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McDonough R, Williams CC, Hartley CJ, French N, Scott C, Lewis DA. Kinetic Model for the Heterogeneous Biocatalytic Reactions Using Tethered Cofactors. Langmuir 2024; 40:6685-6693. [PMID: 38525517 DOI: 10.1021/acs.langmuir.3c02958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
Understanding the mechanism of interfacial enzyme kinetics is critical to the development of synthetic biological systems for the production of value-added chemicals. Here, the interfacial kinetics of the catalysis of β-nicotinamide adenine dinucleotide (NAD+)-dependent enzymes acting on NAD+ tethered to the surface of silica nanoparticles (SiNPs) has been investigated using two complementary and supporting kinetic approaches: enzyme excess and reactant (NAD+) excess. Kinetic models developed for these two approaches characterize several critical reaction steps including reversible enzyme adsorption, complexation, decomplexation, and catalysis of the surface-bound enzyme/NAD+ complex. The analysis reveals a concentrating effect resulting in a very high local concentration of enzyme and cofactor on the particle surface, in which the enzyme is saturated by surface-bound NAD, facilitating a rate enhancement of enzyme/NAD+ complexation and catalysis. This resulted in high enzyme efficiency within the tethered NAD+ system compared to that of the free enzyme/NAD+ system, which increases with decreasing enzyme concentration. The role of enzyme adsorption onto solid substrates with a tethered catalyst (such as NAD+) has potential for creating highly efficient flow biocatalytic systems.
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Affiliation(s)
- Rowan McDonough
- Institute for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Bedford Park, SA 5042, Australia
| | | | | | - Nigel French
- CSIRO Environment, Black Mountain, ACT 2601, Australia
| | - Colin Scott
- CSIRO Environment, Black Mountain, ACT 2601, Australia
| | - David A Lewis
- Institute for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Bedford Park, SA 5042, Australia
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2
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Hunt NJ, Lockwood GP, Heffernan SJ, Daymond J, Ngu M, Narayanan RK, Westwood LJ, Mohanty B, Esser L, Williams CC, Kuncic Z, McCourt PAG, Le Couteur DG, Cogger VC. Oral nanotherapeutic formulation of insulin with reduced episodes of hypoglycaemia. Nat Nanotechnol 2024; 19:534-544. [PMID: 38168926 PMCID: PMC11026164 DOI: 10.1038/s41565-023-01565-2] [Citation(s) in RCA: 1] [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] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 11/02/2023] [Indexed: 01/05/2024]
Abstract
Injectable insulin is an extensively used medication with potential life-threatening hypoglycaemic events. Here we report on insulin-conjugated silver sulfide quantum dots coated with a chitosan/glucose polymer to produce a responsive oral insulin nanoformulation. This formulation is pH responsive, is insoluble in acidic environments and shows increased absorption in human duodenum explants and Caenorhabditis elegans at neutral pH. The formulation is sensitive to glucosidase enzymes to trigger insulin release. It is found that the formulation distributes to the liver in mice and rats after oral administration and promotes a dose-dependent reduction in blood glucose without promoting hypoglycaemia or weight gain in diabetic rodents. Non-diabetic baboons also show a dose-dependent reduction in blood glucose. No biochemical or haematological toxicity or adverse events were observed in mice, rats and non-human primates. The formulation demonstrates the potential to orally control blood glucose without hypoglycaemic episodes.
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Affiliation(s)
- Nicholas J Hunt
- Faculty of Medicine and Health, The University of Sydney, Camperdown, New South Wales, Australia.
- Sydney Nano Institute, The University of Sydney, Camperdown, New South Wales, Australia.
- Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia.
- ANZAC Research Institute, Concord Repatriation General Hospital, Sydney Local Health District (SLHD), Concord, New South Wales, Australia.
| | - Glen P Lockwood
- Faculty of Medicine and Health, The University of Sydney, Camperdown, New South Wales, Australia
- ANZAC Research Institute, Concord Repatriation General Hospital, Sydney Local Health District (SLHD), Concord, New South Wales, Australia
| | - Scott J Heffernan
- Royal Prince Alfred Hospital, SLHD, Camperdown, New South Wales, Australia
| | - Jarryd Daymond
- Sydney Nano Institute, The University of Sydney, Camperdown, New South Wales, Australia
- Sydney Business School, The University of Sydney, Camperdown, New South Wales, Australia
| | - Meng Ngu
- ANZAC Research Institute, Concord Repatriation General Hospital, Sydney Local Health District (SLHD), Concord, New South Wales, Australia
- Department of Gastroenterology, Concord Repatriation General Hospital, SLHD, Concord, New South Wales, Australia
| | - Ramesh K Narayanan
- Faculty of Medicine and Health, The University of Sydney, Camperdown, New South Wales, Australia
- ANZAC Research Institute, Concord Repatriation General Hospital, Sydney Local Health District (SLHD), Concord, New South Wales, Australia
| | - Lara J Westwood
- Faculty of Medicine and Health, The University of Sydney, Camperdown, New South Wales, Australia
- Sydney Nano Institute, The University of Sydney, Camperdown, New South Wales, Australia
- ANZAC Research Institute, Concord Repatriation General Hospital, Sydney Local Health District (SLHD), Concord, New South Wales, Australia
| | - Biswaranjan Mohanty
- Sydney Analytical Core Research Facility, The University of Sydney, Camperdown, New South Wales, Australia
| | - Lars Esser
- CSIRO Manufacturing, Clayton, Victoria, Australia
| | | | - Zdenka Kuncic
- Sydney Nano Institute, The University of Sydney, Camperdown, New South Wales, Australia
- School of Physics, The University of Sydney, Camperdown, New South Wales, Australia
| | - Peter A G McCourt
- Faculty of Medicine and Health, The University of Sydney, Camperdown, New South Wales, Australia
- ANZAC Research Institute, Concord Repatriation General Hospital, Sydney Local Health District (SLHD), Concord, New South Wales, Australia
- Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - David G Le Couteur
- Faculty of Medicine and Health, The University of Sydney, Camperdown, New South Wales, Australia
- Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia
- ANZAC Research Institute, Concord Repatriation General Hospital, Sydney Local Health District (SLHD), Concord, New South Wales, Australia
| | - Victoria C Cogger
- Faculty of Medicine and Health, The University of Sydney, Camperdown, New South Wales, Australia.
- ANZAC Research Institute, Concord Repatriation General Hospital, Sydney Local Health District (SLHD), Concord, New South Wales, Australia.
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3
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Ardana A, Ghosh S, Huda P, Fletcher NL, Thurecht KJ, Williams CC. RAFT Polymer-Antibody Conjugation: Squaramide Ester Chemistry Leads to Conjugates with a Therapeutic Anti-EGFR Antibody with Full Retention of Activity and Increased Tumor Uptake In Vivo. Mol Pharm 2023. [PMID: 37218930 DOI: 10.1021/acs.molpharmaceut.3c00085] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Covalent conjugation of a biologically stable polymer to a therapeutic protein, e.g., an antibody, holds many benefits such as prolonged plasma exposure of the protein and improved tumor uptake. Generation of defined conjugates is advantageous in many applications, and a range of site-selective conjugation methods have been reported. Many current coupling methods lead to dispersity in coupling efficiencies with subsequent conjugates of less-well-defined structure, which impacts reproducibility of manufacture and ultimately may impact successful translation to treat or image diseases. We explored designing stable, reactive groups for polymer conjugation reactions that would lead to conjugates through the simplest and most abundant residue on most proteins, the lysine residue, yielding conjugates in high purity and demonstrating retention of mAb efficacy through surface plasmon resonance (SPR), cell targeting, and in vivo tumor targeting. We utilized squaric acid diesters as coupling agents for selective amidation of lysine residues and were able to selectively conjugate one, or two, high-molecular-weight polymers to a therapeutically relevant antibody, 528mAb, that subsequently retained full binding specificity. Water-soluble copolymers of N-(2-hydroxypropyl) methacrylamide (HPMA) and N-isopropylacrylamide (NIPAM) were prepared by Reversible Addition-Fragmentation chain-Transfer (RAFT) polymerization and we demonstrated that a dual-dye-labeled antibody-RAFT conjugate (528mAb-RAFT) exhibited effective tumor targeting in model breast cancer xenografts in mice. The combination of the precise and selective squaric acid ester conjugation method, with the use of RAFT polymers, leads to a promising strategic partnership for improved therapeutic protein-polymer conjugates having a very-well-defined structure.
