1
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Affiliation(s)
- Christina Baleriola‐lucas
- Cornea and Contact Lens Research Unit School of Optometry, and Cooperative Research Centre for Eye Research and Technology, The University of New South Wales
| | - Mark Dp Willcox
- Cornea and Contact Lens Research Unit School of Optometry, and Cooperative Research Centre for Eye Research and Technology, The University of New South Wales
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2
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Chimutengwende-Gordon M, Pendegrass C, Blunn G. The in vivo effect of a porous titanium alloy flange with hydroxyapatite, silver and fibronectin coatings on soft-tissue integration of intraosseous transcutaneous amputation prostheses. Bone Joint J 2017; 99-B:393-400. [PMID: 28249981 PMCID: PMC5358203 DOI: 10.1302/0301-620x.99b3.bjj-2016-0360.r1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Accepted: 10/07/2016] [Indexed: 11/12/2022]
Abstract
Aims The Intraosseous Transcutaneous Amputation Prosthesis (ITAP)
may improve quality of life for amputees by avoiding soft-tissue
complications associated with socket prostheses and by improving
sensory feedback and function. It relies on the formation of a seal
between the soft tissues and the implant and currently has a flange
with drilled holes to promote dermal attachment. Despite this, infection
remains a significant risk. This study explored alternative strategies
to enhance soft-tissue integration. Materials and Methods The effect of ITAP pins with a fully porous titanium alloy flange
with interconnected pores on soft-tissue integration was investigated.
The flanges were coated with fibronectin-functionalised hydroxyapatite
and silver coatings, which have been shown to have an antibacterial
effect, while also promoting viable fibroblast growth in
vitro. The ITAP pins were implanted along the length of
ovine tibias, and histological assessment was undertaken four weeks
post-operatively. Results The porous titanium alloy flange reduced epithelial downgrowth
and increased soft-tissue integration compared with the current
drilled flange. The addition of coatings did not enhance these effects. Conclusion These results indicate that a fully porous titanium alloy flange
has the potential to increase the soft-tissue seal around ITAP and
reduce susceptibility to infection compared with the current design. Cite this article: Bone Joint J 2017;99-B:393–400.
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Affiliation(s)
- M Chimutengwende-Gordon
- Centre for Biomedical Engineering, Institute of Orthopaedics and Musculoskeletal Science, Division of Surgery and Interventional Science, University College London, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex, HA7 4LP, UK
| | - C Pendegrass
- Centre for Biomedical Engineering, Institute of Orthopaedics and Musculoskeletal Science, Division of Surgery and Interventional Science, University College London, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex, HA7 4LP, UK
| | - G Blunn
- Centre for Biomedical Engineering, Institute of Orthopaedics and Musculoskeletal Science, Division of Surgery and Interventional Science, University College London, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex, HA7 4LP, UK
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3
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Barnes RJ, Leung KT, Schraft H, Ulanova M. Chromosomalgfplabelling ofPseudomonas aeruginosausing a mini-Tn7transposon: application for studies of bacteria–host interactions. Can J Microbiol 2008; 54:48-57. [DOI: 10.1139/w07-118] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Analysis of bacterial interactions with host cells using multiple techniques is essential for studies on microbial pathogenesis and for the development of new antimicrobial therapies. Pseudomonas aeruginosa is an important opportunistic pathogen that can cause severe, often life-threatening pulmonary infections in individuals with impaired host defense mechanisms. Using a mini-Tn7 transposon delivery system, we have chromosomally labelled the strain P. aeruginosa PAK with a green fluorescent protein gene (gfp) and tested PAKgfp as a research tool for studies of bacteria–host interactions. We were able to reliably and rapidly measure the interactions of PAKgfp with A549 human lung epithelial cells by using flow cytometry, a fluorometric microplate reader-based assay, and fluorescence microscopy. With these analytical tools, we have demonstrated the adhesion of PAKgfp to the extracellular matrix protein fibronectin and the involvement of fibronectin in PAKgfp–A549 cell interactions. PAKgfp can be successfully used to explore the effects of various pharmacological compounds on P. aeruginosa – host cell interactions in both in vitro and in vivo systems, with potentially important medical applications.
