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Jeong K, Shah LM, Lee YJ, Thapa B, Sapkota N, Bisson E, Carlson NG, Jeong EK, Rose JW. High-b diffusivity of MS lesions in cervical spinal cord using ultrahigh-b DWI (UHb-DWI). Neuroimage Clin 2021; 30:102610. [PMID: 33752076 PMCID: PMC7985401 DOI: 10.1016/j.nicl.2021.102610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 02/11/2021] [Accepted: 02/18/2021] [Indexed: 12/27/2022]
Abstract
PURPOSE The purpose of this study was to investigate UHb-rDWI signal in white matter tracts of the cervical spinal cord (CSC) and compare quantitative values between healthy control WM with both MS NAWM and MS WM lesions. METHODS UHb-rDWI experiments were performed on (a) 7 MS patients with recently active or chronic lesions in CSC and on (b) 7 healthy control of similar age range and gender distribution to MS subjects. All MRI data were acquired using clinical 3T MRI system. Axial high-b diffusion images were acquired using 2D single-shot DW stimulated EPI with reduced FOV and a CSC-dedicated 8 channel array coil. High-b diffusion coefficient DH was estimated by fitting the signal-b curve to a double or single-exponential function. RESULTS The high-b diffusivity DH values were measured as (0.767 ± 0.297) × 10-3 mm2/s in the posterior column lesions, averaged over 6 MS patients, and 0.587 × 10-3 mm2/s in the corticospinal tract for another patient. The averaged DH values of the 7 healthy volunteers from the posterior and lateral column were (0.0312 ± 0.0306) × 10-3 and (0.0505 ± 0.0205) × 10-3 mm2/s, respectively. UHb-rDWI signal-b curves of the MS patients revealed to noticeably behave differently to that of the healthy controls. The patient signal-b curves decayed with greater high-b decay constants to reach lower signal intensities relative to signal-b curves of the healthy controls. CONCLUSION UHb-DWI of the CSC reveals a marked difference in signal-b-curves and DH values in MS lesions compared to NAWM and healthy control WM. Based on physical principles, we interpret these altered observations of quantitative diffusion values to be indicative of demyelination. Further studies in animal models will be required to fully interpret UHb-DWI quantitative diffusion values during demyelination and remyelination.
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Affiliation(s)
- Kyle Jeong
- Utah Center for Advanced Imaging Research, University of Utah, Utah, USA
| | - Lubdha M Shah
- Department of Radiology and Imaging Sciences, University of Utah, Utah, USA
| | - You-Jung Lee
- Utah Center for Advanced Imaging Research, University of Utah, Utah, USA
| | - Bijaya Thapa
- Utah Center for Advanced Imaging Research, University of Utah, Utah, USA
| | - Nabraj Sapkota
- Utah Center for Advanced Imaging Research, University of Utah, Utah, USA
| | - Erica Bisson
- Department of Neurosurgery, University of Utah, Utah, USA
| | - Noel G Carlson
- Neuroimmunology and Neurovirology Division, Department of Neurology, University of Utah, Utah, USA; GRECC, VA Salt Lake City Health Care System, Utah, USA; Department of Neurobiology, University of Utah, Utah, USA
| | - E K Jeong
- Utah Center for Advanced Imaging Research, University of Utah, Utah, USA; Department of Radiology and Imaging Sciences, University of Utah, Utah, USA
| | - John W Rose
- Neuroimmunology and Neurovirology Division, Department of Neurology, University of Utah, Utah, USA; Neurology Service, VA Salt Lake City Health Care System, Utah, USA.
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Lee SY, Jeong EK, Ju MK, Jeon HM, Kim MY, Kim CH, Park HG, Han SI, Kang HS. Induction of metastasis, cancer stem cell phenotype, and oncogenic metabolism in cancer cells by ionizing radiation. Mol Cancer 2017; 16:10. [PMID: 28137309 PMCID: PMC5282724 DOI: 10.1186/s12943-016-0577-4] [Citation(s) in RCA: 334] [Impact Index Per Article: 47.7] [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: 11/04/2016] [Accepted: 12/25/2016] [Indexed: 12/12/2022] Open
Abstract
Radiation therapy is one of the major tools of cancer treatment, and is widely used for a variety of malignant tumours. Radiotherapy causes DNA damage directly by ionization or indirectly via the generation of reactive oxygen species (ROS), thereby destroying cancer cells. However, ionizing radiation (IR) paradoxically promotes metastasis and invasion of cancer cells by inducing the epithelial-mesenchymal transition (EMT). Metastasis is a major obstacle to successful cancer therapy, and is closely linked to the rates of morbidity and mortality of many cancers. ROS have been shown to play important roles in mediating the biological effects of IR. ROS have been implicated in IR-induced EMT, via activation of several EMT transcription factors—including Snail, HIF-1, ZEB1, and STAT3—that are activated by signalling pathways, including those of TGF-β, Wnt, Hedgehog, Notch, G-CSF, EGFR/PI3K/Akt, and MAPK. Cancer cells that undergo EMT have been shown to acquire stemness and undergo metabolic changes, although these points are debated. IR is known to induce cancer stem cell (CSC) properties, including dedifferentiation and self-renewal, and to promote oncogenic metabolism by activating these EMT-inducing pathways. Much accumulated evidence has shown that metabolic alterations in cancer cells are closely associated with the EMT and CSC phenotypes; specifically, the IR-induced oncogenic metabolism seems to be required for acquisition of the EMT and CSC phenotypes. IR can also elicit various changes in the tumour microenvironment (TME) that may affect invasion and metastasis. EMT, CSC, and oncogenic metabolism are involved in radioresistance; targeting them may improve the efficacy of radiotherapy, preventing tumour recurrence and metastasis. This study focuses on the molecular mechanisms of IR-induced EMT, CSCs, oncogenic metabolism, and alterations in the TME. We discuss how IR-induced EMT/CSC/oncogenic metabolism may promote resistance to radiotherapy; we also review efforts to develop therapeutic approaches to eliminate these IR-induced adverse effects.
