Commutability Assessment of Candidate External Quality Assessment Materials for Aminotransferase Activity Measurements Based on Different Approaches in China
ANNALS OF LABORATORY MEDICINE
Authors: Long, Qichen; Qi, Tianqi; Zhang, Tianjiao; Wang, Jing; Zeng, Jie; Yan, Ying; Wang, Meng; Huang, Wei; Zhao, Haijian; Chen, Wenxiang; Zhang, Chuanbao
Background: Using commutable external quality assessment (EQA) materials is important for monitoring successful harmonization efforts. We assessed the commutability of four human serum pool (HSP) preparations to identify candidate EQA materials for alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity measurement. Methods: One set each of 85 clinical samples (CSs) was collected for ALT and AST activity measurement. The 15 candidate EQA materials included four types of HSP preparations (A to D): materials A, C, and D contained human original recombinant (HOR) aminotransferases; materials B was mixed leftover samples. The CSs and 15 candidate EQA materials were analyzed using seven routine assays, and the In-transformed results were analyzed in 21 assay pairs. Commutability was assessed using Deming regression, with a 95% prediction interval (CLSI approach) and the difference in bias with an error component model (International Federation of Clinical Chemistry and Laboratory Medicine [IFCC] approach). Results: For ALT, all materials were commutable for 14-21 assay pairs according to the CLSI and IFCC approaches. For AST, B01-03 showed commutability for 14-21 assay pairs, and C01-03 and D01-03 showed commutability for no less than 10 assay pairs according to the two approaches. A01-06 were commutable for 9-16 assay pairs according to the CLSI approach, but for 6-9 assay pairs according to the IFCC approach. Conclusions: Mixed leftover samples showed desirable commutability characteristics as candidate EQA materials for routine aminotransferase activity measurements. Human serum bases supplemented with HOR were commutable for most routine ALT activity measurements.
Chronic exposure of BPA impairs male germ cell proliferation and induces lower sperm quality in male mice
Authors: Liu, XueXia; Wang, ZhiXin; Liu, Fujun
Background: Bisphenol A (BPA) is a well-known endocrine disruptor that affects male fertility. However, the main biological events through which BPA affects spermatogenesis remain to be identified. Methods: Adult male mice were treated by feeding with drinking water containing BPA (0.2 mu g/ml, 20 mu g/ml, 200 mu g/ml, respectively) for two months. Testes were collected for protein extraction or for immunohistochemical analysis. Epididymal spermatozoa were collected for sperm quality evaluation and male fertility assay by in vitro fertility (IVF). Serums were collected for detection of testosterone levels. Proteins associated with germ cell proliferation, meiosis, blood-testis barrier, and steroidogenesis production were examined in BPA-treated and control mice testes. CCK8 assay was used to detect the effect of BPA on the proliferation of GC-1 and GC-2 cells. Results: The BPA-treated mice were characterized by decreased sperm quality, serum testosterone levels and, sub-fertile phenotype characterizing with low pregnancy rates and reduced fertilization efficiency. In lower BPA (0.2 mu g/ml) treatment, PCNA and PLZF were down-expressed that indicated impaired germ cell proliferation. SYCP3 was down-expressed in BPA-treated mice, but expressions of other proteins associated with meiosis and blood-testis barrier were not significantly altered. CYP11A1 and HSD3B1 were down-expressed in BPA-treated mice that demonstrated reduced steroidogenesis activity. BPA has a concentration-dependent inhibition effect on the proliferation of GC-1 and GC-2 cells. Conclusively, low doses BPA exposure reduced mice sperm quality mainly by impairing germ cell proliferation, leading to reduced male fertility. The study would provide relevant information for investigation on molecular mechanisms and protective strategy on male production. (C) 2020 Elsevier Ltd. All rights reserved.