• Toxicological Research
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• 제11권1호
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• pp.81-89
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• 1995

A teratogenicity study of KTC-1, a new semisynthetic rifamycin antituberculous drug, was conducted in Sprague-Dawley rats. Dosages of KTC-1 0, 7, 21, and 63 mg/kg/day were administered to darns orally gayage from day 7 to day 17 of gestation. Two-third of dams per group were subjected to cesarean section on day 21 of pregnancy for examination of their fetuses, and the remaining one-third of darns per group were allowed to deliver naturally for postnatal examination of their offspring. At 21 mg/kg/day, an increase in the skeletal variations of F1 fetuses and a decrease in the body weight of F1 offspring were seen. At 63 mg/kg/day, a loss in body weight was observed in darns. An increase in fetal death rate, a decrease in litter size and body weight, and an increase in the incidence of visceral malforrnations and skeletal variations were found in F1 fetuses. In particular, lumar rib occurred at an incidence of 31%. In addition, an increase in the dead newborns at birth and neonatal deaths during the lactation period, a loss in body weight, and a decrease in spleen weight were observed in F1 offspring. There were no signs of maternal toxicity or embryotoxicity at 7 mg/kg/day. The results suggest that the no-effect dose level(NOEL)for dams is 21 mg/kg/day, and NOELs for F1 fetuses and offspring are 7 mg/kg/day.

• 한국산업보건학회지
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• 제16권2호
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• pp.91-100
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• 2006

The purpose of this study was to validate alternative method by using non-carcinogenic, and less toxic solvents than NIOSH analytical method 5524 for measuring the airborne MWFs in workplaces. In laboratory tests, the ETM solvents(mixture of same volume for ethyl ether, toluene, and ethanol) were selected. The alternative method of analyzing MWFs, referred to as the ETM solvent extraction method, showed 0.04 mg/sample as LOD, and 0.15 mg/sample as LOQ. The analytical precision (pooled CV, coefficient of variation) of the ETM solvent extraction method for analyzing the straight, soluble, semisynthetic, and synthetic metalworking fluid was 1.5%, 2.0%, 2.6%, 1.6%, respectively, which was similar to the precision (2.6%) of NIOSH analytical method (NIOSH 0500) for total dust. The analytical accuracy by recovery test, spiked mass calculated as extractable mass, was almost 100%. As the result of storage stability test, metalworking fluid samples should be stored in refrigerated condition, and be analyzed in two weeks after sampling. The 95% confidence limit of the estimated total standard error for the ETM solvent extraction method for analyzing the straight, soluble, semisynthetic, and synthetic metalworking fluid was ${\pm}12.6%$, ${\pm}12.5%$, ${\pm}14.0%$, and ${\pm}13.6%$, respectively, which satisfied the OSHA sampling and analytical criteria.

• Toxicological Research
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• 제12권1호
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• pp.93-99
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• 1996

The effect of KTC-1, a new semisynthetic rifamycin antituberculous drug, on general toxicity, reproductive capability and fetal development was investigated in Sprague-Dawley rats. Male rats were administered KTC-1 with mashed feed from 63 days before mating to the end of mating period, and female rats were given from 14 days before mating to day 7 of gestation at dose levels of 0, 375, 750, and 1,500 ppm. The females were sacrificed on day 21 of gestation for examination of their fetuses. At 1,500 ppm, a reduction in body weight gain and testis atrophy were observed in male rats. Histological examination revealed testicular atrophy, absence or decrease of germinal cells, and vacuolization of Sertoli cells in testis. A reduction in body weight gain, a decrease in food consumption were found in female rats. In addition, decreases in the number of corpora lutea, iraplantations, and the litter size of live fetuses were seen. Mating, fertility, and pregnancy performances were also affected. There were no external abnormalities observed by examination of fetuses. At 750 ppm, a reduction in the body weight gain of male and female rats and decreases in the number of implantations and litter size were found. At 375 ppm, no treatment-related effects were observed. The results suggest that the no-effect dose levels (NOELs) of KTC-1 are 375 ppm for males and females on general toxicity, 750 ppm for males and females on reproductive capability, and 375 ppm for fetuses on embryonic development.

