Disruption of rsmA Gene of Pectobacterium carotovorum subsp. carotovorum LY34 and Effect on Pathogenicity

Kim, Min Keun,Kang, Tae Ho,Kim, Sung Kyum,Jeong, Yu Seok,Yun, Han Dae,Kim, Hoon The Korean Society for Applied Biological Chemistr 2012 Applied Biological Chemistry (Appl Biol Chem) Vol.55 No.6

The rsmA gene was cloned from soft-rot bacterium Pectobacterium carotovorum subsp. carotovorum LY34 (Pcc LY34), and its role in pathogenicity was investigated by marker exchange mutagenesis. From a cosmid library of Pcc LY34 genomic DNA, a positive clone carrying the rsmA gene was selected, and the gene was cloned by polymerase chain reaction (PCR) amplification. The gene is 186 bp in size and encodes a protein of 62 amino acids with a predicted molecular mass of 6,839 Da. The calculated pI of the RsmA is 8.16. The phylogenetic tree showed that the RsmA of Pcc LY34 appeared genetically identical to the CsrA of Pectobacterium atrosepticum SCRI1043 (100% identity) and similar to the CsrA of Yersinia pestis KIM10+(98.3%). The gene was disrupted by the $Km^r$ gene, and the cells became mutated (i.e., $RsmA^-$ mutant). The pathogenicity test revealed that the disease rating of the $RsmA^-$ mutant only differed slightly from that of the wild type on a slice of potato tuber and a Chinese cabbage stalk. These results suggest that RsmA is not an essential factor for the pathogenicity of Pcc LY34 and that the rsmA gene of Pcc LY34 is not completely derepressed in the $RsmA^-$ mutant for virulence-related genes, contrary to the results of Erwinia carotovora subsp. carotovora $RsmA^-$ mutant, which proved hypervirulent for celery petioles. These results showed that the microenvironmental conditions of the host and/or strain of pathogen are important for the coordination of virulence gene expression.

K-식(式) 침전관(沈澱管)에 의한 간질충란(肝蛭蟲卵) 간이검사법(簡易檢査法)

김교준,김상근,허민도,Kim, Kyo-Joon,Kim, Sang-Keun,Hu, Min-Do 대한수의학회 1983 大韓獸醫學會誌 Vol.23 No.1

The studies carried out to investigate the detection method of Fasciola eggs from positive cattle feces in the intradermal reaction method with laborsaving composition of sieves and Kim's sedimental tube method. The results obtained are summarized as follows: 1. The detection method of Fasciola eggs was improved by 3 meshes (100mesh, 150mesh, 250mesh) for filteration of fecal fluid contained Fasciola eggs. 2. Third type of tube in the 3 kinds of sedimental tube had the highest recovers rate of Fasciola eggs. Thus, this type of tube was selected and called as Kim's sedimental tube. 3. A-II, A-III, B-III and C-III type by Kim's sedimental tube method had the recovery rates of eggs in the 1st drop as ranged 99 to 100% and, A-I, B-II, C-II as 71 to 91%. 4. These Type of tubes were useful to detect Fasciola eggs and to shorten the time of the diagnostic procedures. 5. The Kim's sedimental tube method showed high recovery rates and convenient procedures as compared with other detection methods reported. In addition, the EPG value can also be obtained by this method. Therefore, it is desirable that the Kim's sedimental tube method could be recommended to clinicians.

