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Tran LT, Akıl C, Senju Y, Robinson RC. The eukaryotic-like characteristics of small GTPase, roadblock and TRAPPC3 proteins from Asgard archaea. Commun Biol 2024; 7:273. [PMID: 38472392 DOI: 10.1038/s42003-024-05888-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 02/06/2024] [Indexed: 03/14/2024] Open
Abstract
Membrane-enclosed organelles are defining features of eukaryotes in distinguishing these organisms from prokaryotes. Specification of distinct membranes is critical to assemble and maintain discrete compartments. Small GTPases and their regulators are the signaling molecules that drive membrane-modifying machineries to the desired location. These signaling molecules include Rab and Rag GTPases, roadblock and longin domain proteins, and TRAPPC3-like proteins. Here, we take a structural approach to assess the relatedness of these eukaryotic-like proteins in Asgard archaea, the closest known prokaryotic relatives to eukaryotes. We find that the Asgard archaea GTPase core domains closely resemble eukaryotic Rabs and Rags. Asgard archaea roadblock, longin and TRAPPC3 domain-containing proteins form dimers similar to those found in the eukaryotic TRAPP and Ragulator complexes. We conclude that the emergence of these protein architectures predated eukaryogenesis, however further adaptations occurred in proto-eukaryotes to allow these proteins to regulate distinct internal membranes.
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Affiliation(s)
- Linh T Tran
- Research Institute for Interdisciplinary Science, Okayama University, Okayama, 700-8530, Japan
| | - Caner Akıl
- Research Institute for Interdisciplinary Science, Okayama University, Okayama, 700-8530, Japan
- Division of Structural Biology, University of Oxford, Oxford, England
| | - Yosuke Senju
- Research Institute for Interdisciplinary Science, Okayama University, Okayama, 700-8530, Japan
| | - Robert C Robinson
- Research Institute for Interdisciplinary Science, Okayama University, Okayama, 700-8530, Japan.
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, 21210, Thailand.
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Pan VA, Tran LT, Madden T, Clasie B, Kooy H, Rosenfeld AB, Depauw N. LET d Optimization Verification With an SOI Microdosimeter. Int J Radiat Oncol Biol Phys 2024:S0360-3016(23)08310-4. [PMID: 38300188 DOI: 10.1016/j.ijrobp.2023.12.036] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 11/30/2023] [Accepted: 12/23/2023] [Indexed: 02/02/2024]
Abstract
PURPOSE A first of its kind experimental verification of dose-averaged linear energy transfer (LETd) optimized treatment plans for proton therapy has been carried out using a silicon-on-insulator microdosimeter at the Massachusetts General Hospital (MGH), Boston, USA. METHODS AND MATERIALS Three clinical treatment plans of a typical ependymoma structure set were designed using the standard clinical approach, the proposed protocol approach, and a one-field approach. The plans were then reoptimized to reduce the LETd-weighted dose in the brain stem. All six plans were delivered in a solid water phantom and the experimental yD‾ measured. RESULTS After LETd optimization, a reduction in yD‾ was found within the brain stem by an average of 12%, 19%, and 4% for the clinical, protocol, and one-field plans, respectively, while maintaining adequate coverage of the tumor structure. The experimental LETd-weighted doses were in agreement with the treatment planning system calculations and Monte Carlo simulations and reinforced the improvement of the optimization. CONCLUSIONS This work demonstrates the first experimental verification of the clinical implementation of LETd optimization for patient treatment with proton therapy.
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Affiliation(s)
- V A Pan
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, NSW, Australia.
| | - L T Tran
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - T Madden
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - B Clasie
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - H Kooy
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - A B Rosenfeld
- Centre for Medical and Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - N Depauw
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
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Jakubowski K, Chacon A, Tran LT, Stopic A, Garbe U, Bevitt J, Olsen S, Franklin DR, Rosenfeld A, Guatelli S, Safavi-Naeini M. A Monte Carlo model of the Dingo thermal neutron imaging beamline. Sci Rep 2023; 13:17415. [PMID: 37833371 PMCID: PMC10575880 DOI: 10.1038/s41598-023-44035-4] [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: 04/24/2023] [Accepted: 10/03/2023] [Indexed: 10/15/2023] Open
Abstract
In this study, we present a validated Geant4 Monte Carlo simulation model of the Dingo thermal neutron imaging beamline at the Australian Centre for Neutron Scattering. The model, constructed using CAD drawings of the entire beam transport path and shielding structures, is designed to precisely predict the in-beam neutron field at the position at the sample irradiation stage. The model's performance was assessed by comparing simulation results to various experimental measurements, including planar thermal neutron distribution obtained in-beam using gold foil activation and [Formula: see text]B[Formula: see text]C-coated microdosimeters and the out-of-beam neutron spectra measured with Bonner spheres. The simulation results demonstrated that the predicted neutron fluence at the field's centre is within 8.1% and 2.1% of the gold foil and [Formula: see text]B[Formula: see text]C-coated microdosimeter measurements, respectively. The logarithms of the ratios of average simulated to experimental fluences in the thermal (E[Formula: see text] 0.414 eV), epithermal (0.414 eV < E[Formula: see text] 11.7 keV) and fast (E[Formula: see text] 11.7 keV) spectral regions were approximately - 0.03 to + 0.1, - 0.2 to + 0.15, and - 0.4 to + 0.2, respectively. Furthermore, the predicted thermal, epithermal and fast neutron components in-beam at the sample stage position constituted approximately 18%, 64% and 18% of the total neutron fluence.
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Affiliation(s)
- Klaudiusz Jakubowski
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia
- Australian Nuclear Science and Technology Organisation, Sydney, NSW 2234, Australia
| | - Andrew Chacon
- Australian Nuclear Science and Technology Organisation, Sydney, NSW 2234, Australia
| | - Linh T Tran
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Attila Stopic
- Australian Nuclear Science and Technology Organisation, Sydney, NSW 2234, Australia
| | - Ulf Garbe
- Australian Nuclear Science and Technology Organisation, Sydney, NSW 2234, Australia
| | - Joseph Bevitt
- Australian Nuclear Science and Technology Organisation, Sydney, NSW 2234, Australia
| | - Scott Olsen
- Australian Nuclear Science and Technology Organisation, Sydney, NSW 2234, Australia
| | - Daniel R Franklin
- School of Electrical and Data Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Anatoly Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Susanna Guatelli
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Mitra Safavi-Naeini
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia.
- Australian Nuclear Science and Technology Organisation, Sydney, NSW 2234, Australia.
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Ericson MD, Tran LT, Mathre SS, Freeman KT, Holdaway K, John K, Lunzer MM, Bouchard JL, Haskell-Luevano C. Discovery of a Pan-Melanocortin Receptor Antagonist [Ac-DPhe(pI)-Arg-Nal(2')-Orn-NH 2] at the MC1R, MC3R, MC4R, and MC5R that Mediates an Increased Feeding Response in Mice and a 40-Fold Selective MC1R Antagonist [Ac-DPhe(pI)-DArg-Nal(2')-Arg-NH 2]. J Med Chem 2023; 66:8103-8117. [PMID: 37307241 PMCID: PMC10631449 DOI: 10.1021/acs.jmedchem.3c00432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Discovery of pan-antagonist ligands for the melanocortin receptors will help identify the physiological activities controlled by these receptors. The previously reported MC3R/MC4R antagonist Ac-DPhe(pI)-Arg-Nal(2')-Arg-NH2 was identified herein, for the first time, to possess MC1R and MC5R antagonist activity. Further structure-activity relationship studies probing the second and fourth positions were performed toward the goal of identifying potent melanocortin antagonists. Of the 21 tetrapeptides synthesized, 13 possessed MC1R, MC3R, MC4R, and MC5R antagonist activity. Three tetrapeptides were more than 10-fold selective for the mMC1R, including 8 (LTT1-44, Ac-DPhe(pI)-DArg-Nal(2')-Arg-NH2) that possessed 80 nM mMC1R antagonist potency and was at least 40-fold selective over the mMC3R, mMC4R, and mMC5R. Nine tetrapeptides were selective for the mMC4R, including 14 [SSM1-8, Ac-DPhe(pI)-Arg-Nal(2')-Orn-NH2] with an mMC4R antagonist potency of 1.6 nM. This compound was administered IT into mice, resulting in a dose-dependent increase in the food intake and demonstrating the in vivo utility of this compound series.
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Affiliation(s)
- Mark D Ericson
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Linh T Tran
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Sarah S Mathre
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Katie T Freeman
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Kelsey Holdaway
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Kristen John
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Mary M Lunzer
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Jacob L Bouchard
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Carrie Haskell-Luevano
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, United States
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Hulverson MA, Michaels SA, Lee JW, Wendt KL, Tran LT, Choi R, Van Voorhis WC, Cichewicz RH, Ojo KK. Identification of Fungus-Derived Natural Products as New Antigiardial Scaffolds. Microbiol Spectr 2023; 11:e0064723. [PMID: 37039683 PMCID: PMC10269678 DOI: 10.1128/spectrum.00647-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Accepted: 03/22/2023] [Indexed: 04/12/2023] Open
Abstract
There is an unmet need for effective therapies for treating diseases associated with the intestinal parasite Giardia lamblia. In this study, a library of chemically validated purified natural products and fungal extracts was screened for chemical scaffolds that can inhibit the growth of G. lamblia. The phenotypic screen led to the identification of several previously unreported classes of natural product inhibitors that block the growth of G. lamblia. Hits from phenotypic screens of these naturally derived compounds are likely to possess a variety of mechanisms of action not associated with clinically used nitroimidazole and thiazolide compounds. They may therefore be effective against current drug-resistant parasite strains. IMPORTANCE There is a direct link between widespread prevalence of clinical giardiasis and poverty. This may be one of the reasons why giardiasis is a significant contributor to diarrheal morbidity, stunting, and death of children in resource-limited communities around the world. FDA-approved treatments for giardiasis include metronidazole, related nitroimidazole drugs, and albendazole. However, a substantial number of clinical infections are resistant to these treatments. The depth of the challenge is partly exacerbated by a lack of investment in the discovery and development of novel agents for treatment of giardiasis. Applicable interventions must include new drug development strategies that will result in the identification of effective therapeutics, particularly those that are inexpensive and can be quickly advanced to clinical uses, such as products from nature. This study identified novel chemical scaffolds from fungi that can form the basis of future medicinal chemistry optimization of novel antigiardial agents.
