방사선조사가 Porphyromonas gingivalis에 미치는 영향

이창환,김규태,최용석,황의환 대한구강악안면방사선학회 2008 Imaging Science in Dentistry Vol.38 No.1

Purpose : The aim of this study was to observe a direct effect of irradiation on the periodontopathic Porphyromonas gingivalis (P. gingivalis). Materials and Methods : P. gingivalis 2561 was exposed to irradiation with a single absorbed dose of 10, 20, 30, and 40 Gy. Changes in viability and antibiotic sensitivity, morphology, transcription, and protein profile of the bacterium after irradiation were examined by pour plating method, disc diffusion method, transmission electron microscopy, RT-PCR, and immunoblot, respectively. Results : Viability of irradiated P. gingivalis drastically reduced as irradiation dose was increased. Irradiated P. gingivalis was found to have become more sensitive to antibiotics as radiation dose was increased. With observation under the transmission electron microscope, the number of morphologically abnormal cells was increased with increasing of irradiation dose. In RT-PCR, decrease in the expression of fimA and sod was observed in irradiated P. gingivalis. In immunoblot, change of profile in irradiated P. gingivalis was found in a number of proteins including 43-kDa fimbrillin. Conclusion : These results suggest that irradiation may affect the cell integrity of P. gingivalis, which is manifested by the change in cell morphology and antibiotic sensitivity, affecting viability of the bacterium.

치환용매 변화에 따른 비대칭 Ceellulose Acetate 막의 기체투과특성

정광보,장승현,남석태 한서대학교 산학협력연구원 부설 환경연구소 2000 환경연구소 논문집 Vol.3 No.-

Gas permeation behavior was examined for asymmetric cellulose acetate membrane prepared by changing the acetone evaporation time and drying solvent. By changing the acetone evaporation time, the gas permeation rate decreased for the first 2 minutes and then increased gradually for the membrane of i-PrOH exchange drying. Gas permeation rate was in the order of He>N₂>O₂ and separation factor was about 1.9 for the membrane of 9 minute acetone evaporation. The permeation mechanism appears to be the combination of Knudsen flow and viscous flow. The effect of Knudsen flow was increased with acetone evaporation time, while the effect of viscous flow increased for the membrane of EtOH exchange drying.

Newcastle Disease Virus의 Fusion 단백 유전자의 제한효소분절형태(RELP)의 특이성

장경수,김지영,김석,김태용,송영환,허지연,김현수,송희종,전무형 충남대학교 수의과대학 동물의과학연구소 2001 動物醫科學硏究誌 Vol.9 No.-

To evaluate the specificity of restriction fragment length polymorphism (RFLP) of Newcastle disease virus (NDV) fusion (F) protein gene for various NDV strains. F protein genes of NDV CBP-1 isolate, LaSota, B1 and Kyojungwon (KJW) were amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) and RFLP were examined. In RT-PCR using F primer sets for 1.7 kb F gene, the amplified products were observed in CBP-1, LaSota and B1 except KJW. However, F2 primer set for 521 bp yielded the amplified bands with all strains. The amplified F genes (1.7 kbp) were treatd with 15 different restriction enzymes to analyze RFLP and the cleavage patterns. CBP-1 showed various cleavage patterns with 8 enzymes, LaSota, with 11 enzymes and B1, with 11 enzymes. According to the cleavage patterns, the physical maps were constructed, and it was found that CBP-1, LaSota and B1 strains had specific cleavage sites with HinfI, XbaI and XhoI. These findings suggest that RFLP are worth applying in the diagnosis and molecular epidemiological studies of Newcastle disease.

원자력 사고 중 핵종의 건·습침적에 따른 농작물 오염 영향

황원태,김은한,서경석,한문희,최용호,이창우 대한방사선 방어학회 2002 방사선방어학회지 Vol.27 No.3

핵종의 지표 침적 모델의 고찰과 함께 방사성물질의 공기중 농도로부터 건침적 뿐 아니라 습침적에 따른 농작물 오염 영향을 분석, 고찰하였다. 이를 위해 방사성물질의 지표 침적량으로부터 농작물의 오염을 평가하는 기존 동적 섭식경로모델을 공기중 농도 또는 지표 침적량으로부터 평가할 수 있도록 개선하였다. 평가결과, 방사성물질의 지표 침적량은 습침적에 의한 영향이 건침적에 의한 영향보다 뚜렷이 높으나, 농작물의 오염정도는 핵종, 강우율 등에 따라 다르게 나타났다. 이러한 현상은 방사성물질의 지표 침적과 농작물에로의 차단중 어느 과정이 농작물 오염에 보다 지배적으로 작용하는가에 기인한다. Combined with deposition model onto the ground of radionuclides, the influence of radioactive contamination to agricultural products was analyzed due to wet deposition as well as dry deposition from radioactive air concentration during a nuclear emergency. The previous dynamic food chain model, in which initial input parameter is only radionuclide concentrations on the ground, was improved for the evaluating of radioactive contamination to agricultural products from either radionuclide concentrations in air or radionuclide concentrations on the ground. As the results, in case of deposition onto the ground, wet deposition was more dominant process than dry deposition. While the contamination levels of agricultural products were dependent on the a variety of factors such as radionuclides and rainfall rate. It means that the contamination levels of agricultural products are determined from which is more dominant process between deposition on the ground and interception onto agricultural plants.

