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Swartz HM, Flood AB. Re-examining What the Results of "a Measurement of Oxygen Level in Tissues" Really Mean. Mol Imaging Biol 2024; 26:391-402. [PMID: 38177616 DOI: 10.1007/s11307-023-01887-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 12/04/2023] [Accepted: 12/05/2023] [Indexed: 01/06/2024]
Abstract
Within this special issue, many eminent investigators report on measurements of oxygen (O2) levels in tissues. Given the complexities of spatial and temporal heterogeneities of O2 in tissues and its many sources, this commentary draws attention to what such measurements do and do not actually assess regarding O2 levels in tissues. Given this limitation, it also discusses how these results can be used most effectively. To provide a convenient mechanism to discuss these issues more fully, this analysis focuses on measurements using EPR oximetry, but these considerations apply to all other techniques. The nature of the delivery of O2 to tissues and the mechanisms by which O2 is consumed necessarily result in very different levels of O2 within the volume of each voxel of a measurement. Better spatial resolution cannot fully resolve the problem because the variations include O2 gradients within each cell. Improved resolution of the time-dependent variation in O2 is also very challenging because O2 levels within tissues can have fluctuations of O2 levels in the range of milliseconds, while most methods require longer times to acquire the data from each voxel. Based on these issues, we argue that the values obtained inevitably are complex aggregates of averages of O2 levels across space and time in the tissue. These complexities arise from the complex physiology of tissues and are compounded by the limitations of the technique and its ability to acquire data. However, one often can obtain very meaningful and useful results if these complexities and limitations are taken into account. We illustrate this, using results obtained with in vivo EPR oximetry, especially utilizing its capacity to make repeated measurements to follow changes in O2 levels that occur with interventions and/or over time.
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Affiliation(s)
- Harold M Swartz
- Dept. of Radiology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA
- Clin-EPR, LLC, Lyme, NH, USA
| | - Ann Barry Flood
- Dept. of Radiology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA.
- Clin-EPR, LLC, Lyme, NH, USA.
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Chen EY, Tse D, Hou H, Schreiber WA, Schaner PE, Kmiec MM, Hebert KA, Kuppusamy P, Swartz HM, Williams BB. Evaluation of a Refined Implantable Resonator for Deep-Tissue EPR Oximetry in the Clinic. APPLIED MAGNETIC RESONANCE 2021; 52:1321-1342. [PMID: 34744319 PMCID: PMC8570533 DOI: 10.1007/s00723-021-01376-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 06/11/2021] [Accepted: 06/17/2021] [Indexed: 05/04/2023]
Abstract
OBJECTIVES (1) Summarize revisions made to the implantable resonator (IR) design and results of testing to characterize biocompatibility;(2) Demonstrate safety of implantation and feasibility of deep tissue oxygenation measurement using electron paramagnetic resonance (EPR) oximetry. STUDY DESIGN In vitro testing of the revised IR and in vivo implantation in rabbit brain and leg tissues. METHODS Revised IRs were fabricated with 1-4 OxyChips with a thin wire encapsulated with two biocompatible coatings. Biocompatibility and chemical characterization tests were performed. Rabbits were implanted with either an IR with 2 oxygen sensors or a biocompatible-control sample in both the brain and hind leg. The rabbits were implanted with IRs using a catheter-based, minimally invasive surgical procedure. EPR oximetry was performed for rabbits with IRs. Cohorts of rabbits were euthanized and tissues were obtained at 1 week, 3 months, and 9 months after implantation and examined for tissue reaction. RESULTS Biocompatibility and toxicity testing of the revised IRs demonstrated no abnormal reactions. EPR oximetry from brain and leg tissues were successfully executed. Blood work and histopathological evaluations showed no significant difference between the IR and control groups. CONCLUSIONS IRs were functional for up to 9 months after implantation and provided deep tissue oxygen measurements using EPR oximetry. Tissues surrounding the IRs showed no more tissue reaction than tissues surrounding the control samples. This pre-clinical study demonstrates that the IRs can be safely implanted in brain and leg tissues and that repeated, non-invasive, deep-tissue oxygen measurements can be obtained using in vivo EPR oximetry.
