226
|
Holley WR, Mian IS, Park SJ, Rydberg B, Chatterjee A. A model for interphase chromosomes and evaluation of radiation-induced aberrations. Radiat Res 2002; 158:568-80. [PMID: 12385634 DOI: 10.1667/0033-7587(2002)158[0568:amfica]2.0.co;2] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We have developed a theoretical model for evaluating radiation-induced chromosomal exchanges by explicitly taking into account interphase (G(0)/G(1)) chromosome structure, nuclear organization of chromosomes, the production of double-strand breaks (DSBs), and the subsequent rejoinings in a faithful or unfaithful manner. Each of the 46 chromosomes for human lymphocytes (40 chromosomes for mouse lymphocytes) is modeled as a random polymer inside a spherical volume. The chromosome spheres are packed randomly inside a spherical nucleus with an allowed overlap controlled by a parameter Omega. The rejoining of DSBs is determined by a Monte Carlo procedure using a Gaussian proximity function with an interaction range parameter sigma. Values of Omega and sigma have been found which yield calculated results of interchromosomal aberration frequencies that agree with a wide range of experimental data. Our preferred solution is one with an interaction range of 0.5 microm coupled with a relatively small overlap parameter of 0.675 microm, which more or less confirms previous estimates. We have used our model with these parameter values and with resolution or detectability limits to calculate yields of translocations and dicentrics for human lymphocytes exposed to low-LET radiation that agree with experiments in the dose range 0.09 to 4 Gy. Five different experimental data sets have been compared with the theoretical results. Essentially all of the experimental data fall between theoretical curves corresponding to resolution limits of 1 Mbp and 20 Mbp, which may reflect the fact that different investigators use different limits for sensitivity or detectability. Translocation yields for mouse lymphocytes have also been calculated and are in good agreement with experimental data from 1 cGy to 10 cGy. There is also good agreement with recent data on complex aberrations. Our model is expected to be applicable to both low- and high-LET radiation, and we include a sample prediction of the yield of interchromosomal rejoining in the dose range 0.22 Gy to 2 Gy of 1000 MeV/nucleon iron particles. This dose range corresponds to average particle traversals per nucleus ranging from 1.0 to 9.12.
Collapse
|
227
|
Kadoya-Minegishi M, Park SJ, Sekiguchi M, Nishifuji K, Momoi Y, Iwasaki T. The use of fluorescein as a contrast medium to enhance intradermal skin tests in cats. Aust Vet J 2002; 80:702-3. [PMID: 12465831 DOI: 10.1111/j.1751-0813.2002.tb11305.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
228
|
Demers LM, Park SJ, Taton TA, Li Z, Mirkin CA. Orthogonal assembly of nanoparticle building blocks on dip-pen nanolithographically generated templates of DNA. Angew Chem Int Ed Engl 2002; 40:3071-3. [PMID: 12203653 DOI: 10.1002/1521-3773(20010817)40:16<3071::aid-anie3071>3.0.co;2-s] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2001] [Indexed: 12/25/2022]
Abstract
Nanoscale construction work with DNA: Dip-pen nanolithography (DPN) is used to generate nanostructures which can be subsequently functionalized with oligonucleotides a' and b' and used to assemble, in an orthogonal manner, gold nanoparticles (a, b in scheme) functionalized with sequences complementary to the DPN-generated structures.
