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Purification of chalone from the spleen of cattle

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By the SDS treatment of subcellular fractions from the bovine spleen, the subfractions showing antimitotic activity in relation to the spleen were separated from those showing activity against lymph nodes and the thymus of mice. The farmer is contained in sediments II from rough microsomes (B1S) supernatants, and the latter mainly in the sediment and supernatant II from the smooth microsomes (A1S) supernatants and in supernatant II from B1S. The protein analysis seems to indicate, that chalone active in relation to the spleen is a protein, showing gamma globulins mobility. The chalone active in relation to the lymph nodes seems to be a protein with mobility of α-globulins and of prealbuminus. Separations on Sephadex seems to give satisfactory purification of chalone.
A control scheme for antigenic preparations of bovine C-type leukosis virus (BLV) was developed. It contains a description of serological tests showing the appearance and immunological activity of specific antigens. Also presented were methods of detecting unspecific antigens of viral, bacterial, fungal etc. origins. In addition, the ways of contamination of these preparations were discussed.
Eight commercial BLV antigens for serological diagnosis of the disease were compared. They were produced in the U.S.A., Federal Republic of Germany, Bulgaria, Romania, Czechoslovakia, Poland, German Democratic Republic and the Soviet Union. Homogenity of these preparations was investigated by means of polyacrylamide gel electrophoresis. The contaminations with bovine serum proteins were estimated by immunoelectrophoresis. The serologic activity of them was established with SRID, using the same sera (BLV positive and negative). It has been demonstrated that all the preparations proved to be suitable for the practical use and they yielded comparable results.
Цель рабозы состояла в оценке пригодности серологического исследования домолозивного секрета засушенных короо в св стадах, инфицированных вирусом еЬЬ. У 103 засушенных коров параллельное исследование сыворотки крови и домолозивного секрета критерием ГО, показало положительную реакцию у 73 голов, тогда как исследование самой сыворотки дало положительный результат,. только у 29 голов. Из проведенных наблюдений вытекает необходимость применения домолозвиного секрета в разпознавании еЬЪ.
Исследовали уровень антител в сыворотке крови 17 положительных серологически коров в период 8 недель перед родами, 2 часа после родов, а тоже через 7 очередных дней. Секрет молочной железы брали от этих коров 2 часа после родов и ежедневно 7 дней. Уровень антител в сыворотке крови и молозиве исследовали тестом ID. Констатировали корреляцию между уровнем титра антител в сыворотке крови и молозиве, а тоже периодом их сохранения в молозиве. Средний титр в молозиве является 8-кратно выше титра в сыворотке крови беременных коров, определенного на 2 месяца перед родами.
Представили тест, основанный на обозначении активности ревертазной транскриптазы, который позваляет косвенно доказать присутствие вируса ЕВВ в тканевой культуре, а тоже наблюдать динамику освобождения вируса в культурную жидкость. При помощи этого теста исследовали влияние качества сыворотки, добавочно применяемой в питательной среде, на эффективность культуры. Констатировали, что добавление сыворотки О-а-С позволяет около двухкратно увеличать эффективность культуры по сравнении с традиционной культурой, основанной на сыворотке телят. Констатировали, что вышеуказанный тест в отношении повторяемости (коэффицент изменяемости (W) = 29%) отзечает другим тестам, особенно похожему, основанному на краткосрочной культуре, разработанному Росслером и сотр (13).
В описанном тесте применяли реагенты, изготовленные в Отделе биохимии Ветеринарного Института в Пулавах. Антиген вируса из клеточной линии FLK-BLV и очищали техникой ультрацентрифугирования. Кроличьи иммуноглобулины против IgG крупного рогатого скота конъюгировали со щелочной фосфатазой при помощи глютарового альдегида. Вступительные определения антител в сыворотках крупного рогатого скота и овец, а тоже в молоке коров, свидетельствуют о большой чувствительности и удовлетворительной специфичности стета. По сравнению с тестом иммунодиффузии тест ELISA является около 100 раз более чувствительным, а в лейкозном стаде констатировали большее число положительно реагирующищх животных. При использовании теста ELISA показалось возможным определение антител в молоке коров, хотя большинство проб реагировало отрицательно в иммунодиффузии.
