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Lee SH, Lee BC, Moon SY, Choi YS, Jang NY, Watanabe Y. Evaluation of a MF membrane system composed of pre coagulation-sedimentation and chlorination for water reuse. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2006; 54:115-21. [PMID: 17165454 DOI: 10.2166/wst.2006.876] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
In this research, we investigated the variation of transmembrane pressure and permeate water quality in pre-coagulation and sedimentation with iron based coagulant, and chlorination of feed water for PVDF (Polyvinylidene fluoride) based MF membrane filtration. NaCIO was fed to the membrane module at a dosage of 0.5 mg/L and maintained during filtration. To observe the effect of raw water, three types of raw and processed waters, including river surface water, coagulated water and coagulated-settled water, were employed. In the case of river surface water, the transmembrane pressure increased abruptly in 500 hours operation. On the contrary, no significant increase in transmembrane pressure was observed for coagulated water and coagulated-settled water for 1200 hours operation. The turbidity of permeate was lower than the detection limit for all applied waters. The removal efficiency for humic substances in coagulated water and coagulated-settled water was approximately ten times higher than that in surface river water. And, the removal efficiency for TOC and DOC was approximately two times higher than that in surface river water. From the results of the operation, it can be observed that it is possible to maintain stable operation at 0.9 m(3)/m(2)-day filtration flux through a combination of pre-coagulation and pre-chlorination. However, the water quality of permeate was the best when the pre-coagulation-sedimentation process was combined with pre-chlorination. With respect to fouling reduction and operation efficiency increase in membrane filtration, the pre-coagulation/sedimentation process is a promising alternative.
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Choi YS, Asaumi J, Yanagi Y, Hisatomi M, Konouchi H, Kishi K. A case of recurrent ameloblastoma developing in an autogenous iliac bone graft 20 years after the initial treatment. Dentomaxillofac Radiol 2006; 35:43-6. [PMID: 16421264 DOI: 10.1259/dmfr/13828255] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
A case of recurrent ameloblastoma developing in an autogenous iliac bone graft 20 years after radical resection of primary mandibular ameloblastoma is presented. This case showed extensive bony resorption extending throughout the auto-grafted bone. Seeding to the graft bone was suspected as a cause of the recurrence in the iliac bone graft because wide destruction of the graft bone was observed without any prior signs and symptoms of intraoral mucosa. Consequently, extensive resection of bone as well as adjacent soft tissue was performed. Persistent follow-up examination is essential for management of ameloblastoma.
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Choi YS, Kim KS. Plate augmentation leaving the nail in situ and bone grafting for non-union of femoral shaft fractures. INTERNATIONAL ORTHOPAEDICS 2005; 29:287-90. [PMID: 16132986 PMCID: PMC3456636 DOI: 10.1007/s00264-005-0668-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2005] [Accepted: 04/06/2005] [Indexed: 01/13/2023]
Abstract
We reviewed 15 patients with femoral non-union after interlocking intramedullary nailing treated with plate augmentation and bone grafting with the nail in situ. The mean time from primary nailing to plate augmentation and bone grafting was 10 months. At the time of presentation, the patients had undergone an average of 1.6 operations from the time of their original injury. To achieve stability of the fracture, we applied an AO plate on the lateral aspect of the femur. The retained nail maintained alignment of the fracture, and plating did not require an extensive surgical approach. In all patients, there was visible motion at the fracture site; however, the motion disappeared after plate augmentation. All patients achieved radiological solid union at an average of 7.2 months.
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Hong SW, Choi YS, Kwon G, Park KY. Performance evaluation of physicochemical processes for biologically pre-treated livestock wastewater. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2005; 52:107-15. [PMID: 16459782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The use of a combination of biological and physicochemical methods is a promising technique to reduce highly concentrated pollutants in livestock wastewater: firstly, biodegradable organic matters, nitrogen and a part of phosphorus should be removed in a biological treatment process and then residual non-biodegradable organic matters, color and phosphorus be eliminated by physicochemical methods. In this study, therefore, the integrations of chemical coagulation, activated carbon adsorption, Fenton oxidation and ozonation were evaluated to provide an appropriate post-treatment process for biologically pre-treated livestock wastewater. With applying a single method such as coagulation and Fenton oxidation, a yellowish brown color and COD still remained. According to the experimental result, the quality of treated wastewater including color was enough to be discharged after chemical coagulation followed by ozonation or Fenton oxidation process. Among these, ozonation was the most effective technology for decolorization. Neither simple biological nor physicochemical process provides an adequate treatability for the sufficient depletion of organics and decolorization when treating livestock wastewater. Considering only the removal efficiency, the integration of Fenton oxidation and ozonation would be an efficient alternative as a post-treatment.
