• Molecules and Cells
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• 제28권3호
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• pp.209-213
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• 2009

Caenorhabditis elegans is a free living soil nematode and thus in its natural habitat, C. elegans encounters many different species of soil bacteria. Although some soil bacteria may be excellent sources of nutrition for the worm, others may be pathogenic. Thus, we undertook a study to understand how C. elegans can identify their preferred food using a simple behavioral assay. We found that there are various species of soil bacteria that C. elegans prefers in comparison to the standard laboratory E. coli strain OP50. In particular, two bacterial strains, Bacillus mycoides and Bacillus soli, were preferred strains. Interestingly, the sole feeding of these bacteria to wild type animals results in extended lifespan through the activation of the autophagic process. Further studies will be required to understand the precise mechanism controlling the behavior of identification and selection of food in C. elegans.

• Mycobiology
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• 제46권2호
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• pp.172-176
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• 2018

A new species belonging to the genus Alternaria was isolated from the necrotic leaf spots of Brassica rapa subsp. pekinensis in Yuseong district, Daejeon, Korea. It is an occasional isolate, not an etiological agent, which is morphologically similar to A. broccoli-italicae, but differs in conidial size and conidiophore shape. Phylogenetic analysis using the sequence datasets of the internal transcribed spacer (ITS) region of the rDNA, glyceraldehyde-3-phosphate dehydrogenase (gpd), and plasma membrane ATPase genes showed that it is distantly related to A. broccoli-italicae and closely related to Alternaria species in the section Pseudoalternaria, which belonged to a clade basal to the section Infectoriae. Morphologically, the species is unique because it produces solitary conidia or conidial chains (two units), unlike the four members in the section Pseudoalternaria that produce conidia as short branched chains. It exhibits weak pathogenicity in the host plant. This report includes the description and illustration of A. brassicifolii as a new species.

• 한국발생생물학회지:발생과생식
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• 제2권2호
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• pp.115-133
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• 1998

지난 반세기 동안내분비 장애물질의 제한없는 생산과 무분별한 소비, 방출, 폐기는 물, 흙, 공기 등 자연을 오염시켜 왔다. 그 결과 생태계의 야생동물이 오염되어, 생식과 발생의 이상이 일어나고, 멸종이 예견되기에 이르렀다. 또한 동물 자신은 물론, 후세대에 내분비계의 교란을 일으켜 정상적인 성생활, 발생과 생식의 기형, 정자수 감소 등의 불임유발, 성행동, 신경계와 면역계의 이상, 암까지 유발하는 것으로 알려지고 있다. 암이 개체의 사멸을 일으키는 반면, 내분비 장애물질은 체내에 잔류되며 대를 이어 전달되고, 사멸하여도 환경의 오염원이 되어 먹이사슬로 축적된다는 의미에서 야생동물은 물론 인간의 미래를 어둡게 만든다고 판단되고 있다. 그러므로 이들이 야생동물의 생식과 발생에 미치는 영향, 먹이사슬내의 이동 및 오염 확산을 개관하고자 하였다. 또한 이에 대처하기 위한 국내외 연구동향을 기술하고, 또 중요한 물질의 생산 현황을 요약하고, 발생과 생식을 전공하는 연구자 제위에게 관심을 유도하고자 하였다.

• 한국환경복원기술학회지
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• 제6권6호
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• pp.29-40
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• 2003

Shindoori dune, about 2,000,000$m^2$ in area, is located in the west of the middle area in Korea. Around the sand dune, many diagnostic plants and animals are populated, so it is considered a very important ecosystematic area. This study was carried out to establish for conservation and restoration in Shindoori dune. Our surveys have been accomplished from October, 2002 to September, 2003. Plant communities formed around the sand dune in Shindoori were divided into several patterns and analysed. They have been divided into 9 communities. Community A : Carex pumila community, B : Carex kobomugi community, C : Elymus moWs community, D : Imperata cylindrica var. koenigii community, E: Rosa rugosa community, F: Ischaemum anthephoroides community, G: Vitex rotundifolia community, H : Lathyrus japonica community, I : Oenothera biennis community. The flora surveyed in these communities was constituted of 19 families, 44 genera, 8 varieties, and 40 species. Wild plants such as Calystegia soldanella, Artemisia capillaris, Avena fatua, Mertensia asiatica, Glehnia littoralis and Zoysia sinica were mostly light loving plants and higher resistant plants against the salty wind. Our result from the ranking all surveyed areas by the Bray-Curtis ordination method was very similar to the results from phytosocialogical table work.

• Biomolecules & Therapeutics
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• 제5권1호
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• pp.12-22
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• 1997

Intravenous and oral acute toxicity tests in ICR mice and SD rats and percutaneous acute toxicity tests in SD rats and NZW rabbits were conducted to evaluate the toxicity of DA-5018 and DA-5018 cream, respectively Clinical signs observed in mice and rats after the administration of DA-5018 were similar regardless of administration route. The observed clinical signs were jumping, wild running, lacrimation, ataxia, reddening of extremities and ears, ventral or lateral recumbency, respiratory distress, cyanosis, convulsion and death. Pulmonary enlargement and hemorrhage were observed in the animals died immediately after the dosing of DA-5018. At terminal necropsy, pulmonary enlargement and hemorrhage, corneal opacity and focal scabbing and depilation around nose were seen. LD$_{50}$ Values of DA-5018 are 11.5 mg/kg (mice, male), 12.6 mg/kg (mice, female), 88.3 mg/kg (rat, male) and 73.2 mg/kg (rat, female) in oral toxicity tests and 11.0 mg/kg (mice, male), 18.7 mg/kg (mice, female), 0.12 mg/kg (rat, male) and 0.32 mg/kg (rat, female) in i.v. toxicity tests. In the percutaneous acute toxicity tests of DA-5018 cream, no deaths occured in all the tested groups during 14-day observation period. There were also no abnormalities in the general conditions, body weight changes and on necropsy findings in all groups. LD$_{50}$ values of 0.1 ~0.9% DA-5018 creams in male and female rats and rabbits are >2000 mg/kg./kg.