Collapse
|
229
|
Kamimura D, Fu D, Matsuda Y, Atsumi T, Ohtani T, Park SJ, Ishihara K, Hirano T. Tyrosine 759 of the cytokine receptor gp130 is involved in Listeria monocytogenes susceptibility. Genes Immun 2002; 3:136-43. [PMID: 12070777 DOI: 10.1038/sj.gene.6363825] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2001] [Revised: 10/16/2001] [Accepted: 10/22/2001] [Indexed: 11/08/2022]
Abstract
Interleukin-6 family cytokines have been implicated in adaptive and innate immunity, hematopoiesis, and inflammation. This cytokine family shares a signal-transducing receptor subunit called gp130. gp130(F759/F759) knockin mice carry a point mutation at the SHP2-binding site of gp130 due to the replacement of tyrosine-759 (Y759 for human gp130) with phenylalanine (F). To explore the effect of this point mutation on the host response to bacterial infection, gp130(F759/F759) knockin mice were infected with Listeria monocytogenes. gp130(F759/F759) knockin mice began to die at 3 to 4 days post infection (p.i.) and showed higher mortality than did controls. Listeria titers at 3 days p.i. in the peritoneal cavity, spleen, and liver were significantly higher in gp130(F759/F759)knockin mice than in controls. Nitric oxide production, upregulation of the mRNA levels of a variety of cytokines, and listericidal activity in gp130(F759/F759) macrophages were unchanged. However, gp130(F759/F759) knockin mice displayed significantly lower levels of interferon (IFN)gamma in serum and in the culture supernatant from peritoneal exudate cells and splenocytes, in response to Listeria infection. These results suggest that the Y759 point mutation in gp130 attenuates the early phase of defense against Listeria infection, possibly owing to insufficient elevation of IFNgamma levels, and thus gp130 is a possible candidate gene for Listeria susceptibility.
Collapse
|
230
|
Kim BN, Bae LG, Kim MN, Park SJ, Woo JH, Ryu J, Kim YS. Risk factors for penicillin resistance and mortality in Korean adults with Streptococcus pneumoniae bacteremia. Eur J Clin Microbiol Infect Dis 2002; 21:35-42. [PMID: 11913499 DOI: 10.1007/s10096-001-0650-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A retrospective analysis was performed to measure the incidence of pneumococcal bacteremia and to identify risk factors for penicillin resistance and prognostic factors for outcome in adults. A total of 151 cases of pneumococcal bacteremia were identified from 149 adults during the period 1996-2000. The overall rate of penicillin resistance was 49%, ranging from 54.2% in 1996 to 48.5% in 2000 (P=0.93). Rates of resistance to ceftriaxone, clindamycin, erythromycin, and trimethoprim-sulfamethoxazole were 21.6%, 51%, 62%, and 44.7%, respectively. Multidrug resistance was documented in 47.7% of the cases. Penicillin resistance was significantly associated with solid tumor, biliary drainage catheter, and previous beta-lactam therapy in the univariate analysis. However, the associations were not as significant as independent risk factors in the multivariate analysis. Mortality was 23.8% and did not change significantly during the study period (P=0.06). Mortality rates in cases caused by penicillin-susceptible Streptococcus pneumoniae and penicillin-resistant Streptococcus pneumoniae were 23% and 24.7%, respectively (P=0.81). Mortality was not significantly influenced by penicillin resistance, even high-level resistance (24.4% vs. 20%; P=0.64). Multivariate analysis revealed that antineoplastic chemotherapy, respiratory failure, and acute renal failure were independent prognostic factors for mortality. In conclusion, the rate of penicillin resistance among pneumococcal blood isolates was high in the late 1990s, but penicillin resistance, and even high-level penicillin resistance, was not significantly associated with increased mortality in adults with pneumococcal bacteremia.
Collapse
|
231
|
Park SJ, Kim YY, Ju JW, Han BG, Park SI, Park BJ. Alternative splicing variants of c-FLIP transduce the differential signal through the Raf or TRAF2 in TNF-induced cell proliferation. Biochem Biophys Res Commun 2001; 289:1205-10. [PMID: 11741321 DOI: 10.1006/bbrc.2001.6086] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In human cancer, despite apoptotic activity, death-ligand promotes the cell cycle progression under certain conditions. In this study, we demonstrated that TNF-alpha-induced cell proliferation is achieved through the c-FLIP. In addition, alternative splicing variants (c-FLIP(L) and c-FLIP(S)) contribute the TNF-alpha-induced cell cycle promotion through distinct pathways. The long form of c-FLIP (c-FLIP(L)) activates the Raf, which enhance the activity of Erk and PI3K, whereas short form (c-FLIPS) are activated by c-jun-N-terminal Kinase (JNK) through the TNF receptor-associated factor (TRAF) 2. Since, however, recruitment of c-FLIP(L) into FADD is later than that of c-FLIP(S), the activation of PI3K and Erk show the late response to activation of JNK. We also show that each c-FLIP variant is regulated by a distinct molecular mechanism at the transcriptional level; c-FLIP(L) is induced by Erk, whereas c-FLIP(S), through the JNK activation, is like an autocrine regulatory loop. Therefore, the induction of c-FLIP(L) in response to TNF-alpha is achieved in a more delayed manner than that of c-FLIP(S). Our present study also implies that other alternative splicing variants perform differential roles in spite of the same pathway.