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Affiliation(s)
- Su Yeon Lee
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan, 609-735, Korea
| | - Eui Kyong Jeong
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan, 609-735, Korea
| | - Min Kyung Ju
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan, 609-735, Korea
| | - Hyun Min Jeon
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan, 609-735, Korea
| | - Min Young Kim
- Research Center, Dongnam Institute of Radiological and Medical Science (DIRAMS), Pusan, 619-953, Korea
| | - Cho Hee Kim
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan, 609-735, Korea.,DNA Identification Center, National Forensic Service, Seoul, 158-707, Korea
| | - Hye Gyeong Park
- Nanobiotechnology Center, Pusan National University, Pusan, 609-735, Korea
| | - Song Iy Han
- The Division of Natural Medical Sciences, College of Health Science, Chosun University, Gwangju, 501-759, Korea
| | - Ho Sung Kang
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan, 609-735, Korea.
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Jeong EK, Jang HJ, Kim SS, Lee SY, Oh MY, Kim HJ, Eom DW, Ham JY, Han DJ. Protective Effect of Polydeoxyribonucleotide Against Renal Ischemia-Reperfusion Injury in Mice. Transplant Proc 2016; 48:1251-7. [PMID: 27320598 DOI: 10.1016/j.transproceed.2016.01.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 01/14/2016] [Indexed: 11/27/2022]
Abstract
BACKGROUND Polydeoxyribonucleotide (PDRN) is an A2A receptor agonist that induces vascular endothelial growth factor (VEGF) production during the pathological condition of low tissue perfusion. Ischemia-reperfusion injury (IRI) is a major problem after renal transplantation. In the present study, we investigated whether PDRN exhibits reno-protective effects against ischemia-reperfusion-induced acute kidney injury in mice. METHODS Renal ischemia-reperfusion injury was induced in male C57BL/6 mice by bilateral renal pedicle occlusion for 30 minutes, followed by reperfusion for 48 hours. PDRN (8 mg/kg body weight intraperitoneally) was administered 30 minutes before IRI. RESULTS Treatment with PDRN significantly decreased neutrophil gelatinase-associated lipocalin levels in the urine, blood urea nitrogen level, and serum creatinine levels as well as kidney tubular injury. Western blotting showed that PDRN significantly increased the levels of vascular endothelial growth factor and B-cell lymphoma protein and attenuated p38 mitogen-activated protein kinase, c-Jun N-terminal kinase, inducible nitric oxide synthase, and Bcl-2-associated X protein levels 48 hours after IRI. CONCLUSIONS Our findings suggest that PDRN is a potential therapeutic agent for acute ischemia-induced renal damage.
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Affiliation(s)
- E K Jeong
- Department of Anesthesia and Pain Medicine, Ulsan University College of Medicine, Gangneung Asan Hospital, Gangneung, South Korea
| | - H J Jang
- Department of Surgery, Ulsan University College of Medicine, Gangneung Asan Hospital, Gangneung, South Korea.
