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Oh JY, Song CY, Ko YJ, Lee JM, Kang WN, Yang DS, Kang B. Strong correlation between flux pinning and epitaxial strain in the GdBa 2Cu 3O 7-x /La 0.7Sr 0.3MnO 3 nanocrystalline heterostructure. RSC Adv 2020; 10:39102-39108. [PMID: 35518394 PMCID: PMC9057360 DOI: 10.1039/d0ra06431a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 10/19/2020] [Indexed: 11/24/2022] Open
Abstract
The effect of magnetic flux pinning is investigated in GdBa2Cu3O7 (GdBCO) thin films with two different types of ferromagnetic La0.7Sr0.3MnO3 (LSMO) buffers (nanoparticles and a layer) deposited on an STO substrate. Magnetization analyses reveal the presence of multiple flux pinning mechanisms responsible for the improvement in the critical current density of GdBCO films. While core pinning becomes a dominant pinning mechanism in GdBCO films with LSMO nanoparticles, a hybrid effect of magnetic-volume and core-point pinning is observed in GdBCO films with LSMO layers. Examinations of local structures for both LSMO and GdBCO using extended X-ray absorption fine structure spectroscopy (EXAFS) exhibit a close relation between the parameters in the pinning force scaling and the length ratio of the Mn–O bond to the Cu–O bond. This result implies that the origin of core pinning is probably attributed to epitaxial strain induced by lattice mismatch between LSMO and GdBCO. Therefore, an appropriate strain state of LSMO is required for an effective operation of magnetic pinning. The effect of magnetic flux pinning is investigated in GdBa2Cu3O7 (GdBCO) thin films with two different types of ferromagnetic La0.7Sr0.3MnO3 (LSMO) buffers (nanoparticles and a layer) deposited on an STO substrate.![]()
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Affiliation(s)
- J Y Oh
- Department of Physics, Chungbuk National University Cheongju Korea +82 43 274 7811 +82 43 261 3394
| | - C Y Song
- Department of Physics, Chungbuk National University Cheongju Korea +82 43 274 7811 +82 43 261 3394
| | - Y J Ko
- Department of Physics, Chungbuk National University Cheongju Korea +82 43 274 7811 +82 43 261 3394
| | - J M Lee
- Department of Physics, Sungkyunkwan University Suwon Korea
| | - W N Kang
- Department of Physics, Sungkyunkwan University Suwon Korea
| | - D S Yang
- Department of Physics Education, Chungbuk National University Cheongju Korea
| | - B Kang
- Department of Physics, Chungbuk National University Cheongju Korea +82 43 274 7811 +82 43 261 3394
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Kim WY, Kang BJ, Chung CR, Park SH, Oh JY, Park SY, Cho WH, Sim YS, Cho YJ, Park S, Kim JH, Hong SB. Prone positioning before extracorporeal membrane oxygenation for severe acute respiratory distress syndrome: A retrospective multicenter study. Med Intensiva 2019; 43:402-409. [PMID: 29983197 PMCID: PMC10036879 DOI: 10.1016/j.medin.2018.04.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 04/05/2018] [Accepted: 04/29/2018] [Indexed: 11/21/2022]
Abstract
OBJECTIVE To evaluate the clinical outcomes of patients with severe acute respiratory distress syndrome (ARDS) subjected to prone positioning before extracorporeal membrane oxygenation (ECMO). DESIGN A retrospective analysis of a multicenter cohort was carried out. SETTING Patients admitted to the Intensive Care Units of 11 hospitals in Korea. PATIENTS Patients were divided into those who underwent prone positioning before ECMO (n=28) and those who did not (n=34). INTERVENTIONS None. VARIABLES OF INTEREST Thirty-day mortality, ECMO weaning failure rate, mechanical ventilation weaning success rate, mechanical ventilation-free days at day 60. RESULTS The prone group had lower median peak inspiratory pressure and lower median dynamic driving pressure before ECMO. Thirty-day mortality was 21% in the prone group and 41% in the non-prone group (p=0.098). The prone group also showed a lower ECMO weaning failure rate, and a higher mechanical ventilation weaning success rate and more mechanical ventilation-free days at day 60. In the non-prone group, median dynamic compliance marginally decreased shortly after ECMO, but no significant change was observed in the prone group. CONCLUSIONS Prone positioning before ECMO was not associated to increased mortality and tended to exert a protective effect.
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Affiliation(s)
- W-Y Kim
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Pusan National University School of Medicine, Busan, Republic of Korea
| | - B J Kang
- Department of Internal Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea
| | - C R Chung
- Department of Critical Care Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - S H Park
- Department of Pulmonary and Critical Care Medicine, Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - J Y Oh
- Division of Pulmonology and Critical Care Medicine, Dongguk University Ilsan Hospital, Dongguk University College of Medicine, Goyang, Republic of Korea
| | - S Y Park
- Department of Internal Medicine, Chonbuk National University Medical School, Jeonju, Republic of Korea
| | - W H Cho
- Department of Pulmonology and Critical Care Medicine, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea
| | - Y S Sim
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Hallym University Kangnam Sacred Heart Hospital, Seoul, Republic of Korea
| | - Y-J Cho
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - S Park
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea
| | - J-H Kim
- Department of Internal Medicine, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, Republic of Korea
| | - S-B Hong
- Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
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Kim WY, Kang BJ, Chung CR, Park SH, Oh JY, Park SY, Cho WH, Sim YS, Cho YJ, Park S, Kim JH, Hong SB. Prone positioning before extracorporeal membrane oxygenation for severe acute respiratory distress syndrome: A retrospective multicenter study. Med Intensiva 2018. [PMID: 29983197 DOI: 10.1016/j.medin.2018.04.013.] [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] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2022]
Abstract
OBJECTIVE To evaluate the clinical outcomes of patients with severe acute respiratory distress syndrome (ARDS) subjected to prone positioning before extracorporeal membrane oxygenation (ECMO). DESIGN A retrospective analysis of a multicenter cohort was carried out. SETTING Patients admitted to the Intensive Care Units of 11 hospitals in Korea. PATIENTS Patients were divided into those who underwent prone positioning before ECMO (n=28) and those who did not (n=34). INTERVENTIONS None. VARIABLES OF INTEREST Thirty-day mortality, ECMO weaning failure rate, mechanical ventilation weaning success rate, mechanical ventilation-free days at day 60. RESULTS The prone group had lower median peak inspiratory pressure and lower median dynamic driving pressure before ECMO. Thirty-day mortality was 21% in the prone group and 41% in the non-prone group (p=0.098). The prone group also showed a lower ECMO weaning failure rate, and a higher mechanical ventilation weaning success rate and more mechanical ventilation-free days at day 60. In the non-prone group, median dynamic compliance marginally decreased shortly after ECMO, but no significant change was observed in the prone group. CONCLUSIONS Prone positioning before ECMO was not associated to increased mortality and tended to exert a protective effect.
