생체분해성 망막압정을 이용한 망막고정에 대한 실험적 연구

김용백,민병무,김창식,박근성,김승영,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

Biodegradable retinal fixation devices obtain mechnical fixation of the retina with desirable chorioretinal scarring and with the potential for local, sustained release of antimetabolites and steroids to inhibit proliferative vitreoretinopathy. We manufactured a biodegradable retinal tack with barb that was designed in order to prevent intrusion from implantation of retinal tacks. This study was carried to evaluate the efficacy for retinal fixation and the capability for sustained release of drugs with a newly designed biodegradable retinal tack Biodegradable retinal tacks were made of polymers of glycolic acids and were designed with barbs in a shape to prevent the disinsertion. Biodegradale retinal tacks are divided into 3 parts, a conical portion that is inserted into the sclera, a cylinder portion that remains in the vitreous, and a neck portion between the pin and the cylinder. The tapered conical end was manufactured to allow easy insertion through the retina and choroid into the sclera. A cylinder portion was manufactured with a tapered angle that fixes firmly into the orifice of 19 gauge spinal needle. A neck portion, 0.4 mm in diameter, was designed to prevent disinsertion from following implantation of retinal tack. The applicator was a 19 gauge spinal needle and its orifice was prepared to 15°angle to accept the tapered cylinder portion of the retinal tack. The retinal tacks, secured in the needles, were passed through the formed vitreous and inserted into the retina, choroid, and sclera and were released by pushing the internal needle, usually within 2-3mm of the medullary ray of the posterior rabbit retina A retinal tack was placed in each of 8 pigmented rabbit eyes. Slit-lamp biomicroscopy, indirect ophthalmoscopy and fundus photography were performed periodically from 1 day to 8 weeks after surgery. Eight eyes were enucleated and studied by light microscopy at 8 weeks. Biomicroscopic evaluation of the animals revealed edemas adjacent to the retinal surfaces immediately after insertion of the biodegradable retinal tacks in all the animals. These edemas disappeared after 1 week. The first noticeable change in the size of retinal tacks was shown after 2weeks. The size of the retinal tacks gradually got smaller, decreasing to about one-half at 4 weeks and about one-third at 8 weeks. All retinal tacks remained in inserted places without any movement for an 8 week period. On light microscopy, epiretinal proliferations were seen to extend into the vitreous cavity. Cellular capsules that lined the inner aspect of the scleral defect caused by tack insertion were found. However the adjacent retina had a normal cytologic appearance and architecture in all specimens. We manufactured a biodegradable retinal tack that is designed to prevent intrusion from implantation of retinal tacks. All biodegradable retinal tacks reduce in size with time, but no retinal tacks extruded from the inserted place. The newly designed biodegradable retinal tack can be used for retinal fixation and may be used as a vehicle for the introduction of pharmacologic agents to prevent the cellular events that promote proliferative vitreoretinopathy.

T 세포활성항원 CTLA-4의 기능에 관한 연구 : T 세포에서 표적세포 살해능과 CTLA-4 발현과의 연관성 Target Cytotoxicity of T Cell Correlates with CTLA-4 Production

노만택,조양자,김용식,최용,조보현,최장원,정용훈 大韓免疫學會 1996 大韓免疫學會誌 Vol.18 No.4

CTLA-4, a T cell activation antigen and a homologue of CD28, was originally identified as a gene by a series of reverse genetic approaches. While CD28 molecule has been characterized well as a stimulator of T-cell function via enhanced lymphokines production and stablilization of those mRNA, most of the functions of CTLA-4 remain unknown. It has been widely accepted that CTLA-4 functions as an immune suppressor which is down-regualting the function of CD28. We previously showed that 34 KD form of this antigen mainly expressed CD8+ subset, a cytotoxic or suppressor, of activated peripheral blood lymphocyte. Based on our previous finding this study was conducted to further characterize immunological function of CTLA-4 especially in terms of involvement of this molecule in T-cell effector function mediating target cell cytotoxicity. 4 human T cell clones with different target cytotoxicities were employed in this study. NBL46 (CD4+) and NBL77 (CD8+) were cytotoxic and NBL32 (CD4+) and NBL58 (CD 8+) were non-cytotoxic to target LBF cell in target cell chromium release assay. And in Western blot assay 34 kD antigen was detected in NBL46 (CD4+) and NBL77 (CD8+) clones but not in NBL32 (CD4+) and NBL58 (CD8+) clones. It was summarized that expression of the CTLA-4 antigen was associated with cytotoxicity but not with subset phenotypes of T cells. In conclusion CD8+ T subset of PHA-stimulated PBL was major and only CTLA-4 producer and this molecule was induced during mid to late stage of T cell activation. The cytotoxicity of T cell clones to its target cell was directly correlated with its CTLA-4 production and vice versa. And it was highly suggested that primary function of CTLA-4 may involved in T cell effector function which mediates target cell killing.

