1
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Ling ML, Ching P, Cheng J, Lang L, Liberali S, Poon P, Shin Y, Sim C. APSIC dental infection prevention and control (IPC) guidelines. Antimicrob Resist Infect Control 2023; 12:53. [PMID: 37254208 DOI: 10.1186/s13756-023-01252-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 05/09/2023] [Indexed: 06/01/2023] Open
Abstract
BACKGROUND The Asia Pacific Society of Infection Control launched the Infection Prevention and Control Guidelines in July 2022. This document describes the guidelines and recommendations for safe practices in dental setting. It aims to highlight practical recommendations in a concise format designed to assist dental facilities at Asia Pacific region in achieving high standards in infection prevention and control practices, staff and patient safety. METHOD The guidelines were developed by an appointed workgroup comprising experts in the Asia Pacific region, following reviews of previously published international guidelines and recommendations relevant to each section. RESULTS It recommends standard precautions as a minimal set of preventive measures to protect staff and prevent cross transmission. Surgical aseptic technique is recommended when procedures are technically complex and longer in duration. Only trained staff are eligible to conduct reprocessing of dental instruments. The design, layout of the dental facility are important factors for successful infection prevention. The facility should also have a Pandemic Preparedness Plan. CONCLUSIONS Dental facilities should aim for excellence in infection prevention and control practices as this is part of patient safety. The guidelines that come with a checklist help dental facilities to identify gaps for improvement to reach this goal.
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Affiliation(s)
- M L Ling
- Singapore General Hospital, Outram Road, Singapore, 169403, Singapore.
| | - P Ching
- The University of Hong Kong, Hong Kong, China
| | - J Cheng
- Taipei Medical University, Taipei, Taiwan
| | - L Lang
- National Healthcare Group Polyclinics, Singapore, Singapore
| | - S Liberali
- University of Adelaide, Adelaide, Australia
| | - P Poon
- Department of Health, Hong Kong, China
| | - Y Shin
- Seoul National University, School of Dentistry, Seoul, South Korea
| | - C Sim
- National Dental Centre, Singapore, Singapore
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2
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Kwart D, He J, Srivatsan S, Lett C, Golubov J, Oswald EM, Poon P, Ye X, Waite J, Zaretsky AG, Haxhinasto S, Au-Yeung E, Gupta NT, Chiu J, Adler C, Cherravuru S, Malahias E, Negron N, Lanza K, Coppola A, Ni M, Song H, Wei Y, Atwal GS, Macdonald L, Oristian NS, Poueymirou W, Jankovic V, Fury M, Lowy I, Murphy AJ, Sleeman MA, Wang B, Skokos D. Cancer cell-derived type I interferons instruct tumor monocyte polarization. Cell Rep 2022; 41:111769. [PMID: 36476866 DOI: 10.1016/j.celrep.2022.111769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 06/29/2022] [Accepted: 11/11/2022] [Indexed: 12/12/2022] Open
Abstract
Monocytes are highly plastic immune cells that modulate antitumor immunity. Therefore, identifying factors that regulate tumor monocyte functions is critical for developing effective immunotherapies. Here, we determine that endogenous cancer cell-derived type I interferons (IFNs) control monocyte functional polarization. Guided by single-cell transcriptomic profiling of human and mouse tumors, we devise a strategy to distinguish and separate immunostimulatory from immunosuppressive tumor monocytes by surface CD88 and Sca-1 expression. Leveraging this approach, we show that cGAS-STING-regulated cancer cell-derived IFNs polarize immunostimulatory monocytes associated with anti-PD-1 immunotherapy response in mice. We also demonstrate that immunosuppressive monocytes convert into immunostimulatory monocytes upon cancer cell-intrinsic cGAS-STING activation. Consistently, we find that human cancer cells can produce type I IFNs that polarize monocytes, and our immunostimulatory monocyte gene signature is enriched in patient tumors that respond to anti-PD-1 immunotherapy. Our work exposes a role for cancer cell-derived IFNs in licensing monocyte functions that influence immunotherapy outcomes.
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Affiliation(s)
- Dylan Kwart
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Jing He
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | | | | | | | | | - Patrick Poon
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Xuan Ye
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | | | | | | | | | | | - Joyce Chiu
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | | | | | | | | | | | | | - Min Ni
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Hang Song
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Yi Wei
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | | | | | | | | | | | - Matthew Fury
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Israel Lowy
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | | | | | - Bei Wang
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA.
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3
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Waite JC, Wang B, Haber L, Hermann A, Ullman E, Ye X, Dudgeon D, Slim R, Ajithdoss DK, Godin SJ, Ramos I, Wu Q, Oswald E, Poon P, Golubov J, Grote D, Stella J, Pawashe A, Finney J, Herlihy E, Ahmed H, Kamat V, Dorvilliers A, Navarro E, Xiao J, Kim J, Yang SN, Warsaw J, Lett C, Canova L, Schulenburg T, Foster R, Krueger P, Garnova E, Rafique A, Babb R, Chen G, Stokes Oristian N, Siao CJ, Daly C, Gurer C, Martin J, Macdonald L, MacDonald D, Poueymirou W, Smith E, Lowy I, Thurston G, Olson W, Lin JC, Sleeman MA, Yancopoulos GD, Murphy AJ, Skokos D. Tumor-targeted CD28 bispecific antibodies enhance the antitumor efficacy of PD-1 immunotherapy. Sci Transl Med 2021; 12:12/549/eaba2325. [PMID: 32581132 DOI: 10.1126/scitranslmed.aba2325] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 06/05/2020] [Indexed: 12/16/2022]
Abstract
Monoclonal antibodies that block the programmed cell death 1 (PD-1) checkpoint have revolutionized cancer immunotherapy. However, many major tumor types remain unresponsive to anti-PD-1 therapy, and even among responsive tumor types, most of the patients do not develop durable antitumor immunity. It has been shown that bispecific antibodies activate T cells by cross-linking the TCR/CD3 complex with a tumor-specific antigen (TSA). The class of TSAxCD3 bispecific antibodies have generated exciting results in early clinical trials. We have recently described another class of "costimulatory bispecifics" that cross-link a TSA to CD28 (TSAxCD28) and cooperate with TSAxCD3 bispecifics. Here, we demonstrate that these TSAxCD28 bispecifics (one specific for prostate cancer and the other for epithelial tumors) can also synergize with the broader anti-PD-1 approach and endow responsiveness-as well as long-term immune memory-against tumors that otherwise do not respond to anti-PD-1 alone. Unlike CD28 superagonists, which broadly activate T cells and induce cytokine storm, TSAxCD28 bispecifics display little or no toxicity when used alone or in combination with a PD-1 blocker in genetically humanized immunocompetent mouse models or in primates and thus may provide a well-tolerated and "off the shelf" combination approach with PD-1 immunotherapy that can markedly enhance antitumor efficacy.
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Affiliation(s)
- Janelle C Waite
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Bei Wang
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Lauric Haber
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Aynur Hermann
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Erica Ullman
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Xuan Ye
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Drew Dudgeon
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Rabih Slim
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Dharani K Ajithdoss
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Stephen J Godin
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Ilyssa Ramos
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Qi Wu
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Erin Oswald
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Patrick Poon
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Jacquelynn Golubov
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Devon Grote
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Jennifer Stella
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Arpita Pawashe
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Jennifer Finney
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Evan Herlihy
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Hassan Ahmed
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Vishal Kamat
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Amanda Dorvilliers
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Elizabeth Navarro
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Jenny Xiao
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Julie Kim
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Shao Ning Yang
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Jacqueline Warsaw
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Clarissa Lett
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Lauren Canova
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Teresa Schulenburg
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Randi Foster
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Pamela Krueger
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Elena Garnova
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Ashique Rafique
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Robert Babb
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Gang Chen
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | | | - Chia-Jen Siao
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Christopher Daly
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Cagan Gurer
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Joel Martin
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Lynn Macdonald
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Douglas MacDonald
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - William Poueymirou
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Eric Smith
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Israel Lowy
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Gavin Thurston
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - William Olson
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - John C Lin
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Matthew A Sleeman
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - George D Yancopoulos
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Andrew J Murphy
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA.
| | - Dimitris Skokos
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA.
