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Farrell S, Bagcigil AF, Chaintoutis SC, Firth C, Aydin FG, Hare C, Maaland M, Mateus A, Vale AP, Windahl U, Damborg P, Timofte D, Singleton D, Allerton F. A multinational survey of companion animal veterinary clinicians: How can antimicrobial stewardship guidelines be optimised for the target stakeholder? Vet J 2024; 303:106045. [PMID: 38000694 DOI: 10.1016/j.tvjl.2023.106045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 10/03/2023] [Accepted: 11/20/2023] [Indexed: 11/26/2023]
Abstract
Antimicrobial stewardship initiatives are widely regarded as a cornerstone for ameliorating the global health impact of antimicrobial resistance. Within companion animal health, such efforts have largely focused on development and dissemination of antimicrobial stewardship guidelines (ASGs). However, there have been few attempts to understand veterinarian attitudes towards and knowledge of ASGs or to determine how awareness regarding ASGs might best be increased. An online survey regarding ASGs was formulated for veterinarians who treat companion animals. The survey was distributed across 46 European and associated countries between 12 January and 30 June, 2022. In total, 2271 surveys were completed, with 64.9% of respondents (n = 1474) reporting awareness and usage of at least one ASG. Respondents from countries with greater awareness of ASGs tended to report more appropriate use of antimicrobials (Spearman's rank coefficient = 0.6084, P ≤ 0.001), with respondents from countries with country-specific ASGs tending to score highest across both awareness and appropriate use domains. Respondents prioritised guidance around antimicrobial choice (82.0%, n = 1863), duration of treatment (66.0%, n = 1499), and dosage (51.9%, n = 1179) for inclusion in future ASGs, with 78.0% (n = 1776) of respondents preferring ASGs to be integrated into their patient management system. Awareness of ASGs and their use in companion animal veterinary practice appears to be greater than previously reported, with respondents tending to report antimicrobial prescription decision making broadly in line with current clinical recommendations. However, further initiatives aimed at maximising accessibility to ASGs both within countries and individual veterinary practices are recommended.
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Affiliation(s)
- S Farrell
- Department of Computer Science, Durham University, Durham, UK
| | - A F Bagcigil
- Department of Microbiology, Faculty of Veterinary Medicine, Istanbul University-Cerrahpaşa, Istanbul, Turkey
| | - S C Chaintoutis
- Diagnostic Laboratory, Department of Clinical Sciences, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, 11 Stavrou Voutyra str., Thessaloniki, Greece
| | - C Firth
- Unit of Veterinary Public Health and Epidemiology, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria
| | - F G Aydin
- Ankara University, Faculty of Veterinary Medicine, Department of Pharmacology and Toxicology, 06070 Altindag/Ankara, Turkey
| | - C Hare
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
| | - M Maaland
- Department of Production Animal Clinical Sciences, Norwegian University of Life Sciences, 4325 Sandnes, Norway
| | - A Mateus
- World Organisation for Animal Health, 12 Rue de Prony, 75017 Paris, France
| | - A P Vale
- School of Veterinary Medicine, University College Dublin, UCD Belfield, Dublin, Ireland
| | - U Windahl
- Swedish National Veterinary Institute, 75189 Uppsala, Sweden
| | - P Damborg
- Department of Veterinary and Animal Sciences, University of Copenhagen, Stigbøjlen 4, 1870 Frederiksberg, Denmark
| | - D Timofte
- Department of Veterinary Anatomy Physiology and Pathology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Leahurst Campus, Neston CH64 7TE, UK
| | - D Singleton
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, UK
| | - F Allerton
- Willows Veterinary Centre and Referral Service, part of Linnaeus Veterinary Limited, Highlands Road, Shirley, Solihull B90 4NH, UK.
