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Evans CF, Iacono AT, Sanchez PG, Goloubeva O, Kim J, Timofte I, Cheema FH, Pham SM, Griffith BP, Rajagopal K. Venous Thromboembolic Complications of Lung Transplantation: A Contemporary Single-Institution Review. Ann Thorac Surg 2015; 100:2033-9; discussion 2039-40. [DOI: 10.1016/j.athoracsur.2015.05.095] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Revised: 05/10/2015] [Accepted: 05/15/2015] [Indexed: 10/23/2022]
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Pham SM. Discussion. J Thorac Cardiovasc Surg 2015; 151:496. [PMID: 26481283 DOI: 10.1016/j.jtcvs.2015.08.118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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78
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Mondal NK, Sorensen EN, Pham SM, Koenig SC, Griffith BP, Slaughter MS, Wu ZJ. Systemic Inflammatory Response Syndrome in End-Stage Heart Failure Patients Following Continuous-Flow Left Ventricular Assist Device Implantation: Differences in Plasma Redox Status and Leukocyte Activation. Artif Organs 2015; 40:434-43. [PMID: 26416627 DOI: 10.1111/aor.12580] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The role of oxidative stress and leukocyte activation has not been elucidated in developing systemic inflammatory response syndrome (SIRS) in heart failure (HF) patients after continuous-flow left ventricular assist device (CF-LVAD) implantation. The objective of this study was to investigate the change of plasma redox status and leukocyte activation in CF-LVAD implanted HF patients with or without SIRS. We recruited 31 CF-LVAD implanted HF patients (16 SIRS and 15 non-SIRS) and 11 healthy volunteers as the control. Pre- and postimplant blood samples were collected from the HF patients. Plasma levels of oxidized low-density lipoprotein (oxLDL), malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD) in erythrocyte, myeloperoxidase (MPO), and polymorphonuclear elastase (PMN-elastase) were measured. The HF patients had a preexisting condition of oxidative stress than healthy controls as evident from the higher oxLDL and MDA levels as well as depleted SOD and TAC. Leukocyte activation in terms of higher plasma MPO and PMN-elastase was also prominent in HF patients than controls. Persistent oxidative stress and reduced antioxidant status were found to be more belligerent in HF patients with SIRS after the implantation of CF-LVAD when compared with non-SIRS patients. Similar to oxidative stress, the activation of blood leukocyte was significantly highlighted in SIRS patients after implantation compared with non-SIRS. We identified that the plasma redox status and leukocyte activation became more prominent in CF-LVAD implanted HF patients who developed SIRS. Our findings suggest that plasma biomarkers of oxidative stress and leukocyte activation may be associated with the development of SIRS after CF-LVAD implant surgery.
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79
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Kon ZN, Dahi S, Evans CF, Byrnes KA, Bittle GJ, Wehman B, Rector RP, McCormick BM, Herr DL, Sanchez PG, Pham SM, Griffith BP. Long-Term Venovenous Extracorporeal Membrane Oxygenation Support for Acute Respiratory Distress Syndrome. Ann Thorac Surg 2015; 100:2059-63. [PMID: 26296269 DOI: 10.1016/j.athoracsur.2015.05.088] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 05/13/2015] [Accepted: 05/18/2015] [Indexed: 11/28/2022]
Abstract
BACKGROUND Given substantial advances in venovenous extracorporeal membrane oxygenation (ECMO) technology, long-term support is increasingly feasible. Although the benefits of short-term ECMO as a bridge to recovery in acute respiratory distress syndrome (ARDS) are well described, the utility and outcomes of long-term support remain unclear. METHODS Patients requiring ECMO for ARDS between January 2009 and November 2012 were retrospectively reviewed and analyzed separately for those requiring ECMO support for less than 3 weeks or for 3 weeks or longer. Demographic factors, ECMO variables, and outcomes were assessed. RESULTS Fifty-five patients with ARDS received ECMO during the study period, with 11 patients requiring long-term ECMO support and a median duration of 36 (interquartile range: 24 to 68) days. Recovery was the initial goal in all patients. Pre-ECMO mechanical ventilatory support, indices of disease severity, and the ECMO cannulation strategy were similar between the two groups. Eight (73%) patients receiving long-term support were bridged to recovery, and 1 patient was bridged to transplantation after a refractory course. Eight (73%) patients receiving long-term support and 25 (57%) patients receiving short-term support survived to 30 days and hospital discharge. CONCLUSIONS Previously, long-term ECMO support was thought to be associated with unfavorable outcomes. This study, however, may provide support for the efficacy of ECMO support even for 3 weeks or more as a bridge to recovery or transplantation.