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Affiliation(s)
- W-Y Kim
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Pusan National University School of Medicine, Busan, Republic of Korea
| | - B J Kang
- Department of Internal Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea
| | - C R Chung
- Department of Critical Care Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - S H Park
- Department of Pulmonary and Critical Care Medicine, Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - J Y Oh
- Division of Pulmonology and Critical Care Medicine, Dongguk University Ilsan Hospital, Dongguk University College of Medicine, Goyang, Republic of Korea
| | - S Y Park
- Department of Internal Medicine, Chonbuk National University Medical School, Jeonju, Republic of Korea
| | - W H Cho
- Department of Pulmonology and Critical Care Medicine, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea
| | - Y S Sim
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Hallym University Kangnam Sacred Heart Hospital, Seoul, Republic of Korea
| | - Y-J Cho
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea
| | - S Park
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea
| | - J-H Kim
- Department of Internal Medicine, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, Republic of Korea
| | - S-B Hong
- Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
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Oh JY, Sim JK, Jung WJ, Min KH, Lee EJ, Hur GY, Lee SY, Lee SY, Kwon AM, Kim JH, Shin C, Shim JJ, In KH, Kang KH, Lee SH. Association between interleukin-27 polymorphisms and pulmonary tuberculosis. Int J Tuberc Lung Dis 2016; 19:702-8. [PMID: 25946363 DOI: 10.5588/ijtld.14.0773] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE To investigate the effect of interleukin (IL) 27 -964A/G, 2095T/G, 4603G/A and 4730T/C gene polymorphisms on the development of pulmonary tuberculosis (PTB), radiographic characteristics and severity. DESIGN Differences in the allele and genotype distributions of the -964A/G, 2095T/G, 4603G/A and 4730T/C polymorphisms between 224 PTB patients and 233 healthy controls, between patients with single- and multi-lobe involvement, and between patients with and without cavitation, were investigated. Serum IL-27 concentration was measured using an enzyme-linked immunosorbent assay. RESULTS There were no significant differences in the allele or genotype distributions between PTB patients and healthy controls. However, the -964A/A genotype was more prevalent in patients with single-lobe involvement than the -964A/G or -964G/G genotype in patients with multi-lobe involvement (50.0% vs. 31.3%, P = 0.01). There was no difference between patients with and without cavitation (P > 0.05). Serum median IL-27 concentration was significantly higher in patients with single-lobe involvement than in those with multi-lobe involvement (P = 0.03) and in those with -964A/A genotypes than in those with -964A/G or -964G/G genotypes (P = 0.02). CONCLUSIONS In terms of serum IL-27 levels, the -964 A/A genotype may be associated with a protective role that prevents the intrapulmonary spread of PTB rather than its development.
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Affiliation(s)
- J Y Oh
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Korea University Guro Hospital, Seoul, Republic of Korea
| | - J K Sim
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Korea University Guro Hospital, Seoul, Republic of Korea
| | - W J Jung
- Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, Korea University Anam Hospital, Seoul, Republic of Korea
| | - K H Min
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Korea University Guro Hospital, Seoul, Republic of Korea
| | - E J Lee
- Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, Korea University Anam Hospital, Seoul, Republic of Korea
| | - G Y Hur
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Korea University Guro Hospital, Seoul, Republic of Korea
| | - S Y Lee
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Korea University Guro Hospital, Seoul, Republic of Korea
| | - S Y Lee
- Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, Korea University Anam Hospital, Seoul, Republic of Korea
| | - A M Kwon
- Division of Pulmonary, Sleep and Critical Care Medicine, Department of Internal Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea
| | - J H Kim
- Division of Pulmonary, Sleep and Critical Care Medicine, Department of Internal Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea
| | - C Shin
- Division of Pulmonary, Sleep and Critical Care Medicine, Department of Internal Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea
| | - J J Shim
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Korea University Guro Hospital, Seoul, Republic of Korea
| | - K H In
- Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, Korea University Anam Hospital, Seoul, Republic of Korea
| | - K H Kang
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Korea University Guro Hospital, Seoul, Republic of Korea
| | - S H Lee
- Division of Pulmonary, Sleep and Critical Care Medicine, Department of Internal Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea
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Oh JY, Kang MS, Yoon H, Choi HW, An BK, Shin EG, Kim YJ, Kim MJ, Kwon JH, Kwon YK. The embryo lethality of Escherichia coli isolates and its relationship to the presence of virulence-associated genes. Poult Sci 2012; 91:370-5. [PMID: 22252350 DOI: 10.3382/ps.2011-01807] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The aims of this study were to determine if the chicken embryo lethality assay and the presence of 9 virulence-associated genes of Escherichia coli were correlated and to discover which virulence genes contributed most to embryo lethality. We examined 58 E. coli strains isolated from visceral organs of chickens with colibacillosis for the presence of 9 virulence genes (fimC, tsh, fyuA, irp2, iucD, cvi/cva, iss, astA, and vat) by PCR. The gene FimC (type I fimbriae) was detected with the highest prevalence in 93.1% of the isolates, followed by iucD (67.24%), iss (58.62%), tsh (34.48%), cvi/cva (34.48%), fyuA (32.76%), astA (31.0%), irp2 (27.59%), and vat (17.24%). The embryo mortality ranged from 5 to 100%; however, most of the isolates were moderately or highly virulent. High positive correlations were observed between the presence of virulence genes and chicken embryo lethality. In addition, presence of the iucD (aerobactin) gene was the trait that best contributed to embryo mortality by using the multivariate model. These results suggest that expression frequency of these 9 virulence genes is associated with embryo mortality, and the gene that best predicted embryo mortality was iucD.
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Affiliation(s)
- J Y Oh
- Animal, Plant and Fisheries Quarantine and Inspection Agency, Anyang, Kyunggi, Korea
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Park JK, Kim HS, Uh KJ, Choi KH, Kim HM, Lee DK, Oh JY, Lee CK. 215 COMPARATIVE ANALYSIS OF PORCINE PLURIPOTENT CELL LINES DERIVED FROM SOMATIC CELLS AND VARIOUS EMBRYONIC ORIGINS. Reprod Fertil Dev 2012. [DOI: 10.1071/rdv24n1ab215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Since pluripotent cells were first derived from the inner cell mass (ICM) of mouse blastocysts, tremendous efforts have been made to establish embryonic stem cell (ESC) lines in several domestic species including the pig; however, authentic porcine ESCs have not yet been established. It has proven difficult to derive pluripotent cells of naïve state that represents full pluripotency, due to the frequent occurrence of spontaneous differentiation into an EpiSC-like state during culture in pigs. We have been able to derive EpiSC-like porcine embryonic stem cell (pESC) lines of a differentiated non-ES cell state from blastocyst stage porcine embryos of various origins, including in vitro fertilized (IVF), in vivo derived, IVF aggregated and parthenogenetic embryos. In addition, we have generated induced pluripotent stem cells (piPSCs) via plasmid transfection of reprogramming factors (Oct4, Sox2, Klf4 and c-Myc) into porcine fibroblast cells. In this study, we analysed characteristics such as marker expression, pluripotency and the X chromosome inactivation (XCI) status of our EpiSC-like pESC lines along with our piPSC line. Our results show that these cell lines demonstrate the expression of genes associated with the Activin/Nodal and FGF2 pathways along with the expression of pluripotent markers Oct4, Sox2, Nanog, SSEA4, TRA 1-60 and TRA 1-81. Furthermore all of these cell lines showed in vitro differentiation potential; female XCI activity and a normal karyotype. Here we provide preliminary results that suggest that, as a nonpermissive species, the porcine species undergoes reprogramming into a primed state during the establishment of pluripotent stem cell lines.