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Affiliation(s)
- Aditya Ardana
- Commonwealth Scientific and Industrial Research Organization Manufacturing, Bayview Avenue, Clayton, Melbourne, Victoria 3168, Australia
| | - Saikat Ghosh
- Australian Institute for Bioengineering and Nanotechnology and Centre for Advanced Imaging, University of Queensland, Brisbane, St Lucia, Queensland, 4072, Australia
- Australian Research Council Training Centre for Innovation in Biomedical Imaging Technologies, University of Queensland, Brisbane, St Lucia, Queensland 4072, Australia
| | - Pie Huda
- Australian Institute for Bioengineering and Nanotechnology and Centre for Advanced Imaging, University of Queensland, Brisbane, St Lucia, Queensland, 4072, Australia
| | - Nicholas L Fletcher
- Australian Institute for Bioengineering and Nanotechnology and Centre for Advanced Imaging, University of Queensland, Brisbane, St Lucia, Queensland, 4072, Australia
| | - Kristofer J Thurecht
- Australian Institute for Bioengineering and Nanotechnology and Centre for Advanced Imaging, University of Queensland, Brisbane, St Lucia, Queensland, 4072, Australia
- Australian Research Council Training Centre for Innovation in Biomedical Imaging Technologies, University of Queensland, Brisbane, St Lucia, Queensland 4072, Australia
| | - Charlotte C Williams
- Commonwealth Scientific and Industrial Research Organization Manufacturing, Bayview Avenue, Clayton, Melbourne, Victoria 3168, Australia
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Subasic CN, Ardana A, Chan LJ, Huang F, Scoble JA, Butcher NJ, Meagher L, Chiefari J, Kaminskas LM, Williams CC. Poly(HPMA-co-NIPAM) copolymer as an alternative to polyethylene glycol-based pharmacokinetic modulation of therapeutic proteins. Int J Pharm 2021; 608:121075. [PMID: 34481889 DOI: 10.1016/j.ijpharm.2021.121075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 06/17/2021] [Revised: 08/24/2021] [Accepted: 08/31/2021] [Indexed: 12/21/2022]
Abstract
PEGylation is the standard approach for prolonging the plasma exposure of protein therapeutics but has limitations. We explored whether polymers prepared by Reversible Addition-Fragmentation chain-Transfer (RAFT) may provide better alternatives to polyethylene glycol (PEG). Four RAFT polymers were synthesised with varying compositions, molar mass (Mn), and structures, including a homopolymer of N-(2-hydroxypropyl)methacrylamide, (pHPMA) and statistical copolymers of HPMA with poly(ethylene glycol methyl ether acrylate) p(HPMA-co-PEGA); HPMA and N-acryloylmorpholine, p(HPMA-co-NAM); and HPMA and N-isopropylacrylamide, p(HPMA-co-NIPAM). The intravenous pharmacokinetics of the polymers were then evaluated in rats. The in vitro activity and in vivo pharmacokinetics of p(HPMA-co-NIPAM)-conjugated trastuzumab Fab' and full length mAb were then evaluated. p(HPMA-co-NIPAM) prolonged plasma exposure more avidly compared to the other p(HPMA) polymers or PEG, irrespective of molecular weight. When conjugated to trastuzumab-Fab', p(HPMA-co-NIPAM) prolonged plasma exposure of the Fab' similar to PEG-Fab'. The generation of anti-PEG IgM in rats 7 days after intravenous and subcutaneous dosing of p(HPMA-co-NIPAM) conjugated trastuzumab mAb was also examined and was shown to exhibit lower immunogenicity than the PEGylated construct. These data suggest that p(HPMA-co-NIPAM) has potential as a promising copolymer for use as an alternative conjugation strategy to PEG, to prolong the plasma exposure of therapeutic proteins.
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Affiliation(s)
- Christopher N Subasic
- School of Biomedical Sciences, University of Queensland, St Lucia, QLD 4072, Australia
| | - Aditya Ardana
- CSIRO Manufacturing, 343 Royal Parade, Parkville, Victoria 3052, Australia
| | - Linda J Chan
- Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Fei Huang
- CSIRO Manufacturing, 343 Royal Parade, Parkville, Victoria 3052, Australia
| | - Judith A Scoble
- CSIRO Manufacturing, 343 Royal Parade, Parkville, Victoria 3052, Australia
| | - Neville J Butcher
- School of Biomedical Sciences, University of Queensland, St Lucia, QLD 4072, Australia
| | - Laurence Meagher
- CSIRO Manufacturing, 343 Royal Parade, Parkville, Victoria 3052, Australia; Department of Materials Science and Engineering, Monash University, 20 Research Way, Clayton, Victoria 3168, Australia
| | - John Chiefari
- CSIRO Manufacturing, 343 Royal Parade, Parkville, Victoria 3052, Australia
| | - Lisa M Kaminskas
- School of Biomedical Sciences, University of Queensland, St Lucia, QLD 4072, Australia; Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia.
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5
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He Y, Khan T, Kryza T, Jones ML, Goh JB, Lyons NJ, Pearce LA, Lee MD, Gough M, Rogers R, Davies CM, Gilks CB, Hodgkinson T, Lourie R, Barry SC, Perrin LC, Williams CC, Puttick S, Adams TE, Munro TP, Hooper JD, Chetty N. Preclinical Evaluation of a Fluorescent Probe Targeting Receptor CDCP1 for Identification of Ovarian Cancer. Mol Pharm 2021; 18:3464-3474. [PMID: 34448393 DOI: 10.1021/acs.molpharmaceut.1c00401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Optimal cytoreduction for ovarian cancer is often challenging because of aggressive tumor biology and advanced stage. It is a critical issue since the extent of residual disease after surgery is the key predictor of ovarian cancer patient survival. For a limited number of cancers, fluorescence-guided surgery has emerged as an effective aid for tumor delineation and effective cytoreduction. The intravenously administered fluorescent agent, most commonly indocyanine green (ICG), accumulates preferentially in tumors, which are visualized under a fluorescent light source to aid surgery. Insufficient tumor specificity has limited the broad application of these agents in surgical oncology including for ovarian cancer. In this study, we developed a novel tumor-selective fluorescent agent by chemically linking ICG to mouse monoclonal antibody 10D7 that specifically recognizes an ovarian cancer-enriched cell surface receptor, CUB-domain-containing protein 1 (CDCP1). 10D7ICG has high affinity for purified recombinant CDCP1 and CDCP1 that is located on the surface of ovarian cancer cells in vitro and in vivo. Our results show that intravenously administered 10D7ICG accumulates preferentially in ovarian cancer, permitting visualization of xenograft tumors in mice. The data suggest CDCP1 as a rational target for tumor-specific fluorescence-guided surgery for ovarian cancer.
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Affiliation(s)
- Yaowu He
- Mater Research Institute - The University of Queensland, Translational Research Institute, 37 Kent Street, Woolloongabba, QLD 4102, Australia
| | - Tashbib Khan
- Mater Research Institute - The University of Queensland, Translational Research Institute, 37 Kent Street, Woolloongabba, QLD 4102, Australia
| | - Thomas Kryza
- Mater Research Institute - The University of Queensland, Translational Research Institute, 37 Kent Street, Woolloongabba, QLD 4102, Australia
| | - Martina L Jones
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Justin B Goh
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Nicholas J Lyons
- Mater Research Institute - The University of Queensland, Translational Research Institute, 37 Kent Street, Woolloongabba, QLD 4102, Australia
| | | | | | - Madeline Gough
- Mater Research Institute - The University of Queensland, Translational Research Institute, 37 Kent Street, Woolloongabba, QLD 4102, Australia
| | - Rebecca Rogers
- Mater Research Institute - The University of Queensland, Translational Research Institute, 37 Kent Street, Woolloongabba, QLD 4102, Australia.,Mater Health Services, South Brisbane, QLD 4101, Australia
| | - Claire M Davies
- Mater Research Institute - The University of Queensland, Translational Research Institute, 37 Kent Street, Woolloongabba, QLD 4102, Australia.,Mater Health Services, South Brisbane, QLD 4101, Australia
| | - C Blake Gilks
- Department of Pathology and Laboratory Medicine, Vancouver General Hospital, University of British Columbia, Vancouver, BC V6T 2B5, Canada
| | | | - Rohan Lourie
- Mater Health Services, South Brisbane, QLD 4101, Australia
| | - Sinead C Barry
- Mater Health Services, South Brisbane, QLD 4101, Australia
| | - Lewis C Perrin
- Mater Health Services, South Brisbane, QLD 4101, Australia
| | | | | | | | - Trent P Munro
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia
| | - John D Hooper
- Mater Research Institute - The University of Queensland, Translational Research Institute, 37 Kent Street, Woolloongabba, QLD 4102, Australia
| | - Naven Chetty
- Mater Health Services, South Brisbane, QLD 4101, Australia
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6
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Rudd SE, Van Zuylekom JK, Raicevic A, Pearce LA, Cullinane C, Williams CC, Adams TE, Hicks RJ, Donnelly PS. Enzyme mediated incorporation of zirconium-89 or copper-64 into a fragment antibody for same day imaging of epidermal growth factor receptor. Chem Sci 2021; 12:9004-9016. [PMID: 34276928 PMCID: PMC8261882 DOI: 10.1039/d1sc01422f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 05/23/2021] [Indexed: 11/24/2022] Open
Abstract
Identification of tumors which over-express Epidermal Growth Factor Receptor (EGFR) is important in selecting patients for anti-EGFR therapies. Enzymatic bioconjugation was used to introduce positron-emitting radionuclides (89Zr, 64Cu) into an anti-EGFR antibody fragment for Positron Emission Tomography (PET) imaging the same day as injection. A monovalent antibody fragment with high affinity for EGFR was engineered to include a sequence that is recognized by the transpeptidase sortase A. Two different metal chelators, one for 89ZrIV and one for 64CuII, were modified with a N-terminal glycine to enable them to act as substrates in sortase A mediated bioconjugation to the antibody fragment. Both fragments provided high-quality PET images of EGFR positive tumors in a mouse model at 3 hours post-injection, a significant advantage when compared to radiolabeled full antibodies that require several days between injection of the tracer and imaging. The use of enzymatic bioconjugation gives reproducible homogeneous products with the metal complexes selectively installed on the C-terminus of the antibody potentially simplifying regulatory approval.
