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Leiter O, Brici D, Fletcher SJ, Yong XLH, Widagdo J, Matigian N, Schroer AB, Bieri G, Blackmore DG, Bartlett PF, Anggono V, Villeda SA, Walker TL. Platelet-derived exerkine CXCL4/platelet factor 4 rejuvenates hippocampal neurogenesis and restores cognitive function in aged mice. Nat Commun 2023; 14:4375. [PMID: 37587147 PMCID: PMC10432533 DOI: 10.1038/s41467-023-39873-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [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: 09/28/2022] [Accepted: 06/20/2023] [Indexed: 08/18/2023] Open
Abstract
The beneficial effects of physical activity on brain ageing are well recognised, with exerkines, factors that are secreted into the circulation in response to exercise, emerging as likely mediators of this response. However, the source and identity of these exerkines remain unclear. Here we provide evidence that an anti-geronic exerkine is secreted by platelets. We show that platelets are activated by exercise and are required for the exercise-induced increase in hippocampal precursor cell proliferation in aged mice. We also demonstrate that increasing the systemic levels of the platelet-derived exerkine CXCL4/platelet factor 4 (PF4) ameliorates age-related regenerative and cognitive impairments in a hippocampal neurogenesis-dependent manner. Together these findings highlight the role of platelets in mediating the rejuvenating effects of exercise during physiological brain ageing.
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Affiliation(s)
- Odette Leiter
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - David Brici
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Stephen J Fletcher
- Centre for Horticultural Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Xuan Ling Hilary Yong
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Jocelyn Widagdo
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Nicholas Matigian
- Queensland Cyber Infrastructure Foundation Ltd, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Adam B Schroer
- Department of Anatomy, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Gregor Bieri
- Department of Anatomy, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Daniel G Blackmore
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Perry F Bartlett
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Victor Anggono
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Saul A Villeda
- Department of Anatomy, University of California San Francisco, San Francisco, CA, 94143, USA
- The Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA, 94143, USA
- Bakar Aging Research Institute, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Tara L Walker
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.
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2
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Salisbury LJ, Fletcher SJ, Stok JE, Churchman LR, Blanchfield JT, De Voss JJ. Characterization of the cholesterol biosynthetic pathway in Dioscorea transversa. J Biol Chem 2023:104768. [PMID: 37142228 DOI: 10.1016/j.jbc.2023.104768] [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: 10/10/2022] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 05/06/2023] Open
Abstract
Cholesterol is the precursor of bioactive plant metabolites such as steroidal saponins. An Australian plant, Dioscorea transversa, produces only two steroidal saponins: 1β-hydroxyprotoneogracillin and protoneogracillin. Here, we used D. transversa as a model in which to elucidate the biosynthetic pathway to cholesterol, a precursor to these compounds. Preliminary transcriptomes of D. transversa rhizome and leaves were constructed, annotated, and analyzed. We identified a novel sterol side chain reductase (SSR) as a key initiator of cholesterol biosynthesis in this plant. By complementation in yeast, we determine that this SSR reduces Δ24,28 double bonds required for phytosterol biogenesis, as well as Δ24,25 double bonds. The latter function is believed to initiate cholesterogenesis by reducing cycloartenol to cycloartanol. Through heterologous expression, purification and enzymatic reconstitution we also demonstrate that the D. transversa sterol demethylase (CYP51) effectively demethylates obtusifoliol, an intermediate of phytosterol biosynthesis and 4-desmethyl-24,25-dihydrolanosterol, a postulated downstream intermediate of cholesterol biosynthesis. In summary, we investigated specific steps of the cholesterol biosynthetic pathway, providing further insight into the downstream production of bioactive steroidal saponin metabolites.
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Fletcher SJ, Peters JR, Olaya C, Persley DM, Dietzgen RG, Carroll BJ, Pappu H, Mitter N. Tospoviruses Induce Small Interfering RNAs Targeting Viral Sequences and Endogenous Transcripts in Solanaceous Plants. Pathogens 2022; 11:pathogens11070745. [PMID: 35889991 PMCID: PMC9317859 DOI: 10.3390/pathogens11070745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/22/2022] [Accepted: 06/28/2022] [Indexed: 02/01/2023] Open
Abstract
Tospoviruses infect numerous crop species worldwide, causing significant losses throughout the supply chain. As a defence mechanism, plants use RNA interference (RNAi) to generate virus-derived small-interfering RNAs (vsiRNAs), which target viral transcripts for degradation. Small RNA sequencing and in silico analysis of capsicum and N. benthamiana infected by tomato spotted wilt virus (TSWV) or capsicum chlorosis virus (CaCV) demonstrated the presence of abundant vsiRNAs, with host-specific differences evident for each pathosystem. Despite the biogenesis of vsiRNAs in capsicum and N. benthamiana, TSWV and CaCV viral loads were readily detectable. In response to tospovirus infection, the solanaceous host species also generated highly abundant virus-activated small interfering RNAs (vasiRNAs) against many endogenous transcripts, except for an N. benthamiana accession lacking a functional RDR1 gene. Strong enrichment for ribosomal protein-encoding genes and for many genes involved in protein processing in the endoplasmic reticulum suggested co-localisation of viral and endogenous transcripts as a basis for initiating vasiRNA biogenesis. RNA-seq and RT-qPCR-based analyses of target transcript expression revealed an inconsistent role for vasiRNAs in modulating gene expression in N. benthamiana, which may be characteristic of this tospovirus-host pathosystem.
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Affiliation(s)
- Stephen J. Fletcher
- Centre for Horticultural Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia; (S.J.F.); (J.R.P.); (R.G.D.)
| | - Jonathan R. Peters
- Centre for Horticultural Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia; (S.J.F.); (J.R.P.); (R.G.D.)
| | - Cristian Olaya
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA;
| | - Denis M. Persley
- Queensland Department of Agriculture and Fisheries, AgriScience Queensland, EcoSciences Precinct, Dutton Park, Brisbane, QLD 4102, Australia;
| | - Ralf G. Dietzgen
- Centre for Horticultural Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia; (S.J.F.); (J.R.P.); (R.G.D.)
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia;
| | - Bernard J. Carroll
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia;
| | - Hanu Pappu
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA;
- Correspondence: (H.P.); (N.M.)
| | - Neena Mitter
- Centre for Horticultural Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia; (S.J.F.); (J.R.P.); (R.G.D.)
- Correspondence: (H.P.); (N.M.)
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Jain RG, Fletcher SJ, Manzie N, Robinson KE, Li P, Lu E, Brosnan CA, Xu ZP, Mitter N. Foliar application of clay-delivered RNA interference for whitefly control. Nat Plants 2022; 8:535-548. [PMID: 35577960 DOI: 10.1038/s41477-022-01152-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 04/11/2022] [Indexed: 06/15/2023]
Abstract
Whitefly (Bemisia tabaci) is a phloem-feeding global agricultural pest belonging to the order Hemiptera. Foliar application of double-stranded RNA (dsRNA) represents an attractive avenue for pest control; however, limited uptake and phloem availability of the dsRNA has restricted the development of RNA interference (RNAi)-based biopesticides against sap-sucking insects. Following high-throughput single and combinational target gene identification for additive effects, we report here that foliar application of dsRNA loaded onto layered double hydroxide (LDH), termed BioClay, can effectively disrupt multiple whitefly developmental stages in planta. Adjuvants were shown to enhance uptake and movement of foliar-applied dsRNA to vascular bundles and into the whitefly. Notably, delivering the dsRNA as a BioClay spray instead of as naked dsRNA improved protection against immature insect stages, demonstrating the platform's potential to extend the benefits offered by RNA insecticides towards complete life cycle control of whitefly and potentially other pests.
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Affiliation(s)
- Ritesh G Jain
- Queensland Alliance for Agriculture and Food Innovation, Centre for Horticultural Science, The University of Queensland, St Lucia, Queensland, Australia
| | - Stephen J Fletcher
- Queensland Alliance for Agriculture and Food Innovation, Centre for Horticultural Science, The University of Queensland, St Lucia, Queensland, Australia
| | - Narelle Manzie
- Queensland Alliance for Agriculture and Food Innovation, Centre for Horticultural Science, The University of Queensland, St Lucia, Queensland, Australia
| | - Karl E Robinson
- Queensland Alliance for Agriculture and Food Innovation, Centre for Horticultural Science, The University of Queensland, St Lucia, Queensland, Australia
| | - Peng Li
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Queensland, Australia
| | - Elvin Lu
- Queensland Alliance for Agriculture and Food Innovation, Centre for Horticultural Science, The University of Queensland, St Lucia, Queensland, Australia
| | - Christopher A Brosnan
- Queensland Alliance for Agriculture and Food Innovation, Centre for Horticultural Science, The University of Queensland, St Lucia, Queensland, Australia
| | - Zhi Ping Xu
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Queensland, Australia
| | - Neena Mitter
- Queensland Alliance for Agriculture and Food Innovation, Centre for Horticultural Science, The University of Queensland, St Lucia, Queensland, Australia.
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Nath O, Fletcher SJ, Hayward A, Shaw LM, Masouleh AK, Furtado A, Henry RJ, Mitter N. A haplotype resolved chromosomal level avocado genome allows analysis of novel avocado genes. Hortic Res 2022; 9:uhac157. [PMID: 36204209 PMCID: PMC9531333 DOI: 10.1093/hr/uhac157] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 08/01/2022] [Accepted: 07/04/2022] [Indexed: 06/16/2023]
Abstract
Avocado (Persea americana) is a member of the magnoliids, an early branching lineage of angiosperms that has high value globally with the fruit being highly nutritious. Here, we report a chromosome-level genome assembly for the commercial avocado cultivar Hass, which represents 80% of the world's avocado consumption. The DNA contigs produced from Pacific Biosciences HiFi reads were further assembled using a previously published version of the genome supported by a genetic map. The total assembly was 913 Mb with a contig N50 of 84 Mb. Contigs assigned to the 12 chromosomes represented 874 Mb and covered 98.8% of benchmarked single-copy genes from embryophytes. Annotation of protein coding sequences identified 48 915 avocado genes of which 39 207 could be ascribed functions. The genome contained 62.6% repeat elements. Specific biosynthetic pathways of interest in the genome were investigated. The analysis suggested that the predominant pathway of heptose biosynthesis in avocado may be through sedoheptulose 1,7 bisphosphate rather than via alternative routes. Endoglucanase genes were high in number, consistent with avocado using cellulase for fruit ripening. The avocado genome appeared to have a limited number of translocations between homeologous chromosomes, despite having undergone multiple genome duplication events. Proteome clustering with related species permitted identification of genes unique to avocado and other members of the Lauraceae family, as well as genes unique to species diverged near or prior to the divergence of monocots and eudicots. This genome provides a tool to support future advances in the development of elite avocado varieties with higher yields and fruit quality.
