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Steventon L, Nicum S, Man K, Chaichana U, Wei L, Chambers P. A systematic review of ethnic minority participation in randomised controlled trials of systemic therapies for gynecological cancers. Gynecol Oncol 2024; 184:178-189. [PMID: 38330832 DOI: 10.1016/j.ygyno.2024.01.052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/10/2024] [Accepted: 01/30/2024] [Indexed: 02/10/2024]
Abstract
OBJECTIVE Randomised controlled trials (RCTs) must include ethnic minority patients to produce generalisable findings and ensure health equity as cancer incidence rises globally. This systematic review examines participation of ethnic minorities in RCTs of licensed systemic anti-cancer therapies (SACT) for gynecological cancers, defining the research population and distribution of research sites to identify disparities in participation on the global scale. METHODS A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Phase II and III RCTs of licensed therapies for gynecological cancers published 01/11/2012-01/11/2022 that reported patient race/ethnicity were included. Extracted data included race/ethnicity and research site location. RCT populations were aggregated and participation of groups compared. Global distribution of research sites was described. RESULTS 26 RCTs met inclusion criteria of 351 publications included in full-text screening, representing 17,041 patients. 79.8% were "Caucasian", 9.1% "East Asian", 3.7% "Black/African American" and 6.1% "Other, Unknown, Not Reported". "Caucasian" patients participated at higher rates than all other groups. Of 5,478 research sites, 80.1% were located in North America, 13.0% in Europe, 3.4% in East Asia, 1.3% in the Middle East, 1.3% in South America and 0.8% in Australasia. CONCLUSIONS Ethnic minorities formed smaller proportions of RCT cohorts compared to the general population. The majority of sites were located in North America and Europe, with few in other regions, limiting enrollment of South Asian, South-East Asian and African patients in particular. Efforts to recruit more ethnic minority patients should be made in North America and Europe. More sites in underserved regions would promote equitable access to RCTs and ensure findings are generalisable to diverse groups. This review assessed the global population enrolled in contemporary RCTs for novel therapies now routinely given for gynecological cancers, adding novel understanding of the global distribution of research sites.
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Affiliation(s)
- Luke Steventon
- UCL School of Pharmacy, Mezzanine Floor, BMA House, Tavistock Square, London WC1H 9EU, United Kingdom; University College London Hospitals NHS Foundation Trust, Medical Oncology Department, 250 Euston Road, London NW1 2PG, United Kingdom
| | - Shibani Nicum
- University College London Hospitals NHS Foundation Trust, Medical Oncology Department, 250 Euston Road, London NW1 2PG, United Kingdom; UCL Cancer Institute, Department of Oncology, 72 Huntley Street, London WC1 6DD, United Kingdom
| | - Kenneth Man
- UCL School of Pharmacy, Mezzanine Floor, BMA House, Tavistock Square, London WC1H 9EU, United Kingdom
| | - Ubonphan Chaichana
- UCL School of Pharmacy, Mezzanine Floor, BMA House, Tavistock Square, London WC1H 9EU, United Kingdom
| | - Li Wei
- UCL School of Pharmacy, Mezzanine Floor, BMA House, Tavistock Square, London WC1H 9EU, United Kingdom
| | - Pinkie Chambers
- UCL School of Pharmacy, Mezzanine Floor, BMA House, Tavistock Square, London WC1H 9EU, United Kingdom; University College London Hospitals NHS Foundation Trust, Medical Oncology Department, 250 Euston Road, London NW1 2PG, United Kingdom.
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Khera R, Dhingra L, Li K, Aminorroaya A, Zhou J, Arshad F, Bu F, Dorr D, Falconer T, French T, Lau W, Lu Y, Man K, Matheny ME, Minty E, Nishimura A, Ostropolets A, Seager S, Y.F. WE, Yang J, Yin C, Hripcsak G, Krumholz HM. MULTINATIONAL PATTERNS OF SECOND-LINE ANTI-HYPERGLYCEMIC DRUG INITIATION IN ESTABLISHED CARDIOVASCULAR DISEASE: A FEDERATED PHARMACOEPIDEMIOLOGIC EVALUATION IN LEGEND-T2DM. J Am Coll Cardiol 2023. [DOI: 10.1016/s0735-1097(23)02090-9] [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: 03/06/2023]
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Cheng CS, Tan HY, Zhang C, Chan YT, Zhang ZJ, Man K, Yuen MF, Wang N, Feng Y. Berberine suppresses metastasis and recurrence of hepatocellular carcinoma by targeting circulating tumour cells: abridged secondary publication. Hong Kong Med J 2022; 28 Suppl 6:10-11. [PMID: 36535791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Affiliation(s)
- C S Cheng
- School of Chinese Medicine, The University of Hong Kong
| | - H Y Tan
- School of Chinese Medicine, The University of Hong Kong
| | - C Zhang
- School of Chinese Medicine, The University of Hong Kong
| | - Y T Chan
- School of Chinese Medicine, The University of Hong Kong
| | - Z J Zhang
- School of Chinese Medicine, The University of Hong Kong
| | - K Man
- Department of Surgery, The University of Hong Kong
| | - M F Yuen
- Department of Medicine, The University of Hong Kong
| | - N Wang
- School of Chinese Medicine, The University of Hong Kong
| | - Y Feng
- School of Chinese Medicine, The University of Hong Kong
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Raison N, Musollari G, Man K, Bhate N, Forde A, Sethi J, Ahmed H, Morley R, Rashid T, Winkler M. Patient-specific risk factors and post-operative complications have a significant impact on long term functional outcomes following minimally invasive. Eur Urol 2021. [DOI: 10.1016/s0302-2838(21)01526-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Webster-Clark M, Stürmer T, Wang T, Man K, Marinac-Dabic D, Rothman KJ, Ellis AR, Gokhale M, Lunt M, Girman C, Glynn RJ. Using propensity scores to estimate effects of treatment initiation decisions: State of the science. Stat Med 2020; 40:1718-1735. [PMID: 33377193 DOI: 10.1002/sim.8866] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 12/11/2020] [Accepted: 12/14/2020] [Indexed: 02/02/2023]
Abstract
Confounding can cause substantial bias in nonexperimental studies that aim to estimate causal effects. Propensity score methods allow researchers to reduce bias from measured confounding by summarizing the distributions of many measured confounders in a single score based on the probability of receiving treatment. This score can then be used to mitigate imbalances in the distributions of these measured confounders between those who received the treatment of interest and those in the comparator population, resulting in less biased treatment effect estimates. This methodology was formalized by Rosenbaum and Rubin in 1983 and, since then, has been used increasingly often across a wide variety of scientific disciplines. In this review article, we provide an overview of propensity scores in the context of real-world evidence generation with a focus on their use in the setting of single treatment decisions, that is, choosing between two therapeutic options. We describe five aspects of propensity score analysis: alignment with the potential outcomes framework, implications for study design, estimation procedures, implementation options, and reporting. We add context to these concepts by highlighting how the types of comparator used, the implementation method, and balance assessment techniques have changed over time. Finally, we discuss evolving applications of propensity scores.
