• Archives of Pharmacal Research
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• 제10권3호
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• pp.193-196
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• 1987

Protein methylation occurs ubiquitously in nature and involves N-methylation of lysine, arginine, histidine, alanine, proline and glutamine, O-methylesterfication o dicarboxylic acids, and S-methylation of cysteine and methionine. In nature, methylated amino acids accur in highly specialized proteins such as histones, flagella proteins, myosin, actin, ribosomal proteins. hn RNA-bound protein, HMG-1 and HMG-2 protein, opsin, EF-Tu, EF-$1\alpha$, porcine heart citrate synthase, calmodulin, ferredoxin, $1\alpha$-amylase, heat shock protein, scleroderma antigen, nucleolar protein C23 and IF-3l.

• Applied Microscopy
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• 제10권1_2호
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• pp.27-32
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• 1980

중동지방에 다녀온 48세의 한국인 남자 피부에 발생한 leishmania증 1예에 대하여 광학 및 전자현미경적 관찰을 하여 문헌 고찰과 아울러 보고하였다. 광학현미경적으로는 조직구 침윤을 주로 하는 만성 육아종성염증반응을 보였고 Giemsa염색상 다수의 leishmania충체를 조직구내에서 관찰할 수 있었다. 전자현미경적으로는 난원형의 단세포 또는 분열중인 충체가 조직구내에 존재하였고 충체는 이중막으로 싸였으며 그 바로밑에 microtubule이 배열되고 세포질내에는 신장된 mitochondrion내에 kinetoplast가 존재하고 그 전방에 flagella가 위치하였으며 기타 다수의 ribosome과 드물게 Golgi complex등을 관찰할 수 있었다. 이와같은 특징은 Leishmania tropica의 promastigote stage와 일치하였다. Leishmania증은 원칙적으로 열대병이나 열대지방과의 접촉이 빈번함에 따라 앞으로 우리나라에서도 보다 많은 증예가 발생할 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제4권4호
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• pp.290-295
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• 1994

30 monoclonal antibodies (mAbs) were produced against Bacillus thuringiensis subsp. canadensis. Out of the these, 6 mAbs were selected for further studies. SDS-PAGE analyses of sonicated antigens of 10 8. thuringiensis strains showed that they generally had both predominant protein antigens of molecular weights of 45 kilodalton (kd) except for shandogiensis and konkukian, and 37kd except for israelensis, tochigiensis, and shandogiensis, respectively. These results indicate that 4kd and 37kd may be important for demonstrating common antigens except for a few strains of B. thuringiensis. In comparing the result of the westem blot using mAbs with that of using polyclonal antibodies to canadensis, we found that immunoreactive proteins of 99 and 39 kd were identified as common antigens, which might act as antigenic determinants, and might be surface or flagella antigens. Reactivities of mAbs with 41 strains of 8. thuringiensis demonstrated that mAbs of C-1, C-3, C-4, C-S and C-6 except C-2 did not recognize epitopes of thuringiensis, but that all of the mAbs recognized epitopes of galleriae, kurstaki, dakota, tolrJokuensis, silo, toguchini, and leesis. The potential applications of the mAbs we produced would be useful tools for the clarification of taxonomy, investigation of antigenic relationship between B. thuringiensis strains, and localization of specific surface and flagella antigens.

• Applied Microscopy
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• 제33권4호
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• pp.267-274
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• 2003

난태생 어류인 성숙한 Xiphophorus maculatus의 정소를 적출하여 정자형성과정과 정자의 미세구조를 전자현미경으로 관찰하였다. 정자형성과정은 정소낭(testicular cyst)에서 이루어지며, 각 정소낭 내에 동일한 분화시기의 생식세포가 분포하고 있었다. 정원세포는 타원형으로 핵 내에 뚜렷한 인을 보유하고 있었고 세포질에는 미토콘드리아의 발달이 현저하였다. 제1정모세포는 원형으로 정원세포보다 크기가 작았고 인은 발달되어 있지 않았으며, 제2정모세포는 제1정모세포보다 더 작아졌고 핵의 전자밀도는 더 높았다. 정세포의 초기발달시기에는 세포의 크기가 정모세포보다 작았고 염색질의 응축은 핵막 쪽에서 뚜렷하여 전자밀도가 높았으며 편모가 형성되기 시작하였고 미토콘드리아는 핵 주변에 분포하였다. 정자완성과정 중기에는 핵의 염색질 응축이 뚜렷하였으며 핵은 세포질 한쪽에 치우쳐 있었고, 미토콘드리아는 편모 주변에 집중되었으며 핵은 구형을 이루고 있었다. 완전히 성숙한 정자의 두부형태는 장원추형이었고 두부에서 첨체는 관찰되지 않았으며 편모의 미세소관 배열은 9+2구조를 이루고 있었다. 또한 정자의 꼬리 끝에는 고리형태의 구조물 보유하고 있었다.

• Molecules and Cells
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• 제28권4호
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• pp.389-395
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• 2009

We previously observed that the transcription of some flagellar genes decreased in Salmonella Typhimurium tdcA mutant, which is a gene encoding the transcriptional activator of the tdc operon. Since flagella-mediated bacterial motility accelerates the invasion of Salmonella, we have examined the effect of tdcA mutation on the invasive ability as well as the flagellar biosynthesis in S. Typhimurium. A tdcA mutation caused defects in motility and formation of flagellin protein, FliC in S. Typhimurium. Invasion assays in the presence of a centrifugal force confirmed that the defect of flagellum synthesis decreases the ability of Salmonella to invade into cultured epithelial cells. In addition, we also found that the expression of Salmonella pathogenicity island 1 (SPI1) genes required for Salmonella invasion was down-regulated in the tdcA mutant because of the decreased expression of fliZ, a positive regulator of SPI1 transcriptional activator, hilA. Finally, the virulence of a S. Typhimurium tdcA mutant was attenuated compared to a wild type when administered orally. This study implies the role of tdcA in the invasion process of S. Typhimurium.

