1
|
Hu JY, Zhang SY, Yang M, Zhang HF, Kang QY, An W, Han JY. [Research on the establishment of standard limits for perfluorooctanoic acid and perfluorooctane sulfonate in the "Standards for Drinking Water Quality(GB5749-2022)"in China]. Zhonghua Yu Fang Yi Xue Za Zhi 2023; 57:815-822. [PMID: 37357196 DOI: 10.3760/cma.j.cn112150-20221022-01023] [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] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
Perfluorinated compounds, especially Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), are widely detected in water environments in China. Considering the potential health risks of drinking water exposure routes, PFOA and PFOS have been added to the water quality reference index of the newly issued "Standards for Drinking Water Quality (GB5749-2022)", with limit values of 40 and 80 ng/L, respectively. This study analyzed and discussed the relevant technical contents for determining the limits of the hygiene standard, including the environmental existence level and exposure status of PFOA and PFOS, health effects, derivation of safety reference values, and determination of hygiene standard limits. It also proposed prospects for the future direction of formulating drinking water standards.
Collapse
Affiliation(s)
- J Y Hu
- College of Urban and Environment Science, Peking University, Beijing 100871, China
| | - S Y Zhang
- College of Urban and Environment Science, Peking University, Beijing 100871, China
| | - M Yang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - H F Zhang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Q Y Kang
- College of Urban and Environment Science, Peking University, Beijing 100871, China
| | - W An
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - J Y Han
- China CDC Key Laboratory of Environment and Population Health/National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China
| |
Collapse
|
2
|
Gao SH, An W, Yang M, Ye BX, Zhang L. [Research on the determination of the limit value of perchlorate in the "Standards for Drinking Water Quality(GB5749-2022)" in China]. Zhonghua Yu Fang Yi Xue Za Zhi 2023; 57:823-825. [PMID: 37357197 DOI: 10.3760/cma.j.cn112150-20221020-01018] [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] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
Perchlorate is an environmental pollutant that has been a focus of attention in recent years. It has been detected in many environmental water bodies and drinking water in China, with a high level of presence in some areas of the Yangtze River Basin. The human body may ingest perchlorate through exposure pathways such as drinking water and food, and its main health effect is to affect the thyroid's absorption of iodine. The "Standards for Drinking Water Quality" (GB5749-2022) includes perchlorate as an expanded indicator of water quality, with a limit value of 0.07 mg/L. This article analyzes the technical content related to the determination of hygiene standard limits for perchlorate in drinking water, including the environmental presence level and exposure status of perchlorate, main health effects, derivation of safety reference values, and determination of hygiene standard limits.
Collapse
Affiliation(s)
- S H Gao
- China CDC Key Laboratory of Environment and Population Health/National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China
| | - W An
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - M Yang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - B X Ye
- China CDC Key Laboratory of Environment and Population Health/National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China
| | - L Zhang
- China CDC Key Laboratory of Environment and Population Health/National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China
| |
Collapse
|
3
|
Li L, Xie P, Bi CS, Wang TY, Wang N, Lin WW, Zhang C, An W, Zhan YT. [Effect of CKIP-1 on hepatocyte apoptosis in nonalcoholic fatty liver disease]. Zhonghua Nei Ke Za Zhi 2023; 62:43-48. [PMID: 36631036 DOI: 10.3760/cma.j.cn112138-20220131-00088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Objective: To explore the effect and underlying mechanism of casein kinase 2 interacting protein-1 (CKIP-1) on hepatocyte apoptosis in nonalcoholic fatty liver disease (NAFLD). Methods: Experimental study. An NAFLD cell model was established by inducing human hepatoma cell line, HepG2 cells, with oleic acid (OA). Flag-CKIP-1 expression vector and shRNA-CKIP-1 were transfected into HepG2 cells. Flow cytometry was used to detect the effect of CKIP-1 on the activity and apoptosis of NAFLD hepatocytes. The levels of apoptosis-related proteins were detected by Western blot. CKIP-1 knockout mice in C57BL/6 back-ground were fed with either standard or high-fat diet for 8 weeks. Apoptosis-related signal proteins in NAFLD hepatocytes were detected by immunohistochemistry. Results: After CKIP-1 was transfected into HepG2 cells, the degree of OA induced cell liposis was significantly reduced (P<0.05). Annexin V-FITC/PI flow cytometry showed that CKIP-1 reduced the apoptosis of steatotic hepatocytes. Overexpression of CKIP-1 could significantly inhibit the expression of caspase-3 and caspase-9 and increase the expression of Bcl-2/Bax (P<0.05). Knockdown of CKIP-1 could increase the expression of caspase-3 and caspase-9 (P<0.05). CKIP-1 knockout could further increase the expression of caspase-3 and caspase-9 in NAFLD mice (P<0.01,P<0.05), and further decrease the expression of Bcl-2/Bax (P<0.05). Conclusion: CKIP-1 inhibited the apoptosis of steatotic hepatocytes by up-regulating the expression of apoptosis inhibitor gene, Bcl-2/Bax, and affecting the proteases, caspase-3 and caspase-9.
Collapse
Affiliation(s)
- L Li
- Department of Gastroenterology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - P Xie
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing 100069, China
| | - C S Bi
- Department of Gastroenterology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - T Y Wang
- Department of Gastroenterology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - N Wang
- Department of Gastroenterology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - W W Lin
- Department of Gastroenterology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - C Zhang
- Department of Gastroenterology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - W An
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing 100069, China
| | - Y T Zhan
- Department of Gastroenterology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| |
Collapse
|
4
|
An W, Zhang Y, Lai H, Zhang Y, Zhang H, Zhao G, Liu M, Li Y, Lin X, Cao S. Alpinia katsumadai Hayata induces growth inhibition and autophagy‑related apoptosis by regulating the AMPK and Akt/mTOR/p70S6K signaling pathways in cancer cells. Oncol Rep 2022; 48:142. [PMID: 35730618 PMCID: PMC9245070 DOI: 10.3892/or.2022.8353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 05/17/2022] [Indexed: 12/04/2022] Open
Abstract
Alpinia katsumadai Hayata (AKH), a widely used traditional Chinese medicine, exerts various biological functions, including anti-inflammatory, antioxidant, anti-microbial and anti-asthmatic effects. However, studies on its anticancer activity and associated mechanisms are limited. The present study investigated the effects of ethanol extract from AKH on the viability of various human cancer and normal liver LX-2 cells using Cell Counting Kit-8 assay. Apoptosis was detected by Hoechst 33342/PI staining and Annexin-V-FITC/PI double staining. Autophagy was examined by Ad-GFP-LC3B transfection. The association between AKH-induced autophagy and apoptosis was investigated by pre-treatment of the cells with the autophagy inhibitors, 3-methyladenine (3MA) and bafilomycin A1 (Baf-A1), followed by treatment with AKH. The expression levels of cleaved poly(ADP-ribose) polymerase (PARP), caspase-8, caspase-3, caspase-9, phosphorylated (p-)AMP-activated protein kinase (AMPK), Akt, mTOR and p70S6K were examined using western blot analysis. The in vivo antitumor activity of AKH was investigated in nude mice bearing A549 lung cancer xenografts. The components of AKH were detected by liquid chromatography mass spectrometry-ion trap-time-of-flight mass spectrometry. The results revealed that AKH significantly inhibited the proliferation of various cancer cells with the half maximal inhibitory concentration (IC50) values of 203–284 µg/ml; however, its inhibitory effect was much less prominent against normal liver LX-2 cells with an IC50 value of 395 µg/ml. AKH markedly induced apoptosis and autophagy, and upregulated the protein expression of cleaved-caspase-3, caspase-8, caspase-9 and cleaved PARP in a concentration-dependent manner. Of note, the autophagy inhibitors (3MA and Baf-A1) significantly attenuated its pro-apoptotic effects on human pancreatic cancer Panc-28 and lung cancer A549 cells. Furthermore, AKH significantly increased the levels of p-AMPK, and decreased those of p-Akt, p-mTOR and p-p70S6K in Panc-28 and A549 cells. AKH markedly inhibited the growth of A549 tumor xenografts in vivo. In addition, a total of nine compounds were detected from AKH. The present study demonstrates that AKH markedly inhibits the growth and induces autophagy-related apoptosis in cancer cells by regulating the AMPK and Akt/mTOR/p70S6K signaling pathways. AKH and/or its active fractions may thus have potential to be developed as novel anticancer agents for clinical use.
