K⁺ 통로 조절 약물이 마우스 골격근의 피로현상에 미치는 영향

이기호,류판동,이문한,이항,Lee, Ki-ho,Ryu, Pan-dong,Lee, Mun-han,Lee, Hang 대한수의학회 1995 大韓獸醫學會誌 Vol.35 No.2

The density of ATP-sensitive potassium($K_{APT}$) channels, that open as intracellular ATP concentration falls below a critical level, is very high in skeletal muscle surface membrane and those high density may imply that $K_{ATP}$ channels have very important physiological roles. To elucidate a role of $K_{ATP}$ in relation to fatigue, the modulating effects of potassium channel openers and blockers on the fatigue velocity(FV) of mouse extensor hallucis longus muscle(EHL) were investigated in vitro. Twitch contraction was induced by an electrical field stimulation (EFS: 24-48V, 20ms, 0.2-4Hz) and resulting contraction force was isometrically recorded. The twitch forces were gradually decreased to 25% of initial contraction force(ICF) in $37.52{\pm}1.55sec$($mean{\pm}s.e.m.$, n=135), indicating the fatigue phenomena. The mean velocity for development of the fatigue was measured during the period that twitch force decreased to half($FV_{0/0.5}$) and during the period from half to 25%($FV_{0.5/0.25}$) of ICF. The fatigue was induced once every one hour and the tissue response was stable for up to 4 hours. In control condition, ICF was $5.8{\pm}0.12g$ (n=144) and decreased to 50% of ICF with the mean fatigue velocity of $0.182{\pm}0.006g/sec$($FV_{0/0.5}$, n=135) and from 50% to 25% of ICF with $0.084{\pm}0.004g/sec$($FV_{0.5/0.25}$, n=135). Cromakalim($50{\mu}M$) significantly increased $FV_{0.5/0.25}$(n=4). Glibenclamide($IC_{50}>50{\mu}M$), $Ba^{2+}$($IC_{50}=10{\mu}M$), 4-aminopyridine($FV_{0/0.5}$, $IC_{50}=0.5mM$; $FV_{0.5/0.25}$, $IC_{50}=2mM$) decreased both $FV_{0/0.5}$ and $FV_{0.5/0.25}$ concentration-dependently up to 75%. $TEA^+$(30mM), E-4031($10{\mu}M$), tolbutamide(1mM) decreased $FV_{0.5/0.25}$, but apamin(300nM) and $TEA^+$(10mM) showed no significant effects. Our results suggest that activation of the $K_{ATP}$ channels may be major cause of $K^+$ outflux during development of the fatigue and the isolated EHL muscle could be an useful experimental preparation in studying the fatigue phenomena in skeletal muscle. In addition, the possibility of activation of delayed rectifier during the fatigue development remains to be studied further.

Clinical Efficacy of Latex Cover for Dental Handpiece

이기호,백동헌,Lee, Ki-Ho,Paek, Dong-Heon Korean Academy of Orofacial Pain and Oral Medicine 2009 Journal of Oral Medicine and Pain Vol.34 No.3

The purpose of this study was to investigate the clinical efficacy of latex cover developed for dental handpiece on contamination of microorganisms during dental treatment and to determine whether it can be an alternative to conventional sterilization such as autoclaving. E. fecaelis was used as a experimental microorganism instead of oral flora. Experimental bowl with 2 cm of rectangular cavity was fabricated for handpiece operating instead of oral cavity. Latex covers ($Orokeeper^{(R)}$, Orobiotech Co., Korea) and several handpieces were used after sterilization by autoclave. Four experiments were performed to evaluate bacterial contamination related with (1) various parts of dental handpiece, (2) swabbing time with alcohol sponge, (3) postoperative air-water spraying time and (4) consecutive use of latex covers without autoclaving. The results show that face of handpiece uncovered with latex cover was severely contaminated than the covered area and that most bacteria were removed by swabbing face and head area of dental hand-piece and by air-water spraying more than 15 seconds nearly up to the level of sterilization. Conclusively it can be suggested that use of latex cover for handpiece during dental procedure, swabbing with alcohol sponge is air-water spraying for more than 15 seconds after use of dental handpiece should be very useful and practical for prevention of cross infection and should be an alternative method for the sterilization of dental handpiece under some difficult situations not being able to sterilize a handpiece with autoclave.