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Affiliation(s)
- Stacey E Rudd
- School of Chemistry and Bio21 Molecular Science, Biotechnology Institute University of Melbourne Parkville Victoria 3010 Australia
| | | | - Anna Raicevic
- CSIRO Manufacturing Parkville Victoria 3052 Australia
| | | | - Carleen Cullinane
- Research Division, Peter MacCallum Cancer Centre Melbourne Victoria 3000 Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne Parkville Victoria Australia
| | | | | | - Rodney J Hicks
- Sir Peter MacCallum Department of Oncology, University of Melbourne Parkville Victoria Australia
| | - Paul S Donnelly
- School of Chemistry and Bio21 Molecular Science, Biotechnology Institute University of Melbourne Parkville Victoria 3010 Australia
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8
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Hartley CJ, Williams CC, Scoble JA, Churches QI, North A, French NG, Nebl T, Coia G, Warden AC, Simpson G, Frazer AR, Jensen CN, Turner NJ, Scott C. Engineered enzymes that retain and regenerate their cofactors enable continuous-flow biocatalysis. Nat Catal 2019. [DOI: 10.1038/s41929-019-0353-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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9
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Lee MD, Tong WY, Nebl T, Pearce LA, Pham TM, Golbaz-Hagh A, Puttick S, Rose S, Adams TE, Williams CC. Dual Site-Specific Labeling of an Antibody Fragment through Sortase A and π-Clamp Conjugation. Bioconjug Chem 2019; 30:2539-2543. [DOI: 10.1021/acs.bioconjchem.9b00639] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Michael D. Lee
- CSIRO Manufacturing, Parkville, Victoria 3052, Australia
| | - Wing Yin Tong
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Thomas Nebl
- CSIRO Manufacturing, Parkville, Victoria 3052, Australia
| | | | - Tam M. Pham
- CSIRO Manufacturing, Parkville, Victoria 3052, Australia
| | - Arghavan Golbaz-Hagh
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St. Lucia, 4072, Australia
| | - Simon Puttick
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St. Lucia, 4072, Australia
- CSIRO Health and Biosecurity, Herston, Queensland 4029, Australia
| | - Stephen Rose
- CSIRO Health and Biosecurity, Herston, Queensland 4029, Australia
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10
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Kaminskas LM, Williams CC, Leong NJ, Chan LJ, Butcher NJ, Feeney OM, Porter CJH, Tyssen D, Tachedjian G, Ascher DB. A 30 kDa polyethylene glycol-enfuvirtide complex enhances the exposure of enfuvirtide in lymphatic viral reservoirs in rats. Eur J Pharm Biopharm 2019; 137:218-226. [PMID: 30851352 DOI: 10.1016/j.ejpb.2019.03.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [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: 07/04/2018] [Revised: 03/03/2019] [Accepted: 03/05/2019] [Indexed: 11/25/2022]
Abstract
HIV therapy with anti-retroviral drugs is limited by the poor exposure of viral reservoirs, such as lymphoid tissue, to these small molecule drugs. We therefore investigated the effect of PEGylation on the anti-retroviral activity and subcutaneous lymphatic pharmacokinetics of the peptide-based fusion inhibitor enfuvirtide in thoracic lymph duct cannulated rats. Both the peptide and the PEG were quantified in plasma and lymph via ELISA. Conjugation to a single 5 kDa linear PEG decreased anti-HIV activity three-fold compared to enfuvirtide. Whilst plasma and lymphatic exposure to peptide mass was moderately increased, the loss of anti-viral activity led to an overall decrease in exposure to enfuvirtide activity. A 20 kDa 4-arm branched PEG conjugated with an average of two enfuvirtide peptides decreased peptide activity by six-fold. Plasma and lymph exposure to enfuvirtide, however, increased significantly such that anti-viral activity was increased two- and six-fold respectively. The results suggest that a multi-enfuvirtide-PEG complex may optimally enhance the anti-retroviral activity of the peptide in plasma and lymph.
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Affiliation(s)
- Lisa M Kaminskas
- School of Biomedical Sciences, University of Queensland, Brisbane, St Lucia, QLD 4072, Australia.
| | - Charlotte C Williams
- CSIRO Materials Science and Engineering, 343 Royal Parade, Parkville, Victoria 3052, Australia
| | - Nathania J Leong
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Linda J Chan
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Neville J Butcher
- School of Biomedical Sciences, University of Queensland, Brisbane, St Lucia, QLD 4072, Australia
| | - Orlagh M Feeney
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Christopher J H Porter
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - David Tyssen
- Burnet Institute, 89 Commercial Rd, Melbourne, Victoria 3004, Australia; Department of Microbiology, Monash University, Clayton, Victoria 3168, Australia; Department of Microbiology and Immunology, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria 3000, Australia; School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, Victoria 3000, Australia
| | - Gilda Tachedjian
- Burnet Institute, 89 Commercial Rd, Melbourne, Victoria 3004, Australia; Department of Microbiology, Monash University, Clayton, Victoria 3168, Australia; Department of Microbiology and Immunology, University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria 3000, Australia; School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, Victoria 3000, Australia
| | - David B Ascher
- Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, 30 Flemington Road, Parkville 3052, Australia
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11
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Li N, Weng D, Wang SM, Zhang Y, Chen SS, Yin ZF, Zhai J, Scoble J, Williams CC, Chen T, Qiu H, Wu Q, Zhao MM, Lu LQ, Mulet X, Li HP. Surfactant protein-A nanobody-conjugated liposomes loaded with methylprednisolone increase lung-targeting specificity and therapeutic effect for acute lung injury. Drug Deliv 2018; 24:1770-1781. [PMID: 29160134 PMCID: PMC8241200 DOI: 10.1080/10717544.2017.1402217] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [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] [Indexed: 12/11/2022] Open
Abstract
The advent of nanomedicine requires novel delivery vehicles to actively target their site of action. Here, we demonstrate the development of lung-targeting drug-loaded liposomes and their efficacy, specificity and safety. Our study focuses on glucocorticoids methylprednisolone (MPS), a commonly used drug to treat lung injuries. The steroidal molecule was loaded into functionalized nano-sterically stabilized unilamellar liposomes (NSSLs). Targeting functionality was performed through conjugation of surfactant protein A (SPANb) nanobodies to form MPS–NSSLs–SPANb. MPS–NSSLs–SPANb exhibited good size distribution, morphology, and encapsulation efficiency. Animal experiments demonstrated the high specificity of MPS–NSSLs–SPANb to the lung. Treatment with MPS–NSSLs–SPANb reduced the levels of TNF-α, IL-8, and TGF-β1 in rat bronchoalveolar lavage fluid and the expression of NK-κB in the lung tissues, thereby alleviating lung injuries and increasing rat survival. The nanobody functionalized nanoparticles demonstrate superior performance to treat lung injury when compared to that of antibody functionalized systems.
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Affiliation(s)
- Nan Li
- a Department of Respiratory Medicine , Shanghai Pulmonary Hospital, Tongji University School of Medicine , Shanghai , China.,b Department of Respiratory Medicine , People's Hospital Affiliated to ZhengZhou University , ZhengZhou , China
| | - Dong Weng
- a Department of Respiratory Medicine , Shanghai Pulmonary Hospital, Tongji University School of Medicine , Shanghai , China
| | - Shan-Mei Wang
- a Department of Respiratory Medicine , Shanghai Pulmonary Hospital, Tongji University School of Medicine , Shanghai , China
| | - Yuan Zhang
- a Department of Respiratory Medicine , Shanghai Pulmonary Hospital, Tongji University School of Medicine , Shanghai , China
| | - Shan-Shan Chen
- a Department of Respiratory Medicine , Shanghai Pulmonary Hospital, Tongji University School of Medicine , Shanghai , China.,c School of Medicine , Suzhou University , SuZhou , China
| | - Zhao-Fang Yin
- a Department of Respiratory Medicine , Shanghai Pulmonary Hospital, Tongji University School of Medicine , Shanghai , China.,c School of Medicine , Suzhou University , SuZhou , China
| | - Jiali Zhai
- d CSIRO Manufacturing , Clayton , Australia
| | - Judy Scoble
- e CSIRO Manufacturing , Parkville , Australia
| | | | - Tao Chen
- a Department of Respiratory Medicine , Shanghai Pulmonary Hospital, Tongji University School of Medicine , Shanghai , China
| | - Hui Qiu
- a Department of Respiratory Medicine , Shanghai Pulmonary Hospital, Tongji University School of Medicine , Shanghai , China
| | - Qin Wu
- a Department of Respiratory Medicine , Shanghai Pulmonary Hospital, Tongji University School of Medicine , Shanghai , China
| | - Meng-Meng Zhao
- a Department of Respiratory Medicine , Shanghai Pulmonary Hospital, Tongji University School of Medicine , Shanghai , China
| | - Li-Qin Lu
- a Department of Respiratory Medicine , Shanghai Pulmonary Hospital, Tongji University School of Medicine , Shanghai , China
| | | | - Hui-Ping Li
- a Department of Respiratory Medicine , Shanghai Pulmonary Hospital, Tongji University School of Medicine , Shanghai , China
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12
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Hartley CJ, French NG, Scoble JA, Williams CC, Churches QI, Frazer AR, Taylor MC, Coia G, Simpson G, Turner NJ, Scott C. Sugar analog synthesis by in vitro biocatalytic cascade: A comparison of alternative enzyme complements for dihydroxyacetone phosphate production as a precursor to rare chiral sugar synthesis. PLoS One 2017; 12:e0184183. [PMID: 29112947 PMCID: PMC5675407 DOI: 10.1371/journal.pone.0184183] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 08/18/2017] [Indexed: 11/19/2022] Open
Abstract
Carbon-carbon bond formation is one of the most challenging reactions in synthetic organic chemistry, and aldol reactions catalysed by dihydroxyacetone phosphate-dependent aldolases provide a powerful biocatalytic tool for combining C-C bond formation with the generation of two new stereo-centres, with access to all four possible stereoisomers of a compound. Dihydroxyacetone phosphate (DHAP) is unstable so the provision of DHAP for DHAP-dependent aldolases in biocatalytic processes remains complicated. Our research has investigated the efficiency of several different enzymatic cascades for the conversion of glycerol to DHAP, including characterising new candidate enzymes for some of the reaction steps. The most efficient cascade for DHAP production, comprising a one-pot four-enzyme reaction with glycerol kinase, acetate kinase, glycerophosphate oxidase and catalase, was coupled with a DHAP-dependent fructose-1,6-biphosphate aldolase enzyme to demonstrate the production of several rare chiral sugars. The limitation of batch biocatalysis for these reactions and the potential for improvement using kinetic modelling and flow biocatalysis systems is discussed.
