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Heil J, Augath M, Kurtcuoglu V, Hohmann J, Bechstein WO, Olthof P, Schnitzbauer AA, Seebeck P, Schiesser M, Schläpfer M, Beck-Schimmer B, Schadde E. Assessment of liver function by gadoxetic acid avidity in MRI in a model of rapid liver regeneration in rats. HPB (Oxford) 2024; 26:521-529. [PMID: 38185541 DOI: 10.1016/j.hpb.2023.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/18/2023] [Accepted: 12/18/2023] [Indexed: 01/09/2024]
Abstract
BACKGROUND This animal study investigates the hypothesis of an immature liver growth following ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) by measuring liver volume and function using gadoxetic acid avidity in magnetic resonance imaging (MRI) in models of ALPPS, major liver resection (LR) and portal vein ligation (PVL). METHODS Wistar rats were randomly allocated to ALPPS, LR or PVL. In contrast-enhanced MRI scans with gadoxetic acid (Primovist®), liver volume and function of the right median lobe (=future liver remnant, FLR) and the deportalized lobes (DPL) were assessed until post-operative day (POD) 5. Liver functionFLR/DPL was defined as the inverse value of time from injection of gadoxetic acid to the blood pool-corrected maximum signal intensityFLR/DPL multiplied by the volumeFLR/DPL. RESULTS In ALPPS (n = 6), LR (n = 6) and PVL (n = 6), volumeFLR and functionFLR increased proportionally, except on POD 1. Thereafter, functionFLR exceeded volumeFLR increase in LR and ALPPS, but not in PVL. Total liver function was significantly reduced after LR until POD 3, but never undercuts 60% of its pre-operative value following ALPPS and PVL. DISCUSSION This study shows for the first time that functional increase is proportional to volume increase in ALPPS using gadoxetic acid avidity in MRI.
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Affiliation(s)
- Jan Heil
- Institute of Physiology, University of Zurich, Zurich, Switzerland; Goethe University Frankfurt, University Hospital, Department of General, Visceral, Transplant and Thoracic Surgery, Germany
| | - Mark Augath
- Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Joachim Hohmann
- Department of Radiology and Nuclear Medicine, Cantonal Hospital Winterthur, Winterthur, Switzerland; Medical Faculty, University of Basel, Basel, Switzerland
| | - Wolf O Bechstein
- Goethe University Frankfurt, University Hospital, Department of General, Visceral, Transplant and Thoracic Surgery, Germany
| | - Pim Olthof
- Department of Surgery, Erasmus MC, Rotterdam, the Netherlands; Department of Surgery, Amsterdam UMC, Amsterdam, the Netherlands
| | - Andreas A Schnitzbauer
- Goethe University Frankfurt, University Hospital, Department of General, Visceral, Transplant and Thoracic Surgery, Germany
| | - Petra Seebeck
- Zurich Integrative Rodent Physiology (ZIRP), University of Zurich, Zurich, Switzerland
| | - Marc Schiesser
- Chirurgisches Zentrum Zürich (CZZ), Klinik Hirslanden Zurich, Zurich, Switzerland; Chirurgie Zentrum Zentralschweiz (CZZ) Hirslanden St. Anna, Lucerne, Switzerland
| | - Martin Schläpfer
- Institute of Physiology, University of Zurich, Zurich, Switzerland; Institute of Anesthesiology, University Hospital of Zurich, University of Zurich, Zurich, Switzerland
| | - Beatrice Beck-Schimmer
- Institute of Physiology, University of Zurich, Zurich, Switzerland; Institute of Anesthesiology, University Hospital of Zurich, University of Zurich, Zurich, Switzerland
| | - Erik Schadde
- Institute of Physiology, University of Zurich, Zurich, Switzerland; Chirurgisches Zentrum Zürich (CZZ), Klinik Hirslanden Zurich, Zurich, Switzerland; Chirurgie Zentrum Zentralschweiz (CZZ) Hirslanden St. Anna, Lucerne, Switzerland; Department of Surgery, Rush University Medical Center Chicago, IL, USA.
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Boraschi A, Hafner M, Spiegelberg A, Kurtcuoglu V. Influence of age on the relation between body position and noninvasively acquired intracranial pulse waves. Sci Rep 2024; 14:5493. [PMID: 38448614 PMCID: PMC10918064 DOI: 10.1038/s41598-024-55860-6] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 02/28/2024] [Indexed: 03/08/2024] Open
Abstract
The capacitive measurement of the head's dielectric properties has been recently proposed as a noninvasive method for deriving surrogates of craniospinal compliance (CC), a parameter used in the evaluation of space-occupying neurological disorders. With the higher prevalence of such disorders in the older compared to the younger population, data on the head's dielectric properties of older healthy individuals would be of particularly high value before assessing pathologic changes. However, so far only measurements on young volunteers (< 30 years) were reported. In the present study, we have investigated the capacitively obtained electric signal known as W in older healthy individuals. Thirteen healthy subjects aged > 60 years were included in the study. W was acquired in the resting state (supine horizontal position), and during head-up and head-down tilting. AMP, the peak-to-valley amplitude of W related to cardiac action, was extracted from W. AMP was higher in this older cohort compared to the previously investigated younger one (0°: 5965 ± 1677 arbitrary units (au)). During head-up tilting, AMP decreased (+ 60°: 4446 ± 1620 au, P < 0.001), whereas it increased during head-down tilting (- 30°: 7600 ± 2123 au, P < 0.001), as also observed in the younger cohort. Our observation that AMP, a metric potentially reflective of CC, is higher in the older compared to the younger cohort aligns with the expected decrease of CC with age. Furthermore, the robustness of AMP is reinforced by the consistent relative changes observed during tilt testing in both cohorts.
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Affiliation(s)
- Andrea Boraschi
- The Interface Group, Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Matthias Hafner
- The Interface Group, Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Andreas Spiegelberg
- The Interface Group, Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
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Agarwal N, Lewis LD, Hirschler L, Rivera LR, Naganawa S, Levendovszky SR, Ringstad G, Klarica M, Wardlaw J, Iadecola C, Hawkes C, Octavia Carare R, Wells J, Bakker EN, Kurtcuoglu V, Bilston L, Nedergaard M, Mori Y, Stoodley M, Alperin N, de Leon M, van Osch MJ. Current Understanding of the Anatomy, Physiology, and Magnetic Resonance Imaging of Neurofluids: Update From the 2022 "ISMRM Imaging Neurofluids Study group" Workshop in Rome. J Magn Reson Imaging 2024; 59:431-449. [PMID: 37141288 PMCID: PMC10624651 DOI: 10.1002/jmri.28759] [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] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/18/2023] [Accepted: 04/18/2023] [Indexed: 05/05/2023] Open
Abstract
Neurofluids is a term introduced to define all fluids in the brain and spine such as blood, cerebrospinal fluid, and interstitial fluid. Neuroscientists in the past millennium have steadily identified the several different fluid environments in the brain and spine that interact in a synchronized harmonious manner to assure a healthy microenvironment required for optimal neuroglial function. Neuroanatomists and biochemists have provided an incredible wealth of evidence revealing the anatomy of perivascular spaces, meninges and glia and their role in drainage of neuronal waste products. Human studies have been limited due to the restricted availability of noninvasive imaging modalities that can provide a high spatiotemporal depiction of the brain neurofluids. Therefore, animal studies have been key in advancing our knowledge of the temporal and spatial dynamics of fluids, for example, by injecting tracers with different molecular weights. Such studies have sparked interest to identify possible disruptions to neurofluids dynamics in human diseases such as small vessel disease, cerebral amyloid angiopathy, and dementia. However, key differences between rodent and human physiology should be considered when extrapolating these findings to understand the human brain. An increasing armamentarium of noninvasive MRI techniques is being built to identify markers of altered drainage pathways. During the three-day workshop organized by the International Society of Magnetic Resonance in Medicine that was held in Rome in September 2022, several of these concepts were discussed by a distinguished international faculty to lay the basis of what is known and where we still lack evidence. We envision that in the next decade, MRI will allow imaging of the physiology of neurofluid dynamics and drainage pathways in the human brain to identify true pathological processes underlying disease and to discover new avenues for early diagnoses and treatments including drug delivery. Evidence level: 1 Technical Efficacy: Stage 3.
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Affiliation(s)
- Nivedita Agarwal
- Neuroradiology Unit, Scientific Institute IRCCS E. Medea, Bosisio Parini, Italy
| | - Laura D. Lewis
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Lydiane Hirschler
- C.J. Gorter MRI Center, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Leonardo Rivera Rivera
- Wisconsin Alzheimer’s Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Shinji Naganawa
- Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | | | - Geir Ringstad
- Department of Radiology, Oslo University Hospital Rikshospitalet, Oslo, Norway
- Department of Geriatrics and Internal Medicine, Sorlandet Hospital, Arendal, Norway
| | - Marijan Klarica
- Department of Pharmacology and Croatian Institute of Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Joanna Wardlaw
- Centre for Clinical Brain Sciences and UK Dementia Research Institute Centre, University of Edinburgh, Edinburgh, UK
| | - Costantino Iadecola
- Department of Pharmacology and Croatian Institute of Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Cheryl Hawkes
- Biomedical and Life Sciences, Lancaster University, Lancaster, UK
| | | | - Jack Wells
- UCL Centre for Advanced Biomedical Imaging, University College of London, London, UK
| | - Erik N.T.P. Bakker
- Biomedical Engineering and Physics, Amsterdam UMC, University of Amsterdam, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | | | - Lynne Bilston
- Neuroscience Research Australia and UNSW Medicine, Sydney, Australia
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York, USA
- Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
| | - Yuki Mori
- Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
| | - Marcus Stoodley
- Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, Australia
- Department of Neurosurgery, Macquarie University Hospital, Sydney, Australia
| | - Noam Alperin
- Department of Radiology and Biomedical Engineering, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Mony de Leon
- Weil Cornell Medicine, Department of Radiology, Brain Health Imaging Institute, New York City, New York, USA
| | - Matthias J.P. van Osch
- C.J. Gorter MRI Center, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
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Abeken J, de Zelicourt D, Kurtcuoglu V. Incorporating Unresolved Stresses in Blood Damage Modeling: Energy Dissipation More Accurate Than Reynolds Stress Formulation. IEEE Trans Biomed Eng 2024; 71:563-573. [PMID: 37643096 DOI: 10.1109/tbme.2023.3309338] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
OBJECTIVE Reynolds Averaged Navier Stokes (RANS) models are often used as the basis for modeling blood damage in turbulent flows. To predict blood damage by turbulence stresses that are not resolved in RANS, a stress formulation that represents the corresponding scales is required. Here, we compare two commonly employed stress formulations: a scalar stress representation that uses Reynolds stresses as a surrogate for unresolved fluid stresses, and an effective stress formulation based on energy dissipation. METHODS We conducted unsteady RANS simulations of the CentriMag blood pump with three different closure models and a Large Eddy Simulation (LES) for reference. We implemented both stress representations in all models and compared the resulting total stress distributions in Eulerian and Lagrangian frameworks. RESULTS The Reynolds-stress-based approach overestimated the contribution of unresolved stresses in RANS, with differences between closure models of up to several orders of magnitude. With the dissipation-based approach, the total stresses predicted with RANS deviated by about 50% from the LES reference, which was more accurate than only considering resolved stresses. CONCLUSION The Reynolds-stress-based formulation proved unreliable for estimating scalar stresses in our RANS simulations, while the dissipation-based approach provided an accuracy improvement over simply neglecting unresolved stresses. SIGNIFICANCE Our results suggest that dissipation-based inclusion of unresolved stresses should be the preferred choice for blood damage modeling in RANS.
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Faivre A, Dissard R, Kuo W, Verissimo T, Legouis D, Arnoux G, Heckenmeyer C, Fernandez M, Tihy M, Rajaram RD, Delitsikou V, Le NA, Spingler B, Mueller B, Shulz G, Lindenmeyer M, Cohen C, Rutkowski JM, Moll S, Scholz CC, Kurtcuoglu V, de Seigneux S. Evolution of hypoxia and hypoxia-inducible factor asparaginyl hydroxylase regulation in chronic kidney disease. Nephrol Dial Transplant 2023; 38:2276-2288. [PMID: 37096392 PMCID: PMC10539236 DOI: 10.1093/ndt/gfad075] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Indexed: 04/26/2023] Open
Abstract
BACKGROUND The roles of hypoxia and hypoxia inducible factor (HIF) during chronic kidney disease (CKD) are much debated. Interventional studies with HIF-α activation in rodents have yielded contradictory results. The HIF pathway is regulated by prolyl and asparaginyl hydroxylases. While prolyl hydroxylase inhibition is a well-known method to stabilize HIF-α, little is known about the effect asparaginyl hydroxylase factor inhibiting HIF (FIH). METHODS We used a model of progressive proteinuric CKD and a model of obstructive nephropathy with unilateral fibrosis. In these models we assessed hypoxia with pimonidazole and vascularization with three-dimensional micro-computed tomography imaging. We analysed a database of 217 CKD biopsies from stage 1 to 5 and we randomly collected 15 CKD biopsies of various severity degrees to assess FIH expression. Finally, we modulated FIH activity in vitro and in vivo using a pharmacologic approach to assess its relevance in CKD. RESULTS In our model of proteinuric CKD, we show that early CKD stages are not characterized by hypoxia or HIF activation. At late CKD stages, some areas of hypoxia are observed, but these are not colocalizing with fibrosis. In mice and in humans, we observed a downregulation of the HIF pathway, together with an increased FIH expression in CKD, according to its severity. Modulating FIH in vitro affects cellular metabolism, as described previously. In vivo, pharmacologic FIH inhibition increases the glomerular filtration rate of control and CKD animals and is associated with decreased development of fibrosis. CONCLUSIONS The causative role of hypoxia and HIF activation in CKD progression is questioned. A pharmacological approach of FIH downregulation seems promising in proteinuric kidney disease.
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Affiliation(s)
- Anna Faivre
- Department of Medicine and Cell physiology and Metabolism, University of Geneva, Geneva, Switzerland
- Service of Nephrology, Department of Medicine, Geneva University Hospitals, Geneva, Switzerland
| | - Romain Dissard
- Department of Medicine and Cell physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Willy Kuo
- Institute of Physiology, University of Zurich, Zurich, Switzerland
- National Centre of Competence in Research, Kidney. CH, University of Zurich, Zurich, Switzerland
| | - Thomas Verissimo
- Department of Medicine and Cell physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - David Legouis
- Department of Medicine and Cell physiology and Metabolism, University of Geneva, Geneva, Switzerland
- Division of Intensive Care, Department of Acute Medicine, Geneva University Hospitals, Geneva, Switzerland
| | - Grégoire Arnoux
- Department of Medicine and Cell physiology and Metabolism, University of Geneva, Geneva, Switzerland
- Service of Clinical Pathology, Department of Pathology and Immunology, University Hospitals and University of Geneva, Geneva, Switzerland
| | - Carolyn Heckenmeyer
- Department of Medicine and Cell physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Marylise Fernandez
- Department of Medicine and Cell physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Matthieu Tihy
- Service of Clinical Pathology, Department of Pathology and Immunology, University Hospitals and University of Geneva, Geneva, Switzerland
| | - Renuga D Rajaram
- Department of Medicine and Cell physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Vasiliki Delitsikou
- Department of Medicine and Cell physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Ngoc An Le
- Department of Chemistry, University of Zurich, Zurich, Switzerland
| | | | - Bert Mueller
- Biomaterials Science Center, Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland
| | - Georg Shulz
- Biomaterials Science Center, Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland
- Micro- and Nanotomography Core Facility, Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland
| | - Maja Lindenmeyer
- III Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Clemens Cohen
- Nephrological Center, Medical Clinic and Polyclinic IV, University of Munich, Munich, Germany
| | - Joseph M Rutkowski
- Department of Medical Physiology, Texas A&M University Health Science Center, Bryan, TX, USA
| | - Solange Moll
- Service of Clinical Pathology, Department of Pathology and Immunology, University Hospitals and University of Geneva, Geneva, Switzerland
| | - Carsten C Scholz
- Institute of Physiology, University of Zurich, Zurich, Switzerland
- National Centre of Competence in Research, Kidney. CH, University of Zurich, Zurich, Switzerland
- Institute of Physiology, University Medicine Greifswald, Greifswald, Germany
| | - Vartan Kurtcuoglu
- Institute of Physiology, University of Zurich, Zurich, Switzerland
- National Centre of Competence in Research, Kidney. CH, University of Zurich, Zurich, Switzerland
| | - Sophie de Seigneux
- Department of Medicine and Cell physiology and Metabolism, University of Geneva, Geneva, Switzerland
- Service of Nephrology, Department of Medicine, Geneva University Hospitals, Geneva, Switzerland
- National Centre of Competence in Research, Kidney. CH, University of Zurich, Zurich, Switzerland
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Kuo W, Rossinelli D, Schulz G, Wenger RH, Hieber S, Müller B, Kurtcuoglu V. Terabyte-scale supervised 3D training and benchmarking dataset of the mouse kidney. Sci Data 2023; 10:510. [PMID: 37537174 PMCID: PMC10400611 DOI: 10.1038/s41597-023-02407-5] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 07/24/2023] [Indexed: 08/05/2023] Open
Abstract
The performance of machine learning algorithms, when used for segmenting 3D biomedical images, does not reach the level expected based on results achieved with 2D photos. This may be explained by the comparative lack of high-volume, high-quality training datasets, which require state-of-the-art imaging facilities, domain experts for annotation and large computational and personal resources. The HR-Kidney dataset presented in this work bridges this gap by providing 1.7 TB of artefact-corrected synchrotron radiation-based X-ray phase-contrast microtomography images of whole mouse kidneys and validated segmentations of 33 729 glomeruli, which corresponds to a one to two orders of magnitude increase over currently available biomedical datasets. The image sets also contain the underlying raw data, threshold- and morphology-based semi-automatic segmentations of renal vasculature and uriniferous tubules, as well as true 3D manual annotations. We therewith provide a broad basis for the scientific community to build upon and expand in the fields of image processing, data augmentation and machine learning, in particular unsupervised and semi-supervised learning investigations, as well as transfer learning and generative adversarial networks.
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Affiliation(s)
- Willy Kuo
- Institute of Physiology, University of Zurich, Zurich, Switzerland
- National Centre of Competence in Research, Kidney.CH, Zurich, Switzerland
| | - Diego Rossinelli
- Institute of Physiology, University of Zurich, Zurich, Switzerland
- National Centre of Competence in Research, Kidney.CH, Zurich, Switzerland
| | - Georg Schulz
- Biomaterials Science Center, Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland
| | - Roland H Wenger
- Institute of Physiology, University of Zurich, Zurich, Switzerland
- National Centre of Competence in Research, Kidney.CH, Zurich, Switzerland
| | - Simone Hieber
- Biomaterials Science Center, Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland
| | - Bert Müller
- Biomaterials Science Center, Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland
| | - Vartan Kurtcuoglu
- Institute of Physiology, University of Zurich, Zurich, Switzerland.
- National Centre of Competence in Research, Kidney.CH, Zurich, Switzerland.
