1
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Pringle TA, Ramon-Gil E, Leslie J, Oakley F, Wright MC, Knight JC, Luli S. Synthesis and preclinical evaluation of a 89Zr-labelled human single chain antibody for non-invasive detection of hepatic myofibroblasts in acute liver injury. Sci Rep 2024; 14:633. [PMID: 38182623 PMCID: PMC10770171 DOI: 10.1038/s41598-023-50779-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 12/25/2023] [Indexed: 01/07/2024] Open
Abstract
Synaptophysin is expressed on fibrogenic hepatic myofibroblasts. C1-3 is a single chain human antibody (scAb) that binds specifically to synaptophysin on hepatic myofibroblasts, providing a targeting vector for novel in vivo imaging agents of chronic liver disease. C1-3 and a negative control scAb, CSBD9, were radiolabelled with zirconium-89 via desferrioxamine chelation to enable non-invasive molecular imaging with positron emission tomography (PET). DFO-scAb conjugates were characterised by gel electrophoresis (SDS-PAGE) and MALDI-TOF spectrometry, and 89Zr-labelled with high radiolabelling efficiency (99%). [89Zr]Zr-DFO-C1-3 exhibited high in vitro stability (> 99%) in mouse and human sera over 3 days at 25 and 37 °C. Activated hepatic myofibroblasts incubated with [89Zr]Zr-DFO-C1-3 displayed significantly higher internalised activity (59.46%, P = 0.001) compared to the [89Zr]Zr-DFO-CSBD9 control, indicating synaptophysin-mediated uptake and high binding specificity of [89Zr]Zr-DFO-C1-3. Mice with CCl4-induced acute liver damage exhibited significantly higher liver uptake of [89Zr]Zr-DFO-C1-3, compared to controls, confirmed by both Cerenkov imaging and ex vivo gamma counting (4.41 ± 0.19%ID/g, P < 0.0001). CCl4-induced liver damage and the number of hepatic myofibroblasts was confirmed by αSMA staining of liver sections. These findings indicate that [89Zr]Zr-DFO-C1-3 has promising utility as a PET imaging agent for non-invasive detection of hepatic myofibroblasts following acute liver injury.
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Affiliation(s)
- Toni A Pringle
- School of Natural and Environmental Sciences, Newcastle University, Bedson Building, Newcastle upon Tyne, NE1 7RU, UK
| | - Erik Ramon-Gil
- Newcastle Fibrosis Research Group, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
- Newcastle Centre for Cancer, Newcastle University, Newcastle upon Tyne, UK
| | - Jack Leslie
- Newcastle Fibrosis Research Group, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
- Newcastle Centre for Cancer, Newcastle University, Newcastle upon Tyne, UK
| | - Fiona Oakley
- Newcastle Fibrosis Research Group, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
- Newcastle Centre for Cancer, Newcastle University, Newcastle upon Tyne, UK
| | - Matthew C Wright
- Liver Research Group, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK
| | - James C Knight
- School of Natural and Environmental Sciences, Newcastle University, Bedson Building, Newcastle upon Tyne, NE1 7RU, UK.
- Newcastle Centre for Cancer, Newcastle University, Newcastle upon Tyne, UK.
| | - Saimir Luli
- Newcastle Fibrosis Research Group, Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK.
- Newcastle Centre for Cancer, Newcastle University, Newcastle upon Tyne, UK.
- Preclinical In Vivo Imaging, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK.
- Medical School, Newcastle University, 4th Floor William Leech Building, Newcastle upon Tyne, NE2 4HH, UK.
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2
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Gristwood K, Luli S, Rankin KS, Knight JC. Synthesis and In Vitro Evaluation of a HER2-Specific ImmunoSCIFI Probe. ACS Omega 2023; 8:47905-47912. [PMID: 38144136 PMCID: PMC10734019 DOI: 10.1021/acsomega.3c06452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 11/07/2023] [Accepted: 11/20/2023] [Indexed: 12/26/2023]
Abstract
Secondary Cerenkov-induced fluorescence imaging (SCIFI) is an emerging biomedical optical imaging modality that leverages Cerenkov luminescence, primarily generated by β-emitting radioisotopes, to excite fluorophores that offer near-infrared emissions with optimal tissue penetrance. Dual-functionalized immunoconjugates composed of an antibody, a near-infrared fluorophore, and a β-emitting radioisotope have potential utility as novel SCIFI constructs with high specificity for molecular biomarkers of disease. Here, we report the synthesis and characterization of [89Zr]Zr-DFO-trastuzumab-BOD665, a self-excitatory HER2-specific "immunoSCIFI" probe capable of yielding near-infrared fluorescence in situ without external excitation. The penetration depth of the SCIFI signal was measured in hemoglobin-infused optical tissue phantoms that indicated a 2.05-fold increase compared to 89Zr-generated Cerenkov luminescence. Additionally, the binding specificity of the immunoSCIFI probe for HER2 was evaluated in a cellular assay that showed significantly higher binding to SKBR3 (high HER2 expression) relative to MDA-MB-468 (low HER2) breast cancer cells based on measurements of total flux in the near-infrared region with external excitation blocked. Taken together, the results of this study indicate the potential utility of immunoSCIFI constructs for interrogation of molecular biomarkers of disease.
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Affiliation(s)
- Katie Gristwood
- School
of Natural and Environmental Sciences, Newcastle
University, Bedson Building, Newcastle upon Tyne NE1 7RU, U.K.
| | - Saimir Luli
- Preclinical
In Vivo Imaging, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, U.K.
| | - Kenneth S. Rankin
- Translational
and Clinical Research Institute, Newcastle
University, Newcastle upon Tyne NE1 7RU, U.K.
| | - James C. Knight
- School
of Natural and Environmental Sciences, Newcastle
University, Bedson Building, Newcastle upon Tyne NE1 7RU, U.K.
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3
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Ogawa Y, Nicholas S, Thyselius M, Leibbrandt R, Nowotny T, Knight JC, Nordström K. Descending neurons of the hoverfly respond to pursuits of artificial targets. Curr Biol 2023; 33:4392-4404.e5. [PMID: 37776861 DOI: 10.1016/j.cub.2023.08.091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/11/2023] [Accepted: 08/31/2023] [Indexed: 10/02/2023]
Abstract
Many animals use motion vision information to control dynamic behaviors. Predatory animals, for example, show an exquisite ability to detect rapidly moving prey, followed by pursuit and capture. Such target detection is not only used by predators but is also important in conspecific interactions, such as for male hoverflies defending their territories against conspecific intruders. Visual target detection is believed to be subserved by specialized target-tuned neurons found in a range of species, including vertebrates and arthropods. However, how these target-tuned neurons respond to actual pursuit trajectories is currently not well understood. To redress this, we recorded extracellularly from target-selective descending neurons (TSDNs) in male Eristalis tenax hoverflies. We show that they have dorso-frontal receptive fields with a preferred direction up and away from the visual midline. We reconstructed visual flow fields as experienced during pursuits of artificial targets (black beads). We recorded TSDN responses to six reconstructed pursuits and found that each neuron responded consistently at remarkably specific time points but that these time points differed between neurons. We found that the observed spike probability was correlated with the spike probability predicted from each neuron's receptive field and size tuning. Interestingly, however, the overall response rate was low, with individual neurons responding to only a small part of each reconstructed pursuit. In contrast, the TSDN population responded to substantially larger proportions of the pursuits but with lower probability. This large variation between neurons could be useful if different neurons control different parts of the behavioral output.
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Affiliation(s)
- Yuri Ogawa
- Flinders Health and Medical Research Institute, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia
| | - Sarah Nicholas
- Flinders Health and Medical Research Institute, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia
| | - Malin Thyselius
- Department of Medical Cell Biology, Uppsala University, 75123 Uppsala, Sweden; School of Medical Sciences, Faculty of Medicine and Health, Örebro University, Örebro 701 82, Sweden
| | - Richard Leibbrandt
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia
| | - Thomas Nowotny
- School of Engineering and Informatics, University of Sussex, Brighton BN1 9QJ, UK
| | - James C Knight
- School of Engineering and Informatics, University of Sussex, Brighton BN1 9QJ, UK
| | - Karin Nordström
- Flinders Health and Medical Research Institute, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia; Department of Medical Cell Biology, Uppsala University, 75123 Uppsala, Sweden.
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4
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Aimone JB, Awile O, Diesmann M, Knight JC, Nowotny T, Schürmann F. Editorial: Neuroscience, computing, performance, and benchmarks: Why it matters to neuroscience how fast we can compute. Front Neuroinform 2023; 17:1157418. [PMID: 37064716 PMCID: PMC10098318 DOI: 10.3389/fninf.2023.1157418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 03/08/2023] [Indexed: 04/03/2023] Open
Affiliation(s)
- James B. Aimone
- Neural Exploration and Research Laboratory, Center for Computing Research, Sandia National Laboratories, Albuquerque, NM, United States
| | - Omar Awile
- Blue Brain Project, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Markus Diesmann
- Institute of Neuroscience and Medicine and Institute for Advanced Simulation and JARA-Institute Brain Structure-Function Relationships, Jülich Research Centre, Jülich, Germany
- Department of Physics, Faculty 1, RWTH Aachen University, Aachen, Germany
- Department of Psychiatry, Psychotherapy and Psychosomatics, School of Medicine, RWTH Aachen University, Aachen, Germany
| | - James C. Knight
- School of Engineering and Informatics, University of Sussex, Brighton, United Kingdom
| | - Thomas Nowotny
- School of Engineering and Informatics, University of Sussex, Brighton, United Kingdom
| | - Felix Schürmann
- Blue Brain Project, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland
- *Correspondence: Felix Schürmann
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5
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Maclean P, Mentzer AJ, Lambe T, Knight JC. Response to Letter to the Editor by Ish et al. entitled 'COVID-19 vaccine equity-the need of the hour'. QJM 2023; 116:86. [PMID: 35092292 PMCID: PMC9383372 DOI: 10.1093/qjmed/hcac024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- P Maclean
- Address correspondence to Dr P. Maclean, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK.
| | - A J Mentzer
- From the Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive Headington, Oxford, UK
| | - T Lambe
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Churchill Hospital Old Road Headington, Oxford, UK
- Chinese Academy of Medical Science (CAMS) Oxford Institute, Nuffield Department of Medicine, University of Oxford, Old Road Campus Headington, Oxford, UK
| | - J C Knight
- From the Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive Headington, Oxford, UK
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6
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Gristwood K, Luli S, Rankin KS, Knight JC. In situ excitation of BODIPY fluorophores by 89Zr-generated Cerenkov luminescence. Chem Commun (Camb) 2022; 58:11689-11692. [PMID: 36173358 DOI: 10.1039/d2cc03875g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Secondary Cerenkov-induced fluorescence imaging (SCIFI) is an emerging optical imaging technology that affords high signal-to-noise images by utilising radionuclide-generated Cerenkov luminescence to excite fluorescent probes. BODIPY dyes offer attractive properties for SCIFI, including high quantum yields and photochemical stability, yet their utility in this application in combination with clinically relevant β+-emitting radioisotopes remains largely unexplored. In this report, the fluorescence properties of three meso-substituted BODIPY analogues have been assessed in combination with the positron emitter zirconium-89. Most notably, SCIFI data acquired over 7 days shows the BODIPY scaffold remain largely inert to radiolysis, indicating the promising utility of this fluorophore class in SCIFI applications.
