Regulation of cancer cell death by a novel compound, C604, in a c-Myc-overexpressing cellular environment

Jo, M.J.,Paek, A.R.,Choi, J.S.,Ok, C.Y.,Jeong, K.C.,Lim, J.H.,Kim, S.H.,You, H.J. North-Holland ; Elsevier Science Ltd 2015 european journal of pharmacology Vol.769 No.-

<P>The proto-oncogene c-Myc has been implicated in a variety of cellular processes, such as proliferation, differentiation and apoptosis. Several c-Myc targets have been studied; however, selective regulation of c-Myc is not easy in cancer cells. Herein, we attempt to identify chemical compounds that induce cell death in c-Myc-overexpressing cells (STF-cMyc and STF-Control) by conducting MTS assays on approximately 4000 chemical compounds. One compound, C604, induced cell death in STF-cMyc cells but not STF-Control cells. Apoptotic proteins, including caspase-3 and poly(ADP-ribose) polymerase (PAPP), were cleaved in C604-treated STF-cMyc cells. In addition, 5W620, HCT116 and NCI-H23 cells, which exhibit higher basal levels of c-Myc, underwent apoptotic cell death in response to C604, suggesting a role for C604 as an inducer of apoptosis in cancer cells with c-Myc amplification. C604 induced cell cycle arrest at the G2/M phase in cells, which was not affected by apoptotic inhibitors. Interestingly, C604 induced accumulation of c-Myc and Cdc25A proteins. In summary, a chemical compound was identified that may induce cell death in cancer cells with c-Myc amplification specifically through an apoptotic pathway. (C) 2015 Elsevier B.V. All rights reserved.</P>

Fabrication of ex situ processed MgB₂ wires using nano carbon doped powder

Lee, C.M.,Park, J.H.,Hwang, S.M.,Lim, J.H.,Joo, J.,Kang, W.N.,Kim, C.J. North-Holland 2009 Physica. C, Superconductivity Vol.469 No.15

We fabricated ex situ MgB<SUB>2</SUB> wires using C-doped MgB<SUB>2</SUB> powder as a precursor in order to improve the core density of the wires and their C doping content. The C-doped powder was prepared with Mg, B, and nano carbon (NC) powders by the in situ technique and then MgB<SUB>2-x</SUB>C<SUB>x</SUB> (x=0, 0.01, and 0.03) wires were fabricated by the ex situ technique using the powder-in-tube method. The phase formation, lattice change, and microstructure were characterized and correlated with the T<SUB>c</SUB> and J<SUB>c</SUB> variations. We observed that the ex situ wire had a higher core density than the in situ wire, however its morphology consisted of agglomerated particles, indicating that sintering and grain growth did not occur completely, even though the sintering was conducted at high temperature (1000<SUP>o</SUP>C). As the C content increased, T<SUB>c</SUB> decreased, while the decrease of J<SUB>c</SUB> with increasing magnetic field became smaller. The J<SUB>c</SUB> of MgB<SUB>1.97</SUB>C<SUB>0.03</SUB> wire made by the ex situ technique was 3.34kA/cm<SUP>2</SUP> at 6.6T and 5K which is comparable to that of the in situ wire (4.81kA/cm<SUP>2</SUP> at 6.6T and 5K).

Effect of Anodic Gas Compositions on the Overpotential in a Molten Carbonate Fuel Cell

Lee C.G.,Kim D.H.,Hong S.W.,Park S.H.,Lim H.C. The Korean Electrochemical Society 2006 한국전기화학회지 Vol.9 No.2

Anodic overpotential has been investigated with gas composition changes in a $100cm^2$ class molten carbonate fuel cell. The overpotential was measured with steady state polarization, reactant gas addition (RA), inert gas step addition (ISA), and electrochemical impedance spectroscopy (EIS) methods at different anodic inlet gas compositions, i.e., $H_2:CO_2:H_2O=0.69:0.17:0.14\;atm\;and\;H_2:CO_2:H_2O=0.33:0.33:0.33\;atm$, at a fixed $H_2$ flow rate. The results demonstrate that the anodic overpotential decreases with increasing $CO_2\;and\;H_2O$ flow rates, indicating the anode reaction is a gas-phase mass-transfer control process of the reactant species, $H_2,\;CO_2,\;and\;H_2O$. It was also found that the mass-transfer resistance due to the $H_2$ species slightly increases at higher $CO_2\;and\;H_2O$ flow rates. EIS showed reduction of the lower frequency semi-circle with increasing $H_2O\;and\;CO_2$ flow rate without affecting the high frequency semi-circle.

