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Azar F, Boulier K, Hassani C, Shahandeh N, Cruz D, Aboulhosn JA, Fishbein MC, Kwon MH, Yang EH. TIGHT SQUEEZE: A CASE OF CARDIAC EXTENSIVE LIPOMATOSIS WITH ATRIAL INFILTRATION AND SUPERIOR VENA CAVA COMPRESSION. J Am Coll Cardiol 2023. [DOI: 10.1016/s0735-1097(23)03405-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
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Simone A, Kim JS, Huchting J, Rafique A, Ozcaglayan R, Shemin RJ, Aksoy O, Kwon MH. Transcatheter Aortic Valve Replacement for Severe Aortic Valve Stenosis: Do Patients Experience Better Quality of Life Regardless of Gradient? Tex Heart Inst J 2023; 50:490387. [PMID: 36695735 PMCID: PMC9969767 DOI: 10.14503/thij-21-7659] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND Aortic valve replacement improves survival for patients with low-gradient aortic valve stenosis, but there is a paucity of data on postoperative quality of life for this population. METHODS In a single-center retrospective analysis of 304 patients with severe aortic valve stenosis who underwent transcatheter aortic valve replacement, patients were divided into 4 groups based on mean pressure gradient, left ventricular ejection fraction, and stroke volume index. Using the Kansas City Cardiomyopathy Questionnaire-12, quality of life was assessed immediately before and 1 month after transcatheter aortic valve replacement. RESULTS Most patients in the low-flow, low-gradient group were men; this group had higher relative rates of cardiovascular disease and type 2 diabetes than the paradoxical low-flow, low-gradient group; the normal-flow, low-gradient group; and the high-gradient group. All-cause mortality did not differ significantly among the groups at 1 month after surgery, and all groups experienced a significant improvement in quality-of-life scores after surgery. The mean improvement was 27 points in the low-flow, low-gradient group, 25 points in the paradoxical low-flow, low-gradient group, 30 points in the normal-flow, low-gradient group, and 30 points in the high-gradient group (all P < .001). CONCLUSION Quality of life improves significantly across all subgroups of aortic valve stenosis after trans-catheter aortic valve replacement, regardless of flow characteristics or aortic valve gradients.
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Affiliation(s)
- Anthony Simone
- Department of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
,Department of Cardiology, Kaiser Permanente Los Angeles Medical Center, Los Angeles, California
| | - Juka S. Kim
- Department of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Jeanne Huchting
- Department of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Asim Rafique
- Department of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Ruhsen Ozcaglayan
- Department of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Richard J. Shemin
- Department of Cardiac Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Olcay Aksoy
- Department of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Murray H. Kwon
- Department of Cardiac Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
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Xia Y, Kim JS, Eng IK, Nsair A, Ardehali A, Shemin RJ, Kwon MH. Outcomes of heart transplant recipients bridged with percutaneous versus durable left ventricular assist devices. Clin Transplant 2023; 37:e14904. [PMID: 36594638 DOI: 10.1111/ctr.14904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 12/23/2022] [Accepted: 12/28/2022] [Indexed: 01/04/2023]
Abstract
BACKGROUND The new United Network for Organ Sharing (UNOS) heart allocation policy prioritizes temporary percutaneous over durable left ventricular assist devices (LVAD) as bridge to transplant. We sought to examine 1-year outcomes of heart transplant recipients bridged with Impella versus durable LVADs. METHODS All primary adult orthotopic heart transplant recipients registered in UNOS between January 2016 and June 2021 were analyzed. Recipients were identified as being bridged with isolated durable or percutaneous LVAD at the time of transplant. Baseline characteristics were compared and 1-year survival was examined using the Kaplan Meier method and multivariable Cox proportional hazards regression. RESULTS During our study period, heart transplant recipients bridged with LVADs were divided between 5422(94%) durable and 324(6%) percutaneous options. Impella-bridged recipients were more likely to be status 1A under the old allocation system (98% vs. 70%, p < .01) and status 2 or higher under the new allocation system (99% vs. 24%, p < .01). Impella-bridged recipients were less likely to be obese (27% vs. 42%, p < .01), have ischemic cardiomyopathy (27% vs. 34%, p < .01), and were more likely to be on inotropic agents at the time of transplant (68% vs. 6%, p < .01). One-year post-transplant survival was not significantly different between the two groups on univariable (HR .87, 95% CI .56-1.37) or multivariable analysis (aHR .63, 95% CI .37-1.07). CONCLUSIONS Following the UNOS allocation policy change, Impella utilization has increased with no significant difference in 1-year survival compared to bridge with durable LVADs. Impella may be a reasonable alternative to durable LVADs in select patients.
