miR-302b maintains ''stemness'' of human embryonal carcinoma cells by post-transcriptional regulation of Cyclin D2 expression

Lee, N.S.,Kim, J.S.,Cho, W.J.,Lee, M.R.,Steiner, R.,Gompers, A.,Ling, D.,Zhang, J.,Strom, P.,Behlke, M.,Moon, S.H.,Salvaterra, P.M.,Jove, R.,Kim, K.S. Academic Press 2008 Biochemical and biophysical research communication Vol.377 No.2

Embryonic stem cells (ESCs) and embryonal carcinoma cells (ECCs) possess the remarkable property of self-renewal and differentiation potency. They are model preparations for investigating the underlying mechanisms of ''stemness''. microRNAs are recently discovered small noncoding RNAs with a broad spectrum of functions, especially in control of development. Here, we show that miR-302b indirectly regulates expression of the pluripotent stem cell marker Oct4, and it directly regulates expression of Cyclin D2 protein, a developmental regulator during gastrulation. Using loss-of function and gain-of function approaches, we demonstrate that functional miR-302b is necessary to maintain stem cell self-renewal and inhibit neuronal differentiation of human ECCs. During retinoic acid-induced neuronal differentiation, Cyclin D2 protein but not mRNA expression is strongly increased, concurrent with the down-regulation of miR-302b and Oct4. Our results suggest that miR-302b plays an important role in maintaining the pluripotency of ECCs and probably ESCs, by post-transcriptional regulation of Cyclin D2 expression.

급성 D. D. S. 중독증의 임상적 고찰

정시전 ( S. J. Chung ),최등영 ( D. Y. Choi ),이천각 ( C. K. Lee ),김형순 ( H. S. Kim ),태철현 ( T. H. Jeen ) 대한내과학회 1968 대한내과학회지 Vol.11 No.4

D.D.S. is well known as the drug of choice for Leprosy. Chronic D.D.S. intoxication has been reported in the many countries. It includes hematological changes, skin manifestations, abnormal liver function test and psychosis, There are few acute intoxicatio

Thermodynamic behaviors of excitonic emission in ZnO nanorods grown by pulsed laser deposition

Lee, Y.,Lee, D.J.,Cho, H.D.,Yoon, I.T.,Shon, Y.,Lee, S. North-Holland 2017 Journal of luminescence Vol.190 No.-

We investigated the thermodynamic behaviors of the exciton emission in ZnO nanorods that had been grown by laser ablation. The ZnO nanorods exhibited a clear luminescence peak from the neutral donor-bound exciton (D<SUP>0</SUP>X), which persisted near room temperature. Through analyzing temperature-dependences of photoluminescence properties, we found out insignificant thermal-quenching of D<SUP>0</SUP>X, arising from the large donor binding energy (i.e., E<SUB>bD(NR)</SUB> ~ 51.1 +/- 7.3meV). A small discrepancy of E<SUB>bD(NR)</SUB> from ZnO bulks' values (i.e., E<SUB>bD(Bulk)</SUB> = 53 - 72meV) is associated with inhomogeneous thermal-broadening factors such as defect-scattering at the surface of the nanorod. Despite of inhomogeneous thermal-broadening, the ZnO nanorods still have a high luminescence efficiency because of the weak homogeneous thermal-broadening effect (i.e., low exciton-phonon coupling).