Collapse
Affiliation(s)
- Weixiao An
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Yuxi Zhang
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Honglin Lai
- Department of Pharmacy, Affiliated Hospital of Traditional Chinese Medicine, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Yangyang Zhang
- Department of Pharmacy, Dongying Hospital of Traditional Chinese Medicine, Dongying, Shandong 257055, P.R. China
| | - Hongmei Zhang
- Rizhao Hospital of Traditional Chinese Medicine, Rizhao, Shandong 276801, P.R. China
| | - Ge Zhao
- Department of Pharmacology, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China
| | - Minghua Liu
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Yang Li
- Department of International Trade, School of International Traded and Economics, University of International Business and Economics, Beijing 100029, P.R. China
| | - Xiukun Lin
- Delisi Group Co. Ltd., Zhucheng, Shandong 262200, P.R. China
| | - Shousong Cao
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| |
Collapse
|
5
|
Chang L, zhang L, An W, wan Y, cai Y, Lan Y, Ruan M, liu X, Zou Y, Zhu X. P814: CLINICAL CHARACTERISTICS AND GENE MUTATION ANALYSIS OF 148 CHILDREN WITH FANCONI ANEMIA IN CHINA. Hemasphere 2022. [PMCID: PMC9431339 DOI: 10.1097/01.hs9.0000846140.75399.5d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
6
|
Zhao G, Tong Y, Luan F, Zhu W, Zhan C, Qin T, An W, Zeng N. Alpinetin: A Review of Its Pharmacology and Pharmacokinetics. Front Pharmacol 2022; 13:814370. [PMID: 35185569 PMCID: PMC8854656 DOI: 10.3389/fphar.2022.814370] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 01/12/2022] [Indexed: 12/11/2022] Open
Abstract
Flavonoids isolated from medicinal herbs have been utilized as valuable health-care agents due to their virous biological applications. Alpinetin is a natural flavonoid that emerges in many widely used medicinal plants, and has been frequently applied in Chinese patent drugs. Accumulated evidence has demonstrated that alpinetin possesses a broad range of pharmacological activities such as antitumor, antiinflammation, hepatoprotective, cardiovascular protective, lung protective, antibacterial, antiviral, neuroprotective, and other properties through regulating multiple signaling pathways with low systemic toxicity. However, pharmacokinetic studies have documented that alpinetin may have poor oral bioavailability correlated to its extensive glucuronidation. Currently, the reported pharmacological properties and pharmacokinetics profiles of alpinetin are rare to be scientifically reviewed. In this article, we aimed to highlight the mechanisms of action of alpinetin in various diseases to strongly support its curative potentials for prospective clinical applications. We also summarized the pharmacokinetics properties and proposed some viable strategies to convey an appreciable reference for future advances of alpinetin in drug development.
Collapse
|
7
|
San Miguel Claveria P, Adli E, Amorim LD, An W, Clayton CE, Corde S, Gessner S, Hogan MJ, Joshi C, Kononenko O, Litos M, Lu W, Marsh KA, Mori WB, O'Shea B, Raj G, Storey D, Vafaei-Najafabadi N, White G, Xu X, Yakimenko V. Betatron radiation and emittance growth in plasma wakefield accelerators. Philos Trans A Math Phys Eng Sci 2019; 377:20180173. [PMID: 31230577 PMCID: PMC6602914 DOI: 10.1098/rsta.2018.0173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 03/20/2019] [Indexed: 06/09/2023]
Abstract
Beam-driven plasma wakefield acceleration (PWFA) has demonstrated significant progress during the past two decades of research. The new Facility for Advanced Accelerator Experimental Tests (FACET) II, currently under construction, will provide 10 GeV electron beams with unprecedented parameters for the next generation of PWFA experiments. In the context of the FACET II facility, we present simulation results on expected betatron radiation and its potential application to diagnose emittance preservation and hosing instability in the upcoming PWFA experiments. This article is part of the Theo Murphy meeting issue 'Directions in particle beam-driven plasma wakefield acceleration'.
Collapse
Affiliation(s)
- P. San Miguel Claveria
- LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, 91762 Palaiseau, France
| | - E. Adli
- University of Oslo, NO-0316 Oslo, Norway
| | - L. D. Amorim
- Stonybrook University, Stony Brook, NY 11794, USA
| | - W. An
- University of California Los Angeles, Los Angeles, CA 90095, USA
| | - C. E. Clayton
- University of California Los Angeles, Los Angeles, CA 90095, USA
| | - S. Corde
- LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, 91762 Palaiseau, France
| | | | - M. J. Hogan
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - C. Joshi
- University of California Los Angeles, Los Angeles, CA 90095, USA
| | - O. Kononenko
- LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, 91762 Palaiseau, France
| | - M. Litos
- University of Colorado Boulder, Boulder, CO 80309, USA
| | - W. Lu
- Tsinghua University, Beijing 10084, People's Republic of China
| | - K. A. Marsh
- University of California Los Angeles, Los Angeles, CA 90095, USA
| | - W. B. Mori
- University of California Los Angeles, Los Angeles, CA 90095, USA
| | - B. O'Shea
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - G. Raj
- LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, 91762 Palaiseau, France
| | - D. Storey
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | | | - G. White
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Xinlu Xu
- University of California Los Angeles, Los Angeles, CA 90095, USA
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - V. Yakimenko
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| |
Collapse
|
8
|
Vafaei-Najafabadi N, Amorim LD, Adli E, An W, Clarke CI, Clayton CE, Corde S, Gessner S, Green SZ, Hogan MJ, Joshi C, Kononenko O, Lindstrøm CA, Litos M, Lu W, Marsh KA, Mori WB, San Miguel Claveria P, O'Shea B, Raj G, Storey D, White G, Xu X, Yakimenko V. Producing multi-coloured bunches through beam-induced ionization injection in plasma wakefield accelerator. Philos Trans A Math Phys Eng Sci 2019; 377:20180184. [PMID: 31230576 PMCID: PMC6602915 DOI: 10.1098/rsta.2018.0184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/20/2019] [Indexed: 06/09/2023]
Abstract
This paper discusses the properties of electron beams formed in plasma wakefield accelerators through ionization injection. In particular, the potential for generating a beam composed of co-located multi-colour beamlets is demonstrated in the case where the ionization is initiated by the evolving charge field of the drive beam itself. The physics of the processes of ionization and injection are explored through OSIRIS simulations. Experimental evidence showing similar features are presented from the data obtained in the E217 experiment at the FACET facility of the SLAC National Laboratory. This article is part of the Theo Murphy meeting issue 'Directions in particle beam-driven plasma wakefield acceleration'.
Collapse
Affiliation(s)
| | - L. D. Amorim
- Stony Brook University, Stony Brook, NY 11794, USA
| | - E. Adli
- University of Oslo, Oslo 0316, Norway
| | - W. An
- University of California Los Angeles, Los Angeles, CA 90095, USA
| | - C. I. Clarke
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - C. E. Clayton
- University of California Los Angeles, Los Angeles, CA 90095, USA
| | - S. Corde
- LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Université Paris-Saclay, Palaiseau 91762, France
| | | | - S. Z. Green
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - M. J. Hogan
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - C. Joshi
- University of California Los Angeles, Los Angeles, CA 90095, USA
| | - O. Kononenko
- LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Université Paris-Saclay, Palaiseau 91762, France
| | | | - M. Litos
- University of Colorado Boulder, Boulder, CO 80309, USA
| | - W. Lu
- Tsinghua University, Beijing 10084, People's Republic of China
| | - K. A. Marsh
- University of California Los Angeles, Los Angeles, CA 90095, USA
| | - W. B. Mori
- University of California Los Angeles, Los Angeles, CA 90095, USA
| | - P. San Miguel Claveria
- LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Université Paris-Saclay, Palaiseau 91762, France
| | - B. O'Shea
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - G. Raj
- LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Université Paris-Saclay, Palaiseau 91762, France
| | - D. Storey
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - G. White
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Xinlu Xu
- University of California Los Angeles, Los Angeles, CA 90095, USA
| | - V. Yakimenko
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| |
Collapse
|
9
|
An W, Lai H, Zhang Y, Liu M, Lin X, Cao S. Apoptotic Pathway as the Therapeutic Target for Anticancer Traditional Chinese Medicines. Front Pharmacol 2019; 10:758. [PMID: 31354479 PMCID: PMC6639427 DOI: 10.3389/fphar.2019.00758] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 06/11/2019] [Indexed: 12/12/2022] Open
Abstract
Cancer is a leading cause of morbidity and mortality worldwide. Apoptosis is a process of programmed cell death and it plays a vital role in human development and tissue homeostasis. Mounting evidence indicates that apoptosis is closely related to the survival of cancer and it has emerged as a key target for the discovery and development of novel anticancer drugs. Various studies indicate that targeting the apoptotic signaling pathway by anticancer drugs is an important mechanism in cancer therapy. Therefore, numerous novel anticancer agents have been discovered and developed from traditional Chinese medicines (TCMs) by targeting the cellular apoptotic pathway of cancer cells and shown clinically beneficial effects in cancer therapy. This review aims to provide a comprehensive discussion for the role, pharmacology, related biology, and possible mechanism(s) of a number of important anticancer TCMs and their derivatives mainly targeting the cellular apoptotic pathway. It may have important clinical implications in cancer therapy.
