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Refaat A, Yap ML, Pietersz G, Walsh APG, Zeller J, Del Rosal B, Wang X, Peter K. In vivo fluorescence imaging: success in preclinical imaging paves the way for clinical applications. J Nanobiotechnology 2022; 20:450. [PMID: 36243718 PMCID: PMC9571426 DOI: 10.1186/s12951-022-01648-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 09/23/2022] [Indexed: 11/10/2022] Open
Abstract
Advances in diagnostic imaging have provided unprecedented opportunities to detect diseases at early stages and with high reliability. Diagnostic imaging is also crucial to monitoring the progress or remission of disease and thus is often the central basis of therapeutic decision-making. Currently, several diagnostic imaging modalities (computed tomography, magnetic resonance imaging, and positron emission tomography, among others) are routinely used in clinics and present their own advantages and limitations. In vivo near-infrared (NIR) fluorescence imaging has recently emerged as an attractive imaging modality combining low cost, high sensitivity, and relative safety. As a preclinical tool, it can be used to investigate disease mechanisms and for testing novel diagnostics and therapeutics prior to their clinical use. However, the limited depth of tissue penetration is a major challenge to efficient clinical use. Therefore, the current clinical use of fluorescence imaging is limited to a few applications such as image-guided surgery on tumors and retinal angiography, using FDA-approved dyes. Progress in fluorophore development and NIR imaging technologies holds promise to extend their clinical application to oncology, cardiovascular diseases, plastic surgery, and brain imaging, among others. Nanotechnology is expected to revolutionize diagnostic in vivo fluorescence imaging through targeted delivery of NIR fluorescent probes using antibody conjugation. In this review, we discuss the latest advances in in vivo fluorescence imaging technologies, NIR fluorescent probes, and current and future clinical applications.
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Affiliation(s)
- Ahmed Refaat
- Atherothrombosis and Vascular Biology Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Molecular Imaging and Theranostics Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Department of Engineering Technologies, Swinburne University of Technology, Melbourne, VIC, Australia.,Pharmaceutics Department, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - May Lin Yap
- Atherothrombosis and Vascular Biology Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
| | - Geoffrey Pietersz
- Atherothrombosis and Vascular Biology Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Burnet Institute, Melbourne, VIC, Australia.,Department of Cardiometabolic Health, University of Melbourne, Melbourne, VIC, Australia
| | - Aidan Patrick Garing Walsh
- Atherothrombosis and Vascular Biology Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Molecular Imaging and Theranostics Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Department of Medicine, Monash University, Melbourne, VIC, Australia
| | - Johannes Zeller
- Atherothrombosis and Vascular Biology Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Department of Plastic and Hand Surgery, University of Freiburg Medical Center, Freiburg, Germany
| | | | - Xiaowei Wang
- Atherothrombosis and Vascular Biology Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia. .,Molecular Imaging and Theranostics Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia. .,Department of Cardiometabolic Health, University of Melbourne, Melbourne, VIC, Australia. .,Department of Medicine, Monash University, Melbourne, VIC, Australia. .,Baker Department of Cardiovascular Research, Translation and Implementation, La Trobe University, Melbourne, VIC, Australia.
| | - Karlheinz Peter
- Atherothrombosis and Vascular Biology Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia. .,Department of Cardiometabolic Health, University of Melbourne, Melbourne, VIC, Australia. .,Department of Medicine, Monash University, Melbourne, VIC, Australia. .,Baker Department of Cardiovascular Research, Translation and Implementation, La Trobe University, Melbourne, VIC, Australia.
