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Alcala-Zermeno JL, Fureman B, Grzeskowiak CL, Potnis O, Taveras M, Logan MW, Rybacki D, Friedman D, Lowenstein D, Kuzniecky R, French J. Racial disparities in the utilization of invasive neuromodulation devices for the treatment of drug-resistant focal epilepsy. Epilepsia 2024; 65:e61-e66. [PMID: 38506370 DOI: 10.1111/epi.17961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 03/09/2024] [Accepted: 03/11/2024] [Indexed: 03/21/2024]
Abstract
Racial disparities affect multiple dimensions of epilepsy care including epilepsy surgery. This study aims to further explore these disparities by determining the utilization of invasive neuromodulation devices according to race and ethnicity in a multicenter study of patients living with focal drug-resistant epilepsy (DRE). We performed a post hoc analysis of the Human Epilepsy Project 2 (HEP2) data. HEP2 is a prospective study of patients living with focal DRE involving 10 sites distributed across the United States. There were no statistical differences in the racial distribution of the study population compared to the US population using census data except for patients reporting more than one race. Of 154 patients enrolled in HEP2, 55 (36%) underwent invasive neuromodulation for DRE management at some point in the course of their epilepsy. Of those, 36 (71%) were patients who identified as White. Patients were significantly less likely to have a device if they identified solely as Black/African American than if they did not (odds ratio = .21, 95% confidence interval = .05-.96, p = .03). Invasive neuromodulation for management of DRE is underutilized in the Black/African American population, indicating a new facet of racial disparities in epilepsy care.
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Affiliation(s)
- Juan Luis Alcala-Zermeno
- Department of Neurology, Jefferson Comprehensive Epilepsy Center, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | - Brandy Fureman
- Research and New Therapies, Epilepsy Foundation, Bowie, Maryland, USA
| | | | - Ojas Potnis
- Research and New Therapies, Epilepsy Foundation, Bowie, Maryland, USA
| | - Maria Taveras
- Department of Neurology, Comprehensive Epilepsy Center, NYU Langone Health, New York, New York, USA
| | - Margaret W Logan
- Research and New Therapies, Epilepsy Foundation, Bowie, Maryland, USA
| | - Delanie Rybacki
- Research and New Therapies, Epilepsy Foundation, Bowie, Maryland, USA
| | - Daniel Friedman
- Department of Neurology, Comprehensive Epilepsy Center, NYU Langone Health, New York, New York, USA
| | - Daniel Lowenstein
- Department of Neurology, University of California, San Francisco, San Francisco, California, USA
| | - Ruben Kuzniecky
- Department of Neurology, Zucker Hofstra School of Medicine, Northwell Health, New York, New York, USA
| | - Jacqueline French
- Research and New Therapies, Epilepsy Foundation, Bowie, Maryland, USA
- Department of Neurology, Comprehensive Epilepsy Center, NYU Langone Health, New York, New York, USA
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2
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Shuryak I, Nemzow L, Bacon BA, Taveras M, Wu X, Deoli N, Ponnaiya B, Garty G, Brenner DJ, Turner HC. Machine learning approach for quantitative biodosimetry of partial-body or total-body radiation exposures by combining radiation-responsive biomarkers. Sci Rep 2023; 13:949. [PMID: 36653416 PMCID: PMC9849198 DOI: 10.1038/s41598-023-28130-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 01/13/2023] [Indexed: 01/19/2023] Open
Abstract
During a large-scale radiological event such as an improvised nuclear device detonation, many survivors will be shielded from radiation by environmental objects, and experience only partial-body irradiation (PBI), which has different consequences, compared with total-body irradiation (TBI). In this study, we tested the hypothesis that applying machine learning to a combination of radiation-responsive biomarkers (ACTN1, DDB2, FDXR) and B and T cell counts will quantify and distinguish between PBI and TBI exposures. Adult C57BL/6 mice of both sexes were exposed to 0, 2.0-2.5 or 5.0 Gy of half-body PBI or TBI. The random forest (RF) algorithm trained on ½ of the data reconstructed the radiation dose on the remaining testing portion of the data with mean absolute error of 0.749 Gy and reconstructed the product of dose and exposure status (defined as 1.0 × Dose for TBI and 0.5 × Dose for PBI) with MAE of 0.472 Gy. Among irradiated samples, PBI could be distinguished from TBI: ROC curve AUC = 0.944 (95% CI: 0.844-1.0). Mouse sex did not significantly affect dose reconstruction. These results support the hypothesis that combinations of protein biomarkers and blood cell counts can complement existing methods for biodosimetry of PBI and TBI exposures.
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Affiliation(s)
- Igor Shuryak
- Center for Radiological Research, Columbia University Irving Medical Center, 630 West 168th street, VC-11-234/5, New York, NY, 10032, USA.
