• Korean Journal of Veterinary Service
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• v.15 no.1
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• pp.58-66
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• 1992

The insecticide p-nitropheny diethyl thiophospate is alse known by the symbol E.605 and a legion of trade names including “parathion”. The insecticide is widely used in agriculture, but it is highly toxic and now clear that parathion behaves like a cholinergic drug by inhibiting the enzyme cholinesterase. In order to know acute toxicity and the changes of glucose concentrations and activity according to time lapsed in female mice given orally single with the half dose to $LD_{50}$ of parathion, glucose contents and cholinesterase activities in serum as well as cholinesterase activities in whole brain and spinal cord were investigated, otherwise median lethal dose ($LD_{50}$) of parathion given orally against female mice was determined. The results obtained were summerized as follows ; 1. $LD_{50}$ value of parathion given orally to female mice was 7.1mg/kg(95% confidence limits, 3.8-13.1mg/kg) 2. The inhibition rate of cholinesterase activities in serum of parathion-administrated mice according to time lapsed were peakly decreased to 61% after 30 minutes in comparison to control group, but activities were completely recovered after 48 hours. 3. The inhibition rate of cholinesterase activities in whole brain of parathion-administrated mice according to time lapsed were peakly decreased to 49% after 2 hours in completely recovered after 24 hours. 4. The inhibition rate of cholinesterase activities in spinal cord of parathion-administrated mice according to time lapsed were peakly decreased to 57% after 2 hours in comparison to control group, but activities were completely recovered after 48 hours. 5. The changes of glucose contents in serum of parathion-administrated mice according to time lapsed and in directly after death due to parathion poisoning were no significantly difference.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2771-2774
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• 2012

Aim: Tumors of upper gastrointestinal tract are among the cancers that have a quite lethal course. Cytotoxic chemotherapy is the most efficient therapeutic modality for metastatic gastric cancer. In patients who do not respond to first-line treatment, the response rate to second-line therapies is generally low and the toxicity rates high. This study concerned the efficacy and the side effect profile of second-line therapy with irinotecan in the patients who were being followed-up with the diagnosis of metastatic gastric cancer in $\dot{I}$zmir, Turkey. Materials and Methods: We retrospectively evaluated the efficacy and toxicity in 31 patients with metastatic gastric adenocarcinoma who presented to the polyclinic of Medical Oncology of Izmir Ataturk Education and Research Hospital between May 2008 and July 2011. All received chemotherapy regimens containing cisplatin, fluoropyrimidine (5-FU) and docetaxel as the first-line therapy for late stage disease. Irinotecan as a single agent was given at a dose of 210 mg/$m^2$ on each 21 days. Irinotecan (180 mg/$m^2$ on day 1), 5-FU (500 mg/$m^2$ on days 1-2) and leucovorin (LV; 60 mg/$m^2$ on days 1-2) as a combined regimen were given over a 14 day period. Results: Median age was 54 (range, 31-70). Irinotecan was given as a combined regimen for median 6 cycles (range, 3-12) and as a single agent for median 3 cycles (range, 1-10). Metastases were detected in one site in six patients (19%), in two different sites in 17 patients (55%) and in three or more sites in eight patients (26%). Four patients (12.9%) showed partial response and six patients (19.3%) showed stable disease. Progression-free survival (PFS) was found to be 3.26 months (95% CI, 2.3-4.2). Median overall survival (OS) was found to be 8.76 months (95% CI, 4.5-12.9). The most commonly seen grade 3/4 side effect was neutropenia but the the therapy was generally well-tolerated. Conclusions: In this study, it was demonstrated that second-line therapy with irinotecan given following the first-line therapy with cisplatin, fluoropyrimidine (5-FU) and docetaxel was efficient and safe. Further studies are needed for confirmation.

