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Kassardjian AA, Chat VS, Archuleta L, Hekmatjah J, Sierro TJ, Read C, Chen AY, Singh I, Armstrong AW. Words matter: a randomized controlled study evaluating the impact of decision-framing on treatment preferences in adults with psoriasis and psoriatic arthritis. Br J Dermatol 2021; 184:971-973. [PMID: 33332578 DOI: 10.1111/bjd.19746] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 12/11/2020] [Accepted: 12/12/2020] [Indexed: 11/27/2022]
Affiliation(s)
- A A Kassardjian
- Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - V S Chat
- Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - L Archuleta
- Department of Dermatology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - J Hekmatjah
- Western Michigan University, Homer Stryker M.D. School of Medicine, Kalamazoo, MI, USA
| | - T J Sierro
- Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - C Read
- Department of Dermatology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.,Department of Medicine, Imperial College London, London, UK
| | - A Y Chen
- Department of Dermatology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - I Singh
- Department of Dermatology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - A W Armstrong
- Department of Dermatology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
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2
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Chen AY, Zhu LL, Sun LG, Liu JB, Wang HT, Wang XY, Yang JH, Lu J. Scale law of complex deformation transitions of nanotwins in stainless steel. Nat Commun 2019; 10:1403. [PMID: 30926796 PMCID: PMC6440981 DOI: 10.1038/s41467-019-09360-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 02/27/2019] [Indexed: 11/09/2022] Open
Abstract
Understanding the deformation behavior of metallic materials containing nanotwins (NTs), which can enhance both strength and ductility, is useful for tailoring microstructures at the micro- and nano- scale to enhance mechanical properties. Here, we construct a clear deformation pattern of NTs in austenitic stainless steel by combining in situ tensile tests with a dislocation-based theoretical model and molecular dynamics simulations. Deformation NTs are observed in situ using a transmission electron microscope in different sample regions containing NTs with twin-lamella-spacing (λ) varying from a few nanometers to hundreds of nanometers. Two deformation transitions are found experimentally: from coactivated twinning/detwinning (λ < 5 nm) to secondary twinning (5 nm < λ < 129 nm), and then to the dislocation glide (λ > 129 nm). The simulation results are highly consistent with the observed strong λ-effect, and reveal the intrinsic transition mechanisms induced by partial dislocation slip.
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Affiliation(s)
- A Y Chen
- School of Materials Science and Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China.
| | - L L Zhu
- Department of Engineering Mechanics and Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Zhejiang University, Hangzhou, Zhejiang, 310027, China.,Center for X-Mechanics, Zhejiang University, Hangzhou, Zhejiang, 310027, China
| | - L G Sun
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong, China
| | - J B Liu
- Center for X-Mechanics, Zhejiang University, Hangzhou, Zhejiang, 310027, China.,School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China
| | - H T Wang
- Department of Engineering Mechanics and Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Zhejiang University, Hangzhou, Zhejiang, 310027, China.,Center for X-Mechanics, Zhejiang University, Hangzhou, Zhejiang, 310027, China
| | - X Y Wang
- School of Materials Science and Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China.
| | - J H Yang
- School of Materials Science and Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China
| | - J Lu
- Department of Mechanical Engineering, City University of Hong Kong, Hong Kong, China. .,Hong Kong Branch of National Precious Metals Material Engineering Research Centre, Department of Material Science and Engineering, City University of Hong Kong, Hong Kong, China.
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3
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Wayangankar SA, Roe MT, Chen AY, Gupta RS, Giugliano RP, Newby LK, de Lemos JA, Alexander KP, Sanborn TA, Saucedo JF. Trends in use of anti-thrombotic agents and outcomes in patients with non-ST-segment elevation myocardial infarction (NSTEMI) managed with an invasive strategy. Indian Heart J 2016; 68:464-72. [PMID: 27543467 PMCID: PMC4990733 DOI: 10.1016/j.ihj.2015.09.036] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 09/09/2015] [Accepted: 09/29/2015] [Indexed: 11/28/2022] Open
Abstract
Objective To analyze trends in utilization of anti-thrombotic agents (ATA) and in-hospital clinical outcomes in non-ST-elevation myocardial infarction (NSTEMI) patients managed with an invasive strategy from 2007 to 2010. Methods & results Using ACTION Registry®-GWTG™ data, we analyzed trends in use of ATA and in-hospital clinical outcomes among 64,199 NSTEMI patients managed invasively between 2007 and 2010. ATA included unfractionated heparin (UFH), low molecular weight heparin (LMWH), glycoprotein IIb/IIIa inhibitors (GPI) and bivalirudin. Although the proportion of NSTEMI patients treated with PCI within 48 h of hospital arrival was similar in 2007 and 2010, percentage use of bivalirudin (13.4–27.3%; p < 0.01) and UFH increased (60.0–67.5%, p < 0.01), and that of GPI (62.3–41.0%; p < 0.01) and LMWH (41.5–36.8%; p < 0.01) declined. Excess dosing of UFH (75.9–59.3%, p < 0.01), LMWH (9.6–5.2%; p < 0.01) and GPI (8.9–5.9%, p < 0.01) was also significantly lower in 2010 compared with 2007. Though in-hospital mortality rates were similar in 2007 and 2010 (2.3–1.9%, p = 0.08), the rates of in-hospital major bleeding (8.7–6.6%, p < 0.01) and non-CABG related RBC transfusion (6.3–4.6%, p < 0.01) were significantly lower in 2010 compared with 2007. Conclusion Compared with 2007, patients with NSTEMI, who were managed invasively in 2010 received GPI and LMWH less often and bivalirudin and UFH more frequently. There were sizeable reductions in the rates of excess dosing of UFH (though still occurred in 67% of patients), GPI and LMWH. In-hospital major bleeding complications and post-procedural RBC transfusion were lower in 2010 compared with 2007.
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Affiliation(s)
- S A Wayangankar
- Cleveland Clinic, Cleveland, OH, United States; Duke Clinical Research Institute, Durham, NC, United States; Deaconess Hospital, Oklahoma City, OK, United States; Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; University of Texas Southwestern Medical Center, Dallas, TX, United States; Northshore University Health System, Evanston, IL, United States.
| | - M T Roe
- Cleveland Clinic, Cleveland, OH, United States; Duke Clinical Research Institute, Durham, NC, United States; Deaconess Hospital, Oklahoma City, OK, United States; Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; University of Texas Southwestern Medical Center, Dallas, TX, United States; Northshore University Health System, Evanston, IL, United States
| | - A Y Chen
- Cleveland Clinic, Cleveland, OH, United States; Duke Clinical Research Institute, Durham, NC, United States; Deaconess Hospital, Oklahoma City, OK, United States; Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; University of Texas Southwestern Medical Center, Dallas, TX, United States; Northshore University Health System, Evanston, IL, United States
| | - R S Gupta
- Cleveland Clinic, Cleveland, OH, United States; Duke Clinical Research Institute, Durham, NC, United States; Deaconess Hospital, Oklahoma City, OK, United States; Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; University of Texas Southwestern Medical Center, Dallas, TX, United States; Northshore University Health System, Evanston, IL, United States
| | - R P Giugliano
- Cleveland Clinic, Cleveland, OH, United States; Duke Clinical Research Institute, Durham, NC, United States; Deaconess Hospital, Oklahoma City, OK, United States; Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; University of Texas Southwestern Medical Center, Dallas, TX, United States; Northshore University Health System, Evanston, IL, United States
| | - L K Newby
- Cleveland Clinic, Cleveland, OH, United States; Duke Clinical Research Institute, Durham, NC, United States; Deaconess Hospital, Oklahoma City, OK, United States; Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; University of Texas Southwestern Medical Center, Dallas, TX, United States; Northshore University Health System, Evanston, IL, United States
| | - J A de Lemos
- Cleveland Clinic, Cleveland, OH, United States; Duke Clinical Research Institute, Durham, NC, United States; Deaconess Hospital, Oklahoma City, OK, United States; Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; University of Texas Southwestern Medical Center, Dallas, TX, United States; Northshore University Health System, Evanston, IL, United States
| | - K P Alexander
- Cleveland Clinic, Cleveland, OH, United States; Duke Clinical Research Institute, Durham, NC, United States; Deaconess Hospital, Oklahoma City, OK, United States; Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; University of Texas Southwestern Medical Center, Dallas, TX, United States; Northshore University Health System, Evanston, IL, United States
| | - T A Sanborn
- Cleveland Clinic, Cleveland, OH, United States; Duke Clinical Research Institute, Durham, NC, United States; Deaconess Hospital, Oklahoma City, OK, United States; Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; University of Texas Southwestern Medical Center, Dallas, TX, United States; Northshore University Health System, Evanston, IL, United States
| | - J F Saucedo
- Cleveland Clinic, Cleveland, OH, United States; Duke Clinical Research Institute, Durham, NC, United States; Deaconess Hospital, Oklahoma City, OK, United States; Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; University of Texas Southwestern Medical Center, Dallas, TX, United States; Northshore University Health System, Evanston, IL, United States
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4
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Dai B, Chen AY, Corkum CP, Peroutka RJ, Landon A, Houng S, Muniandy PA, Zhang Y, Lehrmann E, Mazan-Mamczarz K, Steinhardt J, Shlyak M, Chen QC, Becker KG, Livak F, Michalak TI, Talwani R, Gartenhaus RB. Hepatitis C virus upregulates B-cell receptor signaling: a novel mechanism for HCV-associated B-cell lymphoproliferative disorders. Oncogene 2015; 35:2979-90. [PMID: 26434584 PMCID: PMC4821826 DOI: 10.1038/onc.2015.364] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 08/03/2015] [Accepted: 08/28/2015] [Indexed: 02/06/2023]
Abstract
B-cell receptor (BCR) signaling is essential for the development of B cells and has a critical role in B-cell neoplasia. Increasing evidence indicates an association between chronic hepatitis C virus (HCV) infection and B-cell lymphoma, however, the mechanisms by which HCV causes B-cell lymphoproliferative disorder are still unclear. Herein, we demonstrate the expression of HCV viral proteins in B cells of HCV-infected patients and show that HCV upregulates BCR signaling in human primary B cells. HCV nonstructural protein NS3/4A interacts with CHK2 and downregulates its activity, modulating HuR posttranscriptional regulation of a network of target mRNAs associated with B-cell lymphoproliferative disorders. Interestingly, the BCR signaling pathway was found to have the largest number of transcripts with increased association with HuR and was upregulated by NS3/4A. Our study reveals a previously unidentified role of NS3/4A in regulation of host BCR signaling during HCV infection, contributing to a better understanding of the molecular mechanisms underlying HCV-associated B-cell lymphoproliferative disorders.