위암환자의 복강내에 투여한 Mitomycin C-Carbon Particle의 Mitomycin 용출에 관한 연구

노승무,조영훈,정경수,오정연,김진향,양준묵,강대영,송규상,조준식,최선웅,이진호,민병무,김용백,김창식,박근성,인현빈,정현용,김학용 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

Locoregional recurrence is the most common type of recurrence in surgical operation of gastric adenocarcinoma, and peritoneal dissemination is one of the most difficult problems in advanced gastric adenocarcinoma treatment. Because the peritoneal cavity is the most common site of the first recurrence after gastric cancer resection, intraperitoneal chemotherpy seems a logical choice for cancer chemotherapy. The Mitomycin C(MMC) adsorbed by the activated charcoal particles(CH) is relatively released when the drug concentration surrounding the carbon particles becomes low in the peritoneum of the peritoneal cavity. For the intraperitoneal chemotherapy on the advanced gastric adenocarcnoma, mitomycin C adsorbed on activated carbon particles was administered in the peritoneal cavity just before abdominal wall closure. The closed drainage tubes were inserted in the peritoneal cavity and clamped for tuo hours after completion of operation. MMC concentrations were serially measured in peritoneal fluid, plasma and urine at 2hour, 48 hour, 72 hour and 168 hour following its administration in order to study the efficacy of the MMC-CH as a drug delivery system. There were minimal toxicities in born marrow, liver, and gastrointestinal system after intraperitoneal MMC-CH administration. The data of this study suggested that MMC-CH may have a somewhat more beneficial effect than surgery alone when administered in optimal dose and schedules, but the MMC concentration of the peritoneal fluid was not sufficient to eradicate remnant cancer cells, and effective duration of maintenance was only below 24 hours in the peritoneal fluid and plasma.

생체분해성 고분자를 이용한 사시수술용 제형개발 및 효용성에 대한 연구

민병무,김용백,김승영,김창식,박근성,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

A new device, muscle clamping system was developed to facilitate exact quatifying technique A strabismus surgery, and reduce the risk of complications. The device is composed of a lower fixing body with three jaws and an upper supporting body. They are used to clip an extraocular muscle and fix it to the sclera with a single bite. Superior rectus recession on 16 rabbit eyes were performed with this new device. Conjunctival injection, muscle adhesion strength, and light microscopic findings were examined at 1, 2, 4 and 8 weeks postoperatively. The Conjunctival injection were minimal, adhesion power ranged from 420 to 600 gram gravity, which is sufficient in withstand the normal pull of human extraocular muscle. In microscopic exam, some Inflammatory cells and fibrosis were found. The new device was technically easy, fast, and accurate, so it may be useful in stabismus surgery.

표면 조도의 변화에 따른 마찰 및 마멸 특성

조용주,이상욱,구영필,서만식 釜山大學校生産技術硏究所 1999 生産技術硏究所論文集 Vol.56 No.-

마찰과 미끄럼 마멸에서 표면 거칠기의 특성에 대한 효과는 실험적으로 볼-디스크 마멸 시험기를 가지고 연구되어졌다. 실험은 서로 다른 하중, 미끄럼 속도, 그리고 윤활유 점도 조건하에서 산술평균값, skewness, kutosis를 변화시켜 수행되었다. 음의 값을 가지는 더 낮은 skewness 또는 더 높은 kutosis의 표면조도를 가진 같은 상술평균 값에 대하여 더 낮은 마찰을 가지는 경향이 있다. The effect of characteristic of surface roughness on friction and sliding wear was studied experimentally with ball-on-disk type wear tester. The test was conducted with specimens those have varying arithmetic mean value, skewness and durtosis under the condition of different load, sliding speed and lubricant viscosity. The surface of the lower skewness in negative value or the higher kurtosis tends to have low friction for the same arithmetic mean value.

순화슬러지와 생슬러지로 본 질산염제거특성

조순자,정용주,이나은,이정은,손형식,이상준 부산대학교 환경문제연구소 2003 環境硏究報 Vol.21 No.-

Using acclimated sludge with inorganic nitrogen medium for three months and non-acclimated sludge, raw sludge, under aerobic condition we investigated characteristics biological nitrogen removal. As results, e acclimated sludge under aerobic condition accomplished nitrification efficiently. But the samples from the reactor operated raw sludge had higher ammonium concentration rather than the concentration which was loaded by the medium. This means when we are trying to reorganize existing facilities, we should take high initial ammonium concentration into account.