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Affiliation(s)
- Katie Gristwood
- School of Natural and Environmental Sciences, Faculty of Science, Agriculture and Engineering, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK.
| | - Saimir Luli
- Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle, Newcastle Upon Tyne, NE2 4HH, UK.
| | - Kenneth S Rankin
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, NE2 4HH, UK.
| | - James C Knight
- School of Natural and Environmental Sciences, Faculty of Science, Agriculture and Engineering, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK.
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7
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Pringle TA, Chan CD, Luli S, Blair HJ, Rankin KS, Knight JC. Synthesis and In Vivo Evaluation of a Site-specifically Labeled Radioimmunoconjugate for Dual-Modal (PET/NIRF) Imaging of MT1-MMP in Sarcomas. Bioconjug Chem 2022; 33:1564-1573. [PMID: 35867034 PMCID: PMC9389524 DOI: 10.1021/acs.bioconjchem.2c00306] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Bone sarcomas are devastating primary bone cancers that
mostly
affect children, young adults, and the elderly. These aggressive tumors
are associated with poor survival, and surgery remains the mainstay
of treatment. Surgical planning is increasingly informed by positron
emission tomography (PET), and tumor margin identification during
surgery is aided by near-infrared fluorescence (NIRF) imaging, yet
these investigations are confounded by probes that lack specificity
for sarcoma biomarkers. We report the development of a dual-modal
(PET/NIRF) immunoconjugate ([89Zr]Zr-DFO-anti-MT1-MMP-IRDye800CW)
that targets MT1-MMP, a matrix metalloproteinase overexpressed in
high-grade sarcomas. [89Zr]Zr-DFO-anti-MT1-MMP-IRDye800CW
was synthesized via site-specific chemoenzymatic
glycan modification, characterized, and isolated in high specific
activity and radiochemical purity. Saturation binding and immunoreactivity
assays indicated only minor perturbation of binding properties. A
novel mouse model of dedifferentiated chondrosarcoma based on intrafemoral
inoculation of HT1080 WT or KO cells (high and low MT1-MMP expression,
respectively) was used to evaluate target binding and biodistribution.
Fluorescence and Cerenkov luminescence images of [89Zr]Zr-DFO-anti-MT1-MMP-IRDye800CW
showed preferential uptake in HT1080 WT tumors. Ex vivo gamma counting revealed that uptake in MT1-MMP-positive tumors was
significantly higher than that in control groups. Taken together,
[89Zr]Zr-DFO-anti-MT1-MMP-IRDye800CW is a promising dual-modal
sarcoma imaging agent for pre-operative surgical planning and intraoperative
surgical guidance.
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Affiliation(s)
- Toni A Pringle
- School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne NE1 7RU, U.K
| | - Corey D Chan
- North of England Bone and Soft Tissue Tumour Service, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Freeman Road, Newcastle Upon Tyne NE7 7DN, U.K.,Translational and Clinical Research Institute, Newcastle University, Newcastle Upon Tyne NE1 7RU, U.K
| | - Saimir Luli
- Preclinical In Vivo Imaging, Translational and Clinical Research Institute, Newcastle University, Newcastle Upon Tyne NE2 4HH, U.K
| | - Helen J Blair
- Translational and Clinical Research Institute, Newcastle University, Newcastle Upon Tyne NE1 7RU, U.K.,Wolfson Childhood Cancer Research Centre, Newcastle Upon Tyne NE1 7RY, U.K
| | - Kenneth S Rankin
- North of England Bone and Soft Tissue Tumour Service, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Freeman Road, Newcastle Upon Tyne NE7 7DN, U.K.,Translational and Clinical Research Institute, Newcastle University, Newcastle Upon Tyne NE1 7RU, U.K
| | - James C Knight
- School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne NE1 7RU, U.K.,Newcastle Centre for Cancer, Newcastle University, Newcastle Upon Tyne NE1 7RU, U.K
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8
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Pringle TA, Coleman O, Kawamura A, Knight JC. The influence of degree of labelling upon cellular internalisation of antibody-cell penetrating peptide conjugates. RSC Adv 2022; 12:27716-27722. [PMID: 36320284 PMCID: PMC9517169 DOI: 10.1039/d2ra05274a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 09/20/2022] [Indexed: 11/21/2022] Open
Abstract
Antibody-based agents are increasingly used as therapeutics and imaging agents, yet are generally restricted to cell surface targets due to inefficient cellular internalisation and endosomal entrapment. Enhanced cell membrane translocation of antibodies can be achieved by the covalent attachment of cell-penetrating peptides, including the HIV-1-derived transactivator of transcription (TAT) peptide. This study evaluated the cellular internalisation properties of five anti-HER2 Herceptin–TAT conjugates with degrees of TAT labelling (DOLTAT) ranging from one to five. Herceptin–TAT conjugates were synthesised via a strain-promoted alkyne–azide cycloaddition reaction, characterised by UV-vis spectroscopy, MALDI-TOF, and gel electrophoresis, then radiolabelled with zirconium-89 to permit measurement of cellular internalisation by gamma counting. [89Zr]Zr–DFO–Her–TAT(0–5) conjugates were isolated in high radiochemical purity (>99%) and exhibited high stability in murine and human serum over 7 days at 37 °C. Significant increases in cellular internalisation were observed for [89Zr]Zr–DFO–Her–TAT conjugates with DOLTAT values of 2 and above in SKBR3 (high HER2) cells over 48 h, in contrast to low-level non-specific uptake in MDA-MB-468 (low HER2) cells that did not increase over time. Notably, [89Zr]Zr–DFO–Her–TAT conjugates with DOLTAT of 3, 4, and 5 reached uptake values in SKBR3 cells of 5, 6, and 8% of the applied dose at 48 h respectively, representing 9, 10, 14-fold increases relative to the TAT-free control conjugate, [89Zr]Zr–DFO–Her–TAT(0). A systematic investigation into the influence of degree of labelling of antibody-cell penetrating peptide conjugates upon cellular internalisation.![]()
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Affiliation(s)
- Toni A. Pringle
- School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - Oliver Coleman
- School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - Akane Kawamura
- School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne, UK
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - James C. Knight
- School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne, UK
- Newcastle University Centre for Cancer, Newcastle University, Newcastle Upon Tyne, UK
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9
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Abstract
More than half of the Top 10 supercomputing sites worldwide use GPU accelerators and they are becoming ubiquitous in workstations and edge computing devices. GeNN is a C++ library for generating efficient spiking neural network simulation code for GPUs. However, until now, the full flexibility of GeNN could only be harnessed by writing model descriptions and simulation code in C++. Here we present PyGeNN, a Python package which exposes all of GeNN's functionality to Python with minimal overhead. This provides an alternative, arguably more user-friendly, way of using GeNN and allows modelers to use GeNN within the growing Python-based machine learning and computational neuroscience ecosystems. In addition, we demonstrate that, in both Python and C++ GeNN simulations, the overheads of recording spiking data can strongly affect runtimes and show how a new spike recording system can reduce these overheads by up to 10×. Using the new recording system, we demonstrate that by using PyGeNN on a modern GPU, we can simulate a full-scale model of a cortical column faster even than real-time neuromorphic systems. Finally, we show that long simulations of a smaller model with complex stimuli and a custom three-factor learning rule defined in PyGeNN can be simulated almost two orders of magnitude faster than real-time.
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Affiliation(s)
- James C. Knight
- Centre for Computational Neuroscience and Robotics, School of Engineering and Informatics, University of Sussex, Brighton, United Kingdom
| | - Anton Komissarov
- Bernstein Center for Computational Neuroscience Berlin, Berlin, Germany
- Department of Engineering and Computer Science, Technische Universität Berlin, Berlin, Germany
| | - Thomas Nowotny
- Centre for Computational Neuroscience and Robotics, School of Engineering and Informatics, University of Sussex, Brighton, United Kingdom
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10
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Knight JC, Nowotny T. Larger GPU-accelerated brain simulations with procedural connectivity. Nat Comput Sci 2021; 1:136-142. [PMID: 38217218 DOI: 10.1038/s43588-020-00022-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 12/23/2020] [Indexed: 01/15/2024]
Abstract
Simulations are an important tool for investigating brain function but large models are needed to faithfully reproduce the statistics and dynamics of brain activity. Simulating large spiking neural network models has, until now, needed so much memory for storing synaptic connections that it required high performance computer systems. Here, we present an alternative simulation method we call 'procedural connectivity' where connectivity and synaptic weights are generated 'on the fly' instead of stored and retrieved from memory. This method is particularly well suited for use on graphical processing units (GPUs)-which are a common fixture in many workstations. Using procedural connectivity and an additional GPU code generation optimization, we can simulate a recent model of the macaque visual cortex with 4.13 × 106 neurons and 24.2 × 109 synapses on a single GPU-a significant step forward in making large-scale brain modeling accessible to more researchers.
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Affiliation(s)
- James C Knight
- Centre for Computational Neuroscience and Robotics, School of Engineering and Informatics, University of Sussex, Brighton, UK.
| | - Thomas Nowotny
- Centre for Computational Neuroscience and Robotics, School of Engineering and Informatics, University of Sussex, Brighton, UK
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11
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Knight JC, Torres JB, Goldin R, Mosley M, Dias GM, Bravo LC, Kersemans V, Allen PD, Mukherjee S, Smart S, Cornelissen B. Early Detection in a Mouse Model of Pancreatic Cancer by Imaging DNA Damage Response Signaling. J Nucl Med 2020; 61:1006-1013. [PMID: 31862800 PMCID: PMC7383084 DOI: 10.2967/jnumed.119.234708] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 11/21/2019] [Indexed: 01/01/2023] Open
Abstract
Despite its widespread use in oncology, the PET radiotracer 18F-FDG is ineffective for improving early detection of pancreatic ductal adenocarcinoma (PDAC). An alternative strategy for early detection of pancreatic cancer involves visualization of high-grade pancreatic intraepithelial neoplasias (PanIN-3s), generally regarded as the noninvasive precursors of PDAC. The DNA damage response is known to be hyperactivated in late-stage PanINs. Therefore, we investigated whether the SPECT imaging agent 111In-anti-γH2AX-TAT allows visualization of the DNA damage repair marker γH2AX in PanIN-3s in an engineered mouse model of PDAC, to facilitate early detection of PDAC. Methods: Genetically engineered KPC (KRasLSL.G12D/+; p53LSL.R172H/+; PdxCre) mice were imaged with 18F-FDG and 111In-anti-γH2AX-TAT. The presence of PanIN/PDAC as visualized by histologic examination was compared with autoradiography and immunofluorescence. Separately, the survival of KPC mice imaged with 111In-anti-γH2AX-TAT was evaluated. Results: In KPC mouse pancreata, γH2AX expression was increased in high-grade PanINs but not in PDAC, corroborating earlier results obtained from human pancreas sections. Uptake of 111In-anti-γH2AX-TAT, but not 111In-IgG-TAT or 18F-FDG, within the pancreas correlated positively with the age of KPC mice, which correlated with the number of high-grade PanINs. 111In-anti-γH2AX-TAT localizes preferentially in high-grade PanIN lesions but not in established PDAC. Younger, non-tumor-bearing KPC mice that show uptake of 111In-anti-γH2AX-TAT in the pancreas survive for a significantly shorter time than mice with physiologic 111In-anti-γH2AX-TAT uptake. Conclusion:111In-anti-γH2AX-TAT imaging allows noninvasive detection of DNA damage repair signaling upregulation in preinvasive PanIN lesions and is a promising new tool to aid in the early detection and staging of pancreatic cancer.
