1
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Daneshnia F, Floyd DJ, Ryan AP, Ghahfarokhy PM, Ebadati A, Jusuf S, Munoz J, Jeffries NE, Elizabeth Yvanovich E, Apostolopoulou A, Perry AM, Lass-Flörl C, Birinci A, Hilmioğlu-Polat S, Ilkit M, Butler G, Nobile CJ, Arastehfar A, Mansour MK. Evaluation of outbreak persistence caused by multidrug-resistant and echinocandin-resistant Candida parapsilosis using multidimensional experimental and epidemiological approaches. Emerg Microbes Infect 2024; 13:2322655. [PMID: 38380673 PMCID: PMC10916928 DOI: 10.1080/22221751.2024.2322655] [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: 01/09/2024] [Accepted: 02/20/2024] [Indexed: 02/22/2024]
Abstract
Candida parapsilosis is known to cause severe and persistent outbreaks in clinical settings. Patients infected with multidrug-resistant C. parapsilosis (MDR Cp) isolates were identified in a large Turkish hospital from 2017-2020. We subsequently identified three additional patients infected with MDR Cp isolates in 2022 from the same hospital and two echinocandin-resistant (ECR) isolates from a single patient in another hospital. The increasing number of MDR and ECR isolates contradicts the general principle that the severe fitness cost associated with these phenotypes could prevent their dominance in clinical settings. Here, we employed a multidimensional approach to systematically assess the fitness costs of MDR and ECR C. parapsilosis isolates. Whole-genome sequencing revealed a novel MDR genotype infecting two patients in 2022. Despite severe in vitro defects, the levels and tolerances of the biofilms of our ECR and MDR isolates were generally comparable to those of susceptible wild-type isolates. Surprisingly, the MDR and ECR isolates showed major alterations in their cell wall components, and some of the MDR isolates consistently displayed increased tolerance to the fungicidal activities of primary human neutrophils and were more immunoevasive during exposure to primary human macrophages. Our systemic infection mouse model showed that MDR and ECR C. parapsilosis isolates had comparable fungal burden in most organs relative to susceptible isolates. Overall, we observed a notable increase in the genotypic diversity and frequency of MDR isolates and identified MDR and ECR isolates potentially capable of causing persistent outbreaks in the future.
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Affiliation(s)
- Farnaz Daneshnia
- Division of Infectious Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Institute of Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Amsterdam, The Netherlands
| | - Daniel J. Floyd
- Division of Infectious Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Adam P. Ryan
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Pegah Mosharaf Ghahfarokhy
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California – Merced, Merced, CA, USA
- Health Sciences Research Institute, University of California – Merced, Merced, CA, USA
| | - Arefeh Ebadati
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California – Merced, Merced, CA, USA
| | - Sebastian Jusuf
- Division of Infectious Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Julieta Munoz
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California – Merced, Merced, CA, USA
| | | | | | - Anna Apostolopoulou
- Division of Infectious Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Austin M. Perry
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California – Merced, Merced, CA, USA
| | - Cornelia Lass-Flörl
- Medical University Innsbruck, Institute of Hygiene and Medical Microbiology, Innsbruck, Austria
| | - Asuman Birinci
- Department of Medical Microbiology, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Türkiye
| | | | - Macit Ilkit
- Division of Mycology, Faculty of Medicine, Çukurova University, Adana, Türkiye
| | - Geraldine Butler
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Clarissa J. Nobile
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California – Merced, Merced, CA, USA
- Health Sciences Research Institute, University of California – Merced, Merced, CA, USA
| | - Amir Arastehfar
- Division of Infectious Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Michael K. Mansour
- Division of Infectious Diseases, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
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Li C, Tao L, Guan G, Guan Z, Perry AM, Hu T, Bing J, Xu M, Nobile CJ, Huang G. Atmospheric humidity regulates same-sex mating in Candida albicans through the trehalose and osmotic signaling pathways. Sci China Life Sci 2023; 66:1915-1929. [PMID: 37118508 PMCID: PMC10631464 DOI: 10.1007/s11427-023-2309-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 03/01/2023] [Indexed: 04/30/2023]
Abstract
Sexual reproduction is prevalent in eukaryotic organisms and plays a critical role in the evolution of new traits and in the generation of genetic diversity. Environmental factors often have a direct impact on the occurrence and frequency of sexual reproduction in fungi. The regulatory effects of atmospheric relative humidity (RH) on sexual reproduction and pathogenesis in plant fungal pathogens and in soil fungi have been extensively investigated. However, the knowledge of how RH regulates the lifecycles of human fungal pathogens is limited. In this study, we report that low atmospheric RH promotes the development of mating projections and same-sex (homothallic) mating in the human fungal pathogen Candida albicans. Low RH causes water loss in C. albicans cells, which results in osmotic stress and the generation of intracellular reactive oxygen species (ROS) and trehalose. The water transporting aquaporin Aqy1, and the G-protein coupled receptor Gpr1 function as cell surface sensors of changes in atmospheric humidity. Perturbation of the trehalose metabolic pathway by inactivating trehalose synthase or trehalase promotes same-sex mating in C. albicans by increasing osmotic or ROS stresses, respectively. Intracellular trehalose and ROS signal the Hog1-osmotic and Hsf1-Hsp90 signaling pathways to regulate the mating response. We, therefore, propose that the cell surface sensors Aqy1 and Gpr1, intracellular trehalose and ROS, and the Hog1-osmotic and Hsf1-Hsp90 signaling pathways function coordinately to regulate sexual mating in response to low atmospheric RH conditions in C. albicans.