O-free polyacrylonitrile doping to improve the J_c(B) and H_c2 of MgB₂ wires

Hwang, S.M.,Sung, K.,Choi, J.H.,Kim, W.,Joo, J.,Lim, J.H.,Kim, C.J.,Park, Y.S.,Kim, D.H. North-Holland 2010 Physica. C, Superconductivity Vol.470 No.20

We selected polyacrylonitrile (PAN, -[C<SUB>3</SUB>H<SUB>3</SUB>N]-) as an O-free organic dopant and fabricated C-doped MgB<SUB>2</SUB> wires by in situ and powder-in-tube techniques. 0-5 wt.% PAN powders were uniformly mixed with B powder using a liquid mixing method. The precursor powders were mixed with Mg powder, filled into Fe tubes, and then drawn into wires. Sintering was performed at 900<SUP>o</SUP>C for 1h in a flowing Ar gas. The PAN doping decreased the critical temperature (T<SUB>c</SUB>) and a-axis lattice parameter, but significantly improved the critical current density (J<SUB>c</SUB>) in high fields, upper critical field (H<SUB>c2</SUB>), and irreversibility field (H<SUB>irr</SUB>) performances. These results are attributed to the replacement of B sites with C by the PAN doping. Furthermore, as expected, the MgO amount did not increase as the doping content increased. The J<SUB>c</SUB> of the PAN-doped MgB<SUB>2</SUB> wires was more than one order of magnitude higher than that of the undoped MgB<SUB>2</SUB> wire at 5K and 6.6T (1.46-3.82kA/cm<SUP>2</SUP> vs. 0.11kA/cm<SUP>2</SUP>).

Thermal Stability and Adhesion Improvement of Cu(Ag)/Mo Bilayer Metallization in Large-Area TFT-LCDs

H. M. Lee,J. G. Lee,C. H. Kang,C. O. Jeong,D. H. Kim,H. Ruh,J. H. Lee,J. H. Lee,S. Kim,S. K. Lim,S. Y. Kim,T. K. Hong 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.III

The addition of 1.4 at.% Ag to Cu thin films strongly influences the grain growth, stress relaxation, surface morphology, and adhesion to Mo glue layer. Annealing of the Cu(Ag)/Mo structures produced two distinct sets of microstructural changes occurring in temperature regimes between room temperature and 300 C, and 300 . 600 C. In the low temperature regime, Ag precipitates have a considerable effect in retarding the grain growth. At temperatures greater than 300 C, grain growth of Cu coincides with the coarsening of Ag particles and the outdiffusion of Ag to the Cu surface. The addition of Ag to Cu thin films also significantly enhanced thermal stability as a result of Ag precipitation along the grain boundaries and improved the adhesion strength of Cu(Ag) alloy to Mo, possibly due to the interfacial segregation of Ag. In addition, Cu(Ag)/Mo showed low resistivity of 2.3 . 1.9 μ -cm, depending on the annealing temperature. Since the Cu(Ag)/Mo structure shows excellent thermal stability and high adhesion properties with low resistivity, it can be used for interconnections in large-size TFT-LCDs.

