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Deore P, Tsang Min Ching SJ, Nitschke MR, Rudd D, Brumley DR, Hinde E, Blackall LL, van Oppen MJH. Unique photosynthetic strategies employed by closely related Breviolum minutum strains under rapid short-term cumulative heat stress. J Exp Bot 2024:erae170. [PMID: 38636949 DOI: 10.1093/jxb/erae170] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Indexed: 04/20/2024]
Abstract
The thermal tolerance of symbiodiniacean photo-endosymbionts largely underpins the thermal bleaching resilience of their cnidarian hosts such as corals and the coral model, Exaiptasia diaphana. While variation in thermal tolerance between species is well documented, variation between conspecific strains is understudied. We compared the thermal tolerance of three closely related strains of Breviolum minutum represented by two internal transcribed spacer region 2 profiles (one strain B1-B1o-B1g-B1p and the other two strains B1-B1a-B1b-1g) and differences in photochemical and non-photochemical quenching, de-epoxidation state of photopigments, and accumulation of reactive oxygen species under rapid short-term cumulative temperature stress (26-40°C). We found that B. minutum strains employ distinct photoprotective strategies, resulting in different upper thermal tolerances. We provide evidence for previously unknown interdependencies between thermal tolerance traits and photoprotective mechanisms which include a delicate balancing of excitation energy and its dissipation through fast relaxing and state transition components of non-photochemical quenching. The more thermally tolerant B. minutum strain (B1-B1o-B1g-B1p) exhibited an enhanced de-epoxidation that is strongly linked to the thylakoid membrane melting point and possibly membrane rigidification minimising oxidative damage. This study provides an in-depth understanding of photoprotective mechanisms underpinning thermal tolerance in closely related strains of B. minutum.
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Affiliation(s)
- Pranali Deore
- School of BioSciences, The University of Melbourne, Parkville 3010, Victoria, Australia
| | | | - Matthew R Nitschke
- Australian Institute of Marine Science, Townsville 4810, Queensland, Australia
- School of Biological Sciences, Victoria University of Wellington, Wellington 6102, New Zealand
| | - David Rudd
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Douglas R Brumley
- School of Mathematics and Statistics, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Elizabeth Hinde
- School of Physics, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Linda L Blackall
- School of BioSciences, The University of Melbourne, Parkville 3010, Victoria, Australia
| | - Madeleine J H van Oppen
- School of BioSciences, The University of Melbourne, Parkville 3010, Victoria, Australia
- Australian Institute of Marine Science, Townsville 4810, Queensland, Australia
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2
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Chan WY, Meyers L, Rudd D, Topa SH, van Oppen MJH. Heat-evolved algal symbionts enhance bleaching tolerance of adult corals without trade-off against growth. Glob Chang Biol 2023; 29:6945-6968. [PMID: 37913765 DOI: 10.1111/gcb.16987] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 09/11/2023] [Accepted: 10/01/2023] [Indexed: 11/03/2023]
Abstract
Ocean warming has caused coral mass bleaching and mortality worldwide and the persistence of symbiotic reef-building corals requires rapid acclimation or adaptation. Experimental evolution of the coral's microalgal symbionts followed by their introduction into coral is one potential method to enhance coral thermotolerance. Heat-evolved microalgal symbionts of the generalist species, Cladocopium proliferum (strain SS8), were exposed to elevated temperature (31°C) for ~10 years, and were introduced into four genotypes of chemically bleached adult fragments of the scleractinian coral, Galaxea fascicularis. Two of the four coral genotypes acquired SS8. The new symbionts persisted for the 5 months of the experiment and enhanced adult coral thermotolerance, compared with corals that were inoculated with the wild-type C. proliferum strain. Thermotolerance of SS8-corals was similar to that of coral fragments from the same colony hosting the homologous symbiont, Durusdinium sp., which is naturally heat tolerant. However, SS8-coral fragments exhibited faster growth and recovered cell density and photochemical efficiency more quickly following chemical bleaching and inoculation under ambient temperature relative to Durusdinium-corals. Mass spectrometry imaging suggests that algal pigments involved in photobiology and oxidative stress were the greatest contributors to the thermotolerance differences between coral hosting heat-evolved versus wild-type C. proliferum. These pigments may have increased photoprotection in the heat-evolved symbionts. This is the first laboratory study to show that thermotolerance of adult corals (G. fascicularis) can be enhanced via the uptake of exogenously supplied, heat-evolved symbionts, without a trade-off against growth under ambient temperature. Importantly, heat-evolved C. proliferum remained in the corals in moderate abundance 2 years after first inoculation, suggesting long-term stability of this novel symbiosis and potential long-term benefits to coral thermotolerance.
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Affiliation(s)
- Wing Yan Chan
- School of BioSciences, University of Melbourne, Parkville, Victoria, Australia
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - Luka Meyers
- School of BioSciences, University of Melbourne, Parkville, Victoria, Australia
| | - David Rudd
- Monash Institute of Pharmaceutical Sciences, Parkville, Victoria, Australia
- Melbourne Centre for Nanofabrication, Clayton, Victoria, Australia
| | - Sanjida H Topa
- School of BioSciences, University of Melbourne, Parkville, Victoria, Australia
| | - Madeleine J H van Oppen
- School of BioSciences, University of Melbourne, Parkville, Victoria, Australia
- Australian Institute of Marine Science, Townsville, Queensland, Australia
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3
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Krishnan ST, Winkler D, Creek D, Anderson D, Kirana C, Maddern GJ, Fenix K, Hauben E, Rudd D, Voelcker NH. Staging of colorectal cancer using lipid biomarkers and machine learning. Metabolomics 2023; 19:84. [PMID: 37731020 PMCID: PMC10511619 DOI: 10.1007/s11306-023-02049-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 09/07/2023] [Indexed: 09/22/2023]
Abstract
INTRODUCTION Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide. Alteration in lipid metabolism and chemokine expression are considered hallmark characteristics of malignant progression and metastasis of CRC. Validated diagnostic and prognostic biomarkers are urgently needed to define molecular heterogeneous CRC clinical stages and subtypes, as liver dominant metastasis has poor survival outcomes. OBJECTIVES The aim of this study was to integrate lipid changes, concentrations of chemokines, such as platelet factor 4 and interleukin 8, and gene marker status measured in plasma samples, with clinical features from patients at different CRC stages or who had progressed to stage-IV colorectal liver metastasis (CLM). METHODS High-resolution liquid chromatography-mass spectrometry (HR-LC-MS) was used to determine the levels of candidate lipid biomarkers in each CRC patient's preoperative plasma samples and combined with chemokine, gene and clinical data. Machine learning models were then trained using known clinical outcomes to select biomarker combinations that best classify CRC stage and group. RESULTS Bayesian neural net and multilinear regression-machine learning identified candidate biomarkers that classify CRC (stages I-III), CLM patients and control subjects (cancer-free or patients with polyps/diverticulitis), showing that integrating specific lipid signatures and chemokines (platelet factor-4 and interluken-8; IL-8) can improve prognostic accuracy. Gene marker status could contribute to disease prediction, but requires ubiquitous testing in clinical cohorts. CONCLUSION Our findings demonstrate that correlating multiple disease related features with lipid changes could improve CRC prognosis. The identified signatures could be used as reference biomarkers to predict CRC prognosis and classify stages, and monitor therapeutic intervention.
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Affiliation(s)
- Sanduru Thamarai Krishnan
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
- Department of Chemistry, University of Reading, Whiteknights, Reading, RG6 6DX, UK
- Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, 151 Wellington Road, Clayton, VIC, 3168, Australia
| | - David Winkler
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, 3086, Australia
- School of Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
- School of Pharmacy, University of Nottingham, Nottingham, NG7 2QL, UK
| | - Darren Creek
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
- Monash Proteomics and Metabolomics Facility, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Dovile Anderson
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
- Monash Proteomics and Metabolomics Facility, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Chandra Kirana
- Discipline of Surgery, Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
- Basil Hetzel Institute for Translational Health Research, The Queen Elizabeth Hospital, Woodville, SA, 5011, Australia
| | - Guy J Maddern
- Discipline of Surgery, Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
- Basil Hetzel Institute for Translational Health Research, The Queen Elizabeth Hospital, Woodville, SA, 5011, Australia
| | - Kevin Fenix
- Discipline of Surgery, Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
- Basil Hetzel Institute for Translational Health Research, The Queen Elizabeth Hospital, Woodville, SA, 5011, Australia
| | - Ehud Hauben
- Discipline of Surgery, Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
- Basil Hetzel Institute for Translational Health Research, The Queen Elizabeth Hospital, Woodville, SA, 5011, Australia
| | - David Rudd
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia.
- Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, 151 Wellington Road, Clayton, VIC, 3168, Australia.
| | - Nicolas Hans Voelcker
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia.
- Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, 151 Wellington Road, Clayton, VIC, 3168, Australia.
- Commonwealth Scientific and Industrial Research Organization (CSIRO), Clayton, VIC, 3168, Australia.
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Chan WY, Rudd D, van Oppen MJ. Spatial metabolomics for symbiotic marine invertebrates. Life Sci Alliance 2023; 6:e202301900. [PMID: 37202120 PMCID: PMC10200813 DOI: 10.26508/lsa.202301900] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 05/10/2023] [Accepted: 05/10/2023] [Indexed: 05/20/2023] Open
Abstract
Microbial symbionts frequently localize within specific body structures or cell types of their multicellular hosts. This spatiotemporal niche is critical to host health, nutrient exchange, and fitness. Measuring host-microbe metabolite exchange has conventionally relied on tissue homogenates, eliminating dimensionality and dampening analytical sensitivity. We have developed a mass spectrometry imaging workflow for a soft- and hard-bodied cnidarian animal capable of revealing the host and symbiont metabolome in situ, without the need for a priori isotopic labelling or skeleton decalcification. The mass spectrometry imaging method provides critical functional insights that cannot be gleaned from bulk tissue analyses or other presently available spatial methods. We show that cnidarian hosts may regulate microalgal symbiont acquisition and rejection through specific ceramides distributed throughout the tissue lining the gastrovascular cavity. The distribution pattern of betaine lipids showed that once resident, symbionts primarily reside in light-exposed tentacles to generate photosynthate. Spatial patterns of these metabolites also revealed that symbiont identity can drive host metabolism.
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Affiliation(s)
- Wing Yan Chan
- School of BioSciences, University of Melbourne, Parkville, Australia
- Australian Institute of Marine Science, Townsville, Australia
| | - David Rudd
- Monash Institute of Pharmaceutical Sciences, Parkville, Australia
- Melbourne Centre for Nanofabrication, Clayton, Australia
| | - Madeleine Jh van Oppen
- School of BioSciences, University of Melbourne, Parkville, Australia
- Australian Institute of Marine Science, Townsville, Australia
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5
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Tong Z, Esser L, Galettis P, Rudd D, Easton CD, Nilghaz A, Peng B, Zhu D, Thissen H, Martin JH, Voelcker NH. Fluoropolymer Functionalization of Organ-on-Chip Platform Increases Detection Sensitivity for Cannabinoids. Biosensors (Basel) 2023; 13:779. [PMID: 37622865 PMCID: PMC10452156 DOI: 10.3390/bios13080779] [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: 06/18/2023] [Revised: 07/25/2023] [Accepted: 07/28/2023] [Indexed: 08/26/2023]
Abstract
Microfluidic technology is applied across various research areas including organ-on-chip (OOC) systems. The main material used for microfluidics is polydimethylsiloxane (PDMS), a silicone elastomer material that is biocompatible, transparent, and easy to use for OOC systems with well-defined microstructures. However, PDMS-based OOC systems can absorb hydrophobic and small molecules, making it difficult and erroneous to make quantitative analytical assessments for such compounds. In this paper, we explore the use of a synthetic fluoropolymer, poly(4,5-difluoro-2,2-bis(trifluoromethyl)-1,3-dioxole-co-tetrafluoroethylene) (Teflon™ AF 2400), with excellent "non-stick" properties to functionalize OOC systems. Cannabinoids, including cannabidiol (CBD), are classes of hydrophobic compounds with a great potential for the treatment of anxiety, depression, pain, and cancer. By using CBD as a testing compound, we examined and systematically quantified CBD absorption into PDMS by means of an LC-MS/MS analysis. In comparison to the unmodified PDMS microchannels, an increase of approximately 30× in the CBD signal was detected with the fluoropolymer surface modification after 3 h of static incubation. Under perfusion conditions, we observed an increase of nearly 15× in the CBD signals from the surface-modified microchannels than from the unmodified microchannels. Furthermore, we also demonstrated that fluoropolymer-modified microchannels are compatible for culturing hCMEC/D3 endothelial cells and for CBD perfusion experiments.
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Affiliation(s)
- Ziqiu Tong
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia; (Z.T.); (D.R.); (A.N.); (B.P.); (D.Z.)
| | - Lars Esser
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton, VIC 3168, Australia; (L.E.); (C.D.E.); (H.T.)
| | - Peter Galettis
- Centre for Drug Repurposing & Medicines Research, School of Medicine and Public Health, Faculty of Health, Medicine & Wellbeing, The University of Newcastle, Callaghan, NSW 2308, Australia;
- Centre Hunter Medical Research Institute, New Lambton Heights, NSW 2305, Australia
| | - David Rudd
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia; (Z.T.); (D.R.); (A.N.); (B.P.); (D.Z.)
| | - Christopher D. Easton
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton, VIC 3168, Australia; (L.E.); (C.D.E.); (H.T.)
| | - Azadeh Nilghaz
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia; (Z.T.); (D.R.); (A.N.); (B.P.); (D.Z.)
- Institute for Frontier Materials, Deakin University, Waurn Pounds, VIC 3216, Australia
| | - Bo Peng
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia; (Z.T.); (D.R.); (A.N.); (B.P.); (D.Z.)
- Xi’an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, Xi’an 710072, China
| | - Douer Zhu
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia; (Z.T.); (D.R.); (A.N.); (B.P.); (D.Z.)
| | - Helmut Thissen
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton, VIC 3168, Australia; (L.E.); (C.D.E.); (H.T.)
| | - Jennifer H. Martin
- Centre for Drug Repurposing & Medicines Research, School of Medicine and Public Health, Faculty of Health, Medicine & Wellbeing, The University of Newcastle, Callaghan, NSW 2308, Australia;
- Centre Hunter Medical Research Institute, New Lambton Heights, NSW 2305, Australia
| | - Nicolas H. Voelcker
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia; (Z.T.); (D.R.); (A.N.); (B.P.); (D.Z.)
- Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton, VIC 3168, Australia
- Materials Science and Engineering, Monash University, Clayton, VIC 3168, Australia
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Kaur I, Tieu T, Deepagan VG, Ali MA, Alsunaydih F, Rudd D, Moghaddam MA, Bourgeois L, Adams TE, Thurecht KJ, Yuce M, Cifuentes-Rius A, Voelcker NH. Combination of Chemotherapy and Mild Hyperthermia Using Targeted Nanoparticles: A Potential Treatment Modality for Breast Cancer. Pharmaceutics 2023; 15:pharmaceutics15051389. [PMID: 37242631 DOI: 10.3390/pharmaceutics15051389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/17/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
Despite the clinical benefits that chemotherapeutics has had on the treatment of breast cancer, drug resistance remains one of the main obstacles to curative cancer therapy. Nanomedicines allow therapeutics to be more targeted and effective, resulting in enhanced treatment success, reduced side effects, and the possibility of minimising drug resistance by the co-delivery of therapeutic agents. Porous silicon nanoparticles (pSiNPs) have been established as efficient vectors for drug delivery. Their high surface area makes them an ideal carrier for the administration of multiple therapeutics, providing the means to apply multiple attacks to the tumour. Moreover, immobilising targeting ligands on the pSiNP surface helps direct them selectively to cancer cells, thereby reducing harm to normal tissues. Here, we engineered breast cancer-targeted pSiNPs co-loaded with an anticancer drug and gold nanoclusters (AuNCs). AuNCs have the capacity to induce hyperthermia when exposed to a radiofrequency field. Using monolayer and 3D cell cultures, we demonstrate that the cell-killing efficacy of combined hyperthermia and chemotherapy via targeted pSiNPs is 1.5-fold higher than applying monotherapy and 3.5-fold higher compared to using a nontargeted system with combined therapeutics. The results not only demonstrate targeted pSiNPs as a successful nanocarrier for combination therapy but also confirm it as a versatile platform with the potential to be used for personalised medicine.
