Hexachlorocyclohexane chemical remediation of a contaminated site in Argentina.

This work describes the complete decontamination of three parcels of a dump site located in Lomas de Zamora county, Buenos Aires province (Argentina) heavily polluted with hexachorocyclohexane (HCH), where phytoremediation, successful in the surrounding areas, was ineffective. HCH contained in contaminated soil (10 g/kg average) was oxidized with sodium persulfate activated with citric acid chelated Fe(II). This chemical remediation process required treatment in situ in each parcel of approximately 10900 tons total of soil that were mechanically removed and initially mixed with 1750 tons of sodium persulfate. The mixture was then transferred to the excavation site, and 105 tons of ferrous sulfate and 35 tons of citric acid were finally added. The process, started in January 2011 and completed in February 2016, was very effective since chemical remediation average efficiency in the three parcels was higher than 99.99%. To the best of our knowledge this work is the first demonstration that persulfate oxidation activated with citric acid chelated Fe(II) can be successfully applied for field remediation of a relatively large area.

Hexachlorocyclohexane phytoremediation using Eucalyptus dunnii of a contaminated site in Argentina.

In 1996, a diagnostic study performed in a 16-ha field located in Buenos Aires Province (Argentina), where a chemical industry produced 1,2,3,4,5,6-hexachlorocyclohexane (HCH) from 1960 to 1978, showed contamination with HCH ranging from 10 to 20,000 mg kg-1 dry soil (706.4 mg kg-1 average). For remediation purposes, a forestation plan was put into practice in 1997 employing approximately 12,300 Eucalyptus dunnii seedlings which by 2016 where fully grown into trees that formed a forest where local fauna can be found. Midterm analysis done in 2005, when E. dunnii trees had developed into 8-10 m high trees, indicated that HCH was incorporated into leaves and logs and soil phytoremediation was progressing. Final quantitation analysis of HCH in soil performed in 2016 demonstrated that the 97.2% of the field area was effectively decontaminated with 98.1% overall average efficiency. Thus, this work is the first global example of a successful employment of E. dunnii trees for HCH phytoremediation purposes at field scale. These results may encourage other researchers to test the ability of E. dunnii to phytoremediate soils contaminated with other chlorinated compounds like polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs).

Bioremediation of hydrocarbon-contaminated soils in cold regions: Development of a pre-optimized biostimulation biopile-scale field assay in Antarctica.

Bioremediation proved to be an effective approach to deal with soil contamination, especially in isolated, cold environments such as Antarctica. Biostimulation, involving the addition of macronutrients -mainly nitrogen and phosphorous- is considered the simplest and cheapest bioremediation process. Optimizing the levels of these nutrients is a key step prior to the application of a biostimulation strategy. In this work, N and P levels, optimized by Response Surface Methodology (RSM) at lab-scale, were applied to an Antarctic hydrocarbon contaminated soil. The process was performed on-site, using high density polyethylene geomembranes (800µm) to isolate treated soil from the surroundings and under environmental conditions at Carlini station (Antarctica) during 50days. Two 0.5ton biopiles were used as experimental units; a control biopile (CC), and a biostimulated system (BS), amended with N and P. At the end of the assay, hydrocarbon removal was significantly higher in BS system compared to CC (75.79% and 49.54% respectively), showing that the applied strategy was effective enough to perform a field-assay in Antarctica that significantly reduce soil contamination levels; and proving that RSM represents a fundamental tool for the optimization of nutrient levels to apply during bioremediation of fuel contaminated cold soils.

Multilevel processes and cultural adaptation: Examples from past and present small-scale societies.

Cultural adaptation has become central in the context of accelerated global change with authors increasingly acknowledging the importance of understanding multilevel processes that operate as adaptation takes place. We explore the importance of multilevel processes in explaining cultural adaptation by describing how processes leading to cultural (mis)adaptation are linked through a complex nested hierarchy, where the lower levels combine into new units with new organizations, functions, and emergent properties or collective behaviours. After a brief review of the concept of "cultural adaptation" from the perspective of cultural evolutionary theory and resilience theory, the core of the paper is constructed around the exploration of multilevel processes occurring at the temporal, spatial, social and political scales. We do so by examining small-scale societies' case studies. In each section, we discuss the importance of the selected scale for understanding cultural adaptation and then present an example that illustrates how multilevel processes in the selected scale help explain observed patterns in the cultural adaptive process. We end the paper discussing the potential of modelling and computer simulation for studying multilevel processes in cultural adaptation.

Hepatic tyrosine aminotransferase and glucocorticoid abuse in meat cattle.

