1.Influencing factors and advices for glycosylated hemoglobin testing
Chinese Journal of Laboratory Medicine 2014;37(12):893-895
Since the beginning of clinical use in the 1970s,hemoglobin A1c (HbA1c) has become the standard tool for monitoring glycemic control in patients with diabetes.The role of the HbA1c test was broadened in 2010,when the American Diabetes Association added HbA1c as a diagnostic criterion for diabetes.However,hemoglobin variants,various clinical scenarios and drugs may yield false results that would mislead clinical diagnosis and treatment.
2.Screening of homoacetogen mixed culture converting H2/CO2 to acetate.
Kan LUO ; Bo FU ; Lijuan ZHANG ; Hongbo LIU ; He LIU
Chinese Journal of Biotechnology 2014;30(12):1901-1911
Homoacetogens are a group of microorganisms with application potential to produce chemicals and biofuels by the bioconversion of synthesis gas. In this study, we collected waste activated sludge samples to screen homoacetogens by Hungate anaerobic technique, and studied the effect of pH on acetate and alcohol production from H2/CO2 gas. The mixed culture contained Clostridium ljungdahlii, Lysinibacillus fusiformis and Bacillus cereus. Acetate concentration achieved 31.69 mmol/L when the initial pH was 7. The mixed culture containing homoacetogen could converting H2/CO2 to acetate, which provides an efficient microbial resource for the bioconversion of synthesis gas.
Acetates
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chemistry
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Bacteria
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classification
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Biofuels
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Carbon Dioxide
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Hydrogen
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Sewage
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microbiology
3.Performance verification of precision, trueness, and accuracy of self-developed detection system in ;clinical chemistry
Xiuming ZHANG ; Yongli FAN ; Dongmei WEN ; Jingli XIAO ; Lijuan KAN
Chinese Journal of Laboratory Medicine 2016;39(9):715-719
Objective To investigate the precision, trueness, and accuracy of self-developed detection system in clinical chemistry.Methods This was a methodological evaluation.Take serum creatine kinase( CK) for instance, 6 serum sampleswith different leves ( on the upper or lower limit of the reference range or close to the medicine decide levels ( MDLs) , were collected for within-run precision( repeatability) and within-laboratory precision ( intermediate precision ) experiments.5 proficiency testing ( PT ) samples, 5 samples assigned value by reference method, and 40 fresh-frozen serums were measured and compared with reference method for trueness verification.Drawing method evaluation decision chart, calculating total errors and sigma level evaluation experiment based on the CV, bias, and allowed total errors(TEa)were used to evaluate the accuracy performance.The precision, trueness, and accuracy were compared with the quality indicators.Results The within-run precision and within-laboratory precision were less than the highest requirement of Chinese industrial standard.The mean bias was -8.96%, didn′t reachthe required standard (5.5%).After taking corrective actions, all samples but one ( -5.8%) met the required standard. Compared with the reference method, the mean bias on the MDLs was less than TEa.The performance points of the method evaluation decision chart indicated excellence performance.The total errors on MDLs were 14.2%, 10.4% and 7.6%, less than 15%.The sigma levels on MDLs were 5.9, 7.5 and 15, also achieved excellent level. Conclusions The precision, trueness, and accuracy performance of CK measured by self-developed detection system achieved excellent level of the Chinese industry standard, and the same results were found from different evaluation methods.
4.T-wave characteristics of electrocardiogram in newborn Infants with different gestational age
Li LI ; Baodong PANG ; Yingyu LI ; Lijuan WANG ; Fenglan WANG ; Jin WANG ; Yanan KAN
Chinese Pediatric Emergency Medicine 2010;17(3):227-229
Objective To evaluated T-wave characteristics in newborn infants with different gestational age. Methods One hundred and forty-two newborn infants were divided into four groups based on the gestation age consisting of the 28~30 weeks group,31~33 weeks group,34~36 weeks group and 37~40weeks group, respectively. The T-wave characteristics of electrocardiogram were compared among the newborn infants of four groups. Results TV1 amplitudes ( mV, median ( interquartile range) ) of 4 groups were -0. 10( -0. 30~0. 10), -0. 10( -0. 30~0. 15), -0. 10( -0. 45~0. 25 ) and 0. 10( -0. 30~0. 70) ,respectively. There was a statistical elevation of TV1 amplitude with the increase of the gestational age. TV5 amplitudes( mV, median ( interquartile range ) ) of 4 groups were 0. 10 ( - 0. 10~0. 30), 0. 10 ( - 0. 20~0. 30) ,0. 15( -0. 05~0. 25) and 0. 10( -0. 10~0. 50) ,respectively. No significant differences of TV5 amplitudes were found among 4 groups. The incidences of low or inverted T-waves in leads I and aVL, or low and flat T-waves in all leads reduced significantly with the increase of the gestational age. Conclusion The TV1 amplitude and the incidence of abnormal T-wave in newborn infants are correlated to the gestational age,and TV5 amplitude is not correlated to the gestational age.