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Affiliation(s)
- B Dai
- Department of Medicine, Marlene and Stewart Greenebaum Cancer Center, University of Maryland, Baltimore, MD, USA
| | - A Y Chen
- Molecular Virology and Hepatology Research Group, Division of BioMedical Sciences, Faculty of Medicine, Memorial University, St John's, Newfoundland and Labrador, Canada
| | - C P Corkum
- Molecular Virology and Hepatology Research Group, Division of BioMedical Sciences, Faculty of Medicine, Memorial University, St John's, Newfoundland and Labrador, Canada
| | - R J Peroutka
- Department of Medicine, Marlene and Stewart Greenebaum Cancer Center, University of Maryland, Baltimore, MD, USA
| | - A Landon
- Department of Medicine, Marlene and Stewart Greenebaum Cancer Center, University of Maryland, Baltimore, MD, USA
| | - S Houng
- Department of Medicine, Marlene and Stewart Greenebaum Cancer Center, University of Maryland, Baltimore, MD, USA
| | - P A Muniandy
- Department of Medicine, Marlene and Stewart Greenebaum Cancer Center, University of Maryland, Baltimore, MD, USA
| | - Y Zhang
- Gene Expression and Genomics Unit, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - E Lehrmann
- Gene Expression and Genomics Unit, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - K Mazan-Mamczarz
- Department of Medicine, Marlene and Stewart Greenebaum Cancer Center, University of Maryland, Baltimore, MD, USA
| | - J Steinhardt
- Department of Medicine, Marlene and Stewart Greenebaum Cancer Center, University of Maryland, Baltimore, MD, USA
| | - M Shlyak
- Department of Infectious Diseases, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Q C Chen
- Department of Pathology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - K G Becker
- Gene Expression and Genomics Unit, Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - F Livak
- Department of Medicine, Marlene and Stewart Greenebaum Cancer Center, University of Maryland, Baltimore, MD, USA
| | - T I Michalak
- Molecular Virology and Hepatology Research Group, Division of BioMedical Sciences, Faculty of Medicine, Memorial University, St John's, Newfoundland and Labrador, Canada
| | - R Talwani
- Department of Infectious Diseases, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - R B Gartenhaus
- Department of Medicine, Marlene and Stewart Greenebaum Cancer Center, University of Maryland, Baltimore, MD, USA.,Veterans Administration Medical Center, Baltimore, MD, USA
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5
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Aiken AH, Poliashenko S, Beitler JJ, Chen AY, Baugnon KL, Corey AS, Magliocca KR, Hudgins PA. Accuracy of Preoperative Imaging in Detecting Nodal Extracapsular Spread in Oral Cavity Squamous Cell Carcinoma. AJNR Am J Neuroradiol 2015; 36:1776-81. [PMID: 26228885 DOI: 10.3174/ajnr.a4372] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 03/03/2015] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The increasing impact of diagnosing extracapsular spread by using imaging, especially in patients with oropharyngeal squamous cell carcinoma, highlights the need to rigorously evaluate the diagnostic accuracy of imaging. Previous analysis suggested 62.5%-80.9% sensitivity and 60%-72.7% specificity. Our goals were to evaluate the accuracy of imaging in diagnosing extracapsular spread in a cohort of patients with oral cavity squamous cell carcinoma (pathologic confirmation of extracapsular spread routinely available), as a proxy for oropharyngeal squamous cell carcinoma, and to independently assess the reliability of imaging features (radiographic lymph node necrosis, irregular borders/stranding, gross invasion, and/or node size) in predicting pathologically proven extracapsular spread. MATERIALS AND METHODS One hundred eleven consecutive patients with untreated oral cavity squamous cell carcinoma and available preoperative imaging and subsequent lymph node dissection were studied. Two neuroradiologists blinded to pathologically proven extracapsular spread status and previous radiology reports independently reviewed all images to evaluate the largest suspicious lymph node along the expected drainage pathway. Radiologic results were correlated with pathologic results from the neck dissections. RESULTS Of 111 patients, 29 had radiographically determined extracapsular spread. Pathologic examination revealed that 28 of 111 (25%) had pathologically proven extracapsular spread. Imaging sensitivity and specificity for extracapsular spread were 68% and 88%, respectively. Radiographs were positive for lymph node necrosis in 84% of the patients in the pathology-proven extracapsular spread group and negative in only 7% of those in the pathologically proven extracapsular spread-negative group. On logistic regression analysis, necrosis (P = .001), irregular borders (P = .055), and gross invasion (P = .068) were independently correlated with pathologically proven extracapsular spread. CONCLUSIONS Although the specificity of cross-sectional imaging for extracapsular spread was high, the sensitivity was low. Combined logistic regression analysis found that the presence of necrosis was the best radiologic predictor of pathologically proven extracapsular spread, and irregular borders and gross invasion were nearly independently significant.
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Affiliation(s)
- A H Aiken
- From the Departments of Radiology and Imaging Sciences (J.J.B., A.H.A., A.S.C., K.L.B., P.A.H.)
| | - S Poliashenko
- Emory University School of Medicine (S.P.), Atlanta, Georgia
| | - J J Beitler
- From the Departments of Radiology and Imaging Sciences (J.J.B., A.H.A., A.S.C., K.L.B., P.A.H.) Otolaryngology Head and Neck Surgery (A.Y.C., J.J.B.) Radiation Oncology (J.J.B.), Hematology and Medical Oncology
| | - A Y Chen
- Otolaryngology Head and Neck Surgery (A.Y.C., J.J.B.)
| | - K L Baugnon
- From the Departments of Radiology and Imaging Sciences (J.J.B., A.H.A., A.S.C., K.L.B., P.A.H.)
| | - A S Corey
- From the Departments of Radiology and Imaging Sciences (J.J.B., A.H.A., A.S.C., K.L.B., P.A.H.)
| | | | - P A Hudgins
- From the Departments of Radiology and Imaging Sciences (J.J.B., A.H.A., A.S.C., K.L.B., P.A.H.)
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6
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Chen AY, Wilburn P, Hao X, Tully T. Walking deficits and centrophobism in an α-synuclein fly model of Parkinson's disease. Genes Brain Behav 2014; 13:812-20. [PMID: 25113870 PMCID: PMC4262005 DOI: 10.1111/gbb.12172] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 08/08/2014] [Accepted: 08/09/2014] [Indexed: 12/19/2022]
Abstract
Parkinson's disease (PD) is a movement neurodegenerative disorder, characterized by bradykinesia, rigidity and tremor, constituting difficulties in walking and abnormal gait. Previous research shows that Drosophila expressing human α-synuclein A30P (A30P) develop deficits in geotaxis climbing; however, geotaxis climbing is a different movement modality from walking. Whether A30P flies would exhibit abnormal walking in a horizontal plane, a measure more relevant to PD, is not known. In this study, we characterized A30P fly walking using a high-speed camera and an automatic behavior tracking system. We found that old but not young A30P flies exhibited walking abnormalities, specifically decreased total moving distance, distance per movement, velocity, angular velocity and others, compared with old control flies. Those features match the definition of bradykinesia. Multivariate analysis further suggested a synergistic effect of aging and A30P, resulting in a distinct pattern of walking deficits, as seen in aged A30P flies. Psychiatric problems are common in PD patients with anxiety affecting 40–69% of patients. Central avoidance is one assessment of anxiety in various animal models. We found old but not young A30P flies exhibited increased centrophobism, suggesting possible elevated anxiety. Here, we report the first quantitative measures of walking qualities in a PD fly model and propose an alternative behavior paradigm for evaluating motor functions apart from climbing assay.
