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Roussakis E, Li Z, Nichols AJ, Evans CL. Sauerstoffmessung in der Biomedizin - von der Makro- zur Mikroebene. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201410646] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Roussakis E, Li Z, Nichols AJ, Evans CL. Oxygen-Sensing Methods in Biomedicine from the Macroscale to the Microscale. Angew Chem Int Ed Engl 2015; 54:8340-62. [DOI: 10.1002/anie.201410646] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 01/05/2015] [Indexed: 12/15/2022]
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Swift LM, Asfour H, Posnack NG, Arutunyan A, Kay MW, Sarvazyan N. Properties of blebbistatin for cardiac optical mapping and other imaging applications. Pflugers Arch 2012; 464:503-12. [PMID: 22990759 DOI: 10.1007/s00424-012-1147-2] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 08/20/2012] [Indexed: 11/27/2022]
Abstract
Blebbistatin is a recently discovered myosin II inhibitor. It is rapidly becoming a compound of choice to reduce motion artifacts during cardiac optical mapping, as well as to study cell motility and cell invasion. Although blebbistatin has a number of advantages over other electromechanical uncouplers, many of its properties have yet to be addressed. Here we describe several methodological issues associated with the use of blebbistatin, including its spectral properties, reversibility, and its effect on tissue metabolic state. We show that if precautions are not taken, perfusion with blebbistatin may result in blebbistatin precipitate that accumulates in the vasculature. Although such precipitate is fluorescent, it is not detectable within wavelength bands that are typically used for transmembrane voltage fluorescence imaging (i.e., emission wavelengths >600 nm). Therefore, blockage of the microcirculation by blebbistatin may cause data misinterpretation in studies that use voltage-sensitive dyes. Blebbistatin may also impact imaging of green fluorophores due to the spectral shift it causes in endogenous tissue fluorescence. 3D excitation-emission matrices of blebbistatin in precipitate form and in various solutions (DMSO, water, and 1 % aqueous albumin) revealed significant changes in the fluorescence of this molecule in different environments. Finally, we examined the reversibility of blebbistatin's uncoupling effect on cardiac contraction. Our findings provide important new information about the properties of this myosin II inhibitor, which will aid in the proper design and interpretation of studies that use this compound.
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Affiliation(s)
- Luther M Swift
- Department of Pharmacology and Physiology, The George Washington University Medical Center, 2300 Eye Street, Washington, DC 20037, USA
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Maleki S, Sepehr R, Staniszewski K, Sheibani N, Sorenson CM, Ranji M. Mitochondrial redox studies of oxidative stress in kidneys from diabetic mice. BIOMEDICAL OPTICS EXPRESS 2012; 3:273-81. [PMID: 22312580 PMCID: PMC3269844 DOI: 10.1364/boe.3.000273] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 12/16/2011] [Accepted: 01/01/2012] [Indexed: 05/10/2023]
Abstract
Chronic hyperglycemia during diabetes leads to increased production of reactive oxygen species (ROS) and increased oxidative stress (OS). Here we investigated whether changes in the metabolic state can be used as a marker of OS progression in kidneys. We examined redox states of kidneys from diabetic mice, Akita(/+) and Akita(/+);TSP1(-/-) mice (Akita mice lacking thrombospondin-1, TSP1) with increasing duration of diabetes. OS as measured by mitochondrial redox ratio (NADH/FAD) was detectable shortly after the onset of diabetes and further increased with the duration of diabetes. Thus, cryo fluorescence redox imaging was used as a quantitative marker of OS progression in kidneys from diabetic mice and demonstrated that alterations in the oxidative state of kidneys occur during the early stages of diabetes.
