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Cao J, Roth S, Zhang S, Kopczak A, Mami S, Asare Y, Georgakis MK, Messerer D, Horn A, Shemer R, Jacqmarcq C, Picot A, Green JP, Schlegl C, Li X, Tomas L, Dutsch A, Liman TG, Endres M, Wernsdorf SR, Fürle C, Carofiglio O, Zhu J, Brough D, Hornung V, Dichgans M, Vivien D, Schulz C, Dor Y, Tiedt S, Sager HB, Grosse GM, Liesz A. DNA-sensing inflammasomes cause recurrent atherosclerotic stroke. Nature 2024; 633:433-441. [PMID: 39112714 PMCID: PMC11390481 DOI: 10.1038/s41586-024-07803-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 07/09/2024] [Indexed: 08/17/2024]
Abstract
The risk of early recurrent events after stroke remains high despite currently established secondary prevention strategies1. Risk is particularly high in patients with atherosclerosis, with more than 10% of patients experiencing early recurrent events1,2. However, despite the enormous medical burden of this clinical phenomenon, the underlying mechanisms leading to increased vascular risk and recurrent stroke are largely unknown. Here, using a novel mouse model of stroke-induced recurrent ischaemia, we show that stroke leads to activation of the AIM2 inflammasome in vulnerable atherosclerotic plaques via an increase of circulating cell-free DNA. Enhanced plaque inflammation post-stroke results in plaque destabilization and atherothrombosis, finally leading to arterioarterial embolism and recurrent stroke within days after the index stroke. We confirm key steps of plaque destabilization also after experimental myocardial infarction and in carotid artery plaque samples from patients with acute stroke. Rapid neutrophil NETosis was identified as the main source of cell-free DNA after stroke and NET-DNA as the causative agent leading to AIM2 inflammasome activation. Neutralization of cell-free DNA by DNase treatment or inhibition of inflammasome activation reduced the rate of stroke recurrence after experimental stroke. Our findings present an explanation for the high recurrence rate after incident ischaemic events in patients with atherosclerosis. The detailed mechanisms uncovered here provide clinically uncharted therapeutic targets for which we show high efficacy to prevent recurrent events. Targeting DNA-mediated inflammasome activation after remote tissue injury represents a promising avenue for further clinical development in the prevention of early recurrent events.
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Affiliation(s)
- Jiayu Cao
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
| | - Stefan Roth
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany.
| | - Sijia Zhang
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
| | - Anna Kopczak
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Samira Mami
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
| | - Yaw Asare
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
| | - Marios K Georgakis
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
- Programme in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Denise Messerer
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany
| | - Amit Horn
- Department of Developmental Biology and Cancer Research, Hebrew University of Jerusalem, Faculty of Medicine, Jerusalem, Israel
| | - Ruth Shemer
- Department of Developmental Biology and Cancer Research, Hebrew University of Jerusalem, Faculty of Medicine, Jerusalem, Israel
| | - Charlene Jacqmarcq
- Normandie University, UNICAEN, INSERM UMR-S U1237, Physiopathology and Imaging of Neurological Disorders (PhIND), GIP Cyceron, Institute Blood and Brain @ Caen-Normandie (BB@C), Caen, France
| | - Audrey Picot
- Normandie University, UNICAEN, INSERM UMR-S U1237, Physiopathology and Imaging of Neurological Disorders (PhIND), GIP Cyceron, Institute Blood and Brain @ Caen-Normandie (BB@C), Caen, France
| | - Jack P Green
- Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance NHS Group, University of Manchester, Manchester, UK
| | - Christina Schlegl
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
| | - Xinghai Li
- Department of Cardiology, German Heart Centre Munich, Technical University of Munich, Munich, Germany
| | - Lukas Tomas
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany
| | - Alexander Dutsch
- Department of Cardiology, German Heart Centre Munich, Technical University of Munich, Munich, Germany
| | - Thomas G Liman
- Center for Stroke Research Berlin (CSB), Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Matthias Endres
- Center for Stroke Research Berlin (CSB), Charité-Universitätsmedizin Berlin, Berlin, Germany
- Department of Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Berlin, Berlin, Germany
| | - Saskia R Wernsdorf
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
| | - Christina Fürle
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
| | - Olga Carofiglio
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
| | - Jie Zhu
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
| | - David Brough
- Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance NHS Group, University of Manchester, Manchester, UK
| | - Veit Hornung
- Gene Center and Department of Biochemistry, LMU Munich, Munich, Germany
| | - Martin Dichgans
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Denis Vivien
- Normandie University, UNICAEN, INSERM UMR-S U1237, Physiopathology and Imaging of Neurological Disorders (PhIND), GIP Cyceron, Institute Blood and Brain @ Caen-Normandie (BB@C), Caen, France
- Research Clinical Department, Caen Normandie University Hospital, Caen, France
| | - Christian Schulz
- Medizinische Klinik und Poliklinik I, LMU University Hospital, LMU Munich, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
- Department of Immunopharmacology, Mannheim Institute for Innate Immunoscience (MI3), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Yuval Dor
- Department of Developmental Biology and Cancer Research, Hebrew University of Jerusalem, Faculty of Medicine, Jerusalem, Israel
| | - Steffen Tiedt
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
| | - Hendrik B Sager
- Department of Cardiology, German Heart Centre Munich, Technical University of Munich, Munich, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
| | - Gerrit M Grosse
- Department of Neurology, Hannover Medical School, Hannover, Germany
| | - Arthur Liesz
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany.
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
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2
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Bueno JM, Martínez-Ojeda RM, Pérez-Zabalza M, García-Mendívil L, Asensio MC, Ordovás L, Pueyo E. Analysis of age-related changes in the left ventricular myocardium with multiphoton microscopy. BIOMEDICAL OPTICS EXPRESS 2024; 15:3251-3264. [PMID: 38855691 PMCID: PMC11161339 DOI: 10.1364/boe.509227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 01/27/2024] [Accepted: 03/11/2024] [Indexed: 06/11/2024]
Abstract
Aging induces cardiac remodeling, resulting in an increase in the risk of suffering heart diseases, including heart failure. Collagen deposition increases with age and, together with sarcomeric changes in cardiomyocytes, may lead to ventricular stiffness. Multiphoton (MP) microscopy is a useful technique to visualize and detect variations in cardiac structures in a label free fashion. Here, we propose a method based on MP imaging (both two-photon excitation fluorescence (TPEF) and second harmonic generation (SHG) modalities) to explore and objectively quantify age-related structural differences in various components of cardiac tissues. Results in transmural porcine left ventricle (LV) sections reveal significant differences when comparing samples from young and old animals. Collagen and myosin SHG signals in old specimens are respectively 3.8x and >6-fold larger than in young ones. Differences in TPEF signals from cardiomyocyte were ∼3x. Moreover, the increased amount of collagen in old specimens results in a more organized pattern when compared to young LV tissues. Since changes in collagen and myosin are associated with cardiac dysfunction, the technique used herein might be a useful tool to accurately predict and measure changes associated with age-related myocardium fibrosis, tissue remodeling and sarcomeric alterations, with potential implications in preventing heart disease.
