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Yang ZQ, Shin JH, Song HY, Kwon JH, Kim JW, Kim KR, Kim JH. Fluoroscopically guided percutaneous jejunostomy: outcomes in 25 consecutive patients. Clin Radiol 2007; 62:1061-5; discussion 1066-8. [PMID: 17920864 DOI: 10.1016/j.crad.2007.02.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2006] [Revised: 01/17/2007] [Accepted: 02/24/2007] [Indexed: 01/28/2023]
Abstract
AIM To assess the feasibility and safety of fluoroscopically guided percutaneous jejunostomy. MATERIAL AND METHODS Between May 1999 and August 2006 percutaneous jejunostomy was attempted in 25 patients. A 5 F vascular catheter (n=20) or a 7.5 F multifunctional coil catheter (n=5) was used to insufflate the jejunum. The distended jejunum was punctured using a 17 G needle (n=19) or a 21 G Chiba needle (n=6) with the inserted catheter as a target. A 12 or 14 F loop feeding tube was inserted after serial dilations. The technical success, complications, 30-day mortality, and in-dwelling period of the feeding tube placement were evaluated. RESULTS The technical success rate was 92% (23/25). Technical failures (n=2) resulted from the inability to insufflate the jejunum secondary to failure to pass the catheter through a malignant stricture at the oesophagojejunostomy site and thus subsequent puncture of the undistended jejunum failed, or failure to introduce the Neff catheter into the jejunum. Pericatheter leakage with pneumoperitoneum was a complication in three patients (12%) and was treated conservatively. The 30-day mortality was 13% (3/23); however, there was no evidence that these deaths were attributed to the procedure. Except for four patients who were lost to follow-up and two failed cases, 15 of the 19 jejunostomy catheters were removed because of patient death (n=12) or completion of treatment (n=3), with a mean and median in-dwelling period of 231 and 87 days, respectively. CONCLUSIONS Fluoroscopically guided percutaneous jejunostomy is a feasible procedure with a high technical success and a low complication rate. In addition to a 17 G needle, a 21 G needle can safely be used to puncture the jejunum.
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Lee YJ, Sung HW, Choi JG, Lee EK, Jeong OM, Kwon YK, Kwon JH, Song CS, Kimd JH. Effects of Homologous and Heterologous Neuraminidase Vaccines in Chickens Against H5N1 Highly Pathogenic Avian Influenza. Avian Dis 2007; 51:476-8. [PMID: 17494612 DOI: 10.1637/7548-033106r.1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The 2004 Asian H5N1 epizootic outbreak indicates the urgent need for vaccines against highly pathogenic avian influenza (HPAI) virus. The manufacture of inactivated whole-virus vaccines from HPAI viruses by traditional methods is not feasible for safety reasons as well as technical issues. The low pathogenic avian influenza A/wild bird feces/CSM2/02 (H5N3) virus was used as a heterologous neuraminidase vaccine, and HPAI A/CK/Korea/ES/03 (H5N1) virus was used as a homologous neuraminidase vaccine. Protection efficacy of both vaccines was evaluated by clinical signs, mortality rates, and virus shedding from oropharynx and cloaca of vaccinated chickens after challenge with HPAI A/CK/Korea/ES/03 (H5N1) virus. One dose of 128 hemagglutinin (HA) homologous H5N1 vaccine induced 100% protection in mortality and prevented viral shedding completely after lethal dose virus challenge, whereas one dose of 64 HA unit of heterologous H5N3 vaccine only induced 50% protection in mortality, and it did not prevent viral shedding. However, two doses at a 3-wk interval of 64 HA unit of heterologous H5N3 vaccine as well as one dose of 1024 HA unit of heterologous H5N3 vaccine induced 100% survival rate and could prevent viral shedding completely. Furthermore, we could differentiate the sera of infected birds from those of vaccinated birds by indirect immunofluorescent antibody test. These results suggest that heterologous neuraminidase H5N3 vaccine could be a useful tool for the control of H5N1 HPAI epidemic in poultry.
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Choi BR, Kwon JH, Gong SJ, Kwon MS, Cho JH, Kim JH, Oh S, Roh HJ, Kim DE. Expression of glucocorticoid receptor mRNAs in glucocorticoid-resistant nasal polyps. Exp Mol Med 2006; 38:466-73. [PMID: 17079862 DOI: 10.1038/emm.2006.55] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Glucocorticoids (GCs) are the most effective group of medications available to treat inflammation. Although most patients with inflammation respond to GC, a small group of patients exhibit persistent GC-resistance with prolonged inflammation. Previously, it was proposed that the GC-resistance is caused by low amount of human GC receptor (hGRalpha) and/or excessive presence of a GC receptor isoform, hGRbeta that was generated from alternative splicing of the hGR message. We have tested this hypothesis by investigating correlation between the expression pattern of hGR mRNAs in patients with inflammatory nasal polyps and the effectiveness of GC treatment.? We have performed reverse transcription PCR analysis of mRNAs coding each hGRalpha and hGRbeta in nasal tissues.? hGRalpha mRNA was more expressed in patients with nasal polyps than in normal subjects. However, the elevated hGRalphamRNA expression was decreased after GC treatment. Compared with hGRalpha mRNA expression, level of hGRbeta mRNA expression was very low in all groups. In patients, hGRbetamRNA was expressed at a similar level regardless of GC efficacy, indicating that there is no correlation between the GC sensitivity and the expression level of hGRbeta mRNA. Thus, persistent GC-resistance is not associated with low expression of hGRa or over- expression of hGRbeta.