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Hong SW, Choi YS, Kim SJ, Kwon G. Pilot-testing an alternative on-site wastewater treatment system for small communities and its automatic control. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2005; 51:101-8. [PMID: 16104411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The pilot test of a new alternative for small wastewater treatment system has been conducted for two years. It consists of a hybrid bioreactor and the expert system including the programmable logic controller and human-machine interface. In order to monitor its status, the real-time data was transferred from the remote station to the central station via a wireless local area network. More efficient and stable performances were observed at automatic operating mode compared with the manual. On an average, COD, SS, T-N and T-P concentrations in the effluent from the hybrid bioreactor were less than 14, 7, 12 and 0.9 mg/L, respectively. According to the result from laboratory experiments, the quality of treated wastewater with chemical coagulation process followed by sand filtration was enough to be utilized again if a final disinfection step is included.
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Choi YS, Lee J, Lui R. Traveling wave solutions for a one-dimensional crawling nematode sperm cell model. J Math Biol 2004; 49:310-28. [PMID: 15293016 DOI: 10.1007/s00285-003-0255-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2002] [Indexed: 11/25/2022]
Abstract
In this paper, we proved that the one-dimensional crawling nematode sperm cell model proposed by Mogilner and Verzi (2003) supports traveling wave solutions if there is no disassembly of unbundled filaments in the cell. Uniqueness of traveling wave is established under additional assumptions and numerical examples are also given in the paper. Mathematical methods used include dynamical system techniques, implicit function theorem and global bifurcation theory.
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Shin DH, Lee KS, Lee E, Chang YP, Kim JW, Choi YS, Kwon BS, Lee HW, Cho SS. Pax-7 Immunoreactivity in the Post-natal Chicken Central Nervous System. Anat Histol Embryol 2003; 32:378-83. [PMID: 14651488 DOI: 10.1111/j.1439-0264.2003.00496.x] [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: 11/29/2022]
Abstract
In this immunocytochemical study on the constitutive expression of Pax-7 protein in the postnatal chicken brain, Pax-7 showed region and cell type specific expression. In the optic tectum, only cells in grey matter showed positive immunoreactivities (IRs), whereas those in the white matters did not show any IRs. In thalamic nuclei and several pontine nuclei, we also localized Pax-7 positive IRs. On the contrary, in the cerebellum, Pax-7 was mainly localized within the Bergmann glia, whereas Purkinje cells did not show any IRs. In double immunolabelling studies, most of the Pax-7 IRs did not originate from neuroglial cells such as oligodendrocytes, microglia or astrocytes, but from neurons, with the exception of Bergmann glia in the cerebellum. The presence of Pax-7 IRs in the adult chicken brain could suggest that Pax-7 might play a role in maintaining normal physiological function in some postnatal chicken brain cells.
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Cho BL, Kim YS, Choi YS, Hong MH, Seo HG, Lee SY, Shin HC, Kim CH, Moon YS, Cha HS, Kim BS. Prevalence and risk factors for erectile dysfuntion in primary care: results of a Korean study. Int J Impot Res 2003; 15:323-8. [PMID: 14562132 DOI: 10.1038/sj.ijir.3901022] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
In order to assess the prevalence and associated factors for erectile dysfunction (ED) in primary care, a cross-sectional study was undertaken by questionnaire distributed to consecutive adult male attendees at 32 family practices. ED was assessed by the Korean five-item version of the International Index of Erectile Function (IIEF-5). In total, 3501 completed questionnaires were available for analysis. The prevalence of ED was severe (IIEF-5 score: 5-9) in 1.6% of cases, moderate (10-13) in 10.2%, mild (14-17) in 24.7%, and normal (18-25) in 63.4%. The prevalence of ED increased with age, lower educational status, heavy job-related physical activity, and lower income. ED prevalence was significantly higher in patients with chronic diseases such as diabetes, depression, and anxiety. These results suggest that the age-adjusted prevalence of ED among Korean men can be estimated as 32.2% (95% CI 30.6-33.7). Low socioeconomic status and several diseases such as diabetes, anxiety, and depression, as well as age, were associated with ED.