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Affiliation(s)
- Yu Xia
- Division of Cardiac Surgery, Department of Surgery, University of California Los Angeles, David Geffen School of Medicine, Los Angeles, California, USA
| | - Juka S Kim
- Division of Cardiac Surgery, Department of Surgery, University of California Los Angeles, David Geffen School of Medicine, Los Angeles, California, USA
| | - Isabel K Eng
- Division of Cardiac Surgery, Department of Surgery, University of California Los Angeles, David Geffen School of Medicine, Los Angeles, California, USA
| | - Ali Nsair
- Department of Medicine, Division of Cardiology, University of California, Los Angeles, David Geffen School of Medicine, Los Angeles, California, USA
| | - Abbas Ardehali
- Division of Cardiac Surgery, Department of Surgery, University of California Los Angeles, David Geffen School of Medicine, Los Angeles, California, USA
| | - Richard J Shemin
- Division of Cardiac Surgery, Department of Surgery, University of California Los Angeles, David Geffen School of Medicine, Los Angeles, California, USA
| | - Murray H Kwon
- Division of Cardiac Surgery, Department of Surgery, University of California Los Angeles, David Geffen School of Medicine, Los Angeles, California, USA
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Kim JS, Lee B, Chu A, Kwon MH. Retained left ventricular assist device driveline in a heart transplant recipient: A case report. JTCVS Tech 2022; 15:133-135. [PMID: 36276676 PMCID: PMC9579709 DOI: 10.1016/j.xjtc.2022.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 06/22/2022] [Accepted: 07/01/2022] [Indexed: 12/04/2022] Open
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Bae DJ, Wadia SK, Kim JS, Moreno E, Ardehali R, Shemin RJ, Kwon MH. Validity of echocardiography for detection of left ventricular thrombus with surgical validation in patients awaiting durable left ventricular assist device. J Card Surg 2021; 36:2722-2728. [PMID: 34047391 DOI: 10.1111/jocs.15662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 04/24/2021] [Accepted: 04/30/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Unrecognized left ventricular thrombi (LVT) can have devastating clinical implications and precludes patients with end-stage heart failure from undergoing left ventricular assist device (LVAD) implantation without cardiopulmonary bypass assistance. We assessed the reliability of an echocardiogram to diagnose LVT in patients with end-stage heart disease who underwent LVAD implantation. METHODS A single-center retrospective study evaluated 232 consecutive adult patients requiring implantation of durable LVADs between 2005 and 2019. The validity of preoperative transthoracic echocardiogram (TTE) and intraoperative transesophageal echocardiogram (TEE) for diagnosing LVT was compared to direct inspection at the time of LVAD implantation. RESULTS There were 232 patients that underwent LVAD implantation, with 226 patients (97%) receiving a preoperative TTE. Of those 226 patients, 32 patients (14%) received ultrasound enhancing agents (UEA). Intraoperative TEE images were available in 195 patients (84%). The sensitivity of TTE without UEA was 22% and specificity was 90% for detecting LVT, compared to 50% and 86%, respectively, for TTE with UEA. For intraoperative TEE, the sensitivity and specificity were 46% and 96%, respectively. The false omission rate ranged from 4% to 8% for all modalities of echocardiography. CONCLUSION Among patients undergoing LVAD implantation, preoperative TTE and intraoperative TEE had poor sensitivity for LVT detection. Up to 8% of echocardiograms were incorrectly concluded to be negative for LVT on surgical validation. The low sensitivity and positive predictive value for diagnosing LVT suggest that echocardiography has limited reliability in this cohort of patients who are at high risk of LVT formation and its subsequent complications.
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Affiliation(s)
- David J Bae
- Division of Cardiology, University of California, Los Angeles, California, USA
| | - Subeer K Wadia
- Division of Cardiology, University of California, Los Angeles, California, USA
| | - Juka S Kim
- David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Elan Moreno
- Division of Cardiology, University of California, Los Angeles, California, USA
| | - Reza Ardehali
- Division of Cardiology, University of California, Los Angeles, California, USA
| | - Richard J Shemin
- Division of Cardiothoracic Surgery, University of California, Los Angeles, California, USA
| | - Murray H Kwon
- Division of Cardiothoracic Surgery, University of California, Los Angeles, California, USA
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Kim JS, Hernandez RA, Smink DS, Yule S, Jackson NJ, Shemin RJ, Kwon MH. Nontechnical skills training in cardiothoracic surgery: A pilot study. J Thorac Cardiovasc Surg 2021; 163:2155-2162.e4. [PMID: 33676757 DOI: 10.1016/j.jtcvs.2021.01.108] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 01/18/2021] [Accepted: 01/25/2021] [Indexed: 02/06/2023]
Abstract
OBJECTIVE The importance of nontechnical skills in surgery is widely recognized. We demonstrate the feasibility of administering and assessing the results of a formal Non-Technical Skills in Surgery (NOTSS) curriculum to cardiothoracic surgery residents. METHODS Eight cardiothoracic surgery residents participated in the NOTSS curriculum. They were assessed on their cognitive (situation awareness, decision-making) and social (communication and teamwork, leadership) skills based on simulated vignettes. The residents underwent pretraining NOTSS assessments followed by self-administered confidence ratings regarding the 4 skills. Subsequently, a formal NOTSS lecture was delivered and additional readings from the NOTSS textbook was assigned. A month later, the residents returned for post-training NOTSS assessments and self-administered confidence ratings. Changes across days (or within-day before vs after curriculum) were assessed using Wilcoxon signed rank test. RESULTS There was a significant improvement in the overall NOTSS assessment score (P = .01) as well as in the individual categories (situation awareness, P = .02; decision-making, P = .02; communication and teamwork, P = .01; leadership, P = .02). There was also an increase in resident self-perception of improvement on the post-training day (P = .01). CONCLUSIONS We have developed a simulation-based NOTSS curriculum in cardiothoracic surgery that can be formally integrated into the current residency education. This pilot study indicates the feasibility of reproducible assessments by course educators and self-assessments by participating residents in nontechnical skills competencies.
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Affiliation(s)
- Juka S Kim
- Division of Cardiac Surgery, Department of Surgery, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, Calif
| | | | - Douglas S Smink
- Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass
| | - Steven Yule
- Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass; Neil and Elise Wallace STRATUS Center for Medical Simulation, Brigham and Women's Hospital, Boston, Mass
| | - Nicholas J Jackson
- Department of Medicine Statistics Core, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, Calif
| | - Richard J Shemin
- Division of Cardiac Surgery, Department of Surgery, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, Calif
| | - Murray H Kwon
- Division of Cardiac Surgery, Department of Surgery, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, Calif.