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Kon ZN, Dahi S, Evans CF, Byrnes KA, Bittle GJ, Wehman B, Rector RP, McCormick BM, Herr DL, Sanchez PG, Pham SM, Griffith BP. Class III Obesity is Not a Contraindication to Venovenous Extracorporeal Membrane Oxygenation Support. Ann Thorac Surg 2015; 100:1855-60. [PMID: 26296270 DOI: 10.1016/j.athoracsur.2015.05.072] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 05/13/2015] [Accepted: 05/15/2015] [Indexed: 11/26/2022]
Abstract
BACKGROUND The use of venovenous extracorporeal membrane oxygenation (ECMO) has increased as a bridge to recovery for acute respiratory distress syndrome (ARDS) refractory to conventional support. Morbid obesity can pose a significant challenge to obtaining indexed flows, and outcomes in this population are not well described. METHODS Patients requiring ECMO for ARDS between January 2009 and November 2012 were retrospectively reviewed. Demographics, ECMO variables, and outcomes were assessed. Morbid obesity and super obesity were defined as a body mass index (BMI) greater than 40 kg/m(2) and greater than 50 kg/m(2), respectively. RESULTS Fifty-five patients with ARDS were placed on ECMO during the study period. Twelve were morbidly obese with a BMI of 49.0 kg/m(2) (interquartile range [IQR]: 45.4-57.3 kg/m(2)). Pre-ECMO mechanical ventilatory support and indices of disease severity were similar between the 2 groups, as were cannulation strategy and duration of ECMO support. Nine (75%) morbidly obese patients and 27 (63%) non-morbidly obese patients were successfully weaned from ECMO support, and patient survival to time of discharge was 67% and 58%, respectively. In the subset of super obese patients (n = 6; BMI, 57.3 kg/m(2) [IQR: 51.3-66.5 kg/m(2)]), recovery and midterm survival was 100%. CONCLUSIONS In this review, class III obesity was not associated with poorer outcomes, and based on these data, ECMO support should not be withheld from this patient population.
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Sanchez PG, Rajagopal K, Pham SM, Griffith BP. Defining quality during ex vivo lung perfusion: The University of Maryland experience. J Thorac Cardiovasc Surg 2015; 150:1376-7. [PMID: 26164650 DOI: 10.1016/j.jtcvs.2015.06.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 05/20/2015] [Accepted: 06/04/2015] [Indexed: 11/25/2022]
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82
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Mondal NK, Sorensen EN, Feller ED, Pham SM, Griffith BP, Wu ZJ. Systemic Inflammatory Response Syndrome After Contentious-Flow Left Ventricular Assist Device Implantation and Change in Platelet Mitochondrial Membrane Potential. J Card Fail 2015; 21:564-71. [PMID: 25921521 DOI: 10.1016/j.cardfail.2015.04.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 12/10/2014] [Accepted: 04/10/2015] [Indexed: 01/20/2023]
Abstract
BACKGROUND The objective of this study was to investigate the change of platelet function and platelet mitochondrial membrane potential in contentious-flow left ventricular assist device (CF-LVAD)-implanted heart failure (HF) patients with or without systemic inflammatory response syndrome (SIRS). METHODS AND RESULTS We recruited 31 CF-LVAD patients (16 SIRS and 15 non-SIRS) and 11 healthy volunteers as control. Pre- and post-implantation blood samples were collected. We used PFA-100 to test platelet functionality. Mitochondrial potential-sensitive dye was used to detect platelet dysfunction (mitochondrial membrane potential; ΔΨm) via flow cytometry. The percentage of depolarized-ΔΨm platelets was found to be a preexisting condition in all HF patients before CF-LVAD implantation compared with control subjects (10.3 ± 6.3% vs 2.8 ± 2.2%; P < .001). As evident from the PFA-100 test, the HF patients who developed SIRS after CF-LVAD implantation had significantly more qualitative platelet defects and thrombocytopathies compared with baseline. After implantation, the depolarized platelets in the SIRS patients increased by 2-fold compared with baseline (18.2 ± 8.4% vs 9.0 ± 6.6%; P < .01); whereas no change was noticed in the non-SIRS patients (10.9 ± 6.2% vs 11.7 ± 5.8%; P = .75). CONCLUSIONS We identified that platelet function and mitochondrial damage were enhanced in CF-LVAD patients with SIRS. Our findings suggest that depolarization of mitochondrial membrane potential is associated with SIRS after CF-LVAD implantation surgery.
