Novel signaling axis for ROS generation during K-Ras-induced cellular transformation

Park, M-T,Kim, M-J,Suh, Y,Kim, R-K,Kim, H,Lim, E-J,Yoo, K-C,Lee, G-H,Kim, Y-H,Hwang, S-G,Yi, J-M,Lee, S-J Macmillan Publishers Limited 2014 CELL DEATH AND DIFFERENTIATION Vol.21 No.8

Reactive oxygen species (ROS) are well known to be involved in oncogene-mediated cellular transformation. However, the regulatory mechanisms underlying ROS generation in oncogene-transformed cells are unclear. In the present study, we found that oncogenic K-Ras induces ROS generation through activation of NADPH oxidase 1 (NOX1), which is a critical regulator for the K-Ras-induced cellular transformation. NOX1 was activated by K-Ras-dependent translocation of p47<SUP>phox</SUP>, a subunit of NOX1 to plasma membrane. Of note, PKCδ, when it was activated by PDPK1, directly bound to the SH3-N domain of p47<SUP>phox</SUP> and catalyzed the phosphorylation on Ser348 and Ser473 residues of p47<SUP>phox</SUP> C-terminal in a K-Ras-dependent manner, finally leading to its membrane translocation. Notably, oncogenic K-Ras activated all MAPKs (JNK, ERK and p38); however, only p38 was involved in p47<SUP>phox</SUP>-NOX1-dependent ROS generation and consequent transformation. Importantly, K-Ras-induced activation of p38 led to an activation of PDPK1, which then signals through PKCδ, p47<SUP>phox</SUP> and NOX1. In agreement with the mechanism, inhibition of p38, PDPK1, PKCδ, p47<SUP>phox</SUP> or NOX1 effectively blocked K-Ras-induced ROS generation, anchorage-independent colony formation and tumor formation. Taken together, our findings demonstrated that oncogenic K-Ras activates the signaling cascade p38/PDPK1/PKCδ/p47<SUP>phox</SUP>/NOX1 for ROS generation and consequent malignant cellular transformation.

An emerging recombinant cluster of nephropathogenic strains of avian infectious bronchitis virus in Korea

Lim, T.H.,Lee, H.J.,Lee, D.H.,Lee, Y.N.,Park, J.K.,Youn, H.N.,Kim, M.S.,Lee, J.B.,Park, S.Y.,Choi, I.S.,Song, C.S. Elsevier Science 2011 Infection, genetics and evolution Vol.11 No.3

The infectious bronchitis virus (IBV) is continuously evolving through point mutation and recombination of their genome, subsequently the emergence of IBV variants complicates disease control. The objective of this study was to investigate genetic characterization of new IBV variants isolated from commercial chicken flocks in Korea collected between 2005 and 2010. Phylogenetic analysis revealed that all new IBV isolates belonged to Korean group II (K-II), which included the nephropathogenic IBV strains. However, the isolates formed a new gene cluster that was distinguished from the two distinct K-II subgroups (KM91-like and QX-like). Recombination events were identified in the S1 gene, with their putative parental strains being the KM91-like or QX-like subgroup. In addition, two crossover sites were observed in the S1 gene of IBV isolates. These results suggest that natural genetic recombination between heterologous strains classified into different genetic groups has occurred and may have caused the emergence of new IBV strains. This finding provides important information on IBV evolution and is essential for the effective control of IB in Korea.

Live attenuated nephropathogenic infectious bronchitis virus vaccine provides broad cross protection against new variant strains.

Lim, T-H,Kim, M-S,Jang, J-H,Lee, D-H,Park, J-K,Youn, H-N,Lee, J-B,Park, S-Y,Choi, I-S,Song, C-S Poultry Science Association, etc 2012 Poultry science Vol.91 No.1

