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Abstract
This chapter covers magnetic bead-based isolation and analysis of the smallest members of extracellular vesicles (EVs), the exosomes (30-150 nm), generally regarded to originate from the multivesicular bodies (MVBs). Also included, are descriptions of how to prepare samples prior to isolations. The magnetic bead-based isolation workflow is dramatically shortened both by omitting the pre-enrichment step and providing an option for a very short capture time. Three direct exosome isolation strategies are described: (1) "Specific and Direct," (2) "Semi Generic and Direct" and (3) "Generic and Direct" as well as exosome release from the magnetic beads. Detailed description of downstream exosome analysis is included covering flow cytometry, Western blot and electron microscopy. Finally, a description of exosome isolation from more complex starting material including urine and serum/plasma is discussed.
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Affiliation(s)
- Ketil W Pedersen
- Thermo Fisher Scientific, Ullernchausseen 52, PO Box 114, Smestad, 0379, Oslo, Norway.
| | - Bente Kierulf
- Thermo Fisher Scientific, Ullernchausseen 52, PO Box 114, Smestad, 0379, Oslo, Norway
| | - Axl Neurauter
- Thermo Fisher Scientific, Ullernchausseen 52, PO Box 114, Smestad, 0379, Oslo, Norway
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Fischer G, Neurauter A, Wieser L, Strohmenger HU, Nowak CN. Prediction of Countershock Success. Methods Inf Med 2018; 48:486-92. [DOI: 10.3414/me0580] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2008] [Accepted: 02/23/2009] [Indexed: 11/09/2022]
Abstract
Summary
Objectives: Spectral analysis of the ventricular fibrillation (VF) ECG has been used for predicting countershock success, where the Fast Fourier Transformation (FFT) is the standard spectral estimator. Autoregressive (AR) spectral estimation should compute the spectrum with less computation time. This study compares the predictive power and computational performance of features obtained by the FFT and AR methods.
Methods: In an animal model of VF cardiac arrest, 41 shocks were delivered in 25 swine. For feature parameter analysis, 2.5 s signal intervals directly before the shock and directly before the hands-off interval were used, respectively. Invasive recordings of the arterial pressure were used for assessing the outcome of each shock. For a proof of concept, a micro-controller program was implemented.
Results: Calculating the area under the receiver operating characteristic (ROC) curve (AUC), the results of the AR-based features called spectral pole power (SPP) and spectral pole power with dominant frequency (DF) weighing (SPPDF) yield better outcome prediction results (85 %; 89 %) than common parameters based on FFT calculation method (centroid frequency (CF), amplitude spectrum area (AMSA)) (72%; 78%) during hands-off interval. Moreover, the predictive power of the feature parameters during ongoing CPR was not invalidated by closed-chest compressions. The calculation time of the AR-based parameters was nearly 2.5 times faster than the FFT-based features.
Conclusion: Summing up, AR spectral estimators are an attractive option compared to FFT due to the reduced computational speed and the better outcome prediction. This might be of benefit when implementing AR prediction features on the microprocessor of a semi-automatic defibrillator.
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Vestad B, Llorente A, Neurauter A, Phuyal S, Kierulf B, Kierulf P, Skotland T, Sandvig K, Haug KBF, Øvstebø R. Size and concentration analyses of extracellular vesicles by nanoparticle tracking analysis: a variation study. J Extracell Vesicles 2017; 6:1344087. [PMID: 28804597 PMCID: PMC5533132 DOI: 10.1080/20013078.2017.1344087] [Citation(s) in RCA: 173] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 06/13/2017] [Indexed: 11/09/2022] Open
Abstract
Current methods for characterisation of extracellular vesicles (EVs) need further standardisation in order to obtain an acceptable level of data comparability. Size and concentration of EVs can be determined by nanoparticle tracking analysis (NTA). However, both the heterogeneity of EVs and the choice of instrument settings may cause an appreciable analytical variation. Intra-assay (within-day, n = 6) and inter-assay (day-to-day, n = 6) variations (coefficient of variation, % CV) of different preparations of EVs and artificial vesicles or beads were determined using two NanoSight NS500 instruments, located at different laboratories. All analyses were performed by the same operator. The effect of applying identical software settings or instrument-optimised settings for each sample type and instrument was also evaluated. Finally, the impact of different operators and the use of two different software versions were investigated. The intra-assay CVs were 1–12% for both EVs and artificial samples, measured on the same instrument. The overall day-to-day variation was similar for both instruments, ranging from 2% to 25%. However, significantly different results were observed between the two instruments using identical software settings. The effect of applying instrument-optimised settings reduced the mismatch between the instruments, resulting in little to no significant divergences. The impact of using different operators and software versions when analysing silica microspheres and microvesicles from monocytes using instrument-optimised settings on the same instrument did not contribute to significant variation compared to the overall day-to-day variation of one operator. Performance differences between two similar NTA instruments may display significant divergences in size and concentration measurements when analysing EVs, depending on applied instrument settings and technical conditions. The importance of developing a streamlined and standardised execution of analysis, as well as monitoring longitudinal variation parameters on both biological and synthetic samples, should be highlighted.