Collapse
Affiliation(s)
- Weixiao An
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China.,Department of Pharmacy, Nanchong Central Hospital, Nanchong, China
| | - Honglin Lai
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China.,Department of Pharmacy, Affliated Hospital of Traditional Chinese Medicine, Southwest Medical University, Luzhou, China
| | - Yangyang Zhang
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Minghua Liu
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Xiukun Lin
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Shousong Cao
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China
| |
Collapse
|
10
|
Liu M, Zhao G, Zhang D, An W, Lai H, Li X, Cao S, Lin X. Active fraction of clove induces apoptosis via PI3K/Akt/mTOR-mediated autophagy in human colorectal cancer HCT-116 cells. Int J Oncol 2018; 53:1363-1373. [DOI: 10.3892/ijo.2018.4465] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 06/14/2018] [Indexed: 12/09/2022] Open
Affiliation(s)
- Minghua Liu
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Ge Zhao
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Dan Zhang
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Weixiao An
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Honglin Lai
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Xiaofang Li
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Shousong Cao
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Xiukun Lin
- Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| |
Collapse
|
11
|
Zhang Y, Lai H, An W, Cao S, Lin X. Abstract 1508: Cloning, expression and purification of Cionasavignyi polypeptide CS5931 and its antitumor activity. Cancer Res 2018. [DOI: 10.1158/1538-7445.am2018-1508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Previous study in our laboratory has shown that a novel polypeptide CS5931 (molecular weight 5931 Da) derived from Ciona savignyi possesses potent cytotoxicity against a variety of human cancer cells including cervical carcinoma Hela cells, colorectal carcinoma HCT-116 and RKO cells, lung carcinoma A549 cells, and leukemia HL60 cells ,with IC50 values of 4.17, 2.50, 5.54, 4.69 and 4.98uM,respectively. This result suggested that HCT116 cells are the most sensitive to the treatment of CS5931. We also found that CS5931 markedly induced apoptosis in a dose-dependent manner in HCT116 cells by Annexin V-FITC/PI double staining analysis. However, its content in Ciona savignyi is very low thus developing a novel method for increase of the production of the polypeptide is promising. GRN polypeptides typically consist of 56-58 amino acids with six disulfide bonds and four beta-sheets to make the GRN polypeptide structurally compact and complex so large-scale preparation of natural polypeptide CS5931 is very difficult. Therefore, recombinant expression of CS5931 by genetic engineering is one of the effective ways to solve this problem. In the present study, we cloned a full length cDNA of CS5931 precursor by rapid amplification of cDNA ends (RACE) and obtained the amino acid sequence of CS5931. We further made the polypeptide expression with high efficiency in E. coli. The expressed protein was purified through affinity chromatography. The gene fragment coding CS5931 was successfully cloned and then linked into prokaryotic expression carrier pET28a(+) and pPICZαa, respectively. Two expression vectors pET28a(+)-CS5931 and pPICZαa-CS5931 were transformed into E. coli and Pichia pastoris, respectively. Then recombinant polypeptide CS5931 were successfully induced with high expression . To investigate the expression and anticancer effect of polypeptide CS5931 in different vectors and strains, we purified the expressed product developed suitable methods for CS5931 great expression while maintaining its potent anticancer activity and identified the role of CS5931 target proteins. Moreover, the purified polypeptide native CS5931 and recombinant CS5931 equally display great antitumor activity against HT29 cells. Our studies indicate that we have successfully cloned, expressed and purified Ciona savignyi polypeptide CS5931 and demonstrated its potent antitumor activity against colorectal cancer cells. Therefore, CS5931 may be developed as a novel anticancer agent in the treatment of colorectal cancer clinically.
Citation Format: Yangyang Zhang, Honglin Lai, Weixiao An, Shousong Cao, Xiukun Lin. Cloning, expression and purification of Cionasavignyi polypeptide CS5931 and its antitumor activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1508.
Collapse
Affiliation(s)
| | | | - Weixiao An
- Southwest Medical University, Luzhou, China
| | | | - Xiukun Lin
- Southwest Medical University, Luzhou, China
| |
Collapse
|
12
|
An W, Lai H, Zhang Y, Lin X, Cao S. Abstract 3979: Active components of Alpinia katsumadai-induced cell apoptosis and autophagy in human pancreatic cancer cells. Cancer Res 2018. [DOI: 10.1158/1538-7445.am2018-3979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Alpinia katsumadai, as a traditional Chinese medicine, exhibited potent anti-oxidative and anticancer effects. Studies have shown that the effect of the active components of Alpinia katsumadai (ACAK) on anticancer is via apoptosis or autophagy in colorectal and glioblastoma cancer cells. However, the effects of ACAK on anticancer effect and inducation of apoptosis and autophagy in pancreatic cancer cells are still unknown. Therefore, we investigated the effects of ACAK on cytotocixity, apoptosis and autophagy as well as associated mechanisms in pancreatic cancers Panc-1 and Panc-28 cells. We found that ACAK showed greater inhibitory effects on the proliferation of Panc-1 and Panc-28 cells in a dose- and time-dependent manners (IC50 0.1692 and 0.1554mg/ml, respectively) compared to a variety of other cancer cells including breast cancer MDA-MB-468 cells, melamoma A875 cells, lung cancer A549 cells, colon cancer HCT-116 cells, and glioblastoma cancer U87 cells (IC50 0.2302, 0.2586, 0.2642, 0.3006, and 0.4298, respectively) by CCK-8 assay. Furthermore, ACAK induced cell apoptosis in pancreatic cancer Panc-1 and Panc-28 cells in a dose- dependent manner by Hochest 33342-PI and AnnexinV-PI dual staining analysis. Moreover, the expression levels of apoptosis related proteins casepase 3, casepase 9, and PARP were significantly up-regulated by Western blotting analysis. The study of cell autophagy was dectected by mRFP -GFP-LC3 adenovirus and western-blotting. and the results showed that the expression levels of autophagy-related protein beclin-1 and LC3-II were significanlt up-regulated by mRFP-GFP-LC3 adenovirus and western-blotting analysis. Our findings demonstrated that ACAK had greater cytotoxicity than a variety of other cancer cells by inducing apoptosis and autophagy in pancreatic cancer Panc-1 and Panc-28 cells. Therefore, ACAK may be developed as a novel anticancer agent for the treatment of pancreatic cancer clinically.
Citation Format: Weixiao An, Honglin Lai, Yangyyang Zhang, Xiukun Lin, Shousong Cao. Active components of Alpinia katsumadai-induced cell apoptosis and autophagy in human pancreatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3979.
Collapse
Affiliation(s)
- Weixiao An
- Southwest Medical University, Luzhou City,Sichuan Province, China
| | - Honglin Lai
- Southwest Medical University, Luzhou City,Sichuan Province, China
| | - Yangyyang Zhang
- Southwest Medical University, Luzhou City,Sichuan Province, China
| | - Xiukun Lin
- Southwest Medical University, Luzhou City,Sichuan Province, China
| | - Shousong Cao
- Southwest Medical University, Luzhou City,Sichuan Province, China
| |
Collapse
|
13
|
Abstract
Abstract
Recent evidence demonstrates that microRNAs (miRNAs) are associated with cancer development and have the potential to be used as anticancer agents. However, the application of miRNAs as clinical cancer drugs has been limited due to their unstability at room temperature. Moreover, miRNAs are negatively charged and excluded by cytomembrane, which has the same polarity. Therefore, miRNAs are difficult to enter cancer cells to exhibit their anticancer effects. In order to solve the problem, we changed the polarity of miRNA let-7a, a member of the second identified miRNA let-7 families, by coating with a bioavailable polymer, polyethylenimine (PEI) using nanotechnology, to alter the charge of miRNA let-7a for positive charge so easily connecting with the anionic residues of cancer cell surfaces. Therefore, miRNA let-7a could easily entered cells through endocytosis. In addition, we performed formaldehyde denaturing SDS-PAGE analysis to determine the stability of miRNA let-7a, and we found the stability of miRNA let-7a has been significantly increased due to microspheres formation. MiRNA let-7a microspheres have showed potent cytotoxicity against a variety of cancer cells including HCT-116, A875, A549, and 4T1 cells with the IC50 as 31.77, 54.34, 44.35, 43.18 pmol/l, respectively by CCK-8 kit analysis. We also found that miRNA let-7a microspheres are able to induce cell apoptosis by promoting the expression of apoptosis-related genes Caspase 3, Caspase 9 and PARP in HCT-116 and A875 cells. Our findings may provide that miRNA let-7a microspheres may be developed as a novel anticancer agents in cancer therapy.
Citation Format: Honglin Lai, Weixiao An, Yangyang Zhang, Xiukun Lin, Shousong Cao. Preparation and mechanism of polyethyleneimine coated miRNA let-7a microspheres [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4427.
Collapse
Affiliation(s)
| | - Weixiao An
- Southwest Medical University, Luzhou, China
| | | | - Xiukun Lin
- Southwest Medical University, Luzhou, China
| | | |
Collapse
|
14
|
Lindstrøm CA, Adli E, Allen JM, An W, Beekman C, Clarke CI, Clayton CE, Corde S, Doche A, Frederico J, Gessner SJ, Green SZ, Hogan MJ, Joshi C, Litos M, Lu W, Marsh KA, Mori WB, O'Shea BD, Vafaei-Najafabadi N, Yakimenko V. Measurement of Transverse Wakefields Induced by a Misaligned Positron Bunch in a Hollow Channel Plasma Accelerator. Phys Rev Lett 2018; 120:124802. [PMID: 29694092 DOI: 10.1103/physrevlett.120.124802] [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] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Indexed: 06/08/2023]
Abstract
Hollow channel plasma wakefield acceleration is a proposed method to provide high acceleration gradients for electrons and positrons alike: a key to future lepton colliders. However, beams which are misaligned from the channel axis induce strong transverse wakefields, deflecting beams and reducing the collider luminosity. This undesirable consequence sets a tight constraint on the alignment accuracy of the beam propagating through the channel. Direct measurements of beam misalignment-induced transverse wakefields are therefore essential for designing mitigation strategies. We present the first quantitative measurements of transverse wakefields in a hollow plasma channel, induced by an off-axis 20 GeV positron bunch, and measured with another 20 GeV lower charge trailing positron probe bunch. The measurements are largely consistent with theory.
