Chul Hoon Lee

Although resistance of Helicobacter pylori to clarithromycin is a major cause of failure of eradication therapies, little information is available regarding gene mutations of clarithromycin-resistant primary and secondary H. pylori isolates in Korea. In the present study, we examined gene mutations of H. pylori 23S rRNA responsible for resistance to clarithromycin. DNA sequences of the 23S rRNA gene in 21 primary clarithromycin-resistant and 64 secondary clarithromycin-resistant strains were det

Atopic dermatitis (AD) is an allergic, inflammatory skin disease characterized by chronic eczema and mechanical injury to the skin, caused by scratching. Korean red ginseng (RG) has diverse biological activities, but the molecular effects of RG on allergic diseases, like AD, are unclear. The present study was designed to investigate whether RG inhibits 1-chloro-2,4-dinitrobenzene (DNCB)-induced AD in a mouse model. DNCB was applied topically on the dorsal surface of Balb/c mice to induce AD-like

Yoo SW, Chung EJ, Kim SY, Ko JH, Baek HS, Lee HJ, Oh SH, Jeon SC, Lee WS, Park CK, Lee CH. Multiple extramedullary relapses without bone marrow involvement after second allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia. Abstract: EMR without BM involvement after allogeneic HSCT is extremely rare, especially in children; only a few cases have been reported. A two‐yr‐old boy was diagnosed with AML (M4) and underwent allogeneic HSCT in first complete remission with BM fr

We recently showed that polylysine, the polymer of lysines, retains anti-prion activity. Although the effectiveness of prion inhibition by polylysine was demonstrated with the regimen tolerated in mice, a determination of quantitative polylysine toxicity is necessary to precisely address the in vivo toxicity level of polylysine. In this communication, we report the results of body weight monitoring and hematologic tests performed in CD-1 mice that received two different tolerable dosages of poly

To generate new scaffold candidates as highlyselective and potent cyclin-dependent kinase (CDK) inhibitors,structure-based drug screening was performed utilizing 3Dpharmacophore conformations of known potent inhibitors. Asa result, CR229 (6-bromo-2,3,4,9-tetrahydro-carbolin-1-one)was generated as the hit-compound. A computational dockingstudy using the X-ray crystalographicstructure of CDK2 incomplex with CR229 was evaluated. This predicted bindingmode study of CR229 with CDK2 demonstrated that

In the course of screening for a novel inhibitorof CDC2, HY558-1 was isolated from a culture broth ofPenicillium minioluteum F558. Moreover, it was found thatHY558-1 had an effect on both the cell cycle regulation andapoptosis of human cervical adenocarcinoma HeLa cells. Aflow cytometric analysis of HeLa cells revealed appreciablecell cycle arrest at the G1 and G2/M phases following treatmentwith HY558-1. Furthermore, DNA fragmentation due toapoptosis was observed in HeLa cells treated with HY55

In association with the Blandford-Znajek mechanism for rotational energy extraction from Kerr black holes, it is of some interest to explore how much magnetic flux can actually penetrate the horizon at least in idealized situations. For the completely uncharged Kerr hole case, it has been known for some time that the magnetic flux gets entirely expelled when the hole is maximally rotating. In the mean time, it is also known that when the rotating hole is immersed in an originally uniform magneti

The roots of Aralia continentalis (AC) have beenused traditionally in Korean as a folk medicine for anti-inflammation and as an anti-rheumatic. In this study, we reportthat the ethyl acetate-soluble fraction (ACE) of the methanolicextract of AC root inhibited the cel growth of various humancancer cel lines and induced apoptosis of HL-60, humanpromyelocytic leukemia cells. Its IC50 values on growth inhibitionwere estimated to be 56.3g/ml on HL-60, 87.2g/ml onHepG2, 93.2g/ml on HeLa, 135.5g/ml on

To elucidate the action mechanism of MCS-C2, a novel analogue of toyocamycin and sangivamycin, its effect on the expression of cell cycle-related proteins in the human myelocytic leukemia cell line HL-60 was examined using Western blotting and a flow cytometric analysis. MCS-C2, a selective inhibitor of cyclin-dependent kinases, was found to inhibit cell growth in a time- and dose-dependent manner, and inhibits cell cycle progression by inducing the arrest at G1 and G2/M phases, in HL-60 cells.

In the search for a novel cytotoxic substance frommedicinal plants, HY53 (C17H32O2N2; molecular weight 296)was isolated from the leaves of Pata de Vaca (Bauhiniaforficatadose-dependent maner when treated with 0.07 to 0.40 mMHY53 for 24 h (IC50: 0.13 mM). Furthermore, nuclear DAPIstaining revealed the typical nuclear features of apoptosis inthe HepG2 cells exposed to 0.27 mM HY53, whereas a flowcytometric analysis of the HepG2 cells using propidium iodideshowed that the apoptotic cel population i

We examined the in vivo efficacy of ultra-high molecular weight poly-γ-glutamic acid (UHMW γ-PGA) for wound healing. The wound area was measured by a ruler and documented by digital photography before the animals were sacrificed at days 8 and 16 post wounding. The areas of wounds treated with UHMW γ-PGA were significantly decreased on days 8 and 16, as compared with those receiving a control treatment, and more than 70% of the UHMW γ-PGAtreated area was repaired by day 8. Hematoxylin and eosin s

We investigated the effect of ultra-high molecular weight poly-γ-glutamic acid (UHMW γ-PGA) on hair loss in vitro and in vivo. 5-Alpha reductase is an enzyme that metabolizes the male hormone testosterone into dihydrotestosterone. By performing an in vitro experiment to analyze the inhibitory effects of UHMW γ-PGA on 5-alpha reductase activity, we determined that UHMW γ-PGA did in fact inhibit 5-alpha reductase activity, indicating the use of UHMW γ-PGA as a potential 5-alpha reductase inhibitor