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Affiliation(s)
| | - Til Stürmer
- Department of Epidemiology, UNC Chapel Hill, Chapel Hill, North Carolina, USA
| | - Tiansheng Wang
- Department of Epidemiology, UNC Chapel Hill, Chapel Hill, North Carolina, USA
| | - Kenneth Man
- Research Department of Practice and Policy, UCL School of Pharmacy, London, UK.,Department of Pharmacology and Pharmacy, LKS Faculty of Medicine, University of Hong Kong, Hong Kong
| | - Danica Marinac-Dabic
- Office of Clinical Evidence and Analysis, FDA Center for Devices and Radiological Health, Silver Springs, Maryland, USA
| | - Kenneth J Rothman
- RTI Health Solutions, Raleigh, North Carolina, USA.,Department of Epidemiology, Boston University, Boston, Massachusetts, USA
| | - Alan R Ellis
- Department of Social Work, NC State University, Raleigh, North Carolina, USA
| | - Mugdha Gokhale
- Department of Epidemiology, UNC Chapel Hill, Chapel Hill, North Carolina, USA.,Pharmacoepidemiology, Center for Observational & Real-World Evidence, Merck, West Point, Pennsylvania, USA
| | - Mark Lunt
- The Arthritis Research UK Epidemiology Unit, University of Manchester, Manchester, UK
| | - Cynthia Girman
- Department of Epidemiology, UNC Chapel Hill, Chapel Hill, North Carolina, USA.,CERobs Consulting, LLC, Chapel Hill, North Carolina, USA
| | - Robert J Glynn
- Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Man K, Lo CM, Liu XB. M2 macrophages on tumour growth and metastasis in hepatocellular carcinoma. Hong Kong Med J 2019; 25 Suppl 9:35-39. [PMID: 31889034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023] Open
Affiliation(s)
- K Man
- Department of Surgery, The University of Hong Kong
| | - C M Lo
- Department of Surgery, The University of Hong Kong
| | - X B Liu
- Department of Surgery, The University of Hong Kong
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Prentice M, Man K, Jani Y, Payne HA, Wong I. Computer modelling in prostate anticancer therapy (COMPACT). J Clin Oncol 2019. [DOI: 10.1200/jco.2019.37.15_suppl.e16528] [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: 11/20/2022] Open
Abstract
e16528 Background: Prostate cancer is the most common solid malignancy in men and despite improving radical therapies a proportion of patients will develop castrate resistant metastatic disease (mCRPC). Therapeutic options in mCRPC include abiraterone acetate and prednisolone (AA+P), enzalutamide (E) and docetaxel (D) with limited evidence to guide clinical choice between agents. COMPACT aims to collate data from multiple data sets within one hospital to assess clinical or biochemical factors that may guide therapeutic strategy. Methods: Data was collated on all patients recorded as receiving therapy with AA+P, E or D in the metastatic castrate resistant setting from the chemotherapy prescribing and dispensing systems and the pathology system at University College Hospital, London. Individual clinical notes were reviewed to determine the reason for stopping therapies. Data was collated in one dataset and analysed to present baseline demographic data. The log-rank test was used to analyse differences in the retention rate among AA+P, E and D. Results: 598 individual treatments were identified in 441 patients. 172 patients received AA+P, 119 E and 307 D with a mean age at treatment initiation of 74.1, 76.8 and 69.5 years respectively. Of the 144 patients receiving two or more treatment lines, 62% (n = 89) received D prior to either AA+P or E. E was first line therapy in 18% (n = 26) and AA+P in 20% (n = 29). 5 (3.5%) patients transferred directly from AA+P to E and 12 (8%) from E to AA+P. Kaplan Meir estimates for time to retention show no statistically significant differences when directly comparing AA+P, E and D on univariate analysis with chi squared test (AA+P vs E = 0.3609, p = 0.558 D vs E = 0.365, p = 0.5457, D vs AA+P = 0.0136 p = 0.9072). Conclusions: The COMPACT study has confirmed that it is feasible for single institutions to retrospectively review real world data from different sources, combining it into a workable database. Patient numbers were sufficient to statistically analyse the data for specific clinical factors that may correlate to a prolonged biochemical response to AA+P, E or D therapy. The failure to detect a statistically significant difference between therapies on univariate analysis may confirm that all three are acceptable treatments in mCRPC.
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Affiliation(s)
| | - Kenneth Man
- University College London School of Pharmacy, London, United Kingdom
| | - Yogini Jani
- University College London SChool of Pharmacy, London, United Kingdom
| | - Heather Ann Payne
- University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Ian Wong
- University College London, School of Pharmacy, London, United Kingdom
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Bai JW, Chen MN, Wei XL, Li YC, Lin HY, Chen M, Li JW, Du CW, Man K, Zhang GJ. The zinc-finger transcriptional factor Slug transcriptionally downregulates ERα by recruiting lysine-specific demethylase 1 in human breast cancer. Oncogenesis 2017; 6:e330. [PMID: 28481366 PMCID: PMC5523071 DOI: 10.1038/oncsis.2017.38] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Revised: 03/02/2017] [Accepted: 03/28/2017] [Indexed: 02/07/2023] Open
Abstract
Estrogen receptor α (ERα) is related with epithelial-mesenchymal transition, invasion and metastasis, and serves as an important therapeutic predictor and prognostic factor in breast cancer patients. The triple negative breast cancer (TNBC) is characterized by loss of hormone receptors and human epidermal growth factor receptor 2 (Her2), and lacks effective targeted therapy with poor prognosis. Unfortunately, the molecular mechanisms of ERα deficiency, which becomes hormone independent and results in resistance to endocrine therapy, remain to be elucidated in breast cancer. In this study, we observed an inverse correlation between Slug, a zinc-finger transcriptional repressor, and ERα expression in both human breast cancer tissues and cell lines. In ERα-negative breast cancer patients, high Slug messenger RNA expression showed obviously shorter relapse-free survival. We found that Slug binds to the E-box located in the promoter of estrogen receptor 1 gene (ESR1) to suppress its expression. More specifically, Slug recruits lysine-specific demethylase 1 (LSD1) to the E-box and thereby inhibits ERα expression by demethylating H3K4me2, which is evidenced by the interaction between Slug and LSD1. Moreover, the amount of H3K4me2 binding to the E-box was significantly increased after LSD1 knockdown in MDA-MB-231 cells. Functionally, the ability to proliferate, invade and metastasize was significantly suppressed after knockdown of either Slug or LSD1 alone, or both simultaneously. Taken together, these results suggest that Slug transcriptionally inhibits ERα expression by recruiting LSD1 to the ESR1 promoter in breast cancers. Thus, targeted inhibition of Slug and LSD1 may restore ERα and lead to resensitization to hormone therapy, providing a novel therapeutic strategy for ERα-negative breast cancer patients, especially for TNBC.
