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Wu H, Yip A, Long J, Zhang J, Ng MK. Simplicial Complex Neural Networks. IEEE Trans Pattern Anal Mach Intell 2024; 46:561-575. [PMID: 37831564 DOI: 10.1109/tpami.2023.3323624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2023]
Abstract
Graph-structured data, where nodes exhibit either pair-wise or high-order relations, are ubiquitous and essential in graph learning. Despite the great achievement made by existing graph learning models, these models use the direct information (edges or hyperedges) from graphs and do not adopt the underlying indirect information (hidden pair-wise or high-order relations). To address this issue, in this paper, we propose a general framework named Simplicial Complex Neural (SCN) network, in which we construct a simplicial complex based on the direct and indirect graph information from a graph so that all information can be employed in the complex network learning. Specifically, we learn representations of simplices by aggregating and integrating information from all the simplices together via layer-by-layer simplicial complex propagation. In consequence, the representations of nodes, edges, and other high-order simplices are obtained simultaneously and can be used for learning purposes. By making use of block matrix properties, we derive the theoretical bound of the simplicial complex filter learnt by the propagation and establish the generalization error bound of the proposed simplicial complex network. We perform extensive experiments on node (0-simplex), edge (1-simplex), and triangle (2-simplex) classifications, and promising results demonstrate the performance of the proposed method is better than that of existing graph and hypergraph network approaches.
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2
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Yeung TSA, Cheung KC, Ng MK, See S, Yip A. Transfer Learning With Singular Value Decomposition of Multichannel Convolution Matrices. Neural Comput 2023; 35:1678-1712. [PMID: 37523461 DOI: 10.1162/neco_a_01608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 05/24/2023] [Indexed: 08/02/2023]
Abstract
The task of transfer learning using pretrained convolutional neural networks is considered. We propose a convolution-SVD layer to analyze the convolution operators with a singular value decomposition computed in the Fourier domain. Singular vectors extracted from the source domain are transferred to the target domain, whereas the singular values are fine-tuned with a target data set. In this way, dimension reduction is achieved to avoid overfitting, while some flexibility to fine-tune the convolution kernels is maintained. We extend an existing convolution kernel reconstruction algorithm to allow for a reconstruction from an arbitrary set of learned singular values. A generalization bound for a single convolution-SVD layer is devised to show the consistency between training and testing errors. We further introduce a notion of transfer learning gap. We prove that the testing error for a single convolution-SVD layer is bounded in terms of the gap, which motivates us to develop a regularization model with the gap as the regularizer. Numerical experiments are conducted to demonstrate the superiority of the proposed model in solving classification problems and the influence of various parameters. In particular, the regularization is shown to yield a significantly higher prediction accuracy.
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Affiliation(s)
| | - Ka Chun Cheung
- Department of Mathematics, Hong Kong Baptist University, Kowloon Tong, Hong Kong
- NVIDIA AI Technology Center, NVIDIA, Hong Kong 852, China
| | - Michael K Ng
- Institute of Data Science and Department of Mathematics, University of Hong Kong, Hong Kong 852, China
| | - Simon See
- NVIDIA AI Technology Center, NVIDIA, Singapore 65
- Centre for Computational Science and Mathematical Modelling, Coventry University, Coventry, CV1 2TL, U.K
- Department of Computer Science and Engineering, Shanghai Jiao Tong University, Shanghai 65, China
- Department of Computer Science and Engineering, Mahindra University, Hyderabad 500043, India
| | - Andy Yip
- Department of Mathematics, University of Hong Kong, Pokfulam Road, Hong Kong 852, China
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3
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Li X, Ng MK, Xu G, Yip A. Multi-relational graph convolutional networks: Generalization guarantees and experiments. Neural Netw 2023; 161:343-358. [PMID: 36774871 DOI: 10.1016/j.neunet.2023.01.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 12/14/2022] [Accepted: 01/28/2023] [Indexed: 02/05/2023]
Abstract
The class of multi-relational graph convolutional networks (MRGCNs) is a recent extension of standard graph convolutional networks (GCNs) to handle heterogenous graphs with multiple types of relationships. MRGCNs have been shown to yield results superior than traditional GCNs in various machine learning tasks. The key idea is to introduce a new kind of convolution operated on tensors that can effectively exploit correlations exhibited in multiple relationships. The main objective of this paper is to analyze the algorithmic stability and generalization guarantees of MRGCNs to confirm the usefulness of MRGCNs. Our contributions are of three folds. First, we develop a matrix representation of various tensor operations underneath MRGCNs to simplify the analysis significantly. Next, we prove the uniform stability of MRGCNs and deduce the convergence of the generalization gap to support the usefulness of MRGCNs. The analysis sheds lights on the design of MRGCNs, for instance, how the data should be scaled to achieve the uniform stability of the learning process. Finally, we provide experimental results to demonstrate the stability results.
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Affiliation(s)
- Xutao Li
- Harbin Institute of Technology, Shenzhen, China.
| | - Michael K Ng
- The University of Hong Kong, Pokfulam Road, Hong Kong.
| | - Guangning Xu
- Harbin Institute of Technology, Shenzhen, China.
| | - Andy Yip
- The University of Hong Kong, Pokfulam Road, Hong Kong.
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4
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Chien WT, Bressington D, Yip A, Karatzias T. An international multi-site, randomized controlled trial of a mindfulness-based psycho-education group program for people with schizophrenia - CORRIGENDUM. Psychol Med 2023; 53:2720. [PMID: 36660915 PMCID: PMC10123818 DOI: 10.1017/s0033291723000041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- W T Chien
- Mental Health Care Research Group, School of Nursing, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, People's Republic of China
| | - D Bressington
- Mental Health Care Research Group, School of Nursing, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, People's Republic of China
| | - A Yip
- Mental Health Care Research Group, School of Nursing, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, People's Republic of China
| | - T Karatzias
- School of Health & Social Care, Edinburgh Napier University, Edinburgh, UK
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5
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Goodman S, Bagai A, Tan M, Andrade J, Spindler C, Malek-Marzban P, Har B, Yip A, Paniagua M, Elbarouni B, Bainey K, Paradis J, Maranda R, Cantor W, Doucet M, Khan R, Eisenberg M, Dery J, Schwalm J, Madan M, Lam A, Hameed A, Noronha L, Cieza T, Matteau A, Roth S, So D, Lavi S, Glanz A, Gao D, Tahiliani R, Welsh R, Kim H, Robinson S, Daneault B, Chong A, Le May M, Ahooja V, Gregoire J, Nadeau P, Laksman Z, Heilbron B, Bonakdar H, Yung D, Yan A. ANTITHROMBOTIC THERAPIES IN CANADIAN ATRIAL FIBRILLATION PATIENTS WITH CONCOMITANT CORONARY ARTERY DISEASE: INSIGHTS FROM THE CONNECT AF+PCI-I AND -II PROGRAMS. Can J Cardiol 2021. [DOI: 10.1016/j.cjca.2021.07.030] [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: 11/24/2022] Open
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6
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Chua ACY, Ong JJY, Malleret B, Suwanarusk R, Kosaisavee V, Zeeman AM, Cooper CA, Tan KSW, Zhang R, Tan BH, Abas SN, Yip A, Elliot A, Joyner CJ, Cho JS, Breyer K, Baran S, Lange A, Maher SP, Nosten F, Bodenreider C, Yeung BKS, Mazier D, Galinski MR, Dereuddre-Bosquet N, Le Grand R, Kocken CHM, Rénia L, Kyle DE, Diagana TT, Snounou G, Russell B, Bifani P. Robust continuous in vitro culture of the Plasmodium cynomolgi erythrocytic stages. Nat Commun 2019; 10:3635. [PMID: 31406175 PMCID: PMC6690977 DOI: 10.1038/s41467-019-11332-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [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: 10/22/2018] [Accepted: 06/28/2019] [Indexed: 01/19/2023] Open
Abstract
The ability to culture pathogenic organisms substantially enhances the quest for fundamental knowledge and the development of vaccines and drugs. Thus, the elaboration of a protocol for the in vitro cultivation of the erythrocytic stages of Plasmodium falciparum revolutionized research on this important parasite. However, for P. vivax, the most widely distributed and difficult to treat malaria parasite, a strict preference for reticulocytes thwarts efforts to maintain it in vitro. Cultivation of P. cynomolgi, a macaque-infecting species phylogenetically close to P. vivax, was briefly reported in the early 1980s, but not pursued further. Here, we define the conditions under which P. cynomolgi can be adapted to long term in vitro culture to yield parasites that share many of the morphological and phenotypic features of P. vivax. We further validate the potential of this culture system for high-throughput screening to prime and accelerate anti-P. vivax drug discovery efforts. Present understanding of Plasmodium vivax biology is hampered by its inability to grow in vitro. Here, the authors developed an in vitro culture of its simian counterpart, P. cynomolgi, which shares morphological and phenotypic similarities with P. vivax, initiating a new phase in vivax research.
