• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.728-733
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• 2005

The frequency and distribution of lymphoma caused by bovine leukemia virus (BLV) infection in various organs were investigated. Lymphoma samples were obtained from slaughtered cattle or from cattle submitted to the National Veterinary Research and Quarantine Service, Korea. Thirty female Holstein-Friesian dairy cattle aged over three years with the BLV-associated lymphoma were studied. None of the Korean native cattle (Hanwoo) had lymphoma in this study however. Lymphoma tissues were gray to pink in color, soft in consistency, and bulged from the cut surface. In advanced lymphoma tissues, there was great variety in the appearance of involved structures due to hemorrhage, necrosis, and/or calcification. Neoplastic tissues were observed in lymph nodes in all lymphoma cases. Intestine (96.4%), heart (88.9%), stomach (73.1%), and diaphragm (62.5%) were frequently involved with lymphoma. However, there was no lymphoma detected in liver. Large neoplastic masses, sometimes reaching the size of over 20 cm, were found in the abdominal cavities. It is suggested that metastasis of lymphomas occurs mainly via lymph based on gross observations; neoplasia may have been initiated in the serosal surface of the lung, heart, peritoneum, and numerous hollow organs in the abdominal cavity. Also many organs in the abdominal and thoracic cavity were affected by neoplastic tissues simultaneously. Characteristics observed in this study could be used as criteria to differentiate BLV-associated lymphoma from other nodular lesions in the slaughterhouse and as fundamental data to make clear the mechanism of metastasis or pathogenesis of EBL.

• 한국동물위생학회지
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• 제21권3호
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• pp.255-260
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• 1998

Since bovine leukosis caused considerable economic loss to the dairy industry, seroepidemiologi-cal survey on bovine leukosis was carried out for the dairy herds in Kyunggi province. 1. When compared the results of immunodifussion test with those of enzyme-linked immunosorbent assay(ELISA) for 94 dairy herds sera, the relationship between the immunodifussion test and ELISA were showen high corresponding rate with sensitivity(97.5%) and specificity(92.6%). 2. In immunodiffusion test for bovine leukosis virus (BLV) antibody in 570 dairy cattle from 30 herds, mean positive rate for BLV antibody was 28.2%. The positive rate by districts were 16.5% in central, 35.4% in east, 17.3% in west, 29.1% in south, 31.6% in north, 43.7% in northeast. 3. When the results of serological studies was analyzed by age groups, the number of positive was increased gradually with the advanced in age of herds. The highest positive rate was found in the age over 6 years. 4. Of 30 dairy herds examined, 5 herds(16.7%) have no reactions against BLV antigen while 15 herds (50%) showed the range of 1∼5 positive cattle and 5 herds(16.7%), the rang of over 11 positive cattle.

• 한국동물학회:학술대회논문집
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• 한국동물학회 2000년도 한국생물과학협회 학술발표대회
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• pp.250.1-250
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• 2000

No Abstract, See Full Text

• 대한수의학회지
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• 제55권1호
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• pp.53-56
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• 2015

Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis. This study was conducted to clarify the molecular characteristics of BLVs obtained from a specific region in Korea. Proviral BLVs were detected in anti-BLV antibody-positive blood samples by PCR. Env and gag fragments were sequenced and compared to previously published reference sequences. Analysis of the env gene sequence revealed that the YI strain was highly similar to genotype 1, including United States and Japanese strains. The gag gene sequence had the highest degree of similarity with a Japanese strain.

• 한국동물위생학회지
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• 제18권1호
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• pp.1-21
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• 1995

