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O'Neill B, Bradley JM, McKevitt AM, Heaney L, Riley M, McGovern V, MacMahon J. Prescribing practice for intermittent oxygen therapy: a GP survey. Chron Respir Dis 2016; 1:139-42. [PMID: 16281655 DOI: 10.1191/1479972304cd036oa] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Introduction:UK figures show that the prescription of home oxygen cylinders for intermittent use is substantial. Aim: To examine GP assessment criteria and prescribing practice for intermittent oxygen therapy in patients with a diagnosis of chronic obstructive pulmonary disease (COPD) in Northern Ireland. Methods:A postal questionnaire was sent to all GPs (n = 534) in two health boards who had prescribed cylinder oxygen in a six month period prior to the study. The questionnaire was piloted to establish reliability and validity. Results:Completed questionnaires were returned by 52% (280/534) of GPs. GPs ‘most frequently’ used advice from hospital specialists [82% (230/280)] to determine the need for intermittent oxygen. Criteria such as breathlessness score on exercise (e.g., BORG), oximetry on exercise, local guidelines or national guidelines were used less frequently or never. Conclusions:Most patients are likely to have been prescribed intermittent oxygen without any objective assessment. Implementation of evidence-based guidelines and a formal oxygen assessment service, would rationalize the use of intermittent oxygen therapy and enable better targeting of this expensive resource.
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Girvan HM, Bradley JM, Cheesman MR, Kincaid JR, Liu Y, Czarnecki K, Fisher K, Leys D, Rigby SEJ, Munro AW. Analysis of Heme Iron Coordination in DGCR8: The Heme-Binding Component of the Microprocessor Complex. Biochemistry 2016; 55:5073-83. [DOI: 10.1021/acs.biochem.6b00204] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bradley JM, Le Brun NE, Moore GR. Ferritins: furnishing proteins with iron. J Biol Inorg Chem 2016; 21:13-28. [PMID: 26825805 PMCID: PMC4771812 DOI: 10.1007/s00775-016-1336-0] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 01/06/2016] [Indexed: 12/04/2022]
Abstract
Ferritins are a superfamily of iron oxidation, storage and mineralization proteins found throughout the animal, plant, and microbial kingdoms. The majority of ferritins consist of 24 subunits that individually fold into 4-α-helix bundles and assemble in a highly symmetric manner to form an approximately spherical protein coat around a central cavity into which an iron-containing mineral can be formed. Channels through the coat at inter-subunit contact points facilitate passage of iron ions to and from the central cavity, and intrasubunit catalytic sites, called ferroxidase centers, drive Fe2+ oxidation and O2 reduction. Though the different members of the superfamily share a common structure, there is often little amino acid sequence identity between them. Even where there is a high degree of sequence identity between two ferritins there can be major differences in how the proteins handle iron. In this review we describe some of the important structural features of ferritins and their mineralized iron cores, consider how iron might be released from ferritins, and examine in detail how three selected ferritins oxidise Fe2+ to explore the mechanistic variations that exist amongst ferritins. We suggest that the mechanistic differences reflect differing evolutionary pressures on amino acid sequences, and that these differing pressures are a consequence of different primary functions for different ferritins.
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Bradley JM, Svistunenko DA, Lawson TL, Hemmings AM, Moore GR, Le Brun NE. Three Aromatic Residues are Required for Electron Transfer during Iron Mineralization in Bacterioferritin. Angew Chem Int Ed Engl 2015; 54:14763-7. [PMID: 26474305 PMCID: PMC4691338 DOI: 10.1002/anie.201507486] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 09/17/2015] [Indexed: 12/20/2022]
Abstract
Ferritins are iron storage proteins that overcome the problems of toxicity and poor bioavailability of iron by catalyzing iron oxidation and mineralization through the activity of a diiron ferroxidase site. Unlike in other ferritins, the oxidized di-Fe(3+) site of Escherichia coli bacterioferritin (EcBFR) is stable and therefore does not function as a conduit for the transfer of Fe(3+) into the storage cavity, but instead acts as a true catalytic cofactor that cycles its oxidation state while driving Fe(2+) oxidation in the cavity. Herein, we demonstrate that EcBFR mineralization depends on three aromatic residues near the diiron site, Tyr25, Tyr58, and Trp133, and that a transient radical is formed on Tyr25. The data indicate that the aromatic residues, together with a previously identified inner surface iron site, promote mineralization by ensuring the simultaneous delivery of two electrons, derived from Fe(2+) oxidation in the BFR cavity, to the di-ferric catalytic site for safe reduction of O2.
