축하중과 첨가질량이 작용하는 적층복합판의 진동해석

이봉학,김경진,원치문,성기태 江原大學校 産業技術硏究所 1995 産業技術硏究 Vol.15 No.-

A method of calculating the natural frequency corresponding to the first mode of vibration of beams and tower structures, with irregular cross-sections and with arbitrary boundary conditions was developed and reported by D. H. Kim in 1974. IN this paper, hte result of application of this method to the laminated plates with axial forces and with attached point mass/masses is presented. Both N? and N? forces are considered. The solution for the laminated plates with arbitrary boundary conditions and irregular section can be obtained by simply obtaining the deflection influence coefficients by any method. The effect of neglecting the mass of the plates on the natural frequency, as the ratio of the point mass/masses to the plate mass increases, is thoroughly studied. The influence of N? and N? is also carefully investigated.

위암 환자의 복강내 투여를 위한 Activated Charcoal-Alginate Bead 제형으로부터 Mitomycin C의 용출 거동

이진호,최선웅,서중기,김동민,정경수,오정연,김진향,노승무,민병무,김용백,김창식,박근성,강대영,송규상,양준묵,조준식,정현용,김학용,인현빈 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 chemotherapy seems a logical choice for cancer chemotherapy. In this study, Mitomycin C (MMC)-activated charcoal (CH)-alginate (ALG) beads were prepared by the mixtures of CH particles adsorbed with MMC as an anti-cancer drug and aqueous alginate solution. The alginate is recognized as biodegradable, nontoxic, and biocompatible. The release of MMC from the beads in 0.1 M Tris buffer was stable and continuous until about 1 week. The MMC-CH-ALG beads can be applied in the peritoneal cavity for intraperitoneal chemotherapy since they provide a good adhesiveness on the tissue and controlled release pattern of the drugs.

