Rav
Mostrando 37-48 de 100 artigos, teses e dissertações.
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37. Susceptibility to erbB-induced erythroblastosis is a dominant trait of 151 chickens.
Rous-associated virus-1 (RAV-1)-induced erythroblastosis results from proviral insertions into or viral transductions of the c-erbB region of the epidermal growth factor gene. Most chickens develop low incidences (less than 5%) of RAV-1-induced erythroblastosis. However, an inbred line of chickens (151) suffers high incidences (approximately 80%) of RAV-1-in
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38. Rapid induction of hypothyroidism by an avian leukosis virus.
Infection of 10-day chicken embryos with an avian leukosis virus, RAV-7, resulted in hypothyroidism within 3 weeks posthatching. Histological examination of the thyroids from infected chickens showed an extensive infiltration of lymphoblastoid cells by 7 days posthatching. Areas resembling germinal centers were present in the thyroids of infected chickens by
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39. Activation and transduction of c-mil sequences in chicken neuroretina cells induced to proliferate by infection with avian lymphomatosis virus.
We report that nondividing neuroretina cells from chicken embryos can be induced to proliferate following infection with Rous-associated virus type 1 (RAV-1), an avian lymphomatosis retrovirus lacking transforming genes. Multiplication of RAV-1-infected neuroretina cells is observed after a long latency period and takes place initially in a small number of c
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40. Microinjection analysis of envelope-glycoprotein messenger activities of avian leukosis viral RNAs.
Virion RNA from the avian leukosis virus Rous-associated virus 2 (RAV-2) and poly(A)-containing RNAs from RAV-2-infected chick embryo fibroblasts were microinjected into fibroblasts transformed by the Bryan high-titer strain of Rous sarcoma virus (RSV), which is deficient in viral envelope glycoprotein. Production of infectious RSV following these injections
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41. Induction of neoplasms by subgroup E recombinants of exogenous and endogenous avian retroviruses (Rous-associated virus type 60).
Chickens susceptible to infection with subgroup E viruses were inoculated with four independent isolates of Rous-associated virus type 60 (RAV-60) that are subgroup e recombinants of endogenous and exogenous virus. Neoplasms developed in each inoculated group. Therefore, nontransforming viruses of subgroup E can induce lymphoid leukosis at a moderate rate co
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42. Recombination between the defective component of an acute leukemia virus and Rous associated virus O, an endogenous virus of chickens.
The ability of the defective acute leukemia virus of chickens, MC-29, to participate in recombination was investigated by testing the ability of the MC-29 genome to donate sequences to its helper virus. The endogenous virus Rous associated virus O (RAV-O) was used as a helper for MC-29, and its genome was compared by fingerprinting to that of the original RA
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43. Immunocompetence of chickens during early and tumorigenic stages of Rous-associated virus-1 infection.
A study was designed to determine the effects of congenital infection with the Rous-associated virus-1 (RAV-1) on the immune function chickens during the early and late tumorigenic stages of infection. In another experiment, the effects of niridazole on the immune competence and the tumor incidence in chickens congenitally infected with RAV-1 were studied. L
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44. Comparative study of three methods for detecting avian leukosis viruses.
This investigation was designed to compare detection limits for avian leukosis viruses after infection of chicken fibroblasts with decimal dilutions of Rous-associated virus type 1 (RAV-1). At 5, 9, 14, and 19 days postinfection, cells were examined for group-specific (gs) antigens by microtiter complement-fixation (CF) tests for avian leukosis viruses and b
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45. Common mechanism of retrovirus activation and transduction of c-mil and c-Rmil in chicken neuroretina cells infected with Rous-associated virus type 1.
We previously described the isolation of the IC10 retrovirus which transduced the v-Rmil oncogene, a new member of the mil/raf gene family. This virus was generated during serial passaging of Rous-associated virus type 1 (RAV-1) in chicken embryo neuroretina (NR) cells and was selected for its ability to induce proliferation of these nondividing cells. IC10
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46. Endogenous avian retroviruses contain deficient promoter and leader sequences.
A sensitive and quantitative biological assay has been utilized to measure the ability of the exogenous and endogenous avian retroviral long terminal repeats (LTR) to promote gene expression in avian cells. This assay has revealed that the exogenous virus RAV-2 LTR is approximately equal to 10-fold more active than the LTRs of endogenous viruses RAV-0, ev-1,
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47. Development of avian sarcoma and leukosis virus-based vector-packaging cell lines.
We have constructed an avian leukosis virus derivative with a 5' deletion extending from within the tRNA primer binding site to a SacI site in the leader region. Our aim was to remove cis-acting replicative and/or encapsidation sequences and to use this derivative, RAV-1 psi-, to develop vector-packaging cell lines. We show that RAV-1 psi- can be stably expr
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48. Integration of Rous-associated virus type O provirus in susceptible chicken cells.
The number of viral genome equivalents per haploid cell genome was determined in normal chicken embryos from three selected chicken lines and in cultured fibroblasts (CEF) from these embryos. The cellular concentration of endogenous proviral DNA is similar in embryos from chickens of lines SPAFAS, 7, 15, 7 x 15, and 100. The concentration of proviral DNA is