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Bradley JM, Svistunenko DA, Lawson TL, Hemmings AM, Moore GR, Le Brun NE. Three Aromatic Residues are Required for Electron Transfer during Iron Mineralization in Bacterioferritin. ACTA ACUST UNITED AC 2015; 127:14976-14980. [PMID: 27478271 PMCID: PMC4954121 DOI: 10.1002/ange.201507486] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 09/17/2015] [Indexed: 11/29/2022]
Abstract
Ferritins are iron storage proteins that overcome the problems of toxicity and poor bioavailability of iron by catalyzing iron oxidation and mineralization through the activity of a diiron ferroxidase site. Unlike in other ferritins, the oxidized di‐Fe3+ site of Escherichia coli bacterioferritin (EcBFR) is stable and therefore does not function as a conduit for the transfer of Fe3+ into the storage cavity, but instead acts as a true catalytic cofactor that cycles its oxidation state while driving Fe2+ oxidation in the cavity. Herein, we demonstrate that EcBFR mineralization depends on three aromatic residues near the diiron site, Tyr25, Tyr58, and Trp133, and that a transient radical is formed on Tyr25. The data indicate that the aromatic residues, together with a previously identified inner surface iron site, promote mineralization by ensuring the simultaneous delivery of two electrons, derived from Fe2+ oxidation in the BFR cavity, to the di‐ferric catalytic site for safe reduction of O2.
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Pfaffen S, Bradley JM, Abdulqadir R, Firme MR, Moore GR, Le Brun NE, Murphy MEP. A Diatom Ferritin Optimized for Iron Oxidation but Not Iron Storage. J Biol Chem 2015; 290:28416-28427. [PMID: 26396187 PMCID: PMC4653698 DOI: 10.1074/jbc.m115.669713] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Indexed: 12/30/2022] Open
Abstract
Ferritin from the marine pennate diatom Pseudo-nitzschia multiseries (PmFTN) plays a key role in sustaining growth in iron-limited ocean environments. The di-iron catalytic ferroxidase center of PmFTN (sites A and B) has a nearby third iron site (site C) in an arrangement typically observed in prokaryotic ferritins. Here we demonstrate that Glu-44, a site C ligand, and Glu-130, a residue that bridges iron bound at sites B and C, limit the rate of post-oxidation reorganization of iron coordination and the rate at which Fe(3+) exits the ferroxidase center for storage within the mineral core. The latter, in particular, severely limits the overall rate of iron mineralization. Thus, the diatom ferritin is optimized for initial Fe(2+) oxidation but not for mineralization, pointing to a role for this protein in buffering iron availability and facilitating iron-sparing rather than only long-term iron storage.
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Behera RK, Torres R, Tosha T, Bradley JM, Goulding CW, Theil EC. Fe(2+) substrate transport through ferritin protein cage ion channels influences enzyme activity and biomineralization. J Biol Inorg Chem 2015. [PMID: 26202907 DOI: 10.1007/s00775-015-1279-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Ferritins, complex protein nanocages, form internal iron-oxy minerals (Fe2O3·H2O), by moving cytoplasmic Fe(2+) through intracage ion channels to cage-embedded enzyme (2Fe(2+)/O2 oxidoreductase) sites where ferritin biomineralization is initiated. The products of ferritin enzyme activity are diferric oxy complexes that are mineral precursors. Conserved, carboxylate amino acid side chains of D127 from each of three cage subunits project into ferritin ion channels near the interior ion channel exits and, thus, could direct Fe(2+) movement to the internal enzyme sites. Ferritin D127E was designed and analyzed to probe properties of ion channel size and carboxylate crowding near the internal ion channel opening. Glu side chains are chemically equivalent to, but longer by one -CH2 than Asp, side chains. Ferritin D127E assembled into normal protein cages, but diferric peroxo formation (enzyme activity) was not observed, when measured at 650 nm (DFP λ max). The caged biomineral formation, measured at 350 nm in the middle of the broad, nonspecific Fe(3+)-O absorption band, was slower. Structural differences (protein X-ray crystallography), between ion channels in wild type and ferritin D127E, which correlate with the inhibition of ferritin D127E enzyme activity include: (1) narrower interior ion channel openings/pores; (2) increased numbers of ion channel protein-metal binding sites, and (3) a change in ion channel electrostatics due to carboxylate crowding. The contributions of ion channel size and structure to ferritin activity reflect metal ion transport in ion channels are precisely regulated both in ferritin protein nanocages and membranes of living cells.
