1
|
Arosio P, Orsini F, Brero F, Mariani M, Innocenti C, Sangregorio C, Lascialfari A. The effect of size, shape, coating and functionalization on nuclear relaxation properties in iron oxide core-shell nanoparticles: a brief review of the situation. Dalton Trans 2023; 52:3551-3562. [PMID: 36880505 DOI: 10.1039/d2dt03387a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
In this perspective article, we present a short selection of some of the most significant case studies on magnetic nanoparticles for potential applications in nanomedicine, mainly magnetic resonance. For almost 10 years, our research activity focused on the comprehension of the physical mechanisms on the basis of the nuclear relaxation of magnetic nanoparticles in the presence of magnetic fields; taking advantage of the insights gathered over this time span, we report on the dependence of the relaxation behaviour on the chemico-physical properties of magnetic nanoparticles and discuss them in full detail. In particular, a critical review is carried out on the correlations between their efficiency as contrast agents in magnetic resonance imaging and the magnetic core of magnetic nanoparticles (mainly iron oxides), their size and shape, and the coating and solvent used for making them biocompatible and well dispersible in physiological media. Finally, the heuristic model proposed by Roch and coworkers is presented, as it was extensively adopted to describe most of the experimental data sets. The large amount of data analyzed allowed us to highlight both the advantages and limitations of the model.
Collapse
Affiliation(s)
- Paolo Arosio
- Dipartimento di Fisica, INFN and INSTM RU, Università degli Studi di Milano, 20133 Milano, Italy.
| | - Francesco Orsini
- Dipartimento di Fisica, INFN and INSTM RU, Università degli Studi di Milano, 20133 Milano, Italy.
| | - Francesca Brero
- Dipartimento di Fisica, INFN and INSTM RU, Università degli Studi di Pavia, 27100 Pavia, Italy
| | - Manuel Mariani
- Dipartimento di Fisica, INFN and INSTM RU, Università degli Studi di Pavia, 27100 Pavia, Italy
| | - Claudia Innocenti
- Dipartimento di Chimica, Università di Firenze and INSTM, 50019 Sesto Fiorentino (FI), Italy
- ICCOM-CNR, 50019 Sesto Fiorentino (FI), Italy
| | - Claudio Sangregorio
- Dipartimento di Chimica, Università di Firenze and INSTM, 50019 Sesto Fiorentino (FI), Italy
- ICCOM-CNR, 50019 Sesto Fiorentino (FI), Italy
| | - Alessandro Lascialfari
- Dipartimento di Fisica, INFN and INSTM RU, Università degli Studi di Pavia, 27100 Pavia, Italy
| |
Collapse
|
2
|
Abstract
The heart has the highest energy demands per gram of any organ in the body and energy metabolism fuels normal contractile function. Metabolic inflexibility and impairment of myocardial energetics occur with several common cardiac diseases, including ischemia and heart failure. This review explores several decades of innovation in cardiac magnetic resonance spectroscopy modalities and their use to noninvasively identify and quantify metabolic derangements in the normal, failing, and diseased heart. The implications of this noninvasive modality for predicting significant clinical outcomes and guiding future investigation and therapies to improve patient care are discussed.
Collapse
|
3
|
Albumin nanocomposites with MnO 2/Gd 2O 3 motifs for precise MR imaging of acute myocardial infarction in rabbit models. Biomaterials 2019; 230:119614. [PMID: 31753475 DOI: 10.1016/j.biomaterials.2019.119614] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 10/23/2019] [Accepted: 11/07/2019] [Indexed: 02/05/2023]
Abstract
The severe mortality and morbidity of myocardial infarction requests appropriate and accurate detection. Considering pathological profile of the acidic myocardial infarction microenvironments, herein, the low pH-sensitive albumin nanocomposites with MnO2 motifs (MnO2@BSA) have been engineered for T1-weighted MR imaging of myocardial infarction, while using non-pH-responsive Gd2O3@BSA nanocomposites as control. The nanocomposites were 20-30 nm in diameter with spheroid morphology. Besides, the MnO2@BSA have exhibited pH-triggered releasing of Mn2+, demonstrating approximately 38-fold and 55-fold increased molecular relaxivity at acute myocardial infarction-mimicking pH 6.5 (13.08 mM-1s-1) and macrophage intracellular pH 5.0 (18.76 mM-1s-1) compared to the extremely low relaxivity (0.34 mM-1s-1) at normal physiological conditions (pH 7.4). However, the Gd2O3@BSA with molecular relaxivity approximately 10 mM-1s-1 were without pH-sensitive properties. Furthermore, the MnO2@BSA have demonstrated high accumulation in the acute myocardial infarction regions and fast metabolism from the body after systemic injection, accounting high contrast enhancement for accurate MR imaging of acute myocardial infarction in rabbit models, demonstrating better diagnostic performance over the controls.
Collapse
|
4
|
Nilsson S, Wikström M, Martinussen HJ, Ericsson A, Wikström G, Waldenström A, Øksendal AN, Hemmingsson A. Dy-DTPA-BMA as an Indicator of Tissue Viability in MR Imaging. Acta Radiol 2016. [DOI: 10.1177/028418519503600403] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The aim of this study was to investigate whether dysprosium (Dy) induced signal intensity (SI) loss in infarcted tissue in MR imaging. Myocardial infarction was induced in 12 pigs and Dy-DTPA-BMA (1.0 mmol/kg b.w.) was administered i.v. to 6 pigs 4 hours after occlusion and allowed to accumulate in the infarctions for 2 hours. Dy was analysed by inductively coupled plasma atomic emission spectrometry in infarcted and non-ischaemic tissue samples. The remaining 6 pigs, not administered contrast medium, served as controls. The infarctions demonstrated a high SI in the proton density- and T2-weighted sequences in both groups ( ex vivo), although the Dy-DTPA-BMA group demonstrated a 3-fold greater concentration of Dy in infarcted compared with non-ischaemic myocardium. The lack of SI loss after Dy accumulation indicates that susceptibility effects are minor or absent in infarcted myocardium.
Collapse
Affiliation(s)
- Stefan Nilsson
- Department of Diagnostic Radiology, University Hospital, Uppsala, Sweden
| | - Mats Wikström
- Department of Diagnostic Radiology, University Hospital, Uppsala, Sweden
| | | | - Anders Ericsson
- Department of Diagnostic Radiology, University Hospital, Uppsala, Sweden
| | - Gerhard Wikström
- Department of Internal Medicine, University Hospital, Uppsala, Sweden
| | | | | | - Anders Hemmingsson
- Department of Diagnostic Radiology, University Hospital, Uppsala, Sweden
| |
Collapse
|
5
|
Wikström M, Martinussen HJ, Wikström G, Ericsson A, Nyman R, Waldenström A, Hemmingsson A. Magnetic Resonance Imaging of Acute Myocardial Infarction in Pigs Using Gd-Dtpa. Acta Radiol 2016. [DOI: 10.1177/028418519003100617] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Six pigs with coronary artery occlusion were investigated with MR imaging before and subsequently for about 2.5 hours at repeated intervals after the intravenous administration of Gd-DTPA (0.4 mmol/kg). The animals were sacrificed after a total occlusion time of 6 hours and the hearts were excised. The excised hearts were then reexamined in the MR equipment and stained with TTC (triphenyl tetrazolium) in order to define areas of infarction. Four control hearts with 6-hour-old infarctions were only imaged ex vivo without any previous administration of contrast media. In vivo, there was no clear demarcation of infarction with or without Gd-DTPA. Ex vivo, without any contrast media, the infarctions were poorly discriminated with a discretely increased signal intensity relative to normal myocardium in the T2 weighted images. Gd-DTPA was found to accumulate in the infarctions, which caused an elevated signal intensity most pronounced in the T1 weighted images. This considerably improved the delineation of the infarcted area.
Collapse
|
6
|
Wikström M, Martinussen HJ, Ericsson A, Wikström G, Waldenström A, Hemmingsson A. Double-Contrast Enhanced Mr Imaging of Myocardial Infarction in the Pig. Acta Radiol 2016. [DOI: 10.1177/028418519303400114] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Myocardial infarction was induced by ligating a diagonal branch of the left anterior descending artery in 18 pigs. All pigs were sacrificed 6 h after the occlusion. Dysprosium diethylenetriaminepentaacetic acid bismethylamide (Dy-DTPA-BMA, 1.0 mmol/kg) was administered i.v. to 6 pigs, starting 3 min before sacrifice (injection time approximately 1 min). In a second group of 6 pigs, a double-contrast technique was used, consisting of an i.v. injection of gadolinium-DTPA-BMA (0.4 mmol/kg) 2 h before sacrifice, followed by an i.v. injection of Dy-DTPA-BMA (1.0 mmol/kg) 3 min before sacrifice. Six additional pigs, subjected to 6 h of coronary artery occlusion without administration of contrast medium, served as controls. The hearts were excised and imaged with MR. In the control animals, the infarctions demonstrated an increased signal intensity in the proton density- and T2-weighted images. Administration of Dy-DTPA-BMA primarily improved infarct visualization in the proton density- and T2-weighted images, due to reduction of signal intensity in nonischemic myocardium. The double-contrast technique further improved infarct visualization in all sequences.
