1
|
Pu F, Radosevich AJ, Bruckner BG, Fontaine DA, Panchal SC, Williams JD, Gopalakrishnan SM, Elsen NL. New Platform for Label-Free, Proximal Cellular Pharmacodynamic Assays: Identification of Glutaminase Inhibitors Using Infrared Matrix-Assisted Laser Desorption Electrospray Ionization Mass Spectrometry. ACS Chem Biol 2023; 18:942-948. [PMID: 37043689 DOI: 10.1021/acschembio.3c00087] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
Cellular pharmacodynamic assays are crucial aspects of lead optimization programs in drug discovery. These assays are sometimes difficult to develop, oftentimes distal from the target and frequently low throughput, which necessitates their incorporation in the drug discovery funnel later than desired. The earlier direct pharmacodynamic modulation of a target can be established, the fewer resources are wasted on compounds that are acting via an off-target mechanism. Mass spectrometry is a versatile tool that is often used for direct, proximal cellular pharmacodynamic assay analysis, but liquid chromatography-mass spectrometry methods are low throughput and are unable to fully support structure-activity relationship efforts in early medicinal chemistry programs. Infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) is an ambient ionization method amenable to high-throughput cellular assays, capable of diverse analyte detection, ambient and rapid laser sampling processes, and low cross-contamination. Here, we demonstrate the capability of IR-MALDESI for the detection of diverse analytes directly from cells and report the development of a high-throughput, label-free, proximal cellular pharmacodynamic assay using IR-MALDESI for the discovery of glutaminase inhibitors and a biochemical assay for hit confirmation. We demonstrate the throughput with a ∼100,000-compound cellular screen. Hits from the screening were confirmed by retesting in dose-response with mass spectrometry-based cellular and biochemical assays. A similar workflow can be applied to other targets with minimal modifications, which will speed up the discovery of cell active lead series and minimize wasted chemistry resources on off-target mechanisms.
Collapse
Affiliation(s)
- Fan Pu
- Discovery Research, AbbVie Inc., 1 North Waukegan Rd., North Chicago, Illinois 60064, United States
| | - Andrew J Radosevich
- Discovery Research, AbbVie Inc., 1 North Waukegan Rd., North Chicago, Illinois 60064, United States
| | - Brett G Bruckner
- Discovery Research, AbbVie Inc., 1 North Waukegan Rd., North Chicago, Illinois 60064, United States
| | - David A Fontaine
- Discovery Research, AbbVie Inc., 1 North Waukegan Rd., North Chicago, Illinois 60064, United States
| | - Sanjay C Panchal
- Discovery Research, AbbVie Inc., 1 North Waukegan Rd., North Chicago, Illinois 60064, United States
| | - Jon D Williams
- Discovery Research, AbbVie Inc., 1 North Waukegan Rd., North Chicago, Illinois 60064, United States
| | - Sujatha M Gopalakrishnan
- Discovery Research, AbbVie Inc., 1 North Waukegan Rd., North Chicago, Illinois 60064, United States
| | - Nathaniel L Elsen
- Discovery Research, AbbVie Inc., 1 North Waukegan Rd., North Chicago, Illinois 60064, United States
| |
Collapse
|
2
|
Radosevich AJ, Martin RL, Buck WR, Hicks L, Wilsey A, Pan JY. In-vitro modeling of intravenous drug precipitation by the optical spatial precipitation analyzer (OSPREY). Int J Pharm 2023; 636:122842. [PMID: 36925024 DOI: 10.1016/j.ijpharm.2023.122842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 03/02/2023] [Accepted: 03/10/2023] [Indexed: 03/15/2023]
Abstract
Intravenous (IV) administration of poorly water-soluble small molecule therapeutics can lead to precipitation during mixing with blood. This can limit characterization of pharmacological and safety endpoints in preclinical models. Most often, tests of kinetic and thermodynamic solubility are used to optimize the formulation for solubility prior to infusion in animals, but these do not capture the dynamic precipitation processes that take place during in-vivo administration. To better capture the fluid dynamic processes that occur during IV administration, we developed the Optical Spatial PREcipitation analYzer (OSPREY) as a method to quantify the amount and size of compound precipitates in whole blood using a flow-through system that mimics IV administration. Here, we describe the OSPREY device and its underlying imaging processing methods. We then validate the ability to accurately segment particles according to their size using monodisperse suspensions of microspheres (diameter 50 to 425 µm). Next, we use a tool compound, ABT-737, to study the effects of compound concentration, vessel flow rate, compound infusion rate and vessel diameter on precipitation. Finally, we use the physiological diameter and flow rate of rat femoral vein and dog saphenous vein to demonstrate the potential of OSPREY to model in-vivo precipitation in a controlled, dynamic in-vitro assay.
Collapse
Affiliation(s)
| | - Ruth L Martin
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL 60064, United States
| | - Wayne R Buck
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL 60064, United States
| | - Lauren Hicks
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL 60064, United States
| | - Amanda Wilsey
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL 60064, United States
| | - Jeffrey Y Pan
- AbbVie Inc., 1 North Waukegan Rd., North Chicago, IL 60064, United States
| |
Collapse
|
3
|
Pu F, Knizner KT, Robey MT, Radosevich AJ, Ugrin SA, Elsen NL, Durbin KR, Williams JD. High-Throughput Deconvolution of Intact Protein Mass Spectra for the Screening of Covalent Inhibitors. J Am Soc Mass Spectrom 2022; 33:2338-2341. [PMID: 36378849 DOI: 10.1021/jasms.2c00273] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Deconvolution from intact protein mass-to-charge spectra to mass spectra is essential to generate interpretable data for mass spectrometry (MS) platforms coupled to ionization sources that produce multiply charged species. Infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) can be used to analyze intact proteins in multiwell microtiter plates with speed matching small molecule analyses (at least 1 Hz). However, the lack of compatible deconvolution software has limited its use in high-throughput screening applications. Most existing automated deconvolution software packages work best for data generated from LC-MS, and to the best of our knowledge, there is no software capable of performing fast plate-based mass spectral deconvolution. Herein we present the use of a new workflow in ProSight Native for the deconvolution of protein spectra from entire well plates that can be completed within 3 s. First, we successfully demonstrated the potential increased throughput benefits produced by the combined IR-MALDESI-MS - ProSight Native platform using protein standards. We then conducted a screen for Bruton's tyrosine kinase (BTK) covalent binders against a well-annotated compound collection consisting of 2232 compounds and applied ProSight Native to deconvolute the protein spectra. Seventeen hits including five known BTK covalent inhibitors in the compound set were identified. By alleviating the data processing bottleneck using ProSight Native, it may be feasible to analyze and report covalent screening results for >200,000 samples in a single day.
Collapse
Affiliation(s)
- Fan Pu
- . Discovery Research, AbbVie, Inc., North Chicago, Illinois 60064, United States
| | - Kevan T Knizner
- . Discovery Research, AbbVie, Inc., North Chicago, Illinois 60064, United States
- . Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Matthew T Robey
- . Proteinaceous, Inc., Evanston, Illinois 60201, United States
| | - Andrew J Radosevich
- . Discovery Research, AbbVie, Inc., North Chicago, Illinois 60064, United States
| | - Scott A Ugrin
- . Discovery Research, AbbVie, Inc., North Chicago, Illinois 60064, United States
| | - Nathaniel L Elsen
- . Discovery Research, AbbVie, Inc., North Chicago, Illinois 60064, United States
| | | | - Jon D Williams
- . Discovery Research, AbbVie, Inc., North Chicago, Illinois 60064, United States
| |
Collapse
|
4
|
Knizner KT, Guymon JP, Garrard KP, Bouvrée G, Manni J, Hauschild JP, Strupat K, Fort KL, Earley L, Wouters ER, Pu F, Radosevich AJ, Elsen NL, Williams JD, Pankow MR, Muddiman DC. Next-Generation Infrared Matrix-Assisted Laser Desorption Electrospray Ionization Source for Mass Spectrometry Imaging and High-Throughput Screening. J Am Soc Mass Spectrom 2022; 33:2070-2077. [PMID: 36173393 PMCID: PMC9944128 DOI: 10.1021/jasms.2c00178] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) is a hybrid, ambient ionization source that combines the advantages of electrospray ionization and matrix-assisted laser desorption/ionization, making it a versatile tool for both high-throughput screening (HTS) and mass spectrometry imaging (MSI) studies. To expand the capabilities of the IR-MALDESI source, an entirely new architecture was designed to overcome the key limitations of the previous source. This next-generation (NextGen) IR-MALDESI source features a vertically mounted IR-laser, a planar translation stage with computerized sample height control, an aluminum enclosure, and a novel mass spectrometer interface plate. The NextGen IR-MALDESI source has improved user-friendliness, improved overall versatility, and can be coupled to numerous Orbitrap mass spectrometers to accommodate more research laboratories. In this work, we highlight the benefits of the NextGen IR-MALDESI source as an improved platform for MSI and direct analysis. We also optimize the NextGen MALDESI source component geometries to increase target ion abundances over a wide m/z range. Finally, documentation is provided for each NextGen IR-MALDESI part so that it can be replicated and incorporated into any lab space.
