1
|
Cho M, Oh E, Ahn B, Yoon M. Response surface analyses of antihypertensive effects of angiotensin receptor blockers and amlodipine or hydrochlorothiazide combination therapy in patients with essential hypertension. Transl Clin Pharmacol 2023; 31:154-166. [PMID: 37810629 PMCID: PMC10551747 DOI: 10.12793/tcp.2023.31.e15] [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: 07/25/2023] [Revised: 09/08/2023] [Accepted: 09/15/2023] [Indexed: 10/10/2023] Open
Abstract
While previous studies have examined the dose-response characteristics of certain antihypertensive drugs alone or in combination, response surface analysis for combination therapies involving angiotensin receptor blockers (ARBs) and either amlodipine (AML) or hydrochlorothiazide (HCT) has not been explored, particularly in the context of low-dose combinations. The objectives of present study were to generate useful dose-response information for the combination of ARB/AML or ARB/HCT and to predict the blood pressure lowering effects of combination therapies compared to monotherapies. We reviewed the New Drug Application data of combination drugs of ARB/AML and ARB/HCT. Data on systolic blood pressure (SBP), from studies conducted using a factorial dose-response design over a period of 8-12 weeks, were used. The placebo-subtracted SBP change was used for analysis. Response surface analyses of the collected data were conducted using a polynomial regression model. For ARB/AML combination, the quadratic polynomial regression model containing two linear terms, two quadratic terms, and one interaction term was best fitted to the naïve pooled data. Meanwhile, for ARB/HCT combination, the best-fitted model was a quadratic model that included two linear terms and two quadratic terms. The 1/2-dose combination of these medications, compared to each monotherapy, resulted in predicted SBP reductions that were 8-30% greater. The ratio of the estimated antihypertensive effects of the combination to the expected additive effects of each component ranged from 82% to 100% of the expected effect. These results can provide a rationale for developing lower-dose combinations of ARB/AML or ARB/HCT and assist in designing clinical trials.
Collapse
|
2
|
Youk S, Le MT, Kang M, Ahn B, Choi M, Kim K, Kim TH, Kim JH, Ho CS, Park C. Development of a high-resolution typing method for SLA-3, swine MHC class I antigen 3. Anim Genet 2021; 53:166-170. [PMID: 34910829 DOI: 10.1111/age.13161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/24/2021] [Indexed: 10/19/2022]
Abstract
We developed a high-resolution and comprehensive typing method for swine leukocyte antigen 3 (SLA-3), an MHC class I gene, employing locus-specific genomic PCR followed by subsequent direct sequencing. A total of 292 individuals from nine pure, one cross-breed and six cell lines were successfully typed. A total of 21 SLA-3 alleles were identified, of which four were found to be novel alleles. However, the allelic diversity of SLA-3 was lower than that of previously reported class I genes, SLA-1 and -2. More SLA-3 alleles were observed in the Landrace and Yorkshire breeds than the other breeds. SLA-3*04:01 was identified in seven out of nine breeds and was the most widely distributed allele across all breeds. Therefore, the typing method reported in this study completes our efforts to develop high-resolution typing methods for major SLA molecules, facilitating the combined analysis of major SLA genes from field samples, which is important to understand the relationship between the adaptive immune responses against pathogens and the immunogenetic makeup of an individual.
Collapse
Affiliation(s)
- S Youk
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, Gwangjin-gu, Seoul, 05029, Korea
| | - M T Le
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, Gwangjin-gu, Seoul, 05029, Korea
| | - M Kang
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, Gwangjin-gu, Seoul, 05029, Korea
| | - B Ahn
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, Gwangjin-gu, Seoul, 05029, Korea
| | - M Choi
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, Gwangjin-gu, Seoul, 05029, Korea
| | - K Kim
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, Gwangjin-gu, Seoul, 05029, Korea.,Livestock Support Department, National Agricultural Cooperative Federation Agribusiness Group, Seoul, 04516, Korea
| | - T H Kim
- Animal Genomics and Bioinformatics Division, National Institute of Animal Science, RDA, Wanju, 55365, Korea
| | - J H Kim
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, Gwangjin-gu, Seoul, 05029, Korea
| | - C S Ho
- Gift of Hope Organ and Tissue Donor Network, 425 Spring Lake Drive, Itasca, IL, 60143, USA
| | - C Park
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, Gwangjin-gu, Seoul, 05029, Korea
| |
Collapse
|
3
|
Muller Moran H, Maurice-Ventouris M, Alharbi M, Ahn B, Harley J, Lachapelle K. PAN-CANADIAN INITIATIVE ON FUNDAMENTAL COMPETENCIES FOR TRANSCATHETER CARDIAC SURGERY: A MODIFIED DELPHI CONSENSUS STUDY. Can J Cardiol 2021. [DOI: 10.1016/j.cjca.2021.07.187] [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] Open
|
4
|
Ahn B, Yoon S, Lee G, Kim H, Jang S, Hwang H. MA14.05 Clinicopathologic and Genomic Significances of the Amount of High-Grade Histologic Components in Lung Adenocarcinoma. J Thorac Oncol 2021. [DOI: 10.1016/j.jtho.2021.08.185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
5
|
Lee J, Ahn B, Kim M, Pyo K, Lee C, Lim S, Hong M, Kim H, Cho B. P59.01 Clinical Characteristics of Patients With MET Amplification-Positive NSCLC After EGFR-TKI Therapy. J Thorac Oncol 2021. [DOI: 10.1016/j.jtho.2021.08.590] [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]
|
6
|
Ahn B, Kim J, Lim S, Lim S, Kim H, Hong M, Cho B. FP14.14 Post Hoc Analyses from an Open Label, Multi-Centre, ASTRIS Trial of Efficacy of Osimertinib for CNS Metastases with T790M-Positive Advanced NSCLC. J Thorac Oncol 2021. [DOI: 10.1016/j.jtho.2021.01.157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
7
|
Hong M, Ahn B, Kim H, Lim S, Lee S, Park S, Lee C, Lee J, Kim D, Lee S, Yoon H, Lee C, Cho J, Shim H, Kim T, Cho B. FP03.02 Interim Analysis of Neoadjuvant Chemoradiotherapy and Durvalumab for Potentially Resectable Stage III Non-Small Cell Lung Cancer (NSCLC). J Thorac Oncol 2021. [DOI: 10.1016/j.jtho.2021.01.084] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
8
|
Lim S, Yang S, Lim S, Heo S, Daniel S, Markovets A, Rafati M, Park C, Yun J, Pyo K, Yun M, Ahn B, Hong M, Kim H, Cho B. P76.18 Tissue- and Plasma-Based Landscape of Resistance to Osimertinib. J Thorac Oncol 2021. [DOI: 10.1016/j.jtho.2021.01.1075] [Citation(s) in RCA: 1] [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: 11/25/2022]
|
9
|
Ahn B, Lee S, Olsen S, Mehta D, Lim S, Hong M, Kim H, Cho B. P89.08 Real-World Impact of Plasma Cell-Free DNA Next-Generation Sequencing to Detect Actionable Genomic Alterations in Advanced NSCLC. J Thorac Oncol 2021. [DOI: 10.1016/j.jtho.2021.01.1273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
10
|
Ahn B. 4.11-P12“In the beginning, there is…”: The role of lived-experience in identity-work among second generation of 'ex-Yugoslavian migrants in Austria. Eur J Public Health 2018. [DOI: 10.1093/eurpub/cky048.177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- B Ahn
- University of Vienna, Austria
| |
Collapse
|
11
|
Lee J, Lee J, Chae B, Ahn B, Ok J. Fully dedifferentiated chondrocyte expanded in specific mesenchymal stem cell growth medium with FGF2 obtains mesenchymal stem cell phenotype in vitro but retains chondrocyte phenotype in vivo. Cytotherapy 2017. [DOI: 10.1016/j.jcyt.2017.02.260] [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: 10/19/2022]
|
12
|
Cho H, Hong C, Doh I, Ahn B. SU-F-I-22: Development and Implementation of Task-Specific Modular Phantom for MRI Quality Evaluation. Med Phys 2016. [DOI: 10.1118/1.4955850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
13
|
Förg B, Schötz J, Süßmann F, Förster M, Krüger M, Ahn B, Okell WA, Wintersperger K, Zherebtsov S, Guggenmos A, Pervak V, Kessel A, Trushin SA, Azzeer AM, Stockman MI, Kim D, Krausz F, Hommelhoff P, Kling MF. Attosecond nanoscale near-field sampling. Nat Commun 2016; 7:11717. [PMID: 27241851 PMCID: PMC4895016 DOI: 10.1038/ncomms11717] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [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: 02/25/2016] [Accepted: 04/24/2016] [Indexed: 12/04/2022] Open
Abstract
The promise of ultrafast light-field-driven electronic nanocircuits has stimulated the development of the new research field of attosecond nanophysics. An essential prerequisite for advancing this new area is the ability to characterize optical near fields from light interaction with nanostructures, with sub-cycle resolution. Here we experimentally demonstrate attosecond near-field retrieval for a tapered gold nanowire. By comparison of the results to those obtained from noble gas experiments and trajectory simulations, the spectral response of the nanotaper near field arising from laser excitation can be extracted. Photoemission from nanometre-scale structures offer a route toward ultrafast light-field-driven electronic nanocircuits. Here, the authors use attosecond streaking spectroscopy for nanoscale characterization of near-fields in the vicinity of tapered gold nanowires.
