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Choi EJ, Kim GH. Hepatoprotective effects of daidzein against 7,12-dimetylbenz[a]anthracene-induced oxidative stress in mice. Int J Mol Med 2009; 23:659-64. [PMID: 19360325 DOI: 10.3892/ijmm_00000177] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We investigated the effects of daidzein on the antioxidant defence system in mice with 7,12-dimethylbenz[a]-anthracene (DMBA)-induced oxidative stress. Daidzein was administered orally at 5 and 25 mg/kg body weight for 5 weeks. Subsequently, mice pretreated with daidzein received DMBA intragastrically twice a week for 2 weeks. As controls, mice were given vehicle or DMBA alone. In the DMBA group, biomarkers of oxidative stress (thiobarbituric acid reactive substances value, carbonyl content) were significantly increased. However, the rise in oxidative damage was significantly reduced by daidzein at the higher dose. In addition, several antioxidant enzymes were downregulated in the DMBA-treated mice. Catalase and superoxide dismutase activity was increased by daidzein in a dose-dependent manner. Although the reduced/oxidized glutathione ratio was unaffected, glutathione peroxidase and reductase were activated by daidzein, and the effect was significant at the higher dose. Further, in the DMBA-treated mice, apoptosis was induced by a decrease in Bcl-2 and an increase in Bax. These changes were restored to their normal values in the daidzein-treated mice. Upregulation of caspase-3 was also decreased by daidzein. These results suggest that daidzein exerts a hepatoprotective effect on mice with DMBA-induced oxidative stress through its antioxidant activity and the reduction of apoptosis.
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Choi EJ, Kim GH. Apigenin Induces Apoptosis through a Mitochondria/Caspase-Pathway in Human Breast Cancer MDA-MB-453 Cells. J Clin Biochem Nutr 2009; 44:260-5. [PMID: 19430615 PMCID: PMC2675027 DOI: 10.3164/jcbn.08-230] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Accepted: 11/28/2008] [Indexed: 11/24/2022] Open
Abstract
In this study, we investigated the mechanistic role of the caspase cascade in extrinsic and intrinsic apoptosis induced by apigenin, which has been targeted as a candidate in the development of noncytotoxic anticancer medicines. Treatment with apigenin (1–100 µM) significantly inhibited the proliferation of MDA-MB-453 human breast cancer cells in a dose- and time-dependent manner with IC50 values of 59.44 and 35.15 µM at 24 and 72 h, respectively. This inhibition resulted in the induction of apoptosis and the release of cytochrome c in cells exposed to apigenin at its 72 h IC50. Subsequently, caspase-9, which acts in mitochondria-mediated apoptosis, was cleaved by apigenin. In addition, apigenin activated caspase-3, which functions downstream of caspase-9. The apigenin-induced activation of caspase-3 was accompanied by the cleavage of capases-6, -7, and -8. These results are supported by evidence showing that the activity patterns of caspases-3, -8, and -9 were similar. The present study supports the hypothesis that apigenin-induced apoptosis involves the activation of both the intrinsic and extrinsic apoptotic pathways.
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Choi EJ, Sunwoo S. Correlations of clinical assessment tools with written examinations. KOREAN JOURNAL OF MEDICAL EDUCATION 2009; 21:43-52. [PMID: 25812956 DOI: 10.3946/kjme.2009.21.1.43] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Accepted: 02/07/2009] [Indexed: 06/04/2023]
Abstract
PURPOSE Despite the goal of medical education, which is 'training to be a primary care physician,' only written examinations (WEs) generally have been used to assess medical student ability. We assessed clinical competence using the CPX (clinical performance examination), PA (portfolio assessment), VMA (video-monitoring assessment), CGD (case group discussion), and PCP (primary clinical practice) during students' clerkships in family medicine and correlated these clinical assessment tools with WEs. Also, we correlated these tools with each other to determine the feasibility of each as a replacement of the other tools. METHODS Thirty-nine fourth year students at University of Ulsan College of Medicine took part in their clerkship in family medicine for 2 weeks during the first session of 2005. They took 1 CPX, 2 VMAs, 6 CGDs, and 2 PCPs and were required to submit their portfolios at the end of the clerkship. We evaluated the correlations of these tools and WEs by the overall scores of each class year and in each subject. RESULTS The CPX, VMA, and PCP showed no significant correlation,while PA showed strong correlation with 4th year students' overall WEs. The CGD showed strong correlation with all overall scores and with almost all subjects. In addition, the PA correlated significantly with CGD. CONCLUSION New clinical assessment tools, such as CPX, PA, and VMA, have no significant correlation with WE, even though these tools closely correspond with real clinical practice. Therefore, these tools should be considered as complementary instruments to better assess clinical competence.
