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Kim M, Narinesingh D, Hamm J, Marwaha A, Zhao R, Malyala R, Proulx R, Jaswal J, Karvat A, Leong C, Krauze A. Radiation Therapy in Elderly Patients With Squamous Cell Carcinoma of the Head and Neck — Insights From Real World Registry DATA (2007-2017). Int J Radiat Oncol Biol Phys 2021. [DOI: 10.1016/j.ijrobp.2021.07.1098] [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: 11/30/2022]
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2
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Leong C, Teoh T, Bentley L, O'Rourke E, Lim W, Htun N, Premaratne M. Downstream Impact Of Expansion Of Computed Tomography Coronary Angiography: An Australian Single Tertiary Center Experience. J Cardiovasc Comput Tomogr 2020. [DOI: 10.1016/j.jcct.2020.06.027] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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3
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Leong C, Schmid B, Buttafuoco A, Glatz M, Bosshard PP. In vitroefficacy of antifungal agents alone and in shampoo formulation against dandruff‐associatedMalasseziaspp. andStaphylococcusspp. Int J Cosmet Sci 2019; 41:221-227. [DOI: 10.1111/ics.12525] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 03/05/2019] [Indexed: 11/29/2022]
Affiliation(s)
- C. Leong
- Department of Dermatology University Hospital Zurich Zurich Switzerland
- Faculty of Medicine University of Zurich Zurich Switzerland
| | - B. Schmid
- Department of Dermatology University Hospital Zurich Zurich Switzerland
- Faculty of Medicine University of Zurich Zurich Switzerland
| | - A. Buttafuoco
- Department of Dermatology University Hospital Zurich Zurich Switzerland
- Faculty of Medicine University of Zurich Zurich Switzerland
| | - M. Glatz
- Department of Dermatology University Hospital Zurich Zurich Switzerland
- Faculty of Medicine University of Zurich Zurich Switzerland
| | - P. P. Bosshard
- Department of Dermatology University Hospital Zurich Zurich Switzerland
- Faculty of Medicine University of Zurich Zurich Switzerland
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4
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Forde CG, Leong C, Chia-Ming E, McCrickerd K. Fast or slow-foods? Describing natural variations in oral processing characteristics across a wide range of Asian foods. Food Funct 2017; 8:595-606. [DOI: 10.1039/c6fo01286h] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [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
The structural properties of foods have a functional role to play in oral processing behaviours and sensory perception, and also impact on the meal size and the experience of fullness.
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Affiliation(s)
- C. G. Forde
- Clinical Nutrition Research Centre (CNRC)
- Centre for Translational Medicine
- Yong Loo Lin School of Medicine
- Singapore 117599
- Singapore
| | - C. Leong
- Clinical Nutrition Research Centre (CNRC)
- Centre for Translational Medicine
- Yong Loo Lin School of Medicine
- Singapore 117599
- Singapore
| | - E. Chia-Ming
- Clinical Nutrition Research Centre (CNRC)
- Centre for Translational Medicine
- Yong Loo Lin School of Medicine
- Singapore 117599
- Singapore
| | - K. McCrickerd
- Clinical Nutrition Research Centre (CNRC)
- Centre for Translational Medicine
- Yong Loo Lin School of Medicine
- Singapore 117599
- Singapore
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Leong C, Buttafuoco A, Schmid-Grendelmeier P, Bosshard P, Glatz M. 341 Accelerated growth of Malassezia species in optimized culture conditions. J Invest Dermatol 2016. [DOI: 10.1016/j.jid.2016.06.361] [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: 10/21/2022]
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6
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Tan Y, Cheong S, Leong C. Systemic Delivery of siRNA-Based Therapeutics Using Functionalised Single-Walled Carbon Nanotubes. Cytotherapy 2016. [DOI: 10.1016/j.jcyt.2016.03.073] [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: 10/21/2022]
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7
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Niknejad T, Bugalho R, Carlos Rasteiro Da Silva J, Di Francesco A, Ferramacho L, Leong C, Rolo M, Silva R, Silveira M, Tavernier S, Varela J. PET-ToF system with highly integrated SiPM readout. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)30222-5] [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: 11/15/2022]
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8
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Leong C, Semião J, Santos MB, Teixeira IC, Teixeira JP. Fault-Tolerance in Field Programmable Gate Array with Dynamic Voltage and Frequency Scaling. ACTA ACUST UNITED AC 2015. [DOI: 10.1166/jolpe.2015.1406] [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: 11/23/2022]