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Affiliation(s)
- J-W Bai
- The Breast Center, Cancer Hospital of Shantou University Medical College (SUMC), Shantou, China
- ChangJiang Scholar’s Laboratory of SUMC, Shantou, China
| | - M-N Chen
- The Breast Center, Cancer Hospital of Shantou University Medical College (SUMC), Shantou, China
- ChangJiang Scholar’s Laboratory of SUMC, Shantou, China
| | - X-L Wei
- The Breast Center, Cancer Hospital of Shantou University Medical College (SUMC), Shantou, China
- ChangJiang Scholar’s Laboratory of SUMC, Shantou, China
- Department of Pathology, Cancer Hospital of SUMC, Shantou, China
| | - Y-Ch Li
- ChangJiang Scholar’s Laboratory of SUMC, Shantou, China
| | - H-Y Lin
- The Breast Center, Cancer Hospital of Shantou University Medical College (SUMC), Shantou, China
- ChangJiang Scholar’s Laboratory of SUMC, Shantou, China
- Department of Breast and Thyroid Surgery, The First Affiliated Hospital of SUMC, Shantou, China
| | - M Chen
- ChangJiang Scholar’s Laboratory of SUMC, Shantou, China
| | - J-W Li
- The Breast Center, Cancer Hospital of Shantou University Medical College (SUMC), Shantou, China
- ChangJiang Scholar’s Laboratory of SUMC, Shantou, China
| | - C-W Du
- The Breast Center, Cancer Hospital of Shantou University Medical College (SUMC), Shantou, China
- Department of Breast Medical Oncology, Cancer Hospital of SUMC, Shantou, China
| | - K Man
- Department of Surgery, HongKong University Li Ka-Tsing Faculty of Medicine, Hongkong, China
| | - G-J Zhang
- The Breast Center, Cancer Hospital of Shantou University Medical College (SUMC), Shantou, China
- ChangJiang Scholar’s Laboratory of SUMC, Shantou, China
- The Breast Center and ChangJiang Scholar’s Laboratory, Cancer Hospital of Shantou University Medical College, 7 Raoping Road, Shantou, 515041 Guangdong, China. E-mail:
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Mackay LK, Minnich M, Kragten NAM, Liao Y, Nota B, Seillet C, Zaid A, Man K, Preston S, Freestone D, Braun A, Wynne-Jones E, Behr FM, Stark R, Pellicci DG, Godfrey DI, Belz GT, Pellegrini M, Gebhardt T, Busslinger M, Shi W, Carbone FR, van Lier RAW, Kallies A, van Gisbergen KPJM. Hobit and Blimp1 instruct a universal transcriptional program of tissue residency in lymphocytes. Science 2016; 352:459-63. [DOI: 10.1126/science.aad2035] [Citation(s) in RCA: 553] [Impact Index Per Article: 69.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 03/21/2016] [Indexed: 12/12/2022]
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Tan HY, Wang N, Man K, Tsao SW, Che CM, Feng Y. Autophagy-induced RelB/p52 activation mediates tumour-associated macrophage repolarisation and suppression of hepatocellular carcinoma by natural compound baicalin. Cell Death Dis 2015; 6:e1942. [PMID: 26492375 PMCID: PMC4632300 DOI: 10.1038/cddis.2015.271] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Revised: 08/06/2015] [Accepted: 08/24/2015] [Indexed: 12/16/2022]
Abstract
The plasticity of tumour-associated macrophages (TAMs) has implicated an influential role in hepatocellular carcinoma (HCC). Repolarisation of TAM towards M1 phenotype characterises an immune-competent microenvironment that favours tumour regression. To investigate the role and mechanism of TAM repolarisation in suppression of HCC by a natural compound baicalin, Orthotopic HCC implantation model was used to investigate the effect of baicalin on HCC; liposome-clodronate was introduced to suppress macrophage populations in mice; bone marrow-derived monocytes (BMDMs) were induced to unpolarised, M1-like, M2-like macrophages and TAM using different conditioned medium. We observed that oral administration of baicalin (50 mg/kg) completely blocked orthotopic growth of implanted HCC. Suppression of HCC by baicalin was diminished when mice macrophage was removed by clodronate treatment. Baicalin induced repolarisation of TAM to M1-like phenotype without specific toxicity to either phenotype of macrophages. Baicalin initiated TAM reprogramming to M1-like macrophage, and promoted pro-inflammatory cytokines production. Co-culturing of HCC cells with baicalin-treated TAMs resulted in reduced proliferation and motility in HCC. Baicalin had minimal effect on derivation of macrophage polarisation factors by HCC cells, while directly induced repolarisation of TAM and M2-like macrophage. This effect was associated with elevated autophagy, and transcriptional activation of RelB/p52 pathway. Suppression of autophagy or RelB abolished skewing of baicalin-treated TAM. Autophagic degradation of TRAF2 in baicalin-treated TAM might be responsible for RelB/p52 activation. Our findings unveil the essential role of TAM repolarisation in suppressive effect of baicalin on HCC, which requires autophagy-associated activation of RelB/p52.
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Affiliation(s)
- H-Y Tan
- School of Chinese Medicine, The University of Hong Kong, Hong Kong, China
| | - N Wang
- School of Chinese Medicine, The University of Hong Kong, Hong Kong, China
| | - K Man
- Department of Surgery, The University of Hong Kong, Hong Kong, China
| | - S-W Tsao
- Department of Anatomy, The University of Hong Kong, Hong Kong, China
| | - C-M Che
- State Key Laboratory of Synthetic Chemistry, Chemical Biology Center and Department of Chemistry, The University of Hong Kong, Hong Kong, China
| | - Y Feng
- School of Chinese Medicine, The University of Hong Kong, Hong Kong, China
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Qi X, Ng K, Li C, Liu X, Geng W, Ling C, Ma Y, Yeung W, Liu H, Fan S, Lo C, Man K. Hepatic Senescence Associated Down-Regulation of Glutathione Peroxidase 3 (GPx3) Promoted Tumor Recurrence After Living Donor Liver Transplantation. Transplantation 2014. [DOI: 10.1097/00007890-201407151-02979] [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: 11/25/2022]
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Lam C, Muraj Z, Man K, Milosevic M. EP-1306: Near misses reflect different failure modes than actual incidents in the field of radiation therapy. Radiother Oncol 2013. [DOI: 10.1016/s0167-8140(15)33612-4] [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: 10/23/2022]
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Wang Y, Wong GTC, Man K, Irwin MG. Pretreatment with intrathecal or intravenous morphine attenuates hepatic ischaemia-reperfusion injury in normal and cirrhotic rat liver. Br J Anaesth 2012; 109:529-39. [PMID: 22745352 DOI: 10.1093/bja/aes209] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Opioids have been shown to attenuate ischaemia-reperfusion injury (IRI) in a number of organs. We evaluated the effect of morphine pretreatment on IRI in both normal and cirrhotic rat liver. METHODS Morphine was administered either i.v. or intrathecally (i.t.) 10 min before initiating 1 h of ischaemia followed by 6 h reperfusion in normal rat liver. Hepatic injury was assessed histologically using Suzuki's criteria. These manoeuvres were repeated using the optimal dose of morphine after administration of naloxone methiodide and wortmannin. Serum levels of transaminases were measured, and expression of phosphorylated Akt, Jak2, and STAT3 were assessed by immunoblotting. Similar procedures were repeated on rats with carbon tetrachloride-induced liver cirrhosis, and the levels of phosphorylated protein kinase C (PKC), haem oxygenase-1 (HO-1), and inducible nitric oxide synthase (iNOS) were also evaluated, as these proteins have beneficial effects during IRI. RESULTS Morphine pretreatment at 100 µg kg(-1) (i.v.) or 10 µg (i.t.) reduced necrosis, apoptosis, and serum transaminase levels, and increased phosphorylated Akt and STAT3 but not JAK2 expression in normal liver. These changes were reversed by prior administration of naloxone methiodide and wortmannin. Although morphine preconditioning was also protective in cirrhotic liver, STAT3 and JAK2 phosphorylation status was unchanged. There was, however, increased expression of phosphorylated PKC and HO-1, and a reduction in iNOS. CONCLUSIONS Morphine preconditioning protects against IRI in both normal and cirrhotic rat liver. This involves opioid receptors, phosphatidylinositol-3-kinase, and Akt. The downstream pathways involved are different for cirrhotic liver, with preliminary evidence suggesting involvement of HO-1.