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Affiliation(s)
- A Y Chen
- Dart Neuroscience LLC, San Diego, CA; Cold Spring Harbor Laboratory, Cold Spring Harbor, Stony Brook, NY; Graduate Program in Neuroscience, SUNY Stony Brook, Stony Brook, NY
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7
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Blandino-Rosano M, Alejandro EU, Sathyamurthy A, Scheys JO, Gregg B, Chen AY, Rachdi L, Weiss A, Barker DJ, Gould AP, Elghazi L, Bernal-Mizrachi E. Enhanced beta cell proliferation in mice overexpressing a constitutively active form of Akt and one allele of p21Cip. Diabetologia 2012; 55:1380-9. [PMID: 22327314 PMCID: PMC3646796 DOI: 10.1007/s00125-012-2465-9] [Citation(s) in RCA: 14] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 12/19/2011] [Indexed: 12/31/2022]
Abstract
AIMS/HYPOTHESIS The ability of pancreatic beta cells to proliferate is critical both for normal tissue maintenance and in conditions where there is an increased demand for insulin. Protein kinase B(Akt) plays a major role in promoting proliferation in many cell types, including the insulin-producing beta cells. We have previously reported that mice overexpressing a constitutively active form of Akt(caAkt (Tg)) show enhanced beta cell proliferation that is associated with increased protein levels of cyclin D1, cyclin D2 and cyclin-dependent kinase inhibitor 1A (p21(Cip)). In the present study, we sought to assess the mechanisms responsible for augmented p21(Cip) levels in caAkt(Tg) mice and test the role of p21(Cip) in the proliferative responses induced by activation of Akt signalling. METHODS To gain a greater understanding of the relationship between Akt and p21(Cip), we evaluated the mechanisms involved in the modulation of p2(Cip) by Akt and the in vivo role of reduced p21(Cip) in proliferative responses induced by Akt. RESULTS Our experiments showed that Akt signalling regulates p21(Cip) transcription and protein stability. caAkt(Tg) /p21(Cip+/-) mice exhibited fasting and fed hypoglycaemia as well as hyperinsulinaemia when compared with caAkt(Tg) mice. Glucose tolerance tests revealed improved glucose tolerance in caAkt(Tg)/p21(Cip+/-) mice compared with caAkt (Tg). These changes resulted from increased proliferation, survival and beta cell mass in caAkt(Tg)/p21(Cip+/-) compared with caAkt(Tg) mice. CONCLUSIONS/INTERPRETATION Our data indicate that increased p21(Cip) levels in caAkt(Tg) mice act as a compensatory brake, protecting beta cells from unrestrained proliferation. These studies imply that p21(Cip) could play important roles in the adaptive responses of beta cells to proliferate in conditions such as in insulin resistance.
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Affiliation(s)
- M. Blandino-Rosano
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - E. U. Alejandro
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - A. Sathyamurthy
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - J. O. Scheys
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - B. Gregg
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - A. Y. Chen
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - L. Rachdi
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - A. Weiss
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - D. J. Barker
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - A. P. Gould
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - L. Elghazi
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
| | - E. Bernal-Mizrachi
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, Brehm Center for Diabetes Research, University of Michigan Medical Center, Ann Arbor, MI 48109-0678, USA
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8
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Zhang EY, Xiong J, Parker BL, Chen AY, Fields PE, Ma X, Qiu J, Yankee TM. Depletion and recovery of lymphoid subsets following morphine administration. Br J Pharmacol 2012; 164:1829-44. [PMID: 21557737 DOI: 10.1111/j.1476-5381.2011.01475.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Opioid use and abuse has been linked to significant immunosuppression, which has been attributed, in part, to drug-induced depletion of lymphocytes. We sought to define the mechanisms by which lymphocyte populations are depleted and recover following morphine treatment in mice. EXPERIMENTAL APPROACH Mice were implanted with morphine pellets and B- and T-cell subsets in the bone marrow, thymus, spleen and lymph nodes were analysed at various time points. We also examined the effects of morphine on T-cell development using an ex vivo assay. KEY RESULTS The lymphocyte populations most susceptible to morphine-induced depletion were the precursor cells undergoing selection. As the lymphocytes recovered, more lymphocyte precursors proliferated than in control mice. In addition, peripheral T-cells displayed evidence that they had undergone homeostatic proliferation during the recovery phase of the experiments. CONCLUSIONS AND IMPLICATIONS The recovery of lymphocytes following morphine-induced depletion occurred in the presence of morphine and via increased proliferation of lymphoid precursors and homeostatic proliferation of T-cells.
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Affiliation(s)
- E Y Zhang
- Department of Microbiology, Molecular Genetics, and Immunology, University of Kansas Medical Center, Kansas City, KS 66160, USA
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Murphy BA, Chen AY, Curran WJ, Garden AS, Harari PM, Wong SJ, Bellm LA, Schwartz M, Newman J, Adkins D, Hayes DN, Parvathaneni U, Brachman D, Ghabach B, Schneider C, Greenberg M, Abitbol A, Anne PR, Ang KK. Longitudinal Oncology Registry of Head and Neck Carcinoma (LORHAN): Analysis of disparities in care. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.5533] [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] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Delano FA, Chen AY, Wu KIS, Tran ED, Rodrigues SF, Schmid-Schönbein GW. THE AUTODIGESTION HYPOTHESIS AND RECEPTOR CLEAVAGE IN DIABETES AND HYPERTENSION. ACTA ACUST UNITED AC 2011; 8:37-46. [PMID: 22081770 DOI: 10.1016/j.ddmod.2011.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
One of the key features of cardiovascular complications, such as hypertension or diabetes, is that they often appear at the same time in the same individual together with other forms of co-morbidities. While clinically a recognized phenomenon, no molecular mechanism for such co-morbidities has received universal acceptance. We propose a new hypothesis that provides a molecular basis for co-morbidities in hypertension due to unchecked proteolytic activity and receptor destruction. Testing of the hypothesis in the spontaneously hypertensive rat reveals an unchecked matrix metalloproteinase and serine protease activity in plasma and on several cardiovascular and parenchymal cells. The elevated proteolytic activity causes extracellular cleavage of multiple receptor types, such that cleavage of one receptor type leads to loss of the function carried out by this receptor. Proteolytic cleavage of the extracellular domain of the β(2) adrenergic receptor in arteries and arterioles causes vasoconstriction and elevation of the central blood pressure while cleavage of the extracellular domain of the insulin receptor leads to insulin resistance and lack of transmembrane glucose transport. A diverse set of cell dysfunctions in the spontaneously hypertensive rat are accompanied by cleavage of the membrane receptors that are involved in these functions. Chronic inhibition of the unchecked protease activity in the spontaneously hypertensive rat serves to restore the extracellular receptor density and alleviates the corresponding cell dysfunctions. The mild unchecked proteolytic activity in the spontaneously hypertensive rat points towards a chronic autodigestion process as a contributor to the end organ injury encountered in this rat strain. The presence of various soluble receptors, which consist of extracellular fragments of membrane receptors, in the plasma of hypertensive and diabetic patients suggest that the autodigestion process may also be present in man.
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Affiliation(s)
- F A Delano
- Department of Bioengineering, Institute for Engineering in Medicine, University of California San Diego, La Jolla, CA 92093 - 0412
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Virgo KS, Pavluck A, Chen AY, Marlow NM, Kirby H, Finney C, Ward EM. Impact of medicaid-enrollment status/timing on stage at diagnosis among male cancer patients. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.6038] [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] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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12
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Wong SJ, Chen AY, Curran WJ, Garden AS, Harari PM, Murphy BA, Bellm LA, Schwartz M, Ang K. Longitudinal Oncology Registry of Head and Neck Carcinoma (LORHAN): Findings related to the oropharynx. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.5585] [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] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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13
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Saba NF, Muller S, Chen AY, Grist W, Gibson K, Nannapaneni S, Yang CS, Khuri FR, Chen ZG, Shin DM. Chemoprevention with erlotinib and celecoxib in advanced premalignant lesions of the head and neck: Results of a phase I study. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.5535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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14
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Harari PM, Chen AY, Curran WJ, Garden AS, Murphy BA, Wong SJ, Bellm LA, Schwartz M, Schneider C, Ang K. Longitudinal Oncology Registry of Head and Neck Carcinoma (LORHAN): First overview of complete data set. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.5584] [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] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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15
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Curran WJ, Chen AY, Garden AS, Harari P, Murphy BA, Wong S, Bellm LA, Schwartz M, Dawson D, Ang KK. Longitudinal oncology registry of head and neck carcinoma (LORHAN): First report of outcomes. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.6071] [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] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
