• 한국수정란이식학회지
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• 제15권1호
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• pp.23-31
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• 2000

This study was conducted to investigate the effects of quiescent treatment of donor cells and activation treatment time of recipient cytoplasm on nuclear remodeling and in vitro development of somatic cell-cloned bovine embryos. Serum starved, confluent and nonquiescent cycling adult skin cells were teansferred into enucleated oocytes. Nuclear transfer oocytes were activated at 30 min, 1 and 2 hrs after electrofusion. Some nuclear transfer embryos(23% to 35%) extruded a polar body, which was not affected by quiescent treatment of donor cells and activiation time of recipient cytoplasm. About 68% of nuclear transfer embryos fused with a serum starved cells has a chromatin clump, but which was not different from embryos fused with confluent(51%) and nonquiescent(47%) cells. The proportion of embryos with a single chromatin clump was sightly increased when nuclear transfer embryos were activated within 30 min after fusion(69%) compared to those were activated at 1 and 2 hrs after fusion, but there was not significantly different. Development rates to the blastocyst stage were 8.6% and 15.9% when serum starved and confluent cells were transferred, which were higher than that of control group. Developmental rate to the blastocyst stage was higher in embryos were activated within 30 min after fusion (17.3%) compared to those of embryos were activated at 1 and 2 hrs after fusion (P<0.05). From the present result, it is suggested that quiescent treatment of donor cells and activation time of recipient cytoplasm can affect the in vitro development. Quiescent plasm activation within 30 min after fusion could increase the number of embryos with a normal chromation structure, which results in increased in vitro development.

• KSBB Journal
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• 제9권5호
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• pp.532-540
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• 1994

재조합 플라스미드 함유 효모 h$\alpha$1Y2SUCSTA 의 glucoamylase의 분비효율은 배양 4연째에 약 74%이였으며 염색체 삽입 재조합효모 h$\alpha$1Y2S­U UCSTA-I의 경우에는 4일째에 약 65%로 나타났다. 높은 분비효율을 나타낸 것은 glucoamy­I lase의 발현수준이 숙주세포 분비기관의 능력에 미치지 못하기 때문으로 추정된다. 두 재조합 균주에셔 모두 대부분의 세포내 glucoamylase는 c cytoplasm에 존재하고 약간의 부분만이 (10% 이내) 전 배양기간을 통하여 peri plasm에 존재하였다. 재조합 효모로부터 분비되는 glucoamy­1 lase의 특 생 을 Western blot 분 석 을 통하여 조사하였다. 배양액으로 분비된 glucoamylase는 매우 h heterogeneous하였고 그 분자량은 약 200에서 3 300 kilodalton이였다. 분비된 glucoamylase의 당 잔기량은 약 80% 이상이였고 세포내 glucoamy­l lase의 endoplasmic reticulum 형태는 약 55 에서 65kilodalton 사이의 여러 가지의 밴드로 나타났 다.

• Archives of Pharmacal Research
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• 제28권3호
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• pp.351-357
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• 2005

Endosulfan is one of the organochlorine pesticides, which are well-known endocrine disruptors (EDs), and it acts as an estrogen agonist. Estrogen is a group of hormones that play an important role in mammary gland function and are implicated in mammary carcinogenesis. In the present study, we studied the effects of endosulfan on nodule like alveolar lesion (NLAL) formation in mouse mammary gland development using a mouse mammary gland organ culture (MMOC) system. Although endosulfan-treated mammary glands did not form NLALs, more alveolar buds were formed in this group than in the negative control (vehicle-treated) group. In addition, telomerase reverse transcriptase (TERT) mRNA expression levels were increased in endosulfan-treated mammary glands in a dose-dependent manner. Telomerase can be activated by estrogen, therefore, we examined the effects of endosulfan on telomerase activity, and found that the telomerase activity in estrogen receptor-positive MCF-7 cells was up-regulated by endosulfan treatment. Moreover, this activation was accompanied by the up­regulation of the TERT mRNA expression. Also, transient expression assays using CAT reporter plasm ids containing various fragments of the TERT promoter showed that this imperfect palindromic estrogen-responsive element is almost certainly responsible for the transcriptional activation by endosulfan. These results may help elucidate the endocrine disrupting mechanism of endosulfan.