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84
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Kim HJ, Bae YC, Park RW, Choi SW, Cho SH, Choi YS, Lee WJ. Bone-protecting effect of safflower seeds in ovariectomized rats. Calcif Tissue Int 2002; 71:88-94. [PMID: 12073158 DOI: 10.1007/s00223-001-1080-4] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2001] [Accepted: 01/17/2002] [Indexed: 10/27/2022]
Abstract
Safflower (Carthamus tinctorius L.) seeds have long been clinically used in Korea to promote bone formation and prevent osteoporosis. However, the beneficial effect has not been scientifically evaluated. Thus, in the present study we investigated whether phytoestrogen rich safflower seeds reduce bone loss in ovariectomized rats. Female Sprague-Dawley rats were subjected to bilateral ovariectomy or sham surgery. One week after the operation, ovariectomized rats were either fed a diet containing defatted safflower seeds or injected with 17b-estradiol (E2) for 4 weeks. As expected, ovariectomy resulted in a dramatic reduction in trabecular bone mass of the proximal tibia, increase in deposition of marrow fat, and in uterine atrophy. E2 treatment almost completely prevented bone loss as well as marrow adiposity, as examined by scanning electron microscopy and histomorphometry. Safflower seeds partially prevented ovariectomy-induced bone loss and slightly reduced marrow adiposity. Safflower seeds, in contrast to E2, exerted very weak uterotrophic action. In an attempt to elucidate the underlying mechanisms, effect of polyphenolic compounds extracted from safflower seeds on proliferation of osteoblast-like cells was also assessed in vitro. The mixed polyphenolic compounds stimulated growth of ROS 17/2.8 osteoblast-like cells in a dose-dependent manner (5-100 mg/ml), as potently as E2 and genistein. The present data provide the first direct in vivo evidence that safflower seeds have a protecting effect on bone loss caused by estrogen deficiency, without substantial effect on the uterus. The beneficial effect of safflower seeds may be mediated, at least in part, by the stimulating effect of polyphenolic compounds on proliferation of osteoblasts.
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Kim MG, Kim BH, Choi JA, Lee NJ, Chung KB, Choi YS, Cho SB, Lim HC. Intra-articular ganglion cysts of the knee: clinical and MR imaging features. Eur Radiol 2002; 11:834-40. [PMID: 11372618 DOI: 10.1007/s003300000713] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The purpose of this study was to present clinical and MR imaging features of intra-articular ganglion cysts of the knee. Retrospective review of 1685 consecutive medical records and MR examinations of the knee performed at three imaging centers allowed identification of 20 patients (13 men and 7 women; mean age 35 years), in whom evidence of intra-articular ganglion cyst was seen. Of the 20 ganglion cysts, 5 were found in the infrapatellar fat pad, 10 arose from the posterior cruciate ligament, and 5 from the anterior cruciate ligament. Three of five patients with ganglion cyst in the infrapatellar fat pad had a palpable mass. In 7 of 15 patients with ganglion cyst in the intercondylar notch, exacerbation of pain occurred in a squatting position. On four MR arthrographies, ganglion cysts were an intra-articular round, lobulated, low signal intensity lesion. Five cases of fat-suppressed contrast-enhanced T1-weighted SE images demonstrated peripheral thin rim enhancement. The clinical presentation of intra-articular ganglion cyst is varied according to its intra-articular location. The MR appearance of intra-articular ganglion cyst is characteristic and usually associated with the cruciate ligament or the infrapatellar fat pad. Magnetic resonance arthrography has no definite advantage over conventional MR in the evaluation of the lesion. For intra-articular ganglion cyst in the infrapatellar fat pad, fat-suppressed contrast-enhanced MR imaging could be useful, because a thin, rim-enhancing feature of intra-articular ganglion cyst allows it to be distinguished from synovial hemangioma and synovial sarcoma.