• KSBB Journal
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• 제11권3호
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• pp.263-269
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• 1996

유럽 주목(Taxus baccata Pendula) 의 세포배양에 서 추출한 taxol 전구체 baccatin ill를 이용하여 항암제 taxol을 반합성할 수 있었다. 유럽주목의 캘러 스배양과 현탁배양 모두에셔 baccatin ill의 생성을 확인할 수 있었으며 함량은 건조중량 기준으로 평균 0.015%(w/w)에 달하였다. Taxol의 반합성은 세포 배양에서 생성된 baccatin ill에 taxol side chain을 합성시킴으로서 가능하였다. Taxol side chain을 합 성하기 위하여 (S)-(+)-phenylglycine로부터 (-) - -N-(S)-2-hydroxy-l-phenyl ethyl)benzamide를 합성하였고 다음 단계로 (-)-N-(lS,2S)-2-hy­d droxy-l-phenyl-3-butenyl) benzamide를 합성하 였고 최종적으로 산화과정을 거쳐 taxol side chain 인 (2R,3S) - (-) -2-(1-ethoxyethoxy)-3-phenyl-3 (phenylmethanamido) propanoic acid를 얻을 수 있었다. 이러한 반합성 과정을 통하여 0.0002 % 수준의 taxol 및 0.0005 %의 관련 taxane을 합성하였다. 이와 같이 주목 세포배양을 이용한 taxol 반합성 방법은 기존의 주목 잎에서 추출한 baccatin ill를 이용하는 방법에 비하여 충분한 경제성이 있을 수 있으며 이에 따라 taxo!의 새로운 공급원의 역할 및 기타 여러 종류의 taxol 유사체의 효율적인 이용 등 앞으로 기대 효과가 크다고 본다.

• 한국식품영양과학회지
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• 제21권3호
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• pp.247-254
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• 1992

1주령 병아리에 무콜린 식이를 급여하거나 무콜린 식이에 butanolamine을 첨가 급여하여 콜린 결핍을 심화시켜, 콜린 결핍이 지질대사에 미치는 영향을 알아보았다. 그 결과 콜린 결핍은 간장중량, 혈장 지질 및 지단백 수준에 유의적인 영향을 나타내지 않았다. 또한 간세포의 소포체에서 $^{14}$ C-oleic acid의 지질 혼입율에도 유의적인 영향을 끼치지 않았다. 한편 estrogen을 투여하여 고지혈증을 야기 시킨 경우 콜린 결핍군의 VLDL상승 정도가 낮은 경향을 나타내었고 비간장 무게와 간장의 지질함량은 증가하는 경향을 나타내었다. 한편 콜린 결핍은 병아리의 성장을 저해하였다 성장에 필요한 콜린을 충분히 합성하지 못하는 어린 병아리에 콜린 결핍을 야기 시켜 얻어진 이러한 결과는 간세포에서의 VLDL방출에 콜린이 크게 작용하지 않음을 시사하여 주었다. 그러나 고지혈증이 유발된 상황에서 극심한 콜린 결핍은 VIDL방출에 약간의 영향을 끼칠 수도 있음을 나타내었다.