6071 Background: Registries can be invaluable for describing patterns of care and outcomes for a population of patients (pts). We report the initial survival findings from LORHAN, a prospective, longitudinal, observational national registry of head and neck carcinoma (HNC) pts. Methods: Pts are eligible for LORHAN if they have newly diagnosed HNC, are scheduled to receive radiotherapy (RT) or drug therapy, are ≥18 years of age and have provided written informed consent. Data are entered in the registry electronically and transferred via Secure HTTP protocols. Patient confidentiality is strictly maintained. Pts are followed from time of initial diagnosis and for a minimum of 2 and up to 10 years. When information is complete and has been verified and signed off by the investigator, a record is locked. Only locked records are summarized and reported. Results: 2,354 pts have been enrolled in LORHAN since Dec. 2005. Of these, 1,326 pts have completed initial cancer treatment and have locked records. 1- and 2-year follow-up data are available for 583 and 56 pts, respectively. Baseline characteristics were similar between settings, except that pts treated at academic centers were significantly younger (58 vs. 62 years of age), had poorer performance status (mean Zubrod: 0.9 vs. 0.7), had fewer laryngeal tumors (17% vs. 27% of pts) but more oropharyngeal tumors (42% vs. 37% of pts) and presented with more advanced disease (stage IV: 70% vs. 48% of pts) compared to pts treated in community. Treatment did not differ by setting. Treatment and survival data are shown below. Conclusions: LORHAN demonstrates it is feasible to collect more detailed information about patient and tumor features and treatment other than surgery. Changes in the pattern of care and survival findings are expected to emerge as newer regimens, including IC and targeted agents, are incorporated more broadly into clinical practice, and data in LORHAN matures. [Table: see text] [Table: see text]
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Affiliation(s)
- W. J. Curran
- Emory University, Atlanta, GA; UT M. D. Anderson Cancer Center, Houston, TX; University of Wisconsin, Madison, WI; Vanderbilt University, Nashville, TN; Medical College of Wisconsin, Milwaukee, WI; MedNet Solutions, Minnetonka, MN; ImClone Systems, Branchburg, NJ
| | - A. Y. Chen
- Emory University, Atlanta, GA; UT M. D. Anderson Cancer Center, Houston, TX; University of Wisconsin, Madison, WI; Vanderbilt University, Nashville, TN; Medical College of Wisconsin, Milwaukee, WI; MedNet Solutions, Minnetonka, MN; ImClone Systems, Branchburg, NJ
| | - A. S. Garden
- Emory University, Atlanta, GA; UT M. D. Anderson Cancer Center, Houston, TX; University of Wisconsin, Madison, WI; Vanderbilt University, Nashville, TN; Medical College of Wisconsin, Milwaukee, WI; MedNet Solutions, Minnetonka, MN; ImClone Systems, Branchburg, NJ
| | - P. Harari
- Emory University, Atlanta, GA; UT M. D. Anderson Cancer Center, Houston, TX; University of Wisconsin, Madison, WI; Vanderbilt University, Nashville, TN; Medical College of Wisconsin, Milwaukee, WI; MedNet Solutions, Minnetonka, MN; ImClone Systems, Branchburg, NJ
| | - B. A. Murphy
- Emory University, Atlanta, GA; UT M. D. Anderson Cancer Center, Houston, TX; University of Wisconsin, Madison, WI; Vanderbilt University, Nashville, TN; Medical College of Wisconsin, Milwaukee, WI; MedNet Solutions, Minnetonka, MN; ImClone Systems, Branchburg, NJ
| | - S. Wong
- Emory University, Atlanta, GA; UT M. D. Anderson Cancer Center, Houston, TX; University of Wisconsin, Madison, WI; Vanderbilt University, Nashville, TN; Medical College of Wisconsin, Milwaukee, WI; MedNet Solutions, Minnetonka, MN; ImClone Systems, Branchburg, NJ
| | - L. A. Bellm
- Emory University, Atlanta, GA; UT M. D. Anderson Cancer Center, Houston, TX; University of Wisconsin, Madison, WI; Vanderbilt University, Nashville, TN; Medical College of Wisconsin, Milwaukee, WI; MedNet Solutions, Minnetonka, MN; ImClone Systems, Branchburg, NJ
| | - M. Schwartz
- Emory University, Atlanta, GA; UT M. D. Anderson Cancer Center, Houston, TX; University of Wisconsin, Madison, WI; Vanderbilt University, Nashville, TN; Medical College of Wisconsin, Milwaukee, WI; MedNet Solutions, Minnetonka, MN; ImClone Systems, Branchburg, NJ
| | - D. Dawson
- Emory University, Atlanta, GA; UT M. D. Anderson Cancer Center, Houston, TX; University of Wisconsin, Madison, WI; Vanderbilt University, Nashville, TN; Medical College of Wisconsin, Milwaukee, WI; MedNet Solutions, Minnetonka, MN; ImClone Systems, Branchburg, NJ
| | - K. K. Ang
- Emory University, Atlanta, GA; UT M. D. Anderson Cancer Center, Houston, TX; University of Wisconsin, Madison, WI; Vanderbilt University, Nashville, TN; Medical College of Wisconsin, Milwaukee, WI; MedNet Solutions, Minnetonka, MN; ImClone Systems, Branchburg, NJ
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Virgo KS, Fedewa SA, Chen AY, Stewart AK, Flanders WD, Ward EM. Hospital characteristics associated with surgery for non-small cell lung cancer. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.6543] [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] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
6543 Background: Previous research suggests that black patients are less likely to undergo curative-intent surgery for early stage non-small cell lung cancer (NSCLC) compared to whites, holding all else constant. Among Medicare beneficiaries 65 and older, the likelihood of patients undergoing surgery is significantly reduced in hospitals with racial compositions of > 30% black patients after controlling for hospital and patient characteristics. This study analyzes whether hospital racial composition is associated with curative-intent surgery among early stage NSCLC patients of all ages. Methods: All adult patients ages 19–104 diagnosed with an invasive initial primary early stage (TNM I-II) NSCLC during 2003–2005 were selected from the National Cancer Data Base (NCDB). Facility characteristics were extracted from the NCDB and American College of Surgeons (ACoS) Commission on Cancer (CoC) Facility Information Profile System (FIPS). Hospital racial composition of lung cancer patients, operationalized as percent black, was initially divided into tertiles; sensitivity analyses used dichotomous definitions. Generalized estimating equations with a logistic model were used to control for clustering by facility. Results: Of 52,853 evaluable patients seen at CoC-approved hospitals, blacks were primarily (74%) seen at hospitals with a racial composition of > 11% black patients. Hispanics (72%), non-Hispanic whites (69%), and Asians or other (72%) were primarily seen at hospitals with < 11% black patients. In sensitivity analyses, irrespective of the cutpoint used to classify hospitals by racial composition of black patients (10, 20, or 30%), black patients seen at hospitals with a high black racial composition were significantly less likely to undergo curative-intent surgery than black patients seen at hospitals with a lower black racial composition. After controlling for patient characteristics in multivariate models, however, high black racial composition at the facility level was no longer significant. Conclusions: Hospital racial composition (% black) was not predictive of reduced likelihood of curative-intent surgery among patients > 18 years of age with NSCLC. Patient-level predictors accounted for the majority of the variation in likelihood of curative-intent surgery. No significant financial relationships to disclose.
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Affiliation(s)
- K. S. Virgo
- American Cancer Society & Emory University, Atlanta, GA; American College of Surgeons, Chicago, IL
| | - S. A. Fedewa
- American Cancer Society & Emory University, Atlanta, GA; American College of Surgeons, Chicago, IL
| | - A. Y. Chen
- American Cancer Society & Emory University, Atlanta, GA; American College of Surgeons, Chicago, IL
| | - A. K. Stewart
- American Cancer Society & Emory University, Atlanta, GA; American College of Surgeons, Chicago, IL
| | - W. D. Flanders
- American Cancer Society & Emory University, Atlanta, GA; American College of Surgeons, Chicago, IL
| | - E. M. Ward
- American Cancer Society & Emory University, Atlanta, GA; American College of Surgeons, Chicago, IL
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Newcomb WL, Polhill JL, Chen AY, Kuwada TS, Gersin KS, Getz SB, Kercher KW, Heniford BT. Staged hernia repair preceded by gastric bypass for the treatment of morbidly obese patients with complex ventral hernias. Hernia 2008; 12:465-9. [DOI: 10.1007/s10029-008-0381-1] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Accepted: 04/22/2008] [Indexed: 11/29/2022]
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18
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Sheu RJ, Chen AY, Liu YWH, Jiang SH. Shielding Calculations for a Spent Fuel Storage Cask: A Comparison of Discrete Ordinates, Monte Carlo, and Hybrid Methods. NUCL SCI ENG 2008. [DOI: 10.13182/nse159-23] [Citation(s) in RCA: 5] [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: 11/12/2022]
Affiliation(s)
- R. J. Sheu
- National Synchrotron Radiation Research Center 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu 300, Taiwan
| | - A. Y. Chen
- National Tsing-Hua University Department of Engineering and System Science, Hsinchu 300, Taiwan
| | - Y.-W. H. Liu
- National Tsing-Hua University Department of Engineering and System Science, Hsinchu 300, Taiwan
| | - S. H. Jiang
- National Tsing-Hua University Department of Engineering and System Science, Hsinchu 300, Taiwan
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Saravolatz LD, Billeter M, Zervos MJ, Chen AY, Dalovisio JR, Kurukularatne C. Dalbavancin: a Novel Once-Weekly Lipoglycopeptide Antibiotic. Clin Infect Dis 2008; 46:577-83. [DOI: 10.1086/526772] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Chen AY, Liu YWH, Sheu RJ. Radiation shielding evaluation of the BNCT treatment room at THOR: a TORT-coupled MCNP Monte Carlo simulation study. Appl Radiat Isot 2008; 66:28-38. [PMID: 17825572 DOI: 10.1016/j.apradiso.2007.07.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2007] [Revised: 07/01/2007] [Accepted: 07/13/2007] [Indexed: 10/23/2022]
Abstract
This study investigates the radiation shielding design of the treatment room for boron neutron capture therapy at Tsing Hua Open-pool Reactor using "TORT-coupled MCNP" method. With this method, the computational efficiency is improved significantly by two to three orders of magnitude compared to the analog Monte Carlo MCNP calculation. This makes the calculation feasible using a single CPU in less than 1 day. Further optimization of the photon weight windows leads to additional 50-75% improvement in the overall computational efficiency.
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Affiliation(s)
- A Y Chen
- Department of Engineering and System Science, National Tsing-Hua University, Hsinchu 30013, Taiwan, ROC
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Abstract
The increasing incidence of serious infections because of Gram-positive pathogens and the rising cost in parenteral administration of antimicrobials has inspired the development of a novel antibiotic. Dalbavancin is the first once a week antibiotic with activity against a broad range of Gram-positive pathogens. A large multicentre, pivotal, Phase III clinical trial, which included 854 patients with complicated skin and skin structure infections, compared 1-2 doses of dalbavancin vs. linezolid. The results demonstrated non-inferiority and a comparable safety profile. With its unique pharmacokinetic profile, ease of use and excellent safety profile, dalbavancin should provide a valuable addition to the armamentarium used to treat infections because of Gram-positive cocci.