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Affiliation(s)
- Juan M. Bueno
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Campus de Espinardo (Ed. 34), 30100 Murcia, Spain
| | - Rosa M. Martínez-Ojeda
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Campus de Espinardo (Ed. 34), 30100 Murcia, Spain
| | - María Pérez-Zabalza
- BSICoS group, I3A, IIS Aragón, Universidad de Zaragoza, 50018 Zaragoza, Spain
- Centro Universitario de la Defensa (CUD), 50018 Zaragoza, Spain
| | | | - M. Carmen Asensio
- Laboratorio de Óptica, Instituto Universitario de Investigación en Óptica y Nanofísica, Universidad de Murcia, Campus de Espinardo (Ed. 34), 30100 Murcia, Spain
| | - Laura Ordovás
- BSICoS group, I3A, IIS Aragón, Universidad de Zaragoza, 50018 Zaragoza, Spain
- Fundación Agencia Aragonesa para la Investigación y el Desarrollo (ARAID), 50018 Zaragoza, Spain
| | - Esther Pueyo
- BSICoS group, I3A, IIS Aragón, Universidad de Zaragoza, 50018 Zaragoza, Spain
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina, 50018 Zaragoza, Spain
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3
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Hu YY, Hsu CW, Tseng YH, Lin CY, Chiang HC, Chiang AS, Chang ST, Chen SJ. Temporal focusing multiphoton microscopy with cross-modality multi-stage 3D U-Net for fast and clear bioimaging. BIOMEDICAL OPTICS EXPRESS 2023; 14:2478-2491. [PMID: 37342698 PMCID: PMC10278625 DOI: 10.1364/boe.484154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 04/17/2023] [Accepted: 04/24/2023] [Indexed: 06/23/2023]
Abstract
Temporal focusing multiphoton excitation microscopy (TFMPEM) enables fast widefield biotissue imaging with optical sectioning. However, under widefield illumination, the imaging performance is severely degraded by scattering effects, which induce signal crosstalk and a low signal-to-noise ratio in the detection process, particularly when imaging deep layers. Accordingly, the present study proposes a cross-modality learning-based neural network method for performing image registration and restoration. In the proposed method, the point-scanning multiphoton excitation microscopy images are registered to the TFMPEM images by an unsupervised U-Net model based on a global linear affine transformation process and local VoxelMorph registration network. A multi-stage 3D U-Net model with a cross-stage feature fusion mechanism and self-supervised attention module is then used to infer in-vitro fixed TFMPEM volumetric images. The experimental results obtained for in-vitro drosophila mushroom body (MB) images show that the proposed method improves the structure similarity index measures (SSIMs) of the TFMPEM images acquired with a 10-ms exposure time from 0.38 to 0.93 and 0.80 for shallow- and deep-layer images, respectively. A 3D U-Net model, pretrained on in-vitro images, is further trained using a small in-vivo MB image dataset. The transfer learning network improves the SSIMs of in-vivo drosophila MB images captured with a 1-ms exposure time to 0.97 and 0.94 for shallow and deep layers, respectively.
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Affiliation(s)
- Yvonne Yuling Hu
- Department of Photonics, National Cheng Kung University, Tainan 701, Taiwan
| | - Chia-Wei Hsu
- College of Photonics, National Yang Ming Chiao Tung University, Tainan 711, Taiwan
| | - Yu-Hao Tseng
- College of Photonics, National Yang Ming Chiao Tung University, Tainan 711, Taiwan
| | - Chun-Yu Lin
- College of Photonics, National Yang Ming Chiao Tung University, Tainan 711, Taiwan
| | - Hsueh-Cheng Chiang
- Department of Pharmacology, National Cheng Kung University, Tainan 701, Taiwan
| | - Ann-Shyn Chiang
- Brain Research Center, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Shin-Tsu Chang
- Department of Physical Medicine and Rehabilitation, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan
- Department of Physical Medicine and Rehabilitation, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan
| | - Shean-Jen Chen
- Department of Photonics, National Cheng Kung University, Tainan 701, Taiwan
- College of Photonics, National Yang Ming Chiao Tung University, Tainan 711, Taiwan
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4
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García-Mendívil L, Pérez-Zabalza M, Mountris K, Duwé S, Smisdom N, Pérez M, Luján L, Wolfs E, Driesen RB, Vallejo-Gil JM, Fresneda-Roldán PC, Fañanás-Mastral J, Vázquez-Sancho M, Matamala-Adell M, Sorribas-Berjón JF, Bellido-Morales JA, Mancebón-Sierra FJ, Vaca-Núñez AS, Ballester-Cuenca C, Oliván-Viguera A, Diez E, Ordovás L, Pueyo E. Analysis of age-related left ventricular collagen remodeling in living donors: Implications in arrhythmogenesis. iScience 2022; 25:103822. [PMID: 35198884 PMCID: PMC8850748 DOI: 10.1016/j.isci.2022.103822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 12/14/2021] [Accepted: 01/25/2022] [Indexed: 12/18/2022] Open
Abstract
Age-related fibrosis in the left ventricle (LV) has been mainly studied in animals by assessing collagen content. Using second-harmonic generation microscopy and image processing, we evaluated amount, aggregation and spatial distribution of LV collagen in young to old pigs, and middle-age and elder living donors. All collagen features increased when comparing adult and old pigs with young ones, but not when comparing adult with old pigs or middle-age with elder individuals. Remarkably, all collagen parameters strongly correlated with lipofuscin, a biological age marker, in humans. By building patient-specific models of human ventricular tissue electrophysiology, we confirmed that amount and organization of fibrosis modulated arrhythmia vulnerability, and that distribution should be accounted for arrhythmia risk assessment. In conclusion, we characterize the age-associated changes in LV collagen and its potential implications for ventricular arrhythmia development. Consistency between pig and human results substantiate the pig as a relevant model of age-related LV collagen dynamics. Collagen remodeling traits change from youth to adulthood, not from midlife onwards In humans, collagen remodeling traits relate with the biological age-pigment lipofuscin Beyond collagen amount, its distribution also influences ventricular arrhythmogenesis Consistent age-related remodeling was observed amid healthy farm pigs and living donors
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Affiliation(s)
- Laura García-Mendívil
- Biomedical Signal Interpretation and Computational Simulation Group (BSICoS), Aragón Institute of Engineering Research, University of Zaragoza, Zaragoza 50018, Spain.,BSICoS, IIS Aragón, Zaragoza 50018, Spain
| | - María Pérez-Zabalza
- Biomedical Signal Interpretation and Computational Simulation Group (BSICoS), Aragón Institute of Engineering Research, University of Zaragoza, Zaragoza 50018, Spain.,BSICoS, IIS Aragón, Zaragoza 50018, Spain
| | - Konstantinos Mountris
- Biomedical Signal Interpretation and Computational Simulation Group (BSICoS), Aragón Institute of Engineering Research, University of Zaragoza, Zaragoza 50018, Spain.,BSICoS, IIS Aragón, Zaragoza 50018, Spain
| | - Sam Duwé
- Advanced Optical Microscopy Centre, Biomedical Research Institute, Hasselt University, Diepenbeek 3500, Belgium
| | - Nick Smisdom
- Biomedical Research Institute, Hasselt University, Diepenbeek 3500, Belgium
| | - Marta Pérez
- Department of Anatomy, Embryology and Animal Genetics, University of Zaragoza, Zaragoza 50013, Spain.,Instituto Universitario de Investigación Mixto Agroalimentario de Aragón (IA2), University of Zaragoza, Zaragoza 50013, Spain
| | - Lluís Luján
- Instituto Universitario de Investigación Mixto Agroalimentario de Aragón (IA2), University of Zaragoza, Zaragoza 50013, Spain.,Department of Animal Pathology, University of Zaragoza, Zaragoza 50013, Spain
| | - Esther Wolfs
- Biomedical Research Institute, Hasselt University, Diepenbeek 3500, Belgium
| | - Ronald B Driesen
- Biomedical Research Institute, Hasselt University, Diepenbeek 3500, Belgium
| | - José María Vallejo-Gil
- Department of Cardiovascular Surgery, University Hospital Miguel Servet, Zaragoza 50009, Spain
| | | | - Javier Fañanás-Mastral
- Department of Cardiovascular Surgery, University Hospital Miguel Servet, Zaragoza 50009, Spain
| | - Manuel Vázquez-Sancho
- Department of Cardiovascular Surgery, University Hospital Miguel Servet, Zaragoza 50009, Spain
| | - Marta Matamala-Adell
- Department of Cardiovascular Surgery, University Hospital Miguel Servet, Zaragoza 50009, Spain
| | | | | | | | | | - Carlos Ballester-Cuenca
- Department of Cardiovascular Surgery, University Hospital Miguel Servet, Zaragoza 50009, Spain
| | - Aida Oliván-Viguera
- Biomedical Signal Interpretation and Computational Simulation Group (BSICoS), Aragón Institute of Engineering Research, University of Zaragoza, Zaragoza 50018, Spain.,BSICoS, IIS Aragón, Zaragoza 50018, Spain.,Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Zaragoza 50018, Spain
| | - Emiliano Diez
- Institute of Experimental Medicine and Biology of Cuyo (IMBECU), CONICET, Mendoza 5500, Argentina
| | - Laura Ordovás
- Biomedical Signal Interpretation and Computational Simulation Group (BSICoS), Aragón Institute of Engineering Research, University of Zaragoza, Zaragoza 50018, Spain.,BSICoS, IIS Aragón, Zaragoza 50018, Spain.,ARAID Foundation, Zaragoza 50018, Spain