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Affiliation(s)
- Chao Li
- Department of Infectious Diseases, Huashan Hospital, Shanghai Institute of Infectious Disease and Biosecurity and State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Li Tao
- Department of Infectious Diseases, Huashan Hospital, Shanghai Institute of Infectious Disease and Biosecurity and State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Guobo Guan
- Department of Infectious Diseases, Huashan Hospital, Shanghai Institute of Infectious Disease and Biosecurity and State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zhangyue Guan
- Department of Infectious Diseases, Huashan Hospital, Shanghai Institute of Infectious Disease and Biosecurity and State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Austin M Perry
- Department of Molecular and Cell Biology, University of California, Merced, Merced, CA, 95343, USA
- Quantitative and Systems Biology Graduate Program, University of California, Merced, Merced, CA, 95343, USA
| | - Tianren Hu
- Department of Infectious Diseases, Huashan Hospital, Shanghai Institute of Infectious Disease and Biosecurity and State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Jian Bing
- Department of Infectious Diseases, Huashan Hospital, Shanghai Institute of Infectious Disease and Biosecurity and State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Ming Xu
- Department of Infectious Diseases, Huashan Hospital, Shanghai Institute of Infectious Disease and Biosecurity and State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Clarissa J Nobile
- Department of Molecular and Cell Biology, University of California, Merced, Merced, CA, 95343, USA
- Health Sciences Research Institute, University of California, Merced, Merced, CA, 95343, USA
| | - Guanghua Huang
- Department of Infectious Diseases, Huashan Hospital, Shanghai Institute of Infectious Disease and Biosecurity and State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, 200438, China.
- Shanghai Engineering Research Center of Industrial Microorganisms, Shanghai, 200438, China.
- Shanghai Huashen Institute of Microbes and Infections, Shanghai, 200052, China.
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Daneshnia F, de Almeida Júnior JN, Ilkit M, Lombardi L, Perry AM, Gao M, Nobile CJ, Egger M, Perlin DS, Zhai B, Hohl TM, Gabaldón T, Colombo AL, Hoenigl M, Arastehfar A. Worldwide emergence of fluconazole-resistant Candida parapsilosis: current framework and future research roadmap. Lancet Microbe 2023; 4:e470-e480. [PMID: 37121240 PMCID: PMC10634418 DOI: 10.1016/s2666-5247(23)00067-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/11/2023] [Accepted: 02/15/2023] [Indexed: 05/02/2023]
Abstract
Candida parapsilosis is one of the most commen causes of life-threatening candidaemia, particularly in premature neonates, individuals with cancer of the haematopoietic system, and recipients of organ transplants. Historically, drug-susceptible strains have been linked to clonal outbreaks. However, worldwide studies started since 2018 have reported severe outbreaks among adults caused by fluconazole-resistant strains. Outbreaks caused by fluconazole-resistant strains are associated with high mortality rates and can persist despite strict infection control strategies. The emergence of resistance threatens the efficacy of azoles, which is the most widely used class of antifungals and the only available oral treatment option for candidaemia. The fact that most patients infected with fluconazole-resistant strains are azole-naive underscores the high potential adaptability of fluconazole-resistant strains to diverse hosts, environmental niches, and reservoirs. Another concern is the multidrug-resistant and echinocandin-tolerant C parapsilosis isolates, which emerged in 2020. Raising awareness, establishing effective clinical interventions, and understanding the biology and pathogenesis of fluconazole-resistant C parapsilosis are urgently needed to improve treatment strategies and outcomes.
