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Ma Y, Cai H, Smith J, Chu CH, Mercer SE, Boehm S, Mcdonald I, Zinker B, Cheng D. Evaluation of antisense oligonucleotide therapy targeting Hsd17b13 in a fibrosis mice model. J Lipid Res 2024; 65:100514. [PMID: 38309418 PMCID: PMC10911849 DOI: 10.1016/j.jlr.2024.100514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/05/2024] Open
Abstract
Human genetic evidence suggests a protective role of loss-of-function variants in 17-beta hydroxysteroid dehydrogenase 13 (HSD17B13) for liver fibrotic diseases. Although there is limited preclinical experimental data on Hsd17b13 antisense oligonucleotide (ASO) or siRNA in a fibrosis model, several ASO and siRNA approaches are being tested clinically as potential therapies for nonalcoholic steatohepatitis (NASH). The aim of this study was to assess the therapeutic potential of Hsd17b13 ASO in a preclinical advanced NASH-like hepatic fibrosis in vivo model. In vitro testing on primary hepatocytes demonstrated that Hsd17b13 ASO exhibited strong efficacy and specificity for knockdown of the Hsd17b13 gene. In choline-deficient, L-amino acid-defined, HFD (CDAHFD)-induced steatotic and fibrotic mice, therapeutic administration of Hsd17b13 ASO resulted in a significant and dose-dependent reduction of hepatic Hsd17b13 gene expression. The CDAHFD group exhibited considerably elevated liver enzyme levels, hepatic steatosis score, hepatic fibrosis, and increased fibrotic and inflammatory gene expression, indicating an advanced NASH-like hepatic fibrosis phenotype. Although Hsd17b13 ASO therapy significantly affected hepatic steatosis, it had no effect on hepatic fibrosis. Our findings demonstrate, for the first time, that Hsd17b13 ASO effectively suppressed Hsd17b13 gene expression both in vitro and in vivo, and had a modulatory effect on hepatic steatosis in mice, but did not affect fibrosis in the CDAHFD mouse model of NASH.
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Affiliation(s)
- Yanling Ma
- Bristol-Myers Squibb Company, Lawrence Township, NJ, USA.
| | - Hong Cai
- Bristol-Myers Squibb Company, Lawrence Township, NJ, USA
| | - Julia Smith
- Bristol-Myers Squibb Company, Lawrence Township, NJ, USA
| | | | | | | | - Ivar Mcdonald
- Bristol-Myers Squibb Company, Lawrence Township, NJ, USA
| | - Bradley Zinker
- Bristol-Myers Squibb Company, Lawrence Township, NJ, USA
| | - Dong Cheng
- Bristol-Myers Squibb Company, Lawrence Township, NJ, USA.
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2
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Meng W, Brigance R, Mignone J, Negash L, Zhao G, Ahmad S, Wang W, Moore F, Ye XY, Sun JH, Mathur A, Li YX, Azzara A, Ma Z, Chu CH, Cullen MJ, Rooney S, Harvey S, Kopcho L, Abell L, O'Malley K, Keim W, Dierks EA, Chang S, Foster KA, Harden D, Dabros M, Goti V, De Oliveira C, Krishna G, Pelleymounter MA, Whaley J, Robl JA, Cheng D, Devasthale P. Discovery of 12 (BMS-986172) as a Highly Potent MGAT2 Inhibitor that Achieved Targeted Efficacious Exposures at a Low Human Dose for the Treatment of Metabolic Disorders. J Med Chem 2023; 66:13135-13147. [PMID: 37724542 DOI: 10.1021/acs.jmedchem.3c01147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
A series of dihydropyridinone (DHP) compounds was prepared and evaluated for MGAT2 activity. The efforts led to the identification of novel tetrazolones with potent MGAT2 inhibitory activity and favorable in vitro profiles. Further tests of select analogues in mouse models revealed significant reduction in food intake and body weight. Subsequent studies in MGAT2 knockout mice with the lead candidate 12 (BMS-986172) showed on-target- and mechanism-based pharmacology. Moreover, its favorable pharmacokinetic (PK) profile and the lack of species variability in the glucuronidation potential resulted in a greater confidence level in the projection of a low dose for achieving targeted efficacious exposures in humans. Consistent with these projections, PK data from a phase 1 trial confirmed that targeted efficacious exposures could be achieved at a low dose in humans, which supported compound 12 as our second and potentially superior development candidate for the treatment of various metabolic disorders.
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3
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Moore F, Wang W, Zhao G, Mignone J, Meng W, Chu CH, Ma Z, Azzara A, Cullen MJ, Pelleymounter MA, Appiah K, Cvijic ME, Dierks E, Chang S, Foster K, Kopcho L, O'Malley K, Li YX, Khandelwal P, Whaley JM, Mathur A, Hou X, Wu DR, Robl JA, Cheng D, Devasthale P. Discovery of novel pyridinones as MGAT2 inhibitors for the treatment of metabolic disorders. Bioorg Med Chem Lett 2023; 91:129362. [PMID: 37295614 DOI: 10.1016/j.bmcl.2023.129362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 01/13/2023] [Accepted: 06/01/2023] [Indexed: 06/12/2023]
Abstract
Inhibition of monoacylglycerol transferase 2 (MGAT2) has recently emerged as a potential therapeutic strategy for the treatment of metabolic diseases such as obesity, diabetes and non-alcoholic steatohepatitis (NASH). Metabolism studies with our clinical lead (1) suggested variability in in vitro glucuronidation rates in liver microsomes across species, which made projection of human doses challenging. In addition, the observation of deconjugation of the C3-C4 double bond in the dihydropyridinone ring of 1 in solution had the potential to complicate its clinical development. This report describes our lead optimization efforts in a novel pyridinone series, exemplified by compound 33, which successfully addressed both of these potential issues.
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Affiliation(s)
- Fang Moore
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Wei Wang
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Guohua Zhao
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - James Mignone
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Wei Meng
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Ching-Hsuen Chu
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Zhengping Ma
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Anthony Azzara
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Mary Jane Cullen
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Mary Ann Pelleymounter
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Kingsley Appiah
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Mary Ellen Cvijic
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Elizabeth Dierks
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Shu Chang
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Kimberly Foster
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Lisa Kopcho
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Kevin O'Malley
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Yi-Xin Li
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Purnima Khandelwal
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Jean M Whaley
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Arvind Mathur
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Xiaoping Hou
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Dauh-Rurng Wu
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Jeffrey A Robl
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Dong Cheng
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States
| | - Pratik Devasthale
- Bristol Myers Squibb Research & Development, P.O. Box 4000, Princeton, NJ, 08543, United States.
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4
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Chu CH, Mei ML, Wu WKK. Novel dentotropic antimicrobial peptide to prevent dental caries: abridged secondary publication. Hong Kong Med J 2023; 29 Suppl 1:34-38. [PMID: 36919218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Affiliation(s)
- C H Chu
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - M L Mei
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China.,Faculty of Dentistry, University of Otago, New Zealand
| | - W K K Wu
- Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Hong Kong SAR, China
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5
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Cheng D, Zinker BA, Luo Y, Shipkova P, De Oliveira CH, Krishna G, Brown EA, Boehm SL, Tirucherai GS, Gu H, Ma Z, Chu CH, Onorato JM, Kopcho LM, Ammar R, Smith J, Devasthale P, Lawrence RM, Stryker SA, Dierks EA, Azzara AV, Carayannopoulos L, Charles ED, Lentz KA, Gordon DA. MGAT2 inhibitor decreases liver fibrosis and inflammation in murine NASH models and reduces body weight in human adults with obesity. Cell Metab 2022; 34:1732-1748.e5. [PMID: 36323235 DOI: 10.1016/j.cmet.2022.10.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 06/14/2022] [Accepted: 10/12/2022] [Indexed: 11/07/2022]
Abstract
Monoacylglycerol acyltransferase 2 (MGAT2) is an important enzyme highly expressed in the human small intestine and liver for the regulation of triglyceride absorption and homeostasis. We report that treatment with BMS-963272, a potent and selective MGAT2 inhibitor, decreased inflammation and fibrosis in CDAHFD and STAM, two murine nonalcoholic steatohepatitis (NASH) models. In high-fat-diet-treated cynomolgus monkeys, in contrast to a selective diacylglycerol acyltransferase 1 (DGAT1) inhibitor, BMS-963272 did not cause diarrhea. In a Phase 1 multiple-dose trial of healthy human adults with obesity (NCT04116632), BMS-963272 was safe and well tolerated with no treatment discontinuations due to adverse events. Consistent with the findings in rodent models, BMS-963272 elevated plasma long-chain dicarboxylic acid, indicating robust pharmacodynamic biomarker modulation; increased gut hormones GLP-1 and PYY; and decreased body weight in human subjects. These data suggest MGAT2 inhibition is a promising therapeutic opportunity for NASH, a disease with high unmet medical needs.
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Affiliation(s)
- Dong Cheng
- Departments of Discovery Biology Cardiovascular and Fibrosis, Bristol Myers Squibb, Princeton, NJ 08543, USA.
| | - Bradley A Zinker
- Departments of Discovery Biology Cardiovascular and Fibrosis, Bristol Myers Squibb, Princeton, NJ 08543, USA
| | - Yi Luo
- Translational Medicine, Bristol Myers Squibb, Lawrenceville, NJ 08543, USA
| | - Petia Shipkova
- Pharmaceutical Candidate Optimization, Bristol Myers Squibb, Princeton, NJ 08543, USA
| | | | - Gopal Krishna
- ICF Early Clinical Development, Bristol Myers Squibb, Summit, NJ 07901, USA
| | - Elizabeth A Brown
- Translational Bioinformatics, Bristol Myers Squibb, Princeton, NJ 08543, USA
| | - Stephanie L Boehm
- Departments of Discovery Biology Cardiovascular and Fibrosis, Bristol Myers Squibb, Princeton, NJ 08543, USA
| | | | - Huidong Gu
- Translational Medicine, Bristol Myers Squibb, Lawrenceville, NJ 08543, USA
| | - Zhengping Ma
- Departments of Discovery Biology Cardiovascular and Fibrosis, Bristol Myers Squibb, Princeton, NJ 08543, USA
| | - Ching-Hsuen Chu
- Departments of Discovery Biology Cardiovascular and Fibrosis, Bristol Myers Squibb, Princeton, NJ 08543, USA
| | - Joelle M Onorato
- Pharmaceutical Candidate Optimization, Bristol Myers Squibb, Princeton, NJ 08543, USA
| | - Lisa M Kopcho
- Leads Discovery and Optimization, Bristol Myers Squibb, Princeton, NJ 08543, USA
| | - Ron Ammar
- Translational Bioinformatics, Bristol Myers Squibb, Princeton, NJ 08543, USA
| | - Julia Smith
- Departments of Discovery Biology Cardiovascular and Fibrosis, Bristol Myers Squibb, Princeton, NJ 08543, USA
| | - Pratik Devasthale
- Small Molecule Drug Discovery, Bristol Myers Squibb, Princeton, NJ 08543, USA
| | - R Michael Lawrence
- Small Molecule Drug Discovery, Bristol Myers Squibb, Princeton, NJ 08543, USA
| | - Steven A Stryker
- Pharmaceutical Candidate Optimization, Bristol Myers Squibb, Princeton, NJ 08543, USA
| | - Elizabeth A Dierks
- Pharmaceutical Candidate Optimization, Bristol Myers Squibb, Princeton, NJ 08543, USA
| | - Anthony V Azzara
- Departments of Discovery Biology Cardiovascular and Fibrosis, Bristol Myers Squibb, Princeton, NJ 08543, USA
| | | | - Edgar D Charles
- Global Drug Development, Bristol Myers Squibb, Lawrenceville, NJ 08543, USA
| | - Kimberley A Lentz
- Pharmaceutical Candidate Optimization, Bristol Myers Squibb, Princeton, NJ 08543, USA
| | - David A Gordon
- Departments of Discovery Biology Cardiovascular and Fibrosis, Bristol Myers Squibb, Princeton, NJ 08543, USA
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6
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Cheng PTW, Kaltenbach RF, Zhang H, Shi J, Tao S, Li J, Kennedy LJ, Walker SJ, Shi Y, Wang Y, Dhanusu S, Reddigunta R, Kumaravel S, Jusuf S, Smith D, Krishnananthan S, Li J, Wang T, Heiry R, Sum CS, Kalinowski SS, Hung CP, Chu CH, Azzara AV, Ziegler M, Burns L, Zinker BA, Boehm S, Taylor J, Sapuppo J, Mosure K, Everlof G, Guarino V, Zhang L, Yang Y, Ruan Q, Xu C, Apedo A, Traeger SC, Cvijic ME, Lentz KA, Tirucherai G, Sivaraman L, Robl J, Ellsworth BA, Rosen G, Gordon DA, Soars MG, Gill M, Murphy BJ. Discovery of an Oxycyclohexyl Acid Lysophosphatidic Acid Receptor 1 (LPA 1) Antagonist BMS-986278 for the Treatment of Pulmonary Fibrotic Diseases. J Med Chem 2021; 64:15549-15581. [PMID: 34709814 DOI: 10.1021/acs.jmedchem.1c01256] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The oxycyclohexyl acid BMS-986278 (33) is a potent lysophosphatidic acid receptor 1 (LPA1) antagonist, with a human LPA1 Kb of 6.9 nM. The structure-activity relationship (SAR) studies starting from the LPA1 antagonist clinical compound BMS-986020 (1), which culminated in the discovery of 33, are discussed. The detailed in vitro and in vivo preclinical pharmacology profiles of 33, as well as its pharmacokinetics/metabolism profile, are described. On the basis of its in vivo efficacy in rodent chronic lung fibrosis models and excellent overall ADME (absorption, distribution, metabolism, excretion) properties in multiple preclinical species, 33 was advanced into clinical trials, including an ongoing Phase 2 clinical trial in patients with lung fibrosis (NCT04308681).