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9
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Teoh H, Chong P, Sekawi Z, Abdullah M, Leong C, Cheong S. Inhibition of U266 cell growth by human mesenchymal stromal cell-mediated small interfering RNA silencing of interleukin-6. Cytotherapy 2014. [DOI: 10.1016/j.jcyt.2014.01.111] [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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Batista A, Leong C, Bexiga V, Rodrigues A, Combo A, Carvalho B, Fortunato J, Correia M, Teixeira J, Teixeira I, Sousa J, Gonçalves B, Varandas C. ATCA/AXIe compatible board for fast control and data acquisition in nuclear fusion experiments. Fusion Engineering and Design 2012. [DOI: 10.1016/j.fusengdes.2012.05.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Tey J, Koh W, Leong C, Choo B, Wong L, Lu J. Clinical Outcome of Palliative Radiation Therapy in Locally Advanced, Symptomatic Gastric Cancer in the Modern Era. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.825] [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: 11/30/2022]
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12
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Chia D, Lu J, Leong C, Wong L, Tan G, Tey J. Efficacy of Palliative Radiation Therapy in Symptomatic Rectal Cancer in the Modern Era. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.901] [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: 10/27/2022]
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13
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Pong Y, Wang L, Huang Y, Leong C, Liaw M, Chen H. Sonography and physical findings in stroke patients with hemiplegic shoulders: A longitudinal study. J Rehabil Med 2012; 44:553-7. [DOI: 10.2340/16501977-0987] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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14
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Elmer S, Hahn S, McAllister P, Leong C, Martin J. Improvements in multi-joint leg function following chronic eccentric exercise. Scand J Med Sci Sports 2011; 22:653-61. [DOI: 10.1111/j.1600-0838.2011.01291.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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15
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Isakoff SJ, Leong C, Vidnovic N, DeYoung MP, Sgroi D, Goss PE, Ryan PD, Ellisen LW. p63/p73 expression mediates cisplatin sensitivity in a subset of triple-negative primary breast cancer: Implications for a new clinical trial. J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.10522] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
10522 Background: Triple-negative breast cancer (ER-, PgR- and HER2-negative) has a poor prognosis relative to other subtypes, even with the best available chemotherapy. We recently reported that in squamous cell cancers, p63 promotes survival by direct interaction with and inhibition of p73-dependent apoptosis. We now report on the role of p63/p73 in triple-negative breast cancer. Methods: We performed quantitative RT-PCR on primary breast cancer specimens to determine the expression of specific p63 and p73 isoforms. Cell culture experiments used MCF7, HCC-1937, MDA-MB-468, T47D, and MCF10A cell lines. Lentiviral p63 and p73 shRNA were used for knockdown experiments. Chemotherapy dose-response curves were generated using MTT assay. Results: In primary tumors, ΔNp63 and TAp73 isoforms are expressed exclusively within a subset of triple-negative tumors in which p53 mutations are commonly found. Knockdown of p63 in triple-negative cell lines, but not the ER-positive MCF7 line, induced apoptosis which was specifically dependent on p73 expression. Breast cancer cell lines expressing p63/p73 exhibited p73-dependent sensitivity to cisplatin. Knockdown of p73 resulted in a 10–100 fold increase in the IC50 of cisplatin, but no change in doxorubicin or paclitaxel sensitivity. Exogenous p73 expression in MCF10A cells, which have high levels of p63 but no p73, confers increased sensitivity to cisplatin. Conclusion: These results show that p63/p73expression promotes survival in a subset of breast cancers, and they provide a mechanism for cisplatin sensitivity. These findings suggest that p63/p73 expression may serve as a biomarker to predict cisplatin sensitivity in triple-negative breast cancer. Based on these results, we are conducting a phase II study of 39 patients evaluating cisplatin as first line therapy for metastatic triple-negative breast cancer. The primary endpoints are overall objective response rate and response rate in low versus high p63/p73 expressing subgroups. No significant financial relationships to disclose.