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Rapid Tuberculosis Diagnosis Using Reporter Enzyme Fluorescence. J Clin Microbiol 2019; 57:JCM.01462-19. [PMID: 31511338 PMCID: PMC6879286 DOI: 10.1128/jcm.01462-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 09/06/2019] [Indexed: 12/20/2022] Open
Abstract
Tuberculosis is the most frequent cause of death in humans from a single infectious agent. Due to low numbers of bacteria present in sputum during early infection, diagnosis does not usually occur until >3 to 4 months after symptoms develop. We created a new more sensitive diagnostic that can be carried out in 10 min with no processing or technical expertise. Tuberculosis is the most frequent cause of death in humans from a single infectious agent. Due to low numbers of bacteria present in sputum during early infection, diagnosis does not usually occur until >3 to 4 months after symptoms develop. We created a new more sensitive diagnostic that can be carried out in 10 min with no processing or technical expertise. This assay utilizes the Mycobacterium tuberculosis-specific biomarker BlaC in reporter enzyme fluorescence (REF) that has been optimized for clinical samples, designated REFtb, along with a more specific fluorogenic substrate, CDG-3. We report the first evaluation of clinical specimens with REFtb assays in comparison to the gold standards for tuberculosis diagnosis, culture and smear microscopy. REFtb assays allowed diagnosis of 160 patients from 16 different countries with a sensitivity of 89% for smear-positive, culture-positive samples and 88% for smear-negative, culture-positive samples with a specificity of 82%. The negative predictive value of REFtb for tuberculosis infection is 93%, and the positive predictive value is 79%. Overall, these data point toward the need for larger accuracy studies by third parties using a commercially available REFtb kit to determine whether incorporation of REFtb into the clinical toolbox for suspected tuberculosis patients would improve case identification. If results similar to our own can be obtained by all diagnostic laboratories, REFtb would allow proper treatment of more than 85% of patients that would be missed during their initial visit to a clinic using current diagnostic strategies, reducing the potential for further spread of disease.
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Durkee MS, Cirillo JD, Maitland KC. Fluorescence modeling of in vivo optical detection of Mycobacterium tuberculosis. BIOMEDICAL OPTICS EXPRESS 2019; 10:5445-5460. [PMID: 31646057 PMCID: PMC6788618 DOI: 10.1364/boe.10.005445] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/23/2019] [Accepted: 09/23/2019] [Indexed: 05/03/2023]
Abstract
Tuberculosis is one of the deadliest infectious diseases worldwide. New tools to study pathogenesis and monitor subjects in pre-clinical studies to develop treatment regimens are critical for progress. We developed an improved optical system for detecting bacteria in lungs of mice using internal illumination. We present a computational optical model of the full mouse torso to characterize the optical system. Simulated theoretical limits for the lowest detectable bacterial load support the experimental improvements with an internal illumination source, and suggest that protocol improvements could further lower the detection threshold.
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Affiliation(s)
- Madeleine S. Durkee
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Jeffrey D. Cirillo
- Department of Microbial Pathogenesis and Immunology, Texas A&M College of Medicine, Bryan, TX 77807, USA
| | - Kristen C. Maitland
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
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Monitoring Tuberculosis Drug Activity in Live Animals by Near-Infrared Fluorescence Imaging. Antimicrob Agents Chemother 2019:AAC.01280-19. [PMID: 31527027 DOI: 10.1128/aac.01280-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Worldwide, tuberculosis (TB) is the leading cause of death due to infection with a single pathogenic agent, Mycobacterium tuberculosis In the absence of an effective vaccine, new, more powerful antibiotics are required to halt the growing spread of multidrug-resistant strains and to shorten the duration of TB treatment. However, assessing drug efficacy at the preclinical stage remains a long and fastidious procedure that delays progression of drugs down the pipeline and towards the clinic. In this investigation, we report the construction, optimization and characterization of genetically engineered near-infrared (NIR) fluorescent reporter strains of the pathogens Mycobacterium marinum and Mycobacterium tuberculosis that enable direct visualization of bacteria in infected zebrafish and mice, respectively. Fluorescence could be measured precisely in infected immunodeficient mice, while its intensity appeared to be below the limit of detection in immunocompetent mice, probably because of the lower bacterial load obtained in these animals. Furthermore, we show that the fluorescence level accurately reflects the bacterial load, as determined by colony forming unit (CFU) enumeration, thus enabling the efficacy of antibiotic treatment to be assessed in live animals in real time. The NIR fluorescent imaging system disclosed here is a valuable resource for TB research and can serve to accelerate drug development.
