개 정액의 보존시 glycerol 첨가 및 정장제거가 정자의 성상에 미치는 영향

김계성,Kim, Kye-seong 대한수의학회 1993 大韓獸醫學會誌 Vol.33 No.2

Multiple ejaculates were collected from four male mongrel dogs. The second fraction and the small volume of third fraction from the ejaculates were divided and treated as follows : control; addition of the egg-yolk Tris extender to the semen at $37^{\circ}C$. group I; Removal of seminal plasma, group II; addition of the glycerolated extender at $4^{\circ}C$, group III Removal of seminal plasma and addition of glycerolated extender at $4^{\circ}C$. The semen cooled to $4^{\circ}C$ was equlibrated for 2hrs and preserved in refrigerator at $4^{\circ}C$. The preserved semen was evaluated for kinetics, morphology, motility and thermoresistance daily for 3 days. 1. The kinectics after preserved days 2 and 3 of group I was significantly higher than that of control(p<0.05). 2. There were no significant difference in abnormal morphology of each group between the periods of storage. 3. The motility after preserved day 1 and days 3 of group I was significantly higher than that of others(p<0.05), and the molity after preserved days 2 of group I and III was signficantly higher than that of others(p<0.05). 4. When the molity of preserved semen was measured during incubation at $37^{\circ}C$, the motility of four groups was declined at similar rates. There was no effect of removal of seminal plasma and glycerol addition on thermoresistance.

소 항정자항체가 소 정자의 수태능력에 미치는 영향

김계성,노상호,이강남,이병천,황우석,Kim, Kye-seong,Roh, Sang-ho,Lee, Kang-nam,Lee, Byeong-chun,Hwang, Woo-suk 대한수의학회 1997 大韓獸醫學會誌 Vol.37 No.4

This study was directed at inducing the production of antibodies by immunizing heifers with bovine sperm antigen and on measuring the serum antibodies using indirect immunofluorescence assay(IFA) and agglutination test. The effect of antisperm antibodies on fertilizing capacity of bovine spermatozoa was evaluated. 1. Three heifers between 12- and 15- month old were immunized with bovine spermatozoa or phosphate-buffered saline. In heifers immunized with bovine spermatozoa serum IgG level was highest between 3 weeks and 5 weeks postimmunization detected by IFA. The antibody levels persisted through week 7 and slowly declined until week 20 and then antisperm antibodies were localized on spermatozoa. The fluorescent antisperm antibodies were detected at 2~20 weeks and at 6~9 weeks postinoculation on acrosome and tail, respectively. Among 21 sera from repeat breeder cows, only one cow has shown positive antisperm antibody response detected by IFA. 2. In spite of vital rate of bovine sperm after swim-up was not significantly affected by different concentration of antisperm antibodies in sera, the numbers of bovine sperm after swim-up were significantly reduced in proportion to the increased concentration of antibodies. Above 1/512 dilution of antibody neither influence on vital rate and numbers of bovine sperm nor sperm agglutination after swim-up. The study has also shown that the vital rate and number of sperm after swim-up and capacitation were also significantly reduced by the addition of antisperm antibodies. Although antisperm antibodies did not influence on the acrosome reaction rate of sperm during swim-up, did significantly reduce the sperm acrosome reaction rate after capacitation. The studies have resulted that the bovine antisperm antibodies can prevent the sperm motility by agglutination and block the capacitation and acrosome reaction of bovine sperm.

구조 정보를 활용한 영형 주어의 조응성 결정

김계성(Kye-Sung Kim),박성배(Seong-Bae Park),박세영(Se-Young Park),이상조(Sang-Jo Lee) 한국정보과학회 2009 한국정보과학회 학술발표논문집 Vol.36 No.2A

절 간의 결속성에 기반한 비조응적 영 대명사의 식별 및 적용

김계성(Kye-Sung Kim),박성배(Seong-Bae Park),이상조(Sang-Jo Lee) 한국정보과학회 2014 정보과학회논문지 : 소프트웨어 및 응용 Vol.41 No.3

