Aránzazu Peña

Association of interleukin-1β and interleukin-1 receptor antagonist genes with disease severity in MS

Objective: To investigate whether polymorphisms in the interleukin (IL)-1β and IL-1 receptor antagonist (IL-1RA) genes are associated with both susceptibility to and clinical characteristics of MS. Background: Genetic susceptibility to MS is determined by many partially identified genes. The genes encoding various cytokines are logical candidates for MS susceptibility and phenotype. Methods: Genotypes were determined from 148 patients with clinically definite MS and 98 healthy controls. All the patients were unrelated, Dutch, and white. Patient files were reviewed for disease type, initial symptoms, age at onset of disease, and rate of disease progression. Results: No significant differences in genotypes, allele frequencies, or carrier frequencies were found between MS patients and healthy controls. Stratification for disease type (relapsing-remitting, primary progressive, or secondary progressive) did not provide significant differences between patients and controls. However, a specific IL-1RA/IL-1β combination was associated with disease severity. MS patients with the IL-1RA allele 2+/IL-1β allele 2− combination had a higher rate of progression on the Expanded Disability Status Scale when compared with the other possible combinations (p = 0.007). Conclusions: IL-1RA and IL-1β are disease severity genes rather than disease susceptibility genes. Furthermore, these gene polymorphisms may define subgroups of patients with a worse prognosis.

Antimicrobial chemicals in hoopoe preen secretions are produced by symbiotic bacteria

Animals frequently use metabolites produced by symbiotic bacteria as agents against pathogens and parasites. Secretions from the preen gland of birds are used for this purpose, although its chemicals apparently are produced by the birds themselves. European hoopoes Upupa epops and green woodhoopoes Phoeniculus purpureus harbour symbiotic bacteria in the uropygial gland that might be partly responsible for the chemical composition of secretions. Here we investigate the antimicrobial activity of the volatile fraction of chemicals in hoopoe preen secretions, and, by means of experimental antibiotic injections, test whether symbiotic bacteria living within the uropygial gland are responsible for their production. Hoopoes produce two different kinds of secretions that differ drastically in their chemical composition. While the malodorous dark secretions produced by nestlings included a complex mix of volatiles, these chemicals did not appear in white secretions produced by non-nesting birds. All volatiles detected showed strong antibacterial activity, and a mixture of the chemicals at the concentrations measured in nestling glands inhibited the growth of all bacterial strains assayed. We found support for the hypothesized role of bacteria in the production of such antimicrobial chemicals because experimental clearance of bacteria from glands of nestlings with antibiotics resulted in secretions without most of the volatiles detected in control individuals. Thus, the presence of symbiotic bacteria in the uropygial gland provides hoopoes with potent antimicrobials for topical use.

Use of arthropods for the evaluation of the olive‐orchard management regimes

Abstract  1 The presence and abundance of arthropods were compared in three olive orchards under organic, integrated and conventional management regimes. In each olive orchard, trees were sampled in the canopy by beating branches and soil arthropods by placing pitfall traps. Contrary to expectations, the highest abundance of arthropods occurred in the integrated management orchard. The most abundant groups were Formicidae and the species Euphyllura olivinae (Homoptera: Psyllidae).

Sex pheromone of European corn borer. - Ostrinia nubilalis: Polymorphism in various laboratory and field strains

Sex gland extracts ofOstrinia nubilalis females collected in the wild or laboratory-reared from Switzerland, Italy, and Hungary were analyzed. Individuals collected in the north of Switzerland contained (Z)- and (E)-11-tetradecenyl acetate at the approximate ratio of 97∶3 (Z type), in accordance with field responses of males and previous findings. On the other hand, females from a laboratory culture derived from field collections made in the same area and reared for four to five generations contained theZ andE isomers at ratios of ca. 3∶97 and 35∶65, respectively. In the south, one of the eight wild females analyzed was of theZ type and the rest intermediate, whereas males were predominantly trapped with blends of the two isomers containing 60 to 97E. In a laboratory culture reared for one to two generations from corn borers collected in Hungary, three of nine females were of the intermediate type and the restZ. Small amounts of (Z)-11-hexadecenyl acetate were detected in female glands of theE strain; however, no effect of this compound could be observed in the field.

Sex recognition by odour and variation in the uropygial gland secretion in starlings

1. Although a growing body of evidence supports that olfaction based on chemical compounds emitted by birds may play a role in individual recognition, the possible role of chemical cues in sexual selection of birds has been only preliminarily studied. 2. We investigated for the first time whether a passerine bird, the spotless starling Sturnus unicolor, was able to discriminate the sex of conspecifics by using olfactory cues and whether the size and secretion composition of the uropygial gland convey information on sex, age and reproductive status in this species. 3. We performed a blind choice experiment during mating, and we found that starlings were able to discriminate the sex of conspecifics by using chemical cues alone. Both male and female starlings preferred male scents. Furthermore, the analysis of the chemical composition of the uropygial gland secretion by using gas chromatography-mass spectrometry (GC-MS) revealed differences between sexes, ages and reproductive status. 4. In conclusion, our study reveals for first time that a passerine species can discriminate the sex of conspecifics by relying on chemical cues and suggests that the uropygial gland secretion may potentially function as a chemical signal used in mate choice and/or intrasexual competition in this species.