| | - S S Kim
- Department of Anesthesia and Pain Medicine, Ulsan University College of Medicine, Gangneung Asan Hospital, Gangneung, South Korea
| | - S Y Lee
- Department of Surgery, Ulsan University College of Medicine, Gangneung Asan Hospital, Gangneung, South Korea
| | - M Y Oh
- Department of Surgery, Ulsan University College of Medicine, Gangneung Asan Hospital, Gangneung, South Korea
| | - H J Kim
- Department of Surgery, Ulsan University College of Medicine, Gangneung Asan Hospital, Gangneung, South Korea
| | - D W Eom
- Department of Pathology, Ulsan University College of Medicine, Gangneung Asan Hospital, Gangneung, South Korea
| | - J Y Ham
- Natural Medicine Center, Korea Institute of Science and Technology (KIST), Gangneung, South Korea
| | - D J Han
- Asan Medical Center, Seoul, South Korea
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Lee SY, Jeon HM, Ju MK, Jeong EK, Kim CH, Park HG, Han SI, Kang HS. Dlx-2 and glutaminase upregulate epithelial-mesenchymal transition and glycolytic switch. Oncotarget 2016; 7:7925-39. [PMID: 26771232 PMCID: PMC4884964 DOI: 10.18632/oncotarget.6879] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Accepted: 01/02/2016] [Indexed: 12/18/2022] Open
Abstract
Most cancer cells depend on enhanced glucose and glutamine (Gln) metabolism for growth and survival. Oncogenic metabolism provides biosynthetic precursors for nucleotides, lipids, and amino acids; however, its specific roles in tumor progression are largely unknown. We previously showed that distal-less homeobox-2 (Dlx-2), a homeodomain transcription factor involved in embryonic and tumor development, induces glycolytic switch and epithelial-mesenchymal transition (EMT) by inducing Snail expression. Here we show that Dlx-2 also induces the expression of the crucial Gln metabolism enzyme glutaminase (GLS1), which converts Gln to glutamate. TGF-β and Wnt induced GLS1 expression in a Dlx-2-dependent manner. GLS1 shRNA (shGLS1) suppressed in vivo tumor metastasis and growth. Inhibition of Gln metabolism by shGLS1, Gln deprivation, and Gln metabolism inhibitors (DON, 968 and BPTES) prevented Dlx-2-, TGF-β-, Wnt-, and Snail-induced EMT and glycolytic switch. Finally, shDlx-2 and Gln metabolism inhibition decreased Snail mRNA levels through p53-dependent upregulation of Snail-targeting microRNAs. These results demonstrate that the Dlx-2/GLS1/Gln metabolism axis is an important regulator of TGF-β/Wnt-induced, Snail-dependent EMT, metastasis, and glycolytic switch.
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Affiliation(s)
- Su Yeon Lee
- Department of Molecular Biology, College of Natural Sciences, Pusan 609-735, Korea
| | - Hyun Min Jeon
- Department of Molecular Biology, College of Natural Sciences, Pusan 609-735, Korea
| | - Min Kyung Ju
- Department of Molecular Biology, College of Natural Sciences, Pusan 609-735, Korea
| | - Eui Kyong Jeong
- Department of Molecular Biology, College of Natural Sciences, Pusan 609-735, Korea
| | - Cho Hee Kim
- Department of Molecular Biology, College of Natural Sciences, Pusan 609-735, Korea
| | - Hye Gyeong Park
- Nanobiotechnology Center, Pusan National University, Pusan 609-735, Korea
| | - Song Iy Han
- The Division of Natural Medical Sciences, College of Health Science, Chosun University, Gwangju 501-759, Korea
| | - Ho Sung Kang
- Department of Molecular Biology, College of Natural Sciences, Pusan 609-735, Korea
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Lee SY, Jeon HM, Ju MK, Jeong EK, Kim CH, Yoo MA, Park HG, Han SI, Kang HS. Dlx-2 is implicated in TGF-β- and Wnt-induced epithelial-mesenchymal, glycolytic switch, and mitochondrial repression by Snail activation. Int J Oncol 2015; 46:1768-80. [PMID: 25651912 DOI: 10.3892/ijo.2015.2874] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 01/05/2015] [Indexed: 01/09/2023] Open
Abstract
Epithelial-mesenchymal transition (EMT) and oncogenic metabolism (including glycolytic switch) are important for tumor development and progression. Here, we show that Dlx-2, one of distal-less (Dlx) homeobox genes, induces EMT and glycolytic switch by activation of Snail. In addition, it was induced by TGF-β and Wnt and regulates TGF-β- and Wnt-induced EMT and glycolytic switch by activating Snail. We also found that TGF-β/Wnt suppressed cytochrome c oxidase (COX), the terminal enzyme of the mitochondrial respiratory chain, in a Dlx-2/Snail-dependent manner. TGF-β/Wnt appeared to downregulate the expression of various COX subunits including COXVIc, COXVIIa and COXVIIc; among these COX subunits, COXVIc was a common target of TGF-β, Wnt, Dlx-2 and Snail, indicating that COXVIc downregulation plays an important role(s) in TGF-β/Wnt-induced COX inhibition. Taken together, our results showed that Dlx-2 is involved in TGF-β- and Wnt-induced EMT, glycolytic switch, and mitochondrial repression by Snail activation.