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Affiliation(s)
- Y Wang
- Department of Anaesthesiology, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong
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Kizuka K, Cerviño L, Evans B, Man K, Mushegan S, Park A, Rahimian I, Jiang S. SU-E-T-452: Dynamic Intensity Modulator. Med Phys 2011. [DOI: 10.1118/1.3612406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Cheng Q, Ng KT, Fan ST, Lim ZX, Guo DY, Liu XB, Liu Y, Poon RTP, Lo CM, Man K. Distinct mechanism of small-for-size fatty liver graft injury--Wnt4 signaling activates hepatic stellate cells. Am J Transplant 2010; 10:1178-88. [PMID: 20420630 DOI: 10.1111/j.1600-6143.2010.03102.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In this study, we aimed to investigate the significance of hepatic stellate cells (HSCs) activation in small-for-size fatty liver graft injury and to explore the underlying molecular mechanism in a rat liver transplantation model. A rat orthotopic liver transplantation model using fatty grafts (40% of fatty changes) and cirrhotic recipients was applied. Intragraft gene expression profiles, ultrastructure features and HSCs activation were compared among the rats received different types of grafts (whole vs. small-for-size, normal vs. fatty). The distinct molecular signature of small-for-size fatty graft injury was identified by cDNA microarray screening and confirmed by RT-PCR detection. In vitro functional studies were further conducted to investigate the direct effect of specific molecular signature on HSCs activation. HSCs activation was predominantly present in small-for-size fatty grafts during the first 2 weeks after transplantation, and was strongly correlated with progressive hepatic sinusoidal damage and significant upregulation of intragraft Wnt4 signaling pathway. In vitro suppression of Wnt4 expression could inhibit HSC activation directly. In conclusion, upregulation of Wnt4 signaling led to direct HSC activation and subsequently induced small-for-size fatty liver grafts injury. Discovery of this distinct mechanism may lay the foundation for prophylactic treatment for marginal graft injury in living donor liver transplantation.
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Affiliation(s)
- Q Cheng
- Department of Surgery and Centre for Cancer Research, LKS Faculty of Medicine, the University of Hong Kong, Hong Kong.
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Gao Y, Ng SSM, Chau DHW, Yao H, Yang C, Man K, Huang PT, Huang C, Huang JJ, Kung HF, Lin MC. Development of recombinant adeno-associated virus and adenovirus cocktail system for efficient hTERTC27 polypeptide-mediated cancer gene therapy. Cancer Gene Ther 2008; 15:723-32. [PMID: 18535618 DOI: 10.1038/cgt.2008.33] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The low in vivo transduction efficiency of recombinant adeno-associated virus (rAAV) and the undesirably strong immunogenicity of adenovirus (rAdv) have limited their clinical utilization in cancer gene therapy. We have previously demonstrated that intratumoral injection of rAAV expressing a C-terminal polypeptide of human telomerase reverse transcriptase (rAAV-hTERTC27) effectively inhibits the growth of glioblastoma xenografts in nude mice. To further improve its efficacy, we combined rAAV-hTERTC27 with rAdv and investigated the efficiency of the cocktail vectors in vivo. At a nontherapeutic dose (1 x 10(8) plaque-forming units (PFUs)), rAdv-null and rAdv-hTERTC27 were equipotent in enhancing the therapeutic efficacy of rAAV-hTERTC27 (1.5 x 10(11) v.g.), and complete tumor regression was achieved in 25% of the treated animals. Importantly, the combination of rAAV-hTERTC27 and a therapeutic dose (2.5 x 10(9) PFU) of rAdv-hTERTC27 significantly augmented the therapeutic effects and led to a 38% complete tumor regression rate. In vivo optical imaging also showed that rAAV-luc/rAdv-luc cocktail vectors could synergistically enhance the early transient and latent sustained expression of luciferase, as compared to rAdv-luc and rAAV-luc alone. These findings suggest that the combination of rAAV-hTERTC27 and a therapeutic dose of rAdv-hTERTC27 is potentially a promising treatment for glioblastoma, and the rAAV/rAdv cocktail vector system warrants further development for cancer gene therapy.
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Affiliation(s)
- Y Gao
- Department of Chemistry, Institute of Molecular Biology, The University of Hong Kong, Pokfulam, Hong Kong, China
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Sun CK, Ng KT, Sun BS, Ho JWY, Lee TK, Ng I, Poon RTP, Lo CM, Liu CL, Man K, Fan ST. The significance of proline-rich tyrosine kinase2 (Pyk2) on hepatocellular carcinoma progression and recurrence. Br J Cancer 2007; 97:50-7. [PMID: 17551499 PMCID: PMC2359657 DOI: 10.1038/sj.bjc.6603827] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Understanding the precise molecular mechanisms that trigger liver cancer cell migration and invasion could develop novel therapeutic strategies targeting cancer cell invasion to increase the sensitivity to current treatment modalities. In the current study, 49 patients with hepatocellular carcinoma (HCC) were included prospectively. Liver tumour and adjacent non-tumour tissues were detected for the expression of Proline-rich tyrosine kinase 2 (Pyk2), focal adhesion kinase (FAK), ezrin and fibronectin at protein and/or gene levels. Correlation between the expressions of Pyk2/FAK with the clinical pathological data was analysed. Protein expression of Pyk2 was also examined in a nude mice orthotopic liver tumour model with higher metastatic potential. There were 59% (29 out of 49) and 57% (28 out of 49) of HCC patients with higher levels of Pyk2 and FAK protein/gene expression, respectively. We observed a positive correlation between the protein and gene expression levels of Pyk2 and FAK (P=0.000, r=0.875). Overexpression of Pyk2 and FAK was significantly correlated with shorter disease-free survival. Patients with higher levels of Pyk2/FAK had larger tumour size and advanced Edmonson grading. In the animal studies, Pyk2 overexpression was found in infiltrative tumour cells and lung metastatic nodules. In conclusion, overexpression of Pyk2 and FAK was found in nearly 60% of HCC patients and was significantly correlated with poor prognosis. The significance of Pyk2 in HCC invasiveness was confirmed by animal studies.
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Affiliation(s)
- C K Sun
- Centre of Cancer Research and Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - K T Ng
- Centre of Cancer Research and Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - B S Sun
- Centre of Cancer Research and Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong, China
- Department of Pathology, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - J W Y Ho
- Centre of Cancer Research and Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - T K Lee
- Centre of Cancer Research and Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - I Ng
- Department of Surgery, Yuquan Hospital, Tsinghua University, Beijing, China
| | - R T P Poon
- Centre of Cancer Research and Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - C M Lo
- Centre of Cancer Research and Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - C L Liu
- Centre of Cancer Research and Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - K Man
- Centre of Cancer Research and Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong, China
- E-mail:
| | - S T Fan
- Centre of Cancer Research and Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong, China
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Man K, Ng K, Xu A, Xiao J, Cheng Q, Sun C, Sun B, Poon R, Lo C, Fan S. 59 POSTER Adiponectin as a novel therapy for the suppression of liver cancer growth and metastasis. EJC Suppl 2006. [DOI: 10.1016/s1359-6349(06)70065-9] [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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Man K, Xiao J, Ng K, Cheng Q, Sun B, Wang Y, Sun C, Lo C, Poon R, Fan S. 157 POSTER Combination therapy for liver tumor growth and metastasis by low dose rapamycin and FTY720. EJC Suppl 2006. [DOI: 10.1016/s1359-6349(06)70163-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Sun CKW, Man K, Liu CL, Poon RTP, Fan ST. 391 POSTER The significance of Pyk2 in hepatocellular carcinoma invasiveness. EJC Suppl 2006. [DOI: 10.1016/s1359-6349(06)70396-2] [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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Ng KT, Man K, Sun CK, Lee TK, Poon RT, Lo CM, Fan ST. Clinicopathological significance of homeoprotein Six1 in hepatocellular carcinoma. Br J Cancer 2006; 95:1050-5. [PMID: 17008870 PMCID: PMC2360701 DOI: 10.1038/sj.bjc.6603399] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2006] [Revised: 08/31/2006] [Accepted: 08/31/2006] [Indexed: 01/09/2023] Open
Abstract
Tumour recurrence and metastases of hepatocellular carcinoma (HCC) after hepatectomy are the major obstacles of long-term survival. The present study investigated the clinicopathological significance of a possible metastasis regulator Six1 in HCC patients who were undergone hepatectomy. Seventy-two pairs of RNA and 103 pairs of protein from tumour and adjacent nontumour liver tissues of HCC patients were examined. About 85 and 60% of HCC tumour tissues were found to overexpress Six1 mRNA and protein, respectively, compared with nontumour liver tissues. No Six1 protein was detected in HCC nontumour liver tissues and normal liver tissues. Increased Six1 protein expression in HCC patients was significantly correlated with pathologic tumour-node-metastasis (pTNM) stage (P=0.002), venous infiltration (P=0.004) and poor overall survival (P=0.0423). We concluded that Six1 is frequently overexpressed in HCC patients and elevated Six1 protein in HCC patients may be an indication of advanced stage and poor overall survival after hepatectomy.
