Isotope dilution mass spectrometry is a reliable principle for small molecule analyte measurements.It is a precise,accurate method with very high specificity,which is very suitable for lowconcentration steroid hormones tests.The published reference methods are all based on this principle so far.In this paper,the applications of isotope dilution mass spectrometry in the determination of steroid hormones were reviewed.

Objective To investigate preanalytical and intraindividual biological variations of 19 biochemistry analytes. Methods For the study of preanalytical variations, 10 consecutive blood specimens were taken from each of 21 individuals and the specimens were taken from different arms and with various evacuated blood tubes and venous occlusion durations and processed with different storages before and after centrifugal separation of serum. Another 3 aliquots of blood, each at an interval of 1 week, were taken from the individuals for the study of intraindividual biological variations. All the serum samples were analyzed in duplicate for 19 biochemistry analytes. Analysis of variance was performed on the results for the estimation of preanalytical and biological variations. Results Various preanalytical treatments or factors caused some systematic variations but random specimen errors were the main contributors of preanalytical variations. Chloride, sodium and calcium showed preanalytical variations of less than 1% and other analytes ranging from 1%-7%. Different analytes showed varied intraindividual biological variations. The least biological variations ( <2% ) were observed on chloride, sodium and calcium and the largest ( >20% ) on bilirubin,triglycerides, alanine aminotransferase and creafine kinase. Conclusions Preanalytical variations under laboratory settings in China and intraindividual biological variations in Chinese for 19 biochemistry analytes have been estimated. These data will be useful in the estimation of measurement uncertainty and the interpretation of clinical laboratory results.

This article summarized recent correlative literatures focusing on international standards on glycated hemoglobin.The basic concept,determination of glycated hemoglobin,the present review in laboratory measurement and metrological traceability was introduced.The international community has established reference system and metrological traceability to the International System of Units on HbA1c.Determination in glycated hemoglobin is still in incipient stage in our country.Both clinical laboratorians awareness and clinical determination need to be strengthened.

Objective to evaluate the analytical performance of 7 open automatic biochemistry analysis systems in terms of precision,linearity,anti-interference ability and trueness on determination of cholesterol.Methods Performance verification test.There were 7 open analysis measurement systems composed of 7 kits as well as calibrators from Biosina,Baiding,Fosun,Dongou,Kehua,Maker and Wako company respectively,and Hitachi 7170 automatic analyzer were chosen as test systems.The repeatability CV and inter-lab CV were assessed according to Clinical and Laboratory Standards Institute (CLSI) protocol EP5-A2.The linearity range was evaluated on the basis of CLSI EP6-A,the series concentrations of cholesterol were 0,2.07,4.14,6.21,8.28,10.35,12.93,20.69 and 25.86 mmol/L cholesterol.Hemoglobin,ascorbic acid (vitamin C) and intralipid were applied as interfere materials in interference testing according to CLSI EP7-A2.The trueness was evaluated on the basis of China national lipids standardization program,the concentrations of 10 samples ranged from 2.88 to 5.42 mmol/L measured by reference methods.Results When the low level sample (2.71 mmol/L) measured,the repeatability CV were 0.54％,0.79％,0.56％,0.51％,0.56％,0.48％ and 0.49％ respectively,intra-lab CV were 1.00％,1.06％,1.28％,0.89％,1.08％,1.13％ and 1.05％ respectively.When the high level sample (5.12 mmol/L) measured,the respective repeatability CV were 0.40％,0.41％,0.51％,0.48％,0.47％,0.45％ and 0.47％,the respective intra-lab CV were 0.82％,0.69％,1.27％,0.70％,0.70％,1.08％ and 0.69％.The upper limits of linearity range of A,B,D,F was 12.93 mmol/L and for C,E,G was 20.69 mmol/L.There is no significant interference on 7 systems with chyle concentration of 1.6％ or hemoglobin concentration of 4 g/L.Given the interference bias ≤ 4％,the interference concentrations of ascorbic acid were 228,215,225,2840,2840,217 and 2840 μmol/L respectively.In trueness verification experiment,the bias of 7 systems all met the target value (≤ 3％).Conclusion The analytical performance of 7 systems in terms of precision,linearity,trueness and anti-interference all met the requirements of clinical specifications.The performance of anti-interference and measurement trueness of several systems could be improved.

