<i>CYP2A6</i> and <i>ERCC1</i> polymorphisms correlate with efficacy of S-1 plus cisplatin in metastatic gastric cancer patients

Park, S R,Kong, S-Y,Nam, B-H,Choi, I J,Kim, C G,Lee, J Y,Cho, S J,Kim, Y W,Ryu, K W,Lee, J H,Rhee, J,Park, Y-I,Kim, N K Nature Publishing Group 2011 The British journal of cancer Vol.104 No.7

<P><B>Background:</B></P><P>We evaluated the association between polymorphisms of cytochrome P450 2A6 (<I>CYP2A6</I>)/excision repair cross-complementation group 1 (<I>ERCC1</I>)/X-ray repair cross-complementing group 1(<I>XRCC1</I>) and treatment outcomes of metastatic gastric cancer (MGC) patients treated with S-1/cisplatin.</P><P><B>Methods:</B></P><P>Among MGC patients (<I>n</I>=108), who received S-1 (40 mg m<SUP>−2</SUP> b.i.d., days 1–14) and cisplatin (60 mg m<SUP>−2</SUP>, day 1) every 3 weeks, we analysed the wild-type allele (<I>W</I>) and variants (<I>V</I>) of <I>CYP2A6</I> (<I>*4</I>, <I>*7, *9, *10</I>), and the polymorphisms of <I>ERCC1</I> (rs11615, rs3212986) and <I>XRCC1</I> (rs25487).</P><P><B>Results:</B></P><P>Patients having fewer <I>CYP2A6</I> variants had better response rates (<I>W</I>/<I>W vs W</I>/<I>V</I> other than <I>*1/*4 vs V</I>/<I>V</I> or <I>*1/*4</I>=66.7 <I>vs</I> 58.3 <I>vs</I> 32.3% <I>P</I>=0.008), time to progression (TTP) (7.2 <I>vs</I> 6.1 <I>vs</I> 3.5 months, <I>P</I>=0.021), and overall survival (23.2 <I>vs</I> 15.4 <I>vs</I> 12.0 months, <I>P</I>=0.004). <I>ERCC1 19442C</I>><I>A</I> (rs3212986) was also associated with response rate (<I>C/C</I>, 46.7% <I>vs C/A</I>, 55.3% <I>vs A/A</I>, 87.5%) (<I>P</I>=0.048) and TTP (4.4 <I>vs</I> 7.6 <I>vs</I> 7.9 months) (<I>P</I>=0.012). Patients carrying both risk genotypes of <I>CYP2A6</I> (<I>V</I>/<I>V</I> or <I>1/*4</I>) and <I>ERCC1 19442C</I>><I>A</I> (<I>C/C</I>) <I>vs</I> those carrying none showed an adjusted odds ratio of 0.113 (<I>P</I>=0.004) for response, and adjusted hazard ratios of 3.748 (<I>P</I>=0.0001) for TTP and 2.961 (<I>P</I>=0.006) for death.</P><P><B>Conclusion:</B></P><P>Polymorphisms of <I>CYP2A6</I> and <I>ERCC1 19442C</I>><I>A</I> correlated with the efficacy of S-1/cisplatin.</P>

Bacillus cereus and Bacillus thuringiensis spores in Korean rice: Prevalence and toxin production as affected by production area and degree of milling

Kim, B.,Bang, J.,Kim, H.,Kim, Y.,Kim, B.s.,Beuchat, L.R.,Ryu, J.H. Academic Press 2014 FOOD MICROBIOLOGY Vol.42 No.-

We determined the prevalence of and toxin production by Bacillus cereus and Bacillus thuringiensis in Korean rice as affected by production area and degree of milling. Rough rice was collected from 64 farms in 22 agricultural areas and polished to produce brown and white rice. In total, rice samples were broadly contaminated with B. cereus spores, with no effect of production area. The prevalence and counts of B. cereus spores declined as milling progressed. Frequencies of hemolysin BL (HBL) production by isolates were significantly (P @? 0.01) reduced as milling progressed. This pattern corresponded with the presence of genes encoding the diarrheal enterotoxins. The frequency of B. cereus isolates positive for hblC, hblD, or nheB genes decreased as milling progressed. Because most B. cereus isolates from rice samples contained six enterotoxin genes, we concluded that B. cereus in rice produced in Korea is predominantly of the diarrheagenic type. The prevalence of B. thuringiensis in rice was significantly lower than that of B. cereus and not correlated with production area. All B. thuringiensis isolates were of the diarrheagenic type. This study provides information useful for predicting safety risks associated with B. cereus and B. thuringiensis in rough and processed Korean rice.