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4
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Skokos D, Waite JC, Haber L, Crawford A, Hermann A, Ullman E, Slim R, Godin S, Ajithdoss D, Ye X, Wang B, Wu Q, Ramos I, Pawashe A, Canova L, Vazzana K, Ram P, Herlihy E, Ahmed H, Oswald E, Golubov J, Poon P, Havel L, Chiu D, Lazo M, Provoncha K, Yu K, Kim J, Warsaw JJ, Stokes Oristian N, Siao CJ, Dudgeon D, Huang T, Potocky T, Martin J, MacDonald D, Oyejide A, Rafique A, Poueymirou W, Kirshner JR, Smith E, Olson W, Lin J, Thurston G, Sleeman MA, Murphy AJ, Yancopoulos GD. A class of costimulatory CD28-bispecific antibodies that enhance the antitumor activity of CD3-bispecific antibodies. Sci Transl Med 2021; 12:12/525/eaaw7888. [PMID: 31915305 DOI: 10.1126/scitranslmed.aaw7888] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 05/13/2019] [Accepted: 11/25/2019] [Indexed: 12/11/2022]
Abstract
T cell activation is initiated upon binding of the T cell receptor (TCR)/CD3 complex to peptide-major histocompatibility complexes ("signal 1"); activation is enhanced by engagement of a second "costimulatory" receptor, such as the CD28 receptor on T cells binding to its cognate ligand(s) on the target cell ("signal 2"). CD3-based bispecific antibodies act by replacing conventional signal 1, linking T cells to tumor cells by binding a tumor-specific antigen (TSA) with one arm of the bispecific and bridging to TCR/CD3 with the other. Although some of these so-called TSAxCD3 bispecifics have demonstrated promising antitumor efficacy in patients with cancer, their activity remains to be optimized. Here, we introduce a class of bispecific antibodies that mimic signal 2 by bridging TSA to the costimulatory CD28 receptor on T cells. We term these TSAxCD28 bispecifics and describe two such bispecific antibodies: one specific for ovarian and the other for prostate cancer antigens. Unlike CD28 superagonists, which broadly activate T cells and resulted in profound toxicity in early clinical trials, these TSAxCD28 bispecifics show limited activity and no toxicity when used alone in genetically humanized immunocompetent mouse models or in primates. However, when combined with TSAxCD3 bispecifics, they enhance the artificial synapse between a T cell and its target cell, potentiate T cell activation, and markedly improve antitumor activity of CD3 bispecifics in a variety of xenogeneic and syngeneic tumor models. Combining this class of CD28-costimulatory bispecific antibodies with the emerging class of TSAxCD3 bispecifics may provide well-tolerated, off-the-shelf antibody therapies with robust antitumor efficacy.
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Affiliation(s)
- Dimitris Skokos
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA.
| | - Janelle C Waite
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Lauric Haber
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Alison Crawford
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Aynur Hermann
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Erica Ullman
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Rabih Slim
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Stephen Godin
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Dharani Ajithdoss
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Xuan Ye
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Bei Wang
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Qi Wu
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Ilyssa Ramos
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Arpita Pawashe
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Lauren Canova
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Kristin Vazzana
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Priyanka Ram
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Evan Herlihy
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Hassan Ahmed
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Erin Oswald
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Jacquelynn Golubov
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Patrick Poon
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Lauren Havel
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Danica Chiu
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Miguel Lazo
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Kathleen Provoncha
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Kevin Yu
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Julie Kim
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Jacqueline J Warsaw
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | | | - Chia-Jen Siao
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Drew Dudgeon
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Tammy Huang
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Terra Potocky
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Joel Martin
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Douglas MacDonald
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Adelekan Oyejide
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Ashique Rafique
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - William Poueymirou
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Jessica R Kirshner
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Eric Smith
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - William Olson
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - John Lin
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Gavin Thurston
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Matthew A Sleeman
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - Andrew J Murphy
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
| | - George D Yancopoulos
- Regeneron Pharmaceuticals, 777 Old Saw Mill River Road, Tarrytown, NY 10591, USA
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5
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Wang B, Zhang W, Jankovic V, Golubov J, Poon P, Oswald EM, Gurer C, Wei J, Ramos I, Wu Q, Waite J, Ni M, Adler C, Wei Y, Macdonald L, Rowlands T, Brydges S, Siao J, Poueymirou W, MacDonald D, Yancopoulos GD, Sleeman MA, Murphy AJ, Skokos D. Combination cancer immunotherapy targeting PD-1 and GITR can rescue CD8+ T cell dysfunction and maintain memory phenotype. Sci Immunol 2019; 3:3/29/eaat7061. [PMID: 30389797 DOI: 10.1126/sciimmunol.aat7061] [Citation(s) in RCA: 118] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 10/11/2018] [Indexed: 12/13/2022]
Abstract
Most patients with cancer do not develop durable antitumor responses after programmed cell death protein 1 (PD-1) or programmed cell death ligand 1(PD-L1) checkpoint inhibition monotherapy because of an ephemeral reversal of T cell dysfunction and failure to promote long-lasting immunological T cell memory. Activating costimulatory pathways to induce stronger T cell activation may improve the efficacy of checkpoint inhibition and lead to durable antitumor responses. We performed single-cell RNA sequencing of more than 2000 tumor-infiltrating CD8+ T cells in mice receiving both PD-1 and GITR (glucocorticoid-induced tumor necrosis factor receptor-related protein) antibodies and found that this combination synergistically enhanced the effector function of expanded CD8+ T cells by restoring the balance of key homeostatic regulators CD226 and T cell immunoreceptor with Ig and ITIM domains (TIGIT), leading to a robust survival benefit. Combination therapy decreased CD8+ T cell dysfunction and induced a highly proliferative precursor effector memory T cell phenotype in a CD226-dependent manner. PD-1 inhibition rescued CD226 activity by preventing PD-1-Src homology region 2 (SHP2) dephosphophorylation of the CD226 intracellular domain, whereas GITR agonism decreased TIGIT expression. Unmasking the molecular pathways driving durable antitumor responses will be essential to the development of rational approaches to optimizing cancer immunotherapy.
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Affiliation(s)
- Bei Wang
- Regeneron Pharmaceuticals,Tarrytown, New York, NY 10591, USA
| | - Wen Zhang
- Regeneron Pharmaceuticals,Tarrytown, New York, NY 10591, USA
| | | | | | - Patrick Poon
- Regeneron Pharmaceuticals,Tarrytown, New York, NY 10591, USA
| | - Erin M Oswald
- Regeneron Pharmaceuticals,Tarrytown, New York, NY 10591, USA
| | - Cagan Gurer
- Regeneron Pharmaceuticals,Tarrytown, New York, NY 10591, USA
| | - Joyce Wei
- Regeneron Pharmaceuticals,Tarrytown, New York, NY 10591, USA
| | - Ilyssa Ramos
- Regeneron Pharmaceuticals,Tarrytown, New York, NY 10591, USA
| | - Qi Wu
- Regeneron Pharmaceuticals,Tarrytown, New York, NY 10591, USA
| | - Janelle Waite
- Regeneron Pharmaceuticals,Tarrytown, New York, NY 10591, USA
| | - Min Ni
- Regeneron Pharmaceuticals,Tarrytown, New York, NY 10591, USA
| | - Christina Adler
- Regeneron Pharmaceuticals,Tarrytown, New York, NY 10591, USA
| | - Yi Wei
- Regeneron Pharmaceuticals,Tarrytown, New York, NY 10591, USA
| | - Lynn Macdonald
- Regeneron Pharmaceuticals,Tarrytown, New York, NY 10591, USA
| | - Tracey Rowlands
- Regeneron Pharmaceuticals,Tarrytown, New York, NY 10591, USA
| | | | - Jean Siao
- Regeneron Pharmaceuticals,Tarrytown, New York, NY 10591, USA
| | | | | | | | | | - Andrew J Murphy
- Regeneron Pharmaceuticals,Tarrytown, New York, NY 10591, USA
| | - Dimitris Skokos
- Regeneron Pharmaceuticals,Tarrytown, New York, NY 10591, USA.
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6
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Yoong J, Chosich B, Burgess M, Earnest A, Runacres F, William L, Franco M, Poon P. Cancer patients’ perceptions of palliative care. Ann Oncol 2018. [DOI: 10.1093/annonc/mdy295.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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7
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Hosking SPM, Franco ME, Poon P, William L. Bilateral cordotomy post-failure of intrathecal analgesia in a palliative care setting. Intern Med J 2015; 45:586-7. [PMID: 25955466 DOI: 10.1111/imj.12743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 10/02/2014] [Indexed: 11/27/2022]
Affiliation(s)
- S P M Hosking
- Supportive and Palliative Care Unit, Monash Medical Centre, Monash Health, Melbourne, Victoria, Australia
| | - M E Franco
- Supportive and Palliative Care Unit, Monash Medical Centre, Monash Health, Melbourne, Victoria, Australia.,Faculty of Medicine, Monash University, Melbourne, Victoria, Australia
| | - P Poon
- Supportive and Palliative Care Unit, Monash Medical Centre, Monash Health, Melbourne, Victoria, Australia.,Faculty of Medicine, Monash University, Melbourne, Victoria, Australia.,Eastern Palliative Care Association, Melbourne, Victoria, Australia
| | - L William
- Supportive and Palliative Care Unit, Monash Medical Centre, Monash Health, Melbourne, Victoria, Australia.,Faculty of Medicine, Monash University, Melbourne, Victoria, Australia.,Palliative Care Department, Eastern Health, Melbourne, Victoria, Australia
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8
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Abstract
We investigated the anatomy of the dorsal cutaneous branch of the ulnar nerve in 32 upper limbs in cadavers. The dorsal cutaneous branch of the ulnar nerve originated on average 5.1 cm proximal to the ulnar styloid process and 1.9 cm palmar and radial to the subcutaneous border of the ulna. It crossed the subcutaneous border 0.2 cm proximal to the ulnar styloid process. In all cases it displaced further away in full pronation. We recommend cautious dissection when approaching within 2.5 cm of the ulnar styloid process. We also recommend making the initial incision in full pronation and just along the dorsal aspect of the subcutaneous border of the ulna.