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Choi EJ, Ahn WS. Antiproliferative effects of dehydrocostuslactone through cell cycle arrest and apoptosis in human ovarian cancer SK-OV-3 cells. Int J Mol Med 2009; 23:211-216. [PMID: 19148545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
The present study was conducted to investigate the effects of dehydrocostuslactone on the cell cycle distribution and apoptosis of human ovarian cancer SK-OV-3 cells and explored the mechanisms underlying these effects. Dehydrocostuslactone significantly inhibited cell proliferation in a dose-dependent manner and produced significant cell cycle arrest at the G2/M interface when applied at its IC50 (10.7 microM) for this system. Under the same conditions, dehydrocostuslactone caused a slight decrease in the expression of the cell cycle regulatory proteins CDK4 and cyclin E, as well as a small increase in the expression of the cyclin-dependent kinase inhibitor p21Cip1. In addition, the dehydrocostuslactone-induced accumulation of cells at the G2/M phase transition interface resulted in a significant decrease in CDK1 together with cyclin A and cyclin B. This cell cycle arrest induced apoptosis, as confirmed by annexin V and DAPI staining. Following exposure to dehydrocostuslactone, there was a marked increase in the expression of the apoptotic protein Bax and the downstream target p53, a tumor suppressor transcription factor protein, causing the release of cytochrome c. Based on our findings, the mechanism by which dehydrocostuslactone causes cell cycle arrest is via CDK1 down-regulation, and its induction of apoptosis appears to be related to the activation of p53 and the release of cytochrome c.
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Cho JH, Ko SG, Ahn YK, Song KC, Choi EJ. Preparation of biopolymer-coated magnetite nanoparticles for magnetic resonance image contrast agent. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2009; 9:779-782. [PMID: 19441391 DOI: 10.1166/jnn.2009.c023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The magnetite nanoparticles were synthesized using the sonochemical method with oleic acid as surfactant. The average size of the magnetite particles can be controlled by the ratio R = [H2O]/[surfactant] in the range of 2 to 9 nm. The size of the magnetite nanoparticles prepared by this method shows the narrow distribution. To prepare biopolymer(beta-glucan)-coated magnetite nanoparticles, beta-glucan solution was added to the magnetic colloid suspensions under the ultrasonication at room temperature. The beta-glucan coated magnetite colloidal suspensions of various concentrations did not agglomerate for 15 days, indicating their good stability. The beta-glucan-coated magnetite colloidal suspensions exhibited the enhancement of MRI contrasts in vitro.
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Choi JI, Pak HN, Park JH, Choi EJ, Kim SK, Kwak JJ, Jang JK, Hwang C, Kim YH. Clinical significance of complete conduction block of the left lateral isthmus and its relationship with anatomical variation of the vein of Marshall in patients with nonparoxysmal atrial fibrillation. J Cardiovasc Electrophysiol 2009; 20:616-22. [PMID: 19207770 DOI: 10.1111/j.1540-8167.2008.01408.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND The vein of Marshall (VOM), which exists along the left lateral isthmus (LLI), constitutes a muscular connection between the coronary sinus (CS) and the left atrium (LA). We hypothesized that anatomical variation of the VOM affects the bidirectional block of LLI and the clinical outcome in patients with nonparoxysmal atrial fibrillation (NPAF). METHODS Among 73 patients with NPAF, 54 patients (47 male, 54.1 +/- 10.4 years old) with a clearly visible VOM (74.0%) were included. After circumferential antral ablation, double linear endocardial ablation of LLI was performed along the VOM. Unless LLI block was achievable by endocardial ablation, the ablation was performed inside the CS. RESULTS LLI block was achievable in 35 patients (64.8%; 11.1% by endocardial ablation vs 53.7% by additional inside CS ablation; P < 0.01). In patients with failed LLI block, the VOM was significantly longer (P < 0.05) on the right anterior oblique (RAO) view than in those with successful LLI block. LA volume or LLI length measured by CT image were not different (P = NS). During 11.4 +/- 5.0 months follow-up, early recurrences within 3 months (47.4% vs 28.6%, P = NS) and recurrences after 3 months (10.5% vs 17.7%, P = NS) were not different with or without LLI block. CONCLUSION LLI block, which is more difficult to achieve in patients with a longer VOM, was achievable in 65% of patients with NPAF by linear ablation along the VOM and additional inside CS ablation, but did not affect the short-term clinical outcome.