The inability of Bacillus licheniformis perR mutant to grow is mainly due to the lack of PerR-mediated fur repression

Kim, J. H.,Yang, Y. M.,Ji, C. J.,Ryu, S. H.,Won, Y. B.,Ju, S. Y.,Kwon, Y.,Lee, Y. E.,Youn, H.,Lee, J. W. MICROBIOLOGICAL SOCIETY OF KOREA 2017 JOURNAL OF MICROBIOLOGY -SEOUL- Vol. No.

<P>PerR, a member of Fur family protein, is a metal-dependent H2O2 sensing transcription factor that regulates genes involved in peroxide stress response. Industrially important bacterium Bacillus licheniformis contains three PerR-like proteins (PerR(BL), PerR2, and PerR3) compared to its close relative Bacillus subtilis. Interestingly, unlike other bacteria including B. subtilis, no authentic perR (BL) null mutant could be established for B. licheniformis. Thus, we constructed a conditional perR (BL) mutant using a xylose-inducible promoter, and investigated the genes under the control of PerR(BL). PerR(BL) regulon genes include katA, mrgA, ahpC, pfeT, hemA, fur, and perR as observed for PerR(BS). However, there is some variation in the expression levels of fur and hemA genes between B. subtilis and B. licheniformis in the derepressed state. Furthermore, katA, mrgA, and ahpC are strongly induced, whereas the others are only weakly or not induced by H2O2 treatment. In contrast to the B. subtilis perR null mutant which frequently gives rise to large colony phenotype mainly due to the loss of katA, the suppressors of B. licheniformis perR mutant, which can form colonies on LB agar, were all catalase-positive. Instead, many of the suppressors showed increased levels of siderophore production, suggesting that the suppressor mutation is linked to the fur gene. Consistent with this, perR fur double mutant could grow on LB agar without Fe supplementation, whereas perR katA double mutant could only grow on LB agar with Fe supplementation. Taken together, our data suggest that in B. licheniformis, despite the similarity in PerR(BL) and PerR(BS) regulon genes, perR is an essential gene required for growth and that the inability of perR null mutant to grow is mainly due to elevated expression of Fur.</P>

Effect of Crystallization Treatment on the Magnetic Properties of Amorphous Strips Based on Co-Fe-Ni-B-Si-Cr Containing Nitrogen

Cho H.J.,Kwon H.T.,Ryu H.H.,Sohn K.Y.,You B.S.,Park W.W. The Korean Powder Metallurgy Institute 2006 한국분말재료학회지 (KPMI) Vol.13 No.4

Co-Fe-Ni-B-Si-Cr based amorphous strips containing nitrogen were manufactured via melt spinning, and then devitrified by crystallization treatment at the various annealing temperatures of $300^{\circ}C{\sim}540^{\circ}C$ for up to 30 minutes in an inert gas $(N_2)$ atmosphere. The microstructures were examined by using XRD and TEM and the magnetic properties were measured by using VSM and B-H meter. Among the alloys, the amorphous ribbons of $Co_{72.6}Fe_{9.8}Ni_{5.5}B_{2.4}Si_{7.1}Cr_{2.6}$ containing 121 ppm of nitrogen showed relatively high saturation magnetization. The alloy ribbons crystallized at $540^{\circ}C$ showed that the grain size of $Co_{72.6}Fe_{9.8}Ni_{5.5}B_{2.4}Si_{7.1}Cr_{2.6}$ alloy containing 121 ppm of nitrogen was about f nm, which exhibited paramagnetic behavior. The formation of nano-grain structure was attributed to the finely dispersed Fe4N particles and the solid-solutionized nitrogen atoms in the matrix. Accordingly, it can be concluded that the nano-grain structure of 5nm in size could reduce the core loss within the normally applied magnetic field of 300A/m at 10kHz.

Simulation and Optimization of Penicillin Amidohydrolase Enzyme Reactor System

Ryu,D Y,Lee,B K 한국화학공학회 1973 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.11 No.3

The activity of penicillin amidase obtained from B. megaterium and M. roseus were compared with that obtained from other microbial sources. By using both the soluble and immobilized forms of the enzyme obtained from B. megaterium, we have studied the reaction kinetics. The products of the enzymatic hydrolysis of benzylpenicillin, PAA and 6-APA, have been found to be competitive and noncompetitive inhibitors of the enzyme, respectively. We have developed a kinetic model of the reaction based on this finding and a mathematical model for a continuous enzyme reactor system was formulated. With the aid of a computer, simulation studies of the enzyme reactor systems were carried out, and the results compared favorably with the experimental results. The productivity (defined as moles of product formed per liter of reactor volume per hour) was optimized with respect to the space time of the reactor system and the concentration of the substrate in the feed. It was found that the productivity of the immobilized enzyme reactor system was more favorable as compared with the soluble enzyme reactor system under certain operating conditions.