약물치료에 가역적 회복을 보인 갈색세포종에 동반된 확장성 심근증 1례

홍숙경,최현,이승철,천경일,김영철,한재룡,김미숙,정경태,박순창 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.2

토끼에서 신델라 겔 ( 송아지의 제단백혈액추출물 황산 미크로노아이신 = 20 1 혼합물 ) 의 피부자극성시험

남석우(Suk Woo Nam),이영진(Young Jin Lee),고영권(Young Kwon Ko),장만식(Man Sik Chang),최완수(Wahn Soo Choi),김규봉(Kyu Bong Kim),우태욱(Tae Wook Woo),한정환(Jeung Whan Han),홍성렬(Sung Youl Hong),이향우(Hyang Woo Lee) 한국응용약물학회 1996 Biomolecules & Therapeutics(구 응용약물학회지) Vol.4 No.4

This study was conducted to investigate the skin irritation toxicity of Syndella gel, a combination topical drug containing a deproteinised dialysate of calfs blood and micronomicin sulfate in the ratio of 20 to 1, in New Zealand White rabbits. In the primary skin irritation test with male New Zealand White rabbits, there was no treatment-related effect on clinical sign, and body weight was not significantly changed. The Primary Irritation Index (PII) was 0.33, indicating that Syndella gel was a mildly irritating formulation.

가속수명실험을 이용한 케이블 절연재료의 수명특성에 관한 연구

남창우,이규철,박홍태,이태식,김경석 울산대학교 1997 공학연구논문집 Vol.28 No.1

본 연구는 고체절연재료의 수명예측의 일환으로서 가속수명실험을 통해 얻은 수명데이터의 통계학적 처리방법과 복합 스트레스와 수명과의 상호관계를 규명하기 위한 수명모델을 제시하고 있다. 가속수명실험을 통해 얻는 수명데이터는 와이블분포에 적용하고, 최소자승법과 최우추정법을 이용하여 와이블분포함수의 모수를 추정하였다. 또한 제시된 수명모델의 상수를 추정하여 복합스트레스와의 관계를 규명함으로써 수명모델의 타당성을 입증하였다. 추정결과, 주위온도와 인가전압이 상승함에 따라 수명은 현저히 짧아지고, 수명모델의 상수는 복합스트레스에 크게 의존하는 것으로 나타난다. 따라서 본 연구에서 제시된 수명모델은 고체절연재료의 수명을 나타내는데 적당한 것으로 나타났다. This paper suggests the statistic method for a lifetime estimation of solid insulating materials using the data obtained from accelerated aging test has been performed to obtain the lifetime data. The multi-stress including thermal and electrical stress has been applied to accelerate the degradation of insulating materials. The Weibull Cumulative Distribution Function has been used to treat statistically the lifetime data. Using the lifetime model of this study, we estimated the lifetime constants to show the relationship between the lifetime and the applied multi-stress. It has been shown that the lifetime model agrees well with the lifetime of solid insulating materials.

하악골에 발생한 변연성골종

허민석,안창현,박태원,이삼선,최순철 大韓口腔顎顔面 放射線學會 1999 Imaging Science in Dentistry Vol.29 No.2

Purpose: To determine the clinical and radiological feature of peripheral osteoma of the mandible (POM) in a Korean population and to compare with previous reports. Materials and Methods: Sixteen cases of POM found in 15 Korean patients who visited Seoul National University Dental Hospital between 1980 and 1998 were reviewed to determine their clinical and radiological features. Results: The 15 patients, five males and ten females, ranged in age from 22 to 69 years, with a mean age of 40.7 years. Six POMs were located on the buccal side of the mandibular body and five on the lingual aspect of the mandibular body and five on the lower border of the mandible. The duration of the lesion ranged between 1 and 10 years. The size of the lesions, in their great diameter, ranged from 6 to 26 mm, with a mean of 14.1 mm. Six POMs were pedunculated, nine sessile, and one bell-shaped. Eleven POMs were compact types and five were cancellous ones. Conclusion: The clinical and radiological features of these Korean series were broadly consistent with those of non-Korean populations reported previously. The principal difference was that all POMs under 35 year-old age were compact types.(J Korean Oral Maxillofac Radiol 1999;29:523-532)

한국인 관상동맥의 변화양상에 대한 형태학적 연구

권태정,이상용,이한영,고영창,권기석,조재홍,김태공,김유훈,조갑래,서중석,이원태 內務部 國立科學搜査硏究所 2001 國立 科學 搜査 硏究所 年報 Vol.33 No.-

폐실질내의 주변형 결절로 나타난 소세포성 폐암의 CT 소견

이태희,최요원,전석철,서흥석,함창곡,박충기 한양대학교 의과대학 1998 한양의대 학술지 Vol.18 No.2

We evaluated CT findings of the small cell carninoma, which presented as a solitary pulmonary nodule at the periphery of the lung parenchyma. Of pathologically-proven 45 patients with small cell carcinoma, 10 patients was included in this study, who had a solitary, peripheral lung nodule at distal portion of the subsegmental bronchus. We retrospectively reviewed clinical data and CT findings including size, location, margin, enhancement pattern, lymph node enlargement, metastasis. Peripheral small cell carcinomas were 22.2%(10/45). All masses had well-defined margin and lobulated margin was seen in 7 patients. Mean diameter was 3.8cm (2.5-7.0cm). Enhancement pattern were homogeneous in 3 cases and inhomogeneous in seven. Calcification or air-bronchogram was not present, and focal cavitation was seen in one case. In five, only lung mass was present, and lung mass with lymph node enlargement was seen in one. distant metastasis without lymph node enlargement was noted on two patients and another two patients showed lymph node enlargement and distant metastasis. Peripheral small cell carcinoma is not rare(22.2%). Most frequent CT finding is a well-defined, lobulated mass with inhomogeneous enhancement, these findings would be helpful in differentiating small cell carcinoma from other neuroendocrine tumors when differentiataion is difficult cytologically.