• The Korean Journal of Nuclear Medicine
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• v.9 no.2
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• pp.39-46
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• 1975

It is the purpose of this paper to design the most preferable method of erythropoietin bioassay in Korea. Bioassay utilizing polycythemic mice are currently in general use for the indirect determination of erythropoietin. Assay animals are usually prepared either by transfusion or by exposure to reduced oxygen tension in specially constructed chamber. We prepared the polycythemic, mice by the specially constructed hypobaric chamber. We observed weights and hematocrits of the mice in the hypobaric chamber, then hematocrits and 72 hours $^{59}Fe$ red cell upatke ratio of the polycythemic mice induced by hypoxia after removal from the hypobaric chamber. We designed the method of erythropoietin bioassay according to the results obtained by above experiments. Then we measured the 72 hours $^{59}Fe$ red cell uptake ratio of the polycythemic mice with normal saline, normal plasma and anemic plasma according to the method we designed. The results are followed: 1. The hematocrits of the mice in hypobaric chamber increased to 74% in 14 days It is preferable to maintain the pressure of the chamber to 400mmHg for first 4 days then 300mmHg for last 10 days to reduce the death rate and time consuming in hypobaric chamber. 2. After removal from the hypobaric chamber, the 72 hours $^{59}Fe$ red cell uptake ratio decreased rapidly and maintained the lowest level from the fourth day to tenth day. 3. We design the method of erythropoietin bioassay according to the results of above experiment and to the half life of erythropoietin. 4. The Korean product S9Fe is mixture of $^{59}Fe\;and\;^{55}Fe$. And the $^{59}Fe$ red cell uptake ratio in normal mice was far less with Korean product $^{59}Fe$ than with pure $^{59}Fe$ of foreign product. So it is desirable to use pure $^{59}Fe$ in this method of erythropoietin bioassay. 5. Considering the cost, the technique, the time consuming and the sensitivity it is the most preferable method of erythropoietin bioassay in Korea using hypobaric chamber to induce the polycythemia.

• Environmental Analysis Health and Toxicology
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• v.25 no.1
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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.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.40-40
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• 2017

Rice (Oryza sativa L.) is one of major crops of Vietnam. Rice plant contains many secondary metabolites that are potent to inhibit growth of other plants. This study was carried out to find potential plant growth inhibitors from rice plants. Seven rice varieties were cultivated in the fields affiliated to Hiroshima University, Japan; Mature stems and leaves from each variety were collected, and then they were extracted with methanol, hexane, ethyl acetate, butanol, and water. Total phenolic content and total flavonoid content were the highest in ethyl acetate extract. DPPH antioxidant assay results showed that the ethyl acetate extract also had higher $IC_{50}$ value. Therefore, the ethyl acetate extracts were selected for laboratory bioassay. Results showed that the two-local variety Re nuoc and Nan chon inhibited the germination of radish and barnyard grass seedlings at the greatest levels, as compared to other cultivars. HPLC quantification indicated that the ethyl acetate extracts of Re nuoc and Nan chon rice plant parts consists of phenolic and flavonoids compounds which are potent as plant growth inhibitors. Further laboratory bioassay and field experimentation will be conducted to validate the laboratory bioassay findings.

• Korean Journal of Veterinary Service
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• v.28 no.3
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• pp.235-243
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• 2005

This surveies were carried out to investigate the residual levels of fluoroquinolones in chicken and quail eggs by bioassay and HPLC method. The eggs of 240 samples collected from market and farm in Gwangju Metropolitan city were examined from May to December in 2003. Residual antibiotic materials were detected from 47 samples of the 240 eggs by bioassay. Of the 240 eggs assayed, ciprofloxacin, danofloxacin, norfloxacin, ofloxacin, orbifloxacin and perfloxacin were not detected but enrofloxacin was detected from 5 samples in 228 chicken eggs and 1 sample in 12 quail eggs using HPLC with fluorescence detector by multi-residue method. 2 sample eggs in 6 sample which were detected by HPLC were not positive with bioassay. The average residual concentration of enrofloxacin was 0.494 mg/kg in 6 positive samples. The highest residual concentration of enrofloxacin was 1.83mg/kg.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.4
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• pp.309-316
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• 2001

Helianthus tuberosus has been known to inhibit the growth of weeds and other plants sharing its habitat. This study was conducted to identify the allelochemicals of Helianthus tuberosus which were extracted with water and solvents. Aqueous extracts of leaf, stem, root, tuber and tuber peel of Helianthus tuberosus except tuber did not show significant differences in phytotoxicity to alfalfa seedlings. It was considered that Helianthus tuberosus contained fewer or less potential water-soluble substances that were toxic to alfalfa. Methanol extract of leaves of Helianthus tuberosus was sequentially partitioned in increasing polarity with n-hexane, ethylacetate and n-butanol. Each extract had a yield of 148, 12, 15.7 and 9.5g, respectively. Inhibitory effects on germination of alfalfa seeds treated with four fractions were not significantly different. But the significant reductions on hypocotyl length were observed for all the solvent extracts. Among the four fractions, the ethylacetate fraction showed the most significant inhibition effect on bioassay with alfalfa. Further separation of the active ethylacetate fraction by open column chromatography led to the 25 subfractions. In bioassay of each sub-fraction with alfalfa seeds, sub-fraction No. 13 showed the most inhibitory effect on seedling growth. $^1$H NMR and gas chromatography-mass spectrometry analysis revealed that sub-fraction No. 13 was the mixture of straight-chain saturated fatty acids.