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Kwon JH, Jang HY. Retroanastomotic hernia after gastrojejunostomy: US and CT findings with an emphasis on the whirl sign. ACTA ACUST UNITED AC 2006; 30:656-64. [PMID: 16252151 DOI: 10.1007/s00261-005-0310-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND We reviewed ultrasound (US) and computed tomographic (CT) findings of retroanastomotic hernia and established whether such findings are characteristic of retroanastomotic hernia in patients who have undergone gastrojejunostomy. METHODS During a recent 10-year period, we encountered 13 consecutive cases of retroanastomotic hernia. Of the patients involved, 11 underwent US, 10 underwent CT, and three underwent small bowel followthrough imaging. The US and CT scans were retrospectively reviewed to determine abnormal findings. Surgical proof was available in all cases. RESULTS The efferent loop was herniated through the defect created behind the anastomosis in 10 cases, the efferent and afferent loops in two cases, and the afferent loop in one case. Retroanastomotic hernia was prospectively suggested in 12 of these 13 cases. Among the 10 cases of efferent loop herniation, US and CT signs of retroanastomotic hernia included whirling of mesenteric vessels, jejunal loops, and mesentery in the periumbilical abdomen (10 of 10); mural thickening of herniated bowel loops (six of 10); dilatation of herniated bowel loops (four of 10); decreased peristalsis of herniated bowel loops on US (three of nine); and decreased contrast enhancement of herniated bowel loops on CT (one of seven). In one case, US and CT signs of retroanastomotic hernia of the afferent loop included its dilatation and whirling of a short length of afferent loop behind the anastomosis. In two cases, US and CT signs of retroanastomotic hernia of the afferent and efferent loops included findings of afferent and efferent loop herniations. Three of 13 cases had reversible bowel ischemia, and one had bowel necrosis. CONCLUSION Retroanastomotic hernia is an important condition, and the US and CT findings we have described might suggest its diagnosis.
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Kang HJ, Chawla SP, Jo C, Kwon JH, Byun MW. Studies on the development of functional powder from citrus peel. BIORESOURCE TECHNOLOGY 2006; 97:614-20. [PMID: 16153824 DOI: 10.1016/j.biortech.2005.03.037] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2003] [Revised: 03/21/2005] [Accepted: 03/23/2005] [Indexed: 05/04/2023]
Abstract
The suitability of citrus peels, generated as a by-product of the juice industry, as a source of antioxidants was investigated. Citrus peel powder was prepared by lyophilizing 70% ethanol extract from citrus peels. Extraction was carried out at room temperature (20 degrees C) for 72 h. The extract was subjected to gamma-irradiation treatment (20 kGy). The aqueous solutions of citrus peel powder were examined for color characteristics and antioxidant potential in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, beta-carotene bleaching and nitrite scavenging activities. There were significant changes in Hunter color values due to irradiation. The a*- and b*-values decreased due to radiation treatment. DPPH radical scavenging, beta-carotene bleaching and nitrite scavenging activities were not affected by irradiation treatment. Nitrite scavenging activity was the highest in the extract at pH 1.2 followed by pH 4.2 and 6.0. These functional properties of the aqueous solution were found to be stable in heat treatment. It could significantly improve oxidative stability of lipids in fish meat system. Based on these results there may be opportunities to use citrus peel powder as a functional component in the food processing industry with gamma irradiation treatment improving its color characteristics without adversely influencing the functional properties.
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Yeom IT, Lee KR, Choi YG, Kim HS, Kwon JH, Lee UJ, Lee YH. A pilot study on accelerated sludge degradation by a high-concentration membrane bioreactor coupled with sludge pretreatment. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2005; 52:201-10. [PMID: 16459793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
A new sludge treatment process combining a high MLSS membrane bioreactor with sludge pretreatment techniques was studied in pilot-scale experiments. The membrane bioreactor (MBR) was adopted for high efficiency aerobic digestion. The combination of alkaline-ozone treatment of the mixed liquor in the MBR reactor accelerated the biodegradation process by enhancing biodegradability of the sludge. The hydraulic retention time (HRT) of the reactor was set as 3.1 days and the DO level was 1 mg/L on average. After 5 months of operation, the accumulative total solids reduction was more than 70%. Removal efficiency of volatile solids and non-volatile solids were 76% and 54%, respectively. It was found that a considerable portion of the non-volatile solids was dissolved into ions and then flushed out with the effluent. Also, about 41% and 28% of T-N and T-P in the raw sludge were removed although no biological nutrient removal process was adopted. The experiment was run smoothly without significant membrane fouling, even at the relatively high levels of MLSS concentration (11,000-25,000 mg/L). It is concluded that the newly proposed process can significantly increase the sludge reduction efficiency with much shorter retention times.
