Background: Semen quality in humans may be influenced by exposure to endocrine-disrupting compounds.
Objectives: We analyzed associations between semen characteristics and serum xenoestrogen receptor (XER), xenoandrogen receptor (XAR), and aryl hydrocarbon receptor (AhR) transactivity. XER and XAR activity were measured in serum samples cleared for endogenous steroid hormones and AhR activity in raw lipophilic serum extracts free of proteins.
Results: All together, 319 men from Warsaw (Poland), Greenland, Kharkiv (Ukraine), and Sweden provided semen and blood samples. No strong and consistent associations between xenobiotic activity and semen quality measures were observed in the four populations. However, when the data were combined across populations sperm concentration increased 40% per unit increase in XER activity [95% confidence interval (CI), 1-79%] in the subgroup with XER activity below the reference level. Among subjects with XER activity above the reference level an increase of 14% (95% CI, 2-28%) was found. Furthermore, an increase of 10% motile sperm per unit increase in XER activity below reference level (95% CI, 0.2-20) was found. We are unable to exclude that the associations are chance findings.
Conclusion: Alteration of XER, XAR, or AhR transactivity within the range found in serum from the general European and Inuit population seems not to markedly deteriorate sperm cell concentration, motility, or morphology in adult men.
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http://dx.doi.org/10.1289/ehp.9352 | DOI Listing |
Ecosphere
November 2023
US EPA, Office of Research and Development, Center for Public Health and Environmental Assessment, Pacific Ecological Systems Division, Corvallis, Oregon, USA.
Stream macroinvertebrate assemblages are shaped by natural and human-related factors that operate through complex hierarchical pathways. Quantifying these relationships can provide additional insights into stream ecological assessment. We applied a structural equation modeling framework to evaluate hypothesized pathways by which watershed, riparian, and in-stream factors affect benthic macroinvertebrate condition in the Western Mountains (WMT) and Xeric (XER) ecoregions in the United States.
View Article and Find Full Text PDFA series of green-emitting Y SiO:Er phosphors ( = 1-7 mol%) have been successfully synthesized using a straightforward gel-combustion method facilitated by urea. X-ray diffraction analysis provided specific patterns for samples, confirming a consistent triclinic phase across erbium-doped structures compared to undoped structures. Studies using TEM and EDX were conducted to identify the surface-related characteristics and chemical composition of the synthesized nanophosphor, respectively.
View Article and Find Full Text PDFAntimicrob Agents Chemother
June 2024
Emerging Antibiotic Resistance, Medical and Molecular Microbiology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland.
Xeruborbactam is a newly developed β-lactamase inhibitor designed for metallo-β-lactamases (MBLs). This study assessed the relative inhibitory properties of this novel inhibitor in comparison with another MBL inhibitor, namely taniborbactam (TAN), against a wide range of acquired MBL produced either in or . As observed with taniborbactam, the combination of xeruborbactam (XER) with β-lactams, namely, ceftazidime, cefepime and meropenem, led to significantly decreased MIC values for a wide range of B1-type MBL-producing , including most recombinant strains producing NDM, VIM, IMP, GIM-1, and DIM-1 enzymes.
View Article and Find Full Text PDFAntimicrob Agents Chemother
November 2023
Qpex Biopharma , San Diego, California, USA.
Recently, several β-lactam (BL)/β-lactamase inhibitor (BLI) combinations have entered clinical testing or have been marketed for use, but limited direct comparative studies of their activity exist. Xeruborbactam (XER, also known as QPX7728), which is undergoing clinical development, is a cyclic boronate BLI with potent inhibitory activity against serine (serine β-lactamase) and metallo-β-lactamases (MBLs). The objectives of this study were (i) to compare the potency and spectrum of β-lactamase inhibition by various BLIs in biochemical assays using purified β-lactamases and in microbiological assays using the panel of laboratory strains expressing diverse serine and metallo-β-lactamases and (ii) to compare the potency of XER in combination with multiple β-lactam antibiotics to that of other BL/BLI combinations in head-to-head testing against recent isolates of carbapenem-resistant (CRE).
View Article and Find Full Text PDFmBio
December 2022
Department of Biochemistry, University of Torontogrid.17063.33, Toronto, Ontario, Canada.
In bacteria, the mechanisms used to repair DNA lesions during genome replication include homologous recombination between sister chromosomes. This can lead to the formation of chromosome dimers if an odd number of crossover events occurs. The dimers must be resolved before cell separation to ensure genomic stability and cell viability.
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