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Sturek M, Mokelke EA, Sindermann JR, Adam LP, March KL. Molecular and Cellular Physiology of Differentiated Vascular Smooth Muscle. CARDIOVASCULAR MEDICINE 2007. [DOI: 10.1007/978-1-84628-715-2_72] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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2
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Affiliation(s)
- Ban-An Khaw
- School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Mugar Building, 360 Huntington Avenue, Boston, MA 02115, USA
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3
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Varghese T, Zagzebski JA, Rahko P, Breburda CS. Ultrasonic imaging of myocardial strain using cardiac elastography. ULTRASONIC IMAGING 2003; 25:1-16. [PMID: 12747424 DOI: 10.1177/016173460302500101] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Clinical assessment of myocardial ischemia based on visually-assessed wall motion scoring from echocardiography is semiquantitative, operator dependent, and heavily weighted by operator experience and expertise. Cardiac motion estimation methods such as tissue Doppler imaging, used to assess myocardial muscle velocity, provides quantitative parameters such as the strain-rate and strain derived from Doppler velocity. However, tissue Doppler imaging does not differentiate between active contraction and simple rotation or translation of the heart wall, nor does it differentiate tethering (passively following) tissue from active contraction. In this paper, we present a strain imaging modality called cardiac elastography that provides two-dimensional strain information. A method for obtaining and displaying both directional and magnitude cardiac elastograms and displaying strain over the entire cross-section of the heart is described. Elastograms from a patient with coronary artery disease are compared with those from a healthy volunteer. Though observational, the differences suggest that cardiac elastography may be a useful tool for assessment of myocardial function. The method is two-dimensional, real time and avoids the disadvantage of observer-dependent judgment of myocardial contraction and relaxation estimated from conventional echocardiography.
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Affiliation(s)
- Tomy Varghese
- Department of Medical Physics, The University of Wisconsin-Madison Madison, WI 53706, USA.
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5
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D'Alonzo AJ, Zhu JL, Darbenzio RB. Effects of class III antiarrhythmic agents in an in vitro rabbit model of spontaneous torsades de pointe. Eur J Pharmacol 1999; 369:57-64. [PMID: 10204682 DOI: 10.1016/s0014-2999(99)00057-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Acquired long QT syndrome develops as a result of pharmacological interventions that prolong action potential duration. Excessive action potential prolongation may lead to torsade de pointes, a potentially fatal arrhythmia. To study this arrhythmia, in vivo models have been developed, but are difficult to interpret due to the complex nature of the intact metabolic, nervous and humoral systems. To more clearly examine the propensity of various Class III agents to elicit torsades de pointe, an in vitro model of spontaneous torsades de pointe was used in isolated perfused rabbit hearts. Male New Zealand white rabbits were anesthetized with sodium pentobarbital, and hearts isolated and perfused in a Langendorff apparatus. Electrocardiogram and epicardial monophasic action potentials were continuously recorded, and methoxamine (30 nM) and acetylcholine (0.3 microM) were given throughout the experiment. After 10 min of methoxamine and acetylcholine perfusion, Class III agents, dofetilide (0.1 to 0.7 microM), E-4031 (0.1 to 0.5 microM), D-sotalol (10 to 30 microM), or clofilium (0.1 to 0.3 microM), were given. All agents, except D-sotalol, induced torsades de pointe in 100% of hearts tested. D-Sotalol (30 microM) elicited a low incidence of torsades de pointe (25%). This could be explained by the limited prolongation of action potential duration with D-sotalol as compared to other Class III agents under these conditions. Dofetilide, a selective Class III agent, alone did not induce torsades de pointe. Nadolol (3 microM), a beta-adrenoceptor antagonist, increased the propensity of dofetilide to elicit torsades de pointe. In conclusion, increases in action potential duration (i.e., using Class III agents) in combination with a low heart rate (muscarinic receptor stimulation) and increases in intracellular Ca2+ (alpha-adrenoceptor stimulation) are needed to develop torsades de pointe in this model. Modulating these systems may provide us with new insights into preventing the initiation or maintenance of this arrhythmia.