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Affiliation(s)
- R Puna
- North Shore Hospital, North Shore City, New Zealand.
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Affiliation(s)
- M P O'Connell
- Academic Department Obstetrics and Gynaecology, Hull Maternity Hospital, UK
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Sutherland AG, Barrow A, Mulhall K, Meek RMD, Pollock R, Poon P, Williams R. What is the point of the American-British-Canadian (ABC) fellowship? J Bone Joint Surg Br 2009; 91:138-140. [PMID: 19092019 DOI: 10.1302/0301-620x.91b1.21820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Affiliation(s)
- A G Sutherland
- University of Aberdeen, Polwarth Building, Foresterhill, Aberdeen, UK
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Sutherland TF, Levings CD, Petersen SA, Poon P, Piercey B. The use of meiofauna as an indicator of benthic organic enrichment associated with salmonid aquaculture. Mar Pollut Bull 2007; 54:1249-61. [PMID: 17585949 DOI: 10.1016/j.marpolbul.2007.03.024] [Citation(s) in RCA: 8] [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] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Revised: 03/29/2007] [Accepted: 03/30/2007] [Indexed: 05/15/2023]
Abstract
Sediment chemistry and meiofaunal samples were collected in the Broughton Archipelago, British Columbia, to examine the relationship between sediment variables and meiofauna diversity across near- and far-field gradients surrounding several finfish aquaculture operations. The sediment variables examined consisted of free sulfide concentrations, redox potential (E(NHE)), organic content, and sediment grain size. A strong trend between sediment texture and organic content was observed across all sampling locations, which reflected a wide range of sediment types (sand-silt) that exist within the Broughton Archipelago. The abundance of certain meiofaunal groups (kinorhynchs, crustaceans, polychaetes) declined in an asymptotic fashion with increasing free sulfide concentrations, an indicator of benthic organic enrichment. Within these relationships, low meiofaunal abundances occurred in fine sediments associated with higher organic contents. Although other groups (nematodes, foraminifera) showed a slight decline in abundance with increasing organic enrichment, a high amount of variability in abundance was observed at high free sulfide concentrations, rendering these groups not suitable as indicators of organic enrichment. This study reports both horizontal and vertical trends in meiofaunal distributions relative to free sulfide concentrations. The abundance of nematode and crustacean taxa decreased with sediment depth as well as increasing sulfide concentration, while polycheate abundance increased with increasing free sulfide concentration. The ratio of nematodes to copepods was also shown to represent the degree of organic loading associated with aquaculture operations and its application as an indicator of benthic impact is discussed.
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Affiliation(s)
- T F Sutherland
- Fisheries and Oceans Canada, DFO-UBC Centre for Aquaculture and Environmental Research, 4160 Marine Drive, West Vancouver, BC, Canada
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Abstract
Although there is general consensus that the hippocampus is not critically involved in the acquisition of fear conditioned to an explicit conditioned stimulus (CS), the extent to which the hippocampus participates in contextual fear conditioning remains unclear. To further characterize the potential role of the hippocampus in contextual fear conditioning, the present experiments examined the effect of excitotoxic lesions of dorsal hippocampus on the acquisition of a novel contextual fear conditioning paradigm in which a unimodal (olfactory) cue served to disambiguate discrete "contexts" within a single behavioral training chamber. Selective lesions of dorsal hippocampus severely attenuated olfactory contextual conditioning without affecting conditioning to an explicit auditory or olfactory CS. Additional experiments indicate that these contextual conditioning deficits cannot be attributed to a lesion-induced decrement in olfactory perception, a preferential impairment of "weak" forms of conditioning, or hyperactivity. Thus, the hippocampus appears to contribute importantly to the acquisition of fear conditioned to explicitly nonspatial, unimodal, temporally, and spatially diffuse contextual stimuli.
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Affiliation(s)
- Tim Otto
- Program in Behavioral Neuroscience, Department of Psychology, Rutgers University, New Brunswick, New Jersey 08854, USA.
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Lindsay M, Lee A, Chan K, Poon P, Han LK, Wong WCW, Wong S. Does pulmonary rehabilitation give additional benefit over tiotropium therapy in primary care management of chronic obstructive pulmonary disease? Randomized controlled clinical trial in Hong Kong Chinese. J Clin Pharm Ther 2005; 30:567-73. [PMID: 16336289 DOI: 10.1111/j.1365-2710.2005.00686.x] [Citation(s) in RCA: 12] [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] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate whether multidisciplinary pulmonary rehabilitation programme (PRP) provides additional benefit over tiotropium therapy in managing chronic obstructive pulmonary disease (COPD) in primary care. DESIGN A randomized controlled trial to analyse the difference in outcomes of COPD patients receiving tiotropium plus PRP vs. tiotropium treatment alone. SETTING Two primary care teaching clinics affiliated with a university which serves a population of 600,000. PARTICIPANTS Fifty primary care COPD patients. METHODS Fifty subjects underwent spirometry and their status of COPD was confirmed by using the Vitalograph Gold Standard. They were then assessed by the 6-min walking distance (6MWD), Peak Visual Analogue Scale (Peak VAS) and Chronic Respiratory Disease Questionnaire (CRQ). All subjects were given tiotropium to optimize their treatment. After a 6-week period, half were randomized to the intervention group (i.e. receiving PRP), whereas the rest were randomized to control group which received only medication. Spirometry, 6MWD, Peak VAS and CRQ were performed in both groups at 6 weeks, 12 weeks and 3 months. OUTCOMES Spirometry, 6MWD, Peak VAS and CRQ. RESULTS Significant improvement (P < 0.05) was seen in 6MWD, symptoms of dyspnoea measured by Peak VAS and CRQ. The improvement was sustained at 3-month follow-up. However, no additional significant improvement was seen in the intervention group when compared with control. CONCLUSION Tiotropium therapy has improved health outcomes in COPD patients in primary care settings. A 6 weekly PRP did not give any additional benefits in patients already given tiotropium.
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Affiliation(s)
- M Lindsay
- Family Medicine Unit, Department of Community and Family Medicine, The Chinese University of Hong Kong
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Abstract
Background: Sucralose is a unique disaccharide probe which is stable in the colon and can be used to assess permeability over the whole gut. Additional information can be gained when sucralose is administered in combination with lactulose and a monosaccharide such as L-rhamnose in the form of a 'triple sugar test.' We describe a simple assay for urinary sucralose by HPLC with refractive index detection (HPLC-RI). Methods: Phenyl-β-D-glucopyranoside (internal standard) was added to 10 mL of urine, which was then passed through a 0.45 μm syringe filter. Elution was with 30% methanol (1 mL/min) on a reverse-phase C18 column. Detection was by refractive index, and integration based upon peak areas. Sixty standards of sucralose in human urine were analysed in order to quantify analytical variation. Results: The standard curve for urinary sucralose was linear from 25 to 500 mg/L ( r>0.99). The limit of detection was 11 mg/L. Analytical recovery of sucralose at concentrations of 25, 50 and 100 mg/L was 101.5% (CV 7.59%), 102.9% (CV 5.82%) and 105.0% (CV 4.26%), respectively Conclusions: The technique described represents a simple assay for urinary sucralose which performed with acceptable accuracy and precision and should facilitate the use of the triple sugar test in clinical research.
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Affiliation(s)
- A D G Anderson
- Combined Gastroenterology Research Group, Scarborough Hospital, Woodlands Drive, Scarborough YO12 6QL, UK
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16
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Abstract
AIM Conventional dual sugar tests of intestinal permeability assess only the stomach and small intestine. A novel triple sugar method of assessing colonic permeability has recently been described in animals. This utilizes the non-fermented sweetener sucralose, in addition to conventional sugars. It has been postulated that this test enables the simultaneous assessment of small-intestinal and colonic barrier function in humans. The aim of this study was to evaluate the triple sugar test using healthy volunteers and ileostomists. METHODS Twenty-one healthy volunteers and 18 ileostomists underwent the triple sugar test. After an overnight fast, subjects drank a solution containing lactulose (5 g), rhamnose (1 g) and sucralose (5 g). Urine was collected for 0-5 h and 5-19 h. Urinary sugars were quantified using HPLC, and 5 and 24-h excretion calculated. Nineteen control subjects and 16 ileostomists also underwent a 51Cr-EDTA permeability test. Permeability data were presented as medians (IQR), and differences between groups analysed with Mann-Whitney U-tests. RESULTS Lactulose excretion and the 5-h lactulose/rhamnose (L/R) ratio were similar in controls and ileostomists [L/R ratio 0.024 (0.022-0.034) vs. 0.025 (0.022-0.035), P = 0.955]. Twenty-four hours excretion of sucralose was significantly higher in control subjects compared with ileostomists [1.41% (1.17-1.68) vs. 0.96% (0.64-1.2), P = 0.003]. The same pattern was seen with 51Cr-EDTA [2.73% (2.06-3.76) vs. 2.06% (1.55-2.71), P = 0.037] and with lactulose [0.52% (0.42-0.60) vs. 0.25% (0.16-0.35), P = 0.002]. CONCLUSIONS Both sucralose and 51Cr-EDTA underwent significant colonic absorption. A significant amount of lactulose also appeared to be absorbed in the colon. This unexpected finding requires further study.