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Affiliation(s)
- Peter T W Cheng
- Fibrosis Chemistry, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Robert F Kaltenbach
- Fibrosis Chemistry, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Hao Zhang
- Fibrosis Chemistry, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Jun Shi
- Fibrosis Chemistry, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Shiwei Tao
- Fibrosis Chemistry, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Jun Li
- Fibrosis Chemistry, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Lawrence J Kennedy
- Fibrosis Chemistry, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Steven J Walker
- Fibrosis Chemistry, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Yan Shi
- Fibrosis Chemistry, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Ying Wang
- Fibrosis Chemistry, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Suresh Dhanusu
- Biocon-Bristol Myers Squibb Research & Development Center, Bangalore 560099, India
| | - Ramesh Reddigunta
- Biocon-Bristol Myers Squibb Research & Development Center, Bangalore 560099, India
| | - Selvakumar Kumaravel
- Biocon-Bristol Myers Squibb Research & Development Center, Bangalore 560099, India
| | - Sutjano Jusuf
- Computer Aided Drug Design, Molecular Structure & Design, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Daniel Smith
- Discovery Chemistry Synthesis, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Subramaniam Krishnananthan
- Discovery Chemistry Synthesis, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Jianqing Li
- Discovery Chemistry Synthesis, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Cambridge, Massachusetts 02140, United States
| | - Tao Wang
- Lead Evaluation, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Rebekah Heiry
- Lead Evaluation, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Chi Shing Sum
- Lead Evaluation, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Stephen S Kalinowski
- Cardiovascular & Fibrosis Discovery Biology, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Chen-Pin Hung
- Cardiovascular & Fibrosis Discovery Biology, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Ching-Hsuen Chu
- Cardiovascular & Fibrosis Discovery Biology, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Anthony V Azzara
- Cardiovascular & Fibrosis Discovery Biology, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Milinda Ziegler
- Cardiovascular & Fibrosis Discovery Biology, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Lisa Burns
- Cardiovascular & Fibrosis Discovery Biology, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Bradley A Zinker
- Cardiovascular & Fibrosis Discovery Biology, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Stephanie Boehm
- Cardiovascular & Fibrosis Discovery Biology, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Joseph Taylor
- Cardiovascular & Fibrosis Discovery Biology, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Julia Sapuppo
- Cardiovascular & Fibrosis Discovery Biology, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Kathy Mosure
- Metabolism & Pharmacokinetics, Preclinical Candidate Optimization, Research & Early Development, Bristol Myers Squibb Company, Cambridge, Massachusetts 02140, United States
| | - Gerry Everlof
- Pharmaceutics, Preclinical Candidate Optimization, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Victor Guarino
- Metabolism & Pharmacokinetics, Preclinical Candidate Optimization, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Lisa Zhang
- Metabolism & Pharmacokinetics, Preclinical Candidate Optimization, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Yanou Yang
- Biotransformation, Preclinical Candidate Optimization, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Qian Ruan
- Biotransformation, Preclinical Candidate Optimization, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Carrie Xu
- Bioanalytical Chemistry, Preclinical Candidate Optimization, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Atsu Apedo
- Discovery Analytical Sciences, Preclinical Candidate Optimization, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Sarah C Traeger
- Discovery Analytical Sciences, Small Molecule Drug Discovery, Research and Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Mary Ellen Cvijic
- Lead Evaluation, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Kimberley A Lentz
- Metabolism & Pharmacokinetics, Preclinical Candidate Optimization, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Giridhar Tirucherai
- Clinical Pharmacology, Immunology, Cardiovascular and Fibrosis, Research and Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-5326, United States
| | - Lakshmi Sivaraman
- Nonclinical Safety Evaluation, Research & Development, Bristol Myers Squibb Company, New Brunswick, New Jersey 08903-0191, United States
| | - Jeffrey Robl
- Fibrosis Chemistry, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Bruce A Ellsworth
- Fibrosis Chemistry, Small Molecule Drug Discovery, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Glenn Rosen
- Cardiovascular & Fibrosis Discovery Biology, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - David A Gordon
- Cardiovascular & Fibrosis Discovery Biology, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Matthew G Soars
- Metabolism & Pharmacokinetics, Preclinical Candidate Optimization, Research & Early Development, Bristol Myers Squibb Company, Cambridge, Massachusetts 02140, United States
| | - Michael Gill
- Discovery Toxicology, Preclinical Candidate Optimization, Research and Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
| | - Brian J Murphy
- Cardiovascular & Fibrosis Discovery Biology, Research & Early Development, Bristol Myers Squibb Company, Princeton, New Jersey 08543-4000, United States
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7
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Turdi H, Chao H, Hangeland JJ, Ahmad S, Meng W, Brigance R, Zhao G, Wang W, Moore F, Ye XY, Mathur A, Hou X, Kempson J, Wu DR, Li YX, Azzara AV, Ma Z, Chu CH, Chen L, Cullen MJ, Rooney S, Harvey S, Kopcho L, Panemangelor R, Abell L, O'Malley K, Keim WJ, Dierks E, Chang S, Foster K, Apedo A, Harden D, Dabros M, Gao Q, Pelleymounter MA, Whaley JM, Robl JA, Cheng D, Lawrence RM, Devasthale P. Screening Hit to Clinical Candidate: Discovery of BMS-963272, a Potent, Selective MGAT2 Inhibitor for the Treatment of Metabolic Disorders. J Med Chem 2021; 64:14773-14792. [PMID: 34613725 DOI: 10.1021/acs.jmedchem.1c01356] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
MGAT2 inhibition is a potential therapeutic approach for the treatment of metabolic disorders. High-throughput screening of the BMS internal compound collection identified the aryl dihydropyridinone compound 1 (hMGAT2 IC50 = 175 nM) as a hit. Compound 1 had moderate potency against human MGAT2, was inactive vs mouse MGAT2 and had poor microsomal metabolic stability. A novel chemistry route was developed to synthesize aryl dihydropyridinone analogs to explore structure-activity relationship around this hit, leading to the discovery of potent and selective MGAT2 inhibitors 21f, 21s, and 28e that are stable to liver microsomal metabolism. After triaging out 21f due to its inferior in vivo potency, pharmacokinetics, and structure-based liabilities and tetrazole 28e due to its inferior channel liability profile, 21s (BMS-963272) was selected as the clinical candidate following demonstration of on-target weight loss efficacy in the diet-induced obese mouse model and an acceptable safety and tolerability profile in multiple preclinical species.
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8
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Jiang M, Mei ML, Wong M, Chu CH, Lo E. Influence of Silver Diamine Fluoride Treatment on the Microtensile Bond Strength of Glass Ionomer Cement to Sound and Carious Dentin. Oper Dent 2020; 45:E271-E279. [PMID: 32502257 DOI: 10.2341/19-237-l] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2020] [Indexed: 11/23/2022]
Abstract
CLINICAL RELEVANCE This study provides valuable information about the influence of silver diamine fluoride (SDF) treatment on the microtensile bond strength of glass ionomer cement (GIC) to dentin. SUMMARY Objectives: To investigate the influence of silver diamine fluoride (SDF) treatment on the microtensile bond strength (mTBS) of glass ionomer cement (GIC) to sound and artificial carious dentin.Methods: Thirty dentin blocks prepared from 30 noncarious human molars were randomly allocated into either the sound (Gp1) or artificial carious dentin (Gp2) groups. A microbiological method was adopted to create artificial dentin caries lesions in Gp2 specimens. Each dentin block was sectioned into two halves perpendicularly, and each pair of block halves was randomly assigned to two subgroups to receive topical application of SDF (Gp1-SDF, Gp2-SDF) or water as control (Gp1-water, Gp2-water). An encapsulated GIC was bonded to the exposed dentin surfaces 14 days after the SDF/water application. After immersion for 7 days in artificial saliva, the GIC-dentin specimens were sectioned into beams for mTBS testing. Failure mode was examined after the mTBS test.Results: There was no significant difference in the mean mTBS values between the SDF and control subgroups (Gp1-SDF vs Gp1-water, 10.57±1.6 MPa vs 10.20±1.8 MPa; Gp2-SDF vs Gp2-water, 6.14±2.2 MPa vs 5.97±2.3 MPa; paired t-test, p>0.05). However, the mean mTBS value of the sound dentin group was significantly higher than that of the carious dentin group, irrespective of whether SDF was applied prior to GIC bonding (independent t-test, p<0.001). Proportionally more cohesive failures occurred in the sound dentin groups (Gp1-SDF, 48.4%; Gp1-water, 42.9%) compared with the carious dentin groups (Gp2-SDF, 15.6%; Gp2-water, 9.8%; p<0.05).Conclusions: SDF treatment had no significant influence on the mTBS of GIC to dentin. Compared with sound dentin, dentin with caries had lower mTBS to GIC.
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9
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Abstract
This 24-mo randomized controlled trial was based on a double-blind parallel design, and it compared the effectiveness of 2 fluoride application protocols in arresting dentine caries in primary teeth. Three-year-old children with active dentine caries were recruited and randomly allocated to 2 treatment groups. Children in group A received a semiannual application of a 25% silver nitrate (AgNO3) solution followed by a commercially available varnish with 5% sodium fluoride (NaF) on the carious tooth surfaces. Children in group B received a semiannual application of a 25% AgNO3 solution followed by another commercially available varnish with 5% NaF containing functionalized tricalcium phosphate (fTCP). Carious tooth surfaces that were hard when probing were classified as arrested. Intention-to-treat analysis and a hierarchical generalized linear model were undertaken. A total of 408 children with 1,831 tooth surfaces with active dentine caries were recruited at baseline, and 356 children (87%) with 1,607 tooth surfaces (88%) were assessed after 24 mo. At the 24-mo evaluation, the mean (SD) number of arrested carious tooth surfaces per child were 1.8 (2.2) and 2.6 (3.3) for group A (without fTCP) and group B (with fTCP), respectively (P = 0.003). The arrest rates at the tooth surface level were 42% for group A and 57% for group B (P < 0.001). Results of the hierarchical generalized linear model indicated that protocol B (with fTCP) had a higher predicted probability (PP = 0.656) in arresting dentine caries than protocol A (without fTCP; PP = 0.500) when the carious lesions were on buccal/lingual surfaces, were on anterior teeth, had dental plaque coverage, and were in children from low-income families (P = 0.046). In conclusion, protocol B, which applied a 25% AgNO3 solution followed by a commercially available 5% NaF varnish with fTCP semiannually, is more effective in arresting dentine caries in primary teeth as compared with protocol A, which applied a 25% AgNO3 solution followed by another commercially available 5% NaF varnish without fTCP semiannually (ClinicalTrials.gov NCT03423797).
