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.

Ropivacaine 을 이용한 경막의 마취시 Clonidine 병용의 효과

김종일,조영훈,이상곤,민병우,이지향,반종석 대한마취과학회 2001 Korean Journal of Anesthesiology Vol.41 No.4

Effects of Clonidine Added to Ropivacaine in Epidural Anesthesia Young-Hoon Cho, M.D., Ji-Hyang Lee, M.D., Sang-Gon Lee, M.D., Jong-Il Kim, M.D.^*, Jong-Suk Ban, M.D., and Byung-Woo Min, M.D. Department of Anesthesiology, Daegu Fatima Hospital, Daegu, Korea ^*Kim Jong Il Pain clinic, Daegu, Korea Background: Clonidine has been regarded as an adequate supplementary anesthetic during epidural anesthesia and has been used with local anesthetics such as bupivacaine or lidocaine to support the effects of these anesthetics. The authors would examine whether clonidine is an adequate supplementary anesthetic when it is used with ropivacaine during epidural ane-sthesia. Methods: Thirty-two healthy patients undergoing a hip or lower limb surgery were diveded into two groups. In group 1, 0.5% ropivacaine 15 ml was administered. In group 2, 0.5% ropivacaine 15 ml combined with clonidine 150 ㎍ was administered. Onset, duration and maximal height of sensory block were assessed. Sedation score, blood pressure and heart rate were measured. Results: Duration of sensory block of group 2 was significantly longer than that of group 1. Sedation score of group 2 was significantly higher than that of group 1. Blood pressure of group 2 was sig-nificantly lower thatn that of group 1 at 50 min, 70 min and 90 min after epidural injection. No significant differences were observed in onset of sensory block and heart rate between the two groups. Conclusions: The addition of clonidine to ropivacaine during epidural anesthesia prolonged duration of sensory block and produced useful sedation. It caused relatively stable hemodynamic changes. These results suggest that clonidine is an adequate supplementary anesthetic when it is used with ropivacaine during epidural anesthesia. (Korean J Anesthesiol 2001; 41: 428~433)

성악골 절제술후 발생한 중앙부및 구개 결손부의 재건

김훈,임재석,최성원,김호겸,권종진,최미숙,김성문 大韓顎顔面成形再建外科學會 1996 Maxillofacial Plastic Reconstructive Surgery Vol.18 No.1

There are various defects caused by trauma or resection of maignant tumor in the orofacial region, which can be reconstructed with various regional and pararegional flaps. Among these defects, it is very difficult to reconstruct palatal and midfacial defects after maxillectomy and patients have problems in speaking and swallowing of food. Therefore it is very important for surgeons to reconstruct these defects functionally and esthetically and to return the patients to the normal social activity. These defects are usually obturated with prosthodontic appliances to assist the phonation and swallowing. But nowadays surgical reconstruction by various flaps was considered and performed for better rehabilitation. For this purpose the forehead flap, the nasolabial flap, the tongue flap, the sternocleidomastoideous flap, the temporal flap, the latissimus dorsi flap, the scapular flap etc. are used. We reconstructed small-sized plalatal defects with tongue flap, medium-sized palatal and maxillary defects after maxillectomy with temporal myofascial flap and large midfacial defects including eyeball exenteration with latissimus dorsi myocutaneous flaps. Here we are to report 5 cases of these flaps used for the reconstruction of palatal and midfacial defects and consider the versatility, reliability and limitation in use of these flaps.

