계수공정영상의 비선형 대조도 증강효과에 관한 연구

이건일,진연화,Lee Keon-Il,Jin Yeun-Hwa 대한영상치의학회 1997 Imaging Science in Dentistry Vol.27 No.2

This study was performed to demonstrate the effect of linear or nonlinear contrast enhancement on subtraction images. Three different textures were radiograped on dental film. The first radiograph was taken without the presence of an object. the second, which showed trabucular bone, was taken of the molar area of a human. the third radiograph was taken of the coronal part of molars. Each film was digitized into a 1312 x 1024 pixel x 8 bit depth matrix by means of a Nikon 35 mm film scanner(LS-3510AF, Japan) with fixed gain and internal dark current correction to maintain constant illumination. The scanner was interfaced to a Macintosh Le ill computer(Apple Computer, Charlotte, N.C) This resulted in three pairs of images, including different textures-plain, bone and enamel. Digital regular, linearly and nonlinearly enhanced subtraction was performed. Computer software was ,used to simulate lesions in the shape of a 2D-Gaussian curve on each of a pair of images. The each subtraction images were presented in a random sequence to two groups of 10 observers(students and dentists). ROC analysis was used to compare observer performance. The following results were obtained ; 1. All of LCE subtraction, equalized subtraction and regular subtraction images of plain texture were diagnosed the best by far. 2. The data revealed a siginificant LCE effect in both the student group and the expert group. 3. Clinical expertise was a helphul factor for the observers in this study.

수종과 암세포주와 섬유모세포주에서 taxol과 전리방사선이 세포독성과 prostaglandin생성에 미치는 영향

이건일,유동수,Lee Keon-Il,You Dong-Soo 대한영상치의학회 1998 Imaging Science in Dentistry Vol.28 No.1

The author evaluated the effects of taxol, a microtubular inhibitor, as a possible radiation sensitizer and the production of prostaglandins on three human cancer cell lines(KB, RPMI-2650 and SW-13) and one murine cell line(L929). Each cell line was divided into four groups (control, taxol only, radiation only and combination of taxol and radiation). The treatment consisted of a single irradiation of 10Gy and graded doses (5, 50, 100, 200, 300, 500 nM) of taxol for a 24-h period. The cytotoxicity of taxol alone was measured at 1 day after(1-day group) and 4 days after(4-day group) the treatment. The survival ratio of cell was analyzed by MTT (3-(4,5-dimethylthiazol-2-yl) -2,5-dimethyl tetrazolium bromide) test. Prostaglandins(PGE2 and PGI2) were measured in the culture medium by a radioimmunoassay. The results obtained were as follows. 1. There was a significantly increased cytotoxicity of KB cells in 4-day group than those in I-day group. There was a high correlation between doses of taxol and cell viability in both groups(l-day group R=0.82741, 4-day group R=0.84655). 2. There was a significantly increased cytotoxicity of RPMI -2650 cells treated with high concentration of taxol in 4-day group than those in I-day group. Also there was a high correlation between doses of taxol and cell viability in 4-day group(R=0.93917). 3. There was a significantly increased cytotoxicity of SW-13 cells treated with high concentration of taxol in 4-day group than those in 1-day group. However no high correlation was observed between doses of taxol and cell viability in both groups(1-day group R=0.46362, 4-day group R=0.65425). 4. There was a significantly increased cytotoxicity of L929 cells treated with low concentration of taxol in 4-day group than those in 1-day group. At the same time, there was a low correlation between doses of taxol and cell viability in both groups(1-day group R=0.34237, 4-day group R=0.23381). 5. In I-day group of L929 cells, higher cytotoxicities were observed in the groups treated with 500 nM taxol than given 10 Gy radiation alone. L929 cells in I-day group alone showed a radiosensitizing effect by taxol.. 6. In addition to L929 cells, all cancer cells treated with a combination of taxol and radiation in 4-day group appeared to have some fragmented nuclei and to float on the medium. In addition, L929 cells appeared to be more confluent. 7. The level of PGE2 production was the highest in the contol KB cells. This appeared to increase in every experimental group of all three cancer cells except L929 cells. There was a significantly increased production of PGE2 in SW -13 cells treated with a combination taxol and radiation compared to the other experimental groups. 8. The level of PGE2 production in the control group of RPMI-Z650 cells was the highest. This appeared to increase in every experimental group of all cells except in SW-13 cells. This also increased significantly in RPMI-2650 cells treated with a combination of taxol and radiation compared to the other experimental groups.

