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Virk ZM, Richardson TL, Nowatzke JF, Ullah A, Pedrotty DM, Shoemaker MB, Kanagasundram A, Roden DM, Stevenson WG. Cardiac Sarcoidosis and a Likely Pathogenic TTN Variant in a Patient Presenting With Ventricular Tachycardia. JACC Case Rep 2023; 16:101878. [PMID: 37396334 PMCID: PMC10313492 DOI: 10.1016/j.jaccas.2023.101878] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 04/12/2023] [Accepted: 04/20/2023] [Indexed: 07/04/2023]
Abstract
Rare variants in TTN are the most common monogenic cause of early-onset atrial fibrillation and dilated cardiomyopathy. Whereas cardiac sarcoidosis is very underdiagnosed, a common presentation can be ventricular arrhythmias. This report presents a patient with a likely pathogenic TTN variant and cardiac sarcoidosis. (Level of Difficulty: Intermediate.).
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Affiliation(s)
- Zain M. Virk
- Vanderbilt University Medical Center, Department of Medicine Division of Cardiology, Nashville, Tennessee, USA
| | - T. Lee Richardson
- Vanderbilt University Medical Center, Department of Medicine Division of Cardiology, Nashville, Tennessee, USA
| | - Joseph F. Nowatzke
- Vanderbilt University Medical Center, Department of Medicine Division of Cardiology, Nashville, Tennessee, USA
| | - Asad Ullah
- Vanderbilt University Medical Center, Department of Pathology, Nashville, Tennessee, USA
| | - Dawn M. Pedrotty
- Vanderbilt University Medical Center, Department of Medicine Division of Cardiology, Nashville, Tennessee, USA
| | - M. Benjamin Shoemaker
- Vanderbilt University Medical Center, Department of Medicine Division of Cardiology, Nashville, Tennessee, USA
| | - Arvindh Kanagasundram
- Vanderbilt University Medical Center, Department of Medicine Division of Cardiology, Nashville, Tennessee, USA
| | - Dan M. Roden
- Vanderbilt University Medical Center, Department of Medicine Division of Cardiology, Nashville, Tennessee, USA
| | - William G. Stevenson
- Vanderbilt University Medical Center, Department of Medicine Division of Cardiology, Nashville, Tennessee, USA
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Zyl M, Pedrotty DM, Karabulut E, Kuzmenko V, Sämfors S, Livia C, Vaidya V, Sugrue A, McLeod CJ, Behfar A, Asirvatham SJ, Gatenholm P, Kapa S. Injectable conductive hydrogel restores conduction through ablated myocardium. J Cardiovasc Electrophysiol 2020; 31:3293-3301. [DOI: 10.1111/jce.14762] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 08/18/2020] [Accepted: 08/28/2020] [Indexed: 12/23/2022]
Affiliation(s)
- Martin Zyl
- Department of Cardiovascular Medicine Mayo Clinic College of Medicine and Science Rochester Minnesota USA
| | - Dawn M. Pedrotty
- Division of Cardiology, Department of Medicine Hospital of the University of Pennsylvania Philadelphia Pennsylvania USA
| | - Erdem Karabulut
- Department of Chemistry and Chemical Engineering, 3D Bioprinting and Wallenberg Wood Science Center Chalmers University Gothenburg Sweden
| | - Volodymyr Kuzmenko
- Department of Microtechnology and Nanoscience, Wallenberg Wood Science Center Chalmers University Gothenburg Sweden
| | - Sanna Sämfors
- Department of Chemistry and Chemical Engineering, 3D Bioprinting and Wallenberg Wood Science Center Chalmers University Gothenburg Sweden
| | - Christopher Livia
- Department of Cardiovascular Medicine Mayo Clinic College of Medicine and Science Rochester Minnesota USA
| | - Vaibhav Vaidya
- Department of Cardiovascular Medicine Mayo Clinic College of Medicine and Science Rochester Minnesota USA
| | - Alan Sugrue
- Department of Cardiovascular Medicine Mayo Clinic College of Medicine and Science Rochester Minnesota USA
| | - Christopher J. McLeod
