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Park SE, Kim EB, Park YH, Yee DS, Kwon TY, Park CY, Moon HS, Yoon TH. Sweep optical frequency synthesizer with a distributed-Bragg-reflector laser injection locked by a single component of an optical frequency comb. OPTICS LETTERS 2006; 31:3594-6. [PMID: 17130914 DOI: 10.1364/ol.31.003594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
A sweep optical frequency synthesizer is demonstrated by using a frequency-stabilized optical frequency comb and injection-locked distributed-Bragg-reflector (DBR) laser diode. The injection-locked DBR laser acts as a single-frequency filter and, simultaneously, a high-gain amplifier of the optical frequency comb. The frequency instability of the heterodyne beat signal between two independently injection-locked DBR lasers is measured to be 2.3 x 10(-16) at 1 s averaging time. The output frequency of the sweep optical frequency synthesizer can be precisely tuned over 1 GHz, and a saturated absorption spectrum of the Cs D2 line at 852 nm is recorded by the injected DBR laser.
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Lee KB, Lee JM, Park CY, Lee KB, Cho HY, Ha SY. What is the difference between squamous cell carcinoma and adenocarcinoma of the cervix? A matched case–control study. Int J Gynecol Cancer 2006; 16:1569-73. [PMID: 16884367 DOI: 10.1111/j.1525-1438.2006.00628.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The objective of this study was to investigate the efficacy of treatment strategies in patients with adenocarcinoma (AC) of the cervix and compare it with those with squamous cell carcinoma (SCC) of the cervix. Women with FIGO (1994) stage IB1 AC, especially pathologic tumor size of 2-4 cm, treated with class III hysterectomy, were compared with those with SCC treated with comparable strategy in a case-controlled study. Eighty patients (20 cases, 60 controls) were analyzed. Lymphvascular space invasion (P = 0.01) and lymph node metastasis (P = 0.07) were more frequent in patients with SCC than in those with AC. However, there was no significant difference in depth of stromal invasion (P = 0.51) and invasion of the parametrium (P = 0.44) between two groups. And there was also no statistically significant difference in disease-free survival (P = 0.86) and overall survival (P = 0.89) between two groups. Primary radical surgery followed by adjuvant therapy, same as for SCC, would be acceptable for AC with pathologic tumor size of 2-4 cm. Although it was difficult to determine whether AC recurred more systemically, more effective treatment strategies than those currently available for AC should be considered to reduce the systemic recurrence.
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Lee JM, Lee KB, Park CY. Prognostic factors predicting survival in patients with FIGO stage IB cervical cancer treated surgically. Int J Gynaecol Obstet 2006; 94:143-4. [PMID: 16687146 DOI: 10.1016/j.ijgo.2006.01.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2005] [Revised: 01/23/2006] [Accepted: 01/25/2006] [Indexed: 10/24/2022]
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Lee KBM, Lee JM, Park CY, Lee KB, Cho HY, Ha SY. Lymph node metastasis and lymph vascular space invasion in microinvasive squamous cell carcinoma of the uterine cervix. Int J Gynecol Cancer 2006; 16:1184-7. [PMID: 16803504 DOI: 10.1111/j.1525-1438.2006.00566.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The objective of this study was to determine whether the depth of invasion was related to lymph vascular space invasion (LVSI) and lymph node metastasis and whether there was a correlation between LVSI and lymph node metastasis in stage IA cervical cancer. The medical records, including surgical notes and pathologic reports, of 202 patients with microinvasive squamous cell carcinoma of the uterine cervix were reviewed retrospectively. There was a positive correlation between the depth of invasion and the LVSI, and the incidence of lymph node metastasis was slightly higher than those reported hitherto for stage IA1 cervical cancer, especially in the depth of invasion of 1-3 mm group. However, among four patients with lymph node metastasis, only two patients had positive LVSI. There was no definite correlation between LVSI and lymph node metastasis. LVSI could not identify the patients with high risk for lymph node metastasis.