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Affiliation(s)
- K T Ng
- Centre for the Study of Liver Disease and Departments of Surgery, The University of Hong Kong, Queen Mary Hospital, L9-55, Faculty of Medicine Building, 21 Sassoon Road, Pokfulam, Hong Kong, China
| | - K Man
- Centre for the Study of Liver Disease and Departments of Surgery, The University of Hong Kong, Queen Mary Hospital, L9-55, Faculty of Medicine Building, 21 Sassoon Road, Pokfulam, Hong Kong, China
| | - C K Sun
- Centre for the Study of Liver Disease and Departments of Surgery, The University of Hong Kong, Queen Mary Hospital, L9-55, Faculty of Medicine Building, 21 Sassoon Road, Pokfulam, Hong Kong, China
| | - T K Lee
- Centre for the Study of Liver Disease and Departments of Surgery, The University of Hong Kong, Queen Mary Hospital, L9-55, Faculty of Medicine Building, 21 Sassoon Road, Pokfulam, Hong Kong, China
| | - R T Poon
- Centre for the Study of Liver Disease and Departments of Surgery, The University of Hong Kong, Queen Mary Hospital, L9-55, Faculty of Medicine Building, 21 Sassoon Road, Pokfulam, Hong Kong, China
| | - C-M Lo
- Centre for the Study of Liver Disease and Departments of Surgery, The University of Hong Kong, Queen Mary Hospital, L9-55, Faculty of Medicine Building, 21 Sassoon Road, Pokfulam, Hong Kong, China
| | - S-T Fan
- Centre for the Study of Liver Disease and Departments of Surgery, The University of Hong Kong, Queen Mary Hospital, L9-55, Faculty of Medicine Building, 21 Sassoon Road, Pokfulam, Hong Kong, China
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Abstract
The phospho-Ser/Thr-Pro specific prolyl-isomerase PIN1 is over-expressed in more than 50% of hepatocellular carcinomas (HCCs). To investigate its potential oncogenicity, we over-expressed PIN1 in a non-transformed human liver cell line MIHA. This resulted in up-regulation of beta-catenin and cyclin D1, leading to anchorage-independent growth in soft agar and tumorigenicity in nude mice. To further validate the role of PIN1 in hepatocarcinogenesis, PIN was suppressed by RNA interference (siRNA) in the HCC cell line PLC/PRF/5. siRNA-PIN1 transfection of PLC/PRF/5 cells led to repression of PIN1 expression, resulting in decreased levels of beta-catenin and cyclin D1. siRNA-PIN1 transfectants showed lower cell proliferation rates, reduced colony formation, and retarded cell cycle progression, with an increase in cells residing in G0/G1. Furthermore, soft agar colony formation was depressed, and tumorigenicity in nude mice was abrogated. These findings implicate PIN1 expression as an important step in hepatic carcinogenesis.
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Affiliation(s)
- R W Pang
- Department of Medicine, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong
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Man K, Su M, Ng KT, Lo CM, Zhao Y, Ho JW, Sun CK, Lee TK, Fan ST. Rapamycin attenuates liver graft injury in cirrhotic recipient--the significance of down-regulation of Rho-ROCK-VEGF pathway. Am J Transplant 2006; 6:697-704. [PMID: 16539626 DOI: 10.1111/j.1600-6143.2005.01231.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
To investigate whether rapamycin could attenuate hepatic I/R injury in a cirrhotic rat liver transplantation model, we applied a rat orthotopic liver transplantation model using 100% or 50% of liver grafts and cirrhotic recipients. Rapamycin was given (0.2 mg/kg, i.v.) at 30 min before graft harvesting in the donor and 24 h before operation, 30 min before total hepatectomy and immediately after reperfusion in the recipient. Rapamycin significantly improved small-for-size graft survival from 8.3% (1/12) to 66.7% (8/12) (p = 0.027). It also increased 7-day survival rates of whole grafts (58.3%[7/12] vs. 83.3%[10/12], p = 0.371). Activation of hepatic stellate cells was mainly found in small-for-size grafts during the first 7 days after liver transplantation. Rapamycin suppressed expression of smooth muscle actin, which is a marker of hepatic stellate cell activation, especially in small-for-size grafts. Intragraft protein expression and mRNA levels of vascular endothelial growth factor (VEGF) were down-regulated by rapamycin at 48 h both in whole and small-for-size grafts. Consistently, mRNA levels and protein expression of Rho and ROCK I were decreased by rapamycin during the 48 h after liver transplantation. In conclusion, rapamycin attenuated graft injury in a cirrhotic rat liver transplantation model by suppression of hepatic stellate cell activation, related to down-regulation of Rho-ROCK-VEGF pathway.
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Affiliation(s)
- K Man
- Centre for the Study of Liver Disease and Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong.
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Man K, Zhao Y, Xu A, Lo CM, Lam KSL, Ng KT, Ho JWY, Sun CK, Lee TK, Li XL, Fan ST. Fat-derived hormone adiponectin combined with FTY720 significantly improves small-for-size fatty liver graft survival. Am J Transplant 2006; 6:467-76. [PMID: 16468955 DOI: 10.1111/j.1600-6143.2005.01201.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [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: 01/25/2023]
Abstract
Owing to the discrepancy between organ donation and the demand for liver transplantation, expanding the liver donor pool is of vital importance. However, marginal liver grafts, such as small-for-size and/or fatty grafts, were associated with primary graft nonfunction or poor function. Therefore, novel combination therapies to rescue small-for-size fatty liver grafts should be investigated. In this study, we applied a combination therapy using a fat-derived hormone adiponectin (anti-steatosis) plus immunomodulator FTY720 (anti-inflammatory) in a rat liver transplantation model using small-for-size fatty liver grafts, and investigated the underlying protective mechanism such as anti-steatosis, intra-graft energy metabolism, hepatic microcirculatory changes, cell signaling cascades for survival, apoptosis and inflammation. The current study demonstrated that even a single treatment of adiponectin or FTY720 improved the 7-day graft survival from 0% to 62.5% (p = 0.001). The combination therapy significantly increased the 7-day graft survival rate to 100% by remarkable attenuation of graft steatosis and acute phase inflammatory response, significant activation of cell survival Akt pathway and maintenance of intra-graft adenosine triphosphate metabolism and improvement of hepatic microcirculation. In conclusion, the fat-derived hormone adiponectin combined with FTY720 might be a novel combination drug therapy for prevention of small-for-size fatty liver graft injury.