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

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.27-27
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• 2021

Yacon [Samallanthus sonchifolius (Poepp. & Endl.) H. Robinson], a member of Compositae plants, has sweet taste and crisp texture. Unlike other Andean root crops such as potato and sweet potato, the cultivation area of yacon has increased recently, since it is known to have large content of fructooligosaccharides (FOS). Since there are no yacon varieties bred in Korea, we have been trying to create new genetic resources using gamma-ray. The optimal gamma-ray dosage for mutation breeding in yacon was investigated. Crown bud and green bud of yacon were exposed to doses of gamma rays from 20 Gy to 80 Gy, and subsequently planted in a greenhouse. After 50 days of sowing, the survival rates and growth decreased rapidly at doses above 40 Gy, while all of crown bud individuals died above 60 Gy. The median lethal dose (LD50) of crown bud and green bud was 22.4 and 36.6 Gy, and the median reduction doses (RD50) for plant height, fresh weights, and tuberous root weight were 20-40 Gy, respectively. A dose of 20-40 Gy was found to be optimal for mutation breeding in yacon. Considering the growth factors, the optimum doses were determined to be within the range of 20-40 Gy for the selection of useful mutant lines. M2-M3 mutant lines were obtained from 20-60 Gy gamma-ray-irradiated M1 plants through clonal propagation. These mutant lines will be used for the development of a new variety of yacon plant with high FOS and no crack tuberous root.

• Environmental Analysis Health and Toxicology
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• v.25 no.2
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• pp.131-143
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• 2010

We performed the tests of acute and subchronic inhalation toxicity of methyl formate, which has limited toxicological data in spite of its widespread use and enhanced hazard consequent on its high volatility. The median lethal concentration ($LC_{50}$) was evaluated to be above 5,000ppm(12.27 mg/L). In the test with subchronic inhalation, there are no deaths, but with reduction of body weight, food intake, organ weight by exposure to 400 (0.98 mg/L) and 1,600 (3.92 mg/L) ppm, dose-dependently. There were statistical differences in some hematological and blood biochemical parameters as compared to control (e.g. neutrophile and lymphocyte in the 1,600 ppm group, calcium and A/G in 1,600 ppm group). Methyl formate under the exposure of 1,600 ppm showed the respiratory findings with nasal, it was confirmed that the chemical has respiratory hazard with 1,600 ppm inhalation exposure, induces nasal epithelial atrophy, olfactory cell degeneration/regeneration and the contraction of olfactory cells, etc. According to the notification with Ministry of Labor (No. 2009-68) for classification, labeling and MSDS of chemicals, it is suggested for methyl formate to be classified as category 4 in acute (10.0$4\leq20.0$ mg/L), category 2 (0.2$\leq$1.0 mg/L/6h, 90 days) in specific target organ-repeated exposure.

• Herbal Formula Science
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• v.20 no.2
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• pp.93-102
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• 2012

Objectives : Traditional medicine Gumiganghwal-tang (GT) has been used in Asia to treat inflammatory diseases including common cold, pain, fever, and algor. In this study we investigated the acute toxicity and safety of GT and fermented GT (FGT). Methods : Acute toxicity and safety were evaluated in male and female ICR mice orally administered 0 (control) and 2,000 mg/kg of GT and FGT. After the administration of GT and FGT, we observed mortality, body weight, clinical symptoms. After necropsy, organ weights were measured and blood analysis was performed. Results : There was no mortality and clinical symptoms according to the administration of GT and FGT. Comparing with control group, there were no significant alterations on the organ weight, complete blood cell count and biochemical parameters. Conclusions : Median lethal dose of GT and FGT considered to be over 2,000 mg/kg in both male and female mice, and recognized as safe with no toxicity.

• Journal of Microbiology
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• v.40 no.3
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• pp.199-204
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• 2002

A microsporidium, from cabbage white bntteflies, Pieris rapae, collected in Korea, was purified and characterized according to its gene structure, spore morphology and pathogenicity. From the observation of the isolate by SEM and TEM, the endospores, exospores and nuclei, about 12 polar filament coils of the polar tube and posterior vacuoles were all identified. The nucleotide sequence was determined for a portion of genomic DNA which spans the V4 variable region of the small subunit rRNA gene. Comparison with the GenBank database for 15 other microsporidia species suggests that this isolate is most closely related to Nosema species. The pathogenicity against cabbage white butterflies was quantified by inoculating variable doses of spores to the second instar larvae. Peroral inoculation at a dosage of 10$\^$8/ spores/ml resulted in the death of all larvae prior to adult eclosion, but at lower spore dosages of 10$\^$4/-10$\^$5/ spores/ml, many adults successfully emerged. The median lethal dose (LD$\_$50/) was deter-mined to be 4.6$\times$10$\^$6/ spores/ml and the isolate also transmitted transovarially to the progeny eggs at a frequency of 92%.

