A hard x-ray scanning microprobe for fluorescence imaging and microdiffraction at the advanced photon source

Cai, Zhengguo; Lai, Barry; Wang, Yun; Ilinski, P.; Legnini, D.; Mäser, J.; Rodrigues, W.

doi:10.1063/1.1291193

Cited by 27 publications

(18 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A hard X-ray microprobe (Cai et al, 2000) was used to collect quantitative maps of the elemental distribution in the macrophage and the phagosome. Details regarding data collection have been described previously (Maser et al, 2003).…”

Section: Methodsmentioning

confidence: 99%

“…Twenty atomic species can be measured and quantified simultaneously without physical sectioning of the specimen and without need for additional staining, such as the use of fluorescent dyes (Cai et al, 2000). Using this approach, that combines high elemental sensitivity (sub-femtogram) and low background with high spatial resolution (150 nm), we have shown that M. tuberculosis and M. avium, but not the avirulent Mycobacterium smegmatis, accumulate Fe in the phagosome, at least in part, through the activity of the transferrin receptor.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Changes of the phagosomal elemental concentrations by Mycobacterium tuberculosis Mramp

et al. 2005

View full text Add to dashboard Cite

Pathogenic mycobacteria survive within phagosomes which are thought to represent a nutrient-restricted environment. Divalent cation transporters of the Nramp family in phagosomes and mycobacteria (Mramp) may compete for metals that are crucial for bacterial survival. The elemental concentrations in phagosomes of macrophages infected with wild-type Mycobacterium tuberculosis (M. tuberculosis strain H37Rv) and a M. tuberculosis Mramp knockout mutant (Mramp-KO), derived from a clinical isolate isogenic to the strain MT103, were compared. Time points of 1 and 24 h after infection of mouse peritoneal macrophages (bcg S ) were compared in both cases. Increased concentrations of P, Ni and Zn and reduced Cl concentration in Mramp-KO after 1 h of infection were observed, compared to M. tuberculosis vacuoles. After 24 h of infection, significant differences in the P, Cl and Zn concentrations were still present. The Mramp-KO phagosome showed a significant increase of P, Ca, Mn, Fe and Zn concentrations between 1 and 24 h after infection, while the concentrations of K and Ni decreased. In the M. tuberculosis vacuole, the Fe concentration showed a similar increase, while the Cl concentration decreased. The fact that the concentration of several divalent cations increased in the Mramp-KO strain suggests that Mramp may have no impact on the import of these divalent cations into the mycobacterium, but may function as a cation efflux pump. The concordant increase of Fe concentrations within M. tuberculosis, as well as within the Mramp-KO vacuoles, implies that Mramp, in contrast to siderophores, might not be important for the attraction of Fe and its retention in phagosomes of unstimulated macrophages.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Changes of the phagosomal elemental concentrations by Mycobacterium tuberculosis Mramp

et al. 2005

View full text Add to dashboard Cite

show abstract

“…Scanning x-ray fluorescence microscopy was performed at Beamline 2-ID-D of the Advanced Photon Source at the Argonne National Laboratory (Cai et al, 2000). Incident x-rays of 10 keV were chosen to excite elements from P to Zn.…”

Section: High-resolution Sxrf Microscopymentioning

confidence: 99%

The Role of CAX1 and CAX3 in Elemental Distribution and Abundance in Arabidopsis Seed