This work was supported by the BioGreen 21 Program (#20070401034031, PJ0081382011), Rural Development Administration, Republic of Korea.
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Oh JY, Kang MS, Kim JM, An BK, Song EA, Kim JY, Shin EG, Kim MJ, Kwon JH, Kwon YK. Characterization of Escherichia coli isolates from laying hens with colibacillosis on 2 commercial egg-producing farms in Korea. Poult Sci 2011; 90:1948-54. [PMID: 21844259 DOI: 10.3382/ps.2011-01509] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The present study reports on layer chickens with colibacillosis in 2 commercial egg-producing farms (referred to as farm A and farm B, which were managed by the same owner and were about 1 km apart) in the middle region of the Korean peninsula. The 2 flocks were infected at the initiation of egg laying. They were characterized by no previous clinical signs but sudden mortality (2.7-4.0%), with severe lesions of septicemia and fibrinous polyserositis. Escherichia coli was isolated from the lesions of the infected birds. Serotyping tests identified isolates that belonged to somatic groups O1 (12/17), O46 (2/17), O78 (1/17), and O84 (1/17) or that were unidentified (1/17). Thirteen of 17 E. coli isolates (76.4%) obtained from 11 birds in the 2 flocks showed similar pulsed-field gel electrophoresis patterns that were arbitrarily designated as pattern A. The isolates had high frequencies of putative virulence genes including 100% [fimC (type 1 fimbriae), iucD (aerobactin synthesis), and iss (increased serum survival)], 94.1% [cva/cvi (structural genes of colicin V operon) and vat (vacuolating autotransporter toxin)], 88.2% [irp2, iron-repressible protein (yersinia bactin) synthesis, and fyuA, ferric yersinia uptake], and 82.3% [tsh (temperature-sensitive hemagglutinin)]; astA (encoding a heat-stable cytotoxin associated with enteroaggregative E. coli) was not associated with the enteric disorder. These data suggest that all chickens with colibacillosis on farms A and B were likely infected by E. coli strains that are highly pathogenic in avian species.
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Affiliation(s)
- J Y Oh
- National Veterinary Research and Quarantine Service, Anyang, Kyunggi 430-824, Korea
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Abstract
We admixed cultured porcine keratocytes or corneal endothelial cells in the presence of human sera or peripheral blood mononuclear cells (PBMCs) for 4 to 72 hours to investigate their immune-related susceptibilities to xeno-related rejection. We evaluated complement deposition at 48 hours by flow cytometry after staining with the C3 anti-goat cy3 antibody. The inhibition of proliferation of porcine corneal cells by human sera was examined using the 3-[4,5-dimethy/thiazol-2,5-dephenyl tetrazolium bromide (MTT) assay over 24 to 72 hours. The amount of 51chromium (Cr)-release was estimated after a reaction between the porcine cells and human PBMCs for 4 hours. There was greater C3 deposition in keratocytes (60.2%) than in endothelial cells (26.9%; P = .05, Mann-Whitney U test). Both keratocytes and endothelial cells showed significant levels of proliferative inhibition over a period of 72 hours. The number of 51Cr-release cells on interleukin-2 addition was significantly higher among keratocytes (88.0%) than endothelial cells (51.4%) at a 1:100 target:effector ratio (P = .04, Mann-Whitney U test). Our present data suggested that porcine keratocytes might be key target cells in xeno-related rejections when the porcine cornea is transplanted to primates.
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Affiliation(s)
- M K Kim
- Department of Ophthalmology, College of Medicine, Seoul National University, Seoul, Korea
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Affiliation(s)
- H-S Jeong
- Department of Neurology, Chungnam University Hospitals 640, Daesa-dong, Jung-gu, Daejeon, 301-721, Korea
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Oh JY, Lim S, Kim DJ, Kim NH, Kim DJ, Moon SD, Jang HC, Cho YM, Song KH, Park KS. The diagnosis of diabetes mellitus in Korea: a pooled analysis of four community-based cohort studies. Diabet Med 2007; 24:217-8. [PMID: 17257287 DOI: 10.1111/j.1464-5491.2007.02051.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kim JH, Oh JY, Park BH, Lee DE, Kim JS, Park HE, Roh MS, Je JE, Yoon JH, Thorne SH, Kirn D, Hwang TH. Systemic armed oncolytic and immunologic therapy for cancer with JX-594, a targeted poxvirus expressing GM-CSF. Mol Ther 2006; 14:361-70. [PMID: 16905462 DOI: 10.1016/j.ymthe.2006.05.008] [Citation(s) in RCA: 230] [Impact Index Per Article: 12.8] [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: 03/09/2006] [Revised: 05/16/2006] [Accepted: 05/16/2006] [Indexed: 12/17/2022] Open
Abstract
Targeted oncolytic viruses and immunostimulatory therapeutics are being developed as novel cancer treatment platforms. These approaches can be combined through the expression of immunostimulatory cytokines from targeted viruses, including adenoviruses and herpesviruses. Although intratumoral injection of such viruses has been associated with tumor growth inhibition, eradication of distant metastases was not reported. The major limitations for this approach to date have been (1) inefficient intravenous virus delivery to tumors and (2) the lack of predictive, immunocompetent preclinical models. To overcome these hurdles, we developed JX-594, a targeted, thymidine kinase(-) vaccinia virus expressing human GM-CSF (hGM-CSF), for intravenous (i.v.) delivery. We evaluated two immunocompetent liver tumor models: a rabbit model with reproducible, time-dependent metastases to the lungs and a carcinogen-induced rat liver cancer model. Intravenous JX-594 was well tolerated and had highly significant efficacy, including complete responses, against intrahepatic primary tumors in both models. In addition, whereas lung metastases developed in all control rabbits, none of the i.v. JX-594-treated rabbits developed detectable metastases. Tumor-specific virus replication and gene expression, systemically detectable levels of hGM-CSF, and tumor-infiltrating CTLs were also demonstrated. JX-594 holds promise as an i.v.-delivered, targeted virotherapeutic. These two tumor models hold promise for the optimization of this approach.