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Affiliation(s)
- A J D'Alonzo
- Bristol-Myers Squibb Pharmaceutical Research Institute, Department of Cardiovascular Pharmacology, Princeton, NJ 08543-4000, USA
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6
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Elmaleh DR, Narula J, Babich JW, Petrov A, Fischman AJ, Khaw BA, Rapaport E, Zamecnik PC. Rapid noninvasive detection of experimental atherosclerotic lesions with novel 99mTc-labeled diadenosine tetraphosphates. Proc Natl Acad Sci U S A 1998; 95:691-5. [PMID: 9435254 PMCID: PMC18482 DOI: 10.1073/pnas.95.2.691] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The development of a noninvasive imaging procedure for identifying atherosclerotic lesions is extremely important for the clinical management of patients with coronary artery and peripheral vascular disease. Although numerous radiopharmaceuticals have been proposed for this purpose, none has demonstrated the diagnostic accuracy required to replace invasive angiography. In this report, we used the radiolabeled purine analog, 99mTc diadenosine tetraphosphate (Ap4A; AppppA, P1,P4-di(adenosine-5')-tetraphosphate) and its analogue 99mTc AppCHClppA for imaging experimental atherosclerotic lesions in New Zealand White rabbits. Serial gamma camera images were obtained after intravenous injection of the radiolabeled dinucleotides. After acquiring the final images, the animals were sacrificed, ex vivo images of the aortas were recorded, and biodistribution was measured. 99mTc-Ap4A and 99mTc AppCHClppA accumulated rapidly in atherosclerotic abdominal aorta, and lesions were clearly visible within 30 min after injection in all animals that were studied. Both radiopharmaceuticals were retained in the lesions for 3 hr, and the peak lesion to normal vessel ratio was 7.4 to 1. Neither of the purine analogs showed significant accumulation in the abdominal aorta of normal (control) rabbits. The excised aortas showed lesion patterns that were highly correlated with the in vivo and ex vivo imaging results. The present study demonstrates that purine receptors are up-regulated in experimental atherosclerotic lesions and 99mTc-labeled purine analogs have potential for rapid noninvasive detection of plaque formation.
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Affiliation(s)
- D R Elmaleh
- Department of Radiology, Massachusetts General Hospital, Boston, USA
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7
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Khaw BA, Carrio I, Pieri PL, Narula J. Radionuclide Imaging of the Synthetic Smooth Muscle Cell Phenotype in Experimental Atherosclerotic Lesions. Trends Cardiovasc Med 1996; 6:226-32. [DOI: 10.1016/s1050-1738(96)00093-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Walker JD, Crawford FA, Mukherjee R, Spinale FG. The direct effects of 3,5,3'-triiodo-L-thyronine (T3) on myocyte contractile processes. Insights into mechanisms of action. J Thorac Cardiovasc Surg 1995; 110:1369-79; discussion 1379-80. [PMID: 7475189 DOI: 10.1016/s0022-5223(95)70060-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Administration of 3,5,3'-triiodo-L-thyronine (T3) has recently been suggested to acutely improve left ventricular performance. However, the cellular and molecular mechanisms responsible for this improvement in left ventricular function with T3 remained unknown. Accordingly, the present study examined the direct effects of T3 administration on myocyte contractile function and the sarcolemmal systems that might potentially contribute to these effects. In isolated porcine left ventricular myocytes (n = 81), velocity of shortening increased in the presence of 80 pmol/L T3 compared with that in untreated myocytes (117.0 +/- 5.0 versus 77.3 +/- 3.3 microns/sec, p < 0.05). In a separate series of experiments (n = 29), myocyte velocity of shortening increased in the presence of both T3 and beta-adrenergic receptor stimulation (25 nmol/L isoproterenol) to greater than that with beta-adrenergic receptor stimulation alone (274.3 +/- 16.9 versus 203.7 +/- 16.2 microns/sec, p < 0.05). Cyclic adenosine monophosphate generation was next examined in isolated myocyte preparations (n = 9). In the presence of T3, no significant increase in cyclic-adenosine monophosphate generation was observed compared with that in untreated myocytes (39.1 +/- 8.3 versus 24.7 +/- 5.8 fmols/myocyte, p = 0.17). However, in the presence of both T3 and beta-adrenergic receptor stimulation, cyclic-adenosine monophosphate generation increased significantly to greater than that with beta-adrenergic receptor stimulation alone (224.4 +/- 61.1 versus 120.1 +/- 35.5 fmoles/myocyte, p < 0.05). Because cyclic-adenosine monophosphate modulates intracellular Ca2+ processes, L-type Ca+2 channel current (patch clamp methods; -picoamp/picofarad, n = 15) and peak intracellular Ca+2 levels (fura 2 ionic measurement, n = 47) were next measured. In the presence of T3, a shift in the activation voltage at peak L-type Ca+2 channel current was observed from baseline (5.5 +/- 1.4 versus 9.0 +/- 1.0 mV, p < 0.05). Furthermore, in the presence of both T3 and beta-adrenergic receptor stimulation, peak L-type Ca+2 channel current (8.9 +/- 0.7 versus 6.3 +/- 1.0 mV, p < 0.05) and peak intracellular Ca+2 levels (189.9 +/- 8.4 versus 171.7 +/- 8.3 nmol/L, p < 0.05) increased compared with values obtained with beta-adrenergic receptor stimulation alone. Important findings from the present study were twofold: (1) T3 improved myocyte contractile processes through a cyclic-adenosine monophosphate-independent mechanism and (2) T3 potentiated the effects of beta-adrenergic receptor stimulation transduction by increasing cyclic-adenosine monophosphate production, L-type Ca+2 channel current, and Ca+2 availability to the myocyte contractile apparatus.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- J D Walker
- Division of Cardiothoracic Surgery, Medical University of South Carolina, Charleston 29425, USA
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Narula J, Petrov A, Bianchi C, Ditlow CC, Lister BC, Dilley J, Pieslak I, Chen FW, Torchilin VP, Khaw BA. Noninvasive localization of experimental atherosclerotic lesions with mouse/human chimeric Z2D3 F(ab')2 specific for the proliferating smooth muscle cells of human atheroma. Imaging with conventional and negative charge-modified antibody fragments. Circulation 1995; 92:474-84. [PMID: 7634463 DOI: 10.1161/01.cir.92.3.474] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND A murine monoclonal antibody designated Z2D3 (IgM) generated against homogenized human atherosclerotic plaques was demonstrated to be highly specific for proliferating smooth muscle cells. The primary clone subsequently was genetically engineered to provide a mouse/human chimeric antibody with human IgG1 constant region expressed in a rat myeloma cell line. The resulting Z2D3-73.30 chimeric retained the immunoreactivity relative to the parent Z2D3-IgM and was pepsin-digested to yield F(ab')2. 111In-labeled chimeric Z2D3 F(ab')2 was then used for noninvasive imaging of experimental atherosclerotic lesions. To improve the imaging characteristics, we modified chimeric Z2D3 F(ab')2 fragments to carry a high negative charge. Improved visualization of targets with 111In-labeled, negatively charged, polymer-modified antibodies most probably is the result of faster blood clearance and a decrease in nontarget background activity. METHODS AND RESULTS Experimental atherosclerotic lesions were induced in rabbits by deendothelialization of the infradiaphragmatic aorta followed by a 6% peanut oil-2% cholesterol diet. After 12 weeks, localization of the conventionally labeled 111In-Z2D3 F(ab')2 (24 Mbq [650 microCi]/500 to 750 micrograms) (n = 4) was compared with 111In-labeled, negatively charged, polymer-modified Z2D3 F(ab')2 (24 Mbq [650 microCi]/25 to 50 micrograms) in eight atherosclerotic rabbits. Three control rabbits also received radiolabeled polymer-modified Z2D3. Ten rabbits with atherosclerotic lesions received 111In-labeled nonspecific human IgG1 F(ab')2 with (n = 6) or without (n = 4) negative charge modification. Atherosclerotic lesions were visualized in all rabbits