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Affiliation(s)
- Carol J. Hartley
- CSIRO Land and Water, Black Mountain Laboratories, Canberra, Australia
| | - Nigel G. French
- CSIRO Land and Water, Black Mountain Laboratories, Canberra, Australia
| | | | | | | | - Andrew R. Frazer
- School of Chemistry, CoEBio3, University of Manchester, Manchester, United Kingdom
| | - Matthew C. Taylor
- CSIRO Land and Water, Black Mountain Laboratories, Canberra, Australia
| | - Greg Coia
- CSIRO Manufacturing, Parkville, Melbourne, Australia
| | | | - Nicholas J. Turner
- School of Chemistry, CoEBio3, University of Manchester, Manchester, United Kingdom
| | - Colin Scott
- CSIRO Land and Water, Black Mountain Laboratories, Canberra, Australia
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Chan LJ, Feeney OM, Leong NJ, McLeod VM, Porter CJ, Williams CC, Kaminskas LM. An Evaluation of Optimal PEGylation Strategies for Maximizing the Lymphatic Exposure and Antiviral Activity of Interferon after Subcutaneous Administration. Biomacromolecules 2017; 18:2866-2875. [DOI: 10.1021/acs.biomac.7b00794] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | | | - Charlotte C. Williams
- CSIRO Materials Science and Engineering, 343 Royal Parade, Parkville, Victoria 3052, Australia
| | - Lisa M. Kaminskas
- School
of Biomedical Sciences, University of Queensland, Brisbane, Saint Lucia, Queensland 4072, Australia
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14
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Welch NG, Easton CD, Scoble JA, Williams CC, Pigram PJ, Muir BW. A chemiluminescent sandwich ELISA enhancement method using a chromium (III) coordination complex. J Immunol Methods 2016; 438:59-66. [DOI: 10.1016/j.jim.2016.09.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 09/14/2016] [Accepted: 09/15/2016] [Indexed: 10/21/2022]
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15
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Welch NG, Scoble JA, Easton CD, Williams CC, Bradford BJ, Mamedova LK, Pigram PJ, Muir BW. High-Throughput Production of Chromium(III) Complexes for Antibody Immobilization. Anal Chem 2016; 88:10102-10110. [DOI: 10.1021/acs.analchem.6b02531] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Nicholas G. Welch
- Centre
for Materials and Surface Science and Department of Chemistry and
Physics, La Trobe University, Bundoora, Victoria 3086, Australia
- CSIRO, Manufacturing, Clayton, Victoria 3168, Australia
| | | | | | | | - Barry J. Bradford
- Kansas State University, Department of Animal Sciences
and Industry, Manhattan, Kansas 66506, United States
| | - Laman K. Mamedova
- Kansas State University, Department of Animal Sciences
and Industry, Manhattan, Kansas 66506, United States
| | - Paul J. Pigram
- Centre
for Materials and Surface Science and Department of Chemistry and
Physics, La Trobe University, Bundoora, Victoria 3086, Australia
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16
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Chan LJ, Ascher DB, Yadav R, Bulitta JB, Williams CC, Porter CJH, Landersdorfer CB, Kaminskas LM. Conjugation of 10 kDa Linear PEG onto Trastuzumab Fab' Is Sufficient to Significantly Enhance Lymphatic Exposure while Preserving in Vitro Biological Activity. Mol Pharm 2016; 13:1229-41. [PMID: 26871003 DOI: 10.1021/acs.molpharmaceut.5b00749] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The lymphatic system is a major conduit by which many diseases spread and proliferate. There is therefore increasing interest in promoting better lymphatic drug targeting. Further, antibody fragments such as Fabs have several advantages over full length monoclonal antibodies but are subject to rapid plasma clearance, which can limit the lymphatic exposure and activity of Fabs against lymph-resident diseases. This study therefore explored ideal PEGylation strategies to maximize biological activity and lymphatic exposure using trastuzumab Fab' as a model. Specifically, the Fab' was conjugated with single linear 10 or 40 kDa PEG chains at the hinge region. PEGylation led to a 3-4-fold reduction in binding affinity to HER2, but antiproliferative activity against HER2-expressing BT474 cells was preserved. Lymphatic pharmacokinetics were then examined in thoracic lymph duct cannulated rats after intravenous and subcutaneous dosing at 2 mg/kg, and the data were evaluated via population pharmacokinetic modeling. The Fab' displayed limited lymphatic exposure, but conjugation of 10 kDa PEG improved exposure by approximately 11- and 5-fold after intravenous (15% dose collected in thoracic lymph over 30 h) and subcutaneous (9%) administration, respectively. Increasing the molecular weight of the PEG to 40 kDa, however, had no significant impact on lymphatic exposure after intravenous (14%) administration and only doubled lymphatic exposure after subcutaneous administration (18%) when compared to 10 kDa PEG-Fab'. The data therefore suggests that minimal PEGylation has the potential to enhance the exposure and activity of Fab's against lymph-resident diseases, while no significant benefit is achieved with very large PEGs.
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Affiliation(s)
- Linda J Chan
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University , 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - David B Ascher
- Department of Biochemistry, University of Cambridge , Sanger Building, Downing Site, Cambridge, CB2 1GA, U.K
| | - Rajbharan Yadav
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University , 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Jürgen B Bulitta
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University , 381 Royal Parade, Parkville, Victoria 3052, Australia.,Center for Pharmacometrics and Systems Pharmacology, College of Pharmacy, University of Florida , Orlando, Florida 32816, United States
| | - Charlotte C Williams
- CSIRO Materials Science and Engineering , 343 Royal Parade, Parkville, Victoria 3052, Australia
| | - Christopher J H Porter
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University , 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Cornelia B Landersdorfer
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University , 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Lisa M Kaminskas
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University , 381 Royal Parade, Parkville, Victoria 3052, Australia
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17
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18
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Pereira ABD, Zeringue LK, Leonardi C, Jenny BF, Williams CC, McCormick ME, Moreira VR. Short communication: Substituting dry distillers grains with solubles and rumen-protected amino acids for soybean meal in late-lactation cows' diets based on corn silage or ryegrass silage. J Dairy Sci 2015; 98:8121-7. [PMID: 26364102 DOI: 10.3168/jds.2015-9604] [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: 03/20/2015] [Accepted: 07/10/2015] [Indexed: 11/19/2022]
Abstract
Excess protein in dairy cattle diets increases production costs and contributes to environmental pollution. The objective of the present study was to evaluate the effect of feeding dry distillers grains with solubles (DDGS) supplemented with rumen-protected Lys and Met in place of solvent-extracted soybean meal on the performance of late-lactation cows. Two experiments were carried out, with each using 24 late-lactating dairy cows distributed among 4 pens. In trial 1, corn silage was the main forage source. Control (HP1) total mixed ration (TMR) contained 16.3% crude protein (CP) with soybean meal as the main protein source. Treatment TMR (LP1) had 13.7% CP when soybean meal was replaced with DDGS and rumen-protected Lys and Met. Forage in trial 2 was ryegrass silage; control TMR (HP2; 15.4% CP) contained soybean meal and rumen-protected Met, whereas treatment TMR (LP2; 13.8% CP) contained DDGS and rumen-protected Lys and Met. Trials were analyzed as crossover design using the MIXED procedure of SAS (SAS Institute Inc., Cary NC) with cow as sampling unit and pen as the experimental unit. Treatments were similar in dry matter intake (21.0 and 20.4 kg/cow per day for HP1 and LP1, respectively) and milk yield (20.7 and 20.5 kg/cow per day for HP1 and LP1, respectively) during trial 1. Milk composition was similar between treatments, averaging 4.22, 3.73, 4.54, and 9.15, respectively, for fat, protein, lactose, and solids nonfat. Milk urea nitrogen decreased from 17.2 mg/dL for HP1 to 9.93 mg/dL for LP1. In trial 2, no significant differences were observed for dry matter intake (21.4 and 20.9 kg/cow per day for HP2 and LP2, respectively), milk yield (28.1 and 26.6 kg/d for HP2 and LP2, respectively), fat yield (0.99 vs. 0.92 kg/d for HP2 and LP2, respectively), protein yield (0.94 vs. 0.86 kg/d for HP2 and LP2, respectively) and lactose yield (1.37 vs. 1.28 for HP2 and LP2, respectively). Milk urea nitrogen decreased from 9.88 mg/dL with HP2 to 6.39 mg/dL with the LP2 treatment. Milk N efficiency tended to be higher for LP treatments in trial 1, but not in trial 2. Low milk urea N suggested nitrogen losses to the environment may be lower when cows were fed diets based on DDGS in both trials. The studies indicated that DDGS with rumen-protected Lys and Met could substitute solvent-extracted soybean meal in low-protein corn silage- and ryegrass silage-based diets for late-lactation dairy cows averaging 20.6 or 27.4 kg of milk/d, respectively.
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Affiliation(s)
- A B D Pereira
- School of Animal Science, Louisiana State University, Baton Rouge 70803
| | - L K Zeringue
- Southeast Research Station, Louisiana State University Agricultural Center, Franklinton 70438
| | - C Leonardi
- School of Public Health, Louisiana State University Health Sciences Center, New Orleans 70112
| | - B F Jenny
- School of Animal Science, Louisiana State University, Baton Rouge 70803
| | - C C Williams
- School of Animal Science, Louisiana State University, Baton Rouge 70803
| | - M E McCormick
- Southeast Research Station, Louisiana State University Agricultural Center, Franklinton 70438
| | - V R Moreira
- Southeast Research Station, Louisiana State University Agricultural Center, Franklinton 70438.
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19
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Wang R, Williams CC. Dynamic tunneling force microscopy for characterizing electronic trap states in non-conductive surfaces. Rev Sci Instrum 2015; 86:093708. [PMID: 26429449 DOI: 10.1063/1.4931065] [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] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Dynamic tunneling force microscopy (DTFM) is a scanning probe technique for real space mapping and characterization of individual electronic trap states in non-conductive films with atomic scale spatial resolution. The method is based upon the quantum mechanical tunneling of a single electron back and forth between a metallic atomic force microscopy tip and individual trap states in completely non-conducting surface. This single electron shuttling is measured by detecting the electrostatic force induced on the probe tip at the shuttling frequency. In this paper, the physical basis for the DTFM method is unfolded through a physical model and a derivation of the dynamic tunneling signal as a function of several experimental parameters is shown. Experimental data are compared with the theoretical simulations, showing quantitative consistency and verifying the physical model used. The experimental system is described and representative imaging results are shown.
