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Keerthana SP, Yuvakkumar R, Ravi G, Hong SI, Al-Sehemi AG, Velauthapillai D. Fabrication of Ce doped TiO 2 for efficient organic pollutants removal from wastewater. Chemosphere 2022; 293:133540. [PMID: 34999098 DOI: 10.1016/j.chemosphere.2022.133540] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 12/23/2021] [Accepted: 01/03/2022] [Indexed: 06/14/2023]
Abstract
Pristine and Ce doped TiO2 nanoparticles were fabricated for toxic pollutants removal from wastewater. Pristine, 2% Ce and 4% Ce doped TiO2 photocatalysts were produced via hydrothermal route. 4% Ce doped TiO2 exhibited 2.41 eV bandgap which is smaller than pure TiO2. The morphology was also investigated and it was established that doping of Ce ions enhanced the surface roughness and reduced the particle size. The surface area was characterized through BET analysis and 4% Ce-TiO2 possess higher surface with large pore diameter which helped the photocatalytic activity. The prepared photocatalysts were investigated on reduction of pollutants from wastewater under visible light. Higher efficiency was obtained for 4% Ce-TiO2 photocatalyst for both model pollutants. The "k" value possessed was also higher for the doped TiO2 catalyst. These analysis reports the optimum level of ceria doping to enhance morphology, surface area and it increased activity than bare TiO2. 4% Ce-TiO2 will be the potential candidate for efficient wastewater management. The 4% Ce doped TiO2 photocatalyst provided 77% and 88% on reducing MB and RhB dyes. The dopant has developed higher surface area, morphology and good recombination rate which reduced the toxic pollutants and changed the wastewater to reuse.
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Affiliation(s)
- S P Keerthana
- Department of Physics, Alagappa University, Karaikudi, 630 003, Tamil Nadu, India
| | - R Yuvakkumar
- Department of Physics, Alagappa University, Karaikudi, 630 003, Tamil Nadu, India.
| | - G Ravi
- Department of Physics, Alagappa University, Karaikudi, 630 003, Tamil Nadu, India.
| | - S I Hong
- Department of Materials Science and Engineering, Chungnam National University, Daejeon, South Korea
| | | | - Dhayalan Velauthapillai
- Faculty of Engineering and Science, Western Norway University of Applied Sciences, Bergen, 5063, Norway
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Keerthana SP, Yuvakkumar R, Senthil Kumar P, Ravi G, Hong SI, Velauthapillai D. Investigation of PEG directed Sb 2WO 6 for dyes removal from wastewater. Chemosphere 2022; 291:132677. [PMID: 34715096 DOI: 10.1016/j.chemosphere.2021.132677] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 09/27/2021] [Accepted: 10/23/2021] [Indexed: 06/13/2023]
Abstract
Pristine and polyethylene glycol assisted antimony tungstate (Sb2WO6) was developed via hydrothermal route. The pristine and surfactant assisted Sb2WO6 were further exemplified to reveal the properties of the samples. The bandgap calculated for Sb2WO6, 5 ml PEG- Sb2WO6, 10 ml PEG- Sb2WO6 was 2.78 eV, 2.66 eV and 2.21 eV. The 10 ml PEG assisted sample exhibited narrow bandgap. The Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed metal vibrations and stretching of the water molecules adsorbed. The Raman spectra showed the vibrational modes present in Sb2WO6. The morphology was analyzed employing transmission electron microscope (TEM) for all samples. Pristine Sb2WO6 showed growth of nanorods with higher dimensions with high agglomeration. 5 ml PEG- Sb2WO6 showed the growth of nanorods with lesser agglomeration. 10 ml PEG assisted Sb2WO6 exhibited distinct growth of nanorods with no agglomeration on the surface. The elemental composition was examined employing X-ray Photoelectron Spectroscopy. Prepared product photocatalytic behaviour was tested employing Rhodamine B dye degrading. Different catalyst loading were investigated for degrading the toxic pollutants. 0.2 g 10 ml PEG-Sb2WO6 showed 81% efficiency on degrading the toxic pollutant from wastewater. The OH radicals are accountable for photocatalytic behaviour of prepared photocatalyst. The 10 ml PEG-Sb2WO6 has the good reusability behavior and stable properties after three cycles. The prepared 10 ml PEG- Sb2WO6 photocatalyst will be the potential candidate for the remediation of the water treatment.
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Affiliation(s)
- S P Keerthana
- Department of Physics, Alagappa University, Karaikudi, 630 003, Tamil Nadu, India
| | - R Yuvakkumar
- Department of Physics, Alagappa University, Karaikudi, 630 003, Tamil Nadu, India.
| | - P Senthil Kumar
- Department of Chemical Engineering, Sri Sivasubramaniya Nadar College of Engineering, Chennai, 603110, India; Centre of Excellence in Water Research (CEWAR), Sri Sivasubramaniya Nadar College of Engineering, Chennai, 603110, India.
| | - G Ravi
- Department of Physics, Alagappa University, Karaikudi, 630 003, Tamil Nadu, India
| | - S I Hong
- Department of Materials Science and Engineering, Chungnam National University, Daejeon, South Korea
| | - Dhayalan Velauthapillai
- Faculty of Engineering and Science, Western Norway University of Applied Sciences, Bergen, 5063, Norway
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Keerthana SP, Yuvakkumar R, Senthil Kumar P, Ravi G, Hong SI, Velauthapillai D. Investigation of pure and g-C 3N 4 loaded CdWO 4 photocatalytic activity on reducing toxic pollutants. Chemosphere 2022; 291:133090. [PMID: 34856234 DOI: 10.1016/j.chemosphere.2021.133090] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 10/22/2021] [Accepted: 11/25/2021] [Indexed: 05/07/2023]
Abstract
A facile synthesis of pristine and g-C3N4 loaded CdWO4 (Cadmium Tungstate) were reported and analyzed the effect of pollutants removal in wastewater. The samples were characterized and the morphology of the pristine sample showed the nanostructures with high cluster of layer formed. While adding PEG (Polyethylene glycol), the surface has exhibited less agglomeration and in g-C3N4 added sample the agglomeration was intensely reduced and nanostructures have been clearly found. Photocatalytic performance on cationic dye was investigated under visible light. The efficiency calculated for g-C3N4- CdWO4 sample was 85% for MB. The C/C0 plot gives better degradation. The kinetic study revealed pseudo first order reaction. The g-C3N4-CdWO4 sample exhibited higher "k" value which proved best efficiency on removing the pollutant. g-C3N4-CdWO4 sample will make better reduction on toxic pollutants and be a good candidate in futuristic applications. By carbon based derivates inclusion with photo active materials, the morphology and surface area was greatly improved and it enhances activity of host material and it will be the promising material for industrial applications.
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Affiliation(s)
- S P Keerthana
- Department of Physics, Alagappa University, Karaikudi, 630 003, Tamil Nadu, India
| | - R Yuvakkumar
- Department of Physics, Alagappa University, Karaikudi, 630 003, Tamil Nadu, India.
| | - P Senthil Kumar
- Department of Chemical Engineering, Sri Sivasubramaniya Nadar College of Engineering, Chennai, 603110, India; Centre of Excellence in Water Research (CEWAR), Sri Sivasubramaniya Nadar College of Engineering, Chennai, 603110, India.