Computer Simulation을 이용한 활성슬러지 공정의 해석

조용진,이호식 충주대 산업과학기술연구소 1995 産業科學論文集 Vol.3 No.-

Mathematical models have been developed to understand and optimize the activated sludge process. In this study, IAWPRC model No. 1 and McKinney model were used to evaluate to activated sludge process. The biokinetic and stoichiometric coefficients were calibrated and verified and then compared of IAWPRC model No. 1 with McKinney model. In addition, biological nutrient removal process - Anaerobic/Oxic(A/O), Anaerobic/Anoxic/Oxic(A2/O), Modified University of Cape Town(MUCT) - was simulated using of ENBIR program based on IAWPRC model No. 1. The comparison of IAWPRC model Ne.1 and McKinney model showed that two models almost similar in concept. Also the result of computer simulation - using of biokinetic and stoichiometric coefficients and influent wastewater characteristics - represented that the measured value was closed to those simulate result. As that result, suggested method by this study can be applied to activated sludge process analysis.

정량적관상동맥조영술의 정확도 및 재현도

조용근,황진용,박헌식,채성철,전재은,박의현 慶北大學校 醫科大學 1996 慶北醫大誌 Vol.37 No.4

목적 : 정량적관상동맥조영술이 최근 널리 보급되고 있지만 국내외를 막론하고 이의 정확도 및 재현도에 관한 연구가 불충분하여 본 연구를 하였다. 대상 및 방법 : 110명의 환자에서 미국 General Electric사의 Advantx L/C/LP 디지탈혈관찰영기와 미국 USCI사의 좌관상동맥용 Judkins형의 Pro-Flo XT^(TM) 6F 도자를 이용하여 좌관상동맥조영술을 같은 각도에서 3회 실시하고 도자의 외경을 일본 Mitutoyo사의 정밀도 0.01㎜의 micrometer로 측정한 후 측정된 도자의 실제 직경과 정량적관상동맥조영술로 측정된 관상동맥의 직경을 비교하였다. 결 과 : USCI® Pro-Flo XT^(TM) 6F 좌관상동맥용 도자의 실제 외경은 1.91±0.03㎜이었고 정량적관상동맥조영술로 측정 한 도자의 외경은 1.94±0.11㎜이었다. 도자를 5.7F로 calibration했을 매 도자의 외경은 1.87±0.12㎜이었다. 세번 다 다른 화상에서 측정한 경우 근위부관상동맥 직경의 차이는 0.02±0.12㎜이었고 같은 화상에서 3회 측정하였던 경우에는 0.11±0.01㎜이었다. 결론 : 정량적관상동맥조영술의 정확도 및 재현도는 사용에 적합한 정도이나 적지 않은 문제점에 대한 보완이 필요하다고 생각된다. During quantitaive coronary angiography(QCA), contrast filled catheter is usually used as a scaling device. However the real diamerer of catheter is almost always smaller than the listed diameter. We measured the real diameter of catheters with precision micrometer(Mitutoyo® Japan). After caliberating the catheter as listed French size and diameter, we did QCA at the same tube position of the diameters of catheter and proximal left coronary artery. All measurements were done 3 times consecutively. The mean real diameter of USCI® Pro-Flo XT^(TM) 6 F left Judkin catheter was 1.91±0.03 ㎜. The mean QCA diamter of the same catheter was 1.94±0.11 ㎜. When we calibrated catheter as 1.91 ㎜. the mean QCA diameter was 1.87±0.12 ㎜. The mean differences of the diameters of the proximal left coronary artery were 0.20±0.12 ㎜ when the measurements were done in three different frames. When the measurements were done in the same frmae, the mean difference decreased to 0.11±0.01 ㎜. We conclude that the precision and reproducibility of QCA are within reasonable range, but more refimement is needed.

돈사폐수의 영양염류 제거를 위한 기질특성 연구

조용진,이호식 충주대 산업과학기술연구소 1996 産業科學論文集 Vol.4 No.-

This study was performed to investigate of substrate characteristic of COD for piggery wastewater of nutrient(nitrogen and phosphorus) removal. The influent COD of the piggery wastewater is divided into readily biodegradable COD(Ss) , slowly biodegradable COD (Xs), inert soluble COD(SI) and inert suspended COD(XI). Percents of each form were resulted as 36.6%, 29.7%, 7.7%, and 27%, respectively. The ammonia nitrogen was utilized via stripping, nitrification, autotrophic cell synthesis, heterotrophic cell synthesis, and aerobic denitrification. The removal percents by each step were resulted as 12.9%, 43.1%, 15%, 3.2% and 25.7%, respectively.

세균성 전립선염의 실험동물 모델

이용석,신명식,조용현 大韓泌尿器科學會 2001 Korean Journal of Urology Vol.42 No.6