| | - Leah Nemzow
- Center for Radiological Research, Columbia University Irving Medical Center, 630 West 168th street, VC-11-234/5, New York, NY, 10032, USA
| | - Bezalel A Bacon
- Center for Radiological Research, Columbia University Irving Medical Center, 630 West 168th street, VC-11-234/5, New York, NY, 10032, USA
| | - Maria Taveras
- Center for Radiological Research, Columbia University Irving Medical Center, 630 West 168th street, VC-11-234/5, New York, NY, 10032, USA
| | - Xuefeng Wu
- Center for Radiological Research, Columbia University Irving Medical Center, 630 West 168th street, VC-11-234/5, New York, NY, 10032, USA
| | - Naresh Deoli
- Radiological Research Accelerator Facility, Columbia University Irving Medical Center, Irvington, NY, USA
| | - Brian Ponnaiya
- Radiological Research Accelerator Facility, Columbia University Irving Medical Center, Irvington, NY, USA
| | - Guy Garty
- Radiological Research Accelerator Facility, Columbia University Irving Medical Center, Irvington, NY, USA
| | - David J Brenner
- Center for Radiological Research, Columbia University Irving Medical Center, 630 West 168th street, VC-11-234/5, New York, NY, 10032, USA
| | - Helen C Turner
- Center for Radiological Research, Columbia University Irving Medical Center, 630 West 168th street, VC-11-234/5, New York, NY, 10032, USA
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3
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Capaccio C, Perrier JR, Cunha L, Mahnke RC, Lörch T, Porter M, Smith CL, Damer K, Bourland JD, Frizzell B, Torelli J, Vasquez M, Brower JB, Doyle-Eisele M, Taveras M, Turner H, Brenner DJ, Kowalski R. CytoRADx: A High-Throughput, Standardized Biodosimetry Diagnostic System Based on the Cytokinesis-Block Micronucleus Assay. Radiat Res 2021; 196:523-534. [PMID: 34515768 DOI: 10.1667/rade-20-00030.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 08/26/2021] [Indexed: 11/03/2022]
Abstract
In a large-scale catastrophe, such as a nuclear detonation in a major city, it will be crucial to accurately diagnose large numbers of people to direct scarce medical resources to those in greatest need. Currently no FDA-cleared tests are available to diagnose radiation exposures, which can lead to complex, life-threatening injuries. To address this gap, we have achieved substantial advancements in radiation biodosimetry through refinement and adaptation of the cytokinesis-block micronucleus (CBMN) assay as a high throughput, quantitative diagnostic test. The classical CBMN approach, which quantifies micronuclei (MN) resulting from DNA damage, suffers from considerable time and expert labor requirements, in addition to a lack of universal methodology across laboratories. We have developed the CytoRADx™ System to address these drawbacks by implementing a standardized reagent kit, optimized assay protocol, fully automated microscopy and image analysis, and integrated dose prediction. These enhancements allow the CytoRADx System to obtain high-throughput, standardized results without specialized labor or laboratory-specific calibration curves. The CytoRADx System has been optimized for use with both humans and non-human primates (NHP) to quantify radiation dose-dependent formation of micronuclei in lymphocytes, observed using whole blood samples. Cell nuclei and resulting MN are fluorescently stained and preserved on durable microscope slides using materials provided in the kit. Up to 1,000 slides per day are subsequently scanned using the commercially based RADxScan™ Imager with customized software, which automatically quantifies the cellular features and calculates the radiation dose. Using less than 1 mL of blood, irradiated ex vivo, our system has demonstrated accurate and precise measurement of exposures from 0 to 8 Gy (90% of results within 1 Gy of delivered dose). These results were obtained from 636 human samples (24 distinct donors) and 445 NHP samples (30 distinct subjects). The system demonstrated comparable results during in vivo studies, including an investigation of 43 NHPs receiving single-dose total-body irradiation. System performance is repeatable across laboratories, operators, and instruments. Results are also statistically similar across diverse populations, considering various demographics, common medications, medical conditions, and acute injuries associated with radiological disasters. Dose calculations are stable over time as well, providing reproducible results for at least 28 days postirradiation, and for blood specimens collected and stored at room temperature for at least 72 h. The CytoRADx System provides significant advancements in the field of biodosimetry that will enable accurate diagnoses across diverse populations in large-scale emergency scenarios. In addition, our technological enhancements to the well-established CBMN assay provide a pathway for future diagnostic applications, such as toxicology and oncology.
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Affiliation(s)
| | - Jay R Perrier
- ASELL, LLC, Owings Mills, Maryland.,Columbia University, Center for Radiological Research, New York, New York
| | - Lídia Cunha
- Columbia University, Center for Radiological Research, New York, New York
| | | | | | | | | | | | - J Daniel Bourland
- Wake Forest School of Medicine, Departments of Radiation Oncology, Physics, and Biomedical Engineering, Winston-Salem, North Carolina
| | - Bart Frizzell
- Wake Forest School of Medicine, Departments of Radiation Oncology, Physics, and Biomedical Engineering, Winston-Salem, North Carolina
| | | | | | - Jeremy B Brower
- Lovelace Biomedical Research Institute, Albuquerque, New Mexico
| | | | - Maria Taveras
- Columbia University, Center for Radiological Research, New York, New York
| | - Helen Turner
- Columbia University, Center for Radiological Research, New York, New York
| | - David J Brenner
- Columbia University, Center for Radiological Research, New York, New York
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4
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Fauvel D, Taveras M, Skendelas J, Bartash R, Nnani D, Oviedo J, Forest S, Uehara M, Patel S, Goldstein D, Jorde U. The Pressure is on: Single Center's Experience with Negative Pressure Wound Therapy and Driveline Infection. J Heart Lung Transplant 2021. [DOI: 10.1016/j.healun.2021.01.1171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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5
