• Environmental Analysis Health and Toxicology
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• v.19 no.1
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• pp.25-32
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• 2004

Aim of the present study was the development of a bioassay which enables the detection of toxic effects of heavy metal ions to a bacterium, Escherichia coli. Inhibition effects of the metals on growth rates of the bacterium were studied in the absence or presence of fulvic acid. This method does not clearly differentiate among metals, but does detect overall AGB inhibition rate (toxicity) for 5 different heavy metals. The toxicity of the metals in the absence of fulvic acid in the same testing conditions was significantly increased in following order: Hg < Pb, Zn < Cd < Cu, whereas the inhibition rate (toxicity) in the presence of FA was shown to be increased In following order: Cd < Pb, Hg < Cu < Zn. The results of the present study indicate that this simple and fast biomonitoring assay with direct exposure of E coli. might be a valuable supplement to analytical methods of contaminated media.

• Korean Journal of Plant Tissue Culture
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• v.25 no.2
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• pp.95-98
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• 1998

Hypocotyl explants of flowering cabbage were cocultured with Agrobacterium tumefaciens LBA4404;;pGA875 harboring proteinase inhibitor II(PI-II) cDNA and then regenerated into plants. Sucessful transcripts of PI-II gene were detected by RNA dot blot analysis. Bioassay was conducted on transgenic flowering cabbage. It was confirmed that insecticidal activities of transformants were much higer than that of control plants. In progeny test of hansformants, 27.4% of T$_1$ seeds was resistant on MS medium containing 20 mg/L kanamycin.

• Archives of Pharmacal Research
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• v.17 no.5
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• pp.331-336
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• 1994

The ether extract from the roots of angelica clahurica was found to inhibit bovine lens aldose reductase (BLAR0 activity in vitro by 100% at 100.mu.g/ml. Systematic fractionation of the ether soluble fraction and subsequent active frctions monitorede by bioassy led to isolation of four furanocoumarins, isoimperatorin (I0, imperatorin (II), ter-O-methyl byakangelicin (III) and byakangelicin (IV), among which compound III and IV were identified as potential AR inhibitors, their $IC_{50}$ values being $2.8{\mu}M{\;}and{\;}6.2{\mu}M$, respectively. Galactosemic cataract formation tors, in rats treated with 40 g/kg/day of galactose was blocked almost completely throughout the exeprimental periods up to 44 days by i.p. administrations of byakangelicin (IV) at 50 mg/kg/day. In coincidence with the inhibitory action on cataract formation, the galactitol accumulation in rats treated with byakangelicin (IV) was found to be markedly prevented by approximately 80.5% compared to those of the contro. These results indicate that byakangelicin (IV), as a main principle of this plant, possesses high potential for a clinically useful drug of the future which prevents and/or improves sugar cataract as well as diabetic complications.

• Journal of Preventive Medicine and Public Health
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• v.29 no.1 s.52
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• pp.27-41
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• 1996

This study described methods to predict human health risk associated with exposure to environmental carcinogens using animal bioassay data. Also, biological assumption for various dose-response models were reviewed. To illustrate the process of risk estimate using relevant dose-response models such as Log-normal, Mantel-Bryan, Weibull and Multistage model, we used four animal carcinogenesis bioassy data of chloroform and chloroform concentrations of tap water measured in large cities of Korea from 1987 to 1995. As a result, in the case of using average concentration in exposure data and 95% upper boud unit risk of Multistge model, excess cancer risk(RISK I) was about $1.9\times10^{-6}$, in the case of using probability distribution of cumulative exposure data and unit risks, those risks(RISK II) which were simulated by Monte-Carlo analysis were about $2.4\times10^{-6}\;and\;7.9\times10^{-5}$ at 50 and 95 percentile, respectively. Therefore risk estimated by Monte-Carlo analysis using probability distribution of input variables may be more conservative.