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Scahill K, Jessen LR, Prior C, Singleton D, Foroutan F, Ferran AA, Arenas C, Bjørnvad CR, Lavy E, Allerton F, Weese JS, Allenspach K, Guardabassi L, Unterer S, Bodnárová T, Windahl U, Brennan ML, Werner M. Efficacy of antimicrobial and nutraceutical treatment for canine acute diarrhoea: A systematic review and meta-analysis for European Network for Optimization of Antimicrobial Therapy (ENOVAT) guidelines. Vet J 2024; 303:106054. [PMID: 38049062 DOI: 10.1016/j.tvjl.2023.106054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 11/02/2023] [Accepted: 11/29/2023] [Indexed: 12/06/2023]
Abstract
Systemic antimicrobial treatments are commonly prescribed to dogs with acute diarrhoea, while nutraceuticals (prebiotics, probiotics, and synbiotics) are frequently administered as an alternative treatment. The aim of this systematic review and meta-analysis was to assess the effectiveness of antimicrobials and nutraceutical preparations for treatment of canine acute diarrhoea (CAD). The results of this study will be used to create evidence-based treatment guidelines. PICOs (population, intervention, comparator, and outcome) were generated by a multidisciplinary expert panel taking into account opinions from stakeholders (general practitioners and dog owners). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was used to evaluate the certainty of the evidence. The systematic search yielded six randomised controlled trials (RCT) for antimicrobial treatment and six RCTs for nutraceutical treatment meeting the eligibility criteria. Categories of disease severity (mild, moderate, and severe) were created based on the presence of systemic signs and response to fluid therapy. Outcomes included duration of diarrhoea, duration of hospitalization, progression of disease, mortality, and adverse effects. High certainty evidence showed that antimicrobial treatment did not have a clinically relevant effect on any outcome in dogs with mild or moderate disease. Certainty of evidence was low for dogs with severe disease. Nutraceutical products did not show a clinically significant effect in shortening the duration of diarrhoea (based on very low to moderate certainty evidence). No adverse effects were reported in any of the studies.
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Affiliation(s)
- K Scahill
- University of Edinburgh, College of Medicine and Veterinary Medicine, Edinburgh EH16 4SB, UK; Evidensia Södra Djursjukhuset Kungens Kurva, Månskärarvägen 13, Kungens Kurva 14175, Sweden.
| | - L R Jessen
- Department of Veterinary Clinical Science, University of Copenhagen, 1870 Frederiksberg C, Denmark
| | - C Prior
- Willows Veterinary Centre and Referral Centre, Solihull B90 4NH, United Kingdom
| | - D Singleton
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, CH64 7TE, UK
| | - F Foroutan
- Faculty of Health Sciences, McMasters University, ON L8S 4L8, Canada
| | - A A Ferran
- INTHERES, Université de Toulouse, INRAE, ENVT, Toulouse 31076, France
| | - C Arenas
- Internal Medicine Service, AniCura Valencia Sur Hospital Veterinario, Valencia 46460, Spain; VetCT Teleconsulting, Cambridge CB3 0FA, UK
| | - C R Bjørnvad
- Department of Veterinary Clinical Science, University of Copenhagen, 1870 Frederiksberg C, Denmark
| | - E Lavy
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - F Allerton
- Willows Veterinary Centre and Referral Centre, Solihull B90 4NH, United Kingdom
| | - J S Weese
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON N1G2W1, Canada
| | - K Allenspach
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames 50010, IA, USA
| | - L Guardabassi
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark
| | - S Unterer
- Clinic for Small Animal Internal Medicine, Vetsuisse Faculty, University of Zurich, Zurich 8057, Switzerland
| | - T Bodnárová
- Veterinary Clinic Podebrady, Poděbrady 29001, Czech Republic
| | - U Windahl
- Department of Animal Health and Antimicrobial Strategies, National Veterinary Institute (SVA), SE-75189 Uppsala, Sweden
| | - M L Brennan
- Centre for Evidence-based Veterinary Medicine, The University of Nottingham, NG7 2QL, UK
| | - M Werner
- Clinic for Small Animal Internal Medicine, Vetsuisse Faculty, University of Zurich, Zurich 8057, Switzerland