| | - Esther Pueyo
- Biomedical Signal Interpretation and Computational Simulation Group (BSICoS), Aragón Institute of Engineering Research, University of Zaragoza, Zaragoza 50018, Spain.,BSICoS, IIS Aragón, Zaragoza 50018, Spain.,Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Zaragoza 50018, Spain
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5
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Oida D, Tomita K, Oikawa K, Wang TA, Makita S, Tsai MT, Yasuno Y. Computational multi-directional optical coherence tomography for visualizing the microstructural directionality of the tissue. BIOMEDICAL OPTICS EXPRESS 2021; 12:3851-3864. [PMID: 34457384 PMCID: PMC8367225 DOI: 10.1364/boe.426125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 05/20/2021] [Accepted: 05/23/2021] [Indexed: 06/13/2023]
Abstract
We demonstrate computational multi-directional optical coherence tomography (OCT) to assess the directional property of tissue microstructure. This method is the combination of phase-sensitive volumetric OCT imaging and post-signal processing. The latter comprises of two steps. The first step is an intensity-directional analysis, which determines the dominant en face fiber orientations. The second step is the phase-directional imaging, which reveals the sub-resolution depth-orientation of the microstructure. The feasibility of the method was tested by assessing muscle and tendon samples. Stripe patterns with several sizes were visualized in the phase-directional images. In order to interpret these images, the muscle and tendon structures were numerically modeled, and the phase-directional images were generated from the numerical model. The similarity of the experimental and numerical results suggested that the stripe patterns correspond to the muscle fiber bundle and its crimping.
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Affiliation(s)
- Daisuke Oida
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
| | - Kiriko Tomita
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
| | - Kensuke Oikawa
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
| | - Tai-Ang Wang
- Institute of Photonic System, College of Photonics, National Chiao-Tung University, Tainan City 71150, Taiwan
| | - Shuichi Makita
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
| | - Meng-Tsan Tsai
- Department of Electrical Engineering, Chang Gung University, Taoyuan 33302, Taiwan
- Department of Neurosurgery, Chang Gung Memorial Hospital, Linkou, Taoyuan 33305, Taiwan
| | - Yoshiaki Yasuno
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
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6
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Chang CY, Lin CY, Hu YY, Tsai SF, Hsu FC, Chen SJ. Temporal focusing multiphoton microscopy with optimized parallel multiline scanning for fast biotissue imaging. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-200171RR. [PMID: 33386708 PMCID: PMC7778456 DOI: 10.1117/1.jbo.26.1.016501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
SIGNIFICANCE Line scanning-based temporal focusing multiphoton microscopy (TFMPM) has superior axial excitation confinement (AEC) compared to conventional widefield TFMPM, but the frame rate is limited due to the limitation of the single line-to-line scanning mechanism. The development of the multiline scanning-based TFMPM requires only eight multiline patterns for full-field uniform multiphoton excitation and it still maintains superior AEC. AIM The optimized parallel multiline scanning TFMPM is developed, and the performance is verified with theoretical simulation. The system provides a sharp AEC equivalent to the line scanning-based TFMPM, but fewer scans are required. APPROACH A digital micromirror device is integrated in the TFMPM system and generates the multiline pattern for excitation. Based on the result of single-line pattern with sharp AEC, we can further model the multiline pattern to find the best structure that has the highest duty cycle together with the best AEC performance. RESULTS The AEC is experimentally improved to 1.7 μm from the 3.5 μm of conventional TFMPM. The adopted multiline pattern is akin to a pulse-width-modulation pattern with a spatial period of four times the diffraction-limited line width. In other words, ideally only four π / 2 spatial phase-shift scans are required to form a full two-dimensional image with superior AEC instead of image-size-dependent line-to-line scanning. CONCLUSIONS We have demonstrated the developed parallel multiline scanning-based TFMPM has the multiline pattern for sharp AEC and the least scans required for full-field uniform excitation. In the experimental results, the temporal focusing-based multiphoton images of disordered biotissue of mouse skin with improved axial resolution due to the near-theoretical limit AEC are shown to clearly reduce background scattering.
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Affiliation(s)
- Chia-Yuan Chang
- National Cheng Kung University, Department of Mechanical Engineering, Tainan, Taiwan
| | - Chun-Yun Lin
- National Chiao Tung University, College of Photonics, Tainan, Taiwan
| | - Yvonne Y. Hu
- National Cheng Kung University, Department of Photonics, Tainan, Taiwan
| | - Sheng-Feng Tsai
- National Cheng Kung University, Department of Cell Biology and Anatomy, Tainan, Taiwan
| | - Feng-Chun Hsu
- National Chiao Tung University, College of Photonics, Tainan, Taiwan
| | - Shean-Jen Chen
- National Chiao Tung University, College of Photonics, Tainan, Taiwan
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7
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Jett SV, Hudson LT, Baumwart R, Bohnstedt BN, Mir A, Burkhart HM, Holzapfel GA, Wu Y, Lee CH. Integration of polarized spatial frequency domain imaging (pSFDI) with a biaxial mechanical testing system for quantification of load-dependent collagen architecture in soft collagenous tissues. Acta Biomater 2020; 102:149-168. [PMID: 31734412 PMCID: PMC8101699 DOI: 10.1016/j.actbio.2019.11.028] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 11/11/2019] [Accepted: 11/12/2019] [Indexed: 12/30/2022]
Abstract
Collagen fiber networks provide the structural strength of tissues, such as tendons, skin and arteries. Quantifying the fiber architecture in response to mechanical loads is essential towards a better understanding of the tissue-level mechanical behaviors, especially in assessing disease-driven functional changes. To enable novel investigations into these load-dependent fiber structures, a polarized spatial frequency domain imaging (pSFDI) device was developed and, for the first time, integrated with a biaxial mechanical testing system. The integrated instrument is capable of a wide-field quantification of the fiber orientation and the degree of optical anisotropy (DOA), representing the local degree of fiber alignment. The opto-mechanical instrument''s performance was assessed through uniaxial loading on tendon tissues with known collagen fiber microstructures. Our results revealed that the bulk fiber orientation angle of the tendon tissue changed minimally with loading (median ± 0.5*IQR of 52.7° ± 3.3° and 51.9° ± 3.3° under 0 and 3% longitudinal strains, respectively), whereas on a micro-scale, the fibers became better aligned with the direction of loading: the DOA (mean ± SD) increased from 0.149 ± 0.032 to 0.198 ± 0.056 under 0 and 3% longitudinal strains, respectively, p < 0.001. The integrated instrument was further applied to study two representative mitral valve anterior leaflet (MVAL) tissues subjected to various biaxial loads. The fiber orientations within these representative MVAL tissue specimens demonstrated noticeable heterogeneity, with the local fiber orientations dependent upon the sample, the spatial and transmural locations, and the applied loading. Our results also showed that fibers were generally better aligned under equibiaxial (DOA = 0.089 ± 0.036) and circumferentially-dominant loading (DOA = 0.086 ± 0.037) than under the radially-dominant loading (DOA = 0.077 ± 0.034), indicating circumferential predisposition. These novel findings exemplify a deeper understanding of the load-dependent collagen fiber microstructures obtained through the use of the integrated opto-mechanical instrument. STATEMENT OF SIGNIFICANCE: In this study, a novel quantitative opto-mechanical system was developed by combining a polarized Spatial Frequency Domain Imaging (pSFDI) device with a biaxial mechanical tester. The integrated system was used to quantify the load-dependent collagen fiber microstructures in representative tendon and mitral valve anterior leaflet (MVAL) tissues. Our results revealed that MVAL's fiber architectures exhibited load-dependent spatial and transmural heterogeneities, suggesting further microstructural complexity than previously reported in heart valve tissues. These novel findings were possible through the system's ability to, for the first time, capture the load-dependent collagen architecture in the mitral valve anterior leaflet tissue over a wide field of view (e.g., 10 × 10 mm for the MVAL tissue specimens). Such capabilities afford unique future opportunities to improve patient outcomes through concurrent mechanical and microstructural assessments of healthy and diseased tissues in conditions such as heart valve regurgitation and calcification.
