• Journal of Yeungnam Medical Science
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• 제41권1호
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• pp.30-38
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• 2024

Background: Although Korea ranks first in the suicide rate of elderly individuals, there is limited research on those who attempt suicide, with preventive measures largely based on population-based studies. We compared the demographic and clinical characteristics of elderly individuals who attempted suicide with those of younger adults who visited the emergency department after suicide attempts and identified the factors associated with lethality in the former group. Methods: Individuals who visited the emergency department after a suicide attempt from April 1, 2017, to January 31, 2020, were included. Participants were classified into two groups according to age (elderly, ≥65 years; adult, 18-64 years). Among the 779 adult patients, 123 were elderly. We conducted a chi-square test to compare the demographic and clinical features between these groups and a logistic regression analysis to identify the risk factors for lethality in the elderly group. Results: Most elderly participants were men, with no prior psychiatric history or suicide attempts, and had a higher prevalence of underlying medical conditions and attributed their attempts to physical illnesses. Being sober and planning suicide occurred more frequently in this group. In the elderly group, factors that increased the mortality rate were biological male sex (p<0.05), being accompanied by family members (p<0.05), and poisoning as a suicide method (p<0.01). Conclusion: Suicide attempts in elderly individuals have different characteristics from those in younger adults and are associated with physical illness. Suicides in the former group are unpredictable, deliberate, and fatal. Therefore, tailored prevention and intervention strategies addressing the characteristics of those who are elderly and attempt suicide are required.

• 한국토양동물학회지
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• 제1권2호
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• pp.81-88
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• 1996

Entomopathogenic nematodes, Steinernema carpocapsae, was able to invade and kill the several lepidopteran pests including the beet armyworm, Spodeptera exigua Hubner, which was the most effective target host. The beet armyworms treated with the effective nematode concentrations were died within 48 hrs. The lethal effect of the nematode was varied among the developmental stages of the host. The fifth instar larvae of the beet armyworm was more vulnerable to the nematode than the third instar larvae. Pupae was, however, refractory to the nematode. All three bioessays (topical application, filter paper test, and soil treatment) showed the positive correlation between the number of the treated nematodes and the mortality of the host. Topical application was the most effective and fast-acting method so that it gave the lethal effect 2 days earlier than did filter paper test at the same number of the treated nematodes. Soil treatment required higher number of the nematodes to get the effective lethality than did filter paper test. The fifth instar larvae of the beet armyworm expressed the specific hemolymph proteins of 5 to 10 kDa in response to nematode infection.

• 동의신경정신과학회지
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• 제15권1호
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• pp.101-119
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• 2004

Ginseng Radix Alba and Cyperi Rhizoma were investigated for their anti-depressant effects. For this purpose, forced-swimming test, tail suspension test, hot plate test, reserpine-induced hypothermia, aggressive behavior test were performed. In addition, the brain content of 5-hydroxyindoleacetic acid(a metabolite of serotonin), the monoamine oxidase activity, anticonvulsant effect, sleep enhancement effect were determined. The results are as follows: In the forced swimming test, Ginseng Radix diminished the duration of immobility by 45.5% compared to the control group, while Cyperi Rhizoma showed weaker effect (12.4% reduction) at 2g/kg. In the tail suspension test, the effect of Ginseng Radix(43.7% reduction) are also better than that of Cyperi Rhizoma(15.6% reduction) at 2g/kg. In the hot plate test, Ginseng Radix showed no difference as compared to control, while Cyperi Rhizoma increased the jump latency time by about 25% after administration for 10 days. In the reserpine-induced hypothermia test, both drugs slowly dropped the body temperature compared to the control group, especially the rate of hypothermia of Ginseng Radix was 24.0% at 1g/kg. In the aggressive behavior test, both drugs delayed the onset time, decreased the duration and frequency, of which effects were better in Cyperi Rhizoma. The content of 5-hydroxyindoleacetic acid in mice brain was slightly increased in Ginseng Radix, while Cyperi Rhizoma increased its level almost to the control group. Both drugs inhibited the monoamine oxidase activity in a dose-dependent manner, but the effect(51.2%) of Cyperi Rhizoma was more potent than the effect(11.8%) of Ginseng Radix. In the pentobarbital-induced sleep test, Cyperi Rhizoma exhibited no significant difference against the control group, while Ginseng Radix showed about two-fold enhancement at 2g/kg. The anticonvulsant effect of both drugs delayed the onset time, shortened the duration of convulsion and diminished the lethality, but Ginseng Radix were better than Cyperi Rhizoma.

• 한국식품영양과학회지
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• 제24권5호
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• pp.690-694
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• 1995

광범위한 천연항균제로 그 활용이 고려되고 있는 grapefruit 종자추출의 안전성을 검토하기 위하여 급성 경구독성, 피부자극 및 급성 안점막 자극시험을 수행하였다. 실험 흰쥐에 대한 급성 $LD_{50}$값은 3.75g/kg이었으며, 피부에 대한 독성은 약한 편으로 부종 등의병변이 거의 생기지 않았으나 눈에 대한 자극성이 있는 것으로 나타났다.