Collapse
Affiliation(s)
- C A Lindstrøm
- Department of Physics, University of Oslo, 0316 Oslo, Norway
| | - E Adli
- Department of Physics, University of Oslo, 0316 Oslo, Norway
| | - J M Allen
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - W An
- Department of Electrical Engineering, University of California-Los Angeles, Los Angeles, California 90095, USA
| | - C Beekman
- LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Université Paris-Saclay, 91762 Palaiseau, France
| | - C I Clarke
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - C E Clayton
- Department of Electrical Engineering, University of California-Los Angeles, Los Angeles, California 90095, USA
| | - S Corde
- LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Université Paris-Saclay, 91762 Palaiseau, France
| | - A Doche
- LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Université Paris-Saclay, 91762 Palaiseau, France
| | - J Frederico
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - S J Gessner
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - S Z Green
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - M J Hogan
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - C Joshi
- Department of Electrical Engineering, University of California-Los Angeles, Los Angeles, California 90095, USA
| | - M Litos
- Department of Physics, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - W Lu
- IFSA Collaborative Innovation Center, Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - K A Marsh
- Department of Electrical Engineering, University of California-Los Angeles, Los Angeles, California 90095, USA
| | - W B Mori
- Department of Physics and Astronomy, University of California-Los Angeles, Los Angeles, California 90095, USA
| | - B D O'Shea
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - N Vafaei-Najafabadi
- Department of Electrical Engineering, University of California-Los Angeles, Los Angeles, California 90095, USA
| | - V Yakimenko
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| |
Collapse
|
15
|
Doche A, Beekman C, Corde S, Allen JM, Clarke CI, Frederico J, Gessner SJ, Green SZ, Hogan MJ, O'Shea B, Yakimenko V, An W, Clayton CE, Joshi C, Marsh KA, Mori WB, Vafaei-Najafabadi N, Litos MD, Adli E, Lindstrøm CA, Lu W. Acceleration of a trailing positron bunch in a plasma wakefield accelerator. Sci Rep 2017; 7:14180. [PMID: 29079817 PMCID: PMC5660186 DOI: 10.1038/s41598-017-14524-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 10/11/2017] [Indexed: 11/21/2022] Open
Abstract
High gradients of energy gain and high energy efficiency are necessary parameters for compact, cost-efficient and high-energy particle colliders. Plasma Wakefield Accelerators (PWFA) offer both, making them attractive candidates for next-generation colliders. In these devices, a charge-density plasma wave is excited by an ultra-relativistic bunch of charged particles (the drive bunch). The energy in the wave can be extracted by a second bunch (the trailing bunch), as this bunch propagates in the wake of the drive bunch. While a trailing electron bunch was accelerated in a plasma with more than a gigaelectronvolt of energy gain, accelerating a trailing positron bunch in a plasma is much more challenging as the plasma response can be asymmetric for positrons and electrons. We report the demonstration of the energy gain by a distinct trailing positron bunch in a plasma wakefield accelerator, spanning nonlinear to quasi-linear regimes, and unveil the beam loading process underlying the accelerator energy efficiency. A positron bunch is used to drive the plasma wake in the experiment, though the quasi-linear wake structure could as easily be formed by an electron bunch or a laser driver. The results thus mark the first acceleration of a distinct positron bunch in plasma-based particle accelerators.
Collapse
Affiliation(s)
- A Doche
- LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Universite Paris-Saclay, 91762, Palaiseau, France.
| | - C Beekman
- LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Universite Paris-Saclay, 91762, Palaiseau, France
| | - S Corde
- LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Universite Paris-Saclay, 91762, Palaiseau, France.
| | - J M Allen
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - C I Clarke
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - J Frederico
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - S J Gessner
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - S Z Green
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - M J Hogan
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - B O'Shea
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - V Yakimenko
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - W An
- University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - C E Clayton
- University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - C Joshi
- University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - K A Marsh
- University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - W B Mori
- University of California Los Angeles, Los Angeles, CA, 90095, USA
| | | | - M D Litos
- University of Colorado Boulder, Boulder, CO, 80309, USA
| | - E Adli
- Department of Physics, University of Oslo, 0316, Oslo, Norway
| | - C A Lindstrøm
- Department of Physics, University of Oslo, 0316, Oslo, Norway
| | - W Lu
- Department of Engineering Physics, Tsinghua University, Beijing, 10084, China
| |
Collapse
|
16
|
Cole B, Bhatt P, Kwok I, Bailey V, An W, Bresilla C, Chin J, Krouse M. WS18.1 Combination FDL169/FDL176 is superior to tezacaftor/ivacaftor. J Cyst Fibros 2017. [DOI: 10.1016/s1569-1993(17)30255-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
17
|
An W, Wedner H. P021 Agep and dress in an atypical presentation of allopurinol hypersensitivity. Ann Allergy Asthma Immunol 2016. [DOI: 10.1016/j.anai.2016.09.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
18
|
Li CL, Du XY, Gao J, Wang C, Guo HG, Dai FW, Sa XY, An W, Chen ZW. Phylogenetic analysis of the Mongolian gerbil (Meriones unguiculatus) from China based on mitochondrial genome. Genet Mol Res 2016; 15:gmr7703. [PMID: 27706720 DOI: 10.4238/gmr.15037703] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Meriones unguiculatus (Gerbillinae, Rodentia) is widely used as an animal model of human disease. Here, we provide the first report of the complete mitochondrial genome sequence of M. unguiculatus (GenBank accession Nos. KF425526 and NC_023263). The sequence contained the conserved vertebrate pattern of 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and 1 major noncoding region. We identified one extended termination-associated sequence and one conserved sequence block in the non-coding region. The putative origin of replication for the light strand (OL) was 35 bp long. The OL stem and adjacent sequences were highly conserved, but the loop region differed from those of other rodent species. Base composition and codon usage of the 13 protein-coding genes in M. unguiculatus were compared with those of 23 rodent species with previously sequenced mitochondrial genomes. An A+T content of 63.0% was present in M. unguiculatus; this is similar to the Murinae average (62.4 ± 0.8%) and falls between the average for Mus musculus (63.1 ± 0.1%) and Rattus sp (61.7 ± 0.4%). The AT and GC skew values of M. unguiculatus were 0.035 and -0.28, respectively, similar to those of Cricetinae species (0.057 ± 0.05 and -0.31 ± 0.05). The codon families exhibited similar abundance in all 24 species. Analysis of phylogenetic relationships with 23 other rodent species using neighbor-joining and maximum likelihood protocols and the 12 protein-coding regions on the H strand showed that M. unguiculatus should be classified as genus Meriones, sub-family Gerbillinae, family Muridae.
Collapse
Affiliation(s)
- C L Li
- School of Basic Medical Science, Capital Medical University, Beijing, China
| | - X Y Du
- School of Basic Medical Science, Capital Medical University, Beijing, China
| | - J Gao
- Shanghai Academy of Agriculture, Shanghai, China
| | - C Wang
- School of Basic Medical Science, Capital Medical University, Beijing, China
| | - H G Guo
- Zhejiang Center of Laboratory Animals, Zhejiang Academy of Medical Science, Hangzhou, China
| | - F W Dai
- Zhejiang Center of Laboratory Animals, Zhejiang Academy of Medical Science, Hangzhou, China
| | - X Y Sa
- Zhejiang Center of Laboratory Animals, Zhejiang Academy of Medical Science, Hangzhou, China
| | - W An
- School of Basic Medical Science, Capital Medical University, Beijing, China
| | - Z W Chen
- School of Basic Medical Science, Capital Medical University, Beijing, China
| |
Collapse
|
19
|
Clayton CE, Adli E, Allen J, An W, Clarke CI, Corde S, Frederico J, Gessner S, Green SZ, Hogan MJ, Joshi C, Litos M, Lu W, Marsh KA, Mori WB, Vafaei-Najafabadi N, Xu X, Yakimenko V. Self-mapping the longitudinal field structure of a nonlinear plasma accelerator cavity. Nat Commun 2016; 7:12483. [PMID: 27527569 PMCID: PMC4990705 DOI: 10.1038/ncomms12483] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Accepted: 07/05/2016] [Indexed: 11/09/2022] Open
Abstract
The preservation of emittance of the accelerating beam is the next challenge for plasma-based accelerators envisioned for future light sources and colliders. The field structure of a highly nonlinear plasma wake is potentially suitable for this purpose but has not been yet measured. Here we show that the longitudinal variation of the fields in a nonlinear plasma wakefield accelerator cavity produced by a relativistic electron bunch can be mapped using the bunch itself as a probe. We find that, for much of the cavity that is devoid of plasma electrons, the transverse force is constant longitudinally to within ±3% (r.m.s.). Moreover, comparison of experimental data and simulations has resulted in mapping of the longitudinal electric field of the unloaded wake up to 83 GV m(-1) to a similar degree of accuracy. These results bode well for high-gradient, high-efficiency acceleration of electron bunches while preserving their emittance in such a cavity.