Collapse
|
7
|
Wikström M, Martinussen HJ, Wikström G, Ericsson A, Nyman R, Waldenström A, Hemmingsson A. Mr Imaging of Acute Myocardial Infarction in Pigs Using GD-Dtpa-Labeled Dextran. Acta Radiol 2016. [DOI: 10.1177/028418519203300404] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Myocardial infarctions were induced in 12 pigs. In 6 pigs, dextran-(Gd-DTPA)15 (≈0.1 mmol Gd/kg b.w.) was injected i.v. 4 to 4.5 hours after coronary artery occlusion. ECG gated MR images were obtained repeatedly before (n = 4) and after (n = 6) contrast medium injection. Relaxation times in blood samples were measured repeatedly. The animals were sacrificed 2 hours after contrast medium administration. The hearts were excised, reexamined in the MR equipment and stained with triphenyltetrazolium chloride (TTC) in order to define areas of infarction. The remaining 6 pigs were sacrificed 6 hours after occlusion without administration of contrast medium. These hearts were only imaged ex vivo. In vivo, the infarctions could not be identified with or without dextran-(Gd-DTPA)15. Ex vivo, without contrast medium, the infarctions had an increased signal intensity, most pronounced in the T2-weighted images. Dextran-(Gd-DTPA)15 caused a prolonged, pronounced shortening of T1 and T2 in blood samples. The infarct demarcation improved in the T1-weighted images after injection of dextran-(Gd-DTPA)15, due to a moderate enhancement in normal myocardium and a stronger enhancement at the periphery of the infarctions, while the central parts of the infarctions were only weakly enhanced.
Collapse
|
8
|
|
9
|
Li L, Zhang H, Li T, Zhang B. Involvement of Adenosine Monophosphate-Activated Protein Kinase in Morphine-induced Cardioprotection. J Surg Res 2011; 169:179-87. [DOI: 10.1016/j.jss.2009.11.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2009] [Revised: 10/11/2009] [Accepted: 11/04/2009] [Indexed: 10/20/2022]
|
10
|
Villaraza AJL, Bumb A, Brechbiel MW. Macromolecules, dendrimers, and nanomaterials in magnetic resonance imaging: the interplay between size, function, and pharmacokinetics. Chem Rev 2010; 110:2921-59. [PMID: 20067234 PMCID: PMC2868950 DOI: 10.1021/cr900232t] [Citation(s) in RCA: 470] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Aaron Joseph L. Villaraza
- Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ambika Bumb
- Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Martin W. Brechbiel
- Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| |
Collapse
|
11
|
Mihardja SS, Sievers RE, Lee RJ. The effect of polypyrrole on arteriogenesis in an acute rat infarct model. Biomaterials 2008; 29:4205-10. [PMID: 18678406 DOI: 10.1016/j.biomaterials.2008.07.021] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Accepted: 07/09/2008] [Indexed: 10/21/2022]
Abstract
The conductive polymer polypyrrole was blended with alginate to investigate its potential in tissue engineering applications. This study showed that increasing the polypyrrole content altered the macroscopic structural morphology of the polymer blend scaffold, but did not alter the overall conductivity of the polymer blend, which was 10(-2)S/cm(2). Culturing of human umbilical vein endothelial cells on the polymer blend scaffolds showed that addition of polypyrrole mediated cell attachment to the polymer scaffold. However, cell proliferation was dependent on the polypyrrole content with 0.025% v/v polypyrrole giving the best results. Using an ischemia-reperfusion rat myocardial infarction model, local injection of 0.025% polypyrrole in alginate polymer blend into the infarct zone yielded significantly higher levels of arteriogenesis at 5 weeks post-treatment when compared with the saline control group and the alginate only treatment group. In addition, this alginate-polypyrrole polymer blend significantly enhanced infiltration of myofibroblasts into the infarct area when compared with the control group. The results of this study highlight the potential clinical benefit of using this alginate-polypyrrole polymer blend as an injectable scaffold to repair ischemic myocardium after myocardial infarction.
Collapse
Affiliation(s)
- Shirley S Mihardja
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA 94143, USA
| | | | | |
Collapse
|
12
|
Lee RJ, Fang Q, Davol PA, Gu Y, Sievers RE, Grabert RC, Gall JM, Tsang E, Yee MS, Fok H, Huang NF, Padbury JF, Larrick JW, Lum LG. Antibody targeting of stem cells to infarcted myocardium. Stem Cells 2006; 25:712-7. [PMID: 17138964 DOI: 10.1634/stemcells.2005-0602] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Hematopoietic stem cell (HSC) therapy for myocardial repair is limited by the number of stem cells that migrate to, engraft in, and proliferate at sites of injured myocardium. To alleviate this limitation, we studied whether a strategy using a bispecific antibody (BiAb) could target human stem cells specifically to injured myocardium and preserve myocardial function. Using a xenogeneic rat model whereby ischemic injury was induced by transient ligation of the left anterior descending artery (LAD), we determined the ability of a bispecific antibody to target human CD34+ cells to specific antigens expressed in ischemic injured myocardium. A bispecific antibody comprising an anti-CD45 antibody recognizing the common leukocyte antigen found on HSCs and an antibody recognizing myosin light chain, an organ-specific injury antigen expressed by infarcted myocardium, was prepared by chemical conjugation. CD34+ cells armed and unarmed with this BiAb were injected intravenously in rats 2 days postmyocardial injury. Immunohistochemistry studies showed that the armed CD34+ cells specifically localized to the infarcted region of the heart, colocalized with troponin T-stained cells, and colocalization with vascular structures. Compared to unarmed CD34+ cells, the bispecific antibody improved delivery of the stem cells to injured myocardium, and such targeted delivery was correlated with improved myocardial function 5 weeks after infarction (p < .01). Bispecific antibody targeting offers a unique means to improve the delivery of stem cells to facilitate organ repair and a tool to study stem cell biology.
Collapse
Affiliation(s)
- Randall J Lee
- Department of Medicine and Cardiovascular Research Institute, University of California-San Francisco, 500 Parnassus Avenue, San Francisco, CA 94143-1354, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Saeed M, Weber O, Lee R, Do L, Martin A, Saloner D, Ursell P, Robert P, Corot C, Higgins CB. Discrimination of Myocardial Acute and Chronic (Scar) Infarctions on Delayed Contrast Enhanced Magnetic Resonance Imaging With Intravascular Magnetic Resonance Contrast Media. J Am Coll Cardiol 2006; 48:1961-8. [PMID: 17112985 DOI: 10.1016/j.jacc.2006.03.071] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2005] [Revised: 01/26/2006] [Accepted: 03/01/2006] [Indexed: 11/17/2022]
Abstract
OBJECTIVES The purpose of this study was to examine the potential of intravascular gadolinium (Gd)-chelates in discriminating acute from chronic myocardial infarctions (MIs). BACKGROUND A potential limitation of delayed contrast enhanced magnetic resonance imaging with standard extracellular Gd-chelates is its inability to distinguish acute from chronic MIs. METHODS Eight pigs with MIs were studied at 3 days and 8 weeks. Inversion recovery gradient echo (IR-GRE), T(1)-turbo spin echo (TSE), and T(2)-TSE images were acquired before and after administration of intravascular and extracellular Gd-chelates. Triphenyltetrazolium chloride (TTC) was used to delineate infarctions at postmortem. Masson's trichrome and Biotinylated Bandeiria simplicifolia Isolectin B4 stains were used to characterize scarred myocardium. Analysis of variance was used to compare signal intensity (SI) ratios and determine differences in infarct extent. RESULTS The intravascular agent produced differential enhancement of acute infarctions at 3 days (SI ratio 5.8 +/- 1.3) but not at 8 weeks (1.6 +/- 0.4, p < 0.01). The extracellular agent provided differential enhancement of both acute (SI ratio 7.7 +/- 1.4) and chronic (7.5 +/- 0.9) infarctions. The extents of enhanced regions in acute infarctions were not different after intravascular (16.0 +/- 1.3%) or extracellular (17.1 +/- 1.7%) agents; at 8 weeks the extent of extracellular enhanced and TTC regions were smaller (13.2 +/- 1.4% and 12.0 +/- 1.5%, respectively). Masson's trichrome stain demonstrated dense scar tissue, signaling the complete healing of infarction. The vascular stain showed that scar tissue contained fewer microvessels oriented in a haphazard array. CONCLUSIONS The combination of intravascular and extracellular Gd-chelates discriminates acute from chronic infarctions on delayed images. This double contrast agent approach can be used to determine the age and extent of infarctions.
Collapse
Affiliation(s)
- Maythem Saeed
- Department of Radiology, University of California San Francisco, San Francisco, California 94134-0628, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Barrett T, Kobayashi H, Brechbiel M, Choyke PL. Macromolecular MRI contrast agents for imaging tumor angiogenesis. Eur J Radiol 2006; 60:353-66. [PMID: 16930905 DOI: 10.1016/j.ejrad.2006.06.025] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2006] [Revised: 06/11/2006] [Accepted: 06/14/2006] [Indexed: 11/21/2022]
Abstract
Angiogenesis has long been accepted as a vital process in the growth and metastasis of tumors. As a result it is the target of several novel anti-cancer medications. Consequently, there is an urgent clinical need to develop accurate, non-invasive imaging techniques to improve the characterization of tumor angiogenesis and the monitoring of the response to anti-angiogenic therapy. Macromolecular MR contrast media (MMCM) offer this diagnostic potential by preferentially exploiting the inherent hyperpermeable nature of new tumor vessels compared with normal vessels. Over the last 10-15 years many classes of MMCM have been developed. When evaluated with dynamic contrast enhanced (DCE) MRI, a number of MMCM have demonstrated in vivo imaging properties that correlate with ex vivo histological features of angiogenesis. The enhancement patterns with some MMCM have been reported to correlate with tumor grade, as well as show response to anti-angiogenic and anti-vascular drugs. Future applications of MMCM include targeted angiogenesis imaging and drug delivery of anti-cancer 'payloads'. Herein we discuss the best known MMCMs along with their advantages and disadvantages.