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Affiliation(s)
- Matthew A. Hulverson
- Department of Medicine, Division of Allergy and Infectious Diseases, Center for Emerging and Reemerging Infectious Diseases (CERID), University of Washington, Seattle, Washington, USA
| | - Samantha A. Michaels
- Department of Medicine, Division of Allergy and Infectious Diseases, Center for Emerging and Reemerging Infectious Diseases (CERID), University of Washington, Seattle, Washington, USA
| | - Jin Woo Lee
- College of Pharmacy, Duksung Women’s University, Seoul, Republic of Korea
| | - Karen L. Wendt
- Natural Products Discovery Group, Institute for Natural Products Applications and Research Technologies, Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma, USA
| | - Linh T. Tran
- Department of Medicine, Division of Allergy and Infectious Diseases, Center for Emerging and Reemerging Infectious Diseases (CERID), University of Washington, Seattle, Washington, USA
| | - Ryan Choi
- Department of Medicine, Division of Allergy and Infectious Diseases, Center for Emerging and Reemerging Infectious Diseases (CERID), University of Washington, Seattle, Washington, USA
| | - Wesley C. Van Voorhis
- Department of Medicine, Division of Allergy and Infectious Diseases, Center for Emerging and Reemerging Infectious Diseases (CERID), University of Washington, Seattle, Washington, USA
| | - Robert H. Cichewicz
- Natural Products Discovery Group, Institute for Natural Products Applications and Research Technologies, Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma, USA
| | - Kayode K. Ojo
- Department of Medicine, Division of Allergy and Infectious Diseases, Center for Emerging and Reemerging Infectious Diseases (CERID), University of Washington, Seattle, Washington, USA
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Meouchi C, Barna S, Puchalska M, Tran LT, Rosenfeld A, Verona C, Verona‐Rinati G, Palmans H, Magrin G. On the measurement uncertainty of microdosimetric quantities using diamond and silicon microdosimeters in carbon-ion beams. Med Phys 2022; 49:6699-6715. [PMID: 36039392 PMCID: PMC9826416 DOI: 10.1002/mp.15929] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/13/2022] [Accepted: 08/03/2022] [Indexed: 01/11/2023] Open
Abstract
PURPOSE The purpose of this paper is to compare the response of two different types of solid-state microdosimeters, that is, silicon and diamond, and their uncertainties. A study of the conversion of silicon microdosimetric spectra to the diamond equivalent for microdosimeters with different geometry of the sensitive volumes is performed, including the use of different stopping power databases. METHOD Diamond and silicon microdosimeters were irradiated under the same conditions, aligned at the same depth in a carbon-ion beam at the MedAustron ion therapy center. In order to estimate the microdosimetric quantities, the readout electronic linearity was investigated with three different methods, that is, the first being a single linear regression, the second consisting of a double linear regression with a channel transition and last a multiple linear regression by splitting the data into odd and even groups. The uncertainty related to each of these methods was estimated as well. The edge calibration was performed using the intercept with the horizontal axis of the tangent through the inflection point of the Fermi function approximation multi-channel analyzer spectrum. It was assumed that this point corresponds to the maximum energy difference of particle traversing the sensitive volume (SV) for which the residual range difference in the continuous slowing down approximation is equal to the thickness of the SV of the microdosimeter. Four material conversion methods were explored, the edge method, the density method, the maximum-deposition energy method and the bin-by-bin transformation method. The uncertainties of the microdosimetric quantities resulting from the linearization, the edge calibration and the detectors thickness were also estimated. RESULTS It was found that the double linear regression had the lowest uncertainty for both microdosimeters. The propagated standard (k = 1) uncertainties on the frequency-mean lineal energy y ¯ F ${\bar{y}}_{\rm{F}}$ and the dose-mean lineal energy y ¯ D ${\bar{y}}_{\rm{D}}$ values from the marker point, in the spectra, in the plateau were 0.1% and 0.2%, respectively, for the diamond microdosimeter, whilst for the silicon microdosimeter data converted to diamond, the uncertainty was estimated to be 0.1%. In the range corresponding to the 90% of the amplitude of the Bragg Peak at the distal part of the Bragg curve (R90 ) the uncertainty was found to be 0.1%. The uncertainty propagation from the stopping power tables was estimated to be between 5% and 7% depending on the method. The uncertainty on the y ¯ F ${\bar{y}}_{\rm{F}}$ and y ¯ D ${\bar{y}}_{\rm{D}}$ coming from the thickness of the detectors varied between 0.3% and 0.5%. CONCLUSION This article demonstrate that the linearity of the readout electronics affects the microdosimetric spectra with a difference in y ¯ F ${\bar{y}}_{\rm{F}}$ values between the different linearization methods of up to 17.5%. The combined uncertainty was dominated by the uncertainty of stopping power on the edge.
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Affiliation(s)
| | - Sandra Barna
- Department of Radiation OncologyMedical University of ViennaViennaAustria
| | | | - Linh T. Tran
- Centre for Medical Radiation PhysicsUniversity of WollongongWollongongNew South WalesAustralia
| | - Anatoly Rosenfeld
- Centre for Medical Radiation PhysicsUniversity of WollongongWollongongNew South WalesAustralia
| | - Claudio Verona
- Dipartimento di Ingegneria IndustrialeUniversità di Roma Tor VergataRomaItaly
| | | | - Hugo Palmans
- MedAustron Ion Therapy CenterWiener NeustadtAustria,National Physical LaboratoryTeddingtonTwickenhamUK
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Sakata D, Lee SH, Tran LT, Pan VA, Nakaji T, Mizuno H, Kok A, Povoli M, Rosenfeld AB, Inaniwa T. Microdosimetric investigation for multi-ion therapy by means of silicon on insulator (SOI) microdosimeter. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac8968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 08/12/2022] [Indexed: 11/11/2022]
Abstract
Abstract
[Objective] Ion radiotherapy with protons or carbon ions is one of the most advanced clinical methods for cancer treatment. To further improve the local tumor control, ion radiotherapy using multiple ion species has been investigated. Due to complexity of dose distributions delivered by multi-ion therapy in a tumor, a validation strategy for the planned treatment efficacy must be established that can be potentially used in the quality assurance (QA) protocol for the multi-ion treatment plans. In previous work, we demonstrated that the microdosimetric approach using the silicon on insulator (SOI) microdosimeter is practical for validating cell surviving fraction of MIA PaCa-2 cells in the independent fields of helium, carbon, oxygen, and neon ion beams. [Approach] This paper extends the previous study, and we demonstrate a microdosimetry based approach as a pilot study to build the QA protocol in the multi-ion therapy predicting the cell surviving fraction along the SOBP obtained by combined irradiations of He+O and C+Ne ions. Across the study, the SOI microdosimeter system MicroPlus was used for measurement of the lineal energy in individual ion fields followed by deriving the lineal energy of combined ion fields delivered by a pencil beam scanning system at HIMAC. [Main results] The predicted cell surviving fraction based on derived lineal energy and dose in the combined fields was in good agreement with the planned cell surviving fraction byour in-house treatment planning system (TPS) [Significance] The presented results indicated the potential benefit of the SOI microdosimeter system MicroPlus as the QA system in the multi-ion radiotherapy.
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Akıl C, Ali S, Tran LT, Gaillard J, Li W, Hayashida K, Hirose M, Kato T, Oshima A, Fujishima K, Blanchoin L, Narita A, Robinson RC. Structure and dynamics of Odinarchaeota tubulin and the implications for eukaryotic microtubule evolution. Sci Adv 2022; 8:eabm2225. [PMID: 35333570 PMCID: PMC8956254 DOI: 10.1126/sciadv.abm2225] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 02/03/2022] [Indexed: 06/14/2023]
Abstract
Tubulins are critical for the internal organization of eukaryotic cells, and understanding their emergence is an important question in eukaryogenesis. Asgard archaea are the closest known prokaryotic relatives to eukaryotes. Here, we elucidated the apo and nucleotide-bound x-ray structures of an Asgard tubulin from hydrothermal living Odinarchaeota (OdinTubulin). The guanosine 5'-triphosphate (GTP)-bound structure resembles a microtubule protofilament, with GTP bound between subunits, coordinating the "+" end subunit through a network of water molecules and unexpectedly by two cations. A water molecule is located suitable for GTP hydrolysis. Time course crystallography and electron microscopy revealed conformational changes on GTP hydrolysis. OdinTubulin forms tubules at high temperatures, with short curved protofilaments coiling around the tubule circumference, more similar to FtsZ, rather than running parallel to its length, as in microtubules. Thus, OdinTubulin represents an evolutionary stage intermediate between prokaryotic FtsZ and eukaryotic microtubule-forming tubulins.
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Affiliation(s)
- Caner Akıl
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
- Tokyo Institute of Technology, Earth-Life Science Institute (ELSI), Tokyo 152-8551, Japan
| | - Samson Ali
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Linh T. Tran
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - Jérémie Gaillard
- University of Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, CytoMorpho Lab, 38054 Grenoble, France
| | - Wenfei Li
- National Laboratory of Solid State Microstructure, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, 210093 Nanjing, China
| | - Kenichi Hayashida
- Cellular and Structural Physiology Institute (CeSPI), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Mika Hirose
- Institute for Protein Research, Osaka University, Osaka 565-0871, Japan
| | - Takayuki Kato
- Institute for Protein Research, Osaka University, Osaka 565-0871, Japan
| | - Atsunori Oshima
- Cellular and Structural Physiology Institute (CeSPI), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
- Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
- Institute for Glyco-core Research (iGCORE), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Kosuke Fujishima
- Tokyo Institute of Technology, Earth-Life Science Institute (ELSI), Tokyo 152-8551, Japan
- Graduate School of Media and Governance, Keio University, Fujisawa 252-0882, Japan
| | - Laurent Blanchoin
- University of Grenoble-Alpes, CEA, CNRS, INRA, Interdisciplinary Research Institute of Grenoble, Laboratoire de Physiologie Cellulaire & Végétale, CytoMorpho Lab, 38054 Grenoble, France
- Université de Paris, INSERM, CEA, Institut de Recherche Saint Louis, U 976, CytoMorpho Lab, 75010 Paris, France
| | - Akihiro Narita
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Robert C. Robinson
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong 21210, Thailand
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Vohradsky J, Tran LT, Guatelli S, Chartier L, Vandevoorde C, de Kock EA, Nieto-Camero J, Bolst D, Peracchi S, Höglund C, Rosenfeld AB. Response of SOI microdosimeter in fast neutron beams: experiment and Monte Carlo simulations. Phys Med 2021; 90:176-187. [PMID: 34688192 DOI: 10.1016/j.ejmp.2021.09.008] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 07/30/2021] [Accepted: 09/13/2021] [Indexed: 11/19/2022] Open
Abstract
In this study, Monte Carlo codes, Geant4 and MCNP6, were used to characterize the fast neutron therapeutic beam produced at iThemba LABS in South Africa. Experimental and simulation results were compared using the latest generation of Silicon on Insulator (SOI) microdosimeters from the Centre for Medical Radiation Physics (CMRP). Geant4 and MCNP6 were able to successfully model the neutron gantry and simulate the expected neutron energy spectrum produced from the reaction by protons bombarding a 9Be target. The neutron beam was simulated in a water phantom and its characteristics recorded by the silicon microdosimeters; bare and covered by a 10B enriched boron carbide converter, at different positions. The microdosimetric quantities calculated using Geant4 and MCNP6 are in agreement with experimental measurements. The thermal neutron sensitivity and production of 10B capture products in the p+ boron-implanted dopant regions of the Bridge microdosimeter is investigated. The obtained results are useful for the future development of dedicated SOI microdosimeters for Boron Neutron Capture Therapy (BNCT). This paper provides a benchmark comparison of Geant4 and MCNP6 capabilities in the context of further applications of these codes for neutron microdosimetry.
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Affiliation(s)
- James Vohradsky
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Linh T Tran
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Susanna Guatelli
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Lachlan Chartier
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | | | | | - Jaime Nieto-Camero
- iThemba Laboratory for Accelerator Based Sciences, Cape Town, South Africa
| | - David Bolst
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Stefania Peracchi
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Carina Höglund
- European Spallation Source (ESS), Lund, Sweden; Department of Physics, Thin Film Physics Division, Linköping University, Sweden
| | - Anatoly B Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia.
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James B, Tran LT, Bolst D, Prokopovich DA, Lerch M, Petasecca M, Guatelli S, Povoli M, Kok A, Petringa G, Cirrone GAP, Jackson M, Rosenfeld AB. In-field and out-of-field microdosimetric characterisation of a 62 MeV proton beam at CATANA. Med Phys 2021; 48:4532-4541. [PMID: 33908049 DOI: 10.1002/mp.14905] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [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: 09/21/2020] [Revised: 03/15/2021] [Accepted: 04/04/2021] [Indexed: 11/09/2022] Open
Abstract
PURPOSE A 5 and 10 μm thin silicon on insulator (SOI) 3D mushroom microdosimeter was used to characterize both the in-field and out-of-field of a 62 MeV proton beam. METHODS The SOI mushroom microdosimeter consisted of an array of cylindrical sensitive volumes (SVs), developed by the Centre for Medical Radiation Physics, University of Wollongong, was irradiated with 62 MeV protons at the CATANA (Centro di AdroTerapia Applicazioni Nucleari Avanzate) facility in Catania, Italy, a facility dedicated to the radiation treatment of ocular melanomas. Dose mean lineal energy, ( y D ¯ ), values were obtained at various depths in PMMA along a pristine and spread out Bragg peak (SOBP). The measured microdosimetric spectra at each position were then used as inputs into the modified Microdosimetric Kinetic Model (MKM) to derive the RBE for absorbed dose in a middle of the SOBP 2Gy (RBED ). Microdosimetric spectra were obtained with both the 5 and 10 μm 3D SOI microdosimeters, with a focus on the distal part of the BP. The in-field and out-of-field measurement configurations along the Bragg curve were modeled in Geant4 for comparison with experimental results. Lateral out-of-field measurements were performed to study secondary particles' contribution to normal tissue's dose, up to 12 mm from the edge of the beam field, and quality factor and dose equivalent results were obtained. RESULTS Comparison between experimental and simulation results showed good agreement between one another for both the pristine and SOBP beams in terms of y D ¯ and RBED. Though a small discrepancy between experiment and simulation was seen at the entrance of the Bragg curve, where experimental results were slightly lower than Geant4. The dose equivalent value measured 12 mm from the edge of the target volume was 1.27 ± 0.15 mSv/Gy with a Q ¯ value of 2.52 ± 0.30, both of which agree within uncertainty with Geant4 simulation. CONCLUSIONS These results demonstrate that SOI microdosimeters are an effective tool to predict RBED in-field as well as dose equivalent monitoring out-of-field to provide insight to probability of second cancer generation.