Collapse
Affiliation(s)
- C E Clayton
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA
| | - E Adli
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.,Department of Physics, University of Oslo, Oslo 0316, Norway
| | - J Allen
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - W An
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA.,Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA
| | - C I Clarke
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - S Corde
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.,LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Université Paris-Saclay, Palaiseau 91762, France
| | - J Frederico
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - S Gessner
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - S Z Green
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - M J Hogan
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - C Joshi
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA
| | - M Litos
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - W Lu
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - K A Marsh
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA
| | - W B Mori
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA.,Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA
| | - N Vafaei-Najafabadi
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA
| | - X Xu
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA.,Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA
| | - V Yakimenko
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| |
Collapse
|
20
|
Xu XL, Pai CH, Zhang CJ, Li F, Wan Y, Wu YP, Hua JF, Lu W, An W, Yu P, Joshi C, Mori WB. Nanoscale Electron Bunching in Laser-Triggered Ionization Injection in Plasma Accelerators. Phys Rev Lett 2016; 117:034801. [PMID: 27472116 DOI: 10.1103/physrevlett.117.034801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Indexed: 06/06/2023]
Abstract
Ionization injection is attractive as a controllable injection scheme for generating high quality electron beams using plasma-based wakefield acceleration. Because of the phase-dependent tunneling ionization rate and the trapping dynamics within a nonlinear wake, the discrete injection of electrons within the wake is nonlinearly mapped to a discrete final phase space structure of the beam at the location where the electrons are trapped. This phenomenon is theoretically analyzed and examined by three-dimensional particle-in-cell simulations which show that three-dimensional effects limit the wave number of the modulation to between >2k_{0} and about 5k_{0}, where k_{0} is the wave number of the injection laser. Such a nanoscale bunched beam can be diagnosed by and used to generate coherent transition radiation and may find use in generating high-power ultraviolet radiation upon passage through a resonant undulator.
Collapse
Affiliation(s)
- X L Xu
- University of California, Los Angeles, California 90095, USA
| | - C-H Pai
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - C J Zhang
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - F Li
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - Y Wan
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - Y P Wu
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - J F Hua
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - W Lu
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
- IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240, China
| | - W An
- University of California, Los Angeles, California 90095, USA
| | - P Yu
- University of California, Los Angeles, California 90095, USA
| | - C Joshi
- University of California, Los Angeles, California 90095, USA
| | - W B Mori
- University of California, Los Angeles, California 90095, USA
| |
Collapse
|
21
|
Zawistoski M, Sui J, Ordonez C, Mai V, Liu E, Li T, Kwok I, Kolodziej A, Kanawade A, Fitzpatrick R, Deshpande A, Dasgupta A, Cole B, Chin J, Bresilla C, Bailey V, An W, Krouse M. 32 Properties of a novel F508del-CFTR corrector FDL169. J Cyst Fibros 2016. [DOI: 10.1016/s1569-1993(16)30272-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
22
|
Xu XL, Hua JF, Wu YP, Zhang CJ, Li F, Wan Y, Pai CH, Lu W, An W, Yu P, Hogan MJ, Joshi C, Mori WB. Physics of Phase Space Matching for Staging Plasma and Traditional Accelerator Components Using Longitudinally Tailored Plasma Profiles. Phys Rev Lett 2016; 116:124801. [PMID: 27058082 DOI: 10.1103/physrevlett.116.124801] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Indexed: 06/05/2023]
Abstract
Phase space matching between two plasma-based accelerator (PBA) stages and between a PBA and a traditional accelerator component is a critical issue for emittance preservation. The drastic differences of the transverse focusing strengths as the beam propagates between stages and components may lead to a catastrophic emittance growth even when there is a small energy spread. We propose using the linear focusing forces from nonlinear wakes in longitudinally tailored plasma density profiles to control phase space matching between sections with negligible emittance growth. Several profiles are considered and theoretical analysis and particle-in-cell simulations show how these structures may work in four different scenarios. Good agreement between theory and simulation is obtained, and it is found that the adiabatic approximation misses important physics even for long profiles.
Collapse
Affiliation(s)
- X L Xu
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
- University of California, Los Angeles, California 90095, USA
| | - J F Hua
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - Y P Wu
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - C J Zhang
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - F Li
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - Y Wan
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - C-H Pai
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - W Lu
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
- IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240, China
| | - W An
- University of California, Los Angeles, California 90095, USA
| | - P Yu
- University of California, Los Angeles, California 90095, USA
| | - M J Hogan
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - C Joshi
- University of California, Los Angeles, California 90095, USA
| | - W B Mori
- University of California, Los Angeles, California 90095, USA
| |
Collapse
|
23
|
Corde S, Adli E, Allen JM, An W, Clarke CI, Clayton CE, Delahaye JP, Frederico J, Gessner S, Green SZ, Hogan MJ, Joshi C, Lipkowitz N, Litos M, Lu W, Marsh KA, Mori WB, Schmeltz M, Vafaei-Najafabadi N, Walz D, Yakimenko V, Yocky G. Multi-gigaelectronvolt acceleration of positrons in a self-loaded plasma wakefield. Nature 2015; 524:442-5. [PMID: 26310764 DOI: 10.1038/nature14890] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Accepted: 06/30/2015] [Indexed: 11/09/2022]
Abstract
Electrical breakdown sets a limit on the kinetic energy that particles in a conventional radio-frequency accelerator can reach. New accelerator concepts must be developed to achieve higher energies and to make future particle colliders more compact and affordable. The plasma wakefield accelerator (PWFA) embodies one such concept, in which the electric field of a plasma wake excited by a bunch of charged particles (such as electrons) is used to accelerate a trailing bunch of particles. To apply plasma acceleration to electron-positron colliders, it is imperative that both the electrons and their antimatter counterpart, the positrons, are efficiently accelerated at high fields using plasmas. Although substantial progress has recently been reported on high-field, high-efficiency acceleration of electrons in a PWFA powered by an electron bunch, such an electron-driven wake is unsuitable for the acceleration and focusing of a positron bunch. Here we demonstrate a new regime of PWFAs where particles in the front of a single positron bunch transfer their energy to a substantial number of those in the rear of the same bunch by exciting a wakefield in the plasma. In the process, the accelerating field is altered--'self-loaded'--so that about a billion positrons gain five gigaelectronvolts of energy with a narrow energy spread over a distance of just 1.3 metres. They extract about 30 per cent of the wake's energy and form a spectrally distinct bunch with a root-mean-square energy spread as low as 1.8 per cent. This ability to transfer energy efficiently from the front to the rear within a single positron bunch makes the PWFA scheme very attractive as an energy booster to an electron-positron collider.
Collapse
Affiliation(s)
- S Corde
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.,LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Université Paris-Saclay, 91762 Palaiseau, France
| | - E Adli
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.,Department of Physics, University of Oslo, 0316 Oslo, Norway
| | - J M Allen
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - W An
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA.,Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA
| | - C I Clarke
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - C E Clayton
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA
| | - J P Delahaye
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - J Frederico
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - S Gessner
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - S Z Green
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - M J Hogan
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - C Joshi
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA
| | - N Lipkowitz
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - M Litos
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - W Lu
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - K A Marsh
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA
| | - W B Mori
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA.,Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA
| | - M Schmeltz
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - N Vafaei-Najafabadi
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA
| | - D Walz
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - V Yakimenko
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - G Yocky
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| |
Collapse
|
24
|
An W, Rainbow M, Cheung R. Impacts of surface inclination on the vertical loading rates and landing pattern in novice barefoot runners. Physiotherapy 2015. [DOI: 10.1016/j.physio.2015.03.198] [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: 11/16/2022]
|
25
|
Chong J, An W, Hung L, Cheung R. Cyclists with patellofemoral pain do not demonstrate altered hip and knee kinematics. Physiotherapy 2015. [DOI: 10.1016/j.physio.2015.03.415] [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: 11/28/2022]
|
26
|
Wong V, An W, Cheung R. Lower limb reaction force asymmetry in rowers with and without history of back injury. Physiotherapy 2015. [DOI: 10.1016/j.physio.2015.03.416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
27
|
Cai C, Au IPH, An W, Cheung RTH. Facilitatory and inhibitory effects of Kinesio tape: Fact or fad? J Sci Med Sport 2015; 19:109-12. [PMID: 25687484 DOI: 10.1016/j.jsams.2015.01.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [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: 11/27/2014] [Revised: 01/15/2015] [Accepted: 01/28/2015] [Indexed: 10/24/2022]
Abstract
OBJECTIVES Kinesio tape (KT) is a commonly used intervention in sports. It claims to be able to alter the muscle activity, in terms of both facilitation and inhibition, by certain application methods. This study compared the neuromuscular activity of the wrist extensor muscles and maximal grip strength with facilitatory, inhibitory KT, and tapeless condition in healthy adults who were ignorant about KT. Potential placebo effects were eliminated by deception. DESIGN Randomized deceptive trial. METHODS 33 participants performed maximal grip assessment in a randomly assigned order of three taping conditions: true facilitatory KT, inhibitory KT, and no tape. The participants were blindfolded during the evaluation. Under the pretense of applying a series of adhesive muscle sensors, KT was applied to their wrist extensor muscles of the dominant forearm in the first two conditions. Within-subject comparisons of normalized root mean square of the wrist extensors electromyographic activity and maximal grip strength were conducted across three taping conditions. RESULTS 31 out of 33 enlisted participants were confirmed to be ignorant about KT. No significant differences were found in the maximum grip strength (p=0.394), electromyographic activity (p=0.276), and self-perceived performance (p=0.825) between facilitatory KT, inhibitory KT, and tapeless conditions. CONCLUSIONS Neither facilitatory nor inhibitory effects were observed between different application techniques of KT in healthy participants. Clinically, alternative method should be used for muscle activity modulation.