노치 형상 및 냉각속도에 따른 Zr-2.5Nb 압력관의 DHC거동

김상재,김영석,임경수,김성수,정용무 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.1

The objective of this study is to investigate the delayed hydride cracking (DHC) velocity and the incubation time for the water-quenched and furnace-cooled Zr-2.5Nb tube with the different radius of a notch tip. DHC tests were carried out at constant K_1 of 20 MPa√m and 250℃ on the cantilever beam (CB) specimens subjected to furnace cooling or water quenching after electrolytic charging with 57 or 72 ppm hydrogen, respectively. An acoustic emission sensor was attached to the CB specimens to detect the incubation time before the start of DHC. The shape of the notch tip changed from the fatigue crack to the dull crack with its radius ranging from 0.1 to 0.15 mm. The DHC incubation time increased remarkably with the increasing radius of the notch tip, which appeared more strikingly on the furnace-cooled CB specimens than on the water-quenched ones. However, both furnace-cooled and water-quenched CB specimens indicated little change in the DHC velocity with the radius of the notch tip unless their notch tip exceeded 0.125mm. These results demonstrate that the uncleation rate of hydrides at the notch tip determines the incubation time and the DHC velocity becomes constant after the concentration of hydrogen at the notch tip reaches the terminal solid solubility for dissolution (TSSD). This observation agrees well with Kim's DHC model. A difference in the incubation time and the DHC velocity between the furnace-cooled and water-quenched specimens is discussed in terms of the uncleation rate of hydrides at the notch tip and the hysteresis of hydrogen solubility.

학생체질검사제도에 대한 인식과 개선방안 연구

김귀숙,문정숙,김윤신,이수진,김상욱 韓國學校保健學會 2003 韓國學校保健學會誌 Vol.16 No.1

Recent domestic findings indicate steep increase of geriatric diseases such as obesity, diabetes, and high boll d pressure among children and adolescents. It is, therefore, necessary to establish a new system for constitution inspection th at reflects domestic adolescents' health conditions by the introduction of feasible items and systematic methods in the inspect ion. The objective of this study is to grasp the problems and to present proper ways of improving the system. As the method of the research during the period from September 2001 to March 2002 we refer to the domestic and foreign li terature, and ask the advice of the specialists in pediatrics, family medicine, endocrine, cardiology. As on-site research we us a survey of nationwide elementary, middle, and high schools, visit representative local schools and have an interview with shoo l nurses. Through the interview we try to find practical problem of school heath care and find proper method of students physic al examination. The abstract of the problems of student examination system is as following. To the question about the extent of the resu lt of physical examination 46. 46.4%(school doctor) and 42.6%(parents and students) of the respondents answered "don't know". It means neglectfulness about examination itself. 62% of the school nurses responded "unsatisfactory" people who take charge of practical affairs have complaint about pre sent examination method. Because of the short time of the examination, and numerous students, the examination was incomplete. So veral questions, method of physical examination, content of physical examination and list of physical examination, were raised. Reform measures for physical examination system of students were presented by physician, school nurses, students and parents of student.

피스톤 가공용 CNC 선반 HOT-1000 개발에 관한 연구

김경석,김종관,김상복,김성식,정현철,이도윤 한국공작기계학회 1996 한국생산제조학회지 Vol.5 No.2

The purpose of this study is the development of a lathe which can cut any pistons of oval shape with high speed, accuracy and precision by CNC (computer Numerical Control) method. Y axis which is the mechanism of position determination with high speed response has been aded to the CNC lathe and ovality and profile has been cut under the synchronous control of C-Y-Z axes. In the case of ovality of Φ0.5mm, the productivity can be improved up to 1500rpm by high speed cutting than modeling method.

중증 재생불량성 빈혈 환자에서 신우신염에 대한 광범위항생제치료 중에 속발한 Saccharomyces cerevisiae 진균감염 1예

김철희,이정호,이정찬,강정현,곽상혁,배광봉,김현수,김종숙,조덕연,김삼용 충남대학교 의과대학 지역사회의학연구소 1999 충남의대잡지 Vol.26 No.1