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Affiliation(s)
- J H Kim
- Department of Pharmacology and MRCCMT, Dong-A University Medical College, Busan 604-714, South Korea
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Abstract
PURPOSE To investigate the effect of intracameral injection of triamcinolone acetonide on the corneal endothelium in rabbit eyes. METHODS Triamcinolone acetonide (40 mg/ml, 0.2 cm3) after filtering and resuspension in balanced salt solution (BSS) was injected intracamerally for 3 min into 10 rabbit eyes and irrigated with 5 cm(3) of BSS. Triamcinolone without resuspension and BSS were injected, respectively, into five rabbit eyes. Endothelial toxicity was evaluated and compared by measurements of endothelial cell counts and central corneal thickness. The endothelial viability was determined using vital staining with alizarin red and trypan blue at 2 h after injection. The scanning electron microscopy (SEM) was performed in one cornea from each group. RESULTS Endothelial cell counts and central corneal thickness following intracameral injection of triamcinolone acetonide did not significantly change when compared to controls. The mean percentage of viable endothelial cells was 99.50, 99.52, and 99.49% in the resuspended triamcinolone group, triamcinolone without resuspension group, and BSS group, respectively (P=0.46, Kruskall-Wallis test). But SEM showed reduced microvilli of endothelial surface in an eye of the triamcinolone without resuspension group. CONCLUSIONS The intracameral injection of triamcinolone acetonide did not induce a significant visible change of endothelium in rabbit eyes. However, ultrastructural villi changes observed suggest a possibility of microstructural damages in endothelium with triamcinolone acetonide injection when used without filtering and resuspension.
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Affiliation(s)
- J Y Oh
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul Artificial Eye Center, Seoul National University Hospital Clinical Research Institute, Seoul, Korea
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Abstract
PURPOSE Few reports have included large numbers of exotropia patients. Thus, we undertook this study to perform a survival analysis of over 350 patients with exotropia and to determine which factors might affect the outcome of exotropia surgery. METHODS The clinical records of 365 patients who underwent exotropia surgery by one surgeon were retrospectively reviewed. Preoperative patient characteristics, surgical procedures performed, and early postoperative ocular alignment were evaluated as potential risk factors of surgical outcome using survival analysis. RESULTS The estimated median time from surgery to recurrence was 48.3 months. None of the characteristics or procedures were found to be significantly associated with surgical outcome. The likelihood of a good postoperative surgical outcome was highest with an initial postoperative alignment of more than 10 prism diopters of esotropia (P<0.001). CONCLUSIONS Early postoperative overcorrection was the only predictor of a successful long-term outcome after exotropia surgery.
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Affiliation(s)
- J Y Oh
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Republic of Korea
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Abstract
Pulmonary tuberculomas are well-circumscribed masses caused by Mycobacterium tuberculosis. However, the response of tuberculomas to anti-tuberculous (TB) treatment has not been well defined as yet. The response of pulmonary tuberculomas to anti-TB treatment was retrospectively reviewed in 45 patients diagnosed between January 1997 and December 2001. The areas of pulmonary tuberculomas were estimated by calculating products of the longest and their perpendicular short diameters on chest radiographs. The response to anti-TB treatment was categorised as "decreased" (> 25% reduction in area versus its initial area), "increased" (> 251% increase) and "no change" (the remainder). The mean of treatment duration was 11.5 +/- 3.6 months. Three months after treatment, 18 patients (40.0%) were categorised as decreased, 25 (55.6%) as no change and two (4.4%) as increased. Twelve months after treatment, out of 42 patients available for chest radiographs, 32 patients (76.2%) were categorised as decreased, nine (21.4%) as no change and one patient (2.4%) as increased. At the last follow-up (mean follow-up 27.0 +/- 10.2 months), 37 patients (82.2%) were categorised as decreased. The majority of pulmonary tuberculomas were decreased by anti-tuberculosis treatment during and even after treatment, although a transient enlargement during the early period of treatment was observed infrequently.
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Affiliation(s)
- H S Lee
- Division of Respiratory and Critical Care Medicine, Dept of Internal Medicine and Lung Institute of Medical Research Centre, Seoul National University College of Medicine, Seoul, Republic of Korea
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Park JC, Lee JC, Oh JY, Jeong YW, Cho JW, Joo HS, Lee WK, Lee WB. Antibiotic selective pressure for the maintenance of antibiotic resistant genes in coliform bacteria isolated from the aquatic environment. Water Sci Technol 2003; 47:249-253. [PMID: 12639037] [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] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Coliform bacteria isolated from the aquatic environment were investigated for antibiotic susceptibility and detailed structures of class 1 integrons. A high proportion of isolates were found to be resistant to sulfamethoxazole, aminoglycosides, and beta-lactams. The 750 (53.6%) isolates were resistant to one or more of the antibiotics tested out of 1,400 coliform bacteria. Based on the MIC of antibiotics and antibiogram, 150 isolates were selected and further studied for class 1 integrons. The intI1 gene was found in 36 (24.0%) of the 150 isolates. Twelve isolates carried the gene cassettes responsible for antibiotic resistance, while no gene cassettes were found in 24 isolates. Seven different genes, dfrA5, dfrA7, dfrA12, dfrA17, aaA2, aaA5, and aad(3'), were detected in gene cassettes. The dfrA and aad genes located on class 1 integrons were responsible for resistance to trimethoprim and aminoglycosides. The remaining 24 coliform bacteria had the incomplete or non-functional class 1 integrons. These results indicated that antibiotic selective pressures may play an important role to maintain gene cassettes of class 1 integrons and in the absence of sustained antibiotic pressures, such as the aquatic environment, coliform bacteria may carry empty or non-functional class 1 integrons.
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Affiliation(s)
- J C Park
- Dept of Microbiology, Seonam University, Chunpook, 590-711, Korea.
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17
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Cho JW, Jeong YW, Kim KS, Oh JY, Park JC, Lee JC, Baek WK, Suh SI, Suh MH. p21(WAF1) is associated with CDK2 and CDK4 protein during HL-60 cell differentiation by TPA treatment. Cell Prolif 2001; 34:267-74. [PMID: 11591175 PMCID: PMC6495204 DOI: 10.1046/j.0960-7722.2001.00208.x] [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] [Indexed: 11/20/2022] Open
Abstract
TPA-treated HL-60 cells are mainly arrested in G1 by p21(WAF1) accumulation. We investigate the downstream changes following such accumulation. Increased p21(WAF1) is associated with CDK2 and CDK4. pRb is dephosphorylated in the presence of p21-CDK2/4 complexes, and the Rb-E2F1 complex increases after TPA treatment, whereas the Rb-HDAC1 complex decreases slightly. Our results suggest that increased p21(WAF1) is associated with CDK2/4, and that these complexes induce pRb dephosphorylation. In turn, hypophosphorylated pRb are mainly complexed with E2F1, but HDAC1 appears not to be a key component in this process.