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Lee KB, Lee JM, Park CY, Lee KB, Cho HY, Ha SY. Lymph node metastasis and lymph vascular space invasion in microinvasive squamous cell carcinoma of the uterine cervix. Int J Gynecol Cancer 2006. [DOI: 10.1136/ijgc-00009577-200605000-00036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
The objective of this study was to determine whether the depth of invasion was related to lymph vascular space invasion (LVSI) and lymph node metastasis and whether there was a correlation between LVSI and lymph node metastasis in stage IA cervical cancer. The medical records, including surgical notes and pathologic reports, of 202 patients with microinvasive squamous cell carcinoma of the uterine cervix were reviewed retrospectively. There was a positive correlation between the depth of invasion and the LVSI, and the incidence of lymph node metastasis was slightly higher than those reported hitherto for stage IA1 cervical cancer, especially in the depth of invasion of 1–3 mm group. However, among four patients with lymph node metastasis, only two patients had positive LVSI. There was no definite correlation between LVSI and lymph node metastasis. LVSI could not identify the patients with high risk for lymph node metastasis.
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Hong SB, Uhm SJ, Lee HY, Park CY, Gupta MK, Chung BH, Chung KS, Lee HT. Developmental Ability of Bovine Embryos Nuclear Transferred with Frozen-thawed or Cooled Donor Cells. ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES 2005. [DOI: 10.5713/ajas.2005.1242] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Lyu SC, Liu BC, Lee SH, Park CY, Kang HK, Yang CW, Lee CJ. Large-Scale Synthesis of High-Quality Single-Walled Carbon Nanotubes by Catalytic Decomposition of Ethylene. J Phys Chem B 2004. [DOI: 10.1021/jp030661t] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Choi J, Park JW, Jo YH, Lee JJ, Kim WE, Park CY, Kim J, Min BG. Estimation of coupled assist flows in a moving-actuator bi-ventricular assist device using interventricular pressure. Int J Artif Organs 2003; 26:758-63. [PMID: 14521174 DOI: 10.1177/039139880302600809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
An assist flow estimation scheme for a moving-actuator biventricular assist device (MA-BVAD) using interventricular pressure (IVP) has been developed. The scheme uses a waveform feature parameter of IVP, peak IVP time (PIT), for estimation of the filling volumes of both left and right blood sacs simultaneously. In a regression analysis on data from an in vivo test in an 85 Kg male calf for 20 days, the PIT was found to have high correlation with the blood sac filling volume (R=0.883: left filling volume, R=0.967: right filling volume). A conceptual equation hypothesizing this correlation between PIT and filling volume was established based on the observation and the unknown parameters were identified using least squares parameter optimization. The estimation equation identified proved highly accurate (R=0.916 for left flow, R=0.970 for right flow). The accuracy of the estimation scheme promises very good practical applicability.
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Park JW, Choi J, Lee JJ, Nam K, Chung J, Park SK, Park CY, Sun K, Kim WG, Kim J, Min BG. AnyHeart: a single-piece heart-saving implantable artificial heart (BVAD)--monitoring and estimation. Int J Artif Organs 2003; 26:406-10. [PMID: 12828307 DOI: 10.1177/039139880302600506] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
AnyHeart is a single-piece, implantable biventricular assist device. This electromechanical BVAD has a moving-actuator mechanism. To monitor the status of AnyHeart from anywhere at any time, a portable personal digital assistant (PDA) monitor and web-based remote monitoring system were developed. The PDA local monitoring system has replaced bulky personal computer monitoring systems. The web-based remote monitoring system has several functions such as data collecting, storing, and posting through the internet. Basically, interventricular pressure (IVP) is a parameter indicating the filling level of the blood chambers of AnyHeart. The pump output can be estimated using IVP, which is acquired noninvasively from AnyHeart. With the proposed method, we can estimate the pump output with a small margin of error.
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Lyu SC, Liu BC, Lee TJ, Liu ZY, Yang CW, Park CY, Lee CJ. Synthesis of high-quality single-walled carbon nanotubes by catalytic decomposition of C2H2. Chem Commun (Camb) 2003:734-5. [PMID: 12703797 DOI: 10.1039/b300109a] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
High-quality single-walled carbon nanotubes free of defects and amorphous carbon coating have been produced by catalytic decomposition of C2H2 over Fe-Mo/Al2O3 catalyst.