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Affiliation(s)
- A Y Chen
- Wayne State University School of Medicine, Division of Infectious Diseases, Henry Ford Hospital, Detroit, MI 48202, USA
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22
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Wong GK, Chen AY, Ha S, Kruhlak R, Murdoch S, Leonhardt R, Harvey J, Joly N. Characterization of chromatic dispersion in photonic crystal fibers using scalar modulation instability. Opt Express 2005; 13:8662-8670. [PMID: 19498897 DOI: 10.1364/opex.13.008662] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A simple and accurate method is proposed for characterizing the chromatic dispersion of high air-filling fraction photonic crystal fibers. The method is based upon scalar modulation instability generated by a strong pump wave propagating near the zero-dispersion wavelength. Measuring the modulation instability sideband frequency shifts as a function of wavelength gives a direct measurement of the fiber's chromatic dispersion over a wide wavelength range. To simplify the dispersion calculation we introduce a simple analytical model of the fiber's dispersion, and verify its accuracy via a full numerical simulation. Measurements of the chromatic dispersion of two different types of high air-filling fraction photonic crystal fibers are presented.
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23
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Jacobson KL, Connolly MJ, Chen AY, Johnstone PAS. Health literacy and quality of life in an inner city laryngectomy population. J Clin Oncol 2005. [DOI: 10.1200/jco.2005.23.16_suppl.8191] [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] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- K. L. Jacobson
- Rollins Sch of Public Health, Emory Univ, Atlanta, GA; Emory Univ Sch of Medicine, Atlanta, GA
| | - M. J. Connolly
- Rollins Sch of Public Health, Emory Univ, Atlanta, GA; Emory Univ Sch of Medicine, Atlanta, GA
| | - A. Y. Chen
- Rollins Sch of Public Health, Emory Univ, Atlanta, GA; Emory Univ Sch of Medicine, Atlanta, GA
| | - P. A. S. Johnstone
- Rollins Sch of Public Health, Emory Univ, Atlanta, GA; Emory Univ Sch of Medicine, Atlanta, GA
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Affiliation(s)
| | | | - D. Lau
- UC Davis Medcl Ctr, Sacramento, CA
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25
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Abstract
BACKGROUND The purpose of this study was to determine whether coronary artery bypass grafting without cardiopulmonary bypass (off-pump CABG) decreases risk-adjusted operative death and major complications after coronary artery bypass grafting in selected patients. METHODS Using The Society of Thoracic Surgeons (STS) National Adult Cardiac Surgery Database, procedural outcomes were compared for conventional and off-pump CABG procedures from January 1, 1998, through December 31, 1999. Mortality and major complications were examined, both as unadjusted rates and after adjusting for known base line patient risk factors. RESULTS A total of 126 experienced centers performed 118,140 total CABG procedures. The number of off-pump CABG cases was 11,717 cases (9.9% of total cases). The use of an off-pump procedure was associated with a decrease in risk-adjusted operative mortality from 2.9% with conventional CABG to 2.3% in the off-pump group (p < 0.001). The use of an off-pump procedure decreased the risk-adjusted major complication rate from 14.15% with conventional CABG to 10.62% in the off-pump group (p < 0.0001). Patients receiving off-pump procedures were less likely to die (adjusted odds ratio 0.81, 95% CI 0.70 to 0.91) and less likely to have major complications (adjusted odds ratio 0.77, 95% CI 0.72 to 0.82). CONCLUSIONS Off-pump CABG is associated with decreased mortality and morbidity after coronary artery bypass grafting. Off-pump CABG may prove superior to conventional CABG in appropriately selected patients.
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Affiliation(s)
- J C Cleveland
- Division of Cardiothoracic Surgery, University of Colorado Health Sciences Center, Denver 80262, USA.
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Ahmad S, Doweyko LM, Dugar S, Grazier N, Ngu K, Wu SC, Yost KJ, Chen BC, Gougoutas JZ, DiMarco JD, Lan SJ, Gavin BJ, Chen AY, Dorso CR, Serafino R, Kirby M, Atwal KS. Arylcyclopropanecarboxyl guanidines as novel, potent, and selective inhibitors of the sodium hydrogen exchanger isoform-1. J Med Chem 2001; 44:3302-10. [PMID: 11563929 DOI: 10.1021/jm010100v] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [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: 11/29/2022]
Abstract
A novel series of arylcyclopropanecarboxyl guanidines was synthesized and evaluated for activity against the sodium hydrogen exchanger isoform-1 (NHE-1). In biological assays conducted in an AP1 cell line expressing the human NHE-1 isoform, the starting cyclopropane 3a (IC(50) = 3.5 microM) shows inhibitory activity comparable to cariporide (IC(50) = 3.4 microM). Structure-activity relationships are used to optimize the affinity of various acyl guanidines for NHE-1 by screening the effect of substituents at both aryl and cyclopropyl rings. It is demonstrated that introduction of appropriate hydrophobic groups at the phenyl ring and a gem-dimethyl group at the cyclopropane ring enhances the NHE-1 inhibitory activity by up to 3 orders of magnitude (compound 7f, IC(50) = 0.003 microM). In addition, the gem-dimethyl series of analogues seem to display improved oral bioavailability and longer plasma half-life in rats. Furthermore, the lead benzodihydrofuranyl analogue 1 (BMS-284640) shows over 380-fold increased NHE-1 inhibitory activity as well as improved selectivity for NHE-1 over NHE-2 compared to cariporide.
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Affiliation(s)
- S Ahmad
- Bristol-Myers Squibb Pharmaceutical Research Institute, P.O. Box 4000, Princeton, NJ 08543, USA.
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Borgatta L, Chen AY, Reid SK, Stubblefield PG, Christensen DD, Rashbaum WK. Pelvic embolization for treatment of hemorrhage related to spontaneous and induced abortion. Am J Obstet Gynecol 2001; 185:530-6. [PMID: 11568773 DOI: 10.1067/mob.2001.116750] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [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: 11/22/2022]
Abstract
OBJECTIVE Presentation of outcomes of pelvic arterial embolization for hemorrhage after spontaneous or induced abortion. STUDY DESIGN We collected case reports of embolization after spontaneous or induced abortion from oral presentations and from members of the National Abortion Federation. RESULTS Pelvic arterial embolization was performed for 11 women who had hemorrhage after spontaneous or induced abortion, and it was initially successful for all women. One woman ultimately required a hysterectomy after unsuccessful repeated embolization. Prophylactic embolization was done for 8 women who were at risk for hemorrhage from placenta accreta; 4 of these women had subsequent hysterectomies. CONCLUSIONS Selective pelvic arterial embolization may be a successful treatment for hemorrhage associated with spontaneous and induced abortion. Embolization can be considered before hysterectomy is undertaken for control of hemorrhage. There may be a role for prophylactic catheterization or embolization when there is a risk of severe hemorrhage.
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Affiliation(s)
- L Borgatta
- Department of Obstetrics and Gynecology, Boston University School of Medicine, MA 02118, USA.
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Abstract
BACKGROUND Breast carcinoma and thyroid carcinoma are two malignancies that occur most commonly in women. An association between the incidence rates of thyroid and breast carcinoma in women after a diagnosis of the other malignancy has been suggested in a retrospective analysis of a single institution's tumor registry. In that study, an increased incidence of breast carcinoma in premenopausal women previously treated for thyroid carcinoma was observed. METHODS The purpose of this study was to investigate further this relation utilizing a large database, the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) database. The SEER database is maintained by the National Cancer Institute, and it represents 11 population-based cancer registries covering approximately 14% of the United States population. The study was a population-based retrospective cohort analysis using external comparisons. From 1973 to 1994, 365 women in the SEER database were identified as having both thyroid and breast carcinomas. The SEER database from 1973 to 1994 was utilized to calculate age specific and calendar year specific incidence rates for each year for thyroid and breast carcinomas. The expected number of second cancers for each age group, calendar year, and follow-up period were determined by multiplying these incidence rates by the age specific and calendar year specific number of person-years at risk. The risk ratio (RR) was calculated by dividing the observed by the expected number of second cancers. Statistical significance was determined by the Poisson test. RESULTS A total of 1,333,115 person-years were available for analysis. One hundred thirteen thyroid carcinoma cases were diagnosed after breast carcinoma cases (RR, 0.99; P = 0.576). Two hundred fifty-two breast carcinoma cases were diagnosed after thyroid carcinoma cases (RR, 1.18; P = 0.007). Premenopausal women (age 20-49 years) with an index thyroid carcinoma have a significantly increased risk of developing subsequent breast carcinoma (RR, 1.42; P = 0.001). Black premenopausal women with an index thyroid carcinoma do not have an increased risk of developing breast carcinoma, but the statistical power is lower due to low numbers. No women with index breast carcinoma have an increased risk of developing thyroid carcinoma. CONCLUSIONS Women with a history of thyroid carcinoma have a greater than expected risk of developing breast carcinoma. This risk is most pronounced in premenopausal white women. The implications of this observation with respect to breast carcinoma screening guidelines and thyroid carcinoma treatment guidelines deserve further investigation.