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Rivas-Lasarte M, Wan N, Fauvel D, Taveras M, Vukelic S, Saeed O, Jorde U, Sims D. Lung Ultrasound in Left Ventricular Assist Device Patients: A Feasibility Study. J Heart Lung Transplant 2021. [DOI: 10.1016/j.healun.2021.01.1133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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6
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Phan D, Goldstein D, Chauhan D, Skendelas J, Puius Y, Fauvel D, Taveras M, Forest S. Driveline Infection: Reroute or Not to Reroute, That is the Question. J Heart Lung Transplant 2021. [DOI: 10.1016/j.healun.2021.01.1265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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7
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Wang Q, Lee Y, Shuryak I, Pujol Canadell M, Taveras M, Perrier JR, Bacon BA, Rodrigues MA, Kowalski R, Capaccio C, Brenner DJ, Turner HC. Development of the FAST-DOSE assay system for high-throughput biodosimetry and radiation triage. Sci Rep 2020; 10:12716. [PMID: 32728041 PMCID: PMC7392759 DOI: 10.1038/s41598-020-69460-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [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: 05/02/2020] [Accepted: 07/09/2020] [Indexed: 11/09/2022] Open
Abstract
Following a large-scale radiological incident, there is a need for FDA-approved biodosimetry devices and biomarkers with the ability to rapidly determine past radiation exposure with sufficient accuracy for early population triage and medical management. Towards this goal, we have developed FAST-DOSE (Fluorescent Automated Screening Tool for Dosimetry), an immunofluorescent, biomarker-based system designed to reconstruct absorbed radiation dose in peripheral blood samples collected from potentially exposed individuals. The objective of this study was to examine the performance of the FAST-DOSE assay system to quantify intracellular protein changes in blood leukocytes for early biodosimetry triage from humanized NOD-scid-gamma (Hu-NSG) mice and non-human primates (NHPs) exposed to ionizing radiation up to 8 days after radiation exposure. In the Hu-NSG mice studies, the FAST-DOSE biomarker panel was able to generate delivered dose estimates at days 1, 2 and 3 post exposure, whereas in the NHP studies, the biomarker panel was able to successfully classify samples by dose categories below or above 2 Gy up to 8 days after total body exposure. These results suggest that the FAST-DOSE bioassay has large potential as a useful diagnostic tool for rapid and reliable screening of potentially exposed individuals to aid early triage decisions within the first week post-exposure.
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Affiliation(s)
- Qi Wang
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA.
- Radiation Oncology, Columbia University Irving Medical Center, New York, NY, 10032, USA.
| | - Younghyun Lee
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Igor Shuryak
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Monica Pujol Canadell
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Maria Taveras
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Jay R Perrier
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
- ASELL, LLC, Owings Mills, MD, 21117, USA
| | - Bezalel A Bacon
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | | | | | | | - David J Brenner
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Helen C Turner
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA.
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8
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Fauvel D, Castillo C, Taveras M, Oviedo J, Saeed O, Forest S, Goldstein D, Patel S, Jorde U. Advances in Driveline Technology Cures Some but Infects Others: Single Center's Experience with Driveline Infections in HeartMate 3 Patients. J Heart Lung Transplant 2020. [DOI: 10.1016/j.healun.2020.01.827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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9
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Wang Q, Pujol-Canadell M, Taveras M, Garty G, Perrier J, Bueno-Beti C, Shuryak I, Brenner DJ, Turner HC. DNA damage response in peripheral mouse blood leukocytes in vivo after variable, low-dose rate exposure. Radiat Environ Biophys 2020; 59:89-98. [PMID: 31897603 PMCID: PMC7441378 DOI: 10.1007/s00411-019-00825-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 12/08/2019] [Indexed: 05/03/2023]
Abstract
Environmental contamination and ingestion of the radionuclide Cesium-137 (137Cs) is a large concern in fallout from a nuclear reactor accident or improvised nuclear device, and highlights the need to develop biological assays for low-dose rate, internal emitter radiation. To mimic low-dose rates attributable to fallout, we have developed a VAriable Dose-rate External 137Cs irradiatoR (VADER), which can provide arbitrarily varying and progressive low-dose rate irradiations in the range of 0.1-1.2 Gy/day, while circumventing the complexities of dealing with radioactively contaminated biomaterials. We investigated the kinetics of mouse peripheral leukocytes DNA damage response in vivo after variable, low-dose rate 137Cs exposure. C57BL/6 mice were placed in the VADER over 7 days with total accumulated dose up to 2.7 Gy. Peripheral blood response including the leukocyte depletion, apoptosis as well as its signal protein p53 and DNA repair biomarker γ-H2AX was measured. The results illustrated that blood leukocyte numbers had significantly dropped by day 7. P53 levels peaked at day 2 (total dose = 0.91 Gy) and then declined; whereas, γ-H2AX fluorescence intensity (MFI) and foci number generally increased with accumulated dose and peaked at day 5 (total dose = 2.08 Gy). ROC curve analysis for γ-H2AX provided a good discrimination of accumulated dose < 2 Gy and ≥ 2 Gy, highlighting the potential of γ-H2AX MFI as a biomarker for dosimetry in a protracted, environmental exposure scenario.
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Affiliation(s)
- Qi Wang
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA.