Collapse
Affiliation(s)
- B Förg
- Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany.,Department of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, D-85748 Garching, Germany
| | - J Schötz
- Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany.,Department of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, D-85748 Garching, Germany
| | - F Süßmann
- Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany.,Department of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, D-85748 Garching, Germany
| | - M Förster
- Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany.,Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstraße 1, D-91058 Erlangen, Germany
| | - M Krüger
- Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany.,Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstraße 1, D-91058 Erlangen, Germany
| | - B Ahn
- Department of Physics, CASTECH, POSTECH, Pohang, Kyungbuk 790-784, Republic of Korea.,Max Planck Center for Attosecond Science, Pohang, Kyungbuk 790-784, Republic of Korea
| | - W A Okell
- Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany
| | - K Wintersperger
- Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany
| | - S Zherebtsov
- Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany.,Department of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, D-85748 Garching, Germany
| | - A Guggenmos
- Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany.,Department of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, D-85748 Garching, Germany
| | - V Pervak
- Department of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, D-85748 Garching, Germany
| | - A Kessel
- Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany
| | - S A Trushin
- Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany
| | - A M Azzeer
- Attosecond Science Laboratory, King-Saud University, Riyadh 11451, Saudi Arabia
| | - M I Stockman
- Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany.,Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303, USA
| | - D Kim
- Department of Physics, CASTECH, POSTECH, Pohang, Kyungbuk 790-784, Republic of Korea.,Max Planck Center for Attosecond Science, Pohang, Kyungbuk 790-784, Republic of Korea
| | - F Krausz
- Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany.,Department of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, D-85748 Garching, Germany
| | - P Hommelhoff
- Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany.,Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstraße 1, D-91058 Erlangen, Germany
| | - M F Kling
- Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, D-85748 Garching, Germany.,Department of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, D-85748 Garching, Germany
| |
Collapse
|
14
|
Ahn B, Schötz J, Okell WA, Süßmann F, Förg B, Kim SC, Kling MF, Kim D. Optimization of a nanotip on a surface for the ultrafast probing of propagating surface plasmons. Opt Express 2016; 24:92-101. [PMID: 26832240 DOI: 10.1364/oe.24.000092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We theoretically analyze a method for characterizing propagating surface plasmon polaritons (SPPs) on a thin gold film. The SPPs are excited by few-cycle near-infrared pulses using Kretschmann coupling, and a nanotip is used as a local field sensor. This geometry removes the influence of the incident excitation laser from the near fields, and enhances the plasmon electric field strength. Using finite-difference-time-domain studies we show that the geometry can be used to measure SPP waveforms as a function of propagation distance. The effects of the nanotip shape and material on the field enhancement and plasmonic response are discussed.
Collapse
|
15
|
Süßmann F, Seiffert L, Zherebtsov S, Mondes V, Stierle J, Arbeiter M, Plenge J, Rupp P, Peltz C, Kessel A, Trushin SA, Ahn B, Kim D, Graf C, Rühl E, Kling MF, Fennel T. Field propagation-induced directionality of carrier-envelope phase-controlled photoemission from nanospheres. Nat Commun 2015; 6:7944. [PMID: 26264422 PMCID: PMC4557130 DOI: 10.1038/ncomms8944] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [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: 02/28/2015] [Accepted: 06/27/2015] [Indexed: 12/12/2022] Open
Abstract
Near-fields of non-resonantly laser-excited nanostructures enable strong localization of ultrashort light fields and have opened novel routes to fundamentally modify and control electronic strong-field processes. Harnessing spatiotemporally tunable near-fields for the steering of sub-cycle electron dynamics may enable ultrafast optoelectronic devices and unprecedented control in the generation of attosecond electron and photon pulses. Here we utilize unsupported sub-wavelength dielectric nanospheres to generate near-fields with adjustable structure and study the resulting strong-field dynamics via photoelectron imaging. We demonstrate field propagation-induced tunability of the emission direction of fast recollision electrons up to a regime, where nonlinear charge interaction effects become dominant in the acceleration process. Our analysis supports that the timing of the recollision process remains controllable with attosecond resolution by the carrier-envelope phase, indicating the possibility to expand near-field-mediated control far into the realm of high-field phenomena. The localized enhancement of laser light in optical near-fields of nanostructures enables the steering of ultrafast electronic motion. Here, the authors employ field propagation in nanospheres to obtain directional tunability and attosecond control of near-field-induced strong-field photoemission.
Collapse
Affiliation(s)
- F Süßmann
- Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany.,Physics Department, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany
| | - L Seiffert
- Institut für Physik, Universität Rostock, D-18051 Rostock, Germany
| | - S Zherebtsov
- Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany.,Physics Department, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany
| | - V Mondes
- Physical Chemistry, Freie Universität Berlin, Takustr. 3, D-14195 Berlin, Germany
| | - J Stierle
- Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany
| | - M Arbeiter
- Institut für Physik, Universität Rostock, D-18051 Rostock, Germany
| | - J Plenge
- Physical Chemistry, Freie Universität Berlin, Takustr. 3, D-14195 Berlin, Germany
| | - P Rupp
- Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany.,Physics Department, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany
| | - C Peltz
- Institut für Physik, Universität Rostock, D-18051 Rostock, Germany
| | - A Kessel
- Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany
| | - S A Trushin
- Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany
| | - B Ahn
- Department of Physics, Center for Attosecond Science and Technology, Pohang University of Science and Technology, Pohang 790-784, South Korea.,Max Planck Center for Attosecond Science, Max Planck POSTECH/KOREA Res. Init., Pohang 790-784, South Korea
| | - D Kim
- Department of Physics, Center for Attosecond Science and Technology, Pohang University of Science and Technology, Pohang 790-784, South Korea.,Max Planck Center for Attosecond Science, Max Planck POSTECH/KOREA Res. Init., Pohang 790-784, South Korea
| | - C Graf
- Physical Chemistry, Freie Universität Berlin, Takustr. 3, D-14195 Berlin, Germany
| | - E Rühl
- Physical Chemistry, Freie Universität Berlin, Takustr. 3, D-14195 Berlin, Germany
| | - M F Kling
- Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany.,Physics Department, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany.,Department of Physics, Center for Attosecond Science and Technology, Pohang University of Science and Technology, Pohang 790-784, South Korea.,J.R. Macdonald Laboratory, Physics Department, Kansas-State University, Manhattan, Kansas, USA
| | - T Fennel
- Institut für Physik, Universität Rostock, D-18051 Rostock, Germany
| |
Collapse
|
16
|
Li H, Mignolet B, Wachter G, Skruszewicz S, Zherebtsov S, Süssmann F, Kessel A, Trushin SA, Kling NG, Kübel M, Ahn B, Kim D, Ben-Itzhak I, Cocke CL, Fennel T, Tiggesbäumker J, Meiwes-Broer KH, Lemell C, Burgdörfer J, Levine RD, Remacle F, Kling MF. Coherent electronic wave packet motion in C(60) controlled by the waveform and polarization of few-cycle laser fields. Phys Rev Lett 2015; 114:123004. [PMID: 25860740 DOI: 10.1103/physrevlett.114.123004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Indexed: 05/20/2023]
Abstract
Strong laser fields can be used to trigger an ultrafast molecular response that involves electronic excitation and ionization dynamics. Here, we report on the experimental control of the spatial localization of the electronic excitation in the C_{60} fullerene exerted by an intense few-cycle (4 fs) pulse at 720 nm. The control is achieved by tailoring the carrier-envelope phase and the polarization of the laser pulse. We find that the maxima and minima of the photoemission-asymmetry parameter along the laser-polarization axis are synchronized with the localization of the coherent electronic wave packet at around the time of ionization.
