• Korean Journal of Environmental Biology
• /
• v.35 no.4
• /
• pp.706-714
• /
• 2017

An investigation of the effects of Pb for domestic anuran embryos were evaluated with the Frog Embryo Teratogenesis Assay; Xenopus (FETAX). Depending on the species, the difference between the embryo size and the embryonic development time was determined. As a result, mortality and malformation rates were increased, malformation patterns were changed and larval body length were decreased in a dose dependent manner of the Pb. The half maximal lethal concentration ($LC_{50}$) of the Bufo gargarizans, Hyla japonica, Rana nigromaculata and Bombina orientalis were 0.58, 0.49, 0.52, $0.54mg\;L^{-1}$, respectively. The half maximal effective concentration ($EC_{50}$) of the Bufo gargarizans, Hyla japonica, Rana nigromaculata and Bombina orientalis were 0.35, 0.74, 0.30, $0.29mg\;L^{-1}$, respectively. The teratogenic index (TI) were 1.66 in the Bufo gargarizans, 1.81 in the Hyla japonica, 1.73 in the Rana nigromaculata and 1.86 in the Bombina orientalis, respectively. Therefore, the Pb seems likely to have a teratogenic effect in all four species' embryonic development. The Bombina orientalis was the most sensitive to the Pb. This means that the difference between the different species, even if they have all been exposed to the same concentration of pollutants depending on the species. The result above show that the Pb acts as a teratogenic agent in the development of the four domestic frog species.

• Journal of Environmental Science International
• /
• v.7 no.4
• /
• pp.501-504
• /
• 1998

The role of iron as a possible pathogenic factor in the Infection of V. vulnificus was examined in thins paper The effects of iron and $CCl_4$ on the growth of V. vulnificus in human and rabbit sera were also done. Injection of iron to mice resulted in a lowering of the 50% lethal dose and in a reduction in the time of death postinfection. Serum iron levels were also elevated by damaged livers with infections of $CCl_4$- The inoculum size required to kill these mice was directly correlated with serum iron Irvels. Iron appeared to be the limiting factor In the ability of thins organism to survive or grow in mammalian sera. These results, both in vitro and In vivo, provided strong evidence that iron may play a major role In the pathogenesis of V. vulnificus.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.11
• /
• pp.1960-1965
• /
• 2015

Rabbit hemorrhagic disease virus (RHDV) is highly contagious and often causes fatal disease that affects both wild and domestic rabbits of the species Oryctolagus cuniculus. A highly pathogenic RHDV variant (RHDVa) has been circulation in the Korean rabbit population since 2007 and has a devastating effect on the rabbit industry in Korea. A highly pathogenic RHDVa was isolated from naturally infected rabbits, and the gene encoding the VP60 protein was cloned into a baculovirus transfer vector and expressed in insect cells. The hemagglutination titer of the Sf-9 cell lysate infected with recombinant VP60 baculovirus was 131,072 units/50 μl and of the supernatant 4,096 units/50 μl. Guinea pigs immunized twice intramuscularly with a trial inactivated RHDVa vaccine containing recombinant VP60 contained 2,152 hemagglutination inhibition (HI) geometric mean titers. The 8-week-old white rabbits inoculated with one vaccine dose were challenged with a lethal RHDVa 21 days later and showed 100% survival rates. The recombinant VP60 protein expressed in a baculovirus system induced high HI titers in guinea pigs and rendered complete protection, which led to the development of a novel inactivated RHDVa vaccine.

• Journal of Aquaculture
• /
• v.5 no.2
• /
• pp.177-182
• /
• 1992

Experiments were conducted with goldfish exposed to various levels of mercuric chloride(control group) and mercuric chloride with chitosan (experimental group). Dilutions of these two solutions were made in the concentration ranges 0.6 to 1.0 $mg/{\ell}$ and 1.2 to 2.0 $mg/{\ell}$, respectively. Fifty percent lethal concentration of mercuric chloride($LC_{50}$) for 48 hours with the species was between 0.6 and 0.7 $mg/{\ell}$. Exposure of goldfish to mercury produced a marked, dose-dependent mortality with elevation of concentration (P<0.05). However, at each concentration of mercuric chloride treated with chitosan, mortality decreased significantly compared to control group (P<0.05).