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Affiliation(s)
- K J Chen
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Sai Ying Pun, Hong Kong SAR, China
| | - S S Gao
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Sai Ying Pun, Hong Kong SAR, China
| | - D Duangthip
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Sai Ying Pun, Hong Kong SAR, China
| | - E C M Lo
- Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Sai Ying Pun, Hong Kong SAR, China
| | - C H Chu
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Sai Ying Pun, Hong Kong SAR, China
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Innes NPT, Chu CH, Fontana M, Lo ECM, Thomson WM, Uribe S, Heiland M, Jepsen S, Schwendicke F. A Century of Change towards Prevention and Minimal Intervention in Cariology. J Dent Res 2020; 98:611-617. [PMID: 31107140 DOI: 10.1177/0022034519837252] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Better understanding of dental caries and other oral conditions has guided new strategies to prevent disease and manage its consequences at individual and public health levels. This article discusses advances in prevention and minimal intervention dentistry over the last century by focusing on some milestones within scientific, clinical, and public health arenas, mainly in cariology but also beyond, highlighting current understanding and evidence with future prospects. Dentistry was initially established as a surgical specialty. Dental caries (similar to periodontitis) was considered to be an infectious disease 100 years ago. Its ubiquitous presence and rampant nature-coupled with limited diagnostic tools and therapeutic treatment options-meant that these dental diseases were managed mainly by excising affected tissue. The understanding of the diseases and a change in their prevalence, extent, and severity, with evolutions in operative techniques, technologies, and materials, have enabled a shift from surgical to preventive and minimal intervention dentistry approaches. Future challenges to embrace include continuing the dental profession's move toward a more patient-centered, evidence-based, less invasive management of these diseases, focused on promoting and maintaining oral health in partnership with patients. In parallel, public health needs to continue to, for example, tackle social inequalities in dental health, develop better preventive and management options for existing disease risk groups (e.g., the growing aging population), and the development of reimbursement and health outcome models that facilitate implementation of these evolving strategies. A century ago, almost every treatment involved injections, a drill or scalpel, or a pair of forceps. Today, dentists have more options than ever before available to them. These are supported by evidence, have a minimal intervention focus, and result in better outcomes for patients. The profession's greatest challenge is moving this evidence into practice.
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Affiliation(s)
- N P T Innes
- 1 School of Dentistry, University of Dundee, Dundee, UK
| | - C H Chu
- 2 Faculty of Dentistry, University of Hong Kong, Hong Kong
| | - M Fontana
- 3 Cariology and Restorative Sciences, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - E C M Lo
- 2 Faculty of Dentistry, University of Hong Kong, Hong Kong
| | - W M Thomson
- 4 Department of Oral Sciences, School of Dentistry, University of Otago, Dunedin, New Zealand
| | - S Uribe
- 5 School of Dentistry, Universidad Austral de Chile, Valdivia, Chile
| | - M Heiland
- 6 Department of Oral and Maxillofacial Surgery, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - S Jepsen
- 7 Periodontology, Operative, and Preventive Dentistry, University of Bonn, Bonn, Germany
| | - F Schwendicke
- 8 Operative and Preventive Dentistry, Charité-Universitätsmedizin Berlin, Berlin, Germany
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Abstract
OBJECTIVES The aim of this noninferiority double-blind randomized clinical trial was to compare the effectiveness of the topical semiannual application of a 25% silver nitrate (AgNO3) solution followed by a 5% sodium fluoride (NaF) varnish with that of a 38% silver diamine fluoride (SDF) solution in arresting caries among preschool children. METHODS Healthy 3-y-old children with active dentine carious lesions were randomly allocated to 2 groups via computer-generated random numbers. Lesions in group A received applications of a 25% AgNO3 solution followed by a 5% NaF varnish semiannually (every 6 mo). Lesions in group B received semiannual applications of a 38% SDF solution followed by a placebo varnish. A trained examiner recorded the status of caries and oral hygiene at baseline and during follow-up examinations. The examiner, children, and their caretakers were blinded to the intervention allocation. This study adopted an intention-to-treat analysis. A noninferiority test was conducted for the data analysis. Group A's noninferiority was accepted if the lower limit of the 95% CI for the difference in the mean number of arrested surfaces was >-0.5. RESULTS A total of 1,070 children were recruited at baseline, with 535 children in each group. After 18 mo, the mean ± SD number of arrested surfaces was 3.3 ± 3.4 in group A (n = 484) and 3.2 ± 3.5 in group B (n = 476; P = 0.664). The difference in the mean number of arrested surfaces between the groups was 0.092 (95% CI, -0.322 to 0.505). Apart from black staining on the arrested lesions, no other significant side effect was observed. CONCLUSION A semiannual application of 25% AgNO3 followed by 5% NaF is no worse than a 38% SDF in arresting dentine caries among preschool children over 18 mo. The Hong Kong Research Grants Council (GRF 17107315) funded this trial, which was registered at ClinicalTrials.gov (NCT02019160). KNOWLEDGE TRANSFER STATEMENT This randomized clinical trial found that silver nitrate solution followed by sodium fluoride varnish is effective in arresting dentine caries among preschool children. As silver nitrate followed by sodium fluoride is a noninvasive and simple protocol, it can be an alternative strategy to manage dental caries among young children, especially in countries where silver diamine fluoride is not available.
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Affiliation(s)
- S S Gao
- 1 Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - D Duangthip
- 1 Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - M C M Wong
- 1 Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - E C M Lo
- 1 Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - C H Chu
- 1 Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
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Yu OY, Zhao IS, Mei ML, Lo ECM, Chu CH. Caries-arresting effects of silver diamine fluoride and sodium fluoride on dentine caries lesions. J Dent 2018; 78:65-71. [PMID: 30114443 DOI: 10.1016/j.jdent.2018.08.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 08/06/2018] [Accepted: 08/10/2018] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES To investigate the remineralising effect and bacterial growth inhibition of 38% silver diamine fluoride (SDF) solution and 5% sodium fluoride (NaF) varnish on artificial dentine caries lesions. METHODS Demineralised dentine blocks were treated with SDF + NaF (Group 1), SDF (Group 2), NaF (Group 3) and water (Group 4) and subjected to a Streptococcus mutans biofilm challenge. Lesion depth, precipitates' characteristics and matrix (collagen)-to-mineral ratio were evaluated by micro-computer tomography (micro-CT), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), respectively. The biofilm kinetics, viability and topography were assessed by counts of colony forming units (CFUs), confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM), respectively. Data were analysed by two-way ANOVA test. RESULTS The lesion depths of Groups 1-4 were 170 ± 28 μm, 160 ± 32 μm, 353 ± 38 μm and 449 ± 24 μm, respectively. The addition of NaF to SDF did not show better remineralisation than SDF (p = 0.491). Metallic silver and silver chloride were found in Groups 1 and 2. The amide I-to-hydrogen phosphate ratios of the four groups were 0.14 ± 0.02, 0.14 ± 0.01, 0.29 ± 0.05 and 0.49 ± 0.16, respectively, and the addition of NaF to SDF did not offer better protection against collagen exposure than SDF (p = 0.986). The Log10 CFUs of Groups 1-4 were 5.75 ± 0.56, 4.49 ± 0.57, 6.55 ± 0.39 and 6.40 ± 0.38, respectively. The presence of NaF reduced the antibacterial effect of SDF (p < 0.001). The SEM and CLSM images supported the findings. CONCLUSION Application of SDF with or without NaF reduced the demineralisation of dentine caries, but SDF exerted stronger inhibition of biofilm growth than SDF with NaF. CLINICAL SIGNIFICANCE NaF varnish affects the antibacterialeffects of SDF, the adjunctive application of SDF solution and NaF varnish is not recommended to arrest dentine caries in clinic.
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Affiliation(s)
- Ollie Y Yu
- Faculty of Dentistry, The University of Hong Kong, Hong Kong
| | - Irene S Zhao
- Faculty of Dentistry, The University of Hong Kong, Hong Kong
| | - May L Mei
- Faculty of Dentistry, The University of Hong Kong, Hong Kong
| | - Edward C M Lo
- Faculty of Dentistry, The University of Hong Kong, Hong Kong
| | - C H Chu
- Faculty of Dentistry, The University of Hong Kong, Hong Kong.
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13
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Mak CM, Law EC, Lee HH, Siu WK, Chow KM, Au Yeung SK, Ngan HY, Tse NK, Kwong NS, Chan GC, Lee KW, Chan WP, Wong SF, Tang MH, Kan AS, Hui AP, So PL, Shek CC, Lee RS, Wong KY, Yau EK, Poon KH, Siu S, Poon GW, Kwok AM, Ng JW, Yim VC, Ma GG, Chu CH, Tong TY, Chong YK, Chen SP, Ching CK, Chan AO, Tam S, Lau RL, Ng WF, Lee KC, Chan AY, Lam CW. The first pilot study of expanded newborn screening for inborn errors of metabolism and survey of related knowledge and opinions of health care professionals in Hong Kong. Hong Kong Med J 2018; 24:226-237. [PMID: 29888706 DOI: 10.12809/hkmj176939] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
INTRODUCTION Newborn screening is important for early diagnosis and effective treatment of inborn errors of metabolism (IEM). In response to a 2008 coroners' report of a 14-year-old boy who died of an undiagnosed IEM, the OPathPaed service model was proposed. In the present study, we investigated the feasibility of the OPathPaed model for delivering expanded newborn screening in Hong Kong. In addition, health care professionals were surveyed on their knowledge and opinions of newborn screening for IEM. METHODS The present prospective study involving three regional hospitals was conducted in phases, from 1 October 2012 to 31 August 2014. The 10 steps of the OPathPaed model were evaluated: parental education, consent, sampling, sample dispatch, dried blood spot preparation and testing, reporting, recall and counselling, confirmation test, treatment and monitoring, and cost-benefit analysis. A fully automated online extraction system for dried blood spot analysis was also evaluated. A questionnaire was distributed to 430 health care professionals by convenience sampling. RESULTS In total, 2440 neonates were recruited for newborn screening; no true-positive cases were found. Completed questionnaires were received from 210 respondents. Health care professionals supported implementation of an expanded newborn screening for IEM. In addition, there is a substantial need of more education for health care professionals. The majority of respondents supported implementing the expanded newborn screening for IEM immediately or within 3 years. CONCLUSION The feasibility of OPathPaed model has been confirmed. It is significant and timely that when this pilot study was completed, a government-led initiative to study the feasibility of newborn screening for IEM in the public health care system on a larger scale was announced in the Hong Kong Special Administrative Region Chief Executive Policy Address of 2015.