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Affiliation(s)
- James C Knight
- Department of Oncology, CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom; and
| | - Julia Baguña Torres
- Department of Oncology, CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Robert Goldin
- Department of Histopathology, Imperial College London, St. Mary's Hospital Campus, London, United Kingdom
| | - Michael Mosley
- Department of Oncology, CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Gemma M Dias
- Department of Oncology, CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Luisa Contreras Bravo
- Department of Oncology, CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Veerle Kersemans
- Department of Oncology, CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - P Danny Allen
- Department of Oncology, CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Somnath Mukherjee
- Department of Oncology, CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Sean Smart
- Department of Oncology, CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Bart Cornelissen
- Department of Oncology, CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
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12
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Haessig G, Milde MB, Aceituno PV, Oubari O, Knight JC, van Schaik A, Benosman RB, Indiveri G. Event-Based Computation for Touch Localization Based on Precise Spike Timing. Front Neurosci 2020; 14:420. [PMID: 32528239 PMCID: PMC7248403 DOI: 10.3389/fnins.2020.00420] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 04/07/2020] [Indexed: 11/13/2022] Open
Abstract
Precise spike timing and temporal coding are used extensively within the nervous system of insects and in the sensory periphery of higher order animals. However, conventional Artificial Neural Networks (ANNs) and machine learning algorithms cannot take advantage of this coding strategy, due to their rate-based representation of signals. Even in the case of artificial Spiking Neural Networks (SNNs), identifying applications where temporal coding outperforms the rate coding strategies of ANNs is still an open challenge. Neuromorphic sensory-processing systems provide an ideal context for exploring the potential advantages of temporal coding, as they are able to efficiently extract the information required to cluster or classify spatio-temporal activity patterns from relative spike timing. Here we propose a neuromorphic model inspired by the sand scorpion to explore the benefits of temporal coding, and validate it in an event-based sensory-processing task. The task consists in localizing a target using only the relative spike timing of eight spatially-separated vibration sensors. We propose two different approaches in which the SNNs learns to cluster spatio-temporal patterns in an unsupervised manner and we demonstrate how the task can be solved both analytically and through numerical simulation of multiple SNN models. We argue that the models presented are optimal for spatio-temporal pattern classification using precise spike timing in a task that could be used as a standard benchmark for evaluating event-based sensory processing models based on temporal coding.
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Affiliation(s)
- Germain Haessig
- Institute of Neuroinformatics, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Moritz B Milde
- International Centre for Neuromorphic Systems, MARCS Institute, Western Sydney University, Penrith, NSW, Australia
| | - Pau Vilimelis Aceituno
- Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany.,Max Planck School of Cognition, Leipzig, Germany
| | - Omar Oubari
- Institut de la Vision, Sorbonne Université, Paris, France
| | - James C Knight
- Centre for Computational Neuroscience and Robotics, School of Engineering and Informatics, University of Sussex, Brighton, United Kingdom
| | - André van Schaik
- International Centre for Neuromorphic Systems, MARCS Institute, Western Sydney University, Penrith, NSW, Australia
| | - Ryad B Benosman
- Institut de la Vision, Sorbonne Université, Paris, France.,University of Pittsburgh, Pittsburgh, PA, United States.,Carnegie Mellon University, Pittsburgh, PA, United States
| | - Giacomo Indiveri
- Institute of Neuroinformatics, University of Zurich and ETH Zurich, Zurich, Switzerland
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13
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Poty S, Mandleywala K, O'Neill E, Knight JC, Cornelissen B, Lewis JS. 89Zr-PET imaging of DNA double-strand breaks for the early monitoring of response following α- and β-particle radioimmunotherapy in a mouse model of pancreatic ductal adenocarcinoma. Theranostics 2020; 10:5802-5814. [PMID: 32483420 PMCID: PMC7255009 DOI: 10.7150/thno.44772] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 04/13/2020] [Indexed: 12/20/2022] Open
Abstract
Rationale: The evaluation of early treatment response is critical for patient prognosis and treatment planning. When the current methods rely on invasive protocols that evaluate the expression of DNA damage markers on patient biopsy samples, we aim to evaluate a non-invasive PET imaging approach to monitor the early expression of the phosphorylated histone γH2AX in the context of pancreatic cancer targeted radionuclide therapy. Pancreatic ductal adenocarcinoma has a poor patient prognosis due to the absence of curative treatment for patients with advanced disease. There is therefore a critical need for the fast clinical translation of new therapeutic options. In line with these observations, our group has been focusing on the development of radiotheranostic agents based on a fully human monoclonal antibody (5B1) with exceptional affinity for CA19.9, an antigen overexpressed in PDAC. Two on-going clinical trials resulted from these efforts, one with 89Zr (diagnosis) and one with 177Lu (β-particle therapy). More recently, we successfully developed and evaluated in PDAC mouse models a targeted α-therapy strategy with high clinical translation potential. We aim to expedite the clinical translation of the developed radioimmunotherapy approaches by investigating the early therapeutic response and effect of radiation therapy in a PDAC mouse model via PET imaging. Methods: Mice bearing BxPC3 tumor xenografts were treated with α- and β-particle pretargeted radioimmunotherapy (PRIT), external beam radiotherapy (EBRT), or sham-treated (vehicle). The phosphorylated histone γH2AX produced as a response to DNA double strand breaks was quantified with the PET radiotracer, [89Zr]Zr-DFO-anti-γH2AX-TAT. Results: PET imaging studies in BxPC3 PDAC mouse models demonstrated increased uptake of [89Zr]Zr-DFO-anti-γH2AX-TAT (6.29 ± 0.15 %IA/g) following β-PRIT in BxPC3 PDAC xenografts as compared to the saline control group (4.58 ± 0.76 %IA/g) and EBRT control group (5.93 ± 0.76 %IA/g). Similarly, significantly higher uptake of [89Zr]Zr-DFO-anti-γH2AX-TAT was observed in tumors of the 225Ac-PRIT and EBRT (10 Gy) cohorts (7.37 ± 1.23 and 6.80 ± 1.24 %IA/g, respectively) compared to the negative control cohort (5.08 ± 0.95 %IA/g). Ex vivo γH2AX immunohistochemistry and immunofluorescence analysis correlated with in vivo89Zr-anti-γH2AX PET/CT imaging with increased γH2AX positive cell and γH2AX foci per cell in the treated cohorts. When α-PRIT resulted in prolonged overall survival of treated animals (107.5 days) as compared to β-PRIT (73.0 days), no evidence of difference in [89Zr]Zr-DFO-anti-γH2AX-TAT uptake at the tumor site was observed, highlighting that DNA damage is not the sole radiobiology paradigm and that off-targeted (bystander) effects should be considered. Conclusions: PET imaging studies with [89Zr]Zr-DFO-anti-γH2AX-TAT following α- and β-particle PRIT in a BxPC3 PDAC subcutaneous xenograft mouse model allowed the monitoring of tumor radiobiological response to treatment.
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MESH Headings
- Alpha Particles/therapeutic use
- Animals
- Antigens, Tumor-Associated, Carbohydrate/analysis
- Beta Particles/therapeutic use
- Biomarkers, Pharmacological/analysis
- Carcinoma, Pancreatic Ductal/diagnostic imaging
- Carcinoma, Pancreatic Ductal/genetics
- Carcinoma, Pancreatic Ductal/radiotherapy
- Cell Line, Tumor
- DNA/genetics
- DNA Breaks, Double-Stranded
- DNA Damage/genetics
- Disease Models, Animal
- Female
- Mice
- Mice, Nude
- Pancreatic Neoplasms/pathology
- Positron Emission Tomography Computed Tomography/methods
- Positron-Emission Tomography/methods
- Radioimmunotherapy/methods
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Sophie Poty
- Department of Radiology, Memorial Sloan Kettering Cancer Center, NY, USA
| | - Komal Mandleywala
- Department of Radiology, Memorial Sloan Kettering Cancer Center, NY, USA
| | - Edward O'Neill
- CRUK/MRC Oxford Institute of Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK
| | - James C. Knight
- CRUK/MRC Oxford Institute of Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Bart Cornelissen
- CRUK/MRC Oxford Institute of Radiation Oncology, Department of Oncology, University of Oxford, Oxford, UK
| | - Jason S. Lewis
- Department of Radiology, Memorial Sloan Kettering Cancer Center, NY, USA
- Radiochemistry and Molecular Imaging Probes Core, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Weill Cornell Medical College, New York, NY, USA
- Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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14
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Marculescu C, Lakshminarayanan A, Gault J, Knight JC, Folkes LK, Spink T, Robinson CV, Vallis K, Davis BG, Cornelissen B. Probing the limits of Q-tag bioconjugation of antibodies. Chem Commun (Camb) 2019; 55:11342-11345. [PMID: 31479092 PMCID: PMC6788405 DOI: 10.1039/c9cc02303h] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 07/25/2019] [Indexed: 12/25/2022]
Abstract
Site-selective labelling of antibodies (Abs) can circumvent problems from heterogeneity of conventional conjugation. Here, we evaluate the industrially-applied chemoenzymatic 'Q-tag' strategy based on transglutaminase-mediated (TGase) amide-bond formation in the generation of 89Zr-radiolabelled antibody conjugates. We show that, despite previously suggested high regioselectivity of TGases, in the anti-Her2 Ab Herceptin™ more precise native MS indicates only 70-80% functionalization at the target site (Q298H), in competition with modification at other sites, such as Q3H critically close to the CDR1 region.
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Affiliation(s)
- Cristina Marculescu
- CRUK/MRC Oxford Institute for Radiation Oncology
, Department of Oncology, University of Oxford
,
Oxford
, OX3 7DQ
, UK
.
;
- Chemistry Research Laboratory
, University of Oxford
,
Oxford
, OX1 3TA
, UK
.
| | - Abirami Lakshminarayanan
- CRUK/MRC Oxford Institute for Radiation Oncology
, Department of Oncology, University of Oxford
,
Oxford
, OX3 7DQ
, UK
.
