Characterization of biological activities of feline eosinophil granule proteins

OBJECTIVE:To characterize eosinophil granule-derived proteins in cats. SAMPLE POPULATION: Eosinophils collected via peritoneal lavage from 2 cats. PROCEDURE: The cats were infested orally with Toxocara canis eggs and subsequently challenge-exposed with T. canis antigen injected IP to induce peritoneal eosinophilia; eosinophils were collected via peritoneal lavage. Eosinophil granule proteins were acid-extracted, separated by gel-filtration chromatography, and examined for their peroxidase, ribonuclease, and bactericidal activities; the N-terminal sequence of some of these proteins was determined and compared with homologue proteins from other species. RESULTS: 3 protein peaks were separated in the chromatogram. The first peak had both peroxidase and bactericidal activities. The second peak had ribonuclease and bactericidal activities, and the N-terminal sequence of the major protein was homologous with that of proteins of the ribonuclease A superfamily, including eosinophil ribonucleases from humans and other animal species. The third protein peak had bactericidal activity, and the N-terminal sequence of the major protein was homologous with that of human and murine major basic proteins. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that feline eosinophil granules contain major basic protein and eosinophil-associated ribonuclease and the granule proteins have peroxidase, ribonuclease, and bactericidal activities. In cats, characterization of eosinophil granule proteins may be useful in elucidation of the mechanism of tissue damage in eosinophil-associated diseases and development of new treatment options for those diseases. In addition, the identification of conserved structure and function of eosinophil granule proteins in cats is relevant from an evolutionary viewpoint.     

Combined Effects of Nitrogen Concentration and Seasonal Changes on the Production of Lipids in Nannochloropsis oculata

Instead of sole nutrient starvation to boost algal lipid production, we addressed nutrient limitation at two different seasons (autumn and spring) during outdoor cultivation in flat panel photobioreactors. Lipid accumulation, biomass and lipid productivity and changes in fatty acid composition of Nannochloropsis oculata were investigated under nitrogen (N) limitation (nitrate:phosphate N:P 5, N:P 2.5 molar ratio). N. oculata was able to maintain a high biomass productivity under N-limitation compared to N-sufficiency (N:P 20) at both seasons, which in spring resulted in nearly double lipid productivity under N-limited conditions (0.21 g L⁻¹ day⁻¹) compared to N-sufficiency (0.11 g L⁻¹ day⁻¹). Saturated and monounsaturated fatty acids increased from 76% to nearly 90% of total fatty acids in N-limited cultures. Higher biomass and lipid productivity in spring could, partly, be explained by higher irradiance, partly by greater harvesting rate (~30%). Our results indicate the potential for the production of algal high value products (i.e., polyunsaturated fatty acids) during both N-sufficiency and N-limitation. To meet the sustainability challenges of algal biomass production, we propose a dual-system process: Closed photobioreactors producing biomass for high value products and inoculum for larger raceway ponds recycling waste/exhaust streams to produce bulk chemicals for fuel, feed and industrial material.     

Regeneration and genetic transformation of Spanish rice cultivars using mature embryos

To establish a plant regeneration system from embryogenic callus derived from mature rice embryos, the addition of aminoacids and the effect of two macronutrient solutions MSD and N6D to the basal callus induction medium was tested in three Spanish varieties, Senia, Tebre and Bahia. Aminoacids enhanced the production of embryogenic callus in Tebre and Senia whereas in the case of Bahia, embryogenic callus, which gave rise to a high rate of differentiated shoots, was induced without aminoacids. The macronutrient solution had also to be adjusted for each variety. Pre-regeneration treatment with ABA significantly improved the regeneration rate in all media tested, independently of the media in which the embryogenic callus were induced. In a comparison of growth regulators, BA yielded more shoots than Kin in all varieties whereas the effect of the auxins NAA or IAA was dependent on the variety. Transgenic plants from the three varieties were obtained via an Agrobacterium tumefaciens transformation system, using the optimised culture media. This revised version was published online in July 2006 with corrections to the Cover Date.     

Relationships among the composition and physicochemical properties of starches with the characteristics of their films

The physical, molecular, and functional properties of corn, cassava, and yam starches were related to the film properties of these starches. Corn, cassava, and yam starches contained 25%, 19%, and 30% amylose, respectively. Amylose from yam starch showed the smallest molecular weight among the starches and amylopectin from corn starch the smallest molecular weight. Cassava starch presented a higher amylopectin content, and its gels and films were less strong, more transparent, and more flexible than corn and yam films. Plasticized films of the three starches were more flexible, with a higher strain and lower stress at break when the glycerol content increased. Unplasticized films were brittle and had water vapor permeability values ranging from 6.75 x 10(-10) to 8.33 x 10(-10) g m(-1) s(-1) Pa(-1). These values decreased when the glycerol content reached 20 g/100 g of starch because a more compact structure was formed. Then, at a glycerol content of 40 g/100 g of starch, the WVP increased because the film matrixes became less dense.     

Effects of yam starch films on storability and quality of fresh strawberries (Fragaria ananassa)

Yam starch films, formulated with yam starch (4.00 g/100 g of solution) and glycerol (1.30 and 2.00 g/100 g of solution) in filmogenic solution, were employed as packaging to extend storage life of strawberries stored at 4 degrees C and 85% RH. The effects of yam starch films on fruits were compared to the effect of PVC (poly(vinyl chloride)) packaging. Starch and PVC films significantly reduced decay of the fruits compared to control. Compared to starch films, PVC presented the better behavior on weight and firmness retention of fruits, especially in the last 7 days of storage. Considering microbiological counts, the shelf life of control fruits was 14 days, and of all packaged samples, stored at same conditions, was 21 days. Two different formulations of yam starch film were tested and had different mechanical properties as a function of glycerol content (1.30 and 2.00 g/100 g of solution) but showed no difference when employed as strawberries packaging.