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Zucker DJS, Smith A, Srinivasa RN, Yang EH, Kwon MH, Moriarty JM. Minimally Invasive Repair of Ascending Aortic Pseudoaneurysms: An Alternative to Open Surgical Repair in High-Risk Patients. J Vasc Interv Radiol 2020; 31:1342-1347.e1. [PMID: 32680683 DOI: 10.1016/j.jvir.2020.01.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 01/01/2020] [Accepted: 01/03/2020] [Indexed: 11/27/2022] Open
Abstract
Development of a pseudoaneurysm of the ascending aorta is an uncommon complication of aortic surgery. Several nonsurgical techniques are available for treatment of ascending aortic pseudoaneurysms (AAPs). This report outlines a single-center retrospective experience with 14 nonsurgical procedures for treatment of AAPs in 10 patients. Modified stent grafts, septal defect occlusion devices, coil embolics, and liquid embolics were deployed by transthoracic and endovascular approaches. Complete stasis of the AAP was achieved in 7 of 10 patients (70%). Mean postprocedural recoveries occurred within 3.5 days. Nonsurgical techniques for repair of AAPs offer a comparatively safe and effective alternative to open surgical repair.
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Affiliation(s)
- David J S Zucker
- Department of Radiology, Division of Vascular and Interventional Radiology, University of California Los Angeles Medical Center, Los Angeles, California
| | - Aaron Smith
- Department of Radiology, Division of Vascular and Interventional Radiology, University of California Los Angeles Medical Center, Los Angeles, California
| | - Ravi N Srinivasa
- Department of Radiology, Division of Vascular and Interventional Radiology, University of California Los Angeles Medical Center, Los Angeles, California
| | - Eric H Yang
- Department Medicine, Division of Vascular and Interventional Radiology, University of California Los Angeles Medical Center, Los Angeles, California
| | - Murray H Kwon
- Department Surgery, Division of Vascular and Interventional Radiology, University of California Los Angeles Medical Center, Los Angeles, California
| | - John M Moriarty
- Department of Radiology, Division of Vascular and Interventional Radiology, University of California Los Angeles Medical Center, Los Angeles, California.
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Rudasill SE, Iyengar A, Sanaiha Y, Khoury H, Mardock AL, Xing H, Kwon MH, Hunter C, Benharash P. Pretransplant malignancy among lung transplant recipients in the modern era. Surgery 2019; 165:1228-1233. [DOI: 10.1016/j.surg.2019.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 12/29/2018] [Accepted: 01/19/2019] [Indexed: 02/07/2023]
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Bakir M, Jackson NJ, Han SX, Bui A, Chang E, Liem DA, Ardehali A, Ardehali R, Baas AS, Press MC, Cruz D, Deng MC, DePasquale EC, Fonarow GC, Khuu T, Kwon MH, Kubak BM, Nsair A, Phung JL, Reed EF, Schaenman JM, Shemin RJ, Zhang QJ, Tseng CH, Cadeiras M. Clinical phenomapping and outcomes after heart transplantation. J Heart Lung Transplant 2018; 37:956-966. [PMID: 29802085 PMCID: PMC6064662 DOI: 10.1016/j.healun.2018.03.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 03/12/2018] [Accepted: 03/14/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Survival after heart transplantation (HTx) is limited by complications related to alloreactivity, immune suppression, and adverse effects of pharmacologic therapies. We hypothesize that time-dependent phenomapping of clinical and molecular data sets is a valuable approach to clinical assessments and guiding medical management to improve outcomes. METHODS We analyzed clinical, therapeutic, biomarker, and outcome data from 94 adult HTx patients and 1,557 clinical encounters performed between January 2010 and April 2013. Multivariate analyses were used to evaluate the association between immunosuppression therapy, biomarkers, and the combined clinical end point of death, allograft loss, retransplantation, and rejection. Data were analyzed by K-means clustering (K = 2) to identify patterns of similar combined immunosuppression management, and percentile slopes were computed to examine the changes in dosages over time. Findings were correlated with clinical parameters, human leucocyte antigen antibody titers, and peripheral blood mononuclear cell gene expression of the AlloMap (CareDx, Inc., Brisbane, CA) test genes. An intragraft, heart tissue gene coexpression network analysis was performed. RESULTS Unsupervised cluster analysis of immunosuppressive therapies identified 2 groups, 1 characterized by a steeper immunosuppression minimization, associated with a higher likelihood for the combined end point, and the other by a less pronounced change. A time-dependent phenomap suggested that patients in the group with higher event rates had increased human leukocyte antigen class I and II antibody titers, higher expression of the FLT3 AlloMap gene, and lower expression of the MARCH8 and WDR40A AlloMap genes. Intramyocardial biomarker-related coexpression network analysis of the FLT3 gene showed an immune system-related network underlying this biomarker. CONCLUSIONS Time-dependent precision phenotyping is a mechanistically insightful, data-driven approach to characterize patterns of clinical care and identify ways to improve clinical management and outcomes.
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Affiliation(s)
- Maral Bakir
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine
| | | | | | | | - Eleanor Chang
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine
| | - David A Liem
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine
| | - Abbas Ardehali
- Department of Surgery, University of California, Los Angeles, Los Angeles, California
| | - Reza Ardehali
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine
| | - Arnold S Baas
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine
| | | | - Daniel Cruz
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine
| | - Mario C Deng
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine
| | - Eugene C DePasquale
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine
| | - Gregg C Fonarow
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine
| | - Tam Khuu
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine
| | - Murray H Kwon
- Department of Surgery, University of California, Los Angeles, Los Angeles, California
| | - Bernard M Kubak
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine
| | - Ali Nsair
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine
| | - Jennifer L Phung
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine
| | | | - Joanna M Schaenman
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine
| | - Richard J Shemin
- Department of Surgery, University of California, Los Angeles, Los Angeles, California
| | | | | | - Martin Cadeiras
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine.