;
- Chemistry Research Laboratory
, University of Oxford
,
Oxford
, OX1 3TA
, UK
.
| | - Joseph Gault
- Chemistry Research Laboratory
, University of Oxford
,
Oxford
, OX1 3TA
, UK
.
| | - James C. Knight
- CRUK/MRC Oxford Institute for Radiation Oncology
, Department of Oncology, University of Oxford
,
Oxford
, OX3 7DQ
, UK
.
;
| | - Lisa K. Folkes
- CRUK/MRC Oxford Institute for Radiation Oncology
, Department of Oncology, University of Oxford
,
Oxford
, OX3 7DQ
, UK
.
;
| | - Thomas Spink
- CRUK/MRC Oxford Institute for Radiation Oncology
, Department of Oncology, University of Oxford
,
Oxford
, OX3 7DQ
, UK
.
;
| | - Carol V. Robinson
- Chemistry Research Laboratory
, University of Oxford
,
Oxford
, OX1 3TA
, UK
.
| | - Katherine Vallis
- CRUK/MRC Oxford Institute for Radiation Oncology
, Department of Oncology, University of Oxford
,
Oxford
, OX3 7DQ
, UK
.
;
| | - Benjamin G. Davis
- Chemistry Research Laboratory
, University of Oxford
,
Oxford
, OX1 3TA
, UK
.
| | - Bart Cornelissen
- CRUK/MRC Oxford Institute for Radiation Oncology
, Department of Oncology, University of Oxford
,
Oxford
, OX3 7DQ
, UK
.
;
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15
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Knight JC, Mosley MJ, Kersemans V, Dias GM, Allen PD, Smart S, Cornelissen B. Dual-isotope imaging allows in vivo immunohistochemistry using radiolabelled antibodies in tumours. Nucl Med Biol 2019; 70:14-22. [PMID: 30825614 PMCID: PMC6599172 DOI: 10.1016/j.nucmedbio.2019.01.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 01/23/2019] [Accepted: 01/30/2019] [Indexed: 01/18/2023]
Abstract
While radiolabelled antibodies have found great utility as PET and SPECT imaging agents in oncological investigations, a notable shortcoming of these agents is their propensity to accumulate non-specifically within tumour tissue. The degree of this non-specific contribution to overall tumour uptake is highly variable and can ultimately lead to false conclusions. Therefore, in an effort to obtain a reliable measure of inter-individual differences in non-specific tumour uptake of radiolabelled antibodies, we demonstrate that the use of dual-isotope imaging overcomes this issue, enables true quantification of epitope expression levels, and allows non-invasive in vivo immunohistochemistry. The approach involves co-administration of (i) an antigen-targeting antibody labelled with zirconium-89 (89Zr), and (ii) an isotype-matched non-specific control IgG antibody labelled with indium-111 (111In). As an example, the anti-HER2 antibody trastuzumab was radiolabelled with 89Zr, and co-administered intravenously together with its 111In-labelled non-specific counterpart to mice bearing human breast cancer xenografts with differing HER2 expression levels (MDA-MB-468 [HER2-negative], MDA-MB-231 [low-HER2], MDA-MB-231/H2N [medium-HER2], and SKBR3 [high-HER2]). Simultaneous PET/SPECT imaging using a MILabs Vector4 small animal scanner revealed stark differences in the intratumoural distribution of [89Zr]Zr-trastuzumab and [111In]In-IgG, highlighting regions of HER2-mediated uptake and non-specific uptake, respectively. Normalisation of the tumour uptake values and tumour-to-blood ratios obtained with [89Zr]Zr-trastuzumab against those obtained with [111In]In-IgG yielded values which were most strongly correlated (R = 0.94; P = 0.02) with HER2 expression levels for each breast cancer type determined by Western blot and in vitro saturation binding assays, but not non-normalised uptake values. Normalised intratumoural distribution of [89Zr]Zr-trastuzumab correlated well with intratumoural heterogeneity HER2 expression.
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Affiliation(s)
- James C Knight
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Michael J Mosley
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Veerle Kersemans
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Gemma M Dias
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - P Danny Allen
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Sean Smart
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Bart Cornelissen
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom.
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16
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Knight JC, Nowotny T. GPUs Outperform Current HPC and Neuromorphic Solutions in Terms of Speed and Energy When Simulating a Highly-Connected Cortical Model. Front Neurosci 2018; 12:941. [PMID: 30618570 PMCID: PMC6299048 DOI: 10.3389/fnins.2018.00941] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 11/29/2018] [Indexed: 11/15/2022] Open
Abstract
While neuromorphic systems may be the ultimate platform for deploying spiking neural networks (SNNs), their distributed nature and optimization for specific types of models makes them unwieldy tools for developing them. Instead, SNN models tend to be developed and simulated on computers or clusters of computers with standard von Neumann CPU architectures. Over the last decade, as well as becoming a common fixture in many workstations, NVIDIA GPU accelerators have entered the High Performance Computing field and are now used in 50 % of the Top 10 super computing sites worldwide. In this paper we use our GeNN code generator to re-implement two neo-cortex-inspired, circuit-scale, point neuron network models on GPU hardware. We verify the correctness of our GPU simulations against prior results obtained with NEST running on traditional HPC hardware and compare the performance with respect to speed and energy consumption against published data from CPU-based HPC and neuromorphic hardware. A full-scale model of a cortical column can be simulated at speeds approaching 0.5× real-time using a single NVIDIA Tesla V100 accelerator-faster than is currently possible using a CPU based cluster or the SpiNNaker neuromorphic system. In addition, we find that, across a range of GPU systems, the energy to solution as well as the energy per synaptic event of the microcircuit simulation is as much as 14× lower than either on SpiNNaker or in CPU-based simulations. Besides performance in terms of speed and energy consumption of the simulation, efficient initialization of models is also a crucial concern, particularly in a research context where repeated runs and parameter-space exploration are required. Therefore, we also introduce in this paper some of the novel parallel initialization methods implemented in the latest version of GeNN and demonstrate how they can enable further speed and energy advantages.
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Affiliation(s)
- James C. Knight
- Centre for Computational Neuroscience and Robotics, School of Engineering and Informatics, University of Sussex, Brighton, United Kingdom
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17
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Cornelissen B, Knight JC, Mukherjee S, Evangelista L, Xavier C, Caobelli F, Del Vecchio S, Rbah-Vidal L, Barbet J, de Jong M, van Leeuwen FWB. Translational molecular imaging in exocrine pancreatic cancer. Eur J Nucl Med Mol Imaging 2018; 45:2442-2455. [PMID: 30225616 PMCID: PMC6208802 DOI: 10.1007/s00259-018-4146-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 08/22/2018] [Indexed: 02/06/2023]
Abstract
Effective treatment for pancreatic cancer remains challenging, particularly the treatment of pancreatic ductal adenocarcinoma (PDAC), which makes up more than 95% of all pancreatic cancers. Late diagnosis and failure of chemotherapy and radiotherapy are all too common, and many patients die soon after diagnosis. Here, we make the case for the increased use of molecular imaging in PDAC preclinical research and in patient management.
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Affiliation(s)
- Bart Cornelissen
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, Oxford University, Oxford, UK.
| | - James C Knight
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, Oxford University, Oxford, UK
| | - Somnath Mukherjee
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, Oxford University, Oxford, UK
| | | | | | - Federico Caobelli
- Department of Radiology, Universitätsspital Basel, Basel, Switzerland
| | | | - Latifa Rbah-Vidal
- CRCINA, INSERM, CNRS, Université d'Angers, Université de Nantes, Nantes, France
| | - Jacques Barbet
- CRCINA, INSERM, CNRS, Université d'Angers, Université de Nantes, Nantes, France
| | - Marion de Jong
- Department of Radiology & Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Fijs W B van Leeuwen
- Interventional Molecular Imaging Laboratory, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
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18
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Abstract
We present a coherent fiber bundle comprising over 11,000 doped silica cores separated by an air-filled cladding. The fiber is characterized, and its imaging quality is shown to be a substantial improvement over the commercial state of the art, with comparable resolution over an unparalleled spectral range.
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19
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Torres JB, Knight JC, Mosley MJ, Kersemans V, Koustoulidou S, Allen D, Kinchesh P, Smart S, Cornelissen B. Imaging of Claudin-4 in Pancreatic Ductal Adenocarcinoma Using a Radiolabelled Anti-Claudin-4 Monoclonal Antibody. Mol Imaging Biol 2018; 20:292-299. [PMID: 28842811 PMCID: PMC5862916 DOI: 10.1007/s11307-017-1112-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
PURPOSE Despite its widespread use, the positron emission tomography (PET) radiotracer 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) has been shown in clinical settings to be ineffective for improving early diagnosis of pancreatic ductal adenocarcinoma (PDAC). A promising biomarker for PDAC detection is the tight junction protein claudin-4. The purpose of this study was to evaluate a new single-photon emission computed tomography (SPECT) imaging agent, [111In]anti-claudin-4 mAb, with regard to its ability to allow visualisation of claudin-4 in a xenograft and a genetically engineered mouse model of PDAC. PROCEDURES The ability of [111In]anti-claudin-4 mAb to selectively target claudin-4 was assessed using two human xenograft tumour models with differential claudin-4 status in mice. [111In]anti-claudin-4 mAb was also used to detect PDAC development in genetically engineered KPC mice. The PDAC status of these mice was confirmed with [18F]FDG-PET, magnetic resonance imaging (MRI), histology, and immunofluorescence microscopy. RESULTS High uptake of [111In]anti-claudin-4 mAb was observed in PDAC xenografts in mice, reaching 16.9 ± 4.5 % of injected dose per gram (% ID/g) at 72 h post-injection. This uptake was mediated specifically by the expression of claudin-4. Uptake of [111In]anti-claudin-4 mAb also enabled clear visualisation of spontaneous PDAC formation in KPC mice. CONCLUSIONS [111In]anti-claudin-4 mAb allows non-invasive detection of claudin-4 upregulation during development of PDAC and could potentially be used to aid in the early detection and characterisation of this malignancy.
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Affiliation(s)
- Julia Baguña Torres
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - James C Knight
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Michael J Mosley
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Veerle Kersemans
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Sofia Koustoulidou
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Danny Allen
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Paul Kinchesh
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Sean Smart
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Bart Cornelissen
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7DQ, UK.
