• 한국작물학회지
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• 제34권s01호
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• pp.16-25
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• 1989

A bioassay is a test system using a living organism (in whole or in part) to determine the presence or relative potency of chemical substances. The development and uses of bioassay are intimately linked to the discovery and characterization of the major classes of plant hormones. An application of this relationship is helpful for understanding the concept of plant hormones as well as the use of bioassay. And plant bioassay have been development and employed not only for the discovery and characterization of the biological activity of plant growth regulators but also have served several important secondary roles. The ideal bioassay should possess the characteristic of high specificity. great sensitivity. short response time, low cost and ease of obtaining plant material. acceptable ease of manipulation, and minimal space and equipment requirements.

• The Korean Journal of Physiology and Pharmacology
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• 제10권6호
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• pp.349-354
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• 2006

The aromatic hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates many of the biological and toxicological effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) and related chemicals. The application of recombinant reporter plasmid such as the firefly luciferase gene has proven to be a very effective method to detect these chemicals. The bioassay system, CALUX, is sensitive in directly detecting AhR-agonists from a variety of environmental and biologic materials. However, responses of the AhR-dependent bioassays are dependent on the cell types used. Thus, we developed a sensitive bioassay using the recombinant mouse hepatoma cell (Hepa1c1c7) for the determination of dioxins. The recombinant cell line was stably transfected with firefly luciferase reporter gene (pGudLuc1.1). The transfected cells showed the highest induction of luciferase activity at 4.5 hr and a decrease beyond this time point. The system showed the highest sensitivity of detection ever reported. Upon TCDD exposure cells showed 2 fold increase at 10 pM and 7 fold increase at 100 pM, respectively. The passage number after the transfection played an important role in the sensitivity. The increase of passage number tended to increase the sensitivity of the cells up to 15. The media without phenol red showed a higher induction rate than with phenol red, suggesting the preferable use of phenol red-free media for the bioassay. Since each of the assays has unique characteristics that make them suitable for some screening applications and not others, development of sensitive bioanalytical methods based on a variety of cellular systems in a key to the successful determination of dioxins. The bioassay system developed in this study will contribute to further development of successful screening the AhR agonists among the environmental mixture. In addition, the rapid and sensitive nature of this cellular system can be applied as a valuable tool to screen the dioxin-like moieties among the prodrugs at the initial stage, thereby expediting the new drug discovery.

• 한국환경성돌연변이발암원학회지
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• 제24권3호
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• pp.137-142
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• 2004

Dioxin-like compounds are ubiquitous environmental polltants that could be accumulated in biological system and toxic to human and wildlife. Given this issue, it is important to develop a reliable dioxin detection methods for a rational risk assesment of dioxin-like compounds. In this study, we tried to set up and validate a sensitive, reliable risk assessment of dioxin-like compounds. In this study, we tried to set up and validate a sensitive, reliable and rapid bioassay model, CALUX bioassay as a screening tool for routine measurement of dioxin-like conpounds in environmental matrices. For the valisation of CALUX bioassay, firstly, we performed dose-response assay for 2,3,7,8-TCDD, most potent dioxin-like compound, using two different methods CALUX and EROD assay. Induction of luciferase activity and CYPIA catalyzed EROD activity were dose-dependently induced by 2,3,7,8-TCDD, with initial induction at 0.1 pM and maximal induction at 1 nM. In order t determine whether the CALUX bioassay could predict the effects of dioxin-like compounds, 2,3,7,8-TCDD dose-response from CALUX was compared with that from EROD assay. The correlation coefficient ($r^2$) was found to be 0.89, indicating a good correlation between two different methods and the possibility of CALUX bioassay as a useful dioxin detecting method.