• 대한미생물학회지
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• 제22권1호
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• pp.35-53
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• 1987

Multiply resistant Shigella strains isolated in Taegu area were subjected for the characterization of R plasmids. All strains isolated in 1984 and 1985 were susceptible to gentamicin, amikacin, and cephalothin, and most strains were susceptible to kanamycin (Km) and rifampin by agar dilution antimicrobial susceptibility test. The resistance frequency of S. flexneri against ampicillin (Ap) was higher than that of S. sonnei. The strains resistant to sulfisomidine (Su) and trimethoprim (Tp) were found at higher frequency in S. sonnei than in S. flexneri. The most prevalent resistance pattern of S. flexneri was chloramphenicol (Cm) tetracycline (Tc) streptomycin (Sm) Ap, followed by the pattern of CmTcSmSuApTp, CmTcSmSuApTp nalidixic acid, and CmTcSmSuAp in the decreasing order. The antibiogram of CmTcSmSuTp was found to be the most frequent pattern in S. sonnei. The ratio of conjugal transfer of S. flexneri was 47% and 75% of S. sonnei. The average number of plasmid harboring in Shigella was 4 and the size of plasmid ranged 1.3 to 134 megadalton (Mdal). Most S. flexneri carried plasmids of 2 to 3 Mdal and S. sonnei carried those of 3 to 4 Mdal size. The sizes of conjugative plasmids ranged 40-90 Mdal. The incompatibility group (Inc) F II plasmids (54-59 Mdal) were most frequent and rare Inc B plasmids (60 Mdal) of isolates in 1979 and 1980 and Inc FI (87 Mdal) of 1983 isolates were able to be classified by the colony test with standard reference plasmids. The R plasmids of known Inc group were tested for the restriction endonuclease analysis. The pattern of plasmids digested by EcoRl were apparently different by the Inc group but there was no significant difference between species or by the resistance patterns. Nonconjugative plasmids and their phenotypes were identified by transformation test. The transformants were resistant to less than two drugs. Colicin producing transformants carried the Col plasmid of 3.7 or 3.9 Mdal size. $Ap^r$ plasmids derived from S. sonnei were found to be mobilized by transfer factor RT641 to E. coli #CS100. $Ap^r$ plasm ids of same size shared by S. flexneri, S. sonnei, and E. coli were digested with Pstl. All of them showed two restriction fragments of 2.8 kilobase(kb) and 0.7kb. Other plasmids ($Sm^r\;Su^r$) derived from S. flexneri, S. boydii, and S. sonnei were digested with Pstl and they showed same restriction fragment patterns of 3.1kb and 2.9kb. The plasmid profiles of three strains of S. sonnei producing colicin and showing same resistance pattern of CmTcSmSuApTpKm appeared to be similar. Restriction patterns by EcoRl and the behavior of plasmids in conjugation or transformation process were also similar between those plasmids. The restriction patterns were significantly different between the plasmids of Inc FI group and those of unclassified Inc group.

• 한국작물학회지
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• 제35권1호
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• pp.44-52
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• 1990

돼지감자의 괴경반식 대신 종자반식에 의해서 건전한 유묘와 식물체를 육성함으로써 돼지감자 유전소재의 수집과 보존 및 개량에 종자반식을 이용하고자 하였다. 이를 위하여 국내외에서 수집한 9종(Mammoth French White, D-19, JA6, K-8, JA 13, Violet de Renne, Medius, Nahodka, Fuseau 60) 돼지감자 화기에서 종자를 채취하여 종피제거 방법에 의해 종자휴면을 타파한 후 종자로부터 발아유도되어 발생한 유묘의 생육특성을 조사하였으며 최종적으로 종자반식에 의한 바이오매스 생산성을 괴경반식에 의한 경우와 비교하여 다음의 결과를 얻었다. 1. 돼지감자 휴면종자는 종피제거방법에 의해 완전한 발아유도가 가능하였다. 2. 종자에서 발생한 유묘는 왜성형태를 유지하며 동시에 하배축을 비대시켜 하배축을 증대시켜 생리적 왜성(physiolo-gical dwarfing)의 특성으로 발현되는 경우가 겨울동안 온실에서 육묘한 경우에 한하여 나타났다. 3. 종자에서 발생한 유묘의 생리적 왜성은 JA6 품종의 경우 유묘령과 무관하게 12시간 미만의 단일에 감응하여 나타난 결과이었다. 4. 일단 발현된 유묘의 생리적 왜성은 생육기간동안 일장이 증가함에 따라 정상 식물체로 회복되었다. 5. 종자반식에 의한 육묘이식 재배시 괴경수량은 3.51 ton/10a으로 괴경반식에 의한 경우 3.02ton/10a에 비교하여 오히려 많았다. 6. 종자를 직접파종하였을 때 괴경수량은 괴경반식에 의한 경우의 52%에 불과하였다.

