Sequence- and site-specific photodissociation at 266 nm of protonated synthetic polypeptides containing a tryptophanyl residue

Oh, Joo Yeon,Moon, Jeong Hee,Kim, Myung Soo John Wiley Sons, Ltd. 2004 Rapid communications in mass spectrometry Vol.18 No.22

<P>Photodissociation at 266 nm of protonated synthetic polypeptides containing a tryptophanyl residue was investigated using a homebuilt tandem time-of-flight mass spectrometer equipped with a matrix-assisted laser desorption/ionization source. Efficient photodissociation of the protonated peptides was demonstrated. Most of the intense peaks in the laser-induced tandem mass spectra were sequence ions. Furthermore, sequence ions due to cleavages at all the peptide bonds were observed; this is a feature of the technique that is particularly useful for peptide sequencing. Fragmentations at both ends of the tryptophanyl residue were especially prevalent, which can be useful for location of the tryptophanyl chromophore in a peptide. Copyright © 2004 John Wiley & Sons, Ltd.</P>

Rainfall-runoff analysis based on competing linear impulse responses: decomposition of rainfall-runoff processes

Yoo, Chulsang,Park, Jooyoung John Wiley Sons, Ltd. 2008 Hydrological processes Vol.22 No.5

<P>Many recent studies have successfully used neural networks for non-linear rainfall-runoff modelling. Due to fundamental limitation of linear structures, approaches employing linear models have been generally considered inferior to the neural network approaches in this area. However, the authors believe that with an appropriate extension, the concept of linear impulse responses can be a viable tool since it enables one to understand underlying dynamics of rainfall-runoff processes. In this paper, the use of competing impulse responses for rainfall-runoff analysis is proposed. The proposed method is based on the switch over of competing linear impulse-responses, each of which satisfies the constraints of non-negativity and uni-modality. The computational analyses performed for the rainfall-runoff data in the Seolma-Chun experimental basin, Korea showed that the proposed method can yield promising results. Considering the basin characteristics as well as the results from this study, it may be concluded that three impulse responses are enough for rainfall-runoff analysis. Copyright © 2007 John Wiley & Sons, Ltd.</P>

Formation of a scale on the hole surface of cooling nozzles in the hot strip mill process, obstructing a laminar flow of coolant

Huh, Yoon,Park, Shin Hwa,Jung, Se Hoon,Lee, Pil Jong,Cho, Myung Jong John Wiley Sons, Ltd 2012 Surface and interface analysis Vol.44 No.11

<P>We investigated on the formation of a scale on the hole surface of brass cooling nozzles in the hot strip mill process of steel manufacturing. High roughness of a nozzle hole surface due to the scale formation obstructs a laminar flow of coolant, which can result in the diminution of cooling efficiency of strips. Morphology and elemental composition of a scale formed on the hole surface of cooling nozzles used in the hot strip mill process for a long time were characterized with an electron microscope equipped with an energy dispersive X‐ray spectroscope. The scale is mainly composed of a foreign substance layer and an oxide layer. In addition, three kinds of cooling water were analyzed to investigate an inflow source for elemental constituents of the foreign substance layer. Copyright © 2012 John Wiley & Sons, Ltd.</P>

Functional characterization of the unconventional splicing of Yarrowia lipolytica HAC1 mRNA induced by unfolded protein response

Oh, Mi Hee,Cheon, Seon Ah,Kang, Hyun Ah,Kim, Jeong-Yoon John Wiley Sons, Ltd. 2010 Yeast Vol.27 No.7

<P>In the yeast Saccharomyces cerevisiae, the unfolded protein response (UPR) involves the unconventional splicing of HAC1 mRNA, which is mediated by the activated Ire1p transmembrane kinase/endonuclease. In this study, we isolated and characterized a Yarrowia lipolytica HAC1 (YlHAC1) encoding a basic-leucine zipper transcription factor. The null mutant strain of YlHAC1 (ΔYlhac1) displayed a significantly increased sensitivity to dithiothreitol (DTT) and tunicamycin (TM), along with a defect in hyphal growth, suggesting the essential function of YlHAC1 in UPR. The unconventional splicing of YlHAC1 mRNA occurred under the UPR conditions induced by DTT or TM treatment. Unlike S. cerevisiae HAC1 mRNA with an intron of 252 nt, YlHAC1 mRNA was shown to harbour a short intron of length 29 nt. The YlHAC1 mRNA harboured the nucleotides CAG, conserved at the intron borders in the filamentous fungi hac1/hacA and mammalian XBP1, as well as a conserved bipartite element within the 3′ untranslated region. The expression of the spliced form of YlHAC1 mRNA in the wild-type andΔYlhac1 strains resulted in an increased resistance to DTT, thereby indicating that the spliced form is translated into a functional YlHac1p. Copyright © 2010 John Wiley & Sons, Ltd.</P>