• 한국응용곤충학회지
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• 제31권4호
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• pp.452-460
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• 1992

신규 살충성화합물의 개발을 위한 생물검정법 확립의 일환으로 수종의 곤충을 이용하여 침지시간, 약제처리 방법, 공시충의 종간 및 발육태에 따른 살충제의 감수성을 조사하였다. 침지시간, 처리방법, 공시충의 종간 및 발육태에 따라 살충력에 현저한 차이를 보였는데, 침지시간은 엽침지법에서 약 30~60초 침지처리에서 효과가 좋았으며 60초 이상 침지처리에서는 식물체의 내용물이 용출되어 바람직하지 않았다. 처리방법은 콩진딧물과 복숭아혹진딧물 무시암컷, 배추좀나방과 담배거세미나방 3령유충은 엽침지법, 벼멸구 3령약충 또는 성충과 벼유묘 동시분무법, 점박이응애는 엽침지법 또는 분무법이 효과적인 처리방법이었다. 키틴합성저해제의 검정은 벼멸구의 경우 3령약충, 배추좀나방과 담배거세미나방 3령유충, 진딧물류 3령약충 및 점박이응애 유충을 약제가 분무처리된 유묘에 접종하여 검정하는 방법이 적합하였다.

• The Korean Journal of Physiology and Pharmacology
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• 제2권2호
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• pp.209-216
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• 1998

The present study was designed: (1) to determine whether or not hypoxia stimulates the release of endothelium-derived relaxing factors (EDRFs) from endothelial cells, and (2) to examine whether or not the hypoxia-induced EDRFs release is further augmented by previous hypoxia-reoxygenation, using bioassay system. In the bioassay experiment, rabbit aorta with endothelium was used as EDRFs donor vessel and rabbit carotid artery without endothelium as a bioassay test ring. The test ring was contracted by prostaglandin $F_{2{\alpha}}$ $(3{\times}10^{-6}\;M/L)$, which was added to the solution perfusing through the aortic segment. Hypoxia was evoked by switching the solution aerated with 95% $O_2/5%\;CO_2$ mixed gas to one aerated with 95% $N_2/5%\;CO_2$ mixed gas. When the contraction induced by prostaglandin $F_{2{\alpha}}$ reached a steady state, the solution was exchanged for hypoxic one. And then, hypoxia and reoxygenation were interchanged at intervals of 2 minutes (intermittent hypoxia). The endothelial cells were also exposed to single 10-minute hypoxia (continuous hypoxia). When the bioassay ring was superfused with the perfusate through intact aorta, hypoxia relaxed the precontracted bioassay test ring markedly. Whereas, when bioassay ring was superfused with the perfusate through denuded aorta or polyethylene tubing, hypoxia relaxed the precontracted ring slightly. The relaxation was not inhibited by indomethacin but by nitro-L-arginine or methylene blue. The hypoxia-induced relaxation was further augmented by previous hypoxia-reoxygenation and the magnitude of the relaxation by intermittent hypoxia was significantly greater than that of the relaxation by continuous hypoxia. The results suggest that hypoxia stimulates EDNO release from endothelial cells and that the hypoxia-induced EDNO release is further augmented by previous hypoxia-reoxygenation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권3호
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• pp.186-192
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• 2004

Purpose: Human tooth proteins are highly heterogeneous, comprising diverse proteins derived from a number of genes. The attempts to identify protein for activity of tooth matrix proteins have been defied by several factors. First, the amount of proteins within teeth is very small relative to many extracellular matrix proteins of other tissues. Second, the bioassay system is tedious and needed for long time. Therefore we tried to find easy techniques, which increase the product rate, and an assay of small proteins, with which amino acid sequence is possible without additional procedures. Materials and Methods: Total protein were extracted from 300 g enamel removed teeth and 600 g teeth with 4 mol/L guanidine HCl and purified by gel chromatography. Aliquot of proteins was implanted into muscle pouches in Sprague-Dawley rats for bioassay. By SDS-PAGE and membrane blotting, molecular weight of each protein was estimated and a partial amino acid sequence was obtained. Each fraction blotted on the membrane was cut out and inserted in rat ectopic model. Results: In dissociative method, total tooth proteins were obtained 1mg/ml from enamel removed teeth and 3.5 mg/ml from teeth. In SDS-PAGE, four clear bands at the sites corresponding to 66, 40, 20 and 18 kD. Especially The 66 kD band was clearly exhibited. Amino acid sequencing from tooth could be possible using PVDF membrane blotting technique. In amino acid sequencing, 66 kD protein was identified as albumin. Conclusion: Compared with conventional method for extraction of teeth protein and bioassay of proteins, the methods in this study were easy, time-saving and more productive technique. The matured tooth proteins omitting additional procedure of mechanical removal of enamel were simply analyzed using blotted PVDF membrane. This method seems to make a contribution as a technique for bioassay and amino acid sequencing of protein.

