• Korean journal of applied entomology
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• v.41 no.2
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• pp.99-105
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• 2002

A gregarious pupal endoparasitoid Tetrastichsus sp. (Hymenoptera: Eulophidae) was reared in vitro from oviposition to adult emergence on an artificial host. The host pupal case was made using 0.02 mm-thick polypropylene film, and was filled with a diet consisting of powders of Antheraea pernyi pupa, chicken yolk, infant formula, royal jelly, and Neisenheimer's salt solution. Female parasitoids reared in the artificial host produced smaller sized progeny than those reared in in vivo, but the adults reproduced fertile offsprings. Furthermore in vitro second-generation (G$_2$) females showed more improved biological characteristics, compared with their parents. The fecundity (mean no. adult progeny), oviposition period (days), and longevity (days) of G$_2$ female were evaluated as 45.7, 7.8, and 13.8, respectively Female biased sex ratio was obtained with 76.9% female progeny. The results demonstrated that Tetrastichus sp. is a promising parasitoid for in vitro mass production.

• Journal of the korean veterinary medical association
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• v.47 no.2
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• pp.165-176
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• 2011

구제역은 우제류 동물이 걸리는 급성열성전염병으로, 본 병에 걸린 동물은 발열이나 식욕부진을 지나 병명대로 구강과 혀 점막, 발굽 주위나 유방의 피부에 수포를 형성한다. 이후 이환된 가축은 섭취 장애나 보행장애가 일어나고, 산육능력이나 비유량이 저하됨에 따른 경제동물로서의 가치를 현저하게 떨어지게 한다. 또한 본 병의 전파는 극히 빠르고 동물이나 축산물에 대하여 엄격한 이동제한이나 방역조치가 본 병의 전파나 확대를 막기 위해 실시하기 때문에 본 병에 의해 생기는 경제적 피해는 농가의 지역단위 뿐만 아니라 국가단위에도 미쳐 심각하다. 그 때문에 자유무역을 표방하는 WTO체재하에 있어서도 구제역의 만연방지를 목적으로 한 무역제한은 국제적으로 용인되어져 오고 있고, 세계동물보건기구에 의해 국가나 지역단위의 청정도 구분이 장해져 각국의 법에 반영되어져 있다. 구제역의 병원체로 있는 바이러스는 숙주역이 넓고, 적지 않은 바이러스양에도 감염이 성립, 감염동물체내에서 바이러스가 신속하게 복제, 감염동물로부터 다량의 바이러스가 배설, 접촉전파만이 아닌 공기전파를 일으킨다는 등이 본 병의 전파나 확대에 유리한 복잡한 성성을 가질 경우에 구제역의 방역 및 박멸을 어렵게 하기 때문에 수의학영역에서 가장 경계해야할 전염병의 하나이다. 따라서 본 필자는 최근의 국내 구제역 발생상황속에서 관련자료정리를 하다가 대동물 임상수의사가 알아야 부분과 일본 동물위생연구소 등에서 구제역바이러스 인공감염 및 화학물질(T-1105)투여시험 결과 내역를 정리하여 소개해두고 저 한다.

• Korean Journal of Veterinary Research
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• v.37 no.4
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• pp.785-791
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• 1997