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Choi YS, Hong SW, Kim SJ, Chung IH. Development of a biological process for livestock wastewater treatment using a technique for predominant outgrowth of Bacillus species. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2002; 45:71-78. [PMID: 12201129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The investigation has been carried out by treating 1 m3/day of livestock wastewater for 9 months. The biological process is composed of two reactors connected in series. Each reactor has been designed to stimulate the growth of Bacillus sp., spore-forming aerobic or facultatively anaerobic bacteria. As a consequence, the population of Bacillus sp. is aptly increased via the cycle of sporulation, germination and proliferation. With a predominant growth of Bacillus sp., the microbial activity has been increased comparing to activated sludge based on the result of measuring specific oxygen uptake rate (SOUR). This process was able to remove nitrogen and phosphorus as well as organic matter efficiently. More than 98% of biochemical oxygen demand (BOD) and chemical oxygen demand (COD) were removed. In term of removing the total nitrogen (T-N), about 98% of this was reduced. On average, the T-N concentration in the feed was 3,270 mg/l but 74 mg/l in the effluent including 30 mg/l of nitrite and nitrate nitrogen. The total phosphorus (T-P) reduction averaged 87.5%. As a result, it would be advantageous to load this process in order to deal with high-strength wastewater.
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87
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Shin JN, Choi YS, Lee HJ, Choi SH, Ha J, Yoon IJ, Nam H, Cha GS. A planar amperometric creatinine biosensor employing an insoluble oxidizing agent for removing redox-active interferences. Anal Chem 2001; 73:5965-71. [PMID: 11791567 DOI: 10.1021/ac010497a] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A planar microchip-based creatinine biosensor employing an oxidizing layer (e.g., a PbO2 film), where interfering redox-active substances are broken (i.e., oxidized) to redox-inactive products, was developed to facilitate the microfabrication of the sensor and to provide improved, reliable determination of creatinine in physiological samples. The feasibility of using hydrophilic polyurethanes in permselective barrier membranes for creatinine biosensors and the effect of adding a silanizing agent (adhesion promoter) on the sensor performance (e.g., sensitivity, stability, and lifetime) are described. The proposed creatinine microsensor with a three-layer configuration, i.e., enzyme, protecting, and oxidizing layers, exhibits good electrochemical performance in terms of response time (t95% = 98 s at 100-->200 microM creatinine change), linearity (1-1000 microM, r = 0.9997), detection limit (0.8 microM), and lifetime (approximately 35 days). The creatinine biosensor devised in a differential sensing arrangement that compensates the erroneous results from creatine is considered to be suitable for assay of serum specimens.
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Abstract
Mitochondrial DNA (mtDNA) content decreased in an age-dependent manner and may be one of the causal factors in age-related type 2 diabetes. Mitochondrial transcription factor A (mtTFA), which provides the replication primer, plays a key role for the regulation of mtDNA replication and its level is proportional to mtDNA. Here, we studied on the regulatory mechanism of mtTFA expression and the factors affecting the transcriptional activity of the mtTFA promoter. The promoter of human mtTFA contains 67 CpG dinucleotides. When the plasmids bearing the mtTFA promoter (2378 bp) linked to luciferase were transiently transfected into HepG2 cells, in vitro methylation of NRF-1 site by HhaI methylase abolished the mtTFA promoter activity up to 90%, implying that the CpG methylation of NRF-1 site inactivate mtTFA promoter-driven transcriptional activity. Besides the promoter methylation, the exogenous hydrogen peroxide or glucose also modulates the promoter activity of mtTFA. The bacterially overexpressed mtTFA protein exhibits a strong binding affinity to circular DNA (perhaps to mtDNA in mitochondria in vivo) and the protection of the DNA from cleavage by a hydrogen peroxide attack. Taken all these results together, age-related alterations of oxidative stress may affect mtDNA replication via regulating mtTFA activity. Furthermore, a vicious cycle may be present between mtTFA protein level and oxidative stress in the sense of DNA damage. Further studies were necessary to prove the presence of methyl cytosine in the mtTFA promoter of either an aged or a diabetic person and the effect of oxidative stress on the mtTFA function and expression resulting in a change of the mtDNA copy number.
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Choi YS. Saturation Characteristics of Cr(4)+:YAG Crystals and Dye Films for Passive Q Switches. APPLIED OPTICS 2001; 40:5417-5422. [PMID: 18364822 DOI: 10.1364/ao.40.005417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Measurements of the saturated transmission and the undepleted ground-state population density of both Cr(4+):YAG crystals and dye films as saturable absorbers have been experimentally attempted to understand the additional unsaturated losses in a high Q state. The saturated transmission of a saturable absorber is less than its maximum at a high saturation fluence because of the undepleted ground-state population density. Higher saturated transmission and lower undepleted ground-state population density have been observed for Cr(4+):YAG crystals than have been observed for dye films at high optical densities.