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Kim YJ, Huh YM, Choe KO, Choi BW, Choi EJ, Jang Y, Lee JM, Suh JS. In vivo magnetic resonance imaging of injected mesenchymal stem cells in rat myocardial infarction; simultaneous cell tracking and left ventricular function measurement. Int J Cardiovasc Imaging 2009; 25 Suppl 1:99-109. [PMID: 19132547 DOI: 10.1007/s10554-008-9407-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Accepted: 12/17/2008] [Indexed: 02/06/2023]
Abstract
To determine whether magnetic resonance imaging (MRI) can enable magnetically labeled mesenchymal stem cell (MSC) tracking and simultaneous in vivo functional data acquisition in rat models of myocardial infarction. Superparamagnetic iron oxide-laden human MSCs were injected into rat myocardium infarcted by cryoinjury 3 weeks after myocardial infarction. The control group received cell-free media injection. Before injection and for 3 months after, in vivo serial MRI was performed. Electrocardiography-gated gradient echo sequence MRI and cine MRI were performed for in vivo cell tracking and assessing cardiac function using left ventricular ejection fraction (LVEF), respectively. MRI revealed a persistent signal-void representing iron-laden MSCs until ten post-injection weeks. Serial follow-up MRI revealed that LVEF was significantly higher in the MSC injection group than in the control group. We conclude that MRI enables in vivo tracking of injected cells and evaluation of the long-term therapeutic potential of MSCs for myocardial infarction.
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Choi EJ, Ahn WS. Kaempferol induced the apoptosis via cell cycle arrest in human breast cancer MDA-MB-453 cells. Nutr Res Pract 2008; 2:322-5. [PMID: 20016737 PMCID: PMC2788196 DOI: 10.4162/nrp.2008.2.4.322] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2008] [Revised: 11/05/2008] [Accepted: 11/23/2008] [Indexed: 11/21/2022] Open
Abstract
The aim of present study was to investigate the effects of kaempferol on cellular proliferation and cell cycle arrest and explore the mechanism for these effects in human breast carcinoma MDA-MB-453 cells. Cells were treated with kaempferol at various concentrations (ranging from 1 to 200 µM) for 24 and 48 hrs. Kaempferol significantly inhibited cancer cell growth in cells exposed to 50 and 10 µM of kaempferol and incubated for 24 and 48 hrs, respectively. Exposure to kaempferol resulted in cell cycle arrest at the G2/M phase. Of the G2/M-phase related proteins, kaempferol down-regulated CDK1 and cyclin A and B in cells exposed to kaempferol. In addition, small DNA fragments at the sub-G0 phase were increased by up to 23.12 and 31.90% at 10 and 50 µM incubated for 24 and 48 hrs, respectively. The kaempferol-induced apoptosis was associated with the up-regulation of p53. In addition, the phosphorylation of p53 at the Ser-15 residue was observed with kaempferol. Kaempferol inhibits cell proliferation by disrupting the cell cycle, which is strongly associated with the induction of arrest at G2/M phase and may induce apoptosis via p53 phosphorylation in human breast carcinoma MDA-MB-453 cells.
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Choi EJ, Bae SM, Ahn WS. Antiproliferative effects of quercetin through cell cycle arrest and apoptosis in human breast cancer MDA-MB-453 cells. Arch Pharm Res 2008; 31:1281-5. [PMID: 18958418 DOI: 10.1007/s12272-001-2107-0] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 08/18/2008] [Accepted: 09/23/2008] [Indexed: 10/21/2022]
Abstract
To explore the anticancer effects of the flavonoid quercetin on human breast cancer MDA-MB-453 cells via cell cycle regulation and the induction of apoptosis, the antiproliferative effect of quercetin was first examined by MTT assay. When MDA-MB-453 cells were treated with quercetin for various periods of time (3-24 hrs) and at various doses (1-100 microM), cell growth decreased significantly in a time-and dose-dependent manner. To elucidate the mechanism underlying the antiproliferative effect of quercetin, cell cycle progression and the induction of apoptosis in MDA-MB-453 cells exposed to 100 microM quercetin for 24 hrs were investigated. Quercetin caused a remarkable increase in the number of sub-G1 phase cells, and an Annexin-V assay revealed that exposure to quercetin affected apoptosis. Moreover, treatment with quercetin increased Bax expression but decreased Bcl-2 expression. Cleaved caspase-3 and PARP expression was also increased by quercetin. Thus, quercetin has probable anticancer activity. Our results suggest the existence of multiple pathways for the induction of cell cycle arrest and apoptosis by quercetin.