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Kwon JH, Park KY, Park JH, Lee SH, Ahn KH. Acidic and hydrogen peroxide treatment of polyaluminum chloride (PACL) sludge from water treatment. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2004; 50:99-105. [PMID: 15581000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The water treatment sludge including coagulants cannot be easily removed by conventional dewatering methods. The possibility of hydrogen peroxide (H2O2) oxidation as a pretreatment to enhance the dewaterability of polyaluminum chloride (PACl) sludge from water works was investigated. H2O2 treatment alone was not effective but H2O2 treatment under acidic condition significantly reduced both the cake water content and specific resistance to filtration (SRF), indicating the enhancement of dewaterability and filterability. The filterability after acid/H2O2 treatment was comparable to polymer conditioning and even more dewatered cake than polymer conditioning was produced. By H202 combined with sulfuric acid (H2SO4), leached iron caused Fenton's reaction, which showed a potential to significantly reduce the amount of solids mass and to produce more compact cake with higher filterability.
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Bifulco A, Mahon J, Kwon JH, Moran PM, Jacobs C. The Vulnerable Attachment Style Questionnaire (VASQ): an interview-based measure of attachment styles that predict depressive disorder. Psychol Med 2003; 33:1099-1110. [PMID: 12946094 DOI: 10.1017/s0033291703008237] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND The Vulnerable Attachment Style Questionnaire (VASQ) was developed to provide a brief self-report tool to assess adult attachment style in relation to depression and validated against an existing investigator-based interview (Attachment Style Interview--ASI). This paper describes the development and scoring of the VASQ and its relationship to poor support and major depression. METHOD Items for the VASQ reflected behaviours, emotions and attitudes relating to attachment relationship style, drawn directly from the ASI. The VASQ was validated against the ASI for 262 community-based subjects. Test-retest was determined on 38 subjects. RESULTS Factor analysis derived two factors, labelled 'insecurity' and 'proximity-seeking'. The VASQ insecurity dimension had highest mean scores for those with interview-based Angry-dismissive and Fearful styles and was significantly correlated with degree of interview-based insecurity. The proximity-seeking VASQ scores had highest mean for those with Enmeshed interview attachment style and was uncorrelated with ASI insecurity. VASQ scores were highly correlated with a well-known self-report measure of insecure attachment (Relationship Questionnaire) and text-retest reliability of the VASQ was satisfactory. The total VASQ score and the insecurity subscale proved highly related to poor support and to depressive disorder. This was not the case for the proximity-seeking subscale. CONCLUSION The VASQ is a brief self-report measure that distinguishes individuals with attachment styles vulnerable for depressive disorder. The use of the measure for screening in research and clinical contexts is discussed.
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Kwon JH, Keates S, Bassani L, Mayer LF, Keates AC. Colonic epithelial cells are a major site of macrophage inflammatory protein 3alpha (MIP-3alpha) production in normal colon and inflammatory bowel disease. Gut 2002; 51:818-26. [PMID: 12427784 PMCID: PMC1773480 DOI: 10.1136/gut.51.6.818] [Citation(s) in RCA: 134] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND AIM Macrophage inflammatory protein 3alpha (MIP-3alpha) is a recently described lymphocyte directed C-C chemokine expressed predominately at extralymphoid sites, including the intestine. The aim of this study was to determine whether colonic epithelial cells produce MIP-3alpha and whether its expression is upregulated in inflammatory bowel disease. METHODS AND RESULTS We found that interleukin 1beta and tumour necrosis factor alpha dose dependently stimulated MIP-3alpha production in Caco-2 and HT-29 intestinal epithelial cells. In cytokine treated Caco-2 and HT-29 cells, a significant increase in MIP-3alpha protein production was observed after three hours and continued for at least 24 hours. Analysis of colonic tissues by quantitative real time polymerase chain reaction and ELISA revealed significantly elevated MIP-3alpha mRNA levels (7.9-fold; p<0.05) and protein levels (8.9-fold; p<0.05) in Crohn's disease compared with controls or ulcerative colitis. MIP-3alpha immunoreactivity in normal colon and inflammatory bowel disease was principally associated with crypt and surface epithelial cells. Moreover, MIP-3alpha protein levels were elevated in primary epithelial cells isolated from patients with inflammatory bowel disease. CONCLUSIONS These findings indicate that increased enterocyte MIP-3alpha production may play an important role in lymphocyte activation and recruitment to the colonic epithelium in Crohn's disease and ulcerative colitis.