Compost and vermicompost of olive cake to bioremediate triazines-contaminated soil

The use of organic amendments to bioremediate potential organic pollutants of soil and water has become an increasingly relevant issue in the last years. This strategy has been applied to four triazine herbicides in a typical calcareous agricultural soil of the Mediterranean area. The soil was amended with olive cake, compost and vermicompost of olive cake at rates four times higher than the agronomic dose in order to stimulate biodegradation of simazine, terbuthylazine, cyanazine and prometryn, added in a mixture to the soils. Degradation studies were carried out in sterile and microbially active soil to evaluate the effect of the chemical and biological degradation of triazines. The residual herbicide concentrations at the end of the degradation assay showed no significant differences between non amended and amended soil. However, the addition of compost and vermicompost enhanced the biological degradation rate of triazines during the first week of incubation, with half-lives ranging form 5 to 18 days for the amended soils, whilst negligible degradation occurred in non-amended soil during this period. In contrast, olive cake did not significantly modify the degradation of triazines in spite that the addition of this amendment to soil resulted in the highest dehidrogenase activity values. In all the substrates, degradation of cyanazine and prometryn was faster (between 1.5 and two times higher) than those of terbuthylazine and simazine, without significant relationship with sorption parameters. The first order kinetic equation satisfactorily explained the experimental data for all triazines. A biphasic model, such as that proposed by Hoerl, was better to predict the very rapid triazines decay during the first week of incubation in soil amended with compost and vermicompost.

Persistence of two neonicotinoid insecticides in wastewater, and in aqueous solutions of surfactants and dissolved organic matter.

Wastewater treatment plants receive organic contaminants, such as pesticides, which reach the sewage system from domestic, industrial or agricultural activities. In wastewater, which is a complex mixture of organic and inorganic compounds, biotic or abiotic degradation of contaminants can be affected by the presence of co-solutes. The photodecomposition in natural sunlight of two neonicotinoid insecticides, thiamethoxam and thiacloprid, was investigated in wastewater, aqueous extracts of sewage sludge and in aqueous surfactant solutions, which are abundant in wastewater. Dissipation in the dark was also studied in wastewater, due to reduction of transmitted sunlight in wastewater ponds. With regard to photolysis, thiamethoxam degraded rapidly in all the aqueous solutions. Among them sewage sludge extracts slightly modified (average half-life 17.6h), wastewater increased (13.7h) and non-ionic surfactants led, as a family, to the highest dissipation rates (average 6.2h), with respect to control water (18.7h). Additionally this pesticide also underwent a slower biodegradation process in wastewater in the dark under anaerobic conditions (around 25d). A metabolite of thiamethoxam from the biological decomposition in wastewater was identified by HPLC/MS. On the other hand thiacloprid was found to be resistant to photo- and biodecomposition and remained almost unchanged during the experimental periods in all the tested media.

Photodegradation of mecoprop and dichlorprop on dry, moist and amended soil surfaces exposed to sunlight

The effects of environmental conditions on the photodecomposition of two phenoxy-alkanoic acid herbicides were investigated on different soil surfaces conditions under sunlight exposition. A technique has been developed to study this process on moist nonsterile soil surfaces. A slow rate of disappeareance occurs in the three soils exposed to sunlight in absence of water. Photolysis of these herbicides is controlled by soil texture and its adsorption capacity. The organic matter does not have a sensitizing effect on the photodecomposition of these herbicides on dry soil surfaces. On nonsterile moist soil surfaces exposed to sunlight, the photolytic process prevails in the two first days of exposure and the transformation kinetics fits the Hoerl function better than the first-order exponential equation.

Sorption of hydrophobic pesticides on a Mediterranean soil affected by wastewater, dissolved organic matter and salts.

Irrigation with treated wastewaters as an alternative in countries with severe water shortage may influence the sorption of pesticides and their environmental effects, as wastewater contains higher concentrations of suspended and dissolved organic matter and inorganic compounds than freshwater. We have examined the sorption behaviour of three highly hydrophobic pesticides (the herbicide pendimethalin and the insecticides α-cypermethrin and deltamethrin) on a Mediterranean agricultural soil using the batch equilibration method. We considered wastewater, extracts from urban sewage sludge with different dissolved organic carbon contents, and inorganic salt solutions, using Milli Q water as a control. All pesticides were strongly retained by soil although some sorption occurred on the walls of the laboratory containers, especially when wastewater and inorganic salt solutions were used. The calculation of distribution constants by measuring pesticide concentrations in soil and solution indicated that pendimethalin sorption was not affected whereas α-cypermethrin and deltamethrin retention were significantly enhanced (ca. 5 and 2 times, respectively) when wastewater or salt solutions were employed. We therefore conclude that the increased sorption of the two pesticides caused by wastewater cannot be only the result of its dissolved organic carbon content, but also of the simultaneous presence of inorganic salts in the solution.

Influence of the solid-phase extraction process on calibration and performance parameters for the determination of pesticide residues in water by gas chromatography

Abstract Twenty-six organophosphorus, organochlorine and other electron-capture detection-sensitive pesticides were extracted from water in a single step using a C 18 solid-phase extraction cartridge, eluted with ethyl acetate and isooctane and determined by gas chromatography with electron-capture and flame photometric detection. The calibration equation for the extraction method was calculated for a twentyfold concentration range, including the EC limit of 0.1 μg/l. The linearity, precision, sensitivity and detection limit of the method were studied, applying the statistical model of linear regression. A lack of linearity was observed for fenthion, deltamethrin and trifluralin, but the proposed method was suitable for other pesticides studied. The limits of detection range from 20 to 120 ng/l applying the calibration graph and from 1 to 40 ng/l based on a signal-to-noise ratio of 3:1.