• 한국토양비료학회지
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• 제45권4호
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• pp.593-601
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• 2012

Heavy metals and metalloids removal can be considered as one of the most important world challenges because of their toxicity and direct impact on human health. Many processes have been introduced but biological processes of remediation seem to offer the most suitable solution in terms of efficiency and low cost. Actinobacteria constitute one of the major microbial populations in soil, and this can be attributed to their adaptive morphological structure as well as their exceptional metabolic power. Among microbes, actinobacteria are morphologic intermediate between fungi and bacteria. Studies on microbial diversities in metal contaminated lands have shown that actinobacteria may constitute a dominantly active microbiota in addition to ${\alpha}$ Proteobacteria. Furthermore, isolation studies have shown metal removal mechanisms which are reminiscent of notable multiresistant strains, such as Cupriavidus metallidurans. Apart from members of genus Streptomyces, which produce more than 90% of commercialized antibiotics, and the nitrogen fixing Frankia, little attention has been given to other members of this phylum. This is because of difficult culture condition requirements and maintenance. In this review, we focused on specific isolation of actinobacteria and their potential applications in metal bioremediation and plant growth promotion.

• Environmental Analysis Health and Toxicology
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• 제15권3호
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• pp.61-67
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• 2000

Toxic lesions of styrene in the Japanese Medaka (Oryzias latipes) were compared with those of styrene oxide, the active metabolite of styrene, using embryo-larval assays. The developmental stages of Japanese Medaka (Oryzias latipes) treated with both chemicals were not altered and progressed normally. However, styrene oxide was more toxic than styrene in terms of causing death and lesions . High concentrations of styrene (higher than 4.9 ppm) and styrene oxide (higher than 2.4 ppm), resulting in more than 50% mortality, caused similar lesions of cardiovascular system, craniofacial bone formation and spinal deformities, although a number of lesions were not observed by both chemicals . In the group treated with styrene, eyeball sizes and intereye distances were reduced, while, in the group treated with styrene oxide , the eyes and eye cups were not developed and two eyes were sometimes fused. In addition, styrene oxide caused the lesion which involved the posterior brain and brain stem were herniated through the spinal cord . The noticeable difference of toxic symptoms between these two chemicals was the time of onset. Toxicities of cardiovascular system and craniofacial bone formation appeared on day 3 of development in styrene oxide treated group, but, styrene treated group staned to show hemorrhages on day 3 and the craniofacial malformation were appeared on day 5, These differences between two chemicals may be due to the metabolism of styrene to styrene oxide, the reactive intermediate.

• Toxicological Research
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• 제18권3호
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• pp.215-226
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• 2002

Acute or repeated physical exercise affects a large number of physiological parameters including hemodynamics, respiration, pH, temperature, gastrointestinal function and biotransformation, which determine the pharmacokinetics of drugs and chemicals. The rate and the amount of a chemical reaching the active site are altered by physical exercise, which results in significant changes in pharmacolosical/toxicological activity of the chemical. This aspect of physical exercise has vast implication in therapeutics and in safety evaluation, particularly for chemicals that have a low margin of safety. However there appears to be a wide inter- and intraindividual variation in the effects of physical exercise depend-ing on the duration, intensity and type of exercise, and also on the properties of each chemical. It is suggested that more studies need to be done to determine which factor(s) plays a major role in the disposition of chemicals in human/animals performing physical exercise. Certain chemicals induce severe toxicity due to metabolic conversion to reactive intermediate metabolites. it is suggested that repeated exercise may enhance the free radical scavenging system by increasing the activity of antioxidant enzymes. This area of research remain to be explored to elucidate the interaction of exercise and chemical on the antioxidant system.

• 한국수산과학회지
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• 제40권5호
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• pp.282-287
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• 2007

Chloroanilines are aromatic amines used as intermediate products in the synthesis of herbicides, azo-dyes, and pharmaceuticals. 3,4-dichloroaniline (DCA) is the degradation product of some herbicides (diuron, propanil, and linuron) and of trichlorocarbanilide, a chemical used as an active agent in the cosmetic industry. The compound, however, is considered a potential pollutant due to its toxicity and recalcitrant property to humans and other species. With the increasing necessity for bioremediation, we sought to isolate bacteria that degraded 3,4-DCA. A bacterium capable of growth on 3,4-DCA as the sole carbon source was isolated from seaside sediment using a dilution method with a culture enriched in 3,4-DCA. The isolated strain, YM-7 was identified to be Pseudomonas sp. The isolated strain was also able to degrade other chloroaniline compounds. The isolated strain showed a high level of catechol 2,3-dioxygenase activity on exposure to 3,4-DCA, suggesting that this enzyme is an important factor in 3,4-DCA degradation. The activity toward 4-methylcatechol was 53.1% that of catechol, while the activity toward 3-methylcatechol, 4-chlorocatechol and 4,5-chlorocatechol was 18.1, 33.1, and 6.9%, respectively.