| | - Monica Pujol-Canadell
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Maria Taveras
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Guy Garty
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Jay Perrier
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Carlos Bueno-Beti
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Igor Shuryak
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - David J Brenner
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Helen C Turner
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, 10032, USA
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10
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Shuryak I, Turner HC, Perrier JR, Cunha L, Canadell MP, Durrani MH, Harken A, Bertucci A, Taveras M, Garty G, Brenner DJ. A High Throughput Approach to Reconstruct Partial-Body and Neutron Radiation Exposures on an Individual Basis. Sci Rep 2020; 10:2899. [PMID: 32076014 PMCID: PMC7031285 DOI: 10.1038/s41598-020-59695-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 01/27/2020] [Indexed: 11/28/2022] Open
Abstract
Biodosimetry-based individualized reconstruction of complex irradiation scenarios (partial-body shielding and/or neutron + photon mixtures) can improve treatment decisions after mass-casualty radiation-related incidents. We used a high-throughput micronucleus assay with automated scanning and imaging software on ex-vivo irradiated human lymphocytes to: a) reconstruct partial-body and/or neutron exposure, and b) estimate separately the photon and neutron doses in a mixed exposure. The mechanistic background is that, compared with total-body photon irradiations, neutrons produce more heavily-damaged lymphocytes with multiple micronuclei/binucleated cell, whereas partial-body exposures produce fewer such lymphocytes. To utilize these differences for biodosimetry, we developed metrics that describe micronuclei distributions in binucleated cells and serve as predictors in machine learning or parametric analyses of the following scenarios: (A) Homogeneous gamma-irradiation, mimicking total-body exposures, vs. mixtures of irradiated blood with unirradiated blood, mimicking partial-body exposures. (B) X rays vs. various neutron + photon mixtures. The results showed high accuracies of scenario and dose reconstructions. Specifically, receiver operating characteristic curve areas (AUC) for sample classification by exposure type reached 0.931 and 0.916 in scenarios A and B, respectively. R2 for actual vs. reconstructed doses in these scenarios reached 0.87 and 0.77, respectively. These encouraging findings demonstrate a proof-of-principle for the proposed approach of high-throughput reconstruction of clinically-relevant complex radiation exposure scenarios.
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Affiliation(s)
- Igor Shuryak
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, USA.
| | - Helen C Turner
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, USA
| | - Jay R Perrier
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, USA
| | - Lydia Cunha
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, USA
| | - Monica Pujol Canadell
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, USA
| | - Mohammad H Durrani
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, USA
| | - Andrew Harken
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, USA
| | - Antonella Bertucci
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, USA
| | - Maria Taveras
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, USA
| | - Guy Garty
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, USA
| | - David J Brenner
- Center for Radiological Research, Columbia University Irving Medical Center, New York, NY, USA
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Alvarez Villela M, Chinnadurai T, Salkey K, Furlani A, Yanamandala M, Luke A, Castillo C, Taveras M, Sims D, Saeed O, Shin J, Pina I, Jorde U, Patel S. High-Intensity Interval Training Improves Exercise Performance in Patients with LVAD. J Heart Lung Transplant 2018. [DOI: 10.1016/j.healun.2018.01.283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
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12
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Luke A, Castillo C, Taveras M, Chinnadurai T, Rangasamy S, Goldstein D, Jorde U, Patel S. IPADS and LVADS: VAD Coordinator Telemonitoring. J Heart Lung Transplant 2018. [DOI: 10.1016/j.healun.2018.01.072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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13
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Garty G, Turner HC, Salerno A, Bertucci A, Zhang J, Chen Y, Dutta A, Sharma P, Bian D, Taveras M, Wang H, Bhatla A, Balajee A, Bigelow AW, Repin M, Lyulko OV, Simaan N, Yao YL, Brenner DJ. THE DECADE OF THE RABiT (2005-15). Radiat Prot Dosimetry 2016; 172:201-206. [PMID: 27412510 PMCID: PMC5225976 DOI: 10.1093/rpd/ncw172] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The RABiT (Rapid Automated Biodosimetry Tool) is a dedicated Robotic platform for the automation of cytogenetics-based biodosimetry assays. The RABiT was developed to fulfill the critical requirement for triage following a mass radiological or nuclear event. Starting from well-characterized and accepted assays we developed a custom robotic platform to automate them. We present here a brief historical overview of the RABiT program at Columbia University from its inception in 2005 until the RABiT was dismantled at the end of 2015. The main focus of this paper is to demonstrate how the biological assays drove development of the custom robotic systems and in turn new advances in commercial robotic platforms inspired small modifications in the assays to allow replacing customized robotics with 'off the shelf' systems. Currently, a second-generation, RABiT II, system at Columbia University, consisting of a PerkinElmer cell::explorer, was programmed to perform the RABiT assays and is undergoing testing and optimization studies.
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Affiliation(s)
- G Garty
- Center for Radiological Research, Columbia University, VC11-230, 630 West 168th Street, New York, NY 10032, USA
| | - H C Turner
- Center for Radiological Research, Columbia University, VC11-230, 630 West 168th Street, New York, NY 10032, USA
| | - A Salerno
- Department of Mechanical Engineering, Columbia University, 500 West 120th Street, New York, NY 10027, USA
- Present address: Pratt & Whitney Canada Corp., 1000 Marie-Victorin, Longueil, QC, Canada J4G 1A1
| | - A Bertucci
- Center for Radiological Research, Columbia University, VC11-230, 630 West 168th Street, New York, NY 10032, USA
| | - J Zhang
- Department of Mechanical Engineering, Columbia University, 500 West 120th Street, New York, NY 10027, USA
- Present address: Auris Surgical Robotics Inc., 125 Shoreway Rd, San Carlos, CA 94070, USA
| | - Y Chen
- Department of Mechanical Engineering, Columbia University, 500 West 120th Street, New York, NY 10027, USA
| | - A Dutta
- Center for Radiological Research, Columbia University, VC11-230, 630 West 168th Street, New York, NY 10032, USA
