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Eun Hee Kim

Publications and source records attributed to Eun Hee Kim.

At least 19 recordsLinked to original sources
PubMed2006

Preparation of holographic gratings of liquid crystals dispersed in polyurethane acrylates under controlled reaction conditions.

Transmission gratings of holographic polymer-dispersed liquid crystals (HPDLC) are prepared under controlled reaction conditions by adding various amounts of chain-transfer agent (CTA). The resulting films have a higher gel content with lower cross-link density, less dark reaction, less grating shrinkage with much smoother LC/polymer interfaces, smaller induction period, and fast saturation of diffraction efficiency, which shows a maximum of 95 % with 1 % CTA. An optimum LC content of 35 % is verified on the basis of morphology and reaction kinetics.

Journal Article↗
PubMed2006

Sulforaphane sensitizes tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-resistant hepatoma cells to TRAIL-induced apoptosis through reactive oxygen species-mediated up-regulation of DR5.

Sulforaphane is a chemopreventive agent present in various cruciferous vegetables, including broccoli. Here, we show that treatment with tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) in combination with subtoxic doses of sulforaphane significantly induces rapid apoptosis in TRAIL-resistant hepatoma cells. Neither TNF-alpha- nor Fas-mediated apoptosis was sensitized in hepatoma cells by cotreatment with sulforaphane, suggesting that sulforaphane can selectively sensitize cells to TRAIL-induced apoptosis but not to apoptosis mediated by other death receptors. We found that sulforaphane treatment significantly up-regulated mRNA and protein levels of DR5, a death receptor of TRAIL. This was accompanied by an increase in the generation of reactive oxygen species (ROS). Pretreatment with N-acetyl-l-cysteine and overexpression of catalase inhibited sulforaphane-induced up-regulation of DR5 and almost completely blocked the cotreatment-induced apoptosis. Furthermore, the sulforaphane-mediated sensitization to TRAIL was efficiently reduced by administration of a blocking antibody or small interfering RNAs for DR5. These results collectively indicate that sulforaphane-induced generation of ROS and the subsequent up-regulation of DR5 are critical for triggering and amplifying TRAIL-induced apoptotic signaling. We also found that sulforaphane can sensitize both Bcl-xL- and Bcl-2-overexpressing hepatoma cells to TRAIL-induced apoptosis, indicating that treatment with a combination of TRAIL and sulforaphane may be a safe strategy for treating resistant hepatomas.

Animals↗
PubMed2006

Induction of G2 arrest and apoptosis of raji cells by continuous low-dose beta irradiation with 188Re-perrhenate.

Continuous irradiation with exponentially reducing beta-rays induces cell death, known as apoptosis. The aim of this study was to investigate the G2 arrest and apoptosis caused by the beta-ray emitted by the radioisotope (188)Re. Doses of 0.4 Gy (3.7 MBq), 4 Gy (37 MBq), and 40 Gy (370 MBq), were added to Blymphoma Raji cells, and cell viability, apoptosis, and DNA cell-cycle changes were assayed. (188)Re showed time- and dose-dependent effects on cell viability and on cell apoptosis and necrosis. At a (188)Re dose of 0.4 Gy, G(2) cell-cycle arrest was observed after 16 hours, and 4,6-diamidino-2-phenylindole (DAPI) staining indicated a slow, time-dependent increase in apoptotic bodies. At a (188)Re dose of 40 Gy, DNA fragmentation was observed at 2 hours, indicative of early damage in the nucleus. In summary, our results showed that continuous irradiation with low-dose beta-rays induced G(2) arrest and progressive apoptosis, which may be characteristic mechanisms of radionuclide therapy.

Apoptosis↗
PubMed2005

A pilot study of trans-arterial injection of 166Holmium-Chitosan complex for treatment of small hepatocellular carcinoma.