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Affiliation(s)
- Benjamin James
- Centre of Medical and Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Linh T Tran
- Centre of Medical and Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - David Bolst
- Centre of Medical and Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Dale A Prokopovich
- NSTLI Nuclear Stewardship, Australian Nuclear Science and Technology Organization, Lucas Heights, NSW, Australia
| | - Michael Lerch
- Centre of Medical and Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Marco Petasecca
- Centre of Medical and Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - Susanna Guatelli
- Centre of Medical and Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | | | | | | | | | - Michael Jackson
- Centre of Medical and Radiation Physics, University of Wollongong, Wollongong, NSW, Australia.,University of New South Wales, Sydney, NSW, Australia
| | - Anatoly B Rosenfeld
- Centre of Medical and Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
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11
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Bolst D, Guatelli S, Tran LT, Rosenfeld AB. Corrigendum: The impact of sensitive volume thickness for silicon on insulator microdosimeters in hadron therapy (2020 Phys. Med. Biol. 65 035004). Phys Med Biol 2021; 66. [DOI: 10.1088/1361-6560/abe224] [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] [Received: 12/21/2020] [Accepted: 02/01/2021] [Indexed: 11/11/2022]
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12
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Lee SH, Mizushima K, Kohno R, Iwata Y, Yonai S, Shirai T, Pan VA, Bolst D, Tran LT, Rosenfeld AB, Suzuki M, Inaniwa T. Estimating the biological effects of helium, carbon, oxygen, and neon ion beams using 3D silicon microdosimeters. Phys Med Biol 2021; 66:045017. [PMID: 33361575 DOI: 10.1088/1361-6560/abd66f] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In this study, the survival fraction (SF) and relative biological effectiveness (RBE) of pancreatic cancer cells exposed to spread-out Bragg peak helium, carbon, oxygen, and neon ion beams are estimated from the measured microdosimetric spectra using a microdosimeter and the application of the microdosimetric kinetic (MK) model. To measure the microdosimetric spectra, a 3D mushroom silicon-on-insulator microdosimeter connected to low noise readout electronics (MicroPlus probe) was used. The parameters of the MK model were determined for pancreatic cancer cells such that the calculated SFs reproduced previously reported in vitro SF data. For a cuboid target of 10 × 10 × 6 cm3, treatment plans of helium, carbon, oxygen, and neon ion beams were designed using in-house treatment planning software (TPS) to achieve a 10% SF of pancreatic cancer cells throughout the target. The physical doses and microdosimetric spectra of the planned fields were measured at different depths in polymethyl methacrylate phantoms. The biological effects, such as SF, RBE, and RBE-weighted dose at different depths along the fields were predicted from the measurements. The predicted SFs at the target region were generally in good agreement with the planned SF from the TPS in most cases.
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Affiliation(s)
- Sung Hyun Lee
- Department of Accelerator and Medical Physics, National Institute of Radiological Sciences, QST, Japan
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13
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Zhu JL, Tran LT, Smith M, Zheng F, Cai L, James JA, Guthridge JM, Chong BF. Modular gene analysis reveals distinct molecular signatures for subsets of patients with cutaneous lupus erythematosus. Br J Dermatol 2021; 185:563-572. [PMID: 33400293 DOI: 10.1111/bjd.19800] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2021] [Indexed: 12/15/2022]
Abstract
BACKGROUND Cutaneous lupus erythematosus (CLE) is a heterogeneous autoimmune disease with clinical sequelae such as itching, dyspigmentation and scarring. OBJECTIVES We applied a previously described modular analysis approach to assess the molecular heterogeneity of patients with CLE. METHODS Whole-blood transcriptomes of RNA sequencing data from a racially and ethnically diverse group of patients with CLE (n = 62) were used to calculate gene co-expression module scores. An unsupervised cluster analysis and k-means clustering based on these module scores were then performed. We used Fisher's exact tests and Kruskal-Wallis tests to compare characteristics between patient clusters. RESULTS Six unique clusters of patients with CLE were identified from the cluster analysis. We observed that seven inflammation modules were elevated in two clusters of patients with CLE. Additionally, these clusters were characterized by interferon, neutrophil and cell-death signatures, suggesting that interferon-related proteins, neutrophils and cell-death processes could be driving the inflammatory response in these subgroups. Three different clusters had a predominant T-cell signature, which were supported by lymphocyte counts. CONCLUSIONS Our data support a diverse molecular profile in CLE that further adds to the clinical variations of this skin disease, and may affect disease course and treatment selection. Future studies with a larger and diverse cohort of patients with CLE are warranted to confirm these findings.
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Affiliation(s)
- J L Zhu
- Department of Dermatology, University of Texas at Southwestern Medical Center, Dallas, TX, USA
| | - L T Tran
- Arthritis and Clinical Research Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - M Smith
- Arthritis and Clinical Research Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - F Zheng
- Arthritis and Clinical Research Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - L Cai
- Department of Population and Data Sciences, Quantitative Biomedical Research Center, Dallas, TX, USA
| | - J A James
- Arthritis and Clinical Research Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - J M Guthridge
- Arthritis and Clinical Research Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - B F Chong
- Department of Dermatology, University of Texas at Southwestern Medical Center, Dallas, TX, USA
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Bustos MA, Gross R, Rahimzadeh N, Cole H, Tran LT, Tran KD, Takeshima L, Stern SL, O’Day S, Hoon DSB. A Pilot Study Comparing the Efficacy of Lactate Dehydrogenase Levels Versus Circulating Cell-Free microRNAs in Monitoring Responses to Checkpoint Inhibitor Immunotherapy in Metastatic Melanoma Patients. Cancers (Basel) 2020; 12:cancers12113361. [PMID: 33202891 PMCID: PMC7696545 DOI: 10.3390/cancers12113361] [Citation(s) in RCA: 15] [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] [Received: 09/09/2020] [Accepted: 11/09/2020] [Indexed: 12/18/2022] Open
Abstract
Simple Summary Improvement in melanoma patients with metastatic disease is needed to better assess immunotherapies. Lactate dehydrogenase (LDH) is currently an accepted biomarker for stage IV, but it has limited utility for stage III melanoma patients. Thus, finding biomarkers for metastatic melanoma is important not only to identify progressive melanoma tumors, but also to monitor patients under checkpoint inhibitor immunotherapy (CII). The aim of this pilot study was to demonstrate the utility of circulating cell-free microRNAs (cfmiRs) as potential blood biomarkers for stage III and IV melanoma patients compared to LDH. To accomplish this aim, we profiled for cfmiR the plasma of metastatic melanoma patients before and during CII treatment, and compared them to normal healthy donors’ samples. The cfmiR profiling was performed using an NGS-based miRNA assay, which requires no extraction and a small volume input. We found specific cfmiR signatures in stage III and IV metastatic melanoma patients. As a proof of concept, our results showed that certain cfmiRs are associated with CII outcomes. Abstract Serum lactate dehydrogenase (LDH) is a standard prognostic biomarker for stage IV melanoma patients. Often, LDH levels do not provide real-time information about the metastatic melanoma patients’ disease status and treatment response. Therefore, there is a need to find reliable blood biomarkers for improved monitoring of metastatic melanoma patients who are undergoing checkpoint inhibitor immunotherapy (CII). The objective in this prospective pilot study was to discover circulating cell-free microRNA (cfmiR) signatures in the plasma that could assess melanoma patients’ responses during CII. The cfmiRs were evaluated by the next-generation sequencing (NGS) HTG EdgeSeq microRNA (miR) Whole Transcriptome Assay (WTA; 2083 miRs) in 158 plasma samples obtained before and during the course of CII from 47 AJCC stage III/IV melanoma patients’ and 73 normal donors’ plasma samples. Initially, cfmiR profiles for pre- and post-treatment plasma samples of stage IV non-responder melanoma patients were compared to normal donors’ plasma samples. Using machine learning, we identified a 9 cfmiR signature that was associated with stage IV melanoma patients being non-responsive to CII. These cfmiRs were compared in pre- and post-treatment plasma samples from stage IV melanoma patients that showed good responses. Circulating miR-4649-3p, miR-615-3p, and miR-1234-3p demonstrated potential prognostic utility in assessing CII responses. Compared to LDH levels during CII, circulating miR-615-3p levels were consistently more efficient in detecting melanoma patients undergoing CII who developed progressive disease. By combining stage III/IV patients, 92 and 17 differentially expressed cfmiRs were identified in pre-treatment plasma samples from responder and non-responder patients, respectively. In conclusion, this pilot study demonstrated cfmiRs that identified treatment responses and could allow for real-time monitoring of patients receiving CII.
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Affiliation(s)
- Matias A. Bustos
- Department of Translational Molecular Medicine, John Wayne Cancer Institute (JWCI), Providence Saint John’s Health Center (SJHC), Santa Monica, CA 90404, USA; (R.G.); (N.R.); (L.T.); (D.S.B.H.)
- Correspondence:
| | - Rebecca Gross
- Department of Translational Molecular Medicine, John Wayne Cancer Institute (JWCI), Providence Saint John’s Health Center (SJHC), Santa Monica, CA 90404, USA; (R.G.); (N.R.); (L.T.); (D.S.B.H.)
| | - Negin Rahimzadeh
- Department of Translational Molecular Medicine, John Wayne Cancer Institute (JWCI), Providence Saint John’s Health Center (SJHC), Santa Monica, CA 90404, USA; (R.G.); (N.R.); (L.T.); (D.S.B.H.)
| | - Hunter Cole
- Department of Immuno-Oncology and Clinical Research, JWCI, Providence SJHC, Santa Monica, CA 90404, USA; (H.C.); O' (S.O.)
| | - Linh T. Tran
- Department of Genomic Sequencing Center, JWCI, Providence SJHC, Santa Monica, CA 90404, USA; (L.T.T.); (K.D.T.)
| | - Kevin D. Tran
- Department of Genomic Sequencing Center, JWCI, Providence SJHC, Santa Monica, CA 90404, USA; (L.T.T.); (K.D.T.)
| | - Ling Takeshima
- Department of Translational Molecular Medicine, John Wayne Cancer Institute (JWCI), Providence Saint John’s Health Center (SJHC), Santa Monica, CA 90404, USA; (R.G.); (N.R.); (L.T.); (D.S.B.H.)
| | - Stacey L. Stern
- Department of Biostatistics, JWCI, Providence SJHC, Santa Monica, CA 90404, USA;
| | - Steven O’Day
- Department of Immuno-Oncology and Clinical Research, JWCI, Providence SJHC, Santa Monica, CA 90404, USA; (H.C.); O' (S.O.)
| | - Dave S. B. Hoon
- Department of Translational Molecular Medicine, John Wayne Cancer Institute (JWCI), Providence Saint John’s Health Center (SJHC), Santa Monica, CA 90404, USA; (R.G.); (N.R.); (L.T.); (D.S.B.H.)
- Department of Genomic Sequencing Center, JWCI, Providence SJHC, Santa Monica, CA 90404, USA; (L.T.T.); (K.D.T.)
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15
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Brooks JK, Kim E, Tran LT, Vieira CA, Price JB. Odontoma associated with mandibular transmigrated canine in a geriatric patient: Second case report. Gerodontology 2020; 37:411-415. [PMID: 33179813 DOI: 10.1111/ger.12495] [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: 06/26/2020] [Revised: 08/13/2020] [Accepted: 08/15/2020] [Indexed: 11/26/2022]
Abstract
OBJECTIVE This report discusses the clinical relevance of a novel case of an odontoma and transmigrated canine in the setting of florid cemento-osseous dysplasia (COD), hypercementosis and moderate to severe periodontitis in a 66-year-old patient. BACKGROUND An odontoma may infrequently impede tooth eruption and rarely has been implicated with canine transmigration. COD is a benign fibro-osseous lesion associated with decreased vascularity and poorer surgical intervention. MATERIALS AND METHODS A partially edentulous woman, in no acute distress, underwent clinical and radiographic evaluation in pursuit of comprehensive dental care. RESULTS Radiographic assessment demonstrated multiple occult pathologies of the mandible, including compound odontoma, canine transmigration, florid COD, hypercementosis and moderate to severe periodontitis, a concurrence thought to be previously unreported. Furthermore, the presence of the odontoma and transmigrated canine is apparently the second reported case in the geriatric population. CONCLUSIONS The attending clinician should carefully weigh removal of an impacted and transmigrated canine associated with an odontoma in the setting of COD and compromised bone, particularly in older individuals. When surgical intervention is deferred in these clinical situations, patients should continue to be monitored for clinical and radiographic development of pathologic processes.