Collapse
Affiliation(s)
- Kevan T. Knizner
- FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Jacob P. Guymon
- Precision Engineering Consortium, Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh 27695, NC, USA
| | - Kenneth P. Garrard
- FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
- Precision Engineering Consortium, Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh 27695, NC, USA
- Molecular Education, Technology and Research Innovation Center (METRIC), North Carolina State University, Raleigh, NC 27695, USA
| | - Guy Bouvrée
- GB Conseil & Services, 77170 Brie Comte Robert, France
| | | | | | - Kerstin Strupat
- Thermo Fisher Scientific (Bremen) GmbH, 28199 Bremen, Germany
| | - Kyle L. Fort
- Thermo Fisher Scientific (Bremen) GmbH, 28199 Bremen, Germany
| | - Lee Earley
- Thermo Fisher Scientific, San Jose, CA 95134, USA
| | | | - Fan Pu
- Drug Discovery Science and Technology, AbbVie Inc., North Chicago, IL 60064, USA
| | - Andrew J. Radosevich
- Drug Discovery Science and Technology, AbbVie Inc., North Chicago, IL 60064, USA
| | - Nathaniel L. Elsen
- Drug Discovery Science and Technology, AbbVie Inc., North Chicago, IL 60064, USA
| | - Jon D. Williams
- Drug Discovery Science and Technology, AbbVie Inc., North Chicago, IL 60064, USA
| | - Mark R. Pankow
- Precision Engineering Consortium, Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh 27695, NC, USA
| | - David C. Muddiman
- FTMS Laboratory for Human Health Research, Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
- Molecular Education, Technology and Research Innovation Center (METRIC), North Carolina State University, Raleigh, NC 27695, USA
| |
Collapse
|
5
|
Pu F, Ugrin SA, Radosevich AJ, Chang-Yen D, Sawicki JW, Talaty NN, Elsen NL, Williams JD. High-Throughput Intact Protein Analysis for Drug Discovery Using Infrared Matrix-Assisted Laser Desorption Electrospray Ionization Mass Spectrometry. Anal Chem 2022; 94:13566-13574. [PMID: 36129783 DOI: 10.1021/acs.analchem.2c03211] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mass spectrometry (MS) is the primary analytical tool used to characterize proteins within the biopharmaceutical industry. Electrospray ionization (ESI) coupled to liquid chromatography (LC) is the current gold standard for intact protein analysis. However, inherent speed limitations of LC/MS prevent analysis of large sample numbers (>1000) in a day. Infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI-MS), an ambient ionization MS technology, has recently been established as a platform for high-throughput small molecule analysis. Here, we report the applications of such a system for the analysis of intact proteins commonly performed within the drug discovery process. A wide molecular weight range of proteins 10-150 kDa was detected on the system with improved tolerance to salts and buffers compared to ESI. With high concentrations and model proteins, a sample rate of up to 22 Hz was obtained. For proteins at low concentrations and in buffers used in commonly employed assays, robust data at a sample rate of 1.5 Hz were achieved, which is ∼22× faster than current technologies used for high-throughput ESI-MS-based protein assays. In addition, two multiplexed plate-based high-throughput sample cleanup methods were coupled to IR-MALDESI-MS to enable analysis of samples containing excessive amounts of salts and buffers without fully compromising productivity. Example experiments, which leverage the speed of the IR-MALDESI-MS system to monitor NISTmAb reduction, protein autophosphorylation, and compound binding kinetics in near real time, are demonstrated.
Collapse
Affiliation(s)
- Fan Pu
- AbbVie Inc, 1 North Waukegan Rd., North Chicago, Illinois 60064, United States
| | - Scott A Ugrin
- AbbVie Inc, 1 North Waukegan Rd., North Chicago, Illinois 60064, United States
| | - Andrew J Radosevich
- AbbVie Inc, 1 North Waukegan Rd., North Chicago, Illinois 60064, United States
| | - David Chang-Yen
- AbbVie Inc, 1 North Waukegan Rd., North Chicago, Illinois 60064, United States
| | - James W Sawicki
- AbbVie Inc, 1 North Waukegan Rd., North Chicago, Illinois 60064, United States
| | - Nari N Talaty
- AbbVie Inc, 1 North Waukegan Rd., North Chicago, Illinois 60064, United States
| | - Nathaniel L Elsen
- AbbVie Inc, 1 North Waukegan Rd., North Chicago, Illinois 60064, United States
| | - Jon D Williams
- AbbVie Inc, 1 North Waukegan Rd., North Chicago, Illinois 60064, United States
| |
Collapse
|
6
|
Radosevich AJ, Pu F, Chang-Yen D, Sawicki JW, Talaty NN, Elsen NL, Williams JD, Pan JY. Ultra-High-Throughput Ambient MS: Direct Analysis at 22 Samples per Second by Infrared Matrix-Assisted Laser Desorption Electrospray Ionization Mass Spectrometry. Anal Chem 2022; 94:4913-4918. [PMID: 35290016 DOI: 10.1021/acs.analchem.1c04605] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) mass spectrometry is an ambient-direct sampling method that is being developed for high-throughput, label-free, biochemical screening of large-scale compound libraries. Here, we report the development of an ultra-high-throughput continuous motion IR-MALDESI sampling approach capable of acquiring data at rates up to 22.7 samples per second in a 384-well microtiter plate. At top speed, less than 1% analyte carryover is observed from well-to-well, and signal intensity relative standard deviations (RSD) of 11.5% and 20.9% for 3 μM 1-hydroxymidazolam and 12 μM dextrorphan, respectively, are achieved. The ability to perform parallel kinetics studies on 384 samples with a ∼30 s time resolution using an isocitrate dehydrogenase 1 (IDH1) enzyme assay is shown. Finally, we demonstrate the repeatability and throughput of our approach by measuring 115200 samples from 300 microtiter plate reads consecutively over 5.54 h with RSDs under 8.14% for each freshly introduced plate. Taken together, these results demonstrate the use of IR-MALDESI at sample acquisition rates that surpass other currently reported direct sampling mass spectrometry approaches used for high-throughput compound screening.
Collapse
Affiliation(s)
- Andrew J Radosevich
- AbbVie Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - Fan Pu
- AbbVie Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - David Chang-Yen
- AbbVie Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - James W Sawicki
- AbbVie Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - Nari N Talaty
- AbbVie Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - Nathaniel L Elsen
- AbbVie Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - Jon D Williams
- AbbVie Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| | - Jeffrey Y Pan
- AbbVie Inc., 1 North Waukegan Road, North Chicago, Illinois 60064, United States
| |
Collapse
|
7
|
Pu F, Radosevich AJ, Sawicki JW, Chang-Yen D, Talaty NN, Gopalakrishnan SM, Williams JD, Elsen NL. High-Throughput Label-Free Biochemical Assays Using Infrared Matrix-Assisted Desorption Electrospray Ionization Mass Spectrometry. Anal Chem 2021; 93:6792-6800. [PMID: 33885291 DOI: 10.1021/acs.analchem.1c00737] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Mass spectrometry (MS) can provide high sensitivity and specificity for biochemical assays without the requirement of labels, eliminating the risk of assay interference. However, its use had been limited to lower-throughput assays due to the need for chromatography to overcome ion suppression from the sample matrix. Direct analysis without chromatography has the potential for high throughput if sensitivity is sufficient despite the presence of a matrix. Here, we report and demonstrate a novel direct analysis high-throughput MS system based on infrared matrix-assisted desorption electrospray ionization (IR-MALDESI) that has a potential acquisition rate of 33 spectra/s. We show the development of biochemical assays in standard buffers for wild-type isocitrate dehydrogenase 1 (IDH1), diacylglycerol kinase zeta (DGKζ), and p300 histone acetyltransferase (P300) to demonstrate the suitability of this system for a broad range of high-throughput lead discovery assays. A proof-of-concept pilot screen of ∼3k compounds is also shown for IDH1 and compared to a previously reported fluorescence-based assay. We were able to obtain reliable data at a speed amenable for high-throughput screening of large-scale compound libraries.
Collapse
Affiliation(s)
- Fan Pu
- Drug Discovery Science and Technology, AbbVie Inc., North Chicago, Illinois 60064, United States
| | - Andrew J Radosevich
- Drug Discovery Science and Technology, AbbVie Inc., North Chicago, Illinois 60064, United States
| | - James W Sawicki
- Drug Discovery Science and Technology, AbbVie Inc., North Chicago, Illinois 60064, United States
| | - David Chang-Yen
- Drug Discovery Science and Technology, AbbVie Inc., North Chicago, Illinois 60064, United States
| | - Nari N Talaty
- Drug Discovery Science and Technology, AbbVie Inc., North Chicago, Illinois 60064, United States
| | - Sujatha M Gopalakrishnan
- Drug Discovery Science and Technology, AbbVie Inc., North Chicago, Illinois 60064, United States
| | - Jon D Williams
- Drug Discovery Science and Technology, AbbVie Inc., North Chicago, Illinois 60064, United States
| | - Nathaniel L Elsen
- Drug Discovery Science and Technology, AbbVie Inc., North Chicago, Illinois 60064, United States
| |
Collapse
|
8
|
Eshein A, Radosevich AJ, Gould B, Wu W, Konda V, Yang LW, Koons A, Feder S, Valuckaite V, Roy HK, Backman V, Nguyen TQ. Fully automated fiber-based optical spectroscopy system for use in a clinical setting. J Biomed Opt 2018; 23:1-10. [PMID: 29981224 PMCID: PMC8357326 DOI: 10.1117/1.jbo.23.7.075003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 06/05/2018] [Indexed: 05/04/2023]
Abstract
While there are a plethora of in vivo fiber-optic spectroscopic techniques that have demonstrated the ability to detect a number of diseases in research trials with highly trained personnel familiar with the operation of experimental optical technologies, very few techniques show the same level of success in large multicenter trials. To meet the stringent requirements for a viable optical spectroscopy system to be used in a clinical setting, we developed components including an automated calibration tool, optical contact sensor for signal acquisition, and a methodology for real-time in vivo probe calibration correction. The end result is a state-of-the-art medical device that can be realistically used by a physician with spectroscopic fiber-optic probes. We show how the features of this system allow it to have excellent stability measuring two scattering phantoms in a clinical setting by clinical staff with ∼0.5 % standard deviation over 25 unique measurements on different days. In addition, we show the systems' ability to overcome many technical obstacles that spectroscopy applications often face such as speckle noise and user variability. While this system has been designed and optimized for our specific application, the system and design concepts are applicable to most in vivo fiber-optic-based spectroscopic techniques.
