Petra Blankenstein

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Infection of cattle with the bovine leukemia virus (BLV) results in a strong permanent antibody response to the BLV antigens some weeks after infection. However, cattle may carry provirus and not have detectable antibody titers. To prove the occurrence of different BLV provirus variants in German cattle and to study the influence of special BLV variants on(More)
237 cattle of a dairy herd in Syria were tested for anti-BLV antibody by the ELISA. 194 animals were additionally examined by the agar gel immunodiffusions test (AGID) on BLV antibodies and 100 by polymerase chain reaction (PCR) for BLV provirus. BLV specific antibodies were determined by means of AGID and ELISA at 62.9% and 69.2% of the examined animals,(More)
Due to the prevalence of different bovine leukosis virus (BLV) species in the cattle population in Europe, problems may arise in the serological diagnosis of BLV infections. In addition, earlier investigations demonstrated that contamination of the BLV antigen-producing cell culture systems by bovine viral diarrhea virus (BVDV) may give rise to(More)
A first attempt for the investigation of molecular epidemiology of BLV was carried out. PCR amplicons of a part of the env gene of BLV isolated from 309 cattle of different geographical origin were compared with known BLV env sequences. Using RFLPA most of the PCR products can be assigned to the Australian, the Japanese or the Belgian subgroup. A(More)
The practical application of polymerase chain reaction (PCR) for the diagnosis of bovine leukaemia virus (BLV) infections in naturally infected cattle was evaluated. Compared to serological tests the PCR was definitely found to be a more sensitive method, yielding the highest number of positive results (10% more compared to enzyme-linked immunosorbent(More)
Enzootic bovine leukosis is caused by the bovine leukemia virus (BLV) and has a world wide distribution in cattle. Due to the program for eradication of BLV-infections in Germany the BLV incidence in cattle declined and only few new cases seem to occur per year. On the other hand, BLV-infected cattle with low, transient or without BLV-antibody titers are(More)
The selection of animals infected with the bovine leukaemia virus (BLV) is performed by the immunological detection of antibodies against the virus, commonly using the antigen gp51. Furthermore, research is being carried out to develop protective vaccines against BLV that have gp51 as their main component. Taking both of these factors into account, it is(More)
Prolyl hydroxylase, which is responsible for the hydroxylation of peptidyl proline residues, has been isolated and purified from the green alga Chlamydomonas reinhardii. The enzyme, which appears to be loosely associated with microsomal membranes, was released into solution by sonication in the presence of detergent. Purification was achieved by(More)
Comparative studies were conducted through more than six months into quantitative of bovine leukaemia virus (BLV) antigen of FLC/BLV 44 and its FLC/BLV 44-4 subline by means of an enzyme immuno-assay (EIA), using monoclonal antibodies against gp51 and p24. Synthesis of gp51 (factors of two to six) and of p24 (factor of two) by FLC/BLV 44 was clearly higher(More)
The calcium ionophore A23187, which was used to increase the intracellular calcium concentration ([Ca2+]i), was analyzed for effects on bovine leukemia virus (BLV) expression in two BLV infected cell lines. To clarify the role of intracellular free calcium in this response, [Ca2+]i was measured during ionophore treatment with the fluorescent calcium(More)