Objective To assess the effects of fenofibrate on myocardial remodeling in obese rats by echocardiography.Methods Twenty-six SD rats were fed with high fat chow to establish twenty obese rats models,which were randomly divided into two groups:obesity group (OB group,n =10) and fenofibrate group(F group,n =10).The same week-old SD rats group (n =10) was also randomly selected as normal control group.F group was given fenofibrate 60 mg · kg-1 · d-1 for 8 weeks,the other groups were given normal saline.Echocardiographic scan was performed in each group at the beginning and ending of the experiment.Twenty-four weeks later,all rats were executed and the cardiac muscle was used to histological inspect.Results After the experiment,compared with the control group,the body weight,the ventricular thickness,interventricular septal thickness and the left ventricular mass in OB group were significantly increased than those of control group(P ＜0.01),the E/A ratio was significantly decreased(P ＜0.01).Histological detection showed that myocardial structure was disordered,and that interstitial collagen was deposited in the myocardium.Compared with OB group,the parameters all above in F group were significantly improved (P ＜0.01).Left ventricular mass from echocardiography correlated well with the results from pathologic specimen (r =0.98,P ＜0.01).Conclusions Fenofibrate has beneficial effects on preventing myocardial remodeling.By general echocardiography,the effects can be assessed comprehensively and accurately.

Objective To evaluate the commutability of certified reference material IRMM ERM-DA 471/IFCC for cystatin C measurement among 8 methods.Methods 46 individual samples used for the commutability study were residual serum samples collected from clinical laboratories.The individual samples interspersedwith pooled sera and the certified reference material IRMM ERM-DA 471/IFCC and the whole set of samples was divided into 2 subsets for measurements in 2 days.The measurements were performed by8 different methods o.The samples were measured in duplicate order.Calibration was performed every day. Passing-Bablok regression was performed to compare the slopes and intercepts of mean values of the serum samples derived from different methods. Pearson correlation cofficient was also calculated. Deming regeression and 95%confidence intervals were calculated to evaluate the statistics commutability of ERM-DA 471/IFCC.The minimal specification of bias derived from biological variations was calculated to evaluate the clinical commutability.Results The within-laboratory CVs of pool sera ranged from 0.5% to 4.0%.The Passing-Bablok slope ranged from 0.765 to 1.311 and intercepts ranged from -0.04 to 0.241.The determination coefficient of Pearson regression ranged from 0.988 to 0.999.Deming regeression and 95%confidence intervals demonstrated commutability of ERM-DA 471/IFCC in 4/28 (14.3%) methods pairs. The minimal specfication bias ( 5.12%) demonstrated commutability of ERM-DA 471/IFCC in15/28 (53.6%) methods pairs.Conclusions The ERM-DA 471/IFCC domonstrated poor commutability between some methods pairs. The commutability of ERM-DA 471/IFCC should be evaluated before used as calibrators.

Objective To explore the effect of kidney transplantation from donation after brain death (DBD) donors with terminal acute renal failure (ARF).Method The clinical data of kidney transplantation from DBD donors with ARF were retrospectively analyzed,and only standard criteria donors (SCD) were included.The results of kidney transplants from ARF donors were compared with those of kidney transplants from DBD donors with normal renal function (serum creatinine ＜ 133μmol/L) performed from January 2012 to March 2014.Result There were 13 donors with ARF and 27 donors with normal renal function (non-ARF donors).The ARF donors had significantly higher terminal serum creatinine than the non-ARF donors (394.9 ± 176.8 vs.75.4 ± 28.6 μmol/L,P＜0.001),but the initial serum creatinine (79.1 ± 17.2 vs.71.0 ± 22.8 μmol/L) and the best creatinine clearance rate (128.3 ± 33.0 vs.129.8 ± 46.8 ml/min) of two groups showed no significant difference (P＞0.05).Twenty-six recipients received kidney transplants from ARF donors (ARF group) and 54recipients received kidney trangplants from donors with normal renal function (non-ARF group).There was no significant difference in the incidence of delayed graft function and acute rejection between ARF and non-ARF kidneys (0 vs.1.9％,and 11.5％ vs.7.4％,respectively).The ARF group had significantly lower estimated glomerular filtration rate (eGFR) at 1st month after transplantation (54.3 ± 16.9 vs.62.5 ± 14.2 mL·min 11.73 m 2,p =0.025),but the eGFRs of two groups were similar at 6th and 12th month after transplantation.During a mean follow-up period of 11.5 months (range 3 to 28 months),actual patient and graft survival rate for both groups were 100％.Conclusion Kidneys from DBD donors with terminal ARF have excellent short-term outcomes and may represent another potential method to safely expand the donor pool.