한국어에서는 문장요소, 특히 주어의 생략이 빈번하게 나타난다. 이러한 문장요소들의 생략은 한국어 복합문에서 빈번하게 나타나며, 절 간의 결속성을 높이는 언어적 장치로 간주할 수 있다. 본 연구는 문장 내 영 대명사 해결을 위해 절과 절 사이의 결속성을 바탕으로 영 대명사의 문장 내 조응성 결정하는 방법을 제안한다. 영 대명사의 조응성은 영 대명사와 지시대상 간의 조응적 연결을 통해 나타나는 상호작용으로 이해할 수 있으므로, 본 연구에서는 영 대명사와 지시대상을 가지고 있는 절들 간의 구조적 관계성을 통해 영 대명사의 문장 내 조응성을 결정하며, 이를 토대로 문장 내 비조응적 영형들은 문장 내 선행사 식별에서 배제될 수 있다. 문장 내 비조응적 영 대명사의 식별은 문장 내 영 대명사의 해결에 긍정적인 영향을 줄 수 있으며, 실험을 통해 절 간의 결속성을 고려한 제안한 방법이 문장 내 영 대명사 해결에 도움이 된다는 것을 확인할 수 있었다. The occurrence of null subjects in sentences is frequent in Korean. The use of these omitted elements is commonly found in Korean complex sentences, and can be seen as a linguistic device which enhances the cohesion between clauses. Based on the cohesion of clauses, this paper proposes a method for determining the intra-sentential anaphoricity of zero pronouns. Since the anaphoricity of zero pronouns can be understood as interactions that occur through anaphoric links between zero pronouns and the referents, the intra-sentential anaphoricity of a given zero pronoun can be determined by investigating structural relationships between clauses with zero pronouns and clauses with referents. Therefore, based on the results of intra-sentential anaphoricity determination, zero pronouns that are not intra-sentential anaphoric can be excluded from intra-sentential antecedent identification. The identification of these non-anaphoric zero pronouns can have a positive affect on intra-sentential zero pronoun resolution. Our experimental results show that the proposed method helps to resolve intra-sentential zero pronouns.

문장 내 영 조응어 해석을 위한 영대명사의 조응성 결정

김계성(Kye-Sung Kim),박성배(Seong-Bae Park),박세영(Seyoung Park),이상조(Sang-Jo Lee) 한국정보과학회 2010 정보과학회논문지 : 소프트웨어 및 응용 Vol.37 No.12

문서에서 생략된 요소가 지시하는 대상을 식별해 내는 작업은 기계 번역, 정보추출 등과 같은 자연언어처리 분야의 다양한 응용들을 위해 필요하다. 문장에서 생략된 요소들은 영조응사, 영대명사 등으로 불리며, 지시(reference)의 한 유형으로 간주되고 있지만, 모든 영형이 문서에서 명확하게 언급된 지시대상을 지시하지는 않는다. 이에 영형의 조응성을 결정하려는 연구가 최근 진행되고 있으며, 본 논문에서는 한국어에서 가장 빈번하게 나타나는 영형 주어(subject zero pronouns)의 문장 내 조응성 결정에 초점을 맞춘다. 주어진 영형과 선행사 후보들 간의 쌍대 비교(pairwise comparison)에 기반한 기존 연구와 달리, 본 논문은 비조응적 혹은 문장 간에서 해결 가능한 영형이 나타난 절의 구조를 직접 학습함으로써 영형의 문장 내 조응성을 결정한다. 실험에서 제안한 방법은 베이스라인보다 나은 성능을 보였으며, 영형의 조응성 결정은 향후 영형 조응어 해석에 긍정적인 영향을 줄 수 있을 것으로 기대된다. Identifying the referents of omitted elements in a text is an important task to many natural language processing applications such as machine translation, information extraction and so on. These omitted elements are often called zero anaphors or zero pronouns, and are regarded as one of the most common forms of reference. However, since all zero elements do not refer to explicit objects which occur in the same text, recent work on zero anaphora resolution have attempted to identify the anaphoricity of zero pronouns. This paper focuses on intra-sentential anaphoricity determination of subject zero pronouns that frequently occur in Korean. Unlike previous studies on pair-wise comparisons, this study attempts to determine the intra-sentential anaphoricity of zero pronouns by learning directly the structure of clauses in which either non-anaphoric or inter-sentential subject zero pronouns occur. The proposed method outperforms baseline methods, and anaphoricity determination of zero pronouns will play an important role in resolving zero anaphora.

조응성 정보와 중심화 이론에 기반한 영형 주어의 선행사 식별

김계성 ( Kye Sung Kim ),박성배 ( Seong Bae Park ),이상조 ( Sang Jo Lee ) 한국정보처리학회 2013 정보처리학회논문지. 소프트웨어 및 데이터 공학 Vol.2 No.12