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Affiliation(s)
- Onkar Nath
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane 4072 Australia
| | - Stephen J Fletcher
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane 4072 Australia
| | - Alice Hayward
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane 4072 Australia
| | - Lindsay M Shaw
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane 4072 Australia
| | - Ardashir Kharabian Masouleh
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane 4072 Australia
| | - Agnelo Furtado
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane 4072 Australia
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Nath O, Fletcher SJ, Hayward A, Shaw LM, Agarwal R, Furtado A, Henry RJ, Mitter N. A Comprehensive High-Quality DNA and RNA Extraction Protocol for a Range of Cultivars and Tissue Types of the Woody Crop Avocado. Plants 2022; 11:plants11030242. [PMID: 35161230 PMCID: PMC8838124 DOI: 10.3390/plants11030242] [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] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 01/11/2023]
Abstract
High-quality DNA and RNA forms the basis of genomic and genetic investigations. The extraction of DNA and RNA from woody trees, like avocado (Persea americana Mill.), is challenging due to compounds which interact with nucleic acids and influence separation. Previously reported methods of DNA and RNA extraction from avocado have issues of low yield, quality and applicability across different cultivars and tissue types. In the current study, methods have been optimised for high-quality DNA extraction from 40 avocado cultivars and RNA extraction from multiple tissue types, including roots, stem, leaves, flowers and fruits. The method is based on the modification of the cetyltrimethylammonium bromide buffer, centred around the specific optimisation of chemicals, such as sodium dodecyl sulphate, polyvinylpyrrolidone, sodium sulphite, polyethylene glycol and β-mercaptoethanol. The DNA extraction method yielded high-molecular weight DNA from the leaf tissue of 40 avocado cultivars belonging to Mexican, Guatemalan and West Indian avocado horticultural groups. The method was further optimised for RNA extraction from different avocado plant parts, enabling extraction using amounts as low as ~10 mg of starting material. The DNA and RNA extracted was successfully used for long- and short-read sequencing and gene expression analysis. The methods developed may also be applicable to other recalcitrant plant species.
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Jain RG, Robinson KE, Fletcher SJ, Mitter N. RNAi-Based Functional Genomics in Hemiptera. Insects 2020; 11:E557. [PMID: 32825516 PMCID: PMC7564473 DOI: 10.3390/insects11090557] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/17/2020] [Accepted: 08/17/2020] [Indexed: 01/05/2023]
Abstract
RNA interference (RNAi) is a powerful approach for sequence-specific gene silencing, displaying tremendous potential for functional genomics studies in hemipteran insects. Exploiting RNAi allows the biological roles of critical genes to be defined and aids the development of RNAi-based biopesticides. In this review, we provide context to the rapidly expanding field of RNAi-based functional genomics studies in hemipteran insects. We highlight the most widely used RNAi delivery strategies, including microinjection, oral ingestion and topical application. Additionally, we discuss the key variables affecting RNAi efficacy in hemipteran insects, including insect life-stage, gene selection, the presence of nucleases, and the role of core RNAi machinery. In conclusion, we summarise the application of RNAi in functional genomics studies in Hemiptera, focusing on genes involved in reproduction, behaviour, metabolism, immunity and chemical resistance across 33 species belonging to 14 families.
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Affiliation(s)
| | - Karl E. Robinson
- Queensland Alliance for Agriculture and Food Innovation, Centre for Horticultural Sciences, The University of Queensland, Brisbane 4072, Queensland, Australia; (R.G.J.); (S.J.F.); (N.M.)
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Mendelsohn ML, Gathmann A, Kardassi D, Sachana M, Hopwood EM, Dietz-Pfeilstetter A, Michelsen-Correa S, Fletcher SJ, Székács A. Summary of Discussions From the 2019 OECD Conference on RNAi Based Pesticides. Front Plant Sci 2020; 11:740. [PMID: 32547591 PMCID: PMC7274041 DOI: 10.3389/fpls.2020.00740] [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] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 05/08/2020] [Indexed: 06/11/2023]
Abstract
RNA interference (RNAi) is a biological process in which double-stranded ribonucleic acid (dsRNA) molecules inhibit protein expression. In recent years, the application of dsRNA has been used in the development of agricultural products for pest control. The 2019 Organisation for Economic Cooperation and Development (OECD) Conference on RNAi Based Pesticides ("the Conference") brought together academic, industry, and government experts in various aspects of RNAi to discuss the current state of knowledge and topics to help in developing considerations for risk assessment. The Conference focused on environment, with some discussion of human health. Along with presentations on the use of dsRNA-based products in agriculture, government regulation, risk assessment, and a background on the Draft OECD Working Paper on "Considerations for the Environmental Risk Assessment of the Application of Sprayed or Externally Applied dsRNA-Based Pesticides" ("OECD Working Paper"), the Conference included panel discussions from presenters at the end of each session and a larger discussion session with Conference participants on the environmental fate of dsRNA, non-target organism (NTO) risk assessment, and human health risk assessment. This paper summarizes input from presenters and Conference participants during these discussions. Key considerations from these discussions have already been incorporated into the OECD Working Paper, that once finalized and published, will facilitate regulators in evaluating externally applied dsRNA-based products for potential environmental risks.
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Affiliation(s)
- Michael L. Mendelsohn
- Biopesticides and Pollution Prevention Division, Office of Pesticide Programs, United States Environmental Protection Agency, Washington, DC, United States
| | - Achim Gathmann
- Federal Office of Consumer Protection and Food Safety, Department of Plant Protection Products, Unit Environment, Braunschweig, Germany
| | - Dimitra Kardassi
- Pesticide Peer Review Unit, Scientific Evaluation of Regulated Products Directorate, European Food Safety Agency, Parma, Italy
| | - Magdalini Sachana
- Environment Health and Safety Division, Environment Directorate, Organisation for Economic Cooperation and Development, Paris, France
| | - Emily M. Hopwood
- Health Evaluation Directorate, Pest Management Regulatory Agency, Health Canada, Ottawa, ON, Canada
| | - Antje Dietz-Pfeilstetter
- Institute for Biosafety in Plant Biotechnology, Julius Kühn-Institut, Federal Research Centre for Cultivated Plants, Braunschweig, Germany
| | - Stephani Michelsen-Correa
- Science and Technology Policy Fellow, American Association for the Advancement of Science, Washington, DC, United States
| | - Stephen J. Fletcher
- Centre for Horticultural Science, Queensland Alliance for Agriculture and Food Innovation, University of Queensland, St. Lucia, QLD, Australia
| | - András Székács
- Agro-Environmental Research Institute, National Agricultural Research and Innovation Centre, Budapest, Hungary
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Cao J, Gursanscky NR, Fletcher SJ, Sawyer A, Wadia M, McKeough L, Coleman M, Dressel U, Taochy C, Mitter N, Vaucheret H, Carroll BJ. Can-Seq: a PCR and DNA sequencing strategy for identifying new alleles of known and candidate genes. Plant Methods 2020; 16:16. [PMID: 32082406 PMCID: PMC7017465 DOI: 10.1186/s13007-020-0555-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 01/17/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND Forward genetic screens are a powerful approach for identifying the genes contributing to a trait of interest. However, mutants arising in genes already known can obscure the identification of new genes contributing to the trait. Here, we describe a strategy called Candidate gene-Sequencing (Can-Seq) for rapidly identifying and filtering out mutants carrying new alleles of known and candidate genes. RESULTS We carried out a forward genetic screen and identified 40 independent Arabidopsis mutants with defects in systemic spreading of RNA interference (RNAi), or more specifically in root-to-shoot transmission of post-transcriptional gene silencing (rtp). To classify the mutants as either representing a new allele of a known or candidate gene versus carrying a mutation in an undiscovered gene, bulk genomic DNA from up to 23 independent mutants was used as template to amplify a collection of 47 known or candidate genes. These amplified sequences were combined into Can-Seq libraries and deep sequenced. Subsequently, mutations in the known and candidate genes were identified using a custom Snakemake script (https://github.com/Carroll-Lab/can_seq), and PCR zygosity tests were then designed and used to identify the individual mutants carrying each mutation. Using this approach, we showed that 28 of the 40 rtp mutants carried homozygous nonsense, missense or splice site mutations in one or more of the 47 known or candidate genes. We conducted complementation tests to demonstrate that several of the candidate mutations were responsible for the rtp defect. Importantly, by exclusion, the Can-Seq pipeline also identified rtp mutants that did not carry a causative mutation in any of the 47 known and candidate genes, and these mutants represent an undiscovered gene(s) required for systemic RNAi. CONCLUSIONS Can-Seq offers an accurate, cost-effective method for classifying new mutants into known versus unknown genes. It has several advantages over existing genetic and DNA sequencing approaches that are currently being used in forward genetic screens for gene discovery. Using Can-Seq in conjunction with map-based gene cloning is a cost-effective approach towards identifying the full complement of genes contributing to a trait of interest.
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Affiliation(s)
- Jiangling Cao
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Nial R. Gursanscky
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Stephen J. Fletcher
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072 Australia
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Anne Sawyer
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072 Australia
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Mehershad Wadia
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Lachlan McKeough
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Marek Coleman
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Uwe Dressel
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Christelle Taochy
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072 Australia
- Institut Jean-Pierre Bourgin, UMR 1318, INRA AgroParisTech CNRS, Université Paris-Saclay, 78000 Versailles, France
| | - Neena Mitter
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Hervé Vaucheret
- Institut Jean-Pierre Bourgin, UMR 1318, INRA AgroParisTech CNRS, Université Paris-Saclay, 78000 Versailles, France
| | - Bernard J. Carroll
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072 Australia
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Fletcher SJ, Reeves PT, Hoang BT, Mitter N. A Perspective on RNAi-Based Biopesticides. Front Plant Sci 2020; 11:51. [PMID: 32117388 PMCID: PMC7028687 DOI: 10.3389/fpls.2020.00051] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 01/15/2020] [Indexed: 05/20/2023]
Abstract
Sustainable agriculture relies on practices and technologies that combine effectiveness with a minimal environmental footprint. RNA interference (RNAi), a eukaryotic process in which transcript expression is reduced in a sequence-specific manner, can be co-opted for the control of plant pests and pathogens in a topical application system. Double-stranded RNA (dsRNA), the key trigger molecule of RNAi, has been shown to provide protection without the need for integration of dsRNA-expressing constructs as transgenes. Consequently, development of RNA-based biopesticides is gaining momentum as a narrow-spectrum alternative to chemical-based control measures, with pests and pathogens targeted with accuracy and specificity. Limitations for a commercially viable product to overcome include stable delivery of the topically applied dsRNA and extension of the duration of protection. In addition to the research focus on delivery of dsRNA, development of regulatory frameworks, risk identification, and establishing avoidance and mitigation strategies is key to widespread deployment of topical RNAi technologies. Once in place, these measures will provide the crop protection industry with the certainty necessary to expend resources on the development of innovative dsRNA-based products. Readily evident risks to human health appear minimal, with multiple barriers to uptake and a long history of consumption of dsRNA from plant material. Unintended impacts to the environment are expected to be most apparent in species closely related to the target. Holistic design practices, which incorporate bioinformatics-based dsRNA selection along with experimental testing, represent important techniques for elimination of adverse impacts.
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Affiliation(s)
- Stephen J. Fletcher
- Centre for Horticultural Science, Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Saint Lucia, QLD, Australia
| | | | - Bao Tram Hoang
- Centre for Horticultural Science, Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Saint Lucia, QLD, Australia
| | - Neena Mitter
- Centre for Horticultural Science, Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Saint Lucia, QLD, Australia
- *Correspondence: Neena Mitter,
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Worrall EA, Bravo-Cazar A, Nilon AT, Fletcher SJ, Robinson KE, Carr JP, Mitter N. Exogenous Application of RNAi-Inducing Double-Stranded RNA Inhibits Aphid-Mediated Transmission of a Plant Virus. Front Plant Sci 2019; 10:265. [PMID: 30930914 PMCID: PMC6429036 DOI: 10.3389/fpls.2019.00265] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 02/19/2019] [Indexed: 05/19/2023]
Abstract
Plant viruses are difficult to control, and they decrease both the quality and yield of crops, thus threatening global food security. A new approach that uses topical application of double-stranded RNA (dsRNA) to induce antiviral RNA-interference has been shown to be effective at preventing virus infection in a range of plants following mechanical inoculation. In this study, topical application of dsRNA was effective against mechanical inoculation and aphid-mediated inoculation with the potyvirus bean common mosaic virus (BCMV). Topical application of dsRNAs targeting either the coding region of the potyviral nuclear inclusion b (NIb) protein (BCMVNIb-dsRNA) or the coat protein (CP) coding region (BCMVCP-dsRNA) protected Nicotiana benthamiana and cowpea (Vigna unguiculata) plants against mechanical inoculation with BCMV. BCMVCP-dsRNA was selected for subsequent aphid transmission experiments. BCMVCP-dsRNA was loaded onto layered double hydroxide nanoparticles to form BCMVCP-BioClay which is a more stable formulation for delivering dsRNA than naked dsRNA. BCMVCP-BioClay was shown to be successful in protecting plants against BCMV transmission by the aphid Myzus persicae. Spraying detached N. benthamiana leaves with BCMVCP-BioClay 5 days prior to exposure to viruliferous aphids protected the leaves from infection by BCMV. Importantly, spraying of intact N. benthamiana and cowpea plants with BCMVCP-BioClay 5 days prior to exposure to viruliferous aphids protected plants of both species from BCMV infection. This study demonstrates that topical application of dsRNA using BioClay protects plants from aphid-mediated virus transmission, which is an important first step toward developing practical application of this approach in crop protection.