- Present address: BioReliance Corp., 9630 Medical Center Dr, Rockville, MD 20850, USA
| | - P Sharma
- Center for Radiological Research, Columbia University, VC11-230, 630 West 168th Street, New York, NY 10032, USA
| | - D Bian
- Department of Mechanical Engineering, Columbia University, 500 West 120th Street, New York, NY 10027, USA
| | - M Taveras
- Center for Radiological Research, Columbia University, VC11-230, 630 West 168th Street, New York, NY 10032, USA
| | - H Wang
- Department of Mechanical Engineering, Columbia University, 500 West 120th Street, New York, NY 10027, USA
- Present address: General Motors Co., 30500 Mound Road, Warren, MI 48090, USA
| | - A Bhatla
- Department of Mechanical Engineering, Columbia University, 500 West 120th Street, New York, NY 10027, USA
- Present address: Curiosity Lab Inc., 54 Mallard Pl. Secaucus, NJ, 07094, USA
| | - A Balajee
- Center for Radiological Research, Columbia University, VC11-230, 630 West 168th Street, New York, NY 10032, USA
- Present address: Cytogenetic Biodosimetry Laboratory, Radiation Emergency Assistance Center and Training Site, Oak Ridge Institute for Science and Education, Oak Ridge Associated Universities, Building SC-10, 1299, Bethel Valley Road, Oak Ridge, TN, 37830, USA
| | - A W Bigelow
- Center for Radiological Research, Columbia University, VC11-230, 630 West 168th Street, New York, NY 10032, USA
| | - M Repin
- Center for Radiological Research, Columbia University, VC11-230, 630 West 168th Street, New York, NY 10032, USA
| | - O V Lyulko
- Center for Radiological Research, Columbia University, VC11-230, 630 West 168th Street, New York, NY 10032, USA
| | - N Simaan
- Department of Mechanical Engineering, Columbia University, 500 West 120th Street, New York, NY 10027, USA
- Present address: Department of Mechanical Engineering, Vanderbuilt University, PMB 351592, Nashville, TN, 37235, USA
| | - Y L Yao
- Department of Mechanical Engineering, Columbia University, 500 West 120th Street, New York, NY 10027, USA
| | - D J Brenner
- Center for Radiological Research, Columbia University, VC11-230, 630 West 168th Street, New York, NY 10032, USA
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Garty G, Bigelow AW, Repin M, Turner HC, Bian D, Balajee AS, Lyulko OV, Taveras M, Yao YL, Brenner DJ. An automated imaging system for radiation biodosimetry. Microsc Res Tech 2015; 78:587-98. [PMID: 25939519 PMCID: PMC4479970 DOI: 10.1002/jemt.22512] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 03/26/2015] [Accepted: 04/11/2015] [Indexed: 11/07/2022]
Abstract
We describe here an automated imaging system developed at the Center for High Throughput Minimally Invasive Radiation Biodosimetry. The imaging system is built around a fast, sensitive sCMOS camera and rapid switchable LED light source. It features complete automation of all the steps of the imaging process and contains built-in feedback loops to ensure proper operation. The imaging system is intended as a back end to the RABiT-a robotic platform for radiation biodosimetry. It is intended to automate image acquisition and analysis for four biodosimetry assays for which we have developed automated protocols: The Cytokinesis Blocked Micronucleus assay, the γ-H2AX assay, the Dicentric assay (using PNA or FISH probes) and the RABiT-BAND assay.
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Affiliation(s)
- Guy Garty
- Radiological Research Accelerator Facility, Columbia University, 136 S. Broadway, P.O. Box 21, Irvington, NY 10533,USA
| | - Alan W. Bigelow
- Radiological Research Accelerator Facility, Columbia University, 136 S. Broadway, P.O. Box 21, Irvington, NY 10533,USA
| | - Mikhail Repin
- Center for Radiological Research, Columbia University, 630 W 168 St. New York, NY 10032, USA
| | - Helen C. Turner
- Center for Radiological Research, Columbia University, 630 W 168 St. New York, NY 10032, USA
| | - Dakai Bian
- Department of Mechanical Engineering, Columbia University, 500 West 120th St. New York, NY 10027, USA
| | - Adayabalam S. Balajee
- Center for Radiological Research, Columbia University, 630 W 168 St. New York, NY 10032, USA
| | - Oleksandra V. Lyulko
- Radiological Research Accelerator Facility, Columbia University, 136 S. Broadway, P.O. Box 21, Irvington, NY 10533,USA
| | - Maria Taveras
- Center for Radiological Research, Columbia University, 630 W 168 St. New York, NY 10032, USA
| | - Y. Lawrence Yao
- Department of Mechanical Engineering, Columbia University, 500 West 120th St. New York, NY 10027, USA
| | - David J. Brenner
- Center for Radiological Research, Columbia University, 630 W 168 St. New York, NY 10032, USA
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Sharma PM, Ponnaiya B, Taveras M, Shuryak I, Turner H, Brenner DJ. Correction: High Throughput Measurement of γH2AX DSB Repair Kinetics in a Healthy Human Population. PLoS One 2015; 10:e0131620. [PMID: 26098318 PMCID: PMC4476830 DOI: 10.1371/journal.pone.0131620] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Sharma PM, Ponnaiya B, Taveras M, Shuryak I, Turner H, Brenner DJ. High throughput measurement of γH2AX DSB repair kinetics in a healthy human population. PLoS One 2015; 10:e0121083. [PMID: 25794041 PMCID: PMC4368624 DOI: 10.1371/journal.pone.0121083] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [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: 09/03/2014] [Accepted: 01/30/2015] [Indexed: 11/19/2022] Open
Abstract
The Columbia University RABiT (Rapid Automated Biodosimetry Tool) quantifies DNA damage using fingerstick volumes of blood. One RABiT protocol quantifies the total γ-H2AX fluorescence per nucleus, a measure of DNA double strand breaks (DSB) by an immunofluorescent assay at a single time point. Using the recently extended RABiT system, that assays the γ-H2AX repair kinetics at multiple time points, the present small scale study followed its kinetics post irradiation at 0.5 h, 2 h, 4 h, 7 h and 24 h in lymphocytes from 94 healthy adults. The lymphocytes were irradiated ex vivo with 4 Gy γ rays using an external Cs-137 source. The effect of age, gender, race, ethnicity, alcohol use on the endogenous and post irradiation total γ-H2AX protein yields at various time points were statistically analyzed. The endogenous γ-H2AX levels were influenced by age, race and alcohol use within Hispanics. In response to radiation, induction of γ-H2AX yields at 0.5 h and peak formation at 2 h were independent of age, gender, ethnicity except for race and alcohol use that delayed the peak to 4 h time point. Despite the shift in the peak observed, the γ-H2AX yields reached close to baseline at 24 h for all groups. Age and race affected the rate of progression of the DSB repair soon after the yields reached maximum. Finally we show a positive correlation between endogenous γ-H2AX levels with radiation induced γ-H2AX yields (RIY) (r=0.257, P=0.02) and a negative correlation with residuals (r=-0.521, P=<0.0001). A positive correlation was also observed between RIY and DNA repair rate (r=0.634, P<0.0001). Our findings suggest age, race, ethnicity and alcohol use influence DSB γ-H2AX repair kinetics as measured by RABiT immunofluorescent assay.
