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Ding P, Braim M, Hobson AL, Rochford LA, Ryan PTP, Duncan DA, Lee TL, Hussain H, Costantini G, Yu M, Woodruff DP. Does F 4TCNQ Adsorption on Cu(111) Form a 2D-MOF? J Phys Chem C Nanomater Interfaces 2023; 127:20903-20910. [PMID: 37908743 PMCID: PMC10614301 DOI: 10.1021/acs.jpcc.3c04927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 09/21/2023] [Indexed: 11/02/2023]
Abstract
The results of a quantitative experimental structural investigation of the adsorption phases formed by 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinodimethane (F4TCNQ) on Cu(111) are reported. A particular objective was to establish whether Cu adatoms are incorporated into the molecular overlayer. A combination of normal incidence X-ray standing waves, low-energy electron diffraction, scanning tunneling microscopy, and X-ray photoelectron spectroscopy measurements, complemented by dispersion-inclusive density functional theory calculations, demonstrates that F4TCNQ on Cu(111) does cause Cu adatoms to be incorporated into the overlayer to form a two-dimensional metal-organic framework (2D-MOF). This conclusion is shown to be consistent with the behavior of F4TCNQ adsorption on other coinage metal surfaces, despite an earlier report concluding that the adsorption structure on Cu(111) is consistent with the absence of any substrate reconstruction.
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Affiliation(s)
- Pengcheng Ding
- Department
of Physics, University of Warwick, Coventry CV4 7AL, U.K.
- Laboratory
for Space Environment and Physical Sciences, School of Chemistry and
Chemical Engineering, Harbin Institute of
Technology, Harbin 150001, China
| | - Mona Braim
- Department
of Physics, University of Warwick, Coventry CV4 7AL, U.K.
| | - A. L. Hobson
- Department
of Physics, University of Warwick, Coventry CV4 7AL, U.K.
- Diamond
Light Source, Harwell Science and Innovation
Campus, Didcot, Oxford OX11 0DE, U.K.
| | - L. A. Rochford
- Diamond
Light Source, Harwell Science and Innovation
Campus, Didcot, Oxford OX11 0DE, U.K.
| | - P. T. P. Ryan
- Diamond
Light Source, Harwell Science and Innovation
Campus, Didcot, Oxford OX11 0DE, U.K.
- Department
of Materials, Imperial College London, London SW7 2AZ, U.K.
| | - D. A. Duncan
- Diamond
Light Source, Harwell Science and Innovation
Campus, Didcot, Oxford OX11 0DE, U.K.
| | - T.-L. Lee
- Diamond
Light Source, Harwell Science and Innovation
Campus, Didcot, Oxford OX11 0DE, U.K.
| | - H. Hussain
- Diamond
Light Source, Harwell Science and Innovation
Campus, Didcot, Oxford OX11 0DE, U.K.
| | - G. Costantini
- Department
of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
- School of
Chemistry, University of Birmingham, Birmingham B15 2TT, U.K.
| | - Miao Yu
- Laboratory
for Space Environment and Physical Sciences, School of Chemistry and
Chemical Engineering, Harbin Institute of
Technology, Harbin 150001, China
| | - D. P. Woodruff
- Department
of Physics, University of Warwick, Coventry CV4 7AL, U.K.
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Sohail B, Blowey PJ, Rochford LA, Ryan PTP, Duncan DA, Lee TL, Starrs P, Costantini G, Woodruff DP, Maurer RJ. Donor-Acceptor Co-Adsorption Ratio Controls the Structure and Electronic Properties of Two-Dimensional Alkali-Organic Networks on Ag(100). J Phys Chem C Nanomater Interfaces 2023; 127:2716-2727. [PMID: 36798903 PMCID: PMC9923740 DOI: 10.1021/acs.jpcc.2c08688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/12/2023] [Indexed: 06/18/2023]
Abstract
The results are presented of a detailed combined experimental and theoretical investigation of the influence of coadsorbed electron-donating alkali atoms and the prototypical electron acceptor molecule 7,7,8,8-tetracyanoquinodimethane (TCNQ) on the Ag(100) surface. Several coadsorption phases were characterized by scanning tunneling microscopy, low-energy electron diffraction, and soft X-ray photoelectron spectroscopy. Quantitative structural data were obtained using normal-incidence X-ray standing wave (NIXSW) measurements and compared with the results of density functional theory (DFT) calculations using several different methods of dispersion correction. Generally, good agreement between theory and experiment was achieved for the quantitative structures, albeit with the prediction of the alkali atom heights being challenging for some methods. The adsorption structures depend sensitively on the interplay of molecule-metal charge transfer and long-range dispersion forces, which are controlled by the composition ratio between alkali atoms and TCNQ. The large difference in atomic size between K and Cs has negligible effects on stability, whereas increasing the ratio of K/TCNQ from 1:4 to 1:1 leads to a weakening of molecule-metal interaction strength in favor of stronger ionic bonds within the two-dimensional alkali-organic network. A strong dependence of the work function on the alkali donor-TCNQ acceptor coadsorption ratio is predicted.
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Affiliation(s)
- B. Sohail
- Department
of Chemistry, University of Warwick, CoventryCV4 7AL, U.K.
| | - P. J. Blowey
- Department
of Physics, University of Warwick, CoventryCV4 7AL, U.K.
- Diamond
Light Source, Harwell Science and Innovation Campus, DidcotOX11 0DE, U.K.
| | - L. A. Rochford
- School
of Chemistry, University of Birmingham, BirminghamB15 2TT, U.K.
| | - P. T. P. Ryan
- Diamond
Light Source, Harwell Science and Innovation Campus, DidcotOX11 0DE, U.K.
- Department
of Materials, Imperial College, London, LondonSW7 2AZ, U.K.
| | - D. A. Duncan
- Diamond
Light Source, Harwell Science and Innovation Campus, DidcotOX11 0DE, U.K.
| | - T.-L. Lee
- Diamond
Light Source, Harwell Science and Innovation Campus, DidcotOX11 0DE, U.K.
| | - P. Starrs
- Diamond
Light Source, Harwell Science and Innovation Campus, DidcotOX11 0DE, U.K.
- School of
Chemistry, University of St. Andrews, St. AndrewsKY16 9AJ, U.K.
| | - G. Costantini
- Department
of Physics, University of Warwick, CoventryCV4 7AL, U.K.
- School
of Chemistry, University of Birmingham, BirminghamB15 2TT, U.K.
| | - D. P. Woodruff
- Department
of Physics, University of Warwick, CoventryCV4 7AL, U.K.
| | - R. J. Maurer
- Department
of Chemistry, University of Warwick, CoventryCV4 7AL, U.K.
- Department
of Physics, University of Warwick, CoventryCV4 7AL, U.K.
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Lee WT, Ng KW, Liao J, Luk ACS, Suen HC, Chan THT, Cheung MY, Chu D, Zhao M, Chan YL, Li TC, Lee TL. P–547 Single-cell RNA sequencing identifies molecular regulations associated with poor maturation performance on rescue in vitro matured oocytes. Hum Reprod 2021. [DOI: 10.1093/humrep/deab130.546] [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: 11/12/2022] Open
Abstract
Abstract
Study question
What is the transcriptome signature associated with rescuein vitro matured (rIVM) oocytes?
Summary answer
GATA–1/CREB1/WNT signaling axis was repressed in rIVM oocytes of poor quality.
What is known already
rIVM aims to produce mature oocytes (MII) for in vitro fertilization (IVF) through IVM of immature oocytes collected from stimulated ovaries. It is less popular due to limited success rate in infertility treatment. Genetic aberrations, cellular stress, and the absence of cumulus cell support in oocytes could account for the failure of rIVM.
Study design, size, duration
We applied single-cell RNA sequencing (scRNA-seq) to capture the transcriptomes of human in vivo (IVO) oocytes (n = 10) from 7 donors and rIVM oocytes (n = 10) from 10 donors, followed by studying the maternal age effect and ovarian responses on rIVM oocyte transcriptomes.
Participants/materials, setting, methods
Human oocytes were collected from donors aged 28–41 years with a body mass index of < 30. RNA extraction, cDNA generation, library construction and sequencing were performed in one preparation. scRNA-seq data were then processed and analyzed. Selected genes in therIVM vs. IVO comparison were validated by quantitative real-time PCR.
Main results and the role of chance
The transcriptome profiles of rIVM/IVO showed distinctive differences. A total of 1559 differentially expressed genes (DEGs, genes with at least two-fold change and adjusted p < 0.05) were found to be enriched in metabolic processes, biosynthesis, and oxidative phosphorylation. Among these DEGs, we identified a repression of WNT/β-catenin signaling in rIVM when compared with IVO oocytes. We found that estradiol level exhibited a significant age-independent correlation with the IVO mature oocyte ratio (MII ratio). rIVM oocytes with higher MII ratio showed over-represented cellular processes such as anti-apoptosis. To further identify targets that contribute to the poor outcomes of rIVM, we compared oocytes collected from young donors with high MII ratio versus donors of advanced maternal age and revealed CREB1was an important regulator in rIVM. Our study identified GATA–1/CREB1/WNT signaling was repressed in both rIVM condition and rIVM oocytes of low-quality.
Limitations, reasons for caution
In the rIVM oocytes of high- and low-quality comparison, the number of samples was limited after data filtering with stringent selection criteria. For the oocyte stage identification, we were unable to predict the presence of oocyte spindle so polar body extrusion was the only indicator.
Wider implications of the findings: This study showed that GATA–1/CREB1/WNT signaling and antioxidant actions were repressed in rIVM condition and was further downregulated in rIVM oocytes of low-quality, providing us the foundation of subsequent follow-up research on human subjects.
