• 한국산업보건학회지
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• 제21권2호
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• pp.82-89
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• 2011

Methylcyclohexane is frequently used in industrial sites (2,592tons/year) as rubber adhesives, ink, paint thinners, organic solvents, and so on. However, there are limited data on the toxic evaluation of methylcyclohexane. This study aims to predict the hazards and neurological effects of methylcyclohexane using SD rats in order to prevent health disorders of workers. The OECD Guideline for Testing of Chemicals (OECD, 2001) was used as a reference during the tests. For 13 weeks (once a day, five days per week) 0, 10, 100 and 1,000mg/kg/day of methylcyclohexane was injected to SD rats to observe any changes in the body or organ weight, hematology, histopathology, mobility, blood pressure, and neurotransmitter. As a result, some male and female SD rats injected with 1,000mg/kg/day of methylcyclohexane died. On the other hand, surviving rats showed significant changes such as hematological changes involving the decrease in the number of red blood corpuscles, and the decrease or increase in the weight of the lungs, kidneys, spleens, and livers (p< 0.05, p<0.01). Also histopathological lesions were observed in the hearts and kidneys. In the test for the effect on the nervous system, SD rats injected with 100mg/kg/day of methylcyclohexane had higher blood pressure levels compared to the control group. However, no abnormal effects was observed in the mobility, serotonin, neurotransmitter, and the biopsy of the brain and coronary arteries. The study results revealed that the livers, hearts, and kidneys were affected by methylcyclohexane. The absolute toxic dose of methylcyclohexane is 1,000mg/kg/day, NOAEL is 100 mg/kg/day, and it is not a toxic substance to the nervous system.

• 대한약침학회지
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• 제23권4호
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• pp.212-219
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• 2020

Objectives: Nowadays cancer treatment is an important challenge in the medical world that needs better therapies. Many active secretions produced by insects such as honey bees used to discover new anticancer drugs. Bee venom (BV) has a potent anti inflammatory, anti cancer and tumor effects. The aim of present study is evaluation of anticancer effects induced by Apis mellifera venom (AmV) on cell Lines. Methods: AmV was selected for study on cancer cell lines. Total protein, molecular weight and LD50 of crude venom were determined. Then, cells were grown in Dulbecco's Modified Eagle medium supplemented with 10% fetal bovine serum and 1% antibiotics. The A549, HeLa and MDA-MB-231 cell Lines were exposed by different concentration of AmV. The morphology of cells was determined and cell viability was studed by MTT assay. Evaluation of cell death was determined by and DNA fragmentation. Results: The results from MTT assay showed that 3.125 ㎍/mL of A549, 12.5 for HeLa and 6.25 ㎍/mL of MDA-MB-231 killed 50% of cells (p < 0.05). Morphological analysis and the results from hoescht staining and DNA fragmentation indicated that cell death induced by AmV was significantly apoptosis. Conclusion: The data showed that using lower dosage of AmV during treatment period cause inhibition of proliferation in time and dose dependant manner. Findings indicated that some ingredients of AmV have anticancer effects and with further investigation it can be used in production of anticancer drugs.

• Journal of Veterinary Science
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• 제21권6호
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• pp.88.1-88.13
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• 2020

Background: Listeria monocytogenes is a gram-positive bacterium that causes listeriosis mainly in immunocompromised hosts. It can also cause foodborne outbreaks and has the ability to adapt to various environments. Peptide uptake in gram-positive bacteria is enabled by oligopeptide permeases (Opp) in a process that depends on ATP hydrolysis by OppD and F. Previously a putative protein Lmo2193 was predicted to be OppD, but little is known about the role of OppD in major processes of L. monocytogenes, such as growth, virulence, and biofilm formation. Objectives: To determine whether the virulence traits of L. monocytogenes are related to OppD. Methods: In this study, Lmo2193 gene deletion and complementation strains of L. monocytogenes were generated and compared with a wild-type strain for the following: adhesiveness, invasion ability, intracellular survival, proliferation, 50% lethal dose (LD₅₀) to mice, and the amount bacteria in the mouse liver, spleen, and brain. Results: The results showed that virulence of the deletion strain was 1.34 and 0.5 orders of magnitude higher than that of the wild-type and complementation strains, respectively. The function of Lmo2193 was predicted and verified as OppD from the ATPase superfamily. Deletion of lmo2193 affected the normal growth of L. monocytogenes, reduced its virulence in cells and mice, and affected its ability to form biofilms. Conclusions: Deletion of the oligopeptide transporter Lmo2193 decreases the virulence of L. monocytogenes. These effects may be related to OppD's function, which provides a new perspective on the regulation of oligopeptide transporters in L. monocytogenes.

