576
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Sung JY, Lee SY, Min DS, Eom TY, Ahn YS, Choi MU, Kwon YK, Chung KC. Differential activation of phospholipases by mitogenic EGF and neurogenic PDGF in immortalized hippocampal stem cell lines. J Neurochem 2001; 78:1044-53. [PMID: 11553678 DOI: 10.1046/j.1471-4159.2001.00491.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In several neuronal systems, nerve growth factor (NGF) and platelet-derived growth factor (PDGF) act as neurogenic agents, whereas epidermal growth factor (EGF) acts as a mitogenic agent. Hippocampal stem cell lines (HiB5) immortalized by the expression of a temperature-sensitive SV40 large T antigen also respond differentially to EGF and PDGF. While EGF treatment at the permissive temperature induces proliferation, the addition of PDGF induces differentiation at the non-permissive temperature. However, the mechanism responsible for these different cellular fates has not been clearly elucidated. In order to clarify possible critical signaling events leading to these distinct cellular outcomes, we examined whether either EGF or PDGF differentially induces the activation of phospholipases, such as phospholipase A(2) (PLA(2)), C (PLC), or D (PLD). Although EGF stimulation did not induce phospholipases, PDGF caused a rapid and transient activation of PLC and PLD, but not PLA(2). When the activation of PLC or PLD was blocked, the neurite outgrowth induced by PDGF was significantly inhibited. Although the activation of PLD occurred faster than PLC, blocking of PLD activity by transient expression of lipase-inactive mutants did not inhibit the induction of PLC activity by PDGF. These results suggest that the differential activation of phospholipases may play an important role in signal transduction by mitogenic EGF and neurotrophic PDGF in HiB5 neuronal hippocampal stem cells. In particular, the activation of phospholipase C and D may contribute to neuronal differentiation by neurogenic PDGF in the HiB5 cells.
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577
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Lee SY, Shi JQ. Maximum likelihood estimation of two-level latent variable models with mixed continuous and polytomous data. Biometrics 2001; 57:787-94. [PMID: 11550929 DOI: 10.1111/j.0006-341x.2001.00787.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Two-level data with hierarchical structure and mixed continuous and polytomous data are very common in biomedical research. In this article, we propose a maximum likelihood approach for analyzing a latent variable model with these data. The maximum likelihood estimates are obtained by a Monte Carlo EM algorithm that involves the Gibbs sampler for approximating the E-step and the M-step and the bridge sampling for monitoring the convergence. The approach is illustrated by a two-level data set concerning the development and preliminary findings from an AIDS preventative intervention for Filipina commercial sex workers where the relationship between some latent quantities is investigated.
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578
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Ahn HC, Lee SY, Kim JW, Son WS, Shin CG, Lee BJ. Binding aspects of baicalein to HIV-1 integrase. Mol Cells 2001; 12:127-30. [PMID: 11561722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) integrase is an essential enzyme in the life cycle of the virus. It is responsible for catalyzing the insertion of the viral genome into the host cell chromosome. This integrase is an attractive target for the design of a HIV antiviral drug, because integrase has no human counterpart. In order to know the interaction mode of HIV-1 integrase with its inhibitor, we investigated the effect of the inhibitor, baicalein, on the conformation of the HIV-1 integrase catalytic domain [IN-(50-212/F185K)] using fluorescence and circular dichroism (CD) spectroscopy. We found that baicalein binds to the hydrophobic region of the HIV-1 integrase catalytic core domain. This binding of baicalein induces the conformational change of the enzyme. We also found that the binding ratio of baicalein to the HIV-1 integrase catalytic domain is 2:1.
