• 미생물학회지
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• 제40권3호
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• pp.232-236
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• 2004

Streptomyces coelicolor A3(2)의 acetyl xylan esterase (AxeA)가 Escherichia coli의 과산화수소 저항성에 미치는 영향을 알아보고자 하였다. AxeA 발현은 isopropyl-$\beta$-thiogalactoside로 유도되었고 생산된 AxeA는 SDS-polyacrylamide gel electrophoresis방법으로 확인하였다. AxeA 발현에 따른 과산화수소 저항성의 변화를 E. coli의 생장곡선과 생존율을 통하여 조사하였다. AxeA가 발현되지 않으면 모든 처리 농도 (1 mM, 2.5mM, 5mM)에서 균의 사멸이 일어났다. AxeA가 발현되는 조건에서는 5mM을 제외한 과산화수소 1mM와 2.5mM에서 E. coli의 사멸이 저지되었다. 또한 1.5mM의 과산화수소에 대한생존율이 59%에서 74%로 높다졌다. 동시에 E. coli의 최고생장온도에서에 근접한 $45^{\circ}C$에서의 생존율도 증가되는 결과를 얻었다. 그러므로 AxeA 단백질은 산화적 스트레스와 온도스트레스에 대해 교차 저항성을 나타내는 역할을 한다고 결론지었다.

• 한국수산과학회지
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• 제1권1호
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• pp.45-49
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• 1968

인천산 굴, Crassostrea gigas, 담륜자의 치사율에 미치는 염도, 온도, 그리고 혼영도의 영향에 관하여 연구하였다. 1. 정상해수로부터 저염도 혹은 고염도인 해수로 옮겨진 굴의 탐륜자는 차차 생명력을 잃었다. 담륜자의 치사율은 각각 저염도인 15 ppt에서 $46\%$이었고 고염도인 35ppt에서는 $47\%$이었다. 2. 고온도인 $40^{\circ}C$ 이상은 정상해수중의 담륜자에 대하여 치사요인이 있고, 특히 $45^{\circ}C$에서는 30분이내에 모두 사망하였다. 그리나 저온은 고온에 비하여 그렇게 치사적인 요인이 아니었다. 각 온도의 30분과 1시간 처리에서 나타난 두 치사곡선간의 차이는 통계학적으로 유의하지 않았다 (P>0.05). 3. 농혼탁도 ($1\%$)는 담륜자의 치사율에 대하여 처리후 단시간내에는 별로 영향을 주지 않았다.

• 한국패류학회지
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• 제20권1호
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• pp.93-105
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• 2004

Arkshell clams, Scapharca broughtonii, are economically important edible bivalves and widely cultivated in the Southern coast of Korea. Recently, the production of S. broughtonii has been dramatically decreased and various reasons including chemical pollution were suspected to be related to the production declines. However, it remains unknown whether the chemical pollution levels of the surrounding environments were high enough for the biological and ecological disturbance for the population of S. broughtonii, because no systematic toxicological study using S. broughtonii has been conducted previously. In the present study, we exposed arkshell clams, S. broughtonii to various waterborne pollutants including heavy metals (Cd, Cu and Hg), ammonia and organotins (tributyltin and triphenyltin) to determine the effect concentrations of these pollutants for the survival of S. broughtonii for 20 days. The median lethal concentrations ($LC_50$) of S. broughtonii were 2.1 mg/l for Cd, 0.065 mg/l for Cu, 0.40 mg/l for Hg, 79.4 mg/l for total ammonia (1.9 mg/l for unionized ammonia), 0.5 ${\mu}$g/l for TBT, and 14${\mu}$g/l for TPhT. Lethal toxicity of the most pollutants increased with both exposure duration and concentration. The toxicity of TBT was greatest for S. broughtonii, followed by TPhT > Cu > Hg > Cd > ammonia. The sensitivities of S. broughtonii to heavy metals and TBT were comparable to those of other aquatic organisms, but they were relatively tolerable to ammonia. The environmental concentrations of the tested pollutants were compared with the effect concentrations of those for the survival of S. broughtonii to assess the potential risks of the pollutants in the field conditions.

• 생약학회지
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• 제23권2호
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• pp.89-95
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• 1992

The water extract of Gamidaebo-Tang depressed the lethal toxicity of cis-platin$(45{\mu}M/kg,\;s.c.)$, and mitomycin C (6mg/kg, s.c.). Significant depression of renal toxicity(indicated by an increased blood urea nitrogen value and creatinine value) of cis-platin $(35{\mu}M/kg)\;s.c.)$, was observed in mice treated with Gamidaebo-Tang. In rats treated with mitomycin C and Gamidaebo-Tang, the increased LDH activity and reduced total protein and albumin contents by mitomycin C were significantly depressed. The number of WBC was significantly increased in rats treated with mitomycin C but in the rats treated with mitomycin C and Gamidaebo-Tang, the number of WBC was increased and the hematocrit value and the number of RBC and Hgb were significantly increased in the dose-dependent manner. Therefore, bone marrow toxicity of mitomycin C in the rats treated with Gamidaebo-Tang was depressed. In the end, alleviative effects of the side actions of cis-platin and mitomycin C were acknowledged by combined usage of Gamidaebo-Tang and these anti-neoplastic drugs.