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Affiliation(s)
- Ishdeep Kaur
- Monash Institute of Pharmacy and Pharmaceutical Sciences, Monash University, 381, Royal Parade, Parkville, VIC 3052, Australia
| | - Terence Tieu
- Monash Institute of Pharmacy and Pharmaceutical Sciences, Monash University, 381, Royal Parade, Parkville, VIC 3052, Australia
| | - Veerasikku G Deepagan
- Monash Institute of Pharmacy and Pharmaceutical Sciences, Monash University, 381, Royal Parade, Parkville, VIC 3052, Australia
| | - Muhammad A Ali
- Department of Electrical and Computer Systems Engineering, Monash University, Clayton Campus, Clayton, VIC 3168, Australia
| | - Fahad Alsunaydih
- Department of Electrical and Computer Systems Engineering, Monash University, Clayton Campus, Clayton, VIC 3168, Australia
| | - David Rudd
- Monash Institute of Pharmacy and Pharmaceutical Sciences, Monash University, 381, Royal Parade, Parkville, VIC 3052, Australia
| | - Maliheh A Moghaddam
- Centre of Polymer Systems, Tomas Bata University, 5678, 760 01 Zlin, Czech Republic
| | - Laure Bourgeois
- Monash Centre for Electron Microscopy, Clayton Campus, Monash University, Clayton, VIC 3168, Australia
| | - Timothy E Adams
- Commonwealth Scientific and Industrial Research Organization (CSIRO), 343, Royal Parade, Parkville, VIC 3052, Australia
| | - Kristofer J Thurecht
- Australian Institute for Bioengineering and Nanotechnology (AIBN), Corner College and Cooper Rds, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Mehmet Yuce
- Department of Electrical and Computer Systems Engineering, Monash University, Clayton Campus, Clayton, VIC 3168, Australia
| | - Anna Cifuentes-Rius
- Monash Institute of Pharmacy and Pharmaceutical Sciences, Monash University, 381, Royal Parade, Parkville, VIC 3052, Australia
| | - Nicolas H Voelcker
- Monash Institute of Pharmacy and Pharmaceutical Sciences, Monash University, 381, Royal Parade, Parkville, VIC 3052, Australia
- Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton, VIC 3168, Australia
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Lu J, Zhu Y, Parkington HC, Hussein M, Zhao J, Bergen P, Rudd D, Deane MA, Oberrauch S, Cornthwaite-Duncan L, Allobawi R, Sharma R, Rao G, Li J, Velkov T. Transcriptomic Mapping of Neurotoxicity Pathways in the Rat Brain in Response to Intraventricular Polymyxin B. Mol Neurobiol 2023; 60:1317-1330. [PMID: 36443617 DOI: 10.1007/s12035-022-03140-7] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 11/17/2022] [Indexed: 11/30/2022]
Abstract
Intraventricular or intrathecal administration of polymyxins are increasingly used to treat multidrug-resistant (MDR) Gram-negative bacteria caused infections in the central nervous system (CNS). However, our limited knowledge of the mechanisms underpinning polymyxin-induced neurotoxicity significantly hinders the development of safe and efficacious polymyxin dosing regimens. To this end, we conducted transcriptomic analyses of the rat brain and spinal cord 1 h following intracerebroventricular administration of polymyxin B into rat lateral ventricle at a clinically relevant dose (0.5 mg/kg). Following the treatment, 66 differentially expressed genes (DEGs) were identified in the brain transcriptome while none for the spinal cord (FDR ≤ 0.05, fold-change ≥ 1.5). DEGs were enriched in signaling pathways associated with hormones and neurotransmitters, including dopamine and (nor)epinephrine. Notably, the expression levels of Slc6a3 and Gabra6 were decreased by 20-fold and 4.3-fold, respectively, likely resulting in major perturbations of dopamine and γ-aminobutyric acid signaling in the brain. Mass spectrometry imaging of brain sections revealed a distinct pattern of polymyxin B distribution with the majority accumulating in the injection-side lateral ventricle and subsequently into third and fourth ventricles. Polymyxin B was not detectable in the left lateral ventricle or brain tissue. Electrophysiological measurements on primary cultured rat neurons revealed a large inward current and significant membrane leakage following polymyxin B treatment. Our work demonstrates, for the first time, the key CNS signaling pathways associated with polymyxin neurotoxicity. This mechanistic insight combined with pharmacokinetic/pharmacodynamic dosing strategies will help guide the design of safe and effective intraventricular/intrathecal polymyxin treatment regimens for CNS infections caused by MDR Gram-negative pathogens.
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Affiliation(s)
- Jing Lu
- Department of Pharmacology & Biochemistry, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia.,Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
| | - Yan Zhu
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
| | - Helena C Parkington
- Department of Physiology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
| | - Maytham Hussein
- Department of Pharmacology & Biochemistry, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia.,Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
| | - Jinxin Zhao
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
| | - Phillip Bergen
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
| | - David Rudd
- Drug Delivery, Disposition and Dynamics, Faculty of Pharmacy and Pharmaceutical Sciences, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, 3010, Australia
| | - Mary A Deane
- Department of Physiology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
| | - Sara Oberrauch
- Department of Pharmacology & Biochemistry, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Linda Cornthwaite-Duncan
- Department of Pharmacology & Biochemistry, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Rafah Allobawi
- Department of Pharmacology & Biochemistry, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia.,Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
| | - Rajnikant Sharma
- UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27514, USA
| | - Gauri Rao
- UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27514, USA.
| | - Jian Li
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia.
| | - Tony Velkov
- Department of Pharmacology & Biochemistry, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia. .,Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia.
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Mahbub P, Hasan CK, Rudd D, Voelcker NH, Orbell J, Cole I, Macka M. Rapid and selective screening of organic peroxide explosives using acid-hydrolysis induced chemiluminescence. Anal Chim Acta 2023; 1255:341156. [PMID: 37032060 DOI: 10.1016/j.aca.2023.341156] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 02/22/2023] [Accepted: 03/27/2023] [Indexed: 03/30/2023]
Abstract
Organic peroxide explosives (OPEs) are unstable, non-military, contemporary security threats often found in improvised explosive devices. Chemiluminescence (CL) can be used to detect OPEs, via radical formation consisting of peroxide moieties (-O-O-) under acidic conditions. However, selectivity for specific OPEs is hampered by the ubiquitous background of H2O2. Herein, we report the differentiation of hexamethylene triperoxide diamine (HMTD), triacetone triperoxide (TATP), and methyl ethyl ketone peroxide (MEKP) by specific flow injection analysis-CL (FIA-CL) signal profiles, after H2SO4 treatment. The radical degradation pathway of each structure, and its corresponding FIA-CL profile, was explored using mass spectrometry to reveal the rapid loss of -O-O- from TATP and HMTD structures, while MEKP formed CL signal-sustaining oligomers, as opposed to the immediate attenuation of H2O2. The CL response for OPEs in an aqueous media, measured via the described FIA-CL method, enabled ultra-trace limits of detection down to 0.40 μM for MEKP, 0.43 μM for HMTD, and 0.40 μM for TATP (combined linear range 1-83 μM with 95% confidence limit, n = 12). Expanded uncertainties of measurement (UM) of MEKP = ±0.98, HMTD = ±1.03, and TATP = ±1.1 (UM included probabilities of false positive and false negative as well as standard deviations of % recoveries and limit of detections of OPEs). Direct aqueous sample introduction via FIA-CL thus offers the prospect of rapid and selective screening of OPEs in security-heightened settings (e.g., airports), averting false positives from more ubiquitous H2O2.
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Wang G, Guest B, Treadway M, Rudd D, Sugarman K. 174. Evaluation of FilmArray® Blood Culture Identification and TheraDoc® Utilization at a Veterans Affairs Health Care System. Open Forum Infect Dis 2022. [PMCID: PMC9752433 DOI: 10.1093/ofid/ofac492.252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Background Bacteremia is associated with significant morbidity and mortality, with each hour of delay initiating antibiotics associated with a 7.6% decrease in survival rate. At the Salisbury Veterans Affairs Health Care System (VA HCS), FilmArray® Blood Culture Identification (BCID) is used along with TheraDoc® to assist with selection of antimicrobial regimens as an antimicrobial stewardship practice at the site. The purpose of this study is to evaluate the time to appropriate antibiotic therapy based on positive BCID results. Methods This study is a retrospective, quality assurance project conducted at a 284-bed VA medical center from May 2018 through December 2020 of Veterans with positive BCID results identified on TheraDoc®. The primary endpoint is to identify the mean time for initiation of appropriate antimicrobial therapy defined as at least 80% susceptibility on local antibiogram to the resulting BCID organism for Veterans not on antibiotics or on inappropriate therapy from the time of BCID positivity. Secondary endpoints include comparing time to appropriate therapy with or without Infectious Diseases (ID) and Antimicrobial Stewardship Program (ASP) coverage, time to de-escalation, and contributors to time delays. Results A total of 168 Veterans were included in the study with 138 Veterans (82%) receiving appropriate antibiotic therapy at the time of BCID results and 30 Veterans (18%) on inappropriate or no empiric antibiotics. The mean time to appropriate therapy of the 30 Veterans on inappropriate or no antibiotics at the time of BCID positivity was 13 hours and 54 minutes with provider order entry being the largest factor in time delays. Of these 30 Veterans, BCID positivity occurred in 6 Veterans during business hours with onsite availability to ID and ASP to which the mean time to appropriate therapy was 3 hours and 29 minutes compared to 16 hours and 30 minutes for the 24 Veterans with results outside of business hours. For the 138 Veterans on appropriate therapy, the average time to de-escalation was about 43 hours and 52 minutes. Percentage of ID and/or ASP involvement.