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Affiliation(s)
- Beate Vestad
- The Blood Cell Research Group, Department of Medical Biochemistry, Oslo University Hospital, Ullevål, Oslo, Norway.,Regional Research Network on Extracellular Vesicles, South-Eastern Norway Regional Health Authority, Norway
| | - Alicia Llorente
- Regional Research Network on Extracellular Vesicles, South-Eastern Norway Regional Health Authority, Norway.,Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital - The Norwegian Radium Hospital, Oslo, Norway.,Centre for Cancer Biomedicine, University of Oslo, Oslo, Norway
| | - Axl Neurauter
- Regional Research Network on Extracellular Vesicles, South-Eastern Norway Regional Health Authority, Norway.,Thermo Fisher Scientific, Life Sciences Solutions, Oslo, Norway
| | - Santosh Phuyal
- Regional Research Network on Extracellular Vesicles, South-Eastern Norway Regional Health Authority, Norway.,Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital - The Norwegian Radium Hospital, Oslo, Norway.,Centre for Cancer Biomedicine, University of Oslo, Oslo, Norway
| | - Bente Kierulf
- Regional Research Network on Extracellular Vesicles, South-Eastern Norway Regional Health Authority, Norway.,Thermo Fisher Scientific, Life Sciences Solutions, Oslo, Norway
| | - Peter Kierulf
- The Blood Cell Research Group, Department of Medical Biochemistry, Oslo University Hospital, Ullevål, Oslo, Norway.,Regional Research Network on Extracellular Vesicles, South-Eastern Norway Regional Health Authority, Norway
| | - Tore Skotland
- Regional Research Network on Extracellular Vesicles, South-Eastern Norway Regional Health Authority, Norway.,Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital - The Norwegian Radium Hospital, Oslo, Norway.,Centre for Cancer Biomedicine, University of Oslo, Oslo, Norway
| | - Kirsten Sandvig
- Regional Research Network on Extracellular Vesicles, South-Eastern Norway Regional Health Authority, Norway.,Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital - The Norwegian Radium Hospital, Oslo, Norway.,Centre for Cancer Biomedicine, University of Oslo, Oslo, Norway
| | - Kari Bente F Haug
- The Blood Cell Research Group, Department of Medical Biochemistry, Oslo University Hospital, Ullevål, Oslo, Norway.,Regional Research Network on Extracellular Vesicles, South-Eastern Norway Regional Health Authority, Norway
| | - Reidun Øvstebø
- The Blood Cell Research Group, Department of Medical Biochemistry, Oslo University Hospital, Ullevål, Oslo, Norway.,Regional Research Network on Extracellular Vesicles, South-Eastern Norway Regional Health Authority, Norway
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Oksvold MP, Kullmann A, Forfang L, Kierulf B, Li M, Brech A, Vlassov AV, Smeland EB, Neurauter A, Pedersen KW. Expression of B-cell surface antigens in subpopulations of exosomes released from B-cell lymphoma cells. Clin Ther 2016; 36:847-862.e1. [PMID: 24952935 DOI: 10.1016/j.clinthera.2014.05.010] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [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: 02/27/2014] [Revised: 05/16/2014] [Accepted: 05/16/2014] [Indexed: 12/24/2022]
Abstract
PURPOSE Exosomes are small (30- to 100-nm) vesicles secreted by all cell types in culture and found in most body fluids. A mean of 1 mL of blood serum, derived from healthy donors, contains approximately 10(12) exosomes. Depending on the disease, the number of exosomes can fluctuate. Concentration of exosomes in the bloodstream and all other body fluids is extremely high. Several B-cell surface antigens (CD19, CD20, CD22, CD23, CD24, CD37, CD40, and HLA-DR) and the common leukocyte antigen CD45 are interesting in terms of immunotherapy of hematologic malignant neoplasms. The established standard for exosome isolation is ultracentrifugation. However, this method cannot discriminate between exosome subpopulations and other nanovesicles. The main purpose of this study was to characterize CD81(+) and CD63(+) subpopulations of exosomes in terms of these surface markers after release from various types of B-cell lymphoma cell lines using an easy and reliable method of immunomagnetic separation. METHODS Western blotting, flow cytometry, and electron microscopy were used to compare the total preenriched extracellular vesicle (EV) pool to each fraction of vesicles after specific isolation, using magnetic beads conjugated with antibodies raised against the exosome markers CD63 and CD81. FINDINGS Magnetic bead-based isolation is a convenient method to study and compare subpopulations of exosomes released from B-cell lymphoma cells. The data indicated that the specifically isolated vesicles differed from the total preenriched EV pool. CD19, CD20, CD24, CD37, and HLA-DR, but not CD22, CD23, CD40, and CD45, are expressed on exosomes from B-cell lymphoma cell lines with large heterogeneity among the different B-cell lymphoma cell lines. Interestingly, these B-cell lymphoma-derived EVs are able to rescue lymphoma cells from rituximab-induced complement-dependent cytotoxicity. IMPLICATIONS Distribution of exosomes that contain CD19, CD20, CD24, CD37, and HLA-DR may intercept immunotherapy directed against these antigens, which is important to be aware of for optimal treatment. The use of an immunomagnetic separation platform enables easy isolation and characterization of exosome subpopulations for further studies of the exosome biology to understand the potential for therapeutic and diagnostic use.