K-식(式) 침전관(沈澱管)에 의한 간질충란(肝蛭蟲卵) 간이검사법(簡易檢査法)에 관한 연구(硏究)

김교준,김상근,허민도,Kim, Kyo Joon,Kim, Sang Keun,Hu, Min Do 충남대학교 농업과학연구소 1982 Korean Journal of Agricultural Science Vol.9 No.2

피내반응법(皮內反應法)에 의(依)해 간질(肝蛭) 양성반응(陽性反應)으로 판정(判定)된 유우(乳牛)를 대상(對像)으로 분편검사(糞便檢査)를 실시(實施)하여 충란(蟲卵)을 확인(確認)한 후(後), 현재(現在) 사용(使用)되고 있는 간질(肝蛭) 충란검사법(蟲卵儉査法)들의 단점(短點)을 개선(改善)하기 위하여 잔재물(殘滓物)을 성력적(省力的)으로 제거(除去)하는 사(篩)의 조합법(組合法)과 K-식(式) 침전관(沈澱管)을 고안(考案)하여, 인위적(人爲的)으로 분즙(糞汁)에 충란(蟲卵)을 혼입(混入)하여 K-식(式) 침전관법(沈澱管法)에 따라 검사(檢査)한 결과(結果) 현재(現在)까지 보고(報告)된 타방법(他方法)들에 비(比)하여 조작(操作)이 간편(簡便)하고 검출율(檢出率)도 높아 이상적(理想的)인 방법(方法)으로 사료(思料)되었기에 그 개요(槪要)와 결과(結果)를 보고(報告)하는 바이다. 1. 간질충란(肝蛭蟲卵)을 여과(慮過)하고 잔재물(殘滓物)을 제거(除去)하기 사(篩)의 조합(組合)을 3단계(段階)(100mesh, 150mesh, 250mesh)로 조합(組合)하여 성력적(省力的)인 방법(方法)으로 개선(改善)하였다. 2. 3종(種)의 침전관중(沈澱管中) 제(第)III형(型)의 침전관(沈澱管)에 의(依)한 간질충란(肝蛭蟲卵) 회수율(回收率)이 가장 높았으므로 제(第)III형(型)을 K-식(式) 침전관(沈澱管)으로 지칭(指稱) 채택(採擇)하였다. 3. K-식(式) 침전관법(沈澱管法)에서 A-II, A-III, B-III, C-III형(型)의 1구(回) 경검성적(鏡檢成績)은 99~100%였으며 A-I, B-II, C-I 및 C-II형(型)은 71~91%였다. 4. A형(型)($5m{\ell}$, 5-10침전(沈澱)), B형(型)($10m{\ell}$, 10-10침전(沈澱)) 및 C형(型)($15m{\ell}$, 15-15침전(沈澱))은 각기(各其) 특징(特徵)을 가진 방법(方法)들로서 판정시간(判定時間)을 단축(短縮)하는데는 A형(型)이 가장 유용(有用)한 방법(方法)이었다. 5. K-식(式) 침전관법(沈澱管法)은 다른 검출법(檢出法)에 비(比)하여 가장 검출율(檢出率)이 높은 간편(簡便)한 방법(方法)이었으며 E. P. G가(價)도 동시(同時)에 얻을 수 있는 이상적(理想的)인 방법(方法)으로서 임상응용가치(臨床應用價値)가 매우 높은 것으로 사료(思料)되었다. These studies were carried out to investigate of detection of Fasciola egg from positive cattle faces in the intradermal reaction method by laborsaving composition of sieves and Kim's sedimental tube method. The results obtained are summerized as follows: 1. Detection method of Fasciola eggs was improved by 3 meshes(100mesh, 150mesh, 250mesh) for filtration of fecal fluid contained Fasciola eggs. 2. III type of tube in the 3 kinds of sedimental tube had the highest recovery rate of Fasciola egg. Thus, this type of tube was selected and called as Kim's sedimental tube. 3. A-II, A-III, B-III and C-III type by Kim's sedimental tube method had the recovery rates of eggs in the 1st dropping as ranged 99 to 100% and A-I, B-II, C-I and C-II as 71 to 91%. 4. All types as themselves contained the special aspects. In the these type was useful to determine the results in the urgent cases add to shorten the time of the diagnostic procedures. 5. Kim's sedimental tube method high recovery rate and convenient procedures as compared with other detection methods reported. In addition, through this method can also obatained E. P. C. value. Therefore, it is desirable that Kim's sedimental tube method be recommended by clinicians.