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Mondal NK, Sorensen EN, Hiivala NJ, Feller ED, Pham SM, Griffith BP, Wu ZJ. Intraplatelet reactive oxygen species, mitochondrial damage and platelet apoptosis augment non-surgical bleeding in heart failure patients supported by continuous-flow left ventricular assist device. Platelets 2014; 26:536-44. [PMID: 25167344 DOI: 10.3109/09537104.2014.948840] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Non-surgical bleeding (NSB) is the most common clinical complication among heart failure (HF) patients supported by continuous-flow left ventricular assist devices (CF-LVADs). Understanding the role of platelet functionality contributing to NSB after CF-LVAD implantation is crucial for prevention and management of this adverse event. The aim of this study was to examine the role of intraplatelet reactive oxygen species (ROS) and platelet damage on the incidence of bleeding events after CF-LVAD implantation in HF patients. We recruited 25 HF patients implanted with CF-LVADs and 11 healthy volunteers as the control. Intraplatelet ROS generation, platelet mitochondrial damage and platelet apoptosis were quantified by flow cytometry. Among 25 patients, 8 patients developed non-surgical bleeding within one month after CF-LVAD implantation. Intraplatelet ROS, depolarized and apoptotic platelet were found to be pre-existing conditions in all baseline samples of the 25 HF patients when compared to the healthy volunteers. There was no significant difference in the levels of ROS between the non-bleeder and the bleeder groups prior to CF-LVAD implantation, although we noticed 2-fold and 1.5-fold rise in depolarized and apoptotic platelets, respectively, in the bleeder group compared to those in the non-bleeder group. Post implant levels of intraplatelet ROS, depolarized and apoptotic platelets increased and remained elevated in the bleeder group, whereas periodic decreases were noticed in the non-bleeder group, suggesting the potential role of platelet damage on bleeding incidence. ROS generation after CF-LVAD implantation positively associated with platelet apoptosis (ρ = 0.4263, p = 0.0023) and depolarized platelets (ρ = 0.4774, p = 0.0002), especially the latter. In conclusion, elevated intraplatelet ROS and platelet damage may be linked to the NSB among HF patients supported by CF-LVAD. These results provide mechanistic insights into the bleeding complication in patients with CF-LVAD support.