| | - G Ravi
- Department of Physics, Alagappa University, Karaikudi, 630 003, Tamil Nadu, India
| | - S I Hong
- Department of Materials Science and Engineering, Chungnam National University, Daejeon, South Korea
| | - Dhayalan Velauthapillai
- Faculty of Engineering and Science, Western Norway University of Applied Sciences, Bergen, 5063, Norway
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Park KH, Jung M, Kim DY, Lee YM, Lee MS, Ryu BH, Hong SI, Hong KW, Bae IG, Cho OH. Effects of subinhibitory concentrations of chlorhexidine and mupirocin on biofilm formation in clinical meticillin-resistant Staphylococcus aureus. J Hosp Infect 2020; 106:295-302. [PMID: 32679053 DOI: 10.1016/j.jhin.2020.07.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 07/06/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND The effects of subinhibitory concentrations (sub-MICs) of antibacterial agents on the biofilm-forming ability of Staphylococcus aureus require further study. AIM To investigate the effects of sub-MICs of chlorhexidine and mupirocin on biofilm formation in clinical meticillin-resistant Staphylococcus aureus (MRSA) isolates. METHODS MRSA isolates were collected from patients with bloodstream infections at a tertiary care hospital. The basal level of biofilm formation and biofilm induction by sub-MICs of chlorhexidine and mupirocin were evaluated by measuring biofilm mass stained with Crystal Violet. FINDINGS Of the 112 MRSA isolates tested, 63 (56.3%) and 44 (39.3%) belonged to sequence type (ST)5 and ST72 lineages, respectively, which are the predominant healthcare- and community-associated clones in South Korea. ST5 isolates were more likely to have chlorhexidine MIC ≥4 (73.0% vs 29.5%), resistance to mupirocin (23.8% vs 0%), agr dysfunction (73.0% vs 9.1%), and qacA/B gene (58.7% vs 2.3%) compared to ST72 isolates. The basal level of biofilm formation ability was frequently stronger in ST72 isolates compared to ST5 isolates (77.3% vs 12.7%). Sub-MICs of chlorhexidine and mupirocin promoted biofilm formation in 56.3% and 53.6%, respectively, of all isolates. Biofilm induction was more prevalent in ST5 isolates (85.7% for chlorhexidine, 69.8% for mupirocin) than in ST72 isolates (15.9% for chlorhexidine, 27.3% for mupirocin). CONCLUSION Sub-MICs of chlorhexidine and mupirocin promoted biofilm formation in half of the clinical MRSA isolates. Our results suggest that ST5 MRSA biofilm can be induced together with some other bacterial virulent factors following exposure to chlorhexidine, which might confer a survival advantage to this clone in the healthcare environment.
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Affiliation(s)
- K-H Park
- Division of Infectious Diseases, Department of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - M Jung
- Division of Infectious Diseases, Department of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - D Y Kim
- Division of Infectious Diseases, Department of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - Y-M Lee
- Division of Infectious Diseases, Department of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - M S Lee
- Division of Infectious Diseases, Department of Internal Medicine, Kyung Hee University Hospital, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - B-H Ryu
- Department of Internal Medicine, Gyeongsang National University Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Republic of Korea
| | - S I Hong
- Department of Internal Medicine, Gyeongsang National University Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Republic of Korea
| | - K-W Hong
- Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University College of Medicine, Jinju, Republic of Korea
| | - I-G Bae
- Department of Internal Medicine, Gyeongsang National University Hospital, Gyeongsang National University College of Medicine, Jinju, Republic of Korea; Gyeongsang Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, Republic of Korea
| | - O-H Cho
- Department of Internal Medicine, Gyeongsang National University Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Republic of Korea; Gyeongsang Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju, Republic of Korea.
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Maheswari RU, Yuvakkumar R, Ravi G, Hong SI. Organic Datura metel Leaf Extract Mediated Inorganic Rare Earth La₂O₃ Nanocrystals Formation. J Nanosci Nanotechnol 2019; 19:4033-4038. [PMID: 30764966 DOI: 10.1166/jnn.2019.16303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Development of sustainable synthesis of La₂O₃ nanocrystals formation employing Datura metel leaf extract was explored. The obtained nanocrystals were analyzed employing XRD, Raman, PL, FTIR, XPS and TEM characterizations. With increasing incubation and aging, the transformation of La(OH)₃ to LaOOH and metal ellagate complex formation to La₂O₃ nanocrystals formation was observed. The obtained XRD results clearly revealed the transformation of lanthanum hydroxide to lanthanum oxide hydroxide and then to lanthanum oxide nanocrystals formation with 1, 4 and days. The influence of incubation and aging on La₂O₃ nanocrystals formation was discussed. Datura metel leaf extract product mixture over a period of incubation formed pure hexagonal lanthanum oxide nanocrystals.
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Affiliation(s)
- R Uma Maheswari
- Department of Biochemistry, Madurai Medical College, Government Rajaji Hospital, Madurai 625020, Tamil Nadu, India
| | - R Yuvakkumar
- Department of Nanomaterials Engineering, Chungnam National University, Daejeon, 305-764, South Korea
| | - G Ravi
- Nanomaterials Laboratory, Department of Physics, Alagappa University, Karaikudi 630003, Tamil Nadu, India
| | - S I Hong
- Department of Nanomaterials Engineering, Chungnam National University, Daejeon, 305-764, South Korea
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Won YY, Park JS, Choi SJ, Hong SI. A novel flexible drill device enabling arthroscopic transosseous repair of Bankart lesions. Orthop Traumatol Surg Res 2017; 103:499-504. [PMID: 28359839 DOI: 10.1016/j.otsr.2017.02.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 01/27/2017] [Accepted: 02/22/2017] [Indexed: 02/02/2023]
Abstract
UNLABELLED We have developed a flexible drill device that makes arthroscopic transosseous repair possible, and report preliminary results. Twelve patients with post-traumatic anterior inferior glenohumeral instability were selected. SURGICAL TECHNIQUE the flexible drill device is inserted into the shoulder joint through the posterior portal and the guide pipe unit is placed 5mm posterior to the margin of the anterior glenoid rim. The flexible drill is driven through the glenoid with the power drill, creating a hole in the glenoid. A non-absorbable suture is passed through the hole and a sliding knot tying is performed over the capsule and labrum after completing stitches with the suture hook loaded. The same procedures are repeated in the 2, 3 and 4 o'clock positions of the glenoid. There was no recurrence of dislocation at the mean follow-up period of 52.3 months. The mean Rowe score was 89.5.
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Affiliation(s)
- Y-Y Won
- Department of Orthopedic Surgery, Ajou University School of Medicine, Suwon, Republic of Korea
| | - J S Park
- Hallym university, Kangnam Sacred Heart Hospital, 07441 Seoul, Republic of Korea.
| | - S J Choi
- Hallym university, Kangnam Sacred Heart Hospital, 07441 Seoul, Republic of Korea
| | - S I Hong
- Hallym university, Kangnam Sacred Heart Hospital, 07441 Seoul, Republic of Korea
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Yuvakkumar R, Hong SI. Structural and toxic effect investigation of vanadium pentoxide. Mater Sci Eng C Mater Biol Appl 2016; 65:419-24. [PMID: 27157769 DOI: 10.1016/j.msec.2016.04.066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Revised: 03/17/2016] [Accepted: 04/18/2016] [Indexed: 02/06/2023]
Abstract
A facile inorganic complex synthesis route has been developed to synthesis V2O5 nanostructures. The effects of varying incubation time on the crystallinity and morphology of the V2O5 phase has been investigated. The obtained XRD result clearly revealed the pure orthorhombic V2O5 crystalline phase. Raman antiphase bridging VO and chaining VO stretching modes peaks at 686 and 521cm(-1) attributed orthorhombic V2O5 characteristics. The V2p3/2 peak at the binding energies of 517eV and V2p1/2 peak at 524eV assigned to V(5+) oxidation state. Bioinspired V2O5 nanostructures as a biocompatible material for anticancer agents show excellent cytotoxicity at higher V2O5 concentration.
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Affiliation(s)
- R Yuvakkumar
- Nanomaterials Laboratory, Department of Physics, Alagappa University, Karaikudi 630 004, Tamil Nadu, India; Department of Nanomaterials Engineering, Chungnam National University, Daejeon 305-764, South Korea.
| | - S I Hong
- Department of Nanomaterials Engineering, Chungnam National University, Daejeon 305-764, South Korea.
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8
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Yun JH, Sung H, Kim T, Hong SI, Chong YP, Kim SH, Choi SH, Kim YS, Woo JH, Lee SO. Comparison of the clinical characteristics of Mycobacterium tuberculosis and nontuberculous mycobacteria patients with joint involvement. Infection 2015; 43:207-9. [PMID: 25623639 DOI: 10.1007/s15010-015-0731-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 01/14/2015] [Indexed: 01/15/2023]
Abstract
Nontuberculous mycobacteria (NTM) joint involvement is rare. However, the incidence of NTM disease is increasing and it is difficult to distinguish NTM from Mycobacterium tuberculosis (MTB). Here, the clinical characteristics of NTM joint involvement were compared with those of MTB. Distal joint involvement and precipitating factors were significantly more frequent for NTM joint infections. Because pathologic findings of NTM and MTB were similar, microbiological investigations are needed.