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Affiliation(s)
- Eunice Y. Chen
- Section of Otolaryngology, Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States and Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Dan Tse
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Huagang Hou
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Wilson A. Schreiber
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Philip E. Schaner
- Section of Radiation Oncology, Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States and Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Maciej M. Kmiec
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Kendra A. Hebert
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Periannan Kuppusamy
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Harold M. Swartz
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
- Section of Radiation Oncology, Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States and Geisel School of Medicine at Dartmouth, Hanover, NH
| | - Benjamin B. Williams
- Department of Radiology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
- Section of Radiation Oncology, Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States and Geisel School of Medicine at Dartmouth, Hanover, NH
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Schaner PE, Tran LBA, Zaki BI, Swartz HM, Demidenko E, Williams BB, Siegel A, Kuppusamy P, Flood AB, Gallez B. The impact of particulate electron paramagnetic resonance oxygen sensors on fluorodeoxyglucose imaging characteristics detected via positron emission tomography. Sci Rep 2021; 11:4422. [PMID: 33627688 PMCID: PMC7904945 DOI: 10.1038/s41598-021-82754-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 01/25/2021] [Indexed: 11/08/2022] Open
Abstract
During a first-in-humans clinical trial investigating electron paramagnetic resonance tumor oximetry, a patient injected with the particulate oxygen sensor Printex ink was found to have unexpected fluorodeoxyglucose (FDG) uptake in a dermal nodule via positron emission tomography (PET). This nodule co-localized with the Printex ink injection; biopsy of the area, due to concern for malignancy, revealed findings consistent with ink and an associated inflammatory reaction. Investigations were subsequently performed to assess the impact of oxygen sensors on FDG-PET/CT imaging. A retrospective analysis of three clinical tumor oximetry trials involving two oxygen sensors (charcoal particulates and LiNc-BuO microcrystals) in 22 patients was performed to evaluate FDG imaging characteristics. The impact of clinically used oxygen sensors (carbon black, charcoal particulates, LiNc-BuO microcrystals) on FDG-PET/CT imaging after implantation in rat muscle (n = 12) was investigated. The retrospective review revealed no other patients with FDG avidity associated with particulate sensors. The preclinical investigation found no injected oxygen sensor whose mean standard uptake values differed significantly from sham injections. The risk of a false-positive FDG-PET/CT scan due to oxygen sensors appears low. However, in the right clinical context the potential exists that an associated inflammatory reaction may confound interpretation.
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Affiliation(s)
- Philip E Schaner
- Department of Medicine Section of Radiation Oncology, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH, 03756, USA.
| | - Ly-Binh-An Tran
- Biomedical Magnetic Resonance, Louvain Drug Research Institute, Universite Catholique du Louvain, Brussels, Belgium
| | - Bassem I Zaki
- Department of Medicine Section of Radiation Oncology, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH, 03756, USA
| | - Harold M Swartz
- Department of Medicine Section of Radiation Oncology, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH, 03756, USA
- Department of Radiology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Eugene Demidenko
- Department of Biomedical Data Science, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Benjamin B Williams
- Department of Medicine Section of Radiation Oncology, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH, 03756, USA
- Department of Radiology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Alan Siegel
- Department of Radiology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
| | - Periannan Kuppusamy
- Department of Medicine Section of Radiation Oncology, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH, 03756, USA
- Department of Radiology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Ann Barry Flood
- Department of Radiology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Bernard Gallez
- Biomedical Magnetic Resonance, Louvain Drug Research Institute, Universite Catholique du Louvain, Brussels, Belgium
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Abou Khouzam R, Brodaczewska K, Filipiak A, Zeinelabdin NA, Buart S, Szczylik C, Kieda C, Chouaib S. Tumor Hypoxia Regulates Immune Escape/Invasion: Influence on Angiogenesis and Potential Impact of Hypoxic Biomarkers on Cancer Therapies. Front Immunol 2021; 11:613114. [PMID: 33552076 PMCID: PMC7854546 DOI: 10.3389/fimmu.2020.613114] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 11/30/2020] [Indexed: 01/19/2023] Open
Abstract
The environmental and metabolic pressures in the tumor microenvironment (TME) play a key role in molding tumor development by impacting the stromal and immune cell fractions, TME composition and activation. Hypoxia triggers a cascade of events that promote tumor growth, enhance resistance to the anti-tumor immune response and instigate tumor angiogenesis. During growth, the developing angiogenesis is pathological and gives rise to a haphazardly shaped and leaky tumor vasculature with abnormal properties. Accordingly, aberrantly vascularized TME induces immunosuppression and maintains a continuous hypoxic state. Normalizing the tumor vasculature to restore its vascular integrity, should hence enhance tumor perfusion, relieving hypoxia, and reshaping anti-tumor immunity. Emerging vascular normalization strategies have a great potential in achieving a stable normalization, resulting in mature and functional blood vessels that alleviate tumor hypoxia. Biomarkers enabling the detection and monitoring of tumor hypoxia could be highly advantageous in aiding the translation of novel normalization strategies to clinical application, alone, or in combination with other treatment modalities, such as immunotherapy.