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Affiliation(s)
- K Man
- Centre for the Study of Liver Disease and Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong, China.
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Man K, Kareem AMM, Ahmad Alias NA, Shuaib IL, Tharakan J, Abdullah JM, Prasad A, Hussin AM, Naing NN. Computed tomography perfusion of ischaemic stroke patients in a rural Malaysian tertiary referral centre. Singapore Med J 2006; 47:194-7. [PMID: 16518552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
INTRODUCTION Computed tomography (CT) perfusion is a new method to diagnose ischaemic stroke especially in developing countries. It identifies the area and is useful to predict the size of final infarction. The aim of this study was to assess cerebral ischaemia with CT perfusion (CTP) among patients with acute ischaemic stroke in Hospital Universiti Sains Malaysia, a tertiary referral centre in a rural setting. METHODS 42 consecutive unenhanced CT and CTP examinations of the brain in adult patients were evaluated prospectively. Unenhanced CT images were divided into normal, suspicious or frank infarction. CTP images was classified as normal or ischaemic. Subgroup analysis was carried out with a limit of six hours from time of ictus. RESULTS Out of 42 patients, 20 had frank infarction on unenhanced CT, 15 had suspicious CT studies, while seven were normal. There was no significant association of demographical, clinical and radiological parameters to CTP in the whole group among acute stroke patients without frank infarction. Among the subgroup of patients without frank infarction, there was no significant association between unenhanced CT and CTP in patients who were studied less than six hours after stroke (p-value is 0.063) as well as those after six hours (p-value is 0.317). The prevalence of a normal unenhanced CT and positive CTP for ischaemia was 22.7 percent (95 percent confidence interval 7.8, 45.4). CONCLUSION CTP may be a useful imaging tool for determining cerebral infarction in a rural-based community population, especially in cases where the unenhanced CT is normal. Thrombolysis is a therapeutic option, even when the history of onset of stroke is unclear.
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Affiliation(s)
- K Man
- Department of Radiology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
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Man K, Lo CM, Liu CL, Zhang ZW, Lee TKW, Ng IOL, Fan ST, Wong J. Effects of the intermittent Pringle manoeuvre on hepatic gene expression and ultrastructure in a randomized clinical study. Br J Surg 2003; 90:183-9. [PMID: 12555294 DOI: 10.1002/bjs.4027] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND The intermittent Pringle manoeuvre during hepatectomy results in a better clinical outcome when the accumulated ischaemia time is less than 120 min. The aim of this study was to investigate hepatic gene expression related to microcirculatory modulation and ultrastructural changes in patients having the intermittent Pringle manoeuvre. METHODS Forty patients who underwent hepatectomy for liver tumours were randomly assigned to liver transection with intermittent Pringle manoeuvre (Pringle group, n = 20) or without the manoeuvre (control group, n = 20). The clinical data and hepatic expression of endothelin (ET) 1 and endothelial nitric oxide synthase (eNOS) combined with liver ultrastructure were compared. RESULTS The Pringle manoeuvre resulted in less blood loss (8.9 versus 12.4 ml/cm(2); P = 0.034), a shorter transection time (2.7 versus 4.1 min/cm(2); P = 0.015) and a lower serum bilirubin level on postoperative day 2 (26 versus 35 microm/l; P = 0.04). The hepatic messenger RNA content of ET-1 decreased by 38 per cent of the basal level in the Pringle group, whereas it increased by 28 per cent in the control group (P = 0.026). More patients in the control group showed swelling of mitochondria in hepatocytes and disruption of sinusoidal lining cells (12 of 20 patients versus three of 20 in the Pringle group; P = 0.008). CONCLUSION The intermittent Pringle manoeuvre results in less disturbance of the hepatic microcirculation and better preservation of liver sinusoids after hepatectomy.
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Affiliation(s)
- K Man
- Department of Surgery, Centre for the Study of Liver Disease, University of Hong Kong Medical Centre, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong, China
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Man K, Lo CM, Ng IO, Wong YC, Qin LF, Fan ST, Wong J. Liver transplantation in rats using small-for-size grafts: a study of hemodynamic and morphological changes. Arch Surg 2001; 136:280-5. [PMID: 11231846 DOI: 10.1001/archsurg.136.3.280] [Citation(s) in RCA: 160] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Damage to a small-for-size liver graft after reperfusion is frequently observed but the mechanism of injury remains unclear. HYPOTHESIS Injury to a small-for-size liver graft is related to the changes of portal pressure and blood flow. MAIN OUTCOME MEASURES Survival rates, portal hemodynamics, microcirculatory changes, and morphological changes (by light microscopy and electron microscopy). SETTING A rat model of nonarterialized orthotopic liver transplantation comparing 2 groups of rats transplanted with whole grafts (100% of recipient liver weight) and small-for-size grafts (30% of recipient liver weight). RESULTS Median survival of the rats with small-for-size grafts was 30 hours (range, 27-37 hours). During the first 15 minutes after reperfusion, mean arterial pressure of the small-for-size graft group was significantly lower than that of the whole graft group (10-minute: 100 vs 132 mm Hg, P =.04; 15-minute: 96 vs 127 mm Hg, P =.04). Portal pressure (in centimeters of water) of the small-for-size graft group was significantly higher in the first 20 minutes after reperfusion than the level before the anhepatic phase (5-minute: 15.1 vs 9.3, P =.02; 10-minute: 16.1 vs 9.3, P =.03; 15-minute, 13.5 vs 9.3, P =.03; 20-minute: 13.4 vs 9.3, P =.03) and was significantly higher than that of the whole graft group in the first 10 minutes after reperfusion (5-minute: 15.1 vs 9.6, P =.02; 10-minute: 16.1 vs 10.3, P =.04). Hepatic microcirculatory blood flow (in milliliters per minute per 100 g) was also significantly higher in the small-for-size graft group during the first 40 minutes after reperfusion (5-minute: 16.3 vs 9.3, P =.02; 10-minute: 14.9 vs 6.6, P =.02; 15-minute: 14.8 vs 5.5, P =.02; 20-minute: 13.1 vs 7.0, P =.02; 30-minute: 13.2 vs 8.8, P =.04; 40-minute: 14.6 vs 7.1, P =.02). Light and electron microscopy showed normal morphological features of whole graft up to 24 hours after reperfusion. The small-for-size graft, however, showed sinusoidal congestion, tremendous swelling of mitochondria of hepatocytes, irregular large gap of sinusoidal lining cells, and collapse of the space of Disse. CONCLUSIONS In a rat model, the portal hemodynamic changes in small-for-size grafts are transient. Progressive damage of the graft may result from microcirculatory failure due to irreversible endothelial injury after reperfusion.