<P>Infectious bronchitis virus (IBV) infections cause great economic losses to the poultry industry worldwide, and the emergence of new variant strains complicates disease control. The present study investigated the genetic and protectotypic features of newly emerged Korean IBV strains. A phylogenetic analysis showed that several recent isolates formed 2 different clusters (new cluster 1 and 2), which were distinct from other preexisting clusters. New cluster 1 IBV strains represented recombinants between Korean nephropathogenic strain KM91 and the QXIBV strain. New cluster 2 IBV strains showed low amino acid homology (<58.7%) compared with previous isolates. We evaluated the protective efficacy of commercial IBV vaccines (H120 and K2 strain) against these new isolates. In cross-protection studies, the H120 strain did not provide sufficient protection against these variants. However, highly attenuated nephropathogenic IBV vaccine, K2 strain, provided significantly higher levels of protection against variants compared with chickens vaccinated with H120 (P < 0.05 or better). These results indicate that the K2 vaccine could be helpful for the reduction of economic losses caused by newly evolving IBV recombinants (new cluster 1) and variants (new cluster 2).</P>

Performance characteristic of a tubular carbon-based fuel cell short stack coupled with a dry carbon gasifier

Lim, T.H.,Kim, S.K.,Yun, U.J.,Lee, J.W.,Lee, S.B.,Park, S.J.,Song, R.H. Pergamon Press ; Elsevier Science Ltd 2014 International journal of hydrogen energy Vol.39 No.23

A carbon gasified carbon-based fuel cell (CFC) short stack was fabricated and investigated for generating effective carbon fuel cell reactions. Anode-supported tubular CFC cells with a 45 cm<SUP>2</SUP> active electrode area were used to manufacture the CFC short stack, which was coupled with a dry gasifier induced by a reverse Boudouard reaction. Activated carbon (BET area 1800 m<SUP>2</SUP>/g) powder was mixed with K<SUB>2</SUB>CO<SUB>3</SUB> powder (5 wt.%) and used to fill a dry gasifier as a solid carbon fuel, and pure CO<SUB>2</SUB> gas was supplied to the gasifier. The CO fuel generated by the reverse Boudouard reaction in the dry gasifier increased the performance of the CFC short stack. The tubular CFC short stack showed a maximum power of 29.4 W at 800 <SUP>o</SUP>C. It was operated under a range of operating conditions by changing the operating temperature, flow rate of the pure CO<SUB>2</SUB> and the thermal cycle operation. The results indicate that the fabricated tubular CFC is a promising power generation system candidate for many practical applications, such as residential power generation (RPG) and stationary power systems.

Synthesis of the superconducting MgB₂ film on the W-wire by co-evaporation method

Lim, Y.J.,Park, S.C.,Chung, J.K.,Lee, T.K.,Song, K.J.,Kim, C.J. North-Holland 2010 Physica. C, Superconductivity Vol.470 No.20

We have synthesized the MgB<SUB>2</SUB>/W composite fiber by depositing MgB<SUB>2</SUB> film on the W-wire with co-evaporation system. Boron was sputtered with the RF-magnetron sputter and magnesium was thermally evaporated simultaneously during deposition. For the uniformity of the deposited layer and the precise stoichiometric compound formation of the MgB<SUB>2</SUB> film layer, specimen holding unit was rotated at a fixed rate and the sputtered rate of B and evaporated rate of Mg were controlled separately. After post-annealing of the MgB<SUB>2</SUB>/W-wire at 600<SUP>o</SUP>C, we could obtain 100-800nm MgB<SUB>2</SUB> layers with uniform composition. Occasionally un-reacted Mg or second phases such as MgWO<SUB>4</SUB> were observed depending on the experimental conditions. The phase evolution and the microstructure of the deposited MgB<SUB>2</SUB> film were investigated with XRD, SEM, and EDS. The superconducting transition temperatures (T<SUB>c</SUB>) and the average critical current density have been measured around ~33.5K and 3.7x10<SUP>3</SUP>A/cm<SUP>2</SUP>, respectively using the physical property measurement system (PPMS 9T, Quantum Design).

Outbreak of gizzard erosion associated with fowl adenovirus infection in Korea.