with the conventional Z2D3 F(ab')2 at 48 hours. However, unequivocal lesion visualization was possible at 24 hours only with negatively charged, polymer-modified Z2D3 F(ab')2. Quantitative uptake of F(ab')2 fragments was essentially determined by the presence of atherosclerotic lesions (F1.37 = 69.8; P < .0001) and the specificity of the antibody (F1.37 = 36.6; P < .0001). Uptake of the conventional Z2D3 in atherosclerotic lesions (mean +/- SEM percent injected dose per gram, 0.112 +/- 0.024%) was six times higher than background activity in the normal aortic segments (nondenuded thoracic aorta; mean percent injected dose per gram, 0.019 +/- 0.003%). Uptake of the conventional Z2D3 was also significantly higher than that of nonspecific human IgG1 F(ab')2 (0.027 +/- 0.004%). Specific uptake of the conventional Z2D3 in the lesions was comparable to the charge-modified Z2D3 uptake (0.084 +/- 0.017; P = .20). Uptake of negative charge-modified Z2D3 in the lesions was significantly higher than in the corresponding background activity in normal thoracic aorta (0.021 +/- 0.002). Uptake of negative charge-modified Z2D3 F(ab')2 in the lesions was higher than the uptake of negative charge-modified nonspecific IgG1 F(ab')2 (0.020 +/- 0.002) in the lesions. Uptake of charge-modified Z2D3 in the atherosclerotic lesions was also significantly higher than the corresponding regions of the aorta of the control rabbits (0.017 +/- 0.002; F1.18 = 27.9; P = .0001). There was, however, no difference in the specific lesion uptake of negative charge-modified Z2D3 at 24 hours (0.079 +/- 0.014) and 48 hours (0.084 +/- 0.0017; P = .99) after intravenous administration. Nontarget organ activities were lower with negative charge-modified 111In-labeled Z2D3 F(ab')2 than with the conventional Z2D3 F(ab')2. Mean kidney activity was fourfold less with the modified (0.45 +/- 0.06) than with the conventionally radiolabeled (1.67 +/- 0.264; P = .001) Z2D3 F(ab')2.
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Affiliation(s)
- J Narula
- Center for Drug Targeting and Analysis, Northeastern University, Boston, Mass., USA
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11
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Wattiaux-De Coninck S, Wattiaux R. Ischemic effects on the structure and function of the plasma membrane. Subcell Biochem 1994; 22:361-402. [PMID: 8146887 DOI: 10.1007/978-1-4615-2401-4_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- S Wattiaux-De Coninck
- Laboratoire de Chimie Physiologique, Facultés Universitaires Notre-Dame de la Paix, Namur, Belgium
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Fuster V, Badimon L, Badimon JJ, Chesebro JH. The pathogenesis of coronary artery disease and the acute coronary syndromes (1). N Engl J Med 1992; 326:242-50. [PMID: 1727977 DOI: 10.1056/nejm199201233260406] [Citation(s) in RCA: 1992] [Impact Index Per Article: 62.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- V Fuster
- Cardiac Unit, Massachusetts General Hospital, Boston 02114
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Meuse AJ, Perreault CL, Morgan JP. Pathophysiology of cardiac hypertrophy and failure of human working myocardium: abnormalities in calcium handling. Basic Res Cardiol 1992; 87 Suppl 1:223-33. [PMID: 1323261 DOI: 10.1007/978-3-642-72474-9_18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Abnormal intracellular calcium ([Ca2+]i) handling appears to be a major cause of both systolic and diastolic dysfunction in animals and human beings with hypertrophy and/or heart failure. We utilized the bioluminescent calcium indicator aequorin to examine the cyclical variations in intracellular calcium levels during isometric contractions. Studies of ventricular muscle from patients with end-stage heart failure exhibited three physiologic findings not seen in preparations taken from normal hearts including: 1) abnormalities in calcium handling; 2) deficient production of cyclic AMP; and 3) a reversed force-frequency relationship. These observations have important implications with regard to the pathogenesis and therapeutics of heart failure in man.