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Affiliation(s)
- J W Cho
- Department of Microbiology, College of Medicine, Seonam University, Kwangchi-Dong 720, Namwon, Chunpook 590-711, Korea
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18
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Lee MJ, Oh JY, Park HT, Uhlinger DJ, Kwak JY. Enhancement of phospholipase D activity by overexpression of amyloid precursor protein in P19 mouse embryonic carcinoma cells. Neurosci Lett 2001; 315:159-63. [PMID: 11716987 DOI: 10.1016/s0304-3940(01)02339-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It has been shown that phospholipase D (PLD) activity is stimulated by the beta-amyloid protein in neuronal cells. The aim of this study was to determine whether overexpression of the amyloid precursor protein (APP) affects the activity and the level of PLD expression in P19 embryonic carcinoma cells. We observed that the unstimulated basal PLD activity was higher in wild-type APP(695)-transfected cells than in non-transfected control cells. The protein kinase C (PKC) activator, phorbol 12-myristate 13-acetate (PMA), has been shown to activate PLD. PMA-stimulated PLD activity was 3-fold higher in the APP overexpressing cells than in the control cells. P19 cells express two distinct PLD isozymes, PLD1 and PLD2. The level of PLD2 expression was increased by APP overexpression. Although the PKC inhibitor, GF109203X, inhibited PMA-stimulated PLD activity, it did not affect the high basal PLD activity induced by APP overexpression. Neuronal differentiation of the P19 cells by retinoic acid did not affect the basal or PMA stimulated-PLD activity. Interestingly, APP overexpression in the differentiated P19 cells also led to an increase in PLD activity. The PLD activity of the P19 cells is apparently regulated by amyloid protein through both PKC-dependent and -independent mechanisms.
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Affiliation(s)
- M J Lee
- Department of Biochemistry, Dong-A University College of Medicine and Dong-A University Institute of Medical Science, Seo-Ku, Pusan 602-103, South Korea
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Abstract
Epithelial cell death induced by Acinetobacter baumannii infection was investigated using in vitro assays. Eight hours after live A. baumannii infection, HeLa cells exhibited detachment from the dish, rounding morphologies, high proportions of trypan blue-positive cells and extensive DNA breakdown with faint apoptotic banding, which is indicative of cells undergoing apoptosis. The enzymatic activity of caspase-3 was increased in cells as early as 2 h after infection. In addition, apoptosis of HeLa cells was induced by treatment with bacterial culture filtrates but not with formalin-killed bacteria. These results indicate that A. baumannii infection triggers apoptosis in HeLa cells through caspase-3 activation.
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Affiliation(s)
- J C Lee
- Department of Microbiology, College of Medicine, Seonam University, Namwon, Chunpook, Korea.
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20
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Abstract
Association between apolipoprotein E (apoE) gene polymorphism and lipid levels was studied in 164 nondiabetic first-degree relatives of persons with diabetes and 962 nondiabetic persons with no family history of diabetes. Sex-specific genotypic distribution of apoE polymorphism did not differ between persons with and without a family history of diabetes. In first-degree relatives, lipid levels did not differ among persons with apoE2 (E2/2, E2/3), apoE3/3, and apoE4 (E4/4, E3/4) after adjusting for age, waist circumference, smoking, and alcohol and estrogen use. In persons without a family history of diabetes, both men (p<0.01) and women (p<0.001) with apoE2 showed lower levels of total and low density lipoprotein cholesterol compared with persons with apoE3/3 and apoE4. In women with a family history of diabetes, persons with apoE4 had larger waist circumference (p<0.05). ApoE2 allele is associated with more favorable levels of total and low density lipoprotein cholesterol in men and women without a family history of diabetes. ApoE4 allele is associated with obesity independent of dyslipidemia in women but not men with a family history of diabetes. ApoE polymorphism is not associated with lipids in men or women with a family history of diabetes.
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Affiliation(s)
- J Y Oh
- Division of Epidemiology, Department of Family and Preventive Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0607, USA
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Lee JC, Oh JY, Cho JW, Park JC, Kim JM, Seol SY, Cho DT. The prevalence of trimethoprim-resistance-conferring dihydrofolate reductase genes in urinary isolates of Escherichia coli in Korea. J Antimicrob Chemother 2001; 47:599-604. [PMID: 11328770 DOI: 10.1093/jac/47.5.599] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
One-hundred and twenty-two urinary isolates of Escherichia coli were studied for trimethoprim resistance. Seventy-seven (63.1%) of the 122 isolates were found to be resistant to trimethoprim. Of the 77 trimethoprim-resistant isolates, 75 dfr genes were detected in 72 isolates as follows: the dfrA17 gene was the most prevalent, being found in 27 isolates, followed by dfrA12 in 26, dfrA1 in 15, dfrA5 in four and dfrA7 in three. Southern blot and PCR mapping analysis revealed that all of the dfrA17, dfrA12, dfrA5 and dfrA7 genes were located on class 1 integrons. The dfrA1 gene inserted as a gene cassette in class 1 integrons was found in 10 of 15 isolates, and the intI2 gene of Tn7 was detected in two out of five isolates. In conjugation experiments, the dfr genes inserted in class 1 integrons were transferred to a recipient E. coli in 32 (42.7%) of the 75 dfr genes. In conclusion, the dfrA17 and dfrA12 genes were the most prevalent genes responsible for trimethoprim resistance in urinary tract isolates of E. coli from Korea and the dfr genes inserted in integrons are more widespread than those that are not related to gene cassettes.
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Affiliation(s)
- J C Lee
- Department of Microbiology, College of Medicine, Seonam University, Namwon, Chunpook 590-711, Korea.
