• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.23-23
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• 2003

Chestnut blight, caused by Cryphonectria parasitica, is the most destructive disease of American and European chestnut trees. A total of 672 C prasitica was isolated from blight lesion on chestnut twigs, which were collected from major chestnut plantations all over Korea in 1999. Isolation rates were over 30% in Kyunggj-, Kyongnam-, and Chonnam-do. The highest isolation rate was 37.4% and recorded in Kyongnam-do. On the other hand, Chonbuk-do had the lowest isolation rate as 13.5%. In grouping of C parasitica by colony shape and color, yellow colony with irregular margin were the most dominant colony type with a frequency of 65.2%. When the 672 isolates were inoculated on the chestnut twigs, 380 isolates (56.5%) caused lesions larger than the standard virulent isolate EP155-2, while 158 isolates (23.4%) caused smaller lesions than the standard hypovirulent isolate UEP-1. In Bavendamm test that determines phenol oxidase activity, 97.1% of all the isolates resulted the same or darker discoloration than EP155-2, and only 12.2% resulted the same or lighter discoloration than UEP-1. In the vegetative compatibility (VC) tests, total 670 isolates were divided into 121 VC groups (VCGs). Kyongnam-, Chonnam-, and Chungnam-do, the three principal chestnut plantation area, had 49, 33, and 27 VCGs, respectively. Among the VCGs, the biggest VCG, KR-VC104, was composed of 164 isolates and the second biggest VCG had 62 isolates. But, 64 of 121 VCGs consisted of sole member. More than 65.8% of KR-VC104, was isolated from the three provinces, Kyongnam-, Kangwon-, and Chungbuk-do. In KR-VC104, 62.8%, 59.1%, and 85.9% of the isolates looked like virulent in colony type, pathogenicity test, and Bavendamm test. In ds-RNA detection tests using cellulose chromatography, 77 of total 650 isolates were ds-RNA positive and detected ds-RNA segments were approximately 12kb, 3kb, 2.7kb, 2kb, and 1.8kb in size. Among the 77 isolates, 46 isolates had 12kb and 25 isolates had 12kb and 2.7kb. Other 6 Isolates had small ds-RNA segments. Kyongnam-, Chonnam-, and Chungnam-do had 43, 16, and 5 ds-RNA positive isolates, respectively. Among the 121 VCGs, only 29 VCGs had ds-RNA positive isolates.(중략)

• Korean Journal of Microbiology
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• v.38 no.1
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• pp.7-12
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• 2002

The intergenic spacer (IGS) region of the ribosomal DNA of species in Fusarium section Liseola was analyzed by amplification and subsequent digestion with several restriction enzymes. The length of the amplified IGS region was about 2.6 Kb in all strains except F.moniliforme 12 Which was about 2.9 Kb. The enzymes, EcoRI, HincII, SalI, HindIII, PstI and SmaI, digested the IGS region and nine haplotypes were identified among 11 strains. In the dendrogram based on PCR-RFLP of IGS region combined the results of section Liseola in this study and section Elegans in previous study, variation in the IGS appears to offer considerable potential to resolve intraspecific relationship as well as interspecies or intersection.

• Journal of the Mineralogical Society of Korea
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• v.3 no.1
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• pp.1-6
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• 1990

