Effects of organophosphate compounds on a soil protist, Colpoda inflata (Ciliophora, Colpodidae)

Many investigations on protists indicate that they play an important role in agricultural soils. We have tested the effects of three organophosphate (OP) pesticides, basudin, cidial, and fenix, on the soil ciliate Colpoda inflata, and examined its viability, fission rate, ability to excyst and extrude macronuclear chromatin into cytoplasm. Exposure to these OPs caused a dose-dependent effect on cell viability, and significantly reduced the mean fission rate at a concentration of 1/10(5) v/v. After exposure of resting cysts to 1/10(5) v/v or 1/10(6) v/v concentrations of basudin or cidial, the number of excysted cells was significantly lower than that of the controls. Conversely, exposure to a 1/10(5) v/v fenix concentration did not affect excystment and exposure to 1/10(6) v/v was found to promote excystment. Moreover, exposure to these OPs (1/10(4) v/v or 1/10(5) v/v) interferred with the ability to extrude macronuclear chromatin. The median lethal concentration in 60 min for each OPs tested was at least a hundred times lower than the doses recommended by the manufacturer. Finally, as the inhibition of cholinesterase (ChE) activity is the first target of OPs, the presence of ChE activity was checked in C. inflata. Three ChE activities were found, hydrolyzing the substrates acetyl-beta-methyl thiocholine iodide, propionyl thiocholine iodide and butyryl thiocholine iodide, that appeared to be very low and not inhibited by OP-exposure.     

Cholinesterase activity and effects of its inhibition by neurotoxic drugs in Dictyostelium discoideum

Recently, we found acetylcholinesterase (AChE) activity in the ciliate protozoan Paramecium primaurelia. As in the slime mould Dictyostelium discoideum the presence of a serine esterase was found with strong sequence identity to Torpedo AChE, we extended to D. discoideum the investigation on the characterization and possible functions of cholinesterases (ChEs). In amoeboid cells, histochemical, biochemical, and electrophoresis analyses evidenced both a ChE activity able to hydrolyze the substrate PrTChI, and AChE (E.C. 3.1.1.7.) activity similar to Electrophorus electricus AChE. Conversely, butyrylcholinesterase activity was nearly absent, according to our previous results on P. primaurelia. Moreover, the possibility to utilize D. discoideum in a bioassay for the pre-chemical screening both of moist environments and fresh waters, in relation to the occurrence of the neurotoxic organophosphate drugs, such as "basudin", inhibiting ChE activity, was investigated. Exposure to basudin inhibited propionylcholinesterase (PrChE) activity in a dose-dependent manner in the range 10(-1)-10(-7) M (60% at 10(-4) M), without any significant effect on AChE activity. PrChE activity was inhibited slightly by 10(-5) M eserine, and reduced significantly both by 10(-5) M iso-OMPA and BW284C51, classically used to discriminate the different ChE molecular forms. The effects on cell morphology, cell density, and differentiation were evaluated in cultures exposed to PrTChI 10(-5) M or basudin 10(-4) M for a three-day period. The PrTChI-exposed sample exhibited cell morphology, cell density, ability to aggregate, and to form fruiting bodies similar to the control; whereas, the basudin-exposed sample showed anomalies in cell morphology and lower cell density than the control, together with inability to aggregate.     

Acid soluble bio-organic substances isolated from urban bio-waste. Chemical composition and properties of products

As previous work proposed commercial expectations for soluble bio-organic substances (SBO) isolated from compost of urban food, gardening and park trimming residues as chemical auxiliaries, nine urban bio-wastes (BW) treated by aerobic and anaerobic digestion for 0-360 days were used to extract SBO and investigate source variability effects on product chemical composition and properties. The bio-wastes were collected over a 13732 km² area populated by 2.9 millions from 565 municipalities. The SBO were characterized by their content of different C types and functional groups and by their distribution coefficient (K_PEGW) between polyethylene glycol and water. A significant linear correlation was found between K_PEGW and the lipophilic/hydrophilic C ratio. The investigated SBO exhibited up to sixfold change of K_PEGW demonstrating that BW available from densely populated urban areas are an interesting exploitable source of a wide variety of potential products for the chemical market.     

The Food Allergy Risk Management in the EU Labelling Legislation

Food allergy represents an increasing public health issue, and a large number of food control authorities have provided regulations aimed to minimize the risk of allergic reaction for sensitized consumers. The Food and Agriculture Organization of the United Nations together with the World Health Organization established the Codex Alimentarius Commission whose main goal is to protect the consumers’ health. To purse this task the Commission listed the foods and ingredients causing the most severe allergic reactions that should be labelled. It has been reported that some cases of specific foods hypersensitivity display a different prevalence among different Countries. Thus, the European Union drew up a list of mandatory allergens (that must be labelled) longer than that provided by Codex Alimentarius. As a consequence of the complexity of the legal phraseology of the European Union (EU) and/or European Community (EC) the Regulations and/or Directives were differently translated in all EC/EU official languages determining possible misinterpretations of the legislation. Moreover, food labelling regulations were also established with the goal to promote the consumers’ conscious choice about what they eat. Starting from the case of the fermented beverages, we analysed the European legislative scenario concerning the allergen labelling of the last fifteen years, highlighting that mistranslations, misinterpretations and lack of information in the EU Regulations might lead to health and ethical issues.     

Bayesian Ecological Regression with Latent Factors: Atmospheric Pollutants Emissions and Mortality for Lung Cancer

In this work we propose a Bayesian ecological analysis in which a latent variable summarizes data on emissions of atmospheric pollutants. We specified a hierarchical Bayesian model with spatially structured and unstructured random terms with a nested latent factor model. This can be considered a combination of the convolution spatial model of Besag et al. (1991) and an ecological regression analysis in which a latent variable plays the role of the covariate. The unified approach allows to proper account for the uncertainty in the latent score estimation in the regression analysis. The Bayesian Latent Factor model is used to summarize the information on environmental pressure derived from three stressors: Carbon Monoxide, Nitrogen Oxides and Inhalable Particles. We found evidence of positive correlation between Lung cancer mortality and environmental pressure indicators, in males, Tuscany (Italy), 1995–1999. Environmental pressure seems to be restricted to fourteen municipalities (top 5% of the Latent Factor distribution). The model identified two areas with high point source emissions.     

Yessotoxin determination in Mytilus galloprovincialis revealed by an in vitro functional assay

Yessotoxins (YTXs) are polycyclic ether compounds produced by phytoplanktonic dinoflagellates and accumulated in filter-feeding shellfish. Mouse bioassay is still the official method to detect these toxins, even if it is lacking of specificity and sensitivity. Moreover, there is growing resistance against the use of animal experiments. Many efforts have been made to determine YTXs with other methods. The detection of YTX using a functional assay allows its quantification with an automated and repetitive technique at concentrations in the range of the 1 mg of YTX equivalent/kg European regulatory limit. In this study, an in vitro functional assay based on YTX treatment of MCF-7 cells and resulting in the accumulation of a 100-kDa fragment of E-cadherin was developed on samples of Mytilus galloprovincialis collected from the Adriatic Sea, Italy, along the coasts of Abruzzo, Molise, and Emilia Romagna regions. The YTX concentrations ranged from 0.2 to 1.8 mg of YTX equivalent/kg. The occurrence of levels exceeding the above mentioned limit was observed only in samples of Emilia Romagna region. This last result could represent a risk for human health, but these shellfish were not intended to consumers, because they belonged to a preventive monitoring program.