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Affiliation(s)
- Farnaz Daneshnia
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA; Institute of Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, Netherlands
| | - João N de Almeida Júnior
- Department of Medicine, Division of Infectious Diseases, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil; Clinical Laboratory, Hospital Israelita Albert Einstein, São Paulo, Brazil
| | - Macit Ilkit
- Division of Mycology, Faculty of Medicine, University of Çukurova, Adana, Türkiye
| | - Lisa Lombardi
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Dublin, Ireland
| | - Austin M Perry
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California Merced, Merced, CA, USA; Quantitative and Systems Biology Graduate Program, University of California Merced, Merced, CA, USA
| | - Marilyn Gao
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California Merced, Merced, CA, USA
| | - Clarissa J Nobile
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California Merced, Merced, CA, USA; Health Sciences Research Institute, University of California Merced, Merced, CA, USA
| | - Matthias Egger
- Division of Infectious Diseases, ECMM Excellence Center, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - David S Perlin
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, USA; Department of Medical Sciences, Hackensack School of Medicine, Nutley, NJ, USA; Georgetown University Lombardi Comprehensive Cancer Center, Washington, DC, USA
| | - Bing Zhai
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Tobias M Hohl
- Infectious Disease Service, Department of Medicine and Human Oncology, and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Department of Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Toni Gabaldón
- Life Sciences Programme, Supercomputing Center, Barcelona, Spain; Institute for Research in Biomedicine, Barcelona, Spain; Catalan Institution for Research and Advanced Studies, Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Infecciosas, Barcelona, Spain
| | - Arnaldo Lopes Colombo
- Department of Medicine, Division of Infectious Diseases, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Martin Hoenigl
- Division of Infectious Diseases, ECMM Excellence Center, Department of Internal Medicine, Medical University of Graz, Graz, Austria; Bio TechMed, Graz, Austria; Translational Medical Mycology Research Group, Medical University of Graz, Graz, Austria.
| | - Amir Arastehfar
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA; Department of Medicine, Harvard Medical School, Boston, MA, USA.
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4
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Wooten DJ, Zañudo JGT, Murrugarra D, Perry AM, Dongari-Bagtzoglou A, Laubenbacher R, Nobile CJ, Albert R. Mathematical modeling of the Candida albicans yeast to hyphal transition reveals novel control strategies. PLoS Comput Biol 2021; 17:e1008690. [PMID: 33780439 PMCID: PMC8031856 DOI: 10.1371/journal.pcbi.1008690] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 04/08/2021] [Accepted: 03/17/2021] [Indexed: 01/14/2023] Open
Abstract
Candida albicans, an opportunistic fungal pathogen, is a significant cause of human infections, particularly in immunocompromised individuals. Phenotypic plasticity between two morphological phenotypes, yeast and hyphae, is a key mechanism by which C. albicans can thrive in many microenvironments and cause disease in the host. Understanding the decision points and key driver genes controlling this important transition and how these genes respond to different environmental signals is critical to understanding how C. albicans causes infections in the host. Here we build and analyze a Boolean dynamical model of the C. albicans yeast to hyphal transition, integrating multiple environmental factors and regulatory mechanisms. We validate the model by a systematic comparison to prior experiments, which led to agreement in 17 out of 22 cases. The discrepancies motivate alternative hypotheses that are testable by follow-up experiments. Analysis of this model revealed two time-constrained windows of opportunity that must be met for the complete transition from the yeast to hyphal phenotype, as well as control strategies that can robustly prevent this transition. We experimentally validate two of these control predictions in C. albicans strains lacking the transcription factor UME6 and the histone deacetylase HDA1, respectively. This model will serve as a strong base from which to develop a systems biology understanding of C. albicans morphogenesis.