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Bradley JM, Atkins EM. Coupled Cyber–Physical System Modeling and Coregulation of a CubeSat. IEEE T ROBOT 2015. [DOI: 10.1109/tro.2015.2409431] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Bradley JM, Moore GR, Le Brun NE. Mechanisms of iron mineralization in ferritins: one size does not fit all. J Biol Inorg Chem 2014; 19:775-85. [PMID: 24748222 DOI: 10.1007/s00775-014-1136-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 04/07/2014] [Indexed: 12/23/2022]
Abstract
Significant progress has been made in recent years toward understanding the processes by which an iron mineral is deposited within members of the ferritin family of 24mer iron storage proteins, enabled by high-resolution structures together with spectroscopic and kinetic studies. These suggest common characteristics that are shared between ferritins, namely, a highly symmetric arrangement of subunits that provides a protein coat around a central cavity in which the mineral is formed, channels through the coat that facilitate ingress and egress of ions, and catalytic sites, called ferroxidase centers, that drive Fe(2+) oxidation. They also reveal significant variations in both structure and mechanism amongst ferritins. Here, we describe three general types of structurally distinct ferroxidase center and the mechanisms of mineralization that they are associated with. The highlighted variation leads us to conclude that there is no universal mechanism by which ferritins function, but instead there exists several distinct mechanisms of ferritin iron mineralization.
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Hegarty BC, Bradley JM, Lappin MR, Balakrishnan N, Mascarelli PE, Breitschwerdt EB. Analysis of seroreactivity against cell culture-derived Bartonella spp. antigens in dogs. J Vet Intern Med 2013; 28:38-41. [PMID: 24341682 PMCID: PMC4895527 DOI: 10.1111/jvim.12263] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 10/02/2013] [Accepted: 10/28/2013] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND Little is known about the specificity of Bartonella spp. immunofluorescent antibody (IFA) assays in dogs. Bacteremia in sick dogs most often has been associated with Bartonella henselae (Bh), Bartonella vinsonii subspecies berkhoffii (Bvb), and Bartonella koehlerae (Bk). Clarification of the diagnostic utility of IFA serology when testing against these organisms is needed. OBJECTIVE To evaluate the specificity of Bartonella IFA assays utilizing 6 cell culture-grown antigen preparations. ANIMALS Archived sera from SPF dogs (n = 29) and from dogs experimentally infected with Bvb (n = 10) and Bh (n = 3). METHODS Antibodies (Abs) to Bvb genotypes I, II, and III, Bh serotype I, strains H-1 and SA2, and to Bk were determined by IFA testing. RESULTS Serum from naïve SPF dogs shown to be negative for Bartonella bacteremia did not react with any of the 6 Bartonella antigens by IFA testing. Dogs experimentally infected with Bvb genotype I developed Abs against homologous antigens, with no cross-reactivity to heterologous Bvb genotypes, Bh H-1, SA2 strains, or to Bk. Dogs experimentally infected with Bh serotype I developed Abs against Bh H-1, but not to Bh SA2 strain with no cross-reactive Abs to Bvb genotypes I-III or to Bk. CONCLUSIONS AND CLINICAL IMPORTANCE Bartonella spp. Ab responses during acute experimental infections are species and type specific.
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Kent L, Reix P, Innes JA, Zielen S, Le Bourgeois M, Braggion C, Lever S, Arets HGM, Brownlee K, Bradley JM, Bayfield K, O'Neill K, Savi D, Bilton D, Lindblad A, Davies JC, Sermet I, De Boeck K. Lung clearance index: evidence for use in clinical trials in cystic fibrosis. J Cyst Fibros 2013; 13:123-38. [PMID: 24315208 DOI: 10.1016/j.jcf.2013.09.005] [Citation(s) in RCA: 148] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 09/10/2013] [Accepted: 09/23/2013] [Indexed: 02/09/2023]
Abstract
The ECFS-CTN Standardisation Committee has undertaken this review of lung clearance index as part of the group's work on evaluation of clinical endpoints with regard to their use in multicentre clinical trials in CF. The aims were 1) to review the literature on reliability, validity and responsiveness of LCI in patients with CF, 2) to gain consensus of the group on feasibility of LCI and 3) to gain consensus on answers to key questions regarding the promotion of LCI to surrogate endpoint status. It was concluded that LCI has an attractive feasibility and clinimetric properties profile and is particularly indicated for multicentre trials in young children with CF and patients with early or mild CF lung disease. This is the first article to collate the literature in this manner and support the use of LCI in clinical trials in CF.
