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Kuan EC, Wang EW, Adappa ND, Beswick DM, London NR, Su SY, Wang MB, Abuzeid WM, Alexiev B, Alt JA, Antognoni P, Alonso-Basanta M, Batra PS, Bhayani M, Bell D, Bernal-Sprekelsen M, Betz CS, Blay JY, Bleier BS, Bonilla-Velez J, Callejas C, Carrau RL, Casiano RR, Castelnuovo P, Chandra RK, Chatzinakis V, Chen SB, Chiu AG, Choby G, Chowdhury NI, Citardi MJ, Cohen MA, Dagan R, Dalfino G, Dallan I, Dassi CS, de Almeida J, Dei Tos AP, DelGaudio JM, Ebert CS, El-Sayed IH, Eloy JA, Evans JJ, Fang CH, Farrell NF, Ferrari M, Fischbein N, Folbe A, Fokkens WJ, Fox MG, Lund VJ, Gallia GL, Gardner PA, Geltzeiler M, Georgalas C, Getz AE, Govindaraj S, Gray ST, Grayson JW, Gross BA, Grube JG, Guo R, Ha PK, Halderman AA, Hanna EY, Harvey RJ, Hernandez SC, Holtzman AL, Hopkins C, Huang Z, Huang Z, Humphreys IM, Hwang PH, Iloreta AM, Ishii M, Ivan ME, Jafari A, Kennedy DW, Khan M, Kimple AJ, Kingdom TT, Knisely A, Kuo YJ, Lal D, Lamarre ED, Lan MY, Le H, Lechner M, Lee NY, Lee JK, Lee VH, Levine CG, Lin JC, Lin DT, Lobo BC, Locke T, Luong AU, Magliocca KR, Markovic SN, Matnjani G, McKean EL, Meço C, Mendenhall WM, Michel L, Na'ara S, Nicolai P, Nuss DW, Nyquist GG, Oakley GM, Omura K, Orlandi RR, Otori N, Papagiannopoulos P, Patel ZM, Pfister DG, Phan J, Psaltis AJ, Rabinowitz MR, Ramanathan M, Rimmer R, Rosen MR, Sanusi O, Sargi ZB, Schafhausen P, Schlosser RJ, Sedaghat AR, Senior BA, Shrivastava R, Sindwani R, Smith TL, Smith KA, Snyderman CH, Solares CA, Sreenath SB, Stamm A, Stölzel K, Sumer B, Surda P, Tajudeen BA, Thompson LDR, Thorp BD, Tong CCL, Tsang RK, Turner JH, Turri-Zanoni M, Udager AM, van Zele T, VanKoevering K, Welch KC, Wise SK, Witterick IJ, Won TB, Wong SN, Woodworth BA, Wormald PJ, Yao WC, Yeh CF, Zhou B, Palmer JN. International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors. Int Forum Allergy Rhinol 2024; 14:149-608. [PMID: 37658764 DOI: 10.1002/alr.23262] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 08/24/2023] [Indexed: 09/05/2023]
Abstract
BACKGROUND Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field. METHODS In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication. RESULTS The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention. CONCLUSION As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.
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Affiliation(s)
- Edward C Kuan
- Departments of Otolaryngology-Head and Neck Surgery and Neurological Surgery, University of California, Irvine, Orange, California, USA
| | - Eric W Wang
- Department of Otolaryngology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Nithin D Adappa
- Department of Otorhinolaryngology-Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Daniel M Beswick
- Department of Otolaryngology-Head and Neck Surgery, University of California Los Angeles, Los Angeles, California, USA
| | - Nyall R London
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Sinonasal and Skull Base Tumor Program, Surgical Oncology Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Shirley Y Su
- Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Marilene B Wang
- Department of Otolaryngology-Head and Neck Surgery, University of California Los Angeles, Los Angeles, California, USA
| | - Waleed M Abuzeid
- Department of Otolaryngology-Head and Neck Surgery, University of Washington, Seattle, Washington, USA
| | - Borislav Alexiev
- Department of Pathology, Northwestern University Feinberg School of Medicine, Northwestern Memorial Hospital, Chicago, Illinois, USA
| | - Jeremiah A Alt
- Department of Otolaryngology-Head and Neck Surgery, University of Utah, Salt Lake City, Utah, USA
| | - Paolo Antognoni
- Division of Radiation Oncology, University of Insubria, ASST Sette Laghi Hospital, Varese, Italy
| | - Michelle Alonso-Basanta
- Department of Radiation Oncology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Pete S Batra
- Department of Otorhinolaryngology-Head and Neck Surgery, Rush University Medical Center, Chicago, Illinois, USA
| | - Mihir Bhayani
- Department of Otorhinolaryngology-Head and Neck Surgery, Rush University Medical Center, Chicago, Illinois, USA
| | - Diana Bell
- Department of Pathology, City of Hope Comprehensive Cancer Center, Duarte, California, USA
| | - Manuel Bernal-Sprekelsen
- Otorhinolaryngology Department, Surgery and Medical-Surgical Specialties Department, Faculty of Medicine and Health Sciences, Universitat de Barcelona, Barcelona, Spain
| | - Christian S Betz
- Department of Otorhinolaryngology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jean-Yves Blay
- Department of Medical Oncology, Centre Léon Bérard, UNICANCER, Université Claude Bernard Lyon I, Lyon, France
| | - Benjamin S Bleier
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Juliana Bonilla-Velez
- Department of Otolaryngology-Head and Neck Surgery, University of Washington, Seattle, Washington, USA
| | - Claudio Callejas
- Department of Otolaryngology, Pontificia Universidad Católica de Chile, Santiago, Chile
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State University, Columbus, Ohio, USA
| | - Ricardo L Carrau
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State University, Columbus, Ohio, USA
| | - Roy R Casiano
- Department of Otolaryngology-Head and Neck Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Paolo Castelnuovo
- Division of Otorhinolaryngology, Department of Biotechnology and Life Sciences, University of Insubria, ASST Sette Laghi Hospital, Varese, Italy
| | - Rakesh K Chandra
- Department of Otolaryngology-Head and Neck Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | | | - Simon B Chen
- Department of Pathology, Stanford University, Stanford, California, USA
| | - Alexander G Chiu
- Department of Otolaryngology-Head and Neck Surgery, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Garret Choby
- Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Naweed I Chowdhury
- Department of Otolaryngology-Head and Neck Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Martin J Citardi
- Department of Otorhinolaryngology-Head & Neck Surgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Marc A Cohen
- Department of Surgery, Head and Neck Service, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Roi Dagan
- Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, Florida, USA
| | - Gianluca Dalfino
- Division of Otorhinolaryngology, Department of Biotechnology and Life Sciences, University of Insubria, ASST Sette Laghi Hospital, Varese, Italy
| | - Iacopo Dallan
- Department of Otolaryngology-Head and Neck Surgery, Pisa University Hospital, Pisa, Italy
| | | | - John de Almeida
- Department of Otolaryngology-Head and Neck Surgery, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Angelo P Dei Tos
- Section of Pathology, Department of Medicine, University of Padua, Padua, Italy
| | - John M DelGaudio
- Department of Otolaryngology-Head and Neck Surgery, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Charles S Ebert
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Ivan H El-Sayed
- Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, California, USA
| | - Jean Anderson Eloy
- Department of Otolaryngology-Head and Neck Surgery, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - James J Evans
- Department of Neurological Surgery and Otolaryngology-Head and Neck Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Christina H Fang
- Department of Otorhinolaryngology-Head and Neck Surgery, Montefiore Medical Center, The University Hospital for Albert Einstein College of Medicine, Bronx, New York, USA
| | - Nyssa F Farrell
- Department of Otolaryngology-Head and Neck Surgery, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Marco Ferrari
- Section of Otorhinolaryngology-Head and Neck Surgery, Department of Neurosciences, University of Padua, Padua, Italy
| | - Nancy Fischbein
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Adam Folbe
- Department of Otolaryngology-Head and Neck Surgery, Oakland University William Beaumont School of Medicine, Royal Oak, Michigan, USA
| | - Wytske J Fokkens
- Department of Otorhinolaryngology, Amsterdam UMC, Amsterdam, The Netherlands
| | - Meha G Fox
- Department of Otolaryngology-Head and Neck Surgery, Baylor College of Medicine, Houston, Texas, USA
| | | | - Gary L Gallia
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Paul A Gardner
- Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Mathew Geltzeiler
- Department of Otolaryngology-Head and Neck Surgery, Oregon Health and Science University, Portland, Oregon, USA
| | - Christos Georgalas
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Nicosia Medical School, Nicosia, Cyprus
| | - Anne E Getz
- Department of Otolaryngology-Head and Neck Surgery, University of Colorado, Aurora, Colorado, USA
| | - Satish Govindaraj
- Department of Otolaryngology-Head and Neck Surgery, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Stacey T Gray
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - Jessica W Grayson
- Department of Otolaryngology-Head and Neck Surgery, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Bradley A Gross
- Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Jordon G Grube
- Department of Otolaryngology-Head and Neck Surgery, Albany Medical Center, Albany, New York, USA
| | - Ruifeng Guo
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Patrick K Ha
- Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, California, USA
| | - Ashleigh A Halderman
- Department of Otolaryngology-Head and Neck Surgery, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Ehab Y Hanna
- Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Richard J Harvey
- Rhinology and Skull Base Research Group, Applied Medical Research Centre, University of South Wales, Sydney, New South Wales, Australia
| | - Stephen C Hernandez
- Department of Otolaryngology-Head and Neck Surgery, LSU Health Sciences Center, New Orleans, Louisiana, USA
| | - Adam L Holtzman
- Department of Radiation Oncology, Mayo Clinic Florida, Jacksonville, Florida, USA
| | - Claire Hopkins
- Department of Otolaryngology-Head and Neck Surgery, Guys and St Thomas' Hospital, London, UK
| | - Zhigang Huang
- Department of Otolaryngology-Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Key Laboratory of Otolaryngology-Head and Neck Surgery, Ministry of Education, Beijing, China
| | - Zhenxiao Huang
- Department of Otolaryngology-Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Key Laboratory of Otolaryngology-Head and Neck Surgery, Ministry of Education, Beijing, China
| | - Ian M Humphreys
- Department of Otolaryngology-Head and Neck Surgery, University of Washington, Seattle, Washington, USA
| | - Peter H Hwang
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Alfred M Iloreta
- Department of Otolaryngology-Head and Neck Surgery, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Masaru Ishii
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Michael E Ivan
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Aria Jafari
- Department of Otolaryngology-Head and Neck Surgery, University of Washington, Seattle, Washington, USA
| | - David W Kennedy
- Department of Otorhinolaryngology-Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mohemmed Khan
- Department of Otolaryngology-Head and Neck Surgery, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Adam J Kimple
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Todd T Kingdom
- Department of Otolaryngology-Head and Neck Surgery, University of Colorado, Aurora, Colorado, USA
| | - Anna Knisely
- Department of Otolaryngology, Head and Neck Surgery, Swedish Medical Center, Seattle, Washington, USA
| | - Ying-Ju Kuo
- Department of Pathology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Devyani Lal
- Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Eric D Lamarre
- Head and Neck Institute, Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Ming-Ying Lan
- Department of Otorhinolaryngology-Head and Neck Surgery, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Hien Le
- Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Matt Lechner
- UCL Division of Surgery and Interventional Science and UCL Cancer Institute, University College London, London, UK
| | - Nancy Y Lee
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Jivianne K Lee
- Department of Head and Neck Surgery, University of California, Los Angeles David Geffen School of Medicine, Los Angeles, California, USA
| | - Victor H Lee
- Department of Clinical Oncology, School of Clinical Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Corinna G Levine
- Department of Otolaryngology-Head and Neck Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Jin-Ching Lin
- Department of Radiation Oncology, Changhua Christian Hospital, Changhua, Taiwan
| | - Derrick T Lin
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - Brian C Lobo
- Department of Otolaryngology-Head and Neck Surgery, University of Florida, Gainesville, Florida, USA
| | - Tran Locke
- Department of Otolaryngology-Head and Neck Surgery, Baylor College of Medicine, Houston, Texas, USA
| | - Amber U Luong
- Department of Otorhinolaryngology-Head & Neck Surgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Kelly R Magliocca
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Svetomir N Markovic
- Division of Medical Oncology, Department of Oncology, Mayo Clinic, Rochester, Minnesota, USA
| | - Gesa Matnjani
- Department of Radiation Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Erin L McKean
- Department of Otolaryngology-Head and Neck Surgery, University of Michigan, Ann Arbor, Michigan, USA
| | - Cem Meço
- Department of Otorhinolaryngology, Head and Neck Surgery, Ankara University Medical School, Ankara, Turkey
- Department of Otorhinolaryngology Head and Neck Surgery, Salzburg Paracelsus Medical University, Salzburg, Austria
| | - William M Mendenhall
- Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, Florida, USA
| | - Loren Michel
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Shorook Na'ara
- Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, California, USA
| | - Piero Nicolai
- Section of Otorhinolaryngology-Head and Neck Surgery, Department of Neurosciences, University of Padua, Padua, Italy
| | - Daniel W Nuss
- Department of Otolaryngology-Head and Neck Surgery, LSU Health Sciences Center, New Orleans, Louisiana, USA
| | - Gurston G Nyquist
- Department of Otolaryngology-Head and Neck Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Gretchen M Oakley
- Department of Otolaryngology-Head and Neck Surgery, University of Utah, Salt Lake City, Utah, USA
| | - Kazuhiro Omura
- Department of Otorhinolaryngology, The Jikei University School of Medicine, Tokyo, Japan
| | - Richard R Orlandi
- Department of Otolaryngology-Head and Neck Surgery, University of Utah, Salt Lake City, Utah, USA
| | - Nobuyoshi Otori
- Department of Otorhinolaryngology, The Jikei University School of Medicine, Tokyo, Japan
| | - Peter Papagiannopoulos