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579
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Lee JM, Kwon H, Jeong H, Lee JW, Lee SY, Baek SJ, Surh YJ. Inhibition of lipid peroxidation and oxidative DNA damage by Ganoderma lucidum. Phytother Res 2001; 15:245-9. [PMID: 11351361 DOI: 10.1002/ptr.830] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Reactive oxygen species (ROS), such as superoxide anions and hydroxyl radicals, are associated with carcinogenesis and other pathophysiological conditions. Therefore, elimination or inactivation of ROS or inhibition of their excess generation may be beneficial in terms of reducing the risk for cancer and other diseases. Ganoderma lucidum has been used in traditional oriental medicine and has potential antiinflammatory and antioxidant activities. In the present study, we tested the amino-polysaccharide fraction (designated as 'G009') from Ganoderma lucidum for the ability to protect against oxidative damage induced by ROS. G009 significantly inhibited iron-induced lipid peroxidation in rat brain homogenates and showed a dose-dependent inactivation of hydroxyl radicals and superoxide anions. It also reduced strand breakage in phiX174 supercoiled DNA caused by UV-induced photolysis of hydrogen peroxide and attenuated phorbol ester-induced generation of superoxide anions in differentiated human promyelocytic leukaemia (HL-60) cells. These findings suggest that G009 from Ganoderma lucidum possesses chemopreventive potential.
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580
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Min YS, Jeong JH, Choi YM, Lee BC, Huh IH, Lee SY, Sohn UD. The influences of extremely low frequency magnetic fields on clonidine-induced sleep in 2-day-old chicks. JOURNAL OF AUTONOMIC PHARMACOLOGY 2001; 21:197-203. [PMID: 11952875 DOI: 10.1046/j.1365-2680.2001.00227.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
1. It has been shown that magnetic fields (MFs) affect a variety of biological effects in animal brains. There have been few experiments on the effects of MFs on sleep. Therefore, we investigated whether extremely low frequency (ELF) MFs affect the sleep induced by clonidine, a central alpha(2)-adrenoceptor agonist. Clonidine produced dose-related increase of the sleeping time and dose-related decrease of the onset time in 2-day-old chicks. 2. Exposure of chicks to MFs (5, 10, 20 G; for 3, 6, 9, 12 h) significantly increased the clonidine-induced sleep time as a direct function of intensity and duration of MF application. Clonidine reduced noradrenaline or tyrosine in the brain, an effect which was not further changed in animals exposed to MF. 3. To determine whether the gamma amino butyric acid A (GABA(A))/benzodiazepine (BZD) receptor system is involved in the decrease in clonidine-induced sleep caused by activation of central alpha(2)-adrenergic systems, we examined exposure of chicks to the effects of the BZD receptor antagonist flumazenil (0.5 mg kg(-1), i.p.) and GABA(A) antagonist bicuculline (0.1 mg kg-1, i.p.) on clonidine-induced sleep. Bicuculline and flumazenil inhibited the increase of clonidine-induced sleep time by MFs. Clonidine or MFs did not change GABA levels in the brain. 4. These results suggest that MFs can increase clonidine-induced sleep via a change of GABA(A) and BZD receptor system irrespective of the concentration of GABA or noradrenaline in the brain of 2-day-old chicks.
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581
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Kim KS, Noh BK, Kim DY, Lee SY, Cho BH. Thin paraumbilical perforator-based cutaneous island flap for scrotal resurfacing. Plast Reconstr Surg 2001; 108:447-51. [PMID: 11496189 DOI: 10.1097/00006534-200108000-00026] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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582
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Abstract
BACKGROUND Buckwheat flour (BF) is known as a potent food allergen. Sensitization to it usually occurs by ingestion but also by inhalation in occupational or domestic exposure. Buckwheat chaff-stuffed pillows (BCP) can be contaminated with BF during the process of pilling, and many Korean children and adults use BCP for health reasons. METHODS AND RESULTS We here present three cases of BF allergy in children using BCP, who had been treated as nonatopic asthmatics after undergoing the routine allergy skin tests and serologic tests. We took careful clinical histories, and performed skin prick tests (SPT), the radioimmunoassay (RIA) for specific IgE, the BCP-elimination test, the BF bronchial provocation test, and IgE Western blot. All three children showed positive skin reactions to BF, but none of them had positive reactions to house-dust mites. Nocturnal asthmatic symptoms were improved during 7 days of BCP elimination, and asthmatic responses were observed by bronchial provocation tests with homemade BF extract. Serum BF-specific IgE antibodies and several IgE-binding proteins were detected by RIA and Western blot analysis, respectively. CONCLUSIONS Thus, a small amount of BF attached to BCP can induce BF sensitization, and BCP should be considered a main cause of childhood nocturnal asthma in those asthmatics exposed to these pillows.