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Green M, Lowrie M, Singleton D, Garosi L, McConnell K. Approach to initial management of canine generalised epileptic seizures in primary-care veterinary practices in the United Kingdom. J Small Anim Pract 2022; 63:801-808. [PMID: 36003061 DOI: 10.1111/jsap.13543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 06/06/2022] [Accepted: 07/07/2022] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To investigate how primary care clinicians in the UK approach initial management of canine generalised epileptic seizures, including factors potentially associated with prescription and choice of anti-seizure drugs (ASDs). MATERIALS AND METHODS Electronic health records concerning 3,150,713 consultations (917,373 dogs) were collected from 224 veterinary practices by the Small Animal Veterinary Surveillance Network. Free-text clinical narratives were reviewed to identify those consistent with generalised epileptic seizure activity, including only those recording the first presentation for seizures. Dogs older than 6 years were excluded. RESULTS Five hundred and seventeen cases were included. Sixty-seven dogs (13.0%) received anti-seizure drugs at first presentation; this was significantly more likely in dogs presented with cluster seizures (CS) (odds ratio 13.8, 95% confidence interval 7.3 to 26.1). Phenobarbital (n=36) and imepitoin (n=29) were the most frequently chosen anti-seizure drugs. Presentation for a single epileptic seizure occurred in 321 dogs; seven were prescribed anti-seizure drugs. Eighty-six dogs were presented with cluster seizures; 38 were prescribed anti-seizure drugs, most frequently imepitoin (n= 19) and phenobarbital (n=17). Of the dogs presenting with a single seizure and at least 6-month follow-up (n=165), 33 (20%) did not have subsequent seizures recorded. CLINICAL SIGNIFICANCE Primary care clinicians rarely prescribed anti-seizure drugs following a single epileptic seizure in accordance with International Veterinary Epilepsy Task Force recommendations. Less than half of dogs initially presenting with cluster seizures were prescribed anti-seizure drugs. Imepitoin was frequently selected in the treatment of cluster seizures despite no authorisation for this purpose. These findings may ultimately contribute to improved cohesion in the management of canine epileptic seizures between primary care and referral institutions.
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Affiliation(s)
- M Green
- Dovecote Veterinary Hospital, Derby, DE74 2LJ, UK
| | - M Lowrie
- Dovecote Veterinary Hospital, Derby, DE74 2LJ, UK
| | - D Singleton
- University of Liverpool, Liverpool, L69 3BX, UK
| | - L Garosi
- Vet Oracle Teleradiology, Norfolk, IP22 4ER, UK
| | - K McConnell
- Advanced Veterinary Diagnostic Imaging Specialists, Cheshire, SY14 8LQ, UK
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Singleton D. Book Review: Black Power Encyclopedia: From “Black Is Beautiful” to Urban Uprisings. RUSQ 2019. [DOI: 10.5860/rusq.58.3.7054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The Black Power Movement was largely a youth-led effort that broke from past thinking and methods of confronting American society and marked an important evolution in how African Americans continued their struggle in the wake of hard-fought landmark legislation such as the Civil Rights and Voting Rights Acts. There is no shortage of reference works on the Civil Rights Movement and African American history in general that include entries on facets of the Black Power Movement.
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Johnston W, Purcell C, Duffy C, Casey T, Greene BR, Singleton D, McGrath D, Caulfield B. 54 Investigating normal day to day variations in postural control in a healthy young population (age 18–40) using wii balance boards. Br J Sports Med 2015. [DOI: 10.1136/bjsports-2015-095573.54] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Harris AL, Buffa FM, Haider S, Bensaad K, McIntyre A, Lord S, Mehta S, Choudhry H, Favaro E, Ledaki I, Singleton D. Abstract BS02-1: Hypoxia metabolism in breast cancer – How to overcome resistance to anti-angiogenic therapy. Cancer Res 2013. [DOI: 10.1158/0008-5472.sabcs13-bs02-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background. Hypoxia is recognised to induce a multigene programme mainly via HIF1a and also HIF2a transcription factors. Bioinformatics analysis of multiple gene array data sets in breast cancer showed a core hypoxia response programme of approximately 90 genes associated with poor outcome independently of other factors. This core response was significantly over-expressed in triple receptor negative cancers. Additionally, microRNAs associated with hypoxia were shown to give additional worse prognosis associations (mir-210). mir-210 targeted the mitochondrial iron chaperone responsible for regulation of key enzymes in the Krebs cycle and showed an adaptive response to hypoxia involving switching off the mitochondrial metabolism.
Aims and methods. To assess in human breast cancer the hypoxia transcriptome we conducted gene microarray studies before and after 2 weeks of bevacizumab 15mg/kg single dose before neoadjuvant chemotherapy. This was correlated with imaging by DCE-MRI Ktrans analysis.
Results. The study showed that high Ktrans was an excellent predictor for the biological affect of VEGF inhibition and extensive gene induction occurred, including many components of the HIF pathway, but also glycogen metabolism and lipid metabolism.