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.18 no.3
• /
• pp.255-264
• /
• 1989

The results of toxicity test using mice and rats for ethanol extract of Bracken Fern collected in Kwang Ju area were shown as follows ; Up to the dose of 10g per kg of mice administered intraperitoneally there was no lethal toxicity so that it was impossible to calculate the median lethal dose $(LD_{50})$. For the first 7 days experiment all rats administered frond extract grouping in 40mg, 400mg, and 1200mg per kg of rat as the daily oral doses did not show any characterized sign in the weight gain rate, anatomical findings, and biochemical studies. For 3 weeks following the first week the weight gain rates of all test group were reduced to $4.2{\sim}7%$ below the weight gain rate of control. In this period serum GPT, GOT, and Alkaline phosphatase value were increased significantly indicating the symptoms of Bracken Fern poisonings. The pathological findings of all test groups for 28 days showed acute and chronic intestinal lesion and liver damage with steatosis especially in 1200g/kg rat groups. In this experiment the Bracken poisonings appeared slowly in rats of 400mg/kg and 1200mg/kg for two weeks and in rats of 40mg/kg for 3 weeks, showing the symptoms of lowering of weight gain rate, subacute hepatitis, hepatic steatosis and enteritis in 28 days experiment.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.25 no.1
• /
• pp.45-57
• /
• 2015

Objectives: This study aims to compare the physicochemical characteristics, toxicological data with Occupational Exposure Limits (OELs) of chemicals under the Occupational Safety and Health Act(OSHA) regulated by the Ministry of Employment and Labor of Korea. Methods: Information on chemicals which have OELs on physicochemical characteristics and toxicological data was collected using Material Safety Data Sheet(MSDS) from Korea Occupational Safety and Health Agency(KOSHA) and the Korea Information System for Chemical Safety Management(KISChem) in 2014. Statistical analyses including correlation and simple regression were performed to compare the OELs with chemical characteristics including molecular weight, boiling point, odor threshold, vapor pressure, vapor density, solubility and octanol-water partition coefficient(OWPC) and toxicological data such as median lethal dose($LD_{50}$) and median lethal concentration($LC_{50}$). Results: A total of 656 chemicals have OELs under OSHA in Korea. The numbers of chemicals which have eight-hour time weighted average(TWA) and short term exposure limits(STEL) are 618 and 190, respectively. TWA was significantly correlated with boiling point and STEL was only correlated with vapor pressure among physicochemical characteristics. Solubility and OWPC between "skin" and "no skin" substances which indicate skin penetration were not significantly different. Both $LD_{50}$ and $LC_{50}$ were correlated with TWA, while the $LC_{50}$ was not with STEL. As health indicators, health rating and Emergency Response Planning Guidelines(ERPG) rating as recommended by the National Fire Protection Association(NFPA) and American Industrial Hygiene Association(AIHA) were associated with OELs and reflect the chemical hazards. Conclusions: We found relationships between OEL and chemical information including physicochemical characteristics and toxicological data. The study has an important meaning for understanding present regulatory OELs.

• Korean Journal of Veterinary Research
• /
• v.43 no.1
• /
• pp.57-66
• /
• 2003

Single and 28-day repeated dose toxicity studies of botulimnn toxin type A were carried out in ICR mice and Sprague-Dawley rats, respectively. In the single dose toxicity study, botulinwn toxin was injected intraperitoneally to male and female mice at a single dose of 40, 59, 89 133 and 200 ng/10 ml saline/kg. All animals died from 59 ng/kg group. Some clinical signs, such as decrease in locomotor activity, dyspnea, prone position and ptosis, were observed in most of both sexes from 59 ng/kg group, but no signs were seen in all animals at 40 ng/kg group. The results showed that the median lethal dose of botulinum toxin might be in the range of 40-59 ng/kg in both sexes. In the repeated dose toxicity study, the test material was administered intradermally for 28 days at doses of 0 (vehicle-treated control), 1.25, 2.5, 5.0 and $10.0ng/head/50{\mu}{\ell}$ saline in male and female rats. No test material-related changes were noted in survivals, clinical signs, food and water consumptions and gross finding in any group. Botulinum toxin treatment significantly decreased the body weight gain rate in male of 5.0 ng/head group and over and in female of 10.0 ng/head group compared to vehicle-treated control. One or more relative organ weights (i.e., spleen, thymus, liver and kidney) were increased significantly from 5.0 ng/head group compared to vehicle-treated control in both sexes. Serum biochemistry revealed increases in aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine phosphokinase, total protein and albumin in male, and increases in AST and ALT and decreases in $K^+$ and $Cl^-$ in female without dose-pendent manners. In the histopathological study, physical stimulation by needle caused slight inflammations of dennis. In addition, botulinum toxin treatment induced denervation of nerve cell and disuse of muscle, resulting in atrophy of skeletal muscle in both sexes from 2.5 ng/head group. When the antibodies to toxin were determined in all animals, a significant increase in serum antibodies was observed from 5.0 ng/head group. The results showed that the NOAEL of botulinum toxin might be 1.25 ng/head for 28-day repeated dose toxicity in rats.