• 대한수의학회지
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• 제58권3호
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• pp.137-141
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• 2018

The efficacy of the CA-2-MP120 vaccine, a cell culture-attenuated strain of virulent porcine reproductive and respiratory syndrome virus (PRRSV), was assessed in pigs. Despite the persistence of viremia in all vaccinated animals during the immunization period, the virus was not detected in vaccinated pigs following challenge. Furthermore, no pigs in the vaccinated group shed PRRSV nasally, orally or rectally throughout the experiment. Moreover, histopathological lung and lymph node lesions in the immunized group were much milder than those in the unimmunized and challenged group. These results indicated that CA-2-MP120 can provide effective protection against virulent wild-type PRRSV-2.

• Journal of Microbiology
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• 제40권1호
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• pp.1-10
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• 2002

At the dose of 1000 p.f.u. per mouse,100% mortality occurred in mice inoculated with wild-type pseudorabies virus (PrV). In contrast, upon stable deletion of 10 bp nucleotides at the Bsrl site within the TK gene, PrV was rendered to be completely apathogenic. The deletion also caused the virus to be less capable of replicating in respiratory as well as in nervous system tissues. Although animals were exposed to high titers of TK-deleted PrVs, the virus failed to replicate to a high titer as compared to the pathogenic parental virus. In contrast to previous studies the deletion in the TK gene did not prevent the virus from establishing latency. Upon immunosuppression, the latent virus? however, reactivated but replicated at low titers. Interestingly, TK-deleted virus established latency and reactivation, that are occurred only in trigeminal ganglia and the cerebrums and no other tissues involved. Following reactivation, there was no indication of virus shedding in respiratory tissues as confirmed by virus isolation and polymerase chain reaction (PCR) technique targeting at the gB gene of PrV, The non-pathogenic virus with non-shedding characteristics, upon reactivation of the latent virus, would be the important feature of a live virus vaccine candidate.

• Clinical and Experimental Pediatrics
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• 제53권5호
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• pp.653-656
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• 2010

$Listeria$ $monocytogenes$ is a facultative anaerobic, gram-positive bacillus that is isolated from the soil, vegetables, and wild or domestic animals. Listeria occurs predominantly in the elderly, immunocompromised patients, pregnant women and newborns. Infections by this microorganism are rare in healthy infants and children. $L.$ $monocytogenes$ may cause meningitis, meningoencephalitis, brain abscess, pyogenic arthritis, osteomyelitis, and liver abscesses in children. The course of meningoencephalitis by listeria is often severe and even fatal. Acute hydrocephalus can develop as a complication and the mortality associated with listeriosis is significantly high. We present a case of meningoencephalitis caused by $L.$ $monocytogenes$ in a previously healthy 7-year-old girl.

• Toxicological Research
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• 제17권
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• pp.309-312
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• 2001

It has recently been suggested that the release of "endocrine disrupters (EDs)" into the environment has resulted in adverse health effects on wild life populations and humans (Golden et al., 1998; Tyler et al., 1998; Kang et al., 2000). Human sperm counts have declined significantly throughout the world during the past fifty years, and which is a significant public health concern (Carlsen et al., 1992; Carlsen et al.. 1995). In addition, the EDs persisting in the environment are known to disrupt the normal endocrine systems of wildlife (Colborn, 1995; Crewet al., 1995; Folmer et at, 1996; Sumpter, 1995; Tyler, 1998). Some estrogenic chemicals bind to estrogen receptors (Bolger et al.. 1998), interfere with the binding of physiological ligands to steroid hormone-binding proteins (Danjo, 1997; Milligan et al., 1998). and show immunotoxicity (Sakae et al., 1998). (omitted) (omitted)

• 한국임상수의학회지
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• 제25권4호
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• pp.310-313
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• 2008

C. perfringens is the most important enteric clostridial pathogen of animals. C. perfringens type A has been associated with hemorrhagic enteritis in a wide lange of domestic and wild mammals. But all types of C. perfringens can be normal inhabitants of the intestine of most mammals. We have a special case that showed C. perfringens type A infection in a hippopotamus (Hippopotamus amphibius) cub at Seoul Grand Park Zoo. Male, hippopotamus cub died in 3 days after birth. Clinical features of the hippopotamus cub have showed lethargy and anorexia before death. Gross post-mortem findings of the hippopotamus were hemorrhagic enteritis of intestine. Histopathologically, ruminant stomach and intestine showed hemorrhagic lesions and the lumen of the small intestine was filled with mucoid and hemorrhagic fluid. Also, intestine and stomach of hippopotamus were distended with gas and hemorrhagic fluid. C. perfringens was isolated in culture of small intestine and the presence of C. perfringens type A was confirmed by PCR. This case indicated that C. perfringens type A could be considered as a virulence factor responsible for causing death of a newborn hippopotamus.