• Journal of Microbiology and Biotechnology
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• 제33권2호
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• pp.167-179
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• 2023

The rifampicin-resistant strain E9-302 of Edwardsiella ictaluri strain 669 (WT) was generated by continuous passage on BHI agar plates containing increasing concentrations of rifampicin. E9-302 was attenuated significantly by 119 times to zebrafish Danio rerio compared to WT in terms of the 50% lethal dose (LD₅₀). Zebrafish vaccinated with E9-302 via intraperitoneal (IP) injection at a dose of 1 × 10³ CFU/fish had relative percentage survival (RPS) rates of 85.7% when challenged with wild-type E. ictaluri via IP 14 days post-vaccination (dpv). After 14 days of primary vaccination with E9-302 via immersion (IM) at a dose of 4 × 10⁷ CFU/ml, a booster IM vaccination with E9-302 at a dose of 2 × 10⁷ CFU/ml exhibited 65.2% RPS against challenge with wild-type E. ictaluri via IP 7 days later. These results indicated that the rifampicin-resistant attenuated strain E9-302 had potential as a live vaccine against E. ictaluri infection. A previously unreported amino acid site change at position 142 of the RNA polymerase (RNAP) β subunit encoded by the gene rpoB associated with rifampicin resistance was identified. Analysis of the whole-genome sequencing results revealed multiple missense mutations in the virulence-related genes esrB and sspH2 in E9-302 compared with WT, and a 189 bp mismatch in one gene, whose coding product was highly homologous to glycosyltransferase family 39 protein. This study preliminarily explored the molecular mechanism underlying the virulence attenuation of rifampicin-resistant strain E9-302 and provided a new target for the subsequent study of the pathogenic mechanism of E. ictaluri.

• 한국식품과학회지
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• 제41권5호
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• pp.560-565
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• 2009

Lactobacillus casei KCTC 2180 및 Lact. plantarum KCTC 3103으로 발효된 한국산 겨우살이 추출물인 FKM-110의 렉틴 성분의 함량 변화, 독성 및 면역증강 효과를 검토하여 다음과 같은 결과를 얻었다. 두 가지 유산균을 이용하여 KM-110을 1-3일간 발효시킨 결과, 렉틴 성분은 발효 전에 비하여 53-71% 정도의 함량을 나타냄으로서 감소되는 경향을 보였다. 마우스에 대한 시료의 독성시험을 위하여 각 시료를 피하 주사하고 $LD_{50}$ 값을 측정한 결과, KM-110은 50-100 mg/kg인 반면 유산균으로 발효된 겨우살이 추출물인 FKM-110은 150-200 mg/kg인 결과를 보임으로 발효에 의하여 in vivo 독성효과는 감소하는 경향을 보였다. 각 시료를 macrphage에 직접 자극하여 염증성 cytokine인 IL-$1{\beta}$ 및 TNF-${\alpha}$의 생산능력을 조사한 결과, FKM-110이 KM-110에 비하여 낮은 cytokine의 생산양식을 나타냈다. 그러나 FKM-110의 항원 KLH에 대한 면역증가 효과를 항체 생산능으로 조사한 결과, KM-110과 차이 없이 항원 단독 투여군에 비하여 높은 역가의 항체가 생산되었다. 따라서 겨우살이 추출물을 유산균으로 발효시킨 결과, in vivo 독성은 감소하였으나 면역증강 활성은 KM-110과 동일하게 유지되는 결과를 얻었다. 따라서 겨우살이의 면역증강 활성에 관여하는 성분으로 렉틴 이외에 물질이 관여할 수 있음을 강하게 시사하였다.

• Current Research on Agriculture and Life Sciences
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• 제6권
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• pp.171-180
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• 1988

