1
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Arad E, Pedersen KB, Malka O, Mambram Kunnath S, Golan N, Aibinder P, Schiøtt B, Rapaport H, Landau M, Jelinek R. Staphylococcus aureus functional amyloids catalyze degradation of β-lactam antibiotics. Nat Commun 2023; 14:8198. [PMID: 38081813 PMCID: PMC10713593 DOI: 10.1038/s41467-023-43624-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 11/15/2023] [Indexed: 12/18/2023] Open
Abstract
Antibiotic resistance of bacteria is considered one of the most alarming developments in modern medicine. While varied pathways for bacteria acquiring antibiotic resistance have been identified, there still are open questions concerning the mechanisms underlying resistance. Here, we show that alpha phenol-soluble modulins (PSMαs), functional bacterial amyloids secreted by Staphylococcus aureus, catalyze hydrolysis of β-lactams, a prominent class of antibiotic compounds. Specifically, we show that PSMα2 and, particularly, PSMα3 catalyze hydrolysis of the amide-like bond of the four membered β-lactam ring of nitrocefin, an antibiotic β-lactam surrogate. Examination of the catalytic activities of several PSMα3 variants allowed mapping of the active sites on the amyloid fibrils' surface, specifically underscoring the key roles of the cross-α fibril organization, and the combined electrostatic and nucleophilic functions of the lysine arrays. Molecular dynamics simulations further illuminate the structural features of β-lactam association upon the fibril surface. Complementary experimental data underscore the generality of the functional amyloid-mediated catalytic phenomenon, demonstrating hydrolysis of clinically employed β-lactams by PSMα3 fibrils, and illustrating antibiotic degradation in actual S. aureus biofilms and live bacteria environments. Overall, this study unveils functional amyloids as catalytic agents inducing degradation of β-lactam antibiotics, underlying possible antibiotic resistance mechanisms associated with bacterial biofilms.
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Affiliation(s)
- Elad Arad
- Ilse Katz Institute (IKI) for Nanoscale Science and Technology, Ben Gurion University of the Negev, Beer Sheva, 8410501, Israel
- Department of Chemistry, Ben Gurion University of the Negev, Beer Sheva, 8410501, Israel
| | - Kasper B Pedersen
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark
| | - Orit Malka
- Department of Chemistry, Ben Gurion University of the Negev, Beer Sheva, 8410501, Israel
| | - Sisira Mambram Kunnath
- Ilse Katz Institute (IKI) for Nanoscale Science and Technology, Ben Gurion University of the Negev, Beer Sheva, 8410501, Israel
- Department of Chemistry, Ben Gurion University of the Negev, Beer Sheva, 8410501, Israel
| | - Nimrod Golan
- Department of Biology, Technion-Israel Institute of Technology, Haifa, 3200003, Israel
| | - Polina Aibinder
- Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben Gurion University of the Negev, Beer Sheva, 8410501, Israel
| | - Birgit Schiøtt
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark
| | - Hanna Rapaport
- Ilse Katz Institute (IKI) for Nanoscale Science and Technology, Ben Gurion University of the Negev, Beer Sheva, 8410501, Israel
- Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben Gurion University of the Negev, Beer Sheva, 8410501, Israel
| | - Meytal Landau
- Department of Biology, Technion-Israel Institute of Technology, Haifa, 3200003, Israel
- Centre for Structural Systems Biology (CSSB), and European Molecular Biology Laboratory (EMBL), Hamburg, 22607, Germany
| | - Raz Jelinek
- Ilse Katz Institute (IKI) for Nanoscale Science and Technology, Ben Gurion University of the Negev, Beer Sheva, 8410501, Israel.
- Department of Chemistry, Ben Gurion University of the Negev, Beer Sheva, 8410501, Israel.
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2
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Roeters SJ, Strunge K, Pedersen KB, Golbek TW, Bregnhøj M, Zhang Y, Wang Y, Dong M, Nielsen J, Otzen DE, Schiøtt B, Weidner T. Elevated concentrations cause upright alpha-synuclein conformation at lipid interfaces. Nat Commun 2023; 14:5731. [PMID: 37723164 PMCID: PMC10507035 DOI: 10.1038/s41467-023-39843-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 06/23/2023] [Indexed: 09/20/2023] Open
Abstract
The amyloid aggregation of α-synuclein (αS), related to Parkinson's disease, can be catalyzed by lipid membranes. Despite the importance of lipid surfaces, the 3D-structure and orientation of lipid-bound αS is still not known in detail. Here, we report interface-specific vibrational sum-frequency generation (VSFG) experiments that reveal how monomeric αS binds to an anionic lipid interface over a large range of αS-lipid ratios. To interpret the experimental data, we present a frame-selection method ("ViscaSelect") in which out-of-equilibrium molecular dynamics simulations are used to generate structural hypotheses that are compared to experimental amide-I spectra via excitonic spectral calculations. At low and physiological αS concentrations, we derive flat-lying helical structures as previously reported. However, at elevated and potentially disease-related concentrations, a transition to interface-protruding αS structures occurs. Such an upright conformation promotes lateral interactions between αS monomers and may explain how lipid membranes catalyze the formation of αS amyloids at elevated protein concentrations.
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Affiliation(s)
- Steven J Roeters
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark.
- Department of Anatomy and Neurosciences, Amsterdam UMC, Vrije Universiteit, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands.
| | - Kris Strunge
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark
| | - Kasper B Pedersen
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark
| | - Thaddeus W Golbek
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark
| | - Mikkel Bregnhøj
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark
| | - Yuge Zhang
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark
| | - Yin Wang
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark
| | - Mingdong Dong
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark
| | - Janni Nielsen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark
| | - Daniel E Otzen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark
| | - Birgit Schiøtt
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000, Aarhus C, Denmark
| | - Tobias Weidner
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark.