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583
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Haney SA, Xu J, Lee SY, Ma CL, Duzic E, Broach JR, Manfredi JP. Genetic selection in Saccharomyces of mutant mammalian adenylyl cyclases with elevated basal activities. Mol Genet Genomics 2001; 265:1120-8. [PMID: 11523785 DOI: 10.1007/s004380100512] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We show that co-expression of rat Galphas together with type I, II, IV, or VI mammalian adenylyl cyclase (AC) can suppress the growth defect of cyr1 strains of Saccharomyces cerevisiae, which lack a functional endogenous AC. Complemention of cvr1 is not observed in the absence of Galphas, indicating that the mammalian ACs retain their normal regulatory behavior in yeast. Selection for Galphas-independent growth of (cyr1 strains expressing type IV AC yielded several ACIV mutants with enhanced basal activity, each of which had a single amino acid substitution in the conserved C1a or C2a region of the protein. Expression of two of the mutant ACs in HEK293 cells resulted in increased levels of cAMP and elevated adenylyl cyclase activity. Further selection for reverting mutations in one of these constitutively active AC mutants yielded three independent intragenic suppressor mutations. The distribution of the activating and suppressor mutations throughout both C1a and C2a is consistent with a model in which the enhanced basal activity results from an increase in the affinity between C1a and C2a. These results demonstrate the utility of Saccharomyces as a tool for the identification of informative mutant forms of mammalian ACs.
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584
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Hsiao TY, Liu CM, Hsu CJ, Lee SY, Lin KN. Inducing vocal register transition in an in vivo evoked phonation canine model. J Formos Med Assoc 2001; 100:543-7. [PMID: 11678005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Abstract
BACKGROUND AND PURPOSE The nature of vocal registers is still a subject of controversy. The purpose of this study was to demonstrate the induction of timbre transition of vocal register in an in vivo evoked phonation canine model and thereby confirm vocal register transition as a laryngeal event. MATERIALS A canine midbrain stimulation evoked phonation model was used in this study. To repeat a low-pitched evoked phonation in the model, the low activity of the thyroarytenoid (TA) muscle and coordinate actions of other intrinsic laryngeal muscles were kept in a consistent condition by stimulating the same midbrain point with the same electric current intensity at the same timing in the respiratory cycle. The cricothyroid (CT) muscle was activated with an electrical current delivered directly to the muscle during the evoked phonation. Under constant subglottal pressure, CT muscle activity was varied while changes in vocal register of the evoked phonation were monitored. RESULTS The fundamental frequency (F0) of the evoked phonation increased as the stimulating current to the CT muscle increased. In addition to the increase in F0, data collected from six animals demonstrated that timbre register transition was induced by a stepwise increase of current to the CT muscle. The abrupt escalation of F0 and sudden change in sound quality, which could be verified perceptually, manifested the register transition. Frequency spectrum analysis showed that the sound in the modal register contained abundant harmonics that were different from those of the sound in the falsetto register, which contained fewer harmonics. CONCLUSION The results of this study indicated that intrinsic laryngeal muscles (especially CT and TA muscle interactions) regulate timbre-register transition in a canine model.
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585
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Arteaga-Solis E, Gayraud B, Lee SY, Shum L, Sakai L, Ramirez F. Regulation of limb patterning by extracellular microfibrils. J Cell Biol 2001; 154:275-81. [PMID: 11470817 PMCID: PMC2150751 DOI: 10.1083/jcb.200105046] [Citation(s) in RCA: 189] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
To elucidate the contribution of the extracellular microfibril-elastic fiber network to vertebrate organogenesis, we generated fibrillin 2 (Fbn2)-null mice by gene targeting and identified a limb-patterning defect in the form of bilateral syndactyly. Digit fusion involves both soft and hard tissues, and is associated with reduced apoptosis at affected sites. Two lines of evidence suggest that syndactily is primarily due to defective mesenchyme differentiation, rather than reduced apoptosis of interdigital tissue. First, fusion occurs before appearance of interdigital cell death; second, interdigital tissues having incomplete separation fail to respond to apoptotic clues from implanted BMP-4 beads. Syndactyly is associated with a disorganized matrix, but with normal BMP gene expression. On the other hand, mice double heterozygous for null Fbn2 and Bmp7 alleles display the combined digit phenotype of both nullizygotes. Together, these results imply functional interaction between Fbn2-rich microfibrils and BMP-7 signaling. As such, they uncover an unexpected relationship between the insoluble matrix and soluble factors during limb patterning. We also demonstrate that the Fbn2- null mutation is allelic to the recessive shaker-with-syndactyly (sy) locus on chromosome 18.
