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Ho J, Heong V, Peng Yong W, Soo R, Ean Chee C, Wong A, Sundar R, Liang Thian Y, Gopinathan A, Yan Pang M, Koe P, Nathan Jeraj S, Pyar Soe P, Yar Soe M, Tang T, Ng MC, Tai DW, Tan TJ, Xu H, Chang H, Landesman Y, Shah J, Shacham S, Chin Lee S, Tan DS, Cher Goh B, Tan DS. A phase 1 study of the safety, pharmacokinetics and pharmacodynamics of escalating doses followed by dose expansion of the selective inhibitor of nuclear export (SINE) selinexor in Asian patients with advanced or metastatic malignancies. Ther Adv Med Oncol 2022; 14:17588359221087555. [PMID: 35432603 PMCID: PMC9008867 DOI: 10.1177/17588359221087555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 02/23/2022] [Indexed: 02/06/2023] Open
Abstract
Purpose: This phase 1 study aims to evaluate the tolerability and the recommended
phase 2 dose of selinexor in Asian patients with advanced or metastatic
malignancies. Experimental Design: A total of 105 patients with advanced malignancies were enrolled from two
sites in Singapore (National University Hospital and the National Cancer
Centre, Singapore) from 24 February 2014 to 14 January 2019. We investigated
four dosing schedules of selinexor in a 3 + 3 dose escalation design with an
additional Phase 1b expansion cohort. Adverse events were graded with the
NCI Common Terminology Criteria for Adverse Events v 4.03. Pharmacodynamic
assessments included nuclear cytoplasmic localization of p27, XPO1 cargo
proteins pre and post selinexor dosing and pharmacokinetic assessments were
conducted at doses between 40 and 60 mg/m2. Results: In our Asian patient cohort, dosing at 40 mg/m2 given 2 out of
3 weeks, was the most tolerable for our patients. At this dose level, grade
3 adverse events included fatigue (8%), hyponatremia (23%), vomiting (5%),
thrombocytopenia (5%), and anaemia (2%). Selinexor had a rapid oral
absorption with median Tmax of 2 h and no PK accumulation after
multiple doses of tested regimens. Complete responses were seen in two
lymphoma patients. Partial responses were noted in three diffuse large B
cell lymphomas, one Hodgkin’s lymphoma and thymic carcinoma patient,
respectively. Conclusion: Selinexor is tolerated by Asian patients at 40 mg/m2 twice a week
given 2 out of 3 weeks. A 1-week drug holiday was needed as our patients
could not tolerate the current approved continuous dosing regimens because
of persistent grade 3 fatigue, anorexia and hyponatremia.
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Affiliation(s)
- Jingshan Ho
- Department of Haematology and Oncology, National University Cancer Institute Singapore, Singapore
| | - Valerie Heong
- Department of Medical Oncology, Tan Tock Seng Hospital, Singapore
| | - Wei Peng Yong
- Department of Haematology and Oncology, National University Cancer Institute Singapore, Singapore
| | - Ross Soo
- Department of Haematology and Oncology, National University Cancer Institute Singapore, Singapore
| | - Cheng Ean Chee
- Department of Haematology and Oncology, National University Cancer Institute Singapore, Singapore
| | - Andrea Wong
- Department of Haematology and Oncology, National University Cancer Institute Singapore, Singapore
| | - Raghav Sundar
- Department of Haematology and Oncology, National University Cancer Institute Singapore, Singapore
| | - Yee Liang Thian
- Department of Radiology, National University Hospital, Singapore
| | - Anil Gopinathan
- Department of Radiology, National University Hospital, Singapore
| | - Mei Yan Pang
- Department of Haematology and Oncology, National University Cancer Institute Singapore, Singapore
| | - Priscillia Koe
- Department of Haematology and Oncology, National University Cancer Institute Singapore, Singapore
| | - Santhiay Nathan Jeraj
- Department of Haematology and Oncology, National University Cancer Institute Singapore, Singapore
| | - Phyu Pyar Soe
- Department of Haematology and Oncology, National University Cancer Institute Singapore, Singapore
| | - Mu Yar Soe
- Department of Haematology and Oncology, National University Cancer Institute Singapore, Singapore
| | - Tiffany Tang
- Department of Haematology-Oncology, National Cancer Centre, Singapore
| | - Matthew C.H. Ng
- Department of Haematology-Oncology, National Cancer Centre, Singapore
| | - David W.M. Tai
- Department of Haematology-Oncology, National Cancer Centre, Singapore
| | - Tira J.Y. Tan
- Department of Haematology-Oncology, National Cancer Centre, Singapore
| | - Hongmei Xu
- Karyopharm Therapeutics, Newton, MA, USA
| | - Hua Chang
- Karyopharm Therapeutics, Newton, MA, USA
| | | | - Jatin Shah
- Karyopharm Therapeutics, Newton, MA, USA
| | | | - Soo Chin Lee
- Department of Haematology and Oncology, National University Cancer Institute Singapore, Singapore Cancer Science Institute of Singapore, National University of Singapore, Singapore
| | - Daniel S.W. Tan
- Department of Haematology-Oncology, National Cancer Centre, Singapore
| | - Boon Cher Goh
- Department of Haematology and Oncology, National University Cancer Institute Singapore, Singapore Cancer Science Institute of Singapore, National University of Singapore, Singapore
| | - David S.P. Tan
- Department of Haematology and Oncology, National University Cancer Institute, NUHS Tower Block, Level 7, 1E Kent Ridge Road, Singapore 119228
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore Cancer Science Institute of Singapore, National University of Singapore, Singapore
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Tan TZ, Heong V, Ye J, Lim D, Low J, Choolani M, Scott C, Tan DS, Huang RY. Abstract PO-008: Know thy neighbor: Deciphering the intra-tumor heterogeneity in ovarian cancer with molecular assessment of subtype heterogeneity (MASH). Cancer Res 2020. [DOI: 10.1158/1538-7445.tumhet2020-po-008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The treatment of ovarian cancer has shifted away from the one-model-fit-all practice in this era of precision medicine. The current treatment for ovarian cancer has evolved to stratify patients based on histology and the mutation status. For instance, BRCA mutated non-mucinous ovarian cancer will be recommended for PARP inhibitor treatment in both the first- and second-line maintenance settings. However, beyond this concept of BRCAness, there still exists background heterogeneity at the transcriptomic level. In high grade serous carcinoma (HGSC), diverse molecular heterogeneity based on gene expression profiling has been shown by the Australian and the TCGA cohorts. This molecular heterogeneity has been demonstrated to be very robust and reproducible by a large-scale meta-analysis study consisting of 1,538 samples. At least 5 distinct gene-expression based molecular subtypes (GEMS) have been identified. The C1 and C5 subtype from the Tothill dataset corresponds to the Mesenchymal and Proliferative subtype from the TCGA dataset and the Mes and Stem-A subtype from the 1,538 meta-analysis dataset, respectively. These GEMS have been correlated with patient survival. The C1/Mesenchymal/Mes and C5/Proliferative/Stem-A GEMS are associated with poorer survival outcomes. Contentions have always been whether these GEMS could be used for patient stratification. To achieve this, a tool to decipher the intra-tumor heterogeneity (ITH) of GEMS is needed to ascertain whether a robust stratification scheme is feasible. Molecular assessment of subtype heterogeneity (MASH) was developed to comprehensively report on the composition of all transcriptomic subtypes within a tumor. Using MASH on 3431 ovarian cancer samples, correlation and association analyses with survival, metastasis and clinical outcomes were performed to assess the impact of GEMS composition as a surrogate for ITH. We identified that 30% of ovarian tumours consist of two or more GEMS. When biological features of the GEMS constituents were examined, we identified significant impact on clinical outcomes with the presence of poor prognostic GEMS (Mes or Stem-A). Poorer outcomes correlated with having higher degrees of poor prognostic GEMS populations within the tumor. Finally, a clinically applicable MASH assay using NanoString® technology was developed to comprehensively describe constituents of GEMS in ovarian cancer.
