1. (13) C magnetic resonance spectroscopy measurements with hyperpolarized [1-(13) C] pyruvate can be used to detect the expression of transgenic pyruvate decarboxylase activity in vivo.

    Magnetic Resonance in Medicine 76(2):391 (2016) PMID 26388418

    Dissolution dynamic nuclear polarization can increase the sensitivity of the (13) C magnetic resonance spectroscopy experiment by at least four orders of magnitude and offers a novel approach to the development of MRI gene reporters based on enzymes that metabolize (13) C-labeled tracers. We des...
  2. Design and validation of a near-infrared fluorescence endoscope for detection of early esophageal malignancy.

    Journal of Biomedical Optics 21(8):84001 (2016) PMID 27490221

  3. Effects of fasting on serial measurements of hyperpolarized [1-(13) C]pyruvate metabolism in tumors.

    NMR in Biomedicine 29(8):1048 (2016) PMID 27309986 PMCID PMC4973679

    Imaging of the metabolism of hyperpolarized [1-(13) C]pyruvate has shown considerable promise in preclinical studies in oncology, particularly for the assessment of early treatment response. The repeatability of measurements of (13) C label exchange between pyruvate and lactate was determined in...
  4. Development of Timd2 as a reporter gene for MRI.

    Magnetic Resonance in Medicine 75(4):1697 (2016) PMID 25981669 PMCID PMC4832381

    To assess the potential of an MRI gene reporter based on the ferritin receptor Timd2 (T-cell immunoglobulin and mucin domain containing protein 2), using T1- and T2-weighted imaging. Pellets of cells that had been modified to express the Timd2 transgene, and incubated with either iron-loaded or ...
  5. A comparison of quantitative methods for clinical imaging with hyperpolarized (13)C-pyruvate.

    NMR in Biomedicine 29(4):387 (2016) PMID 27414749 PMCID PMC4833181

    Dissolution dynamic nuclear polarization (DNP) enables the metabolism of hyperpolarized (13)C-labelled molecules, such as the conversion of [1-(13)C]pyruvate to [1-(13)C]lactate, to be dynamically and non-invasively imaged in tissue. Imaging of this exchange reaction in animal models has been sh...
  6. 31P magnetization transfer measurements of Pi→ATP flux in exercising human muscle.

    Journal of Applied Physiology 120(6):649 (2016) PMID 26744504 PMCID PMC4796179

    Fundamental criticisms have been made over the use of (31)P magnetic resonance spectroscopy (MRS) magnetization transfer estimates of inorganic phosphate (Pi)→ATP flux (VPi-ATP) in human resting skeletal muscle for assessing mitochondrial function. Although the discrepancy in the magnitude of VP...
  7. MRI with hyperpolarised [1-13C]pyruvate detects advanced pancreatic preneoplasia prior to invasive disease in a mouse model.

    Gut 65(3):465 (2016) PMID 26347531 PMCID PMC4789827

    Pancreatic cancer (PCa) is treatable by surgery when detected at an early stage. Non-invasive imaging methods able to detect both established tumours and their precursor lesions are needed to select patients for surgery. We investigated here whether pancreatic preneoplasia could be detected prio...
  8. Imaging Glycosylation In Vivo by Metabolic Labeling and Magnetic Resonance Imaging.

    Angewandte Chemie. International edition in Eng... 55(4):1286 (2016) PMID 26633082 PMCID PMC4737346

    Glycosylation is a ubiquitous post-translational modification, present in over 50% of the proteins in the human genome, with important roles in cell-cell communication and migration. Interest in glycome profiling has increased with the realization that glycans can be used as biomarkers of many d...
  9. Detection of colorectal dysplasia using fluorescently labelled lectins.

    Scientific reports 6:24231 (2016) PMID 27071814 PMCID PMC4829854

    Colorectal cancer screening using conventional colonoscopy lacks molecular information and can miss dysplastic lesions. We tested here the ability of fluorescently labelled lectins to distinguish dysplasia from normal tissue when sprayed on to the luminal surface epithelium of freshly resected c...
  10. Potential Clinical Roles for Metabolic Imaging with Hyperpolarized [1-(13)C]Pyruvate.

    Frontiers in Oncology 6:59 (2016) PMID 27014634 PMCID PMC4786548

  11. Hyperpolarized [U-(2) H, U-(13) C]Glucose reports on glycolytic and pentose phosphate pathway activity in EL4 tumors and glycolytic activity in yeast cells.