Trial registration number
Not applicable
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Affiliation(s)
- W T Lee
- The Chinese University of Hong Kong, School of Biomedical Sciences, Hong Kong, Hong Kong
| | - K W Ng
- The Chinese University of Hong Kong, School of Biomedical Sciences, Hong Kong, Hong Kong
| | - J Liao
- The Chinese University of Hong Kong, School of Biomedical Sciences, Hong Kong, Hong Kong
| | - A C S Luk
- The Chinese University of Hong Kong, School of Biomedical Sciences, Hong Kong, Hong Kong
| | - H C Suen
- The Chinese University of Hong Kong, School of Biomedical Sciences, Hong Kong, Hong Kong
| | - T H T Chan
- The Chinese University of Hong Kong, School of Biomedical Sciences, Hong Kong, Hong Kong
| | - M Y Cheung
- The Chinese University of Hong Kong, School of Biomedical Sciences, Hong Kong, Hong Kong
| | - D Chu
- The Chinese University of Hong Kong, School of Biomedical Sciences, Hong Kong, Hong Kong
| | - M Zhao
- The Chinese University of Hong Kong, Department of Obstetrics and Gynaecology, Hong Kong, Hong Kong
| | - Y L Chan
- The Chinese University of Hong Kong, Department of Obstetrics and Gynaecology, Hong Kong, Hong Kong
| | - T C Li
- The Chinese University of Hong Kong, Department of Obstetrics and Gynaecology, Hong Kong, Hong Kong
| | - T L Lee
- The Chinese University of Hong Kong, School of Biomedical Sciences, Hong Kong, Hong Kong
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Lee AWT, Ng JKW, Liao J, Luk AC, Suen AHC, Chan TTH, Cheung MY, Chu HT, Tang NLS, Zhao MP, Lian Q, Chan WY, Chan DYL, Leung TY, Chow KL, Wang W, Wang LH, Chen NCH, Yang WJ, Huang JY, Li TC, Lee TL. Single-cell RNA sequencing identifies molecular targets associated with poor in vitro maturation performance of oocytes collected from ovarian stimulation. Hum Reprod 2021; 36:1907-1921. [PMID: 34052851 DOI: 10.1093/humrep/deab100] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [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: 10/12/2020] [Revised: 03/08/2021] [Indexed: 12/14/2022] Open
Abstract
STUDY QUESTION What is the transcriptome signature associated with poor performance of rescue IVM (rIVM) oocytes and how can we rejuvenate them? SUMMARY ANSWER The GATA-1/CREB1/WNT signalling axis was repressed in rIVM oocytes, particularly those of poor quality; restoration of this axis may produce more usable rIVM oocytes. WHAT IS KNOWN ALREADY rIVM aims to produce mature oocytes (MII) for IVF through IVM of immature oocytes collected from stimulated ovaries. It is not popular due to limited success rate in infertility treatment. Genetic aberrations, cellular stress and the absence of cumulus cell support in oocytes could account for the failure of rIVM. STUDY DESIGN, SIZE, DURATION We applied single-cell RNA sequencing (scRNA-seq) to capture the transcriptomes of human in vivo oocytes (IVO) (n = 10) from 7 donors and rIVM oocytes (n = 10) from 10 donors. The effects of maternal age and ovarian responses on rIVM oocyte transcriptomes were also studied. In parallel, we studied the effect of gallic acid on the maturation rate of mouse oocytes cultured in IVM medium with (n = 84) and without (n = 85) gallic acid. PARTICIPANTS/MATERIALS, SETTING, METHODS Human oocytes were collected from donors aged 28-41 years with a body mass index of <30. RNA extraction, cDNA generation, library construction and sequencing were performed in one preparation. scRNA-seq data were then processed and analysed. Selected genes in the rIVM versus IVO comparison were validated by quantitative real-time PCR. For the gallic acid study, we collected immature oocytes from 5-month-old mice and studied the effect of 10-μM gallic acid on their maturation rate. MAIN RESULTS AND THE ROLE OF CHANCE The transcriptome profiles of rIVM/IVO oocytes showed distinctive differences. A total of 1559 differentially expressed genes (DEGs, genes with at least 2-fold change and adjusted P < 0.05) were found to be enriched in metabolic processes, biosynthesis and oxidative phosphorylation. Among these DEGs, we identified a repression of WNT/β-catenin signalling in rIVM when compared with IVO oocytes. We found that oestradiol levels exhibited a significant age-independent correlation with the IVO mature oocyte ratio (MII ratio) for each donor. rIVM oocytes from women with a high MII ratio were found to have over-represented cellular processes such as anti-apoptosis. To further identify targets that contribute to the poor clinical outcomes of rIVM, we compared oocytes collected from young donors with a high MII ratio with oocytes from donors of advanced maternal age and lower MII ratio, and revealed that CREB1 is an important regulator. Thus, our study identified that GATA-1/CREB1/WNT signalling was repressed in both rIVM oocytes versus IVO oocytes and in rIVM oocytes of lower versus higher quality. Consequently we investigated gallic acid, as a potential antioxidant substrate in human rIVM medium, and found that it increased the mouse oocyte maturation rate by 31.1%. LARGE SCALE DATA Raw data from this study can be accessed through GSE158539. LIMITATIONS, REASONS FOR CAUTION In the rIVM oocytes of the high- and low-quality comparison, the number of samples was limited after data filtering with stringent selection criteria. For the oocyte stage identification, we were unable to predict the presence of oocyte spindle, so polar body extrusion was the only indicator. WIDER IMPLICATIONS OF THE FINDINGS This study showed that GATA-1/CREB1/WNT signalling was repressed in rIVM oocytes compared with IVO oocytes and was further downregulated in low-quality rIVM oocytes, providing us the foundation of subsequent follow-up research on human oocytes and raising safety concerns about the clinical use of rescued oocytes. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the Collaborative Research Fund, Research Grants Council, C4054-16G, and Research Committee Funding (Research Sustainability of Major RGC Funding Schemes), The Chinese University of Hong Kong. The authors have no conflicts of interest to declare.
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Affiliation(s)
- A W T Lee
- Developmental and Regenerative Biology Program, School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, PR China
| | - J K W Ng
- Developmental and Regenerative Biology Program, School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, PR China
| | - J Liao
- Developmental and Regenerative Biology Program, School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, PR China
| | - A C Luk
- Developmental and Regenerative Biology Program, School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, PR China
| | - A H C Suen
- Developmental and Regenerative Biology Program, School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, PR China
| | - T T H Chan
- Developmental and Regenerative Biology Program, School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, PR China
| | - M Y Cheung
- Developmental and Regenerative Biology Program, School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, PR China
| | - H T Chu
- Developmental and Regenerative Biology Program, School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, PR China
| | - N L S Tang
- Department of Chemical Pathology, and Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, PR China
| | - M P Zhao
- Assisted Reproductive Technology Unit, Department of Obstetrics and Gynaecology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, PR China
| | - Q Lian
- Department of Medicine, The University of Hong Kong, Hong Kong SAR, PR China
| | - W Y Chan
- Developmental and Regenerative Biology Program, School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, PR China
| | - D Y L Chan
- Assisted Reproductive Technology Unit, Department of Obstetrics and Gynaecology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, PR China
| | - T Y Leung
- Department of Medicine, The University of Hong Kong, Hong Kong SAR, PR China
| | - K L Chow
- Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, N.T., Hong Kong SAR, PR China.,Division of Life Science, Hong Kong University of Science and Technology, Shatin, N.T., Hong Kong SAR, PR China
| | - W Wang
- Department of Obstetrics and Gynecology, IVF Center, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - L H Wang
- Institute of Molecular and Cellular Biology & Department of Medical Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - N C H Chen
- Department of Infertility and Reproductive Medicine, Taiwan IVF Group Center, Hsinchu City, Taiwan
| | - W J Yang
- Department of Infertility and Reproductive Medicine, Taiwan IVF Group Center, Hsinchu City, Taiwan
| | - J Y Huang
- Department of Infertility and Reproductive Medicine, Taiwan IVF Group Center, Hsinchu City, Taiwan
| | - T C Li
- Assisted Reproductive Technology Unit, Department of Obstetrics and Gynaecology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, PR China
| | - T L Lee
- Developmental and Regenerative Biology Program, School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, PR China
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Tang P, Lee T, To K, Lan H, Tang P. 91P Macrophage-lineage transcriptome networking reveals SMAD3 as a novel regulator for cancer-associated fibroblasts formation in NSCLC. Ann Oncol 2020. [DOI: 10.1016/j.annonc.2020.10.579] [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] Open
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Ryan PTP, Meier M, Jakub Z, Balajka J, Hulva J, Payne DJ, Lee TL, Franchini C, Allegretti F, Parkinson GS, Duncan DA. Probing structural changes upon carbon monoxide coordination to single metal adatoms. J Chem Phys 2020; 152:051102. [DOI: 10.1063/1.5137904] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Affiliation(s)
- P. T. P. Ryan
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0QX, United Kingdom
- Department of Materials, Imperial College London, London SW7 2AZ, United Kingdom
| | - M. Meier
- Institute of Applied Physics, TU Wien, 1040 Vienna, Austria
- University of Vienna, Faculty of Physics and Center for Computational Materials Science, 1090 Vienna, Austria
| | - Z. Jakub
- Institute of Applied Physics, TU Wien, 1040 Vienna, Austria
| | - J. Balajka
- University of Vienna, Faculty of Physics and Center for Computational Materials Science, 1090 Vienna, Austria
| | - J. Hulva
- Institute of Applied Physics, TU Wien, 1040 Vienna, Austria
| | - D. J. Payne
- Department of Materials, Imperial College London, London SW7 2AZ, United Kingdom
| | - T.-L. Lee
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0QX, United Kingdom
| | - C. Franchini
- University of Vienna, Faculty of Physics and Center for Computational Materials Science, 1090 Vienna, Austria
| | - F. Allegretti
- Physics Department E20, Technical University of Munich, 85748 Garching, Germany
| | | | - D. A. Duncan
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0QX, United Kingdom
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Sunko V, Mazzola F, Kitamura S, Khim S, Kushwaha P, Clark OJ, Watson MD, Marković I, Biswas D, Pourovskii L, Kim TK, Lee TL, Thakur PK, Rosner H, Georges A, Moessner R, Oka T, Mackenzie AP, King PDC. Probing spin correlations using angle-resolved photoemission in a coupled metallic/Mott insulator system. Sci Adv 2020; 6:eaaz0611. [PMID: 32128385 PMCID: PMC7032925 DOI: 10.1126/sciadv.aaz0611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 10/29/2019] [Indexed: 06/10/2023]
Abstract
A nearly free electron metal and a Mott insulating state can be thought of as opposite ends of the spectrum of possibilities for the motion of electrons in a solid. Understanding their interaction lies at the heart of the correlated electron problem. In the magnetic oxide metal PdCrO2, nearly free and Mott-localized electrons exist in alternating layers, forming natural heterostructures. Using angle-resolved photoemission spectroscopy, quantitatively supported by a strong coupling analysis, we show that the coupling between these layers leads to an "intertwined" excitation that is a convolution of the charge spectrum of the metallic layer and the spin susceptibility of the Mott layer. Our findings establish PdCrO2 as a model system in which to probe Kondo lattice physics and also open new routes to use the a priori nonmagnetic probe of photoemission to gain insights into the spin susceptibility of correlated electron materials.
