Objective To prepare the candidate reference materials for frozen mixed serum potassium, in order to calibrate and evaluate the conventional methods to achieve mutual recognition of the results.Methods Fresh sera without hemolysis,lipemia and choloplania were collected.Serum pools were packed in the freezing tube in the 1 000 (1 ml/per).Use the Single Factor Analysis of Variance(ANOVA) to evaluate the homogeneity.The short-and long-term stability [(2 -8℃,room temperature,37 ℃) and long-term (-80 ℃ ) ] were investigatedby linear regression analysis.The value was assigned by transfer from NIST SRM-956c using reference method by ICP-MS and uncertain was calculated.We observed the commutability of 25 fresh patient serum samples and 3 levels candidate RMs between reference method and three analyzed systems.The candidate RMs( refernce materials) were then distributed to 33 laboratories in Beijing to apply in routine assay by using different detection systems.Results By statistical analysis of the SPSS 17 statistical software, the F value of homogeneity test of each level candidate RMs was 0.247, 0.117, 0.162.All of them were less than F0.05 (9,20) =2.39;Stability can be last at least 12 months,30 days, 12 days and 4 days at -80 ℃, 2-8℃, room temperature and 37℃respectively.The definited values of three levels candidate RMs for potassium were (2.349 ±0.028) mol/L,(3.845 ±0.024) mol/Land (5.831 ±0.042)mol/L;Coordinate dots of 3 levels candidate RMs are all within 95% confidence interval range of 25 serums regression line.They have the same speciality as serum.In correctness verification survey of 33 clinical laboratory of conventional methods,97%bias in results The biases of 97%RMs were within the range of ±2.5%( ±1/2 CLIA′88Tea).Conclusion The homogeneity, stability and commutability of 3 levels candidate RMs all meet the requirement and the target values are assigned accurately.

Objective To establish a method for the determination of serum potassium using isotope dilution inductively coupled plasma mass spectrometry.Methods Frozen human serum pools of different potassium concentrations were prepared from healthy donors of Chao-yang Hospital laboratory in 2010 Serum samples were diluted with 1％ HNO3 supplemented with 41K spike and isotope ratio was measured after selection and optimization of ICP-MS analysis conditions.Serum 39K concentrations were calculated by interpolation method.3 different serum samples were used to evaluate the precision of the method.Standard Reference Material 909b Ⅰ and Ⅱ of National Institute of Standards and Technology were used to evaluate the accuracy.The recovery was evaluated through 2 serum samples added standard material for potassium,uncertainty was calculated.Results The analytical precision of serum potassium measurement was 0.14％ to 0.11％.The results of SRM909b Ⅰ and Ⅱ gave the coefficients of variation (CVs) of 0.39％ to 0.32％.Data was consistent with the certified value and the CV was + 0.12％ and + 0.49％ respectively.The recovery was 99.68％ to 100.12％ for 2 different serum samples.Conclusions ID-ICP-MS method was successfully established to measure the serum potassium concerntration precisely and accurately,it is an ideal method for the accurate determination of inorganic elements.

Glycated hemoglobin is internationally recognized as the gold standard for assessment of long-term glycemic status in diabetic patients,but our determination of glycosylated hemoglobin standardization work is still at primary stage at present.Consistency and accuracy of glycated hemoglobin results are still needed to be solved.

Objective To select the calibrator for the conventional measurement system of serum a-Amylase (Amy).Methods The Amy levels of forty frozen serum samples were detected by the IFCC reference method (reference system),the conventional system A which used the Bioassay routine reagent and Randox calibrator,and was calibrated by the Roche PNPG7 method,and the conventional system B which used the Bioassay routine reagent and Randox calibrator,and was calibrated by the Rondox liquid stable PNPG7 method,respectively,and the acceptability of the two conventional systems was evaluated.Results The regression equations of the measurement values between the IFCC reference method and the conventional systems A and B were Y =0.964X +0.376 and Y =1.095X + 3.131,respectively.Among them,X and Y represented the results of the IFCC reference method and the conventional system,respectively.Compared with the IFCC reference method,the results of the conventional system A was reliable.Condusion With the guidance of the IFCC reference method,the domestic biochemical reagents matched with the suitable calibrators may provide the acceptable results.

