• KSBB Journal
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• v.13 no.5
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• pp.469-476
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• 1998

Among 31 water-born microbial strains isolated from various sites in Korea, strain DJ-4 was selected as a test organism for toxicity measurements in that its growth was completely inhibited by the presence of 668.4 mg/L of chloroform and 297.5 mg/L of toluene in the liquid LB medium whereas others did not. It was observed that lag periods and specific growth rates of DJ-4 batch vial cultures were prolonged and decreased, respectively, by phenol, benzene, toluene, ethylbenzene, p-xylene, perchloroethylene, trichloroethylene, and chloroform at the concentrations between 3.6 and 417.8 mg/L. There changes were found to be linear with respect to the concentrations of the toxic compounds. From the first-order regression equations, 50% effective concentrations (EC50${\mu}$ for concentrations of toxic compounds causing 50% decrease of specific growth rates and EC50lag for 50% increase of length of lag periods) were calculated for each compounds. By comparing DJ-4 EC50${\mu}$ values with Daphnia LC50's from a literature for benzene, ethylbenzene, toluene, and trichloroethlyene, it was concluded that microbial specific growth could be a new, fast, and reliable parameter for toxicity tests.

• Fisheries and Aquatic Sciences
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• v.2 no.2
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• pp.155-160
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• 1999

Studies on detoxification of Paralytic Shellfish Poison (PSP)-infested oyster, Crassostrea gigas were carried out using available processing resources. Changes of paralytic shellfish toxin components and specific toxicity during canning process were also investigated with high performance liquid chromatography (HPLC). Toxic oysters collected at Hachong in Koje Bay were used for experimental samples. The toxicity of oysters with range of 185-778 ug/100g was reduced below the quarantine limit of 80 ug/100g or not detected level by the mouse bioassay after canning process. The mole $\%$ of toxin components in the shucked oyster was in the order of 25.1 mole $\%$ of gonyautoxin 1, 19.2 mole $\%$ of gonyautoxin 3, 17.2 mole $\%$ of gonyautoxin 4 and 14.6 mole $\%$ of gonyautoxin 2. This sample had tracing amounts of Cl, C2, saxitoxin and neosaxitoxin. In the case of specific toxicity, the major toxins were consisted of gonyautoxin 1-4. The sum of gonyautoxin 1, 2, 3 and 4 was 80% of total toxicity of oyster. Saxitoxin and decarbamoylsaxitoxin were the more thermostable than any other toxin components.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.6
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• pp.900-908
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• 1996

Changes of paralytic shellfish toxin components and specific toxicity in blue mussel, Mytilus edu/is and oyster, Crassostrea gigas during canning process were investigated by high performance liquid chromatography (HPLC). The $mole\%$ of the frozen shucked blue mussel were in order of $27.5\;mole\%$ of gonyautoxin 1, $23.0\;mole\%$ of gonyautoxin 8 (C1) and $23.0\;mole\%$ of epi-gonyautoxin 8 (C2), while those of the frozen shucked oyster were in order of $29\;mole\%$ of C1, $22\;mole\%$ of C2, $16.7\;mole\%$ of gonyautoxin 2. Both samples had minor amounts of saxitoxin and neosaxitoxin. On the other hand, in case of specific toxicity, the major toxins were consisted of gonyautoxin $1\~4$ in both sample. The toxicity of gonyautoxin $1\~4$ were 88 and $84\%$ in blue mussel and oyster, respectively. According to the experimental results, C1, C2 and gonyautoxin 4 were very sensitive to heat treatment, while gonyautoxin 2 and saxitoxin were pretty heat resistant than any other toxin components.

• Journal of Korean Society for Quality Management
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• v.39 no.2
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• pp.329-336
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• 2011

The purpose of Phase I clinical trial is to identify the maximum tolerated dose with specific toxicity rate. The standard TER design does not guarantee the pre-specified toxicity rate. It depends on the dose-toxicity curves. Therefore it is necessary to check the expected toxicity rate of various dose-toxicity curves before we conduct clinical trials. We developed TERAplusB library to help this situation, especially in cancer research. This package will help design the cancer clinical trial. We can compare the expected toxicity rates, the expected number of patients, and the expected times calculated with various dose-toxicity curves. This process will help find the best clinical trial design of the proposed drug.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.13-13
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• 2003

Methylmercury (MeHg) is a ubiquitous environmental toxicant that can be exposed to humans by ingestion of contaminated food including fish and bread. MeHg has been suggested to exert its toxicity through its high reactivity to thiols, generation of arachidonic acid and reactive oxygen species (ROS), and elevation of intracellular $Ca^{2+}$ levels (［$Ca^{2+}$］$_{i}$). However, the precise mechanism has not been fully defined. Here we show that phosphatidylcholine-specific phospholipase C (PC-PLC) is a critical pathway for MeHg-induced toxicity. MeHg activated the acidic form of sphingomyelinase (A-SMase) and group IV cytosolic phospholipase $A_2$ ($cPLA_2$) downstream of PC-PLC, but these enzymes as well as protein kinase C were not linked to MeHg's toxicity. Furthermore, MeHg produced ROS, which did not cause the toxicity. However, D6O9, an inhibitor of PC-PLC, significantly reversed the toxicity in a time- and dose-dependent manner in MDCK and SH-5YSY cells. Addition of EGTA to culture media resulted in partial decrease of [$Ca^{2+}$］$_{i}$ and partially blocked cell death. In contrast, D609 completely prevented cell death with parallel decreases in diacylglycerol and ［$Ca^{2+}$］$_{i}$. Together, our findings indicated that MeHg-induced toxicity was caused by elevation of ［$Ca^{2+}$]$_{i}$ through activation of PC-PLC. The toxicity was not attributable to the signaling pathways such as $cPLA_2$, A-SMase, and PKC, or to the generation of ROS.