Citation Format: Tuan Zea Tan, Valerie Heong, Jieru Ye, Diana Lim, Jeffrey Low, Mahesh Choolani, Clare Scott, David S.P. Tan, Ruby Y.J. Huang. Know thy neighbor: Deciphering the intra-tumor heterogeneity in ovarian cancer with molecular assessment of subtype heterogeneity (MASH) [abstract]. In: Proceedings of the AACR Virtual Special Conference on Tumor Heterogeneity: From Single Cells to Clinical Impact; 2020 Sep 17-18. Philadelphia (PA): AACR; Cancer Res 2020;80(21 Suppl):Abstract nr PO-008.
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Ngoi NY, Tay D, Heong V, Thian YL, Ong PY, Ow SG, Jeyasekharan AD, Lim YW, Lim SE, Lee SC, Ng J, Low JJ, Ilancheran A, Koh SZ, Tan DS. Reversal of Bowel Obstruction With Platinum-Based Chemotherapy and Olaparib in Recurrent, Short Platinum-Free Interval, RAD51C Germline Mutation–Associated Ovarian Cancer. JCO Precis Oncol 2018; 2:1-8. [DOI: 10.1200/po.18.00008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Natalie Y.L. Ngoi
- Natalie Y.L. Ngoi, Valerie Heong, Pei Yi Ong, Samuel G.W. Ow, Anand D. Jeyasekharan, Yi Wan Lim, Siew Eng Lim, Soo Chin Lee, and David S.P. Tan, National University Cancer Institute; Darwin Tay, Valerie Heong, Anand D. Jeyasekharan, Soo Chin Lee, and David S.P. Tan, National University of Singapore; Yee Liang Thian, Joseph Ng, Jeffrey J.H. Low, Arunachalam Ilancheran, and Sharon Z.L. Koh, National University Hospital, Singapore, Republic of Singapore
| | - Darwin Tay
- Natalie Y.L. Ngoi, Valerie Heong, Pei Yi Ong, Samuel G.W. Ow, Anand D. Jeyasekharan, Yi Wan Lim, Siew Eng Lim, Soo Chin Lee, and David S.P. Tan, National University Cancer Institute; Darwin Tay, Valerie Heong, Anand D. Jeyasekharan, Soo Chin Lee, and David S.P. Tan, National University of Singapore; Yee Liang Thian, Joseph Ng, Jeffrey J.H. Low, Arunachalam Ilancheran, and Sharon Z.L. Koh, National University Hospital, Singapore, Republic of Singapore
| | - Valerie Heong
- Natalie Y.L. Ngoi, Valerie Heong, Pei Yi Ong, Samuel G.W. Ow, Anand D. Jeyasekharan, Yi Wan Lim, Siew Eng Lim, Soo Chin Lee, and David S.P. Tan, National University Cancer Institute; Darwin Tay, Valerie Heong, Anand D. Jeyasekharan, Soo Chin Lee, and David S.P. Tan, National University of Singapore; Yee Liang Thian, Joseph Ng, Jeffrey J.H. Low, Arunachalam Ilancheran, and Sharon Z.L. Koh, National University Hospital, Singapore, Republic of Singapore
| | - Yee Liang Thian
- Natalie Y.L. Ngoi, Valerie Heong, Pei Yi Ong, Samuel G.W. Ow, Anand D. Jeyasekharan, Yi Wan Lim, Siew Eng Lim, Soo Chin Lee, and David S.P. Tan, National University Cancer Institute; Darwin Tay, Valerie Heong, Anand D. Jeyasekharan, Soo Chin Lee, and David S.P. Tan, National University of Singapore; Yee Liang Thian, Joseph Ng, Jeffrey J.H. Low, Arunachalam Ilancheran, and Sharon Z.L. Koh, National University Hospital, Singapore, Republic of Singapore
| | - Pei Yi Ong
- Natalie Y.L. Ngoi, Valerie Heong, Pei Yi Ong, Samuel G.W. Ow, Anand D. Jeyasekharan, Yi Wan Lim, Siew Eng Lim, Soo Chin Lee, and David S.P. Tan, National University Cancer Institute; Darwin Tay, Valerie Heong, Anand D. Jeyasekharan, Soo Chin Lee, and David S.P. Tan, National University of Singapore; Yee Liang Thian, Joseph Ng, Jeffrey J.H. Low, Arunachalam Ilancheran, and Sharon Z.L. Koh, National University Hospital, Singapore, Republic of Singapore
| | - Samuel G.W. Ow
- Natalie Y.L. Ngoi, Valerie Heong, Pei Yi Ong, Samuel G.W. Ow, Anand D. Jeyasekharan, Yi Wan Lim, Siew Eng Lim, Soo Chin Lee, and David S.P. Tan, National University Cancer Institute; Darwin Tay, Valerie Heong, Anand D. Jeyasekharan, Soo Chin Lee, and David S.P. Tan, National University of Singapore; Yee Liang Thian, Joseph Ng, Jeffrey J.H. Low, Arunachalam Ilancheran, and Sharon Z.L. Koh, National University Hospital, Singapore, Republic of Singapore
| | - Anand D. Jeyasekharan
- Natalie Y.L. Ngoi, Valerie Heong, Pei Yi Ong, Samuel G.W. Ow, Anand D. Jeyasekharan, Yi Wan Lim, Siew Eng Lim, Soo Chin Lee, and David S.P. Tan, National University Cancer Institute; Darwin Tay, Valerie Heong, Anand D. Jeyasekharan, Soo Chin Lee, and David S.P. Tan, National University of Singapore; Yee Liang Thian, Joseph Ng, Jeffrey J.H. Low, Arunachalam Ilancheran, and Sharon Z.L. Koh, National University Hospital, Singapore, Republic of Singapore
| | - Yi Wan Lim
- Natalie Y.L. Ngoi, Valerie Heong, Pei Yi Ong, Samuel G.W. Ow, Anand D. Jeyasekharan, Yi Wan Lim, Siew Eng Lim, Soo Chin Lee, and David S.P. Tan, National University Cancer Institute; Darwin Tay, Valerie Heong, Anand D. Jeyasekharan, Soo Chin Lee, and David S.P. Tan, National University of Singapore; Yee Liang Thian, Joseph Ng, Jeffrey J.H. Low, Arunachalam Ilancheran, and Sharon Z.L. Koh, National University Hospital, Singapore, Republic of Singapore
| | - Siew Eng Lim
- Natalie Y.L. Ngoi, Valerie Heong, Pei Yi Ong, Samuel G.W. Ow, Anand D. Jeyasekharan, Yi Wan Lim, Siew Eng Lim, Soo Chin Lee, and David S.P. Tan, National University Cancer Institute; Darwin Tay, Valerie Heong, Anand D. Jeyasekharan, Soo Chin Lee, and David S.P. Tan, National University of Singapore; Yee Liang Thian, Joseph Ng, Jeffrey J.H. Low, Arunachalam Ilancheran, and Sharon Z.L. Koh, National University Hospital, Singapore, Republic of Singapore
| | - Soo Chin Lee