To elucidate pathogenesis of bovine leukemia virus(BLV) in Korean native goats, the goats experimentally infected with BLV were studied especially for the aspects of infectivity and hematological changes. The experimental goats were examined for 27 months by agar-gel immunodiffusion(AGID) test and syncytium formation assay. During this period, changes of total leucocyte, absolute Iymphocyte and atypical Iymphocyte were examined, and the distribution of surface immunoglobulin ( sIg ) -bearing cells and rosette forming cell (RFC) in the peripheral Iymphocyte were also investigated. By indirect immunofluorescence (IFA) and complement dependent antibody cytotoxicity (CDAC) assay using monoclonal antibody(Mab) against bovine leukosis tumor-associated anti-gen(BL-TAA), changes of BL-TAA positive Iymphocyte in peripheral blood were measured. The results obtained through the experiment were summarized as follows. 1. Antibody titers were measured by AGID using gP51 and P24 antigens. The animals were serologically converted at 2 months post-inoculation(pi) in gP51 antigen, whereas sero-converted at 4 months pi in P24 antigen. In comparison with antibody titers for gP51, P24 antigen showed lower titers throughout the trial period. 2. The peripheral lymphocytes from all of the infected goats, as co-cultivated with F8l cells manifested syncytial formation at 4 months pi. 3. On counting total leucocyte, Iymphocyte and atypical Iymphocyte, two out of four infected goats showed normal distribution, while No 2 of the remaining two revealed temporal and No 3, Persistant increasing number of the cells. 4. The optimal condition of rosette formation of the peripheral Iymphocyte of normal Korean native goats was shown in the sheep erythrocyte treated with 0.1M AET for 30 nun at $37^{\circ}C$. When the Iymphocytes were treated in nylon wool column, the number of sIg-bear-ing cell were increased in the nylon wool adherent cells, but RFC was increased in the non-adherent cells. Of the infected goats, No 2 and No 3 showed significantly increasing number of sIg-bearing cells at 18 months pi. 5. The Iymphocytes of No 2 and No 3 goats reacted positively in IFA using Mab against BL-TAA at 12 months pi and 18 months pi, respectively. In CDAC test, all of four infected goats revealed positive reaction at 24 months pi. The higher positive rates were observed in No 2 and No 3 as compared with the remainders.

• 대한수의학회지
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• 제45권3호
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• pp.391-398
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• 2005

Several studies have been performed on the bovine leukemia since bovine leukemia virus (BLV) had been detected in 1982 in Korea. We have conducted histopathological study on the bovine lymphoma caused by BLV because only limited results were reported on the pathological characterization of lymphoma. Lymphoma tissues were obtained from cattle necropsied and slaughtered during a designated period. Lymphoma was classified histopathologically according to the National Cancer Institute Working Formulation. Leukotic tissues consisted of fairly uniform sheets of closely packed medium to large lymphocytes without any architectural arrangement in all 30 cases. Twenty five cases belong to diffuse large cell type, while three cases were diffuse mixed cell type, and two cases were immunoblastic large cell type among 30 cases. Follicular type lymphoma was not detected in this study. The mitotic index of tumor cells showed average 2.5 in the field of 400X. Nuclear cleavage was detected in 53% of cases. Multi-nucleated cells were detected among tumor cells in 30% of lymphoma cases. In conclusion, the most common morphologic cell type of bovine lymphoma in Korea was a diffuse large cell type with multinucleated cells and nuclear cleavages.

• 대한수의학회지
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• 제45권2호
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• pp.239-244
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• 2005

Hematologic investigations were made on the blood samples taken from bovine leukemia virus (BLV)-seropositive Holstein-Friesian cattle in Korea, and their absolute lymphocyte count was compared with that of BLV-seronegative cattle. The incidence of persistent lymphocytosis (PL) was also determined. The normal bovine lymphocyte count was established on the basis of studies of 656 blood samples taken three times from 297 seronegative animals aged from 0~6 months to over 5 years at 5~6-month intervals. The data were examined according to 7 age groups of samples placed into their respective age groups. A peak in average total count was reached at 6~12 months ($5.36{\times}10^3/{\mu}l$) and thereafter the count declined continuously until over 5 years ($3.17{\times}10^3/{\mu}l$). From the results, 99.74 percent limits were calculated, and the upper limit of the range was chosen as the cutoff point for lymphocytosis. A PL was defined as a lymphocyte count that exceeded the above 99.74 percent limits and persisted over an interval of at least three months. The criterion for PL was applied to classifying 515 blood samples obtained four times from 189 seropositive animals without clinical signs at 5~7-month intervals. It was found that 54 (28.5%) of seropositive animals were with PL; cattle with PL were in age groups of 2~3 years to over 5 years.