Percutaneous approaches, such as percutaneous ethanol injection and radiofrequency ablation, have been most widely used for hepatocellular carcinoma patients who were not eligible for surgery. New technologies to improve the efficacy are currently needed. (166)Holmium is a neutron activated radionuclide, and has several beneficial radiophysical characteristics for internal radiation therapy. (166)Holmium-Chitosan complex, in which chitosan is chelated with (166)Holmium, was developed as a radiopharmaceutical for cancer therapy. We have conducted a pilot study to evaluate the clinical efficacy of transarterial administration of (166)Holmium-Chitosan complex in patients with a single and small (< 3 cm) hepatocellular carcinoma. (166)Holmium-Chitosan complex, at a dose of 20 mCi per cm of tumor mass-diameter, was administered through the artery that directly fed the tumor. Twelve patients were treated with a median follow-up duration of 26 (range: 12-61) months. The tumor diameter ranged between 1.5 and 2.5 cm. Ten patients (83%) had complete response and two (17%) had partial response. The median complete response duration was not reached. The median AFP level declined from 83.8 to 8.3 ng/mL within 2 months after treatment. No grade III/IV toxicity was observed. Grade I and II toxicities were observed in four patients (2 abdominal pain, 1 fever, and 1 AST/ALT elevation). No toxic death occurred. This preliminary study shows a promising and durable complete response rate with an acceptable safety profile. Further studies with greater accrual of patients are warranted.

Adult↗
PubMed2005

Sodium butyrate sensitizes human glioma cells to TRAIL-mediated apoptosis through inhibition of Cdc2 and the subsequent downregulation of survivin and XIAP.

In TNF-related apoptosis-inducing ligand (TRAIL)-resistant glioma cells, co-treatment with nontoxic doses of sodium butyrate and TRAIL resulted in a marked increase of TRAIL-induced apoptosis. This combined treatment was also cytotoxic to glioma cells overexpressing Bcl-2 or Bcl-xL, but not to normal human astrocytes, thus offering an attractive strategy for safely treating resistant gliomas. Cotreatment with sodium butyrate facilitated completion of proteolytic processing of procaspase-3 that was partially blocked by treatment with TRAIL alone. We also found that treatment with sodium butyrate significantly decreased the protein levels of survivin and X-linked inhibitor of apoptosis protein (XIAP), two major caspase inhibitors. Overexpression of survivin and XIAP attenuated sodium butyrate-stimulated TRAIL-induced apoptosis, suggesting its involvement in conferring TRAIL resistance to glioma cells. Furthermore, the kinase activities of Cdc2 and Cdk2 were significantly decreased following sodium butyrate treatment, accompanying downregulation of cyclin A and cyclin B, as well as upregulation of p21. Forced expression of Cdc2 plus cyclin B, but not Cdk2 plus cyclin A, attenuated sodium butyrate/TRAIL-induced apoptosis, overriding sodium butyrate-mediated downregulation of survivin and XIAP. Therefore, Cdc2-mediated downregulation of survivin and XIAP by sodium butyrate may contribute to the recovery of TRAIL sensitivity in glioma cells.

Apoptosis↗
PubMed2005

Rottlerin sensitizes glioma cells to TRAIL-induced apoptosis by inhibition of Cdc2 and the subsequent downregulation of survivin and XIAP.

In the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-resistant glioma cells, treatment with TRAIL in combination with subtoxic doses of rottlerin induced rapid apoptosis. While the proteolytic processing of procaspase-3 by TRAIL was partially blocked in these cells, treatment with rottlerin efficiently recovered TRAIL-induced activation of caspases. Treatment with rottlerin significantly decreased Cdc2 activity through the downregulation of cyclin A, cyclin B, and Cdc2 proteins, whereas the sensitizing effect of rottlerin on TRAIL-induced apoptosis was independent of PKCdelta activity. Furthermore, treatment with rottlerin downregulated the protein levels of survivin and X-chromosome-linked IAP (XIAP), two major caspase inhibitors. Forced expression of Cdc2 together with cyclin B attenuated rottlerin-potentiated TRAIL-induced apoptosis by over-riding the rottlerin-mediated downregulation of survivin and XIAP protein levels. Taken together, inhibition of Cdc2 activity and the subsequent downregulation of survivin and XIAP by subtoxic doses of rottlerin contribute to amplification of caspase cascades, thereby overcoming resistance of glioma cells to TRAIL-mediated apoptosis. Since rottlerin can sensitize Bcl-2- or Bcl-xL-overexpressing glioma cells but not human astrocytes to TRAIL-induced apoptosis, this combined treatment may offer an attractive strategy for safely treating resistant gliomas.

Acetophenones↗
PubMed2005

Coxiella burnetii in bulk tank milk samples, United States.

