Estudo comparativo entre as técnicas de nissen e Boix-Ochoa em ratos / Comparative study between the techniques of the nissen and Boix-Ochoa in rats

OBJETIVO: Comparar, em ratos, a eficiência das técnicas de Nissen e Boix-Ochoa no tratamento do refluxo gastroesofagiano (RGE) induzido pela operação de Heller. MÉTODO: Foram usados 30 ratos Wistar, com idades entre 40 e 60 dias de vida e peso corporal entre 210 g e 342 g. Os animais foram distribuídos em três Grupos (A, B, C) de 10 ratos. Em todos os animais realizou-se a operação de Heller. No Grupo B ela foi seguida de uma operação de Nissen e, no Grupo C, de uma operação de Boix-Ochoa. A pressão intra-gástrica necessária para produzir RGE foi medida em todos os animais: antes de qualquer procedimento; imediatamente após as operações de Heller, Nissen e Boix-Ochoa; e seis semanas depois, quando os animais foram mortos. RESULTADOS: Verificou-se que tanto a recuperação da perda de peso, que caracteriza o quadro de RGE, como a reconstituição mais fisiológica dos gradientes pressóricos gastroesofagianos são obtidos de forma mais eficiente pela técnica de Boix- Ochoa. CONCLUSÃO: As operações de Nissen e Boix- Ochoa são eficientes no tratamento do RGE induzido pela técnica de Heller, em ratos. A segunda, no entanto, restaurou, de forma mais adequada, os valores fisiológicos dos parâmetros estudados neste trabalho: o peso corporal e os gradientes pressóricos gastroesofagianos.

OBJECTIVE: To compare, in rats, the efficiency of Nissen and Boix-Ochoa techniques in the treatment of gastroesophageal reflux (GER) induced by a Heller's procedure. METHOD: 30 rats Wistar aged between 40 and 60 days and weighing between 210 g and 342 g were used. The animals were divided in three (A,B,C) groups of 10 rats each. A Heller's operation was made in all the animals. In group B, it was followed by a Nissen procedure and, in group C, by a Boix-Ochoa procedure. The intragastric pressure necessary to produce reflux was mesured in all animals: before any procedure; immediately after the Heller, Nissen and Boix-Ochoa porcedures; and 6 weeks later, when the animals were killed. RESULTS: Restauration of body weight and reconstitution of more physiologic gastroesophageal pressure gradients were more effective with the Boix-Ochoa technique. CONCLUSION: the techniques of Nissen and Boix-Ochoa are effective in the treatment of GER induced by a Heller's procedure in rats. The second one, howerver, restaures, more adequately, the physiologic values of the two parameters used in this study: body weight and gastroesophageal pressure gradients.

Intraspecific and interspecific genetic and phylogenetic relationships in the genus Populus based on AFLP markers.

Although Populus has become the model genus for molecular genetics and genomics research on forest trees, genetic and phylogenetic relationships within this genus have not yet been comprehensively studied at the molecular level. By using 151 AFLP (AFLP is a registered trademark of Keygene) markers, 178 accessions belonging to 25 poplar species and three interspecific hybrids were analyzed, using three accessions belonging to two willow species as outgroups. The genetic and phylogenetic relationships were generally consistent with the known taxonomy, although notable exceptions were observed. A dendrogram as well as a single most parsimonious tree, ordered the Populus sections from the oldest Leuce to the latest Aigeiros, a pattern consistent with their known evolutionary relationships. A close relationship between Populus deltoides of the Aigeiros section and species of the Tacamahaca section was observed and, with the exception of Populus wilsonii, between the species of the Leucoides, Tacamahaca, and Aigeiros sections. Populus nigra was clearly separated from its consectional P. deltoides, and should be classified separately from P. deltoides. The AFLP profiles pointed out to the lack of divergence between some species and revealed that some accessions corresponded with interspecific hybrids. This molecular study provides useful information about genetic relationships among several Populus species and, together with morphological descriptions and crossability, it may help review and update systematic classification within the Populus genus.