Collapse
Affiliation(s)
- Tristan Barrett
- Molecular Imaging Program and Radioimmune and Inorganic Chemistry Section, Radiation Oncology Branch, National Cancer Institute, Building 10, Room 1B40, Bethesda, MD 20892-1088, USA
| | | | | | | |
Collapse
|
15
|
Crozier SJ, Zhang X, Wang J, Cheung J, Kimball SR, Jefferson LS. Activation of signaling pathways and regulatory mechanisms of mRNA translation following myocardial ischemia-reperfusion. J Appl Physiol (1985) 2006; 101:576-82. [PMID: 16690784 PMCID: PMC2631174 DOI: 10.1152/japplphysiol.01122.2005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Protein expression in the heart is altered following periods of myocardial ischemia. The changes in protein expression are associated with increased cell size that can be maladaptive. There is little information regarding the regulation of protein expression through the process of mRNA translation during ischemia and reperfusion in the heart. Therefore, the purpose of this study was to identify changes in signaling pathways and downstream regulatory mechanisms of mRNA translation in an in vivo model of myocardial ischemia and reperfusion. Hearts were collected from rats whose left main coronary arteries had either been occluded for 25 min or reversibly occluded for 25 min and subsequently reperfused for 15 min. Following reperfusion, both the phosphoinositide 3-kinase and mitogen-activated protein kinase pathways were activated, as evidenced by increased phosphorylation of Akt (PKB), extracellular signal-regulated kinase 1/2, and p38 mitogen-activated protein kinase. Activation of Akt stimulated signaling through the protein kinase mammalian target of rapamycin, as evidenced by increased phosphorylation of two of its effectors, the ribosomal protein S6 kinase and the eukaryotic initiation factor eIF4E binding protein 1. Ischemia and reperfusion also resulted in increased phosphorylation of eIF2 and eIF2B. These changes in protein phosphorylation suggest that control of mRNA translation following ischemia and reperfusion is modulated through a number of signaling pathways and regulatory mechanisms.
Collapse
Affiliation(s)
- Stephen J Crozier
- Dept. of Cellular and Molecular Physiology, The Pennsylvania State Univ. College of Medicine, PO Box 850, Hershey, PA 17033, USA
| | | | | | | | | | | |
Collapse
|
16
|
Zacharowski K, Zacharowski P, Reingruber S, Petzelbauer P. Fibrin(ogen) and its fragments in the pathophysiology and treatment of myocardial infarction. J Mol Med (Berl) 2006; 84:469-77. [PMID: 16733765 DOI: 10.1007/s00109-006-0051-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Accepted: 01/31/2006] [Indexed: 10/24/2022]
Abstract
The occlusion of a coronary artery leads to ischemia of the myocardium, while permanent occlusion results in cell death and myocardial dysfunction. Early restoration of blood flow is the only means to reduce or prevent myocardial necrosis, but-paradoxically-reperfusion itself contributes to injury of the heart. In animal models, this phenomenon is well described, and there are many different unrelated approaches to reduce reperfusion injury. In humans, however, pharmacological interventions have so far failed to reduce myocardial reperfusion injury. We summarize the pathogenesis of reperfusion injury, detailing the role of fibrin(ogen) and its derivatives. Moreover, we introduce a new concept for fibrin derivatives as potential targets for reperfusion therapy.
Collapse
Affiliation(s)
- Kai Zacharowski
- Molecular Cardioprotection and Inflammation Group, Department of Anesthesia, University Hospital of Düsseldorf, Moorenstrasse 5, 40225, Düsseldorf, Germany.
| | | | | | | |
Collapse
|
17
|
Huang NF, Yu J, Sievers R, Li S, Lee RJ. Injectable biopolymers enhance angiogenesis after myocardial infarction. ACTA ACUST UNITED AC 2006; 11:1860-6. [PMID: 16411832 DOI: 10.1089/ten.2005.11.1860] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Novel strategies by which to repair ischemic myocardium after myocardial infarction include the use of three-dimensional polymer scaffolds. A comparative study was carried out to assess the therapeutic potential of fibrin, collagen I, and Matrigel as injectable biopolymers for repair after myocardial infarction. Using a rat model of left coronary artery occlusion followed by reperfusion, local injection of the biopolymers into the infarct zone yielded significantly higher levels of capillary formation, when compared with the saline control group, at 5 weeks posttreatment. However, the degree of angiogenesis was not significantly different among the biopolymers. In addition, the collagen biopolymer significantly enhanced infiltration of myofibroblasts into the infarct area when compared with the control group. The results of this study highlight the potential clinical benefit of these biopolymers as injectable scaffolds or cell delivery vehicles to the infarct zone after infarction.
Collapse
Affiliation(s)
- Ngan F Huang
- UCSF/UCB Joint Bioengineering Graduate Group, University of California Berkeley, Berkeley, California, USA
| | | | | | | | | |
Collapse
|
18
|
D'Arceuil HE, de Crespigny AJ, Pelc L, Howard D, Seri S, Hashiguchi Y, Nakatani A, Moseley ME. A comparison of CH3-DTPA-GD (NMS60) and GD-DTPA for evaluation of acute myocardial ischemia. Int J Cardiovasc Imaging 2005; 21:539-47. [PMID: 16175444 DOI: 10.1007/s10554-005-2103-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2004] [Accepted: 02/01/2005] [Indexed: 11/29/2022]
Abstract
PURPOSE Our objective was to evaluate the use of a new medium weight MRI contrast agent, NMS60 (a synthetic oligomeric Gd-complex containing three Gd(3+) atoms, molecular weight 2158 Da) compared to gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) in a pig myocardial ischemia model. MATERIALS We used 13 male white hybrid pigs. Animals were scanned in the acute phase 2-3 h after the onset of myocardial ischemia. Scans were acquired on a 1.5T GE Signa with dynamic T1-weighted imaging during a bolus injection of 0.1 mmol(gd)/kg of either NMS60 or Gd-DTPA, 2D CINE at 5 min after injection, and T1-weighted spin-echo imaging up to 60 min. RESULTS The postcontrast CINE scans showed improved contrast-to-noise ratio after NMS60 injection, compared to Gd-DTPA. There was significantly greater enhancement with NMS60 in both normal myocardium and in the ischemic lesion on T1-weighted spin-echo scans up to 60 min after injection. The dose ranging study shows a 24% greater enhancement with NMS60 compared to Gd-DTPA. DISCUSSION This new medium weighted contrast agent offers improved enhancement for cardiac MRI, compared to Gd-DTPA, with similar washout kinetics and lower toxicity, and may prove useful for better detection of myocardial ischemia as well as delayed or hyperenhancement after reperfusion.
Collapse
Affiliation(s)
- H E D'Arceuil
- Lucas MRS/I Center, Department of Radiology, Stanford University, CA, USA.
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Christman KL, Fang Q, Kim AJ, Sievers RE, Fok HH, Candia AF, Colley KJ, Herradon G, Ezquerra L, Deuel TF, Lee RJ. Pleiotrophin induces formation of functional neovasculature in vivo. Biochem Biophys Res Commun 2005; 332:1146-52. [PMID: 15949466 DOI: 10.1016/j.bbrc.2005.04.174] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2005] [Accepted: 04/26/2005] [Indexed: 02/04/2023]
Abstract
Pleiotrophin (PTN) is a heparin-binding growth/differentiation inducing cytokine that shares 50% amino acid sequence identity and striking domain homology with Midkine (MK), the only other member of the Ptn/Mk developmental gene family. The Ptn gene is expressed in sites of early vascular development in embryos and in healing wounds and its constitutive expression in many human tumors is associated with an angiogenic phenotype, suggesting that PTN has an important role in angiogenesis during development and in wound repair and advanced malignancies. To directly test whether PTN is angiogenic in vivo, we injected a plasmid to express PTN into ischemic myocardium in rats. Pleiotrophin stimulated statistically significant increases in both normal appearing new capillaries and arterioles each of which had readily detectable levels of the arteriole marker, smooth muscle cell alpha-actin. Furthermore, the newly formed blood vessels were shown to interconnect with the existent coronary vascular system. The results of these studies demonstrate directly that PTN is an effective angiogenic agent in vivo able to initiate new vessel formation that is both normal in appearance and function. The data suggest that PTN signals the more "complete" new blood vessel formation through its ability to stimulate different functions in different cell types not limited to the endothelial cell.
Collapse
Affiliation(s)
- Karen L Christman
- University of California Berkeley and San Francisco Joint Bioengineering Graduate Group, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Christman KL, Fang Q, Yee MS, Johnson KR, Sievers RE, Lee RJ. Enhanced neovasculature formation in ischemic myocardium following delivery of pleiotrophin plasmid in a biopolymer. Biomaterials 2005; 26:1139-44. [PMID: 15451633 DOI: 10.1016/j.biomaterials.2004.04.025] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2004] [Accepted: 04/08/2004] [Indexed: 11/18/2022]
Abstract
Coronary heart disease is currently the leading killer in the western world. Therapeutic angiogenic agents are currently being examined for treatment of this disease. We have recently demonstrated the effective use of Pleiotrophin (PTN) as a therapeutic agent for treatment of ischemic myocardium. We have also shown that injection of the biopolymer fibrin glue preserves left ventricular geometry and prevents a deterioration of cardiac function following myocardial infarction. Due to the low transfection efficiency of naked plasmid injections, we examined the use of PTN plasmid and the biopolymer as a gene-activated matrix in the myocardium. In this study, we demonstrate that delivery of PTN plasmid in fibrin glue increases neovasculature formation compared to injection of the naked plasmid in saline.