Probiotic properties of Pediococcus strains isolated from jeotgals, salted and fermented Korean sea-food

Lee, K.W.,Park, J.Y.,Sa, H.D.,Jeong, J.H.,Jin, D.E.,Heo, H.J.,Kim, J.H. Academic Press 2014 Anaerobe Vol.28 No.-

Three Pediococcus pentosaceus strains were isolated from jeotgals, salted and fermented Korean sea-foods, and their probiotic potentials were examined. After 2 h exposure to pH 3.0, P. pentosaceus F66 survived with the survival ratio of 32.6% followed by P. pentosaceus D56 (17.2%) and P. pentosaceus A24 (7.5%). P. pentosaceus F66 also survived better (26.6%) than P. pentosaceus A24 (13.7%) and P. pentosaceus D56 (5.8%) after 2 h exposure to 0.3% bile salts. Three strains grew slowly on MRS broth with 15% NaCl (w/v), reaching the OD<SUB>600</SUB> values of 0.4-0.8 in 36 h. They adhered to Caco-2 cells (10.9-13.9 CFU/cell) with similar degree of adherence of a positive control, Lactobacillus rhamnosus GG (12.8 +/- 0.5 CFU/cell). Three strains possess some desirable enzyme activities such as β-galactosidase, α-glucosidase, β-glucosidase, and N-acetyl-β-glucosidase. From these results, P. pentosaceus F66 seems qualified as a probiotic and can be utilized for fermented foods including jeotgals.

Development of the new KSTAR helium distribution box

Lee, Y.J.,Kwag, S.W.,Song, N.H.,Park, D.S.,Chang, Y.B.,Moon, K.M.,Kim, N.W.,Joo, J.J.,Lee, C.H.,Kim, K.P.,Song, J.I.,Park, S.H.,Kim, H.T.,Ahn, H.J.,Kim, Y.S. Elsevier 2017 Fusion engineering and design Vol.123 No.-

<P><B>Abstract</B></P> <P>KSTAR project has required the new helium distribution box named upgraded distribution box (DBU) for the operation of the cryogenic components such as in-vessel cryo-pump (CPI), super-sonic molecular beam injector (SMBI), and deuterium pellet injection system (PIS). Two CPIs are inserted into the tokamak vacuum vessel and these components shall be operated at 90K for the liquid nitrogen thermal shields and 4.5K for the hydrogen cryo-panel. One hydrogen PIS was newly mounted on the tokamak for the 2016 KSTAR campaign. Liquid nitrogen shall be supplied to the one SMBI. For the operation of above mentioned 3 kinds of cryogenic components, a helium refrigerator, which had been used for the R&D in the KSTAR facility construction phase (2002–2013), was moved and inserted into the KSTAR 9kW helium facility room. The cooling capacity of the refrigerator at 4.5K is 1kW and it was manufactured from the Linde Kryotechnik before 2002. After some maintenances in warm compressor, electrical power supply, oil-filter, and so on, commissioning of the refrigerator up to 4.5K was accomplished successfully. From the beginning of 2015, design and fabrication of the DBU was started. It shall control the liquid nitrogen for the SMBI and CPI thermal shields whereas liquid helium for the CPI cryo-panel and PIS. To minimize the temperature of the liquid nitrogen to be supplied to SMBI and CPI, a thermal damper tank was inserted into the distribution box. Nitrogen return gases are to be warmed up to room temperature at the heater in the distribution box. A 1000l of liquid helium vessel is located nearby the PIS to supply cold gas helium (∼5K). Because the CPI cryo-panel requires regeneration up to 90K, complex regeneration and re-cool down scenario was developed and applied to the DBU. Including operational results, details of the DBU progresses will be reported in this paper.</P> <P><B>Highlights</B></P> <P> <UL> <LI> There has been progresses in the construction and 1st operation of DBU in 2016 KSTAR plasma experiments. </LI> <LI> Two in-vessel cryopumps (CPIs) cool-down to 4.5K and observed pumping speed was 3.0E4l/s. </LI> <LI> Manual CPI regeneration tests were accomplished regarding future automatic control. </LI> <LI> Production of the D<SUB>2</SUB> pellets were successful and there has been lots of injection tests. </LI> </UL> </P>

Crystal structures of LacD from Staphylococcus aureus and LacD.1 from Streptococcus pyogenes: Insights into substrate specificity and virulence gene regulation