Lim, T-H,Kim, B-Y,Kim, M-S,Jang, J-H,Lee, D-H,Kwon, Y-K,Lee, J-B,Park, S-Y,Choi, I-S,Song, C-S Poultry Science Association, etc 2012 Poultry science Vol.91 No.5

<P>The pathogenicity of a fowl adenovirus serotype-1 (FAdV-1, K181 strain) isolated from a case of gizzard erosion in layer chickens was investigated in specific-pathogen-free (SPF) chicks. One-week-old SPF chicks were inoculated orally or intramuscularly with the isolate of FAdV-1 and euthanized for necropsy at 7, 14, and 21 d postinoculation. Although there were no clinical signs after inoculation, gizzard erosions were observed grossly and the virus was recovered from the gizzards in the inoculated chickens. Histologically, in the chickens that were infected orally, the lesions found in the gizzard consisted of severe degeneration and necrosis of glandular epitheliums and eosinophilic inclusion bodies. These results indicate that the Korean FAdV-1 isolate could induce gizzard lesions in chickens. Moreover, the present investigation reproduced an outbreak of gizzard erosion caused by FAdV-1 infection and, for the first time, described the isolation of FAdV-1 from chickens in Korea. These findings provide important information on the epidemiology and pathogenesis of FAdV-1 infection in chickens.</P>

Magnetoresistance of Si1−xMnx Semiconductor Thin Films Grown by Using Molecular Beam Epitaxy

T. T. Lan Anh,H. K. Lim,B. C. Lee,D. H. Kim,K. J. Baek,D. J. Kim,H. J. Kim,J. H. Kim,Y. E. Ihm 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.1

The magnetoresistance of Si1−xMnx (x = 0.065, 0.076, and 0.113) thin films grown by using molecular beam epitaxy has been studied. The electrical resistivities of Si0.935Mn0.065 and Si0.924Mn0.076 thin films show semiconductor behaviors. The magnetoresistance of Si0.935Mn0.065 and Si0.924Mn0.076 thin films is negative at low temperatures and gradually transits to positive as the temperature increases. The conduction is dominated by variable range hopping, and the negative magnetoresistance is attributed, in part, to spin-dependent scattering. The magnetoresistance of the Si0.887Mn0.113 thin film increases with temperature, revealing metallic characteristics at temperatures below 240 K. The magnetoresistance of the Si0.887Mn0.113 thin film is also negative at low temperatures and positive at 300 K, but the magnetoresistance has a minimum at the Curie temperature of the ferromagnetic SiMn phase. An intriguing anomalous magnetoresistance was also observed at room temperature. The magnetoresistance of Si1−xMnx (x = 0.065, 0.076, and 0.113) thin films grown by using molecular beam epitaxy has been studied. The electrical resistivities of Si0.935Mn0.065 and Si0.924Mn0.076 thin films show semiconductor behaviors. The magnetoresistance of Si0.935Mn0.065 and Si0.924Mn0.076 thin films is negative at low temperatures and gradually transits to positive as the temperature increases. The conduction is dominated by variable range hopping, and the negative magnetoresistance is attributed, in part, to spin-dependent scattering. The magnetoresistance of the Si0.887Mn0.113 thin film increases with temperature, revealing metallic characteristics at temperatures below 240 K. The magnetoresistance of the Si0.887Mn0.113 thin film is also negative at low temperatures and positive at 300 K, but the magnetoresistance has a minimum at the Curie temperature of the ferromagnetic SiMn phase. An intriguing anomalous magnetoresistance was also observed at room temperature.

새로 국내에서 밝혀진 균주(R19)와 전통적 균주를 이용하여 혈청학적으로 진단된 쯔쯔가무시병의 임상상 및 항체반응 양상

이수기,이은경,허충,임병욱,김용림,강재승,이진관,조준탁,박동철,박경현 대한감염학회 1991 감염 Vol.23 No.1

From September to December 1989, eighteen cases of tsutsugamushi disease were diagnosed by indirect immunofluorescent antibody test in Ulsan-Ulchu area. Their clinical features and patterns of antibody response to R. tsutsugamuschi were analyzed. It was most prevailing in female over 30 years old. Most of patients (16 patients) were rural inhabitants. Two patients in urban area had reaped the rice in the rice field at several days before onset of the disease. It occurred between September and November with a peak in October. Chief complaints of patients were febrile sensation with or without chills or headache. All patients had fever and chills. Headache and myalgia were common. In one patient, delirium with visual hallucination was seen. The major physical findings were skin rash (83%), eschr (78%), lymphadenopathy (11%). The skin rash appeared on whole body or on the trunk. The eschar appeared on the chest or abdomen or in the genial region. The antobody titer to R 19 that had been newly isolated strain in Korea was universally high. There often were anemia (31%), leukocytosis (23%). Microscopic hematuria and pyuria were also seen in routine urinalysis. Liver function tests showed eleveted aminotransferases and LDH. There were erythrophagocytic histiocytes in the bone marrows of six patients among the ten patients whose bone marrow had been aspirated. Chloramphenicol had been used in all patients. The mean time to alleviation of fever was 2.5 days. All patients were cured.