• Genomics & Informatics
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• 제6권4호
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• pp.227-230
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• 2008

Compounds of polyketide origin possess a wealth of pharmacological effects, including antibacterial, antifungal, antiparasitic, anticancer and immunosuppressive activities. Many of these compounds and their semisynthetic derivatives are used today in the clinic. Most of the gene clusters encoding commercially important drugs have also been cloned and sequenced and their biosynthetic mechanisms studied in great detail. The area of biosynthetic engineering of the enzymes involved in polyketide biosynthesis has recently advanced and been transferred into the industrial arena. In this work, we introduce a computational system to provide the user with a wealth of information that can be utilized for biosynthetic engineering of enzymes involved in post-PKS tailoring steps. Post-PKS tailoring steps are necessary to add functional groups essential for the biological activity and are therefore important in polyketide biosynthesis.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권2호
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• pp.180-184
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• 2001

MRSI is the staphylococcal infection having resistance to the methicillin which is semisynthetic penicillinase-resistant agents against penicillinase. These infections are very difficult to treat because they have resistance to almost every antibiotics except for vancomycin. We experienced MRSE(methicilline-resistant staphylococcal epidermis) infected 56 years old man who developed 2 months after arthroplasty for TMJ ankylosis and MRSA(methicilline-resistant staphylococcal aureus) infected 59 years old man who was performed arthroplasty far traumatic TMJ disc displacement.

• Toxicological Research
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• 제23권1호
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• pp.19-24
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• 2007

We demonstrate that paclitaxel, an antitumor agent derived from yew tree, inhibits LPS- and $IFN-{\gamma}$-induced NF-kB/Rel activation in RAW 264.7 cells. Previously, paclitaxel ($>10{\mu}M$) has been known to induce iNOS gene expression in macrophages. However, in the previous report we described that the pretreatment of macrophages with low concentration of paclitaxel ($0.1{\mu}M$) for 8 h inhibited LPS-induced iNOS gene expression. Pretreatment of RAW 264.7 cells with paclitaxel significantly inhibited NF-kB/Rel transcriptional activation. Electrophoretic mobility shift assay further confirmed that pretreatment of macrophages with paclitaxel inhibited NF-kB/Rel DNA binding. Taxotere, a semisynthetic analog of paclitaxel, also inhibited LPS- and $IFN-{\gamma}$-induced iNOS gene expression. Collectively, these series of experiments indicate that paclitaxel inhibits iNOS gene expression by blocking NF-kB/Rel activation.

• Asian-Australasian Journal of Animal Sciences
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• 제14권6호
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• pp.811-815
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• 2001

The study evaluated different synthetic and semisynthetic media for maximal recovery of rumen bacteria and expression of their antibacterial activity. Rumen Glucose Cellobiose Agar (RGCA) medium was found to be the best for recovery of rumen bacteria. However, L-10 medium was the best for expression of antibacterial activity of ruminal isolates followed by Easy, M-10, RGCA and M-98-5 medium. The present study recommends the use of L-10 medium as the medium of choice for screening of antibacterial activity of ruminal isolates. Comparative evaluation of bacterial counts on different dietary regimes indicated significant difference between different growth media on a specific diet and between diets on specific growth media within a species. However, there is no overall significant difference between total bacterial counts obtained from rumen liquor of cattle and buffalo with respect to either the feeding regime or growth media. Feeding straw based diet to the animal is the best for high recovery of rumen bacteria.

• 한국미생물·생명공학회지
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• 제23권5호
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• pp.556-558
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• 1995

A strain which showed cephalosporin C resistance and 7-aminocephalosporanic acid sensitivity was isolated from nature. Among the isolates, SS5 was sensitive to cephalosporin C, penicillin G, ampicillin, 7-aminocephalosporanic acid, 6-aminopenicillanic acid, and 7-aminodeacetoxy cephatosporanic acid at concentrations of 1,000 $\mu $g/ml, 2,000 $\mu $g/ml, 3,000 $\mu $g/ml, 30 $\mu $g/ml 100 $\mu $g/ml and 100 $\mu $g/ml, respectively. But SS5 was sensitive at very low concentration of chloramphenicol, kanamycin, neomycin, streptomycin and tetracycline. Since SS5 was sensitive to 7-ACA (30 $\mu $g/ml) and didn't have $\beta $-lactamase activity on the cephalosporin C, SS5 could be useful as an indicator strain for the production of 7-ACA, which is an important precursor for the synthesis of many semisynthetic cephalosporins.