Pyriminobac-methyl과 azimsulfuron 합제의 신규제형인 분산형 정제에 대한 독성 평가

백경진,이동연,이상훈,김태원,정두순,임종환,김명석,박병권,윤효인 충남대학교 수의과대학 동물의과학연구소 2004 動物醫科學硏究誌 Vol.12 No.-

Dispersible tablets disintegrate either to form a stabilized suspension rapidly in water, or to disperse instantaneously in the rice field without the aid of water. In this study, the newly formulated dispersible tablet form of herbicidal combination, pyriminobac-methyl and azimsulfuron, was evaluated the safety for human and animals in the toxicological viewpoints. The LD_(50) value of dispersible tablet form for pyriminobac-methyl and azimsulfuron was above 2,500 mg/kg for the oral route and above 2,000 mg/kg for the dermal route. It is considered to have low acute oral and dermal toxicity based on the findings of the present studies. In addition, the combination of pyriminobac-methyl and azimsulfuron showed mild skin irritant under the conditions of this study and conjunctival redness and slight opacity on cornea appeared from 1 hour after application.

Effect of Electrochemical Hydrogen Charging Time on Hydrogen Embrittlement of the Hot-Rolled and Accelerated Cooling Treated API X70 Steel

Dong‑Su Bae,Un‑Bong Baek,Seung‑Hoon Nahm,Ilguk Jo 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.2

This study investigated the effect of the hydrogen charging time on the hydrogen embrittlement of hot-rolled and acceleratedcoolingtreated API X70 steel by using the electrochemical hydrogen charging method. Tensile and V-notch Charpy impacttest were completed for the specimens of hydrogen charged for 0, 2, 4, and 10 h, and then microstructural observation wereperformed. The tensile and yield strength tended to decrease slightly and the total elongation started to decrease rapidly up to2 h charging time and then these gradually decreased with the hydrogen charging time. The post-uniform elongation increasedslightly after the holding time of 2 h due to the occurrence of two-step stress reduction phenomenon and its mechanismhas suggested. The effect of the hydrogen embrittlement on impact absorption energy according to the hydrogen chargingtime were also investigated. The fracture surface of the hydrogen charged ones are generally composed of cleavage fracturesurfaces. It was demonstrated that the external cracks were formed on the outside of tensile tested specimen and the externalshape of the fracture portion was fractured without large elongation at hydrogen charged specimens.

Carbosulfan의 피부자극성, 안점막 자극성 및 피부감작성등의 알러지성 효과에 관한 연구

이상훈,이동연,백경진,김태원,정두순,임종환,김명석,박병권,윤효인 충남대학교 수의과대학 동물의과학연구소 2004 動物醫科學硏究誌 Vol.12 No.-

Many studies have been published on the human health effects of carbosulfan toxicity. Carbosulfan used as an insecticide can produce an irritating and allergenic effect when acting on the skin. In this study, a sensitization test on albino guinea pigs and intradermal reactivity and occular irritation test on albino rabbits were carried out with carbosulfan. Signs of acute skin inflammation appeared along with the clinical symptom of chronic dermatosis caused by the solution irritating characteristics. Moreover, carbosulfan showed severe eye irritation with conjuctival redness and severe opacity on cornea. Preventive measures should involve workers' obligatory instructions on the noxious impact on human skin and strict observance of industrial safety rules.

신규개발된 제초제 metamifop 현탁농축액제에 대한 급성독성평가

이동연,이상훈,백경진,김태원,정두순,임종환,김명석,박병권,윤효인 충남대학교 수의과대학 동물의과학연구소 2004 動物醫科學硏究誌 Vol.12 No.-

Metamifop, (R)-2-[4-[(6-chloro-2-benzoxazolyloxyphenoxy]-N-(2-fluorophenyl)-N-methyl propanamide, was newly developed by Dongbu Hannong Chemicals in Korea. In the present study we conducted acute oral toxicity and acute dermal toxicity test. The values of LD_(50) of metamifop was found to be over 5,000 mg/kg for ICR mice. On the other hand, metamifop showed no acute dermal toxicity to SD rats.