5.Performance verification of HbA1c determination by using affinity chromatography
Jiasi ZHOU ; Dongmei WEN ; Ying CHEN ; Quanzhong XU ; Minghuan SUO ; Lijuan KAN ; Yaqiong CHEN ; Xiuming ZHANG
International Journal of Laboratory Medicine 2014;(17):2359-2361
Objective To evaluate the precision,accuracy,linear range and anti-interference performance of HbA1c assay by u-sing Primus Trinity Ultra2 automated analyzer.Methods According to Document EP published in 2004 by American Clinical and Laboratory Standards Institution(CLSI)and relative literatures,the precision,accuracy,linear range and anti-interference perform-ance were evaluated.Results The within-run and between-run CVs of HbA1c determination were both less than that announced by manufacture.In the tests of samples with certain concentrations,all the results were within the verification range respectively.In the linear verification,regression equation between the theoretical and measured values demonstrated that r2 >0.95,and a value was within the range of 0.97-1.03.For Primus Trinity Ultra2 the limit of interference effect didn′t exceed the allowable error at the medical decision concentrations.Conclusion The precision,accuracy,linear range and anti-interference was evaluated of the Primus Trinity Ultra2 automating HbA1c all could meet the manufacture′s declaim and the clinical needs.
6.The relationship between glucose-6-phosphate dehydrogenase deficiency and type 2 diabetes
Lijuan KAN ; Jingjing LI ; Xiuming ZHANG ; Dongmei WEN ; Minghuan SUO ; Weijia WANG ; Jianyang WU
International Journal of Laboratory Medicine 2015;(16):2297-2300
Objective To explore the relationship between glucose-6-phosphate dehydrogenase deficiency and type 2 diabetes and to provide reference for clinical diagnosis,monitoring and treatment of Type 2 diabetes.Methods Subjects were selected from our hospital,including 173 cases of healthy volunteers assigned to the control group;1 95 cases with type 2 diabetes conforming to the diagnostic criteria of WHO were assigned to the diabetic group.97 cases were diagnosed with glucose-6-phosphate dehydrogenase deficiency in our hospital,of whom 82 cases were assigned to simple glucose-6-phosphate dehydrogenase deficiency group,and 1 7 cases were assigned to the diabetes with glucose-6-phosphate dehydrogenase deficiency group.The correlation of glucose-6-phos-phate dehydrogenase activity and diabetes was measured by each detected value.Results Compared with the control group,the glu-cose-6-phosphate dehydrogenase activity and RBC count in diabetic group were higher(P <0.05).Positive correlations between glu-cose-6-phosphate dehydrogenase activity and RBC count in the two groups were significant(P <0.05).HbA1c and FBG showed a significant positive correlation in the control group,diabetic group and diabeties with glucose-6-phosphate dehydrogenase deficiency group(P <0.05).But there was no significant correlation in the glucose-6-phosphate dehydrogenase deficiency group.The rate of screening for glucose-6-phosphate dehydrogenase deficiency in diabetes group was 3.6%,and the rate in the control group was 1. 1%.When HbAlc≥6.5%,the rate of screening for glucose-6-phosphate dehydrogenase deficiency in the diabetes group was signifi-cantly higher than that in the control group (χ2 =4.239,P =0.039).Conclusion The level of HbA1c is discordant with that of blood glucose in diabetic patients with glucose-6-phosphate dehydrogenase deficiency group.Diabetes leads to the increasement of the rate of glucose-6-phosphate dehydrogenase deficiency.The glucose-6-phosphate dehydrogenase activity of diabetic patients with non-glucose-6-phosphate dehydrogenase dificiency is higher than that of the normal group.It may be associated with the level of RBC or increase of compensatory.Further more,glucose-6-phosphate dehydrogenase activity may be a good indicator for controlling diabetes,which remains to be further studied.
