• 한국환경과학회지
• /
• 제7권4호
• /
• pp.501-504
• /
• 1998

Vibrlo vulnificus가 병원성을 일으키는 한가지 요인으로서 iron의 역할을 본 연구에서 알아보고 V. vulnificus의 성장에 미치는 사람과 토끼 혈청에서의 iron과 $CCl_4$의 영향도 조사하였다. 쥐에 iron을 주사한 결과 50% 치사량이 감소하였고 감염 후 치사 시간도 감소하였으며 $CCl_4$,로 감염된 간에 의해서 혈청 중 iron준위는 증가하였다. 쥐를 치사시키는데 필요한 접종량은 혈청 중 iron준위와 직접적으로 상호 관련성이 있었다. Iron은 이 미생물이 포유류 혈청에서 살아남거나 성장하는 능력에 있어서 제한 요인으로 나타났다. 시험관 내에서와 생체 내에서 이들 결과는 iron이 V. vulnificus의 병원성에 있어서 중요한 역할을 한다는 강한 증거를 제공해주었다.

• Journal of Microbiology and Biotechnology
• /
• 제25권11호
• /
• 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.

• 한국양식학회지
• /
• 제5권2호
• /
• pp.177-182
• /
• 1992

카이토산이 수중의 수은 제거에 미치는 영향을 알아보기 위하여, 금붕어를 사용하여 염화수은을 사용한 군 (대조군, n=75, 농도=0.6 $mg/{\ell}1.0mg/{\ell}$)과 염화수은에 카이토산을 첨가한 군(실험군, n=75, 농도=1.2 $mg/{\ell}\~2.0mg/{\ell}$)의 폐사율을 비교 분석하여 다음과 같은 결과를 얻었다. 염화수은에 대한 금붕어의 48 시간 동안의 반수치사 농도 ($LC_{50}$)는 0.6$mg/{\ell}$ 와 0.7 $mg/{\ell}$ 사이였다. 대조군에 있어서 수은의 농도가 증가함에 따라 폐사율이 현저하게 증가되었다 (P<0.05). 그러나, 카이토산이 첨가된 실험군에 있어서는 폐사율이 감소되었으며 수은 농도가 높은 경우 $100{\%}$ 폐사에 이르는 시간이 연장되었다(P<0.05). 상기 결과로서 카이토산이 수중의 수은 제거와 금붕어에 수은의 독성을 완화시키는 효과가 있는 것으로 사료된다.

• 한국식품영양과학회지
• /
• 제18권3호
• /
• pp.255-264
• /
• 1989

고사리의 ethanol extract를 독성실험한 결과는 mouse에 시료 10g/kg까지는 급성독$(LD_{50})$을 나타내지 않았다. Rat에 매일 시료40mg/kg, 400mg/kg, 1200mg/kg을 경구투여한 처음 7일간에는 체중, 해부소견, 혈액의 생화학적 검사에서 별이상이 없었다. 14일째 전시료투여군의 체중증가율은 대조군보다 평균 약 7% 감소를 보이고 혈청의 생화학적 측정치가 대부분 약간 증가하였다. 21일째 400mg/kg군과 1200mg/kg군의 체중증가율이 대조군보다 $6.7{\sim}5.7%$ 감소되고 1200mg/kg군 1필이 황색간증세를 보였다. 모든 시험군 GPT 및 GOT는 각각 $88{\sim}102u$와 $164{\sim}200u$로 증가하고 alkaline phosphatase도 상승하여 중독의 징후를 보였다. 28일째 400mg/kg군과 1200mg/kg군의 체중증가율이 대조군보다 감소되고 이들군에서 각각 $1{\sim}2$필이 황색간을 보였다. 1200mg/kg군 2필이 소장염을 보였다. 모든 시험군은 GPT $92{\sim}116u$와 GOT $56{\sim}215u$ 및 alkaline phosphatase $57{\sim}70u$로 증가 되었다.

• 한국산업보건학회지
• /
• 제25권1호
• /
• 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.

• 대한수의학회지
• /
• 제43권1호
• /
• 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
• /
• 제31권
• /
• 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.

• 한국응용곤충학회지
• /
• 제4권
• /
• 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
• /
• 제11권6호
• /
• 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.

• 생약학회지
• /
• 제10권2호
• /
• pp.61-67
• /
• 1979

Two pure saponin components, Panax saponin C (protopanaxatriol derivative, ginsenoside Re) and Panax saponin E (protopanaxadiol derivative, ginsenoside $Rb_l$) were isolated from Panax ginseng root and their acute toxicities in mice and antistress effects in rats were investigated. Average lethal doses $(LD_{50})$ of ginsenoside Re were 130mg/kg (i.v.), more than 1,000mg/kg (i.p.) and more than 1,500mg/kg (s.c.), respectively. Average lethal dose of ginsenoside $Rb_{1}$ was 243mg/kg intravenously. Adrenal ascorbic acid and cholesterol contents were significantly decreased when normal rats were exposed to heat $(40^{\circ}C)$ for 30 min. The reduction of the adrenal ascorbic acid and cholesterol contents in rats was partially prevented when the rats received the ginseng saponins prior to exposure to heat stress and most pronounced effects were observed in rats received ginsenoside Re. However, it was found that administration of ginseng alone, without stress, did not significantly change the ascorbic acid and cholesterol contents in adrenal glands. Eosinophil counts in the blood of the rats were elevated when the rats were exposed to the heat stress, and the elevation of the eosinophil counts were prevented with the ginseng saponins under the stress, but the changes were all insignificant statistically.