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Affiliation(s)
- Raefa Abou Khouzam
- Thumbay Research Institute for Precision Medicine, Gulf Medical University, Ajman, United Arab Emirates
| | - Klaudia Brodaczewska
- Laboratory of Molecular Oncology and Innovative Therapies, Military Institute of Medicine, Warsaw, Poland
| | - Aleksandra Filipiak
- Laboratory of Molecular Oncology and Innovative Therapies, Military Institute of Medicine, Warsaw, Poland.,Postgraduate School of Molecular Medicine, Medical University of Warsaw, Warsaw, Poland
| | - Nagwa Ahmed Zeinelabdin
- Thumbay Research Institute for Precision Medicine, Gulf Medical University, Ajman, United Arab Emirates
| | - Stephanie Buart
- INSERM UMR 1186, Integrative Tumor Immunology and Genetic Oncology, Gustave Roussy, EPHE, Faulty. De médecine Univ. Paris-Sud, University Paris-Saclay, Villejuif, France
| | - Cezary Szczylik
- Centre of Postgraduate Medical Education, Department of Oncology, European Health Centre, Otwock, Warsaw, Poland
| | - Claudine Kieda
- Laboratory of Molecular Oncology and Innovative Therapies, Military Institute of Medicine, Warsaw, Poland.,Centre for Molecular Biophysics, UPR CNRS 4301, Orléans, France
| | - Salem Chouaib
- Thumbay Research Institute for Precision Medicine, Gulf Medical University, Ajman, United Arab Emirates.,INSERM UMR 1186, Integrative Tumor Immunology and Genetic Oncology, Gustave Roussy, EPHE, Faulty. De médecine Univ. Paris-Sud, University Paris-Saclay, Villejuif, France
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Buehler PW, Flood AB, Swartz HM. Measurement of Tissue Oxygen as a Novel Approach to Optimizing Red Blood Cell Quality Assessment. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1269:379-386. [PMID: 33966246 DOI: 10.1007/978-3-030-48238-1_60] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The effectiveness of blood transfusions can be impacted by storage and extensive processing techniques that involve treatment of red blood cells (RBCs) with pathogen reduction technologies (e.g., UV-light and chemical treatment), ex vivo stem cell derivation/maturation methods, and bioengineering of RBCs using nanotechnology. Therefore, there is a need to have methods that assess the evaluation of the effectiveness of transfusions to achieve their intended purpose: to increase oxygenation of critical tissues. Consequently, there has been intense interest in the development of techniques targeted at optimizing the assessment of RBC quality in preclinical and clinical settings. We provide a critical assessment of the ability of currently used methods to provide unambiguous information on oxygen levels in tissues and conclude that they cannot do this. This is because they are based on surrogates for the true goal of transfusion, which is to increase oxygenation of critical organs. This does not mean that they are valueless, but it does indicate that other methods are needed to provide direct measurements of oxygen in tissues. We report here on the initial results of a method that can provide direct assessment of the impact of the transfusion on tissue oxygen: EPR oximetry. It has the potential to provide such information in both preclinical and clinical settings for the assessment of blood quality posttransfusion.