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Affiliation(s)
- S. J. Isakoff
- Massachusetts General Hospital Cancer Center, Boston, MA
| | - C. Leong
- Massachusetts General Hospital Cancer Center, Boston, MA
| | - N. Vidnovic
- Massachusetts General Hospital Cancer Center, Boston, MA
| | - M. P. DeYoung
- Massachusetts General Hospital Cancer Center, Boston, MA
| | - D. Sgroi
- Massachusetts General Hospital Cancer Center, Boston, MA
| | - P. E. Goss
- Massachusetts General Hospital Cancer Center, Boston, MA
| | - P. D. Ryan
- Massachusetts General Hospital Cancer Center, Boston, MA
| | - L. W. Ellisen
- Massachusetts General Hospital Cancer Center, Boston, MA
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Abstract
Hepatocellular carcinoma (HCC) is the sixth most common cancer worldwide. OKL38 is a pregnancy-induced growth inhibitory gene and its expression is lost in various breast cancer cell lines and kidney tumor. To determine the role of OKL38 expression in HCC, we investigated its expression in various HCC samples and liver cancer cell lines. Western blot analysis revealed that OKL38 protein was absent or reduced in 64.2% (18 of 28) of the HCCs examined and four liver cancer cell lines. Immunohistochemistry study demonstrated that OKL38 protein was undetectable in 41.3% (38 of 92) of HCC, whereas 39.1% (36 of 92) of HCC showed low expression of the protein. Lost or reduced expression level of OKL38 protein was significantly correlated to high tumor stages in HCC (P=0.0042). Overexpression of the OKL38 caused cell death in Chang liver cells. 5' Untranslated region (5'UTR) deletion studies demonstrated that OKL38 was downregulated via translation suppression associated with the 5'UTR of its mRNA. Taken together, the 5'UTRs of OKL38 might play an important role in downregulation of its protein and the absence of OKL38 could lead to the development or progression of HCC.
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Affiliation(s)
- C K Ong
- Laboratory of Molecular Endocrinology, Division of Cellular and Molecular Research, National Cancer Centre of Singapore, Singapore, Singapore
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17
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Ash S, Reeves M, Bauer J, Dover T, Vivanti A, Leong C, O'Moore Sullivan T, Capra S. A randomised control trial comparing lifestyle groups, individual counselling and written information in the management of weight and health outcomes over 12 months. Int J Obes (Lond) 2006; 30:1557-64. [PMID: 16534529 DOI: 10.1038/sj.ijo.0803263] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To investigate the effect of an 8-week group-based cognitive behaviour therapy lifestyle intervention with monthly follow-up to 6 months and further follow up at 12 months on change in weight and other weight-related variables, change in physical activity and change in health and well being compared to individualised dietetic treatment or giving an information booklet only (BO). DESIGN A randomised controlled trial of two intervention groups, a group-based cognitive behaviour therapy lifestyle intervention, Fat Booters Incorporated--(FBI) and individualised dietetic treatment (IDT) and control group receiving an information booklet only (BO). The intervention groups involved weekly contact for 8 weeks with monthly follow-up to 6 months and further follow-up at 12 months, conducted in real practice setting. SUBJECTS A total of 176 adults with body mass index (BMI)>27 kg/m2, mean (+/-s.d.) age 48+/-13 years, mean BMI 34+/-5.5 kg/m2. MAIN OUTCOME MEASURES Weight, percent body fat, waist circumference, physical activity, health status, self-efficacy and satisfaction with life were measured at baseline, 3, 6 and 12 months. RESULTS A statistically significant difference between groups was observed for weight change over time (P=0.05). The change in weight (mean+/-s.e.) for the FBI group was significantly greater than the BO group at 3 and 12 months (-2.8+/-0.7 compared to -1.0+/-0.6 kg, P<0.05 and -2.9+/-0.9 compared to +0.5+/-0.9 kg, P<0.005, respectively). Change in weight in the IDT group did not differ from the FBI group at any time point. For all groups, waist circumference was significantly less than baseline at all time points (P<0.001). Significant differences in self-efficacy were observed over time (P=0.02), with both intervention groups having greater self-efficacy than the BO group. Significant drop-outs occurred over time for all three groups. CONCLUSIONS A cognitive behaviour-based lifestyle intervention was more effective than providing an information booklet alone and as effective as intensive individualised dietetic intervention in weight loss and improvements in self-efficacy.