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20
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Abstract
SpiNNaker is a digital neuromorphic architecture, designed specifically for the low power simulation of large-scale spiking neural networks at speeds close to biological real-time. Unlike other neuromorphic systems, SpiNNaker allows users to develop their own neuron and synapse models as well as specify arbitrary connectivity. As a result SpiNNaker has proved to be a powerful tool for studying different neuron models as well as synaptic plasticity—believed to be one of the main mechanisms behind learning and memory in the brain. A number of Spike-Timing-Dependent-Plasticity(STDP) rules have already been implemented on SpiNNaker and have been shown to be capable of solving various learning tasks in real-time. However, while STDP is an important biological theory of learning, it is a form of Hebbian or unsupervised learning and therefore does not explain behaviors that depend on feedback from the environment. Instead, learning rules based on neuromodulated STDP (three-factor learning rules) have been shown to be capable of solving reinforcement learning tasks in a biologically plausible manner. In this paper we demonstrate for the first time how a model of three-factor STDP, with the third-factor representing spikes from dopaminergic neurons, can be implemented on the SpiNNaker neuromorphic system. Using this learning rule we first show how reward and punishment signals can be delivered to a single synapse before going on to demonstrate it in a larger network which solves the credit assignment problem in a Pavlovian conditioning experiment. Because of its extra complexity, we find that our three-factor learning rule requires approximately 2× as much processing time as the existing SpiNNaker STDP learning rules. However, we show that it is still possible to run our Pavlovian conditioning model with up to 1 × 104 neurons in real-time, opening up new research opportunities for modeling behavioral learning on SpiNNaker.
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Affiliation(s)
- Mantas Mikaitis
- Advanced Processor Technologies, Faculty of Science and Engineering, School of Computer Science, University of Manchester, Manchester, United Kingdom
| | - Garibaldi Pineda García
- Advanced Processor Technologies, Faculty of Science and Engineering, School of Computer Science, University of Manchester, Manchester, United Kingdom
| | - James C Knight
- Centre for Computational Neuroscience and Robotics, School of Engineering and Informatics, University of Sussex, Brighton, United Kingdom
| | - Steve B Furber
- Advanced Processor Technologies, Faculty of Science and Engineering, School of Computer Science, University of Manchester, Manchester, United Kingdom
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21
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Knight JC, Mosley MJ, Bravo LC, Kersemans V, Allen PD, Mukherjee S, O'Neill E, Cornelissen B. 89Zr-anti-γH2AX-TAT but not 18F-FDG Allows Early Monitoring of Response to Chemotherapy in a Mouse Model of Pancreatic Ductal Adenocarcinoma. Clin Cancer Res 2017; 23:6498-6504. [PMID: 28774899 DOI: 10.1158/1078-0432.ccr-17-0664] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 06/14/2017] [Accepted: 07/24/2017] [Indexed: 11/16/2022]
Abstract
Purpose: Late-stage, unresectable pancreatic ductal adenocarcinoma (PDAC) is largely resistant to chemotherapy and consequently has a very poor 5-year survival rate of <5%. The ability to assess the efficacy of a treatment soon after its initiation would enable rapid switching to potentially more effective therapies if the current treatment is found to be futile. We have evaluated the ability of the PET imaging agent, 89Zr-anti-γH2AX-TAT, to monitor DNA damage in response to fluorouracil (5-FU), gemcitabine, or capecitabine treatment in a mouse model of pancreatic cancer. We have also compared the utility of this approach against the standard clinical PET radiotracer, 18F-FDG.Experimental Design: C57BL/6 mice bearing subcutaneous pancreatic cancer (KPC; B8484) allografts were treated with 5-FU, gemcitabine, or capecitabine. Therapeutic response was monitored by PET and ex vivo biodistribution experiments using either 89Zr-anti-γH2AX-TAT or 18F-FDG as imaging agents. To further examine the effect of therapeutic response upon uptake of these imaging agents, IHC analysis of harvested tumor allograft tissue was also performed.Results: Accumulation of 89Zr-anti-γH2AX-TAT in the tumors of mice that received chemotherapy was higher compared with vehicle-treated mice and was shown to be specifically mediated by γH2AX. In contrast, 18F-FDG did not provide useful indications of therapeutic response.Conclusions:89Zr-anti-γH2AX-TAT has shown a superior ability to monitor early therapeutic responses to chemotherapy by PET imaging compared with 18F-FDG in an allograft model of PDAC in mice. Clin Cancer Res; 23(21); 6498-504. ©2017 AACR.
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Affiliation(s)
- James C Knight
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Michael J Mosley
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Luisa Contreras Bravo
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Veerle Kersemans
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - P Danny Allen
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Somnath Mukherjee
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Eric O'Neill
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Bart Cornelissen
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom.
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22
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Abstract
DNA integrity is constantly challenged by endogenous and exogenous factors that can alter the DNA sequence, leading to mutagenesis, aberrant transcriptional activity, and cytotoxicity. Left unrepaired, damaged DNA can ultimately lead to the development of cancer. To overcome this threat, a series of complex mechanisms collectively known as the DNA damage response (DDR) are able to detect the various types of DNA damage that can occur and stimulate the appropriate repair process. Each DNA damage repair pathway leads to the recruitment, upregulation, or activation of specific proteins within the nucleus, which, in some cases, can represent attractive targets for molecular imaging. Given the well-established involvement of DDR during tumorigenesis and cancer therapy, the ability to monitor these repair processes non-invasively using nuclear imaging techniques may facilitate the earlier detection of cancer and may also assist in monitoring response to DNA damaging treatment. This review article aims to provide an overview of recent efforts to develop PET and SPECT radiotracers for imaging of DNA damage repair proteins.
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Affiliation(s)
- James C Knight
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7LJ, UK
| | - Sofia Koustoulidou
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7LJ, UK
| | - Bart Cornelissen
- CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7LJ, UK.
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23
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Knight JC, Tenbrink E, Sheng J, Patil AS. Anterior uterocervical angle measurement improves prediction of cerclage failure. J Perinatol 2017; 37:375-379. [PMID: 28055026 DOI: 10.1038/jp.2016.241] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 11/07/2016] [Accepted: 11/14/2016] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To compare the anterior uterocervical angle and cervical length as predictors of spontaneous preterm delivery in patients with transvaginal cerclage. STUDY DESIGN We retrospectively evaluated a cohort of 142 pregnant women with transvaginal cerclage placed over a 5-year period (2010 to 2015) were evaluated. Cervical morphology characteristics were measured from endovaginal imaging, including cervical length, cerclage height, funnel volume and anterior uterocervical angle prior to cerclage placement (UCA 1), shortly after cerclage placement (UCA 2) and the last image prior to delivery (UCA 3). Cerclage failure was defined as delivery prior to 36 weeks. Univariate analysis, receiver operator characteristic curves and binary logistic regression were used for statistical analysis. Statistical significance was defined as a P<0.05. RESULTS Among the 142 women with a transvaginal cerclage, 38% had cerclage failure. The mean gestational age at birth was 29.3±5.2 weeks in the failure group compared with 37.9±2.8 weeks in those that did not fail (P<0.001). Univariate analysis identified cervical length (P=0.034) and UCA 3 (P<0.001) as significantly associated with gestational age at birth. Receiver operator characteristic curves demonstrated improved prediction of delivery prior to 34 weeks at UCA 3=108o (97% sensitivity, 65% specificity) compared to a cervical length of 25 mm. At <28 weeks, optimal performance of UCA 3 was found at 112o (100% sensitivity, 62% specificity) compared with cervical length of 25 mm (29% sensitivity, 39% specificity). Binary logistic regression revealed UCA 3>108o conferred an OR 35.1 (95% CI 7.7 to 160.3) for delivery prior to 34 weeks, and UCA 3>112o an OR 42.0 (95% CI 5.3 to 332.1) for delivery prior to 28 weeks. In comparison, CL<25 mm had an OR 4.7 (95% CI 1.8 to 12.2) for delivery prior to 34 weeks and OR 6.0 (95% CI 1.9 to 19.3) prior to 28 weeks. CONCLUSIONS In patients with transvaginal cerclage, an increasingly obtuse anterior uterocervical angle reflects an increased risk of cerclage failure in the mid-trimester. Utilization of UCA measurement as a surveillance tool may improve identification of patients at risk for cerclage failure.
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Affiliation(s)
- J C Knight
- Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - E Tenbrink
- Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - J Sheng
- Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - A S Patil
- Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Indiana University School of Medicine, Indianapolis, IN, USA.,Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
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24
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Holt RJ, Vandiedonck C, Willis-Owen SA, Knight JC, Cookson WO, Moffatt MF, Zhang Y. Erratum: A functional AT/G polymorphism in the 5′-untranslated region of SETDB2 in the IgE locus on human chromosome 13q14. Genes Immun 2017; 18:57. [PMID: 27170559 PMCID: PMC5303759 DOI: 10.1038/gene.2016.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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25
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Chen L, Al-Mossawi MH, Ridley A, Sekine T, Hammitzsch A, de Wit J, Simone D, Shi H, Penkava F, Kurowska-Stolarska M, Pulyakhina I, Knight JC, Kim TJ, Bowness P. miR-10b-5p is a novel Th17 regulator present in Th17 cells from ankylosing spondylitis. Ann Rheum Dis 2016; 76:620-625. [PMID: 28039186 DOI: 10.1136/annrheumdis-2016-210175] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 11/28/2016] [Accepted: 12/03/2016] [Indexed: 12/24/2022]
Abstract
OBJECTIVE To determine the microRNA (miR) signature in ankylosing spondylitis (AS) T helper (Th)17 cells. METHODS Interleukin (IL)-17A-producing CD4+ T cells from patients with AS and healthy controls were FACS-sorted for miR sequencing and qPCR validation. miR-10b function was determined by miR mimic expression followed by cytokine measurement, transcriptome analysis, qPCR and luciferase assays. RESULTS AS Th17 cells exhibited a miR signature characterised by upregulation of miR-155-5p, miR-210-3p and miR-10b. miR-10b has not been described previously in Th17 cells and was selected for further characterisation. miR-10b is transiently induced in in vitro differentiated Th17 cells. Transcriptome, qPCR and luciferase assays suggest that MAP3K7 is targeted by miR-10b. Both miR-10b overexpression and MAP3K7 silencing inhibited production of IL-17A by both total CD4 and differentiating Th17 cells. CONCLUSIONS AS Th17 cells have a specific miR signature and upregulate miR-10b in vitro. Our data suggest that miR-10b is upregulated by proinflammatory cytokines and may act as a feedback loop to suppress IL-17A by targeting MAP3K7. miR-10b is a potential therapeutic candidate to suppress pathogenic Th17 cell function in patients with AS.