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O'Neill K, Bradley JM, Bradbury I, Johnston E, Reid A, McCaughan J, Moore JE, Tunney MM, Elborn JS. S10 Lung Clearance Index (LCI) and Pseudomonous aeruginosa in adults and children with Cystic Fibrosis (CF). Thorax 2013. [DOI: 10.1136/thoraxjnl-2013-204457.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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McCullough AR, Hughes CM, Tunney M, Elborn JS, Bradley JM. P181 Adherence to Treatment in Patients with Bronchiectasis Infected with Pseudomonas Aeruginosa. Thorax 2012. [DOI: 10.1136/thoraxjnl-2012-202678.242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Bradley JM, Marritt SJ, Kihlken MA, Haynes K, Hemmings AM, Berks BC, Cheesman MR, Butt JN. Redox and chemical activities of the hemes in the sulfur oxidation pathway enzyme SoxAX. J Biol Chem 2012; 287:40350-9. [PMID: 23060437 DOI: 10.1074/jbc.m112.396192] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND SoxAX enzymes initiate microbial oxidation of reduced inorganic sulfur compounds. Their catalytic mechanism is unknown. RESULTS Cyanide displaces the CysS(-) ligand to the active site heme following reduction by S(2)O(4)(2-) but not Eu(II). CONCLUSION An active site heme ligand becomes labile on exposure to substrate analogs. SIGNIFICANCE Elucidation of SoxAX mechanism is necessary to understand a widespread pathway for sulfur compound oxidation. SoxAX enzymes couple disulfide bond formation to the reduction of cytochrome c in the first step of the phylogenetically widespread Sox microbial sulfur oxidation pathway. Rhodovulum sulfidophilum SoxAX contains three hemes. An electrochemical cell compatible with magnetic circular dichroism at near infrared wavelengths has been developed to resolve redox and chemical properties of the SoxAX hemes. In combination with potentiometric titrations monitored by electronic absorbance and EPR, this method defines midpoint potentials (E(m)) at pH 7.0 of approximately +210, -340, and -400 mV for the His/Met, His/Cys(-), and active site His/CysS(-)-ligated heme, respectively. Exposing SoxAX to S(2)O(4)(2-), a substrate analog with E(m) ~-450 mV, but not Eu(II) complexed with diethylene triamine pentaacetic acid (E(m) ~-1140 mV), allows cyanide to displace the cysteine persulfide (CysS(-)) ligand to the active site heme. This provides the first evidence for the dissociation of CysS(-) that has been proposed as a key event in SoxAX catalysis.
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Bui SH, McLean KJ, Cheesman MR, Bradley JM, Rigby SEJ, Levy CW, Leys D, Munro AW. Unusual spectroscopic and ligand binding properties of the cytochrome P450-flavodoxin fusion enzyme XplA. J Biol Chem 2012; 287:19699-714. [PMID: 22500029 PMCID: PMC3366004 DOI: 10.1074/jbc.m111.319202] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 04/05/2012] [Indexed: 11/06/2022] Open
Abstract
The Rhodococcus rhodochrous strain 11Y XplA enzyme is an unusual cytochrome P450-flavodoxin fusion enzyme that catalyzes reductive denitration of the explosive hexahydro-1,3,5-trinitro-1,3,5-triazene (RDX). We show by light scattering that XplA is a monomeric enzyme. XplA has high affinity for imidazole (K(d) = 1.6 μM), explaining previous reports of a red-shifted XplA Soret band in pure enzyme. The true Soret maximum of XplA is at 417 nm. Similarly, unusually weak XplA flavodoxin FMN binding (K(d) = 1.09 μM) necessitates its purification in the presence of the cofactor to produce hallmark flavin contributions absent in previously reported spectra. Structural and ligand-binding data reveal a constricted active site able to accommodate RDX and small inhibitory ligands (e.g. 4-phenylimidazole and morpholine) while discriminating against larger azole drugs. The crystal structure also identifies a high affinity imidazole binding site, consistent with its low K(d), and shows active site penetration by PEG, perhaps indicative of an evolutionary lipid-metabolizing function for XplA. EPR studies indicate heterogeneity in binding mode for RDX and other ligands. The substrate analog trinitrobenzene does not induce a substrate-like type I optical shift but creates a unique low spin EPR spectrum due to influence on structure around the distal water heme ligand. The substrate-free heme iron potential (-268 mV versus NHE) is positive for a low spin P450, and the elevated potential of the FMN semiquinone/hydroquinone couple (-172 mV) is also an adaptation that may reflect (along with the absence of a key Thr/Ser residue conserved in oxygen-activating P450s) the evolution of XplA as a specialized RDX reductase catalyst.