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586
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Chung YM, Park KJ, Choi SY, Hwang SB, Lee SY. Hepatitis C virus core protein potentiates TNF-alpha-induced NF-kappaB activation through TRAF2-IKKbeta-dependent pathway. Biochem Biophys Res Commun 2001; 284:15-9. [PMID: 11374864 DOI: 10.1006/bbrc.2001.4936] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Previous work has implicated that the core protein of hepatitis C virus (HCV) may play a modulatory effect on NF-kappaB activation induced by TNF-alpha. However, it is unclear how HCV core protein modulates TNF-alpha-induced NK-kappaB activation. Here we show that overexpression of HCV core protein potentiates NF-kappaB activation induced by TNF-alpha. Expression of dominant negative form of TRAF2 inhibits the synergistic effects of HCV core protein on NF-kappaB activation, suggesting that HCV core protein potentiates NF-kappaB activation through TRAF2. Moreover, we demonstrate that HCV core protein potentiates TRAF2-mediated NF-kappaB activation via IKKbeta. In addition, HCV core protein associates with TNF-R1-TRADD-TRAF2 signaling complex, resulting in synergistically activation of NF-kappaB induced by TNF-alpha. Thus, these observations indicate that HCV core protein may play an important role in the regulation of the cellular inflammatory and immune responses through NF-kappaB.
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587
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Choi YH, Kim KB, Kim HH, Hong GS, Kwon YK, Chung CW, Park YM, Shen ZJ, Kim BJ, Lee SY, Jung YK. FLASH coordinates NF-kappa B activity via TRAF2. J Biol Chem 2001; 276:25073-7. [PMID: 11340079 DOI: 10.1074/jbc.m102941200] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
FLASH is a protein recently shown to interact with the death effector domain of caspase-8 and is likely to be a component of the death-inducing signaling complex in receptor-mediated apoptosis. Here we show that antisense oligonucleotide-induced inhibition of FLASH expression abolished TNF-alpha-induced activation of NF-kappaB in HEK293 cells, as determined by luciferase reporter gene expression driven by a NF-kappaB responsive promoter. Conversely, overexpression of FLASH dose-dependently activated NF-kappaB, an effect suppressed by dominant negative mutants of TRAF2, NIK, and IKKalpha, and partially by those of TRAF5 and TRAF6. TRAF2 was co-immunoprecipitated with FLASH from the cell extracts of HEK293 cells or HeLa cells stably expressing exogenous FLASH (HeLa/HA-FLASH). Furthermore, serial deletion mapping demonstrated that a domain spanning the residues 856-1191 of FLASH activated NF-kappaB as efficiently as the full-length and could directly bind to TRAF2 in vitro and in the transfected cells. Taken together, these results suggest that FLASH coordinates downstream NF-kappaB activity via a TRAF2-dependent pathway in the TNF-alpha signaling.