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Affiliation(s)
- S Ash
- Princess Alexandra Hospital and Health Service District, Woolloongabba, Brisbane, Australia
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Davoine F, Sim A, Wierzbicki T, Leong C, Puttagunta L, McGaw T, Yu D, Moqbel R. Human Eosinophils Express Granzyme B and Perforin: Potential Role in Tumour Killing in Oral Squamous Cancer. J Allergy Clin Immunol 2006. [DOI: 10.1016/j.jaci.2005.12.064] [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: 11/30/2022]
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19
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Adams A, Leong C, Denny WA, Guss JM. Crystal structures of two minor groove binders complexed with d(CGCGAATTCGCG) 2. Acta Crystallogr A 2005. [DOI: 10.1107/s0108767305090707] [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: 11/10/2022] Open
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20
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Bradshaw T, Leong C, Suggitt M, Swaine D, Bibby M, Stevens M. 54 In vitro, in vivo and in silico examination of the activity of antitumor 2-(4-amino-3-methylphenyl)-5-fluorobenzothiazoles. EJC Suppl 2004. [DOI: 10.1016/s1359-6349(04)80062-4] [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: 11/26/2022] Open
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21
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Mukherjee S, Nelson D, Loh S, van Bruggen I, Palmer LJ, Leong C, Garlepp MJ, Robinson BW. The immune anti-tumor effects of GM-CSF and B7-1 gene transfection are enhanced by surgical debulking of tumor. Cancer Gene Ther 2001; 8:580-8. [PMID: 11571536 DOI: 10.1038/sj.cgt.7700347] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2001] [Indexed: 11/09/2022]
Abstract
Malignant mesothelioma (MM) is a solid tumor largely unresponsive to conventional therapies. Immunological gene therapy shows promise in murine models and human clinical trials; however, the role of surgery in combination with gene therapy has not been widely studied. The aim of this study was to determine if debulking surgery improved the effectiveness of gene therapy in a murine MM model. Mice were subcutaneously inoculated with the MM cell line, AC29, at two different sites, 4 days apart, to allow a surgical and distal site tumor to develop. Once tumors were established, the surgical site tumor was debulked and vaccination of syngeneic tumor transfectants encoding genes for IL-4, IL-2, GM-CSF, B7-1 or allogeneic MHC molecules commenced at a site away from both tumors, and tumor growth was measured. Neither debulking surgery nor gene therapy alone delayed tumor growth. However, there was a clear delay of tumor growth when debulking surgery was combined with vaccination of tumor transfectants expressing B7-1 or high levels of GM-CSF. Combinations of these two transfectants did not lead to a synergistic effect. This study demonstrates that debulking surgery can augment the immunostimulatory effects of immunological gene therapy and can delay tumor growth. This has implications for the future design of human gene therapy trials for solid tumors such as MM.
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Affiliation(s)
- S Mukherjee
- Department of Medicine, University of Western Australia, Perth, Australia.