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Affiliation(s)
- C M Mak
- Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - E Cy Law
- Department of Pathology, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong.,Division of Clinical Biochemistry, Queen Mary Hospital, Pokfulam, Hong Kong
| | - H Hc Lee
- Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - W K Siu
- Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - K M Chow
- Department of Obstetrics and Gynaecology, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - S Kc Au Yeung
- Department of Obstetrics and Gynaecology, Tuen Mun Hospital, Tuen Mun, Hong Kong
| | - H Ys Ngan
- Department of Obstetrics and Gynaecology, Queen Mary Hospital, Pokfulam, Hong Kong
| | - N Kc Tse
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - N S Kwong
- Department of Paediatrics and Adolescent Medicine, Tuen Mun Hospital, Tuen Mun, Hong Kong
| | - G Cf Chan
- Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, Pokfulam, Hong Kong
| | - K W Lee
- Department of Obstetrics and Gynaecology, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - W P Chan
- Department of Obstetrics and Gynaecology, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - S F Wong
- Department of Obstetrics and Gynaecology, Tuen Mun Hospital, Tuen Mun, Hong Kong
| | - M Hy Tang
- Department of Obstetrics and Gynaecology, Queen Mary Hospital, Pokfulam, Hong Kong
| | - A Sy Kan
- Department of Obstetrics and Gynaecology, Queen Mary Hospital, Pokfulam, Hong Kong
| | - A Pw Hui
- Department of Obstetrics and Gynaecology, Queen Mary Hospital, Pokfulam, Hong Kong
| | - P L So
- Department of Obstetrics and Gynaecology, Tuen Mun Hospital, Tuen Mun, Hong Kong
| | - C C Shek
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - R Sy Lee
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - K Y Wong
- Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, Pokfulam, Hong Kong
| | - E Kc Yau
- Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - K H Poon
- Department of Paediatrics and Adolescent Medicine, Tuen Mun Hospital, Tuen Mun, Hong Kong
| | - S Siu
- Department of Paediatrics and Adolescent Medicine, Tuen Mun Hospital, Tuen Mun, Hong Kong
| | - G Wk Poon
- Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, Pokfulam, Hong Kong
| | - A Mk Kwok
- Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, Pokfulam, Hong Kong
| | - J Wy Ng
- Department of Obstetrics and Gynaecology, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - V Cs Yim
- Department of Obstetrics and Gynaecology, Tuen Mun Hospital, Tuen Mun, Hong Kong
| | - G Gy Ma
- Department of Obstetrics and Gynaecology, Queen Mary Hospital, Pokfulam, Hong Kong
| | - C H Chu
- Department of Pathology, United Christian Hospital, Kwun Tong, Hong Kong
| | - T Y Tong
- Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - Y K Chong
- Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - S Pl Chen
- Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - C K Ching
- Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - A Ok Chan
- Division of Clinical Biochemistry, Queen Mary Hospital, Pokfulam, Hong Kong
| | - S Tam
- Department of Obstetrics and Gynaecology, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - R Lk Lau
- Department of Pathology, Yan Chai Hospital, Tsuen Wan, Hong Kong
| | - W F Ng
- Department of Pathology, Yan Chai Hospital, Tsuen Wan, Hong Kong
| | - K C Lee
- Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - A Yw Chan
- Chemical Pathology Laboratory, Department of Pathology, Princess Margaret Hospital, Kwai Chung, Hong Kong
| | - C W Lam
- Department of Pathology, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong
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14
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Chu CH, Tuan PK, Cheng YP, Chan JY, Chou CY. Recurrent oral ulcers and blisters in a young woman. Clin Exp Dermatol 2016; 42:112-114. [PMID: 27917524 DOI: 10.1111/ced.12958] [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] [Accepted: 02/14/2016] [Indexed: 11/30/2022]
Affiliation(s)
- C H Chu
- Department of Dermatology, Cathay General Hospital, Taipei, Taiwan
| | - P K Tuan
- Department of Dermatology, Cathay General Hospital, Taipei, Taiwan
| | - Y P Cheng
- Department of Dermatology, Cathay General Hospital, Taipei, Taiwan
| | - J Y Chan
- Department of Dermatology, Cathay General Hospital, Taipei, Taiwan
| | - C Y Chou
- Department of Dermatology, Cathay General Hospital, Taipei, Taiwan
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Gao SS, Zhao IS, Hiraishi N, Duangthip D, Mei ML, Lo ECM, Chu CH. Clinical Trials of Silver Diamine Fluoride in Arresting Caries among Children: A Systematic Review. JDR Clin Trans Res 2016; 1:201-210. [PMID: 30931743 DOI: 10.1177/2380084416661474] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
This review aims to investigate the clinical effectiveness of silver diamine fluoride (SDF) in arresting dental caries among children. A systematic search of publications was conducted with the key words "silver diamine fluoride," "silver diammine fluoride," "silver fluoride," "diamine silver fluoride," or "diammine silver fluoride" as well as their translation in Chinese, Japanese, Portuguese, and Spanish in 7 databases: PubMed (English), Embase (English), Scopus (English), China National Knowledge Infrastructure (Chinese), Ichushi-web (Japanese), Biblioteca Virtual em Saude (Portuguese), and Biblioteca Virtual en Salud Espana (Spanish). Duplicated publications were deleted. The title and abstract were screened and irrelevant publications were excluded. The full text of the remaining publications was retrieved. Prospective clinical studies of SDF that reported a caries-arresting effect among children were included. Meta-analysis was performed for quantitative analysis. A total of 1,123 publications were found, including 19 publications of clinical trials. Sixteen clinical trials studied the caries-arresting effect on primary teeth, and 3 clinical trials were on permanent teeth. Fourteen studies used 38% SDF, 3 used 30% SDF, and 2 used 10% SDF. Meta-analysis was performed on extracted data from 8 studies using 38% SDF to arrest caries in primary teeth. The overall percentage of active caries that became arrested was 81% (95% confidence interval, 68% to 89%; P < 0.001). Apart from staining the arrested lesion black, no significant complication of SDF use among children was reported. SDF was commonly used at 38%. It was effective in arresting dentine caries in primary teeth among children. Knowledge Transfer Statement: This systematic review found that 38% silver diamine fluoride (SDF) can effectively arrest caries among children. SDF treatment is noninvasive and easily operated. It can be a promising strategy to manage dental caries in young children or those who have special needs.
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Affiliation(s)
- S S Gao
- 1 Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - I S Zhao
- 1 Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - N Hiraishi
- 2 Cariology and Operative Dentistry, Department of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - D Duangthip
- 1 Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - M L Mei
- 1 Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - E C M Lo
- 1 Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - C H Chu
- 1 Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
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16
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Duangthip D, Jiang M, Chu CH, Lo ECM. Restorative approaches to treat dentin caries in preschool children: systematic review. Eur J Paediatr Dent 2016; 17:113-121. [PMID: 27377109] [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: 06/06/2023]
Abstract
AIM Dental restorations have long been used for the management of early childhood caries, but there is a need to have an evidence based approach when selecting the most appropriate restorative intervention to treat dentin caries in preschool children. This systematic review aimed to assess the effectiveness of restorative treatments of dentin caries in primary teeth in preschool children. DESIGN A systematic search of the main electronic databases (Pubmed, Cochrane Collaboration, EMBASE) was conducted to identify peer reviewed papers published in English in the years 1947-2014. Search keywords and MeSH headings were "dental caries", "primary dentition" and "dental restoration". The inclusion criteria were clinical studies conducted in children under 6 years old, and reported findings on the longevity or failure of restorations in primary teeth. Retrieved papers were read by two reviewers independently to assess suitability for inclusion, and the final decision was made by consensus. The quality of the included studies was assessed and data were extracted for analysis. RESULTS The search identified 348 papers for screening. Among these, 218 papers did not satisfy the study inclusion criteria. Consequently, 130 full papers were retrieved and reviewed. Finally, 9 papers were included. Most of the trials were assessed as having high risk of bias. Five included studies that compared the success rates of restorations with different filling materials and liner materials. Two studies showed clinical advantages of using minimally invasive approaches in caries removal and cavity preparation. The other two trials showed low success rates of interim GI restorations done in a field setting, compared to the high caries arrest rates of silver diammine fluoride application. CONCLUSION Within the limitation of this systematic review, there is insufficient evidence to make recommendations regarding which material and technique is the most appropriate for restorative treatment in young children. Minimally invasive approaches are advantageous in operative caries management in primary teeth in preschool children. More well-designed randomised controlled trials are required to confirm these findings.
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Affiliation(s)
- D Duangthip
- Faculty of Dentistry, University of Hong Kong, Hong Kong SAR, China
| | - M Jiang
- Faculty of Dentistry, University of Hong Kong, Hong Kong SAR, China
| | - C H Chu
- Faculty of Dentistry, University of Hong Kong, Hong Kong SAR, China
| | - E C M Lo
- Faculty of Dentistry, University of Hong Kong, Hong Kong SAR, China
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17
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Fung MHT, Duangthip D, Wong MCM, Lo ECM, Chu CH. Arresting Dentine Caries with Different Concentration and Periodicity of Silver Diamine Fluoride. JDR Clin Trans Res 2016; 1:143-152. [PMID: 28989974 DOI: 10.1177/2380084416649150] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Different regimens of silver diamine fluoride (SDF) have been used to manage early childhood caries. So far, there is limited information regarding the concentrations and frequency of applications for effective caries control in primary teeth. This study aimed to compare the efficacy of 2 commercially available SDF solutions at preprepared concentrations of 38% and 12% when applied annually or biannually over 18 mo in arresting dentine caries in primary teeth. This randomized double-blinded clinical trial recruited kindergarten children aged 3 to 4 y who had at least 1 tooth with dentine caries. The children were randomly allocated to receive 4 treatment protocols: group 1, annual application of 12% SDF; group 2, biannual application of 12% SDF; group 3, annual application of 38% SDF; and group 4, biannual application of 38% SDF. Clinical examinations at 6-mo intervals were conducted to assess whether active carious lesions became arrested. Information on the children's background and oral hygiene habits was collected through a parental questionnaire at baseline and follow-up examinations. A total of 888 children with 4,220 dentine carious tooth surfaces received treatment at baseline. After 18 mo, 831 children (94%) were examined. The caries arrest rates were 50%, 55%, 64%, and 74% for groups 1, 2, 3, and 4, respectively (P < 0.001). Lesions treated with SDF biannual application had a higher chance of becoming arrested compared with those receiving SDF annual application (odds ratio, 1.33; 95% confidence interval, 1.04-1.71; P = 0.025). The interaction between concentration and lesion site was statistically significant (P < 0.001). Compared with 12% SDF, the use of 38% SDF increased a chance of becoming arrested (P < 0.05), except lesions on occlusal surfaces. Based on the 18-mo results, SDF is more effective in arresting dentin caries in the primary teeth of preschool children at 38% concentration than 12% concentration and when applied biannually rather than annually. Knowledge Transfer Statement: The results of this study can be used by clinicians and dental public health professionals when deciding which concentrations and frequency of application of silver diamine fluoride solution should be adopted for arresting dentine caries. With consideration of caries arrest treatment with silver diamine fluoride, which is painless, simple, and low cost, this information could lead to more appropriate therapeutic decisions for caries control in young children or those who lack access to affordable conventional dental care.