생체분해성 고분자를 이용한 사시수술용 제형개발 및 효용성에 대한 연구

민병무,김용백,김승영,김창식,박근성,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

A new device, muscle clamping system was developed to facilitate exact quatifying technique A strabismus surgery, and reduce the risk of complications. The device is composed of a lower fixing body with three jaws and an upper supporting body. They are used to clip an extraocular muscle and fix it to the sclera with a single bite. Superior rectus recession on 16 rabbit eyes were performed with this new device. Conjunctival injection, muscle adhesion strength, and light microscopic findings were examined at 1, 2, 4 and 8 weeks postoperatively. The Conjunctival injection were minimal, adhesion power ranged from 420 to 600 gram gravity, which is sufficient in withstand the normal pull of human extraocular muscle. In microscopic exam, some Inflammatory cells and fibrosis were found. The new device was technically easy, fast, and accurate, so it may be useful in stabismus surgery.

생체분해성 망막압정을 이용한 망막고정에 대한 실험적 연구

김용백,민병무,김창식,박근성,김승영,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

Biodegradable retinal fixation devices obtain mechnical fixation of the retina with desirable chorioretinal scarring and with the potential for local, sustained release of antimetabolites and steroids to inhibit proliferative vitreoretinopathy. We manufactured a biodegradable retinal tack with barb that was designed in order to prevent intrusion from implantation of retinal tacks. This study was carried to evaluate the efficacy for retinal fixation and the capability for sustained release of drugs with a newly designed biodegradable retinal tack Biodegradable retinal tacks were made of polymers of glycolic acids and were designed with barbs in a shape to prevent the disinsertion. Biodegradale retinal tacks are divided into 3 parts, a conical portion that is inserted into the sclera, a cylinder portion that remains in the vitreous, and a neck portion between the pin and the cylinder. The tapered conical end was manufactured to allow easy insertion through the retina and choroid into the sclera. A cylinder portion was manufactured with a tapered angle that fixes firmly into the orifice of 19 gauge spinal needle. A neck portion, 0.4 mm in diameter, was designed to prevent disinsertion from following implantation of retinal tack. The applicator was a 19 gauge spinal needle and its orifice was prepared to 15°angle to accept the tapered cylinder portion of the retinal tack. The retinal tacks, secured in the needles, were passed through the formed vitreous and inserted into the retina, choroid, and sclera and were released by pushing the internal needle, usually within 2-3mm of the medullary ray of the posterior rabbit retina A retinal tack was placed in each of 8 pigmented rabbit eyes. Slit-lamp biomicroscopy, indirect ophthalmoscopy and fundus photography were performed periodically from 1 day to 8 weeks after surgery. Eight eyes were enucleated and studied by light microscopy at 8 weeks. Biomicroscopic evaluation of the animals revealed edemas adjacent to the retinal surfaces immediately after insertion of the biodegradable retinal tacks in all the animals. These edemas disappeared after 1 week. The first noticeable change in the size of retinal tacks was shown after 2weeks. The size of the retinal tacks gradually got smaller, decreasing to about one-half at 4 weeks and about one-third at 8 weeks. All retinal tacks remained in inserted places without any movement for an 8 week period. On light microscopy, epiretinal proliferations were seen to extend into the vitreous cavity. Cellular capsules that lined the inner aspect of the scleral defect caused by tack insertion were found. However the adjacent retina had a normal cytologic appearance and architecture in all specimens. We manufactured a biodegradable retinal tack that is designed to prevent intrusion from implantation of retinal tacks. All biodegradable retinal tacks reduce in size with time, but no retinal tacks extruded from the inserted place. The newly designed biodegradable retinal tack can be used for retinal fixation and may be used as a vehicle for the introduction of pharmacologic agents to prevent the cellular events that promote proliferative vitreoretinopathy.