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Affiliation(s)
- A D G Anderson
- Combined Gastroenterology Research Group, Scarborough Hospital, Scarborough, UK
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Kwok T, Cheng G, Lai WK, Poon P, Woo J, Pang CP. Use of fasting urinary methylmalonic acid to screen for metabolic vitamin B12 deficiency in older persons. Nutrition 2004; 20:764-8. [PMID: 15325684 DOI: 10.1016/j.nut.2004.06.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [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: 10/26/2022]
Abstract
OBJECTIVES We sought to determine the cutoffs of fasting urinary methylmalonic acid (MMA) indicating elevated and mildly elevated serum MMA concentrations in older persons. METHODS We studied 113 female Chinese vegetarians older than 55 y with normal renal function. Fasting serum samples were obtained for measurement of vitamin B12, MMA, and folate and tests of renal function. A fasting urine sample was collected for MMA measurement by the stable-isotope dilution method. The correlation between serum and urinary MMA levels was examined. The optimal cutoffs of urinary MMA for predicting elevated and mildly elevated serum MMA were estimated by use of receiver operating characteristic curves. RESULTS Fasting urinary and serum MMA levels were linearly correlated. Pearson's correlation coefficient was 0.94. The cutoff of fasting urinary MMA of 2 microM/mM of creatinine had a sensitivity of 79%, a specificity of 85%, and a positive predictive value of 93% for elevated serum MMA (> 0.4 microM/L). A cutoff of 1.5 microM/mM of creatinine had a sensitivity of 86%, a specificity of 85%, and a positive predictive value of 95% for mildly elevated serum MMA (> 0.3 microM/L). Both cutoffs had high positive predictive values for subnormal vitamin B12 concentrations. CONCLUSION Overnight fasting urinary MMA concentrations have a strong linear relation to serum MMA in older vegetarians without renal impairment. Urinary MMA is potentially useful as a screening tool for metabolic vitamin B12 deficiency in older persons.
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Affiliation(s)
- T Kwok
- Department of Medicine and Therapeutics, Shatin, Hong Kong, Peoples' Republic of China.
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Abstract
A 37-year-old man died as a result of exposure to carbon monoxide within an apartment. An investigation of the apartment showed no gas appliances or gas supply to the apartment and no evidence of any combustion event to any part of the apartment or roof space. Inhalation of dichloromethane was excluded. Heating to the apartment was found to be via an electrical storage heater, the examination of which revealed that the cast-iron core and insulating material showed evidence of heat damage with significant areas devoid of carbon. This electric storage heater is hypothesized to be the source of carbon for the fatal production of carbon monoxide within the apartment.
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Affiliation(s)
- D R Morgan
- Department of Pathology, Scarborough Hospital, North Yorkshire, UK
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Chua R, Weeks DJ, Ricker KL, Poon P. Influence of operator orientation on relative organizational mapping and spatial compatibility. Ergonomics 2001; 44:751-765. [PMID: 11450874 DOI: 10.1080/00140130117522] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Following up on a study by Worringham and Beringer (1989) that examined the influence of operator orientation on visual-motor performance, Experiment 1 employed a choice reaction time paradigm in which participants had to make rapid, discrete movements with a lever in response to a discrete stimulus. In Experiment 2, participants had to synchronize rhythmic movements with an oscillating visual display. Operator orientation with respect to stimulus display and response array locations was varied to examine the influence of global spatial relations. Display orientation was varied to examine the influence of spatial configuration. Mapping rules were varied to examine the effects of spatial mapping. In Experiment 1, the spatial mapping that yielded faster responses was dependent upon the stimulus display-response array configuration and the global relation. Under a parallel configuration, participants appeared to code the spatial aspects of the stimulus display and response in a manner that was unaffected by the global spatial relation. Under an orthogonal configuration, spatial mapping effects were dependent upon the global relation. In Experiment 2, the global spatial relation did not have an impact on the uniformity of co-ordination under different configuration or mapping conditions. Spatial configuration influenced whether or not differences between spatial mapping rules emerged. Together, the results speak to the relative nature of stimulus-response coding that underlie compatibility phenomena. In addition, the results have potential importance for the design of human-machine systems that allow flexibility in operator orientation.
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Affiliation(s)
- R Chua
- Perceptual-Motor Dynamics Laboratory, School of Human Kinetics, University of British Columbia, Vancouver, Canada
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Leung WK, Ma PK, Choi PC, Ching JY, Ng AC, Poon P, Woo KS, Sung JJ. Correlation between Helicobacter pylori infection, gastric inflammation and serum homocysteine concentration. Helicobacter 2001; 6:146-50. [PMID: 11422470 DOI: 10.1046/j.1523-5378.2001.00021.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [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: 01/26/2023]
Abstract
BACKGROUND Epidemiological studies have suggested a link between chronic Helicobacter pylori infection and ischemic heart disease but the underlying mechanism remains elusive. We hypothesized that H. pylori-associated chronic gastritis causes impairment of absorption of vitamin cofactors that are essential in the metabolism of homocysteine and results in hyperhomocysteinemia. MATERIALS AND METHODS Forty-nine dyspeptic patients were studied. H. pylori infection was defined by rapid urease test and histology. Fasting serum homocysteine level, which was measured by a validated commercial fluorescence polarization immunoassay, was correlated with H. pylori infection statuses and gastric histology. H. pylori-infected patients were followed up for 24 weeks post eradication for changes in serum homocysteine concentration. RESULTS Univariate analyses showed that serum homocysteine level correlated with increasing age (p <.001), male sex (p =.003) and smoking habit (p =.025). There was no significant difference in serum homocysteine levels between H. pylori infected and uninfected subjects (median 10.5 vs. 10.2 micromol/l). After successful eradication of the bacterium, there was no significant reduction in homocysteine level. Moreover, there was no correlation between homocysteine level and gastric histology including H. pylori density, activity and inflammation scores, presence of atrophy or intestinal metaplasia. CONCLUSIONS The postulated link between H. pylori infection and ischemic heart disease, if it actually exists, is unlikely to be mediated through hyperhomocysteinemia.
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Affiliation(s)
- W K Leung
- Department of Anatomical & Cellular Pathology, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
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Chu I, Lecavalier P, Håkansson H, Yagminas A, Valli VE, Poon P, Feeley M. Mixture effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin and polychlorinated biphenyl congeners in rats. Chemosphere 2001; 43:807-14. [PMID: 11372869 DOI: 10.1016/s0045-6535(00)00437-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Concern of the toxic effects and bioaccumulation of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and polychlorinated biphenyls in the environment continues to be a focus of research in persistent organochlorine contaminants. Groups of five adult female S.D. rats were administered by gavage 0, 2.5, 25, 250 or 1000 ng TCDD/kg body weight/day or TCDD in combination with a mixture of PCB congeners (PCBs) at 2 or 20 microg/kg b.w./day for a period of 28 days. Growth suppression, increased absolute and relative liver weights, and decreased thymic weight were observed in either the 1000 ng TCDD group alone, or the groups receiving a mixture of 1000 ng TCDD + 2 microg PCBs. The TCDD induced increases in liver and thymic weights were not altered by co-administration with PCBs, however, growth suppression appeared to be more pronounced in the group receiving 1000 ng TCDD + 2 microg PCBs than with TCDD alone. Treatment with TCDD at 250 ng and 1000 ng/kg resulted in a significant increase in hepatic microsomal methoxy resorufin-O-demethylase and ethoxy resorufin-O-deethylase activities which were antagonized by co-administration with PCBs. Similarly, effects of 250 ng TCDD on serum cholesterol and liver UDP glucuronosyl transferase activity and ascorbic acid were significantly reduced by co-administration with 20 microg PCBs. Other biochemical effects elicited by treatment with 1000 ng TCDD, but not affected by co-administration with PCBs include the following: increased serum albumin, decreased liver vitamin A, and increased kidney vitamin A and liver microsomal glutathione-S-transferase activity. While decreased hemoglobin, platelet, packed cell volume and red cell indices were observed in TCDD treated rats, no interactive effects were seen. The above results indicate that the mixture effects of PCBs and TCDD may be additive or antagonistic depending on the dose level and endpoints measured. For the purpose of predicting mixture effects, knowledge of mechanisms of action and toxicokinetics is required.