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Affiliation(s)
- Adeline C Y Chua
- Singapore Immunology Network, A*STAR, Singapore, 138648, Singapore.,Department of Microbiology and Immunology, University of Otago, Dunedin, 9054, New Zealand.,Novartis Institute for Tropical Diseases, Singapore, 138670, Singapore
| | - Jessica Jie Ying Ong
- Department of Microbiology and Immunology, University of Otago, Dunedin, 9054, New Zealand.,Novartis Institute for Tropical Diseases, Singapore, 138670, Singapore
| | - Benoit Malleret
- Singapore Immunology Network, A*STAR, Singapore, 138648, Singapore.,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119077, Singapore
| | - Rossarin Suwanarusk
- Singapore Immunology Network, A*STAR, Singapore, 138648, Singapore.,Department of Microbiology and Immunology, University of Otago, Dunedin, 9054, New Zealand
| | - Varakorn Kosaisavee
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119077, Singapore.,Department of Parasitology and Entomology, Faculty of Public Health, Mahidol University, Bangkok, 10400, Thailand
| | - Anne-Marie Zeeman
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, 2288, The Netherlands
| | - Caitlin A Cooper
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, 30602, USA
| | - Kevin S W Tan
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119077, Singapore
| | - Rou Zhang
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119077, Singapore
| | - Bee Huat Tan
- Novartis Institute for Tropical Diseases, Singapore, 138670, Singapore
| | | | - Andy Yip
- Novartis Institute for Tropical Diseases, Singapore, 138670, Singapore
| | - Anne Elliot
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, 30602, USA
| | - Chester J Joyner
- Division of Pulmonary, Allergy, Critical Care & Sleep Medicine, Emory University, Atlanta, 30322, USA.,Emory Vaccine Center, Emory University, Atlanta, 30317, USA
| | - Jee Sun Cho
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119077, Singapore
| | - Kate Breyer
- Laboratory Animal Services, Scientific Operations, Novartis Institutes for Biomedical Research, East Hanover, 07936-1080, USA
| | - Szczepan Baran
- Laboratory Animal Services, Scientific Operations, Novartis Institutes for Biomedical Research, East Hanover, 07936-1080, USA
| | - Amber Lange
- Laboratory Animal Services, Scientific Operations, Novartis Institutes for Biomedical Research, East Hanover, 07936-1080, USA
| | - Steven P Maher
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, 30602, USA
| | - François Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, 63110, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine Research Building, University of Oxford Old Road Campus, Oxford, OX3 7FZ, UK
| | | | - Bryan K S Yeung
- Novartis Institute for Tropical Diseases, Singapore, 138670, Singapore
| | - Dominique Mazier
- Sorbonne Universités, UPMC Univ Paris 06, CR7, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), Paris, F-75013, France.,CIMI-Paris, INSERM, U1135, CNRS, Paris, F-75013, France
| | - Mary R Galinski
- Emory Vaccine Center, Emory University, Atlanta, 30317, USA.,Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, 30322, USA
| | - Nathalie Dereuddre-Bosquet
- CEA-Université Paris Sud 11-INSERM U1184, Immunology of Viral Infections and Autoimmune Diseases (IMVA), IDMIT Department, IBJF, DRF, Fontenay-aux-Roses, 92265, France
| | - Roger Le Grand
- CEA-Université Paris Sud 11-INSERM U1184, Immunology of Viral Infections and Autoimmune Diseases (IMVA), IDMIT Department, IBJF, DRF, Fontenay-aux-Roses, 92265, France
| | - Clemens H M Kocken
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, 2288, The Netherlands
| | - Laurent Rénia
- Singapore Immunology Network, A*STAR, Singapore, 138648, Singapore.,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119077, Singapore
| | - Dennis E Kyle
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, 30602, USA
| | - Thierry T Diagana
- Novartis Institute for Tropical Diseases, Singapore, 138670, Singapore
| | - Georges Snounou
- Sorbonne Universités, UPMC Univ Paris 06, CR7, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), Paris, F-75013, France.,CIMI-Paris, INSERM, U1135, CNRS, Paris, F-75013, France.,CEA-Université Paris Sud 11-INSERM U1184, Immunology of Viral Infections and Autoimmune Diseases (IMVA), IDMIT Department, IBJF, DRF, Fontenay-aux-Roses, 92265, France
| | - Bruce Russell
- Department of Microbiology and Immunology, University of Otago, Dunedin, 9054, New Zealand.
| | - Pablo Bifani
- Singapore Immunology Network, A*STAR, Singapore, 138648, Singapore. .,Novartis Institute for Tropical Diseases, Singapore, 138670, Singapore. .,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119077, Singapore. .,Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK.
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7
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Chua ACY, Ananthanarayanan A, Ong JJY, Wong JY, Yip A, Singh NH, Qu Y, Dembele L, McMillian M, Ubalee R, Davidson S, Tungtaeng A, Imerbsin R, Gupta K, Andolina C, Lee F, S-W Tan K, Nosten F, Russell B, Lange A, Diagana TT, Rénia L, Yeung BKS, Yu H, Bifani P. Hepatic spheroids used as an in vitro model to study malaria relapse. Biomaterials 2019; 216:119221. [PMID: 31195301 DOI: 10.1016/j.biomaterials.2019.05.032] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 05/19/2019] [Indexed: 12/27/2022]
Abstract
Hypnozoites are the liver stage non-dividing form of the malaria parasite that are responsible for relapse and acts as a natural reservoir for human malaria Plasmodium vivax and P. ovale as well as a phylogenetically related simian malaria P. cynomolgi. Our understanding of hypnozoite biology remains limited due to the technical challenge of requiring the use of primary hepatocytes and the lack of robust and predictive in vitro models. In this study, we developed a malaria liver stage model using 3D spheroid-cultured primary hepatocytes. The infection of primary hepatocytes in suspension led to increased infectivity of both P. cynomolgi and P. vivax infections. We demonstrated that this hepatic spheroid model was capable of maintaining long term viability, hepatocyte specific functions and cell polarity which enhanced permissiveness and thus, permitting for the complete development of both P. cynomolgi and P. vivax liver stage parasites in the infected spheroids. The model described here was able to capture the full liver stage cycle starting with sporozoites and ending in the release of hepatic merozoites capable of invading simian erythrocytes in vitro. Finally, we showed that this system can be used for compound screening to discriminate between causal prophylactic and cidal antimalarials activity in vitro for relapsing malaria.
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Affiliation(s)
- Adeline C Y Chua
- Novartis Institute for Tropical Diseases, 138670, Singapore; Department of Microbiology and Immunology, University of Otago, Dunedin 9054, New Zealand; Singapore Immunology Network (SIgN), A*STAR, 138648, Singapore
| | | | - Jessica Jie Ying Ong
- Novartis Institute for Tropical Diseases, 138670, Singapore; Department of Microbiology and Immunology, University of Otago, Dunedin 9054, New Zealand
| | | | - Andy Yip
- Novartis Institute for Tropical Diseases, 138670, Singapore
| | | | | | - Laurent Dembele
- Novartis Institute for Tropical Diseases, 138670, Singapore; Université des Sciences, des Techniques et des Technologies de Bamako (USTTB); MRTC - DEAP - Faculty of Pharmacy, Bamako, Mali
| | - Michael McMillian
- Invitrocue Pte Ltd. 138667, Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University Health System, 117597, Singapore
| | - Ratawan Ubalee
- Department of Entomology, Armed Forces Research Institute of Medical Science (AFRIMS), Bangkok 10400,Thailand
| | - Silas Davidson
- Department of Entomology, Armed Forces Research Institute of Medical Science (AFRIMS), Bangkok 10400,Thailand
| | - Anchalee Tungtaeng
- Department of Veterinary Medicine, Armed Forces Research Institute of Medical Science (AFRIMS), Bangkok 10400,Thailand
| | - Rawiwan Imerbsin
- Department of Veterinary Medicine, Armed Forces Research Institute of Medical Science (AFRIMS), Bangkok 10400,Thailand
| | - Kapish Gupta
- Mechanobiology Institute, National University of Singapore, 117411, Singapore
| | - Chiara Andolina
- Shoklo Malaria Research Unit (SMRU), Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Fan Lee
- Institute of Bioengineering and Nanotechnology, A*STAR, 138669, Singapore
| | - Kevin S-W Tan
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 119077, Singapore
| | - François Nosten
- Shoklo Malaria Research Unit (SMRU), Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Bruce Russell
- Department of Microbiology and Immunology, University of Otago, Dunedin 9054, New Zealand
| | - Amber Lange
- Laboratory Animal Services, Scientific Operations, Novartis Institutes for Biomedical Research, East Hanover, NJ, 07936-1080, USA
| | | | - Laurent Rénia
- Singapore Immunology Network (SIgN), A*STAR, 138648, Singapore; Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 119077, Singapore
| | | | - Hanry Yu
- Invitrocue Pte Ltd. 138667, Singapore; Mechanobiology Institute, National University of Singapore, 117411, Singapore; Institute of Bioengineering and Nanotechnology, A*STAR, 138669, Singapore
| | - Pablo Bifani
- Novartis Institute for Tropical Diseases, 138670, Singapore; Singapore Immunology Network (SIgN), A*STAR, 138648, Singapore; Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 119077, Singapore.
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8
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Gupta DK, Dembele L, Voorberg-van der Wel A, Roma G, Yip A, Chuenchob V, Kangwanrangsan N, Ishino T, Vaughan AM, Kappe SH, Flannery EL, Sattabongkot J, Mikolajczak S, Bifani P, Kocken CH, Diagana TT. The Plasmodium liver-specific protein 2 (LISP2) is an early marker of liver stage development. eLife 2019; 8:43362. [PMID: 31094679 PMCID: PMC6542585 DOI: 10.7554/elife.43362] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 05/13/2019] [Indexed: 02/06/2023] Open
Abstract
Plasmodium vivax hypnozoites persist in the liver, cause malaria relapse and represent a major challenge to malaria elimination. Our previous transcriptomic study provided a novel molecular framework to enhance our understanding of the hypnozoite biology (Voorberg-van der Wel A, et al., 2017). In this dataset, we identified and characterized the Liver-Specific Protein 2 (LISP2) protein as an early molecular marker of liver stage development. Immunofluorescence analysis of hepatocytes infected with relapsing malaria parasites, in vitro (P. cynomolgi) and in vivo (P. vivax), reveals that LISP2 expression discriminates between dormant hypnozoites and early developing parasites. We further demonstrate that prophylactic drugs selectively kill all LISP2-positive parasites, while LISP2-negative hypnozoites are only sensitive to anti-relapse drug tafenoquine. Our results provide novel biological insights in the initiation of liver stage schizogony and an early marker suitable for the development of drug discovery assays predictive of anti-relapse activity.