• Korean journal of applied entomology
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• v.32 no.4
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• pp.426-432
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• 1993

Thirteen isolates of Bacillus thunngiensls producing parasporal mclusions, obtained from 45 samples of dust and soil of sericultural tarms in Kyeong-ki province, were exammed for their toxicity against larvae of Lepidoptera, Dipwra and Coleoptera. Of these isolates, Bacillus f thuringiensis NT0423 was toxic to bath Lepidoptera, and Dipteran larvae. NT0423 showed that the $LC_{50}$ values against the Lepldaptora, Plutella macuhpennis and the Diptera, Culex pipiens were $1.30\times10^6$ CFU/ml, $2.88\times10^5$ CFU/ml, respectively. The tYPlcal bipyramldal crystals produced by NT0423 composed of protoxms of 130-140kDa encoded by one or more plasm mid-horne genes. Also, plasmid DNA analysis indicated Lhat this isolate has 9 plasmids which d differ with reported several B. thuringiensis strains.

• Journal of Dairy Science and Biotechnology
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• v.14 no.2
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• pp.229-245
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• 1996

1. CM-Sephadex C-50-120 column을 사용하여 HLF를 효과적으로 정제하였다. CM-Sepha-dex 50-120 column chromatography를 수행한 결과, HLF는 NaCl 350 mM-500 mM 사이에서 용출되었으며, 용출된 분획을 SDS-PAGE를 수행해서 단일 band를 확인하였다. Anti-HLF antibody를 이용한 Western blotting 결과 nitrocellulose paper 상에 단일 band 가 나타나므로 HLF 가 효과적으로 정제되었다는 것을 알 수 있었다. 2. Con A, PWM, PWA LPS 등의 자극원으로 단핵구와 대식세포를 자극한 다음 BLF를처리한 배 양액을 IL-1 bioassy한 결과는 Con A 33%, PMA 33%, PWM 15%, LPS 35% 이고, HLF로 처리하여 IL-1 bioassay를 한 결과는 Con A 15%, PMA 22%, PWM 10%, LPS 5%로 감소된 것으로 나타났다. 3. K-562 세포를 이용한 colony forming assay에서 BLF가 10 g/ml일 때는 30%, 30 g/ml일 때는 35%, HLF는 10 g/ml일 때는 5%,30 g/ml일 때는 30%의 저해를 나타냈다. 4. Lactoferrin의 면역증강효과를 알아보기 위하여 hapten인 VCR-BSA를 투여 한 후, 생성되는 항체생성능력을 ELISA로 비교하였다. 그 결과 HLF 및 BLF 투여군에서 대조군에 비하여 adjuvant 효과를 관찰할 수 있었다. 또한 이때 macrophage 수는 대조군에 비하여 HLF와 BLF를 투여한 군이 증가됨을 알 수 있었다. 이러한 결과로 미루어 볼 때 LF는 macrophage를 활성화 시켜서 항체 생성 능력을 증가시키는 효과가 있음을 관찰할 수 있었다. 5. Balb/c mouse의 thymus로부터 분리한 CD4- CD8- 세포를 BLF로 처리하여 24 시간 배양한 후 CB4$^-$ CD8$^-$ 세포의 분화를 측정한 결과, CD4$^-$를 CD4$^+$ 로 분화하였다. 그리고 HLF로 처리하여 24 시간 배양 후 CD4$^-$ CD8$^-$ 세포의 분화를 측정한 결과, CD4$^-$ CD8$^-$를 CD4$^+$ CD8$^+$ 로 분화하였다. 6. Lactoferrin이 T cell의 IL-2 production에 미치는 영향은 PMA 처리군, PMA+OKT3처리군, LF 단독 처리군 보다 PMA+OKT3+LF를 처리한 군이 IL-2 생성에 영향을 미쳤다. 7. Lfcin B의 단일크론항체에 의해 인식되어지는 Lfcin B의 항원결정기는 ‘QWR’로 밝혀졌다.