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Affiliation(s)
- R Wang
- Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, USA
| | - C C Williams
- Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, USA
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20
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Chan LJ, Bulitta JB, Ascher DB, Haynes JM, McLeod VM, Porter CJH, Williams CC, Kaminskas LM. PEGylation does not significantly change the initial intravenous or subcutaneous pharmacokinetics or lymphatic exposure of trastuzumab in rats but increases plasma clearance after subcutaneous administration. Mol Pharm 2015; 12:794-809. [PMID: 25644368 DOI: 10.1021/mp5006189] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The lymphatic system plays a major role in the metastatic dissemination of cancer and has an integral role in immunity. PEGylation enhances drainage and lymphatic uptake following subcutaneous (sc) administration of proteins and protein-like polymers, but the impact of PEGylation of very large proteins (such as antibodies) on subcutaneous and lymphatic pharmacokinetics is unknown. This study therefore aimed to evaluate the impact of PEGylation on the sc absorption and lymphatic disposition of the anti-HER2 antibody trastuzumab in rats. PEG-trastuzumab was generated via the conjugation of a single 40 kDa PEG-NHS ester to trastuzumab. PEG-trastuzumab showed a 5-fold reduction in HER2 binding affinity, however the in vitro growth inhibitory effects were preserved as a result of changes in cellular trafficking when compared to native trastuzumab. The lymphatic pharmacokinetics of PEG-trastuzumab was evaluated in thoracic lymph duct cannulated rats after iv and sc administration and compared to the pharmacokinetics of native trastuzumab. The iv pharmacokinetics and lymphatic exposure of PEG-trastuzumab was similar when compared to trastuzumab. After sc administration, initial plasma pharmacokinetics and lymphatic exposure were also similar between PEG-trastuzumab and trastuzumab, but the absolute bioavailability of PEG-trastuzumab was 100% when compared to 86.1% bioavailability for trastuzumab. In contrast to trastuzumab, PEG-trastuzumab showed accelerated plasma clearance beginning approximately 7 days after sc, but not iv, administration, presumably as a result of the generation of anti-PEG IgM. This work suggests that PEGylation does not significantly alter the lymphatic disposition of very large proteins, and further suggests that it is unlikely to benefit therapy with monoclonal antibodies.
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Affiliation(s)
- Linda J Chan
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University , 381 Royal Parade, Parkville, Victoria 3052, Australia
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21
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22
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Baer S, Nigro J, Madej MP, Nisbet RM, Suryadinata R, Coia G, Hong LPT, Adams TE, Williams CC, Nuttall SD. Comparison of alternative nucleophiles for Sortase A-mediated bioconjugation and application in neuronal cell labelling. Org Biomol Chem 2014; 12:2675-85. [PMID: 24643508 DOI: 10.1039/c3ob42325e] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Sortase A (SrtA) enzyme from Staphylococcus aureus catalyses covalent attachment of protein substrates to pentaglycine cross-bridges in the Gram positive bacterial cell wall. In vitro SrtA-mediated protein ligation is now an important protein engineering tool for conjugation of substrates containing the LPXTGX peptide recognition sequence to oligo-glycine nucleophiles. In order to explore the use of alternative nucleophiles in this system, five different rhodamine-labelled compounds, with N-terminal nucleophilic amino acids, triglycine, glycine, and lysine, or N-terminal non-amino acid nucleophiles ethylenediamine and cadaverine, were synthesized. These compounds were tested for their relative abilities to function as nucleophiles in SrtA-mediated bioconjugation reactions. N-Terminal triglycine, glycine and ethylenediamine were all efficient in labelling a range of LPETGG containing recombinant antibody and scaffold proteins and peptides, while reduced activity was observed for the other nucleophiles across the range of proteins and peptides studied. Expansion of the range of available nucleophiles which can be utilised in SrtA-mediated bioconjugation expands the range of potential applications for this technology. As a demonstration of the utility of this system, SrtA coupling was used to conjugate the triglycine rhodamine-labelled nucleophile to the C-terminus of an Im7 scaffold protein displaying Aβ, a neurologically important peptide implicated in Alzheimer's disease. Purified, labelled protein showed Aβ-specific targeting to mammalian neuronal cells. Demonstration of targeting neuronal cells with a chimeric protein illustrates the power of this system, and suggests that SrtA-mediated direct cell-surface labelling and visualisation is an achievable goal.
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Affiliation(s)
- Samuel Baer
- CSIRO Materials Science and Engineering, 343 Royal Parade, Parkville, Victoria 3052, Australia.
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23
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Geiger AJ, Ward SH, Williams CC, Rude BJ, Cabrera CJ, Kalestch KN, Voelz BE. Short communication: Effects of increasing protein and energy in the milk replacer with or without direct-fed microbial supplementation on growth and performance of preweaned Holstein calves. J Dairy Sci 2014; 97:7212-9. [PMID: 25200791 DOI: 10.3168/jds.2013-7000] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [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: 05/06/2013] [Accepted: 06/13/2014] [Indexed: 11/19/2022]
Abstract
Forty-four Holstein calves were fed a direct-fed microbial (DFM) and 1 of 2 milk replacers to evaluate calf performance and growth. Treatments were (1) a control milk replacer [22:20; 22% crude protein (CP) and 20% fat], (2) an accelerated milk replacer (27:10; 27% CP and 10% fat), (3) the control milk replacer with added DFM (22:20+D), and (4) the accelerated milk replacer with added DFM (27:10+D). Dry matter intake, rectal temperatures, respiration scores and rates, and fecal scores were collected daily. Body weight, hip and withers height, heart girth, blood, and rumen fluid samples were collected weekly. Effects of treatment, sex, week, and their interactions were analyzed. Calves fed an accelerated milk replacer, regardless of DFM supplementation, consumed more CP and metabolizable energy in the milk replacer. No treatment differences were found for starter intake or intake of neutral detergent fiber or acid detergent fiber in the starter. Calves fed the accelerated milk replacer had greater preweaning and weaning body weight compared with calves fed the control milk replacer. Average daily gain was greater during the preweaning period for calves fed the accelerated milk replacer, but the same pattern did not hold true during the postweaning period. Feed efficiency did not differ among treatments. Hip height tended to be and withers height and heart girth were greater at weaning for calves fed the accelerated milk replacer compared with calves fed the control milk replacer. Fecal scores were greatest in calves fed DFM. Overall acetate, propionate, butyrate, and n-valerate concentrations were lower in calves fed the accelerated milk replacer, but DFM did not have an effect. Rumen pH was not different. Blood metabolites were unaffected by DFM supplementation, but calves fed the accelerated milk replacer had increased partial pressure of CO2, bicarbonate, and total bicarbonate in the blood. Direct-fed microbial supplementation did not appear to benefit the calf in this trial.
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Affiliation(s)
- A J Geiger
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State 39762
| | - S H Ward
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State 39762.
| | - C C Williams
- School of Animal Sciences, Louisiana State University, Baton Rouge 70803
| | - B J Rude
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State 39762
| | - C J Cabrera
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State 39762
| | - K N Kalestch
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State 39762
| | - B E Voelz
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State 39762
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24
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Paterson BM, Alt K, Jeffery CM, Price RI, Jagdale S, Rigby S, Williams CC, Peter K, Hagemeyer CE, Donnelly PS. Enzyme-mediated site-specific bioconjugation of metal complexes to proteins: sortase-mediated coupling of copper-64 to a single-chain antibody. Angew Chem Int Ed Engl 2014; 53:6115-9. [PMID: 24777818 DOI: 10.1002/anie.201402613] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [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: 02/20/2014] [Indexed: 01/28/2023]
Abstract
The enzyme-mediated site-specific bioconjugation of a radioactive metal complex to a single-chain antibody using the transpeptidase sortase A is reported. Cage amine sarcophagine ligands that were designed to function as substrates for the sortase A mediated bioconjugation to antibodies were synthesized and enzymatically conjugated to a single-chain variable fragment. The antibody fragment scFv(anti-LIBS) targets ligand-induced binding sites (LIBS) on the glycoprotein receptor GPIIb/IIIa, which is present on activated platelets. The immunoconjugates were radiolabeled with the positron-emitting isotope (64)Cu. The new radiolabeled conjugates were shown to bind selectively to activated platelets. The diagnostic potential of the most promising conjugate was demonstrated in an in vivo model of carotid artery thrombosis using positron emission tomography. This approach gives homogeneous products through site-specific enzyme-mediated conjugation and should be broadly applicable to other metal complexes and proteins.
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Affiliation(s)
- Brett M Paterson
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Vic (Australia)
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25
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Paterson BM, Alt K, Jeffery CM, Price RI, Jagdale S, Rigby S, Williams CC, Peter K, Hagemeyer CE, Donnelly PS. Enzyme-Mediated Site-Specific Bioconjugation of Metal Complexes to Proteins: Sortase-Mediated Coupling of Copper-64 to a Single-Chain Antibody. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201402613] [Citation(s) in RCA: 12] [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: 11/06/2022]
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26
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Newman J, Seabrook S, Surjadi R, Williams CC, Lucent D, Wilding M, Scott C, Peat TS. Determination of the structure of the catabolic N-succinylornithine transaminase (AstC) from Escherichia coli. PLoS One 2013; 8:e58298. [PMID: 23484010 PMCID: PMC3590144 DOI: 10.1371/journal.pone.0058298] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 02/01/2013] [Indexed: 11/18/2022] Open
Abstract
Escherichia coli possesses two acyl ornithine aminotransferases, one catabolic (AstC) and the other anabolic (ArgD), that participate in L-arginine metabolism. Although only 58% identical, the enzymes have been shown to be functionally interchangeable. Here we have purified AstC and have obtained X-ray crystal structures of apo and holo-AstC and of the enzyme complexed with its physiological substrate, succinylornithine. We compare the structures obtained in this study with those of ArgD from Salmonella typhimurium obtained elsewhere, finding several notable differences. Docking studies were used to explore the docking modes of several substrates (ornithine, succinylornithine and acetylornithine) and the co-substrate glutamate/α-ketogluterate. The docking studies support our observations that AstC has a strong preference for acylated ornithine species over ornithine itself, and suggest that the increase in specificity associated with acylation is caused by steric and desolvation effects rather than specific interactions between the substrate and enzyme.