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Bradley JM, Silkstone G, Wilson MT, Cheesman MR, Butt JN. Probing a Complex of Cytochrome c and Cardiolipin by Magnetic Circular Dichroism Spectroscopy: Implications for the Initial Events in Apoptosis. J Am Chem Soc 2011; 133:19676-9. [DOI: 10.1021/ja209144h] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bradley JM, Taylor CN. Georeferenced Mosaics for Tracking Fires Using Unmanned Miniature Air Vehicles. ACTA ACUST UNITED AC 2011. [DOI: 10.2514/1.45342] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Moran F, Piper A, Elborn JS, Bradley JM. Respiratory muscle pressures in non-CF bronchiectasis: Repeatability and reliability. Chron Respir Dis 2010; 7:165-71. [DOI: 10.1177/1479972310375595] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background: Respiratory muscle strength is used diagnostically in clinical practice and as an outcome measure in clinical trials in various chronic lung diseases. There is limited data on its repeatability in people with non-CF bronchiectasis. The aim of the present study was to assess the repeatability of maximal inspiratory (P Imax) and expiratory pressures (PEmax) in a group of patients with stable, moderate-to-severe non-CF bronchiectasis. Methods: Twenty participants with stable moderate-to-severe non-CF bronchiectasis were recruited. Respiratory muscle strength measurements (three maximal inspiratory and expiratory pressures) were made on 2 separate days. A standard protocol was used, including practice tests, before obtaining three technically acceptable and reproducible readings with a difference of 10% or less between values. Clinical trial registration number: ClinicalTrials.gov: NCT00487149. Results: The mean (SD) age of the non-CF bronchiectasis group was 63 (9) years. Maximal inspiratory pressures were repeatable with mean (SD) for highest PImax, Test 1 and Test 2, 75.90 (20) and 79.40 (19) cmH2O, and limits of agreement (mean difference ± 2SD) —3.50 ± 20 cmH2O, (p = 0.14). Maximal expiratory pressures differed significantly with mean (SD) for highest PEmax, Test 1 and Test 2, 102.25 (27) and 112.30 (32) cmH 2O, and limits of agreement (mean difference ± 2SD) —10.10 ± 35 cmH2O, (p = 0.02). The intraclass correlation coefficient (95% CI) for highest PImax and PEmax was 0.93 (95% CI 0.82 to 0.97) and 0.90 (95% CI 0.76 to 0.96), respectively. Conclusion: Maximal inspiratory pressure measurements were repeatable during a period of clinical stability in moderate-to-severe non-CF bronchiectasis, suggesting this may be a useful outcome measure in non-CF bronchiectasis. Once a baseline has been established, a second visit is not required. PEmax was not a repeatable measure and further study is necessary to ascertain how much practice testing is required to obtain an accurate value.
