ABSTRACT
Objective@#To establish a method of calibration and performance verification of the GCMS-QP 2010 Ultra gas chromatography-mass spectrometer for urine organic acid detection after annual maintenance, so as to ensure that the performance of the detection system can continuously meet the detection needs. @*Methods@#According to the requirements of the equipment manufacturer and the Calibration Specifications for Benchtop Gas Chromatography-Mass Spectrometer, the gas chromatography-mass spectrometer was calibrated after annual maintenance. According to the CNAS-CL02-A003 Guidance on the Application of Accreditation Criteria for the Medical Laboratory Quality and Competence in the Field of Clinical Chemistry, the analytical performance of the maintained gas chromatography-mass spectrometer was validated. @*Results@#The calibration results of quality range, quality accuracy, resolution, signal-to-noise ratio and repeatability were all met the requirements. The detection results of internal quality control materials were under control, and the results of retained samples kept unchanged. @*Conclusion@#The calibration and performance verification method of the gas chromatography-mass spectrometer for urine organic acid detection after annual maintenance is established successfully, which is of importance for providing accurate and reliable results of urine organic acid.
ABSTRACT
Objective To evaluate the measurement uncertainty of the detecting procedure of amino acids and carnitines by the Waters ACQUITY TQD tandem mass spectrometer and PerkinElmer NeoBaseTM non‐derivatized MSMS kit ,and to discuss the meaning of evaluation .Methods According to the method provided by the Medical Laboratories‐Evaluation and Expression of Measurement Uncertainty ,the internal quality control was detected by using two different batch codes of kit for 20 d ,once before and after the routine sample detection on each working day ,the detector were randomly changed ,and then the measurement uncer‐tainty introduced by measurement reproducibility was calculated;the amino acid external assessment quality control data in 20 times of neonatal hereditary metabolic disease tandem mass spectrometry screening provided by the National Center for Clinical Laborato‐ry in 2014 and 2015 ,and the same and 16 times of carnitines external assessment quality control data were performed the statistics , and then the measurement uncertainty introduced by bias was calculated .Next the relative standard uncertainty and the relative ex‐panded uncertainty according to the measurement uncertainty introduced by bias and measurement reproducibility were calculated . The allowed total error indicators of amino acid and carnitines external quality assessment in the neonatal hereditary metabolic dis‐ease tandem mass spectrometry screening by the National Center for Clinical Laboratory were used as the target expanded uncer‐tainty .Results The relative expanded uncertainties of citrulline ,methionine ,phenylalanine ,propionyl carnitine ,octanoyl carnitine , dodecanoyl carnitine ,palmitoyl carnitine and octadecanoyl carnitine were 19 .1% -26 .1% (k=2) ,which were smaller than the tar‐get uncertainty .The relative expanded uncertainties of leucine ,tyrosine ,valine ,free carnitine were 31 .0% -43 .3% (k=2) ,which were greater than the target uncertainty .The uncertainty of isovaleryl carnitine needed to be estimated separately .Conclusion As‐sessing the measurement uncertainty of the detecting procedure of amino acids and carnitines by the non‐derivatized tandem mass spectrometer method can not only provide an opportunity for continuously improving the detection quality ,but also can help the ex‐perimental technique staffs to interpret the test data correctly and the clinician to use the detection reports correctly .
ABSTRACT
Hepatic fibrosis of rat was induced by CCl_4 and treated with tetrandrine(Tet). Results showed that Tet had obvious effect of anti-hepatic fibrosis which can be borne out by determining the activities of liver enzyme spectrum consisting of ALT,AKP,ChE,MAO and r-GT in serum. The meaurement can be observed dynamically, is noninvasive and more rapid,accurate and convenient than invasive hepatic biopsy. It provides valuable biochemical indexes for diagnosis,curative effect and prognostic judgement of hepatic fibrosis.
ABSTRACT
To investigate the mechanism of low responsiveness of cultured human intestinal epithelial cells (IECs) to LPS stimulation, IL-8 secretion level was detected by ELISA in supernatants harvested after the IECs were treated with LPS for 18h, and TLR4, TLR2, CD14 and MD2 mRNA were detected by reverse transcriptase-polymerase chain reaction(RT-PCR) and RNase protection assay(RPA). It was found that IL-8 was not detectable after IECs were treated with LPS and the expression levels of TLR4, TLR2, CD14 and MD2 mRNA of IECs were low and after exposed to LPS, the expressions of TLR4, CD14 and MD2 mRNA of IECs became further lower, whereas the expression of TLR2 mRNA didn't change obviously. The result suggests that low expressions of LPS signal transduction-associated receptors on IECs may be responsible for low response of IECs to LPS, so it confirms further that TLR4, CD14 and MD2 play important roles in transmembrane LPS signal transduction.