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Affiliation(s)
- John K Brooks
- Department of Oncology and Diagnostic Sciences, University of Maryland School of Dentistry, Baltimore, MD, USA
| | - Eunlim Kim
- University of Maryland School of Dentistry, Baltimore, MD, USA
| | - Linh T Tran
- University of Maryland School of Dentistry, Baltimore, MD, USA
| | | | - Jeffery B Price
- Department of Oncology and Diagnostic Sciences, University of Maryland School of Dentistry, Baltimore, MD, USA
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16
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Dermer E, Spahr A, Tran LT, Mirchi A, Pelletier F, Guerrero K, Ahmed S, Brais B, Braverman N, Buhas D, Chandratre S, Chenier S, Chrestian N, Desmeules M, Dilenge ME, Laflamme J, Larbrisseau A, Legault G, Lim KY, Maftei C, Major P, Malvey-Dorn E, Marois P, Mitchell J, Nadeau A, Osterman B, Paradis I, Pohl D, Reggin J, Riou E, Roedde G, Rossignol E, Sébire G, Shevell M, Srour M, Sylvain M, Tarnopolsky M, Venkateswaran S, Sullivan M, Bernard G. Stress in Parents of Children With Genetically Determined Leukoencephalopathies: A Pilot Study. J Child Neurol 2020; 35:901-907. [PMID: 32720856 DOI: 10.1177/0883073820938645] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Genetically determined leukoencephalopathies comprise a group of rare inherited white matter disorders. The majority are progressive diseases resulting in early death. We performed a cross-sectional pilot study including 55 parents from 36 families to assess the level of stress experienced by parents of patients with genetically determined leukoencephalopathies, aged 1 month to 12 years. Thirty-four mothers and 21 fathers completed the Parenting Stress Index-4th Edition. One demographic questionnaire was completed per family. Detailed clinical data was gathered on all patients. Statistical analysis was performed with total stress percentile score as the primary outcome. Mothers and fathers had significantly higher stress levels compared with the normative sample; 20% of parents had high levels of stress whereas 11% had clinically significant levels of stress. Mothers and fathers had comparable total stress percentile scores. We identified pediatric behavioral difficulties and gross motor function to be factors influencing stress in mothers. Our study is the first to examine parental stress in this population and highlights the need for parental support early in the disease course. In this pilot study, we demonstrated that using the Parenting Stress Index-4th Edition to assess stress levels in parents of patients with genetically determined leukoencephalopathies is feasible, leads to valuable and actionable results, and should be used in larger, prospective studies.
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Affiliation(s)
- E Dermer
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Department of Specialized Medicine, Division of Medical Genetics, 507266McGill University Health Centre, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada.,E. Dermer and A. Spahr are co-first authors of this article
| | - A Spahr
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Department of Specialized Medicine, Division of Medical Genetics, 507266McGill University Health Centre, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada.,E. Dermer and A. Spahr are co-first authors of this article
| | - L T Tran
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Department of Specialized Medicine, Division of Medical Genetics, 507266McGill University Health Centre, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - A Mirchi
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Department of Specialized Medicine, Division of Medical Genetics, 507266McGill University Health Centre, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - F Pelletier
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Department of Specialized Medicine, Division of Medical Genetics, 507266McGill University Health Centre, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - K Guerrero
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Department of Specialized Medicine, Division of Medical Genetics, 507266McGill University Health Centre, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - S Ahmed
- 27364North Bay Regional Health Centre, North Bay, Ontario, Canada
| | - B Brais
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada
| | - N Braverman
- Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - D Buhas
- Department of Specialized Medicine, Division of Medical Genetics, 507266McGill University Health Centre, Montréal, Québec, Canada
| | - S Chandratre
- Department of Pediatric Neurology, 6397Oxford University Hospitals, Oxford, United Kingdom
| | - S Chenier
- Department of Medical Genetics, 7321University of Sherbrooke, Sherbrooke, Québec, Canada
| | - N Chrestian
- Division of Pediatric Neurology, 12369Centre Mère-Enfant Soleil du CHU de Québec-Université Laval, Québec, Canada.,Department of Pediatrics, 12369Centre Mère-Enfant Soleil du CHU de Québec-Université Laval, Québec, Canada
| | - M Desmeules
- Department of Pediatrics, Saguenay, Chicoutimi, Québec, Canada
| | - M E Dilenge
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada
| | - J Laflamme
- Department of Pediatrics, 12369Centre Mère-Enfant Soleil du CHU de Québec-Université Laval, Québec, Canada
| | - A Larbrisseau
- Department of Pediatrics, 5622University of Montreal, Montréal, Québec, Canada.,Department of Neurology, CHU Saint-Justine, Montréal, Québec, Canada
| | - G Legault
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada
| | - K Y Lim
- Department of Pediatric Neurology, Providence Pediatric Neurology-St. Vincent, Portland, OR, USA
| | - C Maftei
- Department of Pediatrics, Division of Medical Genetics, CHU Saint-Justine, Montreal University, Montréal, Québec, Canada
| | - P Major
- Department of Pediatrics, 5622University of Montreal, Montréal, Québec, Canada
| | - E Malvey-Dorn
- Department of Pediatrics, All About Children Pediatrics Eden Prairie, St. Louis Park, MN, USA
| | - P Marois
- Department of Pediatrics, 5622University of Montreal, Montréal, Québec, Canada
| | - J Mitchell
- Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - A Nadeau
- Department of Pediatric Neurology, University of Sherbrooke, Sherbrooke, Québec, Canada
| | - B Osterman
- Department of Pediatrics, 5622University of Montreal, Montréal, Québec, Canada.,Department of Neurology, CHU Saint-Justine, Montréal, Québec, Canada
| | - I Paradis
- CIUSSS de l'Est-de-l'Île-de-Montréal, CLSC de Rivière-des-Prairies, Montréal, Québec, Canada
| | - D Pohl
- Division of Neurology, 274065Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario, Canada
| | - J Reggin
- Department of Pediatric Neurology, Providence Child Neurology, Spokane, Washington, United States
| | - E Riou
- Department of Pediatric Neurology, University of Sherbrooke, Sherbrooke, Québec, Canada
| | - G Roedde
- Latchford Medical Centre, Latchford, Ontario, Canada
| | - E Rossignol
- Brain and Child Development, CHU Saint-Justine Research Center, Montréal, Québec, Canada
| | - G Sébire
- Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - M Shevell
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - M Srour
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - M Sylvain
- Division of Pediatric Neurology, 12369Centre Mère-Enfant Soleil du CHU de Québec-Université Laval, Québec, Canada.,Department of Pediatrics, 12369Centre Mère-Enfant Soleil du CHU de Québec-Université Laval, Québec, Canada
| | - M Tarnopolsky
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - S Venkateswaran
- Department of Pediatrics, CHEO Research Institute, Ottawa, Ontario, Canada
| | - M Sullivan
- Department of Psychology, McGill University, Montréal, Québec, Canada
| | - G Bernard
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Department of Specialized Medicine, Division of Medical Genetics, 507266McGill University Health Centre, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
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Akıl C, Kitaoku Y, Tran LT, Liebl D, Choe H, Muengsaen D, Suginta W, Schulte A, Robinson RC. Mythical origins of the actin cytoskeleton. Curr Opin Cell Biol 2020; 68:55-63. [PMID: 33049465 DOI: 10.1016/j.ceb.2020.08.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 08/13/2020] [Accepted: 08/17/2020] [Indexed: 10/23/2022]
Abstract
The origin of the eukaryotic cell is one of the greatest mysteries in modern biology. Eukaryotic-wide specific biological processes arose in the lost ancestors of eukaryotes. These distinctive features, such as the actin cytoskeleton, define what it is to be a eukaryote. Recent sequencing, characterization, and isolation of Asgard archaea have opened an intriguing window into the pre-eukaryotic cell. Firstly, sequencing of anaerobic sediments identified a group of uncultured organisms, Asgard archaea, which contain genes with homology to eukaryotic signature genes. Secondly, characterization of the products of these genes at the protein level demonstrated that Asgard archaea have related biological processes to eukaryotes. Finally, the isolation of an Asgard archaeon has produced a model organism in which the morphological consequences of the eukaryotic-like processes can be studied. Here, we consider the consequences for the Asgard actin cytoskeleton and for the evolution of a regulated actin system in the archaea-to-eukaryotic transition.
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Affiliation(s)
- Caner Akıl
- Institute of Molecular and Cell Biology, A∗STAR (Agency for Science, Technology and Research), Biopolis, 138673, Singapore; Tokyo Institute of Technology, Earth-Life Science Institute (ELSI), Tokyo 152-8551, Japan
| | - Yoshihito Kitaoku
- Research Institute for Interdisciplinary Science (RIIS), Okayama University, Okayama 700-8530, Japan
| | - Linh T Tran
- Research Institute for Interdisciplinary Science (RIIS), Okayama University, Okayama 700-8530, Japan
| | - David Liebl
- A∗STAR Microscopy Platform, Research Support Center, A∗STAR, Biopolis 138673, Singapore
| | - Han Choe
- Department of Physiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, 05505, South Korea
| | - Duangkamon Muengsaen
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong 21210, Thailand
| | - Wipa Suginta
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong 21210, Thailand
| | - Albert Schulte
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong 21210, Thailand
| | - Robert C Robinson
- Institute of Molecular and Cell Biology, A∗STAR (Agency for Science, Technology and Research), Biopolis, 138673, Singapore; Research Institute for Interdisciplinary Science (RIIS), Okayama University, Okayama 700-8530, Japan; School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong 21210, Thailand.
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Cameron MJ, Davis JA, Dipuglia A, Chartier L, Tran LT, Prokopovich DA, Petasecca M, Perevertaylo VL, Rosenfeld AB, Lerch MLF. Characterization of 3-D-Mesa Silicon Single Strip Detectors for Use in Synchrotron Microbeam Radiation Therapy. IEEE Trans Radiat Plasma Med Sci 2020. [DOI: 10.1109/trpms.2019.2948466] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Bustos MA, Tran KD, Rahimzadeh N, Gross R, Lin SY, Shoji Y, Murakami T, Boley CL, Tran LT, Cole H, Kelly DF, O’Day S, Hoon DSB. Integrated Assessment of Circulating Cell-Free MicroRNA Signatures in Plasma of Patients with Melanoma Brain Metastasis. Cancers (Basel) 2020; 12:E1692. [PMID: 32630542 PMCID: PMC7352246 DOI: 10.3390/cancers12061692] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/23/2020] [Accepted: 06/23/2020] [Indexed: 12/11/2022] Open
Abstract
Primary cutaneous melanoma frequently metastasizes to distant organs including the brain. Identification of cell-free microRNAs (cfmiRs) found in the blood can be used as potential body fluid biomarkers for detecting and monitoring patients with melanoma brain metastasis (MBM). In this pilot study, we initially aimed to identify cfmiRs in the blood of MBM patients. Normal donors plasma (healthy, n = 48) and pre-operative MBM patients' plasma samples (n = 36) were compared for differences in >2000 microRNAs (miRs) using a next generation sequencing (NGS) probe-based assay. A 74 cfmiR signature was identified in an initial cohort of MBM plasma samples and then verified in a second cohort of MBM plasma samples (n = 24). Of these, only 58 cfmiRs were also detected in MBM tissues (n = 24). CfmiR signatures were also found in patients who have lung and breast cancer brain metastasis (n = 13) and glioblastomas (n = 36) compared to MBM plasma samples. The 74 cfmiR signature and the latter cfmiR signatures were then compared. We found a 6 cfmiR signature that was commonly upregulated in MBM plasma samples in all of the comparisons, and a 29 cfmiR signature that distinguishes MBM patients from normal donors' samples. In addition, we assessed for cfmiRs in plasma (n = 20) and urine (n = 14) samples collected from metastatic melanoma patients receiving checkpoint inhibitor immunotherapy (CII). Pre- and post-treatment samples showed consistent changes in cfmiRs. Analysis of pre- and post-treatment plasma samples showed 8 differentially expressed (DE) cfmiRs that overlapped with the 35 cfmiR signature found in MBM patients. In paired pre-treatment plasma and urine samples receiving CII 8 cfmiRs overlapped. This study identified specific cfmiRs in MBM plasma samples that may potentially allow for assessment of melanoma patients developing MBM. The cfmiR signatures identified in both blood and urine may have potential utility to assess CII responses after further validation.