대뇌 기저핵 신경세포 일차배양에서 망간에 의해 유도된 Appoptosis : 형태학적인 소견

신동훈,김상표,정용욱,배재훈,송대규,백원기 大韓産業醫學會 2000 대한직업환경의학회지 Vol.12 No.1

목적 : 본 실험은 대뇌기저핵의 신경세포를 배양하여 망간(MnCl₂)을 투여한 후 망간독성에 의한 신경세포의 apoptosis를 형태학적인 소견으로 관찰하였다. 방법 : 배양된 신경세포에 0.01에서 10μM Mnc12를 48시간동안 처리한 후 TUNEL (TdT-mediated dUTP Nick End Labelling)법 및 투과전자현미경학적으로 관찰하였다. 결과 : TUNEL방법을 이용하여 관찰한 결과 TUNEL반응에 갈색으로 양성반응을 나타내는apoptotic 세포의 수가 대조군에 비해 MnCl₂를 투여한 군에서 유의하게 높게 나타났으며(P〈0.05), 투과전자현미경학적 소견상 대조군의 신경세포들은 핵인(nucleolus)이 두드러지게 특징적으로 보이면서 핵막과 세포질내 소기관들이 잘 보존되어 있으며, 세포질내망(ER)과 사립체(mitochondria)를 특히 많이 가지고 있었다. Mnc12를 48시간 동안 처리한 군에서 이질염색질(heterochromatin)이 핵막으로 이동하면서 응집되어 있었으며, 핵내 불규칙한 형태의 염색질이 나타나 분절이 진행되는 소견을 보였고, Apoptosis의 가장 특징적인 초기 소견인 막으로 둘러싸인 반달모양의 핵내염색질의 분절편(fragment-ed chromatin)과 주위의 상대적으로 정상적인 소기관으로 구성된 apoptotic body를 관찰할 수 있었다. 결론 : 신경세포에서 망간에 의해 apoptosis가 유도됨을 형태학적인 방법으로 확인할 수 있었으며 망간에 의한 세포사망양상에 apoptosis가 하나의 기전이 될 수 있을 것이다. Objectives : Manganese is cytotoxic to the central nervous system including basal gan-glia. Its toxic mechanism is related to oxidative stress, mediated by toxic free radicals but is specultives. In the present study , we have investigated to manifest apoptosis in man-ganese-induced cytotoxicity in primary neuronal cell culture of rat basal ganglia. Methods : To detect apoptotic neuronal cells were stained by the terminal deoxynu-cleotide (TdT) -mediated dUTP nick end-labelling (TUNEL) method and apoptotic changesin nuclei of neurons were observed by electron microscopy. Results : We showed that TUNEL immunostain showed brownish signal in the nuclei of apoptotic cells and the proportions of apoptotic cells in Manganese treatment groups were more higher than controls. On transmission electron microscopy, there were chromatine condensation with margination toward nuclear membrane and condensation of cyto-plasm in the treated with luM MnCl²for 48 hours in a basal ganglia neurons. Apoptotic bodies were found and consisted of semilunar-like condensed nuclei with relatively intact cytoplasmic organelles. Conclusions : Apoptosis appears to be one mechanism in the manganese-induced net-ronal cell death. Manganese intoxication is a convenient model for apoptosis study.