• The Korean Journal of Mycology
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• v.25 no.1 s.80
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• pp.10-19
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• 1997

Fusarium wilt of radish (Raphanus sativus L.) is caused by the Fusarium oxysporum f. sp. raphani (FOR) which mainly attacks Raphanus spp. The pathogen is a soil-borne and forms chlamydospores in infected plant residues in soil. Infected pathogen colonizes the vascular tissue, leading to necrosis of the vascular tissue. Growth promoting beneficial organisms such as Pseudomonas fluorescens WCS374 (strain WCS374), P. putida RE10 (strain RE10) and Pseudomonas sp. EN415 (strain EN415) were used for microorganisms-mediated induction of systemic resistance in radish against Fusarium wilt. In this bioassy, the pathogens and bacteria were treated into soil separately or concurrently, and mixed the bacteria with the different level of combination. Significant suppression of the disease by bacterial treatments was generally observed in pot bioassy. The disease incidence of the control recorded 46.5% in the internal observation and 21.1% in the external observation, respectively. The disease incidence of P. putida RE10 recorded 12.2% in the internal observation and 7.8% in the external observation, respectively. However, the disease incidence of P. fluorescens WCS374 which was proved to be highly suppressive to Fusarium wilt indicated 45.6% in the internal observation and 27.8% in the external observation, respectively. The disease incidence of P. putida RE10 mixed with P. fluorescens WCS374 or Pseudomonas sp. EN415 was in the range of 10.0-22.1%. On the other hand, the disease incidence of P. putida RE10 mixed with Pseudomonas sp. EN415 was in the range of 7.8-20.2%. The colonization by FOR was observed in the range of $2.4-5.1{\times}10^3/g$ on the root surface and $0.7-1.3{\times}10^3/g$ in the soil, but the numbers were not statistically different. As compared with $3.8{\times}10^3/g$ root of the control, the colonization of infested ROR indicated $2.9{\times}10^3/g$ root in separate treatments of P. putida RE10, and less than $3.8{\times}10^3/g$ root of the control. Also, the colonization of FOR recorded $5.1{\times}10^3/g$ root in mixed treatments of 3 bacterial strains such as P. putida RE10, P. fluorescens WCS374 and Pseudomonas sp. EN415. The colonization of FOR in soil was less than that of FOR in root part. Based on soil or root part, the colonization of ROR didn't indicate a significant difference. The colonization of introduced 3 fluorescent pseudomonads was observed in the range of $2.3-4.0{\times}10^7/g$ in the root surface and $0.9-1.8{\times}10^7/g$ in soil, but the bacterial densities were significantly different. When growth promoting organisms were introduced into the soil, the population of Pseudomonas sp. in the root part treated with P. putida RE10 was similar in number to the control and recorded the low numerical value as compared with any other treatments. The population density of Pseudomonas sp. in the treatment of P. putida RE10 indicated significant differences in the root part, but didn't show significant differences in soil. The population densities of infested FOR and introduced bacteria on the root were high in contrast to those of soil. P. putida RE10 and Pseudomonas sp. EN415 used in this experiment appeared to induce the resistance of the host against Fusarium wilt.

• Korean Journal of Weed Science
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• v.18 no.4
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• pp.295-303
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• 1998

The seed dormancy is one of the peculiar characteristics of a number of weed species and it makes difficulties in weed control. To clarify the mechanism of seed dormancy, several chemicals such as $KNO_3$, KOH, thiourea, and $H_2O_2$ and phytohormone($GA_3$) were treated to dormant seeds. Among the species treated with several chemicals, the germination percentages of Setaria glauca, Ambrosia trifida and Ranunculus sceleratus were increased with $KNO_3$ and those of S. glauca, R sceleratus were increased with thiourea. Hydrogen peroxide promoted the germination of Setaria viridis and S. glauca. Germination percentages of S. viridis, S. glauca and Cyperus saraguinolentus were increased with enzyme treatment using pectinase. GA treatment enhanced the geim.ination of Eleusine indica and R sceleratus but the other species were affected slightly. Especially. E. indica showed linearity in the relationship between germination percentage and GA concentration. So, It seemed that E. indica can be used as a bioassy material for GA. Considering the phenological habits of weed species, the seeds were buried under soil for long time(more than 1 month) over winter. When seeds were buried in soil, the degree of dormancy was drastically decreased. Especially, germination of seeds buried were increased under alternating temperature. The germination rates of Persicaria ssp. and Chenopodium ssp. were increased by 50% order alternating temperature after burial for seven weeks.