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Bächinger D, Filidoro N, Naville M, Juchler N, Kurtcuoglu V, Nadol JB, Schuknecht B, Kleinjung T, Veraguth D, Eckhard AH. Radiological feature heterogeneity supports etiological diversity among patient groups in Meniere's disease. Sci Rep 2023; 13:10303. [PMID: 37365255 DOI: 10.1038/s41598-023-36479-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Accepted: 06/04/2023] [Indexed: 06/28/2023] Open
Abstract
We aimed to determine the prevalence of radiological temporal bone features that in previous studies showed only a weak or an inconsistent association with the clinical diagnosis of Meniere's disease (MD), in two groups of MD patients (n = 71) with previously established distinct endolymphatic sac pathologies; i.e. the group MD-dg (ES degeneration) and the group MD-hp (ES hypoplasia). Delayed gadolinium-enhanced MRI and high-resolution CT data were used to determine and compare between and within (affected vs. non-affected side) groups geometric temporal bone features (lengths, widths, contours), air cell tract volume, height of the jugular bulb, sigmoid sinus width, and MRI signal intensity alterations of the ES. Temporal bone features with significant intergroup differences were the retrolabyrinthine bone thickness (1.04 ± 0.69 mm, MD-hp; 3.1 ± 1.9 mm, MD-dg; p < 0.0001); posterior contour tortuosity (mean arch-to-chord ratio 1.019 ± 0.013, MD-hp; 1.096 ± 0.038, MD-dg; p < 0.0001); and the pneumatized volume (1.37 [0.86] cm3, MD-hp; 5.25 [3.45] cm3, MD-dg; p = 0.03). Features with differences between the affected and non-affected sides within the MD-dg group were the sigmoid sinus width (6.5 ± 1.7 mm, affected; 7.6 ± 2.1 mm, non-affected; p = 0.04) and the MRI signal intensity of the endolymphatic sac (median signal intensity, affected vs. unaffected side, 0.59 [IQR 0.31-0.89]). Radiological temporal bone features known to be only weakly or inconsistently associated with the clinical diagnosis MD, are highly prevalent in either of two MD patient groups. These results support the existence of diverse-developmental and degenerative-disease etiologies manifesting with distinct radiological temporal bone abnormalities.
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Affiliation(s)
- David Bächinger
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Zurich, Zurich, Switzerland
- University of Zurich, Zurich, Switzerland
| | | | | | - Norman Juchler
- Institute of Applied Simulation, ZHAW University of Applied Sciences, Wädenswil, Switzerland
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Joseph B Nadol
- Otopathology Laboratory, Massachusetts Eye and Ear, 243 Charles Street, Boston, MA, 02114, USA
- Department of Otolaryngology - Head & Neck Surgery, Harvard Medical School, Boston, MA, USA
| | | | - Tobias Kleinjung
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Zurich, Zurich, Switzerland
- University of Zurich, Zurich, Switzerland
| | - Dorothe Veraguth
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Zurich, Zurich, Switzerland
- University of Zurich, Zurich, Switzerland
| | - Andreas H Eckhard
- Otopathology Laboratory, Massachusetts Eye and Ear, 243 Charles Street, Boston, MA, 02114, USA.
- Department of Otolaryngology - Head & Neck Surgery, Harvard Medical School, Boston, MA, USA.
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Dubs L, Charitatos V, Buoso S, Wegener S, Winklhofer S, Alkadhi H, Kurtcuoglu V. Assessment of extracranial carotid artery disease using digital twins - A pilot study. Neuroimage Clin 2023; 38:103435. [PMID: 37245493 PMCID: PMC10238877 DOI: 10.1016/j.nicl.2023.103435] [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: 01/19/2023] [Revised: 05/05/2023] [Accepted: 05/12/2023] [Indexed: 05/30/2023]
Abstract
To improve risk stratification in extracranial internal carotid artery disease (CAD), patients who would benefit maximally from revascularization must be identified. In cardiology, the fractional flow reserve (FFR) has become a reference standard for evaluating the functional severity of coronary artery stenosis, and noninvasive surrogates thereof relying on computational fluid dynamics (CFD) have been developed. Here, we present a CFD-based workflow using digital twins of patients' carotid bifurcations derived from computed tomography angiography for the noninvasive functional assessment of CAD. We reconstructed patient-specific digital twins of 37 carotid bifurcations. We implemented a CFD model using common carotid artery peak systolic velocity (PSV) acquired with Doppler ultrasound (DUS) as inlet boundary condition and a two-element Windkessel model as oulet boundary condition. The agreement between CFD and DUS on the PSV in the internal carotid artery (ICA) was then compared. The relative error for the agreement between DUS and CFD was 9% ± 20% and the intraclass correlation coefficient was 0.88. Furthermore, hyperemic simulations in a physiological range were feasible and unmasked markedly different pressure drops along two ICA stenoses with similar degree of narrowing under comparable ICA blood flow. Hereby, we lay the foundation for prospective studies on noninvasive CFD-based derivation of metrics similar to the FFR for the assessment of CAD.
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Affiliation(s)
- Linus Dubs
- University of Zurich, Institute of Physiology, The Interface Group, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
| | - Vasileios Charitatos
- University of Zurich, Institute of Physiology, The Interface Group, Winterthurerstrasse 190, 8057 Zürich, Switzerland; University Hospital Zurich, University of Zurich, Institute of Diagnostic and Interventional Radiology, Rämistrasse 100, 8091 Zürich, Switzerland.
| | - Stefano Buoso
- University of Zurich, Institute of Physiology, The Interface Group, Winterthurerstrasse 190, 8057 Zürich, Switzerland; ETH Zurich, Institute for Biomedical Engineering, Gloriastrasse 35, 8092 Zürich, Switzerland.
| | - Susanne Wegener
- University Hospital Zurich, University of Zurich, Clinical Neuroscience Center, Department of Neurology, Frauenklinikstrasse 10, 8091 Zürich, Switzerland.
| | - Sebastian Winklhofer
- University Hospital Zurich, University of Zurich, Clinical Neuroscience Center, Department of Neuroradiology, Frauenklinikstrasse 10, 8091 Zürich, Switzerland.
| | - Hatem Alkadhi
- University Hospital Zurich, University of Zurich, Institute of Diagnostic and Interventional Radiology, Rämistrasse 100, 8091 Zürich, Switzerland.
| | - Vartan Kurtcuoglu
- University of Zurich, Institute of Physiology, The Interface Group, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
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Kheram N, Boraschi A, Pfender N, Spiegelberg A, Kurtcuoglu V, Curt A, Schubert M, Zipser CM. Queckenstedt's test repurposed for the quantitative assessment of the cerebrospinal fluid pulsatility curve. Acta Neurochir (Wien) 2023; 165:1533-1543. [PMID: 37079108 DOI: 10.1007/s00701-023-05583-w] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 03/16/2023] [Indexed: 04/21/2023]
Abstract
PURPOSE Before the era of spinal imaging, presence of a spinal canal block was tested through gross changes in cerebrospinal fluid pressure (CSFP) provoked by manual compression of the jugular veins (referred to as Queckenstedt's test; QT). Beyond these provoked gross changes, cardiac-driven CSFP peak-to-valley amplitudes (CSFPp) can be recorded during CSFP registration. This is the first study to assess whether the QT can be repurposed to derive descriptors of the CSF pulsatility curve, focusing on feasibility and repeatability. METHOD Lumbar puncture was performed in lateral recumbent position in fourteen elderly patients (59.7±9.3 years, 6F) (NCT02170155) without stenosis of the spinal canal. CSFP was recorded during resting state and QT. A surrogate for the relative pulse pressure coefficient was computed from repeated QTs (i.e., RPPC-Q). RESULTS Resting state mean CSFP was 12.3 mmHg (IQR 3.2) and CSFPp was 1.0 mmHg (0.5). Mean CSFP rise during QT was 12.5 mmHg (7.3). CSFPp showed an average 3-fold increase at peak QT compared to the resting state. Median RPPC-Q was 0.18 (0.04). There was no systematic error in the computed metrics between the first and second QT. CONCLUSION This technical note describes a method to reliably derive, beyond gross CSFP increments, metrics related to cardiac-driven amplitudes during QT (i.e., RPPC-Q). A study comparing these metrics as obtained by established procedures (i.e., infusion testing) and by QT is warranted.
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Affiliation(s)
- Najmeh Kheram
- Department of Neurology and Neurophysiology, Balgrist University Hospital, Zurich, Switzerland
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Andrea Boraschi
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Nikolai Pfender
- Department of Neurology and Neurophysiology, Balgrist University Hospital, Zurich, Switzerland
| | - Andreas Spiegelberg
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Armin Curt
- Department of Neurology and Neurophysiology, Balgrist University Hospital, Zurich, Switzerland
| | - Martin Schubert
- Department of Neurology and Neurophysiology, Balgrist University Hospital, Zurich, Switzerland
| | - Carl Moritz Zipser
- Department of Neurology and Neurophysiology, Balgrist University Hospital, Zurich, Switzerland.
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10
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Boraschi A, Spiegelberg A, Karimi F, Capstick M, Fallahi A, Neufeld E, Kuster N, Kurtcuoglu V. Noninvasive measurement of head dielectric properties as a novel method for monitoring intracranial volume variations. Journal of Affective Disorders Reports 2023. [DOI: 10.1016/j.jadr.2023.100551] [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: 04/03/2023] Open
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11
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Rossinelli D, Killer HE, Meyer P, Knott G, Fourestey G, Kurtcuoglu V, Kohler C, Gruber P, Remonda L, Neutzner A, Berberat J. Large-scale morphometry of the subarachnoid space of the optic nerve. Fluids Barriers CNS 2023; 20:21. [PMID: 36944985 PMCID: PMC10029327 DOI: 10.1186/s12987-023-00423-6] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 03/10/2023] [Indexed: 03/23/2023] Open
Abstract
BACKGROUND The meninges, formed by dura, arachnoid and pia mater, cover the central nervous system and provide important barrier functions. Located between arachnoid and pia mater, the cerebrospinal fluid (CSF)-filled subarachnoid space (SAS) features a variety of trabeculae, septae and pillars. Like the arachnoid and the pia mater, these structures are covered with leptomeningeal or meningothelial cells (MECs) that form a barrier between CSF and the parenchyma of the optic nerve (ON). MECs contribute to the CSF proteome through extensive protein secretion. In vitro, they were shown to phagocytose potentially toxic proteins, such as α-synuclein and amyloid beta, as well as apoptotic cell bodies. They therefore may contribute to CSF homeostasis in the SAS as a functional exchange surface. Determining the total area of the SAS covered by these cells that are in direct contact with CSF is thus important for estimating their potential contribution to CSF homeostasis. METHODS Using synchrotron radiation-based micro-computed tomography (SRµCT), two 0.75 mm-thick sections of a human optic nerve were acquired at a resolution of 0.325 µm/pixel, producing images of multiple terabytes capturing the geometrical details of the CSF space. Special-purpose supercomputing techniques were employed to obtain a pixel-accurate morphometric description of the trabeculae and estimate internal volume and surface area of the ON SAS. RESULTS In the bulbar segment, the ON SAS microstructure is shown to amplify the MECs surface area up to 4.85-fold compared to an "empty" ON SAS, while just occupying 35% of the volume. In the intraorbital segment, the microstructure occupies 35% of the volume and amplifies the ON SAS area 3.24-fold. CONCLUSIONS We provided for the first time an estimation of the interface area between CSF and MECs. This area is of importance for estimating a potential contribution of MECs on CSF homeostasis.
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Affiliation(s)
- Diego Rossinelli
- Institute of Neuroradiology, Kantonsspital Aarau, Tellstrasse 25, CH-5001, Aarau, Switzerland.
- Institute of Physiology, University of Zurich, Zurich, Switzerland.
| | | | - Peter Meyer
- Ocular Pharmacology and Physiology, University Hospital of Basel, Basel, Switzerland
| | - Graham Knott
- Biological Electron Microscopy Facility (BioEM), Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
| | - Gilles Fourestey
- Scientific IT & Application Support (SCITAS), Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
| | | | - Corina Kohler
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Philipp Gruber
- Institute of Neuroradiology, Kantonsspital Aarau, Tellstrasse 25, CH-5001, Aarau, Switzerland
| | - Luca Remonda
- Institute of Neuroradiology, Kantonsspital Aarau, Tellstrasse 25, CH-5001, Aarau, Switzerland
- Medical Faculty, University of Bern, Bern, Switzerland
| | - Albert Neutzner
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Jatta Berberat
- Institute of Neuroradiology, Kantonsspital Aarau, Tellstrasse 25, CH-5001, Aarau, Switzerland
- Geriatric Psychiatry, Department of Psychiatry, University Hospitals of Geneva, University of Geneva, Geneva, Switzerland
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12
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Kheram N, Boraschi A, Pfender N, Friedl S, Rasenack M, Fritz B, Kurtcuoglu V, Schubert M, Curt A, Zipser CM. Cerebrospinal Fluid Pressure Dynamics as a Bedside Test in Traumatic Spinal Cord Injury to Assess Surgical Spinal Cord Decompression: Safety, Feasibility, and Proof-of-Concept. Neurorehabil Neural Repair 2023; 37:171-182. [PMID: 36919616 PMCID: PMC10152574 DOI: 10.1177/15459683231159662] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
BACKGROUND Sufficient and timely spinal cord decompression is a critical surgical objective for neurological recovery in spinal cord injury (SCI). Residual cord compression may be associated with disturbed cerebrospinal fluid pressure (CSFP) dynamics. OBJECTIVES This study aims to assess whether intrathecal CSFP dynamics in SCI following surgical decompression are feasible and safe, and to explore the diagnostic utility. METHODS Prospective cohort study. Bedside lumbar CSFP dynamics and cervical MRI were obtained following surgical decompression in N = 9 with mostly cervical acute-subacute SCI and N = 2 patients with non-traumatic SCI. CSFP measurements included mean CSFP, cardiac-driven CSFP peak-to-valley amplitudes (CSFPp), Valsalva maneuver, and Queckenstedt's test (firm pressure on jugular veins, QT). From QT, proxies for cerebrospinal fluid pulsatility curve were calculated (ie, relative pulse pressure coefficient; RPPC-Q). CSFP metrics were compared to spine-healthy patients. computer tomography (CT)-myelography was done in 3/8 simultaneous to CSFP measurements. RESULTS Mean age was 45 ± 9 years (range 17-67; 3F), SCI was complete (AIS A, N = 5) or incomplete (AIS B-D, N = 6). No adverse events related to CSFP assessments. CSFP rise during QT was induced in all patients [range 9.6-26.6 mmHg]. However, CSFPp was reduced in 3/11 (0.1-0.3 mmHg), and in 3/11 RPPC-Q was abnormal (0.01-0.05). Valsalva response was reduced in 8/11 (2.6-23.4 mmHg). CSFP dynamics corresponded to CT-myelography. CONCLUSIONS Comprehensive bedside lumbar CSFP dynamics in SCI following decompression are safe, feasible, and can reveal distinct patterns of residual spinal cord compression. Longitudinal studies are required to define critical thresholds of impaired CSFP dynamics that may impact neurological recovery and requiring surgical revisions.
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Affiliation(s)
- Najmeh Kheram
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland.,Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Andrea Boraschi
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Nikolai Pfender
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Susanne Friedl
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Maria Rasenack
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Benjamin Fritz
- Department of Radiology, Balgrist University Hospital, Zurich, Switzerland
| | | | - Martin Schubert
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Armin Curt
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Carl M Zipser
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
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Boraschi A, Spiegelberg A, Karimi F, Graf K, Fallahi A, Neufeld E, Kuster N, Kurtcuoglu V. The effect of body position change on noninvasively acquired intracranial pulse waves. Physiol Meas 2023; 44. [PMID: 36913731 DOI: 10.1088/1361-6579/acc3d6] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 03/13/2023] [Indexed: 03/15/2023]
Abstract
Objective. Craniospinal compliance (CC) is an important metric for the characterization of space-occupying neurological pathologies. CC is obtained using invasive procedures that carry risks for the patients. Therefore, noninvasive methods for acquiring surrogates of CC have been proposed, most recently based on changes in the head's dielectric properties during the cardiac cycle. Here, we have tested whether changes in body position, which are known to influence CC, are reflected in a capacitively acquired signal (hereinafter referred to as W) originating from dynamic changes of the head's dielectric properties. 
Approach. Eighteen young healthy volunteers were included in the study. After 10 minutes in supine position, subjects were tilted head-up (HUT), back to 0° (horizontal, control), and then head-down (HDT). Metrics related to cardiovascular action were extracted from W, including AMP, the peak-to-valley amplitude of the cardiac modulation of W. Computational electromagnetic simulations were performed to probe the association between intracranial volume change and W. 
Main results. AMP decreased during HUT (0°: 2869±597 arbitrary units (au); +75°: 2307±490 au, P=0.002) and increased during HDT (-30°: 4403±1428 au, P<0.0001). The same behavior was predicted by the electromagnetic model. 
Significance. Tilting affects the distribution of CC between cranial and spinal compartments. Cardiovascular action induces compliance-dependent oscillatory changes in the intracranial fluid composition, which causes corresponding variations in the head's dielectric properties. These manifest as increasing AMP with decreasing intracranial compliance, which suggests that W may contain information related to CC, and that it might be possible to derive CC surrogates therefrom.
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Affiliation(s)
- Andrea Boraschi
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, Zurich, ZH, 8057, SWITZERLAND
| | - Andreas Spiegelberg
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, Zurich, ZH, 8057, SWITZERLAND
| | - Fariba Karimi
- Foundation for Research on Information Technologies in Society (IT'IS), Zeughausstrasse 43, Zurich, ZH, 8004, SWITZERLAND
| | - Kevin Graf
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, Zurich, ZH, 8057, SWITZERLAND
| | - Arya Fallahi
- Foundation for Research on Information Technologies in Society (IT'IS), Zeughausstrasse 43, Zurich, ZH, 8004, SWITZERLAND
| | - Esra Neufeld
- Foundation for Research on Information Technologies in Society (IT'IS), Zeughausstrasse 43, Zurich, ZH, 8004, SWITZERLAND
| | - Niels Kuster
- Foundation for Research on Information Technologies in Society (IT'IS), Zeughausstrasse 43, Zurich, ZH, 8004, SWITZERLAND
| | - Vartan Kurtcuoglu
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, Zurich, ZH, 8057, SWITZERLAND
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14
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Razzaghi Khamesi P, Charitatos V, Heerfordt EK, MacAulay N, Kurtcuoglu V. Are standing osmotic gradients the main driver of cerebrospinal fluid production? A computational analysis. Fluids Barriers CNS 2023; 20:18. [PMID: 36915140 PMCID: PMC10012606 DOI: 10.1186/s12987-023-00419-2] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 02/26/2023] [Indexed: 03/14/2023] Open
Abstract
BACKGROUND The mechanisms of cerebrospinal fluid (CSF) production by the ventricular choroid plexus (ChP) have not been fully deciphered. One prominent hypothesized mechanism is trans-epithelial water transport mediated by accumulation of solutes at the luminal ChP membrane that produces local osmotic gradients. However, this standing osmotic gradient hypothesis has not been systematically tested. METHODS To assess the plausibility of the standing gradient mechanism serving as the main driver of CSF production by the ChP, we developed a three-dimensional (3D) and a one-dimensional (1D) computational model to quantitatively describe the associated processes in the rat ChP inter-microvillar spaces and in CSF pools between macroscopic ChP folds (1D only). The computationally expensive 3D model was used to examine the applicability of the 1D model for hypothesis testing. The 1D model was employed to predict the rate of CSF produced by the standing gradient mechanism for 200,000 parameter permutations. Model parameter values for each permutation were chosen by random sampling from distributions derived from published experimental data. RESULTS Both models predict that the CSF production rate by the standing osmotic gradient mechanism is below 10% of experimentally measured values that reflect the contribution of all actual production mechanisms. The 1D model indicates that increasing the size of CSF pools between ChP folds, where diffusion dominates solute transport, would increase the contribution of the standing gradient mechanism to CSF production. CONCLUSIONS The models suggest that the effect of standing osmotic gradients is too small to contribute substantially to CSF production. ChP motion and movement of CSF in the ventricles, which are not accounted for in the models, would further reduce this effect, making it unlikely that standing osmotic gradients are the main drivers of CSF production.