T_c and J_c distribution in in situ processed MgB₂ bulk superconductors with/without C doping

Kim, C.J.,Kim, Y.J.,Lim, C.Y.,Jun, B.H.,Park, S.D.,Choo, K.N. The Korea Institute of Applied Superconductivity a 2014 한국초전도저온공학회논문지 Vol.16 No.2

Temperature dependence of magnetic moment (m-T) and the magnetization (M-H) at 5 K and 20 K of the in situ processed $MgB_2$ bulk pellets with/without carbon (C) doping were examined. The superconducting critical temperature ($T_c$), the superconducting transition width (${\delta}T$) and the critical current density ($J_c$) were estimated for ten test samples taken from the $MgB_2$ bulk pellets. The reliable m-T characteristics associated with the uniform $MgB_2$ formation were obtained for both $MgB_2$ pellets. The $T_cs$ and ${\delta}Ts$ of all test samples of the undoped $MgB_2$ were the same each other as 37.5 K and 1.5 K, respectively. The $T_cs$ and ${\delta}Ts$ of the C-doped $MgB_2$ were 36.5 K and 2.5 K, respectively. Unlike the m-T characteristics, there existed the difference among the M-H curves of the test samples, which might be caused by the microstructure variation. In spite of the slight $T_c$ decrease, the C doping was effective in enhancing the $J_c$ at 5 K.

Characterization of Phosphoinositide-3-kinase, Class 3 (PIK3C3) Gene and Association Tests with Quantitative Traits in Pigs

Kim, J.H.,Choi, B.H.,Lim, H.T.,Park, E.W.,Lee, S.H.,Seo, B.Y.,Cho, I.C.,Lee, J.G.,Oh, S.J.,Jeon, J.T. Asian Australasian Association of Animal Productio 2005 Animal Bioscience Vol.18 No.12

This study deals with the characterization of porcine PIK3C3 and association tests with quantitative traits. PIK3C3 belongs to the class 3 PI3Ks that participate in the regulation of hepatic glucose output, glycogen synthase, and antilipolysis in typical insulin target cells such as those in the such as liver, muscle system, and fat. On the analysis of full-length mRNA sequence, the length of the PIK3C3 CDS was recorded as 2,664 bps. As well, nucleotide and amino acid identities between human and pig subjects were 92% and 99%, respectively. Five SNPs were detected over 5 exons. We performed genotyping by using a SNP C2604T on exon24 for 145 F$_2$ animals (from a cross between Korean native boars and Landrace sows) by PCR-RFLP analysis with Hpy8I used to investigate the relationship between growth and fat depot traits. In the total association analysis, which doesn' consider transmission disequilibrium, the SNP showed a significant effect (p<0.05) on body weight and carcass fat at 30 weeks of age as well as a highly significant effect (p<0.01) on back fat. In an additional sib-pair analysis, C allele still showed positive and significant effects (p<0.05) on back fat thickness and carcass fat. Moreover, the effects of C allele on the means of within-family components for carcass fat and back fat were estimated as 2.76 kg and 5.07 mm, respectively. As a result, the SNP of porcine PIK3C3 discovered in this study could be utilized as a possible genetic marker for the selection of pigs that possess low levels of back fat and carcass fat at the slaughter weight.

H. pylori 제균 실패율과 clarithromycin 내성률의 일치성

허재형 ( J. H. Heo ),남승우 ( S. W. Nam ),노임환 ( I. H. Roe ),양미라 ( M. R. Yang ),김정택 ( J. T. Kim ),송일환 ( I. H. Song ),임창영 ( C. Y. Lim ),김정원 ( J. W. Kim ),신지현 ( J. H. Shin ) 대한소화기학회 2002 대한소화기학회 춘계학술대회 Vol.2002 No.-

<목적> H. pylori 제균 치료성적을 좌우하는 요소에는 약제와 대상 환자군의 선정, 균검사방법의 차이, 항생제 저항성 등이 중요시되고 있다. 이 중에서도 항생제 저항성은 나라간의 H. pylori 제균 성적을 다르게 하는 대표적인 원인이다. 우리나라는 제균률이 외국보다 저조하여 85%내외로 보고되고 있다. 본 연구의 목적은 H. pylori 제균 실패율과 clarithromycin 내성률을 조사하여 제균 실패 원인으로서의 clarithromycin

A peroxisome proliferator-activated receptor gamma agonist attenuates neurological deficits following spinal cord ischemia in rats

