Publications by authors named "Chung Lee"

The murine renal cell carcinoma (Renca) cells are insensitive to TGF-beta due to a lack of TGF-beta type II receptor (TbetaR-II). The objective of the present study is to determine the mechanism of this loss of sensitivity to TGF-beta in Renca cells. Renca cells were cultured and treated with 5-Aza-2'-Deoxycytidine (5-Aza), a specific inhibitor of methylation.

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The present study investigated the effect of 1-methylated beta-carbolines (harmaline, harmalol and harmine) on change in the mitochondrial membrane permeability and cell death due to reactive nitrogen species in differentiated PC12 cells. beta-Carbolines, caspase inhibitors (z-LEHD.fmk and z-DQMD.

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The effect of GSH depletion on mitochondrial damage and cell death due to mitomycin c (MMC) was assessed in small cell lung cancer (SCLC) cells. Cytotoxicity of MMC was attenuated by Tempol and dicumarol, inhibitors of the enzymatic reduction, and increased by xanthine oxidase. The MMC-induced cell death and decrease in the GSH contents in SCLC cells were inhibited by caspase inhibitors (z-DQMD.

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Background: Breast cancer is the most common form of cancer among Korean women. Only 14% of urban women and 10% of rural women in Korea, however, participated in breast cancer screening behavior in 1998 (Korean Ministry of Health & Welfare, 1999).

Purpose: The aim of this study was to evaluate the effect of community-based breast self-examination (BSE) education programs in Korea.

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The purpose of the present study was to develop and validate breast cancer risk factors, which can be used to identify women who are at a high risk of developing breast cancer. Fourteen risk factors for breast cancer were identified from extensive literature reviews and in consultation with a panel of experts. A case-control study was conducted, which aimed to validate these 14 risk factors.

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The effect of the depletion or oxidation of cellular GSH on cytotoxicity of MG132 was assessed. Viability loss and decrease in GSH contents in small cell lung cancer (SCLC) cells treated with MG132 was attenuated by caspase inhibitors (z-IETD.fmk, z-LEHD.

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Dopamine (50 or 100 microM) attenuated the nuclear damage and cell death due to 500 microM SIN-1, a donor of superoxide and nitric oxide, in differentiated PC12 cells whereas 200 microM dopamine did not depress cell death. Dopamine at 50-100 microM for a 4-h treatment did not show a significant cytotoxic effect on PC12 cells. Dopamine (100 microM) inhibited the decrease in mitochondrial transmembrane potential, cytochrome c release, activation of caspase-3, formation of reactive oxygen species, and depletion of glutathione (GSH) due to 500 microM SIN-1 in PC12 cells.

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In previous studies for the development of new anticonvulsants, we found that N-Cbz-alpha-amino-N-alkylsuccinimides exhibited significant anticonvulsant activities in the Maximal electroshock seizure (MES) and Pentylenetetrazole induced seizure (PTZ) tests, and also their anticonvulsant activities were dependent on the N-alkyl substituents existent in their structures. Based on these estimations, N-Cbz-alpha-amino-N-hydroxysuccinimide and various N-Cbz-alpha-amino-N-alkoxysuccinimides were prepared in order to develop more active anticonvulsants and to examine the effects of N-hydoxy or N-alkoxy groups on their anticonvulsant activities. The (R)- or (S)-N-Cbz-alpha-amino-N-hydroxysuccinimide and N-Cbz-alpha-amino-N-alkoxysuccinimides were prepared from the corresponding (R)- or (S)-N-Cbz-aspartic acid through the known synthetic procedures.

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Free fatty acids (FFAs), especially polyunsaturated fatty acids (PUFAs), are potent modulators of muscle-type sodium channels. It is not known if they also modulate sodium channels of sensory neurons. In this study, we investigated the effects of FFAs on the fast tetrodotoxin-sensitive (fTTX-S) and the slow tetrodotoxin-resistant (sTTX-R) sodium currents in rat dorsal root ganglion neurons.

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NRP-152 is an androgen responsive, non-tumorigenic cell line, which shows basal epithelial cell characteristics under normal growth conditions. It has been noted that NRP-152 undergoes morphological and cytoskeletal changes toward its luminal counterpart NRP-154 when it is grown under growth restrictive conditions. We have extensively investigated the details of protein change of NRP-152 during transdifferentiation using proteomic techniques.

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The effects of various nucleotides on the fast tetrodotoxin-sensitive (f-TTX-S) and the slow tetrodotoxin-resistant (s-TTX-R) sodium currents in rat dorsal root ganglion (DRG) neurons were investigated using the patch-clamp technique. Nucleoside triphosphates (NTPs; ATP, GTP, UTP and CTP) and nucleoside diphosphates (NDPs; ADP, GDP, UDP and CDP) decreased f-TTX-S current, whereas they increased s-TTX-R current, when currents were evoked by step depolarizations to 0 mV from a holding potential of -80 mV. NTPs and NDPs shifted both the conductance-voltage relationship curve and the steady-state inactivation curve in the hyperpolarizing direction in both types of sodium currents.

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In our previous studies for the development of new anticonvulsant of broad spectrum, we found that N-cbz-alpha-aminoglutarimides showed significant anticonvulsant activities of broad spectrum enough to be recommended for the new anticonvulsants and their anticonvulsant activities were dependent on their imide substituent groups. Based on these results, various N-cbz-alpha-amino-N-alkoxyglutarimides, where the imide N-H was substituted with the hydroxy and alkoxy group, were prepared and evaluated for their anticonvulsant activities using the Maximal electroshock seizure (MES) and Pentylenetetrazole induced seizure (PTZ) tests and also the rotorod test. A series of (R) or (S)-N-cbz-alpha-amino-N-alkoxyglutarimides could be prepared from the corresponding (R) or (S)-N-cbz-glutamic acid following the usual synthetic procedure.

