Methotrexate가 Mouse 간세포의 미세구조에 미치는 영향

정호삼,장혁순,이규식 한양대학교 의과대학 1987 한양의대 학술지 Vol.7 No.2

Methotrexate (MTX), folic acid analog, has been widely used in the therapy of psoriasis and also used in the chorionic adenoma and acute lymphatic leukemia. Methotrexate inhibits not only DNA synthesis but also RNA and protein synthesis. It has been reported that during the therapy, its cytotoxicity leads to necrosis of the epithelium of the renal tubules, hair loss and hepatic fibrosis. So the author undertook the present study to pursue the effect of methotrexate on the cytoplasmic organelles of hepatic cells. Albino mice, ICR strains, weighing 20gm were used experimental animals. The experimental animals were killed at 24, 48, 72 and 96 hours after administrations of 15 mg/kg of MTX. The specimens obtained from liver were prefixed in Millonig's solution and post-fixed in the 1% osmic acid. After specimens were dehydrated and embedded in the Epon 812, ultrathin sections were made and double stained with uranyl acetate and lead citrate. And these preparations were observed with the electron microscope. The results were as follows. 1. The majority of mitochondria was hypertrophied and some mitochondria were irregular shaped, its double membrane and crests disappeared in the mouse liver of the 24 hours-MTX treated group. 2. Golgi complexes were atrophied in the 48 hours-MTX treated group and cisternae of the Golgi apparatus were hypertrophied and vesicular formation was observed in the 72 hours-MTX treated group. 3. The cisternae of the rough endoplsmic reticulum wer dilated and sacculated, but the detachment of membrane bound ribosomes was observed. 4. Lysosomes and autophagic vacuoles were increased in number with time. Consequently, it is suggested that MTX would induced the damge of the organelles of the hepatic parenchymal cells in mice.

손목관절 관절원반의 퇴행변화 및 발달뼈의 안쪽관절면에 관한 연구

이규석,정인혁 관동대학교 의과학연구소 2001 關東醫大學術誌 Vol.5 No.1

This study was performed to observe the degenerative changes of the articular disc of the wrist joint and the medial facet of the lunate. The anteroposterior length of the articular disc was 15.3±2.2mm, the width was 10.6±1.1mm and the thickness was 1.5 ±0.3mm at the central portion, 4.7±0.9mm at the peripheral portion. The degenerative changes were appeared as perforation and the incidence was 68.9%. The perforation classified into the three types. Type I is the tearing perforation and the incidence was 33.3%. Type II is the widespread perforation and the incidence was 31.1%. Type III is round perforation and the incidence was 4.5%. The medial facet of the lunate was a variation of carpal bones. The articular facet was formed between lunate and hamate and the incidence was 62.2%. The width of the facet was 3.5(1.0-5.9)mm in average. The articular facet undergo the degenerative changes as the erode of the articular cartilage. The incidence of these erode occurs 10.7% at lunate, 14.3% at hamate,14.3% at both carpal bones.

Lysozyme 陽性 胃癌細胞 및 大障癌 細胞에 對한 免疫組織化學的 硏究

吳忠南,李珉徹,曺圭赫 全南大醫大 1985 전남의대학술지 Vol.22 No.2

한국인 혀동맥의 형태

김희진(KIM Hee Jin),강민규(KANG Mill Kyu),김진학(KIM Jm Hak),박재한(PARK Jae Han),이상섭(LEE Sang Heon),이상헌(LEE Sang Sup),정인혁(CHUNG In Hyuk2) 대한체질인류학회 1997 대한체질인류학회지 Vol.10 No.2

연구자들은 한국인 어른 남녀 시신의 머리와 목 61 을 대상으로 깊은 층 육안해부를 시행하여 혀동맥의 형태를 조사하였다 혀동맥이 일어나는 유형은 위갑상동맥, 혀동맥, 그리고 얼굴동맥이 바깥목동액에서 따로 가지를 내어 나뉘는 경우가 563% 호 가장 않았으며, 얼굴동맥과 혀동맥이 강은 가지에서 얼어나 나뉘는 경우 (312%), 그리고 위 강상동액과 혀동맥이 같은 가지에서 나뉘는 경우 (12 5%) 등이 있었다. 혀동맥과 혀동맥의 둘째 부분은 덮는 목뿔혀근 과의 영대학적 관계는 각각 혀동맥의 첫째 부분이 목뿔혀근 뒤에서 심하게 휘어져 깊은 층으로 들어가는 유형 (41 2 %), 그리고 혀동맥의 첫째 부분이 목뿔혀근의 뒤쪽 근육모셔리 바로 뒤흘 지나 깊은 층으로 들어가는 경우가 661% 로 가장 많았다 목뿔혀근 깊은층에서 혀동맥의 둘째 부분이 달리는 양상은 급하게 위쪽으로 꺾역 달리다가 다시 앞쪽으로 꺾여 혀의 깊은 곳으로 들어가는 경우와 목뿔빼에서 혀쪽으로 완만한 굽이플 이루며 올라가는 경우가 비슷한 반도로 관찰되었다. 입안바닥에 분포하는 혀밑동맥이 혀동맥 셋째 부분에서 나오는 경우슨 전체의 590% 에서만 관창되었으며 그 외는 대부분 얼굴동맥의 턱끝 및동맥 가지가 턱옥뽕근응 옳고 입안바닥에 분포하였다. 따라서 연구자들은 한국인 업안바 닥에는 혀동액이 전체의 59%에서만 분포하며 그외는 영굴동액의 턱끝밑동맥 가지 , 그리고 기타 다른 동맥의 가지들이 분포한다는 사실을 확인하였다

