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Boyd JH, Randall SM, Brown AP, Maller M, Botes D, Gillies M, Ferrante A. Population Data Centre Profiles: Centre for Data Linkage. Int J Popul Data Sci 2020; 4:1139. [PMID: 32935041 PMCID: PMC7473267 DOI: 10.23889/ijpds.v4i2.1139] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The Centre for Data Linkage (CDL) was established at Curtin University, Western Australia, to develop infrastructure to enable cross-jurisdictional record linkage in Australia. The CDL’s operating model makes use of the ‘separation principle’, with content data typically provided to researchers directly by the data custodian; jurisdictional linkage where available are used within the linkage process. Along with conducting record linkage, the team has also invested in establishing a research programme in record linkage methodology and in developing modern record linkage software which can handle the size and complexity of today’s workloads. The Centre has been instrumental in the development of practical methods for privacy-preserving record linkage, with this methodology now regularly used for real-world linkages. While the promise of a nation-wide linkage system in Australia has yet to be met, distributed models provide a potential solution.
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Affiliation(s)
- J H Boyd
- Centre for Data Linkage, School of Public Health, Curtin University.,Department of Public Health, School of Psychology and Public Health, College of Science, Health & Engineering, La Trobe University
| | - S M Randall
- Centre for Data Linkage, School of Public Health, Curtin University
| | - A P Brown
- Centre for Data Linkage, School of Public Health, Curtin University
| | - M Maller
- Centre for Data Linkage, School of Public Health, Curtin University
| | - D Botes
- Centre for Data Linkage, School of Public Health, Curtin University
| | - M Gillies
- Centre for Data Linkage, School of Public Health, Curtin University
| | - A Ferrante
- Centre for Data Linkage, School of Public Health, Curtin University
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Brown AP, Randall SM, Boyd JH, Ferrante AM. Evaluation of approximate comparison methods on Bloom filters for probabilistic linkage. Int J Popul Data Sci 2019; 4:1095. [PMID: 32935029 PMCID: PMC7482522 DOI: 10.23889/ijpds.v4i1.1095] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION The need for increased privacy protection in data linkage has driven the development of privacy-preserving record linkage (PPRL) techniques. A popular technique using Bloom filters with cryptographic analyses, modifications, and hashing variations to optimise privacy has been the focus of much research in this area. With few applications of Bloom filters within a probabilistic framework, there is limited information on whether approximate matches between Bloom filtered fields can improve linkage quality. OBJECTIVES In this study, we evaluate the effectiveness of three approximate comparison methods for Bloom filters within the context of the Fellegi-Sunter model of recording linkage: Sørensen-Dice coefficient, Jaccard similarity and Hamming distance. METHODS Using synthetic datasets with introduced errors to simulate datasets with a range of data quality and a large real-world administrative health dataset, the research estimated partial weight curves for converting similarity scores (for each approximate comparison method) to partial weights at both field and dataset level. Deduplication linkages were run on each dataset using these partial weight curves. This was to compare the resulting quality of the approximate comparison techniques with linkages using simple cut-off similarity values and only exact matching. RESULTS Linkages using approximate comparisons produced significantly better quality results than those using exact comparisons only. Field level partial weight curves for a specific dataset produced the best quality results. The Sørensen-Dice coefficient and Jaccard similarity produced the most consistent results across a spectrum of synthetic and real-world datasets. CONCLUSION The use of Bloom filter similarity comparisons for probabilistic record linkage can produce linkage quality results which are comparable to Jaro-Winkler string similarities with unencrypted linkages. Probabilistic linkages using Bloom filters benefit significantly from the use of similarity comparisons, with partial weight curves producing the best results, even when not optimised for that particular dataset.
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Affiliation(s)
- AP Brown
- Centre for Data Linkage, Curtin University, Western Australia, Perth, Australia
| | - SM Randall
- Centre for Data Linkage, Curtin University, Western Australia, Perth, Australia
| | - JH Boyd
- Centre for Data Linkage, Curtin University, Western Australia, Perth, Australia
| | - AM Ferrante
- Centre for Data Linkage, Curtin University, Western Australia, Perth, Australia
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Abstract
Introduction Available and practical methods for privacy preserving linkage have shortcomings: methods utilising anonymous linkage codes provide limited accuracy while methods based on Bloom filters have proven vulnerable to frequency-based attacks. Objectives In this paper, we present and evaluate a novel protocol that aims to meld both the accuracy of the Bloom filter method with the privacy achievable through the anonymous linkage code methodology. Methods The protocol involves creating multiple match-keys for each record, with the composition of each match-key depending on attributes of the underlying datasets being compared. The protocol was evaluated through de-duplication of four administrative datasets and two synthetic datasets; the ‘answers’ outlining which records belonged to the same individual were known for each dataset. The results were compared against results achieved with un-encoded linkage and other privacy preserving techniques on the same datasets. Results The multiple match-key protocol presented here achieved high quality across all datasets, performing better than record-level Bloom filters and the SLK, but worse than field-level Bloom filters. Conclusion The presented method provides high linkage quality while avoiding the frequency based attacks that have been demonstrated against the Bloom filter approach. The method appears promising for real world use.
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Affiliation(s)
- S M Randall
- Curtin University, Western Australia, Perth, Australia
| | - A P Brown
- Curtin University, Western Australia, Perth, Australia
| | - A M Ferrante
- Curtin University, Western Australia, Perth, Australia
| | - J H Boyd
- Curtin University, Western Australia, Perth, Australia
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Brown AP, Reynolds RM, Denison FC. Healthy weight in pregnancy: time for a shift in approach? BJOG 2019; 126:996. [PMID: 30968995 PMCID: PMC6593962 DOI: 10.1111/1471-0528.15793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- A P Brown
- Tommy's Centre for Maternal and Fetal Health, MRC Centre for Reproductive Health, Queen's Medical Research Institute, Edinburgh, UK.,Simpson Centre for Reproductive Health, Royal Infirmary, Edinburgh, UK
| | - R M Reynolds
- Simpson Centre for Reproductive Health, Royal Infirmary, Edinburgh, UK.,British Heart Foundation Centre for Cardiovascular Science, Queen's Medical Research Institute, Edinburgh, UK
| | - F C Denison
- Simpson Centre for Reproductive Health, Royal Infirmary, Edinburgh, UK
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Anastasiou AD, Strafford S, Posada-Estefan O, Thomson CL, Hussain SA, Edwards TJ, Malinowski M, Hondow N, Metzger NK, Brown CTA, Routledge MN, Brown AP, Duggal MS, Jha A. β-pyrophosphate: A potential biomaterial for dental applications. Mater Sci Eng C Mater Biol Appl 2017; 75:885-894. [PMID: 28415544 DOI: 10.1016/j.msec.2017.02.116] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 12/09/2016] [Accepted: 02/21/2017] [Indexed: 10/20/2022]
Abstract
Tooth hypersensitivity is a growing problem affecting both the young and ageing population worldwide. Since an effective and permanent solution is not yet available, we propose a new methodology for the restoration of dental enamel using femtosecond lasers and novel calcium phosphate biomaterials. During this procedure the irradiated mineral transforms into a densified layer of acid resistant iron doped β-pyrophosphate, bonded with the surface of eroded enamel. Our aim therefore is to evaluate this densified mineral as a potential replacement material for dental hard tissue. To this end, we have tested the hardness of β-pyrophosphate pellets (sintered at 1000°C) and its mineral precursor (brushite), the wear rate during simulated tooth-brushing trials and the cytocompatibility of these minerals in powder form. It was found that the hardness of the β-pyrophosphate pellets is comparable with that of dental enamel and significantly higher than dentine while, the brushing trials prove that the wear rate of β-pyrophosphate is much slower than that of natural enamel. Finally, cytotoxicity and genotoxicity tests suggest that iron doped β-pyrophosphate is cytocompatible and therefore could be used in dental applications. Taken together and with the previously reported results on laser irradiation of these materials we conclude that iron doped β-pyrophosphate may be a promising material for restoring acid eroded and worn enamel.