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Affiliation(s)
- Su Yeon Lee
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan 609-735, Republic of Korea
| | - Hyun Min Jeon
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan 609-735, Republic of Korea
| | - Min Kyung Ju
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan 609-735, Republic of Korea
| | - Eui Kyong Jeong
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan 609-735, Republic of Korea
| | - Cho Hee Kim
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan 609-735, Republic of Korea
| | - Mi-Ae Yoo
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan 609-735, Republic of Korea
| | - Hye Gyeong Park
- Nanobiotechnology Center, Pusan National University, Pusan 609-735, Republic of Korea
| | - Song Iy Han
- The Division of Natural Medical Sciences, College of Health Science, Chosun University, Gwangju 501-759, Republic of Korea
| | - Ho Sung Kang
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan 609-735, Republic of Korea
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Jeong EK, Lee SY, Jeon HM, Ju MK, Kim CH, Kang HS. Role of extracellular signal-regulated kinase (ERK)1/2 in multicellular resistance to docetaxel in MCF-7 cells. Int J Oncol 2010; 37:655-61. [PMID: 20664934 DOI: 10.3892/ijo_00000714] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Cancer cells frequently fail to respond to chemotherapy due to acquisition of chemoresistance. Tumour cells are prone to die by necrosis when they are metabolically stressed by hypoxic and glucose depletion (OGD) due to insufficient vascularization, a common feature of solid tumours. Tumour necrosis indicates poor prognosis and emergence of drug resistance in cancer patients; however, its molecular mechanism remains unclear. In this study, we used multicellular tumour spheroids (MTS) as an in vitro tumour model to investigate the molecular mechanisms underlying necrosis-linked drug resistance. MCF-7 cells formed tight and spherical shape of spheroids and started to form the necrotic core at 8 days of culture. We found that docetaxel (DOC)-induced apoptosis was gradually reduced during MCF-7 spheroid culture compared to that in monolayers and that more prominent resistance to DOC was observed when spheroids containing the necrotic core were treated. ERK1/2 and Akt appeared to be activated in MCF-7 spheroids with necrotic core, but not in 2D culture cells and in spheroids without necrotic core. DOC resistance in spheroids was reversed by inhibition of ERK1/2, but not of Akt, suggesting an important role for ERK1/2 in the DOC resistance in MCF-7 spheroids. These results provide new insight into the possible relation between necrosis-linked ERK1/2 activation and acquisition of multicellular resistance.
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Affiliation(s)
- Eui Kyong Jeong
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan 609-735, Korea
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Kim CH, Jeon HM, Lee SY, Jeong EK, Ju MK, Park BJ, Park HG, Lim SC, Han SI, Kang HS. Role of reactive oxygen species-dependent protein aggregation in metabolic stress-induced necrosis. Int J Oncol 2010; 37:97-102. [PMID: 20514401 DOI: 10.3892/ijo_00000657] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Cancer cells in the inner region of avascularized solid tumours experience metabolical stress by hypoxic and glucose depletion (OGD) and are prone to die by necrosis to form a necrotic core, a common feature of solid tumours. Unlike in apoptosis, where the cellular contents remain packed in the apoptotic bodies that are removed by macrophages, necrosis is characterized by cell membrane rupture, and the release of many cellular proteins including tumour promoting cytokine high mobility group box 1 (HMGB1) into the extra-cellular space. Although ROS produced by metabolic stress are known to cause membrane damage leading to the plasma membrane rupture, its molecular mechanism remains unclear. In this study, we show that some cellular proteins including pro-apoptotic molecules p53, caspase-3, and caspase-9 and a pro-autophagic molecule beclin 1 are not released into the extracellular space but rather aggregated in the cytosol during GD-induced necrosis and that the protein aggregation occurs in a ROS-dependent manner. We also found that Snail, the transcription factor that is induced by GD, was not translocated to the nucleus and aggregated in the cytosol. In addition, Snail interference appeared to block metabolic stress-induced protein aggregation, indicating a critical role(s) of Snail in the protein aggregation. These results demonstrate that in metabolically stressed cancer cells, ROS induce a specific set of cellular proteins to form insoluble aggregates that are highly toxic to cells and trigger the necrosis-associated membrane rupture and HMGB1 release to promote tumour progression.
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Affiliation(s)
- Cho Hee Kim
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan 609-735, Korea
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Kim CH, Jeon HM, Lee SY, Jeong EK, Ju MK, Park BJ, Park HG, Lim SC, Han SI, Kang HS. Role of reactive oxygen species-dependent protein aggregation in metabolic stress-induced necrosis. Int J Oncol 2010. [PMID: 20514401 DOI: 10.3892/ijo-00000657] [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: 02/07/2023] Open
Abstract
Cancer cells in the inner region of avascularized solid tumours experience metabolical stress by hypoxic and glucose depletion (OGD) and are prone to die by necrosis to form a necrotic core, a common feature of solid tumours. Unlike in apoptosis, where the cellular contents remain packed in the apoptotic bodies that are removed by macrophages, necrosis is characterized by cell membrane rupture, and the release of many cellular proteins including tumour promoting cytokine high mobility group box 1 (HMGB1) into the extra-cellular space. Although ROS produced by metabolic stress are known to cause membrane damage leading to the plasma membrane rupture, its molecular mechanism remains unclear. In this study, we show that some cellular proteins including pro-apoptotic molecules p53, caspase-3, and caspase-9 and a pro-autophagic molecule beclin 1 are not released into the extracellular space but rather aggregated in the cytosol during GD-induced necrosis and that the protein aggregation occurs in a ROS-dependent manner. We also found that Snail, the transcription factor that is induced by GD, was not translocated to the nucleus and aggregated in the cytosol. In addition, Snail interference appeared to block metabolic stress-induced protein aggregation, indicating a critical role(s) of Snail in the protein aggregation. These results demonstrate that in metabolically stressed cancer cells, ROS induce a specific set of cellular proteins to form insoluble aggregates that are highly toxic to cells and trigger the necrosis-associated membrane rupture and HMGB1 release to promote tumour progression.