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Affiliation(s)
- Pooya Razzaghi Khamesi
- The Interface Group, Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Vasileios Charitatos
- The Interface Group, Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Eva K Heerfordt
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | - Nanna MacAulay
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland. .,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland. .,Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland.
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15
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Bessen MA, Gayen CD, Quarrington RD, Walls AC, Leonard AV, Kurtcuoglu V, Jones CF. Characterising spinal cerebrospinal fluid flow in the pig with phase-contrast magnetic resonance imaging. Fluids Barriers CNS 2023; 20:5. [PMID: 36653870 PMCID: PMC9850564 DOI: 10.1186/s12987-022-00401-4] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 12/13/2022] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Detecting changes in pulsatile cerebrospinal fluid (CSF) flow may assist clinical management decisions, but spinal CSF flow is relatively understudied. Traumatic spinal cord injuries (SCI) often cause spinal cord swelling and subarachnoid space (SAS) obstruction, potentially causing pulsatile CSF flow changes. Pigs are emerging as a favoured large animal SCI model; therefore, the aim of this study was to characterise CSF flow along the healthy pig spine. METHODS Phase-contrast magnetic resonance images (PC-MRI), retrospectively cardiac gated, were acquired for fourteen laterally recumbent, anaesthetised and ventilated, female domestic pigs (22-29 kg). Axial images were obtained at C2/C3, T8/T9, T11/T12 and L1/L2. Dorsal and ventral SAS regions of interest (ROI) were manually segmented. CSF flow and velocity were determined throughout a cardiac cycle. Linear mixed-effects models, with post-hoc comparisons, were used to identify differences in peak systolic/diastolic flow, and maximum velocity (cranial/caudal), across spinal levels and dorsal/ventral SAS. Velocity wave speed from C2/C3 to L1/L2 was calculated. RESULTS PC-MRI data were obtained for 11/14 animals. Pulsatile CSF flow was observed at all spinal levels. Peak systolic flow was greater at C2/C3 (dorsal: - 0.32 ± 0.14 mL/s, ventral: - 0.15 ± 0.13 mL/s) than T8/T9 dorsally (- 0.04 ± 0.03 mL/s; p < 0.001), but not different ventrally (- 0.08 ± 0.08 mL/s; p = 0.275), and no difference between thoracolumbar levels (p > 0.05). Peak diastolic flow was greater at C2/C3 (0.29 ± 0.08 mL/s) compared to T8/T9 (0.03 ± 0.03 mL/s, p < 0.001) dorsally, but not different ventrally (p = 1.000). Cranial and caudal maximum velocity at C2/C3 were greater than thoracolumbar levels dorsally (p < 0.001), and T8/T9 and L1/L2 ventrally (p = 0.022). Diastolic velocity wave speed was 1.41 ± 0.39 m/s dorsally and 1.22 ± 0.21 m/s ventrally, and systolic velocity wave speed was 1.02 ± 0.25 m/s dorsally and 0.91 ± 0.22 m/s ventrally. CONCLUSIONS In anaesthetised and ventilated domestic pigs, spinal CSF has lower pulsatile flow and slower velocity wave propagation, compared to humans. This study provides baseline CSF flow at spinal levels relevant for future SCI research in this animal model.
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Affiliation(s)
- Madeleine Amy Bessen
- grid.1010.00000 0004 1936 7304Adelaide Spinal Research Group and Centre for Orthopaedics and Trauma Research, Adelaide Medical School, The University of Adelaide, Level 7, Adelaide Health and Medical Sciences Building, The University of Adelaide, North Terrace, Adelaide, SA 5005 Australia
| | - Christine Diana Gayen
- grid.1010.00000 0004 1936 7304Adelaide Spinal Research Group and Centre for Orthopaedics and Trauma Research, Adelaide Medical School, The University of Adelaide, Level 7, Adelaide Health and Medical Sciences Building, The University of Adelaide, North Terrace, Adelaide, SA 5005 Australia ,grid.1010.00000 0004 1936 7304Translational Neuropathology Laboratory, School of Biomedicine, The University of Adelaide, Level 2, Helen Mayo North Building, The University of Adelaide, Frome Road, Adelaide, SA 5005 Australia
| | - Ryan David Quarrington
- grid.1010.00000 0004 1936 7304Adelaide Spinal Research Group and Centre for Orthopaedics and Trauma Research, Adelaide Medical School, The University of Adelaide, Level 7, Adelaide Health and Medical Sciences Building, The University of Adelaide, North Terrace, Adelaide, SA 5005 Australia ,grid.1010.00000 0004 1936 7304School of Electrical and Mechanical Engineering, The University of Adelaide, North Terrace, Adelaide, SA 5005 Australia
| | - Angela Catherine Walls
- grid.430453.50000 0004 0565 2606Clinical and Research Imaging Centre, South Australian Health and Medical Research Institute, National Imaging Facility, Northern Pod, SAHMRI, North Terrace, Adelaide, SA 5000 Australia
| | - Anna Victoria Leonard
- grid.1010.00000 0004 1936 7304Translational Neuropathology Laboratory, School of Biomedicine, The University of Adelaide, Level 2, Helen Mayo North Building, The University of Adelaide, Frome Road, Adelaide, SA 5005 Australia
| | - Vartan Kurtcuoglu
- grid.7400.30000 0004 1937 0650Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland ,grid.7400.30000 0004 1937 0650Zurich Center for Integrative Human Physiology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland ,grid.7400.30000 0004 1937 0650Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Claire Frances Jones
- grid.1010.00000 0004 1936 7304Adelaide Spinal Research Group and Centre for Orthopaedics and Trauma Research, Adelaide Medical School, The University of Adelaide, Level 7, Adelaide Health and Medical Sciences Building, The University of Adelaide, North Terrace, Adelaide, SA 5005 Australia ,grid.1010.00000 0004 1936 7304School of Electrical and Mechanical Engineering, The University of Adelaide, North Terrace, Adelaide, SA 5005 Australia ,grid.416075.10000 0004 0367 1221Department of Orthopaedics, Royal Adelaide Hospital, Adelaide, SA 5000 Australia
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16
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Karimi F, Neufeld E, Fallahi A, Boraschi A, Zwanenburg JJM, Spiegelberg A, Kurtcuoglu V, Kuster N. Theory for a non-invasive diagnostic biomarker for craniospinal diseases. Neuroimage Clin 2023; 37:103280. [PMID: 36508887 PMCID: PMC9763738 DOI: 10.1016/j.nicl.2022.103280] [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: 10/07/2022] [Revised: 12/01/2022] [Accepted: 12/02/2022] [Indexed: 12/13/2022]
Abstract
Monitoring intracranial pressure (ICP) and craniospinal compliance (CC) is frequently required in the treatment of patients suffering from craniospinal diseases. However, current approaches are invasive and cannot provide continuous monitoring of CC. Dynamic exchange of blood and cerebrospinal fluid (CSF) between cranial and spinal compartments due to cardiac action transiently modulates the geometry and dielectric properties of the brain. The resulting impedance changes can be measured and might be usable as a non-invasive CC surrogate. A numerically robust and computationally efficient approach based on the reciprocity theorem was developed to compute dynamic impedance changes resulting from small geometry and material property changes. The approach was successfully verified against semi-analytical benchmarks, before being combined with experimental brain pulsation data to study the information content of the impedance variation. The results indicate that the measurable signal is dominated by the pulsatile displacement of the cortical brain surface, with minor contributions from the ventricular surfaces and from changes in brain perfusion. Different electrode setups result in complementary information. The information content from the investigated three electrode pairs was employed to successfully infer subject-specific brain pulsation and motion features. This suggests that non-invasive CC surrogates based on impedance monitoring could be established.
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Affiliation(s)
- Fariba Karimi
- Foundation for Research on Information Technologies in Society (IT'IS), Zurich, Switzerland; Department of Information Technology and Electrical Engineering, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland.
| | - Esra Neufeld
- Foundation for Research on Information Technologies in Society (IT'IS), Zurich, Switzerland
| | - Arya Fallahi
- Foundation for Research on Information Technologies in Society (IT'IS), Zurich, Switzerland; Department of Information Technology and Electrical Engineering, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
| | - Andrea Boraschi
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Jaco J M Zwanenburg
- Center for Image Sciences, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Andreas Spiegelberg
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Niels Kuster
- Foundation for Research on Information Technologies in Society (IT'IS), Zurich, Switzerland; Department of Information Technology and Electrical Engineering, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
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17
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Oernbo EK, Steffensen AB, Razzaghi Khamesi P, Toft-Bertelsen TL, Barbuskaite D, Vilhardt F, Gerkau NJ, Tritsaris K, Simonsen AH, Lolansen SD, Andreassen SN, Hasselbalch SG, Zeuthen T, Rose CR, Kurtcuoglu V, MacAulay N. Membrane transporters control cerebrospinal fluid formation independently of conventional osmosis to modulate intracranial pressure. Fluids Barriers CNS 2022; 19:65. [PMID: 36038945 PMCID: PMC9422132 DOI: 10.1186/s12987-022-00358-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [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: 03/02/2022] [Accepted: 07/13/2022] [Indexed: 11/23/2022] Open
Abstract
Background Disturbances in the brain fluid balance can lead to life-threatening elevation in the intracranial pressure (ICP), which represents a vast clinical challenge. Nevertheless, the details underlying the molecular mechanisms governing cerebrospinal fluid (CSF) secretion are largely unresolved, thus preventing targeted and efficient pharmaceutical therapy of cerebral pathologies involving elevated ICP. Methods Experimental rats were employed for in vivo determinations of CSF secretion rates, ICP, blood pressure and ex vivo excised choroid plexus for morphological analysis and quantification of expression and activity of various transport proteins. CSF and blood extractions from rats, pigs, and humans were employed for osmolality determinations and a mathematical model employed to determine a contribution from potential local gradients at the surface of choroid plexus. Results We demonstrate that CSF secretion can occur independently of conventional osmosis and that local osmotic gradients do not suffice to support CSF secretion. Instead, the CSF secretion across the luminal membrane of choroid plexus relies approximately equally on the Na+/K+/2Cl− cotransporter NKCC1, the Na+/HCO3− cotransporter NBCe2, and the Na+/K+-ATPase, but not on the Na+/H+ exchanger NHE1. We demonstrate that pharmacological modulation of CSF secretion directly affects the ICP. Conclusions CSF secretion appears to not rely on conventional osmosis, but rather occur by a concerted effort of different choroidal transporters, possibly via a molecular mode of water transport inherent in the proteins themselves. Therapeutic modulation of the rate of CSF secretion may be employed as a strategy to modulate ICP. These insights identify new promising therapeutic targets against brain pathologies associated with elevated ICP. Supplementary Information The online version contains supplementary material available at 10.1186/s12987-022-00358-4.
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Affiliation(s)
- Eva K Oernbo
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Annette B Steffensen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Pooya Razzaghi Khamesi
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Trine L Toft-Bertelsen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Dagne Barbuskaite
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Frederik Vilhardt
- Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Niklas J Gerkau
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, 40225, Düsseldorf, Germany
| | - Katerina Tritsaris
- Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Anja H Simonsen
- Danish Dementia Research Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Sara D Lolansen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Søren N Andreassen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Steen G Hasselbalch
- Danish Dementia Research Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Zeuthen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark
| | - Christine R Rose
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, Universitätsstrasse 1, 40225, Düsseldorf, Germany
| | - Vartan Kurtcuoglu
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Nanna MacAulay
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark.
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18
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Kheram N, Pfender N, Boraschi A, Farshad M, Kurtcuoglu V, Curt A, Schubert M, Zipser CM. Cerebrospinal fluid pressure dynamics reveal signs of effective spinal canal narrowing in ambiguous spine conditions. Front Neurol 2022; 13:951018. [PMID: 36016547 PMCID: PMC9397118 DOI: 10.3389/fneur.2022.951018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 07/15/2022] [Indexed: 12/03/2022] Open
Abstract
Spinal canal narrowing with consecutive spinal cord compression is considered a key mechanism in degenerative cervical myelopathy (DCM). DCM is a common spine condition associated with progressive neurological disability, and timely decompressive surgery is recommended. However, the clinical and radiological diagnostic workup is often ambiguous, challenging confident proactive treatment recommendations. Cerebrospinal fluid pressure dynamics (CSFP) are altered by spinal canal narrowing. Therefore, we aim to explore the potential value of bedside CSFP assessments for qualitative and quantitative assessment of spinal canal narrowing in DCM. In this prospective case series, seven patients with DCM underwent bedside lumbar puncture with measurement of CSFP dynamics and routine CSF analysis (NCT02170155). The patients were enrolled when standard diagnostic algorithms did not permit a clear treatment decision. Measurements include baseline CSFP, cardiac-driven CSFP peak-to-trough amplitude (CSFPp), and the Queckenstedt's test (firm pressure on jugular veins) in neutral and reclined head position. From the Queckenstedt's test, proxies for craniospinal elastance (i.e., relative pulse pressure coefficient; RPPC-Q) were calculated analogously to infusion testing. CSFP metrics were deemed suspicious of canal narrowing when numbers were lower than the minimum value from a previously tested elderly spine-healthy cohort (N = 14). Mean age was 56 ± 13 years (range, 38–75; 2F); symptom severity was mostly mild to moderate (mean mJOA, 13.5 ± 2.6; range, 9–17). All the patients showed some extent of cervical stenosis in the MRI of unclear significance (5/7 following decompressive cervical spine surgery with an adjacent level or residual stenosis). Baseline CSFP was normal except for one patient (range, 4.7–17.4 mmHg). Normal values were found for CSFPp (0.4–1.3 mmHg) and the Queckenstedt's test in normal head positioning (9.-25.3 mmHg). During reclination, the Queckenstedt's test significantly decreased in one, and CSFPp in another case (>50% compared to normal position). RPPC-Q (0.07–0.19) aligned with lower values from spine-healthy (0.10–0.44). Routine CSF examinations showed mild total protein elevation (mean, 522 ± 108 mg/ml) without further evidence for the disturbed blood brain barrier. Intrathecal CSFP measurements allow discerning disturbed from normal CSFP dynamics in this population. Prospective longitudinal studies should further evaluate the diagnostic utility of CSFP assessments in DCM.
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Affiliation(s)
- Najmeh Kheram
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
- University Spine Center, Balgrist University Hospital, Zurich, Switzerland
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Nikolai Pfender
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
- University Spine Center, Balgrist University Hospital, Zurich, Switzerland
| | - Andrea Boraschi
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Mazda Farshad
- University Spine Center, Balgrist University Hospital, Zurich, Switzerland
| | | | - Armin Curt
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
- University Spine Center, Balgrist University Hospital, Zurich, Switzerland
| | - Martin Schubert
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
- University Spine Center, Balgrist University Hospital, Zurich, Switzerland
| | - Carl M. Zipser
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
- University Spine Center, Balgrist University Hospital, Zurich, Switzerland
- *Correspondence: Carl M. Zipser
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19
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Spiegelberg A, Boraschi A, Karimi F, Capstick M, Fallahi A, Neufeld E, Kuster N, Kurtcuoglu V. Noninvasive Monitoring of Intracranial Pulse Waves. IEEE Trans Biomed Eng 2022; 70:144-153. [PMID: 35763474 DOI: 10.1109/tbme.2022.3186748] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE The clinical management of several neurological disorders benefits from the assessment of intracranial pressure and craniospinal compliance. However, the associated procedures are invasive in nature. Here, we aimed to assess whether naturally occurring periodic changes in the dielectric properties of the head could serve as the basis for deriving surrogates of craniospinal compliance noninvasively. METHODS We designed a device and electrodes for noninvasive measurement of periodic changes of the dielectric properties of the human head. We characterized the properties of the device-electrode-head system by measurements on healthy volunteers, by computational modeling, and by electromechanical modeling. We then performed hyperventilation testing to assess whether the measured signal is of intracranial origin. RESULTS Signals obtained with the device on volunteers showed characteristic cardiac and respiratory modulations. Signal oscillations can be attributed primarily to changes in resistive properties of the head during cardiac and respiratory cycles. Reduction of end-tidal CO2, through hyperventilation, resulted in a decrease in the signal amplitude associated with cardiovascular action. CONCLUSION Given the higher CO2 reactivity of intracranial vessels compared to extracranial ones, the results of hyperventilation testing suggest that the acquired signal is, in part, of intracranial origin. SIGNIFICANCE If confirmed in larger cohorts, our observations suggest that noninvasive capacitive acquisition of changes in the dielectric properties of the head could be used to derive surrogates of craniospinal compliance.
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20
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Juchler N, Schilling S, Bijlenga P, Kurtcuoglu V, Hirsch S. Shape Trumps Size: Image-Based Morphological Analysis Reveals That the 3D Shape Discriminates Intracranial Aneurysm Disease Status Better Than Aneurysm Size. Front Neurol 2022; 13:809391. [PMID: 35592468 PMCID: PMC9110927 DOI: 10.3389/fneur.2022.809391] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 03/29/2022] [Indexed: 11/13/2022] Open
Abstract
Background To date, it remains difficult for clinicians to reliably assess the disease status of intracranial aneurysms. As an aneurysm's 3D shape is strongly dependent on the underlying formation processes, it is believed that the presence of certain shape features mirrors the disease status of the aneurysm wall. Currently, clinicians associate irregular shape with wall instability. However, no consensus exists about which shape features reliably predict instability. In this study, we present a benchmark to identify shape features providing the highest predictive power for aneurysm rupture status. Methods 3D models of aneurysms were extracted from medical imaging data (3D rotational angiographies) using a standardized protocol. For these aneurysm models, we calculated a set of metrics characterizing the 3D shape: Geometry indices (such as undulation, ellipticity and non-sphericity); writhe- and curvature-based metrics; as well as indices based on Zernike moments. Using statistical learning methods, we investigated the association between shape features and aneurysm disease status. This processing was applied to a clinical dataset of 750 aneurysms (261 ruptured, 474 unruptured) registered in the AneuX morphology database. We report here statistical performance metrics [including the area under curve (AUC)] for morphometric models to discriminate between ruptured and unruptured aneurysms. Results The non-sphericity index NSI (AUC = 0.80), normalized Zernike energies ZNsurf (AUC = 0.80) and the modified writhe-index W¯meanL1 (AUC = 0.78) exhibited the strongest association with rupture status. The combination of predictors further improved the predictive performance (without location: AUC = 0.82, with location AUC = 0.87). The anatomical location was a good predictor for rupture status on its own (AUC = 0.78). Different protocols to isolate the aneurysm dome did not affect the prediction performance. We identified problems regarding generalizability if trained models are applied to datasets with different selection biases. Conclusions Morphology provided a clear indication of the aneurysm disease status, with parameters measuring shape (especially irregularity) being better predictors than size. Quantitative measurement of shape, alone or in conjunction with information about aneurysm location, has the potential to improve the clinical assessment of intracranial aneurysms.
