospital from November 2012 to July 2013 in Shanghai First People's Hospital were selected.General information of patients was collected and evaluated using NIH Stroke Scale(NIHSS)and Modified Rankin Scale(MRS).Following-up was conducted using NIHSS,MRS,stroke specific quality of life (SS-QOL) and Hamilton Depression Scale (HAMD) during 2-3 years after stroke Factors related to long-term QOL were screened by single factor analysis,then factors influencing QOL by multiple stepwise regression analysis.Results The average QOL score of patients with first IS partial side limb dysfunction was(181.5 ± 46.4)points scale.In each single scoring,the scale was(10.4±4.3)points in energy,(10.8±4.2)points in family roles,(21.8±6.2)points in language,(22.5 ±7.6) points in activity,(18.5±6.3)points in mood,(10.1±4.4)in personality,(19.2±5.9)points in self-care ability,(16.1 ± 7.0) points in social roles,(11.65 ± 3.31) points in thinking,(19.1 ± 6.6) points in upper limb function,(14.0 ± 2.0) points in visual acuity,(8.7 ± 4.1) points in work.The multiple regression analysis showed that the influencing factors of life quality included long-term NIHSS evaluation(β=-0.376,P＜0.01),HAMD evaluation(β=-0.375,P＜0.01),hypertension history(β=-0.178,P＜0.05).HAMD evaluation affected 9 fields of QOL,and NIHSS as long-term evaluation affected 6 fields of QOL.Conclusions Predictive factors for declined QOL of first-episode ischemic stroke patients with partial side limb dysfunction include higher NIHSS score,severer depression after long-term stroke and combined hypertension in the early stage.These indicate that recovering of body structure and function injury,control of hypertension,effective prevention and treatment of post-stroke depression maybe important measures for improving life quality of ischemic stroke patients with partial side limb dysfunction.
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Objective To prepare the serum reference materials for total thyroxine .Methods Individual blood samples were collected from 13 healthy donors (7 males and 6 females) aged from 20 to 50 years old, and the sera were separated and mixed into 4 serum pools according to the concentration of thyroxine.The materials were tested for homogeneity and stability using routine methods .The method of isotope dilution liquid chromatography tandem mass spectrometry ( ID-LC/MS/MS) was used to determine the concentration of thyroxine .The candidate reference materials were also measured by four conventional methods to analyze the commutability of the materials .Results It showed that the four candidate reference materials were homogeneous and commutable in four conventional methods and they were tested to be stable for at least 1 year at -70 ℃using the isochronous stability study .The certified values ( reference value ± expanded uncertainty ,nmol/L) were:75.9 ±1.8,105.3 ±2.2,114.7 ±2.1 and 187.4 ±2.9.Conclusions Certified reference materials for serum thyroxine have been prepared .These materials have been approved to be the Certificate Reference Materials of GBW 09127,GBW 09128,GBW 09129 and GBW 09130.
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Objective To investigate and analyze the reasons of fa0ilure in external quality assessment(EQA) for routine chemistry and provide the basis for the corrective and preventive actions.Methods Based on the network system of NCCL EQA the reasons of failure in 2013 national routine chemistry external quality assessment program were investigated,among which the reasons were classified and analyzed with seven sources of problems which were clerical errors,methodological problems,equipment problems,technical problems,EQA materials problems,EQA Evaluation problems and unable to explain after investigation.Results The return rate of this root cause investigation for each analyte ranged from 33.3％ to 80.0％.The major reason for unacceptable analyte included clerical errors (6.5％) (decimal point position error:70.1％;unit error:20.8％;instrument or method coding error:8.1％),methodological problems (45.1％)(calibration:54.2％;reagent:38.0％;EQA material:7.8％),equipment problems (28.5％) (no regular maintenance:98.0％;pipeline error:2.0％),technical problems (8.2％) (do not follow SOP:80.4％;EQA material redissolve error:10.6％;placing order error:9.0％) and unable to explain (11.7％) (system error:68.2％;random error:31.8％).There were no EQA materials problems or EQA Evaluation problems in this survey.Analysis systems' grouping statistics were implemented for seven analytes including sodium,chlorine,phosphorus,direct bilirubin,total iron binding capacity,copper,and zinc.Unsatisfied EQA proportions of mating system were lower than nonmatching ones for the majority of analytes.Conclutions Further work on EQA should be undertaken by clinical laboratories.Laboratories should use reagents with high quality as well as improve the operation technology and sense of responsibility.Only in this way,can the accuracy and reliability of testing results be guaranteed.