Comparison of the Haas and the Oxford classifications for prediction of renal outcome in patients with IgA nephropathy

Park, K.S.,Han, S.H.,Kie, J.H.,Nam, K.H.,Lee, M.J.,Lim, B.J.,Kwon, Y.E.,Kim, Y.L.,An, S.Y.,Kim, C.H.,Doh, F.M.,Koo, H.M.,Oh, H.J.,Kang, S.W.,Choi, K.H.,Jeong, H.J.,Yoo, T.H. W. B. Saunders Co ; Centrum Philadelphia 2014 Human pathology Vol.45 No.2

Pathologic features can provide valuable information for determining prognosis in IgA nephropathy (IgAN). However, it is uncertain whether the Oxford classification, a new classification of IgAN, can predict renal outcome better than previous ones. We conducted a retrospective cohort study in 500 patients with biopsy-proven IgAN between January 2002 and December 2010 to compare the ability of the Haas and the Oxford classifications to predict renal outcome. Primary outcome was a doubling of the baseline serum creatinine concentration (D-SCr). During a mean follow-up of 68months, 52 (10.4%) and 35 (7.0%) developed D-SCr and end-stage renal disease, respectively. There were graded increases in the development of D-SCr in the higher Haas classes. In addition, the primary endpoint of D-SCr occurred more in patients with the Oxford M and T lesions than those without such lesions. In multivariate Cox regression analyses, the Haas class V (HR, 12.19; P=.002) and the Oxford T1 (hazard ratio [HR], 6.68; P<.001) and T2 (HR, 12.16; P<.001) lesions were independently associated with an increased risk of reaching D-SCr. Harrell's C index of each multivariate model with the Haas and the Oxford classification was 0.867 (P=.015) and 0.881 (P=.004), respectively. This was significantly higher than that of model with clinical factors only (C=0.819). However, there was no difference in C-statistics between the 2 models with the Haas and the Oxford classifications (P=.348). This study suggests that the Haas and the Oxford classifications are comparable in predicting progression of IgAN.

The effect of 0.5 wt.% Ca addition on the hot compressive characteristics and processing maps of the cast and extruded Mg-3Al-1Zn alloys

Kwak, T.Y.,Lim, H.K.,Kim, W.J. Elsevier Sequoia 2016 JOURNAL OF ALLOYS AND COMPOUNDS Vol.658 No.-

The hot compressive characteristics and processing maps of the extruded 0.5 wt.% Ca-AZ31 (Ca-AZ31) alloy and the extruded AZ31 alloy were examined and compared in the temperature range between 473 and 673 K and in the strain rate range between 10<SUP>-3</SUP> and 10 s<SUP>-1</SUP>. The extruded Ca-AZ31 alloy had a smaller grain size (10.64 vs. 23.44 μm) and a more homogeneous microstructure than the extruded AZ31 alloy due to the presence of thermally stable Al<SUB>2</SUB>Ca particles in the former. The addition of 0.5 wt.% Ca increased the ignition temperature of AZ31 by 270.5 K. While the added Ca did not affect the activation energy for plastic flow, it slightly decreased the stress exponent and increased the flow stress level. Dislocation climb creep associated with stress exponents of 5-7 dominated the plastic flow of the extruded AZ31 and extruded Ca-AZ31 alloys. The power-law breakdown did not appear in either alloy under the given testing conditions. In comparison with the extruded AZ31 alloy, the extruded Ca-AZ31 alloy exhibited a poor hot workability at low temperatures below 523 K. However, there was an improved hot workability at higher temperatures due to the presence of the Al<SUB>2</SUB>Ca particles that promoted dynamic recrystallization (DRX) and retarded coarsening of the DRXed grains. Compared with the extruded Ca-AZ31 alloy, the cast Ca-AZ31 alloy with a much larger grain size (86.2 μm) and a coarser secondary phase structure exhibited a poor hot workability at high strain rates (10<SUP>-1</SUP>-10<SUP>0</SUP> s<SUP>-1</SUP>) over the entire testing temperature range due to the occurrence of unstable flow.