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Affiliation(s)
- Elizabeth A. Worrall
- Centre of Horticultural Science, Queensland Alliance of Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD, Australia
| | - Ana Bravo-Cazar
- Department of Plant Sciences, Cambridge University, Cambridge, United Kingdom
| | - Alexander T. Nilon
- Centre of Horticultural Science, Queensland Alliance of Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD, Australia
| | - Stephen J. Fletcher
- Centre of Horticultural Science, Queensland Alliance of Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD, Australia
| | - Karl E. Robinson
- Centre of Horticultural Science, Queensland Alliance of Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD, Australia
| | - John P. Carr
- Department of Plant Sciences, Cambridge University, Cambridge, United Kingdom
- *Correspondence: Neena Mitter,
| | - Neena Mitter
- Centre of Horticultural Science, Queensland Alliance of Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD, Australia
- *Correspondence: Neena Mitter,
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Worrall EA, Hayward AC, Fletcher SJ, Mitter N. Molecular characterization and analysis of conserved potyviral motifs in bean common mosaic virus (BCMV) for RNAi-mediated protection. Arch Virol 2018; 164:181-194. [DOI: 10.1007/s00705-018-4065-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 09/21/2018] [Indexed: 01/01/2023]
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13
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Eimer H, Sureshkumar S, Singh Yadav A, Kraupner-Taylor C, Bandaranayake C, Seleznev A, Thomason T, Fletcher SJ, Gordon SF, Carroll BJ, Balasubramanian S. RNA-Dependent Epigenetic Silencing Directs Transcriptional Downregulation Caused by Intronic Repeat Expansions. Cell 2018; 174:1095-1105.e11. [PMID: 30057112 DOI: 10.1016/j.cell.2018.06.044] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 04/20/2018] [Accepted: 06/22/2018] [Indexed: 01/07/2023]
Abstract
Transcriptional downregulation caused by intronic triplet repeat expansions underlies diseases such as Friedreich's ataxia. This downregulation of gene expression is coupled with epigenetic changes, but the underlying mechanisms are unknown. Here, we show that an intronic GAA/TTC triplet expansion within the IIL1 gene of Arabidopsis thaliana results in accumulation of 24-nt short interfering RNAs (siRNAs) and repressive histone marks at the IIL1 locus, which in turn causes its transcriptional downregulation and an associated phenotype. Knocking down DICER LIKE-3 (DCL3), which produces 24-nt siRNAs, suppressed transcriptional downregulation of IIL1 and the triplet expansion-associated phenotype. Furthermore, knocking down additional components of the RNA-dependent DNA methylation (RdDM) pathway also suppressed both transcriptional downregulation of IIL1 and the repeat expansion-associated phenotype. Thus, our results show that triplet repeat expansions can lead to local siRNA biogenesis, which in turn downregulates transcription through an RdDM-dependent epigenetic modification.
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Affiliation(s)
- Hannes Eimer
- School of Biological Sciences, Monash University, Clayton Campus, VIC 3800, Australia
| | - Sridevi Sureshkumar
- School of Biological Sciences, Monash University, Clayton Campus, VIC 3800, Australia
| | - Avilash Singh Yadav
- School of Biological Sciences, Monash University, Clayton Campus, VIC 3800, Australia
| | | | - Champa Bandaranayake
- School of Biological Sciences, Monash University, Clayton Campus, VIC 3800, Australia
| | - Andrei Seleznev
- School of Biological Sciences, Monash University, Clayton Campus, VIC 3800, Australia
| | - Tamblyn Thomason
- School of Biological Sciences, Monash University, Clayton Campus, VIC 3800, Australia
| | - Stephen J Fletcher
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia QLD 4072, Australia
| | | | - Bernard J Carroll
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia QLD 4072, Australia
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Abstract
Metabolic acidosis is considered deleterious but is common in post-surgical patients admitted to intensive care unit. We evaluated the prevalence and time course of metabolic acidosis in elective major surgery, and generated hypotheses about causes, by hourly arterial blood sampling in 92 patients. Metabolic acidosis began before incision and most had occurred by the next hour. Seventy-eight per cent of patients had a significant metabolic acidosis post-operatively. Two overlapping phases were observed. The early phase started before incision, characterised by a rising chloride and falling anion gap, unrelated to saline use. The late phase was partly associated with lactate, related to surgery type, and early fluids appeared protective. There was a trend towards longer intensive care unit (+1.3 days) and hospital (+3.2 days) stay with metabolic acidosis. This is the first large study of the evolution of this common finding, demonstrating a pre-incision component. The early phase appears unavoidable or unpredictable, but the late phase might be modified by early fluid administration. It remains unclear whether acidosis of this type should be avoided.
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Affiliation(s)
- T O Lawton
- Bradford Teaching Hospitals NHS Trust, Bradford, UK
| | - A Quinn
- Bradford Teaching Hospitals NHS Trust, Bradford, UK
| | - S J Fletcher
- Mid Yorkshire Hospitals NHS Trust, Wakefield, UK
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Fletcher SJ, Boden M, Mitter N, Carroll BJ. SCRAM: a pipeline for fast index-free small RNA read alignment and visualization. Bioinformatics 2018; 34:2670-2672. [DOI: 10.1093/bioinformatics/bty161] [Citation(s) in RCA: 8] [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] [Received: 09/21/2017] [Accepted: 03/14/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Stephen J Fletcher
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD, Australia
- Centre for Horticultural Science, Queensland Alliance for Agriculture and Food Innovation, St Lucia, QLD, Australia
| | - Mikael Boden
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD, Australia
| | - Neena Mitter
- Centre for Horticultural Science, Queensland Alliance for Agriculture and Food Innovation, St Lucia, QLD, Australia
| | - Bernard J Carroll
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, QLD, Australia
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Taochy C, Gursanscky NR, Cao J, Fletcher SJ, Dressel U, Mitter N, Tucker MR, Koltunow AMG, Bowman JL, Vaucheret H, Carroll BJ. A Genetic Screen for Impaired Systemic RNAi Highlights the Crucial Role of DICER-LIKE 2. Plant Physiol 2017; 175:1424-1437. [PMID: 28928141 PMCID: PMC5664484 DOI: 10.1104/pp.17.01181] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 09/14/2017] [Indexed: 05/17/2023]
Abstract
Posttranscriptional gene silencing (PTGS) of transgenes involves abundant 21-nucleotide small interfering RNAs (siRNAs) and low-abundance 22-nucleotide siRNAs produced from double-stranded RNA (dsRNA) by DCL4 and DCL2, respectively. However, DCL2 facilitates the recruitment of RNA-DEPENDENT RNA POLYMERASE 6 (RDR6) to ARGONAUTE 1-derived cleavage products, resulting in more efficient amplification of secondary and transitive dsRNA and siRNAs. Here, we describe a reporter system where RDR6-dependent PTGS is initiated by restricted expression of an inverted-repeat dsRNA specifically in the Arabidopsis (Arabidopsis thaliana) root tip, allowing a genetic screen to identify mutants impaired in RDR6-dependent systemic PTGS. Our screen identified dcl2 but not dcl4 mutants. Moreover, grafting experiments showed that DCL2, but not DCL4, is required in both the source rootstock and the recipient shoot tissue for efficient RDR6-dependent systemic PTGS. Furthermore, dcl4 rootstocks produced more DCL2-dependent 22-nucleotide siRNAs than the wild type and showed enhanced systemic movement of PTGS to grafted shoots. Thus, along with its role in recruiting RDR6 for further amplification of PTGS, DCL2 is crucial for RDR6-dependent systemic PTGS.
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Affiliation(s)
- Christelle Taochy
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia
- Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Institut National de la Recherche Agronomique AgroParisTech Centre National de la Recherche Scientifique, Université Paris-Saclay, 78000 Versailles, France
| | - Nial R Gursanscky
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Jiangling Cao
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Stephen J Fletcher
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Uwe Dressel
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Neena Mitter
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Matthew R Tucker
- Commonwealth Scientific and Industrial Research Organization Agriculture, Waite Campus, Urrbrae, South Australia 5064, Australia
- School of Agriculture, Food, and Wine, University of Adelaide, Waite Campus, Adelaide, South Australia 5064, Australia
| | - Anna M G Koltunow
- Commonwealth Scientific and Industrial Research Organization Agriculture, Waite Campus, Urrbrae, South Australia 5064, Australia
| | - John L Bowman
- School of Biological Sciences, Monash University, Clayton Campus, Melbourne, Victoria 3800, Australia
| | - Hervé Vaucheret
- Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Institut National de la Recherche Agronomique AgroParisTech Centre National de la Recherche Scientifique, Université Paris-Saclay, 78000 Versailles, France
| | - Bernard J Carroll
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland 4072, Australia
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Albutt AK, O'Hara JK, Conner MT, Fletcher SJ, Lawton RJ. Is there a role for patients and their relatives in escalating clinical deterioration in hospital? A systematic review. Health Expect 2017; 20:818-825. [PMID: 27785868 PMCID: PMC5600219 DOI: 10.1111/hex.12496] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2016] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Measures exist to improve early recognition of, and response to, deteriorating patients in hospital. However, deteriorating patients continue to go unrecognized. To address this, interventions have been developed that invite patients and relatives to escalate patient deterioration to a rapid response team (RRT). OBJECTIVE To systematically review articles that describe these interventions and investigate their effectiveness at reducing preventable deterioration. SEARCH STRATEGY Following PRISMA guidelines, four electronic databases and two web search engines were searched to identify literature investigating patient and relative led escalation. INCLUSION CRITERIA Articles investigating the implementation or use of systems involving patients and relatives in the detection of clinical patient deterioration and escalation of patient care to address any clinical or non-clinical outcomes were included. Articles' eligibility was validated by a second reviewer (20%). DATA EXTRACTION Data were extracted according to pre-defined criteria. DATA SYNTHESIS Narrative synthesis was applied to included studies. MAIN RESULTS Nine empirical studies and 36 grey literature articles were included in the review. Limited studies were conducted to establish the clinical effectiveness of patient and relative led escalation. Instead, studies investigated the impact of this intervention on health-care staff and available resources. Although appropriate, this reflects the infancy of research in this area. Patients and relatives did not overwhelm resources by activating the RRT. However, they did activate it to address concerns unrelated to patient deterioration. CONCLUSIONS Activating a RRT may not be the most appropriate or cost-effective method of resolving non-life-threatening concerns.