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Affiliation(s)
- Paul W Buehler
- Department of Pathology, Department of Pediatrics, Center for Blood Oxygen Transport and Hemostasis, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Ann Barry Flood
- Radiology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Harold M Swartz
- Radiology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA.,Radiation Oncology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
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Schaner PE, Pettus JR, Flood AB, Williams BB, Jarvis LA, Chen EY, Pastel DA, Zuurbier RA, diFlorio-Alexander RM, Swartz HM, Kuppusamy P. OxyChip Implantation and Subsequent Electron Paramagnetic Resonance Oximetry in Human Tumors Is Safe and Feasible: First Experience in 24 Patients. Front Oncol 2020; 10:572060. [PMID: 33194670 PMCID: PMC7653093 DOI: 10.3389/fonc.2020.572060] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 09/21/2020] [Indexed: 12/18/2022] Open
Abstract
Introduction: Tumor hypoxia confers both a poor prognosis and increased resistance to oncologic therapies, and therefore, hypoxia modification with reliable oxygen profiling during anticancer treatment is desirable. The OxyChip is an implantable oxygen sensor that can detect tumor oxygen levels using electron paramagnetic resonance (EPR) oximetry. We report initial safety and feasibility outcomes after OxyChip implantation in a first-in-humans clinical trial (NCT02706197, www.clinicaltrials.gov). Materials and Methods: Twenty-four patients were enrolled. Eligible patients had a tumor ≤ 3 cm from the skin surface with planned surgical resection as part of standard-of-care therapy. Most patients had a squamous cell carcinoma of the skin (33%) or a breast malignancy (33%). After an initial cohort of six patients who received surgery alone, eligibility was expanded to patients receiving either chemotherapy or radiotherapy prior to surgical resection. The OxyChip was implanted into the tumor using an 18-G needle; a subset of patients had ultrasound-guided implantation. Electron paramagnetic resonance oximetry was carried out using a custom-built clinical EPR scanner. Patients were evaluated for associated toxicity using the Common Terminology Criteria for Adverse Events (CTCAE); evaluations started immediately after OxyChip placement, occurred during every EPR oximetry measurement, and continued periodically after removal. The OxyChip was removed during standard-of-care surgery, and pathologic analysis of the tissue surrounding the OxyChip was performed. Results: Eighteen patients received surgery alone, while five underwent chemotherapy and one underwent radiotherapy prior to surgery. No unanticipated serious adverse device events occurred. The maximum severity of any adverse event as graded by the CTCAE was 1 (least severe), and all were related to events typically associated with implantation. After surgical resection, 45% of the patients had no histopathologic findings specifically associated with the OxyChip. All tissue pathology was "anticipated" excepting a patient with greater than expected inflammatory findings, which was assessed to be related to the tumor as opposed to the OxyChip. Conclusion: This report of the first-in-humans trial of OxyChip implantation and EPR oximetry demonstrated no significant clinical pathology or unanticipated serious adverse device events. Use of the OxyChip in the clinic was thus safe and feasible.
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Affiliation(s)
- Philip E Schaner
- Department of Medicine, Dartmouth Hitchcock Medical Center, Lebanon, NH, United States.,Geisel School of Medicine, Dartmouth College, Hanover, NH, United States.,Norris Cotton Cancer Center, Lebanon, NH, United States
| | - Jason R Pettus
- Department of Medicine, Dartmouth Hitchcock Medical Center, Lebanon, NH, United States.,Geisel School of Medicine, Dartmouth College, Hanover, NH, United States.,Norris Cotton Cancer Center, Lebanon, NH, United States.,Department of Pathology, Dartmouth Hitchcock Medical Center, Lebanon, NH, United States
| | - Ann Barry Flood
- Geisel School of Medicine, Dartmouth College, Hanover, NH, United States.,Norris Cotton Cancer Center, Lebanon, NH, United States.,Department of Radiology, Dartmouth Hitchcock Medical Center, Lebanon, NH, United States
| | - Benjamin B Williams
- Department of Medicine, Dartmouth Hitchcock Medical Center, Lebanon, NH, United States.,Geisel School of Medicine, Dartmouth College, Hanover, NH, United States.,Norris Cotton Cancer Center, Lebanon, NH, United States.,Department of Radiology, Dartmouth Hitchcock Medical Center, Lebanon, NH, United States
| | - Lesley A Jarvis
- Department of Medicine, Dartmouth Hitchcock Medical Center, Lebanon, NH, United States.,Geisel School of Medicine, Dartmouth College, Hanover, NH, United States.,Norris Cotton Cancer Center, Lebanon, NH, United States
| | - Eunice Y Chen