Collapse
|
232
|
Ivanisevic A, Im JH, Lee KB, Park SJ, Demers LM, Watson KJ, Mirkin CA. Redox-controlled orthogonal assembly of charged nanostructures. J Am Chem Soc 2001; 123:12424-5. [PMID: 11734050 DOI: 10.1021/ja011933d] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
233
|
Lee KJ, You HJ, Park SJ, Kim YS, Chung YC, Jeong TC, Jeong HG. Hepatoprotective effects of Platycodon grandiflorum on acetaminophen-induced liver damage in mice. Cancer Lett 2001; 174:73-81. [PMID: 11675154 DOI: 10.1016/s0304-3835(01)00678-4] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The protective effects of an aqueous extract from the roots of Platycodon grandiflorum A. DC (Campanulaceae), Changkil (CK), on acetaminophen (APAP)-induced hepatotoxicities and the possible protective mechanisms involved were investigated in mice. Pretreatment with CK prior to the administration of APAP significantly prevented the increase in serum alanine aminotransferase and aspartate aminotransferase activity and hepatic lipid peroxidation in a dose-dependent manner. APAP-induced hepatotoxicity was also essentially prevented as evidenced by liver histopathology. Hepatic glutathione levels and glutathione-S-transferase activities were not affected by treatment with CK alone, but pretreatment with CK protected the APAP-induced depletion of hepatic glutathione levels. The effects of CK on cytochrome P450 (P450) 1A2 and 2E1, the major isozymes involved in APAP bioactivation, were investigated. In microsomal incubations, CK effectively inhibited P450 lA2-dependent methoxyresorufin O-deethylase activities and the P450 2E1-dependent p-nitrophenol and aniline hydroxylase. The results suggest that the protective effects of CK against the APAP-induced hepatotoxicity may, at least in part, be due to its ability to block P450-mediated APAP bioactivation.
Collapse
|
234
|
You HJ, Choi CY, Kim JY, Park SJ, Hahm KS, Jeong HG. Ursolic acid enhances nitric oxide and tumor necrosis factor-alpha production via nuclear factor-kappaB activation in the resting macrophages. FEBS Lett 2001; 509:156-60. [PMID: 11741581 DOI: 10.1016/s0014-5793(01)03161-1] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ursolic acid (UA), a pentacyclic triterpene acid, is reported to have anti-tumor activities; however, the mechanism underlying its anti-tumorigenic effects is poorly understood. To further determine the mechanism of UA, we investigated the effects of UA on the release of nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha), and on the level of inducible nitric oxide synthase (iNOS) and TNF-alpha gene expression in mouse resting macrophages. We found that UA elicited a dose-dependent increase in NO and TNF-alpha production, and the level of iNOS and TNF-alpha mRNA. Transient expression and electrophoretic mobility shift assays with nuclear factor-kappaB (NF-kappaB) binding sites revealed that the increased level of iNOS mRNA and TNF-alpha mRNA induced by UA were mediated by the NF-kappaB transcription factor complex. These results demonstrate that UA stimulates NO and TNF-alpha release and is able to upregulate iNOS and TNF-alpha expression through NF-kappaB transactivation in the resting macrophages.