Ex-situ conservation of Black poplar in Europe: genetic diversity in nine gene bank collections and their value for nature development.

Populus nigra L. is a pioneer tree species of riparian ecosystems that is threatened with extinction because of the loss of its natural habitat. To evaluate the existing genetic diversity of P. nigra within ex-situ collections, we analyzed 675 P. nigra L. accessions from nine European gene banks with three amplified fragment length polymorphism (AFLP) and five microsatellite [or simple sequence repeat (SSR)] primer combinations, and 11 isozyme systems. With isozyme analysis, hybrids could be detected, and only 3% were found in the gene bank collection. AFLP and SSR analyses revealed effectively that 26% of the accessions were duplicated and that the level of clonal duplication varied from 0% in the French gene bank collection up to 78% in the Belgian gene bank collection. SSR analysis was preferred because AFLP was technically more demanding and more prone to scoring errors. To assess the genetic diversity, we grouped material from the gene banks according to topography of the location from which the accessions were originally collected (river system or regions separated by mountains). Genetic diversity was expressed in terms of the following parameters: percentage of polymorphic loci, observed and effective number of alleles, and Nei's expected heterozygosity or gene diversity (for AFLP). Genetic diversity varied from region to region and depended, to some extent, on the marker system used. The most unique alleles were identified in the Danube region (Austria), the Rhône region (France), Italy, the Rijn region (The Netherlands), and the Ebro region (Spain). In general, the diversity was largest in the material collected from the regions in Southern Europe. Dendrograms and principal component analysis resulted in a clustering according to topography. Material from the same river systems, but from different countries, clustered together. The genetic differentiation among the regions (F(st)/G(st)) was moderate.

Dense genetic linkage maps of three Populus species (Populus deltoides, P. nigra and P. trichocarpa) based on AFLP and microsatellite markers.

Populus deltoides, P. nigra, and P. trichocarpa are the most important species for poplar breeding programs worldwide. In addition, Populus has become a model for fundamental research on trees. Linkage maps were constructed for these three species by analyzing progeny of two controlled crosses sharing the same female parent, Populus deltoides cv. S9-2 x P. nigra cv. Ghoy and P. deltoides cv. S9-2 x P. trichocarpa cv. V24. The two-way pseudotestcross mapping strategy was used to construct the maps. Amplified fragment length polymorphism (AFLP) markers that segregated 1:1 were used to form the four parental maps. Microsatellites and sequence-tagged sites were used to align homoeologous groups between the maps and to merge linkage groups within the individual maps. Linkage analysis and alignment of the homoeologous groups resulted in 566 markers distributed over 19 groups for P. deltoides covering 86% of the genome, 339 markers distributed over 19 groups for P. trichocarpa covering 73%, and 369 markers distributed over 28 groups for P. nigra covering 61%. Several tests for randomness showed that the AFLP markers were randomly distributed over the genome.

[Oxygen affinity and regeneration capacity of SAG-M and PAGGS-M stored erythrocytes]. / Sauerstoffaffinität und Regenerationsfähigkeit in SAG-M und PAGGS-M gelagerter Erythrozyten.

In order to estimate the leftward shift of the oxygen dissociation curve of hemoglobin following storage of red blood cells (rbc) in the additive solutions SAG-M and PAGGS-M, respectively, we performed blood gas analyses after equilibrating the cells with a gas mixture containing 4% of O2 and 5% of CO2 at pH 7.4 and 37 degrees C. Additionally, we took advantage of these nearly physiological conditions to measure the recovery of the hemoglobin function in vitro. We observed a good correlation between 2,3-BPG and p50 (i.e. the oxygen tension, at which hemoglobin is half-saturated with oxygen). Within the first 3 weeks of storage, the 2,3-BPG content fell to one fifth of its original value, whereas the p50 declined from 26.6 to about 20 mm Hg. Compared to fresh cells, rbc stored for longer than 3 weeks will thus deliver 30% less oxygen to the myocardium. The rbc's ability to restore these parameters remained unchanged throughout 7 weeks of storage.