- Geisel School of Medicine, Dartmouth College, Hanover, NH, United States.,Norris Cotton Cancer Center, Lebanon, NH, United States.,Department of Surgery, Dartmouth Hitchcock Medical Center, Lebanon, NH, United States
| | - David A Pastel
- Geisel School of Medicine, Dartmouth College, Hanover, NH, United States.,Norris Cotton Cancer Center, Lebanon, NH, United States.,Department of Radiology, Dartmouth Hitchcock Medical Center, Lebanon, NH, United States
| | - Rebecca A Zuurbier
- Geisel School of Medicine, Dartmouth College, Hanover, NH, United States.,Norris Cotton Cancer Center, Lebanon, NH, United States.,Department of Radiology, Dartmouth Hitchcock Medical Center, Lebanon, NH, United States
| | - Roberta M diFlorio-Alexander
- Geisel School of Medicine, Dartmouth College, Hanover, NH, United States.,Norris Cotton Cancer Center, Lebanon, NH, United States.,Department of Radiology, Dartmouth Hitchcock Medical Center, Lebanon, NH, United States
| | - Harold M Swartz
- Department of Medicine, Dartmouth Hitchcock Medical Center, Lebanon, NH, United States.,Geisel School of Medicine, Dartmouth College, Hanover, NH, United States.,Norris Cotton Cancer Center, Lebanon, NH, United States.,Department of Radiology, Dartmouth Hitchcock Medical Center, Lebanon, NH, United States
| | - Periannan Kuppusamy
- Department of Medicine, Dartmouth Hitchcock Medical Center, Lebanon, NH, United States.,Geisel School of Medicine, Dartmouth College, Hanover, NH, United States.,Norris Cotton Cancer Center, Lebanon, NH, United States.,Department of Radiology, Dartmouth Hitchcock Medical Center, Lebanon, NH, United States
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Circulating levels of hydroxylated bradykinin function as an indicator of tissue HIF-1α expression. Sci Bull (Beijing) 2020; 65:1570-1579. [PMID: 36738075 DOI: 10.1016/j.scib.2020.04.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 03/27/2020] [Accepted: 04/14/2020] [Indexed: 02/07/2023]
Abstract
The critical roles of oxygen homeostasis in metabolism are indisputable and hypoxic responses are correlated with the pathogenesis of gastrointestinal, pulmonary, renal diseases and cancers. Evaluating tissue hypoxia to predict treatment outcome is challenging, however, due to the lack of rapid, accurate and non-invasive methods. Hypoxia enhances prolyl-4-hydroxylase α1 (P4HA1) expression, which can convert bradykinin (BK) to hydroxyprolyl-BK (Hyp-BK), leading us to hypothesize that circulating Hyp-BK/BK ratios may reflect tissue hypoxia and predict treatment outcomes. Direct quantification of Hyp-BK peptides in serum or plasma by conventional MALDI-TOF MS analysis is technically challenging. In our study, a nanopore-based fractionation and enrichment protocol was utilized to allow the simple workflow for circulating Hyp-BK/BK analysis. Hypoxia is linked to poor prognosis due to its role in promoting pancreatic cancer progression and metastasis. Here we show that P4HA1 expression was increased in pancreatic tumors versus adjacent tissue, associated with poor survival, and corresponded with tumor expression of the hypoxia inducible factor 1α (HIF-1α) and carbonic anhydrase 9 (CA9). Hypoxia-induced P4HA1 expression and BK conversion to Hyp-BK were found to be HIF-1α dependent, pre-treatment serum Hyp-BK/BK ratios corresponded with tissue HIF-1α and P4HA1 expression, and high Hyp-BK/BK levels corresponded with poor response to therapy. These results suggest that pre-treatment circulating Hyp-BK/BK ratios may have value as a non-invasive, surrogate indicator of tissue hypoxia and tumor responses to therapy.
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Clinical and Statistical Considerations when Assessing Oxygen Levels in Tumors: Illustrative Results from Clinical EPR Oximetry Studies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1232:155-168. [PMID: 31893406 DOI: 10.1007/978-3-030-34461-0_20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
The success of treatment for malignancies, especially those undergoing radiation therapy or chemotherapy, has long been recognized to depend on the degree of hypoxia in the tumor. In addition to the prognostic value of knowing the tumor's initial level of hypoxia, assessing the tumor oxygenation during standard therapy or oxygen-related treatments (such as breathing oxygen-enriched gas mixtures or taking drugs that can increase oxygen supply to tissues) can provide valuable data to improve the efficacy of treatments. A series of early clinical studies of tumors in humans are ongoing at Dartmouth and Emory using electron paramagnetic resonance (EPR) oximetry to assess tumor oxygenation, initially and over time during either natural disease progression or treatment. This approach has the potential for reaching the long-sought goal of enhancing the effectiveness of cancer therapy. In order to effectively reach this goal, we consider the validity of the practical and statistical assumptions when interpreting the measurements made in vivo for patients undergoing treatment for cancer.
