Identification of Five Chitinase Isozymes from S. marcescens

Hwang, Jae Ryoung,Gal, Sang Wan,Lee, Kyeong Ai,Shin, Yong Chul,Cho, Moo Je,Lee, Sang Yeol 慶尙大學校 기초과학연구소 1991 基礎科學硏究所報 Vol.7 No.-

SDS 존재하에서 전기영동을 한 후, substrate activity staining을 한 결과, S. marcescens는 5가지의 chitinase isozyme을 생성함을 알아내었다. 이 효소는 inducible enzyme으로서, 30℃에서 7일간 진탕배양하였을 때 1.5% chitin을 첨가한 LB-배지에서 얻은 효소활성이 chitin을 첨가하지 않은 배지에서 얻은 것보다 약 7배의 효소활성의 증가를 보였다. Chitinase를 최대로 생성시키는 조건에서 S. marcescens를 배양한 후 regenerated chitin을 이용한 친화성 chromatography를 행하여, 이 배양상등액으로부터 5가지의 chitinase isozyme를 분리하였으며 이들의 분자량이 58, 47, 43, 37 및 21 kd임을 확인하였다. 충분히 세척한 chitin column으로부터 chitinase를 elution시키는 방법으로, pH3.3인 완충액을 사용하였을 때, 5가지 chitinases가 모두 용출되었으며, pH를 2.0인 완충액으로 바꾸어 용출시켰더니 5가지 중 분자량이 58, 47, 43 kd인 3가지 chitinase가 더 회수되었다. 또한 Chitinases 의 pH에 대한 안정성을 실험한 결과 S. marcescens가 분비하는 chitinases는 산성조건에서 매우 불안전한 chitinases와 비교적 안정한 chitinase의 두가지 group이 존재함을 알 수 있었다. S. marcescescens KCTC2172 produced five extracellular chitinases that were involved in chitin degradation. These enzymes were identified as chitinase isozymes by substrate activity staining in SDS-PAGE gel after removal of SDS, because chitinases were resistant to SDS and existed as monomeric proteins. Their apparent molecular weights obtained by SDS-PAGE were 58, 47, 43, 37, and 21kd. The chitinase activities were induced about seven folds by the addition of 1.5% chitin to LB-medium compared with those obtained without chitin, and the induction was dependent on the various forms of chitin. Chitinases were purified using the regenerated chitin column by successive pH changes of elution buffer. When the column was eluted with enough volume of pH 3.3 buffer, five chitinase isozymes were eluted. However, three of them whose molecular weights were 58,47 and 43 kd were further eluted by the pH changes of elution buffer from pH 3.3 to 2.0 Considering the pH dependent stability of chitinases, it was known that S. marcescens produced two groups of chitinase isozymes; One is resistant and the other is very sensitive to acidic conditions, at pH below 3.3.

Diclofenac, a Non-steroidal Anti-inflammatory Drug, Inhibits L-type $Ca^{2+}$ Channels in Neonatal Rat Ventricular Cardiomyocytes

Yarishkin, Oleg V.,Hwang, Eun-Mi,Kim, Dong-Gyu,Yoo, Jae-Cheal,Kang, Sang-Soo,Kim, Deok-Ryoung,Shin, Jae-Hee-Jung,Chung, Hye-Joo,Jeong, Ho-Sang,Kang, Da-Won,Han, Jae-Hee,Park, Jae-Yong,Hong, Seong-Geun The Korean Society of Pharmacology 2009 The Korean Journal of Physiology & Pharmacology Vol.13 No.6

A non-steroidal anti-inflammatory drug (NSAID) has many adverse effects including cardiovascular (CV) risk. Diclofenac among the nonselective NSAIDs has the highest CV risk such as congestive heart failure, which resulted commonly from the impaired cardiac pumping due to a disrupted excitationcontraction (E-C) coupling. We investigated the effects of diclofenac on the L-type calcium channels which are essential to the E-C coupling at the level of single ventricular myocytes isolated from neonatal rat heart, using the whole-cell voltage-clamp technique. Only diclofenac of three NSAIDs, including naproxen and ibuprofen, significantly reduced inward whole cell currents. At concentrations higher than $3\;{\mu}M$, diclofenac inhibited reversibly the $Na^+$ current and did irreversibly the L-type $Ca^{2+}$ channels-mediated inward current $(IC_{50}=12.89\pm0.43\;{\mu}M)$ in a dose-dependent manner. However, nifedipine, a well-known L-type channel blocker, effectively inhibited the L-type $Ca^{2+}$ currents but not the $Na^+$ current. Our finding may explain that diclofenac causes the CV risk by the inhibition of L-type $Ca^{2+}$ channel, leading to the impairment of E-C coupling in cardiac myocytes.