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Affiliation(s)
- I Chu
- Environmental Health Centre, Ottawa, Ont., Canada.
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Abstract
BACKGROUND Abnormal regulation in the coagulation and fibrinolytic system may play an important role in mediating glomerular damage in lupus nephritis. Indeed, glomerular thrombosis occurs frequently in lupus nephritis and predicts the future development of glomerular sclerosis. In the murine model of active lupus nephritis, plasminogen activator inhibitor-1 (PAI-1) gene was overexpressed throughout the kidney, both within the glomeruli and also in tubules and vessels. The level of PAI-1 expression in the tissues appeared to correlate with the progression of lupus nephritis. Recently, a single base pair insertion/deletion 4G/5G polymorphism of the PAI-1 gene has been identified and shown to alter plasma PAI-1 activity. This study was therefore conducted to determine the association of the 4G/5G polymorphism of the PAI-1 gene with the development and severity of lupus nephritis. METHODS The PAI-1 gene polymorphism of 118 systemic lupus erythematosus (SLE) patients and 103 healthy controls who were gender and age matched was determined using standard polymerase chain reaction. PAI-1 genotype results were studied in relationship to the development and severity of lupus nephritis. RESULTS Allele frequencies of 4G/5G allele were 0.59/0.41 in lupus patients and 0.59/0.41 in controls (P = 1.000). No significant difference was noted in the genotype distribution between SLE patients with and without nephritis. However, lupus nephritis patients with the 4G4G genotype showed significantly heavier proteinuria (5.0 vs. 3.7 g/day; P = 0.023) when compared with patients with 4G5G and 5G5G genotypes. Also, 73.3% patients with 4G4G had an activity index > or =8 versus 37.3% patients with 4G5G and 5G5G (P = 0.003). Extensive necrotizing lesions were seen in 51.7% patients with 4G4G as compared with 23.5% patients with 4G5G and 5G5G (P = 0.014). The association of the 4G4G gene polymorphism with a higher nephritis activity and more severe necrotizing lesions persisted when only class III and class IV nephritis patients were studied. On the other hand, no significant association was noted between the PAI-1 gene polymorphism and the chronicity of the nephritis. CONCLUSION These findings suggest that the 4G/5G polymorphism of the PAI-1 gene is associated with the activity but not the chronicity of lupus nephritis. The presence of the 4G4G genotype does not increase the risk of developing SLE or lupus nephritis, but predicts the development of higher nephritis activity and more extensive necrotizing lesions.
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Affiliation(s)
- A Y Wang
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, The Prince of Wales Hospital, Hong Kong, China
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Woo K, Chook P, Chiu R, Fung K, Lau J, Poon P, Chan W, Tse K, Chung H, Tang K, Yip G, Sanderson J, Woo J. The prevalence of hyperhomocysteinaemia in coronary artery disease: A case-control study. Heart Lung Circ 2000. [DOI: 10.1046/j.1443-9506.2000.06966.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abstract
Glycogen storage disease type 1b (GSD1b) is an autosomal recessive inborn error of metabolism caused by deficiency of glucose-6-phosphate translocase (G6PT1). Current laboratory diagnosis for GSD1b is established by a functional enzyme assay of glucose-6-phosphatase in both fresh and detergent-treated liver homogenates. This procedure requires liver biopsy and is impractical for routine prenatal diagnosis owing to the high morbidity of fetal liver biopsy. Recently, the gene for GSD1b has been cloned and the prevalent mutations in different ethnic groups have been determined. In this study, prenatal molecular diagnosis was performed for a Chinese family in which a previous child was born homozygous for the G149E mutation. We detected genomic sequence variants by heteroduplex formation, followed by denaturing high performance liquid chromatography (DHPLC). With this method, post-PCR analysis was shortened to 7 min. In the case we analysed, PCR products amplified from the fetal DNA yielded a single peak in the chromatogram, indicating a homozygous state in the fetus. When wild-type PCR products were mixed with fetal PCR products, two peaks were observed, indicating that the fetus was homozygous for the parental (G149E) mutation. Sequencing results confirmed this diagnosis. As a result, the pregnancy was terminated and the diagnosis was confirmed on DNA analysis of the aborted fetus. We show here that DNA mutation analysis can be used in the prenatal diagnosis of GSD1b and that DHPLC promises to be a robust technique for this and other prenatal molecular diagnoses.
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Affiliation(s)
- C W Lam
- Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China.
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25
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Abstract
Glycogen storage disease type 1b (GSD1b) is an autosomal recessive inborn error of metabolism caused by deficiency of glucose-6-phosphate translocase (G6PT1). Current laboratory diagnosis for GSD1b is established by a functional enzyme assay of glucose-6-phosphatase in both fresh and detergent-treated liver homogenates. This procedure requires liver biopsy and is impractical for routine prenatal diagnosis owing to the high morbidity of fetal liver biopsy. Recently, the gene for GSD1b has been cloned and the prevalent mutations in different ethnic groups have been determined. In this study, prenatal molecular diagnosis was performed for a Chinese family in which a previous child was born homozygous for the G149E mutation. We detected genomic sequence variants by heteroduplex formation, followed by denaturing high performance liquid chromatography (DHPLC). With this method, post-PCR analysis was shortened to 7 min. In the case we analysed, PCR products amplified from the fetal DNA yielded a single peak in the chromatogram, indicating a homozygous state in the fetus. When wild-type PCR products were mixed with fetal PCR products, two peaks were observed, indicating that the fetus was homozygous for the parental (G149E) mutation. Sequencing results confirmed this diagnosis. As a result, the pregnancy was terminated and the diagnosis was confirmed on DNA analysis of the aborted fetus. We show here that DNA mutation analysis can be used in the prenatal diagnosis of GSD1b and that DHPLC promises to be a robust technique for this and other prenatal molecular diagnoses.
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Affiliation(s)
- C W Lam
- Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China.
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Wong TY, Poon P, Szeto CC, Chan JC, Li PK. Association of plasminogen activator inhibitor-1 4G/4G genotype and type 2 diabetic nephropathy in Chinese patients. Kidney Int 2000. [PMID: 10652041 DOI: 10.1046/j.1523-1755.2000.t01-1-00884.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Plasminogen activator inhibitor-1 (PAI-1) is a key regulator of fibrinolytic pathway and extracellular matrix (ECM) turnover. Because diabetic nephropathy is characterized by the presence of basement membrane thickening and mesangial expansion, we examined the role of PAI-1 gene polymorphisms in the development of type 2 diabetic nephropathy. Evidence also suggested that the PA/plasmin system and the renin-angiotensin system (RAS) interact together to affect the risk of fibrosis and thrombosis. Hence, we also studied the synergistic effect between PAI-1 and angiotensin-converting enzyme (ACE) gene polymorphisms. METHODS The PAI-1 and ACE (D/I) gene polymorphisms were examined in a cohort of Chinese type 2 diabetic patients who had diabetes for an average of 14 years. These patients were sex and age matched. Group A (N = 46) consisted of patients without diabetic nephropathy (normoalbuminuric with creatinine <120 micromol/L), and group B (N = 95) was with diabetic nephropathy (with albuminuria or renal impairment, including patients on dialysis). RESULTS Patients with type 2 diabetic nephropathy had a higher frequency of PAI-1 (4G/4G) genotypes than those without nephropathy [4G/4G:4G/5G:5G/5G = 41:38:21 (%) vs. 15:65:20(%), P = 0.005]. Diabetic patients with coexistence of PAI-1 4G/4G genotype and ACE D alleles had a higher incidence of diabetic nephropathy (22 vs. 7%, P = 0.012) than those with other combinations of genotypes. Multivariate logistic regression analysis showed that PAI-1 4G/4G (P = 0.01) and the prevalence of hypertension (P < 0.0001) are independent risk factors of development of type 2 diabetic nephropathy. CONCLUSIONS These results suggest that the PAI-1 4G/4G genotype is associated with an increased risk for type 2 diabetic nephropathy in Chinese patients, which is an independent risk factor for the development of nephropathy. The PAI-1 4G/4G genotype also exhibits a synergistic effect with the ACE D allele on development of diabetic nephropathy.