- Natalie Y.L. Ngoi, Valerie Heong, Pei Yi Ong, Samuel G.W. Ow, Anand D. Jeyasekharan, Yi Wan Lim, Siew Eng Lim, Soo Chin Lee, and David S.P. Tan, National University Cancer Institute; Darwin Tay, Valerie Heong, Anand D. Jeyasekharan, Soo Chin Lee, and David S.P. Tan, National University of Singapore; Yee Liang Thian, Joseph Ng, Jeffrey J.H. Low, Arunachalam Ilancheran, and Sharon Z.L. Koh, National University Hospital, Singapore, Republic of Singapore
| | - Joseph Ng
- Natalie Y.L. Ngoi, Valerie Heong, Pei Yi Ong, Samuel G.W. Ow, Anand D. Jeyasekharan, Yi Wan Lim, Siew Eng Lim, Soo Chin Lee, and David S.P. Tan, National University Cancer Institute; Darwin Tay, Valerie Heong, Anand D. Jeyasekharan, Soo Chin Lee, and David S.P. Tan, National University of Singapore; Yee Liang Thian, Joseph Ng, Jeffrey J.H. Low, Arunachalam Ilancheran, and Sharon Z.L. Koh, National University Hospital, Singapore, Republic of Singapore
| | - Jeffrey J.H. Low
- Natalie Y.L. Ngoi, Valerie Heong, Pei Yi Ong, Samuel G.W. Ow, Anand D. Jeyasekharan, Yi Wan Lim, Siew Eng Lim, Soo Chin Lee, and David S.P. Tan, National University Cancer Institute; Darwin Tay, Valerie Heong, Anand D. Jeyasekharan, Soo Chin Lee, and David S.P. Tan, National University of Singapore; Yee Liang Thian, Joseph Ng, Jeffrey J.H. Low, Arunachalam Ilancheran, and Sharon Z.L. Koh, National University Hospital, Singapore, Republic of Singapore
| | - Arunachalam Ilancheran
- Natalie Y.L. Ngoi, Valerie Heong, Pei Yi Ong, Samuel G.W. Ow, Anand D. Jeyasekharan, Yi Wan Lim, Siew Eng Lim, Soo Chin Lee, and David S.P. Tan, National University Cancer Institute; Darwin Tay, Valerie Heong, Anand D. Jeyasekharan, Soo Chin Lee, and David S.P. Tan, National University of Singapore; Yee Liang Thian, Joseph Ng, Jeffrey J.H. Low, Arunachalam Ilancheran, and Sharon Z.L. Koh, National University Hospital, Singapore, Republic of Singapore
| | - Sharon Z.L. Koh
- Natalie Y.L. Ngoi, Valerie Heong, Pei Yi Ong, Samuel G.W. Ow, Anand D. Jeyasekharan, Yi Wan Lim, Siew Eng Lim, Soo Chin Lee, and David S.P. Tan, National University Cancer Institute; Darwin Tay, Valerie Heong, Anand D. Jeyasekharan, Soo Chin Lee, and David S.P. Tan, National University of Singapore; Yee Liang Thian, Joseph Ng, Jeffrey J.H. Low, Arunachalam Ilancheran, and Sharon Z.L. Koh, National University Hospital, Singapore, Republic of Singapore
| | - David S.P. Tan
- Natalie Y.L. Ngoi, Valerie Heong, Pei Yi Ong, Samuel G.W. Ow, Anand D. Jeyasekharan, Yi Wan Lim, Siew Eng Lim, Soo Chin Lee, and David S.P. Tan, National University Cancer Institute; Darwin Tay, Valerie Heong, Anand D. Jeyasekharan, Soo Chin Lee, and David S.P. Tan, National University of Singapore; Yee Liang Thian, Joseph Ng, Jeffrey J.H. Low, Arunachalam Ilancheran, and Sharon Z.L. Koh, National University Hospital, Singapore, Republic of Singapore
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Wong AL, Soo RA, Tan DS, Lee SC, Lim JS, Marban PC, Kong LR, Lee YJ, Wang LZ, Thuya WL, Soong R, Yee MQ, Chin TM, Cordero MT, Asuncion BR, Pang B, Pervaiz S, Hirpara JL, Sinha A, Xu WW, Yuasa M, Tsunoda T, Motoyama M, Yamauchi T, Goh BC. Phase I and biomarker study of OPB-51602, a novel signal transducer and activator of transcription (STAT) 3 inhibitor, in patients with refractory solid malignancies. Ann Oncol 2015; 26:998-1005. [PMID: 25609248 DOI: 10.1093/annonc/mdv026] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 01/05/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The aim of this study was to determine the maximum-tolerated dose (MTD), safety, pharmacokinetics, and pharmacodynamics of OPB-51602, an oral, direct signal transduction activator of transcription 3 (STAT3) inhibitor, in patients with refractory solid tumors. PATIENTS AND METHODS Three cohorts were studied: cohort A, a sequential dose escalation of OPB-51602 administered intermittently (days 1-14 every 21 days); cohort B, an expansion cohort evaluating the dose lower than the MTD; cohort C, evaluating continuous daily dosing. RESULTS Fifty-one patients were studied at 2, 4, and 5 mg per day dosing. The MTD was 5 mg; first-cycle dose-limiting toxicities (DLTs) were grade 3 hyponatremia in one patient, and grade 3 dehydration in another. Intermittent dosing of both 2 and 4 mg doses were tolerable, and the recommended phase II dose was 4 mg. Cohort B investigated 4 mg intermittently, whereas cohort C investigated 4 mg continuously. Common toxicities included fatigue, nausea/vomiting, diarrhea, anorexia, and early-onset peripheral neuropathy. Drug-induced pneumonitis occurred in two patients in cohort C. Continuous dosing was associated with a higher incidence of peripheral neuropathy and a lower mean relative dose intensity, compared with intermittent dosing. Steady-state pharmacokinetics was characterized by high oral clearance, mean elimination half-life ranging from 44 to 61 h, and a large terminal-phase volume of distribution. An active metabolite, OPB-51822, accumulated to a greater extent than OPB-51602. Flow cytometry of peripheral blood mononuclear cells demonstrated pSTAT3 (Tyr(705)) inhibition following exposure. Two patients achieved partial responses at 5 mg intermittently and 4 mg continuously; both had epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC) with prior EGFR tyrosine kinase inhibitor exposure. CONCLUSION OPB-51602 demonstrates promising antitumor activity, particularly in NSCLC. Its long half-life and poorer tolerability of continuous dosing, compared with intermittent dosing, suggest that less frequent dosing should be explored. CLINICALTRIALSGOV IDENTIFIER NCT01184807.