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Choi EJ, Ahn WS, Bae SM. Equol induces apoptosis through cytochrome c-mediated caspases cascade in human breast cancer MDA-MB-453 cells. Chem Biol Interact 2008; 177:7-11. [PMID: 18973749 DOI: 10.1016/j.cbi.2008.09.031] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2008] [Revised: 09/23/2008] [Accepted: 09/25/2008] [Indexed: 12/01/2022]
Abstract
This study investigated the role of the caspase activation cascade in extrinsic and intrinsic apoptosis induced by equol in human breast cancer MDA-MB cells. First, the antiproliferative effect of equol was determined in cells treated with 1-100 microM equol for 24, 48, and 72h. Equol significantly inhibited cell proliferation in a dose-dependent manner (p<0.05). Exposure to 50 or 100 microM equol for 72h strongly promoted apoptosis. Under the same conditions, remarkable cytochrome c release was observed. Subsequently, caspase-9, which acts in mitochondria-mediated apoptosis, was cleaved by equol at high concentrations, but caspase-8 activation of receptor-mediated apoptosis was not observed. At both equol concentrations, the caspase-8 and -9 activity assays showed similar patterns. In addition, equol treatment activated caspase-3, which is downstream from caspase-9, and this was accompanied by the cleavage of capase-6 and -7. Activation of these caspases leads to increased activation of PARP, lamin, and ICAD. This study suggests that equol induces the intrinsic pathway of apoptosis via caspase-9 and cytochrome c, independent of caspase-8, in human breast cancer MDA-MB-453 cells.
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Choi EJ, Kim GH. Daidzein causes cell cycle arrest at the G1 and G2/M phases in human breast cancer MCF-7 and MDA-MB-453 cells. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2008; 15:683-690. [PMID: 18541420 DOI: 10.1016/j.phymed.2008.04.006] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Revised: 03/05/2008] [Accepted: 04/14/2008] [Indexed: 05/26/2023]
Abstract
We examined the mechanisms by which daidzein inhibits the growth of breast cancer cells. First, we investigated its antiproliferative effects in MCF-7 and MDA-MB-453 cells exposed to 1-100 microM daidzein for 24, 48, or 72 h. Daidzein significantly inhibited cell proliferation in a dose- and time-dependent manner (p<0.05) and resulted in significant cell cycle arrest in the G1 and G2/M phases after 72 h of treatment at concentrations over 5 and 10 microM in MCF-7 and MDA-MB-453 cells, respectively (p<0.05). In addition, daidzein caused the accumulation of cells in sub-G0 phase in a dose-dependent manner in MDA-MB-453 (p<0.05), but not MCF-7, cells. As another biomarker of apoptosis induction, caspase-9 activity was significantly increased by daidzein in both cells. To investigate the effects of daidzein on the proteins regulating cell cycle arrest, cells were treated with 100 microM daidzein for 72 h. Similar changes in the expression of regulatory proteins were detected in both cells. Daidzein treatment resulted in decreases in cyclin D, CDK2, and CDK4, whereas the expression of CDK6 and cyclin E was unchanged. The protein expression of CDK1 related to the G2/M phase decreased markedly with daidzein treatment, whereas slight expression of cyclins A and B occurred. Daidzein treatment increased the expression of the CDK inhibitors p21(Cip1) and p57(Kip2), but not that of p27(Kip1). Thus, daidzein exerts its anticancer effects in human breast cancer cells via cell cycle arrest at the G1 and G2/M phases.