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Affiliation(s)
- T Y Wong
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, The Prince of Wales Hospital, Shatin, Hong Kong
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Wong TY, Poon P, Szeto CC, Chan JC, Li PK. Association of plasminogen activator inhibitor-1 4G/4G genotype and type 2 diabetic nephropathy in Chinese patients. Kidney Int 2000; 57:632-8. [PMID: 10652041 DOI: 10.1046/j.1523-1755.2000.00884.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [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: 11/20/2022]
Abstract
BACKGROUND Plasminogen activator inhibitor-1 (PAI-1) is a key regulator of fibrinolytic pathway and extracellular matrix (ECM) turnover. Because diabetic nephropathy is characterized by the presence of basement membrane thickening and mesangial expansion, we examined the role of PAI-1 gene polymorphisms in the development of type 2 diabetic nephropathy. Evidence also suggested that the PA/plasmin system and the renin-angiotensin system (RAS) interact together to affect the risk of fibrosis and thrombosis. Hence, we also studied the synergistic effect between PAI-1 and angiotensin-converting enzyme (ACE) gene polymorphisms. METHODS The PAI-1 and ACE (D/I) gene polymorphisms were examined in a cohort of Chinese type 2 diabetic patients who had diabetes for an average of 14 years. These patients were sex and age matched. Group A (N = 46) consisted of patients without diabetic nephropathy (normoalbuminuric with creatinine <120 micromol/L), and group B (N = 95) was with diabetic nephropathy (with albuminuria or renal impairment, including patients on dialysis). RESULTS Patients with type 2 diabetic nephropathy had a higher frequency of PAI-1 (4G/4G) genotypes than those without nephropathy [4G/4G:4G/5G:5G/5G = 41:38:21 (%) vs. 15:65:20(%), P = 0.005]. Diabetic patients with coexistence of PAI-1 4G/4G genotype and ACE D alleles had a higher incidence of diabetic nephropathy (22 vs. 7%, P = 0.012) than those with other combinations of genotypes. Multivariate logistic regression analysis showed that PAI-1 4G/4G (P = 0.01) and the prevalence of hypertension (P < 0.0001) are independent risk factors of development of type 2 diabetic nephropathy. CONCLUSIONS These results suggest that the PAI-1 4G/4G genotype is associated with an increased risk for type 2 diabetic nephropathy in Chinese patients, which is an independent risk factor for the development of nephropathy. The PAI-1 4G/4G genotype also exhibits a synergistic effect with the ACE D allele on development of diabetic nephropathy.
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Affiliation(s)
- T Y Wong
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, The Prince of Wales Hospital, Shatin, Hong Kong
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Hassell P, Klein-Parker H, Worth A, Poon P. Radial sclerosing lesions of the breast: mammographic and pathologic correlation. Can Assoc Radiol J 1999; 50:370-5. [PMID: 10659059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
OBJECTIVE The purpose of this study was to define the mammographic appearance of 96 pathologically proven radial sclerosing lesions (RSLs) and to determine the frequency of association with malignancy in and around the lesions. METHODS Ninety-three patients with 96 RSLs were identified from the pathology files of the BC Cancer Agency, and the reasons for biopsy were obtained. All preoperative mammograms were reviewed, and the RSLs were categorized as classic (typical), non-classic (atypical), or incidental. The histopathologic results were retrospectively examined for atypia, ductal carcinoma in situ (DCIS) and invasive carcinoma. RESULTS In 67 of the 96 biopsies, the RSL was the primary mammographic abnormality that led to biopsy. In this group, 17 cases (25.4%) contained atypia, 17 (25.4%) DCIS, and 4 (6%) invasive carcinoma. Nineteen of these RSLs presented as mass-like opacities that mimicked carcinoma. No single mammographic feature consistently predicted premalignant or malignant lesions. In the remaining 29 patients, biopsy was carried out because of pleomorphic calcifications or masses, and RSLs were found incidentally in specimens. These specimens included 4 cases (13.8%) of atypia, and 1 case (3.4%) of DCIS. CONCLUSION Of the 67 mammographically detected RSLs, only 48 (71.6%) had a typical mammographic appearance. We found a significant amount of atypia (25.4%) and malignancy (25.4% DCIS and 6% invasive carcinoma) in mammographically detected RSLs. Because of the lack of predictable radiological features, adequate open surgical biopsy is recommended for all focal abnormalities in which a RSL is a possible diagnosis.
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Affiliation(s)
- P Hassell
- BC Cancer Agency-Diagnostic Imaging, Vancouver Cancer Centre, BC.
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Affiliation(s)
- S Hawkyard
- Department of Urology, Scarborough Hospital, North Yorkshire, UK
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30
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Zhong N, Ju W, Xu W, Ye L, Shen Y, Wu G, Chen SH, Jin R, Hu XF, Yang A, Liu X, Poon P, Pang C, Zheng Y, Song L, Zhao P, Fu B, Gu H, Brown WT. Frequency of the fragile X syndrome in Chinese mentally retarded populations is similar to that in Caucasians. Am J Med Genet 1999; 84:191-4. [PMID: 10331588 DOI: 10.1002/(sici)1096-8628(19990528)84:3<191::aid-ajmg3>3.0.co;2-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Fragile X syndrome is recognized as the most common inherited cause of mental retardation in western countries. The prevalence of the fragile X syndrome in Asian populations is uncertain. We report a multi-institutional collaborative study of molecular screening for the fragile X syndrome from 1,127 Chinese mentally retarded (MR) individuals. We found that 2.8% of the Chinese MR population screened by DNA analysis had the fragile X full mutation. Our screening indicated that the fragile X syndrome prevalence was very close to that of Caucasian subjects. In addition, we found that 62.5% of fragile X chromosomes had a single haplotype for DXS548-FRAXAC1 (21-18 repeats) which was present in only 9.7% of controls. This unique distribution of microsatellite markers flanking the FMR1 CGG repeats suggests that the fragile X syndrome in Chinese populations, as in the Caucasian, may also be derived from founder chromosomes.
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Affiliation(s)
- N Zhong
- Department of Human Genetics, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314, USA.
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Abstract
Two simple experiments reveal that the ease with which an action is performed by the neuromuscular-skeletal system determines the attentional resources devoted to the movement. Participants were required to perform a primary task, consisting of rhythmic flexion and extension movements of the index finger, while being paced by an auditory metronome, in one of two modes of coordination: flex on the beat or extend on the beat. Using a classical dual-task methodology, we demonstrated that the time taken to react to an unpredictable visual probe stimulus (the secondary task) by means of a pedal response was greater when the extension phase of the finger movement sequence was made on the beat of the metronome than when the flexion phase was coordinated with the beat. In a second experiment, the posture of the wrist was manipulated in order to alter the operating lengths of muscles that flex and extend the index finger. The attentional demands of maintaining the extend-on-the-beat pattern of coordination were altered in a systematic fashion by changes in wrist posture, even though the effector used to respond to the visual probe stimulus was unaffected.
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Affiliation(s)
- R G Carson
- Department of Human Movement Studies, University of Queensland, Brisbane, Australia.
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32
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Mjaavatten O, Levings C, Poon P. Erratum to “Variation in the fatty acid composition of juvenile chinook and coho salmon from Fraser river estuary determined by multivariate analysis; role of environment and genetic origon” [Comp Biochem Physiol 120B (1998) 291–309]. Comp Biochem Physiol B Biochem Mol Biol 1999. [DOI: 10.1016/s0305-0491(99)00035-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Abstract
Hemolin, an insect immunoglobulin superfamily member, is a lipopolysaccharide-binding immune protein induced during bacterial infection. The 3.1 angstrom crystal structure reveals a bound phosphate and patches of positive charge, which may represent the lipopolysaccharide binding site, and a new and unexpected arrangement of four immunoglobulin-like domains forming a horseshoe. Sequence analysis and analytical ultracentrifugation suggest that the domain arrangement is a feature of the L1 family of neural cell adhesion molecules related to hemolin. These results are relevant to interpretation of human L1 mutations in neurological diseases and suggest a domain swapping model for how L1 family proteins mediate homophilic adhesion.
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Affiliation(s)
- X D Su
- Division of Biology 156-29 and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA
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34
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Lee YT, Sung JJ, Poon P, Lai KN, Li PK. Association of HLA class-II genes and anti-neutrophil cytoplasmic antibodies in Chinese patients with inflammatory bowel disease. Scand J Gastroenterol 1998; 33:623-7. [PMID: 9669635 DOI: 10.1080/00365529850171909] [Citation(s) in RCA: 14] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Inflammatory bowel disease is common in the West but rare in China. The genetic factor predisposing to the disease is unclear. Ulcerative colitis (UC) is found to be associated with HLA DR2 alleles in the West. Subgroups of UC patients have been further defined by the presence of anti-neutrophil cytoplasmic antibodies (ANCA). METHODS We attempted to define the HLA class-II genes (DRbeta, DQalpha, DQbeta) and their relationship with ANCA in southern Chinese patients with UC. Patients were tested for class-II genes by restriction fragment length polymorphism and polymerase chain reactions. The indirect immunofluorescence test was used to detect ANCA in the sera. Ethnically matched normal controls were used for comparison. RESULTS In ANCA-positive UC patients (n = 18) there was a strong association with HLA-DQalpha1c allele (P < 0.0001) when compared with controls (n = 104). This association was not found in ANCA-negative UC patients (n = 10) (P = 0.21). CONCLUSIONS In Chinese UC patients positive ANCA is associated with the HLA-DQalpha1c allele, which is not the case in Caucasian patients.