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588
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Lee JM, Han YM, Kim CS, Lee SY, Lee ST, Yang DH. Fluoroscopic-guided covered metallic stent placement for gastric outlet obstruction and post-operative gastroenterostomy anastomotic stricture. Clin Radiol 2001; 56:560-7. [PMID: 11446754 DOI: 10.1053/crad.2001.0700] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
AIM To evaluate the feasibility and safety of fluoroscopic-guided covered metallic stent placements in providing palliative care for patients with inoperable malignant gastric outlet obstruction. MATERIALS AND METHODS Under fluoroscopic guidance, placement of self-expandable, covered stents was attempted in 20 patients with inoperable or recurrent gastric cancer (age range 36-79 years). All patients had inoperable gastric outlet obstruction, 13 with native anatomy and seven with post-operative anatomy (gastrointestinal anastomotic sites). All patients had intolerance to oral alimentation and/or vomiting after ingestion. Success was defined both technically and clinically. RESULTS The placement of the stent was technically successful in 18 patients and failed in two patients (technical success: 90%). The cause of the technical failures was an inability to negotiate the guide wire through the obstruction sites in spite of the use of both fluoroscopic and endoscopic guidance. After stent placement, 15 patients were able to ingest at least liquids and had a markedly decreased incidence of vomiting (clinical success: 75%). During the mean follow-up of 6 weeks, there have been no stent reocclusion and no life-threatening complications except migration of two stents in one patient. CONCLUSION Fluoroscopically guided covered metallic stent placement appears to be valuable for the palliative treatment of malignant obstruction of gastric outlet and post-operative gastrointestinal anastomoses.
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589
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Abstract
BACKGROUND Hemangiomas of the nasal tip, the so-called Cyrano nose, are often deep, disfiguring, and persistent. OBJECTIVE To evaluate the effect of treatment with pulsed dye laser on Cyrano nose. METHODS A 3-month-old boy with hemangioma of the nasal tip of 1-months duration underwent six sessions of pulsed dye laser treatment with a 7 mm collimated beam at fluences of 5.75-6.5 J/cm2, 6 weeks apart. RESULTS Initial improvement was noted after two treatments, and the lesion showed a marked reduction in size and improvement in color over a total treatment period of 9 months. CONCLUSION Treatment with the 585 nm pulsed dye laser should be considered in the management of infants with mild to moderate degrees of nasal tip hemangiomas since it effectively reduces the lesions with minimal adverse effects.
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590
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Yoshizaki T, Horikawa T, Qing-Chun R, Wakisaka N, Takeshita H, Sheen TS, Lee SY, Sato H, Furukawa M. Induction of interleukin-8 by Epstein-Barr virus latent membrane protein-1 and its correlation to angiogenesis in nasopharyngeal carcinoma. Clin Cancer Res 2001; 7:1946-51. [PMID: 11448908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
PURPOSE The EBV latent membrane protein-1 (LMP-1) is a multifunctional protein. Recently, the contribution of LMP-1 to the metastasis of nasopharyngeal carcinoma (NPC) has been suggested. Angiogenesis is a key step for metastasis. Thus, the association of LMP-1 to neovascularization of NPC was examined in this study. EXPERIMENTAL DESIGN The association of LMP-1 to angiogenesis in 39 patients with NPC was evaluated by immunohistochemical study, and then induction of angiogenic factors by LMP-1 was examined by ELISA and luciferase reporter assay. RESULTS In an immunohistochemical study, the expression of LMP-1 was significantly correlated to microvessel counts (P = 0.0003), suggesting that LMP-1 may induce some angiogenic factors. Therefore, we studied the relationship between LMP-1 expression and interleukin-8 (IL-8), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF) expression by immunohistochemical analysis. IL-8, VEGF, and bFGF expression were correlated to microvessel counts, but only IL-8 expression was significantly correlated to LMP-1 expression (P < 0.0001). Transfection with LMP-1 expression plasmid induced IL-8 protein expression in C33A cells. The expression of LMP-1 transactivated IL-8 promoter, as demonstrated by IL-8 promoter luciferase reporter assay. Mutation of the nuclear factor kappaB responsive element in the IL-8 promoter region completely abolished transactivation by LMP-1, whereas mutation of the activator protein responsive element did not affect promoter activity. CONCLUSION These results suggested that LMP-1 induces expression of IL-8 through the nuclear factor kappaB binding site, which may contribute in part to angiogenesis in NPC.