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Affiliation(s)
- K Man
- Department of Surgery, The University of Hong Kong Medical Centre, Queen Mary Hospital, 102 Pokfulam Rd, Hong Kong, China
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Liu D, Hk N, Man K, Luo X, Yang L, Sun Z. [Pathomorphological and amyloid beta-protein immunohistochemical findings in autopsied brains of Alzheimer's disease]. Zhonghua Bing Li Xue Za Zhi 1999; 28:405-8. [PMID: 11869551] [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: 02/23/2023]
Abstract
OBJECTIVE To study the incidence and neuropathological features of Alzheimer's disease in Chinese and the significance of silver and amyloid beta-protein staining for the pathological diagnosis of Alzheimer's disease. METHODS Among 445 autopsy cases above 60 years in age (including 60) collected from 1982-1998 in the Department of Pathology, Beijing Hospital, totally 29 cases were diagnosed as Alzheimer's disease pathologically (6.5%), accompanying with a history of mental deterioration and the histological changes in certain areas of the brain fulfilling the Khachaturian or Mirra criteria. Tissue blocks were taken from 6 standard regions of the brains for Bodian, Bielschowsky and amyloid beta-protein immunostaining. Senile plaques and neurofibrillary tangles were quantified. RESULTS Four main types of senile plaques were noticed and the result by amyloid beta-protein immunostaining was considered more sensitive than that of the silver impregnation staining. The former one enabled to demonstrate all the 4 types of senile plaques, while silver impregnation staining could only demonstrate clearly the primitive and neuritic plaques, but not the small diffuse and burn-out plaques. The senile plaques were noticed to be focused in the hippocampus, superior temporal gyrus and middle frontal gyrus while the neurofibrillary tangles, were mainly obtained in the hippocampus, temporal cortex and amygdaloid. Cerebral amyloid angiopathy was found in 25 out of 29 Alzheimer's disease cases. CONCLUSIONS Alzheimer's disease may be the main cause of dementia among the elders in Chinese and immunostaining for amyloid beta-protein pretreated with formic acid may set a high value on the pathological diagnosis of Alzheimer's disease.
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Affiliation(s)
- D Liu
- Department of Pathology, Beijing Hospital, Beijing 100730
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Fahrner WR, Grabosch G, Borchert D, Man K, Chan Y, Kwong S. Temperature dependency of the intrinsic carrier density of hydrogenated amorphous silicon in MOS structures. J Solid State Electrochem 1999. [DOI: 10.1007/s100080050154] [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: 11/28/2022]
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Liu D, You G, Wei J, Sun Z, Man K. [A clinico-pathological and etiological study of Binswanger's Disease]. Zhonghua Bing Li Xue Za Zhi 1999; 28:174-7. [PMID: 11869523] [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: 02/23/2023]
Abstract
OBJECTIVE To study the pathology, incidence and etiology of Binswanger's disease. METHODS Autopsied brains from 9 cases of Binswanger's disease and 13 cases of non-demented elderly individuals were studied by clinico-pathological, immunohistochemical and micrometer methods. RESULTS The lesions of Binswanger's disease were mainly located in the subcortical white matter, periventrical regions, brainstem and cerebellum. The pathological changes were demyelination, lacunar infarction, gliosis and dilatation of perivascular space (Virchow-Robin space, VR space, P < 0.01). The wall thickness of deeply penetrating arteries in the white matter was significantly increased (P < 0.01). CONCLUSION Binswanger's disease is not a rare entity. The findings of this study suggest that arteriosclerosis is a primary factor in the pathogenesis of Binswanger's disease.
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Affiliation(s)
- D Liu
- Department of Pathology, Beijing Hospital, Beijing 100730
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Man K, Fan ST, Ng IO, Lo CM, Liu CL, Yu WC, Wong J. Tolerance of the liver to intermittent pringle maneuver in hepatectomy for liver tumors. Arch Surg 1999; 134:533-9. [PMID: 10323426 DOI: 10.1001/archsurg.134.5.533] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Hepatectomy can be performed with a low mortality rate, but massive hemorrhage during the operation remains a potentially lethal problem. The Pringle maneuver is traditionally used during hepatectomy to reduce blood loss, but the effect on the metabolic function of hepatocytes is potentially harmful. Although our randomized study showed that an intermittent Pringle maneuver is safe and effective during hepatectomy, the upper limit of the duration of the Pringle maneuver is not known. HYPOTHESIS The liver can tolerate intermittent Pringle maneuver if the duration is not excessive. DESIGN From July 20, 1995, to November 25, 1997, 112 patients underwent hepatectomy for liver tumors. The data of 50 patients who had hepatectomy without the Pringle maneuver were compared with those of 62 patients who had a liver transection using a Pringle maneuver for 20 minutes and a 5-minute clamp-free interval. The data were collected prospectively. MAIN OUTCOME MEASURES The surface area of liver transection was measured, and blood loss during liver transection per centimeter square of transection area was calculated. Routine liver biochemical tests, arterial ketone body ratio (AKBR), and plasma cytokine-interleukin (IL) 1alpha, 1beta, 2, and 6, and tumor necrosis factor alpha--levels were measured before and after the operation. The morbidity and hospital mortality rates were also compared among the patients with different ischemic durations and those without an intermittent Pringle maneuver. SETTING Tertiary referral center. RESULTS The cutoff point of accumulated ischemic time that induced substantial liver damage, as shown by the postoperative recovery rate of the AKBR, was found to be 120 minutes. Compared with the control group, the patients whose accumulated ischemic time was shorter than 120 minutes had less blood loss related to transection area (10 mL/cm2 vs 22 mL/cm2; P<.001), less blood transfused (0 L vs 0.6 L; P = .004), a shorter transection time related to transection area (2.0 min/cm2 vs 2.8 min/ cm2; P = .002), a significantly higher AKBR in the first 2 hours after liver transection, an equal recovery rate of the AKBR, and a comparable increase of the plasma level of IL-6 postoperatively. For the patients whose accumulated ischemic time was longer than 120 minutes, blood loss from the transection area was less than for the control group (14 mL/cm2 vs 22 mL/cm2; P<.05), but the transection time related to the transection area and the blood transfusion volume did not differ from those of the control group. Furthermore, they had a significantly lower recovery rate of the AKBR and higher plasma levels of IL-6 postoperatively than the control group.
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Affiliation(s)
- K Man
- Department of Surgery, The University of Hong Kong, Queen Mary Hospital, China
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Abstract
OBJECTIVE To evaluate whether vascular inflow occlusion by the Pringle maneuver during hepatectomy can be safe and effective in reducing blood loss. SUMMARY BACKGROUND DATA Hepatectomy can be performed with a low mortality rate, but massive hemorrhage during surgery remains a potentially lethal problem. The Pringle maneuver is traditionally used during hepatectomy to reduce blood loss, but there is a potential harmful effect on the metabolic function of hepatocytes. There has been no prospective randomized study to determine whether the Pringle maneuver can decrease blood loss during hepatectomy, improve outcome, or affect the metabolism of hepatocytes. METHODS From July 1995 to February 1997, we studied 100 consecutive patients who underwent hepatectomy for liver tumors. The patients were randomly assigned to liver transection under intermittent Pringle maneuver of 20 minutes and a 5-minute clamp-free interval (n = 50), or liver transection without the Pringle maneuver (n = 50). The surface area of liver transection was measured and blood loss during transection per square centimeter of transection area was calculated. Routine liver biochemistry, arterial ketone body ratio (AKBR), and the indocyanine green (ICG) clearance test were done. RESULTS The two groups were comparable in terms of preoperative liver function and in the proportion of patients having major hepatectomy. The Pringle maneuver resulted in less blood loss per square centimeter of transection area (12 mL/cm2 vs. 22 mL/cm2, p = 0.0001), a shorter transection time per square centimeter of transection area (2 min/cm2 vs. 2.8 min/cm2, p = 0.016), a significantly higher AKBR in the first 2 hours after hepatectomy, lower serum bilirubin levels in the early postoperative period, and, in cirrhotic patients, higher serum transferrin levels on postoperative days 1 and 8. The complication rate, the hospital mortality rate, and the ICG retention at 15 minutes on postoperative day 8 were equal for the two groups. CONCLUSION Performing the Pringle maneuver during liver transection resulted in less blood loss and better preservation of liver function in the early postoperative period. This is probably because there was less hemodynamic disturbance induced by the bleeding.
