Development and validation of an LC-MS/MS method for the determination of 12 ceramides in human plasma / 中华检验医学杂志

Objective:To establish and validate a reliable and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the detection of 12 ceramides in human plasma.Methods:From October 2021 to October 2022, 438 apparently healthy individuals were enrolled in the Affiliated Hospitals of Zunyi Medical University for reference intervals of 12 ceramides in this population. Plasma samples were collected, and separated using the ACQUITY UPLC BEH C18 (2.1×50 mm, 1.7 μm) column, deuterated isotopes were used as internal standards. The mobile phase is water (containing 0.1% formic acid) and isopropanol: acetonitrile (1∶1, v/v, containing 0.1% formic acid) at a flow rate of 0.4 ml/min with gradient elution. The detection method was established using the Qlife Lab 9000 Plus triple quadrupole mass spectrometer. The performance of the method was evaluated in terms of linearity, the lower limit of quantification, precision, recovery, and stability.Results:The method passed the performance evaluation in terms of linearity, the lower limit of quantification, recovery, precision, and stability. The intra-and inter-batch precision of the 12 ceramides ranged from 1.3% to 14.3%, the correctness was verified by spiked recovery experiments, and the recoveries ranged from 91.9% to 111.0%. The lower limit of quantification ranged from 0.001 to 0.100 μmol/L. Standard curve showed good linearity (correlation coefficient r>0.990). Stability tests showed that the 12 ceramides were stable in the biological matrix and after processing under different conditions for a specified period of time. The corresponding biological reference intervals were established for each of the 12 ceramides: 0.103-0.326 μmol/L for Cer(d18∶1/16∶0), 0.018-0.098 μmol/L for Cer(d18∶1/18∶0), 0.933-3.919 μmol/L for Cer(d18∶1/24∶0), 0.243-1.072 μmol/L for Cer(d18∶1/24∶1), 0.001-0.007 μmol/L for Cer(d18∶1/14∶0), 0.022-0.095 μmol/L for Cer(d18∶1/20∶0), 0.185-0.835 μmol/L for Cer(d18∶1/22∶0), 0.003-0.022 μmol/L for Cer(d18∶0/16∶0), 0.001-0.016 μmol/L for Cer(d18∶0/18∶0), 0.017-0.156 μmol/L for Cer(d18∶0/24∶0), 0.008-0.074 μmol/L for Cer(d18∶0/24∶1), and 0.106-0.721 μmol/L for LacCer(d18∶1/24∶1). Conclusion:Our study shows that the newly established LC-MS/MS method for the determination of 12 ceramides in human plasma is reliable, and suitable for clinical application.

Importance of clinical lipid profile testing and lipid management: a new viewpoint to the prevention and treatment of ASCVD based on the new guidelines / 中华检验医学杂志

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death of urban and rural residents in China, and dyslipidemia is the most important pathogenic risk factor for the occurrence and development of ASCVD. Faced with the increasing ASCVD burden in China, there is an urgent need to improve the lipid management in China. Clinical blood lipid testing is an important component of lipid management, and the accurate test results are a fundamental requirement for effective lipid management. The "China guidelines for clinical lipid profile testing" and "China guidelines for lipid management (2023)" are newly published. With the continuous updating of concepts on clinical lipid profile testing and lipid management, it is essential to further strengthen the communication and cooperation between clinical medicine and laboratory medicine, widely promote and apply the new concepts of updated guidelines, in order to better guide clinical practice, comprehensively improve the level of clinical lipid profile testing and lipid management in China, and assist in the standardized prevention and treatment of ASCVD in China and the early arrival of the turning points.

Attention should be given to the research and development of laboratory medicine in the field of cardiovascular metabolism / 中华检验医学杂志

Cardiometabolic disease mainly refers to the cardiovascular disease caused by the increased metabolic burden, including hypertension, diabetes, dyslipidemia, coronary heart disease, stroke, and so on. In China, the incidence of this kind of disease is continuous rising, and cardiometabolic disease is more and more diagnosed in patients in younger age. Currently, continuous exploration of new biomarkers and detection methods, standardization of testing techniques, strengthening of clinical and laboratory communication and cooperation, and cultivation of interdisciplinary talents are the major focuses in term of promoting the development of laboratory medicine in the field of cardiovascular metabolism.

Research progress of phytosterolemia and its laboratory diagnosis / 中华检验医学杂志

Phytosterolemia is a rare, severe autosomal recessive sterol storage disorder caused by homozygous or compound heterozygous mutations in one of the ABCG5 and/or ABCG8 adenosine triphosphate binding cassette (ABC) genes. The most prominent features of phytosterolemia are the significantly increased serum content of plant sterols. Present review focused on the laboratory diagnosis of phytosterolemia, briefly described the metabolism of phytosterols, and introduced the latest research progress on phytosterolemia diagnosis, its relationship with ASCVD and laboratory diagnostic methods (including the detection of serum concentrations of phytosterols, ABCG5/G8 gene mutation). We hope this article could improve readers′ awareness and attention on this disease.