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Affiliation(s)
- Norman Juchler
- School of Life Sciences and Facility Management, Institute of Computational Life Sciences, Zurich University of Applied Sciences, Wädenswil, Switzerland
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
- *Correspondence: Norman Juchler
| | - Sabine Schilling
- School of Life Sciences and Facility Management, Institute of Computational Life Sciences, Zurich University of Applied Sciences, Wädenswil, Switzerland
- Lucerne School of Business, Institute of Tourism and Mobility, Lucerne University of Applied Sciences and Arts, Lucerne, Switzerland
| | - Philippe Bijlenga
- Neurosurgery Division, Department of Clinical Neurosciences, Geneva University Hospital and Faculty of Medicine, Geneva, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
- National Center of Competence in Research, Kidney.CH, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Sven Hirsch
- School of Life Sciences and Facility Management, Institute of Computational Life Sciences, Zurich University of Applied Sciences, Wädenswil, Switzerland
- Sven Hirsch
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21
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Abstract
Our kidneys receive about one-fifth of the cardiac output at rest and have a low oxygen extraction ratio, but may sustain, under some conditions, hypoxic injuries that might lead to chronic kidney disease. This is due to large regional variations in renal blood flow and oxygenation, which are the prerequisite for some and the consequence of other kidney functions. The concurrent operation of these functions is reliant on a multitude of neuro-hormonal signaling cascades and feedback loops that also include the regulation of renal blood flow and tissue oxygenation. Starting with open questions on regulatory processes and disease mechanisms, we review herein the literature on renal blood flow and oxygenation. We assess the current understanding of renal blood flow regulation, reasons for disparities in oxygen delivery and consumption, and the consequences of disbalance between O2 delivery, consumption, and removal. We further consider methods for measuring and computing blood velocity, flow rate, oxygen partial pressure, and related parameters and point out how limitations of these methods constitute important hurdles in this area of research. We conclude that to obtain an integrated understanding of the relation between renal function and renal blood flow and oxygenation, combined experimental and computational modeling studies will be needed.
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Affiliation(s)
- Aurelie Edwards
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA, 02215, USA
| | - Vartan Kurtcuoglu
- Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland. .,National Center of Competence in Research, Kidney.CH, University of Zurich, Zurich, Switzerland. .,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
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22
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Fang P, Du J, Boraschi A, Bozzi S, Redaelli A, Schmid Daners M, Kurtcuoglu V, Consolo F, de Zélicourt D. Insights Into the Low Rate of In-Pump Thrombosis With the HeartMate 3: Does the Artificial Pulse Improve Washout? Front Cardiovasc Med 2022; 9:775780. [PMID: 35360020 PMCID: PMC8962620 DOI: 10.3389/fcvm.2022.775780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 02/02/2022] [Indexed: 01/14/2023] Open
Abstract
While earlier studies reported no relevant effect of the HeartMate 3 (HM3) artificial pulse (AP) on bulk pump washout, its effect on regions with prolonged residence times remains unexplored. Using numerical simulations, we compared pump washout in the HM3 with and without AP with a focus on the clearance of the last 5% of the pump volume. Results were examined in terms of flush-volume (Vf, number of times the pump was flushed with new blood) to probe the effect of the AP independent of changing flow rate. Irrespective of the flow condition, the HM3 washout scaled linearly with flush volume up to 70% washout and slowed down for the last 30%. Flush volumes needed to washout 95% of the pump were comparable with and without the AP (1.3–1.4 Vf), while 99% washout required 2.1–2.2 Vf with the AP vs. 2.5 Vf without the AP. The AP enhanced washout of the bend relief and near-wall regions. It also transiently shifted or eliminated stagnation regions and led to rapid wall shear stress fluctuations below the rotor and in the secondary flow path. Our results suggest potential benefits of the AP for clearance of fluid regions that might elicit in-pump thrombosis and provide possible mechanistic rationale behind clinical data showing very low rate of in-pump thrombosis with the HM3. Further optimization of the AP sequence is warranted to balance washout efficacy while limiting blood damage.
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Affiliation(s)
- Peng Fang
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen, China
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Jianjun Du
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen, China
| | - Andrea Boraschi
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Silvia Bozzi
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Alberto Redaelli
- Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy
| | - Marianne Schmid Daners
- Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Filippo Consolo
- Anesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Milano, Italy
- Università Vita Salute San Raffaele, Milano, Italy
| | - Diane de Zélicourt
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
- *Correspondence: Diane de Zélicourt
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23
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Taslimifar M, Faltys M, Kurtcuoglu V, Verrey F, Makrides V. Analysis of L-leucine amino acid transporter species activity and gene expression by human blood brain barrier hCMEC/D3 model reveal potential LAT1, LAT4, B 0AT2 and y +LAT1 functional cooperation. J Cereb Blood Flow Metab 2022; 42:90-103. [PMID: 34427144 PMCID: PMC8721536 DOI: 10.1177/0271678x211039593] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In the CNS, amino acid (AA) neurotransmitters and neurotransmitter precursors are subject to tight homeostatic control mediated by blood-brain barrier (BBB) solute carrier amino acid transporters (AATs). Since the BBB is composed of multiple closely apposed cell types and opportunities for human in vivo studies are limited, we used in vitro and computational approaches to investigate human BBB AAT activity and regulation. Quantitative real-time PCR (qPCR) of the human BBB endothelial cell model hCMEC/D3 (D3) was used to determine expression of selected AAT, tight junction (TJ), and signal transduction (ST) genes under various culture conditions. L-leucine uptake data were interrogated with a computational model developed by our group for calculating AAT activity in complex cell cultures. This approach is potentially applicable to in vitro cell culture drug studies where multiple "receptors" may mediate observed responses. Of 7 Leu AAT genes expressed by D3 only the activity of SLC7A5-SLC3A2/LAT1-4F2HC (LAT1), SLC43A2/LAT4 (LAT4) and sodium-dependent AATs, SLC6A15/B0AT2 (B0AT2), and SLC7A7/y+LAT1 (y+LAT1) were calculated to be required for Leu uptake. Therefore, D3 Leu transport may be mediated by a potentially physiologically relevant functional cooperation between the known BBB AAT, LAT1 and obligatory exchange (y+LAT1), facilitative diffusion (LAT4), and sodium symporter (B0AT2) transporters.
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Affiliation(s)
- Mehdi Taslimifar
- The Interface Group, Institute of Physiology, University of Zürich, Zürich, Switzerland.,Epithelial Transport Group, Institute of Physiology, University of Zürich, Zürich, Switzerland
| | - Martin Faltys
- Epithelial Transport Group, Institute of Physiology, University of Zürich, Zürich, Switzerland.,Department of Intensive Care Medicine, University Hospital, University of Bern, Bern, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zürich, Zürich, Switzerland.,National Center of Competence in Research, Kidney CH, Switzerland
| | - François Verrey
- Epithelial Transport Group, Institute of Physiology, University of Zürich, Zürich, Switzerland.,National Center of Competence in Research, Kidney CH, Switzerland
| | - Victoria Makrides
- The Interface Group, Institute of Physiology, University of Zürich, Zürich, Switzerland.,Epithelial Transport Group, Institute of Physiology, University of Zürich, Zürich, Switzerland.,EIC BioMedical Labs, Norwood, MA, USA
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24
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Rodgers G, Tanner C, Schulz G, Migga A, Kuo W, Bikis C, Scheel M, Kurtcuoglu V, Weitkamp T, Müller B. Virtual histology of an entire mouse brain from formalin fixation to paraffin embedding. Part 2: Volumetric strain fields and local contrast changes. J Neurosci Methods 2022; 365:109385. [PMID: 34637810 DOI: 10.1016/j.jneumeth.2021.109385] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 07/15/2021] [Accepted: 10/07/2021] [Indexed: 01/14/2023]
Abstract
BACKGROUND Fixation and embedding of post mortem brain tissue is a pre-requisite for both gold-standard conventional histology and X-ray virtual histology. This process alters the morphology and density of the brain microanatomy. NEW METHOD To quantify these changes, we employed synchrotron radiation-based hard X-ray tomography with 3 μm voxel length to visualize the same mouse brain after fixation in 4% formalin, immersion in ethanol solutions (50%, 70%, 80%, 90%, and 100%), xylene, and finally after embedding in a paraffin block. The volumetric data were non-rigidly registered to the initial formalin-fixed state to align the microanatomy within the entire mouse brain. RESULTS Volumetric strain fields were used to characterize local shrinkage, which was found to depend on the anatomical region and distance to external surface. X-ray contrast was altered and enhanced by preparation-induced inter-tissue density changes. The preparation step can be selected to highlight specific anatomical features. For example, fiber tract contrast is amplified in 100% ethanol. COMPARISON WITH EXISTING METHODS Our method provides volumetric strain fields, unlike approaches based on feature-to-feature or volume measurements. Volumetric strain fields are produced by non-rigid registration, which is less labor-intensive and observer-dependent than volume change measurements based on manual segmentations. X-ray microtomography provides spatial resolution at least an order of magnitude higher than magnetic resonance microscopy, allowing for analysis of morphology and density changes within the brain's microanatomy. CONCLUSION Our approach belongs to three-dimensional virtual histology with isotropic micrometer spatial resolution and therefore complements atlases based on a combination of magnetic resonance microscopy and optical micrographs of serial histological sections.
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Affiliation(s)
- Griffin Rodgers
- Biomaterials Science Center, Department of Biomedical Engineering, University of Basel, 4123 Allschwil, Switzerland; Biomaterials Science Center, Department of Clinical Research, University Hospital Basel, 4031 Basel, Switzerland
| | - Christine Tanner
- Biomaterials Science Center, Department of Biomedical Engineering, University of Basel, 4123 Allschwil, Switzerland; Biomaterials Science Center, Department of Clinical Research, University Hospital Basel, 4031 Basel, Switzerland.
| | - Georg Schulz
- Biomaterials Science Center, Department of Biomedical Engineering, University of Basel, 4123 Allschwil, Switzerland; Biomaterials Science Center, Department of Clinical Research, University Hospital Basel, 4031 Basel, Switzerland
| | - Alexandra Migga
- Biomaterials Science Center, Department of Biomedical Engineering, University of Basel, 4123 Allschwil, Switzerland; Biomaterials Science Center, Department of Clinical Research, University Hospital Basel, 4031 Basel, Switzerland
| | - Willy Kuo
- The Interface Group, Institute of Physiology, University of Zurich, 8057 Zurich, Switzerland; National Centre of Competence in Research, Kidney.CH, 8057 Zurich, Switzerland
| | - Christos Bikis
- Biomaterials Science Center, Department of Biomedical Engineering, University of Basel, 4123 Allschwil, Switzerland; Biomaterials Science Center, Department of Clinical Research, University Hospital Basel, 4031 Basel, Switzerland; Integrierte Psychiatrie Winterthur - Zürcher Unterland, 8408 Winterthur, Switzerland
| | - Mario Scheel
- Synchrotron Soleil, 91192 Gif-sur-Yvette, France
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, 8057 Zurich, Switzerland; National Centre of Competence in Research, Kidney.CH, 8057 Zurich, Switzerland
| | | | - Bert Müller
- Biomaterials Science Center, Department of Biomedical Engineering, University of Basel, 4123 Allschwil, Switzerland; Biomaterials Science Center, Department of Clinical Research, University Hospital Basel, 4031 Basel, Switzerland
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25
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Zipser C, Pfender N, Kheram N, Boraschi A, Aguirre J, Ulrich N, Spirig J, Ansorge A, Betz M, Wanivenhaus F, Hupp M, Kurtcuoglu V, Farshad M, Curt A, Schubert M. Intraoperative monitoring of CSF pressure in patients with degenerative cervical myelopathy (COMP-CORD Study): a prospective cohort study. J Neurotrauma 2021; 39:300-310. [PMID: 34806912 DOI: 10.1089/neu.2021.0310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Degenerative cervical myelopathy (DCM) is hallmarked by spinal canal narrowing and related cord compression and myelopathy. CSF pressure dynamics are likely disturbed due to spinal canal stenosis. The study aims to investigate the diagnostic value of continuous intraoperative CSF pressure monitoring during surgical decompression. Prospective single center study (NCT02170155) with enrolment of DCM patients that underwent surgical decompression between December 2019 and May 2021. Data from N=17 patients were analyzed, symptom severity graded with the modified Japanese Orthopedic Score (mJOA). CSF pulsations were continuously monitored with a lumbar intrathecal catheter during surgical decompression. Mean patient age was 62±9 years (range 38-73; 8F), symptoms were mild-moderate in most patients (mean mJOA 14±2, range 10-18). Measurements were well tolerated without safety concerns. In 15/16 (94%) CSF pulsations increased at the time of surgical decompression. In one case, responsiveness could not be evaluated for technical reasons. Unexpected CSF pulsation decrease was related to adverse events (i.e., CSF leakage). Median CSF pulsation amplitudes increased from pre-decompression (0.52 mmHg [IQR 0.71]) to post-decompression (0.72 mmHg [IQR 0.96]) (P=0.001). Mean baseline CSF pressure increased with lower magnitude than pulsations, from 9.5±3.5 to 10.3±3.8 mmHg (P=0.003). Systematic relations of CSF pulsations were confined to surgical decompression, independent of arterial blood pressure (P=0.927) or heart rate (P=0.102). Intraoperative CSF pulsation monitoring was sensitive, timely, and specifically related to surgical decompression while in addition adverse events could be discerned. Further investigation of the clinical value of intraoperative guidance for decompression in complex DCM surgery is promising.
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Affiliation(s)
- Carl Zipser
- Balgrist University Hospital, 31031, Center for Paraplegia, Forchstrasse 340, Zürich, Zurich, Switzerland, 8008;
| | - Nikolai Pfender
- University of Zurich , Spinal Cord Injury Center Balgrist , Zurich , Switzerland;
| | - Najmeh Kheram
- Balgrist University Hospital, 31031, Center for Paraplegia, Zurich, Switzerland;
| | - Andrea Boraschi
- University of Zurich , Department of Physiology, Zurich , Switzerland;
| | - Jose Aguirre
- Balgrist University Hospital, 31031, Anesthesiology, Zurich, Switzerland;
| | - Nils Ulrich
- Balgrist University Hospital, 31031, Spine Surgery, Zurich, Switzerland;
| | - Jose Spirig
- Balgrist University Hospital, 31031, Spine Surgery, Zurich, Switzerland;
| | - Alexandre Ansorge
- Balgrist University Hospital, 31031, Spine Surgery, Zurich, Switzerland;
| | - Michael Betz
- University of Zurich , Spine Surgery, Zurich , Switzerland;
| | | | - Markus Hupp
- Uniklinik Balgrist, 31031, Forchstr. 340, Zurich, Switzerland, 8008;
| | - Vartan Kurtcuoglu
- University of Zurich , Department of Physiology, Zurich , Switzerland;
| | - Mazda Farshad
- University of Zurich , Spine Surgery, Zurich , Switzerland;
| | - Armin Curt
- University Hospital Balgrist, Spinal Cord Injury Center, Forchstrasse, Zurich, Switzerland, 8008;
| | - Martin Schubert
- Spinal cord Injury Center, University Hospital Balgrist, Forchstrasse 340, Zurich, Zurich, Switzerland, 8008;
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26
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Restin T, Gaspar M, Bassler D, Kurtcuoglu V, Scholkmann F, Haslbeck FB. Newborn Incubators Do Not Protect from High Noise Levels in the Neonatal Intensive Care Unit and Are Relevant Noise Sources by Themselves. Children (Basel) 2021; 8:704. [PMID: 34438595 PMCID: PMC8394397 DOI: 10.3390/children8080704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 08/09/2021] [Accepted: 08/13/2021] [Indexed: 11/24/2022]
Abstract
BACKGROUND While meaningful sound exposure has been shown to be important for newborn development, an excess of noise can delay the proper development of the auditory cortex. AIM The aim of this study was to assess the acoustic environment of a preterm baby in an incubator on a newborn intensive care unit (NICU). METHODS An empty but running incubator (Giraffe Omnibed, GE Healthcare) was used to evaluate the incubator frequency response with 60 measurements. In addition, a full day and night period outside and inside the incubator at the NICU of the University Hospital Zurich was acoustically analyzed. RESULTS The fan construction inside the incubator generates noise in the frequency range of 1.3-1.5 kHz with a weighted sound pressure level (SPL) of 40.5 dB(A). The construction of the incubator narrows the transmitted frequency spectrum of sound entering the incubator to lower frequencies, but it does not attenuate transient noises such as alarms or opening and closing of cabinet doors substantially. Alarms, as generated by the monitors, the incubator, and additional devices, still pass to the newborn. CONCLUSIONS The incubator does protect only insufficiently from noise coming from the NICUThe transmitted frequency spectrum is changed, limiting the impact of NICU noise on the neonate, but also limiting the neonate's perception of voices. The incubator, in particular its fan, as well as alarms from patient monitors are major sources of noise. Further optimizations with regard to the sound exposure in the NICU, as well as studies on the role of the incubator as a source and modulator, are needed to meet the preterm infants' multi-sensory needs.
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Affiliation(s)
- Tanja Restin
- Department of Neonatology, Newborn Research Zurich, University Hospital Zurich, 8091 Zurich, Switzerland; (D.B.); (F.S.); (F.B.H.)
- Institute of Physiology, University of Zurich, 8057 Zurich, Switzerland; (M.G.); (V.K.)
| | - Mikael Gaspar
- Institute of Physiology, University of Zurich, 8057 Zurich, Switzerland; (M.G.); (V.K.)
| | - Dirk Bassler
- Department of Neonatology, Newborn Research Zurich, University Hospital Zurich, 8091 Zurich, Switzerland; (D.B.); (F.S.); (F.B.H.)
| | - Vartan Kurtcuoglu
- Institute of Physiology, University of Zurich, 8057 Zurich, Switzerland; (M.G.); (V.K.)
| | - Felix Scholkmann
- Department of Neonatology, Newborn Research Zurich, University Hospital Zurich, 8091 Zurich, Switzerland; (D.B.); (F.S.); (F.B.H.)
| | - Friederike Barbara Haslbeck
- Department of Neonatology, Newborn Research Zurich, University Hospital Zurich, 8091 Zurich, Switzerland; (D.B.); (F.S.); (F.B.H.)
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von Petersdorff-Campen K, Abeken J, de Zélicourt D, Kurtcuoglu V, Meboldt M, Schmid Daners M. In Vitro Testing and Comparison of Additively Manufactured Polymer Impellers for the CentriMag Blood Pump. ASAIO J 2021; 67:306-313. [PMID: 33627605 DOI: 10.1097/mat.0000000000001220] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Additive manufacturing (AM) is an effective tool for accelerating knowledge gain in development processes, as it enables the production of complex prototypes at low cost and with short lead times. In the development of mechanical circulatory support, the use of cheap polymer-based AM techniques for prototype manufacturing allows more design variations to be tested, promoting a better understanding of the respective system and its optimization parameters. Here, we compare four commonly used AM processes for polymers with respect to manufacturing accuracy, surface roughness, and shape fidelity in an aqueous environment. Impeller replicas of the CentriMag blood pump were manufactured with each process and integrated into original pump housings. The assemblies were tested for hydraulic properties and hemolysis in reference to the commercially available pump. Computational fluid dynamic simulations were carried out to support the transfer of the results to other applications. In hydraulic testing, the deviation in pressure head and motor current of all additively manufactured replicas from the reference pump remained below 2% over the entire operating range of the pump. In contrast, significant deviations of up to 620% were observed in hemolysis testing. Only the replicas produced by stereolithography showed a nonsignificant deviation from the reference pump, which we attribute to the low surface roughness of parts manufactured thereby. The results suggest that there is a flow-dependent threshold of roughness above which a surface strongly contributes to cell lysis by promoting a hydraulically rough boundary flow.