Collapse
Affiliation(s)
- C Cai
- Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong
| | - I P H Au
- Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong
| | - W An
- Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong
| | - R T H Cheung
- Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong.
| |
Collapse
|
28
|
Litos M, Adli E, An W, Clarke CI, Clayton CE, Corde S, Delahaye JP, England RJ, Fisher AS, Frederico J, Gessner S, Green SZ, Hogan MJ, Joshi C, Lu W, Marsh KA, Mori WB, Muggli P, Vafaei-Najafabadi N, Walz D, White G, Wu Z, Yakimenko V, Yocky G. High-efficiency acceleration of an electron beam in a plasma wakefield accelerator. Nature 2014; 515:92-5. [DOI: 10.1038/nature13882] [Citation(s) in RCA: 346] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Accepted: 09/01/2014] [Indexed: 11/09/2022]
|
29
|
Xu XL, Hua JF, Li F, Zhang CJ, Yan LX, Du YC, Huang WH, Chen HB, Tang CX, Lu W, Yu P, An W, Joshi C, Mori WB. Phase-space dynamics of ionization injection in plasma-based accelerators. Phys Rev Lett 2014; 112:035003. [PMID: 24484147 DOI: 10.1103/physrevlett.112.035003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Indexed: 06/03/2023]
Abstract
The evolution of beam phase space in ionization injection into plasma wakefields is studied using theory and particle-in-cell simulations. The injection process involves both longitudinal and transverse phase mixing, leading initially to a rapid emittance growth followed by oscillation, decay, and a slow growth to saturation. An analytic theory for this evolution is presented and verified through particle-in-cell simulations. This theory includes the effects of injection distance (time), acceleration distance, wakefield structure, and nonlinear space charge forces, and it also shows how ultralow emittance beams can be produced using ionization injection methods.
Collapse
Affiliation(s)
- X L Xu
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - J F Hua
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - F Li
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - C J Zhang
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - L X Yan
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - Y C Du
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - W H Huang
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - H B Chen
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - C X Tang
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - W Lu
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China and University of California Los Angeles, Los Angeles, California 90095, USA
| | - P Yu
- University of California Los Angeles, Los Angeles, California 90095, USA
| | - W An
- University of California Los Angeles, Los Angeles, California 90095, USA
| | - C Joshi
- University of California Los Angeles, Los Angeles, California 90095, USA
| | - W B Mori
- University of California Los Angeles, Los Angeles, California 90095, USA
| |
Collapse
|
30
|
Vafaei-Najafabadi N, Marsh KA, Clayton CE, An W, Mori WB, Joshi C, Lu W, Adli E, Corde S, Litos M, Li S, Gessner S, Frederico J, Fisher AS, Wu Z, Walz D, England RJ, Delahaye JP, Clarke CI, Hogan MJ, Muggli P. Beam loading by distributed injection of electrons in a plasma wakefield accelerator. Phys Rev Lett 2014; 112:025001. [PMID: 24484020 DOI: 10.1103/physrevlett.112.025001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Indexed: 06/03/2023]
Abstract
We show through experiments and supporting simulations that propagation of a highly relativistic and dense electron bunch through a plasma can lead to distributed injection of electrons, which depletes the accelerating field, i.e., beam loads the wake. The source of the injected electrons is ionization of the second electron of rubidium (Rb II) within the wake. This injection of excess charge is large enough to severely beam load the wake, and thereby reduce the transformer ratio T. The reduction of the average T with increasing beam loading is quantified for the first time by measuring the ratio of peak energy gain and loss of electrons while changing the beam emittance. Simulations show that beam loading by Rb II electrons contributes to the reduction of the peak accelerating field from its weakly loaded value of 43 GV/m to a strongly loaded value of 26 GV/m.
Collapse
Affiliation(s)
- N Vafaei-Najafabadi
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA
| | - K A Marsh
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA
| | - C E Clayton
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA
| | - W An
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA
| | - W B Mori
- Department of Electrical Engineering, University of California Los Angeles, Los Angeles, California 90095, USA and Department of Physics and astronomy, University of California Los Angeles, Los Angeles, California 90095, USA
| | | | - W Lu
- Department of Physics and astronomy, University of California Los Angeles, Los Angeles, California 90095, USA and Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - E Adli
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA and Department of Physics, University of Oslo, 0316 Oslo, Norway
| | - S Corde
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - M Litos
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - S Li
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - S Gessner
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - J Frederico
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - A S Fisher
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Z Wu
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - D Walz
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - R J England
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - J P Delahaye
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - C I Clarke
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - M J Hogan
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - P Muggli
- Max Planck Institute for Physics, 80805 Munich, Germany
| |
Collapse
|
31
|
Kim JM, Heo K, Choi J, Kim K, An W. The histone variant MacroH2A regulates Ca(2+) influx through TRPC3 and TRPC6 channels. Oncogenesis 2013; 2:e77. [PMID: 24165580 PMCID: PMC3816217 DOI: 10.1038/oncsis.2013.40] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 09/05/2013] [Accepted: 09/11/2013] [Indexed: 12/11/2022] Open
Abstract
The histone variant macroH2A replaces canonical H2A in the designated region of chromatin where its incorporation has the potential to establish a functionally distinct chromatin domain. The transient receptor potential canonical (TRPC) channels are a family of Ca2+-permeable cationic channels controlling changes in the cytosolic Ca2+ concentration. The proper regulation of Trpc gene expression requires chromatin remodeling, but little is known about the nature of these regulatory processes. Here, we show that macroH2A1 represses two Trpc family genes, Trpc3 and Trpc6, and attenuates Ca2+-dependent proliferative responses in bladder cancer cells. MacroH2A1 recruits histone deacetylase 1 (HDAC1) and HDAC2 to facilitate its persistent action, resulting in a compromise of histone acetylation across the Trpc3 and Trpc6 loci. Further, macroH2A1 depletion augments histone acetylation and Ca2+ influx, leading to increased cell growth and invasion. Our data provide new insights into TRPC3/TRPC6-mediated Ca2+ signaling and indicate a central role for macroH2A1 in regulating transcriptional competence of Trpc3 and Trpc6 genes.
Collapse
Affiliation(s)
- J-M Kim
- Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, USA
| | | | | | | | | |
Collapse
|
32
|
Knyazev BA, An W, Bluhm H. Stark spectroscopy of a probe lithium beam excited with two dye lasers as a technique to study a high-power ion-beam diode. Rev Sci Instrum 2012; 83:033101. [PMID: 22462900 DOI: 10.1063/1.3690384] [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] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A non-disturbing measurement of electric field distributions is a subject of special interest in plasma physics and high-voltage devices. In this paper we describe a diagnostic technique for remote sensing of electric fields via injection of a probe beam of lithium atoms and cascade excitation of resonance fluorescence with two broadband dye lasers. The fluorescence spectrum was recorded using a monochromator equipped with an optical multi-channel analyser. The magnitude of the local electric field was retrieved from the Stark-shifted components of the 3d-2p lithium spectral line. The technique was applied to measurements of the electric field in the applied-B-field high-voltage diode of the 1 TW KALIF ion-beam accelerator.
Collapse
Affiliation(s)
- B A Knyazev
- Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk, Russia.
| | | | | |
Collapse
|
33
|
Abstract
The in situ growth stress and postgrowth stress relaxation during the L1(0) chemical ordering of Fe0.54Pt0.46 thin films have been characterized. The compressive stress is reduced with an increase in order parameter. The postgrowth stress relaxation rate increased with the order parameter and is rationalized in terms of an increase in the interfacial energy contribution at the grain boundaries because of chemical order. Density functional theory calculations were performed to quantify possible diffusion pathways and binding energies for Fe and Pt that may mitigate surface migration.
Collapse
Affiliation(s)
- B Fu
- Department of Metallurgical and Materials Engineering, The University of Alabama, Tuscaloosa, Alabama 35487-0202, USA
| | | | | | | |
Collapse
|
34
|
|
35
|
Gao JM, Hu JY, Wan Y, An W, An L, Zheng ZG. Butyltin compounds distribution in the coastal waters of Bohai Bay, People's Republic of China. Bull Environ Contam Toxicol 2004; 72:945-953. [PMID: 15266690 DOI: 10.1007/s00128-004-0335-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Affiliation(s)
- J M Gao
- Department of Urban and Environmental Science, College of Environmental Science, Peking University, Beijing, 100871, People's Republic of China
| | | | | | | | | | | |
Collapse
|
36
|
An W, Du HJ, Chen L. [Increased cellular proliferation in BEL-7402 hepatoma cells transfected by human hepatic stimulator substance gene]. Sheng Li Xue Bao 2001; 53:473-7. [PMID: 11930229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
A hepatotropic factor originally identified in weanling or regenerating rat livers, known as hepatic stimulator substance (HSS), is characterized by promoting markedly liver regeneration after partial hepatectomy. Although HSS gene and the gene product have been described recently, the cellular mechanism of HSS and its genetic function remain obscure. In our previous studies, human HSS (hHSS) was demonstrated to promote the growth of hepatoma cells and phosphorylate the mitogen-activated protein kinase (MAPK). In this study, we reported the growth features of human hepatoma cells response to hHSS gene transfection. The hHSS eukaryotic vector was transfected to BEL-7402 hepatoma cells and the expression of hHSS was analyzed with Northern and Southern blot. The results showed that the HSS recombinant construct was functionally expressed in the target cells as analyzed with Northern blot and reverse transcriptase polymerase chain reaction (RT-PCR). The growth potential of HSS transfected hepatoma cells was markedly enhanced as compared with the non transfected cells. The S-phase of the hHSS-transfected cells increased by 61.5% than that of the non-transfected cells as shown by flow cytometry. Moreover, MAPK phosphorylation, one of the most important mitogenic indexes of growth signal cascade, was profoundly activated at sites of Thr202/Tyr204 due to HSS gene transfer. Based on these results, it is concluded that the introduction of HSS gene into hepatoma cells might be able to stimulate directly the cellular growth in vitro, allowing a possibility of reevaluation of HSS mechanism in intact cells.