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Hawkins EC, Clay LD, Bradley JM, Davidian M. Demographic and historical findings, including exposure to environmental tobacco smoke, in dogs with chronic cough. J Vet Intern Med 2010; 24:825-31. [PMID: 20492480 DOI: 10.1111/j.1939-1676.2010.0530.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Controlled studies investigating risk factors for the common presenting problem of chronic cough in dogs are lacking. HYPOTHESIS/OBJECTIVES To identify demographic and historical factors associated with chronic cough in dogs, and associations between the characteristics of cough and diagnosis. ANIMALS Dogs were patients of an academic internal medicine referral service. Coughing dogs had a duration of cough>or=2 months (n=115). Control dogs had presenting problems other than cough (n=104). METHODS Owners completed written questionnaires. Demographic information and diagnoses were obtained from medical records. Demographic and historical data were compared between coughing and control dogs. Demographic data and exposure to environmental tobacco smoke (ETS) also were compared with hospital accessions and adult smoking rates, respectively. Characteristics of cough were compared among diagnoses. RESULTS Most coughing dogs had a diagnosis of large airway disease (n=88; 77%). Tracheobronchomalacia (TBM) was diagnosed in 59 dogs (51%), including 79% of toy breed dogs. Demographic risk factors included older age, smaller body weight, and being toy breed (P<.001). No association was found between coughing and month (P=.239) or season (P=.414) of presentation. Exposure to ETS was not confirmed to be a risk factor (P=.243). No historical description of cough was unique to a particular diagnosis. CONCLUSIONS AND CLINICAL IMPORTANCE Associations with age, size, and toy breeds were strong. TBM is frequent in dogs with chronic cough, but descriptions of cough should be used cautiously in prioritizing differential diagnoses. The association between exposure to ETS and chronic cough deserves additional study.
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Bradley JM, Thomson AJ, Inglis R, Milios CJ, Brechin EK, Piligkos S. MCD spectroscopy of hexanuclear Mn(iii) salicylaldoxime single-molecule magnets. Dalton Trans 2010; 39:9904-11. [DOI: 10.1039/c0dt00634c] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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O’Neill B, Elborn JS, MacMahon J, Bradley JM. Pulmonary rehabilitation and follow-on services: a Northern Ireland survey. Chron Respir Dis 2008; 5:149-54. [DOI: 10.1177/1479972308091825] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
There should be a clear pathway through pulmonary rehabilitation and follow-on services. The aim of this survey was to determine the characteristics of the different components of the patient pathway, that is, pulmonary rehabilitation programs, ongoing exercise facilities, and support networks in Northern Ireland. Questionnaires were sent to current providers of pulmonary rehabilitation, providers of ongoing exercise, and support groups in Northern Ireland. Findings relating to the current status of pulmonary rehabilitation in Northern Ireland up to January 2007 are reported. There are currently 23 pulmonary rehabilitation programs in Northern Ireland. There appears to be a pathway through the short-term pulmonary rehabilitation program (6–8 weeks). Programs met standards for structure and format, except for the frequency of supervised exercise. Not all programs have links for the provision of ongoing exercise, but a range of exercise programs are available in leisure centers in Northern Ireland that include people with respiratory disease. There are 13 support groups for patients with respiratory disease in Northern Ireland and their function is diverse. Pulmonary rehabilitation is established in Northern Ireland, although not all patients are able to access these. Facilities for ongoing exercise and support groups are less developed. Improvements could be facilitated by better communication within the patient pathway and a strategic coordinated approach.
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Bradley JM, Thomson AJ, McInnes EJL, Winpenny REP, Timco G. Magnetic circular dichroism spectroscopy of antiferromagnetically coupled hetero-metallic rings [H2NR2][Cr7MF8(O2CCMe3)16]. Dalton Trans 2008:3311-9. [DOI: 10.1039/b803269f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
BACKGROUND Non-invasive ventilation (NIV) may be a means to temporarily reverse or slow the progression of respiratory failure in cystic fibrosis (CF). OBJECTIVES To compare the effect of NIV versus no NIV in people with CF. SEARCH STRATEGY We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches, handsearching relevant journals and abstract books of conference proceedings. We searched the reference lists of each trial for additional publications possibly containing other trials. Most recent search: October 2006. SELECTION CRITERIA Randomised controlled trials comparing a form of pressure preset or volume preset NIV to no NIV in people with acute or chronic respiratory failure in CF. DATA COLLECTION AND ANALYSIS Three reviewers independently assessed trials for inclusion criteria and methodological quality, and extracted data. MAIN RESULTS Fifteen trials were identified; seven trials met the inclusion criteria with a total of 106 participants. Six trials evaluated single treatment sessions only and one evaluated a six-week intervention. Four trials (79 participants) evaluated NIV for airway clearance compared with an alternative chest physiotherapy method and showed that airway clearance may be easier with NIV and people with CF may prefer it. We were unable to find any evidence that NIV increases sputum expectoration, but it did improve some lung function parameters.Three trials (27 participants) evaluated NIV for overnight ventilatory support. Lung function and nocturnal transcutaneous carbon dioxide were evaluated within two trials. Due to the small numbers of participants and statistical issues, there were discrepancies in the results between the RevMan and the original trial analyses. No clear differences were found between NIV compared with oxygen or room air except for exercise performance, which significantly improved with NIV compared to room air over six weeks. AUTHORS' CONCLUSIONS Non-invasive ventilation may be a useful adjunct to other airway clearance techniques, particularly in people with CF who have difficulty expectorating sputum. Non-invasive ventilation, when used in addition to oxygen, may improve gas exchange during sleep to a greater extent than oxygen therapy alone in moderate to severe disease. These benefits of NIV have largely been demonstrated in single treatment sessions with small numbers of participants. The impact of this therapy on pulmonary exacerbations and disease progression remain unclear. There is a need for long-term randomised controlled trials which are adequately powered to determine the clinical effects of non-invasive ventilation in CF airway clearance and exercise.