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Affiliation(s)
- Rebecca J. Barnes
- Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, ON P7B 5E1, Canada
- Medical Sciences Division, Northern Ontario School of Medicine, West Campus, Lakehead University, 955 Oliver Road, Thunder Bay, ON P7B 5E1, Canada
| | - Kam Tin Leung
- Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, ON P7B 5E1, Canada
- Medical Sciences Division, Northern Ontario School of Medicine, West Campus, Lakehead University, 955 Oliver Road, Thunder Bay, ON P7B 5E1, Canada
| | - Heidi Schraft
- Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, ON P7B 5E1, Canada
- Medical Sciences Division, Northern Ontario School of Medicine, West Campus, Lakehead University, 955 Oliver Road, Thunder Bay, ON P7B 5E1, Canada
| | - Marina Ulanova
- Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, ON P7B 5E1, Canada
- Medical Sciences Division, Northern Ontario School of Medicine, West Campus, Lakehead University, 955 Oliver Road, Thunder Bay, ON P7B 5E1, Canada
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4
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Jesus LM, Abreu PRC, Almeida MC, Brito LC, Soares SF, de Souza DE, Bernardo LC, Fonseca AS, Bernardo-Filho M. A propolis extract and the labeling of blood constituents with technetium-99m. ACTA BIOLOGICA HUNGARICA 2006; 57:191-200. [PMID: 16841470 DOI: 10.1556/abiol.57.2006.2.6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Since ancient times propolis has been employed for many human purposes because to their favourable properties. Blood constituents labeled with technetium-99m (99mTc) have been used in nuclear medicine procedures. Some authors have reported that synthetic or natural drugs can interfere with the labeling of blood constituents with 99mTc. The aim of this work was to evaluate the action of a propolis extract on the labeling of blood elements with 99mTc. Samples of whole blood of male Wistar rats were incubated in sequence with an aqueous propolis extract at different concentrations, stannous chloride and 99mTc, as sodium pertechnetate. Blood samples were centrifuged to separate plasma and blood cells, soluble and insoluble fractions of plasma and blood cells were also separated after precipitation in trichloroacetic acid solution and centrifugation. The radioactivity was counted and the percentage of incorporated radioactivity (%ATI) for each fraction was calculated. The data obtained showed that the aqueous propolis extract used decreased significantly the %ATI in plasma proteins at higher concentration studied. Results suggest that at high concentration the constituents of this extract could alter the labeling of plasma proteins competing with same binding sites of the 99mTc on the plasma proteins or acting as antioxidant compounds.
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Affiliation(s)
- L M Jesus
- Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, Av. 28 de Setembro, 87, 50 andar, Vila Isabel, Rio de Janeiro, Brasil
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5
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Bavington C, Page C. Stopping Bacterial Adhesion: A Novel Approach to Treating Infections. Respiration 2005; 72:335-44. [PMID: 16088272 DOI: 10.1159/000086243] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Adhesion and colonization are prerequisites for the establishment of bacterial pathogenesis. The prevention of adhesion is an attractive target for the development of new therapies in the prevention of infection. Bacteria have developed a multiplicity of adhesion mechanisms commonly targeting surface carbohydrate structures, but our ability to rationally design effective antiadhesives is critically affected by the limitations of our knowledge of the human 'glycome' and of the bacterial function in relation to it. The potential for the future development of carbohydrate-based antiadhesives has been demonstrated by a significant number of in vitro and in vivo studies. Such therapies will be particularly relevant for infections of mucosal surfaces where topical application or delivery is possible.