Theileria spp.의 생활환에 대해서는 여러종류의 책을 통해서 잘 소개되어 있다. 그중 Theileria spp.의 분열소체 즉, merozoite는 주로 숙주의 적혈구내에 존재하는데 진드기에 의해 흡혈되지 않으면 더이상 발육하지 못하고 생을 마감한다고 여겨 왔다. 그러나 적혈구내 merozoite가 임파구에 다시 들어가 schizont로 복귀하여 분열 증식된다는 가설은 아직까지 증명된 바 없다. 본 실험은 T sergenti merozoite의 schizont로의 복귀를 입증하고자 수행되었다. T sergenti에 감염되지 않은 3개월령의 송아지를 비장적출시킨 후 T sergenti merozoite에 감염된 순수적혈구를 인공감염시켰다. 인공감염후 경시적으로 혈액과 임파액을 채취하여 적혈구내 T sergenti 감염을 조사하고 백혈구 감별혈구를 계산하였으며 임파구내 schizont 출현을 관찰하여 다음과 같은 결과를 얻었다. 1. 혈구내원충 감염율(parasitemia : PE)은 인공감염후 28일째 최고치인 10.5%를 보였으며 그후 5%이내의 수준을 유지하다가 70일째 다시 8.5%의 상승점을 보였다. 2. 백혈구 감별혈구계산에서는 감염초기에는 호중구가 주종을 이루다가 감염후 19일을 기점으로 임파구(60~80%)가 급격히 증가하여 실험종료 때까지 유지되었다. 3. 인공감염후 19~23일, 59~63일 사이에 말초혈액내 임파구에서 분열 증식하고 있는 schizont를 관찰할 수 있었다. 4. 인공감염후 7일부터 림프액내 임파구의 크기가 커지면서 blast-formation이 진행되었으며 실험종료때까지 유지되었다. 이상의 결과로 보아 적혈구내 merozoite가 임파구에 다시 들어가 schizont로 복귀하여 분열 증식함을 입증하여 기존의 T sergenti 생활사는 수정되어야 된다고 사료된다.

• Journal of Life Science
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• v.26 no.6
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• pp.646-650
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• 2016

The influence of chromosome number on cell growth and cell aging was investigated in various yeast strains that have many artificial chromosomes constructed using a chromosome manipulation technique. Host strain FY833 and the YKY18, YKY18R, YKY24, and YKY30 strains harboring 16 natural chromosomes, 18 chromosomes, 18 chromosomes containing rDNA chromosome, 24 chromosomes, and 30 chromosomes, respectively, were used, and the specific growth rate of each strain was compared. The specific growth rates in the YKY18 and YKY24 strains were indistinguishable from that in the host strain, while those of the YKY18R and YKY30 strains were reduced to approximately 25% and 40% of the host strain level, respectively. Subsequently, the replicative life span was examined to investigate the relationship between the number of chromosomes and cell aging, and the life span was decreased to approximately 14% and 45% of the host strain level in the YKY24 and YKY30 strains, respectively. Moreover, telomere length, well known as a senescence factor, was shorter and more diversified in the strain, showing decreased life span. Therefore, these results suggest the possibility that an increase in the number of chromosomes containing artificial chromosomes caused cell aging, and we expected these observations would be applied to improve industrial strain harboring of versatile and special artificial chromosomes.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.115-120
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• 2004

A Gram (-), rod-shaped bacterium in size of 1.3∼$1.8{\times}0.35{\mu}m$ inhibiting the growth of cyanobacterium (Ana-baena cylindrica) was isolated and designated NG-2 in this manuscript. This isolate showed positive reactions for catalase and oxidase, and optimal growth conditions of 35∼TEX>$40<^{\circ}C$ and pH 9.0. In a mixed-culture of A. cylindrica and the isolate, each microorganism grew inverse-proportionally, and the cyanobacterial vegetative cells almost completely disappeared within 24 hours. NG-2 lysed A. cylindrica only under light, which means that lytic activity of NG-2 was dependent on the photosynthetic activity of host. When observed under phase contrast microscope, the isolate lysed vegetative cells of A. cylindrica in scattered state in a liquid medium, whereas het-erocysts have not been lysed. When cyanobacterial cell walls have been lysed partly, NG-2 attatched around A. cylindrica filament and formed colony, then encouraged complete lysis of cyanobacterial cells. The isolate showed similar lytic activity in natural water as in an artificial medium. And lytic activity of NG-2 was enhanced when attached on expandable polystyrene bead.

• Korean journal of applied entomology
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• v.22 no.4 s.57
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• pp.293-299
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• 1983

Experiments were carried out to elucidate the specific interactions between host plant, Phaseolus vulgaris, and symbiotic bacteria, Rhizobium Phaseoli. Purified P. vulgaris lectins and six species of cultured Rhizobium were subjected to agglutination test. Lectins from bean and R. phaseoli showed relatively high agglutination activity indicating that host plant lectins recognize carbohydrate moieties on the compatible Rhizobium cell surface. The specific carbohydrate receptors for binding of the lectins on the cell surface of R. phaseoli were found as mannose and galactose. The minimum concentration of sugars for the inhibition was 6.25mM. The lectin content of cultured plant roots was measured after germination and was maximum in 5-day seedlings. The nodulation was competitively inhibited by lectins for the plants cultured with Rhizobium cells. By immunochemical studies, there was some relationship in antigenic determinants between R. phaseoli and R. japonicum but no relationships were observed with other Rhizobium species. The results suggest that the infection by rhizobia to the roots of leguminous plants may be caused by the specific interaction of lectins with rhizobia.