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Patterson JE, Hewitt O, Kent L, Bradbury I, Elborn JS, Bradley JM. Acapella versus 'usual airway clearance' during acute exacerbation in bronchiectasis: a randomized crossover trial. Chron Respir Dis 2007; 4:67-74. [PMID: 17621572 DOI: 10.1177/1479972306075483] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Devices such as the Acapella may facilitate independent airway clearance, however, few clinical trials have investigated the efficacy of Acapella. The aim of this study was to compare the effectiveness of Acapella to 'usual airway clearance' in adults during an acute exacerbation of bronchiectasis requiring oral antibiotic therapy. Twenty patients with bronchiectasis and an acute exacerbation requiring oral antibiotic therapy were recruited into a randomized crossover trial. Patients were allocated to one of two groups determined by concealed computer generated randomization. Group 1 (n=10): airway clearance session using Acapella at home twice daily during oral antibiotic therapy. Group 2 (n=10): 'usual' airway clearance sessions at home during oral antibiotic therapy. Patients recorded duration of each treatment session, volume of sputum produced and perception of breathlessness. An independent assessor performed outcome measures of spirometric lung function, pulse oximetry and breathlessness at the beginning and end of the study period. The mean volume of sputum expectorated during Acapella sessions was greater than for usual airway clearance sessions although this difference was not significant 2.61 ml (95% CI-1.62 to 6.84). Mean duration of Acapella sessions was greater than usual airway clearance sessions and approached significance. There were no significant between group differences in changes in lung function. This study demonstrates that the Acapella device may offer an acceptable, user-friendly method of airway clearance in patients with bronchiectasis.
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Martin SE, Bradley JM, Buick JB, Bradbury I, Elborn JS. Flight assessment in patients with respiratory disease: hypoxic challenge testing vs. predictive equations. QJM 2007; 100:361-7. [PMID: 17525132 DOI: 10.1093/qjmed/hcm033] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Predictive equations have been proposed as a simpler alternative to hypoxic challenge testing (HCT) for determining the risk of in-flight hypoxia. AIM To assess agreement between hypoxic challenge testing (HCT) and predictive equations for assessment of in-flight hypoxia. DESIGN Retrospective study. METHODS Patients with chronic obstructive pulmonary disease (COPD) (n = 15), interstitial lung disease (ILD) (n = 15) and cystic fibrosis (CF) (n = 15) were studied. Spirometry was recorded prior to hypoxic inhalation and oxygen saturations (SpO2) were recorded before, after and during hypoxic inhalation. Blood gases were analysed before and after hypoxic inhalation and when SpO2 = 85%. An HCT was performed using the Ventimask method. The PaO2 at altitude was estimated for each group using four published predictive equations, which use values of PaO2 (ground) and lung function measurements to predict altitude PaO2. Results were interpreted using the BTS recommendations for prescription of in-flight oxygen post HCT. The Stuart Maxwell test of overall homogeneity was used to assess agreement between HCT results and each of the predictive equations. RESULTS Ground PaO2 was significantly greater in patients with CF than either ILD or COPD (p < 0.05). PaO2 in all three groups significantly decreased following HCT. With the exception of equation 3, significantly fewer patients in each group would require in-flight O2 if prescription was based on HCT, compared to predictive equations (p < 0.05). DISCUSSION Predictive equations considerably overestimate the need for in-flight O2, compared to HCT.
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