Immune and clinical parameters associated with Leishmania infantum infection in the golden hamster model

For experimental infections with viscerotropic strains of Leishmania, a suitable animal model is not yet defined. In the present work, we have reappraised the use of golden hamster (Mesocricetus auratus) as an experimental model for infection with Leishmania infantum. Groups of hamsters were challenged by the intracardial route with doses ranging from 10(3) to 10(5) infectious promastigotes and the animals were monitored for 1-year follow-up period. The outcome of the infection was assessed by clinical symptoms of leishmaniasis, parasite loads in both liver and spleen, humoral response to Leishmania antigens and antibody levels in kidneys. The humoral response was analysed using either crude antigens (by ELISA and Western blotting) or several recombinant Leishmania antigens (Hsp70, Hsp83, LiP2a, LiP2b, H2A, H3 and KMP-11). From the analysis of all these parameters, we established the existence of three groups of animals: symptomatic or susceptible, oligosymptomatic, and resistant. Given the parallelism existing between the outcomes of Leishmania-infection in hamsters, dogs and humans, we believe that our data illustrate that the hamster is an excellent experimental model to study visceral leishmaniasis and for the design of vaccine development.     

The effect of pig farming on copper and zinc accumulation in cattle in Galicia (north-western Spain)

Copper and zinc are frequently added at high concentrations to pig diets as growth promoters. Livestock grazing pasture contaminated with pig slurry may, therefore, be at risk from excessive intake of these elements. High liver copper concentrations have been detected in cattle from the agricultural region of Galicia (NW Spain), especially where there is intensive pig farming. The aim of this study was to evaluate whether pig farming does affect accumulation of copper and zinc in cattle in Galicia. Hepatic copper and zinc concentrations in calves were elevated in areas with naturally high levels of these elements in the soil. The densities of young pigs (piglets and growing-finishing pigs), but not reproductive sows, also influenced copper accumulation in calves. Liver copper levels in calves were significantly and positively related to the density of young pigs in the region. In areas with the highest pig densities, more than 20% of the cattle analysed had hepatic copper concentrations that exceeded the potentially toxic concentration of 150 mg/kg fresh weight. There was no evidence that zinc accumulation in calves was affected by pig density.     

A distinct Mendelian autosomal recessive syndrome involving the association of anotia, palate agenesis, bifid tongue, and polydactyly in the dog.

A presumed genetic syndrome is described in a family of St. Bernards. Four identically affected littermates presented the association of palate agenesis, anotia, incomplete bifid tongue, preaxial hind paw polydactyly, and an extra thoracic vertebra and rib. Pedigree analysis is compatible with an autosomal recessive gene.     

Organogenic responses of Pinus pinea cotyledons to hormonal treatments: BA metabolism and cytokinin content

Isolated cotyledons from mature Pinus pinea L. embryos were cultured in vitro in a factorial combination of 4.4, 10 and 44.4 microM N6-benzyladenine (BA) for 2, 4, 8, 16 and 35 days to optimize shoot regeneration. Incubation of explants in 44.4 microM BA for 4 days, in place of the standard incubation in 4.4 microM BA for 35 days, reduced the entire culture period to 4 weeks. Shortening the culture period had no significant effect on the caulogenic response or the number of buds formed per cotyledon. To establish the relationship between key moments in the caulogenic process induced by 4.4 microM BA and the endogenous concentrations of the active forms of BA and other isoprenoid-type cytokinins (CKs), we examined uptake, metabolism and amount of BA, as well as the amounts of zeatin, dihydrozeatin and their ribosides in P. pinea cotyledons after 1, 2, 6, 12 and 24 h, and 2, 4, 8, 16 and 35 days of exposure to 8-[14C]BA. Uptake and release of BA were associated with water movement between explants and the medium during the first 8 days of culture. The interconvertible forms of BA were the main metabolites formed in the tissues. Inactivation of BA as a result of conjugation or oxidation was insignificant. The endogenous concentration of BA + N6-benzyladenosine was 20-fold higher than the exogenously applied BA during the competence acquisition phase (Days 0-3). The concentration of isoprenoid-type CKs also increased 16-fold and then decreased during this time. Induction of shoot buds (Days 4-8) was characterized by a second peak of BA uptake by explants that triggered the synthesis of N6-benzyladenosine-5 -monophosphate and by the maintenance of isoprenoid-type CKs. Reestablishment of CK homeostasis marked the shift from the induction phase to the shoot development phase in this organogenic process (Days 8-12).     