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Affiliation(s)
- L Chen
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - M H Al-Mossawi
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - A Ridley
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - T Sekine
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - A Hammitzsch
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK.,Department of Nephrology, Klinikum rechts der lsar, Technical University of Munich, Munich, Germany
| | - J de Wit
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - D Simone
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - H Shi
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - F Penkava
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - M Kurowska-Stolarska
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - I Pulyakhina
- Wellcome Trust Centre for Human Genetics, Oxford, UK
| | - J C Knight
- Nuffield Department of Medicine, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - T J Kim
- Department of Rheumatology, Medical School and Hospital, Chonnam National University, Gwangju, Republic of Korea
| | - P Bowness
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK.,National Institute for Health Research Oxford Musculoskeletal Biomedical Research Unit, Oxford, UK
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26
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Abstract
While the adult human brain has approximately 8.8 × 10(10) neurons, this number is dwarfed by its 1 × 10(15) synapses. From the point of view of neuromorphic engineering and neural simulation in general this makes the simulation of these synapses a particularly complex problem. SpiNNaker is a digital, neuromorphic architecture designed for simulating large-scale spiking neural networks at speeds close to biological real-time. Current solutions for simulating spiking neural networks on SpiNNaker are heavily inspired by work on distributed high-performance computing. However, while SpiNNaker shares many characteristics with such distributed systems, its component nodes have much more limited resources and, as the system lacks global synchronization, the computation performed on each node must complete within a fixed time step. We first analyze the performance of the current SpiNNaker neural simulation software and identify several problems that occur when it is used to simulate networks of the type often used to model the cortex which contain large numbers of sparsely connected synapses. We then present a new, more flexible approach for mapping the simulation of such networks to SpiNNaker which solves many of these problems. Finally we analyze the performance of our new approach using both benchmarks, designed to represent cortical connectivity, and larger, functional cortical models. In a benchmark network where neurons receive input from 8000 STDP synapses, our new approach allows 4× more neurons to be simulated on each SpiNNaker core than has been previously possible. We also demonstrate that the largest plastic neural network previously simulated on neuromorphic hardware can be run in real time using our new approach: double the speed that was previously achieved. Additionally this network contains two types of plastic synapse which previously had to be trained separately but, using our new approach, can be trained simultaneously.
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Affiliation(s)
- James C Knight
- Advanced Processor Technologies Group, School of Computer Science, University of Manchester Manchester, UK
| | - Steve B Furber
- Advanced Processor Technologies Group, School of Computer Science, University of Manchester Manchester, UK
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27
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Lai C, Chen J, Knight JC, Manthiram A, Navrotsky A. Inside Cover: Thermodynamic Stability of Transition-Metal-Substituted LiMn 2−xM xO 4(M=Cr, Fe, Co, and Ni) Spinels (ChemPhysChem 13/2016). Chemphyschem 2016. [DOI: 10.1002/cphc.201600585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Chenying Lai
- Peter A. Rock Thermochemistry Laboratory and NEAT ORU; University of California Davis; One Shields Ave. Davis CA 95616 USA
| | - Jiewei Chen
- Peter A. Rock Thermochemistry Laboratory and NEAT ORU; University of California Davis; One Shields Ave. Davis CA 95616 USA
| | - James C. Knight
- McKetta Department of Chemical Engineering; University of Texas at Austin; 200 E. Dean Keeton St. Stop C0400 Austin TX 78712 USA
| | - Arumugam Manthiram
- McKetta Department of Chemical Engineering; University of Texas at Austin; 200 E. Dean Keeton St. Stop C0400 Austin TX 78712 USA
| | - Alexandra Navrotsky
- Peter A. Rock Thermochemistry Laboratory and NEAT ORU; University of California Davis; One Shields Ave. Davis CA 95616 USA
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28
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Knight JC, Amoroso AJ, Edwards PG, Singh N, Ward BD. Shaping and enforcing coordination spheres: probing the ability of tripodal ligands to favour trigonal prismatic geometry. Dalton Trans 2016; 45:10630-42. [PMID: 27273116 DOI: 10.1039/c6dt01165a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report two tripodal frameworks, mono(2,2'-bipyrid-6-yl)bis(2-pyridyl)methanol () and bis(2,2'-bipyrid-6-yl)mono(2-pyridyl)methanol () which have one and two bipyridyl arms, respectively. Both ligands form complexes with the first row transition metals. Both ligands appear to overcome the steric strain involved in twisting the ligand to produce an octahedral complex and the solid state structures in general show more octahedral character than complexes of the related ligand, tris(2,2'-bipyrid-6-yl)methanol (). Continuous Shape Mapping (CShM) calculations based on crystallographic data reveal that is incapable of enforcing a trigonal prismatic (TP) co-ordination geometry in the solid state, surprisingly even upon co-ordination to metals with no stereochemical preference such as cadmium (S(TP) = 7.15 and S(Oh) = 3.95). However, ligand clearly maintains an ability to enforce a trigonal prismatic conformation which is demonstrated in the crystal structures of the Mn(II) and Cd(II) complexes (S(TP) = 0.75 and 1.09, respectively). While maintains near-TP configurations in the presence of metal ions with strong octahedral preferences, distorts towards predominantly octahedral co-ordination geometries, increasing in the order Co(II) < Ni(II) < Fe(II) and no trigonal prismatic structures.
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Affiliation(s)
- James C Knight
- School of Chemistry, Cardiff University, Cardiff, South Glamorgan.
| | - Angelo J Amoroso
- School of Chemistry, Cardiff University, Cardiff, South Glamorgan.
| | - Peter G Edwards
- School of Chemistry, Cardiff University, Cardiff, South Glamorgan.
| | - Neha Singh
- School of Chemistry, Cardiff University, Cardiff, South Glamorgan.
| | - Benjamin D Ward
- School of Chemistry, Cardiff University, Cardiff, South Glamorgan.
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29
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Saad FA, Knight JC, Kariuki BM, Amoroso AJ. Co-ordination behaviour of a novel tristhiourea tripodal ligand; structural variations in a series of transition metal complexes. Dalton Trans 2016; 45:10280-8. [PMID: 27240882 DOI: 10.1039/c6dt01148a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The co-ordination chemistry of a tristhiourea tris(2-pyridylmethyl)amine ligand () with a series of transition metal ions has been investigated. Crystallographic data show that large metal ions, with no geometrical preferences, such as Mn(ii) and Cd(ii), will form seven co-ordinate monocapped octahedral complexes, while smaller metal ions such as Zn(ii) favour five co-ordinate trigonal bipyramidal structures. In a similar manner to the related bisthiourea complexes, the Ni(ii) complex shows a strong preference for octahedral geometries resulting in the ligand binding asymmetrically. Spectroscopic (IR and NMR), spectrometric (MS) as well as electrochemical data for these complexes are reported.
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Affiliation(s)
- Fawaz A Saad
- Umm Al-Qura University, Kingdom of Saudi Arabia. and School of Chemistry, Cardiff University, Cardiff, UK.
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30
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Knight JC, Paisey SJ, Dabkowski AM, Marculescu C, Williams AS, Marshall C, Cornelissen B. Scaling-down antibody radiolabeling reactions with zirconium-89. Dalton Trans 2016; 45:6343-7. [PMID: 26986633 DOI: 10.1039/c5dt04774a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2024]
Abstract
The most widely cited procedures for radiolabeling antibodies with zirconium-89 for immuno-PET require multi-milligram amounts of antibody which can be cost-prohibitive, particularly during the research and development process. We therefore sought to develop a reliable (89)Zr-radiolabeling procedure that provides high radiochemical yields at the microgram scale.
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Affiliation(s)
- James C Knight
- CR-UK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, OX3 7LJ, UK
| | - Stephen J Paisey
- Wales Research & Diagnostic PET Imaging Centre (PETIC), Institute for Translation, Innovation, Methodology & Engagement (TIME), School of Medicine, Heath Park, Cardiff University, Cardiff, Wales, UK
| | - Adam M Dabkowski
- Wales Research & Diagnostic PET Imaging Centre (PETIC), Institute for Translation, Innovation, Methodology & Engagement (TIME), School of Medicine, Heath Park, Cardiff University, Cardiff, Wales, UK
| | - Cristina Marculescu
- CR-UK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, OX3 7LJ, UK
| | - Anwen S Williams
- Institute of infection and immunity, School of Medicine, Heath Park, Cardiff University, Cardiff, Wales, UK
| | - Christopher Marshall
- Wales Research & Diagnostic PET Imaging Centre (PETIC), Institute for Translation, Innovation, Methodology & Engagement (TIME), School of Medicine, Heath Park, Cardiff University, Cardiff, Wales, UK
| | - Bart Cornelissen
- CR-UK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, OX3 7LJ, UK
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31
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Knight JC, Tully PJ, Kaplan BA, Lansner A, Furber SB. Large-Scale Simulations of Plastic Neural Networks on Neuromorphic Hardware. Front Neuroanat 2016; 10:37. [PMID: 27092061 PMCID: PMC4823276 DOI: 10.3389/fnana.2016.00037] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 03/18/2016] [Indexed: 11/17/2022] Open
Abstract
SpiNNaker is a digital, neuromorphic architecture designed for simulating large-scale spiking neural networks at speeds close to biological real-time. Rather than using bespoke analog or digital hardware, the basic computational unit of a SpiNNaker system is a general-purpose ARM processor, allowing it to be programmed to simulate a wide variety of neuron and synapse models. This flexibility is particularly valuable in the study of biological plasticity phenomena. A recently proposed learning rule based on the Bayesian Confidence Propagation Neural Network (BCPNN) paradigm offers a generic framework for modeling the interaction of different plasticity mechanisms using spiking neurons. However, it can be computationally expensive to simulate large networks with BCPNN learning since it requires multiple state variables for each synapse, each of which needs to be updated every simulation time-step. We discuss the trade-offs in efficiency and accuracy involved in developing an event-based BCPNN implementation for SpiNNaker based on an analytical solution to the BCPNN equations, and detail the steps taken to fit this within the limited computational and memory resources of the SpiNNaker architecture. We demonstrate this learning rule by learning temporal sequences of neural activity within a recurrent attractor network which we simulate at scales of up to 2.0 × 104 neurons and 5.1 × 107 plastic synapses: the largest plastic neural network ever to be simulated on neuromorphic hardware. We also run a comparable simulation on a Cray XC-30 supercomputer system and find that, if it is to match the run-time of our SpiNNaker simulation, the super computer system uses approximately 45× more power. This suggests that cheaper, more power efficient neuromorphic systems are becoming useful discovery tools in the study of plasticity in large-scale brain models.