- Department of Cardiovascular Medicine Mayo Clinic College of Medicine and Science Rochester Minnesota USA
| | - Atta Behfar
- Department of Cardiovascular Medicine Mayo Clinic College of Medicine and Science Rochester Minnesota USA
| | - Samuel J. Asirvatham
- Department of Cardiovascular Medicine Mayo Clinic College of Medicine and Science Rochester Minnesota USA
| | - Paul Gatenholm
- Department of Chemistry and Chemical Engineering, 3D Bioprinting and Wallenberg Wood Science Center Chalmers University Gothenburg Sweden
- Cellheal Sandvika Norway
| | - Suraj Kapa
- Department of Cardiovascular Medicine Mayo Clinic College of Medicine and Science Rochester Minnesota USA
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3
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Chao CJ, DeValeria PA, Sen A, Lee H, Pedrotty DM, Patel B, Arsanjani R, Naqvi TZ. Reversible cardiac dysfunction in severe COVID-19 infection, mechanisms and case report. Echocardiography 2020; 37:1465-1469. [PMID: 32856328 PMCID: PMC7461431 DOI: 10.1111/echo.14807] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/01/2020] [Accepted: 07/16/2020] [Indexed: 01/19/2023] Open
Abstract
A previously healthy 49-year-old male patient presented with COVID-19 infection and required mechanical ventilation and extracorporeal membrane oxygenation due to severe hypoxemia. Echocardiography showed cardiac dysfunction with an apical sparing strain pattern, which rapidly normalized within a week. Apical sparing myocardial strain in patients with COVID-19 infection may suggest reverse-type stress cardiomyopathy.
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Affiliation(s)
- Chieh-Ju Chao
- Department of Cardiovascular Diseases, Mayo Clinic, Scottsdale, AZ, USA
| | | | - Ayan Sen
- Department of Critical Care Medicine, Mayo Clinic, Scottsdale, AZ, USA
| | - Hong Lee
- Department of Cardiovascular Diseases, Mayo Clinic, Scottsdale, AZ, USA
| | - Dawn M Pedrotty
- Department of Cardiovascular Diseases, Mayo Clinic, Scottsdale, AZ, USA
| | - Bhavesh Patel
- Department of Critical Care Medicine, Mayo Clinic, Scottsdale, AZ, USA
| | - Reza Arsanjani
- Department of Cardiovascular Diseases, Mayo Clinic, Scottsdale, AZ, USA
| | - Tasneem Z Naqvi
- Department of Cardiovascular Diseases, Mayo Clinic, Scottsdale, AZ, USA
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Borlaug BA, Schaff HV, Pochettino A, Pedrotty DM, Asirvatham SJ, Abel MD, Carter RE, Mauermann WJ. Pericardiotomy Enhances Left Ventricular Diastolic Reserve With Volume Loading in Humans. Circulation 2019; 138:2295-2297. [PMID: 30571519 DOI: 10.1161/circulationaha.118.036006] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Barry A Borlaug
- Departments of Cardiovascular Medicine (B.A.B., D.M.P., S.J.A.), Mayo Clinic, Rochester, MN
| | | | | | - Dawn M Pedrotty
- Departments of Cardiovascular Medicine (B.A.B., D.M.P., S.J.A.), Mayo Clinic, Rochester, MN
| | - Samuel J Asirvatham
- Departments of Cardiovascular Medicine (B.A.B., D.M.P., S.J.A.), Mayo Clinic, Rochester, MN
| | - Martin D Abel
- Anesthesiology (M.D.A., W.J.M.), Mayo Clinic, Rochester, MN
| | - Rickey E Carter
- Health Sciences Research (R.E.C.), Mayo Clinic, Rochester, MN
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Pedrotty DM, Kuzmenko V, Karabulut E, Sugrue AM, Livia C, Vaidya VR, McLeod CJ, Asirvatham SJ, Gatenholm P, Kapa S. Three-Dimensional Printed Biopatches With Conductive Ink Facilitate Cardiac Conduction When Applied to Disrupted Myocardium. Circ Arrhythm Electrophysiol 2019; 12:e006920. [DOI: 10.1161/circep.118.006920] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Dawn M. Pedrotty
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN (D.M.P., A.M.S., C.L., V.R.V., C.J.M., S.J.A., S.K.)