Kim, H.,Hwang, J.,Park, S.,Nahm, S.F.,Min, S.,Lim, C.,Park, K.,Han, S. C.V. Mosby Co 2014 Journal of Vascular Surgery Vol.59 No.4

Objective: Neuroprotective effects of the peroxisome proliferator-activated receptor gamma (PPARγ) agonist in cerebral ischemia have been reported, but the effect of a PPARγ agonist on spinal cord ischemia has not been investigated. The objective of this study was to investigate the effect of a PPARγ agonist on spinal cord ischemia. Pioglitazone, a PPARγ agonist, was administered in a rat model of spinal cord ischemia, and the extent of neurological damage and histological alterations were assessed. Methods: Forty-five rats were randomly enrolled into one of the three groups: (1) pioglitazone group (group PIO): rats were treated with pioglitazone 24 hours before ischemia; (2) control group (group C): rats were treated with the same volume of saline 24 hours before ischemia; and (3) sham group (group sham): rats were treated with the same volume of saline 24 hours before the sham surgery. Spinal cord ischemia was induced using a balloon-tipped catheter placed on the proximal descending aorta. Neurologic function was assessed using the motor deficit index (0 = normal, 6 = complete paralysis) during the 48 hours after reperfusion. Histological and biochemical evaluations were then performed. Results: Compared with group C, group PIO presented with lower motor deficit index 48 hours after reperfusion (5.0 [4.0-6.0] vs 3.0 [2.0-3.0]; group C vs group PIO, respectively; P < .001). Group PIO presented with a higher number of normal motor neurons (10.7 [8.1-11.9] vs 14.7 [14.0-15.3]; group C vs group PIO, respectively; P = .009) and a smaller area of infarcts (48.4% [46.3%-54.0%] vs 16.8% [11.5%-18.3%]; group C vs group PIO, respectively; P = .009) when compared with group C. The degree of inflammatory reactions, assessed by microglia activities, was significantly reduced in group PIO. Oxidative stress level, assessed using malonydialdehyde assay, was significantly reduced in group PIO relative to group C (192.21% [173.5%-206.4%] of sham vs 141.1% [131.7%-152.1%] of sham; group C vs group PIO, respectively; P = .007). The sham group exhibited no abnormality upon neurological or histological examination. Conclusions: PPARγ agonist pioglitazone pretreatment significantly reduces infarct volume and attenuates neurological deficits following spinal cord ischemia. The possible mechanism of neuroprotection by PPARγ agonist may involve modulation of inflammatory reaction and oxidative stress.

Conversion of single-crystalline C₆₀ nanodisks and nanorods into graphitic nanostructures via hydrogen thermal annealing

Lim, H,Shin, H S,Song, H J,Choi, H C IOP Pub 2009 Nanotechnology Vol.20 No.14

<P>We have developed a process to convert C<SUB>60</SUB> nanostructures into graphitic nanostructures. Disk-shaped and wire-shaped C<SUB>60</SUB> nanostructures synthesized by the liquid–liquid interfacial precipitation method, the vapor–solid process, and solvent evaporation were successfully converted into graphitic structures by thermal annealing in hydrogen at 900 °C. Scanning electron and tunneling electron microscopic studies confirmed that the converted nanostructures were composed of multi-graphitic structures such as multi-walled carbon nanotubes, carbon nanofibers, and carbon onions. Fourier transform Raman spectroscopy and conductance measurements were carried out to further confirm the successful formation of graphitic layers. In the Raman spectra, the nanostructures converted from C<SUB>60</SUB> disks showed signature D, G, and G<SUP>′</SUP> bands of graphitic structures, while the A<SUB>g</SUB> mode (1469 cm<SUP>−1</SUP>) of the original C<SUB>60</SUB> molecule disappeared. C<SUB>60</SUB> nanowire devices fabricated for the conductance measurements of the converted structures showed dramatically decreased resistance (<I>R</I>≈100 kΩ) compared to the pristine C<SUB>60</SUB> wire (<I>R</I>>100 MΩ). Further manipulation of the reaction environment, including the gas and the annealing temperature, may reveal a new way to attain diverse graphitic nanostructures economically. </P>