Dairy cattle are a primary reservoir of Coxiella burnetii, which causes Q fever. However, no recent nationwide studies have assessed the prevalence and risks of Q fever in dairy cattle. We report >or=94% prevalence in samples of bulk tank milk from U.S. dairy herds tested during the past 3 years.

Animals↗
PubMed2004

Involvement of c-Src kinase in the regulation of TGF-beta1-induced apoptosis.

Transforming growth factor-beta1 (TGF-beta1) is a potent inducer of apoptosis in normal hepatocytes, and acquiring resistance to TGF-beta1 may be a critical step in the development of hepatocellular carcinoma (HCC). In this study, we investigated the possible involvement of c-Src in the regulation of TGF-beta1-induced apoptosis. TGF-beta1 induced transient activation of c-Src and its subsequent caspase-mediated degradation concomitant with cell death in FaO hepatoma cells, which are sensitive to TGF-beta1. In response to TGF-beta1, activated c-Src was translocated into the cytoplasmic membrane, then relocated to the nuclei of apoptotic cells during its cleavage. In TGF-beta1-induced apoptotic cells, c-Src maintained its tight association with p85 FAK fragment cleaved by caspases, possibly contributing to focal adhesion disassembly. TGF-beta1-induced apoptosis was enhanced by either inhibition of c-Src activity using PP1 or PP2, or by overexpression of dominant-negative c-Src. In contrast, overexpression of constitutively active c-Src inhibited apoptosis suppressing TGF-beta1-induced activation of p38, JNK and caspases. In many HCC cell lines resistant to TGF-beta1, enhanced c-Src activity was detected. We hypothesize that activated c-Src in HCC may contribute to resistance against the apoptotic and/ or antiproliferative properties of TGF-beta1.

Animals↗
PubMed2004

Persistent increase of matrix metalloproteinases in cerebrospinal fluid of tuberculous meningitis.

Matrix metalloproteinase (MMP)-2 and MMP-9 were analyzed by gelatin zymography and an enzyme-linked immunosorbent assay (ELISA) in a cerebrospinal fluid (CSF) from patients with tuberculous meningitis (n=24), acute aseptic meningitis (n=23) and the control (n=10). The MMP-2 and MMP-9 levels were significantly higher in the samples from the tuberculous meningitis patients than those from either the aseptic meningitis patients or the controls. In tuberculous meningitis, the patients with late neurologic complications had higher MMP-2 and MMP-9 levels than those without. The persistent increase in the MMP-2 and MMP-9 levels was associated with the development of complications following tuberculous meningitis. Inhibiting the MMPs may be an effective strategy for preventing or reducing the complications in tuberculous meningitis.

Electrophoresis, Polyacrylamide Gel↗
PubMed2004

Cocrystallization of melaminium levulinate monohydrate.

Crystals of 2,4,6-triamino-1,3,5-triazin-1-ium levulinate (4-oxopentanoate) monohydrate, C(3)H(7)N(6)(+).C(5)H(7)O(3)(-).H(2)O, are formed via self-assembled hydrogen bonding by cocrystallization of melamine and levulinic acid. Two N-H.N hydrogen bonds and four N-H.O hydrogen bonds connect two melaminium entities such that each of two pairs of N-H.O bonds bridges two H atoms belonging to the amine groups of two different melaminium cations via the carbonyl O atom of one levulinate molecule.

Journal Article↗
PubMed2004

Roscovitine sensitizes glioma cells to TRAIL-mediated apoptosis by downregulation of survivin and XIAP.

The cytotoxic effect of the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is limited in many glioma cell lines. However, treatment with TRAIL in combination with subtoxic doses of roscovitine, a specific inhibitor of Cdc2 and Cdk2, induced rapid apoptosis in TRAIL-resistant glioma cells. Roscovitine could sensitize Bcl-2- or Bcl-xL-overexpressing glioma cells, but not human astrocytes, to TRAIL-induced apoptosis, offering an attractive strategy for safely treating resistant gliomas. Treatment with roscovitine significantly inhibited Cdc2 activity, and expression of a dominant-negative Cdc2 mutant sensitized glioma cells to TRAIL-induced apoptosis. While the proteolytic processing of procaspase-3 by TRAIL was partially blocked in U87MG and T98 glioma cells, treatment with roscovitine recovered TRAIL-induced activation of caspases very efficiently in these cells. We found that treatment with roscovitine or expression of a dominant-negative Cdc2 mutant downregulated the protein levels of survivin and XIAP, two major caspase inhibitors. Overexpression of survivin or XIAP attenuated the apoptosis induced by roscovitine and TRAIL. Taken together, these results suggest that downregulation of survivin and XIAP by subtoxic doses of roscovitine contributes to the amplification of caspase cascades, thereby overcoming glioma cell resistance to TRAIL-mediated apoptosis.