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Affiliation(s)
- Cho Hee Kim
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan 609-735, Korea
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Lee SY, Jeon HM, Kim CH, Jeong EK, Ju MK, Park SY, Jung SY, Kim YJ, Lim SC, Han SI, Kang HS. CuZnSOD and MnSOD inhibit metabolic stress-induced necrosis and multicellular tumour spheroid growth. Int J Oncol 2010. [PMID: 20514411 DOI: 10.3892/ijo-00000667] [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: 02/07/2023] Open
Abstract
CuZnSOD and MnSOD have been shown to exert tumour suppressive activities; however, their exact molecular mechanism is still unclear. We investigated the molecular mechanism underlying the tumour suppressive activities of CuZnSOD and MnSOD using multicellular tumour spheroid (MTS), an in vitro tumour model. Overexpression of CuZnSOD and MnSOD significantly suppressed the growth of A549 and MCF-7 MTS, supporting a critical role(s) of reactive oxygen species (ROS) in tumour growth. In solid tumours, ROS is produced by metabolic stress due to insufficient oxygen and glucose supply and induces necrosis that is known to promote tumour progression by releasing the proinflammatory cytokine HMGB1. We observed that CuZnSOD and MnSOD overexpression prevents metabolic stress-induced necrosis and HMGB1 release by inhibiting mitochondrial ROS and intracellular O2- production in response to glucose depletion in two dimensional cell culture. CuZnSOD and MnSOD overexpression also significantly repressed the occurrence of necrosis that was observed during MTS culture. In human tumour tissues including lung pulmonary adenocarcinoma, CuZnSOD and MnSOD expression was detected in the para-necrotic region that was identified by the expression of a hypoxic marker carbonic anhydrase (CA) IX. These results suggest that CuZnSOD and MnSOD may suppress tumour growth through inhibiting metabolic stress-induced necrosis and HMGB1 release via inhibiting metabolic stress-induced mitochondrial ROS production.
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Affiliation(s)
- Su Yeon Lee
- Department of Molecular Biology, College of Natural Sciences, Pusan National University, Pusan 609-735, Korea
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Kim TH, Zollinger L, Shi XF, Kim SE, Rose J, Patel AA, Jeong EK. Quantification of diffusivities of the human cervical spinal cord using a 2D single-shot interleaved multisection inner volume diffusion-weighted echo-planar imaging technique. AJNR Am J Neuroradiol 2010; 31:682-7. [PMID: 20019109 DOI: 10.3174/ajnr.a1881] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [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: 12/29/2022]
Abstract
BACKGROUND AND PURPOSE DTI is a highly sensitive technique, which can detect pathology not otherwise noted with conventional imaging methods. This paper provides the atlas of reliable normative in vivo DTI parameters in the cervical spinal cord and its potential applications toward quantifying pathology. MATERIALS AND METHODS In our study, we created a reference of normal diffusivities of the cervical spinal cord by using a 2D ss-IMIV-DWEPI technique from 14 healthy volunteers and compared parameters with those in 8 patients with CSM. The 2D ss-IMIV-DWEPI technique was applied in each subject to acquire diffusion-weighted images. FA, lambda( parallel), and lambda( perpendicular) were calculated. A reference of normal DTI indices from 12 regions of interest was created and compared with DTI indices of 8 patients. RESULTS A map of reference diffusivity values was obtained from healthy controls. We found statistically significant differences in diffusivities between healthy volunteers and patients with CSM with different severities of disease, by using FA, lambda( parallel), and lambda( perpendicular) values. CONCLUSIONS DTI using 2D ss-IMIV-DWPEI is sensitive to spinal cord pathology. This technique can be used to detect and quantify the degree of pathology within the cervical spinal cord from multiple disease states.
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Affiliation(s)
- T H Kim
- Department of Radiology, Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, 84108-1218, USA
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Guo JY, Kim SE, Parker DL, Jeong EK, Zhang L, Roemer RB. Improved accuracy and consistency in T1 measurement of flowing blood by using inversion recovery GE-EPI. Med Phys 2005; 32:1083-93. [PMID: 15895593 DOI: 10.1118/1.1879732] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [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: 01/27/2023] Open
Abstract
Problems associated with techniques currently used to measure the T1 of flowing blood are evaluated and a method to improve the consistency and repeatability of measurements is presented. Similar to some currently used techniques, the pulse sequence employs a nonselective adiabatic inversion pulse followed by a series of ECG-gated gradient echo EPI (echo planar imaging) images to obtain images where the blood (fluid) signal exhibits a T1-dependent inversion recovery signal from which the spin lattice relaxation constant (T1) of the flowing fluid can be measured. The new method combines curve fitting with a measure of the curve null point to acquire more accurate and consistent T1 values. Simulation and experimental results show that this combined fitting-nulling method is more stable and consistent in measuring the T1 of flowing fluid. The feasibility of temperature measurement of a flowing fluid based on the temperature dependence of the T1 of water protons is shown in this paper. ECG gating is used to reduce the effects of cyclic intensity changes for measurement of T1 in pulsatile flowing blood.
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Affiliation(s)
- Jun-Yu Guo
- Department of Physics and the Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, Utah 84108, USA.
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Abstract
Recent advances in treatments of the cartilage abnormalities require more information on the extent and shape of cartilage abnormalities and need for early detection of the lesions. In this article we review MR appearance of the cartilage correlated with histology, MR-related artifacts for cartilage imaging, conventional and dedicated MR techniques suitable for the cartilage, and their clinical utilization.
