Seung Lee

Publications (3)7.13 Total impact

• Article: Inhibitory effects of deoxypodophyllotoxin from Anthriscus sylvestris on human CYP2C9 and CYP3A4.

  Sang Kyu Lee, Yoon Kim, Changbae Jin, Seung Ho Lee, Mi Jeong Kang, Tae Cheon Jeong, Seo Young Jeong, Dong-Hyun Kim, Hye Hyun Yoo
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  ABSTRACT: Deoxypodophyllotoxin (DPT) is a bioactive compound of Anthriscus sylvestris (Apiaceae). In the present study, the inhibition of cytochrome P450 (CYP) by DPT was evaluated in human liver microsomes (HLM) and the baculovirus-insect cell-expressed human CYPs using a cocktail probe assay. When a mixture of specific CYP substrates was incubated with DPT in HLM, CYP2C9-catalyzed diclofenac 4-hydroxylation and CYP3A4-catalyzed midazolam 1-hydroxylation were strongly inhibited by DPT, with IC (50) values of 6.3 and 9.2 microM, respectively. The Lineweaver-Burke plots for the inhibition of CYP2C9 and CYP3A4 in HLM and baculovirus-insect cell-expressed human CYPs were consistent with a competitive type of inhibition. From these results, DPT was characterized to be a competitive inhibitor of CYP2C9 and CYP3A4, with K(i) values of 3.5 and 10.8 microM in HLM and 24.9 and 3.5 microM in baculovirus-insect cell-expressed human CYPs, respectively.
  Planta Medica 12/2009; 76(7):701-4. · 2.15 Impact Factor
• Article: Panoramic endoluminal display with minimal image distortion using circumferential radial ray-casting for primary three-dimensional interpretation of CT colonography.

  Seung Soo Lee, Seong Ho Park, Jin Kook Kim, Namkug Kim, Jeongjin Lee, Beom Jin Park, Young Jun Kim, Min Woo Lee, Ah Young Kim, Hyun Kwon Ha
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  ABSTRACT: The purpose of this study was to develop a panoramic endoluminal display technique, the band view, which causes minimal image distortion, and to determine its feasibility as a time-efficient primary three-dimensional review method of CT colonography (CTC). Image distortion was compared between the band view and four other three-dimensional review modes using ten 10-mm and ten 20-mm electronically generated polyps. Diagnostic performance and interpretation time were compared between the band view and the conventional endoluminal view by two independent readers in 52 patients who underwent CTC and colonoscopy on the same day. Mean image distortion index values, in which 1 indicates no distortion and the larger value represents greater distortion, were significantly smaller with the band view (1.03 and 1.01 for 10-mm and 20-mm polyps, respectively) than with the filet view (1.65 and 1.55) or the virtual colon dissection (3.27 and 3.85) (P < or = 0.004). The sensitivity and specificity for detecting adenomatous polyps > or = 6 mm did not differ, but the mean interpretation time was significantly shorter with the band view than with the conventional endoluminal view by 1.8 and 4.5 minutes in readers 1 and 2, respectively (P < 0.0001). The band view can be a time-efficient alternative for primary three-dimensional review of CTC.
  European Radiology 03/2009; 19(8):1951-9. · 3.22 Impact Factor
• Article: Down-regulation of carbonic anhydrase isoenzymes in nasal polyps.

  Tae Hoon Kim, Heung Man Lee, Seung Hoon Lee, Ha Kyun Kim, Jung Hoon Lee, Kyoung Ho Oh, Sang Hag Lee
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  ABSTRACT: Carbonic anhydrase (CA) is a zinc metalloenzyme that participate in the biological processes of various fluid transporting epithelia, including ion and water transport. CA may thus play a role in the pathophysiology of normal nasal mucosa and nasal polyp. We evaluated the expression and pattern of distribution of mRNAs and proteins for CA isoenzymes in normal nasal mucosa and polyps. This was a controlled, prospective study. The expression levels of 11 isoenzyme genes (I, II, III, IV, VA, VB, VI, VII, IX, XII, XIV) were evaluated in normal mucosa and polyps using semiquantitative reverse-transcriptase polymerase chain reaction. The expression and pattern of distribution of CA I, II, and IX were also investigated using immunohistochemistry and Western blot. mRNAs for the 11 CA isoenzymes were detected in all normal nasal mucosa and polyps tested. Their expression levels were decreased in nasal polyp in comparison with normal nasal mucosa. CA I was detected in the epithelial cells, endothelial cells, and submucosal gland of normal nasal mucosa, but only in the endothelial cells in nasal polyp. CA II in normal mucosa was intensely expressed in the submucosal gland cells and CA IX was noted in the cytoplasm and plasma membrane of epithelial cells and submucosal glands. However, these findings were not found in nasal polyp. Western blot also showed differences in their expression levels. These results indicate that CA may participate in the physiology of normal nasal mucosa, but also suggest that altered their expression in nasal polyps may cause impaired electrolyte and water transport across the epithelial cells.
  The Laryngoscope 08/2008; 118(10):1856-61. · 1.75 Impact Factor