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Affiliation(s)
- V. Sunko
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - F. Mazzola
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| | - S. Kitamura
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany
| | - S. Khim
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - P. Kushwaha
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - O. J. Clark
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| | - M. D. Watson
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| | - I. Marković
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - D. Biswas
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
| | - L. Pourovskii
- CPHT, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, F-91128 Palaiseau, France
- Institut de Physique, Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
| | - T. K. Kim
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, UK
| | - T.-L. Lee
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, UK
| | - P. K. Thakur
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, UK
| | - H. Rosner
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - A. Georges
- CPHT, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, F-91128 Palaiseau, France
- Institut de Physique, Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France
- Center for Computational Quantum Physics, Flatiron Institute, New York, NY 10010, USA
- DQMP, Université de Genève, 24 quai Ernest Ansermet, CH-1211 Genève, Switzerland
| | - R. Moessner
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany
| | - T. Oka
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany
| | - A. P. Mackenzie
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Straße 40, 01187 Dresden, Germany
| | - P. D. C. King
- SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
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Blowey P, Maurer R, Rochford L, Duncan D, Kang JH, Warr D, Ramadan A, Lee TL, Thakur P, Costantini G, Reuter K, Woodruff D. The Structure of VOPc on Cu(111): Does V=O Point Up, or Down, or Both? J Phys Chem C Nanomater Interfaces 2019; 123:8101-8111. [PMID: 30976375 PMCID: PMC6453023 DOI: 10.1021/acs.jpcc.8b07530] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 09/24/2018] [Indexed: 05/17/2023]
Abstract
The local structure of the nonplanar phthalocyanine, vanadyl phthalocyanine (VOPc), adsorbed on Cu(111) at a coverage of approximately one-half of a saturated molecular layer, has been investigated by a combination of normal-incidence X-ray standing waves (NIXSW), scanned-energy mode photoelectron diffraction (PhD), and density-functional theory (DFT), complemented by scanning tunnelling microscopy (STM). Qualitative assessment of the NIXSW data clearly shows that both "up" and "down" orientations of the molecule (with V=O pointing out of, and into, the surface) must coexist on the surface. O 1s PhD proves to be inconclusive regarding the molecular orientation. DFT calculations, using two different dispersion correction schemes, show good quantitative agreement with the NIXSW structural results for equal co-occupation of the two different molecular orientations and clearly favor the many body dispersion (MBD) method to deal with long-range dispersion forces. The calculated relative adsorption energies of the differently oriented molecules at the lowest coverage show a strong preference for the "up" orientation, but at higher local coverages, this energetic difference decreases, and mixed orientation phases are almost energetically equivalent to pure "up"-oriented phases. DFT-based Tersoff-Hamann simulations of STM topographs for the two orientations cast some light on the extent to which such images provide a reliable guide to molecular orientation.
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Affiliation(s)
- P.J. Blowey
- Department of Physics and Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
- Diamond
Light Source, Didcot OX11 0QX, U.K.
| | - R.J. Maurer
- Department of Physics and Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
| | - L.A. Rochford
- Department of Physics and Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
- School
of Chemistry, University of Birmingham, Birmingham B15 2TT, U.K.
| | - D.A. Duncan
- Diamond
Light Source, Didcot OX11 0QX, U.K.
- Physik-Department
E20, Technische Universität München, 85748 Garching, Germany
| | - J.-H. Kang
- Department
of Nano and Electronic Physics, Kookmin
University, Seoul 136-702, Korea
| | - D.A. Warr
- Department of Physics and Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
| | - A.J. Ramadan
- Clarendon
Laboratory, Department of Physics, University
of Oxford, Oxford OX1 3PU, U.K.
| | - T.-L. Lee
- Diamond
Light Source, Didcot OX11 0QX, U.K.
| | | | - G. Costantini
- Department of Physics and Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
| | - K. Reuter
- Department
Chemie, Technische Universität München, 85748 Garching, Germany
| | - D.P. Woodruff
- Department of Physics and Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
- E-mail:
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Blowey PJ, Velari S, Rochford LA, Duncan DA, Warr DA, Lee TL, De Vita A, Costantini G, Woodruff DP. Re-evaluating how charge transfer modifies the conformation of adsorbed molecules. Nanoscale 2018; 10:14984-14992. [PMID: 30051899 PMCID: PMC6088372 DOI: 10.1039/c8nr02237b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Accepted: 06/13/2018] [Indexed: 05/17/2023]
Abstract
The archetypal electron acceptor molecule, TCNQ, is generally believed to become bent into an inverted bowl shape upon adsorption on the coinage metal surfaces on which it becomes negatively charged. New quantitative experimental structural measurements show that this is not the case for TCNQ on Ag(111). DFT calculations show that the inclusion of dispersion force corrections reduces not only the molecule-substrate layer spacing but also the degree of predicted molecular bonding. However, complete agreement between experimentally-determined and theoretically-predicted structural parameters is only achieved with the inclusion of Ag adatoms into the molecular layer, which is also the energetically favoured configuration. The results highlight the need for both experimental and theoretical quantitative structural methods to reliably understand similar metal-organic interfaces and highlight the need to re-evaluate some previously-investigated systems.
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Affiliation(s)
- P. J. Blowey
- Physics Department
, University of Warwick
,
Coventry CV4 7AL
, UK
.
- Diamond Light Source
,
Didcot
, OX11 0DE
, UK
| | - S. Velari
- Dipartimento di Ingegneria e Architettura
, Università degli Studi di Trieste
,
V. Valerio 10
, Trieste
, Italy
| | - L. A. Rochford
- Department of Chemistry
, University of Warwick
,
Coventry CV4 7AL
, UK
.
- School of Chemistry
, University of Birmingham
,
Edgbaston
, Birmingham
, B15 2TT
, UK
| | | | - D. A. Warr
- Department of Chemistry
, University of Warwick
,
Coventry CV4 7AL
, UK
.
| | - T.-L. Lee
- Diamond Light Source
,
Didcot
, OX11 0DE
, UK
| | - A. De Vita
- Dipartimento di Ingegneria e Architettura
, Università degli Studi di Trieste
,
V. Valerio 10
, Trieste
, Italy
- Department of Physics
, King's College London
,
Strand
, London
, WC2R 2LS
, UK
| | - G. Costantini
- Department of Chemistry
, University of Warwick
,
Coventry CV4 7AL
, UK
.
| | - D. P. Woodruff
- Physics Department
, University of Warwick
,
Coventry CV4 7AL
, UK
.
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Lee TL, Reinhardt CD, Bartle SJ, Vahl CI, Siemens M, Thomson DU. Assessment of risk factors contributing to carcass bruising in fed cattle at commercial slaughter facilities. Transl Anim Sci 2017; 1:489-497. [PMID: 32704672 PMCID: PMC7204972 DOI: 10.2527/tas2017.0055] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 09/14/2017] [Indexed: 11/25/2022] Open
Abstract
Cattle injuries can occur during transportation due to vehicle design, transport conditions, and loading or unloading procedures and lead to carcass bruising and economic loss due to decreased carcass value. The objectives of this study were to determine whether a relationship exists between trauma incurred during unloading and prevalence of carcass bruising in finished beef cattle at commercial slaughter facilities and determine related risk factors which contribute to both trauma and carcass bruising. Breed (classified as either Holstein cattle or beef breeds), sex, distance traveled, and trailer type (“fat/feeder combination” vs. “fat” trailer) were considered risk factors which may contribute to traumatic event prevalence. When carcass bruise prevalence within each lot was used as the dependent variable, breed, sex, distance traveled, traumatic event prevalence, ribeye area, fat thickness, yield grade, and average carcass weight were considered potential risk factors. Carcass bruises were categorized by location and size, according to the Harvest Audit Program Carcass Bruise Scoring System. Traumatic events were observed while cattle exited trailers onto the unloading docks, and were categorized by location on the animal. Average traumatic event prevalence per lot was 20.4% (± 1.11%). Average carcass bruise prevalence by lot was 68.2% (± 1.15%). There was an interaction between breed and trailer type when multiple linear regression was used to explore variables contributing to traumatic events observed at unloading (P ≤ 0.05). Traumatic events were not associated with prevalence of carcass bruising, while average carcass weight and breed were associated with carcass bruising prevalence. Carcass bruising was more prevalent in Holstein cattle than in cattle which were predominantly beef breeds (P ≤ 0.01). Average carcass weight was negatively associated with carcass bruise prevalence (P ≤ 0.05). The association between traumatic events at unloading and carcass bruising is not significant when multiple variables are considered, indicating that bruising may occur at numerous other points prior to and during the transportation process, including loading and transport, and that other variables can contribute to carcass bruise prevalence. These areas should be explored to determine all potential causes of bruising in beef carcasses, and to help implement prevention practices.
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Affiliation(s)
- T L Lee
- North American Meat Institute, Washington, DC 20036
| | | | | | - C I Vahl
- Department of Statistics, Kansas State University, Manhattan 66506
| | | | - D U Thomson
- Department of Diagnostic Medicine & Pathobiology, Kansas State University, Manhattan 66506
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Lee HL, McCulloh D, Adler A, Lee TL, Hodes-Wertz B, Grifo J. Live births and ongoing pregnancies after thawed euploid embryo transfer in women 40 to 43. Fertil Steril 2014. [DOI: 10.1016/j.fertnstert.2014.07.625] [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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Goldman K, McCaffrey C, Noyes N, Goldstein-Tufaro A, Lee TL, Grifo J. Blame it on the rain: salvaging in vitro fertilization (IVF) cycles threatened by hurricane sandy (HS) using emergency oocyte cryopreservation (EOC). Fertil Steril 2013. [DOI: 10.1016/j.fertnstert.2013.07.613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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13
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Lee HL, Hodes-Wertz B, Alexis A, Lee TL, McCulloh D, Grifo J. Preimplantation genetic screening improve IVF sucess rate in women over 40. Fertil Steril 2013. [DOI: 10.1016/j.fertnstert.2013.07.1957] [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: 10/26/2022]
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Lee HL, Adler A, Ampeloquio E, Lee TL, Berkeley A, Grifo J. Trophectoderm (TE) biopsy with vitrification on day 5/6 followed by a frozen embryo transfer (FET) results in high implantation rate (IR), clinical pregnancy rate (CPR) and is superior to day 3 biopsy. Fertil Steril 2012. [DOI: 10.1016/j.fertnstert.2012.07.497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Li R, Yang W, Zhang J, Hirankarn N, Pan HF, Mok CC, Chan TM, Wong RWS, Mok MY, Lee KW, Wong SN, Leung AMH, Li XP, Avihingsanon Y, Lee TL, Ho MHK, Lee PPW, Wong WHS, Wong CM, Ng IOL, Yang J, Li PH, Zhang Y, Zhang L, Li W, Baum L, Kwan P, Rianthavorn P, Deekajorndej T, Suphapeetiporn K, Shotelersuk V, Garcia-Barceló MM, Cherny SS, Tam PKH, Sham PC, Lau CS, Shen N, Lau YL, Ye DQ. Association of CD247 with systemic lupus erythematosus in Asian populations. Lupus 2011; 21:75-83. [PMID: 22004975 DOI: 10.1177/0961203311422724] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease with complex genetic inheritance. CD247 (CD3Z, TCRZ) plays a vital role in antigen recognition and signal transduction in antigen-specific immune responses, and is known to be involved in SLE pathogenesis. Weak disease association was reported for genetic variants in this gene in Caucasian studies for SLE, Crohn's disease and systemic sclerosis, but its role as a genetic risk factor was never firmly established. METHODS In this study, using a collection of 612 SLE patients and 2193 controls of Chinese ethnicity living in Hong Kong in a genome-wide study, single nucleotide polymorphisms (SNPs) in and around CD247 were identified as being associated with SLE. The two most significant SNPs in this locus were selected for further replication using TaqMan genotyping assay in 3339 Asian patients from Hong Kong, Mainland China, and Thailand, as well as 4737 ethnically and geographically matched controls. RESULTS The association of CD247 with SLE in Asian populations was confirmed (rs704853: odds ratio [OR] = 0. 81, p = 2.47 × 10(-7); rs858543: OR = 1.10, p = 0.0048). Patient-only analysis suggested that rs704853 is also linked to oral ulcers, hematologic disorders and anti-double-stranded DNA (dsDNA) antibody production. CONCLUSION A significant association between variants in CD247 and SLE was demonstrated in Asian populations. Understanding the involvement of CD247 in SLE may shed new light on disease mechanisms and development of new treatment paradigms.