Collapse
|
235
|
Kim HJ, Lee JK, Kim JB, Park ES, Park SJ, Yoo DY, Yoon DY. Substituent effects on microstructure and polymerization of polyalkylsilsesquioxanes. J Am Chem Soc 2001; 123:12121-2. [PMID: 11724635 DOI: 10.1021/ja0168099] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
236
|
Abstract
BACKGROUND In elderly asthmatics, underdiagnosis is one of the important features. The main reason for underdiagnosis is thought to be a low frequency in complaining of symptoms due to the reduction of intellectual recognition and physical activity. Among the various symptoms, wheezing is the principal clue in diagnosing bronchial asthma, and decreased complaints for wheezing are also noted in elderly asthmatics. The objective of this study is to determine if less complaints of wheezing in elderly asthmatic is due to decrease in the development of wheezing. METHODS 61 young (20-39 years old), 68 middle-aged (40-59 years old) and 65 elderly (older than 60 years old) stable asthmatic subjects were studied (each group shall be called, hereafter, Young Group, Middle-aged Group and Old Group, respectively). During the methacholine induced airway narrowing, lung auscultation and questionnaire survey about presence and perception of wheezing were conducted in 194 asthmatics. RESULTS One hundred and sixty-nine patients (87%) developed wheezing during the methacholine induced airway obstruction. The frequency of wheezing during the methacholine challenge was found to be comparable among the groups. The methacholine concentration, % fall in FEV1, and FEV1 levels of the initial detection of wheezing were not different among the groups. Among the patients who developed wheezing, 47 patients (77%), 42 patients (61.8%) and 26 patients (40%) complained of wheezing in Young, Middle and Old Group, respectively. CONCLUSION In conclusion, the decreased perception of wheezing is a main factor for the low frequency of complaints of wheezing in elderly asthmatics.
Collapse
|
237
|
Park SJ, Cho SS, Oh JM, Han MK, Song YS, Bae HR, Yoo YH, Kim HM. Promoted expression of mast cell-specific proteases in IgE-dependent passive cutaneous anaphylaxis responses. Clin Chim Acta 2001; 314:231-6. [PMID: 11718700 DOI: 10.1016/s0009-8981(01)00706-9] [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: 11/27/2022]
Abstract
BACKGROUND Various factors can influence the protease expression phenotype of mast cells. METHODS In an effort to understand the potential role of the mast cell proteases in the IgE-dependent passive cutaneous anaphylaxis (PCA) responses of murine tissues, we studied the changes of proteases expression. The expressions of proteases were examined by Northern blotting and immunohistochemistry. RESULTS Promoted expression phenotypes of mouse mast cell protease (mMCP)-4, and rat mast cell protease I were accompanied by initiation of anti-dinitrophenyl (DNP) IgE-induced PCA responses, suggesting that the induction of these proteases expression are associated with IgE-mediated anaphylaxis responses. Elevated level of the L-histidine decarboxylase (HDC) mRNA expression was also observed in the PCA tissues and the activated mast cells, compared with that of the corresponding control tissue and cells, due to the activation of mast cells. CONCLUSIONS Promoted protease expression phenotype appears to be linked with the induction of HDC expression.
Collapse
|
238
|
Shin IS, Nam MJ, Park SJ, Youn HY, Han HR. Cloning of canine GM-CSF and SCF genes. J Vet Sci 2001; 2:159-66. [PMID: 12441694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023] Open
Abstract
Cytokines have pleiotropic regulatory effects on hematopoietic cells and many other cell types that participate in host defence and repair processes. Granulocyte-macrophage colony-stimulating factor (GM-CSF) mediates the growth and differentiation of granulocytes and macrophages and regulates the biological functions expressed by mature cells of these lineages. Stem cell factor (SCF) is a multifunctional cytokine involved in hematopoiesis, melanogenesis and gametogenesis. In order to determine the complementary DNA (cDNA) of canine GM-CSF and canine SCF, cDNA clones were generated from lipopolysaccharide (LPS) stimulated peripheral blood mononuclear cells (PBMCs) and bone marrow cells by reverse transcription PCR amplification. The canine GM-CSF cDNA obtained in this study contains an open reading frame encoding 144 amino acid residues and has 53-75% homology with those of human, cat, sheep, pig, cow and mouse, Canine SCF cDNA consist of an open reading frame encoding 274 amino acid residues and shares 81-92% homology with those of human, cat, pig, cow and mouse.