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Affiliation(s)
- Devendra Kumar Gupta
- Novartis Institute for Tropical Diseases, Emeryville, United States.,Novartis Institute for Tropical Diseases, Singapore, Singapore
| | - Laurent Dembele
- Novartis Institute for Tropical Diseases, Singapore, Singapore.,Faculty of Pharmacy, Université des Sciences, des Techniques et des Technologies de Bamako (USTTB), MRTC - DEAP, Bamako, Mali
| | | | - Guglielmo Roma
- Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Andy Yip
- Novartis Institute for Tropical Diseases, Singapore, Singapore
| | | | | | - Tomoko Ishino
- Graduate School of Medicine, Ehime University, Toon, Japan
| | | | - Stefan H Kappe
- Center for Infectious Disease Research, Seattle, United States
| | | | | | - Sebastian Mikolajczak
- Novartis Institute for Tropical Diseases, Emeryville, United States.,Center for Infectious Disease Research, Seattle, United States
| | - Pablo Bifani
- Novartis Institute for Tropical Diseases, Singapore, Singapore.,Singapore Immunology Network (SIgN), Singapore, Singapore.,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Clemens Hm Kocken
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, Netherlands
| | - Thierry Tidiane Diagana
- Novartis Institute for Tropical Diseases, Emeryville, United States.,Novartis Institute for Tropical Diseases, Singapore, Singapore
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9
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Yip A, Wethington E. CHRONIC NON-CANCER PAIN IN OLDER ADULTS: FROM BASIC RESEARCH TO APPLIED INTERVENTIONS. Innov Aging 2018. [DOI: 10.1093/geroni/igy023.3035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- A Yip
- Cornell University, Ithaca, New York
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10
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Yip A, Kruse J, Cary Reid M, Löckenhoff CE. AFFECTIVE GOALS AND CHRONIC PAIN MANAGEMENT: COMPARING ACTUAL, IDEAL, AND AVOIDED AFFECT. Innov Aging 2018. [DOI: 10.1093/geroni/igy023.3036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- A Yip
- Cornell University, Ithaca, New York, United States
| | - J Kruse
- Cornell University, Ithaca, NY, USA
| | - M Cary Reid
- Weill Cornell Medical College, New York, NY, USA
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11
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Affiliation(s)
- Siang Yong Tan
- Emeritus Professor of Medicine, John A Burns School of Medicine, University of Hawaii, Honolulu, USA
| | - A Yip
- Research carried out during senior medical student elective, John A Burns School of Medicine, University of Hawaii, Honolulu, USA
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12
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Legare J, Hassan A, Lutchmedial S, Yip A, MacLeod J, Leblanc H, Archer B, Ferguson D, Pelletier M, Forgie R, O'Brien A, Teskey R, Paddock V. HOW INTERVENTIONAL RADIOLOGY CAN ENHANCE THE PERFORMANCE OF A TAVI TEAM: NEW BRUNSWICK HEART CENTRE EXPERIENCE. Can J Cardiol 2018. [DOI: 10.1016/j.cjca.2018.07.145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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13
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Jenkins D, MacLeod J, Campbell T, Yip A, Legare J, Hassan A. THE IMPACT OF A COMPREHENSIVE TELEHEALTH HOME MONITORING AND TELEPHONE FOLLOW-UP PROGRAM ON 30-DAY RATES OF ADVERSE EVENTS FOLLOWING CARDIAC SURGERY. Can J Cardiol 2018. [DOI: 10.1016/j.cjca.2018.07.400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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14
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Boyd J, Cox J, Hassan A, Lutchmedial S, Yip A, Legare J. WHERE YOU LIVE IN NOVA SCOTIA CAN SIGNIFICANTLY IMPACT YOUR ACCESS TO LIFE SAVING CARDIAC CARE. Can J Cardiol 2017. [DOI: 10.1016/j.cjca.2017.07.229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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15
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Chien WT, Bressington D, Yip A, Karatzias T. An international multi-site, randomized controlled trial of a mindfulness-based psychoeducation group programme for people with schizophrenia. Psychol Med 2017; 47:2081-2096. [PMID: 28374661 PMCID: PMC5551382 DOI: 10.1017/s0033291717000526] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 02/01/2017] [Accepted: 02/02/2017] [Indexed: 11/18/2022]
Abstract
BACKGROUND We aimed to test a mindfulness-based psychoeducation group (MBPEG), v. a conventional psychoeducation group (CPEG) v. treatment as usual (TAU), in patients with schizophrenia-spectrum disorders over a 24-month follow-up. METHOD This single-blind, multi-site, pragmatic randomized controlled trial was conducted in six community treatment facilities across three countries (Hong Kong, mainland China and Taiwan). Patients were randomly allocated to one of the treatment conditions, and underwent 6 months of treatment. The primary outcomes were changes in duration of re-hospitalizations and mental state (Positive and Negative Syndrome Scale; PANSS) between baseline and 1 week, and 6, 12 and 18 months post-treatment. RESULTS A total of 300 patients in each country were assessed for eligibility between October 2013 and 30 April 2014, 38 patients per country (n = 342) were assigned to each treatment group and included in the intention-to-treat analysis. There was a significant difference in the length of re-hospitalizations between the three groups over 24 months (F 2,330 = 5.23, p = 0.005), with MBPEG participants having a shorter mean duration of re-hospitalizations than those in the other groups. The MBPEG and CPEG participants had significant differential changes in proportional odds ratios of complete remission (all individual PANSS items <3) over the 24-month follow-up (37 and 26%, respectively), as opposed to only 7.2% of the TAU group (χ2 = 8.9 and 8.0, p = 0.001 and 0.003, relative risk = 3.5 and 3.1, 95% confidence interval 2.0-7.2 and 1.6-6.3). CONCLUSIONS Compared with TAU and CPEG, MBPEG improves remission and hospitalization rates of people with schizophrenia spectrum disorders over 24 months.
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Affiliation(s)
- W. T. Chien
- Mental Health Care Research Group, School of Nursing, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, People's Republic of China
| | - D. Bressington
- Mental Health Care Research Group, School of Nursing, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, People's Republic of China
| | - A. Yip
- Mental Health Care Research Group, School of Nursing, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, People's Republic of China
| | - T. Karatzias
- School of Health & Social Care, Edinburgh Napier University, Edinburgh, UK
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16
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Zou B, Chan WL, Ding M, Leong SY, Nilar S, Seah PG, Liu W, Karuna R, Blasco F, Yip A, Chao A, Susila A, Dong H, Wang QY, Xu HY, Chan K, Wan KF, Gu F, Diagana TT, Wagner T, Dix I, Shi PY, Smith PW. Lead optimization of spiropyrazolopyridones: a new and potent class of dengue virus inhibitors. ACS Med Chem Lett 2015; 6:344-8. [PMID: 25878766 DOI: 10.1021/ml500521r] [Citation(s) in RCA: 54] [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] [Received: 12/16/2014] [Accepted: 02/02/2015] [Indexed: 12/24/2022] Open
Abstract
Spiropyrazolopyridone 1 was identified, as a novel dengue virus (DENV) inhibitor, from a DENV serotype 2 (DENV-2) high-throughput phenotypic screen. As a general trend within this chemical class, chiral resolution of the racemate revealed that R enantiomer was significantly more potent than the S. Cell-based lead optimization of the spiropyrazolopyridones focusing on improving the physicochemical properties is described. As a result, an optimal compound 14a, with balanced in vitro potency and pharmacokinetic profile, achieved about 1.9 log viremia reduction at 3 × 50 mg/kg (bid) or 3 × 100 mg/kg (QD) oral doses in the dengue in vivo mouse efficacy model.
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Affiliation(s)
- Bin Zou
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Wai Ling Chan
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Mei Ding
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Seh Yong Leong
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Shahul Nilar
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Peck Gee Seah
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Wei Liu
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Ratna Karuna
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Francesca Blasco
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Andy Yip
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Alex Chao
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Agatha Susila
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Hongping Dong
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Qing Yin Wang
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Hao Ying Xu
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Katherine Chan
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Kah Fei Wan
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Feng Gu
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Thierry T. Diagana
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Trixie Wagner
- Novartis Institute for Biomedical Research, Basel CH-4056, Switzerland
| | - Ina Dix
- Novartis Institute for Biomedical Research, Basel CH-4056, Switzerland
| | - Pei-Yong Shi
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
| | - Paul W. Smith
- Novartis Institute for Tropical Diseases, 10 Biopolis Road #05-01 Chromos, Singapore 138670, Singapore
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17
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Yip A, Al-Ahmari LS, Al-Ahmari TS, Brunner N, Jue J. ECHOCARDIOGRAPHIC ASSESSMENT OF PULMONARY VALVE MOTION IN PULMONARY HYPERTENSION. Can J Cardiol 2014. [DOI: 10.1016/j.cjca.2014.07.470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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18
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Fu Y, Yip A, Seah PG, Blasco F, Shi PY, Hervé M. Modulation of inflammation and pathology during dengue virus infection by p38 MAPK inhibitor SB203580. Antiviral Res 2014; 110:151-7. [PMID: 25131378 DOI: 10.1016/j.antiviral.2014.08.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 08/04/2014] [Accepted: 08/07/2014] [Indexed: 11/29/2022]
Abstract
Dengue virus (DENV) infection could lead to dengue fever (DF), dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). The disease outcome is controlled by both viral and host factors. Inflammation mediators from DENV-infected cells could contribute to increased vascular permeability, leading to severe DHF/DSS. Therefore, suppression of inflammation could be a potential therapeutic approach for treatment of dengue patients. In this context, p38 MAPK (mitogen-activated protein kinase) is a key enzyme that modulates the initiation of stress and inflammatory responses. Here we show that SB203580, a p38 MAPK inhibitor, suppressed the over production of DENV-induced pro-inflammatory mediators such as TNF-α, IL-8, and RANTES from human PBMCs, monocytic THP-1, and granulocyte KU812 cell lines. Oral administration of SB203580 in DENV-infected AG129 mice prevented hematocrit rise and lymphopenia, limited the development of inflammation and pathology (including intestine leakage), and significantly improved survival. These results, for the first time, have provided experimental evidence to imply that a short term inhibition of p38 MAPK may be beneficial to reduce disease symptoms in dengue patients.