회원의 편지

이기호,Lee, Gi-Ho 한국자연공원협회 1990 한국자연공원 Vol.49 No.-

학위논문 전문데이터베이스 구축 및 서비스환경 구현

이기호,김진숙,윤화묵,Lee, Kyi-Ho,Kim, Jin-Suk,Yoon, Wha-Muk 한국정보처리학회 2000 정보처리논문지 Vol.7 No.1

1990년대 중반부터 다양하고 강력한 문서편집기의 보편화와 더불어 국내외의 대학에서는 책자형태의 논문제출과 동시에 전자형태 학위논문의 제출을 의무화하고 있다. 그러나 제출된 방대한 야의 전자형태의 논문들은 한글, MS-Word, Latexe 등 다양한 문서편집기로 작성되었고 문서형식의 표준화가 이루어지지 않아 효율적으로 활용되지 못하고 있는 실정이다. 본 논문에서는 다양한 형태로 존재하는 학위논문들을 하나의 통일된 중간포맷으로 변혼하고, 변환된 논물들을 전문데이터베이스(Full Text Datsbase)화하여 이를 인터넷을 통해 효육적으로 검색하고 서비스하기 위한 학위논문 전문검색시스템을 구현한다. Form the middle of 199os, most universities in Korea have requested their students to submit not only the original text books but also their Electronic Theses and Dissertations(ETD) for masters degree and doctorates degree. The ETD submitted by the students are usually developed by various kinds of word processors such as MS-Word, LaTex, and HWP. Since there is no standard format for ETD to merge various different formats yet, it is difficult to construct the integrated database that provides full-tex service. In this paper, we transform three different ETD formats into a unified one, construct a full-text database, and implement the full-text retrieval system for effective search in the Internet environment.

표준 기술동향 - 무선네트워크 가상화를 위한 핵심 기술

이기호,박종호,지영하,안태효,Lee, Gi-Ho,Park, Jong-Ho,Ji, Yeong-Ha,An, Tae-Hyo 한국정보통신기술협회 2010 TTA저널 Vol.128 No.-

A Case Report : TMJ Osteoarthritis in a Patient with Renal Osteodystrophy

이기호,Lee, Gi-Ho The Korean Academy of Orofacial Pain and Oral Medi 2013 Journal of Oral Medicine and Pain Vol.38 No.3

Renal osteodystrophy(RO) is characterized by skeletal changes in patients with renal disease and developed as a result of alterations in the metabolism of calcium, phosphate and secondary hyperparathyroidism. Bony changes in the craniofacial region include decreased bone density, radiolucent lesions(brown tumors), depletion of cortical bone and loss of lamina dura, but such changes rarely occur in the temporomandibular joint(TMJ). We report an uncommon case of bony changes and pain of both TMJs in a patient with RO. A 41-year-old man with RO came to our clinic due to TMJ pain and sounds. Occlusal change was also reported. Radiographs revealed degenerative changes of the both condyles. The patient had medical history of renal cancer therapy and hemodialysis. The patient was diagnosed with TMJ arthritis of RO and referred for systemic management through medication of calcium and vitamin D and parathyroidectomy. At 15-month follow-up, most of TMD symptoms disappeared and second radiographs revealed that bone density and cortical thickness of the mandible increased and the skeletal outline of the both condyles became relatively clear. As bony changes may begin in the early stage of the renal disease, dentists should be alert to detect the sign of the disease. In addition, it is important to differentiate TMJ arthritis of systemic cause because the treatment protocol is quite different. 신성골이영양증 (Renal osteodystrophy)은 만성 신질환 환자에서 관찰되는 골격성 변화를 특징으로 하는 질환으로 칼슘과 인 대사의 변화, 그리고 이차성 부갑상선 기능항진증의 결과로 나타난다. 방사선학적으로 지골의 말단, 장골과 악골 부위의 골막하 부위의 침식을 흔하게 관찰할 수 있다. 악안면 영역에서 골변화는 골밀도의 감소, 방사선 투과성 병소 (갈색 종양 : brown tumor), 피질골의 비박화와 치조백선의 소실을 보인다. 그러나 이러한 골변화가 악관절에 발생하는 것은 흔치 않은 일이다. 본 증례는 양측 하악 과두의 골변화를 보인 신성골이영양증 환자를 보고하고자 한다. 지난 10년 간 혈액 투석 치료와 3개월 전 신장암 수술 병력이 있는 41세 남자 환자가 좌측 턱의 통증을 주소로 2011년 2월 단국대학교 치과대학부속 치과병원 구강내과에 내원하였다. 양측 악관절의 골관절염과 유사한 방사선학적 소견을 보였고, 전치부 개방교합이 관찰되었다. CBCT를 이용한 방사선학적 특징과 생화학적 지표를 통해 신성골이영양증으로 인한 양측 턱관절의 골관절염으로 진단 되어 환자는 내과에서 신성골이영양증의 치료 방법의 하나인 칼슘 및 비타민 D 복용고 부갑상선 절제술을 시행 받았고, 그 동안 턱관절의 통증 조절을 위해 본원에서는 행동 요법과 약물 치료, 물리치료만 시행하였다. 약 1년 3개월 후 재검사에서 하악골의 골밀도와 피질골 두께가 증가하였고, 하악 과두 외형이 비교적 명확하게 바뀌었다. 골변화는 만성 신장 질환의 초기 단계부터 시작되므로 치과의사는 이러한 질환의 징후 및 가능성을 신속히 감별할 수 있어야 한다. 또한 골관절염과 신성골이영양증의 치료 프로토콜이 다르기 때문에 두 질환을 감별하는 것이 중요하다.