Collapse
|
239
|
Choi JW, Nam YS, Park SJ, Lee WH, Kim D, Fujihira M. Rectified photocurrent of molecular photodiode consisting of cytochrome c/GFP hetero thin films. Biosens Bioelectron 2001; 16:819-25. [PMID: 11679260 DOI: 10.1016/s0956-5663(01)00225-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Photoinduced electron transfer in the molecular electronic device consisting of protein-adsorbed hetero Langmuir-Blodgett (LB) film was investigated. Three kinds of functional molecules, cytochrome c, viologen, and green fluorescent protein (GFP) were used as an electron acceptor, a mediator, and a sensitizer, respectively. The hetero-LB film was fabricated by subsequently depositing cytochrome c and viologen onto the pretreated ITO or quartz glass. GFP adsorbed hetero-LB films were prepared by soaking the hetero-LB films into the buffer solution containing GFP. The MIM (metal/insulator/metal) structured molecular device was constructed by depositing aluminum onto the surface of the GFP-adsorbed hetero LB films. Due to the excitation by irradiation with a 460 nm monochromic light source, the photoinduced unidirectional flow of electrons in the MIM device could be achieved and was detected as photocurrents. The photoswitching function was achieved and the rectifying characteristic was observed in the molecular device. Based on the measurement of transient photocurrent of molecular device, the unidirectional flow of electrons was verified.
Collapse
|
240
|
Park JS, Won JY, Park SI, Park SJ, Lee DY. Percutaneous peritoneovenous shunt creation for the treatment of benign and malignant refractory ascites. J Vasc Interv Radiol 2001; 12:1445-8. [PMID: 11742023 DOI: 10.1016/s1051-0443(07)61707-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Peritoneovenous shunt placement has been reported as a treatment of refractory ascites by general surgeons, but without a clearly established role. The authors successfully inserted shunts under ultrasonographic and fluoroscopic guidance in 12 patients who had symptomatic refractory ascites (nine men, three women; mean maintenance duration, 88.5 d). Nine patients had advanced liver cirrhosis (five with superimposed hepatoma). Other patients had stomach cancer, colon cancer, and complicated polycystic kidney disease. The mortality rate was 83%. Causes of death included bleeding from preexisting varices, sepsis, hepatic failure, rupture of hepatoma, and disseminated intravascular coagulation. The authors describe the feasibility, technical details, and short-term results of percutaneous peritoneovenous shunt placement.
Collapse
|
241
|
Park SJ, Eden JG, Chen J, Liu C, Ewing JJ. Arrays of silicon microdischarge devices with multicomponent dielectrics. OPTICS LETTERS 2001; 26:1773-1775. [PMID: 18059694 DOI: 10.1364/ol.26.001773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Arrays as large as 15x15 of microdischarge devices having inverted pyramidal silicon cathodes (50mumx50mum) and SiO(2)- Si(3)N(4)- polymer composite dielectrics have been fabricated and characterized with Ne gas. The lifetimes, reliability, and ignition characteristics of the arrays are superior to those of earlier designs having a single polymer dielectric. Operating voltages as low as 150 V for a 10x10 pixel array and 1000 Torr of Ne have been measured. Single (50mumx50mum) pyramidal cathode devices operate at voltages as low as 113 V when the Ne pressure is 900 Torr.
Collapse
|
242
|
Park SJ, Kim IB, Choi KR, Moon JI, Oh SJ, Chung JW, Chun MH. Reorganization of horizontal cell processes in the developing FVB/N mouse retina. Cell Tissue Res 2001; 306:341-6. [PMID: 11702246 DOI: 10.1007/s004410100453] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2001] [Accepted: 07/25/2001] [Indexed: 10/28/2022]
Abstract
We investigated the morphological changes of horizontal cells after postnatal photoreceptor degeneration in the developing FVB/N mouse retina, using immunocytochemistry with anti-calbindin D-28K. From postnatal day 14 (P14) onwards, processes emerging from horizontal cells descend into the inner plexiform layer (IPL) and ramify mainly in stratum 1 of the IPL. Electron microscopy revealed that the descending processes make synaptic contacts with bipolar cells in the outer plexiform layer. Our results clearly demonstrate that loss of photoreceptor cells induces the reorganization of horizontal cell processes in the retinas of FVB/N mice as they mature.