Fractal dimension과 2차원 푸리에변환을 이용한 수질골의 특성화에 관한 실험적 연구

이건일,Lee Keon Il 대한영상치의학회 1998 Imaging Science in Dentistry Vol.28 No.2

The purpose of this study was to investigate whether a radiographic estimate of osseous fractal dimension and power spectrum of 2D discrete Fourier transform is useful in the characterization of structural changes in bone. Ten specimens of bone were decalcified in fresh 50 ml solutions of 0.1 N hydrochloric acid solution at cummulative timed periods of 0 and 90 minutes. and radiographed from 0 degree projection angle controlled by intraoral parelleling device. I performed one-dimensional variance. fractal analysis of bony profiles and 2D discrete Fourier transform. The results of this study indicate that variance and fractal dimension of scan line pixel intensities decreased significantly in decalcified groups but Fourier spectral analysis didn't discriminate well between control and decalcified specimens.

히스토그램을 이용한 치주질환진단에 관한 연구

이건일(Keon Il Lee),진연화(Yeon Hwa Jin) 대한치과의사협회 1999 대한치과의사협회지 Vol.37 No.1

βTC-6 세포에서 Floxetine과 Mirtazapine이 인슐린 분비에 미치는 영향

전성균(Sung-Kuyn Jun),박기창(Ki-Chang Park),장형민(Hyung-Min Chang),이건일(Keon-Il Lee),공인덕(In-Deok Kong) 대한생물치료정신의학회 2004 생물치료정신의학 Vol.10 No.2

Objective : It is well known that antidepressants improve glycemic control and prevent relapse of depression in diabetics. However, TCA antidepressants directly interfere with blood glucose levels in some recent reports, and the effects of SSRI antidepressants on blood glucose are controversial. This study aimed to explore the effects of fluoxetine and mirtazapine on insulin secretion. Methods : This study investigated the effect of fluoxetine and mirtazapine on insulin secretion in βTC-6 cells-mouse pancreatic β cell line. Fluoxetine is a prototype of SSRI, mirtazapine is a NaSSA, both of them are widely prescribed. After static incubation during 2 hours, insulin secretion was measured by radioimmunoassay. Results : 1) Glucose increased insulin secretion in a concentration-dependent manner with EC?? 2.7±0.3mM. 2) As the number of cell increased, the amount of insulin secretion was significantly increased. 3) Glibenclamide, K<SUB>ATP</SUB>-channel blocker, markedly increased insulin release. 4) Fluoxetine and mirtazapine inhibited insulin secretion at low(1μM) and high(10μM) concentration. 5) The inhibitory effects of fluoxetine(10μM) were significantly greater than those of mirtazapine(10μM). 6) These inhibitory effects of fluoxetine and mirtazapine on insulin secretion were significantly greater in high glucose level than in low glucose level. Conclusion : Taken together, fluoxetine and mirtazapine might inhibit insulin secretion directly in βTC-6 Cells. 목적 : 우울증이 동반된 당뇨병환자에게 항우울제를 투여하면 우울증상의 재발을 막는 것은 물론이고 혈장조절에도 도움이 된다고 알려져 있다. 그러나, 최근 연구들은 TCA계 항우울제가 혈장을 악화시킨다고 하고, SSPI계 약물들에 대해서는 연구자마다 다른 결과를 보고하고 있다. 본 연구는 SSPI계 대표적 약물인 fluoxetine과, 고혈당증을 유발한 것으로 최근 국내에서 보고된 mirtazapine이 췌장 β세포의 인슐린 분비에 어떠한 영향을 미치는 지를 알아보고자 하였다. 방법 : 마우스의 췌장 β 세포주인 βTC-6를 대상으로 fluoxetine과 mirtazapine을 투여하여 인슐린 분비에 미치는 영향을 관찰하였다. βTC-6 세포를 2시간의 정적 배양 후 방사면역법을 이용하여 인슐린 분비를 측정하였다. 결과 : 1) 인슐린 분비는 포도당에 농도의존적으로 증가하였고, EC??는 2.7±0.3mM이었다. 2) 인슐린 분비는 세포 수에도 의존적으로 증가하였다. 3) KATP-channel 억제적인 glibenclamide를 처치한 군과 대조군을 비교하였을 때, gibenclamide 군의 인슐린 분비가 유의하게 높았다. 4) fluoxetine은 저농도(1μM)와 고농도 (10μM)에서 인슐린 분비를 유의하게 억제하였으며 mirtazapine도 저농도와 고농도에서 인슐린 분비를 억제하였다. 5) 같은 농도의 포도당에서 고농도 fluoxetine의 인슐린 억제효과가 고농도 mirtazapine의 억제효과보다 유의하게 높았다. 6) 고농도의 fluoxetine에서, 그리고 고농도와 저농도의 mirtazapine 모두에서, 고포도당 농도(10mM)일 때가 저포도당 농도(2.5mM)일 때 보다 인슐린에 대한 억제효과가 유의하게 높았다. 결론 : 본 실험결과로 미루어, fluoxetine과 mirtazapine은 βTC-6 세포에 직접적으로 작용하여 인슐린 분비를 억제시키는 것으로 보인다.

