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Toggle유전자 발현과 환경 독성 번역에 대해서 알아 보겠습니다(한영번역)
유전자 발현과 환경 독성 번역(한국어 원본)ABSTRACT. Introduction MATERIALS and METHODS CP는 sigma-aldrich에서 구매하였고, PDMS는 ~~에서 주문하였다. 이는 높이 11mm, 길이는 XX와 109mm로 24well과 6well의 내경에 두를수 있도록 두가지 size로 각각 cut하였고, 이 PDMS의 mass는 각각 0.5611, 1.3179g (n=30, standard deviation [SD] =0.0138g, 0.0243g)으로 측정되었다. 실험시 spiking을 하기 위해서는 DMSO를 solvent로 사용하여 stock을 제조하였으며, media에 투입된 solvent의 양은 전체 노출 media에 0.1%가 되도록 사용하였다. Passive dosing method을 이용한 독성 실험을 위해서는 CP를 loading한 PDMS를 노출 plate에 장착하여 미디어 내로 의도한 CP가 release되도록 하여야한다. 이러한 과정은 노출 system이 평형상태일때, PDMS와 미디어 사이의 mass balance 식으로 아래와 같이 표현할 수 있다. 미디어 총 노출 볼륨은 24well plate에 1ml, 6well plate에 10ml로 차등을 두어 실시하였으며, 노출 worm은E-tube에 pooling후 1~2분 간격을 두어 worm이 가라앉은 뒤 100ul 볼륨을 기준으로 총 노출 organism양을 결정하였다. Chlorpyrifos노출 농도는 0.3mg/L으로 하였으며(CP의 20도 기준으로 water solubility는 ~~이다.), spiking method를 사용한 실험은 worm이 들어있는 media에 spiking하여 바로 실험을 진행하였고, Passive dosing방법을 사용한 실험은 loading된 PDMS를 plate에 장착하여 24시간동안 분배평형이 이루어지도록 둔뒤, worm을 노출시켰다. 노출실험은 20도 에서 24시간 incubation하며 실시하였다. 이후 passive dosing method의 노출농도는 0.3mg/L로부터 1/2, 1/5, 1/10수준의 농도로 변화하며 실시하였으며, 노출시간은 실험 시작 후 2시간 간격으로 8시간까지 실시하였다. 노출 media내의 CP농도는 PDMS로 재 추출하여 분석하였다. 1ml의 노출 media를 vial에 옮긴뒤 직경 ~mm에 해당하는 disc PDMS를 넣어 24시간동안 150rpm으로 25도에서 shaking하며 PDMS내로 CP를 추출한뒤 disc PDMS를 동량의 Ethyl acetate로 치환하여 동일한 조건에서 24시간을 두어 역 추출을 실시하였다. 이를 GC로 분석하였으며, 추출 오차를 위한 recovery test는 3개의 농도에서 10회씩 실시하여 검증하였다. |
유전자 발현과 환경 독성 번역(영어 번역본)ABSTRACT In order to apply sensitive molecular-level biomarkers to the evaluation of environmental risks, it is necessary to establish a quantitative relationship between dose and response. Recently, passive dosing is thought to be a promising new technique that provides a constant exposure condition of hydrophobic contaminants in the assay medium. The main goals of the present study were 1) to provide a quantitative comparison of the gene expression results obtained from the passive dosing method and the conventional spiking method and 2) to investigate the changes in gene expression with respect to the freely dissolved concentration and the exposure duration using passive dosing. Chlorpyrifos (CP), which is known to be oxidized by the CYP450 monooxygenases, was selected as the target chemical, and Caenorhabditis elegans cytochrome p450 family protein 35A gene series (cyp35a1-5) was analyzed. Freely dissolved concentration of CP rapidly decreased when spiking method was used, and the expression patterns of cyp family genes varied greatly with total volume of exposure media and exposure time. In contrast, freely dissolved concentration of CP provided to C. elegans was stable until the end of exposure experiment when passive dosing method was used, and gene expression linearly increased with time. When the constantly maintained concentration of CP was lowered, slope of the linearly increasing trend was significantly reduced. The increased gene expression with increasing body residue concentration of CP in accordance with the accumulation of CP in C. elegans may explain the observed effects at low concentration. In conclusion, quantitative dose-response relationships for gene expression biomarkers could be derived when constant exposure condition is provided and freely dissolved concentration is used as the dose-metric. INTRODUCTION It has been asserted that gene expression has the potential to be a very sensitive and important end point for evaluation of environmental risks and monitoring of environmental toxicity. The basis for this argument is that gene expression reflects the initial toxicity response under low-concentration exposure prior