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Choi EJ, Kim GH. Apigenin causes G(2)/M arrest associated with the modulation of p21(Cip1) and Cdc2 and activates p53-dependent apoptosis pathway in human breast cancer SK-BR-3 cells. J Nutr Biochem 2008; 20:285-90. [PMID: 18656338 DOI: 10.1016/j.jnutbio.2008.03.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Revised: 03/05/2008] [Accepted: 03/06/2008] [Indexed: 01/22/2023]
Abstract
We studied the effects of apigenin on the cell cycle distribution and apoptosis of human breast cancer cells and explored the mechanisms underlying these effects. We first investigated the antiproliferative effects in SK-BR-3 cells exposed to between 1 and 100 microM apigenin for 24, 48 and 72 h. Apigenin significantly inhibited cell proliferation at concentrations over 50 microM, regardless of exposure time (P<.05), and resulted in significant cell cycle arrest in the G(2)/M phase after 48 h of treatment at high concentrations (50 and 100 microM; P<.05). To investigate the regulatory proteins of cell cycle arrest affected by apigenin, we treated cells with 50 and 100 microM apigenin for 72 h. Apigenin caused a slight decrease in cyclin D and cyclin E expression, with no change in CDK2 and CDK4. In addition, the apigenin-induced accumulation of the cell population in the G(2)/M phase resulted in a decrease in CDK1 together with cyclin A and cyclin B. In an additional study, apigenin also increased the accumulation of p53 and further enhanced the level of p21(Cip1), with no change in p27(Kip1). The expression of Bax and cytochrome c of p53 downstream target was increased markedly at high concentration treatment over 50 microM apigenin. Based on our findings, the mechanism by which apigenin causes cell cycle arrest via the regulation of CDK1 and p21(Cip1) and induction of apoptosis seems to be involved in the p53-dependent pathway.
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Choi EJ, Kim G, Kim T. Equol induced the apoptosis via cell cycle arrest in MDA‐MB‐453 but not in MCF‐7 cells. FASEB J 2008. [DOI: 10.1096/fasebj.22.2_supplement.265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Choi EJ, Kim T. Equol induced apoptosis via cell cycle arrest in human breast cancer MDA-MB-453 but not MCF-7 cells. Mol Med Rep 2008; 1:239-244. [PMID: 21479403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023] Open
Abstract
To investigate the effects of equol on cell cycle distribution and apoptosis in human breast cancer cells, we first determined the antiproliferative effects of various concentrations of equol (1 nM to 100 µM) on MCF-7 and MDA-MB-453 cells at 24, 48 or 72 h of exposure. Equol significantly inhibited proliferation in MDA-MB-453 cells in a dose- and time-dependent manner. In contrast, equol at low concentrations (<1 µM) stimulated proliferation in MCF-7 cells, with increased expression of proliferating cell nuclear antigen (PCNA), and only inhibited proliferation at a high concentration (100 µM). Similarly, equol treatment of MDA-MB-453 cells resulted in significant cell cycle arrest at the G1/S transition and in the G2/M phase, whereas it caused the slight cell cycle arrest of MCF-7 cells in the G2/M phase after 72 h of treatment. Also, when cells were treated with 50 and 100 µM equol for 72 h, the equol affected cell cycle regulatory proteins more significantly in MDA-MB-453 than in MCF-7 cells. During equol-induced apoptosis, equol increased the number of cells in the sub-G0 phase and enhanced the level of p53. The expression of Bax and cytochrome c, downstream targets of p53, was markedly increased by treatment with higher concentrations of equol. Equol-induced cell cycle arrest and apoptosis apparently involves a p53-dependent pathway in different types of breast cancer cells.
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Choi EJ, Oh YW, Ham SY, Lee KY, Kang EY. Comparison between coronal reformatted images and direct coronal CT images of the swine lung specimen: assessment of image quality with 64-detector row CT. Br J Radiol 2008; 81:463-7. [PMID: 18283071 DOI: 10.1259/bjr/63217190] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The aims of this study were to compare the image quality of coronal multiplanar reconstruction (MPR) images from axial spiral images with that of direct coronal spiral and sequential images, and to estimate and analyse the effect of an incremental change on the image quality using 64-detector row CT. 12 swine lungs were used. Five kinds of images from each lung specimen were obtained using 64-detector row CT. All images were analysed by categories and grades, and the direct coronal sequential images were used as the reference standard for the image quality. Statistical analysis was performed for the following categories: (i) inter-observer reliability, (ii) interaction between the observers and images, (iii) image analysis, (iv) anatomical structural analysis of each observer, (v) stair-step artefact and (vi) background noise. The overall image quality and the image quality of all anatomical structures of coronal MPR images with 0.67 mm slice increments were inferior to the image quality of the other images; this difference was statistically significant (p<0.05). Stair-step artefact was detected on coronal MPR images, and was more prominent on coronal MPR images with 0.67 mm slice increments than on coronal MPR images with 0.34 mm slice increments. The most severe background noise was detected on the direct coronal sequential images, but there was no significant difference between the direct coronal sequential images and the direct coronal spiral images. Background noise was least prominent on coronal MPR images with 0.67 mm slice increments. The increment process is important for improving the image quality of MPR images even when using 64-detector row CT. Coronal MPR images with 0.34 mm slice increments using 64-detector row CT showed a similar image quality to that obtained from the direct coronal images, and can be used instead. This means that the coronal MPR images obtained with 64-detector row CT could be as useful for evaluating the lung parenchyma as the axial high-resolution CT images.