7.Performance verification of laboratory-developed clinical chemistry system-Analytical measurement range and clinical reportable range
Xiuming ZHANG ; Yongli FAN ; Dongmei WEN ; Lijuan KAN ; Jingli XIAO ; Kang CHEN
Chinese Journal of Laboratory Medicine 2016;39(12):946-952
Objective To estimate the methodology for evaluating the analytical measurement range ( AMR) and the clinically reportable range ( CRR) in lab-developed system in clinical chemistry .Methods Method evaluation .Take serum CK for instance , a series of samples were prepared from both a specimen with a high concentration of the analyte of interest and a specimen with a low concentration for the following assays.Average slope method , linear dilution recovery method and the method recommended by Clinical and Laboratory Standards Institute ( CLSI ) EP6-A were used to established AMR in the lab-developed clinical chemistry system.Based on the maximum valid dilution of the specimen and the results of AMR , CRR were determined.One-half of the total error allowance ( TEa) of Chinese health standard was set up as allowance error (7.5%).Results X-Y scatter plot was made by assigning sample numbers to the horizontal axis and actual measured values to the vertical axis , which determined the upper limit of AMR was approximate 1 651 U/L.The results analyzed by average slope method indicated that the linear correlation between expected values and actual measured values was determined , the correlation (r), the intercept (a) and the slope (b) met the linear standard, and AMR was 5-1 699 U/L.The results analyzed by EP6-A indicated that the best fitting curve was obtained by using cubic polynomial method , and the linearity deviation of the minimum concentration was -77.1%, which exceeded one-half of TEa.Followed by the deletion of the maximum concentration , the resumed experiment was done .The results showed that the nonlinear coefficient c of quadratic polynomial and the nonlinear coefficient c and d of cubic polynomial have no significant difference to 0, and AMR was 7.5-1 458.0 U/L.By linear dilution recovery method , the linear correlation between expected values and actual measured values was determined , the correlation ( r) , the intercept ( a) and the slope ( b) met the linear standard , the recovery rates was between 100.0%and 104.8%, and AMR is 5 -1 699 U/L.The CRR was determined to be 5 -33 880 U/L, which met the standard of TEa . Conclusions Average slope method, linear dilution recovery method and EP 6-A method were all used to established AMR in lab-developed clinical chemistry system .Without complicated statistical analysis , linear dilution recovery method was suitable for clinical use .The linearity deviation of the minimum concentration analyzed by EP6-A did not meet the standard of the quality objective system , suggesting defects in the statistical analysis of the results .CRR was feasibly determined by using linear dilution recovery method align with AMR.
8.Evaluation of NT-proBNP assay performance on electro-chemiluminescence immunoassay system
Xiuming ZHANG ; Dongmei WEN ; Weijia WANG ; Fei LI ; Lijuan KAN ; Haizhong YAN ; Minghuan SUO ; Nengliang OUYANG
Chinese Journal of Laboratory Medicine 2011;34(12):1152-1157
ObjectiveTo evaluate analytical performance of NT-proBNP on Electro-Chemiluminescence Immunoassay system.MethodsThe precision,accuracy,limit of blank ( LoB ),limit of detection (LoD),functional sensitivity (FS),analytical measure range (AMR),maximal dilution rate,clinical reportable range(CRR) and the analytical anti-interference ability of NT-proBNP were evaluated according to EP documents issued by CLSI and related references.The analytical performance data were compared to quality standards declared by the manusfacturers.According to CLSI C28-A2,80 healthy volunteers,aged from 18 to 74, were chosen and divided into 4 groups on average for biological reference intervals verification.Results The within-run CV and total CV were 1.1% -2.2%and 1.5% -2.9% respectively.The deviations from controls distributed by National Center for Clinical Laboratory and affiliated calibrators were 2.7% -5.9% and 2.7% -7.5%,respectively.The results of LoB,LoD and FS were 2.5,7.8 and 8.8 pg/ml,respectively.AMR was 8 -35 126 pg/ml,and the most suitable dilution rate was 1∶ 2,so the CRR was 9 -70 252 pg/ml.428 μmol/L bilirubin,2 g/L haematoglobin and 2 200 FIU chyle didn't interfere with the NT-proBNP assay.Moreover,almost all the data from different age groups were in the range of biological reference intervals declared by the manusfacturers, except one test data (167 pg/ml).Conclusions The analyticalperformance of NT-proBNP analyzed on Roche Cobas E601electrochemiluminescence immunoassay systemisconsistentwiththestandarlswhichmanufacturershas proclaimed.The establishment of LoD,FS,maximal dilution and CRR for NT-proBNP assay could provide the quality assurance for clinical use and the biological reference intervals declared by manusfacturers could meet the clinical needs.