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Affiliation(s)
- A D Anastasiou
- School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, UK.
| | - S Strafford
- Leeds Dental School, Worsley Building, University of Leeds, Leeds LS2 9JT, UK
| | - O Posada-Estefan
- Leeds Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, LS2 9JT, UK
| | - C L Thomson
- SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK
| | - S A Hussain
- SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK; Cambridge Graphene Centre, Engineering Department, University of Cambridge, 9, JJ Thomson Avenue, Cambridge CB3 0FA, UK
| | - T J Edwards
- SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK
| | - M Malinowski
- Leeds Dental School, Worsley Building, University of Leeds, Leeds LS2 9JT, UK
| | - N Hondow
- School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, UK
| | - N K Metzger
- SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK
| | - C T A Brown
- SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, UK
| | - M N Routledge
- Leeds Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, LS2 9JT, UK
| | - A P Brown
- School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, UK
| | - M S Duggal
- Leeds Dental School, Worsley Building, University of Leeds, Leeds LS2 9JT, UK
| | - A Jha
- School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, UK
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Abstract
Sebaceous naevus are associated with malignant transformation. They commonly occur in the head and neck region and are associated with malignant transformation into basal cell and squamous cell carcinomas. This case report describes a case of a malignant melanoma arising from a longstanding sebaceous naevus.
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Affiliation(s)
- A J Robinson
- a Northern Ireland Plastics and Maxillofacial Service, Ward 10/11, Ulster Hospital , Dundonald , Northern Ireland
| | - A P Brown
- a Northern Ireland Plastics and Maxillofacial Service, Ward 10/11, Ulster Hospital , Dundonald , Northern Ireland
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Simoes TA, Brown AP, Milne SJ, Brydson RMD. Bovine Serum Albumin binding to CoCrMo nanoparticles and the influence on dissolution. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/1742-6596/644/1/012039] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Simoes TA, Goode AE, Porter AE, Ryan MP, Milne SJ, Brown AP, Brydson RMD. Microstructural characterization of low and high carbon CoCrMo alloy nanoparticles produced by mechanical milling. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/1742-6596/522/1/012059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Yoon WS, Kim JT, Han YM, Chung DS, Park YS, Lizarraga KJ, Allen-Auerbach M, De Salles AA, Yong WH, Chen W, Ruge MI, Kickingereder P, Simon T, Treuer H, Sturm V, D'Alessandro PR, Jarrett J, Walling SA, Fleetwood IG, Kim TG, Lim DH, McGovern SL, Grosshans D, McAleer MF, Chintagumpala M, Khatua S, Vats T, Mahajan A, Beauchesne PD, Faure G, Noel G, Schmitt T, Martin L, Jadaud E, Carnin C, Astradsson A, Rosenschold PMA, Lund AKW, Feldt-Rasmussen U, Roed H, Juhler M, Kumar N, Kumar R, Sharma SC, Mukherjee KK, Khandelwal N, Kumar R, Gupta PK, Bansal A, Kapoor R, Ghosal S, Barney CL, Brown AP, Lowe MC, McAleer MF, Grosshans DR, de Groot JF, Puduvalli V, Gilbert MR, Vats TS, Brown PD, Mahajan A, Pollock BE, Stafford SL, Link MJ, Brown PD, Garces YI, Foote RL, Ryu S, Kim EY, Yechieli R, Kim JK, Mikkelsen T, Kalkanis S, Rock J, Prithviraj GK, Oppelt P, Arfons L, Cuneo KC, Vredenburgh J, Desjardins A, Peters K, Sampson J, Chang Z, Kirkpatrick J, Nath SK, Sheridan AD, Rauch PJ, Contessa JN, Yu JB, Knisely JP, Minja FJ, Vortmeyer AO, Chiang VL, Koto M, Hasegawa A, Takagi R, Sasahara G, Ikawa H, Kamada T, Iwadate Y, Matsutani M, Kanner AA, Sela G, Gez E, Matceyevsky D, Strauss N, Corn BW, Brachman DG, Smith KA, Nakaji P, Sorensen S, Redmond KJ, Mahone EM, Kleinberg L, Terezakis S, McNutt T, Agbahiwe H, Cohen K, Lim M, Wharam M, Horska A, Amendola B, Wolf A, Coy S, Blach L, Mesfin F, Suki D, Mahajan A, Rao G, Palkonda VAR, More N, Ganesan P, Kesavan R, Shunmugavel M, Kasirajan T, Maram VR, Kakkar S, Upadhyay P, Das S, Nigudgi S, Katz JS, Knisely JP, Ghaly M, Schulder M, Palkonda VAR, More N, Shunmugavel M, Kasirajan T, Ganesan P, Kakkar S, Maram VR, Nigudgi S, Upadhyay P, Das S, Kesavan R, Taylor RB, Schaner PE, Dragovic AF, Markert JM, Guthrie BL, Dobelbower MC, Spencer SA, Fiveash JB, Katz JS, Knisely JP, Ghaly M, Schulder M, Chen L, Guerrero-Cazares H, Ford E, McNutt T, Kleinberg L, Lim M, Quinones-Hinojosa A, Redmond K, Wernicke AG, Chao KC, Nori D, Parashar B, Yondorf M, Boockvar JA, Pannullo S, Stieg P, Schwartz TH, Leeman JE, Clump DA, Flickinger JC, Burton SA, Mintz AH, Heron DE, O'Neil SH, Wong K, Buranahirun C, Gonzalez-Morkos B, Brown RJ, Hamilton A, Malvar J, Sposto R, Dhall G, Finlay J, Olch A, Reddy K, Damek D, Gaspar L, Ney D, Kavanagh B, Waziri A, Lillehei K, Stuhr K, Chen C, Kalakota K, Offor O, Patel R, Dess R, Schumacher A, Helenowski I, Marymont M, Sperduto P, Chmura SJ, Mehta M, Zadeh G, Shi W, Liu H, Studenski M, Fu L, Peng C, Gunn V, Rudoler S, Farrell C, Andrews D, Chu J, Turian J, Rooney JW, Ramiscal JAB, Laack NN, Shah K, Surucu M, Melian E, Anderson D, Prabhu V, Origitano T, Sethi A, Emami B. CLIN-RADIATION THERAPY. Neuro Oncol 2012; 14:vi133-vi141. [PMCID: PMC3488792 DOI: 10.1093/neuonc/nos238] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023] Open
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Telford G, Brown AP, Rich A, English JSC, Pritchard DI. Wound debridement potential of glycosidases of the wound-healing maggot, Lucilia sericata. Med Vet Entomol 2012; 26:291-299. [PMID: 22620282 DOI: 10.1111/j.1365-2915.2011.01000.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The wound-healing maggot, Lucilia sericata Meigen (Diptera: Calliphoridae), degrades extracellular matrix components by releasing enzymes. The purpose of this study was to investigate the glycosylation profiles of wound slough/eschar from chronic venous leg ulcers and the complementary presence of glycosidase activities in first-instar excretions/secretions (ES1) and to define their specificities. The predominant carbohydrate moieties present in wound slough/eschar were determined by probing one-dimensional Western blots with conjugated lectins of known specificities. The presence of specific glycosidase activities in ES1 was determined using chromogenic and fluorogenic substrates. The removal of carbohydrate moieties from slough/eschar proteins by glycosidases in ES1 was determined by two-dimensional electrophoresis and Emerald 300 glycoprotein staining. α-D-glucosyl, α-D-mannosyl and N-acetylglucosamine residues were detected on slough/eschar-derived proteins. Furthermore, it was demonstrated that the treatment of slough/eschar with ES1 significantly reduced uptake of the carbohydrate-specific stain. Subsequently, α-D-glucosidase, α-D-mannosidase and N-acetylglucosaminidase activities were identified in ES1. Specific chromogenic and fluorogenic substrates and gel filtration chromatography showed that these activities result from distinct enzymes. These activities were mirrored in the removal of α-D-glucosyl, α-D-mannosyl and N-acetylglucosamine residues from proteins of slough/eschar from maggot-treated wounds. These data suggest that maggot glycosidases remove sugars from slough/eschar proteins. This may contribute to debridement, which is ultimately accomplished by a suite of biochemically distinct enzymes present in ES1.