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84
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Rodriguez-Menocal L, Faridi MH, Martinez L, Shehadeh LA, Duque JC, Wei Y, Mesa A, Pena A, Gupta V, Pham SM, Vazquez-Padron RI. Macrophage-derived IL-18 and increased fibrinogen deposition are age-related inflammatory signatures of vascular remodeling. Am J Physiol Heart Circ Physiol 2014; 306:H641-53. [PMID: 24414074 DOI: 10.1152/ajpheart.00641.2013] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Aging has been associated with pathological vascular remodeling and increased neointimal hyperplasia. The understanding of how aging exacerbates this process is fundamental to prevent cardiovascular complications in the elderly. This study proposes a mechanism by which aging sustains leukocyte adhesion, vascular inflammation, and increased neointimal thickness after injury. The effect of aging on vascular remodeling was assessed in the rat balloon injury model using microarray analysis, immunohistochemistry, and LINCOplex assays. The injured arteries in aging rats developed thicker neointimas than those in younger animals, and this significantly correlated with a higher number of tissue macrophages and increased vascular IL-18. Indeed, IL-18 was 23-fold more abundant in the injured vasculature of aged animals compared with young rats, while circulating levels were similar in both groups of animals. The depletion of macrophages in aged rats with clodronate liposomes ameliorated vascular accumulation of IL-18 and significantly decreased neointimal formation. IL-18 was found to inhibit apoptosis of vascular smooth muscle cells (VSMC) and macrophages, thus favoring both the formation and inflammation of the neointima. In addition, injured arteries of aged rats accumulated 18-fold more fibrinogen-γ than those of young animals. Incubation of rat peritoneal macrophages with immobilized IL-18 increased leukocyte adhesion to fibrinogen and suggested a proinflammatory positive feedback loop among macrophages, VSMC, and the deposition of fibrinogen during neointimal hyperplasia. In conclusion, our data reveal that concentration changes in vascular cytokine and fibrinogen following injury in aging rats contribute to local inflammation and postinjury neointima formation.
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85
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Montero RB, Vazquez-Padron RI, Pham SM, D’Ippolito G, Andreopoulos FM. Electrospun Gelatin Constructs with Tunable Fiber Orientation Promote Directed Angiogenesis. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/ojrm.2014.31001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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86
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Lipshultz SE, Chandar JJ, Rusconi PG, Fornoni A, Abitbol CL, Burke GW, Zilleruelo GE, Pham SM, Perez EE, Karnik R, Hunter JA, Dauphin DD, Wilkinson JD. Issues in solid-organ transplantation in children: translational research from bench to bedside. Clinics (Sao Paulo) 2014; 69 Suppl 1:55-72. [PMID: 24860861 PMCID: PMC3884162 DOI: 10.6061/clinics/2014(sup01)11] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In this review, we identify important challenges facing physicians responsible for renal and cardiac transplantation in children based on a review of the contemporary medical literature. Regarding pediatric renal transplantation, we discuss the challenge of antibody-mediated rejection, focusing on both acute and chronic antibody-mediated rejection. We review new diagnostic approaches to antibody-mediated rejection, such as panel-reactive antibodies, donor-specific cross-matching, antibody assays, risk assessment and diagnosis of antibody-mediated rejection, the pathology of antibody-mediated rejection, the issue of ABO incompatibility in renal transplantation, new therapies for antibody-mediated rejection, inhibiting of residual antibodies, the suppression or depletion of B-cells, genetic approaches to treating acute antibody-mediated rejection, and identifying future translational research directions in kidney transplantation in children. Regarding pediatric cardiac transplantation, we discuss the mechanisms of cardiac transplant rejection, including the role of endomyocardial biopsy in detecting graft rejection and the role of biomarkers in detecting cardiac graft rejection, including biomarkers of inflammation, cardiomyocyte injury, or stress. We review cardiac allograft vasculopathy. We also address the role of genetic analyses, including genome-wide association studies, gene expression profiling using entities such as AlloMap®, and adenosine triphosphate release as a measure of immune function using the Cylex® ImmuKnow™ cell function assay. Finally, we identify future translational research directions in heart transplantation in children.
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Macedo FIB, Gologorsky E, Costa ACBA, Pham SM, Salerno TA. Beating heart surgery with pulmonary perfusion and ventilation during cardiopulmonary bypass: target organs' perfusion without plegia. Semin Thorac Cardiovasc Surg 2013; 24:308-10. [PMID: 23465681 DOI: 10.1053/j.semtcvs.2012.08.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/13/2012] [Indexed: 11/11/2022]
Abstract
Myocardial and pulmonary ischemia during cardiopulmonary bypass (CPB) is associated with cardiac and pulmonary dysfunction that may result in poor outcomes after cardiac surgery. Beating heart surgery and continuous pulmonary perfusion and ventilation represent emerging strategies targeting the cardiopulmonary bypass-induced ischemia and ischemia-reperfusion injury in susceptible organs--heart and lungs.