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Affiliation(s)
- J H Yun
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 138-736, Republic of Korea
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Yuvakkumar R, Suresh J, Nathanael AJ, Sundrarajan M, Hong SI. Novel green synthetic strategy to prepare ZnO nanocrystals using rambutan (Nephelium lappaceum L.) peel extract and its antibacterial applications. Mater Sci Eng C Mater Biol Appl 2014; 41:17-27. [PMID: 24907732 DOI: 10.1016/j.matlet.2014.04.112] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 03/11/2014] [Accepted: 04/07/2014] [Indexed: 05/26/2023]
Abstract
In the present investigation, we report a sustainable novel green synthetic strategy to synthesis zinc oxide nanocrystals. This is the first report on sustainable biosynthesis of zinc oxide nanocrystals employing Nephelium lappaceum L., peel extract as a natural ligation agent. Green synthesis of zinc oxide nanocrystals was carried out via zinc-ellagate complex formation using rambutan peel wastes. The successful formation of zinc oxide nanocrystals was confirmed employing standard characterisation studies. A possible mechanism for the formation of ZnO nanocrystals with rambutan peel extract was also proposed. The prepared ZnO nanocrystals were coated on the cotton fabric and their antibacterial activity were analyzed. ZnO nanocrystals coated cotton showed good antibacterial activity towards Escherichia coli (E. coli), gram negative bacteria and Staphylococcus aureus (S. aureus), gram positive bacteria.
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Affiliation(s)
- R Yuvakkumar
- Department of Nanomaterials Engineering, Chungnam National University, Daejeon, 305-764, South Korea
| | - J Suresh
- Advanced Green Chemistry Lab, Department of Industrial Chemistry, School of Chemistry, Alagappa University, Karaikudi - 630 003, Tamil Nadu, India
| | - A Joseph Nathanael
- Department of Nano, Medical and Polymer Materials, Yeungnam University, Gyeongsan 712-749, South Korea
| | - M Sundrarajan
- Advanced Green Chemistry Lab, Department of Industrial Chemistry, School of Chemistry, Alagappa University, Karaikudi - 630 003, Tamil Nadu, India.
| | - S I Hong
- Department of Nanomaterials Engineering, Chungnam National University, Daejeon, 305-764, South Korea.
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Lee EJ, Kim YH, Lee NH, Hong SI, Yamamoto K, Kim YJ. The role of sarcoplasmic protein in hydrostatic pressure-induced myofibrillar protein denaturation. Meat Sci 2011; 87:219-22. [DOI: 10.1016/j.meatsci.2010.10.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Revised: 08/12/2010] [Accepted: 10/14/2010] [Indexed: 10/18/2022]
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Kang JS, Awate SV, Lee YJ, Kim SJ, Park MJ, Lee SD, Hong SI, Moon DJ. Nano-sized cobalt based Fischer-Tropsch catalysts for gas-to-liquid process applications. J Nanosci Nanotechnol 2010; 10:3700-3704. [PMID: 20359031 DOI: 10.1166/jnn.2010.2339] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Nano-sized cobalt supported catalysts were prepared for Fischer-Tropsch synthesis in gas-to-liquid (GTL) process. The dependence of crystallite size and reducibility of Co3O4 on the supports were investigated with FTS activity. XRD peaks revealed nano crystallites (< 5.47 nm) of Co3O4 crystallites. TEM showed round shaped particles with size less than 5 nm. Support with higher acidity decreased crystallite size of Co3O4. XRD data of used catalysts showed Co3O4 crystallites smaller than 3.5 nm which do not reduce easily to Co(0) state. The crystallite size of Co3O4 plays a role in its reduction to Co(0). TPR results showed that the reduction temperature shifts to higher temperature due to metal-support interaction. The variation in the activity of the catalysts depends on the support which in turn affects the crystallite size, dispersion, reducibility and activity of Co species in Fischer-Tropsch Synthesis (FTS). In this study, Co/Al2O3 showed higher CO conversion than the other catalysts. However, the C5+ production was in order Co/SiO2 (78.1%) > Co/Al2O3 (70.0%) > Co/R_TiO2 (61%) > Co/A_TiO2 (57.5%).
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Affiliation(s)
- Jung Shik Kang
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul 136-791, Korea
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Yoon S, Sim H, Kim JS, Hong SI. A bioreactor with an internal contactor for primary recovery of bovine serum albumin from yeast suspension. KOREAN J CHEM ENG 2009. [DOI: 10.1007/s11814-009-0285-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Seo PW, Lee JY, Shim KS, Hong SH, Hong SC, Hong SI. The control of valence state: how V/TiO2 catalyst is hindering the deactivation using the mechanochemical method. J Hazard Mater 2009; 165:39-47. [PMID: 19059718 DOI: 10.1016/j.jhazmat.2008.09.119] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Revised: 07/17/2008] [Accepted: 09/19/2008] [Indexed: 05/27/2023]
Abstract
Various experiments were conducted to improve durability against SO(2) by impregnating the same amount of vanadium in TiO(2) which had the various physical properties. According to those catalysts, the degree of deactivation by SO(2) had various results, and it was found that the production of unreacted NH(3) in selective catalytic reduction reaction should be low. Based on X-ray photoelectron spectroscopy analysis, O(2) on-off test, O(2) reoxidation test and H(2)-temperature programmed reduction experiment, the redox capacity of catalyst was improved due to increasing of non-stoichiometric compounds. Such a non-stoichiometric oxide and redox capacity of catalyst can be enhanced by the ball-milling process, and the production of ammonium sulfate salt can be more easily inhibited by the superior oxidation-reduction capacity of catalyst. We found that this result is caused by producing and increasing of V(x+) (x<or=4), Ti(y+) (y<or=3) which are non-stoichiometric chemical species of catalyst.
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Affiliation(s)
- Phil-Won Seo
- Department of Chemical and Biological Engineering, Korea University, Republic of Korea
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Choi SH, Cho SP, Lee JY, Hong SH, Hong SC, Hong SI. The influence of non-stoichiometric species of V/TiO2 catalysts on selective catalytic reduction at low temperature. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.molcata.2009.02.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Hong SI, Hong SK, Wallace JM, Kohn DH. Ultrastructural observation of electron irradiation damage of lamellar bone. J Mater Sci Mater Med 2009; 20:959-965. [PMID: 19034616 DOI: 10.1007/s10856-008-3651-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2008] [Accepted: 11/03/2008] [Indexed: 05/27/2023]
Abstract
The ultrastructure of murine femoral lamellar bone and the effect of electron irradiation (200 kV) on collagen and mineral features were investigated using in situ high resolution transmission electron microscopy (HRTEM). Bands of collagen fibrils were mostly aligned parallel to the long axis of the bones, with some bands of fibrils inclined in longitudinal sections. The similarity of the ultrastructure between the longitudinal and transverse sections supports the rotated plywood structure of the lamellar bone. The collagen fibrils appeared damaged and the mineral crystals were coarsened after electron irradiation. Continuous diffraction rings became spotty and the contrast between rings and the background became sharper, further suggesting coarsening of apatite crystals and increased crystallinity after irradiation. No new phases were observed after irradiation. Both the damage to collagen and coarsening of apatite crystals can deteriorate the strength and integrity of bone, and may provide insight into fracture in patients who have undergone radiation therapy.
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Affiliation(s)
- S I Hong
- Department of Biologic and Materials Sciences, University of Michigan, Ann Arbor, MI, 48109-1078, USA.
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Park YG, Wey MY, Hong SI. Enhanced wear and fatigue properties of Ti-6Al-4V alloy modified by plasma carburizing/CrN coating. J Mater Sci Mater Med 2007; 18:925-31. [PMID: 17143738 DOI: 10.1007/s10856-006-0014-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2005] [Accepted: 12/29/2005] [Indexed: 05/12/2023]
Abstract
In this study, a newly developed duplex coating method incorporating plasma carburization and CrN coating was applied to Ti-6Al-4V and its effects on the wear resistance and fatigue life were investigated. The carburized layer with approximately150 microm in depth and CrN coating film with 7.5 microm in thickness were formed after duplex coating. Hard carbide particles such as TiC And V(4)C(3) were formed in the carburized layer. XRD diffraction pattern analysis revealed that CrN film had predominant [111] and [200] textures. The hardness (Hv) was significantly improved up to about 1,960 after duplex coating while the hardness value of original Ti-6Al-4V was 402. The threshold load for the modification and/or failure of CrN coating was measured to be 32 N using the acoustic emission technique. The wear resistance and fatigue life of duplex-coated Ti-6Al-4V improved significantly compared to those of un-treated specimen. The enhanced wear resistance can be attributed to the excellent adhesion and improved hardness of CrN coating film for the duplex-coated Ti-6Al-4V. The initiation of fatigue cracks is likely to be retarded by the presence of hard and strong layers on the surface, resulting in the enhanced fatigue life.