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Affiliation(s)
- A Y Chen
- Department of Head and Neck Surgery, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA
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Chen AY, Frankowski R, Bishop-Leone J, Hebert T, Leyk S, Lewin J, Goepfert H. The development and validation of a dysphagia-specific quality-of-life questionnaire for patients with head and neck cancer: the M. D. Anderson dysphagia inventory. Arch Otolaryngol Head Neck Surg 2001; 127:870-6. [PMID: 11448365] [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] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
OBJECTIVE To design a reliable and validated self-administered questionnaire whose purpose is to assess dysphagia's effects on the quality of life (QOL) of patients with head and neck cancer. DESIGN Cross-sectional survey study. METHODS Focus groups were convened for questionnaire development and design. The M. D. Anderson Dysphagia Inventory (MDADI) included global, emotional, functional, and physical subscales. One hundred consecutive adult patients with a neoplasm of the upper aerodigestive tract who underwent evaluation by our Speech Pathology team completed the MDADI and the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36). Speech pathologists completed the Performance Status Scale for each patient. Validity and reliability properties were calculated. Analysis of variance was used to assess how well the MDADI discriminated between groups of patients. RESULTS The internal consistency reliability of the MDADI was calculated using the Cronbach alpha coefficient. The Cronbach alpha coefficients of the MDADI subscales ranged from 0.85 to 0.93. Test-retest reliability coefficients of the subscales ranged from 0.69 to 0.88. Spearman correlation coefficients between the MDADI subscales and the SF-36 subscales demonstrated construct validity. Patients with primary tumors of the oral cavity and oropharynx had significantly greater swallowing disability with an adverse impact on their QOL compared with patients with primary tumors of the larynx and hypopharynx (P<.001). Patients with a malignant lesion also had significantly greater disability than patients with a benign lesion (P<.001). CONCLUSIONS The MDADI is the first validated and reliable self-administered questionnaire designed specifically for evaluating the impact of dysphagia on the QOL of patients with head and neck cancer. Standardized questionnaires that measure patients' QOL offer a means for demonstrating treatment impact and improving medical care. The development and validation of the MDADI and its use in prospective clinical trials allow for better understanding of the impact of treatment of head and neck cancer on swallowing and of swallowing difficulty on patients' QOL.
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Affiliation(s)
- A Y Chen
- Department of Head and Neck Surgery, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd, Campus Box 441, Houston, TX 77030, USA
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Abstract
INTRODUCTION Cancer patients often have concurrent diseases and conditions known as comorbidities. The aim of this project is to demonstrate the significance of comorbidity in the treatment and outcomes of advanced laryngeal carcinoma. METHODS A retrospective medical record review of 182 patients with previously untreated T3 or T4 squamous carcinomas of the larynx treated at M. D. Anderson between 1990 and 1995 was performed. Demographic, patient-specific, tumor-specific, and outcome measures information were collected. Comorbidity was coded using the Modified Medical Comorbidity Index. Univariate and multivariate analysis with the use of life survival analysis techniques and logistic regression were performed. RESULTS The median age at diagnosis was 59.5 years. Most patients were men (69.2%) and Caucasian (73.1%). Laryngeal preservation was performed in 90 patients, and surgical resection was performed in 92 patients. Patients in the two treatment groups had similar comorbidity, locoregional control (65%), and 5-year survival (37.3%). Patients with either moderate or severe comorbidity had significantly worse overall survival (p = .00014) and worse 5-year survival than those with no or mild comorbidity (21.8% vs 46.3%, p = .003). CONCLUSIONS This study demonstrates that comorbidity is significantly associated with survival in a group of patients with identical histology, site, and stage. Comorbid status should be incorporated into the assessment of prognosis and outcome to improve and optimize the management of head and neck cancer patients.
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Affiliation(s)
- A Y Chen
- Department of Head and Neck Surgery, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd., Box 69, Houston, Texas 77030, USA
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Affiliation(s)
- A Y Chen
- Department of Head and Neck Surgery, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
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Wang H, Mao Y, Chen AY, Zhou N, LaVoie EJ, Liu LF. Stimulation of topoisomerase II-mediated DNA damage via a mechanism involving protein thiolation. Biochemistry 2001; 40:3316-23. [PMID: 11258951 DOI: 10.1021/bi002786j] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The breakage/reunion reaction of DNA topoisomerase II (TOP2) can be interrupted by DNA intercalators (e.g., doxorubicin), enzyme binders (e.g., etoposide), or DNA lesions (e.g., abasic sites) to produce TOP2-mediated DNA damage. Here, we demonstrate that thiol alkylation of TOP2 can also produce TOP2-mediated DNA damage. This conclusion is supported by the following observations using purified TOP2: (1) Thiol-reactive quinones were shown to induce TOP2-mediated DNA cleavage. (2) Thiol-reactive compounds such as N-ethylmaleimide (NEM), disulfiram, and organic disulfides [e.g., 2,2'-dithiobis(5-nitropyridine)] were also shown to induce TOP2-mediated DNA cleavage with similar reaction characteristics as thiol-reactive quinones. (3) TOP2-mediated DNA cleavage induced by thiol-reactive quinones was completely abolished using mutant yeast TOP2 with all cysteine residues replaced with alanine (cysteineless TOP2). These results suggest the possibility that cellular DNA damage could occur indirectly through thiolation of a nuclear protein, TOP2. The implications of this reaction in carcinogenesis and apoptotic cell death are discussed.
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Affiliation(s)
- H Wang
- Department of Pharmacology, University of Medicine & Dentistry of New Jersey-Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, New Jersey 08854-5635, USA
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Chen AY, Scruggs PB, Geng L, Rothenberg ML, Hallahan DE. p53 and p21 are major cellular determinants for DNA topoisomerase I-mediated radiation sensitization in mammalian cells. Ann N Y Acad Sci 2001; 922:298-300. [PMID: 11193905 DOI: 10.1111/j.1749-6632.2000.tb07047.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- A Y Chen
- Department of Radiation Oncology, Vanderbilt University Medical Center, 1301 22nd Ave. S., Vanderbilt Clinic, Nashville, TN 37232-5671, USA.
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Affiliation(s)
- A Y Chen
- Department of Head and Neck Surgery, University of Texas M. D. Anderson Cancer Center, Houston, USA
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Abstract
OBJECTIVE Previous studies have shown that children with congenital heart disease (CHD) who live in nonurban areas or who do not have private insurance are at risk for delayed referral to a pediatric cardiologist. However, the effect of these factors on the age at which cardiac surgery is performed has not been evaluated. This study is designed to evaluate the factors that influence the age at which definitive surgical repair is performed. METHODS Data on hospital discharges for 1995 and 1996 in California were obtained from the Office of Statewide Health Planning and Development database. Children <18 years who underwent surgical repair for atrial septal defect (ASD), ventricular septal defect (VSD), tetralogy of Fallot (TOF), or atrioventricular canal (AVC) were included in the study. Age at surgery was evaluated using type of CHD, gender, race, type of insurance, surgical centers, urban or rural home location, and distance between home and surgical center as independent variables. RESULTS In 1995-1996, 666 children underwent ASD closure (mean age: 5.1 years; median: 4.0 years), 582 VSD closure (mean age: 2.8; median: 1.1 years), 394 TOF repair (mean age: 1.7; median:.9 years), and 177 AVC repair (mean age: 1.1; median:.6 years). Comparing median and mean age at surgery, we found: AVC<TOF<VSD<ASD (< indicates younger than). A consistent trend for all 4 types of CHD was seen indicating that for median age at operation: private insurance<managed care<Medicaid. Gender or race had no effect on age at operation, although Asians tended to be older at surgery for all 4 types of CHD. There is a significant negative correlation between the case volume of surgical centers and median age at operation for ASD (r = -.37), VSD (r = -.49), TOF (r = -.63), and AVC (r = -.17). In addition, significant positive correlation was found between degree of urbanization of home locations (measured by population density) and median age at operation for ASD (r =.50), VSD (r =.77), and TOF (r =.18). No significant correlation was found between distance to surgical center and age at operation. CONCLUSIONS Many medical and nonmedical variables play important roles in determining age for definitive repair of CHD in children. Type of insurance, a recognized surrogate for access to care, may play an important role. In addition, centers with higher surgical case volume were more likely to operate at a younger age. Finally, children in urban areas tend to be older at the time of surgery for ASD, VSD, and TOF.
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Affiliation(s)
- R K Chang
- Division of Cardiology, Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, California 90509, USA.
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Chen AY, Callender D, Mansyur C, Reyna KM, Limitone E, Goepfert H. The impact of clinical pathways on the practice of head and neck oncologic surgery: the University of Texas M. D. Anderson Cancer Center Experience. Arch Otolaryngol Head Neck Surg 2000; 126:322-6. [PMID: 10722004 DOI: 10.1001/archotol.126.3.322] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To assess the impact of clinical pathways on the practice of head and neck oncologic surgery in an academic center. DESIGN Cross-sectional study. SETTING Cancer treatment center. PATIENTS The study population consisted of 3 groups of patients who underwent unilateral neck dissection and were treated in the Department of Head and Neck Surgery of the University of Texas M. D. Anderson Cancer Center, Houston. Additional procedures which may have been performed were direct laryngoscopy, rigid esophagoscopy, and/or dental extractions. Ninety-six patients treated during 1993-1994 prior to the implementation of the clinical pathway (historical control group) were compared with 94 patients treated during 1996-1998, 64 who were not (contemporaneous nonpathway group) and 30 who were managed on the clinical pathway (pathway group). Patients from 1995 were excluded since the pathway was in the planning stages then. MAIN OUTCOME MEASURES Median length of stay; median total costs of care. RESULTS The median length of hospital stay of the historical control, contemporaneous nonpathway, and pathway groups decreased from 4.0 to 2.0 days (P<.001). The total median costs of care were less in the pathway group as compared with the historical control group ($6,227 and $8,459, respectively, P<.001) and also less in the contemporaneous nonpathway group compared with the historical control group (S6885 and $8,459, respectively, P<.001). Mean and median length of hospital stay and costs were lower in the pathway group as compared with the nonpathway group but not significantly (P = .11 and P = .07, respectively) The contemporaneous nonpathway and pathway groups did not differ in complications or readmissions. CONCLUSIONS Development and implementation of this clinical pathway played a statistically significant role in decreasing length of hospital stay and total costs of care associated with neck dissection between nonpathway and pathway patients. Thus, a more cost-effective practice environment has resulted for all of our patients.