Objective To investigate the measurement of serum calcium by flame atomic absorption spectrometry (FAAS) and to validate the method for use as a candidate reference method. Methods Serum was diluted by 50 fold with 50 mmol/L hydrochloric acid containing 10 mmol/L LaCl3 and analyzed for calcium on an AA 6800 atomic absorption spectrophotometer. Dilution solutions and FAAS conditions were optimized and the performance of the method was evaluated. Results The method showed within-run, between-run and total CVs of 0. 31%～0.38%, 0.16%～0.30% and 0.35%～0.49%, respectively, and analytical recoveries ranging 98.9%～101.1%. No significant interferences were detected. Conclusions A FAAS method for the measurement of serum calcium has been established. The method is simple and accurate and may be used as a candidate reference method for serum calcium.

Objective To prepare the frozen human serum pools for AFP reference materials through quantity value transmission from several analysis systems . Methods Method establishment. According to the requirement of preparation for the national standard materials , the studies of homogeneity and stability of frozen human serum pools for AFP reference materials were carried out .The commutability of prepared AFP reference materials and WHO AFP 72/225 reference material were assessed .By use of four automated chemiluminescence analysis systems , the prepared reference materials and different dilutions of WHO reference material 72/225 were tested in the same run.The values of prepared AFP reference materials were assigned by comparing these results and the uncertainty was evaluated .Results The three levels of AFP reference materials were tested to be homogeneous .The long term stability had been observed at -80℃for 14 months.The different dilutions of WHO AFP 72/225 reference material and three levels of prepared reference materials were commutable with patient serum samples among the four analysis systems .Through multiple system quantity value transmission and total uncertainty evaluation , the assigned values ( IU/ml) of three levels of AFP reference materials were 23.0 ±3.0, 93.2 ±7.2, ( 26.1 ±2.4 ) ×102 respectively.Conclusions The three levels of AFP reference materials were homogeneous and stable in accordance with requirement of preparation for national standard materials .The assigned values were reliable.The materials showed accepted commutability across 4 analytical systems.These materials had been approved as the national certified reference materials .These reference materials could be applied for the calibration or calibration verification of clinical analytical systems and the external quality assessment schemes for clinical laboratories.

Objective To prepare serum calibrators for CRP measurement.Methods Fresh serum without infectious diseases , hemolysis, lipemia and choloplania were collected and divided into 3 groups, low, medium, and high, according to the CRP concentration.Each serum pool was mixed , filtered, sterilized and aliquoted.The materials were tested for homogeneity and stability.The values of the CRP was assigned by particle enhanced immunonephelpmetry , and calibrated with international reference materials.The expanded uncertainty was evaluated.Results The materials were tested to be homogeneous (Ubb﹤Ur, P>0.05) with Ubb values being 0, 0.125, 0, Ur values being 0.046, 0.213, 0.785, and F values being 0.803, 1.686, 0.966 in CL, CM, CH groups respectively.Stability study, where F values are 0.609, 0.259, and 1.557 at 22-25℃, 1.217, 4.583, and 0.893 at 2-8℃(P>0.05), showed that the materials were stable for at least 3 days at 22-25 ℃or 30 days at 2-8 ℃, respectively.The certified values of the 3 levels materials for CRP were ( 2.64 ±0.14 ) , ( 31.17 ±0.63 ) , ( 73.85 ±1.74 ) mg/L, respectively.Conclusion The calibrators prepared for serum CRP measurement were homogeneous , stable and accurately assigned and can be used to calibrate the CRP measure system.