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Affiliation(s)
- R Li
- Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, China
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Glenzer SH, MacGowan BJ, Meezan NB, Adams PA, Alfonso JB, Alger ET, Alherz Z, Alvarez LF, Alvarez SS, Amick PV, Andersson KS, Andrews SD, Antonini GJ, Arnold PA, Atkinson DP, Auyang L, Azevedo SG, Balaoing BNM, Baltz JA, Barbosa F, Bardsley GW, Barker DA, Barnes AI, Baron A, Beeler RG, Beeman BV, Belk LR, Bell JC, Bell PM, Berger RL, Bergonia MA, Bernardez LJ, Berzins LV, Bettenhausen RC, Bezerides L, Bhandarkar SD, Bishop CL, Bond EJ, Bopp DR, Borgman JA, Bower JR, Bowers GA, Bowers MW, Boyle DT, Bradley DK, Bragg JL, Braucht J, Brinkerhoff DL, Browning DF, Brunton GK, Burkhart SC, Burns SR, Burns KE, Burr B, Burrows LM, Butlin RK, Cahayag NJ, Callahan DA, Cardinale PS, Carey RW, Carlson JW, Casey AD, Castro C, Celeste JR, Chakicherla AY, Chambers FW, Chan C, Chandrasekaran H, Chang C, Chapman RF, Charron K, Chen Y, Christensen MJ, Churby AJ, Clancy TJ, Cline BD, Clowdus LC, Cocherell DG, Coffield FE, Cohen SJ, Costa RL, Cox JR, Curnow GM, Dailey MJ, Danforth PM, Darbee R, Datte PS, Davis JA, Deis GA, Demaret RD, Dewald EL, Di Nicola P, Di Nicola JM, Divol L, Dixit S, Dobson DB, Doppner T, Driscoll JD, Dugorepec J, Duncan JJ, Dupuy PC, Dzenitis EG, Eckart MJ, Edson SL, Edwards GJ, Edwards MJ, Edwards OD, Edwards PW, Ellefson JC, Ellerbee CH, Erbert GV, Estes CM, Fabyan WJ, Fallejo RN, Fedorov M, Felker B, Fink JT, Finney MD, Finnie LF, Fischer MJ, Fisher JM, Fishler BT, Florio JW, Forsman A, Foxworthy CB, Franks RM, Frazier T, Frieder G, Fung T, Gawinski GN, Gibson CR, Giraldez E, Glenn SM, Golick BP, Gonzales H, Gonzales SA, Gonzalez MJ, Griffin KL, Grippen J, Gross SM, Gschweng PH, Gururangan G, Gu K, Haan SW, Hahn SR, Haid BJ, Hamblen JE, Hammel BA, Hamza AV, Hardy DL, Hart DR, Hartley RG, Haynam CA, Heestand GM, Hermann MR, Hermes GL, Hey DS, Hibbard RL, Hicks DG, Hinkel DE, Hipple DL, Hitchcock JD, Hodtwalker DL, Holder JP, Hollis JD, Holtmeier GM, Huber SR, Huey AW, Hulsey DN, Hunter SL, Huppler TR, Hutton MS, Izumi N, Jackson JL, Jackson MA, Jancaitis KS, Jedlovec DR, Johnson B, Johnson MC, Johnson T, Johnston MP, Jones OS, Kalantar DH, Kamperschroer JH, Kauffman RL, Keating GA, Kegelmeyer LM, Kenitzer SL, Kimbrough JR, King K, Kirkwood RK, Klingmann JL, Knittel KM, Kohut TR, Koka KG, Kramer SW, Krammen JE, Krauter KG, Krauter GW, Krieger EK, Kroll JJ, La Fortune KN, Lagin LJ, Lakamsani VK, Landen OL, Lane SW, Langdon AB, Langer SH, Lao N, Larson DW, Latray D, Lau GT, Le Pape S, Lechleiter BL, Lee Y, Lee TL, Li J, Liebman JA, Lindl JD, Locke SF, Loey HK, London RA, Lopez FJ, Lord DM, Lowe-Webb RR, Lown JG, Ludwigsen AP, Lum NW, Lyons RR, Ma T, MacKinnon AJ, Magat MD, Maloy DT, Malsbury TN, Markham G, Marquez RM, Marsh AA, Marshall CD, Marshall SR, Maslennikov IL, Mathisen DG, Mauger GJ, Mauvais MY, McBride JA, McCarville T, McCloud JB, McGrew A, McHale B, MacPhee AG, Meeker JF, Merill JS, Mertens EP, Michel PA, Miller MG, Mills T, Milovich JL, Miramontes R, Montesanti RC, Montoya MM, Moody J, Moody JD, Moreno KA, Morris J, Morriston KM, Nelson JR, Neto M, Neumann JD, Ng E, Ngo QM, Olejniczak BL, Olson RE, Orsi NL, Owens MW, Padilla EH, Pannell TM, Parham TG, Patterson RW, Pavel G, Prasad RR, Pendlton D, Penko FA, Pepmeier BL, Petersen DE, Phillips TW, Pigg D, Piston KW, Pletcher KD, Powell CL, Radousky HB, Raimondi BS, Ralph JE, Rampke RL, Reed RK, Reid WA, Rekow VV, Reynolds JL, Rhodes JJ, Richardson MJ, Rinnert RJ, Riordan BP, Rivenes AS, Rivera AT, Roberts CJ, Robinson JA, Robinson RB, Robison SR, Rodriguez OR, Rogers SP, Rosen MD, Ross GF, Runkel M, Runtal AS, Sacks RA, Sailors SF, Salmon JT, Salmonson JD, Saunders RL, Schaffer JR, Schindler TM, Schmitt MJ, Schneider MB, Segraves KS, Shaw MJ, Sheldrick ME, Shelton RT, Shiflett MK, Shiromizu SJ, Shor M, Silva LL, Silva SA, Skulina KM, Smauley DA, Smith BE, Smith LK, Solomon AL, Sommer S, Soto JG, Spafford NI, Speck DE, Springer PT, Stadermann M, Stanley F, Stone TG, Stout EA, Stratton PL, Strausser RJ, Suter LJ, Sweet W, Swisher MF, Tappero JD, Tassano JB, Taylor JS, Tekle EA, Thai C, Thomas CA, Thomas A, Throop AL, Tietbohl GL, Tillman JM, Town RPJ, Townsend SL, Tribbey KL, Trummer D, Truong J, Vaher J, Valadez M, Van Arsdall P, Van Prooyen AJ, Vergel de Dios EO, Vergino MD, Vernon SP, Vickers JL, Villanueva GT, Vitalich MA, Vonhof SA, Wade FE, Wallace RJ, Warren CT, Warrick AL, Watkins J, Weaver S, Wegner PJ, Weingart MA, Wen J, White KS, Whitman PK, Widmann K, Widmayer CC, Wilhelmsen K, Williams EA, Williams WH, Willis L, Wilson EF, Wilson BA, Witte MC, Work K, Yang PS, Young BK, Youngblood KP, Zacharias RA, Zaleski T, Zapata PG, Zhang H, Zielinski JS, Kline JL, Kyrala GA, Niemann C, Kilkenny JD, Nikroo A, Van Wonterghem BM, Atherton LJ, Moses EI. Demonstration of ignition radiation temperatures in indirect-drive inertial confinement fusion hohlraums. Phys Rev Lett 2011; 106:085004. [PMID: 21405580 DOI: 10.1103/physrevlett.106.085004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Indexed: 05/30/2023]
Abstract
We demonstrate the hohlraum radiation temperature and symmetry required for ignition-scale inertial confinement fusion capsule implosions. Cryogenic gas-filled hohlraums with 2.2 mm-diameter capsules are heated with unprecedented laser energies of 1.2 MJ delivered by 192 ultraviolet laser beams on the National Ignition Facility. Laser backscatter measurements show that these hohlraums absorb 87% to 91% of the incident laser power resulting in peak radiation temperatures of T(RAD)=300 eV and a symmetric implosion to a 100 μm diameter hot core.
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Affiliation(s)
- S H Glenzer
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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Lee TL, Tseng WK, Hsu KL. Circumferential compression of bilateral ventricles by tuberculous granuloma leading to heart failure. Eur Heart J 2010; 31:3083. [DOI: 10.1093/eurheartj/ehq300] [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: 11/14/2022] Open
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Chaudhuri A, Jackson DC, Lerotholi TJ, Jones RG, Lee TL, Detlefs B, Woodruff DP. Structural investigation of Au(111)/butylthiolate adsorption phases. Phys Chem Chem Phys 2010; 12:3229-38. [DOI: 10.1039/b921281g] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Zegenhagen J, Lee TL, Gründer Y, Renner FU, Fimland BO. The Adsorption and Growth of Copper on As-Terminated GaAs(001): Physical Vapour versus Electrochemical Deposition. ACTA ACUST UNITED AC 2009. [DOI: 10.1524/zpch.2007.221.9-10.1273] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The adsorption of copper deposited from an effusion cell in ultra high vacuum and electrodeposited from aqueous solution on As-terminated GaAs(001) is investigated by scanning tunneling microscopy, X-ray diffraction, as well as X-ray standing waves in combination with X-ray fluorescence spectroscopy. The analysis of the adsorbate is performed in situ with the samples either in ultra high vacuum or in aqueous electrolyte under potential control. Deposited as Cu ions from sulphuric acid solution, submonolayer coverages of Cu diffuse into the GaAs interface region assumimg predominantly Ga substitutional positions. Different positions with lower symmetry are occupied by Cu if submonolayer are deposited at room temperature in ultra high vacuum. At higher coverage, epitaxial Cu clusters grow by electrodeposition on the As-terminated GaAs(001), but with the Cu lattice of the islands rotated and inclined with respect to the GaAs substrate lattice, leading in total to eight equivalent domains. At comparable coverage, no epitaxial growth was observed for Cu deposited in ultra high vacuum.
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Abstract
D-Serine, an endogenous modulator of NMDA receptors has been shown to play a vital role in many neuropsychiatric functions such as learning, memory, nociception and implicated in pathological conditions like schizophrenia and Alzheimer's disease. We propose possible therapeutic approaches for some CNS diseases and chronic pain, targeting the D-serine levels by manipulating its uptake, biosynthesis and metabolism.