- Division of Cardiovascular Medicine, Department of Medicine, University of Pennsylvania, Philadelphia (D.M.P.)
| | - Volodymyr Kuzmenko
- Department of Microtechnology (V.K.), Nanoscience and Wallenberg Wood Science Center, Chalmers University, Gothenburg, Sweden
| | - Erdem Karabulut
- Department of Chemistry and Chemical Engineering (E.K., P.G.), Nanoscience and Wallenberg Wood Science Center, Chalmers University, Gothenburg, Sweden
| | - Alan M. Sugrue
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN (D.M.P., A.M.S., C.L., V.R.V., C.J.M., S.J.A., S.K.)
| | - Christopher Livia
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN (D.M.P., A.M.S., C.L., V.R.V., C.J.M., S.J.A., S.K.)
| | - Vaibhav R. Vaidya
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN (D.M.P., A.M.S., C.L., V.R.V., C.J.M., S.J.A., S.K.)
| | - Christopher J. McLeod
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN (D.M.P., A.M.S., C.L., V.R.V., C.J.M., S.J.A., S.K.)
| | - Samuel J. Asirvatham
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN (D.M.P., A.M.S., C.L., V.R.V., C.J.M., S.J.A., S.K.)
| | - Paul Gatenholm
- Department of Chemistry and Chemical Engineering (E.K., P.G.), Nanoscience and Wallenberg Wood Science Center, Chalmers University, Gothenburg, Sweden
- CELLHEAL, Blacksburg, VA (P.G.)
| | - Suraj Kapa
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN (D.M.P., A.M.S., C.L., V.R.V., C.J.M., S.J.A., S.K.)
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Affiliation(s)
- Dawn M Pedrotty
- From the Cardiovascular Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Mariell Jessup
- From the Cardiovascular Division, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia.
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Sabesan VJ, Pedrotty DM, Urbaniak JR, Ghareeb GM, Aldridge JM. Free vascularized fibular grafting preserves athletic activity level in patients with osteonecrosis. J Surg Orthop Adv 2013; 21:242-5. [PMID: 23327850 DOI: 10.3113/jsoa.2012.0242] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Athletic patients with osteonecrosis of the femoral head have few desirable therapeutic options that preserve athletic ability. Because these patients are usually young and healthy, any procedure that avoids total hip arthroplasty would be most desirable. This study prospectively evaluated 15 patients (19 hips) who presented with an average age of 28.5 (range, 12 to 46) years and stages 2 (6/19), 3 (2/19), 4 (9/19), and 5 (2/19) of osteonecrosis of the femoral head. All patients were treated with free vascularized fibular autografting (FVFG) to the femoral head. Postoperative evaluations of pain symptoms and functional activity showed improvements in all patients. The average follow-up time was 8 years. Harris hip scores significantly increased from an average preoperative score of 75.3 to an average postoperative score of 94.8. Seventy-five percent of patients were able to return to their sport after recovery and all patients reported being satisfied with the procedure and would repeat their decision to have surgery. Three patients' hips were converted to arthroplasty at 3, 11, and 17 years post-FVFG. The results demonstrate that FVFG is a successful therapeutic treatment in athletes with osteonecrosis of the femoral head. It reduces pain, increases activity, and allows most patients to return to their sport, an achievement often not possible with other treatment options.