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5
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Draganski A, Tar MT, Villegas G, Friedman JM, Davies KP. Topically Applied Curcumin-Loaded Nanoparticles Treat Erectile Dysfunction in a Rat Model of Type-2 Diabetes. J Sex Med 2018; 15:645-653. [DOI: 10.1016/j.jsxm.2018.03.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Revised: 02/16/2018] [Accepted: 03/09/2018] [Indexed: 12/22/2022]
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Durkee MS, Nooshabadi F, Cirillo JD, Maitland KC. Optical model of the murine lung to optimize pulmonary illumination. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-12. [PMID: 29573254 PMCID: PMC8355613 DOI: 10.1117/1.jbo.23.7.071208] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 03/01/2018] [Indexed: 05/05/2023]
Abstract
We describe a Monte Carlo model of the mouse torso to optimize illumination of the mouse lung for fluorescence detection of low levels of pulmonary pathogens, specifically Mycobacterium tuberculosis. After validation of the simulation with an internally illuminated optical phantom, the entire mouse torso was simulated to compare external and internal illumination techniques. Measured optical properties of deflated mouse lungs were scaled to mimic the diffusive properties of inflated lungs in vivo. Using the full-torso model, a 2 × to 3 × improvement in average fluence rate in the lung was seen for dorsal compared with ventral positioning of the mouse with external illumination. The enhancement in average fluence rate in the lung using internal excitation was 40 × to 60 × over external illumination in the dorsal position. Parameters of the internal fiber optic source were manipulated in the model to guide optimization of the physical system and experimental protocol for internal illumination and whole-body detection of fluorescent mycobacteria in a mouse model of infection.
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Affiliation(s)
- Madeleine S. Durkee
- Texas A&M University, Department of Biomedical Engineering, College Station, Texas, United States
| | - Fatemeh Nooshabadi
- Texas A&M University, Department of Biomedical Engineering, College Station, Texas, United States
| | - Jeffrey D. Cirillo
- Texas A&M Health Science Center, Department of Molecular Pathogenesis and Immunology, Bryan, Texas, United States
| | - Kristen C. Maitland
- Texas A&M University, Department of Biomedical Engineering, College Station, Texas, United States
- Address all correspondence to: Kristen C. Maitland, E-mail:
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Sharan R, Yang HJ, Sule P, Cirillo JD. Imaging Mycobacterium tuberculosis in Mice with Reporter Enzyme Fluorescence. J Vis Exp 2018:56801. [PMID: 29553533 PMCID: PMC5931367 DOI: 10.3791/56801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Reporter enzyme fluorescence (REF) utilizes substrates that are specific for enzymes present in target organisms of interest for imaging or detection by fluorescence or bioluminescence. We utilize BlaC, an enzyme expressed constitutively by all M. tuberculosis strains. REF allows rapid quantification of bacteria in lungs of infected mice. The same group of mice can be imaged at many time points, greatly reducing costs, enumerating bacteria more quickly, allowing novel observations in host-pathogen interactions, and increasing statistical power, since more animals per group are readily maintained. REF is extremely sensitive due to the catalytic nature of the BlaC enzymatic reporter and specific due to the custom flourescence resonance energy transfer (FRET) or fluorogenic substrates used. REF does not require recombinant strains, ensuring normal host-pathogen interactions. We describe the imaging of M. tuberculosis infection using a FRET substrate with maximal emission at 800 nm. The wavelength of the substrate allows sensitive deep tissue imaging in mammals. We will outline aerosol infection of mice with M. tuberculosis, anesthesia of mice, administration of the REF substrate, and optical imaging. This method has been successfully applied to evaluating host-pathogen interactions and efficacy of antibiotics targeting M. tuberculosis.