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Affiliation(s)
- Abigail K. Albutt
- School of PsychologyUniversity of LeedsLeedsUK
- Bradford Institute for Health ResearchBradford Royal InfirmaryBradfordUK
| | - Jane K. O'Hara
- School of MedicineUniversity of LeedsLeedsUK
- Bradford Institute for Health ResearchBradford Royal InfirmaryBradfordUK
| | | | | | - Rebecca J. Lawton
- School of PsychologyUniversity of LeedsLeedsUK
- Bradford Institute for Health ResearchBradford Royal InfirmaryBradfordUK
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18
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Mitter N, Worrall EA, Robinson KE, Li P, Jain RG, Taochy C, Fletcher SJ, Carroll BJ, Lu GQM, Xu ZP. Clay nanosheets for topical delivery of RNAi for sustained protection against plant viruses. Nat Plants 2017; 3:16207. [PMID: 28067898 DOI: 10.1038/nplants.2016.207] [Citation(s) in RCA: 379] [Impact Index Per Article: 54.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 11/24/2016] [Indexed: 05/19/2023]
Abstract
Topical application of pathogen-specific double-stranded RNA (dsRNA) for virus resistance in plants represents an attractive alternative to transgenic RNA interference (RNAi). However, the instability of naked dsRNA sprayed on plants has been a major challenge towards its practical application. We demonstrate that dsRNA can be loaded on designer, non-toxic, degradable, layered double hydroxide (LDH) clay nanosheets. Once loaded on LDH, the dsRNA does not wash off, shows sustained release and can be detected on sprayed leaves even 30 days after application. We provide evidence for the degradation of LDH, dsRNA uptake in plant cells and silencing of homologous RNA on topical application. Significantly, a single spray of dsRNA loaded on LDH (BioClay) afforded virus protection for at least 20 days when challenged on sprayed and newly emerged unsprayed leaves. This innovation translates nanotechnology developed for delivery of RNAi for human therapeutics to use in crop protection as an environmentally sustainable and easy to adopt topical spray.
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Affiliation(s)
- Neena Mitter
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Elizabeth A Worrall
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Karl E Robinson
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Peng Li
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Ritesh G Jain
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Christelle Taochy
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Stephen J Fletcher
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - Bernard J Carroll
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
| | - G Q Max Lu
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
- University of Surrey, Guildford GU2 7XH, UK
| | - Zhi Ping Xu
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
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Fletcher SJ, Shrestha A, Peters JR, Carroll BJ, Srinivasan R, Pappu HR, Mitter N. The Tomato Spotted Wilt Virus Genome Is Processed Differentially in its Plant Host Arachis hypogaea and its Thrips Vector Frankliniella fusca. Front Plant Sci 2016; 7:1349. [PMID: 27656190 PMCID: PMC5013717 DOI: 10.3389/fpls.2016.01349] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 08/22/2016] [Indexed: 06/06/2023]
Abstract
Thrips-transmitted tospoviruses are economically important viruses affecting a wide range of field and horticultural crops worldwide. Tomato spotted wilt virus (TSWV) is the type member of the Tospovirus genus with a broad host range of more than 900 plant species. Interactions between these viruses and their plant hosts and insect vectors via RNAi pathways are likely a key determinant of pathogenicity. The current investigation, for the first time, compares biogenesis of small RNAs between the plant host and insect vector in the presence or absence of TSWV. Unique viral small interfering RNA (vsiRNA) profiles are evident for Arachis hypogaea (peanut) and Frankliniella fusca (thrips vector) following infection with TSWV. Differences between vsiRNA profiles for these plant and insect species, such as the relative abundance of 21 and 22 nt vsiRNAs and locations of alignment hotspots, reflect the diverse siRNA biosynthesis pathways of their respective kingdoms. The presence of unique vsiRNAs in F. fusca samples indicates that vsiRNA generation takes place within the thrips, and not solely through uptake via feeding on vsiRNAs produced in infected A. hypogaea. The study also shows key vsiRNA profile differences for TSWV among plant families, which are evident in the case of A. hypogaea, a legume, and members of Solanaceae (S. lycopersicum and Nicotiana benthamiana). Distinctively, overall small RNA (sRNA) biogenesis in A. hypogaea is markedly affected with an absence of the 24 nt sRNAs in TSWV-infected plants, possibly leading to wide-spread molecular and phenotypic perturbations specific to this species. These findings add significant information on the host-virus-vector interaction in terms of RNAi pathways and may lead to better crop and vector specific control strategies.
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Affiliation(s)
- Stephen J. Fletcher
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. LuciaQLD, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. LuciaQLD, Australia
| | - Anita Shrestha
- Department of Entomology, College of Agricultural and Environmental Sciences, University of Georgia, TiftonGA, USA
| | - Jonathan R. Peters
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. LuciaQLD, Australia
| | - Bernard J. Carroll
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. LuciaQLD, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. LuciaQLD, Australia
| | - Rajagopalbabu Srinivasan
- Department of Entomology, College of Agricultural and Environmental Sciences, University of Georgia, TiftonGA, USA
| | - Hanu R. Pappu
- Department of Plant Pathology, Washington State University, PullmanWA, USA
| | - Neena Mitter
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. LuciaQLD, Australia
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Hooper L, Abdelhamid A, Attreed NJ, Campbell WW, Channell AM, Chassagne P, Culp KR, Fletcher SJ, Fortes MB, Fuller N, Gaspar PM, Gilbert DJ, Heathcote AC, Kafri MW, Kajii F, Lindner G, Mack GW, Mentes JC, Merlani P, Needham RA, Olde Rikkert MGM, Perren A, Powers J, Ranson SC, Ritz P, Rowat AM, Sjöstrand F, Smith AC, Stookey JJD, Stotts NA, Thomas DR, Vivanti A, Wakefield BJ, Waldréus N, Walsh NP, Ward S, Potter JF, Hunter P. Clinical symptoms, signs and tests for identification of impending and current water-loss dehydration in older people. Cochrane Database Syst Rev 2015; 2015:CD009647. [PMID: 25924806 PMCID: PMC7097739 DOI: 10.1002/14651858.cd009647.pub2] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND There is evidence that water-loss dehydration is common in older people and associated with many causes of morbidity and mortality. However, it is unclear what clinical symptoms, signs and tests may be used to identify early dehydration in older people, so that support can be mobilised to improve hydration before health and well-being are compromised. OBJECTIVES To determine the diagnostic accuracy of state (one time), minimally invasive clinical symptoms, signs and tests to be used as screening tests for detecting water-loss dehydration in older people by systematically reviewing studies that have measured a reference standard and at least one index test in people aged 65 years and over. Water-loss dehydration was defined primarily as including everyone with either impending or current water-loss dehydration (including all those with serum osmolality ≥ 295 mOsm/kg as being dehydrated). SEARCH METHODS Structured search strategies were developed for MEDLINE (OvidSP), EMBASE (OvidSP), CINAHL, LILACS, DARE and HTA databases (The Cochrane Library), and the International Clinical Trials Registry Platform (ICTRP). Reference lists of included studies and identified relevant reviews were checked. Authors of included studies were contacted for details of further studies. SELECTION CRITERIA Titles and abstracts were scanned and all potentially relevant studies obtained in full text. Inclusion of full text studies was assessed independently in duplicate, and disagreements resolved by a third author. We wrote to authors of all studies that appeared to have collected data on at least one reference standard and at least one index test, and in at least 10 people aged ≥ 65 years, even where no comparative analysis has been published, requesting original dataset so we could create 2 x 2 tables. DATA COLLECTION AND ANALYSIS Diagnostic accuracy of each test was assessed against the best available reference standard for water-loss dehydration (serum or plasma osmolality cut-off ≥ 295 mOsm/kg, serum osmolarity or weight change) within each study. For each index test study data were presented in forest plots of sensitivity and specificity. The primary target condition was water-loss dehydration (including either impending or current water-loss dehydration). Secondary target conditions were intended as current (> 300 mOsm/kg) and impending (295 to 300 mOsm/kg) water-loss dehydration, but restricted to current dehydration in the final review.We conducted bivariate random-effects meta-analyses (Stata/IC, StataCorp) for index tests where there were at least four studies and study datasets could be pooled to construct sensitivity and specificity summary estimates. We assigned the same approach for index tests with continuous outcome data for each of three pre-specified cut-off points investigated.Pre-set minimum sensitivity of a useful test was 60%, minimum specificity 75%. As pre-specifying three cut-offs for each continuous test may have led to missing a cut-off with useful sensitivity and specificity, we conducted post-hoc exploratory analyses to create receiver operating characteristic (ROC) curves where there appeared some possibility of a useful cut-off missed by the original three. These analyses enabled assessment of which tests may be worth assessing in further research. A further exploratory analysis assessed the value of combining the best two index tests where each had some individual predictive ability. MAIN RESULTS There were few published studies of the diagnostic accuracy of state (one time), minimally invasive clinical symptoms, signs or tests to be used as screening tests for detecting water-loss dehydration in older people. Therefore, to complete this review we sought, analysed and included raw datasets that included a reference standard and an index test in people aged ≥ 65 years.We included three studies with published diagnostic accuracy data and a further 21 studies provided datasets that we analysed. We assessed 67 tests (at three cut-offs for each continuous outcome) for diagnostic accuracy of water-loss dehydration (primary target condition) and of current dehydration (secondary target condition).Only three tests showed any ability to diagnose water-loss dehydration (including both impending and current water-loss dehydration) as stand-alone tests: expressing fatigue (sensitivity 0.71 (95% CI 0.29 to 0.96), specificity 0.75 (95% CI 0.63 to 0.85), in one study with 71 participants, but two additional studies had lower sensitivity); missing drinks between meals (sensitivity 1.00 (95% CI 0.59 to 1.00), specificity 0.77 (95% CI 0.64 to 0.86), in one study with 71 participants) and BIA resistance at 50 kHz (sensitivities 1.00 (95% CI 0.48 to 1.00) and 0.71 (95% CI 0.44 to 0.90) and specificities of 1.00 (95% CI 0.69 to 1.00) and 0.80 (95% CI 0.28 to 0.99) in 15 and 22 people respectively for two studies, but with sensitivities of 0.54 (95% CI 0.25 to 0.81) and 0.69 (95% CI 0.56 to 0.79) and specificities of 0.50 (95% CI 0.16 to 0.84) and 0.19 (95% CI 0.17 to 0.21) in 21 and 1947 people respectively in two other studies). In post-hoc ROC plots drinks intake, urine osmolality and axillial moisture also showed limited diagnostic accuracy. No test was consistently useful in more than one study.Combining two tests so that an individual both missed some drinks between meals and expressed fatigue was sensitive at 0.71 (95% CI 0.29 to 0.96) and specific at 0.92 (95% CI 0.83 to 0.97).There was sufficient evidence to suggest that several stand-alone tests often used to assess dehydration in older people (including fluid intake, urine specific gravity, urine colour, urine volume, heart rate, dry mouth, feeling thirsty and BIA assessment of intracellular water or extracellular water) are not useful, and should not be relied on individually as ways of assessing presence or absence of dehydration in older people.No tests were found consistently useful in diagnosing current water-loss dehydration. AUTHORS' CONCLUSIONS There is limited evidence of the diagnostic utility of any individual clinical symptom, sign or test or combination of tests to indicate water-loss dehydration in older people. Individual tests should not be used in this population to indicate dehydration; they miss a high proportion of people with dehydration, and wrongly label those who are adequately hydrated.Promising tests identified by this review need to be further assessed, as do new methods in development. Combining several tests may improve diagnostic accuracy.
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Abstract
Quantitative real-time PCR (qPCR) is a mature technology that can be used to accurately quantify the number of copies of a target nucleic acid in a sample. Here, we describe a method for using this technology to determine the copy number of a transgene stably integrated into a plant's genome and to ascertain the level of transgene expression.