Phytoglycoprotein (75 kDa) inhibits expression of interleukin-1β stimulated by DEHP in human mast cells

Oh, Phil-Sun,Lim, Kwang,Lim, Kye-Taek John Wiley Sons, Ltd. 2010 CELL BIOCHEMISTRY AND FUNCTION Vol.28 No.5

<P>The purpose of this study is to investigate the inhibitory effect of a glycoprotein (CTB glycoprotein, 75 kDa) isolated from Cudrania tricuspidata Bureau (CTB) on the di-(2-ethylhexyl)phthalate (DEHP) induced expression of allergic-inflammation-related mediators in human mast cells. The changes on the levels of intracellular reactive oxygen species (ROS), mitogen-activated protein kinase (MAPK), transcription factor [nuclear factor (NF)-κB], and allergic inflammatory mediators [cyclooxygenase (COX)-2 and interleukin (IL)-1β] were evaluated using Western blot and RT-PCR. Our results showed that the CTB glycoprotein in the presence of DEHP inhibits the production of intracellular ROS, the phosphorylation of ERK1/2, and p38 MAPK in HMC-1 cells. In addition, the CTB glycoprotein has suppressive effects on the transcriptional activation of NF-κB, and on the expression levels of COX-2 and IL-1β in DEHP-treated HMC-1 cells. In conclusion, the CTB glycoprotein has a strong anti-inflammatory effect on the activities of allergic inflammatory mediators indirectly caused by DEHP in HMC-1 cells. Copyright © 2010 John Wiley & Sons, Ltd.</P>

Modification of gamma-radiation response in mice by green tea polyphenols

Lee, Hae June,Kim, Joong Sun,Moon, Changjong,Kim, Jong Choon,Lee, Yun Sil,Jang, Jong Sik,Jo, Sung Kee,Kim, Sung Ho John Wiley Sons, Ltd. 2008 Phytotherapy research Vol.22 No.10

<P>In this study we evaluated the effect of water extracts of green tea (GT) and mixtures of green tea polyphenols (GTPs), epigallocatechin gallate (EGCG), epicatechin gallate (ECG), epigallocatechin (EGC) and epicatechin (EC) on jejunal crypt survival, endogenous spleen colony formation, and apoptosis in jejunal crypt cells of mice irradiated with gamma-ray. The radioprotective effect of green tea was compared with the effect of diethyldithiocarbamate (DDC). Jejunal crypts were protected by pretreatment of GT and ECG. Administration of GT, GTPs and EC prior to irradiation resulted in an increase in the formation of endogenous spleen colonies. The frequency of apoptosis in crypt cells was also reduced by pretreatment of GT, GTPs, EGCG, ECG and EGC. In the experiment on the effect of catechins, the effects were partly contradicted in irradiated mice. The rank order of activity was ECG > EGC > EGCG > EC on intestinal crypt survival assay, EC > EGC > ECG > EGCG on the spleen colony formation assay, EGCG > EGC > EC > ECG on inhibiting the death of cells caused by apoptosis. The results indicate that GT and GTPs may have a major radioprotective effect. Each one of the catechins was a much less effective radioprotector, suggesting that total extract or a mixture of GTPs may be more effective than individual catechins. Copyright © 2008 John Wiley & Sons, Ltd.</P>

Development of an in vitro cell culture assay system for measuring the activation of a neighbouring gene by the retroviral vector

Hong, Youngtae,Yu, Seung Shin,Yoon, Nam-Kyung,Kang, Sung June,Lee, Jun-Tae,Kim, Sujeong,Kim, Jong-Mook,Lee, Karim,Jang, Ji-Won,Kim, Sunyoung John Wiley Sons, Ltd. 2008 The journal of gene medicine Vol.10 No.8

<B>Background</B><P>The use of retroviral vectors has shown an actual clinical benefit in a few inherited diseases. However, the occurrence of cases of leukemia after the X-SCID gene therapy trial raised concerns about the safety of insertional mutagenesis inherent to the biology of the retrovirus. Although the retrovirus has long been known to integrate into the host chromosome, and thus have the potential to activate the nearby gene, there has been no convenient method of studying or assaying such a cis-activation phenomenon.</P><B>Methods</B><P>In the present study, we report an in vitro assay system in which the effect of retroviral integration on the expression of the neighbouring gene can be studied. In this system, a retroviral vector and the neighbouring reporter gene were constructed in a single plasmid as if it had integrated into the chromosome.</P><B>Results</B><P>Using this assay, we found that the full-length long terminal repeat (LTR) could indeed activate the neighbouring gene expression from a distance and the magnitude of its activation was highly increased when this LTR was placed in the vicinity of the transcription start site of the gene, whereas the truncated LTR exerted little influence.</P><B>Conclusions</B><P>This assay system might provide a useful tool for selecting the appropriate vector structure, as well as for studying the molecular mechanism underlying the cis-activation by the viral LTR. Copyright © 2008 John Wiley & Sons, Ltd.</P>