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22
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Dixon P, Brundage M, Palmer M, Zee B, Peter J, Leong C, Mulroy L, Wright J, Grafton C, Blood P, Lochrin C. Characteristics of lung cancer patients entered on a Canadian palliative radiotherapy study (National Cancer Institute of Canada Clinical Trials Group (NCIC CTG) SC.15 study). Lung Cancer 2000. [DOI: 10.1016/s0169-5002(00)80578-4] [Citation(s) in RCA: 2] [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: 11/25/2022]
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23
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Guo B, Dai JR, Ng S, Huang Y, Leong C, Ong W, Carté BK. Cytonic acids A and B: novel tridepside inhibitors of hCMV protease from the endophytic fungus Cytonaema species. J Nat Prod 2000; 63:602-604. [PMID: 10843568 DOI: 10.1021/np990467r] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Two novel human cytomegalovirus protease inhibitors, cytonic acids A (1) and B (2), have been isolated from the solid-state fermentation of the endophytic fungi Cytonaema sp. Their structures as p-tridepside isomers were elucidated by MS and NMR methods.
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Affiliation(s)
- B Guo
- Centre for Natural Product Research, Institute of Molecular and Cell Biology, 59A Science Park Drive, The Fleming, Singapore Science Park, Singapore 118240.
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Matson MB, Jarosz JM, Gallacher D, Malcolm PN, Holemans JA, Leong C, Seed PT, Ayers AB, Rankin SC. Evaluation of head examinations produced with a mobile CT unit. Br J Radiol 1999; 72:631-6. [PMID: 10624318 DOI: 10.1259/bjr.72.859.10624318] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Recent years have seen the development of mobile CT units, designed for use in operating theatres, intensive care units and accident and emergency departments. One such unit is the Tomoscan M (Philips, Utrecht, The Netherlands). It operates with a maximum tube voltage of 130 kV, and a maximum tube current of only 50 mA. This study tested whether acceptable quality CT images of the brain could be produced on the mobile unit with these parameters. 44 consecutive normal head examinations performed on the mobile scanner were compared with 35 examinations from two conventional CT units. Two independent readers scored the examinations for noise and artefact. CT dose index (CTDI) values for the three CT units were obtained in free air as an estimate of patient dose. Differences in artefact score between CT units were generally small, but noise scores were worse when using the Tomoscan M with a 2 s slice time. The lowest CTDI values were obtained with the Somatom DRH (Siemens, Erlangen, Germany) unit and the highest with the SR 7000 (Philips, Utrecht, The Netherlands), with values from Tomoscan M, in all except one case, falling between these values for the protocols used in the study. The measured scattered radiation doses from the Tomoscan M are presented.
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Affiliation(s)
- M B Matson
- Department of Radiology, Guy's Hospital, London, UK
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25
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Robinson BW, Mukherjee SA, Davidson A, Morey S, Musk AW, Ramshaw I, Smith D, Lake R, Haenel T, Garlepp M, Marley J, Leong C, Caminschi I, Scott B. Cytokine gene therapy or infusion as treatment for solid human cancer. J Immunother 1998; 21:211-7. [PMID: 9610913 DOI: 10.1097/00002371-199805000-00007] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In the induction of tissue-directed immune responses, cytokines tend to be released within the affected tissues. We used two strategies to expose tumor tissues to continuous high levels of cytokines: First, a vaccinia interleukin (IL)2 recombinant was injected directly intratumorally 3-weekly at 10(7) pfus/dose in six patients with the solid tumor malignant mesothelioma (MM). No virus excretion was detectable. At each cycle vaccinia-IL-2 mRNA (SQ [semi-quantitative] reverse transcription polymerase chain reaction) was maximal 24-72 h following injection reduced at 8 days and faded by 21 days. No tumor regression occurred. Second, based on the success of granulocyte macrophage colony-stimulating factor (GM-CSF) in gene transfer experiments, we conducted a study using continuous intratumoral GM-CSF infusion in eight patients with MM using a portable pump at doses of 10 micro/cg/24 h over 8 weeks. Systemic neutrophil agglutination and local catheter-related difficulties occurred. Two patients demonstrated tumor necrosis, one of whom had a marked progressive mononuclear cell infiltration of the tumor associated with a partial response (>50% reduction in tumor area). Murine studies using our MM model in CBA and BALB/C mice have demonstrated that B7-1 and allo-class I transfections induce strong tumor-specific cytotoxic T lymphocyte responses: GM-CSF, IL-12, and IL-2 induced mixed nonspecific plus specific responses, whereas B7-2 and class II transfections were not effective. We conclude that increased intratumoral cytokine concentrations can be generated using both gene transfer and cytokine infusion approaches; however, both have their limitations and, at this stage, have not produced dramatic antitumor effects in humans.