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We present and demonstrate a simple method of pulse-amplitude equalization in a rational harmonic mode-locked semiconductor ring laser, using a dual-drive Mach-Zehnder (MZ) modulator. Pulse-amplitude equalization was achieved by adjusting the voltages applied to both arms of the modulator, such that each mode-locked pulse experiences the same transmission coefficient in the transmission curve of the modulator. With this method, amplitude-equalized pulse trains with repetition rates of ~7.

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Cartilage metabolism in response to mechanical loading is an important subject in sports science and medicine. In animal studies high-impact exercise is known to stimulate bone adaptation and increase bone mass. However, mechanical impacts potentially induce tissue swelling and occasionally degradation of connective tissues in synovium and articular cartilage.

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The purpose of this study was to measure the effect of the demonstration health promotion projects on whether knowledge, perceptions, and competencies of health care workers in health centers improved as a result of participating in the health promotion projects. A total of 1,955 community health care workers were recruited for the study. Health care workers from 18 demonstration health centers (n = 728) were assigned to the study group.

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The effect of reactive nitrogen species (RNS) against the cytotoxicity of mitomycin c (MMC) in lung epithelial cells was assessed by measuring the effect on mitochondrial membrane permeability. RNS had a differential effect against cytotoxicity of MMC depending on concentration. Viability loss in cells exposed to MMC was decreased by inhibitors of caspase-3, -8 and -9 and attenuated by antioxidants (N-acetylcysteine, dithiothreitol, ascorbate and rutin).

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Purpose: We identified and characterized unrecognized testicular secretory proteins that impact human prostate growth.

Materials And Methods: Human spermatocele fluid served as a source of testicular epididymal secretions and prostatectomy specimen benign prostatic hyperplasia stromal cells as the in vitro prostate growth promoting effects indicator. RMPI plus medium supplemented with 10% fetal bovine serum MALDI-TOF, MS FBS and ITS+ (Collaborative Research-Becton Dickinson, Bedford, Massachusetts) served as positive and negative controls, respectively.

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Phenelzine, deprenyl, and antioxidants (SOD, catalase, ascorbate, or rutin) reduced the loss of cell viability in differentiated PC12 cells treated with 250 microM MPP+, whereas N-acetylcysteine and dithiothreitol did not inhibit cell death. Phenelzine reduced the condensation and fragmentation of nuclei caused by MPP+ in PC12 cells. Phenelzine and deprenyl prevented the MPP+-induced decrease in mitochondrial membrane potential, cytochrome c release, formation of reactive oxygen species, and depletion of GSH in PC12 cells.

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The effects of diclofenac, a nonsteroidal anti-inflammatory drug (NSAID), on the fast tetrodotoxin-sensitive (TTX-S) and the slow tetrodotoxin-resistant (TTX-R) sodium currents in rat dorsal root ganglion neurons were investigated using the whole-cell patch-clamp method. Diclofenac suppressed both sodium currents in a dose-dependent manner. The apparent dissociation constants for the diclofenac suppression of TTX-S and TTX-R sodium currents were estimated to be 14 and 97 microM, respectively, at a holding potential of -80 mV.

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Purpose: Perillyl alcohol (POH) (4-isopropenyl-cyclohexenecarbinol) is a member of the monoterpenes, which are present in various fruits and vegetables. POH has been demonstrated to be cytotoxic against a variety of experimental cancer cells in vitro and in vivo. Phase I clinical trials have indicated that POH may be useful for human tumor treatment.

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The mitochondrial permeability transition is recognized to be involved in toxic and oxidative forms of cell injury. In the present study, we investigated the effect of ambroxol against the cytotoxicity of bleomycin (BLM) by looking at the effect on the mitochondrial membrane permeability in alveolar macrophages and lung epithelial cells. Alveolar macrophages or lung epithelial cells exposed to BLM revealed the loss of cell viability and increase in caspase-3 activity.

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Purpose: To examine radiation dose response for low-grade glioma (LGG) based on our institutional experience and to review the literature on this topic.

Methods And Materials: Sixty-seven patients with supratentorial low-grade nonpilocytic astrocytomas (n=36) or oligodendrogliomas (n=31) were treated with postoperative radiation therapy (RT). Twenty-seven patients (group A) received 5520 cGy; 24 patients (group B) received 5940 cGy; and 16 patients (group C) received 6375 cGy.

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In a preliminary study, we observed that TGF-beta1 induced both proliferation and growth arrest in prostatic stromal cells, depending on the concentration of TGF-beta1 used in the culture medium. In this study, we explored possible mechanisms of this dual effect of TGF-beta. Primary cultures of prostatic stromal cells, established from clinical surgical specimens and treated with low doses of TGF-beta1 (0.

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This study deals with the biological role of transforming growth factor-beta (TGF-beta) in the pathogenesis of benign prostatic hyperplasia (BPH), which is a common disorder in aging males. The two known etiological factors for BPH have been the presence of testis and aging. It is well established that androgen plays an important role in the pathogenesis of BPH in aging men.

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The aim of the study is to characterize the type of immune response in benign prostatic hyperplasia (BPH) tissue. BPH tissue-derived T cells (n = 10) were isolated, activated (PMA + ionomycin), and analyzed for intracellular reactivity with anti-IFN-gamma and IL-2, -4, -5, -6, -10, and -13, as well as TNF-alpha and -beta by four-color flow cytometry. Lymphokine release was tested using Th1/Th2 cytokine bead arrays.

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