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Affiliation(s)
- Murray H Kwon
- Division of Cardiac Surgery, Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, Calif.
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Kim HM, Lee BR, Lee ES, Kwon MH, Huh JH, Kwon BE, Park EK, Chang SY, Kweon MN, Kim PH, Ko HJ, Chung CH. iNKT cells prevent obesity-induced hepatic steatosis in mice in a C-C chemokine receptor 7-dependent manner. Int J Obes (Lond) 2017; 42:270-279. [PMID: 28811651 PMCID: PMC5803573 DOI: 10.1038/ijo.2017.200] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 06/19/2017] [Accepted: 07/21/2017] [Indexed: 02/08/2023]
Abstract
Non-alcoholic fatty liver disease and non-alcoholic steatohepatitis are characterized by an increase in hepatic triglyceride content with infiltration of immune cells, which can cause steatohepatitis and hepatic insulin resistance. C-C chemokine receptor 7 (CCR7) is primarily expressed in immune cells, and CCR7 deficiency leads to the development of multi-organ autoimmunity, chronic renal disease and autoimmune diabetes. Here, we investigated the effect of CCR7 on hepatic steatosis in a mouse model and its underlying mechanism. Our results demonstrated that body and liver weights were higher in the CCR7−/− mice than in the wild-type (WT) mice when they were fed a high-fat diet. Further, glucose tolerance and insulin sensitivity were markedly diminished in CCR7−/− mice. The number of invariant natural killer T (iNKT) cells was reduced in the livers of the CCR7−/− mice. Moreover, liver inflammation was detected in obese CCR7−/− mice, which was ameliorated by the adoptive transfer of hepatic mononuclear cells from WT mice, but not through the transfer of hepatic mononuclear cells from CD1d−/− or interleukin-10-deficient (IL-10−/−) mice. Overall, these results suggest that CCR7+ mononuclear cells in the liver could regulate obesity-induced hepatic steatosis via induction of IL-10-expressing iNKT cells.
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Affiliation(s)
- H M Kim
- Department of Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Korea.,Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - B R Lee
- Laboratory of Microbiology and Immunology, College of Pharmacy, Kangwon National University, Chuncheon, Korea
| | - E S Lee
- Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - M H Kwon
- Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - J H Huh
- Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - B-E Kwon
- Laboratory of Microbiology and Immunology, College of Pharmacy, Kangwon National University, Chuncheon, Korea
| | - E-K Park
- Laboratory of Microbiology and Immunology, College of Pharmacy, Kangwon National University, Chuncheon, Korea
| | - S-Y Chang
- College of Pharmacy, Ajou University, Suwon, Korea
| | - M-N Kweon
- Mucosal Immunology Laboratory, Department of Convergence Medicine, University of Ulsan College of Medicine/Asan Medical Center, Seoul, Korea
| | - P-H Kim
- Department of Molecular Bioscience, School of Biomedical Science, Kangwon National University, Chuncheon, Korea
| | - H-J Ko
- Laboratory of Microbiology and Immunology, College of Pharmacy, Kangwon National University, Chuncheon, Korea
| | - C H Chung
- Department of Global Medical Science, Yonsei University Wonju College of Medicine, Wonju, Korea.,Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
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12
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Kwon MH. Postoperative atrial fibrillation: Can an ounce of prevention eliminate a pound of cure? J Thorac Cardiovasc Surg 2017; 154:1652-1653. [PMID: 28689789 DOI: 10.1016/j.jtcvs.2017.06.028] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 06/12/2017] [Indexed: 11/19/2022]
Affiliation(s)
- Murray H Kwon
- Division of Cardiac Surgery, Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, Calif.
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13
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Abstract
Tricuspid valve regurgitation (TVR) in the orthotopic heart transplant (OHT) recipient is quite common and has varied clinical sequelae. In its severest forms, it can lead to right-sided failure symptoms indistinguishable from that seen in native heart TVR disease. While certain implantation techniques are widely recognized to reduce the risk of TVR in the cardiac allograft, concomitant tricuspid annuloplasty, while having advocates, is not currently accepted as a routinely established adjunct. Decisions to surgically correct TVR in the OHT recipient must be made carefully, as certain clinical scenarios have high risk of failure. Like in the native heart, anatomic etiologies typically have the greatest chances for success compared to functional etiologies. While repair options have been utilized, there is emerging data to support replacement as the more durable option. While mechanical prostheses are impractical in the heart transplant recipient, biologic valves offer the advantage of continued access to the right ventricle for biopsies in addition to acceptable durability in the low pressure system of the right side.