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Affiliation(s)
- Matias A. Bustos
- Department of Translational Molecular Medicine, John Wayne Cancer Institute at Providence Saint John’s Health Center, Santa Monica, CA 90404, USA; (M.A.B.); (N.R.); (R.G.); (S.Y.L.); (Y.S.); (T.M.)
| | - Kevin D. Tran
- Department of Genomic Sequencing Center, John Wayne Cancer Institute at Providence Saint John’s Health Center, Santa Monica, CA 90404, USA; (K.D.T.); (L.T.T.)
| | - Negin Rahimzadeh
- Department of Translational Molecular Medicine, John Wayne Cancer Institute at Providence Saint John’s Health Center, Santa Monica, CA 90404, USA; (M.A.B.); (N.R.); (R.G.); (S.Y.L.); (Y.S.); (T.M.)
| | - Rebecca Gross
- Department of Translational Molecular Medicine, John Wayne Cancer Institute at Providence Saint John’s Health Center, Santa Monica, CA 90404, USA; (M.A.B.); (N.R.); (R.G.); (S.Y.L.); (Y.S.); (T.M.)
| | - Selena Y. Lin
- Department of Translational Molecular Medicine, John Wayne Cancer Institute at Providence Saint John’s Health Center, Santa Monica, CA 90404, USA; (M.A.B.); (N.R.); (R.G.); (S.Y.L.); (Y.S.); (T.M.)
| | - Yoshiaki Shoji
- Department of Translational Molecular Medicine, John Wayne Cancer Institute at Providence Saint John’s Health Center, Santa Monica, CA 90404, USA; (M.A.B.); (N.R.); (R.G.); (S.Y.L.); (Y.S.); (T.M.)
| | - Tomohiro Murakami
- Department of Translational Molecular Medicine, John Wayne Cancer Institute at Providence Saint John’s Health Center, Santa Monica, CA 90404, USA; (M.A.B.); (N.R.); (R.G.); (S.Y.L.); (Y.S.); (T.M.)
| | - Christine L. Boley
- Department of Immuno-Oncology and Clinical Research, John Wayne Cancer Institute, Santa Monica, CA 90404, USA; (C.L.B.); (H.C.); O’
| | - Linh T. Tran
- Department of Genomic Sequencing Center, John Wayne Cancer Institute at Providence Saint John’s Health Center, Santa Monica, CA 90404, USA; (K.D.T.); (L.T.T.)
| | - Hunter Cole
- Department of Immuno-Oncology and Clinical Research, John Wayne Cancer Institute, Santa Monica, CA 90404, USA; (C.L.B.); (H.C.); O’
| | - Daniel F. Kelly
- Pacific Neuroscience Institute, John Wayne Cancer Institute, Saint John’s Health Center, Santa Monica, CA 90404, USA;
| | - Steven O’Day
- Department of Immuno-Oncology and Clinical Research, John Wayne Cancer Institute, Santa Monica, CA 90404, USA; (C.L.B.); (H.C.); O’
| | - Dave S. B. Hoon
- Department of Translational Molecular Medicine, John Wayne Cancer Institute at Providence Saint John’s Health Center, Santa Monica, CA 90404, USA; (M.A.B.); (N.R.); (R.G.); (S.Y.L.); (Y.S.); (T.M.)
- Department of Genomic Sequencing Center, John Wayne Cancer Institute at Providence Saint John’s Health Center, Santa Monica, CA 90404, USA; (K.D.T.); (L.T.T.)
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Brooks JK, Tran LT, Basile JR, Khoury ZH, Wu LL, Price JB. Synchronous gubernacular canals with compound odontoma associated with a calcifying odontogenic cyst and transmigrated canine: An extremely rare event. Pediatric Dental Journal 2020. [DOI: 10.1016/j.pdj.2019.12.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Bolst D, Guatelli S, Tran LT, Chartier L, Davis J, Biasi G, Prokopovich DA, Pogossov A, Reinhard MI, Petasecca M, Lerch MLF, Matsufuji N, Povoli M, Summanwar A, Kok A, Jackson M, Rosenfeld AB. Validation of Geant4 for silicon microdosimetry in heavy ion therapy. ACTA ACUST UNITED AC 2020; 65:045014. [DOI: 10.1088/1361-6560/ab586a] [Citation(s) in RCA: 8] [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] [Indexed: 11/11/2022]
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Bolst D, Guatelli S, Tran LT, Rosenfeld AB. The impact of sensitive volume thickness for silicon on insulator microdosimeters in hadron therapy. Phys Med Biol 2020; 65:035004. [PMID: 31842007 DOI: 10.1088/1361-6560/ab623f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Compact silicon on insulator (SOI) microdosimeters have been used to characterise the radiation field of many different hadron therapy beams. SOI devices are particularly attractive in hadron therapy fields due to their spatial resolution being well suited to the sharp dose gradients at the end of the primary beam's range. Due to the small size of SOI's sensitive volumes (SVs), which are usually ∼1-10 [Formula: see text]m thick, the fabrication of these devices can present challenges which are not as common for more conventional thickness silicon devices such as silicon spectroscopy detectors. Microdosimetry is the study of the energy deposition in micrometre sized volumes representing biological sites and is a powerful approach to estimate the biological effect of radiation on the micron-scale level, in a cell. However, cell sizes vary extensively translating in different energy deposition spectra. This work studies SV thicknesses between 1 and 100 [Formula: see text]m using Geant4 and examines the impact of SV dimensions on microdosimetric quantities. The quantities studied were the frequency mean lineal energy, [Formula: see text], and the dose mean lineal energy, [Formula: see text]. Additionally the relative biological effectiveness (RBE), estimated by the microdosimetric kinetic model (MKM), is also investigated. To study the impact of the SV thickness, SOI microdosimeters were irradiated with proton, [Formula: see text] and [Formula: see text] ion beams with ranges of ∼160 mm, with the microdosimeter being set at various positions along the Bragg curve. It was found that [Formula: see text] was influenced the least in proton beams and increased for heavier ion beams. Conversely, [Formula: see text] was impacted by the SV thickness the most in proton beams and [Formula: see text] was the least. Similar to [Formula: see text], protons were impacted the most by the SV thickness when estimating the RBE using the MKM. The cause of these differences was largely due to the different densities of the delta electron track structure for the case of [Formula: see text] and the energy transferred to the medium from the primary beam for [Formula: see text].
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Affiliation(s)
- D Bolst
- Author to whom any correspondence should be addressed
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Wagenaar D, Tran LT, Meijers A, Marmitt GG, Souris K, Bolst D, James B, Biasi G, Povoli M, Kok A, Traneus E, van Goethem MJ, Langendijk JA, Rosenfeld AB, Both S. Validation of linear energy transfer computed in a Monte Carlo dose engine of a commercial treatment planning system. Phys Med Biol 2020; 65:025006. [PMID: 31801119 DOI: 10.1088/1361-6560/ab5e97] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The relative biological effectiveness (RBE) of protons is highly variable and difficult to quantify. However, RBE is related to the local ionization density, which can be related to the physical measurable dose weighted linear energy transfer (LETD). The aim of this study was to validate the LETD calculations for proton therapy beams implemented in a commercially available treatment planning system (TPS) using microdosimetry measurements and independent LETD calculations (Open-MCsquare (MCS)). The TPS (RayStation v6R) was used to generate treatment plans on the CIRS-731-HN anthropomorphic phantom for three anatomical sites (brain, nasopharynx, neck) for a spherical target (Ø = 5 cm) with uniform target dose to calculate the LETD distribution. Measurements were performed at the University Medical Center Groningen proton therapy center (Proteus Plus, IBA) using a µ +-probe utilizing silicon on insulator microdosimeters capable of detecting lineal energies as low as 0.15 keV µm-1 in tissue. Dose averaged mean lineal energy [Formula: see text] depth-profiles were measured for 70 and 130 MeV spots in water and for the three treatment plans in water and an anthropomorphic phantom. The [Formula: see text] measurements were compared to the LETD calculated in the TPS and MCS independent dose calculation engine. D · [Formula: see text] was compared to D · LETD in terms of a gamma-index with a distance-to-agreement criteria of 2 mm and increasing dose difference criteria to determine the criteria for which a 90% pass rate was accomplished. Measurements of D · [Formula: see text] were in good agreement with the D · LETD calculated in the TPS and MCS. The 90% passing rate threshold was reached at different D · LETD difference criteria for single spots (TPS: 1% MCS: 1%), treatment plans in water (TPS: 3% MCS: 6%) and treatment plans in an anthropomorphic phantom (TPS: 6% MCS: 1%). We conclude that D · LETD calculations accuracy in the RayStation TPS and open MCSquare are within 6%, and sufficient for clinical D · LETD evaluation and optimization. These findings remove an important obstacle in the road towards clinical implementation of D · LETD evaluation and optimization of proton therapy treatment plans. Novelty and significance The dose weighed linear energy transfer (LETD) distribution can be calculated for proton therapy treatment plans by Monte Carlo dose engines. The relative biological effectiveness (RBE) of protons is known to vary with the LETD distribution. Therefore, there exists a need for accurate calculation of clinical LETD distributions. Previous LETD validations have focused on general purpose Monte Carlo dose engines which are typically not used clinically. We present the first validation of mean lineal energy [Formula: see text] measurements of the LETD against calculations by the Monte Carlo dose engines of the Raystation treatment planning system and open MCSquare.
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Affiliation(s)
- Dirk Wagenaar
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. Author to whom any correspondence should be addressed
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Vu HT, Tran LT, Le GH, Nguyen QK, Vu TM, Vu TA. Synthesis and application of novel Fe-MIL-53/GO nanocomposite for photocatalytic degradation of reactive dye from aqueous solution. VJCH 2020. [DOI: 10.1002/vjch.201900055] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Hoa T. Vu
- Hanoi University of Industry; 298 Cau Dien Street, Minh Khai Ward, North Tu Liem Hanoi 10000 Viet Nam
- Graduate University of Science and Technology - Vietnam Academy of Science and Technology; 18 Hoang Quoc Viet, Cau Giay Hanoi 10000 Viet Nam
| | - Linh T. Tran
- Hanoi University of Industry; 298 Cau Dien Street, Minh Khai Ward, North Tu Liem Hanoi 10000 Viet Nam
| | - Giang H. Le
- Institute of Chemistry, Vietnam Academy of Science and Technology; 18 Hoang Quoc Viet, Cau Giay Hanoi 10000 Viet Nam
| | - Quang K. Nguyen
- Institute of Chemistry, Vietnam Academy of Science and Technology; 18 Hoang Quoc Viet, Cau Giay Hanoi 10000 Viet Nam
| | - Tan M. Vu
- Hanoi University of Industry; 298 Cau Dien Street, Minh Khai Ward, North Tu Liem Hanoi 10000 Viet Nam
| | - Tuan A. Vu
- Institute of Chemistry, Vietnam Academy of Science and Technology; 18 Hoang Quoc Viet, Cau Giay Hanoi 10000 Viet Nam
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Han S, Yoo SH, Shin JI, Kim EH, Jung WG, Kim KB, Matsumura A, Kanai T, Tran LT, Chartier L, James B, Rosenfeld AB. Study on the RBE estimation for carbon beam scanning irradiation using a solid-state microdosimeter. Med Phys 2019; 47:363-370. [PMID: 31732963 DOI: 10.1002/mp.13924] [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: 12/04/2018] [Revised: 11/07/2019] [Accepted: 11/07/2019] [Indexed: 11/08/2022] Open
Abstract
PURPOSE The purpose of this study was to study the field size effect on the estimated Relative Biological Effectiveness (RBE) for carbon scanning beam irradiation. METHODS A silicon-on-insulator (SOI) microdosimeter system developed by the Centre for Medical Radiation Physics, University of Wollongong, Australia, was used for lineal-energy measurements (microdosimetric quantity). The RBE values were derived based on the modified microdosimetric kinetic model (MKM) at different depths in a water phantom in the scanning carbon beam for various scanned areas. RESULTS Our study shows that the difference in RBE values derived from the SOI microdosimeter measurements with the MKM model and from the Treatment Planning System (TPS). The difference of the RBE values is within 6.5 % at the peak point of the spread-out Bragg Peak (SOBP) region. Compared to the spot-beam, RBE values obtained in the scanned-beam with a larger scanned area of 1.0 × 1.0 cm2 have better agreement with which estimated by the TPS. CONCLUSIONS This study shows the possibility of using the SOI microdosimeter system as a quality assurance (QA) tool for RBE evaluation in carbon-pencil beam scanning radiotherapy.