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Kim HJ, Park CY, Park YH, Kim YJ, Kim DW, Min WS, Kim CC. Successful allogeneic hematopoietic stem cell transplantation using triple agent immunosuppression in severe aplastic anemia patients. Bone Marrow Transplant 2003; 31:79-86. [PMID: 12621487 DOI: 10.1038/sj.bmt.1703786] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Graft rejection in patients with severe aplastic anemia (SAA) following allogeneic hematopoietic stem cell transplantation (HSCT) is strongly associated with a large number of prior transfusions and with prolonged disease duration before transplant. We retrospectively analyzed the outcomes and the factor affecting these multitransfused SAA patients, who had received triple agent immunosuppression and high doses of stem cells to overcome rejection. In total, 113 patients with SAA who had a median 16 months (range 1-216) of disease duration were transplanted using HLA-matched sibling donors after conditioning with cyclophosphamide (CY), procarbazine (PCB), and ATG. Graft failure occurred in 16 of the eligible 113 patients, and with a median follow-up of 30 months (range, 1-80), probability of overall rejection was 15%. Specifically, the multitransfused patients who received high doses of stem cells with T-cell depletion showed the lowest rejection rate, 5.6%, compared with 30.3% in multitransfused patients with bone marrow stem cells alone (P=0.0310). Disease duration (P=0.0338) and the number of infused CD34+cells (P=0.0101) were associated with a high risk of graft rejection on multivariate analysis. ABO mismatch and the number of CD34+ cells were significant factors in the incidence of acute graft-versus-host-disease (GVHD). The incidence of chronic GVHD among patients with sustained engraftment was 13/109 (11.9%). With the same follow-up period, probability of disease-free survival for the entire group of patients at 6 years was 89% and the only factor associated with long-term survival was rejection (P=0.0241). These results suggest that allogeneic HSCT conditioned with triple agent immunosuppression, and specifically with high-dose stem cell return is probably an effective treatment for successful engraftment in SAA patients with a high risk of rejection.
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Park CY, Yi JJ, Joo MH, You HS. Broadcasting health programmes among audience and professionals in Korea: perceptions and needs. Asia Pac J Public Health 2002; 13 Suppl:S13-8. [PMID: 12109241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Mass media has become an essential part of modern society, and it should be noted that mass media plays an important role in delivering information even in the area of health. This study was intended to investigate the perceptions of and needs for broadcasting health programmes among audience and related professionals in Korea, which will serve to help in the development of valuable health programmes. Data were collected through a series of self-administered questionnaire surveys conducted on two types of subjects sampled from residents in the areas around Seoul, Korea, and health or broadcasting professionals working on health programmes. There were some discrepancies in the perceptions of and needs for health programmes between audience and professionals, especially the main audience age group and image, needs for topics and mode of health programme. In conclusion, in order to enhance current health programmes which focus on aspects of diagnosis and treatment of diseases, the range of health programmes should be expanded to fulfill various needs.
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Kang HY, Park CY, Kim HJ. Assessing public understanding of the policy of separating dispensing and prescribing in Korea: a survey of college students. Asia Pac J Public Health 2002; 13 Suppl:S23-30. [PMID: 12109243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
We investigated the level of public understanding of the 'separation of dispensing and prescribing' health policy in Korea and its associated factors. A questionnaire survey was conducted upon 700 college students at four months after the introduction of the policy. The understanding level was measured using four question items describing the goal and motivation of the policy, and ten items describing its operational rules. For each item, respondents were asked to mark whether the description was true or false. While the goal and motivation of the policy was relatively well informed (mean understanding score: 69.58 out of 100), people did not have a good understanding of the operational details of the policy (mean score: 32.52). The results of regression analyses showed that personal interest and agreement with the need of the policy were the most significant factors affecting the understanding level (p < 0.01). It is concluded that, for other public policies in the future, policy makers in Korea need to develop more effective media communication strategies to effectively inform the public of the practical details of the policy.