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Affiliation(s)
- Stephen J Fletcher
- Chemistry and Molecular Biosciences, The School of Biological Sciences, University of Queensland, St Lucia Campus, Brisbane, QLD, 4072, Australia,
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Medici M, Porcu E, Pistis G, Teumer A, Brown SJ, Jensen RA, Rawal R, Roef GL, Plantinga TS, Vermeulen SH, Lahti J, Simmonds MJ, Husemoen LLN, Freathy RM, Shields BM, Pietzner D, Nagy R, Broer L, Chaker L, Korevaar TIM, Plia MG, Sala C, Völker U, Richards JB, Sweep FC, Gieger C, Corre T, Kajantie E, Thuesen B, Taes YE, Visser WE, Hattersley AT, Kratzsch J, Hamilton A, Li W, Homuth G, Lobina M, Mariotti S, Soranzo N, Cocca M, Nauck M, Spielhagen C, Ross A, Arnold A, van de Bunt M, Liyanarachchi S, Heier M, Grabe HJ, Masciullo C, Galesloot TE, Lim EM, Reischl E, Leedman PJ, Lai S, Delitala A, Bremner AP, Philips DIW, Beilby JP, Mulas A, Vocale M, Abecasis G, Forsen T, James A, Widen E, Hui J, Prokisch H, Rietzschel EE, Palotie A, Feddema P, Fletcher SJ, Schramm K, Rotter JI, Kluttig A, Radke D, Traglia M, Surdulescu GL, He H, Franklyn JA, Tiller D, Vaidya B, de Meyer T, Jørgensen T, Eriksson JG, O'Leary PC, Wichmann E, Hermus AR, Psaty BM, Ittermann T, Hofman A, Bosi E, Schlessinger D, Wallaschofski H, Pirastu N, Aulchenko YS, de la Chapelle A, Netea-Maier RT, Gough SCL, Meyer zu Schwabedissen H, Frayling TM, Kaufman JM, Linneberg A, Räikkönen K, Smit JWA, Kiemeney LA, Rivadeneira F, Uitterlinden AG, Walsh JP, Meisinger C, den Heijer M, Visser TJ, Spector TD, Wilson SG, Völzke H, Cappola A, Toniolo D, Sanna S, Naitza S, Peeters RP. Identification of novel genetic Loci associated with thyroid peroxidase antibodies and clinical thyroid disease. PLoS Genet 2014; 10:e1004123. [PMID: 24586183 PMCID: PMC3937134 DOI: 10.1371/journal.pgen.1004123] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [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] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 12/03/2013] [Indexed: 12/14/2022] Open
Abstract
Autoimmune thyroid diseases (AITD) are common, affecting 2-5% of the general population. Individuals with positive thyroid peroxidase antibodies (TPOAbs) have an increased risk of autoimmune hypothyroidism (Hashimoto's thyroiditis), as well as autoimmune hyperthyroidism (Graves' disease). As the possible causative genes of TPOAbs and AITD remain largely unknown, we performed GWAS meta-analyses in 18,297 individuals for TPOAb-positivity (1769 TPOAb-positives and 16,528 TPOAb-negatives) and in 12,353 individuals for TPOAb serum levels, with replication in 8,990 individuals. Significant associations (P<5×10(-8)) were detected at TPO-rs11675434, ATXN2-rs653178, and BACH2-rs10944479 for TPOAb-positivity, and at TPO-rs11675434, MAGI3-rs1230666, and KALRN-rs2010099 for TPOAb levels. Individual and combined effects (genetic risk scores) of these variants on (subclinical) hypo- and hyperthyroidism, goiter and thyroid cancer were studied. Individuals with a high genetic risk score had, besides an increased risk of TPOAb-positivity (OR: 2.18, 95% CI 1.68-2.81, P = 8.1×10(-8)), a higher risk of increased thyroid-stimulating hormone levels (OR: 1.51, 95% CI 1.26-1.82, P = 2.9×10(-6)), as well as a decreased risk of goiter (OR: 0.77, 95% CI 0.66-0.89, P = 6.5×10(-4)). The MAGI3 and BACH2 variants were associated with an increased risk of hyperthyroidism, which was replicated in an independent cohort of patients with Graves' disease (OR: 1.37, 95% CI 1.22-1.54, P = 1.2×10(-7) and OR: 1.25, 95% CI 1.12-1.39, P = 6.2×10(-5)). The MAGI3 variant was also associated with an increased risk of hypothyroidism (OR: 1.57, 95% CI 1.18-2.10, P = 1.9×10(-3)). This first GWAS meta-analysis for TPOAbs identified five newly associated loci, three of which were also associated with clinical thyroid disease. With these markers we identified a large subgroup in the general population with a substantially increased risk of TPOAbs. The results provide insight into why individuals with thyroid autoimmunity do or do not eventually develop thyroid disease, and these markers may therefore predict which TPOAb-positives are particularly at risk of developing clinical thyroid dysfunction.
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Affiliation(s)
- Marco Medici
- Department of Internal Medicine, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
- * E-mail:
| | - Eleonora Porcu
- Istituto di Ricerca Genetica e Biomedica (IRGB), Consiglio Nazionale delle Ricerche, c/o Cittadella Universitaria di Monserrato, Monserrato, Cagliari, Italy
- Dipartimento di Scienze Biomediche, Universita di Sassari, Sassari, Italy
| | - Giorgio Pistis
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Alexander Teumer
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine and Ernst-Moritz-Arndt-University Greifswald, Greifswald, Germany
| | - Suzanne J. Brown
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
| | - Richard A. Jensen
- Cardiovascular Health Research Unit, Departments of Medicine, Epidemiology and Health Services, University of Washington, Seattle, Washington, United States of America
| | - Rajesh Rawal
- Institute for Genetic Epidemiology, Helmholtz Zentrum Munich, Munich/Neuherberg, Germany
| | - Greet L. Roef
- Department of Endocrinology and Internal Medicine, University Hospital Ghent and Faculty of Medicine, Ghent University, Ghent, Belgium
| | - Theo S. Plantinga
- Internal Medicine, Division of Endocrinology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Sita H. Vermeulen
- Department for Health Evidence, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Jari Lahti
- Institute of Behavioural Sciences, University of Helsinki, Helsinki, Finland
| | - Matthew J. Simmonds
- Oxford Centre for Diabetes, Endocrinology and Metabolism and NIHR Oxford Biomedical Research Centre, Oxford, UK Churchill Hospital, Headington, Oxford, United Kingdom
| | - Lise Lotte N. Husemoen
- Research Centre for Prevention and Health, Glostrup University Hospital, the Capital Region of Denmark, Glostrup, Denmark
| | - Rachel M. Freathy
- Genetics of Complex Traits, University of Exeter Medical School, University of Exeter, Exeter, United Kingdom
| | - Beverley M. Shields
- Peninsula NIHR Clinical Research Facility, University of Exeter Medical School, University of Exeter, Exeter, United Kingdom
| | - Diana Pietzner
- Institute of Medical Epidemiology, Biostatistics, and Informatics, Martin-Luther-University Halle-Wittenberg, Halle, Germany
| | - Rebecca Nagy
- Comprehensive Cancer Center, Ohio State University, Columbus, Ohio, United States of America
| | - Linda Broer
- Department of Epidemiology, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Layal Chaker
- Department of Internal Medicine, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Tim I. M. Korevaar
- Department of Internal Medicine, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Maria Grazia Plia
- Istituto di Ricerca Genetica e Biomedica (IRGB), Consiglio Nazionale delle Ricerche, c/o Cittadella Universitaria di Monserrato, Monserrato, Cagliari, Italy
| | - Cinzia Sala
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Uwe Völker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine and Ernst-Moritz-Arndt-University Greifswald, Greifswald, Germany
| | - J. Brent Richards
- Departments of Medicine, Human Genetics, Epidemiology and Biostatistics, Lady Davis Institute, McGill University, Montreal, Canada
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
| | - Fred C. Sweep
- Department for Health Evidence, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Christian Gieger
- Institute for Genetic Epidemiology, Helmholtz Zentrum Munich, Munich/Neuherberg, Germany
| | - Tanguy Corre
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Eero Kajantie
- National Institute for Health and Welfare, Helsinki, Finland
- Hospital for Children and Adolescents, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland
| | - Betina Thuesen
- Research Centre for Prevention and Health, Glostrup University Hospital, the Capital Region of Denmark, Glostrup, Denmark
| | - Youri E. Taes
- Department of Endocrinology and Internal Medicine, University Hospital Ghent and Faculty of Medicine, Ghent University, Ghent, Belgium
| | - W. Edward Visser
- Department of Internal Medicine, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Andrew T. Hattersley
- Peninsula NIHR Clinical Research Facility, University of Exeter Medical School, University of Exeter, Exeter, United Kingdom
| | - Jürgen Kratzsch
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Alexander Hamilton
- Oxford Centre for Diabetes, Endocrinology and Metabolism and NIHR Oxford Biomedical Research Centre, Oxford, UK Churchill Hospital, Headington, Oxford, United Kingdom
| | - Wei Li
- Comprehensive Cancer Center, Ohio State University, Columbus, Ohio, United States of America
| | - Georg Homuth
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine and Ernst-Moritz-Arndt-University Greifswald, Greifswald, Germany
| | - Monia Lobina
- Istituto di Ricerca Genetica e Biomedica (IRGB), Consiglio Nazionale delle Ricerche, c/o Cittadella Universitaria di Monserrato, Monserrato, Cagliari, Italy
| | - Stefano Mariotti
- Dipartimento di Scienze Biomediche, Universita di Sassari, Sassari, Italy
| | | | - Massimiliano Cocca
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Matthias Nauck
- Institute of Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Christin Spielhagen
- Institute of Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Alec Ross
- Department for Health Evidence, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Alice Arnold
- Department of Biostatistics, University of Washington, Seattle, Washington, United States of America
| | - Martijn van de Bunt
- Oxford Centre for Diabetes, Endocrinology and Metabolism and NIHR Oxford Biomedical Research Centre, Oxford, UK Churchill Hospital, Headington, Oxford, United Kingdom
| | - Sandya Liyanarachchi
- Comprehensive Cancer Center, Ohio State University, Columbus, Ohio, United States of America
| | - Margit Heier
- Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Institute of Epidemiology II, Neuherberg, Germany
| | - Hans Jörgen Grabe
- Department of Psychiatry and Psychotherapy, University Medicine Greifswald, HELIOS Hospital Stralsund, Greifswald, Germany
| | - Corrado Masciullo
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Tessel E. Galesloot
- Department for Health Evidence, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Ee M. Lim
- Pathwest Laboratory Medicine WA, Nedlands, Western Australia, Australia
| | - Eva Reischl
- Research Unit of Molecular Epidemiology Helmholtz Zentrum München - German Research Center for Environmental Health, Neuherberg, Germany
| | - Peter J. Leedman
- School of Medicine and Pharmacology, the University of Western Australia, Crawley, Western Australia, Australia
- UWA Centre for Medical Research, Western Australian Institute for Medical Research, Perth, Western Australia, Australia
| | - Sandra Lai
- Istituto di Ricerca Genetica e Biomedica (IRGB), Consiglio Nazionale delle Ricerche, c/o Cittadella Universitaria di Monserrato, Monserrato, Cagliari, Italy
| | | | - Alexandra P. Bremner
- School of Population Health, University of Western Australia, Nedlands, Western Australia, Australia
| | - David I. W. Philips
- MRC Lifecourse Epidemiology Unit, Southampton General Hospital, Southampton, United Kingdom
| | - John P. Beilby
- Pathwest Laboratory Medicine WA, Nedlands, Western Australia, Australia
- School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia
| | - Antonella Mulas
- Istituto di Ricerca Genetica e Biomedica (IRGB), Consiglio Nazionale delle Ricerche, c/o Cittadella Universitaria di Monserrato, Monserrato, Cagliari, Italy
| | - Matteo Vocale
- High Performance Computing and Network, CRS4, Parco Tecnologico della Sardegna, Pula, Italy
| | - Goncalo Abecasis
- Center for Statistical Genetics, Department of Biostatistics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Tom Forsen
- Department of Chronic Disease Prevention, National Institute for Health and Welfare, Helsinki, Finland
- Vaasa Health Care Centre, Diabetes Unit, Vaasa, Finland
| | - Alan James
- School of Medicine and Pharmacology, the University of Western Australia, Crawley, Western Australia, Australia
- Department of Respiratory Medicine, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