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591
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Ho CT, Vijayaraghavan TV, Lee SY, Tsai A, Huang HM, Pan LC. Flexural behaviour of post-cured composites at oral-simulating temperatures. J Oral Rehabil 2001; 28:658-67. [PMID: 11422699 DOI: 10.1046/j.1365-2842.2001.00734.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Post-curing treatments have been known to improve the mechanical stability of visible light-cured composites. After individual post-curing treatment, the flexural strength (FS) of four commercial direct/indirect placement composite materials which differ greatly in composition [oligocarbonate dimethacrylate (OCDMA)-based Conquest C & B (CQT), Bisphenol-A glycidyl dimethacrylate (BisGMA)-based Charisma, urethane dimethacrylate (UDMA)-based Concept (CCT), and BisGMA/UDMA-based Dentacolor] was evaluated under water in the temperature range of 12-50 degrees C. A control series was tested in air at room temperature (25 +/- 1 degrees C). Data were analysed using ANOVA and Duncan's test. Flexural strengths overall decreased (20-40%, P < 0.01) with increasing temperatures except with Conquest C & B. Surprisingly, higher FS values were found in wet conditions than in dry conditions at 25 degrees C. UDMA-based materials much more easily undergo softening in water and by temperature change than do BisGMA- or OCDMA-based materials. Post-cured composites can be significantly affected by exposure to oral environments. Different composition determines the degree of influence.
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592
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Lee JY, Cheon JY, Lee KK, Lee SY, Lee MH. Factors affecting the distribution of hydrocarbon contaminants and hydrogeochemical parameters in a shallow sand aquifer. JOURNAL OF CONTAMINANT HYDROLOGY 2001; 50:139-158. [PMID: 11475158 DOI: 10.1016/s0169-7722(01)00101-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The distributions of hydrocarbon contaminants and hydrogeochemical parameters were investigated in a shallow sand aquifer highly contaminated with petroleum hydrocarbons leaked from solvent storage tanks. For these purposes, a variety of field investigations and studies were performed, which included installation of over 100 groundwater monitoring wells and piezometers at various depths, soil logging and analyses during well and piezometer installation, chemical analysis of groundwater, pump tests, and slug tests. Continuous water level monitoring at three selected wells using automatic data-logger and manual measuring at other wells were also conducted. Based on analyses of the various investigations and tests, a number of factors were identified to explain the distribution of the hydrocarbon contaminants and hydrogeochemical parameters. These factors include indigenous biodegradation, hydrostratigraphy, preliminary pump-and-treat remedy, recharge by rainfall, and subsequent water level fluctuation. The permeable sandy layer, in which the mean water table elevation is maintained, provided a dominant pathway for contaminant transport. The preliminary pump-and-treat action accelerated the movement of the hydrocarbon contaminants and affected the redox evolution pattern. Seasonal recharge by rain, together with indigenous biodegradation, played an important role in the natural attenuation of the petroleum hydrocarbons via mixing/dilution and biodegradation. The water level fluctuations redistributed the hydrocarbon contaminants by partitioning them into the soil and groundwater. The identified factors are not independent but closely inter-correlated.
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593
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Sung SK, Moon YH, Chung JE, Lee SY, Park HG, An G. Characterization of MADS box genes from hot pepper. Mol Cells 2001; 11:352-9. [PMID: 11459226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
The cDNA clone, CanMADS1, was isolated from young flower buds of the hot pepper (Capsicum annuum L.) by screening a cDNA library using the OsMADS1 rice MADS-box gene as a probe. We used a yeast two-hybrid screening method to investigate interaction partners of the protein product of CanMADS1. A MADS-box gene, CanMADS6, was isolated from young flower buds using the region containing the K domain and 15 amino acid residues of the C-terminal region of CanMADS1 as a bait. CanMADS1 and CanMADS6 showed high amino acid sequence similarities to members of the AGL2 subfamily and the SQUA subfamily, respectively. CanMADS1 transcript was expressed in flower buds and fruits, and the transcription signal was the strongest in the stage of the fruit set (2 d after anthesis). CanMADS6 showed the same expression pattern as CanMADS1. CanMADS1 and CanMADS6 were not expressed in leaves. These results suggest that a regulatory role for flower and fruit development of the hot pepper may be accomplished through an interaction of the protein products of the two MADS-box genes, CanMADS1 and CanMADS6.
