• 농약과학회지
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• 제3권2호
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• pp.60-68
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• 1999

충남 공주지방의 강변 잔디밭에서 검출된 곤충병원성 선충 Steinernema longicaudum 공주계통의 병원성과 증식에 미치는 온도와 접종농도의 영향을 알아보았다. 꿀벌부채명나방 유충 한 마리당 선충을 5, 10, 20, 40, 80, 160마리 농도로 처리하여 13, 18, 24, $30^{\circ}C$의 항온기에 보관하면서 14일간 치사율과 치사소요일수를 조사하였고, 동일 온도에서 30일 동안 감염태 유충의 증식수와 증식기간을 조사하였다. 그 결과 온도와 농도가 높을수록 병원성이 높게 나타났지만 농도보다는 온도에 의하여 더 많은 영향을 받았다. 즉, $13^{\circ}C$에서는 모든 농도에서 치사율이 낮았으나 $24^{\circ}C$와 $30^{\circ}C$에서는 5마리와 10마리의 낮은 농도에서도 높은 치사율을 나타내었다. 온도와 농도가 높아질수록 치사일수도 단축되어 $24^{\circ}C$와 $30^{\circ}C$에서 160마리 농도는 2일만에 기주를 100% 치사시켰으나, 5마리 농도는 $24^{\circ}C$에서 10일만에 83.3%, $30^{\circ}C$에서 6일만에 90%의 기주 치사율을 나타내었다. 유충의 증식은 온도와 농도가 높아짐에 따라 양호한 경향이었지만 접종농도간에는 유의성이 인정되지 않았다. 저온인 $13^{\circ}C$에서는 모든 농도에서 전혀 증식이 이루어지지 않았다. 증식기간도 $30^{\circ}C$에서 $6{\sim}9$일로 다른 온도와 비교하여 가장 짧았다. S. longicaudum 공주계통의 병원성 발현 최적 온도는 $24^{\circ}C$였고 증식 최적 온도는 $30^{\circ}C$였다.

• 생명과학회지
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• 제16권5호
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• pp.729-733
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• 2006

크립토스포리디움의 활성 및 감염성 판정을 위해 Direct RT-PCR, 세포배양 후 RT-PCR 및 면역형광염색법을 비교한 결과는 다음과 같다. 1) 크립토스포리디움의 HSP70 gene에 대해 direct RT-PCR한 결과, 민감도가 매우 높아 저농도로 존재하는 환경시료에서의 크립토스포리디움 활성을 모니터링하는데 장점이 있을 것으로 보이나, 감염성의 판정은 알 수 없으며, 정량화가 안되는 단점이 있었다. 2) ${\beta}-tubulin$ gene에 대해 RT-nested PCR을 한 결과 크립 토스포리디움의 난포낭이 $1{\times}10^4$ 세포수정도 되어야 검출이 되는 것으로 나타나 HSP70 gene에 대한 RT-PCR결과와 비교할 때 10,000배 이상 민감도가 떨어지는 것으로 나타났다. 3) 세포배양 후 RT-PCR 또는 면역형광염색법을 이용할 경우에는 민감도가 direct RT-PCR보다 다소 떨어지는 단점이 있었으나 크립토스포리디움의 오염원이나 오염이 심한 지역의 감염성 조사에 적합할 것으로 나타났으나, 정량화가 필요한 경우에는 세포배양 후 면역형광염색법이 효과적일 것으로 나타났다.

• 대한약학회:학술대회논문집
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• 대한약학회 2000년도 춘계총회 및 학술대회
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• pp.153.2-154
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• 2000

• 한국잠사곤충학회지
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• 제33권1호
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• pp.27-31
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• 1991

노랑테불나방과 숯검은밤나방으로부터 미포자충을 분리하고 이들의 형태적인 성상과 누에에 대한 감염성을 조사하였다. 1. 노랑테불나방과 숯검은밤나방 외 6종의 야외곤충으로부터 8종의 미포자충이 분리되었으며 노랑테불나방와 숯검은밤나방으로부터 분리된 미포자충들의 크기는 각각 2.6$\mu$$\times$1.5$\mu$, 3.8$\mu$$\times$2.0$\mu$였다. 2. 노랑테불나방과 숯검은밤나방으로부터 분리된 미포자충들은 누에에 감염성을 나타냈으나 벼잎벌레로부터 분리된 미포자충은 누에에 감염성을 나타내지 않았다. 3. 노랑테불나방과 숯검은밤나방으로부터 분리된 미포자충들은 누에에 있어서 경란전달 전염은 되지 않았으나 노랑테불나방에 감연된 누에 나방이의 산란수도 적고 상태도 불규칙적이었다.

• The Plant Pathology Journal
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• 제15권1호
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• pp.38-43
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• 1999

Mutants of the monopartite geminivirus beet curly top virus (BCTV) have been screened for infectivity, systemic movement, replication and symptom development in Arabidopsis thaliana. As known by coding for coat protein, R1 mutant was not infectious and did not move systemically. R2, R3 and L2/L3 mutants produced milder symptoms compared to wild type BCTV but the infectivity was reduced by 40% to 60%. R2 ORF is thought to be involved in the regulation of ssDNA and dsDNA accumulation because only dsDNA was accumulated on R2-infected organs. Disruption of ORF L4 resulted in reduced infections, but the viral DNA was accumulated in infected organs from roots to shoot tips as much as wild type BCTV on Sei-O. In addition, 4 mutants did not produce callus-like tissues on infected organs, suggesting that L4 ORF may play a role in the induction of host cell divisions by virus infection. This result was supported by the patterns of mRNA expression and promoter analysis of the cell cycle marker gene, cycl, on Arabidopsis. cycl mRNA was accumulated on symptomatic organs by wild type BCTV infections but not by L4 mutant. We conclude that the BCTV L4 ORF is essential for symptom developments, specially callus-like formation on infected organs.