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Affiliation(s)
- G Telford
- Immune Modulation Research Group, School of Pharmacy, University of Nottingham, Nottingham, UK.
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Bilton M, Brown AP, Milne SJ. Investigating the optimum conditions for the formation of calcium oxide, used for CO2sequestration, by thermal decomposition of calcium acetate. ACTA ACUST UNITED AC 2012. [DOI: 10.1088/1742-6596/371/1/012075] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Wallace R, Brown AP, Brydson R, Milne SJ, Hondow N, Wang P. Characterisation of ZnO nanoparticle suspensions for toxicological applications. ACTA ACUST UNITED AC 2012. [DOI: 10.1088/1742-6596/371/1/012080] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Dalacu D, Brown AP, Klemberg-Sapieha JE, Martinu L, Wertheimer MR, Najafi SI, Andrews MA. Characterization of Plasma-Deposited Au/Fluoropolymer Nanocomposite Films for Nonlinear Optical Application. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-544-167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractNanocomposite films consisting of gold nanoclusters embedded in a fluorocarbon matrix were prepared by simultaneous plasma polymerization of a fluorocarbon gas and magnetron sputtering of a gold target. The optical constants of the films were determined using variable angle spectroscopic ellipsometry (VASE). The Maxwell-Garnett (M-G) effective medium theory (EMT) was used to extract the microstructural characteristics (gold volume fraction, cluster size). The predictions of the M-G EMT were compared with the results from x-ray photoelectron spectroscopy. Angle-resolved measurements suggest the presence of a carbonaceous layer at the cluster surface. The presence of such a layer is discussed in the context of its influence on the validity of the optical model
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Telford G, Brown AP, Kind A, English JSC, Pritchard DI. Maggot chymotrypsin I from Lucilia sericata is resistant to endogenous wound protease inhibitors. Br J Dermatol 2010; 164:192-6. [PMID: 21175562 DOI: 10.1111/j.1365-2133.2010.10081.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND A chymotrypsin found in the secretions of Lucilia sericata and manufactured as a recombinant enzyme degrades chronic wound eschar ex vivo. OBJECTIVES To characterize the inhibition profile of the L. sericata recombinant chymotrypsin I. METHODS Activity of recombinant chymotrypsin I and its sensitivity to endogenous inhibitors were determined enzymatically using the fluorogenic substrate succinyl-alanyl-alanyl-prolyl-phenylalanyl-aminomethyl coumarin. RESULTS We report the presence of high concentrations of two endogenous inhibitors, α1-antichymotrypsin and α1-antitrypsin, in wound eschar and a trace of a third, α2-macroglobulin, with the potential to inhibit this debridement process. However, the addition of a soluble and inhibitor-containing extract of chronic wound eschar to chymotrypsin I did not affect activity of the enzyme, neither did the addition of purified native α1-antichymotrypsin or α1-antitrypsin, although chymotrypsin I was inhibited by α2-macroglobulin. Conversely, the mammalian equivalent, α-chymotrypsin, was inhibited by the purified native α1-antichymotrypsin, α1-antitrypsin and α2-macroglobulin and by the soluble extract of wound eschar. CONCLUSIONS The data suggest that the maggot-derived chymotrypsin I is biochemically distinct from human α-chymotrypsin and the lack of inhibition by wound eschar suggests a means by which chymotrypsin I activity survives within the wound to contribute towards debridement during maggot biotherapy.
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Affiliation(s)
- G Telford
- Immune Modulation Research Group, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK
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Telford G, Brown AP, Seabra RAM, Horobin AJ, Rich A, English JSC, Pritchard DI. Degradation of eschar from venous leg ulcers using a recombinant chymotrypsin from Lucilia sericata. Br J Dermatol 2010; 163:523-31. [PMID: 20491762 DOI: 10.1111/j.1365-2133.2010.09854.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Larvae of the greenbottle Lucilia sericata are used to debride nonhealing wounds and stimulate the production of fresh granulation tissue. Previous publications have shown that secretions from L. sericata contain a number of proteolytic activities including a chymotrypsin that degrades a number of extracellular matrix components such as fibronectin, laminin and collagen. OBJECTIVES To produce a recombinant L. sericata chymotrypsin (chymotrypsin I) and determine its effects on the degradation of patient wound eschar. METHODS An active recombinant chymotrypsin I from L. sericata was cloned and expressed in Sf9 cells and its subsequent effects ex vivo on eschar from venous leg ulcers were determined by two-dimensional electrophoresis. RESULTS The recombinant enzyme had the attributes of a chymotrypsin, possessing sequence homology with other chymotrypsins and demonstrating attributes of the native enzyme including cleavage of the chymotrypsin substrate succinyl-alanyl-alanyl-prolyl-phenylalanyl-7-amino-4-methyl coumarin, inhibition by phenylmethylsulphonyl fluoride and lack of inhibition by amidinophenylmethylsulphonyl fluoride. Importantly, the recombinant chymotrypsin cleaved the majority of proteins from slough/eschar from venous leg ulcers in a superior manner to chymotrypsins from human and bovine sources. CONCLUSIONS The ex vivo degradation of eschar from venous leg ulcers indicates the potential value of recombinant chymotrypsin I as a novel, stand-alone debridement agent.
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Affiliation(s)
- G Telford
- Immune Modulation Research Group, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, U.K
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Ward MB, Brown AP, Cox A, Curry A, Denton J. Microscopical analysis of synovial fluid wear debris from failing CoCr hip prostheses. ACTA ACUST UNITED AC 2010. [DOI: 10.1088/1742-6596/241/1/012022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Qaisar SA, Bilton M, Wallace R, Brydson R, Brown AP, Ward M, Milne SJ. Sol-gel synthesis and TEM-EDX characterisation of hydroxyapatite nanoscale powders modified by Mg, Sr or Ti. ACTA ACUST UNITED AC 2010. [DOI: 10.1088/1742-6596/241/1/012042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
1. Chloroplasts isolated from pea seedlings were incubated in sucrose-tris medium reinforced with salts of calcium, magnesium, manganese or iron, at concentrations up to 10mm. 2. Measurements of chloroplast-pellet volume and water content showed that the bivalent cations brought about a contraction in chloroplast volume and a loss of chloroplast water. This was further substantiated by density-gradient centrifugations. 3. Measurements of the light-scattering and apparent fluorescence of chloroplast suspensions confirmed this conclusion and eliminated the possibility of contraction being caused by centrifugal forces. 4. The uptake of (45)Ca(2+) was measured and shown to be competitive with diluent Ca(2+), Mg(2+) or Mn(2+) ions, indicating a mechanism of low specificity. 5. The chloroplast contraction was insensitive to light but could be made sensitive by the addition of ferric EDTA. This light-sensitivity was inhibited by added 3-(p-chlorophenyl)-1,1-dimethylurea and so probably involves the Hill reaction. 6. On the basis of these observations it is suggested that the process of contraction does not consume much energy, but that in light-activated contraction a previous step occurs that is conducive to contraction and that is energy-transducing. It is postulated that this step results in a local increase in concentration of bivalent ions, which promotes contraction.