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Affiliation(s)
- Vani J Sabesan
- Department of Orthopaedic Surgery,Western Michigan University School of Medicine, Kalamazoo, MI 49008, USA.
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Abstract
Transcriptomics is the study of how our genes are regulated and expressed in different biological settings. Technical advances now enable quantitative assessment of all expressed genes (ie, the entire "transcriptome") in a given tissue at a given time. These approaches provide a powerful tool for understanding complex biological systems and for developing novel biomarkers. This chapter will introduce basic concepts in transcriptomics and available technologies for developing transcriptomic biomarkers. We will then review current and emerging applications in cardiovascular medicine.
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Affiliation(s)
- Dawn M Pedrotty
- Penn Cardiovascular Institute and Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Pedrotty DM, Klinger RY, Kirkton RD, Bursac N. Cardiac fibroblast paracrine factors alter impulse conduction and ion channel expression of neonatal rat cardiomyocytes. Cardiovasc Res 2009; 83:688-97. [PMID: 19477968 DOI: 10.1093/cvr/cvp164] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
AIMS The pathological proliferation of cardiac fibroblasts (CFs) in response to heart injury results in fibrosis, which correlates with arrhythmia generation and heart failure. Here we systematically examined the effect of fibroblast-derived paracrine factors on electrical propagation in cardiomyocytes. METHODS AND RESULTS Neonatal rat cardiac monolayers were exposed for 24 h to media conditioned by CFs. Optical mapping, sharp microelectrode recordings, quantitative RT-PCR, and immunostaining were used to assess the changes in the propagation and shape of the action potential and underlying changes in gene and protein expression. The fibroblast paracrine factors produced a 52% reduction in cardiac conduction velocity, a 217% prolongation of action potential duration, a 64% decrease of maximum capture rate, a 21% increase in membrane resting potential, and an 80% decrease of action potential upstroke velocity. These effects were dose dependent and partially reversible with removal of the conditioned media. No fibroblast proliferation, cardiomyocyte apoptosis, or decreased connexin-43 expression, phosphorylation, and function were found in conditioned cardiac cultures. In contrast, the expression of the fast sodium, inward rectifying potassium, and transient outward potassium channels were, respectively, reduced 3.8-, 6.6-fold, and to undetectable levels. The expression of beta-myosin heavy chain increased 17.4-fold. No electrophysiological changes were observed from media conditioned by CFs in the presence of cardiomyocytes. CONCLUSION Paracrine factors from neonatal CFs alone produced significant electrophysiological changes in neonatal rat cardiomyocytes resembling those found in several cardiac pathologies.
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Affiliation(s)
- Dawn M Pedrotty
- Biomedical Engineering Department, Duke University, Hudson Hall 136, Durham, NC 27708, USA
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10
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Pedrotty DM, Klinger RY, Badie N, Hinds S, Kardashian A, Bursac N. Structural coupling of cardiomyocytes and noncardiomyocytes: quantitative comparisons using a novel micropatterned cell pair assay. Am J Physiol Heart Circ Physiol 2008; 295:H390-400. [PMID: 18502901 DOI: 10.1152/ajpheart.91531.2007] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Well-controlled studies of the structural and functional interactions between cardiomyocytes and other cells are essential for understanding heart pathophysiology and for the further development of safe and efficient cell therapies. We established a novel in vitro assay composed of a large number of individual micropatterned cell pairs with reproducible shape, size, and region of cell-cell contact. This assay was applied to quantify and compare the frequency of expression and distribution of electrical (connexin43) and mechanical (N-cadherin) coupling proteins in 5,000 cell pairs made of cardiomyocytes (CMs), cardiac fibroblasts (CFs), skeletal myoblasts (SKMs), and mesenchymal stem cells (MSCs). We found that for all cell pair types, side-side contacts between two cells formed 4.5-14.3 times more often than end-end contacts. Both connexin43 and N-cadherin were expressed in all homotypic CM pairs but in only 13.4-91.6% of pairs containing noncardiomyocytes, where expression was either junctional (at the site of cell-cell contact) or diffuse (inside the cytoplasm). CM expression was exclusively junctional in homotypic pairs but predominantly diffuse in heterotypic pairs. Noncardiomyocyte homotypic pairs exhibited diffuse expression 1.7-8.7 times more often than junctional expression, which was increased 2.6-4.4 times in heterotypic pairs. Junctional connexin43 and N-cadherin expression, respectively, were found in 38.6 +/- 7.3 and 39.6 +/- 6.2% of CM-MSC pairs, 21.9 +/- 5.0 and 13.6 +/- 1.9% of CM-SKM pairs, and in only 3.8-9.6% of CM-CF pairs. Measured frequencies of protein expression and distribution were stable for at least 4 days. Described studies in micropatterned cell pairs shed new light on cellular interactions relevant for cardiac function and cell therapies.