• Korean journal of applied entomology
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• v.60 no.2
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• pp.201-202
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• 2021

We confirmed the convenient bioassay method for the black cutworm, Agrotis ipsilon in semi-field conditions. And we surveyed the susceptibility to commercial pesticides of A. ipsilon, which feeds Chinese cabbage through this bioassay process. As a result of the test, six soil mixing insecticides and eight soil drenching insecticides showed more than 90% insecticidal activity.

• Korean Journal of Weed Science
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• v.31 no.3
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• pp.271-278
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• 2011

The allelopathic effects of Lantana camara L. (Family:Verbenaceae) on germination and seedling establishment of some agricultural crops and weed species have been identified. Aqueous extracts of dry leaves and contaminated soil where L. camara is grown were used to verify allelopathic effect on seed germination of five bioassay species; Raphanus sativas, Capsicum annum, Lycopersicum esculantem, Crotalaria juncia and Chromoleana odorata. Fifty seeds from each bioassay species were placed in a petri dish containing leaf extracts or contaminated soil, and seed germination were examined after 3 days. The plant house experiments were carried out to evaluate the impact of L. camara contaminated soil and leaf debris using L. esculantem as the indicator plant. Seed germination of L. esculentem, C. junica and Capsicum annum was significantly inhibited by L. camara contaminated soil. However, the degree of inhibition varied among the bioassay species. The aqueous extract of dry leaves of L. camara was highly phytotoxic and it significantly reduced seed germination of all bioassay species. There was a decline in plant height, leaf area and shoot dry weight of tomato only in early growth stages when grown in L. camara contaminated soils. However, incorporation of leaf debris into soil affected the vegetative growth of tomato in early stages when the leaf debris concentration was increased. Growth recovered at the latter part of the life cycle. On the basis of these results it can be concluded that the allelochemicals in L. camara contaminated soils are harmful to the seed germination of crop species. The adverse effect was present only during the early growth stages and it did not suppress the latter part of the plant growth. These responses are attributed to allelopathic effects which need confirmation under field conditions.

• Korean journal of applied entomology
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• v.31 no.4
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• pp.452-460
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• 1992

To establish the economical and reliable routine bioassay system for developing new insecticidal compounds, effects of leaf-dipping time, application methods, insect species and their developmental stages on susceptibilities of insects to insecticides were studied. The stable insecticidal activity appeared at the dipping time for 30-60 seconds in leaf-dipping method, and the most effective application methods were leaf-dipping method for apterous green peach aphid adults, and third instars of diamond-back moth and tobacco cutworm, whereas seedling+insect spray method for adults or third instars of brown planthoppers. For two-spotted spider mite, leaf-dipping or intact plant spray method was favorable. In the bioassay for chitin synthesis inhibitors, the inoculation of third instars of brown planthopper, diamond-back moth, tobacco cutworm and green peach aphid, and larvae of two-spotted spider mite to the young host plants treated by spray method were adequate bioassay methods.

• Environmental Analysis Health and Toxicology
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• v.22 no.3
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• pp.211-218
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• 2007

Even though some standard developmental bioassay protocols for environmental assessment using sea urchins have already been described, there have not been many attempts to apply and modify these protocols with Korean species. Therefore, there is a strong need to establish standard bioassay protocols using sea urchins commonly found in Korea. Prior to developing a new protocol, it is essential to know the optimal conditions for the bioassay procedures. We investigated the optimal conditions (temperature, salinity, and embryo density) of the sea urchin Strongylocentrotus intermedius. The ideal temperature for developmental bioassay of S. intermedius was determined to be $15^{\circ}C$ and the time required for the embryo to become pluteus larva was 72 hr. The optimal range of salinity for the embryo toxicity using S. intermedius was between 30 to 32 psu, which is similar to the range found in the natural habitats of adult populations. The optimum density of embryos at the beginning of bioassays was 100 embryos/mL. When the assays were carried out at higher densities, the proportion of normally developed larvae decreased significantly.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.4
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• pp.382-390
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• 2018

The history of the pregnancy test started in ancient Egypt with a germination test using wheat and barley. Since then, unscientific methods have been used from the days of Hippocrates and Galen to the Middle Ages when uroscopy was used, even until the early 1800s. On the other hand, since the mid-1800s, scientific methods and evidence have begun to emerge, which led to scientific research on the physiological characteristics of pregnancy. The first attempt to utilize these scientific findings was initiated with the bioassay by Aschheim and Zondek using rats and mice in 1927, and then developed into experiments using rabbits and frogs. The immunoassay method, which started in the 1960s, contributed greatly to the generalization of the pregnancy tests while improving the problems of the bioassay. In 1976, a pregnancy test kit was introduced that can be used at home, contributing to the popularization of pregnancy tests. Since the 1980s, technological advances in diagnostic tests have also been applied to pregnancy tests to further improve the reliability of the diagnosis of pregnancy. In the 2000s, the accuracy and ease of use of the pregnancy test kits for home use have improved drastically. This study examined the history and scientific development of the pregnancy test.