Lee, S.J.,Kim, H.S.,Kim, D.J.,Yoon, H.J.,Kim, K.H.,Yoon, J.Y.,Suh, S.W. North-Holland Pub ; Elsevier Science Ltd 2011 FEBS letters Vol.585 No.2

Staphylococcus aureus LacD, a Class I tagatose-1,6-bisphosphate (TBP) aldolase, shows broadened substrate specificity by catalyzing the cleavage of 1,6-bisphosphate derivatives of d-tagatose, d-fructose, d-sorbose, and d-psicose. LacD.1 and LacD.2 are two closely-related Class I TBP aldolases in Streptococcus pyogenes. Here we have determined the crystal structures of S. aureus LacD and S. pyogenes LacD.1. Monomers of both enzymes are folded into a (β/α)<SUB>8</SUB> barrel and two monomers associate tightly to form a dimer in the crystals. The structures suggest that the residues E189 and S300 of rabbit muscle Class I fructose-1,6-bisphosphate (FBP) aldolase are important for substrate specificity. When we mutated the corresponding residues of S. aureus LacD, the mutants (L165E, L275S, and L165E/L275S) showed enhanced substrate specificity toward FBP. Structured summary: lacDbinds to lacD by X-ray crystallography(View interaction) lacD1binds to lacD1 by X-ray crystallography(View interaction)

Clinical outcomes of venous thromboembolism with dalteparin therapy in multiple myeloma patients

Lee, S.E.,Jeon, Y.W.,Yoon, J.H.,Cho, B.S.,Eom, K.S.,Kim, Y.J.,Kim, H.J.,Lee, S.,Cho, S.G.,Kim, D.W.,Lee, J.W.,Min, W.S.,Kim, M.,Min, C.K. Pergamon Press 2015 Thrombosis research Vol.136 No.5

This study focused on the clinical outcomes in multiple myeloma (MM) patients with venous thromboembolism (VTE) who received low-molecular-weight heparin (dalteparin) therapy. Changes in D-dimer levels before and after VTE were also evaluated. Among 549 patients treated with various chemotherapeutic agents, a total of 52 (9.47%) patients including 32 newly diagnosed with MM and 16 with relapsed/refractory MM developed VTE, 48 of whom received dalteparin. Among the 48 treated patients, 37 (77%) had proximal deep vein thrombosis (DVT), four had (8%) pulmonary embolism (PE), and seven (15%) had both DVT and PE. In 32 patients with available paired samples (at baseline and VTE occurrence), significant conversion of D-dimer levels from 2.2+/-0.4mg/L to 11.8+/-1.6mg/L (P<0.001) was observed, which decreased from 10.9+/-0.4mg/L to 1.9+/-0.6mg/L one month after initiating dalteparin therapy. A total of 44 patients received dalteparin with a median duration of 4.2months (range, 2.7-9.4), and four patients were discontinued early due to death (n=3) and major bleeding (n=1). After a median follow-up of 9.0months (range, 0.7-35.8) since the first VTE episode, five patients showed recurrence of VTE with a cumulative incidence of 17.5+/-7.9%. Major bleeding occurred in three patients. In summary, dalteparin seems to be a promising drug for the treatment of VTE in MM. In addition, the significant difference in D-dimer levels observed before occurrence of VTE and after dalteparin treatment may suggest the usefulness of D-dimer testing as a surrogate marker for VTE in MM patients.

Bacillus alkalitelluris sp. nov., an alkaliphilic bacterium isolated from sandy soil

Lee, J.-C.,Lee, G. S.,Park, D.-J.,Kim, C.-J. Microbiology Society 2008 International journal of systematic and evolutiona Vol.58 No.11