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Affiliation(s)
- M H T Fung
- Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, Sai Ying Pun, Hong Kong
| | - D Duangthip
- Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, Sai Ying Pun, Hong Kong
| | - M C M Wong
- Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, Sai Ying Pun, Hong Kong
| | - E C M Lo
- Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, Sai Ying Pun, Hong Kong
| | - C H Chu
- Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, Sai Ying Pun, Hong Kong
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Gao XL, Lo ECM, Chu CH, Hsu SCY. Caries risk assessment programmes for Hong Kong children. Hong Kong Med J 2015; 21 Suppl 6:42-46. [PMID: 26645883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023] Open
Affiliation(s)
- X L Gao
- Faculty of Dentistry, The University of Hong Kong
| | - E C M Lo
- Faculty of Dentistry, The University of Hong Kong
| | - C H Chu
- Faculty of Dentistry, The University of Hong Kong
| | - S C Y Hsu
- Faculty of Dentistry, National University of Singapore
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Wu TS, Li HD, Chen YW, Chen SF, Su YS, Chu CH, Pao CW, Lee JF, Lai CH, Jeng HT, Chang SL, Soo YL. Unconventional interplay between heterovalent dopant elements: Switch-and-modulator band-gap engineering in (Y, Co)-Codoped CeO2 nanocrystals. Sci Rep 2015; 5:15415. [PMID: 26486721 PMCID: PMC4613893 DOI: 10.1038/srep15415] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 09/28/2015] [Indexed: 11/13/2022] Open
Abstract
We report the experimental observation and theoretical explanation of an unconventional interplay between divalent Co and trivalent Y dopants, both of which incur oxygen vacancies in the CeO2 host that has predominantly tetravalent Ce cations. The Co dopant atoms were experimentally found to act as a switch that turns on the dormant effect of Y-modulated band-gap reduction. As revealed by density functional theory (DFT) calculations with structures verified by synchrotron-radiation x-ray measurements, a Co 3d band that hybridizes with Ce 4f band was lowered due to reduced O 2p repulsion arising from oxygen vacancies incurred by Y doping and therefore gave rise to the observed band-gap narrowing effect. Such switch-and-modulator scheme for band-gap engineering in nanocrystal materials can lead to important applications in environmental protection and solar energy harvesting technologies.
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Affiliation(s)
- T S Wu
- Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
| | - H D Li
- Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
| | - Y W Chen
- Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
| | - S F Chen
- Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
| | - Y S Su
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan
| | - C H Chu
- National Synchrotron Radiation Research Center, Hsinchu, Taiwan
| | - C W Pao
- National Synchrotron Radiation Research Center, Hsinchu, Taiwan
| | - J F Lee
- National Synchrotron Radiation Research Center, Hsinchu, Taiwan
| | - C H Lai
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan
| | - H T Jeng
- Department of Physics, National Tsing Hua University, Hsinchu, Taiwan.,Institute of Physics, Academia Sinica, Taipei, Taiwan
| | - S L Chang
- Department of Physics, National Tsing Hua University, Hsinchu, Taiwan.,National Synchrotron Radiation Research Center, Hsinchu, Taiwan
| | - Y L Soo
- Department of Physics, National Tsing Hua University, Hsinchu, Taiwan.,National Synchrotron Radiation Research Center, Hsinchu, Taiwan
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Kung AYH, Zhang S, Zheng LW, Wong GHM, Chu CH. Oral health status of chinese paediatric and adolescent oncology patients with chemotherapy in Hong Kong: a pilot study. Open Dent J 2015; 9:21-30. [PMID: 25674168 PMCID: PMC4319200 DOI: 10.2174/1874210601509010021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 12/08/2014] [Accepted: 12/14/2014] [Indexed: 11/23/2022] Open
Abstract
Aim: To study the oral health status of Chinese children and adolescents undergoing chemotherapy in Hong Kong. Method: All Chinese children and adolescent oncology patients aged 18 or below attending the Children's Centre for Cancer and Blood Disease at a hospital for chemotherapy were invited and parental consent was sought before they were accepted into the study. The study comprised of 1) a parental questionnaire, 2) the collection of medical history and 3) a clinical examination for tooth decay (caries) and mucosal status. Results: A total of 69 patients were invited, and they all participated in this study. Their mean age was 9.2±5.0 and 44 (64%) were males. Twenty-six patients (38%) had no caries experience (DMFT and/or dmft = 0). Higher caries experience was detected in participants that were not born in Hong Kong, had completed active chemotherapy, participated in school dental care service and whose parents had low educational levels. There were 41 patients with active chemotherapy, 24 of whom were diagnosed with acute leukaemia, 5 with haematological malignancies other than leukaemia and 11 with solid tumours. Antimetabolites, cytotoxic antibiotics, alkylating agents and plant alkaloids were administered in 49%, 32%, 24% and 22% of them, respectively. Twenty-six (63%) patients showed no mucosal complications. The most common oral complication was oral mucositis (24%) followed by petechiae (10%). Conclusion: About two-thirds of paediatric and adolescent cancer patients had caries experience, which was more common among those who had completed chemotherapy. Oral mucositis followed by petechiae were the two most common complications of receiving chemotherapy.
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Affiliation(s)
- A Y H Kung
- Faculty of Dentistry, the University of Hong Kong, Republic of China
| | - S Zhang
- Faculty of Dentistry, the University of Hong Kong, Republic of China
| | - L W Zheng
- Faculty of Dentistry, the University of Hong Kong, Republic of China
| | - G H M Wong
- Faculty of Dentistry, the University of Hong Kong, Republic of China
| | - C H Chu
- Faculty of Dentistry, the University of Hong Kong, Republic of China
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21
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Onorato JM, Chu CH, Ma Z, Kopcho LM, Chao HJ, Lawrence RM, Cheng D. Cell-based assay of MGAT2-driven diacylglycerol synthesis for profiling inhibitors: use of a stable isotope-labeled substrate and high-resolution LC/MS. J Lipid Res 2015; 56:747-753. [PMID: 25598079 DOI: 10.1194/jlr.d055020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To demonstrate monoacylglycerol acyltransferase 2 (MGAT2)-mediated enzyme activity in a cellular context, cells of the murine secretin tumor cell-1 line of enteroendocrine origin were used to construct human MGAT2-expressing recombinant cell lines. Low throughput and utilization of radiolabeled substrate in a traditional TLC technique were circumvented by development of a high-resolution LC/MS platform. Monitoring incorporation of stable isotope-labeled D31-palmitate into diacylglycerol (DAG) allowed selective tracing of the cellular DAG synthesis activity. This assay format dramatically reduced background interference and increased the sensitivity and the signal window compared with the TLC method. Using this assay, several MGAT2 inhibitors from different chemotypes were characterized. The described cell-based assay adds a new methodology for the development and evaluation of MGAT2 inhibitors for the treatment of obesity and type 2 diabetes.
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Affiliation(s)
- Joelle M Onorato
- Departments of Bioanalytical and Discovery Analytical Science, Bristol-Myers Squibb Company, Princeton, NJ
| | - Ching-Hsuen Chu
- Fibrosis Discovery, Bristol-Myers Squibb Company, Princeton, NJ
| | - Zhengping Ma
- Fibrosis Discovery, Bristol-Myers Squibb Company, Princeton, NJ
| | - Lisa M Kopcho
- Mechanistic Biochemistry, Bristol-Myers Squibb Company, Princeton, NJ
| | - Hannguang J Chao
- Discovery Chemistry, Research and Development, Bristol-Myers Squibb Company, Princeton, NJ
| | - R Michael Lawrence
- Discovery Chemistry, Research and Development, Bristol-Myers Squibb Company, Princeton, NJ
| | - Dong Cheng
- Fibrosis Discovery, Bristol-Myers Squibb Company, Princeton, NJ.
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Bridges S, Chang JWW, Chu CH, Gardner K. Blended learning in situated contexts: 3-year evaluation of an online peer review project. Eur J Dent Educ 2014; 18:170-179. [PMID: 24460682 DOI: 10.1111/eje.12082] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/08/2013] [Indexed: 06/03/2023]
Abstract
BACKGROUND Situated and sociocultural perspectives on learning indicate that the design of complex tasks supported by educational technologies holds potential for dental education in moving novices towards closer approximation of the clinical outcomes of their expert mentors. A cross-faculty-, student-centred, web-based project in operative dentistry was established within the Universitas 21 (U21) network of higher education institutions to support university goals for internationalisation in clinical learning by enabling distributed interactions across sites and institutions. This paper aims to present evaluation of one dental faculty's project experience of curriculum redesign for deeper student learning. METHODS A mixed-method case study approach was utilised. Three cohorts of second-year students from a 5-year bachelor of dental surgery (BDS) programme were invited to participate in annual surveys and focus group interviews on project completion. Survey data were analysed for differences between years using multivariate logistical regression analysis. Thematic analysis of questionnaire open responses and interview transcripts was conducted. RESULTS Multivariate logistic regression analysis noted significant differences across items over time indicating learning improvements, attainment of university aims and the positive influence of redesign. Students perceived the enquiry-based project as stimulating and motivating, and building confidence in operative techniques. Institutional goals for greater understanding of others and lifelong learning showed improvement over time. Despite positive scores, students indicated global citizenship and intercultural understanding were conceptually challenging. CONCLUSIONS Establishment of online student learning communities through a blended approach to learning stimulated motivation and intellectual engagement, thereby supporting a situated approach to cognition. Sociocultural perspectives indicate that novice-expert interactions supported student development of professional identities.
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Affiliation(s)
- S Bridges
- Centre for the Enhancement of Teaching and Learning/Faculty of Education, The University of Hong Kong, Pokfulam, Hong Kong
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23
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Suen RPC, Lai SML, Bridges S, Chu CH. Students' satisfaction with a dental summer programme and importance of influencing factors for choosing dentistry as their career. Eur J Dent Educ 2014; 18:104-109. [PMID: 24118664 DOI: 10.1111/eje.12063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/01/2013] [Indexed: 06/02/2023]
Abstract
AIM To study the students' satisfaction with the week-long summer programme and the importance of common influencing factors (IFs) for choosing dentistry as their career. METHODS Anonymous questionnaire was given to all 214 participants in July of 2011 and 2012. Demographic information including gender, age and education level was collected. The students were asked about their satisfaction with the programme with separate ratings for learning experiences, including hands-on workshops (HOW); clinic observations (CO); problem-based learning tutorials (PBL); and lectures (L). They also rated the relative importance of the ten common IFs. The Friedman test was used to study the order of their preferences of the programme's activities. The Chi-square test was used to study the influence of their demographic factors on the importance of the IFs. RESULTS A total of 208 students returned their questionnaires. The majority were below the age of 18 (81%), and 44% were studying in an international school. Most of the students (96%) were satisfied with the programme overall. They liked the HOWs and COs more than the PBL tutorials and Ls. 'Altruism' and 'medical/health care career' were the two most important IFs overall. 'Altruism' and 'past experience with dentist' were considered more important by those aged 18 or above. 'Past experience with dentist' and 'working with hands' were considered more important by the international school students. CONCLUSIONS Most participants were satisfied with the summer programme. They preferred practical, skill-based activities to knowledge-based activities. The importance of some IFs was associated with age and education system.
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Affiliation(s)
- R P C Suen
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
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24
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Mei ML, Ito L, Cao Y, Li QL, Chu CH, Lo ECM. The inhibitory effects of silver diamine fluorides on cysteine cathepsins. J Dent 2013; 42:329-35. [PMID: 24316241 DOI: 10.1016/j.jdent.2013.11.018] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [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: 10/02/2013] [Revised: 11/22/2013] [Accepted: 11/26/2013] [Indexed: 10/25/2022] Open
Abstract
AIM The expression of cysteine cathepsins in human carious dentine suggests that this enzyme contributes to the collagen degradation in caries progress. This study investigated whether silver diamine fluoride (SDF) inhibited the activity of cysteine cathepsins. METHODS Three commercial SDF solutions with concentrations at 38%, 30% and 12% were studied. Two fluoride solutions with the same fluoride ion (F(-)) concentrations as the 38% and 12% SDF solutions, and 2 silver solutions with the same silver ion (Ag(+)) concentrations as the 38% and 12% SDF solutions were prepared. Five samples of each experimental solution were used to study their inhibitory effect on two cathepsins (B and K) using cathepsin assay kits. Positive control contained assay buffer and cathepsins dilution was used to calculate the percentage inhibition (difference between the mean readings of the test solution and control solution divided by that of the control group). RESULTS The percentage inhibition of 38%, 30% and 12% SDF on cathepsin B were 92.0%, 91.5% and 90.3%, respectively (p<0.001); on cathepsin K were 80.6%, 78.5% and 77.9%, respectively (p<0.001). Ag(+) exhibited the inhibitory effect against both cathepsin B and K with or without the presence of F(-) (p<0.01). The solutions containing Ag(+) have significantly higher inhibitory effect than the solutions containing F(-) only (p<0.01). CONCLUSION According to this study, SDF solution at all 3 tested concentrations significantly inhibited the activity of cathepsin B and K.