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Affiliation(s)
- A L Wong
- Department of Haematology-Oncology, National University Health System; Haematology Oncology Research Group, National University Cancer Institute of Singapore, National University Health System; Cancer Science Institute
| | - R A Soo
- Department of Haematology-Oncology, National University Health System; Haematology Oncology Research Group, National University Cancer Institute of Singapore, National University Health System; Cancer Science Institute
| | - D S Tan
- Department of Medical Oncology, National Cancer Centre
| | - S C Lee
- Department of Haematology-Oncology, National University Health System; Haematology Oncology Research Group, National University Cancer Institute of Singapore, National University Health System; Cancer Science Institute
| | - J S Lim
- Department of Haematology-Oncology, National University Health System; Haematology Oncology Research Group, National University Cancer Institute of Singapore, National University Health System
| | - P C Marban
- Haematology Oncology Research Group, National University Cancer Institute of Singapore, National University Health System
| | | | | | - L Z Wang
- Cancer Science Institute; Departments of Pharmacology
| | | | | | | | - T M Chin
- Department of Haematology-Oncology, National University Health System; Haematology Oncology Research Group, National University Cancer Institute of Singapore, National University Health System; Cancer Science Institute
| | - M T Cordero
- Haematology Oncology Research Group, National University Cancer Institute of Singapore, National University Health System
| | | | | | - S Pervaiz
- Physiology, Yong Loo Lin School of Medicine
| | | | - A Sinha
- Department of Diagnostic Imaging, National University Health System, Singapore
| | - W W Xu
- Otsuka Beijing Research Institute, Beijing, China
| | - M Yuasa
- Otsuka Pharmaceutical Co., Ltd, Chiyoda-ku
| | - T Tsunoda
- Otsuka Pharmaceutical Co., Ltd, Chiyoda-ku
| | - M Motoyama
- Otsuka Pharmaceutical Co., Ltd, Chiyoda-ku
| | - T Yamauchi
- Fuji Memorial Research Institute, Otsuka Pharmaceutical Co. Ltd, Chiyoda-ku, Japan
| | - B C Goh
- Department of Haematology-Oncology, National University Health System; Haematology Oncology Research Group, National University Cancer Institute of Singapore, National University Health System; Cancer Science Institute; Departments of Pharmacology.
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Tan DS, Lambros MB, Rayter S, Natrajan R, Vatcheva R, Gao Q, Marchiò C, Geyer FC, Savage K, Parry S, Fenwick K, Tamber N, Mackay A, Dexter T, Jameson C, McCluggage WG, Williams A, Graham A, Faratian D, El-Bahrawy M, Paige AJ, Gabra H, Gore ME, Zvelebil M, Lord CJ, Kaye SB, Ashworth A, Reis-Filho JS. PPM1D Is a Potential Therapeutic Target in Ovarian Clear Cell Carcinomas. Clin Cancer Res 2009; 15:2269-80. [DOI: 10.1158/1078-0432.ccr-08-2403] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Tan DS, Reis-Filho JS. Comparative Genomic Hybridisation Arrays: High-Throughput Tools to Determine Targeted Therapy in Breast Cancer. Pathobiology 2008; 75:63-74. [DOI: 10.1159/000123844] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Tan DS, Burbaum JJ. Ligand discovery using encoded combinatorial libraries. Curr Opin Drug Discov Devel 2000; 3:439-453. [PMID: 19649875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Solid-phase combinatorial synthesis using split-pool or direct divide methods allows large libraries of complex molecules to be generated. Encoding techniques used during synthesis allow the identities of the products to be determined readily. An overview of this process and its application to ligand discovery are presented, along with comparisons to alternative approaches. Libraries are classified depending upon their intended use as discovery libraries (for broad screening), targeted libraries (for structure-based screening) and optimization libraries (for activity improvement). Biological assays can be performed on the solid support that is used in synthesis, or in solution under in vitro or in vivo conditions, with readouts indicative of either receptor binding or biological activity. This approach has led to numerous examples of successful ligand discovery.
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Affiliation(s)
- D S Tan
- Department of Chemistry and Chemical Biology, Institute of Chemistry and Cell Biology, Harvard University, Cambridge, MA 02138, USA.
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Leong AC, Hanby AM, Potts HW, Tan DS, Skilton D, Ryder K, Harris WH, Liebmann RD, Barnes DM, Gillett CE. Cell cycle proteins do not predict outcome in grade I infiltrating ductal carcinoma of the breast. Int J Cancer 2000. [PMID: 10719727 DOI: 10.1002/(sici)1097-0215(20000120)89:1<26::aid-ijc5>3.0.co;2-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Infiltrating ductal mammary carcinomas are histologically graded according to their extent of differentiation. Well-differentiated, grade I, tumours have low proliferative activity, usually form tubules and exhibit little nuclear pleomorphism. Despite an apparently reassuring morphology, 10-15% of grade I ductal carcinomas metastasize, albeit after a prolonged period. Recent evidence supports the view that evolution to higher grade malignancies occurs rarely and that grade I tumours are biologically distinct from grade III tumours. We have examined a series of 148 grade I ductal carcinomas in order to ascertain whether information about the level of expression of cyclin D1, p27, p53, oestrogen receptor status (ER) or proliferative activity could be used to identify those patients with a poor outcome. The majority of tumours expressed high levels of cyclin D1, p27 and ER, low levels of p53 and had low Ki-67 expression and mitotic counts. Cyclin D1, p27 and ER expression were all significantly correlated with each other but not with p53 (cyclin D1 correlation with ER, p = 0.01; cyclin D1 correlation with p27 and ER correlation with p27 both p < 0.0001). Cyclin D1 and ER were also both correlated with Ki-67 (p = 0.01 and p < 0.0001) but not with mitotic count. Our results suggest that cyclin D1, ER and p27 are all markers of well-differentiated tumours and that their detection is related to proliferative activity in a manner reflecting their functional role within the normal cell cycle. However, none of the proteins or markers of proliferative activity were sensitive enough to predict which patients were likely to have a poor outcome.