- Department of Otorhinolaryngology-Head and Neck Surgery, Rush University Medical Center, Chicago, Illinois, USA
| | - Zara M Patel
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - David G Pfister
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Jack Phan
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Alkis J Psaltis
- Department of Otolaryngology-Head and Neck Surgery, Queen Elizabeth Hospital, Adelaide, South Australia, Australia
| | - Mindy R Rabinowitz
- Department of Otolaryngology-Head and Neck Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Murugappan Ramanathan
- Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Ryan Rimmer
- Department of Otolaryngology-Head and Neck Surgery, Yale University, New Haven, Connecticut, USA
| | - Marc R Rosen
- Department of Otolaryngology-Head and Neck Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Olabisi Sanusi
- Department of Neurosurgery, Oregon Health and Science University, Portland, Oregon, USA
| | - Zoukaa B Sargi
- Department of Otolaryngology-Head and Neck Surgery, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Philippe Schafhausen
- Department of Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Rodney J Schlosser
- Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Ahmad R Sedaghat
- Department of Otolaryngology-Head and Neck Surgery, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Brent A Senior
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Raj Shrivastava
- Department of Neurosurgery and Otolaryngology-Head and Neck Surgery, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Raj Sindwani
- Head and Neck Institute, Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Timothy L Smith
- Department of Otolaryngology-Head and Neck Surgery, Oregon Health and Science University, Portland, Oregon, USA
| | - Kristine A Smith
- Department of Otolaryngology-Head and Neck Surgery, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Carl H Snyderman
- Departments of Otolaryngology-Head and Neck Surgery and Neurological Surgery, University of California, Irvine, Orange, California, USA
| | - C Arturo Solares
- Department of Otolaryngology-Head and Neck Surgery, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Satyan B Sreenath
- Department of Otolaryngology-Head and Neck Surgery, Indiana University, Indianapolis, Indiana, USA
| | - Aldo Stamm
- São Paulo ENT Center (COF), Edmundo Vasconcelos Complex, São Paulo, Brazil
| | - Katharina Stölzel
- Department of Otorhinolaryngology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Baran Sumer
- Department of Otolaryngology-Head and Neck Surgery, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Pavol Surda
- Department of Otolaryngology-Head and Neck Surgery, Guys and St Thomas' Hospital, London, UK
| | - Bobby A Tajudeen
- Department of Otorhinolaryngology-Head and Neck Surgery, Rush University Medical Center, Chicago, Illinois, USA
| | | | - Brian D Thorp
- Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Charles C L Tong
- Department of Otorhinolaryngology-Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Raymond K Tsang
- Department of Otolaryngology-Head and Neck Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Justin H Turner
- Department of Otolaryngology-Head and Neck Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Mario Turri-Zanoni
- Division of Otorhinolaryngology, Department of Biotechnology and Life Sciences, University of Insubria, ASST Sette Laghi Hospital, Varese, Italy
| | - Aaron M Udager
- Department of Pathology, Michigan Center for Translational Pathology, Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan, USA
| | - Thibaut van Zele
- Department of Otorhinolaryngology, Ghent University Hospital, Ghent, Belgium
| | - Kyle VanKoevering
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State University, Columbus, Ohio, USA
| | - Kevin C Welch
- Department of Otolaryngology-Head and Neck Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Sarah K Wise
- Department of Otolaryngology-Head and Neck Surgery, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Ian J Witterick
- Department of Otolaryngology-Head and Neck Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Tae-Bin Won
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea
| | - Stephanie N Wong
- Division of Otorhinolaryngology, Department of Surgery, School of Clinical Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Bradford A Woodworth
- Department of Otolaryngology-Head and Neck Surgery, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Peter-John Wormald
- Department of Otolaryngology-Head and Neck Surgery, Queen Elizabeth Hospital, Adelaide, South Australia, Australia
| | - William C Yao
- Department of Otorhinolaryngology-Head & Neck Surgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Chien-Fu Yeh
- Department of Otorhinolaryngology-Head and Neck Surgery, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Bing Zhou
- Department of Otolaryngology-Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Key Laboratory of Otolaryngology-Head and Neck Surgery, Ministry of Education, Beijing, China
| | - James N Palmer
- Department of Otorhinolaryngology-Head and Neck Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Lam TC, Tsang KC, Choi HC, Lee VH, Lam KO, Chiang CL, So TH, Chan WW, Nyaw SF, Lim F, Lau JO, Chik J, Kong FM, Lee AW. Combination atezolizumab, bevacizumab, pemetrexed and carboplatin for metastatic EGFR mutated NSCLC after TKI failure. Lung Cancer 2021; 159:18-26. [PMID: 34303276 DOI: 10.1016/j.lungcan.2021.07.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 06/27/2021] [Accepted: 07/01/2021] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Acquired resistance to TKI is an important unmet need in the management of EGFR mutated lung cancer. Recent clinical trial IMPower150 suggested that combination approach with VEGF inhibitor, check point inhibitor immunotherapy and platinum-based chemotherapy was effective in oncogene driven lung cancer. The current trial examined the efficacy of a modified regimen in an EGFR mutated cohort. METHODS An open-labelled, single arm, phase II study was conducted in patients with EGFR mutated NSCLC who had progressed on at least one EGFR TKI. For those with T790M mutation, radiological progression on osimertinib was required for enrolment. Patients were treated with combination atezolizumab (1200 mg), bevacizumab (7.5 mg/kg), pemetrexed (500 mg/m2) and carboplatin (AUC 5) given once every 3 weeks until progression. RESULTS Forty patients were enrolled. Median age was 62 (range 45-76) years. More than one half (23/40, 57.5%) had progressed on osimertinib. PD-L1 expression was < 1% in 52.5%. Median follow-up time was 17.8 months. ORR was 62.5%. Median PFS was 9.4 months (95% CI: 7.6 - 12.1). One year OS was 72.5% (95% CI: 0.56-0.83). Treatment related grade 3 or above adverse events (AE) occurred in 37.5% (15/40). Immune-related AE occurred in 32.5% (13/40) patients. Quality of life measures of function and symptoms did not change significantly throughout the course of treatments. Post-trial rechallenge with EGFR TKI containing regimen resulted in PFS of 5.8 months (95% CI 3.9-10.0 months). CONCLUSION Combination approach of atezolizumab, bevacizumab, pemetrexed and carboplatin achieved promising efficacy in metastatic EGFR mutated NSCLC after TKI failure. The results were comparable with taxane based regimen of IMPower150 while toxicity profile was improved.
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Affiliation(s)
- T C Lam
- Department of Clinical Oncology, Queen Mary Hospital / Hong Kong University-Shenzhen Hospital, LKS Faculty of Medicine, the University of Hong Kong, Hong Kong, China
| | - K C Tsang
- Department of Clinical Oncology, Queen Mary Hospital / Hong Kong University-Shenzhen Hospital, LKS Faculty of Medicine, the University of Hong Kong, Hong Kong, China
| | - H C Choi
- Department of Clinical Oncology, Queen Mary Hospital / Hong Kong University-Shenzhen Hospital, LKS Faculty of Medicine, the University of Hong Kong, Hong Kong, China
| | - V H Lee
- Department of Clinical Oncology, Queen Mary Hospital / Hong Kong University-Shenzhen Hospital, LKS Faculty of Medicine, the University of Hong Kong, Hong Kong, China
| | - K O Lam
- Department of Clinical Oncology, Queen Mary Hospital / Hong Kong University-Shenzhen Hospital, LKS Faculty of Medicine, the University of Hong Kong, Hong Kong, China
| | - C L Chiang
- Department of Clinical Oncology, Queen Mary Hospital / Hong Kong University-Shenzhen Hospital, LKS Faculty of Medicine, the University of Hong Kong, Hong Kong, China
| | - T H So
- Department of Clinical Oncology, Queen Mary Hospital / Hong Kong University-Shenzhen Hospital, LKS Faculty of Medicine, the University of Hong Kong, Hong Kong, China
| | - W W Chan
- Department of Clinical Oncology, Queen Mary Hospital / Hong Kong University-Shenzhen Hospital, LKS Faculty of Medicine, the University of Hong Kong, Hong Kong, China
| | - S F Nyaw
- Tuen Mun Hospital, Hong Kong, China
| | - F Lim
- Princess Margaret Hospital, Hong Kong, China
| | - J O Lau
- Pamela Youde Nethersole Eastern Hospital, Hong Kong, China
| | - J Chik
- Queen Elizabeth Hospital, Hong Kong, Hong Kong, China
| | - F M Kong
- Department of Clinical Oncology, Queen Mary Hospital / Hong Kong University-Shenzhen Hospital, LKS Faculty of Medicine, the University of Hong Kong, Hong Kong, China
| | - A W Lee
- Department of Clinical Oncology, Queen Mary Hospital / Hong Kong University-Shenzhen Hospital, LKS Faculty of Medicine, the University of Hong Kong, Hong Kong, China
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3
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Du R, Lee VH, Yuan H, Lam KO, Pang HH, Chen Y, Lam EY, Khong PL, Lee AW, Kwong DL, Vardhanabhuti V. Radiomics Model to Predict Early Progression of Nonmetastatic Nasopharyngeal Carcinoma after Intensity Modulation Radiation Therapy: A Multicenter Study. Radiol Artif Intell 2019; 1:e180075. [PMID: 33937796 DOI: 10.1148/ryai.2019180075] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 04/04/2019] [Accepted: 05/07/2019] [Indexed: 12/23/2022]
Abstract
Purpose To examine the prognostic value of a machine learning model trained with pretreatment MRI radiomic features in the assessment of patients with nonmetastatic nasopharyngeal carcinoma (NPC) who are at risk for 3-year disease progression after intensity-modulated radiation therapy and to explain the radiomics features in the model. Materials and Methods A total of 277 patients with nonmetastatic NPC admitted between March 2008 and December 2014 at two imaging centers were retrospectively reviewed. Patients were allocated to a discovery or validation cohort based on where they underwent MRI (discovery cohort, n = 217; validation cohort, n = 60). A total of 525 radiomics features extracted from contrast material-enhanced T1- or T2-weighted MRI studies and five clinical features were subjected to radiomic machine learning modeling to predict 3-year disease progression. Feature selection was performed by analyzing robustness to resampling, reproducibility between observers, and redundancy. Features for the final model were selected with Kaplan-Meier analysis and the log-rank test. A support vector machine was used as the classifier for the model. To interpret the pattern learned from the model, Shapley additive explanations (SHAP) was applied. Results The final model yielded an area under the receiver operating characteristic curve of 0.80 in both the discovery (95% bootstrap confidence interval: 0.80, 0.81) and independent validation (95% bootstrap confidence interval: 0.73, 0.89) cohorts. Analysis with SHAP revealed that tumor shape sphericity, first-order mean absolute deviation, T stage, and overall stage were important factors in 3-year disease progression. Conclusion These results add to the growing evidence of the role of radiomics in the assessment of NPC. By using explanatory techniques, such as SHAP, the complex interaction of features learned by the model may be understood.© RSNA, 2019Supplemental material is available for this article.
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Affiliation(s)
- Richard Du
- Departments of Diagnostic Radiology (R.D., H.Y., P.L.K., V.V.) and Clinical Oncology (V.H.L., K.O.L., A.W.L., D.L.K.) and the School of Public Health (H.H.P.), Li Ka Shing Faculty of Medicine, The University of Hong Kong, Room 406, Block K, Queen Mary Hospital, Pok Fu Lam Road, Hong Kong SAR; Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China (Y.C.); and Department of Electrical and Electronic Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong SAR (E.Y.L.)
| | - Victor H Lee
- Departments of Diagnostic Radiology (R.D., H.Y., P.L.K., V.V.) and Clinical Oncology (V.H.L., K.O.L., A.W.L., D.L.K.) and the School of Public Health (H.H.P.), Li Ka Shing Faculty of Medicine, The University of Hong Kong, Room 406, Block K, Queen Mary Hospital, Pok Fu Lam Road, Hong Kong SAR; Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China (Y.C.); and Department of Electrical and Electronic Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong SAR (E.Y.L.)
| | - Hui Yuan
- Departments of Diagnostic Radiology (R.D., H.Y., P.L.K., V.V.) and Clinical Oncology (V.H.L., K.O.L., A.W.L., D.L.K.) and the School of Public Health (H.H.P.), Li Ka Shing Faculty of Medicine, The University of Hong Kong, Room 406, Block K, Queen Mary Hospital, Pok Fu Lam Road, Hong Kong SAR; Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China (Y.C.); and Department of Electrical and Electronic Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong SAR (E.Y.L.)
| | - Ka-On Lam
- Departments of Diagnostic Radiology (R.D., H.Y., P.L.K., V.V.) and Clinical Oncology (V.H.L., K.O.L., A.W.L., D.L.K.) and the School of Public Health (H.H.P.), Li Ka Shing Faculty of Medicine, The University of Hong Kong, Room 406, Block K, Queen Mary Hospital, Pok Fu Lam Road, Hong Kong SAR; Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China (Y.C.); and Department of Electrical and Electronic Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong SAR (E.Y.L.)
| | - Herbert H Pang
- Departments of Diagnostic Radiology (R.D., H.Y., P.L.K., V.V.) and Clinical Oncology (V.H.L., K.O.L., A.W.L., D.L.K.) and the School of Public Health (H.H.P.), Li Ka Shing Faculty of Medicine, The University of Hong Kong, Room 406, Block K, Queen Mary Hospital, Pok Fu Lam Road, Hong Kong SAR; Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China (Y.C.); and Department of Electrical and Electronic Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong SAR (E.Y.L.)
| | - Yu Chen
- Departments of Diagnostic Radiology (R.D., H.Y., P.L.K., V.V.) and Clinical Oncology (V.H.L., K.O.L., A.W.L., D.L.K.) and the School of Public Health (H.H.P.), Li Ka Shing Faculty of Medicine, The University of Hong Kong, Room 406, Block K, Queen Mary Hospital, Pok Fu Lam Road, Hong Kong SAR; Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China (Y.C.); and Department of Electrical and Electronic Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong SAR (E.Y.L.)