Collapse
Affiliation(s)
- H Li
- Max Planck Institute of Quantum Optics, Garching D-85748, Germany
- Department of Physics, Ludwig-Maximilians-Universität München, Garching D-85748, Germany
- J.R. MacDonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506, USA
| | - B Mignolet
- Department of Chemistry, University of Liège, Liège B-4000, Belgium
| | - G Wachter
- Institute for Theoretical Physics, Vienna University of Technology, Vienna A-1040, Austria
| | - S Skruszewicz
- Institute of Physics, Universität Rostock, Rostock D-18051, Germany
| | - S Zherebtsov
- Max Planck Institute of Quantum Optics, Garching D-85748, Germany
- Department of Physics, Ludwig-Maximilians-Universität München, Garching D-85748, Germany
| | - F Süssmann
- Max Planck Institute of Quantum Optics, Garching D-85748, Germany
- Department of Physics, Ludwig-Maximilians-Universität München, Garching D-85748, Germany
| | - A Kessel
- Max Planck Institute of Quantum Optics, Garching D-85748, Germany
| | - S A Trushin
- Max Planck Institute of Quantum Optics, Garching D-85748, Germany
| | - Nora G Kling
- Department of Physics, Ludwig-Maximilians-Universität München, Garching D-85748, Germany
- J.R. MacDonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506, USA
| | - M Kübel
- Max Planck Institute of Quantum Optics, Garching D-85748, Germany
- Department of Physics, Ludwig-Maximilians-Universität München, Garching D-85748, Germany
| | - B Ahn
- Max Planck Institute of Quantum Optics, Garching D-85748, Germany
- Physics Department, CASTECH, POSTECH, Pohang, Kyungbuk 790-784, Republic of Korea
- Max Planck Center for Attosecond Science, Max Planck POSTECH/KOREA Research Initiative, Pohang 790-784, Republic of Korea
| | - D Kim
- Physics Department, CASTECH, POSTECH, Pohang, Kyungbuk 790-784, Republic of Korea
- Max Planck Center for Attosecond Science, Max Planck POSTECH/KOREA Research Initiative, Pohang 790-784, Republic of Korea
| | - I Ben-Itzhak
- J.R. MacDonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506, USA
| | - C L Cocke
- J.R. MacDonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506, USA
| | - T Fennel
- Institute of Physics, Universität Rostock, Rostock D-18051, Germany
| | - J Tiggesbäumker
- Institute of Physics, Universität Rostock, Rostock D-18051, Germany
| | - K-H Meiwes-Broer
- Institute of Physics, Universität Rostock, Rostock D-18051, Germany
| | - C Lemell
- Institute for Theoretical Physics, Vienna University of Technology, Vienna A-1040, Austria
| | - J Burgdörfer
- Institute for Theoretical Physics, Vienna University of Technology, Vienna A-1040, Austria
- Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen H-4001, Hungary
| | - R D Levine
- Fritz Haber Center for Molecular Dynamics, Hebrew University of Jerusalem, Jerusalem 91904, Israel
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, USA
| | - F Remacle
- Department of Chemistry, University of Liège, Liège B-4000, Belgium
| | - M F Kling
- Max Planck Institute of Quantum Optics, Garching D-85748, Germany
- Department of Physics, Ludwig-Maximilians-Universität München, Garching D-85748, Germany
- J.R. MacDonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506, USA
| |
Collapse
|
17
|
Okada H, Butterfield L, Hamilton R, Ahn B, Kohanbash G, Drappatz J, Engh J, Amankulor N, Lively M, Chan M, Salazar A, Shaw E, Potter D, Lieberman F. IT-23 * INDUCTION OF ROBUST TYPE-1 CD8+ T-CELL RESPONSES IN WHO GRADE II LOW-GRADE GLIOMA PATIENTS RECEIVING PEPTIDE-BASED VACCINES IN COMBINATION WITH POLY-ICLC. Neuro Oncol 2014. [DOI: 10.1093/neuonc/nou258.21] [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: 11/12/2022] Open
|
18
|
Kohanbash G, Straw E, Averick A, Ahn B, Smith-Cohn M, Ohkuri T, Kosaka A, Okada H. IT-17 * ONO-AE3-208 INHIBITS MYELOID-DERIVED SUPPRESSOR CELLS AND GLIOMA GROWTH. Neuro Oncol 2014. [DOI: 10.1093/neuonc/nou258.15] [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: 11/13/2022] Open
|
19
|
Lee S, Son S, Song B, Jeong S, Chae Y, Ahn B, Lee J. Whole-Body Metabolic Tumor Volume on F-18 Fdg Pet/Ct As a Prognostic Factor in Breast Cancer Patients with Distant Metastasis. Ann Oncol 2014. [DOI: 10.1093/annonc/mdu329.18] [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: 11/13/2022] Open
|
20
|
Hong C, Cho H, Lee D, Ahn B. SU-E-I-36: Investigation of Geometric Image Distortion Correction Using the Bricks Phantom for Multi-Modality Imaging. Med Phys 2014. [DOI: 10.1118/1.4887984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
21
|
Roberts BM, Frye GS, Ahn B, Ferreira LF, Judge AR. Cancer cachexia decreases specific force and accelerates fatigue in limb muscle. Biochem Biophys Res Commun 2013; 435:488-92. [PMID: 23673294 DOI: 10.1016/j.bbrc.2013.05.018] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 05/03/2013] [Indexed: 11/26/2022]
Abstract
Cancer cachexia is a complex metabolic syndrome that is characterized by the loss of skeletal muscle mass and weakness, which compromises physical function, reduces quality of life, and ultimately can lead to mortality. Experimental models of cancer cachexia have recapitulated this skeletal muscle atrophy and consequent decline in muscle force generating capacity. However, more recently, we provided evidence that during severe cancer cachexia muscle weakness in the diaphragm muscle cannot be entirely accounted for by the muscle atrophy. This indicates that muscle weakness is not just a consequence of muscle atrophy but that there is also significant contractile dysfunction. The current study aimed to determine whether contractile dysfunction is also present in limb muscles during severe Colon-26 (C26) carcinoma cachexia by studying the glycolytic extensor digitorum longus (EDL) muscle and the oxidative soleus muscle, which has an activity pattern that more closely resembles the diaphragm. Severe C-26 cancer cachexia caused significant muscle fiber atrophy and a reduction in maximum absolute force in both the EDL and soleus muscles. However, normalization to muscle cross sectional area further demonstrated a 13% decrease in maximum isometric specific force in the EDL and an even greater decrease (17%) in maximum isometric specific force in the soleus. Time to peak tension and half relaxation time were also significantly slowed in both the EDL and the solei from C-26 mice compared to controls. Since, in addition to postural control, the oxidative soleus is also important for normal locomotion, we further performed a fatigue trial in the soleus and found that the decrease in relative force was greater and more rapid in solei from C-26 mice compared to controls. These data demonstrate that severe cancer cachexia causes profound muscle weakness that is not entirely explained by the muscle atrophy. In addition, cancer cachexia decreases the fatigue resistance of the soleus muscle, a postural muscle typically resistant to fatigue. Thus, specifically targeting contractile dysfunction represents an additional means to counter muscle weakness in cancer cachexia, in addition to targeting the prevention of muscle atrophy.
Collapse
Affiliation(s)
- B M Roberts
- 1225 Center Drive, HPNP Building Room 1142, Department of Physical Therapy, University of Florida, Gainesville, FL 32610, USA
| | | | | | | | | |
Collapse
|
22
|
Chung EY, Kim BH, Lee IJ, Roh E, Oh SJ, Kwak JA, Lee YR, Ahn B, Nam SY, Han SB, Kim Y. The benzoxathiolone LYR-71 down-regulates interferon-gamma-inducible pro-inflammatory genes by uncoupling tyrosine phosphorylation of STAT-1 in macrophages. Br J Pharmacol 2010; 158:1971-81. [PMID: 19922538 DOI: 10.1111/j.1476-5381.2009.00496.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND AND PURPOSE Benzoxathiolone derivatives have shown anti-inflammatory and immunomodulatory potential in acne and psoriatic disorders. However, little is known about the molecular basis for these pharmacological effects. In this study, we decided to investigate the anti-inflammatory actions of a benzoxathiolone derivative LYR-71, 6-methyl-2-propylimino-6,7-dihydro-5H-benzo[1,3]oxathiol-4-one, in interferon (IFN)-gamma-activated macrophages. EXPERIMENTAL APPROACH RAW 264.7 macrophages or primary macrophages, derived from bone marrow of C3H/HeJ mice, were stimulated with IFN-gamma in the presence of LYR-71. Nitric oxide (NO) or chemokine production was measured by Griess reaction or enzyme-linked immunosorbent assay. RAW 264.7 cells were used to examine the molecular mechanisms of LYR-71 in modulating IFN-gamma-induced inflammatory responses. KEY RESULTS LYR-71 down-regulated IFN-gamma-induced transcription of inducible NO synthase, IFN-gamma-inducible protein-10 and the monokine induced by IFN-gamma genes in macrophages. This effect was mediated by uncoupling tyrosine phosphorylation of the signal transducer and activator of transcription (STAT)-1 in response to IFN-gamma. LYR-71 directly inhibited the in vitro catalytic activity of Janus kinase (JAK)-2. Further, the inhibitory actions of LYR-71 on IFN-gamma-induced STAT-1 phosphorylation and NO production were consistently abolished in the presence of peroxyvanadate, implying another target dependent on protein tyrosine phosphatase. CONCLUSIONS AND IMPLICATIONS Taken together, LYR-71 could restrain IFN-gamma-induced inflammatory responses through uncoupling the tyrosine phosphorylation of STAT-1, an activation index of JAK-STAT-1 signalling, in macrophages. These results may provide a molecular mechanism underlying anti-inflammatory actions shown by benzoxathiolone derivatives.
Collapse
Affiliation(s)
- E-Y Chung
- College of Pharmacy, Chungbuk National University, Cheongju, Korea
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Dauch AL, Ahn B, Watson AK, Seguin P, Jabaji-Hare SH. Molecular Monitoring of Wild-Type and Genetically Engineered Colletotrichum coccodes Biocontrol Strains In Planta. Plant Dis 2006; 90:1504-1510. [PMID: 30780968 DOI: 10.1094/pd-90-1504] [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: 06/09/2023]
Abstract
Two strains of Colletotrichum coccodes, the wild type (DAOM 183088) and T-20a, engineered with the necrosis- and ethylene-inducing peptide (NEP1) gene for hypervirulence on velvetleaf (Abutilon theophrasti, Medik.), were monitored in planta for the first 2 weeks after infection. Real-time quantitative polymerase chain reaction (QPCR) was used to assess the extent of colonization of both strains on velvetleaf using SYBR Green chemistry. Quantification of both strains was successful as soon as the conidia were sprayed on the leaves and up to 14 days after infection. The increase in fungal DNA amounts corroborated with the appearance of necrotic lesions on velvetleaf leaves infected with the wild-type strain. The wild-type C. coccodes was more efficient at infecting velvetleaf than the transgenic T-20a strain. In addition, detection of host DNA allowed us to quantitatively monitor the decrease in plant DNA amounts in response to wild-type strain infection. Expression of the NEP1 transgene by conventional retro-transcription (RT)-PCR was absent from T-20a growing on either V8 agar or in planta, suggesting that the gene may be silenced. The application of QPCR to monitor fungal growth was proven to detect the target organisms in planta prior to the appearance of symptoms.