We investigated these further in xenograft models to see which of the adaption pathways may be most important for survival under hypoxic conditions. We showed that induction of CA9, a key enzyme regulating extracellular pH, was critical for survival under anti-angiogenic therapy and blocking CA9 could synergise and also produce radiosensitivity. Reactivating mitochondria under hypoxic conditions induced by angiogenesis also showed additional anti-cancer benefits and is the basis now for a new phase I study in our department.
Additionally, surprisingly, induction of glycogen and lipid storage occurred and this was essential for survival on reoxygenation and for protection against free radical damage, which greatly increased when either pathway was inhibited.
We investigated, by bioinformatic approaches, the expression of 133 key enzymes in metabolism, showed that they were strongly associated with different subtypes of breast cancer, which may help in selection of patients for future intervention studies.
To additionally define the hypoxia transcription, we conducted RNA sequencing of MCF7 cells in normoxia and mild hypoxia. This revealed marked induction of many long non-coding RNAs, suppression of all transfer RNAs and induction of novel antisense RNAs.
Conclusions. Overall, therefore, although anti-angiogenic therapy alone is now withdrawn from clinical utility in breast cancer, the massive induction of hypoxic microenvironment and synergy with many other therapeutics, suggests that as new approach using induced essentiality should be reassessed in breast cancer.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr BS02-1.
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Affiliation(s)
- AL Harris
- Weatherall Institute of Molecular Medicine, Oxford, United Kingdom
| | - FM Buffa
- Weatherall Institute of Molecular Medicine, Oxford, United Kingdom
| | - S Haider
- Weatherall Institute of Molecular Medicine, Oxford, United Kingdom
| | - K Bensaad
- Weatherall Institute of Molecular Medicine, Oxford, United Kingdom
| | - A McIntyre
- Weatherall Institute of Molecular Medicine, Oxford, United Kingdom
| | - S Lord
- Weatherall Institute of Molecular Medicine, Oxford, United Kingdom
| | - S Mehta
- Weatherall Institute of Molecular Medicine, Oxford, United Kingdom
| | - H Choudhry
- Weatherall Institute of Molecular Medicine, Oxford, United Kingdom
| | - E Favaro
- Weatherall Institute of Molecular Medicine, Oxford, United Kingdom
| | - I Ledaki
- Weatherall Institute of Molecular Medicine, Oxford, United Kingdom
| | - D Singleton
- Weatherall Institute of Molecular Medicine, Oxford, United Kingdom
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Ivashchuk VD, Melnikov VN, Singleton D. Avoiding cosmological oscillating behavior forS-brane solutions with diagonal metrics. Int J Clin Exp Med 2005. [DOI: 10.1103/physrevd.72.103511] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Wu J, Hicks J, Ou C, Singleton D, Borillo J, Lou YH. Glomerulonephritis induced by recombinant collagen IV alpha 3 chain noncollagen domain 1 is not associated with glomerular basement membrane antibody: a potential T cell-mediated mechanism. J Immunol 2001; 167:2388-95. [PMID: 11490029 DOI: 10.4049/jimmunol.167.4.2388] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Glomerulonephritis is believed to result commonly from Ab-mediated glomerular injury. However, Ab-associated mechanisms alone cannot explain many cases of human glomerulonephritis. We developed a rat model of human anti-glomerular basement membrane (GBM) disease to investigate T cell and Ab response, and their associations with the disease. A single immunization of highly denatured recombinant mouse collagen IV alpha3 chain noncollagen domain 1 (rCol4alpha3NC1) induced severe glomerulonephritis in 100% of Wistar Kyoto rats, 33% of which died of this disease around day 35 postimmunization. The renal pathology demonstrated widespread glomerular damage and a mononuclear cell infiltration within the interstitial tissue. T cells from immunized rats responded not only to rCol4alpha3NC1, but also to isolated rat GBM. Sera Abs to rCol4alpha3NC1 were detectable in 100% of the rats, but only 20% of the rats had low levels of Ab to isolated rat GBM by Western blot, and none by immunofluorescence. Furthermore, IgG/M binding to or C3 deposition on endogenous GBM in immunized rats were not detected in most of the experimental rats, and showed no statistical correlation with disease severity. Additionally, no electronic dense deposition in the glomeruli was detected in all rats. Those data revealed a disassociation between the disease and anti-GBM Ab. T cell-mediated mechanisms, which are currently under our investigation, may be responsible for the glomerular disease.
