DNA damage in canine transmissible venereal tumor cells

O Tumor Venéreo Transmissível (TVT) tem sido classificado de acordo com o tipo celular predominante da seguinte forma: linfocitóide, plasmocitóide e misto. Vários graus de agressividade com grande variedade de comportamento biológico, têm sido descritos de acordo com as morfologias das células do TVT. O presente estudo teve como objectivo investigar o nível de danos no DNA nos três tipos de células do TVT, visando uma melhor compreensão dos mecanismos relacionados com a agressividade dessa neoplasia. Um total de 35 cães, sem restrição quanto à idade, sexo ou raça, e com diagnóstico clínico e citológico de TVT foram avaliados. Amostras de células foram obtidas a partir de 35 tumores, por aspiração com agulha fina, e realizada citologia e análise dos danos no DNA, pelo Ensaio Cometa. Dos 35 casos de TVT, 12 (34,3%) foram plasmocitóide, 11 (31,4%) linfocitóide, e 12 (34,3%) misto. Estatísticamente (p <0,05) o TVT linfocitóide apresentou maior nível de danos no DNA quando comparado com os outros dois tipos.

Colour, contrast & perception: A design guidance for internal built environments

Conducts a study into how contrast could be established when using colours frequently used in everyday environments, and how different adjacent colours had to be in terms of chromaticity, saturation and/or hue in order for a difference to be discerned between them by fully sighted people and most visually impaired people. Location within a building where contrast would have the greatest benefits is considered. Relates the philosophy behind design procedures and decisions to meet the objectives.

Synthesis of alpha-galactooligosaccharides with alpha-galactosidase from Lactobacillus reuteri of canine origin

Crude cell-free extracts from Lactobacillus reuteri grown on cellobiose, maltose, lactose and raffinose were assayed for glycosidic activities. When raffinose was used as the carbon source, alpha-galactosidase was produced, showing the highest yield at the beginning of the stationary growth phase. A 64 kDa enzyme was purified by ultra- and gel filtration, and characterized for its hydrolytic and synthetic activity. Highest hydrolytic activity was found at pH 5.0 at 50 degreesC (K-M 0.55 mM, V-max 0.80 mumol min(-1) mg(-1) of protein). The crude cell-free extract was further used in glycosyl transfer reactions to synthesize oligosaccharides from melibiose and raffinose. At a substrate concentration of 23% (w/v) oligosaccharide mixtures were formed with main products being a trisaccharide at 26% (w/w) yield from melibiose after 8 h and a tetrasaccharide at 18% (w/w) yield from raffinose after 7 h. Methylation analysis revealed the trisaccharide to be 6' alpha-galactosyl melibiose and the tetrasaccharide to be stachyose. In both cases synthesis ceased when hydrolysis of the substrate reached 50%.

Modulation of anti-pathogenic activity in canine-derived Lactobacillus species by carbohydrate growth substrate

Aims: To investigate the effect of various carbon sources on the production of extracellular antagonistic compounds against two Escherichia coli strains and Salmonella enterica serotype Typhimurium by three canine-derived lactobacilli strains. Methods and Materials: Cell-free preparations, pH neutralized, were used in antibiotic disc experiments as an initial screening. The bacteria/carbohydrate combinations that showed inhibition of the growth of those pathogens, were further investigated in batch co-culture experiments. The cell-free supernatants of the cultures, that decreased the population number of the pathogens in the co-culture experiments to log CFU ml(-1) less than or equal to 4, were tested for inhibition of the pathogens in pure cultures at neutral and acidic pH. Conclusions: The results showed that the substrate seems to affect the production of antimicrobial compounds and this effect could not just be ascribed to the ability of the bacteria to grow in the various carbon sources. L. mucosae, L. acidophilus and L. reuteri, when grown in sugar mixtures consisting of alpha-glucosides (Degree of Polymerization (DP) 1-4) could produce antimicrobial compounds active against all three pathogens in vitro. This effect could not be attributed to a single ingredient of those sugar mixtures and was synergistic. This inhibition had a dose-response characteristic and was more active at acidic pH. Significance and Impact of the Study: Knowledge of the effect that the carbon source has on the production of antimicrobial compounds by gut-associated lactobacilli allows the rational design of prebiotic/probiotic combinations to combat gastrointestinal pathogens.

Slackia faecicanis sp nov., isolated from canine faeces

Morphological, biochemical and molecular genetic studies were carried out on an unknown non-spore-forming, Gram-positive, rod-shaped bacterium that was isolated from dog faeces. The bacterium grew under strictly anaerobic conditions, was asaccharolytic, and possessed a relatively high G + C content of 61 mol%. Phylogenetic analysis based on comparative 16S rRNA gene sequencing showed that the unidentified bacterium was a member of the family Coriobacteriaceae and represents a hitherto unknown subline within the genus Slackia. Based on the presented findings, a novel species, Slackia faecicanis sp. nov., is described. The type strain of Slackia faecicanis is 5WC12(T) (=CCUG 48399(T)=CIP 108281(T)).

Allobaculum stercoricanis gen. nov., sp nov., isolated from canine feces

Morphological, biochemical, and molecular genetic studies were performed on an unknown anaerobic, catalase-negative, nonspore-forming, rod-shaped bacterium isolated from dog feces. The unknown bacterium was tentatively identified as a Eubacterium species, based on cellular morphological and biochemical tests. 16S rRNA gene sequencing studies, however, revealed that it was phylogenetically distant from Eubacterium limosum, the type species of the genus Eubacterium. Phylogenetically, the unknown species forms a hitherto unknown sub-line proximal to the base of a cluster of organisms (designated rRNA cluster XVI), which includes Clostridium innocuum, Streptococcus pleomorphus, and some Eubacterium species. Based on both phenotypic and phylogenetic criteria, it is proposed that the unknown bacterium be classified as a new genus and species, Allobaculum stercoricanis. Using a specific rRNA-targeted probe designed to identify Allobacultan stercoricanis, in situ hybridisation showed this novel species represents a significant organism in canine feces comprising between 0.1% and 3.7% of total cells stained with DAPI (21 dog fecal samples). The type strain of Allobaculum stereoricanis is DSM 13633(T) = CCUG 45212(T). (C) 2004 Elsevier Ltd. All rights reserved.