Leishmania-specific isotype levels and their relationship with specific cell-mediated immunity parameters in canine leishmaniasis

In the current retrospective study, Leishmania infantum-specific IgG, IgA and IgM levels were determined by ELISA in 106 untreated dogs with clinically-patent leishmaniasis (Sx) and in 171 clinically healthy dogs (Asx) from Spain to investigate the relationship between these Ig isotypes and clinical status. In addition, we studied if different Leishmania-specific humoral pattern exists between Asx dogs with and without cellular mediated immunity (CMI). Fifty-six dogs were assessed by means of lymphoproliferation assay (LPA), interferon production (IFN) and leishmanin skin test (LST), 71 dogs by means of both LPA and IFN and 44 only by LST. Both Sx and Asx dogs produced Leishmania-specific IgG, IgA and IgM antibodies, however the levels and proportion of positive dogs for each Ig isotype were significantly higher in Sx than in Asx ones (P<0.001). Analysis of immunological profiles determined for each cellular technique (positive and negative cellular response for each technique combined with positive or negative specific humoral response) showed that Asx dogs constituted a high heterogeneous group. No correlations were observed between CMI tests and specific IgG or IgM levels. However, a significant inverse correlation was demonstrated between specific IgA levels and LPA response (Spearman's r=-0.220; P=0.035). In general, the low correlation detected between CMI tests and isotype levels might indicate that the immune response is not strongly polarized in the majority of Asx dogs. Additionally, this study suggests that dogs developing T-cell response are probably able to avoid the dissemination of the parasite at least to mucosal surfaces and, as a consequence, to produce low or background specific IgA levels. Further studies are needed to investigate the relationship between specific IgA and parasite load, especially at mucosal site.     

Sunflower mutant containing high levels of palmitic acid in high oleic background

A new sunflower mutant, CAS-12, was obtained, which has both high palmitic (≈30%) and high oleic acid contents, and also a substantial amount of palmitoleic acid (≈7%). The mutant was selected after X-ray irradiation of dry seeds of the inbred line BSD-2-423, which had normal palmitic (≈3%) and high oleic (≈88%) acid levels. The increase of palmitic and palmitoleic acids occurred at the expense of the oleic acid content, which decreased to around 55% in respect to the original line. Linoleic acid content is always under 5%. Palmitic and palmitoleic acid levels were similar to those of the high palmitic mutant CAS-5 obtained in a previous programme from a low oleic line isogenic to BSD-2-423 using a similar mutagenic treatment. In that previous programme we also selected three high stearic acid mutants using chemical mutagenic treatment on the same sunflower line (RDF-1-532). We attempted to obtain mutants in other lines but were unsuccessful. The isolation of similar mutants in isogenic parental lines illustrates the importance of the genetic background in the development of specific mutants with an altered seed oil fatty acid composition. The oil of this mutant will increase the range of potential uses of sunflower oil. This revised version was published online in July 2006 with corrections to the Cover Date.     

Zinc transformations in acidic soil and zinc efficiency on maize by adding six organic zinc complexes

Experiments under laboratory and greenhouse conditions were conducted to study the response of maize (Zea mays L.) to Zn fertilizer applications (Zn-phenolate, Zn-EDDHA, Zn-EDTA, Zn-lignosulfonate, Zn-polyflavonoid, and Zn-heptagluconate) in an Aquic Haploxeralf soil. The application of Zn complexes significantly increased Zn uptake by the plant compared with that in the control soil. The highest enhancements were obtained in soil treated with Zn-EDTA, Zn-lignosulfonate, and Zn-EDDHA. The highest percentages of Zn taken up by the plants occurred when 20 mg x kg(-1) Zn was applied as Zn-EDTA fertilizer and 10 mg x kg(-1) as Zn-lignosulfonate fertilizer. In the greenhouse experiment, Zn speciation in soil after harvesting showed that almost all Zn was found in the residual fraction followed by metal in the water-soluble plus exchangeable fraction and metal bound to organic matter. The most effective fertilizers maintaining Zn in the most labile fractions were Zn-phenolate, Zn-EDTA, and Zn-lignosulfonate. Conversely, in the incubation experiment, only a small percentage of Zn was found in the water-soluble plus exchangeable fraction and no differences in the Zn distribution were observed between the different fertilizer treatments. The micronutrient content in maize was positively correlated with the water-soluble plus exchangeable Zn as well as with the available Zn determined by the diethylenetriaminepentaacetic acid and Mehlich-3 methods, in the greenhouse experiment. Results of this study showed that the incubation experiment in acidic soil is not a suitable tool to establish the different effectiveness of Zn chelates in plants.     