Adaptive reference code‐based MAI cancellation for DS‐CDMA

Won, Jong Mook,Kim, Jung Soo,Kim, W. M. John Wiley Sons, Ltd. 2010 WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Vol.10 No.11

<P><B>Abstract</B></P><P>A computationally efficient and practically deployable adaptive reference code‐based multiple access interference (MAI) cancellation scheme, in which the conventional transmitter/receiver architecture is minimally modified only at the receiver (and/or transmitter) end, is proposed for direct sequence code division multiple access (DS‐CDMA) communication. Upon numerical and theoretical analyses, the proposed communications system is seen to always outperform the existing conventional communications system. The theoretical analyses and results as presented are generally useful and applicable to any situation wherein IS95 pseudo noise (PN) codes are employed towards multiple access. Copyright © 2009 John Wiley & Sons, Ltd.</P>

Determination of a selective Na⁺/H⁺ exchanger inhibitor, 4-cyano(benzo[b]thiophene-2-carbonyl)guanidine (KR-33028) in rat plasma by liquid chromatography–tandem mass spectrometry

Kim, Young Hoon,Ji, Hye Young,Lee, Seonkyoung,Yi, Kyu Yang,Kim, You Sun,Lee, Kyung Hee,Lee, Hye Suk John Wiley Sons, Ltd. 2007 Biomedical chromatography Vol.21 No.8

<P>A liquid chromatography-tandem mass spectrometric (LC/MS/MS) method was developed for the determination of a selective Na<SUP>+</SUP>/H<SUP>+</SUP> exchanger inhibitor 4-cyano(benzo[b]thiophene-2-carbonyl)guanidine (KR-33028) in rat plasma. KR-33028 and the internal standard, linezolid, were extracted from rat plasma with ethyl acetate at neutral pH. The analytes were separated on an XBridge C<SUB>18</SUB> column with a mixture of methanol–0.1% formic acid (35:65, v/v) as mobile phase and detected using an electrospray ionization tandem mass spectrometry in the multiple-reaction-monitoring mode. The standard curve was linear (r = 0.9998) over the concentration range of 2.0–1000 ng/mL. The coefficients of variation of intra- and inter-assay were 1.3–6.8% and the relative error was 0.8–5.0%. The recoveries of KR-33028 and linezolid were 70.5 and 84.6%, respectively. The lower limit of quantification for KR-33028 was 2.0 ng/mL using 50 µL plasma sample. This method was successfully applied to the pharmacokinetic study of KR-33028 in rats. Copyright © 2007 John Wiley & Sons, Ltd.</P>

Cannabinoid type 1 receptor gene polymorphisms are not associated with olanzapine‐induced weight gain

Park, Young‐,Min,Choi, Jung‐,Eun,Kang, Seung‐,Gul,Koo, Seung‐,Hoi,Kim, Leen,Geum, Dongho,Lee, Heon‐,Jeong John Wiley Sons, Ltd 2011 HUMAN PSYCHOPHARMACOLOGY -CLINICAL AND EXPERIMENTA Vol.26 No.4

<P><B>Background</B></P><P>Olanzapine is an atypical antipsychotic known to cause considerable weight gain. The cannabinoid type 1 receptor has been reported to be involved in energy balance control, appetite stimulation, and increases in body weight.</P><P><B>Methods</B></P><P>In the present study, we investigated three polymorphisms (rs1049353, rs806368, and rs4707436) in the cannabinoid type 1 receptor gene (<I>CNR1</I>) and weight gain in Korean patients with schizophrenia receiving olanzapine treatment. Weight and height were measured prior to starting olanzapine and again after long‐term treatment in 78 patients with schizophrenia. <I>CNR1</I> polymorphisms were genotyped using PCR‐RFLP methods.</P><P><B>Results</B></P><P>The three <I>CNR1</I> polymorphisms were not associated with body weight changes from baseline to the endpoint after olanzapine treatment (<I>p</I> > 0.05). There were also no significant differences in genotype, allele, or haplotype frequencies between the high weight gain (at least 7%) and low weight gain (less than 7%) groups.</P><P><B>Conclusion</B></P><P>Within the limitations imposed by the smallness of the clinical sample, our findings suggest that <I>CNR1</I> polymorphisms are not associated with olanzapine‐induced weight gain. Copyright © 2011 John Wiley & Sons, Ltd.</P>