• Journal of Microbiology and Biotechnology
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• v.21 no.7
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• pp.719-727
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• 2011

Botulism is a neuroparalytic disease caused by Clostridium botulinum, which produces seven (A-G) antigenically diverse neurotoxins (BoNTs). BoNTs are the most poisonous substances known to humans, with a median lethal dose ($LD_{50}$) of approximately 1 ng/kg of body weight. Owing to their extreme potency and lethality, they have the potential to be used as a bioterrorism agent. The mouse bioassay is the gold standard for the detection of botulinum neurotoxins; however, it requires at least 3-4 days for completion. Attempts have been made to develop an ELISA-based detection system, which is potentially an easier and more rapid method of botulinum neurotoxin detection. The present study was designed using a synthetic gene approach. The synthetic gene encoding the catalytic domain of BoNT serotype B from amino acids 1-450 was constructed with PCR overlapping primers (BoNT/B LC), cloned in a pQE30 UA vector, and expressed in an E. coli M15 host system. Recombinant protein production was optimized at 0.5 mM IPTG final concentration, 4 h post induction, resulting in a maximum yield of recombinant proteins. The immunogenic nature of the recombinant BoNT/B LC protein was evaluated by ELISA. Antibodies were raised in BALB/c mice using various adjuvants. A significant rise in antibody titer (p<0.05) was observed in the Alum group, followed by the Titermax Classic group, Freund's adjuvant, and the Titermax Gold group. These developed high-titer antibodies may prove useful for the detection of botulinum neurotoxins in food and clinical samples.

• Korean journal of applied entomology
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• v.63 no.1
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• pp.13-23
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• 2024

Vespa velutina nigrithorax du Buysson, 1905 is the invaded species in Korea since 2003. Since its importance as the honey bee pest, beekeepers use insecticides to kill the adult and immature hornets. However, its legality and effectiveness has not been confirmed. This study investigated the susceptibility of insecticides commonly used to control hornets by beekeepers in Korea. Eight insecticides were tested on adult worker and larvae by topical or oral treatment. Adults showed more than 70% mortalities from Clothianidin, Dinotefuran, and Carbosulfan treatment within 30 minutes. Bifenthrin and Cartap hydrochloride showed relatively low toxicity. The median lethal dose (LD₅₀) for Clothianidin, Dinotefuran, and Carbosulfan was 0.29, 0.65, and 2.21 ㎍/bee, respectively. In larval feeding test where 5^th instar larvae were fed 3 times every 24 hours, the mortality began after second treatments. After 3rd treatments (72 h), all insecticides showed mortality more than 70%. The LD₅₀ values of Clothianidin, Dinotefuran, and Carbosulfan to V. velutina were approximately 10 to 100 times higher than those to honey bee, Apis mellifera. This study provides the basic information of those chemical toxicities to Vespa hornet and honey bees.

• Toxicological Research
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• v.26 no.4
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• pp.293-300
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• 2010

tert-Butyl acetate (TBAc) is an organic solvent, which is commonly used in architectural coatings and industrial solvents. It has recently been exempted from the definition of a volatile organic compound (VOC) by the Air Resources Board (ARB). Since the use of TBAc as a substitute for other VOCs has increased, thus its potential risk in humans has also increased. However, its inhalation toxicity data in the literature are very limited. Hence, inhalation exposure to TBAc was carried out to investigate its toxic effects in this study. Adult male rats were exposed to TBAc for 4 h for 1 day by using a nose-only inhalation exposure chamber (low dose, $2370\;mg/m^3$ (500 ppm); high dose, $9482\;mg/m^3$ (2000 ppm)). Shamtreated control rats were exposed to clean air in the inhalation chamber for the same period. The animals were killed at 2, 7, and 15 days after exposure. At each time point, body weight measurement, bronchoalveolar lavage fluid (BALF) analysis, histopathological examination, and biochemical assay were performed. No treatment-related abnormal effects were observed in any group according to time course. Based on those findings, the median lethal concentration ($LC_{50}$) of TBAc was over $9482\;mg/m^3$ in this study. According to the MSDS, the 4 h $LC_{50}$ for TBAc for rats is over $2230\;mg/m^3$. We suggested that this value is changed and these findings may be applied in the risk assessment of TBAc which could be beneficial in a sub-acute study.