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Objective To assess the interference by calcium dobesilatein 7 peroxidase-baseduric acid assays and to determine its clinical significance.Methods In the in vitro experiments, uric acid in pooled serum with final concentrations of calcium dobesilate additions (0, 2, 4, 8, 16, 32, and 64μg/ml) were measured by 7 peroxidase-based assays.Percent Bias (%) was calculated relative to the drug-free specimen.In the in vivo experiments, changes in serum uric acid and calcium dobesilate concentrations were observed before and after calcium dobesilate administration ( baseline, 0 h, 1 h, 2 h, 3 h, 4 h, 6 h ) involunteers.The interference in different assays was assessed compared with LC-IDMS/MS method. Calcium dobesilate levels in 40 specimens from those taking calcium dobesilate were measured by HPLC method.Of the 40 specimens, 10 were selected to analyse the levels of uric acid by both peroxidase and UV measurement method to assess the impact in clinical status.Results In the in vitro study, concentrations of uric acid measured by 7 peroxidase-based assays were reduced by -6.3%to -21.2%compared with drug-free serum, when theconcentration of calcium dobesilate was16μg/ml.In the in vivo study, comparedto UA levels at 0 h, the biasesof serum uric acid determined by peroxidase method after calcium dobesilate administration(1 h, 2 h, 3 h, 4 h, 6 h) were of -3.33%, -6.79%, -7.49%, -6.07%, -4.09%, respectively.The observed uric acid concentrations for 8 participants measured by enzymatic assays were inhibited by -3.75% to -6.89% at 0 hour and by -16.9% to-22.22% at 2 hours relative to the concentrations measured by the LC-IDMS/MS method. Conclusions Calcium dobesilate produced a clinically significant negative interference with uric acid in all peroxidase-based uric acid assays,which may result in false evaluation of uric acid level in clinical status.Significant differences in the degree of interference were observed among the assays.
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Objective To evaluate the trueness of 13 routine measurements for serum uric acid and the role of reference method in improving harmonization and trueness among routine measurement systems. Methods The research is related to the reagent evaluation.Usingisotope dilution liquid chromatography tandem mass spectrometry ( ID-LC/MS/MS) method as the comparison method, Wako, Sekisui, DiaSys, Maker,Dirui,Leadman,BSBE,Biosina,Mindray,MedicalSystem,LongMarch,and Kehua 13 kinds of uric acid kits were chosen as the evaluation methods with Hitachi 7170A as the analyzer.serum uric acid in 40 fresh frozen serawere collected from clinical laboratory of Beijing hospital in 2014,coveringboth physiological and pathological status ( 80 -940 μmol/L ) .19 kinds of prepared materials and the 40 fronzen sera were measuredby comparison method and evaluation methods and linear regression analysis was made for the results.The performance of evaluation methods was revealed and recalibration was performed on every evaluation methodby the linear regression equation.The variation of percent bias(%) of the uric acid values in 19 preparation materials was compared.Results All test methods demonstrated good precision ( CV0.998, P<0.01) with the comparison method when measuring uric acid values in 40 fresh frozen sera The meanpercent bias was 0.17% ( -3.06% -7.31%).After recalibration, 4 of 19 samples with no matrix effect values percent bias reduced and met the demands of quality ( <4.8%) induced from biological variation.Conclusion All test methods demonstrated good trueness and their calibration traceability was verified.Recalibration using reference method or standard reference materials contributes to harmonization among methods.
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Objective To evaluate the analytical quality of different analytical systems in measuring seven kinds of sero-enzymes consisting of Alanine Aminotransferase(ALT), Aspartate Aminotransferase (AST),γ-Glutamyltransferase(GGT), Lactate Dehydrogenase(LDH), Creatine Kinase(CK), α-Amylase (AMY) and Alkaline Phosphatase(ALP).Methods Data from 2013 routine chemistry external quality assessment (EQA) and Enzymes Trueness Verification(ETV) were collected.1 450 and 165 participating laboratories were selected respectively for investigation.Analytical systems of participating laboratories were classified into 6 kinds,i.e.imported matching system(AI), domestic matching system(AH), systems consisting of imported reagents and corresponding calibrators(BI), systems consisting of domestic reagents and corresponding calibrators ( BH ) , unmatched systems using imported calibrators ( CI ) and unmatched systems using domestic calibrators ( CH ) .Total error, bias and coefficient of variation within laboratories ( CVI) were calculated from the data of 2013EQA and ETV The proportion of laboratories meeting the desirable and the optimal criteria derived from biology variation were analyzedby EXCEL2010 with coincidence rate (CR) above 85% as evaluation criterion.Results The AI and CI occupied more than 70%among six systems, CH occupied approximate 15% and the other systems were less than 10%.The range of the average of ETV′s total errors , EQA′s total errors, absolute value of bias and CVI of seven kinds of sero-enzymes were 6.2%-27.8%, 4.0%-7.0%, 4.2%-25.1% and 3.6%-4.6% respectively. Accuracy, bias and within-laboratory imprecision were judged by CR of ETV′s total errors, ETV′s bias, CVI and EQA′s total errors respectively and comparability between different systems was evaluated.It turned out that the results of analytical systems of enzymes except ALP were comparable, the accuracy of systems of enzymes except AMY, ALP and GGT, LDH of AI, the within-laboratory imprecision of enzymes except LDH, AMY, ALP and AST of AI, CH could meet the desirable criteria.The bias of all systems of seven kinds of sero-enzymes were undesirable.Conclusions The analytical quality of routine testing of seven kinds of sero-enzymes could fulfill the clinical requirement generally in China.