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Affiliation(s)
- B W Robinson
- University Department of Medicine, Sir Charles Gairdner Hospital, Queen Elizabeth II Medical Centre, Perth, Australia
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26
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Lanier LL, Corliss BC, Wu J, Leong C, Phillips JH. Immunoreceptor DAP12 bearing a tyrosine-based activation motif is involved in activating NK cells. Nature 1998; 391:703-7. [PMID: 9490415 DOI: 10.1038/35642] [Citation(s) in RCA: 656] [Impact Index Per Article: 25.2] [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: 02/06/2023]
Abstract
Natural killer (NK) cells express cell-surface receptors of the immunoglobulin and C-type lectin superfamilies that recognize major histocompatibility complex (MHC) class I peptides and inhibit NK-cell-mediated cytotoxicity. These inhibitory receptors possess ITIM sequences (for immunoreceptor tyrosine-based inhibitory motifs) in their cytoplasmic domains that recruit SH2-domain-containing protein tyrosine phosphatases, resulting in inactivation of NK cells. Certain isoforms of these NK-cell receptors lack ITIM sequences and it has been proposed that these 'non-inhibitory' receptors may activate, rather than inhibit, NK cells. Here we show that DAP12, a disulphide-bonded homodimer containing an immunoreceptor tyrosine-based activation motif (ITAM) in its cytoplasmic domain, non-covalently associates with membrane glycoproteins of the killer-cell inhibitory receptor (KIR) family without an ITIM in their cytoplasmic domain. Crosslinking of KIR-DAP12 complexes results in cellular activation, as demonstrated by tyrosine phosphorylation of cellular proteins and upregulation of early-activation antigens. Phosphorylated DAP12 peptides bind ZAP-70 and Syk protein tyrosine kinases, suggesting that the activation pathway is similar to that of the T- and B-cell antigen receptors.
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MESH Headings
- Amino Acid Sequence
- Animals
- B-Lymphocytes/metabolism
- Base Sequence
- Binding Sites
- Cell Line
- Cell Membrane/metabolism
- Chromosomes, Human, Pair 19
- Consensus Sequence
- Cross-Linking Reagents
- Cytoplasm/metabolism
- DNA, Complementary
- Humans
- Jurkat Cells
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Lymphocyte Activation
- Mice
- Molecular Sequence Data
- Protein-Tyrosine Kinases/metabolism
- Receptors, Antigen/metabolism
- Receptors, Immunologic/chemistry
- Receptors, Immunologic/genetics
- Receptors, Immunologic/metabolism
- Receptors, KIR
- T-Lymphocytes/metabolism
- Transfection
- Tyrosine/metabolism
- ZAP-70 Protein-Tyrosine Kinase
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Affiliation(s)
- L L Lanier
- DNAX Research Institute of Molecular and Cellular Biology, Department of Immunobiology, Palo Alto, California 94304, USA.