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Lee HS, Rho YR, Park CY, Hwang CM, Kim WG, Sun K, Choi MJ, Lee KK, Cheong JT, Shim EB, Min BG. Application of the moving-actuator type pump as a ventricular assist device: in vitro and in vivo studies. Int J Artif Organs 2002; 25:556-61. [PMID: 12117296 DOI: 10.1177/039139880202500611] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A moving actuator type pump has been developed as a multifunctional Korean artificial heart (AnyHeart). The pump consists of a moving actuator as an energy converter, right and left sacs, polymer (or mechanical) valves, and a rigid polyurethane housing. The actuator containing a brushless DC motor moves back and forth on an epicyclical gear train to produce a pendular motion, which compresses both sacs alternately. Of its versatile functions of ventricular assist device and total artificial heart use, we have evaluated the system performance as a single or biventricular assist device through in vitro and in vivo experiments. Pump performance and anatomical feasibility were tested using various animals of different sizes. In the case of single ventricular assist device (VAD) use, one of the sacs remained empty and a mini-compliance chamber was attached to either an outflow or inflow port of the unused sac. The in vitro and in vivo studies show acceptable performance and pump behavior. Further extensive study is required to proceed to human application.
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Kang SY, Ahn IY, Park CY, Chung YB, Hong ST, Kong Y, Cho SY, Hong SJ. Clonorchis sinensis: molecular cloning and characterization of 28-kDa glutathione S-transferase. Exp Parasitol 2001; 97:186-95. [PMID: 11384162 DOI: 10.1006/expr.2001.4606] [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: 11/22/2022]
Abstract
A 28-kDa glutathione S-transferase (Cs28GST) was purified from a Clonorchis sinensis cytosolic fraction through anion-exchange and glutathione-affinity column chromatographies. A monoclonal antibody raised against Cs28GST reacted specifically to the C. sinensis antigen among trematode proteins. A putative peptide of 212 amino residues deduced from a cDNA clone appeared homologous with 28-kDa GST of trematodes, and its secondary structural elements predicted a GSH-binding site. Recombinant Cs28GST showed GST enzyme activity with CDNB substrate and was sensitive to the model inhibitors. The recombinant Cs28GST was antigenically indistinguishable from the native form and was recognized specifically by C. sinensis-infected human sera. The Cs28GST was localized in the tegument and underlying mesenchymal tissues. It is suggested that Cs28GST may play significant physiological roles against bioreactive molecules and be a useful reagent for serodiagnosis of clonorchiasis.
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Oga A, Kong G, Ishii Y, Izumi H, Park CY, Sasaki K. Preferential loss of 5q14-21 in intestinal-type gastric cancer with DNA aneuploidy. CYTOMETRY 2001; 46:57-62. [PMID: 11241508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
BACKGROUND Little is known about the genetic changes associated with DNA ploidy in gastric cancer (GC). The aim of this study was to identify recurrent or specific chromosomal regions of DNA sequence copy number aberrations (DSCNAs) that might harbor genes associated with DNA aneuploidy in GC. METHODS We analyzed DSCNAs with comparative genomic hybridization and DNA ploidy by laser scanning cytometry in 16 primary intestinal-type GCs. RESULTS All GCs examined showed at least one DSCNA (loss or gain); eight were DNA diploid (DD) tumors and eight were DNA aneuploid (DA) tumors. The frequent (>30%) DSCNAs were loss of 5q14-21 and gains of 7p11-14, 8q, 20q, and Xq25-26. Recurrent amplifications (>10%) were detected at chromosomal regions 6p, 7p, and 13q. The overall number of DSCNAs was significantly greater in DA than in DD tumors (P = 0.006). Furthermore, the number of aberrations was clearly greater with 5q loss than without 5q loss (P = 0.002). Losses of 5q14-21, 9p21-pter, 16q, and 18q21-qter were preferentially detected in DA tumors. CONCLUSION The present observations indicate that there is a close relationship between DSCNA and DNA ploidy in intestinal-type GC and that gene(s) at 5q14-21, 9p21-pter, 16q, and/or 18q21-qter may play important roles in acquisition of DNA aneuploidy.