Collapse
Affiliation(s)
- Adam Eshein
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Andrew J. Radosevich
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Bradley Gould
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Wenli Wu
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Vani Konda
- University of Chicago Medicine, Center for Endoscopic Research and Therapeutics, Chicago, Illinois, United States
| | - Leslie W. Yang
- University of Chicago Medicine, Center for Endoscopic Research and Therapeutics, Chicago, Illinois, United States
| | - Ann Koons
- University of Chicago Medicine, Center for Endoscopic Research and Therapeutics, Chicago, Illinois, United States
| | - Seth Feder
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Vesta Valuckaite
- University of Chicago Medicine, Center for Endoscopic Research and Therapeutics, Chicago, Illinois, United States
| | - Hemant K. Roy
- Boston Medical Center, Department of Gastroenterology, Boston, Massachusetts, United States
| | - Vadim Backman
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - The-Quyen Nguyen
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
- Address all correspondence to: The-Quyen Nguyen, E-mail:
| |
Collapse
|
9
|
Roy HK, Turzhitsky V, Wali R, Radosevich AJ, Jovanovic B, Della'Zanna G, Umar A, Rubin DT, Goldberg MJ, Bianchi L, De La Cruz M, Bogojevic A, Helenowski IB, Rodriguez L, Chatterton R, Skripkauskas S, Page K, Weber CR, Huang X, Richmond E, Bergan RC, Backman V. Spectral biomarkers for chemoprevention of colonic neoplasia: a placebo-controlled double-blinded trial with aspirin. Gut 2017; 66:285-292. [PMID: 26503631 PMCID: PMC5108693 DOI: 10.1136/gutjnl-2015-309996] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 09/22/2015] [Accepted: 09/23/2015] [Indexed: 12/28/2022]
Abstract
OBJECTIVE A major impediment to translating chemoprevention to clinical practice has been lack of intermediate biomarkers. We previously reported that rectal interrogation with low-coherence enhanced backscattering spectroscopy (LEBS) detected microarchitectural manifestations of field carcinogenesis. We now wanted to ascertain if reversion of two LEBS markers spectral slope (SPEC) and fractal dimension (FRAC) could serve as a marker for chemopreventive efficacy. DESIGN We conducted a multicentre, prospective, randomised, double-blind placebo-controlled, clinical trial in subjects with a history of colonic neoplasia who manifested altered SPEC/FRAC in histologically normal colonic mucosa. Subjects (n=79) were randomised to 325 mg aspirin or placebo. The primary endpoint changed in FRAC and SPEC spectral markers after 3 months. Mucosal levels of prostaglandin E2 (PGE2) and UDP-glucuronosyltransferase (UGT)1A6 genotypes were planned secondary endpoints. RESULTS At 3 months, the aspirin group manifested alterations in SPEC (48.9%, p=0.055) and FRAC (55.4%, p=0.200) with the direction towards non-neoplastic status. As a measure of aspirin's pharmacological efficacy, we assessed changes in rectal PGE2 levels and noted that it correlated with SPEC and FRAC alterations (R=-0.55, p=0.01 and R=0.57, p=0.009, respectively) whereas there was no significant correlation in placebo specimens. While UGT1A6 subgroup analysis did not achieve statistical significance, the changes in SPEC and FRAC to a less neoplastic direction occurred only in the variant consonant with epidemiological evidence of chemoprevention. CONCLUSIONS We provide the first proof of concept, albeit somewhat underpowered, that spectral markers reversion mirrors antineoplastic efficacy providing a potential modality for titration of agent type/dose to optimise chemopreventive strategies in clinical practice. TRIAL NUMBER NCT00468910.
Collapse
Affiliation(s)
- Hemant K Roy
- Department of Medicine, Boston University Medical Center, Boston, Massachusetts, USA
| | - Vladimir Turzhitsky
- Department of Biomedical Engineering, Robert H. Lurie Cancer Center, Northwestern University, Chicago, Illinois, USA
| | - Ramesh Wali
- Department of Medicine, Boston University Medical Center, Boston, Massachusetts, USA
| | - Andrew J Radosevich
- Department of Biomedical Engineering, Robert H. Lurie Cancer Center, Northwestern University, Chicago, Illinois, USA
| | - Borko Jovanovic
- Department of Preventive Medicine, Robert H. Lurie Cancer Center, Northwestern University, Chicago, Illinois, USA
| | - Gary Della'Zanna
- Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland, USA
| | - Asad Umar
- Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland, USA
| | - David T Rubin
- Department of Medicine, The University of Chicago Medical Center, Chicago, Illinois, USA
| | - Michael J Goldberg
- Department of Medicine, NorthShore University Health Systems, Evanston, Illinois, USA
| | - Laura Bianchi
- Department of Medicine, NorthShore University Health Systems, Evanston, Illinois, USA
| | - Mart De La Cruz
- Department of Medicine, Boston University Medical Center, Boston, Massachusetts, USA
| | - Andrej Bogojevic
- Department of Medicine, NorthShore University Health Systems, Evanston, Illinois, USA
| | - Irene B Helenowski
- Department of Preventive Medicine, Robert H. Lurie Cancer Center, Northwestern University, Chicago, Illinois, USA
| | - Luz Rodriguez
- Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland, USA
| | - Robert Chatterton
- Department of Obstetrics and Gynecology, Robert H. Lurie Cancer Center, Northwestern University, Chicago, Illinois, USA
| | - Silvia Skripkauskas
- Department of Medicine, Robert H. Lurie Cancer Center, Northwestern University, Chicago, Illinois, USA
| | - Katherine Page
- Department of Medicine, Robert H. Lurie Cancer Center, Northwestern University, Chicago, Illinois, USA
| | - Christopher R Weber
- Department of Pathology, The University of Chicago Medical Center, Chicago, Illinois, USA
| | - Xiaoke Huang
- Department of Medicine, Robert H. Lurie Cancer Center, Northwestern University, Chicago, Illinois, USA
| | - Ellen Richmond
- Division of Cancer Prevention, National Cancer Institute, Bethesda, Maryland, USA
| | - Raymond C Bergan
- Department of Medicine, Robert H. Lurie Cancer Center, Northwestern University, Chicago, Illinois, USA
| | - Vadim Backman
- Department of Biomedical Engineering, Robert H. Lurie Cancer Center, Northwestern University, Chicago, Illinois, USA
| |
Collapse
|
10
|
Wu W, Radosevich AJ, Eshein A, Nguyen TQ, Yi J, Cherkezyan L, Roy HK, Szleifer I, Backman V. Using electron microscopy to calculate optical properties of biological samples. Biomed Opt Express 2016; 7:4749-4762. [PMID: 27896013 PMCID: PMC5119613 DOI: 10.1364/boe.7.004749] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 10/20/2016] [Accepted: 10/20/2016] [Indexed: 05/26/2023]
Abstract
The microscopic structural origins of optical properties in biological media are still not fully understood. Better understanding these origins can serve to improve the utility of existing techniques and facilitate the discovery of other novel techniques. We propose a novel analysis technique using electron microscopy (EM) to calculate optical properties of specific biological structures. This method is demonstrated with images of human epithelial colon cell nuclei. The spectrum of anisotropy factor g, the phase function and the shape factor D of the nuclei are calculated. The results show strong agreement with an independent study. This method provides a new way to extract the true phase function of biological samples and provides an independent validation for optical property measurement techniques.