제주시 도로변에서의 에어로졸의 입경별 분포 특성

이기호,김수미,허철구,Lee, Ki-Ho,Kim, Su-Mi,Hu, Chul-Goo 한국환경과학회 2021 한국환경과학회지 Vol.30 No.9

Measurements on mass size distribution of roadside aerosols were obtained in downtown Jeju City from July 2018 to May 2020 using an 8-stage cascade impactor sampler and the compositions of aerosols were analyzed. The mass size distribution of total aerosols was bimodal with aerosols existing in both the fine and coarse modes. The mass size distributions of Na⁺, Mg²⁺, Ca²⁺, Cl^-, NH₄⁺ and SO₄^2- were unimodal, whereas that of K⁺ was bimodal. For NO₃^-, the size distribution in winter and spring was bimodal with the peaks in both fine and coarse modes, whereas for summer and autumn the distribution was unimodal with a peak in the coarse mode. NH₄⁺ was found to co-exist with SO₄^2- in the fine mode with an average molar ratio of [NH₄⁺]/[SO₄^2-] equal to 2.05. Good correlation was observed between NO₃^- and NH₄⁺ in the fine mode particles in spring and winter. Based on the value of the marine enrichment factor for Cl^-, Mg²⁺, K⁺, Ca²⁺ and SO₄^2-, it may be inferred that a major part of the roadside aerosols in downtown Jeju City was largely contributed by terrigenous sources, although the influence of sea salt was normally present.

Rat에서 $Na^{+}-K^{+}$ATPase 활성도와 $Na^{+},\;K^{+}$ 배설에 미치는 질산 우라늄의 영향

이기호,윤택구,Lee, Kee-Ho,Yun, Taik-Koo 대한방사선방어학회 1989 방사선방어학회지 Vol.14 No.1

우라늄 피폭으로 발생하는 다뇨증과 급성 신부전증의 원인을 밝히기 위하여, 질산 우라늄을 정맥주사한 후 소변으로 배설되는 $Na^{+},\;K^{+}$의 전해질 양과 $Na^{+}-K^{+}$ adenosine triphosphatase($Na^{+}-K^{+}$ATPase) 활성도 변화를 측정하였다. 질산 우라늄 투여 24시간 이내에 $Na^{+},\;K^{+}$의 배설량이 크게 증가 하였고, 투여 3일 후에는 대조군과 비교하여 유의하게 감소하였다. 이때 $Na^{+},\;K^{+}$의 소변내 농도도 정상 대조군 범위 이하였다. 한편 $Na^{+}-K^{+}$ATPase활성은 투여 3일후에 고농도 질산 우라늄 투여 (30mg/kg BW) 시에만 감소 하였고, 저농도 투여군(5mg/kg BW, 15mg/kg BW) 에서는 활성 변화가 없었다. In order to evalulate the cause of polyuric acute tubular necrosis, we measured electrolytes, $Na^{+}\;and\;K^{+}$ excreted in urine, and activities of $Na^{+}-K^{+}$adenosine triphosphatase ($Na^{+}-K^{+}$ATPase) Excretion of $Na^{+}\;and\;K^{+}$ significantly increased in 24hr exposure on the uranyl nitrate and then decreased below the normal level after 3 days. The concentration of $Na^{+}\;and\;K^{+}$ in urines of the rats treated uranyl nitrate was less than that of the normal rats. The activities of $Na^{+}-K^{+}$ATPase decreased only in the group treated with high dose group of uranyl nitrate (30mg/kg BW) on the 3rd day but were not changed in the low dose groups(5 mg/kg BW and 15mg/kg BW).