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3
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Empereur-Mot C, Pedersen KB, Capelli R, Crippa M, Caruso C, Perrone M, Souza PCT, Marrink SJ, Pavan GM. Automatic Optimization of Lipid Models in the Martini Force Field Using SwarmCG. J Chem Inf Model 2023. [PMID: 37279107 DOI: 10.1021/acs.jcim.3c00530] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
After two decades of continued development of the Martini coarse-grained force field (CG FF), further refinment of the already rather accurate Martini lipid models has become a demanding task that could benefit from integrative data-driven methods. Automatic approaches are increasingly used in the development of accurate molecular models, but they typically make use of specifically designed interaction potentials that transfer poorly to molecular systems or conditions different than those used for model calibration. As a proof of concept, here, we employ SwarmCG, an automatic multiobjective optimization approach facilitating the development of lipid force fields, to refine specifically the bonded interaction parameters in building blocks of lipid models within the framework of the general Martini CG FF. As targets of the optimization procedure, we employ both experimental observables (top-down references: area per lipid and bilayer thickness) and all-atom molecular dynamics simulations (bottom-up reference), which respectively inform on the supra-molecular structure of the lipid bilayer systems and on their submolecular dynamics. In our training sets, we simulate at different temperatures in the liquid and gel phases up to 11 homogeneous lamellar bilayers composed of phosphatidylcholine lipids spanning various tail lengths and degrees of (un)saturation. We explore different CG representations of the molecules and evaluate improvements a posteriori using additional simulation temperatures and a portion of the phase diagram of a DOPC/DPPC mixture. Successfully optimizing up to ∼80 model parameters within still limited computational budgets, we show that this protocol allows the obtainment of improved transferable Martini lipid models. In particular, the results of this study demonstrate how a fine-tuning of the representation and parameters of the models may improve their accuracy and how automatic approaches, such as SwarmCG, may be very useful to this end.
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Affiliation(s)
- Charly Empereur-Mot
- Department of Innovative Technologies, University of Applied Sciences and Arts of Southern Switzerland, Polo Universitario Lugano, Campus Est, Via la Santa 1, 6962 Lugano-Viganello, Switzerland
| | - Kasper B Pedersen
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Riccardo Capelli
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy
| | - Martina Crippa
- Politecnico di Torino, Department of Applied Science and Technology, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Cristina Caruso
- Politecnico di Torino, Department of Applied Science and Technology, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Mattia Perrone
- Politecnico di Torino, Department of Applied Science and Technology, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Paulo C T Souza
- Molecular Microbiology and Structural Biochemistry (MMSB, UMR 5086), CNRS & University of Lyon, 7 Passage du Vercors, 69007 Lyon, France
| | - Siewert J Marrink
- Molecular Dynamics, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Giovanni M Pavan
- Department of Innovative Technologies, University of Applied Sciences and Arts of Southern Switzerland, Polo Universitario Lugano, Campus Est, Via la Santa 1, 6962 Lugano-Viganello, Switzerland
- Politecnico di Torino, Department of Applied Science and Technology, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
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Jorgensen C, Pedersen KB, Ulmschneider MB, Schiøtt B, Searson PC. Towards a multiscale model of P-glycoprotein efflux. Biophys J 2023; 122:530a. [PMID: 36784747 DOI: 10.1016/j.bpj.2022.11.2810] [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] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
| | | | | | - Birgit Schiøtt
- Department of Chemistry, Aarhus University, Aarhus, Denmark
| | - Peter C Searson
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA
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Pedersen KB, Flores-Canales JC, Schiøtt B. Predicting molecular properties of α-synuclein using force fields for intrinsically disordered proteins. Proteins 2023; 91:47-61. [PMID: 35950933 PMCID: PMC10087257 DOI: 10.1002/prot.26409] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 06/17/2022] [Accepted: 07/12/2022] [Indexed: 12/29/2022]
Abstract
Independent force field validation is an essential practice to keep track of developments and for performing meaningful Molecular Dynamics simulations. In this work, atomistic force fields for intrinsically disordered proteins (IDP) are tested by simulating the archetypical IDP α-synuclein in solution for 2.5 μs. Four combinations of protein and water force fields were tested: ff19SB/OPC, ff19SB/TIP4P-D, ff03CMAP/TIP4P-D, and a99SB-disp/TIP4P-disp, with four independent repeat simulations for each combination. We compare our simulations to the results of a 73 μs simulation using the a99SB-disp/TIP4P-disp combination, provided by D. E. Shaw Research. From the trajectories, we predict a range of experimental observations of α-synuclein and compare them to literature data. This includes protein radius of gyration and hydration, intramolecular distances, NMR chemical shifts, and 3 J-couplings. Both ff19SB/TIP4P-D and a99SB-disp/TIP4P-disp produce extended conformational ensembles of α-synuclein that agree well with experimental radius of gyration and intramolecular distances while a99SB-disp/TIP4P-disp reproduces a balanced α-synuclein secondary structure content. It was found that ff19SB/OPC and ff03CMAP/TIP4P-D produce overly compact conformational ensembles and show discrepancies in the secondary structure content compared to the experimental data.
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Affiliation(s)
| | | | - Birgit Schiøtt
- Department of Chemistry, Aarhus University, Aarhus C, Denmark.,Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, Denmark
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6
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Strazdaite S, Roeters SJ, Sakalauskas A, Sneideris T, Kirschner J, Pedersen KB, Schiøtt B, Jensen F, Weidner T, Smirnovas V, Niaura G. Interaction of Amyloid-β-(1-42) Peptide and Its Aggregates with Lipid/Water Interfaces Probed by Vibrational Sum-Frequency Generation Spectroscopy. J Phys Chem B 2021; 125:11208-11218. [PMID: 34597059 DOI: 10.1021/acs.jpcb.1c04882] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [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
In this study, we use surface-sensitive vibrational sum-frequency generation (VSFG) spectroscopy to investigate the interaction between model lipid monolayers and Aβ(1-42) in its monomeric and aggregated states. Combining VSFG with atomic force microscopy (AFM) and thioflavin T (ThT) fluorescence measurements, we found that only small aggregates with probably a β-hairpin-like structure adsorbed to the zwitterionic lipid monolayer (DOPC). In contrast, larger aggregates with an extended β-sheet structure adsorbed to a negatively charged lipid monolayer (DOPG). The adsorption of small, initially formed aggregates strongly destabilized both monolayers, but only the DOPC monolayer was completely disrupted. We showed that the intensity of the amide-II' band in achiral (SSP) and chiral (SPP) polarization combinations increased in time when Aβ(1-42) aggregates accumulated at the DOPG monolayer. Nevertheless, almost no adsorption of preformed mature fibrils to DOPG monolayers was detected. By performing spectral VSFG calculations, we revealed a clear correlation between the amide-II' signal and the degree of amyloid aggregates (e.g., oligomers or (proto)fibrils) of various Aβ(1-42) structures. The calculations showed that only structures with a significant amyloid β-sheet content have a strong amide-II' intensity, in line with previous Raman studies. The combination of the presented results substantiates the amide-II(') band as a legitimate amyloid marker.
