Enhanced Dechlorination of Carbon Tetrachloride by Immobilized Fulvic Acids on Alumina Particles

Fulvic acids (FA) were immobilized on alumina particles in order to evaluate their catalytic effect as solid-phase redox mediator (RM) during the reductive dechlorination of carbon tetrachloride (CT) by anaerobic sludge. FA were extracted from three different soil samples and two commercial composts. Electron carrying capacity (ECC) was determined in all FA samples in order to select the appropriate source of redox-mediating compounds for CT dechlorination. TiO₂, Al(OH)₃, and γ-Al₂O₃ particles were tested as immobilizing materials for the extracted FA. FA extracted from a temperate pine forest soil showed the highest ECC (291.72 μmol g⁻¹). The highest adsorption capacity of FA, measured as total organic carbon (TOC), was achieved by alumina (γ-Al₂O₃) particles (12 mg TOC-FA g⁻¹). Results suggest that the transfer of electrons rather than their microbial generation through glucose fermentation was the rate-limiting factor during dechlorination of CT. Immobilized FA increase up to 10.4-fold the rate of CT dechlorination as compared with the control lacking FA. Immobilization of FA on alumina particles was very stable, and spectrophotometric screening did not detect any detachment of FA during dechlorination of CT, thus confirming that the enhanced dechlorination achieved could exclusively be linked to the redox-mediating capacity of immobilized FA. The present study constitutes the first demonstration that immobilized FA on alumina particles could serve as a solid-phase RM in dechlorination reactions.     

Phytochemical Profile,Antioxidant and Cytotoxic Activities of the Carob Tree (<Emphasis Type="Italic">Ceratonia siliqua</Emphasis> L.) Germ Flour Extracts

This work aimed to evaluate the phytochemical content and to determine the antioxidant and cytotoxic activities of methanol extracts of the carob tree (Ceratonia siliqua L.) germ flour. The extracts were rich in phenolic compounds, had considerable antioxidant activity, and reduced the viability of cervical (HeLa) cancer cells. The chemical content and the biological activities of the extracts were significantly affected by gender and cultivar. Female cultivar Galhosa had the highest levels of phenolic compounds, and the highest antioxidant activity. Extracts from the hermaphrodite trees and from the female cultivars Galhosa and Costela/Canela exhibited the highest cytotoxic activity. The most abundant compound was theophylline. The phenolic content was correlated to both antioxidant and cytotoxic activities. Our findings provide new knowledge about the health implications of consuming food supplemented with carob germ flour.     

Involvement of breast cancer resistance protein (BCRP/ABCG2) in the secretion of danofloxacin into milk: interaction with ivermectin

Danofloxacin, a veterinary fluoroquinolone antimicrobial drug, is actively secreted into milk by an as yet unknown mechanism. One of the main determinants of active drug secretion into milk is the transporter (BCRP/ABCG2). The main purpose was to determine whether danofloxacin is an in vitro substrate for Bcrp1/BCRP and to assess its involvement in danofloxacin secretion into milk. In addition, the role of potential drug-drug interactions in this process was assessed using ivermectin. Danofloxacin was transported in vitro by Bcrp1/BCRP, and ivermectin efficiently blocked this transport. Experiments with Bcrp1(-/-) mice showed no evidence of the involvement of Bcrp1 in plasma pharmacokinetics of danofloxacin. However, the milk concentration and milk-to-plasma ratio of danofloxacin were almost twofold higher in wild-type compared with Bcrp1(-/-) mice. The in vivo interaction with ivermectin was studied in sheep after co-administration of danofloxacin (1.25 mg/kg, i.m.) and ivermectin (0.2 mg/kg, s.c.). Ivermectin had no significant effect on the plasma levels of danofloxacin but significantly decreased danofloxacin concentrations in milk by almost 40%. Concomitant administration of multiple drugs, often used in veterinary therapy, may not only affect their pharmacological activity but also their secretion into milk, because of potential drug-drug interactions mediated by BCRP.     

Analysis of the spatial variation of Bovine tuberculosis disease risk in Spain (2006-2009)

In this study we explored the spatial variation of Bovine tuberculosis (BTB) risk of being positive, new positive or persistently positive, as well as the risk of eliminating BTB in positive herds throughout Spain from 2006 to 2009 by means of hierarchical Bayesian models. The results of the models showed that the risk of infection (positive or new positive herds), persistence and elimination was lower in counties located in north and north-eastern of Spain, and in the Balearic and Canary islands than in the rest of the country. In some counties the risk of positivity was high during the four years of study, whereas there were others where the risk of positivity was high only in some of the years. With regard to the risk of persistence of BTB positive herds, counties located in the central, western and south-western part of the country had a higher risk in the three studied periods. This study has identified some specific areas of increased BTB risk in Spain, information that is useful for disease management.     