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Song J, Oh JY, Sung YA, Pak YK, Park KS, Lee HK. Peripheral blood mitochondrial DNA content is related to insulin sensitivity in offspring of type 2 diabetic patients. Diabetes Care 2001; 24:865-9. [PMID: 11347745 DOI: 10.2337/diacare.24.5.865] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.6] [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: 02/03/2023]
Abstract
OBJECTIVE To investigate whether the peripheral blood mtDNA (pb-mtDNA) content is decreased and linked to insulin resistance in the offspring of type 2 diabetic patients. RESEARCH DESIGN AND METHODS A total of 82 offspring of type 2 diabetic patients and 52 age-, sex-, and BMI-matched normal subjects from the Mokdong, Korea, population were selected for this study by stratified, randomized sampling. Of the offspring of diabetic patients, 52 had normal glucose tolerance (NGT), 21 had impaired glucose tolerance (IGT), and 9 had newly diagnosed type 2 diabetes. The pb-mtDNA content was measured by real-time polymerase chain reaction with a mitochondria-specific fluorescent probe, normalized by a nuclear DNA, 285 rRNA gene. The associations between pb-mtDNA content and several parameters of insulin resistance were studied. RESULTS The pb-mtDNA contents tended to be lower in the 82 offspring of type 2 diabetic patients (1,084.7 +/- 62.6 vs. 1,304.0 +/- 99.2 in the offspring and control subjects, respectively, P = 0.051) and was significantly lower in the combined NGT and IGT offspring group (NGT+IGT, 1,068.0 +/- 67.8, P < 0.05) than in the control subjects. In NGT+IGT offspring, the pb-mtDNA content was significantly correlated with logarithmically transformed insulin sensitivity (r = 0.253, P < 0.05) and was the main predictor of insulin sensitivity. CONCLUSIONS Quantitative mtDNA status might be a hereditary factor associated with type 2 diabetes and could serve as an indicator for insulin sensitivity.
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Affiliation(s)
- J Song
- Department of Biomedical Sciences, Korean National Institute Health, Seoul
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Abstract
Eighty-eight strains of Shigella sonnei isolated in Korea during the period 1980 to 1999 were tested for susceptibility to 13 antimicrobial agents. S. sonnei isolates demonstrated high frequencies of resistance to sulfamethoxazole (97.7%), tetracycline (96.6%), and trimethoprim (95.5%). S. sonnei isolates from the 1990s were more resistant to nalidixic acid than isolates from the 1980s (100 vs 7.7%), while isolates from the 1990s were more susceptible to chloramphenicol than isolates from the 1980s (0 vs 100%). Ampicillin-resistant S. sonnei isolates produced the TEM-1 beta-lactamase with a pI of 5.4. The TEM-1 gene was located on conjugally transferable plasmids in the majority of isolates. S. sonnei isolates were all susceptible to cefotaxime, cefoxitin, ceftazidime, ciprofloxacin, and norfloxacin. These results indicate that cephalosporins and quinolones may be alternative antibiotics for the treatment of S. sonnei infections in Korea.
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Affiliation(s)
- J C Lee
- Department of Microbiology, College of Medicine, Seonam University, Namwon, Chunpook, Korea.
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Oh JY, Rosow E, Bronzino J, Enderle J, Eisenfeld L. The design and development of a biosensor to measure the concentration of meconium in amniotic fluid. Biomed Instrum Technol 2001; 35:46-56. [PMID: 11233308] [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: 02/19/2023]
Abstract
Meconium aspiration syndrome occurs in 0.2% to 1% of all deliveries and has a mortality rate as high as 18%. The disease is responsible for 2% of all perinatal deaths. Meconium may be classified as being thick or thin, but this assessment is normally performed visually by clinicians. A "meconiumcrit" analysis has been developed to objectively define the concentration of meconium. However, this analysis does not provide real-time continuous readings. This study focused on the design and development of a sensor to provide an objective, continuous, real-time assessment of meconium thickness. Meconium has an absorption spectrum centered at 410 nm and observes Beer's law. Blue light centered at 430 nm was delivered through meconium solutions, and a photodiode translated the strength of the incoming light into a voltage. This voltage was analyzed by a microcontroller to determine the concentration of meconium.
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Affiliation(s)
- J Y Oh
- Raytheon Systems Company, El Segundo, CA, USA
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Seong IS, Oh JY, Lee JW, Tanaka K, Chung CH. The HslU ATPase acts as a molecular chaperone in prevention of aggregation of SulA, an inhibitor of cell division in Escherichia coli. FEBS Lett 2000; 477:224-9. [PMID: 10908725 DOI: 10.1016/s0014-5793(00)01808-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
HslVU is an ATP-dependent protease consisting of two multimeric components: the HslU ATPase and the HslV peptidase. SulA, which is an inhibitor of cell division and has high tendency of aggregation, is degraded by HslVU protease. Here we show that HslU plays a role not only as a regulatory component for the HslV-mediated proteolysis but also as a molecular chaperone. Purified HslU prevented aggregation of SulA in a concentration-dependent fashion. This chaperone activity required oligomerization of HslU subunits, which could be achieved by ATP-binding or in the presence of high HslU protein concentrations. hsl mutation reduced the SulA-mediated inhibition of cell growth and this effect could be reversed upon overproduction of HslU, suggesting that HslU promotes the ability of SulA to block cell growth through its chaperone function. Thus, HslU appears to have two antagonistic functions: one as a chaperone for promotion of the ability of SulA in cell growth inhibition by preventing SulA aggregation and the other as the regulatory component for elimination of SulA by supporting the HslV-mediated degradation.
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Affiliation(s)
- I S Seong
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 151-742, South Korea
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26
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Abstract
PURPOSE Choroidal neovascularization (CNV) is responsible for most cases of severe visual loss in age-related macular degeneration. Recently, the possibility of gene therapy has been proposed for the treatment of CNV. The purpose of this study was to examine the feasibility of ex vivo and in situ gene therapy approaches for CNV. DESIGN Experimental study. METHODS Human retinal pigment epithelial (RPE) cells were transduced with a retroviral vector coding for beta-galactosidase. Transduced cells were grown on type II collagen sheets and transplanted under the retina of 20 rabbits. Animals were observed for 3 to 56 days, and transplanted cells were examined histologically and with X-gal staining. Bovine choroidal endothelial cells (CEC) were transduced with retroviral vectors coding for tissue inhibitor of metalloproteinase-2 (TIMP-2) or control vector. Production of TIMP-2 by transduced cells was determined by immunohistochemical analysis and enzyme-linked immunosorbent assay. Effect of transduction on in vitro proliferation, migration, and tube formation was examined in response to vascular endothelial growth factor (VEGF). Four CNV lesions were induced in one cynomolgus monkey by laser photocoagulation. Two days later, retroviral vector coding for TIMP-2 or control vector was injected into the subretinal space overlying the CNV lesions. The monkey was observed for 12 weeks using fluorescein angiography. RESULTS Transplantation of transduced RPE cells was technically achieved in 10 of 20 animals. In these animals, RPE cells at the site of transplantation formed a monolayer and expressed beta-galactosidase for 14 days. beta-Galactosidase-positive cells were not identified at 56 days. Choroidal endothelial cells transduced with TIMP-2 secrete TIMP-2 into the media and show decreased migration and tube formation in vitro. In the in vivo monkey model, the control CNV lesions (n = 2) showed prominent leakage, whereas the experimental lesions (n = 2) showed minimal hyperfluorescence. CONCLUSIONS Retrovirally transduced RPE cells survive in the subretinal space for at least 14 days and continue to express the gene product coded for by the vector. Choroidal endothelial cells retrovirally transduced for TIMP-2 produce TIMP-2 in vitro and show decreased angiogenic responses in vitro in response to VEGF. A preliminary study attempting in situ delivery of TIMP-2 vector to CNV lesions in a monkey eye supports the feasibility of this approach and encourages further study.