![]() This pie chart shows the percentages of Veterans with ID and/or ASP involvement. Time to de-escalation. This graph demonstrates the time to de-escalation for Veterans on appropriate therapy at the time of BCID positivity. Inappropriate Therapy Group.
![]() This graph compares time to appropriate therapy between results occurring during business hours or outside of business hours for Veterans on no initial antibiotics or inappropriate therapy. Conclusion BCID and TheraDoc® are helpful antimicrobial stewardship tools to assist with reducing time to appropriate therapy when consistently monitored. Additional resources and education may be of benefit to providers covering outside of business hours. Example of BCID Algorithm
![]() Creation of a local BCID algorithm has been started as a result of this study. The goal of this resource is to be a tool for providers to help guide therapeutic decisions when ID and/or ASP are not readily available. Disclosures All Authors: No reported disclosures.
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Affiliation(s)
- Galina Wang
- Clement J. Zablocki VA Medical Center, Milwaukee, Wisconsin
| | - Bailey Guest
- Salisbury VA Health Care System, Salisbury, North Carolina
| | | | - David Rudd
- Salisbury VA Health Care System, Salisbury, North Carolina
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10
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Mehta A, Desai A, Rudd D, Siddiqui G, Nowell CJ, Tong Z, Creek DJ, Tayalia P, Gandhi PS, Voelcker NH. Bio-Mimicking Brain Vasculature to Investigate the Role of Heterogeneous Shear Stress in Regulating Barrier Integrity. Adv Biol (Weinh) 2022; 6:e2200152. [PMID: 35999436 DOI: 10.1002/adbi.202200152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 08/04/2022] [Indexed: 01/28/2023]
Abstract
A continuous, sealed endothelial membrane is essential for the blood-brain barrier (BBB) to protect neurons from toxins present in systemic circulation. Endothelial cells are critical sensors of the capillary environment, where factors like fluid shear stress (FSS) and systemic signaling molecules activate intracellular pathways that either promote or disrupt the BBB. The brain vasculature exhibits complex heterogeneity across the bed, which is challenging to recapitulate in BBB microfluidic models with fixed dimensions and rectangular cross-section microchannels. Here, a Cayley-tree pattern, fabricated using lithography-less, fluid shaping technique in a modified Hele-Shaw cell is used to emulate the brain vasculature in a microfluidic chip. This geometry generates an inherent distribution of heterogeneous FSS, due to smooth variations in branch height and width. hCMEC/D3 endothelial cells cultured in the Cayley-tree designed chip generate a 3D monolayer of brain endothelium with branching hierarchy, enabling the study of the effect of heterogeneous FSS on the brain endothelium. The model is employed to study neuroinflammatory conditions by stimulating the brain endothelium with tumor necrosis factor-α under heterogeneous FSS conditions. The model has immense potential for studies involving drug transport across the BBB, which can be misrepresented in fixed dimension models.
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Affiliation(s)
- Ami Mehta
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia.,Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, 400076, India.,IITB-Monash Research Academy, Mumbai, 400076, India
| | - Anal Desai
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - David Rudd
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Ghizal Siddiqui
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Cameron J Nowell
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia.,Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Ziqiu Tong
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Darren J Creek
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Prakriti Tayalia
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - Prasanna S Gandhi
- Suman Mashruwala Advanced Microengineering Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - Nicolas H Voelcker
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia.,Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton, VIC, 3168, Australia.,Department of Materials Science and Engineering, Monash University, Clayton, VIC, 3800, Australia
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11
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Esfandiary A, Finkelstein DI, Voelcker NH, Rudd D. Clinical Sphingolipids Pathway in Parkinson’s Disease: From GCase to Integrated-Biomarker Discovery. Cells 2022; 11:cells11081353. [PMID: 35456032 PMCID: PMC9028315 DOI: 10.3390/cells11081353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/11/2022] [Accepted: 04/13/2022] [Indexed: 02/01/2023] Open
Abstract
Alterations in the sphingolipid metabolism of Parkinson’s Disease (PD) could be a potential diagnostic feature. Only around 10–15% of PD cases can be diagnosed through genetic alterations, while the remaining population, idiopathic PD (iPD), manifest without validated and specific biomarkers either before or after motor symptoms appear. Therefore, clinical diagnosis is reliant on the skills of the clinician, which can lead to misdiagnosis. IPD cases present with a spectrum of non-specific symptoms (e.g., constipation and loss of the sense of smell) that can occur up to 20 years before motor function loss (prodromal stage) and formal clinical diagnosis. Prodromal alterations in metabolites and proteins from the pathways underlying these symptoms could act as biomarkers if they could be differentiated from the broad values seen in a healthy age-matched control population. Additionally, these shifts in metabolites could be integrated with other emerging biomarkers/diagnostic tests to give a PD-specific signature. Here we provide an up-to-date review of the diagnostic value of the alterations in sphingolipids pathway in PD by focusing on the changes in definitive PD (postmortem confirmed brain data) and their representation in “probable PD” cerebrospinal fluid (CSF) and blood. We conclude that the trend of holistic changes in the sphingolipid pathway in the PD brain seems partly consistent in CSF and blood, and could be one of the most promising pathways in differentiating PD cases from healthy controls, with the potential to improve early-stage iPD diagnosis and distinguish iPD from other Parkinsonism when combined with other pathological markers.
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Affiliation(s)
- Ali Esfandiary
- Drug Delivery, Disposition and Dynamics, Monash University, Parkville, VIC 3052, Australia; (A.E.); (N.H.V.)
- Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton, VIC 3168, Australia
| | | | - Nicolas Hans Voelcker
- Drug Delivery, Disposition and Dynamics, Monash University, Parkville, VIC 3052, Australia; (A.E.); (N.H.V.)
- Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton, VIC 3168, Australia
- Commonwealth Scientific and Industrial Research Organization (CSIRO), Clayton, VIC 3168, Australia
- Materials Science and Engineering, Monash University, Clayton, VIC 3168, Australia
| | - David Rudd
- Drug Delivery, Disposition and Dynamics, Monash University, Parkville, VIC 3052, Australia; (A.E.); (N.H.V.)
- Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton, VIC 3168, Australia
- Correspondence: ; Tel.: +61-3-9903-9581
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12
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Ayurini M, Chandler PG, O’Leary PD, Wang R, Rudd D, Milewska KD, Malins LR, Buckle AM, Hooper JF. Polymer End Group Control through a Decarboxylative Cobalt-Mediated Radical Polymerization: New Avenues for Synthesizing Peptide, Protein, and Nanomaterial Conjugates. JACS Au 2022; 2:169-177. [PMID: 35098233 PMCID: PMC8790747 DOI: 10.1021/jacsau.1c00453] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Indexed: 06/14/2023]
Abstract
Cobalt-mediated radical polymerizations (CMRPs) have been initiated by the radical decarboxylation of tetrachlorophthalimide activated esters. This allows for the controlled radical polymerization of activated monomers across a broad temperature range with a single cobalt species, with the incorporation of polymer end groups derived from simple carboxylic acid derivatives and termination with an organozinc reagent. This method has been applied to the synthesis of a polymer/graphene conjugate and a water-soluble protein/polymer conjugate, demonstrating the first examples of CMRP in graphene and protein conjugation.