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Affiliation(s)
- Samuel V Jett
- Biomechanics and Biomaterials Design Laboratory, School of Aerospace and Mechanical Engineering, Affiliated Faculty Member, Institute for Biomedical Engineering, Science, and Technology, The University of Oklahoma, 865 Asp Ave., Felgar Hall Rm. 219C, Norman, OK 73019-3609, United States
| | - Luke T Hudson
- Biomechanics and Biomaterials Design Laboratory, School of Aerospace and Mechanical Engineering, Affiliated Faculty Member, Institute for Biomedical Engineering, Science, and Technology, The University of Oklahoma, 865 Asp Ave., Felgar Hall Rm. 219C, Norman, OK 73019-3609, United States
| | - Ryan Baumwart
- Center for Veterinary Health Sciences, Oklahoma State University, 2065 W. Farm Rd., Stillwater, OK 74078, United States
| | - Bradley N Bohnstedt
- Department of Neurosurgery, The University of Oklahoma Health Sciences Center, 1000 N Lincoln Blvd #400, Oklahoma City, OK 73104, United States
| | - Arshid Mir
- Division of Pediatric Cardiology, Department of Pediatrics, The University of Oklahoma Health Sciences Center, 1200 Children's Ave., Suite 2F, Oklahoma City, OK 73104, United States
| | - Harold M Burkhart
- Division of Cardiothoracic Surgery, Department of Surgery, The University of Oklahoma Health Sciences Center, 800 Stanton L. Young Blvd. Suite 9000, Oklahoma City, OK 73104, United States
| | - Gerhard A Holzapfel
- Institute of Biomechanics, Graz University of Technology, Stremayrgasse 16/2 8010 Graz, Austria; Department of Structural Engineering, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
| | - Yi Wu
- Biomechanics and Biomaterials Design Laboratory, School of Aerospace and Mechanical Engineering, Affiliated Faculty Member, Institute for Biomedical Engineering, Science, and Technology, The University of Oklahoma, 865 Asp Ave., Felgar Hall Rm. 219C, Norman, OK 73019-3609, United States
| | - Chung-Hao Lee
- Biomechanics and Biomaterials Design Laboratory, School of Aerospace and Mechanical Engineering, Affiliated Faculty Member, Institute for Biomedical Engineering, Science, and Technology, The University of Oklahoma, 865 Asp Ave., Felgar Hall Rm. 219C, Norman, OK 73019-3609, United States; Institute for Biomedical Engineering, Science and Technology, The University of Oklahoma, 202 West Boyd St., Norman, OK 73019, United States.
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8
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Hendon CP, Lye TH, Yao X, Gan Y, Marboe CC. Optical coherence tomography imaging of cardiac substrates. Quant Imaging Med Surg 2019; 9:882-904. [PMID: 31281782 PMCID: PMC6571187 DOI: 10.21037/qims.2019.05.09] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 05/06/2019] [Indexed: 01/02/2023]
Abstract
Cardiovascular disease is the leading cause of morbidity and mortality in the United States. Knowledge of a patient's heart structure will help to plan procedures, potentially identifying arrhythmia substrates, critical structures to avoid, detect transplant rejection, and reduce ambiguity when interpreting electrograms and functional measurements. Similarly, basic research of numerous cardiac diseases would greatly benefit from structural imaging at cellular scale. For both applications imaging on the scale of a myocyte is needed, which is approximately 100 µm × 10 µm. The use of optical coherence tomography (OCT) as a tool for characterizing cardiac tissue structure and function has been growing in the past two decades. We briefly review OCT principles and highlight important considerations when imaging cardiac muscle. In particular, image penetration, tissue birefringence, and light absorption by blood during in vivo imaging are important factors when imaging the heart with OCT. Within the article, we highlight applications of cardiac OCT imaging including imaging heart tissue structure in small animal models, quantification of myofiber organization, monitoring of radiofrequency ablation (RFA) lesion formation, structure-function analysis enabled by functional extensions of OCT and multimodal analysis and characterizing important substrates within the human heart. The review concludes with a summary and future outlook of OCT imaging the heart, which is promising with progress in optical catheter development, functional extensions of OCT, and real time image processing to enable dynamic imaging and real time tracking during therapeutic procedures.
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Affiliation(s)
| | | | | | - Yu Gan
- Columbia University, New York, NY, USA
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9
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Wu Z, Rademakers T, Kiessling F, Vogt M, Westein E, Weber C, Megens RT, van Zandvoort M. Multi-photon microscopy in cardiovascular research. Methods 2017; 130:79-89. [DOI: 10.1016/j.ymeth.2017.04.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 03/27/2017] [Accepted: 04/11/2017] [Indexed: 01/26/2023] Open
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10
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Goergen CJ, Chen HH, Sakadžić S, Srinivasan VJ, Sosnovik DE. Microstructural characterization of myocardial infarction with optical coherence tractography and two-photon microscopy. Physiol Rep 2017; 4:4/18/e12894. [PMID: 27650248 PMCID: PMC5037910 DOI: 10.14814/phy2.12894] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 07/07/2016] [Indexed: 11/24/2022] Open
Abstract
Myocardial infarction leads to complex changes in the fiber architecture of the heart. Here, we present a novel optical approach to characterize these changes in intact hearts in three dimensions. Optical coherence tomography (OCT) was used to derive a depth‐resolved field of orientation on which tractography was performed. Tractography of healthy myocardium revealed a smooth linear transition in fiber inclination or helix angle from the epicardium to endocardium. Conversely, in infarcted hearts, no coherent microstructure could be identified in the infarct with OCT. Additional characterization of the infarct was performed by the measurement of light attenuation and with two‐photon microscopy. Myofibers were imaged using autofluorescence and collagen fibers using second harmonic generation. This revealed the presence of two distinct microstructural patterns in areas of the infarct with high light attenuation. In the presence of residual myofibers, the surrounding collagen fibers were aligned in a coherent manner parallel to the myofibers. In the absence of residual myofibers, the collagen fibers were randomly oriented and lacked any microstructural coherence. The presence of residual myofibers thus exerts a profound effect on the microstructural properties of the infarct scar and consequently the risk of aneurysm formation and arrhythmias. Catheter‐based approaches to segment and image myocardial microstructure in humans are feasible and could play a valuable role in guiding the development of strategies to improve infarct healing.