Clacic amphiboles along the tremolite (Tr)-tschermakite(Ts) joint were synthesized using a piston-cylinder appratus. At 750-85$0^{\circ}C$and 12-2 kb, amphibole+corundum coexist with zoisite($\pm$talc, chlorite, and Mg-staurolite), but with anorthite($\pm$cholorite, spinel, pyroxenes, and sapphirine) at lower P. At 90$0^{\circ}C$, amphibole+corundum+clinopyroxene($\pm$anorthite, forsterite, sapphirine, and garnet) are stable over the P range 12-18 kb. These amphibole-bearing assemblages are replaced at high P by clcinopyroxene+talc+chlorite+zoisite at 650-75$0^{\circ}C$, and at higher temperatures by garnet+clinopyroxene($\pm$zoisite, orthopyroxene, and Mg-staurolite). Synthetic amphiboles with Ts>~45 mol% contain as much as 0.15 excess cations per formula unit(pfu) based on 23 oxygens(anhydrous formula), whereas less tschermakitic ones are deficient in cation occupancy by up to 0.18 pfu. This trend is attributed to the 야/trioctahedral substitution in Ca-amphiboles. Compositions of synthetic amphiboles display systematic changes with P and T governed by coexisting mineral assemblages. The Ts content (=[8-Si-Na]/2) increases with increasing T( Ts/ T=~0.1 nik% K-1) in the range 750-85$0^{\circ}C$, but remains nearly constant at 850-90$0^{\circ}C$. Pressure dramatically affects the Ts content of Ca-amphiboles:it increases with P at 8-12 kb( Ts/ T=2-3 mol% K-1), but significantly decreases at 12-21 kb( Ts/ P=-2.5 mol% Kb-1). Hence, the most tschermakitic amphiboles, containing 60$\pm$5 mol % Ts, or 1.2$\pm$0.1 tetrahedral Al, occur at 12 kb and 850-90$0^{\circ}C$. Compositions of Ca-amphiboles defined by a simple reaction, 3 Tr+2 zoisite+7 corundum+H2O=5 Ts, are reversed and used to estimate thermodynamic parameters of tschermakite assuming ideal mixing of Tr-Ts solid solutions. Predicted standard molal entropy and enthalpy of tschermakite are : S$^{\circ}$of Tr-Ts solid solutions. Predicted standard molal entropy and enthalpy of tschermakite are : S$^{\circ}$=566.9$\pm$13.7 J mol-1K, -1and H$^{\circ}$=-12518.36$\pm$15.17 kJ mol.-1

• YAKHAK HOEJI
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• v.42 no.5
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• pp.507-512
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• 1998

In the course of developing novel antitumor intercalating agents. We synthesized 4-carbamoyloxymethyl-l-azaanthraquinones 7-12, incorporating the latent alkylating functi onality. These compounds were designed to explore the effect of substituent on the nitrogen of carbamate. The target compounds were prepared by hetero Diels-Alder reaction as a key step followed by functionalization of benzylic methyl to the desired substituents. Growth inhibitory studies of the azaanthraquinones were conducted in vitro against human cancer cell lines (SNU-354; liver and MCF7; breast) and human epidermoid carcinoma cells that are sensitive (KB-3-1) and multidrug-resistant (KB-V-1). The compounds were less potent than doxorubicin against sensitive cell lines. However, the most active compound 12 was not cross-resistant with doxorubicin against KB-V-1.

• The Journal of Korean Society of Virology
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• v.29 no.4
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• pp.261-269
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• 1999

The relationship between second messenger cGMP and human cytomegalovirus (HCMV) replication was investigated. First, the intracellular level of cGMP ([cGMP]i) in HCMV-infected cells was measured. The [cGMP]i increased at early times after HCMV infection, reached maximum level at 12 hr and returned to basal level at 24 hr after virus infection, while [cGMP]i in mock-infected cells remained relatively unchanged. Increasing [cGMP]i resulted in enhanced transcription of HCMV major immediate early gene. For early gene expression, cGMP had varying effect. Expression of 1.2 kb RNA decreased and 2.2 kb RNA increased with increasing cGMP, while 2.7 kb RNA gene expression was not affected. HCMV early genes are regulated by immediate early gene, and the effect of cGMP on the regulatory effect of major immediate early gene on early genes was investigated. In the absence of cGMP, major immediate early gene repressed 2.7 kb RNA gene expression, while 1.2 kb RNA and 2.2 kb RNA early genes were not significantly affected. In the presence of $1\;{\mu}M$ cGMP, however, major immediate early gene stimulated the expression of three early genes.