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Affiliation(s)
- Meri Ayurini
- Department
of Chemistry, Monash University, Clayton, 3800 Victoria, Australia
- Chemistry
Department, Universitas Pertamina, South Jakarta 12220, Indonesia
| | - Peter G. Chandler
- Department
of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, 3800 Victoria, Australia
| | - Paul D. O’Leary
- Department
of Chemistry, Monash University, Clayton, 3800 Victoria, Australia
| | - Ruoxin Wang
- Department
of Chemical Engineering, Monash University, Clayton, 3800 Victoria, Australia
| | - David Rudd
- Monash
Institute of Pharmaceutical Science, Parkville, 3052 Victoria, Australia
| | - Karen D. Milewska
- Research
School of Chemistry, Australian National
University, Acton, 2601 Australian Capital Territory, Australia
| | - Lara R. Malins
- Research
School of Chemistry, Australian National
University, Acton, 2601 Australian Capital Territory, Australia
| | - Ashley M. Buckle
- Department
of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, 3800 Victoria, Australia
| | - Joel F. Hooper
- Department
of Chemistry, Monash University, Clayton, 3800 Victoria, Australia
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13
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Chen Y, Alba M, Tieu T, Tong Z, Minhas RS, Rudd D, Voelcker NH, Cifuentes-Rius A, Elnathan R. Engineering Micro–Nanomaterials for Biomedical Translation. Adv NanoBio Res 2021. [DOI: 10.1002/anbr.202100002] [Citation(s) in RCA: 6] [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: 12/15/2022] Open
Affiliation(s)
- Yaping Chen
- Monash Institute of Pharmaceutical Sciences Monash University 381 Royal Parade Parkville VIC 3052 Australia
- Melbourne Centre for Nanofabrication Victorian Node of the Australian National Fabrication Facility 151 Wellington Road Clayton VIC 3168 Australia
| | - Maria Alba
- Monash Institute of Pharmaceutical Sciences Monash University 381 Royal Parade Parkville VIC 3052 Australia
- Melbourne Centre for Nanofabrication Victorian Node of the Australian National Fabrication Facility 151 Wellington Road Clayton VIC 3168 Australia
| | - Terence Tieu
- Monash Institute of Pharmaceutical Sciences Monash University 381 Royal Parade Parkville VIC 3052 Australia
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Manufacturing Commonwealth Scientific and Industrial Research Organisation (CSIRO) Clayton VIC 3168 Australia
| | - Ziqiu Tong
- Monash Institute of Pharmaceutical Sciences Monash University 381 Royal Parade Parkville VIC 3052 Australia
| | - Rajpreet Singh Minhas
- Monash Institute of Pharmaceutical Sciences Monash University 381 Royal Parade Parkville VIC 3052 Australia
- Melbourne Centre for Nanofabrication Victorian Node of the Australian National Fabrication Facility 151 Wellington Road Clayton VIC 3168 Australia
| | - David Rudd
- Monash Institute of Pharmaceutical Sciences Monash University 381 Royal Parade Parkville VIC 3052 Australia
- Melbourne Centre for Nanofabrication Victorian Node of the Australian National Fabrication Facility 151 Wellington Road Clayton VIC 3168 Australia
| | - Nicolas H. Voelcker
- Monash Institute of Pharmaceutical Sciences Monash University 381 Royal Parade Parkville VIC 3052 Australia
- Melbourne Centre for Nanofabrication Victorian Node of the Australian National Fabrication Facility 151 Wellington Road Clayton VIC 3168 Australia
- Department of Materials Science and Engineering Monash University 22 Alliance Lane Clayton VIC 3168 Australia
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Manufacturing Commonwealth Scientific and Industrial Research Organisation (CSIRO) Clayton VIC 3168 Australia
- INM-Leibniz Institute for New Materials Campus D2 2 Saarbrücken 66123 Germany
| | - Anna Cifuentes-Rius
- Monash Institute of Pharmaceutical Sciences Monash University 381 Royal Parade Parkville VIC 3052 Australia
| | - Roey Elnathan
- Monash Institute of Pharmaceutical Sciences Monash University 381 Royal Parade Parkville VIC 3052 Australia
- Melbourne Centre for Nanofabrication Victorian Node of the Australian National Fabrication Facility 151 Wellington Road Clayton VIC 3168 Australia
- Department of Materials Science and Engineering Monash University 22 Alliance Lane Clayton VIC 3168 Australia
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14
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Deepagan VG, Leiske MN, Fletcher NL, Rudd D, Tieu T, Kirkwood N, Thurecht KJ, Kempe K, Voelcker NH, Cifuentes-Rius A. Engineering Fluorescent Gold Nanoclusters Using Xanthate-Functionalized Hydrophilic Polymers: Toward Enhanced Monodispersity and Stability. Nano Lett 2021; 21:476-484. [PMID: 33350838 DOI: 10.1021/acs.nanolett.0c03930] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We introduce xanthate-functionalized poly(cyclic imino ethers)s (PCIEs), specifically poly(2-ethyl-2-oxazoline) and poly(2-ethyl-2-oxazine) given their stealth characteristics, as an attractive alternative to conventional thiol-based ligands for the synthesis of highly monodisperse and fluorescent gold nanoclusters (AuNCs). The xanthate in the PCIEs interacts with Au ions, acting as a well-controlled template for the direct formation of PCIE-AuNCs. This method yields red-emitting AuNCs with a narrow emission peak (λem = 645 nm), good quantum yield (4.3-4.8%), long fluorescence decay time (∼722-844 ns), and unprecedented product yield (>98%). The PCIE-AuNCs exhibit long-term colloidal stability, biocompatibility, and antifouling properties, enabling a prolonged blood circulation, lower nonspecific accumulation in major organs, and better renal clearance when compared with AuNCs without polymer coating. The advances made here in the synthesis of metal nanoclusters using xanthate-functionalized PCIEs could propel the production of highly monodisperse, biocompatible, and renally clearable nanoprobes in large-scale for different theranostic applications.
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Affiliation(s)
- Veerasikku Gopal Deepagan
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville Campus, 381 Royal Parade, Parkville Victoria 3052, Australia
| | - Meike N Leiske
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville Campus, 381 Royal Parade, Parkville Victoria 3052, Australia
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Nicholas L Fletcher
- Centre for Advanced Imaging (CAI) and Australian Institute for Bioengineering and Nanotechnology (AIBN), ARC Centre of Excellence in Convergent Bio-Nano Science and Technology and ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - David Rudd
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville Campus, 381 Royal Parade, Parkville Victoria 3052, Australia
| | - Terence Tieu
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville Campus, 381 Royal Parade, Parkville Victoria 3052, Australia
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Manufacturing, Bayview Avenue, Clayton, Victoria 3168, Australia
| | - Nicholas Kirkwood
- ARC Centre of Excellence in Exciton Science, School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Kristofer J Thurecht
- Centre for Advanced Imaging (CAI) and Australian Institute for Bioengineering and Nanotechnology (AIBN), ARC Centre of Excellence in Convergent Bio-Nano Science and Technology and ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Kristian Kempe
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville Campus, 381 Royal Parade, Parkville Victoria 3052, Australia
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria 3168, Australia
| | - Nicolas H Voelcker
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville Campus, 381 Royal Parade, Parkville Victoria 3052, Australia
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) Manufacturing, Bayview Avenue, Clayton, Victoria 3168, Australia
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria 3168, Australia
- Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, 151 Wellington Road, Clayton, Victoria 3168, Australia
| | - Anna Cifuentes-Rius
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville Campus, 381 Royal Parade, Parkville Victoria 3052, Australia
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
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15
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Abstract
Introduction Opiate-induced chest wall rigidity is a syndrome that largely goes unrecognized. To date, no study has presented significant objective data to better understand this syndrome. Objective The aim of this study was to explore the correlation between the dosage of opiates and the incidence of chest wall rigidity, ventilatory changes, and effects of naloxone administration. Methods A total of eight patients were identified as having episodes of chest wall rigidity, with half of the population being females, with an average age of 54.8 ± 9 years. Physiological changes, ventilator data, vitals, and opiate dosage prior to chest wall rigidity episodes and after reversal with naloxone administration were analyzed using the Wilcoxon rank sum test for statistical significance. Results Significant changes were observed in dynamic wall compliance without positive end-expiratory pressure (PEEP) (pre-median=5.13; post-median=52.03; p=0.0078), dynamic wall compliance with PEEP (pre-median=6.13; post-median=72.36; p=0.0078), tidal volume (pre-median=110.5; post-median=1006; p=0.0078), and ventilator airflow (pre-median=0; post-median=75; p=0.0078). However, no statistically significant changes were detected in end tidal CO2 (pre-median=36; post-median=37.5; p=0.4219), respiratory rate (pre-median=9; post-median=10.5; p=0.7188), or peak airway pressure (pre-median=17; post-median=21.5; p=0.4063). Additionally, there is a statistically significant correlation between morphine equivalent potency dosing within 24 hours and the change in tidal volume (r=0.8237; p=0.0439). Conclusions Our study is the first to demonstrate significant objective data on the ventilatory responses seen with opiate-induced chest wall rigidity. These findings may assist clinicians in better understanding the presentation and management of chest wall rigidity.