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Affiliation(s)
- Sepideh Maleki
- Biophotonics Laboratory, University of Wisconsin Milwaukee, Department of Electrical Engineering and Computer Science, 3200 N Cramer St., Milwaukee, WI 53211-3029, USA
| | - Reyhaneh Sepehr
- Biophotonics Laboratory, University of Wisconsin Milwaukee, Department of Electrical Engineering and Computer Science, 3200 N Cramer St., Milwaukee, WI 53211-3029, USA
| | - Kevin Staniszewski
- Biophotonics Laboratory, University of Wisconsin Milwaukee, Department of Electrical Engineering and Computer Science, 3200 N Cramer St., Milwaukee, WI 53211-3029, USA
| | - Nader Sheibani
- Departments of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, 600 Highland Avenue, Madison, WI, 53792-4673, USA
| | - Christine M. Sorenson
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, 600 Highland Avenue, Madison, WI, 53792-4673, USA
| | - Mahsa Ranji
- Biophotonics Laboratory, University of Wisconsin Milwaukee, Department of Electrical Engineering and Computer Science, 3200 N Cramer St., Milwaukee, WI 53211-3029, USA
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Kay M, Swift L, Sangave A, Zderic V. High resolution contrast ultrasound and NADH fluorescence imaging of myocardial perfusion in excised rat hearts. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2009; 2008:969-72. [PMID: 19162819 DOI: 10.1109/iembs.2008.4649316] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Simultaneous imaging of myocardial flow and hypoxia could be vital for identifying acute ischemic mechanisms that may trigger an arrhythmia. We have studied the distribution of flow and hypoxia in excised locally ischemic rat hearts using simultaneous contrast ultrasound imaging and beta-nicotinamide adenine dinucleotide (NADH) fluorescence imaging. Local ischemia was induced by controlling flow within a major coronary artery. Intra-myocardial flow was imaged using contrast high-resolution ultrasound (linear probe; 13-6 MHz). An ultrasound contrast agent (UCA) was used to highlight the ischemic border. We observed distinct borders between two perfusion beds. UCA images showed high contrast borders of flow. The progression of UCA through the tissue was clearly visible. Intramyocardial regions of flow overlap could be identified by superimposing images of UCA from two perfusion zones. Borders between hypoxic and normoxic tissue were clearly revealed by increased NADH fluorescence. Hypoxic borders were oriented along borders of flow. In summary, simultaneous ultrasound and NADH imaging of excised hearts from small animals provide high fidelity images for characterizing the distribution of flow and hypoxic tissue during acute localized ischemia.
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Affiliation(s)
- Matthew Kay
- Department of Electrical and Computer Engineering, The George Washington University, Washington, DC 20052, USA.
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Nighswander-Rempel SP, Kupriyanov VV, Shaw RA. Regional cardiac tissue oxygenation as a function of blood flow and pO2: A near-infrared spectroscopic imaging study. JOURNAL OF BIOMEDICAL OPTICS 2006; 11:054004. [PMID: 17092153 DOI: 10.1117/1.2357601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Near-infrared spectroscopic imaging (NIRSI) is useful to assess cardiac tissue oxygenation in arrested and beating hearts, and it shows potential as an intraoperative gauge of the effectiveness of bypass grafting. The purpose of this study was to determine whether NIRSI can reliably differentiate among a range of cardiac oxygenation states, using ischemia and hypoxia models independently. An ischemia-reperfusion model was applied to isolated, beating, blood-perfused porcine hearts, in which the left anterior descending (LAD) artery was cannulated. LAD flow was decreased stepwise to approximately 50, 20, and 0% of normal flow and was completely restored between ischemic episodes. Upon completion of the ischemia-reperfusion protocol, the hearts were further subjected to periods of increasingly severe global hypoxia. Regional oxy- and deoxy-hemoglobin (myoglobin) levels were derived from spectroscopic images (650 to 1050 nm) acquired at each step. Oxygenation maps vividly highlighted the area at risk for all degrees of ischemia. Oxygenation values differed significantly for different LAD flow rates, regardless of whether intermediate reperfusion was applied, and oxygenation values during progressive hypoxia correlated well with blood oxygen saturation. These results suggest that NIRSI is well suited, not only to identify ischemic or hypoxic regions of cardiac tissue, but also to assess the severity of deoxygenation.
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Affiliation(s)
- Stephen P Nighswander-Rempel
- National Research Council of Canada, Institute for Biodiagnostics, 435 Ellice Avenue, Winnipeg, Manitoba R3B 1Y6, Canada
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Fitzgerald JT, Demos S, Michalopoulou A, Pierce JL, Troppmann C. Assessment of renal ischemia by optical spectroscopy1,2. J Surg Res 2004; 122:21-8. [PMID: 15522310 DOI: 10.1016/j.jss.2004.05.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2003] [Indexed: 11/23/2022]
Abstract
INTRODUCTION No reliable method currently exists for quantifying the degree of warm ischemia in kidney grafts before transplantation. We describe a method for evaluating pretransplant warm ischemia time using optical spectroscopic methods. METHODS Lewis rat kidney vascular pedicles were clamped unilaterally in vivo for 0, 5, 10, 20, 30, 60, 90, or 120 min; eight animals were studied at each time point. Injured and contralateral control kidneys were then flushed with Euro-Collins solution, resected, and placed on ice. 335 nm excitation autofluorescence as well as cross-polarized light scattering images were then taken of each injured and control kidney using filters of various wavelengths. The intensity ratio of the injured to normal kidneys was compared to ischemia time. RESULTS Autofluorescence intensity ratios through a 450-nm filter and light scattering intensity ratios through an 800-nm filter both decreased significantly with increasing ischemia time (P < 0.0001 for each method, one-way analysis of variance). All adjacent and nonadjacent time points between 0 and 90 min were distinguishable using one of these two modalities by Fisher's protected least significant difference. CONCLUSIONS Optical spectroscopic methods correlate with warm ischemia time in kidneys that have been subsequently hypothermically preserved. Further studies are needed to correlate results with physiological damage and posttransplant performance.