Collapse
Affiliation(s)
- Karen L Christman
- University of California Berkeley and San Francisco Joint Bioengineering Graduate Group, San Francisco, CA 94143, USA.
| | | | | | | | | | | |
Collapse
|
21
|
Christman KL, Vardanian AJ, Fang Q, Sievers RE, Fok HH, Lee RJ. Injectable fibrin scaffold improves cell transplant survival, reduces infarct expansion, and induces neovasculature formation in ischemic myocardium. J Am Coll Cardiol 2004; 44:654-60. [PMID: 15358036 DOI: 10.1016/j.jacc.2004.04.040] [Citation(s) in RCA: 365] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2003] [Revised: 03/22/2004] [Accepted: 04/13/2004] [Indexed: 11/28/2022]
Abstract
OBJECTIVES In this study, we determined whether fibrin glue improves cell transplant retention and survival, reduces infarct expansion, and induces neovasculature formation. BACKGROUND Current efforts in restoring the myocardium after myocardial infarction (MI) include the delivery of viable cells to replace necrotic cardiomyocytes. Cellular transplantation techniques are, however, limited by transplanted cell retention and survival within the ischemic tissue. METHODS The left coronary artery of rats was occluded for 17 min followed by reperfusion. One week later, bovine serum albumin (BSA), fibrin glue, skeletal myoblasts in BSA, or skeletal myoblasts in fibrin glue were injected into the infarcted area of the left ventricle. The animals were euthanized five weeks after injection, and their hearts were excised, fresh frozen, and sectioned for histology and immunohistochemistry. RESULTS After five weeks, the mean area covered by skeletal myoblasts in fibrin glue was significantly greater than the area covered by myoblasts injected in BSA. Myoblasts within the infarct were often concentrated around arterioles. The infarct scar size and myoblasts in the fibrin group were significantly smaller than those in the control and BSA groups. Fibrin glue also significantly increased the arteriole density in the infarct scar as compared with the control group. CONCLUSIONS This study indicates that fibrin glue increases cell transplant survival, decreases infarct size, and increases blood flow to ischemic myocardium. Therefore, fibrin glue may have potential as a biomaterial scaffold to improve cellular cardiomyoplasty treat and MIs.
Collapse
Affiliation(s)
- Karen L Christman
- University of California Berkeley and San Francisco Joint Bioengineering Graduate Group, San Francisco, California, USA
| | | | | | | | | | | |
Collapse
|
22
|
Srichai MB, Schvartzman PR, Sturm B, Kasper JM, Lieber ML, White RD. Extent of myocardial scarring on nonstress delayed-contrast-enhancement cardiac magnetic resonance imaging correlates directly with degrees of resting regional dysfunction in chronic ischemic heart disease. Am Heart J 2004; 148:342-8. [PMID: 15309007 DOI: 10.1016/j.ahj.2004.03.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Hyper-enhancement on delayed-enhancement magnetic resonance imaging (DE-MRI) is a marker of irreversible myocardial injury. Both reversible and irreversible ischemically injured regions of myocardium develop reductions in systolic function compared with unaffected regions. This study evaluated whether there is a relationship between myocardial hyper-enhancement from remote scarring on DE-MRI and the degree of myocardial circumferential shortening (%CS) as determined with dynamic MRI tissue tagging (TAG-MRI) in the setting of chronic ischemic heart disease (CIHD). METHODS Thirty-five patients with CIHD and 8 control patients underwent nonstress, resting DE-MRI and TAG-MRI. A total of 168 CIHD and 96 control segments from the basal- and middle-thirds of the left ventricle (LV) were selected to achieve a balanced test set. With a 16-segment model, segmental myocardial scarring was graded on the basis of the amount of hyper-enhancement on DE-MRI. With TAG-MRI images, segmental %CS was calculated. RESULTS Patients with CIHD had lower LV ejection fraction compared with the control patients (28% vs 67%). The %CS of normal segments was notably different from %CS of CIHD segments, regardless of the presence or absence of myocardial hyper-enhancement on DE-MRI. Among the CIHD segments, however, %CS correlated inversely with the amount of myocardial hyper-enhancement from scarring (P <.0001, r = -0.38). CONCLUSIONS On cardiac MRI for CIHD, myocardial hyper-enhancement correlates inversely with %CS, supporting the direct relationship between the amount of remote myocardial scarring determined with nonstress DE-MRI and baseline resting functional impairment.
Collapse
Affiliation(s)
- Monvadi B Srichai
- Department of Radiology, Section of Cardiovascular Imaging, Cleveland Clinic Foundation, Ohio 44195, USA
| | | | | | | | | | | |
Collapse
|
23
|
Wu EX, Tang H, Wong KK, Wang J. Mapping cyclic change of regional myocardial blood volume using steady-state susceptibility effect of iron oxide nanoparticles. J Magn Reson Imaging 2004; 19:50-8. [PMID: 14696220 DOI: 10.1002/jmri.10426] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To demonstrate an in vivo magnetic resonance imaging (MRI) technique that maps the cyclic change of regional myocardial blood volume (MBV) during the cardiac cycle. MATERIALS AND METHODS The method is based on the dominant T(2)* shortening effect of iron oxide nanoparticle-induced magnetic susceptibility perturbation in myocardium in the steady state. The technique was demonstrated in vivo with normal mouse hearts at 9.4 T. The regional MBV maps in left ventricular myocardium were computed from the steady-state pre- and post-monocrystalline iron oxide nanoparticle (MION) gradient echo (GE) cine images. Cyclic changes of MBV in normal mice were analyzed quantitatively in different transmural and angular locations. RESULTS High-resolution MBV maps at various cardiac points were obtained. The study showed a general regional MBV decrease from end-diastole (ED) to end-systole (ES). Percentage reductions were 18.2 +/- 6.6%, P < 0.03 in the lateral wall and 24.7 +/- 3.1%, P < 0.0002 in the interventricular septum. The heterogeneous characteristics of MBV transmural distribution were also reported. CONCLUSION The steady-state susceptibility effect of intravascular superparamagnetic contrast agent (CA) can be used to map the cyclic change of regional MBV. This imaging approach is relatively simple and may provide a new perspective for functional assessment of the microvasculature in myocardium.
Collapse
Affiliation(s)
- Ed X Wu
- Department of Radiology, College of Physicians & Surgeons, Columbia University, New York, New York, USA.
| | | | | | | |
Collapse
|
24
|
Christman KL, Fok HH, Sievers RE, Fang Q, Lee RJ. Fibrin Glue Alone and Skeletal Myoblasts in a Fibrin Scaffold Preserve Cardiac Function after Myocardial Infarction. ACTA ACUST UNITED AC 2004; 10:403-9. [PMID: 15165457 DOI: 10.1089/107632704323061762] [Citation(s) in RCA: 286] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Current efforts in cardiac tissue engineering center around the use of scaffolds that deliver cells to the epicardial surface. In this study, we examined the effects of fibrin glue as an injectable scaffold and wall support in ischemic myocardium. The left coronary artery of rats was occluded for 17 min, followed by reperfusion. Echocardiography was performed 8 days after infarction. One to 2 days later, either 0.5% bovine serum albumin (BSA) in phosphate-buffered saline, fibrin glue alone, skeletal myoblasts alone, or skeletal myoblasts in fibrin glue were injected into the ischemic left ventricle. Echocardiography was again performed 5 weeks after injection. The animals were then sacrificed and the hearts were fresh frozen and sectioned for histology and immunohistochemistry. Both the fractional shortening (FS) and infarct wall thickness of the BSA group decreased significantly after 5 weeks (p = 0.0005 and 0.02, respectively). In contrast, both measurements for the fibrin glue group, cells group, and cells in fibrin glue group did not change significantly (FS: p = 0.18, 0.89, and 0.19, respectively; wall thickness: p = 0.40, 0.44, 0.43, respectively). Fibrin glue is capable of preserving infarct wall thickness and cardiac function after a myocardial infarction in rats and may be useful as a biomaterial scaffold for myocardial cell transplantation.
Collapse
Affiliation(s)
- Karen L Christman
- University of California Berkeley and San Francisco Joint Bioengineering Graduate Group, San Francisco, California, USA
| | | | | | | | | |
Collapse
|
25
|
William Watts Parmley, MD: a conversation with the editor**This series of interviews is underwritten by an unrestricted grant from Bristol-Myers Squibb. Am J Cardiol 2002. [DOI: 10.1016/s0002-9149(02)02318-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
26
|
Magnetic resonance imaging contrast agents: Theory and the role of dendrimers. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s1874-5229(02)80006-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
|
27
|
Hangaishi M, Nakajima H, Taguchi J, Igarashi R, Hoshino J, Kurokawa K, Kimura S, Nagai R, Ohno M. Lecithinized Cu, Zn-superoxide dismutase limits the infarct size following ischemia-reperfusion injury in rat hearts in vivo. Biochem Biophys Res Commun 2001; 285:1220-5. [PMID: 11478786 DOI: 10.1006/bbrc.2001.5319] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Covalent binding of 4 molecules of phosphatidylcholine palmitoyl to human recombinant superoxide dismutase (SOD) results in a compound (lecithinized SOD) that has a longer half-life and greater affinity to the cell membrane than unmodified SOD. We investigated whether lecithinized SOD played a protective role against myocardial ischemia-reperfusion injuries in rats. Rats underwent 45 min of myocardial ischemia by occluding the left coronary artery followed by 120 min of reperfusion. They were randomly assigned to receive either lecithinized SOD, polyethylene glycol conjugated SOD (PEG-SOD), unmodified SOD, free lecithin derivative, or PBS intravenously at 5 min prior to reperfusion. Myocardial infarct area assessed by TTC staining was smaller in lecithinized SOD group than PEG-SOD, unmodified SOD, free lecithin derivative or control group. Blood pressure and heart rate was similar in each group. ELISA demonstrated SOD level in the heart was significantly high in lecithinized SOD group, especially in the heart of ischemia at risk. Although serum SOD level of PEG-SOD was as high as lecithinized SOD, SOD level of the heart was low. These data suggested lecithinized SOD had a protective effect in myocardial ischemia-reperfusion injuries through its increased bioavailability.