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Kim KA, Park CY, Lim Y, Lee KH. Recent advances in particulate-induced pulmonary fibrosis; for the application of possible strategy experimentally and clinically. Curr Drug Targets 2000; 1:297-307. [PMID: 11465077 DOI: 10.2174/1389450003349146] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chronic interstitial lung diseases including pneumoconiosis have pathological characteristics which alter the lung structure and function consequent to the accumulation and activation of inflammatory cells in the lower respiratory tract. These activated cells usually secrete the inflammatory and fibrogenic mediators. Of the diffuse parenchymal lung diseases, the majority have no known etiology and idiopathic pulmonary fibrosis (IPF) is the diagnosis most frequently encountered by clinicians. Pathogenic similarities between pneumoconiosis and IPF provide a strong basis for hypothesizing that environmental agents may cause IPF. Many case-control studies have been published that provide further evidence for a number of associations between occupational and environmental exposures and IPF. Such reports support a strong evidence that IPF may be a heterogenous disorder associated with a number of environmental exposures. As a model of lung fibrosis, experimental pneumoconiosis is giving us a great information because crystalline silica is probably one of the most typical agent producing pulmonary fibrosis and the severity of its health effects and the widespread nature of exposure have been long recognized. Many papers provide evidence that particles have the potential to cause stimulation of phagocytes to release oxidants and such oxidative stress is believed to be a major factor in pulmonary inflammation followed by fibrotic change. Many kinds of cellular mediators are recognized as a implicating factor in this process including cell-to-cell interaction, enzymes, cytokines, arachidonic acid derivatives et al. Treatment of pneumoconiosis is an attractive and interesting topic. But, the mechanism of pathogenesis of pneumoconiosis is not thoroughly understood yet. Also, whether the process of fibrosis formation be retarded or not is questionable with some therapeutic trial. Therefore, a sensitive biomarker which is possible to estimate the pathological pathway in pneumoconiosis is needed. Our laboratory has studied particulate-induced pulmonary reaction for two decades consistently. This review will focus on signal transduction pathway involved in oxidative stress and some inhibitory agents with pleiotropic mechanism in pulmonary fibrosis. I will also introduce some data of animal studies with multidrug regimen as well.
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Chung WS, Lee SH, Kim JC, Heo WD, Kim MC, Park CY, Park HC, Lim CO, Kim WB, Harper JF, Cho MJ. Identification of a calmodulin-regulated soybean Ca(2+)-ATPase (SCA1) that is located in the plasma membrane. THE PLANT CELL 2000; 12:1393-407. [PMID: 10948258 PMCID: PMC149111 DOI: 10.1105/tpc.12.8.1393] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2000] [Accepted: 05/24/2000] [Indexed: 05/17/2023]
Abstract
Ca(2)+-ATPases are key regulators of Ca(2+) ion efflux in all eukaryotes. Animal cells have two distinct families of Ca(2+) pumps, with calmodulin-stimulated pumps (type IIB pumps) found exclusively at the plasma membrane. In plants, no equivalent type IIB pump located at the plasma membrane has been identified at the molecular level, although related isoforms have been identified in non-plasma membrane locations. Here, we identify a plant cDNA, designated SCA1 (for soybean Ca(2+)-ATPase 1), that encodes Ca(2+)-ATPase and is located at the plasma membrane. The plasma membrane localization was determined by sucrose gradient and aqueous two-phase membrane fractionations and was confirmed by the localization of SCA1p tagged with a green fluorescent protein. The Ca(2+)-ATPase activity of the SCA1p was increased approximately sixfold by calmodulin (K(1/2) approximately 10 nM). Two calmodulin binding sequences were identified in the N-terminal domain. An N-terminal truncation mutant that deletes sequence through the two calmodulin binding sites was able to complement a yeast mutant (K616) that was deficient in two endogenous Ca(2+) pumps. Our results indicate that SCA1p is structurally distinct from the plasma membrane-localized Ca(2+) pump in animal cells, belonging instead to a novel family of plant type IIB pumps found in multiple subcellular locations. In plant cells from soybean, expression of this plasma membrane pump was highly and rapidly induced by salt (NaCl) stress and a fungal elicitor but not by osmotic stress.
