Clinical Features and Correlation With Congenital Missing Teeth of Delayed First Permanent Molar

이명연,이효설,송제선,이제호,최병재,김성오,김승혜,Lee, Myeongyeon,Lee, Hyoseol,Song, Jeseon,Lee, Jaeho,Choi, Byungjai,Kim, Seongoh,Kim, Seunghye Korean Academy of Pediatric Dentistry 2017 大韓小兒齒科學會誌 Vol.44 No.1

국소적, 전신적 요인을 동반하지 않는 제1대구치의 맹출 지연은 해당 치아의 발육 지연을 동반한다. 본 연구의 목적은 제1대구치의 발육지연의 임상적 양상 및 동반하는 다른 치아의 발달 이상에 관하여 고찰하는 것이다. 국소적 요인이 없이 제1대구치 맹출 지연을 보이는 건강한 어린이 40명의 파노라마방사선 사진 분석을 시행하였다. 2명의 평가자가 Nolla 방법을 이용하여 해당 치아의 발육지연 여부, 해당 분악의 제2대구치 발육 이상 여부 및 제3대구치를 제외한 다른 치아의 선천적 결손 여부에 관하여 조사하였다. 제1대구치의 발육지연은 상악에서 호발하였고, 여성에게서 양측성 이환, 남성에게서 편측성 이환이 많이 관찰되었다. 제1대구치의 발육지연이 있는 환아는 유의하게 높은 선천적 결손치의 유병률을 보였으며, 이환된 분악의 제2대구치는 모두 발육 지연 혹은 선천적 결손의 이상을 보였다. 본 연구결과 제1대구치의 발육지연은 다른 치아의 선천적 결손과 밀접한 연관이 있는 것으로 나타났다. Delayed eruption of the first molar, without a generalized or localized cause, is usually associated with delayed development of the affected tooth. The aim of this study was to investigate the clinical features of the first permanent molar showing delayed development and eruption, and its association with developmental anomalies of other teeth. Panoramic radiographs of 40 healthy children showing delayed development and eruption of first permanent molars were analyzed. The clinical features of affected first molars and developmental anomalies of other teeth (except third molars) were evaluated. Delayed first molars were more frequent in the maxilla. The incidence of bilateral delayed development of first molars was greater than that of unilateral cases in female patients. In contrast, male patients showed unilateral delayed development of the first molar more frequently. A higher incidence of congenitally missing teeth was observed in patients with delayed first molar. In each case, delayed development or congenital absence was observed in the second molar adjacent to the delayed first molar. Overall, delayed first molar seems to be associated with congenital absence of additional teeth. Understanding the developmental mechanisms of this phenomenon requires further studies.

유기인제의 수소 환원

이명연,Lee Myung Yun 대한화학회 1969 대한화학회지 Vol.13 No.2

Organophosphorous compounds can be reduced by zinc metal in acidic solution after alkaline hydrolysis. Although phosphates and phosphonates did not evolve any gas, dithioates did evolve hydrogen sulfide and phosphine, thionates and thiolates did evolve only hydrogen sulfide. The evolved gases were qualitatively detected by means of lead acetate and silver nitrate or mercuric bromide papers and determined by spectrophotometrically. The reduction mechanism and analytical method of dithioates were proposed.

Epidermal Growth Factor의 투여에 의한 마우스의 면역반응 변조

이명연,신형식,Lee, Myung-Yeon,Shin, Hying-Shik 대한치주과학회 1989 Journal of Periodontal & Implant Science Vol.19 No.2

취조직내 Protein Methylases 활성도에 관한 연구

이명연,홍성렬,이춘우 대한약학회 1983 약학회지 Vol.27 No.4

Among the many protein modifications methylation is being investigated actively with regard to bacterial chemotaxis, gene regulation, muscle contraction, cytochrome c methylation, and the synthesis of the acyl transporter, carnitine. In this study the activities of protein methylase I, II, and III in pancreatic tissues of rat, mouse, and guinea pig were examined. Furthermore, the effect of cholinergic agents on the activity of protein methylases in pancreatic fragment of guinea pig was also examined in order to test the relationship between protein methylation and pancreatic secretion. The results are as follows. 1) The activities of protein methylases were generally high in pancreatic tissues of guinea pig and mouse but low in the tissue of rat. 2) The cholinergic stimulants, acetylcholine and carbachol at a concentration of $10^{-5}M$ decreased the activities of protein methylase I, II, and III compared with unstimulated control. 3) The inhibitory effect of the cholinergic stimulant on the activities of protein methylases was not blocked by atropine at a concentration of $10^{-5}M$.

O,O-dimethyl-S-(phthalimido) Methylphosphoro-dithioate의 알칼리 가수분해와 수소환원에 관한 연구

이명연 대한약학회 1972 약학회지 Vol.16 No.1

O,O-Dimethyl-S-(phthalimido)methylphosphorodithioate (PMP) is changed into phosphine, phosphate, and phosphorothioate, when it is treated with metallic zinc in acidic medium after alkaline hydrolysis. The amount of phosphine evolved is about five times as much in sulfuric acid medium as it is in hydrochloric acid. When one micro mole of hydrolyzed PMP is treated with 8 grams of metallic zinc and 30 ml of 10 N-sulfuric acid, it is changed into 0.42 micro moles of phosphine, 0.14 micro moles of phosphorothioate, and 0.44 micro moles of phosphate.