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Affiliation(s)
| | - David Rudd
- Surgery, Arrowhead Regional Medical Center, Colton, USA
| | - Hakan Ogutcu
- Surgery, Arrowhead Regional Medical Center, Colton, USA
| | - Fanglong Dong
- Emergency Medicine, Arrowhead Regional Medical Center, Colton, USA
| | - David Wong
- Surgery, Arrowhead Regional Medical Center, Colton, USA
| | - Michael Neeki
- Emergency Medicine, Arrowhead Regional Medical Center, Colton, USA
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16
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Ewere EE, Powell D, Rudd D, Reichelt-Brushett A, Mouatt P, Voelcker NH, Benkendorff K. Uptake, depuration and sublethal effects of the neonicotinoid, imidacloprid, exposure in Sydney rock oysters. Chemosphere 2019; 230:1-13. [PMID: 31100675 DOI: 10.1016/j.chemosphere.2019.05.045] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 04/26/2019] [Accepted: 05/05/2019] [Indexed: 06/09/2023]
Abstract
The broad utilisation of imidacloprid (IMI) in agriculture poses an increasing risk to aquatic organisms. However, the potential impacts on commercially important shellfish and chemical residues after exposure, are yet to be assessed. We investigated the levels of IMI in Sydney rock oyster (SRO) tissue during a three-day uptake and four-day depuration cycle using liquid chromatography-mass spectrometry. IMI was absorbed from the water, with significantly higher concentrations in the adductor muscles than the gills and digestive glands. Depuration was also fast with a significant drop in tissue concentrations after one day in clean water and complete elimination from all tissues except the digestive gland after four days. The distribution of IMI in SRO after direct exposure using mass spectrometry imaging demonstrated uptake and spatially resolved metabolism to hydroxyl-IMI in the digestive gland and IMI-olefin in the gills. We assessed the effects of IMI on filtration rate (FR), acetylcholinesterase (AChE) activity in the gills, and gene expression profiles in the digestive gland using transcriptomics. Exposure to 2 mg/L IMI reduced the FR of oysters on the first day, while exposure to 0.5 and 1 mg/L reduced FR on day four. IMI reduced the gill AChE activity and altered the digestive gland gene expression profile. This study indicates that commercially farmed SRO can uptake IMI from the water, but negative impacts were only detected at concentrations higher than currently detected in estuarine environments and the chemical residues can be effectively eliminated using simple depuration in clean water.
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Affiliation(s)
- Endurance E Ewere
- Marine Ecology Research Centre, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia
| | - Daniel Powell
- Centre for Genetics, Ecology and Physiology, University of the Sunshine Coast, Maroochydore DC, QLD, 4558, Australia; Department of Biology, Lund University, Sölvegatan 37, 223 62, Lund, Sweden
| | - David Rudd
- Drug Delivery Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia; Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton, Victoria, 3168, Australia
| | - Amanda Reichelt-Brushett
- Marine Ecology Research Centre, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia
| | - Peter Mouatt
- Southern Cross Plant Science, Southern Cross University, PO Box 157, Lismore, NSW, 2480 Australia
| | - Nicolas H Voelcker
- Drug Delivery Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia; Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton, Victoria, 3168, Australia
| | - Kirsten Benkendorff
- Marine Ecology Research Centre, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia.
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17
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Abstract
BACKGROUND Serum creatinine (SCr) measurement to determine glomerular filtration rate (GFR) in neonates has many pitfalls. Cystatin C (CysC) appears to be a more reliable biomarker. METHODS We investigated the effect of birth weight on SCr and CysC measurements in a cohort of 74 infants, consisting of both term and ex-premature infants at term postmenstrual age. SCr and Cys C measurements were carried out at the same time. RESULTS Eighty six infants were recruited into this study out of which complete data were available in 80 infants. The cohort consists of both term and premature infants at term PMA (31 terms and 49 preterms). The median SCr level was 17 [12-26] umol/L and mean CysC level was 1.64 [0.27] mg/L. SCr had a significant correlation with weight (r = 0.3; P = 0.011), whereas serum CysC had no correlation with the infant's weight (r = 0.01; P = 0.95). There were no statistically significant difference in SCr and CysC between male and female infants. CONCLUSION Unlike CysC, SCr had a significant correlation with birth weight. SCr based GFR measurement may cause a delay in diagnosis of acute kidney injury in smaller neonates.
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Affiliation(s)
- Y Kandasamy
- Department of Neonatology, The Townsville Hospital, QLD, Australia.,Mothers and Babies Research Centre, Hunter Medical Research Institute, John Hunter Hospital, The University of Newcastle, NSW, Australia.,College of Public Health, Medical and Veterinary Sciences, The James Cook University, QLD, Australia
| | - D Rudd
- College of Public Health, Medical and Veterinary Sciences, The James Cook University, QLD, Australia
| | - R Smith
- Mothers and Babies Research Centre, Hunter Medical Research Institute, John Hunter Hospital, The University of Newcastle, NSW, Australia
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18
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Nongmaithem BD, Mouatt P, Smith J, Rudd D, Russell M, Sullivan C, Benkendorff K. Volatile and bioactive compounds in opercula from Muricidae molluscs supports their use in ceremonial incense and traditional medicines. Sci Rep 2017; 7:17404. [PMID: 29234065 PMCID: PMC5727037 DOI: 10.1038/s41598-017-17551-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 11/28/2017] [Indexed: 01/02/2023] Open
Abstract
Muricidae molluscs are the source of a valuable purple dye that was traded as a luxury item in the Mediterranean region and by the late Byzantine was reserved for royalty and priests. Less well known is the use of muricid opercula in sacred incense and traditional medicines, although they are still used as rare ingredients today. This study provides the first chemical assessment of opercula from Muricidae, based on several traditional preparation procedures. Chemical analysis of opercula smoke revealed aromatic phenols, which act as fragrance stabilisers and produce a "medicinal" odour. Analysis of lipid extracts revealed pharmaceutically active compounds, including brominated indoles, choline esters and adenosine, consistent with their traditional medical applications. Depending on the preparation procedures, toxic pyridine was also detected. ICP-MS analysis of muricid opercula shows the presence of essential macro and microelements, as well as metals, some of which exceed the recommended safe levels for human use. Nevertheless, these findings support the Muricidae as an historically important marine resource, providing Biblical dyes, medicines and perfume. The opercula contains biologically active compounds and produces smoke containing volatile scent compounds, consistent with their identification as the most likely source of onycha, a controversial ingredient in sacred incense.
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Affiliation(s)
- Bijayalakshmi Devi Nongmaithem
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia
| | - Peter Mouatt
- Southern Cross Plant Science, Southern Cross University, Lismore, NSW-2480, Australia
| | - Joshua Smith
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia.,Southern Cross Plant Science, Southern Cross University, Lismore, NSW-2480, Australia
| | - David Rudd
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia
| | - Michael Russell
- Southern Cross Plant Science, Southern Cross University, Lismore, NSW-2480, Australia
| | - Caroline Sullivan
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia
| | - Kirsten Benkendorff
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia.
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Ahmad TB, Rudd D, Benkendorff K, Mahdi LK, Pratt KA, Dooley L, Wei C, Kotiw M. Brominated indoles from a marine mollusc inhibit inflammation in a murine model of acute lung injury. PLoS One 2017; 12:e0186904. [PMID: 29073178 PMCID: PMC5658094 DOI: 10.1371/journal.pone.0186904] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Accepted: 09/24/2017] [Indexed: 12/03/2022] Open
Abstract
New drug leads for the treatment of inflammation are urgently needed. Marine molluscs are widely used as traditional medicines for the treatment of inflammation. Here we report the positive effects of a hypobranchial gland (HBG) extract and the dominant bioactive compound 6-bromoisatin from the Muricidae mollusc Dicathais orbita, for reducing lipopolysaccharide (LPS) induced acute lung inflammation in a mouse model. Both 6-bromoisatin and the HBG extract suppressed the inflammatory response in mice that were pre-treated by oral gavage at 48, 24 and 1 h prior to LPS infusion. The inflammatory antagonists were tested at concentrations of 0.5 mg/g and 0.1 mg/g HBG extract and 0.1 mg/g and 0.05 mg/g 6-bromoisatin in carrier oil and all treatments reduced inflammation as indicated by a significant suppression of inflammatory markers present in bronchoalveolar lavage fluid (BALF), in comparison to LPS induced positive control mice administered the carrier oil alone (p < 0.0001). Tumour necrosis factor-alpha (TNFα) and interleukin-1 beta (IL-1β) levels, in addition to total protein concentration were all significantly reduced in BALF from mice treated with the extract or 6-bromoisatin. Furthermore, all treatment groups showed significant reductions in neutrophil sequestration and preservation of the lung tissue architecture compared to the positive control (p < 0.0001). The combined results from this study and our previous in vitro studies indicate that 6-bromoisatin in the HGB extracts inhibit the activation of inflammatory signalling pathway. The results from this study further confirm that the HBG extract from Muricidae molluscs and 6-bromoisatin are bioavailable and effective in vivo, thus have potential for development as natural therapeutic agents for inflammation.