Collapse
Affiliation(s)
- W An
- Department of Cell Biology, Capital University of Medical Sciences, Beijing 100054, China.
| | | | | |
Collapse
|
37
|
Abstract
Retroviral genetic rearrangements can result from reverse transcriptase template switching. Most published data suggest that errors such as base misincorporation occur at similar frequencies for HIV-1 and for simple retroviruses such as spleen necrosis virus (SNV) and murine leukemia virus (MuLV). However, previous reports have suggested that template switch-mediated recombination is much more frequent for HIV-1 than for simple retroviruses. In this report, direct repeat deletion vectors similar to those previously used for measuring template switching events for SNV and MuLV were developed for HIV-1. Forward mutation rates and the frequency of template switching during a single cycle of HIV-1 replication were determined. The frequency of HIV-1-mediated repeat deletion was measured for three separate internal repeats in lacZ and was compared to rates observed with identical repeats for MuLV. The results indicated that the error rate and the frequency of repeat deletion of HIV-1 were similar to those of MuLV.
Collapse
Affiliation(s)
- W An
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109-0620, USA
| | | |
Collapse
|
38
|
Lu SC, Alvarez L, Huang ZZ, Chen L, An W, Corrales FJ, Avila MA, Kanel G, Mato JM. Methionine adenosyltransferase 1A knockout mice are predisposed to liver injury and exhibit increased expression of genes involved in proliferation. Proc Natl Acad Sci U S A 2001; 98:5560-5. [PMID: 11320206 PMCID: PMC33252 DOI: 10.1073/pnas.091016398] [Citation(s) in RCA: 329] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Liver-specific and nonliver-specific methionine adenosyltransferases (MATs) are products of two genes, MAT1A and MAT2A, respectively, that catalyze the formation of S-adenosylmethionine (AdoMet), the principal biological methyl donor. Mature liver expresses MAT1A, whereas MAT2A is expressed in extrahepatic tissues and is induced during liver growth and dedifferentiation. To examine the influence of MAT1A on hepatic growth, we studied the effects of a targeted disruption of the murine MAT1A gene. MAT1A mRNA and protein levels were absent in homozygous knockout mice. At 3 months, plasma methionine level increased 776% in knockouts. Hepatic AdoMet and glutathione levels were reduced by 74 and 40%, respectively, whereas S-adenosylhomocysteine, methylthioadenosine, and global DNA methylation were unchanged. The body weight of 3-month-old knockout mice was unchanged from wild-type littermates, but the liver weight was increased 40%. The Affymetrix genechip system and Northern and Western blot analyses were used to analyze differential expression of genes. The expression of many acute phase-response and inflammatory markers, including orosomucoid, amyloid, metallothionein, Fas antigen, and growth-related genes, including early growth response 1 and proliferating cell nuclear antigen, is increased in the knockout animal. At 3 months, knockout mice are more susceptible to choline-deficient diet-induced fatty liver. At 8 months, knockout mice developed spontaneous macrovesicular steatosis and predominantly periportal mononuclear cell infiltration. Thus, absence of MAT1A resulted in a liver that is more susceptible to injury, expresses markers of an acute phase response, and displays increased proliferation.
Collapse
Affiliation(s)
- S C Lu
- Liver Disease Research Center, Research Center for Alcoholic Liver and Pancreatic Diseases, University of Southern California-University of California, Los Angeles, CA 90033, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Chen L, An W, Tan X, Gao D, Dai J. Phosphorylation of hepatic stimulator substance on mitogen-activated protein kinase in BEL-7402 hepatoma cells. Zhonghua Gan Zang Bing Za Zhi 2001; 9:22-4. [PMID: 11242129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
OBJECTIVE To obtain more insight into information of signal transduction of EGF-receptor-mediated pathway response to the stimulation of hepatic stimulator substance (HSS). METHODS HSS was extracted from weanling rat liver and partially purified. Bioactivity of HSS was confirmed with its ability to proliferate hepatoma cell in vitro. Meanwhile, a rat recombinant HSS vector was constructed and expressed in BL-21 E. Coli. Mitogen-activated protein kinase (MAPK) activation marked by phosphorylation at Thr202/Tyr204 was determined by Western blot. RESULTS The molecular weight of the biochemically purified HSS was found identically to that of the recombined HSS as expressed in the prokaryotic cells. After the treatment of HSS, cellular MAPK phosphorylation was initiated obviously at 15 min and maintained to 30 min. In comparison with EGF, MAPK phosphorylation as stimulated by HSS appeared less intensive and later time-kinetics as well. The HSS induction on cellular MAPK phosphorylation was gradually inhibited by PD98059, a specific inhibitor of MAPK kinase (MEK). A complete blockade was seen at 100 micromol/L of PD98059. CONCLUSIONS The involvement of HSS on MAPK activation implies that this liver-specific growth factor might take part in, either individually or as combined with other growth factors, the regulation of TPK signaling cascade during hepatocyte proliferation.
Collapse
Affiliation(s)
- L Chen
- Department of Cell Biology, Capital University of Medical Sciences, Beijing 100054, China
| | | | | | | | | |
Collapse
|
40
|
Zhang L, Li L, Ban L, An W, Liu S, Li X, Xue B, Xu Y. [Effect of sodium azide on mitochondrial membrane potential in SH-SY5Y human neuroblastoma cells]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 2000; 22:436-9. [PMID: 12903423] [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: 03/04/2023]
Abstract
OBJECTIVE To study the role of mitochondrial deficiency in the pathogenesis of neurodegenerative disease by investigating the energy metabolism in a sodium azide inhibited cytochrome-c oxidase SH-SY5Y Cell model. METHODS Human neuroblastoma SH-SY5Y Cells were exposed to sodium azide, then mitochondrial complex IV activity was assayed by microassay method; cell viability was measured by Thiazolyl blue(MTT) method; mitochondrial membrane potential (MMP) was detected by confocal microscopy and flow cytometry. RESULTS Cultured SH-SY5Y cells were exposed to 16-64 mmol/L sodium azide for 1 hour, the mitochondrial complex IV activity decreased dose-dependently. MTT absorbance decreased does- and time-dependently in cultured nerve cells treated by 16-128 mmol/L sodium azide for 1-8 hours. After the treatment of 16 mmol/L sodium azide for 1 hour, both the fluorescence intensity of MMP and normal cell events reduced. Decrease of MMP was significant especially in cell processes. CONCLUSION Sodium azide induced the impairment of mitochondrial energy synthesis in the cultured nerve cells which is an important cause in cell death.
Collapse
Affiliation(s)
- L Zhang
- Department of Pharmacology, Xuan-Wu Hospital, Capital University of Medical Sciences, Beijing Key Laboratory for Brain Aging, Beijing 100053, China.
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Kobayashi A, Higashide T, Hamasaki D, Kubota S, Sakuma H, An W, Fujimaki T, McLaren MJ, Weleber RG, Inana G. HRG4 (UNC119) mutation found in cone-rod dystrophy causes retinal degeneration in a transgenic model. Invest Ophthalmol Vis Sci 2000; 41:3268-77. [PMID: 11006213] [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: 02/17/2023] Open
Abstract
PURPOSE To investigate the function and pathogenicity of HRG4, a photoreceptor synaptic protein homologous to the Caenorhabditis elegans neuroprotein UNC119. METHODS HRG4 was screened for mutations in patients with various retinopathies, and a transgenic mouse model was constructed and analyzed based on a mutation found. RESULTS A heterozygous premature termination codon mutation was found in a 57-year-old woman with late-onset cone-rod dystrophy. In some transgenic mice carrying the identical mutation, age-dependent fundus lesions developed accompanied by electroretinographic changes consistent with defects in photoreceptor synaptic transmission (depressed b-wave, normal c-wave), and retinal degeneration occurred with marked synaptic and possible transsynaptic degeneration. CONCLUSIONS HRG4, the only synaptic protein known to be highly enriched in photoreceptor ribbon synapses, is now shown to be pathogenic when mutated.
Collapse
Affiliation(s)
- A Kobayashi
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, Florida, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Kundu TK, Palhan VB, Wang Z, An W, Cole PA, Roeder RG. Activator-dependent transcription from chromatin in vitro involving targeted histone acetylation by p300. Mol Cell 2000; 6:551-61. [PMID: 11030335 DOI: 10.1016/s1097-2765(00)00054-x] [Citation(s) in RCA: 183] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The transcriptional coactivator p300 shows physical and functional interactions with a diverse group of activators and contains an intrinsic acetyltransferase activity whose exact coactivator functions in the acetylation of nucleosomal histones versus other factors are poorly documented. Here, we show that p300 mediates acetyl-CoA-dependent transcription by GAL4-VP16 from a nucleosomal array template, that this involves p300 targeting by GAL4-VP16 and promoter-proximal histone acetylation prior to transcription, and that the affinities of different activators for p300 roughly correlate with corresponding levels of p300-dependent transcription. These results indicate that activators recruit p300 to nucleosomal templates by direct interactions and that bound p300 stimulates transcription, at least in part, by localized histone acetylation.