OBJECTIVE To screen for mutations in a Chinese pedigree affected with hypokalemic periodic paralysis. METHODS The proband and nine family members were enrolled for the analysis of CACNA1S and SCN4A gene mutations. Genomic DNA was extracted from peripheral blood samples. The coding regions of the two genes were amplified with PCR and subjected to Sanger sequencing. Potential impact of suspected mutations was predicted with Bioinformatics software. The mutations were also verified among 100 healthy controls. RESULTS The proband and 5 family members (including 5 males and 1 female) had presented with episodes of flaccid paralysis accompanied by low serum potassium. Genetic testing has identified a c.664C>T (p.Arg222Trp) mutation in the proband, which has been reported previously. The same mutation was identified in other 5 affected members from the family. No mutation of the CACNA1S gene was detected. CONCLUSION The c.664C>T mutation of the SCN4A gene probably underlies the hypokalemic periodic paralysis in this family. All patients from the family have shown a complete penetrance of the disease.

Acute lymphoblastic leukemia (ALL) is a malignant clonal disease, its treatment methods include chemotherapy, hematopoietic stem cell transplantation, immunotherapy and molecular targeted therapy. Clinically, ALL patients need to get complete remission through chemotherapy, and then choose the other treatment according to the patient's condition. But the drug resistance has been a biggest obstacle in treatment of ALL. There are many research reports about drug-resistant of ALL at present. In this review, the classic drug resistance mechanisms, such as membrane transporter, gene modifications and some newly finding mechanisms including such as bone marrow microenvironment and Micro RNA and so on are summarized.
Bone Marrow ; physiology ; Cellular Microenvironment ; Drug Resistance, Neoplasm ; Humans ; Membrane Transport Proteins ; physiology ; MicroRNAs ; genetics ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; drug therapy

OBJECTIVETo analyze the heterogeneous biological characteristics of acute leukemia (AL) patients with mistranslation expressed lymphoid and myeloid-related antigens, and it's prognosis-related factors.

METHODSTwo hundred and fourteen AL patiens with mistranslation expressed lymphoid and myeloid-related antigens were grouped according to immunophenotypes, and the heterogeneous biologic charecteristics and prognosis related factors were analyzed, moreover the survival curves were drawn to analyze the survival of patiens.

RESULTSThe immunophenotype in 214 cases was mainly cross-expression of myeloid and B lineage antigen (118 cases), followed by cross-expression of myeloid antigen and T lineage (88 cases), while the cross-expression of myeloid, T and B lineages, was less (only 8 cases). In ALL patiens with cross-expression of myeloid antigen, the CD33 was main type; while in AML patients with cross-expression of lymphoid antigen, CD7 was main type of lineage antigen, CD19 was main type of B lineage antigen. Among 214 AL patients, the cross-expression of CD55 and myeloid antigen was found in 30 cases, the cross-expression of CD7, CD19 and CD74 was observed in 6 cases, the cross-expressions of CD7, CD34 and CD56 was detected in 4 cases. Among AML patients with lymphoid antigen expression, the recurrent chromosmal abnormalities were found in 16 cases; among ALL patients with myeloid antigen expression, the recurrent chromosomal abnormalities were observed in 10 cases. The mistranslation antigen expression existed in 26 patients with recurrent chromosomal abnormalities, the mistranslated CD33 and CD13 in ALL patients with myeloid antigen expression was common, while the mistranslated CD2, CD56 and CD19 in AML patients with lymphoid antigen expression was common. As compared with patients without lymphoid antigen expression, the survival rate decreased significantly in patients with mistranslated CD7(+) and CD34(+) (both P<0.05). The logistic regression analysis showed that CD7, CD34 were main influencing factors for prognosis of AL patients (both P<0.05).

CONCLUSIONThe AL with mistranslation expressed lymphoid and myeloid antigens is a special kind of leukemia which possesses the heterogencous biological characteristcs and unique prognostic features, thus the immunophemotype of AL patients should be detected by flow cytometry. The existance of mistranlation-expressed differatiation antigens such as CD7 and CD34 is mainly influencing factors for the prognosis of AL patiens.