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Kim HS, Choi EJ, Park H. The effect of mosapride citrate on proximal and distal colonic motor function in the guinea-pig in vitro. Neurogastroenterol Motil 2008; 20:169-76. [PMID: 17931343 DOI: 10.1111/j.1365-2982.2007.00996.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Mosapride citrate (mosapride), a substituted benzamide, is a selective 5-HT(4) receptor agonist, and is known to have prokinetic properties on the stomach. However, it is unclear whether mosapride also has a prokinetic effect on the colon. We previously found that mosapride significantly shortened colonic transit time in the guinea-pig, an animal with a distribution of colonic 5-HT(4) receptors similar to that of a human. So, we aimed to separately evaluate the effect of mosapride on proximal and distal colonic motor function in the guinea-pig. Proximal (approximately 8 cm from the ileocolic junction) and distal colon (approximately 8 cm from the anus) were removed. Both ends of the colon were connected to a chamber containing a Krebs-Henseleit solution. To measure colonic transit time, artificial faeces were inserted into the oral side of the lumen and moved towards the anal side by intraluminal perfusion via a peristaltic pump. A total of 6 cm of transit was observed and time was measured in 2 cm increments. A tissue bath study, using electrical stimulation, was performed to estimate the contractile activity of the circular musculature of the colon. Immunohistochemical staining for 5-HT(4) receptors was performed in the myenteric plexus and circular muscle in both proximal and distal colon, and the stained area was measured using a microscope and computer software. Mosapride enhanced contraction at 10(-9) to 10(-7) mol L(-1), coinciding with rapid transit both in proximal and distal colon. This pattern was more prominent in proximal colon. At the high dose (10(-6) mol L(-1)) mosapride had little or no effect on colonic contraction. This stimulatory effect was attenuated by GR113808, atropine and tetrodotoxin. In the myenteric plexus, the density of 5-HT(4) receptors was significantly greater in the proximal colon than in the distal colon, but in circular muscle the density was greater in the distal colon. Thus, mosapride accelerates transit through increased contraction in the proximal colon more than distal colon. The different distribution of neuronal and muscular 5-HT(4) receptors may support these findings. Therefore, mosapride may be a useful alternative to tegaserod and cisapride for constipation.
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Yun HJ, Choi EJ, Choi EJ, Hong SY. A comparative study on iron deficiency anemia based on feeding patterns of nine-month-old infants. KOREAN JOURNAL OF PEDIATRICS 2008. [DOI: 10.3345/kjp.2008.51.8.820] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Choi EJ. Hesperetin Induced G1-Phase Cell Cycle Arrest in Human Breast Cancer MCF-7 Cells: Involvement of CDK4 and p21. Nutr Cancer 2007; 59:115-9. [DOI: 10.1080/01635580701419030] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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94
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Choi EJ, Kim T, Lee MS. Pro-apoptotic effect and cytotoxicity of genistein and genistin in human ovarian cancer SK-OV-3 cells. Life Sci 2007; 80:1403-8. [PMID: 17291540 DOI: 10.1016/j.lfs.2006.12.031] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Revised: 11/28/2006] [Accepted: 12/26/2006] [Indexed: 11/25/2022]
Abstract
We investigated the effects of genistein and genistin on proliferation and apoptosis of human ovarian SK-OV-3 cells and explored the mechanism for these effects. SK-OV-3 cells were treated with genistein and genistin at various concentrations (ranging from 1 to 100 muM) either alone or in combination for 24 and 48 h. Cell proliferation was estimated using an MTT assay, and cell cycle arrest was evaluated using FACS. Caspase-3 activity and annexin-based cell cycle analysis were used as measures of apoptosis. In addition, genistein- and genistin-induced cytotoxicity was determined by measuring release of LDH. Genistein treatment for 24 or 48 h substantially inhibited SK-OV-3 cell proliferation in a dose-dependent manner, and genistin treatment for 48 h also inhibited cell proliferation. Genistein caused cell cycle arrest at G2/M phase in dose- and time-dependent manner, and genistin caused cell cycle arrest not only at G2/M phase but also at G1 phase. Genistein markedly induced apoptosis and significantly increased LDH release, whereas genistin did not affect LDH release. Moreover, exposure to both genistein and genistin in combination for 48 h induced apoptosis without increasing LDH release. Genistein and genistin inhibit cell proliferation by disrupting the cell cycle, which is strongly associated with the arrest induction of either G1 or G2/M phase and may induce apoptosis. Based on our findings, we speculate that both genistein and genistin may prove useful as anticancer drugs and that the combination of genistein and genistin may have further anticancer activity.
