새로운 반합성 Rifamycin 유도체 KTC-1의 랫트 최기형 시험

김종춘,정문구,박종일,한상섭 한국독성학회 1995 Toxicological Research Vol.11 No.1

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.

랫드에 있어서 배양배자에 대한 Phenytoin의 최기형성 효과

김종춘,임광현,정문구,노정구,Kim, Jong-Choon,Lim, Kwang-Hyeon,Chung, Moon-Koo,Roh, Jung-Koo 한국독성학회 1998 Toxicological Research Vol.14 No.3

The teratogenic potential of the anticonvulsant drug phenytoin (PHT) has been well documented both in the human and in the experimental animals. However there are few reports on the effects of PHT on embryonic development in rats in vitro. The present study was performed to evaluate the teratogenic effects of PHT using whole-embryo culture system in rats. Sprague-Dawley rat embryos were explanted on gestational day (GD) 9.5 and cultured for 48 hrs in the immediately centrifuged and heat-inactivated rat serum containing 0,25,50, or $100{\mu}g$ PHT/mL. At the end of culture period the embryos were scored for morphological development according to the procedure of Van Maele-Fabry, and their total protein contents were determined. At 100 ${\mu}$g/mL of culture medium. PHT caused significant reduction in developmental score and protein content of embryos and a high incidence morphological abnormalities (100%). Characteristic malformations included altered yolk and embryonic circulation, craniofacial hypoplasia, neural tube schisis, branchial arch defects, abnormal ratation, and limb bud hypoplasia, among others. There were no adverse effects on embryonic growth and development at concentrations of 25 and 50 ${\mu}$g /mL of culture medium. The results indicated that the dysmorphogenic effect of PHT on cultured embryos is due to a direct interference with embryonic development.

Integration of ENIE (English Newspaper In Education) as a Source of Language Input and a Medium for Extensive Reading Program

김종춘 사단법인 한국융합기술연구학회 2024 아시아태평양융합연구교류논문지 Vol.10 No.2

Today, when English proficiency is vital globally, innovative teaching resources that effectively portray real-life English use are needed. This urge is strongest in non-English-speaking countries. This problem can be solved by using English Newspapers in Education (ENIE) as a language input and Extensive Reading (ER) medium, notably in Korean English as a Foreign Language context. This study aimed to investigate the integration of English Newspapers in Education (ENIE) as a source of language input and a medium for Extensive Reading (ER) within the South Korean EFL context. The research involved 50 intermediate level of university nursing students in an English for Specific Purposes (ESP) class over a 10-week period, utilizing a mixed-method approach that included a questionnaire and interviews. Results from the questionnaire and inverviews indicated a generally positive response to ENIE, with increased reading ability, autonomy, and engagement reported by the majority of students, despite some challenges such as language complexity and cultural relevance. They indicate a generally positive reception, with the majority (68%) reporting improvements in reading ability, 84% acknowledging English newspapers as a beneficial source of language input, and 88% expressing interest in continuing to engage with online English newspaper articles independently. The findings suggest that ENIE can significantly contribute to language learning when tailored to students' levels and interests, combined with adequate teacher training and resource curation. This study investigates the incorporation of English Newspapers in Education (ENIE) into the Korean EFL curriculum, aiming to bridge the gap between traditional language instruction and the demands of global communication and literacy, by examining its effectiveness in enhancing extensive reading skills and providing authentic language exposure for educators, curriculum developers, and language learners. The results should inform pedagogical tactics, make English language teaching more engaging and relevant, and give Korean students the linguistic and critical thinking abilities they need for global interactions.

Analyzing the Impact of Book Reports on Reader Proficiency and Fluency in Extensive Reading Program

김종춘 사단법인 한국융합기술연구학회 2024 아시아태평양융합연구교류논문지 Vol.10 No.3

This study aimed to investigate the effectiveness of book reports in learning portfolios in the context of English as a Foreign Language (EFL) education in Korea. Driven by a mixed-methods research design, the study combined quantitative assessments with qualitative feedback to explore the impact of book reports on learners' reading competency and fluency. The study involved 83 participants and the intervention spanned 15 weeks, with the students having access to an extensive selection of 461 graded books available both digitally and in print. The study assessed the impact of book reports on critical reading measures, including TOEIC RC (Test of English for International Communication Reading Comprehension), Accelerated Reader (AR), Reading Speed, and Reading Speed Comprehension. It aimed to identify differences in results between two different teaching approaches: Educator-facilitated and Learner-initiated. In addition to quantitative evaluations, the study integrated input from participants, collected through questionnaires and interviews, to offer a comprehensive perspective on the impact of book reports on enhancing reading ability and fluency. The key findings indicate that book reports significantly enhance reading ability with notable variances observed between the two teaching approaches. The educator-facilitated approach yielded more pronounced improvements, which suggest that the integration of book reports in extensive reading program can be a potent tool in EFL settings, with different methodologies catering to varied learning objectives. By integrating these diverse perspectives, the study result, in terms of implication, aspires to offer insights into the value and impact of book reports, thus contributing to the optimization of learning portfolios for the enhancement of reading skills among EFL learners.

새로운 반합성 Rifamucin 유도체 KTC-1의 랫트 수태능력 시험

김종춘,정문구,노정구 한국독성학회 1996 Toxicological Research Vol.12 No.1

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.