Collapse
|
243
|
Gwon JS, Ju WK, Park SJ, Kim IB, Lee MY, Oh SJ, Chun MH. The regulatory expression of neuronal nitric oxide synthase in the ischemic rat retina. Neuroreport 2001; 12:3385-9. [PMID: 11711891 DOI: 10.1097/00001756-200110290-00047] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We investigated the expression and cellular localization of neuronal nitric oxide synthase (nNOS) in the rat retina, following ischemic injury induced by transient increase of intraocular pressure. In the normal retina, nNOS immunoreactivity was localized to certain populations of amacrine cells, displaced amacrine cells and a few bipolar cells. Following transient ischemia, retinal neurons expressing the immunoreactivity increased and peaked three days after reperfusion. Quantitative evaluation using immunoblotting confirmed that nNOS expression showed a peak value (500% of control levels) at 3 days, and then decreased again to 150% of controls by 4 weeks after reperfusion. Our findings suggest that this over-produced NO may act as a neurotoxic agent in the ischemic rat retina.
Collapse
|
244
|
Park SJ, Kim YY, Lim JY, Seo GJ, Kim J, Park SI, Park BJ. Opposite role of Ras in tumor necrosis factor-alpha-induced cell cycle regulation: competition for Raf kinase. Biochem Biophys Res Commun 2001; 287:1140-7. [PMID: 11587542 DOI: 10.1006/bbrc.2001.5713] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ras, a well-known oncogene, induces cell cycle stimulation through the Raf/Erk pathway and leads to cellular transformation, accompanied by other oncogenes such as c-myc and viral oncogenic protein. Here we suggest the interfering role of Ras in tumor necrosis factor (TNF)-alpha-induced cell cycle regulation. In TSU-Pr1 and T24 (oncogenic Ras cell lines), TNF-alpha suppresses cell cycle progression without induction of apoptosis, whereas AGS (wild-type Ras) is stimulated in its cell cycle by TNF-alpha coupled with activation of Erk. However, in TSU-Pr1 and T24, TNF-alpha leads to dephosphorylation of Erk1/2. Inhibition or activation of Ras can restore or convert TNF-alpha-induced cell cycle regulation in the cell lines containing the oncogenic Ras (TSU-Pr1 and T24) or AGS, respectively. Regulation of Erk also shows the coincidental pattern. We suggest the competition between the Ras pathway and TNF signaling for the binding to Raf, a common downstream target, as the cause of such reciprocal response, based on co-immunoprecipitation (co-IP) with antibodies against Raf and Ras or cellular Flice-inhibitory protein (c-FLIP), which have been recently identified upstream of Raf in death-ligand-induced cell cycle stimulation. Overexpression of Raf in TSU-Pr1, to reduce the competition, overcomes TNF-induced cell cycle arrest, also supporting our hypotheses.
Collapse
|
245
|
Tan WA, Tamai H, Park SJ, Plokker HW, Nobuyoshi M, Suzuki T, Colombo A, Macaya C, Holmes DR, Cohen DJ, Whitlow PL, Ellis SG. Long-term clinical outcomes after unprotected left main trunk percutaneous revascularization in 279 patients. Circulation 2001; 104:1609-14. [PMID: 11581137 DOI: 10.1161/hc3901.096669] [Citation(s) in RCA: 172] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Percutaneous coronary revascularization (PCI) has been increasingly applied to unprotected left main trunk (LMT) lesions, with varied long-term success. This study attempts to define the predictors of outcome in this population. METHODS AND RESULTS Two hundred seventy-nine consecutive patients who had LMT PCI at 1 of 25 sites between 1993 and 1998 were studied. Forty-six percent of these patients were deemed inoperable or at high surgical risk. Thirty-eight patients (13.7%) died in hospital, and the rest were followed up for a mean of 19 months. The 1-year incidence was 24.2% for all-cause mortality, 20.2% for cardiac mortality, 9.8% for myocardial infarction, and 9.4% for CABG. Independent correlates of all-cause mortality were left ventricular ejection fraction </=30%, mitral regurgitation grade 3 or 4, presentation with myocardial infarction and shock, creatinine >/=2.0 mg/dL, and severe lesion calcification. For the 32% of patients <65 years old with left ventricular ejection fraction >30% and without shock, the prevalence of these adverse risk factors was low. No periprocedural deaths were observed in this low-risk subset, and the 1-year mortality was only 3.4%. CONCLUSIONS Patients undergoing unprotected LMT PCI have frequent serious comorbidities and consequently have high event rates. PCI may be an alternative to CABG for a select proportion of elective patients and may also be appropriate for highly symptomatic inoperable patients. Meticulous follow-up of hospital survivors is required because of the rather high mortality during the first few months after treatment.