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Affiliation(s)
- A P Brown
- Department of Biochemistry, University of Birmingham
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Feary JR, Venn AJ, Mortimer K, Brown AP, Hooi D, Falcone FH, Pritchard DI, Britton JR. Experimental hookworm infection: a randomized placebo-controlled trial in asthma. Clin Exp Allergy 2009; 40:299-306. [PMID: 20030661 PMCID: PMC2814083 DOI: 10.1111/j.1365-2222.2009.03433.x] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Epidemiological studies suggest that hookworm infection protects against asthma, and therefore that hookworm infection may have a direct or an indirect therapeutic potential in this disease. We now report the first clinical trial of experimental hookworm infection in people with allergic asthma. OBJECTIVES To determine the effects of experimental hookworm infection in asthma. METHODS Thirty-two individuals with asthma and measurable airway responsiveness to adenosine monophosphate (AMP) were randomized and double blinded to cutaneous administration of either ten Necator americanus larvae, or histamine solution (placebo), and followed for 16 weeks. The primary outcome was the change in provocation dose of inhaled AMP required to reduce forced expiratory volume in 1 s by 20% (PD(20)AMP) from baseline to week 16. Secondary outcomes included change in several measures of asthma control and allergen skin sensitivity and the occurrence of adverse effects. RESULTS Mean PD(20)AMP improved in both groups, more in the hookworm [1.49 doubling doses (DD)] than the placebo group (0.98 DD), but the difference between groups was not significant (0.51 DD; 95% confidence interval: -1.79 to 2.80; P=0.65). There were no significant differences between the two groups for other measures of asthma control or allergen skin sensitization. Infection was generally well tolerated. CONCLUSIONS Experimental infection with ten hookworm larvae in asthma did not result in significant improvement in bronchial responsiveness or other measures of asthma control in this study. However, infection was well tolerated and resulted in a non-significant improvement in airway responsiveness, indicating that further studies that mimic more closely natural infection are feasible and should be undertaken.
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Affiliation(s)
- J R Feary
- Division of Epidemiology and Public Health, University of Nottingham, Nottingham, UK
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Doak SH, Griffiths SM, Manshian B, Singh N, Williams PM, Brown AP, Jenkins GJS. Confounding experimental considerations in nanogenotoxicology. Mutagenesis 2009; 24:285-93. [PMID: 19351890 DOI: 10.1093/mutage/gep010] [Citation(s) in RCA: 182] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The development of novel nanomaterials with unique physico-chemical properties is increasing at a rapid rate, with potential applications across a broad range of manufacturing industries and consumer products. Nanomaterial safety is therefore becoming an increasingly contentious issue that has intensified over the past 4 years, and in response, a steady stream of studies focusing on nanotoxicology are emerging. However, it is becoming increasingly evident that nanomaterials cannot be treated in the same manner as chemical compounds with regards to their safety assessment, as their unique physico-chemical properties are also responsible for unexpected interactions with experimental components that generate misleading data-sets. In this report, we focus on nanomaterial interactions with colorimetric and fluorometric dyes, components of cell culture growth medium and genotoxicity assay components, and the resultant consequences on test systems are demonstrated. Thus, highlighting some of the potential confounding factors that need to be considered in order to ensure that in vitro genotoxicity assays report true biological impacts in response to nanomaterial exposure.
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Affiliation(s)
- S H Doak
- Institute of Life Science, Swansea University, Wales, UK.
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McCaffrey DD, Brown AP. Re: "Shooting a moving target" - a foreign body in the tendon of flexor pollicis longus. J Hand Surg Eur Vol 2008; 33:394-5. [PMID: 18562387 DOI: 10.1177/1753193408090126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- D. D. McCaffrey
- Northern Ireland Plastic & Maxillofacial Service, Ulster Hospital, Dundonald, Co. Down, N. Ireland and 6 Scolboa Meadow, 42 Ballynoe Road, Co. Antrim BT41 2QD, N. Ireland
| | - A. P. Brown
- Northern Ireland Plastic & Maxillofacial Service, Ulster Hospital, Dundonald, Co. Down, N. Ireland and 6 Scolboa Meadow, 42 Ballynoe Road, Co. Antrim BT41 2QD, N. Ireland
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Tang TY, Howarth SPS, Li ZY, Miller SR, Graves MJ, U-King-Im JM, Trivedi RA, Walsh SR, Brown AP, Kirkpatrick PJ, Gaunt ME, Gillard JH. Correlation of carotid atheromatous plaque inflammation with biomechanical stress: Utility of USPIO enhanced MR imaging and finite element analysis. Atherosclerosis 2008; 196:879-87. [PMID: 17350023 DOI: 10.1016/j.atherosclerosis.2007.02.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2006] [Revised: 01/24/2007] [Accepted: 02/05/2007] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The aim of this study was to explore whether there is a relationship between the degree of MR-defined inflammation using ultra small super-paramagnetic iron oxide (USPIO) particles, and biomechanical stress using finite element analysis (FEA) techniques, in carotid atheromatous plaques. METHODS AND RESULTS 18 patients with angiographically proven carotid stenoses underwent multi-sequence MR imaging before and 36 h after USPIO infusion. T(2)(*) weighted images were manually segmented into quadrants and the signal change in each quadrant normalised to adjacent muscle was calculated after USPIO administration. Plaque geometry was obtained from the rest of the multi-sequence dataset and used within a FEA model to predict maximal stress concentration within each slice. Subsequently, a new statistical model was developed to explicitly investigate the form of the relationship between biomechanical stress and signal change. The Spearman's rank correlation coefficient for USPIO enhanced signal change and maximal biomechanical stress was -0.60 (p=0.009). CONCLUSIONS There is an association between biomechanical stress and USPIO enhanced MR-defined inflammation within carotid atheroma, both known risk factors for plaque vulnerability. This underlines the complex interaction between physiological processes and biomechanical mechanisms in the development of carotid atheroma. However, this is preliminary data that will need validation in a larger cohort of patients.
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Affiliation(s)
- T Y Tang
- University Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Hills Road, Cambridge CB2 2QQ, UK
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Sanchis A, Brown AP, Sancho M, Martínez G, Sebastián JL, Muñoz S, Miranda JM. Dielectric characterization of bacterial cells using dielectrophoresis. Bioelectromagnetics 2007; 28:393-401. [PMID: 17471505 DOI: 10.1002/bem.20317] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [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: 11/11/2022]
Abstract
Measurements of dielectrophoretic collection spectra of Escherichia coli and Staphylococcus aureus suspensions are used for obtaining dielectric characteristics of both types of bacteria. The experiments are interpreted using a numerical method that models the cells as compartmented spherical or rod-like particles. We show the usefulness of this simple method to extract significant information about the electrical properties of Gram-negative and -positive bacteria.