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27
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Leong C, Marley J, Loh S, Robinson B, Garlepp M. Induction and maintenance of T-cell response to a nonimmunogenic murine mesothelioma cell line requires expression of B7-1 and the capacity to upregulate class II major histocompatibility complex expression. Cancer Gene Ther 1996; 3:321-30. [PMID: 8894251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Intratumoral expression of the T-cell costimulator B7-1 has been reported to induce tumor-specific immunity against immunogenic, but not nonimmunogenic, tumors. We transfected the B7-1 gene into a nonimmunogenic murine mesothelioma cell line that constitutively expresses high levels of class I major histocompatibility complex (MHC) and transforming growth factor-beta (TGF-beta). Tumor development by two of the four B7-1 transfectant clones was markedly delayed, although all clones eventually formed tumors. Retardation of tumor growth required both CD4+ and CD8+ T cells. Tumor-specific cytotoxic T-lymphocytes (CTLs) were elicited in response to the least (AC29-B7-6), but not the most (AC29-B7-7), tumorigenic transfectant clone. Tumor-specific CTL activity could be detected at early time points but not at the time of tumor outgrowth. This lack of responsiveness was tumor antigen specific. Differences in immunogenicity of transfectant clones did not relate to the level of expression of MHC class I, vascular cell adhesion molecule-1, or transfected B7-1, or to the level of TGF-beta secreted. Class II MHC expression was most readily inducible in those transfectant clones whose growth in vivo was most delayed. An explant cell line derived from a tumor that developed from AC29-B7-6 had a markedly reduced capacity to upregulate MHC class II expression and produced tumors in vivo at a faster rate than did the parental cell line. Thus, B7-1 expression in this nonimmunogenic tumor cell line can promote the generation of tumor-specific CTLs with consequent retardation of tumor development, and coexpression of MHC class II seems likely to play an important role in this process. This work also illustrates that clonal heterogeneity within a single tumor and the development of immunological nonresponsiveness resulting in tumor outgrowth, even in the presence of continued B7-1 expression, are potential difficulties associated with this therapeutic approach.
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Affiliation(s)
- C Leong
- Australian Neuromuscular Research Institute, Queen Elizabeth II Medical Centre, Nedlands, Australia
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Leong C, McKenzie MR, Coupland DB, Gascoyne RD. Disseminated intravascular coagulation in a patient with metastatic prostate cancer: fatal outcome following strontium-89 therapy. J Nucl Med 1994; 35:1662-4. [PMID: 7931669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A patient with metastatic prostate cancer was found to have low-grade disseminated intravascular coagulation (DIC). He had significant bone pain despite external-beam radiotherapy and was given 89Sr with subsequent thrombocytopenia and epistaxis. The patient died from generalized hemorrhage 36 days postinjection. Although it is not possible to establish a causal relationship between the 89Sr and DIC, practitioners should be alert to complications associated with the primary disorder which might occur at a time to raise concern about the intervention.
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Affiliation(s)
- C Leong
- University of British Columbia, Division of Radiation Oncology, Vancouver, Canada
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Pilote L, Thomas RJ, Dennis C, Goins P, Houston-Miller N, Kraemer H, Leong C, Berger WE, Lew H, Heller RS. Return to work after uncomplicated myocardial infarction: a trial of practice guidelines in the community. Ann Intern Med 1992; 117:383-9. [PMID: 1503329 DOI: 10.7326/0003-4819-117-5-383] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE To evaluate the effectiveness of practice guidelines for return to work after acute myocardial infarction when disseminated from a university-based setting to a practice-based setting. DESIGN Randomized clinical trial. PATIENTS A total of 187 patients with uncomplicated acute myocardial infarction. INTERVENTION Patients were randomly assigned to the intervention (n = 95) or to usual care (n = 92). The intervention consisted of a treadmill test, a counseling session based on the test results, and a consultation letter from a cardiologist to the primary care physician. Individualized recommendations for the timing of return to work, contained in the consultation letter, were based on the patient's risk for recurrent cardiac events. MEASUREMENTS Questionnaire, chart review, and a phone interview documented the timing of return to work and the rates of cardiac death, coronary angioplasty, coronary artery surgery, and recurrent myocardial infarction. RESULTS Median intervals between acute myocardial infarction and return to work were similar in both groups (intervention, 54 days; usual care, 67 days; P greater than 0.2). Among patients without myocardial ischemia, however, the interval was shorter in the intervention group than in the usual care group (38 days compared with 65 days, respectively, P = 0.008). Among patients with myocardial ischemia, intervals were similar in both groups (80 days compared with 76 days, respectively, P greater than 0.2). CONCLUSION Practice guidelines developed in a university-based setting were not as successful in hastening return to work after uncomplicated acute myocardial infarction when tested in a practice-based setting. Physicians' reluctance to follow guidelines for patients with myocardial ischemia reflected their concern with prognosis even though medical outcome was good.