비글개에서 l-muscone의 급성독성 및 아급성독성시험 연구

유아선,권오경,성하정,곽형일,방명주,박대규,정규혁,윤효인,조명행 성균관대학교 약학연구소 1998 成均藥硏論文集 Vol.10 No.1

Single and 4 weeks oral administration of l-muscone, a major active ingredient of musk, to beagle dogs of both sexes were performed to investigate both acute and subacute toxicity. Beagle dogs(3 males and 3 females) in acute experiments were administered orally with single dosage of 2,000 ㎎/㎏ and groups of 9 male and 9 female beagle dogs in subacute experiments were given daily different dosage of l-muscone, 0.2㎎/㎏/day(low dosage group), 2 ㎎/㎏/day(middle dosage group), or 20 ㎎/㎏day(high dosage group) once a day for 4 weeks by oral route according to the Established Regulation of Korean Food and Drug Administration(1996.4.16). LD_50 value for beagle dogs was more than 2,000 ㎎/㎏ on oral route for both male and females. In animals administered with l-muscone, there were neither dead animals nor significant changes of body weights. In addition, no differences were found between control and treated groups in clinical signs, urinalysis, eye examination, hematology, serum chemistry, organ weight and other findings. No histolopathological lesions were observed in both control and treatment groups. Above data strongly suggest that l-muscone in beagle dogs is considered to be safe.

Upper Bounds for the Performance of Turbo-Like Codes and Low Density Parity Check Codes

Chung, Kyu-Hyuk,Heo, Jun The Korea Institute of Information and Commucation 2008 Journal of communications and networks Vol.10 No.1

Researchers have investigated many upper bound techniques applicable to error probabilities on the maximum likelihood (ML) decoding performance of turbo-like codes and low density parity check (LDPC) codes in recent years for a long codeword block size. This is because it is trivial for a short codeword block size. Previous research efforts, such as the simple bound technique [20] recently proposed, developed upper bounds for LDPC codes and turbo-like codes using ensemble codes or the uniformly interleaved assumption. This assumption bounds the performance averaged over all ensemble codes or all interleavers. Another previous research effort [21] obtained the upper bound of turbo-like code with a particular interleaver using a truncated union bound which requires information of the minimum Hamming distance and the number of codewords with the minimum Hamming distance. However, it gives the reliable bound only in the region of the error floor where the minimum Hamming distance is dominant, i.e., in the region of high signal-to-noise ratios. Therefore, currently an upper bound on ML decoding performance for turbo-like code with a particular interleaver and LDPC code with a particular parity check matrix cannot be calculated because of heavy complexity so that only average bounds for ensemble codes can be obtained using a uniform interleaver assumption. In this paper, we propose a new bound technique on ML decoding performance for turbo-like code with a particular interleaver and LDPC code with a particular parity check matrix using ML estimated weight distributions and we also show that the practical iterative decoding performance is approximately suboptimal in ML sense because the simulation performance of iterative decoding is worse than the proposed upper bound and no wonder, even worse than ML decoding performance. In order to show this point, we compare the simulation results with the proposed upper bound and previous bounds. The proposed bound technique is based on the simple bound with an approximate weight distribution including several exact smallest distance terms, not with the ensemble distribution or the uniform interleaver assumption. This technique also shows a tighter upper bound than any other previous bound techniques for turbo-like code with a particular interleaver and LDPC code with a particular parity check matrix.

상호작용 이동통신 사용자에 대한 비직교 다중접속 시스템의 BER 성능 향상 : ML 검출 관점

정규혁(Kyu-Hyuk Chung) 한국전자통신학회 2020 한국전자통신학회 논문지 Vol.15 No.5

5G 이동통신 네트워크에서, 비직교 다중접속은 채널 용량을 높일 수 있는 기술로 각광받고 있다. 비직교 다중접속에서는, 다수 사용자가 채널 자원을 공유하여 신호를 동시에 전송 가능하다. 최근, 강 채널에 대해, 상호작용 이동통신 사용자의 성능이 비상호작용 이동통신 사용자 비해, 저하되는 연구가 보고되었다. 본 논문에서는, 이러한 문제를 해결하기 위해 ML 수신기를 제안한다. 먼저, ML 수신기의 BER의 폐쇄형 표현식을 유도하고, 이상적인 완벽한 SIC 수신기의 BER과 비교하여, ML 수신기의 BER이 향상되었음을 보여준다. 또한, 이론적인 분석에 기초한 모의실험을 진행하고 ML 수신기의 성능 우수성을 입증한다. In the fifth generation (5G) mobile networks, non-orthogonal multiple access (: NOMA) has been considered as a promising technology, to increase the channel capacity. In NOMA, the multiple users share the channel resources and multiplex simultaneously. Recently, for the stronger channel user, it was reported that the bit-error rate (: BER) performance with interactive mobile users is degraded, compared to the BER of non-interactive users. In this paper, in order to improve such degraded BER performance, we propose the maximum-likelihood (: ML) receiver. First, the closed-form expression for the BER of the ML receiver is derived, and then it is shown that the BER of the ML receiver is improved, compared with the BER of the ideal perfect successive interference cancellation (: SIC) receiver. Additionally, based on the analytical expression, Monte Carlo simulations validates the above-mentioned results.