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Affiliation(s)
- S Strazdaite
- Department of Organic Chemistry, Center for Physical Sciences and Technology, Sauletekio Ave. 3, Vilnius LT-10257, Lithuania
| | - S J Roeters
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - A Sakalauskas
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Sauletekio 7, LT-10257 Vilnius, Lithuania
| | - T Sneideris
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Sauletekio 7, LT-10257 Vilnius, Lithuania
| | - J Kirschner
- Institute of Solid State Physics, TU Wien, Wiedner Hauptstrasse 8-10, 1040 Vienna, Austria
| | - K B Pedersen
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - B Schiøtt
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - F Jensen
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - T Weidner
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - V Smirnovas
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Sauletekio 7, LT-10257 Vilnius, Lithuania
| | - G Niaura
- Department of Organic Chemistry, Center for Physical Sciences and Technology, Sauletekio Ave. 3, Vilnius LT-10257, Lithuania
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Zeppelin T, Pedersen KB, Berglund NA, Periole X, Schiøtt B. Effect of palmitoylation on the dimer formation of the human dopamine transporter. Sci Rep 2021; 11:4164. [PMID: 33602981 PMCID: PMC7893171 DOI: 10.1038/s41598-021-83374-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 02/01/2021] [Indexed: 01/01/2023] Open
Abstract
The human dopamine transporter (hDAT) is one in three members of the monoamine transporter family (MAT). hDAT is essential for regulating the dopamine concentration in the synaptic cleft through dopamine reuptake into the presynaptic neuron; thereby controlling hDAT dopamine signaling. Dysfunction of the transporter is linked to several psychiatric disorders. hDAT and the other MATs have been shown to form oligomers in the plasma membrane, but only limited data exists on which dimeric and higher order oligomeric states are accessible and energetically favorable. In this work, we present several probable dimer conformations using computational coarse-grained self-assembly simulations and assess the relative stability of the different dimer conformations using umbrella sampling replica exchange molecular dynamics. Overall, the dimer conformations primarily involve TM9 and/or TM11 and/or TM12 at the interface. Furthermore, we show that a palmitoyl group (palm) attached to hDAT on TM12 modifies the free energy of separation for interfaces involving TM12, suggesting that S-palmitoylation may change the relative abundance of dimers involving TM12 in a biological context. Finally, a comparison of the identified interfaces of hDAT and palmitoylated hDAT to the human serotonin transporter interfaces and the leucine transporter interface, suggests similar dimer conformations across these protein family.
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Affiliation(s)
- Talia Zeppelin
- Department of Chemistry, Aarhus University, Aarhus C, Denmark
| | - Kasper B Pedersen
- Department of Chemistry, Aarhus University, Aarhus C, Denmark.,Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, Denmark
| | - Nils A Berglund
- Department of Chemistry, Aarhus University, Aarhus C, Denmark
| | - Xavier Periole
- Department of Chemistry, Aarhus University, Aarhus C, Denmark. .,School of Biological Sciences, University of Auckland & Canterbury, Auckland & Christchurch, New Zealand.
| | - Birgit Schiøtt
- Department of Chemistry, Aarhus University, Aarhus C, Denmark. .,Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C, Denmark.
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Hasific S, Oevrehus KA, Gerke O, Hallas J, Busk M, Lambrechtsen J, Urbonaviciene G, Roennow Sand NP, Nielsen JS, Diederichsen L, Pedersen KB, Mickley H, Rasmussen LM, Lindholt JS, Diederichsen A. 456Risk of arterial calcification by conventional vitamin K antagonist treatment. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz747.0115] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Vitamin K antagonists (VKA) are the most frequently prescribed oral anticoagulants worldwide although new oral anticoagulants (NOAC) have become an important alternative. VKA inhibits Vitamin K1 necessary to produce coagulation factors but also Vitamin K2, which is essential in the activation of matrix-Gla protein, thought to be a strong local inhibitor of arterial calcifications.
Purpose
The aim was to investigate, whether VKA treatment is associated with coronary artery calcification (CAC) in a population with no prior cardiovascular disease (CVD).
Methods
We collected data on cardiovascular risk factors and CAC scores from cardiac CT scans performed as part of clinical examinations (n=9,672) or research studies (n=14,166) in the period 2007–2017. Data on use of VKA and NOAC was obtained from the Danish National Health Service Prescription Database. The association between VKA treatment duration and categorized CAC score was investigated by ordered logistic regression while adjusting for covariates. The independent variables included in the model were: age, gender, smoking, body mass index (BMI), diabetes mellitus, hypertension, hypercholesterolemia and/or statin treatment, family history of CVD, estimated glomerular filtration rate, VKA treatment duration and NOAC treatment duration. The categorisation of CAC was: 0, 1–99, 100–399 and ≥400 AU, corresponding to no, mild, moderate and severe atherosclerotic plaque burden, respectively.
Results
The final study population consisted of 17,254 participants (median 67 years old, 75% males) with no prior CVD, of which 1,748 (10%) and 1,144 (7%) had been treated with VKA or NOAC, respectively. A longer duration of VKA treatment was associated with higher CAC categories (Figure). For each cumulative year of VKA treatment, the odds of being in a higher CAC category, i.e. having more severe atherosclerosis, increased (odds ratio (OR)=1.032, 95% CI 1.009–1.057). All traditional cardiovascular risk factors were also associated with CAC. In contrast, NOAC treatment duration was not associated with CAC category (OR=1.004, 95% CI 0.937–1.075). In a sensitivity analysis of patients without statin treatment (n=12,143), the association between VKA treatment and CAC category remained unchanged. There was no significant interaction between VKA treatment duration and age on CAC category.
Conclusion
Adjusted for cardiovascular risk factors, VKA treatment – in contrast to NOAC - is associated with more severe CAC. Additional studies are required to clarify the clinical importance of this association in terms of hard cardiovascular endpoints.