Collapse
Affiliation(s)
- Wenli Wu
- Applied Physics Program, Northwestern University, Evanston, Illinois 60208, USA
| | - Andrew J. Radosevich
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Adam Eshein
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - The-Quyen Nguyen
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Ji Yi
- Department of Medicine, Boston University, Boston, Massachusetts 02118, USA
| | - Lusik Cherkezyan
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Hemant K. Roy
- Section of Gastroenterology, Boston Medical Center/Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Igal Szleifer
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, USA
| | - Vadim Backman
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, USA
| |
Collapse
|
11
|
Swain TD, DuBois E, Gomes A, Stoyneva VP, Radosevich AJ, Henss J, Wagner ME, Derbas J, Grooms HW, Velazquez EM, Traub J, Kennedy BJ, Grigorescu AA, Westneat MW, Sanborn K, Levine S, Schick M, Parsons G, Biggs BC, Rogers JD, Backman V, Marcelino LA. Skeletal light-scattering accelerates bleaching response in reef-building corals. BMC Ecol 2016; 16:10. [PMID: 26996922 PMCID: PMC4800776 DOI: 10.1186/s12898-016-0061-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 02/12/2016] [Indexed: 02/03/2023] Open
Abstract
Background At the forefront of ecosystems adversely affected by climate change, coral reefs are sensitive to anomalously high temperatures which disassociate (bleaching) photosynthetic symbionts (Symbiodinium) from coral hosts and cause increasingly frequent and severe mass mortality events. Susceptibility to bleaching and mortality is variable among corals, and is determined by unknown proportions of environmental history and the synergy of Symbiodinium- and coral-specific properties. Symbiodinium live within host tissues overlaying the coral skeleton, which increases light availability through multiple light-scattering, forming one of the most efficient biological collectors of solar radiation. Light-transport in the upper ~200 μm layer of corals skeletons (measured as ‘microscopic’ reduced-scattering coefficient, \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$ \mu ^{\prime}_{{S,m}} $$\end{document}μS,m′), has been identified as a determinant of excess light increase during bleaching and is therefore a potential determinant of the differential rate and severity of bleaching response among coral species. Results Here we experimentally demonstrate (in ten coral species) that, under thermal stress alone or combined thermal and light stress, low-\documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$ \mu ^{\prime}_{{S,m}} $$\end{document}μS,m′ corals bleach at higher rate and severity than high-\documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$ \mu ^{\prime}_{{S,m}} $$\end{document}μS,m′ corals and the Symbiodinium associated with low-\documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$ \mu ^{\prime}_{{S,m}} $$\end{document}μS,m′ corals experience twice the decrease in photochemical efficiency. We further modelled the light absorbed by Symbiodinium due to skeletal-scattering and show that the estimated skeleton-dependent light absorbed by Symbiodinium (per unit of photosynthetic pigment) and the temporal rate of increase in absorbed light during bleaching are several fold higher in low-\documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$ \mu ^{\prime}_{{S,m}} $$\end{document}μS,m′ corals. Conclusions While symbionts associated with low-\documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$ \mu ^{\prime}_{{S,m}} $$\end{document}μS,m′ corals receive less total light from the skeleton, they experience a higher rate of light increase once bleaching is initiated and absorbing bodies are lost; further precipitating the bleaching response. Because microscopic skeletal light-scattering is a robust predictor of light-dependent bleaching among the corals assessed here, this work establishes \documentclass[12pt]{minimal}
\usepackage{amsmath}
\usepackage{wasysym}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsbsy}
\usepackage{mathrsfs}
\usepackage{upgreek}
\setlength{\oddsidemargin}{-69pt}
\begin{document}$$ \mu ^{\prime}_{{S,m}} $$\end{document}μS,m′ as one of the key determinants of differential bleaching response. Electronic supplementary material The online version of this article (doi:10.1186/s12898-016-0061-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Timothy D Swain
- Department of Civil and Environmental Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA.,Department of Zoology, Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL, 60605, USA
| | - Emily DuBois
- Department of Civil and Environmental Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA.,Department of Zoology, Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL, 60605, USA
| | - Andrew Gomes
- Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Valentina P Stoyneva
- Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Andrew J Radosevich
- Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Jillian Henss
- Department of Civil and Environmental Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA.,Department of Zoology, Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL, 60605, USA
| | - Michelle E Wagner
- Department of Civil and Environmental Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA.,Department of Zoology, Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL, 60605, USA
| | - Justin Derbas
- Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Hannah W Grooms
- Department of Civil and Environmental Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Elizabeth M Velazquez
- Department of Civil and Environmental Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Joshua Traub
- Department of Civil and Environmental Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Brian J Kennedy
- Department of Civil and Environmental Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Arabela A Grigorescu
- Keck Biophysics Facility, Northwestern University, 633 Clark Street, Evanston, IL, 60208, USA
| | - Mark W Westneat
- Department of Zoology, Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL, 60605, USA
| | - Kevin Sanborn
- Fishes Department, John G. Shedd Aquarium, 1200 South Lake Shore Drive, Chicago, IL, 60605, USA
| | - Shoshana Levine
- Fishes Department, John G. Shedd Aquarium, 1200 South Lake Shore Drive, Chicago, IL, 60605, USA
| | - Mark Schick
- Fishes Department, John G. Shedd Aquarium, 1200 South Lake Shore Drive, Chicago, IL, 60605, USA
| | - George Parsons
- Fishes Department, John G. Shedd Aquarium, 1200 South Lake Shore Drive, Chicago, IL, 60605, USA
| | - Brendan C Biggs
- Division of Water Resource Management, Florida Department of Environmental Protection, 2600 Blair Stone Road, Tallahassee, 32399, USA
| | - Jeremy D Rogers
- Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Vadim Backman
- Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Luisa A Marcelino
- Department of Civil and Environmental Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA. .,Department of Zoology, Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL, 60605, USA.
| |
Collapse
|
12
|
Mutyal NN, Radosevich AJ, Bajaj S, Konda V, Siddiqui UD, Waxman I, Goldberg MJ, Rogers JD, Gould B, Eshein A, Upadhye S, Koons A, Gonzalez-Haba Ruiz M, Roy HK, Backman V. In vivo risk analysis of pancreatic cancer through optical characterization of duodenal mucosa. Pancreas 2015; 44:735-41. [PMID: 25906443 PMCID: PMC4464933 DOI: 10.1097/mpa.0000000000000340] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 10/17/2014] [Indexed: 12/18/2022]
Abstract
OBJECTIVES To reduce pancreatic cancer mortality, a paradigm shift in cancer screening is needed. Our group pioneered the use of low-coherence enhanced backscattering (LEBS) spectroscopy to predict the presence of pancreatic cancer by interrogating the duodenal mucosa. A previous ex vivo study (n = 203) demonstrated excellent diagnostic potential: sensitivity, 95%; specificity, 71%; and accuracy, 85%. The objective of the current case-control study was to evaluate this approach in vivo. METHODS We developed a novel endoscope-compatible fiber-optic probe to measure LEBS in the periampullary duodenum of 41 patients undergoing upper endoscopy. This approach enables minimally invasive detection of the ultrastructural consequences of pancreatic field carcinogenesis. RESULTS The LEBS parameters and optical properties were significantly altered in patients harboring adenocarcinomas (including early-stage) throughout the pancreas relative to healthy controls. Test performance characteristics were excellent with sensitivity = 78%, specificity = 85%, and accuracy = 81%. Moreover, the LEBS prediction rule was not confounded by patients' demographics. CONCLUSION We demonstrate the feasibility of in vivo measurement of histologically normal duodenal mucosa to predict the presence of adenocarcinoma throughout the pancreas. This represents the next step in establishing duodenal LEBS analysis as a prescreening technique that identifies clinically asymptomatic patients who are at elevated risk of PC.