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Affiliation(s)
- Y G Park
- Department of Materials Engineering, Chungbuk National University, Cheongju, Korea
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Kang SW, Park CH, Hong SI, Kim SW. Production of penicillic acid by Aspergillus sclerotiorum CGF. Bioresour Technol 2007; 98:191-7. [PMID: 16458001 DOI: 10.1016/j.biortech.2005.11.033] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2004] [Revised: 11/21/2005] [Accepted: 11/24/2005] [Indexed: 05/06/2023]
Abstract
The production of penicillic acid by Aspergillus sclerotiorum CGF for the biocontrol of Phytophthora disease was investigated in submerged fermentation using media composed of different nutrients. Soluble starch was found to be the most effective substrate among the carbon sources used, and produced the highest penicillic acid concentration of 2.98 mg ml(-1). When organic nitrogen sources were used, pharmamedia, yeast extract, and polypeptone-S were found to be suitable organic nitrogen sources (2.46-2.71 mg ml(-1)). The production of penicillic acid was not detected in when inorganic nitrogen sources were used. Only Na2HPO4, among the metal ions and phosphate salts tested, increased the production of penicillic acid (approximately 20%). When A. sclerotiorum CGF was cultured in optimal medium [8.0% (w/v) soluble starch, 0.6% (w/v) yeast extract, and 0.3% (w/v) Na2HPO4], maximum penicillic acid concentration (approximately 9.40 mg ml(-1)) and cell mass (approximately 17.4 g l(-1)) were obtained after 12 days.
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Affiliation(s)
- S W Kang
- Graduate School of Biotechnology, Korea University, 1, Anam-dong, Seoul 136-701, Republic of Korea
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20
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Song MJ, Yun DH, Min NK, Hong SI. Electrochemical biosensor array for liver diagnosis using silanization technique on nanoporous silicon electrode. J Biosci Bioeng 2007; 103:32-7. [PMID: 17298898 DOI: 10.1263/jbb.103.32] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2006] [Accepted: 10/06/2006] [Indexed: 11/17/2022]
Abstract
An electrochemical biosensor array system was fabricated for the diagnosis and monitoring of liver diseases. Analysis on this array system with multiple samples was performed for point-of-care testing or home-use applications. Cholesterol, bilirubin and aminotransferases present in the serum are well-known biomarkers for liver diseases. For this study, we describe our biosensor array system consisting of cholesterol, bilirubin and glutamate sensors. To immobilize sensing enzymes on the array system, we employed a silanization technique. We observed that porous silicon layers formed on each working electrode notably increase the effective surface area. Sensing electrodes were placed in sampling wells to minimize the cross-interference effect so that multiple sampling would be possible with a low noise current. Compared with traditional analyte measurement procedures, our novel analytical device demonstrated acceptable sensitivities for the analyses of multiple samples and analytes without a marked cross-interference effect. The device sensitivities observed were 0.2656 microA/mM for cholesterol, 0.15354 mA/mM for bilirubin, 0.13698 microA/(U/l) for alanine aminotransferase (ALT) and 0.45439 microA/(U/l) for aspartate aminotransferase (AST).
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Affiliation(s)
- Min-Jung Song
- Department of Chemical and Biological Engineering, Korea University, 1, 5-Ga, Anam-dong, Sungbuk-ku, Seoul 136-701, Korea
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21
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Bae J, Kim D, Choi Y, Koh S, Park JE, Su Kim J, Moon SH, Park BH, Park M, Song HE, Hong SI, Lee DS. A hexokinase with broad sugar specificity from a thermophilic bacterium. Biochem Biophys Res Commun 2006; 334:754-63. [PMID: 16053915 DOI: 10.1016/j.bbrc.2005.06.160] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2005] [Accepted: 06/25/2005] [Indexed: 10/25/2022]
Abstract
A recombinant thermophilic Thermus caldophilus GK24 hexokinase, one of the ROK-type (repressor protein, open reading frames, and sugar kinase) proteins, exists uniquely as a 120 kDa molecule with four subunits (31 kDa), in contrast to eukaryotic and bacterial sugar kinases which are monomers or dimers. The optimal temperature and pH for the enzyme reaction are 70-80 degrees C and 7.5, respectively. This enzyme shows broad specificity toward glucose, mannose, glucosamine, allose, 2-deoxyglucose, and fructose. To understand the sugar specificity at a structural level, the enzyme-ATP/Mg2+-sugar binding complex models have been constructed. It has been shown that the sugar specificity is probably dependent on the interaction energy occurred by the positional proximity of sugars bound in the active site of the enzyme, which exhibits a tolerance to modification at C2 or C3 of glucose.
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Affiliation(s)
- Jungdon Bae
- Genome Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-333, Republic of Korea
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22
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Lee JH, Bae J, Kim D, Choi Y, Im YJ, Koh S, Kim JS, Kim MK, Kang GB, Hong SI, Lee DS, Eom SH. Stereoselectivity of fructose-1,6-bisphosphate aldolase in Thermus caldophilus. Biochem Biophys Res Commun 2006; 347:616-25. [PMID: 16843441 DOI: 10.1016/j.bbrc.2006.06.139] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Accepted: 06/21/2006] [Indexed: 10/24/2022]
Abstract
It was recently established that fructose-1,6-bisphosphate (FBP) aldolase (FBA) and tagatose-1,6-bisphosphate (TBP) aldolase (TBA), two class II aldolases, are highly specific for the diastereoselective synthesis of FBP and TBP from glyceraldehyde-3-phosphate (G3P) and dihydroxyacetone phosphate (DHAP), respectively. In this paper, we report on a FBA from the thermophile Thermus caldophilus GK24 (Tca) that produces both FBP and TBP from C(3) substrates. Moreover, the FBP:TBP ratio could be adjusted by manipulating the concentrations of G3P and DHAP. This is the first native FBA known to show dual diastereoselectivity among the FBAs and TBAs characterized thus far. To explain the behavior of this enzyme, the X-ray crystal structure of the Tca FBA in complex with DHAP was determined at 2.2A resolution. It appears that as a result of alteration of five G3P binding residues, the substrate binding cavity of Tca FBA has a greater volume than those in the Escherichia coli FBA-phosphoglycolohydroxamate (PGH) and TBA-PGH complexes. We suggest that this steric difference underlies the difference in the diastereoselectivities of these class II aldolases.
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Affiliation(s)
- Jun Hyuck Lee
- Department of Life Science, Gwangju Institute of Science and Technology, Republic of Korea
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Song MJ, Bae J, Lee DS, Kim CH, Kim JS, Kim SW, Hong SI. Purification and characterization of prodigiosin produced by integrated bioreactor from Serratia sp. KH-95. J Biosci Bioeng 2006; 101:157-61. [PMID: 16569612 DOI: 10.1263/jbb.101.157] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Accepted: 11/08/2005] [Indexed: 11/17/2022]
Abstract
To date, prodigiosin and its analogues which have been shown to have anticancer, cytotoxic and immunosuppressive activities have been isolated from Serratia, Pseudomonas and Streptomyces species, and chemically synthesized. In a previous study, the red pigment content in Serratia sp. KH-95 was enhanced using a casein-enriched medium. Recently, an integrated bioreactor with an internal adsorbent has been developed to increase the production yield and allow easy recovery of the pigment. Thus, this study focused on both purifying and identifying a single red pigment from several pigments attached to the adsorbent in an integrated bioreactor. The red pigment was extracted directly from the internal adsorbent using acidified methanol and phase separation. Subsequently, it was purified by silica gel chromatography and high performance liquid chromatograph (HPLC). As a result, pure prodigiosin was identified by structural studies as a pigment. Also, this downstream procedure that uses the integrated bioreactor can be applied to the direct production and purification of other prodigiosin analogues and hydrophobic alkaloid compounds from several microorganisms.