• 한국패류학회지
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• 제21권1호
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• pp.25-31
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• 2005

The embryos of marine bivalves have been commonly used in bioassays for the quality assessment of marine environments. Although several standard protocols for developmental bioassay with bivalves have been already proposed, there have been few trials for applying these protocols in environmental assessment, or for developing new protocol with Korean species. So, there is a strong need to establish the standard bioassay protocols using bivalves commonly found in Korean waters. Prior to developing a new protocol, it is essential to know the optimum conditions for the reliable bioassay procedures. Here, we established the purpose of this study to determine the optimum bioassay conditions for successful development of a common mussel, Mytilus galloprovincialis. The conditions considered as critical for developmental bioassay, and determined in this study were; (1) temperature, (2) salinity, and (3) initial density of embryo. The optimal temperature for developmental bioassay of M. galloprovincialis was determined as $15^{\circ}C$. At this temperature, the required time for the embryo to become veliger larva was 48 hr. The acceptable range of salinity for the embryotoxicity test using M. galloprivincialis was from 30 to 35 psu, which was narrower than that of the natural habitat of adult populations. The optimum density of embryo at the beginning of bioassay was 100 embryos/ml. Over this density, the proportion of normally developed larvae decreased significantly. The results obtained in this study will serve as a basis for preparation of the standard bioassay protocol using embryo of M. galloprovincialis.

• Environmental Analysis Health and Toxicology
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• 제22권1호
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• pp.27-36
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• 2007

Cyanides and dichlorophenols were important pollutants in industrial effluents of steel, petroleum, plastics, pesticides, synthetic dye and/or fiber manufacturing. The toxic effects of cyanide and 3, 5-dichlorophenol in the unary and binary solutions to Vibrio fischeri were determined using the newly developed $N-tox^{(R)}$ bioassay system. This bioassay system relies upon the attenuation of light intensity emitted by Vibrio fischeri exposed to various pollutants including metals and organic compounds. Most of studies dealing with toxicity of pollutants concerned single chemical species, while the organisms were typically exposed to pollutant mixtures. The present study showed that the toxicity of some binary combinations of cyanide and 3, 5-dichlorophenol significantly was lower than the predicted toxicity from the addicted model. This antagonistic interaction was well explained by chemical interaction model presented in this study.

• Environmental Analysis Health and Toxicology
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• 제25권1호
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• pp.19-26
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• 2010

Discharged materials from the point or non-point source are released into the sea, and as the results, marine environment is directly affected. We must estimate the impacts of contaminants to marine pollution rapidly and accurately. Therefore, it is needed on early warning system for appreciating marine environmental impacts, and required a bioassay to evaluate abnormal changes. A bioassay test was developed to examine the effects of heavy metal contaminants on the early life stages of the marine annimals. We have studied the effects of metals on early development of a sea urchin species, Strongylocentrotus intermedius. S. intermedius embryos were tested with six metals (Cu, Ag, Zn, Cd, Cr, Ni) and showed the highest sensitivity to Cu as well as the lowest sensitivity to Cd. The order of biological impact for metals was Cu>Ag>Ni>Zn>Cr>Cd. In accordance with the results, sea urchins embryos can provide biological criteria for seawater quality assessment. The sensitivity of developmental bioassay whith S. intermedius is at intermediate level among marine organisms commonly used in aquatic bioassays. And this sea urchin can be routinely employed as a test organism for ecotoxicity assays.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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• pp.201-201
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• 2001

Transforming growth factor- $\beta$ (TGF- $\beta$), a hormonally active polypeptide found in normal and transformed tissue, is a potent regulator of cell growth and differentiation. In this study, we wished to establish an in vitro bioassay system to seek the most sensitive method that can measure TGF- $\beta$ activity.(omitted)