Nuclear microprobe – synchrotron synergy: Towards integrated quantitative real-time elemental imaging using PIXE and SXRF

Ryan, C.G.; Etschmann, Barbara; Vogt, Stefan; Mäser, J.; Harland, C. L.; Achterbergh, E. van; Legnini, D.

doi:10.1016/j.nimb.2005.01.054

Cited by 142 publications

(97 citation statements)

References 11 publications

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“…Deconvolution of the X-ray fluorescence spectra was performed using GeoPIXE v6.3 (ref. 69; CSIRO, Australia) and calibrated using the metal foil measurements. Images were analysed using ImageJ and the relative calcium content quantified by measuring the pixel intensities from lines of interest (n ¼ 10) extending from the endosteum towards the central vein.…”

Section: Methodsmentioning

confidence: 99%

Therapeutic targeting and rapid mobilization of endosteal HSC using a small molecule integrin antagonist

Cao

Zhang

Grassinger

et al. 2016

Experimental Hematology

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The inherent disadvantages of using granulocyte colony-stimulating factor (G-CSF) for hematopoietic stem cell (HSC) mobilization have driven efforts to identify alternate strategies based on single doses of small molecules. Here, we show targeting a 9 b 1 /a 4 b 1 integrins with a single dose of a small molecule antagonist (BOP (N-(benzenesulfonyl)-L-prolyl-L-O-(1-pyrrolidinylcarbonyl)tyrosine)) rapidly mobilizes long-term multi-lineage reconstituting HSC. Synergistic engraftment augmentation is observed when BOP is co-administered with AMD3100. Impressively, HSC in equal volumes of peripheral blood (PB) mobilized with this combination effectively out-competes PB mobilized with G-CSF. The enhanced mobilization observed using BOP and AMD3100 is recapitulated in a humanized NODSCIDIL2Rg À / À model, demonstrated by a significant increase in PB CD34 þ cells. Using a related fluorescent analogue of BOP (R-BC154), we show that this class of antagonists preferentially bind human and mouse HSC and progenitors via endogenously primed/activated a 9 b 1 /a 4 b 1 within the endosteal niche. These results support using dual a 9 b 1 /a 4 b 1 inhibitors as effective, rapid and transient mobilization agents with promising clinical applications.

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Section: Methodsmentioning

confidence: 99%

Therapeutic targeting and rapid mobilization of endosteal HSC using a small molecule integrin antagonist

Cao

Zhang

Grassinger

et al. 2016

Experimental Hematology

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“…Thus, the total scan time (four roots, two replicates per treatment) was approximately 4 h. The XRF spectra were analyzed using GeoPIXE (Ryan et al, 1990(Ryan et al, , 2005 and images generated using the Dynamic Analysis method (Ryan and Jamieson, 1993;Ryan, 2000;Ryan et al, 2010). All scans were conducted at ambient conditions.…”

Section: Synchrotron Analysis (M-xrf)mentioning

confidence: 99%

In Situ Speciation and Distribution of Toxic Selenium in Hydrated Roots of Cowpea

et al. 2013

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The speciation and spatial distribution of selenium (Se) in hydrated plant tissues is not well understood. Using synchrotronbased x-ray absorption spectroscopy and x-ray fluorescence microscopy (two-dimensional scanning [and associated mathematical model] and computed tomography), the speciation and distribution of toxic Se were examined within hydrated roots of cowpea (Vigna unguiculata) exposed to either 20 mM selenite or selenate. Based upon bulk solution concentrations, selenate was 9-fold more toxic to the roots than selenite, most likely due to increased accumulation of organoselenium (e.g. selenomethionine) in selenate-treated roots. Specifically, uptake of selenate (probably by sulfate transporters) occurred at a much higher rate than for selenite (apparently by both passive diffusion and phosphate transporters), with bulk root tissue Se concentrations approximately 18-fold higher in the selenate treatment. Although the proportion of Se converted to organic forms was higher for selenite (100%) than for selenate (26%), the absolute concentration of organoselenium was actually approximately 5-fold higher for selenate-treated roots. In addition, the longitudinal and radial distribution of Se in roots differed markedly: the highest tissue concentrations were in the endodermis and cortex approximately 4 mm or more behind the apex when exposed to selenate but in the meristem (approximately 1 mm from the apex) when exposed to selenite. The examination of the distribution and speciation of Se in hydrated roots provides valuable data in understanding Se uptake, transport, and toxicity.

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“…The DA technique is a matrix-transform algorithm that unfolds overlaps and subtracts background, escape peaks and other detector artifacts. GeoPIXE II has been extended for use with energy-dispersion synchrotron X-ray fl uorescence (SXRF) data (Ryan et al 2005). To make the transition to SXRF, it was necessary to modify the program to calculate accurate theoretical X-ray yields generated by incoming photons for a given composition of sample, experimental geometry and beam energy.…”

Section: Experimental Methodsmentioning

confidence: 99%

The Oxidation State of Europium in Hydrothermal Scheelite: In Situ Measurement by Xanes Spectroscopy

Brugger

Chu

Harland

et al. 2006

The Canadian Mineralogist

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X-ray microfl uorescence and EuL 3 micro-X-ray absorption near-edge structure (XANES) spectroscopy were conducted to determine the distribution and valence state of europium in two samples of scheelite (CaWO 4 ) containing between 40 and 350 ppm Eu. The samples come from hydrothermal gold deposits: the Archean Drysdale deposit in Kalgoorlie, Western Australia (DRY1) and the Caledonian, intrusion-related Stepnyak deposit in Kazakhstan (USP31). Laser-ablation ICP-MS analyses reveal that both samples are characterized by bell-shape chondrite-normalized REE patterns with a maximum enrichment around Eu, and a small positive or no Eu anomaly. USP31 displays a complex zoning between this pattern and a strongly LREE-enriched pattern with a strong positive Eu-anomaly. The XANES spectroscopy reveals the coexistence of Eu 2+ and Eu 3+ in both scheelite samples DRY1 and USP31. The oxidation of Eu in USP31 appears to be inhomogeneous within a single crystal, with zones containing a mixture of Eu 2+ and Eu 3+ and zones containing more than 90% Eu 2+ . This study shows that it is possible to obtain semiquantitative element-distribution maps for LREE as well as, in optimal conditions, EuL 3 XANES spectra on a bending magnet beamline equipped with a solid-state detector.

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Nuclear microprobe – synchrotron synergy: Towards integrated quantitative real-time elemental imaging using PIXE and SXRF

Cited by 142 publications

References 11 publications

Therapeutic targeting and rapid mobilization of endosteal HSC using a small molecule integrin antagonist

Therapeutic targeting and rapid mobilization of endosteal HSC using a small molecule integrin antagonist

In Situ Speciation and Distribution of Toxic Selenium in Hydrated Roots of Cowpea

The Oxidation State of Europium in Hydrothermal Scheelite: In Situ Measurement by Xanes Spectroscopy

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