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Affiliation(s)
- Tarek B. Ahmad
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, Australia
- Centre for Health Sciences Research, University of Southern Queensland, Toowoomba, QLD, Australia
| | - David Rudd
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, Australia
| | - Kirsten Benkendorff
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, Australia
- * E-mail:
| | - Layla K. Mahdi
- Centre for Health Sciences Research, University of Southern Queensland, Toowoomba, QLD, Australia
| | - Kaylah-Ann Pratt
- Centre for Health Sciences Research, University of Southern Queensland, Toowoomba, QLD, Australia
| | - Leanne Dooley
- Centre for Health Sciences Research, University of Southern Queensland, Toowoomba, QLD, Australia
| | - Chuanyu Wei
- Centre for Health Sciences Research, University of Southern Queensland, Toowoomba, QLD, Australia
| | - Michael Kotiw
- Centre for Health Sciences Research, University of Southern Queensland, Toowoomba, QLD, Australia
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20
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Gustafsson OJR, Guinan TM, Rudd D, Kobus H, Benkendorff K, Voelcker NH. Metabolite mapping by consecutive nanostructure and silver-assisted mass spectrometry imaging on tissue sections. Rapid Commun Mass Spectrom 2017; 31:991-1000. [PMID: 28370605 DOI: 10.1002/rcm.7869] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 03/11/2017] [Accepted: 03/28/2017] [Indexed: 06/07/2023]
Abstract
RATIONALE Nanostructure-based mass spectrometry imaging (MSI) is a promising technology for molecular imaging of small molecules, without the complex chemical background typically encountered in matrix-assisted molecular imaging approaches. Here, we have enhanced these surfaces with silver (Ag) to provide a second tier of MSI data from a single sample. METHODS MSI data was acquired through the application of laser desorption/ionization mass spectrometry to biological samples imprinted onto desorption/ionization on silicon (DIOS) substrates. Following initial analysis, ultra-thin Ag layers were overlaid onto the followed by MSI analysis (Ag-DIOS MSI). This approach was first demonstrated for fingermark small molecules including environmental contaminants and sebum components. Subsequently, this bimodal method was translated to lipids and metabolites in fore-stomach sections from a 6-bromoisatin chemopreventative murine mouse model. RESULTS DIOS MSI allowed mapping of common ions in fingermarks as well as 6-bromoisatin metabolites and lipids in murine fore-stomach. Furthermore, DIOS MSI was complemented by the Ag-DIOS MSI of Ag-adductable lipids such as wax esters in fingermarks and cholesterol in murine fore-stomach. Gastrointestinal acid condensation products of 6-bromoisatin, such as the 6,6'-dibromoindirubin mapped herein, are very challenging to isolate and characterize. By re-analyzing the same tissue imprints, this metabolite was readily detected by DIOS, placed in a tissue-specific spatial context, and subsequently overlaid with additional lipid distributions acquired using Ag-DIOS MSI. CONCLUSIONS The ability to place metabolite and lipid classes in a tissue-specific context makes this novel method suited to MSI analyses where the collection of additional information from the same sample maximises resource use, and also maximises the number of annotated small molecules, in particular for metabolites that are typically undetectable with traditional platforms. Copyright © 2017 John Wiley & Sons, Ltd.
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Affiliation(s)
- O J R Gustafsson
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, Australia, 5095
| | - T M Guinan
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, Australia, 5095
| | - D Rudd
- School of Environment, Science and Engineering, Southern Cross University, Lismore, New South Wales, Australia, 2480
| | - H Kobus
- School of Chemical and Physical Sciences, Flinders University, Bedford Park, South Australia, Australia, 5042
| | - K Benkendorff
- School of Environment, Science and Engineering, Southern Cross University, Lismore, New South Wales, Australia, 2480
| | - N H Voelcker
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, Australia, 5095
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21
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Rudd D, Bajillan H, Comarmond CD. Effects on Liver Stiffness Following Treatment of Hepatitis C With Direct-Acting Antivirals as Evaluated by Vibration Controlled Transient Elastography. Open Forum Infect Dis 2016. [DOI: 10.1093/ofid/ofw172.309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- David Rudd
- Infectious Diseases, Wake Forest Baptist Medical Center, Winston-Salem, North Carolina
| | - Hendren Bajillan
- Infectious Diseases, W. G. (Bill) Hefner VA Medical Center, Salisbury, North Carolina
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Macfarlane AI, Rudd D, Knight E, Marshman LAG, Guazzo EP, Anderson DS. Prospective controlled cohort study of Troponin I levels in patients undergoing elective spine surgery for degenerative conditions: Prone versus supine position. J Clin Neurosci 2016; 35:62-66. [PMID: 27707615 DOI: 10.1016/j.jocn.2016.09.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Accepted: 09/15/2016] [Indexed: 11/17/2022]
Abstract
Prior studies have suggested that elevated serum Troponin-I (TnI) levels immediately after non-cardiac surgical procedures (8-40%) represent subclinical cardiac stress which independently predicts increased 30-day mortality. Routine post-operative TnI monitoring has therefore been suggested as a standard of care. However, no prior studies have focussed on elective degenerative spine surgery, whilst few have measured pre-op TnI. Further, prolonged prone positioning could represent an additional, independent, cardiac stress. We planned a prospective controlled cohort study of consecutive TnI levels in routine elective spine surgery for degenerative spine conditions, incorporating 3 groups: 'prone<2h', 'prone>2h' and 'supine' positioning. TnI levels (>0.04μg/L) were recorded immediately pre-/post-surgery, and by 24h of surgery. N=120 patients were recruited. Complete results were obtained in 92 (39 supine, 53 prone). No significant between-groups differences were observed in demographic or cardiovascular risk factors. Validated TnI-elevation by 24h was not observed in any group. Spurious elevations were recorded in one 'prone<2h' and one 'prone>2h'. One non-ST segment myocardial infarction (STEMI) occurred on day 7 without TnI elevation by 24h (prone>2h). There was no 30-day mortality. CONCLUSIONS Despite a lower cut-off, no validated TnI elevation was observed in any group by 24h after surgery. One non-STEMI had not been associated with TnI-elevation by 24h. Immediately peri-operative cardiac stress therefore appeared comparatively rare in patients undergoing routine elective spine surgery. Further, prone positioning did not represent an additional, independent, risk. Routine immediately post-operative TnI monitoring in elective spine surgery therefore appears unjustified. Our study highlighted several caveats regarding consecutive TnI testing.
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Affiliation(s)
- A I Macfarlane
- Department of Neurosurgery, The Townsville Hospital, Douglas, Townsville 4810, Queensland, Australia
| | - D Rudd
- College of Public Health, Medical and Veterinary Sciences James Cook University, Douglas, Townsville 4810, Queensland, Australia
| | - E Knight
- Department of Neurosurgery, The Townsville Hospital, Douglas, Townsville 4810, Queensland, Australia
| | - L A G Marshman
- Department of Neurosurgery, The Townsville Hospital, Douglas, Townsville 4810, Queensland, Australia; School of Medicine and Dentistry, James Cook University, Douglas, Townsville 4810, Queensland, Australia.
