Maternal hair segments reveal metal(loid) levels over the course of pregnancy: a preliminary study in Southern China.

Characterization of metal(loid) variation during pregnancy and identification of the affecting factors are important for assessing pregnancy exposures in epidemiological studies. In this study, maternal hair was collected in three segments (each 3 cm) from pregnant women in Guangzhou, China. Ten metal(loid)s, including six essential trace metal(loid)s and four toxic trace metal(loid)s, were analyzed to investigate the levels of various metal(loid)s during pregnancy and the factors that influence them. Strong pairwise correlations were observed between manganese (Mn), cobalt (Co), and vanadium (V), between selenium (Se), arsenic (As), and antimony (Sb), and between cadmium (Cd) and lead (Pb). All metal(loid)s except for Se, Mn, and Co showed strong correlations among the three hair segments, and most of the metal(loid)s had good reproducibility, with intraclass correlation coefficients (ICCs) ranging from 0.510 to 0.931, except for As (ICC = 0.334), Mn (ICC = 0.231), and Co (ICC = 0.235). Zn levels decreased, while Sb increased, in maternal hair during pregnancy. Maternal sociodemographic characteristics and dietary intake affected metal(loid) levels in maternal hair. These results provide foundational data for using maternal hair segmental analysis to evaluate exposure variation to metal(loid)s during pregnancy and the potential factors associated with them.

Spatial distribution, impact factors, and potential health implications of trace elements in human hair from capital residents in China.

We analyzed the levels, spatial distribution, impact factors, source apportionment, and potential health implications of trace elements (V, Zn, Cu, Mn, Ni, Mo, and Co) in 1202 human hair samples of urban residents aged 4-55 from 29 cities in China. The median values of seven trace elements in hair were found in the following increasing order: Co (0.02 µg/g) < V (0.04 µg/g) < Mo (0.05 µg/g) < Ni (0.32 µg/g) < Mn (0.74 µg/g) < Cu (9.63 µg/g) < Zn (157 µg/g). The spatial distribution of these trace elements in the hair from the six geographical subdivisions varied depending on the exposure sources and impact factors. Principal component analysis (PCA) revealed that Cu, Zn, and Co in the hair samples of urban residents were primarily derived from food, whereas V, Ni, and Mn were attributed to industrial activities and food. Majority of the hair samples (up to 81%) from North China (NC) exceeded the recommended value for V content, whereas up to 59.2%, 51.3%, and 31.6% samples from Northeast China (NE) exceeded the recommended values for Co, Mn, and Ni contents, respectively. The levels of Mn, Co, Ni, Cu, and Zn were significantly higher in female hair than those in male hair, whereas the levels of Mo were higher in male than in female hair (p < 0.01). Furthermore, significantly higher Cu/Zn ratios were observed in the hair of male residents than those in the female residents (p < 0.001), indicating a higher health risk for male residents.

Butyrate prevents the migration and invasion, and aerobic glycolysis in gastric cancer via inhibiting Wnt/ß-catenin/c-Myc signaling.

Gastric cancer (GC) remains a common cause of cancer death worldwide. Evidence has found that butyrate exhibited antitumor effects on GC cells. However, the mechanism by which butyrate regulate GC cell proliferation, migration, invasion, and aerobic glycolysis remains largely unknown. The proliferation, migration, and invasion of GC cells were tested by EdU staining, transwell assays. Additionally, protein expressions were determined by western blot assay. Next, glucose uptake, lactate production, and cellular ATP levels in GC cells were detected. Furthermore, the antitumor effects of butyrate in tumor-bearing nude mice were evaluated. We found, butyrate significantly prevented GC cell proliferation, migration, and invasion (p < .01). Additionally, butyrate markedly inhibited GC cell aerobic glycolysis, as shown by the reduced expressions of GLUT1, HK2, and LDHA (p < .01). Moreover, butyrate notably decreased nuclear ß-catenin and c-Myc levels in GC cells (p < .01). Remarkably, through activating Wnt/ß-catenin signaling with LiCl, the inhibitory effects of butyrate on the growth and aerobic glycolysis of GC cells were diminished (p < .01). Moreover, butyrate notably suppressed tumor volume and weight in GC cell xenograft nude mice in vivo (p < .01). Meanwhile, butyrate obviously reduced nuclear ß-catenin, c-Myc, GLUT1, HK2 and LDHA levels in tumor tissues in GC cell xenograft mice (p < .01). Collectively, butyrate could suppress the growth and aerobic glycolysis of GC cells in vitro and in vivo via downregulating wnt/ß-catenin/c-Myc signaling. These findings are likely to prove useful in better understanding the role of butyrate in GC.

The accumulation of organic contaminants in hair with different biological characteristics.

Human hair has increasingly been used as a noninvasive biomonitoring matrix for assessment of human exposure to various organic contaminants (OCs). However, the accumulation processes of OCs in hair remains unclear thus far, which raised concerns on the reliability of hair analysis results for OCs. Herein, Chinese population was selected as the study subject, the effects of changes in hair biological characteristics, including length and color, on the accumulation of OCs in hair was investigated. With the growing of hair shaft and the increased distance from the scalp, a significant increasing trend was found for levels of polychlorinated biphenyls (PCBs) and organophosphate flame retardants (PFRs) along the hair shafts (p < 0.05). Source identification using Chemical Mass Balance model indicated that PCBs in hair were mainly from exogenous sources (air and dust). The accumulation rates of PCB and PFR individuals in the hair shaft decreased with increasing of log Kow values. Additionally, the levels of OCs in hair decreased with the change in color from black to white, probably because of the loss of melanin in white hair. The ratios (R) of Cblack/Cwhite were significantly correlated with the log Kow values for individual chemicals (p < 0.05), implying that OCs with high log Kow values tend to accumulate more readily in black hair. The results of this study demonstrated the growth and change in colors of hair, as well as the physicochemical properties of chemicals, play vital roles in the accumulation of OCs in hair. The present study provides fundamental basis for the precise assessment of human exposure to OCs using hair as a biomonitoring matrix in future studies.