• 방사선산업학회지
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• 제6권3호
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• pp.205-209
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• 2012

The decomposition of 50 pesticides present in an aqueous solution using ${\gamma}-irradiation$ from a $^{60}Co$ gamma-ray source was investigated using laboratory-scale experiment. The rates of decomposition were determined using a gas chromatography-electron capture detector (GC-ECD), high-performance liquid chromatography-photo diode array detector (HPLC-PDA), and HPLC-fluorescence detector (FLD). When the initial concentration of pesticides was 10 ppm, and the radiation dose was 2, 5, 10, 20, and 30 kGy, respectively, 14 pesticide samples showed high removal rates (>50%) at absorbed doses of more than 10 kGy. With the exception of procymidone, they were all completely removed at a 30 kGy irradiation dose. These results provide fundamental data on the reactivity between gamma-irradiation and pesticides in an aqueous solution. Further, an evaluation of the toxicity of radiolytic intermediate products is required.

• 한국환경농학회지
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• 제10권2호
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• pp.167-177
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• 1991

O,S-dialkyl alkylphosphonothioates 계열 유기인제 농약의 체내 작용기작을 이해하기 위하여 model 화합물 (1), O-ethyl S-methyl ethylphosphonothioate [$LD_{50}$(rat, oral) 4.6mg/kg ; $K_i$(bovine erythrocyte acetylcholinesterase) 303 $M^{-1}min^{-1}$]이 선정되었다. 이 유기인계 화합물들은 체내에서 활성화(活性化) 과정을 겪으면서 독성(毒性)을 발현하는 것으로 가설(假說)되어져 왔다. 생체 내 mixed function oxidases에 의한 산화 활성화 과정을 화학적(化學的)으로 재현하기 위하여 두 종류의 유기산화제 즉, meta-chloroperoxybenzoic acid와 monoperoxyphthalic acid가 사용되었고, 대사적(代謝的) 산화를 재현하기 위하여 쥐 간(肝)에서 추출한 microsomal oxidation system을 이용한 in vitro 산화반응이 시도되었다. 산화반응 중간생성물인 S-oxide의 존재가 전구물질(1)의 가설적 산화 반응경로를 통해서 간접적으로나마 충분히 확인 되어질 수 있었다. 더욱이 ethanol을 이용한 trapping 실험에서 불안정한 산화중간물질인 S-oxide가 강한 phosphorylating agent라는 것이 확인되어, 전구물질 (1)로부터 산화반응을 거치면서 생성된 이 중간물질이 체내 신경전달에 중요한 역할을 하는 acetylcholinesterase를 phosphorylation하게 되고, 결국 이런 활성화 과정을 통해 이 계열의 화합물들이 독성을 발휘하는 것으로 이해될 수 있었다.

• 대한본초학회지
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• 제33권2호
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• pp.69-77
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• 2018

Objectives : Daesiho-tang (DSHT) has been widely used in the treatment of cerebral infarct in traditional medicine. However, there was not report on the anti-obesity-related diseases efficacy of DSHT. In this study, we investigated the effects for the new formulation of DSHT, on the adipocyte differentiation cycle in 3T3-L1 cells. Methods : 3T3-L1 cells were treated with DSHT (50, 100, $200{\mu}g/m{\ell}$) during differentiation for 6 days. Also, the inhibitory effect of DSHT against 3T3-L1 adipogenesis was evaluated in various stage of adipogenesis such as early (0-2day), intermediate (2-4day), and terminal stage (4-6day). The accumulation of lipid droplets was determined by Oil Red O staining. and, the expressions of genes related to adipogenesis were measured by RT-PCR and Western blot analyses. Results : DSHT showed inhibitory activity on adipocyte differentiation at 3T3-L1 preadipocytes without affect cell toxicity as assessed by measuring fat accumulation and adipogenesis. In addition, DSHT significantly reduced the expression levels of several adipocyte marker genes including proliferator activated $receptor-{\gamma}$ ($PPAR-{\gamma}$) and CCAAT/ enhancer-binding $protein-{\alpha}$ ($C/EBP-{\alpha}$). Also, the anti-adipogenic effect of DSHT was strongly limited in the intermediate (2-4 day), terminal stage (4-6 day) of 3T3-L1 adipogenesis. In addition, the DSHT treatment down- regulated mRNA expression levels of $PPAR-{\gamma}$,, $C/EBP-{\alpha}$ in mature 3T3-L1 adipocytes. Conclusions : These results suggest that, the ability of DSHT has inhibited overall adipogenesis and lipid accumulation in the 3T3-L1 cells. The new formulation of DSHT may be a promising medicine for the treatment of obesity and related metabolic disorders.