• Korean Journal of Microbiology
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• v.35 no.3
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• pp.197-204
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• 1999

A total of 22 Leptospiua inlermgans field isolates from the ~ a t s captured in 5 provinces of Korea in 1996, and 6 antigenically closely related relerence serovars of lai, yeonchon, birkini. gem, mwogolo. and canicola were analysed. When the antigenic characteristics were analysed by reactivity with 7 monoclonal antibodies prepared with sh.ains belongng to serogroup Icterohaemorrhagiae. all 22 isolates showed the same reaction pattern with that of serovar lai. Large restriction fragment patterns obtained after cleavage of geno~nic DNAs with infrequently cuttimg restriction enzymes were analyzed by pulsed-field pel electrophoresis(PFGE). Identification of leptospira strains by PFGE with Nor I, Asc I or Iise I digests correlated with their antigenically typed serovars, silh a few exceptions. PFGE of isolates, except for JR89, digested wjth Nor I showed identical pattern w~th serovar lai, showing 13 Cragments between 940 kb and 63 kb. When PFGE pallerns of JR89 were compared with those of serovar lai, Not I digest showed additional two hands of 1000 kb and 460 kb, while Asc I digest showed 650 kb fragment and Fse I digest did not show the fragment of 280 kb. Whereas serovar yeonchon. which was isolated in Korea and identified as a new serovar previously. could be differentiated from serovar lai in antigenic reactivities with monoclonal antibodres. it showed the similar PFGE pattern with serovar lai includin~ reference and field isolates. It was suggested that Korean leptospiral field isolates are closely related in DNA level.

• The Journal of the Korean dental association
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• v.37 no.7 s.362
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• pp.517-529
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• 1999

본 연구는 태령 19일된 백서 태자 두 개관에서 분리한 골모세포유사세포에 화학발암물질인 7,12-Dimethylbenz(a)anthracene (DMBA: 0.5 ㎍/ml) 및 tumor promotor인 12-O-tetradecanoyl-phorbol-13-acetate (TPA; 1.0 ㎍/ml)를 단독 혹은 복합 처리하여 PTRCC-DMBA, RCC-DMBA 및 RCC-DMBA-TPA 세포주를 확립시키고, 각 세포의 세포형태, 세포성장곡선, alkaline phosphatase와 acid phosphatase 활성 및 in vitro tumorigenicity를 연구하였다. 또한 c-myc, c-랜, c-jun, p53 및 Rb 유전자의 발현변화와 항암단백질인 p53 및 pRb 단백질의 발현변화를 관찰하여 골모세포유사세포가 악성형질전환되는 분자기전의 일단을 연구하고자 시행하였다. 본 실험에 사용한 모든 세포군에서 높은 aikaline phosphatase 활성과 낮은 acid phosphatase/alkaline phosphatase ratio를 보여 골모세포의 특성을 나타내었다. RCC-DMBA와 RCC-DMBA-TPA 세포는 정상세포나 PTRCC-DMBA에 비해 빠른 성장속도를 보였으며, 또한 SOFT AGAR상에서 colony를 형성하여 anchorage-independent growth를 나타내었다. 화학발암 물질로 악성변형된 세포들은 정상세포나 PTRCC-DMBA 세포에 비해 c-myc 유전자의 과발현이 관찰되었다. 정상세포에서 p53 유전자의 발현은 1.9 kb의 message만이 발현되었다. 그러나 화학발암물질로 형질전환된 세포에서는 1.9 kb message외에도 1.6 kb의 message가 더 발현되었으며, message의 양도 현저히 증가되었다. p53 단백질의 발현은 RCC-DMBA-TPA 세포에서 정상세포에 비해 현저히 감소하였으나, RCC-DMBA 세포에서는 유사한 경향을 보였다. Rb 유전자의 발현은 RCC-DMBA-TPA 세포에서만 현저히 감소하였으나, Rb 단백질의 발현은 정상세포에 비해 형질전환된 세포들에서 모두 현저히 감소되었고, 특히 RCC-DMBA-TPA 세포에서는 거의 발현되지 않았다. 이상의 결과에서 백서 태자 두 개관에서 분리한 골모세포유사세포는 화학발암물질인 DMBA에 의해 악성형질전환이 유도되었으며, c-myc의 과발현 및 p53과 Rb 단백질의 발현감소가 정상 골모세포유사세포의 악성변형과정에 밀접히 연관되어 있음을 시사한다.