Acknowledgement/Funding
Novo Nordisk Foundation and Independent Research Fund Denmark
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Affiliation(s)
- S Hasific
- Odense University Hospital, Department of Cardiology, Odense, Denmark
| | - K A Oevrehus
- Odense University Hospital, Department of Cardiology, Odense, Denmark
| | - O Gerke
- Odense University Hospital, Department of Nuclear Medicine, Odense, Denmark
| | - J Hallas
- University of Southern Denmark, Clinical Pharmacology and Pharmacy, Odense, Denmark
| | - M Busk
- Lillebaelt Hospital, Department of Cardiology, Vejle, Denmark
| | - J Lambrechtsen
- Svendborg Hospital, Department of Cardiology, Svendborg, Denmark
| | - G Urbonaviciene
- Regional Hospital Central Jutland, Department of Cardiology, Silkeborg, Denmark
| | - N P Roennow Sand
- Sydvestjysk Hospital, Department of Cardiology, Esbjerg, Denmark
| | - J S Nielsen
- Odense University Hospital, DD2, Steno Diabetes Centre Odense, Odense, Denmark
| | - L Diederichsen
- Odense University Hospital, Department of Rheumatology, Odense, Denmark
| | - K B Pedersen
- Odense University Hospital, Department of Cardiology, Odense, Denmark
| | - H Mickley
- Odense University Hospital, Department of Cardiology, Odense, Denmark
| | - L M Rasmussen
- Odense University Hospital, Department of Clinical Biochemistry, Odense, Denmark
| | - J S Lindholt
- Odense University Hospital, Department of Cardiothoracic and Vascular Surgery, Odense, Denmark
| | - A Diederichsen
- Odense University Hospital, Department of Cardiology, Odense, Denmark
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Pedersen KB, Sjølie AK, Vestergaard AH, Andréasson S, Møller F. Fixation stability and implication for multifocal electroretinography in patients with neovascular age-related macular degeneration after anti-VEGF treatment. Graefes Arch Clin Exp Ophthalmol 2016; 254:1897-1908. [PMID: 27080862 DOI: 10.1007/s00417-016-3323-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Revised: 03/02/2016] [Accepted: 03/09/2016] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To quantify fixation stability in patients with neovascular age-related macular degeneration (nAMD) at baseline, 3 and 6 months after anti-vascular endothelial growth factor (anti-VEGF) treatment and furthermore asses the implications of an unsteady fixation for multifocal electroretinography (mfERG) measurements. METHODS Fifty eyes of 50 nAMD patients receiving intravitreal anti-VEGF treatment with either bevacizumab or ranibizumab and eight eyes of eight control subjects were included. Fixation stability measurements were performed with the Eye-Link eyetracking system and the retinal area in degrees2 (deg2) containing the 68 % most frequently used fixation points (RAF68) was calculated. MfERG P1 amplitude and implicit time were analyzed in six concentric rings and as a summed response. Patients were examined at baseline, 3 and 6 months. Four different mfERG recordings were performed for the control subjects to mimic an involuntary unstable fixation: normal central fixation, 2.4°, 4.8°, and 7.1° fixation instability. RESULTS For control subjects, a fixation instability of 2.4° (corresponding to the central hexagon) did not reduce mfERG ring amplitudes significantly, whereas 4.8° and 7.1° fixation instability reduced the amplitudes significantly in rings 1 and 2 (p < 0.001) as well as in the peripheral rings in the 7.1° instability condition (p < 0.001). Fixation stability improved non-significantly for patients at 3 and 6 months. The size of the retinal area of fixation was at baseline, 3 and 6 months negatively correlated to visual acuity (VA) (rbaseline = -0.65, r3 months = -0.60, and r6 months = -0.66 respectively, p < 0.001) and mfERG amplitudes of the three innermost rings (rbaseline = -0.29, p = 0.042, r3 months = -0.43, p = 0.003 and r6 months = -0.31, p = 0.042). The VA cutoff for a fixation area less than 5 deg2 (approximately the central hexagon) was 65, 77, and 68 ETDRS letters (corresponding a maximal Snellen equivalent of 0.31) at baseline, 3 and 6 months, respectively. CONCLUSIONS MfERG amplitudes in recordings of nAMD patients are at substantial risk of being reduced due to poor fixation as a large number of patients may use a fixation area of more than 5 deg2. Fixation monitoring during recording as well as interpretation of results should be performed with care, especially in patients with poor visual acuity.
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Affiliation(s)
- K B Pedersen
- Department of Ophthalmology, Rigshospitalet-Glostrup, Nordre Ringvej 57, 2600, Glostrup, Denmark.
| | - A K Sjølie
- Department of Ophthalmology, Odense University Hospital, 5000, Odense, Denmark
| | - A H Vestergaard
- Department of Ophthalmology, Odense University Hospital, 5000, Odense, Denmark
| | - S Andréasson
- Department of Ophthalmology, Lund University, 221 00, Lund, Sweden
| | - F Møller
- Department of Ophthalmology, Vejle Hospital, 7100, Vejle, Denmark
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Pedersen KB. Isolation and description of a haemolytic species of Neisseria (N. ovis) from cattle with infectious keratoconjunctivitis. Acta Pathol Microbiol Scand B Microbiol Immunol 2009; 80:135-9. [PMID: 4502347 DOI: 10.1111/j.1699-0463.1972.tb00140.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Nansen P, Flagstand T, Pedersen KB. Preparation of antisera to bovine immunoglobulin classes by immunization with agar-gel precipitates. Acta Pathol Microbiol Scand B Microbiol Immunol 2009; 79:459-65. [PMID: 4107467 DOI: 10.1111/j.1699-0463.1971.tb03795.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Pedersen KB, Froholm LO, Bovre K. Fimbriation and colony type of Moraxella bovis in relation to conjunctival colonization and development of keratoconjunctivitis in cattle. Acta Pathol Microbiol Scand B Microbiol Immunol 2009; 80:911-8. [PMID: 4509397 DOI: 10.1111/j.0365-5563.1973.tb00019.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Andersen K, Smith-Sørensen B, Pedersen KB, Hovig E, Myklebost O, Fodstad Ø, Mælandsmo GM. Interferon-gamma suppresses S100A4 transcription independently of apoptosis or cell cycle arrest. Br J Cancer 2003; 88:1995-2001. [PMID: 12799648 PMCID: PMC2741112 DOI: 10.1038/sj.bjc.6600998] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The S100A4 protein has been associated with increased metastatic capacity of cancer cells, and recent studies have suggested a correlation between the expression level of S100A4 and the prognostic outcome for patients with various types of cancer. The knowledge about the mechanisms underlying the metastasis-promoting effects is still limited, and the aim of the present study was to elucidate signal transduction pathways involved in the regulation of S100A4. After treatment of human carcinoma cells with interferon-gamma (IFN-gamma), we observed downregulation of S100A4 both at mRNA and protein levels. The effect was not dependent on IFN-gamma-induced apoptosis or IFN-gamma-mediated cell cycle arrest. Moreover, IFN-gamma-mediated decrease in mRNA stability could not account for the observed decrease in S100A4 transcript level. Finally, microarray analysis suggests ISGF3G, ETV5, ZNF133 and CEBPG as possible candidate genes involved in IFN-gamma-mediated repression of S100A4.