Collapse
Affiliation(s)
- Nikhil N. Mutyal
- From the *Department of Biomedical Engineering, Northwestern University; †Department of Internal Medicine, NorthShore University HealthSystems, Evanston; ‡Center for Endoscopic Research and Therapeutics, University of Chicago Medicine, Chicago, IL; and §Department of Gastroenterology, Boston Medical Center, Boston, MA
| | - Andrew J. Radosevich
- From the *Department of Biomedical Engineering, Northwestern University; †Department of Internal Medicine, NorthShore University HealthSystems, Evanston; ‡Center for Endoscopic Research and Therapeutics, University of Chicago Medicine, Chicago, IL; and §Department of Gastroenterology, Boston Medical Center, Boston, MA
| | - Shailesh Bajaj
- From the *Department of Biomedical Engineering, Northwestern University; †Department of Internal Medicine, NorthShore University HealthSystems, Evanston; ‡Center for Endoscopic Research and Therapeutics, University of Chicago Medicine, Chicago, IL; and §Department of Gastroenterology, Boston Medical Center, Boston, MA
| | - Vani Konda
- From the *Department of Biomedical Engineering, Northwestern University; †Department of Internal Medicine, NorthShore University HealthSystems, Evanston; ‡Center for Endoscopic Research and Therapeutics, University of Chicago Medicine, Chicago, IL; and §Department of Gastroenterology, Boston Medical Center, Boston, MA
| | - Uzma D. Siddiqui
- From the *Department of Biomedical Engineering, Northwestern University; †Department of Internal Medicine, NorthShore University HealthSystems, Evanston; ‡Center for Endoscopic Research and Therapeutics, University of Chicago Medicine, Chicago, IL; and §Department of Gastroenterology, Boston Medical Center, Boston, MA
| | - Irving Waxman
- From the *Department of Biomedical Engineering, Northwestern University; †Department of Internal Medicine, NorthShore University HealthSystems, Evanston; ‡Center for Endoscopic Research and Therapeutics, University of Chicago Medicine, Chicago, IL; and §Department of Gastroenterology, Boston Medical Center, Boston, MA
| | - Michael J. Goldberg
- From the *Department of Biomedical Engineering, Northwestern University; †Department of Internal Medicine, NorthShore University HealthSystems, Evanston; ‡Center for Endoscopic Research and Therapeutics, University of Chicago Medicine, Chicago, IL; and §Department of Gastroenterology, Boston Medical Center, Boston, MA
| | - Jeremy D. Rogers
- From the *Department of Biomedical Engineering, Northwestern University; †Department of Internal Medicine, NorthShore University HealthSystems, Evanston; ‡Center for Endoscopic Research and Therapeutics, University of Chicago Medicine, Chicago, IL; and §Department of Gastroenterology, Boston Medical Center, Boston, MA
| | - Bradley Gould
- From the *Department of Biomedical Engineering, Northwestern University; †Department of Internal Medicine, NorthShore University HealthSystems, Evanston; ‡Center for Endoscopic Research and Therapeutics, University of Chicago Medicine, Chicago, IL; and §Department of Gastroenterology, Boston Medical Center, Boston, MA
| | - Adam Eshein
- From the *Department of Biomedical Engineering, Northwestern University; †Department of Internal Medicine, NorthShore University HealthSystems, Evanston; ‡Center for Endoscopic Research and Therapeutics, University of Chicago Medicine, Chicago, IL; and §Department of Gastroenterology, Boston Medical Center, Boston, MA
| | - Sudeep Upadhye
- From the *Department of Biomedical Engineering, Northwestern University; †Department of Internal Medicine, NorthShore University HealthSystems, Evanston; ‡Center for Endoscopic Research and Therapeutics, University of Chicago Medicine, Chicago, IL; and §Department of Gastroenterology, Boston Medical Center, Boston, MA
| | - Ann Koons
- From the *Department of Biomedical Engineering, Northwestern University; †Department of Internal Medicine, NorthShore University HealthSystems, Evanston; ‡Center for Endoscopic Research and Therapeutics, University of Chicago Medicine, Chicago, IL; and §Department of Gastroenterology, Boston Medical Center, Boston, MA
| | - Mariano Gonzalez-Haba Ruiz
- From the *Department of Biomedical Engineering, Northwestern University; †Department of Internal Medicine, NorthShore University HealthSystems, Evanston; ‡Center for Endoscopic Research and Therapeutics, University of Chicago Medicine, Chicago, IL; and §Department of Gastroenterology, Boston Medical Center, Boston, MA
| | - Hemant K. Roy
- From the *Department of Biomedical Engineering, Northwestern University; †Department of Internal Medicine, NorthShore University HealthSystems, Evanston; ‡Center for Endoscopic Research and Therapeutics, University of Chicago Medicine, Chicago, IL; and §Department of Gastroenterology, Boston Medical Center, Boston, MA
| | - Vadim Backman
- From the *Department of Biomedical Engineering, Northwestern University; †Department of Internal Medicine, NorthShore University HealthSystems, Evanston; ‡Center for Endoscopic Research and Therapeutics, University of Chicago Medicine, Chicago, IL; and §Department of Gastroenterology, Boston Medical Center, Boston, MA
| |
Collapse
|
13
|
Radosevich AJ, Mutyal NN, Eshein A, Nguyen TQ, Gould B, Rogers JD, Goldberg MJ, Bianchi LK, Yen EF, Konda V, Rex DK, Van Dam J, Backman V, Roy HK. Rectal Optical Markers for In Vivo Risk Stratification of Premalignant Colorectal Lesions. Clin Cancer Res 2015; 21:4347-4355. [PMID: 25991816 DOI: 10.1158/1078-0432.ccr-15-0136] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 05/04/2015] [Indexed: 02/06/2023]
Abstract
PURPOSE Colorectal cancer remains the second leading cause of cancer deaths in the United States despite being eminently preventable by colonoscopy via removal of premalignant adenomas. In order to more effectively reduce colorectal cancer mortality, improved screening paradigms are needed. Our group pioneered the use of low-coherence enhanced backscattering (LEBS) spectroscopy to detect the presence of adenomas throughout the colon via optical interrogation of the rectal mucosa. In a previous ex vivo biopsy study of 219 patients, LEBS demonstrated excellent diagnostic potential with 89.5% accuracy for advanced adenomas. The objective of the current cross-sectional study is to assess the viability of rectal LEBS in vivo. EXPERIMENTAL DESIGN Measurements from 619 patients were taken using a minimally invasive 3.4-mm diameter LEBS probe introduced into the rectum via anoscope or direct insertion, requiring approximately 1 minute from probe insertion to withdrawal. The diagnostic LEBS marker was formed as a logistic regression of the optical reduced scattering coefficient [Formula: see text] and mass density distribution factor D. RESULTS The rectal LEBS marker was significantly altered in patients harboring advanced adenomas and multiple non-advanced adenomas throughout the colon. Blinded and cross-validated test performance characteristics showed 88% sensitivity to advanced adenomas, 71% sensitivity to multiple non-advanced adenomas, and 72% specificity in the validation set. CONCLUSIONS We demonstrate the viability of in vivo LEBS measurement of histologically normal rectal mucosa to predict the presence of clinically relevant adenomas throughout the colon. The current work represents the next step in the development of rectal LEBS as a tool for colorectal cancer risk stratification.
Collapse
Affiliation(s)
| | - Nikhil N Mutyal
- Biomedical Engineering Department, Northwestern University, Evanston, Il
| | - Adam Eshein
- Biomedical Engineering Department, Northwestern University, Evanston, Il
| | - The-Quyen Nguyen
- Biomedical Engineering Department, Northwestern University, Evanston, Il
| | - Bradley Gould
- Biomedical Engineering Department, Northwestern University, Evanston, Il
| | - Jeremy D Rogers
- Biomedical Engineering Department, University of Wisconsin, Madison, Wisconsin
| | - Michael J Goldberg
- Department of Medicine, NorthShore University HealthSystems, Evanston, Il
| | - Laura K Bianchi
- Department of Medicine, NorthShore University HealthSystems, Evanston, Il
| | - Eugene F Yen
- Department of Medicine, NorthShore University HealthSystems, Evanston, Il
| | - Vani Konda
- Center for Endoscopic Research and Therapeutics, University of Chicago Medicine, Chicago, IL
| | - Douglas K Rex
- Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jacques Van Dam
- Advanced Digestive Health Center, University of Southern California Medical Center, Los Angeles, CA
| | - Vadim Backman
- Biomedical Engineering Department, Northwestern University, Evanston, Il
| | - Hemant K Roy
- Department of Medicine, Boston University, Boston, Massachusetts
| |
Collapse
|
14
|
Radosevich AJ, Eshein A, Nguyen TQ, Backman V. Subdiffusion reflectance spectroscopy to measure tissue ultrastructure and microvasculature: model and inverse algorithm. J Biomed Opt 2015; 20:097002. [PMID: 26414387 PMCID: PMC4963470 DOI: 10.1117/1.jbo.20.9.097002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 08/31/2015] [Indexed: 05/19/2023]
Abstract
Reflectance measurements acquired from within the subdiffusion regime (i.e., lengthscales smaller than a transport mean free path) retain much of the original information about the shape of the scattering phase function. Given this sensitivity, many models of subdiffusion regime light propagation have focused on parametrizing the optical signal through various optical and empirical parameters. We argue, however, that a more useful and universal way to characterize such measurements is to focus instead on the fundamental physical properties, which give rise to the optical signal. This work presents the methodologies that used to model and extract tissue ultrastructural and microvascular properties from spatially resolved subdiffusion reflectance spectroscopy measurements. We demonstrate this approach using ex-vivo rat tissue samples measured by enhanced backscattering spectroscopy.
Collapse
Affiliation(s)
- Andrew J. Radosevich
- Northwestern University, Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208, United States
- Address all correspondence to: Andrew J. Radosevich, E-mail:
| | - Adam Eshein
- Northwestern University, Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - The-Quyen Nguyen
- Northwestern University, Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Vadim Backman
- Northwestern University, Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| |
Collapse
|
15
|
Doronin A, Radosevich AJ, Backman V, Meglinski I. Two electric field Monte Carlo models of coherent backscattering of polarized light. J Opt Soc Am A Opt Image Sci Vis 2014; 31:2394-2400. [PMID: 25401350 DOI: 10.1364/josaa.31.002394] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Modeling of coherent polarized light propagation in turbid scattering medium by the Monte Carlo method provides an ultimate understanding of coherent effects of multiple scattering, such as enhancement of coherent backscattering and peculiarities of laser speckle formation in dynamic light scattering (DLS) and optical coherence tomography (OCT) diagnostic modalities. In this report, we consider two major ways of modeling the coherent polarized light propagation in scattering tissue-like turbid media. The first approach is based on tracking transformations of the electric field along the ray propagation. The second one is developed in analogy to the iterative procedure of the solution of the Bethe-Salpeter equation. To achieve a higher accuracy in the results and to speed up the modeling, both codes utilize the implementation of parallel computing on NVIDIA Graphics Processing Units (GPUs) with Compute Unified Device Architecture (CUDA). We compare these two approaches through simulations of the enhancement of coherent backscattering of polarized light and evaluate the accuracy of each technique with the results of a known analytical solution. The advantages and disadvantages of each computational approach and their further developments are discussed. Both codes are available online and are ready for immediate use or download.
