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The aim of this study is to investigate the status of laboratory practice of organic acid (OA) analysis using gas chromatography–mass spectrometry in China.

This study aims to evaluate the commutability of external quality assessment (EQA) materials and candidate reference materials (RMs) for plasma renin activity (PRA) assay. Commutabilities of 16 candidate RMs were measured along with 40 clinical samples by the four different routine PRA assays, including three LC‒MS/MS assays and one chemiluminescence immunoassay. Sixteen candidate RMs included native/spiked human plasma pools (small-scale pools with <50 individuals) and current EQA materials (large-scale pools with >1,000 individuals). Difference in bias approach and linear regression with prediction interval approach were adopted to determine the commutability. Two-way variance analysis was used to estimate the effects of spiked and pool size on the commutability. Stability and homogeneity studies were performed. Precision and correlation performance of all assays was acceptable. In the difference in bias approach, the commutability results were not satisfactory (noncommutability: 14/16) and significant sample-specific effects were detected in assay pairs using different incubation buffers. For the prediction interval approach, no commutability was observed in the spiked small-scale pools; EQA materials (4/9) had more satisfactory commutability among all assays than the small-scale pools (2/7); RMs of large-scale pools tend to have better commutability no matter spiked or not. Commutable RMs were obtainable but challenging. Current EQA materials with relatively good commutability, stability, and homogeneity were appropriate RMs. Large-scale pools are tending to be commutable. Spiking in small-scale pools was not suggested to prepare RMs. MPs adopting a uniform incubation buffer would be preferable for further commutability research. [ABSTRACT FROM AUTHOR]

Importance: Knowing the scale of rare inborn errors is important for screening and resource allocation. Evidence on the prevalence of methylmalonic acidemia (MMA) among newborns and the clinical-suspected population from large-scale screening programs needs to be systematically synthesized., Objective: To estimate the worldwide prevalence of MMA for newborns and the clinical-suspected population and explore the differences in different regions, periods, and diagnostic technologies., Data Sources: MEDLINE, Embase, CRD, Cochrane Library, Scopus, CINAHL, and PROSPERO. Study Selection: All studies reporting the epidemiology characteristics of MMA were selected., Data Extraction and Synthesis: Characteristics of study, subjects, and epidemiology were extracted, random-effect models were used for meta-analyses., Main Outcome and Measure: Pooled prevalence of MMA., Results: This study included 111 studies. The pooled prevalence of MMA worldwide was 1.14 per 100,000 newborns (1516/190,229,777 newborns, 95% CI: 0.99-1.29) and 652.11 per 100,000 clinical-suspected patients (1360/4,805,665 clinical-suspected individuals, CI: 544.14-760.07). Asia and Africa got a higher pooled prevalence of MMA. The prevalence of MMA in newborns increased through the years, while that in the clinical-suspected population decreased. Collecting blood ≥ 72 h after birth had a higher pooled prevalence of MMA than collecting during 24 h-72 h after birth. The combining-use of MS/MS and GC/MS had a higher pooled prevalence than the single-use of MS/MS or GC/MS. Prevalence of cbl C, mut, cbl B, cbl A, isolated MMA, combined MMA and homocystinuria, vitamin B12-responsive MMA was synthesized., Conclusions and Relevance: Prevalence of MMA among newborns was extremely low, but considerably high in the clinical-suspected population, indicating the need for more efficient newborn screening strategies and closer monitoring of the high-risk population for the early signs of MMA. Asia and Africa should attach importance to the high prevalence of MMA. Further diagnostic tests were recommended for the combining-use vs single-use of MS/MS and GC/MS and for collecting blood after 72 h vs during 24-72 h after birth.

Calcium ion is an important cation influencing the binding of recalcitrant organic contaminants with activated sludge during wastewater treatment process, but there is still unknown about its role in amphoteric fluoroquinolones binding. Binding experiments show that Ca 2+ markedly inhibited binding of ciprofloxacin (CIP) onto sludge, causing 7-203 times of CIP release. Multi-spectroscopic examinations indicate that tryptophan-like and tyrosine-like proteins in extracellular polymeric substances (EPS) were dominant components for CIP binding by static quenching and forming CIP-proteins complexes. Addition of Ca 2+ into EPS and CIP binding systems induced increase of association constants (from 0.024-0.064 to 0.027-0.084 L/μmol) and binding constants (from 0.002-0.039 to 0.012-0.107) and decrease of binding sites number (from 0.893-2.007 to 0.721-1.386). Functional groups of EPS and secondary structure of proteins were remarkably changed upon reactions with CIP and Ca 2+ . Calcium ion interacted with EPS and CIP binding system in two distinct ways: Ca 2+ shielded CO in amide I in EPS for CIP binding, whereas strengthened binding between CIP and functional groups including CO in carboxyl groups in extra-microcolony polymers and OH in extra-cellular polymers by forming ternary complexes. Cation competition for CO in amide I is responsible for Ca 2+ induced CIP release from the sludge. Results suggest the highly potential release of CIP from high saline wastewater and cation-conditioned sludge which needs further monitoring and evaluation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: MicroRNAs (miRNAs) have been found to be involved in coronary artery disease (CAD) and corresponding disease severity. The aim of this study is to determine plasma levels of miR-144 in CAD and its association with the severity of this disease., Methods: Plasma levels of miR-144 in 60 CAD patients including stable angina pectoris (SAP) (n=29), unstable angina pectoris (UAP) or non-ST elevation myocardial infarction (MI) (NSTEMI) (n=17), or ST-elevation MI (STEMI) (n=14) and 20 non-CAD subjects were detected by real-time polymerase chain reaction (QRT-PCR). Associations of miR-144 expression with basic clinical characteristics and the severity of CAD were then analyzed., Results: The QRT-PCR results showed that plasma miR-144 levels were increased in CAD patients, and among CAD patients, higher SYNTAX scores and STEMI were significantly associated with higher miR-144 expression., Conclusions: Higher plasma levels of miR-144 were significantly associated with the presence as well as severity of CAD. As a potential biomarker for CAD, plasma miR-144 may be useful in predicting CAD and its severity., (© 2018 by the Association of Clinical Scientists, Inc.)