Immobilization stress increased cytochrome P450 1A2 (CYP1A2) expression in the ovary of rat

Hwang, Jong-Chan,Kim, Hwan-Deuk,Park, Byung-Joon,Jeon, Ryoung-Hoon,Baek, Su-Min,Lee, Seoung-Woo,Jang, Min,Bae, Seul-Gi,Yun, Sung-Ho,Park, Jin-Kyu,Kwon, Young-Sam,Kim, Seung-Joon,Lee, Won-Jae The Korean Society of Animal Reproduction and Biot 2021 한국동물생명공학회지 Vol.36 No.1

Under the stressed condition, a complex feedback mechanism for stress is activated to maintain homeostasis of the body and secretes several stress hormones. But these stress hormones impair synthesis and secretion of the reproductive hormones, followed by suppression of ovarian function. Cytochrome P450 1A2 (CYP1A2) plays a major role in metabolizing exogenous substances and endogenous hormones, and its expression is recently identified at not only the liver but also several organs with respect to the pancreas, lung and ovary. Although the expression of CYP1A2 can be also affected by several factors, understanding for the changed pattern of the ovarian CYP1A2 expression upon stress induction is still limited. Therefore, CYP1A2 expression in the ovaries from immobilization stress-induced rats were assessed in the present study. The stress-induced rats in the present study exhibited the physiological changes in terms of increased stress hormone level and decreased body weight gains. Under immunohistological observation, the ovarian CYP1A2 expression in both control and the stressed ovary was localized in the antral to pre-ovulatory follicles. However, its expression level was significantly (p < 0.01) higher in the stress-induced group than control group. In addition, stress-induced group presented more abundant CYP1A2-positive follicles (%) than control group. Since expression of the ovarian CYP1A2 was highly related with follicle atresia, increased expression of CYP1A2 in the stressed ovary might be associated with changes of the ovarian follicular dynamics due to stress induction. We hope that these findings have important implications in the fields of the reproductive biology.

Synthesis and magnetic properties of La³⁺-Co²⁺ substituted strontium ferrite particles using modified spray pyrolysis–calcination method

Hwang, Tae-Yeon,Lee, Jimin,Lim, Hyo-Ryoung,Jeong, Seung-Jae,An, Guk-Hwan,Kim, Jongryoul,Choa, Yong-Ho Elsevier 2017 CERAMICS INTERNATIONAL Vol.43 No.4

<P><B>Abstract</B></P> <P>The purpose of the research was to improve the intrinsic magnetic properties of strontium ferrite by substituting lanthanum and cobalt for strontium and iron. The salt-assisted ultrasonic spray pyrolysis (SA-USP) following calcination process were used to from La-Co substituted strontium ferrite particles (La<SUB> <I>x</I> </SUB>Sr<SUB>1-<I>x</I> </SUB>Fe<SUB>12<I>-y</I> </SUB>Co<SUB> <I>y</I> </SUB>O<SUB>19</SUB>), and their compositional dependent magnetic properties systemically investigated. All the samples were calcined at 1050°C for 1h in an air atmosphere to yield single-phased hexagonal particles several hundred nanometers to microns in size. A saturation magnetization of 70.76emu/g and a coercivity 7265Oe were obtained at a composition of La<SUB>0.25</SUB>Sr<SUB>0.75</SUB>Fe<SUB>11.75</SUB>Co<SUB>0.25</SUB>O<SUB>19</SUB>. The amount of Co was reduced to obtain an optimized saturation magnetization of 71.40emu/g and a coercivity of 7572Oe at a composition of La<SUB>0.25</SUB>Sr<SUB>0.75</SUB>Fe<SUB>11.8</SUB>Co<SUB>0.2</SUB>O<SUB>19</SUB>.</P>