| | - Edmund Y Lam
- Departments of Diagnostic Radiology (R.D., H.Y., P.L.K., V.V.) and Clinical Oncology (V.H.L., K.O.L., A.W.L., D.L.K.) and the School of Public Health (H.H.P.), Li Ka Shing Faculty of Medicine, The University of Hong Kong, Room 406, Block K, Queen Mary Hospital, Pok Fu Lam Road, Hong Kong SAR; Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China (Y.C.); and Department of Electrical and Electronic Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong SAR (E.Y.L.)
| | - Pek-Lan Khong
- Departments of Diagnostic Radiology (R.D., H.Y., P.L.K., V.V.) and Clinical Oncology (V.H.L., K.O.L., A.W.L., D.L.K.) and the School of Public Health (H.H.P.), Li Ka Shing Faculty of Medicine, The University of Hong Kong, Room 406, Block K, Queen Mary Hospital, Pok Fu Lam Road, Hong Kong SAR; Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China (Y.C.); and Department of Electrical and Electronic Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong SAR (E.Y.L.)
| | - Anne W Lee
- Departments of Diagnostic Radiology (R.D., H.Y., P.L.K., V.V.) and Clinical Oncology (V.H.L., K.O.L., A.W.L., D.L.K.) and the School of Public Health (H.H.P.), Li Ka Shing Faculty of Medicine, The University of Hong Kong, Room 406, Block K, Queen Mary Hospital, Pok Fu Lam Road, Hong Kong SAR; Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China (Y.C.); and Department of Electrical and Electronic Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong SAR (E.Y.L.)
| | - Dora L Kwong
- Departments of Diagnostic Radiology (R.D., H.Y., P.L.K., V.V.) and Clinical Oncology (V.H.L., K.O.L., A.W.L., D.L.K.) and the School of Public Health (H.H.P.), Li Ka Shing Faculty of Medicine, The University of Hong Kong, Room 406, Block K, Queen Mary Hospital, Pok Fu Lam Road, Hong Kong SAR; Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China (Y.C.); and Department of Electrical and Electronic Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong SAR (E.Y.L.)
| | - Varut Vardhanabhuti
- Departments of Diagnostic Radiology (R.D., H.Y., P.L.K., V.V.) and Clinical Oncology (V.H.L., K.O.L., A.W.L., D.L.K.) and the School of Public Health (H.H.P.), Li Ka Shing Faculty of Medicine, The University of Hong Kong, Room 406, Block K, Queen Mary Hospital, Pok Fu Lam Road, Hong Kong SAR; Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China (Y.C.); and Department of Electrical and Electronic Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong SAR (E.Y.L.)
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Lee VH, Lam KO, Chang AT, Lam TC, Chiang CL, So TH, Choi CW, Lee AW. Management of Nasopharyngeal Carcinoma: Is Adjuvant Therapy Needed? J Oncol Pract 2018; 14:594-602. [PMID: 30312564 DOI: 10.1200/jop.18.00219] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [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
Nasopharyngeal carcinoma of the undifferentiated histologic subtype is endemic and prevalent in southeast Asia. The dramatic improvement of treatment outcomes and overall prognosis during the past few decades has been attributed to advances in disease screening and diagnosis, diagnostic imaging, radiotherapy techniques, use of combination systemic therapy, and dedicated clinical and biomarker surveillance. The current practice of treating patients with advanced locoregional disease using cisplatin concurrent with conventional fractionated radiotherapy, followed by adjuvant cisplatin and fluorouracil, was established in 1998 when the landmark Intergroup-0099 Study demonstrated a survival benefit with the addition of systemic therapy. There is little doubt regarding the need for concurrent chemotherapy, but there has been uncertainty about the magnitude of the benefit attributed to the adjuvant phase. Furthermore, instead of one-size-fits-all recommendations, it will be ideal if we can tailor adjuvant therapy to high-risk patients only to avoid unnecessary toxicities. In addition, recent evidence suggests that induction chemotherapy before concurrent chemoradiation can achieve better outcomes, especially in distant control, even in the modern era of intensity-modulated radiation therapy. This article provides a comprehensive review of key literature on the current management of locoregionally advanced nasopharyngeal carcinoma and highlights future research directions to unravel these controversies.
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Affiliation(s)
- Victor H. Lee
- The University of Hong Kong, Hong Kong, Special Administrative Region; and The University of Hong Kong-Shenzhen Hospital, Shenzhen, People’s Republic of China
| | - Ka-On Lam
- The University of Hong Kong, Hong Kong, Special Administrative Region; and The University of Hong Kong-Shenzhen Hospital, Shenzhen, People’s Republic of China
| | - Amy T. Chang
- The University of Hong Kong, Hong Kong, Special Administrative Region; and The University of Hong Kong-Shenzhen Hospital, Shenzhen, People’s Republic of China
| | - Tai-Chung Lam
- The University of Hong Kong, Hong Kong, Special Administrative Region; and The University of Hong Kong-Shenzhen Hospital, Shenzhen, People’s Republic of China
| | - Chi-Leung Chiang
- The University of Hong Kong, Hong Kong, Special Administrative Region; and The University of Hong Kong-Shenzhen Hospital, Shenzhen, People’s Republic of China
| | - Tsz-Him So
- The University of Hong Kong, Hong Kong, Special Administrative Region; and The University of Hong Kong-Shenzhen Hospital, Shenzhen, People’s Republic of China
| | - Cheuk-Wai Choi
- The University of Hong Kong, Hong Kong, Special Administrative Region; and The University of Hong Kong-Shenzhen Hospital, Shenzhen, People’s Republic of China
| | - Anne W. Lee
- The University of Hong Kong, Hong Kong, Special Administrative Region; and The University of Hong Kong-Shenzhen Hospital, Shenzhen, People’s Republic of China
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5
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Abstract
Neurocardiology refers to the interplay between the nervous system and the cardiovascular system. Stress-related cardiomyopathy exemplifies the brain-heart connection and occurs in several conditions with acute brain injury that share oversympathetic activation. The brain's influences on the heart can include elevated cardiac markers, arrhythmias, repolarization abnormalities on electrocardiogram, myocardial necrosis, and autonomic dysfunction. The neurogenic stunned myocardium in aneurysmal subarachnoid hemorrhage represents one end of the spectrum, and is associated with an explosive rise in intracranial pressure that results in excess catecholamine state and possibly CBN. A brain-heart link is more known to cardiologists than neurologists. This chapter provides some insight into the pathophysiology of these pathologic neurocardiac states and their most appropriate management relevant to neurologists.
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Affiliation(s)
- N D Osteraas
- Section of Cerebrovascular Diseases, Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - V H Lee
- Section of Cerebrovascular Diseases, Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA.
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6
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Prabhakaran S, Soltanolkotabi M, Honarmand AR, Bernstein RA, Lee VH, Conners JJ, Dehkordi-Vakil F, Shaibani A, Hurley MC, Ansari SA. Perfusion-based selection for endovascular reperfusion therapy in anterior circulation acute ischemic stroke. AJNR Am J Neuroradiol 2014; 35:1303-8. [PMID: 24675999 DOI: 10.3174/ajnr.a3889] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Controversy exists about the role of perfusion imaging in patient selection for endovascular reperfusion therapy in acute ischemic stroke. We hypothesized that perfusion imaging versus noncontrast CT- based selection would be associated with improved functional outcomes at 3 months. MATERIALS AND METHODS We reviewed consecutive patients with anterior circulation strokes treated with endovascular reperfusion therapy within 8 hours and with baseline NIHSS score of ≥8. Baseline clinical data, selection mode (perfusion versus NCCT), angiographic data, complications, and modified Rankin Scale score at 3 months were collected. Using multivariable logistic regression, we assessed whether the mode of selection for endovascular reperfusion therapy (perfusion-based versus NCCT-based) was independently associated with good outcome. RESULTS Two-hundred fourteen patients (mean age, 67.2 years; median NIHSS score, 18; MCA occlusion 74% and ICA occlusion 26%) were included. Perfusion imaging was used in 76 (35.5%) patients (39 CT and 37 MR imaging). Perfusion imaging-selected patients were more likely to have good outcomes compared with NCCT-selected patients (55.3 versus 33.3%, P = .002); perfusion selection by CT was associated with similar outcomes as that by MR imaging (CTP, 56.; MR perfusion, 54.1%; P = .836). In multivariable analysis, CT or MR perfusion imaging selection remained strongly associated with good outcome (adjusted OR, 2.34; 95% CI, 1.22-4.47), independent of baseline severity and reperfusion. CONCLUSIONS In this multicenter study, patients with acute ischemic stroke who underwent perfusion imaging were more than 2-fold more likely to have good outcomes following endovascular reperfusion therapy. Randomized studies should compare perfusion imaging with NCCT imaging for patient selection for endovascular reperfusion therapy.
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Affiliation(s)
| | - M Soltanolkotabi
- Radiology (M.S., A.R.H., A.S., M.C.H., S.A.A.), Northwestern University, Chicago, Illinois
| | - A R Honarmand
- Radiology (M.S., A.R.H., A.S., M.C.H., S.A.A.), Northwestern University, Chicago, Illinois
| | | | - V H Lee
- Department of Neurology (V.H.L., J.J.C.), Rush University Medical Center, Chicago, Illinois
| | - J J Conners
- Department of Neurology (V.H.L., J.J.C.), Rush University Medical Center, Chicago, Illinois
| | - F Dehkordi-Vakil
- Department of Economics and Decision Sciences (F.D.-V.), Western Illinois University, Macomb, Illinois
| | - A Shaibani
- Radiology (M.S., A.R.H., A.S., M.C.H., S.A.A.), Northwestern University, Chicago, Illinois
| | - M C Hurley
- Radiology (M.S., A.R.H., A.S., M.C.H., S.A.A.), Northwestern University, Chicago, Illinois
| | - S A Ansari
- Radiology (M.S., A.R.H., A.S., M.C.H., S.A.A.), Northwestern University, Chicago, Illinois
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7
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Ng SC, Lee VH, Law MW, Liu RK, Ma VW, Tso WK, Leung TW. Patient dosimetry for 90Y selective internal radiation treatment based on 90Y PET imaging. J Appl Clin Med Phys 2013; 14:212-21. [PMID: 24036875 PMCID: PMC5714565 DOI: 10.1120/jacmp.v14i5.4371] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [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: 01/16/2013] [Revised: 03/11/2013] [Accepted: 03/20/2013] [Indexed: 11/23/2022] Open
Abstract
Until recently, the radiation dose to patients undergoing the 90Y selective internal radiation treatment (SIRT) procedure is determined by applying the partition model to 99mTc MAA pretreatment scan. There can be great uncertainty in radiation dose calculated from this approach and we presented a method to compute the 3D dose distributions resulting from 90Y SIRT based on 90Y positron emission tomography (PET) imaging. Five 90Y SIRT treatments were retrospectively analyzed. After 90Y SIRT, patients had 90Y PET/CT imaging within 6 hours of the procedure. To obtain the 3D dose distribution of the patients, their respective 90Y PET images were convolved with a Monte Carlo generated voxel dose kernel. The sensitivity of the PET/CT scanner for 90Y was determined through phantom studies. The 3D dose distributions were then presented in DICOM RT dose format. By applying the linear quadratic model to the dose data, we derived the biologically effective dose and dose equivalent to 2 Gy/fraction delivery, taking into account the spatial and temporal dose rate variations specific for SIRT. Based on this data, we intend to infer tumor control probability and risk of radiation induced liver injury from SIRT by comparison with established dose limits. For the five cases, the mean dose to target ranged from 51.7 ± 28.6 Gy to 163 ± 53.7 Gy. Due to the inhomogeneous nature of the dose distribution, the GTVs were not covered adequately, leading to very low values of tumor control probability. The mean dose to the normal liver ranged from 21.4 ± 30.7 to 36.7 ± 25.9 Gy. According to QUANTEC recommendation, a patient with primary liver cancer and a patient with metastatic liver cancer has more than 5% risk of radiotherapy-induced liver disease (RILD).
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8
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Prabhakaran S, Wells KR, Lee VH, Flaherty CA, Lopes DK. Prevalence and risk factors for aspirin and clopidogrel resistance in cerebrovascular stenting. AJNR Am J Neuroradiol 2007; 29:281-5. [PMID: 17989373 DOI: 10.3174/ajnr.a0818] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The prevalence of antiplatelet drug resistance among patients who undergo cerebrovascular stent placement is unknown. We aimed to assess the feasibility of monitoring antiplatelet drug effects in a single-center cohort undergoing cerebrovascular stent placement. MATERIALS AND METHODS We prospectively collected medical, laboratory, and radiographic data on patients who underwent cerebrovascular stent placement. We used the rapid platelet function assay-aspirin (RPFA-ASA) to calculate aspirin reaction units (ARU) and the P2Y12 assay to calculate P2Y12 reaction units and percentage platelet inhibition. Aspirin resistance was defined as ARU > 550, whereas clopidogrel resistance was defined as percentage platelet inhibition < 40%. RESULTS Among 76 patients, stent indications were the following: wide-neck aneurysm (57, 75.0%), symptomatic intracranial stenosis (12, 15.7%), carotid stenosis (5, 6.6%), and vertebral stenosis (2, 2.6%). For aspirin, the median dosage per week was 1300 mg and median ARU was 410. Among 71 patients on aspirin, 3 patients (4.2%) were resistant; there was a significant inverse correlation between aspirin dose and ARU (r = -0.31, P = .01). Among 55 patients on clopidogrel, the median dosage per week was 525 mg with a mean platelet inhibition of 43.2%. Twenty-eight patients (51.9%) were clopidogrel-resistant. In a multivariable linear regression model, age older than 55 years (b = -16.3, P = .020) and diabetes (b = -26.8, P = .015) were inversely related to percentage platelet inhibition. CONCLUSIONS Using point-of-care tests, we found that aspirin resistance is relatively uncommon, whereas clopidogrel resistance occurred in half of patients undergoing cerebrovascular stent placement. Further studies should focus on ideal doses, timing, and duration of antiplatelet therapy for cerebrovascular stent placement.