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88
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Macedo FIB, Panos AL, Andreopoulos FM, Salerno TA, Pham SM. Lung perfusion and ventilation during implantation of left ventricular assist device as a strategy to avoid postoperative pulmonary complications and right ventricular failure. Interact Cardiovasc Thorac Surg 2013; 17:764-6. [PMID: 23933964 DOI: 10.1093/icvts/ivt349] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Right ventricular failure is a major contributor to increased morbidity and mortality in patients undergoing left ventricular assist device implantation. Cardiopulmonary bypass is associated with increased pulmonary ischaemia and pulmonary vascular resistance. Continuous pulmonary perfusion and ventilation represents an emerging strategy for pulmonary protection during cardiac surgery. We hypothesize that this technique may have a pivotal role in reducing postoperative right ventricular dysfunction in high-risk patients undergoing LVAD placement.
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89
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Brodt J, Gologorsky D, Walter S, Pham SM, Gologorsky E. Orbital Compartment Syndrome Following Extracorporeal Support. J Card Surg 2013; 28:522-4. [DOI: 10.1111/jocs.12196] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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90
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Song L, Duque JC, Pena A, Shehadeh L, Webster KA, Pham SM, Vazquez-Padron RI. Abstract 364: Loss Of Systemic C-kit Function Determines Atherosclerosis Burden In Hyperlipidemic Mice. Arterioscler Thromb Vasc Biol 2013. [DOI: 10.1161/atvb.33.suppl_1.a364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Introduction
C-kit is one of the most important tyrosine kinase receptors dynamically regulated in healthy and diseased blood vessels. However, whether c-Kit signaling is beneficial or detrimental to the vasculature remains elusive. This study assesses the impact of the loss of c-Kit in somatic and circulatory cells on atherosclerosis.
Methods and Results
c-Kit expression was abundant in human aortas as determined by RT-PCR, Western blot and immunofluorescence (IF) confocal microscopy. The vascular expression of this receptor varied among patients and tended to decrease in atherosclerotic arteries. Interestingly, in the murine aorta from a c-Kit reporter mouse, GFP was only found in a sub fraction of quiescent VSMC that reside just below the endothelium. c-Kit deficiency favored VSMC proliferation when aortic explants from c-Kit mutant (W/Wv) and wild type (WT) mice were simultaneously placed in a tissue culture system (cells per well: 1337 ± 167 vs. 696 ± 108, p= 0.0123). To measure the contribution of c-Kit signaling to atherosclerosis disease in ApoE KO mice, we fed ApoE KO mice carrying the c-Kit mutant alleles W and Wv with a high-cholesterol diet for 16 weeks. The atherosclerosis plaque burden in these mice was 2.5 greater than in control ApoE KO kit
+/+
mice (affected proportion of the aorta: 0.25 ± 0.03 vs.0.104 ± 0.01, p= 0.0002). Finally, we rescued lethally irradiated ApoE KO W/Wv and control ApoE KO kit
+/+
mice with ApoE KO kit
+/+
bone marrow (BM) cells to determine how the lack of c-Kit activity in BM-derived cells modifies atherosclerosis. While BM transplantation ameliorated most of the hematopoietic defects in the ApoE W/Wv recipients, it had little or no effect on preventing atherosclerotic disease development (affected proportion of the aorta: 0.09 ± 0.01 vs.0.05 ± 0.007, p= 0.03).
Conclusion
Our results demonstrate for the first time that somatic c-Kit-positive cells may confer protection against atherosclerosis in hyperlipidemic mice.
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Macedo FIB, Salerno TA, Pham SM. Replacement of infected aortic prosthetic graft with aortic homograft after heart transplantation: 13-year follow-up. J Card Surg 2013; 28:312-4. [PMID: 23534689 DOI: 10.1111/jocs.12097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Acute ascending aortic dissection (AAAD) is a rare complication after orthotopic heart transplantation. We report a patient with AAAD after heart transplantation in whom repair was complicated by infection of the ascending aortic prosthetic graft. This was successfully managed by re-do replacement with two cryopreserved aortic homografts. Despite extensive calcification in the wall, the homografts show no aneurysm or dilation after 10 years.