자일리톨과 불화나트륨을 함유한 저작성 정제가 교정환자의 구강위생에 미치는 영향에 관한 임상시험

유상훈,안석준,이신재,백승학,김태우,장영일,남동석 대한치과교정학회 2003 대한치과교정학회지 Vol.33 No.2

본 연구는 불화나트륨과 자일리톨 성분으로 구성된 구강 청정용 저작성 정제(덴포정, 하미즐, 부천, 경기)가 교정치료 중인 환자의 구강위생 상태에 미치는 영향을 알아보기 위해 시행되었다. 교정치료 중인 18세 이상의 성인 환자 30명을 대상으로 약제 상요 전, 2주 후, 4주 후에 피험자의 상악과 하악 전치 부위 및 구치 부위에서 각각 치은 지수, 치은 출혈 지수, 치태 지수를 측정하여 다음과 같은 결과를 얻었다. 1. 상하악 전치부와 구치부 모두에서 치태 지수가 약제 사용 전에 비해 사용 2주 후와 4주 후 유의성 있게 감소하였다(p<0.05). 또한, 적용 2주 후와 4주 후의 지수를 비교하였을 때 4주 후에 좀 더 개선된 경향을 보였으나, 통계적 유의성은 나타나지 않았다(p<0.05). 2. 치은 지수, 치은 출혈 지수도 상하악 전치부와 구치부 모두에서 적용 전에 비하여 2주 후와 4주 후 유의성 있게 감소하였다(p<0.05). 적용 2주 후와 4주 후의 지수의 비교 검증에서 통계학적으로 유의할 만한 차이가 보이지 않아 구강위생 상태의 개선이 계속 유지됨을 보였다. 본 연구의 결과는 치태 지수, 치은 지수, 치은 출혈 지수가 실험 정제 적용 후에 감소하여 구강위생 상태가 개선되었음을 보였다. 이러한 결과를 통해 덴포정을 교정치료 중인 환자에서 부가적으로 사용하였을 경우 치주조직의 건강을 증진시키는데 도움을 줄 수 있으리라고 생각된다. The aim of this study was to evaluate the effect a chewable tablet containing sodium fluoride and xylitol (DenPo, Hamizzle, Bucheon, Kyungki) on the oral hygiene state in the orthodontic patients. The subjects consisted of 30 adult orthodontic patients, who have worn the fixed orthodontic appliance at least 6 months. They were instructed to use the tablet forth a day. Gingival index (GI), plaque index (PI), and sulcus bleeding index (SBI) of upper and lower anterior and posterior regions were measured before using the tablet (TO), 2 weeks after using the tablet (T1), and 4 weeks after using the tablet (T2). The data were analyzed with Wilcoxon signed ranks tests. The results were as follows ; 1. PI was decreased significantly in the T1 and T2 stage compared with TO stage in the both anterior and posterior regions (p<0.05). Although PI was decreased in the T2 stage compared with T1, there was not statistical significance(p>0.05). 2. GI and SBI showed similar results compared with PL. In the T1 and T2 stage, there was statistically significant decrease in the GI and SBI (p<0.05). This study showed that the DenPo tablet could be used as an adjunct to improve oral hygiene in the orthodontic patients. The decrease of the indices may suggest that DenPo tablet could be effective in the plaque removal and prevention of gingival inflammation in the orthodontic patients.

전신성 홍반성 루프스 환자에서 발생한 자가 면역성 간염 1례

김준재,백나나,김현정,전태주,서동대,오태훈,최원충 인제대학교 2008 仁濟醫學 Vol.29 No.-

SLE 환자에서 간 효소 수치의 상승은 여러 가지 원인에 의하여 드물지 않게 관찰될 수 있다. 이 중 자가 면역 기전에 의해 발생되는 질환으로 자가 면역성 간염과 SLE에 동반된 간염이 있으며, 두 가지 질환의 감별은 환자의 예후 및 치료에 중요하다. 따라서 간 조직 검사를 포함한 정확한 진단 기준으로 조기에 진단하여야 하며, 이에 따른 적절한 치료를 통해서 간 부전 및 비가역적 간경변증으로 진행을 방지할 수 있을 것으로 사료된다. Patients with systemic lupus erythematosus (SLE) have a 25-50% chance of developing abnormal liver tests in their lifetime and various causes are related to elevation of liver enzyme, such as hepatic involvement of lupus, hepatotoxic drug, viral infection, autoimmune hepatitis and so on. Discrimination of autoimmune hepatitis from SLE-associated hepatitis is important because complications and therapy are quite different, although both are autoimmune syndromes. Here we are presenting a case of SLE patient with type I autoimmune hepatitis proved with liver biopsy.