Apoptosis↗
PubMed2004

Conformational transitions and glycation of serum albumin in patients with minimal-change glomerulopathy.

BACKGROUND: There has been a lack of study on the structural changes of serum albumin in patients with minimal change disease (MCD). To determine whether glycation and/or conformational transitions of albumin are involved in the pathogenesis of albuminuria, nine patients with MCD were enrolled in a prospective follow-up study for comparison of these parameters in serum albumin during the remission and relapse of nephrotic syndrome. METHODS: Circular dichroism measurements were made with purified albumin. Ellipticities at each wavelength were transformed to mean residue ellipticity. Monosaccharide composition was analyzed by high-pH anion-exchange chromatography with pulsed amperometric detection. RESULTS: There was no difference in the proportions of alpha-helix, beta-conformation, and beta-turn of albumin between the sera of control patients and those with nephrotic syndrome. However, the proportion of the random configuration was slightly higher in the plasma albumin of patients in relapse than in those in remission. The proportion of the random configuration was lower in the albumin of the serum than in the urine of patients with nephrotic syndrome, but there was no difference in the proportions of alpha-helix, beta-conformation, and beta-tum of albumin between their plasma and urine. CONCLUSION: Our results suggest that conformational changes in albumin are involved in albuminuria in patients with MCD.

Adult↗
PubMed2004

Immunomodulatory and antitumor effects in vivo by the cytoplasmic fraction of Lactobacillus casei and Bifidobacterium longum.

The immunomodulatory and antitumor effects of lactic acid bacteria (LABs) were investigated. Cytoplasmic fraction of Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium longum were tested for the antiproliferative activity in vitro to SNUC2A, SNU1, NIH/3T3 and Jurkat cell lines by crystal violet assay. All cytoplasmic fraction suppressed proliferation of tumor cells, though L. casei and B. longum were more effective. From these results, cytoplasmic fraction of L. casei and B. longum with Y400 as a control were administered as dietary supplements to Balb/c mice for 2, and 4 consecutive wks. Administration for 4 wks enhanced the number of total T cells, NK cells and MHC class II+ cells, and CD4-CD8+ T cells in flow cytometry analysis. To determine of antitumor activity of LABs preparation in vivo, F9 teratocarcinoma cells were inoculated on mice at 14th day. Body weight was decreased with increased survival rate in all groups with the cytoplasm of LABs. Our results showed that cytoplasmic fraction of LABs had direct antiproliferative effects on tumor cell lines in vitro, effects on immune cells in vivo, and antitumor effects on tumor-bearing mice with prolonged survival periods.

3T3 Cells↗
PubMed2003

Increase in plasma matrix metalloproteinase-9 in acute stroke patients with thrombolysis failure.

BACKGROUND AND PURPOSE: Platelet-rich thrombi are resistant to thrombolytics. Matrix metalloproteinases (MMPs) may be involved in platelet aggregation and contribute to thrombolysis failure in stroke patients. METHODS: Plasma samples from 23 stroke patients who had received thrombolytics and from 47 healthy volunteers were examined for MMP-2 and MMP-9 by both enzyme-linked immunosorbent assays and zymography. RESULTS: The arteries were recanalized in 15 patients but not in the other 8. The MMP-9 plasma level was significantly higher in patients whose arteries were not recanalized. CONCLUSIONS: MMP-9 may be associated with the formation of a thrombolytics-resistant thrombus.

Acute Disease↗
PubMed2003

Transmodulation between phospholipase D and c-Src enhances cell proliferation.