• Journal of Microbiology and Biotechnology
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• 제18권11호
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• pp.1762-1767
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• 2008

Image contrast of whole bacteria was compared in Staphylococcus aureus and Escherichia coli depending on pre-stain suspension liquids by energy-filtering transmission electron microscopy. The two bacterial strains were suspended in three most commonly used liquids for negative staining (triple distilled water [DW], phosphate-buffered saline [PBS], and nutrient broth [NB]) and directly observed without staining or stained with neutralized potassium phosphotungstate (PTA), respectively. Even though in low contrast, unstained bacteria were observed owing to their inherent electron density and cell shape in zero-loss (elastic scattering) images. After being suspended in PBS, unstained bacteria appeared to have higher contrast and more refined periphery than DW-suspended ones, and extracellular appendage structures such as fimbriae and flagella could be discerned. The unstained bacteria appeared to be invariably surrounded with electron-lucent precipitates, possibly from PBS. As far as delineation of the structures, the combination of DW or PBS suspension with subsequent staining provided the most satisfactory results, as evidenced by the high contrast of bacterial morphology and appendage structures. However, after being suspended in NB and stained with PTA, bacteria often had too high contrast or poor staining, with electron-dense aggregates around the bacteria. These results suggest that suspension with concentrated organic aliquots including broth media before PTA staining could deteriorate image contrast, and should be used only in dilute form for visualizing bacterial morphology and appendage structures. Moreover the contrast enhancement of unstained bacteria by salt granules would be advantageous in demonstrating bacterial sorption of environmental particles like heavy metals, maintaining minimal contrast for cell imaging.

• ALGAE
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• 제19권3호
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• pp.277-282
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• 2004

Prymnesium patelliferum was collected from Hwajinpo, South Korea in November 2002. This is the first record of P. patelliferum in Korea waters. The characteristic shape of P. patelliferum was that of a rice grain. Cells were sub spherical or elongate, and sometimes slightly compressed. The motile cells of P. patelliferum (8-10 ㎛ long, 5-6 ㎛ broad) prossessed two equal or sub equal flagella(10.5-13 ㎛) and a short non-coiling haptonema (3-5 ㎛). The cell was covered by two layers of organic scales, which were important taxonomic characteristics. Internal scales were a narrow inflexed rim on the distal face, a thickening central and radial fibrillar pattern. External scales were very similar to internal scales with relatively tall upright rims. The ridges were in quadrants with 11-12 ridges per quadrant.

• 환경위생공학
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• 제8권1호
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• pp.129-138
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• 1993

The marked spread of the cockraches of recent years has raised a great social problem in urban areas. The cockroach have to remove1 because transmit a disease to human as pest insect, but particulars are not yet reported on biological control agent for the cockroach removal. This study was tried for the first time on biological control for the cockroach removal. The obtained results were as follows : 1. The isolated were spore-forming bacillus 1098 strain in soil. The No. 109(TH 109) strain of the among spore-forming bacillus was showed the poisonous against Cockroach. 2. The biological characteristics and flagella antigenicity of the strain is similar to Bacillus thur-ingiensis subsp. indiana. 3. TH 109 strain have the delta-endotoxin of cuboid shap. 4. This delta-endotoxin of product by TH 109 strain was toxic to the cockroach(Blattella gemzanica. L).

• 한국미생물·생명공학회지
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• 제27권4호
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• pp.286-291
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• 1999

By using autoradiography and phosphate medium, high phosphate accumulating bacteria were isolated from the soil of protected cultivation area and activated sludge. Selected strain, PO8, was gram-negative, rod/spherial(0.5~0.6$\times$1.0~1.2${\mu}{\textrm}{m}$ in size) and non-motile. PI4, another selected strain, was gram-negative, rod(0.4~0.5$\times$1.5~1.6${\mu}{\textrm}{m}$ in size) and motile. It also had flagella. According to their morphological, physiological and biochemical properties, the stains were identified as Acinetobacter lwoffi PO8 and Chromobacterium lividum PI4, respectively. A. lowoffi PO8 and C. lividum PI4 cultured in the P-1 medium containing 150ppm phosphate were able to uptake high phosphate up to 92% and 85%, respectively after 24 hours at 3$0^{\circ}C$ during liquid culture.

• Fisheries and Aquatic Sciences
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• 제3권3_4호
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• pp.205-212
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• 2000

Light and electron microscopical characteristics of Perkinsus sp. parasitizing in Manila clam, Ruditapes philippinarum, in Korea were investigated. Trophozoite within the tissue was spherical or ovoid and ranged $2.5-10.5\mu m$ $(mean = 6.2\mu m)$ in diameter. Trophozoite had a nucleus with a prominent nucleolus and a large cytoplasmic vacuole within the cytoplasm. Single trophozoite was phagocytozed by host hemocyte and cluster cells were encapusulated by hemocytes aggregation within the host tissues. Hypnospores incubated in thioglycollate medium (FTM) for 1 to 15 days were also spherical or ovoid and ranged $10-132\mu m$ $(mean\pm S.D.\;:\;44.25\pm 7.91\mu m)$ in diameter. Zoospores were spherical or ovoid, had a nucleus and two flagella. Zoospores contained apical complex, which consisted of conoid, subpellicular microtubules, rhoptries and rectilinear micronemes.