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Affiliation(s)
- C Bavington
- GlycoMar Limited, European Centre for Marine Biotechnology, Dunstaffnage Marine Lab, Dunbeg, Oban, Argyll
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6
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Lima EAC, Diré G, Mattos DMM, Freitas RS, Gomes ML, de Oliveira MBN, Faria MVC, Jales RL, Bernardo-Filho M. Effect of an extract of cauliflower (leaf) on the labeling of blood elements with technetium-99m and on the survival of Escherichia coli AB1157 submitted to the treatment with stannous chloride. Food Chem Toxicol 2002; 40:919-23. [PMID: 12065213 DOI: 10.1016/s0278-6915(02)00065-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The labeling of red blood cells (RBC) with technetium-99m (99mTc) depends on a reducing agent and stannous chloride (SnCl(2)) and is widely utilized. This labeling may also be altered by drugs, and SnCl(2) reduces the survival of Escherichia coli cultures. Cauliflower (Brassica oleracea L. var. botrytis) is used in folk medicine and we evaluated its influence on (i) the labeling of blood elements with 99mTc, and (ii) on the survival of an E. coli strain. Blood was withdrawn from rats that drank the extract of cauliflower (15 days). Blood was incubated with SnCl(2) and with 99mTc, as sodium pertechnetate, centrifuged and plasma (P) and RBC were isolated. Samples of P and RBC were also precipitated, centrifuged and soluble and insoluble fractions isolated. E. coli culture was treated with SnCl(2) in the presence of cauliflower. The extract of cauliflower did not alter the fixation of 99mTc on blood fractions; however, it abolished the lethal effect of SnCl(2) on the E. coli culture. We suggest that the substances present in the extract of cauliflower probably, would have redox property with different mechanisms of action. The oxidant action of the substances of the extract would not be strong enough to oxidise the stannous ions altering the 99mTc-labeling. However, the referred substances could oxidise these ions sufficiently to protect the E. coli culture against the lethal effect of the stannous ion.
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Affiliation(s)
- E A C Lima
- Universidade do Estado do Rio de Janeiro, Instituto de Biologia Roberto Alcantara Gomes, Departamento de Biofísica e Biometria, Av. 28 de setembro, 87, Brazil
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7
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de Oliveira JF, Avila AS, Braga ACS, de Oliveira MBN, Boasquevisque EM, Jales RL, Cardoso VN, Bernardo-Filho M. Effect of extract of medicinal plants on the labeling of blood elements with Technetium-99m and on the morphology of red blood cells: I--a study with Paullinia cupana. Fitoterapia 2002; 73:305-12. [PMID: 12234573 DOI: 10.1016/s0367-326x(02)00073-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Drugs can alter the labeling and the morphology of red blood cells. As Paullinia cupana is used in popular medicine, we evaluated its influence on the labeling process using technetium-99m (Tc-99m). Blood was incubated with P. cupana, stannous chloride and Tc-99m. Samples were centrifuged and plasma (P) and blood cells (BC) were separated and precipitated with trichloroacetic acid. Soluble (SF) and insoluble fractions (IF) were isolated. The morphology of the blood cells was evaluated under an optical microscope. The results showed a significant (P = 0.05) decrease in the uptake of radioactivity for the RBC (97.93 +/- 0.74 to 36.90 +/- 4.71%), in IF-P and in IF-BC due to P. cupana extract. The study of the morphology of the RBC revealed alterations in the shape of these cells. We suggest that the P. cupana effect could be explained by an inhibition of the stannous and pertechnetate ions or oxidation of the stannous ion or by damages in the plasma membrane.
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Affiliation(s)
- J F de Oliveira
- Universidade do Estado do Rio de Janeiro, Instituto de Biologia Roberto Alcantara Gomes, Departamento de Biofísica e Biometria, Av. 28 de Setembro, 87, Rio de Janeiro, RJ 20551-030, Brazil
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8
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Araujo JGVC, Toledo VPCP, Guimarães TMPD, Bernardo-Filho M, Simal CJR, Mota LG, Diniz SOF, Cardoso VN. Technetium-99m labeling anti-amastigote polyclonal antibodies of Leishmania amazonensis. Nucl Med Biol 2002; 29:405-11. [PMID: 12031875 DOI: 10.1016/s0969-8051(02)00295-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Anti-amastigote polyclonal antibody (IgG) was incubated with solutions of stannous chloride and sodium borohidride. After that, 3.7 MBq of technetium-99m (99mTc) was added. A labeling yield of the antibody about 84% was obtained. After filtration of 99mTc-IgG, the radiochemical purity increased from 84 to 95%. The labeling of IgG with 99mTc did not modify the immunoreactivity of the antibody, since it was able to identify in vitro and in vivo the specific antigen of Leishmania amazonensis.