• 생약학회지
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• 제29권4호
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• pp.331-337
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• 1998

Most Annonaceous acetogenins are potently bioactive and offer exciting potential as new antitumor, pesticidal and other bioactivites. The major mode of action of the acetogenin is inhibition of electron transport in the mitochodria. Two known cytotoxic ketolactone Annonaceous acetogenins, (2,4-cis)-isoannonacin (compound 1) and (2,4-trans)-isoannonacin (compound 2), have been isolated from Asimina triloba (Annonaceae) by bioactivity directed fractionation. The structures were characterized on the basis of chemical and spectral data. Compounds 1 and 2, which are known but are first isolated from the seeds of this species, were ob-tained. In brine shrimp lethality test (BST), 1 and 2 exhibited cytotoxicity.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.82-87
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• 1998

Brine shrimp lethality test has become one of our routine tools in selecting plant materials for further chemical or bioactivity studies in our laboratory. Usually, once a potentially bioactive sample has been identified, it will then be subjected to more elaborate bioassay procedures. Out of more than 200 plant samples tested we found eight samples to be toxic towards brine shrimp larvae.

• Natural Product Sciences
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• 제13권4호
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• pp.355-358
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• 2007

Further bioactivity-directed fractionation of the ethanol extract of the seeds of Annona cherimolia has led to the isolation of two mono-tetrahydrofuran acetogenins, xylomaticin (1) and gonionenin (2). The structures of these compounds were characterized on the basis of chemical and spectroscopic data. Compounds 1 and 2 have a relative stereochemistry relationship of threo/trans/threo across the mono-tetrahydrofuran ring with its two flanking hydroxyls. Compounds 1 and 2 are known, but are first isolated from this plant. In brine shrimp lethality test (BST), 1 and 2 exhibited cytotoxic activity.

• 한국응용과학기술학회지
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• 제35권1호
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• pp.284-291
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• 2018

본 연구에서는 식품 및 화장품 원료로 널리 사용되는 천연 다당류의 분자 구조, 분자량, 점도, 친수성, 팽창, 습윤 및 보습 특성을 이용하여 도로 분진 방지제를 제조하였다. 다양한 분진 제어 효과가 확인되었으며 단순한 물 분사 및 시험 대조군인 합성PVA보다 우수한 결과를 얻었다. 또한 수분증발 비교, 비산 저감율, 공사현장 테스트 및 물벼룩 급성 독성 시험 등의 영향을 연구하고 토양 및 수질의 안전성을 연구하여 도로 분진 방지제의 유용성을 확인하였다.

• Toxicological Research
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• 제14권2호
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• pp.183-191
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• 1998

It has been reported that 50~70% of child asthma, bronchial asthma in adult, and allergic rhinitis are caused by house dust mite. The antigen extracted from house dust mite has been used for effective treatment against allergic diseases and for clinical test. This house dust mite antigen has been entirely imported from abroad. However, the composition and content of all the antigen imported vary from a brand to other brand. Thus, we need to standardize the composition and content of the antigen by developing it domestically. We proceeded pre-clinically general pharmacological test and toxicological test that are required for the eventual human use by utilizing the house dust mite cultured in Korea. In order to obtain information on general pharmacological tests such as its toxic signs in tissues or organs which are mainly affected, we examined the effect of house dust mite on the tensions of the isolated tissues and heart rates of cardiac muscle by recording with force displacement transducer of polygragh (Glass Model 7). We determined lethality of antigen extracted from house dust mite in mice and guinea pigs. We examined acute and subacute toxicity by administrating house dust mite extract of 500, 100, 20 times of the expected clinical dose. In male and female mice and guinea pigs, given a sigle intraperitoneal dose of antigen, $LD_{50}$ values were over 5.0 $\textrm{m}{\ell}$/kg, respectively. In animals administrated with house dust mite, there were no significant change of clinical symptom, body weight, food consumption, water consumption, eye examinations, urinalysis, blood biochemistry, and histopathological examinations in any animals tested. We found no toxic effect of this house dust mite. These results show that the house dust mite cultured by us could be used in the development of medicine against allergic diseases caused by the antigen of house dust mite.

• 대한약침학회지
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• 제18권4호
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• pp.51-58
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• 2015

Objectives: Bufonis venonum (BV) is the dried white secretions of the auricular and skin glands of the toads Bufo bufo gargarizans or Bufo melanosticus Schneider. This study was performed to evaluate the toxicity of intramuscularly-administered Bufonis venonum pharmacopuncture (BVP) and to calculate its approximate lethality through a single-dose test with Sprague-Dawley (SD) rats. Methods: Twenty male and 20 female 6-week-old SD rats were injected intramuscularly with BVP or normal saline. The animals were divided into four groups with five female and five male rats per group: the control group injected with normal saline at 0.5 mL/animal, the low-dosage group injected with 0.125 mL/animal of BVP, the medium-dosage group injected with 0.25 mL/animal of BVP and the high-dosage group injected with 0.5 mL/animal of BVP. All injections were in the left thighs of the rats. After administration, we conducted clinical observations everyday and body weight measurements on days 3, 7 and 14 after the injection. We also carried out hematology, serum biochemistry, and histological observations on day 15 after treatment. Results: No mortalities were observed in any experimental group. No significant changes in weight, hematology, serum biochemistry, and histological observations that could be attributed to the intramuscular injection of BVP were observed in any experimental group. Conclusion: Lethal dose of BVP administered via intramuscular injection in SD rats is over 0.5 mL/animal.