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.

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 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.

Objective To develop a candidate reference method for the determination of sodium in serum by inductively coupled plasma mass spectrometry method (ICP-MS). Methods Aluminum, as internal standard of sodium, was added into serum samples and sodium standard solutions by gravimetric analysis. The samples were digested by HNO3 and diluted, and its 23Na/27Al isotope ratios were obtained by ICP-MS. The sodium concentrations were calculated with the standard curve method in serum. Results The analytical recoveries of sodium were 100.67% and 100.15% respectively, and the precisions were 0.08% and 0.04% respectively for 2 different serum samples. The results of measuring sodium in serum of Standard Reference Material (SRM) gave the coefficients of variation (CVs) of 0.18% and 0.22% for 2 levels of standard reference material(SRM) 909b and 0.41%, 0.41% and 0.66% for 3 levels of SRM 956b. The relative deviations between the results and median of the certified value were 0.17% and 0.14% for 909b and -0.09%, -1.05%, -0.48% for 956b respectively. Conclusions The ICP-MS and aluminum internal standard method is proved to be not only precise and accurate, but also quick and convenient for measuring sodium in serum. It is promising to be a candidate reference method for determination of sodium in serum.

Objective To verify the trueness and assess the traceability of results from a routine chemistry system procedure for measurement of urea and ereatinine in serun.Methods Series of fresh frozen patieot sera,whose values of urea or creatinine were assigned by isotope dilution gas chromatography mass spectrometry (ID-GC/MS) or isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS),were chosen to be analyzed by a routine chemistry system.The measurement results of urea and creatinine by the routine chemistry system were used for linear regression analysis against the assigned values bv the ID-MS method to calculate the percentage deviation and assess the expected bias.Results For urea and creatinine,the linear regression equations between the routine chemistry system and ID-MS methods were Y =0.9890X + 0.0192 (R2 =0.9990) and Y =0.9815X-6.4794 (R2 =0.9989),and the average percentage bias were-0.41％ (P ＞0.05) and-4.20％ (P ＜ 0.05),respectively.The expected percentage bias at three medical decision levels were-0.46％,-0.83％ and-0.96％ for urea and -15.90％,-5.87％ and-2.95％ for creatinine.Conclusions The results of urea analyzed by the routine chemistry system were consistent with the ID-MS method,which suggested that the results of the routine system procedure could be traced to ID-GC/MS method.For creatinine,the bias between the results of routine procedures and the assigned values met the minimum acceptance criteria' derived from biologic deviations,which would be better if its specificity improved.

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 analytical performance of 7 homogeneous HDL-cholesterol reagents. Methods An altracentrifugation-HPLC method was used as the comparison method. Fourty fresh patient samples were analyzed by homogeneous methods and the comparison method. The homogeneous methods were all performed on a Hitachi 7170A chemistry analyzer according to the manufacturer's instructions, Precision, accuracy and total errors were analyzed. Results The homogeneous assays typically demonstrated within run coefficient variance(CV) of < 1%, and total CV of < 3%. Methods A, B and D showed average bias, bias at the medical decision points and total errors all within the NCEP performance criteria and method C and F unacceptable biases (-19.74% and 11.46%, respectively) and total errors according to the NCEP criteria. However, all the homogenous methods (A-F) had total errors of < 30%, as required by the US Clinical Laboratory Improvement Amendment (CLIA). Conclusions Homogeneous HDL-C assays have been shown to be reasonably precise, but discrepant results have been observed with some of the assays. Clinical laboratories should pay more attention on selecting and validating homogeneous HDL-C reagents.

To study the long-term toxicity of arginine esterase from Agkistrodon halys ussuriensis venom for the clinical application of arginine esterase in the future. Beagle dogs were used as experimental animals and were divided into control group, arginine esterase low dose group (0.06 u/kg), the middle dose group (0.18 u/kg) and high dose group (0.36 u/kg). Every group consisted of four dogs. The arginine esterase was given intravenously once a day for 180 days. Then three dogs in each group were sacrificed and the fourth one was fed without injecting arginine esterase for 15 days. The toxic reactions during treatment and recovery period were determined by evaluating and comparing the general criteria ( including locomotor activity, growth rate, appetite and death rate), clinical criteria (including blood test and urine test), pathological dissection and viscera coefficient of the treated animals and the control animals. There were no significant differences in general criteria. The clinical criteria of the treated animals were the same as those of the control animals except liver function. There were no significant differences in pathological dissection and viscera coefficient between the treated animals and the control animals except livers. The livers in high dose arginine esterase treated animals were swollen and vacuolated and there was significant difference in liver coefficient between them (P<0.05). The toxic symptom of liver disappeared after withdrawal of treatment. From these results, the non-toxic dose of arginine esterase for dogs was estimated to be 0.18 u/kg under the present study conditions and is about 15 times the clinical dosage for using the drug "Qingshuanmei" of which the main component is arginine esterase. The long-term toxicity test result indicates that the toxicity of pure arginine esterase is lower than that of "Qingshuanmei", suggesting that clinical use of the arginine esterase is safe.
Animals ; Anticoagulants ; toxicity ; Carboxylic Ester Hydrolases ; toxicity ; Crotalid Venoms ; enzymology ; toxicity ; Dogs ; Female ; Kidney ; drug effects ; pathology ; Liver ; drug effects ; pathology ; Male

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 .