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Affiliation(s)
- Murray H Kwon
- Division of Cardiac Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Richard J Shemin
- Division of Cardiac Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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14
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Kwon MH, Zhang JQ, Schaenman JM, Cadeiras M, Gjertson DW, Krystal CA, Laks H, Ardehali A, Deng MC, Shemin RJ, Reed EF. Characterization of ventricular assist device-mediated sensitization in the bridge-to-heart-transplantation patient. J Thorac Cardiovasc Surg 2015; 149:1161-6. [PMID: 25702320 DOI: 10.1016/j.jtcvs.2015.01.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [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] [Received: 10/17/2014] [Revised: 12/19/2014] [Accepted: 01/02/2015] [Indexed: 12/01/2022]
Abstract
OBJECTIVE Ventricular assist devices (VADs) are associated with increased anti-human leukocyte antigen antibody production. The purpose of this study is to characterize differences in sensitization patterns in patients receiving axial flow, implantable VADs versus pulsatile, paracorporeal biventricular assist devices (BIVADs) as bridges to transplantation. METHODS The study is a retrospective review of 68 patients who were bridged to transplantation with either a VAD or a BIVAD, as described, from January 2007 to June 2010, at a university medical center. RESULTS Five of 15 (33.3%) VAD patients became sensitized during treatment, compared with 30 of 53 (56.6%) BIVAD patients, P = .15. Multivariable analysis comparing BIVAD with VAD, while controlling for previous cardiac surgery, pregnancy, and packed red blood cell transfusion produced an odds ratio of 2.99, P = .14. Of sensitized patients, all 5 (100%) of the VAD patients had pre-existing antibodies before VAD placement, compared with 9 of 30 (30.0%) BIVAD patients, P = .006. Maximum cumulative mean fluorescence intensities for BIVAD were 46,259 ± 66,349 versus 42,540 ± 12,840 for VAD, P = .90. Time to maximum antibody expression was shorter for the VAD group (34 ± 28 days vs 5.8 ± 9 days, P = .04). CONCLUSIONS Device type was not a factor in patient sensitization after implantation. However, VAD patients required pre-existing sensitization before implantation to produce antibodies during their treatment interval, whereas more than two thirds of BIVAD patients developed de novo antibodies. These data suggest that the mechanism of sensitization between VAD and BIVAD patients may differ, and further mechanistic studies into the impact of device types on patient sensitization are warranted.
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Affiliation(s)
- Murray H Kwon
- Division of Cardiothoracic Surgery, Department of Surgery, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, Calif.
| | - Jennifer Q Zhang
- University of California, Los Angeles Immunogenetics Center, University of California, Los Angeles, Los Angeles, Calif
| | - Joanna M Schaenman
- Division of Immunology, Department of Medicine, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, Calif
| | - Martin Cadeiras
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, Calif
| | - David W Gjertson
- University of California, Los Angeles Immunogenetics Center, University of California, Los Angeles, Los Angeles, Calif
| | - Carolyn A Krystal
- David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, Calif
| | - Hillel Laks
- Division of Cardiothoracic Surgery, Department of Surgery, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, Calif
| | - Abbas Ardehali
- Division of Cardiothoracic Surgery, Department of Surgery, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, Calif
| | - Mario C Deng
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, Calif
| | - Richard J Shemin
- Division of Cardiothoracic Surgery, Department of Surgery, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, Calif
| | - Elaine F Reed
- University of California, Los Angeles Immunogenetics Center, University of California, Los Angeles, Los Angeles, Calif
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15
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Suh WM, Vorobiof G, Shemin RJ, Kwon MH, Fusari M, Tobis JM. Treating aortic stenosis and mitral regurgitation with 1 transcatheter heart valve: 2 birds with 1 stone. J Am Coll Cardiol 2013; 61:e349. [PMID: 23603233 DOI: 10.1016/j.jacc.2012.12.059] [Citation(s) in RCA: 0] [Impact Index Per Article: 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] [Received: 11/29/2012] [Accepted: 12/11/2012] [Indexed: 11/25/2022]
Affiliation(s)
- William M Suh
- Division of Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Gabriel Vorobiof
- Division of Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Richard J Shemin
- Division of Cardiothoracic Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Murray H Kwon
- Division of Cardiothoracic Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
| | | | - Jonathan M Tobis
- Division of Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, California
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16
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Yang EH, Kwon MH, Mahajan A, Child JS, Tobis JM, Manthripragada G, Silverstein CA, Shamsa K. Circumferential type A aortic dissection and intimal intussusception of the aorta causing severe aortic regurgitation and obstruction of the left main coronary artery. Echocardiography 2012; 30:E81-4. [PMID: 23228057 DOI: 10.1111/echo.12071] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Eric H Yang
- Division of Cardiology, Department of Medicine, University of California at Los Angeles Medical Center, Los Angeles, CA 90095, USA
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17
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Kwon MH, Wong SY, Ardehali A, Laks H, Zhang ZK, Deng MC, Shemin RJ. Primary graft dysfunction does not lead to increased cardiac allograft vasculopathy in surviving patients. J Thorac Cardiovasc Surg 2012; 145:869-73. [PMID: 23083793 DOI: 10.1016/j.jtcvs.2012.09.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [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] [Received: 02/22/2012] [Revised: 07/16/2012] [Accepted: 09/13/2012] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Early injury is associated with the development of cardiac allograft vasculopathy in heart transplantation. We examined whether adult heart transplant recipients surviving primary graft dysfunction were more susceptible to the development of cardiac allograft vasculopathy than their nonprimary graft dysfunction counterparts. METHODS A total of 857 patients who underwent heart transplantation between January 1994 and December 2008 at our institution were reviewed. Primary graft dysfunction was defined as the need for extracorporeal membrane oxygenation, open chest, or intra-aortic balloon pump placement within 72 hours of transplantation. Cardiac allograft vasculopathy was defined as ≥50% coronary artery stenosis in any vessel. Allograft survival was defined by patient death or need for retransplantation. RESULTS Completed follow-up was available for 32 patients in the primary graft dysfunction group and 701 patients in the nonprimary graft dysfunction group. Mean recipient ages (56 years vs 55 years, respectively; P = .50) and ischemic times (220 minutes vs 208 minutes, respectively; P = .35) were similar. Donor age was significantly higher in the primary graft dysfunction group (38 years vs 32 years, P = .02). Five-year survivals for the primary graft dysfunction and nonprimary graft dysfunction groups were 46.9% versus 78.9% (P < .001). Conditional 5-year survivals in patients surviving the first year were 78.9% and 88.3% for the primary graft dysfunction and nonprimary graft dysfunction groups, respectively (P = .18). Within a 30-day postoperative period, there were more deaths in the primary graft dysfunction group (28.1% vs 2.3%, P < .0001) and more retransplants (6.25% vs 0%, P = .002). Of the patients surviving past 30 days, only 2 (8.7%) of the primary graft dysfunction patients developed cardiac allograft vasculopathy versus 144 (21.0%) in the nonprimary graft dysfunction group (P < .001). CONCLUSIONS Primary graft dysfunction was associated with lower 30-day, 1-year, and 5-year allograft survival rates. Surviving patients, however, did not show increased tendency toward cardiac allograft vasculopathy development.