Most patients with aplastic anemia who do not respond to immunosuppressive treatment or are not candidates for bone marrow transplantation die of infection or bleeding. The neutropenia in acute leukemia, aplastic anemia, or occurring subsequently to chemotherapy and bone marrow transplantation increases susceptibility to infection. In general, the number of infectious episodes correlate with the degree and duration of neutropenia. Global immunosuppression produced by conditioning for bone marrow transplantation or graft-versus-host disease, is associated with unusual bacterial and fungal pathogens, or serious viral and protozoan infections. In addition, repeated treatment with broad-spectrum antibiotics is associated with the emergence of resistant organisms and fungal diseases because of the altered microbial microenvironment of the host. The incidence of invasive fungal infection caused by Saccharomycetes eerevisiae in immunosuppressed patients is very rare, compared with that of infection by candida or aspcrgillus species. Cases of Saccharomycetes cerevisiae fungemia occurring in the course of treatment with broad-spectrum antibiotics are reported in patients with extensive burn or with prosthetic valve endocarditis. We experienced a case of urinary tract infection by Saccharomycetes cerevisiae in a 27-year old female patient with severe aplastic anemia. We report the case with a review of relevant literatures.

우라늄 투여후 간조직에서의 효소활성도의 변화

김국찬,이강석,김진규,김인규,박효국,천기정,김상복 대한방사선 방어학회 1993 방사선방어학회지 Vol.18 No.2

우라늄 피폭후 효소활성도가 내부피폭의 biomarker로서의 가능성을 연구하기 위하여 수서생물인 잉어9Caprinus carpio)의 복강내 우라늄 투여시 간조직에서 일어나는 여러가지 효소계의 변화를 조사하였다. 이러한 효소활성도의 변화는 우라늄 내부피폭의 biomarker로서 가능성을 가지고 있으며 연구결과는 다음과 같다. 1) 6일째까지 우라늄을 주사하여 적출한 간에서의 전체단백질량은 계속 감소하고 있다. 2) 세포내의 lysosome내에 함유하고 있는 acid protease와 β-glucuronidase의 활성도는 6일째 투여후까지 활성도가 감소하고 있다. 3) Alkaline phosphatase의 경우 6일째 우라늄 투여후까지 증가하고 있으며 반대로 acid phosphatase의 경우 6일째 우라늄 투여후까지 활성도가 급격히 증가하였고 glutamate oxaloacetate transaminase의 활성도는 완만하게 증가하고 있다. 4) Creatine kinase의 활성도는 완만한 감소를 보이고 있으며 malate dehydrogenase는 첫번 우라늄 투여후에 활성도가 급격히 감소하였고 3일째 우라늄 투여후에는 활성도가 거의 나타나지 않았다. We examined various enzyme activity changes by intraperitioneal injection uranium in the carp liver. These enzyme activity changes can be used as biochemical indicators of internal exposure to uranium. The results were followings ; 1) Total protein concentration decreased by intraperitoneal injection in the carp liver. 2) Lysosomal acid protease and β-glucronidase activities increased in the liver until sixth intraperitoneal injection of uranium, but lysosomal acid phosphatase activities decreased in the liver until the sixth injection of uranium. 3) Alkaline phosphatase activities sharply increased and Glutamate oxaloacetate Transaminase activities steadily decreased in the liver until the sixth injection of uranium. 4) Creatine %kinase activities steadily decreased and malate dehydrogenase activities sharply decreased in the liver after the primary injection of uranium. Any malate dehydrogenase activities was not detected after sixth injection of uranium.