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Affiliation(s)
- Yilong Fu
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | - Andy Yip
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | - Peck Gee Seah
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | - Francesca Blasco
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | - Pei-Yong Shi
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore.
| | - Maxime Hervé
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore.
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19
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Pelletier M, Paddock V, Leblanc H, Forgie R, Archer B, Ferguson D, Douglas G, Yip A, Hassan A. The Effect of Transcatheter Aortic Valve Implantation (TAVI) on Cognitive Function. Can J Cardiol 2013. [DOI: 10.1016/j.cjca.2013.07.360] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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20
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Kim YM, Gayen S, Kang C, Joy J, Huang Q, Chen AS, Wee JLK, Ang MJY, Lim HA, Hung AW, Li R, Noble CG, Lee LT, Yip A, Wang QY, Chia CSB, Hill J, Shi PY, Keller TH. NMR analysis of a novel enzymatically active unlinked dengue NS2B-NS3 protease complex. J Biol Chem 2013; 288:12891-900. [PMID: 23511634 DOI: 10.1074/jbc.m112.442723] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [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: 12/23/2022] Open
Abstract
The dengue virus (DENV) is a mosquito-borne pathogen responsible for an estimated 100 million human infections annually. The viral genome encodes a two-component trypsin-like protease that contains the cofactor region from the nonstructural protein NS2B and the protease domain from NS3 (NS3pro). The NS2B-NS3pro complex plays a crucial role in viral maturation and has been identified as a potential drug target. Using a DENV protease construct containing NS2B covalently linked to NS3pro via a Gly4-Ser-Gly4 linker ("linked protease"), previous x-ray crystal structures show that the C-terminal fragment of NS2B is remote from NS3pro and exists in an open state in the absence of an inhibitor; however, in the presence of an inhibitor, NS2B complexes with NS3pro to form a closed state. This linked enzyme produced NMR spectra with severe signal overlap and line broadening. To obtain a protease construct with a resolved NMR spectrum, we expressed and purified an unlinked protease complex containing a 50-residue segment of the NS2B cofactor region and NS3pro without the glycine linker using a coexpression system. This unlinked protease complex was catalytically active at neutral pH in the absence of glycerol and produced dispersed cross-peaks in a (1)H-(15)N heteronuclear single quantum correlation spectrum that enabled us to conduct backbone assignments using conventional techniques. In addition, titration with an active-site peptide aldehyde inhibitor and paramagnetic relaxation enhancement studies demonstrated that the unlinked DENV protease exists predominantly in a closed conformation in solution. This protease complex can serve as a useful tool for drug discovery against DENV.
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Affiliation(s)
- Young Mee Kim
- Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR), Singapore 138669
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21
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Liu Y, Yu J, Loo W, Chow L, Yip A. AOSOP12 PRELIMINARY STUDY OF SPECTRAL CT IMAGING IN DIFFERENTIATING PULMONARY SQUAMOUS CELL CARCINOMA AND SMALL CELL CARCINOMA. Eur J Cancer 2013. [DOI: 10.1016/s0959-8049(13)70012-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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22
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Abstract
Dengue fever is an emerging mosquito-borne flaviviral disease that threatens 2.5 billion people worldwide. No clinically approved vaccine and antiviral therapy are currently available to prevent or treat dengue virus (DENV) infection. Vertebrate animals other than primates are not normally infectable with DENV; however, a small animal dengue infection model would greatly facilitate the development of a vaccine or an antiviral therapy. To this end, a rodent model for DENV infection has been established in IFN-α/β and IFN-γ receptor-deficient (AG129) mice. This chapter describes the protocol for the DENV infection model in AG129 mice and testing of antiviral compounds by oral gavage or parenteral injection.
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Affiliation(s)
- Wouter Schul
- Department of Infectious Diseases, Novartis Institutes for Biomedical Research, Emeryville, CA, USA
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23
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Teoh EP, Kukkaro P, Teo EW, Lim APC, Tan TT, Yip A, Schul W, Aung M, Kostyuchenko VA, Leo YS, Chan SH, Smith KGC, Chan AHY, Zou G, Ooi EE, Kemeny DM, Tan GK, Ng JKW, Ng ML, Alonso S, Fisher D, Shi PY, Hanson BJ, Lok SM, MacAry PA. The structural basis for serotype-specific neutralization of dengue virus by a human antibody. Sci Transl Med 2012; 4:139ra83. [PMID: 22723463 DOI: 10.1126/scitranslmed.3003888] [Citation(s) in RCA: 182] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Dengue virus (DENV) is a mosquito-borne flavivirus that affects 2.5 billion people worldwide. There are four dengue serotypes (DENV1 to DENV4), and infection with one elicits lifelong immunity to that serotype but offers only transient protection against the other serotypes. Identification of the protective determinants of the human antibody response to DENV is a vital requirement for the design and evaluation of future preventative therapies and treatments. Here, we describe the isolation of a neutralizing antibody from a DENV1-infected patient. The human antibody 14c10 (HM14c10) binds specifically to DENV1. HM14c10 neutralizes the virus principally by blocking virus attachment; at higher concentrations, a post-attachment step can also be inhibited. In vivo studies show that the HM14c10 antibody has antiviral activity at picomolar concentrations. A 7 Å resolution cryoelectron microscopy map of Fab fragments of HM14c10 in a complex with DENV1 shows targeting of a discontinuous epitope that spans the adjacent surface of envelope protein dimers. As found previously, a human antibody specific for the related West Nile virus binds to a similar quaternary structure, suggesting that this could be an immunodominant epitope. These findings provide a structural and molecular context for durable, serotype-specific immunity to DENV infection.
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Affiliation(s)
- Ee Ping Teoh
- Department of Microbiology and Life Sciences Institute Immunology Programme, National University of Singapore, Singapore 117597, Singapore
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24
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Baker J, Brown K, Rajendiran E, Yip A, DeCoffe D, Dai C, Molcan E, Chittick SA, Ghosh S, Mahmoud S, Gibson DL. Medicinal lavender modulates the enteric microbiota to protect against Citrobacter rodentium-induced colitis. Am J Physiol Gastrointest Liver Physiol 2012; 303:G825-36. [PMID: 22821949 DOI: 10.1152/ajpgi.00327.2011] [Citation(s) in RCA: 25] [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] [Indexed: 01/31/2023]
Abstract
Inflammatory bowel disease, inclusive of Crohn's disease and ulcerative colitis, consists of immunologically mediated disorders involving the microbiota in the gastrointestinal tract. Lavender oil is a traditional medicine used to relieve many gastrointestinal disorders. The goal of this study was to examine the therapeutic effects of the essential oil obtained from a novel lavender cultivar, Lavandula×intermedia cultivar Okanagan lavender (OLEO), in a mouse model of acute colitis caused by Citrobacter rodentium. In colitic mice, oral gavage with OLEO resulted in less severe disease, including decreased morbidity and mortality, reduced intestinal tissue damage, and decreased infiltration of neutrophils and macrophages, with reduced levels of TNF-α, IFN-γ, IL-22, macrophage inflammatory protein-2α, and inducible nitric oxide synthase expression. This was associated with increased levels of regulatory T cell populations compared with untreated colitic mice. Recently, we demonstrated that the composition of the enteric microbiota affects susceptibility to C. rodentium-induced colitis. Here, we found that oral administration of OLEO induced microbiota enriched with members of the phylum Firmicutes, including segmented filamentous bacteria, which are known to protect against the damaging effects of C. rodentium. Additionally, during infection, OLEO treatment promoted the maintenance of microbiota loads, with specific increases in Firmicutes bacteria and decreases in γ-Proteobacteria. We observed that Firmicutes bacteria were intimately associated with the apical region of the intestinal epithelial cells during infection, suggesting that their protective effect was through contact with the gut wall. Finally, we show that OLEO inhibited C. rodentium growth and adherence to Caco-2 cells, primarily through the activities of 1,8-cineole and borneol. These results indicate that while OLEO promoted Firmicutes populations, it also controlled pathogen load through antimicrobial activity. Overall, our results reveal that OLEO can protect against colitis through the microbial-immunity nexus and that a pharmacological agent, in this case OLEO, alters the normal enteric microbiota.