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Affiliation(s)
- J G V C Araujo
- Laboratório de Radioisótopos, Faculdade de Farmácia, UFMG, Brazil
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9
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Reiniger IW, de Oliveira JF, Caldeira-de-Araújo A, Bernardo-Filho M. Effect of Peumus boldus on the labeling of red blood cells and plasma proteins with technetium-99m. Appl Radiat Isot 1999; 51:145-9. [PMID: 10376326 DOI: 10.1016/s0969-8043(98)00200-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Peumus boldus is used in popular medicine in Brazil. The influence of Peumus boldus on the labeling of red blood cells and plasma proteins with 99mTc was studied. Stannous chloride and 99mTc pertechnetate were incubated with blood and a tincture of Peumus boldus. Aliquots of plasma and blood cells were isolated from the mixture and treated with trichloroacetic acid (TCA). After separation, analysis of the soluble and insoluble fractions showed a rapid uptake of the radioactivity by blood cells in the presence of the drug, whereas there was a slight decrease in the amount of 99mTc radioactivity in the TCA-insoluble fraction of plasma.
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Affiliation(s)
- I W Reiniger
- Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcântara Gomes, Universidade do Estado do Rio de Janeiro, Brazil
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10
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de Bentzmann S, Plotkowski C, Puchelle E. Receptors in the Pseudomonas aeruginosa adherence to injured and repairing airway epithelium. Am J Respir Crit Care Med 1996; 154:S155-62. [PMID: 8876535 DOI: 10.1164/ajrccm/154.4_pt_2.s155] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
In the normal respiratory tract, the airway epithelial surface is protected from pathogenic bacterial colonization by the mucociliary clearance. The mucins present in the gel mucus layer exhibit a high diversity of carbohydrate receptors that allow specific bacterial recognition followed by bacterial and mucus elimination. As soon as the mucociliary clearance mechanism is impaired, the bacterial attachment to mucins in association with mucus stasis represent critical pathways for bacterial colonization of the airway epithelium. Several sources of injury may damage the epithelial integrity and induce partial or complete epithelial shedding, exposing cellular receptors and unmasked extracellular matrix (ECM) components that can be recognized by bacterial adhesins. Laminin and type I and IV collagens represent sites of Pseudomonas aeruginosa attachment to the ECM components. During airway epithelium repair after injury, particularly in cystic fibrosis (CF), the repairing cells exhibit apical receptors such as asialylated gangliosides (asialo GM1) to which P. aeruginosa adheres. The identification of the different receptors for P. aeruginosa, present either on the ECM proteins or on the apical surface of the remodeled airway epithelium, particularly in repairing respiratory CF epithelial cells, is a prerequisite to further therapeutic strategies to prevent airway colonization by P. aeruginosa.
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Affiliation(s)
- S de Bentzmann
- INSERM U 314, URCA, Hôpital Maison Blanche, Reims, France
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11
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Plotkowski MC, Tournier JM, Puchelle E. Pseudomonas aeruginosa strains possess specific adhesins for laminin. Infect Immun 1996; 64:600-5. [PMID: 8550213 PMCID: PMC173807 DOI: 10.1128/iai.64.2.600-605.1996] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Pseudomonas aeruginosa is a major human pathogen known to infect tissues that have been previously damaged in some way. In wounded human respiratory tissues, P. aeruginosa cells were found attached to exposed basement membranes following epithelial denudation, suggesting that the affinity for extracellular matrix proteins may account for the bacterium's opportunistic character. By using microtiter wells coated with different P. aeruginosa strains, we demonstrated that laminin binds to both colonizing bacterial strains, isolated from asymptomatic carriers, and strains isolated from infected patients. Binding of soluble laminin to piliated P. aeruginosa PAK and to the nonpiliated isogenic mutant PAK/p--was shown to be saturable. Binding of laminin to the piliated PAK strain was not different from binding to th nonpiliated PAK/p--strain but was significantly higher than binding to the avirulent, nonpiliated PAK-N1 rpoN mutant. By transmission electron microscopy, we localized the laminin-binding sites on a loose material in the outermost layer of the bacteria. Western immunoblotting results suggested that 57- and 59-kDa nonpilus adhesins from the microbial outer membranes account for the binding of P. aeruginosa to laminin. We speculate that bacterial affinity for laminin may be of biological significance in the pathogenesis of P. aeruginosa infection of injured tissues.
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Affiliation(s)
- M C Plotkowski
- Department of Microbiology and Immunology, Universidade do Estado do Rio de Janeiro, Brazil
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