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Affiliation(s)
- Kai von Petersdorff-Campen
- From the Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland and
| | - Jonas Abeken
- The Interface Group, Faculty of Medicine, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Diane de Zélicourt
- The Interface Group, Faculty of Medicine, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Faculty of Medicine, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Mirko Meboldt
- From the Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland and
| | - Marianne Schmid Daners
- From the Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland and
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28
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Rossinelli D, Fourestey G, Schmidt F, Busse B, Kurtcuoglu V. High-Throughput Lossy-to-Lossless 3D Image Compression. IEEE Trans Med Imaging 2021; 40:607-620. [PMID: 33095708 DOI: 10.1109/tmi.2020.3033456] [Citation(s) in RCA: 1] [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: 06/11/2023]
Abstract
The rapid increase in medical and biomedical image acquisition rates has opened up new avenues for image analysis, but has also introduced formidable challenges. This is evident, for example, in selective plane illumination microscopy where acquisition rates of about 1-4 GB/s sustained over several days have redefined the scale of I/O bandwidth required by image analysis tools. Although the effective bandwidth could, principally, be increased by lossy-to-lossless data compression, this is of limited value in practice due to the high computational demand of current schemes such as JPEG2000 that reach compression throughput of one order of magnitude below that of image acquisition. Here we present a novel lossy-to-lossless data compression scheme with a compression throughput well above 4 GB/s and compression rates and rate-distortion curves competitive with those achieved by JPEG2000 and JP3D.
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29
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Spiegelberg A, Stieglitz L, Kurtcuoglu V. Correction to: Why Hydrocephalus Patients Suffer When the Weather Changes: A New Hypothesis. Acta Neurochir Suppl 2021; 131:C3. [PMID: 35802148 DOI: 10.1007/978-3-030-59436-7_72] [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] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Affiliation(s)
- Andreas Spiegelberg
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland.
| | - Lennart Stieglitz
- Department of Neurosurgery, University Hospital Zurich, Zurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology and Neuroscience Center, University of Zurich, Zurich, Switzerland
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30
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Spiegelberg A, Krause M, Meixensberger J, Kurtcuoglu V. RAQ: a novel surrogate for the craniospinal pressure-volume relationship. Physiol Meas 2020; 41:094002. [PMID: 33021233 DOI: 10.1088/1361-6579/abb145] [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: 11/12/2022]
Abstract
OBJECTIVE The intracranial pressure-volume relation contains information relevant for diagnostics of hydrocephalus and other space-occupying pathologies. We aimed to design a noise-resilient surrogate for this relationship that can be calculated from intracranial pressure (ICP) signals. APPROACH The new surrogate, termed respiratory amplitude quotient (RAQ), characterizes the modulation of the cardiac pulse wave amplitude by the respiratory wave in the ICP time course. RAQ is defined as the ratio of the amplitude of the respiratory wave in the ICP signal to the amplitude of the respiration-induced variation in the course of the cardiac pulse wave amplitude. We validated the calculation of RAQ on synthetically generated ICP waveforms. We further extracted RAQ retrospectively from overnight ICP recordings in a cohort of hydrocephalus patients with aqueductal stenosis, age 55.8 ± 18.0 years, and a comparison group with hydrocephalus diagnosed by morphology in MRI, but not responsive to either external lumbar drainage or ventriculo-peritoneal shunting, age 72.5 ± 6.1 years. RAQ was determined for the full recordings, and separately for periods containing B-waves. MAIN RESULTS We found a mean difference of less than 2% between the calculated values of RAQ and the theoretically determined equivalent descriptors of the synthetic ICP waveforms. In the overnight recordings, we found significantly different RAQ values during B-waves in the aqueductal stenosis (0.86 ± 0.11) and non-responsive hydrocephalus patient groups (1.07 ± 0.20), p = 0.027. In contrast, there was no significant difference in other tested parameters, namely pressure-volume index, elastance coefficient, and resistance to outflow. Neither did we find significant difference when considering RAQ over the full recordings. SIGNIFICANCE Our results indicate that RAQ may function as a potential surrogate for the intracranial pressure-volume relation.
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Affiliation(s)
- Andreas Spiegelberg
- University of Zurich, The Interface Group, Institute of Physiology, Switzerland
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31
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Juchler N, Schilling S, Bijlenga P, Morel S, Rüfenacht D, Kurtcuoglu V, Hirsch S. Shape irregularity of the intracranial aneurysm lumen exhibits diagnostic value. Acta Neurochir (Wien) 2020; 162:2261-2270. [PMID: 32500254 DOI: 10.1007/s00701-020-04428-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [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: 02/10/2020] [Accepted: 05/22/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Morphological irregularity is linked to intracranial aneurysm wall instability and manifests in the lumen shape. Yet there is currently no consent on how to assess shape irregularity. The aims of this work are to quantify irregularity as perceived by clinicians, to break down irregularity into morphological attributes, and to relate these to clinically relevant factors such as rupture status, aneurysm location, and patient age or sex. METHODS Thirteen clinicians and 26 laypersons assessed 134 aneurysm lumen segmentations in terms of overall perceived irregularity and five different morphological attributes (presence/absence of a rough surface, blebs, lobules, asymmetry, complex geometry of the parent vasculature). We examined rater agreement and compared the ratings with clinical factors by means of regression analysis or binary classification. RESULTS Using rank-based aggregation, the irregularity ratings of clinicians and laypersons did not differ statistically. Perceived irregularity showed good agreement with curvature (coefficient of determination R2 = 0.68 ± 0.08) and was modeled very accurately using the five morphological rating attributes plus shape elongation (R2 = 0.95 ± 0.02). In agreement with previous studies, irregularity was associated with aneurysm rupture status (AUC = 0.81 ± 0.08); adding aneurysm location as an explanatory variable increased the AUC to 0.87 ± 0.09. Besides irregularity, perceived asymmetry, presence of blebs or lobules, aneurysm size, non-sphericity, and curvature were linked to rupture. No association was found between morphology and any of patient sex, age, and history of smoking or hypertension. Aneurysm size was linked to morphology. CONCLUSIONS Irregular lumen shape carries significant information on the aneurysm's disease status. Irregularity constitutes a continuous parameter that shows a strong association with the rupture status. To improve the objectivity of morphological assessment, we suggest examining shape through six different morphological attributes, which can characterize irregularity accurately.
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Affiliation(s)
- Norman Juchler
- Institute of Applied Simulation, Zurich University of Applied Sciences, Wädenswil, Switzerland.
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland.
| | - Sabine Schilling
- Institute of Applied Simulation, Zurich University of Applied Sciences, Wädenswil, Switzerland
- Institute of Tourism ITW, Lucerne University of Applied Sciences and Arts, Lucerne, Switzerland
| | - Philippe Bijlenga
- Neurosurgery Division, Department of Clinical Neurosciences, Geneva University Hospital and Faculty of Medicine, Geneva, Switzerland
| | - Sandrine Morel
- Neurosurgery Division, Department of Clinical Neurosciences, Geneva University Hospital and Faculty of Medicine, Geneva, Switzerland
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | | | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
- National Center of Competence in Research, Kidney.CH, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Sven Hirsch
- Institute of Applied Simulation, Zurich University of Applied Sciences, Wädenswil, Switzerland.
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32
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Detmer FJ, Hadad S, Chung BJ, Mut F, Slawski M, Juchler N, Kurtcuoglu V, Hirsch S, Bijlenga P, Uchiyama Y, Fujimura S, Yamamoto M, Murayama Y, Takao H, Koivisto T, Frösen J, Cebral JR. Extending statistical learning for aneurysm rupture assessment to Finnish and Japanese populations using morphology, hemodynamics, and patient characteristics. Neurosurg Focus 2020; 47:E16. [PMID: 31261120 DOI: 10.3171/2019.4.focus19145] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [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: 02/28/2019] [Accepted: 04/09/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Incidental aneurysms pose a challenge for physicians, who need to weigh the rupture risk against the risks associated with treatment and its complications. A statistical model could potentially support such treatment decisions. A recently developed aneurysm rupture probability model performed well in the US data used for model training and in data from two European cohorts for external validation. Because Japanese and Finnish patients are known to have a higher aneurysm rupture risk, the authors' goals in the present study were to evaluate this model using data from Japanese and Finnish patients and to compare it with new models trained with Finnish and Japanese data. METHODS Patient and image data on 2129 aneurysms in 1472 patients were used. Of these aneurysm cases, 1631 had been collected mainly from US hospitals, 249 from European (other than Finnish) hospitals, 147 from Japanese hospitals, and 102 from Finnish hospitals. Computational fluid dynamics simulations and shape analyses were conducted to quantitatively characterize each aneurysm's shape and hemodynamics. Next, the previously developed model's discrimination was evaluated using the Finnish and Japanese data in terms of the area under the receiver operating characteristic curve (AUC). Models with and without interaction terms between patient population and aneurysm characteristics were trained and evaluated including data from all four cohorts obtained by repeatedly randomly splitting the data into training and test data. RESULTS The US model's AUC was reduced to 0.70 and 0.72, respectively, in the Finnish and Japanese data compared to 0.82 and 0.86 in the European and US data. When training the model with Japanese and Finnish data, the average AUC increased only slightly for the Finnish sample (to 0.76 ± 0.16) and Finnish and Japanese cases combined (from 0.74 to 0.75 ± 0.14) and decreased for the Japanese data (to 0.66 ± 0.33). In models including interaction terms, the AUC in the Finnish and Japanese data combined increased significantly to 0.83 ± 0.10. CONCLUSIONS Developing an aneurysm rupture prediction model that applies to Japanese and Finnish aneurysms requires including data from these two cohorts for model training, as well as interaction terms between patient population and the other variables in the model. When including this information, the performance of such a model with Japanese and Finnish data is close to its performance with US or European data. These results suggest that population-specific differences determine how hemodynamics and shape associate with rupture risk in intracranial aneurysms.
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Affiliation(s)
| | | | - Bong Jae Chung
- 2Department of Mathematical Sciences, Montclair State University, Montclair, New Jersey
| | | | - Martin Slawski
- 3Statistics Department, George Mason University, Fairfax, Virginia
| | - Norman Juchler
- 4Institute of Applied Simulation, ZHAW University of Applied Sciences, Wädenswil, Switzerland.,5The Interface Group, Institute of Physiology, University of Zürich, Switzerland
| | - Vartan Kurtcuoglu
- 5The Interface Group, Institute of Physiology, University of Zürich, Switzerland
| | - Sven Hirsch
- 4Institute of Applied Simulation, ZHAW University of Applied Sciences, Wädenswil, Switzerland
| | - Philippe Bijlenga
- 6Clinical Neurosciences Department, University of Geneva, Switzerland
| | - Yuya Uchiyama
- 7Graduate School of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan.,Departments of8Innovation for Medical Information Technology and
| | - Soichiro Fujimura
- 7Graduate School of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan.,Departments of8Innovation for Medical Information Technology and
| | - Makoto Yamamoto
- 9Department of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan; and
| | - Yuichi Murayama
- 10Neurosurgery, The Jikei University of Medicine, Tokyo, Japan
| | - Hiroyuki Takao
- 7Graduate School of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan.,Departments of8Innovation for Medical Information Technology and.,10Neurosurgery, The Jikei University of Medicine, Tokyo, Japan
| | - Timo Koivisto
- 11Hemorrhagic Brain Pathology Research Group, Department of Neurosurgery, Kuopio University Hospital, Kuopio, Finland
| | - Juhana Frösen
- 11Hemorrhagic Brain Pathology Research Group, Department of Neurosurgery, Kuopio University Hospital, Kuopio, Finland
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33
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Kuo W, Le NA, Spingler B, Wenger RH, Kipar A, Hetzel U, Schulz G, Müller B, Kurtcuoglu V. Simultaneous Three-Dimensional Vascular and Tubular Imaging of Whole Mouse Kidneys With X-ray μCT. Microsc Microanal 2020; 26:731-740. [PMID: 32627730 DOI: 10.1017/s1431927620001725] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Concurrent three-dimensional imaging of the renal vascular and tubular systems on the whole-kidney scale with capillary level resolution is labor-intensive and technically difficult. Approaches based on vascular corrosion casting and X-ray micro computed tomography (μCT), for example, suffer from vascular filling artifacts and necessitate imaging with an additional modality to acquire tubules. In this work, we report on a new sample preparation, image acquisition, and quantification protocol for simultaneous vascular and tubular μCT imaging of whole, uncorroded mouse kidneys. The protocol consists of vascular perfusion with the water-soluble, aldehyde-fixable, polymeric X-ray contrast agent XlinCA, followed by laboratory-source μCT imaging and structural analysis using the freely available Fiji/ImageJ software. We achieved consistent filling of the entire capillary bed and staining of the tubules in the cortex and outer medulla. After imaging at isotropic voxel sizes of 3.3 and 4.4 μm, we segmented vascular and tubular systems and quantified luminal volumes, surface areas, diffusion distances, and vessel path lengths. This protocol permits the analysis of vascular and tubular parameters with higher reliability than vascular corrosion casting, less labor than serial sectioning and leaves tissue intact for subsequent histological examination with light and electron microscopy.
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Affiliation(s)
- Willy Kuo
- University of Zurich, Institute of Physiology, Winterthurerstrasse 190, 8057Zurich, Switzerland
- University of Zurich, National Centre of Competence in Research, Kidney. CH, Winterthurerstrasse 190, 8057Zurich, Switzerland
- University of Basel, Biomaterials Science Center, Department of Biomedical Engineering, Gewerbestrasse 14, 4123Allschwil, Switzerland
| | - Ngoc An Le
- University of Zurich, Department of Chemistry, Winterthurerstrasse 190, 8057Zurich, Switzerland
| | - Bernhard Spingler
- University of Zurich, Department of Chemistry, Winterthurerstrasse 190, 8057Zurich, Switzerland
| | - Roland H Wenger
- University of Zurich, Institute of Physiology, Winterthurerstrasse 190, 8057Zurich, Switzerland
- University of Zurich, National Centre of Competence in Research, Kidney. CH, Winterthurerstrasse 190, 8057Zurich, Switzerland
| | - Anja Kipar
- University of Zurich, Laboratory for Animal Model Pathology (LAMP), Institute of Veterinary Pathology, Vetsuisse Faculty, Winterthurerstrasse 268, 8057Zurich, Switzerland
| | - Udo Hetzel
- University of Zurich, Electron Microscopy Unit, Institute of Veterinary Pathology, Vetsuisse Faculty, Winterthurerstrasse 268, 8057Zurich, Switzerland
| | - Georg Schulz
- University of Basel, Biomaterials Science Center, Department of Biomedical Engineering, Gewerbestrasse 14, 4123Allschwil, Switzerland
| | - Bert Müller
- University of Basel, Biomaterials Science Center, Department of Biomedical Engineering, Gewerbestrasse 14, 4123Allschwil, Switzerland
| | - Vartan Kurtcuoglu
- University of Zurich, Institute of Physiology, Winterthurerstrasse 190, 8057Zurich, Switzerland
- University of Zurich, National Centre of Competence in Research, Kidney. CH, Winterthurerstrasse 190, 8057Zurich, Switzerland
- University of Zurich, Zurich Center for Integrative Human Physiology, 8057Zurich, Switzerland
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34
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Juchler N, Schilling S, Glüge S, Bijlenga P, Rüfenacht D, Kurtcuoglu V, Hirsch S. Radiomics approach to quantify shape irregularity from crowd-based qualitative assessment of intracranial aneurysms. Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization 2020. [DOI: 10.1080/21681163.2020.1728579] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Norman Juchler
- Institute of Applied Simulation, Zurich University of Applied Sciences, Waedenswil, Switzerland
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Sabine Schilling
- Institute of Applied Simulation, Zurich University of Applied Sciences, Waedenswil, Switzerland
- Institute of Tourism ITW, Lucerne University of Applied Sciences and Arts, Lucerne, Switzerland
| | - Stefan Glüge
- Institute of Applied Simulation, Zurich University of Applied Sciences, Waedenswil, Switzerland
| | - Philippe Bijlenga
- Neurosurgery, Clinical Neurosciences Department, University of Geneva, Geneva, Switzerland
| | - Daniel Rüfenacht
- Department of Neuroradiology, Clinic Hirslanden, Zurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
- National Center of Competence in Research, Kidney.CH, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Sven Hirsch
- Institute of Applied Simulation, Zurich University of Applied Sciences, Waedenswil, Switzerland
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35
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Le NA, Kuo W, Müller B, Kurtcuoglu V, Spingler B. Crosslinkable polymeric contrast agent for high-resolution X-ray imaging of the vascular system. Chem Commun (Camb) 2020; 56:5885-5888. [DOI: 10.1039/c9cc09883f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A contrast agent for X-ray micro computed tomography (μCT), called XlinCA, that combines reliable perfusion and permanent retention and contrast properties, was developed for ex vivo imaging.
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Affiliation(s)
- Ngoc An Le
- Department of Chemistry
- University of Zurich
- 8057 Zurich
- Switzerland
| | - Willy Kuo
- Institute of Physiology
- University of Zurich
- 8057 Zurich
- Switzerland
- National Centre of Competence in Research
| | - Bert Müller
- Biomaterials Science Center
- Department of Biomedical Engineering
- University of Basel
- 4123 Allschwil
- Switzerland
| | - Vartan Kurtcuoglu
- Institute of Physiology
- University of Zurich
- 8057 Zurich
- Switzerland
- National Centre of Competence in Research
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36
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Kriesi C, Steinert M, Marmaras A, Danzer C, Meskenaite V, Kurtcuoglu V. Integrated Flow Chamber System for Live Cell Microscopy. Front Bioeng Biotechnol 2019; 7:91. [PMID: 31119129 PMCID: PMC6504681 DOI: 10.3389/fbioe.2019.00091] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [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: 01/31/2019] [Accepted: 04/12/2019] [Indexed: 11/13/2022] Open
Abstract
In vitro quantification of the effect of mechanical loads on cells by live microscopy requires precise control of load and culture environment. Corresponding systems are often bulky, their setup and maintenance are time consuming, or the cell yield is low. Here, we show the design and initial testing of a new cell culture system that fits on standard light microscope stages. Based on the parallel plate principle, the system allows for live microscopy of cells exposed to flow-induced shear stress, features short setup time and requires little user interaction. An integrated feedback-controlled heater and a bubble trap enable long observation times. The key design feature is the possibility for quick exchange of the cultured cells. We present first test results that focus on verifying the robustness, biocompatibility, and ease of use of the device.