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Affiliation(s)
- Min-Jung Song
- Department of Chemical and Biological Engineering, Korea University, Seoul 136-701, Korea
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Ahn BY, Seok SI, Pramanik NC, Kim H, Hong SI. Redispersible rutile TiO2 nanocrystals in organic media by surface chemical modification with an inorganic barium hydroxide. J Colloid Interface Sci 2006; 297:138-42. [PMID: 16243346 DOI: 10.1016/j.jcis.2005.09.066] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2005] [Revised: 09/13/2005] [Accepted: 09/30/2005] [Indexed: 11/16/2022]
Abstract
The present paper describes the synthesis of the redispersible rutile TiO2 nanocrystals in organic media by surface chemical modification reaction in an aqueous barium hydroxide solution. In our facile surface modification reactions, the surfaces of the TiO2 nanocrystals are coated by bimetallic TiOBa spices and saturated with BaOH terminal groups. The inherent characteristics such as morphology, size, crystallinity, and color of the nanocrystals remained almost unchanged after surface-treatment, but their dispersibility in organic media such as methanol and DMF were remarkably enhanced. It is ascribed that BaOH groups in the surface of the TiO2 nanocrystals prevented the formation of covalently bound agglomerates through Ti-O-Ti condensation reaction among the nanocrystals during the purification and water-elimination procedures.
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Affiliation(s)
- Bok Yeop Ahn
- Advanced Materials Division, Korea Research Institute of Chemical Technology, 100 Jang-Dong, Yuseong-Gu, Daejon 305-600, South Korea
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Affiliation(s)
- Jungdon Bae
- Genome Research Center, Korea Research Institute of Bioscience and Biotechnology, Yuseong, Daejeon 305-333, Korea
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Abstract
Core/shell SiO2 and (RSiO1.5)(1-x)-(SiO2)x (R = alkyl) microcapsules were synthesized via a single-step O/W emulsion system using a self-templating method; the facile synthetic process provides an in-situ encapsulation route for a wide range of lipophilic functional compounds.
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Affiliation(s)
- Bok Yeop Ahn
- Advanced Materials Division, Korea Research Institute of Chemical Technology, Daejon, 305-343, Korea
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Jung WS, Kim S, Hong SI, Min NK, Lee CW, Paek SH. DNA probe chip system for multiple detection of food poisoning microorganisms. Materials Science and Engineering: C 2004. [DOI: 10.1016/j.msec.2003.09.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kang SW, Park YS, Lee JS, Hong SI, Kim SW. Production of cellulases and hemicellulases by Aspergillus niger KK2 from lignocellulosic biomass. Bioresour Technol 2004; 91:153-156. [PMID: 14592744 DOI: 10.1016/s0960-8524(03)00172-x] [Citation(s) in RCA: 164] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
To investigate the production of cellulases and hemicellulases from Aspergillus niger KK2, solid state fermentation (SSF) was performed by using different ratios of rice straw and wheat bran. When A. niger KK2 was grown on rice straw alone as a solid support in SSF, the maximum FPase activity was 19.5 IU g(-1) in 4 days. Also, CMCase (129 IU g(-1)), beta-glucosidase (100 IU g(-1)), xylanase (5070 IU g(-1)) and beta-xylosidase (193 IU g(-1)) activities were concurrently obtained after 5-6 days of fermentation. The higher enzyme activities produced by A. niger KK2 is a significant advantage from the viewpoint of practical saccharification reaction. Cellulases and hemicellulases produced by A. niger KK2 might be applied to pulp and paper industry, feed industry and chemical industry.
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Affiliation(s)
- S W Kang
- Graduate School of Biotechnology, Korea University, 1 Anam-dong, Sungbuk-ku, Seoul 136-701, South Korea
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29
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Moon H, Kim SW, Lee J, Rhee SK, Choi ES, Kang HA, Kim IH, Hong SI. Independent Exponential Feeding of Glycerol and Methanol for Fed-Batch Culture of Recombinant Hansenula polymorpha DL-1. Appl Biochem Biotechnol 2003; 111:65-80. [PMID: 14645999 DOI: 10.1385/abab:111:2:65] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2002] [Revised: 04/01/2003] [Accepted: 05/01/2003] [Indexed: 11/11/2022]
Abstract
As a novel feeding strategy for optimizing human epidermal growth factor (hEGF) production with a recombinant Hansenula polymorpha DL-1 using the methanol oxidase (MOX) promoter in H. polymorpha DL-1, independent exponential feeding of two substrates was used. A simple kinetic model considering the cell growth on two substrates was established and used to calculate the respective feeding rates of glycerol and methanol. In the fedbatch culture with methanol-only feeding, the optimal set point of specific growth rate on methanol was found to be 0.10 h-1. When the fed-batch cultures were conducted by the independent feeding of glycerol and methanol, the actual specific growth rate on glycerol and methanol was slightly lower than the set point of specific growth rate. By the uncoupled feeding of glycerol and methanol the volumetric productivity of hEGF increased from 6.4 to 8.0 mg/(L.h), compared with methanol-only feeding.
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Affiliation(s)
- H Moon
- Graduate School of Biotechnology, Korea University, Seoul 136-701, Korea
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30
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Abstract
AIMS To improve the production of clavulanic acid through the development of strains, the selection of a production medium and a pH shift strategy in a bioreactor. METHODS AND RESULTS Streptomyces clavuligerus mutant 15 was selected by antibacterial activities. As a result of pH control in a 2.5 l bioreactor, the highest productivity (3.37 microg x ml(-1) x h(-1)) was obtained at a controlled pH of 7.0. CONCLUSIONS The highest level of production obtained was an increase of about 36% compared with a non-controlled pH. When the production of clavulanic acid reached the maximum level, the pH was shifted from 7.0 to 6.0 for reduction in decomposition rate. The maximum concentration of clavulanic acid was maintained for 24 h as a result of the pH shift control, and a significant reduction in the decomposition of clavulanic acid was obtained. SIGNIFICANCE AND IMPACT OF THE STUDY Clavulanic acid decomposition was considerably reduced as a result of the pH shift control. The results of this study can be applied for the efficient production of beta-lactamase inhibitory antibiotics.
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Affiliation(s)
- S D Lee
- Department of Chemical Engineering, Korea University, Seoul, Korea
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31
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Park YS, Kang SW, Lee JS, Hong SI, Kim SW. Xylanase production in solid state fermentation by Aspergillus niger mutant using statistical experimental designs. Appl Microbiol Biotechnol 2002; 58:761-6. [PMID: 12021796 DOI: 10.1007/s00253-002-0965-0] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2001] [Revised: 01/22/2002] [Accepted: 01/31/2002] [Indexed: 10/27/2022]
Abstract
The initial moisture content, cultivation time, inoculum size and concentration of basal medium were optimized in solid state fermentation (SSF) for the production of xylanase by an Aspergillus niger mutant using statistical experimental designs. The cultivation time and concentration of basal medium were the most important factors affecting xylanase activity. An inoculum size of 5 x 10(5) spores/g, initial moisture content of 65%, cultivation time of 5 days and 10 times concentration of basal medium containing 50 times concentration of corn steep liquor were optimum for xylanase production in SSF. Under the optimized conditions, the activity and productivity of xylanase obtained after 5 days of fermentation were 5,071 IU/g of rice straw and 14,790 IU l(-1) h(-1), respectively. The xylanase activity predicted by a polynomial model was 5,484 IU/g of rice straw.
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Affiliation(s)
- Y S Park
- Graduate School of Biotechnology, Korea University, 1, Anam-dong, Sungbuk-ku, Seoul, 136-701, Korea
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Park IC, Park MJ, Woo SH, Lee KH, Lee SH, Rhee CH, Hong SI. Tumor necrosis factor-related apoptosis inducing ligand (TRAIL)-induced apoptosis is dependent on activation of cysteine and serine proteases. Cytokine 2001; 15:166-70. [PMID: 11554786 DOI: 10.1006/cyto.2001.0893] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We examined the role of caspases and serine protease(s) in cell death induced by tumour necrosis factor-related apoptosis-inducing ligand (TRAIL). After incubation of adenocarcinoma cells with TRAIL, caspase-3, -8 were activated and the cleavage of Bid induced the release of cytochrome c, from the mitochondria to the cytosol. Tetrapeptide inhibitors of caspase-1, -2, -3, and -8 suppressed DNA fragmentation and attenuated the release of cytochrome c, whereas inhibitors of caspase-5 did not. Interestingly, the general serine protease(s) inhibitor 4-(2-aminoethyl)benzylsulfonyl fluoride (AEBSF) resulted in the arrest of apoptosis. However, the AEBSF did not prevent the release of mitochondrial cytochrome c during TRAIL-induced apoptosis. From these results, we postulate that serine protease(s) may be involved in post-mitochondrial apoptotic events, that lead to the activation of the initiator, caspase-9.