Besides being extensively applied as therapeutical remedies, glucocorticoids (GCs) - most notably dexamethasone or prednisolone - are also illegally used in livestock for growth-promoting purposes. This study was designed to assess the suitability of liver tyrosine aminotransferase (TAT), a gluconeogenic enzyme known to be induced by GCs, to act as a reliable candidate biomarker to screen for GC abuse in cattle. Enzyme activity was measured spectrophotometrically in liver cytosols or in cell extracts, and TAT gene expression was determined by real-time PCR. Compared with untreated veal calves, a notable scatter (20-fold) and much higher median values (3-fold) characterized TAT specific activity in liver samples from commercially farmed veal calves. A time-related increase in both enzyme activity and gene expression was detected in rat hepatoma cell lines treated with dexamethasone concentrations (10(-8) or 10(-9) m) in the range of those recorded in noncompliant samples from EU official controls. In experimental studies in which finishing bulls were administered GCs at growth-promoting dosages, however, no such changes were recorded in dexamethasone-treated animals; a statistically significant rise in liver TAT activity (+95%) only occurred in prednisolone-treated bulls. Although further research is needed to characterize the GC-mediated response in cattle liver, TAT does not appear to be a specific and sensitive biomarker of GC abuse in the bovine species.

Contact dermatitis caused by dimethylfumarate in Argentina.

For the first time in Argentina, we describe an outbreak of contact dermatitis. New pairs of shoes caused intense pruritus, pain, and eruption, followed by edema, blisters, and a severe negative impact on the epidermal barrier of the feet. We identify dimethylfumarate as the causal agent and suggest an analytical method for its fast identification.

Novel strategies for tracing the exposure of meat cattle to illegal growth-promoters.

Official monitoring of residues in cattle throughout the European Union in 2007 found <0.2% non-compliance for the use of illegal growth-promoters (GPs), including sex steroids, corticosteroids and ß-agonists. There is evidence, however, that these figures may underestimate the real incidence of GP abuse in meat cattle breeding. One source of evidence arises from the introduction of new detection strategies in response to the demand for safe and wholesome food. These strategies are based on the biological effects of the different GP classes in target species, with a focus on identifying reliable and cost effective biomarkers to improve detection methods. This review summarises the published data relating to experimental and field studies performed in meat cattle, emphasising the impact of the 'omic' technologies and bioinformatics to discover suitable biomarkers for residue surveillance. Further research is required before any potential biomarkers can be utilised for large scale high throughput screening tests.

Influence of nutrients addition and bioaugmentation on the hydrocarbon biodegradation of a chronically contaminated Antarctic soil.

Complexity involved in the transport of soils and the restrictive legislation for the area makes on-site bioremediation the strategy of choice to reduce hydrocarbons contamination in Antarctica. The effect of biostimulation (with N and P) and bioaugmentation (with two bacterial consortia and a mix of bacterial strains) was analysed by using microcosms set up on metal trays containing 2.5 kg of contaminated soil from Marambio Station. At the end of the assay (45 days), all biostimulated systems showed significant increases in total heterotrophic aerobic and hydrocarbon-degrading bacterial counts. However, no differences were detected between bioaugmented and nonbioaugmented systems, except for J13 system which seemed to exert a negative effect on the natural bacterial flora. Hydrocarbons removal efficiencies agreed with changes in bacterial counts reaching 86 and 81% in M10 (bioaugmented) and CC (biostimulated only) systems. Results confirmed the feasibility of the application of bioremediation strategies to reduce hydrocarbon contamination in Antarctic soils and showed that, when soils are chronically contaminated, biostimulation is the best option. Bioaugmentation with hydrocarbon-degrading bacteria at numbers comparable to the total heterotrophic aerobic counts showed by the natural microflora did not improve the process and showed that they would turn the procedure unnecessarily more complex.

Bacterial community dynamics during bioremediation of diesel oil-contaminated Antarctic soil.