• 생명과학회지
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• 제7권4호
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• pp.377-383
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• 1997

The acute toxicity effect of triorganotin of trioganotin on the growth of microalgae and shellfish was investigated through flask culture. The value of 120 hr-LC$_{50}$ that is the median lethal concentration of TBTO on the shellfish (R. philipinarum) was found to be 6 $\mu$g/L. The acute toxicity effect of TBTO on T. suecica was obviously shown even at the concentration of 0.5 $\mu$g/L, and the effect diminished as the initial cell density increased. The effect also diminished less in the experiment done under aeration than in that done under non-aeration. To design a chemostat system for the test of chronic toxicity, the culture of T. suecica was executed in photobioreactor. In batch culture, the profiles of chlorophyII a and D.C.W. showed the growth of T. suecica very well, and the maximum specific growth rate was estimated to be 0.54 d$^{-1}$. with this value, as a dilution rate in contimuous culture, pH was nicely maintained between 7 and 9 when air was supplied with 3% CO$_{2}$. From all results and the natural environment of clam, a novel chemostat system was invented. Through this system, we can observe each independent toxicity effect of TBTO and plankton and combined toxicity effect as well.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
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• pp.156-161
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• 1998

As grouting materials for ground improvement, silicate materials such as water glass, silica-sol and so forth are used worldwide. However, they may pollute underground water. In this study, fish poison test(Korean standard industrial code KS M 0111) which estimates toxicity for fish is applied to evaluate the toxic effect by grouting materials. From the test result of the sample made of LW, LC50(Median Lethal Concentration) reaches within 24 hours. In case of the silica-sol, it does not even in 96 hours. Therefore, we can conclude that the sililca-sol grouting method is more free from the danger of underground water pollution. From the result that the mortality of fish under the condition of pH 8.6 is 0% within 96 hours, the groundwater can be saved by controlling pH below 8.6 for the grouting in the field.

• 한국동물학회지
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• 제20권3호
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• pp.149-157
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• 1977

현재 약 40종의 유전인자가 Mexican axolotl에 알려져 있다. 이 유전인자 들은 모두 열성인자로서 발생에 미치는 영향과 시기에 따라 5군으로 분류되었다. 즉, 난자형성에 영향을 미치는 유전자군(maternal-effect gene), 인의 크기에 영향을 미치는군, 특수 조직이나 기관발생에 영향을 미치는군, 모든 세포와 조직에 치사 작용을하는 유전자군(autonomous lethals), 그리고 색소세포에 영향을 미치는 유전자군들이다. 본 논문은 이 유전자들의 표현형과 현재 추구되고 있는 실험방법들에 대하여 간단히 소개하였다.

• 환경생물
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• 제31권4호
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• pp.376-382
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• 2013

[6]-Gingerol, a major polyphenol of ginger (Zingiber officinale), exhibits a variety of biological properties including anti-oxidant, anti-inflammatory and anti-cancer activity. However, the radioprotective effect of [6]-gingerol is still unknown. The aim of this study was to investigate the radioprotective effect of [6]-gingerol against radiation-induced cell cytotoxicity and oxidative stress in HepG2 cells. [6]-Gingerol pretreatment attenuated radiation-induced cell cytotoxicity caused by 5Gy (half lethal dose, $LD_{50}$ of HepG2 cells). The measurements of superoxide dismutase (SOD) and catalase (CAT) activity were also performed. The results showed that [6]-gingerol pretreatment reduced increasing SOD and CAT activity after exposure of IR, indicating that [6]-gingerol protected oxidative stress by regulating cellular antioxidant enzyme (SOD and CAT) activity. These findings suggest that [6]-gingerol acts as a radioprotector by attenuating cell cytotoxicity and oxidative stress.

• Fisheries and Aquatic Sciences
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• 제20권12호
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• pp.32.1-32.7
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• 2017

Recent in vitro studies have demonstrated that extract of soft coral Dendronephthya gigantea (SCDE) had strong anti-inflammatory activities. However, the direct effects of SCDE on anti-inflammatory activities in vivo model remained to be determined. Therefore, the present study was designed to assess in vivo anti-inflammatory effect of SCDE using lipopolysaccharide (LPS)-stimulated zebrafish model. We also investigated whether SCDE has toxic effects in zebrafish model. The survival, heart beat rate, and developmental abnormalities were no significant change in the zebrafish embryos exposed to at a concentration below $100{\mu}g/ml$ of SCDE. However, lethal toxicity was caused after exposure to 200 and $400{\mu}g/ml$ of SCDE. Treating zebrafish model with LPS treatment significantly increased the reactive oxygen species (ROS) and nitric oxide (NO) generation. However, SCDE inhibited this LPS-stimulated ROS and NO generation in a dose-dependent manner. These results show that SCDE alleviated inflammation by inhibiting the ROS and NO generation induced by LPS treatment. In addition, SCDE has a protective effect against the cell damage induced by LPS exposure in zebrafish embryos. This outcome could explain the profound anti-inflammatory effect of SCDE both in vitro as well as in vivo, suggesting that the SCDE might be a strong anti-inflammatory agent.

• 약학회지
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• 제41권1호
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• pp.99-104
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• 1997

In order to elucidate the cytotoxic effect of oxygen radicals on cultured spinal dorsal root ganglion(DRG) neurons derived from mouse. the neurotoxic effect of oxygen radicals w as examined after cultured DRG neurons were exposed to xanthine oxidase(XO) and hypoxanthine(HX)-oxygen radical generating system. In addition. neuroprotective effect of epidermal growth factor(EGF) against oxidant-induced neurotoxicity was also evaluated in these cultures. The results were, as follows: 1. Lethal concentration 50(LC$_{50}$) was 35mU/ml XO and 0.1mM HX in cultured DRG neurons. 2. Oxygen radicals induced the morphological changes such as the decrease of cell number and loss of neurites in these cultures. 3. EGF increased the cell viability and neurofilament in neurons damaged by oxygen radicals. From above the results, it is suggested that oxygen radicals have a cytotoxic effect on cultured DRG neurons of neonatal mouse and selective neurotrophic factors such as EGF are, effective, in blocking the neurotoxicity induced by oxygen radicals in cultured spinal DRG neurons.