치과용 아크릴릭 레진의 방사선 불투과도에 관한 연구 : 황산바륨과 요오드 화합물 첨가

이건일,이용근,정성우 大韓口腔顎顔面 放射線學會 1996 Imaging Science in Dentistry Vol.26 No.2

Aspirating or swallowing foreign bodies is a common occurrence. If they are wholly or partly radiopaque, their localization in and progress through the gastrointestinal tract can be more effective. Of the dental origin foreign materials swallowed, the most common things are fragments of anterior maxillary partial denture. But the radiopacity of denture base resins is not sufficient to determine the location of the objects. The purpose of this study was to develop a radiopaque dental acrylic resin, which has clinically detectible radiopacity with minimal change of mechanical properties and color. The radiopacity, color change(CIE △E)and microhardness of acrylic resins were determined after mixing barium sulfate of iodide compound. Thermocycling course was conducted to determine the change of characteristic of resins after using for a long time in the mouth. Five or ten percent of barium sulfate to total weight of cured material was mixed with heat curing dental acrylic resin or chemically curing orthodontic resin. In the case of iodide compound, the mixing ratio was two or three percent. After mixing the high radiopaque materials. resin was cured to 20×20×2 mm plate, polished with #600 sand paper and finally polished with Microcloth(Buehler). The specimens were thermocycled in 5 and 55 ℃ distilled water for 2,000 times, and the measurement of radiopacity, color and Vickers hardness was repeated every 500 times thermocycling. The radiopacity of specimens on the X-ray films was measured with densitometer(X-rite). The color change was determined with differential colorimeter (Model TC-6FX, Tokyo Denshoku), and the Vickers hardness number was measured with microhardness tester(Mitsuzawa). The following results were obtained: 1. All the three variables, the kinds of acrylic resins, the mixing or the kinds of high radiopaque materials and thermocycling, had combined effect on the radiopacity of the dental acrylic resins(p<0.01). 2. The two variables, the mixing or the kinds of high radiopaque materials and thermocycling, influenced on the radiopacity of the dental acrylic resins(P<0.01). But the kinds of acrylic resins did not influence on the color change of mixed dental acrylic resins(p>0.05). 3. Each of the three variables, the kinds of acrylic resins, the mixing or the kinds of high radiopaque materials and thermocycling, influenced on the radiopacity of dental acrylic resins (P<0.01). 4. The high radiopaque materials used in this study did not yield clinically usable radiopacity, and the color change was great after mixing those materials.

수동형 Stainless Steel, Nickel-Titanium 및 엔진 구동형 Nickel-Titanium File의 근관형성 능력에 관한 비교 연구

이황,임미경,이건일,이용근 大韓齒科保存學會 1998 Restorative Dentistry & Endodontics Vol.23 No.1

The aim of this study was to determine the shaping ability of stainless-steel K file (S-S K file), nickel-titanium K file (Ni-Ti K file) and engine driven nickel-titanium file (Quantec file) in resin simulated root canal. Computed tomography was used to evaluate the change of the root canal morphology. Thirty nine resin simulated root canal were divided into four groups (A:12, B:12, C:12, D:3). Resin simulated canals were scanned by computed tomography before instrumentation (1st C-T scan). Canals were instrumented using step back preparation technique with S-S K file in group A and Ni-Ti K file in group B. Group C was prepared with engine driven Ni-Ti file. Group D was uninstrumented to compare the 1st C-T scan images with 2nd C-T scan images of root canal. Instrumented canals were again scanned using computed tomography (2nd C-T scan), and reformated images of the uninstrumented canals were compared with images of the instrumented canals. In the sections of 2mm and 6mm from the apex, Quantec file caused significantly less canal transportation than S-S K file and Ni-Ti K file (p<0.05). Quantec file produced more centered than S-S- K file and Ni-Ti K file in the sections of 2mm and 4mm from the apex (p<0.05). There was no significant difference in the removed volume of canals among the each groups (p>0.05). However the removed canal volume from the apex to 5mm were significantly higher than them from 5mm to 1mm (p<0.05) in each groups. Under the conditions of this study, preparation with Quantec file was more effective and produce more appropriate canal shapes than S-S K file and Ni-Ti K file.