• 문화기술의 융합
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• 제10권2호
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• pp.407-417
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• 2024

이 연구의 목적은 유해화학물질 중 하나인 염소를 운송하는 차량이 사고 등으로 전복되어 가스 누출 시 염소독성(ppm)에 의해 예상되는 피해를 예측하고 최소화를 위한 효율적 대응방안을 마련하는데 있다. 피해예측을 위해 염소차량 운행 중 운전자의 부주의 등으로 발생할 수 있는 염소 누출에 따른 독성(ppm) 피해거리를 ALOHA 프로그램을 적용하여 정량적으로 산정하였다. 독성가스 누출시 피해거리는 누출된 위험물의 양과 누출당시의 기상조건 등에 영향을 받는다. 따라서 위험물질의 누출량과 기상조건의 다양한 변화를 통해 피해거리를 다각적으로 분석하였다. 중간 이하의 조건(누출량:5ton, 풍속:3m/s, 대기안정도:D)으로 산정한 피해거리는 AEGL-2의 경우(LOC:2ppm) 9km로 나타났으며, 이는 염화수소의 독성과 유사하고 심각한 호흡장해 등 인명피해를 발생시킬 수 있는 농도이다. 특히, 도심지역에서의 누출은 대규모 인명피해로 연결될 수 있다. 이에 누출사고 발생 시 누출지점 및 누출량에 따른 적절한 대응을 통해 피해를 최소화 하는 방안을 제시하였다.

• 동의생리병리학회지
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• 제16권4호
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• pp.720-723
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• 2002

To clarify the vasculotoxicity of reactive oxygen intermediate(ROI) in cultured vascular endotherial cells(VEC), of mouse, cytototoxicity was measured by MTS assay after VEC was incubated to 10～80mU/ml xanthine oxidase(XO) and hypoxanthine(HX) for 2 hours. and also, the protective effect of Radix Polygoni Multiflori(RPM) was determined by MTT assay in these cultrures. Cell viability was positively decreased dose-, and time-dependently, after the treatment with 40mU/ml XO/0.1 mM HX to cultured VEC for 2 hours. In the vasculoprotective effect of RPM on the toxicity induced by XO/HX, RPM prevented the XO/HX-induced cytotoxicity in these cultures. From above the results, it suggests that XO/HX is toxic in cultured VEC and herb extract, RPM has protective effect against the vasculotoxicity induced by XO/HX.

• Journal of Korean Neurosurgical Society
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• 제57권5호
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• pp.315-322
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• 2015

Intracranial germ cell tumors (ICGCT) occur in 2-11% of children with brain tumors between 0-19 years of age. For treatment of germinoma, relatively low radiation doses with or without chemotherapy show excellent 10 year survival rate of 80-100%. Past studies showed that neoadjuvant chemotherapy combined with focal radiotherapy resulted in unacceptably high rates of periventricular tumor recurrence. The use of generous radiation volume which covers the whole ventricular space with later boost treatment to primary site is considered as standard treatment of intracranial germinomas. For non-germinomatous germ cell tumors (NGGCT), 10-year overall survival rate is still much inferior than that of intracranial germinoma despite intensive chemotherapy and high-dose radiotherapy. Craniospinal radiotherapy combined with cisplatin-based chemotherapy provides the best treatment outcome for NGGCT; 60-70% of overall survival rate. There is a debate on the surgical role whether surgery can contribute to improved treatment outcome of NGGCT when added to combined chemoradiotherapy. Because higher dose of radiotherapy is required for treatment of NGGCT than for germinoma, it is tested whether whole ventricular irradiation can replace craniospinal irradiation in intermediate risk group of NGGCT to minimize radiation-related late toxicity in the recent studies. To minimize the treatment-related neural deficit and late sequelae while maintaining long-term survival rate of ICGCT patients, optimized administration of chemotherapy and radiotherapy should be selected. Use of technically upgraded radiotherapy modalities such as intensity-modulated radiotherapy or proton beam therapy is expected to bring an improved neurocognitive outcome with longitudinal assessment of the patients.