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Affiliation(s)
- J S Suh
- Department of Diagnostic Radiology, Research Institute of Radiological Science, Brain Korea 21 project for Medical Science, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu, 120-752 Seoul, Korea.
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Lee SK, Kim DI, Jeong EK, Yoon PH, Cha SH, Lee JH. Temporal changes in reversible cerebral ischemia on perfusion- and diffusion-weighted magnetic resonance imaging: the value of relative cerebral blood volume maps. Neuroradiology 2002; 44:103-8. [PMID: 11942359 DOI: 10.1007/s002340100705] [Citation(s) in RCA: 11] [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: 12/16/2022]
Abstract
Using a transorbital approach we induced the temporal occlusion and reperfusion model in 18 cats. A vascular clamp was placed on the main trunk of the left middle cerebral artery (MCA) for 1 h. Diffusion- and perfusion-weighted MR images were obtained at 1, 3, 6 and 24 h after the clip was released. The cats were killed 24 h after reperfusion, and triphenyl tetrazolium chloride (TTC) staining was performed. After the relative cerebral blood volume (rCBV), time to peak enhancement (TTP) and apparent diffusion coefficient (ADC) maps had been acquired, ROIs were drawn on (1) the area of the infarct produced, (2) the area of high signal intensity on initial diffusion-weighted magnetic resonance imaging (DWI) but normal on TTC staining, e.g., salvaged parenchyma. The ratios of these areas to the normal contralateral cortex were calculated and compared with those of the areas of the final infarct and the salvaged parenchyma. Areas of final infarct showed a temporal increase of rCBV on 3 and 6-h imaging and a final depletion on 24-h imaging. A persistent decrease of ADC value and delayed TTP were observed. Salvaged parenchyma also showed increased rCBV after reperfusion until the last imaging comparing it to the final area of infarct (P < 0.05, 24-h rCBV). The initial decrease in the ADC and delayed TTP normalized on 24-h imaging. In conclusion, rCBV of 24-h imaging was the reliable parameter to predict final infarct. A combination of serial changes on DWI and perfusion-weighted imaging (PWI) can predict ischemic penumbra and outcome.
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Affiliation(s)
- S K Lee
- Department of Diagnostic Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seodaemungu, Seoul, Korea
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Kim JA, Chung JI, Yoon PH, Kim DI, Chung TS, Kim EJ, Jeong EK. Transient MR signal changes in patients with generalized tonicoclonic seizure or status epilepticus: periictal diffusion-weighted imaging. AJNR Am J Neuroradiol 2001; 22:1149-60. [PMID: 11415912 PMCID: PMC7974775] [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: 02/20/2023]
Abstract
BACKGROUND AND PURPOSE Our purpose was to investigate transient MR signal changes on periictal MR images of patients with generalized tonicoclonic seizure or status epilepticus and to evaluate the clinical significance of these findings for differential diagnosis and understanding of the pathophysiology of seizure-induced brain changes. METHODS Eight patients with MR images that were obtained within 3 days after the onset of generalized tonicoclonic seizure or status epilepticus and that showed seizure-related MR signal changes had their records retrospectively reviewed. T1- and T2-weighted images were obtained of all eight patients. Additional diffusion-weighted images were obtained of five patients during initial examination. After adequate control of the seizure was achieved, follow-up MR imaging was performed. We evaluated the signal changes, location of the lesions, and degree of contrast enhancement on T1- and T2-weighted images and the signal change and apparent diffusion coefficient (ADC) on diffusion-weighted images. We also compared the signal changes of the initial MR images to those of the follow-up MR images. RESULTS The initial MR images revealed focally increased T2 signal intensity, swelling, and increased volume of the involved cortical gyrus in all eight patients. The lesions were located in the cortical gray matter or subcortical white matter in seven patients and at the right hippocampus in one. T1-weighted images showed decreased signal intensity at exactly the same location (n = 6) and gyral contrast enhancement (n = 4). Diffusion-weighted images revealed increased signal intensity at the same location and focally reduced ADC. The ADC values were reduced by 6% to 28% compared with either the normal structure opposite the lesion or normal control. Follow-up MR imaging revealed the complete resolution of the abnormal T2 signal change and swelling in five patients, whereas resolution of the swelling with residual increased T2 signal intensity at the ipsilateral hippocampus was observed in the other two patients. For one of the two patients, hippocampal sclerosis was diagnosed. For the remaining one patient, newly developed increased T2 signal intensity was shown. CONCLUSION The MR signal changes that occur after generalized tonicoclonic seizure or status epilepticus are transient increase of signal intensity and swelling at the cortical gray matter, subcortical white matter, or hippocampus on periictal T2-weighted and diffusion-weighted images. These findings reflect transient cytotoxic and vasogenic edema induced by seizure. The reversibility and typical location of lesions can help exclude the epileptogenic structural lesions.