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Affiliation(s)
- A Sanchis
- Departamento de Física Aplicada III, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, Madrid, Spain
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Lovely GR, Brown AP, Brydson R, Kirkland AI, Meyer RR, Chang LY, Jefferson DA, Falke M, Bleloch A. HREM of the {111} surfaces of iron oxide nanoparticles. Micron 2006; 37:389-95. [PMID: 16563776 DOI: 10.1016/j.micron.2006.01.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Mixed phase Fe3O4-gamma-Fe2O3 (magnetite-maghemite) iron oxide nanoparticles have been fabricated by colloidal routes. HRTEM/HRSTEM images of the nanoparticles show the presence of [111] facets that terminate with enhanced contrast, which is shown to be caused by the presence of additional cations at the edges of the nanoparticles. HRTEM images were taken on a FEI CM200 FEGTEM, a JEOL 3100 with a LaB6 source, and a double aberration corrected JEOL-JEM 2200FS FEGTEM. The enhanced contrast effect was observed on the [111] surface atomic layers resolved using each machine. HRSTEM images, taken on an aberration corrected STEM, resolved enhanced contrast at specific surface sites. Exit wave reconstruction was also carried out on focal series taken on a double aberration corrected JEOL-JEM 2200FS and showed similar highly resolved enhanced contrast at specific surface cation sites. It is apparent that additional cations are occupying the [111] terminating layers of these nanoparticle surfaces. The use of different microscopes and techniques in this paper provides strong evidence that the enhanced contrast is a real effect and not an effect caused by microscope aberrations.
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Affiliation(s)
- G R Lovely
- Institute for Materials Research, University of Leeds, Leeds LS2 9JT, UK
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Lovely GR, Brown AP, Brydson R, Kirkland AI, Meyer R, Chang LY, Jefferson DA, Falke M, Bleloch A. HREM of metallized {111} iron oxide nanoparticle surfaces. ACTA ACUST UNITED AC 2006. [DOI: 10.1088/1742-6596/26/1/045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Aghababazadeh R, Mirhabibi AR, Ghanbari H, Chizari K, Brydson RM, Brown AP. Synthesis of carbon nanotubes on alumina-based supports with different gas flow rates by CCVD method. ACTA ACUST UNITED AC 2006. [DOI: 10.1088/1742-6596/26/1/032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Abstract
A vaccine against the human hookworm Necator americanus is urgently required to reduce hookworm-induced morbidity in endemic areas. In the present study, recombinant hookworm calreticulin, a nominated vaccine candidate, has been tested in mice. Mice given calreticulin had 43-49% fewer worms in their lungs, compared to non-vaccinated controls, following challenge infection with infective hookworm larvae. These levels of protection were achieved in the absence of adjuvant following intraperitoneal administration of three doses of 15 microg antigen. Antigen was also encapsulated in PLG microparticles. Encapsulated calreticulin elicited higher levels of anti-calreticulin IgG1 than free antigen but failed to induce protective immunity. The protection induced by free calreticulin was associated with low levels of serum IgE and moderate lung eosinophilia whilst administration of calreticulin-loaded microparticles was associated with high levels of serum IgE and higher lung eosinophil activity, suggesting that the classical Th2 phenotype may not always be associated with protective immunity, albeit in experimental necatoriasis.
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Affiliation(s)
- J A Winter
- University of Nottingham, School of Pharmacy, University Park, Nottingham, NG7 2RD, UK
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Chambers L, Woodrow S, Brown AP, Harris PD, Phillips D, Hall M, Church JCT, Pritchard DI. Degradation of extracellular matrix components by defined proteinases from the greenbottle larva Lucilia sericata used for the clinical debridement of non-healing wounds. Br J Dermatol 2003; 148:14-23. [PMID: 12534589 DOI: 10.1046/j.1365-2133.2003.04935.x] [Citation(s) in RCA: 162] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Larvae of the greenbottle fly Lucilia sericata are used routinely for the clinical treatment of difficult necrotic and infected wounds. Degradation by proteinases contained in larval excretory/secretory (ES) products is thought to contribute to wound debridement by removal of dead tissue. However, proteinase activity may also affect host tissue remodelling processes. OBJECTIVES To identify proteolytic enzymes derived from L. sericata ES products with activities against fibrin and extracellular matrix (ECM) components. METHODS Larval proteinase activities were assayed in vitro using class-specific substrates and inhibitors. Their action against fibrin and ECM components was examined using sodium dodecyl sulphate-polyacrylamide gel electrophoresis. RESULTS Three classes of proteolytic enzyme were detected in the secretions using fluorescein isothiocyanate-labelled casein as a model substrate. The predominant activity belonged to serine proteinases (pH optima 8-9) of two different subclasses (trypsin-like and chymotrypsin-like), with a weaker aspartyl proteinase (pH 5) and a metalloproteinase (pH 9) with exopeptidase characteristics also present. Using skin-relevant ECM components as substrates L. sericata ES products solubilized fibrin clots and degraded fibronectin, laminin and acid-solubilized collagen types I and III. Hydrolysis of ECM macromolecules was inhibited by preincubating ES products with phenylmethylsulphonyl fluoride but not 4-amidinophenylmethylsulphonyl fluoride, indicating that degradation was due to the 'chymotrypsin-like' serine proteinase. CONCLUSIONS These data suggest that a combination of L. sericata ES proteinases involving chymotrypsin-like and trypsin-like activities could potentially influence wound healing events when maggots are introduced into necrotic and infected wounds, with the chymotrypsin-like activity involved in the remodelling of ECM components.
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Affiliation(s)
- L Chambers
- Immune Modulation Group, School of Pharmaceutical Sciences, Boots Science Building, University of Nottingham, UK
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Brown AP, Khan K. Hamartoma of a digital nerve associated with 'triggering' of the finger. Br J Plast Surg 2002; 55:366-7. [PMID: 12160556 DOI: 10.1054/bjps.2002.3826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Kores PJ, Molvray M, Weston PH, Hopper SD, Brown AP, Cameron KM, Chase MW. A phylogenetic analysis of Diurideae (Orchidaceae) based on plastid DNA sequence data. Am J Bot 2001. [PMID: 21669623 DOI: 10.2307/3558366] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
DNA sequence data from plastid matK and trnL-F regions were used in phylogenetic analyses of Diurideae, which indicate that Diurideae are not monophyletic as currently delimited. However, if Chloraeinae and Pterostylidinae are excluded from Diurideae, the remaining subtribes form a well-supported, monophyletic group that is sister to a "spiranthid" clade. Chloraea, Gavilea, and Megastylis pro parte (Chloraeinae) are all placed among the spiranthid orchids and form a grade with Pterostylis leading to a monophyletic Cranichideae. Codonorchis, previously included among Chloraeinae, is sister to Orchideae. Within the more narrowly delimited Diurideae two major lineages are apparent. One includes Diuridinae, Cryptostylidinae, Thelymitrinae, and an expanded Drakaeinae; the other includes Caladeniinae s.s., Prasophyllinae, and Acianthinae. The achlorophyllous subtribe Rhizanthellinae is a member of Diurideae, but its placement is otherwise uncertain. The sequence-based trees indicate that some morphological characters used in previous classifications, such as subterranean storage organs, anther position, growth habit, fungal symbionts, and pollination syndromes have more complex evolutionary histories than previously hypothesized. Treatments based upon these characters have produced conflicting classifications, and molecular data offer a tool for reevaluating these phylogenetic hypotheses.