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Affiliation(s)
- A C Leong
- Hedley Atkins/ICRF Breast Pathology, Laboratory, Guy's Hospital, London, United Kingdom
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Leong AC, Hanby AM, Potts HW, Tan DS, Skilton D, Ryder K, Harris WH, Liebmann RD, Barnes DM, Gillett CE. Cell cycle proteins do not predict outcome in grade I infiltrating ductal carcinoma of the breast. Int J Cancer 2000; 89:26-31. [PMID: 10719727 DOI: 10.1002/(sici)1097-0215(20000120)89:1<26::aid-ijc5>3.0.co;2-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [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: 02/03/2023]
Abstract
Infiltrating ductal mammary carcinomas are histologically graded according to their extent of differentiation. Well-differentiated, grade I, tumours have low proliferative activity, usually form tubules and exhibit little nuclear pleomorphism. Despite an apparently reassuring morphology, 10-15% of grade I ductal carcinomas metastasize, albeit after a prolonged period. Recent evidence supports the view that evolution to higher grade malignancies occurs rarely and that grade I tumours are biologically distinct from grade III tumours. We have examined a series of 148 grade I ductal carcinomas in order to ascertain whether information about the level of expression of cyclin D1, p27, p53, oestrogen receptor status (ER) or proliferative activity could be used to identify those patients with a poor outcome. The majority of tumours expressed high levels of cyclin D1, p27 and ER, low levels of p53 and had low Ki-67 expression and mitotic counts. Cyclin D1, p27 and ER expression were all significantly correlated with each other but not with p53 (cyclin D1 correlation with ER, p = 0.01; cyclin D1 correlation with p27 and ER correlation with p27 both p < 0.0001). Cyclin D1 and ER were also both correlated with Ki-67 (p = 0.01 and p < 0.0001) but not with mitotic count. Our results suggest that cyclin D1, ER and p27 are all markers of well-differentiated tumours and that their detection is related to proliferative activity in a manner reflecting their functional role within the normal cell cycle. However, none of the proteins or markers of proliferative activity were sensitive enough to predict which patients were likely to have a poor outcome.
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Affiliation(s)
- A C Leong
- Hedley Atkins/ICRF Breast Pathology, Laboratory, Guy's Hospital, London, United Kingdom
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Tan DS, Potts HW, Leong AC, Gillett CE, Skilton D, Harris WH, Liebmann RD, Hanby AM. The biological and prognostic significance of cell polarity and E-cadherin in grade I infiltrating ductal carcinoma of the breast. J Pathol 1999; 189:20-7. [PMID: 10451483 DOI: 10.1002/(sici)1096-9896(199909)189:1<20::aid-path394>3.0.co;2-2] [Citation(s) in RCA: 37] [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: 11/12/2022]
Abstract
Grading of breast cancer based on the modified Scarff, Bloom, and Richardson system provides invaluable prognostic information. Recent evidence suggests that most tumours do not usually progress between grades and that groups of tumours within each grade are biologically distinct. This study has explored one potential aspect of biological tumour heterogeneity within grade by examining the relationship between cell polarity, the cell adhesion molecule E-cadherin, a major effector of cell polarity, and outcome, in 149 grade I infiltrating ductal breast carcinomas. Polarity was evaluated by studying the degree to which three features of polarized epithelial cells-nuclear ordering, basal positioning of nuclei within cells, and apical snouting/blebbing-were present in these tumours. E-cadherin expression was investigated using the antibody HECD-1. A low degree of tubule formation was correlated with poor nuclear ordering ( p< 0.01). The three histological features-nuclear ordering, basal nuclei, and apical blebbing-were all correlated with each other (all p< 0.0001). Polarity measurements did not correlate with survival. E-cadherin expression did not correlate with polarity and negative tumours were still able to form tubules. Surprisingly, strong E-cadherin immunostaining correlated with poor survival, tumour size, and nodal status. On univariate parametric (Weibull) survival models, high E-cadherin scores and tumour size were both significant predictors of survival in this group.
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Affiliation(s)
- D S Tan
- Hedley Atkins/ICRF Breast Pathology Laboratory, Guy's Hospital, St Thomas' Street, London SE1 9RT, U.K
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Tan DS, Ang SG, Sim TS. Involvement of a third histidine in the ferrous active site of isopenicillin N synthase of Cephalosporium acremonium repudiated by recombinant double histidine mutants. Biochem Mol Biol Int 1998; 44:333-45. [PMID: 9530516 DOI: 10.1080/15216549800201352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Site-directed mutagenesis studies have shown that the isopenicillin N synthase of Cephalosporium acremonium (cIPNS) requires two essential histidine residues (H216, H272) for activity. The determination of iron bound to the wildtype cIPNS and its absence in the mutants lacking histidine at positions 216 and 272 clearly supports the essential role these two histidines play in iron binding. However, nuclear magnetic resonance (NMR) studies have indicated that there could be three histidine residues that possibly coordinate the essential iron at the active site. To search for a presumed third histidine ligand, mutant cIPNS genes containing mutations at two histidine codons were created by in vitro cloning of fragments from the expression vectors bearing the respective cIPNS genes each with a single histidine mutation at positions H49, H64, H116, H126 and H137. All ten possible double histidine mutant cIPNS constructs were subsequently expressed in Escherichia coli. If a third histidine had a participatory role in the iron active centre of cIPNS, then one of the constructed double histidine mutants would have lost its enzymatic activity. However, analysis of the cIPNS activities of these recombinant double histidine mutants indicated that none of them was totally inactivated. Thus, the involvement of a third histidine can be repudiated.
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Affiliation(s)
- D S Tan
- Ngee Ann Polytechnic, Department of Biotechnology, Singapore
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Tan DS, Sim TS. Functional analysis of conserved histidine residues in Cephalosporium acremonium isopenicillin N synthase by site-directed mutagenesis. J Biol Chem 1996; 271:889-94. [PMID: 8557701 DOI: 10.1074/jbc.271.2.889] [Citation(s) in RCA: 29] [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: 01/31/2023] Open
Abstract
The isopenicillin N synthase of Cephalosporium acremonium (cIPNS) involves a catalytically important non-heme iron which is coordinated credibly to histidine residues. A comparison of the IPNS genes from various microbial sources indicated that there are seven conserved histidine residues. These were individually replaced by leucine residues through site-directed mutagenesis, and the sites of mutation were confirmed by DNA sequencing. The seven mutant genes were cloned separately into the vector pET24d for expression in Escherichia coli BL21 (DE3), and the proteins were expressed as soluble enzymes. All the resulting mutant enzymes obtained have mobilities of approximately 38 kDa, identical with the wild-type enzyme on SDS-polyacrylamide gel electrophoresis, and were also reactive to cIPNS antibodies. The enzymes were purified by ammonium sulfate precipitation and DEAE-Sephadex A-50 ion exchange chromatography, and these were analyzed for enzyme activity. A group of mutant enzymes, H49L, H64L, H116L, H126L, and H137L, were found to be enzymatically active with reduced activities of 16-93.7%, indicating that they are not essential for catalysis. Two of the mutant enzymes, H216L and H272L, were found to have lost their enzymatic activity completely, indicating that both His-216 and His-272 are crucial for catalysis. It is suggested that these histidines are likely to serve as ligands for binding to the non-heme iron in the IPNS active site. Alignment of the amino acid sequence of IPNS to related non-heme Fe(2+)-requiring enzymes indicated that the two essential histidine residues correspond to two invariant residues located in highly homologous regions. The conservation of the two closely located histidine residues indicates the possible conservation of similar iron-binding sites in these enzymes.