Collapse
Affiliation(s)
- A L Dauch
- Department of Plant Science, Macdonald Campus of McGill University, Sainte-Anne-de-Bellevue, Québec, H9X 3V9, Canada
| | - B Ahn
- Department of Plant Science, Macdonald Campus of McGill University, Sainte-Anne-de-Bellevue, Québec, H9X 3V9, Canada
| | - A K Watson
- Department of Plant Science, Macdonald Campus of McGill University, Sainte-Anne-de-Bellevue, Québec, H9X 3V9, Canada
| | - P Seguin
- Department of Plant Science, Macdonald Campus of McGill University, Sainte-Anne-de-Bellevue, Québec, H9X 3V9, Canada
| | - S H Jabaji-Hare
- Department of Plant Science, Macdonald Campus of McGill University, Sainte-Anne-de-Bellevue, Québec, H9X 3V9, Canada
| |
Collapse
|
24
|
Nam KT, Oh SY, Ahn B, Kim YB, Jang DD, Yang KH, Hahm KB, Kim DY. Decreased Helicobacter pylori associated gastric carcinogenesis in mice lacking inducible nitric oxide synthase. Gut 2004; 53:1250-5. [PMID: 15306579 PMCID: PMC1774181 DOI: 10.1136/gut.2003.030684] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Revised: 01/26/2004] [Accepted: 02/19/2004] [Indexed: 12/27/2022]
Abstract
BACKGROUND AND AIMS Overproduction of nitric oxide via inducible nitric oxide synthase (iNOS) is suggested to be a significant pathogenic factor in Helicobacter pylori induced gastritis. The purpose of this study was to examine the role of iNOS in H pylori associated gastric carcinogenesis. METHODS Two types of mice were used in this study: iNOS deficient mice (iNOS-/-) and wild-type littermates. Gastric cancer was generated in mice using a combination treatment comprising N-methyl-N-nitrosourea administration and H pylori infection. Fifty weeks after treatment, tumours in gastric tissues from both types of mice were examined using histopathology, immunohistochemistry, and immunoblotting for iNOS and 3-nitrotyrosine. RESULTS The overall incidence of gastric cancer at week 50 was significantly lower in iNOS-/- compared with iNOS wild-type mice (p<0.05). When analysed according to tumour pathology, the incidence of gastric adenocarcinoma was significantly lower in iNOS-/- compared with iNOS wild-type mice (p<0.05). Immunostaining for iNOS was clearly observed in adenocarcinoma cells of iNOS wild-type mice, and was characterised by a strong cytoplasmic expression pattern. 3-Nitrotyrosine was expressed mostly in the area of the lamina propria of gastritis and adenoma lesions in iNOS wild-type mice. Immunoblotting analyses showed that iNOS and 3-nitrotyrosine were also expressed in both adenoma and adenocarcinoma tissues from iNOS wild-type mice. iNOS and 3-nitrotyrosine expression was greater in tumour tissues than in non-tumour tissues. CONCLUSIONS These findings suggest that iNOS contributes to H pylori associated gastric carcinogenesis in mice.
Collapse
Affiliation(s)
- K T Nam
- Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, San 56-1, Shillim-dong, Kwanak-gu, Seoul 151-742, Korea
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Abstract
AIMS To evaluate the clinical efficacy of membrane tube implant made of expanded polytetrafluoroethylene (e-PTFE, Gore-Tex) membrane and silicone tube in treating refractory glaucoma. METHODS A retrospective chart review was performed on 43 eyes of 40 patients who underwent glaucoma tube shunt implant surgery using double layered e-PTFE membrane and silicone tube to treat refractory glaucoma. The surgeries were performed from May 1991 to September 1995, and the subjects were patients with terminal glaucoma without useful vision on the study eye. RESULTS The mean follow up period was 32.9 months. The Kaplan-Meier survival for intraocular pressure (IOP) control (IOP between 6 and 21mm Hg without significant complication) was 80.9% at 1 year, 73.9% at 2 years, and 62.2% at 3 years after surgery. After excluding three eyes of three patients who were dropped within 3 months after surgery and did not have any serious complication or problem in IOP control, the average preoperative IOP was 42.5 (SD 14.6) mm Hg and IOP on the last visit was 17.3 (10.2) mm Hg (p = 0.000, n = 40). The number of antiglaucoma medications before surgery (2.2 (0.6)) was reduced to 0.5 (0.8) on the last visit (p = 0.000). The IOP was controlled within the range of 6-21 mm Hg in 26 eyes (65.0%). In the remaining 14 eyes (35%), we could not control the IOP or additional surgery was needed to control the IOP or to treat severe complications. Two cases of endophthalmitis and three of phthisis were found as serious complications. The other complications were similar to those of other commercially available glaucoma implants. CONCLUSION A comparable clinical result was obtained with this new implant as with the other commercially available implants. This implant with a thin and non-rigid reservoir has a potential to reduce some complications associated with the large volume and rigid consistency of the other implants, although it is not yet proved. This membrane tube implant may be considered as another substitute in the surgery of refractory glaucoma.
Collapse
Affiliation(s)
- C Kim
- Department of Ophthalmology, College of Medicine, Chungnam National University, Taejon, South Korea.
| | | | | | | | | |
Collapse
|
26
|
Ahn B, Ohshima H. Suppression of intestinal polyposis in Apc(Min/+) mice by inhibiting nitric oxide production. Cancer Res 2001; 61:8357-60. [PMID: 11731407] [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: 02/22/2023]
Abstract
Inducible nitric oxide synthase (iNOS) was shown to be expressed in normal mucosa and adenoma of small and large intestines of Apc(Min/+) mice by reverse transcription-PCR and immunohistochemistry. Administration of the iNOS inhibitor aminoguanidine (1.5 g/liter) in drinking water or an L-arginine-deficient diet to Apc(Min/+) mice resulted in a significant decrease in adenoma development in the small but not the large intestine. Similarly, iNOS-gene knockout Apc(Min/+) mice (Apc(Min/+) iNOS(-/-) or Apc(Min/+) iNOS(-/+)) developed significantly fewer adenomas in both small and large intestines than Apc(Min/+) iNOS(+/+) mice. These results suggest that iNOS-selective inhibitors could be used as a potential chemopreventive agent for colorectal cancers.
Collapse
Affiliation(s)
- B Ahn
- Department of Pathology, National Institute of Toxicological Research, Korea Food and Drug Administration, Seoul, 122-704, Korea
| | | |
Collapse
|
27
|
Kang JS, Kim DJ, Ahn B, Nam KT, Kim KS, Choi M, Jang DD. Post-initiation treatment of Indole-3-carbinol did not suppress N-methyl-N-nitrosourea induced mammary carcinogenesis in rats. Cancer Lett 2001; 169:147-54. [PMID: 11431103 DOI: 10.1016/s0304-3835(01)00551-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The consumption of cruciferous vegetables (the Family of Cruciferae) such as cabbage, broccoli and Brussels sprouts has been shown to have cancer chemopreventive effects in humans and experimental animals. Indole-3-carbinol (I3C), one component of cruciferous vegetables, has been shown to exert cancer chemopreventive influence in liver, colon, and mammary tissue when given before or concurrent with exposure to a carcinogen. However in some reports, there has been evidence that consumption of I3C after carcinogen treatment might be associated with tumor promotion in some tissues. There have been no reports, to our knowledge, of post-initiation effects of I3C in the N-methyl-N-nitrosourea (MNU)-induced mammary tumor model in rats. Our studies were performed to examine this question. Ninety-six, 4-week-old female Sprague-Dawley rats were randomly divided into five groups. The animals of groups 1, 2 and 3 received an intraperitoneal injection of MNU at the age of 50 days. The animals of groups 4 and 5 were injected with saline only at the same time. Animals of groups 1 and 2 were given diet containing 100 ppm and 300 ppm I3C from week 1 until week 25 after MNU treatment. The animals of group 4 were given basal diet containing 300 ppm I3C without MNU treatment. All animals were killed at week 25. The incidences of mammary tumors in the groups 1, 2 and 3 were 95.8% (23/24), 83.3% (20/24) and 82.4% (28/34), respectively. The average number of tumors in the tumor bearing rats of the MNU and I3C 300 ppm group (group 2; 3.85+/-0.63) was higher than that in the MNU alone group (group 3; 2.46+/-0.31). These results represented that exposure to I3C after carcinogen treatment did not suppress development of mammary tumors.