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Affiliation(s)
- Preety M. Sharma
- Center for Radiological Research, Columbia University, New York, New York, United States of America
- * E-mail:
| | - Brian Ponnaiya
- Center for Radiological Research, Columbia University, New York, New York, United States of America
| | - Maria Taveras
- Center for Radiological Research, Columbia University, New York, New York, United States of America
| | - Igor Shuryak
- Center for Radiological Research, Columbia University, New York, New York, United States of America
| | - Helen Turner
- Center for Radiological Research, Columbia University, New York, New York, United States of America
| | - David J. Brenner
- Center for Radiological Research, Columbia University, New York, New York, United States of America
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Turner HC, Shuryak I, Taveras M, Bertucci A, Perrier JR, Chen C, Elliston CD, Johnson GW, Smilenov LB, Amundson SA, Brenner DJ. Effect of dose rate on residual γ-H2AX levels and frequency of micronuclei in X-irradiated mouse lymphocytes. Radiat Res 2015; 183:315-24. [PMID: 25738897 DOI: 10.1667/rr13860.1] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The biological risks associated with low-dose-rate (LDR) radiation exposures are not yet well defined. To assess the risk related to DNA damage, we compared the yields of two established biodosimetry end points, γ-H2AX and micronuclei (MNi), in peripheral mouse blood lymphocytes after prolonged in vivo exposure to LDR X rays (0.31 cGy/min) vs. acute high-dose-rate (HDR) exposure (1.03 Gy/min). C57BL/6 mice were total-body irradiated with 320 kVP X rays with doses of 0, 1.1, 2.2 and 4.45 Gy. Residual levels of total γ-H2AX fluorescence in lymphocytes isolated 24 h after the start of irradiation were assessed using indirect immunofluorescence methods. The terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was used to determine apoptotic cell frequency in lymphocytes sampled at 24 h. Curve fitting analysis suggested that the dose response for γ-H2AX yields after acute exposures could be described by a linear dependence. In contrast, a linear-quadratic dose-response shape was more appropriate for LDR exposure (perhaps reflecting differences in repair time after different LDR doses). Dose-rate sparing effects (P < 0.05) were observed at doses ≤2.2 Gy, such that the acute dose γ-H2AX and TUNEL-positive cell yields were significantly larger than the equivalent LDR yields. At the 4.45 Gy dose there was no difference in γ-H2AX expression between the two dose rates, whereas there was a two- to threefold increase in apoptosis in the LDR samples compared to the equivalent 4.45 Gy acute dose. Micronuclei yields were measured at 24 h and 7 days using the in vitro cytokinesis-blocked micronucleus (CBMN) assay. The results showed that MNi yields increased up to 2.2 Gy with no further increase at 4.45 Gy and with no detectable dose-rate effect across the dose range 24 h or 7 days post exposure. In conclusion, the γ-H2AX biomarker showed higher sensitivity to measure dose-rate effects after low-dose LDR X rays compared to MNi formation; however, confounding factors such as variable repair times post exposure, increased cell killing and cell cycle block likely contributed to the yields of MNi with accumulating doses of ionizing radiation.
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Affiliation(s)
- H C Turner
- Center for Radiological Research, Columbia University Medical Center, New York, New York 10032
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Balajee AS, Bertucci A, Taveras M, Brenner DJ. Multicolour FISH analysis of ionising radiation induced micronucleus formation in human lymphocytes. Mutagenesis 2014; 29:447-55. [PMID: 25217771 DOI: 10.1093/mutage/geu041] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Micronucleation of chromosomal DNA is an effective indicator of DNA damage and micronucleus (MN) analysis is a valuable tool for radiation biodosimetry studies. To gain a comprehensive knowledge of micronucleation process after ionising radiation (IR) exposure, whole genome-wide chromosome analysis is desirable. With this objective, multicolour fluorescence in situ hybridization (M-FISH) technique was utilised in the present study to characterise the chromosome content of spontaneous and IR-induced micronuclei in three human donors. M-FISH analysis revealed a radiation dose-dependant increase in the number of micronuclei with multi-chromosome material above 2 Gy and as many as 3-6 multicolour signals were detected in micronuclei after high γ-rays radiation doses (5-10 Gy). Involvement of each human chromosome material was more frequently detected in multicoloured micronuclei than in single-coloured micronuclei at high radiation doses (>2 Gy). Observation of dose-dependant increase in the MN frequency with multi-chromosome material may be due to misrepair of DNA double-strand breaks involving multiple chromosomes leading to asymmetric dicentric or ring chromosomes and acentric fragments. Chromosomes belonging to groups A (1, 2 and 3) and B (4 and 5) were frequently detected in 35-45% of the total micronuclei either as single entities or in combination with other chromosomes. Among the A and B groups, chromosome 1 material was consistently detected at high MN frequencies after radiation exposure in all the donors. Additionally, chromosomes 13 and 19 were more frequently observed in micronuclei than the expected frequency based on DNA content. Our whole genome approach utilising the M-FISH technique revealed that MN formation at high radiation doses might be complex involving multiple chromosome fragments. Understanding the fate and biological consequences of these multi-chromosome-containing micronuclei may provide key molecular insights for some aspects of IR-induced genomic instability and cancer development processes.