• 한국동물위생학회지
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• 제34권4호
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• pp.303-311
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• 2011

Prevalence of infectious agents, including Brucella abortus (BA), Mycobacterium bovis (MB), bovine leukemia virus (BLV), M. avium subsp. paratuberculosis (MP), Neospora caninum (NC) and Toxoplasma gondii (TG), was investigated in all the cattle raised in Ulleung island during 2007~2010. For BA, the prevalences in head and farm were 8.1% (44/545) and 5.5% (4/73) in 2007, all negative in 2008~2009, and 0.5% (4/774) and 1.7% (1/58) in 2010, respectively. For MB, no sample was positive by PPD or ELISA in 2007~2010. For BLV and MP, no sample was positive by ELISA in 2007~2009. For NC, seroprevalences in head and farm were 0.2% (1/545) and 1.4% (1/73), respectively, in 2007 and all negative in 2008~2009. For TG, seroprevalences in head and farm were 17.6% (97/552) and 54.8% (34/62) by ELISA in 2009. By regions, the seroprevalences of TG in Ulleung-eup, Seo-myeon and Buk-myeon were 26.0%, 9.8% and 16.7%, respectively, which had significant differences (P<0.0001). Tiger cattle were more resistant to TG infection than Hanwoo. The seroprevalence of TG in summer was higher than in autumn. The seroprevalence of TG in cows was higher than in oxen. The seroprevalence of TG in cattle was increased with age. In conclusion, this study indicates that the prevalences of six infectious diseases, except for TG which are widely spread, are relatively low in cattle reared in Ulleung island.

• 한국작물학회지
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• 제63권3호
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• pp.229-238
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• 2018

글루텐닌 조성이 빵용에 적합한 최근에 육성된 3품종(백강, 중모2008 및 새금강)에 대하여 등숙기의 추가적인 질소 시비량과 시비 시기가 단백질 함량과 반죽 특성 및 단백질 분획의 변화와 빵 부피에 미치는 영향을 평가하였다. 단백질 함량은 질소 시비량과 시비 시기에 따라 증가하였으며, 침전가는 질소 시비량 증가에 따라 증가하였지만, 추비 시기는 영향이 없었다. 반죽 특성인, 가수량, 반죽 시간과 반죽 안정도는 품종에 따라 반응이 다르게 나타났으며, SE-HPLC를 이용하여 추출성 및 비추출성 총합체와 단량체 단백질 함량은 추비 처리에 따른 단백질 함량 증가에 따라 모든 품종에서 증가하였다. 빵 부피 역시 품종에 따른 반응이 다르게 나타났는데, 새금강은 질소 시비량과 시비 시기에 상관없이 증가하였으며, 백강과 중모2008은 오히려 감소하였다. 그러나, 질소 시비에 따른 단백질 함량의 변화와 빵 부피 변화는 정의 상관을 나타내었고, 침전가 및 반죽 시간과 단백질 분획 변화는 모두 빵 부피와 정의 상관을 나타내었다. 품종 별 등숙기 시비 조건에 대한 반응이 다르게 나타났기 때문에 품종 별 맞춤 시비 체계 구축과 이상기후로 인한 등숙기 환경 변화에 따른 빵용 품종에 대한 체계적인 시비 조건 확립에 대한 지속적인 연구가 필요하다.

• 한국수의병리학회:학술대회논문집
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• 한국수의병리학회 2003년도 추계학술대회초록집
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• pp.50-50
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• 2003

Enzootic bovine leukosis(EBL) is chronic disease caused by bovine leukemia virus(BLV), retroviridae. The characteristic feature of this disease is proliferation of lymphocytes in circulating blood or lymphoid tissues. Because EBL concern lymphocytes, immunological disorder or alteration in the lymphocyte subpopulation is suggested. In this study, we investigated the changes of the lymphocyte subpopulation in the circulating blood of Korean native cattle infected with bovine leukemia virus. (omitted)