치근단낭과 육아종의 디지털방사선학적 비교연구

이건일,진연화 大韓口腔顎顔面 放射線學會 1999 Imaging Science in Dentistry Vol.29 No.1

The purpose of this study was to investigate whether a radiometric analysis of radicular cysts and periapical granulomas is useful in the differential diagnosis. In this experiment, twenty-nine periapical radiographs of the radicular cyst and those periapical granuloma were used. The periapical radiography was taken by intraoral paralleling device. The X-ray film was digitized and digitally filtered to reduce film-grain noise. We estimated density difference of the inner/outer area, roundness or circularity, bone profile or scan line of the margin and cumulative percentage frequency curve of radicular cyst & periapical granuloma. The obtained results were as follows; 1. The differences in density between ROIs of inner and outer area of radicular cysts were smaller than those of periapical granulomas. 2. The equivalent circular diameter was over 6.3mm, there was significant difference between periapical cyst and periapical granuloma. 3. In differential diagnosis of radicular cyst and periapical granuloma using bone profile, sensitivity, specificity and accuracy were considerable high(0.83, 0.86, 0.86) respectively. 4. Cumulative percentage frequency curve of the radicular cyst was closer to the pseudo-pixel value of 50 than average curve, whereas periapical granuloma was closer to that of 0. Hence we conclude that digital radiometric features might be useful in the differential diagnosis between radicular cyst and periapical granuloma.(J Korean Oral Maxillofac Radiol 1999:29:239-252)

수복재의 적정 방사선 불투과도에 관한 연구

이용근,임미경,문상은,이건일 大韓齒科器材學會 1995 대한치과재료학회지 Vol.22 No.2

The purpose of this study was to investigate the level of the radiopacity of composite resins, glass ionomers for filling and cements, and to determine the optimum level of radiopacity that is the most appropriate for the radiologic diagnosis of secondary caries. The experiments were performed in two parts. In the first part, the radiopacities of specimens of seven composite resins, two glass ionomers and four cements were measured by densitometer and those of the combined specimens were also measured. In the second part, caries was simulated by grooves of the depth of 0.5, 1.0, 1.5, 2.0mm in aluminium blocks of 4mm. thick. Specimens of 2, 4, 6mm. thick were mounted on the caries simulation block, and the differences of radiopacities between caries portion and noncaries portion were analyzed. The following results were obtained : 1. The radiopacity of dental materials at 2mm thickness displayed a wide range of radiopacity, from 1.14 to 11.70mm. aluminium equivalents. 2. Most of the cements showed significantly higher radiopacity values of 8.78 to 11.70mm. aluminium equivalents, and those of ZPC were higher than any other materials used in this study. 3. Filling materials with radiopacity similar to enamel showed a tendency to have a sufficient degree of contrast facilitate the detection of underlying recurrent caries.

고선량 방사선 조사후 치아수복재의 특성변화

이용근,이건일,이성재,박수아,허정무 원광대학교 생체재료·매식연구소 1996 원광생체재료·매식 Vol.5 No.2

To investigate the effect of high dose irradiation on the Vickers hardness number(VHN), color change and wear rate of dental filling materials, esthetic filling material specimens were studied. Six kinds of composite resins and two kinds of glass ionomers(GI) were used. One(CLF) was chemically cured composite resin, and five(HCX, HPL, PHB, POF, PRT and RZI) were light cured composite resins. One(FJT) of GI was chemically cured GI and one(FLC) was light cured GI. The filling material specimens were made according to the manufacture's instructions and were finally polished with Microcloth(Buehler). Half of the specimens were irradiated with 100 Gy radiation using a linear accelerator(Mitsubishi, 6 MV). VHN and CIELAB color were measured before and after irradiation, and wear test were performed for nonirradiated specimens by brushing with toothpaste, From the experiment , the following results were obtained. 1. The CIELAB color difference was significantly different depending on the material(p<0.01), and FLC showed the highest color difference (CIELAB ΔE) of 9.452 and CLF showed the lowest value of 3.642. 2. The VHNs of nonirradiated specimens were 12.22∼73.58 and those of irradiated specimens were 25.53∼84.53. The VHNs of irradiated specimens were significantly higher than those of nonirradiated specimens(p<0.05) except RZI, FJT and FLC. 3. The wear rate of irradiated specimens of RZI, FLC were significantly lower than those of nonirradiated specimens(p<0.05). 4. The color difference after brushing of irradiated specimens were higher than those of nonirradiated specimens except CLF.