아저해농도(亞沮害濃度)의 항균물질이 mutans streptococci의 세포표면성질과 독력인자에 미치는 영향

김영재,한세현,이상훈,장기택,김종철 大韓小兒齒科學會 2004 大韓小兒齒科學會誌 Vol.31 No.4

아저해농도(亞沮害濃度)란 세포의 성장을 저해하는 최소 저해 농도(minimum inhibitory concentration; MIC)이하의 농도를 말하는데, 적용된 화학물질의 동력학에 따라 항균물질은 반드시 이러한 농도로 존재하는 시기를 거치게 되며, 아저해농도의 항균물질은 세포의 성장을 저해하지는 않지만 세균의 대사와 성장에 스트레스로 작용하게 되어 세포의 성질과 독력인자 발현에 영향을 줄 수 있을 것이다. 본 연구는 여러 항균물질의 최소저해농도를 결정하고 아저해농도의 항균물질이 존재 시 세포 성질과 독력 인자에 미치는 영향을 알아보고, 치아우식증의 예방에 대한 화학적 접근법의 효용성을 조사하기 위해 계획되었다. 연구대상 세균으로는 mutans그룹 streptococci 중 두 가지 대표적인 세균종인 S. mutans (S. mutans Ingbritt)와 S. sobrinus (S. sobrinus 6715-7) 를 사용하였고 화학물질 8종 (Sanguinaria extract; SG, Chlorhexidine digluconate; CHX, Fluoride; F, Propolis; PP, Hydrogen peroxide; HP, Triclosan; TC, Sodium dodecyl sulfate; SDS, Cetylpyridinium chloride; CC) 을 단계 희석하여 배지에 첨가하여 최소저해농도를 구하였으며 아저해농도의 항균물질을 배지에 첨가하여 5% CO₂존재 하에 37℃에서 배양하여 이러한 항균물질을 첨가하지 않은 배지에서 배양한 세균과 성장속도, 산생성능, 체표소수성, 수산화인회석에의 부착능, glucan생성능, 세균응집능 등을 비교 관찰하였다. 아저해농도의 항균물질은 세포의 성장과 체표소수성, 타액 처리한 수산화인회석에 대한 세균의 부착과 glucan합성에 영향을 주는 것이 관찰되었다. 또한 12시간 배양 후 S. mutans와 S. sobrinus 모두에서 대조군에 비해 통계적으로 유의하게 최종 pH가 높게 나타나 산생성능이 억제되는 것이 관찰되었다 (p<0.05). 세균을 proteinase K로 전처리한 경우 처리하지 않았을 때 보다 세균응집역가가 증가하거나 응집이 관찰되지 않았다. 본 연구의 결과에 따르면 각각의 항균물질은 아저해농도에서도 알려진 작용기전과 유사하게 세균의 성질에 영향을 주었고 이러한 농도에서도 지속적으로 세균을 억제할 수 있었다. 따라서 이러한 항균물질의 사용은 치아우식증의 효과적 예방법의 하나가 될 수 있다. Subinhibitory concentrations (sub-MICs) refer to concentrations below minimum inhibitory concentrations (MICs). The antimicrobial agents may be present at relatively high concentration, at least higher than bacterial MIC and thereafter be desorbed off a surface and function at sub-MICs, perhaps by interfering with bacterial metabolism. Consequently, the aim of this study was to determine the effects of growth, in the presence of sub-MICs of antimicrobial agents, on the cell surface properties and virulence factors of mutans streptococci and to investigate the efficacy of a chemical approach in vitro. Streptococcus mutans Ingbritt and Streptococcus sobrinus 6715-7 were used. Eight antimicrobial agents (Sanguinaria extract;SG, Chlorhexidine digluconate;CHX, Fluoride; F, Propolis;PP, Hydrogen peroxide;HP, Triclosan;TC, Sodium dodecyl sulfate;SDS, Cetylpyridinium chloride; CC) were diluted serially in broth to determine MICs and to compare the growth rate, acid production, hydrophobicity, adhesion activity to saliva coated hydroxyapatite, glucan synthesis and cellular aggregation of experiment groups (in the presence of sub-MICs) with those of control (in the absence of antimicrobial agents). Sub-MICs of antimicrobial agents affected the growth of cells, hydrophobicity, and adhesion of bacteria to saliva coated hydroxyapatite and glucan synthesis. They also resulted in a significant reduction in pH after 12 hours (p<0.05). By cells pretreated with proteinase K. either the aggregation induced by antimicrobial agents was completely inhibited or the aggregation titers were markedly increased. According to the results of the present study, each antimicrobial agent at sub-MICs could affect similar as its known action mechanism and could continually inhibit cariogenic bacteria a t such concentrations. Thus, the use of these antimicrobial agents would be one of the effective methods to prevent dental caries.