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Affiliation(s)
- May L Mei
- Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region
| | - L Ito
- Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Y Cao
- Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region; College of Stomatology, Anhui Medical University, Hefei, PR China
| | - Q L Li
- College of Stomatology, Anhui Medical University, Hefei, PR China
| | - C H Chu
- Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region.
| | - Edward C M Lo
- Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region
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25
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Lam A, Chu CH. Caries management with fluoride agents. N Y State Dent J 2012; 78:29-36. [PMID: 23488322] [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: 06/01/2023]
Abstract
Dental caries is the single most common, chronic oral disease of childhood. It is progressive and cumulative, and becomes more complex over time. The Surgeon General's Report on Oral Health revealed that more than 51 million school hours are lost each year as a result of dental problems. Contemporary caries management philosophy has changed from the traditional surgical approach to a medical model that emphasizes prevention. Among various strategies for caries prevention or reduction, fluoride therapy has been highly promoted. Various in-office and over-the-counter fluoride products are available for caries prevention. Dental professionals should identify and assess the caries risk level of patients and optimize the use of fluorides in caries management. Since multiple sources of fluoride exposure exist, a coordinated approach to fluoride delivery is essential.
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Affiliation(s)
- Anty Lam
- Dental Hygiene Department, New York City College of Technology, City University of New York, Brooklyn, NY, USA.
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26
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Abstract
To investigate the effectiveness of topical fluorides in preventing fissure caries, we conducted a randomized controlled trial with parallel groups. In total, 501 children (1,539 molars, 3,078 sites), mean age 9.1 years, who had at least one sound permanent first molar with deep fissures or fissures with signs of early caries were recruited. They were randomly allocated among four groups: (1) resin sealant, single placement; (2) 5% NaF varnish, semi-annual application; (3) 38% silver diamine fluoride (SDF) solution, annual application; and (4) placebo control. Follow-up examinations were conducted every 6 months by a masked examiner. After 24 months, 485 children (97%) were examined. Proportions of pit/fissure sites with dentin caries in the sealant, NaF, SDF, and control groups were 1.6%, 2.4%, 2.2%, and 4.6%, respectively. A multi-level logistic regression analysis accounting for the effects of data clustering and confounding factors showed that fissures in any of the three treatment groups had significantly lower risks of carious cavity development into dentin than did controls (p < 0.05). We concluded that placement of resin sealant, semi-annual application of NaF varnish, and annual application of SDF solution are all effective in preventing pit and fissure caries in permanent molars (ClinicalTrials.gov number CT01446107).
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Affiliation(s)
- B Y Liu
- Faculty of Dentistry, University of Hong Kong, 3/F, Prince Philip Dental Hospital, Hong Kong SAR
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Chu CH, Chau AMH, Lo ECM, Lam A. Planning and implementation of community oral health programs for caries management in children. Gen Dent 2012; 60:210-217. [PMID: 22623460] [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: 06/01/2023]
Abstract
Tooth decay or cavities (dental caries) can have a significant impact on children's quality of life, causing pain, infection, and other problems in the oral environment. Good oral health is a fundamental element of good general health for children, yet dental caries is still prevalent among children in many countries. Dental caries is well-understood, and effective prevention is an attainable goal. Dental professionals should actively engage with communities--in particular, the underprivileged--to identify dental caries problems and implement appropriate and effective community oral health programs (COHPs) to improve oral health and reduce oral health inequalities. This paper discusses COHPs as well as the steps involved in caries prevention for children. These steps cannot ensure the success of every COHP, but they are helpful for developing, integrating, expanding, and enhancing them. The effectiveness of COHPs for the prevention of caries in children varies from country to country, according to cultural, social, economic, and health care settings. Careful consideration of the local situation is required when selecting the elements of COHPs.
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Chen SH, Wu HM, Ossola B, Schendzielorz N, Wilson BC, Chu CH, Chen SL, Wang Q, Zhang D, Qian L, Li X, Hong JS, Lu RB. Suberoylanilide hydroxamic acid, a histone deacetylase inhibitor, protects dopaminergic neurons from neurotoxin-induced damage. Br J Pharmacol 2012; 165:494-505. [PMID: 21726209 DOI: 10.1111/j.1476-5381.2011.01575.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Prevention or disease-modifying therapies are critical for the treatment of neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease and Huntington's disease. However, no such intervention is currently available. Growing evidence has demonstrated that administration of histone deacetylase (HDAC) inhibitors ameliorates a wide range of neurologic and psychiatric disorders in experimental models. Suberoylanilide hydroxamic acid (SAHA) was the first HDAC inhibitor approved by the Food and Drug Administration for the sole use of cancer therapy. The purpose of this study was to explore the potential new indications of SAHA for therapy of neurodegenerative diseases in in vitro Parkinson's disease models. EXPERIMENTAL APPROACH Mesencephalic neuron-glia cultures and reconstituted cultures were used to investigate neurotrophic and neuroprotective effects of SAHA. We measured toxicity in dopaminergic neurons, using dopamine uptake assay and morphological analysis and expression of neurotrophic substances by enzyme-linked immunosorbent assay and real-time RT PCR. KEY RESULTS In mesencephalic neuron-glia cultures, SAHA displayed dose- and time-dependent prolongation of the survival and protection against neurotoxin-induced neuronal death of dopaminergic neurons. Mechanistic studies revealed that the neuroprotective effects of SAHA were mediated in part by promoting release of neurotrophic factors from astroglia through inhibition of histone deacetylation. CONCLUSION AND IMPLICATIONS The novel neurotrophic and neuroprotective effects of SAHA demonstrated in this study suggest that further study of this HDAC inhibitor could provide a new therapeutic approach to the treatment of neurodegenerative diseases.
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Affiliation(s)
- S H Chen
- Institute of Behavioral Medicine, College of Medicine, National Cheng-Kung University, Tainan, Taiwan
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Xie KX, Wang XY, Gao XJ, Yuan CY, Li JX, Chu CH. Fracture resistance of root filled premolar teeth restored with direct composite resin with or without cusp coverage. Int Endod J 2012; 45:524-9. [PMID: 22242600 DOI: 10.1111/j.1365-2591.2011.02005.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM To evaluate the fracture resistance and fracture patterns of root filled maxillary first premolar teeth (with mesio-occlusal cavity preparation) restored with several composite restoration designs. METHODOLOGY One hundred extracted sound human maxillary first premolars were randomly divided into five groups. Group 1 remained untreated (negative control). Conventional root canal treatment with additional mesial-occlusal cavity preparation was carried out on teeth in groups 2-5. In group 2, the teeth were restored intra-coronally with direct composite resin (positive control). In group 3, the palatal cusps of the teeth were reduced, and the cavities were restored with composite resin covering the palatal cusp (partial coverage). In group 4, the buccal and palatal cusps along with the distal marginal ridges were reduced; the cavities and cusps were restored with composite resin (conventional full coverage). In group 5, the buccal and palatal cusps were reduced but the distal marginal ridges were conserved. The cavities and the cusps were restored with composite resin (modified full coverage). All teeth were subjected to a progressive compressive loading parallel to their longitudinal axis until fracture. Fracture resistance was analysed using the one-way ANOVA and Fisher's LSD test. Fracture patterns were analyzed with chi-square test. The significance level was set at 0.05. RESULTS The fracture resistance (mean ± SD) of groups 1-5 was 1131 ± 207N, 904 ± 184N, 927 ± 224N, 1095 ± 289N and 1085 ± 243N, respectively (groups 1, 4, 5 > groups 2, 3; P = 0.004). Cusp fractures were recorded as the fracture pattern in 20 (100%), 19 (95%), 16 (80%), 8 (40%) and 12 (60%) premolars in groups 1-5, respectively (groups 1, 2 > groups 4, 5; group 3 > group 4; P < 0.001). CONCLUSIONS When direct composite resin was used to restore root filled maxillary first premolar teeth involving a proximal surface, those restored with full-coverage designs had greater fracture resistance.
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Affiliation(s)
- K X Xie
- Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing, China
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30
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Abstract
The aim was to study oral health status, salivary function, and oral features of Chinese people with Systemic Sclerosis (SSc). Chinese people with SSc attending a university specialist clinic were invited for a questionnaire survey and a clinical examination. Ethics approval was sought (UW 08-305). Gender- and age-matched individuals without SSc who attended a university dental hospital were recruited for comparison. Forty-two SSc patients with a mean age of 54.0 ± 12.2 were examined. This study found no Chinese people with systemic sclerosis were periodontally healthy and many (76%) had periodontal pockets despite most of them (93%) practiced daily tooth-brushing. They all had caries experience (DMFT = 10.5) and many (65%) had untreated decay. Mucosal telangiectasia was a common oral feature (80%). They had lower resting salivary flow rates (0.18 ± 0.17 ml/min vs. 0.31 ± 0.21 ml/min; p = 0.003) and pH values (6.90 ± 0.40 vs. 7.28 ± 0.31; p < 0.001) and reduced maximal mouth opening (40.1 ± 6.5 mm vs. 43.6 ± 7.0 mm) than people without SSc.
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Affiliation(s)
- C H Chu
- Faculty of Dentistry, The University of Hong Kong, 3B61, Prince Philip Dental Hospital, 34 Hospital Road, Hong Kong SAR, China.
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31
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Lam A, Chu CH. Caries management with fluoride varnish of children in U.S. N Y State Dent J 2011; 77:38-42. [PMID: 21894831] [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: 05/31/2023]
Abstract
Fluoride varnish prolongs the contact time between fluoride and tooth surface to reduce caries. Its active ingredient is usually 5% sodium fluoride, or 22,600 ppm fluoride. Its use as an "off-label" approved drug for caries control in the United States has been on the rise, along with increasing evidence of its efficacy in case-based studies. It sets rapidly on teeth, and it is simple, quick and easy to apply. Side effects or complications of its use are rare. Gagging and swallowing are unusual. The risk of dental fluorosis is minimal. And it can be safely used in young children.
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32
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Chu CH, Lam A, Lo ECM. Dentin hypersensitivity and its management. Gen Dent 2011; 59:115-124. [PMID: 21903521] [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: 05/31/2023]
Abstract
Dentin hypersensitivity is a common patient complaint that is more prevalent than the profession realizes. It is important for dentists to diagnose dentin hypersensitivity by exclusion and provide appropriate treatment recommendations for patients. Various treatment methods have been proposed but no universally accepted desensitizing agent or treatment has been identified. When a patient has symptoms that can be attributed to dentin hypersensitivity, a thorough clinical examination should be carried out to rule out other likely causes prior to diagnosis and treatment. Depending on the identified cause, a combination of individualized instructions on proper oral health behaviors, use of at-home products, and professional treatment may be required to manage the problem.