본 논문은 지역적 응집성을 모델링하는 중심화 이론을 이용하여 한국어 영형대명사의 지시해결에 접근한다. 중심화 이론은 영어 대명사의 해결을 위해 널리 사용되고 있지만, 일본어, 한국어 등의 언어에서 나타나는 영형대명사 해결에 중심화의 프레임워크를 적용하는 데에는 많은 어려움이 따른다. Grosz et al의 중심화 이론은 지시적 표현들의 비조응적 사용을 고려하지 않으므로, 문서에 나타나는 비조응적 기능의 영형대명사가 중심화 이론을 이용한 영형대명사의 선행사 식별에 중요한 영향을 미친다. 본 논문은 이를 위해 먼저 절 간의 결속 관계를 이용하여 영형대명사, 특히 영형주어의 문장 내 조응성을 결정하고, 다음으로 중심화의 순위를 이용하여 그 영형의 선행사를 식별하는 방법을 제안한다. 실험을 통해 조응성 결정을 이용하는 제안한 방법이 이를 이용하지 않는 베이스라인 시스템보다 우수함을 알 수 있었다. This paper approaches the problem of resolving Korean zero pronouns using Centering Theory modeling local coherence. Centering Theory has been widely used to resolve English pronouns. However, it is much difficult to apply the centering framework for zero pronoun resolution in languages such as Japanese and Korean. Since in particular the use of non-anaphoric zero pronouns without explicit antecedents is not considered in the Centering Theory of Grosz et al., the presence of non-anaphoric cases negatively affects the performance of the resolution system based on Centering Theory. To overcome this, this paper presents a method which determines the intra-sentential anaphoricity of zero pronouns in subject position by using relationships between clauses, and then identifies antecedents of zero subjects. In our experiments, the proposed method outperforms the baseline method relying solely on Centering Theory.

줄기세포 연구의 윤리적 문제에 대한 연구자들의 인식조사

김옥주(Kim Ock-Joo),권복규(Ivo Kwon),김현철(Kim Hyeon-Cheol),김계성(Kim Kye-Seong),조성일(Cho Sung-Il),박은정(Pak Un-Jong) 한국생명윤리학회 2006 생명윤리 Vol.7 No.1

This study was based on a survey done in 2003, which asked stem cell researchers about what ethical problems stem cell and embryo research have. The fact that this study focuses on the problems acknowledged by stem cell researchers in Korea which is one of the few countries who nationally supported stem cell research makes this study meaningful. The study is particularly important at this moment after 2005 Hwang Woo Suk scandal, since it shows how even the researchers in the year 2003 worried about ethical problem from the beginning of stem cell research. We asked the stem cell researchers what the general public would think about ethical problems related with stem cell research. By doing so, we tried to find the contrast between the opinions of the stem cell researchers and the general public on ethical issues. It also demonstrates that they were very cautious about performing human embryonic cloning by somatic cell nuclear transfer. According to this study, many researchers were not supportive to embryonic cloning by nuclear transfer at that time. Furthermore, it proves that stem cell researchers have different point of views about the research according to their gender, religion and their stances.

Effect of Cholesterol Supplementation in Freezing Medium on the Survival and Integrity of Human Sperm after Cryopreservation

임정진,성수예,김계성,송승훈,이우식,윤태기,이동률,Lim, Jung-Jin,Sung, Su-Ye,Kim, Kye-Seong,Song, Seung-Hon,Lee, Woo-Sik,Yoon, Tae-Ki,Lee, Dong-Ryul The Korean Society for Reproductive Medicine 2008 Clinical and Experimental Reproductive Medicine Vol.35 No.3