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Cho HS, Song JY, Park CY, Lyu CJ, Kim BS, Kim KY. Retroviral-mediated IL-2 gene transfer into murine neuroblastoma. Yonsei Med J 2000; 41:76-81. [PMID: 10731923 DOI: 10.3349/ymj.2000.41.1.76] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
We used retroviral-mediated gene transfer of the human interleukin (IL)-2 gene into murine neuroblastoma cells to investigate whether locally-secreted IL-2 is able to influence the generation of anti-tumor immune responses. Supernatant obtained from cultures of approximately 1 x 10(6) IL-2 gene-transduced, G-418 selected neuro-2a cells was assayed for human IL-2 production by ELISA kit. First, to estimate whether the local secretion of IL-2 from the genetically-modified tumor cells would affect their tumorigenicity in vivo, IL-2-secreting neuro-2a cells were s.c. injected into A/J mice and tumor growth was measured weekly. And to estimate whether IL-2 transfected neuroblastoma cells protect mice from tumor development after wild-type tumor cell challenge, IL-2-secreting neuro-2a cells were s.c. injected into A/J mice. Seven days after IL-2 gene-transfected neuroblastoma cell injection, unmodified neuro-2a cells were s.c. injected into the contralateral site of A/J mice and tumor growth was measured weekly. Finally, to estimate IL-2 effect on pre-established large tumor burdens, IL-2-secreting neuro-2a cells were s.c. injected into A/J mice with established tumor and its growth was measured weekly. The IL-2 gene-transduced neuro-2a clones secreted 120.25-177.3 IU of IL-2 per ml per 10(6) cells during 24 hr. None of the mice injected with IL-2-secreting neuro-2a cells developed tumors within 6 weeks, while all of the mice injected with wild-type neuro-2a cells developed tumors. Immunization of mice with IL-2 gene-transfected, irradiated neuro-2a cells protected these animals against a subsequent challenge with wild-type tumor cells. Finally, the size of large neuroblastomas decreased after IL-2-secreting neuro-2a cell injection into mice. Local secretion of IL-2 gene-transduced tumor cells abrogates their tumorigenicity and induces protective immunity and may inhibit the growth of neuroblastoma.
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Kim JK, Lim Y, Kim KA, Seo MS, Kim JD, Lee KH, Park CY. Activation of telomerase by silica in rat lung. Toxicol Lett 2000; 111:263-70. [PMID: 10643871 DOI: 10.1016/s0378-4274(99)00195-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
By measuring the activity of telomerase in a silica-instilled rat lung, the study found a significant increase in telomerase activity compared to that of the control. Pneumoconiosis displays the characteristics of fibroblast-proliferation and accumulation of collagen, which finally causes the pathologic changes of irreversible and progressive fibrosis of the lung. On the basis of the hypothesis that cellular proliferation may trigger telomerase-activity, the experiment was carried out with telomerase-activation in silicosis. Silica-instilled rat lungs showed increased activity of telomerase, which was measured by TRAP (telomeric repeat amplification protocol) assay, at the time of the 1st, 5th and 8th week after intratracheal instillation of silica in vivo. However, no activity was shown in silica-co-cultured fibroblast in vitro. By summarizing these results, the activity of telomerase is thought to be a very sensitive marker for the evaluation of pathogenicity, showing cellular immortalization in an experimental silicosis model.