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Affiliation(s)
- Craig J Goergen
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital Harvard Medical School, Charlestown, Massachusetts
| | - Howard H Chen
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital Harvard Medical School, Charlestown, Massachusetts Cardiovascular Research Center, Department of Medicine, Massachusetts General Hospital Harvard Medical School, Charlestown, Massachusetts
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital Harvard Medical School, Charlestown, Massachusetts
| | - Vivek J Srinivasan
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital Harvard Medical School, Charlestown, Massachusetts Department of Biomedical Engineering, University of California Davis, Davis, California
| | - David E Sosnovik
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital Harvard Medical School, Charlestown, Massachusetts Cardiovascular Research Center, Department of Medicine, Massachusetts General Hospital Harvard Medical School, Charlestown, Massachusetts
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11
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Guzzoni V, Marqueti RDC, Durigan JLQ, Faustino de Carvalho H, Lino RLB, Mekaro MS, Costa Santos TO, Mecawi AS, Rodrigues JA, Hord JM, Lawler JM, Davel AP, Selistre-de-Araújo HS. Reduced collagen accumulation and augmented MMP-2 activity in left ventricle of old rats submitted to high-intensity resistance training. J Appl Physiol (1985) 2017; 123:655-663. [PMID: 28684598 DOI: 10.1152/japplphysiol.01090.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 06/23/2017] [Accepted: 06/29/2017] [Indexed: 01/09/2023] Open
Abstract
Progressive fibrosis is a hallmark of the aging heart. Age-related fibrosis is modulated by endurance exercise training; however, little is known concerning the influence of resistance training (RT). Therefore we investigated the chronic effects of high-intensity RT on age-associated alterations of left ventricle (LV) structure, collagen content, matrix metalloproteinase-2 (MMP-2), and extracellular matrix-related gene expression, including transforming growth factor-β (TGF-β). Young adult (3 mo) and aged (21 mo) male Wistar rats were submitted to a RT protocol (ladder climbing with 65, 85, 95, and 100% load), three times a week for 12 wk. Forty-eight hours posttraining, arterial systolic and diastolic pressure, LV end-diastolic pressure (LVEDP) and dP/dt were recorded. LV morphology, collagen deposition, and gene expression of type I (COL-I) and type III (COL-III) collagen, MMP-2, tissue inhibitor of metalloproteinases-1 (TIMP-1), and TGF-β1 were analyzed by quantitative reverse transcriptase-PCR. MMP-2 content was assessed by zymography. Increased collagen deposition was observed in LV from aged rats. These parameters were modulated by RT and were associated with increased MMP-2 activity and decreased COL-I, TGF-β1, and TIMP-1 mRNA content. Despite the effect of RT on collagen accumulation, there was no improvement on LVEDP and maximal negative LV dP/dt of aged rats. Cardiomyocyte diameter was preserved in all experimental conditions. In conclusion, RT attenuated age-associated collagen accumulation, concomitant to the increase in MMP-2 activity and decreased expression of COL-I, TGF-β1, and TIMP-1 in LV, illustrating a cardioprotective effect of RT on ventricular structure and function.NEW & NOTEWORTHY We demonstrated the beneficial resistance-training effect against age-related left ventricle collagen accumulation in the left ventricle, which was associated with decreased type I collagen (COL-I), transforming growth factor-β1 (TGF-β1), and tissue inhibitor of metalloproteinases-1 (TIMP-1) gene expression and matrix metalloproteinase-2 (MMP-2) activity. Our findings suggest for the first time the potential effects of resistance training in modulating collagen accumulation and possibly fibrosis in the aging heart.
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Affiliation(s)
- Vinicius Guzzoni
- Department of Physiological Sciences, Federal University of São Carlos, São Carlos, Brazil;
| | | | | | | | | | - Marcelo S Mekaro
- Department of Physiological Sciences, Federal University of São Carlos, São Carlos, Brazil
| | | | - André Souza Mecawi
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil; and
| | - José Antunes Rodrigues
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil; and
| | - Jeffrey M Hord
- Department of Health & Kinesiology, Texas A&M University, College Station, Texas
| | - Jonh M Lawler
- Department of Health & Kinesiology, Texas A&M University, College Station, Texas
| | - Ana Paula Davel
- Institute of Biology, State University of Campinas, Campinas, Brazil
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12
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Dow XY, DeWalt EL, Sullivan SZ, Schmitt PD, Ulcickas JRW, Simpson GJ. Imaging the Nonlinear Susceptibility Tensor of Collagen by Nonlinear Optical Stokes Ellipsometry. Biophys J 2017; 111:1361-1374. [PMID: 27705760 DOI: 10.1016/j.bpj.2016.05.055] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 04/20/2016] [Accepted: 05/16/2016] [Indexed: 10/20/2022] Open
Abstract
Nonlinear optical Stokes ellipsometric (NOSE) microscopy was demonstrated for the analysis of collagen-rich biological tissues. NOSE is based on polarization-dependent second harmonic generation imaging. NOSE was used to access the molecular-level distribution of collagen fibril orientation relative to the local fiber axis at every position within the field of view. Fibril tilt-angle distribution was investigated by combining the NOSE measurements with ab initio calculations of the predicted molecular nonlinear optical response of a single collagen triple helix. The results were compared with results obtained previously by scanning electron microscopy, nuclear magnetic resonance imaging, and electron tomography. These results were enabled by first measuring the laboratory-frame Jones nonlinear susceptibility tensor, then extending to the local-frame tensor through pixel-by-pixel corrections based on local orientation.
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Affiliation(s)
- Ximeng Y Dow
- Department of Chemistry, Purdue University, West Lafayette, Indiana
| | - Emma L DeWalt
- Department of Chemistry, Purdue University, West Lafayette, Indiana
| | - Shane Z Sullivan
- Department of Chemistry, Purdue University, West Lafayette, Indiana
| | - Paul D Schmitt
- Department of Chemistry, Purdue University, West Lafayette, Indiana
| | | | - Garth J Simpson
- Department of Chemistry, Purdue University, West Lafayette, Indiana.
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13
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Dow XY, DeWalt EL, Newman JA, Dettmar CM, Simpson GJ. Unified Theory for Polarization Analysis in Second Harmonic and Sum Frequency Microscopy. Biophys J 2016; 111:1553-1568. [PMID: 27705777 PMCID: PMC5052445 DOI: 10.1016/j.bpj.2016.04.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 04/15/2016] [Accepted: 04/19/2016] [Indexed: 11/22/2022] Open
Abstract
A unified theoretical framework for the recovery of second-order nonlinear susceptibility tensors and sample orientations from polarization-dependent second harmonic generation and sum frequency generation microscopy was developed. Jones formalism was extended to nonlinear optics and was used to bridge the experimental observables and the local-frame tensor elements. Four commonly used experimental architectures were explicitly explored, including polarization rotation with no postsample optics, polarization-in polarization-out measurement, and polarization modulation with and without postsample optics. Polarization-dependent second harmonic generation measurement was performed on Z-cut quartz and the local-frame tensor elements were calculated. The recovered tensor elements agree with the expected values dictated by symmetry.
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14
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Yao X, Gan Y, Marboe CC, Hendon CP. Myocardial imaging using ultrahigh-resolution spectral domain optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:61006. [PMID: 27001162 PMCID: PMC4814547 DOI: 10.1117/1.jbo.21.6.061006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 02/29/2016] [Indexed: 05/17/2023]
Abstract
We present an ultrahigh-resolution spectral domain optical coherence tomography (OCT) system in 800 nm with a low-noise supercontinuum source (SC) optimized for myocardial imaging. The system was demonstrated to have an axial resolution of 2.72 μm with a large imaging depth of 1.78 mm and a 6-dB falloff range of 0.89 mm. The lateral resolution (5.52 μm) was compromised to enhance the image penetration required for myocardial imaging. The noise of the SC source was analyzed extensively and an imaging protocol was proposed for SC-based OCT imaging with appreciable contrast. Three-dimensional datasets were acquired ex vivo on the endocardium side of tissue specimens from different chambers of fresh human and swine hearts. With the increased resolution and contrast, features such as elastic fibers, Purkinje fibers, and collagen fiber bundles were observed. The correlation between the structural information revealed in the OCT images and tissue pathology was discussed as well.
