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Braz. J. Vet. Pathol. ; 4(3): 184-189, 2011.
Artigo em Inglês | VETINDEX | ID: vti-685199


The degree of genetic and pathologic variation exhibited by a turkey Coronavirus (TCoV) strain was investigated after nine serial passages in 25-day-old turkey embryos obtained from wild broad-breasted bronze breeders. In spite of spleen, liver, kidneys, cloacal bursa and thymus have been collected and analysed, the main histopathological changes were only documented in the intestine sections. Microscopic lesions were characterized as mild enteritis, low degree of enterocyte vacuolization and detachment of the intestinal villous after five consecutive passages and were considered absent in the last passages. Genealogic analysis based on S1 and S2 DNA sequences suggested that Brazilian isolate might be considered as originated from TCoV strains circulating in the United States, as 100% identity with TCoV-Gl strain. Although S1 S2 sequences from each passage revealed no significant point mutations, and no correlation could be speculate between S2 nucleotide changes and pathologic features in infected embryos. This is the first demonstration of wild turkey embryos as a model for TCoV isolation and propagation.

Braz. J. Vet. Pathol. ; 4(1): 67-75, 2011.
Artigo em Inglês | VETINDEX | ID: vti-684951


Canine transmissible venereal tumor (CTVT) is a neoplasm transmitted by the physical transfer of viable tumor cells by direct contact with injured skin and/or mucous tissue. These cells can transpose across histocompatibility barriers into unrelated hosts. This review focuses on the biology of apoptosis and the interaction of proteins involved in this process, as well as p53, p63 and the antiapoptotic protein Bcl-2. As such, this disease offer unique opportunity to study the biology of transplantable tumours and the interaction of proteins involved in apoptosis process and the prognosis of CTVT.

Braz. J. Vet. Pathol. ; 4(1): 30-35, 2011.
Artigo em Inglês | VETINDEX | ID: vti-684932


Infection of young poults with turkey coronavirus (TCoV) produces a syndrome characterized by acute enteritis, diarrhea, anorexia, ruffled feathers, decreased body weight gain and uneven flock growth. The objective of this study was to standardize an intestinal organ culture (IOC) in order to assess host-virus interaction related to apoptosis. For this purpose the Brazilian strain (TCoV/Brazil/2006 with GenBank accession number FJ188401), was used for infection. Infected IOC cells had mitochondrial dysfunction and initial nuclear activation with MTT value of 90.7 (± 2.4) and apoptotic factor 2.21 (± 2.1), considered statistically different from uninfected IOC cells (p > 0.05). The kinetics of TCoV antigens and viral RNA was directly correlated to annexin-V, caspases- 2 and -3, p53, BCl-2 antigens at 24, 72 and 96 h post-infection (p.i.). Morphological and biochemical features of apoptosis, such as in situ nuclear fragmentation (TUNEL and annexin-V) and DNA ladder formation were also detected in infected cells at all assayed p.i. intervals. Moreover, different from other coronaviruses, the expression of both effective caspase-2 and - 3 and p53 antigens were considered lower. However, at all p.i., the BCl-2 antigens were expressed quantitatively and qualitatively as viral antigen measured by immunofluorescence microscopy analysis. Because the diagnosis of TCoV infection is onl

Braz. J. Vet. Pathol. ; 2(2): 75-79, 2009.
Artigo em Inglês | VETINDEX | ID: vti-683702


We exposed chicken embryos at embryonating day (ED18) to a cell-adapted very virulent strain of IBDV (ca-vvIBDV) and original vvIBDV and examined the apoptosis from infected bursa of Fabricius (BF) and thymus organs. Following ca-vvIBDV exposure, embryonic bursa showed mild cellular destruction, lower rate of apoptosis and presence of viral proteins detectable by immunohistochemistry. In contrary, original vvIBDV exposed embryos had an enhanced detectable changes in the bursa associated to an increase apoptotic events, and most of the times, total destruction of BF follicles. In thymus, viral antigen was detectable until after hatch. Positives cell signals to activated caspase-3 were intensively detect in embryos lymphoid tissues exposed to original vvIBDV observed in BF and less in thymus. No immunoreactive thymocytes were visualized in embryos exposed to ca-vvIBDV. Apoptosis changes, such as chromatin condensation, DNA fragmentation, and the appearance of apoptotic nuclear bodies, were observed in both organs. TUNEL-detected DNA was more intense in original vvIBDV infected lymphoid cells, and less apoptotic cells were detectable in attenuated strain. By sequencing analysis, the attenuation presented amino acid changes at position 222 (AP), 256 (IV) and 279 (DN). One serine in the serine-rich heptapeptide (position 333) was substituted into other amino acid which is similar