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Affiliation(s)
- Riti Sharan
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center
| | - Hee-Jeong Yang
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health
| | - Preeti Sule
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center
| | - Jeffrey D Cirillo
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center;
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8
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Durkee MS, Nash LD, Nooshabadi F, Cirillo JD, Maitland DJ, Maitland KC. Fabrication and Characterization of Optical Tissue Phantoms Containing Macrostructure. J Vis Exp 2018. [PMID: 29553502 DOI: 10.3791/57031] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The rapid development of new optical imaging techniques is dependent on the availability of low-cost, customizable, and easily reproducible standards. By replicating the imaging environment, costly animal experiments to validate a technique may be circumvented. Predicting and optimizing the performance of in vivo and ex vivo imaging techniques requires testing on samples that are optically similar to tissues of interest. Tissue-mimicking optical phantoms provide a standard for evaluation, characterization, or calibration of an optical system. Homogenous polymer optical tissue phantoms are widely used to mimic the optical properties of a specific tissue type within a narrow spectral range. Layered tissues, such as the epidermis and dermis, can be mimicked by simply stacking these homogenous slab phantoms. However, many in vivo imaging techniques are applied to more spatially complex tissue where three dimensional structures, such as blood vessels, airways, or tissue defects, can affect the performance of the imaging system. This protocol describes the fabrication of a tissue-mimicking phantom that incorporates three-dimensional structural complexity using material with optical properties of tissue. Look-up tables provide India ink and titanium dioxide recipes for optical absorption and scattering targets. Methods to characterize and tune the material optical properties are described. The phantom fabrication detailed in this article has an internal branching mock airway void; however, the technique can be broadly applied to other tissue or organ structures.
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Affiliation(s)
| | - Landon D Nash
- Department of Biomedical Engineering, Texas A&M University
| | | | - Jeffrey D Cirillo
- Deparment of Molecular Pathogenesis and Immunology, Texas A&M College of Medicine
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Abstract
The interaction between the host and the pathogen is extremely complex and is affected by anatomical, physiological, and immunological diversity in the microenvironments, leading to phenotypic diversity of the pathogen. Phenotypic heterogeneity, defined as nongenetic variation observed in individual members of a clonal population, can have beneficial consequences especially in fluctuating stressful environmental conditions. This is all the more relevant in infections caused by Mycobacterium tuberculosis wherein the pathogen is able to survive and often establish a lifelong persistent infection in the host. Recent studies in tuberculosis patients and in animal models have documented the heterogeneous and diverging trajectories of individual lesions within a single host. Since the fate of the individual lesions appears to be determined by the local tissue environment rather than systemic response of the host, studying this heterogeneity is very relevant to ensure better control and complete eradication of the pathogen from individual lesions. The heterogeneous microenvironments greatly enhance M. tuberculosis heterogeneity influencing the growth rates, metabolic potential, stress responses, drug susceptibility, and eventual lesion resolution. Single-cell approaches such as time-lapse microscopy using microfluidic devices allow us to address cell-to-cell variations that are often lost in population-average measurements. In this review, we focus on some of the factors that could be considered as drivers of phenotypic heterogeneity in M. tuberculosis as well as highlight some of the techniques that are useful in addressing this issue.
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10
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Nooshabadi F, Yang HJ, Cheng Y, Durkee MS, Xie H, Rao J, Cirillo JD, Maitland KC. Intravital excitation increases detection sensitivity for pulmonary tuberculosis by whole-body imaging with β-lactamase reporter enzyme fluorescence. JOURNAL OF BIOPHOTONICS 2017; 10:821-829. [PMID: 27753271 PMCID: PMC5703064 DOI: 10.1002/jbio.201600132] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 08/08/2016] [Accepted: 09/18/2016] [Indexed: 05/08/2023]
Abstract
Tuberculosis is a pulmonary disease with an especially high mortality rate in immuno-compromised populations, specifically children and HIV positive individuals. The causative agent, Mycobacterium tuberculosis (Mtb), is a very slow growing and difficult organism to work with, making both diagnosis and development of effective treatments cumbersome. We utilize a fiber-optic fluorescence microendoscope integrated with a whole-body imaging system for in vivo Mtb detection. The system exploits an endogenous enzyme of Mtb (β-lactamase, or BlaC) using a BlaC-specific NIR fluorogenic substrate. In the presence of BlaC, this substrate is cleaved and becomes fluorescent. Using intravital illumination of the lung to excite this probe, sensitivity of the optical system increases over trans- and epi-illumination methods of whole-body fluorescence imaging. We demonstrate that integration of these imaging technologies with BlaC-specific fluorescent reporter probe improves the level of detection to ∼100 colony forming units, a 100× increase in sensitivity in comparison to epi-illumination and a 10× increase in sensitivity in comparison to previous work in intravital excitation of tdTomato-expressing Mtb. This lower detection threshold enables the study of early stage bacterial infections with clinical strains of Mtb and longitudinal studies of disease pathogenesis and therapeutic efficacy with multiple time points in a single animal.