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Lee SJ, Kwon JH, Jung CW. Erythropoietin response is inadequate in cancer patients receiving chemotherapy. Int J Hematol 2001; 74:416-20. [PMID: 11794697 DOI: 10.1007/bf02982085] [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: 11/26/2022]
Abstract
The level of serum erythropoietin (EPO) is inappropriately decreased in cancer patients and has been advocated as the main cause of their anemia. In cancer patients, chemotherapy results in a cumulative anemia severe enough to require transfusion. We investigated the changes in serum EPO, hemoglobin, ceruloplasmin, and copper levels in cancer patients receiving chemotherapy. There was a weak but significant inverse relationship between hemoglobin and log[EPO] (r = -0.41; P < .001). Observed/expected serum EPO ratios decline with repeated chemotherapy indicating inadequate EPO response for the degree of anemia. There was no difference in the severity of anemia and in the degree of EPO response between platinum- and non-platinum-treated patients. Ceruloplasmin, copper, and ferritin levels did not change during chemotherapy. Our results suggest that the EPO response is inadequate for the degree of anemia and justifies the use of recombinant human EPO in cancer patients receiving chemotherapy.
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Keates AC, Keates S, Kwon JH, Arseneau KO, Law DJ, Bai L, Merchant JL, Wang TC, Kelly CP. ZBP-89, Sp1, and nuclear factor-kappa B regulate epithelial neutrophil-activating peptide-78 gene expression in Caco-2 human colonic epithelial cells. J Biol Chem 2001; 276:43713-22. [PMID: 11559712 DOI: 10.1074/jbc.m107838200] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We reported previously that human colonic epithelial cells produce the C-X-C chemokine epithelial neutrophil-activating peptide-78 (ENA-78) and that its expression is up-regulated in ulcerative colitis. The aim of this study was to investigate the transcriptional regulation of ENA-78 gene expression in Caco-2 intestinal epithelial cells. Reporter gene transfection and electrophoretic mobility shift assay studies demonstrated that cooperation between two regions of the ENA-78 promoter were required for maximal gene expression in interleukin-1beta-stimulated Caco-2 cells. Binding of activated p50/p65 nuclear factor-kappaB to nucleotides -82 to -91 was essential for interleukin-1beta-dependent gene transcription, whereas binding of constitutively expressed zinc-requiring nuclear factors to nucleotides -125 to -134 (site A) was required for basal gene expression. Scanning mutagenesis of site A demonstrated overlapping binding elements at this locus. One site (CTCCCCC) bound Sp1 and Sp3, and overexpression of Sp1 (but not Sp3) up-regulated basal ENA-78 transcription. Another site (CCCCTCCCCC) was found to bind the zinc finger nuclear factor ZBP-89, and overexpression of this protein significantly repressed ENA-78 reporter gene activity. This study demonstrates that ENA-78 gene expression in Caco-2 intestinal epithelial cells is subject to complex regulation involving the coordinate binding of ZBP-89, Sp1, and nuclear factor-kappaB to the ENA-78 promoter.
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Lee YL, Kwak CH, Kwon JH, Im YS, Choe OS. Observation of a fast-formed absorption grating and a slowly formed phase grating in undeveloped dichromated gelatin. APPLIED OPTICS 2001; 40:3635-3639. [PMID: 18360392 DOI: 10.1364/ao.40.003635] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Real-time diffraction efficiency is measured during hologram formation in undeveloped dichromated gelatin (DCG) film. The main features of real-time diffraction efficiency of undeveloped DCG reveal double peaks with increasing exposure time. Adopting the grating translation technique, we show that the first peak originates from the absorption grating and that the latter is related to the phase grating. To explain such complicated hologram-formation dynamics, we present a phenomenological model for mixed gratings associated with photoinduced refractive-index changes and absorption changes. We have compared the model results with the experimental results, which show good agreement.