et al. 2012

View full text Add to dashboard Cite

The ability to alter nutrient partitioning within plants cells is poorly understood. In Arabidopsis (Arabidopsis thaliana), a family of endomembrane cation exchangers (CAXs) transports Ca 2+ and other cations. However, experiments have not focused on how the distribution and partitioning of calcium (Ca) and other elements within seeds are altered by perturbed CAX activity. Here, we investigate Ca distribution and abundance in Arabidopsis seed from cax1 and cax3 loss-of-function lines and lines expressing deregulated CAX1 using synchrotron x-ray fluorescence microscopy. We conducted 7-to 10-mm resolution in vivo x-ray microtomography on dry mature seed and 0.2-mm resolution x-ray microscopy on embryos from lines overexpressing deregulated CAX1 (35S-sCAX1) and cax1cax3 double mutants only. Tomograms showed an increased concentration of Ca in both the seed coat and the embryo in cax1, cax3, and cax1cax3 lines compared with the wild type. High-resolution elemental images of the mutants showed that perturbed CAX activity altered Ca partitioning within cells, reducing Ca partitioning into organelles and/or increasing Ca in the cytosol and abolishing tissue-level Ca gradients. In comparison with traditional volume-averaged metal analysis, which confirmed subtle changes in seed elemental composition, the collection of spatially resolved data at varying resolutions provides insight into the impact of altered CAX activity on seed metal distribution and indicates a cell type-specific function of CAX1 and CAX3 in partitioning Ca into organelles. This work highlights a powerful technology for inferring transport function and quantifying nutrient changes.

show abstract

“…Scanning X-ray fluorescence microscopy was performed at the 2-ID-D beamline of the Advanced Photon Source at Argonne National Laboratory (IL, USA) (Cai et al , 2000). The source was a 3.3-cm-period undulator, and x-rays were monochromatized by a double-crystal Si(111) monochromator.…”

Section: Methodsmentioning

confidence: 99%

N,N-diethyldithiocarbamate promotes oxidative stress prior to myelin structural changes and increases myelin copper content

Viquez

Lai

Ahn

et al. 2009

Toxicology and Applied Pharmacology

View full text Add to dashboard Cite

Dithiocarbamates are a commercially important class of compounds that can produce peripheral neuropathy in humans and experimental animals. Previous studies have supported a requirement for copper accumulation and enhanced lipid peroxidation in dithiocarbamate-mediated myelinopathy. The study presented here extends previous investigations in two areas. Firstly, although total copper levels have been shown to increase within nerve it has not been determined whether copper is increased within the myelin compartment, the primary site of lesion development. Therefore, the distribution of copper in sciatic nerve was characterized using synchrotron X-ray fluorescence microscopy to determine whether the neurotoxic dithiocarbamate, N,N-diethyldithiocarbamate, increases copper levels in myelin. Secondly, because lipid peroxidation is an ongoing process in normal nerve and the levels of lipid peroxidation products produced by dithiocarbamate exposure demonstrated an unusual cumulative dose response in previous studies the biological impact of dithiocarbamate-mediated lipid peroxidation was evaluated. Experiments were performed to determine whether dithiocarbamate-mediated lipid peroxidation products elicit an antioxidant response through measuring the protein expression levels of three enzymes, superoxide dismutase 1, heme oxygenase 1, and glutathione transferase a, that are linked to the antioxidant response element promoter. To establish the potential of oxidative injury to contribute to myelin injury the temporal relationship of the antioxidant response to myelin injury was determined. Myelin structure in peripheral nerve was assessed using multi-exponential transverse relaxation measurements (MET 2 ) as a function of exposure duration, and the temporal relationship of protein expression changes relative to the onset of changes in myelin integrity were determined. Initial assessments were also performed to explore the potential contribution of dithiocarbamate-mediated inhibition of proteasome function and inhibition of cuproenzyme activity to neurotoxicity, and also to assess the Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Conflict of interest statementThe authors declare that there are no conflicts of interest. potential of dithiocarbamates to promote oxidative stress and injury within the central nervous system. These evaluations were performed using an established model for dithiocarbamate-mediated demyelination in the rat utilizing sciatic nerve, spinal cord and brain samples obtained from rats exposed to N,N-diethylditiocarbamate (DEDC) by intra-abdominal pumps ...

show abstract

A hard x-ray scanning microprobe for fluorescence imaging and microdiffraction at the advanced photon source

Cited by 27 publications

References 0 publications

Changes of the phagosomal elemental concentrations by Mycobacterium tuberculosis Mramp

Changes of the phagosomal elemental concentrations by Mycobacterium tuberculosis Mramp

The Role of CAX1 and CAX3 in Elemental Distribution and Abundance in Arabidopsis Seed

N,N-diethyldithiocarbamate promotes oxidative stress prior to myelin structural changes and increases myelin copper content

Contact Info

Product

Resources

About