부산항 해수유동의 G.U.I System 구축

김태경,김기철 東亞大學校 海洋資源硏究所 2003 硏究論文集 Vol.15 No.-

Busan port has been developed as the main hub port in the eastern asia. As the ship transportations increase, the risk of maritime accidents also increase. Maritime accidents result in marine pollutions such as oil or toxic material spill problems. As pollutant materials spread mainly in the direction of water movement, it is desirable to construct the real time prediction system of ocean circulation in the harbor as the effective strategy to minimize the pollution. In this study, the system to predict the depth-integrated currents forced by tide and wind at Busan port is developed using G.U.I. system.

선천성 일측성 폐정맥 폐쇄증 1 예

김철호,이계영,심영수,김건열,한용철,한성구,정희순,임정기,박재형 대한내과학회 1988 대한내과학회지 Vol.35 No.3

Unilateral pulmonary vein atresia is a rare congenital disease and is frequently associated with intracardiac anomalies. It is usually diagnosed in childhood and is very rarely diagnosed in adulthood. A case of unilateral pulmonary vein atresia in a 20-year old female is de- scribed. The relevant findings were symptoms of exertional dyspnea, roentgenographic evidence of decreased lung volume, increased interstitial infiltration with septal lines in the involved side (right), and aoscence of blood flow in a radionuclide perfusion scan. Pulmonary angiography showed an extremely small right pulmonary artery and thining of the peripheral branches, and nonvisualization of the draining pulmonary veins. Bronchial arteriography showed rommunication between the bronchial artery and the right pulmonary artery and it was drained to the left pulmonary artery. Cardiac catheterization showed no intracardiac anomaly. The right bronchography was normal; pulmonary function studies showed a pure restrictive pattern and markedly in creased physiologic dead space. MRI showed no visible right pulmonary vein.

갑상선 기능항진증에 병발된 주기성 마비 3예

최지훈,최경숙,김기훈,박병현,조정구 圓光大學校 醫科學硏究所 2001 圓光醫科學 Vol.16 No.1-2

Thyrotoxic periodic paralysis is characterized by intermittent flaccid paralysis of skeletal muscle, lasting several hours. The underlying pathophysiology of the syndrome is not yet to be well characterized and remains controversal, but reflects altered potassium and calcium dynamics as well as certain morphologic characteristics within the muscle unit itself. It occurs primarily in Asian populations with an overwhelming male preponderance and a higher association of specific HLA antigens. Precipitating factors include high carbohydrate ingestion, exercise, trauma, infection, alcohol ingestion, administration of epinephrine, thyroid hormone, or corticosteroid. If hypokalemia is present, potassium administration may help abort the attack, but the only definitive treatment is formation of euthyroid state. We discribed two patients with hypokalemic thyrotoxic periodic paralysis and one patient with normokalemic thyrotoxic periodic paralysis.

한국인 임신부에 있어서 영양소의 역가측정

최기영,김웅철,박기현,배도환 중앙대학교 의과대학 의과학연구소 1982 中央醫大誌 Vol.7 No.2

Animal and human studies indicated that inadequate diet for a prolonged period during pregnancy could injure mother, child, or both. In order to prevent this problem, maternal nutyitional status during pregnancy is very important and the evaluation of nutrition during pregnancy have been preceded by many authors in another countries. In Korea, nutrient intake studies of the pregnant women and nutrition surveys in adult by biochemical method have been performed, but there are no data nutrition surveys of Korean pregnant women have been made by biochemical method. In this regard, an exact biochemical titer of the nutrients and the degree of nutrient deficits in Korean pregnant women are needed. In this study, the mean titer of some nutrients and the degree of nutrient deficits by biochemical method in Korean pregnant women were assessed. The objected materials were consisted of 30 cases which had visited the departmant of Obstetrics & Gynecology, Chung Ang University Hospital for antenatal care(32wk-40wk) from March, 1981 to June, 1981. The cases with twin pregnancy, and the cases complicated with materal chronic wasting disease, diabetes, hydroamniosis, hypertensive disorder in pregnancy were excluded in this study. The results were as follows: 1. Mean titer of 6 hours urine execretion of thiamine, riboflavin and N'-methylniacinamide in Korean pregnant women was 44㎍, 466㎍, and 2.33㎎. 2. Mean titer of serum vitamin A, carotene, vitamin C, total protein, calcium, phosphorus, iron and total lipid was 48.1㎍, 154.7㎍, 0.8㎎, 7.0g, 9.8㎎ 3.5㎎, 93㎍, and 578㎎. 3. Percentage of nutrient deficits in Korean pregnant women based on the mean titer of Korean adults was as follow; thiamine-20%, N'-methylniacinamide-7%, total protein-5%, calcuim13%, iron-19%. 4. No cases were deficient in riboflavin, carotene, phosphorus, total lipid and the mean titer of riboflavin and carotene in Korean pregnant women were high compared with thw mean titer of Korean adults.