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Baek JH, Buehler PW. Can molecular markers of oxygen homeostasis and the measurement of tissue oxygen be leveraged to optimize red blood cell transfusions? Curr Opin Hematol 2019; 26:453-460. [PMID: 31483333 DOI: 10.1097/moh.0000000000000533] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW The clinical indication for transfusing red blood cells (RBCs) is to restore or maintain adequate oxygenation of respiring tissue. Oxygen (O2) transport, delivery, and utilization following transfusion are impacted by perfusion, hemoglobin (Hb) allosteric saturation/desaturation, and the concentration of tissue O2. Bioavailable O2 maintains tissue utilization and homeostasis; therefore, measuring imbalances in supply and demand could be valuable to assessing blood quality and transfusion effectiveness. O2 homeostasis is critically intertwined with erythropoietic response in blood loss and anemia and the hormones that modulate iron mobilization and RBC production (e.g., erythropoietin, erythroferrone, and hepcidin) are intriguing markers for the monitoring of transfusion effectiveness in acute and chronic settings. The evaluation of RBC donor unit quality and the determination of RBC transfusion needs are emerging areas for biomarker development and minimally invasive O2 measurements. RECENT FINDINGS Novel methods for assessing circulatory and tissue compartment biomarkers of transfusion effectiveness are suggested. In addition, monitoring of tissue oxygenation by indirect and direct measurements of O2 is available and applied in experimental settings. SUMMARY Herein, we discuss tissue O2 homeostasis, related aspects of erythropoiesis, molecular markers and measurements of tissue oxygenation, all aimed at optimizing transfusion and assessing blood quality.
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Affiliation(s)
- Jin Hyen Baek
- Laboratory of Biochemistry and Vascular Biology, Division of Blood Components and Devices, Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
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Electron paramagnetic resonance oximetry as a novel approach to monitor the effectiveness and quality of red blood cell transfusions. BLOOD TRANSFUSION = TRASFUSIONE DEL SANGUE 2019; 17:296-306. [PMID: 31184583 DOI: 10.2450/2019.0037-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 04/17/2019] [Indexed: 12/18/2022]
Abstract
BACKGROUND The goal of red blood cell transfusion is to improve tissue oxygenation. Assessment of red blood cell quality and individualised therapeutic needs can be optimised using direct oxygen (O2) measurements to guide treatment. Electron paramagnetic resonance oximetry is capable of accurate, repeatable and minimally invasive measurements of tissue pO2. Here we present preclinical proof-of-concept of the utility of electron paramagnetic resonance oximetry in an experimental setting of acute blood loss, transfusion, and post-transfusion monitoring. MATERIALS AND METHODS Donor rat blood was collected, leucocyte-reduced, and stored at 4 °C in AS-3 for 1, 7 and 14 days. Red blood cell morphology, O2 equilibrium, p50 and Hill numbers from O2 binding and dissociation curves were evaluated in vitro. Recipient rats were bled and maintained at a mean arterial pressure of 30-40 mmHg and hind limb muscle (biceps femoris) pO2 at 25-50% of baseline. Muscle pO2 was monitored continuously over the course of experiments to assess the effectiveness of red blood cell preparations at different stages of blood loss and restoration. RESULTS Red blood cell morphology, O2 equilibrium and p50 values of intra-erythrocyte haemoglobin were significantly altered by refrigerated storage for both 7 and 14 days. Transfusion of red blood cells stored for 7 or 14 days demonstrated an equivalently impaired ability to restore hind limb muscle pO2, consistent with in vitro observations and transfusion with albumin. Red blood cells refrigerated for 1 day demonstrated normal morphology, in vitro oxygenation and in vivo restoration of tissue pO2. DISCUSSION Electron paramagnetic resonance oximetry represents a useful approach to assessing the quality of red blood cells and subsequent transfusion effectiveness.
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Desmet CM, Tran LBA, Danhier P, Gallez B. Characterization of a clinically used charcoal suspension for in vivo EPR oximetry. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2018; 32:205-212. [DOI: 10.1007/s10334-018-0704-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/21/2018] [Accepted: 08/31/2018] [Indexed: 12/18/2022]
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