| | - Elisabeth Widen
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Jennie Hui
- Pathwest Laboratory Medicine WA, Nedlands, Western Australia, Australia
| | - Holger Prokisch
- Institute of Human Genetics, Helmholtz Zentrum Munich, Munich, Germany
- Institute of Human Genetics, Technische Universität München, Munich, Germany
| | - Ernst E. Rietzschel
- Department of Cardiology and Internal Medicine, University Hospital Ghent and Faculty of Medicine, Ghent University, Ghent, Belgium
| | - Aarno Palotie
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge, United Kingdom
- Department of Medical Genetics, University of Helsinki and University Central Hospital, Helsinki, Finland
| | | | | | - Katharina Schramm
- Institute of Human Genetics, Helmholtz Zentrum Munich, Munich, Germany
| | - Jerome I. Rotter
- Institute for Translational Genomics and Population Sciences, Los Angeles Biomedical Research Institute, Torrance, California, United States of America
- Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, California, United States of America
| | - Alexander Kluttig
- Institute of Medical Epidemiology, Biostatistics, and Informatics, Martin-Luther-University Halle-Wittenberg, Halle, Germany
| | - Dörte Radke
- Institute for Community Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Michela Traglia
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Gabriela L. Surdulescu
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
| | - Huiling He
- Comprehensive Cancer Center, Ohio State University, Columbus, Ohio, United States of America
| | - Jayne A. Franklyn
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, Univeristy of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Daniel Tiller
- Institute of Medical Epidemiology, Biostatistics, and Informatics, Martin-Luther-University Halle-Wittenberg, Halle, Germany
| | - Bijay Vaidya
- Diabetes, Endocrinology and Vascular Health Centre, Royal Devon and Exeter NHS Foundation Trust, Exeter, United Kingdom
| | - Tim de Meyer
- BIOBIX Lab. for Bioinformatics and Computational Genomics, Dept. of Mathematical Modelling, Statistics and Bioinformatics. Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Torben Jørgensen
- Research Centre for Prevention and Health, Glostrup University Hospital, the Capital Region of Denmark, Glostrup, Denmark
- Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark
| | - Johan G. Eriksson
- National Institute for Health and Welfare, Helsinki, Finland
- Department of General Practice and Primary Health Care, University of Helsinki, Helsinki, Finland
- Helsinki University Central Hospital, Unit of General Practice, Helsinki, Finland
- Folkhalsan Research Centre, Helsinki, Finland
- Vasa Central Hospital, Vasa, Finland
| | - Peter C. O'Leary
- School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia
- Curtin Health Innovation Research Institute, Curtin University of Technology, Bentley, Western Australia, Australia
| | - Eric Wichmann
- Institute of Epidemiology I, Helmholtz Zentrum Munich, Munich, Germany
| | - Ad R. Hermus
- Internal Medicine, Division of Endocrinology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Bruce M. Psaty
- Cardiovascular Health Research Unit, Departments of Medicine, Epidemiology and Health Services, University of Washington, Seattle, Washington, United States of America
- Group Health Research Institute, Group Health Cooperative, Seattle, Washington, United States of America
| | - Till Ittermann
- Institute for Community Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Albert Hofman
- Department of Epidemiology, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Emanuele Bosi
- Department of Internal Medicine, Diabetes & Endocrinology Unit, San Raffaele Scientific Institute and Vita-Salute San Raffaele University, Milan, Italy
| | - David Schlessinger
- Laboratory of Genetics, National Institute on Aging, Baltimore, Maryland, United States of America
| | - Henri Wallaschofski
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Leipzig, Germany
| | - Nicola Pirastu
- Institute for Maternal and Child Health - IRCCS “Burlo Garofolo”, Trieste, Italy
- University of Trieste, Trieste, Italy
| | - Yurii S. Aulchenko
- Department of Epidemiology, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Albert de la Chapelle
- Comprehensive Cancer Center, Ohio State University, Columbus, Ohio, United States of America
| | - Romana T. Netea-Maier
- Internal Medicine, Division of Endocrinology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Stephen C. L. Gough
- Oxford Centre for Diabetes, Endocrinology and Metabolism and NIHR Oxford Biomedical Research Centre, Oxford, UK Churchill Hospital, Headington, Oxford, United Kingdom
| | | | - Timothy M. Frayling
- Genetics of Complex Traits, University of Exeter Medical School, University of Exeter, Exeter, United Kingdom
| | - Jean-Marc Kaufman
- Department of Endocrinology and Internal Medicine, University Hospital Ghent and Faculty of Medicine, Ghent University, Ghent, Belgium
| | - Allan Linneberg
- Research Centre for Prevention and Health, Glostrup University Hospital, the Capital Region of Denmark, Glostrup, Denmark
| | - Katri Räikkönen
- Institute of Behavioural Sciences, University of Helsinki, Helsinki, Finland
| | - Johannes W. A. Smit
- Internal Medicine, Division of Endocrinology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Lambertus A. Kiemeney
- Department for Health Evidence, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Fernando Rivadeneira
- Department of Internal Medicine, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
- Netherlands Consortium for Healthy Aging, Netherlands Genomics Initiative, Leiden, The Netherlands
| | - André G. Uitterlinden
- Department of Internal Medicine, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
- Netherlands Consortium for Healthy Aging, Netherlands Genomics Initiative, Leiden, The Netherlands
| | - John P. Walsh
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
- School of Medicine and Pharmacology, the University of Western Australia, Crawley, Western Australia, Australia
| | - Christa Meisinger
- Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Institute of Epidemiology II, Neuherberg, Germany
| | - Martin den Heijer
- Department of Internal Medicine, VU Medical Center, Amsterdam, The Netherlands
| | - Theo J. Visser
- Department of Internal Medicine, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Timothy D. Spector
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
| | - Scott G. Wilson
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
- School of Medicine and Pharmacology, the University of Western Australia, Crawley, Western Australia, Australia
- Department of Twin Research and Genetic Epidemiology, King's College London, London, United Kingdom
| | - Henry Völzke
- Institute for Community Medicine, University Medicine Greifswald, Greifswald, Germany
| | - Anne Cappola
- Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Daniela Toniolo
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
- Institute of Molecular Genetics-CNR, Pavia, Italy
| | - Serena Sanna
- Istituto di Ricerca Genetica e Biomedica (IRGB), Consiglio Nazionale delle Ricerche, c/o Cittadella Universitaria di Monserrato, Monserrato, Cagliari, Italy
| | - Silvia Naitza
- Istituto di Ricerca Genetica e Biomedica (IRGB), Consiglio Nazionale delle Ricerche, c/o Cittadella Universitaria di Monserrato, Monserrato, Cagliari, Italy
| | - Robin P. Peeters
- Department of Internal Medicine, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
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Kalyan JP, Rosbergen M, Pal N, Sargen K, Fletcher SJ, Nunn DL, Clark A, Williams MR, Lewis MPN. Randomized clinical trial of fluid and salt restriction compared with a controlled liberal regimen in elective gastrointestinal surgery. Br J Surg 2014; 100:1739-46. [PMID: 24227358 PMCID: PMC4312881 DOI: 10.1002/bjs.9301] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/09/2013] [Indexed: 12/14/2022]
Abstract
Background Excessive intravenous fluid prescription may play a causal role in postoperative complications following major gastrointestinal resectional surgery. The aim of this study was to investigate whether fluid and salt restriction would decrease postoperative complications compared with a more modern controlled liberal regimen. Methods In this observer-blinded single-site randomized clinical trial consecutive patients undergoing major gastrointestinal resectional surgery were randomized to receive either a liberal control fluid regimen or a restricted fluid and salt regimen. The primary outcome was postoperative complications of grade II and above (moderate to severe). Results Some 240 patients (194 colorectal resections and 46 oesophagogastric resections) were enrolled in the study; 121 patients were randomized to the restricted regimen and 119 to the control (liberal) regimen. During surgery the control group received a median (interquartile range) fluid volume of 2033 (1576–2500) ml and sodium input of 282 (213–339) mmol, compared with 1000 (690–1500) ml and 142 (93–218) mmol respectively in the restricted group. There was no significant difference in major complication rate between groups (38·0 and 39·0 per cent respectively). Median (range) hospital stay was 8 (3–101) days in the controls and 8 (range 3–76) days among those who received restricted fluids. There were four in-hospital deaths in the control group and two in the restricted group. Substantial differences in weight change, serum sodium, osmolality and urine : serum osmolality ratio were observed between the groups. Conclusion There were no significant differences in major complication rates, length of stay and in-hospital deaths when fluid restriction was used compared with a more liberal regimen. Registration number: ISRCTN39295230 (http://www.controlled-trials.com).
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Affiliation(s)
- J P Kalyan
- Department of Surgery, Norfolk and Norwich University HospitalNorwich, UK
- Correspondence to: Mr J. P. Kalyan, Department of General Surgery, Norfolk and Norwich University Hospital NHS Foundation Trust, Colney Lane, Norwich NR4 7UY, UK (e-mail: )
| | - M Rosbergen
- Department of Surgery, Norfolk and Norwich University HospitalNorwich, UK
| | - N Pal
- Department of Surgery, Norfolk and Norwich University HospitalNorwich, UK
| | - K Sargen
- Department of Surgery, Norfolk and Norwich University HospitalNorwich, UK
| | - S J Fletcher
- Department of Anaesthetics and Intensive Care, Norfolk and Norwich University HospitalNorwich, UK
| | - D L Nunn
- Department of Anaesthetics and Intensive Care, Norfolk and Norwich University HospitalNorwich, UK
| | - A Clark
- School of Medicine (Biostatistics), University of East AngliaNorwich, UK
| | - M R Williams
- Department of Biology, University of East AngliaNorwich, UK
| | - M P N Lewis
- Department of Surgery, Norfolk and Norwich University HospitalNorwich, UK
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Hooper L, Attreed NJ, Campbell WW, Channell AM, Chassagne P, Culp KR, Fletcher SJ, Fuller N, Gaspar PM, Gilbert DJ, Heathcote AC, Lindner G, Mack GW, Mentes JC, Needham RA, Olde Rikkert MGM, Ranson SC, Ritz P, Rowat AM, Smith AC, Stookey JJD, Thomas DR, Wakefield BJ, Ward S, Potter JF, Hunter PR. Clinical and physical signs for identification of impending and current water-loss dehydration in older people. THE COCHRANE DATABASE OF SYSTEMATIC REVIEWS 2012. [DOI: 10.1002/14651858.cd009647] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Pathmanathan N, Fletcher SJ. Drotrecogin Alfa (Activated) in Severe Sepsis: A Single-Centre Series of 110 Patients. J Intensive Care Soc 2011. [DOI: 10.1177/175114371101200304] [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] [Indexed: 11/17/2022] Open
Abstract
We present our experience with drotrecogin alfa (activated) in 110 patients. Data were collected on diagnosis, acuity, complications and outcomes. Crude ICU and hospital mortality was high at 47.3 and 55.5% respectively (hospital SMR = 1.02). Our patients appeared to be sicker than in other published series (mean number of organ failures = 4). The rate of serious bleeding events was comparable to the PROWESS trial. Usage fell during the study period from 37 patients in 2005 to 14 patients in 2008 and is likely to reflect uncertainty over the risk-benefit profile.
