Genetic variation and population structure of two species of neo-tropical mud-mussels (Mytella spp)

Mytella guyanensis Lamarck (1819) and Mytella charruana d'Orbigny (1846) are widespread euryhaline bivalves that have become commercially important in Brazil. Despite their importance, however, no genetic information that would be useful to orient governmental policies is available for these species. We analyzed, through allozyme electrophoresis, populations of M. guyanensis and M. charruana along 3,500 km of Brazilian coast. Pairwise comparisons among gene frequencies in M. guyanensis resulted in high levels of pairwise gene identity (I = 0.976 to 0.998). Conversely, significant levels of population structure were found in both M. guyanensis (FST = 0.089) and M. charruana (FST = 0.102). Heterozygosity levels for both species were high (H(e) = 0.090 to 0.134 in M. guyanensis and H(e) = 0.191 to 0.228 in M. charruana). The larger population size of M. charruana could explain, at least partially, the higher levels of genetic variability for this species. These levels of genetic variability yield an effective population size estimate of about 300,000 for M. guyanensis, and 540,000 for M. charruana, based on neutralist expectations. Remarkably, these numbers are much smaller than the estimated actual population sizes. This distortion might be explained by unstable population sizes and it suggests that long-term genetic variability studies are crucial to prevent artifactual viability analysis data for these commercially exploited species.

Molecular phylogeny of penaeid shrimps inferred from two mitochondrial markers

Penaeid shrimps are an important resource in crustacean fisheries, representing more than the half of the gross production of shrimp worldwide. In the present study, we used a sample of wide-ranging diversity (41 shrimp species) and two mitochondrial markers (758 bp) to clarify the evolutionary relationships among Penaeidae genera. Three different methodologies of tree reconstruction were employed in the study: maximum likelihood, neighbor joining and Bayesian analysis. Our results suggest that the old Penaeus genus is monophyletic and that the inclusion of the Solenocera genus within the Penaeidae family remains uncertain. With respect to Metapenaeopsis monophyly, species of this genus appeared clustered, but with a nonsignificant bootstrap value. These results elucidate some features of the unclear evolution of Penaeidae and may contribute to the taxonomic characterization of this family.

Aprofundamento do sulvo troclear e implante de grampo metálico para correção da luxação de patela na espécie canina - estudo clínico

O artigo não apresenta resumo.

Regulation of T cell response to leishmania antigens by determinants of histocompatibility leukocyte class I and II molecules

It has been shown that HLA class I molecules play a significant role in the regulation of the proliferation of T cells activated by mitogens and antigens. We evaluated the ability of mAb to a framework determinant of HLA class I molecules to regulate T cell proliferation and interferon gamma (IFN-g) production against leishmania, PPD, C. albicans and tetanus toxoid antigens in patients with tegumentary leishmaniasis and healthy subjects. The anti-major histocompatibility complex (MHC) mAb (W6/32) suppressed lymphocyte proliferation by 90 percent in cultures stimulated with aCD3, but the suppression was variable in cultures stimulated with leishmania antigen. This suppression ranged from 30-67 percent and was observed only in 5 of 11 patients. IFN-g production against leishmania antigen was also suppressed by anti-HLA class I mAb. In 3 patients IFN-g levels were suppressed by more than 60 percent, while in the other 2 cultures IFN-g levels were 36 and 10 percent lower than controls. The suppression by HLA class I mAb to the proliferative response in leishmaniasis patients and in healthy controls varied with the antigens and the patients or donors tested. To determine whether the suppression is directed at antigen presenting cells (APCs) or at the responding T cells, experiments with antigen-primed non-adherent cells, separately incubated with W6/32, were performed. Suppression of proliferation was only observed when the W6/32 mAb was added in the presence of T cells. These data provide evidence that a mAb directed at HLA class I framework determinants can suppress proliferation and cytokine secretion in response to several antigens

Estrechez pielo ureteral: nuestra experiencia con la técnica de Anderson-Hynes / Pyelouretheral obstruction: experience with Anderson-Hynes technic

Presentamos nuestra experiencia con la pieloplastía de Anderson Hynes, en la reparación de la estrechez pielo-uretral. Se incluyeron en la investigación 55 pacientes, oteniendo éxito en 50 de ellos y escasas complicaciones. Destacamos las bondades de la técnica en adultos, y hacemos énfasis en la evaluación de la operación usando la renografía isotópica con Tc 99. Se discute la utilidad de dejar siempre tutor ureteral y nefrostomía