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Affiliation(s)
- R Sethuraman
- Department of Anaesthesia, National University of Singapore, 5 Lower Kent Ridge Road, Singapore 119074
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Chang YK, Yang W, Zhao M, Mok CC, Chan TM, Wong RWS, Lee KW, Mok MY, Wong SN, Ng IOL, Lee TL, Ho MHK, Lee PPW, Wong WHS, Lau CS, Sham PC, Lau YL. Association of BANK1 and TNFSF4 with systemic lupus erythematosus in Hong Kong Chinese. Genes Immun 2009; 10:414-20. [PMID: 19357697 PMCID: PMC2834352 DOI: 10.1038/gene.2009.16] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [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: 01/05/2009] [Revised: 03/04/2009] [Accepted: 03/05/2009] [Indexed: 11/30/2022]
Abstract
Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease with complex genetic inheritance. Recently, single nucleotide polymorphisms (SNPs) in BANK1 and TNFSF4 have been shown to be associated with SLE in Caucasian populations, but it is not known whether they are also involved in the disease in other ethnic groups. Recent data from our genome-wide association study (GWAS) for 314 SLE cases and 920 controls collected in Hong Kong identified SNPs in and around BANK1 and TNFSF4 to be associated with SLE risk. On the basis of the results of the reported studies and our GWAS, SNPs were selected for further genotyping in 949 SLE patients (overlapping with the 314 cases in our GWAS) and non-overlapping 1042 healthy controls. We confirmed the associations of BANK1 and TNFSF4 with SLE in Chinese (BANK1, rs3733197, odds ratio (OR)=0.84, P=0.021; BANK1, rs17266594, OR=0.61, P=4.67 x 10(-9); TNFSF4, rs844648, OR=1.22, P=2.47 x 10(-3); TNFSF4, rs2205960, OR=1.30, P=2.41 x 10(-4)). Another SNP located in intron 1 of BANK1, rs4522865, was separately replicated by Sequenom in 360 cases and 360 controls and was also confirmed to be associated with SLE (OR=0.725, P=2.93 x 10(-3)). Logistic regression analysis showed that rs3733197 (A383T in ankyrin domain) and rs17266594 (a branch point-site SNP) from BANK1 had independent contributions towards the disease association (P=0.037 and 6.63 x 10(-8), respectively). In TNFSF4, rs2205960 was associated with SLE independently from the effect of rs844648 (P=6.26 x 10(-3)), but not vice versa (P=0.55). These findings suggest that multiple independent genetic variants may be present within the gene locus, which exert their effects on SLE pathogenesis through different mechanisms.
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Affiliation(s)
- Y K Chang
- LKS Faculty of Medicine, Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong Hong Kong, China
| | - W Yang
- LKS Faculty of Medicine, Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong Hong Kong, China
| | - M Zhao
- LKS Faculty of Medicine, Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong Hong Kong, China
| | - C C Mok
- Department of Medicine, Tuen Mun Hospital, New Territory Hong Kong, China
| | - T M Chan
- LKS Faculty of Medicine, Department of Medicine, The University of Hong Kong Hong Kong, China
| | - R W S Wong
- LKS Faculty of Medicine, Department of Medicine, The University of Hong Kong Hong Kong, China
| | - K W Lee
- Department of Medicine, Pamela Youde Nethersole Eastern Hospital Hong Kong, China
| | - M Y Mok
- LKS Faculty of Medicine, Department of Medicine, The University of Hong Kong Hong Kong, China
| | - S N Wong
- Department of Paediatrics and Adolescent Medicine, Tuen Mun Hospital, New Territory Hong Kong, China
| | - I O L Ng
- LKS Faculty of Medicine, Department of Pathology, The University of Hong Kong Hong Kong, China
| | - T L Lee
- LKS Faculty of Medicine, Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong Hong Kong, China
| | - M H K Ho
- LKS Faculty of Medicine, Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong Hong Kong, China
| | - P P W Lee
- LKS Faculty of Medicine, Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong Hong Kong, China
| | - W H S Wong
- LKS Faculty of Medicine, Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong Hong Kong, China
| | - C S Lau
- LKS Faculty of Medicine, Department of Medicine, The University of Hong Kong Hong Kong, China
| | - P C Sham
- LKS Faculty of Medicine, Department of Psychiatry, The University of Hong Kong Hong Kong, China
| | - Y L Lau
- LKS Faculty of Medicine, Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong Hong Kong, China
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Chaudhuri A, Odelius M, Jones RG, Lee TL, Detlefs B, Woodruff DP. The structure of the Au(111)/methylthiolate interface: New insights from near-edge x-ray absorption spectroscopy and x-ray standing waves. J Chem Phys 2009; 130:124708. [DOI: 10.1063/1.3102095] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Ho MHK, Cheuk DKL, Lee TL, Ha SY, Lau YL. Haemophagocytic lymphohistiocytosis in Hong Kong children have a wider clinical spectrum. Hong Kong Med J 2008; 14:503-504. [PMID: 19060355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
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Adler A, Lee TL, Reh A, Krey L, Grifo J. Improved implantation rates and reduced miscarriage rates demonstrates the superiority of day 5 embryo transfer. Fertil Steril 2008. [DOI: 10.1016/j.fertnstert.2008.07.1198] [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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Cheuk DKL, Wang P, Lee TL, Chiang AKS, Ha SY, Lau YL, Chan GCF. Risk factors and mortality predictors of hepatic veno-occlusive disease after pediatric hematopoietic stem cell transplantation. Bone Marrow Transplant 2007; 40:935-44. [PMID: 17768390 DOI: 10.1038/sj.bmt.1705835] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [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: 01/03/2023]
Abstract
A cohort of 138 children with 144 hematopoietic stem cell transplantation (HSCT) performed in 1997-2006 were analyzed to evaluate risk factors and mortality predictors of hepatic veno-occlusive disease (VOD). Nineteen patients (13.2%) developed VOD (nine boys, median age 3.5 years) at 1-21 days after HSCT (median 13 days). Age < or =2 years at transplant (odds ratio (OR)=5.25, P=0.011), BU-CY conditioning (OR=5.16, P=0.001), thalassemia major (OR=3.97, P=0.015), platelet engraftment beyond day +21 (OR=8.67, P=0.025) were univariate risk factors for VOD. The first two remained significant in multivariate regression. Seven patients (36.8%) with VOD died, at a median of 44 days post transplant (range, 30-421 days). The 5-year survival was 62%. All surviving patients had normal liver function on follow-up at 0.5-9 years. Patients with VOD had higher 100-day mortality (16.3 vs 9.6%, P=0.024). Mortality predictors included donors other than autologous or matched sibling (hazard ratio (HR)=23.6, P=0.006), hepatic and cutaneous GVHD (HR=8.15, P=0.038), maximal weight gain >9% (HR=6.81, P=0.023), pleural effusion, intensive care unit admission, peak bilirubin >300 micromol l(-1) (HR=13.6, P=0.016), day +21 bilirubin >200 micromol l(-1) (HR=33.9, P=0.001), and rise of bilirubin >15 micromol l(-1) per day within the first week (HR=19.8, P=0.006). Mortality was substantially higher if >3 predictors were present (HR=33.9, P=0.001). Meticulous monitoring in high-risk patients and early treatment should be considered before VOD progresses beyond salvage.
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Affiliation(s)
- D K L Cheuk
- Department of Pediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong Special Administrative Region (SAR), Hong Kong, China.
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Kazi JA, Liu EHC, Lee TL, Tachibana S. Nocistatin attenuated the nociceptin induced c-Fos expression in the mouse hippocampus. Neuropeptides 2007; 41:227-31. [PMID: 17586043 DOI: 10.1016/j.npep.2007.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2007] [Revised: 04/08/2007] [Accepted: 04/08/2007] [Indexed: 10/23/2022]
Abstract
Nocistatin and nociceptin/orphaninFQ (N/OFQ) are the two new peptides which may have roles in nociception, memory, anxiety, and other biological functions. Nocistatin acts as a functional antagonist to N/OFQ in several functions, but their neuro-anatomical sites of interaction are unknown. We investigated the effect of combined intracerebroventricular (i.c.v.) injection of nocistatin with N/OFQ, on N/OFQ induced c-Fos expression in the mouse hippocampus, using c-Fos immunohistochemistry. We found that co-injection of nocistatin with N/OFQ significantly attenuated N/OFQ induced c-Fos expression in the hippocampus.
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Affiliation(s)
- J A Kazi
- Department of Anaesthesia, Yong Loo Lin School of Medicine, National University of Singapore, 5 Lower Kent Ridge Road, Singapore 119074, Singapore.
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Chang H, Noyes N, Lee T, Chin A, Krey L, Grifo J. P-232. Fertil Steril 2006. [DOI: 10.1016/j.fertnstert.2006.07.584] [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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Kwok JSY, Hui KH, Lee TL, Wong W, Lau YL, Wong RWS, Kim DL, Jones BM. Anti-cyclic citrullinated peptide: diagnostic and prognostic values in juvenile idiopathic arthritis and rheumatoid arthritis in a Chinese population. Scand J Rheumatol 2005; 34:359-66. [PMID: 16234183 DOI: 10.1080/03009740510026634] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [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: 10/25/2022]
Abstract
OBJECTIVE The incidence and clinical significance of anti-cyclic citrullinated peptide (CCP) antibodies in a cohort of Chinese patients with juvenile idiopathic arthritis (JIA) and adults with rheumatoid arthritis (RA) were studied. METHODS Anti-CCP antibodies were determined by enzyme-linked immunosorbent assay (ELISA) in 59 patients with JIA, 129 adult RA patients, 48 children with diseases other than JIA, 68 adult patients with rheumatic diseases other than RA, and 60 normal adults. Associations between anti-CCP antibodies and clinical and laboratory parameters were determined by Fisher's exact test. RESULTS Six of 59 (10.2%) patients with JIA and 71 of 129 (55%) patients with RA were positive for anti-CCP. Four of five RF-positive JIA patients and two of 54 RF-negative JIA patients were positive (p<0.001). One paediatric patient with allergy (0.9%) and two adult patients with rheumatic diseases other than RA (2.3%) were positive. All healthy controls were negative for anti-CCP. The specificity was 99.1% for JIA and 98.4% for RA. The sensitivity was 10.2% for JIA and 55% for RA. Positive predictive values were 85.7% for JIA and 97.3% for RA and negative predictive values were 66.9% for JIA and 68.5% for RA. CONCLUSION The anti-CCP antibody assay is a valuable tool for the diagnosis of RA and a subset of JIA in Chinese patients. It could be a useful predictive test for joint erosion in JIA of the polyarticular RF-positive subset and may be influential in the choice of the best therapeutic strategy in patients with recent-onset arthritis.
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Affiliation(s)
- J S Y Kwok
- Department of Pathology, Queen Mary Hospital, Hong Kong, P.P.China.
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Liu EHC, Lee TL. The teaching of anaesthesia in Singapore. Ann Acad Med Singap 2005; 34:140C-142C. [PMID: 16010395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
This article describes the development of undergraduate and postgraduate anaesthesia teaching and training in Singapore. Anaesthesia teaching has evolved from art and apprenticeship to become systematic, scientific and evidence-based, while retaining an emphasis on hands-on practical training. Simulator training provides unique advantages, which the University Department of Anaesthesia has utilised in integrated medical student teaching.