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Affiliation(s)
- T Murata
- Doheny Eye Institute and Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California 90033, USA
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Lee JH, Oh JY, Kim DM. MMA/MPEOMA copolymers as coating materials for improved blood compatibility: protein adsorption study. J Mater Sci Mater Med 1999; 10:629-634. [PMID: 15347977 DOI: 10.1023/a:1008987724749] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Surface-induced thrombosis remains one of the main problems in the development of blood-contacting devices. When a foreign surface comes in contact with blood, the initial blood response is adsorption of blood proteins, followed by platelet adhesion and activation, leading to thrombus formation. A particularly effective polymer for the prevention of protein adsorption and platelet adhesion appears to be polyethylene oxide (PEO). In this study, water-insoluble copolymers of methyl methacrylate (MMA) and methoxy PEO monomethacrylates (MPEOMA) with different PEO molecular weights (200, 400, and 1000) and monomer composition were synthesized and characterized by gel permeation chromatography and 1H-nuclear magnetic resonance spectroscopy. The synthesized copolymers were coated on glass slides by a spin coating method to prepare PEO-rich surfaces as blood-compatible surfaces. The surface properties of the copolymers and their interaction with blood proteins (albumin, gamma-globulin, fibrinogen, and plasma proteins) were investigated by the measurement of water contact angles and by electron spectroscopy for chemical analysis, respectively. It was observed that the protein adsorption on the copolymer surfaces decreased with increasing PEO molecular weight and MPEOMA content in the copolymers. The copolymers with long PEO chains in MPEOMA (MMA/MPEO1000MA copolymers) were effective in preventing protein adsorption, even though their MPEOMA content was less than the copolymers with shorter PEO chains.
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Affiliation(s)
- J H Lee
- Department of Polymer Science and Engineering, Hannam University, 133 Ojeong Dong, Daedeog Ku, Taejon 306-791, Korea
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28
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Abstract
HslVU is an ATP-dependent protease consisting of two multimeric components, the HslU ATPase and the HslV peptidase. To gain an insight into the role of HslVU in regulation of cell division, the reconstituted enzyme was incubated with SulA, an inhibitor of cell division in Escherichia coli, or its fusion protein with maltose binding protein (MBP). HslVU degraded both proteins upon incubation with ATP but not with its nonhydrolyzable analog, ATPgammaS, indicating that the degradation of SulA requires ATP hydrolysis. The pulse-chase experiment using an antibody raised against MBP-SulA revealed that the stability of SulA increased in hsl mutants and further increased in lon/hsl double mutants, indicating that SulA is an in vivo substrate of HslVU as well as of protease La (Lon). These results suggest that HslVU in addition to Lon plays an important role in regulation of cell division through degradation of SulA.
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Affiliation(s)
- I S Seong
- Department of Molecular Biology and Research Center for Cell Differentiation, College of Natural Sciences, Seoul National University, South Korea
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Abstract
The yeast ROK1 gene has been initially identified as a high copy plasmid suppressor of the kem1 null mutation and implicated in microtubule-mediated functions. Based on the deduced amino acid sequence of the ROK1 gene, Rok1p has been classified in the DEAD protein family of ATP-dependent RNA helicases. A subsequent report has suggested that Rok1p is required for rRNA processing. We report here the first study on the biochemical activity associated with Rok1p. The MBP-Rok1 hybrid protein was synthesized in Escherichia coli and purified by amylose affinity column and ion exchange chromatography. Rok1p has ATP hydrolysis activity. The significance of the conserved ATPase domains was addressed by generating a series of amino acid substitution mutations in these domains. Both in vivo lethality tests of the mutations and biochemical characterization of the mutant proteins suggest that ATP hydrolysis activity of Rok1p is essential for ROK1 function. The ATPase activity of Rok1p appears to be independent of single-stranded RNA. Furthermore, replacement of the first Arg in the HRIGR domain, the known RNA-binding domain, with Thr, Ile or Lys has no detectable effect on in vivo ROK1 function. The lack of RNA dependency and some of the mutational phenotypes of ROK1 differentiate this gene from other members of the family.
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Affiliation(s)
- J Y Oh
- Department of Microbiology, College of Natural Sciences, Chungnam National University, Taejeon 305-764, Korea
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Oh JY, Eun YM, Yoo SJ, Seol JH, Seong IS, Lee CS, Chung CH. LonR9 carrying a single Glu614 to Lys mutation inhibits the ATP-dependent protease La (Lon) by forming mixed oligomeric complexes. Biochem Biophys Res Commun 1998; 250:32-5. [PMID: 9735326 DOI: 10.1006/bbrc.1998.9252] [Citation(s) in RCA: 7] [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
An unusual lon mutation (called lonR9) is dominant over the wild-type gene, which encodes the ATP-dependent protease La (Lon) in Escherichia coli, when present in multicopy plasmids. Here, we cloned and sequenced lonR9, and showed that the mutant gene carries a single point mutation in its open reading frame, which leads to replacement of Glu614 by Lys. The LonR9 protein and its poly-His-tagged form were purified to apparent homogeneity. Both of the purified proteins were capable of inhibiting the ATP-dependent proteolysis and the protein-activated ATP hydrolysis by protease La. Furthermore, the His-tagged LonR9 protein was found to form mixed oligomeric complexes with protease La, upon analysis by chromatography on a metal-chelating column. These results suggest that the phenotypic dominance of the lonR9 mutant is due to the formation of mixed oligomeric complexes between LonR9 and protease La, in which the defective components prevent the function of the wild-type subunits.
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Affiliation(s)
- J Y Oh
- College of Natural Sciences, Seoul National University, Seoul, 151-742, Korea
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Abstract
Human annexin I is a member of the annexin family of calcium-dependent phospholipid binding proteins. The structure of an N-terminally truncated human annexin I (delta-annexin I) and its interactions with Ca2+, Mg2+, and ATP were studied at the atomic level using nuclear magnetic resonance (NMR) spectroscopy. Since delta-annexin I is a large protein, with a molecular weight of 35 kDa, a site-specific (carbonyl-13C, amide-15N) labeling technique was used to determine the interaction sites of delta-annexin I with Ca2+, Mg2+, and ATP. The 13C NMR study focused on the carbonyl carbon resonances of the histidine residues of delta-annexin I. We found that ATP binds to delta-annexin I, and that the ATP binding site is located in the 1-domain of annexin I. We also found that histidine-52 is involved in that site, and that the binding ratio of ATP to delta-annexin I is 1:1.
