A mathematical model for the evaluation of iron transport across the blood-cerebrospinal fluid barrier in neurodegenerative diseases

Iron plays important roles in healthy brain but altered homeostasis and concentration have been correlated to aging and neurodegenerative diseases. Iron enters the central nervous system by crossing the brain barrier systems: the Blood- Brain Barrier separating blood and brain and the Blood-Cerebrospinal Fluid Barrier (BCSFB) between blood and CSF, which is in contact with the brain by far less selective barriers. Herein, we develop a two-compartmental model for the BCSFB, based on first-order ordinary differential equations, performing numerical simulations and sensitivity analysis. Furthermore, as input parameters of the model, experimental data from patients affected by Alzheimer's disease, frontotemporal dementia, mild cognitive impairment and matched neurological controls were used, with the aim of investigating the differences between physiological and pathological conditions in the regulation of iron passage between blood and CSF which can be possibly targeted by therapy.

Incorporation of Cró thermal water in a dermocosmetic formulation: cytotoxicity effects, characterization and stability studies and efficacy evaluation

OBJECTIVE

Development of cosmetic formulations to provide a controlled release of hydrophilic active compounds from mineral medicinal waters constitutes an attractive challenge. The objective of this study was the development and the characterization of a dermocosmetic gel formulation with Cró thermal water, from Beira Interior of Portugal, as a major functional ingredient.

METHODS

Concentrations of mineral chemical elements of Cró thermal water were previously determined by inductively coupled plasma-optical emission spectrometry or mass spectrometry and cytotoxicity assays using thermal water were carried out on normal human dermal fibroblasts (NHDF) cells. Then, the Cró thermal water was included (more than 90%) in a developed gel formulation that was characterized through rheological and texture analysis and submitted to stability assays during 30 days. The effects on the skin volunteers, namely skin pH, the degree of hydration, transepidermal water loss and skin relief, were evaluated through non-invasive biometric techniques. A gel formulation including purified water was used as a control.

RESULTS

Cró thermal water is rich on several chemical elements in particular sodium, silica, potassium and calcium besides some trace elements, with important functions for the skin. NHDF cells adhered and proliferated in the presence of thermal water confirming the biocompatibility of the major component of the gel formulation. The developed gel formulation based on thermal water resulted in an improvement of textural parameters, comparing with the purified water-based one. Significant improvements in the cutaneous biometric parameters (degree of hydration, transepidermal water loss and skin relief) of volunteers were also registered for the gel formulation containing thermal water.

CONCLUSION

This study demonstrated for the first time the potential benefits of Cró thermal water in a gel formulation to be used in cosmetic and dermatological applications.

Dynamics of inorganic components in lake waters from Terra Nova Bay, Antarctica

Water and Suspended Particulate Material (SPM) samples analysed in this work were collected in the austral summer 2011/12 from six shallow Antarctic lakes (Carezza, Edmonson Point 14 and 15a, Gondwana, Inexpressible Island 10b and Tarn Flat 20) of Terra Nova Bay (Northern Victoria Land, Antarctica). The total concentrations of a large suite of inorganic analytes were determined, in order to gain insight into the natural processes regulating species distribution, define natural background values and detect possible present or future local and/or global anthropogenic contamination. Lake water composition was found to be influenced by marine spray, lake geographical position and meltwater input. Seasonal variability was also evaluated for each analyte, and explained considering the natural transport processes involving each species. Multivariate chemometric techniques were used in order to identify groups of samples with similar characteristics and find out similarities and correlations among variables. The variability observed within the water samples is closely connected to the marine aerosol input; hence, it is primarily a consequence of geographical and meteorological factors, such as distance from the ocean and period of year. Higher element concentrations have been found in SPM than in water, suggesting that weathering plays an important role on the chemistry of these lakes or that adsorption processes take place. SPM samples were also examined with a Scanning Electron Microscope (SEM), and many diatoms belonging to different species were detected. No clear evidence of a relevant metal contamination was found in the investigated area.

An approach for arsenic in a contaminated soil: speciation, fractionation, extraction and effluent decontamination

The fractionation and speciation of As in a contaminated soil were investigated, and a remediation strategy was tested. Regarding speciation, we found that As(V) prevails over As(III) whereas more than 40% of total arsenic is in organic form. The fractionation of As was investigated with two sequential extraction methods: a low mobility was found. Then we tested the possibility of using phosphoric acid to extract As from the soil and cleaning the washing effluents by sorption onto montmorillonite. The efficiency of the extraction and of the adsorption onto the clay were also investigated for Cr, Cu, Fe, Mn, Ni, Pb and Zn, whose total concentrations and fractionation in the soil are reported here. The extraction percentages for As and metals ranged from 30 to 65%; the residual proportions in the soil are presumably in very unreactive forms. Montmorillonite showed a good uptake capacity towards the investigated pollutants.

Adsorption of heavy metals on vermiculite: Influence of pH and organic ligands

The sorption behaviour of vermiculite has been studied with respect to cadmium, copper, lead, manganese, nickel, and zinc as a function of pH and in the presence of different ligands. The continuous column method was used in order to evaluate the feasibility to use the clay in wastewater purification systems. The total capacity of vermiculite was found to decrease in the following order: Mn > Ni > Zn > Cd > Cu > Pb. The adsorption of metal ions on vermiculite decreases with decreasing pH and increasing ionic strength. In general, the metal uptake on the clay was hindered by the presence of strong complexing agents in solution and it decreases with increasing of the complexation constants of the ligands with exception of cysteine and tiron. It is necessary, hence, to consider all these factors to effectively predict the uptake efficiency of this sorbent. However, it is possible to conclude that the vermiculite has good potentialities for cost-effective treatments of metal-contaminated wastewaters.

Adsorption of heavy metals on Na-montmorillonite. Effect of pH and organic substances

Clays (especially montmorillonite and bentonite) are widely used as barriers in landfills to prevent contamination of subsoil and groundwater by leachates containing heavy metals. For this reason it is important to study the adsorption of metals by these clays. The sorption of seven metals (Cd, Cr, Cu, Mn, Ni, Pb and Zn) on Na-montmorillonite was studied as a function of pH and in the presence of ligands, forming complexes of different stabilities with the metals of interest. The continuous column method was used as it better simulates natural conditions. The total capacity of Na-montmorillonite towards these metals was determined. The pH variations influence to a higher extent the concentrations of Cu, Pb and Cd in the effluent. Moreover the results suggest that complex formation hinders the sorption of the metals on the clay, with an increasing influence in the order: Mn < or = Pb < or = Cd < or = Zn < Ni < Cu < Cr. The evaluation of the total capacity of Na-montmorillonite shows that this clay is a good sorbent towards all examined metals.

Heavy metals in agricultural soils from Piedmont, Italy. Distribution, speciation and chemometric data treatment

The distribution and speciation of heavy metals in five agricultural soils of Piedmont Region (north-western Italy) were investigated. Ten metals, namely Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Ti and Zn were considered. Analytical determinations were performed by atomic emission or atomic absorption spectroscopy after microwave sample dissolution in acid solution. Total metal concentrations fit in the typical concentration ranges for unpolluted soils, with the exception of cadmium and lead content in some horizons. The effect of sampling depth on concentrations was discussed. Speciation studies were carried out by applying Tessier's procedure, which allows to subdivide the total metal content into five fractions, representing portions bound to different components of the soil. Moreover, the element labilities in two soils were evaluated by extraction with EDTA. Correlations among the variables and/or similarities among the sampling points were identified by principal component analysis and hierarchical cluster analysis.