<P>A Gram-positive, alkaliphilic bacterium, designated strain BA288(T), was isolated from sandy soil. Cells were facultatively anaerobic, endospore-forming rods that were motile by means of peritrichous flagella. The strain grew at 15-40 degrees C and pH 7.0-11.0 (optimally at 30 degrees C and pH 9.0-9.5) and at salinities of 0-4 % (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain BA288(T) belonged to the genus Bacillus and that Bacillus herbersteinensis D-1,5a(T), Bacillus humi LMG 22167(T), Bacillus cohnii DSM 6307(T) and Bacillus litoralis SW-211(T) were the closest neighbours (96.2, 96.0, 96.0 and 95.9 % sequence similarity, respectively). The genomic DNA G+C content was 37.9 mol% and the predominant menaquinone was MK-7. The major cellular fatty acids were anteiso-C(15 : 0), iso-C(15 : 0), C(16 : 0) and iso-C(14 : 0). The peptidoglycan type was A1gamma (meso-diaminopimelic acid). Therefore, on the basis of phylogenetic, phenotypic and chemotaxonomic properties, strain BA288(T) represents a novel species of the genus Bacillus, for which the name Bacillus alkalitelluris sp. nov. is proposed. The type strain is BA288(T) (=KCTC 3947(T) =DSM 16976(T)).</P>

Effects of long-time service at high temperature on the material strength and J-R curve of Grade 91 steel

Lee, H.Y.,Lim, D.W.,Jeong, J.Y. Pergamon Press ; Elsevier Science Ltd 2017 Engineering fracture mechanics Vol.178 No.-

<P>The effects of long-time service at high temperature on the material strength, ductility, and J-Resistance behavior of Mod.9Cr-1Mo (ASME Grade 91) steel were investigated based on tensile and J-R tests with virgin and service-exposed Gr.91 steel specimens. The service exposed Gr.91 steel specimens were sampled from a tee junction in a reheat steam piping system of an ultra-supercritical (USC) plant in Korea with an accumulated operation time of 73,716 h. Comparisons of the test data were made not only between the test results of the virgin materials and service-exposed materials but also between the test results and the material properties in the elevated temperature design (ETD) codes. These test data of yield strength (YS) and tensile strength (TS) for the virgin and service-exposed Gr.91 steel were compared with those of the ETD code, which showed that the current ETD code overestimates the YS and TS properties for long-time service in a non-conservative manner for Gr.91 steel. J-R test data currently not available in ETD codes were produced over a range of temperatures for virgin and service-exposed Gr.91 steel. The effects of longtime service in J-R curve were investigated. (C) 2017 Elsevier Ltd. All rights reserved.</P>

Ahnak functions as a tumor suppressor via modulation of TGFβ/Smad signaling pathway

Lee, I H,Sohn, M,Lim, H J,Yoon, S,Oh, H,Shin, S,Shin, J H,Oh, S-H,Kim, J,Lee, D K,Noh, D Y,Bae, D S,Seong, J K,Bae, Y S Macmillan Publishers Limited 2014 Oncogene Vol.33 No.38

We provide detailed mechanisms of Ahnak-mediated potentiation of transforming growth factor β (TGFβ) signaling, which leads to a negative regulation of cell growth. We show that Smad3 interacts with Ahnak through MH2 domain and that Ahnak stimulates Smad3 localization into nucleus leading to potentiating TGFβ-induced transcriptional activity of R-Smad. Moreover, overexpression of Ahnak resulted in growth retardation and cell cycle arrest through downregulation of c-Myc and cyclin D1/D2. We describe results from analyses of Ahnak<SUP>−/−</SUP> mouse model expressing middle T antigen in a mammary gland-specific manner (MMTV<SUP>Tg/+</SUP>Ahnak<SUP>−/−</SUP>), which showed significantly progressed hyperplasia of mammary glands compared with MMTV<SUP>Tg/+</SUP>Ahnak<SUP>+/+</SUP>. Finally, we screened multiple human breast cancer tissues and showed that the expression of Ahnak in cancer tissues is lower than that in control tissues by 50%. Taken together, these data indicate that Ahnak mediates a negative regulation of cell growth and acts as novel tumor suppressor through potentiation of TGFβ signaling.