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Affiliation(s)
- Dawn M Pedrotty
- Dept. of Biomedical Engineering, Duke Univ., Durham, NC 27708, USA
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11
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Abstract
PURPOSE OF REVIEW The purpose was to summarize the findings of the proangiogenic clinical trials using protein and gene therapy, with analysis of the problems and an interpretation of the results. RECENT FINDINGS Recent findings include several new large clinical trials, using both gene and protein therapies. There has been development of new basic science concepts, especially with regard to endothelial activation and stabilization of newly formed microvessels. This review provides a critical analysis of the most recent clinical trials, both in efforts to understand the pitfalls of earlier clinical trials, and also to focus on requirements for future studies. SUMMARY This article reviews many of the clinical trials utilizing proangiogenic therapy, assesses the pitfalls seen within the current trials, and discusses the conclusions drawn and the future of angiogenesis therapy.
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Affiliation(s)
- Dawn M Pedrotty
- Department of Biomedical Engineering, and 2Department of Anesthesiology, Duke University, Durham, North Carolina 27708, USA
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Boyle TJ, Gallegos JJ, Pedrotty DM, Mechenbier ER, Scott BL. HETERO-ALKOXIDE GROUP (IV) AND (V) NEO-PENTOXIDE COMPOUNDS. SYNTHESES, CHARACTERIZATIONS, AND X-RAY STRUCTURES OF [Zr(μ-OCHMe2)(OCH2CMe3)3(HOCH2CMe3)]2 AND [Ta(μ-OCH2Me)(OCH2CMe3)4]2. J COORD CHEM 2006. [DOI: 10.1080/00958979908024550] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Timothy J. Boyle
- a Sandia National Laboratories, Advanced Materials Laboratory , 1001 University Boulevard SE , Albuquerque , NM , 87106 , USA
| | - Jesus J. Gallegos
- a Sandia National Laboratories, Advanced Materials Laboratory , 1001 University Boulevard SE , Albuquerque , NM , 87106 , USA
| | - Dawn M. Pedrotty
- a Sandia National Laboratories, Advanced Materials Laboratory , 1001 University Boulevard SE , Albuquerque , NM , 87106 , USA
| | - Eric R. Mechenbier
- a Sandia National Laboratories, Advanced Materials Laboratory , 1001 University Boulevard SE , Albuquerque , NM , 87106 , USA
| | - Brian L. Scott
- b Los Alamos National Laboratories, CST-18, Chemical Science and Technology Division -X-ray Diffraction Laboratory , Los Alamos , NM , 87545 , USA
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Pedrotty DM, Bursac N. Cardiomyoplasty: the prospect of human stem cells. ACTA ACUST UNITED AC 2005; 24:125-7. [PMID: 15971852 DOI: 10.1109/memb.2005.1436471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Dawn M Pedrotty
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
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Pedrotty DM, Koh J, Davis BH, Taylor DA, Wolf P, Niklason LE. Engineering skeletal myoblasts: roles of three-dimensional culture and electrical stimulation. Am J Physiol Heart Circ Physiol 2004; 288:H1620-6. [PMID: 15550526 DOI: 10.1152/ajpheart.00610.2003] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Immature skeletal muscle cells, or myoblasts, have been used in cellular cardiomyoplasty in attempts to regenerate cardiac muscle tissue by injection of cells into