Determination of tetracycline antibiotic residues in edible swine tissues by liquid chromatography with spectrofluorometric detection and confirmation by mass spectrometry

A sensitive and specific method is described for the simultaneous determination of oxytetracycline, tetracycline (TC), and chlortetracycline residues in edible swine tissues, by combining liquid chromatography with spectrofluorometric and mass spectrometry detection. The procedure involved a preliminary extraction with EDTA-McIlvaine buffer acidified at pH 4.0, followed by solid-phase extraction cleanup using a polymeric sorbent. The liquid chromatography analysis was performed with spectrofluorometric detection after postcolumn derivatization with magnesium ions. The limits of quantification were 50 microg/kg for muscle and 100 microg/kg for kidney tissues. The recovery values were greater than 77.8% for muscle and 65.1% for kidney. The method has been successfully used for the quantification of tetracyclines in swine tissues samples. The selective liquid chromatography mass spectrometric analysis for confirmation of oxytetracycline in one positive swine muscle sample was made by atmospheric pressure chemical ionization (APCI). The APCI mass spectra of the TCs gave the protonated molecular ion and two typical fragment ions, required for their confirmation in single ion monitoring scan mode in animal tissues.     

Detection of Escherichia coli Serotype 0157 in Beef Carcasses and Faecal Material

Veterinary Research Communications -     

Gas chromatographic analysis of total fatty acids in cider

This paper reports the composition of total fatty acids in an apple beverage, cider. Fatty acids are present in the free or esterified form and contribute to both the flavor and foam properties of cider. Fatty acids were separated and identified as methyl esters by GC-MS, and 12 of these were subsequently determined by GC-FID. The major fatty acids found in cider were caproic, caprylic, capric, and palmitic acid, the saturated acids predominating over the unsaturated ones. The proposed method was applied to 59 ciders from three consecutive harvests (1996, 1997, and 1998), which were made by 19 cider-makers from the region of Asturias (Spain). Linear discriminant analysis of fatty acids in these samples allowed selection of palmitoleic, pentadecanoic, linoleic, myristic, and linolenic acid as the most predictive variables to differentiate ciders made from apples grown in the Asturias region (1997 harvest) and ciders made from apples grown outside this region (1996 and 1998 harvests).     

Acrylamide formation from asparagine under low moisture Maillard reaction conditions. 2. Crystalline vs amorphous model systems

The formation of acrylamide was investigated in model systems based on asparagine and glucose under low moisture Maillard reaction conditions as a function of reaction temperature, time, physical state, water activity, and glass transition temperature. Equimolar amorphous glucose/asparagine systems with different water activities were prepared by freeze drying and were shown to quickly move to the rubbery state already at room temperature and a water activity of above 0.15. The acrylamide amounts were correlated with physical changes occurring during the reaction. Pyrolysis and kinetics of acrylamide release in amorphous and crystalline glucose/asparagine models indicated the importance of the physical state in acrylamide formation. In amorphous systems, acrylamide was generated in higher concentrations and at lower temperatures as compared to the crystalline samples. Time and temperature are covariant parameters in both systems affecting the acrylamide formation by thermal processes. On the other side, the water activity and glass transition temperature do not seem to be critical parameters for acrylamide formation in the systems studied.     

Effect of red grapes co-winemaking in polyphenols and color of wines

The red grapes co-winemaking effect on phenolic fraction and wine color has been studied for the first time, where Monastrell was comacerated and cofermentated with Cabernet Sauvignon and Merlot. Changes in the relative abundance of anthocyanins were observed as well as hyperchromic shifts at 530 and 620 nm; these effects remain constant after aging. Co-winemaking also favored copigmentation, giving way to more stable anthocyanins and facilitating their polymerization. With regard to color evolution, the mixture of Monastrell with Merlot grapes was more appropriate than with Cabernet Sauvignon for aging wines in oak barrels. The extent of copigmentation was more important in young wines than in aged wines. This is mainly due to the self-anthocyanin monomer reactions in the case of young wines, whereas in aged wines copigmentation is mainly due to the reaction between the anthocyanins and other polyphenolic cofactors. Discriminant analysis showed the possibility of differentiating wines according to the aging time and the type of wine, with color parameters (color intensity, OD 620 nm, and OD 520 nm) being the most important discrimination variables in the first case and petunidin-3-glucoside and peonidin-3-glucoside contents in the second case.