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Affiliation(s)
- J Baker
- Department of Biology, University of British Columbia Okanagan, ASC 368, 3333 Univ. Way, The Irving K. Barber School of Arts and Sciences, Kelowna, BC, Canada V1V 1V7
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25
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Baker J, Brown K, Rajendiran E, Yip A, DeCoffe D, Dai C, Molcan E, Chittick SA, Ghosh S, Mahmoud S, Gibson DL. Medicinal lavender modulates the enteric microbiota to protect against Citrobacter rodentium-induced colitis. Am J Physiol Gastrointest Liver Physiol 2012. [PMID: 22821949 DOI: 10.1152/ajpgi.00327] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Inflammatory bowel disease, inclusive of Crohn's disease and ulcerative colitis, consists of immunologically mediated disorders involving the microbiota in the gastrointestinal tract. Lavender oil is a traditional medicine used to relieve many gastrointestinal disorders. The goal of this study was to examine the therapeutic effects of the essential oil obtained from a novel lavender cultivar, Lavandula×intermedia cultivar Okanagan lavender (OLEO), in a mouse model of acute colitis caused by Citrobacter rodentium. In colitic mice, oral gavage with OLEO resulted in less severe disease, including decreased morbidity and mortality, reduced intestinal tissue damage, and decreased infiltration of neutrophils and macrophages, with reduced levels of TNF-α, IFN-γ, IL-22, macrophage inflammatory protein-2α, and inducible nitric oxide synthase expression. This was associated with increased levels of regulatory T cell populations compared with untreated colitic mice. Recently, we demonstrated that the composition of the enteric microbiota affects susceptibility to C. rodentium-induced colitis. Here, we found that oral administration of OLEO induced microbiota enriched with members of the phylum Firmicutes, including segmented filamentous bacteria, which are known to protect against the damaging effects of C. rodentium. Additionally, during infection, OLEO treatment promoted the maintenance of microbiota loads, with specific increases in Firmicutes bacteria and decreases in γ-Proteobacteria. We observed that Firmicutes bacteria were intimately associated with the apical region of the intestinal epithelial cells during infection, suggesting that their protective effect was through contact with the gut wall. Finally, we show that OLEO inhibited C. rodentium growth and adherence to Caco-2 cells, primarily through the activities of 1,8-cineole and borneol. These results indicate that while OLEO promoted Firmicutes populations, it also controlled pathogen load through antimicrobial activity. Overall, our results reveal that OLEO can protect against colitis through the microbial-immunity nexus and that a pharmacological agent, in this case OLEO, alters the normal enteric microbiota.
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Affiliation(s)
- J Baker
- Department of Biology, University of British Columbia Okanagan, ASC 368, 3333 Univ. Way, The Irving K. Barber School of Arts and Sciences, Kelowna, BC, Canada V1V 1V7
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Chang J, Schul W, Yip A, Xu X, Guo JT, Block TM. Competitive inhibitor of cellular α-glucosidases protects mice from lethal dengue virus infection. Antiviral Res 2011; 92:369-71. [PMID: 21854808 DOI: 10.1016/j.antiviral.2011.08.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Revised: 07/07/2011] [Accepted: 08/03/2011] [Indexed: 10/17/2022]
Abstract
Dengue virus infection causes diseases in people, ranging from the acute febrile illness dengue fever, to life-threatening dengue hemorrhagic fever/dengue shock syndrome. We previously reported that a host cellular α-glucosidases I and II inhibitor, imino sugar CM-10-18, potently inhibited dengue virus replication in cultured cells, and significantly reduced viremia in dengue virus infected AG129 mice. In this report we show that CM-10-18 also significantly protects mice from death and/or disease progress in two mouse models of lethal dengue virus infection. Our results thus provide a strong support for the development of CM-10-18 or its derivatives as antiviral agents to treat servere dengue virus infections.
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Affiliation(s)
- Jinhong Chang
- Drexel Institute for Biotechnology and Virology Research, Department of Microbiology and Immunology, Drexel University College of Medicine, Doylestown, PA 18902, United States.
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27
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Chang J, Schul W, Butters TD, Yip A, Liu B, Goh A, Lakshminarayana SB, Alonzi D, Reinkensmeier G, Pan X, Qu X, Weidner JM, Wang L, Yu W, Borune N, Kinch MA, Rayahin JE, Moriarty R, Xu X, Shi PY, Guo JT, Block TM. Combination of α-glucosidase inhibitor and ribavirin for the treatment of dengue virus infection in vitro and in vivo. Antiviral Res 2010; 89:26-34. [PMID: 21073903 DOI: 10.1016/j.antiviral.2010.11.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 10/26/2010] [Accepted: 11/03/2010] [Indexed: 10/18/2022]
Abstract
Cellular α-glucosidases I and II are enzymes that sequentially trim the three terminal glucoses in the N-linked oligosaccharides of viral envelope glycoproteins. This process is essential for the proper folding of viral glycoproteins and subsequent assembly of many enveloped viruses, including dengue virus (DENV). Imino sugars are substrate mimics of α-glucosidases I and II. In this report, we show that two oxygenated alkyl imino sugar derivatives, CM-9-78 and CM-10-18, are potent inhibitors of both α-glucosidases I and II in vitro and in treated animals, and efficiently inhibit DENV infection of cultured human cells. Pharmacokinetic studies reveal that both compounds are well tolerated at doses up to 100mg/kg in rats and have favorable pharmacokinetic properties and bioavailability in mice. Moreover, we showed that oral administration of either CM-9-78 or CM-10-18 reduces the peak viremia of DENV in mice. Interestingly, while treatment of DENV infected mice with ribavirin alone did not reduce the viremia, combination therapy of ribavirin with sub-effective dose of CM-10-18 demonstrated a significantly enhanced antiviral activity, as indicated by a profound reduction of the viremia. Our findings thus suggest that combination therapy of two broad-spectrum antiviral agents may provide a practically useful approach for the treatment of DENV infection.
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Affiliation(s)
- Jinhong Chang
- Drexel Institute for Biotechnology and Virology Research, Department of Microbiology and Immunology, Drexel University College of Medicine, 3805 Old Easton Road, Doylestown, PA 18902, United States.
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Keage HAD, Matthews FE, Yip A, Gao L, McCracken C, McKeith IG, Rubinsztein DC, Brayne C. APOE and ACE polymorphisms and dementia risk in the older population over prolonged follow-up: 10 years of incidence in the MRC CFA Study. Age Ageing 2010; 39:104-11. [PMID: 19939808 PMCID: PMC2794361 DOI: 10.1093/ageing/afp210] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Background: dementia risk conferred by apolipoprotein-E (APOE) and angiotensin-1-converting enzyme (ACE) polymorphisms have been reported for the MRC Cognitive Function and Ageing Study (CFAS) at 6-year follow-up. We concentrate on incident dementia risk over 10 years. Methods: participants come from MRC CFAS, a multi-centre longitudinal population-based study of ageing in England and Wales. Three follow-up waves of data collection were used: 2, 6 and 10 years. Logistic regressions were undertaken to investigate associations between APOE (n = 955) and ACE (n = 856) alleles/genotypes and incident dementia. Two types of control groups were used: non-demented and highly functioning non-demented. Results were back-weighted. Results: compared to APOE ε3, ε2 conferred protection of odds ratio (OR) = 0.3 (95% confidence interval, CI = 0.1–0.6) and ε4 risk of OR = 2.9 (95% CI = 1.7–4.9) for incident dementia. Compared to ε3/ε3, the ε3/ε4 and ε4/ε4 genotypes conferred risks of OR = 3.6 (95% CI = 1.8–7.3) and OR = 7.9 (95% CI = 1.6–39.2), respectively. The ε3/ε2 genotype protected against dementia (OR = 0.2, 95% CI = 0.1–0.7), and ε2/ε2 had a similar protective effect but with wide CIs (OR = 0.3, 95% CI = 0.1–1.7). Restricting the control group accentuated these differentials. The effects of ACE alleles/genotypes on incident dementia risk were small. Conclusions:APOE but not ACE is associated with late-onset incident dementia in the population. Using longer term follow-up with proper adjustment for attrition and incident cases increases estimates of risk.
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Affiliation(s)
- H A D Keage
- Department of Public Health and Primary Care, University of Cambridge, UK.
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Han HS, Reis I, Kuroi K, Toi M, Suzuki E, Syme R, Chow L, Yip A, Zhao W, Nimmagadda R, Gluck S. Racial differences in acute toxicities of FEC 100 chemotherapy in patients with breast cancer. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.e11515] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e11515 Background: Racial disparities in breast cancer outcomes are attributed to differences in baseline tumor characteristics, stage, and socioeconomic factors. However, little is known about racial differences in treatment-related toxicities. We hypothesized that racial and ethnic differences result in differential tolerance to chemotherapy and possibly compromise to the dose intensity of adjuvant/neoadjuvant chemotherapy. Methods: Data was collected from 4 international collaborating centers (University of Miami, JBCRG (Japan Breast Cancer Research Group), University of Hong Kong, and Tom Baker Cancer Center) at which patients of different ethnic background have been treated for non metastatic breast cancer with same adjuvant or neoadjuvant chemotherapy of FEC 100: fluorouracil 500 mg/m2, epirubicin 100 mg/m2, and cyclophosphamide 100 mg/m2). Racial/ethnic differences in toxicities were assessed by first episode of grade 2 or higher toxicity. Analysis of data was performed at the University of Miami. Results: Treatment-related toxicities are compared according to four race/ethnicity groups (120 Caucasian from USA and Canada (C), 16 African American (AA) from USA and Canada, 141 Japanese Asian (JA), and 23 Asian from Hong Kong (HKA)) (Table). JA and HKA had a significant higher rate of grade 3 or higher toxicity compared with C or AA women; 65%, 61%, 28%, and 31% respectively. However, there were no significant differences in chemotherapy dose intensity or density across the 4 race/ethnicity groups. Conclusions: This unique study noted racial differences in acute toxicity in women with breast cancer who were treated with FEC 100 chemotherapy. However, there are several limitations including the retrospective nature of our study, differences in practice across four countries, and different number of patients available for comparison. This study is ongoing and further statistical analyses are planned when a larger sample size is reached. [Table: see text] No significant financial relationships to disclose.