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Affiliation(s)
- J Wu
- Department of Basic Sciences, Dental Branch, University of Texas Houston Health Science Center, Houston, TX 77030, USA
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Hubbard C, Singleton D, Rauch M, Jayasinghe S, Cafiso D, Castle D. The secretory carrier membrane protein family: structure and membrane topology. Mol Biol Cell 2000; 11:2933-47. [PMID: 10982391 PMCID: PMC14966 DOI: 10.1091/mbc.11.9.2933] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [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: 11/11/2022] Open
Abstract
Secretory carrier membrane proteins (SCAMPs) are integral membrane proteins found in secretory and endocytic carriers implicated to function in membrane trafficking. Using expressed sequence tag database and library screens and DNA sequencing, we have characterized several new SCAMPs spanning the plant and animal kingdoms and have defined a broadly conserved protein family. No obvious fungal homologue has been identified, however. We have found that SCAMPs share several structural motifs. These include NPF repeats, a leucine heptad repeat enriched in charged residues, and a proline-rich SH3-like and/or WW domain-binding site in the N-terminal domain, which is followed by a membrane core containing four putative transmembrane spans and three amphiphilic segments that are the most highly conserved structural elements. All SCAMPs are 32-38 kDa except mammalian SCAMP4, which is approximately 25 kDa and lacks most of the N-terminal hydrophilic domain of other SCAMPs. SCAMP4 is authentic as determined by Northern and Western blotting, suggesting that this portion of the larger SCAMPs encodes the functional domain. Focusing on SCAMP1, we have characterized its structure further by limited proteolysis and Western blotting with the use of isolated secretory granules as a uniformly oriented source of antigen and by topology mapping through expression of alkaline phosphatase gene fusions in Escherichia coli. Results show that SCAMP1 is degraded sequentially from the N terminus and then the C terminus, yielding an approximately 20-kDa membrane core that contains four transmembrane spans. Using synthetic peptides corresponding to the three conserved amphiphilic segments of the membrane core, we have demonstrated their binding to phospholipid membranes and shown by circular dichroism spectroscopy that the central amphiphilic segment linking transmembrane spans 2 and 3 is alpha-helical. In the intact protein, these segments are likely to reside in the cytoplasm-facing membrane interface. The current model of SCAMP1 suggests that the N and C termini form the cytoplasmic surface of the protein overlying a membrane core, which contains a functional domain located at the cytoplasmic interface with little exposure of the protein on the ectodomain.
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Affiliation(s)
- C Hubbard
- Department of Cell Biology, University of Virginia Health Sciences Center, Charlottesville, Virginia 22908, USA
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Sanchez AL, Singleton D, Walters B, Cobb J. Radionuclides in whole diets of people living near the Sellafield nuclear complex, UK. J Radioanal Nucl Chem 1997. [DOI: 10.1007/bf02063659] [Citation(s) in RCA: 3] [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: 11/29/2022]
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Heinel LA, Singleton D, Miller M, Frewin MB, Gudewicz PW. Monocyte adherence to the subendothelial basement membrane increases interleukin-8 gene expression and antigen release. Inflammation 1995; 19:517-27. [PMID: 8543367 DOI: 10.1007/bf01539132] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The emigration of peripheral blood monocytes into the interstitium allows for contact with a variety of surfaces which may provide signals important for monocyte function in both normal and inflammatory states. In the present study, we examined the effect of adherence to an endothelial cell-derived basement membrane and to collagen I, the major collagen of the interstitium, on monocyte release and gene expression of the potent chemotactic cytokine Interleukin-8 (IL-8). We further evaluated neutrophil chemotactic activity of the conditioned media containing antigenic IL-8 from monocytes adherent to these same surfaces. Elutriation-purified monocytes were adhered for 1 hour to plastic tissue culture wells either uncoated (PL) or coated with bovine serum albumin (BSA), collagen type I (C-I), or endothelial cell-derived basement membrane (BM). Following removal of nonadherent cells, monocytes were further incubated in a serum-free media for 18 hours in the presence or absence of lipopolysaccharide (IPS). Following 18 hrs of incubation there were significantly less monocytes remaining adherent to BM when compared to other surfaces tested. In the absence of LPS, adherent monocytes released significant amounts of IL-8 that was not surface specific. In the presence of LPS, monocytes adherent to BM released significantly more IL-8, when corrected for adherent cell number, than monocytes adherent to PL, BSA, or C-I. Conditioned media from adherent monocytes expressed IL-8 dependent neutrophil chemotactic activity that was not influenced by the surfaces tested. Northern blot analysis indicated greater induction for IL-8 mRNA by monocytes adhered to BM after 18 hrs in the presence of LPS. These results suggest that monocyte adherence to the subendothelial basement membrane provides a priming signal for the induction and secretion of the chemotactic cytokine IL-8 in response to inflammatory stimuli.