parathion을 rat의 복강내에 매 3일 마다 20회 반복적으로 주사 했을때, 일정한 농도의 parathion을 주사한 rat와 점진적으로 주사량을 증가 시켰을때 rat의 독성정도, 혈액 및 신경조직내 cholinesterase 활성 변화, 혈액내 urea nitrogen 및 creatinine의 함량을 측정한 결과 다음과 같은 성적을 얻었다. 복강내 주사시 rat에 대한 parathion의 $LD_{50}$는 10.5mg/kg였으며 95% 신뢰한계는 6.6~16.8mg/kg였다. 아급성 독성실험에서는 A군이 50%의 폐사율을 보인데 비하여 B군과 C군에서 각각 57% 및 83%의 폐사율을 보여 parathion에 대한 축적효과가 나타났으며 증체량 측정에서도 A군에서 123 g의 증체량을 보인데 비하여 B군과 C군에서 각각 60.7 g, 및 88.4 g 의 증체량을 보여 parathion 투여군에서 체중 증가량이 감소하였다. 혈장내 cholinesterase 활성도는 A군($0.58U/m{\ell}$)에 비해 B군($0.47U/m{\ell}$)과 C군($0.36U/m{\ell}$)에서 각각 19%, 및 38%의 억제를 보였고 AA군($0.31U/m{\ell}$), BB군($0.26U/m{\ell}$) 및 CC군($0.17U/m{\ell}$)에서도 A군에 비해 각각 47%, 55%, 71%까지 유의성(P<.05)있는 감소를 보였다. 척수내 cholinesterase 활성도는 A군(2.484U/g)에 비해 B군(1.87U/g)과 C군(1.29U/g)에서 각각 25%, 및 48%의 억제를 보였고 AA군(1.27U/g), BB군(0.71U/g) 및 CC군(0.25U/g)에서도 A군에 비하여 각각 49%, 71%, 및 90%의 유의성(P<.01)있는 억제를 보였다. 뇌의 cholinesterase 활성도에서는 A군(4.67U/g)에 비해 B군(2.52U/g)과 C군(1.32U1U/g)에서 각각 46%, 및 72%로 억제 되었고 AA군(2.48U/g), BB군(1.08U/g) 및 CC군(0.51U/g)에서는 A군에 비해 각각 47%, 77%, 89%까지 유의성(P<.01)있게 억제되는 축적효과를 보였다. 비단백 질소 화합물이 urea nitrogen과 creatinine 함량은 A군에서 각각 $39.8mg/d{\ell}$와 $1.15mg/d{\ell}$인데 비하여 B군($40.9mg/d{\ell}$, $0.90mg/d{\ell}$) 및 C군($41.4mg/d{\ell}$, $1.08mg/d{\ell}$)에서 유의성 있는 차이를 보이지 않았으나 urea nitrogen 함량은 A군에 비해 B군과 C군에서 다소 증가하는 경향을 보였다.

• 농약과학회지
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• 제13권1호
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• pp.39-44
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• 2009

벼농사용 살충제인 fipronil의 비의도적 노출에 의한 꿀벌(Apis mellifera L.)의 피해를 확인하기 위해 급성독성시험, 엽상잔류독성시험, cage를 이용한 소규모야외시험을 실시하였다. 급성접촉독성시험에서 24시간과 48시간의 $LD_{50}$은 각각 0.008, $0.005{\mu}g$ a.i./bee 로 꿀벌에 매우 강한 급성독성을 보였으며 급성위해지수(QHc)는 12,500으로 매우 높은 수준이었다. 엽상잔류독성시험에서는 피프로닐 액상수화제 살포 후 28일까지 90%이상 치사율을 보여 장기간 꿀벌에 독성이 있음을 알 수 있었다. 이때 fipronil의 표면부착잔류량(dislodgeable foliar residue)을 분석한 결과 $DT_{50}$은 9일, $DT_{90}$은 31일이었다. 야외시험의 결과에서도 28일의 치사율이 40%로 조사되어 실내 엽상잔류독성시험과 유사한 잔류독성을 보였다. 이상의 결과를 종합하면 fipronil은 꿀벌에 대한 급성독성이 매우 강하면서 장기간의 잔류독성이 있어 잎 표면의 매우 낮은 잔류량으로 꿀벌에 피해를 줄 가능성이 매우 높은 살충제이다. 따라서 재배작물뿐만 아니라 살포지역 인근의 밀원식물에 약제살포시 바람에 날려 오염될 경우 화분매개용 꿀벌과 자연생태계 유용곤충에 위해가능성이 매우 높기 때문에 꿀벌이 왕성한 활동을 하는 시기에는 야외살포를 금지하여야 하며, 궁극적으로 야외생태계 유용곤충을 보호하기 위해서는 실내사용 목적으로만 사용되도록 제한해야 할 것으로 판단된다.