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Affiliation(s)
- Janet Newman
- CSIRO Materials, Science and Engineering, Parkville, Australia
| | - Shane Seabrook
- CSIRO Materials, Science and Engineering, Parkville, Australia
| | - Regina Surjadi
- CSIRO Materials, Science and Engineering, Parkville, Australia
| | | | - Del Lucent
- CSIRO Materials, Science and Engineering, Parkville, Australia
| | | | - Colin Scott
- CSIRO Ecosystem Sciences, Canberra, Australia
| | - Thomas S. Peat
- CSIRO Materials, Science and Engineering, Parkville, Australia
- * E-mail:
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27
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Motyka M, Steer RP, Williams CC, Lee S, Ghiggino KP. Concerning the dual emission of porphyrazines employed in biomedical imaging. Photochem Photobiol Sci 2013; 12:1086-90. [DOI: 10.1039/c3pp50027f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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28
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Huderson BP, Duplessis TT, Williams CC, Seger HC, Marsden CG, Pouey KJ, Hill SM, Rowan BG. Stable inhibition of specific estrogen receptor α (ERα) phosphorylation confers increased growth, migration/invasion, and disruption of estradiol signaling in MCF-7 breast cancer cells. Endocrinology 2012; 153:4144-59. [PMID: 22733972 PMCID: PMC3423624 DOI: 10.1210/en.2011-2001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Elevated phosphorylation of estrogen receptor α (ERα) at serines 118 (S118) and 167 (S167) is associated with favorable outcome for tamoxifen adjuvant therapy and may serve as surrogate markers for a functional ERα signaling pathway in breast cancer. It is possible that loss of phosphorylation at S118 and/or S167 could disrupt ERα signaling, resulting in aggressive ERα-independent breast cancer cells. To this end, MCF-7 breast cancer cells were stably transfected with an ERα-specific short hairpin RNA that reduced endogenous ERα. The resulting cell line was stably transfected with wild-type ERα (ER-AB cells), or ERα containing serine to alanine mutation at S118 or S167 (S118A cells and S167A cells, respectively). These stable cell lines expressed approximately equivalent ERα compared with parental MCF-7 cells and were evaluated for growth, morphology, migration/invasion, and ERα-regulated gene expression. S118A cells and S167A cells exhibited increased growth and migration/invasion in vitro. Forward- and side-scatter flow cytometry revealed that S167A cells were smaller in size, and both S118A and S167A cells exhibited less cellular complexity. S118A and S167A cells expressed pancytokeratin and membrane localization of β-catenin and did not express vimentin, indicating retention of epithelial lineage markers. Expression of ERα-target genes and other genes regulated by ERα signaling or involved in breast cancer were markedly altered in both S118A and S167A cells. In summary, attenuated phosphorylation of ERα at S118 and S167 significantly affected cellular physiology and behavior in MCF-7 breast cancer cells, resulting in increased growth, migration/invasion, compromised expression of ERα target genes, and markedly altered gene expression patterns.
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Affiliation(s)
- B P Huderson
- Tulane University School of Medicine, Department of Structural and Cellular Biology, 1430 Tulane Avenue SL-49, New Orleans, Louisiana 70112, USA
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Williams CC, Thang SH, Hantke T, Vogel U, Seeberger PH, Tsanaktsidis J, Lepenies B. Inside Cover: RAFT-Derived Polymer-Drug Conjugates: Poly(hydroxypropyl methacrylamide) (HPMA)-7-Ethyl-10-hydroxycamptothecin (SN-38) Conjugates (ChemMedChem 2/2012). ChemMedChem 2012. [DOI: 10.1002/cmdc.201290001] [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: 11/08/2022]
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Madej MP, Coia G, Williams CC, Caine JM, Pearce LA, Attwood R, Bartone NA, Dolezal O, Nisbet RM, Nuttall SD, Adams TE. Engineering of an anti-epidermal growth factor receptor antibody to single chain format and labeling by sortase A-mediated protein ligation. Biotechnol Bioeng 2011; 109:1461-70. [DOI: 10.1002/bit.24407] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Revised: 11/15/2011] [Accepted: 11/30/2011] [Indexed: 11/11/2022]
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Williams CC, Thang SH, Hantke T, Vogel U, Seeberger PH, Tsanaktsidis J, Lepenies B. RAFT-Derived Polymer-Drug Conjugates: Poly(hydroxypropyl methacrylamide) (HPMA)-7-Ethyl-10-hydroxycamptothecin (SN-38) Conjugates. ChemMedChem 2011; 7:281-91. [DOI: 10.1002/cmdc.201100456] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 11/08/2011] [Indexed: 12/31/2022]
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Hong LPT, Scoble JA, Doughty L, Coia G, Williams CC. Cancer-targeting Antibody–Drug Conjugates: Site-specific Conjugation of Doxorubicin to Anti-EGFR 528 Fab' through a Polyethylene Glycol Linker. Aust J Chem 2011. [DOI: 10.1071/ch11071] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Antibody–drug conjugates have been prepared to examine the effect that attaching small-molecule drugs to an antibody fragment has on antibody activity. The anticancer drug doxorubicin was covalently attached through a polyethylene glycol linker to a cancer-targeting, anti-epidermal growth factor receptor antibody fragment (Fab′). The reactivity of maleimide was compared with a substituted maleimide derivative (citraconimide) in conjugation reactions with cysteine residues on a Fab′. Introduction of polyethylene glycol increased aqueous solubility of the cytotoxic drug, which led to an improvement in overall yield of the conjugation reaction with the antibody fragment. Antibody–drug conjugates prepared retained activity of the parent antibody, as determined by antigen binding experiments measured by surface plasmon resonance.
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Zheng N, Johnson JP, Williams CC, Wang G. Electronic characterization of individual monolayer protected Au clusters by single electron tunneling force spectroscopy. Nanotechnology 2010; 21:295708. [PMID: 20601769 DOI: 10.1088/0957-4484/21/29/295708] [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] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Gold monolayer protected clusters (MPCs) exhibit strong quantum confinement effects and size dependent electronic, optical and chemical properties. Chemical tuning of these properties can be achieved by established synthesis methods, providing an excellent system for the study of the relationship between chemical and electronic structure. In this paper, the first electronic spectra of individual Au MPCs (Au(25)) acquired by single electron tunneling force spectroscopy on non-conducting silicon dioxide surfaces are reported. A HOMO-LUMO (highest occupied molecular orbital-lowest unoccupied molecular orbital) energy gap is observed in the Au(25) spectra. Hysteretic charging of the particles is also observed while obtaining the energy spectra. The new single electron tunneling measurement methodology is described. A model explaining the measurements supports the existence of mid-HOMO-LUMO gap defect states.
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Affiliation(s)
- N Zheng
- Department of Physics, University of Utah, Salt Lake City, UT 84112, USA
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Moreira VR, Zeringue LK, Williams CC, Leonardi C, McCormick ME. Influence of calcium and phosphorus feeding on markers of bone metabolism in transition cows. J Dairy Sci 2009; 92:5189-98. [PMID: 19762837 DOI: 10.3168/jds.2009-2289] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A study was carried out to verify the effect of Ca and P levels on production, digestibility, and serum bone metabolism biomarkers in dairy cows. Fifty-two nonlactating multiparous cows (>or=3 lactations) were confined in a free-stall barn approximately 20 d before calving. A standard close-up diet was fed to cows once daily until d 2 postpartum. Cows were randomly assigned to 1 of 4 dietary treatments arranged in a 2 x 2 factorial approach averaging 0.64% Ca for high Ca (HCa), 0.46% Ca for low Ca (LCa), 0.47% P for high P (HP), and 0.38% P for low P (LP) on a dry matter basis. Experimental diets were fed twice daily from 3 d in milk (DIM) until 31 DIM. Intake and milk yield were recorded daily. Milk samples were collected on d 28, 29, and 30 postpartum for components analyses. Blood samples were drawn 10 d before expected calving, at calving, and at 15 and 30 DIM for serum analyses of osteocalcin, a biomarker of bone accretion, and pyridinoline, a biomarker of bone resorption. Total fecal collection was conducted when cows in a block averaged 20 DIM. Intake and production traits were not significantly affected by any of the dietary treatments. Cows averaged nearly 21 kg/d dry matter intake and 44 kg/d milk yield from 6 to 31 DIM. There were no significant differences across treatments in body weight or body condition score loss. Phosphorus intake, P fecal output, P digestibility, and P apparent absorption were affected by dietary P content. Calcium intake was higher with HCa, but Ca fecal output, digestibility, and apparent absorption showed an interaction between dietary Ca and dietary P. Calcium fecal output was 100.6 g/d for cows fed HCaHP, intermediate for cows on the HCaLP diet (89 g/d), and similar among cows fed the 2 LCa diets (70 g/d with LCaHP and 75 with LCaLP). There was no significant effect of Ca or P on osteocalcin measurements. Pyridinoline concentrations were affected by dietary Ca levels and tended to have a significant dietary Ca x dietary P interaction. Phosphorus apparent digestibility occurred independently of dietary Ca levels. Results of this study suggest that more bone was mobilized in cows fed LCa diets, but excess dietary P caused greater and prolonged bone mobilization regardless of dietary Ca content.
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Affiliation(s)
- V R Moreira
- Louisiana State University AgCenter Southeast Research Station, Franklinton 70438, USA.
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Baker MV, Brown DH, Haque RA, Simpson PV, Skelton BW, White AH, Williams CC. Mercury Complexes of N-Heterocyclic Carbenes Derived from Imidazolium-Linked Cyclophanes: Synthesis, Structure, and Reactivity. Organometallics 2009. [DOI: 10.1021/om8011745] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Murray V. Baker
- Chemistry M313, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - David H. Brown
- Chemistry M313, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, WA 6009, Australia
- Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, GPO Box U1987, Perth WA 6845, Australia
| | - Rosenani A. Haque
- Chemistry M313, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Peter V. Simpson
- Chemistry M313, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Brian W. Skelton
- Chemistry M313, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Allan H. White
- Chemistry M313, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Charlotte C. Williams
- Chemistry M313, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, WA 6009, Australia
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Johnson JP, Zheng N, Williams CC. Atomic scale imaging and spectroscopy of individual electron trap states using force detected dynamic tunnelling. Nanotechnology 2009; 20:055701. [PMID: 19417360 DOI: 10.1088/0957-4484/20/5/055701] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report the first atomic scale imaging and spectroscopic measurements of electron trap states in completely non-conducting surfaces by dynamic tunnelling force microscopy/spectroscopy. Single electrons are dynamically shuttled to/from individual states in thick films of hafnium silicate and silicon dioxide. The new method opens up surfaces that are inaccessible to the scanning tunnelling microscope for imaging and spectroscopy on an atomic scale.