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Affiliation(s)
- A J Meuse
- Charles A. Dana Research Institute, Harvard-Thorndike Laboratory, Boston, Massachusetts
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Affiliation(s)
- R Roberts
- Department of Medicine, Baylor College of Medicine, Houston, Texas
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16
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Abstract
Early studies in whole heart indicated that cGMP antagonized the positive inotropic effects of catecholamines and cAMP. However, the regulation of cGMP levels by a variety of agents was not always consistent with their effects on contractility. It is now clear that at least two major cell types in whole heart, cardiac myocytes and vascular smooth muscle cells, differ markedly in their mechanisms of cGMP regulation and response to cGMP. Furthermore, experiments on isolated cardiac myocytes indicate that the mechanism of cGMP action even in this single cell type can be multifaceted. Cyclic GMP inhibits the L-type calcium channel current (ICa), which is the major source of Ca++ entry into heart cells, and which plays a predominant role in the initiation and regulation of cardiac electrical and contractile activities. Patch-clamp measurements of ICa indicate that in isolated frog myocytes cGMP inhibits ICa by stimulation of cAMP phosphodiesterase (cGS-PDE), whereas in purified rat ventricular myocytes, cGMP predominantly inhibits ICa via a mechanism involving cGMP-dependent protein kinase (cGMP-PK). Under certain conditions, cGMP can also inhibit a cGMP-inhibited cAMP phosphodiesterase (cGI-PDE) and thereby produce a stimulatory effect on ICa. Biochemical characterization of the endogenous PDEs and cGMP-PK in purified cardiac myocytes provided further evidence in support of these mechanisms of cGMP action on ICa.
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Hathaway DR, March KL, Lash JA, Adam LP, Wilensky RL. Vascular smooth muscle. A review of the molecular basis of contractility. Circulation 1991; 83:382-90. [PMID: 1991362 DOI: 10.1161/01.cir.83.2.382] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- D R Hathaway
- Department of Medicine, Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis 46223
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Abstract
Myocardial ischemia is a disease process characterized by reduced coronary flow such that the supply of nutritive blood to heart muscle (myocardium) is insufficient for normal myocardial aerobic metabolism. Prompt reestablishment of coronary flow by invasive and noninvasive clinical procedures is the most direct and effective means of limiting myocardial damage in ischemic heart disease patients, although reperfusion carries with it an injury component which may reflect, at least to some degree, the toxic effects of partially reduced oxygen species and their participation in degenerative cellular processes such as membrane lipid peroxidation. Vitamin E, a lipophilic, chain-breaking antioxidant, is a prominent membrane constituent in heart muscle, where it modulates/regulates various aspects of heart muscle-cell metabolism and function. Vitamin E's beneficial effects against experimentally induced oxidative damage to the heart, along with inverse epidemiological correlations between plasma vitamin E level and either anginal pain or mortality due to ischemic heart disease, suggest that vitamin E might have protective and therapeutic roles against myocardial ischemic-reperfusion injury. Laboratory investigations aimed at addressing this possibility have demonstrated that vitamin E supplementation protects isolated hearts against ischemic-reperfusion injury, and relatively more inconsistent and limited data document cardioprotective effects of vitamin E in some animal models of myocardial ischemia-reperfusion, especially when administered prior to the ischemic period. Clinical attempts to establish whether vitamin E has therapeutic benefit in ischemic heart disease patients remain inconclusive, having relied upon a variety of nonuniformly controlled protocols and a single, rather subjective endpoint (anginal pain). Consequently, although laboratory data constitute a conceptual context for and indirect support of the idea that vitamin E could be a cardioprotectant against ischemic-reperfusion injury, compelling clinical evidence regarding vitamin E's therapeutic potential in the ischemic heart-disease patient is lacking. Elective coronary revascularization would appear to provide an attractive clinical setting for evaluating the therapeutic efficacy of vitamin E in the context of cardiac ischemia-reperfusion. Further biochemical work would still be required to define how vitamin E exerts any cardioprotective effect observed in these patients.
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Affiliation(s)
- D R Janero
- Research Department, CIBA-GEIGY Corporation, Summit, NJ 07901
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Williams RS. Molecular biology in cardiology: recent developments and opportunities for clinical applications. Am J Med Sci 1990; 300:304-10. [PMID: 2240019 DOI: 10.1097/00000441-199011000-00007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The revolution in molecular biology that has taken place in the last decade has provided powerful research methods that are changing our understanding of cardiovascular physiology and disease. This editorial commentary will highlight several areas of current research activity within the broad and expanding field of molecular cardiology, with a special emphasis on prospects for clinical applications in cardiovascular medicine.
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Affiliation(s)
- R S Williams
- Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710
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Wagner BM. Dynamic Pathology of the Heart, A Personal Odyssey. Toxicol Pathol 1990. [DOI: 10.1177/0192623390004part_106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Bernard M. Wagner
- Deputy Director, Nathan Kline Institute Research
Professor, Department of Pathology, New York University School of Medicine,
Orangeburg, New York
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