• Korean journal of applied entomology
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• v.46 no.2
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• pp.261-267
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• 2007

Bioassay of mosquito, Culex pipiens molestus, larva was investigated by several environment-friendly insecticides. These insecticides were Novaluron as chitin synthesis inhibitor, Metho-xyfenozide as ecdysone agonist, Pyriproxyfen as juvenile hormone mimic, and Spiromesifen as lipid biosynthesis inhibitor. The 50% lethal concentration $(LC_{50})$ of these insecticides were 0.00039, 0.07193, 0.65006 and 0.04839 ppm, respectively. Novaluron has lower concentration than any other insecticide. To determine the treatment time against larval stages, insecticides were applied to different larval stages of C. pipiens molestus. Mortality ratios of mosquito larva treated with Novaluron were 100.0, 84.5, 71.0 and 48.5% on 2, 4, 7 and 10 days after hatching from eggs, respectively. Otherwise, with the other insecticides, mortality ratios were under 80% with 2 days old larva. When exposure periods were tested to 3 or 4 days old larva against 4 insecticides, at least 3 hours were needed to 100% control effect against Novaluron, and over 12 hours with other insecticides.

• Tuberculosis and Respiratory Diseases
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• v.45 no.3
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• pp.553-564
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• 1998

Background: The immediate hoot response to LPS is the production of proinflammatory cytokines that act as intercellular mediators in inflammatory reactions, including acute lung injury. These "early response" cytokines transmit signals from recognition cells to target or effector cells. This host response is further amplified by the expression of leukocyte chemoattractants, growth factors, and adhesion molecules, resulting in an array of proinflammatory events. This experiment was performed to define the lung origin of proinflammatory cytokines, such as TNF-$\alpha$, IL 6 in early periods of endotoxin induced acute lung injury (ALI). Method: The healthy male Sprague-Dawley, weighted 150 - 250g, were divided into saline control (NC) and endotoxemia-induced ALI (ETX-), and leukopenic endotoxemia-induced ALI (CPA-ETX-Group) which was induced by cyclophosphamide, 70 mg/kg i.p. injection. Acute lung injury was evoked by LPS, 5 mg/kg, intravenously administered. Bronchoalveolar lavage was performed at 0, 3, 6 h after LPS-treated to estimate the influx of phagocytes and concentration of total protein, and cytokines as TNF-$\alpha$ and IL 6 by a bioassy using MIT method. We also examined the localization of TNF-$\alpha$ and IL 6 protein in endotoxemia-challenged lung tissue by immunohistochemical stain (IH). Results: The total cell, macrophage and PMN count in BALF were elavated in ETX group compared to NC(p<0.05). In CPA-ETX group, total cell and macrophage count in BALF were not changed compared to NC. but PMN count was markedly reduced and it took part in less than 0.1 % of total BAL cells (p<0.01). The protein concentration in BALF were significantly increased in ETX and CPA-ETX group Compared to NC (p<0.05), but there was significant difference between ETX- and CPA-ETX group only at 6 h (p<0.05). This observation suggested that even if PMNs are involved in the pathogenesis of acute lung injury, their role cannot be viewed as essential The concentration of TNF-$\alpha$ and IL 6 in BALF was significantly increased in the ETX- and CPA-ETX group compared to NC. There was no difference between ETX- and CPA-ETX group. In IH, anti-TNF-$\alpha$- and anti-IL 6 antibody was strongly localized at interstitial monocytes and alveolar macrophages in endotoxemia-challenged lung tissue. From above point of view, activated alveolar macrophage/monocyte considered as a prominent source of proinflammatory cytokines in endotoxemia-challenged lung injury. Conclusion: The prominent source of proinflammatory cytokines in early periods of endotoxemia-induced lung injury will be the activated resident macrophages like an alveolar macrophage and interstitial monocytes. The pulmonary macrophage/monocyte will impact the initiation and continuance of lung injury without PMNs's certain inflammatory role, particularly in endotoxemia-induced acute lung injury.