| | - E P Guazzo
- Department of Neurosurgery, The Townsville Hospital, Douglas, Townsville 4810, Queensland, Australia; School of Medicine and Dentistry, James Cook University, Douglas, Townsville 4810, Queensland, Australia
| | - D S Anderson
- Department of Neurosurgery, The Townsville Hospital, Douglas, Townsville 4810, Queensland, Australia
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23
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Affiliation(s)
- David Rudd
- 58 Rwersdale Road, Hull, North Humberside, HU6 7HA, United Kingdom
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24
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Affiliation(s)
- David Rudd
- The Ryley Library Bolton Institute of Higher Education Chadwick Street Bolton BL2 IJW, U.K
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25
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Rudd D, Ronci M, Johnston MR, Guinan T, Voelcker NH, Benkendorff K. Mass spectrometry imaging reveals new biological roles for choline esters and Tyrian purple precursors in muricid molluscs. Sci Rep 2015; 5:13408. [PMID: 26324173 PMCID: PMC4555103 DOI: 10.1038/srep13408] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 07/27/2015] [Indexed: 12/29/2022] Open
Abstract
Despite significant advances in chemical ecology, the biodistribution, temporal changes and ecological function of most marine secondary metabolites remain unknown. One such example is the association between choline esters and Tyrian purple precursors in muricid molluscs. Mass spectrometry imaging (MSI) on nano-structured surfaces has emerged as a sophisticated platform for spatial analysis of low molecular mass metabolites in heterogeneous tissues, ideal for low abundant secondary metabolites. Here we applied desorption-ionisation on porous silicon (DIOS) to examine in situ changes in biodistribution over the reproductive cycle. DIOS-MSI showed muscle-relaxing choline ester murexine to co-localise with tyrindoxyl sulfate in the biosynthetic hypobranchial glands. But during egg-laying, murexine was transferred to the capsule gland, and then to the egg capsules, where chemical ripening resulted in Tyrian purple formation. Murexine was found to tranquilise the larvae and may relax the reproductive tract. This study shows that DIOS-MSI is a powerful tool that can provide new insights into marine chemo-ecology.
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Affiliation(s)
- David Rudd
- School of Biological Sciences, Flinders University, Bedford Park, SA 5042, Australia
| | - Maurizio Ronci
- Mawson Institute, University of South Australia, Mawson Lakes, SA 5095, Australia.,Department of Medical, Oral and Biotechnological Sciences, University G. D'Annunzio, Chieti-Pescara, Italy
| | - Martin R Johnston
- Flinders Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Bedford Park, SA 5042, Australia
| | - Taryn Guinan
- Mawson Institute, University of South Australia, Mawson Lakes, SA 5095, Australia
| | - Nicolas H Voelcker
- Mawson Institute, University of South Australia, Mawson Lakes, SA 5095, Australia
| | - Kirsten Benkendorff
- Marine Ecology Research Centre, Southern Cross University, P.O. Box 157, Lismore, NSW 2480, Australia
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Rudd D, Benkendorff K, Voelcker NH. Solvent separating secondary metabolites directly from biosynthetic tissue for surface-assisted laser desorption ionisation mass spectrometry. Mar Drugs 2015; 13:1410-31. [PMID: 25786067 PMCID: PMC4377991 DOI: 10.3390/md13031410] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [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: 11/30/2014] [Revised: 02/13/2015] [Accepted: 03/02/2015] [Indexed: 11/16/2022] Open
Abstract
Marine bioactive metabolites are often heterogeneously expressed in tissues both spatially and over time. Therefore, traditional solvent extraction methods benefit from an understanding of the in situ sites of biosynthesis and storage to deal with heterogeneity and maximize yield. Recently, surface-assisted mass spectrometry (MS) methods namely nanostructure-assisted laser desorption ionisation (NALDI) and desorption ionisation on porous silicon (DIOS) surfaces have been developed to enable the direct detection of low molecular weight metabolites. Since direct tissue NALDI-MS or DIOS-MS produce complex spectra due to the wide variety of other metabolites and fragments present in the low mass range, we report here the use of "on surface" solvent separation directly from mollusc tissue onto nanostructured surfaces for MS analysis, as a mechanism for simplifying data annotation and detecting possible artefacts from compound delocalization during the preparative steps. Water, ethanol, chloroform and hexane selectively extracted a range of choline esters, brominated indoles and lipids from Dicathais orbita hypobranchial tissue imprints. These compounds could be quantified on the nanostructured surfaces by comparison to standard curves generated from the pure compounds. Surface-assisted MS could have broad utility for detecting a broad range of secondary metabolites in complex marine tissue samples.
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Affiliation(s)
- David Rudd
- Biological Sciences, Faculty of Science and Engineering, Flinders University of South Australia, PO Box 2100, Adelaide, SA 5001, Australia.
| | - Kirsten Benkendorff
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, PO Box 157, Lismore, NSW 2480, Australia.
| | - Nicolas H Voelcker
- Australian Research Council Centre of Excellence in Convergent Bio-Nano Science and Technology, Mawson Institute, University of South Australia, GPO Box 2471, Adelaide, South Australia 5001, Australia.
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Ronci M, Rudd D, Guinan T, Benkendorff K, Voelcker NH. Mass spectrometry imaging on porous silicon: investigating the distribution of bioactives in marine mollusc tissues. Anal Chem 2012; 84:8996-9001. [PMID: 23009618 DOI: 10.1021/ac3027433] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Desorption/ionization on porous silicon-mass spectrometry (DIOS-MS) is an attractive alternative to conventional matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for the analysis of low molecular weight compounds. Porous silicon (pSi) chips are also suitable as support for mass spectrometry imaging (MSI). Here, we report an implementation of DIOS-MSI using the biosynthetic organs of a marine mollusc for proof of principle. The tissue section is stamped onto a fluorocarbon-functionalized pSi chip, which extracts and traps small hydrophobic molecules from the tissue under retention of their relative spatial distribution. The section is subsequently removed and the chip is imaged without any remaining tissue. We apply this novel tissue contact printing approach to investigate the distribution of biologically active brominated precursors to Tyrian purple in the hypobranchial gland of the marine mollusc, Dicathais orbita, using DIOS-MSI. The tissue contact printing is also compatible with other types of desorption/ionization surfaces, such as nanoassisted laser desorption/ionization (NALDI) targets.
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Affiliation(s)
- Maurizio Ronci
- Mawson Institute, University of South Australia, Mawson Lakes, SA 5095, Australia.
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Abstract
We present the use of optical fibers to form a counter-propagating optical trap as a means of manipulating both solid and liquid aerosols. We explore the use of single and multimode fibers to achieve trapping of various particles in air, present the trapping properties of the different fiber types and compare the observed trends to those predicted by theory. Using fibers, we are able to hold suspended particles for extended periods of time and to precisely manipulate them over distances of several hundred microns. We discuss the difficulties and advantages of each fiber configuration and conclude with a demonstration that fiber based trapping offers a good candidate for studying optical binding in air.
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Affiliation(s)
- D Rudd
- Electronic Engineering and Physics Division, University of Dundee, Dundee, UK
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Abstract
This study investigated the effects of cold water immersion on recovery from anaerobic cycling. Seventeen (13 male, 4 female) active subjects underwent a crossover, randomised design involving two testing sessions 2 - 6 d apart. Testing involved two 30-s maximal cycling efforts separated by a one-hour recovery period of 10-min cycling warm-down followed by either passive rest or 15-min cold water immersion (13 - 14 degrees C) with passive rest. Peak power, total work and postexercise blood lactate were significantly reduced following cold water immersion compared to the first exercise test and the control condition. These variables did not differ significantly between the control tests. Peak exercise heart rate was significantly lower after cold water immersion compared to the control. Time to peak power, rating of perceived exertion, and blood pH were not affected by cold water immersion compared to the control. Core temperature rose significantly (0.3 degrees C) during ice bath immersion but a similar increase also occurred in the control condition. Therefore, cold water immersion caused a significant decrease in sprint cycling performance with one-hour recovery between tests.
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Affiliation(s)
- M J Crowe
- Institute of Sport and Exercise Science, James Cook University, Townsville, Australia.
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Crowe M, O'Connor D, Rudd D. 397 Effects of ice bath immersion on recovery from anaerobic exercise. J Sci Med Sport 2005. [DOI: 10.1016/s1440-2440(17)30894-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Pichot T, Rudd D. Preventative mental health in disaster situations: "terror on the autobahn". Mil Med 1991; 156:540-3. [PMID: 1749499] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
As part of Return of Forces to Germany 1990, a number of Second Armored Division soldiers participated in the heroic rescue of German and American civilians injured in a 32-vehicle crash on an autobahn in West Germany. Six people were killed and 18 others were seriously injured at the accident site. This paper (1) briefly reviews acute and chronic stress reactions; (2) describes the accident and rescue; (3) emphasizes specific risk factors for the rescuers; and (4) reviews specific preventative actions that were taken to minimize the risk of future psychologic morbidity in these individuals.
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Affiliation(s)
- T Pichot
- Second Armored Division, Texas A&M University, College of Medicine, Fort Hood 76544-5063
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Abstract
Auditory evoked potentials obtained on infants and children recovering from bacterial meningitis are effective in early and reliable detection of sensorineural deafness, particularly in those who demonstrate absence of wave I.
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