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Affiliation(s)
- I C Park
- Laboratory of Cell Biology, Korea Cancer Center Hospital, 215-4 Gongneung-dong, Nowon-ku, 139-240 Seoul, South Korea
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Park IC, Park MJ, Rhee CH, Lee JI, Choe TB, Jang JJ, Lee SH, Hong SI. Protein kinase C activation by PMA rapidly induces apoptosis through caspase-3/CPP32 and serine protease(s) in a gastric cancer cell line. Int J Oncol 2001; 18:1077-83. [PMID: 11295059 DOI: 10.3892/ijo.18.5.1077] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phorbol 12-myristate 13-acetate (PMA) rapidly induced cell death in SNU-16 gastric adenocarcinoma cells. DNA ladder formation and caspase-3/CPP32 activation were observed in PMA treated cells indicating that PMA induces apoptosis. z-DEVD-fmk, specific inhibitor of caspase-3/CPP32, inhibited the induction of apoptosis by PMA, demonstrating that caspase/CPP32 are critically involved in PMA-induced apoptosis. The serine protein inhibitor 4-(2-aminoethyl)benzenesulfonyl fluoride effectively blocked apoptosis, and also prevented caspase-3/CPP32 activation. Go6983, a specific inhibitor of PKC, almost completely suppressed apoptosis and caspase-3/CPP32 activation. Furthermore, 1,2-dihexanoyl-sn-glycerol, an endogenous activator of PKC, induced apoptosis detected by DNA fragmentation and Hoechst 33258 nuclear staining. From these results, we conclude that PMA is not only a tumor promoter, but can also induce apoptosis in gastric cancer cells. PMA-induced apoptosis appears to be mediated through activation of protein kinase C, and the activation of serine protease(s) and caspase-3/CPP32 may be the molecular mechanisms by which PMA induces apoptosis.
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Affiliation(s)
- I C Park
- Laboratory of Cell Biology, Korea Cancer Center Hospital, Seoul 139-240, Korea
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Lee SH, Kang HS, Rhee CH, Kim MS, Kwon HC, Park MJ, Park IC, Lee CT, Kim CM, Hong SI. Growth-inhibitory effect of adenovirus-mediated p53 gene transfer on medulloblastoma cell line, Daoy, harboring mutant p53. Childs Nerv Syst 2001; 17:134-8. [PMID: 11305765 DOI: 10.1007/s003810000341] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
To improve the survival rate, gene therapy, such as the replacement of inactivated tumor suppressor genes, has become a new investigational adjuvant treatment modality for human malignancies. We investigated the effect of adenovirus(Ad)-mediated transfer of wildtype p53 tumor suppressor gene on the medulloblastoma cell line, Daoy, which harbors mutant-type p53 gene. At 50 multiplicity of infection (moi), immunohistochemical staining with p53 monoclonal antibody showed positive staining in all cells 2 days after Ad-CMV-p53 infection. The high expression of wild-type p53 protein was detected in Ad-CMV-p53-infected cells, and expression of wild-type p53 protein peaked on day 2 after the infection. The growth of Ad-CMV-p53-infected cells was greatly suppressed in vitro, and the Ad-CMV-p53 treatment significantly reduced the tumor mass in vivo. The mean weight of Ad-CMV- infected tumors was only 16% of those which were mock infected, and 25% of those which were Ad-CMV-beta-gal infected. On microscopic examination, Ad-CMV-p53-infected tumors showed numerous apoptotic bodies. This Ad-CMV-p53 gene transfer showed high transduction efficacy and expression, resulting in significant growth inhibition of Daoy harboring mutant type p53.
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Affiliation(s)
- S H Lee
- Laboratory of Cell Biology, Korea Cancer Center Hospital, Seoul.
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Lee SH, Kim MS, Kwon HC, Park IC, Park MJ, Lee CT, Kim YW, Kim CM, Hong SI. Growth inhibitory effect on glioma cells of adenovirus-mediated p16/INK4a gene transfer in vitro and in vivo. Int J Mol Med 2000. [PMID: 11029524 DOI: 10.3892/ijmm.6.5.559] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The tumour suppressor gene p16/INK4a encodes a specific inhibitor of the cyclin D-dependent kinases CDK4 and CDK6. p16/INK4a prevents the association of CDK4 with cyclin D1, and subsequently inhibits phosphorylation of retinoblastoma tumour suppressor protein (pRb), thus preventing exit from the G1 phase. In human cancers, the estimated frequency of genetic alteration involving the p16/INK4a locus is believed to be second only to alteration of p53. A high frequency (greater than 50%) of homozygous p16/INK4a gene deletion has been demonstrated in glioblastoma tissues and p16/INK4a is altered in 80% of glioma cell lines. Therefore, restoration of p16/INK4a would suppress cell proliferation and induce cell growth arrest. We showed here that restoration of p16/INK4a expression in p16 negative U87MG, U251MG and partially deleted U373MG by Ad-CMV-p16/INK4a induced growth suppression in vitro and in vivo. Expression of p16 transferred by Ad-CMV-p16/INK4a in glioma cells was highly efficient and maintained for more than seven days. In addition, we found that the endogenous status of p16 and Rb might affect the expression of exogenous p16/INK4a gene and inhibitory effect of cell proliferation. Even though, there were several factors affecting the efficiency of Ad-CMV-p16/INK4 gene transfer, our results suggest that Ad-CMV-p16 gene therapy strategy is potentially useful and warrants further clinical investigation for the treatment of gliomas.
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Affiliation(s)
- S H Lee
- Laboratory of Cell Biology, Korea Cancer Center Hospital, 215-4, Nowon-Ku, Gongneung-Dong, Seoul, 139-706, Korea.
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37
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Lee SH, Kim MS, Kwon HC, Park IC, Park MJ, Lee CT, Kim YW, Kim CM, Hong SI. Growth inhibitory effect on glioma cells of adenovirus-mediated p16/INK4a gene transfer in vitro and in vivo. Int J Mol Med 2000; 6:559-63. [PMID: 11029524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
The tumour suppressor gene p16/INK4a encodes a specific inhibitor of the cyclin D-dependent kinases CDK4 and CDK6. p16/INK4a prevents the association of CDK4 with cyclin D1, and subsequently inhibits phosphorylation of retinoblastoma tumour suppressor protein (pRb), thus preventing exit from the G1 phase. In human cancers, the estimated frequency of genetic alteration involving the p16/INK4a locus is believed to be second only to alteration of p53. A high frequency (greater than 50%) of homozygous p16/INK4a gene deletion has been demonstrated in glioblastoma tissues and p16/INK4a is altered in 80% of glioma cell lines. Therefore, restoration of p16/INK4a would suppress cell proliferation and induce cell growth arrest. We showed here that restoration of p16/INK4a expression in p16 negative U87MG, U251MG and partially deleted U373MG by Ad-CMV-p16/INK4a induced growth suppression in vitro and in vivo. Expression of p16 transferred by Ad-CMV-p16/INK4a in glioma cells was highly efficient and maintained for more than seven days. In addition, we found that the endogenous status of p16 and Rb might affect the expression of exogenous p16/INK4a gene and inhibitory effect of cell proliferation. Even though, there were several factors affecting the efficiency of Ad-CMV-p16/INK4 gene transfer, our results suggest that Ad-CMV-p16 gene therapy strategy is potentially useful and warrants further clinical investigation for the treatment of gliomas.
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Affiliation(s)
- S H Lee
- Laboratory of Cell Biology, Korea Cancer Center Hospital, 215-4, Nowon-Ku, Gongneung-Dong, Seoul, 139-706, Korea.