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On YK, Kim HS, Kim SY, Chae IH, Oh BH, Lee MM, Park YB, Choi YS, Chung MH. Vitamin C prevents radiation-induced endothelium-dependent vasomotor dysfunction and de-endothelialization by inhibiting oxidative damage in the rat. Clin Exp Pharmacol Physiol 2001; 28:816-21. [PMID: 11553021 DOI: 10.1046/j.1440-1681.2001.03528.x] [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: 11/20/2022]
Abstract
1. The present study was undertaken to determine whether endothelial function or morphology was altered in aortic rings of rats after irradiation, to investigate the mechanism of radiation effects on the endothelium and to examine the effect of vitamin C treatment against radiation-induced damage of the endothelium. 2. Female Sprague-Dawley rats were randomized into four groups (control, radiation, radiation + vitamin C, radiation + vitamin C + NG-nitro-L-arginine methyl ester (L-NAME); n = 10 for each group and n = 7 for the control group) and were irradiated with 10 Gy of 137Cs as a radiation source. Segments of the thoracic aorta were obtained and isometric tension, levels of 8-hydroxydeoxyguanosine (OH-dG) and immunohistochemical staining were measured. 3. Irradiation significantly impaired the acetylcholine-induced vasodilation of aortic segments, an effect that could be prevented by pretreatment with vitamin C (500 mg/kg per day). This beneficial effect of vitamin C was abolished by the addition of L-NAME (100 microg/kg per day), an inhibitor of nitric oxide (NO) synthesis. Irradiation significantly increased the level of OH-dG in the aorta (1.02 +/- 0.27 vs 2.61 +/- 0.78 OH-dG/105 deoxyguanosine (dG) for control and irradiated tissues, respectively; P < 0.01), an increase that was prevented by vitamin C treatment (1.59 +/- 0.23 OH-dG/105 dG; P < 0.01). Irradiation caused significant de-endothelialization (von Willebrand factor (vWF) staining was 93 +/- 7 vs 100% in irradiated and control tissues, respectively; P < 0.05) and this was prevented by vitamin C treatment (vWF staining 98 +/- 3%; P < 0.05). 4. Radiation caused endothelial damage and impaired NO production through oxidative injury, resulting in a selective impairment of endothelial-dependent vasodilation that could be prevented by vitamin C, partly through anti-oxidant mechanisms.
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91
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Hong SR, Lee SJ, Shim JW, Choi YS, Lee YM, Song KW, Park MH, Nam YS, Lee SI. Study on gelatin-containing artificial skin IV: A comparative study on the effect of antibiotic and EGF on cell proliferation during epidermal healing. Biomaterials 2001; 22:2777-83. [PMID: 11545312 DOI: 10.1016/s0142-9612(01)00021-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Gelatin-hyaluronate sponge with and without antibiotic and epidermal growth factor (EGF) were prepared and compared. Four types of sponges were applied on the full-thickness dorsal skin defect of Wistar rat. The effects of antibiotic and EGF in gelatin-hyaluronate sponge on wound healing were investigated by light microscopy and image analyzer at postoperative days of 5, 12 and 21. An immunohistochemical technique, employing PC10, a monoclonal antibody against proliferating cell nuclear antigen (PCNA) was applied to wounded tissue sections. The number of PC10-positive cells was very high for the sponge with EGF at postoperative day 5, then gradually decreased with time. Also we found that antibiotics restrained the cell proliferation during the migratory phase. The sponge with both antibiotic and EGF showed good wound healing performances on the whole for a healing period. The epithelium was regenerated fast with EGF-impregnated sponges at day 5, but each sample had nearly the same length of regenerated epithelium at day 12.