Fumonisin B-glucose reaction products are less toxic when fed to swine

The effects of fumonisin B-glucose reaction products in swine diets was examined. Pigs were fed diets containing 528 micromol of total fumonisin B/kg (FB), 528 micromol of total FB-glucose adducts/kg (FB-G, 122 micromol of unreacted FB/kg), or 0 micromol of total FB/kg for 15 days to test the efficacy of the FB-G reaction products in detoxifying FB. Weight gain in FB pigs was lower than in FB-G or controls, which was correlated with feed intake reduction in FB pigs. Serum aspartate aminotransferase, gamma-glutamyltransferase, and total bilirubin in FB pigs were higher than in FB-G or control pigs. Serum sphinganine/shingosine ratios in FB pigs were higher than in FB-G or control pigs. Microscopic examination of tissues from FB pigs showed generalized liver necrosis and apoptosis with marked cellular pleomorphism and disorganized hepatic cords. The liver and kidneys in the FB-G group appeared to be normal. Tissues of controls were free of lesions. Results suggest that dietary FB-G products are less toxic to swine and may provide an detoxification approach in instances of widespread FB grain contamination (p < 0.05).     

Fungicide dissipation curves in winemaking processes with and without maceration step

The evolution of residual levels of four fungicides (cyprodinil, fludioxonil, pyrimethanil, and quinoxyfen) during the elaboration of three types of wine with maceration (traditional red wine, carbonic maceration red wine, and red wine of long maceration and prefermentation at low temperature) and two types of wine without maceration (rose and white) has been studied. The disappearance curves of each fungicide have been analyzed during the period of each winemaking process (21 days) and during the different enological steps involved in the elaborations. The residual levels of fludioxonil reduce most quickly during the winemaking processes without maceration, whereas the decrease in levels of pyrimethanil was the slowest in practically all cases (with and without maceration). During carbonic maceration winemaking, the decay constant of cyprodinil was greater than that of the other pesticides in all assays (time and steps).     

Volatile compounds in Hispánico cheese manufactured using a mesophilic starter,a thermophilic starter,and bacteriocin-producing Lactococcus lactis subsp. lactis INIA 415

The effect of the addition of Lactococcus lactis subsp. lactis INIA 415, a strain harboring the structural genes of nisin Z and lacticin 481, on the formation of volatile compounds in Hispánico cheese manufactured with a mesophilic starter or with the mesophilic starter and a thermophilic starter was investigated. Addition of bacteriocin-producing L. lactis subsp. lactis INIA 415 to milk enhanced the formation of 2-methyl-propanal, 2-methylbutanal, 3-methylbutanal, 2-methyl-1-propanol, 3-methyl-1-butanol, 1-octanol, 2-butanone, and 2,3-butanedione. On the other hand, addition of thermophilic starter enhanced the formation of acetaldehyde, ethanol, 3-methyl-2-buten-1-ol, ethyl butanoate, ethyl hexanoate, 2-butanone, and 2,3-butanedione in Hispánico cheese. Stepwise discriminant analysis using the relative abundances of volatile compounds classified cheeses by type of starter, with function 1 related to thermophilic starter and function 2 to bacteriocin producer.     

Do ecological and silvicultural factors influence acorn mass in Holm Oak (southwestern Spain)?

The effect of orientation, location, year, and pruning treatment on mean acorn mass in two open woodland experimental locations (Huelva, South-Western Spain) of Holm Oak (Quercus ilex L. subsp. ballota [Desf.] Samp.) was analyzed during 2001–2006. Data were analyzed by using a mixed linear model, where the covariates were tree size parameters (circumference at 80 cm height, crown size), topographic position (wet index and flow length), intraspecific competition, total acorn crops per tree (weight and number), and climatic parameters. Average estimated acorn mass was 3.17 g acorn^?1 in the Calañas location and 4.12 g acorn^?1 in the San Bartolomé location, with significant differences between locations, among individual trees and across years. Acorns from the south sides of trees were significantly heavier than those at other positions. The effect of pruning treatment and the interactions location × treatment and treatment × year were not significant. Our study provides no evidence that pruning affects acorn mass. None of the analyzed covariates related to tree size, topographic position and intraspecific competition explained the difference among trees, suggesting that heritable factors play an important role. Specific climatic parameters during September, the most important month for acorn growth, may explain the effects of year and location × year on acorn mass. In addition, there appeared to be a “trade-off” between acorn mass and number of acorns.     