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Affiliation(s)
- S Prabhakaran
- Rush University Medical Center, Department of Neurological Sciences, Chicago, IL 60612, USA.
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Wickliffe JK, Lee VH, Smith E, Tandler B, Phillips CJ. Gene expression, cell localization, and evolution of rodent submandibular gland androgen-binding protein. ACTA ACUST UNITED AC 2004; 40:257-60. [PMID: 14566605 DOI: 10.1076/ejom.40.4.257.16692] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [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: 11/03/2022]
Abstract
A small dimeric androgen-binding protein (Abp) secreted by mouse (Mus) submandibular salivary glands has been hypothesized to function in mate-selection. The alpha-subunit (Abpa) evolves rapidly under natural selection. However, cellular site(s) of synthesis, mode of function, and patterns of evolution of this biologically important protein are otherwise unknown. We used a radiolabeled riboprobe and in situ hybridization to mouse (Mus) Abpa mRNA to localize Abpa synthesis to submandibular gland acinar cells. We next used a quantitative fluorescent thermal cycler (real-time PCR) to determine relative expression levels (normalized with a constitutively expressed ribosomal gene [S15/rig; rat insulinoma gene]) in male, female, and sexually immature European striped field mice (Apodemus agrarius). We hypothesized that gender or age-related differences might occur in production of a salivary protein related to sexual selection, but found no significant differences within our sample. Finally, we also used reverse transcription-PCR of mRNAs isolated from submandibular salivary glands to determine the Abpa allele in the striped wood mouse and compare it to published information on the homologue in Mus musculus domesticus.
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Affiliation(s)
- J K Wickliffe
- Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston 79409-3131, USA
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Abstract
This review focuses on epithelial drug transport mechanisms in mucosal drug delivery: the final step of a four-part process. Reference is made to the mucosae lining the oral cavity and the gastrointestinal tract, the two mucosae most often succumbing to the side effects of cytotoxic chemotherapeutic drugs. This review will be devoted to carrier-mediated transport, particularly as it relates to the intestinal dipeptide transporter PepT1. This transporter protein appears to be enriched in tumor epithelial cells, to be rather robust to the cytotoxic effects of chemotherapeutic drugs, and to lend itself to the molecular engineering of drugs that target this transporter in tumor epithelial cells. In contrast to the gastrointestinal tract, much less is known about the type and capacity of drug transport processes in the buccal epithelial cells and about how these processes may be altered in disease state (including cancer) and be manipulated pharmaceutically to optimize drug absorption.
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Affiliation(s)
- V H Lee
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles 90089-9121, USA.
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11
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Abstract
Scientifically, the third millennium begins with a major triumph--the publishing of the human genomic map, which is destined to have a momentous impact on the quality of life in our time. Disease prevention, individualized medicine, and genotyped-based medicine will soon become a reality. Pharmacogenetics, the forerunner of pharmacogenomics, began in the 1950s with a series of observations relating drug response to various genetic factors. It took almost two more decades for scientists to discover that cytochrome p450 2D6 was responsible for the metabolism of many drugs. This landmark discovery helped focus attention on how gene expression could impact the response to drugs. The stage was set for a revolution in therapeutics some 30 years later as the Human Genome Project crossed the finishing line triumphantly. A parallel development in drug delivery that may also benefit from the fruits of the Human Genome Project is the growing acceptance/awareness of drug transporters as a gateway to epithelial drug transport. This presentation addresses an area in need of attention: the possible impact of genetic polymorphism of drug transporters in pharmacokinetics and the challenge it poses in drug delivery.
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Affiliation(s)
- V H Lee
- Department of Pharmaceutical Sciences, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089-9121, USA.
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Melton CM, Zaunbrecher GM, Yoshizaki G, Patiño R, Whisnant S, Rendon A, Lee VH. Expression of connexin 43 mRNA and protein in developing follicles of prepubertal porcine ovaries. Comp Biochem Physiol B Biochem Mol Biol 2001; 130:43-55. [PMID: 11470443 DOI: 10.1016/s1096-4959(01)00403-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [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: 11/27/2022]
Abstract
A major form of cell-cell communication is mediated by gap junctions, aggregations of intercellular channels composed of connexins (Cxs), which are responsible for exchange of low molecular weight (<1200 Da) cytosolic materials. These channels are a growing family of related proteins. This study was designed to determine the ontogeny of connexin 43 (Cx43) during early stages of follicular development in prepubertal porcine ovaries. A partial-length (412 base) cDNA clone was obtained from mature porcine ovaries and determined to have 98% identity with published porcine Cx43. Northern blot analysis demonstrated a 4.3-kb mRNA in total RNA isolated from prepubertal and adult porcine ovaries. In-situ hybridization revealed that Cx43 mRNA was detectable in granulosa cells of primary follicles but undetectable in dormant primordial follicles. The intensity of the signal increased with follicular growth and was greatest in the large antral follicles. Immunohistochemical evaluation indicated that Cx43 protein expression correlated with the presence of Cx43 mRNA. These results indicate that substantial amounts of Cx43 are first expressed in granulosa cells following activation of follicular development and that this expression increases throughout follicular growth and maturation. These findings suggest an association between the enhancement of intercellular gap-junctional communication and onset of follicular growth.
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Affiliation(s)
- C M Melton
- Department of Animal Science and Food Technology, Texas Tech University, Lubbock, TX 79406, USA
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Abstract
This paper discusses the challenges to be met in designing delivery systems that maximize the absorption of peptide and protein drugs from the gastrointestinal and respiratory tracts. The ideal delivery system for either route of administration is one that will release its contents only at a favorable region of absorption, where the delivery system attaches by virtue of specific interaction with surface determinants unique to that region and where the delivery system travels at a rate independent of the transitory constraints inherent of the route of administration. Such a delivery system, which is as yet unavailable, will benefit not only peptide and protein drugs, but other poorly absorbed drugs.
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Affiliation(s)
- U B Kompella
- Department of Pharmaceutical Sciences, John Stauffer Pharmaceutical Sciences Center, University of Southern California School of Pharmacy, Los Angeles, CA, USA
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Donahue LM, Coates PW, Lee VH, Ippensen DC, Arze SE, Poduslo SE. The cardiac sodium channel mRNA is expressed in the developing and adult rat and human brain. Brain Res 2000; 887:335-43. [PMID: 11134623 DOI: 10.1016/s0006-8993(00)03033-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [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: 11/24/2022]
Abstract
Expression of the rat (RH-I/SkM2) and human (hH1/SCN5A) tetrodotoxin-resistant (TTX-R), voltage-sensitive sodium channels is thought to be specific to cardiac tissue. We detected RH-I/SkM2 mRNA in newborn rat brain using both RNase protection assay analysis and in situ hybridization and in adult rat brain using RNase protection assay analysis. This expression was observed primarily in developing limbic structures of the cerebrum and diencephalon, and in the medulla of the brain stem. Using RT-PCR analysis, we detected hH1/SCN5A mRNA in both fetal and adult human brain. Interestingly, mutations in the human cardiac sodium channel are known to lead to cardiac abnormalities, which result in arrhythmias and frequently in sudden cardiac death. If these mutant channels were also expressed in limbic regions of the brain, alterations in channel function could have drastic effects on the brain's signaling ability, possibly promoting seizure activity.
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Affiliation(s)
- L M Donahue
- Cascade Biologics, Inc., 4475 SW Scholls Ferry Road, Portland, OR 97225, USA.
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Chang X, Patiño R, Yoshizaki G, Thomas P, Lee VH. Hormonal regulation and cellular distribution of connexin 32.2 and connexin 32.7 RNAs in the ovary of Atlantic croaker. Gen Comp Endocrinol 2000; 120:146-56. [PMID: 11078626 DOI: 10.1006/gcen.2000.7549] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The in vitro effects of human chorionic gonadotropin (hCG) on ovarian connexin (Cx) 32.2 and 32.7 RNA levels and ovarian follicle maturation were assessed, and the cellular distribution of Cx transcripts in the ovary was determined. hCG caused a concentration-dependent induction of Cx32.2 RNA, which peaked coincidentally with the appearance of morphological indices of oocyte maturational competence (OMC). Cx32.2 RNA levels declined thereafter in all treatment groups, although this decline was not accompanied by the onset of germinal vesicle breakdown (GVBD) at the lowest hCG concentration used. The levels of Cx32.7 RNA initially declined and subsequently increased to preincubation values after hCG treatment, but these changes were not dependent on hCG concentration. In a separate experiment, the decline in Cx32.7 RNA occurred in the presence or absence of hCG and was prevented by low (physiological) concentrations of estradiol-17beta (E2) or by protein kinase C (PKC) inhibitor, but was enhanced in the presence of high E2 concentrations or of PKC activator. These changes in Cx32. 7 RNA abundance were not associated with any indices of oocyte maturation. In situ hybridization of tissue sections showed the presence of Cx32.2 and Cx32.7 RNA in somatic cells of the ovarian follicle but not in oocytes. Cx32.2 RNA seemed to be present in granulosa and thecal cells, but the assay resolution was insufficient to reliably determine the distribution of Cx32.7 transcript by somatic cell type. In view of earlier findings that Cx32.2-based (but not Cx32.7-based) connexons can form functional homotypic channels, these results indicate that Cx32.2 gene expression in granulosa cells is sufficient for the formation of homologous gap junctions (GJ). Northern blot of RNA extracts from ovulated eggs, which are free of follicle cells, showed the presence of relatively low levels of both Cx RNAs. Thus, it is possible that Cx32.2 is present in oocytes and that it participates in heterologous (homotypic) GJ formation between the oocyte and the granulosa cells. In conclusion, Cx32.2 RNA levels in somatic cells of the ovarian follicle correlated positively with morphological indices of OMC acquisition, but subsequently declined during GVBD. These changes in Cx32.2 RNA may function in the regulation of GJ contacts during follicular maturation.
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Affiliation(s)
- X Chang
- Texas Cooperative Fish & Wildlife Research Unit, Texas Tech University, Lubbock, Texas 79409-2120, USA
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16
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Abstract
Carrier-mediated drug transport is relatively unexplored in comparison with passive transcellular and paracellular drug transport. Yet, there is a host of transporter proteins that can be targeted for improving epithelial drug absorption. Generally, these are transport mechanisms for amino acids, dipeptides, monosaccharides, monocarboxylic acids, organic cations, phosphates, nucleosides, and water-soluble vitamins. Among them, the dipeptide transporter mechanism has received the most attention. Dipeptide transporters are H(+)-coupled, energy-dependent transporters that are known to play an essential role in the oral absorption of beta-lactam antibiotics, angiotensin-converting enzyme (ACE) inhibitors, renin inhibitors, and an anti-tumor drug, bestatin. Moreover, several investigators have demonstrated the utility of the dipeptide transporter as a platform for improving the oral bioavailability of drugs such as zidovudine and acyclovir through dipeptide prodrug derivatization. Thus far, at least four proton-coupled peptide transporters have been cloned. The first one cloned was PepT1 from the rabbit small intestine. The focus of this presentation will be structure-function, intracellular trafficking, and regulation of PepT1. Disease, dietary, and possible excipient influences on PepT1 function will also be discussed.
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Affiliation(s)
- V H Lee
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, PSC 708, Los Angeles, CA 90089-9121, USA.
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17
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Abstract
Progress in research on initiation of folliculogenesis has progressed slowly because of a lack of markers for early folliculogenesis. The rabbit zona pellucida protein (ZP1) is synthesized in follicles during early stages of folliculogenesis. In order to establish ZP1 as a marker for initiation of folliculogenesis, in situ hybridization was used to localize ZP1 mRNA in immature follicles. ZP1 mRNA was first detected in oocytes of some but not all primordial follicles. The primordial follicles expressing ZP1 mRNA were located at the cortico-medullary junction, indicating that they were newly activated follicles. ZP1 mRNA accumulated in oocytes of intermediate, primary, and secondary follicles. In contrast, ZP1 mRNA was first detectable in granulosa cells of intermediate follicles and is present in cuboidal granulosa cells of primary and early secondary follicles, but was undetectable in granulosa cells of more mature follicles. These data demonstrate that 1) ZP1 mRNA is expressed in both oocytes and granulosa cells, 2) ZP1 mRNA is initially expressed in oocytes of activated follicles, and 3) ZP1 mRNA is transiently expressed in granulosa cells during early stages of folliculogenesis. Therefore, rabbit ZP1 is a molecular marker that can be used in future studies to measure initiation of folliculogenesis.
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Affiliation(s)
- V H Lee
- Department of Cell Biology & Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA.
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18
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Abstract
The RUSH transcription factors 1alpha and 1beta bind to the Rabbit Uteroglobin promoter and are members of the SWI/SNF complex that facilitates transcription by remodeling chromatin (Helicase). To characterize gonadal expression of RUSH, a cRNA probe that recognizes both isoforms was used for in situ hybridization studies. We found RUSH mRNA to be abundant in Sertoli cells from embryonic, neonatal, prepubertal, and pubertal rabbit testes. In adults, RUSH mRNA was detected in tubules with preleptotene spermatocytes and mature spermatids lining the lumen. However, RUSH was undetectable in tubules that contained leptotene spermatocytes and that lacked mature spermatids. In females, RUSH was expressed in presumptive granulosa cells of embryonic and neonatal ovaries before follicle organization. Abundant RUSH mRNA was detected in granulosa and theca cells surrounding preantral follicles of prepubertal and adult ovaries. Expression of RUSH remained high in granulosa cells of antral follicles in mature ovaries but was negligible in late-stage atretic follicles and in corpora lutea. Western blot analysis confirmed the RUSH-1alpha isoform predominated in both testicular and ovarian tissues. The expression pattern of RUSH indicates transcriptional activity in Sertoli cells and during multiple stages of differentiating granulosa cells, especially those of primordial follicles, which heretofore were considered to be dormant.