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Affiliation(s)
- J P Johnson
- Department of Physics, University of Utah, Salt Lake City, UT 84112, USA
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Baker MV, Brown DH, Heath CH, Skelton BW, White AH, Williams CC. Azolium-Linked Cyclophanes: Effects of Structure, Solvent, and Counteranions on Solution Conformation Behavior. J Org Chem 2008; 73:9340-52. [DOI: 10.1021/jo801860d] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Murray V. Baker
- Chemistry M313, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, WA 6009, Australia, and Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, GPO Box U1987, Perth WA 6845, Australia
| | - David H. Brown
- Chemistry M313, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, WA 6009, Australia, and Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, GPO Box U1987, Perth WA 6845, Australia
| | - Charles H. Heath
- Chemistry M313, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, WA 6009, Australia, and Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, GPO Box U1987, Perth WA 6845, Australia
| | - Brian W. Skelton
- Chemistry M313, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, WA 6009, Australia, and Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, GPO Box U1987, Perth WA 6845, Australia
| | - Allan H. White
- Chemistry M313, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, WA 6009, Australia, and Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, GPO Box U1987, Perth WA 6845, Australia
| | - Charlotte C. Williams
- Chemistry M313, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, WA 6009, Australia, and Nanochemistry Research Institute, Department of Applied Chemistry, Curtin University of Technology, GPO Box U1987, Perth WA 6845, Australia
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Yau CMS, Pascu SI, Odom SA, Warren JE, Klotz EJF, Frampton MJ, Williams CC, Coropceanu V, Kuimova MK, Phillips D, Barlow S, Brédas JL, Marder SR, Millar V, Anderson HL. Stabilisation of a heptamethine cyanine dye by rotaxane encapsulation. Chem Commun (Camb) 2008:2897-9. [DOI: 10.1039/b802728e] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [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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Baker MV, Brown DH, Simpson PV, Skelton BW, White AH, Williams CC. Palladium, rhodium and platinum complexes of ortho-xylyl-linked bis-N-heterocyclic carbenes: Synthesis, structure and catalytic activity. J Organomet Chem 2006. [DOI: 10.1016/j.jorganchem.2006.09.037] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Chung YH, Bateman HG, Williams CC, Stanley CC, Gantt DT, Braud TW, Southern LL, Ward JD, Hoyt PG, Sod GA. Effects of Methionine and Lysine on Fermentation In Vitro and In Vivo, Nutrient Flow to the Intestine, and Milk Production. J Dairy Sci 2006; 89:1613-20. [PMID: 16606731 DOI: 10.3168/jds.s0022-0302(06)72228-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Three experiments were conducted to investigate the feasibility of using crystalline methionine and lysine as protein supplements for lactating Holstein cows. In the first experiment, Met (dl-methionine) and Lys (l-lysine-HCl) were added to diets used in continuous culture bioreactors to estimate optimal concentrations for use in subsequent in vivo experiments. The second experiment measured ruminal fermentation and nutrient flow to the small intestine when Met and Lys were top-dressed on diets fed to nonlactating cows. The third experiment measured lactation performance when Met and Lys were added to diets fed to late-lactation cows. Providing 0.29 and 2.27% of dry matter as Met and Lys, respectively, provided the largest improvement in fermentation in vitro and these concentrations were used in subsequent experiments. When Met and Lys were top-dressed on diets fed to nonlactating cows, no changes in total tract N digestion were observed. No changes in microbial protein production or ruminal fermentation were observed. Adding Met and Lys did not change production or efficiency of production of milk or milk components by late lactation cows. These data indicate that providing supplemental Met and Lys during late lactation does not significantly improve the protein status of the cow and therefore may not improve milk production.
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Affiliation(s)
- Y H Chung
- Louisiana State University AgCenter, Baton Rouge 70803, USA
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Baker MV, Bosnich MJ, Brown DH, Byrne LT, Hesler VJ, Skelton BW, White AH, Williams CC. Azolium-Linked Cyclophanes: A Comprehensive Examination of Conformations by 1H NMR Spectroscopy and Structural Studies. J Org Chem 2004; 69:7640-52. [PMID: 15497992 DOI: 10.1021/jo049097o] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis and characterization of a series of azolium-linked cyclophanes are reported. The cyclophanes consist of two azolium groups (17 examples) or three imidazolium groups (1 example) linked to two benzenoid units (benzene, naphthalene, p-xylene, mesitylene, 1,2,3,4- and 1,2,4,5-tetramethylbenzene, 2,6-pyridine, and p-tert-butylphenol) via methylene groups. Cyclophanes containing ortho-, meta-, and para-substitution patterns in the benzenoid units were examined. The conformations of the cyclophanes were examined in solution by variable-temperature NMR studies and in the solid state by crystallographic studies. The p-cyclophanes and mesitylene-based m- and o/m-cyclophanes are rigid on the NMR time scale, as indicated by sharp (1)H NMR spectra at all accessible temperatures. The non-mesitylene-based m-cyclophanes and the o-cyclophanes are fluxional on the NMR time scale at high temperatures, but in most cases, specific conformations can be "frozen out" at low temperatures. Many structures deduced from solution studies were consistent with those in the solid state.
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Affiliation(s)
- Murray V Baker
- Chemistry M313, The University of Western Australia, Crawley, WA 6009, Australia.
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Bateman HG, Williams CC, Gantt DT, Chung YH, Beem AE, Stanley CC, Goodier GE, Hoyt PG, Ward JD, Bunting LD. Effects of Zinc and Sodium Monensin on Ruminal Degradation of Lysine-HCl and Liquid 2-Hydroxy-4-Methylthiobutanoic Acid,. J Dairy Sci 2004; 87:2571-7. [PMID: 15328281 DOI: 10.3168/jds.s0022-0302(04)73382-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Four nonlactating, mature, Holstein cows were fitted with ruminal cannula and used in a 4 x 4 Latin square-designed experiment to evaluate the impact of supplemental Zn and monensin on ruminal degradation of Lys and liquid 2-hydroxy-4-methylthiobutanoic acid (HMB). Cows were fed 4.54 kg (as fed) of alfalfa hay top-dressed with 4.54 kg (as fed) concentrate once daily. Concentrates were formulated to provide 0 or 500 mg/kg of Zn as ZnSO4 and 0 or 40 mg/kg of monensin in the total diet. Zinc supplementation provided approximately 22-fold greater dietary Zn than estimated by NRC requirements. On d 14 of each period, cows were dosed via the rumen cannula with 50 g of HMB and 100 g of Lys-HCl, and the concentrations of Lys and HMB were monitored every 0.5 h for 8 h. Supplemental Zn tended to decrease the proportion of acetate in ruminal fluid postfeeding and increased the proportion of propionate in ruminal fluid postfeeding. Supplemental Zn increased mean fluid passage rate from the rumen. Monensin decreased the proportion of acetate and increased the mean proportion of propionate in ruminal fluid, resulting in a decrease in the ratio of acetate to propionate. Monensin also increased the mean fluid passage rate from the rumen. Neither Zn nor monensin affected the apparent rate of ruminal disappearance of HMB or Lys. However, Zn and monensin interacted to alter the ruminal degradability of free Lys but not HMB. These data indicate that Zn and monensin may interact to alter ruminal degradability of free amino acids.
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Affiliation(s)
- H G Bateman
- Department of Dairy Science, LSU Agricultural Center, Louisiana State University and A & M College, Baton Rouge 70803, USA.
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Walz LS, Ellis WC, White TW, Matis JH, Bateman HG, Williams CC, Fernandez JM, Gentry LR. Flow paths of plant tissue residues and digesta through gastrointestinal segments in Spanish goats and methodological considerations1. J Anim Sci 2004; 82:508-20. [PMID: 14974550 DOI: 10.2527/2004.822508x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A sequence of eight twice-daily meals, each marked with different rare earth elements, was fed to 24 Spanish goats (BW = 20.6 +/- 1.94 kg) to produce meal-based profiles of rare earth markers within segments of the gastrointestinal digesta on subsequent slaughter. Accumulative mean residence time and time delay of rare earths and segmental and accumulative mean residence times of indigestible NDF (IDF) were estimated for each sampled segment. Diets consisted of ad libitum access to bermudagrass hay with a limit feeding of one of four supplements: 1) minerals (basal, B); 2) B + energy (E); 3) B + CP (CP); or 4) B + E + CP for 84 d. Mean daily intake (g/kg of BW) during the 5 d before slaughter differed (P < 0.05) via diet for DM but not for IDF (8.0 +/- 0.35 g/kg of BW). Larger estimates of cumulative mean residence time for IDF vs. rare earths were suggested to be the consequence of a meal-induced bias in the single measurement of IDF pool size by anatomical site. The rare earth compartment method was considered more reliable than the IDF pool dilution method because it yielded flow estimates based on the flux of eight meal-dosed rare earth markers over 4 d and was independent of anatomical definitions of pool size. Statistically indistinguishable estimates for gastrointestinal mean residence times for IDF and rare earths conform to assumed indelibility for the specifically applied rare earths and indigestibility of IDF. The potentially digestible NDF (PDF):IDF ratio of dietary fragments (0.8) progressively decreased in the following order: caudodorsal reticulorumen (0.390) > crainodorsal reticulorumen (0.357) approximately reticulum (0.354) > mid-dorsal reticulorumen (0.291) approximately ventral reticulorumen (0.286), to that within the omasal folds and in the abomasum (0.259). Such a gradient of progressively aging mixture of plant tissue fragments is consistent with age-dependent flow paths established in the reticulorumen and flowing to the omasum and abomasum. Such heterogeneity of fragment ages within the reticulorumen is also indicated by the superior fit of marker dose site double dagger marker sampling site model assumptions. Additionally, cyclic meal- and rumination-induced variations in escape rate occur. Estimates of mean escape rates over days, needed for the practice of ruminant nutrition, must consider the complex interactions among plant tissues and the dynamics of their ruminal digestion of PDF.