• Korean Journal of Pharmacognosy
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• v.40 no.3
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• pp.251-256
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• 2009

Cordyceps bassiana is a parasitic fungus and used as a Chinese traditional medicine. It has been called as DongChungHaCho(summer-plant, winter-worm) in China. Acute oral toxicity was examined in male and female ICR mice. Butanol fraction from Cordyceps bassiana(BuCb) was administered orally at a dose of 2,500 mg/kg, 5,000 mg/kg, 10,000 mg/kg. No death and abnormal clinical signs were observed throughout the administration period. The acute toxicity test on mouse did not show any oversign in net body weight gain, food and water consumptions, organ weights, gross pathological findings by different doses of BuCb. Also, biochemical examination revealed no evidence of specific toxicity. These findings show that BuCb has wide margin of safety on acute toxicity with single exposure.

• Journal of Life Science
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• v.7 no.4
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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.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.2
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• pp.205-209
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• 1998

This study was conducted to evaluate the effect of triacetin(TA) treatment during manufacturing carbon dual filter for the adsorption of cigarette smoke components by activated carbons. The measurements were carried out by separation of activated carbon from carbon dual filter, and the specific surface area analyzed. The specific surface area of activated carbon from the domestic cigarette filter and from the foreign cigarette filter by degassing at 9$0^{\circ}C$ was 163$\pm$32$m^2$/g, and 16.6$\pm$1.9$m^2$/g, respectively. Those values were very lower than that of degassing at 35$0^{\circ}C$ (Domestic brand: 952$\pm$30$m^2$/g, and Foreign brand: 847$\pm$73$m^2$/g). By comparing the adsorption capacity of acetone and benzene with and without triacetin treated activated carbon, there was a 20% reduction of adsorption capacity by 5% triacetin treatment. Also, from the cilia toxicity test with carbon dual filter treated 0 % TA and 8 % TA, the cilia survival time was 706$\pm$74sec. and 603$\pm$64sec. for 0% TA and 8% TA, respectively. The delivery rate of vapour phase of cigarette smoke, which consists of main components of cilia toxicity, was higher at 8% TA filter than 0 % TA filter. Our results indicate that the treated TA covered the micro-pore of activated carbon, and then reduced specific surface area, finally, decreased the adsorption of vapour phase from cigarette smoke.

• Toxicological Research
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• v.19 no.1
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• pp.51-66
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• 2003

This study was performed to evaluate single and repeated-dose toxicities of Bee Venom Extracts (F1, F3) in Spraque-Dawley. F1 was injected subcutaneously to rat at dose levels of 0, 0.0002, 0.002, 0.02 mg/kg/day for single-dose toxicity study and repeated-dose toxicity study. F3 was injected subcutaneously to rat at dose level of 0, 0.003, 0.03, 0.3 mg/kg/day for single-dose toxicity study and repeated-dose toxicity study. In both studies, there were no dose related changes in mortality, clinical sign, body weight change, food and water consumption, opthalmoscopy, organ weights, urine analysis, biochemical examination, and hematological findings of all animals treated with Bee Venom (F1, F3). Gross and histopathological findings revealed no evidence of specific toxicity related to Bee Venom (F1, F3). These results suggest that the subcutaneous NOEL (No Observed Effect Level) of Bee Venom (F1, F3) may be over F1 -0.02 mg/kg, F3-0.3 mg/kg.

• Journal of Applied Biological Chemistry
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• v.61 no.4
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• pp.411-416
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• 2018

Chlorpyrifos (CPF) is one of the most heavily used organophosphate pesticides and is useful as an insecticide drug. However, CPF also causes toxic effects in nontarget organisms, including humans and animals. Jageum-Jung (JGJ) is a traditional oriental medicine, composed of five specific herbs with antioxidant and hepatoprotective properties, used for detoxification. In the present study, highly concentrated CPF was orally administrated to male Institute of Cancer Research mice to produce acute toxicity, and the protective effects of JGJ administration were investigated through statistical analysis of changes in body and organ weights and serum biochemical parameters. JGJ caused body and organ weights to recover and reduced the levels of serum biochemical parameters indicative of liver damage, such as glutamic oxalate transaminase, glutamic pyruvate transaminase, alkaline phosphatase, lactic dehydrogenase, urea, glucose, total cholesterol, and triglyceride, that had been increased by CPF treatment. Our results demonstrated that JGJ ameliorates the effects of acute chlorpyrifos-induced toxicity. Therefore, JGJ has the potential to be used as a traditional medicine to alleviate insecticide toxicity.