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Affiliation(s)
- Adayabalam S Balajee
- Center for Radiological Research, Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University Medical Center, 168th Street, 630 West, New York, NY 10032, USA.
| | - Antonella Bertucci
- Center for Radiological Research, Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University Medical Center, 168th Street, 630 West, New York, NY 10032, USA
| | - Maria Taveras
- Center for Radiological Research, Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University Medical Center, 168th Street, 630 West, New York, NY 10032, USA
| | - David J Brenner
- Center for Radiological Research, Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University Medical Center, 168th Street, 630 West, New York, NY 10032, USA
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Turner HC, Sharma P, Perrier JR, Bertucci A, Smilenov L, Johnson G, Taveras M, Brenner DJ, Garty G. The RABiT: high-throughput technology for assessing global DSB repair. Radiat Environ Biophys 2014; 53:265-72. [PMID: 24477408 PMCID: PMC3999265 DOI: 10.1007/s00411-014-0514-0] [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: 08/02/2013] [Accepted: 01/14/2014] [Indexed: 05/19/2023]
Abstract
At the Center for High-Throughput Minimally Invasive Radiation Biodosimetry, we have developed a rapid automated biodosimetry tool (RABiT); this is a completely automated, ultra-high-throughput robotically based biodosimetry workstation designed for use following a large-scale radiological event, to perform radiation biodosimetry measurements based on a fingerstick blood sample. High throughput is achieved through purpose built robotics, sample handling in filter-bottomed multi-well plates and innovations in high-speed imaging and analysis. Currently, we are adapting the RABiT technologies for use in laboratory settings, for applications in epidemiological and clinical studies. Our overall goal is to extend the RABiT system to directly measure the kinetics of DNA repair proteins. The design of the kinetic/time-dependent studies is based on repeated, automated sampling of lymphocytes from a central reservoir of cells housed in the RABiT incubator as a function of time after the irradiation challenge. In the present study, we have characterized the DNA repair kinetics of the following repair proteins: γ-H2AX, 53-BP1, ATM kinase, MDC1 at multiple times (0.5, 2, 4, 7 and 24 h) after irradiation with 4 Gy γ rays. In order to provide a consistent dose exposure at time zero, we have developed an automated capillary irradiator to introduce DNA DSBs into fingerstick-size blood samples within the RABiT. To demonstrate the scalability of the laboratory-based RABiT system, we have initiated a population study using γ-H2AX as a biomarker.
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Affiliation(s)
- Helen C Turner
- Department of Radiation Oncology, Center for Radiological Research, Columbia University Medical Center, 630 W. 168th St. VC11-240, New York, NY, 10032, USA,
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Akinci MAM, Turner H, Taveras M, Wolosin JM. Differential gene expression in the pig limbal side population: implications for stem cell cycling, replication, and survival. Invest Ophthalmol Vis Sci 2009; 50:5630-8. [PMID: 19608544 DOI: 10.1167/iovs.09-3791] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
PURPOSE To define the molecular signature of limbal SP cells and identify signaling pathways associated with the phenotype of these putative stem cells. METHODS Primary cultures of pig limbal epithelial cells stained with Hoechst 33342 were sorted by flow cytometry into SP and non-SP cells, and purified RNA was processed for microarray analysis with an oligonucleotide spotted array. Expressed transcripts for which SP and non-SP expressions differed by more that 1.5-fold in each paired set and by twofold overall were considered to be differentially expressed. Differential expression was validated by quantitative PCR and immunostaining. Data-mining methods were used to identify cellular processes that are either salient or depressed in the SP cells. RESULTS The microarray identified approximately 9000 distinct, expressed, and identifiable genes. Of those, 382 and 296 were either over- or underexpressed in the SP cells, respectively. Overrepresentation analysis indicated that SP cells are in a low metabolic and biosynthetic state. In addition, a pattern of elevated MXD1, MAXI2, DUSP5, p27/KIP1, and p57/KIP2 and decreased Cyclin D and CDK genes can be expected to slow intrinsic and mitogen-induced G(1)-to-S cell cycle transition. SP cells were also rich in genes associated with stem cell phenotype and genes providing protection against oxidative and/or xenobiotic damage. CONCLUSIONS Microarray analysis of pig limbal SP cells yielded a molecular signature underscoring a phenotype characterized by slow cycling and low metabolic activity. The results provide valuable insights for the preservation and/or replication of epithelial stem cells.