Collapse
Affiliation(s)
- T K Kundu
- Laboratory of Biochemistry and Molecular Biology, Rockefeller University, New York, New York 10021, USA
| | | | | | | | | | | |
Collapse
|
43
|
Dai J, An W, Gao DC, Chen L. [Influence of hepatic stimulator substance on p21(ras) expression in human hepatic carcinoma cells BEL-7402]. Sheng Li Xue Bao 2000; 52:225-9. [PMID: 11956569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
The hepatic stimulator substance (HSS) was partially purified from schedule-lighted weanling rat livers. The effects of HSS on p21(ras) expression of human hepatic carcinoma cell BEL-7402 were examined. The results showed: (1) HSS was capable of promoting the proliferation of the cells, and its molecular weight was 14 20 kD; (2) the p21(ras) expression was increased under HSS effect time-dependently, and the effect of HSS appeared synergistic with EGF; (3) the p21(ras) expression induced by HSS manifested a dose-dependent manner, and the saturation effect of HSS occurred at the concentration of 100 microgram/ml. Considering together with our previous report about HSS regulation on EGF receptor, these results strongly suggest that the proliferatory effect of HSS on hepatic carcinoma cells is presumedly related with EGF receptor-mediated signal transduction.
Collapse
Affiliation(s)
- J Dai
- Department of Cell Biology, Capital University of Medical Sciences, Beijing 100054, China
| | | | | | | |
Collapse
|
44
|
Zhou Y, Li Z, An W, Chiou G. [Effects of synthetic interleukin-1 blockers on uveitis in rats]. Zhonghua Yan Ke Za Zhi 2000; 36:62-4. [PMID: 11853587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To investigate the therapeutic action of synthetic interleukin-1 blockers on uveitis in rats. METHOD Experiments were performed on 18 Spraque-Dawley rats (36 eyes), and the retinal interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) were quantified by an enzyme-linked immunoabsorbent assay (ELISA) before and after the rats with uveitis treated by synthetic interleukin-1 blockers. RESULT The retinal IL-1 beta and TNF-alpha in rats with uveitis treated by synthetic IL-1 blockers (CK-138, 139) were significantly decreased than those treated by contrasting design. CONCLUSION Synthetic IL-1 blockers (CK-138, 139) are effective in treatment of IL-1 alpha induced uveitis in the rat.
Collapse
Affiliation(s)
- Y Zhou
- Department of Ophthalmology, Tong Ren Hospital, The Capital University of Medical Sciences, Beijing 100730, China
| | | | | | | |
Collapse
|
45
|
Abstract
The therapeutic effect of herpes simplex virus thymidine kinase/ganciclovir (HSV-tk/GCV) system on hepatocellular carcinoma was studied in this experiment. The tk-containing retroviral recombinants were used to infect hepatoma cells (BEL-7402) and the cells were treated with ganciclovir (0-1000 microg/ml). The results showed that HSV-tk gene could be efficiently transferred in vitro into hepatoma cells and stably expressed. The growth potential of the tk-containing cells was significantly inhibited by GCV (P<0.01) as compared to the non-tk-containing cells. The antitumor effect of HSV-tk/GCV system was also produced ex vivo in tk-containing tumor of nude mice as characterized by a marked decrease in tumor growth after GCV treatment contrary to a progressive enlargement of non-tk-containing tumors. Although the histological examination demonstrated that the efficiency of the gene transfer was less than 30%, the killing effect of HSV-tk/GCV system on hepatocellular carcinoma was still significantly generated. The proper mechanism of HSV-tk gene therapy on hepatic tumor referred as "bystander effect" in therapeutic approach has not been found in this study and required to be explored further.
Collapse
|
46
|
Abstract
Using nucleosomes reconstituted on a defined sequence of DNA, we have investigated the question as to whether the N-terminal tails of core histones play a role in determining the site of binding of a linker histone. Reconstitutes used histone cores of three types: intact, lacking the N-terminal H3 tails, or lacking all tails. In each case the same, single defined position for the histone core was observed, using high-resolution mapping. The affinity for binding of linker histone H1(o) was highest for the intact cores, lowest for the tailless cores. However, the location of the linker histone, as judged by micrococcal nuclease protection, was exactly the same in each case, an asymmetric site of about 17 bp to one side of the core particle DNA.
Collapse
Affiliation(s)
- W An
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis 97331-7305, USA
| | | | | | | |
Collapse
|
47
|
Zheng XC, An W, Bai JX, Mao SH, Wu YJ. [Expression of human superoxide dismutase gene in rat vascular smooth muscle cells and its anti-oxidative effect]. Sheng Li Xue Bao 1999; 51:199-205. [PMID: 11499016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
A retroviral vector containing human superoxide dismutase (SOD) cDNA was constructed and transfected into rat vascular smooth muscle cells (VSMCs). The expression of exogenous hSOD1 in the VSMCs was analyzed with Northern and Southern blot. The protection of the transfected and/or non-transfected VSMCs from free radical produced by the xanthine/xanthine oxidase (X/XO) system was investigated. The results showed that the construction strategy of the vector was correctly performed and the expression of hSOD1 in the transfected cells was highly detectable. The cell damage of X/XO could be alleviated with expression of hSOD1 in the transfected cells, as compared to control. In addition, proliferation of the transfected VSMCs resulted from oxidative stress was suppressed. It is suggested that the expression of gene-transferred hSOD1 is able to prevent the formation of atherosclerosis, partially due to its cell protection and inhibition of the proliferative embolization.
Collapse
Affiliation(s)
- X C Zheng
- Department of Pathophysiology, Beijing Medical University, Beijing 100083
| | | | | | | | | |
Collapse
|
48
|
Zhou Y, Li Z, An W, Qi Y, Zhang K, Lu W, Hu Y. Corneal topographic analysis after excimer photorefractive keratectomy. Chin Med J (Engl) 1999; 112:214-6. [PMID: 11593551] [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: 02/21/2023] Open
Abstract
OBJECTIVE To evaluate the corneal surface changes and visual quality after excimer photorefractive keratectomy (PRK) for myopia. METHODS Corneal topographic analysis was performed on 23 patients (38 eyes) with myopia after PRK at the 1-, 3-, 6- month postoperative follow-up visits. RESULTS The corneal sphericity was changed after excimer PRK. As time went on, the mean surface regularity index (SRI) and the surface asymmetry index (SAI) decreased gradually, and the corneal surface became more smooth; mean simulated keratoscope readings (SimK) showed a gradual restoration. At the 6-month postoperative examination, corneal topography showed four main patterns of ablation: round or oblong (50%), collar-button (23.68%), semicircular (18.42%) and central island (7.9%). Patterns of ablation were correlated with visual acuity. CONCLUSION The quantitative analysis of corneal topography is essential for evaluating corneal surface changes after PRK and helpful in the surgical design of PRK and in predicting the refractive outcome with greater precision.
Collapse
Affiliation(s)
- Y Zhou
- Department of Ophthalmology, Tong Ren Hospital, Beijing 100730, China
| | | | | | | | | | | | | |
Collapse
|
49
|
Abstract
The cytosolic liver-specific growth factor-hepatic stimulator substance (HSS) has been shown to be able to amplify the rat hepatocyte proliferation responded to EGF. In order to get more insight into the mechanism, the regulatory effect of HSS on EGF-receptor (EGF-R) and the receptor phosphorylation at molecular level was studied. HSS partially purified from weanling rat liver was given to cultured hepatocytes and its influence on EGF-R specific binding and internalization as well as mRNA expression were investigated. The results showed that preincubation of hepatocytes with HSS could lead to an increase in [125I]-EGF binding to its receptors and inhibit EGF-induced receptor down-regulation. Furthermore, the over-expression of EGF-R mRNA stimulated by HSS was seen during 2-12 h after the incubation. Additionally, it was demonstrated with human hepatoma SMMC-7721 cells in Western blot that the EGF-R expression and the receptor autophosphorylation were increased with dose/time-dependency after HSS treatment. These results strongly suggest that the mechanism of HSS action on hepatocyte growth might be related to its modulation on EGF-R and receptor-mediated signaling transduction.
Collapse
Affiliation(s)
- W An
- Department of Cell Biology, Capital University of Medical Sciences, Beijing, China.
| | | | | | | | | |
Collapse
|
50
|
Li J, Nishizawa K, An W, Hussey RE, Lialios FE, Salgia R, Sunder-Plassmann R, Reinherz EL. A cdc15-like adaptor protein (CD2BP1) interacts with the CD2 cytoplasmic domain and regulates CD2-triggered adhesion. EMBO J 1998; 17:7320-36. [PMID: 9857189 PMCID: PMC1171078 DOI: 10.1093/emboj/17.24.7320] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A human CD2 cytoplasmic tail-binding protein, termed CD2BP1, was identified by an interaction trap cloning method. Expression of CD2BP1 is restricted to hematopoietic tissue, being prominent in T and natural killer (NK) cells, with long (CD2BP1L) and short (CD2BP1S) variants arising by alternative RNA splicing. Both CD2BP1 molecules are homologous to Schizosaccharomyces pombe cdc15, and include a helical domain, variable length intervening PEST sequence and C-terminal SH3 domain. Although the CD2BP1 SH3 domain binds directly to the CD2 sequence, KGPPLPRPRV (amino acids 300-309), its association is augmented markedly by the CD2BP1 N-terminal segment. Upon ligand-induced clustering of surface CD2 molecules, CD2BP1 redistributes from a cytosolic to a surface membrane compartment, co-localizing with CD2. In turn, CD2-stimulated adhesion is downregulated by CD2BP1, apparently through coupling of the protein tyrosine phosphatase (PTP)-PEST to CD2. These findings offer the first molecular view into the control processes for T cell adhesion.
Collapse
Affiliation(s)
- J Li
- Laboratory of Immunobiology, Harvard Medical School, 44 Binney Street J318, Boston, MA 02115, USA
| | | | | | | | | | | | | | | |
Collapse
|