Phospholipase D (PLD) has been implicated in the signal transduction pathways initiated by several mitogenic protein tyrosine kinases. We demonstrate for the first time that most notably PLD2 and to a lesser extent the PLD1 isoform are tyrosine phosphorylated by c-Src tyrosine kinase via direct association. Moreover, epidermal growth factor induced tyrosine phosphorylation of PLD2 and its interaction with c-Src in A431 cells. Interaction between these proteins is via the pleckstrin homology domain of PLD2 and the catalytic domain of c-Src. Coexpression of PLD1 or PLD2 with c-Src synergistically enhances cellular proliferation compared with expression of either molecule. While PLD activity as a lipid-hydrolyzing enzyme is not affected by c-Src, wild-type PLDs but not catalytically inactive PLD mutants significantly increase c-Src kinase activity, up-regulating c-Src-mediated paxillin phosphorylation and extracellular signal-regulated kinase activity. These results demonstrate the critical role of PLD catalytic activity in the stimulation of Src signaling. In conclusion, we provide the first evidence that c-Src acts as a kinase of PLD and PLD acts as an activator of c-Src. This transmodulation between c-Src and PLD may contribute to the promotion of cellular proliferation via amplification of mitogenic signaling pathways.

Animals↗
PubMed2003

Effects of beta-radiation using a holmium-166 coated balloon on neointimal hyperplasia in a porcine coronary stent restenosis model.

Brachytherapy is a promising method of preventing and treating coronary stent restenosis. The present study was designed to observe the therapeutic effects of a radioactive balloon loaded with Holmium-166 ((166)Ho) in a porcine coronary stent restenosis model. A radioisotope of (166)Ho was coated onto the balloon surface using polyurethane (20 Gy at 0.5 mm depth). Stent overdilation injuries were induced in 2 coronary arteries in each pig (n=8). Four weeks after the injury, control balloon dilation was performed in one coronary artery (Group I) and radiation therapy using the (166)Ho coated balloon in the other coronary artery (Group II) in each pig. Follow-up coronary angiography and histopathologic assessment were performed at 4 weeks after the radiation therapy or the control balloon dilations. With regard to complete blood cell counts, liver function tests, lipid profiles and coagulation tests, there were no differences between the baseline and after radiation. On quantitative coronary angiographic analysis, reference and target artery diameter showed no differences between the 2 groups before, or 4 and 8 weeks after stenting. On histopathologic analysis of groups I and II, the injury score was 1.34+/-0.09 and 1.32+/-0.10, the area of internal elastic lamina was 4.99+/-0.17 mm(2) and 4.82+/-0.20 mm(2), and the luminal area was 3.20+/-0.10 mm(2) and 3.45+/-0.14 mm(2), respectively (p=NS). The neointimal area was 1.78+/-0.11 mm(2) in group I and 1.36+/-0.12 mm(2) in group II (p=0.017), and the histopathologic area of stenosis was 35.1+/-1.6% in group I and 27.6+/-1.9% in group II (p=0.005). In conclusion, beta-radiation of the stented porcine coronary artery using a radioactive (166)Ho coated balloon inhibited stent restenosis without any side effects.

Animals↗
PubMed2003

Intercellular adhesion molecule-1 polymorphisms in Korean patients with Behcet s disease.

Intercellular adhesion molecule-1 (ICAM-1) is expressed on vascular endothelial cells and its expression increases during the inflammatory response in patients with active Behcet's disease (BD). The ICAM1 gene mutations are associated with BD in Caucasians, but clinical features of the mutation phenotype are unknown. We analyzed ICAM1 polymorphisms in Korean BD patients to determine if there was an association between particular mutations and clinical symptoms. The prevalence of ICAM1R241G and ICAM1K469E polymorphisms was determined among 197 patients with BD and 248 healthy controls using BsrG1 and BstU1 PCR-RFLP. The frequency of both genotypes ICAM1469 * K/ * E and ICAM-1469 * E/ * E was significantly higher in BD patients compared with controls (66.0% vs 52.4%, p=0.004, OR=1.28, 95% CI 1.08-1.50) and the allele frequency of ICAM1469 * E was higher in patients with skin lesions (0.41), genital ulcers (0.41), vasculitis (0.43), ocular lesions (0.41) and arthritis (0.39) than in controls (0.31). Only one heterozygote, ICAM1241G/R, was detected in BD patients but the ICAM1241 * R mutation was not found in any of the 248 healthy controls. These results show that the ICAM1 mutation is associated with BD susceptibility, and is another genetic risk factor for BD among the Korean population.

Adult↗