The effect of nutrient and inocula amendment in a bioremediation field trial using a nutrient-poor Antarctic soil chronically contaminated with hydrocarbons was tested. The analysis of the effects that the treatments caused in bacterial numbers and hydrocarbon removal was combined with the elucidation of the changes occurring on the bacterial community, by 16S rDNA-based terminal restriction fragment length polymorphism (T-RFLP) typing, and the detection of some of the genes involved in the catabolism of hydrocarbons. All treatments caused a significant increase in the number of bacteria able to grow on hydrocarbons and a significant decrease in the soil hydrocarbon content, as compared to the control. However, there were no significant differences between treatments. Comparison of the soil T-RFLP profiles indicated that there were changes in the structure and composition of bacterial communities during the bioremediation trial, although the communities in treated plots were highly similar irrespective of the treatment applied, and they had a similar temporal dynamics. These results showed that nutrient addition was the main factor contributing to the outcome of the bioremediation experiment. This was supported by the lack of evidence of the establishment of inoculated consortia in soils, since their characteristic electrophoretic peaks were only detectable in soil profiles at the beginning of the experiment. Genetic potential for naphthalene degradation, evidenced by detection of nahAc gene, was observed in all soil plots including the control. In treated plots, an increase in the detection of catechol degradation genes (nahH and catA) and in a key gene of denitrification (nosZ) was observed as well. These results indicate that treatments favored the degradation of aromatic hydrocarbons and probably stimulated denitrification, at least transiently. This mesocosm study shows that recovery of chronically contaminated Antarctic soils can be successfully accelerated using biostimulation with nutrients, and that this causes a change in the indigenous bacterial communities and in the genetic potential for hydrocarbon degradation.

Thyroid autoimmunity and infertility.

We aimed to study the prevalence of thyroid autoimmunity in infertile women; to assess whether thyroid autoantibodies were associated with non-organ-specific autoantibodies; and to investigate the influence of this dysfunction on the couples' chances of pregnancy. We assayed serum levels of thyroid stimulating hormone (TSH), free thyroxine, and microsomal and thyroglobulin autoantibodies in 149 infertile women. In patients with serum TSH levels in the hypothyroid or hyperthyroid range and/or with thyroid autoantibodies, we performed thyroid ultrasound examinations and assayed some non-organ-specific autoantibodies. We compared the duration of infertility in infertile patients with normal thyroid (control group), with thyroid abnormalities, and with thyroid autoantibodies in euthyroidism. Thirty infertile patients (20.1%) had thyroid abnormalities. The prevalence of thyroid autoantibodies was 17.4%. In infertile patients with thyroid autoantibodies, we found a poor association with non-organ-specific autoantibodies. Only the women with thyroid abnormalities and ovulatory dysfunction had a mean duration of infertility significantly longer than that of the control group. When the data were analyzed for euthyroid women with thyroid autoantibodies, we found no significant variation in the duration of infertility. Although we found a high prevalence of thyroid autoantibodies in infertile patients, the presence of these autoantibodies per se did not reduce the chance of pregnancy.

Measurement of myo-inositol turnover in phosphatidylinositol: description of a model and mass spectrometric method for cultured cortical neurons.

Rates of myo-inositol (Ins) incorporation and turnover in phosphatidylinositol (PtdIns) were determined in cultured mouse cortical neurons. Cells were incubated with deuterium-labeled myo-inositol (Ins) in culture medium free of unlabeled Ins. The time-dependent changes in the specific activity of cytosolic Ins and membrane PtdIns were measured by mass spectrometry. PtdIns turnover was modeled incorporating values for Ins flux, cytosolic dilution, PtdIns concentration, and rate of incorporation into PtdIns. Recycled Ins diluted the labeled precursor pool, and a time course was obtained for this cytosolic process. The specific activity of the precursor pool at the plateau of the time-course curve was 0.43 +/- 0.04 (mean +/- SD). The incorporation of the tracer into PtdIns was linear between 4 and 10 h incubation of the neurons. After factoring in the extent of dilution of the tracer in the precursor pool, the rate of Ins incorporation into PtdIns was found to be 315 +/- 51 nmol (g of protein)(-1) x h(-1). The half-life of Ins in PtdIns was calculated for each point on the linear incorporation curve and then corrected for the tracer reincorporation. The half-life of Ins in PtdIns was 6.7 +/- 0.2 h, which translates into a basal turnover rate of 10.3%/h in this in vitro system. The mathematical model and the stable isotope method described here should allow assessment of the dynamics of PtdIns signaling altered in certain diseases or by agents.

Studies on inhibition of human platelet function by sodium nitroprusside. Kinetic evaluation of the effect on aggregation and cyclic nucleotide content.