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Affiliation(s)
- E H C Liu
- Department of Anaesthesia, National University Hospital, Singapore
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Cheuk DKL, Wong WHS, Ma E, Lee TL, Ha SY, Lau YL, Chan GCF. Use of midazolam and ketamine as sedation for children undergoing minor operative procedures. Support Care Cancer 2005; 13:1001-9. [PMID: 15846522 DOI: 10.1007/s00520-005-0821-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [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: 12/23/2004] [Accepted: 04/07/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVES We used intravenous midazolam and ketamine for children undergoing minor operative procedures with satisfactory results. We aimed to further evaluate its efficacy and adverse effects in pediatric ward setting. METHODS This was a prospective study of all children undergoing minor operations with sedation in our pediatric general and oncology wards from July 1998 to June 1999. The procedures included lumber puncture+/-intrathecal chemotherapy, bone marrow aspiration+/-trephine biopsy, central venous catheter removal, skin biopsy, or their combination. All sedation procedures were started with midazolam 0.1 mg/kg and ketamine 1 mg/kg; they were increased gradually to 0.4 and 4 mg/kg, respectively, if necessary. Heart rate and SaO2 were continuously monitored. RESULTS Altogether, 369 minor operations were performed in 112 patients (male:female=2:1, median age 6 years, range 5 months-17 years). All achieved adequate sedation, with 96% within 30 s and 75% required just the starting dose. Younger children required a higher dosage (p=0.003 for midazolam, p<0.001 for ketamine). The median recovery time was 87 min, with no association with age, sex, or dosage of sedation, but was longer in patients having hallucination (p=0.001). Adverse effects included tachycardia (27.9%), increased secretion (17.6%), agitation (13.6%), nausea and vomiting (9.2%), hallucination (8.7%), desaturation (8.4%), and cataleptic reaction (0.8%). All desaturation episodes were transient and responded to oxygen supplement alone. None developed bronchospasm or convulsion. Some adverse effects were dose-related. Half of the children who received 0.3 mg/kg midazolam developed desaturation. CONCLUSIONS Intravenous midazolam-ketamine can provide rapid, effective, and safe sedation for children undergoing minor operations in ward setting. Adverse effects are mild. Midazolam above 0.3 mg/kg should be used with caution.
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Affiliation(s)
- D K L Cheuk
- Department of Pediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong, 121 Pokfulam Road, Hong Kong, Hong Kong.
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Lam DST, Lee TL, Chan KW, Ho HK, Lau YL. Primary immunodeficiency in Hong Kong and the use of genetic analysis for diagnosis. Hong Kong Med J 2005; 11:90-6. [PMID: 15815061] [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: 05/02/2023] Open
Abstract
OBJECTIVES To review the management of primary immunodeficiency and discuss recent advances in genetic analysis. DESIGN Retrospective study. SETTING University teaching hospital, Hong Kong. PATIENTS Children diagnosed with primary immunodeficiency and followed up in the immunology clinic during the period 1988 to 2003. MAIN OUTCOME MEASURES Demographic data, co-morbidities and treatment of patients, outcome and complications; identification of disease by genetic mutations. RESULTS Medical records of a total of 117 patients (72 male, 45 female) diagnosed with primary immunodeficiency in the Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, Hong Kong during the past 15 years (1988-2003) were reviewed. All patients were followed up in the immunology clinic. Some patients had been referred from the private sector or other hospitals for immunological workup. Six categories of primary immunodeficiency were identified: predominantly humoral defect (n=50), predominantly cellular defect (n=22), combined humoral and cellular defect (n=5), phagocytic defect (n=18), complement disorders (n=4), and others (n=18). Although infection was the underlying cause of most co-morbidities and mortality, autoimmune (n=7) and allergic (n=23) manifestations were common. In addition, three patients developed lymphoma. Recent advances in the genetic diagnosis of several types of primary immunodeficiency were also reviewed: X-linked Wiskott-Aldrich syndrome, X-linked chronic granulomatous disease, X-linked agammaglobulinaemia, X-linked lymphoproliferative syndrome, leukocyte adhesion disease type I, and X-linked hyperimmunoglobulin M syndrome. This provides an invaluable means of understanding the molecular basis of primary immunodeficiency and has important clinical applications. CONCLUSIONS Co-morbidities like autoimmune disease and allergic disease are common in patients with primary immunodeficiency and should be carefully evaluated. Likewise, a diagnosis of primary immunodeficiency should be considered when evaluating patients with these conditions. Rapid progress in the field of molecular genetics will enable definite and early diagnosis, and more importantly, potential curative therapy to be administered.
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Affiliation(s)
- D S T Lam
- Department of Paediatrics and Adolescent Medicine, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong
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Liu EHC, Wong HK, Chia CP, Lim HJ, Chen ZY, Lee TL. Effects of isoflurane and propofol on cortical somatosensory evoked potentials during comparable depth of anaesthesia as guided by bispectral index. Br J Anaesth 2004; 94:193-7. [PMID: 15516356 DOI: 10.1093/bja/aei003] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The aim of this study was to determine if propofol caused less suppression of cortical somatosensory evoked potentials (SSEPs) during spine surgery compared with isoflurane during comparable depth of anaesthesia as guided by bispectral index (BIS) measurements. METHODS This was a randomized controlled trial of propofol and isoflurane involving 60 patients undergoing elective spine surgery. BIS monitoring was used to guide a consistent and comparable depth of anaesthesia, the index was maintained at between 40 and 50 during anaesthesia. The cortical SSEP P40-N50 peak-to-peak amplitude and latency time to the P40 peak were measured before induction of anaesthesia, after induction of anaesthesia, at the start of skin incision, at the start of pedicle screw insertion and at the start of rod insertion, by a neurophysiologist blinded to drug allocation. RESULTS Both propofol and isoflurane decreased SSEP amplitude and increased latency during the course of anaesthesia. After achieving a comparable depth of anaesthesia, the SSEP amplitude was significantly lower with isoflurane, 1.5 (1.0) vs 2.4 (1.4) muV (P=0.005). Latency was significantly longer with isoflurane, 39.5 (3.9) vs 37.3 (3.1) ms (P=0.024). Isoflurane was associated with greater variability of SSEP amplitude during the course of anaesthesia and surgery, coefficient of variation 35.4 (18.0) vs 21.2 (10.2)% (P=0.008). CONCLUSIONS Propofol anaesthesia caused less suppression of the cortical SSEP, with better preservation of SSEP amplitude, and less variability at an equivalent depth of anaesthesia.
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Affiliation(s)
- E H C Liu
- Department of Anaesthesia, National University Hospital, 5 Lower Kent Ridge Road, Singapore 119074
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Kwok JSY, Leung AYH, Lie AKW, Lee TL, Lau YL, Chu P, Jones B, Hawkins B, Liang R. Antirecipient helper and cytotoxic T-cell frequencies in bone marrow transplantation. Bone Marrow Transplant 2004; 34:207-13. [PMID: 15195076 DOI: 10.1038/sj.bmt.1704566] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We assayed helper T-lymphocyte precursor frequencies (HTLPf), interferon (IFN)-gamma-producing cell frequencies (IFN-gammaPf) and CTL precursor frequencies (CTLPf) to see if they could predict the severity of acute graft-versus-host disease (aGVHD) and disease relapse after transplantation. In all, 48 bone marrow transplantation (BMT) patients and their HLA-identical sibling (n=29) or matched unrelated donors (MUD) (n=19) were recruited. HTLPf, IFN-gammaPf and CTLPf were measured using a limiting dilution assay (LDA). Patients were followed prospectively to assess the severity of aGVHD and the status of the primary disease after BMT. High (>5 x 10(-6)) HTLPf, CTLPf and IFN-gammaPf were significantly associated with the occurrence and severity of aGVHD in patients who received transplants from HLA-identical sibling. Among patients receiving BMT from MUD, HTLPf and CTLPf, but not IFN-gammaPf, were associated with aGVHD. Five patients had disease relapse post-BMT and the risk was not significantly associated with HTLPf, CTLPf or IFN-gammaPf. Patients with high (>5 x 10(-6)) HTLPf, IFN-gammaPf or CTLPf before BMT are at higher risk of developing aGVHD after transplantation from both matched sibling donors and MUD. Whether these parameters can predict disease relapse would have to be investigated with a larger cohort of patients.
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Affiliation(s)
- J S Y Kwok
- Department of Pathology, Queen Mary Hospital, Hong Kong, China
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Chung BHY, Ha SY, Chan GCF, Chiang A, Lee TL, Ho HK, Lee CY, Luk CW, Lau YL. Klebsiella infection in patients with thalassemia. Clin Infect Dis 2003; 36:575-9. [PMID: 12594637 DOI: 10.1086/367656] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2002] [Accepted: 11/15/2002] [Indexed: 12/29/2022] Open
Abstract
Klebsiella infection has previously been reported in a few patients with transfusion-dependent thalassemia. The incidence and clinical spectrum of this infection in our cohort of patients were reviewed retrospectively. Among 160 patients observed for 12 years, there were 15 episodes of Klebsiella infection that occurred in 12 patients (7.5%), resulting in an incidence of 0.78 infections per 100 patient-years. The clinical spectrum included sinusitis (4 cases), intracranial infection (5 cases), septicemia (4 cases), and abscesses of the liver, lung, kidney, and parotid gland (1 case each). Three patients had recurrent infections involving different sites, 2 (16%) died of fulminant septicemia, and 3 (25%) had significant permanent neurological deficits. The antibiotic susceptibility pattern for the isolates was similar to the pattern for isolates recovered in the community. With regard to predisposing factors, iron overload and liver function derangement were found to be significant on univariate analysis (P=.046 and P=.049, respectively) but insignificant on multivariate analysis. Klebsiella infection was a serious and frequently encountered complication in our patients with transfusion-dependent thalassemia, resulting in high mortality and morbidity rates.
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Affiliation(s)
- B H Y Chung
- Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong SAR, China
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Tan GM, Ti LK, Suresh S, Ho BS, Lee TL. Teaching first-year medical students physiology: does the human patient simulator allow for more effective teaching? Singapore Med J 2002; 43:238-42. [PMID: 12188075] [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: 02/26/2023]
Abstract
BACKGROUND Although the Human Patient Simulator (HPS) is an effective teaching tool in many medical fields, literature supporting its use in the teaching of physiology to medical students is lacking. This study investigated the effectiveness of HPS-based teaching of cardiovascular physiology to first-year medical students. METHODS Two hundred and ten first-year medical students were scheduled to our HPS laboratory with the purpose of demonstrating "physiology in action". Students were divided into groups of 19-25 each, and attended a lecture followed by a HPS session. Using a theatre-type simulator complete with mannequin, anaesthesia machine and monitors (METI, Sarasota FL), the scenarios of hypovolaemia, sepsis, and cardiac failure were run to demonstrate the physiological changes that occur with changes in preload, afterload, and cardiac contractility. Each student was given a true/false test before, and again after the HPS session, followed by a survey of their learning experience. RESULTS There was marked improvement in test scores after the HPS session (82.1% vs. 64.6%, P < 0.001). Most of the students felt that HPS was a better teaching tool (94.5%) and raised more questions (76.5%) than lectures. They wanted more topics to be taught this way (96%), as they could apply and re-enforce textbook knowledge, and visualise real-time changes. However, they felt that their experience could have been enhanced with more time and smaller groups. DISCUSSION HPS is an excellent teaching tool as it stimulates student curiosity and makes knowledge acquisition and understanding easier. It is highly desirable to be incorporated into the teaching of physiology.