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Affiliation(s)
- David J. Wooten
- Department of Physics, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Jorge Gómez Tejeda Zañudo
- Eli and Edythe L. Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, United States of America
| | - David Murrugarra
- Department of Mathematics, University of Kentucky, Lexington, Kentucky, United States of America
| | - Austin M. Perry
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California Merced, Merced, California, United States of America
- Quantitative and Systems Biology Graduate Program, University of California Merced, Merced, California, United States of America
| | - Anna Dongari-Bagtzoglou
- Department of Oral Health and Diagnostic Sciences, University of Connecticut Health Center, Farmington, Connecticut, United States of America
| | - Reinhard Laubenbacher
- Department of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Clarissa J. Nobile
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California Merced, Merced, California, United States of America
- Health Sciences Research Institute, University of California Merced, Merced, California, United States of America
| | - Réka Albert
- Department of Physics, Pennsylvania State University, University Park, Pennsylvania, United States of America
- * E-mail:
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5
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Abstract
Biofilms, structured and densely packed communities of microbial cells attached to surfaces, are considered to be the natural growth state for a vast majority of microorganisms. The ability to form biofilms is an important virulence factor for most pathogens, including the opportunistic human fungal pathogen Candida albicans. C. albicans is one of the most prevalent fungal species of the human microbiota that asymptomatically colonizes healthy individuals. However, C. albicans can also cause severe and life-threatening infections when host conditions permit (e.g., through alterations in the host immune system, pH, and resident microbiota). Like many other pathogens, this ability to cause infections depends, in part, on the ability to form biofilms. Once formed, C. albicans biofilms are often resistant to antifungal agents and the host immune response, and can act as reservoirs to maintain persistent infections as well as to seed new infections in a host. The majority of C. albicans clinical isolates are heterozygous (a/α) at the mating type-like (MTL) locus, which defines Candida mating types, and are capable of forming robust biofilms when cultured in vitro. These “conventional” biofilms, formed by MTL-heterozygous (a/α) cells, have been the primary focus of C. albicans biofilm research to date. Recent work in the field, however, has uncovered novel mechanisms through which biofilms are generated by C. albicans cells that are homozygous or hemizygous (a/a, a/Δ, α/α, or α/Δ) at the MTL locus. In these studies, the addition of pheromones of the opposite mating type can induce the formation of specialized “sexual” biofilms, either through the addition of synthetic peptide pheromones to the culture, or in response to co-culturing of cells of the opposite mating types. Although sexual biofilms are generally less robust than conventional biofilms, they could serve as a protective niche to support genetic exchange between mating-competent cells, and thus may represent an adaptive mechanism to increase population diversity in dynamic environments. Although conventional and sexual biofilms appear functionally distinct, both types of biofilms are structurally similar, containing yeast, pseudohyphal, and hyphal cells surrounded by an extracellular matrix. Despite their structural similarities, conventional and sexual biofilms appear to be governed by distinct transcriptional networks and signaling pathways, suggesting that they may be adapted for, and responsive to, distinct environmental conditions. Here we review sexual biofilms and compare and contrast them to conventional biofilms of C. albicans.
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Affiliation(s)
- Austin M. Perry
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, CA 95343, USA; (A.M.P.); (A.D.H.)
- Quantitative and Systems Biology Graduate Program, University of California, Merced, CA 95343, USA
| | - Aaron D. Hernday
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, CA 95343, USA; (A.M.P.); (A.D.H.)
| | - Clarissa J. Nobile
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, CA 95343, USA; (A.M.P.); (A.D.H.)
- Correspondence: ; Tel.: +1-209-228-2427
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6
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Gulati M, Lohse MB, Ennis CL, Gonzalez RE, Perry AM, Bapat P, Arevalo AV, Rodriguez DL, Nobile CJ. In Vitro Culturing and Screening of Candida albicans Biofilms. ACTA ACUST UNITED AC 2018; 50:e60. [PMID: 29995344 DOI: 10.1002/cpmc.60] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Candida albicans is a normal member of the human microbiota that asymptomatically colonizes healthy individuals, however it is also an opportunistic pathogen that can cause severe infections, especially in immunocompromised individuals. The medical impact of C. albicans depends, in part, on its ability to form biofilms, communities of adhered cells encased in an extracellular matrix. Biofilms can form on both biotic and abiotic surfaces, such as tissues and implanted medical devices. Once formed, biofilms are highly resistant to antifungal agents and the host immune system, and can act as a protected reservoir to seed disseminated infections. Here, we present several in vitro biofilm protocols, including protocols that are optimized for high-throughput screening of mutant libraries and antifungal compounds. We also present protocols to examine specific stages of biofilm development and protocols to evaluate interspecies biofilms that C. albicans forms with interacting microbial partners. © 2018 by John Wiley & Sons, Inc.