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Affiliation(s)
- A Rendon
- Department of Cell Biology & Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA
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19
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Abstract
PURPOSE To identify the growth conditions that would favor the development of a functional primary culture of pigmented rabbit corneal epithelial cells on a permeable support comparable to the intact tissue in bioelectric properties. METHODS Rabbit corneal epithelial cells were isolated and cultured on precoated fibronectin/collagen/laminin permeable filters. Cells were grown at an air-interface with supplemented DMEM/F12 medium. Immunofluorescence and electron microscopy techniques, respectively, were used to confirm cornea-specific marker and morphological features. Permeability of the cell layers to model polar compounds was evaluated using 14C-mannitol, fluorescein isothiocyanate (FITC) and fluorescein isothiocyanate-dextran of 4,000 molecular weight (FD4). RESULTS We found that culturing the epithelial cells at an air-interface (AIC) was a critical factor in the formation of tight cell layer and that omitting fetal bovine serum and keeping the concentration of epidermal growth factor at 1 ng/ml were equally important. Phenotypically, the AIC cell layers were found to express cornea-specific 64 kD keratin. Compared with cells cultured under the liquid-covered (LCC) condition, those cultured under AIC exhibited a significantly higher peak transepithelial electrical resistance (TEER) of up to 5 kOhm x cm2, a higher potential difference (PD) of up to 26 mV, and an estimated short-circuit current (Ieq) of 5 microA/cm2 after 7-8 days of culture. These values were comparable to those in the excised cornea. Consistent with the TEER, the AIC cell layers were 4-40 times less permeable to paracellular markers than their LCC counterpart. CONCLUSIONS The AIC model merits further characterization of drug transport mechanisms as well as drug, formulation, physiological, and pathological factors influencing corneal epithelial drug transport.
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Affiliation(s)
- J E Chang
- Department of Pharmaceutical Sciences, Schools of Pharmacy and Medicine, University of Southern California, Los Angeles 90089, USA
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20
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Abstract
We determined net fluid secretion rate across the pigmented rabbit conjunctiva in the presence and absence of pharmacological agents known to affect active Cl- secretion and Na+ absorption. Fluid flow across a freshly excised pigmented rabbit conjunctiva mounted between two Lucite half chambers was measured by a pair of capacitance probes in an enclosed cabinet maintained at 37 degrees C and a relative humidity of 70%. Fluid transport was also measured in the presence of compounds known to affect active Cl- secretion (cAMP, UTP, and ouabain), Na+ absorption (D-glucose), or under the Cl--free condition on both sides of the tissue. Net fluid secretion rate across the pigmented rabbit conjunctiva in the serosal-to-mucosal direction at baseline was 4.3+/-0.2 microl/hr/cm2 (mean +/- s.e.m.). Net fluid secretion rate was increased approximately two-fold by mucosally applied 1 mM 8-Br cAMP (8.4+/-0.4 microl/hr/cm2) and 10 microM UTP (9.8+/-0.6 microl/hr/cm2), but was abolished by either serosally applied 0.5 mM ouabain (0.3+/-0.1 microl/hr/cm2) or under the Cl--free conditions (0.06+/-0.04 microl/hr/cm2). Mucosal addition of 20 mM D-glucose decreased net fluid secretion rate to 1.0+/-0.5 microl/hr/cm2. In conclusion, the pigmented rabbit conjunctiva appears to secrete fluid secondary to active Cl- secretion. This net fluid secretion is subject to modulation by changes in active Cl- secretion rate and in mucosal fluid composition such as glucose concentration.
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Affiliation(s)
- M H Shiue
- Department of Pharmaceutical Sciences, University of Southern California, Los Angeles 90033, USA
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21
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Abstract
The transport of model proteins, ranging from 12,300 to 150,000 Da, across tight rat alveolar epithelial cell monolayers (> 2000omegacm2) grown on polycarbonate filters, was studied. Model proteins were 14C-cytochrome c, 14C-ovalbumin, granulocyte-colony stimulating factor (G-CSF), 14C-bovine serum albumin (BSA), 125I-transferrin, and 14C-immunoglobulin G. Cytochrome c was extensively metabolized, as indicated by < 10% of the dose being translocated in intact form. This contrasts with 20-80% for the other model proteins studied. The flux of cytochrome c and G-CSF was symmetric in the apical-to-basolateral (ab) and basolateral-to-apical (ba) directions. By contrast, the flux of intact ovalbumin, BSA, transferrin and immunoglobulin G showed asymmetry, with the ab flux being higher by 2-5 times. There was no relationship between ab or ba fluxes and the molecular weights of these four model proteins. Since some of the proteins were translocated at much greater rates than are consistent with restricted diffusion or pinocytosis, receptor-mediated or adsorptive transcytosis may be involved.
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Affiliation(s)
- Y Matsukawa
- Department of Pharmaceutical Sciences, Will Rogers Institute Pulmonary Research Center, University of Southern California, Los Angeles 90033, USA
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22
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Abstract
PURPOSE To determine the role of P-glycoprotein (P-gp) in propranolol transport in cultured rabbit conjunctival epithelial cell layers (RCEC). METHODS The localization of P-gp in the cultured RCEC as well as in the excised conjunctiva was determined by immunofluorescence technique. The role of P-gp in transepithelial transport and uptake of propranolol in conjunctival epithelial cells cultured on Transwell filters was evaluated in the presence and absence of P-gp competing substrates, an anti-P-gp monoclonal antibody (4E3 mAb), or a metabolic inhibitor, 2,4-dinitrophenol (2,4-DNP). RESULTS Immunofluorescence studies revealed positive staining in the apical membrane of cultured RCEC and in the apical surface of the superficial cell layers in the excised conjunctiva, but not the basolateral membrane of cultured RCEC. Transport of propranolol showed preference in the basolateral-to-apical direction. The net secretory flux was saturable with a Km of 71.5 +/- 24.0 nM and a Jmax of 1.45 +/- 0.17 pmol/cm2/hr. Cyclosporin A, progesterone, rhodamine 123, verapamil, 4E3 mAb and 2,4-DNP all increased apical 50 nM propranolol uptake by 43% to 66%. On the other hand, neither beta-blockers (atenolol, metoprolol, and alprenolol) nor organic cation transporter substrates (tetraethylammonium (TEA) and guanidine), affected apical 50 nM propranolol uptake. CONCLUSIONS The energy-dependent efflux pump P-gp appears to be predominantly located on the apical plasma membrane of the conjunctival epithelium. It may play an important role in restricting the conjunctival absorption of some lipophilic drugs.
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Affiliation(s)
- J J Yang
- Department of Pharmaceutical Sciences, University of Southern California, Los Angeles 90089-9121, USA
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23
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Ueda H, Horibe Y, Kim KJ, Lee VH. Functional characterization of organic cation drug transport in the pigmented rabbit conjunctiva. Invest Ophthalmol Vis Sci 2000; 41:870-6. [PMID: 10711706] [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: 02/15/2023] Open
Abstract
PURPOSE To characterize carrier-mediated organic cation drug transport in the rabbit conjunctiva. METHODS The transport of [14C]guanidine, the model substrate, in the excised pigmented rabbit conjunctiva was evaluated in the modified Ussing chamber. Tetraethylammonium (TEA) transport also was investigated to determine substrate specificity. RESULTS The apparent permeability coefficient for guanidine and TEA in the mucosal-to-serosal (ms) direction was 5.4 and 49.6 times greater than that in the serosal-to-mucosal (sm) direction, respectively. Guanidine transport in the ms (but not sm) direction revealed temperature and concentration dependency over 0.02 to 10 mM with an apparent Michaelis-Menten constant of 3.1 mM and a maximal flux of 11.4 nmol/(cm2 x h). Net guanidine transport measured at 0.1 mM across the conjunctiva was decreased by 71% or 82%, respectively, on the addition of 1 microM valinomycin (a K+ ionophore) in both bathing fluids or in a high K+ buffer in the mucosal fluid. Interestingly, net guanidine transport was reduced, rather than enhanced, by 63% upon acidifying the mucosal bathing fluid. By contrast, net guanidine transport was not affected by the serosal presence of 0.5 mM ouabain (a Na+, K+-ATPase inhibitor), by the mucosal and serosal presence of 0.1 microM monensin (a Na+ ionophore) or 0.3 microM carbonyl cyanide p-(trifluoromethoxy)phenyl-hydrazone (FCCP, a H+ ionophore). Guanidine transport in the ms direction was polyspecific, as indicated by the 48% to 82% inhibition by structurally diverse amines. In particular, guanidine ms transport was inhibited by the antiglaucoma drugs dipivefrine (72%), brimonidine (70%), and carbachol (78%). CONCLUSIONS A carrier-mediated organic cation transport process appears to exist in the conjunctiva, mediating the absorption of organic amines, including certain amine-type ophthalmic drugs. This process may be driven by an inside-negative apical membrane potential difference.
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Affiliation(s)
- H Ueda
- Department of Pharmaceutical Sciences, University of Southern California, Los Angeles 90089-9121, USA
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24
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Yang JJ, Ueda H, Kim K, Lee VH. Meeting future challenges in topical ocular drug delivery: development of an air-interfaced primary culture of rabbit conjunctival epithelial cells on a permeable support for drug transport studies. J Control Release 2000; 65:1-11. [PMID: 10699264 DOI: 10.1016/s0168-3659(99)00226-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [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: 11/22/2022]
Abstract
The purpose of this study was to develop and characterize a functional air-interfaced primary culture of rabbit conjunctival epithelial cells grown on a permeable support for drug transport studies. Conjunctival epithelial cells from the pigmented rabbit were isolated, seeded at 1.2 x 10(6) cells cm(-2) on permeable Transwell filters, and cultured at the air interface using a modified PC-1 medium. Conjunctival epithelial cell layers showed a transepithelial resistance of 1.1+/-0.1 kOmega cm(2), a potential difference of 17.0+/-0.5 mV, and an equivalent short-circuit current (I(eq)) of 16.1+/-0.4 microA cm(-2). The I(eq) was reduced by 35% using 0.01 mM bumetanide, 66% using 0.1 mM ouabain, 46% using 2 mM barium chloride (all three in the basolateral fluid), and 63% using 0.3 mM NPAA in the apical fluid, consistent with active Cl(-)-secretion across the conjunctival epithelial barrier. Amiloride-sensitive Na(+) channels were absent. The permeability of the cell layers to polar solutes decreased with increased solute size, and the calculated equivalent pore size was about 8.0 nm. The Papp of beta-blockers varied with lipophilicity in a sigmoidal fashion. Uridine transport showed temperature sensitivity and directionality, favoring transport in the apical-to-basolateral direction. Apical L-carnosine uptake was reduced by 46% in the absence of an inwardly directed proton gradient, and lowering the temperature to 4 degrees C abolished direction-dependent L-carnosine uptake. Furthermore, uptake was inhibited by 73% using apical 10 mM glycyl sarcosine (a dipeptide transporter substrate) and by 60% using 1 mM L-valacyclovir (a dipeptide prodrug). In conclusion, a functional air-interfaced primary culture of rabbit conjunctival epithelial cell layers was established. This air-interfaced primary culture model may be useful for studying passive and active transport processes for ion and solute translocation in the mammalian conjunctival epithelial barrier in a defined experimental setting.
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Affiliation(s)
- J J Yang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, PSC 704, Los Angeles, CA, USA
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25
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Lee VH, Chu C, Mahlin ED, Basu SK, Ann DK, Bolger MB, Haworth IS, Yeung AK, Wu SK, Hamm-Alvarez S, Okamoto CT. Biopharmaceutics of transmucosal peptide and protein drug administration: role of transport mechanisms with a focus on the involvement of PepT1. J Control Release 1999; 62:129-40. [PMID: 10518644 DOI: 10.1016/s0168-3659(99)00030-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [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: 11/26/2022]
Abstract
Non-invasive delivery of peptide and protein drugs will soon become a reality. This is due partly to a better understanding of the endogenous transport mechanisms, including paracellular transport, endocytosis, and carrier-mediated transport of mucosal routes of peptide and protein drug administration. This paper focuses on work related to the elucidation of structure-function, intracellular trafficking, and regulation of the intestinal dipeptide transporter, PepT1.
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Affiliation(s)
- V H Lee
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90033, USA.
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26
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Hosoya K, Ueda H, Kim KJ, Lee VH. Nucleotide stimulation of Cl(-) secretion in the pigmented rabbit conjunctiva. J Pharmacol Exp Ther 1999; 291:53-9. [PMID: 10490886] [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] Open
Abstract
We evaluated the role of extracellular UTP and other nucleotides in the regulation of active ion transport across the pigmented rabbit conjunctiva. When added to the mucosal side of the conjunctiva, UTP (0.01-1000 microM), increased the short-circuit current by up to 14. 6 +/- 2.1 microA/cm(2). The half-maximal concentration was 11.4 +/- 2.3 microM. The serosal absence of Cl(-), serosal presence of 10 microM bumetanide, and mucosal presence of 0.3 mM N-phenylanthranilic acid significantly reduced the change in the short-circuit current (DeltaIsc) induced by 10 microM UTP by 78, 77, and 42%, respectively. Mucosal 10 microM UTP significantly increased (36)Cl flux in the serosal-to-mucosal direction by 0.17 microEq/cm(2)/h, while not affecting mucosal-to-serosal (36)Cl flux. By contrast, (22)Na transport in either direction was unaffected. The rank order of DeltaIsc elicited by adenosine and nucleotides was consistent with the predominant involvement of P2Y purinergic receptors in the UTP effect on conjunctival ion transport. Moreover, the DeltaIsc elicited by UTP was inhibited by 0.05 and 1 mM suramin (a P2-purinergic receptor antagonist), resulting in a rightward shift of the half-maximal concentration to 106.7 +/- 1.3 microM. In conclusion, the primary effect of UTP on ion transport in the pigmented rabbit conjunctiva is stimulation of Cl(-) secretion, possibly at the P2Y(2) and/or the P2Y(4) receptor on the mucosal side of the tissue. Because of the coupling of fluid flow with Cl(-) secretion, UTP or its analogs may be considered for stimulating transconjunctival fluid flow in the dry-eye state.