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Affiliation(s)
- K Andersen
- Department of Tumour Biology, The Norwegian Radium Hospital, Montebello, N-0310 Oslo, Norway
| | - B Smith-Sørensen
- Department of Tumour Biology, The Norwegian Radium Hospital, Montebello, N-0310 Oslo, Norway
| | - K B Pedersen
- Department of Tumour Biology, The Norwegian Radium Hospital, Montebello, N-0310 Oslo, Norway
| | - E Hovig
- Department of Tumour Biology, The Norwegian Radium Hospital, Montebello, N-0310 Oslo, Norway
| | - O Myklebost
- Department of Tumour Biology, The Norwegian Radium Hospital, Montebello, N-0310 Oslo, Norway
| | - Ø Fodstad
- Department of Tumour Biology, The Norwegian Radium Hospital, Montebello, N-0310 Oslo, Norway
| | - G M Mælandsmo
- Department of Tumour Biology, The Norwegian Radium Hospital, Montebello, N-0310 Oslo, Norway
- Department of Tumour Biology, The Norwegian Radium Hospital, Montebello, N-0310 Oslo, Norway. E-mail:
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Pedersen KB, Nesland JM, Fodstad Ø, Maelandsmo GM. Expression of S100A4, E-cadherin, alpha- and beta-catenin in breast cancer biopsies. Br J Cancer 2002; 87:1281-6. [PMID: 12439718 PMCID: PMC2408909 DOI: 10.1038/sj.bjc.6600624] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2002] [Revised: 08/18/2002] [Accepted: 09/04/2002] [Indexed: 01/13/2023] Open
Abstract
In 66 breast cancer biopsies, the expression of the Ca(2+)-binding protein S100A4, E-cadherin, alpha- and beta-catenin was examined by immunohistochemistry, and the results were related to clinical and pathological parameters. High levels of S100A4 were found to significantly correlate with histological grade (P=0.030) and loss of oestrogen receptor (P=0.046), but not to the time interval between surgery and development of distant metastasis (P=0.51) or to patient survival (P=0.89). Loss of E-cadherin expression, associated with altered cell-cell adhesion, showed a highly significant association to overall survival (P=0.020) and metastasis-free period (P=0.0052). In multivariate analysis, only lymph node involvement was a more significant predictor of patient demise. No association was found between expression of S100A4 and any single member of the cadherin-catenin complex, but a trend (P=0.053) towards reduced expression of one or several of these proteins and S100A4 immunoreactivity was observed. In conclusion, although our results suggest an association between S100A4 expression and an aggressive tumour phenotype, no relationship to overall survival was found. Deregulation of E-cadherin expression, however, was of high prognostic significance.
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Affiliation(s)
- K B Pedersen
- Department of Tumour Biology, The Norwegian Radium Hospital, Montebello, N-0310 Oslo, Norway
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Pedersen KB, Aarestrup FM, Jensen NE, Bager F, Jensen LB, Jorsal SE, Nielsen TK, Hansen HC, Meyling A, Wegener HC. The need for a veterinary antibiotic policy. Vet Rec 1999; 145:50-3. [PMID: 10458580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
The international recognition of the 'stable to table' approach to food safety emphasises the need for appropriate and safe use of antibiotics in animal production. An appropriate use of antibiotics for food animals will preserve the long-term efficacy of existing antibiotics, support animal health and welfare and limit the risk of transfer of antibiotic resistance to humans. Furthermore, it may promote consumer confidence in the veterinary use of antibiotics. In advancing these arguments, the authors of this article argue that there is a need for a visible and operational policy for veterinary use of antibiotics, paying particular attention to the policies that are being developed in Denmark.
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Ree AH, Bjørnland K, Brünner N, Johansen HT, Pedersen KB, Aasen AO, Fodstad O. Regulation of tissue-degrading factors and in vitro invasiveness in progression of breast cancer cells. Clin Exp Metastasis 1998; 16:205-15. [PMID: 9568638 DOI: 10.1023/a:1006584624061] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hormone-independent growth and invasiveness represent phenotypic properties acquired during early progression of breast cancer. We compared human mammary adenocarcinoma cells, MCF-7, which are estrogen-dependent and poorly metastatic, with the estrogen-independent and highly metastatic subline, MCF7/LCC1, with regard to expression of tissue-degrading factors of the matrix metalloproteinase (MMP)-and urokinase (uPA)-dependent degradative pathways, as well as for their in vitro invasive properties. Both cell lines showed low constitutive mRNA expression of the MMP inhibitor TIMP-1. Baseline expression of TIMP-2 mRNA was also very low in MCF-7 cells, whereas the MCF7/LCC1 level was much higher (approximately 10-fold). Furthermore, both cell lines revealed low constitutive capacity to migrate in an in vitro invasion assay. Treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA; 100 nM) induced the mRNAs for TIMP-1 as well as for MMP-1, MMP-9, the uPA receptor, and the uPA inhibitor PAI-1, amongst which only the responses of MMP-9 and PAI-1 were cell-specific. The mRNA levels of MMP-9 and PAI-1 were approximately 10-fold and approximately 15-fold higher in MCF7/LCC1 cells compared to MCF-7 cells. The secretion of immunoreactive PAI-1 was considerably elevated (> 20-fold) in TPA-treated MCF7/LCC1 cells, whereas the TPA-dependent level of 92-kDa MMP-9 was only approximately 2-fold higher in MCF7/LCC1 cells than in MCF-7 cells. In both cell lines treatment with TPA was associated with an increase (approximately 10-fold) in in vitro migration, which in the MCF7/LCC1 cells was significantly attenuated by a reconstituted basement membrane extract (Matrigel). These data suggest that TPA-responsive in vitro invasive properties that are probably associated with PAI-1 expression may co-vary with progression from hormone-dependent to -independent breast cancer.
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Affiliation(s)
- A H Ree
- Department of Tumor Biology, The Norwegian Radium Hospital, Institute of Medical Biochemistry, Oslo. a.h.ree.@dnr.uio.no
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Foged NT, Nielsen JP, Pedersen KB. Differentiation of toxigenic from nontoxigenic isolates of Pasteurella multocida by enzyme-linked immunosorbent assay. J Clin Microbiol 1988; 26:1419-20. [PMID: 3410955 PMCID: PMC266627 DOI: 10.1128/jcm.26.7.1419-1420.1988] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [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: 01/05/2023] Open
Abstract
An enzyme-linked immunosorbent assay (ELISA) was developed for the rapid and simple differentiation of toxigenic from nontoxigenic strains of Pasteurella multocida. The sandwich ELISA is based on two different murine monoclonal antibodies with specificity for the P. multocida toxin. The ELISA, which is now used as a routine test in Denmark, has several advantages compared with previously described biological tests.
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Affiliation(s)
- N T Foged
- National Veterinary Laboratory, Copenhagen V, Denmark
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Abstract
The dermonecrotic effect of purified Pasteurella multocida toxin (PMT) was studied sequentially in guinea pigs and rats. The skin reaction was initially an acute inflammatory reaction, with edema and emigration of neutrophils and a few eosinophils and diapedesis of some erythrocytes. Four hours after intracutaneous injection the vessels were congested and thrombocytes were focally attached to the endothelial wall. Twenty-four h after the injection the inflammatory reaction appeared more severe and venules and arterioles were thrombosed. Necrotic changes were seen in hair follicles and in striated muscle fibers. Crude extracts from P. multocida and Clostridium perfringens injected intracutaneously into guinea pigs induced skin lesions qualitatively similar to the lesions induced by the purified PMT, indicating that dermonecrotic bacterial toxins may share similar biochemical properties.