제주시 지역 미세먼지의 변동과 화학적 구성 특성

이기호,김수미,김길성,허철구,Lee, Ki-Ho,Kim, Su-Mi,Kim, Kil-Seong,Hu, Chul-Goo 한국환경과학회 2020 한국환경과학회지 Vol.29 No.5

This study investigated the nitrate formation process, and mass closure of Particulate Matter (PM) were calculated over the urbanized area of Jeju Island. The data for eight water-soluble inorganic ions and nineteen elements in PM_2.5 and PM₁₀ were used. The results show that the nitrate concentration increased as excess ammonium increased in ammonium-rich samples. Furthermore, nitrate formation was not as important in ammonium-poor samples as it was in previous studies. According to the sum of the measured species, approximately 45~53% of gravimetric mass of PM remained unidentified. To calculate the mass closure for both PM_2.5 and PM₁₀, PM chemical components were categorized into secondary inorganic aerosol, crustal matter, sea salt, trace matter and unidentified matter. The results by the mass reconstruction of PM components show that the portion of unidentified matter was decreased from 52.7% to 44.0% in PM_2.5 and from 45.1% to 29.1% in PM₁₀, despite the exclusion of organic matter and elemental carbon.

기하학 정보를 이용한 3차원 모델 검색

이기호,김낙우,김태용,최종수,Lee Kee-Ho,Kim Nac-Woo,Kim Tae-Yong,Choi Jong-Soo 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.10C

본 논문은 3차원 모델의 모양 기반 검색을 하기 위한 모델의 특징을 추출하는 방법을 제시한다. 3차원 모델의 특징 기술자는 모델에 대한 위치, 회전, 크기 변환에서 그 특징이 불변해야 하기 때문에, 모델을 정규 좌표계로 표시하기 위한 선(先)처리 작업이 필요하다. 우리는 선처리 작업을 위해서 주성분 분석 방법을 사용하였으며, 이 방법은 최소 경계 상자와 외접구의 생성을 위해서도 이용되었다. 제안한 알고리즘은 다음과 같다. 반지름 1인 외접구를 만들고, 구의 중심에 3차원 모델을 위치시킨 후, 반지름이 다른 동심구($r_i=i/n,\;i=1,2,{\ldots},n$)를 생성하고, 이 동심구들과 모델이 접하는 면을 구한 다음 그 면에 대한 곡률을 계산한다. 여기서 구한 곡률을 3차원 모델의 특징 기술자로 사용하게 된다. 실험 결과는 타 알고리즘에 비해 제안하는 방법이 상대적으로 적은 빈(bin) 수를 가졌음에도 불구하고 ANMRR 평가 함수에 의해 최소 0.1에서 0.6 이상의 성능 개선 효과가 나타나고 있음을 보여 준다. 본 논문은 색인 기법으로 $R{^*}-tree$를 사용하였다. This paper presents a feature extraction method for shape based retrieval of 3D models. Since the feature descriptor of 3D model should be invariant to translation, rotation and scaling, it is necessary to preprocess the 3D models to represent them in a canonical coordinate system. We use the PCA(Principal Component Analysis) method to preprocess the 3D models. Also, we apply that to make a MBR(Minimum Boundary Rectangle) and a circumsphere. The proposed algorithm is as follows. We generate a circumsphere around 3D models, where radius equals 1(r=1) and locate each model in the center of the circumsphere. We produce the concentric spheres with a different radius($r_i=i/n,\;i=1,2,{\ldots},n$). After looking for meshes intersected with the concentric spheres, we compute the curvature of the meshes. We use these curvatures as the model descriptor. Experimental results numerically show the performance improvement of proposed algorithm from min. 0.1 to max. 0.6 in comparison with conventional methods by ANMRR, although our method uses .relatively small bins. This paper uses $R{^*}-tree$ as the indexing.