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92
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Sacher VY, Andreopoulos F, Pham SM. Nonoperative management of aortic valve thrombus in a patient with left ventricular assist device. Artif Organs 2013; 37:742-3. [PMID: 23461788 DOI: 10.1111/aor.12063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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93
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Gologorsky E, Gologorsky A, Pham SM. Monitoring of Aortic Valve Opening and Systolic Aortic Insufficiency in Optimization of Continuous-Flow Left Ventricular Assist Device Settings. J Cardiothorac Vasc Anesth 2012; 26:1063-6. [DOI: 10.1053/j.jvca.2012.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Indexed: 11/11/2022]
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94
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Sacher VY, Bejarano PA, Pham SM. Tacrolimus induced hepatotoxicity in a patient with bilateral lung transplant. Transpl Int 2012; 25:e111-2. [PMID: 22909288 DOI: 10.1111/j.1432-2277.2012.01546.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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95
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Dawson J, Rodriguez Y, Pham SM, Ferreira A. Traumatic transection of the left anterior descending artery caused by a projectile. J Cardiol Cases 2012; 5:e140-e142. [DOI: 10.1016/j.jccase.2012.02.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Revised: 01/27/2012] [Accepted: 02/08/2012] [Indexed: 11/16/2022] Open
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Montero RB, Vial X, Nguyen DT, Farhand S, Reardon M, Pham SM, Tsechpenakis G, Andreopoulos FM. bFGF-containing electrospun gelatin scaffolds with controlled nano-architectural features for directed angiogenesis. Acta Biomater 2012; 8:1778-91. [PMID: 22200610 DOI: 10.1016/j.actbio.2011.12.008] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 11/09/2011] [Accepted: 12/06/2011] [Indexed: 11/26/2022]
Abstract
Current therapeutic angiogenesis strategies are focused on the development of biologically responsive scaffolds that can deliver multiple angiogenic cytokines and/or cells in ischemic regions. Herein, we report on a novel electrospinning approach to fabricate cytokine-containing nanofibrous scaffolds with tunable architecture to promote angiogenesis. Fiber diameter and uniformity were controlled by varying the concentration of the polymeric (i.e. gelatin) solution, the feed rate, needle to collector distance, and electric field potential between the collector plate and injection needle. Scaffold fiber orientation (random vs. aligned) was achieved by alternating the polarity of two parallel electrodes placed on the collector plate thus dictating fiber deposition patterns. Basic fibroblast growth factor (bFGF) was physically immobilized within the gelatin scaffolds at variable concentrations and human umbilical vein endothelial cells (HUVEC) were seeded on the top of the scaffolds. Cell proliferation and migration was assessed as a function of growth factor loading and scaffold architecture. HUVECs successfully adhered onto gelatin B scaffolds and cell proliferation was directly proportional to the loading concentrations of the growth factor (0-100 bFGF ng/mL). Fiber orientation had a pronounced effect on cell morphology and orientation. Cells were spread along the fibers of the electrospun scaffolds with the aligned orientation and developed a spindle-like morphology parallel to the scaffold's fibers. In contrast, cells seeded onto the scaffolds with random fiber orientation, did not demonstrate any directionality and appeared to have a rounder shape. Capillary formation (i.e. sprouts length and number of sprouts per bead), assessed in a 3-D in vitro angiogenesis assay, was a function of bFGF loading concentration (0 ng, 50 ng and 100 ng per scaffold) for both types of electrospun scaffolds (i.e. with aligned or random fiber orientation).