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Affiliation(s)
- Megha Gulati
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, Merced, California
| | - Matthew B Lohse
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California.,Department of Biology, BioSynesis, Inc., San Francisco, California
| | - Craig L Ennis
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, Merced, California.,Quantitative and Systems Biology Graduate Program, University of California, Merced, Merced, California
| | - Ruth E Gonzalez
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, Merced, California
| | - Austin M Perry
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, Merced, California.,Quantitative and Systems Biology Graduate Program, University of California, Merced, Merced, California
| | - Priyanka Bapat
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, Merced, California.,Quantitative and Systems Biology Graduate Program, University of California, Merced, Merced, California
| | - Ashley Valle Arevalo
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, Merced, California.,Quantitative and Systems Biology Graduate Program, University of California, Merced, Merced, California
| | - Diana L Rodriguez
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, Merced, California.,Quantitative and Systems Biology Graduate Program, University of California, Merced, Merced, California
| | - Clarissa J Nobile
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, Merced, California
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7
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Deng L, Xu-Monette ZY, Loghavi S, Manyam GC, Xia Y, Visco C, Huh J, Zhang L, Zhai Q, Wang Y, Qiu L, Dybkær K, Chiu A, Perry AM, Zhang S, Tzankov A, Rao H, Abramson J, Sohani AR, Xu M, Hsi ED, Zhu J, Ponzoni M, Wang S, Li L, Zhang M, Ferreri AJM, Parsons BM, Li Y, Piris MA, Medeiros LJ, Young KH. Primary testicular diffuse large B-cell lymphoma displays distinct clinical and biological features for treatment failure in rituximab era: a report from the International PTL Consortium. Leukemia 2015; 30:361-72. [DOI: 10.1038/leu.2015.237] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Revised: 08/15/2015] [Accepted: 08/18/2015] [Indexed: 12/15/2022]
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8
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Cameron ND, Enser M, Nute GR, Whittington FM, Penman JC, Fisken AC, Perry AM, Wood JD. Genotype with nutrition interaction on fatty acid composition of intramuscular fat and the relationship with flavour of pig meat. Meat Sci 2012; 55:187-95. [PMID: 22061084 DOI: 10.1016/s0309-1740(99)00142-4] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/1999] [Accepted: 09/28/1999] [Indexed: 10/18/2022]
Abstract
The effects of genotype, diet and the genotype with diet interaction on fatty acid composition of neutral lipid and phospholipid of intramuscular fat in pigs were examined. Pigs from four selection lines and a control line were fed isoenergetic diets, which differed in ileal digestible lysine:digestible energy (A: 0.40, C: 0.76 and E: 1.12 g lysine/MJ DE). The selected lines resulted from seven generations of selection for high daily food intake (DFI), lean food conversion ratio (LFC) and lean growth rate on ad-libitum (LGA) or restricted feeding regimes in a Large White population. During performance test, from 30 to 90 kg, pigs were fed on either ad-libitum or restricted (0.75 g/g ad-libitum daily food intake) feeding regimes. A trained sensory panel assessed intensities of pork flavour and abnormal flavour and the hedonic characteristics of flavour liking and overall acceptability. The proportion of neutral lipid in the LGA line was lower (0.64 v 0.75, s.e.d. 0.03) while the polyunsaturated:saturated (P:S) ratio of the LFC line (0.53 v 0.41, s.e.d. 0.05) was higher than the control line and other selection lines. The DFI line had a higher phospholipid n-6:n-3 ratio than other selection lines (14 v 11, s.e.d. 1.0). Diets C and E resulted in lower neutral lipid:phospholipid ratio (0.7 v 0.8, s.e.d. 0.01), n-6:n-3 ratios for both neutral lipid (5 v 13, s.e.d. 0.8) and phospholipids (7 v 20, s.e.d. 0.6) and a higher P:S ratio (0.5 v 0.3, s.e.d. 0.03) for neutral lipid than diet A. Neutral lipid fatty acids C18:2 n-6, C18:3 n-3, C20:3 n-6, C20:4 n-6, C20:5 n-3, C22:5 n-3 and C22:6 n-3 were negatively correlated with pork flavour (-0.30, s.e.d. 0.10), flavour liking (-0.33) and overall acceptability (-0.30). In contrast, the fatty acids C16:1, C18:1 ω9 and C18:1 ω11 were positively correlated with pork flavour (0.36), flavour liking (0.39) and overall acceptability (0.40). However, correlations for fatty acids in the phospholipid class were positive for C18:2 n-6, C20:4 n-6 and C22:4 n-6 with pork flavour (0.33), flavour liking (0.23) and overall acceptability (0.23). The proportion of neutral lipid had non-significant correlations