In this study, we explored the ability of sodium nitroprusside to inhibit the aggregation of human platelets in platelet-rich plasma (PRP) and whole blood and its effects on intracellular levels of guanosine 3',5'-cyclic monophosphate (cGMP) and adenosine 3',5'-cyclic monophosphate (cAMP). The experiments investigated dose-dependent effects of nitroprusside starting from concentrations in the range of circulating levels achievable in vivo during drug administration in humans. Furthermore, we investigated the time-course of both antiaggregating action and the influence on cyclic nucleotide synthesis. Results showed that sodium nitroprusside inhibited the aggregation induced by adenosine 5-diphosphate (ADP) and collagen starting from concentration as low as 2 micromol/l. The IC(50) value for ADP-induced aggregation in PRP was 18.7+/-2.4 micromol/l. The inhibition of platelet aggregation showed a time-dependent behaviour and was not reversible within 90 min. The accumulation of intraplatelet cGMP in the presence of sodium nitroprusside exhibited a comparable time-course characterized by an early increase, a steady state and a late further increase. The time-course of cAMP synthesis was very similar to that of cGMP. Our data evidenced a long-lasting inhibition of platelet responses by sodium nitroprusside and excluded a desensitization of platelet guanylyl cyclase after 3-h exposure to nitric oxide (NO). Furthermore, they indicated a role of cAMP accumulation in the antiaggregating effects of nitroso donor: the simultaneous increase of intracellular content of cAMP and cGMP can synergize in the reduction of the platelet responses.

Determination of bisphenol A in food-simulating liquids using LCED with a chemically modified electrode.

Liquid chromatography with electrochemical detector (LC-ED), using a chemically modified electrode coated with a metalloporphyrin film, is reported for determination of bisphenol A (BPA) migration from polycarbonate baby bottles. The extraction process of the samples was performed according to regulations of the Southern Common Market (MERCOSUR), where certain food-simulating liquids [(A) distilled water, (B) acetic acid 3% V/V in distilled water, and (C) ethanol 15% V/V in distilled water] are defined along with controlled time and temperature conditions. The baseline obtained using the naked electrode showed a considerable drift which increased the detection limit. This effect was suppressed with the chemically modified electrode. A linear range up to 450 ppb along with a detection limit of 20 ppb for the amperometric detection technique was observed. The procedure described herein allowed lowering the detection limit of the method to 0.2 ppb. The value found for BPA in the food-simulating liquid is 1.2 ppb, which is below the tolerance limit for specific migration (4.8 ppm).

Cell-cell signaling and adhesion in phagocytosis and early development of Dictyostelium.

Cell-cell signaling and adhesion regulate transition from the unicellular to the multicellular stage of development in the cellular slime mold Dictyostelium. Essential gene networks involved in these processes have been identified and their interplay dissected. Heterotrimeric G protein-linked signal transduction plays a key role in regulating expression of genes mediating chemotaxis or cell adhesion, as well as coordinating actin-based cell motility during phagocytosis and chemotaxis. Two classes of cell adhesion molecules, one cadherin-like and the second belonging to the IgG superfamily, contribute to the strength of adhesion in Dictyostelium aggregates. The developmental role of genes involved in motility and adhesion, and their degree of redundancy, have been re-assessed by using novel developmental assay conditions which are closer to development in nature.

Brain myo-inositol level is elevated in Ts65Dn mouse and reduced after lithium treatment.

The segmental trisomy Ts65Dn mouse is a novel model of Down syndrome (DS). The purpose of this study was to measure brain levels of myo-inositol (ml), N-acetylaspartate (NAA), and other metabolites in Ts65Dn mice using in vivo 1H magnetic resonance spectroscopy (MRS), and to determine whether lithium (Li) treatment alters brain ml level. The ratio of ml over total creatine (Cr), ml/Cr, was significantly elevated (mean change +38%), while NAA/Cr was significantly decreased (mean change -18%) in Ts65Dn mice (n=5) compared with control mice (n= 7). This is consistent with 1H MRS findings in DS human adults. Brain ml/Cr of the entire sample group (n= 12) was reduced (mean change -15%) following Li treatment, supporting the Li-induced ml depletion hypothesis.

Increased synaptic depression in the Ts65Dn mouse, a model for mental retardation in Down syndrome.

Long-term potentiation (LTP) and depression (LTD) were investigated in hippocampus of a genetic model of Down syndrome, the segmental trisomy (Ts65Dn) mouse. Field excitatory postsynaptic potentials were recorded from hippocampal slices and LTP and LTD evoked sequentially. LTP decreased whereas LTD increased significantly in Ts65Dn compared with control hippocampus.

The ultrastructural effects of beta-amyloid peptide on cultured PC12 cells: changes in cytoplasmic and intramembranous features.