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Sohn YD, Lim HJ, Hwang KC, Kwon JH, Park HY, Chung KH, Cho SY, Jang Y. A novel recombinant basic fibroblast growth factor and its secretion. Biochem Biophys Res Commun 2001; 284:931-6. [PMID: 11409882 DOI: 10.1006/bbrc.2001.5076] [Citation(s) in RCA: 18] [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
Basic fibroblast growth factor (FGF-2) is a pleiotropic mitogen which plays an important role in cell growth, differentiation, migration, and survival in different cells and organ systems. Recently, several clinical applications for FGF-2 gene transfer are being evaluated in wound healing and collateral artery development to relieve myocardial and peripheral ischemia due to the ability of FGF-2 to regulate the growth and function of vascular cells. However, FGF-2 lacks a classical hydrophobic secretion signal peptide, the FGF-2 chimeras containing various signal sequences have been explored. In this study, a novel recombinant 4sFGF-2 was constructed by replacing nine residues from the amino-terminus of native FGF-2 (Met1 to Leu9) with eight amino acid residues of signal peptide of FGF-4 (Met1 to Ala8) to better increase the secretion level of FGF-2. When the recombinant FGF-2 gene, cloned into the expression vector with CMV promoter, was expressed in COS-7 cells, the recombinant 4sFGF-2 was highly secreted into the media. The secreted 4sFGF-2 showed the same biological activity as the native FGF-2 in the dose-response effects on DNA synthesis and cell growth of rat aortic smooth muscle cells (RASMCs) and NIH3T3 cells. The 4sFGF-2 also was able to activate MAPK as wild FGF-2 in RASMCs. These results indicate that a novel recombinant 4sFGF-2 may be useful as clinical applicability of angiogenic growth factor gene transfer.
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MESH Headings
- 3T3 Cells
- Animals
- Aorta, Thoracic/cytology
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/physiology
- COS Cells
- Cell Division/drug effects
- Cells, Cultured
- Chlorocebus aethiops
- Cloning, Molecular/methods
- DNA/biosynthesis
- Dose-Response Relationship, Drug
- Fibroblast Growth Factor 2/biosynthesis
- Fibroblast Growth Factor 2/genetics
- Fibroblast Growth Factor 2/pharmacology
- Fibroblast Growth Factor 4
- Fibroblast Growth Factors/genetics
- Fibroblast Growth Factors/pharmacology
- Fibroblasts/metabolism
- Humans
- Mice
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiology
- Polymerase Chain Reaction
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/pharmacology
- Rats
- Rats, Sprague-Dawley
- Recombinant Fusion Proteins/pharmacology
- Recombinant Proteins/biosynthesis
- Recombinant Proteins/pharmacology
- Reverse Transcriptase Polymerase Chain Reaction
- Skin/metabolism
- Transfection/methods
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Vogt Weisenhorn DM, Roback LJ, Kwon JH, Wainer BH. Coupling of cAMP/PKA and MAPK signaling in neuronal cells is dependent on developmental stage. Exp Neurol 2001; 169:44-55. [PMID: 11312557 DOI: 10.1006/exnr.2001.7651] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Neurite formation, an essential feature of neuronal development, is believed to involve participation of the ras-mitogen-activated protein kinase (MAPK) and cAMP-dependent protein kinase A (cAMP/PKA)-mediated signaling pathways. These pathways have been studied extensively in the rat pheochromocytoma cell line PC12, and current hypotheses suggest a single effector mechanism resulting from the convergence of cAMP/PKA and MAPK signaling. However, based on observations using a central neuronal progenitor cell line, AS583-8, there also exists evidence that the two signaling pathways may act independently resulting in neurites with differing dynamic features. In the present study, the upstream components of cAMP/PKA signaling were examined in AS583-8 cells as well as possible interactions with the MAPK pathway. We found that activation of PKA is both necessary and sufficient for the elaboration of rapidly forming processes, typical of the cAMP response. In addition, blockade of the MAPK pathway has no effect on the cAMP response, suggesting that activation of the cAMP/PKA pathway can stimulate neurite formation independent of the MAPK pathway. In order to evaluate which cell line model, PC12 vs AS583-8, best reflects the signaling features of developing central neurons, we examined interactions between cAMP/PKA and MAPK signaling in primary neuronal cultures from several brain regions. In immature cultures (1-day-old), at a point where the initiation of neurite formation is maximal, no interaction was observed. In more mature cultures (7 days old), where synaptic contacts have been established, we found a weak but reproducible activation of MAPK following stimulation of the cAMP/PKA pathway. These results suggest that cAMP/PKA and MAPK signaling act independently at the initiation of neuritogenesis but become coupled during later stages of neuronal development. Therefore, the interaction of the two pathways may be cell stage (younger vs older) specific and may participate in cellular functions that take place after initial neurite formation.
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Abstract
Mechanical forces regulate the structure and function of many tissues in vivo; recent results indicate that the mechanical environment can decisively influence the development of engineered tissues cultured in vitro. To investigate the effects of the hydrodynamic environment on tissue-engineered cartilage, primary bovine calf chondrocytes were seeded on fibrous polyglycolic acid meshes and cultured in spinner flasks either statically or at one of nine different turbulent mixing intensities. In medium from unmixed flasks, CO(2) accumulated and O(2) was depleted, whereas in medium from mixed flasks the concentrations of both gases approached their equilibrium values. Relative to constructs exposed to nonmixed conditions, constructs exposed to mixing contained higher fractions of collagen, synthesized and released more GAG, but contained lower fractions of GAG. Across the wide range of mixing intensities investigated, the presence or absence of mixing, but not the intensity of the mixing, was the primary determinant of the GAG and collagen content in the constructs. The all-or-none nature of these responses may provide insight into the mechanism(s) by which engineered cartilage perceives changes in its hydrodynamic environment and responds by modifying extracellular matrix production and release. 2001 John Wiley & Sons, Inc.