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Affiliation(s)
- Soorim Han
- Division of Heavy-Ion Clinical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Seung Hoon Yoo
- Division of Heavy-Ion Clinical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Jae Ik Shin
- Division of Heavy-Ion Clinical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Eun Ho Kim
- Division of Heavy-Ion Clinical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Won-Gyun Jung
- Division of Heavy-Ion Clinical Research, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | - Kum Bae Kim
- Department of Radiation Oncology, Korea Institute of Radiological and Medical Sciences, Seoul, Korea
| | | | | | - Linh T Tran
- Center for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Lachlan Chartier
- Center for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Benjamin James
- Center for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Anatoly B Rosenfeld
- Center for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
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Vohradsky J, Guatelli S, Davis JA, Tran LT, Rosenfeld AB. Evaluation of silicon based microdosimetry for Boron Neutron Capture Therapy Quality Assurance. Phys Med 2019; 66:8-14. [PMID: 31541864 DOI: 10.1016/j.ejmp.2019.09.072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 09/02/2019] [Accepted: 09/06/2019] [Indexed: 11/28/2022] Open
Abstract
The shift from reactor to accelerator based neutron production has created a renewed interested in Boron Neutron Capture Therapy (BNCT). BNCT is reliant upon the favourable uptake of 10B by tumour cells along with the interaction with neutrons to produce high LET fragments (He and Li nuclei) that deposit energy locally within the tumour cells. As with any radiation based treatment, Quality Assurance (QA) is crucial. In particular, Geant4 was used to model and optimise the geometry and packaging of Silicon on Insulator (SOI) microdosimeters for BNCT Quality Assurance purposes in view of experimental measurements at the KUR research reactor, in Japan. In this context, design optimisation pertains to the sensitive volume size and probability of neutron activation. This study has shown conclusively that whilst the materials currently used in the fabrication of silicon based microdosimeters are appropriate, there are changes with respect to the sensitive volume thickness that should be addressed to reduce the number of 'stoppers' in the microdosimeter.
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Affiliation(s)
- James Vohradsky
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Susanna Guatelli
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia.
| | - Jeremy A Davis
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Linh T Tran
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Anatoly B Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
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Zhu H, Chen Y, Sung W, McNamara AL, Tran LT, Burigo LN, Rosenfeld AB, Li J, Faddegon B, Schuemann J, Paganetti H. The microdosimetric extension in TOPAS: development and comparison with published data. Phys Med Biol 2019; 64:145004. [PMID: 31117056 DOI: 10.1088/1361-6560/ab23a3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Microdosimetric energy depositions have been suggested as a key variable for the modeling of the relative biological effectiveness (RBE) in proton and ion radiation therapy. However, microdosimetry has been underutilized in radiation therapy. Recent advances in detector technology allow the design of new mico- and nano-dosimeters. At the same time Monte Carlo (MC) simulations have become more widely used in radiation therapy. In order to address the growing interest in the field, a microdosimetric extension was developed in TOPAS. The extension provides users with the functionality to simulate microdosimetric spectra as well as the contribution of secondary particles to the spectra, calculate microdosimetric parameters, and determine RBE with a biological weighting function approach or with the microdosimetric kinetic (MK) model. Simulations were conducted with the extension and the results were compared with published experimental data and other simulation results for three types of microdosimeters, a spherical tissue equivalent proportional counter (TEPC), a cylindrical TEPC and a solid state microdosimeter. The corresponding microdosimetric spectra obtained with TOPAS from the plateau region to the distal tail of the Bragg curve generally show good agreement with the published data.
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Affiliation(s)
- Hongyu Zhu
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114, United States of America. Department of Engineering Physics, Tsinghua University, Beijing 100084, People's Republic of China. Key Laboratory of Particle and Radiation Imaging (Tsinghua University), Ministry of Education, Beijing 100084, People's Republic of China
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Peracchi S, Guatelli S, Tran LT, Rosenfeld AB. Simulation of cosmic radiation spectra for personal microdosimetry at the International Space Station’s altitude. ACTA ACUST UNITED AC 2019. [DOI: 10.1088/1742-6596/1154/1/012020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Würl M, Englbrecht FS, Lehrack S, Gianoli C, Lindner FH, Rösch TF, Haffa D, Olivari F, Petasecca M, Lerch MLF, Pogossov A, Tran LT, Assmann W, Schreiber J, Rosenfeld AB, Parodi K. Time-of-flight spectrometry of ultra-short, polyenergetic proton bunches. Rev Sci Instrum 2018; 89:123302. [PMID: 30599609 DOI: 10.1063/1.5052059] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 11/26/2018] [Indexed: 06/09/2023]
Abstract
A common approach for spectrum determination of polyenergetic proton bunches from laser-ion acceleration experiments is based on the time-of-flight (TOF) method. However, spectra obtained using this method are typically given in relative units or are estimated based on some prior assumptions on the energy distribution of the accelerated ions. In this work, we present a new approach using the TOF method that allows for an absolute energy spectrum reconstruction from a current signal acquired with a sub-nanosecond fast and 10 µm thin silicon detector. The reconstruction is based on solving a linear least-squares problem, taking into account the response function of the detection system. The general principle of signal generation and spectrum reconstruction by setting up an appropriate system response matrix is presented. Proof-of-principle experiments at a 12 MV Tandem accelerator using different nanosecond-short (quasi-)monoenergetic and polyenergetic proton bunches at energies up to 20 MeV were successfully performed. Within the experimental uncertainties of 2.4% and 12.1% for energy and particle number, respectively, reconstructed energy distributions were found in excellent agreement with the spectra calculated using Monte Carlo simulations and measured by a magnetic spectrometer. This TOF method can hence be used for absolute online spectrometry of laser-accelerated particle bunches.
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Affiliation(s)
- Matthias Würl
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - Franz S Englbrecht
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - Sebastian Lehrack
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - Chiara Gianoli
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - Florian H Lindner
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - Thomas F Rösch
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - Daniel Haffa
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - Francesco Olivari
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - Marco Petasecca
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Michael L F Lerch
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Alexandre Pogossov
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Linh T Tran
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Walter Assmann
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - Jörg Schreiber
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - Anatoly B Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Katia Parodi
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
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Abstract
Silicon-on-insulator (SOI) microdosimeters offer a promising method for routine quality assurance (QA) for hadron therapy due to their ease of operation and high spatial resolution. However, one complication which has been shown previously is that the traditional use of the mean chord length, [Formula: see text], calculated using Cauchy's formula, for SOI devices in clinical carbon ion fields is not appropriate due to the strong directionality of the radiation field. In a previous study, we demonstrated that the mean path length, [Formula: see text], which is the mean path of charged particles in the sensitive volume (SV), is a more appropriate method to obtain microdosimetric quantities and biological relevant values, namely the relative biological effectiveness (RBE) by means of the microdosimetric kinetic model. The previous work, which was limited to mono-energetic [Formula: see text] ion beams typical of heavy ion therapy (HIT), is extended here to investigate the [Formula: see text] in a pristine proton beam as well as for spread out Bragg peaks (SOBP) for both proton and carbon ion clinical beams. In addition, the angular dependence of the SOI device for a number of different SV designs is also investigated to quantify the effects which the alignment has on the [Formula: see text]. It is demonstrated that the [Formula: see text] can be accurately estimated along the depth of a pristine or SOBP using the energy deposition spectra for both proton and [Formula: see text] ion beams. This observation allows a quick and accurate estimation of the [Formula: see text] for experimental use.
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Affiliation(s)
- D Bolst
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
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Tran LT, Chartier L, Bolst D, Davis J, Prokopovich DA, Pogossov A, Guatelli S, Reinhard MI, Petasecca M, Lerch ML, Matsufuji N, Povoli M, Summanwar A, Kok A, Jackson M, Rosenfeld AB. In-field and out-of-file application in 12C ion therapy using fully 3D silicon microdosimeters. RADIAT MEAS 2018. [DOI: 10.1016/j.radmeas.2018.06.015] [Citation(s) in RCA: 12] [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] [Indexed: 11/15/2022]
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Chartier L, Tran LT, Bolst D, Guatelli S, Pogossov A, Prokopovich DA, Reinhard MI, Perevertaylo V, Anderson S, Beltran C, Matsufuji N, Jackson M, Rosenfeld AB. MICRODOSIMETRIC APPLICATIONS IN PROTON AND HEAVY ION THERAPY USING SILICON MICRODOSIMETERS. Radiat Prot Dosimetry 2018; 180:365-371. [PMID: 29069515 DOI: 10.1093/rpd/ncx226] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Indexed: 06/07/2023]
Abstract
Using the CMRP 'bridge' μ+ probe, microdosimetric measurements were undertaken out-of-field using a therapeutic scanning proton pencil beam and in-field using a 12C ion therapy field. These measurements were undertaken at Mayo Clinic, Rochester, USA and at HIMAC, Chiba, Japan, respectively. For a typical proton field used in the treatment of deep-seated tumors, we observed dose-equivalent values ranging from 0.62 to 0.99 mSv/Gy at locations downstream of the distal edge. Lateral measurements at depths close to the entrance and along the SOBP plateau were found to reach maximum values of 3.1 mSv/Gy and 5.3 mSv/Gy at 10 mm from the field edge, respectively, and decreased to ~0.04 mSv/Gy 120 mm from the field edge. The ability to measure the dose-equivalent with high spatial resolution is particularly relevant to healthy tissue dose calculations in hadron therapy treatments. We have also shown qualitatively and quantitively the effects critical organ motion would have in treatment using microdosimetric spectra. Large differences in spectra and RBE10 were observed for treatments where miscalculations of 12C ion range would result in critical structures being irradiated, showing the importance of motion management.