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Affiliation(s)
- A Y Chen
- University of Texas M.D. Anderson Cancer Center, Department of Head and Neck Surgery, Houston 77030, USA
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Ribas A, Butterfield LH, Hu B, Dissette VB, Chen AY, Koh A, Amarnani SN, Glaspy JA, McBride WH, Economou JS. Generation of T-cell immunity to a murine melanoma using MART-1-engineered dendritic cells. J Immunother 2000; 23:59-66. [PMID: 10687138 DOI: 10.1097/00002371-200001000-00008] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The murine melanoma B16 expresses the murine counterpart of the human MART-1/Melan-A (MART-1) antigen, sharing a 68.6% amino acid sequence identity. In this study, mice were vaccinated with bone marrow-derived murine dendritic cells genetically modified with a replication-incompetent adenoviral vector to express the human MART-1 gene (AdVMART1). This treatment generated a protective response to a lethal tumor challenge of unmodified murine B16 melanoma cells. The response was mediated by major histocompatibility complex class I-restricted cytotoxic T lymphocytes specific for MART-1 antigen, which produced high levels of interferon-gamma when reexposed to MART-1 in vitro and lysed targets in a calcium-dependent mechanism suggestive of perforin/granzyme B lysis. MART-1 was presented by the dendritic cells used for vaccination and not by epitopes cross-presented by host antigen-presenting cells. In conclusion, dendritic cells genetically modified to express the human MART-1 antigen generate potent murine MART-1-specific protective responses to B16 melanoma.
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Affiliation(s)
- A Ribas
- Division of Surgical Oncology, University of California, Los Angeles, USA
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Ribas A, Butterfield LH, McBride WH, Dissette VB, Koh A, Vollmer CM, Hu B, Chen AY, Glaspy JA, Economou JS. Characterization of antitumor immunization to a defined melanoma antigen using genetically engineered murine dendritic cells. Cancer Gene Ther 1999; 6:523-36. [PMID: 10608349 DOI: 10.1038/sj.cgt.7700076] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A murine model of dendritic cell (DC)-based genetic immunization to a defined human melanoma antigen (Ag), MART-1/Melan-A (MART-1), was developed. The MART-1 gene was stably transfected into the nonimmunogenic mouse fibrosarcoma cell line NFSA that is syngeneic in C3Hf/Sem/Kam (C3H, H-2k) mice to generate the NFSA(MART1) cell line. In vivo protection from a lethal NFSA(MART1) tumor challenge could be generated by DCs transduced with a recombinant adenovirus (AdV) vector expressing MART-1 (AdVMART1). This model has the following characteristics: (a) immunological specificity and memory, (b) comparable protection for varying transduction multiplicities of infection, cell doses, and sites of DC inoculation but, interestingly, worse protection with increasing numbers of vaccinations, (c) the ability to treat small established tumors, (d) an absolute requirement for CD8 and CD4 T cells, (e) generation of MART-1-specific splenic cytotoxic T lymphocytes, and (f) up-regulation of both T helper type 1 and T helper type 2 cytokines. Genetically engineered DCs presenting defined tumor Ags represent an attractive method to generate effective immune responses.
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Affiliation(s)
- A Ribas
- Division of Surgical Oncology, University of California, Los Angeles 90095, USA
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Hallahan DE, Chen AY, Teng M, Cmelak AJ. Drug-radiation interactions in tumor blood vessels. Oncology (Williston Park) 1999; 13:71-7. [PMID: 10550829] [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] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Obliteration of the tumor vasculature is an effective means of achieving tumor regression. Antiangiogenic agents have begun to enter cancer clinical trials. Ionizing radiation activates the inflammatory cascade and increases the procoagulative state within blood vessels of both tumors and normal tissues. These responses are mediated through oxidative injury to the endothelium, leading to induction of cell-adhesion molecules and exocytosis of stored proteins from the endothelial cytoplasm. Agents that activate homeostatic responses in the endothelium can enhance thrombosis and vasculitis of irradiated tumor blood vessels. Proinflammatory and prothrombotic biological response modifiers given concurrently with ionizing radiation are known to induce vascular obliteration and necrosis of tumors. Other mechanisms of interaction between antiangiogenic agents and ionizing radiation include the direct cytotoxic effects of these agents. Interactions between drugs and radiation therapy might therefore occur at the level of the vascular endothelium. The importance of this paradigm is that the endothelium might not develop resistance to drugs or radiation because of lessened potential for mutagenesis and clonogenesis. The future design of clinical trials must consider the effects of radiation therapy on the vascular endothelium.
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Affiliation(s)
- D E Hallahan
- Department of Biomedical Engineering, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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40
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Chen AY, Choy H, Rothenberg ML. DNA topoisomerase I-targeting drugs as radiation sensitizers. Oncology (Williston Park) 1999; 13:39-46. [PMID: 10550825] [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] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Combination chemoradiation, alone or as an adjuvant to surgery, has been shown to improve treatment outcomes in a number of human malignancies, but may be limited by normal tissue toxicities. A primary challenge in radiation oncology is the development of drugs that can selectively enhance the cytotoxicity of ionizing radiation against tumor cells. Mammalian DNA topoisomerase I is the major cytotoxic target of a number of newly developed anticancer drugs that have shown efficacy against solid tumors, including colon cancer, ovarian cancer, lung cancer, cancer of the head and neck, and pediatric cancers. Topoisomerase I-targeting drugs exert their cytotoxic effect by producing enzyme-mediated DNA damage, rather than by directly inhibiting enzyme catalytic activity. DNA topoisomerase I recently has been established as a biochemical mediator of radiosensitization in cultured mammalian cells by camptothecin derivatives. Interestingly, this sensitization appears to be schedule-dependent, cell cycle phase-specific, cell line-dependent, and not strictly dependent on drug cytotoxicity. Clinical chemoradiation trials using camptothecin derivatives are currently ongoing. Future studies aimed at better understanding the underlying mechanisms of molecular radiosensitization with topoisomerase I-targeting drugs are pivotal to the clinical application of these agents, as well as in guiding the development of more effective radiosensitizers.
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Affiliation(s)
- A Y Chen
- Drug Discovery Laboratory, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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Vollmer CM, Ribas A, Butterfield LH, Dissette VB, Andrews KJ, Eilber FC, Montejo LD, Chen AY, Hu B, Glaspy JA, McBride WH, Economou JS. p53 selective and nonselective replication of an E1B-deleted adenovirus in hepatocellular carcinoma. Cancer Res 1999; 59:4369-74. [PMID: 10485485] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
An E1B gene-attenuated adenovirus (dl1520) has been proposed to have a selective cytolytic activity in cancer cells with a mutation or deletion in the p53 tumor suppressor gene (p53-null), a defect present in almost half of human hepatocellular carcinomas (HCCs). In this study, the in vitro and in vivo antitumor activity of dl1520 was investigated focusing on two human HCC cell lines, a p53-wild type (p53-wt) cell line and a p53-null cell line. dl1520 was tested for in vitro cytopathic effects and viral replication in the human HCC cell lines Hep3B (p53-null) and HepG2 (p53-wt). The in vivo antitumor effects of dl1520 were investigated in tumors grown s.c. in a severe combined immunodeficient mouse model. In addition, the combination of dl1520 infection with systemic chemotherapy was assessed in these tumor xenografts. At low multiplicities of infection, dl1520 had an apparent p53-dependent in vitro viral growth in HCC cell lines. At higher multiplicities of infection, dl1520 viral replication was independent of the p53 status of the target cells. In vivo, dl1520 significantly retarded the growth of the p53-null Hep3B xenografts, an effect augmented by the addition of cisplatin. However, complete tumor regressions were rare, and most tumors eventually grew progressively. dl1520 had no effect on the in vivo growth of the p53-wt HepG2 cells, with or without cisplatin treatment. The E1B-deleted adenoviral vector dl1520 has an apparent p53-dependent effect in HCC cell lines. However, this effect is lost at higher viral doses and only induces partial tumor regressions without tumor cures in a human HCC xenograft model.