Collapse
|
246
|
Park SJ, Oh EJ, Yoo MA, Lee SH. Involvement of DNA-dependent protein kinase in regulation of stress-induced JNK activation. DNA Cell Biol 2001; 20:637-45. [PMID: 11749722 DOI: 10.1089/104454901753340622] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
DNA-dependent protein kinase (DNA-PK) is composed of a 460-kDa catalytic subunit and the regulatory subunits Ku70 and Ku80. The complex is activated on DNA damage and plays an essential role in double-strand-break repair and V(D)J recombination. In addition, DNA-PK is involved in S-phase checkpoint arrest following irradiation, although its role in damage-induced checkpoint arrest is not clear. In an effort to understand the role of DNA-PK in damage signaling, human and mouse cells containing the DNA-PK catalytic subunit (DNA-PKcs proficient) were compared with those lacking DNA-PKcs for c-Jun N-terminal kinase (JNK) activity that mediates physiologic responses to DNA damage. The DNA-PKcs-proficient cells showed much tighter regulation of JNK activity after DNA damage, while the level of JNK protein in both cell lines remained unchanged. The JNK proteins physically associated with DNA-PKcs and Ku70/Ku80 heterodimer, and the interaction was significantly stimulated after DNA damage. Various JNK isoforms not only contained a DNA-PK phosphorylation consensus site (serine followed by glutamine) but also were phosphorylated by DNA-PK in vitro. Together, our results suggest that DNA damage induces physical interaction between DNA-PK and JNK, which may in turn negatively affect JNK activity through JNK phosphorylation by DNA-PK.
Collapse
|
247
|
Abstract
Chest pain is the most common presenting symptom among patients with congenital pericardial defects. A delay in diagnosis of a congenital pericardial defect occurred in a patient because he had concomitant atherosclerotic coronary artery disease. Multiple radiological studies had suggested the diagnosis. The pericardial defect caused myocardial ischemia by obstructing flow in three coronary arteries. Surgical repair of the pericardial defect along with coronary artery bypass grafting was performed to correct the problem.
Collapse
|
248
|
Hong MK, Park SW, Moon DH, Oh SJ, Lee CW, Rhee KS, Sun F, Song JM, Kang DH, Song JK, Kim JJ, Park SJ. Intravascular ultrasound analysis of beta radiation therapy for diffuse in-stent restenosis to inhibit intimal hyperplasia. Catheter Cardiovasc Interv 2001; 54:169-73. [PMID: 11590678 DOI: 10.1002/ccd.1261] [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: 11/10/2022]
Abstract
We evaluated the efficacy of beta-radiation therapy ((188)Re-MAG(3)) to inhibit intimal hyperplasia (IH) in diffuse in-stent restenosis by intravascular ultrasound (IVUS) analysis in 50 patients. Nine patients who did not agree with radiation therapy, and therefore underwent rotational atherectomy and balloon angioplasty for diffuse in-stent restenosis in the same study period, were selected for control groups. Serial IVUS comparisons were available in 44 of 50 patients with radiation therapy and 7 of 9 control patients. At 6-month follow-up, there was less significant increase of IH area in patients with radiation therapy than in control patients (Delta IH area = 0.1 +/- 0.8 mm(2) vs. 2.6 +/- 1.8 mm(2), P > 0.001 in mean values, and 0.6 +/- 1.4 mm(2) vs. 2.9 +/- 2.1 mm(2), P = 0.026 in values of follow-up lesion site, respectively). In conclusion, beta-radiation therapy might be an effective treatment modality to inhibit intimal hyperplasia in patients with diffuse in-stent restenosis.