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Affiliation(s)
- L Chartier
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - L T Tran
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - D Bolst
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - S Guatelli
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - A Pogossov
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
| | - D A Prokopovich
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
- Ionising Radiation, Nuclear Stewardship Platform, NSTLI, ANSTO, Lucas Heights, NSW, Australia
| | - M I Reinhard
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
- Ionising Radiation, Nuclear Stewardship Platform, NSTLI, ANSTO, Lucas Heights, NSW, Australia
| | | | - S Anderson
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN, USA
| | - C Beltran
- Department of Radiation Oncology, Mayo Clinic, Rochester, MN, USA
| | - N Matsufuji
- National Institute for Quantum and Radiological Science and Technology, Japan
| | - M Jackson
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
- School of Medicine, University of New South Wales, Kensington, NSW, Australia
| | - A B Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia
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Tran LT, Bolst D, Guatelli S, Pogossov A, Petasecca M, Lerch MLF, Chartier L, Prokopovich DA, Reinhard MI, Povoli M, Kok A, Perevertaylo VL, Matsufuji N, Kanai T, Jackson M, Rosenfeld AB. The relative biological effectiveness for carbon, nitrogen, and oxygen ion beams using passive and scanning techniques evaluated with fully 3D silicon microdosimeters. Med Phys 2018; 45:2299-2308. [DOI: 10.1002/mp.12874] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 03/07/2018] [Accepted: 03/07/2018] [Indexed: 11/12/2022] Open
Affiliation(s)
- Linh T. Tran
- Centre for Medical Radiation Physics; University of Wollongong; Wollongong NSW 2522 Australia
| | - David Bolst
- Centre for Medical Radiation Physics; University of Wollongong; Wollongong NSW 2522 Australia
| | - Susanna Guatelli
- Centre for Medical Radiation Physics; University of Wollongong; Wollongong NSW 2522 Australia
| | - Alex Pogossov
- Centre for Medical Radiation Physics; University of Wollongong; Wollongong NSW 2522 Australia
| | - Marco Petasecca
- Centre for Medical Radiation Physics; University of Wollongong; Wollongong NSW 2522 Australia
| | - Michael L. F. Lerch
- Centre for Medical Radiation Physics; University of Wollongong; Wollongong NSW 2522 Australia
| | - Lachlan Chartier
- NSTLI Nuclear Stewardship Platform; Australian Nuclear Science and Technology Organisation; Lucas Heights NSW 2234 Australia
| | - Dale A. Prokopovich
- NSTLI Nuclear Stewardship Platform; Australian Nuclear Science and Technology Organisation; Lucas Heights NSW 2234 Australia
| | - Mark I. Reinhard
- NSTLI Nuclear Stewardship Platform; Australian Nuclear Science and Technology Organisation; Lucas Heights NSW 2234 Australia
| | | | | | | | - Naruhiro Matsufuji
- National Institutes for Quantum and Radiological Science and Technology; Chiba Japan
| | | | | | - Anatoly B. Rosenfeld
- Centre for Medical Radiation Physics; University of Wollongong; Wollongong NSW 2522 Australia
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Bolst D, Tran LT, Chartier L, Prokopovich DA, Pogossov A, Guatelli S, Reinhard MI, Petasecca M, Lerch ML, Matsufuji N, Perevertaylo VL, Fleta C, Pellegrini G, Jackson M, Rosenfeld AB. RBE study using solid state microdosimetry in heavy ion therapy. RADIAT MEAS 2017. [DOI: 10.1016/j.radmeas.2017.02.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Anderson SE, Furutani KM, Tran LT, Chartier L, Petasecca M, Lerch M, Prokopovich DA, Reinhard M, Perevertaylo VL, Rosenfeld AB, Herman MG, Beltran C. Microdosimetric measurements of a clinical proton beam with micrometer-sized solid-state detector. Med Phys 2017; 44:6029-6037. [DOI: 10.1002/mp.12583] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 08/09/2017] [Accepted: 08/18/2017] [Indexed: 11/08/2022] Open
Affiliation(s)
- Sarah E. Anderson
- Department of Radiation Oncology; Mayo Clinic; Rochester MN 55902 USA
| | - Keith M. Furutani
- Department of Radiation Oncology; Mayo Clinic; Rochester MN 55902 USA
| | - Linh T. Tran
- Centre for Medical Radiation Physics; University of Wollongong; Wollongong NSW 2522 Australia
| | - Lachlan Chartier
- Centre for Medical Radiation Physics; University of Wollongong; Wollongong NSW 2522 Australia
| | - Marco Petasecca
- Centre for Medical Radiation Physics; University of Wollongong; Wollongong NSW 2522 Australia
| | - Michael Lerch
- Centre for Medical Radiation Physics; University of Wollongong; Wollongong NSW 2522 Australia
| | - Dale A. Prokopovich
- Institute of Materials Engineering; Australian Nuclear Science and Technology Organisation; Lucas Heights NSW 2234 Australia
| | - Mark Reinhard
- Institute of Materials Engineering; Australian Nuclear Science and Technology Organisation; Lucas Heights NSW 2234 Australia
| | | | - Anatoly B. Rosenfeld
- Centre for Medical Radiation Physics; University of Wollongong; Wollongong NSW 2522 Australia
| | - Michael G. Herman
- Department of Radiation Oncology; Mayo Clinic; Rochester MN 55902 USA
| | - Chris Beltran
- Department of Radiation Oncology; Mayo Clinic; Rochester MN 55902 USA
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Tran LT, Chartier L, Bolst D, Pogossov A, Guatelli S, Petasecca M, Lerch MLF, Prokopovich DA, Reinhard MI, Clasie B, Depauw N, Kooy H, Flanz JB, McNamara A, Paganetti H, Beltran C, Furutani K, Perevertaylo VL, Jackson M, Rosenfeld AB. Characterization of proton pencil beam scanning and passive beam using a high spatial resolution solid‐state microdosimeter. Med Phys 2017; 44:6085-6095. [DOI: 10.1002/mp.12563] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 07/31/2017] [Accepted: 08/25/2017] [Indexed: 11/08/2022] Open
Affiliation(s)
- Linh T. Tran
- Centre for Medical Radiation Physics University of Wollongong Wollongong Australia
| | - Lachlan Chartier
- Centre for Medical Radiation Physics University of Wollongong Wollongong Australia
| | - David Bolst
- Centre for Medical Radiation Physics University of Wollongong Wollongong Australia
| | - Alex Pogossov
- Centre for Medical Radiation Physics University of Wollongong Wollongong Australia
| | - Susanna Guatelli
- Centre for Medical Radiation Physics University of Wollongong Wollongong Australia
| | - Marco Petasecca
- Centre for Medical Radiation Physics University of Wollongong Wollongong Australia
| | - Michael L. F. Lerch
- Centre for Medical Radiation Physics University of Wollongong Wollongong Australia
| | - Dale A. Prokopovich
- Australian Nuclear Science and Technology Organisation Lucas Heights Australia
| | - Mark I. Reinhard
- Australian Nuclear Science and Technology Organisation Lucas Heights Australia
| | - Benjamin Clasie
- Department of Radiation Oncology Massachusetts General Hospital & Harvard Medical School Boston MA USA
| | - Nicolas Depauw
- Department of Radiation Oncology Massachusetts General Hospital & Harvard Medical School Boston MA USA
| | - Hanne Kooy
- Department of Radiation Oncology Massachusetts General Hospital & Harvard Medical School Boston MA USA
| | - Jacob B. Flanz
- Department of Radiation Oncology Massachusetts General Hospital & Harvard Medical School Boston MA USA
| | - Aimee McNamara
- Department of Radiation Oncology Massachusetts General Hospital & Harvard Medical School Boston MA USA
| | - Harald Paganetti
- Department of Radiation Oncology Massachusetts General Hospital & Harvard Medical School Boston MA USA
| | | | | | | | - Michael Jackson
- Radiation Oncology Department Prince of Wales Hospital Randwick NSW 2031 Australia
| | - Anatoly B. Rosenfeld
- Centre for Medical Radiation Physics University of Wollongong Wollongong Australia
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Guatelli S, Vohradsky J, Davis J, Tran LT, Rosenfeld A. Abstract ID: 28 Evaluation of silicon and diamond based microdosimetry for boron neutron capture therapy quality assurance. Phys Med 2017. [DOI: 10.1016/j.ejmp.2017.09.011] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Bolst D, Guatelli S, Tran LT, Chartier L, Lerch MLF, Matsufuji N, Rosenfeld AB. Correction factors to convert microdosimetry measurements in silicon to tissue in 12C ion therapy. Phys Med Biol 2017; 62:2055-2069. [DOI: 10.1088/1361-6560/aa5de5] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Tran LT, Roos A, Fouche JP, Koen N, Woods RP, Zar HJ, Narr KL, Stein DJ, Donald KA. White Matter Microstructural Integrity and Neurobehavioral Outcome of HIV-Exposed Uninfected Neonates. Medicine (Baltimore) 2016; 95:e2577. [PMID: 26825902 PMCID: PMC5291572 DOI: 10.1097/md.0000000000002577] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
The successful implementation of prevention programs for mother-to-child human immunodeficiency virus (HIV) transmission has dramatically reduced the prevalence of infants infected with HIV while increasing that of HIV-exposed uninfected (HEU) children. Neuropsychological assessments indicate that HEU children may exhibit differences in neurodevelopment compared to unexposed children (HUU). Pathological mechanisms leading to such neurodevelopmental delays are not clear. In this observational birth cohort study we explored the integrity of regional white matter microstructure in HEU infants, shortly after birth. Microstructural changes in white matter associated with prenatal HIV exposure were evaluated in HEU infants (n = 15) and matched controls (n = 22) using diffusion tensor imaging and tract-based spatial statistics. Additionally, diffusion values were extracted and compared for white matter tracts of interest, and associations with clinical outcomes from the Dubowitz neonatal neurobehavioral tool were investigated. Higher fractional anisotropy in the middle cerebellar peduncles of HEU compared to HUU neonates was found after correction for age and gender. Scores on the Dubowitz abnormal neurological signs subscale were positively correlated with FA (r = 0.58, P = 0.038) in the left uncinate fasciculus in HEU infants. This is the first study to present data suggesting that prenatal HIV exposure without infection is associated with altered white matter microstructural integrity in the neonatal period. Longitudinal studies of HEU infants as their brains mature are necessary to understand further the significance of prenatal HIV and antiretroviral treatment exposure on white matter integrity and neurodevelopmental outcomes.
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Affiliation(s)
- Linh T Tran
- From the Division of Developmental Paediatrics, Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital and University of Cape Town (LTT, KAD); SU/UCT MRC Unit on Anxiety & Stress Disorders, Stellenbosch University (AR); Department of Psychiatry and Mental Health, University of Cape Town (J-PF); Department of Psychiatry, Stellenbosch University (J-PF); Department of Psychiatry and Mental Health, MRC Unit on Anxiety & Stress Disorders, University of Cape Town, Cape Town, South Africa (NK, DJS); Department of Neurology, University of California, Los Angeles, CA (RPW, KLN); and Department of Paediatrics and Child Health and MRC Unit on Child & Adolescent Health, Red Cross War Memorial Children's Hospital and University of Cape Town, Cape Town, South Africa (HJZ)
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Tran LT, Prokopovich DA, Lerch ML, Petasecca M, Siegele R, Reinhard MI, Perevertaylo V, Rosenfeld AB. Development of a large-area silicon α-particle detector. Appl Radiat Isot 2014; 92:96-101. [DOI: 10.1016/j.apradiso.2014.06.009] [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] [Received: 02/17/2014] [Revised: 05/12/2014] [Accepted: 05/27/2014] [Indexed: 10/25/2022]
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Tran LT, Worner SP, Hale RJ, Teulon DAJ. Estimating development rate and thermal requirements of Bactericera cockerelli (Hemiptera: Triozidae) reared on potato and tomato by using linear and nonlinear models. Environ Entomol 2012; 41:1190-1198. [PMID: 23068177 DOI: 10.1603/en12124] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The temperature-dependent development of tomato psyllid (also called potato psyllid), Bactericera cockerelli (Sulc), was studied in the laboratory at seven constant temperatures (8, 10, 15, 20, 23, 27, and 31°C), 50-60% RH, and a photoperiod of 16:8 (L:D) h on leaves of whole potato (Solanum tuberosum L.) and tomato (Solanum lycopersicum L.) plants. Developmental time in days for immature stages and total development (egg to adult) on both host species were inversely proportional to temperature between 8 and 27°C but increased at 31°C. One linear and two nonlinear models were fitted to the data. The lower developmental thresholds, calculated using the linear model for egg, total nymph, and total development (from oviposition to adult emergence) were 7.9, 4.2, and 7.1°C (reared on potato) and 7.2, 5.3, and 7.5°C (reared on tomato), respectively. The thermal constant (K) for total development was 358 (reared on potato), and 368 (reared on tomato) degree-days (DD). Two nonlinear models, Briere and Lactin, fit the data well as measured by goodness-of-fit criteria, the residual sum of square (RSS) and Akaike information criterion (AIC). Temperature threshold parameters for these nonlinear models (T(0), T(opt), and T(max)) were estimated for eggs, total nymphal stages, and total development time (egg to adult). The Briere model is highly recommended for the description of temperature-dependent development of tomato psyllid. Results from this study will provide basic information on the biology of tomato psyllid and have potential for the development of predictive models of the seasonal progress of this invasive pest.
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Affiliation(s)
- L T Tran
- Bio-Protection Research Centre, PO Box 84, Lincoln University 7674, Christchurch, New Zealand.
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Tran LT, MacLeod KM, McNeill JH. Endothelin-1 modulates angiotensin II in the development of hypertension in fructose-fed rats. Mol Cell Biochem 2009; 325:89-97. [PMID: 19139972 DOI: 10.1007/s11010-008-0023-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Accepted: 12/30/2008] [Indexed: 02/07/2023]
Abstract
Two of the most potent vasoconstrictors, endothelin-1 (ET-1) and angiotensin II (Ang II), are upregulated in fructose hypertensive rats. It is unknown whether an interrelationship exists between these peptides that may contribute to the development of fructose-induced hypertension. The objective of this study was to investigate the existence of an interaction between the endothelin and renin angiotensin systems that may play a role in the development of fructose-induced hypertension. High fructose feeding and treatment with either bosentan, a dual endothelin receptor antagonist, or with L-158,809, an angiotensin type 1 receptor antagonist, were initiated simultaneously in male Wistar rats. Systolic blood pressure, fasted plasma parameters, insulin sensitivity, plasma Ang II, and vascular ET-1-immunoreactivity were determined following 6 weeks of high fructose feeding. Rats fed with a high fructose diet exhibited insulin resistance, hyperinsulinemia, hypertriglyceridemia, hypertension, and elevated plasma Ang II. Treatment with either bosentan or L-158,809 significantly attenuated the rise in blood pressure with no effect on insulin levels or insulin sensitivity in fructose-fed rats. Bosentan treatment significantly reduced plasma Ang II levels, while L-158,809 treatment significantly increased vascular ET-1-immunoreactivity in fructose-fed rats. Thus, treatment with the endothelin receptor antagonist prevented the development of fructose-induced hypertension and decreased plasma Ang II levels. These data suggest that ET-1 contributes to the development of fructose-induced hypertension through modulation of Ang II levels.