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Affiliation(s)
- K Hosoya
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
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27
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Abstract
PURPOSE To characterize organic cation (OC) transport in primary cultured rabbit alveolar epithelial cell monolayers, using [14C]-guanidine as a model substrate. METHODS Type II alveolar epithelial cells from the rabbit lung were isolated by elastase digestion and cultured on permeable filters precoated with fibronectin and collagen. Uptake and transport studies of [14C]-guanidine were conducted in cell monolayers of 5 to 6 days in culture. RESULTS The cultured alveolar epithelial cell monolayers exhibited the characteristics of a tight barrier. [14C]-Guanidine uptake was temperature dependent, saturable, and inhibited by OC compounds such as amiloride, cimetidine, clonidine, procainamide, propranolol, tetraethylammonium, and verapamil. Apical guanidine uptake (Km = 129 +/- 41 microM, Vmax = 718 +/- 72 pmol/mg protein/5 min) was kinetically different from basolateral uptake (Km = 580 +/- 125 microM, Vmax = 1,600 +/- 160 pmol/mg protein/5 min). [14C]-Guanidine transport across the alveolar epithelial cell monolayer in the apical to basolateral direction revealed a permeability coefficient (Papp) of (7.3 +/- 0.4) x 10(-7) cm/sec, about seven times higher than that for the paracellular marker [14C]-mannitol. CONCLUSIONS Our findings are consistent with the existence of carrier-mediated OC transport in cultured rabbit alveolar epithelial cells.
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Affiliation(s)
- J Shen
- Department of Pharmaceutical Sciences, University of Southern California, Los Angeles 90033, USA
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28
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Abstract
We reported that the nucleotide sequence of a cDNA generated from rabbit placental poly(A)(+) RNA using porcine preprorelaxin primers was identical to SQ10, a product of squamous differentiated tracheal epithelial cells. However, these results did not confirm that SQ10 was the biologically active rabbit relaxin that had been isolated previously yet not sequenced. In this study, a 7-kDa protein isolated from rabbit placentas exhibited relaxin bioactivity and cross-reacted with a porcine relaxin antiserum. A partial amino acid sequence of this protein revealed a sequence identical to that of SQ10. Although the amino acid sequence of the putative relaxin receptor-binding domain found in the B chain of relaxin was modified in SQ10 from CGRDYVR to CRNDFVR, the placental protein was bioactive. These results suggest that SQ10 is the rabbit relaxin. In situ hybridization, using an SQ10 riboprobe, indicated radiolabeling in the syncytiotrophoblast cells of the rabbit placenta. The pattern of labeling corresponded with the immunohistochemical staining for relaxin observed with use of a porcine relaxin antiserum. These results indicate that the syncytiotrophoblast cells are a site of synthesis for SQ10 and that the immunostaining is not solely the result of sequestering SQ10 through receptor-mediated endocytosis. A potential role for relaxin in implantation is discussed.
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Affiliation(s)
- P A Fields
- Department of Structural & Cellular Biology, University of South Alabama College of Medicine, Mobile, Alabama 36688, USA.
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29
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Abstract
Repressive chromatin must be remodeled to allow for transcriptional activation of genes in eukaryotic cells. Factors that alter chromatin structure to permit access of transcriptional activators, RNA polymerase II and the polymerase-associated general transcription factors to nucleosomal promoter sequences are as highly conserved as the basic mechanism of transcription. One group of promoter restructuring factors that perturbs chromatin in an ATP-dependent manner includes NURF, CHRAC, ACF, the SWI/SNF complex, and SWI/SNF-related proteins. Each member of this group contains a subunit homologous to the DNA-dependent ATPase; however, their individual mechanisms of action are unique. The small amount of SWI/SNF complex (100-200 copies/cell), its affiliation with a select number of inducible genes, and its interaction with the glucocorticoid and estrogen receptors, suggests the SWI/SNF complex might be preferentially targeted to active promoters. The SWI/SNF-related family of RUSH proteins which includes RUSH-1alpha and beta, hHLTF, HIP116, Zbu1, P113, and the transcription factor RUSH-1alpha isolog has been implicated as a highly conserved DNA binding site-specific ATPase.
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Affiliation(s)
- J H Devine
- Cell Biology and Biochemistry, Texas Technical University Health Sciences Center, Lubbock 79430, USA
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30
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Elbert KJ, Schäfer UF, Schäfers HJ, Kim KJ, Lee VH, Lehr CM. Monolayers of human alveolar epithelial cells in primary culture for pulmonary absorption and transport studies. Pharm Res 1999; 16:601-8. [PMID: 10349999 DOI: 10.1023/a:1018887501927] [Citation(s) in RCA: 133] [Impact Index Per Article: 5.3] [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: 11/12/2022]
Abstract
PURPOSE To develop a cell culture model of human alveolar epithelial cells in primary culture for the in vitro study of pulmonary absorption and transport. METHODS Type II pneumocytes isolated from normal human distal lung tissue by enzyme treatment and subsequent purification were plated on fibronectin/collagen coated polyester filter inserts, and cultured using a low-serum growth medium. Characterization of the cell culture was achieved by bioelectric measurements, cell-specific lectin binding, immunohistochemical detection of cell junctions, and by assessment of transepithelial transport of dextrans of varying molecular weights. RESULTS In culture, the isolated cells spread into confluent monolayers, exhibiting peak transepithelial resistance of 2,180 +/- 62 ohms x cm2 and potential difference of 13.5 +/- 1.0 mV (n = 30-48), and developing tight junctions as well as desmosomes. As assessed by lectin-binding, the cell monolayers consisted of mainly type I cells with some interspersed type II cells, thus well mimicking the situation in vivo. The permeability of hydrophilic macromolecular FITC-dextrans across the cell monolayer was found to be inversely related to their molecular size, with Papp values ranging from 1.7 to 0.2 x 10(-8) cm/sec. CONCLUSIONS A primary cell culture model of human alveolar epithelial cells has been established, which appears to be a valuable in vitro model for pulmonary drug delivery and transport studies.
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Affiliation(s)
- K J Elbert
- Department of Biopharmaceutics and Pharmaceutical Technology, Saarland University, Saarbrücken, Germany
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31
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Chung YB, Han K, Nishiura A, Lee VH. Ocular absorption of Pz-peptide and its effect on the ocular and systemic pharmacokinetics of topically applied drugs in the rabbit. Pharm Res 1998; 15:1882-7. [PMID: 9892473 DOI: 10.1023/a:1011914324720] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [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: 11/12/2022]
Abstract
PURPOSE To determine the corneal and conjunctival penetration of 4-phenylazobenzyloxycarbonyl-L-Pro-L-Leu-Gly-L-Pro-D-Arg (Pz-peptide) and to evaluate its effect on the corneal and conjunctival penetration of hydrophilic solutes as well as on the ocular and systemic absorption of topically applied atenolol and propranolol in the rabbit. The hydrophilic solutes were mannitol, fluorescein, FITC-dextran 4,000, and FITC-dextran 10,000. METHODS Drug penetration across the rabbit cornea and conjunctiva was evaluated using the modified Ussing chamber. Ocular and systemic absorption of topically applied atenolol and propranolol was evaluated by analyzing the drug concentration in various anterior segment tissues at 45 min and in the blood over 240 min, respectively, following topical instillation of 25 microl of 20 mM atenolol or propranolol solution to the rabbit eye. RESULTS The conjunctiva was 29 times more permeable than the cornea to 3 mM Pz-peptide. Conjunctival Pz-peptide transport was 1.7 times more extensive in the mucosal-to-serosal than in the opposite direction, whereas corneal Pz-peptide transport showed no directionality. The apparent permeability coefficient of Pz-peptide across the cornea and the conjunctiva increased over the 1-5 mM range, suggesting that Pz-peptide enhanced its own transport across both epithelial tissues. The cornea appeared to be more sensitive than the conjunctiva to the penetration enhancement effect of Pz-peptide. Thus, whereas Pz-peptide elevated the corneal transport of mannitol, fluorescein, and FD4 by 50%, 57%, and 106%, respectively, it did not affect the conjunctival transport of mannitol and fluorescein, while enhancing FD4 transport by only 46%. Moreover, while Pz-peptide enhanced the ocular absorption of topically applied hydrophilic atenolol, it did not affect the ocular absorption of lipophilic propranolol. Interestingly, Pz-peptide did not affect the systemic absorption of either beta adrenergic antagonist. CONCLUSIONS Pz-peptide appears to facilitate its own penetration across the cornea and the conjunctiva. Pz-peptide appears to increase the ocular absorption of topically applied hydrophilic but not lipophilic drugs, while not affecting the systemic absorption of either type of drugs.
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Affiliation(s)
- Y B Chung
- Chungbuk National University, College of Pharmacy, Cheongju, Korea
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Basu SK, Haworth IS, Bolger MB, Lee VH. Proton-driven dipeptide uptake in primary cultured rabbit conjunctival epithelial cells. Invest Ophthalmol Vis Sci 1998; 39:2365-73. [PMID: 9804145] [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: 02/09/2023] Open
Abstract
PURPOSE To characterize proton-driven carrier-mediated dipeptide uptake in primary cultured conjunctival epithelial cells of the pigmented rabbit using beta-alanyl-L-histidine (L-carnosine) as a model dipeptide substrate. METHODS Uptake of tritiated L-carnosine was monitored using conjunctival epithelial cells on days 6 through 8 in culture on a filter support. The structural features of dileucine stereoisomers and cephalexin contributing to interaction with the dipeptide transporter were evaluated by computer modeling and inhibition of tritiated L-carnosine uptake. RESULTS Uptake of L-carnosine by primary cultured conjunctival epithelial cells in the presence of an inwardly directed proton gradient showed directional asymmetry (favoring apical uptake by a factor of five), temperature dependence, and saturability correlated with substrate concentration, with a Michaelis-Menten constant (Km) of 0.3 +/- 0.03 mM and a maximum uptake rate (Vmax) of 22.0 +/- 1.0 picomoles per milligram protein per minute. L-Carnosine uptake was optimal at pH 6.0 and was reduced by 60% and 35%, respectively, by 50 microM p-trifluoromethoxyphenylhydrazone (a proton ionophore) and by acid preloading with 50 mM NH4Cl. The constituent amino acids did not inhibit L-carnosine uptake. L-Carnosine uptake was inhibited, however, from 50% to 80% by other dipeptides and structurally similar drugs such as bestatin, beta-lactam antibiotics, and angiotensin-converting enzyme inhibitors. The LL, LD, or DL forms of the dipeptide Leu-Leu inhibited tritiated L-carnosine uptake by approximately 60%, 40%, and 70%, respectively. By contrast, the DD form did not inhibit uptake. Results from computer modeling suggest that an appropriate dipeptide N-terminal to C-terminal distance and a favorable orientation of the side chains may be important for substrate interaction with the conjunctival dipeptide transporter. CONCLUSIONS Uptake of the dipeptide L-carnosine in primary cultured pigmented rabbit conjunctival epithelial cells is probably mediated by a proton-driven dipeptide transporter. This transporter may be used for optimizing the uptake of structurally similar peptidomimetic drugs.
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Affiliation(s)
- S K Basu
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles 90033, USA
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Bolger MB, Haworth IS, Yeung AK, Ann D, von Grafenstein H, Hamm-Alvarez S, Okamoto CT, Kim KJ, Basu SK, Wu S, Lee VH. Structure, function, and molecular modeling approaches to the study of the intestinal dipeptide transporter PepT1. J Pharm Sci 1998; 87:1286-91. [PMID: 9811478 DOI: 10.1021/js980090u] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.7] [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: 01/13/2023]
Abstract
The proton-coupled intestinal dipeptide transporter, PepT1, has 707 amino acids, 12 putative transmembrane domains (TMD), and is of importance in the transport of nutritional di- and tripeptides and structurally related drugs, such as penicillins and cephalosporins. By using a combination of molecular modeling and site-directed mutagenesis, we have identified several key amino acid residues that effect catalytic transport properties of PepT1. Our molecular model of the transporter was examined by dividing it into four sections, parallel to the membrane, starting from the extracellular side. The molecular model revealed a putative transport channel and the approximate locations of several aromatic and charged amino acid residues that were selected as targets for mutagenesis. Wild type or mutagenized human PepT1 cDNA was transfected into human embryonic kidney (HEK293) cells, and the uptake of tritiated glycylsarcosine [3H]-(Gly-Sar) was measured. Michaelis-Menton analysis of the wild-type and mutated transporters revealed the following results for site-directed mutagenesis. Mutation of Tyr-12 or Arg-282 into alanine has only a very modest effect on Gly-Sar uptake. By contrast, mutation of Trp-294 or Glu-595 into alanine reduced Gly-Sar uptake by 80 and 95%, respectively, and mutation of Tyr-167 reduced Gly-Sar uptake to the level of mock-transfected cells. In addition, preliminary data from fluorescence microscopy following the expression of N-terminal-GFP-labeled PepT1Y167A in HEK cells indicates that the Y167A mutation was properly inserted into the plasma membrane but has a greatly reduced Vmax.
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Affiliation(s)
- M B Bolger
- Departments of Pharmaceutical Sciences, Molecular Pharmacology and Toxicology, and Ophthalmology, Schools of Pharmacy, Medicine, and Engineering, University of Southern California, Los Angeles, California 90033, USA
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Yeung AK, Basu SK, Wu SK, Chu C, Okamoto CT, Hamm-Alvarez SF, von Grafenstein H, Shen WC, Kim KJ, Bolger MB, Haworth IS, Ann DK, Lee VH. Molecular identification of a role for tyrosine 167 in the function of the human intestinal proton- coupled dipeptide transporter (hPepT1). Biochem Biophys Res Commun 1998; 250:103-7. [PMID: 9735340 DOI: 10.1006/bbrc.1998.9283] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [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
hPepT1 is a proton-coupled peptide transporter that mediates the absorption of di- and tripeptides. Here we show that tyrosine 167 (Y167) in transmembrane domain 5 (TMD5) of this 12-transmembrane spanning protein contributes to its transport function. We identified this particular amino acid by a computer model of the arrangement of the TMDs of hPepT1 and investigated its role by site-directed mutagenesis and dipeptide uptake studies. [3H]Gly-sar uptake in cells transiently transfected with Y167A-hPepT1 was abolished completely, even though the level of Y167A-hPepT1 expression by Western blot analysis and cell surface expression by immunofluorescence microscopy was similar to those of the wild type. Therefore, mutation affected transport function, but apparently not the steady-state protein level or trafficking of the transporter to the plasma membrane. Moreover, mutation of Y167 into phenylalanine, serine, or histidine all abolished gly-sar uptake in transfected HEK 293 cells. Taken together, these findings suggest that Y167 plays an essential role in hPepT1 function, perhaps due to the unique chemistry of its phenolic side chain.