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Affiliation(s)
- F Elling
- University Institute of Pathological Anatomy, Copenhagen, Denmark
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Nielsen JP, Bisgaard M, Pedersen KB. Production of toxin in strains previously classified as Pasteurella multocida. Acta Pathol Microbiol Immunol Scand B 1986; 94:203-4. [PMID: 3739718 DOI: 10.1111/j.1699-0463.1986.tb03042.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
169 strains of P. multocida ssp. multocida, 24 strains of P. multocida ssp. septica, 22 strains of P. multocida ssp. gallicida, and 8 strains of P. avium and P. canis, respectively, were tested for toxin production in EBL-cell culture assay. Toxin production was only demonstrated in strains belonging to P. multocida ssp. multocida. Toxigenic strains were derived from pigs, calves, cats, dogs, rabbits and turkeys.
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Abstract
Six one-week-old piglets were pretreated with a 1% acetic acid solution for two days in one or both nostrils. Three piglets were not treated with acetic acid. Three days after treatment all nine piglets were inoculated in both nostrils with a toxigenic type D strain of Pasteurella multocida. Three piglets were killed seven days after inoculation; one died spontaneously 13 days after inoculation and the remaining pigs were killed at approximately 90 kg body weight, i.e., five to six months of age. All acetic acid-treated animals developed severe atrophy of the turbinates in the treated nostrils. Untreated nostrils were normal. The present results showed that toxigenic P. multocida can induce turbinate atrophy that persisted until 90 kg body weight when the lesions were similar to spontaneous atrophic rhinitis in pigs. The turbinate atrophy was not accompanied by inflammatory reaction, atrophy of other bone structures, or lesions in other organs. The experiment showed furthermore that toxigenic P. multocida may be present in the tonsils of control animals without causing turbinate atrophy. A pathogenesis for atrophic rhinitis in pigs is proposed.
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Madsen EB, Bisgaard M, Mutters R, Pedersen KB. Characterization of Pasteurella species isolated from lungs of calves with pneumonia. Can J Comp Med 1985; 49:63-7. [PMID: 3986681 PMCID: PMC1236119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
During routine bacteriological examination of pneumonic calf lungs it was experienced that many Pasteurella multocida-like isolates had a fermentation pattern different from what is generally accepted for P. multocida sensu stricto. Forty-one out of 50 strains selected for further investigation were phenotypically related and formed a group of indole-, mannitol-and sorbitol-negative P. multocida-like strains, which was tentatively designated taxon 13. Deoxyribonucleic acid/deoxyribonucleic acid hybridizations including both ornithine positive and ornithine negative strains of taxon 13 allowed the classification of the former as P. multocida biovar 6 and the latter as V factor independent strains of Haemophilus avium.
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Barfod K, Pedersen KB. Influence of vaccination of sows with Bordetella-Pasteurella vaccines on the occurrence of atrophic rhinitis among their offspring after experimental infection with Bordetella bronchiseptica and toxigenic Pasteurella multocida. Nord Vet Med 1984; 36:337-45. [PMID: 6531207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Experimental infections with Bordetella bronchiseptica and a toxigenic strain of Pasteurella multocida were carried out in newborn piglets from 25 sows. Severe progressive atrophic rhinitis corresponding to the natural disease was produced. The effect of vaccination of sows during pregnancy with two vaccines containing antigens from B. bronchiseptica and toxigenic P. multocida on the incidence of nasal lesions in the offspring was studied.
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Pedersen KB, Henrichsen J, Perch B. The bacteriology of endocarditis in slaughter pigs. Acta Pathol Microbiol Immunol Scand B 1984; 92:237-8. [PMID: 6516848 DOI: 10.1111/j.1699-0463.1984.tb02827.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Streptococcus suis was isolated from 11 (10 per cent) out of 107 cases of endocarditis in slaughter pigs from which bacteria of any kind were isolated. Seven of the isolates belonged to the capsular serotypes 1, 2 and 1/2. Four were non-typable owing to lack of capsule. The organism isolated most often was Erysipelothrix rhusiopathiae, which was found in 68 (64 per cent) cases.
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Abstract
The pathogenesis of atrophic rhinitis was studied in an experiment in which piglets were infected with a toxigenic type D Pasteurella multocida strain in the right half of the nasal cavity. Two days before inoculation the nasal mucosa on the right side had been subjected to mild irritation by intranasal instillation of a weak solution of acetic acid. The untreated (left) half of the nasal cavity served as an intrinsic control. Macroscopically, changes in the turbinates were already appreciable at 3 days p.i., and pronounced turbinate atrophy was noted at 7 days p.i. At 14 days p.i. deviation of the snout and almost complete turbinate atrophy was observed. The turbinates in the untreated half of the nasal cavity developed normally. Histologically, the changes were initially characterized by bone resorption mediated by an increased number of osteoclasts. Later osteoclasts were sparse, and there was an apparent disruption of osteoid synthesis. Ultrastructurally, the osteoblasts showed nuclear indentations and dilatation of the endoplasmic reticulum. Since no inflammatory reaction was observed, the hypothesis is advanced that atrophic rhinitis in pigs is caused by a P. multocida-produced factor which will stimulate bone resorption and suppress osteoid synthesis.
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Abstract
A total of 138 capsulated strains of streptococci were isolated from pigs with various infections, notably septicemia and bronchopneumonia. Biochemically all strains were similar, and 31 strains were serologically identical to the previously described groups R, S, and RS streptococci, provisionally designated Streptococcus suis types 1, 2, and 1/2 by Elliot. The remaining 107 strains could be divided into six new capsular serotypes of S. suis.
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Pedersen KB, Barfod K. Effect on the incidence of atrophic rhinitis of vaccination of sows with a vaccine containing Pasteurella multocida toxin. Nord Vet Med 1982; 34:293-302. [PMID: 7177813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Combined experimental infections with Bordetella bronchiseptica and either a toxigenic or a non-toxic strain of P. multocida were carried out in newborn specific pathogen free piglets born to 25 sows. Pigs inoculated with B. bronchiseptica and toxin-producing P. multocida developed severe progressive atrophic rhinitis corresponding to the natural disease. The effect of vaccination of sows with a toxin-containing P. multocida vaccine on the incidence of nasal lesions in the offspring was studied.