Facile Sythesis Melamine-Terephthalaldehyde Polymer (MTP) for CO₂ Adsorption

이명연,류지형,소재일,심상은 한국고분자학회 2018 한국고분자학회 학술대회 연구논문 초록집 Vol.43 No.2

Molybdenum blue에 의한 인산과 비산의 분리 정량

이명연,안창식 成均館大學校 1971 論文集 Vol.16 No.-

In acidic solution of sulfuric acid, phosphate and arsenate in a sample have been determined spectrophotometrically as molybdenum blue after the reduction with hydrazine sulfate. To determine the phosphate and arsenate separately, arsenate has been reduced with potassium iodide and sodium sulfite, then only phosphate has determined.

Molybdenum Blue에 의한 Dimethyl Polysiloxane의 정량

이명연,양미영 成均館大學校 1976 論文集 Vol.22 No.-

Determination methods of dimethyl polysiloxane had been reported by gravimetry, colorimetry, I.R, U.V, G.L.C etc. This study observed an easier method than those experiments with molybdenum blue color reaction. The sample is decomposed by adding 40㎖ of combined conc. acid (H_2SO_4 : HNO_3=1 : 1) and heating in Kjeldahl flask. Alkalihydroxide sol. is added to the sol. and alter it with sulfuric acid to weak acidify, then adding 3㎖ of 5% ammonium molydate sol. and treat in boiling water bath. After adding 10㎖ of 6N-H_2SO_4, 3㎖ of 0.05% hydrazine sulfate and dist. water in 50㎖ vol. flask, treat in boiling water bath again. The range of determination is about 0.4∼5.6 ㎍/㎖ with regard to sol. of color reation.

Pentoxifylline과 그 製劑의 GLC에 依한 分析

이명연,윤병호 成均館大學校 科學技術硏究所 1987 論文集 Vol.38 No.1

A rapid and specific gas liquid chromatographic assay for the quantitative determination of pentoxifylline and its dosage form was described. GLC was performed on a stainless steel column packed with 1.5% OV-101 on chromosorb G and flame ionization detector. Quantitation was accomplished by peak height or peak area with a disk integrator using cinchocaine HCl as the internal standard. The retention time of pentoxifylline was 2.0 min. and cinchocaine HCl as the internal standard was 3.7 min. The mean percent recovery for pentoxifylline was 100.05% and relative standard deviation was 1.72%. The calibration curve was linear in a range of 1.25∼7.5㎍(r=0.9992). This method was simple, precise, accurate and rapid.

血漿內 Clobazam 과 Desmethylclobazam 의 HPLC에 의한 分析硏究

이명연,윤병호 成均館大學校 科學技術硏究所 1987 論文集 Vol.38 No.1

A simple and rapid method for the determination of clobazam(CLB), 1.5-benzodiazepine derivative and its major metabolite, desmethylclobazam(DMCLB) both in plasma and dosage form was examined using HPLC. For the clean-up and enrichment of drugs from plasma, liquid-liquid extraction using toluene and solid-liquid extraction using Sep-pak C-18 and XAD-7 as a solid phase were studied. The validity of the analytical procedure was demonstrated by monitoring the changes in the concentration of CLB and DMCLB in plasma samples of rabbits and guinea pigs after the dose of CLB at 2 mg/kg. The results were summarized as follows : 1. CLB and DMCLB could be separated quantitatively both in adsorption and reverse-phase partition mode. RP mode using Lichrosorb RP-8 column, however, gave the highest resolution. 2. When this column was used with acetonitrile/water(50 : 50V/V) as a mobile phase of 1 ml/min. and UV detection at 254 nm, retention times of DMCLB, CLB and DZP were 5.2, 6.65 and 8.2 min, respectively. 3. Among the solvents studied, toluene at pH 9.6 was found to be the optimal solvent for the extraction of CLB and DMCLB from plasma which gave the highest recovery of 98%. 4. In solid-liquid extraction, both Sep-pale C-18 and XAD-7 as a solid phase gave the average recoveries of CLB and DMCLB with above 95% and 96% respectively. The within-day precisions for the CLB and DMCLB determination using XAD-7 were 98.8% and 99.2% respectively with the relative standard deviation of 3.3% both. The day to day precisions were 99.0% and 99.4% with relative standard deviation of 5.3% and 6.0% respectively. 5. The response curves of CLB and DMCLB in plasma ranging from 25 to 200 ng/ml were linear with the correlation coefficients of 0.9997 and 0.9990 respectively. 6. No other commonly used drugs such as analgetics, anticonvulsants and 1.4-henzodiazepines were found to interfere with the analysis of CLB and DMCLB in plasma with the exception for nitrazepam. 7. GC/MS runs were performed for the analysis and identification of CLB and DMCLB in plasma samples of rabbit and guinea pig after the oral dose of CLB. The highest plasma level of CLB was reached at 60min. same both for rabbit and guinea pig. However, the highest level of DMCLB was reached at 8 and 2 hours respectively.