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Affiliation(s)
- James C Knight
- Advanced Processor Technologies Group, School of Computer Science, University of Manchester Manchester, UK
| | - Philip J Tully
- Department of Computational Biology, Royal Institute of TechnologyStockholm, Sweden; Stockholm Brain Institute, Karolinska InstituteStockholm, Sweden; Institute for Adaptive and Neural Computation, School of Informatics, University of EdinburghEdinburgh, UK
| | - Bernhard A Kaplan
- Department of Visualization and Data Analysis, Zuse Institute Berlin Berlin, Germany
| | - Anders Lansner
- Department of Computational Biology, Royal Institute of TechnologyStockholm, Sweden; Stockholm Brain Institute, Karolinska InstituteStockholm, Sweden; Department of Numerical analysis and Computer Science, Stockholm UniversityStockholm, Sweden
| | - Steve B Furber
- Advanced Processor Technologies Group, School of Computer Science, University of Manchester Manchester, UK
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32
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Lai C, Chen J, Knight JC, Manthiram A, Navrotsky A. Thermodynamic Stability of Transition‐Metal‐Substituted LiMn
2−
x
M
x
O
4
(M=Cr, Fe, Co, and Ni) Spinels. Chemphyschem 2016; 17:1973-8. [DOI: 10.1002/cphc.201600120] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Chenying Lai
- Peter A. Rock Thermochemistry Laboratory and NEAT ORU University of California Davis One Shields Ave. Davis CA 95616 USA
| | - Jiewei Chen
- Peter A. Rock Thermochemistry Laboratory and NEAT ORU University of California Davis One Shields Ave. Davis CA 95616 USA
| | - James C. Knight
- McKetta Department of Chemical Engineering University of Texas at Austin 200 E. Dean Keeton St. Stop C0400 Austin TX 78712 USA
| | - Arumugam Manthiram
- McKetta Department of Chemical Engineering University of Texas at Austin 200 E. Dean Keeton St. Stop C0400 Austin TX 78712 USA
| | - Alexandra Navrotsky
- Peter A. Rock Thermochemistry Laboratory and NEAT ORU University of California Davis One Shields Ave. Davis CA 95616 USA
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33
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Dhalla F, Fox H, Davenport EE, Sadler R, Anzilotti C, van Schouwenburg PA, Ferry B, Chapel H, Knight JC, Patel SY. Chronic mucocutaneous candidiasis: characterization of a family with STAT-1 gain-of-function and development of an ex-vivo assay for Th17 deficiency of diagnostic utility. Clin Exp Immunol 2016; 184:216-27. [PMID: 26621323 PMCID: PMC4837241 DOI: 10.1111/cei.12746] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 11/02/2015] [Accepted: 11/25/2015] [Indexed: 01/30/2023] Open
Abstract
Chronic mucocutaneous candidiasis (CMC) is characterized by recurrent and persistent superficial infections, with Candida albicans affecting the mucous membranes, skin and nails. It can be acquired or caused by primary immune deficiencies, particularly those that impair interleukin (IL)−17 and IL‐22 immunity. We describe a single kindred with CMC and the identification of a STAT1 GOF mutation by whole exome sequencing (WES). We show how detailed clinical and immunological phenotyping of this family in the context of WES has enabled revision of disease status and clinical management. Together with analysis of other CMC cases within our cohort of patients, we used knowledge arising from the characterization of this family to develop a rapid ex‐vivo screening assay for the detection of T helper type 17 (Th17) deficiency better suited to the routine diagnostic setting than established in‐vitro techniques, such as intracellular cytokine staining and enzyme‐linked immunosorbent assay (ELISA) using cell culture supernatants. We demonstrate that cell surface staining of unstimulated whole blood for CCR6+CXCR3–CCR4+CD161+ T helper cells generates results that correlate with intracellular cytokine staining for IL‐17A, and is able to discriminate between patients with molecularly defined CMC and healthy controls with 100% sensitivity and specificity within the cohort tested. Furthermore, removal of CCR4 and CD161 from the antibody staining panel did not affect assay performance, suggesting that the enumeration of CCR6+CXCR3–CD4+ T cells is sufficient for screening for Th17 deficiency in patients with CMC and could be used to guide further investigation aimed at identifying the underlying molecular cause.
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Affiliation(s)
- F Dhalla
- Department of Clinical Immunology, John Radcliffe Hospital, Oxford, UK
| | - H Fox
- Department of Clinical Laboratory Immunology, Churchill Hospital, Oxford, UK
| | - E E Davenport
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - R Sadler
- Department of Clinical Laboratory Immunology, Churchill Hospital, Oxford, UK
| | - C Anzilotti
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - P A van Schouwenburg
- NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - B Ferry
- Department of Clinical Laboratory Immunology, Churchill Hospital, Oxford, UK
| | - H Chapel
- Department of Clinical Immunology, John Radcliffe Hospital, Oxford, UK.,NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - J C Knight
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - S Y Patel
- Department of Clinical Immunology, John Radcliffe Hospital, Oxford, UK.,NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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34
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Sharma SK, Sevak KK, Monette S, Carlin SD, Knight JC, Wuest FR, Sala E, Zeglis BM, Lewis JS. Preclinical 89Zr Immuno-PET of High-Grade Serous Ovarian Cancer and Lymph Node Metastasis. J Nucl Med 2016; 57:771-6. [PMID: 26837339 DOI: 10.2967/jnumed.115.167072] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 01/07/2016] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED The elevation of cancer antigen 125 (CA125) levels in the serum of asymptomatic patients precedes the radiologic detection of high-grade serous ovarian cancer by at least 2 mo and the final clinical diagnosis by 5 mo. PET imaging of CA125 expression by ovarian cancer cells may enhance the evaluation of the extent of disease and provide a roadmap to surgery as well as detect recurrence and metastases. METHODS (89)Zr-labeled mAb-B43.13 was synthesized to target CA125 and evaluated via PET imaging and biodistribution studies in mice bearing OVCAR3 human ovarian adenocarcinoma xenografts. Ex vivo analysis of tumors and lymph nodes was performed via autoradiography, histopathology, and immunohistochemistry. RESULTS PET imaging using (89)Zr-DFO-mAb-B43.13 (DFO is desferrioxamine) clearly delineated CA125-positive OVCAR3 xenografts as early as 24 h after the administration of the radioimmunoconjugate. Biodistribution studies revealed accretion of (89)Zr-DFO-mAb-B43.13 in the OVCAR3 tumors, ultimately reaching 22.3 ± 6.3 percentage injected dose per gram (%ID/g) at 72 h after injection. Most interestingly, activity concentrations greater than 50 %ID/g were observed in the ipsilateral lymph nodes of the xenograft-bearing mice. Histopathologic analysis of the immuno-PET-positive lymph nodes revealed the presence of grossly metastasized ovarian cancer cells within the lymphoid tissues. In control experiments, only low-level, non-specific uptake of (89)Zr-labeled isotype IgG was observed in OVCAR3 tumors; similarly, low-activity concentrations of (89)Zr-DFO-mAb-B43.13 accumulated in CA125-negative SKOV3 tumors. CONCLUSION Immuno-PET with (89)Zr-labeled mAb-B43.13 is a potential strategy for the noninvasive delineation of extent of disease and may add value in treatment planning and treatment monitoring of high-grade serous ovarian cancer.
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Affiliation(s)
- Sai Kiran Sharma
- Department of Radiology and the Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Kuntal K Sevak
- Department of Radiology and the Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Sebastien Monette
- Tri-Institutional Laboratory of Comparative Pathology, Memorial Sloan Kettering Cancer Center, Weill Cornell Medical College, and The Rockefeller University, New York, New York
| | - Sean D Carlin
- Department of Radiology and the Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York
| | - James C Knight
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Frank R Wuest
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Evis Sala
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York; and
| | - Brian M Zeglis
- Department of Chemistry, Hunter College and the Graduate Center of the City University of New York, New York, New York
| | - Jason S Lewis
- Department of Radiology and the Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York, New York
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Owen HC, Torrance HDT, Barnes MR, Brohi K, Knight JC, Hinds CJ, O'Dwyer MJ. The Role of Micrornas in The Development of Hospital Acquired Infection in Polytrauma Patients. Intensive Care Med Exp 2015. [PMCID: PMC4796680 DOI: 10.1186/2197-425x-3-s1-a35] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Abstract
There is immense interest to develop Mg-ion batteries, but finding suitable cathode materials has been a challenge. The spinel structure has many advantages for ion insertion and has been successfully used in Li-ion batteries. We present here findings on the attempts to extract Mg from MgMn2O4-based spinels with acid (H2SO4) and with NO2BF4. The acid treatment was able to fully remove all Mg from MgMn2O4 by following a mechanism involving the disproportionation of Mn(3+), and the extraction rate decreased with increasing cation disorder. Samples with additional Mg(2+) ions in the octahedral sites (e.g., Mg1.1Mn1.9O4 and Mg1.5Mn1.5O4) also exhibit complete or near complete demagnesiation due to an additional mechanism involving ion exchange of Mg(2+) by H(+), but no Mg could be extracted from MgMnAlO4 due to the disruption of Mn-Mn interaction/contact across shared octahedral edges. In contrast, no Mg could be extracted with the oxidizing agent NO2BF4 from MgMn2O4 or Mg1.5Mn1.5O4 as the electrostatic repulsion between the divalent Mg(2+) ions prevents Mg(2+) diffusion through the 16c octahedral sites, unlike Li(+) diffusion, suggesting that spinels may not serve as potential hosts for Mg-ion batteries. The ability to extract Mg with acid in contrast to that with NO2BF4 is attributed to Mn dissolution from the lattice and the consequent reduction in electrostatic repulsion. The findings could provide insights toward the design of Mg hosts for Mg-ion batteries.
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Affiliation(s)
- James C Knight
- McKetta Department of Chemical Engineering, University of Texas at Austin , Austin, Texas 78712, United States
| | - Soosairaj Therese
- Materials Science and Engineering Program, University of Texas at Austin , Austin, Texas 78712, United States
- Department of Chemistry and Chemical Technology, Bronx Community College , Bronx, New York 10453, United States
| | - Arumugam Manthiram
- McKetta Department of Chemical Engineering, University of Texas at Austin , Austin, Texas 78712, United States
- Materials Science and Engineering Program, University of Texas at Austin , Austin, Texas 78712, United States
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Knight JC, Topping C, Mosley M, Kersemans V, Falzone N, Fernández-Varea JM, Cornelissen B. PET imaging of DNA damage using (89)Zr-labelled anti-γH2AX-TAT immunoconjugates. Eur J Nucl Med Mol Imaging 2015; 42:1707-1717. [PMID: 26031435 DOI: 10.1007/s00259-015-3092-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 05/19/2015] [Indexed: 01/29/2023]
Abstract
PURPOSE The efficacy of most anticancer treatments, including radiotherapy, depends on an ability to cause DNA double-strand breaks (DSBs). Very early during the DNA damage signalling process, the histone isoform H2AX is phosphorylated to form γH2AX. With the aim of positron emission tomography (PET) imaging of DSBs, we synthesized a (89)Zr-labelled anti-γH2AX antibody, modified with the cell-penetrating peptide, TAT, which includes a nuclear localization sequence. METHODS (89)Zr-anti-γH2AX-TAT was synthesized using EDC/NHS chemistry for TAT peptide linkage. Desferrioxamine conjugation allowed labelling with (89)Zr. Uptake and retention of (89)Zr-anti-γH2AX-TAT was evaluated in the breast adenocarcinoma cell line MDA-MB-468 in vitro or as xenografts in athymic mice. External beam irradiation was used to induce DSBs and expression of γH2AX. Since (89)Zr emits ionizing radiation, detailed radiobiological measurements were included to ensure (89)Zr-anti-γH2AX-TAT itself does not cause any additional DSBs. RESULTS Uptake of (89)Zr-anti-γH2AX-TAT was similar to previous results using (111)In-anti-γH2AX-TAT. Retention of (89)Zr-anti-γH2AX-TAT was eightfold higher at 1 h post irradiation, in cells expressing γH2AX, compared to non-irradiated cells or to non-specific IgG control. PET imaging of mice showed higher uptake of (89)Zr-anti-γH2AX-TAT in irradiated xenografts, compared to non-irradiated or non-specific controls (12.1 ± 1.6 vs 5.2 ± 1.9 and 5.1 ± 0.8%ID/g, respectively; p < 0.0001). The mean absorbed dose to the nucleus of cells taking up (89)Zr-anti-γH2AX-TAT was twofold lower compared to (111)In-anti-γH2AX-TAT. Additional exposure of neither irradiated nor non-irradiated cells nor tissues to (89)Zr-anti-γH2AX-TAT resulted in any significant changes in the number of observable DNA DSBs, γH2AX foci or clonogenic survival. CONCLUSION (89)Zr-anti-γH2AX-TAT allows PET imaging of DNA DSBs in a tumour xenograft mouse model.