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Kwon JH, Lee YM, An CS. CDNA cloning of chloroplast omega-3 fatty acid desaturase from Capsicum annuum and its expression upon wounding. Mol Cells 2000; 10:493-7. [PMID: 11101138 DOI: 10.1007/s10059-000-0493-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
A clone for a plastid omega-3 fatty acid desaturase (FAD) was isolated from a leaf cDNA library of hot pepper (Capsicum annuum L.). The nucleotide sequence of a 1,317 bp open reading frame in the CachFAD showed 80.9% homology with that of tobacco plant. It codes for a polypeptide of 438 amino acids with molecular mass of 50.5 kDa and a pI of 8.14. The CachFAD had a putative transit peptide for targeting the chloroplast. Genomic Southern hybridization indicated that it exists as small gene family. Northern hybridization revealed that its mRNA was present in leaves, but not in roots. Transcript levels in the leaves upon wounding increased rapidly to reach the first peak between 1-3 h, decreased thereafter and slightly increased at 24 h after wounding. The levels of linolenic acid (18:3) in wounded leaves also reached the first peak at 6 h, decreased thereafter and reached the second peak at 18 h. These results indicated that wounding not only enhanced the accumulation of the CachFAD mRNA but also increased the conversion of linoleic acid (18:2) to linolenic acid (18:3) in leaf lipids of hot pepper.
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Abstract
The migration of surgical wires and pins placed for repair of orthopedic injury is well recognized. Such migration usually follows a retrograde path and the wires protrude near their entry point into the native bone. Occasionally, the migration occurs in an antegrade manner and produces injury. We describe a case where three Steinmann pins placed for fixation of a humeral neck fracture migrated, one slipping backwards towards the humeral entry point and two pins migrating into the thorax.
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Kwon JH, Chun JY, Lee HS, Cheon CI, Song ES, Min KH, Lee MS. Cloning of the histidine biosynthetic genes from Corynebacterium glutamicum: organization and analysis of the hisG and hisE genes. Can J Microbiol 2000; 46:848-55. [PMID: 11006846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The physically linked hisG and hisE genes, encoding for ATP-phosphoribosyltransferase and phosphoribosyl-ATP-pyrophosphohydrolase were isolated from the Corynebacterium glutamicum gene library by complementation of Escherichia coli histidine auxotrophs. They are two of the nine genes that participate in the histidine biosynthetic pathway. Molecular genetics and sequencing analysis of the cloned 9-kb insert DNA showed that it carries the hisG and hisE genes. In combining this result with our previous report, we propose that all histidine biosynthetic genes are separated on the genome by three unlinked loci. The coding regions of the hisG and hisE genes are 279 and 87 amino acids in length with a predicted size of about 30 and 10 kDa, respectively. Computer analysis revealed that the amino acid sequences of the hisG and hisE gene products were similar to those of other bacteria.
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Kim JK, Kim MS, Bae JH, Kwon JH, Lee HB, Jeong SH. Gap measurement by position-sensitive detectors. APPLIED OPTICS 2000; 39:2584-2591. [PMID: 18345175 DOI: 10.1364/ao.39.002584] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A system for measuring the gap in a proximity exposure tool of a plasma display panel (PDP) is developed that uses single or dual position-sensitive detectors (PSD's). The resolution of the gap distance is 0.5 mum, with a capture range of 500 mum. Signal processing is simple and fast and easy because analogous PSD's are used as the position sensors. One PSD is used to detect the position of the reference beam, which is reflected from the upper surface of the gap; the other PSD is used to detect the position of the signal beam, which is reflected from the lower surface of the gap. A charge-coupled-device sensor is also employed to monitor the reflected beams and the region of measurement. In the gap-measurement system that uses a single PSD, first the reference beam is incident upon the PSD and then the signal beam is incident upon the same PSD. Then the separation between the two beams is calculated from the position of the reference beam and from the average beam position.