Atomic Force Microscopy를 이용한 Al0.5Ga0.5As/GaAs 다중 에피층 구조의 단면관찰에 관한 연구

김희진,김재성,김용,김무성,민석기 숙명여자대학교 자연과학연구소 1994 자연과학논문집 Vol.- No.5

다중 에피층 구조(Al0.5Ga0.5As/GaAs)의 단면을 AFM(atomic force microscopy)으로 관찰하는데 성공하였다. AFM을 이용한 다중 에피층 구조의 단면 관찰은 0.1M HCl을 이용해서 이미 다른 그룹에서 관찰한 바가 있으나, 본 실험에서는 처음으로 5% NaClO용액을 사용하여 시료를 선택에칭(stain etching)처리하였고, 선택적 산화와 에칭으로 AlGaAs와 GaAs를 서로 구분해 내었다. 5% NaClO로 처리한 시료의 AFM 이미지는 3초 미만 에칭하여도 관찰이 가능했다. 층간 구분이 선명하였고, 심지어 NaClO에 의한 GaAs층의 에칭 morphology까지 확인했다. 10mm정도의 구조는 쉽게 AFM을 이용해서 관찰이 가능했다. 반대로 0.1M HCl용액으로 에칭한 AFM이미지는 상대적으로 좋지 못한 것을 확인했고, 이것으로 HCl용액의 에칭선택성이 5% NaClO에 비해서 좋지 못함을 알 수 있었다. 5% NaClO용액을 사용한 단면관찰은 간단한 시료준비와 짧은 측정시간으로 nanostructure연구에 많은 활용이 있을 것으로 기대된다. We investigate the cross-section of Al0.5Ga0.5As/GaAs multilayered epitaxial structure by an atomic force microscope to see the feasibility of the technique. For the first time, we employ 5% NaClO etchant to discern each layer and obtain well resolved AFM images of the layers whose thicknesses are about nanometer scale. In contrary, we get relatively poor AFM images by applying. HCl etchants and it is attributed to poor Al0.5Ga0.5As/GaAs etching selectivity of HCl solution compared to that of 5% NaClO solution.

냉동 제대혈 세포의 체외 증폭

김삼용,김철희,배광봉,김현수,박상준,김종숙,윤환중,조덕연 충남대학교 암연구소 1998 癌共同硏究所 硏究誌 Vol.2 No.1

Background : Cord blood(CB), which has no HLA restriction, is an alternative to bone marrow for hematopoietic stem cell transplantation. The use of cord blood, however, is limited by the number of progenitor/stem cells necessary to reconstitute the older child or adult. Therefore, ex vivo expansion of CB could have tremendous impact on diverse clinical settings. We studied the ex vivo expansion of isolated population of CD34_(+) cells from cryopreserved CB cells. Methods : CD34 cells were isolated from cryopreserved CB mononuclear cells. Purified cells were cultured with various combinations of hematopoietic growth factors including erythropoietin(EPO), stem cell factor(SCF), granulocyte-colony-stimulating factor(G-CSF), gra-nulocyte, macrophage-colony-stimulating factor(GM-CSF), interleukin-1β(IL-1β), 1L-3, and IL-6. After 7, 10 or 14 days of culture, the fold increases of colony-forming unit- granu-locyte, macrophage(CFU-GM), burst-forming unit-erythroid(BFU-E), colony-forming unit-mix (CFU-Mix), and high proliferative potential colony-forming cell(HPP-CFC) were evaluated. Results : Ten-day culture with the combination of EPO, SCF, G-CSF, IL-1β, and IL-3 resulted in a median of 60-fold increase of CFU-GM, which was greater than those with the combinations of less than 5 growth factors. The addition of IL-6 or GM-CSF to this combination did not enhance CFU-GM expansion. Ten-day culture was significantly superior to 7-day culture for CFU-GM expansion. Prolongation of culture to 14 days, however, revealed decreased expansion of CFU-GM compared to 10 days. BFU-E and CFU-Mix were expanded to 2~5 folds in 7-day culture with the combination of EPO, SCF, and G-CSF. Further expansion was not achieved in 10-day culture and colonies disappeared in 14-day culture. HPP-CFC was expanded to a median of 7.5 folds in 7-day culture with the combination of EPO, SCF, G-CSF, IL-1β, IL-3, and IL-6. Neither 10-day or 14 day-culture enhanced expansion of HPP-CFU. Conclusion : Cryopreserved cord blood cells maintain ex vivo expansion potential. In our system, 10-day culture with the combination consisting of EPO, SCF, G-CSF, IL-1β, and IL-3 seems to be adequate for hematopoietic progenitor/stem cell expansion from cryopreserved cord blood cells.