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Affiliation(s)
- Xinwen Yao
- Columbia University, Department of Electrical Engineering, 500 West 120th Street, New York, New York 10027, United States
| | - Yu Gan
- Columbia University, Department of Electrical Engineering, 500 West 120th Street, New York, New York 10027, United States
| | - Charles C Marboe
- Columbia University Medical Center, Department of Pathology and Cell Biology, 630 West 168th Street, New York, New York 10032, United States
| | - Christine P Hendon
- Columbia University, Department of Electrical Engineering, 500 West 120th Street, New York, New York 10027, United States
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15
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Monaghan MG, Kroll S, Brucker SY, Schenke-Layland K. Enabling Multiphoton and Second Harmonic Generation Imaging in Paraffin-Embedded and Histologically Stained Sections. Tissue Eng Part C Methods 2016; 22:517-23. [PMID: 27018844 PMCID: PMC4922008 DOI: 10.1089/ten.tec.2016.0071] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Nonlinear microscopy, namely multiphoton imaging and second harmonic generation (SHG), is an established noninvasive technique useful for the imaging of extracellular matrix (ECM). Typically, measurements are performed in vivo on freshly excised tissues or biopsies. In this article, we describe the effect of rehydrating paraffin-embedded sections on multiphoton and SHG emission signals and the acquisition of nonlinear images from hematoxylin and eosin (H&E)-stained sections before and after a destaining protocol. Our results reveal that bringing tissue sections to a physiological state yields a significant improvement in nonlinear signals, particularly in SHG. Additionally, the destaining of sections previously processed with H&E staining significantly improves their SHG emission signals during imaging, thereby allowing sufficient analysis of collagen in these sections. These results are important for researchers and pathologists to obtain additional information from paraffin-embedded tissues and archived samples to perform retrospective analysis of the ECM or gain additional information from rare samples.
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Affiliation(s)
- Michael G Monaghan
- 1 Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University Tübingen , Tübingen, Germany
| | - Sebastian Kroll
- 1 Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University Tübingen , Tübingen, Germany
| | - Sara Y Brucker
- 1 Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University Tübingen , Tübingen, Germany
| | - Katja Schenke-Layland
- 1 Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University Tübingen , Tübingen, Germany .,2 Department of Cell and Tissue Engineering, Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB), Stuttgart, Germany .,3 Department of Medicine/Cardiology, Cardiovascular Research Laboratories, University of California , Los Angeles, California
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16
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Masè M, Cristoforetti A, Avogaro L, Tessarolo F, Piccoli F, Caola I, Pederzolli C, Graffigna A, Ravelli F. A spectral approach for the quantitative description of cardiac collagen network from nonlinear optical imaging. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:6257-60. [PMID: 26737722 DOI: 10.1109/embc.2015.7319822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The assessment of collagen structure in cardiac pathology, such as atrial fibrillation (AF), is essential for a complete understanding of the disease. This paper introduces a novel methodology for the quantitative description of collagen network properties, based on the combination of nonlinear optical microscopy with a spectral approach of image processing and analysis. Second-harmonic generation (SHG) microscopy was applied to atrial tissue samples from cardiac surgery patients, providing label-free, selective visualization of the collagen structure. The spectral analysis framework, based on 2D-FFT, was applied to the SHG images, yielding a multiparametric description of collagen fiber orientation (angle and anisotropy indexes) and texture scale (dominant wavelength and peak dispersion indexes). The proof-of-concept application of the methodology showed the capability of our approach to detect and quantify differences in the structural properties of the collagen network in AF versus sinus rhythm patients. These results suggest the potential of our approach in the assessment of collagen properties in cardiac pathologies related to a fibrotic structural component.
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17
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Hervas A, Ruiz-Sauri A, de Dios E, Forteza MJ, Minana G, Nunez J, Gomez C, Bonanad C, Perez-Sole N, Gavara J, Chorro FJ, Bodi V. Inhomogeneity of collagen organization within the fibrotic scar after myocardial infarction: results in a swine model and in human samples. J Anat 2015; 228:47-58. [PMID: 26510481 DOI: 10.1111/joa.12395] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2015] [Indexed: 11/30/2022] Open
Abstract
We aimed to characterize the organization of collagen within a fibrotic scar in swine and human samples from patients with chronic infarctions. Swine were subjected to occlusion of the left anterior descending artery followed by reperfusion 1 week (acute myocardial infarction group) or 1 month (chronic myocardial infarction group) after infarction. The organization of the collagen fibers (Fast Fourier Transform of samples after picrosirius staining; higher values indicate more disorganization) was studied in 100 swine and 95 human samples. No differences in collagen organization were found between the acute and chronic groups in the core area of the scar in the experimental model. In the chronic group, the endocardium [0.90 (0.84-0.94); median (interquartile range)], epicardium [0.84 (0.79-0.91)] and peripheral area [0.73 (0.63-0.83)] displayed a much more disorganized pattern than the core area of the fibrotic scar [0.56 (0.45-0.64)]. Similarly, in human samples, the collagen fibers were more disorganized in all of the outer areas than in the core of the fibrotic scar (P < 0.0001). Both in a highly controlled experimental model and in patient samples, collagen fibers exhibited an organized pattern in the core of the infarction, whereas the outer areas displayed a high level of inhomogeneity. This finding contributes pathophysiological information regarding the healing process and may lead to a clearer understanding of the genesis and invasive treatment of arrhythmias after acute myocardial infarction.
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Affiliation(s)
- Arantxa Hervas
- Cardiology Department, Hospital Clinico Universitario, INCLIVA, University of Valencia, Valencia, Spain
| | | | - Elena de Dios
- Cardiology Department, Hospital Clinico Universitario, INCLIVA, University of Valencia, Valencia, Spain
| | - Maria Jose Forteza
- Cardiology Department, Hospital Clinico Universitario, INCLIVA, University of Valencia, Valencia, Spain
| | - Gema Minana
- Cardiology Department, Hospital Clinico Universitario, INCLIVA, University of Valencia, Valencia, Spain
| | - Julio Nunez
- Cardiology Department, Hospital Clinico Universitario, INCLIVA, University of Valencia, Valencia, Spain
| | - Cristina Gomez
- Cardiology Department, Hospital Clinico Universitario, INCLIVA, University of Valencia, Valencia, Spain
| | - Clara Bonanad
- Cardiology Department, Hospital Clinico Universitario, INCLIVA, University of Valencia, Valencia, Spain
| | - Nerea Perez-Sole
- Cardiology Department, Hospital Clinico Universitario, INCLIVA, University of Valencia, Valencia, Spain
| | - Jose Gavara
- Cardiology Department, Hospital Clinico Universitario, INCLIVA, University of Valencia, Valencia, Spain
| | - Francisco Javier Chorro
- Cardiology Department, Hospital Clinico Universitario, INCLIVA, University of Valencia, Valencia, Spain
| | - Vicente Bodi
- Cardiology Department, Hospital Clinico Universitario, INCLIVA, University of Valencia, Valencia, Spain
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18
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Characterization of fibrillar collagens and extracellular matrix of glandular benign prostatic hyperplasia nodules. PLoS One 2014; 9:e109102. [PMID: 25275645 PMCID: PMC4183548 DOI: 10.1371/journal.pone.0109102] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 08/28/2014] [Indexed: 12/02/2022] Open
Abstract
Objective Recent studies have associated lower urinary tract symptoms (LUTS) in men with prostatic fibrosis, but a definitive link between collagen deposition and LUTS has yet to be demonstrated. The objective of this study was to evaluate ECM and collagen content within normal glandular prostate tissue and glandular BPH, and to evaluate the association of clinical parameters of LUTS with collagen content. Methods Fibrillar collagen and ECM content was assessed in normal prostate (48 patients) and glandular BPH nodules (24 patients) using Masson's trichrome stain and Picrosirius red stain. Second harmonic generation (SHG) imaging was used to evaluate collagen content. Additional BPH tissues (n = 47) were stained with Picrosirius red and the association between clinical parameters of BPH/LUTS and collagen content was assessed. Results ECM was similar in normal prostate and BPH (p = 0.44). Total collagen content between normal prostate and glandular BPH was similar (p = 0.27), but a significant increase in thicker collagen bundles was observed in BPH (p = 0.045). Using SHG imaging, collagen content in BPH (mean intensity = 62.52; SEM = 2.74) was significantly higher than in normal prostate (51.77±3.49; p = 0.02). Total collagen content was not associated with treatment with finasteride (p = 0.47) or α-blockers (p = 0.52), pre-TURP AUA symptom index (p = 0.90), prostate-specific antigen (p = 0.86), post-void residual (PVR; p = 0.32), prostate size (p = 0.21), or post-TURP PVR (p = 0.51). Collagen content was not associated with patient age in patients with BPH, however as men aged normal prostatic tissue had a decreased proportion of thick collagen bundles. Conclusions The proportion of larger bundles of collagen, but not total collagen, is increased in BPH nodules, suggesting that these large fibers may play a role in BPH/LUTS. Total collagen content is independent of clinical parameters of BPH and LUTS. If fibrosis and overall ECM deposition are associated with BPH/LUTS, this relationship likely exists in regions of the prostate other than glandular hyperplasia.