9.The interference evaluation of hyperlipidemia and hyperbilirubinaemia to HbA1c measurement with IE-HPLC method
Jinli XIAO ; Xiuming ZHANG ; Shengnan XU ; Minghuan SUO ; Quanzhong XU ; Yaqiong CHEN ; Jianyang WU ; Man LI ; Lijuan KAN ; Dongmei WEN
International Journal of Laboratory Medicine 2015;(17):2492-2494
Objective To investigate the interference of hyperlipidemia and hyperbilirubinaemia to HbA1c measurements by ion‐exchange high‐performance liquid chromatography(IE‐HPLC) method .Methods Fresh whole‐blood samples collected with EDTA‐K2 anticoagulant tubes were divided into four groups :control group(HbA1c<6 .2% ) ,diabetes group(HbA1c≥6 .2% ) ,hyperlipi‐demia group(TG 3 -20 mmol/L);hyperbilirubinaemis group (TBIL 21 -549 μmol/L) .HbA1c of these samples were measured with affinity chromatography(AC‐HPLC) and IE‐HPLC respectively .Results When HbA1c≤18 .7% ,r=0 .993 ;95% confidence interval(CI) of HbA1c results by using IE‐HPLC method was -0 .71 -0 .89 ;coefficient of variation was -5 .8% -6 .8% ;P=0 .198 and the difference was not statistically significant .When HbA1c< 16 .3% ,r= 0 .997;95% CI of HbA1c results with IE‐HPLC method is -0 .31-0 .67;coefficient of variation was -5 .8% -4 .3% .P=0 .000 and the difference was statistically signifi‐cant .No interference was detectded with the results ;When HbA1c was 16 .3% -18 .7% ,positive bias was observed with the re‐sults .When TG≤20 .78 mmol/L ,r=0 .995;95% CI of HbA1c results with IE‐HPLC method was -0 .26-0 .50 ;coefficient of var‐iation was -5 .5% -5 .8% .P=0 .000 and the difference was statistically significant .No interference was detectded with the re‐sults;When TBIL≤549 .3 μmol/L ,r=0 .990 ;95% CI of HbA1c results with IE‐HPLC method was -0 .08 -0 .63;coefficient of variation was -14% -4 .1% .P=0 .000 and the difference was statistically significant .When TBIL≤342 .1 μmol/L ,r= 0 .994 ;95% CI of HbA1c results with IE‐HPLC method was -0 .09-0 .50;coefficient of variation was -5 .5% -4 .1% .No interference was detectded with the results .When TBIL was 380 .7-549 .3 μmol/L ,negative bias was observed with the results .Conclusion Our data indicated that HbA1c measurement with IE‐HPLC method could resist the interference of hyperlipidemia;When TBIL≤380 .7 μmol/L and HbA1c<16 .3% ,the results could meet the needs of general clinical detection .Clinical staff should choose more specific HbA1c measurement method according to the patient's condition .
10.Study on chromatography-efficacy relation of Zanthoxylum nitidum on gastric cancer cells.
Qingrong SHEN ; Huixue HUANG ; Honghong WANG ; Lijuan CAO ; Kan FENG ; Yuehua YE ; Huagang LIU
China Journal of Chinese Materia Medica 2011;36(19):2693-2696
OBJECTIVETo develop a method for elucidating " chromatography-efficacy" relation of the extract of Zanthoxylum nitidum on the gastric cancer cells.
METHODAfter obtaining the tumor inhibition rate and fingerprint peak data through MTT and HPLC, "chromatography-efficacy" relation was established by an appropriate statistical method.
RESULTThe gastric cancer "chromatography-efficacy" relation of Z. nitidum was established by step-back technique.
CONCLUSIONThe "chromatography-efficacy" relation has statistically significant and practical significance, so it has reference value in some way.
Antineoplastic Agents, Phytogenic ; analysis ; pharmacology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Chromatography, High Pressure Liquid ; methods ; Drugs, Chinese Herbal ; analysis ; pharmacology ; Humans ; Stomach Neoplasms ; drug therapy ; physiopathology ; Zanthoxylum ; chemistry