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Affiliation(s)
- Morten P Oksvold
- Department of Immunology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway; Centre for Cancer Biomedicine, University of Oslo, Oslo, Norway
| | | | - Lise Forfang
- Department of Immunology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway; Centre for Cancer Biomedicine, University of Oslo, Oslo, Norway
| | | | - Mu Li
- Life Technologies AS, Oslo, Norway
| | - Andreas Brech
- Centre for Cancer Biomedicine, University of Oslo, Oslo, Norway
| | | | - Erlend B Smeland
- Department of Immunology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway; Centre for Cancer Biomedicine, University of Oslo, Oslo, Norway
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Abstract
Exosomes are here defined as extracellular vesicles (EVs) in the approximate size range of 30-100 nm in diameter, and are observed in most body fluids containing typical exosomal markers such as CD9, CD63, and CD81. Potential subpopulations of exosomes can be captured by targeting these markers using magnetic beads. Magnetic beads are versatile tools for exosome isolation and downstream analysis. Here, we describe the workflow of immuno magnetic isolation and analysis of exosomes by flow cytometry, Western immunoblotting, and electron microscopy.
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Affiliation(s)
- Morten P Oksvold
- Department of Immunology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
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Nowak CN, Neurauter A, Wieser L, Wenzel V, Abella B, Myklebust H, Steen PA, Strohmenger HU. Prediction of countershock success in patients using the autoregressive spectral estimation. Methods Inf Med 2011; 51:13-20. [PMID: 21643621 DOI: 10.3414/me10-01-0033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 01/29/2011] [Indexed: 11/09/2022]
Abstract
OBJECTIVES Ventricular fibrillation (VF) is a life-threatening cardiac arrhythmia and within of minutes of its occurrence, optimal timing of countershock therapy is highly warranted to improve the chance of survival. This study was designed to investigate whether the autoregressive (AR) estimation technique was capable to reliably predict countershock success in VF cardiac arrest patients. METHODS ECG data of 1077 countershocks applied to 197 cardiac arrest patients with out-of-hospital and in-hospital cardiac arrest between March 2002 and July 2004 were retrospectively analyzed. The ECG from the 2.5 s interval of the precountershock VF ECG was used for computing the AR based features Spectral Pole Power (SPP) and Spectral Pole Power with Dominant Frequency weighing (SPPDF) and Centroid Frequency (CF) and Amplitude Spectrum Area (AMSA) based on Fast Fourier Transformation (FFT). RESULTS With ROC AUC values up to 84.1% and diagnostic odds ratio up to 19.12 AR based features SPP and SPPDF have better prediction power than the FFT based features CF (80.5%; 6.56) and AMSA (82.1%; 8.79). CONCLUSIONS AR estimation based features are promising alternatives to FFT based features for countershock outcome when analyzing human data.
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Affiliation(s)
- C N Nowak
- Institute of Biomedical Engineering, University for Health Science, Medical Informatics and Technology, Eduard-Wallnöfer-Zentrum 1/G3, 6060 Hall in Tirol, Austria.
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Vieweg U, Liner M, Lühn M, Neurauter A, Blauth M, Schmoelz W. [Biomechanical study of a ventral stand-alone cage for the lumbar spine with and without additional posterior fixation]. Orthopade 2008; 37:587-91. [PMID: 18463845 DOI: 10.1007/s00132-008-1264-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM Biomechanical study to examine the stability of a stand-alone cage (SAC; Topaz, Ulrich Medizintechnik, Ulm) incorporating integrated anterior fixation with and without additional posterior fixation. METHOD Six human spinal specimens (L4/5) were loaded in a spine tester in the three main motion planes in the following states: (a) intact, (b) defect (nucleotomy), (c) SAC, (d) SAC+internal fixator (IF), and (e) SAC+translaminar facet screws (TFS). Facet joint translation (FJT) and range of motion (ROM) were measured and used to evaluate the stability of the tested states. RESULTS The SAC stabilized the segment in comparison to the intact (a) and defect-containing (b) segments. The most rigid fixation was found for SAC+IF compared with the other states (a, b, c, e). The ROM and FJT of the SAC with the additional IF (d) showed a significant higher stability in all three motion planes. All differences in ROM and FJT between the tested states were statistically significant (p<0.05) except for the FJT SAC and SAC+TFS. CONCLUSION The ventral Topaz SAC is a stable implant for the lumbar spine. Additional dorsal stabilization is an option to increase the stability.
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Affiliation(s)
- U Vieweg
- Abteilung für spezielle Wirbelsäulenchirurgie, Leopoldina-Krankenhaus, Schweinfurt, Germany
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Schjetne KW, Kullman A, Møller AS, Kierulf B, Lycke K, Karlsson M, Neurauter A. Highly pure, viable and functional intact human Natural Killer (NK) cells isolated in a single isolation step using Dynabeads® FlowCompTM Technology. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.676.8] [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: 11/11/2022]
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