Immunohistological expression of cytochrome P450 1A2 (CYP1A2) in the ovarian follicles of prepubertal and pubertal rat

Hwang, Jong-Chan,Park, Byung-Joon,Kim, Hwan-Deuk,Baek, Su-Min,Lee, Seoung-Woo,Jeon, Ryoung-Hoon,Jang, Min,Bae, Seul-Gi,Yun, Sung-Ho,Park, Jin-Kyu,Kwon, Young-Sam,Kim, Seung-Joon,Lee, Won-Jae The Korean Society of Animal Reproduction and Biot 2020 한국동물생명공학회지 Vol.35 No.4

Cytochrome P450 1A2 (CYP1A2) is a member of the cytochrome P450 superfamily enzymes in mammals and plays a major role in metabolizing endogenous hormones in the liver. In recent days, CYP1A2 expression has been found in not only the liver but also other tissues including the pancreas and lung. However, little information is available regarding the expression of CYP1A2 in the ovary, in spite of the facts that the ovarian follicle growth and atresia are tightly associated with controls of endocrine hormonal networks. Therefore, the expression of CYP1A2 in the ovaries of prepubertal and pubertal rats was investigated to assess its expression pattern and puberty-related alteration. It was demonstrated that the expression level of CYP1A2 was significantly (p < 0.01) higher in the pubertal ovaries than prepubertal counterparts. At the ovarian follicle level in both groups, whereas CYP1A2 expression was less detectable in the primordial, primary and secondary follicles, the strongly positive expression of CYP1A2 was localized in the granulosa cell layers in the antral and pre-ovulatory follicles. However, the ratio of CYP1A2-positive ovarian follicle was significantly (p < 0.01) higher in the ovary of pubertal group (73.1 ± 3.1%) than prepubertal one (41.0 ± 10.5%). During the Immunofluorescence, expression of CYP1A2 was mainly localized in Fas-positive follicles, indicating the atretic follicles. In conclusion, these results suggested that CYP1A2 expression was mainly localized at the atretic follicular cells and affected by the onset of puberty. Further study is still necessary but we hypothesize that CYP1A2 expresses in the atretic follicles to metabolize residue of the reproductive hormones. These findings may have important implications for the fields of reproductive biology of animals.

Introduction to Development of KaVA Digital Filter using GPU

Jae-Hwan Yeom,Se-Jin Oh,Duk-Gyoo Roh,Dong-Kyu Jung,Chung-Sik Oh,Hyo-Ryoung Kim,Jae-Sik Shin,Ju-Yeon Hwang,Min-Gyu Song,Tae-Hyun Jung 한국천문학회 2018 天文學會報 Vol.43 No.1

수근관 증후군의 임상 양상과 전기진단검사의 관계

황미령,권희규,이항재 大韓再活醫學會 1999 Annals of Rehabilitation Medicine Vol.23 No.5

소득계층과 주관적 계층인식에 따른 의료이용: 『한국의료패널』자료를 중심으로

최령(Ryoung Choi),박재용(Jae Yong Park),황병덕(Byung Deog Hwang) 한국보건사회학회 2013 보건과 사회과학 Vol.0 No.33