• Environmental Analysis Health and Toxicology
• /
• v.31
• /
• pp.11.1-11.6
• /
• 2016

Objectives A hazard assessment of di(2-ethylhexyl) phthalate (DEHP), a commonly used workplace chemical, was conducted in order to protect the occupational health of workers. A literature review, consisting of both domestic and international references, examined the chemical management system, working environment, level of exposure, and possible associated risks. This information may be utilized in the future to determine appropriate exposure levels in working environments. Methods Hazard assessment was performed using chemical hazard information obtained from international agencies, such as Organization for Economic Cooperation and Development-generated Screening Information Data Set and International Program on Chemical Safety. Information was obtained from surveys conducted by the Minister of Employment and Labor ("Survey on the work environment") and by the Ministry of Environment ("Survey on the circulation amount of chemicals"). Risk was determined according to exposure in workplaces and chemical hazard. Results In 229 workplaces over the country, 831 tons of DEHP have been used as plasticizers, insecticides, and ink solvent. Calculated 50% lethal dose values ranged from 14.2 to 50 g/kg, as determined via acute toxicity testing in rodents. Chronic carcinogenicity tests revealed cases of lung and liver degeneration, shrinkage of the testes, and liver cancer. The no-observed-adverse-effect level and the lowest-observed-adverse-effect level were determined to be 28.9 g/kg and 146.6 g/kg, respectively. The working environment assessment revealed the maximum exposure level to be $0.990mg/m^3$, as compared to the threshold exposure level of $5mg/m^3$. The relative risk of chronic toxicity and reproductive toxicity were 0.264 and 0.330, respectively, while the risk of carcinogenicity was 1.3, which is higher than the accepted safety value of one. Conclusions DEHP was identified as a carcinogen, and may be dangerous even at concentrations lower than the occupational exposure limit. Therefore, we suggest management of working environments, with exposure levels below $5mg/m^3$ and all workers utilizing local exhaust ventilation and respiratory protection when handling DEHP.

• Korean journal of applied entomology
• /
• v.4
• /
• pp.67-74
• /
• 1965

The work on the 'Studies of radiosensitivity' in Korea has been initiated since 1959 by the author at various institutions in home and foreign countries, and more than 20000 of plant materials in 73 varieties and 41 kinds are treated under varied conditions for the studies of radiosensitivity in plants. However, a study of the susceptibility to radiation in insect pests as well as their biological effects has not been previously reported in this country. During the year of 1964 and 1965, near 50000 of insects at the stages of adult, egg, larva and pupa in 14 different kinds are irradiated under acute X and gamma rays to investigate the behavior of growth and lethality after irradiation, and thrir general tolerances to radiations are compared by the kind of insects, stage of growth, radiation sources and exposured dosages. Through the experiments, it is shown that the lethality in most of insects are high as several kilo roentgens above and no significant effects on pupation. emergence, and oviposition in the treated generation at the dose of 3 Kr. below, but in the following generation , the rice stem borer for instance, no oviposition or decreased laying is observed from the dosages at 3 Kr. to 1 Kr., and the hatching was possible from 1.5 Kr. below of irradiated larvae although laying and hatching are seemed in normal. In general, the lethal dose $50\%$ of tested infect materials at the larval stage can he classified some what 60-80 Kr. for Pine caterpillar, Fall webworm, Camphor silk moth and their relatives, at 40-60 Kr. for Gypsy moth, Monley prominent and some relatives and at 20-30 Kr. for House fly, Rice weevil, Pine sawfly etc. Plant parasitic nematodes such as Hirschmannia and Paratylenchus shown very high resistance to radiation and the LD-50 is observed from 100 Kr. or above. A concept to evaluate the radiosensitivity in insects by taxological family line as a practical measure is not answerable yet, but it ran he solved within the near future through the continuing experiments.

• Nutrition Research and Practice
• /
• v.11 no.6
• /
• pp.452-460
• /
• 2017

BACKGROUD/OBJECTIVES: Turanose, ${\alpha}$-D-glucosyl-($1{\rightarrow}3$)-${\alpha}$-D-fructose, is a sucrose isomer which naturally exists in honey. To evaluate toxicity of turanose, acute and subchronic oral toxicity studies were conducted with ICR mice. MATERIALS AND METHODS: For the acute oral toxicity study, turanose was administered as a single oral dose [10 g/kg body weight (b.w.)]. In the subchronic toxicity study, ICR mice were administered 0, 1.75, 3.5, and 7 g/kg b.w. doses of turanose daily for 13 weeks. RESULTS: No signs of acute toxicity, including abnormal behavior, adverse effect, or mortality, were observed over the 14-day study period. In addition, no changes in body weight or food consumption were observed and the median lethal dose (LD50) for oral intake of turanose was determined to be greater than 10 g/kg b.w. General clinical behavior, changes in body weight and food consumption, absolute and relative organ weights, and mortality were not affected in any of the treatment group for 13 weeks. These doses also did not affect the macroscopic pathology, histology, hematology, and blood biochemical analysis of the mice examined. CONCLUSION: No toxicity was observed in the acute and 13-week subchronic oral toxicology studies that were conducted with ICR mice. Furthermore, the no-observed-adverse-effect level is greater than 7 g/kg/day for both male and female ICR mice.