damaged myocardium. In some studies, muscle tissue within myoblast implant sites may be morphologically similar to cardiac muscle. We hypothesized that identifiable aspects of the cardiac milieu may contribute to growth and development of implanted myoblasts in vivo. To test this hypothesis, we designed a novel in vitro system to mimic some aspects of the electrical and biochemical environment of native myocardium. This system enabled us to separate the three-dimensional (3-D) electrical and biochemical signals that may be involved in myoblast proliferation and plasticity. Myoblasts were grown on 3-D polyglycolic acid mesh scaffolds under control conditions, in the presence of cardiac-like electrical current fluxes, or in the presence of culture medium that had been conditioned by mature cardiomyocytes. Cardiac-like electrical current fluxes caused increased myoblast number in 3-D culture, as determined by DNA assay. The increase in cell number was due to increased cellular proliferation and not differences in apoptosis, as determined by proliferating cell nuclear antigen and TdT-mediated dUTP nick-end labeling. Cardiomyocyte-conditioned medium also significantly increased myoblast proliferation. Expression of transcription factors governing differentiation along skeletal or cardiac lineages was evaluated by immunoblotting. Although these assays are qualitative, no changes in differentiation state along skeletal or cardiac lineages were observed in response to electrical current fluxes. Furthermore, from these experiments, conditioned medium did not appear to alter the differentiation state of skeletal myoblasts. Hence, cardiac milieu appears to stimulate proliferation but does not affect differentiation of skeletal myoblasts.
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Affiliation(s)
- Dawn M Pedrotty
- Dept of Biomedical Engineering, Duke University, Rm. 136 Hudson Hall, Durham, NC 27708, USA
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15
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Zechmann CA, Boyle TJ, Pedrotty DM, Alam TM, Lang DP, Scott BL. 203,205Tl NMR studies of crystallographically characterized thallium alkoxides. X-ray Structures of [TI(OCH2CMe3)]4 and [TI(OAr)]infinity, where OAr = OC6H3(Me)2-2,6 and OC6H3(CHMe2)2-2,6. Inorg Chem 2001; 40:2177-84. [PMID: 11304164 DOI: 10.1021/ic0006192] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[Tl(OCH2Me)]4 (1) was reacted with excess HOR to prepare a series of [Tl(OR)]n, where OR = OCHMe2 (2, n = 4), OCMe3 (3, n = 4), OCH2CMe3 (4, n = 4), OC6H3(Me)2-2,6 (5, n = infinity), and OC6H3(CHMe2)2-2,6 (6, n = infinity). Single-crystal X-ray diffraction experiments revealed that in the solid state the alkoxide-ligated compound 4 adopts a cubane structure, whereas the aryloxide derivatives, 5 and 6, formed polymeric chains. Compounds 1-6 were also characterized by 203,205Tl solution and 205Tl solid-state NMR spectroscopy. In solution it was determined that 1-4 retained the [Tl-O]4 cube structure, whereas the polymeric species 5 and 6 appeared to be fluxional. Variations in the solution and solid-state structures for the [Tl(OR)]4 cubes and polymeric [Tl(OAr)]infinity are influenced by the steric hindrance of the ligand. The acidity of the parent alcohol influences the degree of covalency at the Tl metal center, which is reflected in the 203,205Tl chemical shifts for 1-6.