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Affiliation(s)
- G M Tan
- Department of Anaesthesia, National University Hospital, Singapore
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To KF, Chan MW, Leung WK, Yu J, Tong JH, Lee TL, Chan FK, Sung JJ. Alterations of frizzled (FzE3) and secreted frizzled related protein (hsFRP) expression in gastric cancer. Life Sci 2001; 70:483-9. [PMID: 11798016 DOI: 10.1016/s0024-3205(01)01422-9] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Wnt signaling pathway is important for development and carcinogenesis. Alterations of this pathway, such as mutations in adenomatous polyposis coli (APC) gene and activation mutations of beta-catenin, would result in stabilization of beta-catenin and subsequent translocation to nucleus where genes are transcribed. Recently, a receptor of Wnt, FzE3 was found to be up-regulated in esophageal carcinoma while a non-receptor antagonist of Wnt, secreted frizzled related protein (hsFRP) was found to be down-regulated in some cancer. These findings suggested that FzE3 is a potential oncogene while hsFRP is a potential tumor suppressor gene. We aimed to investigate whether FzE3 and hsFRP were altered in gastric cancer. Twelve cases of gastric cancer, including 7 cases of intestinal type, 4 cases of diffuse type and I case of mixed type, were studied. FzE3 and hsFRP mRNAs were expressed in most of the paired normal gastric tissues. FzE3 was over-expressed in 9 cases (75%) of gastric carcinoma tissues while hsFRP was down-regulated in 2 cases (16%). Beta-catenin nuclear staining was identified in 3 cases (27%) and cyclin D1 was expressed in 5 cases (41%) of cancer samples. All these cases were associated with either up-regulation of FzE3 or down-regulation of hsFRP. Our results suggested that alterations of FzE3 or hsFRP were frequent in gastric cancer. These provide alternative mechanisms leading to activation of Wnt signaling pathway in gastric carcinogenesis.
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Affiliation(s)
- K F To
- Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Prince of Wales hospital, Shatin, NT, People's Republic of China.
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Jiang MC, Lin TL, Lee TL, Huang HT, Lin CL, Liao CF. IRF-1-mediated CAS expression enhances interferon-gamma-induced apoptosis of HT-29 colon adenocarcinoma cells. Mol Cell Biol Res Commun 2001; 4:353-8. [PMID: 11703094 DOI: 10.1006/mcbr.2001.0303] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The expression of CAS is reported to be upregulated in a variety of human tumor cells, and such expression correlates with the development of tumors. CAS also plays a role in apoptosis. We investigated whether CAS expression affects the susceptibility of tumor cells to IFN-gamma-induced apoptosis. Our data show that IFN-gamma treatment induces CAS expression in HT-29 tumor cells. IFN-gamma-induced gene expression is primarily mediated by the transcriptional factor, IRF-1. Our data show that IRF-1 mediates IFN-gamma-induced CAS expression. Transfection of HT-29 cells with CAS expression vector did not induce apoptosis of cells; nevertheless, CAS overexpression greatly enhanced IFN-gamma-induced apoptosis of cells. CPP32 is regarded as one of the central apoptosis executioner molecules. CAS overexpression enhances IFN-gamma-induced CPP32 expression. These results indicate that tumor cells highly expressing CAS may be more susceptible to apoptosis induced by reagents that are capable of inducing CAS expression. Thus, CAS may be a target for the elimination of tumors.
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Affiliation(s)
- M C Jiang
- Institute of Zoology, Academia Sinica, Taipei 11529, Taiwan, Republic of China
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Liao PH, Lee TL, Yang LC, Yang SH, Chen SL, Chou MY. Adenomatous polyposis coli gene mutation and decreased wild-type p53 protein expression in oral submucous fibrosis: a preliminary investigation. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2001; 92:202-7. [PMID: 11505268 DOI: 10.1067/moe.2001.116816] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The purpose of this study was to identify the adenomatous polyposis coli (APC) tumor suppressor gene mutation and level of wild-type p53 protein expression in patients with oral submucous fibrosis (OSF). STUDY DESIGN Cells from OSF and control subjects were cultured in Dulbecco modified Eagle medium with 10% fetal bovine serum at 37 degrees C. Genomic DNA was extracted from cultured cells and used as a template for polymerase chain reaction amplification of the APC tumor suppressor gene. The presence of wild-type p53 protein in cell lysates of cultured cells was analyzed by Western blot. Data were analyzed by the sign test for nonparametric samples and by analysis of variance. RESULTS The results showed that the APC gene of explant cultured cells from OSF patients (8/8) had a CGA-to-GGA transition mutation at codon 498 that resulted in an Arg-to-Gly missense mutation (P <.01). All (8/8) normal HGF cultures revealed expression of the wild-type APC protein. Cells cultured from 7 of 8 OSF patients were also found to have a single nucleotide deletion at nucleotide 1494 that resulted in creating a stop codon (TGA) at codon 504 (P <.01). This created a premature signal for the endpoint of translation and thus resulted in the generation of a truncated protein product that encodes a polypeptide of 503 amino acid residue. It was found that wild- type p53 protein in human gingival fibroblast cell cultures was significantly higher than in OSF cells (P <.01). CONCLUSION Alterations of the APC and wild-type p53 tumor suppressor genes in OSF may imply a risk for progression to oral cancer.
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Affiliation(s)
- P H Liao
- Departmnent of Dentistry, Chung Shan Medical and Dental College, Taichung, Taiwan, ROC
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Lee TL, Leung WK, Lau JY, Tong JH, Ng EK, Chan FK, Chung SC, Sung JJ, To KF. Inverse association between cyclooxygenase-2 overexpression and microsatellite instability in gastric cancer. Cancer Lett 2001; 168:133-40. [PMID: 11403917 DOI: 10.1016/s0304-3835(01)00527-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This study examined the association between cyclooxygenase-2 (COX-2) overexpression and microsatellite instability (MSI) in gastric cancer. COX-2 expression was assessed by immunohistochemistry and scored in a semi-quantitative manner whereas MSI status was characterized by nine microsatellite markers. The clinicopathological features of cancers including survival data were analyzed. Of the 109 gastric cancers studied, COX-2 overexpression and high level of MSI (MSI-H) was detected in 64.2 and 22.0% cases respectively. Gastric tumors with MSI-H phenotypes had significantly lower level of COX-2 expression levels when compared to MSI-L and MSS tumors (P=0.002). Moreover, COX-2 overexpression was associated with tumor invasion beyond submucosa (P=0.045) and there was a trend favoring better survival in gastric cancers without COX-2 overexpression (P=0.07). The results from this study suggest that gastric cancer with microsatellite instability or COX-2 overexpression present with diverse clinicopathological features.
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Affiliation(s)
- T L Lee
- Department of Anatomical & Cellular Pathology, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
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Leung WK, Yu J, Ng EK, To KF, Ma PK, Lee TL, Go MY, Chung SC, Sung JJ. Concurrent hypermethylation of multiple tumor-related genes in gastric carcinoma and adjacent normal tissues. Cancer 2001. [PMID: 11413518 DOI: 10.1002/1097-0142(20010615)91:] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Transcriptional silencing by CpG-island hypermethylation now is believed to be an important mechanism of tumorigenesis. To date, studies on CpG-island hypermethylation in gastric carcinoma and adjacent normal tissues are few. METHODS The authors examined 5 gastric carcinoma cell lines, 26 frozen gastric carcinoma tissues and their adjacent nontumor area for concurrent CpG-island hypermethylation in 6 tumor-related genes (p15, p16, E-cadherin, GST-pi, hMLH1, and VHL) by methylation-specific polymerase chain reaction. Nontumorous gastric tissues from 10 gastritis patients were used as controls. RESULTS Hypermethylation was not detected in any tissue taken from gastritis patients but was identified in all 5 cell lines and in 24 (92.3%) gastric carcinoma patients. CpG-island methylation in tumor-related genes also was detected in 7 out of the 25 adjacent normal tissues from cancer patients. Hypermethylation of E-cadherin, p15, and p16 were detected more frequently than GST-pi and hMLH1, whereas aberrant methylation of VHL was not detected. Concurrent hypermethylation in 2 or more tumor-related genes was detected in 3 out of the 5 gastric carcinoma cell lines, 22 (84.6%) tumor samples, and 5 (20%) adjacent gastric tissues. Eighteen (69.2%) tumor samples showed hypermethylation in >or= 3 genes. CONCLUSIONS The current study showed that concurrent hypermethylation of multiple tumor-related genes is detected frequently in gastric carcinoma and adjacent normal tissues. Study findings suggested that a mechanism that leads to dysregulation in CpG-island methylation is likely to be involved in the early gastric carcinogenesis process.
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Affiliation(s)
- W K Leung
- Department of Medicine & Therapeutics, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR.
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Abstract
BACKGROUND Transcriptional silencing by CpG-island hypermethylation now is believed to be an important mechanism of tumorigenesis. To date, studies on CpG-island hypermethylation in gastric carcinoma and adjacent normal tissues are few. METHODS The authors examined 5 gastric carcinoma cell lines, 26 frozen gastric carcinoma tissues and their adjacent nontumor area for concurrent CpG-island hypermethylation in 6 tumor-related genes (p15, p16, E-cadherin, GST-pi, hMLH1, and VHL) by methylation-specific polymerase chain reaction. Nontumorous gastric tissues from 10 gastritis patients were used as controls. RESULTS Hypermethylation was not detected in any tissue taken from gastritis patients but was identified in all 5 cell lines and in 24 (92.3%) gastric carcinoma patients. CpG-island methylation in tumor-related genes also was detected in 7 out of the 25 adjacent normal tissues from cancer patients. Hypermethylation of E-cadherin, p15, and p16 were detected more frequently than GST-pi and hMLH1, whereas aberrant methylation of VHL was not detected. Concurrent hypermethylation in 2 or more tumor-related genes was detected in 3 out of the 5 gastric carcinoma cell lines, 22 (84.6%) tumor samples, and 5 (20%) adjacent gastric tissues. Eighteen (69.2%) tumor samples showed hypermethylation in >or= 3 genes. CONCLUSIONS The current study showed that concurrent hypermethylation of multiple tumor-related genes is detected frequently in gastric carcinoma and adjacent normal tissues. Study findings suggested that a mechanism that leads to dysregulation in CpG-island methylation is likely to be involved in the early gastric carcinogenesis process.
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Affiliation(s)
- W K Leung
- Department of Medicine & Therapeutics, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR.