The fine structural features of cultured PC12 cells were investigated after treatment for 1, 3, or 5 days with different concentrations of the vascular form of beta-amyloid 1-40 (beta-AP). PC12 cells treated with beta-AP showed time- and concentration-dependent lysosomal system activation and cell toxicity. We observed increases in the number and size of cytoplasmic lysosomes as indicated by increased acid phosphatase reactivity. Some lysosomes were in the form of multivesicular bodies or large residual bodies that appeared to arise by autophagia or by endocytotic uptake. Double-sided plasma membrane invaginations were observed to give rise to increasingly extensive intracytoplasmic vacuolization that was correlated with duration of beta-AP treatment. Freeze-fracture studies of the intramembranous particle (IMP) population in the plasma membrane P-face showed that both control and beta-AP treated cells had two major P-face IMP populations, small-diameter (4-8 nm) IMPs, and large-diameter (> or = 9 nm) IMPs. The larger category of IMPs was found to possess a greater average diameter in the beta-AP treated cells than in the control cells. These IMPs could represent modifications to existing transmembranous receptors, channels, or transducing molecules by the beta-AP. These results demonstrate that beta-AP can induce time- and concentration-dependent ultrastructural changes in PC12 cell membranes.

Bronchial and bronchoalveolar inflammation in single early and dual responders after allergen inhalation challenge.

To characterize the cellular inflammation at the bronchial and bronchoalveolar levels, we evaluated 43 patients with asthma who were sensitized to house dust mites. On 2 consecutive days patients underwent methacholine challenge and allergen bronchial challenge. In addition, 6, 24, or 72 h after allergen challenge, fiberoptic bronchoscopy with bronchial lavage (BL) and bronchoalveolar lavage (BAL) was performed. Patients belonging to the 6-h, 24-h, or 72-h group were divided further into two subgroups: those with isolated early response to allergen (LAR-), and those with dual response to allergen (LAR+). The percentage of eosinophils and of epithelial cells in BAL fluid was significantly higher in LAR+ than in LAR- patients in the 6-h group (p < 0.05, each comparison), but not 24 or 72 h after (p > 0.05, each comparison). Similarly, the proportion of BL eosinophils was also higher in LAR+ than in LAR- patients, both in the 6-h and in the 24-h group (p < 0.05, each comparison). In addition, increased proportions of BL neutrophils were present in the LAR+ patients belonging to the 24-h group (p < 0.05). Comparing "proximal" = BL vs "distal" = BAL data, we found a significantly higher proportion of epithelial cells in BL compared with BAL, in both LAR- and LAR+ subjects, either 6, or 24, or 72 h after challenge (p < 0.01, each comparison) and increased percentages of BL neutrophils and eosinophils in LAR+ patients (p < 0.05, each comparison), but not in LAR- patients, in the 24-h group. The percentages of BL or BAL macrophages and lymphocytes did not differ significantly among the different patient groups. These data indicate that the development of LAR after allergen inhalation challenge is associated with an early recruitment of eosinophils and with epithelial desquamation in the airways. In addition, after allergen challenge epithelial desquamation is more pronounced in the proximal than in the distal airways, independently of the type of bronchial response.

BAL neutrophilia in asthmatic patients. A by-product of eosinophil recruitment?

Although neutrophil number may be increased in the airways of patients with asthma, its pathogenetic role in this disorder remains unclear. We evaluated BAL of 8 normal control subjects, 30 +/- 2 years of age, and 24 patients with mild asthma: 17 patients with allergic asthma, 24 +/- 1 years of age, and 7 patients with nonallergic asthma, 30 +/- 1 years of age. The BAL of asthmatic patients showed increased numbers of neutrophils (p < 0.01), eosinophils (p < 0.01), and ciliated epithelial cells (p < 0.05) and increased concentrations of myeloperoxidase (MPO) (p < 0.01) compared with control subjects. Positive correlations were observed between the number of BAL neutrophils and eosinophils (Rs = 0.780, p < 0.0001) and between BAL neutrophil numbers and BAL MPO levels (Rs = 0.40, p < 0.05). No correlations were found between the following: (1) BAL eosinophils or neutrophils and BAL epithelial cells (p > 0.05, each comparison); (2) BAL neutrophils or eosinophils and log Pd15 methacholine (MCh) (p > 0.05, each comparison); or (3) BAL epithelial cells or log Pd15 MCh and BAL MPO (p > 0.05, each comparison). Dividing the patient population into two groups, allergic asthmatics and nonallergic asthmatics, similar BAL neutrophil, eosinophil, and epithelial cell numbers and similar MPO levels were found (p > 0.05, each comparison). In addition, the correlations between BAL neutrophils and eosinophils showed similar significance in the two patient subgroups (p > 0.05, each comparison). These results suggest that, both in allergic and nonallergic asthma, airway recruitment and activation of neutrophils occur as does parallel eosinophil migration. However, airway neutrophils do not seem to contribute significantly to epithelial cell injury or to airway hyperresponsiveness in the steady state.