• 한국자원식물학회지
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• 제24권5호
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• pp.604-612
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• 2011

씀바귀추출물이 LPS shock 염증반응에서 항염증효과에 미치는 영향을 검토하기 위하여 생체 및 세포배양실험에서 전염증성 cytokine들의 생성과 혈액 내 생물학적 수치를 조사했다. 그 결과 LPS 염증유도 rat에서 씀바귀 추출물은 혈액 내 전염증성 cytokines 들, 즉 IL-$1{\beta}$, IL-6 및 TNF-${\alpha}$의 생산을 저해하고, 한편으로는 IL-10의 생산을 촉진하였다. 간장 IL-$1{\beta}$ 및 IL-6의 농도는 씀바귀추출물 처리군이 대조군보다 유의하게 낮은 값을 나타내었으나, TNF-${\alpha}$ 및 IL-10의 농도는 모든 처리군 간에 유의한 차이를 나타내지 않았다. Raw 264.7 cell의 세포배양실험에서는 TNF-${\alpha}$의 농도가 유의한 차이를 나타내지는 않았지만, 3개 cytokine 모두가 씀바귀 투여량이 증가함에 따라 감소하는 경향을 보였다. IL-10의 농도는 씀바귀 처리군 들 모두가 높은 경향을 나타내었다. 혈액 내 total protein 및 albumin의 농도는 대조군과 유의한 차이를 나타내지는 않았으나, 씀바귀추출물 처리 군에서 높은 경향을 보였다. 이상의 결과들을 종합해 보면 씀바귀 추출물에는 항염증반응에 관여하는 기능성물질이 내재하고 있음을 시사해 준다.

• 한국환경보건학회지
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• 제28권2호
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• pp.117-129
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• 2002

Concentration of welding fumes and their components is known to be hazardous to welder and adjacent worker. To determine the generation rates of metals in fumes, $CO_2$ flux cored arc welding on stainless steel was performed in well designed fume collection chamber. Variables were different products of flux cored wire(2 domestic products and 4 foreign products) and input energy(low-, optimal- , high input energy). Mass of welding fumes was determined by gravimetric method(NIOSH 0500 method), and 17 metals were analysed by inductively coupled plasm-atomic emission spectroscopy(NIOSH 7300 method). Flux cored wire tube and flux were analysed by scanning electron microscopy to determine their metal composition. 17 metals were classified by their generation rates. Generation rates of iron, manganese, potassium and sodium were all above 50mg/min at optimal input energy level. Generation rates of chromium and amorphous silica were 25~50mg/min. At 1~25mg/min level, nickel, titanium, molybdenum, and aluminum were included. Copper, zinc, calcium, lead, magnesium, lithium, and cobalt were generated below 1 mg/min. Generation rates of metal components in fumes were influenced by input energy, types of flux cored wire. Flux cored wire was consisted of outer shell tube and inner flux. Iron, chromium, and nickel were the major components of outer tube. Flux contained iron, chromium, nickel, potassium, sodium, silica, and manganese. The use of flux cored wire can increase the hazards by increasing the amounts of fumes formed relative to that of solid wire. The reason might be the direct transfer of elements from the flux, since the flux is fine power. Ratio of metals to the fume of flux cored wire was lower than that of solid wire because non-metal components of flux were transferred. Total metal content of fumes in flux cored arc welding was 47.4(24.3~57.2) percent that is much lower than that of solid wire, 75.9 percent. We found that generation rates of iron, manganese, chromium and nickel, all well known to cause work related disease to welder, increased more rapidly with increasing input energy than those of fumes. To reduce worker exposure to fumes and hazardous component at source, further research is needed to develop new welding filler materials that decrease both the amount of fumes and hazardous components.

• 대한미생물학회지
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• 제21권1호
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• pp.1-16
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• 1986