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Jensen PT, Pedersen KB. The influence of sow colostrum trypsin inhibitor on the immunoglobulin absorption in newborn piglets. Acta Vet Scand 1982; 23:161-8. [PMID: 7148597 PMCID: PMC8295770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The influence of sow colostrum trypsin inhibitor (SCTI) on the immunoglobulin absorption from the gut of 16 newborn colostrum-deprived piglets was investigated in a paired feeding experiment. Three times at 1 h intervals the piglets were fed an experimental diet consisting of sow milk, purified swine serum immunoglobulins containing agglutinins against Bordetella bronchiseptica, and purified SGTI (diet I) or saline (diet II). The serum concentrations of IgG, IgM, IgA, and antibodies for B. bronchiseptica were measured by single radial immunodiffusion and by a tube agglutination procedure and used to evaluate the immunoglobulin absorption. Four and 6 h after the first experimental meal, blood samples from the piglets given SGTI in their diet had a generally higher level of IgG, IgA and aggutinins against B. bronchiseptica than blood samples from the piglets d no SGTI. No real differences were found in the IgM levels. Although the piglets fed no SGTI all showed a considerable immunoglobulin absorption, the SCTI was found to have a statistically significant positive influence on the IgG and IgA absorption.
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Pedersen KB, Bitsch V, Knox B, Meyling A, Elling F, Sørensen KJ. High-fever syndrome in pigs. Vet Rec 1981; 109:537. [PMID: 7340091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Pedersen KB, Barfod K. The aetiological significance of Bordetella bronchiseptica and Pasteurella multocida in atrophic rhinitis of swine. Nord Vet Med 1981; 33:513-22. [PMID: 7335484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Experimental infection with either pure culture of Bordetella bronchiseptica or B. bronchiseptica and a toxin-producing strain of Pasteurella multocida was studied in newborn piglets from 26 sows. Pigs inoculated with B. bronchiseptica alone got mild lesions, whereas pigs inoculated with both organisms showed clinical and pathological signs of atrophic rhinitis, corresponding to the progressive natural diseases. The effect of vaccinating sows against B bronchiseptica during pregnancy was studied.
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Pedersen KB. Studies on a haemolytic substance in Yersinia enterocolitica. Acta Pathol Microbiol Scand B 1981; 89:211-4. [PMID: 6797238 DOI: 10.1111/j.1699-0463.1981.tb00178_89b.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Yersinia enterocolitica serotype O3 was found to produce a haemolytic substance which could be released from the bacterial cells by sonic disintegration. The substance was non-dialysable, thermolabile, antigenic, and sensitive to trypsin. Chromatographic studies indicated a high molecular weight. Erythrocytes from different mammalian species differed in sensitivity to the haemolytic substance. Y. enterocolitica serotypes O8 and O9 produced no haemolytic substance.
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Abstract
RS streptococci were isolated from pigs that died in an outbreak of septicemia and meningitis in a Danish herd of swine. Most of the affected pigs were 7-9 weeks old. Experimental inoculation of SPF pigs with a culture of the streptococci isolated from the brain of a pig that had died during the outbreak showed that the bacterium was pathogenic for pigs. Out of 35 8-15-week-old pigs inoculated, nine developed arthritis and one died in septicemia. At necropsy, four of the pigs were found to have endocarditis. Blood cultures from pigs with endocarditis were constantly positive throughout the experiment, i.e., until the pigs died 5-7 weeks after inoculation. In vivo loss of capsular antigen was observed. A human strain of R streptococci isolated from a case of septicemia was also shown to be pathogenic for pigs.
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Friis NF, Pedersen KB, Bloch B. Ureaplasma isolated from the respiratory tract of mink. Acta Vet Scand 1980; 21:134-6. [PMID: 6992547 PMCID: PMC8317701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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Pedersen KB, Winblad S, Bitsch V. Studies on the interaction between different O-serotypes of Yersinia enterocolitica and HeLa cells. Acta Pathol Microbiol Scand B 1979; 87B:141-5. [PMID: 375673 DOI: 10.1111/j.1699-0463.1979.tb02417.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Eighty strains of Yersinia enterocolitica were examined for their ability to invade HeLa cells. The following O-serotypes were found to be invasive: 1, 3, 4a, 4c, 5b, 8, 9, 15a, 18, 20, 21 and 22. Biochemically, these types are either indole-, aesculin-, and salicin-negative, or indole-positive but aesculin- and salicin-negative. Other serotypes of Y. enterocolitica did not invade HeLa cells. Biochemically, these non-invasive strains are indole-, aesculin- and salicin-positive. Also the non-sucrose-fermenting strains of O-serotypes 11 and 12 were non-invasive. The interaction with HeLa cells was not restricted to viable bacteria, since also bacterial cells inactivated by formalin or ultraviolet light could gain entrance to the HeLa cells. Heating of the bacteria to 100 degrees C for 30 min. completely inhibited their invasiveness. Monolayer cultures of porcine kidney cells were also invaded by strains which invaded HeLa cells.
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Abstract
Yersinia enterocolitica serotype 03 was isolated from the colon contents of 27 (4.5%) of 599 bacon pigs on slaughter. Two (1.7%) out of 115 dogs were positive by culture for this human-athogenic serotype of Y. enterocolitica. A number of other serotypes of Y. enterocolitica were also obtained both from porcine and canine enteric contents (4b, 5a, 6, 7, 11, 12, 15, 17, 19, 26b, and non-typeable strains). All these serotypes are supposedly non-pathogenic for man and may possibly originate from the microflora of the environment. Haemolysis on bovine blood agar was observed for strains belonging to O-serotype 3.
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Friis NF, Pedersen KB. Isolation of Mycoplasma bovoculi from cases of infectious bovine keratoconjunctivitis. Acta Vet Scand 1979; 20:51-9. [PMID: 443141 PMCID: PMC8322873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Five outbreaks of infectious bovine keratoconjunctivitis were examined for bacteria and mycoplasmas. Mycoplasma bovoculi was demonstrated in four of the five outbreaks. Other mycoplasmatales were represented by Ureaplasma in one sample. Moraxella bovis and Neisseria ovis were found in all the outbreaks, the former being present in the vast majority of the animals. Transmission experiments with Mycoplasma bovoculi and Moraxella bovis in combination were carried out on four young, colostrumdeprived calves. Mycoplasma bovoculi appeared to have an enhancing effect on the pathogenicity of Moraxella bovis.