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Affiliation(s)
- H. S. Han
- Moffitt Cancer Center, Tampa, FL; University of Miami, Miami, FL; Tokyo Metropolitan Komagome Hospital, Tokyo, Japan; Kyoto university, Kyoto, Japan; Komagome Hospital, Tokyo, Japan; Alberta Cancer Board, Calgary, AB, Canada; Organisation for Oncology and Translational Research, Hong Kong, China; Organisation for Oncology and Research, Hong Kong, China; Apollo Speciality Hospital, Chennai, India
| | - I. Reis
- Moffitt Cancer Center, Tampa, FL; University of Miami, Miami, FL; Tokyo Metropolitan Komagome Hospital, Tokyo, Japan; Kyoto university, Kyoto, Japan; Komagome Hospital, Tokyo, Japan; Alberta Cancer Board, Calgary, AB, Canada; Organisation for Oncology and Translational Research, Hong Kong, China; Organisation for Oncology and Research, Hong Kong, China; Apollo Speciality Hospital, Chennai, India
| | - K. Kuroi
- Moffitt Cancer Center, Tampa, FL; University of Miami, Miami, FL; Tokyo Metropolitan Komagome Hospital, Tokyo, Japan; Kyoto university, Kyoto, Japan; Komagome Hospital, Tokyo, Japan; Alberta Cancer Board, Calgary, AB, Canada; Organisation for Oncology and Translational Research, Hong Kong, China; Organisation for Oncology and Research, Hong Kong, China; Apollo Speciality Hospital, Chennai, India
| | - M. Toi
- Moffitt Cancer Center, Tampa, FL; University of Miami, Miami, FL; Tokyo Metropolitan Komagome Hospital, Tokyo, Japan; Kyoto university, Kyoto, Japan; Komagome Hospital, Tokyo, Japan; Alberta Cancer Board, Calgary, AB, Canada; Organisation for Oncology and Translational Research, Hong Kong, China; Organisation for Oncology and Research, Hong Kong, China; Apollo Speciality Hospital, Chennai, India
| | - E. Suzuki
- Moffitt Cancer Center, Tampa, FL; University of Miami, Miami, FL; Tokyo Metropolitan Komagome Hospital, Tokyo, Japan; Kyoto university, Kyoto, Japan; Komagome Hospital, Tokyo, Japan; Alberta Cancer Board, Calgary, AB, Canada; Organisation for Oncology and Translational Research, Hong Kong, China; Organisation for Oncology and Research, Hong Kong, China; Apollo Speciality Hospital, Chennai, India
| | - R. Syme
- Moffitt Cancer Center, Tampa, FL; University of Miami, Miami, FL; Tokyo Metropolitan Komagome Hospital, Tokyo, Japan; Kyoto university, Kyoto, Japan; Komagome Hospital, Tokyo, Japan; Alberta Cancer Board, Calgary, AB, Canada; Organisation for Oncology and Translational Research, Hong Kong, China; Organisation for Oncology and Research, Hong Kong, China; Apollo Speciality Hospital, Chennai, India
| | - L. Chow
- Moffitt Cancer Center, Tampa, FL; University of Miami, Miami, FL; Tokyo Metropolitan Komagome Hospital, Tokyo, Japan; Kyoto university, Kyoto, Japan; Komagome Hospital, Tokyo, Japan; Alberta Cancer Board, Calgary, AB, Canada; Organisation for Oncology and Translational Research, Hong Kong, China; Organisation for Oncology and Research, Hong Kong, China; Apollo Speciality Hospital, Chennai, India
| | - A. Yip
- Moffitt Cancer Center, Tampa, FL; University of Miami, Miami, FL; Tokyo Metropolitan Komagome Hospital, Tokyo, Japan; Kyoto university, Kyoto, Japan; Komagome Hospital, Tokyo, Japan; Alberta Cancer Board, Calgary, AB, Canada; Organisation for Oncology and Translational Research, Hong Kong, China; Organisation for Oncology and Research, Hong Kong, China; Apollo Speciality Hospital, Chennai, India
| | - W. Zhao
- Moffitt Cancer Center, Tampa, FL; University of Miami, Miami, FL; Tokyo Metropolitan Komagome Hospital, Tokyo, Japan; Kyoto university, Kyoto, Japan; Komagome Hospital, Tokyo, Japan; Alberta Cancer Board, Calgary, AB, Canada; Organisation for Oncology and Translational Research, Hong Kong, China; Organisation for Oncology and Research, Hong Kong, China; Apollo Speciality Hospital, Chennai, India
| | - R. Nimmagadda
- Moffitt Cancer Center, Tampa, FL; University of Miami, Miami, FL; Tokyo Metropolitan Komagome Hospital, Tokyo, Japan; Kyoto university, Kyoto, Japan; Komagome Hospital, Tokyo, Japan; Alberta Cancer Board, Calgary, AB, Canada; Organisation for Oncology and Translational Research, Hong Kong, China; Organisation for Oncology and Research, Hong Kong, China; Apollo Speciality Hospital, Chennai, India
| | - S. Gluck
- Moffitt Cancer Center, Tampa, FL; University of Miami, Miami, FL; Tokyo Metropolitan Komagome Hospital, Tokyo, Japan; Kyoto university, Kyoto, Japan; Komagome Hospital, Tokyo, Japan; Alberta Cancer Board, Calgary, AB, Canada; Organisation for Oncology and Translational Research, Hong Kong, China; Organisation for Oncology and Research, Hong Kong, China; Apollo Speciality Hospital, Chennai, India
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Hibberd ML, Ling L, Tolfvenstam T, Mitchell W, Wong C, Kuznetsov VA, George J, Ong SH, Ruan Y, Wei CL, Gu F, Fink J, Yip A, Liu W, Schreiber M, Vasudevan SG. A Genomics Approach to Understanding Host Response during Dengue Infection. ACTA ACUST UNITED AC 2008; 277:206-14; discussion 214-7, 251-3. [PMID: 17319164 DOI: 10.1002/0470058005.ch15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Dengue infection results in a wide clinical spectrum, ranging from asymptomatic, through fever (DF), to the life threatening complications haemorrhagic fever (DHF) and shock syndrome (DSS). Although we now understand that factors such as repeat infections and the type or magnitude of the host response are important in determining severity, the mechanisms of these actions remain largely unknown. Understanding this host-pathogen interaction may enable outcome prediction and new therapy options. Developments in biology now allow a 'systems approach' to be applied to this problem, utilizing whole genomes of both human and virus, in vitro and in vivo to enable a more complete picture of their interplay to be built up. We have developed a chip-based approach to viral sequencing, to increase efficiency and enable large numbers ofgenomes to be completed, together with a web-based interpretation tool. We have also applied human whole genome expression arrays (24000 genes) to characterize the types of host response made to infection and plan to investigate the role of host variation using human whole genome genetic association studies in the future. These technologies have identified novel host pathways involved in viral replication in vitro, and also host immune responses, such as the interferon signalling pathway, that are influenced by viral sequence. This data will be further refined through interlinking with similar data obtained from a large study of dengue patients, initiated in Singapore, that is able to look at the early host response to infection.
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Hung W, Chan C, Chan L, Mak K, Fung A, Iu P, Lam H, Lau Y, Yip A. Measurement of residual tumour size after neo-adjuvant chemotherapy for locally advanced breast cancer: accuracy of clinical examination, mammography, ultrasound and magnetic resonance imaging. EJC Suppl 2006. [DOI: 10.1016/s1359-6349(06)80399-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Farrer L, Friedland R, Bowirrat A, Green R, Yip A, Inzelberg R, Baldwin C. S2-01-02 Using a genetic approach to understand the vascular basis of Alzheimer disease. Neurobiol Aging 2004. [DOI: 10.1016/s0197-4580(04)80080-0] [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: 11/17/2022]
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Taylor A, Ezquerra M, Bagri G, Yip A, Goumidi L, Cottel D, Easton D, Evans JG, Xuereb J, Cairns NJ, Amouyel P, Chartier-Harlin MC, Brayne C, Rubinsztein DC. Alzheimer disease is not associated with polymorphisms in the angiotensinogen and renin genes. Am J Med Genet 2001; 105:761-4. [PMID: 11803527 DOI: 10.1002/ajmg.10044] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Hypertension has been implicated as a risk factor for Alzheimer disease (AD) and dementia in epidemiological studies of humans. It is thus possible that there are common genetic determinants for hypertension and AD. Epidemiological, clinical, and experimental data suggest that the renin-angiotensin-aldosterone system is a critical regulator of blood pressure. The presence of an MboI site in an RFLP in the renin gene and the Thr at the Met/Thr polymorphism at codon 235 (M235T) of the angiotensinogen gene have been reported to be associated with hypertension. These variants were studied in autopsy-confirmed AD cases and matched controls from the U.K. While no association was detected with the renin polymorphism, a weak deleterious effect was observed in cases homozygous for the angiotensinogen Thr allele. However, this association was not observed in a French cohort of clinically diagnosed AD cases and controls, suggesting that the initial observation was a type I error. Thus, these polymorphisms are unlikely to be associated with AD risk.
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Affiliation(s)
- A Taylor
- Department of Medical Genetics, Wellcome Trust Centre for Molecular Mechanisms in Disease, Cambridge Institute for Medical Research, Addenbrooke's Hospital, Cambridge, UK
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Abstract
OBJECTIVE The aim of this study was to investigate the feasibility of using DNA in the circulation as a diagnostic tool for cervical cancer. METHODS We used PCR followed by Southern hybridization to detect human papillomavirus (HPV) DNA in serum samples taken from patients of cervical cancer before treatment. RESULTS A total of 60 samples were analyzed. In a set of 40 samples, without knowledge of the HPV DNA status in the corresponding cervical carcinomas, we could detect 8 (20%) positive samples, of which 7 (17.5%) were HPV 16 and 1 (2.5%) was HPV 18. In another set of 20 samples, known to be HPV 16 infected in the corresponding cervical carcinomas, we detected only 4 (20%) HPV-16-positive samples. The occurrence of HPV DNA in sera of cervical cancer patients seems sporadic. CONCLUSION The low incidence indicates that serum HPV DNA has limited application in the diagnosis of cervical cancer.