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Choi EJ, Lee JI, Kim G. Evidence for Anti‐carcinogenic effect of Synthetic flavanone derivatives in human breast cancer cells. FASEB J 2007. [DOI: 10.1096/fasebj.21.6.a1346-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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96
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Choi EJ, Kim GD, Chee KM, Kim GH. Effects of hesperetin on vessel structure formation in mouse embryonic stem (mES) cells. Nutrition 2006; 22:947-51. [PMID: 16815676 DOI: 10.1016/j.nut.2006.05.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Revised: 04/28/2006] [Accepted: 05/01/2006] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The present study investigated the effects of hesperetin on vessel structure formation in mouse embryonic stem (mES) cells with regard to whether hesperetin acts as an antioxidant or pro-oxidant. Some flavonoids enhance antioxidant systems while increasing oxidative stress in the body. METHODS After their differentiation into endothelial-like cells for 10 d, mES cells were treated with 1 to 100 muM of hesperetin for 24 h. RESULTS Hesperetin efficiently inhibited the formation of vessel-like tubular structures consisting of platelet-endothelial cell adhesion molecule-1-immunoreactive cells and significantly (P < 0.05) increased the generation of reactive oxygen species in a concentration-dependent manner. Although glutathione (in its reduced and oxidized forms) in mES cells was not affected by hesperetin, the 8-iso-prostaglandin F2(alpha) content was decreased. In addition, cytotoxicity-induced hesperetin was not found; lactate dehydrogenase release and cell viability were determined as an index of cell damage. CONCLUSION Taken together, the present study shows that hesperetin inhibits vessel formation by pro-oxidant means and suggests its potential as an antiangiogenic agent.
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Choi EJ. The prooxidant, rather than antioxidant, acts of daidzein in vivo and in vitro: Daidzein suppresses glutathione metabolism. Eur J Pharmacol 2006; 542:162-9. [PMID: 16797001 DOI: 10.1016/j.ejphar.2006.05.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2005] [Revised: 05/08/2006] [Accepted: 05/10/2006] [Indexed: 11/17/2022]
Abstract
The present study was performed to investigate the effects of chronic administration of daidzein on lipid peroxidation and glutathione concentration in the livers and brains of rats. Male Sprague-Dawley rats were divided into two groups, one of which was fed a normal diet and the other a vitamin E-free diet. Each of these groups was divided further into three subgroups and treated either with vehicle or with daidzein administered orally at either 2 or 20 mg/day for 4 weeks. The concentrations of alpha-tocopherol in the serum and the brain increased following daidzein treatment, and these increases were significantly greater in rats maintained on a vitamin E-free diet. Daidzein significantly decreased the concentration of malondialdehyde in the organs, and this decrease was more pronounced in vitamin E-deprived rats than in those maintained on a normal diet. Although the liver glutathione concentration was not affected, daidzein treatment (20 mg/day) decreased the glutathione concentration in the brain significantly and to a similar extent in vitamin E-deprived rats and those fed normal diet. In addition the daidzein metabolite, equol, severely decreased the ratio of GSH and GSSG in primary cortical neuron cells exposed to it. Collectively, these results suggest that daidzein may act not only as an antioxidant, but also a prooxidant in brain rats, this should be in the brains of rats.