Immunosuppressive proteins were isolated from the sera of cattle suffering from leukosis by employing column chromatography fractionation on DEAE- cellulose, Sephadex G-200 and Sephadex QAE-50A, The resulting three proteins which were homogenous as judged by polyacrylamide gel electrophoresis were found to suppress in vivo the induction of splenic plaque forming cells in mice. The specific activity of the pure proteins were increased to 67-75% in comparison to 31% of the raw material. The pure proteins contain from 15 to 45 µg/mg of hexoses and their molecular weights were approximately the same and were estimated on 70000 by means of SDS polyacrylamide gel electrophoresis.
Polish ELISA set, prepared in the Veterinary Research Institute, has been compared with sets produced in the German Federal Republic, Czechoslovakia, France and Belgium. Comparative examinations were performed in a herd comprising 44 cows which revealed a high percentage of positive reagents in the AGID test. In general, the results obtained by means of different tests, recommending high dilution of sera, showed several negative results in samples which appeared to be positive by using other sets. The investigations showed that the Polish ELISA set for the diagnosis of bovine leukosis is not inferior to the commercial sets, offered by the renowned biological producers.
Pure IgG₁ and IgG₂ globulins were obtained by means of precipitation with ammonium sulphate and subsequent fractionation in DEAE Sephadex A-50 column. The IgM globulin was isolated by means of chromatography on Sephadex G-200 and DEAE-cellulose. Antibodies to these proteins were produced by immunization of rabbits and goats. Purity of proteins and monovalence of antibodies were checked up by means of immunoelectrophoresis and polyacrylamide gel electrophoresis.
The protein antigens of BLV were detected in the lysates of bovine lymphocytes stimulated in vitro using the Western blot method. Specific antibodies against BLV were detected in the sera of animals by the ELISA test. Protein bands of the molecular weight 72, 51, 35 and 24 kD were detected by the rabbit antiserum against BLV in the blots from infected lymphocytes and FLK cells. Thе proteins mentioned above were not detected in the lysates of lymphocytes of uninfected animals. Densitometry analysis of immunoblots from FLK cells indicated that a minimal amount of 100 ug of gp51 viral protein can be discovered. The presence of BLV antigens and specific antibodies were detected in 18 of 25 animals. The antibodies were also found in four cows of the remaining seven animals whose lymphocytes were free from BLV proteins.
In two experiments 22 sheep have been immunized with BLV attenuated by UV. The vaccinated animals were' challenged with an active BLV. A dose of vaccine was higher in the first experiment. A seroconversion has appeared in all the vaccinated animals within 3—4 weeks. A challenge caused a considerable increase of the titre of specific antibodies. Both in challenged and in unchallenged sheep the antibodies persisted till the end of the experiment, i.e. for more than 1200 days. In the vaccinated but not challenged animals BLV was not found in blood. It has been stated that vaccination protected animals from an active BLV only when a dose of the virus was low. Large doses of the virus destroy immunological resistance inducing a nodular form of enzootic bovine leukosis.
Appearance of IgG₁, IgG₂, IgM in blood serum was investigated in 12 calves, experimentally inoculated with BLV, immediately after birth. The titer of BLV antibodies, was also examined by means of ID and ELISA tests. An increase of IgG₂ fractions has been found in the first week after infection. However, this protein seems not to be a specific antibody. Properties of antibody have been revealed by the IgG₁ and IgM fractions. The results seem to indicate that IgG₁ fraction takes part in the precipitation observed in the ID test, whereas the IgM globulins are active in the ELISA test.
FLK cells persistently infected with BLV were used for the preparation of two vaccines. One contained the formalin-fixed cells (FORM vaccine) and another the cells treated with glutaraldehyde (GLUT vaccine). The concentration, temperature and time of action of the fixatives were different. It was stated that the vaccine FORM elucited the formation of antibodies for the gp antigen of BLV which persisted in the serum not longer than 75 days. The prolongation of this time could be achieved by means of revaccination of animals or by injection of an appropriate dose of BLV. The resistance acquired due to the vaccination could be overcome by a large dose of BLV. Since, the vaccine had only a limited capacity to control the horizontal transmission of the virus, therefore, it could not be recommended for practical use. The vaccine GLUT proved to be ineffective. The effectiveness of the both preparations was compared with that one prepared previously from BLV treated with UV rays.
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