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Affiliation(s)
- Y T Lee
- Dept. of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin
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35
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Millson CE, Charles K, Poon P, Macfie J, Mitchell CJ. A prospective study of serum pancreatic elastase-1 in the diagnosis and assessment of acute pancreatitis. Scand J Gastroenterol 1998; 33:664-8. [PMID: 9669641 DOI: 10.1080/00365529850171963] [Citation(s) in RCA: 22] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND Serum amylase gives a poor estimate of both the true incidence and the severity of acute pancreatitis (AP). METHODS We evaluated serum pancreatic elastase-1 (PE-1) prospectively in 567 patients in whom AP was suspected. In established AP, severity was assessed using the Glasgow Criteria, and C-reactive protein, amylase, and serum PE-1 were evaluated over 5 days. RESULTS The sensitivity, specificity, and diagnostic efficiency of serum PE-1 were 0.66, 0.85, and 0.84, respectively. The diagnostic accuracy of serum PE-1 was 0.80, and that of amylase 0.97. Serum PE-1 did not correlate with disease severity or the development of complications, but it fell more slowly than the serum amylase in the week after admission. CONCLUSIONS The serum PE-1 level correlated closely with the serum amylase but conferred no benefit as a diagnostic test, nor did it provide further prognostic information.
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Affiliation(s)
- C E Millson
- The Combined Gastroenterology Service, Scarborough Hospital, Yorkshire, UK
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36
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O'Boyle CJ, MacFie J, Dave K, Sagar PS, Poon P, Mitchell CJ. Alterations in intestinal barrier function do not predispose to translocation of enteric bacteria in gastroenterologic patients. Nutrition 1998; 14:358-62. [PMID: 9591307 DOI: 10.1016/s0899-9007(97)00488-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Bacterial translocation from the intestinal lumen has been demonstrated in humans. Three mechanisms have been suggested to explain the phenomenon: altered intestinal barrier function, bacterial overgrowth, and impaired host defense. The aim of this study was to determine whether changes in intestinal barrier function assessed by measurement of intestinal permeability and morphology were associated with alteration in bacterial translocation. Intestinal permeability was assessed in 43 patients by the lactulose/L-rhamnose test with a 5-h urine collection. Mucosal atrophy was assessed from the villus height-to-mucosal thickness ratio in small-bowel biopsies. Bacterial translocation was determined by microbiologic analysis of harvested mesenteric lymph nodes. No significant differences were apparent in the incidence of bacterial translocation in patients with normal permeability (5 [23%] of 22 patients translocated) compared with patients with increased permeability (4 [19%] of 21 patients translocated). Similarly, no correlation was apparent between the incidence of bacterial translocation and the index of villus atrophy. The degree of villus atrophy failed to correlate with gastrointestinal permeability. These data suggest that the incidence of bacterial translocation is not related to increased intestinal permeability or mucosal atrophy.
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Affiliation(s)
- C J O'Boyle
- Combined Gastroenterology Unit, Scarborough Hospital, United Kingdom
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37
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Affiliation(s)
- K Wong
- Department of Diagnostic Imaging, British Columbia Cancer Agency, Vancouver, Canada
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38
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Abstract
T-cell receptor (TCR) proteins recognize a complex of an antigen-derived peptide bound to the cell surface products of the major histocompatibility complex (MHC) that could be of importance in the immunopathogenesis of IgA nephropathy (IgAN). Previous studies found no difference on TCR constant beta chain gene frequencies in IgAN compared with control. Yet no study on the TCR alpha gene in IgAN was reported. We studied the TCR C alpha gene polymorphisms by restriction fragment length polymorphism (RFLP) in 53 patients with IgAN and in comparison with 67 healthy controls. The patients were also classified into different histopathological grading (I, II, and III with increasing histological severity) and renal functions. The extracted DNA were digested with Taq I enzymes and probed with a full-length TCR-alpha cDNA clone p1.2alpha probe. A 7-kb C-alpha Taq 1 fragment is found in 32 of 53 patients (60.3%) compared with 26 of 67 controls (38.8%) (P < 0.05). There was no association of any polymorphic fragment, including the 7-kb fragment, with either the histological grading or renal function. It is concluded that the TCR C-alpha gene is associated with IgAN but not with the prognosis of the disease.
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Affiliation(s)
- P K Li
- Department of Medicine, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin.
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39
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Lai KN, Lai KB, Szeto CC, Ho KK, Poon P, Lam CW, Leung JC. Dialysate cell population and cancer antigen 125 in stable continuous ambulatory peritoneal dialysis patients: their relationship with transport parameters. Am J Kidney Dis 1997; 29:699-705. [PMID: 9159303 DOI: 10.1016/s0272-6386(97)90122-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [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: 02/04/2023]
Abstract
We investigated the total cell count and cell population of the overnight peritoneal dialysis effluent (PDE) by flow cytometry in 76 stable continuous ambulatory peritoneal dialysis (CAPD) patients. The mean percentage of mesothelial cells and macrophages was 4.4% and 57%, respectively. A higher percentage of dead cells among the mesothelial cells compared with other cell populations in the PDE was observed. Peritoneal transport properties were studied in every patient by determining the dialysate to plasma ratio of creatinine concentration (D/P) at the fourth hour of the peritoneal equilibration test, and the mass transfer area coefficient of creatinine (MTACCr) or glucose. Cancer antigen 125 (CA125), suggested as a bulk marker for the mesothelial mass in stable peritoneal dialysis patients, was determined in the PDE. No correlation was demonstrated between CA125 and the number of mesothelial cells, lymphocytes, or macrophages in the PDE. A significant correlation was observed between CA125 and different parameters of peritoneal transport (D/P and MTACCr). On the contrary, neither the history of peritonitis nor the duration of CAPD appeared to affect the CA125 concentration in the PDE. The lack of correlation between CA125 in the PDE and the duration of CAPD may be related to the early loss of peritoneal transport properties as a result of the use of hypertonic dialysate in the majority of our patients with small-volume CAPD (3 x 2 L daily exchange). Our findings suggest that CA125 may not necessarily correlate well with the number of mesothelial cells in PDE. In patients with vanishing of the mesothelial layer, the measurement of CA125 (as a bulk marker for the mesothelial mass in the peritoneum) may reflect the change of peritoneal transport properties.
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Affiliation(s)
- K N Lai
- Department of Medicine, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin
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40
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Zhong N, Ju W, Curley D, Wang D, Pietrofesa J, Wu G, Shen Y, Pang C, Poon P, Liu X, Gou S, Kajanoja E, Ryynänen M, Dobkin C, Brown WT. A survey of FRAXE allele sizes in three populations. Am J Med Genet 1996; 64:415-9. [PMID: 8844095 DOI: 10.1002/(sici)1096-8628(19960809)64:2<415::aid-ajmg36>3.0.co;2-g] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
FRAXE is a fragile site located at Xq27-8, which contains polymorphic triplet GCC repeats associated with a CpG island. Similar to FRAXA, expansion of the GCC repeats results in an abnormal methylation of the CpG island and is associated with a mild mental retardation syndrome (FRAXE-MR). We surveyed the GCC repeat alleles of FRAXE from 3 populations. A total of 665 X chromosomes including 416 from a New York Euro-American sample (259 normal and 157 with FRAXA mutations), 157 from a Chinese sample (144 normal and 13 FRAXA), and 92 from a Finnish sample (56 normal and 36 FRAXA) were analyzed by polymerase chain reaction. Twenty-seven alleles, ranging from 4 to 39 GCC repeats, were observed. The modal repeat number was 16 in the New York and Finnish samples and accounted for 24% of all the chromosomes tested (162/665). The modal repeat number in the Chinese sample was 18. A founder effect for FRAXA was suggested among the Finnish FRAXA samples in that 75% had the FRAXE 16 repeat allele versus only 30% of controls. Sequencing of the FRAXE region showed no imperfections within the GCC repeat region, such as those commonly seen in FRAXA. The smaller size and limited range of repeats and the lack of imperfections suggests the molecular mechanisms underlying FRAXE triplet mutations may be different from those underlying FRAXA.
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Affiliation(s)
- N Zhong
- Department of Human Genetics, New York State Institute for Basic Research for Developmental Disabilities, Staten Island 10314, USA
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41
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Poon P, Smith JF. The short Synacthen and insulin stress tests in the assessment of the hypothalamic-pituitary-adrenal axis. Clin Endocrinol (Oxf) 1996; 45:245. [PMID: 8881462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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42
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Abstract
The aim of the paper is to determine the speed of the neurological response to cerebral artery occlusion by monitoring transient changes in somatosensory evoked potentials (SEPs). SEPs, continuously monitored during temporary clipping of the middle cerebral artery (MCA) in anaesthetised cats, are analysed. The SEP signals are modelled by a quasi-periodic Fourier series, the coefficients of which are estimated with the aid of two adaptive least squares estimation algorithms. The energy levels at various harmonics throughout the protocol are obtained directly from the filter weights. Noise covariance is estimated from pre-stimulus recording, and the adaptation rate of the algorithm is adjusted sweep-by-sweep to accommodate transient changes in the pre-stimulus noise level. After the occlusion, a significant decrease (p < 0.05) in SEP amplitude is observed. The change in latency is not statistically significant (p approximately equal to 0.5). The spectral trends show a sudden decline in energy at all harmonics immediately following occlusion, although when the amplifier bandwidth is changed to 5-1500 Hz (from an initial setting of 30-1500 Hz), the fundamental frequency component of the SEP signal shows the greatest responsiveness to injury. The average time constant of the decline in amplitude resulting from MCA occlusion is only 10.6 +/- 4.0 s. It is concluded that rapid detection of cerebral artery occlusion and ischaemia may be feasible by continuously monitoring SEP signals and analysing transient changes in time and frequency domains.