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Affiliation(s)
- Jason T Fitzgerald
- Department of Surgery, University of California, Davis Medical Center, Sacramento, California, USA.
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Wilson DF, Vinogradov SA, Rozhkov V, Creed J, Rietveld I, Pastuszko A. Monitoring the Dynamics of Tissue Oxygenation in Vivo by Phosphorescence Quenching. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 540:1-5. [PMID: 15174594 DOI: 10.1007/978-1-4757-6125-2_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Affiliation(s)
- David F Wilson
- Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Dunphy I, Vinogradov SA, Wilson DF. Oxyphor R2 and G2: phosphors for measuring oxygen by oxygen-dependent quenching of phosphorescence. Anal Biochem 2002; 310:191-8. [PMID: 12423638 DOI: 10.1016/s0003-2697(02)00384-6] [Citation(s) in RCA: 237] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Oxygen-dependent quenching of phosphorescence is a useful and essentially noninvasive optical method for measuring oxygen in vivo and in vitro. Calibration of the phosphors is absolute, and once phosphors have been calibrated in one laboratory the same constants can be used by anyone else as long as the measurement is done under the same conditions. Two new phosphors, one based on Pd-meso-tetra-(4-carboxyphenyl)porphyrin and the other on Pd-meso-tetra-(4-carboxyphenyl)tetrabenzoporphyrin, are very well suited to in vivo oxygen measurements. Both phosphors are Generation 2 polyglutamic Pd-porphyrin-dendrimers, bearing 16 carboxylate groups on the outer layer. These phosphors are designated Oxyphor R2 and Oxyphor G2, respectively. Both are highly soluble in biological fluids such as blood plasma and their ability to penetrate biological membranes is very low. The maxima in the absorption spectra are at 415 and 524 nm for Oxyphor R2 and 440 and 632 nm for Oxyphor G2, while emissions are near 700 and 800 nm, respectively. The calibration constants of the phosphors are essentially independent of pH in the physiological range (6.4 to 7.8). In vivo application is demonstrated by using Oxyphor G2 to noninvasively determine the oxygen distribution in a subcutaneous tumor growing in rats.
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Affiliation(s)
- Isolde Dunphy
- Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6059, USA
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Nighswander-Rempel SP, Anthony Shaw R, Mansfield JR, Hewko M, Kupriyanov VV, Mantsch HH. Regional variations in myocardial tissue oxygenation mapped by near-infrared spectroscopic imaging. J Mol Cell Cardiol 2002; 34:1195-203. [PMID: 12392893 DOI: 10.1006/jmcc.2002.2058] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Near-infrared fibre-optic single point spectroscopy has been widely exploited to provide information regarding blood volume and oxygenation in vivo, but it does not provide any information on regional differences in perfusion. We have combined the chemical sensitivity of spectroscopy with the spatial sensitivity of imaging to generate maps of regional cardiac oxygenation. Spectroscopic images were acquired for isolated, arrested, blood-perfused porcine hearts (n=4) over the wavelength range 650 and 1050 nm. Spectroscopic images were acquired during normal perfusion, regional ischemia (occlusion of left anterior descending artery) global ischemia, and reperfusion. Hemoglobin (Hb) and myoglobin (Mb) content and oxygenation were determined by reconstructing the tissue spectra measured at each pixel as weighted sums of water, oxy- and deoxy-Hb (and -Mb) absorptivity spectra. The spectroscopic images acquired during regional ischemia clearly revealed increased deoxy-(Hb+Mb) levels and decreased oxy-(Hb+Mb) levels in the ischaemic regions relative to the normally-perfused regions. Global ischemia produced a dramatic decrease in oxy-(Hb+Mb) levels and a moderate increase in deoxy-(Hb+Mb). These images confirm that blood oxygenation can be mapped in cardiac tissue by near-infrared spectroscopic imaging.
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