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Kim YH, Chang SH, Kwon JH, Rhee SS. HIV-1 Nef plays an essential role in two independent processes in CD4 down-regulation: dissociation of the CD4-p56(lck) complex and targeting of CD4 to lysosomes. Virology 1999; 257:208-19. [PMID: 10208934 DOI: 10.1006/viro.1999.9642] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Human immunodeficiency virus type 1 (HIV-1) Nef down-regulates CD4 by triggering rapid endocytosis of cell surface CD4. To better understand how Nef induces CD4 down-regulation, we generated a series of Nef mutants with small in-frame deletions in the coding region. Three classes of mutants were obtained. The first class produces neither CD4 down-regulation nor dissociation of the CD4-p56(lck) complex. The second class induces CD4 down-regulation in cells lacking p56(lck) expression, but not in cells with p56(lck);these mutants fail to dissociate CD4 from p56lck. These results show that Nef-mediated CD4 dissociation from p56(lck) is important for CD4 down-regulation. The third class of mutants is able to dissociate the CD4-p56(lck) complex but fails to down-regulate surface CD4; internalized CD4 molecules are recycled back to the cell surface. This result suggests that Nef diverts the CD4 recycling pathway to a degradative pathway. We also demonstrate that Nef associates with phosphatidylinositol-3-kinase (PI3K) activity, which is known to be involved in several aspects of membrane trafficking. However, Nef mutants that cause internalized CD4 to be recycled do not associate with PI3K activity; thus Nef-associated PI3K activity might be involved in the latter process of targeting CD4 to a degradative pathway. We conclude that HIV-1 Nef plays a critical role in multiple processes in CD4 down-regulation: (i) disrupting the CD4-p56(lck) complex on the cell surface to allow CD4 internalization and (ii) diverting the internalized CD4 to a lysosomal pathway for its degradation, likely through a PI3K activity.
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Shimizu A, Sasaki T, Kwon JH, Odaka A, Satoh T, Sakurai N, Sakurai T, Yamaguchi S, Samejima T. Site-directed mutagenesis of a possible type 1 copper ligand of bilirubin oxidase; a Met467Gln mutant shows stellacyanin-like properties. J Biochem 1999; 125:662-8. [PMID: 10101277 DOI: 10.1093/oxfordjournals.jbchem.a022334] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In our previous paper, we reported a mutant of recombinant Myrothecium verrucaria bilirubin oxidase, in which the Met467 residue was replaced by Gly [Shimizu, A. et al. (1999) Biochemistry 38, 3034-3042]. This mutant displayed a remarkable reduction in enzymatic activity and an evident decrease in the intensity of the absorption band around 600 nm (type 1 charge transfer transition). In this study, we report the preparation of three Met467 mutants (Met467Gln, Met467His, and Met467Arg) and characterize their enzymatic activities, midpoint potentials, and absorption and ESR spectra. Met467His and Met467Arg show no enzymatic activity and a great reduction in the intensity of the absorption band around 600 nm. Furthermore, their ESR spectra show no type 1 copper signal, but only a type 2 copper signal; however, oxidation by ferricyanide caused the type 1 copper signal to appear. On the other hand, Met467Gln as expressed shows both type 1 and type 2 copper signals in its ESR spectrum, the type 1 copper atom parameters being very different from usual blue copper proteins but very similar to those of stellacyanin. The enzymatic activity of the Met467Gln mutant for bilirubin is quite low (0.3%), but the activity for potassium ferrocyanide is similar (130%) to that of the wild type enzyme. These results indicate that Met467 is important for characterizing the features of the type 1 copper of bilirubin oxidase.
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Shimizu A, Kwon JH, Sasaki T, Satoh T, Sakurai N, Sakurai T, Yamaguchi S, Samejima T. Myrothecium verrucaria bilirubin oxidase and its mutants for potential copper ligands. Biochemistry 1999; 38:3034-42. [PMID: 10074356 DOI: 10.1021/bi9819531] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bilirubin oxidase (EC:1.3.3.5) purified from a culture medium of Myrothecium verrucaria MT-1 (authentic enzyme) catalyzes the oxidation of bilirubin to biliverdin in vitro and recombinant enzyme (wild type) was obtained by using an overexpression system of the bilirubin oxidase gene with Aspergillus oryzae harboring an expression vector. The absorption and ESR spectra showed that both bilirubin oxidases are multicopper oxidases containing type 1, type 2, and type 3 coppers similar to laccase, ascorbate oxidase, and ceruloplasmin. Site-directed mutagenesis has been performed for the possible ligands of each type of copper. In some mutants, Cys457 --> Val, Ala, His94 --> Val, and His134.136 --> Val, type 1 and type 2 copper centers were perturbed completely and the enzyme activity was completely lost. Differing from the holoenzyme, these mutants showed type 3 copper signals. However, the optical and magnetic properties characteristic of type 1 copper were retained even by mutating one of the type 1 copper ligands, i.e., a mutant, Met467 --> Gly, showed a weak but apparent enzyme activity. A double mutant His456.458 --> Val had only type 1 Cu, showing a blue band at 600 nm (epsilon = 1.6 x 10(3)) and an ESR signal with very narrow hyperfine splitting (A parallel = 7.2 x 10(-)3 cm-1). Since the type 2 and type 3 coppers are not present, the mutant did not show enzyme activity. These results strongly imply that the peculiar sequence in bilirubin oxidase, His456-Cys457-His458, forms an intramolecular electron-transfer pathway between the type 1 copper site and the trinuclear center composed of the type 2 and type 3 copper sites.