Collapse
Affiliation(s)
- M Hangaishi
- Department of Cardiovascular Medicine, University of Tokyo, Tokyo, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Abstract
Currently available magnetic resonance (MR) contrast agents are not confined to the intravascular space because of their small molecular size. These agents produce peak vascular enhancement for only a short period. Conversely, blood pool agents have longer intravascular residence time and higher relaxivity. Therefore these agents provide MR angiography with flexibility, versatility, and accuracy. With blood pool agents, the timing of contrast injection becomes less significant because the optimal imaging window is in tens of minutes rather than seconds. In addition, larger anatomic regions can be imaged optimally. Preliminary evidence appears to support the notion that blood pool agents may play a diagnostic role in coronary, peripheral, and pulmonary angiography. Besides their ability to increase vascular contrast, blood pool agents provide physiologic information, including rate of entry, rate of accumulation, and rate of elimination. MR imaging with blood pool agents also have proven to be of significant value in the assessments of myocardial perfusion and microvascular permeability. In anticipation of broad clinical use, blood pool agents are currently being evaluated in human trails. Examples include gadolinium-chelate that binds in vivo to albumin to form blood pool agents and ultrasmall superparamagnetic iron oxide particles. This review discusses the applications of MR blood pool agents in the cardiovascular system. J. Magn. Reson. Imaging 2000;12:890-898.
Collapse
Affiliation(s)
- M Saeed
- Department of Radiology, University of California, San Francisco, California 94143, USA.
| | | | | |
Collapse
|
29
|
Saeed M, Wendland MF, Watzinger N, Akbari H, Higgins CB. MR contrast media for myocardial viability, microvascular integrity and perfusion. Eur J Radiol 2000; 34:179-95. [PMID: 10927160 DOI: 10.1016/s0720-048x(00)00198-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Cardiovascular imaging requires an appreciation of rapidly evolving MR imaging sequences as well as careful utilization of intravascular, extracellular and intracellular MR contrast media. At the present time, clinical studies are restricted to the use of extracellular MR contrast media. MR imaging has the potential to noninvasively measure multiple parameters of the cardiovascular system in a single imaging session. Recent advances in fast and ultrafast MR imaging have considerably enhanced the capability of this technique, beyond the assessment of left ventricular wall motion and morphology into visualization of the coronary arteries and measurement of blood flow. During the course of the last several years, multiple strategies for imaging viable myocardium have been developed and validated using MR contrast media. Contrast enhanced dynamic MR imaging provides information regarding microvascular integrity and perfusion. Because these information can be provided noninvasively by MR imaging, repeated measurements can be performed in longitudinal studies to monitor the progression or regression of myocardial injury. Similar studies are needed to examine the effects of newly developed cardioprotective therapeutics. Development of suitable intravascular MR contrast medium may be essential for visualization of the coronary arteries and interventional therapies. MR imaging may emerge as one-stop-shop for evaluating the heart and coronary system. This capability will make MR imaging cost-effective in the first decade of this millennium.
Collapse
Affiliation(s)
- M Saeed
- Department of Radiology, University of California, Box 0628, 505 Parnassus Ave, San Francisco, CA 94143, USA.
| | | | | | | | | |
Collapse
|
30
|
Kroft LJ, Doornbos J, van der Geest RJ, de Roos A. Blood pool contrast agent CMD-A2-Gd-DOTA-enhanced MR imaging of infarcted myocardium in pigs. J Magn Reson Imaging 1999; 10:170-7. [PMID: 10441021 DOI: 10.1002/(sici)1522-2586(199908)10:2<170::aid-jmri10>3.0.co;2-m] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The purpose of this study was to assess the ability of the new blood pool contrast agent meglumine-carboxymethyldextran-ethylenediamino-gadoterate (CMD-A2-Gd-DOTA) to depict acute occlusive myocardial infarction (AMI). First-pass gradient-echo and delayed spin-echo magnetic resonance imaging (MRI) was performed 5 days after induction of AMI in a pig model. MRI was correlated with pathology. First-pass imaging with CMD-A2-Gd-DOTA allowed detection of infarcted myocardium in all pigs (n = 7). The infarction was recognized as a black spot on MRI as well as on a parametric image. The signal intensity (SI) amplitudes of normal versus infarcted myocardium were 80.55 +/- 18.61 versus 8.48 +/- 15.50 on MRI and 81.62 +/- 18.50 versus 1.61 +/- 3.73 on the parametric image (both P values < 0.001. The contrast ratio between normal and infarcted myocardium was not significantly improved on spin-echo MRI, suggesting largely intact vascular integrity outside the occluded area. CMD-A2-Gd-DOTA is useful for depicting occlusive myocardial infarction by first-pass MRI. Spin-echo imaging is promising in assessing vascular integrity. J. Magn. Reson. Imaging 1999;10:170-177.
Collapse
Affiliation(s)
- L J Kroft
- Department of Radiology, C2-S, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | | | | | | |
Collapse
|
31
|
Rudin M, Beckmann N, Porszasz R, Reese T, Bochelen D, Sauter A. In vivo magnetic resonance methods in pharmaceutical research: current status and perspectives. NMR IN BIOMEDICINE 1999; 12:69-97. [PMID: 10392805 DOI: 10.1002/(sici)1099-1492(199904)12:2<69::aid-nbm548>3.0.co;2-d] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In the last decade, in vivo MR methods have become established tools in the drug discovery and development process. In this review, several successful and potential applications of MRI and MRS in stroke, rheumatoid and osteo-arthritis, oncology and cardiovascular disorders are dealt with in detail. The versatility of the MR approach, allowing the study of various pathophysiological aspects in these disorders, is emphasized. New indication areas, for the characterization of which MR methods have hardly been used up to now, such as respiratory, gastro-intestinal and skin diseases, are outlined in a subsequent section. A strength of MRI, being a non-invasive imaging modality, is the ability to provide functional, i.e. physiological, readouts. Functional MRI examples discussed are the analysis of heart wall motion, perfusion MRI, tracer uptake and clearance studies, and neuronal activation studies. Functional information may also be derived from experiments using target-specific contrast agents, which will become important tools in future MRI applications. Finally the role of MRI and MRS for characterization of transgenic and knock-out animals, which have become a key technology in modern pharmaceutical research, is discussed. The advantages of MRI and MRS are versatility, allowing a comprehensive characterization of a diseased state and of the drug intervention, and non-invasiveness, which is of relevance from a statistical, economical and animal welfare point of view. Successful applications in drug discovery exploit one or several of these aspects. In addition, the link between preclinical and clinical studies makes in vivo MR methods highly attractive methods for pharmaceutical research.
Collapse
Affiliation(s)
- M Rudin
- Core Technologies Area, Novartis Pharma Research, Basel, Switzerland.
| | | | | | | | | | | |
Collapse
|
32
|
Daldrup H, Shames DM, Wendland M, Okuhata Y, Link TM, Rosenau W, Lu Y, Brasch RC. Correlation of dynamic contrast-enhanced MR imaging with histologic tumor grade: comparison of macromolecular and small-molecular contrast media. AJR Am J Roentgenol 1998; 171:941-9. [PMID: 9762973 DOI: 10.2214/ajr.171.4.9762973] [Citation(s) in RCA: 212] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The endothelial integrity of microvessels is disrupted in malignant tumors. Quantitative assays of tumor microvascular characteristics based on dynamic MR imaging were correlated with histopathologic grade in mammary soft-tissue tumors. MATERIALS AND METHODS A spectrum of tumors, benign through highly malignant, was induced in 33 female rats by administration of N-ethyl-N-nitrosourea, a potent carcinogen. Dynamic contrast-enhanced MR imaging was performed using a small-molecular contrast medium (gadopentetate, molecular weight = 0.5 kDa) and a macromolecular contrast medium (albumin-(Gd-DTPA)30, molecular weight = 92 kDa) at an interval of 1-2 days. Permeability surface area product (PS), as estimated by the corresponding endothelial transfer coefficient (K(PS)), and fractional plasma volume (fPV) were calculated for each tumor and each contrast agent using a two-compartment bidirectional kinetic model. MR imaging microvascular characteristics were correlated with histopathologic tumor grade. RESULTS Tumor permeability to macromolecular contrast medium, characterized by K(PS), showed a highly positive correlation with tumor grade (r2 = .76, p < 10(-10)). K(PS) values were zero for all benign and some low-grade carcinomas, greater than zero in all other carcinomas, and increased in magnitude with higher tumor grade. A considerably smaller but significantly positive correlation was found between fPV and tumor grade using macromolecular contrast medium (r2 = .25, p < .003). No correlation between K(PS) or fPV values and tumor grade was found using gadopentetate (r2 = .01, p > .95 and r2 = .03, p > .15, respectively). CONCLUSION Quantitative tumor microvascular permeability assays generated with macromolecular MR imaging contrast medium correlate closely with histologic tumor grade. No significant correlation is found using small-molecular gadopentetate.
