Perfil fenotípico de linfócitos periféricos de bovinos de raças européias Phenotypic profile of peripheral blood lymphocytes from European bovines

<abstract language="eng">The phenotypic profile of bovine lymphocytes was evaluated in 18 bovines (Bos taurus) from three different breeds, being nine Holstein, six Hereford, and three Brown Swiss. All animals were free from ticks and hemoparasites, as determined after jugular vein blood sampling. The immunophenotypes of peripheral lymphocytes were evaluated by flow cytometry. Peripheral lymphocytes were exposed to bovine fluorescein-labeled monoclonal antibodies including anti-CD4, anti-CD8, and anti-purified bovine CD21 specificities. After lysing the erythrocytes with a commercial lysing solution (FACS TM ), the lymphocytes were washed, fixed, and evaluated by flow cytometry. Significant differences in the phenotypic profiles of peripheral lymphocytes among all breeds were found. Holstein animals showed a lower percentage of total T lymphocytes (CD4 and CD8) and higher percentage of B lymphocytes (CD21). In addition, the lymphocytes from Holstein animals showed a lower T/B ratio than the lymphocytes from Hereford animals. These results suggest the existence of different phenotypic profiles of peripheral lymphocytes from European breeds of cattle. Such differences may be related to the different pattern of immune response described for these breeds in the literature and may account to varying disease resistance among breeds

Two new species of the side necked turtle genus, Bairdemys (Pleurodira, Podocnemididae), from the Miocene of Venezuela

The side-necked turtle genusBairdemys (Podocnemididae,Shweboemys Group) from the Miocene of Venezuela and Puerto Rico is revised, and four species are diagnosed on the basis of skull characters; two are de-scribed as new.B. hartsteini Gaffney & Wood, 2002, from the Cibao Formation of Puerto Rico, is characterized by a higher skull, with a straight labial ridge and a premaxillary notch;B. venezuelensis (Wood & Díaz de Gamero 1971), from the Urumaco Formation of Venezuela, is characterized by the absence of a premaxillary notch, a high anterior triturating surface convexity, a deep posterior triturating surface concavity, and a short pterygoid mid-line contact;B. sanchezi, new species, from the Urumaco Formation of Venezuela, is characterized by a very low anterior triturating surface convexity and shallow posterior triturating surface concavity, a premaxillary notch, small size, and extensive temporal and cheek emargination;B. winklerae, new species, from the Urumaco Formation of Venezuela, is characterized by an elongate, narrow snout, with a concave labial ridge, and no premaxillary notch. Based on osteological and bone histological results, an additional strongly crushed skull and associated cara-pace fragment of a previously undetermined podocnemidid from the Urumaco Formation of Venezuela can be further referred toPodocnemis or a closely related taxon — again underscoring the importance of this formation as one of the major fossil lagerstätten of turtles in South America