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Affiliation(s)
- L T Tran
- Division of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, University of British Columbia, 2146 East Mall, Vancouver, BC, V6T 1Z3, Canada
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Abstract
The purpose of this study was to determine whether decreased day lengths affect reproduction or the immune system in inbred mice. Irrespective of a nocturnal pineal melatonin rise, the signal for day length information, body and testis weights were the same in various strains 8 weeks after transfer from long to short days (16 to 8 h of light/day) compared to mice that remained in long days. Serum testosterone was unaffected by the photoperiod shift. The second goal was to determine whether the shift from long to short days influenced lymphocyte populations in spleen or blood, as well as innate and cell-mediated immune cell functions in C3H/HeN mice, an inbred strain with a robust melatonin rhythm. By flow cytometry, a stable percentage and number of B cells, T cells, and natural killer cells were identified in spleen from mice in both long and short days during the day and night. This complement of immunophenotypes in spleen suggests that equivalent functional capabilities persist in secondary lymphoid tissue of mice irrespective of day length. This was supported by findings that cytolytic activity by splenic natural killer cells (innate immunity) and antigen-induced T cell-dependent B cell antibody production (adaptive immunity) were similar in mice in long and short days. In blood, cell numbers but not helper T cell subset percentages (i.e., naive, memory, cytotoxic, or activated) were augmented in mice in short compared to long days, a consequence of increased circulating B cells. Day length differences in certain immunophenotypes in circulation may forecast photoperiod-mediated alterations in responsiveness to pathogens that are associated with a change in season. At night, the reduced proportion of cytotoxic T cells (long and short days), as well as increases in the percentage of activated T cells (long days), B cells (short days), and NK cell activity (long and short days) relative to daytime, suggests that surveillance and function by select immunophenotypes may adapt to circadian transitions even in highly inbred species. Thus, inbred mice retain capabilities for photoperiod to influence trait-specific aspects of immune cell but not reproductive function.
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Affiliation(s)
- S M Yellon
- Center for Perinatal Biology, Department of Physiology, Loma Linda University School of Medicine, CA 92350, USA.
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Sajjan US, Tran LT, Sole N, Rovaldi C, Akiyama A, Friden PM, Forstner JF, Rothstein DM. P-113D, an antimicrobial peptide active against Pseudomonas aeruginosa, retains activity in the presence of sputum from cystic fibrosis patients. Antimicrob Agents Chemother 2001; 45:3437-44. [PMID: 11709321 PMCID: PMC90850 DOI: 10.1128/aac.45.12.3437-3444.2001] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [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: 11/20/2022] Open
Abstract
Antimicrobial peptides are a source of novel agents that could be useful for treatment of the chronic lung infections that afflict cystic fibrosis (CF) patients. Efficacy depends on antimicrobial activity against the major pathogens of CF patients, Pseudomonas aeruginosa, Staphylococcus aureus, and Haemophilus influenzae, in the environment of the CF patient's airway. We describe the in vitro efficacies of derivatives of histatins, which are histidine-rich peptides produced by the salivary glands of humans and higher primates. P-113, a peptide containing 12 of the 24 amino acid residues of the parent molecule, histatin 5, retained full antibacterial activity and had a good spectrum of activity in vitro against the prominent pathogens of CF patients. However, P-113 was not active in the presence of purulent sputum from CF patients. In contrast, P-113D, the mirror-image peptide with the amino acid residues in the D configuration, was stable in sputum, was as active as P-113 against pathogens of CF patients in the absence of sputum and retained significant activity in the presence of sputum from CF patients. Recombinant human DNase, which effectively liquefies sputum, enhanced the activity of P-113D in undiluted sputum against both exogenous (added) bacteria and endogenous bacteria. Because of its properties, P-113D shows potential as an inhalant in chronic suppressive therapy for CF patients.
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Affiliation(s)
- U S Sajjan
- The Hospital for Sick Children, Toronto, Ontario, Canada
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Prendergast BJ, Yellon SM, Tran LT, Nelson RJ. Photoperiod modulates the inhibitory effect of in vitro melatonin on lymphocyte proliferation in female Siberian hamsters. J Biol Rhythms 2001; 16:224-33. [PMID: 11407782 DOI: 10.1177/074873040101600305] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In Siberian hamsters (Phodopus sungorus), short days suppress reproductive function and lymphocyte proliferation. To determine whether melatonin influences cell-mediated immunity through a direct action on lymphocyte proliferation, in vitro responsiveness to mitogens and melatonin was assessed in systemic and splenic lymphocytes from adult female Siberian hamsters housed in either long or short days for 13 weeks. Short days provoked reproductive regression and reduced lymphocyte proliferation. Physiological concentrations of melatonin (50 pg/ml) inhibited in vitro proliferation of circulating lymphocytes, whereas higher concentrations (> or = 500 pg/ml) were required to inhibit proliferation of splenic lymphocytes. Immunomodulatory effects of melatonin were restricted to lymphocytes from long-day hamsters-in vitro melatonin had no effect on circulating or splenic lymphocytes from females in short days. Responsiveness to melatonin in short-day lymphocytes may be restrained by the already expanded nightly pattern of melatonin secretion in short days. These data support the hypothesis that melatonin acts directly on lymphocytes from long-day hamsters to suppress blastogenesis.
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Affiliation(s)
- B J Prendergast
- Department of Psychology and Neuroscience, The Ohio State University, Columbus 43210, USA.
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Rothstein DM, Spacciapoli P, Tran LT, Xu T, Roberts FD, Dalla Serra M, Buxton DK, Oppenheim FG, Friden P. Anticandida activity is retained in P-113, a 12-amino-acid fragment of histatin 5. Antimicrob Agents Chemother 2001; 45:1367-73. [PMID: 11302797 PMCID: PMC90475 DOI: 10.1128/aac.45.5.1367-1373.2001] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Through the analysis of a series of 25 peptides composed of various portions of the histatin 5 sequence, we have identified P-113, a 12-amino-acid fragment of histatin 5, as the smallest fragment that retains anticandidal activity comparable to that of the parent compound. Amidation of the P-113 C terminus increased the anticandidal activity of P-113 approximately twofold. The three histidine residues could be exchanged for three hydrophobic residues, with the fragment retaining anticandidal activity. However, the change of two or more of the five basic (lysine and arginine) residues to uncharged residues resulted in a substantial loss of anticandidal activity. A synthetic D-amino-acid analogue, P-113D, was as active against Candida albicans as the L-amino-acid form. In vitro MIC tests in low-ionic-strength medium showed that P-113 has potent activity against Candida albicans, Candida glabrata, Candida parapsilosis, and Candida tropicalis. These results identify P-113 as a potential antimicrobial agent in the treatment of oral candidiasis.
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Crittenden RG, Morris LF, Harvey ML, Tran LT, Mitchell HL, Playne MJ. Selection of a Bifidobacterium strain to complement resistant starch in a synbiotic yoghurt. J Appl Microbiol 2001; 90:268-78. [PMID: 11168730 DOI: 10.1046/j.1365-2672.2001.01240.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.5] [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: 11/20/2022]
Abstract
AIMS To employ an in vitro screening regime to select a probiotic Bifidobacterium strain to complement resistant starch (Hi-maizetrade mark) in a synbiotic yoghurt. METHODS AND RESULTS Of 40 Bifidobacterium isolates examined, only B. lactis Laftitrade mark B94 possessed all of the required characteristics. This isolate hydrolysed Hi-maizetrade mark, survived well in conditions simulating passage through the gastrointestinal tract and possessed technological properties suitable for yoghurt manufacture. It grew well at temperatures up to 45 degrees C, and grew to a high cell yield in an industrial growth medium. In addition to resistant starch, the organism was able to utilize a range of prebiotics including inulin, and fructo-, galacto-, soybean- and xylo-oligosaccharides. Pulse field gel electrophoresis of restriction enzyme cut chromosomal DNA revealed that B. lactis Laftitrade mark B94 was very closely related to the B. lactis Type Strain (DSM 10140), and to the commercial strains B. lactis Bb-12 and B. lactis DS 920. However, B. lactis Laftitrade mark B94 was the only one of these isolates that could hydrolyse Hi-maizetrade mark. This phenotypic difference did not appear to be due to the presence of plasmid encoded amylase. Bifidobacterium lactis Laftitrade mark B94 survived without substantial loss of viability in synbiotic yoghurt containing Hi-maizetrade mark during storage at 4 degrees C for six weeks. CONCLUSION Bifidobacterium lactis Laftitrade mark B94 is a promising new yoghurt culture that warrants further investigation to assess its probiotic potential. SIGNIFICANCE AND IMPACT OF THE STUDY In vitro screening procedures can be used to integrate complementary probiotic and prebiotic ingredients for new synbiotic functional food products.
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Leung P, Tran LT, Fast AW. A logistic regression of risk factors for disease occurrence on Asian shrimp farms. Dis Aquat Organ 2000; 41:65-76. [PMID: 10907140 DOI: 10.3354/dao041065] [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: 05/23/2023]
Abstract
Serious shrimp-disease outbreaks have reduced shrimp production and slowed industry growth since 1991. This paper tests factors such as farm sitting and design, and farm-management practices for relationships with disease occurrence. Logistic regression is used to analyze farm-level data from 3951 shrimp farms in 13 Asian countries. Disease occurrence is modeled as a 0-1 variable where 1 = disease loss of > or = 20% to any 1 crop, and 0 = losses of < 20%. Logistic regression is performed for each of 3 levels of shrimp culture intensity, i.e. extensive, semi-intensive, and intensive. Attempts to apply logistic regression models to each country were not successful due to insufficient data for most countries. Factors affecting disease occurrences were quite different for different farming intensities. Farms that had larger pond production areas, with larger number of farms discharging effluent into their water supply canals, and removed silt had greater disease occurrence. On the other hand, farms that practiced polyculture and took water from the sea through a canal had lower disease occurrence.
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Affiliation(s)
- P Leung
- Department of Biosystems Engineering, University of Hawaii at Manoa, Honolulu 96822, USA.
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Abstract
Candida infections involve multiple risk factors. Among the independent risk factors identified, the degree of colonization of Candida spp. allows the prediction of subsequent severe candidosis in surgical patients. The aim of this study was to assess among 13 selected variables, those that would best predict the perioperative variation of the colonization index (CI) of Candida spp. in cardiovascular surgical patients. The colonization index took into account the number of sites colonized and the density of growth. The results showed that 56.8% of our patients were colonized perioperatively. A total of 116 isolates were identified and Candida albicans accounted for 76.7% of the strains. Among the patients who developed post-surgical Candida infections, 57.1% had an increase of the CI early after the operation. By univariate analysis, three factors were significantly associated with an increase of the CI in patients after surgery; sex (female), the duration of central intravascular catheterization and the length of stay in the surgical intensive care unit (SICU). Epidemiological data could help predict those patients who are at risk of developing Candida infections.
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Affiliation(s)
- L T Tran
- Montreal Heart Institute, Quebec, Canada
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Rau SE, Bend JR, Arnold MO, Tran LT, Spence JD, Bailey DG. Grapefruit juice-terfenadine single-dose interaction: magnitude, mechanism, and relevance. Clin Pharmacol Ther 1997; 61:401-9. [PMID: 9129557 DOI: 10.1016/s0009-9236(97)90190-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [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: 02/04/2023]
Abstract
OBJECTIVE To investigate the single dose-response effects of grapefruit juice on terfenadine disposition and electrocardiographic measurements. METHODS Twelve healthy males received 250 ml water or regular- or double-strength grapefruit juice with 60 mg terfenadine in a randomized crossover trial. Plasma concentrations of the cardiotoxic agent terfenadine and the active antihistaminic metabolite terfenadine carboxylate were determined over 8 hours. The QTc interval was monitored. RESULTS Terfenadine concentrations were measurable (> 1 ng/ml) in 27 (20%; p < 0.001) and 39 (30%; p < 0.001) samples from individuals treated with regular- and double-strength grapefruit juice, respectively, compared to only four (3%) samples with water. Terfenadine plasma peak drug concentration (Cmax) was also higher. Terfenadine carboxylate area under the plasma drug concentration-time curve (AUC), Cmax, and time to reach Cmax (tmax) were increased by both strengths of juice. However, terfenadine carboxylate apparent elimination half-life (t1/2) was not altered. The magnitude of the interaction of terfenadine carboxylate AUC and Cmax ranged severalfold and correlated among individuals for regular-strength (r2 = 0.87; p < 0.0001) and double-strength (r2 = 0.78; p < 0.0001) grapefruit juice. No differences in the pharmacokinetics of terfenadine and terfenadine carboxylate were observed between the two strengths of grapefruit juice. QTc interval was not altered. CONCLUSIONS A normal amount of regular-strength grapefruit juice produced maximum single-dose effects on terfenadine and carboxylic acid metabolite pharmacokinetics. The mechanism likely involved reduced presystemic drug elimination by inhibition of more than one metabolic pathway. The extent of the interaction was not sufficient to produce electrocardiographic changes. However, the pharmacokinetic effects were highly variable among individuals. This study further enhances the awareness of the potential for a serious interaction between grapefruit juice and terfenadine.
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Affiliation(s)
- S E Rau
- Department of Pharmacology and Toxicology, University of Western Ontario, London, Canada
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