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Jensen PT, Pedersen KB. Studies on immunoglobulins and trypsin inhibitor in colostrum and milk from sows and in serum of their piglets. Acta Vet Scand 1979; 20:60-72. [PMID: 108928 PMCID: PMC8322883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The concentrations of IgG, IgM, IgA and the specific sow colostrum trypsin inhibitor (SCTI) were measured by radial immunodiffusion in colostrum and milk samples from sows and in serum samples from their offspring during the suckling period. A clear time dependence was found for all the measured variates in both whey and serum. Statistically significant positive correlations were found between, on the one hand, concentrations of IgG and IgA, but not IgM, in sera from 39 suckling piglets 1 and 3 days old, and, on the other hand, concentrations of the same immunoglobulins and of the trypsin inhibitor in maternal colostrum (n = 7). Multiple regression analyses showed that at day 1 and day 3 the levels of both IgG and IgA in serum samples from the suckling piglets were positively influenced by both the SCTI and the IgG or IgA contents in maternal colostrum.
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Knox B, Askaa J, Basse A, Bitsch V, Eskildsen M, Mandrup M, Ottosen HE, Overby E, Pedersen KB, Rasmussen F. Congenital ataxia and tremor with cerebellar hypoplasia in piglets borne by sows treated with Neguvon vet. (metrifonate, trichlorfon) during pregnancy. Nord Vet Med 1978; 30:538-45. [PMID: 733482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In 1976--77 The State Veterinary Serum Laboratory received new-born pigs which had shown nervous disorders immediately after birth. In all the cases the sows had been treated with Nevugon vet. (metrifonate, trichlorfon) during pregnancy. In the majority of the affected litters the morbidity and lethality were 100 per cent. Analysis of the breeding data from some of the herds suggested that the period during which the fetuses are sensitive is rather narrow, i.e., approximately from day 45 to day 63. The disease was reproduced experimentally and it was concluded that oral treatment of pregnant sows with Neguvon vet. about the middle of the gestation period can result in severe nervous disorders in the piglets. Clinically the disease is characterized by ataxia and tremor, and corresponding to that there is a pronounced hypoplasia of the cerebellum and also a reduction in the size of the spinal cord.
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Pedersen KB, Barfod K. Effect of vaccination of sows with Bordetella bronchiseptica on the incidence of atrophic rhinitis in swine. Nord Vet Med 1977; 29:369-75. [PMID: 905119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Vaccination of pregnant sows with Bordetella bronchiseptica was performed in an SPF herd with clinical atrophic rhinitis. Agglutinins against the organism were induced in serum and colostrum by the vaccination. The antibody titres were generally higher in colostrum than in corresponding serum samples. The frequency at slaughter of turbinate atrophy (+, ++, +++) was lower among pigs from vaccinated sows (11%) than in pigs borne by unvaccinated sows (20%). In the control group a lower daily weight gain was observed in pigs with turbinate atrophy than in pigs with normal noses. The mean daily weight gain in pigs with turbinate atrophy borne by vaccinated sows was slightly lower than in pigs without atrophy of conchae, but the difference was not significant. A specific immunological prophylaxis might be an alternative to antibacterial treatment in herds where atrophic rhinitis is aetiologically related to B. bronchiseptica infection.
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Pedersen KB, Simesen MG. [Feed supplementation with selenium in relation to the vitamin E-selenium deficiency syndrome in pigs (author's transl)]. Nord Vet Med 1977; 29:161-5. [PMID: 866121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
After the addition of selenium to swine feed (max. 0.1 ppm) was legalized in Denmark in 1975, a marked reduction has occurred in the incidence of hepatosis dietetica (HD) in the material received at the State Veterinary Serum Laboratory for diagnostic examination, while the incidence of mulberry heart disease (MHD) appears to be unchanged (Table I). In a material collected before the addition of selenium to swine feed was permitted, the selenium content in liver and heart was found to be significantly lower in the pigs that had died of MHD than in normal pigs, but higher than in pigs that had died of HD (Table II). These observations tend to support the view that feed supplementation with selenium is more effective to prevent HD than MHD.
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46
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Pedersen KB. [Actinobacillus infections in swine (author's transl)]. Nord Vet Med 1977; 29:137-40. [PMID: 323819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Actinobacilli infections in pigs are relatively rare. Most cases were septicaemic in the first week of life. With increasing age manifestations after generalized infections were characteristic, such as arthritis, polyarthritis, endocarditis, nephritis, osteomyelitis and embolic pneumonia. Of 34 porcine strains 33 were identified as A. equuli and only one was identical with A. suis. The justification of retaining this species is discussed.
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Abstract
Seventeen strains of Yersinia enterocolitica were isolated on examination of the caecal contents from 100 bacon pigs at slaughter. In another material consisting of 222 pigs with various diseases, the bacterium was found in 12 cases. Three out of 40 dogs were positive for the bacterium. Seven of the porcine and one of the canine strains belonged to serotype O 3, which is a human pathogen.
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Abstract
Strain-dependent variations in the ability of Bordetella bronchiseptica to produce haemolysis on solid media exist. Haemolysis is strongest at an acid reaction and will not take place if the reaction is too alkaline. Peptone and glutamine inhibit haemolysis and favour growth. The vigorous growth rapidly produced an alkaline reaction which inhibits the haemolysis.
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Pedersen KB. The serology of Bordetella bronchiseptica isolated from pigs compared with strains from other animal species. Acta Pathol Microbiol Scand Suppl 1975; 83:590-4. [PMID: 1060364 DOI: 10.1111/j.1699-0463.1975.tb00142.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The serology of freshly isolated strains of Bordetella bronchiseptica from pigs and some other animal species was studied by the agglutination and agglutinin absorption tests. Differentiation was made between heat stable O-antigens and heat labile K-antigens. All the strains examined contained a common O-antigen (1). In addition, three heat stable antigens were detected. The heat labile antigens of freshly isolated strains were found to be very different. The major antigens 2 and 3 were not found in combination. A common weak K-antigen (1) was found in all strains. The pig strains were found to be serologically identical (0, 1, 2; K 1, 2). The same serotype was isolated from a rabbit. Another rabbit strain was found to be similar to a strain isolated from an SPF-rat (O, 1, 3; K 1, 3, 4). The antigenic pattern found in two cat strains was O 1, 3; K 1, 3. Typing of freshly isolated strains from pigs with monospecific factor sera confirmed that all the strains so far examined were serologically identical. This uniform serology hampers epidemiological studies of porcine bordetellosis by antigenic analysis. The occurrence of serologically different serotypes of B. bronchiseptica is of significance in the diagnostic bacteriology since the final diagnosis must be confirmed by a serological test.
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Simesen MG, Pedersen KB. Selenium determinations in Danish swine affected with hepatosis dietetica. Acta Vet Scand 1975; 16:137-9. [PMID: 1136902 PMCID: PMC8396000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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