• Journal of Chest Surgery
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• v.40 no.1 s.270
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• pp.1-7
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• 2007

Backgound: It has been shown that the endothelium of cardiac valves and adjacent great vessels have a reduced immune reaction compared to other vessels. We investigated the clinical feasibility of using immunologically untreated xenogenic valves, in a pig-to-goat pulmonary valve conduit implantation model. Material and Method: Porcine pulmonary valve conduits were prepared without specific immunologic treatment and implanted into the right ventricular outflow tract of goats while undergoing cardiopulmonary bypass. Two goats each were assigned to the following observation time intervals: one day, one week, three months, six months and twelve months. Echo-cardiographic examinations were performed prior to sacrifice of the goat to evaluate pulmonary valve function. After the xenograft specimens were retrieved, histological changes were evaluated microscopically. Result: Ten of the twelve animals survived the predetermined observation time intervals. Aneurysmal dilatations, of the anterior wall of the implanted pulmonary artery, were observed at each of three and twelve month-survival animals. A variable degree of pulmonary valve regurgitation was observed on echocardiography. However, valve stenosis, thrombotic occlusion and vegetation were not seen. Microscopically, the nuclei of the donor tissue disappeared as a result of pyknosis and karyolysis; however the three components of the implanted xenografts (the pulmonary artery, the valve and the infundibulum) were gradually replaced by host cells over time, while maintaining their structural integrity. Conclusion: Immunologically untreated xenogenic pulmonary valve conduits were replaced by host cells with few observed clinical problems in a pig to goat pulmonary valve implantation model. Therefore, they might be an alternative bioprosthesis option.

• Parasites, Hosts and Diseases
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• v.27 no.1
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• pp.23-34
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• 1989

In an attempt to investigate the effect of Hymenolepis dana infection on immunological responses to sRBC in ICR strain of mice, cellular and humoral immune responses were chronologically monitored after sensitization with sRBC. Mice weighing about 20 g were allocated into artificial and natural infection groups. The shell-free eggs of H. dana were inoculated into mice on the day 0 (initial) and day 10 in the former group, and praziquantel (25 mg/kg/day) was administered for 3 days to the one half of the mice at the 15th day after the first inoculation and to all of the mice in natural infection group. In artificial infection group, the delayed-type hypersensitivity (DTH) to sRBC was considerably decreased on the day 10 after the first inoculation, and then elevated gradually to normal. Eosinophils in the peripheral blood increased slightly. The hemagglutinin (HA) and hemolysin (HE) titers during the early stage were shown to be more or less higher than those of control. Thereafter, the titers were returned to normal, followed by a transient decrease on the day 15 post-infection. The sRBC rosette and antibody-treated rosette-forming capacities on the day 15 post.infection were temporarily lowered but became higher thereafter. The mucosal mast cells (MMC) in the small intestine were gradually increased to make a peak on the day 10 post-infection and then maintained more or less at lower level. After praziquantel treatment, the DTH and the number of eosinophils were decreased slightly and the MMC number and sRBC rosette-forming capacity were considerably decreased. The titers of HA and HE and antibody-treated rosette-forming capacity, however, were elevated in general. In natural infection group, the DTH, the number of eosinophils, and MMC which were elevated due to H. dana infection were gradually returned to normal after prasiquantel treatment. The titers of HA and HE which were decreased by parasite infection were increased to normal after the treatment. However, the capacities of sRBC rosette or antibody-treated rosette formation were maintained at low levels in spite of the treatment. These results revealed that the immune responses to sRBC were significantly activated during H. dana infection, although they were transiently decreased during the days 10~15 post-infection.