Collapse
Affiliation(s)
- H Daldrup
- Department of Radiology, University of California, San Francisco 94143-0628, USA
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Bremerich J, Wendland MF, Arheden H, Wyttenbach R, Gao DW, Huberty JP, Dae MW, Higgins CB, Saeed M. Microvascular injury in reperfused infarcted myocardium: noninvasive assessment with contrast-enhanced echoplanar magnetic resonance imaging. J Am Coll Cardiol 1998; 32:787-93. [PMID: 9741528 DOI: 10.1016/s0735-1097(98)00315-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVES The purpose of this study was to measure the accumulation of labeled albumin and to visualize its distribution pattern in reperfused infarcted myocardium as a function of time between onset of reperfusion and administration of the tracer. BACKGROUND Myocardial microvascular injury leads to leakage of albumin from the intravascular space. Quantitative measurements of GdDTPA-albumin with inversion recovery echoplanar imaging (IR-EPI) may allow noninvasive monitoring of microvascular injury. METHODS After 1 h of coronary artery occlusion, 56 rats were injected with GdDTPA-albumin or 123I-GdDTPA-albumin either immediately before reperfusion or 1/2, 1 or 24 h after reperfusion. GdDTPA-albumin in blood, normal myocardium and reperfused infarction was dynamically measured with IR-EPI during 1 h postinjection (PI). Autoradiograms were obtained at 15 min PI. Accumulation of labeled albumin in myocardium was expressed as the ratio of myocardial to blood content. RESULTS In normal myocardium, the ratio of changes of relaxation rate-ratio (deltaR1-ratio) was 0.12+/-0.01 and did not change over 1 h. In reperfused infarction, however, the deltaR1-ratio increased after administration. Animals given GdDTPA-albumin before reperfusion exhibited fastest accumulation (deltaR1-ratio 15 min PI: 0.56+/-0.03) and essentially homogeneous distribution. The accumulation was slower when administered at 1/2, 1 and 24 h after reperfusion (deltaR1-ratios 15 min PI: 0.39+/-0.03; 0.31+/-0.04; 0.16+/-0.01; p < 0.001 compared to administration before reperfusion). Moreover, the tracer accumulated predominantly in the periphery of the injury zone. CONCLUSIONS Amount and distribution pattern of labeled albumin in reperfused infarction are modulated by duration of reperfusion. The accumulation of GdDTPA-albumin can be quantified by IR-EPI. Thus, IR-EPI may be useful to noninvasively monitor myocardial microvascular injury in reperfused infarction.
Collapse
Affiliation(s)
- J Bremerich
- Department of Radiology, University of California San Francisco, 94143-0628, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Dendale P, Franken PR, Block P, Pratikakis Y, De Roos A. Contrast enhanced and functional magnetic resonance imaging for the detection of viable myocardium after infarction. Am Heart J 1998; 135:875-80. [PMID: 9588420 DOI: 10.1016/s0002-8703(98)70049-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE Viable myocardium after acute myocardial infarction may be characterized by magnetic resonance imaging (MRI) either by demonstration of recovery of wall motion under dobutamine stress or by perfusion patterns after contrast medium administration. This study examines the relation between the two techniques. MATERIALS AND METHODS Gradient-echo MRI at rest and under low-dose dobutamine stress was performed in 28 patients within the first 2 weeks after acute myocardial infarction. In addition, spin-echo MRI was performed after gadolinium-DOTA administration. Wall motion at rest and under stress was scored to assess the contractile reserve of the infarct regions. Infarct enhancement patterns were classified as subendocardial, transmural, or as a doughnut pattern. RESULT Subendocardial or absent infarct enhancement was related to functional recovery under stress in 31 of 37 infarct segments. Transmural infarct enhancement was correlated with the absence of functional recovery in 10 of 17 infarct segments (p < 0.002), indicating nonviability. The doughnut pattern was exclusively associated with the absence of viability (five of five). CONCLUSION Contrast enhancement patterns are related to residual myocardial viability.
Collapse
Affiliation(s)
- P Dendale
- Department of Cardiology, Free University of Brussels (VUB), Belgium
| | | | | | | | | |
Collapse
|
35
|
Saeed M, van Dijke CF, Mann JS, Wendland MF, Rosenau W, Higgins CB, Brasch RC. Histologic confirmation of microvascular hyperpermeability to macromolecular MR contrast medium in reperfused myocardial infarction. J Magn Reson Imaging 1998; 8:561-7. [PMID: 9626869 DOI: 10.1002/jmri.1880080308] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A macromolecular MR contrast medium (MMCM) designed to permit histochemical staining and specific tissue localization, albumin-(biotin)10-(Gd-DTPA)25 (Bio-Alb-Gd), was used in a rat model of reperfused myocardial infarction to confirm the presence and distribution of microvascular hyperpermeability. T1-weighted spin-echo images were acquired before and after administration of Bio-Alb-Gd. An avidin-biotin-complex (ABC) stain, specific for the biotinylated MR contrast medium, was used to define the MMCM distribution and to detect any regional change in microvascular permeability related to infarction. Immediately after Bio-Alb-Gd administration, the infarcted region was enhanced, with greatest signal intensity noted at the rim and less at the center. There was a gradual increase in signal intensity of the initially hypointense central region. The steady increase in signal intensity of the central region suggested convection transport of MMCM through the interstitial space and its influx into cellular compartment after leakage from the vascular compartment. Histologic findings confirmed regional microvascular hyperpermeability corresponding to the site of infarction and a predominant rim distribution of the MMCM. Bio-Alb-Gd was identified at high microscopic power in the intravascular, interstitial, and intracellular spaces at the periphery of reperfused infarcted myocardium. Bio-Alb-Gd can be used as an MR contrast medium in reperfused infarcted myocardium to confirm the existence and to localize altered microvascular permeability to macromolecules. Bio-Alb-Gd contrast technique removes all the ambiguity between the distribution of the MR or other imaging contrast agent and the distribution of the substrate for histochemical staining.
Collapse
Affiliation(s)
- M Saeed
- Department of Radiology, University of California, San Francisco 94143, USA
| | | | | | | | | | | | | |
Collapse
|
36
|
Brasch RC, Daldrup H, Shames D, Wendland M, Okuhata Y, Rosenau W. Macromolecular contrast media-enhanced MRI estimates of microvascular permeability correlate with histopathologic tumor grade. Acad Radiol 1998; 5 Suppl 1:S2-5. [PMID: 9561030 DOI: 10.1016/s1076-6332(98)80043-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- R C Brasch
- Department of Radiology, University of California San Francisco 94143-0628, USA
| | | | | | | | | | | |
Collapse
|
37
|
Roberts HC, Saeed M, Roberts TP, Brasch RC. Assessment of acute and reperfused myocardial ischemia using GdDTPA, GdDTPA-cascade-24-polymer and albumin-GdDTPA. Acad Radiol 1998; 5 Suppl 1:S31-3; discussion S45-6. [PMID: 9561037 DOI: 10.1016/s1076-6332(98)80051-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- H C Roberts
- Department of Radiology, University of California, San Francisco 94143, USA
| | | | | | | |
Collapse
|
38
|
Schwitter J, Saeed M, Wendland MF, Derugin N, Canet E, Brasch RC, Higgins CB. Influence of severity of myocardial injury on distribution of macromolecules: extravascular versus intravascular gadolinium-based magnetic resonance contrast agents. J Am Coll Cardiol 1997; 30:1086-94. [PMID: 9316544 DOI: 10.1016/s0735-1097(97)00245-3] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVES This study sought to 1) compare the distribution of extravascular (573 Da) and intravascular (92 kDa) magnetic resonance (MR) contrast agents in reperfused infarcted myocardium, and 2) investigate the effect of injury severity on these distribution patterns. BACKGROUND Myocardial distribution of low and high molecular weight contrast agents depends on vascular permeability, diffusive/convective transport within the interstitium and accessibility of the intracellular compartment (cellular integrity). METHODS To vary the severity of myocardial injury, 72 rats were subjected to 20, 30, 45 or 75 min (n = 18, respectively) of coronary artery occlusion. After 2 h of reflow, the animals received either 0.05 mmol/kg of gadolinium-diethylenetriaminepentaacetic acid-bismethylamide (Gd-DTPA-BMA) (n = 24), (Gd-DTPA)30-albumin (n = 24) or saline (control group, n = 24). Three minutes after injection, the hearts were excised and imaged (spin-echo imaging parameters: repetition time 300 ms, echo time 8 ms, 2-tesla system), followed by triphenyltetrazolium chloride staining for infarct detection and sizing. RESULTS Histomorphometric and MR infarct size (expressed as percent of slice surface) correlated well: r = 0.96 for Gd-DTPA-BMA; r = 0.95 for (Gd-DTPA)30-albumin. On Gd-DTPA-BMA-enhanced images, reperfused myocardial infarctions were homogeneously enhanced. The ratio of signal intensity of infarcted/ normal myocardium increased with increasing duration of ischemia (overall p < 0.0001, analysis of variance [ANOVA]), indicating an increase in the distribution volume of Gd-DTPA-BMA in postischemic myocardium. On (Gd-DTPA)30-albumin-enhanced images, reperfused infarctions consisted of a bright border zone and a less enhanced central core. The extent of the core increased with increasing duration of ischemia (overall p value < 0.0001, ANOVA). CONCLUSIONS At 2 h of reperfusion, the distribution of MR contrast agents in postischemic myocardium is 1) specific for extravascular and intravascular agents, and 2) modulated by the duration of ischemia.