목 적: 정자의 동결 과정에서 생길 수 있는 급격한 온도 차에 의한 동결 충격이나 동결 상해등에 의한 세포막의 손상, 세포의 기능 장애 등은 정자의 수정능에 영향을 미칠 수 있다. 본 연구에서는 인간 정자를 동결 보존하는 과정에서 콜레스테롤 전처리가 정자의 운동성 및 기능보존에 미치는 영향을 알아보고자 하였다. 연구방법: 본원을 내원한 14명 남성의 정자를 대상으로 콜레스테롤을 첨가하지 않은 대조군 (control)과 여러 농도의 콜레스테롤을 동결보존액에 첨가한 실험군에서 정자의 동결-융해 후 상태를 다음 3가지 방법으로 비교, 분석하였다. 1) 정자 분석, 2) calcium ionophore로 유도된 첨체 반응 검사, 3) 정자 염색질 구조 분석 (sperm chromatin structure assay). 결 과: 첫째로 인간 정자의 운동성은 $0.5{\mu}g$ 농도의 콜레스테롤을 첨가한 동결보존액에서 동결-해동하였을 경우, 콜레스테롤을 첨가하지 않은 군에 비해 유의적 차이를 보이며 증가하는 것을 확인하였다 ($33.46{\pm}1.48%$ vs. $30.10{\pm}1.07%$, p<0.05). 다음으로 동된 정자의 첨체 반응 검사에서도 콜레스테롤을 첨가한 동결보존액에서의 첨체 반응이 일어나는 정자의 비율이 첨가하지 않은 군에 비해 유의하게 높게 관찰되었다 ($53.60{\pm}1.60%$ vs. $47.40{\pm}1.86%$, p<0.05). 마지막으로 정자 염색질 구조 분석에서는 콜레스테롤을 첨가한 군이 첨가하지 않은 군에 비해 정자의 DNA손상이 적게 나타남을 확인하였다. 결 론: 본 실험은 동결보존액을 통한 정자 원형질막 내 콜레스테롤 함유량의 증가가 동결-융해 후 정자의 운동성과 수정능(capacitation status)을 증가시키고 DNA 손상을 방지하는 역할을 한다는 결과를 보여주었다. 이러한 결과를 통해 동결보존액 내 콜레스테롤의 첨가는 인간 정자의 동결보존 동안 발생할 수 있는 동결 상해를 줄여줄 수 있는 유용한 방법으로 사료된다. Objective: During cryopreservation process, cold shock and cryo-injury affect the fertilizing capacity of the sperm by damaging cell membranes with loss of functional integrity. A longstanding concept for preventing the cryo-damage is to stabilize the plasma membrane by incorporating cholesterol. This study was to determine the effects of cholesterol in freezing media on the motility and functional integrity of human sperm after cryopreservation. Methods: Control group (non-cholesterol treated) and different concentrations of cholesterol-treated sperm (14 healthy males) were frozen and thawed. After freezing and thawing of sperm, the quality of sperm was evaluated by sperm analysis, acrosome reaction test and sperm chromatin structure assay. Results: When human sperm were incubated in sperm freezing medium (SFM) containing $0.5{\mu}g$ cholesterol and then freezing/thawing, the motility of sperm have significantly improved compared to those untreated cholesterol ($33.46{\pm}1.48%$ vs. $30.10{\pm}1.07%$, p<0.05). The rate of calcium ionophore-induced acrosome reactions in post-thawed sperm was significantly higher than that ($53.60{\pm}1.60%$ vs. $47.40{\pm}1.86%$, p<0.05) in SFM containing cholesterol. Sperm chromatin structure assay revealed that DNA damage to the sperm in the cholesterol-treated group was lower than that of non-treated group. Conclusion: These results suggest that increased cholesterol content of sperm plasma membrane by supplementation of cholesterol in SFM improves sperm motility, capacitation status, and DNA integrity. Therefore, addition of cholesterol into SFM could be a useful for protecting human sperm from cold shock and cryo-injury during cryopreservation.

일반총설 : 최근 MicroRNA 연구 동향과 전망

조화자 ( Wha Ja Cho ),김계성 ( Kye Seong Kim ) 한국조직공학과 재생의학회 2007 조직공학과 재생의학 Vol.4 No.2

생쥐 배아줄기세포의 신경세포로의 빠른 분화유도

문성환 ( Sung Hwan Moon ),김정연 ( Jung Yean Kim ),김계성 ( Kye Seong Kim ) 한국조직공학과 재생의학회 2004 조직공학과 재생의학 Vol.1 No.2

Embryonic stem cells (ESC) are thought to be a powerful tool for cell replacement in degenerated or damaged cells, including those in central nerve system because ESC are known to be pluripotent and capable of differentiating into various cell types found in adult body. In general, ESCs are differentiated into specific cell lineages through the formation of embryoid body (EB). We demonstrated the direct differentiation of mouse embryonic stem cells (mESC) into neuronal cells in culture from mESC aggregation, which were cultured in suspension for only 48 hrs. To process the differentiation of ES aggregates, they were attached onto poly-L-ornithin and fibronectin coated plates (stage I). Then media was changed to early-differentiated media supplement N2 in DMEM/F12 (stage II), during aggregates were expanded fully. After 7 days, we changed media for late differentiation media supplement N2 and B27 in DMEM/F12 for 7 days (stage III). After total 15 days, differentiated cells were observed by immunnocytochemistry with neuronal lineage markers such as neuronal nuclei (NeuN), microtubule-associated proteins-2 (MAP2), and tubulin 3. In addition, RT-PCR analysis showed the gene expression of nestin, OTX2, MAP2. Nestin and OTX2 gene were detected in the neuronal precursor cells and then decreased in differentiated neuronal cells. However, expression of MAP2 gene expression was detected in late differentiated (stage III) cells. Taken together, newly developed neuronal differentiation system without EB formation may be efficient method to drive rapid differentiation mESC into neuronal cells.