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Chu CH, Lo ECM. Oral health status of Chinese teenagers with cerebral palsy. Community Dent Health 2010; 27:222-226. [PMID: 21473357] [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: 05/30/2023]
Abstract
OBJECTIVES To examine caries experience, periodontal status, and oral hygiene practices of Chinese teenagers with cerebral palsy in Hong Kong. PARTICIPANTS Chinese students aged 12 years or older studying in the three special schools of the Spastics Association of Hong Kong were invited to participate. CLINICAL SETTING MEASURES: Caries experience and periodontal status were assessed by a clinical oral examination using World Health Organization criteria. Information on oral hygiene and snacking habits were obtained by a questionnaire. Information on medical history and mental status was obtained from school records. RESULTS Of 65 students with a mean (+/- SD) age of 15.0 +/- 2.0 years, the majority (74%) had spastic cerebral palsy. About half of the participants (49%) had mild mental retardation and 31% had moderate mental retardation. Caries experience as the mean DMFT score (+/- SD) was 1.2 +/- 1.9 and 43% of caries remained untreated; however, 62% of participants had no caries experience. None of the participants had healthy gums, 57% had calculus, and 66% snacked between meals. They all practised daily tooth brushing, with or without caregiver assistance. About one third (33%) also used mouthrinse. There were no significant differences in caries experience between the participants who brushed their teeth with and those who brushed without caregiver assistance. CONCLUSIONS The mean DMFT score of this sample of Chinese teenagers with cerebral palsy was 1.2. Despite daily tooth brushing, the periodontal status of all participants was poor. Providing oral hygiene instructions and scaling are essential to improve their oral health.
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Affiliation(s)
- C H Chu
- Prince Philip Dental Hospital, 34 Hospital Road, Hong Kong SAR, China.
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Huang SH, Chu CH, Yu JC, Chuang WC, Lin GJ, Chen PL, Chou FC, Chau LY, Sytwu HK. Transgenic expression of haem oxygenase-1 in pancreatic beta cells protects non-obese mice used as a model of diabetes from autoimmune destruction and prolongs graft survival following islet transplantation. Diabetologia 2010; 53:2389-400. [PMID: 20683574 DOI: 10.1007/s00125-010-1858-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Accepted: 07/05/2010] [Indexed: 01/05/2023]
Abstract
AIMS/HYPOTHESIS Haem oxygenase 1 (HO-1) has strong anti-apoptotic, anti-inflammatory and antioxidative effects that help protect cells against various forms of immune attack. We investigated whether transgenic expression of Ho-1 (also known as Hmox1) in pancreatic beta cells would protect NOD mice from autoimmune damage and prolong graft survival following islet transplantation. METHODS To evaluate the protective effect of beta cell-specific HO-1 in autoimmune diabetes, we used an insulin promoter-driven murine Ho-1 construct (pIns-mHo-1) to generate a transgenic NOD mouse. Transgene expression, insulitis and the incidence of diabetes in mice were characterised. Lymphocyte composition, the development of T helper (Th)1, Th2 and T regulatory (Treg) cells, T cell proliferation and lymphocyte-mediated disease transfer were analysed. The potential effects of transgenic islets and islet transplantation on apoptosis, inflammation and the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) were evaluated. RESULTS Transgenic mice showed less severe insulitis and a lower incidence of diabetes than non-transgenic control littermates. Lymphocyte composition and functions were not affected. Islets from transgenic mice expressed lower levels of proinflammatory cytokines/chemokines, proapoptotic gene expression and amounts of ROS/RNS, and were more resistant to TNF-α- and IFN-γ-induced apoptosis. Islet grafts from transgenic mice also survived longer in diabetic recipients than control islets. CONCLUSIONS/INTERPRETATION Transgenic overexpression of Ho-1 in beta cells protected NOD mice from diabetes and delayed the autoimmune destruction of islet grafts, providing valuable insight into the development of better strategies for clinical islet transplantation in patients with type 1 diabetes.
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Affiliation(s)
- S H Huang
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of China
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Fu CY, Chu CH, Liu TP, Hong ZJ, Hsu KF, Liu YC, Lu TC, Chan DC, Yu JC. The relationship between acid-suppressing drugs and phytobezoar formation: a retrospective analysis and discussion of phytobezoar formation. Acta Chir Belg 2010; 110:595-597. [PMID: 21337839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
OBJECTIVES Although phytobezoars are a rare cause of gastrointestinal obstruction, they are most commonly found in patients with previous gastric surgery. It is well known that predisposing factors of phytobezoar formation are ingestion of fruits containing soluble tannin, presence of dilute hydrochloric acid in the stomach, and gastric stasis or delayed emptying. We investigated whether intake of acid-suppressing drugs that neutralize gastric acidity or inhibit gastric acid secretion to constitute a hypo-acidic condition, increases the risk of phytobezoar formation. MATERIALS AND METHODS Between September 1992 and October 2008, 32 patients (24 male and 8 female) with gastrointestinal phytobezoars were diagnosed either surgically or endoscopically at the Tri-Service General Hospital, Taipei, Republic of China. The data were collected from hospital records and analyzed retrospectively. RESULTS Eighteen (56.25%) of all patients had previous gastric surgery and 6 (42.9%) of the 14 patients who had not undergone surgery had diabetes mellitus. The majority of admissions were during winter and spring (between October and March) (P < 0.01) and none of the patients had taken acid-suppressing drugs during the 6 months before detection of gastrointestinal phytobezoars. CONCLUSIONS In our study, intake of acid-suppressing drugs did not increase the risk of phytobezoar formation in patients with normal gastric motility. Moreover, we believe that the major factor in phytobezoar formation is gastric stasis or delayed emptying, which sufficiently prolongs the retention period of materials in the stomach, while dilute hydrochloric acid is a minor factor.
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Affiliation(s)
- C Y Fu
- Division of General Surgery, Department of Surgery, Tri-Service General Hospital, National Defence Medical Centre, Taipei, Taiwan, Republic of China
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Abstract
Objectives To study the dietary behavior and knowledge about dental erosion and self-reported symptoms that can be related to dental erosion among Chinese adults in Hong Kong. Methods Chinese adults aged 25-45 years were randomly selected from a list of registered telephone numbers generated by computer. A telephone survey was administered to obtain information on demographic characteristics, dietary habits, dental visits, and knowledge of and presence of self-reported symptoms that can be related to dental erosion. Results A total of 520 participants were interviewed (response rate, 75%; sampling error, ± 4.4%) and their mean age was 37. Most respondents (79%) had ever had caries, and about two thirds (64%) attended dental check-ups at least once a year. Respondents had a mean of 5.4 meals per day and 36% had at least 6 meals per day. Fruit (89%) and lemon tea/water (41%) were the most commonly consumed acidic food and beverage. When asked if they ever noticed changes in their teeth, most respondents (92%) said they had experienced change that can be related to erosion. However, many (71%) had never heard about dental erosion and 53% mixed up dental erosion with dental caries. Conclusion Hong Kong Chinese adults have frequent intake of food and many have experienced symptoms that can be related to dental erosion. Their level of awareness of and knowledge about dental erosion is generally low, despite most of them have regular dental check-ups. Dental health education is essential to help the public understand dental erosion and its damaging effects.
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Affiliation(s)
- C H Chu
- Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
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Chu CH, Chen IJ. SU-GG-I-82: Performance Assessment of X-Ray QA Instruments Used in Mammography. Med Phys 2010. [DOI: 10.1118/1.3468115] [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: 11/07/2022] Open
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Chu CH, Mei ML, Lo ECM. Use of fluorides in dental caries management. Gen Dent 2010; 58:37-80. [PMID: 20129891] [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: 05/28/2023]
Abstract
Fluoride is commonly and widely used to prevent and even arrest caries. The clinical effects of fluorides depend on the chemical compounds utilized and the methods used to apply the fluoride ion to the surface of the tooth. Fluorosis has been reported in conjunction with increased doses of fluoride. A coordinated approach to fluoride delivery is essential to avoid the risk of fluorosis.
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Affiliation(s)
- C H Chu
- Faculty of Dentistry, University of Hong Kong, China
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Abstract
ATP citrate lyase (ACL) is a cytosolic enzyme that catalyzes the synthesis of acetyl-CoA and oxaloacetate using citrate, CoA, and ATP as substrates and Mg(2+) as a necessary cofactor. The ACL-dependent synthesis of acetyl-CoA is thought to be an essential step for the de novo synthesis of fatty acids and cholesterol. For this reason, inhibition of ACL has been pursued as a strategy to treat dyslipidemia and obesity. Traditionally, ACL enzyme activity is measured indirectly by coupling to enzymes such as malate dehydrogenase or chloramphenicol acetyl transferase. In this report, however, we describe a novel procedure to directly measure ACL enzyme activity. We first identified a convenient method to specifically detect [(14)C]acetyl-CoA without detecting [(14)C]citrate by MicroScint-O. Using this detection system, we devised a simple, direct, and homogeneous ACL assay in 384-well plate format that is suitable for high-throughput screening. The current assay consists of 1) incubation of ACL enzyme with [(14)C]citrate and other substrates/cofactors CoA, ATP, and Mg(2+), 2) EDTA quench, 3) addition of MicroScint-O, the agent that specifically detects product [(14)C]acetyl-CoA, and 4) detection of signal by TopCount. This unique ACL assay may provide more efficient identification of new ACL inhibitors and allow detailed mechanistic characterization of ACL/inhibitor interactions.
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Affiliation(s)
- Zhengping Ma
- Department of Metabolic Research, Research and Development, Bristol-Myers Squibb Company, Princeton, NJ 08543-5400, USA
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Chu CH, Lo ECM, You DSH. Clinical diagnosis of fissure caries with conventional and laser-induced fluorescence techniques. Lasers Med Sci 2009; 25:355-62. [PMID: 19259758 PMCID: PMC2946546 DOI: 10.1007/s10103-009-0655-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2008] [Accepted: 02/05/2009] [Indexed: 11/30/2022]
Abstract
We studied the in vivo validity of dentinal fissure caries diagnosis by visual examination, bitewing radiography, and use of a laser-induced fluorescence device (DIAGNOdent). A total of 144 and second molars with macroscopically intact occlusal surfaces in 41 Chinese young adults were examined visually, by bitewing radiography, and by DIAGNOdent. Visual examination after pit and fissure opening was used as the reference standard. The sensitivity and specificity of detecting caries that had extended into the dentin were, respectively, 0.89 and 0.44 by visual detection of opacity or discoloration after air drying, 0.13 and 1.00 by bitewing radiography to detect radiolucency extending into the dentin, and 0.70 and 0.84 by DIAGNOdent testing with a cut-off score of 40. Caries detection by a combination of visual examination and DIAGNOdent had a sensitivity of 0.67 and specificity of 0.94. Receiver operating characteristic analysis showed that this combined approach was superior to the other methods.
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Affiliation(s)
- C H Chu
- The University of Hong Kong, 34 Hospital Road, Hong Kong, SAR, China.
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Chu CH, Choy BHB, Lo ECM. Occlusion and orthodontic treatment demand among Chinese young adults in Hong Kong. Oral Health Prev Dent 2009; 7:83-91. [PMID: 19408820] [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: 05/27/2023]
Abstract
PURPOSE The aim of this study was to investigate the occlusion, the demand for orthodontic treatment and the reasons for this among Chinese young adults in Hong Kong. MATERIALS AND METHODS A questionnaire was used to study previous orthodontic experience and to evaluate the orthodontic treatment demand and the reasons for this in Chinese university students. Among those who had no orthodontic treatment, 120 participants were invited for an occlusal assessment. Their treatment need was graded using the index of orthodontic treatment need. RESULTS A total of 240 students, aged 18 to 27 years, completed the questionnaire survey. Thirty-one students (13%) had orthodontic treatment. Sixty-seven (28%) students had orthodontic treatment demand, and their common reasons were to improve appearance (78%), self-image (36%), self-confidence (34%) as well as to follow parental advice (24%). The reasons for those students who would not consider having orthodontic treatment included no perceived need (64%), long treatment time (18%) and high treatment fee (14%). All 120 invited participants who had no orthodontic treatment attended the occlusal assessment. One-fifth had a normal occlusion. Most malocclusions were manifested as Angle Class I (48%) followed by Class III (21%) malocclusion. Fifty-six students (47%) had moderate and 40 students (33%) had 'great' or 'extremely great' treatment need. CONCLUSIONS The most prevalent malocclusion among this group of Chinese young adults was Angle Class I malocclusion. Although the majority of the Chinese young adults had malocclusion with a high treatment need, their demand for orthodontic treatment was relatively low. Apart from consideration of dental health needs, the common reasons for orthodontic treatment demand were influenced by the desire for improvement in appearance.
