Publications by authors named "H HARRIS"

1,729 Publications

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The biochemical fate of Ag ions in Staphylococcus aureus, Escherichia coli, and biological media.

J Inorg Biochem 2021 Sep 3;225:111598. Epub 2021 Sep 3.

Department of Chemistry, The University of Adelaide, South Australia 5005, Australia,. Electronic address:

Silver is commonly included in a range of household and medical items to provide bactericidal action. Despite this, the chemical fate of the metal in both mammalian and bacterial systems remains poorly understood. Here, we applied a metallomics approach using X-ray absorption spectroscopy (XAS) and size-exclusion chromatography hyphenated with inductively coupled plasma mass spectrometry (SEC-ICP-MS) to advance our understanding of the biochemical fate of silver ions in bacterial culture and cells, and the chemistry associated with these interactions. When silver ions were added to lysogeny broth, silver was exclusively associated with moderately-sized species (~30 kDa) and bound by thiolate ligands. In two representative bacterial pathogens cultured in lysogeny broth including sub-lethal concentrations of ionic silver, silver was found in cells to be predominantly coordinated by thiolate species. The silver biomacromolecule-binding profile in Staphylococcus aureus and Escherichia coli was complex, with silver bound by a range of species spanning from 20 kDa to >1220 kDa. In bacterial cells, silver was nonuniformly colocalised with copper-bound proteins, suggesting that cellular copper processing may, in part, confuse silver for nutrient copper. Notably, in the treated cells, silver was not detected bound to low molecular weight compounds such as glutathione or bacillithiol.
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http://dx.doi.org/10.1016/j.jinorgbio.2021.111598DOI Listing
September 2021

Constraints on Lightly Ionizing Particles from CDMSlite.

Phys Rev Lett 2021 Aug;127(8):081802

Département de Physique, Université de Montréal, Montréal, Quebec H3C 3J7, Canada.

The Cryogenic Dark Matter Search low ionization threshold experiment (CDMSlite) achieved efficient detection of very small recoil energies in its germanium target, resulting in sensitivity to lightly ionizing particles (LIPs) in a previously unexplored region of charge, mass, and velocity parameter space. We report first direct-detection limits calculated using the optimum interval method on the vertical intensity of cosmogenically produced LIPs with an electric charge smaller than e/(3×10^{5}), as well as the strongest limits for charge ≤e/160, with a minimum vertical intensity of 1.36×10^{-7}  cm^{-2} s^{-1} sr^{-1} at charge e/160. These results apply over a wide range of LIP masses (5  MeV/c^{2} to 100  TeV/c^{2}) and cover a wide range of βγ values (0.1-10^{6}), thus excluding nonrelativistic LIPs with βγ as small as 0.1 for the first time.
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http://dx.doi.org/10.1103/PhysRevLett.127.081802DOI Listing
August 2021

Layilin Anchors Regulatory T Cells in Skin.

J Immunol 2021 Oct 1;207(7):1763-1775. Epub 2021 Sep 1.

Department of Dermatology, University of California San Francisco, San Francisco, CA;

Regulatory T cells (Tregs) reside in nonlymphoid tissues where they carry out unique functions. The molecular mechanisms responsible for Treg accumulation and maintenance in these tissues are relatively unknown. Using an unbiased discovery approach, we identified (layilin), a C-type lectin-like receptor, to be preferentially and highly expressed on a subset of activated Tregs in healthy and diseased human skin. Expression of layilin on Tregs was induced by TCR-mediated activation in the presence of IL-2 or TGF-β. Mice with a conditional deletion of layilin in Tregs had reduced accumulation of these cells in tumors. However, these animals somewhat paradoxically had enhanced immune regulation in the tumor microenvironment, resulting in increased tumor growth. Mechanistically, layilin expression on Tregs had a minimal effect on their activation and suppressive capacity in vitro. However, expression of this molecule resulted in a cumulative anchoring effect on Treg dynamic motility in vivo. Taken together, our results suggest a model whereby layilin facilitates Treg adhesion in skin and, in doing so, limits their suppressive capacity. These findings uncover a unique mechanism whereby reduced Treg motility acts to limit immune regulation in nonlymphoid organs and may help guide strategies to exploit this phenomenon for therapeutic benefit.
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http://dx.doi.org/10.4049/jimmunol.2000970DOI Listing
October 2021

Identification of canine circulating miRNAs as tumor biospecific markers using Next-Generation Sequencing and Q-RT-PCR.

Biochem Biophys Rep 2021 Dec 19;28:101106. Epub 2021 Aug 19.

Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, USA.

Delay in cancer diagnosis often results in metastasis and an inability to successfully treat the tumor. The use of broadly cancer-specific biomarkers at an early stage may improve cancer treatment and staging. This study has explored circulatory exosomal miRNAs as potential diagnostic biomarkers to identify cancer patients. Secretory exosomal miRNAs were isolated from 13 canine cancer cell lines (lymphoma, mast cell tumor, histiocytic cell line, osteosarcoma, melanoma, and breast tumor) and were sequenced by Next-Generation sequencing (NGS). We have identified 6 miRNAs (cfa-miR-9, -1841, -1306, -345, -132, and -26b) by NGS that were elevated in all cancer cell types. The miRNAs identified by NGS were then examined by Q-RT-PCR. The PCR data demonstrated similar expression patterns to those seen with NGS but provided fold differences that were much lower than those seen for NGS. Cfa-miR-9 was found to be the most consistently elevated miRNA in NGS and PCR, making it the most likely miRNA to prove diagnostic. In this study, we have demonstrated that it is possible to identify exosomal miRNAs with elevated secretion across multiple tumor types that could be used as circulatory diagnostic biomarkers for liquid biopsy in the future.
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http://dx.doi.org/10.1016/j.bbrep.2021.101106DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8379617PMC
December 2021

Light Dark Matter Search with a High-Resolution Athermal Phonon Detector Operated above Ground.

Phys Rev Lett 2021 Aug;127(6):061801

School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.

We present limits on spin-independent dark matter-nucleon interactions using a 10.6 g Si athermal phonon detector with a baseline energy resolution of σ_{E}=3.86±0.04(stat)_{-0.00}^{+0.19}(syst)  eV. This exclusion analysis sets the most stringent dark matter-nucleon scattering cross-section limits achieved by a cryogenic detector for dark matter particle masses from 93 to 140  MeV/c^{2}, with a raw exposure of 9.9 g d acquired at an above-ground facility. This work illustrates the scientific potential of detectors with athermal phonon sensors with eV-scale energy resolution for future dark matter searches.
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http://dx.doi.org/10.1103/PhysRevLett.127.061801DOI Listing
August 2021
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