to the development of toxicological effect at the level of an individual organism (survival, behavior, reproduction, etc.), which is a higher level of biological response [REF]. Due to such high sensitivity, dose-response relationship between exposure concentration and duration must be clearly delineated in a quantifiable manner for gene expression to be used as an end point for this purpose. Currently, most gene expression studies, even those with well-defined exposure conditions, denote exposure concentration as the nominal concentration of the initial exposure concentration. However, the initial nominal aqueous concentration rapidly decreases due to adsorption to the exposure plate wall, binding to components in the media, or evaporation. In reality, it is the freely dissolved concentration that is directly related to the response of the target organism. From these considerations, it is apparent that an exposure environment that can provide sustained level of clearly defined freely dissolved toxin concentration is very important for toxicological research. MATERIALS and METHODS C. elegans was cultured in NGM media at 20 °C while feeding on OP50. C. elegans young adults (3 days old) obtained from age-synchronized culture were used for all experiments, and k-media was used for aqueous exposure. CP was purchased from Sigma-Aldrich and PDMS was purchased from XXX. It was cut into height of 11 mm and length of either XX or 109 mm to fit the wells of 24-well and 6-well plate, respectively. Mass of the PDMS were measured to be 0.5611 g and 1.3179 g (n=30, standard deviation [SD] = 0.0138g, 0.0243g). For the spiking method, dimethyl sulfoxide (DMSO) was used to dissolve CP in the stock solution, and the amount of DMSO used was set to be less than 0.1% of the total exposure media. For toxicological test using passive dosing method, PDMS loading the CP must be equipped to the exposure plate and release CP into the media. Assuming the exposure system is at equilibrium, this process may be expressed by the mass balance equation between PDMS and the media. Total media exposure volumes were 1 mL for the 24-well plate and 10 mL for the 6-well plate. For exposure of worms, the worms were pooled in E-tubes, and after 1~2 minutes to allow the worms to settle to the bottom, the amount of total exposure organism was determined with respect to 100 uL volume. Exposure concentration of chlorpyrifos was set to be 0.3 mg/L (water solubility of CP is XXX mg/L at 20 °C). For spiking method, stock solution was spiked into the medium containing the worm. For passive dosing method, loaded PDMS was attached to the plate and incubated for 24 hours to reach equilibrium before exposing the worms. The worms were incubated in respective medium for 24 hours at 20 °C. Exposure concentration of passive dosing method was varied from 0.3 mg/L to 0.15 mg/L, 0.06 mg/L, and 0.03 mg/L, while exposure time points were taken from beginning of the experiment until 8 hours in 2 hour intervals. Concentration of CP within the exposure medium was re-extracted by PDMS for analysis. 1 mL of the exposure medium was transferred to a vial, and disc PDMS with diameter of XX mm was added. The vial was shaken at 150 rpm at 25 °C for 24 hours. Next, CP inside the PDMS was extracted and disc PDMS was replaced by the same amount of ethyl acetate for reverse extraction under same conditions for 24 hours. The sample was analyzed using gas chromatography, and recovery test for extraction error was conducted for 10 times for each of the three concentrations. |
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이상 국립독성연구원에서 의뢰한 유전자 발현과 환경 독성 번역(한영번역)의 일부를 살펴 보았습니다.
번역은 기버 번역