with flavour traits; pork flavour (0.01), abnormal flavour (0.08), flavour liking (-0.03) and overall acceptability (0.03). The selection lines responded in a similar manner to the different diets, such that there was little evidence for genotype with nutrition interactions for fatty acid concentrations of neutral lipids and phospholipids. Selection for high lean growth will reduce intramuscular fat, but the increased relative amount of phospholipid and concentration of polyunsaturated fatty acids are unlikely to reduce eating quality. Nutritional effects on intramuscular fat characteristics were greater than genetic effects, such that nutritional approaches to feeding pigs will provide effective methods of reducing the n-6:n-3 fatty acid ratio of human dietary fat from pigmeat and improving human health.
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Affiliation(s)
- N D Cameron
- Roslin Institute (Edinburgh), Roslin, Midlothian EH25 9PS, UK
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9
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Ebert MA, Herbert CE, Spry NA, Harper CS, Perry AM, Poller J, Whittall D, Taylor R, Wilkinson S, Joseph DJ. System validation and work practice efficiency gains of a new localization method for stereotactic radiotherapy. Australas Radiol 2001; 45:182-8. [PMID: 11380361 DOI: 10.1046/j.1440-1673.2001.00873.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The increased procedural demands of stereotactic localization techniques when compared with conventional treatment practices reduces machine efficiency, an outcome likely to be greatly magnified by the introduction of fractionation to stereotactic techniques. Currently in Australia and New Zealand there are no guidelines for the definition of efficiency. We sought to devise a system to simultaneously validate the accuracy and efficiency of the technique. The frameless relocation methods employed in the Medtronic Sofamor Danek (MSD) stereotactic radiotherapy (SRT) system were studied in the clinical setting. Accuracy has been determined according to the accumulation of errors throughout the planning and treatment process. The clinical demands of the system (staffing and resources) were analysed relative to conventional treatment approaches. Timing studies indicate a mean time of 19.7 min for treatment of a daily SRT fraction (4-5 arcs, single isocentre). Cost and staffing requirements are similar to those for conventional radiotherapy. It is concluded that with the system used, SRT is efficient for routine clinical implementation, with the level of efficiency increasing with increasing patient numbers. It is recommended that a common acceptance standard be developed to allow cross-institutional comparison of the clinical efficiency of new treatment techniques.
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Affiliation(s)
- M A Ebert
- Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Australia.
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Buchanan M, Buyers WJL, Elliott RJ, Harley RT, Hayes W, Perry AM, Saville ID. Two-magnon raman scattering and infrared absorption in (MnZn)F2. ACTA ACUST UNITED AC 2001. [DOI: 10.1088/0022-3719/5/15/016] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [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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Harley RT, Hayes W, Perry AM, Smith SRP, Elliott RJ, Saville ID. Cooperative Jahn-Teller effects in the mixed crystals TbpGd1-pVO4and DypY1-pVO4. ACTA ACUST UNITED AC 2001. [DOI: 10.1088/0022-3719/7/17/022] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [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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13
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Ebert MA, Perry AM, Harper CS. Implementation of a stereotactic radiotherapy system. Australas Phys Eng Sci Med 1999; 22:145-52. [PMID: 10740887] [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] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The tests carried out on a recently-installed stereotactic radiotherapy system capable of fully frameless stereotaxy are outlined. The two principle investigations carried out on the planning system were a dosimetry test, and a test to verify the accuracy of localisation from CT examination through to patient treatment. The method employed in frameless relocation for fractionated stereotactic radiotherapy--position detection using stereoscopic infra-red cameras and a set of fiducials attached to a bite-block--was tested for reproducibility. The results of these tests suggest a mean accuracy in treatment localisation of 1.23 mm (maximum 2.72 mm) for single fraction techniques, and 1.77 mm (maximum 4.53 mm) for treatments involving repeated (frameless) localisation. The implications of these accuracies for treatment with single, multiple-fraction and multi-isocentre techniques are discussed.