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Gelape CL, Pham SM. Advances in mechanical circulatory support in the treatment of heart failure. Arq Bras Cardiol 2012; 98:e36-43. [PMID: 22378342 DOI: 10.1590/s0066-782x2012000200018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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98
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Rahnemai-Azar A, D'Ippolito G, Gomez LA, Reiner T, Vazquez-Padron RI, Perez-Stable C, Roos BA, Pham SM, Schiller PC. Human marrow-isolated adult multilineage-inducible (MIAMI) cells protect against peripheral vascular ischemia in a mouse model. Cytotherapy 2011; 13:179-92. [DOI: 10.3109/14653249.2010.515579] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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99
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Layman H, Li X, Nagar E, Vial X, Pham SM, Andreopoulos FM. Enhanced angiogenic efficacy through controlled and sustained delivery of FGF-2 and G-CSF from fibrin hydrogels containing ionic-albumin microspheres. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2010; 23:185-206. [PMID: 21192837 DOI: 10.1163/092050610x546417] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Neo-vessel formation in ischemic tissues relies on numerous growth factors and cell fractions for the formation of mature, stable, functional vasculature. However, the efforts to regenerate tissues typically rely on the administration of a single growth factor or cells alone. Conversely, polymeric matrices have been investigated extensively to deliver multiple growth factors at pre-determined rates to form stable blood vessels in ischemic tissues. We report on a novel sequential delivery system of a fibrin hydrogel containing ionic-albumin microspheres that allows for the controlled release of two growth factors. The use of this system was investigated in the context of therapeutic angiogenesis. Material properties were determined based on degree of swelling measurements and degradation characteristics. Release kinetics of model angiogenic polypeptides FGF-2 and G-CSF were determined using ELISA and the bioactivity of released protein was evaluated in human endothelial cell cultures. The release of growth factors from ionic-albumin microspheres was significantly delayed compared to the growth factor released from fibrin matrices in the absence of spheres. The scaffolds were implanted in a murine critical limb ischemia model at two concentrations, 40 ng (low) and 400 ng (high), restoring 92% of the blood flow in a normally perfused limb using a fibrin hydrogel releasing FGF-2 containing albumin-PLL microspheres releasing G-CSF (measured by LDPI at the high concentration), a 3.2-fold increase compared to untreated limbs. The extent of neo-vessel formation was delineated by immunohistochemical staining for capillary density (CD-31+) and mature vessel formation (α-SMA+). In conclusion, our study demonstrated that the release kinetics from our scaffold have distinct kinetics previously unpublished and the delivery of these factors resulted in hindlimb reperfusion, and robust capillary and mature vessel formation after 8 weeks compared to either growth factor alone or bolus administration of growth factor.
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Layman H, Rahnemai-Azar AA, Pham SM, Tsechpenakis G, Andreopoulos FM. Synergistic angiogenic effect of codelivering fibroblast growth factor 2 and granulocyte-colony stimulating factor from fibrin scaffolds and bone marrow transplantation in critical limb ischemia. Tissue Eng Part A 2010; 17:243-54. [PMID: 20712534 DOI: 10.1089/ten.tea.2010.0270] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Increasing evidence suggests that therapeutic angiogenesis strategies utilizing cytokines and stem cells are necessary to treat traumatic vascular events such as critical limb ischemia and peripheral artery disease. In this study, basic fibroblast growth factor 2 (FGF-2) and granulocyte-colony stimulating factor (G-CSF) were immobilized in fibrin matrices and codelivered in combination with unfractionated bone marrow cells. Hindlimb ischemia was induced on young (6-7 weeks) Balb/C mice, and fibrin gels containing 100 ng/mL of FGF-2 and G-CSF were implanted adjacent to the ligation points. In addition, 1×10(6) bone marrow (BM) cells were injected into five locations in the ischemic muscle immediately after ligation and artery excision. Hindlimb reperfusion was determined by Laser Doppler Perfusion Imaging and immunohistochemistry for CD31+ and smooth muscle actin-positive cells at 2, 4, and 8 weeks postsurgery to identify capillary formation and maturation. A fluorescent vessel painting technique was also utilized to determine the extent of angiogenesis and arteriogenesis in the hindlimb at 8 weeks postsurgery. The codelivery of FGF-2 and G-CSF in combination with BM cells led to enhanced therapeutic recovery in critical limb ischemia Balb/C mice after 8 weeks of treatment with 87.2% blood flow recovery and a significant increase (p<0.05) in capillary formation in comparison to growth factor delivery or BM cell administration alone.
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