Arsenic Mining Waste in the Catchment Area of the Madrid Detrital Aquifer (Spain)

In recent years, elevated arsenic concentrations in groundwater used for drinking water supplies have been recognised in the Madrid Tertiary detrital aquifer. Although only natural causes have been suggested as the source of arsenic, this study aims to highlight that the anthropogenic contribution cannot be disregarded. During the sub-catchment??s areas sampling, we found many geographical sites where natural arsenopyrite [FeAsS] originally encapsulated in pegmatite bodies and quartz veins, was artificially outcropped and dumped out, since mining wastes were scattered and exposed to weathering. Several mineral and ground specimens were collected to analyse its mineralogical and chemical composition by X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF) spectrometry and by Environmental Scanning Electron Microscope (ESEM). Both, the abundant existence of secondary phases, such as scorodite [FeAsO₄?2H₂O] and jarosite [KFe₃(SO₄)₂(OH)₆], much more soluble than arsenopyrite, and the lixiviation experiments of arsenopyrite in acidic media to simulate acid mine drainage (AMD) conditions, usually found in old mining districts, point to a potential risk of arsenic contamination of surface water bodies, which operate as recharged waters of the aquifer in the studied area. The elemental determination of heavy metals present in ground samples by XRF analyses, reaching up to 1,173 mg kg^?C1 of copper, 347 mg kg^?C1 of lead and 113,702 mg kg^?C1 of arsenic; and the physicochemical and arsenic fractionation studies of soil samples, led us to classify the soil as Spolic Technosol (Toxic). The contamination of the area due to old mining activities could release arsenic to Madrid water supplies; accordingly, additional decontamination studies should be performed.     

Mucus characterisation in the Octopus vulgaris skin throughout its life cycle

The development of the epidermis of octopus, Octopus vulgaris, throughout its life cycle was studied by conventional staining and histochemical techniques using lectins. The mantle, the arm and the two parts of the suckers: the infundibulum and the acetabulum were analysed independently. With the exception of the suckers, the general morphology of the epidermis does not vary from the first days post-hatching to adulthood. In general terms, histochemical techniques do not indicate changes in the composition of glycoconjugates of the epidermis main cells, epithelial and secretory cells. The epithelial cells of the mantle and arm show positivity for mannose (ConA+) in their apical portions, indicating the presence of n-glycoproteins that, among other things, provide lubrication to the surface of the body. In the suckers, the apical surface of the infundibulum contains sulphated glycosaminoglycans of the N-acetylglucosamine type that provide adhesive properties. In addition to observing three types of mucocytes, m1 and m2 are characteristic of the mantle and arm, and m3 is found in the suckers. The paralarva epidermis is characterised by the presence of Kölliker's organs whose exact function is unknown. In this study, the absence of staining with alcian blue/periodic acid–Schiff(AB/PAS) prevents the possibility of attributing a secretory function. Nevertheless, the linkage of three lectins (WGA, LEL and GSL-I) in the fascicle of the organ suggests the presence of proteoglycans rich in N-acetylglucosamine that would mainly have a structural role.     

Phenylalanine ammonia‐lyase activity and ortho‐diphenolic content with regard to boron nutrition in sunflower leaves.

Homogenates were prepared from the leaves of hydroponically cultivated sunflower (Helianthus annuus, L.) under deficient, normal and toxic B conditions and the phenylalanine ammonia‐lyase activity together with the ortho‐diphenolic and micronutrient content were measured every week from one month to flowering

The restoration of enzymatic activity on the exogenous addition of borate “in vivo”; was also studied.

Both B toxicity and deficiency resulted in increased phenylalanine ammonia‐lyase activity in the homogenates

The toxicity effect was early and sustained and the deficiency effect late and transitory. “In vitro”; borate addition to the reaction mixture did not significantly change the phenylalanine‐ammonia‐lyase activity in the homogenates.

There was no statistical correlation between the phenylalanine‐ammonia‐lyase activity and any micronutrient content in leaves.

A high accumulation of ortho‐diphenolics appeared in B‐deficient leaves only after 28 days of differential culture and may be responsible for the drop in phenylalanine‐ammonia‐lyase activity noted at this time.     

Polyphenol oxidase activity and ortho‐diphenolic content in sunflower leaves in relation to boron nutrition.

Homogenates were prepared from the leaves of hydroponically cultivated sunflowers (Helianthus annuus, L.) under deficient, normal and toxic B conditions and the polyphenol oxidase activity together with the ortho‐diphenolic and micronutrient content was measured every week from one month to flowering.

B deficiency slightly depressed polyphenol oxidase activity and B toxicity decreased it significantly at all times, the response fitting a line versus the logarithm of the B concentration in solution. We found a positive correlation between polyphenol oxidase activity and the B content in leaves.

B action on enzymatic activity seemed not to be caused by direct interaction with substrates as the infiltration of B into deficient leaves did not restore the normal activity

According to our results we suggest that polyphenol oxidase activity may be a valid functional parameter to indicate the nutritional status of B in sunflower plants, if its specificity for B can be demonstrated.

The ortho‐diphenolic content did not change with the B levels used in our experiments. Neither did we find any correlation between enzymatic activity and the o‐diphenolic content of the leaves.     

Activity of nitrate reductase and the content of proteins in Nicotiana rustica grown with various levels of molybdenum

The effect that different levels of molybdenum (11 μMand 111 μM) exert on nitrate reductase (E.C. 1.6.6.1–3) activity (NRA), and the content of total proteins in Nicotiana rustica was studied. Eleven μM and 111 μM of molybdenum increased the activity of nitrate reductase during the growth cycle of N. rustica. Likewise, total protein content (mg/g DW) was increased during the vegetative growth of the plants.