Collapse
|
16
|
Cruz MD, Wali RK, Bianchi LK, Radosevich AJ, Crawford SE, Jepeal L, Goldberg MJ, Weinstein J, Momi N, Roy P, Calderwood AH, Backman V, Roy HK. Colonic mucosal fatty acid synthase as an early biomarker for colorectal neoplasia: modulation by obesity and gender. Cancer Epidemiol Biomarkers Prev 2014; 23:2413-21. [PMID: 25155760 DOI: 10.1158/1055-9965.epi-14-0026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND We have previously reported that colonic pericryptal microvascular blood flow is augmented in the premalignant colonic epithelium, highlighting the increased metabolic demand of the proliferative epithelium as a marker of field carcinogenesis. However, its molecular basis is unexplored. In this study, we assessed the expression of a regulator of the "lipogenic switch," fatty acid synthase (FASN), in early colon carcinogenesis for its potential biomarker utility for concurrent neoplasia. METHODS FASN expression (IHC) in the colonic epithelium from azoxymethane and polyposis in rat colon (Pirc) models of colorectal cancer was studied. FASN mRNA expression from endoscopically normal rectal mucosa was evaluated and correlated with colonoscopic findings (pathologic confirmation of neoplasia). RESULTS FASN expression progressively increased from premalignant to malignant stage in the azoxymethane model (1.9- to 2.5-fold; P < 0.0001) and was also higher in the adenomas compared with adjacent uninvolved mucosa (1.8- to 3.4-fold; P < 0.001) in the Pirc model. Furthermore, FASN was significantly overexpressed in rectal biopsies from patients harboring adenomas compared with those with no adenomas. These effects were accentuated in male (∼2-fold) and obese patients (1.4-fold compared with those with body mass index < 30). Overall, the performance of rectal FASN was excellent (AUROC of 0.81). CONCLUSIONS FASN is altered in the premalignant colonic mucosa and may serve as a marker for colonic neoplasia present elsewhere. The enhanced effects in men and obesity may have implications for identifying patient subgroups at risk for early-onset neoplasia. IMPACT These findings support the role of rectal FASN expression as a reliable biomarker of colonic neoplasia.
Collapse
Affiliation(s)
- Mart Dela Cruz
- Section of Gastroenterology, Boston University Medical Center, Boston, Massachusetts
| | - Ramesh K Wali
- Section of Gastroenterology, Boston University Medical Center, Boston, Massachusetts.
| | - Laura K Bianchi
- Department of Medicine, NorthShore University HealthSystem, Evanston, Illinois
| | - Andrew J Radosevich
- Biomedical Engineering Department, Northwestern University, Evanston, Illinois
| | - Susan E Crawford
- Department of Pathology, St. Louis University, St. Louis, Missouri
| | - Lisa Jepeal
- Section of Gastroenterology, Boston University Medical Center, Boston, Massachusetts
| | - Michael J Goldberg
- Department of Medicine, NorthShore University HealthSystem, Evanston, Illinois
| | - Jaclyn Weinstein
- Section of Gastroenterology, Boston University Medical Center, Boston, Massachusetts
| | - Navneet Momi
- Section of Gastroenterology, Boston University Medical Center, Boston, Massachusetts
| | - Priya Roy
- Section of Gastroenterology, Boston University Medical Center, Boston, Massachusetts
| | - Audrey H Calderwood
- Section of Gastroenterology, Boston University Medical Center, Boston, Massachusetts
| | - Vadim Backman
- Biomedical Engineering Department, Northwestern University, Evanston, Illinois
| | - Hemant K Roy
- Section of Gastroenterology, Boston University Medical Center, Boston, Massachusetts
| |
Collapse
|
17
|
Yi J, Radosevich AJ, Stypula-Cyrus Y, Mutyal NN, Azarin SM, Horcher E, Goldberg MJ, Bianchi LK, Bajaj S, Roy HK, Backman V. Spatially resolved optical and ultrastructural properties of colorectal and pancreatic field carcinogenesis observed by inverse spectroscopic optical coherence tomography. J Biomed Opt 2014; 19:36013. [PMID: 24643530 PMCID: PMC4019430 DOI: 10.1117/1.jbo.19.3.036013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 02/13/2014] [Accepted: 02/17/2014] [Indexed: 05/18/2023]
Abstract
Field carcinogenesis is the initial stage of cancer progression. Understanding field carcinogenesis is valuable for both cancer biology and clinical medicine. Here, we used inverse spectroscopic optical coherence tomography to study colorectal cancer (CRC) and pancreatic cancer (PC) field carcinogenesis. Depth-resolved optical and ultrastructural properties of the mucosa were quantified from histologically normal rectal biopsies from patients with and without colon adenomas (n=85) as well as from histologically normal peri-ampullary duodenal biopsies from patients with and without PC (n=22). Changes in the epithelium and stroma in CRC field carcinogenesis were separately quantified. In both compartments, optical and ultra-structural alterations were consistent. Optical alterations included lower backscattering (μb) and reduced scattering (μs') coefficients and higher anisotropy factor g. Ultrastructurally pronounced alterations were observed at length scales up to ∼450 nm, with the shape of the mass density correlation function having a higher shape factor D, thus implying a shift to larger length scales. Similar alterations were found in the PC field carcinogenesis despite the difference in genetic pathways and etiologies. We further verified that the chromatin clumping in epithelial cells and collagen cross-linking caused D to increase in vitro and could be among the mechanisms responsible for the observed changes in epithelium and stroma, respectively.
Collapse
Affiliation(s)
- Ji Yi
- Northwestern University, Department of Biomedical Engineering, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Andrew J. Radosevich
- Northwestern University, Department of Biomedical Engineering, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Yolanda Stypula-Cyrus
- Northwestern University, Department of Biomedical Engineering, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Nikhil N. Mutyal
- Northwestern University, Department of Biomedical Engineering, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Samira Michelle Azarin
- Northwestern University, Department of Biomedical Engineering, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Elizabeth Horcher
- Northwestern University, Department of Biomedical Engineering, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Michael J. Goldberg
- NorthShore University Health Systems, Department of Internal Medicine, Evanston, Illinois 60201
| | - Laura K. Bianchi
- NorthShore University Health Systems, Department of Internal Medicine, Evanston, Illinois 60201
| | - Shailesh Bajaj
- NorthShore University Health Systems, Department of Internal Medicine, Evanston, Illinois 60201
| | - Hemant K. Roy
- Boston Medical Center, Department of Medicine, Boston, Massachusetts 02118
| | - Vadim Backman
- Northwestern University, Department of Biomedical Engineering, 2145 Sheridan Road, Evanston, Illinois 60208
- Address all correspondence to: Vadim Backman, E-mail:
| |
Collapse
|
18
|
Stypula-Cyrus Y, Mutyal NN, Dela Cruz M, Kunte DP, Radosevich AJ, Wali R, Roy HK, Backman V. End-binding protein 1 (EB1) up-regulation is an early event in colorectal carcinogenesis. FEBS Lett 2014; 588:829-35. [PMID: 24492008 DOI: 10.1016/j.febslet.2014.01.046] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 01/20/2014] [Indexed: 11/19/2022]
Abstract
End-binding protein (EB1) is a microtubule protein that binds to the tumor suppressor adenomatous polyposis coli (APC). While EB1 is implicated as a potential oncogene, its role in cancer progression is unknown. Therefore, we analyzed EB1/APC expression at the earliest stages of colorectal carcinogenesis and in the uninvolved mucosa ("field effect") of human and animal tissue. We also performed siRNA-knockdown in colon cancer cell lines. EB1 is up-regulated in early and field carcinogenesis in the colon, and the cellular/nano-architectural effect of EB1 knockdown depended on the genetic context. Thus, dysregulation of EB1 is an important early event in colon carcinogenesis.
Collapse
Affiliation(s)
- Yolanda Stypula-Cyrus
- Biomedical Engineering Department, Northwestern University, Evanston, IL 60208, USA.
| | - Nikhil N Mutyal
- Biomedical Engineering Department, Northwestern University, Evanston, IL 60208, USA
| | - Mart Dela Cruz
- Department of Medicine, Boston Medical Center, Boston, MA 02118, USA
| | - Dhananjay P Kunte
- Department of Internal Medicine, NorthShore University Health System, Evanston, IL 60201, USA
| | - Andrew J Radosevich
- Biomedical Engineering Department, Northwestern University, Evanston, IL 60208, USA
| | - Ramesh Wali
- Department of Medicine, Boston Medical Center, Boston, MA 02118, USA
| | - Hemant K Roy
- Department of Medicine, Boston Medical Center, Boston, MA 02118, USA.
| | - Vadim Backman
- Biomedical Engineering Department, Northwestern University, Evanston, IL 60208, USA
| |
Collapse
|
19
|
Rogers JD, Radosevich AJ, Yi J, Backman V. Modeling Light Scattering in Tissue as Continuous Random Media Using a Versatile Refractive Index Correlation Function. IEEE J Sel Top Quantum Electron 2013; 20:7000514. [PMID: 25587211 PMCID: PMC4289622 DOI: 10.1109/jstqe.2013.2280999] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Optical interactions with biological tissue provide powerful tools for study, diagnosis, and treatment of disease. When optical methods are used in applications involving tissue, scattering of light is an important phenomenon. In imaging modalities, scattering provides contrast, but also limits imaging depth, so models help optimize an imaging technique. Scattering can also be used to collect information about the tissue itself providing diagnostic value. Therapies involving focused beams require scattering models to assess dose distribution. In all cases, models of light scattering in tissue are crucial to correctly interpreting the measured signal. Here, we review a versatile model of light scattering that uses the Whittle-Matérn correlation family to describe the refractive index correlation function Bn (rd ). In weakly scattering media such as tissue, Bn (rd ) determines the shape of the power spectral density from which all other scattering characteristics are derived. This model encompasses many forms such as mass fractal and the Henyey-Greenstein function as special cases. We discuss normalization and calculation of optical properties including the scattering coefficient and anisotropy factor. Experimental methods using the model are also described to quantify tissue properties that depend on length scales of only a few tens of nanometers.