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19
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Lan SM, Wu YN, Wu PC, Sun CK, Shieh DB, Lin RM. Advances in noninvasive functional imaging of bone. Acad Radiol 2014; 21:281-301. [PMID: 24439341 DOI: 10.1016/j.acra.2013.11.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 11/20/2013] [Accepted: 11/26/2013] [Indexed: 02/03/2023]
Abstract
The demand for functional imaging in clinical medicine is comprehensive. Although the gold standard for the functional imaging of human bones in clinical settings is still radionuclide-based imaging modalities, nonionizing noninvasive imaging technology in small animals has greatly advanced in recent decades, especially the diffuse optical imaging to which Britton Chance made tremendous contributions. The evolution of imaging probes, instruments, and computation has facilitated exploration in the complicated biomedical research field by allowing longitudinal observation of molecular events in live cells and animals. These research-imaging tools are being used for clinical applications in various specialties, such as oncology, neuroscience, and dermatology. The Bone, a deeply located mineralized tissue, presents a challenge for noninvasive functional imaging in humans. Using nanoparticles (NP) with multiple favorable properties as bioimaging probes has provided orthopedics an opportunity to benefit from these noninvasive bone-imaging techniques. This review highlights the historical evolution of radionuclide-based imaging, computed tomography, positron emission tomography, and magnetic resonance imaging, diffuse optics-enabled in vivo technologies, vibrational spectroscopic imaging, and a greater potential for using NPs for biomedical imaging.
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20
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The arrhythmogenic effect of self-assembling nanopeptide hydrogel scaffolds on neonatal mouse cardiomyocytes. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2014; 10:1065-73. [PMID: 24491398 DOI: 10.1016/j.nano.2014.01.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 01/10/2014] [Accepted: 01/22/2014] [Indexed: 01/16/2023]
Abstract
UNLABELLED The chaotic spatial disarray due to extracellular matrix expansion disrupts cardiomyocytes interaction and causes arrhythmia. We hypothesized that disordered nanopeptide scaffolds can mimic the chaotic spatial disarray related to cardiac fibrosis and have arrhythmogenic effects on cardiomyocytes. Primary mouse cardiomyocytes were cultured in 2D traditional and 3D nanopeptide hydrogel scaffold systems. Cardiomyocytes in 3D scaffolds showed irregular spontaneous contractile activity as compared with 2D culture controls. Calcium fluorimetric imaging revealed that basal intracellular calcium level increased 1.42-fold in cardiomyocytes cultured in the 3D scaffold, in vitro. The mRNA levels of sarcoplasmic reticulum calcium transport ATPase, ryanodine 2 receptor and connexin 43 elevated 2.14-fold, 2.33-fold and 2.62-fold in 3D compared with 2D. Immunofluorescence imaging revealed lateralization of the distribution of connexin 43 in 3D group. These findings suggest that 3D hydrogel culture system provides a model for the development of cardiac dysrhythmia. These limitations should be considered during cardiac tissue engineering. FROM THE CLINICAL EDITOR This team of scientists has established a unique 3D hydrogel culture system as a model for the development of cardiac dysrhythmia.
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Martin TP, Norris G, McConnell G, Currie S. A novel approach for assessing cardiac fibrosis using label-free second harmonic generation. Int J Cardiovasc Imaging 2013; 29:1733-40. [PMID: 23921804 DOI: 10.1007/s10554-013-0270-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 07/28/2013] [Indexed: 01/06/2023]
Abstract
To determine whether second harmonic generation (SHG) can be used as a novel and improved label-free technique for detection of collagen deposition in the heart. To verify whether SHG will allow accurate quantification of altered collagen deposition in diseased hearts following hypertrophic remodelling. Minimally invasive transverse aortic banding (MTAB) of mouse hearts was used to generate a reproducible model of cardiac hypertrophy. Physiological and functional assessment of hypertrophic development was performed using echocardiography and post-mortem analysis of remodelled hearts. Cardiac fibroblasts were isolated from sham-operated and hypertrophied hearts and proliferation rates compared. Multi-photon laser scanning microscopy was used to capture both two-photon excited autofluorescence (TPEF) and SHG images simultaneously in two channels. TPEF images were subtracted from SHG images and the resulting signal intensities from ventricular tissue sections were calculated. Traditional picrosirius red staining was used to verify the suitability of the SHG application. MTAB surgery induced significant hypertrophic remodelling and increased cardiac fibroblast proliferation. A significant increase in the density of collagen fibres between hypertrophic and control tissues (p < 0.05) was evident using SHG. Similar increases and patterns of staining were observed using parallel traditional picrosirius red staining of collagen. Label-free SHG microscopy provides a new alternative method for quantifying collagen deposition in fibrotic hearts.
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Affiliation(s)
- Tamara P Martin
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Wolfson Link building, Glasgow, G12 8QQ, UK
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Li W, Goldstein DR, Kreisel D. Intravital 2-photon imaging, leukocyte trafficking, and the beating heart. Trends Cardiovasc Med 2013; 23:287-93. [PMID: 23706535 DOI: 10.1016/j.tcm.2013.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 03/29/2013] [Accepted: 04/01/2013] [Indexed: 01/13/2023]
Abstract
Intravital two-photon microscopy allows for the analysis of single-cell dynamics within intact tissues. As it is well recognized that molecular cues that regulate leukocyte trafficking into inflammatory sites differ between various tissues, it is important to study organ-specific responses. Recently, intravital two-photon microscopy has been expanded to moving organs in the mouse such as beating hearts. Unlike previous experimental approaches to image cardiac tissue explants or isolated perfused heart preparations by two-photon microscopy, intravital imaging accounts for the mechanical force transmitted to vessels by the heartbeat and accurately assesses dynamic leukocyte behavior in the coronary vessels and myocardial tissue. Intravital two-photon imaging of beating hearts is a promising experimental tool that will help elucidate cellular and molecular immune processes that contribute to a variety of cardiovascular diseases.