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Affiliation(s)
- Fatemeh Nooshabadi
- Biomedical Engineering Department, 3120 TAMU, Texas A&M University, College Station, TX 77843, United States
| | - Hee-Jeong Yang
- Microbial Pathogenesis and Immunology Department, Texas A&M University Health Science Center, Bryan, Texas 77807, United States
| | - Yunfeng Cheng
- Radiology Department, Stanford University, Stanford, CA 94304, United States
| | - Madeleine S. Durkee
- Biomedical Engineering Department, 3120 TAMU, Texas A&M University, College Station, TX 77843, United States
| | - Hexin Xie
- Radiology Department, Stanford University, Stanford, CA 94304, United States
| | - Jianghong Rao
- Radiology Department, Stanford University, Stanford, CA 94304, United States
| | - Jeffrey D. Cirillo
- Microbial Pathogenesis and Immunology Department, Texas A&M University Health Science Center, Bryan, Texas 77807, United States
| | - Kristen C. Maitland
- Biomedical Engineering Department, 3120 TAMU, Texas A&M University, College Station, TX 77843, United States
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11
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Nooshabadi F, Yang HJ, Cheng Y, Durkee MS, Xie H, Rao J, Cirillo JD, Maitland KC. Intravital excitation increases detection sensitivity for pulmonary tuberculosis by whole-body imaging with β-lactamase reporter enzyme fluorescence. JOURNAL OF BIOPHOTONICS 2017; 10:821-829. [PMID: 27753271 DOI: 10.1002/jbio.v10.6-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 08/08/2016] [Accepted: 09/18/2016] [Indexed: 05/22/2023]
Abstract
Tuberculosis is a pulmonary disease with an especially high mortality rate in immuno-compromised populations, specifically children and HIV positive individuals. The causative agent, Mycobacterium tuberculosis (Mtb), is a very slow growing and difficult organism to work with, making both diagnosis and development of effective treatments cumbersome. We utilize a fiber-optic fluorescence microendoscope integrated with a whole-body imaging system for in vivo Mtb detection. The system exploits an endogenous enzyme of Mtb (β-lactamase, or BlaC) using a BlaC-specific NIR fluorogenic substrate. In the presence of BlaC, this substrate is cleaved and becomes fluorescent. Using intravital illumination of the lung to excite this probe, sensitivity of the optical system increases over trans- and epi-illumination methods of whole-body fluorescence imaging. We demonstrate that integration of these imaging technologies with BlaC-specific fluorescent reporter probe improves the level of detection to ∼100 colony forming units, a 100× increase in sensitivity in comparison to epi-illumination and a 10× increase in sensitivity in comparison to previous work in intravital excitation of tdTomato-expressing Mtb. This lower detection threshold enables the study of early stage bacterial infections with clinical strains of Mtb and longitudinal studies of disease pathogenesis and therapeutic efficacy with multiple time points in a single animal.