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Affiliation(s)
- Murray H Kwon
- Division of Cardiothoracic Surgery, Department of Surgery, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, USA.
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18
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Kwon MH, Zhang JQ, Abrahamyan A, Zhang ZK, Gjertson DW, Ardehali A, Kobashigawa J, Shemin RJ, Reed EF. Abstract P122: Characterization of Ventricular Assist Device Mediated Sensitization in the Bridge to Heart Transplant Patient. Circ Res 2011. [DOI: 10.1161/res.109.suppl_1.ap122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 11/16/2022]
Abstract
Purpose:
To clarify patterns of anti-HLA antibody expression (sensitization) occurring in patients bridged to transplantation (BTT) with ventricular assist devices (VADs).
Methods:
The study is a retrospective review of 68 patients undergoing BTT with either Heartmate II (HMII) axial flow LVAD or paracorporal BIVAD from January 2007 to July 2010 at UCLA Medical Center.
Results:
Five of 15 (33.3%) HMII pts became sensitized during treatment compared to 29 of 53 (54.7%) BIVAD patients, p=0.24.
Table 1
shows common etiologies for patient sensitization of which only PRBC transfusion was statistically significant. [
table 1
] Multiple variable analysis comparing BIVAD vs. HMII while controlling for previous cardiac surgery, pregnancy, and PRBC transfusion demonstrated an Odds Ratio of 5.20, p=0.029 (robust variance estimator). Of sensitized patients, all 5 (100%) of the HMII patients had pre-existing antibodies prior to VAD placement compared to 11 of 29 (62.1%) BIVAD patients, p=0.016. Maximum cumulative MFIs for BIVAD were 46,259 ± 66,349 vs. 42540 ± 12840 for HMII, p=0.90. Time to maximum antibody expression was shorter for the HMII group (34 ± 28 days vs. 5.8 ± 9 days, p=0.04).
Table 1.
Sensitization Risk Factors
Antibodies +
Antibodies −
p-value
Previous Cardiac Surgery
23.5%
8.8%
0.19
Pregnancy
20.6%
2.9%
0.05
PRBC
52.1±34.7
35.9±22.3
0.04
FFP
29.4±14.4
23.6±15.2
0.15
Platelets
9.8±9.7
6.8±6.7
0.20
Cryoprecipitate
3.2±2.6
3.1±2.6
0.74
Blood products expressed as mean units ± std dev
Conclusion:
BIVADs were associated with a five fold increased risk for sensitization when accounting for other risk factors. HMII patients required pre-sensitization to express antibodies during their treatment interval whereas BIVAD patients developed
de novo
antibodies. Although the peak cumulative MFIs were similar for both VAD types, the days to reach this peak were significantly less in the HMII group. These data suggest that sensitization in HMII patients may not be due to antigenic stimulation from the device itself.
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19
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Chestovich PJ, Kwon MH, Cryer HG, Tillou A, Hiatt JR. Surgical procedures for patients receiving mechanical cardiac support. Am Surg 2011; 77:1314-1317. [PMID: 22127077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Mechanical cardiac support devices are used for patients with cardiopulmonary failure. We reviewed our institutional experience with noncardiac surgical procedures (NCPs) in patients supported by ventricular assist devices (VADs, n = 198) or extracorporeal membrane oxygenation (ECMO, n = 165) between July 1998 and June 2010. In total, 64 NCPs were performed in 55 VAD patients and 14 NCPs in 14 ECMO patients. Thirty-day mortality was higher for the VAD compared with the ECMO group (25 vs 86%; P < 0.001) and was greater for emergent compared with nonemergent procedures (58 vs 19%; P < 0.001). Excluding tracheostomy, no patients died within 30 days of a nonemergent procedure. Kaplan-Meier survival showed a trend toward worse survival after NCP in ECMO patients, but NCP did not alter survival in VAD patients. Fewer VAD patients were bridged to heart transplantation when NCP was required, and time from device implantation to transplant was significantly longer than for patients without NCP. In summary, this is the largest series of NCPs on VAD support and the only series on ECMO. Mortality is substantial for ECMO patients. Selected procedures can be performed safely in VAD patients but will delay heart transplantation.
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Affiliation(s)
- Paul J Chestovich
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California 90095-6904, USA
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20
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Abstract
Mechanical cardiac support devices are used for patients with cardiopulmonary failure. We reviewed our institutional experience with noncardiac surgical procedures (NCPs) in patients supported by ventricular assist devices (VADs, n = 198) or extracorporeal membrane oxygenation (ECMO, n = 165) between July 1998 and June 2010. In total, 64 NCPs were performed in 55 VAD patients and 14 NCPs in 14 ECMO patients. Thirty-day mortality was higher for the VAD compared with the ECMO group (25 vs 86%; P < 0.001) and was greater for emergent compared with nonemergent procedures (58 vs 19%; P < 0.001). Excluding tracheostomy, no patients died within 30 days of a nonemergent procedure. Kaplan-Meier survival showed a trend toward worse survival after NCP in ECMO patients, but NCP did not alter survival in VAD patients. Fewer VAD patients were bridged to heart transplantation when NCP was required, and time from device implantation to transplant was significantly longer than for patients without NCP. In summary, this is the largest series of NCPs on VAD support and the only series on ECMO. Mortality is substantial for ECMO patients. Selected procedures can be performed safely in VAD patients but will delay heart transplantation.