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Affiliation(s)
- P J Kores
- Natural Heritage Inventory, Oklahoma Biological Survey, University of Oklahoma, 111 E. Chesapeake St., Norman, Oklahoma 73019 USA
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Brown AP, Fishbein DJ, Fisher WH. "Titicut follow-up": successful transfer of assaultive patients from a high security facility to a less restrictive setting. Adm Policy Ment Health 2001; 29:67-79. [PMID: 11811774 DOI: 10.1023/a:1013121032479] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Currently many state mental health agencies are redoubling their efforts to close or downsize state hospitals and place their populations in less restrictive settings. Prior to 1990, certain assaultive non-criminal male patients from public facilities operated by the Massachusetts Department of Mental Health (DMH) could be transferred to prison psychiatric facilities operated by the Department of Corrections (DOC). In 1989 that practice was declared illegal, and clients so placed were ordered returned to DMH facilities. This case study describes the liaison process by which patients remaining in the DOC facility returned to DMH facilities, describes their subsequent hospital course, and reviews the validity of policy assumptions made about these patients' needs in the context of this follow-up data. The results of this analysis indicate that many fewer patients in this group of primarily chronic schizophrenic men required a secure facility upon their return than was previously assumed.
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Affiliation(s)
- A P Brown
- Department of Psychiatry, University of Massachusetts Medical School, Worcester 01655, USA.
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Brown AP, Dunn MA, Goddard NJ, Hughes MA. Identification of a novel low-temperature-response element in the promoter of the barley (Hordeum vulgare L) gene blt101.1. Planta 2001; 213:770-780. [PMID: 11678282 DOI: 10.1007/s004250100549] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Two winter barley (Hordeum vulgare L. cv. Igri) genomic clones, lambda gblt101.1 and lambda gblt101.2, encoding the blt101 gene family, were isolated from a genomic library. Deletion analysis of the blt101.1 promoter, using transient beta-glucuronidase (GUS) reporter expression assays, indicated that it contains at least three regulatory regions. A 107-bp region between nucleotides -168 and -275 with respect to the translation initiation codon, confers high-level GUS reporter expression at low temperature and contains a sequence (designated CR1) that is highly conserved in equivalent positions within the promoters of both members of the blt101 gene family. A 10-bp motif contained within CR1 binds proteins present in nuclear extracts from both control and low-temperature-treated barley tissue. Loss-of-function experiments, using transient-expression analysis, confirmed that this motif acts as a previously unreported low-temperature-responsive element. Nuclease sensitivity analysis of intact chromatin indicated that the blt101.1 promoter becomes more susceptible to DNase and micrococcal nuclease at low temperature, consistent with chromatin reorganisation upon transcriptional induction. It is proposed that both the 10-bp motif and chromatin reorganisation are involved in the regulation of blt101.1 at low temperature. This is the first detailed analysis of a low-temperature-specific plant promoter and identifies a novel low-temperature-response element.
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Affiliation(s)
- A P Brown
- School of Biochemistry and Genetics, The Medical School, University of Newcastle upon Tyne, UK
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Brown AP, Lewis H, Sinclair S. The contralateral superficial inferior epigastric artery flap as a backup in breast reconstruction. Br J Plast Surg 2001; 54:557-8. [PMID: 11513531 DOI: 10.1054/bjps.2001.3609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Falcone FH, Rossi AG, Sharkey R, Brown AP, Pritchard DI, Maizels RM. Ascaris suum-derived products induce human neutrophil activation via a G protein-coupled receptor that interacts with the interleukin-8 receptor pathway. Infect Immun 2001; 69:4007-18. [PMID: 11349070 PMCID: PMC98463 DOI: 10.1128/iai.69.6.4007-4018.2001] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Infection with tissue-migrating helminths is frequently associated with intense granulocyte infiltrations. Several host-derived factors are known to mediate granulocyte recruitment to the tissues, but less attention has been paid to how parasite-derived products trigger this process. Parasite-derived chemotactic factors which selectively recruit granulocytes have been described, but nothing is known about which cellular receptors respond to these agents. The effect of products from the nematodes Ascaris suum, Toxocara canis, and Anisakis simplex on human neutrophils were studied. We monitored four parameters of activation: chemotaxis, cell polarization, intracellular Ca(2+) transients, and priming of superoxide anion production. Body fluids of A. suum (ABF) and T. canis (TcBF) induced strong directional migration, shape change, and intracellular Ca(2+) transients. ABF also primed neutrophils for production of superoxide anions. Calcium mobilization in response to A. suum-derived products was completely abrogated by pretreatment with pertussis toxin, implicating a classical G protein-coupled receptor mechanism in the response to ABF. Moreover, pretreatment with interleukin-8 (IL-8) completely abrogated the response to ABF, demonstrating desensitization of a common pathway. However, ABF was unable to fully desensitize the response to IL-8, and binding to CXCR1 or CXCR2 was excluded in experiments using RBL-2H3 cells transfected with the two human IL-8 receptors. Our results provide the first evidence for a direct interaction between a parasite-derived chemotactic factor and the host's chemotactic network, via a novel G protein-coupled receptor which interacts with the IL-8 receptor pathway.
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Affiliation(s)
- F H Falcone
- Institute of Cell, Animal and Population Biology, University of Edinburgh, Ashworth Laboratories, United Kingdom
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Brown AP, Kennedy AD, Torgerson DJ, Campbell J, Webb JA, Grant AM. The OMENS trial: opportunistic evaluation of musculo-skeletal physician care among orthopaedic outpatients unlikely to require surgery. Health Bull (Edinb) 2001; 59:198-210. [PMID: 12664761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
STUDY OBJECTIVE For orthopaedic outpatients judged as unlikely to require surgery, how does the cost-effectiveness of treatment from a musculo-skeletal medicine physician compare with that of a conventional orthopaedic surgeon-led service? DESIGN Partially randomised, pragmatic trial comparing management from a single musculo-skeletal medicine physician with orthopaedic surgeon-led management, with the timing and nature of treatments at the discretion of individual clinicians. Main outcomes were: change in patient reported health (SF-36 and EuroQol), and marginal health service costs. SETTING Outpatient department of an Edinburgh orthopaedic hospital. SUBJECTS One thousand three hundred and twenty six people; aged over 18, referred to and later attending the outpatient department with a 'non-surgical' musculo-skeletal condition, who provided baseline information. Eight hundred and twenty nine were randomly allocated to management by either the musculo-skeletal medicine physician (medical group) or a conventional orthopaedic surgeon-led service (surgical group); 497 were assigned to the treatment groups according to their general practitioner's preference. RESULTS There are aspects of the study design concerning statistical power, potential selection bias and generalisability, which mean that any results must be treated with caution. Although there was no statistically significant difference in health gain between the randomly allocated groups (with similar findings in the non-randomised medical and surgical groups), the patient groups were heterogeneous and the confidence intervals did not rule out clinically important differences. The medical group received more outpatient treatment, 20% vs. 10% (difference 95% CI 5% to 15%) with a higher rate of physiotherapy referral, 45% vs. 30% (15%, 9% to 22%). The surgical group received more inpatient surgical care 6% vs. 17% (-11%, -15% to -7%). Mean healthcare costs in the medical group were 179 Pounds per patient compared with 287 Pounds in the surgical group (-108 Pounds, -25 Pounds to -191 Pounds). CONCLUSIONS Interpretation should take into account the practical difficulties and circumstances of the study. Although no differences in health gain were found between these two management policies for 'non-surgical' orthopaedic outpatients, the trial was less statistically powerful than planned and the confidence intervals included clinically important differences. Differences in treatment emphasis gave estimated costs savings to the Health Service of 108 Pounds per patient treated by the musculo-skeletal medicine service.