Collapse
Affiliation(s)
- J S Kang
- Department of Pathology, National Institute of Toxicology Research, Korea Food and Drug Administration, Nokbeon-dong, Eunpyung-gu, 122-704, Seoul, South Korea.
| | | | | | | | | | | | | |
Collapse
|
28
|
Abstract
Eight esters of 2-(1-hydroxyalkyl)-1,4-dihydroxy-9,10-anthraquinone with melphalan were prepared and tested for their antitumor activity (S-180) and cytotoxicity. 2-[1-[4-(p-Bis(2-chloroethyl)-aminophenyl)-butanoyloxy]methyl]-1,4-dihydroxy-9,10-anthraquinone and 2-[1-[4-(p-bis(2-chloroethyl)-aminophenyl)-butanoyloxy]ethyl]-1,4-dihydroxy-9,10-anthraquinone showed remarkable antitumor activity (T/C, 265 and 272%).
Collapse
Affiliation(s)
- G Jin
- College of Pharmacy, Yanbian University, Yanji, 133000, Jilin, China
| | | | | |
Collapse
|
29
|
Kim DJ, Kang JS, Ahn B, Kim KS, Park KH, Choi KS, Surh YJ, Kim ND. Chemopreventive effect of 2-(allylthio)pyrazine (2-AP) on rat colon carcinogenesis induced by azoxymethane (AOM). Cancer Lett 2001; 166:125-33. [PMID: 11311484 DOI: 10.1016/s0304-3835(01)00408-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
An investigation was conducted to assess the chemopreventive effects of 2-(allylthio)pyrazine (2-AP), synthesized for potential use as a chemopreventive agent, after administration during the pre-initiation and post-initiation stages in a rat colon carcinogenesis model with azoxymethane (AOM). One hundred, 5-week-old, male F344 rats were randomly divided into two experiments (n = 50 each). Experiment 1 rats were randomly divided into three groups: Group 1 rats were pre-treated with 2-AP (25 or 50 mg/kg body weight, 3 consecutive days through the route of intragastric intubations) before AOM (20 mg/kg body weight, single subcutaneous (s.c.) injection) initiation. Group 2 rats were treated with AOM alone. Group 3 rats were given 2-AP alone without AOM initiation. The animals were killed at the end of each experiment (week 5) and the aberrant crypt foci (ACF) of the colonic mucosa were assessed after staining with methylene blue. Experiment 2 rats were randomly divided into three groups: Group 1 rats were given 2-AP (10, 25 or 50 mg/kg body weight, five-times intragastric intubations per week for 5 weeks from week 3) after AOM (15 mg/kg body weight, three s.c. injections) initiation for 2 weeks. Group 2 rats were treated with AOM alone. Group 3 rats were given 2-AP alone without AOM initiation. The animals were killed at the end of the experiment (week 8) and the ACF of the colonic mucosa were quantified. Total numbers of ACF/colon in Group 1 rats (pre-treated with 2-AP) tended to decrease (2-AP, 50 mg/kg body weight) or increase (2-AP, 100 mg/kg body weight) depending on the dose level. Total numbers of ACF/colon in Group 1 rats (treated with AOM followed by 2-AP, all subgroups; 160.8 +/- 38.0; 161.8 +/- 38.1; 137.1 +/- 48.4) were decreased significantly compared with the values in Group 2 rats (AOM alone; 214.8 +/- 48.1) (P < 0.05 or 0.01). The highest dose group (2-AP, 50 mg/kg body weight) had the lowest levels of total numbers of ACF/colon among the three subgroups. Total numbers of aberrant crypts (AC)/colon of the highest dose group (340.1+/- 117.9) decreased significantly compared with the value for Group 2 rats (AOM alone; 545.1 +/- 38.3). These results thus suggest that 2-AP may have potential as a chemopreventive agent against rat colon carcinogenesis after administration of AOM during the post-initiation stage.
Collapse
Affiliation(s)
- D J Kim
- Structural BioInformatics and Cancer Prevention Laboratory, College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University, 48 Gaeshin-dong, Heungduk-gu, 361-763, Cheongju, South Korea.
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Jin SG, Choi JH, Ahn B, O'Connor TR, Mar W, Lee CS. Excision repair of adozelesin-N3 adenine adduct by 3-methyladenine-DNA glycosylases and UvrABC nuclease. Mol Cells 2001; 11:41-7. [PMID: 11266119] [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: 02/19/2023] Open
Abstract
Adozelesin is a synthetic analog of the antitumor antibiotic CC-1065, which alkylates the N3 of adenine in the minor groove in a sequence-selective manner. Since the cytotoxic potency of a DNA alkylating agent can be modulated by DNA excision repair system, we investigated whether nucleotide excision repair (NER) and base excision repair (BER) enzymes are able to excise the bulky DNA adduct induced by adozelesin. The UvrABC nuclease and 3-methyladenine-DNA glycosylase, that exhibit a broad spectrum of substrate specificity, were selected as typical NER and BER enzymes, respectively. The adozelesin-DNA adduct was first formed in the radiolabeled restriction DNA fragment and its excision by purified repair enzymes was monitored on a DNA sequencing gel. The treatment of the DNA adduct with a purified UvrABC nuclease and sequencing gel analysis of cleaved DNA showed that UvrABC nuclease was able to incise the adozelesin adduct. The incision site corresponded to the general nuclease incision site. Excision of this adduct by 3-methyladenine-DNA glycosylases was determined following the treatment of the DNA adduct with a homogeneous recombinant bacterial, rat and human 3-methyladenine-DNA glycosylases. Abasic sites generated by DNA glycosyalses were cleaved by the associated lyase activity of the E. coli formamidopyrimidine-DNA glycosylase (Fpg). Resolution of cleaved DNA on a sequencing gel showed that the DNA glycosylase from different sources could not release the N3-adenine adducts. A cytotoxicity assay using E. coli repair mutant strains showed that E. coli mutant strains defective in the uvrA gene were more sensitive to cell killing by adozelesin than E. coli mutant strain defective in the alkA gene or the wild type. These results suggest that the NER pathway seems to be the major excision repair system in protecting cells from the cytotoxicity of adozelesin.
Collapse
Affiliation(s)
- S G Jin
- Department of Biochemistry and Institute of Natural Sciences, College of Natural Sciences, Yeungnam University, Kyongsan, Korea
| | | | | | | | | | | |
Collapse
|
31
|
Abstract
The dual-incision nature of the reaction of UV-irradiated DNA catalyzed by the UvrABC complex potentially leads to excision of a damaged fragment. However, neither fragment release under nondenaturing conditions nor the UvrBC proteins are turned over. The addition of the UvrD protein to the incised DNA-UvrBC complex results in excision of the incised damaged strand and in the turnover of the UvrC protein. In an effort to better understand the involvement of UvrD in the excision step, immunoprecipitation was used to detect interacting proteins with UvrD in the DNA repair. In this communication, it is shown that UvrA and UvrB are precipitated with UvrD in solution but the UvrAB complex is not. In the incision complex, UvrB could be precipitated and the preincubation of UvrD with UvrB revealed an inhibitory effect on the turnover of the incision complex. These data imply that UvrB in the incision complex seems to recruit UvrD to the 3' incised site of the incised strand by protein-protein interaction and to allow initiation of unwinding by UvrD from the resulting nick in a 3' to 5' direction.
Collapse
Affiliation(s)
- B Ahn
- Department of Molecular Microbiology, University of Ulsan, Korea.
| |
Collapse
|
32
|
Kwon Y, Kang M, Ahn C, Han H, Ahn B, Lee J. Effect of high or low frequency electroacupuncture on the cellular activity of catecholaminergic neurons in the brain stem. ACUPUNCTURE ELECTRO 2000; 25:27-36. [PMID: 10830973 DOI: 10.3727/036012900816356235] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Although the opioid system plays a pivotal role in the analgesic effect of electroacupuncture (EA), it has been suggested that other peptidergic systems also may be involved in the therapeutic effect of EA. Among several peptides for EA-induced analgesia, catecholamine (CA) is associated with the descending pain inhibitory system. We evaluated whether the different frequencies of EA modified the cellular activity of central CA synthesizing neurons using double labeling immunohistochemistry between Fos-like immunoreactive (FLI) neurons and dopamine-beta-hydroxylase (DBH)/tyrosine hydroxylase (TH)-positive neurons. We observed that different frequencies of EA increased the number of FLI neurons in catecholaminergic neurons, such as the dorsal raphe (DR), hypothalamic arcuate nucleus (Arc), locus coeruleus (LC), A5 noradrenaline cells (A5), and A7 noradrenaline cells (A7). In addition, different frequencies of EA significantly increased the ratio of colocalization between FLI neurons and TH positive neurons in DR, LC and Arc. Only low frequency EA increased the neuronal activity in Arc. The ratio of double labeling between FLI and DBH positive neurons was also elevated at both LC and A5. These data demonstrate that different frequencies of EA increase the cellular activity of central CA synthesizing neurons, suggesting that the CA system plays an important role in EA-induced analgesia.
Collapse
Affiliation(s)
- Y Kwon
- Department of Veterinary Physiology, College of Veterinary Medicine, Seoul National University, Suwon, South Korea
| | | | | | | | | | | |
Collapse
|
33
|
Abstract
Escherichia coli nucleotide excision repair (NER) is responsible for removing bulky DNA adducts by dual incisions of the UvrABC endonuclease. Although the activity of the UvrAB complex which can induce DNA conformational change is employed in NER, the involvement of DNA topology and DNA topoisomerases remains unclear. We examined the effect of topoisomerase inhibitions on a NER in vivo system. The repair analysis of intracellular plasmid revealed that the DNA damage on positive supercoils generated by gyrase inhibition remained unrepaired, whereas the DNA damage was repaired in topoisomerase I mutants. These results suggest that DNA topology affects the NER process and the removal of positive supercoils by gyrase is vital for the efficiency of the E. coli NER system.