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Affiliation(s)
- P Poon
- Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
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Abstract
Even with thirty years of academic experience under his belt, nothing could have prepared the medical school department chairman for the unexpected and protracted course of events that would follow his allegations of scientific misconduct against an associate professor in his department. In this actual case of scientific misconduct whistleblowing, the university allowed the accused professor to resign, but the chairman persisted in seeking a full investigation of the matter. Under the direction of the Office of Scientific Integrity (OSI) of the Department of Health and Human Services (DHHS), the institution eventually reopened the investigation, and concluded that the accused professor had fabricated and falsified data, and had plagiarized the unpublished method of other investigators. Thereafter, the professor agreed to a voluntary exclusion from receiving federal funds for a period of three years.Despite the fact that the chairman's allegations proved true, his involvement as a “whistleblower” entailed consequences that censured rather than encouraged his behavior.
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Sagar P, Wai D, Poon P, Macfie J, Mitchell C. The effects of major abdominal surgery, enteral and parenteral nutrition on pancreatic function and morphology. Clin Nutr 1994; 13:314-8. [PMID: 16843405 DOI: 10.1016/0261-5614(94)90055-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/1994] [Accepted: 05/02/1994] [Indexed: 10/26/2022]
Abstract
The effects of major abdominal surgery and nutritional support upon pancreatic function and morphology were studied in similar groups of patients who underwent major abdominal surgery (n = 18), received parenteral nutritional support (n = 18) or received enteral nutritional support (n = 16). The exocrine function of the pancreas was measured by means of an oral pancreatic function test (using 1 g of N-benzoyl-L-tyrosyl para-aminobenzoic acid) with measurement of serum para-aminobenzoic acid at 3 h and the Pancreatic Excretion Index. Pancreatic morphology was assessed by real time ultrasound and a pancreatic size index was calculated (maximum diameter of head x body). Serial measurements of function and morphology were carried out in each patient at entry into the study and at 7 and 14 days after operation or start of nutritional support. Serum PABA levels were similar in the 3 groups at the start of the study. Although the levels remained unchanged in the enteral and parenteral groups, a significant and progressive decrease was observed in the surgical group (serum PABA = 27.5 nmol/l (24.0-30.6) before operation, 10.5 nmol/l (5.5-13.4) 14 days after operation, P < 0.01). No significant changes in pancreatic size were seen. Parenteral and enteral nutrition preserves pancreatic exocrine function. A dramatic reduction in pancreatic exocrine function is seen after major abdominal surgery.
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Affiliation(s)
- P Sagar
- Scarborough Hospital, Scalby Road, Scarborough, North Yorkshire, UK
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45
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Chan TY, Poon P, Pang J, Swaminathan R, Chan CH, Nisar M, Williams CS, Davies PD. A study of calcium and vitamin D metabolism in Chinese patients with pulmonary tuberculosis. J Trop Med Hyg 1994; 97:26-30. [PMID: 8107170] [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: 01/28/2023]
Abstract
Hypercalcaemia can occur in patients with tuberculosis. To further characterize the calcium and vitamin D metabolism in this disorder, serum calcium, 25(OH)D, 1,25(OH)2D and parathyroid hormone and the interrelationships between serum calcium, 25(OH)D and 1,25(OH)2D were compared in 24 untreated Chinese patients with culture-positive pulmonary tuberculosis and 24 age and sex-matched controls in Hong Kong. Albumin adjusted serum calcium was significantly higher in patients (2.33 +/- 0.07 compared with 2.20 +/- 0.09 mmol l-1, P < 0.001), despite a lower calcium intake (426 +/- 208 compared with 564 +/- 335 mg day-1). No significant group difference was found in serum 25(OH)D or 1,25(OH)2D concentrations. There was a positive correlation between serum 25(OH)D and 1,25(OH)2D concentrations in the patient group (r = 0.50, P < 0.02), but a negative one in the control group (r = -0.48, P < 0.05). Serum parathyroid hormone was significantly lower in patients (20.9 +/- 8.5 compared with 38.2 +/- 14.5 pmol l-1, P < 0.001). In the patient group, no correlation between the radiographic extent of disease and serum calcium or 1,25(OH)2D concentrations was seen. Our findings confirmed that serum calcium is raised in tuberculosis but the effect may be reduced by a low calcium intake and a low parathyroid hormone level. Although the calcium and vitamin D metabolism appeared to be altered in tuberculosis, no direct relationship between serum calcium and 1,25(OH)2D, was found.
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Affiliation(s)
- T Y Chan
- Department of Clinical Pharmacology, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT
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46
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Abstract
We report gadolinium-enhancing nerve root lesions in a 52-year-old man with typical Guillain-Barré syndrome (GBS). This enhancement correlates well with the perineurial inflammatory and demyelinating processes known to characterize GBS and other inflammatory neuropathies. MRI should enable further exploration of patterns of disease in GBS and, with further study, perhaps assist in evaluating therapy.
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Affiliation(s)
- J R Perry
- Division of Neurology, St. Michael's Hospital, Toronto, Ontario, Canada
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47
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Chan AY, Poon P, Chan EL, Fung SL, Swaminathan R. The effect of high sodium intake on bone mineral content in rats fed a normal calcium or a low calcium diet. Osteoporos Int 1993; 3:341-4. [PMID: 8292846 DOI: 10.1007/bf01637321] [Citation(s) in RCA: 16] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The effect of high sodium intake on bone mineral content of rats fed a normal (0.6% Ca) or a low (0.02% Ca) calcium diet was studied. Rats on a normal calcium diet given 1.8% sodium chloride to drink showed persistent and significant hypercalciuria and subnormal bone mineral content. Total calcium content of femur was significantly lower after 4 months (p < 0.02) and 12 months (p < 0.001). In rats maintained on a low calcium diet (0.02% Ca), a high sodium diet for 8 weeks caused a significant loss of calcium in bone similar to that seen in animals fed a normal calcium diet for 4 months. We conclude that high sodium intake reduces bone mineral content, especially if the diet is low in calcium.
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Affiliation(s)
- A Y Chan
- Department of Chemical Pathology, Prince of Wales Hospital, Shatin NT, Hong Kong, UK
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48
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Allen KR, Hamilton AD, Bodansky HJ, Poon P. Prevalence of haemoglobin variants in a diabetic population and their effect on glycated haemoglobin measurement. Ann Clin Biochem 1992; 29 ( Pt 4):426-9. [PMID: 1642450 DOI: 10.1177/000456329202900410] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [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: 12/28/2022]
Abstract
The measurement of glycated haemoglobin (glycated Hb) by automated high pressure liquid chromatography enabled the prevalence of haemoglobin variants (Hb variant) to be determined in a large diabetic population within Leeds, UK. There were 16 patients showing a Hb variant amongst a total of 5300 diabetics, the majority of the variants being HbA/S traits. There were also 13 patients showing a slightly raised HbF in the range of 2% to 5%. A multi-centre study was carried out by distributing blood specimens from some of the patients with Hb traits. Significant differences in the percentage of glycated Hb were observed relating to the methodology used. However, glycated Hb is used to monitor glycaemic control and laboratories must be aware of Hb variant interferences on their methods. Also, screening for Hb variants should be considered for the at risk groups of diabetic patients.
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Affiliation(s)
- K R Allen
- Pathology Department, Wharfedale General Hospital, Otley, West Yorkshire, UK
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Affiliation(s)
- H Wilkinson
- Department of Biochemistry, York District Hospital, UK
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Marshall RJ, Gee R, Israel M, Neave D, Edwards F, Dumble J, Wong S, Chan C, Patel R, Poon P. The use of alternative therapies by Auckland general practitioners. N Z Med J 1990; 103:213-5. [PMID: 2342693] [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: 12/31/2022]
Abstract
A survey of Auckland general practitioners was undertaken to explore their use of, and attitudes to, alternative medicines. Three hundred and seventy randomly selected doctors, from a total of about 700 doctors practising in Auckland, were posted questionnaires. Of 249 respondents, 75 (30%) practised one or more forms of alternative medicine. Acupuncture was the therapy most commonly used. Musculoskeletal disorders and chronic pain syndromes were the most frequently treated conditions. A total of 171 (68.7%) respondents referred patients to one or more forms of alternative treatment, and only 56 (32.7%) of these felt it necessary that the person referred to be medically qualified. Younger doctors were more inclined to refer and the most commonly cited reason for referral was failure of conventional medicine.
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Affiliation(s)
- R J Marshall
- Department of Community Health, University of Auckland School of Medicine
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