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Affiliation(s)
- C A Zechmann
- Los Alamos National Laboratories, CST-18, Chemical Science and Technology Division, X-ray Diffraction Laboratory, Los Alamos, New Mexico 87545, USA
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16
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Boyle TJ, Pedrotty DM, Alam TM, Vick SC, Rodriguez MA. Structural diversity in solvated lithium aryloxides. Syntheses, characterization, and structures of [Li(OAr)(THF)x]n and [Li(OAr)(py)x]2 complexes where OAr = OC6H5, OC6H4(2-Me), OC6H3(2,6-(Me))2, OC6H4(2-Pr(i)), OC6H3(2,6-Pr(i)))2, OC6h4(2-Bu(t)), OC6H3(2,6-Bu(t)))2. Inorg Chem 2000; 39:5133-46. [PMID: 11233212 DOI: 10.1021/ic000432a] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of sterically varied aryl alcohols H-OAr [OAr = OC6H5 (OPh), OC6H4(2-Me) (oMP), OC6H3(2,6-(Me))2 (DMP), OC6H4(2-Pr(i)) (oPP), OC6H3(2,6-(Pr(i)))2 (DIP), OC6H4(2-Bu(t)) (oBP), OC6H3(2,6-(Bu(t)))2 (DBP); Me = CH3, Pr(i) = CHMe2, and Bu(t) = CMe3] were reacted with LiN(SiMe3)2 in a Lewis basic solvent [tetrahydrofuran (THF) or pyridine (py)] to generate the appropriate "Li(OAr)(solv)x". In the presence of THF, the OPh derivative was previously identified as the hexagonal prismatic complex [Li(OPh)(THF)]6; however, the structure isolated from the above route proved to be the tetranuclear species [Li(OPh)(THF)]4 (1). The other "Li(OAr)(THF)x" products isolated were characterized by single-crystal X-ray diffraction as [Li(OAr)(THF)]4 [OAr = oMP (2), DMP (3), oPP (4)], [Li(DIP)(THF)]3 (5), [Li(oBP)(THF)2]2, (6), and [Li(DBP)(THF)]2, (7). The tetranuclear species (1-4) consist of symmetric cubes of alternating tetrahedral Li and pyramidal O atoms, with terminal THF solvent molecules bound to each metal center. The trinuclear species 5 consists of a six-membered ring of alternating trigonal planar Li and bridging O atoms, with one THF solvent molecule bound to each metal center. Compound 6 possesses two Li atoms that adopt tetrahedral geometries involving two bridging oBP and two terminal THF ligands. The structure of 7 was identical to the previously reported [Li(DBP)(THF)]2 species, but different unit cell parameters were observed. Compound 7 varies from 6 in that only one solvent molecule is bound to each Li metal center of 7 because of the steric bulk of the DBP ligand. In contrast to the structurally diverse THF adducts, when py was used as the solvent, the appropriate "Li(OAr)(py)x" complexes were isolated as [Li(OAr)(py)2]2 (OAr = OPh (8), oMP (9), DMP (10), oPP (11), DIP (12), oBP (13)) and [Li(DBP)(py)]2 (14). Compounds 8-13 adopt a dinuclear, edge-shared tetrahedral complex. For 14, because of the steric crowding of the DBP ligand, only one py is coordinated, yielding a dinuclear fused trigonal planar arrangement. Two additional structure types were also characterized for the DIP ligand: [Li(DIP)(H-DIP)(py)]2 (12b) and [Li2(DIP)2(py)3] (12c). Multinuclear (6,7Li and 13C) solid-state MAS NMR spectroscopic studies indicate that the bulk powder possesses several Li environments for "transitional ligands" of the THF complexes; however, the py adducts possess only one Li environment, which is consistent with the solid-state structures. Solution NMR studies indicate that "transitional" compounds of the THF precursors display multiple species in solution whereas the py adducts display only one lithium environment.
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Affiliation(s)
- T J Boyle
- Sandia National Laboratories, Advanced Materials Laboratory, Albuquerque, New Mexico 87106, USA
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