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Affiliation(s)
| | - Stephen J Fletcher
- Director of Intensive Care, Intensive Care Unit, Bradford Teaching Hospitals NHSFT
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26
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Panicker V, Wilson SG, Walsh JP, Richards JB, Brown SJ, Beilby JP, Bremner AP, Surdulescu GL, Qweitin E, Gillham-Nasenya I, Soranzo N, Lim EM, Fletcher SJ, Spector TD. A locus on chromosome 1p36 is associated with thyrotropin and thyroid function as identified by genome-wide association study. Am J Hum Genet 2010; 87:430-5. [PMID: 20826269 DOI: 10.1016/j.ajhg.2010.08.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Revised: 07/21/2010] [Accepted: 08/13/2010] [Indexed: 10/19/2022] Open
Abstract
Thyroid hormones are key regulators of cellular growth, development, and metabolism, and thyroid disorders are a common cause of ill health in the community. Circulating concentrations of thyrotropin (TSH), thyroxine (T4) and triiodothyronine (T3) have a strong heritable component and are thought to be under polygenic control, but the genes responsible are mostly unknown. In order to identify genetic loci associated with these metabolic phenotypes, we performed a genome-wide association study of 2,120,505 SNPs in 2014 female twins from the TwinsUK study and found a significant association between rs10917469 on chromosome 1p36.13 and serum TSH (p = 3.2 × 10(-8)). The association of rs10917469 with serum TSH was replicated (p = 2.0 × 10(-4)) in an independent community-based sample of 1154 participants in the Busselton Health Study. This SNP is located near CAPZB, which might be a regulator of TSH secretion and thus of pituitary-thyroid axis function. Twenty-nine percent of white individuals carry the variant, and the difference in mean TSH concentrations between wild-type individuals and those homozygous for the minor G allele was 0.5 mU/l, which is likely to be clinically relevant. We also provide evidence of suggestive association (p < 5.0 × 10(-6)) of other SNPs with serum TSH, free T4, and free T3 concentrations, and these SNPs might be good targets for further studies. These results advance understanding of the genetic basis of pituitary-thyroid axis function and metabolic regulation.
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Fletcher SJ, Phillips LW, Milligan AS, Rodda SJ. Toward specific detection of Dengue virus serotypes using a novel modular biosensor. Biosens Bioelectron 2010; 26:1696-700. [PMID: 20692150 DOI: 10.1016/j.bios.2010.07.046] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Revised: 07/08/2010] [Accepted: 07/13/2010] [Indexed: 10/19/2022]
Abstract
Arthropod-borne diseases affect a significant portion of the world's population. Dengue fever, a viral disease carried by the Aedes aegypti mosquito, is one of the most wide-spread, with many fatalities evident each year. To date, Dengue viral diagnostic technologies have been too complex, time-consuming and expensive to be widely deployed, particularly in developing countries where the disease is most prevalent. Here we demonstrate a modular biosensor that is able to rapidly identify sequences associated with the Dengue virus genome. The biosensor consists of an oligonucleotide linker module, an aptamer/restriction endonuclease signal transducer and a fluorescent signalling molecule. The linker molecule has a simple stem/loop conformation and comprises a target-complementary moiety within the loop and a trigger moiety within the stem. When bound to the target nucleic acid, the trigger strand of the denatured stem can bind to the aptamer within the signal transducer. Disruption of the aptamer releases the restriction endonuclease EcoRI from aptamer-mediated inhibition. Active EcoRI is able to rapidly cleave multiple signalling molecules to generate a detectable signal. The biosensor was able to detect sequences derived from each of the four Dengue virus serotypes with a great degree of specificity. Along with sequences specific to each serotype, a pan-Dengue sequence, common to all serotypes, was also detected.
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Affiliation(s)
- Stephen J Fletcher
- Lifeprint Australia Pty Ltd, Plant Genomics Centre, Hartley Grove, Urrbrae 5064, Australia.
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Glover GW, Fletcher SJ. Assessing the performance of the Whisperflow continuous positive airway pressure generator: a bench study. Br J Anaesth 2009; 102:875-81. [PMID: 19380311 DOI: 10.1093/bja/aep077] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND There are few data describing the performance of the Whisperflow continuous positive airway pressure (CPAP) generator. METHODS (i) (a) A static test of 11 Whisperflow devices examining maximum flow generation with no load and with 2.5, 5, 7.5, 10, 15, and 20 cm H2O valve loading, at varying Fi(O2). (b) CPAP valves (Accu-peep(R), Vital Signs, Totowa, NJ, USA) were tested by measuring mean upstream pressure at varying flows in five valves (2.5, 5, 7.5, 10, 15, and 20 cm H2O). (ii) We measured the mean and minimum inspiratory mask pressure generated by a representative Whisperflow device in a model of spontaneous respiration. Measurements were made with combinations of Fi(O2), ventilatory frequency, tidal volume, and valve loading similar to those encountered in clinical practice. RESULTS (i) (a) The flow generated by the Whisperflow valves decreases with increasing valve load and increasing Fi(O2) (from 140 to 20 litre min(-1)). (b) The CPAP valves maintain the required pressure within acceptable limits against varying flow. (ii) At all permutations, the mean inspiratory mask pressure was significantly lower than that required. At high inspiratory flow rates, the minimum inspiratory pressure approached atmospheric pressure. CONCLUSIONS The Whisperflow may not perform as expected. Clinicians should be cautious when using this device, particularly with high Fi(O2) and CPAP valve load. The flow setting should be set at maximum. Failure of CPAP therapy may be due to failure of the generator. Further in vivo data are required.
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Affiliation(s)
- G W Glover
- Intensive Care Unit, Bradford Teaching Hospitals NHS Foundation Trust, Duckworth Lane, Bradford BD9 6RJ, UK
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Gilbert RM, Hadlow NC, Walsh JP, Fletcher SJ, Brown SJ, Stuckey BG, Lim EM. Assessment of thyroid function during pregnancy: first‐trimester (weeks 9–13) reference intervals derived from Western Australian women. Med J Aust 2008; 189:250-3. [DOI: 10.5694/j.1326-5377.2008.tb02015.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Accepted: 05/13/2008] [Indexed: 11/17/2022]
Affiliation(s)
- Rhonda M Gilbert
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Perth, WA
- Department of Clinical Biochemistry, PathWest QEII Laboratory, Perth, WA
| | - Narelle C Hadlow
- Department of Biochemistry and Cytogenetics, Western Diagnostic Pathology, Perth, WA
| | - John P Walsh
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Perth, WA
- School of Medicine and Pharmacology, University of Western Australia, Perth, WA
| | - Stephen J Fletcher
- Department of Clinical Biochemistry, PathWest QEII Laboratory, Perth, WA
| | - Suzanne J Brown
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Perth, WA
| | - Bronwyn G Stuckey
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Perth, WA
- School of Medicine and Pharmacology, University of Western Australia, Perth, WA
- Keogh Institute for Medical Research, Perth, WA
| | - Ee Mun Lim
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Perth, WA
- Department of Clinical Biochemistry, PathWest QEII Laboratory, Perth, WA
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Panicker V, Wilson SG, Spector TD, Brown SJ, Falchi M, Richards JB, Surdulescu GL, Lim EM, Fletcher SJ, Walsh JP. Heritability of serum TSH, free T4 and free T3 concentrations: a study of a large UK twin cohort. Clin Endocrinol (Oxf) 2008; 68:652-9. [PMID: 17970774 DOI: 10.1111/j.1365-2265.2007.03079.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Thyroid hormone action influences many metabolic and synthetic processes, but the degree of regulation attributed to genes and environmental factors affecting normal variation remains controversial. DESIGN We investigated the magnitude of the genetic and environmental determination of serum concentrations of free (f) T3, fT4, TSH and the fT4 x TSH product and their variation, in a large cohort of twin pairs. Female dizygous and monozygous twins (849 and 213 pairs, respectively) from the TwinsUK registry (mean age 45.5, range 18-80 years) were studied. RESULTS Comparison of thyroid parameters within various groups showed no differences between smoking categories, and higher serum TSH and lower fT3 in subjects with positive thyroid antibodies. Using structural equation modelling, we estimated the heritable contribution to serum thyroid parameters (with 95% confidence intervals) to be 65% (58%-71%) for TSH, 65% (58%-71%) for the fT4 x TSH product, 39% (20%-55%) for fT4 and 23% (3%-41%) for fT3. CONCLUSIONS We conclude that genetic regulation is a particularly important determinant of TSH and the fT4 x TSH product, and is a less important determinant of fT4 and fT3 concentrations in Caucasian women. These data from a large well-characterized cohort suggest that while there is a strong heritable contribution to serum TSH, variation in fT4 and fT3 concentrations may be less explained by genetic factors and more driven by environmental effects than previously thought.
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Affiliation(s)
- V Panicker
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
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Menon DK, Wheeler DW, Wilkins IA, Phillips PD, Fletcher SJ, Penfold NW, Smith HL, Gupta AK, Matta BF. Integrated approaches to academic anaesthesia - the Cambridge experience. Anaesthesia 2004; 59:785-92. [PMID: 15270971 DOI: 10.1111/j.1365-2044.2004.03800.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [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: 11/30/2022]
Abstract
There is mounting concern about the pressures experienced by University Departments of Anaesthesia, which, if lost, could threaten undergraduate peri-operative medicine teaching, development of critical appraisal skills among anaesthetists, and the future of coherent research programs. We have addressed these problems by establishing a foundation course in scientific methods and research techniques (the Cambridge SMART Course), complemented by competitive, fully funded, 12-month academic trainee attachments. Research conducted during academic attachments has been published and used to underpin substantive grant applications allowing work towards higher degrees. Following the attachment, a flexible scheme ensures safe reintroduction to clinical training. Research at consultant level is facilitated by encouraging applications for Clinician Scientist Fellowships, and by ensuring that the University Department champions, legitimises and validates the allocation of research time within the new consultant contract. We believe that these are important steps in safeguarding research and teaching in anaesthesia, critical care and peri-operative medicine.
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Affiliation(s)
- D K Menon
- University Department of Anaesthesia, University of Cambridge, Box 93, Addenbrooke's Hospital, CB2 2QQ, UK.
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Abstract
We present a case of neurogenic pulmonary oedema (NPO) due to subarachnoid haemorrhage that resulted in hypoxia refractory to conventional mechanical ventilation. Prone positioning was employed, resulting in rapid and sustained improvement in oxygenation. We discuss the pathogenesis of NPO and the mechanism of action of prone ventilation. Prone ventilation may be of value in the management of NPO, both in treating life-threatening hypoxia and in optimizing neurological recovery. Further data are required on its effect on intracranial pressure after subarachnoid haemorrhage.
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Affiliation(s)
- S J Fletcher
- Intensive Care Unit, Department of Anaesthesia, Bradford Royal Infirmary, Bradford BD9 6RJ, UK.
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Cussons AJ, Bhagat CI, Fletcher SJ, Walsh JP. Brown-Séquard revisited: a lesson from history on the placebo effect of androgen treatment. Med J Aust 2002; 177:678-9. [PMID: 12463999 DOI: 10.5694/j.1326-5377.2002.tb05014.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2002] [Accepted: 09/27/2002] [Indexed: 11/17/2022]
Abstract
BACKGROUND In 1889, Brown-Séquard, aged 72, reported dramatic rejuvenating effects after self-administering testicular extracts of dogs and guinea-pigs. His report resulted in widespread use of testicular extracts throughout Europe and North America for several decades. More recently, the male ageing process has been attributed to partial androgen deficiency, or "andropause", and testosterone treatment is claimed to improve well-being in middle-aged and elderly men. DESIGN We prepared extracts from five dog testes using Brown-Séquard's methods and assayed testosterone concentrations. RESULTS Testosterone concentrations were four orders of magnitude less than that required for a biological effect. CONCLUSIONS Our study illustrates the marked placebo response that can be evoked by androgen treatment. It cautions against the empirical use of testosterone treatment for older men, unless a diagnosis of hypogonadism has been substantiated.