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Affiliation(s)
- J A Kim
- Department of Diagnostic Radiology, the Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, South Korea
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Kim HS, Kim DI, Lee BI, Jeong EK, Choi C, Lee JD, Yoon PH, Kim EJ, Kim SH, Yoon YK. Diffusion-weighted image and MR spectroscopic analysis of a case of MELAS with repeated attacks. Yonsei Med J 2001; 42:128-33. [PMID: 11293491 DOI: 10.3349/ymj.2001.42.1.128] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
We report the clinical and MR manifestations of an 18 year-old girl with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome. Recurrent status epilepticus caused reversible cytotoxic edema on diffusion-weighted images (DWI). Initial and one month follow-up MR spectroscopy, after seizure control, showed some discrepancies in the ratio of metabolites. N-acetylaspartate (NAA) partially recovered (NAA/creatine (Cr) ratio: 1.27-->1.84). This was because of a normalization of decreased NAA due to cellular dysfunction as a result of status epilepticus. A low ratio of NAA/Cr due to abnormal mitochondria remained in the decreased state. Reversible NAA/Cr ratios in the acute lesion suggested that NAA reflects the neuronal function as well as the level of neuronal structural damage. The altered NAA/Cr ratio better correlated with the abnormal signal intensity area of T2-weighted images (T2WI) and DWI than the lactate (Lac)/Cr ratio. With conservative treatment with anti-epileptics not accompanied by coenzyme Q or sodium dichloroacetate, lactate persistently increased (Lac/Cr ratio: 1.01-->1.21) because of the continued production of lactate in cells with respiratory deficiency, which is the main pathology of MELAS.
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Affiliation(s)
- H S Kim
- Department of Diagnostic Radiology, Yonsei University College of Medicine, Seoul, Korea
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Huh YM, Suh JS, Jeong EK, Lee SK, Lee JS, Choi BW, Kim DK. Role of the inflamed synovial volume of the wrist in defining remission of rheumatoid arthritis with gadolinium-enhanced 3D-SPGR MR imaging. J Magn Reson Imaging 1999; 10:202-8. [PMID: 10441026 DOI: 10.1002/(sici)1522-2586(199908)10:2<202::aid-jmri15>3.0.co;2-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The purpose of this study was to assess the role of inflamed synovial volume (ISV) in defining a state of remission in rheumatoid arthritis (RA) with contrast-enhanced, fat-suppression, three-dimensional (3D) gradient-recalled acquisition in the steady state with radiofrequency spoiling (SPGR) magnetic resonance (MR) imaging. Sixteen patients with RA (5 remission and 11 non-remission patients) were enrolled in this study. Contrast-enhanced, fat-suppression, 3D-SPGR MR imaging was performed before (n = 12) and after (n = 16) a mean 17 months of disease-modifying antirheumatic drugs (DMARDs). ISV was calculated by using a segmentation method. Statistical analysis of changes in ISVs and residual ISVs between the remission and the non-remission groups was performed. Intra- and inter-observer reproducibility was tested. Residual ISVs and relative changes in ISVs were 3.23 +/- 1.84 cm(3) and 51.4% (range 47.6-55.2%) in the remission group and 6.26 +/- 2. 03 cm(3)and 31.4% (range -73.5-53.5%) in the non-remission group. Both values were significantly different between the two groups (P < 0.05 and 0.05, respectively). Volume measurement showed high reproducibility: Intra- and inter-observer mean percentage errors were 5.04, 7.06, and 5.09%, respectively. Residual ISVs and relative changes in ISVs measured by MR imaging may provide objective and quantitative parameters in defining a state of remission in RA after therapy; however, the clinical utility of these measurements remains to be verified. J. Magn. Reson. Imaging 1999;10:202-208.
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Affiliation(s)
- Y M Huh
- Department of Diagnostic Radiology, Yonsei University, College of Medicine, Seoul, 120-752 Korea
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Kim DJ, Suh JS, Jeong EK, Shin KH, Yang WI. Correlation of laminated MR appearance of articular cartilage with histology, ascertained by artificial landmarks on the cartilage. J Magn Reson Imaging 1999; 10:57-64. [PMID: 10398978 DOI: 10.1002/(sici)1522-2586(199907)10:1<57::aid-jmri8>3.0.co;2-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [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: 11/12/2022] Open
Abstract
The object of this study was to correlate the laminae of articular cartilage on magnetic resonance (MR) imaging with histologic layers. T1- and fast spin-echo T2-weighted images of articular cartilage with artificial landmarks were obtained under high gradient echo strength (25 mT/m) conditions and a voxel size of 78 x 156 x 2000 microm. Images were also obtained with a) changed frequency-encoding directions; b) changed readout gradient strength; and c) a varied number of phase-encoding steps. T2 mapping was performed with angular variations. Artificial landmarks allowed accurate comparison between the laminae on MR images and the histologic zones. No alterations of the laminae were noted by changing the frequency gradient direction. Altering readout gradient strengths did not show a difference in the thickness of the laminae, and increasing the phase-encoding steps resulted in a more distinct laminated appearance, ruling out chemical shift, susceptibility, and truncation artifacts. The T2 mapping profile showed an anisotropic angular dependency from the magic angle effect. In conclusion, the laminated appearance of articular cartilage on spin-echo and fast spin-echo MR images correlated with the histologic zones rather than MR artifacts.