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Lee SH, Kim MC, Heo WD, Kim JC, Chung WS, Park CY, Park HC, Cheong YH, Kim CY, Lee KJ, Bahk JD, Lee SY, Cho MJ. Competitive binding of calmodulin isoforms to calmodulin-binding proteins: implication for the function of calmodulin isoforms in plants. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1433:56-67. [PMID: 10446359 DOI: 10.1016/s0167-4838(99)00149-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In plants, multiple calmodulin (CaM) isoforms exist in an organism which vary in their primary structures in as much as 32 residues out of their 148 amino acids. These CaM isoforms show differences in their expression patterns and/or target enzyme activation ability. To further understand the biological significance of CaM isoforms, we examined whether CaM isoforms act on specific regulatory targets. In gel overlay assays on various soybean tissue extracts, surprisingly, two soybean CaM isoforms (SCaM-1 and SCaM-4) did not show significant differences in their target binding protein profiles, although they exhibited minor differences in their relative target binding affinities. In addition, both SCaM isoforms not only effectively bound five known plant CaMBPs, but also showed competitive binding to these proteins. Finally, immunolocalization experiments with the SCaM proteins in sections of various tissues using specific antibodies revealed similar distribution patterns for the SCaM isoforms except for root tissues, which indicates that the SCaM isoforms are concomitantly expressed in most plant tissues. These results suggest that CaM isoforms may compete for binding to CaMBPs in vivo. This competitive nature of CaM isoforms may allow modulation of Ca(2+)/CaM signaling pathways by virtue of relative abundance and differential target activation potency.
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Shin DC, Kim HJ, Jung SH, Park CY, Lee SY, Kim CB. Pesticide poisoning and its related factors among Korean farmers. LA MEDICINA DEL LAVORO 1999; 89 Suppl 2:S129-35. [PMID: 10217934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
This study has been carried out to assess the health damages due to pesticide use and its related risk factors among Korean farmers. Data regarding pesticide handling and poisoning symptoms were collected by means of a questionnaire filled in by 1,032 farmers from two provinces. The results showed that during summer farming 21.9% of the subjects experienced suspected pesticide poisoning. 18.8% mild poisoning, and 2% more serious poisoning. Univariate and logistic regression analyses between "no poisoning", including the "suspected poisoning" and "poisoning" groups, were performed to select significant variables related to pesticide poisoning. Four variables were significantly associated: sex, days of consecutive pesticide use, hours of pesticide use per day, having received safety education (weakly associated), and compliance with safety guidelines for application. Safety education was weakly associated with poisoning, while age, education, wearing protective gear, and compliance with safety guidelines for personal hygiene after pesticide use were not significant risk factors to determine pesticide poisoning.
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Park CY, Hayman MJ. The tyrosines in the bidentate motif of the env-sea oncoprotein are essential for cell transformation and are binding sites for Grb2 and the tyrosine phosphatase SHP-2. J Biol Chem 1999; 274:7583-90. [PMID: 10066827 DOI: 10.1074/jbc.274.11.7583] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The transforming gene product of the S13 avian erythroblastosis virus, the env-sea protein, is a member of the hepatocyte growth factor receptor family of tyrosine kinases comprising Met, Ron, and Sea. Like all three members of this family, the env-sea protein has a so-called bidentate motif (Y557INMAVTY564VNL) composed of two tandemly arranged tyrosines in the carboxyl terminus. To investigate whether the tyrosine residues in this motif are essential for the env-sea-mediated transformation, we generated tyrosine to phenylalanine mutations. Substitutions of both tyrosine residues resulted in complete loss of the transforming activity. In contrast, single mutations at either tyrosine did not inhibit transformation of Rat1 cells, and mutation of tyrosine 564 actually increased transformation of Rat 1 cells. To define signaling pathways activated by the env-sea protein, we looked for protein-protein interactions mediated by these tyrosine residues. We show that the bidentate motif is responsible for interaction with the adapter protein Grb2, phosphatidylinositol 3-kinase, and the tyrosine phosphatase SHP-2. Furthermore, we show that microinjected Src homology 2 domains from either Grb2 or SHP-2 blocked the transforming activity of the env-sea protein. Together, these results suggest that the tyrosines within the bidentate motif are essential for the env-sea transformation.