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Affiliation(s)
- James C Knight
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7LJ, UK
| | - Caitríona Topping
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7LJ, UK
| | - Michael Mosley
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7LJ, UK
| | - Veerle Kersemans
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7LJ, UK
| | - Nadia Falzone
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7LJ, UK
- Royal Marsden Hospital, Sutton, Surrey, UK
| | | | - Bart Cornelissen
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford, OX3 7LJ, UK.
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Knight JC, Mosley M, Stratford MRL, Uyeda HT, Benink HA, Cong M, Fan F, Faulkner S, Cornelissen B. Development of an enzymatic pretargeting strategy for dual-modality imaging. Chem Commun (Camb) 2015; 51:4055-8. [PMID: 25660394 DOI: 10.1039/c4cc10265g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2024]
Abstract
A pretargeted imaging strategy based on the HaloTag dehalogenase enzyme is described. Here, a HaloTag-Trastuzumab conjugate has been used as the primary agent targeting HER2 expression, and three new radiolabelled HaloTag ligands have been used as secondary agents, two of which offer dual-modality (SPECT/optical) imaging capability.
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Affiliation(s)
- J C Knight
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK.
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Hillyar CRT, Knight JC, Vallis KA, Cornelissen B. PET and SPECT Imaging for the Acceleration of Anti-Cancer Drug Development. Curr Drug Targets 2015; 16:582-91. [PMID: 25901527 DOI: 10.2174/1389450116666150330113747] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 01/19/2015] [Accepted: 03/16/2015] [Indexed: 11/22/2022]
Abstract
Lead-compound optimization is an iterative process in the cancer drug development pipeline, in which small molecule inhibitors or biological compounds that are selected for their ability to bind specific targets are synthesised, tested and optimised. This process can be accelerated significantly using molecular imaging with nuclear medicine techniques, which aim to monitor the biodistribution and pharmacokinetics of radiolabelled versions of compounds. Positron emission tomography (PET) and single-photon emission computed tomography (SPECT) can be used to quantify fourdimensional (temporal and spatial) clinically relevant information, to demonstrate tumor uptake of, and monitor the response to treatment with lead-compounds. This review discusses the pre-clinical and clinical value of the information provided by nuclear medicine imaging compared to the histological analysis of biopsied tissue samples. Also, the role of nuclear medicine imaging is discussed with regard to the assessment of the treatment response, radiotracer biodistribution, tumor accumulation, toxicity, and pharmacokinetic parameters, with mention of microdosing studies, pre-targeting strategies, and pharmacokinetic modelling.
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Affiliation(s)
| | | | | | - Bart Cornelissen
- CRUK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Off Roosevelt Drive, Oxford OX3 7LJ, UK.
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Foerster C, Knight JC, Wuest M, Rowan B, Lapi SE, Amoroso AJ, Edwards PG, Wuest F. [64Cu]Cu-CryptTM – A novel cryptate for copper-64? Nucl Med Biol 2014. [DOI: 10.1016/j.nucmedbio.2014.05.127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Abstract
We report on the fabrication and characterization of a polarization-maintaining multicore fiber. The fiber has 98 aligned cores, each with a birefringence of ≈2.3×10-4. The beat length, polarization extinction ratio, and polarization orientation are characterized.
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Abstract
Prostate adenocarcinoma is the most common newly diagnosed cancer in males. Pulmonary and pleural metastasis are not uncommon on autopsy, but malignant effusions are not common clinical findings. There are no current recommendations to guide prostate specific antigen level assessment in pleural fluid. A 73 yo w/prostate cancer presented with complaints of subacute worsening of exertional dyspnea. He underwent a CT of the chest which excluded pulmonary emboli but did show moderate to large bilateral pleural effusions. The patient had a thoracentesis performed which confirmed an exudative effusion with atypical cells and elevated PSA levels. Metastatic visceral & parietal foci of prostate adenocarcinoma were found on medical pleuroscopy. The patient was symptomatically treated with bilateral tunneled chest tube catheters for intermittent drainage. Pulmonary metastasis secondary to prostate cancer is commonly found on autopsy, with pulmonary metastasis in 46% of patients and pleural metastasis in 21% of patients. Pleural effusions are not common, in one series, only 6/620 (1%) were found to have pleural masses/nodules or effusions. Diagnosis of pleural effusion secondary to metastatic prostate cancer can be achieved by direct cytology evaluation and/or PSA level elevation in the fluid. While specific, the sensitivity is not high enough to rule out disease if negative. Elevated pleural fluid PSA levels may aid in the diagnosis; however, there are no current recommendations as to what level may be considered diagnostic. Further studies are needed to define the sensitivity and specificity of PSA in pleural fluid.
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Affiliation(s)
- James C Knight
- University of Cincinnati, Pulmonary, Critical Care, and Sleep Division, 231 Albert Sabin Way, ML 0564, Cincinnati, OH 45267-0564, USA
| | - Malia A Ray
- Mercy Medical Associates, 2055 Hospital Drive, Suite 200, Batavia, OH 45103, USA
| | - Sadia Benzaquen
- University of Cincinnati, Pulmonary, Critical Care, and Sleep Division, 231 Albert Sabin Way, ML 0564, Cincinnati, OH 45267-0564, USA
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Knight JC, Cornelissen B. Bioorthogonal chemistry: implications for pretargeted nuclear (PET/SPECT) imaging and therapy. Am J Nucl Med Mol Imaging 2014; 4:96-113. [PMID: 24753979 PMCID: PMC3992206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 12/06/2013] [Indexed: 06/03/2023]
Abstract
Due to their rapid and highly selective nature, bioorthogonal chemistry reactions are attracting a significant amount of recent interest in the radiopharmaceutical community. Over the last few years, reactions of this type have found tremendous utility in the construction of new radiopharmaceuticals and as a method of bioconjugation. Furthermore, reports are beginning to emerge in which these reactions are also being applied in vivo to facilitate a novel pretargeting strategy for the imaging and therapy of cancer. The successful implementation of such an approach could lead to dramatic improvements in image quality, therapeutic index, and reduced radiation dose to non-target organs and tissues. This review will focus on the potential of various bioorthogonal chemistry reactions to be used successfully in such an approach.
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Affiliation(s)
- James C Knight
- CR-UK/MRC Gray Institute for Radiation Oncology and Biology, University of OxfordOxford, OX3 7LJ, United Kingdom
- Radiobiology Research Institute, Churchill HospitalOxford, OX3 7LJ, United Kingdom
| | - Bart Cornelissen
- CR-UK/MRC Gray Institute for Radiation Oncology and Biology, University of OxfordOxford, OX3 7LJ, United Kingdom
- Radiobiology Research Institute, Churchill HospitalOxford, OX3 7LJ, United Kingdom
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Foerster C, Knight JC, Wuest M, Rowan B, Lapi SE, Amoroso AJ, Edwards PG, Wuest F. Synthesis, complex stability and small animal PET imaging of a novel 64Cu-labelled cryptand molecule. Med Chem Commun 2014. [DOI: 10.1039/c4md00174e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The radiosynthesis and radiopharmacological evaluation including small animal PET imaging of a novel 64Cu-labelled cryptand molecule ([64Cu]CryptTM) possessing a tris-pyridyl/tris-amido set of donor atoms is described.
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Affiliation(s)
| | | | - Melinda Wuest
- Department of Oncology
- University of Alberta
- Edmonton, Canada
| | - Brendan Rowan
- Cardiff University of Wales – Department of Chemistry
- Cardiff, UK
| | - Suzanne E. Lapi
- Department of Radiology
- Washington University School of Medicine
- St. Louis, USA
| | | | - Peter G. Edwards
- Cardiff University of Wales – Department of Chemistry
- Cardiff, UK
| | - Frank Wuest
- Department of Oncology
- University of Alberta
- Edmonton, Canada
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Abstract
We investigate evidence of the formation of nonbridging oxygen hole centers in pure silica photonic crystal fibers from 5 ps 1064 nm pulses. The formation of the defects is attributed to the breaking of stressed silicon-oxygen bonds in the glass matrix through a many-photon process. We compare the photodarkening induced by the 1064 nm pump with photodarkening induced by short wavelength light in a 1064 nm pumped supercontinuum extending to 400 nm. It is shown that the higher peak power at the pump wavelength makes it a more significant cause of photodarkening when compared to the shorter wavelength light generated in the fiber.
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Affiliation(s)
- J M Stone
- Centre for Photonics and Photonic Materials, Department of Physics, University of Bath, Bath, UK.
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MacDonald D, Alaghehbandan R, Knight JC, Rose J, Collins KD. Using administrative databases in oncological population health research: a Canadian experience. ACTA ACUST UNITED AC 2013. [DOI: 10.13172/2053-3918-1-1-535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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47
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Chapman BH, Doronkin AV, Stone JM, Knight JC, Popov SV, Taylor JR. Femtosecond pulses at 20 GHz repetition rate through spectral masking of a phase modulated signal and nonlinear pulse compression. Opt Express 2013; 21:5671-5676. [PMID: 23482140 DOI: 10.1364/oe.21.005671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We present a laser system capable of producing 190 femtosecond pulses at a repetition rate of 20 GHz. The spectral masking of a phase modulated diode laser is used to produce a train of picosecond pulses which are compressed using a fibre-grating compressor followed by subsequent adiabatic soliton compression to the femtosecond regime using a tapered photonic crystal fiber.
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Affiliation(s)
- B H Chapman
- Femtosecond Optics Group, Physics Department, Imperial College, Prince Consort Road, London SW7 2AZ, UK
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48
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Knight JC, Wuest M, Saad FA, Wang M, Chapman DW, Jans HS, Lapi SE, Kariuki BM, Amoroso AJ, Wuest F. Synthesis, characterisation and evaluation of a novel copper-64 complex with selective uptake in EMT-6 cells under hypoxic conditions. Dalton Trans 2013; 42:12005-14. [DOI: 10.1039/c3dt50960e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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49
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Saad FA, Knight JC, Kariuki BM, Amoroso AJ. Co-ordinative properties of a tripodal trisamide ligand with a capped octahedral preference. Dalton Trans 2013; 42:14826-35. [DOI: 10.1039/c3dt51791h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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50
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Knight JC, Richter S, Wuest M, Way JD, Wuest F. Synthesis and evaluation of an 18F-labelled norbornene derivative for copper-free click chemistry reactions. Org Biomol Chem 2013; 11:3817-25. [DOI: 10.1039/c3ob40548f] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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