Search

Your search keyword '"Beçak, W."' showing total 265 results
Start Over Author "Beçak, W."
265 results on '"Beçak, W."'

34. Bovine Papillomavirus in Brazil: Detection of Coinfection of Unusual Types by a PCR-RFLP Method

Author

Carvalho, R. F., primary, Sakata, S. T., additional, Giovanni, D. N. S., additional, Mori, E., additional, Brandão, P. E., additional, Richtzenhain, L. J., additional, Pozzi, C. R., additional, Arcaro, J. R. P., additional, Miranda, M. S., additional, Mazzuchelli-de-Souza, J., additional, Melo, T. C., additional, Comenale, G., additional, Assaf, S. L. M. R., additional, Beçak, W., additional, and Stocco, R. C., additional

Published
2013
Full Text
View/download PDF

47. Expression and In Silico Analysis of the Recombinant Bovine Papillomavirus E6 Protein as a Model for Viral Oncoproteins Studies.

Author

Mazzuchelli-de-Souza, J., Carvalho, R. F., Ruiz, R. M., Melo, T. C., Araldi, R. P., Carvalho, E., Thompson, C. E., Sircili, M. P., Beçak, W., and Stocco, R. C.

Abstract

Bovine papillomaviruses (BPVs) are recognized as the causal agents of economical relevant diseases in cattle, associated with the development of tumors in skin and mucosa. The oncogenesis process is mainly associated with different viral oncoprotein expressions, which are involved in cell transformation. The expression and characterization of recombinant viral oncoproteins represent an attractive strategy to obtain biotechnological products as antibodies and potential vaccines, Thus, the aim of this work was to clone and express the BPV-1 and BPV-2 E6 recombinant proteins and perform in silico analysis in order to develop a strategy for the systematic study of other papillomaviruses oncoproteins. The results demonstrated that BPV-1 and BPV-2 E6 recombinant proteins were expressed and purified from bacterial system as well as its in silico analysis was performed in order to explore and predict biological characteristics of these proteins. [ABSTRACT FROM AUTHOR]

Published
2013
Full Text
View/download PDF

49. Quercetin induces structural chromosomal aberrations and uncommon rearrangements in bovine cells transformed by the E7 protein of bovine papillomavirus type 4.

Author

Leal, A. M., Ferraz, O. P., Carvalho, C., Freitas, A. C., Beniston, R. G., Beçak, W., Campo, M. S., and Stocco dos Santos, R. C.

Subjects
QUERCETIN, CHROMOSOME abnormalities, CELLS, CATTLE
Abstract

Abstract Bovine papillomavirus type 4 (BPV-4) and bracken fern are cofactors in the carcinogenesis of the upper gastrointestinal (GI) tract of cattle. An experimental in vitro model system has been developed to analyse the co-operation between the viral transforming protein E7, the cellular ras oncogene and quercetin, one of the mutagens of bracken fern, during neoplastic progression of primary bovine cells. We now report cytogenetic studies of these cells at different stages of malignant transformation: parental primary non-transformed PalF cells; E7R cells transformed by BPV-4 E7 and activated ras but not tumorigenic, and tumorigenic E7Q cells derived from E7R cells after treatment with quercetin. All cell lines presented increased numbers of aneuploid cells. The rate of structural chromosomal aberrations observed was increased in transformed cells. In addition, E7Q cells showed chromosomes with peculiar rearrangements, which resulted in metacentric and submetacentric marker chromosomes, with an increase in the mean chromosome arm number. These markers were the products of possible centric fusions. These aberrations and rearrangements were distributed throughout the karyotype, no specific chromosome was involved and the heterochromatic centromeric regions appeared to be preserved. [ABSTRACT FROM AUTHOR]

Published
2003
Full Text
View/download PDF

50. Clastogenic effect of bracken fern (Pteridium aquilinum v. arachnoideum) diet in peripheral lymphocytes of human consumers: preliminary data.

Author

Recouso, R. C., Santos, R. C. Stocco dos, Freitas, R., Santos, R. C., Freitas, A. C. de, Brunner, O., Beçak, W., and Lindsey, C. J.

Subjects
PTERIDIUM aquilinum, LYMPHOCYTES, CANCER
Abstract

Abstract Ingestion of bracken fern (Pteridium aquilinum v. arachnoideum) is associated with digestive tract cancer in different regions of Japan, Venezuela and Brazil. In view of reports that dietary bracken fern causes chromosomal instability in cattle, the clastogenic effect of bracken fern was investigated, in a preliminary study, in peripheral lymphocytes obtained from habitual consumers and a control group of non-consumers, which were carefully investigated about cancer history or family cancer history, negative in both cases, using protocols comparable to those previously described in studies in cattle raised on bracken pastures. Cytogenetic analysis showed significant increased levels of chromosomal abnormalities, such as chromatid breaks, in cultured peripheral lymphocytes of the consumer group. There was no correlation with subjects, gender, smoking habits or alcohol consumption, and the only correlation was with prolonged exposure to dietary bracken. [ABSTRACT FROM AUTHOR]

Published
2003
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results