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Affiliation(s)
- L Pilote
- Stanford University School of Medicine, California
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Ratcliff PA, Leong C. Anxiety in the dental office. CDA J 1988; 16:52-3. [PMID: 3164660] [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: 01/04/2023]
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Abstract
Ceftazidime was prospectively evaluated in the treatment of bacterial meningitis in 19 pediatric patients. Haemophilus influenzae type b (HIB) was the etiologic agent in 17 patients, and Streptococcus pneumonia and Neisseria meningitidis were the etiologic agents in one patient each. Ceftazidime was administered intravenously in a dosage of 150 mg/kg/day divided into eight hourly doses for a mean of 15 days (range, 14 to 22 days) for H. influenzae type b meningitis. The clinical and microbiologic response was appropriate in all cases. The mean ceftazidime CSF concentration was 6.7 micrograms/ml at approximately 2 hours following iv infusions. This concentration was 16- to greater than 100-fold the minimal bactericidal concentration determined for the isolated pathogens. These preliminary observations support ceftazidime as a candidate cephalosporin for the treatment of bacterial meningitis caused by H. influenzae. Additional study is required to further define its role in meningitis caused by S. pneumoniae and N. meningitidis.
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Tung KS, Leong C, McCarty T. Pathogenesis of experimental allergic orchitis. III. T lymphocyte requirement in local adoptive transfer by peritoneal exudate cells. J Immunol 1977; 118:1774-9. [PMID: 300759] [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: 12/14/2022]
Abstract
In experimental allergic orchitis (EAO), a lesion characterized by mononuclear invasion of seminiferous tubules can be adoptively transferred within 1 to 4 days by testicular injection of peritoneal exudate cells (PEC) from syngeneic strain 13 guinea pigs (GP) immunized with homologous testicular antigens in complete Freund's adjuvant (CFA). This study examined the role of T lymphocytes, macrophages, and polymorphonuclear neutrophils (PMN) in the adoptive transfer. Guinea pig PEC contained 7% T lymphocytes, rare B lymphocytes, and over 90% of macrophages and PMN. After T lymphocytes were depleted by rabbit erythrocyte (E) rosette and Hypaque-Ficoll gradient centrifugation, cell preparations that contained 73% of original macrophages and 15% original T lymphocytes were obtained, and these cells did not transfer EAO (0 of 18 testes). In contrast, cell preparations enriched in T lymphocytes by nylon wool column or E rosette contained 1.5% of the original macrophages and 59% of the original T lymphocytes transferred EAO to 70% of the testes, starting at 1.5 x 10(6) T lymphocytes per testis. The number of T lymphocytes correlated with the incidence of adoptive transfer; the correlation existed regardless of the number of macrophages or PMN present. Finally, EAO was adoptively transferred to recipients that had total-body irradiation. The results indicate that (a) T lymphocytes are capable of transferring lesions of EAO, (b) in the transfer, the T lymphocytes did not function as helper T cells, since the transfer need not involve participation of host lymphoid cells, and (c) by inference, testis antigen-reactive T lymphocytes exist.
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Leong C. Spectrophotometric determination of germanium with Catechol Violet and cetyltrimethylammonium bromide. Talanta 1971; 18:845-8. [DOI: 10.1016/0039-9140(71)80137-6] [Citation(s) in RCA: 13] [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] [Received: 09/03/1970] [Accepted: 11/17/1970] [Indexed: 11/17/2022]
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