Effects of hydrogen plasma treatment on SnO2:F substrates for amorphous Si thin film solar cells

Min-Seung Choi,Young-Ju Lee,Jung-Dae Kwon,Yongsoo Jeong,Ju-Yun Park,강용철,Pung Keun Song,Dong-Ho Kim 한국물리학회 2013 Current Applied Physics Vol.13 No.8

We investigated the effects of hydrogen plasma treatment on the physical and electrical properties of fluorine-doped tin oxide (FTO) films used for amorphous silicon (a-Si) thin film solar cells. A slight increase in carrier concentration by the hydrogen doping effect was observed for the FTO film exposed to the hydrogen plasma for 5 min. For further exposure to the plasma, the chemical reduction became prominent and resulted in deterioration of the electrical and optical properties of the film. XPS analysis revealed that the chemical reduction of SnO2 to Sn metallic state occurs on the surface region. It was found that the defects formed by hydrogen plasma act as recombination centers at the interface between FTO electrode and p-layer of a-Si solar cells. This phenomenon resulted in the deterioration of the cell performance. The averaged conversion efficiency (6.82%) of the cells on pristine FTO hydrogen substrate was decreased to 5.81% for the cells on FTO treated for 5 min, which is mainly attributed to the decrease in short-circuit current density.

난치성 전두엽 간질의 외과적 치료

김정목,김형일,김근수,김철진,이정청,이민철 대한신경외과학회 1996 Journal of Korean neurosurgical society Vol.25 No.11

Recent advances of neuroimaging and electrophysiological monitoring technique have contributed in improving the surgical outcome of frontal lobe epilepsy. The authors have analysed 36 consecutive cases of intractable frontal lobe epilepsy that were treated at our institute between September. 1992 and December, 1995 to determine the clinical, electrophysiological, and neuroimaging characteristics as well as to delineate the efficacy of surgical treatment in improving the seizure outcome. The patients consisted of 19 males and 17 females. The mean age of the seizure onset and the mean duration of epilepsy were 14.9 and 11.6 years, respectively. Magnetic resonance imaging(MRI) showed no lesion in 9 patients and pathological lesions in 27 patients. The types of the lesions observed included primary brain tumor, mostly low-grade glioma in 10 patients, cortical dysplasia in 4, posttraumatic scar in 4, neocortical gliosis in 3, cyst in 3, and postencephalitic atrophy in 3. Intracranial recordings were performed in 23 cases to determine the epileptogenic zone. The surgical outcome was graded according to Engle’s Classification as Class A in 20 patients. Class B in 2, Class C in 9, and Class D in 5. The surgical outcome was promising regardless of the presence or the absence of the lesion on MRI, invasive recording, age of seizure onset, and duration of epilepsy.

AHP를 이용한 CT 및 MRI의 비용편익분석

조근태,김성조,김성민,김용우,김성재,조용곤 한국경영과학회 2004 經營 科學 Vol.21 No.2

The imports of used medical equipment such as CT, MRI have been rapidly increased every year. How to manage those medical equipment has been one of critical issues in the government sector. In this study, we demonstrate how benefit/cost analysis using the Analytic Hierarchy Process (AHP) can be applied to the comparison of used CT/MRI and new CT/MRI. The final results show that the new CT/MRI is more attractive than the used CT/MRI.

Effect of spark plasma sintering conditions on the thermoelectric properties of (Bi_0.25Sb_0.75)₂Te₃ alloys

Lim, Sang-Soon,Kim, Ju-Heon,Kwon, Beomjin,Kim, Seong Keun,Park, Hyung-Ho,Lee, Ki-Suk,Baik, Jeong Min,Choi, Won Jun,Kim, Dong-Ik,Hyun, Dow-Bin,Kim, Jin-Sang,Baek, Seung-Hyub Elsevier 2016 JOURNAL OF ALLOYS AND COMPOUNDS Vol.678 No.-