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Oh KK, Kim SW, Jeong YS, Hong SI. Bioconversion of cellulose into ethanol by nonisothermal simultaneous saccharification and fermentation. Appl Biochem Biotechnol 2000; 89:15-30. [PMID: 11069005 DOI: 10.1385/abab:89:1:15] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The kinetic characteristics of cellulase and beta-glucosidase during hydrolysis were determined. The kinetic parameters were found to reproduce experimental data satisfactorily and could be used in a simultaneous saccharification and fermentation (SSF) system by coupling with a fermentation model. The effects of temperature on yeast growth and ethanol production were investigated in batch cultures. In the range of 35-45 degrees C, using a mathematical model and a computer simulation package, the kinetic parameters at each temperature were estimated. The appropriate forms of the model equation for the SSF considering the effects of temperature were developed, and the temperature profile for maximizing the ethanol production was also obtained. Briefly, the optimum temperature profile began at a low temperature of 35 degrees C, which allows the propagation of cells. Up to 10 h, the operating temperature increased rapidly to 39 degrees C, and then decreased slowly to 36 degrees C. In this nonisothermal SSF system with the above temperature profile, a maximum ethanol production of 14.87 g/L was obtained.
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Affiliation(s)
- K K Oh
- Department of Industrial Chemistry, Dankook University, Cheonan, Korea
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39
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Park IC, Park MJ, Hwang CS, Rhee CH, Whang DY, Jang JJ, Choe TB, Hong SI, Lee SH. Mitomycin C induces apoptosis in a caspases-dependent and Fas/CD95-independent manner in human gastric adenocarcinoma cells. Cancer Lett 2000; 158:125-32. [PMID: 10960761 DOI: 10.1016/s0304-3835(00)00489-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We investigated the mechanism of mitomycin C (MMC)-induced apoptosis in SNU-16 human gastric adenocarcinoma cells. Caspase-8 and caspase-3 were activated in MMC-treated cells whereas caspase-1 was not activated, and cytochrome c was released from mitochondrial membrane to cytosol suggesting that caspase-9 was activated during the MMC-induced apoptotic process. Protein kinase C (PKC) delta was cleaved to its characteristic 40 kDa fragment in a caspase-3-dependent manner; on the other hand PKC zeta was cleaved to approximately 40 kDa independently of caspase-3 in the drug-induced apoptosis of the cells. Incubation with z-DEVD-fmk and benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (z-VAD-fmk) almost completely abrogated MMC-induced DNA fragmentation, indicating that activation of these caspases was crucially involved in MMC-induced apoptosis. Activation of caspase-8 in response to Fas triggering by recruitment of caspase-8 to the Fas has also been found, however, MMC did not induce FasL and Fas expression, as evidenced by reverse transcriptase-polymerase chain reaction and Western blotting. Taken together, these findings indicate that MMC-induced apoptosis in SNU-16 cells was mediated by caspase-8, caspase-9, and caspase-3 activation independently of FasL/Fas interactions.
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Affiliation(s)
- I C Park
- Laboratory of Cell Biology, Korea Cancer Center Hospital, 215-4 Gongneung-dong, Nowon-ku, 139-240, Seoul, South Korea
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40
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Park MJ, Park IC, Hur JH, Rhee CH, Choe TB, Yi DH, Hong SI, Lee SH. Protein kinase C activation by phorbol ester increases in vitro invasion through regulation of matrix metalloproteinases/tissue inhibitors of metalloproteinases system in D54 human glioblastoma cells. Neurosci Lett 2000; 290:201-4. [PMID: 10963898 DOI: 10.1016/s0304-3940(00)01358-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
To elucidate possible mechanisms of phorbol 12-myristate 13-acetate (PMA) induced in vitro invasiveness of glioblastoma cells, we examined expression levels of membrane-type 1 matrix metalloproteinase (MT1-MMP), MMP-2, MMP-9 and tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 using Western blotting and gelatin zymography assay, and found that PMA induced the secretion of MMP-9, activated MMP-2 proenzyme to fully active form of 59 kDa, down-regulated the TIMP-1 and TIMP-2 secretion, and increased MT1-MMP on the cell surface. However, PKC inhibitor Go 6983 reversed all of these effects brought about by PMA. We, therefore, conclude the activation of PKC by PMA in these cells plays a critical role in the regulation of MMPs/TIMPs system, which has a major role in tumor invasion and metastasis.
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Affiliation(s)
- M J Park
- Laboratory of Cell Biology, Korea Cancer Center Hospital, 215-4 Gongneung-dong, Nowon-ku, 139-240, Seoul, South Korea
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41
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Abstract
Glutathione S-transferase (GST) isoenzymes are involved in the detoxification of major carcinogens present in tobacco smoke. It is thus conceivable that deficiency in GST activity due to homozygous deletions of the GSTM1 and GSTT1 genes (the null genotypes) may modulate susceptibility to smoking-induced cancers. The influence of the GSTM1 and GSTT1 null genotypes on larynx cancer risk among the Korean population were evaluated using peripheral blood DNA from 82 larynx cancer patients and 63 healthy controls, all of whom were male current smokers. Increased larynx cancer risk was related to the GSTM1 null genotype (odds ratio (OR)=3.53, 95% confidence interval (CI)=1.27-9.83). The OR associated with the GSTT1 null genotype was also increased, but did not reach statistical significance (OR=1.83, 95% CI=0.70-4.79). Individuals lacking both the GSTM1 and GSTT1 genes were at a significantly higher risk for larynx cancer than individuals with both genes present (OR=4.04, 95% CI=1.33-12.30). These data confirm that the GSTM1 null genotype is an important risk modifier for larynx cancer among Korean smokers and combined GSTM1 and GSTT1 null genotypes could be a useful predictor of genetic susceptibility to larynx cancer.
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Affiliation(s)
- Y J Hong
- Department of Clinical Pathology, Korea Cancer Center Hospital, Seoul.
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42
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Lee JK, Hong YJ, Han CJ, Hwang DY, Hong SI. Clinical usefulness of serum and plasma vascular endothelial growth factor in cancer patients: which is the optimal specimen? Int J Oncol 2000. [PMID: 10853032 DOI: 10.3892/ijo.17.1.149] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Vascular endothelial growth factor (VEGF) is secreted by various human cancer cells and plays a key role in cancer angiogenesis and metastasis. Recently, evidence of VEGF storage in blood cells including platelets has been reported. The serum VEGF levels were reported to increase during clotting as a result of its release from platelets, and plasma sample instead of serum was recommended for measuring the circulating VEGF more accurately. However, platelets have been implicated in tumor metastasis since circulating tumor cells forming aggregates with platelets were observed. The purpose of this study was to clarify which is an optimal specimen to measure VEGF in cancer patients, serum or plasma. We measured serum and plasma VEGF levels and platelet counts in 173 cancer patients and 42 healthy people, and found that serum VEGF levels were significantly higher than matched plasma VEGF and the VEGF difference (serum VEGF - plasma VEGF) correlated with platelet counts (r=0.624, p<0.05) in both cancer patients and healthy controls. We selected cancer patients with normal platelet counts (130-400x103/microl, Plt-normal cancer group). Interestingly, serum VEGF levels were higher in Plt-normal cancer group than in healthy controls. The theoretical platelet-derived VEGF in serum, calculated based on actual blood platelet counts (pg per 106 platelets), was also significantly higher in Plt-normal cancer group than in normal controls. It is, therefore, suggested that, although the serum VEGF levels are affected by blood platelets, platelet-derived VEGF also reflect biology of cancer cells, and that serum would be the more useful specimen for measurement of circulating VEGF in cancer patients for prognosis.