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Affiliation(s)
- Andrea J Cussons
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, WA, Australia
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Abstract
A 41-year old primigravida underwent caesarean section because of foetal distress following prostin induction of labour. Intraoperative coagulopathy, haemorrhage and hypotension necessitated a hysterectomy. Subsequently, she developed respiratory and renal failure, requiring mechanical ventilation and haemodialysis. She made a full recovery. The likely diagnosis was amniotic fluid embolism (AFE), a rare complication of pregnancy with a variable presentation, ranging from cardiac arrest and death through to mild degrees of organ system dysfunction with or without coagulopathy. The differential diagnosis includes pre-eclamptic toxaemia/pregnancy-induced hypertension, anaphylaxis and pulmonary embolism. There is no diagnostic test for AFE; the finding of foetal elements in the maternal circulation is non-specific. Historically, AFE was thought to induce cardiovascular collapse by mechanical obstruction of the pulmonary circulation. It is now thought that a combination of left ventricular dysfunction and acute lung injury occur, with activation of several of the clotting factors. An immunological basis for these effects is postulated. There is no specific therapy and treatment is supportive. The mortality of the condition remains high.
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Affiliation(s)
- S J Fletcher
- Intensive Care Unit, Liverpool Hospital, NSW, Australia
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Fletcher SJ. Central venous catheter related infection. Anaesth Intensive Care 1999; 27:425. [PMID: 10470406] [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] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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Abstract
In order to test the hypothesis that urine colour can be used as an index of hydration in critically ill patients, we selected 40 intensive care and high-dependency patients and correlated urine colour (scored on an eight-point scale) with various indices of hydration: urine:plasma sodium, osmolality and urea ratios, urine output and central venous pressure. In addition, we compared the colour-chart score with scores made by intensive care nurses (without the benefit of a colour chart) in order to test subjective assessment of urine colour. There were weak but statistically significant correlations between urine colour and urine output (Spearman's r = - 0.555) and between urine colour and urine:plasma sodium ratio (Spearman's r = - 0.459). Subjective assessment of urine colour appeared to be reliable. Thus, although urine colour does vary with hydration in the critically ill, assessment of urine colour adds little to the overall assessment of hydration in this group of patients.
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Mercer M, Fletcher SJ, Bishop GF. Suboptimal ward care of critically ill patients. Medical emergency teams improve care. BMJ 1999; 318:54-5. [PMID: 10068224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Abstract
We report a case of fracture of the cricoid cartilage associated with cricoid pressure during rapid sequence tracheal intubation in a patient with status asthmaticus. This patient had a history of laryngeal trauma 48 yr previously. Fracture of the cricoid cartilage has not been reported previously after cricoid pressure.
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Affiliation(s)
- K J Heath
- Anaesthetic Department, Norfolk and Norwich Hospital
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Due AD, Cook JA, Fletcher SJ, Qu ZC, Powers AC, May JM. A "cysteineless" GLUT1 glucose transporter has normal function when expressed in Xenopus oocytes. Biochem Biophys Res Commun 1995; 208:590-6. [PMID: 7695611 DOI: 10.1006/bbrc.1995.1379] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
To test the role of cysteines in the function of GLUT1 glucose transporter, site-directed mutagenesis was used to replace all six GLUT1 cysteines with serine residues. When the individual and combined Cys-->Ser mutants were expressed in Xenopus laevis oocytes, zero-trans uptake of 3-O-methylglucose was comparable to that seen in native GLUT1. The "cysteineless" construct also retained the kinetic features of GLUT1, including an asymmetric transport mechanism and similar substrate and inhibitor affinities. Whereas GLUT1 transport was inhibited by sulfhydryl reagents, that of the "cysteineless" construct was not. These results show that cysteines are not required for GLUT1 function or oligomer formation. The "cysteineless" construct may therefore serve as a template for reintroducing cysteines back into GLUT1 at sites useful for testing transporter structure and function.
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Affiliation(s)
- A D Due
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232
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Abstract
STUDY OBJECTIVE To present our preliminary experience using three doses of an equimilligram mixture of 1% tetracaine and 0.75% bupivacaine in 8.25% dextrose for spinal anesthesia in patients undergoing peripheral vascular surgery. SETTING Operating and recovery rooms at a university medical center. PATIENTS 60 patients who received femoral popliteal or femoral distal bypass with spinal anesthesia. INTERVENTIONS All patients had intravenous cannulae inserted and received lactated Ringer's solution. There were no bolus infusions of fluid preanesthesia. Fluid administration occurred at a rate of 8 to 15 ml/kg/hr, with additional fluid and inotropic drugs administered to treat hypotension. Oxygen (O2) was delivered by nasal cannula, and peripheral O2 saturation was monitored. Blood pressure (BP) was monitored every 1 to 5 minutes using an automatic BP device, and ECG was displayed continually. MEASUREMENTS AND MAIN RESULTS Initially, 8 patients received a dose of 15 mg of each drug combined with 0.2 mg of epinephrine injected in a 20-degree head-up tilt. Because the duration of anesthesia was prolonged, subsequent patients received 12 mg of each drug mixed with 0.2 mg of epinephrine for cases in which an extended duration was predicted and 10 mg of each drug plus epinephrine for proximal first-time bypasses. With mixtures of 15 mg, 12 mg, and 10 mg of each drug plus epinephrine, a mean duration of approximately 300 minutes of surgically acceptable anesthesia was obtained. As the dose was decreased, the SD increased. There was a 0% failure rate for the spinal anesthetics at doses of 15 mg and 12 mg of each drug and a 19.5% failure rate at a dose of 10 mg of each drug. In each case, the rapid onset of a sensory blockade regressed in a standard and predictable fashion. The decline in BP and the use of inotropic and vasoconstrictive drugs were comparable to those in previously published reports of spinal anesthetics using single drug techniques with smaller doses. In none of the patients were there any untoward cerebrovascular or neurologic events, nor were there any clinically evident episodes of coronary insufficiency. CONCLUSION Spinal anesthesia using bupivacaine and tetracaine mixed in a single-injection technique can last 5 hours at the T12 level without added untoward effects when compared with lower-dose spinal anesthetics.
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Affiliation(s)
- B H Hoff
- Department of Anesthesiology, University of Maryland School of Medicine, Baltimore
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Abstract
BACKGROUND Little is known about the extent to which changes in postures in clinical situations affect respiratory mechanics, even in humans with healthy respiratory systems. This study tested the hypothesis that posture has only small effects on overall respiratory system mechanics in healthy subjects, despite changes in parts of the respiratory system in some postures. METHODS Measurements were made of airway flow, airway and esophageal pressures, and rib cage and abdominal volume displacements (with inductance plethysmography) of awake, healthy subjects, relaxed at functional residual capacity, during external forcing at 0.2 Hz with a tidal volume of 8-10 ml/kg. From these measurements, discrete Fourier transform was used to calculate elastances (E) and resistances (R) of the total respiratory system, lungs, total chest wall, and compartments of the chest wall (rib cage, diaphragm-abdomen, and belly wall). Measurements were made while the subjects were in nine different postures: in six of these, the torso was straight; in three, the torso was bent or twisted. RESULTS Although changes in mechanics of parts of the respiratory system were evident in certain postures, overall respiratory mechanics were not greatly affected by posture. Changing from sitting to supine decreased E and R of the diaphragm-abdomen about 50% (P < .05), but total chest wall E and R changed only slightly. Lung E increased 24% (P < .05), but total respiratory E did not change (P < .05). Lung and total respiratory R increased 40-50% (P < .05) with this same change in posture. As long as the torso was straight, however, changes in orientation of 30 degrees from the horizontal or a shift to lateral posture resulted in only minor changes in the variables measured. Postures in which the torso was twisted or bent increased E of the total chest wall 20-30% compared to supine (P < .05), due to increases in E of one or more compartments. Respiratory system E also increased, at most 14%. Although lung R decreased 30-45% (P < .05) in these postures compared to supine with a straight torso, chest wall and total respiratory R generally were unchanged. CONCLUSIONS Changes in respiratory system mechanics over a wide range of postures that may be encountered clinically are relatively small in healthy awake subjects due to adaptability of total chest wall mechanical behavior.
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Affiliation(s)
- G M Barnas
- Anesthesiology Research Laboratories, University of Maryland School of Medicine, Baltimore 21201
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Abstract
We used a previously reported technique (Mackenzie et al., J. Appl. Physiol. 68: 2013-2018, 1990) to measure the effects of severe pulmonary edema on acinar cardiogenic gas mixing in anesthetized dogs. We also tested how increases in lung volume affected gas mixing in healthy lungs and during pulmonary edema. Cardiogenic gas mixing was evaluated by measurement of the rate of washout of xenon133 injected into an occluded pulmonary artery during apnea. The rate constant of xenon133 washout was 0.40 min-1 (+/- 0.06 SE) in the healthy lung at functional residual capacity. It decreased (P < 0.05) to 0.08 min-1 (+/- 0.03) when lung volume was raised 500 ml. Pulmonary edema was induced by injection of oleic acid (0.06 mg.kg-1) into the right atrium over a 4-min period; clinical signs of severe pulmonary edema were present after 90 min. The rate constant for xenon133 washout (0.07 +/- 0.03 min-1) was less than in the healthy lung (P < 0.05), and was not changed after lung volume was increased (P > 0.05). We conclude that, in the presence of severe pulmonary edema: (1) acinar resistance is increased and/or magnitude of cardiogenic oscillations is decreased; and (2) salutary effects of increased lung volume are not due to enhancement of cardiogenic gas mixing.
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Affiliation(s)
- G M Barnas
- Department of Anesthesiology, University of Maryland, Baltimore 21201
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Barnas GM, Mills PJ, Mackenzie CF, Fletcher SJ, Green MD. Effect of tidal volume on respiratory system elastance and resistance during anesthesia and paralysis. Am Rev Respir Dis 1992; 145:522-6. [PMID: 1546830 DOI: 10.1164/ajrccm/145.3.522] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Recent studies have shown that the mechanical properties of the respiratory system at normal breathing frequency in awake humans depend on tidal volume. Few measurements of respiratory system properties during anesthesia have accounted for this dependence. From measurements of airway pressure, flow and esophageal pressure, we calculated elastances and resistances of the total respiratory system (Ers and Rrs), chest wall (Ecw and Rcw), and lungs (El and Rl) in supine human volunteers during quasisinusoidal volume forcing in a normal range of breathing (250 to 800 ml) at normal breathing frequency (0.2 Hz). Measurements were made (1) with subjects awake and voluntarily relaxed; (2) after isoflurane-N2O anesthesia (end-tidal isoflurane concentration 0.3 to 0.5%); and (3) after complete muscle paralysis with vecuronium. In all conditions, Ers, Ecw, El, Rrs, and Rcw decreased at 800 ml tidal volume compared with 250 ml; Rl showed a similar decrease in awake measurements only. Compared with awake measurements, each elastance tended to increase after anesthesia, but only the increase in Ers was significant. Compared with anesthesia, there was no effect of paralysis on any measurement. We conclude that (1) tidal volume dependence of respiratory system properties in the normal range of breathing occurs in the absence of muscle activity; (2) anesthesia increases Ers and (3) respiratory muscle activity appears to be inhibited by isoflurane-N2O anesthesia at end-tidal isoflurane concentration of 0.3 to 0.5% during normocapnia.
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Affiliation(s)
- G M Barnas
- Department of Anesthesiology, University of Maryland, Baltimore 21201
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