<P><B>Abstract</B></P> <P>As a field-assisted technique, spark plasma sintering (SPS) enables densification of specimens in a very short period of time compared to other sintering techniques. For high performance thermoelectric material synthesis, SPS is widely used to fabricate nanograin-structured thermoelectric materials by rapidly densifying the nanopowders suppressing grain growth. However, the microstructural evolution behavior of thermoelectric materials by SPS, another important process during sintering, has been rarely studied. Here, we explore SPS as a tool to control the microstructure by long-time SPS. Using p-type (Bi<SUB>0.25</SUB>Sb<SUB>0.75</SUB>)<SUB>2</SUB>Te<SUB>3</SUB> thermoelectric materials as a model system, we systematically vary SPS temperature and time to understand the correlations between SPS conditions, microstructural evolution, and the thermoelectric properties. Our results show that the relatively low eutectic temperature (∼420 °C) and the existence of volatile tellurium (Te) are critical factors to determine both microstructure and thermoelectric property. In the liquid-phase sintering regime, rapid evaporation of Te leads to a strong dependence of thermoelectric property on SPS time. On the other hand, in the solid-phase sintering regime, there is a weak dependence on SPS time. The optimum thermoelectric figure-of-merit (Z) of 2.93 × 10<SUP>−3</SUP>/K is achieved by SPS at 500 °C for 30 min. Our results will provide an insight on the optimization of SPS conditions for materials containing volatile elements with low eutectic temperature.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Spark plasma sintering (SPS) is used to synthesize the thermoelectric (Bi<SUB>0.25</SUB>Sb<SUB>0.75</SUB>)<SUB>2</SUB>Te<SUB>3</SUB>. </LI> <LI> Liquid phase and volatile element are a key for the microstructure and thermoelectric property. </LI> <LI> Thermoelectric figure-of-merit of 2.9 × 10<SUP>−3</SUP>/K is achieved at 500 °C for 30 min. </LI> </UL> </P>

Structural and biochemical basis for the inhibition of cell death by APIP, a methionine salvage enzyme

Kang, Wonchull,Hong, Se Hoon,Lee, Hye Min,Kim, Na Yeon,Lim, Yun Chan,Le, Le Thi My,Lim, Bitna,Kim, Hyun Chul,Kim, Tae Yeon,Ashida, Hiroki,Yokota, Akiho,Hah, Sang Soo,Chun, Keun Ho,Jung, Yong-Keun,Yang National Academy of Sciences 2014 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.111 No.1

<P>APIP, Apaf-1 interacting protein, has been known to inhibit two main types of programmed cell death, apoptosis and pyroptosis, and was recently found to be associated with cancers and inflammatory diseases. Distinct from its inhibitory role in cell death, APIP was also shown to act as a 5-methylthioribulose-1-phosphate dehydratase, or MtnB, in the methionine salvage pathway. Here we report the structural and enzymatic characterization of human APIP as an MtnB enzyme with a <I>K</I><SUB><I>m</I></SUB> of 9.32 μM and a <I>V</I><SUB><I>max</I></SUB> of 1.39 μmol min<SUP>−1</SUP> mg<SUP>−1</SUP>. The crystal structure was determined at 2.0-Å resolution, revealing an overall fold similar to members of the zinc-dependent class II aldolase family. APIP/MtnB exists as a tetramer in solution and exhibits an assembly with <I>C4</I> symmetry in the crystal lattice. The pocket-shaped active site is located at the end of a long cleft between two adjacent subunits. We propose an enzymatic reaction mechanism involving Glu139* as a catalytic acid/base, as supported by enzymatic assay, substrate-docking study, and sequence conservation analysis. We explored the relationship between two distinct functions of APIP/MtnB, cell death inhibition, and methionine salvage, by measuring the ability of enzymatic mutants to inhibit cell death, and determined that APIP/MtnB functions as a cell death inhibitor independently of its MtnB enzyme activity for apoptosis induced by either hypoxia or etoposide, but dependently for caspase-1-induced pyroptosis. Our results establish the structural and biochemical groundwork for future mechanistic studies of the role of APIP/MtnB in modulating cell death and inflammation and in the development of related diseases.</P>