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Affiliation(s)
- A P Brown
- Health Services Research Unit, University of Aberdeen, Polwarth Building, Foresterhill, Aberdeen
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Chua YL, Brown AP, Gray JC. Targeted histone acetylation and altered nuclease accessibility over short regions of the pea plastocyanin gene. Plant Cell 2001; 13:599-612. [PMID: 11251099 PMCID: PMC135505 DOI: 10.1105/tpc.13.3.599] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2000] [Accepted: 01/09/2001] [Indexed: 05/17/2023]
Abstract
The chromatin structure of the pea plastocyanin gene (PetE) was examined at three different transcriptional states by investigating the acetylation states of histones H3 and H4 and the nuclease accessibility of the gene in pea roots, etiolated shoots, and green shoots. The acetylation states of histones associated with different regions of PetE were analyzed by chromatin immunoprecipitation with antibodies specific for acetylated or nonacetylated histone H3 or H4 tails, followed by polymerase chain reaction quantification. Comparison of pea tissues indicated that histone hyperacetylation was associated with increased PetE transcription in green shoots. Moreover, hyperacetylation of both histones H3 and H4 was targeted to the enhancer/promoter region in green shoots, suggesting that only specific nucleosomes along the gene were modified. Time-course digestions of nuclei with micrococcal nuclease and DNaseI indicated that the enhancer/promoter region was more resistant to digestion in the inactive gene in pea roots than was the same region in the active gene in shoots, whereas the transcribed region of PetE was digested similarly among the tissues. This finding indicates that transcription is accompanied by changes in the nuclease accessibility of the enhancer/promoter region only. Moreover, these results indicate that the changes in nuclease accessibility are organ specific, whereas histone hyperacetylation is light dependent, and they suggest that changes in nuclease accessibility precede histone hyperacetylation during PetE activation.
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Affiliation(s)
- Y L Chua
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, United Kingdom
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Chua YL, Brown AP, Gray JC. Targeted histone acetylation and altered nuclease accessibility over short regions of the pea plastocyanin gene. Plant Cell 2001; 13:599-612. [PMID: 11251099 DOI: 10.2307/3871409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The chromatin structure of the pea plastocyanin gene (PetE) was examined at three different transcriptional states by investigating the acetylation states of histones H3 and H4 and the nuclease accessibility of the gene in pea roots, etiolated shoots, and green shoots. The acetylation states of histones associated with different regions of PetE were analyzed by chromatin immunoprecipitation with antibodies specific for acetylated or nonacetylated histone H3 or H4 tails, followed by polymerase chain reaction quantification. Comparison of pea tissues indicated that histone hyperacetylation was associated with increased PetE transcription in green shoots. Moreover, hyperacetylation of both histones H3 and H4 was targeted to the enhancer/promoter region in green shoots, suggesting that only specific nucleosomes along the gene were modified. Time-course digestions of nuclei with micrococcal nuclease and DNaseI indicated that the enhancer/promoter region was more resistant to digestion in the inactive gene in pea roots than was the same region in the active gene in shoots, whereas the transcribed region of PetE was digested similarly among the tissues. This finding indicates that transcription is accompanied by changes in the nuclease accessibility of the enhancer/promoter region only. Moreover, these results indicate that the changes in nuclease accessibility are organ specific, whereas histone hyperacetylation is light dependent, and they suggest that changes in nuclease accessibility precede histone hyperacetylation during PetE activation.
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Affiliation(s)
- Y L Chua
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, United Kingdom
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Wilmer JA, Brown AP, Forsyth K, Carnaby S, Barsby T, Slabas AR. Limnanthes douglasii erucic acid-specific lysophospatidic acid acyltransferase activity in oilseed rape: an analysis of biochemical effects. Biochem Soc Trans 2000; 28:964-6. [PMID: 11171273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
It has been shown previously that erucic acid accumulates in the sn-2 position of triglycerides after introduction of a Limnanthes lysophosphatidic acid acyltransferase. However, in none of the studies to date has a proper evaluation been made of the relationship between transgene expression and the erucic acid accumulation at sn-2. One of the necessary tools to study the variability is the presence of a specific antibody raised against the introduced acyltransferase. In the present study, we have looked at the correlation between erucic acid accumulation at sn-2, production of trierucin and the expression of the transgene, as detected by Western blotting. The data presented include comparisons of progeny of individual lines grown under various conditions and at various times, and an analysis of a number of lines during development. We also present calculations that could indicate from which position the erucic acid found at position sn-2 is derived.
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Affiliation(s)
- J A Wilmer
- Biogemma UK, 200 Cambridge Science Park, Cambridge CB4 0GZ, UK.
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Brown AP, Jensen KO, Walker AB. Calculations of the angular correlation of positron annihilation at ideal and defected aluminium surfaces. ACTA ACUST UNITED AC 2000. [DOI: 10.1088/0305-4608/18/7/003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Abstract
There have been several studies analysing the outcome of reduction mammaplasty in the literature. Our study is condition specific, with emphasis placed on the patients' subjective experience of treatment. Following a successful pilot study, data were obtained from 74 patients' charts and an anonymous postal questionnaire over a 1-year period. Sixty-six returned the questionnaire complete (89%). Overall satisfaction with the procedure was high (94%). The outcome of surgery with respect to breast size, shape, nipple position, sensation and scarring is documented. All patients expressed marked improvement regarding neck pain, back pain, submammary rash, breast pain and shoulder grooving. Other parameters including psychological wellbeing, quality of life, time on the waiting list, weight of tissue removed and complication rates are analysed. The findings of this study demonstrate overwhelming physical and psychological benefits from surgery. This supports the suggestion that reduction mammaplasty is not primarily cosmetic, producing significant improvement in symptoms.
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Affiliation(s)
- A P Brown
- Northern Ireland Plastic and Maxillofacial Service, The Ulster Hospital, Belfast, Northern Ireland
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Kagan AR, Rose CM, Bedwinek JM, Blitzer PH, Brascho DJ, Brown AP, Coia LR, Earle JD, Janjan NA, Lowy RO, Pieters RS, Rotman M, Leibel SA. Bone metastases. American College of Radiology. ACR Appropriateness Criteria. Radiology 2000; 215 Suppl:1077-104. [PMID: 11037533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Affiliation(s)
- A R Kagan
- Bone Metastases Work Group, Kaiser Permanente Medical Center, Los Angeles, Calif., USA
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Brown AP, Dinger N, Levine BS. Stress produced by gavage administration in the rat. Contemp Top Lab Anim Sci 2000; 39:17-21. [PMID: 11178310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
This research project examined the relationship between gavage administration of various vehicles and induction of the stress response, as defined by increased plasma corticosterone levels, in the rat. In addition, we assessed elicitation of clinical signs of distress and aspiration leading to airway/pulmonary changes. We studied various vehicles used in toxicology studies, including water, corn oil, and 1% methylcellulose/0.2% Tween 80. Male CD rats received a single gavage administration of vehicle, blood was collected 1 h after dosing for measurement of plasma corticosterone, and necropsies were performed 4 h after dosing. Gavage administration of corn oil at. 20 mL/kg, but not 1% methylcellulose/0.2% Tween 80 or water, induced a stress response in a volume-dependent fashion, resulting in elevated plasma corticosterone levels. This response was not due to aspiration, which occurred after administration of. 20 mL/kg of water or 1% methylcellulose/0.2% Tween 80 but not corn oil. Administration of corn oil at 40 mL/kg resulted in plasma corticosterone levels that were elevated for 4 h. The stress response produced by corn oil was not unique to this vehicle but also occurred after gavage administration of sesame, soybean, and peanut oils. Our data indicate that gavage dosing of lipid vehicles induces activation of the stress response, as indicated by increased adrenal output of corticosterone, in a volume-dependent fashion. In conclusion, gavage administration of various vehicles can result in aspiration, pulmonary injury, and/or elicitation of a stress response in a vehicle- and dose volume-dependent fashion. The results of our project suggest that dose volumes for gavage administration in the rat generally should not exceed 10 mL/kg.