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594
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Lee SY, Lim JW, Kim YM. Effect of alpha1-acid glycoprotein expressed in cancer cells on malignant characteristics. Mol Cells 2001; 11:341-5. [PMID: 11459224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
The alpha1-acid glycoprotein (AAG) is a prototypical serum acute phase reactant in most mammalian species; it is synthesized mainly in liver parenchymal cells. Recently, we found that mRNAs of AAG were expressed in non-hepatic cancer cells, and the expression levels were regulated by the cytokines--IL-1, IL-6, and TNF-alpha. The functional role of AAG in non-hepatic cancer cells has not yet been established. In order to understand the functional role of the AAG expressed in HT-29 cells, the cancer cells were transfected with cloned cDNA for AAG, or exposed to antisense oligodeoxynucleotide (ODN) for AAG. The colony-forming capacity, invasion, and adhesion to laminin of these transformed cancer cells were measured. Overexpression of AAG by transfection, and inhibition of the AAG expression by antisense ODNs were identified by Western blot as well as nested reverse transcriptase-polymerase chain reaction (nested RT-PCR), respectively. Results showed that the overexpression of AAG by transfection reduced colony-forming capacities, invasion, and adhesion to laminin of the cancer cells; on the other hand, the antisense ODN for AAG elevated colony-forming capacities, invasion, and adhesion to laminin of the cancer cells. These results suggest that AAG, expressed in cancer cells inhibited proliferation, invasion, and metastasis of the cancer cells.
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595
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Chao ST, Suh JH, Raja S, Lee SY, Barnett G. The sensitivity and specificity of FDG PET in distinguishing recurrent brain tumor from radionecrosis in patients treated with stereotactic radiosurgery. Int J Cancer 2001; 96:191-7. [PMID: 11410888 DOI: 10.1002/ijc.1016] [Citation(s) in RCA: 213] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Radiation necrosis and recurrent brain tumor have similar symptoms and are indistinguishable on both magnetic resonance imaging (MRI) and computed tomograph scans. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has been proposed as a diagnostic alternative, particularly when co-registered with MRI. We studied 47 patients with brain tumors treated with stereotactic radiosurgery and followed with FDG PET. For all tumor types, the sensitivity of FDG PET for diagnosing tumor was 75% and the specificity was 81%. For brain metastasis without MRI co-registration, FDG PET had a sensitivity of 65% and a specificity of 80%. For brain metastasis with MRI co-registration, FDG PET had a sensitivity of 86% and specificity of 80%. MRI co-registration appears to improve the sensitivity of FDG PET, making it a useful modality to distinguish between radiation necrosis and recurrent brain metastasis.
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596
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Kim IS, Lee IH, Lee JH, Lee SY. Induction of haptoglobin by all-trans retinoic acid in THP-1 human monocytic cell line. Biochem Biophys Res Commun 2001; 284:738-42. [PMID: 11396964 DOI: 10.1006/bbrc.2001.5041] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Haptoglobin (Hp) is one of the acute-phase proteins and is mainly synthesized in the liver. During our study on the differentiation of leukemia cells, we have found that Hp is synthesized in human monocytic cells by all-trans retinoic acid (ATRA). The synthesis of Hp by ATRA is induced in a dose- and time-dependent manner. Hp cDNA cloned from ATRA-treated THP-1 cells corresponds to the Hp alpha 2(FS)-beta form. Whereas ATRA acted as a strong inducer in THP-1 cells, IL-1 beta, TNF-alpha, IL-6, and LPS had little effect on Hp gene expression in these cells. These findings suggest that THP-1 cells express the Hp gene through a signal pathway different from hepatocytes, and that ATRA is a potent Hp-inducer in these cells.