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Affiliation(s)
- M A Ebert
- Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, WA
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Perry AM. Should legislatures practice medicine? N Engl J Med 1997; 337:1240; author reply 1241. [PMID: 9340519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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15
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Knowles TG, Warriss PD, Brown SN, Kestin SC, Edwards JE, Perry AM, Watkins PE, Phillips AJ. Effects of feeding, watering and resting intervals on lambs transported by road and ferry to France. Vet Rec 1996; 139:335-9. [PMID: 8903011 DOI: 10.1136/vr.139.14.335] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Three lorry loads, each of approximately 530 lambs, were monitored during August 1994 while they were transported from the Midlands to France. Each lorry underwent a similar journey, designed to study the effects of a) 22 hours on a lorry broken by two hours of feed, water and rest after 15 hours, b) 34 hours on a lorry broken by eight hours of feed, water and rest after 24 hours and c) 24 hours on a lorry and lairage for the following 48 hours. Measurements were made on 180 lambs in each load, of liveweight, plasma betahydroxybutyrate (BHB), non-esterified fatty acids (NEFA), urea, total protein, albumin, osmolality, creatine kinase (CK), cortisol and glucose, before, during and after transport. Twenty-four hours of transport resulted in changes in some of the variables measured that were little different from those observed after 24 hours of feed and water deprivation; however, the high ambient temperatures during the transport resulted in a greater degree of dehydration. For journeys longer than 15 hours a two-hour rest in lairage with access to water and a palatable food source was beneficial in allowing some slight recovery. Although all the differences were in the direction that would be expected with recovery, they were often small and, within the sensitivity of the study, were only significant for NEFA and C.K. For journeys longer than 24 hours, an eight-hour rest in lairage with access to water and a palatable food source was beneficial and allowed material realimentation and rehydration before further transport for up to 10 hours. After 24 hours of transport, however, liveweight, plasma urea, total protein and albumin had only returned to basal levels after 24 hours in lairage and plasma BHB, CK and osmolality after 48 hours of lairage.
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Affiliation(s)
- T G Knowles
- School of Veterinary Science, University of Bristol, Langford
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Wood JD, Brown SN, Nute GR, Whittington FM, Perry AM, Johnson SP, Enser M. Effects of breed, feed level and conditioning time on the tenderness of pork. Meat Sci 1996; 44:105-12. [PMID: 22060760 DOI: 10.1016/s0309-1740(96)00044-7] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/1995] [Accepted: 03/20/1996] [Indexed: 11/28/2022]
Affiliation(s)
- J D Wood
- Division of Food Animal Science, School of Veterinary Science, University of Bristol, Langford, Bristol BS18 7DY, UK
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Perry AM. The United States needs a health system like other countries. JAMA 1994; 271:1481; author reply 1482. [PMID: 8176819 DOI: 10.1001/jama.271.19.1481c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Haworth A, Perry AM. Data acquisition for linac based stereotactic radiosurgery. Australas Phys Eng Sci Med 1993; 16:49-56. [PMID: 8470998] [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] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In September 1991 a Philips Stereotactic Radiosurgery System (SRS 200) was installed in the Radiotherapy Department at Sir Charles Gairdner Hospital for use with an existing 6MV linear accelerator. The treatment planning software requires tables of Output Factors, Tissue Maximum Ratios (TMRs) and Off-Axis Ratios (OARs) for each specific linac/collimator set combination. Conventional techniques of acquiring radiation dose data for patient treatment planning were not suitable for the very small field sizes (5-30mm diameter) to be measured. Output Factors relative to a 100 x 100 mm field were measured using a large water tank and solid state diode detectors. The SRS 200 base frame which usually supports the special collimators could not be used with the tank in place and so a method for aligning the central axis of the beam, the SRS 200 collimators and diode was developed to improve the accuracy of measurement. TMRs were measured using two independent methods, similarly for the OARs. The first method of measuring TMRs made use of the large water tank and diode detectors. The second method employed the use of solid water phantom slabs seated on the base frame of the SRS 200. OARs were first measured with the solid water phantom slabs and diode; the second method made use of the technique of film dosimetry. Finally, a spherical water phantom was designed and built to check the total system accuracy. Agreement between sets of results measured by the independent methods was within 0.3% on average for TMRs and 0.25mm at the 50% dose level in most cases for the OARs.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- A Haworth
- Department of Medical Physics, Royal Perth Hospital, Western Australia
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Perry AM, Fox RA. Stereotactic radiosurgery. Australas Phys Eng Sci Med 1989; 12:233-40. [PMID: 2692549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Stereotactic radiosurgery is the accurate focusing of ionising radiation onto an intracranial target, and was pioneered in Sweden in the early 1950's. It has proven effective in the treatment of arteriovenous malformations, acoustic tumours and many other small brain lesions. In the last decade the commercial availability of a gamma ray system has led to other centres following the work in Stockholm; more recently, various techniques utilising linear accelerators, (LINACs), have been developed. Both types of system necessitated special dosimetry and treatment planning methods for the small, high dose-gradient circular fields. Localization of the lesions requires angiography, computerised tomography (CT) or magnetic resonance imaging (MRI).