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Affiliation(s)
- A K Yeung
- Schools of Pharmacy, Medicine, and Engineering, University of Southern California, Los Angeles, California, 90033, USA
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Carpenter AM, Lukyanenko YO, Lee VH, Hutson JC. FSH does not directly influence testicular macrophages. J Androl 1998; 19:420-7. [PMID: 9733144] [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: 02/08/2023]
Abstract
We have previously demonstrated that conditioned medium from testicular macrophages stimulates testosterone production by Leydig cells. It was also reported that conditioned medium from macrophages treated with follicle-stimulating hormone (FSH) had an even greater amount of Leydig cell-stimulating activity than medium from untreated macrophages, indicating that this factor is under the regulation of FSH. However, most other laboratories have been unable to reproduce this effect of FSH. We have recently purified and partially characterized the stimulatory factor from macrophage-conditioned medium that stimulates Leydig cells. The purpose of the present investigation was to reinvestigate the effect of FSH by determining whether it regulates the production of this purified factor and by determining whether macrophages have mRNA for the FSH receptor. Testicular macrophages were isolated from adult rats and incubated 24 hours with human recombinant FSH (20 units/ml), ovine FSH (200 ng/ml), fetal bovine serum (2%), or dibutyryl cyclic adenosine monophosphate (1 mM). The macrophage-derived factor (MDF) was then purified from conditioned medium of the various treatment groups and added to Leydig cells. The concentration of testosterone in the Leydig cell medium was then measured after 16 hours. It was found that serum significantly stimulated production of the MDF. However, FSH had no effect on production of the MDF in the presence or absence of serum. Dibutyryl cyclic adenosine monophosphate exerted a slight inhibitory effect on production of the macrophage-derived factor. Most importantly, testicular macrophages did not express detectable levels of FSH receptor mRNA, either in vivo or in vitro, when evaluated using either in situ hybridization or northern analysis, under identical conditions that clearly demonstrated FSH receptor mRNA in Sertoli cells. We conclude that testicular macrophages are not a direct target for FSH.
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Affiliation(s)
- A M Carpenter
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock 79430, USA
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Abstract
PURPOSE To determine the functional presence ofa H+/peptide cotransport process in rabbit tracheal epithelial cell layers cultured at an air-interface and its contribution to transepithelial dipeptide transport. METHODS Rabbit tracheocytes were isolated, plated on Transwells, and cultured at an air-interface. After 5 or 6 days in culture, uptake and transepithelial transport of carnosine were examined. RESULTS Carnosine uptake by tracheocytes was pH-dependent and was saturable with a Michaelis-Menten constant of 170 microM. Moreover, carnosine uptake was inhibited 94% by Gly-L-Phe, 28% by beta-Ala-Gly, but not at all by Gly-D-Phe or by the amino acids beta-Ala and L-His. Unexpectedly. transepithelial carnosine transport at pH 7.4 (i.e., in the absence of a transepithelial pH gradient) was similar in both the apical-to-basolateral (ab) and basolateral-to-apical (ba) directions. Lowering the apical fluid pH to 6.5 reduced ab transport 1.6 times without affecting ba transport, consistent with predominantly paracellular diffusion of carnosine under an electrochemical potential gradient. CONCLUSIONS The kinetic behavior of carnosine uptake into cultured tracheal epithelial cell layers is characteristic of a H+-coupled dipeptide transport process known to exist in the small intestine and the kidney. Such a process does not appear to be rate-limiting in the transport of carnosine across the tracheal epithelial barrier.
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Affiliation(s)
- F Yamashita
- Department of Pharmaceutical Sciences, University of Southern California, Los Angeles 90033, USA
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Horibe Y, Hosoya K, Kim KJ, Lee VH. Carrier-mediated transport of monocarboxylate drugs in the pigmented rabbit conjunctiva. Invest Ophthalmol Vis Sci 1998; 39:1436-43. [PMID: 9660492] [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: 02/08/2023] Open
Abstract
PURPOSE To determine whether an Na+-dependent monocarboxylate transport process exists on the mucosal side of the pigmented rabbit conjunctiva and to evaluate how it may contribute to the absorption of ophthalmic monocarboxylate drugs. METHODS L-lactate was used as a model substrate. The excised pigmented rabbit conjunctiva was mounted in a modified Ussing chamber for the measurement of short-circuit current (Isc) and 14C-L.-lactate transport. RESULTS When added to the mucosal side at 37 degrees C and at pH 7.4, applications of as much as 40 mM L- and D-lactate increased Isc in a saturable manner. By contrast, no change in Isc was observed at 4 degrees C or under the mucosal Na+-free condition. 14C-L-lactate transport in the mucosal-to-serosal (m-s) direction at 0.01 mM revealed directionality, temperature dependency, Na+ dependency, and ouabain sensitivity, but not pH dependency. L-lactate transport in the m-s direction consisted of a saturable Na+-dependent process by the transcellular pathway and a nonsaturable process by the paracellular pathway. For the saturable process, the apparent Michaelis-Menten constant was 1.9 mM, the maximum flux was 8.9 nanomoles/cm2 per hour, and the apparent Na+ :L-lactate coupling ratio was 2:1. 14C-L-lactate transport in the m-s direction was significantly inhibited (46% to 83%) by the mucosal presence of various monocarboxylate compounds, but not by dicarboxylate compounds, zwitterionic compound, D-glucose, amino acids, and peptidomimetic antibiotics. Monocarboxylate nonsteroidal anti-inflammatory drugs and the antibacterial fluoroquinolones inhibited 14C-L-lactate transport by 40% to 85%, whereas prostaglandins and cromolyn had no effect. CONCLUSIONS An Na+-dependent monocarboxylate transport process that may be used by non-steroidal anti-inflammatory and fluoroquinolone antibacterial drugs for transport appears to be present on the mucosal side of the pigmented rabbit conjunctiva. A possible physiologic role for the Na+-dependent monocarboxylate transport process may be to salvage tear lactate.
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Affiliation(s)
- Y Horibe
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles 90033, USA
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Saha P, Yang JJ, Lee VH. Existence of a p-glycoprotein drug efflux pump in cultured rabbit conjunctival epithelial cells. Invest Ophthalmol Vis Sci 1998; 39:1221-6. [PMID: 9620082] [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: 02/07/2023] Open
Abstract
PURPOSE To determine whether a p-glycoprotein (P-gp) drug efflux pump exists in cultured rabbit conjunctival epithelial cells (RCEs) to restrict the absorption of cyclosporin A (CSA) and other lipophilic drugs such as verapamil and dexamethasone. METHODS The anti-P-gp monoclonal antibody (mAb) C219 was used in western blot analysis to reveal the presence of P-gp in freshly isolated and cultured RCEs. Bidirectional transport of tritiated CSA, verapamil, and dexamethasone (0.5 or 5.0 microM) across cultured RCEs was evaluated in the absence and presence of P-gp inhibitors and an external mAb to P-gp (4E3). RESULTS Western blot analysis of lysates of freshly isolated and cultured RCEs with C219 mAb revealed a 170-kDa membrane protein band. At 0.5 microM CSA, the basal-to-apical (ba) apparent permeability coefficient (P(app) that is, efflux) was 9.3 times higher than that in the apical-to-basal direction (that is, influx). At 5 microM, this ratio was halved. Net CSA secretion was blocked completely at 4 degrees C. Verapamil (100 microM), progesterone (100 microM) and 4E3 mAb (5 microg/ml) increased CSA influx three times, while reducing efflux by 50% to 70%. Verapamil and progesterone inhibited CSA efflux in a concentration-dependent manner. In all cases, net secretory CSA flux was markedly reduced. The P(app) for verapamil (0.5 microM) and dexamethasone (0.5 microM) in the ba direction was 3.4 and 1.6 times, respectively, which was higher than that in the opposite direction. The 4E3 mAb reduced net verapamil secretion by 65%. CONCLUSIONS There may exist a P-gp-mediated drug efflux pump on the apical aspect of the rabbit conjunctiva to restrict the absorption of cyclosporin A and other lipophilic drugs.
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Affiliation(s)
- P Saha
- Department of Pharmaceutical Sciences, University of Southern California, Los Angeles 90033, USA
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Lee VH, Lee AB, Phillips EB, Roberts JK, Weitlauf HM. Spatio-temporal pattern for expression of galectin-3 in the murine utero-placental complex: evidence for differential regulation. Biol Reprod 1998; 58:1277-82. [PMID: 9603264 DOI: 10.1095/biolreprod58.5.1277] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [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: 11/01/2022] Open
Abstract
In mice, immunoreactive galectin-3 protein has previously been localized in uterine epithelial cells adjacent to implanting blastocysts as well as in the decidualized endometrium of implantation sites, uterine natural killer cells, and several types of placental trophoblast cells. Because galectin-3 is a soluble extracellular molecule, protein localization by immunohistochemical methods does not demonstrate its cellular origin. Therefore, the present study was undertaken to determine precisely which cell types in the utero-placental complex express galectin-3 mRNA. In situ hybridization results demonstrated that galectin-3 mRNA was expressed throughout the utero-placental complex in all cell types previously shown to contain immunoreactive protein, including uterine epithelium, decidualized endometrium, uterine natural killer cells, and placental trophoblasts. These results indicate that galectin-3 protein is not synthesized in a restricted cell type and translocated through the extracellular spaces to other tissue compartments. Furthermore, Northern blot analysis of total RNA prepared from separated fetal and maternal components of utero-placental complexes demonstrated different patterns of expression for galectin-3 mRNA in the uterus and placenta. Relative levels of galectin-3 mRNA peak at midgestation in the implantation site and during the second half of gestation remain elevated in the placenta but decline in the uterus. Separate mechanisms for regulating expression of galectin-3 on opposite sides of the feto-maternal interface are indicated.
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Affiliation(s)
- V H Lee
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock 79430, USA.
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Hosoya KI, Horibe Y, Kim KJ, Lee VH. Carrier-mediated transport of NG-nitro-L-arginine, a nitric oxide synthase inhibitor, in the pigmented rabbit conjunctiva. J Pharmacol Exp Ther 1998; 285:223-7. [PMID: 9536014] [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: 02/07/2023] Open
Abstract
In this study, the transport mechanism of NG-nitro-L-arginine (L-NA), a nitric oxide synthase inhibitor that may be useful for alleviating intraocular inflammation, was characterized in the pigmented rabbit conjunctiva. L-NA, when applied to the mucosal side of the conjunctiva, led to dose-dependent increases in the short-circuit current (Isc) at 37 degrees C but not at 4 degrees C or under the Na+-free condition. Serosally added 1 mM L-NA did not elicit any change in the Isc. Mucosally added 1 mM L-NA elicited a net absorptive Na+ flux of 0.09 microEq/(cm2.hr), comparable with the Isc change. L-NA transport at 0.1 mM in the mucosal-to-serosal (ms) direction was 22 times greater than that in the serosal-to-mucosal direction. There was a good correlation between the ms flux of L-NA and the Isc changes elicited by L-NA under the same experimental conditions. L-NA transport was saturable, with a Km of 0.35 mM and a maximal flux of 290 pmol/(cm2.min). Hill analysis of L-NA flux observed at 0.1 mM L-NA in response to varying Na+ concentrations in the mucosal bathing fluid yielded a Hill coefficient of 0.98, suggesting a 1:1 coupling between Na+ and L-NA. Moreover, ms 3H-L-NA transport was inhibited by basic amino acids (L-Arg and L-Lys) and a neutral amino acid (L-Leu), but not by an acidic amino acid (L-Glu) and the D-stereoisomer of L-NA. In the case of L-Arg, inhibition was competitive with a Ki of 0.034 mM. Taken together, the above findings are consistent with the involvement of the L-Arg transport system B0,+ in the conjunctival transport of L-NA.
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Affiliation(s)
- K I Hosoya
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90033, USA
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Abstract
The purpose of the present study was to investigate whether active Cl- secretion in the pigmented rabbit conjunctiva was subject to cAMP, Ca2+ and protein kinase C (PKC) modulation. The excised pigmented rabbit conjunctivas were mounted in the modified Ussing-type chambers for measurement of unidirectional 36Cl fluxes under the open-circuit condition and of the short-circuit current (Isc), potential difference, and transconjunctival electrical resistance. The results indicate that Cl- secretion across the conjunctiva was abolished by mucosal application of 1 mM N-phenylanthranilic acid and was reduced by 40% by serosal application of 10 microM bumetanide. Net Cl- flux was stimulated by 133% by 1 mM 8-Br cAMP, 107% by 10 microM A23187, and 87% by 1 microM phorbol 12-myristate-13-acetate (PMA), suggesting that cAMP, Ca2+, and PKC all modulated active Cl- secretion, respectively. There existed a linear correlation between measured changes in net Cl- flux and observed changes in Isc (r2=0.99). The serial treatment of the conjunctiva with (a) 1 mM 8-Br cAMP and 10 microM A23187 and (b) 10 microM A23187 and 1 microM PMA resulted in sequence-independent, additive stimulation of Isc. In the case of 1 mM 8-Br cAMP and 1 microM PMA, additive stimulation of Isc was observed only when 1 mM 8-Br cAMP was added prior to 1 microM PMA. These results suggest that a given pharmacological agent may affect more than one channel type and that there might be a possible connection among the channels at the signal transduction level. In summary, Cl- appears to enter the pigmented rabbit conjunctiva from the serosal fluid via Na+-(K+)-2Cl- cotransport process and exit to the mucosal fluid via channels, resulting in active Cl- secretion. Active Cl- secretion in the pigmented rabbit conjunctiva appears to be modulated by cAMP, Ca2+, and PKC.