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Affiliation(s)
- J K Lee
- Department of Clinical Pathology, Korea Cancer Center Hospital, Seoul
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Lee JK, Hong YJ, Han CJ, Hwang DY, Hong SI. Clinical usefulness of serum and plasma vascular endothelial growth factor in cancer patients: which is the optimal specimen? Int J Oncol 2000; 17:149-52. [PMID: 10853032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
Vascular endothelial growth factor (VEGF) is secreted by various human cancer cells and plays a key role in cancer angiogenesis and metastasis. Recently, evidence of VEGF storage in blood cells including platelets has been reported. The serum VEGF levels were reported to increase during clotting as a result of its release from platelets, and plasma sample instead of serum was recommended for measuring the circulating VEGF more accurately. However, platelets have been implicated in tumor metastasis since circulating tumor cells forming aggregates with platelets were observed. The purpose of this study was to clarify which is an optimal specimen to measure VEGF in cancer patients, serum or plasma. We measured serum and plasma VEGF levels and platelet counts in 173 cancer patients and 42 healthy people, and found that serum VEGF levels were significantly higher than matched plasma VEGF and the VEGF difference (serum VEGF - plasma VEGF) correlated with platelet counts (r=0.624, p<0.05) in both cancer patients and healthy controls. We selected cancer patients with normal platelet counts (130-400x103/microl, Plt-normal cancer group). Interestingly, serum VEGF levels were higher in Plt-normal cancer group than in healthy controls. The theoretical platelet-derived VEGF in serum, calculated based on actual blood platelet counts (pg per 106 platelets), was also significantly higher in Plt-normal cancer group than in normal controls. It is, therefore, suggested that, although the serum VEGF levels are affected by blood platelets, platelet-derived VEGF also reflect biology of cancer cells, and that serum would be the more useful specimen for measurement of circulating VEGF in cancer patients for prognosis.
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Affiliation(s)
- J K Lee
- Department of Clinical Pathology, Korea Cancer Center Hospital, Seoul
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Hur JH, Park MJ, Park IC, Yi DH, Rhee CH, Hong SI, Lee SH. Matrix metalloproteinases in human gliomas: activation of matrix metalloproteinase-2 (MMP-2) may be correlated with membrane-type-1 matrix metalloproteinase (MT1-MMP) expression. J Korean Med Sci 2000; 15:309-14. [PMID: 10895974 PMCID: PMC3054628 DOI: 10.3346/jkms.2000.15.3.309] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To evaluate possible roles of matrix metalloproteinase (MMP)-1, -2, tissue inhibitor of metalloproteinase (TIMP)-1, -2 and membrane-type-1 matrix metalloproteinase (MT1-MMP) in invasion of human gliomas, expressions of these proteins were investigated in ten cases of human glioma and two meningioma tissues and eight human glioma cell lines. In gelatin zymography, MMP-2 activities of glioblastomas were higher than astrocytomas. The activated form of MMP-2 was seen in five of six cases of glioblastomas, but not in astrocytomas. MMP-9 activity was detected in all cases of malignant astrocytomas but the reactivity of MMP-9 was weaker than that of MMP-2. MT1-MMP mRNA expression in glioblastomas was higher than that in astrocytomas. Five cases of glioblastomas with activated form of MMP-2 had MT1-MMP expressions. In vitro, human glioma cell lines with high expression of MT1-MMP also showed high MMP-2 activity. TIMP-1 transcripts were constitutively present in almost all glioma tissues and cell lines, whereas TIMP-2 mRNA were weak especially in malignant gliomas. Imbalance of TIMP-2/MMP-2 was observed using immunoprecipitation analysis in a glioma cell line. High expression of MMP-2 and MT1-MMP is possibly involved in invasiveness of malignant glioma.
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Affiliation(s)
- J H Hur
- Laboratory of Cell Biology, Korea Cancer Center Hospital, Seoul
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Park IC, Park MJ, Choe TB, Jang JJ, Hong SI, Lee SH. TNF-alpha induces apoptosis mediated by AEBSF-sensitive serine protease(s) that may involve upstream caspase-3/CPP32 protease activation in a human gastric cancer cell line. Int J Oncol 2000; 16:1243-8. [PMID: 10812002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
In the present study, we investigated the role of caspase-3/CPP32 and serine protease(s) in cell death induced by TNF-alpha in SNU-16 human gastric adenocarcinoma cells. Apoptosis induced in SNU-16 cells by TNF-alpha was accompanied by the activation of caspase-3/CPP32. After treatment with TNF-alpha, PKCdelta cleaved to its characteristic 40 kDa fragment in a caspase-3/CPP32 dependent manner. Incubation with z-DEVD-fmk completely abrogated TNF-alpha-induced DNA fragmentation, indicating that activation of caspase-3/CPP32 was crucially involved in TNF-alpha-induced apoptosis. In addition, serine protease inhibitor, 4-(2-aminoethyl)benzenesulfonyl fluoride (AEBSF), clearly inhibited all the features of apoptosis including DNA fragmentation and chromatin condensation. Furthermore, in the AEBSF treated SNU-16 cells, only intact PKCdelta was detected by immunoblot analysis, suggesting that activation of caspase-3/CPP32 was blocked. Thus, the AEBSF-sensitive step may involve an upstream caspase-3/CPP32 protease activation. Taken together, these results suggest that both caspase-3/CPP32 and serine protease(s) are activated and play an important role in TNF-alpha induced apoptosis in SNU-16 cells.
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Affiliation(s)
- I C Park
- Laboratory of Cell Biology, Korea Cancer Center Hospital, Nowon-gu, Seoul 139-706, Korea
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46
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Park IC, Park MJ, Choe TB, Jang JJ, Hong SI, Lee SH. TNF-alpha induces apoptosis mediated by AEBSF-sensitive serine protease(s) that may involve upstream caspase-3/CPP32 protease activation in a human gastric cancer cell line. Int J Oncol 2000. [DOI: 10.3892/ijo.16.6.1243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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48
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49
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Lee YS, Choe GY, Hong SI, Lee MJ, Kim TH, Jang JJ. Changes in natural killer cell activity and prostaglandin E2 levels during the progression of diethylnitrosamine-induced hepatocarcinogenesis in Fischer 344 rats. Oncol Rep 1998; 5:1441-5. [PMID: 9769384 DOI: 10.3892/or.5.6.1441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The sequential changes of natural killer cell (NK) activity and prostaglandin E2 (PGE2) during hepatocarcinogenesis induced by diethylnitrosamine (DEN) in male Fischer 344 rats were investigated. DEN at a concentration of 40 ppm was administered in drinking water for 10 weeks. At weeks 5, 10, 20 and 30, rats were autopsied and the development of glutathione S-transferase placental form positive foci (GST-P+ foci) at weeks 5 and 10 and hepatocellular tumors at weeks 20 and 30 were examined. The labeling index of bromodeoxyuridine (BrdU) an indicator of DNA synthesis, was also sequentially checked. GST-P+ foci were found to increase with age. Hepatocellular nodules increased until week 20, but by week 30 when the incidence of hepatocellular carcinoma was 100%, the incidence of nodules had decreased. BrdU positive cells also increased with age, and by week 30 when the incidence of hepatocellular carcinoma was 100%, the number of BrdU-positive cells had decreased. NK cell activity increased until week 10, but at week 20, was less than in the untreated control group. The level of PGE2 increased until week 5, but at week 10, levels were not significantly different from those seen in the untreated control group. On the basis of these results, we concluded that NK activity is closely related to the progression of hepatocarcinogenesis, but PGE2 levels show no significant change.
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Affiliation(s)
- Y S Lee
- Laboratory of Radiation Effect, Korea Cancer Center Hospital, Nowon-Ku, Seoul 139-706, Korea
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50
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Jung-Ha H, Kim D, Lee SB, Hong SI, Park SY, Huh J, Kim CW, Kim SS, Lee Y, Choi SS, Shin HS. Expression of Bfl-1 in normal and tumor tissues: Bfl-1 overexpression in cancer is attributable to its preferential expression in infiltrating inflammatory cells. Hum Pathol 1998; 29:723-8. [PMID: 9670830 DOI: 10.1016/s0046-8177(98)90282-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Bfl-1, a member of the Bcl-2 gene family, blocks p53-mediated apoptosis and has oncogenic transforming activity. In normal tissues, the transcript of Bfl-1 is expressed abundantly in bone marrow and at a low level in several other tissues. In previous experiments, elevated expression of Bfl-1 was observed by Northern analysis of stomach cancer samples. To study the role of Bfl-1 in normal cell development and in tumorigenesis, we have analyzed the expression of Bfl-1 in normal and tumor tissues by the in situ hybridization technique. The Bfl-1 transcript was detected in the white pulp of the spleen and in the germinal center of lymphatic tissues. In tumor tissues, its expression was preferentially detected in infiltrating inflammatory cells rather than in cancer cells, suggesting that Bfl-1 is not involved in tumorigenesis.
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Affiliation(s)
- H Jung-Ha
- Department of Biology, Andong National University, Korea
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