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Leung WK, Yu J, Ng EK, To KF, Ma PK, Lee TL, Go MY, Chung SC, Sung JJ. Concurrent hypermethylation of multiple tumor-related genes in gastric carcinoma and adjacent normal tissues. Cancer 2001. [PMID: 11413518 DOI: 10.1002/1097-0142(20010615)91:12<2294::aid-cncr1261>3.0.co;2-g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Transcriptional silencing by CpG-island hypermethylation now is believed to be an important mechanism of tumorigenesis. To date, studies on CpG-island hypermethylation in gastric carcinoma and adjacent normal tissues are few. METHODS The authors examined 5 gastric carcinoma cell lines, 26 frozen gastric carcinoma tissues and their adjacent nontumor area for concurrent CpG-island hypermethylation in 6 tumor-related genes (p15, p16, E-cadherin, GST-pi, hMLH1, and VHL) by methylation-specific polymerase chain reaction. Nontumorous gastric tissues from 10 gastritis patients were used as controls. RESULTS Hypermethylation was not detected in any tissue taken from gastritis patients but was identified in all 5 cell lines and in 24 (92.3%) gastric carcinoma patients. CpG-island methylation in tumor-related genes also was detected in 7 out of the 25 adjacent normal tissues from cancer patients. Hypermethylation of E-cadherin, p15, and p16 were detected more frequently than GST-pi and hMLH1, whereas aberrant methylation of VHL was not detected. Concurrent hypermethylation in 2 or more tumor-related genes was detected in 3 out of the 5 gastric carcinoma cell lines, 22 (84.6%) tumor samples, and 5 (20%) adjacent gastric tissues. Eighteen (69.2%) tumor samples showed hypermethylation in >or= 3 genes. CONCLUSIONS The current study showed that concurrent hypermethylation of multiple tumor-related genes is detected frequently in gastric carcinoma and adjacent normal tissues. Study findings suggested that a mechanism that leads to dysregulation in CpG-island methylation is likely to be involved in the early gastric carcinogenesis process.
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Affiliation(s)
- W K Leung
- Department of Medicine & Therapeutics, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR.
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Ho HK, Ha SY, Lam CK, Chan GC, Lee TL, Chiang AK, Lau YL. Alloimmunization in Hong Kong southern Chinese transfusion-dependent thalassemia patients. Blood 2001; 97:3999-4000. [PMID: 11405212 DOI: 10.1182/blood.v97.12.3999] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Ko C, Lee TL, Lau PW, Li J, Davis BT, Voyiaziakis E, Allison DB, Chua SC, Huang LS. Two novel quantitative trait loci on mouse chromosomes 6 and 4 independently and synergistically regulate plasma apoB levels. J Lipid Res 2001; 42:844-55. [PMID: 11352992] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023] Open
Abstract
An elevated plasma apolipoprotein B (apoB) level is a strong predictor of atherosclerosis and coronary heart disease. Epidemiologic and family linkage studies have suggested a genetic basis for the wide variations of plasma apoB levels in the general population. Using a human apoB transgenic (HuBTg) mouse model, we have previously shown that hepatic apoB-100 secretion is a major determinant of the high and low plasma human apoB levels in HuBTg mice of the C57BL/6 (B6) and 129/Sv (129) strains, respectively. In the present article, we present the identification of two novel quantitative trait loci (QTL) as major regulators of plasma human apoB levels in the F(2) and N(2) (backcrossed) offspring (n = 572) derived from crosses between the B6 and 129 mouse strains. These loci were designated ApoB regulator genes (Abrg), because the gene products are likely to be involved in the regulation of plasma apoB levels either directly or indirectly. The first locus, designated Abrg1, was mapped to chromosome 6 in 8-week-old male and female mice with a combined logarithm of odds ratio (LOD) score of 14 at the D6Mit55 marker ( approximately 45.9 cM). Abrg1 contributed approximately 35% of the genetic variance. The second locus, designated Abrg2, was mapped to chromosome 4 with an LOD score of 8.6 in 8-week-old male mice but an LOD score of only 2.0 in 8-week-old female mice at the D4Mit27 marker ( approximately 35 cM). Abrg2 contributed approximately 26% of the genetic variance. Epistasis between Abrg1 and Abrg2 was detected and accounted for approximately 12% of the genetic variance. The combination of these two QTL has major effects (>70%) on the regulation of plasma human apoB levels in the tested population. In summary, we have identified two novel loci that have a major role in the regulation of plasma apoB levels and are likely to regulate the secretory pathway of apoB. The human orthologs for the Abrg loci are strong candidates for human disorders characterized by altered plasma apoB levels, such as FCHL and familial hypobetalipoproteinemia.
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Affiliation(s)
- C Ko
- Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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Tong JH, To KF, Ng EK, Lau JY, Lee TL, Lo KW, Leung WK, Tang NL, Chan FK, Sung JJ, Chung SC. Somatic beta-catenin mutation in gastric carcinoma--an infrequent event that is not specific for microsatellite instability. Cancer Lett 2001; 163:125-30. [PMID: 11163116 DOI: 10.1016/s0304-3835(00)00681-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [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: 12/30/2022]
Abstract
We screened 90 cases of gastric carcinoma (GCA) samples for beta-catenin exon 3 mutation and assessed its possible relationship with microsatellite instability (MSI). Three mutations were detected in two samples, including a single mutation in an intestinal type and double mutations in a diffuse type GCA. One of the mutations found in the diffuse type GCA sample was a non-sense mutation at codon 68 (CAG-->TAG). This novel mutation was predicted to disrupt the binding of beta-catenin to alpha-catenin and may be related to the diffuse type morphology. The other two mutations were missense mutations involved or related to the GSK-3beta phosphorylation site, which have been reported previously. No MSI can be demonstrated in the two cases with beta-catenin mutation. Our results suggested that beta-catenin mutation was infrequent in GCA and appeared not specific for MSI.
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Affiliation(s)
- J H Tong
- Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, PR China
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Abstract
BACKGROUND There are conflicting reports on the expression of cyclooxygenase in Helicobacter pylori infection. AIM To evaluate the expression of COX-1 and COX-2 in H. pylori gastritis at messenger RNA (mRNA) and protein levels. METHODS Endoscopic gastric biopsies were obtained from patients with non-ulcer dyspepsia. The levels of COX-1 and COX-2 mRNA were compared between H. pylori-infected and uninfected specimens using reverse transcription-polymerase chain reaction. The immunohistochemical findings were correlated with the cellular localization of cyclooxygenase mRNA using in situ hybridization. RESULTS A total of 40 H. pylori-infected and 40 uninfected specimens were studied. mRNA of COX-2 but not COX-1 was elevated in H. pylori-infected mucosa. COX-1 was localized to the mononuclear inflammatory, endothelial and smooth muscle cells in the lamina propria. COX-2 was barely detectable in uninfected mucosa but was strongly expressed in the foveolar and glandular epithelia in H. pylori gastritis. CONCLUSION Cyclooxygenase-1 is expressed in the mononuclear inflammatory, endothelial and smooth muscle cells in the lamina propria irrespective of the H. pylori status. By contrast, H. pylori induces COX-2 expression in the foveolar and glandular epithelia.
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Affiliation(s)
- F K Chan
- Department of Medicine & Therapeutics, The Chinese University of Hong Kong, Hong Kong.
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Leung WK, To KF, Ng YP, Lee TL, Lau JY, Chan FK, Ng EK, Chung SC, Sung JJ. Association between cyclo-oxygenase-2 overexpression and missense p53 mutations in gastric cancer. Br J Cancer 2001; 84:335-9. [PMID: 11161397 PMCID: PMC2363738 DOI: 10.1054/bjoc.2000.1607] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Wild-type p53 competitively binds to the promoter region of COX-2 in vitro and inhibits its transcription. We examined the association between p53 mutation and COX-2 expression in gastric cancer. COX-2 over-expression was seen in 19 (48.7%) cases. These tumours had more lymph-node metastasis (P = 0.048) and tended to have a poorer survival (P = 0.07). Missense mutations of p53 were detected in 20 (51.3%) patients and had a significantly stronger COX-2 expression than tumours without p53 mutation (P = 0.016). Our results suggest a link between p53 mutation and COX-2 overexpression in gastric cancer.
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Affiliation(s)
- W K Leung
- Departments of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong
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Abstract
BACKGROUND The expression of cyclooxygenase (COX) in human gastric ulcers is unknown. AIM To study the expression and cellular localization of cyclooxygenase in human gastric ulcers. METHODS A total of 38 surgical gastric ulcer specimens were studied; 20 were Helicobacter pylori-positive and 18 were associated with NSAID use. Twenty non-ulcerated, histologically normal gastric specimens were used as controls. The cellular localization of COX-1 and COX-2 were determined by immunohistochemistry and double immunofluorescence. Cyclooxygenase messenger RNA (mRNA) was measured by reverse transcription-polymerase chain reaction and localized by in situ hybridization. RESULTS In control specimens, COX-1 was detected in stromal cells in the lamina propria. There was focal and weak immunostaining for COX-2 in the foveolar epithelium. At the ulcer edge, COX-1 was significantly increased in lamina propria cells whereas COX-2 was strongly expressed in the hyperplastic foveolar epithelium in H. pylori- and non-steroidal anti-inflammatory drugs (NSAID)-associated ulcers. At the ulcer base, there was strong expression of COX-1 and COX-2 in myofibroblasts, macrophages and endothelial cells in the granulation tissue, irrespective of H. pylori status or NSAID use. Messenger RNA of COX-1 and COX-2 were demonstrated by reverse transcription-polymerase chain reaction. Double immunofluorescence and in situ hybridization confirmed the cellular localization of cyclooxygenase at protein and mRNA levels, respectively. CONCLUSION Both COX-1 and COX-2 are up-regulated in human gastric ulcers.
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Affiliation(s)
- K F To
- Department of Anatomical & Cellular Pathology, The Chinese University of Hong Kong, Hong Kong
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Abstract
BACKGROUND Suitable detection methods are needed to support larger studies of microchimerism and the allogeneic exposures that may be etiologically related to it. STUDY DESIGN AND METHODS A twotier PCR strategy for microchimerism detection was developed on the basis of the observation that assay sensitivity for the detection of microchimerism depends on the specificity with which primer pairs recognize sequences unique to the minor population. First, specimens are tested to determine the host HLA class II genotype by using a locus-specific PCR strategy with low sensitivity for microchimerism. Then, a sequence-specific PCR analysis having high sensitivity for detection of microchimerism is applied to detect and quantitate the minor population. Locus-specific, group-specific, and sequence-specific amplification strategies for the detection of distinct minor WBC populations prepared ex vivo were compared. In addition, 39 clinical samples from patients with known transfusion-associated microchimerism and 20 umbilical cord blood (CB) specimens containing maternal WBCs were studied. RESULTS Locus-specific amplification detected 17 (94%) of 18 cases in which microchimerism was present at 10 percent, but only 1 of 51 cases with microchimerism < or = 1 percent. Group-specific amplification detected all 63 cases with minor populations present at > or = 0.10 percent, but only 16 of 21 cases at the 0.01 percent level. Sequence-specific amplification detected 100 percent of cases down to the 0.01 percent level. When applied to clinical samples, locus-specific amplification reliably identified the major population but proved insensitive to low-level minor populations. CONCLUSIONS For the detection of microchimerism, assay sensitivity is a function of amplification strategy. These results suggest a simple approach to population screening for microchimerism: the background population of WBCs is typed by a locus-specific method, while minor population(s) can then be sought by using one or several sequence-specific amplifications.
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Affiliation(s)
- W F Reed
- Blood Centers of the Pacific, Irwin Center, San Francisco, California 94118, USA.
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