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Affiliation(s)
- L S Walz
- Louisiana State University Agricultural Center, Baton Rouge 70803-4210, USA
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Pruett HE, Thompson DL, Cartmill JA, Williams CC, Gentry LR. Thyrotropin releasing hormone interactions with growth hormone secretion in horses. J Anim Sci 2003; 81:2343-51. [PMID: 12968710 DOI: 10.2527/2003.8192343x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Light horse mares, stallions, and geldings were used to 1) extend our observations on the thyrotropin releasing hormone (TRH) inhibition of GH secretion in response to physiologic stimuli and 2) test the hypothesis that stimulation of endogenous TRH would decrease the normal rate of GH secretion. In Exp. 1 and 2, pretreatment of mares with TRH (10 microg/kg BW) decreased (P < 0.001) the GH response to exercise and aspartate infusion. Time analysis in Exp. 3 indicated that the TRH inhibition lasted at least 60 min but was absent by 120 min. Administration of a single injection of TRH to stallions in Exp. 4 increased (P < 0.001) prolactin concentrations as expected but had no effect (P > 0.10) on GH concentrations. Similarly, 11 hourly injections of TRH administered to geldings in Exp. 5 did not alter (P > 0.10) GH concentrations either during the injections or for the next 14 h. In Exp. 5, it was noted that the prolactin and thyroid-stimulating hormone responses to TRH were great (P < 0.001) for the first injection, but subsequent injections had little to no stimulatory effect. Thus, Exp. 6 was designed to determine whether the inhibitory effect of TRH also waned after multiple injections. Geldings pretreated with five hourly injections of TRH had an exercise-induced GH response identical to that of control geldings, indicating that the inhibitory effect was absent after five TRH injections. Retrospective analysis of pooled, selected data from Exp. 4, 5, and 6 indicated that endogenous GH concentrations were in fact lower (P < 0.01) from 45 to 75 min after TRH injection but not thereafter. In Exp. 7, 6-n-propyl-2-thiouracil was fed to stallions to reduce thyroid activity and hence thyroid hormone feedback, potentially increasing endogenous TRH secretion. Treated stallions had decreased (P < 0.01) concentrations of thyroxine and elevated (P < 0.01) concentrations of thyroid-stimulating hormone by d 52 of feeding, but plasma concentrations of GH and prolactin were unaffected (P > 0.10). In contrast, the GH response to aspartate and the prolactin response to sulpiride were greater (P < 0.05) in treated stallions than in controls. In summary, TRH inhibited exercise- and aspartate-induced GH secretion. The duration of the inhibition was at least 1 h but less than 2 h, and it waned with multiple injections. There is likely a TRH inhibition of endogenous GH episodes as well. Reduced thyroid feedback on the hypothalamic-pituitary axis did not alter basal GH and prolactin secretion.
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Affiliation(s)
- H E Pruett
- Department of Animal Sciences, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge 70803-4210, USA
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Stanley CC, Williams CC, Jenny BF, Fernandez JM, Bateman HG, Nipper WA, Lovejoy JC, Gantt DT, Goodier GE. Effects of feeding milk replacer once versus twice daily on glucose metabolism in Holstein and Jersey calves. J Dairy Sci 2002; 85:2335-43. [PMID: 12362466 DOI: 10.3168/jds.s0022-0302(02)74313-0] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Eighteen Holstein (experiment 1) and 15 Jersey (experiment 2) heifer calves were fed milk replacer once or twice daily to determine effects of feeding frequency on weight gain, starter intake, and glucose metabolism. Body weights were measured weekly from birth to 8 wk. Blood samples were collected at wk 1 through 6 from all calves before and at 30, 60, 90, 120 and 180 min after the morning feeding. Plasma was analyzed for glucose, insulin, glucagon, and nonesterified fatty acids (NEFA). Urine was collected 90 min postfeeding to measure glucose concentration. Treatment did not affect mean starter intake or body weight. In experiments 1 and 2 mean plasma glucagon, glucose, NEFA, and insulin and urinary glucose concentrations were not affected by treatment. There was an interaction of sampling time and treatment for plasma insulin concentrations but not for glucose concentrations in both experiments. Following feeding, calves fed milk replacer once daily had higher insulin concentrations than those fed twice daily. There was an interaction of sampling time and treatment for plasma NEFA concentrations in Jersey calves only. Jersey calves fed milk replacer once daily had higher plasma NEFA concentrations before the morning milk replacer feeding. At wk 3 and 6, frequently sampled intravenous glucose tolerance tests were performed to assess glucose effectiveness, insulin sensitivity, and acute insulin response. In experiments 1 and 2 glucose effectiveness and insulin sensitivity were similar regardless of milk replacer feeding frequency. In Holstein and Jersey calves fed milk replacer twice daily, acute insulin response was greater than in calves fed once daily. However, insulin sensitivity decreased with age, while acute insulin response increased with age. These data suggest that feeding calves milk replacer once daily did not deleteriously affect performance or glucose metabolism regardless of breed.
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Affiliation(s)
- C C Stanley
- Department of Dairy Science, Louisiana State University Agricultural Center, Louisiana Agricultural Experiment Station, Baton Rouge 70803, USA
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Baker MV, Skelton BW, White AH, Williams CC. Synthesis and Characterization of a Saddle-Shaped Nickel−Carbene Complex Derived from an Imidazolium-Linked meta-Cyclophane. Organometallics 2002. [DOI: 10.1021/om011031l] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Murray V. Baker
- Department of Chemistry, The University of Western Australia, Crawley, WA 6009, Australia
| | - Brian W. Skelton
- Department of Chemistry, The University of Western Australia, Crawley, WA 6009, Australia
| | - Allan H. White
- Department of Chemistry, The University of Western Australia, Crawley, WA 6009, Australia
| | - Charlotte C. Williams
- Department of Chemistry, The University of Western Australia, Crawley, WA 6009, Australia
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Williams CC, Zacks RT. Is retrieval-induced forgetting an inhibitory process? Am J Psychol 2002; 114:329-54. [PMID: 11641884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Three experiments investigated memory performance in the retrieval practice paradigm (Anderson, Bjork, & Bjork, 1994; Anderson & Spellman, 1995). This paradigm produces a retrieval-induced forgetting effect, wherein practicing some members of a studied category decreases the recall of other members of that category relative to a baseline. Our findings indicate that the retrieval-induced forgetting effect is replicable but that previous findings supporting an inhibitory account of this phenomenon may not be.
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Affiliation(s)
- C C Williams
- Department of Psychology, Michigan State University, East Lansing, MI 48824-1117, USA.
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Abstract
Retrieving some members of a memory set impairs later recall of semantically related but not unrelated members (M. C. Anderson, R. A. Bjork, & E. L. Bjork, 1994; M. C. Anderson & B. A. Spellman, 1995). The authors investigated whether this retrieval-induced forgetting effect would generalize to testing procedures other than category-cued recall. Although the authors demonstrated a retrieval-induced forgetting effect using a category-cued recall task, they failed to show retrieval-induced forgetting on several different memory tests that used item-specific cues, including a category-plus-stem-cued recall test, a category-plus-fragment-cued recall test, a fragment-cued recall test, and a fragment completion task.
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Affiliation(s)
- K M Butler
- Department of Psychology, Michigan State University, East Lansing 48824, USA.
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Williams CC, Cummins KA, Hayek MG, Davenport GM. Effects of dietary protein on whole-body protein turnover and endocrine function in young-adult and aging dogs. J Anim Sci 2001; 79:3128-36. [PMID: 11811469 DOI: 10.2527/2001.79123128x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Thirty-six adult female Beagles averaging 2 (young-adult) or 8 (geriatric) yr of age were used to assess the effects of graded levels of dietary protein (16, 24, or 32%) on endocrine-controlled regulation of whole-body protein turnover. Rates of whole-body protein synthesis (WBPS) and whole-body protein degradation (WBPD) were estimated using orally administered 15N-glycine and total excreta collection. Although N balance was similar for all dogs, N flux through the metabolic pool increased linearly (P < 0.05) as protein intake increased. Rates of WBPS, WBPD, or the difference between them were not influenced by age (P > 0.10). A quadratic increase (P < 0.05) in WBPS and WBPD was observed in response to dietary protein. Serum insulin-like growth factor-I (IGF-I), IGF-I-binding protein 3, and total IGF-I-binding proteins were higher (P < 0.05) in geriatric dogs than in young-adult dogs regardless of protein intake. These results indicate that dietary protein in excess of 16% may not be required to maintain N balance in young-adult and aging dogs despite the linear increase in N flux through the metabolic pool. Furthermore, age-induced changes in endocrine functionality may differ between dogs and other species.
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Affiliation(s)
- C C Williams
- Department of Animal and Dairy Sciences, Auburn University, AL 36849, USA
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Hollingworth A, Williams CC, Henderson JM. To see and remember: visually specific information is retained in memory from previously attended objects in natural scenes. Psychon Bull Rev 2001; 8:761-8. [PMID: 11848597 DOI: 10.3758/bf03196215] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
What is the nature of the representation formed during the viewing of natural scenes? We tested two competing hypotheses regarding the accumulation of visual information during scene viewing. The first holds that coherent visual representations disintegrate as soon as attention is withdrawn from an object and thus that the visual representation of a scene is exceedingly impoverished. The second holds that visual representations do not necessarily decay upon the withdrawal of attention, but instead can be accumulated in memory from previously attended regions. Target objects in line drawings of natural scenes were changed during a saccadic eye movement away from those objects. Three findings support the second hypothesis. First, changes to the visual form of target objects (token substitution) were successfully detected, as indicated by both explicit and implicit measures, even though the target object was not attended when the change occurred. Second, these detections were often delayed until well after the change. Third, changes to semantically inconsistent target objects were detected better than changes to semantically consistent objects.
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