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Affiliation(s)
- L A Heinel
- Department of Physiology and Cell Biology, Albany Medical College, New York 12208, USA
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Gudewicz PW, Heinel LA, Stanton K, Singleton D, Frewin MB. Interaction of fibronectin (FN) cell binding fragments and interleukin-8 (IL-8) in regulating neutrophil chemotaxis. Biochem Biophys Res Commun 1994; 205:706-13. [PMID: 7999101 DOI: 10.1006/bbrc.1994.2723] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This study investigated the possible interaction of FN fragments in regulating IL-8-mediated neutrophil chemotaxis in vitro using Neuroprobe microchambers. Human neutrophil suspensions were incubated with purified FN fragments or an RGD-containing peptide and allowed to migrate in response to chemotactically active concentrations of human recombinant IL-8. The 120-kD fragment of FN containing the RGD sequence or an RGD peptide (GRGDSP) inhibited IL-8-mediated neutrophil chemotaxis; however, these RGD peptides did not inhibit neutrophil chemotaxis in response to other chemotactic agents. Furthermore, FN fragments not containing the RGD sequence had no effect on IL-8-mediated chemotaxis. These data suggest that directed migration of neutrophils in response to IL-8 is inhibited in the presence of cell-binding fragments of FN and may represent a local mechanism for terminating neutrophil migration at areas of tissue injury.
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Affiliation(s)
- P W Gudewicz
- Department of Physiology and Cell Biology, Albany Medical College, New York 12208
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Kadowaki T, Chen S, Hitomi M, Jacobs E, Kumagai C, Liang S, Schneiter R, Singleton D, Wisniewska J, Tartakoff AM. Isolation and characterization of Saccharomyces cerevisiae mRNA transport-defective (mtr) mutants. J Cell Biol 1994; 126:649-59. [PMID: 8045930 PMCID: PMC2120137 DOI: 10.1083/jcb.126.3.649] [Citation(s) in RCA: 139] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
To understand the mechanisms of mRNA transport in eukaryotes, we have isolated Saccharomyces cerevisiae temperature-sensitive (ts) mutants which accumulate poly(A)+ RNA in the nucleus at the restrictive temperature. A total of 21 recessive mutants were isolated and classified into 16 complementation groups. Backcrossed mRNA transport-defective strains from each complementation group have been analyzed. A strain which is ts for heat shock transcription factor was also analyzed since it also shows nuclear accumulation of poly(A)+ RNA at 37 degrees C. At 37 degrees C the mRNA of each mutant is characterized by atypically long polyA tails. Unlike ts pre-mRNA splicing mutants, these strains do not interrupt splicing of pre-mRNA at 37 degrees C; however four strains accumulate oversized RNA polymerase II transcripts. Some show inhibition of rRNA processing and a further subset of these strains is also characterized by inhibition of tRNA maturation. Several strains accumulate nuclear proteins in the cytoplasm when incubated at semipermissive temperature. Remarkably, many strains exhibit nucleolar fragmentation or enlargement at the restrictive temperature. Most strains show dramatic ultrastructural alterations of the nucleoplasm or nuclear membrane. Distinct mutants accumulate poly(A)+ RNA in characteristic patterns in the nucleus.