Objective To assess system deviation of HbA1c measurement in clinical laboratories in China by the national trueness verification project.Methods Bias assessing research.Two lots samples of human whole blood pools with different HbA1c concentration levels were prepared and sent to laboratories by dry ice package.Laboratories were asked to measure these samples in 5 repeats per set in three consecutive Wednesday separately,results were reported through Web-based software.Meanwhile the IFCC reference measurement procedure was applied to assign HbA1c reference values for the two lots samples.The following information or data were analyzed:measurement systems,intra-lab CVs and inter-lab robust CVs of all laboratories,inter-lab robust CVs and bias based on peer groups,et.al.The criterion of bias was set at ± 4.5％.Results 106 of 120 laboratories submitted results,including 88 using high performance liquid chromatography method,13 using immune turbidimetry method and 5 using enzymatic methods the intra-lab CVs of lot 201311 ranged from 0 to 4.6％,with median of 1.1％,while for lot 201312 the intra-lab precision ranged from CV0 to CV4.5％,with median of CV0.9％.The inter-lab robust CVs of 201311 and 201312 with single determinations were 5.6％ and 6.1％ and inter-lab robust CVs of 201311 and 201312 of each lab's average results were 5.9％ and 5.6％ respectively.The inter-lab CVs of group BIO-RAD,TOSOH,ARKRAY and PRIMUS at two level were less than 5％.For all laboratories,the percents of pass of 201311 and 201312 were 61/106(57.5％) and 56/106(52.8％) respectively.The pass ratio of each group on two lots were as follows:of group BIO-RAD were both 19/45 (42.2％),of group TOSOH were 85％ (17/20) and 75％ (15/20),of group ARKRAY were 71.4％ (10/14) and 50％ (7/14),of group PRIMUS were 6/8,5/8; of group immune turbidimetric method were both 46.2％ (6/13) and of group enzymatic were both 3/5.Conclusions There were improvement for the performance of trueness of HbA1c measurement in domestic laboratories,while some of them should be addressed.Academic,research institutions,EQA organizer,manufacturers and clinical laboratories should work together to achieve the standardization of HbA1c measurement.

Objective To analyze the incidence of BK virus (BKV) infection after kidney transplantation in our center and to evaluate the efficacy and safety of conversion treatment with Mizoribine (MZR) on BKV infection after kidney transplantation.Methods The information of recipients who received BK virus screening in hospital or outpatient during 2015-02 to 2016-12 in our center was retrospectively analyzed.The recipients positive for BKV were divided into experiment group (given conversion treatment with MZR) and control group (not given MZR conversion) according to the inclusion criteria.The negative rate of BKV,AR,hyperuricemia and the function of renal allograft during the conversion treatment with MZR were observed.Results 182 recipients accepted BKV screening during 2015-02 to 2016-12 and 68 cases were positive.The positive rate of BKV was 38.5 ％.The positive rate of peripheral blood specimens and midstream urine specimens was 7.1％ and 36.8％ respectively.Twelve recipients were positive for BKV in both peripheral blood specimens and midstream urine specimens.There were 27 recipients in experiment group and 36 cases in control group.Fourteen recipients positive for BKV became negative after MZR conversion in experiment group and the negative rate was up to 51.9％.The mean time of negative rate was 3.2 ± 2.7 (1-10) months after MZR conversion.During the conversion treatment with MZR,AR occurred in 1 case and was reversed by the impact therapy with Thymoglobulin in experiment group.The value of serum uric acid was maintained stable before and after MZR conversion under the action of uric-acidlowering drug.The renal function was kept stable in both experiment group and control group after renal transplantation.No deaths and renal allograft failure cases occurred in both groups during the research period.The 2-year survival rate for patients and kidneys was both 100％.Conclusion The incidence of BKV infection after kidney transplantation was high and the treatment scheme of MZR conversion was safe and effective.

Objective To summarize the puncture indications and the pathological type features of renal allografts biopsies in our center for evaluating its safety and diagnostic value .Methods The data of 773 percutaneous renal allograft biopsies in 629 kid‐ney transplants in the Pearl River Hospital of Southern Medical University from January 2005 to June 2014 were retrospectively an‐alyzed .Results The success rate of renal biopsy was 100% ,9 cases(1 .2% ) were complicated postoperative perirenal small hemato‐ma ,33 cases(4 .3% ) with gross hematuria and 1 case(0 .13% )with abdominal pain .Among the indications of 773 biopsies ,protein urine occured 205 cases(26 .5% ) of patient ,blood Cr increased in 187 cases(24 .2% )of patients ,protein urine simultaneously com‐plicating blood Cr increased ,in 313 cases of patients ,53 cases(6 .9% )had postoperative oliguria urinary ,and 15 cases(1 .9% )were get procedural biopsy .In the pathological types ,21 cases(2 .7% ) were normal ,179 cases (23 .2% ) were acute T cell‐mediated rejec‐tion after transplantation ,51 cases (6 .6% )were acute antibody‐mediated rejection ,205 cases (26 .5% ) were chronic T cell‐mediated rejection and 43 cases(5 .6% ) were chronic antibody‐mediated rejection;41 cases(5 .3% ) were drug toxicity ,29 cases(3 .7% ) were acute tubular necrosis(ATN) ,11 cases(1 .4% ) were relapsed or new nephropathy ;9 cases(1 .2% )were HBV related renal disease;39 cases (5 .0% ) were critical lesion and 145 cases(18 .8% )were others .Conclusion Rrenal allograft biopsy is safe ,it is important to the etiological diagnosis of renal disease after renal transplant ,which can guide the clinical treatment and improve the long term survival of renal graft and should be routinely carried out in clinic .