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Bang YJ, Kwon JH, Kang SH, Kim JW, Yang YC. Increased MAPK activity and MKP-1 overexpression in human gastric adenocarcinoma. Biochem Biophys Res Commun 1998; 250:43-7. [PMID: 9735328 DOI: 10.1006/bbrc.1998.9256] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mitogen-activated protein kinase (MAPK) has been known to play a critical role in the regulation of the carcinogenesis in human cancers. In an effort to understand the functional role of the MAPK in the carcinogenesis of human gastric tissues, we examined the changes of MAPK levels in human gastric adenocarcinoma. We found that increased MAPK activity was accompanied by overexpression of mitogen-activated protein kinase phosphatase-1 (MKP-1), suggesting that signaling pathways leading to the activation of MAPK and the induction of MKP-1 expression are associated with carcinogenesis of human gastric adenocarcinoma.
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Kwon JH, Vogt Weisenhorn DM, Downen M, Ruan K, Roback L, Joshi H, Wainer BH. Beta-adrenergic and fibroblast growth factor receptors induce neuronal process outgrowth through different mechanisms. Eur J Neurosci 1998; 10:2776-89. [PMID: 9758148 DOI: 10.1111/j.1460-9568.1998.00315.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The mechanisms that initiate and direct neuronal process formation remain poorly understood. We have recently described a neuronal progenitor cell line, AS583-8.E4.22 (AS583-8) which undergoes neurite formation in response to beta2-adrenergic and basic fibroblast growth factor (bFGF) receptor activation [Kwon, J.H. et al., (1996) Eur. J. Neurosci., 8, 2042-2055]. In the present study, a comparison of these responses revealed that isoproterenol (ISO), a beta-adrenergic receptor agonist, induces multiple, highly branched processes within 30 min while bFGF induces fewer, unbranched processes within 24 h. In contrast to the ISO response, bFGF induces mitogen-activated protein kinase activation and c-fos expression in the cell line and results in neurite outgrowth that is dependent on new mRNA and protein synthesis. Two-dimensional isoelectric focusing-sodium dodecyl sulphate-polyacrylamide gel electrophoresis of cytoskeletal preparations revealed different patterns following ISO vs. bFGF exposure suggesting selective changes in protein expression and/or post-translational modifications. Immunoblot analysis of these preparations for beta-tubulin, tyrosinated alpha-tubulin and acetylated alpha-tubulin also revealed different patterns following each type of treatment. Follow-up confocal microscopy revealed that following ISO, the distribution of tyrosinated tubulin extends to the distal ends of processes whereas acetylated alpha-tubulin is diminished within distal ends. This pattern has been reported to be associated with enhanced microtubule dynamics, a state in which process outgrowth is facilitated. In contrast, following bFGF treatment the distributions of tyrosinated and acetylated alpha-tubulin were identical, a state associated with a diminution of microtubule dynamics. These results, a different time course of neurite formation, dependency on new gene expression and differential expression and cellular distribution of major cytoskeleton proteins suggest that neurite outgrowth induced by ISO vs. bFGF is mediated by two distinct intracellular effector mechanisms in AS583-8 cells. In addition, studies, using the differential distribution of post-translational modified alpha-tubulins in neurites of primary neuronal cultures as marker for the two distinct processes of neurite formation suggest, that similar mechanisms are present in vivo. Therefore, the AS583-8 cell line provides a useful model to study these signalling mechanisms that couple neurotransmitter and growth factor receptor activation to the cytoskeletal changes that mediate neurite formation.
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Jung SI, Han MS, Kwon JH, Cheon CI, Min KH, Lee MS. Cloning of the histidine biosynthetic genes of Corynebacterium glutamicum: organization and sequencing analysis of the hisA, impA, and hisF gene cluster. Biochem Biophys Res Commun 1998; 247:741-5. [PMID: 9647764 DOI: 10.1006/bbrc.1998.8850] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The hisA and hisF genes of Corynebacterium glutamicum were cloned by transforming histidine auxotrophic Escherichia coli with the genomic DNA library. They are two of the eight genes that participate in the histidine biosynthetic pathway. Cloned DNA fragments containing the genes can also complement hisH and hisI auxotrophs of Escherichia coli, suggesting that the four genes are clustered in the genome. We determined the nucleotide sequences of the minimal fragment containing the hisA and hisF genes, which are separated by the impA gene. The coding regions of the hisA and hisF genes are 245 and 257 amino acids in length with a predicted size of about 26 and 27 kDa, respectively. These are in good agreement with the sizes of proteins expressed in E. coli. A high similarity was observed in comparison of nucleotide sequences of each protein between C. glutamicum and other species, as well as those between hisA and hisF genes of C. glutamicum.
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