Fifty-one strains of Pseudomonas aeruginosa were isolated from various clinical specimens. Among them, 26 (51%) strains were gentamicin-resistant (Gm') and 25 (49%) were susceptible to gentamicin (Gm'). The frequencies of resistant strains to piperacillin (Pi), cefotaxime, moxalactam, cefoperazone (Cz), and amikacin (Ak) ranged from 21.6 to 31.4%, and $MIC_{50}$ of these drugs were lower than the critical concentrations of susceptibility and resistance. Thirty (58.8%) strains were multiply resistant to 12 or more drugs. All Gm' strains were multiply resistant to 12 or more drugs and one was resistant to all 18 drugs tested, while only four Gm' strains were multiply resistant to 12 drugs and the multiplicity of resistance of the other Gm' strains were less than 10 drugs. Resistance to Gm appeared to have a significant correlation with the resistance to tobramycin (Tb), Ak, Pi, and Cz. All Gm' strains were resistant to Tb and about 38.4 to 46.1% of them were resistant to Ak, Pi, and Cz. The incorporation of $Ca^{++}$ and $Mg^{++}$ ions in Mueller-Hinton agar (MHA) did not influence the MICs of Gm, Tb, carbenicillin (Cb), Pi, and Cz as compared with the results obtained in MHA without these ions. Gm strains were studied on the combined effect of beta-lactam antibiotics and aminoglycosides by the methods of checkerboard and modified paper strip diffusion. Most Gm' strains showed significant synergistic effects by the FIC index between Ak and three beta-lactam antibiotics; Cb, Pi, and Cz, but these results did not in agreement the results obtained through the method of modified paper strip diffusion test. In order to know the nature of the drug resistance of P. aernginosa, the plasmid profile analysis was studied. Agarose gel electrophoresis of lysates processed by the method of Kado and Liu showed one or more plasmids in 22 (43.1%) strains. A group of 19 strains showed at least one band of plasmid and three strains two bands. The range of the molecular weight of plasmids was 3.8 to 243 Mdal. All strains carrying large plasmids larger than 200 Mdal were isolated from wound specimens. Three Gm' strains also harboured the plasm ids of 13 to 203 Mdal.

• 미생물학회지
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• 제31권4호
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• pp.286-291
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• 1993

수계환경에서 세균의 접합에 의해 나타난 conjugant 에서 plasmid 의 재배열과 $Km^{r}$ 유전자의 행방을 조사하기 위하여 자연계 분리균주와 유전공학적 변형균주(GMM)의 $Km^{r}$ 유전자의 전이빈도를 조사하는 동시에 3.9 kb 의 $Km^{r}$ 유전자를 DNA probe 로 사용하여 Southern analysis 를 실시하였다. $Km^{r}$ 유전자의 전이빈도는 실험실 환경에서 GMM 균주가 자연계균주(DK1) 보다 100배 더 높게 나타났으나, 무심천에서는 균주에 따라 차이가 없었다. 실험실환경에서 DK1 균주를 donor 로 하여 LB 나 FW 에서 얻은 conjugant 들은 모두 같은 수의 plasmid 를 가지고 있었으나 크기는 다르게 재배열하였다으며, $Km^{r}$ 유전자는 donor 의 R plasmid 인 pDK101 과 비슷한 위치에서 발견되었다. GMM 균주가 donor 일 때에는 180 kb 의 plasmid 가 새로 나타났으며, 특히 FW 수질에서 donor 가 DKC600 일 때는 $Km^{r}$ 유전자가 염색체에 삽입되어 있었다. 무심천의 자연계 수질환경에서는 DK1 이나 DKB701 이 donor 일 때 4개 및 8개의 plasmid 가 새로 나타났으며, $Km^{r}$ 유전자는 재배열된 4개의 plasmid 와 염색체에서 발견되었다. DKC600 이 donor 일 때는 recipient 의 작은 plasmid 가 모두 소실되었으나, $Km^{r}$ 유전자는 새로 나타난 plasmid 와 염색체에서 발견되었다. 그러므로 자연환경에서의 수질에서는 plasmid 의 재배열이 더 다양했으며, $Km^{r}$ 유전자도 다양한 크기로 재배열된 plasmid 에서 발견되었다.

• 생명과학회지
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• 제17권6호통권86호
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• pp.756-761
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• 2007

능금속(Malus) 식물은 다년생 목본으로 국내에는 약 8종이 있다. 이 속에 있는 사과(M. pumila)는 경제적 중요작물로 그 기원은 서중국의 야생종 M. sieversii일 것으로 추정되고 있다. 우리나라에 자생하는 Malus내 모든 분류군과 중국의 M. sieversii를 RAPD로 분석하였다. 재배종이 높은 다양성을 나타낸 반면 제주아그배나무가 가장 낮은 다양성을 나타내었다. 재배종이 야생종보다 유전적 다양도가 더 높게 나타나 재배화 과정에서 여러 종과교잡이 일어나 많은 유전자가 침투된 것이라는 보고를 됫받침한다. 이 속은 M. sieversii를 포함한 사과나무, 능금나무가 같은 분자군을 형성하였고, 개아그배나무 또는 제주아그배나무(Malus micromalus), 아그배나무(Malus sieboldii), 꽃아그배나무(Malus floribunda)가 같은 분지군, 야광나무(Malus baccata), 개야광나무(Malus baccata for minor), 털야광나무(Malus baccata var. mandshurica)가 같은 분자군을 형성하였다. 한국내 재배종 사과와 능금이 국내 자생종 능금속에서 진화나 분지한 것은 아닌 것으로 판명되었고 오히려 중국 야생종이 그 기원의 하나일 가능성이 시사된다.