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Affiliation(s)
- D S Tan
- Department of Microbiology, Faculty of Medicine, National University of Singapore, Republic of Singapore
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Tiow-Suan S, Tan DS. Biophysical factors affecting the expression of isopenicillin N synthase isozymes in Escherichia coli. Biochem Mol Biol Int 1995; 35:1069-1078. [PMID: 7549925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The influence of biophysical factors over the production of isozymes of isopenicillin N synthase (IPNS) from fungal and bacterial sources in Escherichia coli was examined. The effect of these parameters on the expression of Cephalosporium acremonium IPNS was determined by using two expression vectors containing the lac- or the T7-promoter. Under the lac-promoter, IPNS expressed in E. coli reached 5-15% of total soluble proteins and under the T7 promoter, the level reached approximately 50% of total soluble proteins. Furthermore the high level of expression did not affect aggregation of IPNS proteins. Analysis of the hydrophobicity of the C. acremonium IPNS and site-specific mutant enzymes relative to other IPNS isozymes suggested that proteins of low gravy scores (< or = -0.515) tend to be soluble whereas higher gravy scores (> or = -0.512) form aggregates. Neither the GC content of the gene nor the relative percentage proline content of the protein affected the expression of the IPNS isozymes in E. coli.
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Affiliation(s)
- S Tiow-Suan
- Department of Microbiology, Faculty of Medicine, National University of Singapore
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Tiow-Suan S, Tan DS. Histidine-272 of isopenicillin N synthase of Cephalosporium acremonium, which is possibly involved in iron binding, is essential for its catalytic activity. FEMS Microbiol Lett 1994; 120:241-7. [PMID: 8076799 DOI: 10.1111/j.1574-6968.1994.tb07040.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Amino acid sequence alignment of the Cephalosporium acremonium isopenicillin N synthase (cIPNS) to similar non-heme Fe(2+)-containing enzymes from 28 different sources (bacterial, fungal, plant and animals) revealed a homologous region of high sequence conservation containing an invariant histidine residue at position 272 in cIPNS. The importance of this histidine residue in cIPNS was investigated through site-directed mutagenesis by replacing the histidine residue with leucine. The mutated gene was verified by DNA sequence analysis and expressed in Escherichia coli. When analyzed by denaturing gel electrophoresis and immunoblotting, the mutant cIPNS had identical mobility as that of the wild-type enzyme. Enzyme studies on the mutant enzyme showed loss of enzymatic activity indicating that His272 is essential for the catalytic function of cIPNS, possibly as a ligand for iron binding.
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Affiliation(s)
- S Tiow-Suan
- Department of Microbiology, Faculty of Medicine, National University of Singapore
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Balasubramaniam V, Sinniah M, Tan DS, Redzwan G, Lo'man SG. The role of cytomegalovirus (CMV) infection in congenital diseases in Malaysia. Med J Malaysia 1994; 49:113-116. [PMID: 8090088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A previous cross-sectional serological survey of various age groups (0-55 years) of the Malaysian normal population showed that cytomegalovirus (CMV) infection is highly endemic in Malaysia. A total of 1,688 infants (0-4 months) with congenital abnormalities were screened for evidence of congenital CMV infection and the rest of the TORCHES (TOxoplasmosis, Rubella, Cytomegalovirus, HErpes simplex, Syphilis) group of congenital infections. Congenital CMV infection was detected in 193 (11.4%) infants which is significantly higher than the prevalence of congenital syphilis (4%), congenital rubella infection (3.7%), congenital toxoplasma (1.0%) and congenital herpes simplex virus infection (0%). Of the 193 cases, 10.4 per cent had CNS defects. We concluded that 1) congenital CMV appears to be the most important cause of congenital infections among the TORCHES diseases in Malaysia; and 2) secondary rather than primary infections or reactivation is responsible for most of the intrauterine CMV infection in Malaysia, as primary infection is usually associated with neurological involvement.
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Tan DS, Dimitrakakis M, Mangalam S, Lopez CG, Ooi BG. Prevalence of hepatitis delta virus infection in Malaysia. Singapore Med J 1989; 30:34-7. [PMID: 2595386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The prevalence of coinfection, superinfection and chronic infection with the hepatitis delta virus (HDV) was studied in 324 hepatitis B surface antigen (HBsAg)-positive Malaysians. Of these, 10.0% (5/50) had coinfection, 5.7% (11/194) had superinfection, but none of the 80 patients with chronic liver disease (CLD) or primary hepatocellular carcinoma (PHC) had chronic infection with HDV. The overall HDV infection was 4.9% (16/324). One of the coinfection cases acquired the HDV infection as early as 1982. HDV superinfection was detected mainly among IV drug abusers (20% or 7/35) and promiscuous males and females (13.6% or 3/22). They were all asymptomatic. Only 0.8% (1/125) apparently healthy blood donors was infected with HDV. None of the 12 multi-transfused patients examined were positive. Malaysia is the only Southeast Asian country examined so far in which HDV infection was detected. The reason could be that the IV drug abusers and the sexually promiscuous groups missed being examined in the other countries. Comparing the HDV infection rates in 4 categories of infected Malaysians (viz. acute hepatitis B patients, IV drug abusers, blood donors and CLD patients) with those of other countries, it was noted that the Malaysian rates were similar to the lowest in the range of prevalence rates of each category in the latter group. The rate of coinfection in a preliminary study in 1982-84 (9.0% or 1/11) was not very different from that obtained to date (10.0% or 5/50).(ABSTRACT TRUNCATED AT 250 WORDS)
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Mangalam S, Tan DS, Vijayamalar B, Collett D, Fang R. Markers of hepatitis B virus infection in asymptomatic drug abusers in Malaysia. Southeast Asian J Trop Med Public Health 1986; 17:209-13. [PMID: 3787308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Sera from 200 Malaysian male drug abusers were tested for markers of Hepatitis B virus (HBV) infection, viz. HBsAg, HBeAg, anti-HBs and anti-HBc using commercially available enzyme immunoassay (EIA) kits supplied by Abbot Laboratories, Chicago. Of these, 103 (51.5%) were positive for at least one HBV marker, 11 (5.5%) were positive for HBsAg; 4 (2%) for HBeAg, 74 (37%) for anti-HBs and 85 (42.5%) for anti-HBc. The HBsAg carrier rate was roughly the same as the carrier rate in the general population of Malaysia. The majority of drug abusers (95%) have had subclinical, asymptomatic HBV infection. Racially the Malay drug abusers had the highest exposure rate (54.2%). The HBsAg carrier rate was highest in the Chinese drug abusers (15.3%) and lowest in the Indians (0%). The mean age for the HBsAg carriers was found to be 26 years with a mean duration of drug abuse of 72 months. The Malaysian Anti-Narcotics Task Force of the National Security Council reported in the Malay Mail (July 13, 1985) that there were about 106,000 identified drug abusers in Malaysia and that 63% of these were in the 20-29 age groups. It appears from our study that this age group also coincides with the period of high HBsAg carrier rate. Age wise, those less than 21 years old had the highest HBsAg (11%) and HBeAg (5.6%) prevalence rates indicating high infectivity. After the age of 30 years, nearly 50% of the drug abusers appear to be immune with the HBe prevalence of 0%.(ABSTRACT TRUNCATED AT 250 WORDS)
