Plasm trimethylamine-N-oxide level and association with lesion severity in coronary heart disease patients with type 2 diabetes mellitus / 中华心血管病杂志

Objective: To investigate the association between trimethylamine-N-oxide (TMAO) and the degree of coronary atherosclerosis in coronary heart diseases (CHD) patients with type 2 diabetes mellitus. Methods: Consecutive patients, who underwent coronary angiography due to suspected CHD in Beijing Hospital from November 2016 to January 2018, were screened in this cross-sectional study. According to blood glucose level, previous medical history and coronary angiography results, they were divided into CHD without type2 diabetes mellitus(CHD-nDM) group and CHD with type2 diabetes mellitus(CHD-DM) group. Plasma TMAO levels in each group were measured by LC-MS/MS. Spearman correlation analysis was used to evaluate the correlation between TMAO and the number of diseased vessels and Gensini scores. Multivariate logistic regression was used to analyze the correlation between TMAO and high Gensini scores. Results: A total of 590 patients were enrolled in the study, including 238 patients in CHD-DM group and 352 patients in CHD-nDM group. Patients were older, body mass index, blood pressure level, prevalence of history of hypertension and statins use were higher in CHD-DM group than in CHD-nDM group (all P<0.05). The proportion of patients with multivessel disease (2 or more vessels) was also higher in CHD-DM group than in CHD-nDM group (P<0.001). Gensini score was higher in CHD-DM group than in CHD-nDM group (P<0.05). Fasting blood glucose, glycosylated hemoglobin and urea were significantly higher, while low-density lipoprotein cholesterol and hemoglobin were significantly lower in CHD-DM group than in CHD-nDM group (all P<0.05). The levels of TMAO was significantly higher in CHD-DM group than in CHD-nDM group (P<0.001). Spearman correlation analysis showed that TMAO was positively correlated with the number of diseased vessels, Gensini score, age and blood glucose level (r=0.178, 0.189, 0.260, 0.111, respectively, all P<0.01). Multivariate logistic regression analysis showed that, TMAO level was still positively correlated with high Gensini score in CHD-DM group (OR=2.25, 95%CI 1.16-4.38, P=0.017), but not in CHD-nDM group (OR=1.29, 95%CI 0.72-2.31, P=0.386) after adjusting for age, sex, body mass index, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, total cholesterol, triglyceride, history of hypertension, hyperlipidemia, smoking and statin use. Conclusions: In CHD patients with tupe 2 diabetes mellitus, the plasma TMAO level is significantly increased and is independent and positively correlated with the degree of coronary artery disease.

Establishment of a novel mouse mode of elastase-induced chronic obstructive pulmonary disease related osteoporosis / 中国骨伤

OBJECTIVE@#To establish and evaluate the model of chronic obstructive pulmonary disease (COPD) with osteoporosis induced by elastase in mice.@*METHODS@#Twenty four healthy female 8-week-old C57BL / 6 mice (weighing about 18 g) were randomly divided into three groups. The control group was given intratracheal drip of normal saline, the experimental group 1 and the experimental group 2 were given intratracheal drip of elastase, the control group and the experimental group 1 were kept for 8 weeks and then killed, the experimental group 2 was kept for 12 weeks and then killed. HE staining was used to evaluate the histopathological changes of lung and tibia in the control and experimental groups. The levels of serum inflammatory factors and broncho alveolar lavage factors (BALF) were detected by ELISA. Micro CT was used to detect the bone mass related parameters of mouse femur. The expression of osteoclastic and osteogenic genes was detected by real-time fluorescence quantitative PCR.@*RESULTS@#Lung histopathology showed that the structure of alveoli in the experimental group was disordered, the walls of alveoli became thin or broken, and the alveoli cavity expanded. IL-6 and TNF-α in BALF were significantly higher than those in control group (<0.001), while IL-1β and TNF-α in serum inflammatory factors were significantly higher than those in control group (<0.001). BV / TV(bone volume fraction), TB.Th(average bone trabecular thickness) and TB.N(average bone trabecular number) in the experimental group were significantly lower than those in the control group (<0.05), TB.Sp (average bone trabecular separation) and BS / BV (bone surface area fraction) in the experimental group were significantly higher than those in the control group (<0.01). Compared with the control group, the expression of osteoclast related marker genes increased in the experimental group (<0.05), but decreased in the experimental group(<0.05). The results of experiment 1 and experiment 2 were time-dependent.@*CONCLUSION@#In this study, elastase was used to construct a COPD model with osteoporosis successfully, which provides a suitable animal model for the future study of the pathogenesis of COPD with osteoporosis.