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Affiliation(s)
- Carlo Kriesi
- TrollLABS, Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology, Trondheim, Norway
| | - Martin Steinert
- TrollLABS, Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology, Trondheim, Norway
| | - Anastasios Marmaras
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Claudia Danzer
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Virginia Meskenaite
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
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37
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Taslimifar M, Buoso S, Verrey F, Kurtcuoglu V. Propagation of Plasma L-Phenylalanine Concentration Fluctuations to the Neurovascular Unit in Phenylketonuria: An in silico Study. Front Physiol 2019; 10:360. [PMID: 31105574 PMCID: PMC6454150 DOI: 10.3389/fphys.2019.00360] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [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: 10/23/2018] [Accepted: 03/14/2019] [Indexed: 01/21/2023] Open
Abstract
Phenylketonuria (PKU) is an inherited metabolic disease characterized by abnormally high concentrations of the essential amino acid L-phenylalanine (Phe) in blood plasma caused by reduced activity of phenylalanine hydroxylase (PAH). While numerous studies have shown association between high plasma Phe concentration and intellectual impairment, it is not clear whether increased Phe fluctuations also observed in PKU affect the brain as well. To investigate this, time-resolved in vivo data on Phe and competing large neutral amino acid (LNAA) concentrations in neurons are needed, but cannot be acquired readily with current methods. We have used in silico modeling as an alternative approach to characterize the interactive dynamics of Phe and competing LNAAs (CL) in the neurovascular unit (NVU). Our results suggest that plasma Phe fluctuations can propagate into the NVU cells and change there the concentration of LNAAs, with the highest magnitude of this effect observed at low frequency and high amplitude-to-mean ratio of the plasma Phe concentration fluctuations. Our model further elucidates the effect of therapeutic LNAA supplementation in PKU, showing how abnormal concentrations of Phe and CL in the NVU move thereby toward normal physiologic levels.
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Affiliation(s)
- Mehdi Taslimifar
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland.,Epithelial Transport Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Stefano Buoso
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland.,Institute for Diagnostic and Interventional Radiology, Zurich University Hospital, Zurich, Switzerland
| | - Francois Verrey
- Epithelial Transport Group, Institute of Physiology, University of Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.,National Center of Competence in Research, Kidney Control of Homeostasis, Zurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.,National Center of Competence in Research, Kidney Control of Homeostasis, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
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38
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Wiegmann L, Thamsen B, de Zélicourt D, Granegger M, Boës S, Schmid Daners M, Meboldt M, Kurtcuoglu V. Fluid Dynamics in the HeartMate 3: Influence of the Artificial Pulse Feature and Residual Cardiac Pulsation. Artif Organs 2018; 43:363-376. [PMID: 30129977 DOI: 10.1111/aor.13346] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [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: 05/24/2018] [Revised: 07/22/2018] [Accepted: 08/15/2018] [Indexed: 12/17/2022]
Abstract
Ventricular assist devices (VADs), among which the HeartMate 3 (HM3) is the latest clinically approved representative, are often the therapy of choice for patients with end-stage heart failure. Despite advances in the prevention of pump thrombosis, rates of stroke and bleeding remain high. These complications are attributed to the flow field within the VAD, among other factors. One of the HM3's characteristic features is an artificial pulse that changes the rotor speed periodically by 4000 rpm, which is meant to reduce zones of recirculation and stasis. In this study, we investigated the effect of this speed modulation on the flow fields and stresses using high-resolution computational fluid dynamics. To this end, we compared Eulerian and Lagrangian features of the flow fields during constant pump operation, during operation with the artificial pulse feature, and with the effect of the residual native cardiac cycle. We observed good washout in all investigated situations, which may explain the low incidence rates of pump thrombosis. The artificial pulse had no additional benefit on scalar washout performance, but it induced rapid variations in the flow velocity and its gradients. This may be relevant for the removal of deposits in the pump. Overall, we found that viscous stresses in the HM3 were lower than in other current VADs. However, the artificial pulse substantially increased turbulence, and thereby also total stresses, which may contribute to clinically observed issues related to hemocompatibility.
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Affiliation(s)
- Lena Wiegmann
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Bente Thamsen
- Pediatric Cardiovascular Surgery, Pediatric Heart Center, Department of Surgery, University Children's Hospital Zurich, Zurich, Switzerland.,Children's Research Center, University Children's Hospital Zurich, Switzerland.,Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Diane de Zélicourt
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland.,Children's Research Center, University Children's Hospital Zurich, Switzerland
| | - Marcus Granegger
- Pediatric Cardiovascular Surgery, Pediatric Heart Center, Department of Surgery, University Children's Hospital Zurich, Zurich, Switzerland
| | - Stefan Boës
- Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Marianne Schmid Daners
- Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Mirko Meboldt
- Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland.,National Center of Competence in Research, Kidney CH, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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39
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Taslimifar M, Buoso S, Verrey F, Kurtcuoglu V. Functional Polarity of Microvascular Brain Endothelial Cells Supported by Neurovascular Unit Computational Model of Large Neutral Amino Acid Homeostasis. Front Physiol 2018; 9:171. [PMID: 29593549 PMCID: PMC5859092 DOI: 10.3389/fphys.2018.00171] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [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: 11/16/2017] [Accepted: 02/20/2018] [Indexed: 11/13/2022] Open
Abstract
The homeostatic regulation of large neutral amino acid (LNAA) concentration in the brain interstitial fluid (ISF) is essential for proper brain function. LNAA passage into the brain is primarily mediated by the complex and dynamic interactions between various solute carrier (SLC) transporters expressed in the neurovascular unit (NVU), among which SLC7A5/LAT1 is considered to be the major contributor in microvascular brain endothelial cells (MBEC). The LAT1-mediated trans-endothelial transport of LNAAs, however, could not be characterized precisely by available in vitro and in vivo standard methods so far. To circumvent these limitations, we have incorporated published in vivo data of rat brain into a robust computational model of NVU-LNAA homeostasis, allowing us to evaluate hypotheses concerning LAT1-mediated trans-endothelial transport of LNAAs across the blood brain barrier (BBB). We show that accounting for functional polarity of MBECs with either asymmetric LAT1 distribution between membranes and/or intrinsic LAT1 asymmetry with low intraendothelial binding affinity is required to reproduce the experimentally measured brain ISF response to intraperitoneal (IP) L-tyrosine and L-phenylalanine injection. On the basis of these findings, we have also investigated the effect of IP administrated L-tyrosine and L-phenylalanine on the dynamics of LNAAs in MBECs, astrocytes and neurons. Finally, the computational model was shown to explain the trans-stimulation of LNAA uptake across the BBB observed upon ISF perfusion with a competitive LAT1 inhibitor.
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Affiliation(s)
- Mehdi Taslimifar
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland.,Epithelial Transport Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Stefano Buoso
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland.,Institute for Diagnostic and Interventional Radiology, Zurich University Hospital, Zurich, Switzerland
| | - Francois Verrey
- Epithelial Transport Group, Institute of Physiology, University of Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.,National Center of Competence in Research, Kidney.CH, Zurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.,National Center of Competence in Research, Kidney.CH, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
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40
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Spiegelberg A, Krause M, Meixensberger J, Seifert B, Kurtcuoglu V. Significant Association of Slow Vasogenic ICP Waves with Normal Pressure Hydrocephalus Diagnosis. Acta Neurochir Suppl 2018; 126:243-246. [PMID: 29492569 DOI: 10.1007/978-3-319-65798-1_49] [Citation(s) in RCA: 5] [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] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
OBJECTIVE We aimed to test whether there is an association of slow vasogenic wave (SVW) occurrence with positive response to external lumbar drainage (ELD) and ventriculoperitoneal shunting and to design a method for the recognition and quantification of SVWs in the intracranial pressure (ICP) signal. MATERIALS AND METHODS We constructed SVW templates using normalized sine waves. We calculated the cross-correlation between the respective SVW template and the ICP signal. This was followed by shifting the templates forward and performing the cross-correlation analysis again until the end of the recording. Cross-correlation values above a threshold were considered to be indicative of SVWs. This threshold was previously determined and validated on a sample of ICP records of six patients. We calculated the root mean square of the recognized SVW periods as a measure of signal strength. Time-averaged signal strength was calculated over the full recording time (ICPSmean) and over the wave periods (ICPS). RESULTS We determined ICPS and ICPSmean in recordings of 2 groups of patients presenting with Hakim's triad: 26 normal pressure hydrocephalus (NPH) patients and 20 non-NPH patients. We then tested whether there was an association between ICPS or ICPSmean and the respective diagnosis using a Mann-Whitney test. We found significant association between ICPS (p = 0.014) and ICPSmean (p = 0.022) and the diagnoses. CONCLUSIONS The described method based on pattern recognition in the time domain is suitable for the detection and quantification of SVWs in ICP signals. We found a significant association between the occurrence of SVWs and independent NPH diagnosis.
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Affiliation(s)
- Andreas Spiegelberg
- The Interface Group, Institute of Physiology, University of Zurich, Zürich, Switzerland.
| | - Matthias Krause
- Klinik und Poliklinik für Neurochirurgie, Universitaetsklinikum Leipzig AoeR, Leipzig, Germany
| | - Juergen Meixensberger
- Klinik und Poliklinik für Neurochirurgie, Universitaetsklinikum Leipzig AoeR, Leipzig, Germany
| | - Burkhardt Seifert
- Department of Biostatistics, Epidemiology, Biostatistics and Prevention Institute (EBPI), University of Zurich, Zurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Zürich, Switzerland
- Zurich Center for Integrative Human Physiology and Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
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41
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Siallagan D, Loke YH, Olivieri L, Opfermann J, Ong CS, de Zélicourt D, Petrou A, Daners MS, Kurtcuoglu V, Meboldt M, Nelson K, Vricella L, Johnson J, Hibino N, Krieger A. Virtual surgical planning, flow simulation, and 3-dimensional electrospinning of patient-specific grafts to optimize Fontan hemodynamics. J Thorac Cardiovasc Surg 2017; 155:1734-1742. [PMID: 29361303 DOI: 10.1016/j.jtcvs.2017.11.068] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 11/09/2017] [Accepted: 11/27/2017] [Indexed: 10/18/2022]
Abstract
BACKGROUND Despite advances in the Fontan procedure, there is an unmet clinical need for patient-specific graft designs that are optimized for variations in patient anatomy. The objective of this study is to design and produce patient-specific Fontan geometries, with the goal of improving hepatic flow distribution (HFD) and reducing power loss (Ploss), and manufacturing these designs by electrospinning. METHODS Cardiac magnetic resonance imaging data from patients who previously underwent a Fontan procedure (n = 2) was used to create 3-dimensional models of their native Fontan geometry using standard image segmentation and geometry reconstruction software. For each patient, alternative designs were explored in silico, including tube-shaped and bifurcated conduits, and their performance in terms of Ploss and HFD probed by computational fluid dynamic (CFD) simulations. The best-performing options were then fabricated using electrospinning. RESULTS CFD simulations showed that the bifurcated conduit improved HFD between the left and right pulmonary arteries, whereas both types of conduits reduced Ploss. In vitro testing with a flow-loop chamber supported the CFD results. The proposed designs were then successfully electrospun into tissue-engineered vascular grafts. CONCLUSIONS Our unique virtual cardiac surgery approach has the potential to improve the quality of surgery by manufacturing patient-specific designs before surgery, that are also optimized with balanced HFD and minimal Ploss, based on refinement of commercially available options for image segmentation, computer-aided design, and flow simulations.
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Affiliation(s)
- Dominik Siallagan
- Sheikh Zayed Institute for Surgical Innovation, Children's National Medical Center, Washington, DC; Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Yue-Hin Loke
- Division of Cardiology, Children's National Health System, Washington, DC
| | - Laura Olivieri
- Sheikh Zayed Institute for Surgical Innovation, Children's National Medical Center, Washington, DC; Division of Cardiology, Children's National Health System, Washington, DC
| | - Justin Opfermann
- Sheikh Zayed Institute for Surgical Innovation, Children's National Medical Center, Washington, DC
| | - Chin Siang Ong
- Division of Cardiac Surgery, Johns Hopkins Hospital, Baltimore, Md
| | - Diane de Zélicourt
- The Interface Group, Institute of Physiology, University of Zürich, Zurich, Switzerland; Swiss National Centre of Competence in Research, Kidney Control of Homeostasis, Zurich, Switzerland
| | - Anastasios Petrou
- Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Marianne Schmid Daners
- Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zürich, Zurich, Switzerland; Swiss National Centre of Competence in Research, Kidney Control of Homeostasis, Zurich, Switzerland
| | - Mirko Meboldt
- Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | | | - Luca Vricella
- Division of Cardiac Surgery, Johns Hopkins Hospital, Baltimore, Md
| | | | - Narutoshi Hibino
- Division of Cardiac Surgery, Johns Hopkins Hospital, Baltimore, Md.
| | - Axel Krieger
- Sheikh Zayed Institute for Surgical Innovation, Children's National Medical Center, Washington, DC; Department of Mechanical Engineering, University of Maryland, College Park, Md
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42
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Wiegmann L, Boës S, de Zélicourt D, Thamsen B, Schmid Daners M, Meboldt M, Kurtcuoglu V. Blood Pump Design Variations and Their Influence on Hydraulic Performance and Indicators of Hemocompatibility. Ann Biomed Eng 2017; 46:417-428. [DOI: 10.1007/s10439-017-1951-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 10/25/2017] [Indexed: 12/11/2022]
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43
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Wiegmann L, de Zélicourt DA, Speer O, Muller A, Goede JS, Seifert B, Kurtcuoglu V. Influence of Standard Laboratory Procedures on Measures of Erythrocyte Damage. Front Physiol 2017; 8:731. [PMID: 29042854 PMCID: PMC5632557 DOI: 10.3389/fphys.2017.00731] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [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: 06/12/2017] [Accepted: 09/08/2017] [Indexed: 01/24/2023] Open
Abstract
The ability to characterize the mechanical properties of erythrocytes is important in clinical and research contexts: to diagnose and monitor hematologic disorders, as well as to optimize the design of cardiovascular implants and blood circulating devices with respect to blood damage. However, investigation of red blood cell (RBC) properties generally involves preparatory and processing steps. Even though these impose mechanical stresses on cells, little is known about their impact on the final measurement results. In this study, we investigated the effect of centrifuging, vortexing, pipetting, and high pressures on several markers of mechanical blood damage and RBC membrane properties. Using human venous blood, we analyzed erythrocyte damage by measuring free hemoglobin, phosphatidylserine exposure by flow cytometry, RBC deformability by ektacytometry and the parameters of a complete blood count. We observed increased levels of free hemoglobin for all tested procedures. The release of hemoglobin into plasma depended significantly on the level of stress. Elevated pressures and centrifuging also altered mean cell volume (MCV) and mean corpuscular hemoglobin (MCH), suggesting changes in erythrocyte population, and membrane properties. Our results show that the effects of blood handling can significantly influence erythrocyte damage metrics. Careful quantification of this influence as well as other unwanted secondary effects should thus be included in experimental protocols and accounted for in clinical laboratories.
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Affiliation(s)
- Lena Wiegmann
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Diane A de Zélicourt
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland.,National Center of Competence in Research, Kidney.CH, Zurich, Switzerland
| | - Oliver Speer
- Division of Haematology, University Children's Hospital Zurich, Zurich, Switzerland
| | - Alissa Muller
- Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Jeroen S Goede
- Department of Haematology, Kantonsspital Winterthur, Winterthur, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Burkhardt Seifert
- Department of Biostatistics, Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland.,National Center of Competence in Research, Kidney.CH, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
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44
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Gehlen M, Eklund A, Kurtcuoglu V, Malm J, Schmid Daners M. Comparison of anti-siphon devices-how do they affect CSF dynamics in supine and upright posture? Acta Neurochir (Wien) 2017; 159:1389-1397. [PMID: 28660395 DOI: 10.1007/s00701-017-3249-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [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: 03/06/2017] [Accepted: 06/07/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND Three different types of anti-siphon devices (ASDs) have been developed to counteract siphoning-induced overdrainage in upright posture. However, it is not known how the different ASDs affect CSF dynamics under the complex pressure environment seen in clinic due to postural changes. We investigated which ASDs can avoid overdrainage in upright posture best without leading to CSF accumulation. METHODS Three shunts each of the types Codman Hakim with SiphonGuard (flow-regulated), Miethke miniNAV with proSA (gravitational), and Medtronic Delta (membrane controlled) were tested. The shunts were compared on a novel in vitro setup that actively emulates the physiology of a shunted patient. This testing method allows determining the CSF drainage rates, resulting CSF volume, and intracranial pressure in the supine, sitting, and standing posture. RESULTS The flow-regulated ASDs avoided increased drainage by closing their primary flow path when drainage exceeded 1.39 ± 0.42 mL/min. However, with intraperitoneal pressure increased in standing posture, we observed reopening of the ASD in 3 out of 18 experiment repetitions. The adjustable gravitational ASDs allow independent opening pressures in horizontal and vertical orientation, but they did not provide constant drainage in upright posture (0.37 ± 0.03 mL/min and 0.26 ± 0.03 mL/min in sitting and standing posture, respectively). Consequently, adaptation to the individual patient is critical. The membrane-controlled ASDs stopped drainage in upright posture. This eliminates the risk of overdrainage, but leads to CSF accumulation up to the volume observed without shunting when the patient is upright. CONCLUSIONS While all tested ASDs reduced overdrainage, their actual performance will depend on a patient's specific needs because of the large variation in the way the ASDs influence CSF dynamics: while the flow-regulated shunts provide continuous drainage in upright posture, the gravitational ASDs allow and require additional adaptation, and the membrane-controlled ASDs show robust siphon prevention by a total stop of drainage.
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Affiliation(s)
- Manuel Gehlen
- Institute for Dynamic Systems and Control, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Anders Eklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Jan Malm
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - Marianne Schmid Daners
- Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Tannenstrasse 3, CLA G 21.1, 8092, Zürich, Switzerland.