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Affiliation(s)
- M A Murat Akinci
- Department of Ophthalmology, Mount Sinai School of Medicine, New York, New York 10029, USA
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Akinci MAM, Turner H, Taveras M, Barash A, Wang Z, Reinach P, Wolosin JM. Molecular profiling of conjunctival epithelial side-population stem cells: atypical cell surface markers and sources of a slow-cycling phenotype. Invest Ophthalmol Vis Sci 2009; 50:4162-72. [PMID: 19324848 DOI: 10.1167/iovs.08-2861] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Side-population (SP) cells isolated from limbal and conjunctival epithelia derive from cells that are slow cycling in vivo, a known feature of tissue stem cells. The purpose of this study was to define the molecular signature of the conjunctival SP cells and identify markers and signaling pathways associated with the phenotype of these cells. METHODS Overnight cultures of freshly isolated human conjunctival epithelial cells stained with Hoechst 33342 were sorted by flow cytometry into SP and non-SP cohorts. Isolated RNA was processed for microarray analysis using a commercial oligonucleotide spotted array. Results were validated at the gene and protein levels by quantitative PCR and immunologic methods. Data mining methods were used to identify cellular processes relevant for stem cell function. RESULTS Comparative analyses of transcripts expression based on present and absent software calls across four replicate experiments identified 16,993 conjunctival epithelial transcripts including 10,266 unique known genes of approximately 24,000 represented in the array. Of those genes, 1254 and 363 were overexpressed (>2-fold) or underexpressed (<0.5-fold), respectively, in the SP. The overexpressed set included genes coding for proteins that have been associated with (1) embryonic development and/or stem cell self renewal (MSX, MEIS, ID, Hes1, and SIX homeodomain genes); (2) cell survival (e.g., CYP1A1 to degrade aromatic genotoxic compounds); (3) cycling rate (e.g., DUSPs and Pax6 to foster slow cycling); and (4) genes whose expression is not typical in epithelia (e.g., CD62E). CONCLUSIONS The molecular signature of conjunctival SP cells is consistent with a stem cell phenotype. Their gene expression patterns underpin slow cycling and plasticity, features associated with tissue stem cells. The results provide valuable insights for the preservation and/or expansion of epithelial stem cells.
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Affiliation(s)
- M A Murat Akinci
- Department of Ophthalmology, Mount Sinai School of Medicine, New York, New York 10029-6574, USA
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Spitz JC, Ghandi S, Taveras M, Aoys E, Alverdy JC. Characteristics of the intestinal epithelial barrier during dietary manipulation and glucocorticoid stress. Crit Care Med 1996; 24:635-41. [PMID: 8612416 DOI: 10.1097/00003246-199604000-00015] [Citation(s) in RCA: 47] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVES a) To determine the significance of stress-induced alterations in intestinal permeability by measuring the transmucosal flux of formyl-methionyl-leucyl-phenylalanine (f-MLP), a ubiquitous neutrophilic chemoattractant present in the human and rodent colon; and b) to determine whether stress and/or diet influence(s) bacterial adherence-induced changes in epithelial permeability by affecting the production of secretory immunoglobulin A (IgA), the main immune mechanism preventing bacterial adherence. DESIGN Prospective, randomized, controlled study. SETTING University animal research laboratory. SUBJECTS Female Fischer rats. INTERVENTIONS Rats were randomly assigned to four groups of seven animals each. Groups of animals were assigned to receive saline or dexamethasone (0.8 mg/kg ip) and were either starved (5% dextrose in water ad libitum) or fed (water and rat chow) for 48 hrs. MEASUREMENTS AND MAIN RESULTS Mucosal barrier function was evaluated by measuring secretory IgA, bacterial adherence to the intestinal mucosa, and transepithelial electrical resistance, a measure of tight junction permeability. The f-MLP permeation across the mucosa was also determined in segments with significant permeability changes. Results indicate that starvation in dexamethasone-treated rats significantly impairs secretory IgA, promotes bacterial adherence to the mucosa, and results in increased intestinal permeability to f-MLP. These effects are significantly attenuated by the feeding of rat chow. CONCLUSIONS Alterations in intestinal barrier function are characterized by depressed IgA, bacterial adherence to the intestinal mucosa, and permeation of clinically relevant proinflammatory luminal macromolecules (f-MLP). Enteral stimulation with foodstuffs is a necessary protective measure to prevent altered epithelial barrier function during glucocorticoid stress.
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Affiliation(s)
- J C Spitz
- Department of Surgery, University of Illinois, Chicago, USA
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Abstract
BACKGROUND/AIMS Previous studies have shown that dexamethasone administration to rats results in diminution of biliary secretory immunoglobulin A concentration and alters intestinal barrier function to bacteria. The aims of this study were to examine and characterize the effect of dexamethasone on intestinal permeability and to determine the possible influence of bacterial adherence to the mucosa in this process. METHODS Groups of adult Fisher rats were studied, and the effects of dexamethasone administration and bowel decontamination on bacterial adherence and intestinal permeability were determined in various bowel segments. RESULTS Dexamethasone administration was associated with a significant increase in bacterial adherence to the mucosa, which was most pronounced in the cecum (4.33 +/- 0.2 colony forming units (cfu) (log10) per gram of mucosa for control vs. 6.23 +/- 0.2 for dexamethasone). This was accompanied by significant alterations in intestinal permeability as measured by a decrease in transepithelial electrical resistance (49.5 +/- 4.1 omega.cm2 for control vs. 25.4 +/- 2.5 omega.cm2 for dexamethasone). Dual sodium-mannitol flux analysis showed this defect to be predominantly paracellular. Antibiotic decontamination of the intestine completely abrogated the intestinal permeability defect observed in this model. CONCLUSIONS Bacterial-mucosal cell interactions may be responsible for alterations in intestinal permeability after dexamethasone administration.
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Affiliation(s)
- J Spitz
- Department of Surgery, University of Illinois, Chicago
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Malkun C, Alvarado M, Hurtado R, Badui E, Taveras M, Rivera C. [Total situs inversus associated with Lutembacher syndrome]. Arch Inst Cardiol Mex 1986; 56:413-5. [PMID: 2948456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We describe a 19 years old patient with total situs inversus in association with Lutembacher's syndrome, and surgical intervention. Our review of the literature, did not disclosed any similar case.
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