Effects of blood-lipid report's reformat on outpatients' behavior and knowledge of dyslipidemia therapy / 中华全科医师杂志

Objective To evaluate the effects of blood-lipid report's reformat on outpatients' behavior and knowledge of dyslipidemia therapy.Methods The blood-lipid report was reformatted by adding three tables from the Chinese Guideline on the Prevention and Treatment of Adult Dyslipidemia on its back.The same questionnaire was used twice to evaluate the patients' behavior and knowledge of dyslipidemia therapy before and after reformat.Results Before and after reformat,the rates of correct deterination of their own risk stratification were 26.0％ ( 112/430 ) and 26.3％ ( 115/438 ) respectively.The awareness rates of Different LDL-C goals among different persons wcre 37.0％ (159/430) and 35.8％ (157/438).Only 0.7％ (2/306) and 1.0％ (3/299) of patients knew their blood lipid goals (P =0.557).When the report showed normal blood lipid levels,the percentages of taking lipid-lowering drug were 47.6％ ( 230/483 ) and 46.6％ ( 216/464 ),20.5％ ( 99/483 ) and 19.0％ ( 88/464 ) of patients questioned the prescription.Non-medication rates were 31.9％ ( 154/483 ) and 34.5％ ( 160/464 ) respectively before and after reformat ( P ＞ 0.05 ).For patients requiting lipid-lowering drug therapy by the guideline,treatment rate improved significantly in the low-risk group (13.3％ vs.75.0％,P =0.002).Treatment rate slightly increased in the high-risk and very high-risk groups after reformat (54.0％ vs.56.8％,62.4％ vs.69.0％,P ＞ 0.05 ).Rates of achieving lipid goal showed no change [ 41.5％ ( 102/ 245 ) vs.44.5％ ( 114/256 ),P ＞ 0.05 ] after reformat,especially among the very high-risk patients [17.9％(12/68) vs.21.6％(11/52),P＞0.05].Conclusions The blood-lipid report reformat did not improve the patient behaviors and knowledge of the prevention and treatment of dyslipidemia because of poor treatment rate and medication compliance.The combination of patient education and thorough blood-lipid report reformat may help to increase the attainment rate of dyslipidemia therapy.

Establishment of multiplex PCR for the rapid identification and toxin detection of Clostridium difficile strains / 中华微生物学和免疫学杂志

Objective To design a multiplex PCR for simultaneous identification and toxigenic type characterization of Clostridium difficile isolates. MethodsThree pairs of primers were designed for the amplification of a species-specific internal fragment of the tpi( triose phosphate isomerase) gene, an internal fragment of the tcdB ( toxin B) gene, and an internal fragment of the tcdA ( toxin A) gene. Twenty-one standard strains including Clostridium difficile ATCC 9689 and 47 isolates of Clostridium difficile were applied for the assessment of detection limit, specificity and detections of the multiplex PCR, respectively. Toxin A and Toxin B of 47 isolates were analyzed by ELISA. ResultsThe detection limit for DNA concentration of the multiplex PCR was 0.5 pg/μl. The specificity was determined to be 100％. Among the results of 47 isolates detected by multiplex PC R, 37 strains were tpi ( + )/tcdA (+)/tcdB ( + ), 10 strains were tpi ( + )/tcdA (-)/tcdB ( - ). Tpi ( + )/tcdA ( - )/tcdB ( + ) was not found. The toxin detection of 47 isolates by ELISA showed that 20 isolates were positive and 27 isolates were negative. Twenty isolates of toxin (+) by ELISA were all tpi( +)/tcdA( +)/tcdB(+) by multiplex PCR. ConclusionThe multiplex PCR method combined diagnosis and toxigenic type characterization contributes to the diagnosis for Clostridium difficile infection.

Primary study on the gene typing, molecular characteristics of virulence and resistance associated gene of 12 Clostridium difficile clinical isolates in China / 中国人兽共患病学报

To investigate the gene typing, molecular characteristics of virulence and resistance associated gene of Clostridium difficile from clinical isolates in China, the genes tcdA,tcdB of toxin A and B, cdtA,cdt B of binary-toxin, and erm B of clindamycin resistance were detected by conventional PCR. Genotyping of toxic C. difficile were conducted by means of analysis of 16s-23s internal spacer region polymorphism with PCR assay. Then the antibiotic resistance of toxic C. difficile to ampiciline, clindamycin, metronidazole and vancomycin was conducted with E-test. It was found that 8 toxic C. difficile strains were demonstrated out of 12 clinical isolates, in which 5 strains were tcdA+ and tcdB+, and 3 strains tcdA- and tcdB+, accounting for 62.5% and 37.5% respectively. Binary-toxin genes detection were negative in all the strains. Clindamycin resistance associated gene ermB was positive in 4 out of 8 toxic C. difficile strains, accounting for 50%. 8 toxic isolates were typed into 4 gene types, the dominant type was ZR I,accounting for 62.5%. Resistance rate of 8 toxic C. difficile strains against ampiciline(AC), clindamycin(CM), metronidazole(MZ) and vancomycin(VA) was 37.5%,87.5%,12.5%, and 0 respectively. No isolates belonged to ribotype 027 or 078. Isolation rate of toxic C. difficile is high to 66.7%. There is obvious gene polymorphism in clinical isolates of Chinese toxic C.difficite, and ZR I is preponderant genotype in 4 genotypes. C. difficile shows some resistance to ampiciline, clindamycin, metronidazole, but susceptive to vancomycin.