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Affiliation(s)
- V W Liu
- Department of Obstetrics and Gynaecology, The University of Hong Kong, Hong Kong
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Lee CH, Kwok OH, Fan K, Chau E, Yip A, Chow WH. Transcatheter closure of atrial septal defect using Amplatzer septal occluder in Chinese adults. Catheter Cardiovasc Interv 2001; 53:373-7. [PMID: 11458417 DOI: 10.1002/ccd.1184] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Amplatzer septal occluder (AGA Med. Co., USA) is a novel device for occlusion of atrial septal defect. We present our experience of transcatheter closure of atrial septal defects using Amplatzer septal occluder in 45 adult Chinese patients (age range 18-69 years). The size of atrial septal defect varied from 14-28 (23 +/- 4) mm. Cardiac catheterization revealed a pulmonary-to-systemic shunt ratio ranging from 1.4-2.8 (mean 2.0 +/- 0.4). The procedure was successful in 44 (98%) patients. Displacement of the device requiring surgical removal occurred in one (2%) patient and minor wound complication occurred in two (4%) patients. Total procedure time was 67 +/- 16 minutes and the fluoroscopy time was 25 +/- 8 min. Immediate post-procedure and pre-discharge echocardiography revealed complete abolition of shunt in 42 (93%) and trivial residual shunt in 3 (7%) patients. The average follow-up period was 16 +/- 6 months (range 2 months to 3 years) months. None of the patients had developed other major complication at follow-up. Cathet Cardiovasc Intervent 2001;52:373-377.
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Affiliation(s)
- C H Lee
- Department of Cardiology, Grantham Hospital, 125, Wong Chuk Hang Road, Aberdeen, Hong Kong SAR, China.
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37
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Taylor AE, Yip A, Brayne C, Easton D, Evans JG, Xuereb J, Cairns N, Esiri MM, Rubinsztein DC. Genetic association of an LBP-1c/CP2/LSF gene polymorphism with late onset Alzheimer's disease. J Med Genet 2001; 38:232-3. [PMID: 11283204 PMCID: PMC1734850 DOI: 10.1136/jmg.38.4.232] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES The only locus unequivocally associated with late onset Alzheimer's disease (AD) risk is APOE. However, this locus accounts for less than half the genetic variance. A recent study suggested that the A allele of the 3'UTR biallelic polymorphism in the LBP-1c/CP2/LSF gene was associated with reduced AD risk. Samples were diagnosed predominantly by clinical rather than pathological criteria. We have sought to replicate this finding in a series of necropsy confirmed, late onset AD cases and non-demented controls. METHODS The 3'UTR polymorphism in the LBP-1c/CP2/LSF gene was typed in 216 necropsy confirmed AD cases and 301 non-demented controls aged >73 years. RESULTS We found different LBP-1c/CP2/LSF allele distributions in our AD cases and controls (p=0.048); the A allele was associated with reduced AD risk. The allele and genotype frequencies observed in our cases and controls were similar to those previously reported. No significant effects emerged when the data were adjusted for age, sex, or apoE epsilon4 carrier status. CONCLUSIONS Our data support LBP-1c/CP2/LSF as a candidate gene/risk factor for AD and provide justification for future studies to investigate the role of this gene in Alzheimer's disease.
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Affiliation(s)
- A E Taylor
- Department of Medical Genetics, Wellcome Trust Centre for Molecular Mechanisms in Disease, Cambridge Institute for Medical Research, Wellcome/MRC Building, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2XY, UK
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38
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Murphy T, Yip A, Brayne C, Easton D, Evans JG, Xuereb J, Cairns N, Esiri MM, Rubinsztein DC. The BACE gene: genomic structure and candidate gene study in late-onset Alzheimer's disease. Neuroreport 2001; 12:631-4. [PMID: 11234778 DOI: 10.1097/00001756-200103050-00040] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Alzheimer's disease (AD) pathology is characterized by beta-amyloid plaques and neurofibrillary tangles. Studies of autosomal dominant early-onset AD mutations suggest that beta-amyloid overproduction is sufficient to cause AD. Recently, the BACE gene, which encodes beta-secretase, the rate limiting enzyme in beta-amyloid formation, has been identified. Since this gene is a strong candidate gene for late-onset AD because of its function, we have characterized its genomic organization and identified two polymorphisms. Neither of these polymorphisms were associated with AD risk in genetic association studies comparing autopsy-confirmed late-onset AD cases and age-matched non-demented controls. Thus, we find no evidence that this locus influences risk for late-onset AD.
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Affiliation(s)
- T Murphy
- Department of Medical Genetics, Wellcome Trust Centre for Molecular Mechanisms in Disease, Cambridge Institute for Medical Research, UK
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Abstract
OBJECTIVE Epidemiological studies in the 1980s have suggested that depression is rare in the Chinese population and there is no postpartum depression among Chinese women. However, subsequent small-scale studies of postpartum depression in China have yielded contradictory and inconsistent findings. Furthermore, after two decades of profound socioeconomic transformation, depression may no longer be rare in the contemporary population. The authors conducted a psychiatric epidemiological study among postpartum Chinese women using rigorous methodology and a representative sample. METHOD A total of 959 consecutive women were recruited at the antenatal clinic of a university hospital in Hong Kong. At 3 months postpartum, the prevalence and incidence rates of depression were measured with a two-phase design. The participants were first stratified by means of the 12-item General Health Questionnaire. Subsequently, all high scorers and 10% of low scorers were assessed with the nonpatient version of the Structured Clinical Interview for DSM-III-R. The 1-month and 3-month prevalence and incidence rates were estimated by using reverse weighting. RESULTS The 1-month prevalence rates for major and minor depression were 5.5% and 4.7%, respectively. At 3 months, the corresponding prevalence rates were 6.1% and 5.1%. Together, 13.5% of the participants suffered from one or more forms of psychiatric disorder in the first 3 months postpartum. CONCLUSIONS Postpartum depression is common among contemporary Chinese women. A universal postpartum depression-screening program would be useful for early detection. Our data suggest that depression may no longer be rare in the Chinese population.
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Affiliation(s)
- D Lee
- Department of Social Medicine, Harvard Medical School, Boston, USA.
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40
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Narain Y, Yip A, Murphy T, Brayne C, Easton D, Evans JG, Xuereb J, Cairns N, Esiri MM, Furlong RA, Rubinsztein DC. The ACE gene and Alzheimer's disease susceptibility. J Med Genet 2000; 37:695-7. [PMID: 10978362 PMCID: PMC1734696 DOI: 10.1136/jmg.37.9.695] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
A recent study suggested that the insertion (I) allele in intron 16 of the angiotensin converting enzyme gene (ACE) is associated with Alzheimer's disease (AD) risk. In our series of 239 necropsy confirmed late onset AD cases and 342 elderly non-demented controls aged >73 years, we found significantly different ACE genotype distributions in the case and control groups (p=0.007). Homozygotes for both the I and D alleles were associated with a higher risk compared to DI heterozygotes. While the APOE epsilon4 allele was strongly associated with AD risk in our series, we found no evidence for an interaction between the APOE and ACE loci. In addition, no interactions were observed between ACE and gender or age at death of the AD cases. A meta-analysis of all published reports (12 case-control series in total) suggested that both the II and ID ACE genotypes are associated with increased AD risk (odds ratio (OR) for II v DD 1.36, 95% confidence interval (CI)=1.13-1.63, OR for DI v DD 1.33, 95% CI=1.14-1.53, p=0.0002).
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Affiliation(s)
- Y Narain
- Department of Medical Genetics, Wellcome Trust Centre for Molecular Mechanisms in Disease, Cambridge Institute for Medical Research, Wellcome/MRC Building, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2XY, UK
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Abstract
OBJECTIVE To evaluate the efficacy and safety of excimer laser coronary angioplasty (ELCA) with adjunctive balloon angioplasty in patient with in-stent restenosis. METHODS ELCA was performed in 20 patients of instent restenosis. All patients were symptomatic and had class III-IV angina. ELCA was performed with the Spectranetics CVX-300 System. The laser catheter of Vittesse C (concentric) and E (eccentric) with diameter of 1.4-2.0 mm was used. RESULTS Laser catheter crossed all stenotic stents without difficulty. The lesion length was 4.6-51.2 mm, mean 20.7 +/- 13.7 mm, including 14 lesions > 10 mm. Laser treatment alone increased minimal lumen diameter (MLD) from 0.3 +/- 0.3 mm to 1.4 +/- 0.3 mm (P < 0.0001) and improved the diameter stenosis from 88.8% +/- 10.0% to 46.0% +/- 8.0% (P < 0.0001). Adjunctive balloon angioplasty further increased minimal lumen diameter to 2.3 +/- 0.7 mm and reduced diameter stenosis to 14.2% +/- 8.2% (P < 0.0001). At follow-up (1-17 months, mean 8.9 +/- 5.7 months), 17 (85%) patients had remained asymptomatic, 3 (15%) patients had mild to moderate exertional angina, 1 (5%) patient received CABG. CONCLUSION ELCA with adjunctive percutaneous transluminal coronary angioplasty (PTCA) is an efficient and safe technique to debulk tissue in the patient with in-stent restenosis. The incidence of procedural related complication was low and ELCA may be used as a good method for in-stent restenosis treatment.
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Affiliation(s)
- M Liu
- Grantham Hospital, Department of Cardiology, First Teaching Hospital, Beijing Medical University, Beijing 100034, China
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Abstract
BACKGROUND Breast cancer is the second most common cancer and cause of death in women from Hong Kong. The Well Women Clinic at Kwong Wah Hospital offers breast cancer screening (physical examination and mammography) for women over 40 years of age. METHODS Results of screening over a 2-year period revealed an overall malignancy detection rate of 2.6 per 1000 screens with a strong selection bias for symptomatic women. RESULTS Screening only slightly increased the proportion of stage I cancers detected; of the malignancies detected, a significant percentage were in situ cancers with doubtful effects on breast cancer mortality. Teamwork and communication were useful in keeping a low referral rate to the surgical clinic of 6.1%, as well as a low biopsy rate for mammographic abnormalities. CONCLUSIONS A re-evaluation of the real risk of breast cancer in young women together with the lack of proven value from screening has suggested a need for reconsideration of offering screening to women 40 years and over in Hong Kong.