Collapse
Affiliation(s)
- J Y Park
- Department of Molecular Microbiology, University of Ulsan, Nam-Ku MooGeo-Dong, 680-749, Ulsan, South Korea
| | | |
Collapse
|
34
|
Lee N, Ahn B, Jung SB, Kim YG, Kim H, Park WJ. Conformation-dependent antibody response to Pseudomonas aeruginosa outer membrane proteins induced by immunization in humans. FEMS Immunol Med Microbiol 2000; 27:79-85. [PMID: 10617794 DOI: 10.1111/j.1574-695x.2000.tb01415.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Outer membrane proteins (OMPs) of pathogenic bacteria have been used as protective antigens in developing bacterial vaccines. In the present study, we compared the antibody responses to a Pseudomonas aeruginosa OMP vaccine elicited in humans and rabbits by immunization. Immunization with the vaccine induced high titers of serum IgG antibody both in rabbits and humans but reactivities of the induced antibodies with the OMPs were different. The rabbit immune sera recognized most of the OMPs in the vaccine both in immunoblot and immunoprecipitation analyses. In contrast, a great variation in band pattern and intensity was observed among the human immune sera in immunoblot analysis, but not in immunoprecipitation analysis. Denaturation of the OMPs did not affect the binding activity of the rabbit immune sera as determined by ELISA, but substantially reduced those of the human immune sera and anti-OMP IgG purified from a pooled normal human plasma. These data suggest that antibody response to P. aeruginosa OMPs elicited by immunization in humans is mainly directed against discontinuous or conformation-dependent epitopes, which should be taken into account in developing vaccines, especially for OMP-derived synthetic peptides.
Collapse
Affiliation(s)
- N Lee
- R and D Center of Bioscience, Institute of Science and Technology, Cheiljedang Corp., Ichon, Kyonggi, South Korea.
| | | | | | | | | | | |
Collapse
|
35
|
Ahn B, Lee SS. Effect of microstructure of low carbon steels on ultrasonic attenuation. IEEE Trans Ultrason Ferroelectr Freq Control 2000; 47:620-629. [PMID: 18238589 DOI: 10.1109/58.842049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The ultrasonic attenuation in low carbon steel with 0.04 wt% C to 0.80 wt% C was measured over a frequency range of 5 to 15 MHz, and the effects of the carbon content and normalizing temperature were analyzed. In pure iron, the attenuation is determined from the average grain size, which increases as the normalizing temperature increases; there is a noticeable effect caused by a few large grains. In the case of the hypoeutectoid steels, the proeutectoid ferrite grain, the size of which depends on prior austenite grain size, acts as the main scatterer. The prior austenite grain size increases as the carbon content decreases and the normalizing temperature increases. The colony is responsible for scattering in the eutectoid steel; scattering by pearlite is greater than that by ferrite.
Collapse
Affiliation(s)
- B Ahn
- NDE Group, Korea Res. Inst. of Stand. and Sci., Taejon, Korea.
| | | |
Collapse
|
36
|
Ahn B, Han BS, Kim DJ, Ohshima H. Immunohistochemical localization of inducible nitric oxide synthase and 3-nitrotyrosine in rat liver tumors induced by N-nitrosodiethylamine. Carcinogenesis 1999; 20:1337-44. [PMID: 10383909 DOI: 10.1093/carcin/20.7.1337] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Human liver cancers have been associated mainly with chronic inflammations such as viral hepatitis B or C. This suggests that prolonged cell damage by chronic inflammation is critical in cancer development. Overproduction of nitric oxide (NO.) and its derivative (NOx, peroxynitrite) has been implicated as a cause of tissue damage by inflammation, thus contributing to tumor promotion. We have demonstrated the expression of the inducible isoform of nitric oxide synthase (iNOS) and 3-nitrotyrosine, a marker of peroxynitrite formation, by immunohistochemistry in preneoplastic and neoplastic rat liver tissues induced by continuous infusion of N-nitrosodiethylamine with mini-pumps. The preneoplastic lesions were characterized by proliferation of phenotypically altered hepatic foci (PAHF), dysplastic hepatocytes and oval cells. Histologically, the tumors were hepatocellular carcinomas (HCCs) of trabecular, (pseudo)glandular and solid types with or without cholangiocellular involvement. iNOS was located mainly in oval cells, capillary endothelial and muscular cells, epithelia of cholangiomas and glandular HCCs. 3-Nitrotyrosine was observed in the cytoplasms of PAHF and dysplastic hepatocytes in preneoplasias and in the cytoplasms of some living or apoptotic HCC cells, connective tissues, proteinaceous fluids, sinusoidal endothelia of tumorous hepatocytes and cholangiomas in tumors. From these observations, we suggest that: (i) chronic tissue damage by chemical carcinogens may act to induce iNOS and peroxynitrite formation; (ii) oval cells play a key role in development and/or growth of tumor tissues by producing NO. via iNOS, which may also cause tissue damage by peroxynitrite; (iii) iNOS can be considered as a phenotypic marker in cells of oval cell lineage and neovascularized capillaries in tumor tissues.
Collapse
Affiliation(s)
- B Ahn
- Department of Pathology, National Institute of Toxicology Research, Korea Food and Drug Administration, 5 Nokbun-Dong, Eunpyung-Ku, Seoul 122-704, Korea
| | | | | | | |
Collapse
|
37
|
Abstract
Cephalosporin antibiotics caused the formation of carbonyl groups in the plasma proteins both in vivo and in vitro. After the administration of either moxalactam (3 g/day) or cefotaxime (2 g/day) to patients for 7 days, the carbonyl contents in the plasma proteins increased markedly as determined by the 2,4-dinitrophenylhydrazine (DNPH) method. The increase in protein carbonyl groups was also visualized by the conjugation of plasma proteins with fluorescein thiosemicarbazide (FTSC) and subsequent electrophoresis. When blood plasma was incubated with cephalosporins, most of the cephalosporins tested caused the carbonyl formation in plasma proteins to significant degrees in a concentration-dependent manner. Although a number of plasma proteins and other nonplasma proteins could be modified by cephalosporins in vitro, the plasma albumin was most markedly modified in vivo as well as in vitro. The protein carbonyl formation by cephalosporins was inhibited by ascorbic acid, reduced glutathione, and cysteine, but it was not affected by FeSO4, CuSO4, desferrioxamine, EDTA, catalase, superoxide dismutase, uric acid, alpha-tocopherol, and mannitol. Sodium borohydride, when applied to moxalactam-treated plasma proteins, markedly reduced the reactivities of the protein with FTSC or DNPH, indicating that the observed reactivities of the cephalosporin-treated proteins toward FTSC or DNPH are actually due to the protein carbonyl groups. These data suggest that cephalosporins can oxidatively modify proteins in blood plasma and other tissues and that the oxidative modification of proteins may be involved in the adverse reactions observed frequently following cephalosporin therapy.
Collapse
Affiliation(s)
- Y Jung
- Department of Biochemistry, Chonnam University Medical School, Kwangju, Korea
| | | | | | | | | | | |
Collapse
|
38
|
Kim DJ, Han BS, Ahn B, Hasegawa R, Shirai T, Ito N, Tsuda H. Enhancement by indole-3-carbinol of liver and thyroid gland neoplastic development in a rat medium-term multiorgan carcinogenesis model. Carcinogenesis 1997; 18:377-81. [PMID: 9054632 DOI: 10.1093/carcin/18.2.377] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The modification potential of indole-3-carbinol (I3C), a naturally occurring compound found in cruciferous vegetables, on neoplastic development was assessed using a rat medium-term multiorgan carcinogenesis model. One-hundred male Sprague-Dawley (SD) rats were randomly divided into three groups and sequentially treated with diethylnitrosamine (DEN; 100 mg/kg b.w., a single i.p.), N-methyl-N-nitrosourea (MNU; 20 mg/kg b.w., four times i.p., at days 5, 8, 11 and 14), and dihydroxy-di-N-propyl-nitrosamine (DHPN; 0.1% in the drinking water during weeks 1 and 3) (DMD treatment; groups 1 and 2) or the vehicles alone (group 3) in the first 3-week initiation period. Animals of groups 1 and 3 were then given diet containing 0.25% I3C from week 4 until week 24, followed by a return to basal diet for 28 weeks, and subgroups were killed at weeks 24 and 52. I3C caused significant increases in both number (no./cm2) and area (mm2/cm2) of glutathione S-transferase placental form (GST-P)-positive liver cell foci assessed at week 24 of the experiment (P<0.01, 0.001). The incidence of hepatocellular adenomas in the DMD and I3C group at week 52 showed a tendency for elevation as compared to the DMD alone group, but this was not statistically significant. The thyroid gland tumour incidences in the DMD and I3C groups were significantly increased compared with the DMD alone group values at week 52 (P<0.01). In conclusion, I3C enhanced liver and thyroid gland neoplastic development when given during the promotion stage in the present rat medium-term multiorgan carcinogenesis model.