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Affiliation(s)
- Wenjun Li
- Department of Surgery, Washington University in St. Louis, New Haven, CT, USA
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Caorsi V, Toepfer C, Sikkel MB, Lyon AR, MacLeod K, Ferenczi MA. Non-linear optical microscopy sheds light on cardiovascular disease. PLoS One 2013; 8:e56136. [PMID: 23409139 PMCID: PMC3567079 DOI: 10.1371/journal.pone.0056136] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 01/05/2013] [Indexed: 11/29/2022] Open
Abstract
Many cardiac diseases have been associated with increased fibrosis and changes in the organization of fibrillar collagen. The degree of fibrosis is routinely analyzed with invasive histological and immunohistochemical methods, giving a limited and qualitative understanding of the tissue's morphological adaptation to disease. Our aim is to quantitatively evaluate the increase in fibrosis by three-dimensional imaging of the collagen network in the myocardium using the non-linear optical microscopy techniques Two-Photon Excitation microscopy (TPE) and Second Harmonic signal Generation (SHG). No sample staining is needed because numerous endogenous fluorophores are excited by a two-photon mechanism and highly non-centrosymmetric structures such as collagen generate strong second harmonic signals. We propose for the first time a 3D quantitative analysis to carefully evaluate the increased fibrosis in tissue from a rat model of heart failure post myocardial infarction. We show how to measure changes in fibrosis from the backward SHG (BSHG) alone, as only backward-propagating SHG is accessible for true in vivo applications. A 5-fold increase in collagen I fibrosis is detected in the remote surviving myocardium measured 20 weeks after infarction. The spatial distribution is also shown to change markedly, providing insight into the morphology of disease progression.
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Affiliation(s)
- Valentina Caorsi
- Molecular Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom.
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Gan Y, Fleming CP. Extracting three-dimensional orientation and tractography of myofibers using optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2013; 4:2150-65. [PMID: 24156071 PMCID: PMC3799673 DOI: 10.1364/boe.4.002150] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 09/05/2013] [Accepted: 09/09/2013] [Indexed: 05/03/2023]
Abstract
Abnormal changes in orientation of myofibers are associated with various cardiac diseases such as arrhythmia, irregular contraction, and cardiomyopathy. To extract fiber information, we present a method of quantifying fiber orientation and reconstructing three-dimensional tractography of myofibers using optical coherence tomography (OCT). A gradient based algorithm was developed to quantify fiber orientation in three dimensions and particle filtering technique was employed to track myofibers. Prior to image processing, three-dimensional image data set were acquired from all cardiac chambers and ventricular septum of swine hearts using OCT system without optical clearing. The algorithm was validated through rotation test and comparison with manual measurements. The experimental results demonstrate that we are able to visualize three-dimensional fiber tractography in myocardium tissues.
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Tsai MR, Shieh DB, Lou PJ, Lin CF, Sun CK. Characterization of oral squamous cell carcinoma based on higher-harmonic generation microscopy. JOURNAL OF BIOPHOTONICS 2012; 5:415-424. [PMID: 22461232 DOI: 10.1002/jbio.201100144] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Revised: 02/19/2012] [Accepted: 02/23/2012] [Indexed: 05/31/2023]
Abstract
In vivo higher-harmonic generation microscopy (HGM) performed on healthy human oral mucosa not only provides images with a <500 nm lateral resolution at a 280 μm penetration depth, but also leaves no photodamages in the tissues. These advantages suggest that HGM could serve as an ideal virtual biopsy tool for in vivo, in situ, and immediate histopathological diagnosis of oral cancer. However, translation of such mechanism for clinical cancer diagnosis requires evidence based algorithm capable to differentiate cancerous tissues from normal. It is thus critical to investigate if the endogenous contrast provided by the HGM would be high enough to differentiate cancerous versus normal tissues in human oral mucosa. In this report, ex vivo HGM study was performed on the cancerous mucosa from 10 patients with oral squamous cell carcinoma. Compared with histology, HGM revealed histopathological features including the cytological abnormalities, loss of differentiation, interruption of basement membrane, and irregular epithelial stratification in all 10 specimens. In addition, distinct patterns of collagen fibers and increased distribution area of actin filaments in tumor cells were noted. These results indicate HGM holds great potential for the optical biopsy screening of oral cancer lesions.
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Affiliation(s)
- Ming-Rung Tsai
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan
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Medyukhina A, Vogler N, Latka I, Kemper S, Böhm M, Dietzek B, Popp J. Automated classification of healthy and keloidal collagen patterns based on processing of SHG images of human skin. JOURNAL OF BIOPHOTONICS 2011; 4:627-636. [PMID: 21595044 DOI: 10.1002/jbio.201100028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 04/30/2011] [Accepted: 05/02/2011] [Indexed: 05/30/2023]
Abstract
All-optical microspectroscopic and tomographic tools have a great potential for the clinical investigation of human skin and skin diseases. However, automated optical tomography or even microscopy generate immense data sets. Therefore, in order to implement such diagnostic tools into the medical practice in both hospitals and private practice, there is a need for automated data handling and image analysis ideally implementing automized scores to judge the physiological state of a tissue section. In this contribution, the potential of an image processing algorithm for the automated classification of skin into normal or keloid based on second-harmonic generation (SHG) microscopic images is demonstrated. Such SHG data is routinely recorded within a multimodal imaging approach. The classification of the tissue implemented in the algorithm employs the geometrical features of collagen patterns that differ depending on the constitution, i.e., physiological status of the skin.
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Affiliation(s)
- Anna Medyukhina
- Institute of Photonic Technology, Albert-Einstein-Str. 9, 07745 Jena, Germany
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Chiu YW, Lo MT, Tsai MR, Chang YC, Hsu RB, Yu HY, Sun CK, Ho YL. Applying harmonic optical microscopy for spatial alignment of atrial collagen fibers. PLoS One 2010; 5:e13917. [PMID: 21085489 PMCID: PMC2976704 DOI: 10.1371/journal.pone.0013917] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Accepted: 10/18/2010] [Indexed: 01/18/2023] Open
Abstract
Background Atrial fibrosis creates a vulnerable tissue for atrial fibrillation (AF), but the spatial disarray of collagen fibers underlying atrial fibrosis is not fully elucidated. Objective This study hypothesizes that harmonics optical microscopy can illuminate the spatial mal-alignment of collagen fibers in AF via a layer-by-layer approach. Patients and Methods Atrial tissues taken from patients who underwent open-heart surgery were examined by harmonics optical microscopy. Using the two-dimensional Fourier transformation method, a spectral-energy description of image texture was constituted and its entropy was used to quantify the mal-alignment of collagen fibers. The amount of collagen fiber was derived from its area ratio to total atrial tissue in each image. Serum C-terminal pro-collagen pro-peptide (CICP), pro-matrix metalloproteinase-1 (pro-MMP-1), and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) were also evaluated. Results 46 patients were evaluated, including 20 with normal sinus rhythm and 26 with AF. The entropy of spectral-energy distribution of collagen alignment was significantly higher in AF than that in sinus rhythm (3.97±0.33 vs. 2.80±0.18, p<0.005). This difference was more significant in the permanent AF group. The amount of collagen was also significantly higher in AF patients (0.39±0.13 vs. 0.18±0.06, p<0.005) but serum markers of cardiac fibrosis were not significantly different between the two groups. Conclusions Harmonics optical microscopy can quantify the spatial mal-alignment of collagen fibers in AF. The entropy of spectral-energy distribution of collagen alignment is a potential tool for research in atrial remodeling.
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Affiliation(s)
- Yu-Wei Chiu
- Division of Cardiology, Department of Internal Medicine, Far-Eastern Memorial Hospital, Taipei, Taiwan
| | - Men Tzung Lo
- Research Center for Adaptive Data Analysis, National Central University, Taoyuan, Taiwan
| | - Ming-Rung Tsai
- Department of Electrical Engineering, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan
| | - Yi-Chung Chang
- Graduate Institute of Communication Engineering, National Taiwan University, Taipei, Taiwan
| | - Rong-Bin Hsu
- Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Hsu-Yu Yu
- Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
| | - Chi-Kuang Sun
- Department of Electrical Engineering, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan
| | - Yi-Lwun Ho
- Graduate Institute of Clinical Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
- Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
- * E-mail:
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