Research on Clostridium Difficile Infection in Clinic Patients Feces Specimen / 中华医院感染学杂志

OBJECTIVE This study was to investigate the carrier and infection of Clostridium difficile in clinic feces specimen,to analyze clinic characteristics,and to improve isolation rate and to provide basis on efficient prevention.METHODS C.difficile toxin A&B kit and anaerobic culture was conducted in 20 cases with diarrhea.Colonies suspected to be C.difficile,on the basis of their macroscopic appearance and characteristic odor,oxygen tolerance experiment,were confirmed by their biochemical characteristics(API 20A,bioMerieux).RESULTS After C.difficile selective culture,8 suspected colonies from 20 feces specimen were conducted by feces smear and oxygen tolerance experiment.6 of 8 was G+ rod bacteria with positive oxygen tolerance experiment.4 stains of C.difficile were identified by API 20A,positive rate was 20%;toxin detect was positive in 1 specimen(5%).CONCLUSIONS Infection of C.difficile Is associated with the basic disease.Watery feces specimen was prone to culture positive.

Circulating adiponectin,leptin and free fatty acids levels in relation to metabolism and inflammatory markers in type 2 diabetic subjects / 基础医学与临床

Objective To characterize the association of adiponectin,leptin and free fatty acids(FFA)with adiposity,insulin resistance,lipid profiles and inflammatory markers in type 2 diabetes.Methods We measured fasting serum adiponectin,leptin,FFA,high-sensitive C reactive protein(hs-CRP) levels and metabolic parameters in 77 cases of type 2 diabetic patients with or without obesity and 26 healthy subjects.Results Following parameters were significantly higher in type 2 diabetic patients than in healthy subjects: fasting serum leptin(?g/L)(4.5?3.9 vs 4.1?2.1),hsCRP(mg/L)(0.69?1.07 vs 0.33?0.47),FFA(?mol/L)(566?227 vs 391?129) and triglyceride(mmol/L)(1.61?1.02 vs 1.01?0.40);however,following parameters were significantly lower in type 2 diabetic patients than in healthy subjects: serum adiponectin(mg/L)(5.5?3.4 vs 9.1?4.1),highdensity lipoprotein cholesterol(HDL-C)(mmol/L)(1.22?0.27 vs 1.48?0.26), apolipoprotein AI(mmol/L)(1.35?0.19 vs 1.49?0.18) and apolipoprotein AII(mmol/L)(0.29?0.07 vs 0.34?0.06) concentrations(P

Constructing the framework for on-the-job training of qualified laboratory medicine personnel / 中华医院管理杂志

On-the-job training of qualified personnel is an important way of cultivating talented people. In light of the tasks and development orientation of the laboratory department, the paper deals with on-the-job training of personnel on different posts and at various levels according to their natural abilities and in line with local conditions. The methods include：①making efforts to enhance the knowledge and cultural level of laboratory personnel at various levels so as to guarantee the accuracy of laboratory results;②reinforcing the study and practice of clinical medical knowledge so as to strengthen the overall abilities to make laboratory diagnoses; ③cultivating a seine of research and innovations in research practice so as to establish the academic status of the laboratory department. The purpose of the above methods is to meet the needs of the development of laboratory medicine and to ensure the rational use of human resources. [

Methylenetetrahydrofolate reductase gene polymorphism and deep-vein thrombosis / 中华检验医学杂志

0 05) The plasma Hcy level was significantly higher in DVT group than in control group [(12 2?8 7) ?mol/L vs (10 4?4 8) ?mol/L, P

Relationship of cholesterol ester transfer protein TaqIB gene polymorphism with type 2 diabetes mellitus in Chinese Han nationality patients / 临床检验杂志

Objective To explore the relationship between plasma cholesterol ester transfer protein(CETP) and TaqIB gene polymorphism and type 2 diabetes mellitus(DM).Methods The genotypes of the first intron of CETP TaqIB gene in 102 patients with type 2 DM and 103 healthy controls were analyzed by polymerase chain reaction-restricted fragment length polymorphism(PCR-RFLP),and plasma CETP were measured by enzyme-linked immunosorbent assay(ELISA).The association of gene polymorphism with plasma lipids,lipoproteins and apolipoproteins was also analyzed.Results No significant differences in both of the alleles frequencies and genotypes in type 2 DM were noted in comparison with controls.There were no relationships between CETP TaqIB gene polymorphism and gender,family history,smoking and body mass index(BMI).No significant differences of plasma lipid levels were observed in healthy controls with different genotypes.However,significant differences in level of HDL-C or apoAI among different CETP TaqIB genotype groups were observed,and significant correlation between low high-density lipoproteinemia and B1 allele in type 2 DM was observed.Conclusion CETP TaqIB gene polymorphisms associated with lipid metabolism,which may be an important genetic factor for abnormal lipid metabolism in type 2 DM.