Collapse
Affiliation(s)
- Jeremy D. Rogers
- Department of Biomedical Engineering, University of Wisconsin, Madison, WI 53706 USA
| | - Andrew J. Radosevich
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208 USA
| | - Ji Yi
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208 USA
| | - Vadim Backman
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208 USA
| |
Collapse
|
20
|
Radosevich AJ, Mutyal NN, Yi J, Stypula-Cyrus Y, Rogers JD, Goldberg MJ, Bianchi LK, Bajaj S, Roy HK, Backman V. Ultrastructural alterations in field carcinogenesis measured by enhanced backscattering spectroscopy. J Biomed Opt 2013; 18:097002. [PMID: 24008865 PMCID: PMC3764252 DOI: 10.1117/1.jbo.18.9.097002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 07/16/2013] [Accepted: 08/07/2013] [Indexed: 05/10/2023]
Abstract
Optical characterization of biological tissue in field carcinogenesis offers a method with which to study the mechanisms behind early cancer development and the potential to perform clinical diagnosis. Previously, low-coherence enhanced backscattering spectroscopy (LEBS) has demonstrated the ability to discriminate between normal and diseased organs based on measurements of histologically normal-appearing tissue in the field of colorectal (CRC) and pancreatic (PC) cancers. Here, we implement the more comprehensive enhanced backscattering (EBS) spectroscopy to better understand the structural and optical changes which lead to the previous findings. EBS provides high-resolution measurement of the spatial reflectance profile P(rs) between 30 microns and 2.7 mm, where information about nanoscale mass density fluctuations in the mucosa can be quantified. A demonstration of the length-scales at which P(rs) is optimally altered in CRC and PC field carcinogenesis is given and subsequently these changes are related to the tissue's structural composition. Three main conclusions are made. First, the most significant changes in P(rs) occur at short length-scales corresponding to the superficial mucosal layer. Second, these changes are predominantly attributable to a reduction in the presence of subdiffractional structures. Third, similar trends are seen for both cancer types, suggesting a common progression of structural alterations in each.
Collapse
Affiliation(s)
- Andrew J. Radosevich
- Northwestern University, Department of Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Nikhil N. Mutyal
- Northwestern University, Department of Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Ji Yi
- Northwestern University, Department of Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Yolanda Stypula-Cyrus
- Northwestern University, Department of Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Jeremy D. Rogers
- Northwestern University, Department of Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Michael J. Goldberg
- NorthShore University Healthsystems, Department of Internal Medicine, Evanston, Illinois 60201
| | - Laura K. Bianchi
- NorthShore University Healthsystems, Department of Internal Medicine, Evanston, Illinois 60201
| | - Shailesh Bajaj
- NorthShore University Healthsystems, Department of Internal Medicine, Evanston, Illinois 60201
| | - Hemant K. Roy
- Boston Medical Center, Department of Medicine, Boston, Massachusetts 02118
| | - Vadim Backman
- Northwestern University, Department of Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208
| |
Collapse
|
21
|
Yi J, Radosevich AJ, Rogers JD, Norris SCP, Çapoğlu İR, Taflove A, Backman V. Can OCT be sensitive to nanoscale structural alterations in biological tissue? Opt Express 2013; 21:9043-59. [PMID: 23571994 PMCID: PMC3641881 DOI: 10.1364/oe.21.009043] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 03/07/2013] [Accepted: 03/11/2013] [Indexed: 05/18/2023]
Abstract
Exploration of nanoscale tissue structures is crucial in understanding biological processes. Although novel optical microscopy methods have been developed to probe cellular features beyond the diffraction limit, nanometer-scale quantification remains still inaccessible for in situ tissue. Here we demonstrate that, without actually resolving specific geometrical feature, OCT can be sensitive to tissue structural properties at the nanometer length scale. The statistical mass-density distribution in tissue is quantified by its autocorrelation function modeled by the Whittle-Mateŕn functional family. By measuring the wavelength-dependent backscattering coefficient μb(λ) and the scattering coefficient μs, we introduce a technique called inverse spectroscopic OCT (ISOCT) to quantify the mass-density correlation function. We find that the length scale of sensitivity of ISOCT ranges from ~30 to ~450 nm. Although these sub-diffractional length scales are below the spatial resolution of OCT and therefore not resolvable, they are nonetheless detectable. The sub-diffractional sensitivity is validated by 1) numerical simulations; 2) tissue phantom studies; and 3) ex vivo colon tissue measurements cross-validated by scanning electron microscopy (SEM). Finally, the 3D imaging capability of ISOCT is demonstrated with ex vivo rat buccal and human colon samples.
Collapse
Affiliation(s)
- Ji Yi
- Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Rd.,Evanston, IL 60208, USA.
| | | | | | | | | | | | | |
Collapse
|
22
|
Radosevich AJ, Yi J, Rogers JD, Backman V. Structural length-scale sensitivities of reflectance measurements in continuous random media under the Born approximation. Opt Lett 2012; 37:5220-2. [PMID: 23258058 PMCID: PMC3655697 DOI: 10.1364/ol.37.005220] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Which range of structures contributes to light scattering in a continuous random media, such as biological tissue? In this Letter, we present a model to study the structural length-scale sensitivity of scattering in continuous random media under the Born approximation. The scattering coefficient μs, backscattering coefficient μb, anisotropy factor g, and reduced scattering coefficient μs* as well as the shape of the spatial reflectance profile are calculated under this model. For media with a biologically relevant Henyey-Greenstein phase function with g∼0.93 at wavelength λ=633 nm, we report that μs* is sensitive to structural length-scales from 46.9 nm to 2.07 μm (i.e., λ/13 to 3λ), μb is sensitive from 26.7 to 320 nm (i.e., λ/24 to λ/2), and the spatial reflectance profile is sensitive from 30.8 nm to 2.71 μm (i.e., λ/21 to 4λ).
Collapse
Affiliation(s)
- Andrew J Radosevich
- Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA.
| | | | | | | |
Collapse
|
23
|
Radosevich AJ, Rogers JD, Capoğlu IR, Mutyal NN, Pradhan P, Backman V. Open source software for electric field Monte Carlo simulation of coherent backscattering in biological media containing birefringence. J Biomed Opt 2012; 17:115001. [PMID: 23123973 PMCID: PMC3487050 DOI: 10.1117/1.jbo.17.11.115001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
ABSTRACT. We present an open source electric field tracking Monte Carlo program to model backscattering in biological media containing birefringence, with computation of the coherent backscattering phenomenon as an example. These simulations enable the modeling of tissue scattering as a statistically homogeneous continuous random media under the Whittle-Matérn model, which includes the Henyey-Greenstein phase function as a special case, or as a composition of discrete spherical scatterers under Mie theory. The calculation of the amplitude scattering matrix for the above two cases as well as the implementation of birefringence using the Jones N-matrix formalism is presented. For ease of operator use and data processing, our simulation incorporates a graphical user interface written in MATLAB to interact with the underlying C code. Additionally, an increase in computational speed is achieved through implementation of message passing interface and the semi-analytical approach. Finally, we provide demonstrations of the results of our simulation for purely scattering media and scattering media containing linear birefringence.
Collapse
Affiliation(s)
- Andrew J Radosevich
- Northwestern University, Biomedical Engineering Department, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208, USA.
| | | | | | | | | | | |
Collapse
|
24
|
Radosevich AJ, Rogers JD, Turzhitsky V, Mutyal NN, Yi J, Roy HK, Backman V. Polarized Enhanced Backscattering Spectroscopy for Characterization of Biological Tissues at Subdiffusion Length-scales. IEEE J Sel Top Quantum Electron 2012; 18:1313-1325. [PMID: 24163574 PMCID: PMC3806115 DOI: 10.1109/jstqe.2011.2173659] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Since the early 1980's, the enhanced backscattering (EBS) phenomenon has been well-studied in a large variety of non-biological materials. Yet, until recently the use of conventional EBS for the characterization of biological tissue has been fairly limited. In this work we detail the unique ability of EBS to provide spectroscopic, polarimetric, and depth-resolved characterization of biological tissue using a simple backscattering instrument. We first explain the experimental and numerical procedures used to accurately measure and model the full azimuthal EBS peak shape in biological tissue. Next we explore the peak shape and height dependencies for different polarization channels and spatial coherence of illumination. We then illustrate the extraordinary sensitivity of EBS to the shape of the scattering phase function using suspensions of latex microspheres. Finally, we apply EBS to biological tissue samples in order to measure optical properties and observe the spatial length-scales at which backscattering is altered in early colon carcinogenesis.