• BMB Reports
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• 제48권2호
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• pp.121-126
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• 2015

Here we report a new chemical inhibitor against HIV-1 with a novel structure and mode of action. The inhibitor, designated as A1836, inhibited HIV-1 replication and virus production with a 50% inhibitory concentration ($IC_{50}$) of $2.0{\mu}M$ in an MT-4 cell-based and cytopathic protection antiviral assay, while its 50% cytotoxic concentration ($CC_{50}$) was much higher than $50{\mu}M$. Examination of the effect of A1836 on in vitro HIV-1 reverse transcriptase (RT) and integrase showed that neither were molecular targets of A1836. The characterization and re-infection assay of the HIV-1 virions generated in the presence of A1836 showed that the synthesis of early RT products in the cells infected with the virions was inhibited dose-dependently, due in part to abnormal protein formation within the virions, thus resulting in an impaired infectivity. These results suggest that A1836 might be a novel candidate for the development of a new type of HIV-1 inhibitor.

• 한국자기공명학회논문지
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• 제2권2호
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• pp.85-105
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• 1998

Prions cause neurodegenerative diseases in animals and humans. The scrapie prion protein (PrPSc) is the major-possibly only-component of the infectious prion and is generated from the cellular isoform (PrPC) by a conformational change. Limited proteolysis of PrPSc produces an polypeptide comprised primarily of residues 90 to 231, which retains infectivity. The three-dimensional structure of rPrP(90-231), a recombinant protein resembling PrPC with the Syrian hamster (SHa) sequence, was solved using multidimensional NMR. Low-resolution structures of rPrP(90-231), synthetic peptides up to 56 residues, a longer (29-231, full-length) protein with SHa sequence, and a short here further structure refinement of rPrP(90-231) and dynamic features of the protein. Consideration of these features in the context of published data suggests regions of conformational heterogeneity, structural elements involved in the PrPC\longrightarrowPrPSc transformation, and possible structural features related to a species barrier to transmission of prion diseases.

• 미생물학회지
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• 제30권6호
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• pp.524-527
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• 1992

경기도 의왕시에 위치한 백운 저수지에서 분리된 cyanobacteria 인 Synechococcus sp. 로부터 한 종의 cyanophage 를 분리하여 ultrafiltration, differential centrifugation 과 sucrose density gradient centrifugation 을 이용하여 정제하였다. 분리된 cynophage 는 transmission electron microscope (TEM) 를 이용하여 100,000 배로 관찰한 결과 직경이 89 nm인 isometric head 와 tail 의 전체 길이가 111 nm 의 contractile tail 을 가진 phage 로서 Myoviridae 에 속함을 알 수 있었다. 생화학적 특징으로는 20~$40^{\circ}C$ 와 pH 5-10에서 50% 이상의 안정성을 유지하며 $30^{\circ}C$ 와 pH 9 에서 최고의 infectivity 를 나타내었다.

• 한국환경보건학회지
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• 제32권4호
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• pp.336-341
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• 2006

The biological wastewater treatment system is known to have an important role in reducing the quantify of enteric virus in water environments. To clarify the roles of activated sludge microbes in decreasing the virus infectivity, the behavior of the virus in bacteria, protozoa, and metazoa was examined by pure or mixed culture system using poliovirus type 1(Lsc, 2ab strain). In the bacterial culture systems, the virus infectivity in the liquid phase decreased by a reversible adsorption of the virus to the bacteria or bacterial flocs. On the other hand, in the protozoa and the metazoa culture systems using T. pyriformis and P. erythrophthalma, respectively, with a variety of bacterial strains as prey, the main virus decrease mechanism of reversible adsorption in early stage was changed to irreversible predation, which was not eluted in this study. The virus decrease was more effective in the P. erythrophthalma culture system, which had high predation and floc forming abilities. However, in the mixed culture system of Z. ramigera and P. erythrophthalma, the more rapid reversible adsorption of virus to Z. ramigera flocs preceded the irreversible predation of P. erythrophthalma.

• 대한미생물학회지
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• 제16권1호
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• pp.83-89
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• 1981

Japanese encephalitis has been prevalent for long time in the Far East and many patients have been reported in both South East and Mid-West Asia recently. Recently, vaccine was used in prevention of this viral disease of man which was derived from formalin inactivated virus inoculated into mouse brain, but live attenuated active vaccine for human is not developed yet. Author inoculated Japanese encephalitis virus into several cell culture strains for development of live attenuated encephalitis virus strain and the results were as follows: 1. Japanese encephalitis virus was inactivated rapidly in cell free medium at $36^{\circ}C$ and totally inactivated by 72 hours. 2. In growth curve of Japanese encephalitis virus in HeLa cell cultures, maximal multiplication of the virus was occured at 4th day and virus multiplication was continued for at least 12 days. 3. After succeeding passage of the virus in HeLa cell cultures and human esophagus epithelial cell cultures, infectivity of virus for mice was disappeared from 2nd passage in HeLa cell cultures and 3rd passage in esophagus epithelial cell cultures. 4. In inoculation to monkey kidney epithelial cells and chick embryo cell cultures, infectivity of the virus for mice was continued after 10th passages.