수술-교정 치료 환자의 통제 소재

이신재,안석준,백승학,김태우,장영일,양원식,서정훈,남동석 대한치과교정학회 2002 대한치과교정학회지 Vol.32 No.4

교정치료와 악교정 수술을 필요로 하는 환자가 점증하는 현 시점에 비추어, 이에 대한 기술적인 측면의 발전과는 달리 수술-교정 치료 환자에 대한 정신사회학적 혹은 정신심리적 양상에 대한 객관적인 정보는 그리 많은 주목을 받는 편이 아니었다. 수술-교정치료는 과학적인 치료과정이긴 하지만, 어느 정도 심미적 혹은 예술적인 측면을 지니는 선택 치료의 면모를 지닌다. 그러므로 치료에 대한 환자의 주관적인 느낌은 치료 기술이나 치료의 의학적 성공 여부보다 더 큰 영향을 미칠 수 있다. 그러므로, 수술-교정 (혹은 교정) 치료에 대한 환자의 반응을 예측하기 위한 정신심리적인 정보는 치료에 유용한 지표가 될 수 있다고 가정할 수 있다. 통제 소재에 대한 연구는 인간의 다양한 행동을 예측하기 위한 유용한 지표로 알려져 왔는데, 본 연구에서는 42명의 수술-교정치료 환자와 성별/연령별로 표본 추출된 42명의 통상적 교정치료 환자를 대상으로 삼아 정신=심리적 비교 및 분석의 방법으로 두 가지 종류의 내외 통제 소재(internal/external locus of control) 검사를 시행하였다. 그 결과 수술-교정치료군에서만 남자가 여자에 비하여 낮은 외적 통제(높은 내적 통제)의 경향을 보였다. 결론적으로 수술-교정치료 환자의 정신심리적 기반은 성형 수술 환자와는 달리 교정치료 환자와 유사한 경향을 지닌 것으로 생각되었다. Surgical-orthodontic treatment is an increasingly more common dental procedure whose unique psycho-social or psychological feature has not been fairly quantified objectively. Since the treatment of a surgical-orthodontic (or orthodontic) patient is part science and part art, a subjective recognition of a patient about his or her own treatment may be more important than technical success during and after treatment. Therefore, the knowledge of the patient''s underlying psychological status could be useful in the prediction of patient's response to surgical-orthodontic (or orthodontic) treatment. The purpose of this study was to investigate and evaluate the psychological difference between conventional orthodontic patient and surgical-orthodontic patient by using locus of control (LOC) examination. Locus of control scale has been proven to be extremely useful in the prediction of a variety of human behaviors. Two types of locus of control data (I-score, Internal locus of control score ; E-score, External locus of control score) were obtained for 42 surgical-orthodontic patients and randomly selected 42 conventional orthodontic patients (as a control group) matched for age and gender. No statistically significant difference was observed in the scale of internal and external locus of control between the groups of surgical-orthodontic patients, males showed lower E-score (external locus of control score, higher internal locus of control tendency) than females. The results of this study suggested that the psychological background of surgical-orthodontic patients, in contrast with that of cosmetic surgery patients, has a similar disposition with that of orthodontic patients.

납에 의해 유발된 신경세포의 APOPTOSIS

양선희,신동훈,백원기 大韓産業醫學會 1999 대한직업환경의학회지 Vol.11 No.2

Lead is a major environmental and occupational neurotoxicant. It has been shown that long-term exposure to a low level of lead impairs the development of brain. For example, it was reported that lead exposure during the childhood causes a learning difficulty and a memory deficit of children. Neurotoxic agents including the lead are believed to cause neuronal death in developing brain by two mechanisms: apoptosis and necrosis. However, the exact mechanism of neuronal death caused by lead exposure is still not known explicitly. In this study, we conducted a study to clarify a mechanism of hippocampal neuronal cell death caused by lead acetate. Hippocampal neurons were cultured for 14-16days and treated with lead acetate of 1, 10, 100μM concentrations for 12 hours. With the MTT (methyl tetrazolium test)kit, the viability of neuronal cells was measured. Next, in order to examine apoptosis caused by lead acetate, TUNEL(TdT-mediated d-UTP Nick End Labelling ) assay was performed. It has been shown that lead acetate reduced the viability of neuronal cells in a dose dependent manner, especially at the concentration of 100 μM lead acetate. TUNEL immunostain showed brownish signals in the nucleus of apoptotic cells. The proportions of apoptotic cells in the lead-acetate treated group were more higher than those in the controls and increased as lead acetate concentration increased. From above results, it may be concluded that lead in the hippocampal neuronal cells reduced cell viability and one of mechanisms in neuronal cell death by lead appears to be apoptosis.