Modeling and simulation of efficiency droop in GaN-based blue light-emitting diodes incorporating the effect of reduced active volume of InGaN quantum wells

Ryu, H.Y.,Ryu, G.H.,Choi, Y.H.,Ma, B. ELSEVIER 2017 Current Applied Physics Vol.17 No.10

<P>The efficiency droop of InGaN-based blue light-emitting diodes (LEDs) is analyzed using numerical simulations with a modified ABC carrier recombination model. The ABC model is modified to include the effect of reduced effective active volume of InGaN quantum wells (QWs) and incorporated into the numerical simulation program. It is found that the droop of internal quantum efficiency (IQE) can be well explained by the effect of reduced light-emitting active volume without assuming a large Auger recombination coefficient A simulated IQE curve with the modified ABC model is found to fit quite well with a measured efficiency curve of an InGaN LED sample when the effective active volume takes only 2.5% of the physical volume of QWs. The proposed numerical simulation model incorporating the reduced effective active volume can be advantageous for use in the modeling and simulation of InGaN LEDs for higher efficiency. (C) 2017 Elsevier B.V. All rights reserved.</P>

포스터 발표 : 간 ; 장기간 면역억제제 투여후 HBV 증식이 활성화된 Anti-HBc 양성자 1예에서 "a" 결정기의 변이

김영석 ( Y. S. Kim ),김연수 ( Y. S. Kim ),천영국 ( Y. K. Cheon ),유창범 ( C. B. Ryu ),문종호 ( J. H. Moon ),조영덕 ( Y. D. Cho ),이문성 ( M. S. Lee ),심찬섭 ( C. S. Shim ),김부성 ( B. S. Kim ) 대한소화기학회 2002 대한소화기학회 춘계학술대회 Vol.2002 No.-

HBsAg이 음성일지라도 Antii-HBc가 양성인 경우 간조직이나 말초단핵구에서 HBV DNA가 고빈도로 검출되며, 급성 B형 간염으로부터 회복되어 Anti-HBs가 혈청내에 존재하는 경우에도 혈청이나 말초단핵구로부터 장기간 HBV DNA가 검출될 수 있다. 따라서 급성 B형 간염으로부터 완전히 회복된 후에도 일부에서는 저농도의 바이러스 혈중이 지속됨을 의미하며 이는 면역억제제등을 투여시 바이러스 증식이 재활성될 수 있는 잠재성이 있는 상태라 할 수

각종 심질환에서의 방사성 동위원소 심혈관 조영술에 관한 연구

조보연,고창순,정준기,박선양,김병국,류박영 대한핵의학회 1979 핵의학 분자영상 Vol.13 No.1

비관혈적 방법인 방사성동위원소 심혈관조영술 정성적 및 정량적인 분석을 시도하고자 1979년 3월부터 9월까지 서울대학병원에 입원한 각종 심질환환자 147명과 정상대조군 26명을 대상으로 방사성동위원소 심혈관찰영술을 시행하여 다음과같은 결과를 얻었다. 1) 심도자법으로 단락이 확진된 좌우단락 24예중 22예에서 진단할 수 있었고, 심장단락 21예에서는 전예에서 진단이 가능하였다. 방사성 동위원소법으로 좌우단락을 진단할 수 있는 최소의 Qp/Qs비는 1.3이었다. 2) 폐의 시간일방사능유선에서 최대방사능치(C1)와 같은 시간 뒤의 방사능치(C2)의 비 C2/C1는 정상대조군에서는 28.6±4.6%(21∼38%)이었고, 좌우단락에서는 67.8±12.2%로 정상대조군에 비하여 현저히 증가되어 있었다(P$lt;0.01). 3) 좌우단락 8예에서의 폐의 시간일방사능유선을 이용하여 구한 Qp/Qs비는 oxymetry법에 의한 Qp/Qs비와 유의한 상관관계가 있었다(상관계수 0.907, P$lt;0.01). 4) 개심수술후 단락의 교정여부를 방사성동위원소 심혈관조영술로 쉽게 확인할 수 있었다. 이상의 성적으로 방사성동위원소 심혈관조영술은 간단하고 안전하게 심장단락의 정성적 및 정량적인 분석을 할 수 있었으며 그 성적이 심도자법과 비교하여 높은 정확도를 보이고 있음을 알 수 있었고 반복시행이 용이하기 때문에 수술 후의 교정 여부도 쉽게 판정 할 수 있어 임상적으로 크게 유용하다고 생각되었다. Radionuclidd cardiac angiography has distinct advantages in safety, patient comfort, cost and ease of performance. This method offers diagnostic accuracy equivalent to that of cardiac catheterization. By this method the qualitative and quantitative diagnosis of the cardiac shunts are available. Also for it is repeatable tvith ease and more physiologic, it has application in following pre- and post-operative shunt patients. We performed the radionuclide cardiac angiographies in 147 cases of heart diseases and 26 cases of normal group. 1) The detection of left-to-right shunt was possible in 22 of 24 patients, and 2 patients were not diagnosed due to small shunt amount.(Qp/Qs$lt;l. 3) In 21 patients of right-to-left shunt, all were diagnosed by radionuclide cardiac angiography. 2) With the pulmonary time-activity curve, C2/C1 ratio was calculated. In normal control group, a range of C2/C1 ratios of 21∼38% was established with a mean value of 28.6±4.6%. In patients with left-to-right shunts determined by catheterizion data, the range of C2/C1 ratio was 33∼90%, with a mean value of 67.8±12.2%. 3) In 8 cases of left-to-right shunt, Qp/Qs ratios determined by radionuclide cardiac angiography were compaired with those of cardiac catheterization. The correlation coefficient was 0.907. (P$lt;0.001) 4) Postoperative radionuclide cardiac angiographies were clone in 21 cases. 3 of 13 patients with left-to-right shunts were found to have residual shunts. 8 patients with right-to-left shunts were confirmed to have no residual shunt.