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Affiliation(s)
- Paul J. Chestovich
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Murray H. Kwon
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - H. Gill Cryer
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Areti Tillou
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Jonathan R. Hiatt
- Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California
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21
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Jang JY, Jeong JG, Jun HR, Lee SC, Kim JS, Kim YS, Kwon MH. A nucleic acid-hydrolyzing antibody penetrates into cells via caveolae-mediated endocytosis, localizes in the cytosol and exhibits cytotoxicity. Cell Mol Life Sci 2009; 66:1985-97. [PMID: 19373434 DOI: 10.1007/s00018-009-9179-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Many natural anti-DNA antibodies (Abs) have the ability to translocate across the plasma membrane and localize in the nucleus of mammalian cells, frequently leading to cytotoxicity to cells. Herein, we report detailed intracellular trafficking routes and cytotoxicity in HeLa cells for a single chain variable fragment (scFv) Ab, 3D8, which is an anti-DNA Ab capable of hydrolyzing both DNA and RNA. The intracellular penetration of 3D8 scFv occurred by caveolae/lipid raft endocytosis. The time-course chasing experiments revealed that 3D8 scFv escaped directly from the caveosome into the cytosol and remained in the cytosol without further trafficking into endosomes, lysosomes, endoplasmic reticulum, Golgi, or nucleus. The cytosolically localized 3D8 scFv maintained its nuclease activity to hydrolyze cellular RNAs, mainly mRNAs, eventually triggering apoptotic cell death. Our results demonstrate that 3D8 scFv has a unique intracellular trafficking route of localizing in the cytosol, thereby exhibiting cytotoxicity due to its nuclease activity.
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Affiliation(s)
- J Y Jang
- Department of Microbiology, Ajou University School of Medicine, Suwon, 443-721, Korea
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22
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Kwon MH, Moriguchi JD, Ardehali A, Jocson R, Marelli D, Laks H, Shemin RJ, Esmailian F. Use of ventricular assist device as a bridge to cardiac transplantation: impact of age and other determinants on outcomes. Tex Heart Inst J 2009; 36:214-219. [PMID: 19568390 PMCID: PMC2696504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We sought to compare outcomes in patients > or = 60 years of age with those of their younger counterparts who underwent ventricular assist device implantation intended as a bridge to cardiac transplantation and also to identify retrospectively additional pre- and postoperative factors that might portend adverse outcomes.The medical records of 88 patients who were treated with bridge-to-transplantation ventricular assist devices from 1996 through 2007 were reviewed. Laboratory values, hemodynamic parameters, and the need for hemodynamic support were evaluated. Postoperative complications and bridge-to-transplantation success rates versus death rates were evaluated. Seventeen patients were > or = 60 years old and 71 patients were < 60 years old. In the older group, 59% of patients underwent successful bridging to transplantation, compared with 69% of the younger patients (P = 0.41). Multivariate analysis distinguished age > or = 60, female sex, earlier time period of operation, higher mean pulmonary arterial and central venous pressures, need for preoperative intra-aortic balloon pumps, and postoperative respiratory failure as independent risk factors for death. After orthotopic heart transplantation, survival to hospital discharge was 100% in the older group and 93.9% in the younger patients. Median lengths of stay were similar in both age categories.Multivariate analysis identified age as 1 of 6 independent risk factors for death in this study. Patients who successfully underwent cardiac transplantation, however, had similar survival statistics regardless of age category. Case-by-case evaluation is warranted when analyzing risk-benefit ratios of bridge-to-transplantation ventricular assist device therapy in the older patient population.
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Affiliation(s)
- Murray H Kwon
- Divisions of Cardiothoracic Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA.
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23
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Marelli D, Esmailian F, Wong SY, Kobashigawa JA, Kwon MH, Beygui RE, Laks H, Plunkett MD, Ardehali A, Shemin RJ. Tricuspid valve regurgitation after heart transplantation. J Thorac Cardiovasc Surg 2008; 137:1557-9. [PMID: 19464484 DOI: 10.1016/j.jtcvs.2008.09.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [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: 04/15/2008] [Revised: 08/29/2008] [Accepted: 09/01/2008] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel Marelli
- Heart Transplant Program, David Geffen School of Medicine at the University of California, Los Angeles, Calif 90095-1741, USA
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24
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Hwang BS, Kwon MH, Kim J. Use of a near-field optical probe to locally launch surface plasmon polaritons on plasmonic waveguides: A study by the finite difference time domain method. Microsc Res Tech 2004; 64:453-8. [PMID: 15549697 DOI: 10.1002/jemt.20103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We used the finite difference time domain (FDTD) method to study the use of scanning near field optical microscopy (SNOM) to locally excite the nanometric plasmonic waveguides. In our calculation, the light is funneled through a SNOM probe with a sub-wavelength optical aperture and is irradiated on one end of two types of plasmonic waveguides made of 50 nm Au sphere arrays and Au nanowires. The incident light was well localized at one end of the waveguides and consequently propagated toward the other end, due to the excitation of surface plasmon polaritons. We found that the propagation length of the nanosphere array type waveguide varies from 100 to 130 nm depending on the light wavelength, the size of the probe aperture, and the launching heights. Our result shows that reducing the aperture size and using the light of the plasmon resonance wavelength of the nanosphere array could increase the propagation length and, thus, the efficiency of electromagnetic energy transportation through nanosphere arrays.