Sprague-Dawley 랫드를 이용한 수태능 및 초기배 발생실험의 기초자료연구

김종춘,이상준,서정은,차신우,김충용,한정희,정문구 한국독성학회 2002 Toxicological Research Vol.18 No.2

Historical control data have been shown to be valuable in the proper interpretation and validation of reproductive toxicology studies. The present data were compiled from rat fertility and early embryonic development studies conducted at Korea Institute of Toxicology during the 1994~2001 period. These data were assembled in order to provide background informaton for the general and reproductive data collected in 11 fertility and early embryonic development studies using Sprague-Dawley rats obtaining from the Breeding Facility, Korea Institute of Toxicology, Korea. A total of 274 males and 274 females were used in these studies during the eight-year period. Parameters of fertility and early embryonic development included clinical signs, body weights, food consumption, organ weights, estrus cycle, copulation index, precoital time, fertility index, pregnancy index, sperm parameters, and early embryonic development parameters. Most of the values were comparable to the previous historical control data reported by other investigators. These data can be used not only as a historical database for the meaningful interpretation of data from reproductive and developmental toxicity studies, but also as a contribution to biological characterization of Sprague-Dawley rats.

랫드에서 fluoroquinolone 항균제 DW-116 의 단회 경구투여에 의한 태반통과와 약물동태연구

김종춘,윤효인,신호철,허정두,이종화,정문구 한국응용약물학회 2002 Biomolecules & Therapeutics(구 응용약물학회지) Vol.10 No.4

랫드에서 표준 및 사료제한 시험에 의한 fluoroquinolone 항균제 DW-116의 발생독성평가

김종춘,윤효인,이희복,한상섭,정문구 한국생명과학회 2001 생명과학회지 Vol.11 No.5

임신랫드에서 fluoroquinolone 항균제 DW-116에 의해 유발된 발생독성이 모동물의 사료섭취량 감소에 의한 영양 결핍이 주요 원인인지 아니면 DW-116이 배.태자에 직접적으로 작용하여 유발된것인지를 조사하고자 시험물질을 랫드에 임신 6일에서 16일까지 0 및 500 mg/kg 용량으로 반복 경구투여하였다. 사료제한군은 시험물질 투여군의 모동물의 섭취한 동일한 양의 사료를 제한급여하였다. 모든모동물을 임신 20일째에 제왕절개하였고, 모독성 및 발생독성을 평가하였다. 시험물질 투여군에서는 독성증상과 체중의 감소, 투여 및 투여후 기간의 체중증가 억제, 사료섭취량의 감소를 포함하는 모독성이 부형제대조군및 사료제한군에 비해 현저하게 증가하였다. 또한, 태자사망의 증가, 생존태자의 감소, 태자체중과 태반중량의 감소, 태자기형의 증가 및 골환지연을 포함하는 발생독성도 현저하게 증가하였다. 반면, 사료제한군에서는 모체 및 태자에서 경미한 독성고견만 인정되었고, 태자사망이나 태자기형 등의 심각한 발생독성은 관찰되지 않았다. 결론적으로 시험물질투여군에서 관찰된 발생독성은 사료섭취량의 감소에 의한 모체의 영양결핍에 기인된 것이 아니라 DW-116의 투여에 기인된 직접효과인 것으로 판단된다. We have recently demonstrated that the fluoroquinolone antibacterial DW-116 caused a significant developmental toxicity in rats. The present study was conducted to determine whether the development toxicity induced by DW-116 treatment was the result of malnutrition fro reduced food intake or the direct effects of test chemical on conceptuses. The test chemical was administered by gavage to pregnant rats from gestational days 6 through 16 at dose levels of 0 and 500 mg/kg/day. A pair-feeding study was also performed in which the pregnant rats received the same amount of diet consumed by the DW-116-treated pregnant rats. All dams were subjected to caesarean section on day 20 of gestation and their fetuses were examined for examined for external, visceral, and skeletal abnormalities. In this treatment group, the maternal toxicities included increased abnormal clinical signs, decreased maternal body weight, suppressed body weight gain during treatment and posttreatment periods, and reduced food intake. The significant developmental toxicities included increased fetal deaths, decreased live fetuses, reduced fetal body weight and placental weight, increased incidence of fetal abnormalities, and increased fetal ossification delay. In this pair-fed group, however, slight maternal toxicities including decreased body weight and suppressed body weight gain during treatment period were observed in comparison with the control group, and minimal development toxicities including reduced fetal and placental weights and increased fetal ossification delay were found. The number of fetal deaths and live fetuses, and the incidences of malformed fetuses and litters with affected fetuses were comparable to the control values. Based on the results, it could be concluded that the development toxicity observed in the treatment group is attributable to the direct effects of Dw-116 treatment, but not to the maternal malnutrition from reduced food consumption during pregnancy.

경유 중 황 및 방향족화합물 조성에 따른 배출가스 특성연구 : 미량대기오염물질 중심으로

김종춘,서충열,임윤성,임철수,임재현,이종태,윤창완,이상일,김홍규,김상규,황춘식 한국대기환경학회 2008 한국대기환경학회 학술대회논문집 Vol.- No.-

오존과 자동차

김종춘 한국자동차공학회 2012 오토저널 Vol.34 No.7