Collapse
Affiliation(s)
- J Schwitter
- Department of Radiology, University of California at San Francisco 94143-0628, USA
| | | | | | | | | | | | | |
Collapse
|
39
|
Roberts HC, Saeed M, Roberts TP, Mühler A, Shames DM, Mann JS, Stiskal M, Demsar F, Brasch RC. Comparison of albumin-(Gd-DTPA)30 and Gd-DTPA-24-cascade-polymer for measurements of normal and abnormal microvascular permeability. J Magn Reson Imaging 1997; 7:331-8. [PMID: 9090587 DOI: 10.1002/jmri.1880070213] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The purpose of this study was to compare a new MR macromolecular contrast medium (MMCM), gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA)-24-cascade-polymer, to a well-studied prototype MMCM, for the potential of distinguishing tissues of varying endothelial permeability. Three tissue models of varying capillary permeability were studied in a total of 46 rats: normal myocardium (normal capillaries), subcutaneously implanted adenocarcinoma (mild capillary leak), and reperfused infarcted myocardium (high capillary leak). TI-weighted MRI was performed before and dynamically after injection of either albumin-(Gd-DTPA)30 or the cascade polymer (each .02 mmol gadolinium [Gd] per kg). Data analysis based on a two-compartment kinetic model yielded estimates of fractional blood volume (BV) (percentage) and fractional leak rate (FLR) (1 per hour). Permeability to the cascade polymer as reflected in FLR was considerable in normal myocardium (8.24 per hour), of similar value in tumors (8.55 per hour), but significantly greater in infarcted myocardium (39.17 per hour, P < .01) versus normal myocardium. The larger albumin-(Gd-DTPA)30 demonstrated minimal extravasation in normal myocardium (FLR .33 per hour); FLR in tumors was 100% higher (.66 per hour, P < .002) and FLR in reperfused capillaries was significantly greater (7.94 per hour, P < .001). Based on capillary permeability measurements, the cascade polymer may have limited utility for detection of mildly increased microvascular permeabilities. For severe tissue injury, the cascade polymer can resolve abnormal microvascular integrity.
Collapse
Affiliation(s)
- H C Roberts
- Department of Radiology, University of California, San Francisco, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Demsar F, Roberts TP, Schwickert HC, Shames DM, van Dijke CF, Mann JS, Saeed M, Brasch RC. A MRI spatial mapping technique for microvascular permeability and tissue blood volume based on macromolecular contrast agent distribution. Magn Reson Med 1997; 37:236-42. [PMID: 9001148 DOI: 10.1002/mrm.1910370216] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A rapid and automated method for two-dimensional spatial depiction (mapping) of quantitative physiological tissue characteristics derived from contrast enhanced MR imaging was developed and tested in disease models of cancer, inflammation, and myocardial reperfusion injury. Specifically, an established two-compartment kinetic model of unidirectional mass transport was implemented on a pixel-by-pixel basis to generate maps of tissue permeability surface area product (PS) and fractional blood volume (BV) based on dynamic MRI intensity data after administration of albumin-(Gd-DTPA)30, a prototype macromolecular contrast medium (MMCM) designed for blood pool enhancement. Maps of PS and BV in disease models of adenocarcinoma, intramuscular abscess inflammation, and myocardial reperfusion injury clearly depicted zones of increased permeability (up to approximately 500 microl/cc/h--compared to <25 microl/cc/h in normal tissues). As revealed on PS maps, the rank ordering of studied permeability abnormalities was reperfusion injury > inflammation > tumors. A rapid, automated mapping technique derived from dynamic contrast-enhanced MRI data can be used to facilitate the identification and characterization of pathophysiologic abnormalities, specifically relative increases in blood volume and/or microvascular permeability.
Collapse
Affiliation(s)
- F Demsar
- Department of Radiology, University of California, San Francisco, USA
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Zhu B, Sun Y, Sievers RE, Shuman JL, Glantz SA, Chatterjee K, Parmley WW, Wolfe CL. L-arginine decreases infarct size in rats exposed to environmental tobacco smoke. Am Heart J 1996; 132:91-100. [PMID: 8701882 DOI: 10.1016/s0002-8703(96)90395-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
This study examined the effects of L-arginine on myocardial infarct size, hemodynamics, and vascular reactivity in environmental tobacco smoke (ETS)-exposed and non-ETS-exposed rats. We previously demonstrated that exposure to ETS increased myocardial infarct size in a rat model of ischemia and reperfusion. If reduced reperfusion was caused by endothelial cell damage and increased vascular tone, L-arginine (ARG) would increase nitric oxide and better protect the heart. Sixty Sprague-Dawley rats were randomly divided into four groups: ETS or non-ETS (control) with and without ARG (2.25% ARG in drinking water). The ETS groups were exposed to passive smoking (4 Marlboro cigarettes per 15 minutes, 6 hours a day) for 6 weeks. After 6 weeks, all rats were subjected to 35 minutes of left coronary artery occlusion and 120 minutes of reperfusion, with hemodynamic monitoring. Aortic rings were harvested to evaluate vascular reactivity. Average air nicotine, carbon monoxide, and total particulate concentrations were 1304 +/- 215 microgram/m3, 78 +/- 2.0 ppm, and 31 +/- .7 mg/m3 (mean +/- SEM) for the ETS-exposed rats. Infarct size (infarct mass/risk area x 100%) increased with ETS exposure but decreased significantly in the ETS-with-ARG group compared with the ETS-without-ARG group (42% +/- 6% vs 64% +/- 6%, mean +/- SEM; p = 0.043). The benefit of ARG was dependent on ETS exposure (ETS x ARG interaction, p = 0.043). There were no significant differences between groups in heart rate, systolic pressure, and rate-pressure product. ARG significantly decreased myocardial infarct size after ischemia and reperfusion in ETS-exposed rats. Neither the adverse effects of ETS on infarct size nor the blockage of this effect by ARG appears to be the result of ETS-induced alterations in hemodynamics.
Collapse
Affiliation(s)
- B Zhu
- Cardiovascular Division, Department of Medicine, University of California, San Francisco, 94143-0124, USA
| | | | | | | | | | | | | | | |
Collapse
|
42
|
Saeed M, Wendland MF, Lauerma K, Sakuma H, Chew W, Derugin N, Higgins CB. First-pass contrast-enhanced inversion recovery and driven equilibrium fast GRE imaging studies: detection of acute myocardial ischemia. J Magn Reson Imaging 1995; 5:515-23. [PMID: 8574034 DOI: 10.1002/jmri.1880050506] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The purpose of this study was (1) to monitor the dynamic effects of T1-enhancing and magnetic susceptibility contrast material on normal canine myocardium using inversion recovery (IR)- and driven equilibrium (DE)-prepared fast gradient-recalled echo (GRE) sequences and (2) to determine the relative value of T1-enhancing and magnetic susceptibility contrast material in detecting regions of ischemia in the same animal. Normal dogs (n = 5) and dogs with acute occlusion of the left anterior descending (LAD) coronary artery (n = 11) were studied using a 1.5-T MR imager. ECG-gated fast IR-prepared GRE images were acquired using TI/TR/TE of 700/7.0/2.9 msec and a flip angle of 7 degrees. Fast DE-prepared GRE images were obtained using a flip angle of 12 degrees and a DE delay/TR/TE of 60/10.2/4.2 msec. Sequential images were acquired to monitor transit of 0.05 mmol/kg gadodiamide injection and 0.2 and 0.4 mmol/kg sprodiamide injection. On slice-nonselective IR fast GRE images, gadodiamide caused significant enhancement of the normal myocardium and the left ventricular (LV) chamber blood. In dogs with LAD occlusion, the ischemic region was defined as an area of low signal intensity (SI). On DE-prepared GRE sequences, administration of sprodiamide resulted in a substantial decrease in signal from normal myocardium and LV chamber blood in normal dogs. In animals subjected to LAD occlusion, this contrast medium produced a transient decrease in SI from normal myocardium (P < .05) and no significant change in SI from ischemic myocardium.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- M Saeed
- Department of Radiology, University of California, San Francisco 94143, USA
| | | | | | | | | | | | | |
Collapse
|
43
|
Su MY, Najafi AA, Nalcioglu O. Regional comparison of tumor vascularity and permeability parameters measured by albumin-Gd-DTPA and Gd-DTPA. Magn Reson Med 1995; 34:402-11. [PMID: 7500880 DOI: 10.1002/mrm.1910340318] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Sequential albumin-Gd-DTPA and Gd-DTPA dynamic enhancement studies were performed in an animal tumor model for the comparison of regional vascularity and permeability parameters measured by these two different sizes of contrast agents. The early albumin-Gd-DTPA enhancement arises from the vascular compartment, and the averaged signal enhancement derived from the first 3 to first 6 images postinjection can be reliably used to assess vascularity. The signal intensity in the images during the period of 5-10 min post-albumin-Gd-DTPA injection shows a steady linear variation. The intercept of the linear relationship is another indicator of the vascularity and the slope represents the tumor permeability to albumin-Gd-DTPA. The Gd-DTPA enhancement study was analyzed by a two-compartmental pharmacokinetic model to calculate the regional vascularity and permeability. The permeability parameters measured from albumin-Gd-DTPA and Gd-DTPA show an excellent correlation. The vascularity parameters measured from albumin-Gd-DTPA show good linear correlation with the low vascularity groups measured by Gd-DTPA, but show saturation for the high vascularity groups. The enhancement mechanisms for both contrast agents are discussed to relate the imaging parameters to the physiological variables.