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Klemp PF, Perry AM, Hedland-Thomas B, Stevenson S, Zucaro D. Commissioning of a linear accelerator with independent jaws: computerised data collection and transfer to a planning computer. Phys Med Biol 1988; 33:865-71. [PMID: 3212046 DOI: 10.1088/0031-9155/33/7/010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- P F Klemp
- Department of Medical Physics, Royal Perth Hospital, Western Australia, Australia
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Kirk J, Perry AM, Cater BR. Dose response experiments using the mouse tail model. Acta Radiol Oncol 1982; 21:27-31. [PMID: 6283794 DOI: 10.3109/02841868209133980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Radiation induced tail necrosis in BALB/c mice was used to investigate the effects of tissue temperature and local oxygenation on the radiation response. Single doses of 250 kV roentgen-rays were given over the temperature range 32.5 to 37 degrees C and dose response curves obtained. The temperature dependence of the response was shown to be consistent with changing hypoxic status by the derivation of a simple model; this has practical implications for the treatment of patients using simultaneously combined radiation therapy and hyperthermia.
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Hamlet R, Kirk J, Perry AM. An investigation of the alternating fractionation formula of the Cumulative Radiation Effect. Int J Radiat Biol Relat Stud Phys Chem Med 1980; 37:499-504. [PMID: 6967463 DOI: 10.1080/09553008014550621] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The alternating fractionation formula of the Cumulative Radiation Effect (CRE) system was investigated using the mouse intestinal crypt system as a method of assessment of the amount of radiation damage in a normal tissue. The experimental results revealed that the formula is correct in predicting an increased effect with alternating large and small sized fractions, when compared with a standard schedule where the fraction size was kept constant but achieved the same total dose. However, the results also demonstrated that the order in which the alternate fractions were administered affected the amount of radiation damage produced in the tissue. This observation is in contradiction to another prediction of the formula, that the order in which equal numbers of fractions of different magnitudes are administered, will have no effect on the biological end point. The formula, therefore, is only an approximate model of radiation damage in normal tissue and much more information is required before it can be improved upon.
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Abstract
The cumulative radiation effect (CRE) is one of several empirical scalar descriptions of biological effect which enable corrections to be made for gaps in radiotherapy treatment. Predictions of this theory were tested using mouse crypt regeneration and mouse skin as biological models. These experimental results are discussed in terms of the dependence of tissue regeneration potential during a gap on the biological effect achieved before the gap, and on gap length. A hypothesis is proposed to reconcile the apparent conflict between the two experiments. While the simple exponential gap formulation of the CRE is seen to be inadequate, insufficient data are available at present to modify it.
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Abstract
The assessment of a non-invasive technique for measuring deep body temperature is described. An experimental system, in which the insulating effect of subcutaneous fat thickness could be simulated, was designed to test the deep body thermometer (DBT). The assumption that the instrument produced zero temperature gradient was found to be incorrect, and a mathematical model was developed which showed that the cyclically varying output of the device is an inherent property of its design. The accuracy and response time were investigated as a function of tissue thickness to assess the instrument's clinical usefulness.
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