Collapse
Affiliation(s)
- D J Kim
- Chemotherapy Division, National Cancer Centre Research Institute, Chuo-ku, Tokyo, Japan
| | | | | | | | | | | | | |
Collapse
|
39
|
Kim DJ, Ahn B, Han BS, Tsuda H. Potential preventive effects of Chelidonium majis L. (Papaveraceae) herb extract on glandular stomach tumor development in rats treated with N-methyl-N'-nitro-N nitrosoguanidine (MNNG) and hypertonic sodium chloride. Cancer Lett 1997; 112:203-8. [PMID: 9066729 DOI: 10.1016/s0304-3835(96)04571-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The modifying effects of Chelidonium majis L. (Papaveraceae) herb extract (CH), an analgesic traditionally prescribed for gastric and duodenal ulcer patients, on gastric tumor development were studied in rats given N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Sixty-four male 6-week-old Wistar rats were used. Group 1 rats were initially given MNNG (200 mg/kg b.w.) by gavage at days 0 and 14 as well as saturated sodium chloride solution (S-NaCl, 1 ml per rat) every 3 days during weeks 0-3 (six times), and then placed on basal diet containing 0.1 or 0.2% CH for 16 weeks from week 4. Rats of Group 2 and 3 were treated with MNNG together with S-NaCl or saline (0.9% NaCl, 1 ml per rat), respectively, timed as in Group 1 but without further treatment. All surviving animals were killed at week 20 and histopathologically investigated. In the glandular stomach, the number of preneoplastic pepsinogen 1 altered pyloric glands (PAPGs) in the MNNG + S-NaCl-->CH (0.1%) group (Group 1) was significantly smaller than in the MNNG + S-NaCl group (Group 2) (P < 0.02). The incidences of forestomach neoplastic lesions (papillomas and squamous cell carcinomas) also showed a tendency to decrease with the CH treatment. The results thus indicate that CH exerts inhibitory effects on glandular stomach carcinogenesis in the rat, so that it may have potential as a chemopreventive agent for stomach cancer in man.
Collapse
Affiliation(s)
- D J Kim
- Chemotherapy Division, National Cancer Center Research Institute, Tokyo, Japan
| | | | | | | |
Collapse
|
40
|
Kovalsky OI, Grossman L, Ahn B. The topodynamics of incision of UV-irradiated covalently closed DNA by the Escherichia coli Uvr(A)BC endonuclease. J Biol Chem 1996; 271:33236-41. [PMID: 8969181 DOI: 10.1074/jbc.271.52.33236] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [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: 02/03/2023] Open
Abstract
The Escherichia coli Uvr(A)BC endonuclease (Uvr(A)BC) initiates nucleotide excision repair of a large variety of DNA damages. The damage recognition and incision steps by the Uvr(A)BC is a complex process utilizing an ATP-dependent DNA helix-tracking activity associated with the UvrA2B1 complex. The latter activity leads to the generation of highly positively supercoiled DNA in the presence of E. coli topoisomerase I in vitro. Such highly positively supercoiled DNA, containing ultraviolet irradiation-induced photoproducts (uvDNA), is resistant to the incision by Uvr(A)BC, whereas the negatively supercoiled and relaxed forms of the uvDNA are effectively incised. The E. coli gyrase can contribute to the above reaction by abolishing the accumulation of highly positively supercoiled uvDNA thereby restoring Uvr(A)BC-catalyzed incision. Eukaryotic (calf thymus) topoisomerase I is able to substitute for gyrase in restoring this Uvr(A)BC-mediated incision reaction. The inability of Uvr(A)BC to incise highly positively supercoiled uvDNA results from the failure of the formation of UvrAB-dependent obligatory intermediates associated with the DNA conformational change. In contrast to Uvr(A)BC, the Micrococcus luteus UV endonuclease efficiently incises uvDNA regardless of its topological state. The in vitro topodynamic system proposed in this study may provide a simple model for studying a topological aspect of nucleotide excision repair and its interaction with other DNA topology-related processes in E. coli.
Collapse
Affiliation(s)
- O I Kovalsky
- Department of Biochemistry, School of Hygiene and Public Health, The Johns Hopkins University, Baltimore, Maryland 21205, USA.
| | | | | |
Collapse
|
41
|
Ostermeyer AG, Runko E, Winkfield B, Ahn B, Moll UM. Cytoplasmically sequestered wild-type p53 protein in neuroblastoma is relocated to the nucleus by a C-terminal peptide. Proc Natl Acad Sci U S A 1996; 93:15190-4. [PMID: 8986786 PMCID: PMC26379 DOI: 10.1073/pnas.93.26.15190] [Citation(s) in RCA: 93] [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] [Received: 06/19/1996] [Accepted: 10/15/1996] [Indexed: 02/03/2023] Open
Abstract
Cytoplasmic sequestration of wild-type p53 protein occurs in a subset of primary human tumors including breast cancer, colon cancer, and neuroblastoma (NB). The sequestered p53 localizes to punctate cytoplasmic structures that represent large protein aggregates. One functional consequence of this blocked nuclear access is impairment of the p53-mediated G1 checkpoint after DNA damage. Here we show that cytoplasmic p53 from NB cells is incompetent for specific DNA binding, probably due to its sequestration. Importantly, the C-terminal domain of sequestered p53 is masked, as indicated by the failure of a C-terminally directed antibody to detect p53 in these structures. To determine (i) which domain of p53 is involved in the aggregation and (ii) whether this phenotype is potentially reversible, we generated stable NB sublines that coexpress the soluble C-terminal mouse p53 peptide DD1 (amino acids 302-390). A dramatic phenotypic reversion occurred in five of five lines. The presence of DD1 blocked the sequestration of wild-type p53 and relocated it to the nucleus, where it accumulated. The nuclear translocation is due to shuttling of wild-type p53 by heteroligomerization to DD1, as shown by coimmunoprecipitation. As expected, the nuclear heterocomplexes were functionally inactive, since DD1 is a dominant negative inhibitor of wild-type p53. In summary, we show that nuclear access of p53 can be restored in NB cells.
Collapse
Affiliation(s)
- A G Ostermeyer
- Department of Pathology, State University of New York at Stony Brook 11794-8691, USA
| | | | | | | | | |
Collapse
|
42
|
Abstract
Transcription when coupled to nucleotide excision repair specifies the location in active genes where preferential DNA repair is to take place. During DNA damage-induced recruitment of RNA polymerase (RNAP), there is a physical association of the beta subunit of Escherichia coli RNAP and the UvrA component of the repair apparatus (G. C. Lin and L. Grossman, submitted for publication). This molecular affinity is reflected in the ability of the RNAP to increase, in a promoter-dependent manner, DNA supercoiling by the UvrAB complex. In the presence of the RNAP, the UvrAB complex is able to bind to promoter regions and to translocate in a 5' to 3' direction along the non-transcribed strand. As a consequence of this helicase-catalyzed translocation, preferential incision of DNA damaged sites occurs downstream on the transcribed strand. Because of the helicase directionality, the initial binding of the UvrAB complex to the transcribed strand would inevitably lead to its collision with the RNAP. These results imply that the RNAP-induced DNA structure in the vicinity of the transcription start site signals a landing or entry site for the UvrAB complex on DNA.
Collapse
Affiliation(s)
- B Ahn
- Department of Biochemistry, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA
| | | |
Collapse
|
43
|
Abstract
Based on the binding of the UvrAB complex to a promoter region in transcription open complexes (Ahn, B., and Grossman, L. (1996) J. Biol. Chem. 271, 21453-21461) and the requirement of a single-stranded region for UvrAB helicase activity, we examined the binding of UvrAB proteins to synthetic bubble or loop regions in duplex DNA and the role of these regions in translocation of the UvrAB complex as well as incision of DNA damage. We found that the UvrAB complex was able to bind to bubble and loop regions with an affinity similar to that for damaged DNA in the absence of RNAP. The preferential recognition and incision of damaged sites by the UvrAB complex was observed downstream of the bubble or loop region in the strand complementary to the strand along which the UvrAB complex translocates. These results imply that the bubble region generated in duplex DNA by RNAP serves as a preferred entry site for the translocation of the UvrAB complex, and that preferential binding and unidirectional translocation of the UvrAB complex predetermine where incision is to occur.
Collapse
Affiliation(s)
- B Ahn
- Department of Biochemistry, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA
| | | |
Collapse
|
44
|
Kim DJ, Han BS, Ahn B, Lee KK, Kang JS, Tsuda H. Promotion potential of tamoxifen on hepatocarcinogenesis in female SD or F344 rats initiated with diethylnitrosamine. Cancer Lett 1996; 104:13-9. [PMID: 8640739 DOI: 10.1016/0304-3835(96)04222-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The liver promotion potential of tamoxifen (TAM), which has been widely used in the treatment of hormone-dependent breast cancers, was investigated using female SD or F344 rat initiated with diethylnitrosamine (DEN). In Experiment 1, 45 newborn female SD rats were administered DEN (100 mg/kg, i.p.) (Groups 1 and 2) or saline (Group 3) 24 h after birth. After weaning at week 3, Groups 1 and 3 were subcutaneously injected with TAM citrate (1 mg/rat per day), suspended in corn oil, in the subscapular region, while Group 2 was given the vehicle alone (s.c.) daily for 9 weeks, and killed at week 12. In Experiment 2, 70 female F344 rats at 7 weeks of age were divided into five groups. All animals were initially given DEN (200 mg/kg i.p.) for initiation. Two weeks later Groups 1-4 were given diets containing 100, 250, 500 ppm TAM, or 500 ppm PB for 6 weeks, respectively, while Group 5 was administered basal diet as a control for the same period. The rats were subjected to two-thirds partial hepatectomy (PH) at week 3 and were killed at week 8. The enhanced development of glutathione S-transferase-placental form (GST-P)-positive liver cell foci after DEN exposure in both newborn SD and adult F344 rat medium-term liver bioassay models (Experiments 1 and 2). This suggests that TAM exerts promotion potential for hepatocarcinogenesis in female rats.