Relationship between fractional esterification rate of high density lipoprotein cholesterol and coronary artery disease / 中华心血管病杂志

<p><b>OBJECTIVE</b>To assess the relationship between fractional esterification rate of high density lipoprotein cholesterol (FER(HDL)) and coronary artery disease.</p><p><b>METHODS</b>A total of 131 hospitalized patients underwent coronary angiography due to chest pain were included in the study and patients were divided into CAD group (n = 76) and non CAD group (n = 55) according to coronary angiogram. Clinical and laboratory data including biochemical laboratory, FER(HDL) and lipid subclasses were analyzed.</p><p><b>RESULTS</b>The FER(HDL) value of CAD group was significantly higher than that of the non CAD group (21.70 ± 8.73 vs. 18.65 ± 6.26, P < 0.05). There was an increased trend of FER(HDL) with numbers of diseased coronary arteries, significant difference was evidenced between non CAD group and 3-vessel group (18.65 ± 6.26 vs. 24.00 ± 9.22, P < 0.05). FER(HDL) was positively correlated with TG (r = 0.647, P < 0.001), LDLb-C(r = 0.441, P < 0.001) and negatively correlated with HDL-C (r = -0.708, P < 0.001) and HDL(2)-C (r = -0.748, P < 0.001).</p><p><b>CONCLUSION</b>Our data showed that the values of FER(HDL) were significantly increased in CAD patients and correlated with the severity of the CAD.</p>

External quality assessment on detection of hepatitis C virus RNA in clinical laboratories of China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>As with many studies carried out in European countries, a quality assurance program has been established by the National Center for Clinical Laboratories in China (NCCL). The results showed that the external quality assessment significantly improves laboratory performance for quantitative evaluation of hepatitis C virus (HCV) RNA.</p><p><b>METHODS</b>Serum panels were delivered twice annually to the clinical laboratories which performed HCV RNA detection in China. Each panel made up of 5 coded samples. All laboratories were requested to carry out the detection within the required time period and report on testing results which contained qualitative and/or quantitative test findings, reagents used and relevant information about apparatus. All the positive samples were calibrated against the first International Standard for HCV RNA in a collaborative study and the range of comparison target value (TG) designated as +/- 0.5 log.</p><p><b>RESULTS</b>The numbers of laboratories reporting on qualitative testing results for the first and second time external quality assessment were 168 and 167 in the year of 2003 and increased to 209 and 233 in 2007; the numbers of laboratories reporting on quantitative testing results were 134 and 147 in 2003 and rose to 340 and 339 in 2007. Deviation between the mean value for quantitative results at home in 2003 and the target value was above 0.5 log, which was comparatively high. By 2007, the target value was close to the national average except for the low concentrated specimens (10(3) IU/ml). The percentage of results within the range of GM +/- 0.5 log(10) varied from 8.2% to 93.5%. Some laboratories had some difficulties in the exact quantification of the lowest (3.00 log IU/ml) as well as of the highest viral levels (6.37 log IU/ml) values, very near to the limits of the dynamic range of the assays.</p><p><b>CONCLUSIONS</b>The comparison of these results with the previous study confirms that a regular participation in external quality assessment (EQA) assures the achievement of a high proficiency level in the diagnosis of HCV infection. During the 5-year external quality assessment, sensitivity and accuracy of detection in most of the clinical laboratories have been evidently improved and the quality of kits has also been substantially improved.</p>

Establishment of the first national standards for nucleic acid amplification technology assay for HBV DNA / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To establish a Chinese national standard for a nucleic acid test (NAT) for HBV DNA.</p><p><b>METHODS</b>The candidate sample of HBV DNA positive plasma was diluted with HBV-negative human plasma. The sample was lyophilised with a concentration of approximately 300,000 copies/ml. The measurement methods used included Roche Amplicor assay (version 2.0) and real-time PCR. The lyophilised preparation was calibrated by the international standard (NIBSC code: 97/746) from NIBSC.</p><p><b>RESULTS</b>The quantity of this lyophilised preparation was (1.29+/-0.24) x 10(5)IU/ml in comparison with the international standard for HBV DNA 97/746. The stability test indicated that the sample was stable at room temperature (20 to 25 degrees C) for 2 weeks and at 37 degrees C for at least 1 week. Long-term stability was observed at 2 to 8 degrees C for 6 months and at -20 degrees C for more than 2 years with no significant changes. The vial-to-vial imprecision rate was 3.53%.</p><p><b>CONCLUSION</b>Based on the results of this study, our lyophilized sample can be used as a standard in China for the nucleic acid test (NAT) for HBV DNA.</p>

Lyophilized standards for the calibration of real time PCR assay for hepatitis C virus RNA / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Since October 1997, an international standard for hepatitis C virus (HCV) nucleic acid amplification technology assay, 96/790, has been available. We compared a series of lyophilized standards with known HCV RNA concentrations against the international standard in fluorescence quantitative PCR detection.</p><p><b>METHODS</b>A series of lyophilized sera were calibrated by ROCHE COBAS AMPLICOR HCV Monitor test against the international standard and sent to various manufacturers to analyse the samples using their own kits. Then calibration curves from the series were compared with that obtained from the external standard calibration curve with the manufacture's series.</p><p><b>RESULTS</b>The standard calibration curve with the series of lyophilized serum showed an excellent correlation (R(2) > 0.98), slope and intercept that were similar to those from the manufacture's series. When the standard calibration curve from the series of lyophilized standards were used to define the values of the given sample, lower coefficients of variation between kits from different manufactures were obtained.</p><p><b>CONCLUSION</b>The results showed that the lyophilized standards could be used to setup the standard calibration curve for clinical HCV RNA quantitative PCR detection.</p>