Nd:YAG 레이저 및 아크의 복합 용접에 관한 연구

이목영,김재웅,김기철 한국레이저가공학회 2003 학술발표대회 Vol.2003 No.1

두께 2.0mm 열연강판을 대상으로 GMA 용접과 Nd:YAG 레이저 용접의 복합화에 따른 용접성을 알아보았다. GMA 용접과 레이저 용접의 공정 변수를 제어하므로서 용접부 크기제어가 가능하였으며, 특히 합금량이 높은 경우에는 filler의 성분을 조절하여 용접비드의 야금학적/기계적 특성 제어가 용이하였다. 레이저-아크 하이브리드 용접은 알루미늄 혹은 고강도강과 같이 용접이 어려운 소재의 용접에 적당하였으며, 상대적으로 낮은 출력의 레이저를 사용하므로서 용접 cost의 저감이 가능하였다.

국부 마모 부품을 위한 레이저 표면강화 열처리에 관한 연구

이목영,김형준,김기철,김재웅 한국레이저가공학회 2002 학술발표대회 Vol.2002 No.1

두께 10mn 일반기계구조용강재를 사용하여 레이저 종류에 따른 표면경화 열처리특성에 관하여 알아보았다. 경화층의 형성은 레이저의 종류에 크게 영향을 받았는데, 표면경화 열처리를 위해서는 파장이 짧은 Nd-YAG 레이저를 사용하는 것이 유리하였다. 경화층의 최고경도는 700Hv 가량으로 높게 나타났으며, 레이저 표면경화 열처리는 상온에서 사용되는 부품의 내마모성 향상 특히 국부 마모를 겪는 부품에 효과적일 것으로 판단되었다.

供血者에서의 HBsAg 發現率과 生化學的 檢査値에 관한 硏究

문희주,윤기은,김승곤,라동진,김태전,박정오,최범열 서울保健大學 1988 論文集 Vol.8 No.1

Experiences of Latent Tuberculosis Infection Treatment for the North Korean Refugees

Kim, Beong Ki,Kim, Hee Jin,Kim, Ho Jin,Cha, Jae Hyung,Lee, Jin Beom,Jeon, Jeonghe,Kim, Chi Young,Kim, Young,Kim, Je Hyeong,Shin, Chol,Lee, Seung Heon The Korean Academy of Tuberculosis and Respiratory 2019 Tuberculosis and Respiratory Diseases Vol.82 No.4

Background: Tuberculosis (TB) is increasing in immigrants. We aimed to investigate the current status of latent tuberculosis infection (LTBI) treatment for North Korean Refugees (NKR) compared to South Koreans Contacts (SKC). Methods: TB close contacts in a closed facility of SKC and NKR who underwent LTBI screening in a settlement support center for NKR were analyzed retrospectively. Results: Among tuberculin skin test (TST) ${\geq}10mm$ (n=298) reactors, the males accounted for 72.2% in SKC (n=126) and 19.5% in NKR (n=172) (p<0.01). The mean age was higher in South Korea ($42.8{\pm}9.9years$ vs. $35.4{\pm}10.0years$, p<0.01). Additionally, the mean TST size was significantly bigger in NKR ($17.39{\pm}3.9mm$ vs. $16.57{\pm}4.2mm$, p=0.03). The LTBI treatments were initiated for all screened NKR, and LTBI completion rate was only 68.0%. However, in NKR, LTBI treatment completion rate was significantly increased by shorter 4R regimen (odds ratio [OR], 9.296; 95% confidence interval [CI], 4.159-20.774; p<0.01) and male (OR, 3.447; 95% CI, 1.191-9.974; p=0.02). Conclusion: LTBI treatment compliance must be improved in NKR with a shorter regimen. In addition, a larger study regarding a focus on LTBI with easy access to related data for NKR should be conducted.

Report on the Cooperative Experimental Study Program

Kim, Hun-Chol,Yang, Seung-Il,Lee, Seung-Hee,Kim, Eun-Chan,Kang, Kuk-Jin,Lee, Young-Gill,Kim, Yoon-Ho,Lee, Kwi-Joo,Kwak, Young-Ki,Joa, Soon-Won,Kim, Hyo-Chul,Van, Suak-Ho,Kim, Wu-Joan,Song, Mu-Seok,Cho 대한조선학회 1987 大韓造船學會誌 Vol.24 No.3

The present paper describes the results of the cooperative experimental study organized by the Resistance Committee of the Korea Towing Tank Conference, which aims to improve model testing technique and accuracy and to self-evaluate their own capabilities. A Series 60, $C_b=0.60$ model was tested at the towing tanks of Korea Institute of Machinery & Metals, Hyundai Maritime Research Institute, Seoul National University, and Inha University. Results for total resistance, wave pattern analysis, wave pattern analysis, wave profile, trim & sinkage and wake measure ments are presented.