Collapse
Affiliation(s)
- Andrew J Radosevich
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208 USA
| | | | | | | | | | | | | |
Collapse
|
25
|
Radosevich AJ, Mutyal NN, Turzhitsky V, Rogers JD, Yi J, Taflove A, Backman V. Measurement of the spatial backscattering impulse-response at short length scales with polarized enhanced backscattering. Opt Lett 2011; 36:4737-9. [PMID: 22179867 PMCID: PMC3355761 DOI: 10.1364/ol.36.004737] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
In this Letter, we describe an easy to implement technique to measure the spatial backscattering impulse-response at length scales shorter than a transport mean free path with resolution of better than 10 μm using the enhanced backscattering phenomenon. This technique enables spectroscopic measurements throughout the visible range and sensitivity to all polarization channels. Through a combination of Monte Carlo simulations and experimental measurements of latex microspheres, we explore the various sensitivities of our technique to both intrinsic sample properties and extrinsic instrumental properties. We conclude by demonstrating the extraordinary sensitivity of our technique to the shape of the scattering phase function, including higher order shape parameters than the anisotropy factor (or first moment).
Collapse
Affiliation(s)
- Andrew J Radosevich
- Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA.
| | | | | | | | | | | | | |
Collapse
|
26
|
Turzhitsky V, Mutyal NN, Radosevich AJ, Backman V. Multiple scattering model for the penetration depth of low-coherence enhanced backscattering. J Biomed Opt 2011; 16:097006. [PMID: 21950941 PMCID: PMC3188644 DOI: 10.1117/1.3625402] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 07/20/2011] [Accepted: 07/21/2011] [Indexed: 05/24/2023]
Abstract
Low-coherence enhanced backscattering (LEBS) is a depth-selective self-interference phenomenon that originates from light traveling time-reversed paths in a scattering medium. The depth selectivity of LEBS and its sensitivity to optical properties of the scattering medium has made it a promising technique for probing the structure of biological tissue with applications to disease diagnosis and, in particular, precancerous conditions. The ability to accurately predict the penetration depth of the LEBS signal is important in targeting an optimal tissue depth for detecting precancerous cells. This prediction is further complicated by the variation in optical properties of different tissue types. In this paper, the effects of the reduced scattering coefficient (μ(s)'), the phase function and the instrument spatial coherence length (L(sc)) on the LEBS penetration depth are quantified. It is determined that the LEBS penetration depth is primarily dependent on L(sc), μ(s)', and the anisotropy factor (g), but has minimal dependence on higher moments of the phase function. An empirical expression, having a similar form as the double scattering approximation for LEBS, is found to accurately predict the average penetration depth in the multiple scattering regime. The expression is shown to be accurate for a broad range of experimentally relevant optical properties and spatial coherence lengths.
Collapse
Affiliation(s)
- Vladimir Turzhitsky
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois 60208, USA.
| | | | | | | |
Collapse
|
27
|
Turzhitsky V, Radosevich AJ, Rogers JD, Mutyal NN, Backman V. Measurement of optical scattering properties with low-coherence enhanced backscattering spectroscopy. J Biomed Opt 2011; 16:067007. [PMID: 21721828 PMCID: PMC3138801 DOI: 10.1117/1.3589349] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Low-coherence enhanced backscattering (LEBS) is a depth selective technique that allows noninvasive characterization of turbid media such as biological tissue. LEBS provides a spectral measurement of the tissue reflectance distribution as a function of distance between incident and reflected ray pairs through the use of partial spatial coherence broadband illumination. We present LEBS as a new depth-selective technique to measure optical properties of tissue in situ. Because LEBS enables measurements of reflectance due to initial scattering events, LEBS is sensitive to the shape of the phase function in addition to the reduced scattering coefficient (μ(s) (*)). We introduce a simulation of LEBS that implements a two parameter phase function based on the Whittle-Matérn refractive index correlation function model. We show that the LEBS enhancement factor (E) primarily depends on μ(s) (*), the normalized spectral dependence of E (S(n)) depends on one of the two parameters of the phase function that also defines the functional type of the refractive index correlation function (m), and the LEBS peak width depends on both the anisotropy factor (g) and m. Three inverse models for calculating these optical properties are described and the calculations are validated with an experimental measurement from a tissue phantom.
Collapse
Affiliation(s)
- Vladimir Turzhitsky
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois 60208, USA.
| | | | | | | | | |
Collapse
|
28
|
Grosberg LE, Radosevich AJ, Asfaha S, Wang TC, Hillman EMC. Spectral characterization and unmixing of intrinsic contrast in intact normal and diseased gastric tissues using hyperspectral two-photon microscopy. PLoS One 2011; 6:e19925. [PMID: 21603623 PMCID: PMC3095627 DOI: 10.1371/journal.pone.0019925] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 04/21/2011] [Indexed: 11/18/2022] Open
Abstract
Background Living tissues contain a range of intrinsic fluorophores and sources of second harmonic generation which provide contrast that can be exploited for fresh tissue imaging. Microscopic imaging of fresh tissue samples can circumvent the cost and time associated with conventional histology. Further, intrinsic contrast can provide rich information about a tissue's composition, structure and function, and opens the potential for in-vivo imaging without the need for contrast agents. Methodology/Principal Findings In this study, we used hyperspectral two-photon microscopy to explore the characteristics of both normal and diseased gastrointestinal (GI) tissues, relying only on their endogenous fluorescence and second harmonic generation to provide contrast. We obtained hyperspectral data at subcellular resolution by acquiring images over a range of two-photon excitation wavelengths, and found excitation spectral signatures of specific tissue types based on our ability to clearly visualize morphology. We present the two-photon excitation spectral properties of four major tissue types that are present throughout the GI tract: epithelium, lamina propria, collagen, and lymphatic tissue. Using these four excitation signatures as basis spectra, linear unmixing strategies were applied to hyperspectral data sets of both normal and neoplastic tissue acquired in the colon and small intestine. Our results show that hyperspectral unmixing with excitation spectra allows segmentation, showing promise for blind identification of tissue types within a field of view, analogous to specific staining in conventional histology. The intrinsic spectral signatures of these tissue types provide information relating to their biochemical composition. Conclusions/Significance These results suggest hyperspectral two-photon microscopy could provide an alternative to conventional histology either for in-situ imaging, or intraoperative ‘instant histology’ of fresh tissue biopsies.
Collapse
Affiliation(s)
- Lauren E Grosberg
- Laboratory for Functional Optical Imaging, Department of Biomedical Engineering, Columbia University, New York, New York, United States of America.
| | | | | | | | | |
Collapse
|
29
|
Radosevich AJ, Turzhitsky VM, Mutyal NN, Rogers JD, Stoyneva V, Tiwari AK, De La Cruz M, Kunte DP, Wali RK, Roy HK, Backman V. Depth-resolved measurement of mucosal microvascular blood content using
low-coherence enhanced backscattering spectroscopy. Biomed Opt Express 2010; 1:1196-1208. [PMID: 21258541 PMCID: PMC3018078 DOI: 10.1364/boe.1.001196] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 10/10/2010] [Accepted: 10/17/2010] [Indexed: 05/04/2023]
Abstract
Low-coherence enhanced backscattering (LEBS) spectroscopy is a light scattering technique which uses partial spatial coherence broadband illumination to interrogate the optical properties at sub-diffusion length scales. In this work, we present a post-processing technique which isolates the hemoglobin concentration at different depths within a sample using a single spectroscopic LEBS measurement with a fixed spatial coherence of illumination. We verify the method with scattering (spectralon reflectance standard and polystyrene microspheres) and absorbing (hemoglobin) phantoms. We then demonstrate the relevance of this method for quantifying hemoglobin content as a function of depth within biological tissue using the azoxymethane treated animal model of colorectal cancer.
Collapse
Affiliation(s)
- Andrew J. Radosevich
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Vladimir M. Turzhitsky
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Nikhil N. Mutyal
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Jeremy D. Rogers
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Valentina Stoyneva
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Ashish Kumar Tiwari
- Department of Gastroenterology, Northshore University Healthsystems, Evanston, Illinois 60201, USA
| | - Mart De La Cruz
- Department of Gastroenterology, Northshore University Healthsystems, Evanston, Illinois 60201, USA
| | - Dhananjay P. Kunte
- Department of Gastroenterology, Northshore University Healthsystems, Evanston, Illinois 60201, USA
| | - Ramesh K. Wali
- Department of Gastroenterology, Northshore University Healthsystems, Evanston, Illinois 60201, USA
| | - Hemant K. Roy
- Department of Gastroenterology, Northshore University Healthsystems, Evanston, Illinois 60201, USA
| | - Vadim Backman
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| |
Collapse
|
30
|
Abstract
In vivo two-photon imaging of intrinsic contrast can provide valuable information about structural tissue elements such as collagen and elastin and fluorescent metabolites such as nicotinamide adenine dinucleotide. Yet low signal and overlapping emission spectra can make it difficult to identify and delineate these species in vivo. We present a novel approach that combines excitation scanning with spectrally resolved emission two-photon microscopy, allowing distinct structures to be delineated based on their characteristic spectral fingerprints. The amounts of intrinsic fluorophores present in each voxel can also be evaluated. We demonstrate our method using in vivo imaging of nude mouse skin.
Collapse
|