• 한국식품과학회지
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• 제40권1호
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• pp.106-110
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• 2008

굼벵이 유래 밀리타리스 동충하초 열수추출물(CMPD extract)의 안전성 자료를 확보하기 위하여 단회경구투여 독성시험을 실시하였으며, $CCl_4$의 경구투여로 유도된 간손상 실험동물모델로부터 시험물질(CMPD extract)의 간보호효과를 확인하였다. 단회경구투여 독성시험결과, 시험물질(CMPD extract)의 최고농도(2,000mg/kg body weight)에서 독성을 나타내지 않아 $LD_{50}$ 값을 그 이상으로 결정하였다. 또한 독성물질($CCl_4$)로부터 간손상이 유발된 SD rat에 시험물질(CMPD extract)을 투여한 후 혈청으로부터 간손상과 관련한 지표물질인 GOT, GPT, TG, TC, LDL 및 HDL 활성도를 측정하였으며, 이와 함께 병리조직학적 소견을 확인하였다. 혈청 GOT는 손상군(G2)에 비해 G4, G5 시험물질투여군에서 유의한 감소를 나타내었으며, GPT의 경우 고용량 시험물질 투여군(G4)에서 유의한 감소를 나타내었다(p < 0.05). 또한 LDL 및 HDL 활성도는 손상군(G2)에 비해 유의하지는 않지만 시험 물질투여군(G4, G5, G6)에서 어느 정도 회복기미를 보였다. 병리조직학적 소견에서도 손상군(G2)의 경우 심각한 세포독성을 보였으나, 시험물질 고용량 투여군(G4)에서는 손상된 세포가 감소하였음을 확인하였다. 이상의 결과들은 굼벵이 유래 밀리타리스 동충하초 열수추출물(CMPD extract)이 $CCl_4$ 투여에 의해 유발된 급성간 손상에 대하여 간조직의 보호와 간세포의 기능유지에 유효한 물질임을 제시 하고 있다.

• Biomolecules & Therapeutics
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• 제5권1호
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• pp.100-105
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• 1997

DW-166HC ($^{166}$Holmium-chitosan) is a complex of $^{166}$Ho, $\beta$- and $\gamma$-ray emitter, and chitosan, a polymer of glucosamine, with radiotherapeutic potential. The current study was performed to determine the acute toxicities of $^{165}$Ho-chitosan in mice by two different routes of administration. The both sex mice were given a single intravenous bolus injection of $^{165}$Ho-chitosan complex at doses of 12, 10, 6, 5 and 4 mg/kg or subcutaneous administration at doses of 600, 500, 400 and 300 mg/kg. Chitosan was dosed to control animals as 16 and 800 mg/kg, intravenously and subcutaneously, respectively. The doses of $_{165}$Ho-chitosan complex were expressed as $_{165}$holmium nitrate pentahydrate and the ratio of $^{165}$Ho$(NO_3)_3$).$5H_2O$ to chitosan was 3/4 Severe convulsion and respiratory failure were followed by death within 10 min after intravenous dosing. Transient unilateral hindlimb hypokinesias were found in two mice of 5 mg/kg dosing group during the study period. No abnormalities were observed during the necropsy of survived animals in intravenous dosing group. Only one male animal was found dead in 500 mg/kg subcutaneously dosed group. Alopecia with or without cutaneous ulcer were found in most mice including control animals. During necropsy, omental adhesion was observed in all dose ranges and enlarged spleen was found in several animals including control group. It is suggested that the acute intravenous >).$LD_{50}s$ for male and female mice were 4.90 and 6.03 mg/kg, respectively. The lowest lethal dose in male was 500 mg/kg by subcutaneous administration.

• 한국축산식품학회지
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• 제32권2호
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• pp.133-141
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• 2012

This study was carried out to investigate the effects of substitution of fermented king oyster mushroom (P. eryngii) by-products diet on pork meat quality characteristics, during the storage. A mixture of 40% king oyster mushroom by-products, 28% soybean meal and 20% corn was fermented for 10 d, and the basal diet was then substituted by the fermented diet mixture of up to 20, 50 and 80%, respectively. A total of 96 pigs were fed experimental diet (8 pigs per pen ${\times}$ 4 diets ${\times}$ 3 replication), and eight longissiumus (LD) per treatment were collected, when each swine reached to 110 kg of body weight. The Warner-Bratzler shear forces and cooking loss were significantly lowered in the treatments, while crude protein content and water holding capacity significantly (p<0.05) increased in the treatments than in the control group. The volatile basic nitrogen (VBN), at 1 d of storage, was lower in the treatments, while texture profiles and sensory evaluation did not differ between the control and the treatments (p>0.05). The pH, thiobarbituric acid reactive substances (TBARS), VBN and meat color in all treatments were increased as storage increased. Fermented king oyster mushroom by-products diet effects on lightness (CIE $L^*$), yellowness (CIE $b^*$) and chroma were determined, when LD muscles in T2 and T3 treatments were higher (p<0.05), up to 7 d (p<0.05). Therefore, the results indicate that the substitution of the fermented king oyster mushroom by-products diet to swine diet influenced the quality of the meat and it may be an economically valuable ingredient.