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Heo WD, Lee SH, Kim MC, Kim JC, Chung WS, Chun HJ, Lee KJ, Park CY, Park HC, Choi JY, Cho MJ. Involvement of specific calmodulin isoforms in salicylic acid-independent activation of plant disease resistance responses. Proc Natl Acad Sci U S A 1999; 96:766-71. [PMID: 9892708 PMCID: PMC15211 DOI: 10.1073/pnas.96.2.766] [Citation(s) in RCA: 209] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/1998] [Indexed: 11/18/2022] Open
Abstract
The Ca2+ signal is essential for the activation of plant defense responses, but downstream components of the signaling pathway are still poorly defined. Here we demonstrate that specific calmodulin (CaM) isoforms are activated by infection or pathogen-derived elicitors and participate in Ca2+-mediated induction of plant disease resistance responses. Soybean CaM (SCaM)-4 and SCaM-5 genes, which encode for divergent CaM isoforms, were induced within 30 min by a fungal elicitor or pathogen, whereas other SCaM genes encoding highly conserved CaM isoforms did not show such response. This pathogen-triggered induction of these genes specifically depended on the increase of intracellular Ca2+ level. Constitutive expression of SCaM-4 and SCaM-5 in transgenic tobacco plants triggered spontaneous induction of lesions and induces an array of systemic acquired resistance (SAR)-associated genes. Surprisingly, these transgenic plants have normal levels of endogenous salicylic acid (SA). Furthermore, coexpression of nahG gene did not block the induction of SAR-associated genes in these transgenic plants, indicating that SA is not involved in the SAR gene induction mediated by SCaM-4 or SCaM-5. The transgenic plants exhibit enhanced resistance to a wide spectrum of virulent and avirulent pathogens, including bacteria, fungi, and virus. These results suggest that specific CaM isoforms are components of a SA-independent signal transduction chain leading to disease resistance.
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Lee KS, Park CY, Meng KH, Bush A, Lee SH, Lee WC, Koo JW, Chung CK. The association of cigarette smoking and alcohol consumption with other cardiovascular risk factors in men from Seoul, Korea. Ann Epidemiol 1998; 8:31-8. [PMID: 9465991 DOI: 10.1016/s1047-2797(97)00113-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE To explore the effects of cigarette smoking and alcohol consumption on cardiovascular disease risk factors such as hypertension, dyslipidemia, and glucose intolerance in Korean men. METHODS In this cross-sectional study, we gathered the smoking and drinking history by self-administered questionnaire between June 1994 and May 1995 among 1053 men, age 20-77, who visited a prevention center for a multiphasic health check at St. Mary's Hospital, Seoul. RESULTS Cigarette smoking had a significant inverse association with systolic and diastolic blood pressure. Adjusted for age, body mass index (BMI), and alcohol consumption, the odds ratio of hypercho-lesterolemia (> or = 240 mg/dl) was 1.30 (95% confidence interval (CI) 1.09-1.55), lower high density lipoprotein (HDL) cholesterol (< 40 mg/dl) was 1.29 (95% CI 1.08-1.54), higher low density lipoprotein (LDL) cholesterol (> or = 160 mg/dl) was 1.30 (95% CI 1.07-1.56), and hypertriglyceridemia (> or = 200 mg/dl) was 1.40 (95% CI 1.16-1.68) among men who smoked 21-30 cigarettes per day compared with nonsmokers. Adjusted for age. BMI, and cigarette smoking in men who consumed 90-179 and 180-269 g/week of alcohol compared with nondrinkers, the odds ratio of hypertension was 1.73 (95% CI 1.01-3.00) and 1.48 (95% CI 1.01-2.17), respectively. Alcohol consumption had a significant protective effect (adjusted odds ratio: 0.60-0.78) against lower HDL cholesterol in all categories > or = 90 g of alcohol per week compared with nondrinkers. The adjusted odds ratio of hypertriglyceridemia was 1.17 (95% CI 1.04-1.31), and glucose intolerance (fasting blood sugar (FBS) > or = 120 mg/dl) was 1.27 (95% CI 1.11-1.14) among those who consumed > or = 360 g/week of alcohol compared with nondrinkers. CONCLUSIONS In this Korean population study, although alcohol consumption increased HDL cholesterol, which might have a protective effect on coronary heart disease, cigarette smoking was associated with decreased blood pressure, smoking was confirmed to have dyslipidemic effect such as increasing total cholesterol, LDL cholesterol, triglyceride and decreasing HDL cholesterol, and alcohol consumption was confirmed to be associated with hypertension, hypertriglyceridemia, and glucose intolerance as in Caucasian. Further prospective intervention studies are needed for evaluating cardiovascular effects after cessation of smoking and drinking.
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