Illinois Soil Nitrogen Test Method Optimization for Analysis of Temperate Mineral Grassland Soils

ABSTRACT

A reliable and practical test that can provide timely measurements of the levels of mineralizable nitrogen (MN) in soil is critical for improving the accuracy of N fertilizer applications for grassland and crops. The Illinois soil N test (ISNT) is considered to be a good estimate of MN, once soils are grouped according to soil characteristics such as the drainage type and sampling depth. To date, development and evaluation of the ISNT method has been conducted using arable soils mainly in North America where, in general, soils have lower levels of soil organic matter (SOM) compared to temperate grassland soils. We evaluated the effects of two pre-treatment soil aggregate sizes of <1 mm and <2 mm on the yield and recovery of MN (1) across temperate grassland soil types, and (2) across a 6-h interval diffusion period. No significant difference existed in the concentrations of ISNT-N between the two soil aggregate sizes of each soil type. For both aggregate sample sizes, the recovery of spiked amino sugar-N glucosamine from a temperate grassland soil was generally linear until hour 5, after which the quantities of recovered N diminished. Although N recovery after 6 h of diffusion at 50°C (±1°C) was less than 100% in both aggregate size samples, the response models indicated that the standard ISNT protocol using a 5-h diffusion period is appropriate for temperate grassland soils. The incomplete recovery of N in these mineral soils suggested that the protocol could be further optimized for temperate soils with high organic matter content and additional evaluation of the temperature during diffusion within an enclosed environment may be required using N (spiked glucosamine-N) recovery studies.     

Olive fruit cell wall: degradation of pectic polysaccharides during ripening

Olive fruits at three stages of ripening (green, cherry, and black) have been studied. After cell wall isolation, the compositions of the cell wall and that of the phosphate-soluble polysaccharides were determined. In cell walls, decreases in arabinose, xylose, glucose, and uronic acid levels were observed, together with a slight increase in mannose on ripening. At the beginning of ripening, fragments of pectic polymers were the major constituents of the phosphate-soluble fraction, with the hemicellulosic ones increasing toward the end of the process. The molecular weight of the fragments solubilized was approximately 6 kDa. After cell wall fractionation, the pectic polysaccharides soluble in imidazole and sodium carbonate were also studied. In both fractions, between the green and cherry stages of ripening, a significant loss of homogalacturonans took place. Between the cherry and black stages of ripening, rhamnogalacturonan side chains were also released in addition to homogalacturonans. In any of the pectic fractions, changes in apparent molecular weight were quantified.     

Controlled release of carbofuran from an alginate-bentonite formulation: water release kinetics and soil mobility

The insecticide-nematicide carbofuran was incorporated in alginate-based granules to obtain controlled-release (CR) properties. The basic formulation [sodium alginate (1.61%)-carbofuran (0. 59%)-water] was modified by addition of sorbents. The effect on carbofuran release rate, caused by the incorporation of natural and acid-treated bentonite (0.5 and 1.0 M H(2)SO(4)) in alginate formulation, was studied by immersion of the granules in water under shaking. The time taken for 50% of the active ingredient to be released into water, t(50), was longer for those formulations containing natural bentonite (6.1 h) or acid-treated bentonite (9.0 and 11.7 h for 0.5 and 1.0 M H(2)SO(4) treatments, respectively) than for the preparation without bentonite (4.7 h). It appears from the results that the release of carbofuran from the various formulations is controlled by a diffusion mechanism according to the n values obtained, which were close to 0.5 in all cases. The mobility of carbofuran from alginate-based CR formulations was investigated by using soil columns packed with a clay soil (53% clay and 0.08% organic matter). Two alginate-based CR formulations containing natural bentonite or acid-treated bentonite (0.5 M H(2)SO(4)) were compared to technical grade carbofuran. The use of alginate-based CR formulations resulted in a reduction of the leached amount of carbofuran compared with the total amount of pesticide leached using the technical product (50 and 75% for CR granules containing natural and acid-treated bentonite, respectively). Alginate-bentonite CR formulations might be efficient systems for reducing carbofuran leaching in clay soils, which would reduce the risk of groundwater pollution.