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Ro S, Lee HJ, Ahn IA, Shin DK, Lee KB, Yoon CJ, Choi YS. Torsion angle based design of peptidomimetics: a dipeptidic template adopting beta-I turn (Ac-Aib-AzGly--NH(2)). Bioorg Med Chem 2001; 9:1837-41. [PMID: 11425585 DOI: 10.1016/s0968-0896(01)00094-3] [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: 12/01/2022]
Abstract
We have attempted to design a model dipeptide (acetyl dipeptide amide, Ac-CA1-CA2--NH(2)) that can adopt specifically typical torsion angles of the beta-I turn (phi(i+1), psi(i+1), phi(i+2), psi(i+2)=-60 degrees, -30 degrees, -90 degrees, 0 degrees ). The key of the design is the combination of constrained amino acids that prefer to adopt the desired torsion angles. We chose Aib (aminoisobutyric acid) as the first residue of which phi and psi angles must be -60 degrees and -30 degrees, respectively. Then, we selected an azaamino acid as the second residue since previous studies have indicated that they prefer to adopt +/-90 degrees of phi angle and 0 degrees or 180 degrees of psi angle. The conformational preference of the resulting Ac-Aib-AzGly--NH(2) is investigated using ab initio methods. The conformations implying beta-I and beta-I' turns are energetically most favorable, as we expected. Thus, we synthesized the designed molecule on the solid phase considering the future generation of combinatorial libraries using an automatic peptide synthesizer. Then, NMR spectroscopy was carried out to confirm their conformational preference in solution was carried out. The results indicated that the Ac-Aib-AzGly--NH(2) adopt beta-I or beta-I' turns in solution forming an intramolecular hydrogen bonding between Ac--C(O) and terminal NH(2). We believe that such a small peptidomimetic template is highly useful for the design of drug candidates and molecular devices.
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Chung IJ, Choi YS, Hong SW, Park HM. Immobilization of arsenic in tailing by using iron and hydrogen peroxide. ENVIRONMENTAL TECHNOLOGY 2001; 22:831-835. [PMID: 11506207 DOI: 10.1080/095933322086180325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Under environmental conditions, arsenic (As) reveals anionic behavior and is converted into various forms in accordance with the Eh/pH condition. This causes the difficulty of treating As with other heavy metals in tailing. This study was carried out to develop the immobilization method of arsenic in tailing as ferric arsenate (FeAsO4) using hydrogen peroxide. According to experimental results, the extracted concentrations of arsenic and iron (Fe) from tailing were reduced up to 84% and 93%, respectively. In the experiment using pure Pyrite (FeS2) and As solution, As concentration decreased with an increase of hydrogen peroxide dosage. The experimental results of re-extraction showed that only 10% of As and 20% of Fe were extracted in the case of using hydrogen peroxide. As a result, the long-term stability of this method was clarified.
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Zhang X, Li L, Jung J, Xiang S, Hollmann C, Choi YS. The distinct roles of T cell-derived cytokines and a novel follicular dendritic cell-signaling molecule 8D6 in germinal center-B cell differentiation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:49-56. [PMID: 11418631 DOI: 10.4049/jimmunol.167.1.49] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Germinal center-B (GC-B) cells differentiate into memory B cells and plasma cells (PC) through interaction with T cells and follicular dendritic cells (FDC). Activated T cell and FDC play distinct roles in this process. The detailed kinetic experiments revealed that cytokines secreted by activated T cells determined the pathway of GC-B cell differentiation. IL-4 directs GC-B cells to differentiate into memory B cells, whereas IL-10 steers them into PC. FDC/HK cells do not direct either pathway, but provide signals for proliferation of GC-B cells. A novel FDC-signaling molecule 8D6 (FDC-SM-8D6) produced by FDC augments PC generation in the GC. FDC-SM-8D6-specific mAb blocked PC generation and IgG secretion but not memory B cell proliferation. COS cells expressing FDC-SM-8D6 enhanced GC-B cell proliferation and Ab secretion, which was blocked by mAb 8D6. In the cultures with B cell subsets, PC generation was inhibited by mAb 8D6 in the cultures with CD27(+) B cells but not in the culture with CD27(-) B cells, suggesting that CD27(+) PC precursor is the specific target of FDC-SM-8D6 stimulation.
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Lee IO, Kim SH, Kong MH, Lee MK, Kim NS, Choi YS, Lim SH. Pain after laparoscopic cholecystectomy: the effect and timing of incisional and intraperitoneal bupivacaine. Can J Anaesth 2001; 48:545-50. [PMID: 11444448 DOI: 10.1007/bf03016830] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
PURPOSE To examine the combined preemptive effects of somatovisceral blockade during laparoscopic cholecystectomy (LC). METHODS One hundred fifty-seven patients under general anesthesia receiving local infiltration and/or topical peritoneal local anesthesia were studied. Patients were randomized to receive a total of 150 mg (0.25% 60 mL) bupivacaine via periportal (20 mL) and intraperitoneal (40 mL with 1:200,000 epinephrine) administration of each. Group A received preoperative periportal bupivacaine before incision and intraperitoneal bupivacaine immediately after the pneumoperitoneum. Group B received periportal and intraperitoneal bupivacaine at the end of the operation. Group C (preoperative) and Group D (postoperative) received only periportal bupivacaine and Group E (preoperative) and Group F (post-operative) received only intraperitoneal bupivacaine. The control group received no treatment. Pain and nausea were recorded at one, two, three, six, nine, 12, 24, 36, and 48 hr postoperatively. RESULTS Throughout the postoperative 48 hr, incisional somatic pain dominated over other pain localizations in the control group (P <0.05). The incisional pain of groups A, B, C and D was significantly lower than that of the control group in the first and second hours. The incisional pain of groups A and C was significantly lower than that of the control group in the first three hours. CONCLUSION Incisional pain dominated during the first two post-operative days after LC. Preoperative somato-visceral or somatic local anesthesia reduced incisional pain during the first three post-operative hours. A combination of somato-visceral local anesthetic treatment did not reduce intraabdominal pain, shoulder pain or nausea more than somatic treatment alone. Preoperative incisional infiltration of local anesthetics is recommended.