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Affiliation(s)
- H Y Han
- Department of Pharmacy, Seoul National University, South Korea
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Choi JH, Oh JY, Ryu SK, Kim SJ, Lee NY, Kim YS, Yi SY, Shim KS, Han WS. Detection of epidermal growth factor receptor in the serum of gastric carcinoma patients. Cancer 1997; 79:1879-83. [PMID: 9149012] [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: 02/04/2023]
Abstract
BACKGROUND Epidermal growth factor receptor (EGFR) is overexpressed in various malignancies including carcinoma of the breast, lung, esophagus, cervix, and stomach. In patients with gastric carcinoma, its overexpression may be associated with advanced stage and poor prognosis. METHODS The levels of EGFR extracellular domain were determined in serum from 40 gastric carcinoma patients using enzyme-linked immunosorbent assay. Serum EGFR levels were measured in 5 Stage I, 2 Stage II, 6 Stage III, and 27 Stage IV patients, and 29 healthy controls. RESULTS The mean serum level for EGFR in the gastric carcinoma patients was significantly elevated compared with that of healthy controls (681 +/- 226 fmol/mL vs. 440 +/- 46 fmol/mL; P < 0.0001). Thirty-one patients with gastric carcinoma (77.5%) showed elevated EGFR levels above a cutoff value of 532 fmol/mL (defined as 2 standard deviations above the mean of the controls). No significant association was noted between positivity of EGFR and gender, age, stage, and tumor differentiation. CONCLUSIONS The authors believe that serum EGFR could be useful as a tumor marker of gastric carcinoma for diagnosis, prognosis, follow-up after surgery, and monitoring patient response to chemotherapy.
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Affiliation(s)
- J H Choi
- Department of Hematology-Oncology, School of Medicine, Ajou University, Suwon, Korea
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Abstract
Colorectal cancer with bone metastasis as initial manifestation is a very rare event. We have reported a case of rectal cancer presenting with sternal metastasis. A 30 year-old man was evaluated due to pain in the sternal area with a bulging mass. History and physical examination did not suggest any specific disease. A radionuclide bone scan revealed increased uptake in the sternal area, right 6th rib, and sacrum. Microscopic examination of a biopsy specimen from the sternum showed metastatic adenocarcinoma. A barium enema and CT scan of the pelvis suggested carcinoma of the upper rectum. Adenocarcinoma of the rectosigmoid junction area was demonstrated by colonoscopic examination with biopsy. He received palliative transverse colostomy for obstruction without further treatment.
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Affiliation(s)
- J H Choi
- Department of Internal Medicine, Ewha Womans University College of Medicine, Seoul, Korea
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Abt AB, Oh JY, Huntington RA, Burkhart KK. Chinese herbal medicine induced acute renal failure. Arch Intern Med 1995; 155:211-212. [PMID: 7811132] [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] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A patient with acute interstitial nephritis secondary to ingestion of a Chinese herbal medicine adulterated with mefenamic acid is presented. Following hemodialysis and cessation of the medication the patient's renal function returned to normal.
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Affiliation(s)
- A B Abt
- Department of Pathology, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey
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Chi L, Friedrichs GS, Oh JY, Green AL, Lucchesi BR. Effect of Ado A1- and A2-receptor activation on ventricular fibrillation during hypoxia-reoxygenation. Am J Physiol 1994; 267:H1447-54. [PMID: 7943390 DOI: 10.1152/ajpheart.1994.267.4.h1447] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We examined the hypothesis that adenosine (Ado)-induced alterations in ventricular electrophysiology may contribute to arrhythmogenesis in a setting of myocardial hypoxia through activation of Ado A1 and A2 receptors in the rabbit isolated perfused heart. There was a 20% incidence of ventricular fibrillation (VF) in control hearts subjected to perfusion conditions of hypoxia and reoxygenation. The incidence of VF was increased to 50% in the presence of 1 microM Ado when hearts were exposed to hypoxia-reoxygenation. The incidence of VF was 20% when Ado was increased to 10 microM. Inhibition of the Ado A2 receptor with 3,7-dimethyl-l-propargylxanthine (DMPX; 10 microM) increased the incidence of VF to 100% when 10 microM Ado was added to the perfusion medium. The A1 antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 1 microM), attenuated (from 100% to 20%) VF induced by Ado + DMPX (10 microM each). The ventricular refractory period and monophasic action potential duration were determined in a separate group of hearts. Our findings indicate that 1) Ado A1-receptor stimulation facilitates VF by decreasing action potential duration and refractoriness in hearts subjected to hypoxia and reoxygenation and 2) the arrhythmogenic potential of Ado A1-receptor stimulation is modulated by simultaneous activation of the ventricular A2 Ado receptor.
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Affiliation(s)
- L Chi
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor 48109-0626
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Friedrichs GS, Chi L, Black SC, Manley PJ, Oh JY, Lucchesi BR. Antifibrillatory effects of ibutilide in the rabbit isolated heart: mediation via ATP-dependent potassium channels. J Pharmacol Exp Ther 1993; 266:1348-54. [PMID: 8371141] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
This study determined if ibutilide, a drug with class III activity, exhibited antifibrillatory effects in an isolated heart model of ventricular fibrillation (VF). Langendorff-perfused hearts were randomized among six groups. Group I (n = 9) served as the vehicle-treated control group. Groups II (n = 6), III (n = 10) and IV (n = 9) were pretreated with ibutilide 0.1; 1.0 or 3.0 microM, respectively. Ten minutes after perfusion in the presence of vehicle or ibutilide, hearts were perfused with the ATP-dependent potassium channel opener, pinacidil (1.25 microM) and subjected to a 12-min hypoxic period followed by 40 min of reoxygenation, or until the onset of VF. Groups V and VI were used to investigate electrophysiological effects of ibutilide (n = 12), as well as its chemical defibrillatory activity (n = 9), respectively. Additional experiments involved isometric tension recordings from canine atrial pectinate muscle exposed to increasing concentrations of pinacidil (3-300 microM) in the presence of ibutilide (3-30 microM). Ibutilide decreased the incidence of VF in a concentration-dependent manner; eight of nine control hearts developed VF vs. two of nine hearts (P = .018 chi 2) treated with 3.0 microM ibutilide. In atrial pectinate tissue, ibutilide attenuated the negative inotropic effect of pinacidil. An unexpected finding was the ability of ibutilide to achieve chemical defibrillation when added to the perfusion medium after the electrical induction of ventricular fibrillation in the isolated heart. The antifibrillatory effect of ibutilide may result from inhibition of the ATP-dependent potassium channel made susceptible to opening by pinacidil during hypoxia.
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Affiliation(s)
- G S Friedrichs
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor
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Abstract
Plasma glucosylceramide levels in eight patients with Gaucher's disease showed a 2 to 7-fold elevation over normal levels whereas erythrocyte glucosylceramide levels were within the normal range. The majority of the glucosylceramide elevation was associated with the low density lipoprotein fraction.
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