Reference methods and reference measurement principles in clinical biochemistry / 中华检验医学杂志

Characteristics and measurement principles of reference methods in clinical biochemistry were described.Implementation of reference systems is one of the most effective approaches to improve the accuracy and comparability of clinical laboratory test results.Reference methods are the key components of reference systems.Reference methods should have measurement uncertainties that meet the requirements of the intended use,and thus should be based on reliable measurement principles.For the well-defined biochemistry analytes,reference methods have been almost all based on instrumental analysis.Isotope dilution mass spectrometry (ID/MS) is considered most reliable and has been the major analytical principle of the reference methods.ID/MS analysis is accurate but expensive.Use of other validated instrumental analyses as reference measurement principles would be justified.

Determination of total cholesterol in serum by isotope dilution liquid chromatography tandem mass spectrometry / 中华检验医学杂志

Objective To develop a method for the determination of total cholesterol in serum by isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS).Methods Serum samples were supplemented by addition of [3,4-~(13)C_2]-cholesterol,hydrolyzed with alcoholic sodium hydroxide and oxidized into cholest-4-ene-3,6-dione by chromic acid.The oxidation products were analyzed by LC/MS/MS using atmospheric pressure chemical ionization (APCI) source and detection modes of multiple reaction monitoring (MRM) and single ion recording (SIR).Signals (peak areas) of the internal standard were corrected for the contributions of cholesterol and the signal ratios of cholesterol to internal standard for the calibrations were linearly regressed against cholesterol concentrations.The resulted regression equation was used for the calculation of serum cholesterol concentrations.Results The correlation coefficients between the peak area ratios and cholesterol concentrations were 0.999 9 and higher.Under MRM mode,the average within-run CV of the results obtained on 3 serum samples was 0.95% (ranged from 0.92% to 0.99%) and the total CVwas 0.86% (0.82% to 0.89%),and under SIR mode,the within-run CV was 0.64% (from 0.54% to 0.77%) and the total CVwas O.69% (0.62% to 0.81%),respectively. Results on certified reference materials (SRM 1951 a Level Ⅰ and Level Ⅱ;GBW 09145 and GBW 09147) showed an average bias of 0.23% (0.14% to 1.00%) under MRM mode,and 0.24% (0.07% to 1.27%) under SIR mode.Conclusions An ID-LC/MS/MS method for serum cholesterol has been developed.It is specific and precise and may be used as a candidate reference method.

Determination of serum progesterone by isotope dilution gas chromatography mass spectrometry / 中华检验医学杂志

Objective To develop a candidate reference method for the measurement of progesterone in human serum.Methods The serum sample is mixed with the internal standard [3,4-~(13)C_2] progesterone.After extraction with n-hexane and purified by a aqueous solution of 2-Hydroxypropyl-?- cyclodextrin (HP-?-CD),the serum progesterone and labeled progesterone are converted to the 3-enol heptafluorobutyrate and analyzed by gas chromatography mass spectrometry (GC/MS) with selected ion monitoring.The concentration of serum progesterone is calculated by bracketing method.Results The results gave coefficients of variation (CVs) of 0.69% to 2.12%.The analytical recoveries ranged from 98.3% to 100.1%.The results of measuring certified reference materials of serum progesterone are agree with the target value.Conclusion The procedure for measuring progesterone in serum is a highly accurate and precise method and may be used as a candidate reference method for serum progesterone assays.

Preparation of glycerol reference material / 中华检验医学杂志

Objective To prepare a glycerol reference material.Methods The material was prepared and characterized according to the primary standard substance technological specification(JJG 1006- 1994).Glycerol was dissolved in water containing 0.5% sodium azide and dispersed to glass ampules.The homogeneity and stability of this material were tested with an HPLC method.Glycerol concentration was determined by a titration method as specified in the Pharmacopoeia of China.Results The three time measuring result of glycerol reference material was 1.297 5?0.014 3,1.302 0?0.008 9,1.313 7? 0.007 8,respectively.Statistical analysis showed that this material was homogeneous (F=1.462,P=0.166) .It was stable for at least 4 years at 4℃.The assigned reference value was 0.103 6 g/g and the expanded uncertainty was 0.000 4 g/g.Conclusions This material meet the technical requirements of national primary standard reference material.It is approved as the Certified Reference Material (GBW 09149) by General Administration of Quality Supervision,Inspection,Quarantine of the People's Republic of China in May,2006.