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96
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Choi YS. Asymmetry of the Forward and Backward Raman Gain Coefficient at 1.54 mum in Methane. APPLIED OPTICS 2001; 40:1925-1930. [PMID: 18357193 DOI: 10.1364/ao.40.001925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The threshold pump energies at 1.06 mum and Raman gain coefficients of stimulated Raman scattering (SRS) at 1.54 mum have been measured in both single-pass and half-resonator configurations at various methane pressures. In the single-pass configuration, the Raman gain coefficients of the backward and forward SRS are 0.32 and 0.23 cm/GW at 95 atm, respectively. The backward Raman gain coefficient is higher than the forward Raman gain coefficient. This gain reduction is caused by the depletion of local pump intensity, the phase-matching conditions, and the transient effect of the high amplification rate in the forward SRS process. In the half-resonator configuration, the Raman gain coefficient was 0.46 cm/GW at 75 atm of methane.
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Sohn DW, Jung JW, Oh BH, Lee MM, Park YB, Choi YS, Lee YW. Should ascending aortic intramural hematoma be treated surgically? Am J Cardiol 2001; 87:1024-6; A5. [PMID: 11306002 DOI: 10.1016/s0002-9149(01)01444-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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98
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Sohn DW, Chung WY, Chai IH, Zo JH, Lee MM, Park YB, Choi YS, Lee YW. Mitral annulus velocity in the noninvasive estimation of left ventricular peak dP/dt. Am J Cardiol 2001; 87:933-6. [PMID: 11274960 DOI: 10.1016/s0002-9149(00)01546-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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99
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Lee SK, Lee JH, Han CH, Ahn YM, Choi YS, Kim IO. Calcified subcutaneous fat necrosis induced by prolonged exposure to cold weather: a case report. Pediatr Radiol 2001; 31:294-5. [PMID: 11321751 DOI: 10.1007/s002470000415] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present a 22-day-old infant with extensive subcutaneous calcifications due to subcutaneous fat necrosis caused by prolonged exposure to cold.
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100
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Kagami Y, Jung J, Choi YS, Osumi K, Nakamura S, Morishima Y, Seto M. Establishment of a follicular lymphoma cell line (FLK-1) dependent on follicular dendritic cell-like cell line HK. Leukemia 2001; 15:148-56. [PMID: 11243383 DOI: 10.1038/sj.leu.2402002] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A novel cell line, FLK-1, was established from bone marrow cells of a patient with follicular lymphoma by means of co-culture with follicular dendritic cell (FDC)-like cell line HK. Immunophenotypic analysis showed that FLK-1 expressed CD10, CD19, CD20, CD38, IgG and HLA-DR, which is a typical feature of germinal center B cells. Cytogenetic analysis of FLK-1 demonstrated t(14;18)(q32;q21) translocation involving BCL2 and immunoglobulin heavy chain genes. Especially noteworthy is that the growth of FLK-1 was found to be dependent on a FDC line, HK. When HK cells were removed from the culture, FLK-1 cells stopped growing and eventually died. An apoptotic mechanism appeared to be involved as indicated by the presence of chromosome condensation and DNA ladder formation. The culture experiment using micropore membranes showed that soluble factor(s) of HK cells supported the growth, while direct cell-to-cell contact appeared to be necessary for longterm cell proliferation. These findings suggest the importance of the micro-environment for follicular lymphoma cells to grow. The FLK-1 cell line may thus prove to be useful for studying the growth mechanism of follicular lymphoma and provide new insights into the pathogenesis of follicular lymphoma.
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