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Affiliation(s)
- T Kadowaki
- Institute of Pathology, Case Western Reserve University, Cleveland, Ohio 44106
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Abstract
There is a dynamic equilibrium between monomeric G-actin and polymeric F-actin microfilaments (MFs) in eucaryotic cells. We have previously shown that disruption of MFs with cytochalasin D (CD) induced beta-actin gene transcription, resulting in elevated levels of beta-actin mRNA and protein synthesis. CD also inhibited cell growth by arresting progression through the S phase of the cell cycle. These CD-induced responses were reversible since recovering cells progressed through the G2 phase and resumed normal growth while beta-actin mRNA and protein synthesis rapidly returned to control levels. In the present study, we show that the response of beta- and gamma-actin genes is due to the synthesis of a protein(s) acting at a 5' regulatory element that may be independent of or require sequences in addition to the serum response element (SRE). CD induces beta- and gamma-actin mRNA in a dose-dependent manner, reaching a maximum of 20-fold over control mRNA levels at 30 microM. beta- and gamma-Actin gene expression was also induced 5-fold by serum stimulation of quiescent murine erythroleukemia (MEL) cells, while combined treatment with serum and CD had an additive effect. Two protein synthesis inhibitors, cycloheximide and puromycin, blocked the CD-induced increase in beta-actin mRNA, in contrast to the serum-induced increase which is insensitive to inhibitors of protein synthesis. The rapid return of beta-actin mRNA to basal levels following CD removal did not require protein synthesis nor did it require progression through the G2 phase of the cell cycle. A vector containing the 5' end of the beta-actin gene linked to a CAT reporter responded to CD when transfected into MEL cells, localizing the responsive element to the 5' portion of the beta-actin gene. By contrast, a minimal 99-bp actin promoter-CAT construct containing a functional SRE did not respond to CD.
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Affiliation(s)
- C J Sympson
- Department of Biochemistry, University of Louisville School of Medicine, Kentucky 40292
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Singh N, Singleton D, Tartakoff AM. Anchoring and degradation of glycolipid-anchored membrane proteins by L929 versus by LM-TK- mouse fibroblasts: implications for anchor biosynthesis. Mol Cell Biol 1991; 11:2362-74. [PMID: 1826759 PMCID: PMC359988 DOI: 10.1128/mcb.11.5.2362-2374.1991] [Citation(s) in RCA: 17] [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: 12/28/2022] Open
Abstract
Although many cells anchor surface proteins via moieties that are sensitive to phosphatidylinositol-specific phospholipase C (PI-PLC), the anchor moieties of surface proteins of mouse L929 cells resist PI-PLC. By constructing stable hybrids between L929 and lymphoma cells that express glycolipid-anchored proteins in a PI-PLC-sensitive form, we show that PI-PLC resistance behaves as a recessive trait. Since putative mannolipid precursors of the lipid anchors bear alkali-labile substituents which make them resist PI-PLC, these observations are most simply interpreted by postulating that L929 lacks a critical anchor deacylase. Unlike the L929 cell line, two of its descendants, the LM cell line and its thymidine kinase-negative variant (LM-TK-), do not express glycolipid-anchored proteins on their surface. Moreover, unlike L929 cells, LM-TK- cells rapidly inactivate at least one lipid-anchored enzyme in a compartment sensitive to acidotropic amines and leupeptin. By fusion of LM-TK- cells to mouse Thy-1- lymphoma mutants and monitoring of surface expression of lipid-anchored proteins, we assign LM-TK- to lymphoma mutant complementation group H. This genetic assignment is matched by analysis of mannolipids of L929, LM-TK-, wild-type, and class H lymphoma mutant cells: striking similarities are seen between the two wild-type cells by contrast to the mutants. Since the differences pertain to lipids which have properties consistent with their being anchor precursors, we suggest that LM-TK- has a lesion in the synthesis of anchor precursor mannolipids.
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Affiliation(s)
- N Singh
- Institute of Pathology, Case Western Reserve University, Cleveland, Ohio 44106
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Holzman GB, Singleton D, Holmes TF, Maatsch JL. Initial pelvic examination instruction: the effectiveness of three contemporary approaches. Am J Obstet Gynecol 1977; 129:124-9. [PMID: 900173 DOI: 10.1016/0002-9378(77)90731-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Initial pelvic examination skills were taught to 38 second-year medical students who were assigned to one of three study groups. The cognitive posttest scores of all groups were nearly identical, but the students who had received training from professional simulated patients rated significantly better in psychomotor and interpersonal skills than did those who received simulated outpatient instruction by a gynecologist. Thirty-five per cent of the psychomotor and interpersonal ratings attained by the latter and 5 per cent of those attained by the former were marginal or inadequate. It was concluded that a program involving professional simulated patients is an effective method of teaching pelvic examination skills to beginning students.
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