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Affiliation(s)
- D J Kim
- Department of Diagnostic Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Korea
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Suh JS, Jeong EK, Shin KH, Cho JH, Na JB, Kim DH, Han CD. Minimizing artifacts caused by metallic implants at MR imaging: experimental and clinical studies. AJR Am J Roentgenol 1998; 171:1207-13. [PMID: 9798849 DOI: 10.2214/ajr.171.5.9798849] [Citation(s) in RCA: 146] [Impact Index Per Article: 5.6] [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
OBJECTIVE The purpose of this study was to investigate the effect of metallic implant positioning on MR imaging artifacts, to determine the optimal imaging conditions for minimizing artifacts, and to show the usefulness of artifact-minimizing methods in imaging of the knee. MATERIALS AND METHODS Using MR images of experimental phantoms (titanium alloy and stainless steel screws), we compared the magnitude of metal-induced artifacts for various pulse sequences, different imaging parameters for the fast spin-echo sequence, and different imaging parameters for several incremental angles between the long axis of the screw and the direction of the main magnetic field. In clinical MR imaging of knees with metallic implants (n = 19), we assessed geometric distortion of anatomic structures to compare the influence of different pulse sequences (n = 19), frequency-encoding directions (n = 7), and knee positions (n = 15). RESULTS Titanium alloy screws consistently produced smaller artifacts than did stainless steel screws. In experimental MR studies, artifacts were reduced with fast spin-echo sequences, with a screw orientation as closely parallel to the main magnetic field as possible, and, particularly, with smaller voxels that correlated positively with artifact size (R2 = .88, p < .01). In clinical MR studies, fast spin-echo MR imaging obscured articular structures less than did spin-echo imaging (8/19 patients). In particular, the anterior-posterior frequency-encoding direction (3/7 patients) and the flexion position of the knee (5/15 patients) were effective in reducing artifacts. CONCLUSION MR artifacts can be minimized by optimally positioning in the magnet subjects with metallic implants and by choosing fast spin-echo sequences with an anterior-posterior frequency-encoding direction and the smallest voxel size.
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Affiliation(s)
- J S Suh
- Department of Diagnostic Radiology, Yonsei University College of Medicine, Research Institute of Radiological Science, Seoul, Korea
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Yu JS, Kim KW, Kim YH, Jeong EK, Chien D. Comparison of multishot turbo spin echo and HASTE sequences for T2-weighted MRI of liver lesions. J Magn Reson Imaging 1998; 8:1079-84. [PMID: 9786145 DOI: 10.1002/jmri.1880080512] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The purpose of this study was to compare the relative usefulness of multishot turbo spin echo (TSE) and half-Fourier single-shot turbo spin echo (HASTE) for determination of optimal breath-hold fast T2-weighted technique in terms of lesion detection, lesion-to-liver contrast-to-noise ratio (CNR), and image quality. The images of TSE with and without fat suppression (FS) and of HASTE with and without FS were retrospectively reviewed for 49 patients with 128 lesions. Without FS, TSE and HASTE images allowed depiction of focal hepatic masses (112 of 128, sensitivity = 87.5%) at the same rate. TSE with FS depicted more focal lesions (115 of 128, 89.8%) than HASTE with FS (109 of 128, 85.2%), but the difference was not statistically significant (P > .05). The CNR of each lesion on HASTE sequences was greater (P < .01) than that on TSE sequences. The CNR of hemangioma was distinct from that of solid tumors and cystic lesions in all sequences, and the range of CNR in each group of pathologies overlapped less and were well separated in the HASTE sequences. HASTE sequences produced better image quality with fewer artifacts (P < .0001). The results of this study suggest that HASTE sequences allow differentiation between solid tumors, hemangiomas, and cystic lesions in terms of CNR, producing fewer image artifacts, with acceptable sensitivity in lesion detection.
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Affiliation(s)
- J S Yu
- Department of Diagnostic Radiology, Yonsei University College of Medicine, Seoul, South Korea.
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Abstract
Most of medical images, especially tomographic images, are in digital. It is worth getting these digital data onto the personal computer and doing extra post-processing without much difficulties. The extra processing of obtained medical images may not give the great benefits for clinical purpose, however it is recommended to analyze obtained images more quantitatively for publication or presentation of one's results. Simple post-processing of MR and SPECT images was achieved using a public domain image processing software (NIH Image 1.56) on a Macintosh computer. The general concepts of the file transfer, the reading of the images into the software, and some examples of the processing are to be discussed.
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Affiliation(s)
- E K Jeong
- Department of Diagnostic Radiology, Yonsei University College of Medicine, Seoul, Korea
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Jeong EK, Ouyang B, Norberg RE, Fedders PA, Conradi MS. HD and D2 layers physisorbed on MgO studied by NMR. Phys Rev Lett 1992; 69:2983-2986. [PMID: 10046691 DOI: 10.1103/physrevlett.69.2983] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Jeong EK, Holzer JC, Carlsson AE, Conradi MS, Fedders PA, Kelton KF. Highly symmetric Mn sites in icosahedral Ti-Mn. Phys Rev B Condens Matter 1990; 41:1695-1698. [PMID: 9993892 DOI: 10.1103/physrevb.41.1695] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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