주야교대작업이 근로자의 심혈관계 질환의 위험인자에 미치는 영향

신재학,이중정,이경수,사공준,김창윤,정종학 大韓産業醫學會 1995 대한직업환경의학회지 Vol.7 No.1

지속적인 주야간 교대작업이 심혈관계 질환의 위험요인에 미치는 영향을 평가하고, 심혈관계 질환의 위험요인들 중 교대작업에 의해 민감하게 영향을 받는 요인들을 조사하고, 교대작업에 참여한 기간과 위험요인들과의 관계를 평가하기 위하여 울산시에 있는 모 자동차공장 생산직 근로자를 대상으로 1993년 4월 20일부터 2개월간에 걸쳐 단면조사를 시행하였다. 교대작업은 하루 2교대로 이루어지며 야간작업조와 주간작업조는 1주일 주기로 순환되었다. 근무기간 1년이상 80%이상을 교대작업에 참여했던 근로자 420명을 교대작업군으로, 교대작업에 참여한 경험이 전혀 없는 생산직 근로자 88명을 대조군으로 하여 연령, 성별, 최종 학력, 현 산업장에서의 근속기간, 입사전 경력, 현재 작업부서, 작업내용 및 직급을 자기기입식 설문지를 통하여 조사하였다. 교대작업에 관해서는 조사당시의 교대작업에 참여여부, 교대작업의 주기와 규칙성 여부, 입사후 지금까지 교대작업에 참여한 기간을 조사하였다. 심혈관계 질환의 위험요인들로서 혈압, 콜레스테롤치, 중성지방, apolipoprotein A-1과 B 등을 측정하였다. 위험요인들의 단순비교에 있어서는 수축기혈압은 교대작업군과 대조군이 각각 122.4±11.9mmHg, 120.0±11.4mmHg로 교대작업군에서 다소 높았고 이완기혈압도 각각 76.5±9.3mmHg, 75.9±9.1mmHg로서 교대작업군에서 다소 높았으나 유의한 차이는 없었다. 콜레스테롤치와 중성지방도 교대작업군에서 다소 높았으나 통계적으로 유의하지 않았다. Apolipoprotein B는 교대작업자가 101.8±19.9mg/dl로서 대조군의 94.2±26.5mg/dl에 비해 다소 높게 나타났으며 통계적으로도 경계역 유의성을 보였으나(p=0.057), apolipoprotein A-1은 apolipoprotein B에 비해 개인적인 변이가 크고 두 군간의 차이를 인정할 수 없었다. Apolipoprotein B와 apolipoprotein A-1의 비는 교대작업군이 0.73±0.20으로 대조군에 비해 높게 나타났다(p<0.05). 비체중은 두 군 모두 약 22로서 유의한 차이를 보이지 않았으나, 1주일 동안 규칙적인 운동을 하는 횟수는 대조군이 1.27±1.5회에 비해 교대작업자가 0.76±1.1회로서 유의하게 적었다(p<0.01). A형 행동양상을 가지는 비율은 교대작업자에서 58.8%로 주간작업자의 51.1%에 비해 다소 높았으나 통계적으로 유의하지는 않았다. 심혈관계 질환의 주된 위험인자들을 종속변수로 하고 교대작업과 다른 위험인자들을 독립변수로한 다중회귀분석에서는 수축기혈압을 종속변수로 채택하였을 때 가변수 교대작업은 회귀계수 2.668로서 수축기혈압을 증가시키는 것으로 나타났으며 (p=0.059), 비체중도 경계역 유의성을 보였다(p=0.053). 이완기혈압에 대한 다중회귀분석에서는 가변수인 교대작업이 유의한 영향을 미치지 않은 것으로 나타났으며, 비체중이 유의한 변수였다(p<0.01). 콜레스테롤치를 종속변수로 하여 실시한 다중회귀분석의 결과는 연령 및 비체중이 증가할수록 콜레스테롤치가 증가하는 경향을 보였으며 가변수인 교대작업이 콜레스테롤치를 증가시키나 통계적으로 유의하지는 않았다. 중성지방에 대한 다중회귀분석에서는 가변수 교대작업이 중성지방을 증가시키는 것으로 나타났으나 통계적으로 유의하지는 않았다. Apolipoprotein A-1의 경우 가변수 교대작업은 apolipoprotein A-1의 수준을 감소시키는 경향을 보였으나 통계적으로 유의하지는 않았다. 그 밖의 다른 변수들 중 apolipoprotein A-1의 수준에 영향을 미치는 변수는 없었다. Apolipoprotein B를 종속변수로한 다중회귀분석에서는 가변수 교대작업은 apolipoprotein B의 수준을 증가시키는 경향을 보였으나 통계적으로 유의하지는 않았다. Apolipoprotein B와 apolipoprotein A-1의 비를 종속변수로 한 다중회귀분석에서는 가변수 교대작업이 apolipoprotein B/Apo A-1을 증가시키는 변수였으며 통계적으로도 유의하였다(p<0.05). 교대작업군을 교대작업에 참여한 기간이 5년 미만인 군과 5년 이상인 군으로 나누어 비교하였을 때 콜레스테롤치, apolipoprotein B 및 Apo B/Apo A-1가 5년 미만의 교대작업군에 비해 5년 이상인 군이 유의하게 높게 나타났다(p<0.05). 교대작업기간이 위험요인에 미치는 영향을 보기 위해 가변수로 교대작업기간을 독립변수로 투입하여 다중회귀분석을 실시하였다. 콜레스테롤치를 종속변수로 한 다중회귀분석에서는 교대작업의 기간이 길수록 유의하게 증가하는 경향을 보였으며(p<0.05), apolipoprotein B도 교대작업의 기간이 길수록 다소 증가하는 경향을 보였으나 통계적으로 유의하지는 않았다. An investigation of effects of shift work on cardiovascular risk factors has been carried out on workers of a motor company in Ulsan, for 2 months from 20 April to 20 June, 1993. This cross-sectional survey was designed to compare the shift workers(n=420) with day workers(n=88). The study subjects were drawn from workers who were employed in twelve hour shift system. A control group who never experienced shift work was drawn from different sections of the factory. Each worker completed a medical and occupational questionnaire, and cardiovascular risk factors such as blood pressure, total cholesterol, triglyceride, apolipoprotein A-1 and B were measured. In univariate analysis, apolipoprotein B and the ratio of apolipoprotein B to apolipoprotein A-1 increased in shift workers. In multiple regression analysis for the systolic blood pressure, shift work was significant independent variable(p=0.059). In multiple regression analysis for the cholesterol, age and body mass index were significant independent variables(p<0.01), but shift work was not a statistically significant independent variable. In multiple regression analysis for the ratio of apolipoprotein B to apolipoprotein A-1, shift work was significant independent variable(p<0.05). Shift workers who have engaged in shift work more than 5 years have an excess of total cholesterol, apolipoprotein B and ratio of apolipoprotein B to apolipoprotein A-1 than those who have engaged in shift work less than 5 years (p<0.05). In multiple regression analysis for the cholesterol, duration of shift work was a significant independent variable(p=0.012). In multiple regression analysis for the apolipoprotein B and ratio of apolipoprotein B to apolipoprotein A-1, duration of shift work was not a significant independent variable.