Collapse
|
249
|
Narimatsu M, Maeda H, Itoh S, Atsumi T, Ohtani T, Nishida K, Itoh M, Kamimura D, Park SJ, Mizuno K, Miyazaki J, Hibi M, Ishihara K, Nakajima K, Hirano T. Tissue-specific autoregulation of the stat3 gene and its role in interleukin-6-induced survival signals in T cells. Mol Cell Biol 2001; 21:6615-25. [PMID: 11533249 PMCID: PMC99807 DOI: 10.1128/mcb.21.19.6615-6625.2001] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2001] [Accepted: 07/02/2001] [Indexed: 11/20/2022] Open
Abstract
Signal transducer and activator of transcription 3 (STAT3) mediates signals of various growth factors and cytokines, including interleukin-6 (IL-6). In certain IL-6-responsive cell lines, the stat3 gene is autoregulated by STAT3 through a composite IL-6 response element in its promoter that contains a STAT3-binding element (SBE) and a cyclic AMP-responsive element. To reveal the nature and roles of the stat3 autoregulation in vivo, we generated mice that harbor a mutation in the SBE (stat3(mSBE)). The intact SBE was crucial for IL-6-induced stat3 gene activation in the spleen, especially in the red pulp region, the kidney, and both mature and immature T lymphocytes. The SBE was not required, however, for IL-6-induced stat3 gene activation in hepatocytes. T lymphocytes from the stat3(mSBE/mSBE) mice were more susceptible to apoptosis despite the presence of IL-6 than those from wild-type mice. Consistent with this, IL-6-dependent activation of the Pim-1 and junB genes, direct target genes for STAT3, was attenuated in T lymphocytes of the stat3(mSBE/mSBE) mice. Thus, the tissue-specific autoregulation of the stat3 gene operates in vivo and plays a role in IL-6-induced antiapoptotic signaling in T cells.
Collapse
|
250
|
Park SJ, Hong MK, Lee CW, Kim JJ, Song JK, Kang DH, Park SW, Mintz GS. Elective stenting of unprotected left main coronary artery stenosis: effect of debulking before stenting and intravascular ultrasound guidance. J Am Coll Cardiol 2001; 38:1054-60. [PMID: 11583882 DOI: 10.1016/s0735-1097(01)01491-7] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES We sought to evaluate: 1) the long-term outcomes of 127 selected patients receiving unprotected left main coronary artery (LMCA) stenting; and 2) the impact of the debulking procedure before stenting and intravascular ultrasound (IVUS) guidance on their clinical outcomes. BACKGROUND The long-term safety of stenting of unprotected LMCA stenoses has not been established yet. METHODS A total of 127 consecutive patients with unprotected LMCA stenosis and normal left ventricular function were treated by elective stenting. The long-term outcomes were evaluated between two groups: IVUS guidance (n = 77) vs. angiographic guidance (n = 50); and debulking plus stenting (debulking/stenting; n = 40) vs. stenting only (n = 87). RESULTS Angiographic restenosis was documented in 19 (19%) of 100 patients. The lumen diameter after stenting was significantly larger in IVUS-guided group (p = 0.003). The angiographic restenosis rate was significantly lower in the debulking/stenting group (8.3% vs. 25%, p = 0.034). The reference artery size was the only independent predictor of angiographic restenosis. During follow-up (25.5 +/- 16.7 months), there were four deaths, but no nonfatal myocardial infarctions occurred. The survival rate was 97.0 +/- 1.7% at two years. CONCLUSIONS These data suggest that stenting of unprotected LMCA stenosis might be associated with a favorable long-term outcome in selected patients. Guidance with IVUS may optimize the immediate results, and debulking before stenting seems to be effective in reducing the restenosis rate. However, we need a large-scale, randomized study.
Collapse
|