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Affiliation(s)
- M H Shiue
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90033, USA
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Hosoya K, Horibe Y, Kim KJ, Lee VH. Nucleoside transport mechanisms in the pigmented rabbit conjunctiva. Invest Ophthalmol Vis Sci 1998; 39:372-7. [PMID: 9477996] [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: 02/06/2023] Open
Abstract
PURPOSE To elucidate the mechanisms of nucleoside transport in the pigmented rabbit conjunctiva using [3H]uridine as the substrate. METHODS Excised pigmented rabbit conjunctiva was mounted in a modified Ussing chamber for measurement of short-circuit current (Isc) and [3H]uridine transport. RESULTS [3H]Uridine transport in the mucosal-to-serosal direction at 10 microM exhibited directionality, temperature dependency, and phlorizin sensitivity. Uridine transport appeared to be mediated via saturable Na(+)-dependent and nitrobenzylthioinosine-insensitive Na(+)-independent processes. The corresponding Michaelis-Menten constants (K(m)) were 1.9 microM and 200 microM, and the maximal uridine fluxes (Jmax) were 29.3 and 46.7 pmol/cm2 per minute. When added to the mucosal side containing 141 mM Na+, uridine increased the Isc in a dose-dependent manner from 0.005 mM to 1.0 mM at 37 degrees C. The K(m) value was 7.6 microM, and the maximal increase in Isc was 0.71 microA/cm2. Hill analysis of uridine transport at 10 microM in the presence of varying Na+ concentrations in the mucosal bathing fluid yielded a Hill coefficient of 1.1, suggesting a 1:1 coupling between Na+ and uridine. Na(+)-dependent uridine transport was inhibited by 10 microM adenosine, guanosine, and inosine, but not by thymidine, suggesting that the transport process may be mainly selective for purine nucleosides. Moreover, 2'-deoxyuridine, 5-iodo-2'-deoxyuridine, and 5-(2-bromovinyl)-2'-deoxyuridine were potent inhibitors of Na(+)-dependent uridine transport. CONCLUSIONS Na(+)-dependent and Na(+)-independent nucleoside transport processes appeared to be localized on the mucosal aspect of the pigmented rabbit conjunctiva. One or more Na(+)-coupled uridine cotransport processes exhibited a 1:1 stoichiometry and an apparent preference toward purine nucleosides.
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Affiliation(s)
- K Hosoya
- Department of Pharmaceutical Sciences, University of Southern California, Los Angeles, USA
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Affiliation(s)
- S K Basu
- Department of Pharmaceutical Sciences, University of Southern California, Los Angeles 90033, USA
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Lee VH. AAPS focus groups: a promising mechanism for scientific interchange. Pharm Dev Technol 1998; 3:ix-x. [PMID: 9532593 DOI: 10.3109/10837459809028620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Sun L, Basu SK, Kim KJ, Lee VH. Arginine vasopressin transport and metabolism in the pigmented rabbit conjunctiva. Eur J Pharm Sci 1998; 6:47-52. [PMID: 16256707 DOI: 10.1016/s0928-0987(97)00067-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/1997] [Accepted: 05/29/1997] [Indexed: 10/18/2022]
Abstract
The purpose of this study was to evaluate the transepithelial transport and metabolism of arginine vasopressin (AVP) in the pigmented rabbit conjunctiva, both in the absence and presence of protease inhibitors. The apparent permeability coefficient, P(app), for 3H-AVP was determined in the modified Ussing chamber, and AVP metabolites were monitored by reversed phase HPLC using a C18 column. At 50 nM donor 3H-AVP, the P(app) in the mucosal-to-serosal (ms) direction was about five times higher than that in the opposite direction. Excess (0.1 mM) AVP decreased the P(app) for labelled AVP in the mucosal-to-serosal (ms) direction by about 50%. However, intact AVP transport showed neither concentration nor direction dependence. HPLC analysis revealed two subspecies of 3H-AVP in the receiver fluid and virtually no degradation products in the donor fluid following 3 h flux experiments. 3H-AVP transported in the ms direction underwent extensive hydrolysis (73%), which was decreased by 33% with mucosal application of 2 mM camostat mesylate (an aminopeptidase inhibitor) or by 27% with 0.5 mM leupeptin (a serine protease inhibitor). By contrast, 3H-AVP transported in the serosal-to-mucosal (sm) direction resulted in only 37% hydrolysis, and mucosal application of either inhibitor did not significantly affect the P(app) for intact AVP. These data suggest that intact AVP transport in the conjunctiva may be mediated mostly by passive diffusion and enzymatic degradation of AVP may be mediated by proteolytic enzymes present on the mucosal side of the conjunctiva.
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Affiliation(s)
- L Sun
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90033, USA
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Abstract
A procedure for synthesizing NB1-palmitoyl insulin for incorporation into liposomes for targeting to hepatocytes was developed. The amino group of the first amino acid phenylalanine on the B chain (B1) of insulin was selected for conjugation with palmitic acid in anticipation that its binding to the insulin receptor would be preserved. Two other free amino groups present in insulin, the first amino acid glycine on the A chain (A1) and the 29th amino acid lysine on the B chain (B29), were first protected with a t-butoxycarbonyloxy (t-Boc) group to yield NA1, B29-di-(t-Boc) insulin. The identity of this di-(t-Boc) insulin was confirmed by amino acid analysis as well as by enzyme hydrolysis coupled with matrix-assisted laser-desorption time of flight mass spectrometry (MALDI-TOF MS). NA1,B29-Di-(t-Boc) insulin was then reacted with the N-hydroxysuccinimide ester of palmitic acid, followed by deblocking the t-Boc groups, to yield NB1-palmitoyl insulin, the structure of which was further confirmed by MALDI-TOF MS analysis. NB1-palmitoyl insulin was found to interact with the insulin receptor on fat cells, thereby catalyzing the conversion of [14C]glucose into lipids, at reduced efficiency (30-40%).
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Affiliation(s)
- Y J Tsai
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles 90033, USA
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Abstract
PURPOSE To obtain kinetic evidence for the existence of a Na(+)-coupled glucose co-transport process on the mucosal (tear) side of the pigmented rabbit conjunctiva. METHODS The excised pigmented rabbit conjunctiva was mounted in the modified Ussing chamber for measurement of 22Na and 3H-3-O-methyl-D-glucose (3-O-MG) fluxes. RESULTS In the presence of 5 mM glucose, the conjunctival tissue showed net Na+ absorption in the mucosal-to-serosal direction at an approximate rate of 0.15 microEq/cm2/h. This net Na+ absorption was abolished by serosally added 0.5 mM ouabain, but not affected by mucosally added 0.1 mM or 1 mM amiloride. There was a 40-60% reduction in net Na+ absorption under the glucose-free condition or in the mucosal presence of 0.5 mM phlorizin. Moreover, serosally added ouabain and mucosally added phlorizin (both at 0.5 mM) significantly decreased the 3-O-MG permeability coefficient in the mucosal-to-serosal direction by about 70%, whereas mucosally instilled 0.1-1.0 mM amiloride was without any effect. Three-O-MG absorption in the mucosal-to-serosal direction appeared to be coupled with Na+ transport with a 1:1 stoichiometry. In addition, this process exhibited temperature dependency, saturability, and directionality. CONCLUSION Our findings are consistent with Na(+)-glucose cotransport as being one of the mechanisms for mucosal Na+ entry into the epithelial cells of the pigmented rabbit conjunctiva.
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Affiliation(s)
- Y Horibe
- Department of Pharmaceutical Sciences, University of Southern California, Los Angeles, USA
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Abstract
The objective of this study was to characterize Na(+)-coupled L-arginine (L-Arg) transport in the pigmented rabbit conjunctiva. The excised pigmented rabbit conjunctiva was mounted in the modified Ussing chamber for measurement of short-circuit current (Isc), 3H-L-arginine (3H-L-Arg) flux, and 22Na flux. L-Arg when added to the mucosal side led to 0.32-2.65 microA cm-2 increases in the Isc at 37 degrees C, but not at 4 degrees C or in a Na(+)-free solution. L-Arg at 1 mM stimulated net Na+ absorption by 0.12 microEq cm-2 h-1. The evidence for carrier-mediated transport of L-Arg includes: (1) temperature dependence and saturability over 0.01-10 mM, (2) Na+ dependence and ouabain sensitivity, (3) 84 +/- 2% reduction in the apparent permeability coefficient (Papp) of 3H-L-Arg in the presence of excess unlabeled L-Arg (1 mM), and (4) 16-fold difference in L-Arg transport (at 0.1 mM) between the mucosal-to-serosal and the serosal-to-mucosal direction. Moreover, L-Arg transport was inhibited by basic amino acids, large neutral amino acids, and nitric oxide synthase inhibitors, but not by acidic and small neutral amino acids. Kinetic analysis revealed the possible existence of both high and low affinity processes for L-Arg transport. A half maximal concentration (Km) and maximal L-Arg flux (Jmax) values of the low and high affinity processes were 5.90 and 0.07 mM, and 1,248 and 111 pmol cm-2 min-1, respectively. Hill analysis of L-Arg transport at 0.1 mM in the presence of varying Na+ concentrations in the mucosal bathing fluid yielded a Hill coefficient of 0.93, suggesting a 1:1 coupling between Na+ and L-Arg. In conclusion, Na(+)-coupled transport process(es) for L-Arg in accordance with a 1:1 stoichiometry appear to be present on the mucosal side of the pigmented rabbit conjunctiva. The pattern of inhibition by basic and large neutral amino acids and Na+ dependency are suggestive of system B0,(+)-mediated L-Arg transport.
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Affiliation(s)
- K Hosoya
- Department of Pharmaceutical Sciences, University of Southern California, Los Angeles 90033, USA
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Horibe Y, Hosoya K, Kim KJ, Ogiso T, Lee VH. Polar solute transport across the pigmented rabbit conjunctiva: size dependence and the influence of 8-bromo cyclic adenosine monophosphate. Pharm Res 1997; 14:1246-51. [PMID: 9327456 DOI: 10.1023/a:1012123411343] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.6] [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: 02/05/2023]
Abstract
PURPOSE To characterize the conjunctival permeability to polar solutes ranging from 182 to 167,000 daltons in molecular weight (m.w.). METHODS Solute transport across the excised pigmented rabbit conjunctiva with a baseline transepithelial electrical resistance (TEER) of 1,285 +/- 46 ohm.cm2 was evaluated in the modified Ussing chamber under open-circuit conditions. The model solutes were mannitol (m.w. 182), 6-carboxyfluorescein (m.w. 376), and fluorescein isothiocyanate-labeled dextrans (FD4, m.w. 4,400-FD150, m.w. 167,000). RESULTS For a given solute, the apparent permeability coefficient (Papp) was independent of solute concentration and direction of transport. As expected, the Papp decreased with solute size, from 27.7 x 10(-8) cm/sec for mannitol to 0.31 x 10(-8) cm/sec for FD150. When the experimental temperature was lowered from 37 degrees C to 4 degrees C. Papp decreased by approximately 50% for FD4 through FD40 and by > 80% for both FD70 and FD150. Equivalent pore analysis, assuming restricted solute diffusion via cylindrical, water-filled pores across the isolated tissue, revealed a radius of 5.5 nm at a pore density of 1.9 x 10(8) pores per cm2. The addition of 1 mM 8-bromo cyclic adenosine monophosphate (8-BrcAMP), known to stimulate Cl- secretion and decrease TEER, to the mucosal side of the conjunctiva increased the transport of mannitol, FD4, and FD40 by 28%, while not affecting FD150 transport. CONCLUSIONS Our findings suggest that polar solutes up to FD40 traverse the conjunctival epithelial barrier primarily by restricted diffusion through equivalent pores of 5.5 nm radius and that solute movement is affected by reduction of TEER. On the other hand, polar solutes of the FD70 or larger may cross the barrier primarily via non-diffusional pathways such as non-specific endocytosis.
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Affiliation(s)
- Y Horibe
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles 90033, USA
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50
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Abstract
PURPOSE To characterize cidofovir (S)-1-(3-hydroxy-2-phosphonylmethoxypropyl) cytosine) transport in the pigmented rabbit conjunctiva and to evaluate the formulation influence on its transport. METHODS The excised pigmented rabbit conjunctiva was mounted in the modified Ussing chamber. Cidofovir transport was initiated by applying 3H-cidofovir to the donor compartment and assayed by measuring the radioactivity accumulated in the receiver fluid over 180 min. RESULTS Cidofovir flux in the mucosal-to-serosal direction increased proportionally with drug concentration over the 0.01 to 1 mM range. Cidofovir transport (0.01 mM) at 37 degrees C in the mucosal-to-serosal direction was not significantly different from that in the opposite direction or from that at 4 degrees C. Hypotonicity (80 mOsm/kg), 0.5% EDTA, and 0.0125% benzalkonium chloride increased the apparent permeability coefficient of cidofovir 3, 21, and 49 times, respectively. This was accompanied by a corresponding 43%, 86%, and 96% reduction in the transconjunctival electrical resistance over 180 min. The reduction in transepithelial electrical resistance elicited by hypotonicity was reversible. There was a good correlation between apparent permeability coefficient and the transconjunctival conductance, suggesting that cidofovir may undergo paracellular passive diffusion in the conjunctiva. CONCLUSION Cidofovir transport in the rabbit conjunctiva may be via paracellular passive diffusion. Formulation changes may improve cidofovir absorption from the conjunctival route.
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Affiliation(s)
- K Hosoya
- Department of Pharmaceutical Sciences, University of Southern California, Los Angeles 90033, USA
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