Rat의 복강에 삽입한 Fluorouracil-Polyglycolic acid 제형의 Fluorouracil 용출에 관한 연구

노승무,정경수,오정연,김진향,양준묵,강대영,송규상,최정목,최선웅,이진호,조준식,민병무,김용백,김창식,박근성,김승영,김학용,인현빈 忠南大學校 癌共同硏究所 1998 癌共同硏究所 硏究誌 Vol.2 No.1

A common form of relapse in adenocarcinoma of the stomach is intraperitoneal dissemination, in fact, among gastric adenocarcinoma patients who have undergone surgery intended to cure, approximately 50% of the patients develope initial recurrence in the peritoneal cavity regardless of the anatomic site of the primary tumor within the stomach. The efficacy of systemic postoperative chemotherapy to prevent peritoneal recurrence of gastrric adcnocarcinoma is not satisfactory. There is still a great need for improved therapeutic strategies on the disseminated microscopic disease and small miliary nodules remaining on the peritoneal surface or lymphatics after operation. The authers have made fluorouracil-polyglycolic acid composite disks(Fu-PGA disks) with fluorouracil and biodegradable polymer: polyglycolic acid for more effective intraperitoneal chemotherapy. We inserted the Fu-PGA disk(s) in the peritoneal cavity of rat and pharmacokinetic study was performed to measure fluorouracil concentration in the peritoneal fluid, plasma, liver, kidney and heart tissue at 24 hour, 72 hour and 168 hour after insertion of Fu-PGA disk(s). Myelosuppressive action of this composite also was determined following its administration. The data of this study suggested that Fu-PGA composite will be a new device releasing drugs in a controlled manner and having targetability to peritoneum, and this device will be improving the efficacy of intraperitoneal chemotherapy for gastric adenocarcinoma.

Rat의 복강에 삽입한 Filorouracil-Polyglycolic acid제형의 Fluorouracil용출에 관한 연구

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

A common form of relapse in adenocarcinoma of the stomach is intraperitioneal dissemination, in fact, among gastric adenocarcinoma patients who have undergone surgery intended to cure, approximately 50% of the patients develope initial recurrence in the peritoneal cavity regardless of the anatomic site of the primary tumor within the stomach. The efficacy of systemic postoperative chemotherapy to prevent peritoneal recurrence of gastrric adenocarcinoma is not satisfactory. There is still a great need for improved therapeutic strategies on the disseminated microscopic disease and small miliary nodules remaining on the peritoneal surface or lymphatics after operation. The authers have made fluorouracil-polyglycolic acid composite disks(Fu-PGA disks) with fluorouracil and biodegradable polymer: polyglycolic acid for more effective intraperitoneal chemotherapy. We inserted the Fu-PGA disk(s) in the peritoneal cavity of rat and pharmacokinetic study was performed to measure fluorouracil concentration in the peritoneal fluid, plasma, liver, kidney and heart tissue at 24 hour, 72 hour and 168 hour after insertion of Fu-PGA disk(s). Myelosuppressive action of this composite also was determined following its administration. The data of this study suggested that Fu-PGA composite will be a new device releasing drugs in a controlled manner and having targetability to peritoneum, and this device will be improving the efficacy of intraperitoneal chemotherapy for gastric adenocarcinoma.