• The Plant Pathology Journal
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• v.15 no.3
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• pp.152-157
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• 1999

An antibiotic compound was isolated from the culture of an antagonist against Fusarium oxysporum f. sp. sesami, Bacillus polymyxa strain KB-8, and tested for the control of Fusarium wilt of sesame in greenhouse conditions. Optimum conditions for culturing the antagonist to obtain the maximum antibiotic activity were determined using different culture media, initial medium acidity, and incubation periods for which yeast -malt extract agar with the initial acidity of pH 5 and over 13 days culture were best. Antibiotic substances extracted by methanol had 2 main fractions, KB-8A and KB-8B, in thin layer chromatography (OLC) with Rf values of 0.35 and 0.67 in a solvent system of chloroform : methanol = 7 : 3. The fraction KB-8A wa purified further by XAD-2, silica gel and Sephadex LH-20 column chromatography, and crystalization. Its minimum inhibitory concentrations (MICs) were $12.8\mu\textrm{g}$/ml for F. oxysporum and Alternaria mali, $6.4\mu\textrm{g}$/ml for Colletotrichum gloeosporioides and Rhizoctonia solani, and $3.2\mu\textrm{g}$/ml for Phytophthora capsici. Soil drenching of antibiotic KB-8A in the concentrations of $13.0\mu\textrm{g}$/ml and $26.0\mu\textrm{g}$/ml effectively inhibited the Fusarium wilt of sesame in a greenhouse test, which appeared to be comparable to the fungicide benlate of $6.5\mu\textrm{g}$ a. i./ml.

• Microbiology and Biotechnology Letters
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• v.19 no.1
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• pp.82-87
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• 1991

Xanthomonns curnpestris M12, Xunthornonas sp. M28, Acinetuhucter Iwofz GI, and Klebsiella pneumoniae L25, Pseudomonas rnaltophiliu N246 were screened to increase the ability for crude oil utilization. All of these could utilize hexadecane and octane with the exception of N246 strain for only octane biodegradation. Thus N246, M12, and M28, strains were specially examined for octane oxidation. Octane biodegradation by three strains showed the optimal conditions at $30^{\circ}C$, pH 7.0~9.0, and 0.2~0.3% octane concentration as a substrate. It was found that P. multofihila N246 and X. curnpestns M12 had plasmid and the cured plasmid from N246 strain lost octane uitilization. Therefore, it was confirmed that certain genes for octane utilization were Iocated on OCT plasmid in N246 strain. The size of OCT plasmid in N246 strain was 118 kb. The N246 strain was resistant to ampicillin.

• Journal of the Korean Society of Tobacco Science
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• v.22 no.1
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• pp.7-12
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• 2000

This study was conducted to identify useful germ plasm sources of resistance to black shank, Phytophthora. parasitica, in Nicotiana tabacum and to characterize the interaction between host plant resistance to black shank and pathogen variability. The six internationally represen-tative set of black shank resistant and susceptible tobacco genotypes and four Korean lines were tested for black shank on the field infested with P. parasitica at Chonju Experiment Station, Korea Ginseng & Tobacco Research Institute during the 1992～1997 growing season. Almost 100% of the plants of the most susceptible genotype, Ky 14, did not survive. Complete survival of (MS Ky 14 x L8)F$_1$, which is resistant to reee 0 and ausceptible to reace 1, suggests that Race 0 is the only race of the P. parasitica in this bield. Coker 371 Gold and Beinhart 1000-1 having excellent resistance to black shank could be recommended as the parental cultivars for improving black shank resistance in Korea. Data of the diseased plants showed that KB 101 and KB 110 were medium high resistant and KB 103 and KB 108 being low resistant to black shank.