Deletion of carotenoid cleavage dioxygenase 4a (CmCCD4a) and global up-regulation of plastid protein-coding genes in a mutant chrysanthemum cultivar producing yellow petals

Jo, Y.D.,Kim, Y.S.,Ryu, J.,Choi, H.I.,Kim, S.W.,Kang, H.S.,Ahn, J.W.,Kim, J.B.,Kang, S.Y.,Kim, S.H. International Society for Horticultural Science ; 2016 Scientia horticulturae Vol.212 No.-

<P>In addition to attracting pollinators and protecting plants from photooxidative damages, carotenoids play important roles in signaling related to plant development and physiological changes through their cleaved derivatives, apocarotenoids. Yellow chrysanthemum flower petals [Chrysanthemum morifolium (Ramat.)] are the result of a deleted or suppressed carotenoid cleavage dioxygenase gene (CmCCD4a). Therefore, investigating the global gene expression patterns in chrysanthemum mutants producing yellow petals represents an appropriate strategy to analyze the effects of signaling mediated by carotenoid derivatives. We compared the transcriptomes of chrysanthemum cultivars producing white petals with purple stripes ('Noble Wine') and its mutant producing yellow petals with purple stripes ('ARTI-Yellow Star'). Read mapping and polymerase chain reaction analysis revealed that CmCCD4a is absent in the ARTI-Yellow Star genome, while at least three CmCCD4a gene family members are actively transcribed in 'Noble Wine' plants. These results indicate that the deletion of CmCCD4a may be responsible for the development of yellow petals in ARTI-Yellow Star flowers. During comparisons of gene expression patterns between Noble Wine and ARTI-Yellow Star, we detected numerous significantly up-regulated plastid protein-coding genes as well as significantly or mildly up-regulated carotenoid biosynthesis genes in ARTI-Yellow Star plants. The up-regulated plastid protein-coding genes belong to a broad range of functional categories related to translation, photosynthesis, reactive oxygen species scavenging, oxidative phosphorylation, transcription, processing, terpenoid metabolism, and chlorophyll metabolism. Our results present a possible relationship between CmCCD4a and regulation of plastid protein-coding genes. (C) 2016 Elsevier B.V. All rights reserved.</P>

Structural and thermal properties of boron nanoparticles synthesized from B₂O₃+3Mg+kNaCl mixture

Yoo, B.U.,Nersisyan, H.H.,Ryu, H.Y.,Lee, J.S.,Lee, J.H. Elsevier [etc.] 2014 Combustion and Flame Vol.161 No.12

Amorphous boron nanoparticles were synthesized by heating a B<SUB>2</SUB>O<SUB>3</SUB>+3Mg+kNaCl (k is the number of moles of NaCl) exothermic mixture in a laboratory oven at 800<SUP>o</SUP>C under argon flow. NaCl was used as inert material to decrease the maximum combustion temperature of the reaction mixture when it was self-ignited after the melting of Mg at 650<SUP>o</SUP>C. The size of the boron nanoparticles extracted from the final product by acid leaching ranged between 30 and 300nm for k values ranging from 1 to 5. Moreover, increasing the value of k from 1 to 5 resulted in an increase in the specific surface area of the nanoparticles from 40 to 74m<SUP>2</SUP>g<SUP>-1</SUP>. However, at k=10, a decrease in the specific surface area to 47.56m<SUP>2</SUP>g<SUP>-1</SUP> was recorded due to incomplete reduction of B<SUB>2</SUB>O<SUB>3</SUB>. The ignition point of boron nanoparticles in air as estimated using a thermocouple was approximately 300<SUP>o</SUP>C. Digital camera recording of the combustion process of boron nanoparticles in air revealed that the burning speed of the nanoparticles increased significantly from 0.3 to 15cm/s when k increased from 1 to 5.