Collapse
Affiliation(s)
- M Y Su
- Department of Radiological Sciences, University of California, Irvine 92717, USA
| | | | | |
Collapse
|
44
|
Mühler A. Assessment of myocardial perfusion using contrast-enhanced MR imaging: current status and future developments. MAGMA (NEW YORK, N.Y.) 1995; 3:21-33. [PMID: 7600173 DOI: 10.1007/bf02426397] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Excellent inherent tissue contrast is one of the great promises of clinical magnetic resonance (MR) imaging, but functional information is relatively limited. However, MR imaging complemented by the administration of contrast agents can provide such functional assessment. The perfusion status of the myocardium is one of the most important functional information in cardiovascular imaging. Because the clinical acceptance of a contrast agent is measured by its ability to improve patient outcome and to guide therapy, it is unlikely that detection of myocardial infarction, the final stage of ischemic heart disease, should be the target for contrast media development. It would obviously be better if occult regional myocardial perfusion deficits could be reliably detected. The current article was prepared to help the clinical radiologist to keep pace with new strategies for myocardial enhancement and their potential clinical applicability for detection of early perfusion deficits. Several techniques for noninvasive measurement of myocardial perfusion are currently evolving which have the potential to be introduced into routine MR imaging. Most investigators favor a first-pass analysis of the contrast agent bolus through the myocardium using ultrafast sequences. However, such a technique may require clinical introduction of a blood pool agent. There are good reasons to favor T1-weighted sequences over susceptibility imaging in such first-pass studies. In the future, assessment of myocardial perfusion status using contrast-enhanced MR imaging may be done producing perfusion maps with high spatial resolution (e.g., 256 x 128), with sequences available on most scanners without special hardware requirements (e.g., IR-Turboflash, keyhole imaging), and requiring only a short period of time for examination (approximately 3 min).
Collapse
Affiliation(s)
- A Mühler
- Research Laboratories, Schering AG, Berlin, Germany
| |
Collapse
|
45
|
|
46
|
Saeed M, Wendland MF, Yu KK, Lauerma K, Li HT, Derugin N, Cavagna FM, Higgins CB. Identification of myocardial reperfusion with echo planar magnetic resonance imaging. Discrimination between occlusive and reperfused infarctions. Circulation 1994; 90:1492-501. [PMID: 7522135 DOI: 10.1161/01.cir.90.3.1492] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND The current treatment of many cases of acute myocardial infarction involves the use of thrombolytic agents. Evaluation of this therapy requires determination of the success of reperfusion and assessment of the presence and extent of infarction in the reperfused territory. The present study was designed to simulate in rat models several possible outcomes of reperfusion therapy: (1) successful reperfusion and absence of myocardial infarction, (2) successful reperfusion and presence of myocardial infarction, and (3) unsuccessful reperfusion. The usefulness of contrast-enhanced fast magnetic resonance (MR) imaging in defining the success of reperfusion was investigated. The dynamic effects were examined of low and high doses of gadolinium-BOPTA/dimeglumine (Gd-BOPTA/dimeg) on myocardial signal using MR inversion recovery echo planar imaging (IR-EPI) and gradient recalled echo planar imaging (GR-EPI), respectively. METHODS AND RESULTS Rats were subjected to one of the following regimens: reperfused reversible myocardial injury (n = 9), reperfused irreversible myocardial injury (n = 9), and occlusive infarction (n = 9). MR echo planar images were acquired every 1 or 2 seconds before, during, and after administration of Gd-BOPTA/dimeg. In all groups, normal myocardial signal was sharply increased on IR-EPI and decreased on GR-EPI at the peak of the bolus, followed by a gradual decline to baseline. In animals subjected to reperfused reversible myocardial injury, normal and previously ischemic regions were indistinguishable during and after the passage of Gd-BOPTA/dimeg. On the other hand, enhancement of reperfused irreversibly injured myocardium was delayed but increased steadily to a higher level than normal myocardium on IR-EPI. The reperfused irreversibly injured myocardium was identified on IR-EPI as a zone of high signal (hot spot). On GR-EPI, signal loss in reperfused irreversibly injured myocardium was significantly less compared with normally perfused myocardium. In animals with occlusive infarctions, there was no change in signal intensity over the ischemic region on either IR-EPI or GR-EPI. Occlusive infarction was identified as zones of either low (cold spot) or high (hot spot) signal compared with normal myocardium, depending on MR pulse sequence and dose of the contrast medium. CONCLUSIONS The transit of Gd-BOPTA/dimeg monitored by fast MR imaging techniques can be used to distinguish between reperfused reversibly and reperfused irreversibly injured myocardium and between occlusive and reperfused infarctions.
Collapse
Affiliation(s)
- M Saeed
- Department of Radiology, University of California San Francisco 94143
| | | | | | | | | | | | | | | |
Collapse
|
47
|
Abstract
The role of contrast media for quantitative characterization of ischemic myocardial events with magnetic resonance (MR) imaging has advanced considerably in the past few years. Contrast material-enhanced MR imaging is useful for identifying and sizing myocardial infarcts and for distinguishing between occlusive and reperfused myocardial infarcts. Recent results suggest that contrast-enhanced MR imaging can also be used to identify areas of cell death in regions of reperfused myocardial infarction. With the aid of MR contrast media, fast MR imaging techniques may be useful in estimating regional myocardial perfusion. Although no simple relationship between signal intensity and concentration exists, contrast-enhanced MR perfusion imaging can demonstrate the presence and relative severity of hypoperfused myocardium. Combining myocardial perfusion imaging with the anatomic and functional information provided by other MR imaging techniques could make MR imaging a comprehensive noninvasive means of evaluating ischemic cardiac disease.
Collapse
Affiliation(s)
- M Saeed
- Department of Radiology, University of California, San Francisco 94143
| | | | | |
Collapse
|
48
|
de Roos A, van der Wall EE. EVALUATION OF ISCHEMIC HEART DISEASE BY MAGNETIC RESONANCE IMAGING AND SPECTROSCOPY. Radiol Clin North Am 1994. [DOI: 10.1016/s0033-8389(22)00390-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
49
|
Vexler VS, Clément O, Schmitt-Willich H, Brasch RC. Effect of varying the molecular weight of the MR contrast agent Gd-DTPA-polylysine on blood pharmacokinetics and enhancement patterns. J Magn Reson Imaging 1994; 4:381-8. [PMID: 8061437 DOI: 10.1002/jmri.1880040325] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The effects of varying the molecular weight of gadolinium-DTPA (diethylenetriaminepentaacetic acid)-polylysine, a macromolecular magnetic resonance (MR) imaging contrast agent, on blood pharmacokinetics and dynamic tissue MR imaging signal enhancement characteristics were studied in normal rats. Blood elimination half-life, total blood clearance, volume of the central compartment (Vcc) and the steady-state distribution volume (Vssd) were calculated for four Gd-DTPA-polylysine polymers with average molecular weights of 36, 43.9, 139, and 480 kd and compared with corresponding values for Gd-DTPA (0.57 kd) and Gd-DTPA-albumin (92 kd). Blood elimination half-life increased seven-fold with an increase in molecular weight from 36 to 480 kd. The Vcc values for all polylysine polymers did not differ significantly from the Vcc value for Gd-DTPA-albumin but were significantly smaller than the Vcc value for Gd-DTPA. The Vssd value for Gd-DTPA did not differ significantly from the Vssd value for the 36- and 43.9-kd polymers but was significantly larger than the Vssd values for the 139- and 480-kd polymers and for Gd-DTPA-albumin. On T1-weighted coronal spin-echo MR images, dynamic signal enhancement profiles in liver and kidney for the 36-, 43.9-, and 480-kd Gd-DTPA-polylysine chelates corresponded to the blood pharmacokinetic data. Increasing molecular weight of Gd-DTPA-polylysine formulations substantially slows blood clearance and produces a prolonged, almost constant tissue signal enhancement for the 60-minute observation period.
Collapse
Affiliation(s)
- V S Vexler
- Department of Radiology, University of California, San Francisco 94143-0628
| | | | | | | |
Collapse
|
50
|
Zhu BQ, Sievers RE, Sun YP, Morse-Fisher N, Parmley WW, Wolfe CL. Is the reduction of myocardial infarct size by dietary fish oil the result of altered platelet function? Am Heart J 1994; 127:744-55. [PMID: 8154411 DOI: 10.1016/0002-8703(94)90540-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Sprague-Dawley rats fed a diet containing 12% fish oil (18% eicosapentaenoic acid [EPA] and 12% docosahexaenoic acid [DHA]), for 1 week (group I, n = 9) or 8 weeks (group III, n = 42) and controls (group II, n = 8; group IV, n = 36, respectively) were subjected to 35 minutes of left coronary artery occlusion followed by 120 minutes of reperfusion. Compared to the controls, infarct size was significantly reduced in group III (15% +/- 2%, n = 42 vs 34% +/- 4%, n = 36; p < 0.001; infarct mass/risk area x 100%), but no change in group I (39% +/- 5%, n = 9 vs 35% +/- 5%, n = 8; p = not significant). Bleeding time was prolonged in group III (290 +/- 73 sec) compared to group IV (99 +/- 10 sec, p = 0.015). Omega-3 fatty acid (EPA and DHA) levels in platelets were significantly higher in the rats fed 8 weeks of fish oil (group III) compared to the controls (group IV) and the rats fed 8 weeks of fish oil and then a regular diet until bleeding time normalized (group V) (7.2% +/- 0.6% vs 1.2% +/- 0.2% and 4.9% +/- 0.5%; 3.8% +/- 0.7% vs 1.8% +/- 0.3% and 2.8% +/- 0.6%, p < 0.001 and 0.05, respectively). These data indicate that long-term (8 weeks) dietary fish oil supplementation significantly reduces infarct size; short-term (1 week) does not. This reduction of infarct size appears to correlate with altered platelet function and EPA and DHA levels in platelets.
Collapse
Affiliation(s)
- B Q Zhu
- Department of Medicine, University of California, San Francisco
| | | | | | | | | | | |
Collapse
|