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Affiliation(s)
- Y Lau
- Department of Surgery, Kwong Wah Hospital, Kowloon, Hong Kong.
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Kollen WJ, Midoux P, Erbacher P, Yip A, Roche AC, Monsigny M, Glick MC, Scanlin TF. Gluconoylated and glycosylated polylysines as vectors for gene transfer into cystic fibrosis airway epithelial cells. Hum Gene Ther 1996; 7:1577-86. [PMID: 8864758 DOI: 10.1089/hum.1996.7.13-1577] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
To provide an alternative to viral vectors for the transfer of genes into airway epithelial cells in cystic fibrosis (CF), a novel set of substituted polylysines were employed. Polylysine was partially neutralized by blocking a number of positively charged residues with gluconoyl groups. In addition, polylysine was substituted with sugar residues on a specified number of amino groups. Using the gluconoylated polylysine as vector, the pCMVLuc plasmid gave high expression of the reporter gene luciferase in immortalized CF/T43 cells. The luciferase activity was 75-fold greater in the presence of 100 microM chloroquine. Luciferase gene expression persisted at high levels for up to at least 120 hr following transfection. Glycosylated polylysines/pCMVLuc complexes were compared to the gluconoylated polylysine/pCMVLuc complex and beta-Gal-, alpha-Glc-, and Lac-substituted polylysines gave 320%, 300%, and 290%, respectively, higher expression of the reporter gene luciferase. Luciferase expression ranged from 35 to 2 ng of luciferase per milligram of cell protein in the order: beta-Gal = alpha-Glc = Lac > alpha-Gal = Rha = Man > beta-GalNAc > alpha-GalNAc = alpha-Fuc, suggesting that the transfection efficiency is sugar dependent. Most importantly, in primary cultures of both CF and non-CF airway epithelial cells grown from tracheal tissue explants, lactosylated polylysine gave uniformly high expression of luciferase. The glycosylated polylysines provide an attractive nonviral approach for the transfer of genes into airway epithelial cells.
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Affiliation(s)
- W J Kollen
- Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia 19104, USA
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44
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Chow WH, Chow TC, Yip A. Atrial septal puncture for balloon mitral valvotomy. Cathet Cardiovasc Diagn 1995; 36:380. [PMID: 8719403 DOI: 10.1002/ccd.1810360431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Affiliation(s)
- A Yip
- Government Surgical Unit, Queen Mary Hospital, Hong Kong
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Abstract
Injury to the prepuce is uncommon. A total of 32 patients were treated within a 3-year period. A difference in the aetiology between boys and adults was noted. Accidental injury to the prepuce occurred in 6 boys, with zipper injuries being the commonest among children. Coital and self-inflicted injuries accounted for 85% of adult cases. In patients with coital injuries, predisposing phimosis or a short frenulum was common.
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Affiliation(s)
- A Yip
- Department of Surgery, University of Hong Kong, Kwong Wah Hospital
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Abstract
The value of routine use of operative cholangiography was evaluated in 225 patients. In 65 patients (29%), there was one or more clinical or operative indications for common duct exploration and only 21 cases showed positive cholangiographic findings and were explored. There were four negative explorations in this group. In the remaining 160 patients who had no indication for common duct exploration, 157 had a normal cholangiogram and three had false positive cholangiographic findings and were explored unnecessarily. If operative cholangiography had been performed only on those patients with clinical or operative indications for common duct exploration, no ductal stone would have been missed. A selective use of operative cholangiography is advocated and the investigation should be restricted to those patients with clinical or operative indications for exploration of the common bile-duct.
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Affiliation(s)
- A Yip
- Department of Surgery, University of Hong Kong, Kwong Wah Hospital
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48
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Abstract
The hypophosphatemic (Hyp) mouse, a murine homologue of human X-linked hypophosphatemic rickets, is characterized by renal defects in brush border membrane phosphate transport and vitamin D3 metabolism. The present study was undertaken to examine whether elevated renal 25-hydroxyvitamin D3-24-hydroxylase activity in Hyp mice is associated with increased degradation of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] by side chain oxidation. Metabolites of 1,25(OH)2D3 were separated by HPLC on Zorbax SIL and identified by comparison with standards authenticated by mass spectrometry. Production of 1,24,25-trihydroxyvitamin D3, 24-oxo-1,25-dihydroxyvitamin D3, and 24-oxo-1,23,25-trihydroxyvitamin D3 was twofold greater in mitochondria from mutant Hyp/Y mice than from normal +/Y littermates. Enzyme activities, estimated by the sum of the three products synthesized per milligram mitochondrial protein under initial rate conditions, were used to estimate kinetic parameters. The apparent Vmax was significantly greater for mitochondria from Hyp/Y mice than from +/Y mice (0.607 +/- 0.064 vs. 0.290 +/- 0.011 pmol/mg per protein per min, mean +/- SEM, P less than 0.001), whereas the apparent Michaelis-Menten constant (Km) was similar in both genotypes (23 +/- 2 vs. 17 +/- 5 nM). The Km for 1,25(OH)2D3 was approximately 10-fold lower than that for 25-hydroxyvitamin D3 [25(OH)D3], indicating that 1,25(OH)2D3 is perhaps the preferred substrate under physiological conditions. In both genotypes, apparent Vmax for 25(OH)D3 was fourfold greater than that for 1,25(OH)2D3, suggesting that side chain oxidation of 25(OH)D3 may operate at pharmacological concentrations of substrate. The present results demonstrate that Hyp mice exhibit increased renal catabolism of 1,25(OH)2D3 and suggest that elevated degradation of vitamin D3 hormone may contribute significantly to the clinical phenotype in this disorder.
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Affiliation(s)
- H S Tenenhouse
- Medical Research Council (MRC) Genetics Group, McGill University-Montreal Children's Hospital Research Institute, Quebec, Canada
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Jones G, Yip A, Tenenhause HS. Side-chain oxidation of vitamin D3 in mouse kidney mitochondria: effect of the Hyp mutation and 1,25-dihydroxyvitamin D3 treatment. Biochem Cell Biol 1987; 65:853-9. [PMID: 2833907 DOI: 10.1139/o87-111] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Side-chain oxidation of vitamin D is an important degradative pathway. In the present study we compared the enzymes involved in side-chain oxidation in normal and Hyp mouse kidney. Homogenates of normal mouse kidney catalyze the conversion of 25-hydroxyvitamin D3 to 24,25-dihydroxyvitamin D3, 24-oxo-25-hydroxyvitamin D3 and 24-oxo-23,25-dihydroxyvitamin D3. After subcellular fractionation, total side-chain oxidative activity, estimated by the sum of the three products synthesized per milligram protein under initial rate conditions, coincided with the mitochondrial enzyme marker succinate-cytochrome-c reductase. Treatment of normal mice with 1,25-dihydroxyvitamin D3 (1.5 ng/g) resulted in an eightfold increase in mitochondrial enzyme activity, with no change in apparent Km but a significant rise in Vmax. With 24,25-dihydroxyvitamin D3 as the substrate, normal renal mitochondria produced 24-oxo-25-hydroxyvitamin D3 and 24-oxo-23,25-dihydroxyvitamin D3, and the synthesis of these metabolites could be increased sixfold by pretreatment with 1,25-dihydroxyvitamin D3. In the Hyp mouse, the side-chain oxidation pathway showed similar subcellular distribution of enzyme activity. However, product formation from 25-hydroxyvitamin D3 and 24,25-dihydroxyvitamin D3 was twofold greater in mutant than in normal mitochondria. Furthermore, 1,25-dihydroxyvitamin D3 pretreatment of Hyp mice resulted in a 3.4-fold increase over basal metabolism of both 25-hydroxyvitamin D3 and 24,25-dihydroxyvitamin D3. These results demonstrate that (i) kidneys from normal and Hyp mice possess basal and 1,25-dihydroxyvitamin D3 inducible enzyme system(s) in the mitochondrial fraction, which catalyze the side-chain oxidation of 25-hydroxyvitamin D3 and 24,25-dihydroxyvitamin D3, and (ii) the Hyp mutation appears to perturb the renal metabolism of both substrates only in the basal state.
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Affiliation(s)
- G Jones
- Department of Medicine, Queen's University, Kingston, Ont., Canada
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O'Leary TJ, Jones G, Yip A, Lohnes D, Cohanim M, Yendt ER. The effects of chloroquine on serum 1,25-dihydroxyvitamin D and calcium metabolism in sarcoidosis. N Engl J Med 1986; 315:727-30. [PMID: 3755800 DOI: 10.1056/nejm198609183151203] [Citation(s) in RCA: 115] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Although corticosteroids are effective in the treatment of hypercalciuria and hypercalcemia in chronic sarcoidosis, complications of their long-term use frequently limit therapy. We studied the efficacy of chloroquine in two patients with sarcoidosis who were unable to tolerate the dosage of corticosteroids required to control hypercalciuria and prevent the formation of renal stones. Over a three-year period, each patient received a 6-month and a 10-month course of oral chloroquine phosphate (500 mg per day) while continuing to receive corticosteroids at a fixed dose. Chloroquine therapy was associated with a significant reduction in levels of serum 1,25-dihydroxyvitamin D (1,25(OH)2D) and urinary calcium. We observed a direct correlation between serum 1,25-(OH)2D levels and 24-hour urinary calcium excretion, supporting the hypothesis that excessive serum 1,25-(OH)2D is responsible for the hypercalciuria in sarcoidosis. Serum levels of 25-hydroxyvitamin D (25-(OH)D) did not change with therapy, suggesting that chloroquine may act by inhibiting the conversion of 25-(OH)D to 1,25-(OH)2D. Current dosage guidelines and ophthalmologic-surveillance techniques, which allow chloroquine to be administered with little risk of retinopathy, should permit an expanded role for this agent in the treatment of the calcium abnormalities of sarcoidosis.
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