Enzootic haematuria and urinary bladder cancer in cattle are associated with feeding on bracken fern and bovine papillomavirus (BPV) infection. An increased rate of chromosomal aberrations in peripheral blood lymphocytes from chronically affected haematuric cows raised in bracken fern pastures has been reported, suggesting the presence of BPV in the peripheral blood of afflicted animals. The purpose of the present investigation was to examine the role of peripheral blood as a potential BPVtransmitting agent and search for clastogenic effects in experimentally infected animals kept on a bracken fern-free diet. Healthy cows were inoculated with blood samples of haematuric animals every two weeks for 18 months. Recipient cows, their offspring, donor animals and a control group were kept on a bracken fern-free diet throughout the experiment. Clinical and molecular analyses for

The production of a healthy cloned calf is dependent on a multitude of successful steps, including reprogramming mediated by the oocyte, the development of a functional placenta, adequate maternal-fetal interaction, the establishment of a physiological metabolic setting and the formation of a complete set of well-differentiated cells that will eventually result in well-characterised and fully competent tissues and organs. Although the efficiency of nuclear transfer has improved significantly since the first report of a somatic cell nuclear transfer-derived animal, there are many descriptions of anomalies concerning cloned calves leading to high perinatal morbidity and mortality. The present article discusses some our experience regarding perinatal and neonatal procedures for cloned Zebu cattle (B. indicus) that has led to improved survival rates in Nellore cloned calves following the application of such 'labour-intensive technology'.

RESUMODeterminou-se a concentração de proteína total e de suas frações (albumina, alfa globulina, beta

ABStRACt. Bovine papillomavirus (BPV) DNA sequences were detected in different tissues, in addition to epithelium. Cytogenetic abnormalities were observed in blood lymphocytes. The presence of more than one virus in a single tissue is a difficult aspect to evaluate, especially when the DNA sequences are detected in tissues that are not specifically targeted by the virus. BPV and bovine leukemia virus (BLV) are clastogenic, causing chromosome aberrations in peripheral blood lymphocytes. In the present study, we investigated the simultaneous presence of DNA sequences of both viruses and the possibility of vertical transmission and compared the types of chromosome aberrations related to viral action. BPV 1, 2, and 4 DNA sequences were found in three females of the herd and in their offspring. BLV DNA sequences were not detected in their progeny. A newborn calf that was negative for BLV infection showed specific chromosome rearrangements possibly related to the effect of infection with BPV.

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120 dias de prenhez); e recém-paridas (< 30 dias de puerpério). Nas amostras de sangue, colhidas em frascos contendo EDTA, foi realizada a contagem do número total de leucócitos em câmara de Neubauer, utilizando-se o líquido de Thoma como diluidor e a contagem diferencial de leucócitos,efetuada em esfregaços sangüíneos, corados pelo Método de Rosenfeld. Observou-se a influência da gestação sobre o leucograma, pois o quadro leucocitário foi caracterizado por uma diminuição gradual do número de leucócitos com o avançar da gestação, atingindo seus menores valores no final da gestação e no puerpério. Essa diminuição ocorreu devido ao comportamento observado para o número absoluto de linfócitos, que também diminuiu com a evolução da gestação. Dessa forma, o quadro leucocitário tornou-se, predominantemente, neutrofílico na fase final da gestação e no puerpério.]]>