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Affiliation(s)
- B S Hwang
- Department of Physics, University of Incheon, Dohwa-dong 177, Nam-ku, Incheon 402-749, Korea
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25
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Kim SC, Jeon SH, Jung IR, Kim KH, Kwon MH, Kim JH, Yi JH, Kim SJ, You JC, Jung DH. Formation and emission status of PCDDs/PCDFs in municipal solid waste incinerators in Korea. Chemosphere 2001; 43:701-707. [PMID: 11372855 DOI: 10.1016/s0045-6535(00)00423-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This study was carried out to examine the formation and the emission status of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs) in the flue gases of commercial-scale municipal solid waste (MSW) incinerators, and thus to provide the engineering data for the reduction of PCDDs/PCDFs emitted from MSW incinerators. The formation concentrations of the PCDDs/PCDFs generated at the outlet of waste heat boilers (WHB) were in the range of 1.18-29.61 ng-TEQ/N m3 (average 5.75 ng-TEQ/N m3), while the emission concentrations at the stacks were in the range of 0.026-4.548 ng-TEQ/N m3 (average 0.924 ng-TEQ/N m3). Two major 2,3,7,8-substituted congeners were 2,3,4,7,8-PeCDF and 2,3,4,6,7,8-HxCDF, and their concentrations were up to 50% and 64% of total TEQ values at the outlet of WHB and the stack, respectively. From the results of multi-regression analysis, the formation concentration of PCDDs/PCDFs could be predicted as follows with the correlation factor of r2 = 0.962: PCDDs/PCDFs (ng-TEQ/N m3) = 3.036 (Cl) + 0.094 (T1) - 0.472 (Combustibles) + 0.059 (CO) - 0.039 (THC) - 3.366 (H) + 22.157, where T1 (degrees C) is the temperature at the outlet of the WHB. Cl, Combustibles and H are given as percentages and the others are in parts per million.
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Affiliation(s)
- S C Kim
- NIER (National Institute of Environmental Research), Seo-Ku, Inchon, South Korea.
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26
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Kim SC, Jeon SH, Jung IR, Kim KH, Kwon MH, Kim JH, Yi JH, Kim SJ, You JC, Jung DH. Removal efficiencies of PCDDs/PCDFs by air pollution control devices in municipal solid waste incinerators. Chemosphere 2001; 43:773-776. [PMID: 11372864 DOI: 10.1016/s0045-6535(00)00432-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Removal efficiencies of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs) by air pollution control devices (APCDs) in the commercial-scale municipal solid waste (MSW) incinerators with a capacity of above 200 ton/day were evaluated. The removal efficiencies of PCDDs/PCDFs were up to 95% when the activated carbon (AC) was injected in front of electrostatic precipitator (EP). Spray dryer absorber/bag filter (SDA/BF) had high removal efficiency (99%)) of PCDDs/PCDFs when a mixture of lime and AC was sprayed into the SDA. When the AC was not added in scrubbing solution, the whole congeners of PCDDs/PCDFs were enriched in the wet scrubber (WS) with negative removal efficiencies of -25% to -5731%. Discharge of PCDDs/PCDFs was decreased with increasing the proportions of AC added in scrubbing solution. Selective catalytic reduction (SCR) system had the removal efficiencies of up to 93% during the test operation.
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Affiliation(s)
- S C Kim
- National Institute of Environmental Research, NIER, Eunpyung-Ku, Seoul, South Korea
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27
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28
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Youn BS, Liu CC, Kim KK, Young JD, Kwon MH, Kwon BS. Structure of the mouse pore-forming protein (perforin) gene: analysis of transcription initiation site, 5' flanking sequence, and alternative splicing of 5' untranslated regions. J Exp Med 1991; 173:813-22. [PMID: 1840607 PMCID: PMC2190805 DOI: 10.1084/jem.173.4.813] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We studied the 5' untranslated regions (UTRs) of the mouse lymphocyte pore-forming protein (PFP, perforin, and cytolysin). 5' UTRs were determined by primer extension analysis, sequencing PFP cDNA clone PFP-7, ribonuclease protection assays, and amplification of poly(A)+ RNA of cytolytic T lymphocyte using polymerase chain reaction (PCR). Two alternatively spliced 5' UTRs, designated type I and type II, of 222 and 115 bp, respectively, were found associated with PFP. Type II is identical to type I, except for being 107 bp shorter in the second exon. This deletion was generated by the use of alternative acceptor splice sites. The mouse PFP gene (Pfp) encodes three exons, is separated by two small introns, and spans a chromosomal region of approximately 7 kb. The first exon contains 79 bp of 5' UTR, the second exon contains 143 or 36 bp of 5' UTR (type I or type II UTR, respectively) plus the NH2-terminal region of the mouse PFP, and the third exon contains the rest of the COOH-terminal mouse PFP. The organization of the mouse Pfp is similar to that of the human gene. Moreover, the 5' flanking sequence of the mouse Pfp is highly homologous to that of the human Pfp. In contrast to the human sequence, the more immediate 5' flanking sequence of mouse Pfp contains two tandem "TATA" box-related elements and a GC box, but lacks a typical CAAT box-related sequence. Several other enhancer elements were found further upstream, including cAMP-, phorbol ester-, interferon-gamma-, and UV-responsive elements, and PU box-like and NFkB binding site-like elements. In addition, we found a nuclear inhibitory protein-like element, a transcriptional silencer, and a pair of purine-rich sequence motifs that were found in other T cell-specific genes, and three repeats of GGCCTG that may be a variation of a highly repetitious GCCCTG consensus sequence found in human Pfp.
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Affiliation(s)
- B S Youn
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis 46202
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