Etiology and Patterns of Maxillofacial Fractures in 518 patients in Korea

Il-Hyuk Chung,Eun-Kyung Lee,Chung-Kyu Yoo,Chang-Joo Park,Seung-Il Song,Kyung-Gyun Hwang 대한구강악안면외과학회 2008 대한구강악안면외과학회지 Vol.34 No.1

Purpose: Different patterns in the causes of maxillofacial injury are thought to correlate with socioeconomic status and regional environment. This study investigated maxillofacial fractures in order to analyze maxillofacial trauma characteristics and the relationship between the causes and injury patterns in Korea. Material and methods: A total of 518 patients with maxillofacial fractures who were treated at the Seoul National University Boramae Hospital between 1996 and 2004 were retrospectively analyzed. Data were obtained from the patients’medical records and radiographs. The male to female ratio in the patient group was 2.78:1, and the mean age was 32.3 years. Results: Midfacial fractures were the most common location of injury (46.1%). The most common etiologic factor was an activity associated with daily life (42.6%) including falls, stumbling, and collisions. The second most common cause was assault (32.4%), followed by traffic accidents (13.7%). In the case of midfacial fractures and mandibular fractures, assault was the most common etiologic factor, whereas in the case of alveolar bone fractures, activities associated with daily life were the most common cause. With regard to age groups, assault was the most common cause for patients between 10 and 39 years old and an activity associated with daily life was the most common cause in those under 10 years and over 40 years. Conclusions: This study concluded that activities associated with daily life and assault causes a large proportion of Korean maxillofacial injuries and that preventive measures should be implemented in order to minimize these risks.

Basic Principles of the Validation for Good Laboratory Practice Institutes

Cho, Kyu-Hyuk,Kim, Jin-Sung,Jeon, Man-Soo,Lee, Kyu-Hong,Chung, Moon-Koo,Song, Chang-Woo Korean Society of ToxicologyKorea Environmental Mu 2009 Toxicological Research Vol.26 No.1

Validation specifies and coordinates all relevant activities to ensure compliance with good laboratory practices (GLP) according to suitable international standards. This includes validation activities of past, present and future for the best possible actions to ensure the integrity of non-clinical laboratory data. Recently, validation has become increasingly important, not only in good manufacturing practice (GMP) institutions but also in GLP facilities. In accordance with the guideline for GLP regulations, all equipments used to generate, measure, or assess data should undergo validation to ensure that this equipment is of appropriate design and capacity and that it will consistently function as intended. Therefore, the implantation of validation processes is considered to be an essential step in a global institution. This review describes the procedures and documentations required for validation of GLP. It introduces basic elements such as the validation master plan, risk assessment, gap analysis, design qualification, installation qualification, operational qualification, performance qualification, calibration, traceability, and revalidation.

5G 시스템에서 상관 정보원의 비직교 다중접속을 위한 음수의 상관관계 계수 B2S 사상

정규혁(Kyu-Hyuk Chung) 한국전자통신학회 2020 한국전자통신학회 논문지 Vol.15 No.5

본 논문에서는, 상호작용 이동통신 사용자의 비직교 다중접속에서 강채널 사용자의 저하된 BER 성능을 향상하기 위해 음수의 상관관계 계수 B2S 사상을 제안한다. 먼저, 음수의 상관관계 계수 B2S 사상 수신기의 BER의 폐쇄형 표현식을 유도하고, 이상적인 완벽한 SIC 수신기와 양수의 상관관계 계수 수신기의 BER과 비교하여, B2S 수신기의 BER이 향상되었음을 보여준다. 또한, 이론적인 분석에 기초하여 SNR 이득을 구하여 음수의 상관관계 계수 B2S 사상 수신기의 성능 우수성을 입증한다. In this paper, in order to improve the degraded BER performance of the stronger channel user in non-orthogonal multiple access(: NOMA) with interactive mobile users, we propose the negative correlation bit-to-symbol(: B2S) mapping. First, the closed-form expression for the BER of the negative correlation B2S mapping receiver is derived, and then it is shown that the BER of the negative correlation B2S mapping receiver is improved, compared with those of the ideal perfect successive interference cancellation(: SIC) receiver and positive correlation receiver. Additionally, based on the analytical expression, signal-to-noise(: SNR) gain is calculated, and the superiority of the negative correlation B2S mapping receiver is validated.