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Affiliation(s)
- Fatemeh Nooshabadi
- Biomedical Engineering Department, 3120 TAMU, Texas A&M University, College Station, TX, 77843, United States
| | - Hee-Jeong Yang
- Microbial Pathogenesis and Immunology Department, Texas A&M University Health Science Center, Bryan, TX, 77807, United States
| | - Yunfeng Cheng
- Radiology Department, Stanford University, Stanford, CA, 94304, United States
| | - Madeleine S Durkee
- Biomedical Engineering Department, 3120 TAMU, Texas A&M University, College Station, TX, 77843, United States
| | - Hexin Xie
- Radiology Department, Stanford University, Stanford, CA, 94304, United States
| | - Jianghong Rao
- Radiology Department, Stanford University, Stanford, CA, 94304, United States
| | - Jeffrey D Cirillo
- Microbial Pathogenesis and Immunology Department, Texas A&M University Health Science Center, Bryan, TX, 77807, United States
| | - Kristen C Maitland
- Biomedical Engineering Department, 3120 TAMU, Texas A&M University, College Station, TX, 77843, United States
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12
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Dwork N, Lasry EM, Pauly JM, Balbás J. Formulation of image fusion as a constrained least squares optimization problem. J Med Imaging (Bellingham) 2017; 4:014003. [PMID: 28331885 DOI: 10.1117/1.jmi.4.1.014003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 02/08/2017] [Indexed: 12/13/2022] Open
Abstract
Fusing a lower resolution color image with a higher resolution monochrome image is a common practice in medical imaging. By incorporating spatial context and/or improving the signal-to-noise ratio, it provides clinicians with a single frame of the most complete information for diagnosis. In this paper, image fusion is formulated as a convex optimization problem that avoids image decomposition and permits operations at the pixel level. This results in a highly efficient and embarrassingly parallelizable algorithm based on widely available robust and simple numerical methods that realizes the fused image as the global minimizer of the convex optimization problem.
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Affiliation(s)
- Nicholas Dwork
- Stanford University , Department of Electrical Engineering, Stanford, California, United States
| | - Eric M Lasry
- Stanford University , Pre-Collegiate Summer Institutes, Stanford, California, United States
| | - John M Pauly
- Stanford University , Department of Electrical Engineering, Stanford, California, United States
| | - Jorge Balbás
- California State University in Northridge , Department of Mathematics, Northridge, California, United States
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Sule P, Tilvawala R, Behinaein P, Walkup GK, Cirillo JD. New directions using reporter enzyme fluorescence (REF) as a tuberculosis diagnostic platform. Tuberculosis (Edinb) 2016; 101S:S78-S82. [PMID: 27729258 DOI: 10.1016/j.tube.2016.09.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Although tuberculosis (TB) is one of the most common causes of morbidity and mortality in humans worldwide and diagnostic methods have been in place for more than 100 years, diagnosis remains a challenge. The main problems with diagnosis relate to the time needed to obtain a definitive result, difficulty in obtaining sputum, the primary clinical material used, and the ability of the causative agent, Mycobacterium tuberculosis, to cause disease in nearly any tissue within the body. In order to decrease incidence of TB, discovery of a novel interventions will be required, since current technologies have only been able to control numbers of infections, not reduce them. Diagnostic innovation is particularly needed because there are no effective pediatric or extrapulmonary TB diagnostic methods and multiple-drug resistance is only identified in less than 25% of those patients that are thought to have it. The most common diagnostic method worldwide remains acid-fast stain on sputum, with a threshold of ∼10,000 bacteria/ml that is only reached ∼5-6 months after development of symptoms. In order to obtain definitive diagnostic results earlier during the disease process, we have developed a diagnostic method designated reporter enzyme fluorescence (REF) that utilizes BlaC produced by M. tuberculosis and custom substrates to produce a specific fluorescent signal with as few as 10 bacteria/ml in clinical samples. We believe that the unique biology of the REF technique will allow it to contribute new diagnostic information that is complementary to all existing diagnostic tests as well as those currently known to be in development.
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Affiliation(s)
- Preeti Sule
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Center for Airborne Pathogens Research and Imaging, Medical Research & Education Building, 8447 State Hwy 47, Bryan, TX 77807, USA
| | - Ronak Tilvawala
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Center for Airborne Pathogens Research and Imaging, Medical Research & Education Building, 8447 State Hwy 47, Bryan, TX 77807, USA
| | - Parnia Behinaein
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Center for Airborne Pathogens Research and Imaging, Medical Research & Education Building, 8447 State Hwy 47, Bryan, TX 77807, USA
| | - Grant K Walkup
- Agios Pharmaceuticals, 88 Sydney St., Cambridge, MA 02139, USA
| | - Jeffrey D Cirillo
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Center for Airborne Pathogens Research and Imaging, Medical Research & Education Building, 8447 State Hwy 47, Bryan, TX 77807, USA.
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