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45
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Adam A, Robison J, Lu J, Jose R, Badran N, Vivas-Buitrago T, Rigamonti D, Sattar A, Omoush O, Hammad M, Dawood M, Maghaslah M, Belcher T, Carson K, Hoffberger J, Jusué Torres I, Foley S, Yasar S, Thai QA, Wemmer J, Klinge P, Al-Mutawa L, Al-Ghamdi H, Carson KA, Asgari M, de Zélicourt D, Kurtcuoglu V, Garnotel S, Salmon S, Balédent O, Lokossou A, Page G, Balardy L, Czosnyka Z, Payoux P, Schmidt EA, Zitoun M, Sevestre MA, Alperin N, Baudracco I, Craven C, Matloob S, Thompson S, Haylock Vize P, Thorne L, Watkins LD, Toma AK, Bechter K, Pong AC, Jugé L, Bilston LE, Cheng S, Bradley W, Hakim F, Ramón JF, Cárdenas MF, Davidson JS, García C, González D, Bermúdez S, Useche N, Mejía JA, Mayorga P, Cruz F, Martinez C, Matiz MC, Vallejo M, Ghotme K, Soto HA, Riveros D, Buitrago A, Mora M, Murcia L, Bermudez S, Cohen D, Dasgupta D, Curtis C, Domínguez L, Remolina AJ, Grijalba MA, Whitehouse KJ, Edwards RJ, Eleftheriou A, Lundin F, Fountas KN, Kapsalaki EZ, Smisson HF, Robinson JS, Fritsch MJ, Arouk W, Garzon M, Kang M, Sandhu K, Baghawatti D, Aquilina K, James G, Thompson D, Gehlen M, Schmid Daners M, Eklund A, Malm J, Gomez D, Guerra M, Jara M, Flores M, Vío K, Moreno I, Rodríguez S, Ortega E, Rodríguez EM, McAllister JP, Guerra MM, Morales DM, Sival D, Jimenez A, Limbrick DD, Ishikawa M, Yamada S, Yamamoto K, Junkkari A, Häyrinen A, Rauramaa T, Sintonen H, Nerg O, Koivisto AM, Roine RP, Viinamäki H, Soininen H, Luikku A, Jääskeläinen JE, Leinonen V, Kehler U, Lilja-Lund O, Kockum K, Larsson EM, Riklund K, Söderström L, Hellström P, Laurell K, Kojoukhova M, Sutela A, Vanninen R, Vanha KI, Timonen M, Rummukainen J, Korhonen V, Helisalmi S, Solje E, Remes AM, Huovinen J, Paananen J, Hiltunen M, Kurki M, Martin B, Loth F, Luciano M, Luikku AJ, Hall A, Herukka SK, Mattila J, Lötjönen J, Alafuzoff I, Jurjević I, Miyajima M, Nakajima M, Murai H, Shin T, Kawaguchi D, Akiba C, Ogino I, Karagiozov K, Arai H, Reis RC, Teixeira MJ, Valêncio CG, da Vigua D, Almeida-Lopes L, Mancini MW, Pinto FCG, Maykot RH, Calia G, Tornai J, Silvestre SSS, Mendes G, Sousa V, Bezerra B, Dutra P, Modesto P, Oliveira MF, Petitto CE, Pulhorn H, Chandran A, McMahon C, Rao AS, Jumaly M, Solomon D, Moghekar A, Relkin N, Hamilton M, Katzen H, Williams M, Bach T, Zuspan S, Holubkov R, Rigamonti A, Clemens G, Sharkey P, Sanyal A, Sankey E, Rigamonti K, Naqvi S, Hung A, Schmidt E, Ory-Magne F, Gantet P, Guenego A, Januel AC, Tall P, Fabre N, Mahieu L, Cognard C, Gray L, Buttner-Ennever JA, Takagi K, Onouchi K, Thompson SD, Thorne LD, Tully HM, Wenger TL, Kukull WA, Doherty D, Dobyns WB, Moran D, Vakili S, Patel MA, Elder B, Goodwin CR, Crawford JA, Pletnikov MV, Xu J, Blitz A, Herzka DA, Guerrero-Cazares H, Quiñones-Hinojosa A, Mori S, Saavedra P, Treviño H, Maitani K, Ziai WC, Eslami V, Nekoovaght-Tak S, Dlugash R, Yenokyan G, McBee N, Hanley DF. Abstracts from Hydrocephalus 2016. Fluids Barriers CNS 2017; 14:15. [PMID: 28929972 PMCID: PMC5471936 DOI: 10.1186/s12987-017-0054-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- A Adam
- Johns Hopkins University, Baltimore, MD, USA.,Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA.,Johns Hopkins Biostatistics Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.,Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - J Robison
- Johns Hopkins University, Baltimore, MD, USA.,Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA.,Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - J Lu
- Johns Hopkins University, Baltimore, MD, USA.,Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA.,Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - R Jose
- Johns Hopkins Aramco Healthcare, Dhahran, Saudi Arabia
| | - N Badran
- Johns Hopkins Aramco Healthcare, Dhahran, Saudi Arabia
| | - T Vivas-Buitrago
- Johns Hopkins University, Baltimore, MD, USA.,Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA.,Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - D Rigamonti
- Johns Hopkins University, Baltimore, MD, USA.,Johns Hopkins Aramco Healthcare, Dhahran, Saudi Arabia.,Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA.,Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.,Johns Hopkins Hopkins Aramco Healthcare, Dhahran, Saudi Arabia
| | - A Sattar
- Johns Hopkins Aramco Healthcare, Ras Tanura, Saudi Arabia.,Primary Care, Johns Hopkins Aramco Healthcare, Ras Tanura, Saudi Arabia
| | - O Omoush
- Johns Hopkins Aramco Healthcare, Ras Tanura, Saudi Arabia.,Primary Care, Johns Hopkins Aramco Healthcare, Ras Tanura, Saudi Arabia
| | - M Hammad
- Johns Hopkins Aramco Healthcare, Ras Tanura, Saudi Arabia
| | - M Dawood
- Johns Hopkins Aramco Healthcare, Ras Tanura, Saudi Arabia
| | - M Maghaslah
- Johns Hopkins Aramco Healthcare, Ras Tanura, Saudi Arabia
| | - T Belcher
- Johns Hopkins Aramco Healthcare, Ras Tanura, Saudi Arabia
| | - K Carson
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA.,Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - J Hoffberger
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA
| | - I Jusué Torres
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA.,Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - S Foley
- Department of Neurosurgery, Rhode Island Hospital, Providence, RI, USA
| | - S Yasar
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA
| | - Q A Thai
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA
| | - J Wemmer
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA
| | - P Klinge
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA
| | - L Al-Mutawa
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA
| | - H Al-Ghamdi
- Department of Neurosurgery, Rhode Island Hospital, Providence, RI, USA
| | - K A Carson
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - M Asgari
- The Interface Group, Institute of PhysiologyUniversity of Zurich, Zurich, Switzerland
| | - D de Zélicourt
- The Interface Group, Institute of PhysiologyUniversity of Zurich, Zurich, Switzerland
| | - V Kurtcuoglu
- The Interface Group, Institute of PhysiologyUniversity of Zurich, Zurich, Switzerland.,Institute of Physiology, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich and the Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - S Garnotel
- BioFlowImage Laboratory, University of Picardie Jules Verne, Amiens, France.,Reims Mathematics Laboratory, University of Reims Champagne-Ardenne, Reims, France.,Image Processing Laboratory, University Hospital of Amiens-Picardie, Amiens, France.,BioFlowImage Laboratory, Department of Medical Image Processing, University Hospital of Picardie Jules Verne, Amiens, France
| | - S Salmon
- Reims Mathematics Laboratory, University of Reims Champagne-Ardenne, Reims, France
| | - O Balédent
- BioFlowImage Laboratory, University of Picardie Jules Verne, Amiens, France.,Image Processing Laboratory, University Hospital of Amiens-Picardie, Amiens, France.,BioFlowImage Laboratory, Department of Medical Image Processing, University Hospital of Picardie Jules Verne, Amiens, France
| | - A Lokossou
- BioFlowImage Laboratory, Department of Medical Image Processing, University Hospital of Picardie Jules Verne, Amiens, France
| | - G Page
- BioFlowImage Laboratory, Department of Medical Image Processing, University Hospital of Picardie Jules Verne, Amiens, France
| | - L Balardy
- Department of Geriatric, University Hospital of Toulouse, Toulouse, France.,Departments of Geriatric, University Hospital of Toulouse, Toulouse, France.,Department of Geriatry, University Hospital Toulouse, Toulouse, France
| | - Z Czosnyka
- Neurosciences department, University of Cambridge, Cambridge, UK.,Brain Physics Lab, Academic Neurosurgery, University of Cambridge, Cambridge, UK
| | - P Payoux
- Department of Nuclear Medicine, University Hospital of Toulouse, Toulouse, France.,Department of Nuclear Medicine, University Hospital Toulouse, Toulouse, France.,INSER TONIC 1014, Toulouse Neuroimaging Center, Toulouse, France
| | - E A Schmidt
- UMR 1214-INSERM/UPS-TONIC Toulouse Neuro-Imaging Center, Toulouse, France.,Department of Neurosurgery, University Hospital of Toulouse, Toulouse, France.,Department of Neurosurgery, University Hospital Toulouse, Toulouse, France
| | - M Zitoun
- BioFlowImage, University Hospital of Picardie Jules Verne, Amiens, France
| | - M A Sevestre
- BioFlowImage, University Hospital of Picardie Jules Verne, Amiens, France
| | - N Alperin
- University of Miami Health System, Miami, FL, USA
| | - I Baudracco
- Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, UK
| | - C Craven
- Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, UK
| | - S Matloob
- Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, UK
| | - S Thompson
- Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, UK
| | - P Haylock Vize
- Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, UK
| | - L Thorne
- Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, UK
| | - L D Watkins
- Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, UK.,The National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - A K Toma
- Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, UK.,The National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Karl Bechter
- Department Psychiatry II/Bezirkskliniken, Ulm University, Günzburg, Germany
| | - A C Pong
- Neuroscience Research Australia, Randwick, Australia.,School of Medical Sciences, University of New South Wales, Kensington, Australia
| | - L Jugé
- Neuroscience Research Australia, Randwick, Australia.,School of Medical Sciences, University of New South Wales, Kensington, Australia
| | - L E Bilston
- Neuroscience Research Australia, Randwick, Australia.,Prince of Wales Clinical School, University of New South Wales, Kensington, Australia
| | - S Cheng
- Neuroscience Research Australia, Randwick, Australia.,Department of Engineering, Faculty of Science and Engineering, Macquarie University, Sydney, Australia
| | - W Bradley
- Department of Radiology, University of California San Diego Health System, San Diego, CA, USA
| | - F Hakim
- Department of Surgery, Section of Neurosurgery, Fundación Santa Fe de Bogotá, Bogotá, Colombia.,Neurosurgery Department, Hospital Universitario, Fundación Santafe de Bogota, Bogota, Colombia
| | - J F Ramón
- Department of Surgery, Section of Neurosurgery, Fundación Santa Fe de Bogotá, Bogotá, Colombia.,Grupo de Hidrocefalia con Presión Normal, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia.,Neurosurgery Department, Hospital Universitario, Fundación Santafe de Bogota, Bogota, Colombia
| | - M F Cárdenas
- Department of Surgery, Section of Neurosurgery, Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - J S Davidson
- Department of Surgery, Section of Neurosurgery, Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - C García
- Department of Surgery, Section of Neurosurgery, Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - D González
- Department of Surgery, Section of Neurosurgery, Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - S Bermúdez
- Department of Diagnostic Imaging, Section of Neuroradiology, Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - N Useche
- Department of Diagnostic Imaging, Section of Neuroradiology, Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - J A Mejía
- Grupo de Hidrocefalia con Presión Normal, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - P Mayorga
- Grupo de Hidrocefalia con Presión Normal, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - F Cruz
- Grupo de Hidrocefalia con Presión Normal, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - C Martinez
- Grupo de Hidrocefalia con Presión Normal, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - M C Matiz
- Grupo de Hidrocefalia con Presión Normal, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - M Vallejo
- Grupo de Hidrocefalia con Presión Normal, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - K Ghotme
- Grupo de Hidrocefalia con Presión Normal, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - H A Soto
- Grupo de Hidrocefalia con Presión Normal, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - D Riveros
- Grupo de Hidrocefalia con Presión Normal, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - A Buitrago
- Grupo de Hidrocefalia con Presión Normal, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - M Mora
- Grupo de Hidrocefalia con Presión Normal, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - L Murcia
- Grupo de Hidrocefalia con Presión Normal, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - S Bermudez
- Grupo de Hidrocefalia con Presión Normal, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - D Cohen
- Grupo de Hidrocefalia con Presión Normal, Hospital Universitario Fundación Santa Fe de Bogotá, Bogotá, Colombia
| | - D Dasgupta
- Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, UK
| | - C Curtis
- Department of Microbiology, University College London Hospital NHS Foundation Trust, London, UK
| | - L Domínguez
- Neurosurgery Department, Cartagena University, Cartagena de Indias, Colombia
| | - A J Remolina
- Neurosurgery Department, Cartagena University, Cartagena de Indias, Colombia
| | - M A Grijalba
- Neurosurgery Department, Cartagena University, Cartagena de Indias, Colombia
| | - K J Whitehouse
- Department of Paediatric Neurosurgery, Bristol Royal Hospital for Children, Bristol, UK
| | - R J Edwards
- Department of Paediatric Neurosurgery, Bristol Royal Hospital for Children, Bristol, UK
| | - A Eleftheriou
- Department of Neurology, University Hospital, Linköping, Sweden
| | - F Lundin
- Division of Neuroscience, Department of Clinical and Experimental Medicine (IKE), Linköping University, Linköping, Sweden
| | - K N Fountas
- Department of Neurosurgery, School of Medicine, University of Thessaly, Larisa, Greece
| | - E Z Kapsalaki
- Department of Diagnostic Radiology, School of Medicine, University of Thessaly, Larisa, Greece
| | - H F Smisson
- Department of Neurosurgery, Georgia Neurosurgical Institute, Macon, GA, USA
| | - J S Robinson
- Department of Neurosurgery, Georgia Neurosurgical Institute, Macon, GA, USA
| | - M J Fritsch
- Klinik für Neurochirurgie, Dietrich-Bonhoeffer-Klinikum, Neubrandenburg, Germany
| | - W Arouk
- Klinik für Neurochirurgie, Dietrich-Bonhoeffer-Klinikum, Neubrandenburg, Germany
| | - M Garzon
- Great Ormond Street Hospital, London, UK
| | - M Kang
- Great Ormond Street Hospital, London, UK
| | - K Sandhu
- Great Ormond Street Hospital, London, UK
| | | | - K Aquilina
- Great Ormond Street Hospital, London, UK
| | - G James
- Great Ormond Street Hospital, London, UK
| | - D Thompson
- Great Ormond Street Hospital, London, UK
| | - M Gehlen
- Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland.,Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - M Schmid Daners
- Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - A Eklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | - J Malm
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - D Gomez
- Neurosurgery Department, Hospital Universitario, Fundación Santafe de Bogota, Bogota, Colombia
| | - M Guerra
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, UACh, Valdivia, Chile
| | - M Jara
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, UACh, Valdivia, Chile
| | - M Flores
- Laboratorio de Polímeros, Facultad de Ciencias, UACh, Valdivia, Chile
| | - K Vío
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, UACh, Valdivia, Chile
| | - I Moreno
- Laboratorio de Polímeros, Facultad de Ciencias, UACh, Valdivia, Chile
| | - S Rodríguez
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, UACh, Valdivia, Chile
| | - E Ortega
- Instituto de Neurociencias Clínicas, Facultad de Medicina, UACh, Valdivia, Chile
| | - E M Rodríguez
- Instituto de Anatomía, Histología y Patología, Facultad de Medicina, UACh, Valdivia, Chile.,Instituto de Histologia y Patologia, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile
| | - J P McAllister
- Department of Neurosurgery, St. Louis Children's Hospital, St. Louis, MO, USA
| | - M M Guerra
- Instituto de Histologia y Patologia, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile
| | - D M Morales
- Department of Neurosurgery, St. Louis Children's Hospital, St. Louis, MO, USA
| | - D Sival
- Department of Pediatrics Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - A Jimenez
- Departamento de Biología Celular, Genética y Fisiología Facultad de Ciencias, Universidad de Malaga, Malaga, Spain
| | - D D Limbrick
- Department of Neurosurgery, St. Louis Children's Hospital, St. Louis, MO, USA.,Department of Pediatrics, St. Louis Children's Hospital, St. Louis, MO, USA
| | - M Ishikawa
- Rakuwa Villa Ilios, Kyoto, Japan.,Normal Pressure Hydrocephalus Center, Otowa Hospital, Kyoto, Japan
| | - S Yamada
- Normal Pressure Hydrocephalus Center, Otowa Hospital, Kyoto, Japan.,Department of Neurosurgery, Otowa Hospital, Kyoto, Japan
| | - K Yamamoto
- Department of Neurosurgery, Otowa Hospital, Kyoto, Japan
| | - A Junkkari
- Neurosurgery of NeuroCenter, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland.,Neurosurgery of NeuroCenter, Kuopio University Hospital, Kuopio, Finland
| | - A Häyrinen
- Neurosurgery of NeuroCenter, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland
| | - T Rauramaa
- Department of Pathology, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland.,Department of Pathology, Kuopio University Hospital, Kuopio, Finland.,Institute of Clinical Medicine-Pathology, University of Eastern Finland, Kuopio, Finland
| | - H Sintonen
- Department of Public Health, University of Helsinki, Helsinki, Finland
| | - O Nerg
- Neurology of NeuroCenter, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland.,Neurology of NeuroCenter, Kuopio University Hospital, Kuopio, Finland.,Institute of Clinical Medicine-Neurology, University of Eastern Finland, Kuopio, Finland
| | - A M Koivisto
- Neurology of NeuroCenter, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland.,Unit of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.,Neurology of NeuroCenter, Kuopio University Hospital, Kuopio, Finland.,Institute of Clinical Medicine-Neurology, University of Eastern Finland, Kuopio, Finland.,Department of Neurology, Kuopio University Hospital, Kuopio, Finland
| | - R P Roine
- University of Eastern Finland, Kuopio Finland and Helsinki and Uusimaa Hospital DistrictGroup Administration, Helsinki, Finland
| | - H Viinamäki
- Department of Psychiatry, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland
| | - H Soininen
- Department of Neurology, University of Eastern Finland, Kuopio, Finland.,Unit of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.,Neurology of NeuroCenter, Kuopio University Hospital, Kuopio, Finland.,Institute of Clinical Medicine-Neurology, University of Eastern Finland, Kuopio, Finland.,Department of Neurology, Kuopio University Hospital, Kuopio, Finland
| | - A Luikku
- Neurology of NeuroCenter, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | - J E Jääskeläinen
- Neurosurgery of NeuroCenter, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland.,Department of Neurosurgery, Kuopio University Hospital, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.,Neurosurgery of NeuroCenter, Kuopio University Hospital, Kuopio, Finland
| | - V Leinonen
- Neurosurgery of NeuroCenter, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland.,Department of Neurosurgery, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland.,Department of Neurosurgery, Kuopio University Hospital, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.,Neurosurgery of NeuroCenter, Kuopio University Hospital, Kuopio, Finland
| | - U Kehler
- Neurosurgical Department, Asklepios Klinik Hamburg Altona, Hamburg, Germany
| | - O Lilja-Lund
- Department of Pharmacology and Clinical Neuroscience, Unit of Neurology, Östersund, Umeå University, Umeå, Sweden
| | - K Kockum
- Department of Pharmacology and Clinical Neuroscience, Unit of Neurology, Östersund, Umeå University, Umeå, Sweden
| | - E M Larsson
- Department of Radiology, Uppsala University, Uppsala, Sweden
| | - K Riklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | - L Söderström
- Department of Pharmacology and Clinical Neuroscience, Unit of Neurology, Östersund, Umeå University, Umeå, Sweden
| | - P Hellström
- Hydrocephalus Research Unit, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - K Laurell
- Department of Pharmacology and Clinical Neuroscience, Unit of Neurology, Östersund, Umeå University, Umeå, Sweden
| | - M Kojoukhova
- Neurosurgery of NeuroCenter, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland.,Neurosurgery of NeuroCenter, Kuopio University Hospital, Kuopio, Finland.,Department of Radiology, Kuopio University Hospital, Kuopio, Finland
| | - A Sutela
- Department of Radiology, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland.,Department of Radiology, Kuopio University Hospital, Kuopio, Finland
| | - R Vanninen
- Department of Radiology, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland
| | - K I Vanha
- Neurosurgery of NeuroCenter, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland
| | - M Timonen
- Neurosurgery of NeuroCenter, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland
| | - J Rummukainen
- Department of Pathology, Kuopio University Hospital, Kuopio, Finland
| | - V Korhonen
- Department of Neurosurgery, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | - S Helisalmi
- Unit of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.,Institute of Clinical Medicine-Neurology, University of Eastern Finland, Kuopio, Finland.,Department of Neurology, Kuopio University Hospital, Kuopio, Finland
| | - E Solje
- Institute of Clinical Medicine-Neurology, University of Eastern Finland, Kuopio, Finland.,Department of Neurology, Kuopio University Hospital, Kuopio, Finland
| | - A M Remes
- Unit of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.,Neurology of NeuroCenter, Kuopio University Hospital, Kuopio, Finland.,Institute of Clinical Medicine-Neurology, University of Eastern Finland, Kuopio, Finland.,Department of Neurology, Kuopio University Hospital, Kuopio, Finland
| | - J Huovinen
- Department of Neurosurgery, Kuopio University Hospital, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
| | - J Paananen
- Unit of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.,Department of Neurology, Kuopio University Hospital, Kuopio, Finland.,Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - M Hiltunen