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.

백서의 복강내에 투여한 Mitomycin-C-Polyglycolic acid 제형이 장기에 미치는 영향에 관한 연구

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

To evaluate the in-vivo effects of mitomycin-C-polyglycolic acid composite(MMC-PGA) the disk: shaped composite were implanted into the peritoneal cavity of the Sprague-Dawley rats. The pathologic changes were examined at various time points up to 12 weeks. Initially the soft tissue around the inserted disks showed capillary congestion at 3 days. Inflammatory infiltrates with foreign body giant cells appeared from the 2nd week and reached peak response at 6-8 weeks. These reaction diminished prominently at 12 weeks. No specific pathologic change was found in the liver, the kidneys, and the heart. The above results suggest that the MMC-PGA composite can serve as a new device for intraperitoneal chemotherapy of various types of cancers.

Rat의 복강내에 투여한 5-fluorouracil-polyglycolic acid 제형이 장기에 미치는 영향에 관한 연구

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

For more effective intraperitoneal chemotherapy, the authers made 5-fluorouracil-polyglycolic acid composite disks(FU-PGA disks) with 5-fluorouracil and polyglycolic acid, a biodegradable polymer. We inserted the FU-PGA disk into the peritoneal cavites of Sprague-Dawley male rats, the control and three experimental groups; one FU-PGA disk insert group(300mg/kg), two FU-PGA disk insert group(600mg/kg), and three FU-PGA disk insert group(900mg/kg). The control group received a similar number of PGA disk inserts. A pharmacokinetic study was performed to measure the 5-fluorouracil concentration in the peritoneal fluid, blood, and tissues(liver, kidney and heart) at 24 hours, 72hours and 168 hours after insertion of the FU-PGA disk. Light and electron microscopic studies were done. The results were as follows: 1) The number of white blood cells and platelets decreased after FU-PGA insertion. The degree was proportional to the duration and amounts inserted. The change in the number of red blood cells varied slightly. 2) Light microscopically, slight changes were noted at 168 hours in the 3 disk insert group (900mg/kg). Mild fatty change and hepatocyte degeneration around the central veins of the liver were noted, with vacuolar degeneration in the proximal convoluted tubules of the kidney. 3) Electron microscopically,the liver showed focal increases of lipid droplets in the hepatocytes, and irregular nuclear membrane with focal nucleolar segregation of the fibrillar and granular elements. Also the double membranous structure of the hepatocytes and Kupffer cells was widened with bleb formation. The kidney showed wide separation of the nuclear double membrane in the proximal convoluted tubular cells and mesangial cells, with vacuolation and myelin figure formation in the mitochondria of the proximal convoluted tubular cells, at 72 hours and 168 hours in the 2 to 3 FU-PGA insert groups. The heart showed focal loss of cristae,vacuolation and myelin figure formation in the mitochondria of the 2 to 3 FU-PGA insert groups. In conclusion, despite the large amont of FU-PGA inserted, the histopathological changes in the liver, kidney and heart were slight, and consonant with the very low amount of 5-fluorouracil concentrations detected in the liver, kidney and heart. The above results suggest that the FU-PGA composite can serve as a new device for releasing drugs in a controlled manner and easily targeted to intraperitoneal organs. This device can improve the efficacy of intraperitoneal chemotherapy for gastric cancer.

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.

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.