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597
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Lee SY, Söderhäll K. Characterization of a pattern recognition protein, a masquerade-like protein, in the freshwater crayfish Pacifastacus leniusculus. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:7319-26. [PMID: 11390482 DOI: 10.4049/jimmunol.166.12.7319] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A multifunctional masquerade-like protein has been isolated, purified, and characterized from hemocytes of the freshwater crayfish, Pacifastacus leniusculus. It was isolated by its Escherichia coli binding property, and it binds to formaldehyde-treated Gram-negative bacteria as well as to yeast, Saccharomyces cerevisiae, whereas it does not bind to formaldehyde-fixed Gram-positive bacteria. The intact masquerade (mas)-like protein is present in crayfish hemocytes as a heterodimer composed of two subunits with molecular masses of 134 and 129 kDa. Under reducing conditions the molecular masses of the intact proteins are not changed. After binding to bacteria or yeast cell walls, the mas-like protein is processed by a proteolytic enzyme. The 134 kDa of the processed protein yields four subunits of 65, 47, 33, and 29 kDa, and the 129-kDa protein results in four subunits of 63, 47, 33, and 29 kDa in 10% SDS-PAGE under reducing conditions. The 33-kDa protein could be purified by immunoaffinity chromatography using an Ab to the C-terminal part of the mas-like protein. This subunit of the mas-like protein has cell adhesion activity, whereas the two intact proteins, 134 and 129 kDa, have binding activity to LPSs, glucans, Gram-negative bacteria, and yeast. E. coli coated with the mas-like protein were more rapidly cleared in crayfish than only E. coli, suggesting this protein is an opsonin. Therefore, the cell adhesion and opsonic activities of the mas-like protein suggest that it plays a role as an innate immune protein.
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598
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Lu JJ, Perng CL, Chiueh TS, Lee SY, Chen CH, Chang FY, Wang CC, Chi WM. Detection and typing of vancomycin-resistance genes of enterococci from clinical and nosocomial surveillance specimens by multiplex PCR. Epidemiol Infect 2001; 126:357-63. [PMID: 11467792 PMCID: PMC2869703 DOI: 10.1017/s0950268801005453] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ninety-three clinical isolates of vancomycin-resistant enterococci (VRE) collected from nine hospitals in Taiwan were examined for the presence of vanA, vanB, vanC1, or vanC2/vanC3 genes by a multiplex PCR. Forty-seven of these VRE isolates were vanA positive, 1 contained both vanC1 and vanA, 40 harboured vanB, 2 were vanC1, and 3 were identified to be vanC2/vanC3. Twenty-four vanA isolates were sensitive to teicoplanin and thus did not have a typical VanA phenotype. Five isolates with the VanC phenotype harboured vanB. None of the 40 clinically isolated vancomycin-susceptible E. faecium or E. faecalis and the vancomycin-resistant Leuconostoc and Pediococcus isolates were positive for any of the van genes. While performing nosocomial surveillance, VRE were isolated from 47 of 467 rectal swabs by culture. Compared with the conventional culture method, the sensitivity and specificity of the multiplex PCR for detecting and identifying vancomycin-resistance genes in enterococci directly from culture-positive broth were 97.9% and 100%, respectively. The results suggest that genotypic characterization of vancomycin-resistance is necessary for all clinical VRE isolates and that the multiplex PCR assay can be an alternative method for this purpose.
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599
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Lee SY, Chang SE, Choi JH, Sung KJ, Moon KC, Koh JK. Congenital eccrine angiomatous hamartoma: report of two patients. J Dermatol 2001; 28:338-40. [PMID: 11476116 DOI: 10.1111/j.1346-8138.2001.tb00146.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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600
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Lee KC, Cho YL, Lee SY. Reperfusion pulmonary edema after pulmonary endarterectomy. ACTA ANAESTHESIOLOGICA SINICA 2001; 39:97-101. [PMID: 11475183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Pulmonary artery thromboendarterectomy is a potentially curative procedure in chronic, major vessel thromboembolic pulmonary hypertension. However, persistent pulmonary hypertension and unrelenting reperfusion edema have serious complications, often requiring prolonged mechanical ventilation. A 50-year-old man who was diagnosed with a thromboembolism in both pulmonary arteries underwent a bilateral pulmonary endarterectomy. He received O2-isoflurane-fentanyl anesthesia. When the lungs were reperfused with CPB weaning, massive hemorrhage occurred in the left lung. After the operation, the patient was taken to the intensive care unit. Mechanical ventilation was performed immediately and then both inhaled NO and i.v. furosemide therapies were administered. The patient was discharged from ICU 15 days postoperation.
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