소음성 감각신경성 난청에서의 Mitochondrial DNA A3243G 돌연변이

정인성,신동훈,백원기 大韓産業醫學會 2000 대한직업환경의학회지 Vol.12 No.3

목 적 : 본 실험은 소음성 감각신경성난청 환자의 말초혈액의 백혈구에서의 분자생물학적인 기법으로 분석하여 mtDNA 돌연변이 (3243A-)G)와 소음성 감각신경성난청과의 관련성을 조사하였다. 방 법 : 소음성 감각신경성난청으로 진단된 환자를 대상으로 말초혈액 백혈구로부터 DNA를 추출한 후, DNA중합효소의 연속적인 반응을 이용하여 DNA를 대량으로 증폭하는 방법, 중합효소연쇄반응 (polymerase chain reaction:이하 PCR)으로 증폭한 후 유전자 제한효소로 소화된 mtDNA frag meat를 2 % 한천 gel에서 전기영동하고 ethidium bromide용액으로 염색하여 UV transilluminator에서 관찰하였다. 그리고 PCR산물을 T-vector를 이용하여 cloning 한 다음 DNA염기서열 분석을 실시하여 mtDNA A3243G 돌연변이를 관찰하였다. 결 과 : MtDNA 돌연변이 부위가 포함된 294bp fragment가 대조군, 감각신경성난청 환자군,그리고 소음성 감각신경성난청 환자군 모두에서 증폭됨을 관찰할 수 있었다. 또한 294 bp fragment가 나타난 P7R산물을 restriction endonuclease Apal으로 처리한 결과 digested fragment(179 bp와 115 bp)를 관찰할 수 없었으므로 mtDNA 돌연변이(3243A-)G)가 일어나지 않았음을 알 수 있었다. MtDNA 돌연변이(3243A-)G)가 관찰되지 않은 PCR산물을 이용하여 DNA 염기서열을 분석하여 mtDNA 3243부위에서의 염기서열을 확인한 결과 이미 밝혀진 사람의 mtDNA 3243부위의 엽기서열과 동일한 염기서열임 이 확인되었으므로 mtDNA 돌연변이(3243A-)G)가 일어나지 않았음을 확인하였다. 결 론 : 소음성 감각신경성 난청, 정상대조군에서도 돌연변이는 관찰되지 않았으므로 소음성 감각신경성 난청과 mtDNA 돌연변이(3243A-)G)는 관련성이 없음을 알 수 있었다. Objectives : A different sequence change, In the mitochondrial tRNA LEU(UUR) gene, has been proposed as a candidate mutation in the sensorineurnal hearing loss. The purpose of current study is to identify the association between the noise-induced sensorineurnal hear- ing loss and the A to G mutation at nucleotide 3243 of mitochondrial DNA. Methods : Subjects were established by history and chart review, and audiological and clinical data were obtained. Blood was sampled from 101 controls, 50 noise-induced hear- ing loss, and 12 sensorineural deafness. The DNA of these individuals was extracted, and mitochondrial genome was analyzed by polymerase chain reaction. Subsequently, the cod inly sequence of mitochondrial genome was sequenced, and compared to the normal sequence, and all sequence variations were analyzed by restriction endonuclease Apal. Results : Mitochondrlal BNA mutation (3243A-)G) was not detected by polymerase chain reaction (PCR) in any patients with noise-induced hearing loss, sensorineural hear-ing loss, and normal control without hearing loss In Koreans. The DNA sequencing of PCR products did not revealed an A to G substitution at nucleotide 3243 of mitochondrial DNA. Conclusions : The noise-induced sensorineural hearing loss was not associated with mitochondrial DNA mutation (3243A-)G).