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Tan DS, Zaini Rahman M, Fang R, Collett D, Ooi BG. Hepatitis B markers in non-icteric medical patients in Malaysia. Southeast Asian J Trop Med Public Health 1986; 17:214-8. [PMID: 3538435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Sera were obtained from 494 non-icteric patients admitted with illnesses other than overt hepatitis into the medical wards of the rural and urban hospitals in Malaysia. They were tested for HBsAg, HBeAg, and anti-HBs by enzyme immunoassay. The overall HBsAg carrier rate was 18.0% ranging from 9.6% in children, (10 years and under), to a maximum of 23.5% in the adolescents (11 to 20 years), the rates decreasing subsequently to 16.5% and 20.8% in the adult and middle-age groups, respectively. The Chinese (18.6%) and Malays (19.9%) had similar HBsAg carrier rates but the rate in the Indians (9.0%) was distinctly lower. Similar rates were observed in the males (16.5%) and the females (19.8%). The carrier rate was 17.1% in rural patients compared with 21.4% in the urban ones. The 'e' antigen was found in 14 of the 89 HBsAg carriers (15.7%). The overall prevalence was 14/494 (2.8%) rising sharply from childhood (2.9%) to adolescence (5.3%), subsequently declining with advancing age. The Chinese had the highest rate (6.2%) followed by the Indians (1.5%) and the Malays (1.1%). Males had a rate of 3.3% compared to the females with 2.3%. Anti-HBs was found in 33.8% of the patients, increasing steadily from childhood (18.3%) to middle-age (46.4%). The Chinese had a higher prevalence rate (41.6%) than the Indians (32.8%) and the Malays (29.3%). The rates were similar for the males (35.6%) and the females (31.5%). Rural patients (46.1%) had a higher rate than urban patients (35.7%). Both areas showed rising prevalence with increasing age.(ABSTRACT TRUNCATED AT 250 WORDS)
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Sinniah M, Dimitrakakis M, Tan DS. Delta hepatitis in Malaysia. Southeast Asian J Trop Med Public Health 1986; 17:229-33. [PMID: 3787309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Sera from one hundred and fifty nine Malaysian individuals were screened for the prevalence of delta markers. These included 15 HBsAg positive homosexuals, 16 acute hepatitis B cases, 9 chronic hepatitis B patients, 13 healthy HBsAg carriers and 106 intravenous (i.v.) drug abusers, of whom 27 were positive for HBsAg only and the rest were anti-HBc IgG positive but HBsAg negative. The prevalence of delta markers in the homosexuals was found to be 6.7%, in the HBsAg positive drug abusers 17.8%, in acute hepatitis B cases 12.5%. No evidence of delta infection was detected in healthy HBsAg carriers, chronic hepatitis B cases and HBsAg negative i.v. drug abusers. With reference to i.v. drug abusers, the prevalence of delta markers was higher in Malays (23%) than in Chinese (7%) although the latter had a higher HBsAg carrier rate. Although the HBsAg carrier rate in the homosexuals was high, their delta prevalence rate was low as compared to drug abusers. In Malaysia, as in other non-endemic regions, hepatitis delta virus transmission appeared to occur mainly via the parenteral and sexual routes. This is the first time in Malaysia that a reservoir of delta infection has been demonstrated in certain groups of the population at high risk for hepatitis B.
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Tan DS, Dimitrakakis M, Zaini Rahman M, Fang R, Collett D, Ooi BG, Gust ID. Aetiology of acute hepatitis in Malaysia. Southeast Asian J Trop Med Public Health 1986; 17:205-8. [PMID: 3024325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Icteric patients with clinical and biochemical evidence of liver disease, admitted into various hospitals in Malaysia, were investigated to determine the cause of their infection. Of these patients, 11.0% (16/145) were found positive for IgM anti-HAV (EIA), 4.1% (6/145) for IgM anti-HBc (EIA), 1.0% (1/102) for IgM anti-CMV (ELISA), 17.2% (16/64) for rising titres of leptospiral agglutinin, and none for heterophile antibody of EBV. Hepatitis NANB accounted for 67.9% of cases. The mean serum transaminases (ALT and AST) values in patients with hepatitis A and B were higher (more than 500IU) than in patients with leptospirosis or non-A, non-B hepatitis, whereas serum bilirubin levels were higher in patients with hepatitis A and leptospirosis than in patients with hepatitis B.
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Tan DS, Fang R, Collett D, Ooi BG. A seroepidemiologic study of hepatitis A in Malaysia. Southeast Asian J Trop Med Public Health 1986; 17:201-4. [PMID: 3538434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Sera from 494 non-icteric patients admitted with illnesses other than overt hepatitis into the various hospitals in rural and urban Malaysia were tested for IgG antibody to hepatitis A virus. The overall antibody prevalence rate was 67.0% with rates increasing steadily from childhood 10 years old and under (39.4%) to middle-age and above (96.0%). No significant differences were noted between males (68.4%) and females (65.3%). The highest rate was in the Indians (80.6%), the lowest in the Chinese (55.9%) with Malays occupying intermediate position (70.3%). The rate in the rural patients (74.7%) was higher than that in the urban patients (65.5%) especially in the 21 to 40 year age-group where the rural patients had a rate of 96.7% compared with that in urban patients (61.1%). A comparison of antibody prevalence rates in different countries was made.
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Tan DS, Jeyaindran S. 16 cases of acute renal failure due to leptospirosis. Med J Malaysia 1986; 41:152-5. [PMID: 3821611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Tan DS. Congenital rubella syndrome in Malaysia. Med J Malaysia 1985; 40:11-4. [PMID: 3831727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Tan DS, Mak JW. The role of toxoplasmosis in congenital disease in Malaysia. Southeast Asian J Trop Med Public Health 1985; 16:88-92. [PMID: 4023821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Toxoplasmosis was found not to be an important cause of intrauterine infection in Malaysia as the rate of toxoplasma-specific IgM in 1,060 congenitally defective Malaysian children, 0 to 4 months old (0.4%) was lower than that in 405 normal children of the same age group (2.0%). A total of 8.2 intra-uterine toxoplasmic infections per 1,000 live births was detected of which one-third (2.7 per 1,000 live births) was overt, manifesting symptoms more of liver damage, than eye or brain damage. A comparison was made with the rates in U.S.A. and Europe. The role of toxoplasmosis in abortion needs to be studied.