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Affiliation(s)
- K Man
- Department of Surgery, The University of Hong Kong, Queen Mary Hospital, Hong Kong
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Abstract
BACKGROUND Postoperative hepatic failure is the leading cause of hospital mortality following hepatectomy for hepatocellular carcinoma (HCC). This prospective study was performed to identify the best test for assessment of the adequacy of hepatic functional reserve in patients with HCC before hepatectomy. METHODS Between April 1989 and June 1993, 127 patients with HCC underwent hepatectomy. Each patient was evaluated before operation with the indocyanine green (ICG) clearance test, the aminopyrine breath test and the amino acid clearance test. RESULTS Fourteen patients (11 per cent) died after hepatectomy. ICG retention at 15 min showed significant differences between patients who survived or died. By discriminant analysis, the safety limit of ICG retention at 15 min for major hepatectomy was 14 per cent and the relative risk of hospital mortality was 3. CONCLUSION The ICG clearance test, expressed as the percentage of ICG retained at 15 min, is the best discriminating preoperative test for evaluating hepatic functional reserve in patients with HCC before hepatectomy.
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Affiliation(s)
- H Lau
- Department of Surgery, University of Hong Kong, Queen Mary Hospital, Hong Kong
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Lau H, Man K, Fan ST, Yu WC, Lo CM, Wong J. Evaluation of preoperative hepatic function in patients with hepatocellular carcinoma undergoing hepatectomy. Br J Surg 1997. [PMID: 9313707 DOI: 10.1002/bjs.1800840917] [Citation(s) in RCA: 196] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Postoperative hepatic failure is the leading cause of hospital mortality following hepatectomy for hepatocellular carcinoma (HCC). This prospective study was performed to identify the best test for assessment of the adequacy of hepatic functional reserve in patients with HCC before hepatectomy. METHODS Between April 1989 and June 1993, 127 patients with HCC underwent hepatectomy. Each patient was evaluated before operation with the indocyanine green (ICG) clearance test, the aminopyrine breath test and the amino acid clearance test. RESULTS Fourteen patients (11 per cent) died after hepatectomy. ICG retention at 15 min showed significant differences between patients who survived or died. By discriminant analysis, the safety limit of ICG retention at 15 min for major hepatectomy was 14 per cent and the relative risk of hospital mortality was 3. CONCLUSION The ICG clearance test, expressed as the percentage of ICG retained at 15 min, is the best discriminating preoperative test for evaluating hepatic functional reserve in patients with HCC before hepatectomy.
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Affiliation(s)
- H Lau
- Department of Surgery, University of Hong Kong, Queen Mary Hospital, Hong Kong
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Fan ST, Lo CM, Man K. [Liver transplantation report of 23 cases]. Zhonghua Yi Xue Za Zhi 1996; 76:267-70. [PMID: 8758271] [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: 02/02/2023]
Abstract
OBJECTIVE To explore the experience of liver transplantation in patients with terminal liver failure. METHOD From October 1991 to July 1995, 17 adults and 6 children underwent orthotopic liver transplantation. Preoperative diagnosis showed biliary atresia (n = 5), Alagille syndrome (n = 1), primary biliary cirrhosis (n = 2), cryptogenic cirrhosis (n = 2), alcoholic cirrhosis (n = 4), Wilson's disease (n = 1), fulminant hepatic failure (n = 3), polycystic liver (n = 2), secondary biliary cirrhosis (n = 1), hepatitis B cirrhosis (n = 1), and autoimmune hepatitis associated with a small hepatocellular carcinoma (n = 1). One paediatric patient suffered from hepatitis of unknown aetiology which progressed to liver failure after liver transplantation. She received retransplantation using a living graft from her mother. The liver grafts were obtained from 17 brainstem dead donors and 7 living donors. RESULTS The overall patient survival rate was 92% and graft survival rate was 88%. There were only 2 deaths, one was due to primary graft nonfunction and the other was due to persistent graft rejection not responding to pulse steroid and OKT3. The other patients are alive and well. CONCLUSIONS Liver transplantation is a feasible and viable treatment for patients with terminal liver failure in Hong Kong. The only limitation is lack of brainstem dead donor. Promotion of concept of brainstem death and organ donation in the society is the key to wide use of liver transplantation for patients with terminal liver failure in Asia.
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Affiliation(s)
- S T Fan
- Department of Surgery, Queen Mary Hospital, Hong Kong
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Farrell FJ, Nguyen M, Woodley S, Imperial JC, Garcia-Kennedy R, Man K, Esquivel CO, Keeffe EB. Outcome of liver transplantation in patients with hemochromatosis. Hepatology 1994; 20:404-10. [PMID: 8045502] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Recent preliminary reports suggest a poor outcome of orthotopic liver transplantation for patients with hemochromatosis. We analyzed an institutional experience with orthotopic liver transplantation for hemochromatosis, focusing on factors contributing to increased morbidity and mortality. Between March 1988 and October 1992, nine of 249 adults (3.6%) undergoing orthotopic liver transplantation had hemochromatosis. Mean age was 53 yr (range, 42 to 62 yr), and eight of nine patients were men. The diagnosis of hemochromatosis was based on transferrin saturation > 62% and hepatic iron index > 2.0. Only two patients were known to have hemochromatosis before liver transplantation. All nine patients underwent standard cardiac evaluation before transplantation, and no patient had detectable pre-existing cardiac disease. One patient had a major operative cardiac complication as a result of pulmonary embolism and made a full recovery. Postoperatively, congestive heart failure developed in three patients and four patients had arrhythmias. One patient is undergoing phlebotomy for post-transplant cardiac complications from hemochromatosis. Two patients had primary hepatic tumors in the explant liver. There were four deaths caused by multiorgan failure with congestive heart failure (1), infection (2), and/or malignancy (2). Five patients are alive 3 to 25 mo post-transplant. The actuarial survival of the nine patients was 53% at 25 mo vs. 89% for 18 age- and sex-matched control transplant recipients (p = 0.1) and 81% for all other adult liver transplant recipients (p < 0.01). In five of seven patients, post-transplant liver biopsies revealed hepatic iron accumulation.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- F J Farrell
- Department of Medicine, California Pacific Medical Center, San Francisco 94115
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Abstract
Nine patients presenting with dysphagia following successful treatment for head and neck cancer with neutron radiotherapy are reviewed. Combined clinical and videofluoroscopic investigation is used to analyse their deficits and provide indications for management. All patients show impairment of both the oral and pharyngeal phases of the swallow, with the exception of one subject who shows signs of focal neurological damage. It is suggested that fibrosis is the underlying cause of dysphagia in the remainder.
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Affiliation(s)
- M S Alexander
- Department of Diagnostic Radiology, Royal Postgraduate Medical School, Hammersmith Hospital, London
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Lian-Niang L, Xiang-Jun Q, Da-Lun G, Man K. Neokadsuranin, a Tetrahydrofuranoid Dibenzocyclooctadiene Lignan from Stems of Kadsura coccinea. Planta Med 1988; 54:45-6. [PMID: 17265201 DOI: 10.1055/s-2006-962331] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
A tetrahydrofuranoid dibenzocyclooctadiene lignan, which we name neokadsuranin, was isolated from the stems of Kadsura coccinea, collected in Kuangxi, China. The absolute configuration was elucidated by spectral analysis.
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Affiliation(s)
- L Lian-Niang
- Institute of Materia Medica, Chinese Academy of Medical Sciences, 1 Xian Nong Tan Street, Beijing, Peoples' Republic of China
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