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Affiliation(s)
- C M Vollmer
- Division of Surgical Oncology, University of California Los Angeles, 90095-1782, USA
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Li TK, Chen AY, Yu C, Mao Y, Wang H, Liu LF. Activation of topoisomerase II-mediated excision of chromosomal DNA loops during oxidative stress. Genes Dev 1999; 13:1553-60. [PMID: 10385624 PMCID: PMC316815 DOI: 10.1101/gad.13.12.1553] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.3] [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: 03/02/1999] [Accepted: 05/04/1999] [Indexed: 11/24/2022]
Abstract
Hydrogen peroxide (H2O2), a reactive oxygen species (ROS), is known to induce oxidative stress and apoptosis. U937 cells treated with H2O2 were shown to produce high molecular weight (HMW) DNA fragments approximately 50 to 100 kb in size in <1 min. The formation of these HMW DNA fragments is reversible and shown to be mediated by DNA topoisomerase II (TOP2). Following this initial event, formation of irreversible HMW DNA fragments and nucleosomal ladders occurs. Our results thus demonstrate a potential role of TOP2 in oxidative damage of DNA and apoptotic cell death.
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Affiliation(s)
- T K Li
- Department of Pharmacology, University of Medicine and Dentistry of New Jersey (UMDNJ)-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA
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Chen AY, McKee N. Methods for creating and animating a computer model depicting the structure and function of the sarcoplasmic reticulum calcium ATPase enzyme. J Biocommun 1999; 26:16-22. [PMID: 10216828] [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] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
This paper describes the developmental process used to visualize the calcium ATPase enzyme of the sarcoplasmic reticulum. The steps involved were evaluating scientific information, consulting with scientists, model making, storyboarding, and creating and editing in a computer medium. The product was a computer-generated animation depicting the relationship between the structure and function of the sarcoplasmic reticulum calcium ATPase enzyme.
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Affiliation(s)
- A Y Chen
- Division of Plastic Surgery, University of Toronto
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Abstract
OBJECTIVE To evaluate the cost-effectiveness of several diagnostic tests used in the evaluation of vertigo. STUDY DESIGN Cost-effectiveness analysis, using data from retrospective case review. METHODS Charts and test results were reviewed from 192 outpatients seen in an academic tertiary referral center for evaluation of vertigo. Cost-effectiveness analysis was performed using decision analysis software, data from office and hospital charges, and expert-based estimations of the utility of different test outcomes. Sensitivity analysis was performed using standard algorithms and wide variable ranges. RESULTS We found that audiologic testing, posturography, and electronystagmography were the most cost-effective tests, and that magnetic resonance imaging and blood tests had the lowest cost-effectiveness. The analysis was sensitive to the effects of financial costs of tests but, with a few exceptions, was typically not sensitive to the utility of test outcomes or the distribution of test results. CONCLUSIONS The use of cost-effectiveness analysis, the estimation of utility of test outcomes, and techniques of sensitivity analysis should help guide the clinician's decision making on appropriate testing for patients with vertigo.
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Affiliation(s)
- M G Stewart
- The Bobby R. Alford Department of Otorhinolaryngology and Communicative Sciences, Baylor College of Medicine, Houston, Texas 77030, USA
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Abstract
The rôle of PBL as an innovative approach in medical education has been well documented. There has been an emerging trend of incorporating PBL into the dental curriculum. The potential advantages of PBL as a mode of learning encompass the enhancement of an integrated approach in solving dental-treatment-related problems, the development of critical thinking and problem solving skills and the encouragement of independent life-long learning. PBL was introduced into the dental curriculum as a pilot project in the Faculty of Dentistry, National University of Singapore in summer 1996. An example of a case-based study was illustrated and the learning objectives of the study were highlighted. Initial feedback from students indicated a positive attitude to this mode of learning in terms of cognitive, affective and psychomotor skills. Strategies to enhance learning in the PBL environment include time allocation for self-study, availability of resource materials and use of appropriate assessment methods. Problems that remain to be resolved include the choice of appropriate outcome assessment measures to evaluate the effectiveness of PBL as a mode of learning in undergraduate dental education.
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Affiliation(s)
- L P Lim
- Faculty of Dentistry, National University of Singapore, Kent Ridge, Singapore.
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Abstract
The cause of hearing loss in children is often difficult to identify. We evaluated a cohort of 114 children (47 boys, 67 girls) referred with newly diagnosed hearing loss (non-otitis media) to identify factors predictive of etiology and type of hearing loss. Clinical (history and physical examination), laboratory, and radiographic data were collected. One hundred children (87.7%) had sensorineural hearing loss, and 14 (12.3%) had conductive or mixed hearing loss. The cause of hearing loss was identified in 54 children (48%). Patients with isolated aural atresia (n = 7) or with a known diagnosis of congenital cytomegalovirus infection (n = 21) were excluded from further data analysis. We conducted statistical analysis to identify factors predictive of the cause and type of hearing loss. Clinical factors that aided in identifying a cause included abnormal physical examination findings (p = 0.001) and craniofacial anomalies (p = 0.006). Computed tomography of the temporal bones was the only diagnostic test predictive of cause (p < 0.001). Factors predictive of the type of hearing loss detected (sensorineural vs. conductive or mixed) were abnormal physical examination findings (p = 0.01) and craniofacial anomalies (p = 0.004). An exhaustive laboratory or radiographic workup did not prove beneficial in identifying the etiology of hearing loss in our series.
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Affiliation(s)
- L A Ohlms
- Bobby R. Alford Department of Otorhinolaryngology and Communicative Sciences, Baylor College of Medicine, USA
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Abstract
The outer hair cell is thought to enhance the sensitivity of mammalian hearing. Its lateral wall consists of 3 concentric layers: an outermost plasma membrane, a cortical lattice, and an innermost collection of flattened membranes called the subsurface cisternae. The cytoplasm requires positive pressure for full expression of the outer hair cell's electromotility. Using micropipette aspiration, we investigated the mechanics of the guinea pig's outer hair cell lateral wall at room temperature (22 degrees C) and at the guinea pig's body temperature (39 degrees C). Although there was a 10% decrease in stiffness parameter with an increase from room to body temperature, the difference was not statistically significant; values ranged from 0.45 to 0.65 dyne/cm. With sufficient negative pressure, the cytoplasmic membrane is separated from the rest of the outer hair cell's lateral wall, a process that leads to vesiculation of the plasma membrane. Vesiculation occurs at a lower pressure than at body temperature. Our results demonstrate that the stiffness parameter of the outer hair cell lateral wall at body temperature is similar to that at room temperature. However, the plasma membrane's attachment to the cortical lattice is greatly altered by temperature. The decrease in strength of membrane attachment at body temperature may result from a change in membrane fluidity, making it more easy for membrane attachment sites to break free and permit vesiculation. Whether the tethering of the plasma membrane to the cortical lattice is lost under clinically pathologic conditions deserves future study.
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Affiliation(s)
- A Y Chen
- Bobby R. Alford Department of Otorhinolaryngology and Communicative Sciences, Baylor College of Medicine, Houston, Texas, USA
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Chen AY, Carson JL. Perioperative management of anaemia. Br J Anaesth 1998; 81 Suppl 1:20-4. [PMID: 10318984] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
- A Y Chen
- Division of General Internal Medicine, UMDNJ-Robert Wood Johnson Medical School, New Brunswick, USA
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Abstract
Red blood cell transfusions are used commonly in orthopaedic surgery and cost billions of dollars annually. The goals of transfusion are to reduce mortality and morbidity and improve functional status that result from anemia and inadequate O2 delivery. Risks of infections from transfusion are low and continue to decline, but evidence is growing that red cell transfusions are immunosuppressive and predispose patients to postoperative infections. However, there actually are very little data on when transfusion is indicated. Observational data suggest that transfusion does not reduce mortality in patients with preoperative or postoperative hemoglobin levels 8 g/dL or greater, although no conclusions could be drawn about the effect of transfusion in patients with hemoglobin 8 g/dL or less. Large, well performed randomized clinical trials are needed to establish the efficacy of transfusion. Until better data are available, orthopaedic surgeons will have to rely on clinical judgement in decisions regarding transfusions. Using a higher transfusion threshold in patients with cardiovascular disease is recommended.
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Affiliation(s)
- J L Carson
- Division of General Internal Medicine, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick 08903-0019, USA
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Abstract
OBJECTIVE To assess relationships between voice satisfaction and global quality of life in patients who have been treated for laryngeal cancer. DESIGN Cross-sectional survey study. SETTING Veterans Affairs Medical Center. PATIENTS Eighty patients who had completed treatment for laryngeal cancer with either total laryngectomy (n=17), radiotherapy (n=24), or both (n=39). MAIN OUTCOME MEASURES Subscale scores on a general health status instrument (the Medical Outcomes Study 36-item short-form health survey), and a validated voice-specific functional status instrument (the Voice Handicap Index). RESULTS Self-rated global health did not correlate significantly with emotional, functional, or physical voice handicap, although some subscales on the 36-item short-form health survey correlated with voice handicap scores. Global health status scores did not differ between patients who had undergone laryngectomy with a tracheoesophageal puncture and patients treated with radiotherapy only. Physical voice handicap scores did not differ significantly between those who underwent tracheoesophageal puncture and those who had radiotherapy, but emotional (P=.07) and functional (P=.01) handicap scores were lower in patients treated with radiotherapy. However, there was considerable overlap in voice handicap scores, with many patients who had had tracheoesophageal puncture showing less voice handicap than patients treated with radiotherapy. CONCLUSIONS These data demonstrate that health status is affected by other factors than voice handicap in patients with laryngeal cancer. In addition, there is a large amount of individual variation in voice handicap after treatment. These findings illustrate the need for prospective studies assessing voice handicap and quality of life after treatment for laryngeal cancer.
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Affiliation(s)
- M G Stewart
- Bobby R. Alford Department of Otorhinolaryngology and Communicative Sciences, Baylor College of Medicine, Houston, Tex 77030, USA.
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