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Affiliation(s)
- C H Chu
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China.
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Cheng D, Iqbal J, Devenny J, Chu CH, Chen L, Dong J, Seethala R, Keim WJ, Azzara AV, Lawrence RM, Pelleymounter MA, Hussain MM. Acylation of acylglycerols by acyl coenzyme A:diacylglycerol acyltransferase 1 (DGAT1). Functional importance of DGAT1 in the intestinal fat absorption. J Biol Chem 2008; 283:29802-11. [PMID: 18768481 DOI: 10.1074/jbc.m800494200] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Acyl coenzyme A:diacylglycerol acyltransferase 1 (DGAT1) is one of the four intestinal membrane bound acyltransferases implicated in dietary fat absorption. Recently, it was found that, in addition to acylating diacylglycerol (DAG), DGAT1 also possesses robust enzymatic activity for acylating monoacylglycerol (MAG) (Yen, C. L., Monetti, M., Burri, B. J., and Farese, R. V., Jr. (2005) J. Lipid Res. 46, 1502-1511). In the current paper, we have conducted a detailed characterization of this reaction in test tube, intact cell culture, and animal models. Enzymatically, we found that triacylglycerol (TAG) synthesis from MAG by DGAT1 does not behave according to classic Michaelis-Menten kinetics. At low concentrations of 2-MAG (<50 microm), the major acylation product by DGAT1 was TAG; however, increased concentrations of 2-MAG (50-200 microm) resulted in decreased TAG formation. This unique product/substrate relationship is similar to MGAT3 but distinct from DGAT2 and MGAT2. We have also found that XP620 is an inhibitor that selectively inhibits the acylation of MAG by DGAT1 (IC(50) of human DGAT1: 16.6+/-4.0 nM (MAG as substrate) and 1499+/-318 nM (DAG as substrate); IC(50) values of human DGAT2, MGAT2, and MGAT3 are >30,000 nM). Using this pharmacological tool, we have shown that approximately 76 and approximately 89% of the in vitro TAG synthesis initiated from MAG is mediated by DGAT1 in Caco-2 cell and rat intestinal mucosal membranes, respectively. When applied to intact cultured cells, XP620 substantially decreased but did not abolish apoB secretion in differentiated Caco-2 cells. It also decreased TAG and DAG syntheses in primary enterocytes. Last, when delivered orally to rats, XP620 decreased absorption of orally administered lipids by approximately 50%. Based on these data, we conclude that the acylation of acylglycerols by DGAT1 is important for dietary fat absorption in the intestine.
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Affiliation(s)
- Dong Cheng
- Department of Metabolic Diseases, Bristol-Myers Squibb Company, Princeton, New Jersey 08543-5400, USA.
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Chu CH, Lo E. Uses of sodium fluoride varnish in dental practice. Ann R Australas Coll Dent Surg 2008; 19:58-61. [PMID: 19728633] [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: 05/28/2023]
Abstract
Fluoride varnish is developed to prolong the contact time between fluoride and tooth surface, so that the tooth becomes more resistant to caries attack. The active ingredient of fluoride varnish is usually 5% sodium fluoride, (22,600 ppm fluoride). Studies have found that fairly insoluble globules of calcium fluoride-like material formed on the tooth surface after topical fluoride application. These globules act as a reservoir of fluoride in the mouth for a prolonged period of time. Systematic reviews corroborate evidence for the efficacy of fluoride varnish in the prevention of dental caries. Sodium fluoride varnish is used to prevent caries development, arrest early enamel and even soft dentine caries through promotion of remineralization of carious tooth substance. It is also used to treat tooth hypersensitivity. Some use it as a provisional luting agent by itself or combined with other provisional luting agents for cementing provisional crowns. Fluoride varnish has recently gained much attention in dentistry because it is quick and easy to apply. It sets rapidly on teeth, and gagging and swallowing is unusual. Side-effects or complications of its use are rare. Studies show that fluoride varnish is safe for young children and the risk of dental fluorosis is minimal. The simplicity of its application makes it very suitable and practical for use in dental clinics and outreach dental services, especially in young children and in other special needs groups.
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Affiliation(s)
- C H Chu
- Faculty of Dentistry, The University of Hong Kong.
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Chu CH, Lo ECM. Promoting caries arrest in children with silver diamine fluoride: a review. Oral Health Prev Dent 2008; 6:315-321. [PMID: 19178097] [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: 05/27/2023]
Abstract
Although there has been a decrease in the prevalence and the severity of dental caries in children over the past few decades, the benefits have not been equally shared by many low-income or underserved children in many industrialised countries, or children in developing countries. Dental caries is still the most common and challenging dental disease in children for a clinician to treat. Silver diamine fluoride (SDF) has been in use to arrest dental caries in many countries. A 38% (44,800 ppm fluoride ions) SDF solution is commonly used to arrest caries in primary teeth of children, especially those children who are young and difficult to manage. Application of SDF to arrest dental caries is a non-invasive procedure that is quick and simple to use. However, it stains the carious teeth and turns the arrested caries black. It also has an unpleasant metallic taste that is not liked by patients, especially children. The low cost of SDF and its simplicity in application suggest that SDF is an appropriate therapeutic agent for use in community dental health projects. Reports of available studies found no severe pulpal damage after SDF application. The current literature suggests that SDF can be an effective agent in preventing new caries and in arresting dental caries in the primary teeth of the children. It can be used to arrest caries progression in very young children who are less cooperative, and it allows definitive restoration to be performed when they grow older and become more receptive to dental procedures.
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Affiliation(s)
- C H Chu
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China.
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Liu YJ, Juan CJ, Chen CY, Wang CY, Wu ML, Lo CP, Chou MC, Huang TY, Chang H, Chu CH, Li MH. Are the local blood oxygen level-dependent (BOLD) signals caused by neural stimulation response dependent on global BOLD signals induced by hypercapnia in the functional MR imaging experiment? Experiments of long-duration hypercapnia and multilevel carbon dioxide concentration. AJNR Am J Neuroradiol 2007; 28:1009-14. [PMID: 17569947 PMCID: PMC8134170 DOI: 10.3174/ajnr.a0535] [Citation(s) in RCA: 12] [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: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The relationship between the local blood oxygen level-dependent (BOLD) signals caused by neural stimulation (fBOLD) and the global BOLD signals induced by hypercapnia (hBOLD) has not been fully investigated. In this study, we examine whether fBOLD is modulated by hBOLD signals, by means of experiments using a relatively wide range of inhaled carbon dioxide (CO(2)) for a long duration of 5 minutes. MATERIALS AND METHODS Ten healthy volunteers were recruited, each undergoing 6 separate experiments by inhaling gas mixtures with different fractions of CO(2) (room air, 3%-7%). Each experiment contained 3 phases, prehypercapnic, hypercapnic, and posthypercapnic, during which boxcar visual stimulus was given. The local fBOLD signals were measured from areas showing activation patterns highly correlated with the visual stimulus paradigm, whereas the global hBOLD signals were measured from areas showing no visual activations. Percentage changes in fBOLD during transient-state hypercapnia and steady-state hypercapnia were both investigated in response to varying degrees of hypercapnic perturbations. RESULTS The hBOLD signals increased with increase of inhaled CO(2) fractions. The duration for the hBOLD signals to reach steady state prolonged with increase of inhaled CO(2) fractions. Normalized fBOLD ratio was inversely related to the inhaled CO(2) during steady-state hypercapnia but showed positive association with hBOLD during transient-state hypercapnia. CONCLUSION Our study concludes that the steady-state fBOLD signal intensity is dependent on and inversely related to the hBOLD signals. Previous reports documenting independent and additive relationships between hBOLD and fBOLD may likely be due to transient-state observations.
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Affiliation(s)
- Y J Liu
- Department of Automatic Control Engineering, Feng Chia University, Taichung, Taiwan, ROC
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Chu CH, Cheng D. Expression, purification, characterization of human 3-methylcrotonyl-CoA carboxylase (MCCC). Protein Expr Purif 2007; 53:421-7. [PMID: 17360195 DOI: 10.1016/j.pep.2007.01.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2007] [Revised: 01/25/2007] [Accepted: 01/25/2007] [Indexed: 11/24/2022]
Abstract
The current study reports the use of baculovirus system to express functionally active human recombinant 3-methylcrotonyl-CoA carboxylase (MCCC), a heteromultimeric complex that is composed of alpha and beta subunits which are encoded by distinct genes. Using immuno-affinity purification, an efficient protocol has been developed to purify the active MCCC which appears to reside in a approximately 500-800kDa complex in Superpose-6 gel-filtration chromatography. Consistent with the native enzyme, in the recombinant human MCCC, the stoichiometry of alpha and beta subunits are at a one:one ratio. The k(cat) value of the recombinant enzyme is determined to be approximately 4.0s(-1). It also possesses K(m) values (ATP: 45+/-11microM; 3-methylcrotonyl-CoA: 74+/-7microM) similar to those reported for the native enzyme. The recombinant human MCCC described here may provide a counter-screen enzyme source for testing cross reactivity for inhibitors against acetyl-CoA carboxylases which are designed to treat obesity, type 2 diabetes and other metabolic disorders.
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Affiliation(s)
- Ching-Hsuen Chu
- Department of Obesity and Metabolic Research, Pharmaceutical Research Institute, Bristol-Myers Squibb Company, P.O. Box 5400, Princeton, NJ 08543-5400, USA
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Lin IT, Chang WH, Shih SC, Lin SC, Chen YJ, Wang HY, Chu CH, Wang TE, Liou TC, Shyung LR, Bair MJ. Successful endoscopic polypectomy for colonic vascular ectasia presenting as pedunculated polypoid lesion. Endoscopy 2007; 39 Suppl 1:E253-4. [PMID: 17957630 DOI: 10.1055/s-2007-966407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Affiliation(s)
- I T Lin
- Division of Gastroenterology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei, Taiwan
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Chu CH, Lo ECM. A review of sodium fluoride varnish. Gen Dent 2006; 54:247-53. [PMID: 16903196] [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: 05/11/2023]
Abstract
Fluoride varnish was incorporated into clinical dentistry to reduce caries; its use in the U.S. has increased progressively since it was approved by the FDA in 1994. This paper reviewed clinical studies and found that fluoride varnish's effectiveness in caries prevention, ease of application, and safety give it an advantage over other types of topical fluoride treatments (such as gels and rinses) or other caries management methods. As a result, it is regarded as one of the superior topical fluoride agents for young children.
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Abstract
OBJECTIVE To describe the dental caries status of preschool children in Hong Kong and factors which affect their caries status. DESIGN 658 preschool children aged 4 to 6 years from six randomly selected kindergartens in Hong Kong were surveyed in December 1997. A questionnaire to investigate possible explanatory variables for caries status was completed by their parents. Dental caries was diagnosed according to the criteria recommended by the World Health Organization (1997). RESULT Caries experience as measured by the mean number of decayed, missing and filled primary teeth (dmft) of the 4-, 5-, and 6-year-old children were found to be 0.9, 1.8, and 3.3 respectively. Overall, 61% of the children had a zero dmft score. Children born in Mainland China had a higher mean dmft score (4.6) than those born in Hong Kong (1.4). Statistically significant correlations were found between the children's dental caries status and their oral health practices as well as their socio-economic background. Parents' education level, dental knowledge and attitudes were also associated with the children's dental caries experience. CONCLUSION In general, the caries status of Hong Kong Chinese preschool children was similar to that of children in industrialised countries and was better than that of children in the nearby areas. However, special dental programmes should be made available to children from lower socio-economic classes and new immigrants from Mainland China because they are the high risk groups for caries in Hong Kong.
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Affiliation(s)
- C H Chu
- Faculty of Dentistry, The University of Hong Kong, China
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