이 연구는 한국보건사회연구원과 국민건강보험공단에서 수집한 한국의료패널(Korea Health Panel) 의 원자료 중 2009년 연간통합데이터를 분석자료로 이용하였다. 의료이용에 영향을 미치는 요인을 파악하기 위하여 다중 회귀분석을 실시하였고, 계층요인과 건강상태요인에 따른 영향을 좀 더 명확하게 분석하기 위하여 Model 1,2,3을 개발하였다. 외래의료비의 경우 소득계층과 주관적 계층인식이 낮을수록, 연령이 낮을수록, 외래와 입원상병진단을 받을수록 의료비지출이 높았으며, 입원의료비의 경우 배우자가 있는 경우, 사업주 및 자영업자, 임금근로자에 해당하지 않는 경우, 경제적인 어려움으로 인한 스트레스를 받는 경우, 입원진단상병을 받은 경우 의료비 지출이 높은 것으로 분석되었다. 이러한 결과는 상위계층에 비해 하위계층의 의료이용과 의료비 지출이 상대적으로 증가하고 있다는 것으로 의료보장의 목적에 바람직한 일이라고 할 수 있지만, 한편으로는 하위계층일수록 주관적 건강상태가 나빠지고, 급여 및 비급여 의료비부담률 등이 증가하고 있는 것으로 판단된다. 객관적 지위가 되는 소득계층뿐만 아니라 일상적인 삶에서 생활양식과 나와 남을 처지를 구분하는 주관적 계층인식에 따른 범주형 분석을 시행하고 의료이용에 미치는 영향을 비교 분석함으로써 소득계층뿐만 아니라 주관적 계층인식에 따른 건강보험의 보장성 강화, 의료보장정책 및 전달체계, 서비스, surveillance 등 보건의료서비스 체계개발이 필요할 것이다. The study used the ‘2009 annual total data as an analysis material among other raw data of Korea Health Panel collected by Korea Institute for Health and Social Affairs and National Health Insurance Corporation. In order to understand causing factors to the medical use, the multiple regression analysis was conducted with Model 1, 2 and 3 designed to get social stratification factors and health condition factors analyzed even more thoroughly. In terms of the outpatient medical expenses, more money would be spent on the medical service as the perceptions of income class and subjective income class are low, as the age is low, and as the outpatient care and inpatient diagnosis are frequent. Regarding the inpatient medical expenses, more money would be spent as a patient has a spouse, as the patient is not regarded as a business owner, an owner-operator and a paid worker, as the patients get stressed by financial difficulties and lastly as the patient gets diagnosed while in hospital. As the results confirmed, it is good to see how the purposes of the medical security are being satisfied here while more medical uses and more medical expenses spending are conducted by the lower class than the upper class. However, at the same time, the results also argued that subjective health conditions of the lower class are getting worse constantly and that such phenomenon would, in return, increase the paid and unpaid medical benefit rates and others. In order to deal with such problems, a categorical analysis should be conducted not only on the income class, the objective position, but also on the regular life styles and the subjective income class perception that would distinguish one’s own situations from others. Not only that, with results from the categorical analysis, health and medical care system such as health insurance guarantee, medical social security and information delivery system, service and surveillance shall be developed.

Preparation and Characterization of Metal-Ceramic Nanocomposite for High Frequency Application

Seung-Jae Jung,Hyo-Ryoung Lim,Tae-Youn Hwang,Yong-Ho Cho 한국자기학회 2015 한국자기학회 학술연구발표회 논문개요집 Vol.2015 No.11

Three-dimensional hierarchical Te-Si nanostructures.

Lim, Jae-Hong,Shin, Gyeong-Jin,Hwang, Tae-Yeon,Lim, Hyo-Ryoung,Lee, Young-In,Lee, Kyu-Hwan,Kim, Sung-Dae,Oh, Min-Wook,Park, Su-Dong,Myung, Nosang V,Choa, Yong-Ho RSC Pub 2014 Nanoscale Vol.6 No.20

<P>Three-dimensional hybrid nanostructures (i.e., Te 'nanobranches' on a Si 'nanotrunk' or Te 'nanoleaves' on a Si 'nanotrunk') were synthesized by combining the gold-assisted chemical etching of Si to form Si 'nanotrunks' and the galvanic displacement of Si to form Te 'nanobranches' or 'nanoleaves.' By adjusting the composition of the electrolyte used for the galvanic displacement reaction, the shape of the Te nanostructures could be changed from nanoleaves to nanobranches. The Si nanotrunks with Te nanobranches showed stronger luminescent emission in the visible region, with their Raman spectrum having a higher wave number, owing to their grain size being larger. This suggested that the optical and photoelectrochemical properties of Te-Si hybrid nanostructures depend on their shape and size. Using this approach, it should be possible to fabricate various hierarchical nanostructures for use in photoelectronic and photoelectrochemical devices.</P>