• Journal of Mushroom
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• v.2 no.3
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• pp.149-156
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• 2004

This study was carried out to obtain basic data on physiological characteristics for an artificial cultivation of fruiting body of Cordyceps. Specimens such as Cordyceps longissima, C. militaris and C. pruinosa were collected at Mt. Halla of Cheju island in July, 2003. Among four different culture media which have been used for culture of mushrooms, MCM medium was selected for the favorable culture medium of the Cordyceps tested. The initial pH of solid medium for mycelial growth of Cordyceps was good in the range of pH 5.0~7.0 lower than 8.0. The mycelial growth of C. longissima was most favorable on culture media supplemented with glucose, one of monosaccharides. In C. militaris, nine carbon sources were favorable to the mycelial growth as compared with control among 11 carbon sources. Six nitrogen sources were favorable to the mycelial growth of C. longissima as compared with control among 9 carbon sources; namely, the mycelial growth of C. longissima was most favorable on culture media contained potassium nitrate, and followed in order by ammonium citrate and sodium nitrate in 4 weeks incubation.

• Parasites, Hosts and Diseases
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• v.21 no.1
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• pp.58-74
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• 1983

요꼬가와흡충을 수감염시켰을 태의 탕병증을 관찰하고자 은어로부터 분리한 피예유충을 모두 20마리의 개를 복용하여 인공감염 실험을 실시하였다. 이들 개를 대조군, 감염군, 재감염군으로 나눈 다음 18마리의 개에 10,000개씩 피설유충을 일차감염시켜 그중 5마리는 5일, 1주, 4주 및 6주에 도살하였으며 9주후에 다시 5,000개의 피예유충을 먹인 재감락수의 개 13마리는 1일, 3일, 5일, 1주, 2주, 4주, 6주 및 8주에 각각 도살하였다. 일차감염군과 재감염군에 있어서 충체회수률과 분포를 관찰하였다. 또한 이들 사병변의 소견을 호오적, 광학현미경 및 주사현미경적으로 관찰하였다. 결과를 요약하면 다음과 같다. 1. 충체회수률은 일차감염군에서 19.8%∼37.8%로 평균 충체회수률은 28.9%이었다. 한편 재감염상의 1일, 3일 및 5일에서의 미성숙 충체회수률은 6.3%∼16.3%로 평균 충체회수률은 12.9%이었으며, 성숙 충체회수률은 21.4%∼26.2%로 평균 충체회수률은 23.6%로 나타나 미성숙충체와 성숙충체 회수률의 비는 1 : 1.83이었다. 충체의 기생부위는 일차감염군에서 십이지장, 공장 및 회장상부에 한정되었으나 재감염군에서는 회장하부까지 연장되었다. 2. 상한적 병리소견으로 장관의 확장, 가로주름의 소실, 개수상의 장내용물, 장막림프절 및 Peyer씨 림프조직의 고대가 일차감영군의 5일 및 1주에 나타났으나 4주후에는 거의 소실되었다. 재감염군에서도 이들 소견이 초기에 나타났으나 일차감염군과 비교하면 그 소견이 농징하였으며 2주후에는 소실되었다. 3. 현징경적 병리소견으로 초기의 병변은 소정막에 국한되었으며 선와상피의 비후를 동반한 융모위축과 기질와 변화, 염증세계침윤 및 부종형성이 관찰되었다. 한편 재감염군에 있어서 정막 특히 섬모의 변화는 일차감염군과 비교할 때 그 소견이 경미하였다. 4. 주사현미경적으로 일차감염군에 있어서 섬모위축이 재확인되었으며 융모사이에서 충체를 발견할 수 있었다. 6주후에는 섬모가 거의 정상상태로 회복되었다. 그러나 재감량변에서 융모변화는 그 정도가 심하지 않았다. 이상의 결과에서 소위 자가치유 또는 자연치유 현상은 개의 요꼬가와흡충의 일차감염군과 재감염군에서 나타나지 않았다. 장병변의 경시적 관찰을 통하여 숙주면역은 요점막 회복에 관여하는 것 같았으며 특히 미성숙충체의 Lieberkiihn씨 선준 침입이 융모의 병적 변화에 일차적 원인일 것으로 추측하였다.