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98
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Lee HK, Kang DS, Seo IA, Choi EJ, Park HT, Park JI. Expression of tumor endothelial marker 7 mRNA and protein in the dorsal root ganglion neurons of the rat. Neurosci Lett 2006; 402:71-5. [PMID: 16707219 DOI: 10.1016/j.neulet.2006.04.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2006] [Revised: 04/01/2006] [Accepted: 04/04/2006] [Indexed: 10/24/2022]
Abstract
Tumor endothelial marker7 (TEM7) is a transmembrane protein that is highly expressed in the tumor endothelium and neurons. In the present study, the expression profile of TEM7 mRNA and protein was investigated in the dorsal root ganglion (DRG) of the rats. In situ hybridization and reverse transcription polymerase chain reaction studies revealed that TEM7 mRNA expression was localized to the neuronal population of the sensory ganglion. Immunohistochemical analysis on TEM protein with specific antibodies further supported the spatial expression patterns of TEM7 mRNA in the DRG. The temporal expression of TEM7 mRNA in the DRG demonstrated a postnatal increase of TEM7 mRNA expression. Our results indicate that TEM7 may play a role in the peripheral sensory neurons of the vertebrate nervous systems.
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Kim Y, Choi EJ, Choi CG, Kim G, Choi JH, Yoo HW, Kim JS. Characteristics of CADASIL in Korea: A novel cysteine-sparing Notch3 mutation. Neurology 2006; 66:1511-6. [PMID: 16717210 DOI: 10.1212/01.wnl.0000216259.99811.50] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To elucidate the phenotype, genotype, and MRI findings of Korean patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and mutation carriers. METHODS The authors studied 40 members of nine unrelated Korean CADASIL families. After genetic analysis of Notch3, clinical and MRI findings were correlated in 27 mutation carriers. RESULT Notch3 mutation sites were C174R (one family, n = 3), R133C (one family, n = 3), R587C (one family, n = 1), R544C (two families, n = 5), and R75P (four families, n = 15). The clinical features were typical of CADASIL, but the frequency of migraine in the Korean population appears low. MRI abnormalities were found in 54% of the mutant carriers, the most common being white matter hyperintensities. The prevalence of lacunes and microbleeds increased with patient age. Anterior temporal areas were less often involved in subjects with R75P mutations than in those where mutations occurred in other sites (p = 0.02). Gradient echo imaging identified microbleedings in 33% of mutation carriers (64% of those with abnormal MRI), whereas diffusion-weighted MRI showed abnormal findings in only one patient. Neurologic disability was related to the number of lacunar infarcts and the lesion volume of white matter hyperintensities (p < 0.001) whereas MMSE score was related to the number of lacunar infarcts (p < 0.005). CONCLUSIONS Although Korean cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) mutation carriers show similar clinical and MRI findings, these abnormalities appear less frequently than in other populations. Relatively frequent microbleedings on gradient echo imaging suggest that treatment should be individualized according to MRI findings. The novel mutation of R75P, not involving a cysteine residue, is related to less frequent involvement of the anterior temporal area, thus broadening the spectrum of CADASIL.
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Cho KR, Seo BK, Lee JY, Pisano ED, Je BK, Lee JY, Choi EJ, Chung KB, Whan Oh Y. A comparative study of 2D and 3D ultrasonography for evaluation of solid breast masses. Eur J Radiol 2005; 54:365-70. [PMID: 15899337 DOI: 10.1016/j.ejrad.2004.07.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2004] [Revised: 07/06/2004] [Accepted: 07/08/2004] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare image quality and diagnostic accuracy of 2D with 3D ultrasonography in solid breast masses. METHODS AND MATERIAL To rate image quality, two radiologists compared lesion contrast and characterization of 507 solid breast masses in 2D and 3D ultrasonography and then graded the 3D imaging in 3-point scale. To characterize the masses, the same radiologists rated the examination for clarity of margin, posterior acoustic feature, and clustered microcalcifications within a mass. In addition, the masses were assigned BI-RADS categories as proposed by the American College of Radiology, criteria using just ultrasonographic features. In the 202 pathologically confirmed cases, sensitivity, specificity, positive predictive value, negative predictive value, and false negative rate for diagnosis of breast cancer in 2D and 3D ultrasonography were assessed. Image quality and diagnostic accuracy were further evaluated according to the size of the masses. RESULTS Two observers rated 3D imaging superior to 2D imaging in terms of lesion contrast and characterization of the masses. Especially, superiority of 3D ultrasonography in terms of image quality was increasing in more than 10 mm sized masses. However, diagnostic accuracy including sensitivity, specificity, positive predictive value, negative predictive value, and false negative rate for diagnosis of breast cancer of 3D imaging was not different from 2D imaging. CONCLUSION In spite of superior image quality on 3D ultrasonography, it does not provide additional benefits to diagnostic accuracy for diagnosis of breast cancer.
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