    Magnetic Resonance in Medicine 74(6):1543 (2015) PMID 25522215

    A resonance at ∼181 ppm in the (13) C spectra of tumors injected with hyperpolarized [U-(2) H, U-(13) C]glucose was assigned to 6-phosphogluconate (6PG), as in previous studies in yeast, whereas in breast cancer cells in vitro this resonance was assigned to 3-phosphoglycerate (3PG). These peak a...
  12. Carbonic Anhydrase Activity Monitored In Vivo by Hyperpolarized 13C-Magnetic Resonance Spectroscopy Demonstrates Its Importance for pH Regulation in Tumors.

    Cancer Research 75(19):4109 (2015) PMID 26249175 PMCID PMC4594768

    Carbonic anhydrase buffers tissue pH by catalyzing the rapid interconversion of carbon dioxide (CO2) and bicarbonate (HCO3 (-)). We assessed the functional activity of CAIX in two colorectal tumor models, expressing different levels of the enzyme, by measuring the rate of exchange of hyperpolari...
  13. Imaging metabolism with hyperpolarized (13)C-labeled cell substrates.

    Journal of the American Chemical Society 137(20):6418 (2015) PMID 25950268

    Non-invasive (13)C magnetic resonance spectroscopy measurements of the uptake and subsequent metabolism of (13)C-labeled substrates is a powerful method for studying metabolic fluxes in vivo. However, the technique has been hampered by a lack of sensitivity, which has limited both the spatial an...
  14. (13) C magnetic resonance spectroscopic imaging of hyperpolarized [1-(13) C, U-(2) H5 ] ethanol oxidation can be used to assess aldehyde dehydrogenase activity in vivo.

    Magnetic Resonance in Medicine 73(5):1733 (2015) PMID 24800934

    Aldehyde dehydrogenase (ALDH2) is an emerging drug target for the treatment of heart disease, cocaine and alcohol dependence, and conditions caused by genetic polymorphisms in ALDH2. Noninvasive measurement of ALDH2 activity in vivo could inform the development of these drugs and accelerate thei...
  15. Detection of transgene expression using hyperpolarized 13C urea and diffusion-weighted magnetic resonance spectroscopy.

    Magnetic Resonance in Medicine 73(4):1401 (2015) PMID 24733406

    To assess the potential of a gene reporter system, based on a urea transporter (UTB) and hyperpolarized [(13) C]urea. Mice were implanted subcutaneously with either unmodified control cells or otherwise identical cells expressing UTB. After injection of hyperpolarized [(13) C]urea, a spin echo s...
  16. Identifying active vascular microcalcification by (18)F-sodium fluoride positron emission tomography.

    Nature Communications 6:7495 (2015) PMID 26151378 PMCID PMC4506997

    Vascular calcification is a complex biological process that is a hallmark of atherosclerosis. While macrocalcification confers plaque stability, microcalcification is a key feature of high-risk atheroma and is associated with increased morbidity and mortality. Positron emission tomography and X-...
  17. Imaging tumor metabolism using positron emission tomography.

    The Cancer Journal 21(2):129 (2015) PMID 25815854 PMCID PMC4413031

    Positron emission tomography (PET) is an extraordinarily sensitive clinical imaging modality for interrogating tumor metabolism. Radiolabeled PET substrates can be traced at subphysiological concentrations, allowing noninvasive imaging of metabolism and intratumoral heterogeneity in systems rang...
  18. CARS based label-free assay for assessment of drugs by monitoring lipid droplets in tumour cells.

    Journal of Biophotonics 7(11-12):906 (2014) PMID 24343869

    Coherent anti-Stokes Raman scattering (CARS) is becoming an established tool for label-free multi-photon imaging based on molecule specific vibrations in the sample. The technique has proven to be particularly useful for imaging lipids, which are abundant in cells and tissues, including cytoplas...
  19. Oatp1 enhances bioluminescence by acting as a plasma membrane transporter for D-luciferin.

    Molecular Imaging & Biology 16(5):626 (2014) PMID 24798747 PMCID PMC4161938

    Bioluminescence imaging is a powerful tool for studying gene expression and cell migration in intact living organisms. However, production of bioluminescence by cells transfected to express luciferase can be limited by the rate of plasma membrane transport of its substrate D-luciferin. We sought...
  20. Late Imaging with [1-(11)C]Acetate Improves Detection of Tumor Fatty Acid Synthesis with PET.

    Journal of nuclear medicine : official publicat... 55(7):1144 (2014) PMID 24777291

    Tumors are often characterized by high levels of de novo fatty acid synthesis. The kinetics of acetate incorporation into tricarboxylic acid cycle intermediates and into lipids suggest that detection of tumors with [1-(11)C]acetate PET could be improved by imaging at later time points. The uptak...