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Affiliation(s)
- A P Brown
- Toxicology Research Laboratory, Department of Pharmacology, University of Illinois at Chicago, 1940 W. Taylor Street, Chicago, IL 60612-7353, USA
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Brown AP, Morrissey RL, Crowell JA, Levine BS. Difluoromethylornithine in combination with tamoxifen in female rats: 13-week oral toxicity study. Cancer Chemother Pharmacol 1999; 44:475-83. [PMID: 10550568 DOI: 10.1007/s002800051121] [Citation(s) in RCA: 12] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
PURPOSE Cancer chemoprevention is the use of pharmacologic or natural agents to inhibit the development of cancer. Difluoromethylornithine (DFMO) is an irreversible inhibitor of ornithine decarboxylase, the rate-limiting enzyme in the biosynthesis of polyamines. DFMO has demonstrated chemopreventive efficacy in animal models of tumorigenesis. Tamoxifen (TAM) is currently used for treatment of estrogen receptor-positive breast carcinoma and has demonstrated efficacy in chemoprevention of breast cancer in women at high risk for the disease. The administration of tamoxifen with DFMO is being considered for development by the National Cancer Institute as a potential drug regimen for the chemoprevention of breast carcinoma. METHODS The toxicity of DFMO in combination with TAM was evaluated in female rats following 13 weeks of daily administration by gavage. Dose groups were vehicle control, DFMO (1000 mg/kg per day), low TAM (0.25 mg/kg per day), high TAM (2.5 mg/kg per day), low combination (1000 + 0.25) and high combination (1000 + 2.5). RESULTS No mortalities occurred in the study. Clinical signs of toxicity were limited to dermal lesions consisting of scab formation and abrasions produced by DFMO. Administration of either DFMO or TAM resulted in decreased body weight gains, with coadministration having an additive effect. Serum albumin, total protein, cholesterol and triglyceride levels were decreased in all drug-treated dose groups, although histologic evidence of liver lesions were not seen. TAM resulted in increased numbers of red blood cells, whereas DFMO produced a slightly anemic response. DFMO produced lesions in the small intestine consisting of necrosis of crypt epithelium and crypt microabscess, which were enhanced by TAM coadministration. Administration of TAM resulted in histologic changes in the ovaries, fallopian tube, vagina, cervix and uterus, indicating that inhibition of ovulation and reproductive cycle arrest in the proestrus stage had occurred. Coadministration with DFMO did not affect the changes to the reproductive system induced by TAM. CONCLUSIONS Coadministration of DFMO with tamoxifen did not result in toxicity unique to the combination drug regimen, but rather toxicity resulted from administration of each drug. Under the conditions of the study, the overall toxicity produced by dual administration of DFMO with tamoxifen was additive with respect to the toxicity associated with each agent alone.
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Affiliation(s)
- A P Brown
- Toxicology Research Laboratory, Department of Pharmacology, University of Illinois at Chicago (UIC), 1940 West Taylor Street, Chicago, IL 60612-7353, USA.
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Daly B, Betts WB, Brown AP, O'Neill JG. Bacterial loss from biofilms exposed to free chlorine. Microbios 1999; 96:7-21. [PMID: 10347898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Previous studies have demonstrated the increased resistance of biofilm bacteria to biocides when compared with freely suspended planktonic cells, but there have been few investigations of sloughing and losses from biofilms in response to biocide activity. A model biofilm system was used to demonstrate that the loss of sloughed bacteria (including Escherichia coli as a pathogen indicator organism) from actively growing biofilm reached levels of 10(6)-10(7) CFU ml-1 of eluted medium. The sloughing response was examined in response to a range of free chlorine concentrations from 0.6 to 5.0 mg l-1. While chlorine treatment greatly reduced bacterial sloughing, significant bacterial loss into the planktonic phase still occurred with free chlorine concentrations below 3.0 mg l-1, indicating active growth and sloughing of biofilm organisms. Exposure of the biofilm to higher levels of free chlorine resulted in inhibition of bacterial loss, though biocide removal was accompanied by a rapid, almost immediate, recovery of sloughing ability. This work demonstrates the endurance and speed of biofilm recovery upon quenching of chlorine residuals, highlighting a potentially significant public health risk from biofilm recovery and the sloughing of pathogenic organisms associated with the biofilm.
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Affiliation(s)
- B Daly
- Department of Biology, University of York, Great Britain
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Brown AP, Morrissey RL, Crowell JA, Levine BS. Thirteen-week oral toxicity study of difluoromethylornithine in combination with tamoxifen citrate in female dogs. Cancer Chemother Pharmacol 1999; 43:479-88. [PMID: 10321508 DOI: 10.1007/s002800050927] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [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: 12/01/2022]
Abstract
PURPOSE Cancer chemoprevention is the use of pharmacologic or natural agents to inhibit the development of cancer. Difluoromethylornithine (DFMO) is an irreversible inhibitor of ornithine decarboxylase, the rate-limiting enzyme in the biosynthesis of polyamines. DFMO has demonstrated chemopreventive efficacy in animal models of tumorigenesis. Tamoxifen (TAM), a nonsteroidal antiestrogen, is approved for use in the treatment of estrogen receptor-positive breast carcinoma and has demonstrated efficacy in chemoprevention of breast cancer in women at high risk for the disease. The administration of TAM with DFMO is being considered for development by the National Cancer Institute as a potential drug regimen for the chemoprevention of breast carcinoma. METHODS The toxicity of DFMO in combination with TAM was evaluated in female Beagle dogs following 13 weeks of daily oral administration by capsule. Dose levels in milligrams per kilogram body weight per day were: 0 (vehicle control), 100 DFMO, 0.1 TAM, 1.0 TAM, 0.1 TAM + 100 DFMO and 1.0 TAM + 100 DFMO. RESULTS No mortalities occurred. Diarrhea was produced by TAM and vaginal discharge, due to reproductive tract lesions, was produced by both DFMO and TAM, either alone or in combination. DFMO decreased reticulocyte counts and TAM increased counts of mature neutrophils. DFMO alone resulted in lesions to the intestines and ovaries, and cornified epithelium of vagina and cervix. TAM produced cornified epithelium of vagina and cervix, and numerous lesions in the ovaries, fallopian tube, uterus, cervix and vagina which were likely due to an estrogen agonist effect. Coadministration of DFMO increased the incidence and/or severity of these reproductive tract lesions. Each compound alone produced ovarian atrophy, and antral follicles and corpora lutea were completely absent in the 1.0 TAM + 100 DFMO group. CONCLUSIONS Coadministration of DFMO and TAM resulted in additive toxicity involving the female reproductive system.
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Affiliation(s)
- A P Brown
- Department of Pharmacology, University of Illinois at Chicago, 60612-7353, USA
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Abstract
Ten years ago, the cloning and sequencing of a cDNA encoding the group I allergen of house-dust mites unequivocally determined that protein allergens may have biochemical functions in addition to their ability to bind IgE. Since this discovery, several groups have speculated that the biochemical activities of allergens, or substances associated with allergens, may be involved in their immunogenicity or allergenicity. This paper will focus on just one biochemical function, proteolytic activity, and will be illustrated by examples of our own work that we believe support the hypothesis that this category of molecules are endowed with the properties of proallergic adjuvants.
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Affiliation(s)
- C R Hewitt
- Immunotoxicology Laboratory, University of Leicester, UK.
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