- Unit of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.,Neurology of NeuroCenter, Kuopio University Hospital, Kuopio, Finland.,Institute of Clinical Medicine-Neurology, University of Eastern Finland, Kuopio, Finland.,Department of Neurology, Kuopio University Hospital, Kuopio, Finland.,Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - M Kurki
- Department of Neurosurgery, Kuopio University Hospital, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.,Analytical and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA.,Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Stanley Center for Psychiatric Research, Broad Institute for Harvard and MIT, Cambridge, MA, USA
| | - B Martin
- Biological Engineering, University of Idaho, Moscow, ID, USA
| | - F Loth
- Mechanical Engineering, University of Akron, Akron, Ohio, USA
| | - M Luciano
- Neurosurgery, Johns Hopkins University, Baltimore, MA, USA.,Department of Neurosurgery, Johns Hopkins Hospital, Baltimore, MD, USA
| | - A J Luikku
- Institute of Clinical Medicine-Neurology, University of Eastern Finland, Kuopio, Finland.,Neurosurgery of NeuroCenter, Kuopio University Hospital, Kuopio, Finland
| | - A Hall
- Institute of Clinical Medicine-Neurology, University of Eastern Finland, Kuopio, Finland
| | - S K Herukka
- Neurology of NeuroCenter, Kuopio University Hospital, Kuopio, Finland.,Institute of Clinical Medicine-Neurology, University of Eastern Finland, Kuopio, Finland
| | - J Mattila
- VTT Technical Research Centre of Finland, Tampere, Finland.,Combinostics Ltd, Tampere, Finland
| | - J Lötjönen
- VTT Technical Research Centre of Finland, Tampere, Finland.,Combinostics Ltd, Tampere, Finland
| | - I Alafuzoff
- Institute of Clinical Medicine-Neurology, University of Eastern Finland, Kuopio, Finland.,Rudbeck Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.,Department of Pathology and Cytology, Uppsala University Hospital, Uppsala, Sweden
| | - I Jurjević
- Department of Neurosurgery, Graduate School of Medicine, Juntendo University, Tokyo, Japan.,Department of Pharmacology and Department of Neurology, University of Zagreb School of Medicine, Zagreb, Croatia
| | - M Miyajima
- Department of Neurosurgery, Graduate School of Medicine, Juntendo University, Tokyo, Japan.,Department of Neurosurgery, Juntendo University School of Medicine, Tokyo, Japan
| | - M Nakajima
- Department of Neurosurgery, Graduate School of Medicine, Juntendo University, Tokyo, Japan.,Department of Neurosurgery, Juntendo University School of Medicine, Tokyo, Japan
| | - H Murai
- Department of Neurosurgery, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - T Shin
- Department of Neurosurgery, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - D Kawaguchi
- Department of Neurosurgery, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - C Akiba
- Department of Neurosurgery, Juntendo University School of Medicine, Tokyo, Japan
| | - I Ogino
- Department of Neurosurgery, Juntendo University School of Medicine, Tokyo, Japan
| | - K Karagiozov
- Department of Neurosurgery, Juntendo University School of Medicine, Tokyo, Japan
| | - H Arai
- Department of Neurosurgery, Juntendo University School of Medicine, Tokyo, Japan
| | - R C Reis
- Group of Cerebral Hydrodynamics, Division of Functional Neurosurgery, Institute of Psychiatry, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - M J Teixeira
- Group of Cerebral Hydrodynamics, Division of Functional Neurosurgery, Institute of Psychiatry, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - C G Valêncio
- Group of Cerebral Hydrodynamics, Division of Functional Neurosurgery, Institute of Psychiatry, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - D da Vigua
- Group of Cerebral Hydrodynamics, Division of Functional Neurosurgery, Institute of Psychiatry, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - L Almeida-Lopes
- Núcleo de Pesquisa e Ensino de Fototerapia nas Ciências da Saúde (NUPEN), São Carlos, Brazil
| | - M W Mancini
- Núcleo de Pesquisa e Ensino de Fototerapia nas Ciências da Saúde (NUPEN), São Carlos, Brazil
| | - F C G Pinto
- Group of Cerebral Hydrodynamics, Division of Functional Neurosurgery, Institute of Psychiatry, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - R H Maykot
- Group of Cerebral Hydrodynamics, Division of Functional Neurosurgery, Institute of Psychiatry, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - G Calia
- Group of Cerebral Hydrodynamics, Division of Functional Neurosurgery, Institute of Psychiatry, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - J Tornai
- Group of Cerebral Hydrodynamics, Division of Functional Neurosurgery, Institute of Psychiatry, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - S S S Silvestre
- Group of Cerebral Hydrodynamics, Division of Functional Neurosurgery, Institute of Psychiatry, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - G Mendes
- Group of Cerebral Hydrodynamics, Division of Functional Neurosurgery, Institute of Psychiatry, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - V Sousa
- Group of Cerebral Hydrodynamics, Division of Functional Neurosurgery, Institute of Psychiatry, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - B Bezerra
- Group of Cerebral Hydrodynamics, Division of Functional Neurosurgery, Institute of Psychiatry, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - P Dutra
- Group of Cerebral Hydrodynamics, Division of Functional Neurosurgery, Institute of Psychiatry, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - P Modesto
- Group of Cerebral Hydrodynamics, Division of Functional Neurosurgery, Institute of Psychiatry, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - M F Oliveira
- Group of Cerebral Hydrodynamics, Division of Functional Neurosurgery, Institute of Psychiatry, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - C E Petitto
- Group of Cerebral Hydrodynamics, Division of Functional Neurosurgery, Institute of Psychiatry, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
| | - H Pulhorn
- Department of Neurosurgery, The Walton Centre, Liverpool, UK
| | - A Chandran
- Department of Neuroradiology, The Walton Centre, Liverpool, UK
| | - C McMahon
- Department of Neurosurgery, The Walton Centre, Liverpool, UK
| | - A S Rao
- The Johns Hopkins Hospital, Baltimore, MD, USA
| | - M Jumaly
- The Johns Hopkins Hospital, Baltimore, MD, USA
| | - D Solomon
- The Johns Hopkins Hospital, Baltimore, MD, USA.,Neurology, Johns Hopkins Hospital, Baltimore, MD, USA.,Department of Neurology, Johns Hopkins Bayview Medical Center, Baltimore, MD, USA
| | - A Moghekar
- The Johns Hopkins Hospital, Baltimore, MD, USA
| | - N Relkin
- Department of Neurology, Weill Cornell Medical College, New York, NY, USA
| | - M Hamilton
- Department of Neurosurgery, University of Calgary, Alberta, Canada
| | - H Katzen
- Department of Neurology, University of Miami, Miami, FL, USA
| | - M Williams
- Department of Neurosurgery, Washington University, Seattle, WA, USA
| | - T Bach
- Utah Data Collection Center (DCC), University of Utah, Salt Lake City, UT, USA
| | - S Zuspan
- Utah Data Collection Center (DCC), University of Utah, Salt Lake City, UT, USA
| | - R Holubkov
- Utah Data Collection Center (DCC), University of Utah, Salt Lake City, UT, USA
| | | | - G Clemens
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - P Sharkey
- School of Business, Loyola University Maryland, Baltimore, MD, USA
| | - A Sanyal
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - E Sankey
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA.,Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - K Rigamonti
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA
| | - S Naqvi
- Primary Care, Johns Hopkins Aramco Healthcare, Abqaiq, Saudi Arabia
| | - A Hung
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, USA.,Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - E Schmidt
- Department of Neurosurgery, University Hospital Toulouse, Toulouse, France
| | - F Ory-Magne
- Department of Neurology, University Hospital Toulouse, Toulouse, France.,INSER TONIC 1014, Toulouse Neuroimaging Center, Toulouse, France
| | - P Gantet
- Department of Nuclear Medicine, University Hospital Toulouse, Toulouse, France
| | - A Guenego
- Department of Neurosurgery, University Hospital Toulouse, Toulouse, France.,Department of Neuroradiology, University Hospital Toulouse, Toulouse, France
| | - A C Januel
- Department of Neuroradiology, University Hospital Toulouse, Toulouse, France
| | - P Tall
- Department of Neuroradiology, University Hospital Toulouse, Toulouse, France
| | - N Fabre
- Department of Neurology, University Hospital Toulouse, Toulouse, France
| | - L Mahieu
- Department of Ophtalmology, University Hospital Toulouse, Toulouse, France
| | - C Cognard
- Department of Neuroradiology, University Hospital Toulouse, Toulouse, France
| | - L Gray
- Department of Physiology, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | | | - K Takagi
- Normal Pressure Hydrocephalus Center, Kashiwa-Tanaka Hospital, Kashiwa, Japan
| | - K Onouchi
- Department of Neurology, Kashiwa-Tanaka Hospital, Kashiwa, Japan
| | - S D Thompson
- The National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - L D Thorne
- The National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - H M Tully
- Department of Neurology, University of Washington, Seattle, WA, USA
| | - T L Wenger
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - W A Kukull
- Department of Epidemiology, University of Washington, Seattle, WA, USA
| | - D Doherty
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - W B Dobyns
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - D Moran
- Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - S Vakili
- Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - M A Patel
- Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - B Elder
- Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - C R Goodwin
- Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - J A Crawford
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - M V Pletnikov
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - J Xu
- F. M. Kirby Research Center for Functional Brain Imaging at the Kennedy Krieger Institute, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - A Blitz
- Department of Radiology and Radiological Science, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - D A Herzka
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - H Guerrero-Cazares
- Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - A Quiñones-Hinojosa
- Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.,Department of Oncology, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - S Mori
- Department of Radiology-Magnetic Resonance Research, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - P Saavedra
- Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - H Treviño
- Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - K Maitani
- Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.,Tohoku University School of Medicine, Sendai, Japan
| | - W C Ziai
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - V Eslami
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - S Nekoovaght-Tak
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - R Dlugash
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - G Yenokyan
- Department of Biostatistics, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - N McBee
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - D F Hanley
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Asgari M, de Zélicourt DA, Kurtcuoglu V. Barrier dysfunction or drainage reduction: differentiating causes of CSF protein increase. Fluids Barriers CNS 2017; 14:14. [PMID: 28521764 PMCID: PMC5437537 DOI: 10.1186/s12987-017-0063-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [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: 02/24/2017] [Accepted: 05/09/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Cerebrospinal fluid (CSF) protein analysis is an important element in the diagnostic chain for various central nervous system (CNS) pathologies. Among multiple existing approaches to interpreting measured protein levels, the Reiber diagram is particularly robust with respect to physiologic inter-individual variability, as it uses multiple subject-specific anchoring values. Beyond reliable identification of abnormal protein levels, the Reiber diagram has the potential to elucidate their pathophysiologic origin. In particular, both reduction of CSF drainage from the cranio-spinal space as well as blood-CNS barrier dysfunction have been suggested ρas possible causes of increased concentration of blood-derived proteins. However, there is disagreement on which of the two is the true cause. METHODS We designed two computational models to investigate the mechanisms governing protein distribution in the spinal CSF. With a one-dimensional model, we evaluated the distribution of albumin and immunoglobulin G (IgG), accounting for protein transport rates across blood-CNS barriers, CSF dynamics (including both dispersion induced by CSF pulsations and advection by mean CSF flow) and CSF drainage. Dispersion coefficients were determined a priori by computing the axisymmetric three-dimensional CSF dynamics and solute transport in a representative segment of the spinal canal. RESULTS Our models reproduce the empirically determined hyperbolic relation between albumin and IgG quotients. They indicate that variation in CSF drainage would yield a linear rather than the expected hyperbolic profile. In contrast, modelled barrier dysfunction reproduces the experimentally observed relation. CONCLUSIONS High levels of albumin identified in the Reiber diagram are more likely to originate from a barrier dysfunction than from a reduction in CSF drainage. Our in silico experiments further support the hypothesis of decreasing spinal CSF drainage in rostro-caudal direction and emphasize the physiological importance of pulsation-driven dispersion for the transport of large molecules in the CSF.
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Affiliation(s)
- Mahdi Asgari
- The Interface Group, Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Diane A de Zélicourt
- The Interface Group, Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland. .,Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland. .,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
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Gehlen M, Kurtcuoglu V, Schmid Daners M. Is posture-related craniospinal compliance shift caused by jugular vein collapse? A theoretical analysis. Fluids Barriers CNS 2017; 14:5. [PMID: 28209177 PMCID: PMC5314698 DOI: 10.1186/s12987-017-0053-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [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: 10/09/2016] [Accepted: 02/06/2017] [Indexed: 11/10/2022] Open
Abstract
Background Postural changes are related to changes in cerebrospinal fluid (CSF) dynamics. While sitting up leads to a decrease in cranial CSF pressure, it also causes shifts in the craniospinal CSF volume and compliance distribution. We hypothesized that jugular vein collapse in upright posture is a major contributor to these shifts in CSF volume and compliance. Methods To test this hypothesis, we implemented a mathematical lumped-parameter model of the CSF system and the relevant parts of the cardiovascular system. In this model, the CSF and the venous system are each divided into a cranial and a spinal part. The pressures in these cranial and spinal portions differ by the posture-dependent hydrostatic pressure columns in the connecting vessels. Jugular collapse is represented by a reduction of the hydrostatic pressure difference between cranial and spinal veins. The CSF pressure–volume relationship is implemented as a function of the local CSF to venous pressure gradient. This implies that an increase in CSF volume leads to a simultaneous displacement of blood from adjacent veins. CSF pulsations driven by the cardiovascular system are introduced through a pulsating cranial arterial volume. Results In upright posture, the implemented CSF pressure–volume relationship shifts to lower cranial CSF pressures compared to the horizontal position, leading to a decrease in cranial CSF pressure when sitting up. Concurrently, the compliance of the spinal compartment decreases while the one of the cranial compartment increases. With this, in upright posture only 10% of the CSF system’s compliance is provided by the spinal compartment compared to 35% in horizontal posture. This reduction in spinal compliance is accompanied by a caudal shift of CSF volume. Also, the ability of the spinal CSF compartment to compensate for cerebral arterial volume pulsations reduces in upright posture, which in turn reduces the calculated craniospinal CSF flow pulsations. Conclusion The mathematical model enabled us to isolate the effect of jugular collapse and quantify the induced shifts of compliance and CSF volume. The good concordance of the modelled changes with clinically observed values indicates that jugular collapse can be considered a major contributor to CSF dynamics in upright posture.
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Affiliation(s)
- Manuel Gehlen
- Institute for Dynamic Systems and Control, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland. .,The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland.
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, and the Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Marianne Schmid Daners
- Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
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Taslimifar M, Oparija L, Verrey F, Kurtcuoglu V, Olgac U, Makrides V. Quantifying the relative contributions of different solute carriers to aggregate substrate transport. Sci Rep 2017; 7:40628. [PMID: 28091567 PMCID: PMC5238446 DOI: 10.1038/srep40628] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [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: 08/17/2016] [Accepted: 12/07/2016] [Indexed: 02/07/2023] Open
Abstract
Determining the contributions of different transporter species to overall cellular transport is fundamental for understanding the physiological regulation of solutes. We calculated the relative activities of Solute Carrier (SLC) transporters using the Michaelis-Menten equation and global fitting to estimate the normalized maximum transport rate for each transporter (Vmax). Data input were the normalized measured uptake of the essential neutral amino acid (AA) L-leucine (Leu) from concentration-dependence assays performed using Xenopus laevis oocytes. Our methodology was verified by calculating Leu and L-phenylalanine (Phe) data in the presence of competitive substrates and/or inhibitors. Among 9 potentially expressed endogenous X. laevis oocyte Leu transporter species, activities of only the uniporters SLC43A2/LAT4 (and/or SLC43A1/LAT3) and the sodium symporter SLC6A19/B0AT1 were required to account for total uptake. Furthermore, Leu and Phe uptake by heterologously expressed human SLC6A14/ATB0,+ and SLC43A2/LAT4 was accurately calculated. This versatile systems biology approach is useful for analyses where the kinetics of each active protein species can be represented by the Hill equation. Furthermore, its applicable even in the absence of protein expression data. It could potentially be applied, for example, to quantify drug transporter activities in target cells to improve specificity.
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Affiliation(s)
- Mehdi Taslimifar
- The Interface Group, Institute of Physiology, University of Zurich, Switzerland.,Epithelial Transport Group, Institute of Physiology, University of Zurich, Switzerland
| | - Lalita Oparija
- Epithelial Transport Group, Institute of Physiology, University of Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Switzerland
| | - Francois Verrey
- Epithelial Transport Group, Institute of Physiology, University of Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Switzerland.,National Center of Competence in Research, Kidney CH, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Switzerland.,National Center of Competence in Research, Kidney CH, Switzerland
| | - Ufuk Olgac
- The Interface Group, Institute of Physiology, University of Zurich, Switzerland.,National Center of Competence in Research, Kidney CH, Switzerland
| | - Victoria Makrides
- Epithelial Transport Group, Institute of Physiology, University of Zurich, Switzerland
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Abstract
The aim of this study was to evaluate whether possible preglomerular arterial-to-venous oxygen shunting is affected by the interaction between renal preglomerular carbon dioxide and oxygen transport. We hypothesized that a reverse (venous-to-arterial) shunting of carbon dioxide will increase partial pressure of carbon dioxide and decrease pH in the arteries and thereby lead to increased oxygen offloading and consequent oxygen shunting. To test this hypothesis, we employed a segment-wise three-dimensional computational model of coupled renal oxygen and carbon dioxide transport, wherein coupling is achieved by shifting the oxygen-hemoglobin dissociation curve in dependence of local changes in partial pressure of carbon dioxide and pH. The model suggests that primarily due to the high buffering capacity of blood, there is only marginally increased acidity in the preglomerular vasculature compared to systemic arterial blood caused by carbon dioxide shunting. Furthermore, effects of carbon dioxide transport do not promote but rather impair preglomerular oxygen shunting, as the increase in acidity is higher in the veins compared to that in the arteries. We conclude that while substantial arterial-to-venous oxygen shunting might take place in the postglomerular vasculature, the net amount of oxygen shunted at the preglomerular vasculature appears to be marginal.
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Affiliation(s)
- Ufuk Olgac
- The Interface Group, Institute of Physiology, University of ZurichZurich, Switzerland; National Center of Competence in Research, Kidney.CHZurich, Switzerland
| | - Vartan Kurtcuoglu
- The Interface Group, Institute of Physiology, University of ZurichZurich, Switzerland; National Center of Competence in Research, Kidney.CHZurich, Switzerland; Zurich Center for Integrative Human Physiology, University of ZurichZurich, Switzerland
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