Collapse
Affiliation(s)
- D J Kim
- Chemotherapy Division, National Cancer Center Research Institute, Tokyo, Japan
| | | | | | | | | | | |
Collapse
|
45
|
Kim DJ, Lee KK, Han BS, Ahn B, Bae JH, Jang JJ. Biphasic modifying effect of indole-3-carbinol on diethylnitrosamine-induced preneoplastic glutathione S-transferase placental form-positive liver cell foci in Sprague-Dawley rats. Jpn J Cancer Res 1994; 85:578-83. [PMID: 8063610 PMCID: PMC5919519 DOI: 10.1111/j.1349-7006.1994.tb02399.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The biphasic modifying effects of indole-3-carbinol (I3C), a naturally occurring constituent of edible cruciferous vegetables, on the development of glutathione S-transferase placental form (GST-P)-positive liver cell foci were investigated by using a medium-term liver bioassay system and a newborn rat hepatocarcinogenesis system. In Experiment 1, a total of 65 male Sprague-Dawley (SD) rats were divided into 5 groups. Animals were given a single intraperitoneal (i.p.) injection of 200 mg/kg diethylnitrosamine (DEN) dissolved in saline for groups 1, 2, and 3 or a single i.p. injection of saline for groups 4 and 5. Group 1 was given the diet containing 0.25% I3C for 2 weeks prior to DEN initiation and then basal diet for 8 weeks. Group 2 was given basal diet for 4 weeks prior to and after DEN initiation and then the diet containing 0.25% I3C for 6 weeks. The rats of group 3 were placed on basal diet during the experiment. Animals of groups 4 and 5 were treated in the same manner as those of groups 1 and 2 except for injection with saline instead of DEN solution. All rats were subjected to two-thirds partial hepatectomy at week 3 and were killed at week 8 after DEN or saline injection. In Experiment 2, a total of 45 female SD rats were dosed with DEN (100 mg/kg, i.p.) or saline at 24 h after birth. After weaning at week 3, the rats were fed diet containing 0.25% I3C for 9 weeks and then were killed at week 12. In Experiment 1, preinitiation exposure to 0.25% I3C caused a significant decrease in numbers of GST-P-positive liver cell foci (P < 0.05), while postinitiation exposure to 0.25% I3C caused significant increases in both number (No./cm2) and area (mm2/cm2) of GST-P-positive liver cell foci (P < 0.05 or 0.01). In Experiment 2, the relative liver weight in the DEN + I3C group was significantly increased (P < 0.001). The numbers and areas of GST-P-positive liver cell foci in the DEN + I3C group were significantly increased as compared to the values of the DEN-alone group (P < 0.001). These results clearly demonstrated that I3C exerts a promoting effect on the postinitiation stage as well as an inhibitory effect on the preinitiation stage in the medium-term liver bioassay.
Collapse
Affiliation(s)
- D J Kim
- Department of Pathology, National Institute of Safety Research, Seoul, Korea
| | | | | | | | | | | |
Collapse
|
46
|
Tanaka M, Takaishi S, Ohdaira T, Kobayashi T, Maruyama R, Ahn B, Masuda A, Masuyama S, Honda Y. Dependence of biphasic heart rate response to sustained hypoxia on magnitude of ventilation in man. Jpn J Physiol 1992; 42:865-75. [PMID: 1297855 DOI: 10.2170/jjphysiol.42.865] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We studied the dynamic profile of respiratory and circulatory activities during sustained isocapnic hypoxia in healthy males. In response to end-tidal PO2 depression to about 55 Torr, minute ventilation first increased briskly and then depressed. Such biphasic response to hypoxia was also observed in the heart rate. A significantly positive correlation was found between the magnitudes of ventilatory and heart rate responses. No significant increases were found in arterial noradrenaline and potassium, but adrenaline significantly increased gradually with time. Furthermore, when VT and f were intentionally maintained constant so as to prevent the biphasic ventilatory change, the biphasic heart rate response previously seen in spontaneous hypoxic breathing disappeared. We suggest that the heart rate is mainly determined by the pulmonary vagal inflation reflex. Putative neurochemicals to elicit hypoxic ventilatory depression, and arterial catecholamine and potassium concentrations may not be directly related to the specific profile of the biphasic heart rate response during moderate hypoxia.
Collapse
Affiliation(s)
- M Tanaka
- Department of Physiology, School of Medicine, Chiba University, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Ohdaira T, Kobayashi T, Tanaka M, Chowdhury MF, Ahn B, Masuda A, Sakakibara Y, Honda Y. Effect of verapamil on ventilatory and circulatory responses to hypoxia and hypercapnia in normal subjects. Jpn J Physiol 1992; 42:765-77. [PMID: 1491501 DOI: 10.2170/jjphysiol.42.765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Recent investigations have shown that the calcium channel blocker verapamil attenuated the hypoxic ventilatory chemosensitivity of carotid body in animals. To determine whether this is also the case in humans, transient physiological chemodenervation by O2 breaths (withdrawal test) during sustained hypoxia (N = 7), and ventilatory and circulatory responses to progressive hypoxia and hypercapnia (N = 8) were examined after oral administration of verapamil. During sustained hypoxia after verpamil, there was a significant reduction of withdrawal response from 5th to 25th min value (p < 0.01), but not after placebo. On the other hand, no significant difference in ventilatory responses to progressive hypoxia and hypercapnia was observed after verapamil. Verapamil run reveals similar features with placebo run in circulatory parameters except blood pressure response, which tended to be suppressed by verapamil. We conclude that verapamil attenuates peripheral chemoreceptor activity with time during sustained mild hypoxia in normal adult humans and this may be explained by delayed depletion in intracellular Ca2+ for chemotransduction of the peripheral chemoreceptors.
Collapse
Affiliation(s)
- T Ohdaira
- Department of Physiology, School of Medicine, Chiba University, Japan
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Claassen LA, Ahn B, Koo HS, Grossman L. Construction of deletion mutants of the Escherichia coli UvrA protein and their purification from inclusion bodies. J Biol Chem 1991; 266:11380-7. [PMID: 1645734] [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: 12/28/2022] Open
Abstract
The functions of each of the three subunits of the damage-specific UvrABC endonuclease is currently being studied by systematically mutagenizing the corresponding genes to generate mutant proteins for characterization in vitro. In this communication, we describe the construction of C-terminal deletion mutants of the UvrA protein and a procedure to purify the mutant and wild-type UvrA proteins from inclusion bodies in cells overexpressing the recombinant proteins. The method yields highly purified proteins with between 10 and 50% of the specific activity of wild-type UvrA purified by conventional techniques from the soluble fraction. The wild-type UvrA protein purified by this method had the properties of significant and selective loss of activity in assays of incision of damaged DNA, while still retaining high levels of the other unique molecular phenotypic properties associated with intact UvrA. Furthermore, the demonstration of the absolute requirement for zinc during refolding for recovery of activity is the first evidence that the zinc previously shown to be associated with the UvrA protein is in fact a necessary component for its function.
Collapse
Affiliation(s)
- L A Claassen
- Department of Biochemistry, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Maryland 21205
| | | | | | | |
Collapse
|
49
|
Claassen L, Ahn B, Koo H, Grossman L. Construction of deletion mutants of the Escherichia coli UvrA protein and their purification from inclusion bodies. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)99174-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
50
|
Tanaka M, Takaishi S, Ohdaira T, Kobayashi T, Maruyama R, Ahn B, Masuda A, Masuyama S, Honda Y. Dynamic profile of cardiovascular activity in relation to augmented ventilation and humoral agents during hypercapnic hypoxia. Jpn J Physiol 1991; 41:617-27. [PMID: 1791662 DOI: 10.2170/jjphysiol.41.617] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A time course of cardiovascular activity in 8 healthy males in relation to augmented ventilatory activity and humoral factors was observed during step CO2 elevation with constant hypoxia. During the first step increase, by 3 Torr in end-tidal PCO2 (PETCO2), the heart rate (HR) initially tended to decrease, then slowly increased to slightly below that of the previous eucapnic level, whereas ventilation maintained a gradual rise throughout this period. On the other hand, during second step PETCO2 elevation, by a further 3 Torr, both HR and ventilation progressively increased. The plasma catecholamine (CA) concentration was also significantly elevated during this period, suggesting a concomitant enhancement in sympathetic activity. Blood pressure (Bp) was progressively augmented throughout the entire hypoxic challenge. We conclude that 1) the characteristic profile of HR change may be explained by the observation that initial HR depression by peripheral chemoreceptor stimulation is gradually overridden by delayed hyperventilation, CA elevation, and enhanced sympathetic activity; 2) Bp augmentation may be elicited by increased CA release and sympathetic activity; and 3) plasma K+ concentration does not change so as to affect cardiovascular and respiratory activity.
Collapse
Affiliation(s)
- M Tanaka
- Department of Physiology, School of Medicine, Chiba University, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|