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Tan DS. Serum IgM-globulin in Malaysian normal and defective infants. Med J Malaysia 1983; 38:15-8. [PMID: 6633327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Tan DS. Some zoonotic diseases prevalent in Malaysia. Malays J Pathol 1981; 4:19-27. [PMID: 7186600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Tan DS, Lee WS. An enterovirus type 70 epidemic of acute conjunctivitis in peninsular Malaysia, 1980. Med J Malaysia 1981; 36:76-8. [PMID: 7343822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Tan DS, Stern H. A serological study of cytomegalovirus and herpes simplex virus infections in Peninsular Malaysia. Bull World Health Organ 1981; 59:909-12. [PMID: 6279323 PMCID: PMC2396140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Healthy Malaysians from various parts of Peninsular Malaysia were examined for CF antibodies against cytomegalovirus (CMV) and herpes simplex virus (HSV) type 2. CMV antibodies were detected in 1114 out of 1556 persons (71.6%) and HSV antibodies were detected in 954 persons out of 1554 (61.4%). The age distribution patterns were similar for the two infections, with maximum prevalence at 5 - 14 years of age. Prevalence was higher in women than in men. There were no significant differences among the Malay, Chinese, and Indian groups of the population with respect to CMV, 72 - 78% possessing antibodies, but in the case of HSV, 76% of the Chinese had antibodies, compared with 57 - 60% of the Malays and Indians. More than 90% of newborn infants had CMV and HSV CF antibodies, confirming the highly immune status of childbearing women in Malaysia. No CMV-specific IgM was detected in the Malaysian neonates examined but this does not exclude the possibility of congenital infection.
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Tan DS, Chew V, Nuruddin NM. Rubella cases mistaken for dengue fever. Singapore Med J 1980; 21:769-70. [PMID: 7221591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Supramaniam V, Tan DS. An outbreak of rubella among Malaysian Air Force recruits, 1979. Med J Malaysia 1980; 34:415-7. [PMID: 7219274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Tan DS, Yin-Murphy M, Kandiah S. An outbreak of acute conjunctivitis caused by coxsackievirus A24 in Kuala-Lumpur, Malaysia, 1978. Southeast Asian J Trop Med Public Health 1980; 11:24-7. [PMID: 6250226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
An investigation of an outbreak of acute conjunctivitis in Kuala Lumpur from May to August 1978 was made. A total of 2,133 cases was involved, most of whom were adult Malay males of low income status from the surrounding villages and low-cost flats. The majority of cases had bilateral conjunctivitis with clear discharge. Pain and subconjunctival haemorrhage were not common and recovery, mostly without complications, occurred within 1 week. Eye scrapings and paired sera specimens were examined and the causal agent was found to be Coxsackievirus A24 (CA24).
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Tan DS, Omar M, Yap TC. Influenza HI antibodies in pig and man in Malaysia (with special reference to swine influenza). Med J Malaysia 1979; 34:159-62. [PMID: 548720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Tan DS. Leptospirosis in West Malaysia--epidemiology and laboratory diagnosis. Malays J Pathol 1979; 2:1-6. [PMID: 263416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Tan DS, Omar M, Chew V. Influenza HI antibodies in dengue-positive and negative sera of febrile patients. Med J Malaysia 1979; 33:355-6. [PMID: 522749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Tan DS, Lam SK. Enterovirus survey before and after poliomyelitis vaccination in Kuala Lumpur, Malaysia. Southeast Asian J Trop Med Public Health 1978; 9:301-7. [PMID: 219550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Stool samples from healthy children mainly of the low income group aged 0 to 7 years of age from five Maternal and Child Health Centres in Kuala Lumpur were obtained for isolation of enteroviruses. The specimens were collected before and after the mass vaccination given in the face of polio type 1 epidemic which started in October, 1971. The prevelance rate of enteroviruses was 11.9% (3.0% polioviruses, 8.9% non-polio enteroviruses) before the vaccination and essentially the same after. Coxsackie A viruses predominated over the other enteroviruses in the pre- and post-vaccination phases. The highest isolation rate of enteroviruses was observed in children 0 to 2 years age. No significant differences in distribution by sex, race and month were noted. A sharp fall in the prevalence rates of total enteroviruses and polioviruses was noted shortly after the mass vaccination campaign However, the rates reverted to the pre-vaccination state during the next successive years.
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Tan DS, Zaman V, Lopes M. Infectious mononucleosis or toxoplasmosis? Med J Malaysia 1978; 33:23-5. [PMID: 750891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Tan DS, Babudieri B. Ornithosis in peninsular Malaysia (in man and pigeons). Med J Malaysia 1977; 31:188-91. [PMID: 904510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Tan DS, Omar M. Survey of influenza Hi antibodies in Peninsula Malaysian sera collected before and after the Hongkong 'flu epidemic in 1968. Med J Malaysia 1974; 29:17-23. [PMID: 4282624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Tan DS, Welch QB. Evaluation of Leptospira biflexa antigens for screening human sera by the microscopic agglutination (MA) test in comparison with the sensitized-erythrocyte-lysis (SEL) test. Southeast Asian J Trop Med Public Health 1974; 5:12-6. [PMID: 4839075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Tan DS. Occupational distribution of leptospiral (SEL) antibodies in West Malaysia. Med J Malaysia 1973; 27:253-7. [PMID: 4270781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Tan DS, Zaman V. Toxoplasma antibody survey in West Malaysia. Med J Malaysia 1973; 27:188-91. [PMID: 4268921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Tan DS. The uses of gamma globulin in the prevention of virus diseases. Med J Malaya 1972; 27:129-33. [PMID: 4123039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Tan DS, Ariff AW. An outbreak of rabies in West malaysia in 1970 with unusual laboratory observations. Med J Malaya 1972; 27:107-14. [PMID: 4268035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Tan DS, Henle G. Antibodies to EBV related antigens in West Malaysian children. Med J Malaya 1972; 27:27-9. [PMID: 4345645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Tan DS, Lopes DA. A preliminary study of the status of leptospirosis in the Malaysian Armed forces. Southeast Asian J Trop Med Public Health 1972; 3:208-11. [PMID: 5082848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Tan DS, Dhillon GS, Omar M, Eapen JS. An outbreak of Hongkong influenza in a youth camp in West Malaysia. Med J Malaya 1971; 25:263-8. [PMID: 4261297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Tan DS. Leptospirosis in rural West Malaysia. Med J Malaya 1970; 24:261-6. [PMID: 4248346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Tan DS, Peck AJ, Omar M. The importance of Malaysian bats in the transmission of oral disease. Med J Malaya 1969; 24:32-5. [PMID: 4243840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Tan DS. Sensitized-erythrocyte-lysis (SEL) test as an epidemiological tool for human leptospirosis serological surveys. Bull World Health Organ 1969; 40:899-902. [PMID: 5307602 PMCID: PMC2554754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Epidemiological studies of human leptospirosis have generally been limited to countries with specialized laboratories employing the microscopic-agglutination (MA) test. The sensitized-erythrocyte-lysis (SEL) test is much simpler for routine hospital laboratories to carry out and it has been found valuable in the diagnosis of human leptospirosis. This paper reports the results of studies of the SEL test as an epidemiological tool in serological surveys.The results showed that the significant SEL titre was 1:80 and that the sensitivity of the test depended possibly on the antigen preparation and the amount of complement used. Most of the SEL antibodies were found to persist at significant titres for about 1 year after active infection, but less than half persisted longer than that. The SEL test is therefore useful for detecting recent infections and for indicating that stability of leptospirosis in an area.The endemicity of leptospirosis in West Malaysia was confirmed by the SEL test, based on the employment of 1:80 as the significant titre.
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